Reserpine ring fusion analogs and methods of making and using thereof

Abstract

Reserpine ring fusion analogs are described herein. Methods of making and using thereof are also described. Such analogs, and pharmaceutical compositions thereof, can be used, for example, in antimalarial therapies.

Description

[0001] RESERPINE RING FUSION ANALOGS AND METHODS OF MAKING AND USING THEREOF

[0002] CROSS REFERENCE TO RELATED APPLICATION

[0003] This application claims priority to U.S. Provisional Patent Application No.

[0004] 63 / 779,422, filed March 28, 2025, the disclosure of which is incorporated herein by reference.

[0005] FIELD OF THE INVENTION

[0006] The present invention is drawn to reserpine-derived ring fusion analogs and methods of making and using thereof, such as for the treatment of malaria, are described.

[0007] STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

[0008] This invention was made with Government support under Grant No.

[0009] R35GM153272 awarded by the National Institutes of Health. The Government has certain rights in the invention.

[0010] BACKGROUND OF THE INVENTION

[0011] Malaria is a serious and potentially fatal disease caused by single-celled apicomplexan parasites of the genus Plasmodium. These parasites infect female Anopheles mosquitoes and are transmitted to humans through the bite of an infected mosquito, which introduces the parasite into the bloodstream via its saliva. If not diagnosed and treated promptly, malaria can lead to life-threatening complications. According to the World Health Organization (WHO), an estimated 249 million cases and 608,000 malaria-related deaths occurred across 85 countries in 2022. The burden of disease is especially high in developing nations, where children under the age of five account for approximately 80% of all malaria deaths. Other high-risk groups include infants, pregnant women, travelers, and individuals with compromised immune systems, such as those with HIV or AIDS.

[0012] Malaria-related pathology arises from the ability of Plasmodium parasites to invade, replicate within, and exit (egress) red blood cells (RBCs). These invasion and egress events are important steps in the blood-stage of the parasite's life cycle, the phase responsible for one or more of the clinical symptoms of malaria. At least eight Plasmodium species are known to infect humans: P. falciparum, P. vivax, P. malariae, P. ovale curtisi, P. ovale wallikeri, P. knowlesi, and the zoonotic species P. simium and P. cynomolgi. Among these, P. falciparum is the most virulent and is responsible for the 1

[0013] 45835266.1majority of malaria-related deaths worldwide. Therefore, there is a need for improved antimalarial therapies that effectively target the blood-stage of Plasmodium infection.

[0014] There is also a significant need for new agents to combat malaria, which resulted in —409,000 deaths globally in 2019. However, the fight against diseases like malaria remains complicated by drug resistance, toxicity, and slow drug development issues. Addressing these challenges requires development of new antimalarial agents and methods of making such agents.

[0015] Therefore, it is the object of the present invention to provide such new agents and methods that can address the aforementioned issues and methods of making thereof.

[0016] It is a further object of the present invention to provide pharmaceutical compositions including such agents.

[0017] It is yet a further object of the present invention to provide methods of using such pharmaceutical compositions to treat diseases in a subject.

[0018] SUMMARY OF THE INVENTION

[0019] Reserpine-derived ring fusion analogs and methods of making and using thereof are described herein.

[0020] In one non- limiting instance, a reserpine ring fusion analog has a structure of Formula I as follows:

[0021]

[0022] Formula (I)

[0023] wherein each X is a halogen; and

[0024] wherein R is a substituted or unsubstituted Ci-Ce alkyl, a substituted or unsubstituted C3-C10 cycloalkyl, or a substituted or unsubstituted benzyl group.

[0025] 2

[0026] 45835266.1In another non-limiting instance, a reserpate ring fusion analog has a structure of Formula II as follows:

[0027]

[0028] Formula (II)

[0029] wherein each X is a halogen;

[0030] wherein R is a substituted or unsubstituted Ci-Ce alkyl or a substituted or unsubstituted benzyl; and

[0031] wherein R’ is a hydrogen or carboxyl moiety (-C(O)-R”), wherein R” is a substituted or unsubstituted Ci-Ce alkyl, substituted or unsubstituted Cs-Cs cycloalkyl, substituted or unsubstituted C5-C12 aryl group, or substituted or unsubstituted C5-C12 heteroaryl group.

[0032] In some instances, the reserpine ring fusion analogs described herein form part of a pharmaceutical composition. The pharmaceutical composition includes an effective amount of the reserpine ring fusion analog and optionally one or more pharmaceutically acceptable carriers and / or excipients.

[0033] In one non-limiting instance, a pharmaceutical composition includes: a plurality of the reserpine ring fusion analog; at least one pharmaceutically acceptable earner; and optionally a pharmaceutically acceptable excipient.

[0034] The reserpine-derived ring fusion analogs of Formulae I and II can be prepared according to the non- limiting exemplary synthetic methods. In one non-limiting instance, a method of synthesizing a reserpine ring fusion analog includes the steps of:

[0035] (i) reacting a mixture of an a-haloamide having a structure of Formula III as follows:

[0036] 3

[0037] 45835266.1

[0038]

[0039] Formula (III)

[0040] wherein each X is a halogen; and

[0041] wherein R is a substituted or unsubstituted Ci-Ce alkyl, a substituted or unsubstituted C3-C13 cycloalkyl, or a substituted or unsubstituted benzyl group;

[0042] a reserpine in an organic solvent, wherein the reserpine has the following structure:

[0043]

[0044] a base compound to produce the reserpine ring fusion analog.

[0045] In another non-limiting instance, a method of synthesizing a reserpate ring fusion analog includes the steps of:

[0046] (i) reacting a mixture of an a-haloamide having a structure of Formula III as follows:

[0047]

[0048] Formula (III)

[0049] wherein each X is a halogen; and

[0050] wherein R is a substituted or unsubstituted Ci-Ce alkyl, a substituted or unsubstituted C3-C13 cycloalkyl, or a substituted or unsubstituted benzyl group;

[0051] a reserpate in an organic solvent, wherein the reserpine has the following structure:

[0052] 4

[0053] 45835266.1

[0054]

[0055] a base compound to produce the reserpate ring fusion analog.

[0056] Variants of the reserpate ring fusion analogs are also possible, such as by acylation. For instance, a method of synthesizing a variant of a reserpate ring fusion analog can include the steps of:

[0057] (i1) reacting a mixture of a reserpate fusion analog of Formula IV having the following structure:

[0058]

[0059] Formula (IV)

[0060] wherein each X is a halogen;

[0061] and an acyl chloride having the following structure:

[0062] O

[0063] C

[0064]

[0065] I^R

[0066] wherein R is a substituted or unsubstituted Ci-Ce alkyl, substituted or unsubstituted Cs-Cs cycloalkyl, substituted or unsubstituted C5-C12 aryl group, or substituted or unsubstituted C5-C12 heteroaryl group; wherein the mixture comprises at least one base compound.

[0067] Methods of using the reserpine-derived ring fusion analogs and pharmaceutical compositions thereof are also provided for reducing or preventing one or more symptoms associated with Plasmodium parasitic infection in a subject in need thereof. The methods include administering a pharmaceutical composition containing one or more reserpine and / or reserpate ring fusion analogs (e.g., compounds of Formulae I or II) in a therapeutically or prophylactically effective amount to provide an antimalarial effect. The compositions are capable of inhibiting, killing, or preventing the replication of 5

[0068] 45835266.1Plasmodium parasites (e.g., Plasmodium falciparum), and can be used to treat subjects with active malaria infection or to prevent infection in subjects at risk of being infected by a Plasmodium parasite .

[0069] For therapeutic applications, the pharmaceutical composition can be administered during the asexual blood stage of the Plasmodium life cycle, including the ring, trophozoite, and / or schizont stages, to reduce parasite burden, block replication, and prevent reinvasion of red blood cells. In some forms, administration occurs within 40 hours post-invasion of red blood cells, optionally within 30 hours, targeting the metabolically active trophozoite or early schizont stages and interfering with parasite maturation. In prophylactic applications, the composition can be administered to uninfected subjects to prevent initial colonization or replication following exposure to a Plasmodium parasite. In some forms, the compositions are administered in an amount effective to reduce one or more molecular and / or cellular markers of Plasmodium infection, such as parasite DNA levels, antigen presence, or the number of infected red blood cells, compared to levels observed in the same subject prior to treatment or in a comparable subject who did not receive the composition, as measured by flow cytometry, PCR, or other molecular methods known in the art. In other forms, the compositions are administered in an amount effective to reduce one or more clinical and systemic symptoms associated with a Plasmodium infection or a disease associated with a Plasmodium infection (e.g., malaria), such as fever, chills, fatigue, anemia, kidney injury, seizures, organ failure, and ARDS.

[0070] BRIEF DESCRIPTION OF THE DRAWINGS

[0071] Figure 1 shows various non- limiting reach schemes for the ring fusion of reserpine.

[0072] Figures 2A and 2B show various non-limiting reserpine-derived ring fusion analogs.

[0073] Figure 3 shows a reaction scheme for forming various reserpine-derived ring fusion analogs and details thereof.

[0074] Figure 4 shows a reaction scheme for forming various reserpate ring fusion analogs and details thereof.

[0075] Figure 5 shows a representative flow cytometry quantification from the parasite DNA content that shows stage-specific activity of MG-2-75 in P. falciparum Dd2 cells. Dd2 culture was synchronized by using a MACS column and 5% sorbitol. The culture was then diluted to 1% parasitemia and 2% hematocrit. Compounds were added at 5x 6

[0076] 45835266.1EC50 concentrations at 6, 18, 30 and 42 HPI (hours post invasion). DMSO and DHA were used as negative and positive controls, respectively. Samples were collected every 12 hours at every stage until the reinvasion at 54 HPI.

[0077] DETAILED DESCRIPTION OF THE INVENTION

[0078] Reserpine-derived ring fusion analogs and methods of making and using thereof are described herein. Such reserpine-derived ring fusion analogs can be used for treating, for instance, malaria, as described below.

[0079] I. Definitions

[0080] It is to be understood that the disclosed compounds, compositions, and methods of use are not limited to specific synthetic methods, specific analytical techniques, or to particular reagents unless otherwise specified, and, as such, may vary. It is also to be understood that the terminology used herein is for the purpose of describing particular forms and embodiments only and is not intended to be limiting.

[0081] The term “subject,” as used herein, refers to a mammal, such as a human.

[0082] The term “effective amount” or “therapeutically effective amount” refers to the amount of a compound or agent which is able to treat one or more symptoms of a disease or disorder, reverse the progression of one or more symptoms of a disease or disorder, halt the progression of one or more symptoms of a disease or disorder, or prevent the occurrence of one or more symptoms of a disease or disorder in a subject to whom the formulation is administered, for example, as compared to a matched subject not receiving the compound. The actual effective amounts of a compound can vary according to the specific compound or combination thereof being utilized, the particular composition formulated, the mode of administration, and the age, weight, condition of the individual, and severity of the symptoms or condition being treated.

[0083] The term “pharmaceutically acceptable” refers to compositions or other materials and / or dosage forms which are, within the scope of sound medical judgment, suitable for use in contact with the tissues of human beings and animals without excessive toxicity, irritation, allergic response, or other problem or complication, commensurate with a reasonable benefit / risk ratio. The phrase “pharmaceutically acceptable carrier” refers to pharmaceutically acceptable materials, compositions or vehicles, such as a liquid or solid filler, diluent, solvent or encapsulating material involved in carrying or transporting any subject composition, from one organ, or portion of the body, to another organ, or portion of the body. Each carrier must be “acceptable” in the sense of being compatible with the

[0084] 7

[0085] 45835266.1other ingredients of a subject composition and not injurious to the subject to which it is administered.

[0086] The terms “inhibit” or “reduce” in the context of inhibition, mean to reduce or decrease in activity and quantity. This can be a complete inhibition or reduction in activity or quantity, or a partial inhibition or reduction. Inhibition or reduction can be compared to a control or to a standard level. Inhibition can be measured as a % value, e.g., from 1% up to 100%, such as 5%, 10, 25, 50, 75, 80, 85, 90, 95, 99, or 100%. For example, pharmaceutical compositions including one or more types of active agents may inhibit or reduce one or more markers of a disease or disorder, such as malaria, in a subject by about 10%, 20%, 30%, 40%, 50%, 75%, 85%, 90%, 95%, or 99% from the activity and / or quantity of the same marker in subjects that did not receive or were not treated with the compositions.

[0087] The terms “treating” in the context of a disease or disorder means to ameliorate, reduce or otherwise stop a disease, disorder, or condition from occurring or progressing in an animal which may be predisposed to the disease, disorder and / or condition but has not yet been diagnosed as having it; inhibiting the disease, disorder or condition, e.g., impeding its progress; and relieving the disease, disorder, or condition, e.g., causing regression of the disease, disorder and / or condition. Treating the disease or condition includes ameliorating at least one symptom of the particular disease or condition, even if the underlying pathophysiology is not affected, such as treating the pain of a subject by administration of an analgesic agent even though such agent does not treat the cause of the pain. Desirable effects of treatment include decreasing the rate of disease progression, ameliorating, or palliating the disease state, and remission or improved prognosis. For example, a subject is “treated” if one or more symptoms associated with malaria is mitigated or eliminated, including, but not limited to, increasing the quality of life of those suffering from the malaria, decreasing the dose of other medications required to treat the malaria, delaying the progression of the malaria, and / or prolonging survival of subject(s).

