Molecular interactions of new pregnenedione derivatives

The in vitro inhibitory activity of five new progesterone derivatives: 17alpha-hydroxy-16beta-methylpregna-1,4,6-triene-3,20-dione 1; 16beta-methyl-17alpha-toluoyloxypregna-1,4,6-triene-3,20-dione 2; 17alpha-hydroxy-6-methylenepregn-4-ene-3,20-dione 3; 6-methylene-17alpha-toluoyloxypregn-4ene-3,20-dione 4 and 17alpha-(p-bromobenzoyloxy)-6-methylenepregn-4-ene-3,20-dione 5 was determined. These compounds were evaluated as 5alpha-reductase inhibitors as well as antagonists for the androgen receptor. Compounds 1, 2, 3, 4 and 5 showed the following inhibitory activity for the 5alpha-reductase enzyme with IC(50) values of: 1 (1.65 microM), 2 (10 microM), 3 (19 nM), 4 (100 nM) and 5 (100 nM). The results of this study also showed the effect of increasing concentrations of the novel steroids upon [(3)H]dihydrotestosterone binding to androgen receptors from male hamster prostate. The K(i) values for compounds 1, 2, 3, 4, 5 and dihydrotestosterone showed the following order of affinity for the androgen receptor: 4>5>dihydrotestosterone>2>3>1. The overall data indicated that all synthesized compounds 1, 2, 3, 4 and 5 are inhibitors of the 5alpha-reductase enzyme present in the hamster prostate. In addition compounds 1, 2, 3, 4 and 5 also presented an affinity for the androgen receptor.     

5 Alpha-reductase inhibitory and antiandrogenic activities of novel steroids in hamster seminal vesicles

The pharmacological activity of several 16-bromosubstituted trienediones 4 and 5, 16-methyl substituted dienediones 6 and 7 and the 16-methyl substituted trienedione 8 was determined on gonadectomized hamster seminal vesicles by measuring the in vitro conversion of testosterone (T) to dihydrotestosterone (DHT) as 5alpha-reductase inhibitors and also the ability of these steroids to bind to the androgen receptor. Steroids 6 and 7 when injected together with T decreased the weight of the seminal vesicles thus showing an antiandrogenic effect. Compounds 5 and 6 reduced substantially the conversion of T to DHT and therefore can be considered good inhibitors for the enzyme 5alpha-reductase; however both steroids failed to form a complex with the androgen receptor. On the other hand compound 7 which showed a very small inhibitory activity for the enzyme 5alpha-reductase, exhibited a very high affinity for the androgen receptor and thus can be considered an effective antiandrogen. This compound also reduced substantially the weight of the seminal vesicles. Steroids 4 and 8 did not reduce the weight of the seminal vesicles and exhibited a low affinity for the androgen receptor; 8 showed a weak 5alpha-reductase inhibitory activity, whereas 4 exhibited a weak androgenic effect.     

Antiandrogenic effect of 16-substituted, non-substituted and D-homopregnane derivatives

The pharmacological activities of 12 pregnane derivatives (4-15) were determined on gonadectomized male hamster flank organs and seminal vesicles as antiandrogens and as 5alpha-reductase inhibitors. The results from this study indicate that subcutaneous injection of testosterone for 3 d increased the diameter of the pigmented spot in the flank organs, whereas finasteride when injected with testosterone decreased the size of the spot significantly when steroids 4-15 were injected together with testosterone, the diameter of the flank organs of gonadectomized male hamsters, decreased significantly (p<0.005) compared to testosterone. Compound 11 was the most active steroid and reduced the diameter of the pigmented spot more than the other synthesized steroids or finasteride. Subcutaneous injections of testosterone to gonadectomized animals restore the seminal vesicle size lost upon castration. Injection of testosterone plus finasteride decreased significantly the weight of these glands (p<0.005). Steroids 5-15 when injected with testosterone decreased the weight of the seminal vesicles compared to testosterone. Finasteride is a good inhibitor of the conversion of testosterone to dihydrotestosterone (DHT) (low formation of DHT) measured as pmole of DHT/g of protein/h. Steroids 6-15 inhibited the conversion of testosterone to DHT as compared to testosterone however finasteride and 10 appeared to be the most effective compounds. Castration increases the protein content of the seminal vesicles (control) expressed as microg/mg of tissues. Testosterone tends to decrease it significantly, as did compounds 4, 5, 7, 9, and 15. We demonstrated that DHT as well as cyproterone acetate and steroids 5, 6, 8, 9, 11, and 14 at increasing non radioactive steroid concentration, inhibited the binding of [3H]DHT to cytosolic androgen receptor (AR), as indicated by its Ki values. However, 4, 7, 10, 12, and 13 did not have any inhibitory effect.     

