Biosynthetic study of betaenone B: origin of the oxygen atoms and accumulation of a deoxygenated intermediate using P-450 inhibitor

Abstract

The biosynthetic origin of oxygen atoms in betaenone B (1) was established by feeding experiment using [1-¹³C, ¹⁸O₂] acetate and by cytochrome P-450 inhibitor treatment of Phoma betae; incorporation patterns and accumulation of the plausible intermediate enabled us to propose a biosynthetic pathway for (1) involving an intramolecular Diels–Alder reaction at a late stage.