A new homoisoflavone from L and its antioxidant activity.

A new compound was identified as 3-(2-hydroxybenzyl)-5,7-dimethoxy-4-chromen-4-one (or 2'-dihydroxy-5,7-dimethoxy-homoisoflavone), oleracone F (), together with -hydroxy ethyl cinnamate () and 4-hydroxy-3-methoxy ethyl cinnamate () isolated from the L. for the first time and six known compounds, salicylic acid (), -carboline-3-carboxylic acid (), aurantiamide (), portulacanone A (), B () and C () Their structures were determined using spectroscopic methods, including one- and two-dimensional nuclear magnetic resonance and high-resolution electrospray ionization time-of-flight mass spectrometry. Notably, oleracone F () presented scavenging activity in 1,1-diphenyl-2-picryl-hydrazyl (DPPH) radical quenching assay, with IC value of 17.78 μM.