ACETOXYDEHYDROAUSTIN, A NEW BIOACTIVE COMPOUND, AND RELATED COMPOUND NEOAUSTIN FROM PENICILLIUM SP MG-11

Compounds from a soil isolate of Penicillium sp. MG-11 showed remarkab le convulsive activity against silkworms. Activity-based fractionation of an acetone extract of the fermentation products resulted in the is olation of four compounds. One was identified as verruculogen, which w as an active principle. Another compound, acetoxydehydroaustin, was ne w and was structurally characterized by spectral data and a single-cry stal X-ray analysis. The two other compounds were identified as dehydr oaustin and austin on the basis of the spectral data. Although the lat ter three compounds were not active themselves, they enhanced the conv ulsive activity of verruculogen in a silkworm bioassay. Three addition al compounds with no identifiable activity were also isolated. Two of them were identified as austinol and dehydroaustinol, and the third wa s determined to be a new related compound named neoaustin by an X-ray analysis of crystals.