Biotransformation of spirolaxine by Absidia cuneospora and Trametes hirsuta: Formation of β-glycosyl and β-xylosyl derivatives

Incubation of spirolaxine 1a with the fungus Absidia cuneospora afforded 5β-glucosyl-spirolaxine 2b; the structure of the biotransformed product was deduced on the basis of MS, NMR data and chemical semi-synthesis. When using Trametes hirsuta as a bioagent 1a afforded 5β-xylosyl-spirolaxine 3a; the identification of the sugar moiety came from acidic hydrolysis of the new metabolite.