Fungal efflux pump inhibitors

Abstract

This invention relates to compounds that are efflux pump inhibitors and therefore are useful as potentiators of anti-fungal agents for the treatment of infections caused by fungi that employ an efflux pump resistance mechanism.

Description

FIELD OF THE INVENTION

[0002] The present invention relates to the fields of organic chemistry, biochemistry, medicinal chemistry, microbiology and medicine. In particular, it relates to organic compounds that are fungal efflux pump inhibitors.

BACKGROUND OF THE INVENTION

[0003] The information provided and the references cited herein are not admitted, nor should they be construed, to be prior art to the present invention, but are provided solely to assist the understanding of the reader.

[0004] Fungal infections are relatively rare in immuno-competent patients. In fact, a number of Candida species are often present as benign commensal organisms in the digestive system of healthy individuals (Shepherd, et al., Ann. Rev. Microbiol., 1985, 39:579-614). Fungal infections, however, can be life threatening for immuno-compromised patients. There are three major groups of immuno-compromised individuals that are at risk: (1) cancer patients undergoing chemotherapy, (2) organ transplant patients being treated with immuno-suppressants, and (3) AIDS patients. Data from the National Nosocomial Infections Surveillance System conducted in the United States showed a 487 percent increase in Candida bloodstream infections between 1980 and 1989 (Rinaldi, et al., Antimicrob. Ag. Chemother., 1995, 39:1-8). Oropharyngeal candidiasis is the most common fungal infection complication associated with AIDS with up to 90% of AIDS patients having had at least one episode of the infection (Powderly, AIDS research and Human Retroviruses, 1994, 10:925-929).

[0005] There are relatively few clinically useful anti-fungal agents. Among those available are amphotericin B, flucytosine, fluconazole, itraconazole and ketoconazole (Odds, J. Antimicrob. Chemother., 1993, 31: 463-471). However, resistance to all of these drugs is developing rapidly. Take, for example, fluconazole.

[0006] Fluconazole is currently the most extensively used anti-fungal agent for the treatment of patients with severe candidiasis. It has higher water solubility and a longer plasma half-life than other azole fungicides and has relatively low toxicity. Between 1988 and 1993, fluconazole was used to treat over 15 million patients, including at least 250,000 AIDS patients (Hitchcock, Biochem. Soc. Trans., 1993, 21:1039-1047). Given such wide-spread use, it comes as no surprise that fluconazole-resistant Candida strains have been reported (Rex, et al., Antimicrob. Ag. Chemother., 1995, 39:1-8; Vanden Bossche, et al., 1994, supra). In some cases the resistance was found to be due to mutations in C. albicans itself while in other cases C. albicans was simply displaced by Candida species less susceptible to fluconazole, namely, C. glabrata and C. krusei (Odds, 1993, supra).

[0007] The mechanism of resistance to fluconazole appears to be multifaceted. In one study, amplification of the CYP51 gene (encoding the fluconazole target P-450 protein C14 demethylase) was implicated (Vanden Bossche, et al., Antimicrob. Agents and Chemother., 1994, 36: 2602-2610). In another study, resistance was correlated with the appearance of an altered P-450 target protein with decreased affinity for fluconazole (Hitchcock, Biochem Soc. Trans., 1993, 21:1039-1047). However, fluconazole resistance appears to be primarily due to decreased accumulation of the drug in resistant cells (Vanden Bossche, et al., 1994; Odds, 1993, supra). Species intrinsically resistant to fluconazole such as C. glabrata, C. krusei and Aspergillus fumigatus have also been shown to accumulate less fluconazole (Vanden Bossche, et al., 1994, supra). C. glabrata and C. krusei, on the other hand, have been shown to accumulate itraconazole and to be susceptible to that compound (Marichal et al., Mycoses, 1995, 38:111-117). Thus, it appears that both intrinsic and acquired resistance may be due to decreased drug accumulation in the cell. There are several ways in which a cell can manipulate the intracellular concentration of a compound. One is preventing the compound from gaining access to the interior of the cell in the first place. Another is metabolic decomposition of the compound once it is in the cell. A further means is simply excreting the intact compound before it can have any effect on the cell. This latter approach is called efflux and the cell components involved in efflux, i.e., membrane transporter proteins, are called efflux pumps.

[0008] Efflux pumps are ubiquitous in all types of cells, from bacterial to mammalian (Higgins, Ann. Rev. Cell Biol., 1992, 8:67-113). Efflux is driven either by the energy of ATP hydrolysis (ABC-transporter superfamily) or by proton transfer (Major Facilitator superfamily). Efflux pumps exhibit differing degrees of specificity.

[0009] Some efflux pumps are extremely specific, such as the TetA pump in gram-negative bacteria, which effluxes tetracycline only. Others are less specific; e.g., the MsrA protein in Staphyloccus aureus effluxes not only erythromycin but related macrolides as well. There are also efflux pumps that are quite general in their efflux capability, excreting a variety of structurally unrelated compounds from a cell. Many efflux pumps are clinically significant.

[0010] Resistance to chemotherapeutics in some mammalian cancer cells has been attributed to a multi-drug resistant efflux pump known as P-glycoprotein (Gottesman, et al., Ann. Rev. Biochem., 1993, 62:385-427). Pseudomonas aeruginosa, which causes respiratory infections, adventitious infection in burn patients, etc., uses Mex efflux pumps to eliminate quinolones, as well as other structurally unrelated antibiotics (Nikaido, Science, 1994, 264:382-388). Multiple-drug resistant (MDR) efflux pumps have been implicated in fluconazole resistance in C. albicans and C. glabrata (Parkinson, et al., Antimicrob. Agents Chemother., 1995, 39:1696-1699; Sanglard, et al., Antimicrob. Agents Chemother., 1995, 39:2378-2386; Albertson, et al., Antimicrob. Agents Chemother., 1996, 40:2835-2841).

[0011] Based on the above, it would clearly be desirable to be able to inhibit the activity of fungal efflux pumps so that anti-fungal agents can accumulate in fungal cells in sufficient quantity to exert their effect. The present invention provides compounds that achieve this goal.

SUMMARY OF THE INVENTION

[0012] The present invention relates to compounds that are fungal efflux pump inhibitors. When administered to a patient suffering from an infection caused by a fungal species that employs efflux pump(s) as a resistance mechanism, the compounds inhibit the activity of the pump(s) allowing a co-administrated anti-fungal agent to accumulate in sufficient concentration to inhibit fungal cells and treat the infection.

[0013] Thus, in one aspect, the present invention relates to a chemical compound having the chemical structure: 1

[0014] or a pharmaceutically acceptable salt thereof, wherein:

[0015] A1, A2, A3, A4, A5 and A6 are independently selected from the group consisting of carbon and nitrogen;

[0016] R2 is (1C-4C)alkyl;

[0017] R3, R4, R5, R6, R7, R8, R9, R10, R28 and R29 are independently selected from the group consisting of hydrogen, (1C-4C)alkyl, —CF3, —O(1C-4C)alkyl, —OCH2(3C-6C)cycloalkyl, halo, —OH, —C≡N, —C(O)-(1C-4C)alkyl, —C(O)O-(1C-4C)alkyl, —OC(O)-(1C-4C)alkyl, —NHSO2(1C-4C)alkyl, —NHSO2CF3, —SO2CF3 and 2

[0018]  provided that, if A2 and/or A3 is nitrogen, R28 and/or R29 do not exist; and, R1 is selected from the group consisting of hydrogen, -(1C-4C)alkyl, -(3C-6C)cycloalkyl, —CH2(3C-6C)cycloalkyl and 3

[0019] or R1 is —S(O)mR11, wherein:

[0020] m is 1 or 2;

[0021] R11 is selected from the group consisting of —NR12R13, (1C-4C)alkyl optionally substituted with an —NR12R13 group, (2C-4C)alkenyl, —CF3 and phenyl optionally substituted with one or more entities selected from the group consisting of (1C-4C)alkyl, —OH, —O(1C-4C)alkyl, halo and —C≡N, wherein:

[0022] R12 and R13 are independently selected from the group consisting of hydrogen, CF3 and (1C-4C)alkyl, or together with the nitrogen to which they are bonded form a cyclic entity selected from the group consisting of: 4

[0023] A6, A7 and A8 are independently selected from the group consisting of carbon and nitrogen;

[0024] R14 is selected from the group consisting of hydrogen, -(1C-4C)alkyl, —O(3C-6C)cycloalkyl, —OH, —C≡N, and halo; and,

[0025] R15 is selected from the group consisting of hydrogen, -(1C-4C)alkyl, —C(O)H, —C(O)O-(1C-4C)alkyl, —C(O)OCH2(3C-6C)cycloalkyl, —C(O)NH-(1C-4C)alkyl, —C(O)NHCH2(3C-6C)cycloalkyl, and -Nt-Boc;

[0026] or R1 is —(CH2)nC(O)R16, wherein:

[0027] n is 0, 1, 2 or 3;

[0028] R16 is selected from the group consisting of:

[0029] hydrogen, -(1C-4C)alkyl, -(3C-6C)cycloalkyl, 5

[0030] R30 is selected from the group consisting of hydrogen and —C(O)OR31, wherein:

[0031] R31 is selected from the group consisting of hydrogen and -(1C-4C)alkyl;

[0032] or, R16 is —OR17, wherein:

[0033] R17 is selected from the group consisting of hydrogen, —(CH2CH2O)q-(1C-4C)alkyl, and (1C-4C)alkyl optionally substituted with an entity selected from the group consisting of —NR12R13,—CN≡N, 6

[0034] A9 is selected from the group consisting of —NH, —N(1C-4C)alkyl, —NCH2(3C-6C)cycloalkyl, —N(3C-6C)cycloalkyl and sulfur;

[0035] A10 and A11 are independently selected from the group consisting of carbon and nitrogen; and,

[0036] q is 1, 2, 3 or 4;

[0037] or R16 is —NR18R19, wherein:

[0038] R18 and R19 are independently selected from the group consisting of hydrogen, (1C-4C)alkyl optionally substituted with an entity selected from the group consisting of —O(1C-4C)alkyl, —OH, —C≡N, —NH2, —NH(1C-4C)alkyl, —N((1C-4C)alkyl)2 and —S(O)nR20 or R18 is —C≡N and R19 is hydrogen;

[0039] wherein:

[0040] R20 is selected from the group consisting of —NR12R13, (1C-4C)alkyl optionally substituted with an —NR12R13 group, (2C-4C)alkenyl, —CF3 and phenyl optionally substituted with one or more entities selected from the group consisting of (1C-4C)alkyl, —OH, —O(1C-4C)alkyl, halo and —C≡N;

[0041] n is 1 or 2;

[0042] or, R18 and R19 together with the nitrogen to which they are bonded form a cyclic entity selected from the group consisting of: 7

[0043] or R16 is —CH(R21)(CH2)pR22, wherein:

[0044] p is 0, 1 or 2;

[0045] R21 is independently selected from the group consisting of hydrogen and (1C-4C)alkyl optionally substituted with an entity selected from the group consisting of —OH, —O(1C-4C)alkyl, —OCH2(3C-6C)cycloalkyl and —C≡N;

[0046] R22 is —OR23, wherein R23 is selected from the group consisting of hydrogen, —(CH2CH2O)q-(1C-4C)alkyl, —CH2(3C-6C)cycloalkyl and (1C-4C)alkyl optionally substituted with an entity selected from the group consisting of —NR12R13, —C≡N, 8

[0047] A9 is selected from the group consisting of —NH, —N(1C-4C)alkyl, —N(3C-6C)cycloalkyl, —NCH2(3C-6C)cycloalkyl and sulfur;

[0048] A10 and A11 are independently selected from the group consisting of carbon and nitrogen; and,

[0049] q is 1, 2, 3 or 4;

[0050] or R22 is —NR24R25, wherein R24 and R25 are independently selected from the group consisting of hydrogen, (1C-4C)alkyl and —C(O)OR26, wherein:

[0051] R26 is independently selected from the group consisting of hydrogen and (1C-4C)alkyl; or,

[0052] together with the nitrogen to which they are bonded R24 and R25 form an entity selected from the group consisting of: 9

[0053] wherein J− is a pharmaceutically acceptable anion;

[0054] or R22 is selected from the group consisting of: 10

[0055] or R16 is selected from the group consisting of: 11

[0056] R27 is selected from the group consisting of hydrogen, (1C-4C)alkyl, -(3C-6C)cycloalkyl, —CH2(3C-6C)cycloalkyl and —OC(O)O-(1C-4C)alkyl;

[0057] or R1 is 12

[0058]  ; wherein:

[0059] A12 is selected from the group consisting of —NH, sulfur and oxygen, and, A13, A14 and A15 are independently selected from the group consisting of carbon and nitrogen. The compound may be a racemic mixture or it may be a pure enantiomer.

