Enantiomers of methyl substituted analogs of (Z)-5-decenyl acetate as probes for the chirality and complementarity of its receptor inAgrotis segetum 1: Synthesis and structure-activity relationships.

The enantiomers of analogs of (Z)-5-decenyl acetate, a pheromone component ofAgrotis segetum, substituted by a methyl group in the 2, 3, 4, 7, and 8 positions and dimethyl substituted in the 4,7 positions, have been synthesized and studied by an electrophysiological single-cell technique and by molecular mechanics calculations. The results demonstrate that the electrophysiological activity as well as the ability of the (Z)-5-decenyl acetate receptor to differentiate between enantiomers depends on the position of the methyl substituent. For analogs methyl substituted in the 2, 4, or 8 position, no differences in the activities of the enantiomers could be observed. In contrast, the enantiomers of the 3- and 7-methyl analogs display a significant difference in the activities, theR-enantiomers being more active than theS-enantiomers. From an analysis of the structure-activity results of the enantiomers of the 4,7-dimethyl-substituted analogs, the chiral sense of the alkylchain of the natural pheromone component on binding to its receptor could be deduced.