N-LINKED UREA OR CARBAMATE OF HETEROCYCLIC THIOESTER HAIR GROWTH COMPOSITIONS AND USES

Abstract: This invention relates to pharmaceutical compositions and methods for treating alopecia and promoting hair growth using N-linked ureas or carbamates of heterocyclic thioesters.

Description: N-LINKED UREA OR CARBAMATE OF HETEROCYCLIC THIOESTER HAIR GROWTH COMPOSITIONS AND USES This application is a continuation-in-part of U.S. Patent Application No. 08/869,426, filed on June 4, 1997, the entire contents of which are herein incorporated by reference. BACKGROUND OF THE INVENTION 1. Field of Invention This invention relates to pharmaceutical compositions and methods for treating alopecia and promoting hair growth using low molecular weight, small molecule N-linked ureas or carbamates of heterocyclic thioesters . 2. Description of Related Art Hair loss occurs in a variety of situations . These situations include male pattern alopecia, alopecia senilis, alopecia areata, diseases accompanied by basic skin lesions or tumors, and systematic disorders such as nutritional disorders and internal secretion disorders. The mechanisms causing hair loss are very complicated, but in some instances can be attributed to aging, genetic disposition, the activation of male hormones, the loss of blood supply to hair follicles, and scalp abnormalities. The immunosuppressant drugs FK506, rapamycin and cyclosporin are well known as potent T-cell specific immunosuppressants, and are effective against graft rejection after organ transplantation. It has been reported that topical, but not oral, application of FK506 (Yamamoto et al . , J. Invest. Dermatol., 1994, 102, 160-164; Jiang et al., J. Invest. Dermatol. 1995, 104, 523-525) and cyclosporin (Iwabuchi et al . , J. Dermatol. Sci. 1995, 9, 64-69) stimulates hair growth in a dose-dependent manner. One form of hair loss, alopecia areata, is known to be associated with autoimmune activities; hence, topically administered immunomodulatory compounds are expected to demonstrate efficacy for treating that type of hair loss. The hair growth stimulating effects of FK506 have been the subject of an international patent filing covering FK506 and structures related thereto for hair growth stimulation (Honbo et al . , EP 0 423 714 A2) . Honbo et al . discloses the use of relatively large tricyclic compounds, known for their immunosuppressive effects, as hair revitalizing agents. The hair growth and revitalization effects of FK506 and related agents are disclosed in many U.S. patents (Goulet et al . , U.S. Patent No. 5,258,389; Luly et al . , U.S. Patent No. 5,457,111; Goulet et al . , U.S. Patent No. 5,532,248; Goulet et al . , U.S. Patent No. 5,189,042; and Ok et al . , U.S. Patent No. 5,208,241; Rupprecht et al . , U.S. Patent No. 5,284,840; Organ et al . , U.S. Patent No. 5,284,877) . These patents claim FK506 related compounds. Although they do not claim methods of hair revitalization, they disclose the known use of FK506 for effecting hair growth. Similar to FK506 (and the claimed variations in the Honbo et al . patent), the compounds claimed in these patents are relatively large. Further, the cited patents relate to immunomodulatory compounds for use in autoimmune related diseases, for which FK506's efficacy is well known. Other U.S. patents disclose the use of cyclosporin and related compounds for hair revitalization (Hauer et al . , U.S. Patent No. 5,342,625; Eberle, U.S. Patent No. 5,284,826; Hewitt et al . , U.S. Patent No. 4,996,193) . These patents also relate to compounds useful for treating autoimmune diseases and cite the known use of cyclosporin and related immunosuppressive compounds for hair growth. However, immunosuppressive compounds by definition suppress the immune system and also exhibit other toxic side effects. Accordingly, there is a need for non-immunosuppressant , small molecule compounds which are useful as hair revitalizing compounds . Hamilton and Steiner disclose in U.S. Patent No. 5,614,547 novel pyrrolidine carboxylate compounds which bind to the immunophilin FKBP12 and stimulate nerve growth, but which lack immunosuppressive effects. Unexpectedly, it has been discovered that these non-immunosuppressant compounds promote hair growth with an efficacy similar to FK506. Yet their novel small molecule structure and non- immunosuppressive properties differentiate them from FK506 and related immunosuppressive compounds found in the prior art . SUMMARY OF THE INVENTION The present invention relates to a method for treating alopecia or promoting hair growth in an animal, which comprises administering to said animal an effective amount of an N-linked urea or carbamate of a heterocyclic thioester. The present invention further relates to a pharmaceutical composition which comprises: (i) an effective amount of an N-linked urea or carbamate of a heterocyclic thioester for treating alopecia or promoting hair growth in an animal; and (ii) a pharmaceutically acceptable carrier. The N-linked ureas or carbamates of heterocyclic thioesters used in the inventive methods and pharmaceutical compositions have an affinity for FKBP- type immunophilins, such as FKBP12, and do not exert any significant immunosuppressive activity. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a photograph of C57 Black 6 mice before being shaved for the hair regeneration experiment . FIG. 2 is a photograph of mice treated with a vehicle after six weeks. FIG. 2 shows that less than 3% of the shaved area is covered with new hair growth when the vehicle (control) is administered. FIG. 3 is a photograph of mice treated with GPI 1046, a related non- immunosuppressive neuro- immunophilin FKBP ligand, after six weeks. FIG. 3 shows the remarkable effects of non- immunosuppressive neuroimmunophilin FKBP ligands, wherein 90% of the shaved area is covered with new hair growth. FIG. 4 is a photograph of mice treated with 30 μM of GPI 1046, a related non- immunosuppressive neuroimmunophilin FKBP ligand, after six weeks. FIG. 4 shows the remarkable ability of non-immunosuppressive neuroimmunophilin FKBP ligands to achieve, essentially, complete hair regrowth in the shaved area. FIG. 5 is a bar graph depicting the relative hair growth indices for C57 Black 6 mice treated with a vehicle, FK506, and various non- immunosuppressive neuroimmunophilin FKBP ligands, including GPI 1605, 14 days after treatment with each identified compound. Figure 5 demonstrates the remarkable early hair growth promoted by a wide variety of non-immuno-suppressive neuroimmunophilin FKBP ligands. DETAILED DESCRIPTION OF THE INVENTION Definitions "Alopecia" refers to deficient hair growth and partial or complete loss of hair, including without limitation androgenic alopecia (male pattern baldness) , toxic alopecia, alopecia senilis, alopecia areata, alopecia pelada and trichotillomania . Alopecia results when the pilar cycle is disturbed. The most frequent phenomenon is a shortening of the hair growth or anagen phase due to cessation of cell proliferation. This results in an early onset of the catagen phase, and consequently a large number of hairs in the telogen phase during which the follicles are detached from the dermal papillae, and the hairs fall out. Alopecia has a number of etiologies, including genetic factors, aging, local and systemic diseases, febrile conditions, mental stresses, hormonal problems, and secondary effects of drugs. "GPI 1605" refers to a compound of formula "GPI 1046" refers to 3- (3-pyridyl) -1-propyl (2s) 1- (3 , 3 -dimethyl -l , 2 -dioxopentyl ) -2 pyrrolidinecarboxylate, a compound of formula "GPI 1312" refers to a compound of formula "GPI 1572" refers to a compound of formula "GPI 1389" refers to a compound of formula "GPI 1511" refers to a compound of formula "GPI 1234" refers to a compound of formula "Isomers" refer to different compounds that have the same molecular formula. "Stereoisomers" are isomers that differ only in the way the atoms are arranged in space. "Enantiomers" are a pair of stereoisomers that are non-superimposable mirror images of each other. "Diastereoisomers" are stereoisomers which are not mirror images of each other. "Racemic mixture" means a mixture containing equal parts of individual enantiomers. "Non-racemic mixture" is a mixture containing unequal parts of individual enantiomers or stereoisomers. "Pharmaceutically acceptable salt, ester, or solvate" refers to a salt, ester, or solvate of a subject compound which possess the desired pharmacological activity and which is neither biologically nor otherwise undesirable. A salt, ester, or solvate can be formed with inorganic acids such as acetate, adipate, alginate, aspartate, benzoate, benzenesulfonate, bisulfate, butyrate, citrate, camphorate, c amphor sul f ona t e , cyclopentanepropionate, digluconate, dodecylsulfate, ethanesulfonate, fumarate, glucoheptanoate, gluconate, glycerophosphate, hemisulfate, heptanoate, hexanoate, hydrochloride, hydrobromide, hydroiodide, 2- hydroxye thanesul fonate , lactate, maleate, methanesulfonate, naphthylate, 2-naphthalenesulfonate, nicotinate, oxaltate, sulfate, thiocyanate, tosylate and undecanoate. Examples of base salts, esters, or solvates include ammonium salts; alkali metal salts, such as sodium and potassium salts; alkaline earth metal salts, such as calcium and magnesium salts; salts with organic bases, such as dicyclohexylamine salts; N-methyl-D-glucamine; and salts with amino acids, such as arginine, lysine, and so forth. Also, the basic nitrogen-containing groups can be quarternized with such agents as lower alkyl halides, such as methyl, ethyl, propyl, and butyl chlorides, bromides, and iodides; dialkyl sulfates, such as dimethyl, diethyl, dibutyl, and diamyl sulfates; long chain halides, such as decyl, lauryl, myristyl, and stearyl chlorides, bromides, and iodides; aralkyl halides, such as benzyl and phenethyl bromides; and others. Water or oil-soluble or dispersible products are thereby obtained. "Pilar cycle" refers to the life cycle of hair follicles, and includes three phases: (1) the anagen phase, the period of active hair growth which, insofar as scalp hair is concerned, lasts about three to five years; (2) the catagen phase, the period when growth stops and the follicle atrophies which, insofar as scalp hair is concerned, lasts about one to two weeks; and (3) the telogen phase, the rest period when hair progressively separates and finally falls out which, insofar as scalp hair is concerned, lasts about three to four months. Normally 80 to 90 percent of the follicles are in the anagen phase, less than 1 percent being in the catagen phase, and the rest being in the telogen phase. In the telogen phase, hair is uniform in diameter with a slightly bulbous, non-pigmented root. By contrast, in the anagen phase, hair has a large colored bulb at its root. "Promoting hair growth" refers to maintaining, inducing, stimulating, accelerating, or revitalizing the germination of hair. "Treating alopecia" refers to: (i) preventing alopecia in an animal which may be predisposed to alopecia; and/or (ii) inhibiting, retarding or reducing alopecia; and/or (iii) promoting hair growth; and/or (iv) prolonging the anagen phase of the hair cycle; and/or (v) converting vellus hair to growth as terminal hair. Terminal hair is coarse, pigmented, long hair in which the bulb of the hair follicle is seated deep in the dermis. Vellus hair, on the other hand, is fine, thin, non-pigmented short hair in which the hair bulb is located superficially in the dermis. As alopecia progresses, the hairs change from the terminal to the vellus type. Methods of the Present Invention The present invention relates to a method for treating alopecia or promoting hair growth in an animal, which comprises administering to said animal an effective amount of an N-linked urea or carbamate of a heterocyclic thioester. The inventive method is particularly useful for treating male pattern alopecia, alopecia senilis, alopecia areata, alopecia resulting from skin lesions or tumors, alopecia resulting from cancer therapy such as chemotherapy and radiation, and alopecia resulting from systematic disorders such as nutritional disorders and internal secretion disorders. Pharmaceutical Compositions of the Present Invention The present invention also relates to a pharmaceutical