Sex Pheromone Biosynthesis in Trichoplusia ni: Key Steps Involve Delta-11 Desaturation and Chain-Shortening

In addition to the primary pheromone component (Z)-7-dodecenyl acetate, the sex pheromone gland of Trichoplusia ni contains the immediate fatty acyl precursor (Z)-7-dodecenoate and a large quantity of (Z)-11-hexadecenoate. Labeling experiments showed that (Z)-11-hexadecenoate is chain-shortened to (Z)-9-tetradecenoate, and that this in turn is chain-shortened to (Z)-7-dodecenoate. The same mechanism appears to explain the sex pheromone compositions of many other moth species.