Sulfamide derivatives with selective carbonic anhydrase VII inhibitory action.

A set of N,N'-disubstituted sulfamides and sodium cyclamate have been tested for their inhibitory action against six isoforms of carbonic anhydrase (CA, EC 4.2.1.1) found in the brain, that is, CA I, CA II, CA VII, CA IX, CA XII and CA XIV, some of which are involved in epileptogenesis. The biological data showed interesting results for CA VII inhibition, the isozyme thought to be a novel antiepileptic target. Strong CA VII inhibitors, with Ki values in the low nanomolar-subnanomolar range were identified. Some of these derivatives showed selectivity for inhibition of CA VII versus the ubiquitous isoform CA II, for which the Ki values were in the micromolar range. Molecular modeling approaches were employed to understand the binding interactions between these compounds and the two CA isoforms, since the mechanism of action of such disubstituted sulfamides was not yet investigated by means of X-ray crystallography.