title: 2,3-Dihydrohomofarnesal: female sex attractant pheromone component of Callosobruchus rhodesianus (Pic).
abstract: Callosobruchus rhodesianus (Pic) (Coleoptera: Chrysomelidae: Bruchinae) is a pest of stored legumes through the Afro-tropical region. In laboratory bioassays, males of C. rhodesianus were attracted to volatiles collected from virgin females. Collections were purified by various chromatographic techniques, and the biologically active component isolated using gas chromatographic-electroantennographic detection analysis. Gas chromatography-mass spectrometry and NMR analyses suggested that the active compound was 2,3-dihydrohomofarnesal, i.e., 7-ethyl-3,11-dimethyl-6,10-dodecadienal. The structure was confirmed by non-stereoselective and enantioselective total synthesis. Using chiral gas chromatography, the absolute configuration of the natural compound was confirmed as (3S,6E)-7-ethyl-3,11-dimethyl-6,10-dodecadienal. Y-tube olfactomter assays showed that only the (S)-enantiomer attracted males of C. rhodesianus. The (R)-enantiomer and racemate did not attract males, suggesting that the (R)-enantiomer inhibits the activity of the natural compound. In combination with previous reports about sex attractant pheromones of congeners, we suggest that a saltational shift of the pheromone structure arose within the genus Callosobruchus.
authors.affiliation: Department of Biosciences, Faculty of Applied Bioscience, Tokyo University of Agriculture, Tokyo 156-8502, Japan. k3shimom@nodai.ac.jp
authors.forename: Kenji
authors.initials: K
authors.lastname: Shimomura
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Koshino
authors.forename: Arata
authors.initials: A
authors.lastname: Yajima
authors.forename: Noriko
authors.initials: N
authors.lastname: Matsumoto
authors.forename: Yuuma
authors.initials: Y
authors.lastname: Kagohara
authors.forename: Koichi
authors.initials: K
authors.lastname: Kamada
authors.forename: Shunsuke
authors.initials: S
authors.lastname: Yajima
authors.forename: Kanju
authors.initials: K
authors.lastname: Ohsawa
mesh_terms: D000818:Animals; D002849:Chromatography, Gas; D001517:Coleoptera / Q000737:chemistry* / Q000187:drug effects; D005204:Farnesol / Q000031:analogs & derivatives* / Q000032:analysis / Q000302:isolation & purification / Q000494:pharmacology; D005260:Female; D008297:Male; D013058:Mass Spectrometry; D012724:Sex Attractants / Q000032:analysis* / Q000302:isolation & purification* / Q000494:pharmacology
chemical_list: C553412:2,3-dihydrohomofarnesal; D012724:Sex Attractants; D005204:Farnesol; C084519:farnesal