Interconverting flavonostilbenes with antibacterial activity from Sophora alopecuroides.

Abstract Five flavonostilbenes (alopecurones H, I, J, K and L) and five known ones were isolated from roots of Sophora alopecuroides , in addition to ten other phenolic compounds. A non-enzymatic interconversion of the lavandulyl-substituted flavonostilbenes was observed among alopecurones A, H, I, and K through a Wessely–Moser rearrangement reaction; this was proven by 1D and 2D NMR, HPLC-CD–PDA and HRMS analyses. Bioassay results suggested that flavonostilbenes exhibit significant antibacterial and anti-biofilm formation activities against Staphylococcus epidermidis with MIC values ranging from 3.1 to 12.5 μg/mL.