A libramycin derivative and its use in nervous system diseases

Abstract

The present invention relates to the field of pharmaceutical chemistry technology, and more particularly to a libramycin derivative and its use in treating neurological diseases. The present invention enhances the neurological therapeutic activity by modifying the hydroxyl group at position 18 of libramycin. Furthermore, when the hydroxyl group is replaced with a methyl group, the compound's lipid solubility is increased, thereby improving brain transport efficiency.

Description

Technical Field

[0001] The present invention relates to the technical field of medicinal chemistry, and in particular to a libramycin derivative and use thereof in treating nervous system diseases. Background Art

[0002] Excitotoxicity is a common pathological phenomenon in many brain diseases. It is widely present in diseases such as epilepsy, Alzheimer's disease (AD), Parkinson's disease (PD), and amyotrophic lateral sclerosis (ALS). It is manifested by the accumulation of large amounts of excitatory neurotransmitters, mainly glutamate, which causes toxic damage to neurons and triggers a series of neuropathological changes1, including: (1) causing abnormal discharges in neurons, which in extreme cases can induce epilepsy; (2) overactivating nucleases and proteases in neurons, causing neurons to lose homeostasis; (3) causing oxidative stress damage to neurons; and (4) directly inducing neuronal apoptosis or autophagy in severe cases.

[0003] Excitotoxicity plays an important role in the pathogenesis of many neurological diseases and is considered to be one of the key factors that destroy normal brain function and cause neurodegenerative diseases. In the past, researchers mainly focused on the repair strategies that neurons may adopt after being damaged by excitotoxicity: alleviating or reversing the pathological phenotype of the disease through drug or molecular intervention, cell therapy and other methods. For example, in recent years, there have been many reports on neural stem cell transplantation and methods to inhibit neural apoptosis, which have brought hope for the treatment of diseases such as ALS, AD, and PD. However, there are also some problems with the above measures, such as the low survival rate of stem cells in cell transplantation therapy and the difficulty of integrating transplanted neurons into existing neural networks.

[0004] One hypothesis is that the limited effectiveness of these treatments stems from their inability to prevent the "strike mechanism" that persists throughout the disease process. Addressing the strike mechanism upstream of the disease might yield better therapeutic results.

[0005] Astrocytes maintain normal glutamate levels in the neural microenvironment by taking up and releasing glutamate. The glutamate transporter GLT1 (Glutamate transporter 1; also known as Excitatory amino acid transporter 2, EAAT2) plays a major role in glutamate clearance. 3 GLT1 is a membrane-integrated protein specifically expressed by astrocytes. It actively transports glutamate from the extracellular to the intracellular compartment, maintaining glutamate concentrations within the neural microenvironment within normal limits. Intracellular glutamate is converted to glutamine by glutamine synthetase (GS) and enters metabolic pathways. GLT1 also prevents excessive neuronal excitation by rapidly clearing glutamate from receptors on the postsynaptic membrane. Reports indicate that GLT1 can cause a 10,000-fold difference in glutamate concentrations between the extracellular and intracellular compartments. Studies have confirmed that GLT1 is the primary inward transporter of glutamate in the brain, responsible for nearly 80% of glutamate clearance.

[0006] Evidence shows that GLT1 is abnormally downregulated in a variety of neurological diseases, resulting in a severe loss of glutamate clearance ability in astrocytes, which may be an important cause of abnormal glutamate accumulation. Studies on patients with intractable temporal lobe epilepsy found that both GLT1 mRNA and protein were downregulated in the patients' epileptogenic foci (sclerotic hippocampal tissue). AD and epilepsy have certain comorbidities. Several studies have confirmed that AD patients also have neuronal damage caused by excitotoxicity in their brains. At the same time, GLT1 protein levels were found to be significantly decreased in autopsy brain tissue from AD patients. Studies on autopsy brain tissue from ALS patients found that the loss of GLT1 protein was as high as 90%. Subsequent functional studies have shown that abnormal internalization and protein degradation of GLT1 under pathological conditions may be an important cause of its insufficient protein amount. In addition, researchers have also observed the phenomenon of GLT1 downregulation in model mice of tuberous sclerosis.

[0007] Functional studies in animals have provided conclusive evidence for the relationship between GLT1 loss and disease phenotypes. First, GLT1 transgenic mice exhibit resistance to epileptic seizures. This is demonstrated by the reduction in hippocampal neuronal death, the alleviation of mossy fiber sprouting, and other pathological phenotypes associated with hippocampal sclerosis in response to an epilepsy-inducing drug (pilocarpine, a muscarinic acetylcholine receptor agonist, which can be used to establish a rodent model of epilepsy via intraperitoneal injection). Furthermore, the number of spontaneous chronic epileptic seizures in GLT1 transgenic mice is reduced by approximately 50%. Conversely, inhibition of GLT1 expression through injection of antisense RNA leads to a massive accumulation of glutamate in the brain, inducing neurodegeneration and progressive paralysis. These studies demonstrate that astrocytes, through their specific expression of GLT1, exert important neuroprotective functions and that GLT1 deficiency is sufficient to induce excitotoxic damage to the nervous system.

[0008] In summary, abnormal downregulation of GLT1 protein may be a key cause of excessive glutamate accumulation in the brains of patients with epilepsy, AD, and ALS. Recently, researchers have proposed a hypothesis of excessive GLT1 degradation, finding that HSP90 promotes 20S proteasome-dependent GLT1 degradation by recruiting GLT1 to the proteasome. Furthermore, reactive astrogliosis is a common pathological phenomenon in nearly all brain diseases, and this process is accompanied by elevated HSP90 expression. Therefore, treatment with HSP90 inhibitors can increase GLT1 protein levels in brain diseases such as temporal lobe epilepsy and AD. Regarding therapeutic efficacy, two HSP90 inhibitors, 17AAG and NVP-HSP990, alleviated seizures in mice with kainate-induced chronic temporal lobe epilepsy. In a mouse model of AD, NVP-HSP990 reduced epileptiform discharges in the brain and alleviated cognitive decline. Interestingly, because HSP90 expression levels in astrocytes are much lower than in neurons, and overall HSP90 expression levels in the brain are comparable to those in other tissues and organs, HSP90 inhibitors can be used to treat brain diseases at doses far lower than those used for severe tumor treatments, yet they can increase GLT1 protein levels and exert anti-epileptic and anti-AD effects. 18 These findings suggest that HSP90 inhibitors can be effective at low doses in treating brain diseases with neuroexcitotoxicity, such as epilepsy and AD.

[0009] However, existing HSP90 inhibitors have certain problems. For example, 17AAG and NVP-HSP990 each have disadvantages: 17AAG has poor drugability (low water solubility, low bioavailability, and toxicity); NVP-990 has been reported to have optic neurotoxicity in clinical trials; (2) More importantly, HSP90 inhibitors have significant limitations in treating brain diseases (such as blood-brain barrier permeability). Therefore, it is necessary to further optimize and modify them for the goal of "treating brain diseases."

[0010] Reblastatin is a type of aniline mycin, and its structural formula is as follows:

[0011]

[0012] Compared to 17AAG, this compound replaces the para-benzoquinone structure on the benzene ring with a phenol structure, thus reducing its toxicity. However, its drawback is that its brain-penetrating efficiency is extremely low, so it is necessary to modify its compound structure to improve its brain-penetrating efficiency. Summary of the Invention

[0013] The present invention provides a libramycin derivative and its use in treating neurological diseases. By modifying the hydroxyl group at position 18 of libramycin, the neurological therapeutic activity is enhanced. Furthermore, particularly when the hydroxyl group is replaced with a methyl group, the compound's lipid solubility is increased, thereby improving brain transport efficiency.

[0014] In order to achieve the above-mentioned purpose of the invention, the technical solution of the present invention is as follows:

[0015] In a first aspect, the present invention provides a use of a libramycin derivative or its stereoisomers, geometric isomers, tautomers, nitrogen oxides, hydrates, solvates, pharmaceutically acceptable salts or prodrugs in the preparation of a drug for treating and / or preventing a nervous system disease.

