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

Abstract

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 K_sv and K_f 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.

Graphical Abstract

Keywords:

• Osmium(IV) pyrazole carbothioamide complexes
• HS-DNA
• molecular docking
• A-549 cell line

Acknowledgments

The authors thanks to the Head, Department of Chemistry, Sardar Patel University, Vallabh Vidyanagar, Gujarat, India, for providing the laboratory facilities. The authors are also thankful for UGC-CPEPA and UGC-CAS program running in the institute.

Disclosure statement

There are no conflicts of interest.

Additional information

Funding

The authors thank UGC, New Delhi, for providing financial assistance of UGC BSR Grant no. C/2015/BSR/Chemistry/1579.