Abstract:This work aimed to study the antibacterial activities of crude and refined extracts of total flavonoids from tartary buckwheat bran on pathogenic bacteria, to analyze the flavonoid monomer components and evaluate the antibacterial activity of different flavonoid glycosides. The antibacterial activity of crude and refined total flavonoids and their four flavonoid glycosides was investigated by the diffusion plate method and double dilution method. Qualitative and quantitative determination of total flavonoids in tartary buckwheat bran were detected by high-performance liquid chromatography (HPLC). The refined extract of tartary buckwheat bran had stronger antibacterial activity on Staphylococcus aureus, Micrococcus luteus, Enterococcus, Escherichia coli, Shigella, and Salmonella than the crude extract. The main flavonoids of tartary buckwheat bran were rutin, kaempferol-3-O-rutin, quercetin and kaempferol. The total flavonoid content of refined extract was 2.84 times that of the crude extract. The antibacterial activities of four flavonoid monomers showed a certain structure-activity relationship. Among them, quercetin showed good antibacterial activity against all tested bacteria.