New progesterone esters as 5alpha-reductase inhibitors

The pharmacological activity of four new progesterone derivatives: 4-bromo-17alpha-(p-fluorobenzoyloxy)-4-pregnene-3,20-dione (7), 4-bromo-17alpha-(p-bromobenzoyloxy)-4-pregnene-3,20-dione (8), 4-bromo-17alpha-(p-chlorobenzoyloxy)-pregnene-3,20-dione (9) and 4-bromo-17alpha-(p-toluoyloxy)-4-pregnene-3,20-dione (10) was determined. These compounds were evaluated as 5alpha-reductase inhibitors on gonadectomized hamster seminal vesicles and flank organs. The pharmacological data of this study indicate that compounds 7 and 9 having at C-17 p-fluorobenzoyloxy and p-chlorobenzoyloxy ester functions respectively showed the highest antiandrogenic effect as measured by the reduction of the weight of the seminal vesicles. In the flank organ model, the same compounds 7 and 9 exhibited a smaller diameter, 1.8 and 1.0 mm, respectively, than the commercially available finasteride 3 (2.3 mm), thus indicating a higher inhibitory effect on 5alpha-reductase enzyme. Steroid 7 showed a higher inhibitory activity on the conversion of T to DHT (Fig. 3) than the presently used finasteride, thus indicating a higher antiandrogenic effect. The nonsubstituted benzoyloxy ester (compound 15) showed a lower antiandrogenic activity as measured in the seminal vesicles model than the p-substituted benzoyloxy compounds.     

Evaluation of new pregnane derivatives as 5alpha-reductase inhibitor

The objective of this study was to synthesize several new pregnane derivatives and evaluate them as antiandrogens. From the commercially available 16-dehydropregnenolone acetate (7), two new steroidal compounds were synthesized: 17alpha-hydroxy-17beta-methyl-16beta-phenyl-D-homoandrosta-1,4,6-triene-3,20-dione (18) and 17alpha-acetoxy-17beta-methyl-16beta-phenyl-D-homoandrosta-1,4,6-triene-3,20-dione (19). The 5alpha-reductase inhibitory effect of the new compounds 18 and 19 together with the previously synthesized intermediates 7, 8, 13, 16, and 17 was determined in three different models: gonadectomized hamster flank organs diameter size, incorporation of [1,2-(14)C]sodium acetate into lipids in flank organs and conversion of [3H]testosterone (T) to [3H]dihydrotestosterone (DHT) by Penicillium crustosum. The evaluation of these steroids was carried out with three different controls: one group was treated with vehicle, the second with T and the third group with T plus finasteride. The pharmacological results from this work demonstrated that T significantly increases the diameter of the pigmented spot on the flank organs (p<0.05) as well as the incorporation of labeled sodium acetate into lipids in gonadectomized hamster flank organs (from 0.125 to 0.255 nmol per gland). In this study we also observed that broth of Penicillium crustosum converted [3H]T to [3H]DHT in a manner comparable to that of the flank organs. All experiments indicated that finasteride as well as steroids 7, 8, 13, 16-19 reduced significantly the conversion of T to DHT in P. crustosum. These compounds also decrease the size of the pigmented spot in the flank organs as well as reducing the incorporation of radiolabeled sodium acetate into lipids; T and the control sample (treated with vehicle only) were used for comparison. Apparently the presence of the 4,6-diene-3,20-dione moiety and also the C-17 ester group produce a higher inhibitory effect on the parameters used. PPThe data from this study indicated also that the three models used for the pharmacological evaluation exhibited comparable results.     