[0016] The structural formula of the libramycin derivative is shown in Formula I:

[0017]

[0018] Wherein, R is selected from H; halogen; amino; substituted or unsubstituted C1-5 alkyl, C1-5 alkoxy, C3-10 cycloalkyl, C1-5 ester, aryl, amine, heterocyclic group, and the substituted substituent is selected from at least one of C1-C5 alkyl, carbonyl, hydroxyl, C1-C5 alkyl, halogen, amine, aryl, and heterocyclic group.

[0019] Preferably, the R is selected from substituted or unsubstituted C1-5 alkyl, C1-5 alkoxy, C3-10 cycloalkyl, ester, aryl, amine, and heterocyclic groups, and the substituted substituent is selected from at least one of C1-C5 alkyl, carbonyl, hydroxyl, C1-C5 alkyl, halogen, amine, aryl, and heterocyclic groups.

[0020] Further preferably, the R is selected from a substituted or unsubstituted C1-5 alkyl group, a C1-5 ester group, or a heterocyclic group; the substituted substituent is selected from at least one of a carbonyl group, a hydroxyl group, a C1-C5 alkyl group, a halogen group, an amine group, an aryl group, and a heterocyclic group; and the heteroatom in the heterocyclic group is selected from at least one of N, S, B, and O.

[0021] More preferably, the R is selected from a substituted or unsubstituted C1-3 alkyl group, a C1-5 ester group, or a heterocyclic group; the substituted substituent is selected from at least one of a C1-C5 alkyl group, an amino group, and a heterocyclic group; and the heteroatom in the heterocyclic group is selected from at least one of N, S, B, and O.

[0022] More preferably, the R is selected from C1-3 alkyl, -OCO-Ra, and a substituted heterocyclic group, and the Ra and the substituted substituent are each independently selected from at least one of a C1-C3 alkyl, an amino group, and a heterocyclic group; and the heteroatom in the heterocyclic group is selected from at least one of N, S, B, and O.

[0023] More preferably, the R is selected from a C1-3 alkyl group, -OCO-Ra, a substituted heterocyclic group, the Ra is selected from at least one of an amino group and a heterocyclic group; the substituted substituent is selected from a C1-C3 alkyl group, and the heteroatom in the heterocyclic group is selected from at least one of N, B, and O.

[0024] More preferably, the R is selected from C1-3 alkyl, -OCO-Ra, at least one C1-3 alkyl-substituted pentacyclic heterocyclic group containing B and O, and the Ra is selected from at least one of an amino group and an N-containing six-membered heterocyclic group.

[0025] More preferably, the R is selected from methyl, -OCO-Ra, at least one C1-3 alkyl-substituted pentacyclic heterocyclic group containing B and O, and the Ra is selected from at least one of a C1-3 alkyl-substituted amino group, a piperazinyl group, and a C1-3 alkyl-substituted piperazinyl group.

[0026] More preferably, the R is selected from methyl, -OCO-Ra, at least one methyl-substituted pentacyclic heterocyclic group containing B and O, and the Ra is selected from at least one of dimethylamino, methylethylamino, diethylamino, piperazinyl, and methyl-substituted piperazinyl.

[0027] More preferably, the R is selected from methyl, -OCO-Ra, The Ra is selected from dimethylamino,

[0028] Most preferably, said R is methyl.

[0029] Preferably, the neurological disease is a brain disease.

[0030] Preferably, the neurological disease is selected from at least one of epilepsy, Alzheimer's disease, Parkinson's disease, and amyotrophic lateral sclerosis.

[0031] More preferably, it is at least one of epilepsy and Parkinson's disease.

[0032] In a second aspect, the present invention provides a libramycin derivative or a stereoisomer, geometric isomer, tautomer, nitrogen oxide, hydrate, solvate, pharmaceutically acceptable salt or prodrug thereof, the structural formula of which is shown in Formula I:

[0033]

[0034] The R is selected from methyl, -OCO-Ra, and a substituted heterocyclic group, and the Ra and the substituted substituent are each independently selected from at least one of a C1-C3 alkyl group, an amino group, and a heterocyclic group; the heteroatom in the heterocyclic group is selected from at least one of N, S, B, and O.

[0035] Preferably, the R is selected from C1-3 alkyl, -OCO-Ra, substituted heterocyclic group, the Ra is selected from at least one of amino group and heterocyclic group; the substituted substituent is selected from C1-C3 alkyl, and the heteroatom in the heterocyclic group is selected from at least one of N, B and O.

[0036] Further preferably, the R is selected from C1-3 alkyl, -OCO-Ra, at least one C1-3 alkyl-substituted pentacyclic heterocyclic group containing B and O, and the Ra is selected from at least one of an amino group and an N-containing six-membered heterocyclic group.

[0037] More preferably, the R is selected from methyl, -OCO-Ra, at least one C1-3 alkyl-substituted pentacyclic heterocyclic group containing B and O, and the Ra is selected from at least one of a C1-3 alkyl-substituted amino group, a piperazinyl group, and a C1-3 alkyl-substituted piperazinyl group.

[0038] More preferably, the R is selected from methyl, -OCO-Ra, at least one methyl-substituted pentacyclic heterocyclic group containing B and O, and the Ra is selected from at least one of dimethylamino, methylethylamino, diethylamino, piperazinyl, and methyl-substituted piperazinyl.

[0039] More preferably, the R is selected from methyl, -OCO-Ra, The Ra is selected from dimethylamino,

[0040] Most preferably, said R is methyl.

[0041] In a third aspect, the present invention provides a method for preparing the above-mentioned libramycin derivative, which is selected from the following methods:

[0042]

[0043] wherein R has the same definition as above.

[0044] Preferably, when R is a methyl group or a substituted heterocyclic group, the preparation method is:

[0045]

[0046] When R is -OCO-Ra, the preparation method is:

[0047]

[0048] In a fourth aspect, the present invention provides a pharmaceutical composition comprising the aforementioned libramycin derivative or its stereoisomers, geometric isomers, tautomers, nitrogen oxides, hydrates, solvates, pharmaceutically acceptable salts or prodrugs, and a pharmaceutically acceptable carrier or excipient.

[0049] The phrase "carrier" is art-recognized and includes pharmaceutically acceptable materials, components, or vehicles that are suitable for administering the compounds of the present invention to mammals. Carriers include liquid or solid fillers, diluents, excipients, solvents, or encapsulating materials that participate in carrying or transporting the subject substance from one organ or part of the body to another. Each carrier must be "acceptable" in the sense of being compatible with the other ingredients of the formulation or not injurious to the subject. Some examples of materials that can serve as pharmaceutically acceptable carriers include: sugars, such as lactose, glucose, sucrose; starches, such as corn starch and potato starch; cellulose and its derivatives, such as sodium methyl cellulose, ethyl cellulose, and cellulose acetate; tragacanth, malt, gelatin, talc; excipients, such as cocoa butter and suppository waxes; oils, such as peanut oil, cottonseed oil, safflower oil, sesame oil, olive oil, corn oil, and soybean oil; glycols, such as propylene glycol, polyols, such as glycerol, benzyl alcohol, glycerin, maltose, maltose, talc; excipients, such as cocoa butter and suppository waxes; oils, such as peanut oil, cottonseed oil, safflower oil, sesame oil, olive oil, corn oil, and soybean oil; glycols, such as propylene glycol, polyols, such as glycerol, benzyl alcohol, glycerin, maltose, maltose, talc; Sorbitol, mannitol, and polyethylene glycol, esters such as ethyl oleate and ethyl laurate, agar, buffers such as magnesium hydroxide and aluminum hydroxide, alginic acid, pyrogenic water, isotonic saline, ethanol, phosphate buffered saline, and other nontoxic compatible substances used in pharmaceutical formulations. Wetting agents, emulsifiers, and lubricants such as sodium lauryl sulfate and stearic acid esters, as well as coloring agents, release agents, coating agents, sweetening, flavoring and perfuming agents, preservatives, and antioxidants may also be present in the composition.

