ABSTRACT
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
.
