Spectroscopic studies, quantum chemical investigations, and in silico and in vitro scrutiny of the diuretic drug trichlormethiazide adsorbed on AuNPs.

Experimental and theoretical study was employed to study the adsorption of the diuretic drug, trichlormethiazide (TCM) molecule on AuNPs (TCMA). The stereoelectronic properties of the molecular structure of most stable conformers of TCM and TCMA were studied using DFT/B3LYP-6-311++G (d, p) together with LANL2DZ methodology. The Fourier transform Raman and Infrared spectra of TCM were recorded and analyzed. Quantum chemical calculations of TCM and TCMA molecules were used to evaluate the stability of the molecule, hyper-conjugative interactions, electron delocalization, and binding interactions. The calculated and experimentally observed vibrational frequencies of the molecule were assigned and compared. The shifting and intensity enhancement of the CCl2 band manifests the back-donation and conjugation effect, which are the result of the presence of nitrogen atom adjoining the dichloromethyl groups and the oxygen in the sulfur dioxide group attached among the amino group and the chlorophenyl ring, respectively, which enhances bioactivity. Anticancer activity was examined based on molecular docking analysis, and it was identified that TCM and TCMA molecules act as good inhibitors against lung cancer. SERS analysis and MTT assay confirmed the molecular docking analysis results.