composition comprising: (i) an effective amount of an N-linked urea or carbamate of a heterocyclic thioester for treating alopecia or promoting hair growth in an animal ; and (ii) a pharmaceutically acceptable carrier. N-LINKED UREAS AND CARBAMATES OF HETEROCYCLIC THIOESTERS The N-linked ureas and carbamates of heterocyclic thioesters used in the methods and pharmaceutical compositions of the present invention are low molecular weight, small molecule compounds having an affinity for an FKBP-type immunophilin, such as FKBP12. When an N-linked urea or carbamate of a heterocyclic thioester binds to an FKBP-type immunophilin, it has been found to inhibit the prolyl- peptidyl cis- trans isomerase, or rotamase, activity of the binding protein. Unexpectedly, these compounds have also been found to stimulate hair growth. These compounds are devoid of any significant immunosuppressive activity. FORMULA I The N-linked urea or carbamate of a heterocyclic thioester may be a compound of formula I or a pharmaceutically acceptable salt, ester, or solvate thereof, wherein: A and B, taken together with the nitrogen and carbon atoms to which they are respectively attached, form a 5-7 membered saturated or unsaturated heterocyclic ring containing, in addition to the nitrogen atom, one or more additional O, S, SO, S0 2 , N, NH, or NR 3 heteroatom (s) ; X is either O or S; Y is a direct bond, straight or branched chain alkyl, or C 2 -C 6 straight or branched chain alkenyl, wherein any carbon atom of said alkyl or alkenyl is optionally substituted in one or more position(s) with amino, halo, haloalkyl, thiocarbonyl , ester, thioester, alkoxy, alkenoxy, cyano, nitro, imino, alkylamino, aminoalkyl, sulfhydryl, thioalkyl, sulfonyl, or oxygen to form a carbonyl, or wherein any carbon atom of said alkyl or alkenyl is optionally replaced with 0, NH, NR 3 , S, SO, or S0 2 ; R 3 is selected from the group consisting of hydrogen, straight or branched chain alkyl, C 3 -C 6 straight or branched chain alkenyl or alkynyl, and C x - C 4 bridging alkyl wherein a bridge is formed between the nitrogen and a carbon atom of said alkyl or alkenyl chain containing said heteroatom to form a ring, wherein said ring is optionally fused to an Ar group ; Ar is an alicyclic or aromatic, mono-, bi- or tricyclic, carbo- or heterocyclic ring, wherein the ring is either unsubstituted or substituted with one or more substituent (s) independently selected from the group including, but not limited to, alkylamino, amido, amino, aminoalkyl, azo, benzyloxy, C 1 -C 9 straight or branched chain alkyl, C 1 -C 9 alkoxy, C 2 -C 9 alkenyloxy, C 2 -C 9 straight or branched chain alkenyl, C 3 -C 8 cycloalkyl, C 5 -C 7 cycloalkenyl , carbonyl, carboxy, cyano, diazo, ester, formanilido, halo, haloalkyl , hydroxy, imino, isocyano, isonitrilo, nitrilo, nitro, nitroso, phenoxy, sulfhydryl, sulfonylsulfoxy, thio, thioalkyl, thiocarbonyl , thiocyano, thioester, thioformamido, trifluoromethyl , and carboxylic and heterocyclic moieties, including alicyclic and aromatic structures; wherein the individual ring size is 5-8 members; wherein said heterocyclic ring contains 1-6 heteroatom (s) independently selected from the group consisting of O, N, and S; and wherein said aromatic or tertiary alkyl amine is optionally oxidized to a corresponding N-oxide; Z is a direct bond, straight or branched chain alkyl, or C 2 -C 6 straight or branched chain alkenyl, wherein any carbon atom of said alkyl or alkenyl is optionally substituted in one or more position(s) with amino, halo, haloalkyl, thiocarbonyl , ester, thioester, alkoxy, alkenoxy, cyano, nitro, imino, alkylamino, aminoalkyl, sulfhydryl, thioalkyl, sulfonyl, or oxygen to form a carbonyl, or wherein any carbon atom of said alkyl or alkenyl is optionally replaced with O, NH, NR 3 , S, SO, or S0 2 ; C and D are independently hydrogen, Ar, straight or branched chain alkyl, or C 2 -C 6 straight or branched chain alkenyl; wherein said alkyl or alkenyl is optionally substituted with one or more substituent (s) independently selected from the group consisting of C 3 -C 8 cycloalkyl, C 5 -C 7 cycloalkenyl , hydroxy, carbonyl oxygen, and Ar; wherein said alkyl, alkenyl, cycloalkyl or cycloalkenyl is optionally substituted with alkyl, C 2 -C 6 alkenyl, hydroxy, amino, halo, haloalkyl, thiocarbonyl, ester, thioester, alkoxy, alkenoxy, cyano, nitro, imino, alkylamino, aminoalkyl, sulfhydryl, thioalkyl, or sulfonyl; wherein any carbon atom of said alkyl or alkenyl is optionally substituted in one or more position (s) with oxygen to form a carbonyl; or wherein any carbon atom of said alkyl or alkenyl is optionally replaced with 0, NH, NR 3 , S, SO, or S0 2 ; W is 0 or S; and U is either O or N, provided that: when U is O, then R x is a lone pair of electrons and R 2 is selected from the group consisting of Ar, C 3 -C 8 cycloalkyl, C^C g straight or branched chain alkyl, and C 2 -C 6 straight or branched chain alkenyl, wherein said alkyl or alkenyl is optionally substituted with one or more substituent (s) independently selected from the group consisting of Ar and C 3 -C 8 cycloalkyl; and when U is N, then R x and R 2 are independently selected from the group consisting of hydrogen, Ar, C 3 -C 8 cycloalkyl, C^Cg straight or branched chain alkyl, and C 2 -C 6 straight or branched chain alkenyl, wherein said alkyl or alkenyl is substituted with one or more substituent (s) independently selected from the group consisting of Ar and C 3 -C 8 cycloalkyl; or R λ and R 2 are taken together to form a heterocyclic 5 or 6 membered ring selected from the group consisting of pyrrolidine, imidazolidine, pyrazolidine, piperidine, and piperazine. Useful carbo- and heterocyclic rings include without limitation phenyl, benzyl, naphthyl, indenyl, azulenyl, fluorenyl, anthracenyl , indolyl , isoindolyl, indolinyl, benzofuranyl , benzothiophenyl, indazolyl, benzimidazolyl, benzthiazolyl , tetrahydrofuranyl , tetrahydropyranyl, pyridyl, pyrrolyl, pyrrolidinyl, pyridinyl, pyrimidinyl , purinyl , quinolinyl, isoquinolinyl, tetrahydroquinolinyl , quinolizinyl , furyl , thiophenyl , imidazolyl , oxazolyl , benzoxazolyl , thiazolyl, isoxazolyl, isotriazolyl , oxadiazolyl, triazolyl, thiadiazolyl , pyridazinyl, pyrimidinyl, pyrazinyl, triazinyl, trithianyl, indolizinyl, pyrazolyl, pyrazolinyl, pyrazolidinyl , thienyl, tetrahydroisoquinolinyl, cinnolinyl, phthalazinyl , quinazolinyl , quinoxalinyl , naphthyridinyl , pteridinyl, carbazolyl, acridinyl , phenazinyl, phenothiazinyl, and phenoxazinyl . In a preferred embodiment of formula I, Ar is selected from the group consisting of phenyl, benzyl, naphthyl, indolyl , pyridyl, pyrrolyl, pyrrolidinyl, pyridinyl, pyrimidinyl, purinyl, quinolinyl, isoquinolinyl, furyl , fluorenyl, thiophenyl, imidazolyl, oxazolyl, thiazolyl, pyrazolyl, and thienyl . In a more preferred embodiment of the compounds of formula I, the N-linked urea or carbamate of a heterocyclic thioester is the compound GPI 1605, of the formula FORMULA II The N-linked urea or carbamate of a heterocyclic thioester may also be a compound of formula II or a pharmaceutically acceptable salt, ester, or solvate thereof, wherein: E, F, G and J are independently CH 2 , O, S, SO, S0 2 , NH, or NR 3 ; X is either 0 or S; Y is a direct bond, straight or branched chain alkyl, or C 2 -C 6 straight or branched chain alkenyl, wherein any carbon atom of said alkyl or alkenyl is optionally substituted in one or more position(s) with amino, halo, haloalkyl, thiocarbonyl, ester, thioester, alkoxy, alkenoxy, cyano, nitro, imino, alkylamino, aminoalkyl, sulfhydryl, thioalkyl, sulfonyl, or oxygen to form a carbonyl, or wherein any carbon atom of said alkyl or alkenyl is optionally replaced with 0, NH, NR 3 , S, SO, or S0 2 ; R 3 is selected from the group consisting of hydrogen, C 1 -C 4 straight or branched chain alkyl, C 3 -C 4 straight or branched chain alkenyl or alkynyl, and C λ - C 4 bridging alkyl wherein a bridge is formed between the nitrogen and a carbon atom of said alkyl or alkenyl chain containing said heteroatom to form a ring, wherein said ring is optionally fused to an Ar group ; Ar is an alicyclic or aromatic, mono-, bi- or tricyclic, carbo- or heterocyclic ring, wherein the ring is either unsubstituted or substituted with one or more substituent (s) independently selected from the group including, but not limited to, alkylamino, amido, amino, aminoalkyl, azo, benzyloxy, C_-C 9 straight or branched chain alkyl, C ! -C 9 alkoxy, C 2 -C 9 alkenyloxy, C 2 -C 9 straight or branched chain alkenyl, C 3 -C 8 cycloalkyl, C 5 -C 7 cycloalkenyl , carbonyl, carboxy, cyano, diazo, ester, formanilido, halo, haloalkyl, hydroxy, imino, isocyano, isonitrilo, nitrilo, nitro, nitroso, phenoxy, sulfhydryl, sulfonylsulfoxy, thio, thioalkyl, thiocarbonyl, thiocyano, thioester, thioformamido, trifluoromethyl , and carboxylic and heterocyclic moieties, including alicyclic and aromatic structures; wherein the individual ring size is 5-8 members; wherein said heterocyclic ring contains 1-6 heteroatom (s) independently selected from the group consisting of 0, N, and S; and wherein said aromatic or tertiary alkyl amine is optionally oxidized to a corresponding N-oxide; Z is a direct bond, Ci-Cg straight or branched chain alkyl, or C 2 -C 5 straight or branched chain alkenyl, wherein any carbon atom of said alkyl or alkenyl is optionally substituted in one or more position (s) with amino, halo, haloalkyl, thiocarbonyl, ester, thioester, alkoxy, alkenoxy, cyano, nitro, imino, alkylamino, aminoalkyl, sulfhydryl, thioalkyl, sulfonyl, or oxygen to form a carbonyl, or wherein any carbon atom of said alkyl or alkenyl is optionally replaced with 0, NH, NR 3 , S, SO, or S0 2 ; C and D are independently hydrogen, Ar, C x -C 6 straight or branched chain alkyl, or C 2 -C 6 straight or branched chain alkenyl; wherein said alkyl or alkenyl is optionally substituted with one or more substituent (s) independently selected from the group consisting of C 3 -C 8 cycloalkyl, C 5 -C 7 cycloalkenyl, hydroxy, carbonyl oxygen, and Ar; wherein said alkyl, alkenyl, cycloalkyl or cycloalkenyl is optionally substituted with alkyl, C 2 -C 6 alkenyl, hydroxy, amino, halo, haloalkyl, thiocarbonyl, ester, thioester, alkoxy, alkenoxy, cyano, nitro, imino, alkylamino, aminoalkyl, sulfhydryl, thioalkyl, or sulfonyl; wherein any carbon atom of said alkyl or alkenyl is optionally substituted in one or more position (s) with oxygen to form a carbonyl; or wherein any carbon atom of said alkyl or alkenyl is optionally replaced with 0, NH, NR 3 , S, SO, or S0 2 ; W is 0 or S; and U is either 0 or N, provided that: when U is 0, then R λ is a lone pair of electrons and R 2 is selected from the group consisting of Ar, C 3 -C 8 cycloalkyl, straight or branched chain alkyl, and C 2 -C 6 straight or branched chain alkenyl, wherein said alkyl or alkenyl is optionally substituted with one or more substituent (s) independently selected from the group consisting of Ar and C 3 -C 8 cycloalkyl; and when U is N, then R x and R 2 are independently selected from the group consisting of hydrogen, Ar, C 3 -C 8 cycloalkyl, C- L -Cg straight or branched chain alkyl, and C 2 -C 6 straight or branched chain alkenyl, wherein said alkyl or alkenyl is optionally substituted with one or more substituent (s) independently selected from the group consisting of Ar and C 3 -C 8 cycloalkyl; or R λ and R 2 are taken together to form a heterocyclic 5 or 6 membered ring selected from the group consisting of pyrrolidine, imidazolidine, pyrazolidine, piperidine, and piperazine. Useful carbo- and heterocyclic rings include without limitation phenyl, benzyl, naphthyl, indenyl, azulenyl, fluorenyl, anthracenyl, indolyl , isoindolyl, indolinyl, benzofuranyl , benzothiophenyl, indazolyl, benzimidazolyl, benzthiazolyl , tetrahydrofuranyl , tetrahydropyranyl, pyridyl, pyrrolyl, pyrrolidinyl, pyridinyl, pyrimidinyl, purinyl, quinolinyl, isoquinolinyl, tetrahydroquinolinyl , quinolizinyl , furyl , thiophenyl , imidazolyl , oxazolyl , benzoxazolyl , thiazolyl, isoxazolyl, isotriazolyl , oxadiazolyl , triazolyl, thiadiazolyl , pyridazinyl, pyrimidinyl, pyrazinyl, triazinyl, trithianyl, indolizinyl, pyrazolyl, pyrazolinyl, pyrazolidinyl , thienyl, tetrahydroisoquinolinyl, cinnolinyl, phthalazinyl , quinazolinyl , quinoxalinyl , naphthyridinyl , pteridinyl, carbazolyl, acridinyl , phenazinyl, phenothiazinyl, and phenoxazinyl . In a preferred embodiment of formula II, Ar is selected from the group consisting of phenyl, benzyl, naphthyl, pyrrolyl, pyrrolidinyl, pyridinyl, pyrimidinyl, purinyl, quinolinyl, isoquinolinyl, furyl, thiophenyl, imidazolyl, oxazolyl, thiazolyl, pyrazolyl, and thienyl. FORMULA III Additionally, the N-linked urea or carbamate of a heterocyclic thioester may be a compound of formula III or a pharmaceutically acceptable salt, ester, or solvate thereof, wherein: E, F, and G are independently CH 2 , 0, S, SO, S0 2 , NH, and NR 3 ; X is either 0 or S; Y is a direct bond, straight or branched chain alkyl, or C 2 -C 6 straight or branched chain alkenyl, wherein any carbon atom of said alkyl or alkenyl is optionally substituted in one or more position(s) with amino, halo, haloalkyl, thiocarbonyl, ester, thioester, alkoxy, alkenoxy, cyano, nitro, imino, alkylamino, aminoalkyl, sulfhydryl, thioalkyl, sulfonyl, or oxygen to form a carbonyl, or wherein any carbon atom of said alkyl or alkenyl is optionally replaced with O, NH, NR 3 , S, SO, or S0 2 ; R 3 is selected from the group consisting of hydrogen, C. L -C 4 straight or branched chain alkyl, C 3 -C 4 straight or branched chain alkenyl or alkynyl , and C λ - C 4 bridging alkyl wherein a bridge is formed between the nitrogen and a carbon atom of said alkyl or alkenyl chain containing said heteroatom to form a ring, wherein said ring is optionally fused to an Ar group ; Ar is an alicyclic or aromatic, mono-, bi- or tricyclic, carbo- or heterocyclic ring, wherein the ring is either unsubstituted or substituted with one or more substituent (s) independently selected from the group including, but not limited to, alkylamino, amido, amino, aminoalkyl, azo, benzyloxy, straight or branched chain alkyl, C^C g alkoxy, C 2 -C 9 alkenyloxy, C 2 -C 9 straight or branched chain alkenyl, C 3 _C 8 cycloalkyl, C 5 -C 7 cycloalkenyl , carbonyl, carboxy, cyano, diazo, ester, formanilido, halo, haloalkyl, hydroxy, imino, isocyano, isonitrilo, nitrilo, nitro, nitroso, phenoxy, sulfhydryl, sulfonylsulfoxy, thio, thioalkyl, thiocarbonyl, thiocyano, thioester, thioformamido, trifluoromethyl , and carboxylic and heterocyclic moieties, including alicyclic and aromatic structures; wherein the individual ring size is 5-8 members; wherein said heterocyclic ring contains 1-6 heteroatom (s) independently selected from the group consisting of O, N, and S; and wherein said aromatic or tertiary alkyl amine is optionally oxidized to a corresponding N-oxide; Z is a direct bond, C x -C 6 straight or branched chain alkyl, or C 2 -C 6 straight or branched chain alkenyl, wherein any carbon atom of said alkyl or alkenyl is optionally substituted in one or more position(s) with amino, halo, haloalkyl, thiocarbonyl, ester, thioester, alkoxy, alkenoxy, cyano, nitro, imino, alkylamino, aminoalkyl, sulfhydryl, thioalkyl, sulfonyl, or oxygen to form a carbonyl, or wherein any carbon atom of said alkyl or alkenyl is optionally replaced with 0, NH, NR 3 , S, SO, or S0 2 ; C and D are independently hydrogen, Ar, C^C g straight or branched chain alkyl, or C 2 -C 6 straight or branched chain alkenyl ; wherein said alkyl or alkenyl is optionally substituted with one or more substituent (s) independently selected from the group consisting of C 3 -C 8 cycloalkyl, C 5 -C 7 cycloalkenyl, hydroxy, carbonyl oxygen, and Ar; wherein said alkyl, alkenyl, cycloalkyl or cycloalkenyl is optionally substituted with C 1 -C 6 alkyl, C 2 -C 6 alkenyl, hydroxy, amino, halo, haloalkyl, thiocarbonyl, ester, thioester, alkoxy, alkenoxy, cyano, nitro, imino, alkylamino, aminoalkyl, sulfhydryl, thioalkyl, or sulfonyl; wherein any carbon atom of said alkyl or alkenyl is optionally substituted in one or more position (s) with oxygen to form a carbonyl; or wherein any carbon atom of said alkyl or alkenyl is optionally replaced with 0, NH, NR 3 , S, SO, or S0 2 ; W is 0 or S; and U is either 0 or N, provided that: when U is 0, then R 1 is a lone pair of electrons and R 2 is selected from the group consisting of Ar, C 3 -C 8 cycloalkyl, C j -Cg straight or branched chain alkyl, and C 2 -C 6 straight or branched chain alkenyl, wherein said alkyl or alkenyl is optionally substituted with one or more substituent (s) independently selected from the group consisting of Ar and C 3 -C 8 cycloalkyl; and when U is N, then R x and R 2 are independently selected from the group consisting of hydrogen, Ar, C 3 -C 8 cycloalkyl, Ci-Cg straight or branched chain alkyl, and C 2 -C 6 straight or branched chain alkenyl, wherein said alkyl or alkenyl is optionally substituted with one or more substituent (s) independently selected from the group consisting of Ar and C 3 -C 8 cycloalkyl; or R λ and R 2 are taken together to form a heterocyclic 5 or 6 membered ring selected from the group consisting of pyrrolidine, imidazolidine, pyrazolidine, piperidine, and piperazine . Useful carbo- and heterocyclic rings include without limitation phenyl, benzyl, naphthyl, indenyl, azulenyl, fluorenyl, anthracenyl, indolyl , isoindolyl, indolinyl, benzofuranyl , benzothiophenyl, indazolyl, benzimidazolyl, benzthiazolyl , tetrahydrofuranyl , tetrahydropyranyl, pyridyl, pyrrolyl, pyrrolidinyl, pyridinyl, pyrimidinyl, purinyl, quinolinyl, isoquinolinyl, tetrahydroquinolinyl , quinolizinyl , furyl, thiophenyl, imidazolyl, oxazolyl, benzoxazolyl, thiazolyl, isoxazolyl, isotriazolyl , oxadiazolyl, triazolyl, thiadiazolyl , pyridazinyl, pyrimidinyl, pyrazinyl, triazinyl, trithianyl, indolizinyl, pyrazolyl, pyrazolinyl, pyrazolidinyl , thienyl, tetrahydroisoquinolinyl, cinnolinyl, phthalazinyl , quinazolinyl , quinoxalinyl , naphthyridinyl , pteridinyl, carbazolyl, acridinyl, phenazinyl, phenothiazinyl, and phenoxazinyl . In a preferred embodiment of formula III, Ar is selected from the group consisting of phenyl, benzyl, naphthyl, pyrrolyl, pyrrolidinyl, pyridinyl, pyrimidinyl, purinyl, quinolinyl, isoquinolinyl, furyl, thiophenyl, imidazolyl, oxazolyl, thiazolyl, pyrazolyl , and thienyl . In a more preferred embodiment of the compounds of formula III, the N-linked urea or carbamate of a heterocyclic thioester is the compound GPI 1605, of the formula FORMULA IV The N-linked urea or carbamate of a heterocyclic thioester may further be a compound of formula IV or a pharmaceutically acceptable salt, ester, or solvate thereof, wherein: n is 1, 2 or 3; X is either 0 or S; Y is a direct bond, C^Cg straight or branched chain alkyl, or C 2 -C 6 straight or branched chain alkenyl, wherein any carbon atom of said alkyl or alkenyl is optionally substituted in one or more position(s) with amino, halo, haloalkyl, thiocarbonyl, ester, thioester, alkoxy, alkenoxy, cyano, nitro, imino, alkylamino, aminoalkyl, sulfhydryl, thioalkyl, sulfonyl, or oxygen to form a carbonyl, or wherein any carbon atom of said alkyl or alkenyl is optionally replaced with 0, NH, NR 3 , S, SO, or S0 2 ; R 3 is selected from the group consisting of hydrogen, C^C^ straight or branched chain alkyl, C 3 -C 4 straight or branched chain alkenyl or alkynyl, and C x - C 4 bridging alkyl wherein a bridge is formed between the nitrogen and a carbon atom of said alkyl or alkenyl chain containing said heteroatom to form a ring, wherein said ring is optionally fused to an Ar group ; Ar is an alicyclic or aromatic, mono-, bi- or tricyclic, carbo- or heterocyclic ring, wherein the ring is either unsubstituted or substituted with one or more substituent (s) independently selected from the group including, but not limited to, alkylamino, amido, amino, aminoalkyl, azo, benzyloxy, C- L -C,, straight or branched chain alkyl, C 1 -C 9 alkoxy, C 2 -C 9 alkenyloxy, C 2 -C 9 straight or branched chain alkenyl, C 3 -C 8 cycloalkyl, C 5 -C 7 cycloalkenyl, carbonyl, carboxy, cyano, diazo, ester, formanilido, halo, haloalkyl, hydroxy, imino, isocyano, isonitrilo, nitrilo, nitro, nitroso, phenoxy, sulfhydryl, sulfonylsulfoxy, thio, thioalkyl, thiocarbonyl, thiocyano, thioester, thioformamido, trifluoromethyl, and carboxylic and heterocyclic moieties, including alicyclic and aromatic structures; wherein the individual ring size is 5-8 members; wherein said heterocyclic ring contains 1-6 heteroatom(s) independently selected from the group consisting of O, N, and S; and wherein said aromatic or tertiary alkyl amine is optionally oxidized to a corresponding N-oxide; Z is a direct bond, Cj-Cg straight or branched chain alkyl, or C 2 -C 6 straight or branched chain alkenyl, wherein any carbon atom of said alkyl or alkenyl is optionally substituted in one or more position(s) with amino, halo, haloalkyl, thiocarbonyl, ester, thioester, alkoxy, alkenoxy, cyano, nitro, imino, alkylamino, aminoalkyl, sulfhydryl, thioalkyl, sulfonyl, or oxygen to form a carbonyl, or wherein any carbon atom of said alkyl or alkenyl is optionally replaced with 0, NH, NR 3 , S, SO, or S0 2 ; C and D are independently hydrogen, Ar, C^C g straight or branched chain alkyl, or C 2 -C 6 straight or branched chain alkenyl ; wherein said alkyl or alkenyl is optionally substituted with one or more substituent (s) independently selected from the group consisting of C 3 -C 8 cycloalkyl, C 5 -C 7 cycloalkenyl, hydroxy, carbonyl oxygen, and Ar; wherein said alkyl, alkenyl, cycloalkyl or cycloalkenyl is optionally substituted with C 1 -C 6 alkyl, C 2 -C 6 alkenyl, hydroxy, amino, halo, haloalkyl, thiocarbonyl, ester, thioester, alkoxy, alkenoxy, cyano, nitro, imino, alkylamino, aminoalkyl, sulfhydryl, thioalkyl, or sulfonyl; wherein any carbon atom of said alkyl or alkenyl is optionally substituted in one or more position (s) with oxygen to form a carbonyl; or wherein any carbon atom of said alkyl or alkenyl is optionally replaced with 0, NH, NR 3 , S, SO, or S0 2 ; W is 0 or S; and U is either 0 or N, provided that: when U is 0, then R is a lone pair of electrons and R 2 is selected from the group consisting of Ar, C 3 -C 8 cycloalkyl, straight or branched chain alkyl, and C 2 -C 6 straight or branched chain or alkenyl , wherein said alkyl or alkenyl is optionally substituted with one or more substituent (s) independently selected from the group consisting of Ar and C 3 -C 8 cycloalkyl; and when U is N, then R and R 2 are independently selected from the group consisting of hydrogen, Ar, C 3 -C 8 cycloalkyl, Cj-Cg straight or branched chain alkyl, and C 2 -C 6 straight or branched chain alkenyl, wherein said alkyl or alkenyl is optionally substituted with one or more substituent (s) independently selected from the group consisting of Ar and C 3 -C 8 cycloalkyl; or R x and R 2 are taken together to form a heterocyclic 5 or 6 membered ring selected from the group consisting of pyrrolidine, imidazolidine, pyrazolidine, piperidine, and piperazine. Useful carbo- and heterocyclic rings include without limitation phenyl, benzyl, naphthyl, indenyl, azulenyl, fluorenyl, anthracenyl, indolyl , isoindolyl, indolinyl, benzofuranyl , benzothiophenyl, indazolyl, benzimidazolyl, benzthiazolyl, tetrahydrofuranyl , tetrahydropyranyl, pyridyl, pyrrolyl, pyrrolidinyl, pyridinyl, pyrimidinyl, purinyl, quinolinyl, isoquinolinyl, tetrahydroquinolinyl , quinolizinyl , furyl , thiophenyl , imidazolyl , oxazolyl , benzoxazolyl , thiazolyl, isoxazolyl, isotriazolyl , oxadiazolyl, triazolyl, thiadiazolyl , pyridazinyl, pyrimidinyl, pyrazinyl, triazinyl, trithianyl, indolizinyl, pyrazolyl, pyrazolinyl, pyrazolidinyl , thienyl, tetrahydroisoquinolinyl, cinnolinyl, phthalazinyl , quinazolinyl , quinoxalinyl , naphthyridinyl , pteridinyl, carbazolyl, acridinyl , phenazinyl, phenothiazinyl, and phenoxazinyl . In a preferred embodiment of formula IV, Ar is selected from the group consisting of phenyl, benzyl, naphthyl, pyrrolyl, pyrrolidinyl, pyridinyl, pyrimidinyl, purinyl, quinolinyl, isoquinolinyl, furyl, thiophenyl, imidazolyl, oxazolyl, thiazolyl, pyrazolyl , and thienyl . Exemplary compounds of formula IV are presented in TABLE I. TABLE I No. n w Y Z C D R, R 2 1 1 O (CH 2 ) 2 CH 3-Pyridyl H H 2-Methylbutyl 2 1 O (CH 2 ) 2 CH 3-Pyridyl H H 1 , 1-dimethylpropyl 3 1 O (CH 2 ) 2 CH 4-Methoxy H H 1 , 1-dimethylpropyl phenyl 4 1 O CH 2 CH Phenyl H H 1 , 1-dimethylpropyl 5 1 s (CH 2 ) 2 CH 4-Methoxy H H Cyclohexyl phenyl 6 1 O (CH 2 ) 2 CH 