Molecular parameters and olfaction in the oriental fruit fly Dacus dorsalis.

The methyl eugenol receptor of the male oriental fruit fly (Dacus dorsalis) has been further characterized by evaluating the role of the linear free energy parameters product operator and sigma in the depolarization of the receptor by 37 substituted 3,4-dimethoxybenzenes. There was a strong positive correlation between the hydrophobic character of the primary substituent and intense odor and a positive correlation between the electron donating property of the primary substituent and intense odor. Maximum odor intensity was also associated with substituents of 3 atomic diameters and was improved by a center of unsaturation. Preference tests suggest that this simple and versatile odor receptor can serve as a model for investigation of molecular interactions between receptors and odorant molecules.