[0050] Examples of pharmaceutically acceptable antioxidants include: water-soluble antioxidants, such as ascorbic acid, cysteine ​​hydrochloride, sodium bisulfate, sodium metabisulfite, sodium sulfite, etc.; oil-soluble antioxidants, such as ascorbyl palmitate, butylated benzoic acid (BHA), butylated hydroxytoluene (BHT), lecithin, propyl gallate, α-tocopherol, etc.; and metal complexes, such as citric acid, ethylenediaminetetraacetic acid (EDTA), sorbitol, tartaric acid, phosphoric acid, etc.

[0051] Suitable pharmaceutically acceptable carriers include, but are not limited to, water, salt solutions (e.g., NaCl), alcohol, gum arabic, vegetable oils, benzyl alcohol, polyethylene glycol, gelatin, sugars (e.g., lactose, amylose, or starch), polyethylene glycol, magnesium stearate, talc, silicic acid, viscous paraffin, essential oils, fatty acid esters, methylcellulose, polyvinylpyrrolidone, etc. The pharmaceutical composition can be sterilized and, if desired, mixed with auxiliary agents such as lubricants, preservatives, stabilizers, wetting agents, emulsifiers, salt buffers for influencing osmotic pressure, colorants, flavorings and / or aromatic substances, etc., which do not deleteriously react with the active compounds.

[0052] The composition can also contain a wetting agent, emulsifier or pH buffer of minor amount. The composition can be a liquid solution, suspension, emulsion, tablet, pill, capsule, sustained release formulation or powder. The composition can be formulated into a suppository together with conventional adhesives and carrier (such as triglycerides). Oral formulations can include standard carriers such as pharmaceutical grade mannitol, lactose, magnesium stearate, polyvinylpyrrolidone, saccharin sodium, cellulose, magnesium carbonate etc.

[0053] According to ordinary method, described composition can be formulated into the pharmaceutical composition that is suitable for human intravenous administration.When needed, composition also can comprise stabilizing agent and local anesthetic, to alleviate the pain of injection site.Usually, composition is supplied separately or is mixed together in unit dosage form, for example, in sealed container such as ampoule or the sachet of the amount showing active agent as dry lyophilized powder or anhydrous concentrate.When composition is administered by infusion, it can be dispersed with the infusion bottle containing pharmaceutical grade sterile water, saline or glucose water.When composition is administered by injection, the sterile water for injection of an ampoule or saline can be provided, and composition can be mixed before administration.

[0054] The pharmaceutical compositions of the present invention may also include an agent that controls the release of the compound of the present invention, thereby providing a timed or sustained release composition.

[0055] The pharmaceutical compositions of the present invention include those suitable for oral, rectal, topical, vaginal and parenteral (including subcutaneous, intramuscular and intravenous) administration, although the most appropriate route in any particular case depends on the particular subject, the nature and severity of the condition to which the active ingredient is to be administered. The pharmaceutical compositions may be prepared by any method known in the art of pharmacy.

[0056] The active ingredient can be administered orally in solid dosage forms such as capsules, tablets, lozenges, troches, granules, and powders, or in liquid dosage forms such as elixirs, syrups, emulsions, dispersions, and suspensions. The active ingredient can also be administered parenterally in sterile liquid dosage forms such as dispersions, suspensions, or solutions. Other dosage forms that can be used to administer the active ingredient include ointments, creams, drops, transdermal patches, or powders for topical administration; ophthalmic solutions or suspensions, i.e., eye drops, for administration to the eye; sprays or powder compositions for inhalation or intranasal administration, or creams, ointments, sprays, or suppositories for rectal or vaginal administration. Gelatin capsules contain the active ingredient and a powdered carrier such as lactose, starch, cellulose derivatives, magnesium stearate, stearic acid, etc. Similar diluents can be used to prepare compressed tablets. Both tablets and capsules can be formulated as sustained-release products to provide sustained release of the drug over several hours. Compressed tablets can be coated with sugar or film to cover any unpleasant taste and protect the tablet from air, or can be enteric-coated for selective disintegration in the gastrointestinal tract. Liquid dosage forms for oral administration can include coloring agents and flavoring agents to increase patient acceptance. Generally speaking, water, suitable oil, saline, dextrose (glucose) aqueous solution and related sugar solution and glycols such as propylene glycol or polyethylene glycol are the carriers of suitable parenteral solutions. The solution for parenteral administration preferably includes a water-soluble salt of active ingredient, a suitable stabilizer and the buffer substance used as required. Antioxidant such as sodium bisulfite, sodium sulfite or ascorbic acid alone or in combination is a suitable stabilizer. Citric acid and its salt and sodium EDTA can also be used. In addition, parenteral solutions can also include preservatives, such as benzalkonium chloride, methylparaben or propylparaben and chlorobutanol.

[0057] For inhalation administration, compound of the present invention can be easily delivered in aerosol form from pressurized packaging or aerosol sprayer.The compound can also be delivered in the powder form prepared, and the powder composition can be sucked with the help of blowing into a powder inhaler device.The preferred delivery system for sucking is metered dose inhalation (MDI) aerosol, which can be formulated into a suspension or a solution of the compound of formula I in a suitable propellant, such as fluorocarbon or hydrocarbon.For eye administration, ophthalmic preparations can be prepared with a solution or a suspension of the appropriate weight percent of the compound of formula I in a suitable eye carrier, thereby keeping the compound in contact with the surface of the eye enough time so that the compound is infiltrated into the cornea and the inner area of ​​the eyes.

[0058] Useful pharmaceutical dosage forms for administering the pharmaceutical compositions of the present invention include, but are not limited to, hard and soft gelatin capsules, tablets, parenteral injection solutions, and oral suspensions.

[0059] In a fifth aspect, the present invention provides a method for treating a neurological disease, comprising administering to a subject an effective amount of the aforementioned libramycin derivative, or a stereoisomer, geometric isomer, tautomer, nitrogen oxide, hydrate, solvate, pharmaceutically acceptable salt, or prodrug thereof, or a pharmaceutical composition thereof. This method can be used in vivo or in vitro. The subject can be a mammal, such as a human.

[0060] When the compounds of the present invention are administered stepwise or in combination with other therapeutic agents, the same dosage forms as described above may be used. When the drugs are administered in a physical combination, the dosage form and route of administration should be selected based on the compatibility of the combined drugs. The compounds of the present invention may be administered as the sole active ingredient or in combination with a second active ingredient, including those known to be useful in treating related diseases.

[0061] In some embodiments, the amount of the compound is in the range of about 0.001 mg / kg body weight / day to about 1000 mg / kg body weight / day. In other embodiments, the amount of the compound is in the range of about 0.5 mg / kg body weight / day to about 50 mg / kg body weight / day. In some embodiments, the amount of the compound is in the range of about 0.001 g / day to about 7 g / day. In other embodiments, the amount of the compound is in the range of about 0.002 g / day to about 6 g / day. In other embodiments, the amount of the compound is in the range of about 0.005 g / day to about 5 g / day. In other embodiments, the amount of the compound is in the range of about 0.01 g / day to about 5 g / day. In other embodiments, the amount of the compound is in the range of about 0.02 g / day to about 5 g / day. In other embodiments, the amount of the compound is in the range of about 0.05 g / day to about 2.5 g / day. In other embodiments, the amount of the compound is in the range of about 0.1 g / day to about 1 g / day. In other embodiments, dosage levels below the lower limit of the above range may be sufficient. In other embodiments, dosage levels above the upper limit of the above range may be required. In some embodiments, the compound is administered in a single dose once a day. In other embodiments, the compound is administered in multiple doses more than once a day. In some embodiments, the compound is administered twice a day. In other embodiments, the compound is administered three times a day. In other embodiments, the compound is administered four times a day. In other embodiments, the compound is administered more than four times a day. In some embodiments, the individual to whom the pharmaceutical composition is administered is a mammal. In other embodiments, the mammal is a human.

