title: Sex pheromone biosynthetic pathway for disparlure in the gypsy moth, Lymantria dispar.
abstract: The pheromone biosynthetic pathway for production of the sex pheromone disparlure, 2-methyl-7R,8S-epoxy-octadecane, was determined for the gypsy moth. Each step in the pathway was followed by using deuterium-labeled compounds that could be identified by using GCMS. This approach provides unequivocal determination of specific reactions in the pathway. It was shown that the alkene precursor, 2-methyl-Z7-octadecene, is most likely made in oenocyte cells associated with abdominal epidermal cells. The pathway begins with valine contributing carbons for chain initiation, including the methyl-branched carbon, followed by chain elongation to 19 carbons. The double bond is introduced with an unusual Delta12 desaturase that utilizes a methyl-branched substrate. The resulting 18-methyl-Z12-nonadecenoate is decarboxylated to the hydrocarbon, 2-methyl-Z7-octadecene. The alkene is then transported to the pheromone gland through the hemolymph, most probably by lipophorin. At the pheromone gland, the alkene is unloaded and transformed into the epoxide disparlure for release into the environment. A chiral HPLC column was used to demonstrate that the (R,S)-stereoisomer of the epoxide, (+)-disparlure is found in pheromone glands.
authors.affiliation: Department of Entomology, 407 Science II, Iowa State University, Ames, IA 50011-3222, USA. rjurenka@iastate.edu
authors.forename: Russell A
authors.initials: RA
authors.lastname: Jurenka
authors.forename: Mitko
authors.initials: M
authors.lastname: Subchev
authors.forename: Jose-Luis
authors.initials: JL
authors.lastname: Abad
authors.forename: Man-Yeon
authors.initials: MY
authors.lastname: Choi
authors.forename: Gemma
authors.initials: G
authors.lastname: Fabrias
mesh_terms: D000473:Alkanes / Q000737:chemistry* / Q000378:metabolism; D000818:Animals; D002851:Chromatography, High Pressure Liquid; D004852:Epoxy Compounds / Q000737:chemistry; D008401:Gas Chromatography-Mass Spectrometry; D009036:Moths; D012724:Sex Attractants / Q000096:biosynthesis*; D013237:Stereoisomerism; D013997:Time Factors; D014633:Valine / Q000737:chemistry
chemical_list: D000473:Alkanes; D004852:Epoxy Compounds; D012724:Sex Attractants; C001150:disparlure; D014633:Valine