Direct inhibition of (Z)-9 desaturation of (E)-11-tetradecenoic acid by methylenehexadecenoic acids in the biosynthesis of Spodoptera littoralis sex pheromone.

G Fabrias; L Gosalbo; J Quintana; F Camps

Direct inhibition of (Z)-9 desaturation of (E)-11-tetradecenoic acid by methylenehexadecenoic acids in the biosynthesis of Spodoptera littoralis sex pheromone.

1996

G Fabrias | L Gosalbo | J Quintana | F Camps

Analysis by gas chromatography coupled to mass spectrometry demonstrated that 11,12-methylenehexadec-11-enoic acid and 12,13-methylenehexadec-12-enoic acid are beta-oxidized in Spodoptera littoralis sex pheromone gland to 9, 10-methylenetetradec-10-enoic acid and 10,11-methylenetetradec-10-enoic acid, respectively. This result supported our previous hypothesis that inhibition of the (Z)-9 desaturation of (E)-11-tetradecenoic acid by those C-16 fatty acids is actually caused by their corresponding beta-oxidation products. However, although (2,2,3,3-2H4)-11,12-methylenehexadec-11-enoic acid was not chain-shortened to the C-14 derivative, its activity as inhibitor of the (Z)-9 desaturation reaction was similar to that exhibited by 11,12-methylenehexadec-11-enoic acid. Therefore, the C-16 cyclopropene fatty acids may inhibit the (Z)-9 desaturation enzyme by themselves, probably through interaction of the cyclopropene ring with a binding site of the enzyme with the substrate double bond.

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