Replacement of the terminal methyl group in a moth sex pheromone component by a halogen atom: Hydrophobicity and size effects on electrophysiological single-cell activities.

Analogs of (Z)-5-decenyl acetate, a pheromone component of the turnip moth,Agrotis segetum, with a chloro, bromo, or iodo substituent in place of the terminal methyl group have been synthesized and tested by electrophysiological single-sensillum recordings. The electrophysiological results have been interpreted in terms of substituent size and hydrophobicity. Interaction energies based on receptor interaction models have been calculated using the molecular mechanics [MM2(85)] method. The results support our previously suggested receptor interaction model in which the terminal alkyl chain interact with a complementary hydrophobic receptor "pocket" with very limited flexibility.