Bacillus stearothermophilus, a thermophilic bacterium isolated from Kuwaiti desert, when incubated with exogenous progesterone for 10 days at 65�C produced two monohydroxylated, two dihydroxy isomers of progesterone and a B-Seco compound. These metabolites were purified by TLC and HPLC followed by their identification through 1 H, 13 C NMR and other spectroscopic data. Microbial hydroxylation of 17β-estradiol resulted in the production of estrone. The effect of some inducers resulted in the production of two metabolites from 17β-estradiol, one of which was identified as 3,6β,17β-trihydroxyestra-1,3,5,14(10)-tetrene and the other metabolite remains unidentified. The transformation products were identified through their spectral data and comparison with reference compounds. Antioxidant activities of progesterone transformed mixture and purified metabolites of 17β-estradiol were studied by linoleic acid/β-carotene assay. An enhanced antioxidant activity for progesterone transformation products was observed when compared to progesterone. A comparison of antioxidant activity of progesterone and 17β-estradiol transformation products is reported.
