title: Synthesis and chemical characterization of hydrocarbons with a 6,9,11-, 3,6,9,11-, or 1,3,6,9-polyene system, pheromone candidates in Lepidoptera.
abstract: Lepidopteran Type II sex pheromones are mainly composed of 6,9-dienes, 3,6,9-trienes, and their epoxy derivatives, which are biosynthesized from linoleic and linolenic acids by the species in some families of higher Lepidoptera. To investigate further structural modifications on this theme, we synthesized polyunsaturated hydrocarbons with a C(17)-C(21) chain, which included an extra double bond. Using the Wittig reaction, (Z,Z,E)-6,9,11-trienes and (Z,Z,Z,E)-3,6,9,11-tetraenes were synthesized from (E)-2-alkenals with appropriate carbon chains, and (Z,Z,Z)-1,3,6,9-tetraenes were synthesized from 3-hexyn-1,6-diol. The gas chromatography-mass spectrometry (GC-MS) analysis of each synthetic polyene, whose chemical structure was confirmed by (1)H NMR and (13)C NMR, revealed some characteristic fragment ions reflecting the positions of the double bonds, i.e., m/z 79, 110, 163, and M-85 of the 6,9,11-trienes, m/z 79, 108, and M-82 of the 3,6,9,11-tetraenes, and m/z 79, 91, 106, and M-54 of the 1,3,6,9-tetraenes. Because the determination of the unsaturated positions is difficult to accomplish by chemical derivatization with a limited amount of natural pheromones, these diagnostic ions found in authentic samples would help identify the hydrocarbons in a pheromone extract. Furthermore, we carried out field screening tests of these polyenes in forests in Japan, and documented the attraction of four geometrid species in Tokyo and one noctuid species in the Iriomote Islands.
authors.affiliation: Graduate School of Bio-Applications and Systems Engineering, Tokyo University of Agriculture and Technology, Koganei, Tokyo, 184-8588, Japan.
authors.forename: Masanobu
authors.initials: M
authors.lastname: Yamamoto
authors.forename: Rei
authors.initials: R
authors.lastname: Yamakawa
authors.forename: Toshiya
authors.initials: T
authors.lastname: Oga
authors.forename: Yousuke
authors.initials: Y
authors.lastname: Takei
authors.forename: Masakatsu
authors.initials: M
authors.lastname: Kinjo
authors.forename: Tetsu
authors.initials: T
authors.lastname: Ando
mesh_terms: D000818:Animals; D008401:Gas Chromatography-Mass Spectrometry; D006838:Hydrocarbons / Q000138:chemical synthesis / Q000737:chemistry*; D007536:Isomerism; D007915:Lepidoptera / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D011090:Polyenes / Q000737:chemistry*; D012724:Sex Attractants / Q000737:chemistry*
chemical_list: D006838:Hydrocarbons; D011090:Polyenes; D012724:Sex Attractants