[0088] An “alkyl group” is understood to a chain having 1 to 20 carbon atoms, 1 to 10 carbon atoms, or 1 to 8 carbon atoms. The alkyl radical may be branched or unbranched and the carbon chain may optionally be interrupted by one or more heteroatoms, such as N, O, or S. Heteroatoms may have hydrogen substituents and / or any permissible substituents of organic compounds in order to satisfy the valences of the heteroatoms. The alkyl radical may optionally be substituted by one or more of the substituents 8

[0089] 45835266.1mentioned for the aryl radicals above. It is also possible that the alkyl radical contain one or more aryl groups thereon, where suitable aryl groups are described above. Exemplary alkyl radicals include, without limitation, methyl, ethyl, i-propyl, n-propyl, i-butyl, n-butyl, t-butyl, sec -butyl, i-pentyl, n-pentyl, sec-pentyl, neopentyl, n-hexyl, i-hexyl and sec-hexyl.

[0090] A “cycloalkyl group” is understood to mean a cyclic alkyl having 3 to 20 carbon atoms, 3 to 10 carbon atoms, or 3 to 8 carbon atoms. The carbon chain of the cycloalkyl radical may optionally be interrupted by one or more heteroatoms, such as N, O, or S. Heteroatoms may have hydrogen substituents and / or any permissible substituents of organic compounds in order to satisfy the valences of the heteroatoms. The cycloalkyl radical may be unsubstituted or substituted, i.e. substituted by one or more of the substituents mentioned herein.

[0091] An “aryl group” is understood to refer to a structure made up of 6 to 30 carbon atoms, 6 to 18 carbon atoms, which is formed from one aromatic ring or a plurality of fused aromatic rings. Exemplary aryl radicals are, without limitation, phenyl, naphthyl, anthracenyl, or phenanthrenyl. Aryl radicals may be unsubstituted, where all carbon atoms which are substitutable bear hydrogen atoms. Alternatively, they may be substituted at one, greater than one, or at all substitutable positions therein. Suitable exemplary substituents include, without limitation, alkyl radicals, such as alkyl radicals having 1 to 8 carbon atoms, which may be selected from methyl, ethyl, i-propyl or t-butyl, aryl radicals (such as Ce-aryl radicals, which may be substituted or unsubstituted), heteroaryl radicals (which may comprise at least one nitrogen atom, such as pyridyl radicals), alkenyl radicals (which may comprise one double bond and 1 to 8 carbon atoms), or groups with electron donating or electron accepting ability. Groups with electron donating ability are understood to mean groups which have a positive inductive (+1) and / or positive mesomeric (+M) effect, and groups with electron accepting ability are understood to mean groups which have a negative inductive (-1) and / or negative mesomeric (-M) effect. Suitable groups with donor or acceptor action are halogen radicals, such as F, Cl, Br, alkoxy radicals, aryloxy radicals, carbonyl radicals, ester radicals, amine radicals, amide radicals, CH2F groups, CHF2 groups, CF3 groups, CN groups, thio groups, or SCN groups.

[0092] A “heteroaryl group” is understood to refer to a structure which differs from the aryl group described above in that at least one carbon atom in the structure making up the aryl group is otherwise replaced by at least one heteroatom. Heteroatoms may have 9

[0093] 45835266.1hydrogen substituents and / or any permissible substituents of organic compounds in order to satisfy the valences of the heteroatoms. Exemplary heteroatoms include N, O, and S. In most instances, one or two carbon atoms of the structure of the aryl radicals are replaced by heteroatoms. Exemplary heteroaryls include, without limitation, pyridyl, pyrimidyl, pyrazyl, triazyl, and five-membered heteroaromatics, such as pyrrole, furan, thiophene, pyrazole, imidazole, triazole, oxazole, thiazole. Heteroaryls may be substituted at none (unsubstituted), one, more than one, or at all substitutable positions. Suitable substituents are as defined above for the aryl radicals.

[0094] A ’’benzyl group” or Bn is understood to refer to a structure that can be represented by the general formula:

[0095]

[0096] wherein one or more of the hydrogen atoms be may optionally by substituted by a substituent, as described below.

[0097] The term “substituted,” as used herein, refers to all permissible substituents of the compounds or functional groups described herein. Exemplary substituents include, but are not limited to, halogens, hydroxyl groups, or any other organic groupings containing any number of carbon atoms, preferably 1-14 carbon atoms, and optionally include one or more heteroatoms, such as oxygen, sulfur, or nitrogen grouping in linear, branched, or cyclic structural formats. Representative substituents can include alkyl, substituted alkyl (such as -CF3 and -CD3), cycloalkyl (such C3-C20, C3-C10, or C3-Cs), alkenyl, substituted alkenyl, alkynyl, substituted alkynyl, phenyl, substituted phenyl, aryl, substituted aryl, heteroaryl, substituted heteroaryl, halo, hydroxyl, alkoxy, formyl, substituted alkoxy, phenoxy, substituted phenoxy, aroxy, substituted aroxy, thio (-SH), substituted thio, arylthio, substituted arylthio, cyano, isocyano, substituted isocyano, carbonyl, substituted carbonyl, carboxyl, substituted carboxyl, carboxylates, amino, substituted amino, amide, substituted amide, sulfonyl, substituted sulfonyl, sulfonic acid, phosphoryl, substituted phosphoryl, phosphonyl, substituted phosphonyl, polyaryl, substituted polyaryl, cyclic (such as C3-C20 cyclic), substituted cyclic (such as substituted C3-C20 cyclic), heterocyclic, substituted heterocyclic, deuterium, trihaloalkyl (trifluoromethyl), unsubstituted diarylamino, substituted diarylamino, unsubstituted dialkylamino, substituted dialkylamino, azo, carbonate ester, nitro, nitroso, phosphino, pyridyl, NRR', SR, C(O)R, COOR, C(O)NR, SOR, and SOR groups, wherein R and R' are

[0098] 10

[0099] 45835266.1independently selected from hydrogen atom, deuterium atom, or any of the substituents named above.

[0100] The numerical ranges disclose individually each possible number that such a range could reasonably encompass, as well as any sub-ranges and combinations of subranges encompassed therein. For example, in a given range concentration range of 10 pM to 500 pM, the range also discloses 20, 33, 350, and 499 pM, as well as any subrange between these numbers (for example, 50 pM to 250 pM), and any possible combination of ranges possible between these values.

[0101] Use of the term "about" is intended to describe values either above or below the stated value, which the term “about” modifies, to be within a range of approximately + / -10%. When the term "about" is used before a range of numbers (i.e., about 1-5) or before a series of numbers (i.e., about 1, 2, 3, 4, etc.) it is intended to modify both ends of the range of numbers and / or each of the numbers recited in the entire series, unless specified otherwise.

[0102] IL Reserpine Ring Fusion Analogs

[0103] Described herein are reserpine-derived ring fusion analogs and methods of making thereof. Such reserpine-derived ring fusion analogs can be used as antiplasmodial agents for treating malaria. Various reserpine and reserpate ring fusion analogs are described below.

[0104] In one non-limiting instance, a reserpine ring fusion analog has a structure of Formula I as follows:

[0105] MeO

[0106]

[0107] OMe

[0108] Formula (I)

[0109] 11

[0110] 45835266.1wherein each X is a halogen; and

[0111] wherein R is a substituted or unsubstituted Ci-Ce alkyl, a substituted or unsubstituted C3-C10 cycloalkyl, or a substituted or unsubstituted benzyl group.

[0112] In another non-limiting instance, a reserpate ring fusion analog has a structure of Formula II as follows:

[0113]

[0114] Formula (II)

[0115] wherein each X is a halogen;

[0116] wherein R is a substituted or unsubstituted Ci-Ce alkyl or a substituted or unsubstituted benzyl; and

[0117] wherein R’ is a hydrogen or carboxyl moiety (-C(O)-R”), wherein R” is a substituted or unsubstituted Ci-Ce alkyl, substituted or unsubstituted Cs-Cs cycloalkyl, substituted or unsubstituted C5-C12 aryl group, or substituted or unsubstituted C5-C12 hctcroaryl group.

[0118] In some instances, the halogen (X) is a chlorine for compounds of Formula I and 11. In some other instances, the halogen (X) is a bromine.

[0119] In some instances, R of Formula I is a substituted Ci-Ce alkyl having a halogenated Ci-Ce alkyl (such as -CF3) thereon. In other instances, R of Formula I is an unsubstituted Ci-Ce alkyl, such as a methyl group. In some particular instances, the substituted Ci-Ce alkyl has the following structure:

[0120] y^-cF3.

[0121] In some instances, R of Formula I is a substituted benzyl group and the substituents are selected from a halogen, a Ci-Ce alkoxy (such as -OMe), or a halogenated Ci-Ce alkyl (such as -CF3).

[0122] 12

[0123] 45835266.1In some instances for Formula I, the substituted benzyl group has one of the following structures:

[0124]

[0125] In some instances, R of Formula I is the substituted or unsubstituted benzyl. In some instances, R of Formula I is a substituted or unsubstituted C3-C10 cycloalkyl. In some instances for Formula I, the unsubstituted cycloalkyl group has one of the following structures:

[0126]

[0127] In some instances, R’ of Formula II is the carboxyl moiety (-C(O)-R”), wherein R” is a substituted or unsubstituted Ci-Ce alkyl, substituted or unsubstituted C5-C8 cycloalkyl, substituted or unsubstituted C5-C12 aryl group, or substituted or unsubstituted C5-C12 heteroaryl group.

[0128] In some instances, the R” of the carboxyl moiety of Formula II has one of the structures:

[0129]

[0130] In some particular instances, the reserpate ring fusion analog has one of the following structures:

[0131] 13

[0132] 45835266.1

[0133]

[0134] In some instances, for the various reserpine-derived ring fusion analogs of the Formulae described above, these analogs are produced by methods which are diastereoselective and produce the analogs as a single diastereomer, such as the syn-diastereomer.

[0135] A. Pharmaceutical Compositions

[0136] In some instances, the reserpine ring fusion analogs described herein form part of a pharmaceutical composition. The pharmaceutical composition includes an effective amount of the reserpine ring fusion analog and optionally one or more pharmaceutically acceptable earners and / or excipients.

[0137] In one non-limiting instance, a pharmaceutical composition includes:

[0138] a plurality of the reserpine ring fusion analog; at least one pharmaceutically acceptable carrier; and optionally a pharmaceutically acceptable excipient.

[0139] In some instances, the one or more pharmaceutically acceptable carriers are selected from water, ethanol, polyethylene glycol, propylene glycol, chitosan polymers and chitosan derivatives (e.g. N-trimethylene chloride chitosan, chitosan esters, chitosan modified with hydrophilic groups, such as amino groups, carboxyl groups, sulfate

[0140] 45835266.1groups, etc.), methylcellulose, an oil, and combinations thereof. Other suitable carriers are known.

[0141] The pharmaceutical compositions include an effective amount of the reserpine ring fusion analog to treat a disease or disorder, such as malaria. In some instances, the reserpine ring fusion analog is present in a concentration ranging from about 1 pM to about 1 mM, from about 10 LIM to about 500 pM, from about 10 pM to about 200 pM, or from about 25 pM to about 100 pM of the pharmaceutical composition, as well as individual values and sub-ranges contained within the aforementioned ranges. In some other instances, the reserpine ring fusion analog are present in a concentration ranging from about 1 pM to about 10 mM, from about 1 pM to about 5 mM, from about 10 pM to about 1 mM, or from about 10 pM to about 500 pM of the pharmaceutical composition, as well as individual values and sub-ranges contained within the aforementioned ranges.

[0142] In some instances, depending on the route of administration, an effective amount of the reserpine ring fusion analog in the composition can be between 0.01 to 1000 mg per kilogram body weight of the subject per day, between 0.1 and 500 mg, such as between 1 and 250 mg, for example about 5, 10, 20, 50, 100, 150, 200 or 250 mg, per kilogram body weight of the subject per day, which can be administered as a single daily dose, divided over one or more daily doses. The amount of the reserpine ring fusion analog administered, the route of administration, and the further treatment regimen can be determined by the treating clinician or testing technologies, depending on factors such as the age, gender and general condition of the subject, the nature and severity of the disease / symptoms being prevented, treated, or diagnosed, and / or the samples being tested.

[0143] Pharmaceutical compositions containing a therapeutically effective amount of the reserpine ring fusion analog described, and optionally one or more additional therapeutic, prophylactic, and / or diagnostic agents are also provided. Pharmaceutical compositions can be for administration by parenteral (intramuscular, intraperitoneal, intravenous (IV), or subcutaneous injection), enteral, or transmucosal (intranasal, vaginal, rectal, or sublingual) routes of administration or using bioerodible inserts and can be formulated in dosage forms appropriate for each route of administration.

