Identification of New Anti-Glaucoma Agents With Emphasis on the Inhibition of Carbonic Anhydrase Enzyme

Carbonic anhydrase is metal-containing enzyme that contains Zn and involves the carboxylation of water into carbonic acid, which normally converts into bicarbonate and protons Carbonic anhydrase inhibitors (CAIs) are utilized to lower the intraocular pressure (IOP) in glaucoma condition and also decrease the inflammation associated with increasing ocular hemodynamics, and ocular apoptosis. During the course of research period, a number of synthesized compounds were analyzed by bovine carbonic anhydrase-II (bCA-II) for development of new inhibitors. For this purpose high throughput biochemical mechanism based assay was employed for the identification of new inhibitors of CA-II enzyme. Spectra max-340 and M2 spectrophotometer from Molecular Devices (USA) were used to measure the inhibition potential through absorbance. Out of numerous classes of compound only schiff bases of triazole, tosylhydrazone (sulfonohydrazone), benzylidene and thiourea derivatives, were found to be good inhibitors of CA-II. The identified inhibitors were subjected to IC50 determination by serial dilution. The Ez-fit enzyme kinetics soft were employed to calculate the IC50 values from the % inhibition. The benzylidene derivatives exhibited. IC50 values in the range of 52.68 ? 0.47 to 348.57 ? 3.32 ?M. Schiff Bases of triazole derivatives have shown IC50 values between 98.23 ? 1.60 to 285.87 ? 2.67 ?M. While thiourea derivative exhibit excellent inhibition potential which illustrated IC50 values in the range of 1.90 ? 1.30 to 25.90 ? 2.05 ?M when compared with the standard inhibitor acetazolamide IC50 = 0.13 ? 0.05. Among all the compounds thiourea derivatives can serve as lead compounds for the identification of new inhibitors of CA-II.