chapter  20
12 Pages

Exploring the Potential of Biologically Active Compounds from Plants and Fungi

Our research concentrates on screening extracts from plants and insectpathogenic fungi for novel pesticidal chemistries with high target selectivity and environmental compatibility. Our search is directed to narrowly defined and relatively untapped biological organisms. We also are interested in improving techniques for extracting and quantifying known secondary metabolites to refine our understanding of the roles these compounds play in nature and agroecosystems, and their potential roles in managing crop pests and diseases. Extracts of culture broth from the fungal genus

Aschersonia

sp., exhibited insecticidal activity in a

per os

assay against

Drosophila melanogaster

. Two new cyclic depsipeptides, Destruxins A4 and A5, were isolated by bioassay-guided fractionation. These are the first biologically active metabolites reported from an

Aschersonia

. Concentrations which resulted in 50% mortality of the population of

D

.