AFLAVININES AND OTHER ANTIINSECTAN METABOLITES FROM THE ASCOSTROMATA OF EUPENICILLIUM-CRUSTACEUM AND RELATED SPECIES

This report describes the distribution of antiinsectan metabolites pre sent in sclerotioid ascostromata produced by representative strains of Eupenicillium crustaceum and fungal taxa that are considered to be cl osely related. The hexane and chloroform extracts of E. crustaceum NRR L 3332 displayed significant antiinsectan activity in assays against t he corn earworm, Helicoverpa tea. The major metabolite accounting for this antiinsectan activity was a known aflavinine analog, 10,23-dihydr o-24,25-dehydroaflavinine, occurring at approximately 2.8 mg/g of dry ascostromata, In dietary assays at ca, 3,000 ppm, a 79% reduction in w eight gain and a 42% reduction in feeding rate were observed in H. tea and Carpophilus hemipterus larvae, respectively, A new aflavinine ana log, 10,23,24,25-tetrahydro-24-hydroxyaflavinine was also identified, These aflavinine compounds are the first to be reported from a fungal genus other than Aspergillus, New macrophorin-type metabolites account ed for the antiinsectan activity of ascostromata produced by E. crusta ceum NRRT 22307, which produced no aflavinines, while Eupenicillium mo lle NRRL 13062 produced both aflavinines and macrophorins. Sclerotia p roduced by Penicillium gladioli NRRL 938, NRRL 939, and QM 2743, a fun gus reported to be conspecific with the anamorph off. crusfaceum, prod uced neither aflavinines nor macrophorins, Eupenicillium reticulisporu m NRRL 3446 produced the aflavinine analog 10,23-dihydro-24,25-dehydro aflavinine and an unrelated compound called pyripyropene A, a potent i nhibitor of acyl-coenzyme A-cholesterol acyltransferase, Eupenicillium abidjanum NRRL, 5809, reported to be conspecific with E. reticulispor um, produced neither of these compounds, The Eupenicillium species tha t produced aflavinines are also known for their ability to grow rapidl y with reduced water activity.