[0144] i. Parenteral Compositions

[0145] Pharmaceutical compositions containing the reserpine ring fusion analog described can be administered in an aqueous solution, by parenteral injection. Such 15

[0146] 45835266.1compositions may also be in the form of a suspension or emulsion. In general, pharmaceutical compositions are provided including effective amounts of the active agent(s) (i.e., the reserpine ring fusion analog and optionally include pharmaceutically acceptable diluents, preservatives, solubilizers, emulsifiers, adjuvants and / or earners. Such compositions include diluents sterile water, buffered saline of various buffer content (e.g., Tris-HCl, acetate, phosphate), pH and ionic strength; and optionally, additives such as detergents and solubilizing agents (e.g., TWEEN® 20, TWEEN® 80 also referred to as polysorbate 20 or 80), antioxidants (e.g., ascorbic acid, sodium metabisulfite), and preservatives (e.g., Thimersol, benzyl alcohol) and bulking substances (e.g., lactose, mannitol). Examples of non-aqueous solvents or vehicles are propylene glycol, polyethylene glycol, vegetable oils, such as olive oil and com oil, gelatin, and injectable organic esters such as ethyl oleate. The compositions may be lyophilized and redissolved / resuspended immediately before use. The compositions may be sterilized by, for example, filtration through a bacterium retaining filter, by incorporating sterilizing agents into the compositions, by irradiating the compositions, or by heating the compositions.

[0147] These particular aqueous solutions are especially suitable for intranasal or intratracheal administration, such as the respiratory tract. These particular aqueous solutions are also suitable for intravenous, intramuscular, subcutaneous, and intraperitoneal administration. In this connection, sterile aqueous media which can be employed will be known to those of skill in the art in light of the present disclosure. For example, one dosage could be dissolved in 1 ml of isotonic NaCl solution and either added to variation in dosage will necessarily occur depending on the condition of the subject being treated. The person responsible for administration will, in any event, determine the appropriate dose for the individual subject.

[0148] ii. Oral Compositions

[0149] The pharmaceutical composition containing the reserpine ring fusion analog described may be provided in a form suitable for oral administration to a subject in need thereof, such as a mammal (i.e., an oral composition). Oral administration may involve swallowing, so that the reserpine ring fusion analog and optionally additional active agent(s) enter the gastrointestinal tract, or buccal or sublingual administration may be employed by which the reserpine ring fusion analog enter the blood stream directly from the mouth.

[0150] 16

[0151] 45835266.1Compositions suitable for oral administration include solid compositions such as tablets, capsules containing particulates, liquids, powders, lozenges (including liquid-filled lozenges), chews, multi- and nano-particulates, gels, solid solutions, liposomes, films, ovules, sprays, and liquid compositions.

[0152] Liquid compositions for oral administration include suspensions, solutions, syrups, and elixirs. Such oral compositions may be employed as fillers in soft or hard capsules and can contain one or more suitable carriers and / or excipients, for example, water, ethanol, polyethylene glycol, propylene glycol, chitosan polymers and chitosan derivatives (e.g. N-trimethylene chloride chitosan, chitosan esters, chitosan modified with hydrophilic groups, such as amino groups, carboxyl groups, sulfate groups, etc.), methylcellulose, a suitable oil, one or more emulsifying agents, and / or suspending agents. Liquid compositions for oral administration may also be prepared by the reconstitution of a solid, for example, from a sachet.

[0153] For tablet or capsule dosage forms, in addition to the reserpine ring fusion analog described herein, tablets generally contain disintegrants, binders, diluents, surface active agents, lubricants, glidants, antioxidants, colourants, flavoring agents, preservatives, or taste masking agents, or a combination thereof.

[0154] Examples of suitable disintegrants for forming a table or capsule dosage form containing the reserpine ring fusion analog can include, but are not limited to, sodium starch glycolate, sodium carboxymethyl cellulose, calcium carboxymethyl cellulose, croscarmellose sodium, crospovidone, polyvinylpyrrolidone, methyl cellulose, microcrystalline cellulose, lower alkyl-substituted hydroxypropyl cellulose, starch, pregelatinised starch and sodium alginate. Generally, the disintegrant can have a concentration in a range from about 1 wt% to about 25 wt%, from about 5 wt% to about 20 wt% of the tablet or capsule dosage form containing the reserpine ring fusion analog.

[0155] Binders are generally used to impart cohesive qualities to a tablet composition containing the reserpine ring fusion analog. Suitable binders for forming a tablet or capsule formulation can include, but are not limited to, microcrystalline cellulose, gelatin, sugars, polyethylene glycol, natural and synthetic gums, polyvinylpyrrolidone, pregelatinised starch, chitosan polymers and chitosan derivatives (e.g. N-trimethylene chloride chitosan, chitosan esters, chitosan modified with hydrophilic groups, such as amino groups, carboxyl groups, sulfate groups, etc.), hydroxypropyl cellulose, and hydroxypropyl methylcellulose.

[0156] 17

[0157] 45835266.1Suitable diluents for forming a table or capsule composition containing the reserpine ring fusion analog can include, but are not limited to, lactose (as, for example, the monohydrate, spray-dried monohydrate or anhydrous form), chitosan polymers and chitosan derivatives (e.g. N-tri methylene chloride chitosan, chitosan esters, chitosan modified with hydrophilic groups, such as amino groups, carboxyl groups, sulfate groups, etc.), N-sulfonated derivatives of chitosan, quaternarized derivatives of chitosan, carbosyalkylated chitosan, microcrystalline chitosan, mannitol, xylitol, dextrose, sucrose, sorbitol, microcrystalline cellulose, starch and dibasic calcium phosphate dihydrate.

[0158] Tablet or capsule compositions containing the reserpine ring fusion analog may also contain surface active agents, such as sodium lauryl sulfate and polysorbate 80, and glidants such as silicon dioxide and talc, in the coating. When present, surface active agents can have a concentration in a range from about 0.2 wt% to 5 wt% of the tablet or capsule formulation.

[0159] Tablet or capsule compositions containing the reserpine ring fusion analog also generally contain lubricants, such as magnesium stearate, calcium stearate, zinc stearate, sodium stearyl fumarate, and mixtures of magnesium stearate with sodium lauryl sulphate. Lubricants can have a concentration in a range from about 0.25 wt% to 10 wt%, from about 0.5 wt% to about 3 wt% of the tablet or capsule composition.

[0160] Other possible excipients included in a tablet or capsule formulation containing the reserpine ring fusion analog include glidants (e.g. Talc or colloidal anhydrous silica at about 0.1 wt% to about 3 wt% of the table or capsule formulation), antioxidants, colourants, flavouring agents, preservatives, and taste-masking agents. When present, glidants can have a concentration in a range from about 0.2 wt% to 1 wt% of the tablet or capsule composition.

[0161] Tablet or capsule blends, including the reserpine ring fusion analog and one or more suitable excipients, may be compressed directly or by roller to form tablets. Tablet or capsule blends or portions of the blends may alternatively be wet-, dry-, or melt-granulated, melt congealed, or extruded before tableting. The final table or capsule composition may contain one or more layers and may be coated or uncoated; it may even be encapsulated in a particle, such as a polymeric particle or a liposomal particle.

[0162] Solid formulations containing the reserpine ring fusion analog for oral administration may be formulated to be immediate and / or modified release. Modified release formulations include delayed, sustained, pulsed, controlled, targeted and programmed release formulations.

[0163] 18

[0164] 45835266.1iii. Optional Therapeutic, Prophylactic or Diagnostic Agents In some forms, the pharmaceutical compositions can optionally include one or more additional active agents. Therefore, in some forms, the pharmaceutical composition includes the reserpine ring fusion analog, in addition to at least one of a therapeutic, prophylactic, and / or diagnostic agents. The additional active agents can be included together with the reserpine ring fusion analog or may be a separate composition for coadministration.

[0165] Non-limiting examples of therapeutic, prophylactic, or diagnostic agents can include bronchodilators, corticosteroids, methylxanthines, phosphodiesterase-4 inhibitors, anti-angiogenesis agents, antibiotics, antioxidants, anti-viral agents, antifungal agents, anti-inflammatory agents, immunosuppressant agents, anti-allergic agents, and combinations thereof. The amount of any additional therapeutic, prophylactic, or diagnostic agents generally depends on the severity of the diseases and / or disorders to be treated. Specific dosages can be readily determined by those of skill in the art. See Ansel, Howard C. et al., Pharmaceutical Dosage Forms and Drug Delivery Systems (6th ed.) Williams and Wilkins, Malvern, PA (1995).

[0166] iv. Pharmaceutically Acceptable Carriers and Excipients The pharmaceutical compositions may be formulated with one or more excipients and / or carriers appropriate to the indicated route of administration. In some forms, the reserpine ring fusion analog are formulated in a manner amenable for the treatment of human and / or veterinary subjects. In some forms, the pharmaceutical compositions include admixing or combining the reserpine ring fusion analog with one or more of the following excipients: lactose, sucrose, starch powder, cellulose esters of alkanoic acids, cellulose alkyl esters, talc, stearic acid, magnesium stearate, magnesium oxide, sodium and calcium salts of phosphoric and sulfuric acids, gelatin, acacia, sodium alginate, polyvinyl-pyrrolidone, and / or polyvinyl alcohol. In some forms, e.g., for oral administration, the pharmaceutical compositions may be tableted or encapsulated. In some forms, the reserpine ring fusion analog may be slurried in water, polyethylene glycol, propylene glycol, ethanol, corn oil, cottonseed oil, peanut oil, sesame oil, benzyl alcohol, sodium chloride, and / or various buffers. In some forms, the pharmaceutical compositions may be subjected to pharmaceutical operations, such as sterilization, and / or may contain carriers and / or excipients such as preservatives, stabilizers, wetting agents, emulsifiers, encapsulating agents such as lipids, dendrimers, polymers, proteins such as albumin, nucleic acids, and buffers.

[0167] 19

[0168] 45835266.1v. Dosage Forms

[0169] In some forms, it may be advantageous to formulate pharmaceutical compositions in dosage unit form for ease of administration and uniformity of dosage. “Dosage unit form'’ as used herein refers to physically discrete units suited as unitary dosages for the patients to be treated; each unit containing a predetermined quantity of therapeutic agent (i.e., the reserpine ring fusion analog) calculated to produce the desired therapeutic effect in association with a pharmaceutical carrier. In some forms, the specification for the dosage unit forms dictated by and directly dependent on (a) the unique characteristics of the therapeutic agent and the particular therapeutic effect to be achieved, and (b) the limitations inherent in the art of compounding such a therapeutic agent for the treatment of a selected condition in a patient. In some forms, the reserpine ring fusion analog are administered at a therapeutically effective dosage sufficient to treat a condition, such as cancer, associated with a condition in a patient. For example, the efficacy of a pharmaceutical composition containing the reserpine ring fusion analog can be evaluated in an animal model system that may be predictive of efficacy in treating the disease in a human or another animal.

[0170] In some forms, the effective dose range for the therapeutic agent can be extrapolated from effective doses determined in animal studies for a variety of different animals. Precise amounts of the pharmaceutical composition depend on the judgment of the practitioner and are specific to each individual. Other factors affecting the dose include the physical and clinical state of the subject, the route of administration, the intended goal of treatment and the potency, stability, and toxicity of the particular pharmaceutical composition.

[0171] The actual dosage amount of an antibiotic composition of the present disclosure administered to a subject may be determined by physical and physiological factors such as type of animal treated, age, sex, body weight, severity of condition, the type of condition being treated, previous or concurrent therapeutic interventions, idiopathy of the patient and on the route of administration. These factors may be determined by a skilled artisan. The practitioner responsible for administration will typically determine the concentration of active agent(s) in a composition and appropriate dose(s) for the individual subject. The dosage may be adjusted by the individual physician in the event of any complication.

[0172] Single or multiple doses of the active agent(s), such as the reserpine ring fusion analog, are contemplated. Desired time intervals for delivery of multiple doses can be 20

[0173] 45835266.1determined by one of ordinary skill in the art employing no more than routine experimentation. As an example, patients may be administered two doses daily at approximately 12-hour intervals. In some forms, the agent is administered once a day.

[0174] The pharmaceutical composition may be administered on a routine schedule. As used herein, a routine schedule refers to a predetermined designated period of time. The routine schedule may encompass periods of time which are identical, or which differ in length, as long as the schedule is predetermined. For instance, the routine schedule may involve administration twice a day, every day, every two days, every three days, every four days, every five days, every six days, a weekly basis, a monthly basis or any set number of days or weeks there-between. Alternatively, the predetermined routine schedule may involve administration on a twice daily basis for the first week, followed by a daily basis for several months, etc. In other forms, the invention provides that the agent(s) may be taken orally and that the timing of which is or is not dependent upon food intake. Thus, for example, the agent can be taken every morning and / or every evening, regardless of when the patient has eaten or will eat.

