Viral helicase inhibitors that bind to a novel allosteric binding site

Abstract

The present application provides small molecule compounds that inhibit viral helicases, particularly coronavirus Nsp13 helicase, and the use of such compounds to prevent and treat viral infections, particularly coronavirus viral infections.

Description

[Technical field]

[0001] The present application provides small molecule compounds that inhibit viral helicases, particularly the Nsp13 helicase of coronaviruses, and the use of such compounds to prevent and treat viral infections, particularly to treat coronavirus viral infections. [Background technology]

[0002] 2. Background of the Invention The viral pandemic caused by severe respiratory syndrome coronavirus 2 (SARS-CoV-2) is one of the worst respiratory disease outbreaks in the past 100 years, with more than 4.5 million deaths in the year since the first viral infection occurred in Wuhan Province, China in December 2019. The pandemic has had a global socio-economic impact, affecting the lives of billions of people around the world. However, to date, there are no effective therapies approved for the treatment of COVID-19, the disease caused by SARS-CoV-2 infection. To date, the most promising therapies are repurposing approaches of known antiviral drugs, such as remdesivir (HIV), indinavir (HIV), saquinavir (HIV), and lopinavir / ritonavir (HIV, Hepatitis C), that target proteases and polymerases essential for viral replication. However, to date, there are no approved targeted therapies for COVID-19, and current treatments are focused only on alleviating symptoms, which may include fever, dry cough, and pneumonia. Thus, there is a high medical need for targeted treatment of human coronavirus infections, especially in light of current reports showing declining antibody titers in patients after COVID-19 infection, calling into question the efficacy of vaccines (Long, Q, et al. (2020) Nat. Med., https: / / doi.org / 10.1038 / s41591-020-0965-6).

[0003] Coronaviruses are single-stranded, positive-sense RNA viruses, and seven types have been identified in humans: 229E, NL63, OC43, HKU1, MERS-CoV, SARS-CoV, and SARS-CoV-2. Symptoms of infection range from mild respiratory distress to more severe illness that can be fatal. The 29.9 kb SARS-CoV-2 genome contains at least six open reading frames (ORFs), of which the first ORF (ORF1a / b) accounts for more than 70% of the genome. This ORF encodes 16 nonstructural proteins (nsp1-16) that have been shown to play major roles in viral replication. Four major structural proteins, including spike, envelope, membrane, and nucleocapsid, are encoded by ORFs near the 3' end of the genome. These proteins are important for virion assembly and cell entry, ultimately resulting in coronavirus cellular infection. In addition, specific structural and accessory proteins such as HE proteins are also encoded by the coronavirus genome (Chen, Y. et al. (2020) J. Med. Virol., 92:418-423). Interestingly, SARS-CoV-2 shares over 80% identity at the nucleotide level with the first identified SARS epidemic virus, which was less infectious but more lethal (LE Gralinski, VD Menachery (2020) Viruses, 12: 135).

[0004] Surprisingly, while coronavirus structural proteins show a large variability between different coronavirus species, the major nonstructural proteins (NSPs), especially the helicase Nsp13, have been shown to be more conserved. In particular, SARS-CoV and SARS-CoV-2 coronavirus family viral helicases show more than 99% sequence identity (see Figure 1). Quite remarkably, there is a close evolutionary relationship between viral helicases, especially those of the coronavirus family (see Figure 2). The amino acid sequence that constitutes the allosteric pocket is highly conserved among the class Pisoniviridae, especially the order Nidovirales, more specifically the suborder Cornidovirales, and most specifically the family Coronaviridae, showing at least 57% sequence identity and more than 28% similarity among the coronavirus family (see Figure 3). The structures of MERS-CoV, SARS-CoV and SARS-CoV2 Nsp13 helicases have been elucidated by X-ray crystallography (Hao, W. et al. (2017) PLos Pathog, 13: e1006474-e1006474 and Jia, Z. et al. (2019) Nucleic Acids Res 47: 6538-6550) (Figure 4), with overall RMSD values ​​ranging from 1.15 to 1.6 Å. 2 The protein shows high structural similarity to the SF1 superfamily of helicases, ranging from 0.1 to 1.0. This protein belongs to the SF1 superfamily of helicases and consists of five domains: an N-terminal zinc-binding domain (ZBD), a helical stalk domain, a 1B domain, and two RecA-like domains 1A and 2A that contain six conserved active site motifs. It is therefore particularly preferred to treat infections with viruses that contain helicases belonging to the SF1 superfamily with the compounds of the invention.

[0005] Viral helicases are motor proteins that catalyze the unwinding of double-stranded RNA or DNA oligonucleotides in the 5' to 3' direction into single strands using energy derived from ATP hydrolysis. This enzymatic activity is essential for the replication of the viral genome and has been shown to be required for the transcription and translation of viral mRNA, the breakdown of the RNA-protein complex, and the packaging of nucleic acids into virions. Importantly, the herpes simplex helicase has been shown to be a useful target for antiviral drugs to inhibit viral replication in animal models (Crute, JJ, et al. (2002) Nat Med., 8:386-391 and Kleymann G, et al. (2002) Nat Med. 2002;8:392-398).

[0006] However, the development of non-toxic helicase inhibitors has historically been considered much more challenging because the ATP-binding site of helicases is conserved not only in different classes of helicases but also in motor proteins, small GTPases, kinases, and AAA+ family ATPases (Fig 1A in DN Frick and AMI Lam (2006) Curr. Pharm. Des., 12(11): 1315-1338). Therefore, compounds that inhibit helicases by an ATP-competitive mechanism have generally been considered to have potential toxicities. Another inherent problem with ATP-competitive inhibitors of helicases is the high ATP concentration in target cells, typically maintained at 1–10 mmol / L. Effective inhibition by ATP-competitive inhibitors requires either achieving high intracellular concentrations of the inhibitor or a K that is several orders of magnitude lower than the binding of ATP to the NTPase active site. DThis requires the identification of competitive inhibitors that bind either at or covalently to the NTPase active site. Mirza MU & Froeyen M. (J. Pharm. Anal. (2020) 10(4):320-328) have solved the structures of three SARS-CoV-2 proteins, namely the main protease, Nsp12 polymerase and Nsp13 helicase, by computational methods. They have used in silico methods to identify possible binding modes and structurally important binding site residues located in the ATP binding site, and have identified potential drug candidates that bind to the ATP binding site. For Nsp13 helicase, they have identified several small molecules that can inhibit NTPase by interfering with ATP binding in the active site, i.e., Mirza et al. (supra) have identified competitive inhibitors of the ATP binding site of Nsp13 helicase.

[0007] Ugurel and coworkers (OM Ugurel et al. Int. J. Biol. Macromol. (2020) 163:1687-1696) use in silico methods to evaluate the efficacy of FDA-approved drugs against wild-type and mutant SARS-CoV-2 helicase (Nsp13). They note that the most potent drugs were found to interact with critical and neighboring residues in the active site responsible for ATP hydrolysis. However, Ugurel et al. (supra) did not actually test the activity of any of the compounds for their ability to inhibit Nsp13 helicase. Thus, Ugurel et al. identify potential competitive inhibitors of ATP binding to Nsp13 helicase by in silico modeling.

[0008] Gurung AB (Gene Reports (2020) 21:100860) has also performed in silico structural modeling of SARS-CoV-2 Nsp13 helicase and Nsp14, and has further performed virtual screening (i.e., also in silico) of FDA-approved antiviral drugs. For this purpose, the NTPase binding pocket (i.e., active site) of Nsp13 helicase was used for docking of antiviral drugs. However, Gurung did not actually test the activity of any compound for its ability to inhibit Nsp13 helicase. Thus, Ugurel et al. have identified potential competitive inhibitors of ATP binding to Nsp13 helicase by in silico modeling. Thus, the art is focused on the development of a novel inhibitor that is more specific to the helicase and inhibits K rather than competitive inhibition of ATP binding. D There is a need to identify novel inhibitors of viral helicases, particularly Nsp13 helicase, that are less demanding in terms of their ability to bind to the ATP binding site itself. The present invention solves these and other problems by providing compounds that inhibit the enzymatic activity of viral helicases by binding to an allosteric control site of the viral helicase, rather than the ATP binding site itself. The present invention relates to compounds that inhibit the enzymatic activity of viral helicases, particularly those of viruses of the class Pisoniviridae, more preferably those of viruses of the order Nidovirales, even more preferably those of viruses of the suborder Cornidoviridae, and most preferably those of the family Coronaviridae. Within the family Coronaviridae, the nonstructural protein 13 (Nsp13) helicase of SARS-CoV-2 is a particularly preferred target. The compounds of the present invention target a novel allosteric binding pocket of viral helicases, preferably the Nsp13 helicase of SARS-CoV-2. This pocket was identified using molecular dynamics followed by small molecule docking. The present invention further relates to such compounds for use in the prevention and treatment of viral infections, in particular infections of the class Pisoniviridae, more preferably the order Nidovirales, even more preferably the suborder Cornidoviridae, most preferably the family Coronaviridae.Accordingly, the present invention relates to the prevention and treatment of infections by all virus species which contain a homologous helicase. Summary of the Invention [Problem to be solved by the invention]

[0009] The compounds of the present invention offer the following advantages over the prior art in particular: (i) they target structural proteins that are not only highly conserved among the Coronaviridae family (more than 99% amino acid sequence identity within this virus family) but also among viruses belonging to the Pisoniviridae class, and therefore it is expected that infections with novel coronaviruses that are the result of mutations of existing coronaviruses pathogenic to humans or that change from an animal host to humans can also be prevented and / or treated with the compounds of the present invention, (ii) they target the allosteric binding pocket of the viral helicase, so off-target effects are expected to be much lower than compounds that may function via an ATP competitive mechanism, and / or (iii) the compounds are effective even as low affinity binders. Thus, the compounds of the present invention that target these sites act very specifically against viruses that contain helicases belonging to the SF1 superfamily. [Means for solving the problem]

[0010] Summary of the Invention In a first aspect, the present invention is directed to inhibitors of the helicase activity of the Nsp13 helicase of SARS-CoV-2 or its viral homologues, wherein the inhibitors specifically bind to an allosteric binding pocket within the N-terminal lobe of the ATPase domain of Nsp13 or its viral homologues.

[0011] In a second aspect, the present invention is directed to an inhibitor of the helicase activity of Nsp13 helicase according to formulas (I) to (IV).

[0012] In a third aspect, the present invention is directed to a pharmaceutical composition comprising an inhibitor according to the first or second aspect of the invention.

[0013] In a fourth aspect, the present invention is directed to an inhibitor according to the first or second aspect of the invention or a pharmaceutical composition according to the third aspect of the invention for use in therapy.

[0014] In a fifth aspect, the present invention is directed to an inhibitor according to the first or second aspect of the invention or a pharmaceutical composition according to the third aspect of the invention for use in the prevention or treatment of a viral infection.

[0015] In a preferred embodiment of the fifth aspect of the invention, the viral infection is an infection with positive-sense single-stranded (ss) RNA. [Brief description of the drawings]

[0016] [Figure 1] Sequence divergence between the nonstructural proteins of SARS-CoV and SARS-CoV-2 is shown (Fig. 1 in Frick, DN et al (2020) Biochemistry, 59:2608-2615). The viral helicase is the most conserved protein among the NSPs, with over 99% sequence identity at the amino acid level.

[0017] [Diagram 2] Panel (A) shows the evolutionary relationship of the viral helicase to other viral and cellular helicases (adapted from Frick & Lam (2006) supra). Panel (B) shows the phylogenetic tree of the seven known human CoV helicases (B).

[0018] [Diagram 3]Alignment of the helicases that form the allosteric binding pockets of seven coronaviruses, namely, Nsp13 helicase of HCoV-229E, referred to in the diagram as "229E" (SEQ ID NO: 2), Nsp13 helicase of HCoV-NL63, referred to in the diagram as "NL-63" (SEQ ID NO: 3), Nsp13 helicase of HCoV OC43, referred to in the diagram as "OC43" (SEQ ID NO: 4), Nsp13 helicase of CoV HKU1, referred to in the diagram as "HKU1H" (SEQ ID NO: 5), Nsp13 helicase of MERS CoV (SEQ ID NO: 6), Nsp13 helicase of SARS CoV (SEQ ID NO: 7) and Nsp13 helicase of SARS CoV2 (SEQ ID NO: 1), is shown. The allosteric binding pockets of the seven coronavirus helicases are highlighted by boxes. In SARS CoV2, the allosteric binding pocket spans S236-T440. Of these 205 amino acids, only 28 form the binding pocket. These amino acids are highlighted in bold in SARS-CoV2 and also in the other six coronavirus helicases. Of the 28 amino acids that form the binding pocket, 57.1% of the amino acid residues are identical, 17.9% are highly similar, 10.7% are similar, and 14.3% are different. Thus, within the regions relevant for the interaction of the compounds of the present invention, the seven coronavirus helicases share 85.7% homology. Furthermore, the alignment results in the identification of several conserved motifs in coronavirus helicases, which are highlighted by underlines in all seven amino acid sequences. Furthermore, the amino acids highlighted in light gray are absolutely conserved in the active site motif.

[0019] [Figure 4]Panel (A) shows a cartoon representation of the structure of SARS-CoV2 Nsp13 (taken from PDB 6XEZ, Chen et al., 2020, Cell 182, 1-14). The N-terminal zinc-binding domain (ZBD) with three bound zinc ions (dark spheres), the stalk domain, the 1B domain, and the two RecA-like domains 1A and 2A are labeled, respectively. The nucleotide-binding cleft with the bound transition-state analog ADP-AF3 is indicated by an arrow. Panel (B) highlights RecA lobes 1A and 2A and shows conserved residues of the six active site motifs as sticks. The transition-state analog ADP-AF3 (grey) and the coenzyme Mg2+ (black) are shown as spheres. The location of the newly identified allosteric pocket is shown in a surface representation and does not overlap with the nucleotide-binding site.

[0020] [Diagram 5] Panel (A) shows a top view of the sliced ​​surface of the SARS-CoV2 helicase domain N-terminal lobe S236-T440 (lobe 1), with the tripartite pocket consisting of the entry channel (1), left channel (2) and right channel (3) and the active site (4) circled. Panel (B) shows a bottom view of the sliced ​​surface of the SARS-CoV2 helicase domain N-terminal lobe S236-T440 (lobe 1), with the tripartite pocket consisting of the entry channel (1), left channel (2) and right channel (3) and the active site (4) circled.

[0021] [Figure 6] A) Top view of the sliced ​​surface of SARS-CoV-2 helicase domain lobe 1A colored for hydrophobicity with hydrophilic regions shown in white and hydrophobic regions shown in black. B) Bottom view of the sliced ​​surface of SARS-CoV-2 helicase domain lobe 1A colored for hydrophobicity with hydrophilic regions shown in white and hydrophobic regions shown in black.

[0022] [Figure 7]A) Top view of a sliced ​​surface of SARS-CoV-2 helicase domain lobe 1A with compound COVI-3 approaching the entry channel and right channel (). B) Bottom view of a sliced ​​surface of SARS-CoV-2 helicase domain lobe 1A with compound COVID inhibitor (COVI) 3 (COVI-3) approaching the entry channel and right channel. C) Top view of a sliced ​​surface of SARS-CoV2 helicase domain lobe 1 with compound COVI-10 approaching the entry channel, right channel and left channel. D) Bottom view of a sliced ​​surface of SARS-CoV2 helicase domain lobe 1A with compound COVI-10 approaching the entry channel, right channel and left channel. E) Top view of a sliced ​​surface of SARS-CoV2 helicase domain lobe 1 with compound COVI-35 approaching the entry channel and right channel. F) Surface bottom view of sliced ​​SARS-CoV2 helicase domain lobe 1A with compound COVI-35 approaching the entry channel and right channel ().

[0023] [Figure 8] Panel (A) shows the molecular surface of compound COVI-10 from three different angles. Region 1 contains polar substituents, while regions 2 and 3 are mostly non-polar. Panel (B) shows the molecular surface of compound COVI-3 from three different angles. Region 1 contains polar substituents, while regions 2 and 3 are mostly non-polar. (C) shows the molecular surface of compound COVI-35 from three different angles. Region 1 contains polar substituents, while region 2 is non-polar.

[0024] [Figure 9]Panel (A) is a top view of the surface of compound COVI-10 surrounded by residues that make up the binding pocket of SARS-CoV2 helicase domain lobe 1A. Panel (B) is a bottom view of the surface of compound COVI-10 surrounded by residues that make up the binding pocket of SARS-CoV-2 helicase domain lobe 1. Panel (C) is a top view of the surface of compound COVI-3 surrounded by residues that make up the binding pocket of SARS-CoV2 helicase domain lobe 1. Panel (D) is a bottom view of the surface of compound COVI-3 surrounded by residues that make up the binding pocket of SARS-CoV2 helicase domain lobe 1. Panel (E) is a top view of the surface of compound COVI-35 surrounded by residues that make up the binding pocket of SARS-CoV2 helicase domain lobe 1. Panel (F) is a bottom view of the surface of compound COVI-35 surrounded by residues that make up the binding pocket of SARS-CoV2 helicase domain lobe 1.

[0025] [Figure 10] Panel (A) shows the bottom view of compound COVI-10, which shows specific interactions with N158, F143 and I169. B) The bottom view of compound COVI-3, which shows specific interactions with N158. C) The top view of compound COVI-35, which shows specific interactions with M429.

[0026] [Figure 11] Panel (A) is a rig plot of compound COVI-10 at the allosteric binding site of SARS-CoV2 Nsp13 lobe 1. Panel (B) is a rig plot of compound COVI-3 at the allosteric binding site of SARS-CoV2 Nsp13 lobe 1. Panel (C) is a rig plot of compound COVI-35 at the allosteric binding site of SARS-CoV2 Nsp13 lobe 1.

[0027] [Figure 12] Dose-response curves of active SARS-CoV-2 Nsp13 inhibitors tested in a FRET-based DNA unwinding helicase assay.

[0028] [Figure 13] Figure 1 shows dose-response curves of selected SARS-CoV2 Nsp13 inhibitors tested in a malachite green-based ATPase assay.

[0029] [Figure 14] Table showing the structures of COVI inhibitors and their respective IC50s determined in DNA unwinding and ATPase assays.

[0030] [Figure 15] 1 shows dose-response curves for selected Nsp13 inhibitors tested in a cell infection assay with 229E coronavirus.

[0031] [Figure 16] Shows dose-response curves of selected SARS-CoV2 Nsp13 inhibitors tested in the SARS-CoV-2 nanoluciferase assay.

[0032] [Figure 17] General synthetic scheme for compounds of formula (I) containing a pyrazole core structure. The three substituents which are then covalently attached to the core are shown without substituents, but as is commonly known in the art, may contain such substituents upon attachment and / or may contain protecting groups which protect such substituents during the coupling reaction and are subsequently removed or which can be subsequently cleaved to create a new reactive group to which the desired substituent is ultimately attached.

[0033] [Figure 18]A general synthetic scheme for compounds of formula (II) consisting of a quinazoline core structure, in which the two substituents which are then covalently attached to the core are shown without substituents, but may contain such substituents when attached as is generally known in the art and / or may contain protecting groups which protect such substituents during the coupling reaction and are subsequently removed or which can be subsequently cleaved to create a new reactive group to which the desired substituent is ultimately attached.

[0034] [Figure 19] General synthesis scheme for compounds of formula (III)

[0035] [Figure 20] A list of suppliers from which each compound was obtained.

[0036] [Figure 21] Panel (A) shows a sliced ​​surface of the SARS-CoV-2 Nsp13 helicase domain lobe 1A with compound COVI-3 approaching the entry channel and right channel. The inhibitor binding sites reported by Mirza and Froeyen (supra) and Gurung (supra) are circled, and residues shared between the binding sites (D144, E145, and M148) are colored black. Panel (B) shows a ribbon representation of the SARS-CoV-2 Nsp13 helicase domain lobe 1A with amino acids that directly interact with the compounds reported by Mirza and Froeyen and Gurung in black, binding site residues that directly interact with the compounds reported here in light grey, and shared in white. It is clear that the inhibitors reported by Mirza and Froeyen (supra) and Gurung (supra) bind to different pockets of NSP13 and, therefore, the prior art inhibitors are different from the compounds of the present invention which bind to the allosteric binding pocket of the viral helicase. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0037] Detailed Description of the Invention Before the present invention is described in detail below, it should be understood that the present invention is not limited to the specific methodology, protocols, and reagents described herein, as they may vary. It should also be understood that the terms used herein are for the purpose of describing specific embodiments only, and are not intended to limit the scope of the present invention, which is limited only by the appended claims. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art.

[0038] Several documents are cited in the text of this specification. Each document cited herein (including all patents, patent applications, scientific publications, manufacturer's specifications, instructions, etc.), whether supra or infra, is hereby incorporated by reference in its entirety. Nothing herein should be construed as an admission that the invention is not entitled to antedate such disclosure by virtue of prior invention.

[0039] In order to practice the present invention, unless otherwise indicated, conventional methods of chemistry, biochemistry and recombinant DNA technology are employed, which are explained in the art (see, e.g., Molecular Cloning: A Laboratory Manual, 2nd Edition, edited by J. Sambrook et al., Cold Spring Harbor Laboratory Press, Cold Spring Harbor 1989).

[0040] definition Throughout this specification and the claims that follow, unless the context dictates otherwise, the word "comprises" and variations such as "comprises" and "including" are understood to mean the inclusion of a stated integer or step or group of integers or steps, but not the exclusion of other integers or steps or groups of integers or steps. As used in this specification and the appended claims, the singular forms "a," "an," and "the" include plural references unless the content clearly dictates otherwise.

[0041] In the following paragraphs, the definitions of the terms alkyl, heteroalkyl, haloalkyl, cycloalkyl, heterocycloalkyl, aryl, aralkyl, heteroaryl, heteroaralkyl, alkenyl, cycloalkenyl, heteroalkenyl, heterocycloalkenyl and alkynyl are provided. These terms have their respective defined and preferred meanings in each instance of use in the remainder of this specification. Nevertheless, in some instances of use throughout this specification, preferred meanings of these terms are indicated.

[0042] The term "alkyl" refers to a saturated straight or branched carbon chain. Preferably, the chain contains 1 to 10, i.e., 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 carbon atoms, such as methyl, ethylpropyl (n-propyl or iso-propyl), butyl (n-butyl, iso-butyl, sec-butyl, tert-butyl), pentyl, hexyl, heptyl, octyl, nonyl, decyl. Alkyl groups are optionally substituted.

[0043] The term "heteroalkyl" refers to a saturated straight or branched carbon chain. Preferably, the chain contains 1 to 9, i.e. 1, 2, 3, 4, 5, 6, 7, 8 or 9 carbon atoms, interrupted one or more times, e.g. 1, 2, 3, 4, 5, 6, 7, 8 or 9, with the same or different heteroatoms, e.g. methyl, ethyl, propyl, iso-propyl, butyl, iso-butyl, sec-butyl, tert-butyl, pentyl, hexyl, heptyl, octyl, nonyl. Preferably, the heteroatoms are selected from O, S and N, e.g. -(CH2) n -X-(CH2) m CH3, n=0, 1, 2, 3, 4, 5, 6, 7, 8 or 9, m=0, 1, 2, 3, 4, 5, 6, 7, 8 or 9, and X=S, O or NR', with R'=H or a hydrocarbon (e.g., C1-C6 alkyl). In particular, "heteroalkyl" includes -O-CH3, -OC2H5, -CH2-O-CH3, -CH2-O-C2H5, -CH2-O-C3H7, -CH2-O-C4H9, -CH2-O-C5H 11 , -C2H4-O-CH3, -C2H4-O-C2H5, -C2H4-O-C3H7, -C2H4-O-C4H9, etc. Heteroalkyl groups are optionally substituted.

[0044] The term "haloalkyl" refers to a saturated straight or branched carbon chain in which one or more hydrogen atoms have been replaced with a halogen atom, such as fluorine, chlorine, bromine or iodine. Preferably, the chain contains 1 to 10 carbon atoms, i.e., 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 carbon atoms. In particular, "haloalkyl" refers to -CH2F, -CHF2, -CF3, -C2H4F, -C2H3F2, C2H2F3, -C2HF4, -C2F5, -C3H6F, -C3H5F2, -C3H4F3, -C3H3F4, -C3H2F5, -C3HF6, -C3F7, -CH2Cl, -CHCl2, -CCl3, -C2H4Cl, -C2H3Cl2, -C2H2Cl3, -C2HCl4, -C2Cl5, -C3H6Cl, -C3H5Cl2, -C3H4Cl3, -C3H3Cl4, -C3H2Cl5, -C3HCl6, and -C3Cl7. Haloalkyl groups are optionally substituted.

