Inhibition of the acyl-CoA desaturases involved in the biosynthesis of Spodoptera littoralis sex pheromone by analogs of 10,11-methylene-10-tetradecenoic acid

The desaturase inhibitory activity of the cyclopropenyl alcohols 9,10-methylene-9-tetradecen-1-ol (9-MTOL), 10,11-methylene-10-tetradecen-1-ol (10-MTOL) and 11,12-methylene-11-tetradecen-1-ol (11-MTOL), which are structural analogs of 10,11-methylene-10-tetradecenoic acid (10-MTA), is reported. At equimolar ratios with respect to the different substrates, the three compounds completely inhibited the three desaturation reactions involved in the biosynthesis of Spodoptera littoralis sex pheromone. The dose-dependence of inhibition was determined for 10-MTA and its alcohol derivative. Both compounds inhibited the transformation of perdeuterated palmitic acid into perdeuterated (Z)-11-hexadecenoic acid and that of (E)-11-tridecenoic acid into (Z,E)-9,11-tridecadienoic acid with similar IC(50) values. The overall results presented in this work support scattered data that neither the free carboxyl groups nor their acyl-CoA esters are a requisite for inhibition of desaturases. Since the synthesis of cyclopropenols is much more convenient than that of cyclopropene fatty acids, this finding is of economical relevance regarding the putative use of cyclopropene derivatives in pest control.