Endodesmiadiol, a friedelane triterpenoid, and other antiplasmodial compounds from Endodesmia calophylloides

From the ethyl acetate extract of the stem bark of Endodesmia calophylloides (Guttiferae), a novel friedelane triterpenoid named endodesmiadiol (1), as well as the known compounds friedelin (2), canophyllol (3), canophyllal (4), cerin (5), morelloflavone (6), volkensiflavone (7), 8-deoxygartanin (8), 3 beta-acetoxyoleanolic acid (9) and 1,8-dihydroxy-3-isoprenyloxy-6-methylxanthone (10) have been isolated. The structures of these compounds were established by spectroscopic analysis, and the relative configuration of endodesmiadiol (1) was confirmed by X-ray diffraction. The antiplasmodial activity of the isolated compounds was evaluated against the W2 strain of Plasmodium falciparum which is resistant to chloroquine and other antimalarial drugs. All the compounds were found to be active with IC50 values ranging from 7.2 to 23.6 microM. The IC50 of endodesmiadiol was found to be 11.8 microM.     

A new labdane diterpene from the flowers of Solidago canadensis

A new labdane diterpene, 9alpha,16xi-dihydroxy-6-oxo-7,13-labdadien-15,16-olide (solicanolide, 1) and six known compounds identified as quercetin (2), 3-O-caffeoylquinic acid (3, neochlorogenic acid), 5-O-caffeoylquinic acid (4, chlorogenic acid), 4,5-di-O-caffeoylquinic acid (5), 3,5-di-O-caffeoylquinic acid (6) and 3,4-di-O-caffeoylquinic acid (7) were isolated from the flowers of Solidago canadensis. To our knowledge, compound 7 was isolated for the first time in S. canadensis. This work describes the isolation of compounds 1-7 and the structure elucidation of a new compound identified as compound 1. Solicanolide (1) showed cytotoxic activity against A549 (IC(50): 13+/-2 microM), DLD-1 (IC(50): 26+/-2 microM) and WS1 (IC(50): 17+/-1 microM) cell lines.     

A novel class of inhibitors for human steroid 5alpha-reductase: synthesis and biological evaluation of indole derivatives. II

In a search for novel nonsteroidal inhibitors of human prostatic 5alpha-reductase, we found a new series of indole derivatives that showed potent inhibitory activities for the human enzyme. Among them, 4-[(1-benzyl-1H-indol-5-yl)oxyl-3-chlorobenzoic acid (2d, YM-32906) showed more potent inhibitory activity than finasteride with an IC50 value of 0.44 nM. 3-Chloro-4-[[1-(4-phenoxybenzyl)-1H-indol-5-yl]oxy]benzoic acid (2m) showed inhibitory activities for both human and rat prostatic 5alpha-reductase with IC50 values of 2.1 and 73 nM, respectively. The synthesis and structure-activity relationships of these indole derivatives are presented.     

Phenolic constituents from the heartwood of Artocapus altilis and their tyrosinase inhibitory activity

From the MeOH extract of the heartwood of Artocapus altilis, thirteen phenolic compounds have been isolated, namely curcumin (1), desmethoxycurcumin (2), retrodihydrochalcone (3), apigenin (4), tangeretin (5), nobiletin (6), O-methyldehydrodieugenol (7), dehydrodieugenol (8), beta-hydroxypropiovanillone (9), p-coumaric acid (10), p-hydroxybenzaldehyde (11), vanillin (12), and vanillic acid (13). This is the first report on the presence of these compounds in the heartwood of A. altilis. Compounds 1, 2, and 10 showed more potent tyrosinase inhibitory activities, with IC50 values ranging from 2.3 to 42.0 microM, than the positive control kojic acid (IC50, 44.6 microM). The most active compound, p-coumaric acid (10) (IC50, 2.3 microM), was 22 times more active in tyrosinase inhibitory activity than kojic acid.     

Synthesis and pharmacological evaluation of new progesterone esters as 5alpha-reductase inhibitors

