14α-Hydroxylation of Androst-4-en-3, 17-dione by the Whole Cells of Cyanobacterium Nostoc piscinale

Oxidative potential of two Brazilian endophytic fungi from Handroanthus impetiginosus towards progesterone

Biotransformation has been successfully employed to conduct uncommon reactions, which would hardly be carried out by chemical synthesis. A wide diversity of compounds may be metabolized by fungi, leading to chemical derivatives through selective reactions that work under ecofriendly conditions. Endophytic fungi live inside vegetal tissues without causing damage to the host plant, making available unique enzymes for interesting chemical derivatization. Biotransformation of steroids by endophytic fungi may provide new derivatives as these microorganisms came from uncommon and underexplored habitats. In this study, endophytic strains isolated from Handroanthus impetiginosus leaves were assayed for biotransformation of progesterone, and its derivatives were identified through GC-EI-MS analysis. The endophyte Talaromyces sp. H4 was capable of transforming the steroidal nucleus selectively into four products through selective ene-reduction of the C4-C5 double bond and C-17 oxidation. The best conversion rate of progesterone (>90 %) was reached with Penicillium citrinum H7 endophytic strain that transformed the substrate into one derivative. The results highlight endophytic fungi's potential to obtain new and interesting steroidal derivatizations.

Biotransformation of androst-4-ene-3,17-dione and nandrolone decanoate by genera of Aspergillus and Fusarium

The ability of five fungal species belonging to two genera of Aspergillus and Fusarium has been examined in the microbial transformation of androst-4-ene-3, 17-dione (AD). Furthermore, the biotransformation of nandrolone decanoate (2) by F. fujikuroi has been studied. AD (1) was converted by cultures of Aspergillus sp. PTCC 5266 to form 11α-hydroxy-AD (3) as the only product, with a yield of 86% in 3 days. Moreover, two hydroxylated metabolites 11α-hydroxy-AD (3, 65%) and 7β-hydroxy-AD (4; 18%) were isolated in biotransformation of AD by A. nidulans. On the other hand, it was metabolized by F. oxysporum to produce 14α-hydroxy-AD (5; 38%) and testosterone (6; 12%). Microbial transformation of AD by F. solani led to the production of 11α-hydroxy-AD (3; 54%) and testosterone (6; 14%). AD was reduced at the 17-position by F. fujikuroi to produce testosterone in the yield of 42%. Finally, nandrolone decanoate was transformed by F. fujikuroi via hydrolysis and oxidation at the 17-position to produce two metabolites namely 17β-hydroxyestr-4-en-3-one (7, 25.4%) and estr-4-en-3,17-dione (8, 33%), respectively. The all metabolites were purified and subsequently identified based on their spectra data analysis and comparing them to the literature data.

Biotransformation of testosterone and testosterone heptanoate by four filamentous fungi

The microbial transformations of testosterone and testosterone heptanoate by four fungi: Absidia griseolla var. igachii PTCC 5260, Acremonium chrysogenu PTCC 5271, Fusarium fujikuroi PTCC 5144, and Fusarium solani complex PTCC 5285 were investigated for the first time. Incubation of testosterone heptanoate with F. fujikuroi and F. solani yielded three metabolites, which were isolated and characterized as testosterone, androst-4-ene-3,17-dione, and 6β-hydroxy testosterone. 6β-Hydroxy testosterone was the major metabolite obtained from testosterone heptanoate biotransformation by two fungal species. A. griseolla and A. chrysogenu produced 14α-hydroxy testosterone as major metabolite, together with testosterone and 6β-hydroxy testosterone in lower yields. The biotransformation of testosterone by F. fujikuroi and A. griseolla was also investigated in order to examine the influence of the ester group on the course of transformation. Androst-4-ene-3,17-dione was only identified in the biotransformation of testosterone by F. fujikuroi. The same product was observed in incubation of testosterone by A. griseolla, together with 14α-hydroxy testosterone in very low yield. Furthermore, time course study was also carried out in order to examine the formation of metabolites as a function of time, which was determined by HPLC. The structures of compounds were determined by their comprehensive spectroscopic analysis and comparison with literature data.