Synthesis and Antioxidant Activity of some novel 4H-Chromene Derivatives Catalysed by Biogenic Tin Oxide Nanoparticles
Unknown authors
Abstract
The present study reports an eco-friendly and biogenic synthesis of Tin Oxide Nanoparticles (SnO2 NPs) using aqueous sunflower leaf extract. The synthesized SnO2 NPs were characterized using advanced analytical techniques such as X-day diffraction spectroscopy, UV-Visible spectroscopy, FT-IR spectroscopy, and Electron Microscopy. After observing the formation of SnO2 NPs by UV-Vis spectroscopy, the crystalline nature of SnO2 NPs was confirmed by powder XRD analysis. Fourier Transform Infrared Spectroscopy (FT-IR) analysis was used to check the attached functional groups on the surface of SnO2 NPs due to the capping of phytochemicals during the reduction and stabilization of NPs by the plant's secondary metabolites. Size, crystallinity, and morphology were measured by High-resolution transmission electron microscopy (HR-TEM) analysis. The prepared SnO2 NPs were used as a catalyst for synthesizing the novel 4H-chromene compounds via a multicomponent reaction of salisaldehydes, acetylacetone, and 4-Hydroxy coumarin by microwave method. All the compounds were characterized by 1H and 13C NMR spectroscopy. All the compounds and SnO2 NPs were further screened for antioxidant activity using DPPH radical assay. All compounds showed a good percentage of inhibition with respect to standard ascorbic acid.