3-Pyridyl H H Cyclohexyl 7 1 s (CH 2 ) 2 CH 3-Pyridyl H H Cyclohexyl 8 1 s (CH 2 ) 2 CH 3-Pyridyl H H 1-Adamantyl 9 1 s (CH 2 ) 2 CH 3-Pyridyl H H 1 , 1-dimethylpropyl TABLE I (continued) o. n W Y Z C D R s R 2 10 1 O (CH 2 ) 2 CH Phenyl Phenyl H 1, 1-dimethylpropyl 11 2 O (CH 2 ) 2 CH Phenyl H H 1, 1-dimethylpropyl 12 2 O (CH 2 ) 2 CH Phenyl H H Phenyl 13 2 O Direct CH 2-Phenyl 2-Phenyl H Phenyl bond ethyl ethyl 14 2 O Direct CH 2-Phenyl 2-Phenyl H Cyclohexyl bond ethyl ethyl 15 2 S Direct CH 2-Phenyl 2-Phenyl H Cyclohexyl bond ethyl ethyl 16 2 O (CH 2 ) 2 CH 4-Methoxy H H Cyclohexyl phenyl The most preferred compounds of formula IV are selected from the group consisting of: 3- (3-Pyridyl) - 1 -propyl-2S- 1- [ (2 -methylbutyl ) carbamoyl] pyrrolidine-2 -carboxylate ; 3- (3-Pyridyl) -1-propyl -2S-1- [ (1' , 1 ' - Dimethylpropyl) carbamoyl] pyrrolidine-2-carboxylate; 3- (3-Pyridyl) - 1 -propyl - 2 S - 1 - [ (cyclohexyl) thiocarbamoyl] pyrrolidine-2-carboxylate; and pharmaceutically acceptable salts, esters, and solvates thereof . FORMULA V The N-linked urea or carbamate of a heterocyclic thioester may be a compound of formula V or a pharmaceutically acceptable salt, ester, or solvate thereof, wherein: V is C, N, or S; Y is a direct bond, straight or branched chain alkyl, or C 2 -C 6 straight or branched chain alkenyl , wherein any carbon atom of said alkyl or alkenyl is optionally substituted in one or more position(s) with amino, halo, haloalkyl, thiocarbonyl, ester, thioester, alkoxy, alkenoxy, cyano, nitro, imino, alkylamino, aminoalkyl, sulfhydryl, thioalkyl, sulfonyl, or oxygen to form a carbonyl, or wherein any carbon atom of said alkyl or alkenyl is optionally replaced with 0, NH, NR 3 , S, SO, or S0 2 ; R 3 is selected from the group consisting of hydrogen, straight or branched chain alkyl, C 3 -C 6 straight or branched chain alkenyl or alkynyl, and C^ C 4 bridging alkyl wherein a bridge is formed between the nitrogen and a carbon atom of said alkyl or alkenyl chain containing said heteroatom to form a ring, wherein said ring is optionally fused to an Ar group ; Ar is an alicyclic or aromatic, mono-, bi- or tricyclic, carbo- or heterocyclic ring, wherein the ring is either unsubstituted or substituted with one or more substituent (s) ; wherein the individual ring size is 5-8 members; wherein said heterocyclic ring contains 1-6 heteroatom (s) independently selected from the group consisting of 0, N, and S; and wherein said aromatic or tertiary alkyl amine is optionally oxidized to a corresponding N-oxide; Z is a direct bond, straight or branched chain alkyl, or C 2 -C 6 straight or branched chain alkenyl, wherein any carbon atom of said alkyl or alkenyl is optionally substituted in one or more position(s) with amino, halo, haloalkyl, thiocarbonyl, ester, thioester, alkoxy, alkenoxy, cyano, nitro, imino, alkylamino, aminoalkyl, sulfhydryl, thioalkyl, sulfonyl, or oxygen to form a carbonyl, or wherein any carbon atom of said alkyl or alkenyl is optionally replaced with O, NH, NR 3 , S, SO, or S0 2 ; C and D are independently hydrogen, Ar, straight or branched chain alkyl, or C 2 -C 6 straight or branched chain alkenyl; wherein said alkyl or alkenyl is optionally substituted with one or more substituent (s) independently selected from the group consisting of C 3 -C 8 cycloalkyl, C 5 -C 7 cycloalkenyl, hydroxy, carbonyl oxygen, and Ar; wherein said alkyl, alkenyl, cycloalkyl or cycloalkenyl is optionally substituted with alkyl, C 2 -C 6 alkenyl, hydroxy, amino, halo, haloalkyl, thiocarbonyl, ester, thioester, alkoxy, alkenoxy, cyano, nitro, imino, alkylamino, aminoalkyl, sulfhydryl, thioalkyl, or sulfonyl; wherein any carbon atom of said alkyl or alkenyl is optionally substituted in one or more position (s) with oxygen to form a carbonyl; or wherein any carbon atom of said alkyl or alkenyl is optionally replaced with 0, NH, NR 3 , S, SO, or S0 2 ; and A, B, Rl, R2 , U, W, and X are as otherwise defined in formula I above. All the compounds of Formulas I-V possess asymmetric centers and thus can be produced as mixtures of stereoisomers or as individual R- and S- stereoisomers . The individual stereoisomers may be obtained by using an optically active starting material, by resolving a racemic or non-racemic mixture of an intermediate at some appropriate stage of the synthesis, or by resolving the compounds of Formulas I-V. It is understood that the compounds of Formulas I-V encompass individual stereoisomers as well as mixtures (racemic and non-racemic) of stereoisomers. Preferably, S-stereoisomers are used in the pharmaceutical compositions and methods of the present invention. Synthesis of N-linked Ureas and Carbamates of Heterocyclic Thioesters The compounds of formulas I to V may be readily prepared by standard techniques of organic chemistry, utilizing the general synthetic pathway depicted below. As described by Scheme I, cyclic amino acids 1 protected by suitable blocking groups P on the amino acid nitrogen may be reacted with thiols RSH to generate thioesters 2. After removal of the protecting group, the free amine 3 may be reacted with a variety of isocyanates or isothiocyanates to provide the final ureas or thioureas, respectively. SCHEME I R-SH Deprotect Coupling Method 3 5 Isocyanates (R'NCO) or isothiocyanates (R'NCS) 4 may be conveniently prepared from the corresponding readily available amines by reaction with phosgene or thiophosgene, as depicted in Scheme II. SCHEME II Thiols R-SH may be conveniently prepared from the corresponding readily available alcohols or halides via a two step replacement of halide by sulfur, as described in Scheme III. Halides may be reacted with thiourea, and the corresponding alkyl thiouronium salts hydrolyzed to provide thiols RSH. If alcohols are used as the starting materials, they may be first converted to the corresponding halides by standard methods . SCHEME III R-OH R-Br >- R-SH Affinity for FKBP12 The compounds used in the inventive methods and pharmaceutical compositions have an affinity for the FK506 binding protein, particularly FKBP12. The inhibition of the prolyl peptidyl cis- trans isomerase activity of FKBP may be measured as an indicator of this affinity. K L Test Procedure Inhibition of the peptidyl -prolyl isomerase (rotamase) activity of the compounds used in the inventive methods and pharmaceutical compositions can be evaluated by known methods described in the literature (Harding et al . , Nature, 1989, 341:758-760; Holt et al. J " . Am . Chem . Soc , 115:9923-9938). These values are obtained as apparent KJs and are presented for representative compounds in TABLE II. The cis- trans isomerization of an alanine-proline bond in a model substrate, N-succinyl-Ala-Ala-Pro-Phe- p-nitroanilide, is monitored spectrophotometrically in a chymotrypsin-coupled assay, which releases para- nitroanilide from the trans form of the substrate. The inhibition of this reaction caused by the addition of different concentrations of inhibitor is determined, and the data is analyzed as a change in first-order rate constant as a function of inhibitor concentration to yield the apparent K values. In a plastic cuvette are added 950 mL of ice cold assay buffer (25 mM HEPES , pH 7.8, 100 mM NaCl) , 10 mL of FKBP (2.5 mM in 10 mM Tris-Cl pH 7.5, 100 mM NaCl , 1 mM dithiothreitol) , 25 mL of chymotrypsin (50 mg/ml in 1 mM HC1) and 10 mL of test compound at various concentrations in dimethyl sulfoxide. The reaction is initiated by the addition of 5 mL of substrate (succinyl-Ala-Phe-Pro-Phe-para-nitroanilide, 5 mg/mL in 2.35 mM LiCl in trifluoroethanol) . The absorbance at 390 nm versus time is monitored for 90 seconds using a spectrophotometer and the rate constants are determined from the absorbance versus time data files. TABLE II In Vi tro Test Results - Formulas I to V Compound K- (nM) 1 +++ 2 ++ 3 ++ 4 ++ 5 ++ 6 + 7 ++ 8 +++ 9 +++ 10 +++ 11 ++ 12 +++ 13 +++ 14 +++ 15 +++ 16 ++ Relative potencies of compounds are ranked according to the following scale: ++++ denotes K A or ED50 < 1 nM; +++ denotes Ki or ED50 of 1-50 nM; ++ denotes K ± or ED 50 of 51-200 nM; + denotes K or ED of 201-500 nM. Route of Administration To effectively treat alopecia or promote hair growth, the compounds used in the inventive methods and pharmaceutical compositions must readily affect the targeted areas. For these purposes, the compounds are preferably administered topically to the skin. For topical application to the skin, the compounds can be formulated into suitable ointments containing the compounds suspended or dissolved in, for example, mixtures with one or more of the following: mineral oil, liquid petrolatum, white petrolatum, propylene glycol, polyoxyethylene polyoxypropylene compound, emulsifying wax and water. Alternatively, the compounds can be formulated into suitable lotions or creams containing the active compound suspended or dissolved in, for example, a mixture of one or more of the following: mineral oil, sorbitan monostearate, polysorbate 60, cetyl ester wax, cetearyl alcohol, 2-octyldodecanol , benzyl alcohol and water. Other routes of administration known in the pharmaceutical art are also contemplated by this invention. Dosage Dosage levels on the order of about 0.1 mg to about 10,000 mg of the active ingredient compound are useful in the treatment of the above conditions, with preferred levels of about 0.1 mg to about 1,000 mg. The specific dose level for any particular patient will vary depending upon a variety of factors, including the activity of the specific compound employed; the age, body weight, general health, sex and diet of the patient; the time of administration; the rate of excretion; drug combination; the severity of the particular disease being treated; and the form of administration. Typically, in vi tro dosage-effect results provide useful guidance on the proper doses for patient administration. Studies in animal models are also helpful . The considerations for determining the proper dose levels are well known in the art. The compounds can be administered with other hair revitalizing agents. Specific dose levels for the other hair revitalizing agents will depend upon the factors previously stated and the effectiveness of the drug combination. EXAMPLES The following examples are illustrative of the present invention and are not intended to be limitations thereon. Unless otherwise indicated, all percentages are based upon 100% by weight of the final composition. Example 1 Synthesis of 3- (3-Pyridyl) -1-propylmercaptyl 2S-1- [ (2-methylbutyl) carbamoyl] pyrrolidine-2-carboxylate (1) 3- (3 -Pyridyl) -1-propylchloride To a solution of 3- (3-pyridyl) -1-propanol (10 g; 72.4 mmol) in chloroform (100 mL) was added dropwise a solution of thionyl chloride (12.9 g; 108.6 mmol) in chloroform (50 mL) . The resulting mixture was refluxed for 1 hour, then poured into ice-cold 50% aqueous potassium hydroxide (150 mL) . The layers were separated, and the organic phase was dried, concentrated, and purified on a silica gel column, eluting with 40% ethylacetate in hexane, to obtain 10 g (65%) of the chloride as a clear oil. X H NMR (300 MHz, CDC1 3 ) : δ 2.02-2.11 (m, 2H) ; 2.77 (m, 2H) ; 3.51 (m, 2H) ; 7.20 (m, 1H) ; 7.49 (m, 1H) ; 8.45 (m, 2H) . 3- (3-Pyridyl) -1-propylmercaptan A mixture of 3- (3-pyridyl) -1-propylchloride (3 g; 19.4 mmol) and thiourea (1.48 g; 19.4 mmol) in ethanol (10 mL) was refluxed for 24 hours. Aqueous sodium hydroxide, 15 mL of a 0.75 N solution, was added, and the mixture was refluxed for an additional 2 hours . After cooling to room temperature, the solvent was removed in vacuo . Chromatographic purification of the crude thiol on a silica gel column eluting with 50% ethyl acetate in hexane delivered 1.2 g of 3- (3- Pyridyl) -1-propylmercaptan as a clear liquid. l H NMR (300 MHz, CDC1 3 ) : δ 1.34 (m, 1H) ; 1.90 (m, 2H) ; 2.52 (m, 2H) ; 2.71 (m, 2H) ; 7.81 (m, 1H) ; 7.47 (m, 1H) ; 8.42 (m, 2H) . 