Synthesis and characterization of novel dioxoacridine sulfonamide derivatives as new carbonic anhydrase inhibitors

Novel dioxoacridine sulfonamide compounds were synthesized from reaction of cyclic 1,3-diketones, sulfanilamide (4-amino benzene sulfonamide) and aromatic aldehydes. The structures of these compounds were confirmed by using spectral analysis (IR, H-NMR, C-13-NMR, and mass). Human carbonic anhydrase isoenzymes (hCA I and hCA II) were purified from erythrocyte cells by affinity chromatography. The inhibitory effects of sulfanilamide, acetazolamide (AAZ), and newly synthesized sulfonamides on hydratase and esterase activities of these isoenzymes have been studied in vitro. The IC50 values of compounds for esterase activity are 0.71-0.11 mu M for hCA I and 0.45-0.12 mu M for hCA II, respectively. The K-i values of these inhibitors were determined as 0,38-0,008 mu M for hCA I and 0,19-0,001 mu M for hCA II, respectively.