Synthesis, Moleculer Modeling, and Carbonic Anhydrase Inhibitor Effects of Novel 1-(1-benzyl-2-oxoindolin-3-ylidene)-4-(3-sulfamoylphenyl)thiosemicarbazides.

In this study, we describe the synthesis of new 1-(1-benzyl-2-oxoindolin-3-ylidene)-4-(3-sulfamoylphenyl)thiosemicarbazides and evaluate their inhibitory activity against hCAs (6a-l). The inhibitory effects of compounds 6a-l were examined in vitro against hCA I, II, IX, and XII isoforms. Acetazolamide (AAZ) was employed as the standard reference compound in this study. The compounds 6a-l inhibited the tumor-associated hCA IX and XII isoenzymes at nanomolar levels, and showed weak inhibitory effects on the off-target hCA I and II isoenzymes. Selectivity index (SI) values of compounds 6a-l were determined to be significantly high for hCA IX and XII over hCA I and II compared to AAZ. Compound 6k (R1 = Cl, R2 = 3-Cl) showed the strongest inhibitory effect (Ki = 25.23 nM) and high selectivity (SI = 225, 185) against hCA IX over hCA I and II. Compound 6f (R1 = CH3, R2 = 4-Cl) was found to have the highest inhibitory effect (Ki = 36.65 nM) and high selectivity (SI = 377 and 192, respectively) against hCA XII over hCA I and II. Molecular docking and dynamic simulation analyses were conducted to explore how compounds 6f and 6k interact with active sites of hCA XII and IX enzymes.