Evaluation of natural prenylflavonoids from Sophora flavescens root bark and their antibacterial activity

10 compounds (1-10) were isolated from the ethanol extract of Sophora flavescens root bark, including 7 new compounds (1-7). The structures of these compounds were determined through comprehensive spectroscopic analyses, including UV spectroscopy, high-resolution electrospray ionization mass spectrometry (HRESIMS), and nuclear magnetic resonance (NMR), and by comparison with existing literature. Additionally, the antibacterial activity of compounds 1-10 was assessed against eight bacterial strains (four Gram-positive and four Gram-negative) using the micro broth dilution method. Among these, eight compounds exhibited significant antibacterial activity against Gram-positive bacteria. Mechanistic studies demonstrate that compound 1 exhibits enhanced membrane-targeting activity by selectively binding to key bacterial cell membrane components-phosphatidylglycerol (PG), phosphatidylethanolamine (PE), and cardiolipin (CL).