[0060] An aspect of this invention is the above compound or salt in which R2 is —CH3.

[0061] An aspect of this invention is any of the above compounds or salts in which A2, A3, A4, A5 and A6 are carbon.

[0062] An aspect of this invention is any of the above compounds or salts in which R7 and R8 are independently selected from the group consisting of —O(1C-4C)alkyl and —OCH2(3C-6C)cycloalkyl and R3, R4, R5, R28 and R29 are hydrogen.

[0063] An aspect of this invention is any of the above compounds or salts in which R7 and R8 are OCH3.

[0064] An aspect of this invention is any of the above compounds or salts in which R7 and R8 are: 13

[0065] An aspect of this invention is any of the above compounds or salts wherein A4, A5 and A6 are carbon, R9 is selected from the group consisting of hydrogen and halogen; and, R10 is hydrogen.

[0066] An aspect of this invention is any of the above compounds or salts in which R9 is fluorine.

[0067] An aspect of this invention is any of the above compounds or salts in which A2, A4, A5 and A6 are carbon and A3 is nitrogen.

[0068] An aspect of this invention is the compound or salt immediately above in which R28 is hydrogen and R7 and R8 are selected from the group consisting of —O(1C-4C)alkyl and —OCH2(3C-6C)cycloalkyl.

[0069] An aspect of this invention is any of the above compounds or salts in which A3 is nitrogen in which R7 and R8 are OCH3.

[0070] An aspect of this invention is any of the above compounds or salts in which A3 is nitrogen in which R3-R5 and R10 are hydrogen.

[0071] An aspect of this invention is any of the above compounds or salts in which A3 is nitrogen in which R9 is selected from the group consisting of hydrogen and fluorine.

[0072] An aspect of this invention is any of the above compounds or salts in which A1 is carbon.

[0073] An aspect of this invention is any of the above compounds or salts in which R3-R5 and R10 are hydrogen.

[0074] An aspect of this invention is any of the above compounds or salts in which R9 is selected from the group consisting of hydrogen and fluorine.

[0075] An aspect of this invention is any of the above compounds or salts in which R6 or R8 is selected from the group consisting of —OCH3 and 14

[0076] and R7 is F.

[0077] An aspect of this invention is any of the above compounds or salts in which A3 is carbon, R6 or R8 is selected from the group consisting of —OCH3 and 15

[0078] and R29 is —C(O)CH3.

[0079] An aspect of this invention is any of the above compounds or salts in which R6 or R8 and R7 are 16

[0080] An aspect of this invention is any of the above compounds or salts in which A2 is carbon and R28 is —NHSO2CH3.

[0081] An aspect of this invention is any of the above compounds or salts in which A2 is carbon and R28 is —NHSO2CF3.

[0082] An aspect of this invention is any of the above compounds or salts in which A2 is carbon and R28 is —SO2CF3.

[0083] An aspect of this invention is any of the above compounds or salts in which A2 is carbon; and R28 is 17

[0084] An aspect of this invention is a method for inhibiting a fungal cell that employs an efflux pump resistance mechanism, comprising contacting the cell with an anti-fungal agent and any one of the above compounds or salts of this invention.

[0085] The anti-fungal agent is an azole anti-fungal agent in an aspect of this invention.

[0086] The azole fungicide is selected from the group consisting of fluconazole and posaconazole in an aspect of this invention.

[0087] The fungal cell is first contacted with the compound and then with the anti-fungal agent in an aspect of this invention.

[0088] The fungal cell is contacted with the compound and the anti-fungal agent simultaneously in an aspect of this invention.

[0089] The fungal cell is of the genus Candida in an aspect of this invention.

[0090] The genus Candida cell is selected from the group consisting of C. albicans, C. krusei, C. tropicalis, C. parapsilosis and C. glabrata in an aspect of this invention.

[0091] The fungal cell is of the genus Aspergillus cell in an aspect of this invention.

[0092] The genus Aspergillus cell is Aspergillus fumigatus in an aspect of this invention.

[0093] An aspect of this invention is a method for treating an infection caused by a fungus that employs an efflux pump resistance mechanism, comprising administering to a patient in need thereof a therapeutically effective amount of an anti-fungal agent and any one of the above compounds or salts of this invention.

[0094] The infection is caused by a genus Candida fungus in an aspect of this invention.

[0095] The Candida fungus is C. albicans, C. krusei, C. tropicalis, C. parapsilosis or C. glabrata in an aspect of this invention.

[0096] The infection is caused by a genus Aspergillus fungus in an aspect of this invention.

[0097] The genus Aspergillus fungus is Aspergillus fumigatus in an aspect of this invention.

[0098] The compound and the anti-fungal agent are administered simultaneously in an aspect of this invention.

[0099] The compound is administered first followed by administration of the anti-fungal agent in an aspect of this invention.

[0100] An aspect of this invention is a pharmaceutical composition, comprising a pharmaceutically acceptable carrier or excipient and any one of the above compounds or salts of this invention.

[0101] The pharmaceutical composition further comprising a therapeutically effective amount of an anti-fungal agent in an aspect of this invention.

[0102] The anti-fungal agent is an azole anti-fungal agent in an aspect of this invention.

[0103] The azole anti-fungal agent is fluconazole or posaconazole in an aspect of this invention.

DETAILED DESCRIPTION OF THE INVENTION

[0104] Brief Description of the Tables

[0105] Table 1 provides methods for the synthesis of illustrative compounds of this invention.

[0106] Table 2 provides data regarding the potentiation, by representative compounds of this invention, of fluconazole against a Candida albicans strain over-expressing CDR1 and CDR2 efflux pumps.

[0107] Table 3 provides data regarding the potentiation, by representative compounds of this invention, of fluconazole against a Candida glabrata strain over-expressing CgCDR1 and CgCDR2 efflux pumps.

[0108] Definitions

[0109] As used herein, the term “alkyl” refers to a straight or branched chain saturated aliphatic hydrocarbon. Preferably, the alkyl group consists of 1 to 20 carbon atoms (whenever a numerical range such as “1-20” or “1 to 20” is provided herein, it means that the group may consist of 1 carbon atom, 2 carbon atoms, 3 carbon atoms, etc., up to and including 20 carbon atoms). More preferably, an alkyl group of this invention is a medium size alkyl having 1 to 10 carbon atoms. Most preferably, it is a lower alkyl having 1 to 4 carbon atoms. The size of an alkyl may be indicated by the formula (Ca-Cb)alkyl where a and b are integers from 1 to 20 and indicate how may carbons are in the alkyl chain. For example, a (C1-C4)alkyl refers to a straight or branched chain alkyl consisting of 1, 2, 3 or 4 carbon atoms. An alkyl group may be substituted or unsubstituted. When substituted, the substituent group(s) is preferably one or more independently selected from the group consisting of (C3-C6)cycloalkyl, halo, hydroxy, alkoxy, acyloxy, amino, acylamino, amido, carboxy, carbonyl, alkylcarbonyl, alkoxycarbonyl, cyano and nitro.

[0110] A “cycloalkyl” group refers to a 3 to 8 member all-carbon monocyclic ring. The designation (C3-C6)cycloalkyl, for example, refers to a 3-, 4-, 5- or 6-member all-carbon ring. A cycloalkyl group may contain one or more double bonds but it does not contain a fully conjugated pi-electron system; i.e., it is not aromatic. Examples, without limitation, of cycloalkyl groups are cyclopropane, cyclobutane, cyclopentane, cyclopentene, cyclohexane, cyclohexadiene, adamantane, cycloheptane and, cycloheptatriene. A cycloalkyl group may be substituted or unsubstituted. When substituted, the substituent group(s) is preferably one or more independently selected from the group consisting of unsubstituted (C1-C4)alkyl, halo, hydroxy, alkoxy, acyloxy, amino, acylamino, amido, carboxy, carbonyl, alkylcarbonyl, alkoxycarbonyl, cyano and nitro.

[0111] An “alkenyl” group refers to an alkyl group, as defined herein, having at least two carbon atoms and at least one carbon-carbon double bond. As used herein, (C2-C4)alkenyl, for example, refers to a 2, 3, or 4 carbon alkenyl group.

[0112] An “aryl” group refers to an all-carbon monocyclic or a fused-ring polycyclic (i.e., rings which share adjacent pairs of carbon atoms) group having a completely conjugated pi-electron system. Examples, without limitation, of aryl groups are phenyl, naphthalenyl and anthracenyl. The aryl group may be substituted or unsubstituted. When substituted, the substituted group(s) is preferably one or more independently selected from the group consisting of alkyl, halo, (halo)3C—, hydroxy, alkoxy, acyloxy, amino, acylamino, amido, carboxy, carbonyl, alkylcarbonyl, alkoxycarbonyl, cyano and nitro.

[0113] As used herein, a “heteroaryl” group refers to a monocyclic or fused ring in which one or more of the rings contains one or more atoms selected from the group consisting of nitrogen, oxygen and sulfur and, in addition, sufficient double bonds to establish a fully conjugated pi-electron system. Examples, without limitation, of heteroaryl groups are pyrrole, furan, thiophene, imidazole, oxazole, thiazole, pyrazole, pyridine, pyrimidine, quinoline, isoquinoline, purine and carbazole. A heteroaryl group may be substituted or unsubstituted. When substituted, the substituted group(s) is preferably one or more independently selected from the group consisting of alkyl, halo, (halo)3C—, hydroxy, alkoxy, acyloxy, amino, acylamino, amido, carboxy, carbonyl, alkylcarbonyl, alkoxycarbonyl, cyano and nitro.

[0114] A “heteroalicyclic” group refers to a monocyclic or fused ring group having in the ring(s) one or more atoms selected from the group consisting of nitrogen, oxygen and sulfur. The rings may also have one or more double bonds. However, the rings do not have a completely conjugated pi-electron system. The heteroalicyclic ring may be substituted or unsubstituted. When substituted, the substituted group(s) is preferably one or more independently selected from the group consisting of alkyl, halo, (halo)3C—, hydroxy, alkoxy, acyloxy, amino, acylamino, amido, carboxy, carbonyl, alkylcarbonyl, alkoxycarbonyl, cyano and nitro.

[0115] An “halo” group refers to fluorine, chlorine, bromine or iodine.

[0116] An “hydroxy” group refers to an —OH group.

[0117] An “alkoxy” group refers to an —O(alkyl) group.

[0118] An “acyloxy” group refers to an —OC(O)(alkyl) group.

[0119] An “amino” group refers to an —NRR′ group wherein R and R′ are independently selected from the group consisting of hydrogen and alkyl, wherein the alkyl group is not further substituted.

[0120] An “acylamino” group refers to a —NRC(O)(alkyl) group wherein R is selected from the group consisting of hydrogen and unsubstituted alkyl.

[0121] An “amido” group refers to a —C(O)NRR′ group wherein R and R′ are independently selected from the groups consisting of hydrogen and alkyl, the alkyl group being not further substituted.

[0122] A “carboxy” group refers to a —C(O)OH group.

[0123] A “carbonyl” group refers to a —C(O)H group.

[0124] An “alkylcarbonyl” group refers to a —C(O)(alkyl) group.

[0125] An “alkoxycarbonyl” group refers to a —C(O)O(alkyl) group wherein the alkyl group is not further substituted.

[0126] A “cyano” group refers to a —C≡N group.

[0127] A “nitro” group refers to a —NO2 group.

[0128] “t-Boc” refers to a t-butoxycarbonyl group; i.e., (CH3)3COC(═O)—.

[0129] The term “efflux pump” refers to a protein assembly which exports molecules from the cytoplasm or periplasm of a cell to the external environment in an energy dependent fashion.

[0130] An “efflux pump inhibitor” is a compound which interferes with the ability of an efflux pump to export molecules from a cell. In particular, the efflux pump inhibitors of this invention interfere with a pump's ability to excrete therapeutic anti-fungal agents from fungal cells.

[0131] By a fungus that “employs an efflux pump resistance mechanism” is meant that the fungal cells are known or are shown to excrete anti-fungal agents from their cytoplasm or periplasm to the external environment and thereby reduce the concentration of the anti-fungal agent in the cells to below that necessary to inhibit the growth and/or proliferation of the cells.

[0132] In the context of cell growth, the term “inhibit” means that the rate of growth and/or proliferation of a cellular population is decreased, preferably stopped. By “stopped” is preferably meant permanently; that is, the cells are killed. Inhibition can be monitored by, for example, comparing the difference in turbidity of liquid cultures, or the difference in plaque size for cultures on solid media, in the presence and absence of an inhibitory agent.

