Microbial metabolism of steviol and steviol-16α,17-epoxide

Incubation of steviol (2) with Bacillus megaterium, Mucor recurvatus, and Aspergillus niger afforded compounds 3-7, whereas incubation of steviol-16α,17-epoxide (8) with Mucor recurvatus afforded 5 and compounds 9-14. The structures of the compounds were fully elucidated using 1D and 2D NMR spectroscopic techniques, and HRFABMS, in addition, to describing the biological activities of the compounds 1-7.