[0062] Preferably, the neurological disease is selected from at least one of epilepsy, Alzheimer's disease, Parkinson's disease, and amyotrophic lateral sclerosis.

[0063] More preferably, it is at least one of epilepsy and Parkinson's disease.

[0064] Terminology Notes:

[0065] Unless otherwise defined, all technical and scientific terms used herein have the same meanings as commonly understood by those skilled in the art. Unless otherwise indicated, all patents, patent applications, and publications cited herein are incorporated by reference in their entirety. If multiple definitions of a term are used herein, the definition in this section shall prevail.

[0066] It should be understood that the above brief description and the following detailed description are exemplary and explanatory only and do not limit the subject matter of the present invention in any way. In the present invention, unless otherwise specifically stated, the use of the singular also includes the plural. It should also be noted that unless otherwise stated, the use of "or" and "or" means "and / or". In addition, the use of the term "including" and other forms such as "comprising", "including" and "containing" are not limiting.

[0067] Definitions of standard chemical terms can be found in the references (including Carey and Sundberg "ADVANCED ORGANIC CHEMISTRY 4THED." Vols. A (2000) and B (2001), Plenum Press, New York). Unless otherwise indicated, conventional methods within the skill of the art, such as mass spectrometry, NMR, IR and UV / Vis spectroscopy and pharmacological methods, are used. Unless specifically defined, the terms used herein in the descriptions of analytical chemistry, synthetic organic chemistry, and pharmaceuticals and medicinal chemistry are known in the art. Standard techniques can be used in chemical synthesis, chemical analysis, pharmaceutical preparation, formulation and delivery, and in the treatment of patients. For example, the manufacturer's instructions for use of the kit can be utilized, or reactions and purifications can be carried out in accordance with methods well known in the art or the description of the present invention. The above techniques and methods can generally be implemented according to conventional methods well known in the art, as described in the various general and more specific references cited and discussed in this specification. In this specification, groups and substituents thereof can be selected by those skilled in the art to provide stable structural moieties and compounds.

[0068] When a substituent is described by a conventional chemical formula written from left to right, the substituent also includes chemically equivalent substituents that would result if the formula were written from right to left. For example, CH2O is equivalent to OCH2.

[0069] Unless otherwise indicated, general chemical terms such as, but not limited to, "alkyl," "amine," and "aryl" are used to refer to their optionally substituted forms. For example, "alkyl" as used herein includes optionally substituted alkyl.

[0070] The term "optional" or "optionally" means that the event or situation described below may or may not occur, and the description includes both the occurrence of the event or situation and the non-occurrence of the event or situation. For example, according to the definition below, "substituted or unsubstituted" means "unsubstituted" (not substituted by a substituent) or "substituted alkyl" (substituted by a substituent).

[0071] The C 1-n Including C 1-2 、C 1-3 ,……C1-n For example, the "C1-C5" group means that the moiety has 1-5 carbon atoms, i.e., the group contains 1 carbon atom, 2 carbon atoms, 3 carbon atoms, or 4 carbon atoms. Thus, for example, "C 1-4 "Alkyl" refers to an alkyl group having 1 to 4 carbon atoms, i.e., the alkyl group is selected from methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, sec-butyl and tert-butyl. Numeric ranges herein, such as "1-10", refer to each integer in the given range, such as "1-10 carbon atoms" means that the group can have 1 carbon atom, 2 carbon atoms, 3 carbon atoms, 4 carbon atoms, 5 carbon atoms, 6 carbon atoms, 7 carbon atoms, 8 carbon atoms, 9 carbon atoms or 10 carbon atoms.

[0072] The term "alkyl" as used herein, alone or in combination, refers to an optionally substituted straight-chain or optionally substituted branched saturated aliphatic hydrocarbon. The "alkyl" herein preferably has 1 to about 20 carbon atoms, for example, 1 to about 10 carbon atoms, 1 to about 8 carbon atoms, or 1 to about 6 carbon atoms, or 1 to about 4 carbon atoms, or 1 to about 3 carbon atoms. Examples of alkyl groups herein include, but are not limited to, methyl, ethyl, n-propyl, isopropyl, 2-methyl-1-propyl, 2-methyl-2-propyl, 2-methyl-1-butyl, 3-methyl-1-butyl, 2-methyl-3-butyl, 2,2-dimethyl-1-propyl, 2-methyl-1-pentyl, 3-methyl-1-pentyl, 4-methyl-1-pentyl, 2-methyl-2-pentyl, 3-methyl-2-pentyl, 4-methyl-2-pentyl, 2,2-dimethyl-1-butyl, 3,3-dimethyl-1-butyl, 2-ethyl-1-butyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, isopentyl, neopentyl, tert-pentyl, and hexyl, as well as longer alkyl groups such as heptyl and octyl, etc. Groups defined herein, such as "alkyl" when presented in numerical ranges, for example, "C1-C6 alkyl" or "C 1-6 The term "alkyl" refers to an alkyl group which may be composed of 1 carbon atom, 2 carbon atoms, 3 carbon atoms, 4 carbon atoms, 5 carbon atoms or 6 carbon atoms. The alkyl group herein also includes the case where no numerical range is specified.

[0073] The "alkyl" used in combination herein includes alkyl groups linked to other groups, such as the alkyl group in alkoxy, the alkyl group in alkylthio, hydroxyalkyl, haloalkyl, cyanoalkyl, monoalkylamino, dialkylamino, etc.

[0074] The term "alkoxy" as used herein, alone or in combination, refers to an alkyl ether group (O-alkyl). Non-limiting examples of alkoxy include methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy, sec-butoxy, and tert-butoxy.

[0075] The term "aromatic group" as used herein, alone or in combination, refers to an optionally substituted aromatic hydrocarbon group having 6 to about 20, such as 6 to 12 or 6 to 10, ring-forming carbon atoms, which can be a monocyclic aromatic group, a bicyclic aromatic group, or a polycyclic aromatic group. A bicyclic aromatic group or a polycyclic aromatic group can be a monocyclic aromatic group fused to another independent ring, such as an alicyclic ring, a heterocyclic ring, an aromatic ring, or an aromatic heterocyclic ring. Non-limiting examples of monocyclic aromatic groups include monocyclic aromatic groups having 6 to about 12, 6 to about 10, or 6 to about 8 ring-forming carbon atoms, such as phenyl; bicyclic aromatic groups are exemplified by naphthyl; and polycyclic aromatic groups are exemplified by phenanthrenyl, anthracenyl, and azulenyl.

[0076] The term "heteroaryl" as used herein, alone or in combination, refers to an arbitrarily substituted heteroaryl group comprising from about 5 to about 20, such as 5 to 12 or 5 to 10 skeleton ring atoms, wherein at least one (such as 1-4, 1-3, 1-2) ring atom is a heteroatom independently selected from heteroatoms of oxygen, nitrogen, sulfur, phosphorus, silicon, selenium and tin, but not limited thereto. The ring of the group does not contain two adjacent O or S atoms. Heteroaryl includes monocyclic heteroaryl (having one ring), bicyclic heteroaryl (having two rings) or polycyclic heteroaryl (having more than two rings). In embodiments where two or more heteroatoms appear in the ring, the two or more heteroatoms may be the same as each other, or some or all of the two or more heteroatoms may be different from each other. Bicyclic heteroaryl or polycyclic heteroaryl may be a monocyclic heteroaryl fused to other independent rings, such as alicyclic, heterocyclic, aromatic, or aromatic heterocyclic rings (collectively referred to as fused ring heteroaryl). Non-limiting examples of monocyclic heteroaryl groups include monocyclic heteroaryl groups having 5 to about 12, 5 to about 10, 5 to about 7, or 6 backbone ring atoms, for example, non-limiting examples thereof include pyridyl; fused ring heteroaryl groups include benzimidazolyl, quinolinyl, and acridinyl. Other examples of heteroaryl groups include, but are not limited to, pyridine, pyrimidine, pyrazine, pyridazine, triazine, furan, thiophene, imidazole, triazole, tetrazole, thiazole, isothiazole, 1,2,4-thiadiazole, pyrrole, pyrazole, oxazole, isoxazole, oxadiazole, benzofuran, benzothiophene, benzothiazole, indole, indazole, quinoline, isoquinoline, purine, carbazole, benzimidazole, pyrrolopyridine, pyrrolopyrimidine, pyrazolopyridine, pyrazolopyrimidine, and the like; acridinyl, phenazinyl, benzoxazolyl, benzothiadiazolyl, benzoxadiazolyl, benzotriazolyl, isoquinolinyl, indolizinyl, isothiazolyl, and the like. The present invention also includes isothiazolyl, isoindolyl, oxadiazolyl, purinyl, phthalazinyl, pteridinyl, quinazolinyl, quinoxalinyl, triazinyl and thiadiazolyl, and oxides thereof, such as pyridyl N-oxide.

