Anti-inflammatory steroids from the rhizomes of Dioscorea septemloba Thunb

•Seven new steroids were isolated from the rhizomes of Dioscorea septemloba.•Some compounds displayed inhibitory activities on LPS-induced NO production.•The structure-activity relationship of steroids was summarized.

Seven new steroid glycosides, dioscorosides A1 (1), A2 (2), B1 (3), B2 (4), C1 (5), C2 (6), and D (7), together with 22 known ones (8–29) were isolated from the rhizomes of Dioscorea septemloba, their structures were elucidated by chemical and spectroscopic methods. All isolates were evaluated for in vitro anti-inflammatory potential using LPS-stimulated RAW 264.7 murine macrophages. Among them, spirostane glycosides 18 and 21–24 exhibited significant inhibition of nitrite production. Moreover, the structure-activity relationship was summarized.

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slide