3- (3-Pyridyl) -1-propylmercaptyl N- ( tert- butyloxycarbonyl ) pyrrolidine-2 -carboxylate A mixture of N- ( tert-butyloxycarbonyl) - (S) - proline (3.0 g; 13.9 mmol); 3- (3-Pyridyl) -1- propylmercaptan (3.20 g ; 20.9 mmol) , dicyclohexylcarbodiimide (4.59 g; 22.24 mmol), camphorsulfonic acid (1.08 g; 4.63 mmol), and 4- dimethylaminopyridine (0.60 g; 4.63 mmol) in dry methylene chloride (100 mL) was stirred overnight. The reaction mixture was diluted with methylene chloride (50 mL) and water (100 mL) , and the layers were separated. The organic phase was washed with water (3 x 100 mL) , dried over magnesium sulfate, and concentrated, and the crude residue was purified on a silica gel column eluting with ethyl acetate to obtain 4.60 g (95%) of the thioester as a thick oil. E NMR (300 MHz, CDC1 3 ) : δ 1.45 (s, 9H) ; 1.70-2.05 (m, 5H) ; 2.32 (m, 1H) ; 2.71 (t, 2H) ; 2.85 (m, 2H) ; 3.50 (m, 2H) ; 4 . 18 (m, 1H) ; 7 . 24 (m , 1H) ; 7 . 51 (m, 1H) ; 8 . 48 (m, 2H) . 3- (3-Pyridyl) - 1-propylmercaptyl pyrrolidine-2 - carboxylate A solution of 3- (3-Pyridyl) -1-mercaptyl N-(tert- butyloxycarbonyl) pyrrolidine-2 -carboxylate (4.60 g; 13.1 mmol) in methylene chloride (60 mL) and trifluoroacetic acid (6 mL) was stirred at room temperature for three hours. Saturated potassium carbonate was added until the pH was basic, and the reaction mixture was extracted with methylene chloride (3x) . The combined organic extracts were dried and concentrated to yield 2.36 g (75%) of the free amine as a thick oil. X H NMR (300 MHz, CDC1 3 ) : δ 1.87-2.20 (m, 6H) ; 2.79 (m, 2H) ; 3.03-3.15 (m, 4H total); 3.84 (m, 1H) ; 7.32 (m, 1H) ; 7.60 (m, 1H) ; 8.57 (m, 2H) . 3- (3-Pyridyl) -1-propylmercaptyl 2S-1- [ ( 2 - methylbutyl) carbamoyl. yrrolidine-2 -carboxylate (1) A solution of 2-methylbutylamine (113 mg; 1.3 mmol) and triethylamine (132 mg; 1.3 mmol) in methylene chloride (5 mL) was added to a solution of triphosgene (128 mg; 0.43 mmol) in methylene chloride (5 mL) . The resulting mixture was refluxed for 1 hour and then cooled to room temperature. 3- (3-Pyridyl) -1- propylmercaptyl pyrrolidine-2 -carboxylate (300 mg; 1.3 mmol) in 5 mL of methylene chloride was added and the resulting mixture was stirred for 1 hour and then partitioned between water and a 1:1 mixture of ethyl acetate and hexane. The organic phase was dried, concentrated and purified by column chromatography (50% ethyl acetate/hexane) to obtain 250 mg (55%) of the compound of Example 1 (Compound 1, Table II) as an oil. X H NMR (300 MHz, CDC1 3 ) : d λ E NMR (CDC1 3 , 300 MHz): δ 0.89-0.93 (m, 6H) ; 1.10-1.20 (m, 1H) ; 1.27 (s, 1H) ; 1.36-1.60 (m, 2H) ; 1.72 (s, 2H) ; 1.97-2.28 (m, 6H) ; 2.70-2.75 (m, 2H) ; 2.92-3.54 (m, 6H) ; 4.45- 4.47 (m, 1H) ; 7.21-7.29 (m, 1H) ; 7.53-7.56 (dd, 1H) ; 8.46-8.48 (s, 2H) . Example 2 Synthesis of 3- (3-Pyridyl) -1-propyl 2S-1- C (!' , 1' - Dimethylpropyl) carbamoyl] pyrrolidine-2 -carboxylate (2) Reaction of 3 - (3 -pyridyl ) - 1 -propylmercaptyl pyrrolidine-2 -carboxylate with the isocyanate generated from tert-amylamine and triphosgene, as described for Example 1, provided the compound of Example 2 (Compound 2, Table II) in 62% yield. H NMR (CDC1 3. 300 MHz): δ 0.83 (t, 3H) ; 1.27 (s, 6H) ; 1.64- 1.71 (m, 2H) ; 1.91-2.02 (m, 7H) ; 2.66-2.71 (t, 2H) ; 2.85 (m, 2H) ; 3.29-3.42 (m, 2H) ; 4.11 (br, 1H) ; 4.37- 4.41 (m, 1H) . Example 3 Synthesis of 3- (3 -pyridyl) -1-propylmercaptyl 2S-1- [ (cyclohexyl) thiocarbamoyl] -pyrrolidine-2 - carboxylate (7) A mixture of cyclohexylisothiocyanate (120 mg; 0.9 mmol), 3- (3 -pyridyl) -1-propylmercaptyl pyrrolidine-2 - carboxylate (200 mg; 0.9 mmol) and triethylamine (90 mg; 0.9 mmol) in 20 mL of methylene chloride was stirred for 1 hour and then partitioned between water and a 1:1 mixture of ethyl acetate and hexane. The organic phase was dried, concentrated and purified by column chromatography (50% ethyl acetate/hexane) to obtain 160 mg (47%) of the compound of Example 3 (Compound 7, Table II) . X H NMR (CDC1 3 , 300 MHz) : δ 1.16-1.40 (m, 6H) ; 1.50-1.71 (m, 4H) ; 1.95-2.08 (m, 7H) ; 2.70-2.75 (t, 2H) ; 3.03 (m, 2H) ; 3.40-3.60 (m, 2H) ; 4.95-4.98 (d, 1H) ; 5.26-5.29 (d, 1H) ; 7.17-7.25 (m, 1H) . Example 4 In Vivo Hair Generation Tests With C57 Black 6 Mice Experiment A: C57 black 6 mice were used to demonstrate the hair revitalizing properties of a low molecular weight, small molecule, non-immuno- suppressive neuroimmunophilin FKBP ligand, GPI 1046, which is related to N-linked ureas and carbamates of heterocyclic thioesters . Referring now to FIGS. 1 and 2 of the drawings, C57 black 6 mice, approximately 7 weeks old, had an area of about 2 inches by 2 inches on their hindquarters shaved to remove all existing hair. Care was taken not to nick or cause abrasion to the underlaying dermal layers. The animals were in anagen growth phase, as indicated by the pinkish color of the skin. Referring now to FIGS. 2, 3 and 4, four animals per group were treated by topical administration with 20% propylene glycol vehicle (FIG. 2), 10 μM GPI 1046 (FIG. 3) or 30 μM GPI 1046 (FIG. 4) dissolved in the vehicle. The animals were treated with vehicle or GPI 1046 every 48 hours (3 applications total over the course of 5 days) and the hair growth was allowed to proceed for 6 weeks . Hair growth was quantitated by the percent of shaved area covered by new hair growth during this time period. FIG. 2 shows that animals treated with vehicle exhibited only a small amount of hair growth in patches or tufts, with less than 3% of the shaved area covered with new growth. In contrast, FIG. 3 shows that animals treated with 10 μM GPI 1046 exhibited dramatic hair growth, covering greater than 90% of the shaved area in all animals. Further, FIG. 4 shows that mice treated with 30 μM GPI 1046 exhibited essentially complete hair regrowth and their shaved areas were indistinguishable from unshaven C57 black 6 mice . Experiment B: C57 Black 6 mice were used to demonstrate the hair revitalizing properties of a variety of low molecular weight, small molecule, non-immunosuppressive neuroimmunophilin FKBP ligands, including GPI 1605. C57 Black 6 mice, 55 to 75 days old, had an area of about 2 inches by 2 inches on their hindquarters shaved to remove all existing hair. Care was taken not to nick or cause abrasion to the underlying dermal layers. The animals were in anagen growth phase when shaved. Five animals per group were treated by topical administration with a vehicle, FK506, or one of the low molecular weight, small molecule, non-immunosuppressive neuroimmunophilin FKBP ligands (GPI 1605, 1046, 1312, 1572, 1389, 1511, and 1234) at a concentration of one micromole per milliliter to the shaved area. The animals were treated three times per week, and hair growth was evaluated 14 days after initiation of treatment. Hair growth was quantitated by the percent of shaved area covered by new hair growth, as scored by a blinded observer, on a scale of 0 (no growth) to five (complete hair regrowth in shaved area) . Figure 5 shows that after 14 days, the animals treated with vehicle exhibited the beginning of growth in small tufts. In contrast, animals treated with one of the low molecular weight, small molecule, non-immunosuppressive neuroimmunophilin FKBP ligands, including GPI 1605, exhibited dramatic hair growth. Example 5 A lotion comprising the following composition may be prepared. Into 95% ethanol are added an N-linked urea or carbamate of a heterocyclic thioester, α-tocopherol acetate, ethylene oxide (40 mole) adducts of hardened castor oil, perfume and a dye. The resulting mixture is stirred and dissolved, and purified water is added to the mixture to obtain a transparent liquid lotion. 5 ml of the lotion may be applied once or twice per day to a site having marked baldness or alopecia. Example 6 A lotion comprising the following composition shown may be prepared. Into 95% ethanol are added an N-linked urea or carbamate of a heterocyclic thioester, hinokitol, ethylene oxide (40 mole) adducts of hardened castor oil, perfume, and a dye. The resulting mixture is stirred, and purified water is added to the mixture to obtain a transparent liquid lotion. The lotion may be applied by spraying once to 4 times per day to a site having marked baldness or alopecia. Example 7 An emulsion may be prepared from A phase and B phase having the following compositions. The A phase and the B phase are respectively heated and melted and maintained at 80°c. Both phases are then mixed and cooled under stirring to normal temperature to obtain an emulsion. The emulsion may be applied by spraying once to four times per day to a site having marked baldness or alopecia. Example 8 A cream may be prepared from A phase and B phase having the following compositions. The A phase is heated and melted, and maintained at 70°c. The B phase is added into the A phase and the mixture is stirred to obtain an emulsion. The emulsion is then cooled to obtain a cream. The cream may be applied once to 4 times per day to a site having marked baldness or alopecia. Example 9 A liquid comprising the following composition may be prepared. Into ethanol are added polyoxypropylene butyl ether, propylene glycol, polyoxyethylene hardened castor oil, an N-linked urea or carbamate of a heterocyclic thioester, and perfume. The resulting mixture is stirred, and purified water is added to the mixture to obtain a liquid. The liquid may be applied once to 4 times per day to a site having marked baldness or alopecia. Example 10 A shampoo comprising the following composition may be prepared. Into 69.7 of purified water are added 5.0 g of sodium laurylsulfate, 5.0 g of triethanolamine laurylsulfate, 6.0 g of betaine lauryldimethylaminoacetate . Then a mixture obtained by adding 5.0 g of an N-linked urea or carbamate of a heterocyclic thioester, 5.0 g of polyethylene glycol, and 2.0 g of ethylene glycol distearate to 2.0 g of ethanol, followed by stirring, and 0.3 g of perfume are successively added. The resulting mixture is heated and subsequently cooled to obtain a shampoo. The shampoo may be used on the scalp once or twice per day. Example 11 A patient is suffering from alopecia senilis. An N-linked urea or carbamate of a heterocyclic thioester as identified above, or a pharmaceutical composition comprising the same, may be administered to the patient. Increased hair growth is expected to occur following treatment. Example 12 A patient is suffering from male pattern alopecia. An N-linked urea or carbamate of a heterocyclic thioester as identified above, or a pharmaceutical composition comprising the same, may be administered to the patient. Increased hair growth is expected to occur following treatment. Example 13 A patient is suffering from alopecia areata. An N-linked urea or carbamate of a heterocyclic thioester as identified above, or a pharmaceutical composition comprising the same, may be administered to the patient. Increased hair growth is expected to occur following treatment . Example 14 A patient is suffering from hair loss caused by skin lesions. An N-linked urea or carbamate of a heterocyclic thioester as identified above, or a pharmaceutical composition comprising the same, may be administered to the patient. Increased hair growth is expected to occur following treatment . Example 15 A patient is suffering from hair loss caused by tumors. An N-linked urea or carbamate of a heterocyclic thioester as identified above, or a pharmaceutical composition comprising the same, may be administered to the patient. Increased hair growth is expected to occur following treatment. Example 16 A patient is suffering from hair loss caused by a systematic disorder, such as a nutritional disorder or an internal secretion disorder. An N-linked urea or carbamate of a heterocyclic thioester as identified above, or a pharmaceutical composition comprising the same, may be administered to the patient. Increased hair growth is expected to occur following treatment. Example 17 A patient is suffering from hair loss caused by chemotherapy. An N-linked urea or carbamate of a heterocyclic thioester as identified above, or a pharmaceutical composition comprising the same, may be administered to the patient. Increased hair growth is expected to occur following treatment. Example 18 A patient is suffering from hair loss caused by radiation. An N-linked urea or carbamate of a heterocyclic thioester as identified above, or a pharmaceutical composition comprising the same, may be administered to the patient. Increased hair growth is expected to occur following treatment. The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention and all such modifications are intended to be included within the scope of the following claims.