[0077] The term "heterocycle" or "heterocyclyl" as used herein, alone or in combination, refers to a non-aromatic heterocycle, including a saturated heterocycle or an unsaturated heterocycle (containing an unsaturated bond). One or more (e.g., 1-4, 1-3, 1-2) of the atoms forming the ring are heteroatoms, such as oxygen, nitrogen, or sulfur atoms. The heterocycle may include a monocyclic heterocycle (having one ring) or a bicyclic heterocycle (having two bridged rings) or a polycyclic heterocycle (having two or more bridged rings); spirocycles are also included. The heterocyclyl group may have 3 to about 20, such as 3 to about 10, 3 to about 8, 4 to 8, 4 to 7, 5 to about 8, or 5 to about 6 ring-forming atoms. Non-limiting examples of heterocyclic groups include azinyl, azetidinyl, oxetanyl, thietanyl, homopiperidinyl, oxepanyl, thiepanyl, oxazepinyl, diazepinyl, thiazepinyl, 1,2,3,6-tetrahydropyridinyl, 2-pyrrolinyl, 3-pyrrolinyl, indolinyl, 2H-pyranyl, 4H-pyranyl, dioxanyl, 1,3-dioxolanyl, pyrazolinyl, dithiocyclohex ... The term also includes saccharides such as thianyl, dithiolanyl, dihydropyranyl, dihydrothienyl, dihydrofuranyl, pyrazolidinyl, imidazolinyl, imidazolidinyl, 3-azabicyclo[3.1.0]hexyl, 3-azabicyclo[4.1.0]heptyl, 3H-indolyl, and quinolizinyl. The term also includes all cyclic forms of saccharides, including but not limited to monosaccharides, disaccharides, and oligosaccharides. Examples also include, but are not limited to, aziridine, tetrahydrofuran, tetrahydrothiophene, pyrrolidine, oxazolidine, thiazolidine, imidazolidine, isoxazolidine, isothiazolidine, pyrazolidine, morpholine, thiomorpholine, piperazine, piperidinyl, and the like.Heterocyclic groups also include heterocycles with one or more aromatic rings fused together (i.e., sharing a common bond), such as 2,3-dihydrobenzofuran, 1,3-benzodioxolane, benzo-1,4-dioxane, phthalimide, and naphthalimide. Heterocyclic groups with one or more aromatic rings fused together can be linked to other groups via aromatic or non-aromatic rings. It should be noted that heterocyclic groups include substituted heterocyclic groups, i.e., other groups are linked to the heterocyclic ring via heteroatoms or carbon atoms (i.e., the heterocyclic ring is linked to the parent molecule or further substituted).

[0078] "Halogen" refers to fluorine, chlorine, bromine, and iodine. Fluorine, chlorine, and bromine are preferred. Cyano is represented by "-CN"; hydroxy is represented by "-OH"; mercapto is represented by "-SH"; and amino is represented by "-NH2".

[0079] The term "ester group" has two connection forms, including R1-OCO-R2 and R1-COO-R2, wherein R1 and R2 refer to the substituents on both sides respectively, and R1 and R2 may be the same or different.

[0080] The term "substituted" means that one or more hydrogens on a specified atom are replaced by the specified radical and that the substitution results in a stable compound if the normal valence of the specified atom is not exceeded under the existing circumstances.

[0081] Unless otherwise specified, all ranges listed herein are inclusive. For example, "n is an integer between 0 and 2" means that n can be 0, 1 or 2.

[0082] The term "pharmaceutically acceptable salt" refers to a salt prepared from a pharmaceutically acceptable non-toxic base or acid. When the compound of the present invention is acidic, its corresponding salt can be readily prepared from an inorganic or organic base. Salts derived from such inorganic bases include salts of aluminum, ammonium, calcium, copper (copper and cuprous), iron, ferrous, lithium, magnesium, manganese (manganese and manganous), potassium, sodium, zinc, and the like. Preferred are salts of ammonium, calcium, magnesium, potassium, and sodium. Salts prepared from organic bases include primary, secondary, and tertiary amines derived from natural and synthetic sources. Pharmaceutically acceptable organic non-toxic bases that can form salts include arginine, betaine, caffeine, choline, N,N'-dibenzylethylenediamine, diethylamine, 2-diethylaminoethanol, 2-dimethylaminoethanol, ethanolamine, ethylenediamine, N-ethylmorpholine, N-ethylpiperidine, glucosamine, glucosamine, histidine, hydrabamine, isopropylamine, dicyclohexylamine, lysine, methylglucamine, morpholine, piperazine, piperidine, polyamine resins, procaine, purines, theobromine, triethylamine, trimethylamine, tripropylamine, tromethamine, etc. When the compound of the present invention is basic, its corresponding salt can be easily prepared from inorganic or organic acids. Such acids include, for example, acetic acid, benzenesulfonic acid, benzoic acid, camphorsulfonic acid, citric acid, ethanesulfonic acid, fumaric acid, gluconic acid, glutamic acid, hydrobromic acid, hydrochloric acid, isethionic acid, lactic acid, maleic acid, malic acid, mandelic acid, methanesulfonic acid, mucic acid, nitric acid, pamoic acid, pantothenic acid, phosphoric acid, succinic acid, sulfuric acid, tartaric acid, p-toluenesulfonic acid, and the like.

[0083] The term "solvate" refers to a complex of variable stoichiometry formed by a solute (i.e., a compound of Formula I) or a pharmaceutically acceptable salt thereof and a solvent that does not interfere with the biological activity of the solute. Examples of solvents include, but are not limited to, water, ethanol, and acetic acid. When the solvent is water, the solvate is referred to as a hydrate. Hydrates include, but are not limited to, hemihydrates, monohydrates, monosesquihydrates, dihydrates, and trihydrates.

[0084] The term "prodrug" refers to a functional derivative of a compound of the invention that is readily converted in vivo to the desired compound. Various prodrug forms are well known in the art. See, for example, Pro-drugs as Novel Delivery Systems (1987) Vol. 14 of the ACSSymposium Series, by T. Higuchi and V. Stella, Bioreversible Carriers in Drug Design, (1987) Edward B. Roche, ed., American Pharmaceutical Association, and Pergamon Press for a discussion of prodrugs. Design of Prodrugs, Bundgaard, A. Ed., Elseview, 1985 and Method in Enzymology, Widder, K. et al., Ed.; Academic, 1985, vol. 42, p. 309-396; Bundgaard, H. "Design and Application of Prodrugs" in A Textbook of Drug Design and Development, Krosgaard-Larsen and H. Bundgaard, Ed., 1991, Chapter 5, pp. 113-191; and Bundgaard, H., Advanced Drug Delivery Review, 1992, 8, 1-38, the above documents are incorporated herein by reference.