[0133] As used herein, the term “overproduces” refers to the presence in a fungal strain of a significantly greater amount of a functional efflux pump or pumps than that found in most naturally-occurring (usually non-nosocomial) isolates of that strain. A strain that overproduces an efflux pump would, of course, be expected to more efficiently export substrate molecules. In contrast, a “wild-type” strain will produce an efflux pump or pumps at a level that is typical of natural isolates of a particular fungal species.

[0134] As used herein, the term “anti-fungal agent” refers to a compound that is either fungicidal or fungistatic. A fungicide kills fungal cells while a fungistat slows or stops cell growth and/or proliferation so long as the compound is present. The efflux pump inhibitors of this invention may be somewhat fungicidal or fungistatic in their own right, but their primary utility resides in their ability to potentiate other anti-fungal agents by inhibiting efflux pump activity in resistant fungal strains.

[0135] An “azole” anti-fungal agent refers to any member of those classes of anti-fungal agents characterized by one or more imidazole or triazole rings in their chemical structure. Examples, without limitation, of anti-fungal azole compounds are butoconazole, clotrimazole, fenticonazole, ketoconazole, sulfconazole, fluconazole, itraconazole, terconazole, posaconazole, triticonazole, imibenconazole, voriconazole, and metaconazole.

[0136] By “potentiation” of an anti-fungal agent is meant that a compound of this invention counteracts the efflux resistance mechanism in a fungal strain sufficiently for an anti-fungal agent to inhibit the growth and/or proliferation of fungal cells at a lower concentration than in the absence of the compound. In cases where resistance is essentially complete, i.e., an anti-fungal compound has no effect on the fungal cells, potentiation means that, in the presence of a compound of this invention, the anti-fungal agent inhibits the fungus and thereby treats the infection at a pharmaceutically acceptable dosage.

[0137] A “sub-inhibitory concentration” of an anti-fungal agent refers to a concentration that is less than that required to inhibit a majority of the cells in a population of a fungal species. Generally, a sub-inhibitory concentration refers to a concentration that is less than the Minimum Inhibitory Concentration (MIC), which is defined, unless specifically stated to be otherwise, as the concentration required to produce an 80% reduction in the growth or proliferation of a target fungus.

[0138] As used herein, the term “treat,” treatment,” or “treating” refers to the administration of a therapeutically or prophylactically effective amount of a composition comprising a compound of this invention together with an anti-fungal agent to a patient in need of such treatment.

[0139] As used herein, “infect,” or “infection” refers to the establishment in a patient of a population of a fungus that results in a deleterious effect on the health or well-being of the patient and/or gives rise to discernable symptoms associated with the particular fungus.

[0140] A “pharmaceutical composition” refers to a mixture of one or more of the compounds described herein, or physiologically acceptable salts or prodrugs thereof, with other chemical components, such as pharmaceutically acceptable carriers and excipients. The purpose of a pharmaceutical composition is to facilitate administration of a compound to a patient.

[0141] A “pharmaceutically acceptable salt” of a compound of this invention refers to the compound in a charged form together with a counter-ion. In general, a compound of this invention will be a positively charged species, usually in the form of an ammonium cation. In such case, the negatively charged counter-ion is a pharmaceutically acceptable anion such as, without limitation, chloride, bromide, iodide, nitrate, phosphate, sulfate, acetate, trifluoroacetate, propionate, butyrate, maleate, fumarate, methanesulfonate, ethanesulfonate, 2-hydroxyethyl-sulfonate, n-propylsulfonate isopropylsulfonate, lactate, malate or citrate. Pharmaceutically acceptable salts in which the compound of this invention forms the positively-charged species are obtained by reacting the compound with the appropriate acid. For example, to make an ammonium chloride salt of a compound of this invention, the compound would be reacted with hydrochloric acid.

[0142] A “prodrug” refers to a compound, which is converted into the parent drug in vivo. Prodrugs are often useful because they may be easier to administer than the parent drug. They may, for instance, be bioavailable by oral administration whereas the parent drug is not. A prodrug may also have improved solubility in pharmaceutical compositions over the parent drug. An example, without limitation, of a prodrug would be a compound which is administered as an ester (the “prodrug”) to facilitate transmittal across a hydrophobic cell membrane where water solubility is detrimental. The ester is then metabolically hydrolyzed in the cell to the carboxylic acid, which is the active entity.

[0143] A further example of a prodrug would be a short polypeptide such as, without limitation, a 2 to 10 amino acid polypeptide, which is bonded through a terminal amino group to a carboxy group of a compound of this invention. The polypeptide may also bond through a terminal carboxy group with an amino group of a compound herein. The polypeptide hydrolyzes or is metabolized in vivo to release the active molecule.

[0144] As used herein, a “pharmaceutically acceptable carrier” refers to a carrier or diluent that does not cause significant irritation to a patient and does not abrogate the biological activity and properties of the administered compound.

[0145] An “excipient” refers to an inert substance added to a pharmaceutical composition to further facilitate administration of a compound. Examples, without limitation, of excipients include calcium carbonate, calcium phosphate, various sugars and types of starch, cellulose derivatives, gelatin, vegetable oils and polyethylene glycols.

[0146] As used herein, the terms “prevent”, “preventing” and “prevention” refer to a method for barring a patient from acquiring a fungal infection in the first place.

[0147] As used herein, the terms “treat”, “treating” and “treatment” refer to a method of alleviating or abrogating a fungal infection and/or its attendant symptoms once a patient has been infected.

[0148] As used herein, “administer,” administering,” or “administration” refers to the delivery to a patient of a compound, salt or prodrug of the present invention or of a pharmaceutical composition containing a compound, salt or prodrug of this invention to a patient for the purpose of inhibiting a fungal efflux pump. It also refers to the delivery of a composition comprising a compound, salt or prodrug of this invention in combination with an anti-fungal agent, in which case the purpose is the treatment or prevention of a fungal infection.

[0149] The term “patient” refers to any living entity capable of being infected by a fungus. In particular, a “patient” refers to a mammal such as a dog, cat, horse, cow, pig, rabbit, goat or sheep. Most particularly, a patient refers to a human being.

[0150] The term “therapeutically effective amount,” as used herein, refers to that amount of a compound of this invention that, together with an anti-fungal agent, will relieve to some extent one or more of the symptoms of a fungal infection. In particular, a therapeutically effective amount refers to that amount of a compound of this invention that, together with an anti-fungal agent: (1) reduces, preferably eliminates, the population of fungal cells in the patient's body, (2) inhibits (i.e., slows, preferably stops) proliferation of the fungal cells, (3) inhibits (i.e., slows, preferably stops) spread of the infection, and/or, (4) relieves (preferably, eliminates) one or more symptoms associated with the infection.

[0151] The term “prophylactically effective amount” refers to that amount of a compound of this invention and an anti-fungal agent that has the effect of (1) maintaining a reduced level of a population of fungal cells achieved by a previously administered therapeutically effective amount of the compounds; (2) maintaining the level of inhibition of proliferation of fungal cells achieved by administration of a therapeutically effective amount; (3) maintaining the degree of inhibition of spread of the infection achieved by a therapeutically effective amount; and/or (4) maintaining the level of relief of one or more symptoms or, or if symptoms were eliminated, maintaining the non-existence of symptoms associated with a fungal infection achieved by administration of a therapeutically effective amount of the compound of this invention. A prophylactically effective amount also refers to that amount of a composition comprising a compound of this invention and an anti-fungal agent that will prohibit a fungus from accumulating in a susceptible organism in sufficient amount to cause an infection. An example of a susceptible organism would be an immuno-compromised patient such as someone who has undergone transplant surgery and therefore is being treated with immuno-suppressants, or a person suffering from AIDS.

[0152] “In vitro” refers to procedures performed in an artificial environment such as, e.g., without limitation, a test tube or culture medium.

[0153] “In vivo” refers to procedures performed within a living organism such as, without limitation, a mouse, rat or rabbit.

[0154] A “racemic mixture” refers to a 1:1 mixture of two optical isomers.

[0155] An “pure enantiomer” refers to a compound that is greater than 90%, preferably greater than 95% and, most preferably, greater than 98% a single optical isomer.

[0156] Discussion

[0157] The present invention relates to the inhibition of efflux pump activity in fungal species and the concurrent potentiation of anti-fungal agents. The identification and use of efflux pump inhibitors is described in Chamberland et al., Internat. Patent Appl. No. PCT/US96/05469, WO96/33285, entitled “Efflux Pump Inhibitors.” The following is a description of several efflux pumps that confer resistance to fluconazole on Candida albicans. The description is exemplary only and is not intended to limit the scope of this invention in any manner whatsoever.

[0158] Three MDR pumps have been demonstrated to confer resistance to fluconazole in clinical isolates of C. albicans (Sanglard et al., 1996, Antimicrob. Ag. Chemother. 40:2300-2305). These pumps are CDR1 (ABC-family, Prasad et al., 1995, Curr. Genet., 27:320-329), CDR2 (ABC-family, Sanglard et al, 1996, supra) and BenR (MF-family, Benyaakov et al., 1994). The genes which encode CDR1 and CDR2, i.e., cdr1 and cdr2, have been shown to be over-expressed in several C. albicans isolates from AIDS patients with whom fluconazole therapy has failed. Strains that over-express these genes have also been shown to be resistant to ketoconazole and itraconazole. Over-expression of benR, on the other hand, conferred resistance to fluconazole only. To further explore the resistance mechanism, C. albicans strains were prepared in which the genes expressing individual pumps were deleted. Strains were also produced having multiple gene deletions to further study specificity of the pumps and their role in intrinsic resistance to azole anti-fungals. CDR1 was shown to play a significant role in the intrinsic resistance of C. albicans to azoles in that deletion of the cdr1 gene rendered the strain more susceptible. Deletion of the CDR2 and BenR genes also contributed to intrinsic resistance, but only when cdr1 was also deleted. A C. albicans mutant which was deprived of all known efflux pumps was 30-fold more susceptible to azole anti-fungal agents than the parent strain.

[0159] In another study, two homologs of cdr1 and benR, cgcdr and cgben, were cloned from resistant C. glabrata suggesting that a similar resistance mechanism was at work in that species. An active efflux pump in azole-resistant Aspergillus nidulans has also been identified (Waard and van Nistelrooy, 1980, Pesticide Biochem. Physiol. 13:255-266).

[0160] Thus, it appears that, in general, strains that are cross-resistant to several anti-fungal azoles tend to over-express CDR1-type broad-spectrum pumps while strains that are resistant only to fluconazole over-express the narrow-spectrum BenR-type pump.

[0161] Compounds of this invention are capable of effectively inhibiting many of the above efflux pumps. They may be used to combat both intrinsic and acquired resistance and may in fact expand the spectrum of activity of anti-fungal agents against previously non-susceptible species.

[0162] The compounds of this invention are particularly effect in overcoming efflux pump-mediated resistance to azole anti-fungals, expecially fluconazole and posaconazole.

[0163] Synthesis

[0164] The following is a General Method (GM) for the synthesis of the compounds of this invention. Neither the syntheses nor any of the compounds described below are intended, nor are they to be construed, as limiting the scope of this invention in any manner whatsoever. Other approaches to the synthesis of the compounds will become apparent to those skilled in the art based on the disclosures herein and are within the scope of this invention.

[0165] GM Compound

[0166] (3-(3-Chloro-phenyl)-1-(2,4-dimethoxy-phenyl)-1-{1-[3-(4-methyl-piperazin-1-yl)-4-oxo-3,4-dihydro-quinazolin-2-yl]-ethyl}-urea): 18

[0167] A solution of anthranilic acid (15 g, 109.4 mmol) in 21 mL (164.1 mmol) of propionic anhydride was stirred at 100° C. for 1.5 hours. The excess propionic anhydride was evaporated (15 torr, 80° C. water bath). The crude mass was co-evaporated three times with toluene to give A (18.723 g, 98%).

[0168] 1 H-NMR (300 MHz, DMSO-d6) δ: 1.23 (t, J=7.8 Hz, 3H), 2.67 (q, J=7.8 Hz, 2H), 7.50-7.65 (m, 2H), 7.89 (dt, J=7.6, 1.8 Hz, 1H), 8.07 (dd, J=7.6, 1.8 Hz, 1H). 19

[0169] To a suspension of A (18.723 g, 107.0 mmol) in 28 mL of acetic acid was dropwise added 1-amino-4-methylpiperazine (13.48 mL, 112.0 mmol). The mixture was stirred at 90° C. for 14 hours before being evaporated and co-evaporated three times with toluene. The residue was dissolved in water and the pH of the solution was adjusted to 3 by addition of 1M aqueous hydrochloric acid. The aqueous layer was extracted three times with ethyl ether and the combined organic layers were discarded. The aqueous layer was basified to pH 11 by addition of 2M aqueous sodium hydroxide. After saturation by addition of solid sodium chloride and three extractions with ethyl acetate, the combined organic layers were washed with water, dried over sodium sulfate, filtered through cotton and evaporated in vacuo to give B (20.714 g, 71%).