Claims: WE CLAIM : 1. A method for treating alopecia or promoting hair growth in an animal, which comprises administering to said animal an effective amount of an N-linked urea or carbamate of a heterocyclic thioester. 2. The method of claim 1, wherein the N-linked urea or carbamate of a heterocyclic thioester is non- immunosuppressive . 3. The method of claim 1, wherein the N-linked urea or carbamate of a heterocyclic thioester has an affinity for an FKBP-type immunophilin. 4. The method of claim 3, wherein the FKBP-type immunophilin is FKBP-12. 5. The method of claim 1, wherein the N-linked urea or carbamate of a heterocyclic thioester is a compound of formula I or a pharmaceutically acceptable salt, ester, or solvate thereof, wherein: A and B, taken together with the nitrogen and carbon atoms to which they are respectively attached, form a 5-7 membered saturated or unsaturated heterocyclic ring containing, in addition to the nitrogen atom, one or more additional O, S, SO, S0 2 , N, NH, or NR 3 heteroatom (s) ; X is either O or S; Y is a direct bond, straight or branched chain alkyl, or C 2 -C 6 straight or branched chain alkenyl, wherein any carbon atom of said alkyl or alkenyl is optionally substituted in one or more position(s) with amino, halo, haloalkyl, thiocarbonyl, ester, thioester, alkoxy, alkenoxy, cyano, nitro, imino, alkylamino, aminoalkyl, sulfhydryl, thioalkyl, sulfonyl, or oxygen to form a carbonyl, or wherein any carbon atom of said alkyl or alkenyl is optionally replaced with 0, NH, NR 3 , S, SO, or S0 2 ; R 3 is selected from the group consisting of hydrogen, C 1 -C 6 straight or branched chain alkyl, C 3 -C 6 straight or branched chain alkenyl or alkynyl, and C x - C 4 bridging alkyl wherein a bridge is formed between the nitrogen and a carbon atom of said alkyl or alkenyl chain containing said heteroatom to form a ring, wherein said ring is optionally fused to an Ar group ; Ar is an alicyclic or aromatic, mono-, bi- or tricyclic, carbo- or heterocyclic ring, wherein the ring is either unsubstituted or substituted with one or more substituent (s) ; wherein the individual ring size is 5-8 members; wherein said heterocyclic ring contains 1-6 heteroatom (s) independently selected from the group consisting of 0, N, and S; and wherein said aromatic or tertiary alkyl amine is optionally oxidized to a corresponding N-oxide; Z is a direct bond, straight or branched chain alkyl, or C 2 -C 6 straight or branched chain alkenyl , wherein any carbon atom of said alkyl or alkenyl is optionally substituted in one or more position (s) with amino, halo, haloalkyl, thiocarbonyl, ester, thioester, alkoxy, alkenoxy, cyano, nitro, imino, alkylamino, aminoalkyl, sulfhydryl, thioalkyl, sulfonyl, or oxygen to form a carbonyl, or wherein any carbon atom of said alkyl or alkenyl is optionally replaced with O, NH, NR 3 , S, SO, or S0 2 ; C and D are independently hydrogen, Ar, C 1 -C 3 straight or branched chain alkyl, or C 2 -C 6 straight or branched chain alkenyl; wherein said alkyl or alkenyl is optionally substituted with one or more substituent (s) independently selected from the group consisting of C 3 -C 8 cycloalkyl, C 5 -C 7 cycloalkenyl, hydroxy, carbonyl oxygen, and Ar; wherein said alkyl, alkenyl, cycloalkyl or cycloalkenyl is optionally substituted with alkyl, C 2 -C 6 alkenyl, hydroxy, amino, halo, haloalkyl, thiocarbonyl, ester, thioester, alkoxy, alkenoxy, cyano, nitro, imino, _ alkylamino, aminoalkyl, sulfhydryl, thioalkyl, or sulfonyl; wherein any carbon atom of said alkyl or alkenyl is optionally substituted in one or more position (s) with oxygen to form a carbonyl; or wherein any carbon atom of said alkyl or alkenyl is optionally replaced with 0, NH, NR 3 , S, SO, or S0 2 ; W is 0 or S; and U is either 0 or N, provided that: when U is O, then is a lone pair of . electrons and R 2 is selected from the group consisting of Ar, C 3 -C 8 cycloalkyl, C 1 -C 6 straight or branched chain alkyl, and C 2 -C 6 straight or branched chain alkenyl, wherein said alkyl or alkenyl is optionally substituted with one or more substituent (s) independently selected from the group consisting of Ar and C 3 -C 8 cycloalkyl; and when U is N, then R 1 and R 2 are independently selected from the group consisting of hydrogen, Ar, C 3 -C 8 cycloalkyl, straight or branched chain alkyl, and C 2 -C 6 straight or branched chain alkenyl, wherein said alkyl or alkenyl is substituted with one or more substituent (s) independently selected from the group consisting of Ar and C 3 -C 8 cycloalkyl; or R x and R 2 are taken together to form a heterocyclic 5 or 6 membered ring selected from the group consisting of pyrrolidine, imidazolidine, pyrazolidine, piperidine, and piperazine. 6. The method of claim 5, wherein Ar is selected from the group consisting of naphthyl, indolyl, furyl, thiazolyl, thienyl, pyridyl, quinolinyl, isoquinolinyl, fluorenyl, and phenyl. 7. The method of claim 1, wherein the N-linked urea or carbamate of a heterocyclic thioester is a compound of formula II or a pharmaceutically acceptable salt, ester, or solvate thereof, wherein: E, F, G and J are independently selected from the group consisting of CH 2 , 0, S, SO, S0 2 , NH and NR 3 ; X is either 0 or S ; Y is a direct bond, straight or branched chain alkyl or C 2 -C 6 straight or branched chain alkenyl, wherein any carbon atom of said alkyl or alkenyl is optionally substituted in one or more position (s) with oxygen to form a carbonyl, or wherein any carbon atom of said alkyl or alkenyl is optionally replaced with 0, NH, NR 3 , S, SO, or S0 2 ; R 3 is selected from the group consisting of hydrogen, straight or branched chain alkyl, C 3 -C 4 straight or branched chain alkenyl or alkynyl, and C^ C 4 bridging alkyl wherein a bridge is formed between the nitrogen and a carbon atom of said alkyl or alkenyl chain containing said heteroatom to form a ring, wherein said ring is optionally fused to an Ar group ; Ar is an alicyclic or aromatic, mono-, bi- or tricyclic, carbo- or heterocyclic ring, wherein the ring is either unsubstituted or substituted with one or more substituent (s) ; wherein the individual ring size is 5-8 members; wherein said heterocyclic ring contains 1-6 heteroatom(s) independently selected from the group consisting of 0, N, and S; and wherein said aromatic or tertiary alkyl amine is optionally oxidized to a corresponding N-oxide; Z is a direct bond, straight or branched chain alkyl, or C 2 -C 6 straight or branched chain alkenyl , wherein any carbon atom of said alkyl or alkenyl is optionally substituted in one or more position (s) with oxygen to form a carbonyl, or wherein any carbon atom of said alkyl or alkenyl is optionally replaced with O, NH, NR 3 , S, SO, or S0 2 ; C and D are independently hydrogen, Ar, C^C g straight or branched chain alkyl, or C 2 -C 6 straight or branched chain alkenyl ; wherein said alkyl or alkenyl is optionally substituted with one or more substituent (s) independently selected from the group consisting of C 3 -C 8 cycloalkyl, C 5 -C 7 cycloalkenyl, hydroxy, carbonyl oxygen, and Ar; wherein said alkyl, alkenyl, cycloalkyl or cycloalkenyl is optionally substituted with C^ , alkyl, C 2 -C 4 alkenyl, or hydroxy; wherein any carbon atom of said alkyl or alkenyl is optionally substituted in one or more position (s) with oxygen to form a carbonyl; or wherein any carbon atom of said alkyl or alkenyl is optionally replaced with O, NH, NR 3 , S, SO, or S0 2 ; W is 0 or S; and U is either O or N, provided that: when U is 0, then R 1 is a lone pair of electrons and R 2 is selected from the group consisting of Ar, C 3 -C 8 cycloalkyl, C--C 6 straight or branched chain alkyl, and C 2 -C 6 straight or branched chain alkenyl, wherein said alkyl or alkenyl is optionally substituted with one or more substituent (s) independently selected from the group consisting of Ar and C 3 -C 8 cycloalkyl; and when U is N, then R λ and R 2 are independently selected from the group consisting of hydrogen, Ar, C 3 -C 8 cycloalkyl, straight or branched chain alkyl, and C 2 -C 6 straight or branched chain alkenyl, wherein said alkyl or alkenyl is optionally substituted with one or more substituent (s) independently selected from the group consisting of Ar and C 3 -C 8 cycloalkyl; or R 1 and R 2 are taken together to form a heterocyclic 5 or 6 membered ring selected from the group consisting of pyrrolidine, imidazolidine, pyrazolidine, piperidine, and piperazine . 8. The method of claim 7, wherein Ar is selected from the group consisting of naphthyl, indolyl , furyl , thiazolyl , thienyl , pyridyl , and phenyl . 9. The method of claim 1, wherein the N-linked urea or carbamate of a heterocyclic thioester is a compound of formula III or a pharmaceutically acceptable salt, ester, or solvate thereof, wherein: E, F, and G are independently selected from the group consisting of CH 2 , O, S, SO, S0 2 , NH and NR 3 ; X is either O or S ; Y is a direct bond, straight or branched chain alkyl, or C 2 -C 6 straight or branched chain alkenyl , wherein any carbon atom of said alkyl or alkenyl is optionally substituted in one or more position (s) with oxygen to form a carbonyl, or wherein any carbon atom of said alkyl or alkenyl is optionally replaced with 0, NH, NR 3 , S, SO, or S0 2 ; R 3 is selected from the group consisting of hydrogen, C 1 -C 4 straight or branched chain alkyl, C 3 -C 4 straight or branched chain alkenyl or alkynyl, and C τ - C 4 bridging alkyl wherein a bridge is formed between the nitrogen and a carbon atom of said alkyl or alkenyl chain containing said heteroatom to form a ring, wherein said ring is optionally fused to an Ar group ; Ar is an alicyclic or aromatic, mono-, bi- or tricyclic, carbo- or heterocyclic ring, wherein the ring is either unsubstituted or substituted with one or more substituent (s) ; wherein the individual ring size is 5-8 members; wherein said heterocyclic ring contains 1-6 heteroatom (s) independently selected from the group consisting of 0, N, and S; and wherein said aromatic or tertiary alkyl amine is optionally oxidized to a corresponding N-oxide; Z is a direct bond, straight or branched chain alkyl, or C 2 -C 6 straight or branched chain alkenyl , wherein any carbon atom of said alkyl or alkenyl is optionally substituted in one or more position (s) with oxygen to form a carbonyl, or wherein any carbon atom of said alkyl or alkenyl is optionally replaced with 0, NH, NR 3 , S, SO, or S0 2 ; C and D are independently hydrogen, Ar, straight or branched chain alkyl, C 2 -C 6 straight or branched chain or alkenyl ; wherein said alkyl or alkenyl is optionally substituted with one or more substituent (s) independently selected from the group consisting of C 3 -C 8 cycloalkyl, C 5 -C 7 cycloalkenyl, hydroxy, carbonyl oxygen, and Ar; wherein said alkyl, alkenyl, cycloalkyl or cycloalkenyl is optionally substituted with C- t -Cj alkyl, C 2 -C 4 alkenyl, or hydroxy; wherein any carbon atom of said alkyl or alkenyl is optionally substituted in one or more position (s) with oxygen to form a carbonyl; or wherein any carbon atom of said alkyl or alkenyl is optionally replaced with O, NH, NR 3 , S, SO, or S0 2 ; W is O or S; and U is either 0 or N, provided that: when U is O, then R x is a lone pair of electrons and R 2 is selected from the group consisting of Ar, C 3 -C 8 cycloalkyl, straight or branched chain alkyl, and C 2 -C 6 straight or branched chain alkenyl, wherein said alkyl or alkenyl is optionally substituted with one or more substituent (s) independently selected from the group consisting of Ar and C 3 -C 8 cycloalkyl; and when U is N, then R x and R 2 are independently selected from the group consisting of hydrogen, Ar, C 3 -C 8 cycloalkyl, straight or branched chain alkyl, and C 2 -C 6 straight or branched chain alkenyl, wherein said alkyl or alkenyl is optionally substituted with one or more substituent (s) independently selected from the group consisting of Ar and C 3 -C 8 cycloalkyl; or R ± and R 2 are taken together to form a heterocyclic 5 or 6 membered ring selected from the group consisting of pyrrolidine, imidazolidine, pyrazolidine, piperidine, and piperazine. 10. The method of claim 9, wherein Ar is selected from the group consisting of naphthyl, indolyl, furyl, thiazolyl, thienyl, pyridyl, and phenyl . 