A HETEROCYCLIC OXIME FROM A FUNGUS WITH ANTI-JUVENILE HORMONE-ACTIVITY

Two fractions obtained after chromatography of dichloromethane extract of Penicillium brevicompactum culture medium showed anti-juvenile hor mone activity. One was active when assayed in vivo against Oncopeltus fasciatus third-instar nymphs, whereas the other showed a strong in vi tro inhibition of JH III biosynthesis on Locusta migratoria corpora al lata. A subfraction of the latter, constituting 97% of this fraction, is a main component that possessed the juvenile hormone biosynthesis i nhibitory activity. Chemical characterization of this compound shows a sesquiterpene-like structure, molecular mass of 278.16185 daltons, co rresponding to an empirical formula of C15H22N2O3 named brevioxime. Ev idence suggests that the final steps of JH III biosynthesis are the ta rget of the active compound. Its effects may be compared with those of a known inhibitor of P-450-Linked epoxidase, KH-42 yl-5-[(E)-2,6-dime thyl-1,5-heptadienyl]imidazole), whose effects on L. migratoria corpor a allata are also reported here for the first time. (C) 1998 Wiley-Lis s, Inc.