[0045] The terms "cycloalkyl" and "heterocycloalkyl", alone or in combination with other terms, represent, unless otherwise specified, cyclic versions of "alkyl" and "heteroalkyl", respectively, preferably having 3, 4, 5, 6, 7, 8, 9 or 10 atoms forming the ring, such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, etc. The terms "cycloalkyl" and "heterocycloalkyl" are also meant to include bicyclic, tricyclic and polycyclic versions thereof. When a bicyclic, tricyclic or polycyclic ring is formed, it is preferred that the respective rings are linked to each other at two adjacent carbon atoms, although alternatively, two rings are linked through the same carbon atom, i.e., forming a spiro ring system or forming a "bridged" ring system, preferably tricyclo[3.3.1.13,7]decane. The term "heterocycloalkyl" preferably refers to a saturated ring having 5 members, at least one of which is an N, O or S atom, and optionally containing one additional O or one additional N; a saturated ring having 6 members, at least one of which is an N, O or S atom, and optionally containing one additional O or one additional N or two additional N atoms; or a saturated bicyclic ring having 9 or 10 members, at least one of which is an N, O or S atom, and optionally containing one, two or three additional N atoms. "Cycloalkyl" and "heterocycloalkyl" groups are optionally substituted. Furthermore, in the case of heterocycloalkyl, a heteroatom can occupy the position at which the heterocycle is attached to the remainder of the molecule. Examples of cycloalkyl include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, spiro[3,3]heptyl, spiro[3,4]octyl, spiro[4,3]octyl, spiro[3,5]nonyl, spiro[5,3]nonyl, spiro[3,6]decyl, spiro[6,3]decyl, spiro[4,5]decyl, spiro[5,4]decyl, bicyclo[2.2.1]heptyl, bicyclo[2.2.2]octyl, adamantyl, and the like.Examples of heterocycloalkyl include 1-(1,2,5,6-tetrahydropyridyl), 1-piperidinyl, 2-piperidinyl, 3-piperidinyl, 4-morpholinyl, 3-morpholinyl, 1,8-diazo-spiro[4,5]decyl, 1,7-diazo-spiro[4,5]decyl, 1,6-diazo-spiro[4,5]decyl, 2,8-diazo-spiro[4,5]decyl, 2,7-diazo-spiro[4,5]decyl, 2,6-diazo-spiro[4,5]decyl, 1,8-diazo-spiro[5, 4] decyl, 1,7-diazo-spiro[5,4] decyl, 2,8-diazo-spiro[5,4] decyl, 2,7-diazo-spiro[5,4] decyl, 3,8-diazo-spiro[5,4] decyl, 3,7-diazo-spiro[5,4] decyl, 1,4-diazabicyclo[2.2.2]oct-2-yl, tetrahydrofuran-2-yl, tetrahydrofuran-3-yl, tetrahydrothien-2-yl, tetrahydrothien-3-yl, 1-piperazinyl, 2-piperazinyl, and the like.

[0046] The term "aryl" preferably refers to an aromatic monocyclic ring containing 6 carbon atoms, an aromatic bicyclic ring system containing 10 carbon atoms, or an aromatic tricyclic ring system containing 14 carbon atoms. For example, phenyl, naphthyl, or anthracenyl. The aryl group is optionally substituted.

[0047] The term "aralkyl" refers to an alkyl moiety substituted with an aryl, where alkyl and aryl have the meanings outlined above. Examples include the benzyl radical. Preferably, in this context, the alkyl chain contains 1 to 8, i.e. 1, 2, 3, 4, 5, 6, 7 or 8 carbon atoms, such as methyl, ethyl, propyl, iso-propyl, butyl, iso-butyl, sec-butyl, tert-butyl, pentyl, hexyl, heptyl, octyl. The aralkyl group is optionally substituted in the alkyl and / or aryl parts of the group. Preferably, the aryl bonded to the alkyl means phenyl, naphthyl or anthracenyl.

[0048] The term "heteroaryl" preferably refers to a 5- or 6-membered aromatic monocyclic ring in which at least one of the carbon atoms is replaced by 1, 2, 3 or 4 (in the case of a 5-membered ring) or 1, 2, 3, 4 or 5 (in the case of a 6-membered ring) identical or different heteroatoms, preferably selected from O, N and S; an 8- to 12-membered aromatic bicyclic ring system in which 1, 2, 3, 4, 5 or 6 carbon atoms of the 8-, 9-, 10-, 11- or 12-membered carbon atoms are replaced by identical or different heteroatoms, preferably selected from O, N and S; or a 13- to 16-membered aromatic tricyclic ring system in which 1, 2, 3, 4, 5 or 6 carbon atoms of the 13-, 14-, 15- or 16-membered carbon atoms are replaced by identical or different heteroatoms, preferably selected from O, N and S. For example, furanyl, thiophenyl, oxazolyl, isoxazolyl, 1,2,4-oxadiazolyl, 1,2,3-oxadiazolyl, pyrrolyl, imidazolyl, pyrazolyl, 1,2,3-triazolyl, 1,2,4-triazolyl, thiazolyl, isothiazolyl, 1,2,3-thiadiazolyl, 1,2,4-thiadiazolyl, pyridinyl, pyrimidinyl, pyrazinyl, 1,2,3-triazinyl, 1,2,4-triazinyl, 1,3,5-triazinyl, 1-benzofuranyl, 2-benzofuranyl, Heteroaryl groups are optionally substituted.

[0049] The term "heteroaralkyl" refers to an alkyl moiety substituted by a heteroaryl, where alkyl and heteroaryl have the meanings as outlined above. Examples include 2-alkylpyridinyl, 3-alkylpyridinyl or 2-methylpyridinyl radicals. Preferably, in this context, the alkyl chain contains 1 to 8, i.e. 1, 2, 3, 4, 5, 6, 7 or 8 carbon atoms, such as methyl, ethyl, propyl, iso-propyl, butyl, iso-butyl, sec-butyl, tert-butyl, pentyl, hexyl, heptyl, octyl. Heteroaralkyl groups are optionally substituted in the alkyl and / or heteroaryl portions of the group. Preferably, the heteroaryl attached to the alkyl is oxazolyl, isoxazolyl, 1,2,5-oxadiazolyl, 1,2,3-oxadiazolyl, pyrrolyl, imidazolyl, pyrazolyl, 1,2,3-triazolyl, 1,2,4-triazolyl, thiazolyl, isothiazolyl, 1,2,3-thiadiazolyl, 1,2,5-thiadiazolyl, pyridinyl, pyrimidinyl, pyrazinyl, 1,2,3-triazinyl, 1,2,4-triazinyl, 1,3,5-triazinyl, 1-benzofuranyl, 2 ... Heteroaralkyl groups may be optionally substituted in the alkyl and / or heteroaryl portions of the group.

[0050] The terms "alkenyl" and "cycloalkenyl" refer to an olefinically unsaturated carbon atom containing chain or ring with one or more double bonds. Examples include propenyl and cyclohexenyl. Preferably, the alkenyl chain contains 2 to 8, i.e., 2, 3, 4, 5, 6, 7 or 8 carbon atoms, such as ethenyl, 1-propenyl, 2-propenyl, iso-propenyl, 1-butenyl, 2-butenyl, 3-butenyl, iso-butenyl, sec-butenyl, 1-pentenyl, 2-pentenyl, 3-pentenyl, 4-pentenyl, hexenyl, heptenyl, octenyl. Preferably, the cycloalkenyl ring contains 3 to 8, i.e., 3, 4, 5, 6, 7 or 8 carbon atoms, such as 1-cyclopropenyl, 2-cyclopropenyl, 1-cyclobutenyl, 2-cyclobutenyl, 1-cyclopentenyl, 2-cyclopentenyl, 3-cyclopentenyl, 1-cyclohexenyl, 2-cyclohexenyl, 3-cyclohexenyl, cycloheptenyl, cyclooctenyl. "Alkenyl" and "cycloalkenyl" groups may be optionally substituted.

[0051] The terms "heteroalkenyl" and "heterocycloalkenyl" refer to unsaturated versions of "heteroalkyl" and "heterocycloalkyl", respectively. Thus, the term "heteroalkenyl" refers to an unsaturated straight or branched carbon chain. Preferably, the chain contains 1 to 9, i.e. 1, 2, 3, 4, 5, 6, 7, 8, 9 carbon atoms, interrupted one or more times, e.g. 1, 2, 3, 4, 5, 6, 7, 8, 9, with identical or different heteroatoms. Preferably, the heteroatoms are selected from O, S and N. If one or more of the interrupting heteroatoms are N, N may be present as -NR'- moiety, where R' is hydrogen or a hydrocarbon (e.g. C1-C6 alkyl), or as =N- or -N= group, i.e. the nitrogen atom can form a double bond with an adjacent C atom or an adjacent further N atom. A "heteroalkenyl" group is optionally substituted. The term "heterocycloalkenyl" preferably represents a cyclic version of "heteroalkenyl" with 3, 4, 5, 6, 7, 8, 9 or 10 atoms forming the ring. The term "heterocycloalkenyl" is also meant to include its bicyclic, tricyclic and polycyclic versions. When a bicyclic, tricyclic or polycyclic ring is formed, each ring is preferably linked to each other through two adjacent atoms. These two adjacent atoms can both be carbon atoms; or one atom can be a carbon atom and the other atom a heteroatom; or the two adjacent atoms can both be heteroatoms. However, alternatively, the two rings can be linked through the same carbon atom, i.e., forming a spiro ring system or a "bridged" ring system.The term "heterocycloalkenyl" preferably refers to an unsaturated ring having 5 members, at least one of which is an N, O or S atom, and optionally containing one additional O or one additional N; an unsaturated ring having 6 members, at least one of which is an N, O or S atom, and optionally containing one additional O or one additional N or two additional N atoms; or an unsaturated bicyclic ring having 9 or 10 members, at least one of which is an N, O or S atom, and optionally containing one, two or three additional N atoms. "Heterocycloalkenyl" groups are optionally substituted. Furthermore, in the case of heteroalkenyl and heterocycloalkenyl, a heteroatom can occupy the position where the heterocycle is attached to the remainder of the molecule.

[0052] The term "aralkenyl" refers to an alkenyl moiety substituted by an aryl, where alkenyl and aryl have the meanings outlined above.

[0053] The term "heteroaralkenyl" refers to an alkenyl moiety substituted by a heteroaryl, where alkenyl and heteroaryl have the meanings outlined above.

[0054] The term "alkynyl" refers to an unsaturated carbon atom containing chain or ring with one or more triple bonds. Preferably, the alkynyl chain contains 2 to 8, i.e., 2, 3, 4, 5, 6, 7 or 8 carbon atoms, such as ethynyl, 1-propynyl, 2-propynyl, 1-butynyl, 2-butynyl, 3-butynyl, 1-pentynyl, 2-pentynyl, 3-pentynyl, 4-pentynyl, hexynyl, heptynyl, octynyl. The alkynyl group may be optionally substituted.

[0055] The terms "heteroalkynyl", "cycloalkynyl", and "heterocycloalkynyl" refer to moieties that essentially correspond to "heteroalkenyl", "cycloalkenyl", and "heterocycloalkenyl", respectively, defined above, but differ from "heteroalkenyl", "cycloalkenyl", and "heterocycloalkenyl", in that at least one double bond is replaced with a triple bond.

[0056] As used herein, the term "alicyclic" includes cycloalkyl, cycloalkenyl and cycloalkynyl substituents as defined above.

[0057] As used herein, the term "carbocycle" includes monocyclic cycloalkyl, cycloalkenyl, cycloalkynyl and aryl substituents.

[0058] As used herein, the term "heterocycle" includes monocyclic heterocycloalkyl, heterocycloalkenyl, heterocycloalkynyl and heteroaryl substituents.

[0059] In one embodiment, carbon or hydrogen atoms in the alkyl, cycloalkyl, aryl, aralkyl, alkenyl, cycloalkenyl, alkynyl radicals may be substituted, independently of one another, with one or more elements selected from the group consisting of O, S, N or groups containing one or more elements selected from the group consisting of O, S, N, i.e. 1, 2, 3, 4, 5, 6 or more elements.

[0060] Embodiments include alkoxy, cycloalkoxy, aryloxy, aralkoxy, alkenyloxy, cycloalkenyloxy, alkynyloxy, alkylthio, cycloalkylthio, arylthio, aralkylthio, alkenylthio, cycloalkenylthio, alkynylthio, alkylamino, cycloalkylamino, arylamino, aralkylamino, alkenylamino, cycloalkenylamino, alkynylamino radicals.

[0061] Other embodiments include hydroxyalkyl, hydroxycycloalkyl, hydroxyaryl, hydroxyaralkyl, hydroxyalkenyl, hydroxycycloalkenyl, hydroxyalkynyl, mercaptoalkyl, mercaptocycloalkyl, mercaptoaryl, mercaptoaralkyl, mercaptoalkenyl, mercaptocycloalkenyl, mercaptoalkynyl, aminoalkyl, aminocycloalkyl, aminoaryl, aminoaralkyl, aminoalkenyl, aminocycloalkenyl, aminoalkynyl radicals.

[0062] In another embodiment, one or more hydrogen atoms, e.g., 1, 2, 3, 4, 5, 6, 7 or 8 hydrogen atoms in the alkyl, heteroalkyl, cycloalkyl, heterocycloalkyl, alicyclic, aryl, aralkyl, heteroaryl, heteroaralkyl, alkenyl, cycloalkenyl, heteroalkenyl, heterocycloalkenyl, alkynyl radical, may be substituted, independently from one another, with one or more halogen atoms, e.g., Cl, F or Br. One preferred radical is the trifluoromethyl radical.

[0063] Where two or more radicals may be selected independently of each other, the term "independently" means that the radicals may be the same or different.

[0064] The term "optionally substituted", in each instance, unless further specified, refers to halogen (particularly F, Cl, Br or I), -NO2, -CN, -OR'', -NR'R'', -COOR'', -CONR'R'', -NR'COR'', -NR''CONR'R'', -NR'SO2E, -COR''', -SO2NR'R'', -OOCR''', -CR'''R''''OH, -R'''OH and -E; R' and R'' are each independently selected from the group consisting of hydrogen, alkyl, alkenyl, alkynyl, cycloalkyl, heterocycloalkyl, aryl, aralkyl, and heteroaryl, or together form heteroaryl, or heterocycloalkyl; R''' and R'''' are each independently selected from the group consisting of hydrogen, alkyl, alkenyl, alkynyl, cycloalkyl, heterocycloalkyl, alkoxy, aryl, aralkyl, heteroaryl, and -NR'R''; E is selected from the group consisting of alkyl, alkenyl, alkynyl, cycloalkyl, alkoxy, alkoxyalkyl, heterocycloalkyl, alicyclic, aryl, and heteroaryl, optionally substituted.

[0065] As used herein, the term "amino acid sequence identity" refers to the percentage of sequence identity, which is determined by comparing two optimally aligned sequences over a comparison window, where the portion of the sequence in the comparison window may contain additions or deletions (i.e., gaps) compared to the reference sequence (not including additions or deletions) for optimal alignment of the two sequences. The percentage is calculated by determining the number of positions where the same nucleic acid base or amino acid residue occurs in both sequences to obtain the number of matched positions, dividing the number of matched positions by the total number of positions in the comparison window, and multiplying the result by 100 to obtain the percentage of sequence identity.

[0066] The term "identical" as used herein, in the context of two or more nucleic acid or polypeptide sequences, refers to two or more sequences or subsequences that are identical, i.e., comprise the same sequence of nucleotides or amino acids. Sequences are "substantially identical" to one another if a certain percentage of nucleotides or amino acid residues are identical (e.g., at least 50%, at least 55%, at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 81%, at least 82%, at least 83%, at least 84%, at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity) when compared and aligned for maximum correspondence over a comparison window or designated region as measured using one of the following sequence comparison algorithms or by manual alignment and visual inspection. These definitions also refer to the complement of the test sequence.Therefore, the term "at least 80% sequence identity" is used throughout this specification for polypeptide and polynucleotide sequence comparison.This expression preferably refers to at least 80%, at least 81%, at least 82%, at least 83%, at least 84%, at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity with each reference polypeptide or each reference polynucleotide.

[0067] The term "sequence comparison" as used herein refers to a process in which one sequence serves as a reference sequence and a test sequence is compared to it. When using sequence comparison algorithm, test and reference sequences are input into computer, partial sequence coordinates are designated as necessary, and sequence algorithm program parameters are designated. Default program parameters are generally used, but alternative parameters can also be designated. The sequence comparison algorithm then calculates the percent sequence identity or similarity of the test sequence to the reference sequence based on the program parameters. When two sequences are compared and the reference sequence for which the percent sequence identity is to be calculated is not designated in the comparison, the sequence identity is calculated with reference to the longer of the two sequences to be compared, unless otherwise indicated. When a reference sequence is indicated, unless otherwise indicated, the sequence identity is determined based on the full length of the reference sequence indicated by SEQ ID NO.

[0068] In sequence alignment, the term "comparison window" refers to a stretch of contiguous positions of a sequence that is compared to a reference stretch of contiguous positions of a sequence having the same number of positions. The number of contiguous positions selected may range from 10 to 1000, i.e., may include 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 150, 200, 250, 300, 350, 400, 450, 500, 550, 600, 650, 700, 750, 800, 850, 900, 950 or 1000 contiguous positions. Typically, the number of contiguous positions ranges from about 20 to about 800 contiguous positions, from about 20 to about 600 contiguous positions, from about 50 to about 400 contiguous positions, from about 50 to about 200 contiguous positions, from about 100 to about 150 contiguous positions.

[0069] The method of alignment of sequences for comparison is well known in the art.The optimal alignment of sequences for comparison can be carried out, for example, by Smith and Waterman's local homology algorithm (Adv. Appl. Math. 2:482, 1970), Needleman and Wunsch's homology alignment algorithm (J. Mol. Biol. 48:443, 1970), Pearson and Lipman's similarity search method (Proc. Natl. Acad. Sci. USA 85:2444, 1988), computerized implementation of these algorithms (for example, GAP, BESTFIT, FASTA and TFASTA in Wisconsin Genetics Software Package, Genetics Computer Group, 575 Science Dr., Madison, Wis.) or by manual alignment and visual inspection (for example, see Ausubel et al., Current Protocols in Molecular Biology (1995 supplement)). Suitable algorithms for determining percent sequence identity and sequence similarity are the BLAST and BLAST 2.0 algorithms, which are described in Altschul et al. (Nuc. Acids Res. 25:3389-402, 1977) and Altschul et al. (J. Mol. Biol. 215:403-10, 1990), respectively. Software for performing BLAST analyses is publicly available from the National Center for Biotechnology Information (http: / / www.ncbi.nlm.nih.gov / ). This algorithm first identifies high-scoring sequence pairs (HSPs) by identifying short words of length W in the query sequence that match or meet a certain positive threshold score T when aligned with words of the same length in the database sequences. T is referred to as the neighborhood word score threshold (Altschul et al., supra).These initial neighborhood word hits act as seeds to initiate searches to find longer HSPs containing that word. The word hits are extended along each sequence in both directions for as far as the cumulative alignment score can be increased. The cumulative score is calculated using the parameters M (reward score for a matched residue; always >0) and N (penalty score for a mismatched residue; always <0) for nucleotide sequences. For amino acid sequences, a scoring matrix is ​​used to calculate the cumulative score. The extension of the word hits in each direction is stopped if: the cumulative alignment score falls by an amount X from its achieved maximum value; the accumulation of one or more negative scoring residue alignments causes the cumulative score to fall below 0; or the end of either sequence is reached. The BLAST algorithm parameters W, T, and X determine the sensitivity and speed of the alignment. The BLASTN program (for nucleotide sequences) uses as defaults a wordlength (W) of 11, an expectation (E) of 10, M=5, N=-4, and a comparison of both strands. For amino acid sequences, the BLASTP program uses as defaults a word length of 3, an expectation (E) of 10, the BLOSUM62 scoring matrix (see Henikoff and Henikoff, Proc. Natl. Acad. Sci. USA 89:10915, 1989), an alignment (B) of 50, an expectation (E) of 10, M=5, N=-4, and a comparison of both strands. The BLAST algorithm also performs a statistical analysis of the similarity between two sequences (see, e.g., Karlin and Altschul, Proc. Natl. Acad. Sci. USA 90:5873-87, 1993). One measure of similarity provided by the BLAST algorithm is the smallest sum probability (P(N)), which provides an indication of the probability that a match between two nucleotide or amino acid sequences would occur by chance. For example, a nucleic acid is considered to be similar to a reference sequence if the smallest sum probability in a comparison of the test and reference nucleic acids is less than about 0.2, typically less than about 0.01, and more typically less than about 0.001.

[0070] Semi-conservative and especially conservative amino acid substitutions are preferred in which an amino acid is replaced with a chemically related amino acid. Typical substitutions are between aliphatic amino acids, between amino acids with aliphatic hydroxyl side chains, between amino acids with acidic residues, between amide derivatives, between amino acids with basic residues or between amino acids with aromatic residues. Representative semi-conservative and conservative substitutions are as follows: [Table 1]

[0071] "Pharmaceutically acceptable" means approved by a regulatory agency of the Federal or state government or listed in the United States Pharmacopeia (United States Pharmacopeia-33 / National Formulary-28 Reissue, United States Pharmacopeia Convention, Inc, Rockville Md., publication date: April 2010) or other generally recognized agency for use in animals, and more particularly in humans.

[0072] The term "pharmaceutically acceptable salt" refers to a salt of the compound of the present invention. Suitable pharmaceutically acceptable salts of the compound of the present invention include, for example, acid addition salts that can be formed by mixing a solution of the compound described herein or its derivative with a solution of a pharmaceutically acceptable acid such as hydrochloric acid, sulfuric acid, fumaric acid, maleic acid, succinic acid, acetic acid, benzoic acid, citric acid, tartaric acid, carbonic acid or phosphoric acid. Furthermore, when the compound of the present invention carries an acidic moiety, suitable pharmaceutically acceptable salts thereof can include salts formed with alkali metal salts (e.g., sodium salt or potassium salt); alkaline earth metal salts (e.g., calcium salt or magnesium salt); and suitable organic ligands (e.g., ammonium, quaternary ammonium and amine cations formed with counter anions such as halides, hydroxides, carboxylates, sulfates, phosphates, nitrates, alkylsulfonates and arylsulfonates).Examples of pharma- ceutically acceptable salts include, but are not limited to, acetate, adipate, alginate, ascorbate, aspartate, benzenesulfonate, benzoate, bicarbonate, bisulfate, tartrate, borate, bromide, butyrate, calcium edetate, camphorate, camphorsulfonate, camsylate, carbonate, chloride, citrate, clavulanate, cyclopentanepropionate, digluconate, dihydrochloride, dodecylsulfate, edetate, edisylate, estholate, esylate, ethanesulfonate, formate, fumarate, glucaptate, glucoheptonate, gluconate, glutamate, glycerophosphate, glycolylsanilate, hemisulfinate, heptanoate, hexanoate, hexylresorcinate, hydrabamate, hydrobromide, hydrochloride, and hydroiodide. Acid salts, 2-hydroxyethanesulfonate, hydroxynaphthoate, iodide, isothioate, lactate, lactobionate, laurate, lauryl sulfate, malate, maleate, malonate, mandelate, mesylate, methanesulfonate, methylsulfate, mucate, 2-naphthalenesulfonate, napsylate, nicotinate, nitrate, N-methylglucamine ammonium salt, oleate, oxalate, pamoate (embonate), palmitate, pantothenate, pectinate, persulfate, 3-phenylpropionate, phosphate / diphosphate, picrate, pivalate, polygalacturonate, propionate, salicylate, stearate, sulfate, acetate, succinate, tannate, tartrate, theoclate, tosylate, triethiodide, undecanoate, valerate, etc. (e.g., Berge, (See SM, et al, "Pharmaceutical Salts", Journal of Pharmaceutical Science, 1977, 66, 1-19.) Certain compounds of the present invention contain both basic and acidic functionalities that allow the compounds to be converted into either base or acid addition salts.

[0073] The neutral forms of the compounds can be regenerated by contacting the salt with a base or acid and isolating the parent compound in the conventional manner. The parent form of the compound differs from the various salt forms in certain physical properties, such as solubility in polar solvents, but the salt forms are otherwise equivalent to the parent form of the compound for purposes of the invention.

[0074] In addition to salt forms, the present invention provides compounds that are isomers of the compounds defined by general formulas (I), (II), (III) and (IV). The term "isomer" includes structural and stereoisomers, including enantiomers, diastereomers, cis-trans isomers, conformational isomers and rotamers. In the context of the present invention, it is preferred that "isomer" is a stereoisomer (and not a structural isomer).

[0075] The present invention also provides solvates of the compounds defined by general formula (I), (II), (III) and (IV). The term "solvate" according to the present invention is understood to mean any form of a compound that has another molecule (e.g., a polar solvent) bound to it by non-covalent bonds. Examples of solvates include hydrates and alcoholates, such as methanolates and ethanolates. Solvation methods are generally known in the art.

[0076] The present invention further provides chemically protected forms of the compounds defined by general formulas (I), (II), (III) and (IV). At any point during the preparation of the compounds of the present invention, it may be necessary and / or desirable to protect sensitive or reactive sites on any of the molecules considered, thereby resulting in a chemically protected form of the present invention. This may be achieved by means of conventional protecting groups. The protecting groups may be removed at a convenient subsequent step using methods known in the art.

[0077] In addition to salt forms, the present invention provides compounds in prodrug form. Prodrugs of the compounds described herein are compounds that readily undergo chemical changes under physiological conditions to provide compounds of formulae (I)-(IV), particularly those shown in FIG. 14. Prodrugs are active or inactive compounds that are chemically modified to provide compounds of the present invention by in vivo physiological action, such as hydrolysis, metabolism, etc., following administration of the prodrug to a patient. Additionally, prodrugs can be converted to compounds of the present invention by chemical or biochemical methods in an ex vivo environment. For example, prodrugs are slowly converted to compounds of the present invention when placed in a transdermal patch reservoir with an appropriate enzyme. The suitability and techniques involved in the manufacture and use of prodrugs are well known to those skilled in the art. For a general discussion of prodrugs, including esters, see Svensson LA and Tunek A. (1988) Drug Metabolism Reviews 19(2): 165-194 and Bundgaard H. "Design of Prodrugs", Elsevier Science Ltd. (1985). Examples of masked carboxylate anions include various esters such as alkyl (e.g., methyl, ethyl), cycloalkyl (e.g., cyclohexyl), aralkyl (e.g., benzyl, p-methoxybenzyl), and alkylcarbonyloxyalkyl (e.g., pivaloyloxymethyl). Amines have been masked as arylcarbonyloxymethyl-substituted derivatives, which are cleaved by esterases in vivo to release the free drug and formaldehyde (Bundgaard H. et al. (1989) J. Med. Chem. 32(12): 2503-2507). Drugs containing acidic NH groups, such as imidazole, imide, and indole, have also been masked with N-acyloxymethyl groups (Bundgaard H. "Design of Prodrugs", Elsevier Science Ltd. (1985)). Hydroxy groups have been masked as esters and ethers. EP 0 039 051 A2 discloses Mannich-base hydroxamic acid prodrugs, their preparation and use.

