Rearrangement and oxidation of β-amyrin promoted by growing cells of Lecanicillium muscarinium

Abstract

Microbial transformation of β-amyrin by growing cells of the fungus Lecanicillium muscarinium (former Cephalosporium aphidicola) was successfully accomplished after 15 days of incubation with orbital shaking at 120 rpm. Two products purified by column chromatography were identified by ¹H and ¹³C mono- and bi-dimensional nuclear magnetic resonance as 3β-hydroxy-olean-12-en-11-one and 11α,12α-oxidotaraxerol; these later formed new compounds formed by an interesting oxidative rearrangement of the starting material, probably via an initial hydroxylation at C-11.

Keywords:

• microbial transformation
• β-amyrin
• Lecanicillium muscarinium
• rearrangement

Acknowledgements

The authors thank CNPq for scholarships (307846/2006-7 and 141551/2007-0) and FAPEMIG (APQ-6629-5.02/07) and IFS (F/3564-2) for financial help.