Isolation and identification of three new phenylpropanoids from the culms of phyllostachys nigra var. henonis (mitford) Rendle

Three new phenylpropanoids, namely (7′R,8′R) guaiacylglycerol 4′-O-β-D-[6″-O-(4-O-β-D-glucopyranosyl)-p-hydroxyl­benzoyl]-glucopyranoside (1), (7 R,8R) guaiacylglycerol 8-O-1′-(2′,6′-dimethoxy-4′-O-β-D-glucopyranosyl)-benzene (2), (7′R,8′R) guaiacylglycerol 4′-O-β-D-[6″-O-3,5-dimethoxy-4-hydroxylbenzoyl]-gluco­pyranoside (3), along with one known phenylpropanoid (4) were isolated from the ethanol extract of Phyllostachys nigra var. henonis fresh culm. The structures of all compounds were determined by analysis of UV, 1D NMR, 2D NMR, HR-ESI-MS and CD data. All compounds were evaluated for their DPPH radical scavenging activity. Compound 2 (IC50 54.9 μM) and 3 (IC50 77.2 μM) exhibited moderate antioxidant activity compared with two positive control compounds L-ascorbic acid (IC50 15.5 μM) and 2,6-ditertbutyl-4-methyl phenol (IC50 19.1 μM).