Eugenio Flores

Steroid 5α-Reductase Inhibitors

The objective of this study is to synthesize new steroidal compounds based on the progesterone skeleton with a high inhibitory activity for the enzyme 5α-reductase. Presently similar compounds are being used for the treatment of androgen dependent diseases such as: hirsutism, androgenic alopecia, bening prostatic hyperplasia and prostate cancer. Dihydrotestosterone 2 (Fig. (1)), a 55α-reduced metabolite of testosterone 1 has been implicated as a causative factor in the progression of these diseases, largely through the clinical evaluation of males who are genetically deficient of steroid 55α-reductase enzyme. As a result of this study, the inhibition of this enzyme has become a pharmacological strategy for the design and synthesis of new antiandrogenic drugs. The advent of finasteride 8 (Fig. (4)) a 55α-reductase inhibitor has grately alleviated the symptoms associated with benign prostatic hyperplasia. In our laboratory we recently synthesized several new 165β-methyl-pregnadiene-3,20-diones derivatives 27 (Fig.(6)), 38-42 (Fig. (11)), 16β-phenyl-pregnadiene-3,17a-dione derivatives 32-33 (Fig. (7)), 16β-phenylpregnatriene- 3,17a-diones, 30, 31 (Fig. (7)) and 16β-methyl-pregnatriene-3,20-diones 43-46 (Fig. (11)). These compounds were evaluated as 5α-reductase inhibitors in the following biological models: Penicillium crustosum broths, the flank organs of gonadectomized male hamsters, the incorporation of radiolabeled sodium acetate into lipids, the effect of the new steroids on the reduction of the weight of the seminal vesicles and on the in vitro metabolism of [3H]T to [3H]DHT in seminal vesicles homogenates of gonadectomized male hamsters. All trienones 30, 31, and 43-46 in all biological models showed consistently a higher 5α-reductase inhibitory activity than the corresponding dienones 27, 32, 33 and 38-42. We believe that with these compounds the 5α-reductase enzyme is inactivated by an irreversible Michael type addition of the nucleophilic portion of the enzyme to the conjugated double bond of the steroid. The trienones having a more coplanar structure react faster with the enzyme and thus show a higher inhibitory activity.

Effect of a novel steroid (PM-9) on the inhibition of 5α-reductase present in Penicillium crustosum broths

The conversion of testosterone (T) to 5alpha-dihydrotestosterone (DHT) has been demonstrated in Penicillium crustosum broth obtained from fermented pistachios, lemons and corn tortillas. Furthermore, the presence of 5alpha-reductase enzyme, which is responsible for this conversion, has been established by electrophoretical techniques in these cultures.5alpha-Reductase enzyme is also present in animal and human androgen-dependent tissues as well as in prostate and seminal vesicles. The increase of the conversion of T to DHT in prostate gland, has been related to some illnesses such as benign prostate hyperplasia and prostate cancer. Furthermore, treatment with 5alpha-reductase inhibitors such as finasteride reduces the prostate growth. These data have stimulated research for the synthesis of new molecules with antiandrogenic activity, whose biological effect needs to be demonstrated. The purpose of this study is to determine the inhibition pattern of 5alpha-reductase in P. crustosum by finasteride and the new steroidal compound PM-9. K(m) and V(max) values for T, were determined in the broths by Lineweaver-Burk plots using different testosterone concentrations. The inhibition pattern of finasteride and PM-9 was also determined by Lineweaver-Burk using different concentrations of T and inhibitors. Results show that finasteride and PM-9 inhibit 5alpha-reductase present in the broth in a competitive manner.

Recent advances in the chemistry and pharmacological activity of new steroidal antiandrogens and 5α-reductase inhibitors

