Synthesis and biological evaluation of novel aromatic and heterocyclic bis-sulfonamide Schiff bases as carbonic anhydrase I, II, VII and IX inhibitors

A series of sixteen novel aromatic and heterocyclic bis-sulfonamide Schiff bases were prepared by conjugation of well known aromatic and heterocyclic aminosulfonamide carbonic anhydrase (CA, EC 4.2.1.1) inhibitor pharmacophores with aromatic and heterocyclic bis-aldehydes. The obtained bis-sulfonamide Schiff bases were investigated as inhibitors of four selected human (h) CA isoforms, hCA I, hCA II, hCA VII and hCA IX. Most of the newly synthesized compounds showed a good inhibitory profile against isoforms hCA II and hCA IX, also showing moderate selectivity against hCA I and VII. Several efficient lead compounds were identified among this bis-sulfonamide Schiff bases with low nanomolar to sub-nanomolar activity against hCA II (Kis ranging between 0.4 and 861.1 nM) and IX (Kis between 0.5 and 933.6 nM). Since hCA II and hCA IX are important drug targets (antiglaucoma and anti-tumor agents), these isoform-selective inhibitors may be considered of interest for various biomedical applications.