Secondary Sulfonamides as Effective Lactoperoxidase Inhibitors.

Secondary sulfonamides (-) incorporating acetoxybenzamide, triacetoxybenzamide, hydroxybenzamide, and trihydroxybenzamide and possessing thiazole, pyrimidine, pyridine, isoxazole and thiadiazole groups were synthesized. Lactoperoxidase (LPO, E.C.1.11.1.7), as a natural antibacterial agent, is a peroxidase enzyme secreted from salivary, mammary, and other mucosal glands. In the present study, the in vitro inhibitory effects of some secondary sulfonamide derivatives (-) were examined against LPO. The obtained results reveal that secondary sulfonamide derivatives (-) are effective LPO inhibitors. The K values of secondary sulfonamide derivatives (-) were found in the range of 1.096 × 10 to 1203.83 µM against LPO. However, the most effective inhibition was found for -(sulfathiazole)-3,4,5-triacetoxybenzamide (), with K values of 1.096 × 10 ± 0.471 × 10 µM as non-competitive inhibition.