title: Male-specific sesquiterpenes from Phyllotreta flea beetles.
abstract: Flea beetles in several genera are known to possess male-specific sesquiterpenes, at least some of which serve as aggregation pheromones that attract both sexes. In continuing research on the chemical ecology of Phyllotreta flea beetles, six new male-specific sesquiterpenes were identified, one from P. striolata (hydroxyketone 9) and five from P. pusilla (aldehydes 10-12 and 14 and alcohol 13); both species are crop pests. The minute amounts from beetles provided mass spectra and chromatographic data but were insufficient for complete structure determination. However, it was discovered that the new compounds could all be produced by applying organic reactions to previously identified flea beetle sesquiterpenes, and the resulting, larger amounts of material permitted definitive structure analysis by NMR. Molecular modeling was used in conjunction with NMR to define relative configurations of several newly created stereogenic centers. The absolute configurations of natural 9-14 were established by chiral gas chromatography/mass spectrometry. In electrophysiological tests (GC-EAD) conducted with P. striolata, compound 9 was detected with high sensitivity by the beetle antennae, which is consistent with a pheromonal function. The research opens new possibilities for using behavioral chemicals to monitor or manage these pest species.
authors.affiliation: USDA Agricultural Research Service, National Center for Agricultural Utilization Research, 1815 North University Street, Peoria, Illinois 61604, USA. Robert.Bartelt@sbcglobal.net
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Bartelt
authors.forename: Bruce W
authors.initials: BW
authors.lastname: Zilkowski
authors.forename: Allard A
authors.initials: AA
authors.lastname: Cossé
authors.forename: Udo
authors.initials: U
authors.lastname: Schnupf
authors.forename: Karl
authors.initials: K
authors.lastname: Vermillion
authors.forename: Frank A
authors.initials: FA
authors.lastname: Momany
mesh_terms: D000818:Animals; D001937:Brassica / Q000469:parasitology; D001517:Coleoptera / Q000737:chemistry* / Q000502:physiology*; D005260:Female; D008401:Gas Chromatography-Mass Spectrometry; D008297:Male; D015394:Molecular Structure; D010572:Pest Control, Biological; D010675:Pheromones / Q000737:chemistry / Q000302:isolation & purification* / Q000502:physiology*; D012717:Sesquiterpenes / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*
chemical_list: D010675:Pheromones; D012717:Sesquiterpenes