Structure-activity studies of 3-benzoylpropionic acid derivatives suppressing adjuvant arthritis

3-Benzoylpropionic acid derivatives possess an immunomodulative activity and suppress adjuvant arthritis. To understand how substituents affect the biological activity, the quantitative structure-activity relationships of 30 compounds were analyzed by the adaptive least-squares method. For the suppressing activity in rats, the electronic effects and the structural feature of the substituent on benzene ring were suggested to be important. To reinforce and confirm the correlation, 4 additional compounds of phenoxybutyric acid derivatives were synthesized and tested with the rat adjuvant-induced arthritis. These compounds were found to have potent suppressing activity.