[0078] Without wishing to be bound by any particular theory, the inventors believe that the active compound COVI-3 may be metabolized in vivo to COVI-86, which may then be further metabolized in vivo to the active compound COVI-87. Thus, COVI-86 may be viewed as a prodrug of the active compound COVI-87.

[0079] The compounds of the present invention may also contain unnatural proportions of atomic isotopes at one or more of the atoms that constitute such compounds. For example, the compounds may contain isotopes of, for example, tritium ( 3 H), Iodine-125( 125 I) or carbon-14 ( 14 C). All isotopic variations of the compounds of the present invention, whether radioactive or not, are intended to be encompassed within the scope of the present invention.

[0080] As used herein, "para-position" when referring to an aryl substituent means that the substituent occupies the position opposite the position at which the aryl is attached to the backbone of the compound.

[0081] As used herein, "patient" refers to any mammal or bird that may benefit from treatment with the compounds described herein. Preferably, the "patient" is selected from the group consisting of laboratory animals, domestic animals, or primates, including chimpanzees and humans. It is particularly preferred that the "patient" is a human.

[0082] As used herein, "treatment," "treat," or "treating" a disease or disorder means achieving one or more of the following: (a) lessening the severity of the disorder; (b) limiting or preventing the onset of symptoms characteristic of the disorder being treated; (c) inhibiting the worsening of symptoms characteristic of the disorder being treated; (d) limiting or preventing the recurrence of the disorder in a patient previously affected by the disorder; and (e) limiting or preventing the recurrence of symptoms in a patient previously affected by the disorder.

[0083] As used herein, "prevention," "prevent," "preventing," or "prevention" of a disease or disorder refers to preventing a disorder from occurring in a subject for a certain period of time. For example, when a compound described herein is administered to a subject for the purpose of preventing a disease or disorder, the disease or disorder is prevented from occurring at least on the day of administration, and preferably one or more days (e.g., 1-30 days; or 2-28 days; or 3-21 days; or 4-14 days; or 5-10 days) after the day of administration.

[0084] A "pharmaceutical composition" according to the invention may be in the form of a composition in which different active ingredients and diluents and / or carriers are mixed together or may take the form of a combined preparation in which the active ingredients are present in partially or completely different forms. An example of such a combination or combined preparation is a kit.

[0085] An "effective amount" is an amount of a therapeutic agent sufficient to achieve its intended purpose. The effective amount of a given therapeutic agent will vary depending on factors such as the nature of the therapeutic agent, the route of administration, the size and species of the animal to which the therapeutic agent is administered, and the purpose of administration. The effective amount in each case can be empirically determined by one of ordinary skill in the art according to methods established in the art.

[0086] The term "carrier" as used herein refers to a diluent, adjuvant, excipient, or vehicle with which the therapeutic agent is administered. Such pharmaceutical carriers can be sterile liquids such as saline in water and oils, including those of petroleum, animal, vegetable, or synthetic origin, for example, peanut oil, soybean oil, mineral oil, sesame oil, and the like. Saline is a preferred carrier when the pharmaceutical composition is administered intravenously. Aqueous dextrose and glycerol saline solutions can also be employed as liquid carriers, particularly for injectable solutions. Suitable pharmaceutical excipients include starch, glucose, lactose, sucrose, gelatin, malt, rice flour, chalk, silica gel, sodium stearate, glyceryl monostearate, talc, sodium chloride, dried skim milk, glycerol, propylene glycol, water, ethanol, and the like. The composition can also contain minor amounts of wetting or emulsifying agents, or pH buffering agents, if desired. These compositions can take the form of solutions, suspensions, emulsions, tablets, pills, capsules, powders, sustained release formulations, and the like. The compositions can be formulated as suppositories, using traditional binders and carriers, such as triglycerides. The compounds of the present invention can be formulated as neutral or salt forms. Pharmaceutically acceptable salts include those formed with free amino groups from hydrochloric acid, phosphoric acid, acetic acid, oxalic acid, tartaric acid, and the like, and those formed with free carboxyl groups from sodium, potassium, ammonium, calcium, ferric hydroxide, isopropylamine, triethylamine, 2-ethylaminoethanol, histidine, procaine, and the like. Examples of suitable pharmaceutical carriers are described in "Remington's Pharmaceutical Sciences" by EW Martin. Such compositions contain a therapeutically effective amount of the compound, preferably in purified form, together with a suitable amount of the carrier to provide the form for proper administration to the patient. The formulation should be appropriate for the mode of administration.

[0087] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The following paragraphs describe the elements of the present invention. Although these elements are listed with specific embodiments, it should be understood that they can be combined in any manner and in any number to create additional embodiments. The various described examples and preferred embodiments should not be construed to limit the invention to only the explicitly described embodiments. This specification should be understood to support and encompass embodiments combining the explicitly described embodiments with any number of the disclosed elements and / or preferred elements. Furthermore, any permutation and combination of all described elements in this application should be considered to be disclosed by the description of this application unless the context indicates otherwise.

[0088] The present inventors have identified and characterized a pocket in Nsp13 that is believed to be involved in the allosteric regulation of the ATPase activity of Nsp13. Compounds that specifically bind to this pocket can inhibit the ATPase activity of Nsp13. Compounds that bind to the ATPase site of Nsp13 and inhibit its ATPase activity must compete with ATP for binding to the ATPase site. Because cellular ATP concentrations range from 1 to 10 mM depending on the cellular compartment, very high binding affinities of subnanomolar levels are required to sufficiently inhibit ATP binding to the ATPase site of Nsp13. Compounds reported by Mirza and Froeyen (supra) and compounds reported by Ugurel et al. (supra), Gurung (supra) are reported to bind to the ATP binding site. In particular, Mirza and Froeyen report binding to residues 288, 289, 374, 375, 567, 178, 310, 312, 314, 378, and 539, whereas Gurung reports binding to amino acids 178, 284, 285, 286, 287, 288, 289, 290, 310, 312, 313, 316, 317, 320, 374, 375, 378, 404, 442, 443, 534, 535, 537, 538, 539, 540, 567, and 553. The binding sites for the previously reported compounds and ATP are distinct from the allosteric pocket by two loops, E144-Y150 and D171-P178. Thus, these amino acids can interact with both the ATP binding site and the allosteric pocket; indeed, D374, E375 and M378 are reported to interact with some of the ATP competitive compounds reported by Mirza and Froeyen and Gurung, and with the allosteric inhibitors reported by the present inventors. Allosteric inhibitors of Nsp13 do not have such limitations, as they do not need to inhibit ATP binding, but inhibit the ATPase activity of Nsp13 by a different mechanism. The present inventors have identified compounds that can specifically bind to the allosteric pocket and have determined the spatial and electronic requirements of compounds that fit into this pocket.Thus, by defining a "lock," we were able to define a "key" or compound that fits into this lock, i.e., allosteric binding pocket, and can form non-covalent or other stabilizing interactions to specifically bind to the pocket. Through this rational design approach, we have identified compounds that can inhibit the movement of Nsp13 on chromatin.

[0089] Structure-based computer modeling of ligand-protein interactions is now a core component of modern drug discovery (Charifson and Kuntz, 1997), and has played a key role in the discovery process of a growing number of marketed drugs, including HIV protease inhibitors (Charifson and Kuntz, 1997; Greer et al., 1994; Jorgensen, 2004) and zanamivir (an antiviral neuraminidase inhibitor) (von Itzstein et al., 1993), as well as the development of novel drug candidates such as HIV integrase inhibitors (Hazuda et al., 2004; Schames et al., 2004), Hepatitis C protease inhibitors (Liverton et al., 2008; Thomson and Perni, 2006), and β-secretase inhibitors (BACE-1) (Stauffer et al., 2007). There are three main classes of physical computational methods available in the field (from fastest to slowest, from low physics to high physics): (1) ultrafast molecular docking methods such as DOCK, Glide, AutoDock, FlexX, ICN, PMF and GOLD, free energy methods (MD) based on molecular dynamics such as MM / GBSA or MM / PBSA, where the solvent, protein and ligand are subjected to forces and thermal fluctuations on each other and move stepwise in response to these forces, (4) absolute binding free energy (ABFE) methods including alchemy simulations, which are the most expensive computational methods but include physics in the most rigorous way currently practical. ABFE methods start from the structure of the unbound ligand and potentially the unbound protein and attempt to predict the structure, affinity and thermal properties of the complex of interest. These strategies, known in the art, and especially the approach described in the experimental section, can be used to identify compounds that are allosteric inhibitors of ALC1 by binding to the allosteric binding pocket in ALC1 that was first identified by the inventors.

[0090] Thus, in a first aspect, the present invention relates to an inhibitor of the helicase activity of SARS-CoV-2 Nsp13 helicase (Nsp13) or its viral homologues, wherein the inhibitor specifically binds to an allosteric binding pocket within the N-terminal lobe of the ATPase domain of Nsp13 or its viral homologues.

[0091] The term "inhibitor of helicase activity" used in the context of the inhibitors of the present invention refers to the inhibition of the activity of the helicase of a virus of the class of positive strand RNA viruses, preferably of the class Pisoniviricetes, more preferably of the order Nidovirales, and even more preferably of the family Coronaviridae. To evaluate the ability of individual compounds to inhibit helicase activity, the helicase activity is preferably determined in a helicase unwinding assay using SARSCoV2 helicase Nsp13 having the amino acid sequence of SEQ ID NO: 1 as described herein. Such an assay preferably uses 0.15 nM Nsp13 and 100 nM dsDNA labeled with a pair of FRET labels to detect the unwinding of dsDNA. The unwinding reaction can be initiated by adding 200 μM ATP and 1 μM unlabeled single-stranded DNA. The inhibitors of the present invention have an IC 50 is 100 μM or less, more preferably IC 50 is 50 μM or less, and more preferably IC 50 ≤ 20 μM, most preferably IC 50 It is preferable that the helicase activity is inhibited at a concentration of 10 μM or less.

[0092] The term "viral homolog" of SARS-CoV-2 Nsp13 having the amino acid sequence of SEQ ID NO:1 refers to a viral protein that is a functional homolog, i.e. that exhibits helicase activity in a chromatin remodeling assay as used in the examples of the present invention (see Example 3). Preferably, the term refers to a protein that is a functional and structural homolog of SARS-CoV-2 Nsp13. The structural homology is preferably within the amino acids of the viral homolog that form the allosteric pocket of the helicase. The inventors have used molecular dynamics (MD) simulations of the first lobe of SARS-CoV-1 Nsp13 helicase (residues 236 to 440 of the publicly available SARS-CoV-1 Nsp13 PDB: 6JYT, see Example 1) to identify a yet unidentified allosteric binding pocket within Nsp13. The allosteric binding pocket to which the helicase inhibitors of the present invention bind is formed by amino acids 236 to 440 of Nsp13 of SEQ ID NO:1. However, not all amino acids within the amino acid stretch spanning amino acid residues 236 to 440 of SEQ ID NO:1 form a surface of the allosteric pocket of Nsp13 available for the binding of inhibitors of the invention. This is due to the fact that some amino acids are buried in the pocket and are poorly accessible, while other amino acids are not even part of the pocket but are located within Nsp13 or on the outer surface of Nsp13. The surface region of this allosteric binding pocket of Nsp13 is formed by the following amino acids (see SEQ ID NO:1): Y277, T279, L280, Q281, G282, T307, C309, F373, D374, E375, I376, S377, M378, A379, L384, N388, Y396, Y398, I399, G400, D401, P406, P408, N423, V425, C426, R427 and M429.Among these residues, amino acids Y277, L384, N388, Y396, Y398 and V425 form an entry channel into the pocket through which the inhibitors of the present invention can enter the binding pocket, and amino acids T307, C309, F373, D374, E375, S377, M378, A379 and N423 form the left channel, and T279, L280, Q281, G282, I376, I399, G400, D401, P406, P408, C426, R427 and M429 form the right channel. Thus, preferred viral homologs constitute binding pockets of similar structure, which can be evaluated using MD as described below. Preferred structural homologs are those that contain identical or conservatively or semi-conservatively substituted amino acids at at least 50% of the amino acid positions corresponding to amino acids Y277, T279, L280, Q281, G282, T307, C309, F373, D374, E375, I376, S377, M378, A379, L384, N388, Y396, Y398, I399, G400, D401, P406, P408, N423, V425, C426, R427 and M429 of SEQ ID NO:1. Preferred structural homologs contain identical or conservatively or semi-conservatively substituted amino acids at at least 60%, 70%, 80% of the amino acid positions corresponding to Y277, T279, L280, Q281, G282, T307, C309, F373, D374, E375, I376, S377, M378, A379, L384, N388, Y396, Y398, I399, G400, D401, P406, P408, N423, V425, C426, R427, and M429 of the amino acid sequence of SEQ ID NO: 1. Particularly preferred structural viral helicase homologs share at least 60%, at least 70%, more preferably at least 80%, and even more preferably at least 90% with AA277 to M429 of Nsp13 having the amino acid sequence of SEQ ID NO: 1. Exemplary preferred viral homologs of SARS-CoV-2 Nsp13 are shown in FIG. 3 and depicted in the accompanying sequence listing as SEQ ID NOs: 2-7.

[0093] The term "corresponding position" is used in the context of the present invention to refer to an amino acid position in the amino acid sequence of a given protein (e.g., a helicase homologue of Nsp13 of SEQ ID NO: 1) that is aligned with a reference protein, and in particular Nsp13 of SARSCoV2 of SEQ ID NO: 1 that is aligned with the amino acid of the reference protein. The alignment of two or more amino acid sequences can be performed using many publicly available software tools, including Clustal Omega (https: / / www.ebi.ac.uk / Tools / msa / clustalo / ) or PBLAST, in each case using standard alignment parameters. An example of such an alignment with Nsp13 of SARSCoV2 of SEQ ID NO: 1 and helicases of six related RNA viruses is shown in FIG. 3. Based on such an alignment, the skilled person can easily determine the amino acid that corresponds to one of the amino acids specifically indicated above and below with reference to Nsp13 of SARSCoV2 of SEQ ID NO: 1. For example, Y277 of SARSCoV2 aligns with I278 of SARSCoV (SEQ ID NO: 2), designated "229E" in Figure 3, with I278 of the Nsp13 helicase of HCoV-NL63 (SEQ ID NO: 3), designated "NL-63" in Figure 3, with Y276 of the Nsp13 helicase of HCoV HKU1 (SEQ ID NO: 5), designated "OC43" in HCoV OC43 (SEQ ID NO: 4), designated "NL-63" in Figure 3, with Y277 of the Nsp13 helicase of MERS CoV (SEQ ID NO: 6), designated "HKU1" in the figure, and with Y277 of the Nsp13 helicase of SARS CoV (SEQ ID NO: 7).

[0094] Thus, in one embodiment of the first aspect (i) the N-terminal lobe of the ATPase domain consists of amino acid residues 236 to 440 of SEQ ID NO:1, or the corresponding amino acid residues of a viral homologue; and / or (ii) the allosteric binding pocket comprises or consists of the amino acids at the corresponding positions of Y277, T279, L280, Q281, G282, T307, C309, F373, D374, E375, I376, S377, M378, A379, L384, N388, Y396, Y398, I399, G400, D401, P406, P408, N423, V425, T426, R427 and M429 of SEQ ID NO: 1 or viral homologues of Nsp13. These are amino acids whose side chains and / or backbones form the surface of the binding pocket and therefore can form non-covalent bonds with inhibitors of the invention.

[0095] In a further embodiment of the first aspect, the allosteric binding pocket is a tripartite structure, comprising an entry channel (1), a left channel (2) and a right channel (3), and is located behind the active site of Nsp13 or its viral homologues. It can be seen in Figures 5 to 7 and 10. The allosteric inhibitors of the invention specifically bind, preferably non-covalently, to amino acids in one or more of the entry channel (1), the left channel (2) and the right channel (3), thereby inhibiting allosteric activation of the helicase.

[0096] In a further embodiment of the first aspect, the inhibitor specifically binds to one or more (e.g. 1, 2, 3, 4, 5, 6 or all 7) of the following 7 amino acid residues in the allosteric binding pocket of Nsp13 of SARSCoV2 of SEQ ID NO:1 or amino acids at corresponding positions in a viral homologue of Nsp13: F373, I376, L384, Y398, I399, V425 and M429.

[0097] In a further embodiment of the first aspect, the inhibitor specifically binds to at least one of the following seven pairs of amino acids within the allosteric binding pocket: (i) in the entry channel, at least one amino acid residue selected from N381, L384, S385, V387, N388 and V425 of Nsp13 of SARSCoV2 of SEQ ID NO: 1 or the backbone of the amino acid at the corresponding position in a viral homologue of Nsp13 and / or one or more of the side chains of amino acid residues selected from P238, T239, Y277, N381, L384, S385, V387, N388, Y396, Y398, N423 and V425 of Nsp13 of SARSCoV2 of SEQ ID NO: 1 or the side chain of the amino acid at the corresponding position in a viral homologue of Nsp13;

[0098] (ii) in the right channel, one or more of the backbone chains of at least one amino acid residue selected from L280, T279, Q281, G282, T307, C309, F373, Y398, I399, G400, D401, P406, P408, V425, C426 and R427 of Nsp13 of SARSCoV2 of SEQ ID NO: 1 or the amino acid at the corresponding position in a viral homologue of Nsp13 and / or the side chains of amino acid residues selected from L280, Q281, F373, I376, I399, G400, P406, P408, N423, C426 and M429 of Nsp13 of SARSCoV2 of SEQ ID NO: 1 or the amino acid at the corresponding position in a viral homologue of Nsp13;

[0099] (iii) in the left channel, the backbone of an amino acid residue selected from T279, E375, I376, S377, M378, A379, P408 and M429 of Nsp13 of SARSCoV2 of SEQ ID NO: 1 or an amino acid at a corresponding position in a viral homologue of Nsp13 and / or one or more side chains of an amino acid residue selected from T307, C309, F373, D374, I376, M378, A379, L384 and N423 of Nsp13 of SARSCoV2 of SEQ ID NO: 1 or an amino acid at a corresponding position in a viral homologue of Nsp13;

[0100] (iv) in the right channel and in the entry channel, at least one amino acid residue selected from L280, T279, Q281, G282, T307, C309, F373, N381, L384, S385, V387, N388, Y398, I399, G400, D401, P406, P408, V425, C426 and R427 of Nsp13 of SARSCoV2 of SEQ ID NO: 1 or the corresponding positions in viral homologues of Nsp13 and / or one or more of the amino acid backbones selected from P238, T239, Y277, L280, Q281, F373, I376, N381, L384, S385, V387, N388, Y396, Y398, I399, G400, P406, P408, N423, V425, C426 and M429 of Nsp13 of SARSCoV2 of SEQ ID NO: 1 or the side chains of the amino acids at the corresponding positions of viral homologues of Nsp13;

[0101] (v) in the left channel and in the entry channel, the backbone of the amino acid residues selected from T279, E375, I376, S377, M378, A379, N381, L384, S385, V387, N388, P408, V425 and M429 of Nsp13 of SARSCoV2 of SEQ ID NO: 1 or the amino acids at the corresponding positions in the viral homologues of Nsp13 and / or one or more of the amino acid residues selected from P238, T239, Y277, T307, C309, F373, D374, I376, M378, A379, N381, L384, S385, V387, N388, Y396, Y398, N423 and V425 of Nsp13 of SARSCoV2 of SEQ ID NO: 1, or the side chains of the amino acids at corresponding positions in viral homologues of Nsp13;

[0102] (vi) in the left and right channels, amino acid residues selected from T279, L280, Q281, G282, T307, C309, F373, E375, I376, S377, M378, A379, Y398, I399, G400, D401, P406, P408, V425, C426, R427, M429 of Nsp13 of SARSCoV2 of SEQ ID NO: 1 or in a viral homologue of Nsp13 one or more of the amino acid backbones at corresponding positions and / or the amino acid side chains at corresponding positions in viral homologues of Nsp13 selected from L280, Q281, T307, C309, F373, D374, I376, M378, A379, L384, I399, G400, P406, P408, N423, C426, M429 of Nsp13 of SARSCoV2 of SEQ ID NO: 1; and / or

[0103] (vii) in the left channel, right channel and entry channel, an amino acid residue selected from T279, L280, Q281, G282, T307, C309, F373, E375, I376, S377, M378, A379, N381, L384, S385, V387, N388, Y398, I399, G400, D401, P406, P408, V425, C426, R427 and M429 of Nsp13 of SARSCoV2 of SEQ ID NO: 1 or a viral homologue of Nsp13 The backbone of the amino acids at the corresponding positions in the log and the side chains of residues P238, T239, Y277, L280, Q281, T307, C309, F373, D374, I376, M378, A379, N381, L384, S385, V387, N388, Y396, Y398, I399, G400, P406, P408, N423, V425, C426 and M429 of Nsp13 of SARSCoV2 of SEQ ID NO: 1 or the amino acids at the corresponding positions in viral homologues of Nsp13.

[0104] In a further embodiment of the first aspect, the inhibitor specifically binds to: (a) the amino acids set out in (i) above and Y277 of Nsp13 of SARSCoV2 of SEQ ID NO:1 or the amino acid at the corresponding position in a viral homologue of Nsp13, where the inhibitor binds to the aromatic ring of Y277 via face-to-face or end-to-face π-π interactions with an aromatic carbo or heterocyclic substituent, or the inhibitor binds to Y277 by a cation-π, polar-π or halogen-π interaction with a polar, charged or carbohalogen substituent; or the terminal oxygen of Y277 interacts with a hydrogen bond donor group; N388 of Nsp13 of SARSCoV2 of SEQ ID NO:1 or the amino acid at the corresponding position in a viral homologue of Nsp13, where the inhibitor binds to the side chain on N388 via a hydrogen bond donor or acceptor group; Y39 of Nsp13 of SARSCoV2 of SEQ ID NO:1 6 or an amino acid at a corresponding position in a viral homologue of Nsp13, where the inhibitor binds to the aromatic ring of Y396 via a face-to-face or end-to-face π-π interaction with an aromatic carbo- or heterocyclic substituent or where Y396 forms a cation-π, polar-π or halogen-π interaction with a polar, charged or carbohalogen substituent; and Y398 of Nsp13 of SARSCoV2 of SEQ ID NO: 1 or an amino acid at a corresponding position in a viral homologue of Nsp13, where the inhibitor binds to the aromatic ring of Y398 via a face-to-face or end-to-end π-π interaction with an aromatic carbon- or heterocyclic substituent or where Y396 forms a cation-π, polar-π or halogen-π interaction with a polar, charged or carbon-halogen substituent;

[0105] (b) the amino acids shown in (ii) above and L280 of Nsp13 of SARSCoV2 of SEQ ID NO: 1 or an amino acid at a corresponding position in a viral homologue of Nsp13, where the inhibitor binds to the backbone N of the amino acid at L280 of Nsp13 of SARSCoV2 of SEQ ID NO: 1 or a corresponding position in a viral homologue of Nsp13, where the inhibitor binds to the backbone N of the amino acid at L280 of Nsp13 of SARSCoV2 of SEQ ID NO: 1 or a corresponding position in a viral homologue of Nsp13, where the inhibitor binds to the backbone N of the amino acid at Y398 ... the agent binds to the aromatic ring of Y398 via face-to-face or edge-to-face π-π interactions with aromatic carbo or heterocyclic substituents or via cation-π, polar-π or halogen-π interactions with polar, charged or carbohalogen substituents; I399 of Nsp13 of SARSCoV2 of SEQ ID NO: 1 or an amino acid at the corresponding position in a viral homologue of Nsp13, where the inhibitor binds to the main chain carbonyl oxygen of I399 by a carbohalogen or hydrogen bond donor group or interacts with a hydrogen bond acceptor; 1, where the inhibitor binds to the main chain N of I399 interacting with it; G400 of Nsp13 of SARSCoV2 of SEQ ID NO: 1 or an amino acid at a corresponding position in a viral homologue of Nsp13, where the inhibitor binds to the main chain N of G400 with a hydrogen bond acceptor group or to the main chain carbonyl oxygen of G400 with a carbohalogen or hydrogen bond donor group; D401 of Nsp13 of SARSCoV2 of SEQ ID NO: 1 or an amino acid at a corresponding position in a viral homologue of Nsp13, where the inhibitor binds to the main chain N of G400 with a hydrogen bond acceptor group or to the main chain carbonyl oxygen of G400 with a carbohalogen or hydrogen bond donor group; a carbonyl oxygen of D401 bearing a halogen or hydrogen bond donor group; P406, where the inhibitor binds to the main chain carbonyl oxygen of P406 bearing a halogen or hydrogen bond donor group; and one further amino acid selected from the group consisting of C426 of Nsp13 of SARSCoV2 or an amino acid at the corresponding position of a viral homologue of Nsp13 of SEQ ID NO: 1, where the inhibitor binds to the S of C426 bearing a carbohalogen group or the S of C426 forms a covalent bond to the "warhead" of the inhibitor;

