Isolation and identification of the phenolic compounds from the roots of Sanguisorba officinalis L. and their antioxidant activities.

Four phenolic compounds were isolated from the roots of Sanguisorba officinalis L. by silica gel column chromatography and preparative HPLC. On the basis of chemical and spectroscopic methods, their structures were identified as methyl 4-O-β-D-glucopyranosy-5-hydroxy-3-methoxylbenzoate (1), 3,3′,4′-tri-O-methylellagic acid (2), fisetinidol-(4α-8)-catechin (3), and (+)-catechin (4). Compound 1 is a new phenolic glycoside and compounds 2 and 3 were isolated from the Sanguisorba genus for the first time. Compounds 1–4 were also assayed for their antioxidant activities using the DPPH free radical assay.