Epoxidases Involved in the Biosynthesis of Type II Sex Pheromones

Abstract

In moth species that utilize alkenyl (type II) sex pheromones, selective epoxidation of double bonds in the alkene pheromone components confers further diversity on their chemical structures. Two arctiids, the fall webworm Hyphantria cunea and the mulberry tiger moth Lemyra imparilis, use the same epoxyalkene, Z3,Z6,epo9-21:H, as the main pheromone component. In these species, we recently identified cytochrome P450s (CYPs) belonging to the CYP341 family as enzymes involved in the specific epoxidation of a Z9 double bond of the pheromone precursor Z3,Z6,Z9-21:H. Furthermore, a cytochrome P450 belonging to a different family, CYP340, was identified as an enzyme responsible for the specific epoxidation of a Z3 double bond of the pheromone precursor Z3,Z6,Z9-19:H in the Japanese giant looper Ascotis selenaria, which uses epo3,Z6,Z9-19:H as the main pheromone component. These findings suggest that epoxidases (CYPs) with different regio-specificities evolved independently.