Evaluation Of Pyrazoline-Bearing Primary Sulfonamides As Potent Inhibitors of Lactoperoxidase

Lactoperoxidase (LPO E.C. 1.11.1.7) is a glycoprotein belonging to the class of oxidoreductases and constitutes a notable member of the peroxidase enzyme family. The biological significance of LPO is attributed to its role as a natural defense system against microbial infection. In the current study, to examine the inhibitory effects of 8 different polyfluoro-substituted pyrazoline-type primary sulfonamide derivative compounds on LPO enzyme activity, LPO enzyme was extracted from buffalo milk and purified using affinity gel, resulting in a 2212.45-fold purification, a 19.31 % yield, and a specific activity of 4955.9 EU/mg. Ki values for the active inhibitors were determined to be between 1.02±0.53-6.67±2.94 µM, while their IC50 values were in the range of 0.144±0.03-0.798±0.07 µM. The IC50 value and Ki values for the most effective inhibitor, Compound 3, were calculated as 0.144±0.03 and 6.06±4.06 µM, respectively, and it was found that this compound inhibited LPO enzyme activity non-competitively.