RESUMO
Microbial steroid biotransformations have found a wide-reaching application for the production of more precious and functionalized compounds due to their high regio-and stereo selectivity. In this study, the possibility of using filamentous fungi Aspergillus brasiliensiscells in the biotransformation of progesterone, a C-21 steroid hormone was studied for the first time. The fungal strain was inoculated into the transformation medium supplemented with progesterone as a substrate. Biotransformation of this steroid for 7 days afforded 3 different hydroxylated metabolites: 11α-hydroxy progesterone; 14α-hydroxyprogesteroneand21-hydroxyprogesterone. The metabolites were separated by thin layer chromatography. Structure determinations of the metabolites were performed by comparing NMR, MS and IR spectra of the starting compound with those of metabolites. These results may be of industrial importance because the metabolites can be used as precursor of some steroid drugs.
RESUMO
BACKGROUND: The biotransformation of steroids by fungal biocatalysts has been recognized for many years. There are numerous fungi of the genus Aspergillus which have been shown to transform different steroid substances. The possibility of using filamentous fungi Aspergillus brasiliensis cells in the biotransformation of androsta-1,4-diene-3,17-dione, was evaluated. METHODS: The fungal strain was inoculated into the transformation medium which supplemented with androstadienedione as a substrate and fermentation continued for 5 days. The metabolites were extracted and isolated by thin layer chromatography. The structures of these metabolites were elucidated using (1)H-NMR, broadband decoupled (13)C-NMR, EI Mass and IR spectroscopies. RESULTS: The fermentation yielded one reduced product: 17ß-hydroxyandrost-1,4-dien-3-one and two hydroxylated metabolites: 11α-hydroxyandrost-1,4-diene-3,17-dione and 12ß-hydroxyandrost-1,4-diene-3,17-dione. CONCLUSIONS: The results obtained in this study show that A. brasiliendsis could be considered as a biocatalyst for producing important derivatives from androstadienedione.