Synthesis, characterization, biological studies, molecular docking and theoretical calculation of some transition metal complexes with new azo dye 2-[2′-(6-methoxybenzothiazolyl)azo]-3-methyl-4-nitrophenol

Abstract

Ag(I), Pt(IV), and Au(III) metal complexes of novel ligand 2-[2′-(6-methoxybenzothiazolyl)azo]-3-methyl-4-nitro phenol (6-MBTAMN) have been synthesized and characterized by 1H NMR, 13C NMR, FT-IR, UV–vis, Mass spectra, CHNS, atomic absorption spectrophotometry, molar conductance and magnetic susceptibility. Results confirmed that the ligand coordinates the metal ion to form a mononuclear complex via (N, N, O) atoms of the azomethine group, azo group, and phenolic group, respectively. Tetrahedral geometry is suggested for Ag(I)-Complex, an octahedral geometry is proposed for Pt(IV)-Complex, and a square planar geometry is suggested for Au(III)-Complex. The density functional theory (DFT) was used to calculate significant parameters for ligand and metal complexes, including optimization energy, HOMO, and LUMO. Newly synthesized azo compounds have also been demonstrated to have antimicrobial properties against bacteria and fungi. The complexes are more effective against bacteria than standard antimicrobials (Novobiocin and Cycloheximide), but less effective against fungi. Based on in silico molecular docking, the study demonstrated that the azo fused compounds interact critically with the androgen receptor prostate cancer mutant H874Y ligand binding domain bound with testosterone and an AR 20–30 peptide (ART) using the Molecular Operating Environment module (MOE). Further, the antioxidant activity of novel azo compounds was evaluated using DPPH radical scavenging, which demonstrated that Ag (I) metal complex possess potent antioxidant properties. The cytotoxic abilities of selected compounds by MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] assays against PC3 (human prostate adenocarcinoma) and HUVECs (normal human umbilical vein endothelial cells).