Synthesis and characterization of 2,13- and 3,13-octadecadienals for the identification of the sex pheromone secreted by a clearwing moth.
In addition to 2,13- and 3,13-octadecadien-1-ols and their acetates, aldehyde analogs have been identified from lepidopteran species in the family Sesiidae. To establish a reliable analytical method for determining the positions and configurations of the two double bonds in natural pheromone components, all geometric isomers of the 2,13- and 3,13-octadecadienals were synthesized by Dess-Martin oxidation of the corresponding alcohols with limited isomerization of the double bond at the 2- or 3-position. GC-MS analysis of these aldehydes showed isomerization of (Z)-2-, (Z)-3-, and (E)-3-double bonds to an (E)-2-double bond, even with a cool on-column injection. In contrast, HPLC analysis with an ODS column was accomplished without isomerization. The geometric isomers of each dienal eluted in the order ZZ --> EZ --> ZE --> EE. The conjugated 2,13-dienals were detectable in nanogram amounts with a UV detector at 235 nm. Whereas the detection of 3,13-dienals was difficult because of the lack of a chromophore, a highly sensitive analysis was achieved after derivatization with 2,4-dinitrophenylhydrazine. LC-MS with atmospheric pressure chemical ionization showed a strong [M-1](-) at m/z 443 for the derivatives. Based on these analytical data, a pheromone extract of a sesiid moth, Macroscelesia japona, was examined by HPLC and LC-MS, and it was confirmed that the octadecadienal tentatively identified by a previous GC-MS analysis did indeed have the 2E,13Z configuration. Furthermore, field evaluation of four synthetic geometric isomers of the 2,13-dienal revealed specific attraction to a lure with the (2E,13Z)-isomer as a main component.
Islam
A
A
Graduate School of Bio-Applications and Systems Engineering (BASE), Tokyo University of Agriculture and Technology, Koganei, Tokyo 184-8588, Japan.
Yamamoto
Masanobu
M
Sugie
Mieko
M
Naka
Hideshi
H
Tabata
Jun
J
Arita
Yutaka
Y
Ando
Tetsu
T
D000447:Aldehydes / Q000138:chemical synthesis / Q000737:chemistry*; D000818:Animals; D002849:Chromatography, Gas; D002851:Chromatography, High Pressure Liquid; D005260:Female; D007536:Isomerism; D013058:Mass Spectrometry; D009036:Moths / Q000378:metabolism*; D012724:Sex Attractants / Q000138:chemical synthesis / Q000737:chemistry*
D000447:Aldehydes; D012724:Sex Attractants