Fungal transformation of androsta-1,4-diene-3, 17-dione by Aspergillus brasiliensis

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 1H-NMR, broadband decoupled 13C-NMR, EI Mass and IR spectroscopies. Results: The fermentation yielded one reduced product: 17β-hydroxyandrost-1,4-dien-3-one and two hydroxylated metabolites: 11α-hydroxyandrost-1,4-diene-3,17-dione and 12β-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.