Synthesis, Characterization, and Biological Evaluation of Osmium(IV) Pyrazole Carbothioamide Complexes.

Osmium(IV) pyrazole carbothioamide complexes with different substituted pyrazole carbothioamide heterocyclic ligands have been synthesized and characterized. The ligands have been characterized using 1H-NMR, 13C-APT, LC-MS, elemental analysis, and IR spectroscopy. Whereas, osmium(IV) compounds have been characterized using ESI-MS, ICP-OES, IR spectroscopy, magnetic, and conductance measurements. The compounds have been evaluated for various biological activities. The binding constant of ligands and complexes have been found in the range of 1.2–3.6 × 104 and 1.2–6.8 × 104 M−1, respectively. The docking energy values of complexes have been found in the range of −286.28 to −326.49 kJ/mol. The Ksv and Kf values of Os(IV) compounds evaluated using fluorescence quenching activity have been found in the range of 4.7–9.2 × 103 and 1.3–7.6 × 103 M−1, respectively. The minimum inhibitory concentration of osmium(IV) compounds and ligands have been found in the range of 50–75 µM and 120–135 µM, respectively. The LC50 values evaluated using brine shrimp lethality assay of osmium(IV) compounds and ligands have been found in a range of 7.52–16.12 µg/mL and 15.80–20.03 µg/mL, respectively. [ABSTRACT FROM AUTHOR]