Abstract
Metal complexes derived from salicylaldehyde-based Schiff bases are among the frontrunners in the pursuit of precise and potent cancer treatments due to their remarkable prowess. In this study, salicylaldehyde-based Schiff base (HL) was prepared via a reaction between 2-amino-5-benzonitrile and salicylaldehyde. Subsequently, HL was further reacted with Ni (II), Co (II), Cu (II) and Pd (II) ions using their respective metal salts to obtain homoleptic mononuclear complexes (C1-C4). The composition of HL and C1-C4 were determined using 1H and 13C NMR, UV-Vis, FTIR, CHN, SEM-EDX and HRMS analyses. In addition, the structural geometries of HL, C1, C3 and C4 were determined in solid state using single crystal X-ray diffraction analysis and corroborate with the mentioned characterization techniques employed. The stability of compounds was assessed through time-dependent UV-vis spectroscopy, revealing that C2 exhibited the highest stability under the experimental conditions. Subsequently, the anticancer effects of HL and C2 were tested on breast cancer cell lines (MCF-7) using MTT, LDH and ATP assays. Both HL and C2 displayed potential cytotoxicity on the MCF-7 cell line, in which C2 displayed a better inhibition effect than a standard chemotherapeutic agent, doxorubicin (DOX), with IC50 of 43.08 mu M. We postulate that the mechanism by which C2 may function is by binding to DNA (Ka$$ {K}_a $$ = 0.114 (+/- 0.02) x 104) and intercalation (shown by UV-CD and UV-LD spectroscopy) at the AT rich sites. These data were corroborated in silico by extra precision (XP) docking and molecular dynamic (MD) simulations.