Jp. Shapiro et al., Dehydrothalebanin: A source of resistance from Glycosmis pentaphylla against the citrus root weevil Diaprepes abbreviatus, J AGR FOOD, 48(9), 2000, pp. 4404-4409
Roots of a citrus relative, Glycosmis pentaphylla (orangeberry), were shown
to inhibit, the growth and survival of larvae of the citrus root weevil Di
aprepes abbreviatus. Roots of G. pentaphylla incorporated into the diet of
D. abbreviatus increasingly inhibited the growth of neonate larvae with inc
reased concentration of roots, while roots from citrus rootstocks produced
little inhibition. The diet-incorporation assay was used to guide fractiona
tion of an active acetone extract of G. pentaphylla roots. Three major frac
tions from silica open-column liquid chromatography were active, and these
were purified using semipreparative normal-phase HPLC. A single active HPLC
subfraction was isolated from each of the three Liquid chromatography frac
tions, and two active compounds were isolated and identified by GC-MSD. GC-
MSD and NMR identified one compound as the amide dehydrothalebanin B, and t
he other was identified by GC-MSD as dieldrin, a chlorinated hydrocarbon in
secticide whose origin in our samples is uncertain.