[0175] In some forms, the pharmaceutical composition can be in a unit dosage form which can be suitably packaged, for example in a box, blister, vial, bottle, sachet, ampoule or in any other suitable single-dose or multi -dose holder or container (which can be properly labeled): optionally with one or more leaflets containing product information and / or instructions for use. Generally, such unit dosages can contain between 1 and 1000 mg, or between 5 and 500 mg, of the disclosed reserpine ring fusion analog, e.g., about 10, 25, 50, 100, 200, 300 or 400 mg per unit dosage.

[0176] III. Methods of Making Reserpine Ring Fusion Analogs

[0177] The various reserpine-derived ring fusion analogs of Formulae I and II described herein can be prepared according to the non-limiting exemplary synthetic methods described in the Example below and synthetic details shown in the schemes of Figures 3 and 4.

[0178] In one non-limiting instance, a method of synthesizing a reserpine ring fusion analog includes the steps of:

[0179] (i) reacting a mixture of an a-haloamide having a structure of Formula III as follows:

[0180] 21

[0181] 45835266.1

[0182]

[0183] Formula (III)

[0184] wherein each X is a halogen; and

[0185] wherein R is a substituted or unsubstituted Ci-Ce alkyl, a substituted or unsubstituted C3-C13 cycloalkyl, or a substituted or unsubstituted benzyl group;

[0186] a reserpine in an organic solvent, wherein the reserpine has the following structure:

[0187] OMe

[0188] OMe

[0189]

[0190] a base compound to produce the reserpine ring fusion analog, such as of Formula I described above (see also Figure 3).

[0191] In another non-limiting instance, a method of synthesizing a reserpate ring fusion analog includes the steps of:

[0192] (i) reacting a mixture of an a-haloamide having a structure of Formula III as follows:

[0193] X -r N

[0194]

[0195] 1H

[0196] Formula (III)

[0197] wherein each X is a halogen; and

[0198] wherein R is a substituted or unsubstituted Ci-Ce alkyl, a substituted or unsubstituted C3-C13 cycloalkyl, or a substituted or unsubstituted benzyl group;

[0199] a reserpate in an organic solvent, wherein the reserpine has the following structure:

[0200]

[0201] 45835266.1

[0202]

[0203] a base compound to produce the reserpate ring fusion analog, such as of Formula 11 described above.

[0204] In some instances, the base compound is K2CO3. In some instances, the organic solvent is 2,2,2-Trifluoroethanol (TFE). In some instances, step (i) is earned out at or near room temperature (i.e., about 20 to 25 °C). In some instances, step (i) is carried out for a period of time of about 5 to 18 hours or 6 to 16 hours.

[0205] In some instances, R of Formula III is a substituted Ci-Ce alkyl having a halogenated Ci-Ce alkyl (such as -CF3) thereon. In other instances, R of Formula III is an unsubstituted Ci-Ce alkyl, such as a methyl group. In some particular instances, the substituted Ci-Ce alkyl has the following structure:

[0206]

[0207] CF3

[0208] In some instances, R of Formula III is a substituted benzyl group and the substituents are selected from a halogen, a Ci-Ce alkoxy (such as -OMe), or a halogenated Ci-Ce alkyl (such as -CF3). In such instances, R of Formula III can have one of the following structures:

[0209]

[0210] In certain instances, R of Formula III is a substituted or unsubstituted C3-C10 cycloalkyl. In some instances for Formula III, the unsubstituted cycloalkyl group has one of the following structures:

[0211]

[0212] In some instances, the halogen (X) of Formula III is a chlorine or bromine.

[0213] 23

[0214] 45835266.1Typically, the above methods produce a single diastereomer (such as a syn-diastereomer) of the reserpine or reserpate ring fusion analog. In certain instances, the methods may essentially produce a single diastereomer (such as a syn-diastereomer) of the reserpine or reserpate ring fusion analog whereby the product has a diastereomeric excess (d.e.):

[0215] d.e. = (moles of major diastereomer - moles of minor diastereomer) / (moles of major diastereomer + moles of minor diastereomer) x 100

[0216] and the d.e. is 100% or about 99%, 99.1%, 99.2%, 99.3%, 99.4%, 99.5%, 99.6%, 99.7%, 99.8%, 99.9%, or 100% indicating that only one or essentially only diastereomer (i.e., syn-diastereomer) of the analog was produced by the ring fusion methods described.

[0217] Moreover, variants of the reserpate ring fusion analogs are also possible, such as by acylation. For instance, a method of synthesizing a variant of a reserpate ring fusion analog can include the steps of:

[0218] (i1) reacting a mixture of a reserpate fusion analog of Formula IV having the following structure:

[0219]

[0220] Formula (IV)

[0221] wherein each X is a halogen;

[0222] and an acyl chloride having the following structure:

[0223] O

[0224] C

[0225]

[0226] I^R

[0227] wherein R is a substituted or unsubstituted Ci-Ce alkyl, substituted or unsubstituted Cs-Cs cycloalkyl, substituted or unsubstituted C5-C12 aryl group, or substituted or unsubstituted C5-C12 heteroaryl group; wherein the mixture includes at least one base compound. See also Figure 4. The reserpate shown above can be prepared from reserpine by, for example, reacting the 24

[0228] 45835266.1reserpine with a base, such as sodium methoxide in a suitable solvent, such as methanol. See also first step of bottom reaction scheme of Figure 1.

[0229] In some instances, the halogen (X) of Formula IV is a chlorine or bromine. In some instances, the halogen (X) of Formula IV is a chlorine.

[0230] In some instances, the at least one base compound is pyridine, which may act as a solvent, and the reaction is optionally carried out at or near room temperature (i.e., about 20 to 25 °C) for a period of time of about 24 to 48 hours.

[0231] In some instances, the mixture further comprises an organic solvent (such as dichloromethane) .

[0232] In some instances, the at least one base compound is an amine base, such as triethanolamine (TEA).

[0233] In some instances, the mixture further comprises 4-dimethylamino pyridine (DMAP).

[0234] In some instances, the above method is carried out at or near room temperature (i.e., about 20 to 25 °C). In some instances, the method is earned out for a period of time about 12 to 24 hours.

[0235] In some instances, for any of the above methods, there is a further step of dehalogenation to convert the halogens X and optionally convert “-OBn” moiety on the amide nitrogen of the analog product produced into hydrogens. This can be performed, for example, by reacting the analog with nickel chloride (NiCh) and sodium borohydride (NaBFU) in excess in a solvent, such as methanol, at room temperature. See, for instance, Figure 1. Such products, as produced thereof, are also disclosed herein as analogs and can also be used in the treatment methods described.

[0236] Without limitation, the synthetic conditions (i.e., choice of solvent(s), temperatures (such as to achieve refluxing), atmospheres, work-up conditions, purification conditions, etc.) can be varied or modified from those discussed and exemplified herein, as appropriate, by the person of ordinary skill in the art of synthetic chemistry, without impacting the synthesis. The methods may include additional steps, which are not otherwise specified, that may be involved in the syntheses which include, but are not limited to, precipitation of a product, washing the reaction mixture, extracting the reaction mixture, separation of the product from a mixture (e.g., by filtration), drying the product, and combinations thereof. Further processing steps that may be involved include stirring, heating and / or cooling the reaction mixture. Intermediate, crude, and purified products can be characterized using any suitable characterization method known 25

[0237] 45835266.1to the skilled person. In some instances, such methods include, but are not limited to, ’ll and13C NMR, mass spectrometry, elemental analysis, or other techniques.

[0238] IV. Methods of Using Reserpine Ring Fusion Analogs and Pharmaceutical Compositions Thereof

[0239] The reserpine-derived ring fusion analogs of Formulae I and II, described herein, can be used for medical applications, such as to treat malaria in a subject. For example, as demonstrated in the non-limiting Examples, reserpine-derived ring fusion analogs of Formulae I and II, are capable of preventing progression of Plasmodium parasites beyond the trophozoite stage, thereby inhibiting schizogony and subsequent reinvasion of red blood cells, as evidenced by diminished parasitemia, disrupted parasite morphology, and the absence of new ring-stage parasites following treatment with the reserpine derived ring fusion analogs (see Figure 5).

[0240] Furthermore, as demonstrated in the non-limiting Examples, the reserpine-derived ring fusion analogs described herein can have one or more appropriate antiplasmodial properties for the treatment of malaria, such as suitable EC.so concentrations for inhibition of Plasmodium parasites (e.g., between 0.05 pM to about 5 pM), selectivity index between parasite and host cells (e.g., between about 10 to about 600), and / or parasite clearance time (e.g., between about 45 to about 60 hours). Table 1 below lists antiplasmodial properties for reserpine-derived ring fusion analogs capable of treating malaria in a subject in need thereof.

[0241] Therefore, methods of using the reserpine-derived ring fusion analogs for reducing or preventing one or more symptoms of Plasmodium parasitic infection in a subject in need thereof are provided. Typically, the methods exploit the demonstrated anti-malarial efficacy of the described reserpine-derived ring fusion analogs, by administering one or more of the reserpine-derived ring fusion analogs to a subject in need of anti-malarial treatment (e.g., therapeutic or prophylactic anti-malarial treatment).

[0242] In one non- limiting instance, a method of treating a disease or condition associated with infection by a Plasmodium parasite in a subject in need thereof, the method including the steps of:

[0243] (a) administering the pharmaceutical composition containing a reserpine and / or reserpate ring fusion analog (of Formulae I or II) to the subject;

[0244] wherein the pharmaceutical composition has a concentration of the reserpine and / or reserpate ring fusion analog in a therapeutically effective or prophylactically

[0245] 26

[0246] 45835266.1effective amount to reduce one or more symptoms associated with infection by the Plasmodium parasite.

[0247] In one exemplary form, the methods can be used to treat malaria in a subject in need thereof. Such a method can include administering the pharmaceutical composition containing a reserpine and / or reserpate ring fusion analog (of Formulae I or II) to the subject in a therapeutically effective amount to provide an antimalarial effect.

[0248] “Antimalarial effect,” refers to the ability of the reserpine and / or reserpate ring fusion analog in the pharmaceutical composition administered to inhibit, kill, or prevent the growth and replication of Plasmodium parasites, which cause malaria. Thus, the reserpine and / or reserpate ring fusion analogs act as antiplasmodial agents against Plasmodium parasites.

[0249] Any of the described methods of treatment of a subject can include a control. For example, in some forms, the efficacy of the methods can be assessed by comparison with a suitable control subject, such as a diseased or healthy subject in the absence of treatment, or having received a different treatment.

[0250] In the blood, Plasmodium parasites (e.g., P. falciparum) undergo cycles of asexual replication. After invasion of a red blood cell, they develop from ring stages to trophozoites and then to schizonts. Mature schizonts burst to release merozoites that initiate another replication cycle. Post-invasion refers to the period following the entry of a Plasmodium merozoite into a red blood cell (RBC), marking the beginning of the parasite’s intraerythrocytic developmental cycle (IDC). During this cycle, the parasite progresses through several stages: the early ring stage, where it initiates metabolic activity; the trophozoite stage, where it digests hemoglobin and grows; and the schizont stage, where it undergoes nuclear division to form multiple daughter merozoites. 'Phis maturation process typically spans approximately 48 hours, after which the infected RBC ruptures and releases newly formed merozoites into the bloodstream. Re-invasion occurs immediately after this rupture, when the released merozoites invade fresh, uninfected red blood cells, thereby initiating a new replication cycle. This step is important for the parasite’s survival and propagation, as it maintains and amplifies the level of parasitemia in the host.

[0251] Therefore, in some forms, a disclosed composition is administered to a subject in need thereof in an effective amount to reduce the number of Plasmodium ring stages, or trophozoites and / or schizonts within the body of a subject. On other forms, a disclosed

[0252] 27

[0253] 45835266.1composition is administered to a subject in need thereof in an effective amount to inhibit or reduce the asexual blood stages of Plasmodium within the body of a subject.

[0254] In some forms, the pharmaceutical composition is administered within 40 hours post-invasion of red blood cells by the Plasmodium parasite, optionally within 30 hours post-invasion of the Plasmodium parasite. Administering the composition during this window corresponds to the trophozoite and early schizont stages of the Plasmodium intraerythrocytic life cycle, a period in which the parasite is actively metabolizing hemoglobin and undergoing nuclear division. Administration during this phase allows the active compound, such as a reserpine -derived ring fusion analog, to interfere with parasite maturation, replication, or intracellular processing prior to reinvasion. As demonstrated in the Examples, treatment at or before 40 hours post-invasion has been shown to reduce parasitemia and inhibit reinvasion at approximately 54 hours postinvasion, indicating that administration of the pharmaceutical composition can effectively disrupt the parasite's ability to complete schizogony and initiate a new replication cycle.

[0255] In some embodiments, the administration of the composition alternatively or additionally prevents an infection of Plasmodium in a subject that does not have malaria. For example, in some forms, the pharmaceutical composition including one or more of the reserpine-derived ring fusion analogs of Formulae I and II is administered as a prophylactic, for example, to confer resistance in a subject to subsequent exposure to infectious agents.