[0106] (c) the amino acids indicated in (iii) above and T307 of Nsp13 of SARSCoV2 of SEQ ID NO:1 or the corresponding position in a viral homologue of Nsp13, where the inhibitor binds to the side chain of T307 with a hydrogen bond donor or acceptor group or the inhibitor binds to the main chain carbonyl oxygen of T307 with a carbohalogen or hydrogen bond donor group; F373 of Nsp13 of SARSCoV2 of SEQ ID NO:1 or the corresponding position in a viral homologue of Nsp13, where the inhibitor binds to the aromatic ring of F373 via face- or end-face π-π interactions with an aromatic carbo or heterocyclic substituent or via cation-π, polar-π or halogen-π interactions with a polar, charged or carbohalogen substituent; C309 of Nsp13 of SARSCoV2 of SEQ ID NO:1 or the corresponding position in a viral homologue of Nsp13, where the inhibitor binds to the C30 with a carbohalogen 9 or S of C309 forms a covalent bond to the "warhead" of the inhibitor); an amino acid at a corresponding position in SEQ ID NO:1 or a viral homologue of Nsp13, where the inhibitor binds to the side chain of D374 with a hydrogen bond donor or acceptor group; an amino acid at a corresponding position in E375 of Nsp13 of SARSCoV2 of SEQ ID NO:1 or a viral homologue of Nsp13, where the inhibitor binds to the main chain carbonyl oxygen of E375 with a carbohalogen or a hydrogen bond donor group; an amino acid at a corresponding position in I376 of Nsp13 of SARSCoV2 of SEQ ID NO:1 or a viral homologue of Nsp13, where the inhibitor binds to the main chain carbonyl oxygen of I376 with a carbon halide or a hydrogen bond donor group; an amino acid at a corresponding position in M378 of Nsp13 of SARSCoV2 of SEQ ID NO:1 or a viral homologue of Nsp13, where the inhibitor binds to the main chain N of M378 with a hydrogen bond acceptor group;and one further amino acid selected from the group consisting of A379 of Nsp13 of SARSCoV2 of SEQ ID NO:1 or an amino acid at the corresponding position in a viral homologue of Nsp13, where the inhibitor binds to the main chain carbonyl oxygen of A379 with a carbohalogen or hydrogen bond donor group or binds to the main chain N of A379 with a hydrogen bond acceptor group;

[0107] (d) the amino acids shown in (iv) above and Y277 of Nsp13 of SARSCoV2 of SEQ ID NO:1 or the amino acid at the corresponding position in a viral homologue of Nsp13, where the inhibitor binds to the aromatic ring of Y277 via face-to-face or edge-to-face π-π interactions with an aromatic carbo or heterocyclic substituent, or via cation-π, polar-π or halogen-π interactions with a polar, charged or carbohalogen substituent, or the inhibitor binds to the terminal oxygen of Y277 with a hydrogen bond donor group; ); L280 of Nsp13 of SARSCoV2 of SEQ ID NO:1 or an amino acid at a corresponding position in a viral homologue of Nsp13, where the inhibitor binds to the main chain N of L280 with a hydrogen bond acceptor group; N388 of Nsp13 of SARSCoV2 of SEQ ID NO:1 or an amino acid at a corresponding position in a viral homologue of Nsp13, where the inhibitor binds to the side chain of N388 with a hydrogen bond donor or acceptor group; Y396 of Nsp13 of SARSCoV2 of SEQ ID NO:1 or an amino acid at a corresponding position in a viral homologue of Nsp13, where the inhibitor binds to the side chain of N388 with a hydrogen bond donor or acceptor group; an amino acid at a corresponding position in a viral homologue, where the inhibitor binds to the aromatic ring of Y396 via face-to-face or end-to-face π-π interactions with an aromatic carbo or heterocyclic substituent or via cation-π, polar-π or halogen-π interactions with a polar, charged or carbohalogen substituent; an amino acid at a corresponding position in Nsp13 of SARSCoV2 SEQ ID NO:1, where the inhibitor binds to the aromatic ring of Y398 via face-to-face or end-to-face π-π interactions with an aromatic carbo or heterocyclic substituent or via cation-π, polar-π or halogen-π interactions with a polar, charged or carbohalogen substituent; an amino acid at a corresponding position in Nsp13 of SARSCoV2 SEQ ID NO:1, where the inhibitor binds to the main chain carbonyl oxygen of I399 with a carbohalogen or hydrogen bond donor group or to the main chain N of I399 with a hydrogen bond acceptor group;G400 of Nsp13 of SARSCoV2 of SEQ ID NO:1 or an amino acid at the corresponding position in a viral homologue of Nsp13, where the inhibitor binds to the main chain N of G400 with a hydrogen bond acceptor group or the main chain carbonyl oxygen of G400 with a carbohalogen or hydrogen bond donor group; D401 of Nsp13 of SARSCoV2 of SEQ ID NO:1 or an amino acid at the corresponding position in a viral homologue of Nsp13, where the inhibitor binds to the main chain carbonyl oxygen of D401 with a carbon halide or hydrogen bond donor group. an amino acid at the corresponding position in a viral homologue of Nsp13, wherein the inhibitor binds to the main chain carbonyl oxygen of P406 with a halogenated carbon or a hydrogen bond donor group; and one further amino acid selected from the group consisting of: an amino acid at the corresponding position in a viral homologue of Nsp13, wherein the inhibitor binds to the S of C426 with a carbohalogen or the S of 426 forms a covalent bond to the inhibitor "warhead";

[0108] (e) the amino acid indicated in (v) above and further the amino acid at the corresponding position in Y277 of Nsp13 of SARSCoV2 of SEQ ID NO: 1 or a viral homologue, where the inhibitor binds to the aromatic ring of Y277 via face-to-face or end-to-face π-π interactions with an aromatic carbo or heterocyclic substituent or via cation-π, polar-π or halogen-π interactions with a polar, charged or carbohalogen substituent, or the inhibitor binds to the terminal oxygen of Y277 bearing a hydrogen bond donor group; the SARSC of SEQ ID NO: 1 an amino acid at the corresponding position in N388 of Nsp13 of SARSCoV2 or a viral homologue, where the inhibitor binds to the side chain of N388 with a hydrogen bond donor or acceptor group; an amino acid at the corresponding position in Nsp13 of SARSCoV2 of SEQ ID NO: 1, where the inhibitor binds to the side chain of T307 with a hydrogen bond donor or acceptor group or to the main chain carbonyl oxygen of T307 with a carbohalogen or hydrogen bond donor group; an amino acid at the corresponding position in Nsp13 of SARSCoV2 of SEQ ID NO: 1, where the inhibitor binds to the side chain of T307 with a hydrogen bond donor or acceptor group or to the main chain carbonyl oxygen of T307 with a carbohalogen or hydrogen bond donor group; F373 or an amino acid at a corresponding position in a viral homologue of Nsp13, where the inhibitor binds to the aromatic ring of F373 via face-to-face or edge-to-face π-π interactions with an aromatic carbo or heterocyclic substituent, or via cation-π, polar-π or halogen-π interactions with a polar, charged or carbohalogen substituent; C309 of Nsp13 of SARSCoV2 of SEQ ID NO: 1 or an amino acid at a corresponding position in a viral homologue of Nsp13, where the inhibitor binds to the aromatic ring of F373 via face-to-face or edge-to-face π-π interactions with an aromatic carbo or heterocyclic substituent, or via cation-π, polar-π or halogen-π interactions with a polar, charged or carbohalogen substituent; or S at C309 forms a covalent bond to the "warhead" of the inhibitor; D374 of Nsp13 of SARSCoV2 of SEQ ID NO:1 or an amino acid at the corresponding position in a viral homologue of Nsp13, where the inhibitor binds to the side chain of D374 with a hydrogen bond donor or acceptor group; E375 of Nsp13 of SARSCoV2 of SEQ ID NO:1 or an amino acid at the corresponding position in a viral homologue of Nsp13, where the inhibitor binds to the main chain carbonyl oxygen of E375 with a carbohalogen or hydrogen bond donor group;I376 of SARSCoV2 of SEQ ID NO:1 or an amino acid at the corresponding position in a viral homologue of Nsp13, where the inhibitor binds to the main chain carbonyl oxygen of I376 with a carbohalogen or hydrogen bond donor group; M378 of Nsp13 of SARSCoV2 of SEQ ID NO:1 or an amino acid at the corresponding position in a viral homologue of Nsp13, where the inhibitor binds to the main chain N of M378 with a hydrogen bond acceptor group; A379 of Nsp13 of SARSCoV2 of SEQ ID NO:1 or an amino acid at the corresponding position in a viral homologue, where the inhibitor binds to the main chain carbonyl oxygen of A379 with a carbohalogen or hydrogen bond donor group or binds to the main chain N of A379 with a hydrogen bond acceptor group; Y39 of Nsp13 of SARSCoV2 of SEQ ID NO:1 6 or a corresponding position in a viral homologue of Nsp13, where the inhibitor binds to the aromatic ring of Y396 via face-to-face or end-to-face π-π interactions with an aromatic carbo or heterocyclic substituent or via cation-π, polar-π or halogen-π interactions with a polar, charged or carbohalogen substituent; and Y398 of Nsp13 of SARSCoV2 of SEQ ID NO: 1 or an amino acid at a corresponding position in a viral homologue of Nsp13, where the inhibitor binds to the aromatic ring of Y398 via face-to-face or end-to-face π-π interactions with an aromatic carbo or heterocyclic substituent or via cation-π, polar-π or halogen-π interactions with a polar, charged or carbohalogen substituent;

[0109] (f) the amino acids shown in (vi) above and L280 of Nsp13 of SARSCoV2 of SEQ ID NO:1 or an amino acid at a corresponding position in a viral homologue of Nsp13, where the inhibitor binds to the main chain N of L280 with a hydrogen bond acceptor group; T307 of Nsp13 of SARSCoV2 of SEQ ID NO:1 or an amino acid at a corresponding position in a viral homologue of Nsp13, where the inhibitor binds to the side chain of T307 with a hydrogen bond donor or acceptor group or to the main chain carbonyl of T307 with a carbohalogen or hydrogen bond donor group; F373 of Nsp13 of SARSCoV2 of SEQ ID NO: 1 or an amino acid at the corresponding position in a viral homologue of Nsp13 (wherein the inhibitor binds to the aromatic ring of F373 via face-to-face or edge-to-face π-π interactions with an aromatic carbo or heterocyclic substituent or via cation-π, polar-π or halogen-π interactions with a polar, charged or carbohalogen substituent); C309 (wherein the inhibitor binds to the S of C309 that bears a carbohalogen or the S of C309 that provides a covalent bond to the "warhead" of the inhibitor). D374 of Nsp13 of SARSCoV2 of SEQ ID NO:1 or an amino acid at a corresponding position in a viral homologue of Nsp13, where the inhibitor binds to the side chain of D374 with a hydrogen bond donor or acceptor group; E375, where the inhibitor binds to the main chain carbonyl oxygen of E375 with a carbohalogen or a hydrogen bond donor group; I376 of Nsp13 of SARSCoV2 of SEQ ID NO:1 or an amino acid at a corresponding position in a viral homologue of Nsp13, where the inhibitor binds to the main chain carbonyl oxygen of I376 with a halogenated carbon or a hydrogen bond donor group. M378 of Nsp13 of SARSCoV2 of SEQ ID NO: 1 or an amino acid at a corresponding position in a viral homologue of Nsp13, where the inhibitor binds to the main chain N of M378 with a hydrogen bond acceptor group; A379 of Nsp13 of SARSCoV2 of SEQ ID NO: 1 or an amino acid at a corresponding position in a viral homologue of Nsp13, where the inhibitor binds to the main chain carbonyl oxygen of A379 with a carbohalogen or hydrogen bond donor group or binds to the main chain N of A379 with a hydrogen bond acceptor group;Y398 of Nsp13 of SARSCoV2 of SEQ ID NO:1 or an amino acid at a corresponding position in a viral homologue of Nsp13, where the inhibitor binds to the aromatic ring of Y398 via face-to-face or edge-to-face π-π interactions with an aromatic carbo or heterocyclic substituent or via cation-π, polar-π or halogen-π interactions with a polar, charged or carbohalogen substituent; I399 of Nsp13 of SARSCoV2 of SEQ ID NO:1 or an amino acid at a corresponding position in a viral homologue of Nsp13, where the inhibitor binds to the main chain carbonyl oxygen of I399 with a carbohalogen or hydrogen bond donor group or to the main chain N of I399 with a hydrogen bond acceptor group; G400 of Nsp13 of SARSCoV2 of SEQ ID NO:1 or an amino acid at a corresponding position in a viral homologue of Nsp13, where the inhibitor binds to the hydrogen bond acceptor group at the main chain carbonyl oxygen of I399 with a carbohalogen or hydrogen bond donor group; or an amino acid at the corresponding position in a viral homologue of Nsp13 of SARSCoV2 of SEQ ID NO: 1, where the inhibitor binds to the main chain carbonyl oxygen of D401 with a halogenated carbon or a hydrogen bond donor group; P406, where the inhibitor binds to the main chain carbonyl oxygen of P406 with a halogenated carbon or a hydrogen bond donor group; and one further amino acid selected from the group consisting of C426 of Nsp13 of SARSCoV2 of SEQ ID NO: 1, where the inhibitor binds to the S of C426 with a carbohalogen or the S of 426 forms a covalent bond to the inhibitor's "warhead"; or

[0110] (g) the amino acids set forth in (vii) above and the amino acid at the corresponding position in Y277 of Nsp13 of SARSCoV2 of SEQ ID NO:1 or a viral homologue of Nsp13, wherein the inhibitor binds to the aromatic ring of Y277 via face-to-face or edge-to-face π-π interactions with an aromatic carbo or heterocyclic substituent, or via cation-π, polar-π or halogen-π interactions with a polar, charged or carbohalogen substituent, or the inhibitor binds to the terminal oxygen of Y277 bearing a hydrogen bond donor group; an amino acid at N388 of Nsp13 of SARSCoV2 of SEQ ID NO: 1 or at a corresponding position in a viral homologue of Nsp13, where the inhibitor binds to the side chain of N388 with a hydrogen bond donor or acceptor group; an amino acid at Y396 of Nsp13 of SARSCoV2 of SEQ ID NO: 1 or at a corresponding position in a viral homologue of Nsp13, where the inhibitor binds to the side chain of N388 with a hydrogen bond donor or acceptor group; or an amino acid at a corresponding position in a viral homologue of Nsp13 of SEQ ID NO: 1, where the inhibitor binds to the main chain N of L280 with a hydrogen bond acceptor group; or an amino acid at a corresponding position in a viral homologue of Nsp13 of SEQ ID NO: 1, where the inhibitor binds to the main chain N of L280 with a hydrogen bond donor or acceptor group; or an amino acid at a corresponding position in a viral homologue of Nsp13 of SEQ ID NO: 1, where the inhibitor binds to the main chain N of T307 with a hydrogen bond donor or acceptor group; 7 or attached to the main chain carbonyl oxygen of T307 with a carbohalogen or hydrogen bond donor group; F373 of Nsp13 of SARSCoV2 of SEQ ID NO: 1 or an amino acid at the corresponding position in a viral homologue of Nsp13 (wherein the inhibitor binds to the aromatic ring of F373 via face-to-face or edge-to-face π-π interactions with an aromatic carbo or heterocyclic substituent or via cation-π, polar-π or halogen-π interactions with a polar, charged or carbohalogen substituent);C309 of Nsp13 of SARSCoV2 of SEQ ID NO:1 or an amino acid at a corresponding position in a viral homologue of Nsp13, where the inhibitor binds to S of C309 bearing a carbohalogen or S of C309 forms a covalent bond to the "warhead" of the inhibitor; D374 of Nsp13 of SARSCoV2 of SEQ ID NO:1 or an amino acid at a corresponding position in a viral homologue of Nsp13, where the inhibitor binds to the side chain of D374 with a hydrogen bond donor or acceptor; E375 of Nsp13 of SARSCoV2 of SEQ ID NO:1 or an amino acid at a corresponding position in a viral homologue of Nsp13, where the inhibitor binds to the main chain carbonyl oxygen of E375 with a carbohalogen or hydrogen bond donor group; an amino acid at a corresponding position in I376 of Nsp13 of SARSCoV2 of SEQ ID NO:1 or a viral homologue of Nsp13, where the inhibitor binds to the main chain carbonyl oxygen of I376 with a halocarbon or hydrogen bond donor group; an amino acid at a corresponding position in M378 of Nsp13 of SARSCoV2 of SEQ ID NO:1 or a viral homologue of Nsp13 no acid, where the inhibitor binds to the backbone N of M378 with a hydrogen bond acceptor group; A379 of Nsp13 of SARSCoV2 of SEQ ID NO: 1 or an amino acid at the corresponding position in a viral homologue of Nsp13, where the inhibitor binds to the backbone carbonyl oxygen of A379 with a carbohalogen or hydrogen bond donor group or binds to the backbone N of A379 with a hydrogen bond acceptor group; Y398 of Nsp13 of SARSCoV2 of SEQ ID NO: 1 or an amino acid at the corresponding position in a viral homologue of Nsp13, where the inhibitor binds to the aromatic ring of Y398 via face-to-face or edge-to-face π-π interactions with aromatic carbo or heterocyclic substituents or via cation-π, polar-π or halogen-π interactions with polar, charged or carbohalogen substituents; I399 of Nsp13 of SARSCoV2 of SEQ ID NO:1 or an amino acid at the corresponding position in a viral homologue of Nsp13 (wherein the inhibitor binds to the main chain carbonyl oxygen of I399 with a carbohalogen or hydrogen bond donor group or to the main chain N of I399 with a hydrogen bond acceptor group);G400 of Nsp13 of SARSCoV2 of SEQ ID NO:1 or an amino acid at the corresponding position in a viral homologue of Nsp13, where the inhibitor binds to the main chain N of G400 with a hydrogen bond acceptor group or to the main chain carbonyl oxygen of G400 with a carbohalogen or hydrogen bond donor group; D401 of Nsp13 of SARSCoV2 of SEQ ID NO:1 or an amino acid at the corresponding position in a viral homologue of Nsp13, where the inhibitor binds to the main chain N of G400 with a hydrogen bond acceptor group or to the main chain carbonyl oxygen of G400 with a carbohalogen or hydrogen bond donor group; to the main chain carbonyl oxygen of D401 with a bond donor group; P406 of Nsp13 of SARSCoV2 or an amino acid at the corresponding position of a viral homologue of Nsp13 of SEQ ID NO: 1, where the inhibitor is attached to the main chain carbonyl oxygen of P406 with a carbohalogen or hydrogen bond donor group; and one further amino acid selected from the group consisting of C426, where the inhibitor is attached to the S of C426 with a carbohalogen or where the S of 426 forms a covalent bond to the "warhead" of the inhibitor;

[0111] One skilled in the art can use a 3D model of Nsp13 or a homolog thereof or at least a 3D model of the binding pocket and in silico modelling to determine chemical groups capable of forming the above indicated bonds with the above amino acids of the binding pocket or chemical groups within the above amino acids (see also Example 1).

[0112] In certain embodiments of the first aspect, the inhibitor is an organic molecule having a molecular weight in the range of 200-700 Da.

[0113] In certain embodiments of the first aspect, the inhibitor has a structure and stereoelectronic properties that are complementary to the allosteric binding pocket. An inhibitor structure is considered complementary if it can enter into the binding pocket and fit into the tripartite structure of the binding pocket. Examples of inhibitors that have a structure and stereoelectronic properties that are complementary to the allosteric binding pocket and therefore fit into the binding pocket are shown in FIG. 7. The location of an exemplary compound that has a structure and stereoelectronic properties that are complementary to the allosteric binding pocket is also shown in FIG. 9. FIG. 11 is a 2D view of the binding pocket and shows how three different compounds interact with the amino acids in the binding pocket.

[0114] In one embodiment of the first aspect, the inhibitor consists of a central acyclic or cyclic core structure with one to three substituents that are independently directed towards one, two or three of the channels selected from the group of the entry channel, the left channel and the right channel of the tripartite allosteric binding pocket. The phrase "substituents directed towards a channel" is used in the context of the present invention to characterize substituents that protrude into the channel and form a non-covalent bond with at least one amino acid in the channel.

[0115] In a further embodiment of the first aspect, the inhibitor consists of a central heterocyclic or carbocyclic scaffold optionally substituted with one to three substituents that are independently directed into one, two or three of the channels selected from the group consisting of the entry channel, the left channel and the right channel of the tripartite allosteric binding pocket.

[0116] In a further embodiment of the first aspect, the inhibitor consists of a central heteroaromatic scaffold optionally substituted with one to three substituents that are independently directed into one, two or three of the channels selected from the group of the entry channel, the left channel and the right channel of the tripartite allosteric binding pocket.

[0117] In a further embodiment of the first aspect, the inhibitor consists of a central heteroaromatic scaffold optionally substituted with two or three substituents, preferably three substituents, which independently direct one, two or three of the channels selected from the group of the entry channel, the left channel and the right channel of the tripartite allosteric binding pocket.

[0118] In a further embodiment of the first aspect, the inhibitor consists of a central heteroaromatic scaffold consisting of one to three five-, six- or seven-membered rings, where zero to two of the individual rings are selected from five-, six- or seven-membered carbocycles and one to three rings are selected from five-, six- or seven-membered heterocycles, where each ring is annulated to at least one other ring and / or linked via a covalent bond to at least one other ring, and where the heteroaromatic scaffold is optionally substituted with two or three substituents, preferably three, which are independently directed towards one, two or three of the channels selected from the group of the entry channel, the left channel and the right channel of the tripartite allosteric binding pocket.

[0119] In certain embodiments of the first aspect, the 5-, 6- or 7-membered heterocycle is selected from the group consisting of imidazole, imidazoline, pyrazole, pyrazolone, pyrrole, 2-hydroxypyrrole, 1,2,3-triazole, thiophene, 1,2,4-thiadiazole, quinazoline, 1-quinoline, 3-quinoline, pyrrolopyridine, imidazopyridine and pyrimidopyrimidine.

[0120] In certain embodiments of the first or second aspect, the inhibitor of the invention has formula (I): [ka] [During the ceremony, A1 and A3 are each independently selected from N or C; A2 is selected from N, C or O. X is H or OH or NH; L1 is selected from the group consisting of C, CH, CH2, O, N and NH; or L1 is absent; Z is a 5-, 6- or 7-membered carbo- or heterocycle substituted with R3, optionally further substituted, where R3 is linked to Z via a bond or via a -CH2- group; R1 is H or a 5-, 6- or 7-membered carbo- or heterocycle, optionally substituted with 1, 2 or 3 (preferably 1) substituents, independently of one another, selected from the group consisting of -NO2, -CN, -OH, -COOH, -NH-SO2-alkyl (particularly -NH-SO2-(C1-C6)alkyl), NH-CO-alkyl (particularly -NH-CO-(C1-C6)alkyl), -CONH2, -CONH-alkyl (particularly -CONH-(C1-C6)alkyl), -Br, -Cl, -F, -I, -Me, -CF3, -Et, -OMe and -SMe; R2 is H or a 5-, 6- or 7-membered carbon- or heterocycle, optionally substituted with 1, 2 or 3 (preferably 1) lipophilic substituents independently selected from the group consisting of -Br, -Cl, -F, -I, -Me, -CF3, -Et, -OMe and -SMe, where R2 is linked to A3 via a bond or via a -CH2- group; R3 is H or a 5-, 6- or 7-membered carbo- or heterocycle, optionally substituted with 1, 2 or 3 (preferably 1) substituents, each independently of the other, selected from the group consisting of -NO2, -CN, -OH, -COOH, -NH-SO2-alkyl (particularly -NH-SO2-(C1-C6)alkyl), NH-CO-alkyl (particularly -NH-CO-(C1-C6)alkyl), -CONH2, -CONH-alkyl (particularly -CONH-(C1-C6)alkyl), -Br, -Cl, -F, -I, -Me, -CF3, -Et, -OMe and -SMe. or a pharma- ceutically acceptable salt, isomer, solvate, chemically protected form, or prodrug thereof, Here, R1, R2 and R3 preferably have molecular shapes and stereoelectronic properties that are complementary to the allosteric binding pocket.

[0121] In the above formula (I), the "entry channel", "left channel" and "right channel" are shown merely to indicate the relative positions that the inhibitors of the invention occupy when bound to the binding pocket. Showing the positions of the three channels aids one skilled in the art in selecting appropriate substituents from those shown above that can bind to amino acids in the respective shown portions of the binding pocket. Thus, in a further embodiment of the first aspect, R1 is selected to bind to an amino acid in the entry channel, R2 is selected to bind to an amino acid in the left channel, and R3 is selected to bind to an amino acid in the right channel.

[0122] In the above embodiment, the following are preferred: A1 is N substituted with R1.

[0123] In the above embodiment A2 is N.

[0124] In the above embodiment, it is preferred that A3 is C substituted with R2, where R2 is connected to A3 via a bond or via a -CH2- group.

[0125] In the above embodiment, the following are preferred: L1 is CH= or CH2 connected to Z.

[0126] In the above embodiments, the following are preferred: Z is a 5- or 6-membered heterocycle substituted with R3 and optionally further substituted with one or two =O or -NH2, more preferably one or two =O; wherein R3 is connected to Z via a bond or through a -CH2- group and is an optionally further substituted 5-membered heterocycle substituted with R3, wherein R3 is connected to Z via a bond or through a -CH2- group, preferably through a -CH2- group. Particularly preferred 5-membered heteroaryls are selected from the group consisting of optionally further substituted furanyl, thiophenyl, oxazolyl, isoxazolyl, 1,2,3-oxadiazolyl, 1,2,4-oxadiazolyl, pyrrolyl, imidazolyl, pyrazolyl, 1,2,3-triazolyl, 1,2,4-triazolyl, thiazolyl, isothiazolyl, 1,2,3-thiadiazolyl, 1,2,4-thiadiazolyl, where R3 is connected to Z via a bond or via a -CH2- group. The 5-membered heteroaryl may be further substituted with 1 or 2 =O or -NH2, more preferably substituted with 1 or 2 =O. In a further preferred embodiment, Z is a 5-membered N-heteroaryl selected from imidazolyl, pyrrolyl, imidazolyl, pyrazolyl, 1,2,3-triazolyl, 1,2,4-triazolyl, preferably optionally further substituted, preferably with 1 or 2 =0 or -NH2, more preferably with 1 or 2 =0. In a most preferred embodiment, Z is imidazolidine-2,4-dionyl, where R3 is linked to the imidazolidine-2,4-dionyl at the N in the 3-position via a -CH2- group.