[0170] 1 H-NMR (300 MHz, DMSO-d6) δ: 1.23 (t, J=7.3 Hz, 3H), 2.15 (m, 2H), 2.21 (s, 3H), 2.76 (m, 2H), 2.80-2.95 (m, 4H), 3.96 (m, 2H), 7.45 (dt, J=8.1, 1.5 Hz, 1H), 7.58 (dd, J=8.1, 1.5 Hz, 1H), 7.76 (dt, J=8.1, 1.5 Hz, 1H), 8.06 (dd, J=8.1, 1.5 Hz, 1H). 20

[0171] To a solution of B (5 g, 18.4 mmol) and sodium acetate (3.4 g, 41 mmol) in 30 mL of acetic acid was added pyridinium tribromide (11.8 g, 37 mmol). The resulting mixture was stirred at 50° C. for two hours before being cooled to 0° C. The precipitate that formed was filtered off and washed with acetic acid and hexanes. The resulting powder was suspended in water and the pH was adjusted to 9 by addition at 0° C. of a saturated solution of aqueous potassium carbonate. The white solid that remained was filtered, rinsed with water and dried in vacuo to give C (4.2 g, 65%).

[0172] 1 H-NMR (300 MHz, DMSO-d6) δ: 2.01 (d, J=6.6 Hz, 3H), 2.28 (s, 3H), 2.34 (m, 2H), 2.85 (m, 2H), 3.04 (m, 2H), 3.94-4.03 (m, 2H), 5.72 (q, J=6.6 Hz, 1H), 7.55 (dt, J=8.1, 1.5 Hz, 1H), 7.68 (dd, J=8.1 Hz, 1.5 Hz, 1H), 7.84 (dt, J=8.1, 1.5 Hz, 1H), 8.12 (dd, J=8.1, 1.5 Hz, 1H).

[0173] MS (ES+) m/z 351/353 (M++H). 21

[0174] A suspension of C (1.5 g, 4.27 mmol), 2,4-dimethoxyaniline (0.785 g, 5.12 mmol), and potassium carbonate (0.708 g, 5.12 mmol) in 11 mL of anhydrous dimethylformamide was stirred at 85° C. for 4.5 hours. The resulting mixture was diluted with water and extracted three times with a 3/1 (v/v) mixture of ethyl acetate and hexanes. The combined organic layers were washed with water, dried over sodium sulfate, filtered, and evaporated to give a dark brown oil which was purified by flash chromatography on silica gel (ethyl acetate/methanol 100/0 to 97.5/2.5 to 95/5 to 90/10) to give D (1.688 g, 69%).

[0175] 1 H-NMR (300 MHz, CDCl3) δ: 1.59 (d, J=6.6 Hz, 3H), 2.26-2.50 (m, 2H), 2.39 (s, 3H), 2.78-3.00 (m, 4H), 3.71 (s, 3H), 3.86 (s, 3H), 4.27, 4.34 (2m, 2H), 5.20 (q, J=6.6 Hz, 1H), 6.34 (dd, J=8.7, 2.5 Hz, 1H), 6.44 (d, J=2.5 Hz, 1H), 6.61 (d, J=8.7 Hz, 1H), 7.40 (dt, J=8.1, 1.5 Hz, 1H), 7.58-7.74 (m, 2H), 8.20 (dd, J=8.1, 1.5 Hz, 1H).

[0176] MS (ES+) m/z 424 (M++H). 22

[0177] At 0° C., 3-chlorophenyl isocyanate (165 mL, 1.36 mmol) in 1.5 mL of 1,2-dichloromethane was dropwise added to a solution of D (0.522 g, 1.23 mmol) in 6.5 mL of 1,2-dichloroethane. The resulting mixture was stirred at 0° C. to room temperature for 5 hours before being evaporated in vacuo. The residue was purified by flash chromatography on silica gel to give 0.574 g of Compound 1 in neutral form (81% yield) as a white solid.

[0178] 1 H-NMR (300 MHz, DMSO-d6), mixture of atropisomers, δ: 1.06 (d, J=6.9 Hz, 3H), 2.06-2.30 (m, 2H), 2.17 (s, 3H), 2.66-2.8 (m, 1H), 2.8-3.0 (m, 1H), 3.22-3.32 (m, 2H), 3.7-3.8 (m, 6H), 4.06 (m, 2H), 6.00 (q, J=6.9 Hz, 1H), 6.54 (dd, J=8.7, 1.1 Hz, 1H), 6.69 (d, J=1.9 Hz, 1H), 6.90 (d, J=7.8 Hz, 1H), 7.13 (t, J=8.1 Hz, 1H), 7.31 (d, J=8.1 Hz, 1H), 7.40-7.86 (m, 5H), 8.11 (d, J=8.1 Hz, 1H).

[0179] MS (ES+) m/z 577 (M++H).

[0180] The neutral form of Compound 1 (0.574 g, 0.995 mmol) was suspended in 4.49 mL of a 0.21 M aqueous solution of methanesulfonic acid. The resulting suspension was stirred at room temperature for one hour before being filtered through a Rainin nylon filter (0.3 U/13 mm). The filtrate was lyophilized to give 0.368 mg of Compound 1 as the mesylate salt.

[0181] 1 H-NMR (300 MHz, D2O), mixture of atropisomers, δ (water peak at 4.64 ppm, non-corrected): 1.18, 1.36 (2d, J=7.2 Hz, 3H), 2.67, 2.74, 2.80 (3s+1m, 8H), 3.00-3.80 (m, 12H), 6.10-6.24 (m, 2H), 6.54-6.68 (m, 2H), 6.90-7.22 (m, 4H), 7.31 (d, J=8.7 Hz, 1H), 7.44-7.54 (m, 1H), 7.66-7.78 (m, 1H), 8.08 (d, J=8.1 Hz, 1H).

[0182] The compounds of this invention were characterized by Mass Spectrometry and their relative retention times under the following chromatographic protocol:

[0183] System: HP1100

[0184] Column: Zorbax XDB C18 150×3 mm, 3.5 u

[0185] Flow rate: 0.4 ml/min

[0186] UV detn: 240, 254 nm

[0187] Buffer: 0.1M ammonium acetate, pH 6.0

[0188] Organic: acetonitrile

[0189] Gradient:

Time (min)	% buffer	% organic
0	90	10
2	90	10
42	20	80
47	20	80
50	90	10
58	90	10

[0190] For compounds that were purified by HPLC, the following protocol was used:

[0191] Column—Polaris C18, 100×21.2 mm

[0192] Flow rate—20 mL per minute

[0193] Gradient—0-5 min 10% acetonitrile; 5-20 min 10% acetonitrile to 100% acetonitrile; 20-22 min 100% acetonitrile.

[0194] Racemic mixtures (e.g., Compounds 183 and 184), were separated using the following protocol:

[0195] Column—1×25 cm Chirobiotic T (Advanced Separation Technologies, NJ)

[0196] Flow rate—3 mL per minute.

[0197] Eluent—100:0.2:0.1 methanol:acetic acid:triethylamine (isocratic).

[0198] Retention time for Compound 183: 14.5 (±0.5) mins; for Compound 184: 18 (±0.5) minutes. 23

[0199] 1-(2,4-Dimethoxy-phenyl)-3-(4-fluoro-phenyl)-1-{1-[3-(4-methyl-piperazin-1-yl)-4-oxo-3,4-dihydro-quinazolin-2-yl]-ethyl}-urea (prepared using the above General Procedure, 1 eq.) was dissolved in anhydrous toluene at about 0.1M, and β-chloroethyl chloroformate (2.5 eq.) was added. Heating at 100° C. was continued until the reaction was complete (more chloroformate was added if needed as indicated by monitoring consumption of starting material by TLC). The solvent was removed in vacuo, and the crude chloroethyl carbamate was dissolved in methanol at a concentration of about 0.1 M aqueous HCl (1 N; {fraction (1/10)} of the volume of methanol) was added and the solution was stirred at room temperature for 1 hour (monitoring by TLC). When no intermediate carbamate remained, the solvent was partially removed in vacuo. The residue was partitioned between ethyl acetate and dilute aqueous NaOH (pH<8.5). The organic phase was washed with brine and dried over anhydrous sodium sulfate to give the free piperazine (MS 547 (M+H); RT 26.7 minutes). 24

[0200] To a mixture of Compound 46 (55 mg, 0.10 mmol) and potassium carbonate (42 mg, 0.30 mmol) in DMF (3 mL) was added ethyl chloroformate (19 μL, 0.20 mmol) and the mixture was stirred at room temperature for 3 hours. The mixture was then partitioned between ethyl acetate and water. The organic layer was concentrated and purified by silica gel chromatography eluting with 0.5% methanol/dichloromethane), to give Compound 47 (57 mg; MS 629 (M+H); RT 38.0 minutes). 25

[0201] A mixture of Compound 110 (0.44 g, 0.67 mmol), dichloromethane (5 mL) and trifluoroacetic acid (2 mL) was stirred at room temperature for 16 hours. The mixture was then concentrated and purified by silica gel chromatography eluting with 10% methanol/dichloromethane), to give the desired free acid (0.37 g).

[0202] To a solution of the free acid (0.36 g, 0.60 mmol) and N-hydroxysuccinimide (0.07 g, 0.9 mmol) in ethyl acetate (10 mL) was added a solution of DCC (0.12 g, 0.9 mmol) in ethyl acetate (0.5 mL) at 0° C. After stirring for 3 hr, the mixture was then placed in a freezer for 16 hours after which the precipitate that formed was removed by filtration. The filtrate was concentrated to give the crude N-hydroxysuccinate ester (0.45 g), which was used without further purification.

[0203] A solution of the N-hydroxysuccinate ester (92 mg, 0.13 mmol) and ethanolamine (24 mg, 0.39 mmol) in THF (10 mL) was stirred at room temperature for 16 hours. The mixture was concentrated and partitioned between ethyl acetate and water. The organic layer was concentrated and the residue was purified by silica gel chromatography, eluting with 3% methanol/dichloromethane), to give Compound 48 (39 mg; MS 648 (M+H); RT 28.6 minutes). 26

[0204] To a solution of Compound 46 (46 mg, 0.08 mmol) in 1,2-dichloroethane was added diisopropylethylamine (31 mg, 0.24 mmol) and 4-nitrophenyl chloroformate (32 mg, 0.16 mmol). The mixture was stirred at room temperature for 16 hours after which the solvent was removed. The residue was dissolved in 70% aqueous ethylamine (2.5 mL), stirred at room temperature for 16 hours and extracted with ethyl acetate. The organic extract was concentrated and purified by silica gel chromatography, eluting with 0.5% methanol/dichloromethane), to give Compound 49 (30 mg; MS 618(M+H); RT 33.1 minutes). 27

[0205] To a solution of Compound 46 (0.21 g, 0.38 mmol) in THF (10 mL) were sequentially added triethylamine (80 μL, 0.57 mmol) and chloroacetyl chloride (37 μL, 0.47 mmol) at 0° C., and the mixture was stirred for 30 min. Bromine (0.089 mL, 1.7 mmol) in acetic acid (5 mL) was added dropwise. The mixture was partitioned between ethyl acetate and brine. The organic layer was concentrated to give the α-chloro-acetamide intermediate (0.22 g).

