Sex pheromone biosynthesis in the red-banded leafroller moth, studied by mass-labeling with stable isotopes and analysis with mass spectrometry

Abstract

A technique for mass-labeling was developed to study sex pheromone biosynthesis in the red-banded leafroller moth, Argyrotaenia velutinana . With this technique, the pheromone components and all fatty acyl groups in the pheromone gland were analyzed for incorporation of label in the same analytic ran with gas chromatography-mass spectrometry, using chemical ionization and selected ion monitoring (GC-SIM-CI-MS). Sex pheromone glands were incubated with fatty acids or triacylglycerols labeled with at least three deuterium atoms or carbon-13 atoms. The results of these incubations support an interpretation in which hexadecanoate is chain shortened to tetradecanoate, which is desaturated to produce ( E )- and ( Z )-11-tetradecenoate precursors for the sex pheromone components ( E )- and ( Z )-11-tetradecen-1-yl acetate. Labeled ( E )- and ( Z )-11-tetradecenoyl groups in synthetic triacylglycerols were not incorporated into the sex pheromone components, perhaps indicating that this lipid class is not a donor of the immediate fatty acyl precursors in sex pheromone biosynthesis.