Compound 7h(Kafrelsheikh University)

Overexpression of carbonic anhydrases IX and XII due to hypoxia contributes to tumor acidification and progression, suggesting that selective inhibitors may serve as effective anticancer agents. Thirteen piperidine-linked benzenesulfonamides (7a-k, 9, and 11) were synthesized and assessed for their inhibitory activity against hCA I, IX, and XII. Compounds 7h (4-fluoro) and 7b (4-hydroxy) were identified as the most effective inhibitors of hCA IX (K_i = 1.2 nM) and hCA XII (K_i = 4.3 nM), respectively. In the context of chemically induced hypoxia, 7h demonstrated an inhibitory effect on MCF-7 breast cancer cell proliferation, with an IC₅₀ value of 1.20 μM. Molecular docking with PDB codes 5FL4 and 4WW8 demonstrated significant Zn²⁺ coordination by the sulfonamide group, Thr-mediated hydrogen bonding, and supplementary amide- and aromatic-mediated interactions that elucidate the observed SAR trends. Molecular dynamics simulations of both hCA IX and XII complexes confirmed the stability and favorable binding modes of compounds 7b and 7h over 100 ns trajectories, corroborating their high predicted affinities. The findings indicate that customized sulfonamide-piperidine scaffolds can produce effective and selective CA IX/XII inhibitors with antiproliferative properties, establishing a foundation for further optimization in anticancer therapeutics.