In this study we report the synthesis and pharmacological evaluation of four new progesterone derivatives; 17alpha-hydroxy-16beta-methylpregna-4,6-diene-3,20-dione 12, 17alpha-cyclopropylcarbonyloxy-16beta-methylpregna-4,6-diene-3,20-dione 13, 17alpha-cyclobutylcarbonyloxy-16beta-methylpregna-4,6-diene-3,20-dione 14, 17alpha-acetoxy-16beta-methylpregna-4,6-diene-3,20-dione 15 and the pregnatriene compound 17alpha-cyclobutylcarbonyloxy-16beta-methylpregna-1,4,6-triene-3,20-dione 16. The pharmacological effect of these compounds was determined in vivo as well as in vitro. The evaluation in vivo was carried out on gonadectomized male hamsters that were injected subcutaneously daily with testosterone (T) and/or finasteride, or with the novel compounds. At the end of the treatments the animals were sacrificed and the prostates were weighed. It was observed that when testosterone (T) and finasteride or compounds 12-16 were injected together, the weight of the prostate decreased significantly as compared to that of the testosterone-treated animals. The 5alpha-reductase inhibitory activity was evaluated in vitro using human prostate homogenates. These experiments showed the following IC50 values: compound 12 (alcohol at C-17) 1.2 x 10(-6) M, 13 (cyclopropyl substituent at C-17) 7.9 x 10(-10) M, 14 (cyclobutyl substituent) 3.2 x 10(-8) M, 15 (acetoxy substituent) 6.3 x 10(-11) M and 16 (cyclobutyl substituent) 3.9 x 10(-6) M. It is evident from these data that when the size of the substituent at C-17 is decreased, the 5alpha-reductase inhibitory activity increases. Apparently, in this biological model, the 5alpha-reductase inhibitory activity depends upon the steric effect of the substituent at C-17. However, the free alcohol 12 showed much lower 5alpha-reductase inhibitory activity.     

Probing sponge-derived terpenoids for human 15-lipoxygenase inhibitors

A human 15-lipoxygenase (15-HLO) assay has been employed to discover new marine-sponge-derived bioactive compounds. Extracts from two different sponges, Jaspis splendens (order Choristida, family Jaspidae) and Suberea sp. (order Verongida, family Aplysinellidae), exhibited potent IC(50) values of 0.4 and 0.1 microg/mL, respectively. Both are sources of terpenoids, and the former is a known source of (+)-jasplakinolide (7), which is inactive as a 15-HLO inhibitor. The terpenoids included (+)-(5S,6S)-subersin (1, IC(50) > 100 microM), (-)-(5R,10R)-subersic acid (2, IC(50) = 15 microM), jaspaquinol (3, IC(50) = 0.3 microM), and (-)-jaspic acid (4, IC(50) = 1.4 microM). Structure elucidations and lipoxygenase activity studies of these compounds are reported.     

Antihepatitis B virus constituents of Solanum erianthum

Eleven compounds were isolated from the methanolic extract of the leaves of Solanum erianthum D. Don, including five alpha-linolenic acid analogs, alpha-linolenic acid (1), 13S-hydroxy-9(Z),11(E)-octadecadienoic acid (2), 9S-hydroxy-10(E),12(Z), 15(Z)-octadectrienoic acid (3), 9(Z),11(E)-octadecadienoic acid (4), and octadecanoic acid (5); two benzofuran-type lactones, loliolide (6) and dihydroactinidiolide (7); two steroidal alkaloids, solasonine (8) and solamargine (9); a flavonol glycoside, camelliaside C (10); and a flavone, 5-methoxy-(3,4"-dihydro-3",4"-diacetoxy)-2",2'-dimethylpyrano-(7,8:5",6")-flavone (11). Among these isolated compounds, 9 showed the most potent activity against HBsAg, with an IC50 of 1.57 microM, followed by 8 (IC50 is 5.89 microM). In the testing against HBeAg, 11 was the only active compound with an IC50 of 36.11 microM. Compound 9 also revealed strong inhibition of DNA replication towards HBV and its IC50 was 2.17 microM. However, alpha-linolenic acid (1) showed a prominent selected index (SI), both in anti-HBsAg and inhibition of DNA replication with SI values of 7.75 and 7.18, respectively. This is the first report that unsaturated fatty acid 1, steroidal alkaloid glycoside 9 and flavone 11, all showed excellent activity against HBV. These results provide lead candidates in the development of anti-HBV drugs from natural sources.     

Parallel approach for solution-phase synthesis of 2-quinoxalinol analogues and their inhibition of LPS-induced TNF-alpha release on mouse macrophages in vitro

A parallel solution-phase synthesis of 2-quinoxalinol analogues is described. The key step-simultaneous reductions of m-Ar(NO(2))(2) to m-Ar(NH(2))(2) was investigated extensively. We obtained preliminary pharmacological activity of those analogues for the inhibition of LPS-induced TNF-alpha release on mouse macrophage in vitro. Two compounds revealed inhibitory activity, with IC(50) values of 0.40 microM (7-amino-6-[(3-methoxypropyl)amino]-3-methyl-2-quinoxalinol) and 2.2 microM (7-amino-6-[(3-butoxypropyl)amino]-3-methyl-2-quinoxalinol), respectively.     

