The role of botrydienediol in the biodegradation of the sesquiterpenoid phytotoxin botrydial by Botrytis cinerea

The biotransformation of botrydienediol (6) labelled with deuterium on carbons C-10 and C-15 has been studied. This has led to modification of some previous assumptions about the biodegradative route of botrydial. The 10-²H,15-²H]-botry-1(9)-4-diendiol (12) was transformed into dehydrobotrydienediol derivatives 13-15 but it was not incorporated into secobotryane skeleton (7). In addition, three new sesquiterpenoids have been isolated, which shed further light on the secondary metabolites of Botrytis cinerea. From the point of view of persistence of these toxins in the food chain, the easy biotransformation and different biodegradative routes of botrydial (1), seem to indicate that the toxin may not persist in the plant for a long time as it will be metabolized by the fungi and the plant.