Introduction: Carbonic anhydrases (CAs) are widespread metalloenzymes with the core function of catalyzing the interconversion of CO2 and HCO3-. Targeting these enzymes using selective inhibitors has emerged as a promising approach for the development of novel therapeutic agents against multiple diseases. Methods: A series of novel thiosemicarbazones-containing derivatives were synthesized, characterized, and tested for their inhibitory activity against pharmaceutically important human CA I (hCA I), II (hCA II), IX (hCA IX), and XII (hCA XII) using the single tail approach. Results: The compounds generally inhibited the isoenzymes at low nanomolar concentrations, with compound 6b having Ki values of 7.16, 0.31, 92.5, and 375 nM against hCA I, II, IX and XII, respectively. Compound 6e exhibited Ki values of 27.6, 0.34, 872, and 94.5 nM against hCA I, II, IX and XII, respectively. Conclusion: To rationalize the inhibition data, molecular docking studies were conducted, providing insight into the binding mechanisms, molecular interactions, and selectivity of the compounds towards the isoenzymes.

A small collection of 2-hydroxy-N-(5-methyl/nonsubstituted 4-oxo-2-substituted phenyl-1,3-thiazolidin-3-yl)-2-phenylacetamides (3-16) was synthesized from the cyclocondensation of 2-hydroxy-2-phenyl-N'-[(substitutedphenyl)methylene]acetohydrazides (2) and mercaptoethanoic acid or 2-mercaptopropanoic acid, characterized with spectral and elemental analysis. In order to explore their antimycobacterial potential, newly synthesized fourteen compounds were screened for their inhibitory activity against Mycobacterium tuberculosis strain H37Rv at 6.25 μg/mL with in-vitro primary tests. Compound 7 was found to provide the highest inhibition (98%) M. tuberculosis strain H37Rv, while most of the new derivatives showed different inhibition ratios. For the search of the putative targets which are considered as related to the antimycobacterial activity of these molecules, docking studies were performed. With molecular dynamic simulations, further possible interactions between ligands and the active site of the selected enzymes were investigated. Eventually, molecular modelling studies indicated that at least part of the mechanism of action of these compounds may be mediated by inhibition of MtInhA.