Piperazin incorporated Schiff Base derivatives: Assessment of in vitro biological activities, metabolic enzyme inhibition properties, and molecular docking calculations.

The cytotoxic activities of the compounds were determined by the 3-(4,5-dimethylthiazolyl-2)-2,5-diphenyltetrazolium bromide (MTT) method in human breast cancer (MCF-7), human cervical cancer (HeLa), and mouse fibroblast (L929) cell lines. The compounds MAAS-5 and four modified the supercoiled tertiary structure of pBR322 plasmid DNA. MAAS-5 showed the highest cytotoxic activity in HeLa, MCF-7, and L929 cells with IC50 values of 16.76 ± 3.22, 28.83 ± 5.61, and 2.18 ± 1.22 µM, respectively. MAAS-3 was found to have almost the lowest cytotoxic activities with the IC50 values of 93.17 ± 9.28, 181.07 ± 11.54, and 16.86 ± 6.42 µM in HeLa, MCF-7, and L929 cells respectively at 24 h. Moreover, the antiepileptic potentials of these compounds were investigated in this study. To this end, the effect of newly synthesized Schiff base derivatives on the enzyme activities of carbonic anhydrase I and II isozymes (human carbonic anhydrase [hCA] I and hCA II) was evaluated spectrophotometrically. The target compounds demonstrated high inhibitory activities compared with standard inhibitors with Ki values in the range of 4.54 ± 0.86-15.46 ± 8.65 nM for hCA I (Ki value for standard inhibitor = 12.08 ± 2.00 nM), 1.09 ± 0.32-29.94 ± 0.82 nM for hCA II (Ki value for standard inhibitor = 18.22 ± 4.90 nM). Finally, the activities of the compounds were compared with the Gaussian programme in the B3lyp, HF, M062X base sets with 6-31++G (d,p) levels. In addition, the activities of five compounds against various breast cancer proteins and hCA I and II were compared with molecular docking calculations. Also, absorption, distribution, metabolism, excretion, and toxicity analysis was performed to investigate the possibility of using five compounds as drug candidates.

New anthranilic acid-incorporating N-benzenesulfonamidophthalimides as potent inhibitors of carbonic anhydrases I, II, IX, and XII: Synthesis, in vitro testing, and in silico assessment.

The carbonic anhydrase (CA) inhibitory activity of newly synthesized compounds 4-21 against the human CA (hCA) isoforms I, II, IX, and XII was measured and compared to that of standard sulfonamide inhibitors, acetazolamide (AAZ) and SLC-0111. Among this series; benzensulfonamides 6-11 gave the best potent hCA inhibitors with inhibition constants (KIs) ranging from 81.9 to 456.6 nM (AAZ and SLC-0111: KIs, 250.0 and 5080 nM, respectively). Compounds 6-11 proved to be effective hCA II inhibitors (KIs, 8.9-51.5 nM); they were almost equally potent to AAZ (KI, 12.0 nM) and had superior potency to SLC-0111 (KI, 960.0 nM). For hCA IX inhibition, compounds 6-11 proved to be potent inhibitors, with KI values of 3.9-36.0 nM, which were greater than or equal to that of AAZ and greater than that of SLC-0111 (KIs, 25.0 and 45.0 nM, respectively). For hCA XII inhibitory activity, compounds 6-11 displayed effective inhibition with KI values ranging from 4.6 to 86.3 nM and were therefore comparable to AAZ and SLC-0111 (KIs, 5.7 and 4.5 nM, respectively). Molecular docking studies of compounds 6, 7, 10, and 11 were conducted using the crystal structures of hCA isozymes I, II, IX, and XII to study their binding interactions for further lead optimization.