Palladium(II) complexes of 5-substituted isatin thiosemicarbazones: Synthesis, spectroscopic characterization, biological evaluation and in silico docking studies

Substituted heterocyclic (isatin) appended thiosemicarbazone ligands (L1-L3) are synthesized by condensation of substituted isatin molecule with N(4)-phenyl-3-thiosemicarbazide in good yields. The palladium(II) complexes are synthesized from ligands (L1-L3) and PdCl2, with a general formula [PdCl(X-C15H10N4OS)] where X = 5-chloro (1), 5-bromo (2), and 5-nitro (3). Both analytical and spectroscopic methods have been used for the analysis and characterization of the synthesized compounds. The antimicrobial activity results observed that complexes, 1 and 2 have registered potent antibacterial activity against B. subtilis and K. pneumoniae and also complex 2 has shown good antifungal activity against the micro organisms. The antioxidant activity analysis revealed that the complex 3 showed significant activity with IC50 values 7.24 +/- 0.09 mu M. Moreover, the in vitro antiproliferative activity results suggested that complex 3 exhibited high activity against HeLa cell line compared with the standard with the IC50 value 16.52 +/- 1.08 mu M. The docking results correlate well. [GRAPHICS]