[0256] 1. Selecting a Subject / Control

[0257] Any of the described methods can include one or more steps of selecting a subject. A subject in need of treatment is a subject having or at risk of having an infection e.g., a subject having or at risk of contracting Plasmodium infection.

[0258] The methods are particularly suited for those at risk of exposure to one or more pathogens such as Plasmodium falciparum. Thus, in some forms, the subject has not experienced any symptoms from Plasmodium infection, but is at risk of doing so.

[0259] Typically, the subject is a mammal, such as a human. In some forms, the subject has one or more symptoms of a Plasmodium infection. For example, in some forms, the subject is infected with a Plasmodium parasite such as Plasmodium falciparum, Plasmodium vivax, Plasmodium malariae, Plasmodium ovale curtisi, Plasmodium ovale wallikeri, Plasmodium knowlesi or Plasmodium simium. In exemplary forms, the subject is infected with Plasmodium falciparum. In some forms, the subject is infected with a 28

[0260] 45835266.1Plasmodium parasite that is resistant to one or more forms of pre-existing anti-microbial (e.g., anti-malarial) treatments. For example, in some forms, the subject is infected with a Plasmodium parasite that is a chloroquine resistant Plasmodium parasite, such as a chloroquine resistant Plasmodium falciparum.

[0261] An exemplary method to identify infection with a Plasmodium parasite such as Plasmodium falciparum, includes microscopic examination of blood films, and / or a Rapid Diagnostic Test (RDT), and / or Polymerase Chain Reaction (PCR) based diagnostic methods. In some forms, an infected subject may show signs of infection with a. Plasmodium parasite (e.g., Plasmodium falciparum), such as parasitemia or detectable levels of Plasmodium DNA or antigens but exhibit no symptoms of disease. For example, the subject may have asymptomatic parasitemia that is identified through blood smear microscopy, rapid diagnostic tests, or molecular methods like PCR, despite the absence of clinical symptoms such as fever, chills, or malaise.

[0262] In other forms, a subject has one or more symptoms of malaria and is administered a therapeutically effective amount of a pharmaceutical composition containing one or more of the reserpine-derived ring fusion analogs of Formulae I and II to reduce parasitemia, alleviate symptoms, and / or prevent disease progression.

[0263] Parasitemia refers to the presence of parasites in the bloodstream and is commonly used as a clinical indicator in infections such as malaria. In the case of malaria, parasitemia denotes the presence of Plasmodium parasites, such as P. falciparum, within red blood cells. It is typically quantified either as the percentage of infected red blood cells or as the number of parasites per microliter of blood.

[0264] Malaria infection begins when an infected mosquito bites a human host, introducing Plasmodium sporozoites into the bloodstream. Of the four Plasmodium species that infect humans, P. falciparum is the most virulent, often leading to severe anemia and cerebral malaria — both of which can be fatal. Typically, fewer than 200 sporozoites are introduced during a bite, and only a small fraction successfully invade liver cells, which are the initial target for parasite development. Once inside the liver, the parasite undergoes rapid replication, and within a few days, thousands of merozoites are released into the bloodstream. These merozoites invade red blood cells (RBCs), marking the onset of the symptomatic phase of malaria. Inside RBCs, the parasite multiplies quickly, producing approximately 28 to 32 daughter parasites in less than 48 hours. Red blood cells are composed of about 95% hemoglobin, which the parasite digests to obtain essential amino acids. During this process, however, the breakdown of hemoglobin 29

[0265] 45835266.1releases free heme — a molecule that, in its unbound form, is highly toxic to the parasite. To survive, the parasite detoxifies free heme by converting it into a non-toxic, crystalline form known as hemozoin, which is chemically identical to P-hematin.

[0266] Exemplary symptoms of malaria include fever, chills, headache, fatigue, nausea and vomiting, tachycardia, pain, cough, diarrhea, pulmonary edema, seizures, kidney injury, coma, brain damage, organ failure, anemia, acute respiratory distress syndrome (ARBs), circulatory collapse / shock, disseminated intravascular coagulation, acidosis, jaundice and hypoglycemia. Another sign or symptom of malaria includes identification of a Plasmodium infection in the subject.

[0267] In some forms, the subject is not infected with a Plasmodium parasite. In some forms, the subject is seronegative for a Plasmodium parasite (e.g., P. falciparum). In some forms, the subject does not have malaria. In some forms, the subject is at risk of contracting malaria, and / or has been identified as having a health condition that predisposes the subject to potential complications of malarial infection. Therefore, in some forms, the methods administer a pharmaceutical composition containing one or more of the reserpine-derived ring fusion analogs of Formulae I and II to a subject as a prophylactic treatment, for example, to prevent infection with a Plasmodium parasite. For example, in some forms, the methods administer pharmaceutical composition containing one or more of the reserpine-derived ring fusion analogs of Formulae I and II to a subject that does not have malaria to prevent the subject from contracting malaria.

[0268] In some forms, the prophylactic dose and / or treatment regimen of one or more of the reserpine-derived ring fusion analogs of Formulae I and II are the same as the therapeutic dose or treatment regimen. In other forms, the prophylactic dose and / or treatment regimen of one or more of the reserpine-derived ring fusion analogs of Formulae I and II is different to the therapeutic dose or treatment regimen.

[0269] In some forms, the subject has been in close contact with a vector, such as a mosquito that may carry or transmit a Plasmodium parasite. Such a subject may or may not be exhibiting one or more symptoms of an infection. In some forms, the subject of the treatment is identified by being potentially exposed to a vector, such as a mosquito that may cany or transmit a Plasmodium parasite. For example, in some forms, a subject is selected based on travel to a geographical location that is known to be associated with malaria infection, such as the Democratic Republic of Congo, Nigeria, and India.

[0270] In some forms, the subject does not have parasitic infection and does not have sickle cell disease. Typically, the subject does not have sickle-cell disease, or does not 30

[0271] 45835266.1have one or more of the symptoms of sickle cell disease. In some forms, the subject does not have a disease or disorder associated with glucose-6-phosphate dehydrogenase enzyme deficiency (G6PD deficiency). In some forms, the subject does not have a gene encoding a mutated hemoglobin protein. For example, in some forms, the subject does not carry a single S hemoglobin mutation, or a double S hemoglobin mutation or a mutation causing hemoglobin C.

[0272] Subjects can be male and / or female, adults (e.g., 18 or over), and / or children under 18. In some forms, the subject is a human child aged less than 12 years old. In other forms, the subject is a pregnant woman. In some forms, the subject has an underlying condition such as asthma, heart disease, diabetes, cancer, chronic lung disease, chronic heart disease, chronic kidney disease, or a combination thereof. In some forms, the subject is immunocompromised. In some forms, the subject is infected with human immunodeficiency virus (HIV).

[0273] 2. Dosages and Modes of Administration

[0274] The reserpine-derived ring fusion analogs of Formulae 1 and II can be formulated in a dosage form appropriate for each route of administration. For example, administration can be local or systemic. In some forms, the described reserpine-derived ring fusion analogs of Formulae I and II and pharmaceutical compositions thereof are administered via any route of administration, for example, via oral, parenteral (intramuscular, intraperitoneal, intravenous (IV) or subcutaneous injection), transdermal (either passively or using iontophoresis or electroporation), or transmucosal (nasal or sublingual) routes of administration, or using bioerodible inserts. The precise dosage will vary according to a variety of factors including, but not limited to, the reserpine-derived ring fusion analog that is selected, and subject-dependent variables (e.g., age, immune system health, clinical symptoms, etc.).

[0275] In some forms, the methods administer a dosage of one or more of the described reserpine-derived ring fusion analogs in an amount from about 10 mg to about 3,000 mg, inclusive. In an exemplary form the dosage is administered in an amount between about 10 mg to about 3,000 mg, inclusive, such as 10 mg, 100 mg, 200 mg, 300 mg, 400 mg, 500 mg, 600 mg, 700 mg, 800 mg, 900 mg, 1,000 mg, 1,100 mg, 1,200 mg, 1,300 mg, 1,400 mg, 1,500 mg, 1,600 mg, 1,700 mg, 1,800 mg, 1,900 mg, 2,000 mg, 2,100 mg, 2,200 mg, 2,300 mg, 2,400 mg, 2,500 mg, 2,600 mg, 2,700 mg, 2,800 mg, 2,900 mg, or 3,000 mg.

[0276] 31

[0277] 45835266.1In some forms, the methods administer a dosage of one or more of the described reserpine-derived ring fusion analogs including a therapeutically effective amount for treating or preventing a sign or symptom of malaria in a subject that is determined according to the body weight of the subject. For example, in some forms, the methods administer one or more of the described reserpine-derived ring fusion analogs at a dosage within the range of about 0.001 mg per kilogram of body weight of the recipient to about 5 mg per kilogram of body weight, inclusive, for example, about 0.001 mg to about 5 mg per kilogram of body weight, about 0.001 mg to about 10 mg per kilogram of body weight, about 0.001 mg to about 20 mg per kilogram of body weight, about 0.001 mg to about 50 mg per kilogram of body weight, about 0.001 mg to about 100 mg per kilogram of body weight, about 0.001 mg to about 200 mg per kilogram of body weight, or about 0.001 mg to about 300 mg per kilogram of body weight.

[0278] In some forms, the methods administer the composition as a long-term treatment regimen, for example, to impart pharmacokinetic steady state conditions.

[0279] Administration(s) of the described reserpine-derived ring fusion analogs and pharmaceutical compositions thereof can be repeated as often and as many times as a subject can tolerate without toxicity until the desired response is achieved. Thus, the described reserpine-derived ring fusion analogs thereof can also be administered once or multiple times at one or more dosages. The optimal dosage and treatment regime for a particular subject can be determined by one skilled in the art of medicine by monitoring the subject for signs of disease and adjusting the treatment accordingly.

[0280] Treatment can be continued for an amount of time sufficient to achieve one or more desired therapeutic goals. The timing of the administration of the composition will also depend on the formulation and / or route of administration used. The reserpine-derived ring fusion analogs can be administered once daily, but may also be administered two, three or four times daily, or every other day, or once or twice per week. For example, the subject can be administered one or more treatments 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, I I, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, or 24 hours, days, weeks, or months apart.

[0281] In some forms, the pharmaceutical composition containing a reserpine-derived ring fusion analog is administered at a concentration effective to reduce or inhibit the reinvasion of Plasmodium parasites into red blood cells during a window important for the parasite’s intraerythrocytic developmental cycle (IDC). In some forms, administration occurs prior to the onset of schizogony, for example, between about 24

[0282] 32

[0283] 45835266.1and 40 hours post-invasion, to prevent completion of nuclear division and subsequent merozoite release. In some forms, the composition is administered earlier, between about 1 to about 30 hours post-invasion, between about 6 and about 24 hours post-invasion, between about 6 hours and about 15 hours post-invasion, to disrupt parasite metabolism and maturation during early trophozoite stages. In other forms, the composition can be administered prophylactically, prior to infection with Plasmodium parasites, to reduce the likelihood of successful invasion or replication following exposure. The reduction in reinvasion may be evidenced by a decrease in the number of newly infected red blood cells at the next erythrocytic cycle (e.g., at 54 hours post-invasion) compared to an untreated infected subject or the same subject prior to treatment, as determined by microscopy, flow cytometry, or molecular diagnostic assays.

[0284] In some forms, the compositions are formulated for extended release. For example, the formulation can be suitable for administration once daily or less. In some forms, the composition is only administered to the subject once every 24-48 hours.

[0285] Treatment can be continued for a desired period of time, and the progression of treatment can be. In some forms, administration is carried out every day of treatment, or every week, or every fraction of a week. In some forms, treatment regimens are carried out over the course of up to two, three, four or five days, weeks, or months, or for up to 6 months, or for more than 6 months, for example, up to one year, two years, three years, or up to five years.

[0286] In some forms, the pharmaceutical composition is administered in an amount effective to achieve a desired therapeutic effect in the subject. The appropriate dosage of the pharmaceutical composition can vary depending on several factors, including the nature of the active agent, the species, age, weight, and general health of the subject, the severity of the Plasmodium infection, the severity of the malarial disease, and the selected mode of administration. Because of these variables, it is not possible to specify a universally applicable dosage. However, an effective amount can be readily determined by one of ordinary skill in the art using routine experimentation and the guidance provided herein.

[0287] Preferably, the dosage is not so large as to cause adverse side effects, such as unwanted cross-reactions, anaphylactic reactions, and the like. Generally, the dosage will vary with the age, condition, and sex of the patient, route of administration, whether other drugs are included in the regimen, and the type, stage, and location of the disease to be treated. The dosage can be adjusted by the individual physician in the event of any 33

[0288] 45835266.1counter-indications. It will also be appreciated that the effective dosage of the composition can increase or decrease over the course of a particular treatment. Changes in dosage can result and become apparent from the results of diagnostic assays.

