Synthesis, structural interpretation, DFT, molecular docking, antimicrobial assessment and cytotoxic profiling of a cadmium(II) hydroxamate complex: in vitro and in silico investigations

Abstract

A Cd(II) complex of composition Cd(C11H9CONHO)2 has been synthesized by treating CdCl2 (anhydrous) with potassium 1-naphthaleneacetohydroxamate (C11H9CONHOK) (KHL) in 1:2 molar ratio in MeOH. Various physicochemical studies including elemental analysis, molar conductivity, FTIR, UV-visible,1H and 13C NMR spectroscopic techniques were employed to interpret the structure of the complex. O,O-Coordination has been proposed through the carbonyl and hydroxamic oxygen atoms and a distorted tetrahedral geometry around cadmium is supported by physicochemical and computational studies. Density Functional Theory studies have shown the stability of the complex and predict various structural parameters (bond lengths and angles). Chemical reactivity descriptors and Mulliken charge analysis were also calculated and analyzed. Molecular docking studies were conducted to analyze the interaction of the ligand and complex with two proteins, Escherichia coli Tem1 beta-lactamase (PDB ID = 1BTL) and Alternaria alternata major allergen alt a 1 (PDB ID = 4AUD). Further, the ligand and complex were tested in vitro for their antimicrobial activity against selected microbes such as S. aureus, S. typhi, E. coli, S. flexneri, Rhizoctonia solani, Alternaria alternata, and Fusarium Sambucinum. The complex was more effective against A. alternata, showing inhibition specifically against S. typhi and E. coli. In vitro cytotoxicity studies were conducted on Rhabdomyosarcoma RD cancer cell lines. The results revealed a reduction in cell viability, correlating with increasing concentrations of the compounds, thereby indicating efficient cytotoxic activity.