[0127] In the above embodiments, the following are preferred: R1 is a 6-membered aryl or a 5- or 6-membered heteroaryl, optionally substituted with one, two or three substituents selected from the group consisting of -NO2, -CN, -OH, -COOH, -NH-SO2-alkyl (particularly -NH-SO2-(C1-C6)alkyl), NH-CO-alkyl (particularly -NH-CO-(C1-C6)alkyl), -CONH2, -CONH-alkyl (particularly -CONH-(C1-C6)alkyl), -Br, -Cl, -F, -I, -Me, -CF3, -Et, -OMe and -SMe. More preferably, R1 is a 6-membered aryl optionally substituted with 1, 2 or 3, preferably 1, substituents independently selected from the group consisting of -NO2, -CN, -OH, -COOH, -NH-SO2-alkyl (particularly -NH-SO2-(C1-C6)alkyl), NH-CO-alkyl (particularly -NH-CO-(C1-C6)alkyl), -CONH2, -CONH-alkyl (particularly -CONH-(C1-C6)alkyl), -Br, -Cl, -F, -I, -Me, -CF3, -Et, -OMe and -SMe.

[0128] In the above embodiments, the following are preferred: R2 is a 6-membered aryl or a 5- or 6-membered heteroaryl, optionally substituted with one, two or three, preferably one lipophilic substituent, independently of one another, selected from the group consisting of -Br, -Cl, -F, -I, Me, -CF3, Et, -OMe and -SMe. More preferably, R2 is a 6-membered aryl, optionally substituted with one, two or three, preferably one lipophilic substituent, independently of one another, selected from the group consisting of -Br, -Cl, -F, -I, Me, -CF3, Et, -OMe and -SMe. If R2 is substituted once, one lipophilic substituent, independently of one another, selected from the group consisting of -Br, -Cl, -F, -I, Me, -CF3, Et, -OMe and -SMe, is in the para position. If R2 is twice substituted, then two lipophilic substituents independently selected from the group consisting of -Br, -Cl, -F, -I, Me, -CF3, Et, -OMe and -SMe are in the ortho and para positions.

[0129] In the above embodiments, the following are preferred: R3 is a 6-membered aryl or a 5- or 6-membered heteroaryl, independently substituted with one, two or three substituents selected from the group consisting of -NO2, -CN, -OH, -COOH, -NH-SO2-alkyl (particularly -NH-SO2-(C1-C6)alkyl), NH-CO-alkyl (particularly -NH-CO-(C1-C6)alkyl), -CONH2, -CONH-alkyl (particularly -CONH-(C1-C6)alkyl), -Br, -Cl, -F, -I, Me, -CF3, Et, -OMe and -SMe. More preferably, R1 is a 6-membered aryl optionally substituted with 1, 2 or 3, preferably 1, substituents independently selected from the group consisting of NO2, -CN, -OH, -COOH, -NH-SO2-alkyl (particularly, -NH-SO2-(C1-C6)alkyl), NH-CO-alkyl (particularly, -NH-CO-(C1-C6)alkyl), -CONH2, -CONH-alkyl (particularly, -CONH-(C1-C6)alkyl), -Br, -Cl, -F, -I, Me, -CF3, Et, -OMe and -SMe.

[0130] In a further embodiment of the first aspect or second aspect of the invention, the inhibitor has the structure of formula (I), wherein: A1 is N substituted with R1; A2 is N; and A3 is C substituted with R2, where R2 is connected to A3 via a bond or via a -CH2- group.

[0131] In the above embodiments, the following are preferred: X is H or OH.

[0132] In the above embodiments, the following are preferred: L1 is CH= or CH2 connected to Z.

[0133] In the above embodiments, the following are preferred: Z is a 5- or 6-membered heterocycle substituted with R3, where R3 is connected to Z through a bond or through a -CH2- group.

[0134] In the above embodiments, the following are preferred: R1 is a 6-membered aryl or a 5- or 6-membered heteroaryl, optionally substituted with one or two or three, preferably one, substituent selected from the group consisting of -NO2, -CN, -OH, -COOH, -NH-SO2-alkyl (particularly -NH-SO2-(C1-C6)alkyl), NH-CO-alkyl (particularly -NH-CO-(C1-C6)alkyl), -CONH2, -CONH-alkyl (particularly -CONH-(C1-C6)alkyl), -Br, -Cl, -F, -I, Me, -CF3, Et, -OMe and -SMe.

[0135] In the above embodiments, the following are preferred: R2 is a 6-membered aryl or a 5- or 6-membered heteroaryl optionally substituted with one, two or three, preferably one, lipophilic substituent selected independently from the group consisting of -Br, -Cl, -F, -I, Me, -CF3, Et, -OMe and -SMe; if R2 is substituted once, one lipophilic substituent selected independently from the group consisting of -Br, -Cl, -F, -I, Me, -CF3, Et, -OMe and -SMe is preferably in the para position; if R2 is substituted twice, two lipophilic substituents selected independently from the group consisting of -Br, -Cl, -F, -I, Me, -CF3, Et, -OMe and -SMe are preferably in the ortho and para positions.

[0136] In the above embodiments, the following are preferred: R3 is a 6-membered aryl or a 5- or 6-membered heteroaryl, optionally substituted with one or two or three, preferably one, substituent selected from the group consisting of -NO2, -CN, -OH, -COOH, -NH-SO2-alkyl (particularly -NH-SO2-(C1-C6)alkyl), NH-CO-alkyl (particularly -NH-CO-(C1-C6)alkyl), -CONH2, -CONH-alkyl (particularly -CONH-(C1-C6)alkyl), -Br, -Cl, -F, -I, Me, -CF3, Et, -OMe and -SMe.

[0137] In the above embodiments, the following are preferred: X is H or OH; and L1 is CH= or CH2 connected to Z.

[0138] In the above embodiments, the following are preferred: X is H or OH; L1 is a CH= or CH2 connected to Z; and Z is a 5- or 6-membered heterocycle substituted with R3, where R3 is linked to Z through a bond or through a -CH2- group.

[0139] In the above embodiments, the following are preferred: X is H or OH; L1 is a CH= or CH2 connected to Z; and R1 is a 6-membered aryl or a 5- or 6-membered heteroaryl, preferably a 6-membered aryl or heteroaryl, more preferably a 6-membered aryl, optionally substituted with 1, 2 or 3 (preferably 1) substituents independently of one another selected from the group consisting of -NO2, -CN, -OH, -COOH, -NH-SO2-alkyl (particularly -NH-SO2-(C1-C6)alkyl), NH-CO-alkyl (particularly -NH-CO-(C1-C6)alkyl), -CONH2, -CONH-alkyl (particularly -CONH-(C1-C6)alkyl), -Br, -Cl, -F, -I, Me, -CF3, Et, -OMe and -SMe.

[0140] In the above embodiments, the following are preferred: X is H or OH; L1 is a CH= or CH2 connected to Z; and R2 is a 6-membered aryl or a 5- or 6-membered heteroaryl, preferably a 6-membered aryl or heteroaryl, more preferably a 6-membered aryl, optionally substituted with 1, 2 or 3, preferably 1, lipophilic substituents independently selected from the group consisting of -Br, -Cl, -F, -I, Me, -CF3, Et, -OMe and -SMe. If R2 is substituted once, one lipophilic substituent independently selected from the group consisting of -Br, -Cl, -F, -I, Me, -CF3, Et, -OMe and -SMe is preferably in the para position, and if R2 is substituted twice, two lipophilic substituents independently selected from the group consisting of -Br, -Cl, -F, -I, Me, -CF3, Et, -OMe and -SMe are preferably in the ortho and para positions.

[0141] In the above embodiments, the following are preferred: X is H or OH; L1 is a CH= or CH2 connected to Z; and R3 is a 6-membered aryl or a 5- or 6-membered heteroaryl, preferably a 6-membered aryl or heteroaryl, more preferably a 6-membered aryl, optionally substituted with 1, 2 or 3 (preferably 1) substituents, independently of one another, selected from the group consisting of -NO2, -CN, -OH, -COOH, -NH-SO2-alkyl (particularly -NH-SO2-(C1-C6)alkyl), NH-CO-alkyl (particularly -NH-CO-(C1-C6)alkyl), -CONH2, -CONH-alkyl (particularly -CONH-(C1-C6)alkyl), -Br, -Cl, -F, -I, Me, -CF3, Et, -OMe and -SMe.

[0142] In the above embodiments, the following are preferred: X is H or OH; L1 is CH= or CH2 connected to Z; Z is a 5- or 6-membered heterocycle substituted with R3, where R3 is linked to Z through a bond or through a -CH2- group; and R1 is a 6-membered aryl or a 5- or 6-membered heteroaryl, preferably a 6-membered aryl or heteroaryl, more preferably a 6-membered aryl, optionally substituted with 1, 2 or 3 (preferably 1) substituents selected from the group consisting of 1, 2 or 3 (preferably 1) independently selected from the group consisting of -NO2, -CN, -OH, -COOH, -NH-SO2-alkyl (particularly -NH-SO2-(C1-C6)alkyl), NH-CO-alkyl (particularly -NH-CO-(C1-C6)alkyl), -CONH2, -CONH-alkyl (particularly -CONH-(C1-C6)alkyl), -Br, -Cl, -F, -I, Me, -CF3, Et, -OMe and -SMe;

[0143] In the above embodiments, the following are preferred: X is H or OH; L1 is CH= or CH2 connected to Z; Z is a 5- or 6-membered heterocycle substituted with R3, where R3 is linked to Z through a bond or through a -CH2- group; and R2 is a 6-membered aryl or a 5- or 6-membered heteroaryl, preferably a 6-membered aryl or heteroaryl, more preferably a 6-membered aryl, optionally substituted with one, two or three (preferably one) lipophilic substituents, independently of one another, selected from the group consisting of -Br, -Cl, -F, -I, Me, -CF3, Et, -OMe and -SMe, if R2 is substituted once, one lipophilic substituent, independently of one another, selected from the group consisting of -Br, -Cl, -F, -I, Me, -CF3, Et, -OMe and -SMe, is preferably in the para position, and if R2 is substituted twice, two lipophilic substituents, independently of one another, selected from the group consisting of -Br, -Cl, -F, -I, Me, -CF3, Et, -OMe and -SMe, are preferably in the ortho and para positions; and

[0144] In the above embodiments, the following are preferred: X is H or OH; L1 is CH= or CH2 connected to Z; Z is a 5- or 6-membered heterocycle substituted with R3, where R3 is linked to Z through a bond or through a -CH2- group; and R3 is a 6-membered aryl or a 5- or 6-membered heteroaryl, preferably a 6-membered aryl or heteroaryl, more preferably a 6-membered aryl, optionally substituted with 1, 2 or 3 (preferably 1) substituents independently selected from the group consisting of -NO2, -CN, -OH, -COOH, -NH-SO2-alkyl (particularly -NH-SO2-(C1-C6)alkyl), NH-CO-alkyl (particularly -NH-CO-(C1-C6)alkyl), -CONH2, -CONH-alkyl (particularly -CONH-(C1-C6)alkyl), -Br, -Cl, -F, -I, Me, -CF3, Et, -OMe and -SMe.

[0145] In the above embodiments, the following are preferred: A1 is N substituted with R1; A2 is N; A3 is C substituted with R2, where R2 is connected to A3 via a bond or via a -CH2- group; X is H or OH; L1 is CH2 connected to CH= or Z; Z is a 5- or 6-membered heterocycle substituted with R3, where R3 is linked to Z via a bond or via a -CH2- group; R1 is a 6-membered aryl or a 5- or 6-membered heteroaryl, preferably a 6-membered aryl or heteroaryl, more preferably a 6-membered aryl, independently substituted with one or two or three (preferably one) substituents selected from the group consisting of -NO2, -CN, -OH, -COOH, -NH-SO2-alkyl (particularly -NH-SO2-(C1-C6)alkyl), NH-CO-alkyl (particularly -NH-CO-(C1-C6)alkyl), -CONH2, -CONH-alkyl (particularly -CONH-(C1-C6)alkyl), -Br, -Cl, -F, -I, -Me, -CF3, -Et, -OMe and -SMe; R2 is a 6-membered aryl or a 5- or 6-membered heteroaryl, preferably a 6-membered aryl or heteroaryl, more preferably a 6-membered aryl, optionally substituted with one, two or three (preferably one) lipophilic substituents independently selected from the group consisting of -Br, -Cl, -F, -I, Me, -CF3, Et, -OMe and -SMe; if R2 is substituted once, one lipophilic substituent independently selected from the group consisting of -Br, -Cl, -F, -I, Me, -CF3, Et, -OMe and -SMe is preferably in the para position, and if R2 is substituted twice, two lipophilic substituents independently selected from the group consisting of -Br, -Cl, -F, -I, Me, -CF3, Et, -OMe and -SMe are preferably in the ortho and para positions; and R3 is a 6-membered aryl or a 5- or 6-membered heteroaryl, preferably a 6-membered aryl or heteroaryl, more preferably a 6-membered aryl, independently substituted with one or two or three (preferably one) substituents selected from the group consisting of -NO2, -CN, -OH, -COOH, -NH-SO2-alkyl (particularly -NH-SO2-(C1-C6)alkyl), NH-CO-alkyl (particularly -NH-CO-(C1-C6)alkyl), -CONH2, -CONH-alkyl (particularly -CONH-(C1-C6)alkyl), -Br, -Cl, -F, -I, Me, -CF3, Et, -OMe and -SMe.

[0146] In the above embodiments, the following are preferred: A1 is N substituted with R1; A2 is N; A3 is C substituted with R2, where R2 is connected to A3 via a bond or via a -CH2- group; X is H or OH; L1 is CH2 connected to CH= or Z; Z is a 5-membered heterocycle substituted with R3, where R3 is linked to Z through a bond or through a -CH2- group; R1 is a 6-membered aryl or heteroaryl, preferably a 6-membered aryl, independently of each other, substituted by one or two, preferably one, substituents selected from the group consisting of -NO2, -CN, -OH, -COOH, -NH-SO2-alkyl (particularly -NH-SO2-(C1-C6)alkyl), NH-CO-alkyl (particularly -NH-CO-(C1-C6)alkyl), -CONH2, -CONH-alkyl (particularly -CONH-(C1-C6)alkyl), -Br, -Cl, -F, -I, Me, -CF3, Et, -OMe and -SMe; R2 is a 6-membered aryl or heteroaryl, preferably a 6-membered aryl, optionally substituted with one or two lipophilic substituents, independently of one another, selected from the group consisting of -Br, -Cl, -F, -I, Me, -CF3, Et, -OMe and -SMe, if R2 is substituted once, then one lipophilic substituent, independently of one another, selected from the group consisting of -Br, -Cl, -F, -I, Me, -CF3, Et, -OMe and -SMe, is preferably in the para position, and if R2 is substituted twice, then two lipophilic substituents, independently of one another, selected from the group consisting of -Cl, -F, -I, Me, -CF3, Et, -OMe and -SMe, are preferably in the para position; and R3 is a 6-membered aryl or heteroaryl, preferably a 6-membered aryl, optionally substituted with one or two (preferably one) substituents independently selected from the group consisting of -NO2, -CN, -OH, -COOH, -NH-SO2-alkyl (particularly -NH-SO2-(C1-C6)alkyl), NH-CO-alkyl (particularly -NH-CO-(C1-C6)alkyl), -CONH2, -CONH-alkyl (particularly -CONH-(C1-C6)alkyl), -Br, -Cl, -F, -I, Me, -CF3, Et, -OMe and -SMe.

[0147] In a further embodiment of the first or second aspect of the invention, the inhibitor has the structure of formula (I), wherein A1 is N substituted with R1; A2 is N; and A3 is C substituted with R2, where R2 is linked to A3 via a bond or via a -CH2- group.

[0148] In the above embodiments, the following are preferred: X is H or OH.

[0149] In the above embodiments, the following are preferred: L1 is CH= connected to Z.

[0150] In the above embodiment, the following are preferred: Z is a 5-membered heterocycle, preferably a 5-membered heteroaryl, more preferably a 5-membered N-heteroaryl, substituted with R3, where R3 is linked to Z via a bond or via a -CH2- group, preferably via a -CH2- group.

[0151] In the above embodiments, the following are preferred: R1 is a 6-membered aryl or a 5- or 6-membered heteroaryl, preferably a 6-membered aryl or heteroaryl, more preferably a 6-membered aryl, optionally substituted with one or two or three, preferably one, substituents selected from the group consisting of -NO2, -CN, -OH, COOH, NH-SO2-alkyl (particularly -NH-SO2-(C1-C6)alkyl), NH-CO-alkyl (particularly -NH-CO-(C1-C6)alkyl), -CONH2, -CONH-alkyl (particularly -CONH-(C1-C6)alkyl), -Br, -Cl, -F, -I, Me, -CF3, Et, -OMe and -SMe.

[0152] In the above embodiments, the following are preferred: R2 is a 6-membered aryl or a 5- or 6-membered heteroaryl, preferably a 6-membered aryl or heteroaryl, more preferably a 6-membered aryl, optionally substituted with one, two or three, preferably one, lipophilic substituent selected from the group consisting of -Br, -Cl, -F, -I, Me, -CF3, Et, -OMe and -SMe; if R2 is substituted once, then one lipophilic substituent, independent of each other, selected from the group consisting of -Br, -Cl, -F, -I, Me, -CF3, Et, -OMe and -SMe, is preferably in the para position; if R2 is substituted twice, then two lipophilic substituents, independent of each other, selected from the group consisting of -Br, -Cl, -F, -I, Me, -CF3, Et, -OMe and -SMe, are preferably in the ortho and para positions.

[0153] In the above embodiments, the following are preferred: R3 is a 6-membered aryl or a 5- or 6-membered heteroaryl, preferably a 6-membered aryl or heteroaryl, more preferably a 6-membered aryl, optionally substituted with one or two or three, preferably one, substituents independently selected from the group consisting of -NO2, -CN, -OH, -COOH, -NH-SO2-alkyl (particularly -NH-SO2-(C1-C6)alkyl), NH-CO-alkyl (particularly -NH-CO-(C1-C6)alkyl), -CONH2, -CONH-alkyl (particularly -CONH-(C1-C6)alkyl), -Br, -Cl, -F, -I, Me, -CF3, Et, -OMe and -SMe, wherein R3 is linked to Z via a -CH2- group.

[0154] In the above embodiments, the following are preferred: X is H or OH; and L1 is CH= connected to Z.

[0155] In the above embodiments, the following are preferred: X is H or OH; L1 is CH= connected to Z; and Z is a 5-membered heterocycle, preferably a 5-membered N-heterocycle, substituted with R3, where R3 is linked to Z via a bond or via a -CH2- group, preferably via a -CH2- group.

[0156] In the above embodiments, the following are preferred: X is H or OH; L1 is CH= connected to Z; Z is a 5-membered heterocycle substituted with R3, where R3 is linked to Z through a bond or through a -CH2- group; and R1 is a 6-membered aryl or a 5- or 6-membered heteroaryl, preferably a 6-membered aryl or heteroaryl, more preferably a 6-membered aryl, optionally substituted with 1 or 2 or 3, preferably 1, substituents selected from the group consisting of -NO2, -CN, -OH, COOH, NH-SO2-alkyl (particularly -NH-SO2-(C1-C6)alkyl), NH-CO-alkyl (particularly -NH-CO-(C1-C6)alkyl), -CONH2, -CONH-alkyl (particularly -CONH-(C1-C6)alkyl), -Br, -Cl, -F, -I, Me, -CF3, Et, -OMe and -SMe;

[0157] In the above embodiments, the following are preferred: X is H or OH; L1 is CH= connected to Z; Z is a 5-membered heterocycle, preferably a 5-membered N-heterocycle, substituted with R3, where R3 is connected to Z via a bond or via a -CH2- group; and R2 is a 6-membered aryl or a 5- or 6-membered heteroaryl, preferably a 6-membered aryl or heteroaryl, more preferably a 6-membered aryl, substituted with 1, 2 or 3, preferably 1, lipophilic substituents independently selected from the group consisting of -Br, -Cl, -F, -I, Me, -CF3, Et, -OMe and -SMe, if R2 is substituted once, then one lipophilic substituent independently selected from the group consisting of -Br, -Cl, -F, -I, Me, -CF3, Et, -OMe and -SMe is preferably in the para position, and if R2 is substituted twice, then two lipophilic substituents independently selected from the group consisting of -Br, -Cl, -F, -I, Me, -CF3, Et, -OMe and -SMe are preferably in the ortho and para positions; and

[0158] In the above embodiments, the following are preferred: X is H or OH; L1 is CH= connected to Z; Z is a 5-membered heterocycle, preferably a 5-membered N-heterocycle, substituted with R3, where R3 is connected to Z via a bond or via a -CH2- group; and R3 is a 6-membered aryl or a 5- or 6-membered heteroaryl, preferably a 6-membered aryl or heteroaryl, more preferably a 6-membered aryl, optionally substituted with 1, 2 or 3, preferably 1, substituents independently selected from the group consisting of -NO2, -CN, -OH, -COOH, -NH-SO2-alkyl (particularly -NH-SO2-(C1-C6)alkyl), NH-CO-alkyl (particularly -NH-CO-(C1-C6)alkyl), -CONH2, -CONH-alkyl (particularly -CONH-(C1-C6)alkyl), -Br, -Cl, -F, -I, Me, -CF3, Et, -OMe and -SMe, wherein R3 is connected to Z via the R3-CH2- group.

[0159] In the above embodiments, the following are preferred: A1 is N substituted with R1; A2 is N; A3 is C substituted with R2, where R2 is connected to A3 via a bond or via a -CH2- group; X is H or OH; L1 is CH= connected to Z; Z is a 5-membered heterocycle, preferably a 5-membered N-heterocycle, substituted with R3, where R3 is connected to Z via a bond or a -CH2- group, preferably a -CH2- group; R1 is a 6-membered aryl or a 5- or 6-membered heteroaryl, preferably a 6-membered aryl or heteroaryl, more preferably a 6-membered aryl, optionally substituted with 1, 2 or 3, preferably 1, substituents independently selected from the group consisting of -NO2, -CN, -OH, COOH, NH-SO2-alkyl (especially -NH-SO2-(C1-C6)alkyl), NH-CO-alkyl (especially -NH-CO-(C1-C6)alkyl), -CONH2, -CONH-alkyl (especially -CONH-(C1-C6)alkyl), -Br, -Cl, -F, -I, Me, -CF3, Et, -OMe and -SMe; R2 is a 6-membered aryl or a 5- or 6-membered heteroaryl, preferably a 6-membered aryl or heteroaryl, more preferably a 6-membered aryl, optionally substituted with 1 or 2 or 3, preferably 1, lipophilic substituents selected from the group consisting of -Br, -Cl, -F, -I, Me, -CF3, Et, -OMe and -SMe, if R2 is substituted once, one lipophilic substituent independently selected from the group consisting of -Br, -Cl, -F, -I, Me, -CF3, Et, -OMe and -SMe is preferably in the para position, and if R2 is substituted twice, two lipophilic substituents independently selected from the group consisting of -Br, -Cl, -F, -I, Me, -CF3, Et, -OMe and -SMe are preferably in the ortho and para positions; and R3 is a 6-membered aryl or a 5- or 6-membered heteroaryl, preferably a 6-membered aryl or heteroaryl, more preferably a 6-membered aryl, optionally substituted with 1, 2 or 3, preferably 1, substituents independently selected from the group consisting of -NO2, -CN, -OH, -COOH, -NH-SO2-alkyl (particularly -NH-SO2-(C1-C6)alkyl), NH-CO-alkyl (particularly -NH-CO-(C1-C6)alkyl), -CONH2, -CONH-alkyl (particularly -CONH-(C1-C6)alkyl), -Br, -Cl, -F, -I, Me, -CF3, Et, -OMe and -SMe, wherein R3 is connected to Z via the R3-CH2- group.

[0160] In the above embodiments, the following are preferred: A1 is N substituted with R1; A2 is N; A3 is C substituted with R2, where R2 is connected to A3 via a bond or via a -CH2- group; X is H or OH; L1 is CH= connected to Z; Z is a 5-membered heterocycle substituted with R3, where R3 is connected to Z via a bond or a -CH2- group, preferably a -CH2- group; R1 is a 6-membered aryl or heteroaryl, more preferably a 6-membered aryl, optionally substituted with 1, 2 or 3, preferably 1, substituents independently selected from the group consisting of -NO2, -CN, -OH, COOH, NH-SO2-alkyl (especially -NH-SO2-(C1-C6)alkyl), NH-CO-alkyl (especially -NH-CO-(C1-C6)alkyl), -CONH2, -CONH-alkyl (especially -CONH-(C1-C6)alkyl), -Br, -Cl, -F, -I, Me, -CF3, Et, -OMe and -SMe; R2 is a 6-membered aryl or heteroaryl, more preferably a 6-membered aryl, optionally substituted with 1 or 2 or 3, preferably 1, lipophilic substituents selected from the group consisting of -Br, -Cl, -F, -I, Me, -CF3, Et, -OMe and -SMe, if R2 is substituted once, one lipophilic substituent independently selected from the group consisting of -Br, -Cl, -F, -I, Me, -CF3, Et, -OMe and -SMe is preferably in the para position, and if R2 is substituted twice, two lipophilic substituents independently selected from the group consisting of -Br, -Cl, -F, -I, Me, -CF3, Et, -OMe and -SMe are preferably in the ortho and para positions; and R3 is a 6-membered aryl or heteroaryl, more preferably a 6-membered aryl, optionally substituted with 1, 2 or 3, preferably 1, substituents independently selected from the group consisting of -NO2, -CN, -OH, -COOH, -NH-SO2-alkyl (especially -NH-SO2-(C1-C6)alkyl), NH-CO-alkyl (especially -NH-CO-(C1-C6)alkyl), -CONH2, -CONH-alkyl (especially -CONH-(C1-C6)alkyl), -Br, -Cl, -F, -I, Me, -CF3, Et, -OMe and -SMe, wherein R3 is connected to Z via the R3-CH2- group.

