Sulphonyl thiourea compounds containing pyrimidine as dual inhibitors of I, II, IX, and XII carbonic anhydrases and cancer cell lines: synthesis, characterization and in silico studies

Abstract

Some novel sulphonyl thiourea derivatives (7a–m) containing 4,6-diarylpyrimidine rings were designed and synthesized using a one-pot procedure. These compounds exhibited remarkable dual inhibitory activity against human carbonic anhydrase hCA I, hCA II, hCA IX, and XII isoenzymes and some cancer cell lines. Among them, some thioureas had significantly more potent inhibitory activities in the order of 7l > 7c > 7f (against the hCA I isoform), 7f > 7b > 7c (against the hCA II isoform), 7c > 7g > 7a > 7b (against the hCA IX isoform), and 7d > 7c > 7g > 7f (against the hCA XII isoform). The obtained inhibitory activity data against the hCA IX and XII isoforms showed that compound 7c was the most potent inhibitor in this sulphonyl thiourea series against enzyme hCA IX, with K_I = 125.1 ± 12.4 nM, while compound 7d was the most potent inhibitor against enzyme hCA XII, with K_I = 111.0 ± 12.3 nM. Compound 7c exhibited strong inhibitory activity among all four tested hCA enzymes, while thiourea 7f was a potent inhibitor for enzymes hCA I, II and XII. All these compounds demonstrated non-competitive inhibition of both enzymes. Some selected potential inhibitory compounds, including 7c, 7d, and 7g, exhibited remarkable cytotoxic activity against human cancer cell lines, including human breast adenocarcinoma (MCF-7), human liver adenocarcinoma (HepG2), human cervical epithelial carcinoma (HeLa), and human lung adenocarcinoma cells (A549). These compounds exhibited low cytotoxicity in the WI-38 cell line. The compounds 7c and 7d were the most potent inhibitors against tumour-associated hCA IX and hCA XII isoenzymes. Furthermore, these compounds exhibited remarkable inhibition against some cancer cell lines, such as MCF-7, HepG2, HeLa, and A549. They were subjected to in silico screening for molecular docking and molecular dynamics simulations. The results of in vitro and in silico studies revealed that compounds 7c and 7d were the most promising derivatives in this series owing to their significant effects on the studied hCA IX and hCA XII isoenzymes, respectively. The results showed that the sulphonyl thiourea moiety was deeply accommodated in the active site and interacted with zinc ions in the receptors.