Synthesis and biological evaluation of novel 4,7-disubstituted coumarins as selective tumor-associated carbonic anhydrase IX and XII inhibitors.

With an aim to develop novel potential anti-cancer agents we have designed a series of novel 4,7-disubstituted coumarin hybrids synthesis and evaluated for their inhibitory activity against the human carbonic anhydrase isoforms namely CA I, CA II, CA IX and CA XII. The results of CA inhibition clearly showed that the novel 4, 7-disubstituted coumarin hybrids (7a-i & 8a-j) exhibited selective inhibition towards tumor associated isoforms, CA IX and CA XII without inhibiting CA I and CA II isoforms. Among all the compound 8b showed a significant inhibition against hCA IX with a Ki of 0.58 µM whereas, the compound 7c showed a significant inhibition against hCA XII with a Ki of 0.36 µM respectively. All other compounds have shown a good inhibition against hCA IX and hCA XII over hCA I and hCA II within the range of 0.46 to 9.35 µM. Therefore, compound 8b and 7c would be the potential leads for developing selective cytotoxic agents targeting hCA IX and XII.