Threshold-based structure-activity relationships of pyrazines with bell-pepper flavor

Quantitative structure activity relationships (QSAR) and comparative molecu lar field analysis (CoMFA) are applied in order to explain the aroma of 46 bell-pepper aroma compounds. Biological activities log(1/c) values are used , where c stands for the detection threshold value of the aroma compound in water. Results of conventional QSAR and CoMFA are both satisfactory in sta tistical significance and predictive ability. We construct a qualitative mo del using the graphic features of CoMFA together with the results of "class ical" QSAR analysis, which is performed by multiple linear regression. Fina lly, the human olfactory detection threshold values of excluded pyrazines a re successfully predicted. This makes CoMFA and QSAR two important tools fo r designing new aroma compounds and in elucidating the mechanism of odor-re ceptor interaction.