[0206] The above intermediate (20 mg, 0.03 mmol) and pyridine (3 μL, 0.035 mmol) in acetonitrile were stirred at 50° C. for 2 days. The mixture was concentrated to give Compound 50 (22 mg) as a light brown solid (MS 702(M+H); RT 28.6 minutes). 28

[0207] A mixture of Compound 46 (0.27 g, 0.49 mmol), ethyl 4-bromobutyrate (0.14 g, 0.74 mmol) and potassium carbonate (0.17 g, 1.2 mmol) in DMF (5 mL) was stirred at room temperature for 2 days. The reaction mixture was diluted with water and extracted with ethyl acetate three times. The organic extracts were combined, washed with brine and concentrated. The residue was purified by silica gel chromatography, eluting with 1% to 3% methanol/dichloromethane, to give Compound 51 (0.29 g; MS 661(M+H); RT 36.2 minutes). 29

[0208] A mixture of Compound 51 (0.28 g, 0.42 mmol) and lithium hydroxide (36 mg, 0.85 mmol) in ethanol (20 mL) was stirred at room temperature for 16 hours. The reaction mixture was concentrated and partitioned between ethyl acetate and 5% hydrochloric acid. The organic layer was washed with brine and concentrated to give Compound 52 (0.26 g; MS 633(M+H); RT 24.4 minutes). 30

[0209] A mixture of Compound 46 (33 mg, 0.06 mmol) and BOC-L-proline N-hydroxysuccinimide ester (0.14 g, 0.74 mmol) in THF (2 mL) was stirred at 40° C. for 8 hours and then at room temperature for 16 hours. The reaction mixture was concentrated and the residue was purified by silica gel chromatography, eluting with 1% to 3% methanol/dichloromethane), to give Compound 53 (40 mg; MS 744(M+H); RT 37.3 minutes). 31

[0210] A mixture of Compound 53 (36 mg, 0.05 mmol), dichloromethane (1 .5 mL) and trifluoroacetic acid (0.2 mL) was stirred at room temperature for 3 hours and then concentrated to dryness to give Compound 54 as a TFA salt (39 mg; MS 644(M+H); RT 27.7 minutes). 32

[0211] To a solution of Boc-Gly (36 mg, 0.2 mmol), 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide (39 mg, 0.2 mmol) and 1-hydroxybenzotriazole (27 mg, 0.2 mmol) in 2 mL of anhydrous DMF was added Compound 46 (36 mg, 0.066 mmol). The resulting mixture was stirred for 48 hours at room temperature. After the addition of 4 mL of saturated aqueous NH4Cl, the mixture was extracted twice with 4 mL of ethyl acetate. The combined organic layers were washed with saturated aqueous NaHCO3 and brine. The organic was dried with sodium sulfate and concentrated to dryness. The crude material was purified by HPLC to give 21 mg of Compound 55 (MS 705(M+H); RT 37.2 minutes). 33

[0212] 2-Bromoethylchloroformate (117 uL, 1.088 mmol) was added to a solution of Compound 46 (496 mg, 0.906 mmol) in anhydrous dichloromethane and the reaction mixture was stirred at 45° C for 12 hours. Saturated aqueous NaHCO3 was added and the mixture was extracted repeatedly with dichloromethane. The combined dichloromethane fractions were dried over anhydrous sodium sulfate and concentrated to dryness. The crude material was purified by flash chromatography, eluting with 30% EtOAc/hexane, to give the intermediate bromide (409 mg).

[0213] A mixture of the above intermediate (10 mg, 0.015 mmol) and 4-hydroxypyridine (2.9 mg, 0.03 mmol) in DMF was heated at 80° C. for 20 hours. The crude mixture was purified by HPLC to give the Compound 56 (MS 713(M+H); RT 27.9 minutes).

[0214] Compound 57 34

[0215] A solution of Compound 46 (43 mg, 0.78 mmol) and Et3N (11 μL, 0.078 mmol) in ClCH2CH2Cl (1 mL) was added slowly to triphosgene (8 mg, 0.026 mmol) at 0° C. under N2. After stirring at room temperature for 10 min, a solution of morpholine (0.78 mmol) and Et3N (11 μL, 0.078 mmol) was added. After stirring 1.5 hours at room temperature, saturated aqueous NaHCO3 was added, the mixture was extracted with CH2Cl2 (3×), and the combined extracts were washed with brine, dried over anhydrous Na2SO4 and concentrated. Purification by preparative plate chromatography (5% MeOH/CH2Cl2) gave Compound 57 (MS 660 (M+H); RT 33.0 minutes).

[0216] The following table provides other exemplary compounds of this invention and methods for their synthesis. Neither the compounds nor the syntheses are intended, nor are they to be construed, as limiting the scope of this invention in any manner whatsoever.

TABLE 1
		MS
		diagnostic
Compound	Structure	peak	RT (min)	Method of synthesis	Differing reagents, starting materials
58	35	579/581 (M + H)	25.8	as Compound 1	3-amino-6-chloropyridazine +triphosgene
59	36	558 (M + H)	27.4	as Compound 1	2-amino-5-methylpyridine +triphosgene
60	37	531 (M + H)	32.5	as Compound 1	m-anisidine, 4-fluorophenylisocyanate
61	38	591 (M + H)	30.3	as Compound 1	3,4,5-trimethoxyaniline, 4-fluorophenylisocyanate
62	39	537 (M + H)	32.0	as Compound 1	2,4-difluoroaniline, 4-fluorophenylisocyanate
63	40	579 (M + H)	27.8	as Compound 1	2-amino-6-fluoro-benzoic acid, 4-fluorophenylisocyanate
64	41	597 (M + H)	31.8	as Compound 1	2-amino-4,5-difluorobenzoic acid, 4-fluorophenylisocyanate
65	42	613/615 (M + H)	35.1	as Compound 1	2-amino-4,5-difluorobenzoic acid, 4-chlorophenylisocyanate
66	43	596 (M + H)	33.8	as Compound 1	2-amino-5-chloro-benzoic acid, 4-fluorophenylisocyanate
67	44	579 (M + H)	31.0	as Compound 1	2-amino-5-fluoro-benzoic acid, 4-fluorophenylisocyanate
68	45	555 (M + H)	34.0	as Compound 1	2-amino-5-benzoic acid, 2,4-difluoroaniline 4-fluorophenylisocyanate
69	46	591/593 (M + H)	34.8	as Compound 1	2-amino-5-methyl-benzoic acid, 4-chlorophenylisocyanate
70	47	575 (M + H)	31.3	as Compound 1	2-amino-5-methyl-benzoic acid, 4-fluorophenylisocyanate
71	48	625 (M + H)	37.4	as Compound 1	2-amino-5-methyl-benzoic acid, 4-trifluorophenylisocyanate
72	49	633 (M + H)	29.6	as Compound 1	2-amino-5-methyl-benzoic acid, 4-fluorophenylisocyanate
73	50	591 (M + H)	27.7	as Compound 1	2-amino-5-methyl-benzoic acid, 4-fluorophenylisocyanate
74	51	607/609 (M + H)	32.8	as Compound 1	2-amino-5-methyl-benzoic acid, 4-chlorophenylisocyanate
75	52	645/647 (M + H)	38.1	as Compound 1	2-amino-4-chloro-benzoic acid, 4-trifluorophenylisocyanate
76	53	611/613/615 (M + H)	35.4	as Compound 1	2-amino-4-chloro-benzoic acid, 4-chlorophenylisocyanate
77	54	595/597 (M + H)	31.8	as Compound 1	2-amino-4-chloro-benzoic acid, 4-fluorophenylisocyanate
78	55	591/593 (M + H)	33.2	as Compound 1	2-amino-4-chloro-benzoic acid, 4-methylphenylisocyanate
79	56	586 (M + H)	29.5	as Compound 1	2-amino-4-cyano-benzoic acid, 4-fluorophenylisocyanate
80	57	619 (M + H)	29.9	as Compound 1	2-aminoterephthalic acid monomethyl ester, 4-fluorophenylisocyanate
81	58	579 (M + H)	30.2	as Compound 1	2-amino-4-fluoro-benzoic acid, 4-fluorophenylisocyanate
82	59	591 (M + H)	27.8	as Compound 1	2-amino-3-methoxy-benzoic acid, 4-fluorophenylisocyanate
83	60	607/609 (M + H)	31.2	as Compound 1	2-amino-3-methoxy-benzoic acid, 4-chlorophenylisocyanate
84	61	577 (M + H)	23.6	from Compound 72, using method as for Compound 52
85	62	647 (M + H)	42.2	as Compound 47	di-tert-butyl dicarbonate 4-fluorophenylisocyanate
86	63	663/665 (M + H)	45.5	from Compound 1, as for Compound 85
87	64	648 (M + H)	43.8	as Compound 85	2,6-Dimethoxy-pyridin-3-ylamine
88	65	629 (M + H)	42.3	as Compound 85	Phenyl isocyanate
89	66	647 (M + H)	43.4	as Compound 47	3-fluorophenylisocyanate
90	67	623 (M + H)	43.3	as Compound 85	2,4-difluoroaniline
91	68	668/670/687 (M + H)	45.3	as Compound 47	2-amino-5-chloro-benzoic acid, 3-chlorophenylisocyanate
92	69	654/656 (M + H)	42.1	as Compound 47	2-amino-5-chloro-benzoic acid
93	70	665 (M + H)	43.6	as Compound 85	2-amino-5-fluoro-benzoic acid
94	71	644 (M + H)	37.8	as Compound 47	2-amino-4-benzoic acid(from 4- methylbenzonitrile, via nitration, methyl oxidation, and NO2 reduction)
95	72	649 (M + H)	37.1	as Compound 47	2-amino-3-methoxy-benzoic acid
96	73	665/668 (M + H)	39.7	as Compound 47	2-amino-3-methoxy-benzoic acid, 4-chlorophenylisocyanate
97	74	686 (M + H)	31.5	as Compound 56	imidazole
98	75	689 (M + H)	30.0	as Compound 56	pyrrolidine
99	76	705 (M + H)	27.7	as Compound 56	3-pyrrolidinol
100	77	703 (M + H)	31.5	as Compound 56	piperidine
101	78	705 (M + H)	33.0	as Compound 56	morpholine
102	79	718 (M + H)	30.0	as Compound 56	1-methyl-piperazine
103	80	721 (M + H)	37.4	as Compound 56	thiomorpholine
104	81	644 (M + H)	35.3	as Compound 56	potassium cyanide
105	82	735 (M + H)	36.2	as Compound 56	2-mercapto-1,3,4-thiadiazole with potassium carbonate (1.5 eq)
106	83	718 (M + H)	32.7	as Compound 56	2-mercapto imidazole with potassium carbonate (1.5 eq)
107	84	732 (M + H)	34.7	as Compound 56	2-mercapto-1-methyl imidazole with potassium carbonate (1.5 eq)
108	85	717 (M + H)	33.6	as Compound 56	succinimide with potassium carbonate (1.5 eq)
109	86	719 (M + H)	31.7	as Compound 56	2-amino-1,3,4-thiadiazole with potassium carbonate (1.5 eq)
110	87	661 (M + H)	40.8	as Compound 51	tert-butyl bromoacetate
111	88	604 (M + H)	29.8	as Compound 51	iodoacetamide
112	89	674 (M + H)	31.5	as Compound 51	N-(iodoacetyl)morpholine
113	90	673 (M + H)	31.2	as Compound 51	1-ethoxycarbonyl-4-aminopiperidine, N-(iodoacetyl)morpholine
114	91	644 (M + H)	32.4	as Compound 51	4-methoxyaniline, N-(iodoacetyl)morpholine
115	92	690/692 (M + H)	34.4	as Compound 51	3-chlorophenylisocyanate, N-(iodoacetyl)morpholine
116	93	656 (M + H)	31.0	as Compound 51	phenylisocyanate, N-(iodoacetyl)morpholine
117	94	658 (M + H)	32.5	as Compound 48	pyrrolidine
118	95	672 (M + H)	36.2	as Compound 48	piperidine
119	96	690 (M + H)	35.7	as Compound 48	thiomorpholine
120	97	687 (M + H)	29.3	as Compound 48	1-methyl-piperazine
121	98	632 (M + H)	31.1	as Compound 48	N,N-dimethylamine
122	99	692 (M + H)	33.0	as Compound 51	2-amino-5-fluoro-benzoic acid, N-(iodoacetyl)morpholine
123	100	563/565 (M + H)	28.6	from Compound 1, using the method as for Compound 46
124	101	641/643 (M + H)	40.0	from Compound 1, using methods as for Compounds 46 and 47	methanesulfonyl chloride
125	102	643 (M + H)	36.4	as Compound 47	2-amino-5-fluoro-benzoic acid, methanesulfonyl chloride
126	103	607 (M + H)	34.9	as Compound 47	phenylisocyanate, methanesulfonyl chloride
127	104	565 (M + H)	27.2	as Compound 46	2-amino-5-fluoro-benzoic acide
128	105	529 (M + H)	25.6	as Compound 46	phenylisocyanate
129	106	547 (M + H)	27.1	as Compound 46	3-fluorophenylisocyanate
130	107	626 (M + H)	36.5	as Compound 47	2,6-Dimethoxy-pyridin-3-ylamine, methanesulfonyl chloride
131	108	673 (M + H)	31.8	as Compound 50	1-ethoxycarbonyl-4-aminopiperidine, morpholine
132	109	686 (M + H)	27.1	as Compound 50	1-ethoxycarbonyl-4-aminopiperidine, 1-methyl-piperazine
133	110	590 (M + H)	28.8	as Compound 49	ammonia
134	111	635 (M + H)	28.4	as Compound 49	2,6-Dimethoxy-pyridin-3-ylamine, 2-aminoethanol
135	112	649 (M + H)	30.5	as Compound 49	2,6-Dimethoxy-pyridin-3-ylamine, 2-methoxyethylamine
136	113	634 (M + H)	28.1	as Compound 49	2-aminoethanol
137	114	674 (M + H)	31.0	as Compound 50	morpholine
138	115	687 (M + H)	27.8	as Compound 50	1-methyl-piperazine
139	116	675 (M + H)	32.6	as Compound 50	2,6-Dimethoxy-pyridin-3-ylamine, morpholine
140	117	673 (M + H)	25.4	as Compound 50	piperazine
141	118	655 (M + H)	30.0	as Compound 50	imidazole
142	119	614 (M + H)	33.2	as Compound 50	potassium cyanide
143	120	659 (M + H)	28.5	as Compound 50	pyrrolidine
144	121	675 (M + H)	26.6	as Compound 50	3-pyrrolidinol
145	122	673 (M + H)	30.6	as Compound 50	piperidine
146	123	691 (M + H)	35.7	as Compound 50	thiomorpholine
147	124	689 (M + H)	26.9	as Compound 50	4-hydroxypiperidine
148	125	683 (M + H)	27.6	as Compound 50	4-hydroxypyridine
149	126	656 (M + H)	28.0	as Compound 50	1,2,4-triazole with triethylamine (1.5 eq)
150	127	686 (M + H)	31.2	as Compound 50	succinimide with triethylamine (1.5 eq)
151	128	726/728 (M + H)	26.3	from the acid analogous to Compound 52	4-chlorophenylisocyanate; methanesulfonamide, using the coupling method described for Compound 55
152	129	663 (M + H)	31.6	as Compound 53	2-(2-methoxyethoxy)acetyl chloride
153	130	707 (M + H)	31.5	as Compound 53	2-(2-Methoxyethoxy)ethoxy]acetic acid N- hydroxysuccinimide ester
154	131	664 (M + H)	32.9	as Compound 152	2,6-Dimethoxy-pyridin-3-ylamine
155	132	655 (M + H)	27.7	as Compound 53	4-imidazoleacetic acid N-hydroxysuccinimide ester
156	133	743 (M + H) 765 (M + Na)	38.1	as Compound 53	1-ethoxycarbonyl-4-aminopiperidine, N-t-BOC-D- proline(activated with N-hydroxy succinimide)
157	134	645 (M + H)	28.5	as Compound 54	2,6-Dimethoxy-pyridin-3-ylamine
158	135	680 (M + H)	29.7	as Compound 54	2-amino-4,5-difluorobenzoic acid
159	136	644 (M + H)	27.0	as Compound 54	BOC-D-proline N-hydroxysuccinimide ester
160	137	643 (M + H)	28.1	as Compound 54	1-ethoxycarbonyl-4-aminopiperidine
161	138	673 (M + H)	29.2	as Compound 53	2-amino-4-fluoro-benzoic acid, 4-imidazoleacetic acid N-hydroxysuccinimide ester
162	139	670 (M + H)	29.2	as Compound 53	1-methyl-4-imidazole acetic acid N- hydroxysuccinimide ester
163	140	719 (M + H)	36.9	as Compound 55	Boc-beta-alanine
164	141	719 (M + H)	37.8	as Compound 55	Boc-alanine
165	142	735 (M + H)	33.9	as Compound 55	Boc-serine
166	143	719 (M + H)	37.8	as Compound 55	Boc-sarcosine
167	144	759 (M + H)	39.4	as Compound 55	Boc-L-beta-homoproline
168	145	759 (M + H)	39.3	as Compound 57	1-ethoxycarbonylaminopiperidine 4-carboxylic acid N-hydroxysuccinimide ester
169	146	703 (M + H)	28.5	as Compound 49	2-Morpholin-4-yl-ethylamine
170	147	661 (M + H)	26.1	as Compound 49	N,N-dimethylethylenediamine
171	148	687 (M + H)	26.9	as Compound 49	2-Pyrrolidin-1-yl-ethylamine
172	149	702 (M + H)	25.0	as Compound 49	2-Piperazin-1-yl-ethylamine
173	150	616 (M + H)	29.5	as Compound 46	2-bromoethyl isocyanate
174	151	606/608 (M + H)	31.2	as Compound 49	3-chlorophenylisocyanate, ammonia
175	152	637 (M + H)	36.8	as Compound 46	chloroethysulfonyl chloride
176	153	560 (M + H)	28.3	as Compound 51	1-ethoxycarbonyl-4-aminopiperidine; following carbamate hydrolysis with 6N HCl, alkylation with dimethyl sulfate
177	154	646 (M + H)	42.8	as Compound 51	1-ethoxycarbonyl-4-aminopiperidine; following carbamate hydrolysis with 6N HCl, acylation with di- tert-butyl dicarbonate
178	155	662 (M + H)	31.8	as Compound 51	1-ethoxycarbonyl-4-aminopiperidine; following carbamate hydrolysis with 6N HCl, acylation with 2- (2-methoxyethoxy)acetyl chloride
179	156	772 (M + H)	27.8	from the acid analogous to Compound 52	Phenylsulfonyl amide
180	157	710 (M + H)	24.6	from the acid analogous to Compound 52	Methanesulfonamide
181	158	657 (M + H)	25.2	from the acid analogous to Compound 52	Cyanamide
182	159	764 (M + H)	29.7	from the acid analogous to Compound 52	Trifluoromethanesulfonamide
183	160	644 (M + H)	27.2	from Compound 54	HPLC separation
184	161	644 (M + H)	27.1	from Compound 54	HPLC separation
185	162	604 (M + H)	25.9	from Compound 55 by treatment with TFA as for Compound 110
186	163	618 (M + H)	26.0	from Compound 163 by treatment with TFA as for Compound 110
187	164	618 (M + H)	26.4	from Compound 164 by treatment with TFA as for Compound 110
188	165	634 (M + H)	35.3	from Compound 165, by treatment with TFA as for Compound 110
189	166	618 (M + H)	26.6	from Compound 166 by treatment with TFA as for Compound 110
190	167	659 (M + H)	27.0	from Compound 167 by treatment with TFA as for Compound 110
191	168	701 (M + H)	28.9	from Compound 140	formic acid + acetic anhydride
192	169	677 (M + H)	32.6	from Compound 185	methyl chloroformate
193	170	677 (M + H)	32.6	from Compound 187	methyl chloroformate
194	171	708 (M + H)	33.6	from Compound 175	pyrrolidine
195	172	546 (M + H)	26.6	from Compound 46	1-ethoxycarbonyl-4-aminopiperidine
196	173	672 (M + H)	33.6	from Compound 46	2-Chloro-1-pyrrolidin-1-yl-propan-1-one
197	174	658 (M + H)	25.0	from Compound 168 by treatment with TFA as for Compound 110
198	175	645 (M + H)	26.4	as Compound 54	2,6-Dimethoxy-pyridin-3-ylamine; BOC-D-proline N-hydroxysuccinimide ester
199	176	760 (M + H)	38.9	as Compound 57	1-(t-butyloxycarbonyl)piperazine
200	177	660 (M + H)	25.0	from Compound 199 by treatment with TFA as for Compound 110
201	178	676 (M + H)	30.7	as Compound 50	2-amino-5-fluoropyridine +triphosgene
202	179	662 (M + H)	33.4	as Compound 198	Triphosgene + morpholine
203	180	755 (M + H)	38.7	as Compound 114	2,4-Bis-cyclopropylmethoxy-phenylamine
204	181	650 (M + H)	29.7	as Compound 51	N-(3-Amino-phenyl)-methanesulfonamide; cyclopropanecarbonyl chloride
205	182	623 (M + H)	35.6	as Compound 204	3-[1,2,3]Triazol-2-yl-phenylamine
206	183	725 (M + H)	723.8	as Compound 54	2,4-Bis-cyclopropylmethoxy-phenylamine
207	184	628 (M + H)	31.12	as Compound 204	1-(3-Amino-4-methoxy-phenyl)-ethanone
208	185	652 (M + H)	27.22	as Compound 54	3-[1,2,3]Triazol-2-yl-phenylamine
209	186	602 (M + H)	30.9	as Compound 51	Bromomethyl-cycloprolpane
210	187	660 (M + H)	24.7	as Compound 204 followed by treatment with TFA as for Compound 110	3-(t-butoxycarbonylamino)pyrrolidine
211	188	674 (M + H)	24.9	as Compound 57 followed by treatment with TFA as for Compound 110	4-(t-butoxycarbonylamino)piperidine
212	189	687 (M + H)	29.3	as Compound 55	(N-acetyl)proline

