Biotransformation of pregnenolone by Aspergillus glaucus

In this work, pregnenolone (2) was incubated with Aspergillus glaucus MRC 200914 in order to see how this fungus metabolise the substrate. The medium was prepared for the fungus in 1 L of distilled water. The medium was evenly disrubuted into 10 erlenmeyer flasks of 250 mL and sterilized by an autoclave. These flasks were inoculated by the fungus. The flasks were incubated for 3 days at 25 ºC on a shaker and the substrate in DMF was added aseptically into these flasks. All flasks were further incubated for 5 days under the same conditions. After incubation, the fungal mycellium was separated from the broth by filtration under the vacuum. The mycellium was rinsed with ethyl acetate and the broth was then extracted with ethyl acetate. The extracts were dried over sodium sulfate anhydrous and evaporated in vacuo to give a brown gum that was then chromatographed on silica gel 60. 3β,7α- dihydroxypregn-5-ene-20-one (14) and 3β,7α,11α-trihydroxypregn-5-ene-20-one (15) were obtained from the chromatography work. The structure determination of these compounds was carried out by comparing melting points, NMR and IR spectra of the starting material with those of metabolites.