RESUMEN
The current state of knowledge regarding phytosterols biotransformation to produce the steroid intermediate 4-androstene-3,17-dione (AD) shows different technologies. However, the initial concentration of phytosterols in batch cultures is limited due to its low solubility in aqueous media, causing serious difficulties for scaling up because of the low mass transfer. In this chapter, we describe a fermentation method of a phytosterol microdispersion with Mycobacterium sp. B3805 in the context of an integral technology for AD production. The microdispersion generation is based on a patent application that claims the production of an aqueous phytosterol microdispersion with an average size particle of 370 nm, and high stability and solubility in water at high phytosterols concentrations (Harting et al., 2012/US0046254). Our results indicate that up to 20 g/L phytosterols can be biotransformed with this technology allowing a good dispersion and stability of reactants in the fermentation broth.
Asunto(s)
Androstenodiona/síntesis química , Ingeniería Metabólica/métodos , Mycobacterium/metabolismo , Fitosteroles/química , Androstenodiona/química , Biotransformación , Fermentación , Mycobacterium/genética , Agua/químicaRESUMEN
The aim of this study was to determine the capacity of some progesterone derivatives, to inhibit the conversion of labeled androstenedione ([(3)H] 4-dione) to [(3)H]dihydrotestosterone ([(3)H]DHT) in prostate nuclear membrane fractions, where the 5α-reductase activity is present. The enzyme 5α-reductase catalyzes the 5α-reduction of 4-dione whereas the 17ß-hydroxysteroid dehydrogenase catalyzes the transformation of 4-dione to testosterone or 5α-dione to dihydrotestosterone (DHT). Moreover, we also investigated the role of unlabeled 5α-dione in these pathways. In order to determine the inhibitory effect of different concentrations of the progesterone derivatives in the conversion of [(3)H] 4-dione to [(3)H]DHT, homogenates of human prostate were incubated with [(3)H] 4-dione, NADPH and increasing concentrations of non-labeled 5α-dione. The incubating mixture was extracted and purified using thin layer chromatography. The fraction of the chromatogram corresponding to the standard of DHT was separated and the radioactivity determined. The results showed that the presence of [(3)H] 4-dione plus unlabelled 5α-dione produced similar levels of DHT as compared to [(3)H] 4-dione. On the other hand, the results indicated that 17α-hydroxypregn-4-ene-3,20-dione 5 and 4-bromo-17α-hydroxypregn-4-ene-3,20-dione 7b, were the most potent steroids to inhibit the conversion of [(3)H] 4-dione to [(3)H]DHT, showing IC(50) values of 2 and 1.6 nM, respectively.
Asunto(s)
Inhibidores de 5-alfa-Reductasa/química , Inhibidores de 5-alfa-Reductasa/farmacología , Androstenodiona/química , Inhibidores Enzimáticos/química , Inhibidores Enzimáticos/farmacología , Adulto , Androstenodiona/antagonistas & inhibidores , Androstenodiona/metabolismo , Activación Enzimática/efectos de los fármacos , Humanos , Concentración 50 Inhibidora , Masculino , Estructura Molecular , Membrana Nuclear/enzimología , Próstata/metabolismoRESUMEN
The aim of this study was to synthesize three different D-homoandrostadiene derivatives (2-4) and study their biological activity. We carried out in vivo and in vitro experiments using female cycling mice, which were synchronized for estrus with luteinizing hormone-releasing hormone (LHRH) and injected with the steroidal compounds. It was also determined the binding of these compounds to the progesterone receptors (PR). Since these steroids have a new D-homoandrostandienone skeleton in their molecular structure, it was of interest also to study their binding to the androgen receptors (AR). After LHRH treatment, the mice of the control group showed the presence of 14+/-4 corpus lutea in the ovary whereas the animals treated with steroids 2-4, with RBAs of 100%, exhibited 11+/-7, 12+/-2, and 10+/-4 respectively. As a result of this study, it is evident that these steroids did not inhibit the ovulation in these animals. The uterus of the control group, showed the typical progestational activity with an enlarged endometrial thickness with a secretory activity. However, the endometrium of the mice treated with steroids 2-4 did not show an enlargement of the endometrium and no secretory activity could be detected. This fact indicates that compounds 2-4 had antagonistic activity in this tissue. The overall data show that steroids 2-4 are antagonists of the PR. However, they do not bind to the AR. These results also demonstrate that 2-4 have an antiprogestational activity in vivo, but do not decrease the number of corpus lutea in the ovary of mice treated with LHRH.
Asunto(s)
Androstadienos/química , Androstadienos/farmacología , Receptores de Progesterona/antagonistas & inhibidores , Antagonistas de Receptores Androgénicos , Androstadienos/metabolismo , Androstenodiona/análogos & derivados , Androstenodiona/química , Androstenodiona/farmacología , Animales , Unión Competitiva , Cuerpo Lúteo/efectos de los fármacos , Cuerpo Lúteo/metabolismo , Endometrio/efectos de los fármacos , Endometrio/metabolismo , Femenino , Hormona Liberadora de Gonadotropina/farmacología , Homoesteroides/química , Homoesteroides/farmacología , Antagonistas de Hormonas/química , Antagonistas de Hormonas/metabolismo , Antagonistas de Hormonas/farmacología , Masculino , Ratones , Mifepristona/química , Mifepristona/metabolismo , Mifepristona/farmacología , Estructura Molecular , Ovario/efectos de los fármacos , Ovario/metabolismo , Fenilacetatos/química , Progesterona/química , Progesterona/metabolismo , Progesterona/farmacología , Conejos , Ratas , Receptores Androgénicos/metabolismo , Receptores de Progesterona/metabolismo , Relación Estructura-Actividad , Útero/efectos de los fármacos , Útero/metabolismoRESUMEN
In this work, phytosterol-biotransforming strains were selected from Mycobacterium sp., using a high concentration of beta-sitosterol. The selection was made by culturing the strains in a medium enriched with 14 g beta-sitosterol/l as the unique source of carbon. During 2 months, the bacterial cultures were transferred successively. The extraction of the biotransformation products was made with methanol and ethyl acetate. The qualitative and quantitative analysis was made by means of thin-layer chromatography, gas-liquid chromatography (GLC) and GLC-mass spectrometry. Under these conditions, it was observed that after seven transfers, the strains MYcobacterium sp. MB-3683 and the Mycobacterium fortuitum B-11045 increased their biotransformation capacity from 20% to 64% and from 34% to 55%, respectively. The products in the highest proportion identified for each trial were androstenedione and androstadienedione. The results suggest that the high substrate concentration could be a selective mechanism to obtain strains more efficient in the biotransformation of beta-sitosterol into steroidal bases.