The object of this paper is to summarize for the past two years the most recent development in the field of prostate cancer and 5 alpha-reductase inhibitors. In addition we are also including some results on the synthesis and pharmacological evaluation of new steroidal compounds developed in our laboratory. Most of the new steroidal derivatives are based on the progesterone skeleton and showed a high inhibitory activity for the enzyme 5 alpha-reductase. Presently, similar compounds are used for the treatment of androgen dependent diseases such as: hirsutism, androgenic alopecia, benign prostatic hyperplasia and prostate cancer. Dihydrotestosterone 2 (Fig. 1) a 5 alpha-reduced metabolite of testosterone 1 has been implicated as a causative factor for the progression of these diseases, largely through the clinical evaluation of males who are genetically deficient of the enzyme steroid 5 alpha-reductase. As a result of this study, the inhibition of this enzyme has become a pharmacological strategy for the design and synthesis of new antiandrogenic drugs. The advent of finasteride 7 (Fig. 3) a 5 alpha-reductase inhibitor has greatly alleviated the symptoms associated with benign prostatic hyperplasia. In our laboratory, we recently synthesized several new 16 beta-methylpregnadiene-3,20-diones: 40, 41 (Fig. 8), 16 beta-phenylpregnadiene-3,17a-dione derivatives 46 and 47 (Fig. 9) and 49 (C-4 bromoderivative) (Fig. 11), 52-56 (Fig. 13). The analogue pregnatriene derivatives were also prepared: 44, 45 (Fig. 9) 50, 51 (Fig. 11) and 57-60 (Fig. 13) These compounds were evaluated as 5 alpha-reductase inhibitors in the following biological models: Penicillium crustosum broths, the flank organs of gonadectomized male hamsters, the incorporation of radiolabeled sodium acetate into lipids, the effect of the new steroids on the reduction of the weight of the seminal vesicles and on the in vitro metabolism of [3H]T to [3H]DHT in seminal vesicles of homogenates of gonadectomized male hamsters. All trienones 44, 45, 50, 51 and 57-60 in all biological models showed consistently a higher 5 alpha-reductase inhibitory activity than the corresponding dienones: 40, 41, 46, 47, 49 and 52-56. We believe that with these compounds the 5 alpha-reductase enzyme is inactivated by an irreversible Michael type addition of the nucleophilic portion of the enzyme to the conjugated double bond of the steroid. The trienones having a more coplanar structure react faster with the enzyme thus showing a higher inhibitory activity.

Abietane and icetexane diterpenoids from Salvia ballotaeflora and Salvia axillaris

From the aereal parts of Salvia ballotaeflora three new icetexane diterpenoids were isolated besides anastomosine and conacytone. The structure of these compounds were established as 19-deoxyicetexone, 19-deoxyisoicetexone and 7,20-dihydroanastomosine by spectroscopic means. Cryptotanshinone was the sole diterpenoid isolated from both aerial parts and roots of S. axillaris.

Neo-clerodane diterpenoids from Scutellaria drummondii

Abstract Three new neo-clerodane diterpenoids, 6α-acetoxy-4α, 18-epoxy-2α-hydroxy-13-neocleroden-15,16-olide (2α-hydroxyajugarin V), 4α,18-epoxy-2α,6α-dihydroxy-13-neocleroden-15,16-olide (2α-hydroxy-deacetylajugarin V) and 2α,6α-dihydroxy-4(18),13-neoclerodadien-15,16-olide (scutedrummonin), have been isolated from the aerial parts of Scutellaria drummondii, in addition to the known flavone xanthomicrol. The structures of the new diterpenoids were established by chemical and spectroscopic means, including X-ray diffraction analysis for 2α-hydroxyajugarin V.

New Aromatic Esters of Progesterone as Antiandrogens

The in vivo and in vitro antiandrogenic activity of four new progesterone derivatives: 4-bromo-17α-(p-fluorobenzoyloxy)-4-pregnene-3,20-dione 1,4-bromo-17α-(p-chlorobenzoyloxy)-4-pregnene-3,20-dione 2, 4-bromo-17α-(p-bromobenzoyloxy)-4-pregnene-3,20-dione 3 and 4-bromo-17α-(p-toluoyloxy)-4-pregnene-3, 20-dione 4 was determined. These compounds were evaluated as antiandrogens on gonadectomized hamster prostate and reduced the weight of the prostate glands in gonadectomized hamsters treated with testosterone 5 (T) or dihydrotestosterone 6 (DHT) in a similar manner to that of commercially available finasteride, thus indicating a potent in vivo effect. The in vitro studies showed that steroids 1–4 have a weak inhibitory activity on 5α-reductase with IC50 values of: 280 (1), 2.6 (2), 1.6 (3) and 114 μM (4). The presence of Cl and Br atoms in the C-17 benzoyloxy group tends to increase the inhibitory potency of the compounds. The binding efficiency of the synthesized steroids 1–4 to the androgen receptor of the prostate gland is also evaluated. All compounds form a complex with the receptor and this explains the weight reduction of the seminal vesicles in the animals treated with DHT plus steroids 1–4.

Abietane and Icetexane Diterpenoids from Salvia Pubescens

Abstract The aerial parts of Salvia pubescens afforded, besides icetexone and methylconacytone, a new icetexane diterpenoid named 19(R)-acetoxy-19-deoxoicetexone. Its structure was elucidated by spectroscopic methods and chemical correlation with icetexone.