[0085] "Subject," "patient," or "individual" refers to an individual suffering from a disease, disorder, or condition, including mammals and non-mammals. Examples of mammals include, but are not limited to, any member of the class Mammalia: humans, non-human primates (e.g., chimpanzees and other apes and monkeys); livestock, such as cattle, horses, sheep, goats, and pigs; domestic animals, such as rabbits, dogs, and cats; and laboratory animals, including rodents, such as rats, mice, and guinea pigs. Examples of non-human mammals include, but are not limited to, birds and fish. In one embodiment of the methods and compositions provided herein, the mammal is a human.

[0086] The term "treating and / or preventing" and other similar synonyms include alleviating, reducing or ameliorating the symptoms of a disease or condition, preventing other symptoms, ameliorating or preventing the underlying metabolic causes of symptoms, inhibiting the disease or condition, such as preventing the development of the disease or condition, alleviating the disease or condition, making the disease or condition better, alleviating the symptoms caused by the disease or condition, or stopping the symptoms of the disease or condition. In addition, the term includes the purpose of prevention. The term also includes obtaining a therapeutic effect and / or a prophylactic effect. The therapeutic effect refers to the cure or improvement of the underlying disease being treated. In addition, the cure or improvement of one or more physiological symptoms associated with the underlying disease is also a therapeutic effect, for example, although the patient may still be affected by the underlying disease, the patient's condition is observed to improve. In terms of prophylactic effect, the composition can be administered to a patient at risk for a particular disease, or even if a diagnosis of the disease has not yet been made, the composition can be administered to a patient who has one or more physiological symptoms of the disease.

[0087] As used herein, the terms "effective amount," "therapeutically effective amount," or "pharmaceutically effective amount" refer to an amount of at least one agent or compound sufficient to provide some relief to some degree from one or more symptoms of the disease or condition being treated. This can result in a reduction and / or alleviation of signs, symptoms, or causes of disease, or any other desired change in a biological system. For example, a therapeutically effective amount is the amount of a composition comprising a compound disclosed herein that provides a clinically significant alleviation of symptoms. Techniques such as dose escalation studies can be used to determine the effective amount appropriate for any individual case.

[0088] As used herein, the terms "administer," "administer," "dosing," and the like refer to methods by which a compound or composition can be delivered to the desired site for biological action. These methods include, but are not limited to, oral routes, intraduodenal routes, parenteral injections (including intravenous, subcutaneous, intraperitoneal, intramuscular, intraarterial injection or infusion), topical, and rectal administration. Those skilled in the art are familiar with administration techniques that can be used for the compounds and methods described herein, such as those discussed in Goodman and Gilman, The Pharmacological Basis of Therapeutics, currented.; Pergamon; and Remington's, Pharmaceutical Sciences (current edition), Mack Publishing Co., Easton, Pa. In preferred embodiments, the compounds and compositions discussed herein are administered orally.

[0089] The term "acceptable" with respect to a formulation, composition or ingredient, as used herein, means having no long-term detrimental effect on the general health of the subject being treated.

[0090] As used herein, the term "pharmaceutically acceptable" refers to a substance (such as a carrier or diluent) that does not affect the biological activity or properties of the compounds of the present invention and is relatively non-toxic, that is, the substance can be administered to a subject without causing an adverse biological response or interacting in an adverse manner with any components contained in the composition.

[0091] The term "pharmaceutical composition" refers to a biologically active compound optionally mixed with at least one pharmaceutically acceptable chemical component, including but not limited to carriers, stabilizers, diluents, dispersants, suspending agents, thickeners and / or excipients.

[0092] The term "carrier" refers to relatively nontoxic chemical compounds or agents that facilitate the introduction of a compound into cells or tissues.

[0093] The term "neurological disease" refers to diseases that occur in the central nervous system, peripheral nervous system, and autonomic nervous system and are characterized by sensory, motor, consciousness, and autonomic dysfunction.

[0094] The beneficial effects of the present invention are as follows: the present invention provides a ribramycin derivative and its use in neurological diseases, which expands the application of ribramycin derivatives. At the same time, for brain neurological diseases, the present invention designs a new structure compound, which has excellent brain-penetrating performance, overcomes the problem of low brain-penetrating efficiency of current drugs, and shows greater advantages in the treatment of brain neurological diseases. BRIEF DESCRIPTION OF THE DRAWINGS

[0095] Figure 1 This is the mass spectrum detection diagram of compound I of the present invention.

[0096] Figure 2 This is the mass spectrum detection diagram of compound I-2 of the present invention.

[0097] Figure 3 This is the mass spectrum detection diagram of compound I-3 of the present invention.

[0098] Figure 4 This is the mass spectrum detection diagram of compound I-4 of the present invention.

[0099] Figure 5 This is a statistical analysis chart of IC50 after HepG2 cells were treated with different concentrations of 18-Me-Reblastatin and 17AAG.

[0100] Figure 6 The diagram shows the cytotoxicity results of I-2, I-3, and I-4.

[0101] Figure 7 Figure 2. Experimental results for increasing the GLT1 protein level in primary cultured astrocytes.

[0102] Figure 8 This is the GLT1 detection result diagram. The left side of the figure shows the Western blotting analysis results of mouse hippocampal tissue homogenate after 18-Me-Reblastatin injection. The target protein GLT1 and the internal reference protein Actin were detected respectively. The right side shows the statistical analysis results of the relative level changes of GLT1 protein.

[0103] Figure 9 This figure shows the protective effect of 18-Me-reblastatin on acute epilepsy induced by PTZ. The data are combined from the results of two animal experiments.

[0104] Figure 10 This is a statistical graph showing the frequency of epileptic seizures in male APP / PS1 mice.

[0105] Figure 11 This is the test result of mouse climbing pole and turning. DETAILED DESCRIPTION

[0106] The following non-limiting examples are provided to enable those skilled in the art to more fully understand the present invention, but are not intended to limit the present invention in any way. The following is merely an illustrative description of the scope of the present invention, and those skilled in the art may make various changes and modifications to the present invention based on the disclosed content, which should also fall within the scope of protection claimed in this application.

[0107] The present invention will be further described below by way of specific examples. The various chemical reagents used in the examples of the present invention were obtained through conventional commercial channels unless otherwise specified. Unless otherwise specified, the contents described below are all by weight. Unless otherwise specified, it is understood that the experiments were conducted at room temperature.

[0108] The compounds of the present invention having the various formulas described herein can be prepared from commercially available starting materials or starting materials that can be prepared using literature processes according to the processes described in the following general synthetic routes. The variables (e.g., R) in each general synthetic route are as defined herein. One of ordinary skill in the art will note that in the reaction procedures and synthetic schemes described herein, the order of certain steps may be varied, such as the introduction and removal of protecting groups.

[0109] In the present invention, 18-Me-Reb and 18-Me-Reblastatin both refer to Compound I.

[0110] Compound preparation

[0111] Example 118 - Preparation of Me-Reblastatin (Compound I)

[0112]

[0113] (1) Preparation of 18-OTf-Reblastatin (Compound III)

[0114] Compound II (274.3 mg) was dissolved in anhydrous DMF (2 mL), and DIPEA (0.26 mL), Tf2NPh (268 mg), and DMAP (7 mg) were added. The reaction flask was then placed in a 40°C oil bath and heated for 5 hours. TLC monitoring indicated the disappearance of the starting material spot. The reaction solution was cooled to room temperature, quenched with water, and extracted with ethyl acetate. The organic phases were combined, washed with saturated brine, dried over anhydrous sodium sulfate, filtered, concentrated under reduced pressure, and purified by column chromatography to obtain compound III (301 mg, 88% yield).

[0115] ESI (m / z): 703.72 [M+Na] +

[0116] (2) Preparation of 18-Me-Reblastatin (Compound I)

[0117] Compound III (301 mg), K 3 PO 4 (280 mg), and Pd(PPh 3 ) 4 (31 mg) were added to a single-necked round-bottom flask. The atmosphere was replaced with argon, followed by the addition of dioxane (10 mL). Ultrasonic degassing was performed, followed by the addition of a 3.5 M TMB solution in THF (151 μL). The reaction flask was then placed in an oil bath and heated at 100° C. for 4 hours. After completion of the reaction as monitored by TLC, the reaction solution was cooled to room temperature, quenched with water, and extracted with ethyl acetate. The combined organic phases were washed with saturated brine, dried over anhydrous sodium sulfate, filtered, concentrated under reduced pressure, and purified by column chromatography to obtain the target compound I (200 mg, 83% yield).

