Hypoxic solid tumors overexpress a transmembrane enzyme; Carbonic Anhydrase XII (CA XII) to regulate pH and promote tumor progression. Selective inhibition of CA XII is believed to be a promising anticancer approach. Many studies were designed to introduce a molecule with high selectivity to cancer associated CA isoforms, but they faced issues like selectivity, safety, and potency. This study aimed to design and computationally evaluate novel isatin-sulfonamide hybrids as effective and selective CA XII inhibitors with enhanced safety profile. Six hybrid compounds were designed and assessed using molecular docking against the CA XII active site (PDB:8CO3), utilizing the selective ligand V8O and non-selective acetazolamide (AZM) as references. Molecular docking identified compounds 5 and 6 as having highest affinity score (-7.069 kcal/mol) and (-6.614 kcal/mol) respectively. Further evaluation using MM-GBSA binding free energy estimation emphasized compound 6 as the most thermodynamically favorable candidate (ΔGbind = -19.93 kcal/mol), principally determined by strong van der Waals as well as lipophilic interactions. The stability of the compound 6–CA XII complex was established over a 200 ns molecular dynamics simulation, which confirmed a stable binding position. In silico ADME predictions showed that most compounds, especially compound 6, have acceptable pharmacokinetic properties except oral bioavailability. In silico investigations indicate that all designed hybrids showed improved toxicity profile, rendering them of low acute toxicity (Class 5, LD₅₀ 4000-5000 mg/kg) and predicted to lack carcinogenic potential, in contrast to the reference ligand V8O. In conclusion, these computational results present these derivatives, especially compound 6 as promising candidates with moderate suggested selectivity, and predicted to be safe CA XII-inhibitor for further experimental development as an anticancer agent.

Hypoxic solid tumors overexpress a transmembrane enzyme; Carbonic Anhydrase XII (CA XII) to regulate pH and promote tumor progression. Selective inhibition of CA XII is believed to be a promising anticancer approach. Many studies were designed to introduce a molecule with high selectivity to cancer associated CA isoforms, but they faced issues like selectivity, safety, and potency. This study aimed to design and computationally evaluate novel isatin-sulfonamide hybrids as effective and selective CA XII inhibitors with enhanced safety profile. Six hybrid compounds were designed and assessed using molecular docking against the CA XII active site (PDB:8CO3), utilizing the selective ligand V8O and non-selective acetazolamide (AZM) as references. Molecular docking identified compounds 5 and 6 as having highest affinity score (-7.069 kcal/mol) and (-6.614 kcal/mol) respectively. Further evaluation using MM-GBSA binding free energy estimation emphasized compound 6 as the most thermodynamically favorable candidate (ΔGbind = -19.93 kcal/mol), principally determined by strong van der Waals as well as lipophilic interactions. The stability of the compound 6–CA XII complex was established over a 200 ns molecular dynamics simulation, which confirmed a stable binding position. In silico ADME predictions showed that most compounds, especially compound 6, have acceptable pharmacokinetic properties except oral bioavailability. In silico investigations indicate that all designed hybrids showed improved toxicity profile, rendering them of low acute toxicity (Class 5, LD₅₀ 4000-5000 mg/kg) and predicted to lack carcinogenic potential, in contrast to the reference ligand V8O. In conclusion, these computational results present these derivatives, especially compound 6 as promising candidates with moderate suggested selectivity, and predicted to be safe CA XII-inhibitor for further experimental development as an anticancer agent.