[0289] The efficacy of administering a particular dose of the pharmaceutical composition can be determined by evaluating relevant aspects of the subject’s medical history, clinical signs and symptoms, and objective laboratory tests commonly used to assess the status of individuals affected by the disease or condition being treated. The specific clinical indicators and diagnostic tests will vary depending on the nature of the disease or condition — for example, in the case of Plasmodium infection, efficacy may be assessed by monitoring changes in parasitemia levels via blood smear or PCR, reduction in fever, resolution of anemia, or improvements in liver and kidney function markers. Such evaluations can be performed by a clinician experienced in managing malaria or by a researcher conducting standard experimental protocols in the field.

[0290] 3. Effective Amounts

[0291] The amount of the reserpine-derived ring fusion analogs, or pharmaceutical compositions thereof, can be effective to, for example, reduce parasite replication, alleviate one or more symptoms of a disease, disorder, or illness associated with a Plasmodium infection, or achieve a combination of these effects, as compared to the condition of the same subject prior to treatment or to a control subject who did not receive the pharmaceutical composition. The symptoms can include clinical manifestations such as fever, chills, fatigue, or anemia, as well as molecular or cellular markers of infection, including elevated levels of parasitemia, detectable Plasmodium antigens or DNA, or increased inflammatory markers.

[0292] In some forms, treatment using the described reserpine-derived ring fusion analogs can completely prevent colonization and replication of an infectious agent, affecting “sterile immunity” and the absence of any disease symptoms. In some forms, the reserpine-derived ring fusion analogs are effective to reduce the number, severity or duration of symptoms or may alleviate symptoms of a Plasmodium infection or reduce at least one symptom thereof in a subject, (e.g., malaria in a human). The subject can be administered the reserpine-derived ring fusion analogs in a dosage and for a duration sufficient to improve one or more clinical and / or systemic symptoms of a Plasmodium infection or malarial disease. For example, in some forms, the methods include administering an effective amount of the reserpine-derived ring fusion analogs to reduce one or more clinical symptoms of malaria — such as fever, chills, headache, fatigue,

[0293] 34

[0294] 45835266.1nausea and vomiting, tachycardia, pain, cough, diarrhea, pulmonary edema, seizures, kidney injury, coma, brain damage, organ failure, anemia, acute respiratory distress syndrome (ARDS), circulatory collapse or shock, disseminated intravascular coagulation, acidosis jaundice, or hypoglycemia — as compared to the severity or presence of the clinical symptoms in the same subject prior to treatment, or in a comparable subject who did not receive the treatment.

[0295] The reserpine-derived ring fusion analogs, or pharmaceutical compositions thereof can be effective, administered to a subject in need thereof, to reduce one or more cellular and / or molecular markers associated with Plasmodium infection or malarial disease. For example, the reserpine-derived ring fusion analogs and pharmaceutical composition thereof, are effective to decrease the levels of parasitemia as determined by microscopic analysis of Giemsa-stained blood smears, including thick and / or thin smears, compared to the parasitemia levels observed in the same subject prior to treatment or in a comparable subject who was not administered the pharmaceutical composition. Thick smears may be used for increased sensitivity in detecting low parasite densities, while thin smears allow for quantification and identification of a specific Plasmodium species and / or specific developmental stages. In some forms, the reserpine-derived ring fusion analogs, or pharmaceutical compositions thereof, are effective in reducing the number of Plasmodium-infected red blood cells in a biological sample, as measured by flow cytometry, compared to the number of infected red blood cells in the same subject prior to treatment or in a subject who was not administered the pharmaceutical composition. In some forms, the reserpine-derived ring fusion analogs, or pharmaceutical compositions thereof, are effective in reducing the levels of Plasmodium antigens and / or Plasmodium DNA in a biological sample, as measured by molecular methods such as polymerase chain reaction (PCR), compared to the levels detected in the same subject prior to treatment or in a subject who was not administered the pharmaceutical composition. A measurable decrease in parasitemia following administration of the pharmaceutical composition indicates therapeutic efficacy and can be further supported by accompanying improvements in clinical symptoms or other laboratory indicators of infection severity e.g., a decrease chills, jaundice, acute respiratory distress syndrome (ARDs), and / or fatigue.

[0296] In some forms, a pharmaceutical composition containing one or more reserpinederived ring fusion analogs of Formulae I and II is administered in an effective amount to prevent infection with a Plasmodium parasite, such as P. falciparum. The composition 35

[0297] 45835266.1can be used as a prophylactic treatment, for example, to reduce the risk of contracting malaria in individuals who are seronegative, not currently infected, or at elevated risk of exposure due to environmental or health-related factors. The effective prophylactic amount can be determined based on routine clinical or experimental protocols and is sufficient to prevent colonization, replication, or symptom onset associated with Plasmodium infection.

[0298] In some forms, the prophylactic dose and / or treatment regimen of one or more of the reserpine-derived ring fusion analogs is the same as the dose used for therapeutic treatment of active malaria. In other forms, the effective prophylactic amount differs from the therapeutic dose and may be adjusted to account for factors such as frequency of exposure, subject health status, or intended duration of protection. The appropriate effective amount can be identified by one of ordinary skill in the art through routine dosing studies and pharmacokinetic analyses.

[0299] 4. Additional Active Agents

[0300] In some forms, the reserpine-derived ring fusion analogs and / or pharmaceutical compositions thereof, is administered in combination with another active agent.

[0301] Exemplary additional active agents that can be administered to a subject together with one or more of the compositions include one or more additional therapeutic, prophylactic, diagnostic or nutraceutical active agent(s). In exemplary forms, the one or more active agent(s) is selected from, but not limited to, antimicrobial agents, vaccines, anesthetic agents, and anti-inflammatory agents.

[0302] In some forms, the additional active agent(s) is for treatment of the Plasmodium infection or disease (e.g., malaria). In some forms, the additional active agent targets the same or different aspect of the Plasmodium parasite, or its life cycle. For example, in some forms, the described compositions is administered in combination with one or more additional anti-malarial drugs, such as but not limited to, Atovaquone / Proguanil (Malarone), Chloroquine, Doxycycline, Mefloquine, Primaquine, Tafenoquine (ArakodaTM), quinine, or a combination thereof. In some forms, the one or more additional active agent(s) is an anti-malarial antimicrobial agent selected from but not limited to, quinolines, antifolates, and artemisinin derivatives. Exemplary additional anti-malarial antimicrobial agents that are administered to a subject together with one or more of the described compositions include but are not limited to, Atovaquone / Proguanil (Malarone), Chloroquine, Hydroxychloroquine, Doxycycline, Mefloquine, Primaquine, artesunate, Tafenoquine (ArakodaTM), quinine, and Artemether / lumefantrine, or a 36

[0303] 45835266.1combination thereof. Administration of an additional active agent to the subject can be prior to, concurrent with, or subsequent to administration of the described small molecule antimalarial agents to the same subject.

[0304] 5. Exemplary Methods for Treating Malaria

[0305] In exemplary forms, the methods administer to a subject having one or more symptoms or signs of malaria a reserpine-derived ring fusion analog in a pharmaceutical composition for administration in vivo in an amount effective for treating or preventing one or more symptoms or signs of an infection by a Plasmodium parasite or a disease associated with infection by a Plasmodium parasite (e.g., malaria) in the subject. For example in some forms, the methods administer to a subject having one or more symptoms or signs of malaria a dosage of the reserpine-derived ring fusion analog(s) and / or pharmaceutical composition(s) thereof effective for treating or preventing one or more symptoms or signs of malaria in the subject. In some forms, the methods administer the reserpine-derived ring fusion analog(s) and / or pharmaceutical composition(s) thereof to the subject in an amount of about 200 mg to about 3,000 mg, inclusive, per day, for a period of one day, or two, three, four, five, six, or seven days, or more than seven days, such as one month, or two, three, four, five, or six, or months, or more than six months, up to one year. In some forms, the methods administer the reserpine-derived ring fusion analog(s) and / or pharmaceutical composition(s) thereof to the subject via oral administration.

[0306] In some forms, the reserpine-derived ring fusion analog(s) and / or pharmaceutical composition(s) thereof is administered in a dose including an amount effective to clear / kill a specific number of parasites within a host, such as a human. For example, in some forms, the reserpine-derived ring fusion analog(s) and / or pharmaceutical composition(s) thereof is administered to a human subject with malaria in an amount effective to clear or kill at least lOxlO12plasmodium parasites within the host. In other forms, the reserpine-derived ring fusion analog(s) and / or pharmaceutical composition(s) thereof is administered in a dose including an amount effective to provide an in vivo depot to prevent the infection and / or persistence of plasmodium parasites within a host, such as a human. For example, in some forms, the reserpine-derived ring fusion analog(s) and / or pharmaceutical composition(s) thereof is administered to a human subject without malaria in an amount effective to provide a depot that prevents infection or re-infection of the subject for a period of more than one week, for example, for at least

[0307] 37

[0308] 45835266.11 week, 2 weeks, 3 weeks, 4 weeks, 5 weeks, 6 weeks, 7 weeks, 8 weeks, 9 weeks, 10 weeks or longer than 10 weeks.

[0309] The disclosure will be beter understood by reference to the following examples. The methods, compounds, and compositions herein described are further illustrated in the following examples, which are provided by way of illustration and are not intended to be limiting. It will be appreciated that variations in proportions and alternatives in elements of the components shown will be apparent to those skilled in the art and are within the scope of disclosed forms. All parts or amounts, unless otherwise specified, are by weight.

[0310] The disclosed compositions, as well as methods of making and using thereof, can be further understood by reference to the following numbered paragraphs:

[0311] Paragraph 1. A reserpine ring fusion analog having a structure of Formula I as follows:

[0312]

[0313] Formula (I)

[0314] wherein each X is a halogen; and

[0315] wherein R is a substituted or unsubstituted Ci-Ce alkyl, a substituted or unsubstituted C3-C10 cycloalkyl, or a substituted or unsubstituted benzyl group.

[0316] 38

[0317] 45835266.1Paragraph 2. A reserpate ring fusion analog having a structure of Formula II as follows:

[0318]

[0319] Formula (II)

[0320] wherein each X is a halogen;

[0321] wherein R is a substituted or unsubstituted Ci-Ce alkyl, a substituted or unsubstituted C3-C10 cycloalkyl, or a substituted or unsubstituted benzyl; and wherein R’ is a hydrogen or carboxyl moiety (-C(O)-R”), wherein R” is a substituted or unsubstituted Ci-Ce alkyl, substituted or unsubstituted Cs-Cs cycloalkyl, substituted or unsubstituted C5-C12 aryl group, or substituted or unsubstituted C5-C12 heteroaryl group.

[0322] Paragraph 3. The analog of any one of paragraphs 1-2, wherein the halogen is a chlorine.

[0323] Paragraph 4. The analog of any one of paragraphs 1-2, wherein the halogen is a bromine.

[0324] Paragraph 5. The analog of paragraph 1, wherein R is a substituted Ci-Ce alkyl having a halogenated Ci-Ce alkyl (such as -CF3) thereon.

[0325] Paragraph 6. The analog of paragraph 5, wherein the substituted Ci-Ce alkyl has the following structure:

[0326]

[0327] Paragraph 7. The analog of paragraph 1, wherein R is a substituted benzyl group and the substituents are selected from the group consisting of a halogen, a Ci-Ce alkoxy (such as -OMe), and a halogenated Ci-Ce alkyl (such as -CF3).

[0328] 45835266.1Paragraph 8. The analog of paragraph 7, wherein the substituted benzyl group has one of the following structures:

[0329]

[0330] Paragraph 9. The analog of paragraph 1, wherein R is the substituted or unsubstituted C3-C10 cycloalkyl.

[0331] Paragraph 10. The analog of paragraph 9, wherein the unsubstituted C3-C10 cycloalkyl has one of the following structures:

[0332]

[0333] Paragraph 11. The analog of paragraph 2, wherein R is the substituted or unsubstituted benzyl.

[0334] Paragraph 12. The analog of paragraph 2, wherein R’ is the carboxyl moiety (-C(O)-R”), wherein R” is a substituted or unsubstituted Ci-Ce alkyl, substituted or unsubstituted C5-C8 cycloalkyl, substituted or unsubstituted C5-C12 aryl group, or substituted or unsubstituted C5-C12 heteroaryl group.

[0335] Paragraph 13. The analog of paragraph 12, wherein the R” of the carboxyl moiety has one of the structures:

[0336]

[0337] ; or Me

[0338] Paragraph 14. The analog of any one of paragraphs 1-12, wherein the reserpine ring fusion analog is a single diastereomer (such as a syn-diastereomer).

[0339] Paragraph 15. A method of synthesizing a reserpine ring fusion analog comprising the steps of:

[0340] (i) reacting a mixture of an a-haloamidc having a structure of Formula III as follows:

[0341] 45835266.1

[0342]

[0343] Formula (III)

[0344] wherein each X is a halogen; and

[0345] wherein R is a substituted or unsubstituted Ci-Ce alkyl, a substituted or unsubstituted C3-C13 cycloalkyl, or a substituted or unsubstituted benzyl group;

[0346] a reserpine in an organic solvent, wherein the reserpine has the following structure:

[0347]

[0348] ; and

[0349] a base compound to produce the reserpine ring fusion analog.

