Quantitative structure-activity relationship was studied on antimutagenic phenol carboxylic acids. Antimutagenic activities of 117 compounds were examined with Ames test by using Salmonella typhimurium TA98 with S9 mix. Benzo[a]pyrene was used as a reference mutagenic substance. Seven compounds which were hardly soluble in the test medium and six compounds which showed a killing effect were omitted in the evaluation of antimutagenicity. Theory of quantification I was applied to this study. The chemical structures of the above 104 compounds were classified into 3 items : principal structure, substituent groups, and the functional groups of side chain. The results between the range of standardized categorical weight and partial coefficient did not coincide. As the categorical weight of phenols was so great, that 10 phenols compounds were omitted, and then recalculated. It was found that φR (1) OH (3, 4, 5), coumarin, φR (1) OCH3 (3, 4, 5), and φR (1) OH (2, 4, 6) acted for enhancing antimutagenicity, while φR (1) CHO (4), φR (1) COOH (2), and φR (1) COOH (4) acted for enhancing mutagenicity. The regression line of structure-antimutagenic activity lied in Y=0.62X+9.15. (The following symbols are used : X, Y ; observed and calculated values of antimutagenic activity, respectively, φ ; benzene ring, R ; side chain, and the numbers in parentheses ; the numbers of position for substituent groups)