[0217] Pharmaceutical Compositions and Modes of Administration

[0218] An efflux pump inhibitory compound, or salt of prodrug thereof, and an anti-fungal agent may be administered to a patient serially or simultaneously. If serial administration is contemplated, the presently preferred approach is to administer the compound of this invention first. This permits the compound to inhibit the efflux pump(s) of the target fungal cells before the anti-fungal agent is administered, which should result in a substantially lower dosage of the anti-fungal agent being required since the fungal cells will not be able to excrete the agent. By “simultaneous” administration is meant that a compound of this invention and an anti-fungal agent are administered to a patient at essentially the same time. This can be accomplished by administering the compound herein and the anti-fungal agent separately, as in the case of two separate tablets or capsules, separate I.V. drips, or separate injections administered one immediately after the other, which, as used herein, constitutes “simultaneously.” In a presently preferred embodiment, “simultaneously” means that the compound of this invention is prepared as a homogeneous composition with an anti-fungal agent and that composition is administered to the patient. In the alternative, a compound of this invention may be administered to a patient first and then, after it has had the opportunity to inhibit the efflux pump of the fungicidal cells, the anti-fungal agent is administered. Since the fungal cells will no longer be able to excrete the anti-fungal agent via the effluix pump, the agent will accumulate in the cells in sufficient concentration to inhibit the cells and treat the infection.

[0219] A compound of the present invention, a prodrug thereof or a physiologically acceptable salt of either the compound or its prodrug, can be administered as such to a patient or as a pharmaceutical compositions in which the compounds are mixed with suitable carriers or excipient(s). Techniques for formulation and administration of drugs may be found in Remington's Pharmacological Sciences, Mack Publishing Co., Easton, Pa., latest edition.

[0220] Suitable routes of administration include, without limitation, oral, rectal, vaginal, transmucosal, intramuscular, subcutaneous, intramedullary, intrathecal, direct intraventricular, intravenous, intravitreal, intraperitoneal, intranasal, or intraocular. The presently preferred routes of administration are oral and parenteral.

[0221] Alternatively, one may administer the compound in a localized topical rather than systemic manner. That is, the homogeneous composition of a compound herein and an anti-fungal agent can be applied directly to the surface of an infected area or injected directly into the infection.

[0222] Pharmaceutical compositions of the present invention may be manufactured by processes well known in the art, e.g., by means of conventional mixing, dissolving, granulating, dragee-making, levigating, emulsifying, encapsulating, entrapping or lyophilizing processes.

[0223] Such pharmaceutical compositions are formulated in conventional manner and may include one or more pharmaceutically acceptable carriers, excipients and/or auxiliaries which facilitate processing of the active compounds into preparations which can be used pharmaceutically. Proper formulation is dependent upon the route of administration chosen.

[0224] For injection, the compounds of the invention may be formulated in aqueous solutions, preferably in physiologically compatible buffers such as Hanks' solution, Ringer's solution, or physiological saline buffer.

[0225] For transmucosal administration, penetrants appropriate to the barrier to be permeated are used in the formulation. Such penetrants are generally known in the art.

[0226] For oral administration, the compounds can be formulated by combining the active ingredients with pharmaceutically acceptable carriers well known in the art. Such carriers enable the compounds of the invention to be formulated as tablets, pills, lozenges, dragees, capsules, liquids, gels, syrups, slurries, suspensions and the like, suitable for oral ingestion. Pharmaceutical preparations for oral use can be made using a solid excipient, optionally grinding the resulting mixture, and processing the mixture of granules, after adding other suitable auxiliaries if desired, to obtain tablets or dragee cores. Useful excipients are, in particular, fillers such as sugars, including lactose, sucrose, mannitol, or sorbitol, cellulose preparations such as, for example, maize starch, wheat starch, rice starch and potato starch and other materials such as gelatin, gum tragacanth, methyl cellulose, hydroxypropylmethylcellulose, sodium carboxymethylcellulose, and/or polyvinylpyrrolidone (PVP). Disintegrating agents may also be added, such as cross-linked polyvinyl pyrrolidone, agar, or alginic acid. A salt such as sodium alginate may also be used.

[0227] Dragee cores are often provided with suitable coatings. For this purpose, concentrated sugar solutions may be used which may optionally contain gum arabic, talc, polyvinyl pyrrolidone, carbopol gel, polyethylene glycol, and/or titanium dioxide, lacquer solutions, and suitable organic solvents or solvent mixtures. Dyestuffs or pigments may be added to the tablets or dragee coatings to identify the particular compounds in that composition and/or their dosages.

