Novel pyrazole-3,4-dicarboxamides bearing biologically active sulfonamide moiety as potential carbonic anhydrase inhibitors

In this study a series of pyrazole-3,4-dicarboxamide (3-10) derivatives bearing sulfonamide moiety were synthesized starting from 1-(3-nitrophenyl)-5-phenyl-1H-pyrazole-3,4-dicarboxylic acid (1). The structures of synthesized molecules were characterized by FT-IR, H-1 NMR, C-13 NMR, and elemental analysis methods. Human carbonic anhydrase isoenzymes (hCA I and hCA II) were purified separately from erythrocyte cells by the Sepharose-4B-L-tyrosine-sulfa nilamide affinity column chromatography and inhibitory effects of newly synthesized sulfonamides on esterase activities of these isoenzymes have been studied as in vitro. The K-i values of compounds were found in the range of 0.056-110.400 mu M for hCA I and 0.057-533.400 mu M for hCA II. Compound 4 has the highest inhibitory effect for hCA I and hCA II while compound 5 showed lowest inhibition. The structure-activity relationships for the inhibition of these isoforms with the pyrazole-sulfonamides reported here were also elucidated. (C) 2015 The Authors. Published by Elsevier B.V. on behalf of King Saud University. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).