Abstract
Recently, Au(III) complexes are being drafted with greater interest as potential new metal-based medications. Even though Au(I) compounds are widely recognized and utilized in modern medicine, novel Au(III) complexes and ligands with different donor atoms are being prodeced and examined for their biological (antimicrobial, antitumor) activities. The anthocyanin molecule gives preferential coordination reaction with Au(III) ion. Herein, we reported an efficient synthesis and characterization of anthocyanine containing Au(III) nanocomplex. The structure of synthesized water-soluble anthociyanin–Au(III) nanocomplex (AcAuNPs) was characterized using Ultraviolet-visible spectroscopy (UV-vis), Fourier-transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), Quadrupole Time-of-Flight (QTOF) Mass Spectrometry (MS), and dynamic light scattering (DLS). SEM images proved that the AcAuNPs were in spherical form with sizes ranging from 10 to 13 nm. The result of DLS analysis showed that the average particle size synthesized at reflux temperature was 140 nm in diameter, and at room temperature was 560 nm, and AcAuNPs had monodisperse systems (polydispersity index, 0.478 and 0.301 at reflux and room temperatures, respectively). The anthocyanin ligand forms the Au(III) coordination compound in a bidentate, square planner geometry with two oxygen donor atoms (ligand/metal:1/1). AcAuNPs synthesised at reflux and room temperatures have strong inhibition against both E. coli and S. aureus (respectively 16, 19 and 14,17 mm) bacterial strains. We suggest that AcAuNPs can be used as the antibacterial agent. AcAuNPs had significant ability or react with free radicals to make them stable and could work as natural antioxidants to eliminate harmful free radicals produced by normal cellular functions.