Biotransformation of 5-en-3β-ol steroids by <i>Mucor circinelloides lusitanicus</i>

In this work, we report the mode of biotransformation of 5-en-3β-ol steroids using <i>Mucor circinelloides lusitanicus</i> for the first time. Here, we selected seven 5-en-3β-ol steroids as substrates. The main characteristic of the fungus was to introduce a 7α-hydroxyl group into substrates <b>1</b>--<b>5</b>. With substrate <b>2</b>, 3β, 7α, 11α-trihydroxypregna-5-en-20-one (<b>2b</b>) was obtained as the final product in good yield (46.4%). All the metabolites were determined by infrared spectra, high-resolution mass spectrometry, proton nuclear magnetic resonance, and carbon-13 nuclear magnetic resonance.