[0161] In a further embodiment of the first aspect or second aspect of the invention, the inhibitor has the structure of formula (I), wherein: A1 is N substituted with R1; A2 is N; A3 is C substituted with R2, where R2 is connected to A3 via a bond or via a -CH2- group; X is OH; L1 is CH= connected to Z; Z is a 5-membered heterocycle substituted with R3, where R3 is connected to Z through a bond or through a -CH2- group; R1 is a 6-membered aryl or a 5- or 6-membered heteroaryl, preferably a 6-membered aryl or heteroaryl, more preferably a 6-membered aryl, optionally substituted with 1 or 2 or 3 polar substituents independently selected from the group consisting of -NO2, -CN, -OH, COOH, NH-SO2-alkyl (especially -NH-SO2-(C1-C6)alkyl), NH-CO-alkyl (especially -NH-CO-(C1-C6)alkyl), -CONH2 and -CONH-alkyl (especially -CONH-(C1-C6)alkyl); R2 is a 6-membered aryl or a 5- or 6-membered heteroaryl, preferably a 6-membered aryl or heteroaryl, more preferably a 6-membered aryl, optionally substituted with 1, 2 or 3, preferably 1, lipophilic substituents independently selected from the group consisting of -Br, -Cl, -F, -I, Me, -CF3, Et, -OMe and -SMe, if R2 is substituted once, one lipophilic substituent independently selected from the group consisting of -Br, -Cl, -F, -I, Me, -CF3, Et, -OMe and -SMe is preferably in the para position, if R2 is substituted twice, two lipophilic substituents independently selected from the group consisting of -Br, -Cl, -F, -I, Me, -CF3, Et, -OMe and -SMe are preferably in the ortho and para positions; R3 is a 6-membered aryl or a 5- or 6-membered heteroaryl, preferably a 6-membered aryl or heteroaryl, more preferably a 6-membered aryl, optionally substituted with 1, 2 or 3, preferably 1, lipophilic substituents independently selected from the group consisting of -Br, -Cl, -F, -I, Me, -CF3, Et, -OMe and -SMe.

[0162] In a further embodiment of the first aspect or second aspect of the invention, the inhibitor has the structure of formula (I), wherein: A1 is N substituted with R1; A2 is N; A3 is C substituted with R2, where R2 is connected to A3 via a bond or via a -CH2- group; X is OH; L1 is CH= connected to Z; Z is an imidazolidine-2,4-dione, where R is linked to Z via a -CH- group at the 3-position of the imidazolidine-2,4-dione; R1 is a 6-membered aryl or heteroaryl, preferably a 6-membered aryl, optionally substituted with 1 or 2 or 3 polar substituents independently selected from the group consisting of -NO2, -CN, -OH, COOH, NH-SO2-alkyl (especially -NH-SO2-(C1-C6)alkyl), NH-CO-alkyl (especially -NH-CO-(C1-C6)alkyl), -CONH2 and -CONH-alkyl (especially -CONH-(C1-C6)alkyl); R2 is a 6-membered aryl or heteroaryl, preferably a 6-membered aryl, optionally substituted with 1, 2 or 3, preferably 1, lipophilic substituents independently selected from the group consisting of -Br, -Cl, -F, -I, Me, -CF3, Et, -OMe and -SMe, if R2 is substituted once, then one lipophilic substituent independently selected from the group consisting of -Br, -Cl, -F, -I, Me, -CF3, Et, -OMe and -SMe is preferably in the para position, if R2 is substituted twice, then two lipophilic substituents independently selected from the group consisting of -Br, -Cl, -F, -I, Me, -CF3, Et, -OMe and -SMe are preferably in the ortho and para positions; R3 is a 6-membered aryl or heteroaryl, preferably a 6-membered aryl, optionally substituted with 1, 2 or 3, preferably 1, lipophilic substituents independently selected from the group consisting of -Br, -Cl, -F, -I, Me, -CF3, Et, -OMe and -SMe.

[0163] In a further embodiment of the first aspect or second aspect of the invention, the inhibitor has the structure of formula (I), wherein: A1 is N substituted with R1; A2 is N; A3 is C substituted with R2, where R2 is connected to A3 via a bond or via a -CH2- group; X is OH; L1 is CH= connected to Z; Z is an imidazolidine-2,4-dione, where R is linked to Z via a -CH- group at the N at position 3 of the imidazolidine-2,4-dione; R1 is phenyl optionally substituted with one, two or three, preferably one polar moiety independently selected from the group consisting of -NO2, -CN, -OH, COOH, NH-SO2-alkyl (particularly -NH-SO2-(C1-C6)alkyl), NH-CO-alkyl (particularly -NH-CO-(C1-C6)alkyl), -CONH2 and -CONH-alkyl (particularly -CONH-(C1-C6)alkyl); R2 is any phenyl or benzyl (preferably phenyl) substituted with one, two or three (preferably one) lipophilic substituents independently selected from the group consisting of -Br, -Cl, -F, -I, Me, -CF3, Et, -OMe and -SMe, if R2 is substituted once, one lipophilic substituent independently selected from the group consisting of -Br, -Cl, -F, -I, Me, -CF3, Et, -OMe and -SMe is preferably in the para position, if R2 is substituted twice, two lipophilic substituents independently selected from the group consisting of -Br, -Cl, -F, -I, Me, -CF3, Et, -OMe and -SMe are preferably in the ortho and para positions; R3 is phenyl substituted with one, two or three (preferably one) lipophilic substituents selected, independently from each other, from the group consisting of -Br, -Cl, -F, -I, Me, -CF3, Et, -OMe and -SMe.

[0164] In a further embodiment of the first or second aspect of the invention, the inhibitor has the structure of formula (I), wherein A1 is N substituted with R1 A2 is N A3 is C substituted with R2, where R2 is linked to A3 via a bond or via a -CH2- group; X is OH; L1 is CH= bonded to Z; Z is an imidazolidine-2,4-dione, where R is linked to Z via a -CH- group at the N at the 3-position of the imidazolidine-2,4-dione; R1 is phenyl, 4-nitrophenyl, 2,6-dichloro-4-bromophenyl, 4-fluorophenyl, 4-bromophenyl, 2,6-dichlorophenyl, 2-methylphenyl, 4-methylphenyl, 2,3-dimethylphenyl or 4-methoxyphenyl; R2 is 2,4-dichlorophenyl, 4-chlorophenyl, phenyl, benzyl, 3-pyridine, 2-methylbenzyl, 4-fluorobenzyl, 4-chlorobenzyl, 2-methoxyphenyl or 3-methoxyphenyl; and R3 is 4-fluorophenyl, 2-fluorophenyl, 3-fluorophenyl, 2,4-difluorophenyl, 2-methylphenyl, 3-methylphenyl, 4-methylphenyl, 2-chlorophenyl, 3-chlorophenyl, 3-pyridine, 3-methoxyphenyl, 4-nitrophenyl, 3-nitrophenyl, 4-trifluoromethyl-phenyl or 4-cyanophenyl.

[0165] In further particular embodiments of the first or second aspect of the invention, the inhibitor has formula (II): [ka] [During the ceremony, A5 and A8 are each independently selected from N or CH; A6 is selected from N or CH or, if A6 participates in an annulated carbo- or heterocycle Z, A6 is C; A7 is selected from N or CH or, if A7 participates in an annulated carbo- or heterocycle Z, A7 is C; L2 is selected from the group consisting of -CH2-R4, -CF2-R4, -CH2-CH2-R4, -CH2-CH2-CH2-R4, -O-R4, -NH-R4, -N=R4; L3 is selected from the group consisting of CH2-R5, -CF2-R5, -CH2-CH2-R5, -CH2-COH2-R5, -CH=CH-R5, -CH2-CF2-R5, -CH2-CH2-CH2-R5, -O-R5, -NH-R5, -N=R5; or L2 and L3 together with A8 to which they are attached form a 5- or 6-membered heterocycle substituted with R4 and / or R5; L4 is CH2, -CF2-, CH2-CH2, CH2-CH2-CH2, O, N, NH or absent; Z is a 5-, 6- or 7-membered carbo- or heterocycle optionally substituted with 1, 2 or 3, preferably 1, substituents selected from the group consisting of -Br, -Cl, -F, -I, -OH, Me, -CF3, Et, -OMe, -SMe and -NO2; and may be cyclized or linked via covalent bonds to a central core; R4 is a 5-, 6- or 7-membered carbo- or heterocycle optionally substituted with 1, 2 or 3, preferably 1, lipophilic substituent selected from the group consisting of -Br, -Cl, -F, -I, -CF3, Me, Et, -OMe and -SMe, or R4 is hydrogen, methyl or COOH; R5 is a 5-, 6-, 7-, 8-, 9- or 10-membered carbo- or heterocycle optionally substituted with 1, 2 or 3 (preferably 1) lipophilic substituents selected from the group consisting of -Br, -Cl, -F, -I, Me, -CF3, Et, -OMe and -SMe; R6 is a 5-, 6- or 7-membered carbo- or heterocycle optionally substituted with 1, 2 or 3 (preferably 1) substituents selected from the group consisting of -Br, -Cl, -F, -I, -OH, -NO2, Me, -CF3, Et, -OMe and -SMe; Or R6 is H; or When A7 occupies a part of the cyclized carbocycle or heterocycle Z, A5 and A6 are independently selected from -N or -CH, and A8 is selected from -N, -CH, -CH2-N, -CH2-CH or -NH-CH. or a pharma- ceutically acceptable salt, isomer, solvate, chemically protected form, or prodrug thereof, Here, R4, R5 and R6 preferably have molecular shapes and stereoelectronic properties complementary to the allosteric binding pocket.

[0166] The above definitions of the linkers L2 and L3 in the context of formula (II) include R4 and R5, respectively. Reference to the substituents R4 and R5 in the linker definition means that R4 and R5 occur twice in the resulting compound of formula (II). do not R4 and R5 are further listed in the definitions of L2 and L3 to clarify the orientation of the linkers A8 to R4 or A8 to R5, respectively.

[0167] In the above formula (II), the "entry channel" and the "right channel" are shown merely to indicate the relative positions that the inhibitors of the present invention occupy when bound to the binding pocket. Showing the positions of the three channels helps one skilled in the art to select appropriate substituents from those shown above that may bind to amino acids in the respective shown portions of the binding pocket. Thus, in a further embodiment of the first aspect, R4 and R5 are selected to bind to amino acids in the entry channel and R6 is selected to bind to an amino acid in the right channel.

[0168] In the above embodiments, the following are preferred: A5 and A6 are N; and A7 participates in an annulated carbo- or heterocycle, preferably the carbocycle Z.

[0169] In the above embodiments, the following are preferred: A5 and A6 are N; A7 involves an annulated carbo- or heterocycle, preferably the carbocycle Z; and A8 is -CH2-N, -CH2-CH or -NH-CH, preferably -NH-CH.

[0170] In the above embodiments, the following are preferred: A5 is N and A8 is --N or --CH.

[0171] In the above embodiments, the following are preferred: A5 is N and A8 is -N or -CH; and A6 participates in an annulated carbocycle or heterocycle, preferably the Z carbocycle.

[0172] In the above embodiments, the following are preferred: L2 is selected from the group consisting of -CH2-R4, -CH2-CH2-R4, and -CH2-CH2-CH2-R4.

[0173] In the above embodiment, it is preferred that: L2 is selected from the group consisting of -CH2-R4, -CF2-R4, -CH2-CH2-R4, -CH2-CH2-CH2-R4, -NH-R4; and R4 is a 6-membered aryl or a 5-, 6- or 7-membered heteroaryl, preferably a 5- or 6-membered heteroaryl, optionally substituted with 1, 2 or 3, preferably 1, lipophilic substituents selected from the group consisting of -Br, -Cl, -F, -I, -CF3, Me, Et, -OMe and -SMe, or R4 is hydrogen, methyl or COOH.

[0174] In the above embodiments, the following are preferred: L3 is selected from the group consisting of -CH2-R5, -CH2-CH2-R5, -CH2-CF2-R5;

[0175] In the above embodiment, the following are preferred: L3 is selected from the group consisting of -CH2-R5, -CH2-CH2-R5, -CH2-CF2-R5; and R5 is a 5-, 6-, 7-, 8-, 9- or 10-membered carbon- or heterocycle optionally substituted with one, two or three (preferably one) lipophilic substituents selected from the group consisting of -Br, -Cl, -F, -I, Me, -CF3, Et, -OMe and -SMe.

[0176] In the above embodiments, the following are preferred: L2 and L3 together with A8 to which they are attached form a 5- or 6-membered heterocycle substituted by R4 and R5.

[0177] In the above embodiments, the following are preferred: L2 and L3 together with A8 to which they are attached form a 5- or 6-membered heterocycle substituted by R4 and R5; R4 is hydrogen, methyl or COOH; R5 is a 5-, 6-, or 7-membered carbocycle or heterocycle, preferably phenyl or a 5- or 6-membered heteroaryl, optionally substituted with 1, 2 or 3, preferably 1, lipophilic substituent selected from the group consisting of -Br, -Cl, -F, -I, Me, -CF3, Et, -OMe and -SMe.

[0178] In the above embodiments, the following are preferred: L4 does not exist.

[0179] In the above embodiments, the following are preferred: R4 is hydrogen, methyl, COOH or tetrazolyl.

[0180] In the above embodiments, the following are preferred: L2 is -CH2-R4, -CH2-CH2-R4, -CH2-CH2-CH2-R4; and R4 is hydrogen, methyl, COOH or tetrazolyl.

[0181] In the above embodiments, the following are preferred: R5 is any 5-, 6-, 7-, 8-, 9- or 10-membered carbon- or heterocycle optionally substituted with one, two or three, preferably one, lipophilic substituent selected from the group consisting of -Br, -Cl, -F, -I, -CF3, Me, Et, -OMe and -SMe.

[0182] In the above embodiments, the following are preferred: R5 is C5-C7-cycloalkyl, i.e. C5-, C6- or C7-cycloalkyl, C6-C ... 10 -bicycloalkyl, i.e. C6-, C7-, C8-, C9- or C 10 -Bicycloalkyl, C6-C 10 -spiroalkyl, i.e. C6-, C7-, C8-, C9- or C 10 -spiroalkyl, phenyl, 5- or 6-membered heteroaryl, adamantyl; more preferably cyclopentyl, cyclohexyl, phenyl, bromo-phenyl, bicyclo[2.2.1]heptyl, spiro[3,3]heptyl or adamantyl, optionally substituted with 1, 2 or 3, preferably 1, lipophilic substituents selected from the group consisting of -Br, -Cl, -F, -I, Me, -CF3, Et, -OMe and -SMe, more preferably unsubstituted phenyl or adamantyl substituted with 1 or 2 lipophilic substituents selected from the group consisting of -Br, -Cl, -F, -I, Me, -CF3, Et, -OMe and -SMe;

[0183] In the above embodiments, the following are preferred: L3 is selected from the group consisting of -CH2-R5, -CH2-CH2-R5, -CH2-CF2-R5; and R5 is optionally substituted with one, two or three, preferably one, lipophilic substituent selected from the group consisting of -Br, -Cl, -F, -I, Me, -CF3, Et, -OMe and -SMe, and is C5-C7-cycloalkyl, i.e. C5-, C6- or C7-cycloalkyl, C6-C 10 -bicycloalkyl, i.e. C6-, C7-, C8-, C9- or C 10 -Bicycloalkyl, C6-C 10 -spiroalkyl, i.e. C6-, C7-, C8-, C9- or C 10 -spiroalkyl, phenyl, 5- or 6-membered heteroaryl, adamantyl; more preferably cyclopentyl, cyclohexyl, phenyl, bromo-phenyl, bicyclo[2.2.1]heptyl, spiro[3,3]heptyl or adamantyl, optionally substituted with 1, 2 or 3, preferably 1, lipophilic substituents selected from the group consisting of -Br, -Cl, -F, -I, Me, -CF3, Et, -OMe and -SMe, more preferably unsubstituted phenyl or adamantyl substituted with 1 or 2 lipophilic substituents selected from the group consisting of -Br, -Cl, -F, -I, Me, -CF3, Et, -OMe and -SMe;

[0184] In the above embodiments, the following are preferred: R6 is a 6-membered aryl or a 5-, 6- or 7-membered heteroaryl optionally substituted with 1, 2 or 3, preferably 1, substituent selected from the group consisting of -Br, -Cl, -F, -I, -OH, -NO2, Me, -CF3, Et, -OMe and -SMe; Or R6 is H.

[0185] In the above embodiments, the following are preferred: L4 is absent; and R6 is a 5- or 6-membered carbo- or heterocycle, preferably a 6-membered carbo- or heterocycle, optionally substituted with 1, 2 or 3 (preferably 1) substituents selected from the group consisting of -Br, -Cl, -F, -I, -OH, -NO2, Me, -CF3, Et, -OMe and -SMe.

[0186] In the above embodiments, the following are preferred: Z is a 6-membered aryl or a 5-, 6-membered heteroaryl, preferably phenyl, optionally substituted with 1, 2 or 3, preferably 1, substituents selected from the group consisting of -Br, -Cl, -F, -I, -OH, Me, -CF3, Et, -OMe, -SMe and -NO2.

[0187] In a further embodiment of the first or second aspect of the invention, the inhibitor has a structure of formula (II), wherein A5 is N one of A6 and A7 is CH and the other is N; or one of A6 and A7 is C and occupies part of an annulated carbo- or heterocycle Z, and the other is N; A8 is N or CH; L2, L3, L4 are each independently selected from the group consisting of CH2, -CF2-, CH2-CH2, CH2-CH2-CH2, O, N and NH, or are absent, or L2 and L3 together with A8 to which they are attached form a 5- or 6-membered heterocycle substituted by R4 and R5; Z is any 5-, 6- or 7-membered carbon- or heterocycle, which may be cyclic or connected via a covalent bond to a central core, and is optionally substituted with 1, 2 or 3 (preferably 1) substituents selected from the group consisting of -Br, -Cl, -F, -I, -OH, Me, -CF3, Et, -OMe, -SMe and -NO2; R4 is any 5-, 6- or 7-membered carbo- or heterocycle, optionally substituted with one, two or three (preferably one) lipophilic substituents selected from the group consisting of -Br, -Cl, -F, -I, -CF3, Me, -Et, -OMe and -SMe; or R4 is hydrogen, methyl or COOH; R5 is a 5-, 6-, 7-, 8-, 9- or 10-membered carbo- or heterocycle optionally substituted with 1, 2 or 3 (preferably 1) lipophilic substituents selected from the group consisting of -Br, -Cl, -F, -I, -CF3, Me, Et, -OMe and -SMe; R6 is a 5-, 6- or 7-membered carbo- or heterocycle optionally substituted with 1, 2 or 3 (preferably 1) substituents selected from the group consisting of -Br, -Cl, -F, -I, -OH, -NO2, Me, -CF3, Et, -OMe and -SMe; Or R6 is H or When A7 participates in an annulated carbo- or heterocycle Z, A5 and A6 are N and A8 is selected from -N, -CH, -CH2-N, -CH2-CH or -NH-CH, preferably -CH2-N, -CH2-CH or -NH-CH; Here, R4, R5 and R6 preferably have molecular shapes and stereoelectronic properties complementary to the allosteric binding pocket.

[0188] In a further embodiment of the first or second aspect of the invention, the inhibitor has a structure of formula (II), wherein A5 is N One of A6 and A7 is C and participates in the annelated carbo- or heterocycle Z, and the other is N. A8 is N; L2 is CH2-CH2 and L3 is CH2-CH2 or CH2-CF2; or L2 and L3 together with A8 to which they are attached form a 5- or 6-membered heterocycle (preferably piperidine or pyrrolidine) substituted by R4 and R5; L4 absent; Z is a 6-membered carbocycle or heterocycle annulated to a central core, where Z is optionally substituted with 1, 2 or 3 (preferably 1) substituents selected from the group consisting of -Br, -Cl, -F, -I, -OH, Me, -CF3, Et, -OMe, -SMe and NO2; R4 is COOH or CH2N4; R5 is a 5-, 6-, 7- or 10-membered carbo- or heterocycle optionally substituted with 1, 2 or 3, preferably 1, lipophilic substituent selected from the group consisting of -Br, -Cl, -F, -I, Me, -CF3, Et, -OMe and -SMe; R6 is a 5- or 6-membered carbo- or heterocycle, optionally substituted with 1, 2 or 3, preferably 1, substituents selected from the group consisting of -Br, -Cl, -F, -I, -OH, -NO2, Me, -CF3, Et, -OMe and -SMe; Or R6 is H.

[0189] In a further embodiment of the first or second aspect of the invention, the inhibitor has a structure of formula (II), wherein Each of A5, A7 and A8 is N. A6 is C and is part of the cyclized carbo- or heterocycle Z; L2 is CH2-CH2-R4; L3 is CH2-CH2-R4; or L2 and L3 together with A8 to which they are attached form a piperidine or pyrrolidine ring substituted with R4 and R5; L4, absent; Z is phenyl or cyclohexyl cyclized to a central core, where Z is optionally substituted with 1, 2 or 3, preferably 1, substituents selected from the group consisting of -Br, -Cl, -F, -OH, Me, -CF3, -OMe and -NO2; R4 is COOH or tetrazolyl R5 is phenyl, cyclopentyl or adamantyl optionally substituted with one, two or three, preferably one, lipophilic substituent selected from the group consisting of -Br, -CF3, Me, -CH2-CF3 and -OMe; R6 is a 6-membered carbon- or heterocycle, preferably phenyl or cyclohexyl; more preferably phenyl, optionally substituted with 1, 2 or 3, preferably 1, substituents selected from the group consisting of Br, -Cl, -F, Me, -CF3, -OMe and -NO2.

[0190] In a further embodiment of the first or second aspect of the invention, the inhibitor has formula (IV): [ka] [During the ceremony, B is a 5-, 6- or 7-membered heterocycle containing 1, 2 or 3 heteroatoms selected from O, N or S; R7 is a 5-, 6- or 7-membered carbo- or heterocyclic ring optionally substituted with 1, 2 or 3, preferably 1, lipophilic substituent selected from the group consisting of -Br, -Cl, -F, -I, Me, Et, -OMe and -SMe; Z1 is selected from the group consisting of -Br, -Cl, -F, -I, -OH, -NH2, Me, -CF3, Et, -OMe, -SMe and -NO2; or Z1 is absent; X1 is O or S, preferably O; A9 is O, NH or CH2; A10 is O, NH or CH2; and R8 is a 5-, 6- or 7-membered carbo- or heterocyclic ring optionally substituted with 1, 2 or 3 (preferably 1) lipophilic substituents selected from the group consisting of -Br, -Cl, -F, -I, Me, Et, -OMe and -SMe. or a pharma- ceutically acceptable salt, isomer, solvate, chemically protected form, or prodrug thereof, Here, R7 and R8 preferably have molecular shapes and stereoelectronic properties that are complementary to the allosteric binding pocket.

[0191] In formula (IV) above, the "entry channel" and the "right channel" are shown merely to indicate the relative positions that the inhibitors of the invention occupy when bound to the binding pocket. Showing the positions of the two channels aids one skilled in the art in selecting appropriate substituents from those shown above that can bind to amino acids in the respective shown portions of the binding pocket. Thus, in a further embodiment of the first aspect, R7 is selected to bind to an amino acid in the entry channel, and R8 is selected to bind to an amino acid in the right channel.

[0192] In the above embodiments, the following are preferred: B is a 5-membered heterocycle consisting of 1, 2 or 3 heteroatoms selected from O, N or S, preferably 3 heteroatoms selected from N or S, more preferably 1,2,4-thiadiazaloyl. When B is 1,2,4-thiadiazaloyl, it is preferred that A9 is substituted at the 5-position and R7 is substituted at the 3-position of the 1,2,4-thiadiazaloyl.

[0193] In the above embodiments, the following are preferred: X1 is O; A9 is O or NH; A10 is O or NH; and B is a 5-membered heterocycle consisting of 1, 2 or 3 heteroatoms selected from O, N or S, preferably 3 heteroatoms selected from N or S, more preferably 1,2,4-thiadiazaloyl. When B is 1,2,4-thiadiazaloyl, it is preferred that A9 is substituted at the 5-position and R7 is substituted at the 3-position of the 1,2,4-thiadiazaloyl.

[0194] In the above embodiments, the following are preferred: X1 is O or S (preferably O); A9 is NH; A10 is NH; and B is a 5-membered heterocycle consisting of 1, 2 or 3 heteroatoms selected from O, N or S, preferably 3 heteroatoms selected from N or S, more preferably 1,2,4-thiadiazaloyl. When B is 1,2,4-thiadiazaloyl, it is preferred that A9 is substituted at the 5-position and R7 is substituted at the 3-position of the 1,2,4-thiadiazaloyl.

[0195] In the above embodiments, the following are preferred: X1 is O; A9 is O or NH; A10 is O or NH; B is a 5-membered heterocycle consisting of 1, 2 or 3 heteroatoms selected from O, N or S, preferably 3 heteroatoms selected from N or S, more preferably 1,2,4-thiadiazaloyl. When B is 1,2,4-thiadiazaloyl, it is preferred that A9 is substituted at the 5-position and R7 is substituted at the 3-position of the 1,2,4-thiadiazaloyl; and R7 is a 5- or 6-membered carbon- or heterocycle, preferably a 6-membered aryl or a 5- or 6-membered heteroaryl, optionally substituted with 1, 2 or 3, preferably 1, lipophilic substituent selected from the group consisting of -Br, -Cl, -F, -I, Me, Et, -OMe and -SMe, more preferably R7 is phenyl or a 5-membered heteroaryl, preferably a thiophenyl, optionally substituted with 1, 2 or 3, preferably 1, lipophilic substituent selected from the group consisting of Br, -Cl, -F, -I, Me, Et, -OMe and -SMe, more preferably unsubstituted phenyl or a thiophenyl substituted with 1 or 2, preferably 1, lipophilic substituent selected from the group consisting of -Br, -Cl, -F, -I, Me, Et, -OMe and -SMe.