[0228] Pharmaceutical formulations which can be used orally include push-fit capsules made of gelatin, as well as soft, sealed capsules made of gelatin and a plasticizer, such as glycerol or sorbitol. The push-fit capsules can contain the active ingredients in admixture with a filler such as lactose, a binder such as starch, and/or a lubricant such as talc or magnesium stearate and, optionally, stabilizers. In soft capsules, the active compounds may be dissolved or suspended in suitable liquids, such as fatty oils, liquid paraffin, or liquid polyethylene glycols. Stabilizers may be added in these formulations, also.

[0229] For administration by inhalation, the compounds for use according to the present invention are conveniently delivered in the form of an aerosol spray using a pressurized pack or a nebulizer and a suitable propellant, e.g., without limitation, dichlorodifluoromethane, trichlorofluoromethane, dichlorotetrafluoroethane or carbon dioxide. In the case of a pressurized aerosol, the dosage may be controlled by providing a valve that delivers a metered amount. Capsules and cartridges of, for example, gelatin for use in an inhaler or insufflator may be formulated containing a powder mix of the compound and a suitable powder base such as lactose or starch.

[0230] The compounds may also be formulated for parenteral administration. Formulations for parenteral injection may be in unit dosage form, e.g., in single-dose ampoules, or in multi-dose containers. The compositions may take such forms as suspensions, solutions or emulsions in oily or aqueous vehicles, and may contain formulating materials such as suspending, stabilizing and/or dispersing agents.

[0231] Pharmaceutical compositions for parenteral administration include aqueous solutions of a water soluble form, such as, without limitation, a salt, of the active compound. Or, suspensions of the active compounds may be prepared in a lipophilic vehicle. Suitable lipophilic vehicles include fatty oils such as sesame oil, synthetic fatty acid esters such as ethyl oleate and triglycerides, or materials such as liposomes. Aqueous injection suspensions may contain substances which increase the viscosity of the suspension, such as sodium carboxymethyl cellulose, sorbitol, or dextran. Optionally, the suspension may also contain suitable stabilizers and/or agents that increase the solubility of the compounds to allow for the preparation of highly concentrated solutions.

[0232] Alternatively, the active ingredient may be in powder form for constitution with a suitable vehicle, e.g., sterile, pyrogen-free water.

[0233] The compounds may also be formulated in rectal compositions such as suppositories or retention enemas, using, e.g., conventional suppository bases such as cocoa butter or other glycerides.

[0234] The compounds may also be formulated as depot preparations. Such long acting formulations may be administered by implantation (for example, subcutaneously or intramuscularly) or by intramuscular injection. A compound of this invention may be formulated for this route of administration with suitable hydrophobic materials (for instance, in an emulsion with a pharmacologically acceptable oil), with ion exchange resins, or as a sparingly soluble derivative such as, without limitation, a sparingly soluble salt.

[0235] Delivery systems for hydrophobic pharmaceutical compounds include, without limitation, liposomes and emulsions. These are well known examples of delivery vehicles or carriers for hydrophobic drugs. In addition, certain organic solvents such as dimethylsulfoxide may be employed, although often at the cost of greater toxicity.

[0236] The compounds may be delivered using a sustained-release system, such as semipermeable matrices of solid hydrophobic polymers. Sustained-release materials and methods are well known to those skilled in the art. Sustained-release capsules may, depending on their chemical nature, release the compounds for a relatively short period of time, a few days perhaps even a few hours, or over very long periods of time such as 100 days or more.

[0237] The pharmaceutical compositions herein may comprise suitable solid or gel phase carriers or excipients. Examples of such carriers or excipients include, but are not limited to, calcium carbonate, calcium phosphate, various sugars, starches, cellulose derivatives, gelatin, and polymers such as polyethylene glycols.

[0238] Dosage

[0239] Determination of a dosage that will result in a therapeutically effective amount of a fungal agent and compound of this invention being delivered to a patient will require assessment of such parameters as, without limitation, the age, gender, weight and physical condition of the patient as well as the severity of the infection, route of administration and response to previous treatments, if any. All of these are well within the knowledge and expertise of the treating physician.

[0240] In addition to the above considerations, it will be understood that the maximum permissible dose of known anti-fungal agents can be readily found in the pharmacological literature. The effect of various quantities of a compound of this invention on the amount of two conventional anti-fungal agents required to treat a fungal infection are disclosed herein. If other anti-fungal agents and/or other compounds are selected for use, the effect of various quantities of the compound on the efficacy of the anti-fungal agent can be determined without undue experimentation using the methods described herein.

[0241] While it may on occasion be desirable, even necessary, to treat a patient with massive doses of an anti-fungal agent and a compound of this invention, generally, it is preferred to use the least amount of the anti-fungal compound and of the compound herein that achieves the desired therapeutic or prophylactic effect. This determination is likewise well within the capability of the treating physician.

[0242] Packaging

[0243] The compositions may, if desired, be presented in a pack or dispenser device, such as an FDA approved kit, which may contain one or more unit dosage forms containing the active ingredient. The pack may for example comprise metal or plastic foil, such as a blister pack. The pack or dispenser device may be accompanied by instructions for administration. The pack or dispenser may also be accompanied by a notice associated with the container in a form prescribed by a governmental agency regulating the manufacture, use or sale of pharmaceuticals, which notice is reflective of approval by the agency of the form of the compositions or of human or veterinary administration. Such notice, for example, may be of the labeling approved by the U.S. Food and Drug Administration for prescription drugs or of an approved product insert. Compositions comprising a compound of the invention formulated in a compatible pharmaceutical carrier may also be prepared, placed in an appropriate container, and labeled for treatment of an indicated condition. Suitable conditions indicated on the label may include treatment of a fungal infections caused by particular species of fungus and the like.

[0244] Biological Activity

[0245] The activity of test compounds of this invention in combination with an anti-fungal were assessed using a checkerboard assay and the broth microdilution protocol recommended by NCCLS Documents M27-A, Vol. 17, No. 9, June 1997, entitled, “Reference Method for Broth Dilution Anti-fungal Susceptibility Testing of Yeasts, Approved Standard,” and NCCLS Document M38-P, Vol. 18, No.13, November 1998, entitled, “Reference Method for Broth Dilution Anti-fungal Susceptibility Testing of Conidium/Forming Filamentous Fungi; Proposed Standard.” The test organisms used are Candida albicans YEM15 (over-expressing the CDR1 and CDR2 pumps) and C. glabrata YEM19 (over-expressing the CgCDR1 and CgCDR2 pumps).

[0246] Multiple dilutions of a known antifungal and a compound of this invention, are tested alone and in combination at concentrations equal to, above and below the MIC, minimum inhibitory concentration, of the anti-fungal. Unless specifically stated to be otherwise, MIC's are usually reported as the amount of a compound necessary to achieve 80% of the maximum effect possible with that compound. Thus, for example, for an antifungal agent it would be the concentration of the agent that inhibits 80% of the fungal cells contacted. For instance, the MICs of fluconazole against YEM15 and YEM19 are 64 and 128 ug/ml respectively. The compounds of this invention, most of which are shown to have little or no intrinsic anti-fungal activity, are tested at concentration of from about 4 to about 32 μg/ml.

[0247] Stock solutions of the test compounds are prepared at a concentration of 64-128 μg/ml. Stock solutions are then diluted, according to the needs of a particular assay, in RPMI-1640 with MOPS buffer at 165 mM L-glutamine (Angus Buffers & Biochemicals, catalog no. R63165). Stock solutions can be stored at 4° C. Fluconazole is solubilized according to the instructions of the manufacturers, at a concentration of 10 mg/ml in 100% DMSO. It is then further diluted in RPMI.

[0248] The checkerboard assay is normally performed on microtiter plates. Serial dilutions of the anti-fungal are placed in wells horizontally across the plate resulting in each well in any column of wells having the same concentration of the anti-fungal. The test compound is serially diluted in each column of wells resulting in the rows of wells each containing the same concentration of the test compound. Thus, each well in the array contains a unique combination of anti-fungal and test compound concentrations. Test compounds are examined one per plate.

[0249] The assay is performed in RPMI using a final fungal inoculum of 1 to 5×103 CFU/ml (from an early-log phase culture). Microtiter plates are incubated for 48 h at 35° C. and are read using a microtiter plate reader (Molecular Devices) at 650 nm.

[0250] Tables 2 and 3 show potentiation of an anti-fungal agent, as manifested by a reduction in the MIC of the anti-fungal, in the presence, as contrasted to the absence, of an efflux pump inhibitor of this invention.

TABLE 2
Potentiation of fluconazole vs. C. albicans*
Compound
Number	MIC (μg/ml)	MPC8 (μg/ml)**
47	>32	0.25
48	>32	16
49	>32	1
50	>32	32
51	>32	1
53	>32	4
55	>32	4
56	>32	16
57	>32	1
58	>32	16
60	>32	16
61	>32	8
62	>32	8
63	>32	8
64	>32	0.125
65	32	0.0625
66	>32	0.25
67	>32	1
68	>32	2
69	>32	0.125
70	>32	0.5
71	16	2
72	>32	4
73	>32	0.5
74	>32	0.25
75	16	0.5
76	>32	0.25
77	>32	0.125
78	32	0.25
79	>32	0.5
80	>32	32
81	>32	0.5
82	>32	8
83	>32	4
84	>32	16
85	>32	0.5
86	>32	1
87	>32	0.5
88	>32	1
89	>32	2
90	>32	0.125
91	>32	2
92	>32	4
93	>32	4
94	>32	2
95	>32	32
96	>32	32
97	>32	0.25
98	>32	8
99	>32	16
100	>32	1
101	>32	0.5
102	>32	16
103	>32	1
104	>32	0.25
105	>32	0.5
106	>32	2
107	>32	2
108	>32	2
109	>32	1
110	>32	2
111	>32	1
112	>32	0.25
113	>32	2
114	>32	2
115	>32	1
116	>32	0.5
117	>32	0.125
118	>32	0.0625
119	>32	0.0625
120	>32	8
121	>32	0.125
122	>32	0.125
123	>32	16
124	>32	≦0.03
125	>32	≦0.03
126	>32	0.125
128	>32	32
129	>32	32
130	>32	2
131	>32	4
133	>32	8
134	>32	32
135	>32	4
136	>32	8
137	>32	1
139	>32	2
141	>32	16
142	>32	2
143	>32	4
144	>32	32
145	>32	2
146	>32	0.25
147	>32	16
148	>32	32
151	>32	32
152	>32	0.5
153	>32	2
154	>32	2
155	>32	8
156	>32	4
157	>32	16
158	>32	16
161	>32	32
162	>32	1
163	>32	2
164	>32	2
165	>32	4
166	>32	1
167	>32	2
168	>32	8
173	>32	16
174	>32	0.5
175	>32	≦0.03
176	>32	32
177	>32	4
178	>32	8
179	>32	32
180	>32	32
181	>32	32
191	>32	8
192	>32	1
193	>32	2
194	>32	0.5
195	>32	32
196	>32	0.23
198	>32	32
199	>32	16
201	>32	4
202	>32	0.06
203	>32	4
205	>32	0.25
207	>32	16
209	>32	0.25
210	>32	8
211	>32	32
212	>32	16
*Strain YEM15, over-expressing CDR1 and CDR2 efflux pumps
**MPC8 = concentration of efflux pump inhibitor necessary to reduce the fluconazole MIC 8-fold

[0251]

