Synthesis and Evaluation of Thiazolidinone-Isatin Hybrids for Selective Inhibition of Cancer-Related Carbonic Anhydrases

A small library of novel thiazolidinone-based sulfonamide derivatives was designed, synthesized and evaluated for their ability to target human carbonic anhydrase (hCA) isoforms IX and XII, which are overexpressed in malignant cells and play a key role in metastasis and therapeutic response of cancer cells. A molecular hybridization approach was employed to design the molecules by combining different moieties identified as having antitumor activity. The thiazolidinone core was functionalized with benzenesulfonamide as a zinc-binding group and different isatin derivatives to enhance the chemical profile and optimize the hydrophilic/lipophilic balance. Biological evaluation against hCA I, II, IX and XII isoforms showed promising inhibitory activities, and some compounds exhibited selectivity and high inhibitory activity against hCA IX and hCA XII while not affecting off-target hCA I and hCA II. In particular, compound 3h demonstrated high selectivity with Ki values of 57.8 nM for hCA IX and 44.3 nM for hCA XII.