[0118] ESI (m / z): 569.32 [M+Na] +

[0119] Example 2 Preparation of Compound I-2

[0120]

[0121] Compound III (14 mg), KOAc (8 mg) and Pd(dppf)2Cl2 (2 mg) were added to a round-bottom flask, the atmosphere was changed to argon protection, dioxane (1 mL) was added, and ultrasonic degassing was performed. The reaction solution was then placed in an oil bath and heated to react (100°C) for 1 hour. The reaction solution was cooled to room temperature, diluted with ethyl acetate, quenched with water, separated, and extracted with ethyl acetate. The organic phases were combined, washed with saturated brine, dried over anhydrous sodium sulfate, filtered, concentrated under reduced pressure, and purified by column chromatography to obtain the target compound I-2 (7 mg, yield 52%).

[0122] ESI (m / z): 681.39 [M+Na] +

[0123] Example 3 Preparation of Compound I-3

[0124]

[0125] Compound I-3 (20 mg) was added to a round-bottom flask, the atmosphere was switched to argon, and DMF (2 mL) was added. The reaction solution was then cooled in an ice-water bath, potassium carbonate (10 mg) was added, followed by the acid chloride (5 μL), and the reaction mixture was allowed to warm to room temperature for 1 hour. After completion, the reaction was diluted with ethyl acetate, split with water, and extracted with ethyl acetate. The combined organic phases were washed with saturated brine, dried over anhydrous sodium sulfate, filtered, concentrated under reduced pressure, and purified by column chromatography to obtain the target compound I-3 (8 mg, 35% yield), and some raw material (10 mg, 50% recovery) was recovered.

[0126] ESI (m / z): 620.20 [M+Na] +

[0127] Example 4 Preparation of Compound I-4

[0128]

[0129] Compound I-3 (5 mg) was added to a round-bottom flask, and the argon atmosphere was replaced. DMF (0.5 mL) was added, and the reaction solution was placed in an ice-water bath to cool. Potassium carbonate (3 mg) was added, and then acyl chloride (2 mg) was added.

[0130] ), then warmed to room temperature and reacted for 1 hour. After completion of the reaction, the mixture was diluted with ethyl acetate, partitioned with water, and extracted with ethyl acetate. The combined organic phases were washed with saturated brine, dried over anhydrous sodium sulfate, filtered, concentrated under reduced pressure, and purified by column chromatography to obtain the target compound I-4 (4 mg, 65% yield).

[0131] ESI (m / z): 698.23 [M+Na] +

[0132] Effect testing

[0133] 1. Cytotoxicity assay

[0134] We used HepG2 cells to perform a CTG (CELL TITER-GLO) luminescence assay to detect cell proliferation inhibition. We screened 10 compounds. The compound screening concentrations were 0.005, 0.01, 0.05, 0.1, 0.5, 1, 5, 10, 20, and 50 μM, respectively. The cells were cultured in a cell culture incubator at 37°C and 5% CO2 for 2 days, and then CTG assays were performed. IC50 was calculated, and the results are shown below. Figure 5 As shown, it can be seen that the IC50 of 17AAG is 0.017 μM and the toxicity of 18-Me-Reb is 0.349 μM, which is much lower than the toxicity of 17AAG (19.5 times).

[0135] At the same time, we also evaluated the cytotoxicity of I-2, I-3, and I-4, e.g. Figure 6 , and the IC50 values ​​were found to be 0.301μM, 0.238μM, and 0.347μM, respectively. The results were similar to those of 18-Me-Reb, which were much lower than the toxicity of 17AAG.

[0136] 2. Experiment on increasing GLT1 protein level in primary cultured astrocytes

[0137] In order to test whether the above four compounds can increase the expression level of GLT1, we cultured primary astrocytes and treated them with the above four compounds on the 14th day after culture. The treatment doses were 0, 20, 50, 100, 200, and 400 nM. After 48 hours of compound treatment, astrocytes were collected and Western blotting was performed to detect the levels of GLT1 and Actin proteins. The results are shown in Figure 2. Figure 7 As shown, the results showed that all four compounds could increase the level of GLT1 protein.

[0138] 2. Experiment on increasing GLT1 protein level in mouse hippocampal tissue by 18-Me-reblastatin

[0139] 9-week-old C57 / BL6j mice (20 males and 20 females), 4 mice in each dose group (half males and half females), were injected intraperitoneally with 0, 1, 2, 4, and 8 mg / kg. On the morning of the 6th day after injection, the hippocampal brain tissue of the mice was obtained and homogenized. 10 μl (20 μg) of protein was taken for Western blotting analysis. The statistical method was One-way ANOVA. Figure 8 As shown in the figure, the protein level of GLT1 increased gradually in a dose-dependent manner and reached the maximum at 4 mg / kg injection.

[0140] 3. Blood-brain barrier permeability test

[0141] 3.1 Blood-brain barrier permeability test of compound I

[0142] First, the blood drug concentration of mice was tested after a single intraperitoneal injection at a dose of 4 mg / kg, and the relevant pharmacokinetic parameters and the compound's brain-to-blood ratio were calculated. The peak blood drug concentration time after injection was 0.14 hours, and the half-life (T1 / 2) of the compound was 2.07 hours. By measuring the compound concentration in the plasma and brain at 0.083, 0.167, and 0.5 hours after injection, the brain-to-blood ratios at these three time points were 0.35, 0.52, and 0.54, respectively. In other words, about half of the compound can pass through the brain, achieving the properties of a central nervous system drug.

[0143] Table 1. Blood drug concentrations of 18-Me-Reblastatin at different time points after one intraperitoneal injection

[0144]

[0145] In Tables 3-8, Mean: mean, SD: standard deviation, CV: coefficient of variation, BLQ: below limit of quantification (not detected), NA: not available.

[0146] Table 2. Pharmacokinetic parameters of 18-Me-Reblastatin

[0147]

[0148] In Table 2, IP: intraperitoneal injection, Mean: mean, SD: standard deviation, HL-Lambda-Z: half-life, AUC: area under the concentration-time curve, which represents the bioavailability of the drug (the degree to which the drug is absorbed and utilized in the human body). A larger AUC means higher bioavailability, and vice versa. (0-t) : AUC from time 0 to the final quantifiable time point, AUC (0-∞) : AUC from 0 to infinity time, T max : Time for drug concentration to reach peak, C max : peak concentration of the drug, AUClast: AUC from the start of drug administration to the last point, AUCINF-obs: AUC from the start of drug administration to the theoretically extrapolated infinite time, MRTlast: mean residence time from the drug administration time to the last quantifiable concentration time, MRTINF-obs: mean residence time of the drug from the start of drug administration to the theoretically extrapolated infinite time, T 1 / 2 : Drug half-life, MRT (0-t): The average residence time of the drug from time 0 to the final quantifiable time point, MRT (0-∞) : The average residence time of the drug from 0 to infinity.

[0149] Table 3. Brain concentration of 18-Me-Reblastatin 0.083 hours after intraperitoneal injection

[0150]

[0151] Table 4. Brain-to-blood ratio 0.083 hours after intraperitoneal injection of 18-Me-Reblastatin

[0152]

[0153] Table 5. Brain concentration of 18-Me-Reblastatin 0.167 hours after intraperitoneal injection

[0154]

[0155] Table 6. Brain-to-blood ratio 0.167 hours after a single intraperitoneal injection of 18-Me-Reblastatin

[0156]

[0157] Table 7. Brain concentration of 18-Me-Reblastatin 0.5 hours after intraperitoneal injection

[0158]

[0159] Table 8. Brain-to-blood ratio 0.5 hours after intraperitoneal injection of 18-Me-Reblastatin

[0160]

[0161] In Table 3-8, Mean: mean, SD: standard deviation, CV: coefficient of variation.

