Study on lignan constituents from aerial part of Rubia cordifolia / 中草药

ABSTRACT

Objective To investigate the chemical constituents of the aerial part of Rubia cordifolia. Methods All compounds were isolated and purified by silica gel, Sephadex LH-20, and MCI column chromatography. Their structures were determined by physicochemical properties and spectral data. Results Eleven compounds were isolated and identified as (-)-episyringaresinol (1), (-)-secoisolariciresinol (2), (-)-3,4-divanillyl tetrahydrofuran (3), lignans (+)-demethoxypinoresinol (4), (+)-syringaresinol (5), (+)-isolariciresinol (6), burselignan (7), (7S,8R)-dihydrodehydroconiferyl alcohol (8), 4,5'-dimethoxy-lariciresinol (9), (+)-7R,8S-5- methoxydihydrodehydroconifery alcohol (10), and 5,5'-dimethoxy-7-oxolariciresinol (11). Conclusion All compounds are isolated from this plant for the first time.