Pyridazinone substituted benzenesulfonamides as potent carbonic anhydrase inhibitors

A series of sulfonamide derivatives (2a-l) incorporating substituted pyridazinone moieties were investigated for the inhibition of two human cytosolic carbonic anhydrase isoforms, hCA I and hCA II. All these compounds, together with the clinically used sulfonamide acetazolamide were investigated as inhibitors of the physiologically relevant isozymes I and II. These sulfonamides showed very strong inhibition against all these isoforms with K-I's in the range of 0.98-8.5 nM which makes such molecules possible to be used as leads for discovery of novel effective CA inhibitors targeting other isoforms with medicinal chemistry applications. (C) 2016 Elsevier Ltd. All rights reserved.