Isolation of onosmins A and B, lipoxygenase inhibitors from Onosma hispida

Onosmins A (1) and B (2), lipoxygenase inhibitors, have been isolated from Onosma hispida. Their structures were established as 2-[(4-methylbenzyl)amino]benzoic acid (1) and methyl 2-[(4-methylbenzyl)amino]benzoate (2) through spectroscopic studies, including 2D-NMR. The known compounds apigenin (3), 6,4'-dimethoxy-3,5,7-trihydroxyflavone (4), 6,7-dimethoxy-3,5,4'-trihydroxyflavone (5) and apigenin 7-O-beta-D-glucoside (6) are also reported for the first time from this species. Compounds (1) and (2) inhibited lipoxygenase (LOX, EC 1.13.11.12) enzyme in a concentration-dependent fashion with IC50 values of 24.0 and 36.2 microM, respectively. Lineweaver-Burk as well as Dixon plots and their secondary replots indicated that the nature of inhibition was purely a non-competitive type, with K(i) values 22.0 microM and 31.1, respectively.     

Chemical constituents of the new endophytic fungus Mycosphaerella sp. nov. and their anti-parasitic activity

Chemical investigation of a new endophytic fungus, Mycosphaerella sp. nov. strain F2140, associated with the foliage of the plant Psychotria horizontalis (Rubiaceae) in Panama, resulted in the isolation of cercosporin (1) and a new cercosporin analog (3) as the major components. The structures of minor compounds in the extract were elucidated by detailed spectroscopic analysis as 2-(2-butyl)-6-ethyl-3-hydroxy-6-methylcyclohex-2-ene-1,5-dione (4), 3-(2-butyl)-6-ethyl-5-hydroxy-2-methoxy-6-methyl-cyclohex-2-enone (5), and an isomer of 5 (6). To study the influence of the hydroxy groups on the anti-parasitic activity of cercosporin, compound 1 was acetylated to obtain derivative 2. The isolated compounds 1- 6 were tested in vitro to determine their anti-parasitic activity against the causal agents of malaria (Plasmodium falciparum), leishmaniasis (Leishmania donovani), and Chagas disease (Trypanosoma cruzi). Cytotoxicity and potential anticancer activity of these compounds were evaluated using mammalian Vero cells and MCF7 cancer cell lines, respectively. Compounds 1 and 2 displayed high potency against L. donovani (IC50 0.46 and 0.64 microM), T. cruzi (IC50 1.08 and 0.78 microM), P. falciparum (IC50 1.03 and 2.99 microM), and MCF7 cancer cell lines (IC50 4.68 and 3.56 microM). Compounds 3-6 were not active in these assays at a concentration of 10 microg/mL.     

Leishmanicidal and cholinesterase inhibiting activities of phenolic compounds from Allanblackia monticola and Symphonia globulifera

In a preliminary antiprotozoal screening of several Clusiaceae species, the methanolic extracts of Allanblackia monticola and Symphonia globulifera showed high in vitro leishmanicidal activity. Further bioguided phytochemical investigation led to the isolation of four benzophenones: guttiferone A (1), garcinol (2), cambogin (3) and guttiferone F (4), along with three xanthones: allanxanthone A (5), xanthone V1 (6) and globulixanthone C (7) as active constituents. Compounds 1 and 6 were isolated from S. globulifera leaves, while compounds 2-5 were obtained from A. monticola fruits. Guttiferone A (1) and F (4) showed particulary strong leishmanicidal activity in vitro, with IC50 values (0.2 microM and 0.16 microM, respectively) comparable to that of the reference compound, miltefosine (0.46 microM). Although the leishmanicidal activity is promising, the cytotoxicity profile of these compounds prevent at this state further in vivo biological evaluation. In addition, all the isolated compounds were tested in vitro for their anticholinesterase properties. The four benzophenones showed potent anticholinesterase properties towards acetylcholinesterase (AChE) and butylcholinesterase (AChE). For AChE, the IC50 value (0.66 microM) of garcinol (2) was almost equal to that of the reference compound galanthamine (0.50 microM). Furthermore, guttiferone A (1) and guttiferone F (4) (IC50 = 2.77 and 3.50 microM, respectively) were more active than galanthamine (IC50 = 8.5) against BChE.