[0196] In the above embodiments, the following are preferred: X1 is O or S (preferably O); A9 is NH; A10 is NH; B is a 5-membered heterocycle consisting of 1, 2 or 3 heteroatoms selected from O, N or S, preferably 3 heteroatoms selected from N or S, more preferably 1,2,4-thiadiazaloyl. When B is 1,2,4-thiadiazaloyl, it is preferred that A9 is substituted at the 5-position and R7 is substituted at the 3-position of the 1,2,4-thiadiazaloyl; and R7 is a 5- or 6-membered carbon- or heterocycle, preferably a 6-membered aryl or a 5- or 6-membered heteroaryl, optionally substituted with 1, 2 or 3, preferably 1, lipophilic substituent selected from the group consisting of -Br, -Cl, -F, -I, Me, Et, -OMe and -SMe, more preferably R7 is phenyl or a 5-membered heteroaryl, preferably a thiophenyl, optionally substituted with 1, 2 or 3, preferably 1, lipophilic substituent selected from the group consisting of Br, -Cl, -F, -I, Me, Et, -OMe and -SMe, more preferably unsubstituted phenyl or a thiophenyl substituted with 1 or 2, preferably 1, lipophilic substituent selected from the group consisting of -Br, -Cl, -F, -I, Me, Et, -OMe and -SMe.

[0197] In the above embodiments, the following are preferred: R7 is a 5- or 6-membered carbon- or heterocycle, preferably a 6-membered aryl or a 5- or 6-membered heteroaryl, optionally substituted with 1, 2 or 3, preferably 1, lipophilic substituent selected from the group consisting of -Br, -Cl, -F, -I, Me, Et, -OMe and -SMe, more preferably R7 is phenyl or a 5-membered heteroaryl, preferably a thiophenyl, optionally substituted with 1, 2 or 3, preferably 1, lipophilic substituent selected from the group consisting of Br, -Cl, -F, -I, Me, Et, -OMe and -SMe, more preferably unsubstituted phenyl or a thiophenyl substituted with 1 or 2, preferably 1, lipophilic substituent selected from the group consisting of -Br, -Cl, -F, -I, Me, Et, -OMe and -SMe.

[0198] In the above embodiments, the following are preferred: B is a 5-membered heterocycle consisting of 1, 2 or 3 heteroatoms selected from O, N or S, preferably 3 heteroatoms selected from N or S, more preferably 1,2,4-thiadiazaloyl. When B is 1,2,4-thiadiazaloyl, it is preferred that A9 is substituted at the 5-position and R7 is substituted at the 3-position of the 1,2,4-thiadiazaloyl; and R7 is phenyl or a 5-membered heteroaryl, preferably thiophenyl, optionally substituted with 1, 2 or 3, preferably 1, lipophilic substituents selected from the group consisting of -Br, -Cl, -F, -I, Me, Et, -OMe and -SMe, more preferably unsubstituted phenyl or thiophenyl substituted with 1 or 2, preferably 1, lipophilic substituents selected from the group consisting of -Br, -Cl, -F, -I, Me, Et, -OMe and -SMe.

[0199] In a further embodiment of the first or other aspects of the invention, the inhibitor has a structure of Formula (IV), where B is a 5-membered heterocycle containing 1, 2 or 3 heteroatoms selected from O, N, or S.

[0200] In a further embodiment of the first or second aspect of the invention, the inhibitor has the structure of formula (IV), wherein X1 is O A9 is O or NH; and A10 is O or NH.

[0201] In a further embodiment of the first or second aspect of the invention, the inhibitor has the structure of formula (IV), wherein X1 is O or S, preferably O A9 is NH; and A10 is NH.

[0202] In further specific embodiments of the first or second aspect of the invention, the inhibitor has the structure of formula (III): [ka] [During the ceremony, Each A4 is independently selected from N, NH, CH or CH2; Z1 is selected from the group consisting of -Br, -Cl, -F, -I, -OH, -NH2, Me, -CF3, Et, -OMe, -SMe and -NO2; or Z1 is absent; R7 is any 5-, 6- or 7-membered carbo- or heterocycle, optionally substituted with one, two or three (preferably one) lipophilic substituents selected from the group consisting of -Br, -Cl, -F, -I, Me, Et, -OMe and -SMe; R8 is any 5-, 6- or 7-membered carbon- or heterocycle, optionally substituted with one, two or three (preferably one) lipophilic substituents selected from the group consisting of -Br, -Cl, -F, -I, Me, Et, -OMe and -SMe. or a pharma- ceutically acceptable salt, isomer, solvate, chemically protected form, or prodrug thereof, Here, R7 and R8 preferably have molecular shapes and stereoelectronic properties that are complementary to the allosteric binding pocket.

[0203] In formula (III) above, the "entry channel" and the "right channel" are shown merely to indicate the relative positions that the inhibitors of the invention occupy when bound to the binding pocket. Showing the positions of the two channels aids one skilled in the art in selecting appropriate substituents from those shown above that can bind to amino acids in the respective shown portions of the binding pocket. Thus, in a further embodiment of the first aspect, R7 is selected to bind to an amino acid in the entry channel, and R8 is selected to bind to an amino acid in the right channel.

[0204] In the above embodiments, the following are preferred: R7 is a 5- or 6-membered carbon- or heterocycle, preferably a 6-membered aryl or a 5- or 6-membered heteroaryl, optionally substituted with 1, 2 or 3, preferably 1, lipophilic substituent selected from the group consisting of -Br, -Cl, -F, -I, Me, Et, -OMe and -SMe, more preferably R7 is phenyl or a 5-membered heteroaryl, preferably a thiophenyl, optionally substituted with 1, 2 or 3, preferably 1, lipophilic substituent selected from the group consisting of Br, -Cl, -F, -I, Me, Et, -OMe and -SMe, more preferably unsubstituted phenyl or a thiophenyl substituted with 1 or 2, preferably 1, lipophilic substituent selected from the group consisting of -Br, -Cl, -F, -I, Me, Et, -OMe and -SMe.

[0205] In the above embodiments, the following are preferred: A4 is N; and R7 is a 5- or 6-membered carbon- or heterocycle, preferably a 6-membered aryl or a 5- or 6-membered heteroaryl, optionally substituted with 1, 2 or 3, preferably 1, lipophilic substituents selected from the group consisting of -Br, -Cl, -F, -I, Me, Et, -OMe and -SMe, more preferably R7 is phenyl or a 5-membered heteroaryl, preferably a thiophenyl, optionally substituted with 1, 2 or 3, preferably 1, lipophilic substituents selected from the group consisting of Br, -Cl, -F, -I, Me, Et, -OMe and -SMe, more preferably unsubstituted phenyl or a thiophenyl substituted with 1 or 2, preferably 1, lipophilic substituents selected from the group consisting of -Br, -Cl, -F, -I, Me, Et, -OMe and -SMe.

[0206] In the above embodiments, the following are preferred: Z1 does not exist; A4 is N; and R7 is a 5- or 6-membered carbocyclic or heterocyclic ring, preferably a 6-membered aryl or a 5- or 6-membered heteroaryl, optionally substituted with 1, 2 or 3, preferably 1, lipophilic substituents selected from the group consisting of -Br, -Cl, -F, -I, Me, Et, -OMe and -SMe, more preferably R7 is phenyl or a 5-membered heteroaryl, preferably a thiophenyl, optionally substituted with 1, 2 or 3, preferably 1, lipophilic substituents selected from the group consisting of Br, -Cl, -F, -I, Me, Et, -OMe and -SMe, more preferably unsubstituted phenyl or a thiophenyl substituted with 1 or 2, preferably 1, lipophilic substituents selected from the group consisting of -Br, -Cl, -F, -I, Me, Et, -OMe and -SMe.

[0207] In the above embodiments, the following are preferred: R8 is cyclohexyl, piperidinyl, hexahydropyridazinyl, hexahydropyrimidinyl or piperazinyl, optionally substituted with one, two or three (preferably one) lipophilic substituents selected from the group consisting of -Br, -Cl, -F, -I, Me, Et, -OMe and -SMe.

[0208] In the above embodiments, the following are preferred: Z1 does not exist; A4 is N; and R8 is cyclohexyl, piperidinyl, hexahydropyridazinyl, hexahydropyrimidinyl or piperazinyl, optionally substituted with one, two or three, preferably one, lipophilic substituent selected from the group consisting of -Br, -Cl, -F, -I, Me, Et, -OMe and -SMe.

[0209] In a further embodiment of the first or second aspect of the invention, the inhibitor has the structure of formula (III): Each A4 is N or CH Z1 is selected from the group consisting of -Br, -Cl, -F, -I, -OH, -NH2, Me, -CF3, Et, -OMe, -SMe and -NO2; or Z1 is absent; R7 is any 5-, 6- or 7-membered carbon- or heterocycle, optionally substituted with one, two or three (preferably one) lipophilic substituents selected from the group consisting of -Br, -Cl, -F, -I, Me, Et, -OMe and -SMe; and R8 is any 5-, 6- or 7-membered carbon- or heterocycle optionally substituted with one, two or three, preferably one, lipophilic substituent selected from the group consisting of -Br, -Cl, -F, -I, Me, Et, -OMe and -SMe.

[0210] In a further embodiment of the first or second aspect of the invention, the inhibitor has the structure of formula (III): Each A4 is N Z1 is selected from the group consisting of -Br, -Cl, -F, -I, -OH, -NH2, Me, -CF3, Et, -OMe, -SMe and -NO2; or Z1 is absent; R8 is cyclohexyl, piperidinyl, hexahydropyridazinyl, hexahydropyrimidinyl or piperazinyl, optionally substituted with 1, 2 or 3, preferably 1, lipophilic substituents selected from the group consisting of -Br, -Cl, -F, -I, Me, Et, -OMe and -SMe; and R7 is a 5- or 6-membered carbo- or heterocycle (preferably a 5- or 6-membered aryl or heteroaryl group) optionally substituted with a methyl or ethyl group.

[0211] In a further embodiment of the first or second aspect of the invention, the inhibitor has the structure of formula (III): Each A4 is N The Z1 doesn't exist R8 is methylpiperidinyl, preferably 1-methylpiperidinyl R7 is phenyl optionally substituted with methyl or ethyl, or thiophene optionally substituted with methyl or ethyl; preferably, R7 is phenyl or methyl-substituted thiophenyl.

[0212] In particularly preferred embodiments of the first or second aspect of the invention, the inhibitor is selected from the group consisting of: [Table 2] [Table 3] [Table 4] [Table 5] [Table 6]

[0213] In particularly preferred embodiments of the first or second aspect of the invention, the inhibitor is selected from the following two compounds or a pharma- ceutically acceptable salt, isomer, solvate, chemically protected form or prodrug thereof: [Table 7]

[0214] Without wishing to be bound by any particular theory, Applicants speculate that the compound on the left (i.e., COVI-86) is converted in vivo to the compound on the right (i.e., COVI-87).

[0215] In a third aspect, the present invention is directed to a pharmaceutical composition comprising an inhibitor according to the first or second aspect of the invention.

[0216] In a fourth aspect, the present invention is directed to an inhibitor according to the first or second aspect of the invention or a pharmaceutical composition according to the third aspect of the invention for use in therapy.

[0217] In a fifth aspect, the present invention is directed to an inhibitor according to the first or second aspect of the invention or a pharmaceutical composition according to the third aspect of the invention for use in the prevention or treatment of a viral infection.

[0218] In a preferred embodiment of the fifth aspect of the invention, the viral infection is preferably an infection with a positive-sense single-stranded (ss) RNA virus of the class Pisoniviridae, more preferably a virus of the order Nidovirales, more preferably a virus of the suborder Cornidoviridae, and most preferably a virus of the family Coronaviridae. Most preferably, the virus is a coronavirus, in particular SARS-CoV, MERS-CoV, SARS-CoV-2 and variants thereof. EXAMPLES

[0219] experiment 1. In silico characterization First, a 12 μs molecular dynamics (MD) simulation was performed on the first lobe of SARS-CoV-1 Nsp13 helicase (residues 236 to 440 of SARS-CoV-1 Nsp13 PDB: 6JYT), which shares 100% sequence identity in this specific region with its SARS-CoV-2 orthologue. MD was started in implicit solvent. Simulations were performed using a step size of 2 femtoseconds. Simulations were run on an NVIDIA Tesla V100-SXM2-32gb GPU. MD began with an initial minimization step, followed by 10,000 steps of equilibration. Energies and frames were then written every 100 frames. After the MD simulation was completed, every 10 frames were taken from the trajectory. These frames were aligned to the initial pose using PCA. A plot of the PCA was created using the first two principal components. Eight clusters of protein conformations were manually identified. Random points near the center of each cluster were extracted as PDB files. Flexible docking was then performed on each of the eight protein conformations on an Intel(R) Xeon(R) Platinum 8268 CPU @ 2.90GHz cpu. Docking was performed using a proprietary compound library.

[0220] The average docking score of all protein conformations was used to rank the ligands in the library. The top 64 ligands were then selected for biochemical analysis. The in vitro data were correlated with molecular docking to each protein frame. The frame that correlated best with the in vitro FRET-based DNA unwinding assay measurements (Figure 12) was chosen as the representative structure to use for more rigorous molecular docking for pose refinement of biologically active molecules. Surprisingly, these docking poses revealed a previously unknown allosteric binding site located behind motif II of the active site inside the protein. This pocket was not visible in the crystal structure and was only identified by molecular dynamics simulations. The pocket shows a tripartite structure consisting of an entry channel, a left channel and a right channel. This pocket consists of the following amino acids of SARS-CoV / SARS-CoV-2 Nsp13: Y277, T279, L280, Q281, G282, T307, C309, F373, D374, E375, I376, S377, M378, A379, L384, N388, Y396, Y398, I399, G400, D401, P406, P408, N423, V425, C426, R427 and M429. Of these residues, Y277, L384, N388, Y396, Y398 and V425 form the entry channel, T307, C309, F373, D374, E375, S377, M378, A379 and N423 form the left channel, and T279, L280, Q281, G282, I376, I399, G400, D401, P406, P408, C426, R427 and M429 form the right channel. Table 1 lists each amino acid that directly correlates with three exemplary compounds, COVI-3, COVI-10 and COVI-35.

[0221] [Table 8]

[0222] Figure 3 shows an alignment of the amino acid sequences of the seven known coronovirus helicases. The alignment was generated using the Clustal Omega Multiple Sequence Alignment program available at EMBL-EBI (https: / / www.ebi.ac.uk / Tools / msa / clustalo / ) with standard alignment parameters. The amino acids of SARS-CoV-2 Nsp13 that are part of the allosteric binding pocket mentioned above are highlighted in bold, as are the amino acids of the other six coronavirus helicases at the corresponding positions in their respective helicases. The following Table 2 summarizes the level of conservation between the amino acids identified as forming the binding pocket of SARS-CoV-2 Nsp13 and the binding pockets of the other six coronavirus helicases.

[0223] [Table 9]

[0224] To further develop small molecule inhibitors that fit into the binding pocket and have specific favorable interactions, special attention has been paid to the following interactions between potential small molecules and proteins: Although most of the binding pocket is hydrophobic and therefore binding will be dominated by hydrophobic interactions, it is necessary to maximize the number of these favorable interactions while maintaining the physicochemical properties that result in favorable pharmacokinetic properties.

[0225] Hydrogen Bonding: Hydrogen bonding (H-bonding) is generally considered to be the most important aspect for small molecule binding. H-bonds form between lone pairs and polar, electron-deficient hydrogens at distances of 1.5 Å to 2.5 Å. The main chains of all amino acids contain both H-bond donors and acceptors, and many amino acid side chains have H-bond donors, acceptors, or both. The right and left channels of the binding pocket are rich in both H-bond donors and acceptors. In the entry channel, the number of H-bond donors and acceptors is less, especially as one approaches the center of the protein. This can be seen in Figure 6, where the black regions are hydrophobic and therefore poor in H-bond acceptors and donors. To take advantage of this, H-bond acceptors and donors should be located on the small molecule portions oriented towards the left and right channels, as well as on the outer boundaries of the entry channel.

[0226] Salt bridges: Several residues lining the binding pocket have charged side chains - notably aspartic acid 374 and 401, glutamic acid 375, and to some extent arginine 427 - and therefore have the potential to form salt bridges between the charged amino acid side chains and charged sites on small molecules. Salt bridges ideally form at distances of about 2 Å and can have interaction energies as low as two orders of magnitude kcal / mol, but often suffer from large desolvation penalties associated with charged moieties on small molecules. To access salt bridges, the charged sites can be oriented into the left or right channel.

[0227] π-π stacking: Interactions between π-bonding systems, especially aromatic π-bonding systems, are the most common intra- and intermolecular interactions. In proteins, several amino acids are capable of π-stacking with aromatic moieties in small molecules, which are phenylalanine, tyrosine, tryptophan and histidine. In the case of the allosteric binding pocket of SARS-CoV-2 Nsp13 helicase, one phenylalanine is shared in the left channel, two tyrosines in the entry channel and one tyrosine in the entry and right channels for π-stacking. These aromatic systems can be targeted for π-stacking by including complementary aromatic moieties in small molecules. At distances of 3.5 Å to 5 Å, both face-to-face and edge-to-face interactions are highly favorable.

[0228] Cation / polar-π: Cation-π and polar-π interactions occur between aromatic π systems and cations or electron-deficient polar regions. These interactions can be exploited in the left and entry channels of the binding pockets for phenylalanine and tyrosine, similar to (iii). To target these residues, small molecules must contain polar regions or cations that primarily approach the entry and left channels. Additionally, π systems in small molecules may interact with polar or charged amino acid side chains that primarily reside on the outer border of the entry channel, the left channel, and the right channel.

[0229] Halogen Bonding: Carbohalogens in small molecules have three important electronic interactions. The first is with the main chain carbonyl oxygen, which tends to occur at distances of 2.5 Å to 3.5 Å and is favored as the van der Waals radius of the halogen increases. In addition, carbohalogens interact with π systems in a manner similar to the polar-π interactions mentioned in (iv). Finally, carbohalogens, especially fluorine, can form strong bonds with sulfur atoms, especially the sulfur atoms in cystine. Because potential bonding interactions exist at many locations in the binding pocket, halogens can be added at many locations on the small molecule. There are π systems in the left channel, right channel, and entry channel that can be targeted by halogens. Main chain carbonyl oxygens can target primarily the left and right channels. Cystine sulfur is available in both the left and right channels.

[0230] Van der Waals: Nonspecific interactions between uncharged, nonpolar atoms of proteins and small molecules are the most abundant and at the same time the weakest. This interaction is present in all channels within the binding pocket, but is the only available interaction in the center of the entry channel, as can be observed by the concentration of hydrophobic residues in this region in Figure 8. Therefore, in developing new compounds, nonpolar substituents should be directed towards the center of the entry pocket.

[0231] The structures of compounds tested in the following assays were subsequently determined by this approach and then synthesized by various contract laboratories.

[0232] 2. Expression and purification of Nsp13 A plasmid encoding SARS-CoV-2 Nsp13 helicase with an N-terminal His10-SUMO tag was co-transformed with pGro7 (Takara Chaperone Plasmid Set #3340) into E. coli BL21 Gold (DE3) expression strain (Agilent Technologies 230132), plated on LB agar plates supplemented with chloramphenicol and kanamycin, and grown overnight at 37 °C. A swab from the LB agar plate was used to inoculate a preculture (LB supplemented with chloramphenicol and kanamycin) and grown overnight with shaking at 30 °C. This preculture was used to inoculate the expression culture 1:50 the next day. The expression culture was grown with shaking at 37 °C until the optical density (600 nm) was 0.5–0.8. Expression of the chaperone was then induced by adding 0.5 mg / ml (final concentration) L-arabinose. After an additional hour of shaking at 37° C., the culture was transferred to 25° C. and expression of Nsp13 was induced by the addition of 0.5 mM IPTG (final concentration). Expression was allowed to proceed for 15 hours at 25° C. before harvesting the bacterial cells by centrifugation.

[0233] Cells were suspended in 50 mM Tris pH 7.5, 500 mM NaCl, 1 mM MgCl2, 20 mM imidazole, 1 mM DTT supplemented with EDTA-free protease inhibitors (Roche) and lysed by sonication. The lysate was spun down at 20,000 x g (4 °C) for 30 min. Proteins were purified by IMAC using lysis buffer as wash buffer and 50 mM Tris pH 7.5, 500 mM NaCl, 1 mM MgCl2, 500 mM imidazole, 1 mM DTT as elution buffer. Elution fractions containing the target protein were pooled, supplemented with 1 mg His6-SenP2 protease, and dialyzed extensively against 20 mM Tris pH 7.5, 300 mM NaCl, 1 mM MgCl2, 1 mM DTT. 5 M NaCl was added to the dialyzed protein solution to a final concentration of 500 mM. Uncleaved His10-SUMO-Nsp13 and His6-SenP2 were removed by IMAC. The flow-through containing the untagged target protein was diluted with 20 mM Tris pH 7.5 to a final NaCl concentration of 50 mM, loaded onto a heparin column operated in 20 mM Hepes pH 7.5, 50 mM NaCl, 1 mM DTT, and eluted with a gradient to 50% 20 mM Hepes pH 7.5, 1 M NaCl, 1 mM DTT. Pure peak fractions were pooled, supplemented with 20% (v / v) glycerol, flash frozen in liquid nitrogen, and stored at -80°C.

[0234] 3. Nsp13 helicase unwinding assay A FRET-based DNA unwinding assay was established for SARSCoV2 Nsp13 with the amino acid sequence of SEQ ID NO: 1. The helicase unwinding assay monitors fluorescence resonance energy transfer (FRET) to detect the separation of a fluorescently labeled reporter strand from a loading strand modified with a quencher dye that is spectrally paired by Nsp13. Helicase unwinding reactions were performed in 384-well plates in 10 mM HEPES pH 7.4, 10 mM NaCl, 0.005% BSA, 2.5% glycerol, 2.5 mM MgCl2, 0.01% CHAPS, 2 mM DTT, and the reaction mixture contained 0.15 nM Nsp13 and 100 nM fluorescein- and black hole quencher-labeled dsDNA. The unwinding reaction was initiated by adding 200 μM ATP and 1 μM unlabeled single-stranded DNA (ssDNA / capture oligo, which prevents reannealing and permanently separates the reporter and loading strands), followed by shaking the plate at 1450 rpm for 5 s and sealing with foil suitable for fluorescence measurements. Fluorescence changes were immediately recorded on a BMG labtech PheraStar FSX reader (excitation wavelength 485 nm, emission wavelength 520 nm). Unwinding was performed for 20 min unless otherwise stated. The initial rate of Nsp13-mediated unwinding was determined by plotting the increase in fluorescence as a function of time and linear curve fitting the resulting kinetic traces. To profile compounds that modulate the unwinding activity of Nsp13, the enzyme and substrate were incubated in the presence of compound for 30 min before initiating unwinding by addition of ATP. The rate of unwinding (initial rate) was measured as above and compared to the unwinding rate in the absence of the putative modulator / compound.

[0235] 4. Malachite Green ATPase Assay To confirm active compounds with an orthogonal method, a malachite green assay was established to validate small molecules as inhibitors of ATP hydrolysis by the Nsp13 enzyme (Figure 4). The malachite green assay allows the detection of organophosphates liberated upon ATP hydrolysis by the helicase. 10 μL ATPase assay reactions were performed in clear 384-well plates in 10 mM HEPES pH 7.4, 10 mM NaCl, 0.005% BSA, 2.5% glycerol, 2.5 mM MgCl2, 0.01% CHAPS, 2 mM DTT, 2.5% DMSO. The reaction mixture contained 500 pM Nsp13 and 100 nM dsDNA of the same sequence as in the helicase assay. The reaction was initiated by the addition of 100 μM ATP, followed by shaking the plate at 1450 rpm for 5 s. The reaction was allowed to proceed for 5 min and then stopped by adding 20 μL of Biomol Green (Enzo Life Sciences). Four minutes after the reaction was stopped, the absorbance of the phosphomolybdate-malachite green complex was monitored at 650 nm on a Tecan Genios pro. Compounds that inhibit the ATPase activity of SARS-CoV-2 Nsp13 were profiled by incubating with the enzyme-substrate complex for 30 min before initiating the reaction with ATP. Percentage of inhibition was calculated by normalizing the blank-subtracted absorbance of the untreated blank-subtracted control.

[0236] 5. SARS-CoV-2 nanoluciferase assay using human ACE-2 expressing A549 cells SARS-CoV-2 nanoluciferase assays using A549 cells expressing the human ACE-2 receptor were performed in the laboratory of Pei-Yong Shi at the University of Texas Medical Branch on behalf of Eisbach. A549-ACE2 cells (12,000 per well) were seeded in 96-well clear plates in phenol red-free medium supplemented with 2% FBS. The following day, two-fold serial dilutions of compounds were added 1 h prior to SARS-CoV-2-Nluc infection. At 48 h post-infection, luciferase signals in lysed cells were measured using nanoluciferase substrate (Promega). Relative luciferase signals were calculated by normalizing luciferase signals in compound-treated groups to those in the DMSO-treated group (set as 100%). Experiments were performed in single replicates (MOI = 0.025) and in technical duplicates.

