Diarylheptanoid glycosides from Dioscorea nipponica rhizomes.

A group of previously undescribed diarylheptanoids with mono/di-glucose substitution, diodiarylheptosides A–F (1 – 6), together with six known diarylheptanoids (7 – 12) were isolated from the rhizomes of Dioscorea nipponica. Their structures were established by comprehensive UV, IR, HR-ESI-MS and NMR analyses, and their absolute configurations were determined by a comparison of calculated and experimental ECD, some with optical rotations, after acid-hydrolysis. Moreover, bioassay results showed that compounds 3 and 11 exhibited stronger NO inhibitions on lipopolysaccharides-induced RAW 264.7 cells, with the IC 50 values of 14.91 ± 0.62 and 12.78 ± 1.12 μM. [Display omitted] • Diodiarylheptosides A–F (1–6), a group of rare natural diarylheptanoids with mono/di-glucose substitution, were isolated from Dioscorea nipponica rhizomes. • Their absolute configurations were determined by a comparison of calculated and experimental ECD, some with optical rotations, after acid-hydrolysis. • Compounds 3 and 11 showed stronger NO inhibitions on LPS-induced RAW 264.7 cells. [ABSTRACT FROM AUTHOR]