The investigation of antiglaucoma effects of sulfobenzoic acid derivatives on human carbonic anhydrase enzyme

Carbonic anhydrase (E.C. 4. 2. 1. 1), is a metaloenzyme, located in the center Zn+2. The substrate of this enzyme is CO2 in vertebrate. This enzyme catalyzes conversion of CO2 to H2CO3 at cells and intracellular fluid. The isoenzymes of human eye are CA-II and CA-IV. CA-II isoenzyme is very important for using treatment of glaucoma.In this study, the inhibitory effects of the compounds were investigated on carbonic anhydrase enzyme.Firstly, erythrocyte carbonic anhydrase isoenzymes (CA-I, CA-II) from human erythrocyte were separately purifed by affinity chromatography.Later, inhibition effects of these new compounds (1, 2) on human carbonic anhydrase enzymes (CA I and CA II) were investigated in vitro. In the studies, it was taken advantage of hydrates and esterase activites for determining of carbonic anhydrase activitates. It was observed that compounds (1, 2) showed inhibition effect on human erythrocyte CA hydratase and esterase activity. I50 values were determined by drawing % activity-[I] graphs for drugs showing inhibition effects. For CO2-hydratase activity of compound (1), (2) inhibition effect ranged from 0,26 to 0,13 ? M for human erythrocyte CA I and 0,30 to 0,15 ? M with I50 for human erythrocyte CA II (molarity of inhibitor producing a %50 inhibition of CA activity). As for esterase activity of p-nitrophenyl acetate, compounds (1), (2) had inhibition ranging from 0,32 to 0,045 ? M for human erythrocyte CA I and 0,29 to 0,23 ? M for human erythrocyte CA II with I50.