Chemical constituents of tannin from roots of Rheum palmatum / 中草药

Objective: To study the chemical constituents of tannin from the roots of Rheum palmatum. Methods: Chemical constituents of tannins were isolated by silica gel column chromatography, medium pressure column chromatography, and semi-preparative HPLC from the roots of R. palmatum. The structures were elucidated on the basis of spectral data analysis. Results: Four tannins, 3-O-cinnamoyl-1-O-galloyl-β-D-glucopyranoside (1), 2-O-cinnamoyl-1-O-galloyl-β-D-glucopyranoside (2), 2-O-cinnamoyl-1,6-di-O-galloyl-β-D-glucopyranoside (3), and 6-O-cinnamoyl-1-O-galloyl-β-D-glucopyranoside (4) were isolated from the roots of R. palmatum. Conclusion: Compound 1 is a new compound named palmatoside.