Stereospecificity of the (Z)-9 desaturase that converts (E)-11-tetradecenoic acid into (Z,E)-9,11-tetradecadienoic acid in the biosynthesis of Spodoptera littoralis sex pheromone

Moth pheromone glands contain desaturases that catalyze the formation of co njugated dienoic fatty acids. In this article we present the first stereoch emical study on one of these enzymes, namely the Delta (9) desaturase of (E )-11-tetradecenoic acid, using the moth Spodoptera littoralis as a biologic al model and enantiopure deuterated probes derived from tridecanoic acid. G as chromatography coupled to mass spectrometry analysis of methanolyzed lip idic extracts from glands incubated with each individual probe showed that in the transformation of (E)-11-tetradecenoic acid into (Z,E)-9,11-tetradec adienoic acid both pro-(R) hydrogen atoms at C9 and C10 are removed from th e substrate. (C) 2001 Elsevier Science Ltd. All rights reserved.