Inhibitory activity of flavonoids fraction from Astragalus membranaceus Fisch. ex Bunge stems and leaves on Bacillus cereus and its separation and purification

Introduction: Astragalus membranaceus Fisch. ex Bunge is a traditional botanical drug with antibacterial, antioxidant, antiviral, and other biological activities. In the process of industrialization A. , most aboveground stems leaves are discarded without resource utilization except for small amount low-value applications such as composting. This study explored antibacterial activity stem leaf extracts to evaluate its potential feed antibiotic substitute. Materials methods: The flavonoid, saponin, polysaccharide fractions in was evaluated by disk diffusion method. inhibitory flavonoid fraction from on B. cereus aspects growth curve, cell wall, membrane, biofilm, bacterial protein, virulence factors. On this basis, were isolated purified column chromatography determine main components. Results: had significant against minimum concentration (MIC) bactericidal (MBC) 1.5625 6.25 mg/mL, respectively. can induce death many ways, inhibiting growth, destroying wall membrane integrity, biofilm formation, protein synthesis, downregulating factor expression. addition, it clear that isoliquiritigenin. Molecular docking showed isoliquiritigenin could form hydrogen bonding force FtsZ. Conclusion: chemical composition