A heterocyclic oxime from a fungus with anti-juvenile hormone activity

Abstract

Two fractions obtained after chromatography of dichloromethane extract of Penicillium brevicompactum culture medium showed anti-juvenile hormone activity. One was active when assayed in vivo against Oncopeltus fasciatus third-instar nymphs, whereas the other showed a strong in vitro inhibition of JH III biosynthesis on Locusta migratoria corpora allata. A subfraction of the latter, constituting 97% of this fraction, is a main component that possessed the juvenile hormone biosynthesis inhibitory activity. Chemical characterization of this compound shows a sesquiterpene-like structure, molecular mass of 278.16185 daltons, corresponding to an empirical formula of C15H22N2O3 named brevioxime. Evidence suggests that the final steps of JH III biosynthesis are the target of the active compound. Its effects may be compared with those of a known inhibitor of P-450-linked epoxidase, KK-42 (1-benzyl-5-[(E)-2,6-dimethyl-1,5-heptadienyl]imidazole), whose effects on L. Migratoria corpora allata are also reported here for the first time. Arch. Insect Biochem. Physiol. 37:287–294, 1998. © 1998 Wiley-Liss, Inc.