11. The method of claim 1, wherein the N-linked urea or carbamate of a heterocyclic thioester is a compound of formula IV or a pharmaceutically acceptable salt, ester, or solvate thereof, wherein: n is 1, 2 or 3; X is either 0 or S; Y is a direct bond, C^Cg straight or branched chain alkyl, or C 2 -C 6 straight or branched chain alkenyl , wherein any carbon atom of said alkyl or alkenyl is optionally substituted in one or more position (s) with oxygen to form a carbonyl, or wherein any carbon atom of said alkyl or alkenyl is optionally replaced with 0, NH, NR 3 , S, SO, or S0 2 ; R 3 is selected from the group consisting of hydrogen, C^ straight or branched chain alkyl, C 3 -C 4 straight or branched chain alkenyl or alkynyl , and C x - C 4 bridging alkyl wherein a bridge is formed between the nitrogen and a carbon atom of said alkyl or alkenyl chain containing said heteroatom to form a ring, wherein said ring is optionally fused to an Ar group ; Ar is an alicyclic or aromatic, mono-, bi- or tricyclic, carbo- or heterocyclic ring, wherein the ring is either unsubstituted or substituted with one or more substituent (s) ; wherein the individual ring size is 5-8 members; wherein said heterocyclic ring contains 1-6 heteroatom (s) independently selected from the group consisting of O, N, and S; and wherein said aromatic or tertiary alkyl amine is optionally oxidized to a corresponding N-oxide; Z is a direct bond, straight or branched chain alkyl, or C 2 -C 6 straight or branched chain alkenyl , wherein any carbon atom of said alkyl or alkenyl is optionally substituted in one or more position (s) with oxygen to form a carbonyl, or wherein any carbon atom of said alkyl or alkenyl is optionally replaced with 0, NH, NR 3 , S, SO, or S0 2 ; C and D are independently hydrogen, Ar, straight or branched chain alkyl, or C 2 -C 6 straight or branched chain alkenyl; wherein said alkyl or alkenyl is optionally substituted with one or more substituent (s) independently selected from the group consisting of C 3 -C 8 cycloalkyl, C 5 -C 7 cycloalkenyl, hydroxy, carbonyl oxygen, and Ar; wherein said alkyl, alkenyl, cycloalkyl, or cycloalkenyl is optionally substituted with C 1 -C 4 alkyl, C 2 -C 4 alkenyl, or hydroxy; wherein any carbon atom of said alkyl or alkenyl is optionally substituted in one or more position (s) with oxygen to form a carbonyl; or wherein any carbon atom of said alkyl or alkenyl is optionally replaced with 0, NH, NR 3 , S, SO, or S0 2 ; W is 0 or S; and U is either 0 or N, provided that: when U is 0, then R 1 is a lone pair of electrons and R 2 is selected from the group consisting of Ar, C 3 -C 8 cycloalkyl, C 1 -C 6 straight or branched chain alkyl, and C 2 -C 6 straight or branched chain or alkenyl, wherein said alkyl or alkenyl is optionally substituted with one or_ more substituent (s) independently selected from the group consisting of Ar and C 3 -C 8 cycloalkyl; and when U is N, then R 1 and R 2 are independently selected from the group consisting of hydrogen, Ar, C 3 -C 8 cycloalkyl, C- L -Cg straight or branched chain alkyl, and C 2 -C 6 straight or branched chain alkenyl, wherein said alkyl or alkenyl is optionally substituted with one or more substituent (s) independently selected from the group consisting of Ar and C 3 -C 8 cycloalkyl; or R and R 2 are taken together to form a heterocyclic 5 or 6 membered ring selected from the group consisting of pyrrolidine, imidazolidine, pyrazolidine, piperidine, and piperazine . 12. The method of claim 11, wherein Ar is selected from the group consisting of naphthyl, indolyl , furyl , thiazolyl , thienyl , pyridyl , and phenyl . 13. The method of claim 11, wherein: n is 1 or 2; Y is (CH 2 ) 2 or a direct bond; Z is CH; C is 3 -pyridyl, 4-methoxyphenyl , phenyl, or 2- phenylethyl ; D is hydrogen, phenyl or 2-phenylethyl ; R 1 is hydrogen; and R. is 2-methylbutyl, 1, 1-dimethylpropyl , cyclohexyl, 1-adamantyl, or phenyl. 14. The method of claim 13, wherein the compound is selected from the group consisting of: 3- (3-Pyridyl) - 1 -propyl-2S-l- [ (2-methylbutyl) carbamoyl] pyrrolidine-2 -carboxylate; 3- (3-Pyridyl) -1-propyl -2S- 1 - [ (1' , 1' - Dimethylpropyl) carbamoyl] pyrrolidine-2 -carboxylate; 3- (3-Pyridyl) - 1 -propyl - 2 S - 1 - [ (cyclohexyl) thiocarbamoyl] pyrrolidine-2 -carboxylate ; and pharmaceutically acceptable salts, esters, and solvates thereof. 15. The method of claim 1, wherein the N-linked urea or carbamate of a heterocyclic thioester is a compound of formula V or a pharmaceutically acceptable salt, ester, or solvate thereof, wherein: V is C, N, or S; Y is a direct bond, straight or branched chain alkyl, or C 2 -C 6 straight or branched chain alkenyl , wherein any carbon atom of said alkyl or alkenyl is optionally substituted in one or more position(s) with amino, halo, haloalkyl, thiocarbonyl, ester, thioester, alkoxy, alkenoxy, cyano, nitro, imino, alkylamino, aminoalkyl, sulfhydryl, thioalkyl, sulfonyl, or oxygen to form a carbonyl, or wherein any carbon atom of said alkyl or alkenyl is optionally replaced with 0, NH, NR 3 , S, SO, or S0 2 ; R 3 is selected from the group consisting of hydrogen, C j -Cg straight or branched chain alkyl, C 3 -C 6 straight or branched chain alkenyl or alkynyl, and C x - C 4 bridging alkyl wherein a bridge is formed between the nitrogen and a carbon atom of said alkyl or alkenyl chain containing said heteroatom to form a ring, wherein said ring is optionally fused to an Ar group ; Ar is an alicyclic or aromatic, mono-, bi- or tricyclic, carbo- or heterocyclic ring, wherein the ring is either unsubstituted or substituted with one or more substituent (s) ; wherein the individual ring size is 5-8 members; wherein said heterocyclic ring contains 1-6 heteroatom (s) independently selected from the group consisting of 0, N, and S ; and wherein said aromatic or tertiary alkyl amine is optionally oxidized to a corresponding N-oxide; Z is a direct bond, Ci-Cg straight or branched chain alkyl, or C 2 -C 6 straight or branched chain alkenyl , wherein any carbon atom of said alkyl or alkenyl is optionally substituted in one or more position(s) with amino, halo, haloalkyl, thiocarbonyl, ester, thioester, alkoxy, alkenoxy, cyano, nitro, imino, alkylamino, aminoalkyl, sulfhydryl, thioalkyl, sulfonyl, or oxygen to form a carbonyl, or wherein any carbon atom of said alkyl or alkenyl is optionally replaced with 0, NH, NR 3 , S, SO, or S0 2 ; C and D are independently hydrogen, Ar, C x -C 6 straight or branched chain alkyl, or C 2 -C 6 straight or branched chain alkenyl; wherein said alkyl or alkenyl is optionally substituted with one or more substituent (s) independently selected from the group consisting of C 3 -C 8 cycloalkyl, C 5 -C 7 cycloalkenyl, hydroxy, carbonyl oxygen, and Ar; wherein said alkyl, alkenyl, cycloalkyl or cycloalkenyl is optionally substituted with alkyl, C 2 -C 6 alkenyl, hydroxy, amino, halo, haloalkyl, thiocarbonyl, ester, thioester, alkoxy, alkenoxy, cyano, nitro, imino, alkylamino, aminoalkyl, sulfhydryl, thioalkyl, or sulfonyl; wherein any carbon atom of said alkyl or alkenyl is optionally substituted in one or more position (s) with oxygen to form a carbonyl; or wherein any carbon atom of said alkyl or alkenyl is optionally replaced with 0, NH, NR 3 , S, SO, or S0 2 ; and A, B, Rl, R2, U, W, and X are as otherwise defined in claim 5 above. 16. A pharmaceutical composition which comprises : (i) an effective amount of an N-linked urea or carbamate of a heterocyclic thioester for treating alopecia or promoting hair growth in an animal; and (ii) a pharmaceutically acceptable carrier. 17. The pharmaceutical composition of claim 16, wherein the N-linked urea or carbamate of a heterocyclic thioester is non-immunosuppressive . 18. The pharmaceutical composition of claim 16, wherein the N-linked urea or carbamate of a heterocyclic thioester has an affinity for an FKBP- type immunophilin. 19. The pharmaceutical composition of claim 18, wherein the FKBP-type immunophilin is FKBP-12. 20. The pharmaceutical composition of claim 16, wherein the N-linked urea or carbamate of a heterocyclic thioester is a compound of formula I or a pharmaceutically acceptable salt, ester, or solvate thereof, wherein: A and B, taken together with the nitrogen and carbon atoms to which they are respectively attached, form a 5-7 membered saturated or unsaturated heterocyclic ring containing, in addition to the nitrogen atom, one or more additional O, S, SO, S0 2 , N, NH, or NR 3 heteroatom (s) ; X is either 0 or S; Y is a direct bond, C 1 -C 6 straight or branched chain alkyl, or C 2 -C 6 straight or branched chain alkenyl, wherein any carbon atom of said alkyl or alkenyl is optionally substituted in one or more position(s) with amino, halo, haloalkyl, thiocarbonyl, ester, thioester, alkoxy, alkenoxy, cyano, nitro, imino, alkylamino, aminoalkyl, sulfhydryl, thioalkyl, sulfonyl, or oxygen to form a carbonyl, or wherein any carbon atom of said alkyl or alkenyl is optionally replaced with 0, NH, NR 3 , S, SO, or S0 2 ; R 3 is selected from the group consisting of hydrogen, straight or branched chain alkyl, C 3 -C 3 straight or branched chain alkenyl or alkynyl, and C x - C 4 bridging alkyl wherein a bridge is formed between _ the nitrogen and a carbon atom of said alkyl or alkenyl chain containing said heteroatom to form a ring, wherein said ring is optionally fused to an Ar group ; Ar is an alicyclic or aromatic, mono-, bi- or tricyclic, carbo- or heterocyclic ring, wherein the ring is either unsubstituted or substituted with one or more substituent (s) ; wherein the individual ring size is 5-8 members; wherein said heterocyclic ring contains 1-6 heteroatom (s) independently selected from the group consisting of O, N, and S; and wherein said aromatic or tertiary alkyl amine is optionally oxidized to a corresponding N-oxide; Z is a direct bond, straight or branched chain alkyl, or C 2 -C 6 straight or branched chain alkenyl, wherein any carbon atom of said alkyl or alkenyl is optionally substituted in one or more position(s) with amino, halo, haloalkyl, thiocarbonyl, ester, thioester, alkoxy, alkenoxy, cyano, nitro, imino, alkylamino, aminoalkyl, sulfhydryl, thioalkyl, sulfonyl, or oxygen to form a carbonyl, or wherein any carbon atom of said alkyl or alkenyl is optionally replaced with O, NH, NR 3 , S, SO, or S0 2 ; C and D are independently hydrogen, Ar, C--C 6 straight or branched chain alkyl, or C 2 -C 6 straight or branched chain alkenyl ; wherein said alkyl or alkenyl is optionally substituted with one or more substituent (s) independently selected from the group consisting of C 3 -C 8 cycloalkyl, C 5 -C 7 cycloalkenyl, hydroxy, carbonyl oxygen, and Ar; wherein said alkyl, alkenyl, cycloalkyl or cycloalkenyl is optionally substituted with C^Cg alkyl, C 2 -C 6 alkenyl, hydroxy, amino, halo, haloalkyl, thiocarbonyl, ester, thioester, alkoxy, alkenoxy, cyano, nitro, imino, alkylamino, aminoalkyl, sulfhydryl, thioalkyl, or sulfonyl; wherein any carbon atom of said alkyl or alkenyl is optionally substituted in one or more position(s) with oxygen to form a carbonyl; or wherein any carbon atom of said alkyl or alkenyl is optionally replaced with 0, NH, NR 3 , S, SO, or S0 2 ; W is 0 or S; and U is either 0 or N, provided that: when U is 0, then R 1 is a lone pair of electrons and R 2 is selected from the group consisting of Ar, C 3 -C 8 cycloalkyl, C- L -Cg straight or branched chain alkyl, and C 2 -C 6 straight or branched chain alkenyl, wherein said alkyl or alkenyl is optionally substituted with one or more substituent (s) independently selected from the group consisting of Ar and C 3 -C 8 cycloalkyl; and when U is N, then R λ and R 2 are independently selected from the group consisting of hydrogen, Ar, C 3 -C 8 cycloalkyl, C^C g straight or branched chain alkyl, and C 2 -C 6 straight or branched chain alkenyl, wherein said alkyl or alkenyl is substituted with one or more substituent (s) independently selected from the group consisting of Ar and C 3 -C 8 cycloalkyl; or R 1 and R 2 are taken together to form a heterocyclic 5 or 6 membered ring selected from the group consisting of pyrrolidine, imidazolidine, pyrazolidine, piperidine, and piperazine. 21. The pharmaceutical composition of claim 20, wherein Ar is selected from the group consisting of naphthyl, indolyl, furyl, thiazolyl, thienyl, pyridyl, quinolinyl, isoquinolinyl, fluorenyl, and phenyl. 