Anticancer, Antihaemolytic and Anticoagulant Studies of Coumarin-Substituted Sterically Tuned N-Heterocyclic Carbene Silver(I) Complexes

Abstract

A series of sterically varied silver-based N-heterocyclic carbene (NHC) complexes (14–17) were synthesized by embroidering biomedically active coumarin and 1,2,4-triazole core as NHC precursors (10–13). The structure of all the synthesized salts (10–13) and complexes (14–17) were elucidated by FT-IR and NMR (proton and carbon) spectroscopic techniques. Complex 15 was characterized by single-crystal x-ray diffraction. The data obtained from this characterization of the small molecule 15 confirmed the three-dimensional arrangement of the complex. This also indicated agostic-type interactions between the Ag atom and the CH modules of one of the NHC ligands. Further, the synthesized complexes (14–17) were studied for the antihaemolytic, anticoagulant and anticancer activities. The complexes 15 and 17 exhibited anticoagulant properties comparable to that of the standard anticoagulant EDTA. Notably, all the complexes evidenced anticancer activity on leukaemic cell lines (K562) with the IC₅₀ values below 100 μM, the concentration at which antihaemolytic property was evidenced. Complex 15 exhibited the lowest IC₅₀ value of 18.44 ± 0.76 μM, which could be attributed by the appropriate steric bulk around the metal atom. The cumulative data of the three analyses validate potential of the complexes 15 and 17 to exhibit antihaemolytic, anticancer and anticoagulant properties.