3-Deoxyaphidicolin and aphidicolin analogues as phytotoxins from Phoma betae.

In the previous papers,1'2) we reported the structural determination of betaenones, novel phytotoxins from Phoma betae Fr., which cause leaf spot disease on sugar beet.In continuing this series of studies, we noticed the presence of other root growth inhibitors of lettuce in the culture filtrate and mycelium of the fungus.From the active fractions, we isolated aphidicolin (1), a known antiviral and phytotoxic tetrahydroxy diterpene, and three new aphidicolin derivatives, 3-deoxyaphidicolin (2), aphidicolin-17-monoacetate(3) and aphidicolin-3,18-orthoacetate (4), which in-