[0350] Paragraph 16. A method of synthesizing a reserpate ring fusion analog comprising the steps of:

[0351] (i) reacting a mixture of an a-haloamide having a structure of Formula III as follows:

[0352]

[0353] Formula (III)

[0354] wherein each X is a halogen; and

[0355] wherein R is a substituted or unsubstituted Ci-Ce alkyl, a substituted or unsubstituted C3-C10 cycloalkyl, or a substituted or unsubstituted benzyl group;

[0356] a reserpate in an organic solvent, wherein the reserpine has the following structure:

[0357] 41

[0358] 45835266.1

[0359]

[0360] a base compound to produce the reserpate ring fusion analog.

[0361] Paragraph 17. The method of any one of paragraphs 15-16, wherein the base compound is K2CO3.

[0362] Paragraph 18. The method of any one of paragraphs 15-17, wherein the organic solvent is 2,2,2-Trifluoroethanol (TFE).

[0363] Paragraph 19. The method of any one of paragraphs 15-18, wherein step (i) is carried out at or near room temperature (i.e., about 20 to 25 °C).

[0364] Paragraph 20. The method of any one of paragraphs 15-19, wherein step (i) is carried out for a period of time of about 5 to 18 hours or 6 to 16 hours.

[0365] Paragraph 21. The method of any one of paragraphs 15-20, wherein R has one of the following structures:

[0366]

[0367] Paragraph 22. The method of paragraph 15, wherein R has one of the following structures:

[0368]

[0369] Paragraph 23. The method of any one of paragraphs 15-21, wherein the halogen is a chlorine.

[0370] Paragraph 24. The method of any one of paragraphs 15-23, wherein the method produces a single diastereomer (such as a syn-diastereomer) of the reserpine ring fusion analog.

[0371] Paragraph 25. A method of synthesizing a reserpate ring fusion analog comprising the steps of:

[0372] 42

[0373] 45835266.1(i1) reacting a mixture of a reserpate fusion analog of Formula IV having the following structure:

[0374]

[0375] Formula (IV)

[0376] wherein each X is a halogen:

[0377] and an acyl chloride having the following structure:

[0378] O

[0379] C

[0380]

[0381] I^R

[0382] wherein R is a substituted or unsubstituted Ci-Ce alkyl, substituted or unsubstituted C -Cs cycloalkyl, substituted or unsubstituted C5-C12 aryl group, or substituted or unsubstituted C5-C12 heteroaryl group; wherein the mixture comprises at least one base compound.

[0383] Paragraph 26. The method of paragraph 25, wherein the at least one base compound is pyridine and the reaction is optionally carried out at or near room temperature (i.e., about 20 to 25 °C) for a period of time of about 24 to 48 hours.

[0384] Paragraph 27. The method of paragraph 25, wherein the mixture further comprises an organic solvent (such as di chloromethane).

[0385] Paragraph 28. The method of paragraph 27, wherein the at least one base compound is an amine base, such as triethanolamine (TEA).

[0386] Paragraph 29. The method of paragraph 28, wherein the mixture further comprises 4-dimethylaminopyridine (DMAP).

[0387] Paragraph 30. The method of any one of paragraphs 25-29, wherein the method is carried out at or near room temperature (i.e., about 20 to 25 °C).

[0388] Paragraph 31. The method of any one of paragraphs 25-30, wherein the method is carried out for a period of time of about 12 to 24 hours.

[0389] Paragraph 32. The method of any one of paragraphs 15-24, wherein the method comprises a further step of dehalogenation to convert the halogens X and optionally convert the -OR group in the analog product into hydrogens.

[0390] 43

[0391] 45835266.1Paragraph 33. A pharmaceutical composition comprising an analog of any one of paragraphs 1-14; a pharmaceutically acceptable earner; and optionally a pharmaceutically acceptable excipient.

[0392] Paragraph 34. A method of treating a disease or condition associated with infection by a Plasmodium parasite in a subject in need thereof, the method comprising the steps of:

[0393] (a) administering the pharmaceutical composition of paragraph 33 to the subject;

[0394] wherein the pharmaceutical composition has a concentration of the reserpine ring fusion analog in a therapeutically effective amount to reduce one or more symptoms associated with infection by the Plasmodium parasite.

[0395] Paragraph 35. The method of paragraph 34, wherein the reseipine ring fusion analog is an antiplasmodial agent against Plasmodium parasites.

[0396] Paragraph 36. The method of paragraph 34 or 35, wherein the Plasmodium parasite is selected from the group consisting of Plasmodium falciparum, P. vivax, P. malariae, P. ovale curtisi, P. ovale wallikeri, P. knowlesi and P. simium.

[0397] Paragraph 37. The method of any one of paragraphs 34-36, wherein the disease is malaria.

[0398] Paragraph 38. The method of any one of paragraphs 34-37, wherein the condition is selected from the group consisting of severe anemia, hypoglycemia, metabolic acidosis, acute kidney injury, splenogmegaly, shock, black water fever, severe malaria, and acute respiratory distress syndrome.

[0399] Paragraph 39. The method of any one of paragraphs 34-38, wherein the concentration of the analog in the pharmaceutical composition is effective to prevent or reduce maturation of the Plasmodium parasites from the trophozoite stage to the schizont stage in the subject, as compared to an untreated control subject.

[0400] Paragraph 40. The method of any one of paragraphs 34-39, wherein the concentration of the analog in the pharmaceutical composition is effective to reduce reinvasion of Plasmodium parasites into red blood cells between approximately 30 to 54 hours post-invasion.

[0401] Paragraph 41. The method of any one of paragraphs 34-40, wherein the concentration of the analog in the pharmaceutical composition is effective to reduce one of more clinical or systemic symptoms selected from the group consisting of fever, chills, headache, fatigue, nausea and vomiting, tachycardia, pain, cough, diarrhea,

[0402] 44

[0403] 45835266.1pulmonary edema, seizures, kidney injury, coma, brain damage, organ failure, anemia, acute respiratory distress syndrome (ARD), circulatory collapse / shock, disseminated intravascular coagulation, acidosis, jaundice and hypoglycemia, compared to an untreated subject.

[0404] Paragraph 42. The method of any one of paragraphs 34-41, wherein the concentration of the analog in the pharmaceutical composition is effective to reduce the levels of parasitemia in the subject as determined by microscopic analysis of Giemsa-stained blood smears compared to the parasitemia levels observed in the same subject prior to treatment or in a comparable subject who was not administered the pharmaceutical composition.

[0405] Paragraph 43. The method of any one of paragraphs 34-42, wherein the concentration of the analog in the pharmaceutical composition is effective to reduce the number of Plasmodium-infected red blood cells in a biological sample, as measured by flow cytometry, compared to the number of infected red blood cells in the same subject prior to treatment or in a subject who was not administered the pharmaceutical composition.

[0406] Paragraph 44. The method of any one of paragraphs 34-43, wherein the concentration of the analog in the pharmaceutical composition is effective to reduce the levels of Plasmodium antigens and / or Plasmodium DNA in a biological sample, as measured by molecular methods such as polymerase chain reaction (PCR), compared to the levels detected in the same subject prior to treatment or in a subject who was not administered the pharmaceutical composition.

[0407] Paragraph 45. The method of any one of paragraphs 34-44, wherein the pharmaceutical composition is administered within 40 hours post-invasion of red blood cells by the Plasmodium parasite, optionally wherein the pharmaceutical composition is administered within 30 hours post-invasion of red blood cells by the Plasmodium parasite.

[0408] Paragraph 46. The method of any one of paragraphs 34-45, further comprising administering to the subject one or more additional therapeutic, prophylactic, diagnostic or nutraceutical active agent(s).

[0409] Paragraph 47. The method of paragraph 46, wherein the one or more active agent(s) is selected from the group consisting of antimicrobial agents, vaccines, anesthetic agents, and anti-inflammatory agents.

[0410] 45

[0411] 45835266.1Paragraph 48. The method of paragraph 46 or 47, wherein the one or more active agent(s) is an anti-malarial antimicrobial agent selected from the group consisting of quinolines, antifolates, and artemisinin derivatives.

[0412] Paragraph 49. The method of any one of paragraphs 46-48, wherein the one or more active agent(s) is an anti-malarial antimicrobial agent selected from the group consisting of Atovaquone / Proguanil (Malarone), Chloroquine, Hydroxychloroquine, Doxycycline, Mefloquine, Primaquine, artesunate, Tafenoquine (ArakodaTM), quinine, and Artemether / lumefantrine, or a combination thereof.

[0413] Paragraph 50. The method of any one of paragraphs 34-49, wherein the composition is administered via a route selected from the group consisting of intramuscular, intraperitoneal, intravenous, subcutaneous, enteral, transdermal, nasal, pulmonary, vaginal, rectal, or sublingual.

[0414] Paragraph 51. The method of any one of paragraphs 34-50, wherein the composition is administered to the subject once or more than once daily, weekly, monthly or less often.

[0415] 45835266.1EXAMPLES

[0416] Example 1: Reserpine-derived Ring Fusion Analogs

[0417] Various reserpine-derived ring fusion analogs were prepared according to the reaction conditions shown in Figures 3 and 4 and afforded as single diastereomer ring fusion analogs at the specified yields.

[0418] Example 2: Reserpine-derived Ring Fusion Analogs as Antiplasmodial Agents for Treating Malaria

[0419] Methods’.

[0420] To assess the stage-specific activity of MG-2-75 in Plasmodium falciparum Dd2 cells, synchronized cultures were prepared using a MACS column followed by treatment with 5% sorbitol. The resulting cultures were adjusted to 1% parasitemia and 2% hematocrit. MG-2-75 was added at five times its ECso concentration at four time points post-invasion: 6, 18, 30, and 42 hours post-invasion (HPI). DMSO and dihydroartemisinin (DHA) served as negative and positive controls, respectively.

[0421] Samples were collected every 12 hours across the intraerythrocytic developmental cycle until the expected point of reinvasion at 54 HPI. Parasite morphology was assessed using Giemsa-stained blood smears, while DNA content was evaluated by flow cytometry. For flow cytometric analysis, samples were fixed in 4% paraformaldehyde, washed with PBS, permeabilized with 0.25% Triton X-100, and stained with the DNA dye YOYO-1. Data were analyzed using FlowJo software. The results are representative of three independent biological replicates.

[0422] MG-2-75 has the following chemical structure:

[0423]

[0424] 45835266.1Results’.

[0425] Analysis of the data revealed that MG- 2-75 exerts its antimalarial activity during the later stages of the parasite’s intraerythrocytic cycle, specifically between the trophozoite and schizont stages. When MG-2-75 was added at 6 or 18 HPI, there was a marked reduction in parasitemia, as indicated by a diminished DNA peak in flow cytometry (Figure 5), and an absence of reinvasion observed in Giemsa-stained smears at 54 HPI. Thus, parasite inhibition led to a diminished peak size and no reinvasion for 6 and 18 HPI compound additions, as well as no reinvasion for 30 HPI compound addition. When the MG-2-75 was added at 42 HPI, abnormal vacuolization was observed in the parasites, but these vacuoles did not co-localize with heme, suggesting they were not digestive vacuoles. For vacuolization that occurred in the parasites at 42 HPI, these vacuoles do not overlap with heme - distinguishing it from the digestive vacuole. When the compound was added at 42 HPI, reinvasion and ring formation still occurred, and the peak was similar to the DMSO control reinvasion peak. Despite this, parasites treated at 42 HPI with MG-2-75 continued to develop and reinvade, with parasitemia levels and morphology comparable to the DMSO-treated control group (Figure 5).

[0426] MG-2-75 was identified as a potent inhibitor of Dd2 parasites (ECso = 0.27 ± 0.03 pM) with low cytotoxicity toward HepG2 cells (ECso > 25 pM). The parent alkaloid (reserpine) exhibited minimal activity against chloroquine-resistant Plasmodium falciparum Dd2 parasites (ECso > 100 pM).

[0427] Structure-activity relationship studies were established using 21 related analogues, among which AB-2-155 was discovered to display amongst the strongest activity as a potent inhibitor of Dd2 parasites (ECso = 0.046 ± 0.01 pM) while maintaining low cytotoxicity toward HepG2 cells (ECso > 25 pM). Stage-specific activity assays revealed that AB-2-155 affects the early and mid-asexual blood-stage parasites. In parasite reduction ratio experiments it was observed that AB-2-155 killed 99.9% of parasites in around 45 hours or more. Antiplasmodial activities of all 23 compounds are summarized in Table 1. Selectivity Index (SI) was generated based on the relative activity between Dd2 and HepG2 cells [HepG2 EC50 / EC50 Dd2 cells] and 99.9% PCT indicated parasite clearance time from the PRR (Parasite Reduction Ratio) experiments.

[0428] AB-2-155 has the following chemical structure:

[0429] 48

[0430] 45835266.1

[0431]

[0432] 45835266.1Table 1. Summary of antiplasmodial activities for reserpine ring fusion analogs.