22. The pharmaceutical composition of claim 16, wherein the N-linked urea or carbamate of a heterocyclic thioester is a compound of formula II or a pharmaceutically acceptable salt, ester, or solvate thereof, wherein: E, F, G and J are independently CH 2 , 0, S, SO, S0 2 , NH or NR 3 ; X is either O or S ; Y is a direct bond, straight or branched chain alkyl or C 2 -C 6 straight or branched chain alkenyl, wherein any carbon atom of said alkyl or alkenyl is optionally substituted in one or more position (s) with oxygen to form a carbonyl, or wherein any carbon atom of said alkyl or alkenyl is optionally replaced with 0, NH, NR 3 , S, SO, or S0 2 ; R 3 is selected from the group consisting of hydrogen, C 1 -C 4 straight or branched chain alkyl, C 3 -C 4 straight or branched chain alkenyl or alkynyl , and C x - C 4 bridging alkyl wherein a bridge is formed between the nitrogen and a carbon atom of said alkyl or alkenyl chain containing said heteroatom to form a ring, wherein said ring is optionally fused to an Ar group ; Ar is an alicyclic or aromatic, mono-, bi- or tricyclic, carbo- or heterocyclic ring, wherein the ring is either unsubstituted or substituted with one or more substituent (s) ; wherein the individual ring size is 5-8 members; wherein said heterocyclic ring contains 1-6 heteroatom(s) independently selected from the group consisting of 0, N, and S ; and wherein said aromatic or tertiary alkyl amine is optionally oxidized to a corresponding N-oxide; Z is a direct bond, straight or branched chain alkyl, or C 1 -C 6 straight or branched chain alkenyl, wherein any carbon atom of said alkyl or alkenyl is optionally substituted in one or more position (s) with oxygen to form a carbonyl, or wherein any carbon atom of said alkyl or alkenyl is optionally replaced with 0, NH, NR 3 , S, SO, or S0 2 ; C and D are independently hydrogen, Ar, straight or branched chain alkyl, or C 2 -C 6 straight or branched chain alkenyl; wherein said alkyl or alkenyl is optionally substituted with one or more substituent (s) independently selected from the group consisting of C 3 -C 8 cycloalkyl, C 5 -C 7 cycloalkenyl, hydroxy, carbonyl oxygen, and Ar; wherein said alkyl, alkenyl, cycloalkyl or cycloalkenyl is optionally substituted with C^ alkyl, C 2 -C 4 alkenyl, or hydroxy; wherein any carbon atom of said alkyl or alkenyl is optionally substituted in one or more position (s) with oxygen to form a carbonyl; or wherein any carbon atom of said alkyl or alkenyl is optionally replaced with 0, NH, NR 3 , S, SO, or S0 2 ; W is 0 or S; and U is either 0 or N, provided that: when U is 0, then R λ is a lone pair of electrons and R 2 is selected from the group consisting of Ar, C 3 -C 8 cycloalkyl, straight or branched chain alkyl, and C 2 -C 6 straight or branched chain alkenyl, wherein said alkyl or alkenyl is optionally substituted with one or more substituent (s) independently selected from the group consisting of Ar and C 3 -C 8 cycloalkyl; and when U is N, then R x and R 2 are independently selected from the group consisting of hydrogen, Ar, C 3 -C 8 cycloalkyl, straight or branched chain alkyl, and C 2 -C 6 straight or branched chain alkenyl, wherein said alkyl or alkenyl is optionally substituted with one or more substituent (s) independently selected from the group consisting of Ar and C 3 -C 8 cycloalkyl; or R x and R 2 are taken together to form a heterocyclic 5 or 6 membered ring selected from the group consisting of pyrrolidine, imidazolidine, pyrazolidine, piperidine, and piperazine . 23. The pharmaceutical composition of claim 22, wherein Ar is selected from the group consisting of naphthyl, indolyl, furyl, thiazolyl, thienyl, pyridyl, and phenyl . 24. The pharmaceutical composition of claim 16, wherein the N-linked urea or carbamate of a heterocyclic thioester is a compound of formula III or a pharmaceutically acceptable salt, ester, or solvate thereof, wherein: E, F, and G are independently CH 2 , 0, S, SO, S0 2 , NH or NR 3 ; X is either 0 or S; Y is a direct bond, straight or branched chain alkyl, or C 2 -C 6 straight or branched chain alkenyl , wherein any carbon atom of said alkyl or alkenyl is optionally substituted in one or more position (s) with oxygen to form a carbonyl, or wherein any carbon atom of said alkyl or alkenyl is optionally replaced with 0, NH, NR 3 , S, SO, or S0 2 ; R 3 is selected from the group consisting of hydrogen, C 1 -C 4 straight or branched chain alkyl, C 3 -C 4 straight or branched chain alkenyl or alkynyl , and C x - C 4 bridging alkyl wherein a bridge is formed between the nitrogen and a carbon atom of said alkyl or alkenyl chain containing said heteroatom to form a ring, wherein said ring is optionally fused to an Ar group ; Ar is an alicyclic or aromatic, mono-, bi- or tricyclic, carbo- or heterocyclic ring, wherein the ring is either unsubstituted or substituted with one or more substituent (s) ; wherein the individual ring size is 5-8 members; wherein said heterocyclic ring contains 1-6 heteroatom (s) independently selected from the group consisting of 0, N, and S; and wherein said aromatic or tertiary alkyl amine is optionally oxidized to a corresponding N-oxide; Z is a direct bond, Ci-Cg straight or branched chain alkyl, or C 2 -C 6 straight or branched chain alkenyl, wherein any carbon atom of said alkyl or alkenyl is optionally substituted in one or more position (s) with oxygen to form a carbonyl, or wherein any carbon atom of said alkyl or alkenyl is optionally replaced with 0, NH, NR 3 , S, SO, or S0 2 ; C and D are independently hydrogen, Ar, straight or branched chain alkyl, C 2 -C 6 straight or branched chain or alkenyl ; wherein said alkyl or alkenyl is optionally substituted with one or more substituent (s) independently selected from the group consisting of C 3 -C 8 cycloalkyl, C 5 -C 7 cycloalkenyl, hydroxy, carbonyl oxygen, and Ar; wherein said alkyl, alkenyl, cycloalkyl or cycloalkenyl is optionally substituted with C x -C 4 alkyl, C 2 -C 4 alkenyl, or hydroxy; wherein any carbon atom of said alkyl or alkenyl is optionally substituted in one or more position (s) with oxygen to form a carbonyl; or wherein any carbon atom of said alkyl or alkenyl is optionally replaced with 0, NH, NR 3 , S, SO, or S0 2 ; W is 0 or S; and U is either 0 or N, provided that: when U is 0, then R x is a lone pair of electrons and R 2 is selected from the group consisting of Ar, C 3 -C 8 cycloalkyl, straight or branched chain alkyl, and C 2 -C 6 straight or branched chain alkenyl, wherein said alkyl or alkenyl is optionally substituted with one or more substituent (s) independently selected from the group consisting of Ar and C 3 -C 8 cycloalkyl; and when U is N, then R 1 and R 2 are independently selected from the group consisting of hydrogen, Ar, C 3 -C 8 cycloalkyl, straight or branched chain alkyl, and C 2 -C 6 straight or branched chain alkenyl, wherein said alkyl or alkenyl is optionally substituted with one or more substituent (s) independently selected from the group consisting of Ar and C 3 -C 8 cycloalkyl; or R- L and R 2 are taken together to form a heterocyclic 5 or 6 membered ring selected from the group consisting of pyrrolidine, imidazolidine, pyrazolidine, piperidine, and piperazine . 25. The pharmaceutical composition of claim 24, wherein Ar is selected from the group consisting of naphthyl , indolyl , furyl , thiazolyl , thienyl , pyridyl , and phenyl . 26. The pharmaceutical composition of claim 16, wherein the N-linked urea or carbamate of a heterocyclic thioester is a compound of formula IV or a pharmaceutically acceptable salt, ester, or solvate thereof, wherein: n is 1, 2 or 3; X is either 0 or S; Y is a direct bond, C- L -Cg straight or branched chain alkyl, or C 2 -C 6 straight or branched chain alkenyl, wherein any carbon atom of said alkyl or alkenyl is optionally substituted in one or more position (s) with oxygen to form a carbonyl, or wherein any carbon atom of said alkyl or alkenyl is optionally replaced with O, NH, NR 3 , S, SO, or S0 2 ; R 3 is selected from the group consisting of hydrogen, C^^ straight or branched chain alkyl, C 3 -C 4 straight or branched chain alkenyl or alkynyl , and C x - C 4 bridging alkyl wherein a bridge is formed between the nitrogen and a carbon atom of said alkyl or alkenyl chain containing said heteroatom to form a ring, wherein said ring is optionally fused to an Ar group ; Ar is an alicyclic or aromatic, mono-, bi- or tricyclic, carbo- or heterocyclic ring, wherein the ring is either unsubstituted or substituted with one_ or more substituent (s) ; wherein the individual ring size is 5-8 members; wherein said heterocyclic ring contains 1-6 heteroatom (s) independently selected from the group consisting of 0, N, and S; and wherein said aromatic or a tertiary alkyl amine is optionally oxidized to a corresponding N-oxide; Z is a direct bond, straight or branched chain alkyl, or C 2 -C 6 straight or branched chain alkenyl, wherein any carbon atom of said alkyl or alkenyl is optionally substituted in one or more position (s) with oxygen to form a carbonyl, or wherein any carbon atom of said alkyl or alkenyl is optionally replaced with 0, NH, NR 3 , S, SO, or S0 2 ; C and D are independently hydrogen, Ar, C j -Cg straight or branched chain alkyl, or C 2 -C 6 straight or branched chain alkenyl; wherein said alkyl or alkenyl is optionally substituted with one or more substituent (s) independently selected from the group consisting of C 3 -C 8 cycloalkyl, C 5 -C 7 cycloalkenyl, hydroxy, carbonyl oxygen, and Ar; wherein said alkyl, alkenyl, cycloalkyl, or cycloalkenyl is optionally substituted with C x -C 4 alkyl, C 2 -C 4 alkenyl, or hydroxy; wherein any carbon atom of said alkyl or alkenyl is optionally substituted in one or more position (s) with oxygen to form a carbonyl ; or wherein any carbon atom of said alkyl or alkenyl is optionally replaced with O, NH, NR 3 , S, SO, or S0 2 ; W is 0 or S; and U is either O or N, provided that: when U is 0, then R 1 is a lone pair of electrons and R 2 is selected from the group consisting of Ar, C 3 -C 8 cycloalkyl, C x -Cg straight or branched chain alkyl, and C 2 -C 6 straight or branched chain or alkenyl , wherein said alkyl or alkenyl is optionally substituted with one or more substituent (s) independently selected from the group consisting of Ar and C 3 -C 8 cycloalkyl; and when U is N, then R x and R 2 are independently selected from the group consisting of hydrogen, Ar, C 3 -C 8 cycloalkyl, straight or branched chain alkyl, and C 2 -C 6 straight or branched chain alkenyl, wherein said alkyl or alkenyl is optionally substituted with one or more substituent (s) independently selected from the group consisting of Ar and C 3 -C 8 cycloalkyl; or R- L and R 2 are taken together to form a heterocyclic 5 or 6 membered ring selected from the group consisting of pyrrolidine, imidazolidine, pyrazolidine, piperidine, and piperazine . 27. The pharmaceutical composition of claim 26, wherein Ar is selected from the group consisting of naphthyl, indolyl, furyl, thiazolyl, thienyl, pyridyl, and phenyl . 28. The pharmaceutical composition of claim 26, wherein: n is 1 or 2; Y is (CH 2 ) 2 or a direct bond; Z is CH; C is 3 -pyridyl, 4-methoxyphenyl , phenyl, or 2- phenylethyl; D is hydrogen, phenyl or 2-phenylethyl ; R 1 is hydrogen; and R 2 is 2-methylbutyl, 1, 1-dimethylpropyl , cyclohexyl, 1-adamantyl, or phenyl. 29. The pharmaceutical composition of claim 28, wherein the compound is selected from the group consisting of: 3- (3-Pyridyl) - 1 -propyl-2S-l- [ (2-methylbutyl) carbamoyl] pyrrolidine-2 -carboxylate; 3- (3-Pyridyl) -1-propyl -2S- 1- [ (1' , 1' - Dimethylpropyl ) carbamoyl] pyrrolidine-2 -carboxylate ; 3- (3-Pyridyl) - 1 -propyl - 2 S - 1 - [ (cyclohexyl) thiocarbamoyl] pyrrolidine-2 -carboxylate; and pharmaceutically acceptable salts, esters, and solvates thereof . 30. The pharmaceutical composition of claim 16, wherein the N-linked urea or carbamate of a heterocyclic thioester is a compound of formula V or a pharmaceutically acceptable salt, ester, or solvate thereof, wherein: V is C, N, or S; Y is a direct bond, straight or branched chain alkyl, or C 2 -C 6 straight or branched chain alkenyl , wherein any carbon atom of said alkyl or alkenyl is optionally substituted in one or more position(s) with amino, halo, haloalkyl, thiocarbonyl, ester, thioester, alkoxy, alkenoxy, cyano, nitro, imino, alkylamino, aminoalkyl, sulfhydryl, thioalkyl, sulfonyl, or oxygen to form a carbonyl, or wherein any carbon atom of said alkyl or alkenyl is optionally replaced with 0, NH, NR 3 , S, SO, or S0 2 ; Z is a direct bond, straight or branched chain alkyl, or C 2 -C 6 straight or branched chain alkenyl , wherein any carbon atom of said alkyl or alkenyl is optionally substituted in one or more position(s) with amino, halo, haloalkyl, thiocarbonyl , _ ester, thioester, alkoxy, alkenoxy, cyano, nitro, imino, alkylamino, aminoalkyl, sulfhydryl, thioalkyl, sulfonyl, or oxygen to form a carbonyl, or wherein any carbon atom of said alkyl or alkenyl is optionally replaced with 0, NH, NR 3 , S, SO, or S0 2 ; C and D are independently hydrogen, Ar, straight or branched chain alkyl, or C 2 -C 6 straight or branched chain alkenyl; wherein said alkyl or alkenyl is optionally substituted with one or more substituent (s) independently selected from the group consisting of C 3 -C 8 cycloalkyl, C 5 -C 7 cycloalkenyl, hydroxy, carbonyl oxygen, and Ar; wherein said alkyl, alkenyl, cycloalkyl or cycloalkenyl is optionally substituted with alkyl, C 2 -C 6 alkenyl, hydroxy, amino, halo, haloalkyl, thiocarbonyl, ester, thioester, alkoxy, alkenoxy, cyano, nitro, imino, alkylamino, aminoalkyl, sulfhydryl, thioalkyl, or sulfonyl; wherein any carbon atom of said alkyl or alkenyl is optionally substituted in one or more position (s) with oxygen to form a carbonyl; or wherein any carbon atom of said alkyl or alkenyl is optionally replaced with O, NH, NR 3 , S, SO, or S0 2 ; Ar is an alicyclic or aromatic, mono-, bi- or tricyclic, carbo- or heterocyclic ring, wherein the ring is either unsubstituted or substituted with one or more substituent (s) ; wherein the individual ring size is 5-8 members; wherein said heterocyclic ring contains 1-6 heteroatom(s) independently selected from the group consisting of 0, N, and S; and wherein said aromatic or tertiary alkyl amine is optionally oxidized to a corresponding N-oxide; and A, B, Rl, R2, U, W, and X are as otherwise defined in claim 20 above.

Inventors: HAMILTON GREGORY S, STEINER JOSEPH P, HAMILTON, GREGORY, S., STEINER, JOSEPH, P.
Applicants: GUILFORD PHARM INC, GUILFORD PHARMACEUTICALS INC.
Application year: 1998
Main classification: A61K7
IPC codes: A61K8, A61K31, A61P17, A61P43, A61Q5, A61Q7