TABLE 3
Potentiation of fluconazole vs. C. glabrata*
Example
Number	MIC (μg/ml)	MPC8 (μg/ml)
46	>32	32
47	>32	0.5
48	>32	2
49	>32	1
50	>32	4
51	>32	0.25
52	>32	32
53	>32	1
54	>32	4
55	>32	1
56	>32	8
57	>32	1
58	>32	8
59	>32	16
62	>32	32
63	>32	8
64	>32	0.5
65	>32	0.25
66	>32	2
67	>32	2
68	>32	16
69	>32	2
70	>32	4
71	>32	4
72	>32	4
73	>32	2
74	>32	1
75	16	0.5
76	>32	0.5
77	>32	0.5
78	32	0.25
79	>32	2
80	>32	2
81	>32	1
82	>32	8
83	>32	2
84	>32	1
85	>32	0.25
86	>32	2
87	>32	2
88	>32	0.5
89	>32	2
90	>32	4
91	>32	16
93	>32	1
94	>32	0.5
96	>32	8
97	>32	0.5
98	>32	0.5
99	>32	1
100	>32	0.25
101	>32	0.125
102	>32	0.5
103	>32	0.25
104	>32	0.25
105	>32	0.25
106	>32	0.25
107	>32	0.25
108	>32	0.5
109	>32	0.5
110	>32	1
111	>32	4
112	>32	0.25
113	>32	1
114	>32	4
115	>32	2
116	>32	1
117	>32	0.5
118	>32	0.5
119	>32	0.25
120	>32	1
121	>32	1
122	32	0.5
123	>32	32
124	>32	2
125	>32	1
126	>32	4
127	>32	8
128	>32	32
129	>32	32
130	>32	32
131	>32	0.5
132	>32	2
133	>32	16
134	>32	16
135	>32	2
136	>32	2
137	>32	0.5
138	>32	1
139	>32	1
140	>32	2
141	>32	4
142	>32	4
143	>32	1
144	>32	2
145	>32	0.5
146	>32	0.25
147	>32	2
148	>32	16
149	>32	32
150	>32	8
151	>32	32
152	>32	0.5
153	>32	1
154	>32	1
155	>32	1
156	>32	2
157	>32	4
158	>32	2
159	>32	2
160	>32	1
161	>32	4
162	>32	0.5
163	>32	2
164	>32	1
165	>32	2
166	>32	0.5
167	>32	2
168	>32	4
169	>32	1
170	>32	1
171	>32	1
172	>32	4
173	>32	2
174	>32	8
175	>32	1
176	>32	16
177	>32	1
178	>32	2
179	>32	16
180	>32	16
181	>32	16
182	>32	32
183	>32	1
184	>32	32
185	>32	16
186	>32	8
187	>32	4
188	>32	8
189	>32	4
190	>32	0.5
191	>32	2
192	>32	0.5
193	>32	0.25
194	>32	2
195	>32	32
196	>32	0.5
197	>32	4
198	>32	2
199	>32	2
200	>32	16
201	>32	0.5
202	>32	1
203	>32	2
204	>32	16
205	>32	2
206	>32	0.25
207	>32	8
208	>32	32
209	>32	1
210	>32	4
211	>32	8
212	>32	2
*Strain YEM19, over-expressing CgCDR1 and CgCDR2 efflux pumps

CONCLUSION

[0252] The patents and publications referenced herein are indicative of the level of skill of those skilled in the art to which this invention pertains. All such patents and publications are incorporated by reference to the same extent as if each had been separately incorporated by reference.

[0253] While the above description describes particular embodiments and examples illustrating the invention, those skilled in the art will recognize that the invention may be practiced in a variety of alternative ways, for example, by potentiating a variety of other anti-fungal agents that exhibit an efflux pump resistance mechanism. All such variations are within the scope of this invention. Other embodiments of this invention are contained in the following claims.

Claims

1. A compound having the chemical formula:

2. The compound or salt of claim 1, wherein R2 is —CH3.

3. The compound or salt of claim 2, wherein A2, A3, A4, A5 and A6 are carbon.

4. The compound or salt of claim 3, wherein: R7 and R8 are independently selected from the group consisting of —O(1C-4C)alkyl and —OCH2(3C-6C)cycloalkyl; and, R3, R4, R5, R28 and R29 are hydrogen.

5. The compound or salt of claim 4, wherein R7 and R8 are OCH3.

6. The compound or salt of claim 4, wherein R7 and R8 are

7. The compound of salt of claim 5, wherein: A4, A5 and A6 are carbon; R9 is selected from the group consisting of hydrogen and halogen; and, R10 is hydrogen.

8. The compound of salt of claim 7, wherein R9 is fluorine.

9. The compound or salt of claim 2, wherein: A2, A4, A5 and A6 are carbon; and, A3 is nitrogen.

10. The compound or salt of claim 9, wherein: R28 is hydrogen; and, R7 and R8 are selected from the group consisting of —O(1C-4Calkyl) and OCH2(3C-6C)cycloalkyl.

11. The compound or salt of claim 10, wherein R7 and R8 are OCH3.

12. The compound or salt of claim 11, wherein R3-R5 and R10 are hydrogen.

13. The compound or salt of claim 12, wherein R9 is selected from the group consisting of hydrogen and fluorine.

14. The compound or salt of claim 2, wherein A1 is carbon.

15. The compound or salt of claim 14, wherein R3, R4, R5 and R10 are hydrogen.

16. The compound or salt of claim 15, wherein R9 is selected from the group consisting of hydrogen and fluorine.

17. The compound or salt of claim 2, wherein: R6 or R8 is selected from the group consisting of —OCH3 and 203 and, R7is F.

18. The compound or salt of claim 2, wherein: A3 is carbon; R6 or R8 is selected from the group consisting of —OCH3 and 204 and, R29 is —C(O)CH3.

19. The compound or salt of claim 2, wherein R6 or R8 and R7 are

20. The compound or salt of claim 2, wherein: A2 is carbon: and, R28 is —NHSO2CH3.

21. The compound or salt of claim 2, wherein: A2 is carbon; and, R28 is —NHSO2CF3.

22. The compound or salt of claim 2, wherein: A2 is carbon; and, R28 is —SO2CF3.

23. The compound of salt of claim 2, wherein: A2 is carbon; and, 206

24. A method for inhibiting a fungal cell that employs an efflux pump resistance mechanism, comprising contacting the cell with an anti-fungal agent and a compound having the chemical structure:

25. The method of claim 24, wherein the anti-fungal agent is an azole anti-fungal agent.

26. The method of claim 25, wherein the azole fungicide is selected from the group consisting of fluconazole and posaconazole.

27. The method of claim 24, wherein the fungal cell is first contacted with the compound and then with the anti-fungal agent.

28. The method of claim 24, wherein the fungal cell is contacted with the compound and the anti-fungal agent simultaneously.

29. The method of claim 24, wherein the fungal cell is a genus Candida cell.

30. The method of claim 29, wherein the genus Candida cell is selected from the group consisting of C. albicans, C. krusei, C. tropicalis, C. parapsilosis and C. glabrata.

31. The method of claim 24, wherein the fungal cell is a genus Aspergillus cell.

32. The method of claim 31, wherein the genus Aspergillus cell is an Aspergillus fumigatus cell.

33. A method for treating an infection caused by a fungus that employs an efflux pump resistance mechanism, comprising administering to a patient in need thereof a therapeutically effective amount of an anti-fungal agent and a compound having the chemical formula:

34. The method of claim 33, wherein the infection is caused by a genus Candida fungus.

35. The method of claim 34, wherein the Candida fungus is C. albicans, C. krusei, C. tropicalis, C. parapsilosis or C. glabrata.

36. The method of claim 33, wherein the infection is caused by a genus Aspergillus fungus.

37. The method of claim 33, wherein the genus Aspergillus fungus is Aspergillus fumigatus.

38. The method of claim 33, wherein the compound and the anti-fungal agent are administered simultaneously.

39. The method of claim 33, wherein the compound is administered first followed by administration of the anti-fungal agent.

40. A pharmaceutical composition, comprising: a pharmaceutically acceptable carrier or excipient; and, a compound having the chemical structure: 233or a pharmaceutically acceptable salt thereof, wherein: A1, A2, A3, A4, A5 and A6 are independently selected from the group consisting of carbon and nitrogen; R2 is (1C-4C)alkyl; R3, R4, R5, R6, R7, R8, R9, R10, R28 and R29 are independently selected from the group consisting of hydrogen, (1C-4C)alkyl, —CF3, —O(1C-4C)alkyl, —OCH2(3C-6C)cycloalkyl, halo, —OH, —C≡N, —C(O)-(1C-4C)alkyl, —C(O)O-(1C-4C)alkyl, —OC(O)-(1C-4C)alkyl, —NHSO2(1C-4C)alkyl, —NHSO2CF3, —SO2CF3 and 234 provided that, if A2 and/or A3 is nitrogen, R28 and/or R29 do not exist; and, R1 is selected from the group consisting of hydrogen, -(1C-4C)alkyl, -(3C-6C)cycloalkyl, —CH2(3C-6C)cycloalkyl and 235or R1 is —S(O)mR11, wherein: m is 1 or 2; R11 is selected from the group consisting of —NR12R13, (1C -4C)alkyl optionally substituted with an —NR12R13group, (2C-4C)alkenyl, —CF3 and phenyl optionally substituted with one or more entities selected from the group consisting of (1C-4C)alkyl, —OH, —O(1C-4C)alkyl, halo and —C≡N, wherein: R12 and R13 are independently selected from the group consisting of hydrogen, CF3 and (1C-4C)alkyl, or together with the nitrogen to which they are bonded form a cyclic entity selected from the group consisting of: 236A6, A7 and A8 are independently selected from the group consisting of carbon and nitrogen; R14 is selected from the group consisting of hydrogen, -(1C-4C)alkyl, —O(3C-6C)cycloalkyl, —OH, —C≡N, and halo; and, R15 is selected from the group consisting of hydrogen, -(1C-4C)alkyl, —C(O)H, —C(O)O-(1C-4C)alkyl, —C(O)OCH2(3C-6C)cycloalkyl, —C(O)NH-(1C-4C)alkyl, —C(O)NHCH2(3C-6C)cycloalkyl, and —Nt-Boc; or R1is —(CH2)nC(O)R16, wherein: n is 0, 1, 2 or 3; R16 is selected from the group consisting of: hydrogen, -(1C-4C)alkyl, -(3C-6C)cycloalkyl, 237 and 238 wherein: R30 is selected from the group consisting of hydrogen and —C(O)OR31, wherein: R31 is selected from the group consisting of hydrogen and -(1C-4C)alkyl; or, R16 is —OR17, wherein. R17 is selected from the group consisting of hydrogen, —(CH2CH2O)q-(1C-4C)alkyl, and (1C-4C)alkyl optionally substituted with an entity selected from the group consisting of —NR12R13, —C≡N, 239A9 is selected from the group consisting of —NH, —N(1C-4C)alkyl, —NCH2(3C-6C)cycloalkyl, —N(3C-6C)cycloalkyl and sulfur; A10 and A11 are independently selected from the group consisting of carbon and nitrogen; and, q is 1, 2, 3 or 4; or R16 is —NR18R19, wherein: R18 and R19 are independently selected from the group consisting of hydrogen, (1C-4C)alkyl optionally substituted with an entity selected from the group consisting of —O(1C-4C)alkyl, —OH, —C≡N, —NH2, —NH(1C-4C)alkyl, —N((1C-4C)alkyl)2 and —S(O)nR20 or R18 is —C≡N and R19 is hydrogen; wherein: R20 is selected from the group consisting of —NR12R13, (1C-4C)alkyl optionally substituted with an —NR12R13 group, (2C-4C)alkenyl, —CF3 and phenyl optionally substituted with one or more entities selected from the group consisting of (1C-4C)alkyl, —OH, —O(1C-4C)alkyl, halo and —C≡N; n is 1 or 2; or, R18 and R19 together with the nitrogen to which they are bonded form a cyclic entity selected from the group consisting of: 240or R16 is —CH(R21)(CH2)pR22, wherein: p is 0, 1 or 2; R21 is independently selected from the group consisting of hydrogen and (1C-4C)alkyl optionally substituted with an entity selected from the group consisting of —OH, —O(1C-4C)alkyl, —OCH2(3C-6C)cycloalkyl and —C≡N; R22 is —OR23, wherein R23 is selected from the group consisting of hydrogen, —(CH2CH2O)q-(1C-4C)alkyl, —CH2(3C-6C)cycloalkyl and (1C-4C)alkyl optionally substituted with an entity selected from the group consisting of —NR12R13, —C≡N, 241A9 is selected from the group consisting of —NH, —N(1C-4C)alkyl, —N(3C-6C)cycloalkyl, —NCH2(3C-6C)cycloalkyl and sulfur; A10 and A11 are independently selected from the group consisting of carbon and nitrogen; and, q is 1, 2, 3 or 4; or R22 is —NR24R25, wherein R24 and R25 are independently selected from the group consisting of hydrogen, (1C-4C)alkyl and —C(O)OR26, wherein: R26 is independently selected from the group consisting of hydrogen and (1C-4C)alkyl; or, together with the nitrogen to which they are bonded R24 and R25 form an entity selected from the group consisting of: 242wherein J− is a pharmaceutically acceptable anion; or R22 is selected from the group consisting of: 243R16 is selected from the group consisting of: 244R27 is selected from the group consisting of hydrogen, (1C-4C)alkyl, -(3C-6C)cycloalkyl, —CH2(3C-6C)cycloalkyl and —OC(O)O-(1C-4C)alkyl; or R1 is 245 wherein: A12 is selected from the group consisting of —NH, sulfur and oxygen, and, A13, A14 and A15 are independently selected from the group consisting of carbon and nitrogen; wherein: the compound comprises a racemic mixture or a pure enantiomer.

41. The pharmaceutical composition of claim 40, further comprising a therapeutically effective amount of an anti-fungal agent.

42. The pharmaceutical composition of claim 41, wherein the anti-fungal agent is an azole anti-fungal agent.

43. The pharmaceutical composition of claim 42, wherein the azole anti-fungal agent is fluconazole or posaconazole.