Biotransformation of the fungistatic sesquiterpenoid isoprobotryan-9α-ol by Botrytis cinerea

The antifungal activity of isoprobotryan-9α-ol (1) against the plant pathogen Botrytis cinerea has been determined. The biotransformation of this fungistatic sesquiterpenoid by B. cinerea gave the 12-, 14- and 15-hydroxyderivatives (2–4) as the major metabolites. The diminishing of the effect with time suggests that a mechanism of detoxification is present.