[0237] 6. SARS-CoV-2 antiviral assay using patient isolates in VeroE6 cells. TCID50 readout VeroE6 (10,000 cells per well) were seeded in DMEM medium supplemented with 10% FBS and 100 U penicillin / 0.1 mg / ml streptomycin in clear 96-well plates. The next day, 2-fold serial dilutions of compounds were added 1 h before infection with SARS-CoV-2 (primary SARS-CoV-2 isolate, Düsseldorf strain, MOI = 1). One hour after infection, cells were washed three times with PBS and replenished with compounds. 24 h after infection, cell culture medium from each well was collected and subjected to TCID50 measurement. TCID50 / mL values ​​were determined by crystal violet staining followed by scoring the amount of wells showing cytopathic effect. TCID50 was calculated by the Spearman-Carver algorithm.

[0238] CPE-based assay Clear 96-well plates were seeded with VeroE6 (10,000 cells per well) in DMEM medium supplemented with 10% FBS and 100 U penicillin / 0.1 mg / ml streptomycin. The following day, two-fold serial dilutions of compounds were added 1 h before infection with SARS-CoV-2 (primary SARS-CoV-2 isolate, Düsseldorf strain). Cell viability was measured by SRB assay 72 h post-infection. Absorbance at 510 nm was measured with a Tecan plate reader. Experiments were performed in technical quadruplicates at 1 MOI (MOI = 0.01, 2000 TCID50). Wells containing cells only and cells infected with virus were used as internal controls. Percentage of cytopathic effect (CPE) inhibition was defined as [(test compound-virus control) / (cell control-virus control)]*100.

[0239] N-protein ELISA VeroE6 (1,000 cells per well) were seeded in clear 96-well plates in DMEM medium supplemented with 10% FBS and 100 U penicillin / 0.1 mg / ml streptomycin. The next day, two-fold serial dilutions of compounds were added 1 h before infection with SARS-CoV-2 (primary SARS-CoV-2 isolate, Düsseldorf strain). After another 24 h, cells were fixed with 4% PFA, permeabilized with Triton, and blocked with FCS. Primary antibodies were against the N-protein. TMB was used as substrate. After 15 min, the reaction was stopped by adding HCl and measured at 450 nm in an ELISA reader. Measurements were normalized to cells treated with live virus and DMSO alone.

[0240] 7. hCoV-229e-Rluc Antiviral Assay Huh7 cells (100,000 per well) were seeded in white 96-well plates in DMEM medium supplemented with 10% FBS and 100 U penicillin / 0.1 mg / ml streptomycin. The next day, 2-fold serial dilutions of compounds were added 1 h before hCoV-229e-Rluc infection. At 24 h postinfection, luciferase signals in lysed cells were measured using a luminometer with coenterazine as a bioluminescence substrate. Relative luciferase signals were calculated by normalizing the luciferase signals of the compound-treated group to that of the DMSO-treated group (set as 100%). Experiments were performed at MOI = 0.01 and in technical duplicates.

[0241] 8. Compound Synthesis Synthesis of compounds of general formula (I) can be carried out according to the general synthetic scheme shown in Figure 17. The compounds prepared in Figure 17 are not shown in the compound list depicted in Figure 14, but rather reflect a base compound scaffold in which the phenyl group is unsubstituted (while some compounds depicted in Figure 14 have substitutions on the phenyl group).

[0242] For example, the synthesis of COVI-06 involves the first N-alkylation of 3-fluorobenzyl bromide with hydantoin in DMF using NaH as base at 0°C and warming to room temperature. In step 2, the product of step 1, 3-(3-fluorobenzyl)-2,4-imidazolidinedione, is condensed with DMF under reflux conditions for 6 hours to produce (5Z)-5-[(dimethylamino)methylidene]-3-[(3-methylphenyl)methyl]imidazolidine-2,4-dione. In step 3, 1-(4-chlorophenyl)ethan-1-one is aldol reacted with dimethyl carbonate under reflux conditions for 16 hours to produce ethyl 3-(4-chlorophenyl)-3-oxopropanoate. The reaction mixture of ethyl 3-(4-chlorophenyl)-3-oxopropanoate and (4-nitrophenyl)hydrazine hydrochloride is then refluxed in ethanol for 16 hours to produce pyrazole 3. The product of this step 4, 3-(4-chlorophenyl)-1-(4-nitrophenyl)-1H-pyrazol-5-ol, is then reacted with the product of step 2, (5Z)-5-[(dimethylamino)methylidene]-3-[(3-methylphenyl)methyl]imidazolidine-2,4-dione, in the presence of acetic acid under reflux for 4 hours to produce COVI-06.

[0243] The synthesis of COVI-20 consists of first converting (3-methoxyphenyl)methanol to 1-(bromomethyl)-3-methoxybenzene. As expected, the subsequent steps are the same as those of COVI-06. Step 2 is the N-alkylation reaction of 1-(bromomethyl)-3-methoxybenzene and hydantoin with DMF and NaH at 0°C to room temperature to produce 2-hydroxy-3-[(3-methoxyphenyl)methyl]imidazolidin-4-one. Step 3 is the condensation reaction of 2-hydroxy-3-[(3-methoxyphenyl)methyl]imidazolidin-4-one with DMF under reflux conditions for 6 hours to produce (5Z)-5-[(dimethylamino)methylidene]-2-hydroxy-3-[(3-methoxyphenyl)methyl]imidazolidin-4-one. In step 4, 1-(4-chlorophenyl)ethan-1-one and dimethyl carbonate are reacted under reflux for 16 hours to form ethyl 3-(4-chlorophenyl)-3-oxopropanoate. Then, in step 5, ethyl 3-(4-chlorophenyl)-3-oxopropanoate is reacted with (4-nitrophenyl)hydrazine hydrochloride in ethanol under reflux for 16 hours to form a pyrazole. The product of step 4 is 3-(4-chlorophenyl)-1-(4-nitrophenyl)-1H-pyrazol-5-ol, which is then reacted with (5Z)-5-[(dimethylamino)methylidene]-2-hydroxy-3-[(3-methoxyphenyl)methyl]imidazolidin-4-one in the presence of acetic acid under reflux for 4 hours to form COVI-20.

[0244] Similarly, the synthesis of compounds of general formula (II) can be carried out according to the general synthetic scheme shown in Figure 18. Again, the compounds prepared in Figure 18 are not shown in the compound list depicted in Figure 14, but rather reflect a base compound scaffold in which the phenyl group is unsubstituted (whereas some compounds depicted in Figure 14 have substitutions on the phenyl group).

[0245] Specifically, the synthesis of COVI-3 begins with the formation of a quinolinone between 2-aminobenzamide and 3-bromobenzaldehyde in step 1. In step 2, the product of step 1, 2-(3-bromophenyl)quinazolin-4-ol, undergoes chlorination with phosphoryl chloride to produce 2-(3-bromophenyl)-4-chloroquinazoline. 2-(3-bromophenyl)-4-chloroquinazoline is then subjected in step 3 to an amination reaction with ethyl 3-[(2-phenylethyl)amino]propanoate, which is generated by an alkylation reaction between ethyl 3-aminopropanoate and (2-bromoethyl)benzene in the presence of DMF and potassium carbonate at 120° C. for 2 hours, also in the presence of DMF and potassium carbonate at 120° C. for 8 hours, to generate ethyl 3-{[2-(3-bromophenyl)quinazolin-4-yl](2-phenylethyl)amino}propanoate in step 4. Subsequently, ethyl 3-{[2-(3-bromophenyl)quinazolin-4-yl](2-phenylethyl)amino}propanoate is subjected to an ester hydrolysis reaction with sodium hydroxide and THF-H2O at 0° C. to room temperature for 16 hours, followed by reflux for 3 hours, to generate COVI-3.

[0246] Similarly, the synthesis of COVI-72 begins with quinolinone formation between 2-aminobenzamide and 3-bromobenzaldehyde in step 1. In step 2, the product of step 1, 2-(3-bromophenyl)quinazolin-4-ol, is subjected to chlorination with phosphoryl chloride to generate 2-(3-bromophenyl)-4-chloroquinazoline. In parallel, 2-(3-ethyladamantan-1-yl)acetic acid is subjected to amide formation via acid chloride to generate 2-(3-ethyladamantan-1-yl)acetamide, which is reduced to the corresponding amine with lithium aluminum hydride and THF over 2 hours to generate 2-(3-ethyladamantan-1-yl)ethan-1-amine. Then, in step 3, 2-(3-ethyladamantan-1-yl)ethan-1-amine undergoes cyanoalkylation with prop-2-enenitrile by heating at 100° C. for 1 hour. The product of step 3, 3-{[2-(3-ethyladamantan-1-yl)ethyl]amino}propanenitrile, is used for aminoquinolinone formation using 2-(3-bromophenyl)-4-chloroquinazoline and dioxane as base at 120° C. for 16 h to give 3-{[2-(3-bromophenyl)quinazolin-4-yl][2-(3-ethyladamantan-1-yl)ethyl]amino}propanenitrile.

[0247] Finally, in step 5, tetrazole formation, 3-{[2-(3-bromophenyl)quinazolin-4-yl][2-(3-ethyladamantan-1-yl)ethyl]amino}propanenitrile is converted to COVI-72 by heating L-proline, DMF and sodium azide at 120° C. for 24 hours. Similarly, the synthesis of compounds of general formula (III) can be carried out according to the general synthetic scheme shown in FIG.

[0248] Specifically, COVI-35 can be prepared in two steps: first, aminothiazole formation is carried out using 2-bromo-1-phenylethan-1-one and thiourea in ethanol at 50°C for 6 hours to generate 4-phenyl-1,3-thiazol-2-amine, which then participates in a urea formation reaction with 1-methylpiperidin-4-amine, triphosgene and DCM for 2 hours to form COVI-35.

[0249] Additionally, COVI-85 can be produced in three steps starting with the Pinner reaction of ethanol with 3-methylthiophene-2-carbonitrile to form ethyl 3-methylthiophene-2-carboximidate using HCl as a catalyst. Similar to COVI-35, this is followed by aminothiadiazole formation between ethyl 3-methylthiophene-2-carboximidate and thiourea using potassium tert-butoxide, DMSO, and molecular iodine at room temperature for 16 hours. This forms 3-(3-methylthiophen-2-yl)-1,2,4-thiadiazol-5-amine, which is then used in step 3 urea formation reaction using 1-methylpiperidin-4-amine, triphosgene, and DCM for 2 hours to form COVI-85.

[0250] All rationally designed compounds as described in Example 1 were ordered under CDA from manufacturers Enamine (Riga, Latvia), ChemDiv (San Diego CA, USA) or Intonation Research Laboratories (Hyderabad, India) as shown in the table in Figure 20. The inhibitors of the present invention are simple molecules to synthesize and it is possible for one skilled in the art to synthesize such molecules without any inventive activity. Thus, there are many contract manufacturers that can custom manufacture such compounds if the structure to be synthesized is provided.

Claims

1. An inhibitor of the helicase activity of Nsp13 helicase (Nsp13) of SARS-CoV-2 or a viral homologue thereof for use in the prevention or treatment of viral infection, the inhibitor comprising: a) Formula (I): 【Chemistry 1】 [During the ceremony, A1 and A3 are each independently selected from N or C; A2 is selected from N, C or O; X is H, OH, or NH 2 and L1 is C, CH, CH 2 , O, N, and NH; or L1 is absent; Z is any 5-, 6-, or 7-membered carbo- or heterocycle substituted with R3, optionally further substituted, where R3 is connected through a bond or -CH 2 connected to Z via a - group; R1 is H or -NO 2 , -CN, -OH, -COOH, -NH-SO 2 -Alkyl, NH-CO-Alkyl, -CONH 2 , -CONH-alkyl, -Br, -Cl, -F, -I, Me, -CF 3 a 5-, 6- or 7-membered carbo- or heterocycle optionally substituted, independently of one another, with one, two or three (preferably one) substituents selected from the group consisting of -Et, -OMe and -SMe; R2 is H or -Br, -Cl, -F, -I, Me, or -CF 3 , -Et, -OMe and -SMe, wherein R2 is optionally substituted with one, two or three (preferably one) lipophilic substituents independently of one another from the group consisting of -CH 2 connected to A3 via a - group; R3 is H or any 5-, 6- or 7-membered carbo- or heterocycle; -NO 2 , -CN, -OH, -COOH, -NH-SO 2 -Alkyl, NH-CO-Alkyl, -CONH 2 , -CONH-alkyl, -Br, -Cl, -F, -I, Me, -CF 3 , -Et, -OMe, and -SMe, and optionally substituted with 1, 2, or 3 (preferably 1) independently substituted substituents selected from the group consisting of: -Et, -OMe, and -SMe. having the structure: b) Formula (II): 【Chemistry 2】 [During the ceremony, A5 and A8 are each independently selected from N or CH; A6 is selected from N or CH or, if A6 participates in an annulated carbo- or heterocycle Z, A6 is C; A7 is selected from N or CH or, if A7 participates in an annulated carbo- or heterocycle Z, A7 is C; L2 is selected from the group consisting of -CH2-R4, -CF2-R4, -CH2-CH2-R4, -CH2-CH2-CH2-R4, -O-R4, -NH-R4, -N=R4; L3 is selected from the group consisting of CH2-R5, -CF2-R5, -CH2-CH2-R5, -CH2-COH2-R5, -CH=CH-R5, -CH2-CF2-R5, -CH2-CH2-CH2-R5, -O-R5, -NH-R5, -N=R5; or L2 and L3 together with A8 to which they are attached form a 5- or 6-membered heterocycle substituted with R4 and / or R5; L4 is CH2, -CF2-, CH2-CH2, CH2-CH2-CH2, O, N, NH or absent; Z is a 5-, 6- or 7-membered carbo- or heterocycle optionally substituted with 1, 2 or 3, preferably 1, substituent selected from the group consisting of -Br, -Cl, -F, -I, -OH, Me, -CF3, Et, -OMe, -SMe and -NO2; and may be cyclized or linked via covalent bonds to the central core; R4 is a 5-, 6- or 7-membered carbo- or heterocycle optionally substituted with 1, 2 or 3, preferably 1, lipophilic substituent selected from the group consisting of -Br, -Cl, -F, -I, -CF3, Me, Et, -OMe and -SMe, or R4 is hydrogen, methyl or COOH; R5 is a 5-, 6-, 7-, 8-, 9- or 10-membered carbo- or heterocycle optionally substituted with 1, 2 or 3 (preferably 1) lipophilic substituents selected from the group consisting of -Br, -Cl, -F, -I, Me, -CF3, Et, -OMe and -SMe; R6 is a 5-, 6-, or 7-membered carbo- or heterocycle optionally substituted with 1, 2, or 3 (preferably 1) substituents selected from the group consisting of -Br, -Cl, -F, -I, -OH, -NO2, Me, -CF3, Et, -OMe, and -SMe; Or R6 is H; or When A7 occupies part of the cyclized carbocycle or heterocycle Z, A5 and A6 are independently selected from -N or -CH, and A8 is selected from -N, -CH, -CH2-N, -CH2-CH, or -NH-CH. or having the structure c) Formula (IV): 【Transformation 3】 [During the ceremony, B is a 5-, 6-, or 7-membered heterocycle containing 1, 2, or 3 heteroatoms selected from O, N, or S; R7 is a 5-, 6- or 7-membered carbo- or heterocyclic ring optionally substituted with 1, 2 or 3, preferably 1, lipophilic substituent selected from the group consisting of -Br, -Cl, -F, -I, Me, Et, -OMe and -SMe; Z1 is -Br, -Cl, -F, -I, -OH, -NH 2 ,Me,-CF 3 , Et, -OMe, -SMe and -NO 2 or Z1 is absent, X1 is O or S, preferably O; A9 is O, NH or CH 2 and A10 is O, NH or CH 2 and R8 is a 5-, 6-, or 7-membered carbo- or heterocyclic ring optionally substituted with 1, 2, or 3 (preferably 1) lipophilic substituents selected from the group consisting of -Br, -Cl, -F, -I, Me, Et, -OMe, and -SMe. having the structure: or a pharmaceutically acceptable salt, isomer, solvate, chemically protected form or prodrug thereof.

2. having the structure of formula (I), wherein: A1 is N substituted with R1 A2 is N A3 is C substituted with R2, where R2 is either through a bond or -CH 2 connected to A3 via a - group; X is H or OH; L1 is CH connected to CH= or Z 2 and Z is a 5- or 6-membered heterocycle, preferably heteroaryl, substituted with R3, optionally further substituted, where R3 is either through a bond or -CH 2 linked to Z via a - group; R1 is a 6-membered aryl or a 5- or 6-membered heteroaryl; 2 , -CN, -OH, -COOH, -NH-SO 2 -Alkyl, NH-CO-Alkyl, -CONH 2 , -CONH-alkyl, -Br, -Cl, -F, -I, Me, -CF 3 , -Et, -OMe, and -SMe; R2 is a 6-membered aryl or a 5- or 6-membered heteroaryl, and is selected from the group consisting of -Br, -Cl, -F, -I, Me, and -CF 3 Optionally substituted with 1, 2 or 3 (preferably 1) lipophilic substituents, independently of each other, selected from the group consisting of -Et, -OMe and -SMe; and R3 is a 6-membered aryl or a 5- or 6-membered heteroaryl; 2 , -CN, -OH, -COOH, -NH-SO 2 -Alkyl, NH-CO-Alkyl, -CONH 2 , -CONH-alkyl, -Br, -Cl, -F, -I, Me, -CF 3 , -Et, -OMe and -SMe, An inhibitor for use according to claim 1.

3. having the structure of formula (I), wherein: A1 is N substituted with R1 A2 is N A3 is C substituted with R2, where R2 is either through a bond or -CH 2 connected to A3 via a - group; X is H or OH; L1 is CH= connected to Z; Z is a 5-membered heterocycle, preferably heteroaryl, substituted with R3, optionally further substituted, where R3 is either through a bond or -CH 2 - group, preferably -CH 2 is linked to Z via a - group, more preferably imidazolidine-2,4-dionyl, wherein R3 is -CH at the 3-N position of imidazolidine-2,4-dionyl. 2 linked to Z via a - group; R1 is a 6-membered aryl or a 5- or 6-membered heteroaryl; 2 , -CN, -OH, COOH, NH-SO 2 -NH-CO-alkyl, -CONH 2 , -CONH-alkyl, -Br, -Cl, -F, -I, Me, -CF 3 , Et, -OMe and -SMe, and preferably, independently of each other, -NO 2 , -CN, -OH, COOH, NH-SO 2 -Alkyl, NH-CO-Alkyl, -CONH 2 and -CONH-alkyl; R2 is a 6-membered aryl or a 5- or 6-membered heteroaryl, and is selected from the group consisting of -Br, -Cl, -F, -I, Me, and -CF 3 optionally substituted with 1, 2 or 3, preferably 1, lipophilic substituent selected from the group consisting of -Et, -OMe and -SMe; R3 is a 6-membered aryl or a 5- or 6-membered heteroaryl optionally substituted with 1, 2 or 3. Preferably, each independently is -NO 2 , -CN, -OH, -COOH, -NH-SO 2 -Alkyl, NH-CO-Alkyl, -CONH 2 , -CONH-alkyl, -Br, -Cl, -F, -I, Me, -CF 3 , Et, -OMe and -SMe, preferably, independently of one another, -Br, -Cl, -F, -I, Me, -CF 3 , Et, -OMe, and -SMe, An inhibitor for use according to claim 1.

4. During the ceremony R1 is phenyl, 4-nitrophenyl, 2,6-dichloro-4-bromophenyl, 4-fluorophenyl, 4-bromophenyl, 2,6-dichlorophenyl, 2-methylphenyl, 4-methylphenyl, 2,3-dimethylphenyl or 4-methoxyphenyl; R2 is 2,4-dichlorophenyl, 4-chlorophenyl, phenyl, benzyl, 3-pyridine, 2-methylbenzyl, 4-fluorobenzyl, 4-chlorobenzyl, 2-methoxyphenyl, or 3-methoxyphenyl; and R3 is 4-fluorophenyl, 2-fluorophenyl, 3-fluorophenyl, 2,4-difluorophenyl, 2-methylphenyl, 3-methylphenyl, 4-methylphenyl, 2-chlorophenyl, 3-chlorophenyl, 3-pyridine, 3-methoxyphenyl, 4-nitrophenyl, 3-nitrophenyl, 4-trifluoromethyl-phenyl or 4-cyanophenyl; 2. The inhibitor for use according to claim 1, having the structure of formula (I):

5. having the structure of formula (II), wherein: A5 is N one of A6 and A7 is CH and the other is N; or one of A6 and A7 is C and forms an annulated carbo- or heterocyclic ring Z and the other is N; A8 is N or CH; An inhibitor for use according to claim 1.

6. having the structure of formula (II), wherein: A5 is N one of A6 and A7 is C and forms a cyclized 5-, 6- or 7-membered carbo- or heterocycle, preferably a 5- or 6-membered aryl or heteroaryl Z, and the other is N; A8 is N; L2 is CH 2 -CH 2 -R4 and L3 is CH 2 -CH 2 -R5 or CH 2 -CF 2 -R5, or L2 and L3 together with A8 to which they are attached form a 5- or 6-membered heterocycle, preferably piperidinyl or pyrrolidinyl substituted by R4 and R5; L4 is absent; Z is any 6-membered carbocycle or heterocycle, preferably a 6-membered aryl or heteroaryl annulated to a central core, where Z is -Br, -Cl, -F, -I, -OH, Me, -CF 3 , Et, -OMe, -SMe and NO 2 optionally substituted with 1, 2 or 3, preferably 1, substituents selected from the group consisting of: R4 is COOH or tetrazolyl; R5 is -Br, -Cl, -F, -I, Me, or -CF 3 any 5-, 6- or 7-membered carbo- or heterocycle optionally substituted with one, two or three, preferably one, lipophilic substituent selected from the group consisting of -Et, -OMe and -SMe; R6 is -Br, -Cl, -F, -I, -OH, -NO 2 ,Me,-CF 3 any 5- or 6-membered carbo- or heterocycle optionally substituted with 1, 2 or 3 (preferably 1) substituents selected from the group consisting of -Et, -OMe and -SMe; or R6 is H; An inhibitor for use according to claim 1.

7. having the structure of formula (II), wherein: Each of A5, A7 and A8 is N; A6 is C and is part of the annulated carbo- or heterocycle Z; Each of L2 and L3 is CH 2 -CH 2 or L2 and L3 together with A8 to which they are attached form a piperidine or pyrrolidine ring substituted by R4 and R5; L4 is absent; Z is a phenyl or cyclohexyl annulated to a central core, where Z is -Br, -Cl, -F, -OH, Me, -CF 3 , -OMe and -NO 2 optionally substituted with 1, 2 or 3, preferably 1, substituents selected from the group consisting of: R4 is COOH or tetrazolyl; R5 is -Br, -CF 3 , Me, -CH 2 -CF 3 and -OMe; R6 is Br, -Cl, -F, Me, or -CF 3 , -OMe and -NO 2 any 6-membered carbo- or heterocycle (preferably phenyl or cyclohexyl; more preferably phenyl), optionally substituted with 1, 2 or 3, preferably 1, substituents selected from the group consisting of: An inhibitor for use according to claim 1.

8. A compound having the structure of formula (IV), wherein: X1 is O A9 is O or NH; and A10 is O or NH or X1 is O or S A9 is NH; and A10 is NH; An inhibitor for use according to claim 1.

9. Formula (III) 【Chemistry 4】 [During the ceremony, Each A4 is independently N, NH, CH or CH 2 , preferably selected from N or CH Z1 is -Br, -Cl, -F, -I, -OH, -NH 2 ,Me,-CF 3 , Et, -OMe, -SMe and -NO 2 or Z1 is absent; R7 is any 5-, 6- or 7-membered carbo- or heterocycle optionally substituted with 1, 2 or 3, preferably 1, lipophilic substituent selected from the group consisting of -Br, -Cl, -F, -I, Me, Et, -OMe and -SMe; R8 is any 5-, 6-, or 7-membered carbon- or heterocycle optionally substituted with one, two, or three, preferably one, lipophilic substituent selected from the group consisting of -Br, -Cl, -F, -I, Me, Et, -OMe, and -SMe; preferably cyclohexyl, piperidinyl, hexahydropyridazinyl, hexahydropyrimidinyl, or piperazinyl, optionally substituted with one, two, or three, preferably one, lipophilic substituent selected from the group consisting of -Br, -Cl, -F, -I, Me, Et, -OMe, and -SMe.

2. The inhibitor for use according to claim 1, having the structure: or a pharmaceutically acceptable salt, isomer, solvate, chemically protected form or prodrug thereof.

10. having the structure of formula (III), wherein: Each A4 is N; Z1 is -Br, -Cl, -F, -I, -OH, -NH 2 ,Me,-CF 3 , Et, -OMe, -SMe and -NO 2 or Z1 is absent, preferably absent; R8 is cyclohexyl, piperidine, hexahydropyridazine, hexahydropyrimidine or piperazinyl, optionally substituted with 1, 2 or 3, preferably 1, lipophilic substituents selected from the group consisting of -Br, -Cl, -F, -I, Me, Et, -OMe and -SMe; R7 is a 5- or 6-membered carbocyclic or heterocyclic ring (preferably a 5- or 6-membered aryl or heteroaryl group) optionally substituted with a methyl or ethyl group; An inhibitor for use according to claim 9.

11. 2. The inhibitor for use according to claim 1, selected from the group consisting of the following or a pharmaceutically acceptable salt, isomer, solvate, chemically protected form or prodrug thereof: Table 1 Table 2 Table 3 Table 4 Table 5

12. 2. The inhibitor for use according to claim 1, selected from the group consisting of: Table 6

13. A pharmaceutical composition comprising an inhibitor described in any one of claims 1 to 12 for use in the prevention or treatment of viral infection.

14. The pharmaceutical composition of claim 13, wherein the viral infection is caused by a virus of the class Pisoniviricetes, preferably the order Nidovirales, more preferably a virus of the suborder Cornidovirus, and most preferably a virus of the family Coronaviridae.

15. A compound or a pharmaceutically acceptable salt, isomer, solvate, chemically protected form or prodrug thereof selected from the group consisting of: Table 7 Table 8

Images