[0433] Cpd ECso Dd2 ECso 3D7 (pM) ECSo HepG2 Selectivity 99.9% (pM) (pM) Index (SI) PCT Reserpine > 100 > 100 > 100

[0434] MG-2-75 0.27 ± 0.03 0.25 + 0.07 > 25 > 96 55.3 h BB-II-105 0.59 + 0.10 0.59 + 0.13 > 25 > 42

[0435] BB-3-45-2 0.85 ± 0.12 0.53 ± 0.02 > 25 > 29

[0436] BB-II-173 1.24 ± 0.26 1.32 ± 0.05 > 25 > 20

[0437] BB-3-17 2.73 ± 0.41 4.46 ± 0.004 > 25 > 9

[0438] BB-II-143 > 5 > 5 > 25

[0439] AB-1-69 0.23 ± 0.03 0.42 ± 0.01 > 25 > 104

[0440] AB-1-73 0.14 ± 0.02 0.22 ± 0.02 > 25 > 171 54.6 h AB-1-75 0.64 ± 0.03 1.02 ± 0.06 > 25 > 39

[0441] AB-1-83 0.27 ± 0.07 0.41 ± 0.02 > 25 > 93

[0442] AB-1-87 0.21 ± 0.003 0.34 ± 0.03 > 25 > 119

[0443] AB-1-93 0.64 ± 0.03 0.75 ± 0.04 > 25 > 39

[0444] AB-1-97 0.20 ± 0.05 0.29 ± 0.17 > 25 > 125

[0445] AB-1-139 0.30 ± 0.07 0.31 ± 0.10 > 25 > 82

[0446] AB-1-163 0.13 ± 0.03 0.15 ± 0.07 > 25 > 187 55.9 h AB-2-3 0.75 ± 0.09 0.75 ± 0.20 > 25 > 33

[0447] AB-2-81 0.13 ± 0.04 0.11 ± 0.02 > 25 > 191 61.8 h AB-2-115 0.14 ± 0.04 0.14 ± 0.05 > 25 > 184 58.7 h AB-2-155 0.046 ± 0.01 0.12 ± 0.03 > 25 > 543 45.7 h AB-2-171 0.35 ± 0.04 1.12 ± 0.09 > 25 > 71

[0448] AB-4-37 0.35 ± 0.07 0.73 ± 0.07 >25 > 71

[0449] AB-4-81 2.30 ± 0.28 2.88 ± 0.29 >25 > 11

[0450] ATVQ 81.2 h DHA 18.6 h The symbol is for compounds not tested in a particular assay / experiment. All values reported in this table are the result of three, or more, independent experiments. Chloroquine was used as a comparator in doseresponse experiments (Dd2, EC50 = 0.19 ± 0.01 pM; 3D7, EC50 = 0.017 ± 0.001 pM).

[0451] Those skilled in the art will recognize, or be able to ascertain using no more than routine experimentation, many equivalents to the specific embodiments of the invention described herein. Such equivalents are intended to be encompassed by the following claims.

[0452] 50

[0453] 45835266.1

Claims

We claim:

1. A reserpine ring fusion analog having a structure of Formula I as follows:Formula (I)wherein each X is a halogen; andwherein R is a substituted or unsubstituted Ci-Ce alkyl, a substituted or unsubstituted C3-C10 cycloalkyl, or a substituted or unsubstituted benzyl group.5145835266.

12. A reserpate ring fusion analog having a structure of Formula II as follows:Formula (II)wherein each X is a halogen;wherein R is a substituted or unsubstituted C1-C5 alkyl, a substituted or unsubstituted C3-C10 cycloalkyl, or a substituted or unsubstituted benzyl; and wherein R’ is a hydrogen or carboxyl moiety (-C(O)-R”), wherein R” is a substituted or unsubstituted Ci-Ce alkyl, substituted or unsubstituted Cs-Cs cycloalkyl, substituted or unsubstituted C5-C12 aryl group, or substituted or unsubstituted C5-C12 heteroaryl group.

3. The analog of any one of claims 1-2, wherein the halogen is a chlorine.

4. The analog of any one of claims 1-2, wherein the halogen is a bromine.

5. The analog of claim 1, wherein R is a substituted Ci-Ce alkyl having a halogenated Ci-Ce alkyl (such as -CF3) thereon.

6. The analog of claim 5, wherein the substituted Ci-Ce alkyl has the following structure:

7. The analog of claim 1, wherein R is a substituted benzyl group and the substituents are selected from the group consisting of a halogen, a Ci-Ce alkoxy (such as -OMe), and a halogenated Ci-Ce alkyl (such as -CF3).5245835266.

18. The analog of claim 7, wherein the substituted benzyl group has one of the following structures:

9. The analog of claim 1, wherein R is the substituted or unsubstituted C3-C10 cycloalkyl.

10. The analog of claim 9, wherein the unsubstituted C3-C10 cycloalkyl has one of the following structures:

11. The analog of claim 2, wherein R is the substituted or unsubstituted benzyl.

12. The analog of claim 2, wherein R’ is the carboxyl moiety (-C(O)-R”), wherein R” is a substituted or unsubstituted Ci-Ce alkyl, substituted or unsubstituted Cs-Cs cycloalkyl, substituted or unsubstituted C5-C12 aryl group, or substituted or unsubstituted C5-C12 heteroaryl group.

13. The analog of claim 12, wherein the R” of the carboxyl moiety has one of the structures:OMe ; or Me14. The analog of any one of claims 1-2, wherein the analog is a single diastereomer (such as a syn-diastereomer).45835266.

115. A method of synthesizing a reserpine ring fusion analog comprising the steps of: (i) reacting a mixture of an a-haloamide having a structure of Formula III as follows:Formula (III)wherein each X is a halogen; andwherein R is a substituted or unsubstituted Ci-Ce alkyl, a substituted or unsubstituted C3-C13 cycloalkyl, or a substituted or unsubstituted benzyl group;a reserpine in an organic solvent, wherein the reserpine has the following structure:a base compound to produce the reserpine ring fusion analog.

16. A method of synthesizing a reserpate ring fusion analog comprising the steps of:(i) reacting a mixture of an a-haloamide having a structure of Formula III as follows:Formula (III)wherein each X is a halogen; andwherein R is a substituted or unsubstituted Ci-Ce alkyl or a substituted or unsubstituted benzyl group;a reserpate in an organic solvent, wherein the reserpine has the following structure:5445835266.1a base compound to produce the reserpate ring fusion analog.

17. The method of any one of claims 15-16, wherein the base compound is K2CO3.

18. The method of any one of claims 15-16, wherein the organic solvent is 2,2,2-Trifluoroethanol (TFE).

19. The method of any one of claims 15-16, wherein step (i) is carried out at or near room temperature (i.e., about 20 to 25 °C).

20. The method of any one of claims 15-16, wherein step (i) is carried out for a period of time of about 5 to 18 hours or 6 to 16 hours.

21. The method of any one of claims 15-16, wherein R has one of the following structures:

22. The method of any one of claims 15-16, wherein R has one of the following structures:

23. The method of any one of claims 15-16, wherein the halogen is a chlorine.5545835266.

124. The method of any one of claims 15-16, wherein the method produces a single diastereomer (such as a syn-diastereomer) of the analog.

25. A method of synthesizing a reserpate ring fusion analog comprising the steps of:(i1) reacting a mixture of a reserpate fusion analog of Formula IV having the following structure:Formula (IV)wherein each X is a halogen;and an acyl chloride having the following structure:OCI^Rwherein R is a substituted or unsubstituted Ci-Cc, alkyl, substituted or unsubstituted Cs-Cs cycloalkyl, substituted or unsubstituted C5-C12 aryl group, or substituted or unsubstituted C5-C12 heteroaryl group; wherein the mixture comprises at least one base compound.

26. The method of claim 25, wherein the at least one base compound is pyridine and the reaction is optionally carried out at or near room temperature (i.e., about 20 to 25 °C) for a period of time of about 24 to 48 hours.

27. The method of claim 25, wherein the mixture further comprises an organic solvent (such as dichloromethane).

28. The method of claim 27, wherein the at least one base compound is an amine base, such as triethanolamine (TEA).45835266.

129. The method of claim 28, wherein the mixture further comprises 4-dimethylaminopyridine (DMAP).

30. The method of any one of claims 25-29, wherein the method is carried out at or near room temperature (i.e., about 20 to 25 °C).

31. The method of any one of claims 25-29, wherein the method is carried out for a period of time of about 12 to 24 hours.

32. The method of any one of claims 15-16, wherein the method comprises a further step of dehalogenation to convert the halogens X and optionally convert the -OR group in the analog product into hydrogens.

33. A pharmaceutical composition comprising an analog of any one of claims 1-2; a pharmaceutically acceptable carrier; and optionally a pharmaceutically acceptable excipient.

34. A method of treating a disease or condition associated with infection by a Plasmodium parasite in a subject in need thereof, the method comprising the steps of:(a) administering the pharmaceutical composition of claim 33 to the subject; wherein the pharmaceutical composition has a concentration of the reserpine ring fusion analog in a therapeutically effective amount to reduce one or more symptoms associated with infection by the Plasmodium parasite.

35. The method of claim 34, wherein the reserpine ring fusion analog is an antiplasmodial agent against Plasmodium parasites.

36. The method of claim 34 or 35, wherein the Plasmodium parasite is selected from the group consisting of Plasmodium falciparum, P. vivax, P. malariae, P. ovale curtisi, P. ovale wallikeri, P. knowlesi and P. simium.

37. The method of any one of claims 34-35, wherein the disease is malaria.5745835266.

138. The method of any one of claims 34-35, wherein the condition is selected from the group consisting of severe anemia, hypoglycemia, metabolic acidosis, acute kidney injury, splenogmegaly, shock, black water fever, severe malaria, and acute respiratory distress syndrome.

39. The method of any one of claims 34-35, wherein the concentration of the analog in the pharmaceutical composition is effective to prevent or reduce maturation of the Plasmodium parasites from the trophozoite stage to the schizont stage in the subject, as compared to an untreated control subject.

40. The method of any one of claims 34-35, wherein the concentration of the analog in the pharmaceutical composition is effective to reduce reinvasion of Plasmodium parasites into red blood cells between approximately 30 to 54 hours post-invasion.

41. The method of any one of claims 34-35, wherein the concentration of the analog in the pharmaceutical composition is effective to reduce one of more clinical or systemic symptoms selected from the group consisting of fever, chills, headache, fatigue, nausea and vomiting, tachycardia, pain, cough, diarrhea, pulmonary edema, seizures, kidney injury, coma, brain damage, organ failure, anemia, acute respiratory distress syndrome (ARD), circulatory collapse / shock, disseminated intravascular coagulation, acidosis, jaundice and hypoglycemia, compared to an untreated subject.

42. The method of any one of claims 34-35, wherein the concentration of the analog in the pharmaceutical composition is effective to reduce the levels of parasitemia in the subject as determined by microscopic analysis of Giemsa-stained blood smears compared to the parasitemia levels observed in the same subject prior to treatment or in a comparable subject who was not administered the pharmaceutical composition.

43. The method of any one of claims 34-35, wherein the concentration of the analog in the pharmaceutical composition is effective to reduce the number of Plasmodium-infected red blood cells in a biological sample, as measured by flow cytometry, compared to the number of infected red blood cells in the same subject prior to treatment or in a subject who was not administered the pharmaceutical composition.5845835266.

144. The method of any one of claims 34-35, wherein the concentration of the analog in the pharmaceutical composition is effective to reduce the levels of Plasmodium antigens and / or Plasmodium DNA in a biological sample, as measured by molecular methods such as polymerase chain reaction (PCR), compared to the levels detected in the same subject prior to treatment or in a subject who was not administered the pharmaceutical composition.

45. The method of any one of claims 34-35, wherein the pharmaceutical composition is administered within 40 hours post-invasion of red blood cells by the Plasmodium parasite, optionally wherein the pharmaceutical composition is administered within 30 hours post-invasion of red blood cells by the Plasmodium parasite.

46. The method of any one of claims 34-35, further comprising administering to the subject one or more additional therapeutic, prophylactic, diagnostic or nutraceutical active agent(s).

47. The method of claim 46, wherein the one or more active agent(s) is selected from the group consisting of antimicrobial agents, vaccines, anesthetic agents, and antiinflammatory agents.

48. The method of claim 46 or 47, wherein the one or more active agent(s) is an anti-malarial antimicrobial agent selected from the group consisting of quinolines, antifolates, and artemisinin derivatives.

49. The method of any one of claims 46-48, wherein the one or more active agent(s) is an anti-malarial antimicrobial agent selected from the group consisting of Atovaquone / Proguanil (Malarone), Chloroquine, Hydroxychloroquine, Doxycycline, Mefloquine, Primaquine, artesunate, Tafenoquine (ArakodaTM), quinine, and Artemether / lumefantrine, or a combination thereof.

50. The method of any one of claims 34-49, wherein the composition is administered via a route selected from the group consisting of intramuscular, intraperitoneal, intravenous, subcutaneous, enteral, transdermal, nasal, pulmonary, vaginal, rectal, or sublingual.5945835266.

151. The method of any one of claims 34-50, wherein the composition is administered to the subject once or more than once daily, weekly, monthly or less often.45835266.1

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