Biotransformation of drospirenone, a contraceptive drug, with Cunninghamella elegans

Fungal mediated biotransformation of melengestrol acetate, and T-cell proliferation inhibitory activity of biotransformed compounds

Glomerella fusaroide, and Rhizopus stolonifer were effectively able to transform the steroidal hormone melengestrol acetate (MGA) (1) into four (4) new metabolites, 17α-acetoxy-11α-hydroxy-6-methyl-16-methylenepregna-4,6-diene-3,20-dione (2), 17α-acetoxy-11α-hydroxy-6-methyl-16-methylenepregna-1,4,6-triene-3,20-dione (3), 17α-acetoxy-6,7α-epoxy-6β-methyl-16-methylenepregna-4,6-diene-3,20-dione (4), and 17α-acetoxy-11β,15β-dihydroxy-6-methyl-16-methylenepregna-4,6-diene-3,20-dione (5). All these compounds were structurally characterized by different spectroscopic techniques. The objective of the current study was to assess the anti-inflammatory potential of melengestrol acetate (1), and its metabolites 2-5. The metabolites and the substrate were assessed for their inhibitory effects on proliferation of T-cells in vitro. The substrate (IC₅₀ = 2.77 ± 0.08 µM) and its metabolites 2 (IC₅₀ = 2.78 ± 0.07 µM), 4 (IC₅₀ = 2.74 ± 0.1 µM), and 5 (IC₅₀ = < 2 µM) exhibited potent T- cell proliferation inhibitory activities, while compound 3 (IC₅₀ = 29.9 ± 0.09 µM) showed a moderate activity in comparison to the standard prednisolone (IC₅₀ = 9.73 ± 0.08 µM). All the metabolites were found to be non-toxic against 3T3 normal cell line. This study thus identifies some potent compounds active against T-cell proliferation. Their anti-inflammatory potential, therefore, deserves to be further investigated.

Seven new metabolites of drostanolone heptanoate by using Beauveria bassiana, and Macrophomina phaseolina cell suspension cultures

The present study reports the biotransformation of an anabolic-androgenic steroid (AAS) drostanolone heptanoate (1) by using two microbial cultures, Beauveria bassiana, and Macrophomina phaseolina. Fermentation of 1 with B. bassiana yielded five new transformed products 2–6, while with M. phaseolina it afforded two new 7–8, and two known 9–10 metabolites. The main sites of hydroxylation in the steroidal skeleton of 1 were at C-5, C-7, C-11, C-14, C-15, and C-20, hydrolysis of the ester moiety at C-17, and reduction of the carbonyl group at C-3. The structures of the transformed products were determined by using mass, NMR, and other spectroscopic techniques.

Incubation of drostanolone heptanoate (1) with B. bassiana and M. phaseolina afforded seven new and two known metabolites.The main sites of hydroxylation include C-5, C-7, C-11, C-14, C-15, and C-20, hydrolysis at C-17, and reduction at C-3 of 1.

Biotransformation of ruscogenins by Cunninghamella blakesleeana NRRL 1369 and neoruscogenin by endophytic fungus Neosartorya hiratsukae

Biotransformation of steroidal ruscogenins (neoruscogenin and ruscogenin) was carried out with Cunninghamella blakesleeana NRRL 1369 and endophytic fungus Neosartorya hiratsukae yielding mainly P450 monooxygenase products together with a glycosylated compound. Fermentation of ruscogenins (75:25, neoruscogenin-ruscogenin mixture) with C. blakesleeana yielded 8 previously undescribed hydroxylated compounds. Furthermore, microbial transformation of neoruscogenin by endophytic fungus N. hiratsukae afforded three previously undescribed neoruscogenin derivatives. While hydroxylation at C-7, C-12, C-14, C-21 with further oxidation at C-1 and C-7 were observed with C. blakesleeana, N. hiratsukae biotransformation provided C-7 and C-12 hydroxylated compounds along with C-12 oxidized and C-1(O) glycosylated derivatives. The structures of the metabolites were elucidated by 1-D (¹H, ¹³C and DEPT135) and 2-D NMR (COSY, HMBC, HMQC, NOESY, ROESY) as well as HR-MS analyses.

Microbial transformation of pseudoprotodioscin by Gibberella fujikuroi

Three new (6, 9, and 12) and nine known steroidal saponins were obtained from the fermentation broth of pseudoprotodioscin (PPD) incubated with a fungus Gibberella fujikuroi CGMCC 3.4663. Structures of the metabolites were elucidated by 1-D (¹H, ¹³C), 2-D (HMBC, HSQC, NOESY) NMR, and HR-MS analyses. The biotransformation pathway of pseudoprotodioscin by Gibberella fujikuroi CGMCC 3.4663 was proposed. Compounds 1-11 were tested in vitro for their cytotoxic activities against two human cancer cell lines (HepG2 and Hela). Compounds 1, 6, 9, and 10 exhibited cytotoxic activity against HepG2 cells. Compound 10 exhibited cytotoxicity to Hela cells.