[0162] 3.2 Blood-brain barrier permeability assay of Reblastatin

[0163] The plasma and brain tissue concentrations of Reblastatin after intraperitoneal injection of mice were detected according to the above method. It was found that Reblastatin was almost undetectable in the brain. No concentration of the compound was detected in the brain 0.5 hours after intraperitoneal injection, indicating that its brain entry efficiency was low.

[0164] Table 9. Blood and brain tissue concentrations of Reblastatin

[0165]

[0166] In Table 9, IP: intraperitoneal injection, Mean: mean, SD: standard deviation, CV: coefficient of variation, BLQ: below limit of quantification (not detected), NA: not available.

[0167] 4. Protective effect of compound I in acute epilepsy induced by penetetrazol (PTZ)

[0168] PTZ is a central nervous system stimulant that primarily induces epileptic seizures by acting as a noncompetitive antagonist at GABA receptors. This inhibition reduces GABA-mediated inhibitory neurotransmission, leading to an imbalance between excitatory and inhibitory signaling in the brain. Consequently, neuronal excitability increases, inducing acute epileptic seizures. The PTZ-induced acute epilepsy model is commonly used for the rapid screening of anti-epileptic and anti-neuronal excitatory compounds.

[0169] Nine-week-old male C57 / BL6j mice were used. Eighteen mice were included in the control group and 15 mice were included in the 18-Me-Reblastatin group. On days 1, 3, and 5 of the experiment, 4 mg / kg of the compound dissolved in DMSO or the solvent control was injected intraperitoneally in a volume of 100 μl. At noon on day 6, PTZ was injected intraperitoneally at a dose of 55 mg / kg to induce epileptic seizures. The time of onset of the first epileptic seizure after PTZ injection and the Racine scale score for the maximum epileptic seizure were measured.

[0170] Racine Rating Scale:

[0171] 0) no seizure behavior;

[0172] 1) The behavior suddenly stops and the patient stares motionlessly;

[0173] 2) whisker tremors and / or facial and neck twitching;

[0174] 3) Orthoplastic seizures;

[0175] 4) Tonic-clonic seizures (prone);

[0176] 5) Tonic-clonic seizures (lying on one side, loss of postural control) or violent jumping.

[0177] The statistical method is Student's t test, and the results are as follows Figure 9Statistical results show that the average seizure onset time in the solvent control group was 80 seconds, while the average seizure onset time in the 18-Me-Reblastatin-treated group was 98 seconds. Regarding the Racine score, the average score in the solvent control group was 3.8 points, while the average score in the 18-Me-Reblastatin-treated group was 2.9 points. In summary, pretreatment with 18-Me-Reblastatin prolonged the onset time of PTZ-induced seizures and reduced the severity of seizures. This suggests that 18-Me-Reblastatin has a protective effect against PTZ-induced acute epilepsy.

[0178] 5. Anti-epileptic and cognitive improvement effects of compound I in the AD mouse model (APP / PS1)

[0179] Eight-month-old male APP / PS1 (carrying both APP695swe / PS1-dE9 mutations; Jacksonlab strain number 034832) mice were used. In the EEG test, there were 8 mice in each of the control group and the experimental group. After the electrodes were implanted, the baseline EEG recording was first monitored continuously for 24h×14 days. From the 15th day, the solvent control group or 18-Me-Reblastatin (4mg / kg) was injected intraperitoneally every other day for 7 consecutive times. Finally, the EEG recording was ended on the 14th day after the first injection. The effect of the compound was analyzed by comparing the baseline and post-drug epileptic seizures. Figure 10 The results showed that the solvent (DMSO) control group had no significant effect on seizure frequency, with a baseline of 1.08 seizures per day and a seizure frequency of 1.11 seizures per day after solvent injection. In the experimental group, the baseline seizure frequency was 0.96 seizures per day, and after 18-Me-Reblastatin treatment, the frequency dropped to 0.16 per day, a mean decrease of 83%.

[0180] 6. Protective effect of compound I in MPTP-induced PD model

[0181] To examine the therapeutic efficacy of 18-Me-Reblastatin in a Parkinson's disease mouse model, 37 8-week-old male c57 mice were randomly divided into three groups: a control group (n=8), a MPTP-induced model group (n=11), and an 18Me-treated group (n=18). The treated group received two pre-administrations of 18-Me-Reblastatin (4 mg / kg, ip) followed by MPTP-induced subacute Parkinson's disease modeling. Mice were intraperitoneally injected with 30 mg / kg of MPTP, while the control group received an equal volume of saline once daily for 14 days. During this period, the treated group received an intraperitoneal injection of 18-Me-Reblastatin (4 mg / kg) every other day, while the control and model groups received equal volumes of DMSO. Behavioral assessments were performed two weeks later.

[0182] Test 1: Pole Climbing Test. This test assesses the motor coordination of mice by observing their ability to grasp and descend a vertical pole. The experimental apparatus consists of a 1 cm diameter, 50 cm long wooden pole with a 2.5 cm diameter wooden ball fixed to its top. Gauze is wrapped around the vertical pole to prevent the mouse from slipping. During the test, the pole is held at a 90° angle to the ground. The mouse is placed on the top ball, and the time it takes for the mouse to spontaneously climb from the top to the bottom is recorded. Each mouse is tested three times, with at least 30 minutes between trials, and the three results are averaged.

[0183] Test 2: Rotarod test. This test assesses the coordinated movement and balance abilities of mice. Before all experiments, each mouse underwent three days of pre-training, with speeds set to 8 rpm, 12 rpm, and 16 rpm for 5 minutes. During the formal experiment, the rotarod was set to a uniform acceleration process from 4 rpm to 40 rpm for 10 minutes, and the time it took for the mouse to fall from the rotating rod was recorded. Each mouse was tested three times, with at least 30 minutes between experiments, and the three results were averaged.

[0184] The results are as follows Figure 11 The results showed that 18-Me-Reblastatin can significantly alleviate the motor impairment caused by MPTP, suggesting that 18-Me-Reblastatin also has a protective effect on PD.

[0185] Finally, it should be noted that the above content is only used to illustrate the technical solution of the present invention, rather than to limit the scope of protection of the present invention. Simple modifications or equivalent substitutions of the technical solution of the present invention by ordinary technicians in this field do not deviate from the essence and scope of the technical solution of the present invention.

Claims

1. A libramycin derivative or a pharmaceutically acceptable salt thereof, characterized in that: The structural formula of the libramycin derivative is shown in Formula I: Formula I Wherein, R is selected from methyl, -OCO-Ra, ; Ra is selected from dimethylamino, .

2. The libramycin derivative or a pharmaceutically acceptable salt thereof according to claim 1, characterized in that: The R is a methyl group.

3. The method for preparing the libramycin derivative according to any one of claims 1 to 2, characterized in that: Select from the following methods: ； or , wherein R has the same definition as in any one of claims 1-2.

4. The preparation method according to claim 3, characterized in that When R is a methyl group or a substituted heterocyclic group, the preparation method is: ； When R is -OCO-Ra, the preparation method is: 。 5. A pharmaceutical composition, characterized in that The invention comprises the libramycin derivative or a pharmaceutically acceptable salt thereof according to any one of claims 1 to 2, and a pharmaceutically acceptable carrier or excipient.

6. Use of the libramycin derivative or a pharmaceutically acceptable salt thereof according to any one of claims 1 to 2 in the preparation of a method for treating and / or preventing a nervous system disease.

7. The use according to claim 6, characterized in that The nervous system disease is a brain disease.

8. The use according to claim 6, characterized in that The nervous system disease is selected from at least one of epilepsy, Alzheimer's disease, Parkinson's disease, and amyotrophic lateral sclerosis.

9. The use according to claim 8, characterized in that The nervous system disease is selected from at least one of epilepsy and Parkinson's disease.

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