Antioxidative phenylpropanoid-substituted epicatechin glycosides from Parabarium huaitingii

Three new phenylpropanoid-substituted epicatechin glycosides, namely parabarosides A - C ( 1- 3), together with three known compounds, 5-caffeoylquinic acid (4), 5-caffeoylshikimic acid (5), and 3,4-dicaffeoylquinic acid (6), were obtained from the plant Parabarium huaitingii. Their structures were determined and full assignments of (1)H- and (13)C-NMR spectroscopic data were achieved by analyses of 1D- and 2D-NMR, mass, and CD spectra. The oxygen radical absorbance capacity (ORAC) assay was applied to evaluate their antioxidative capacity in vitro, which revealed that 1- 6 showed strong antioxidative properties.