Anti-inflammatory steroids from the rhizomes of Dioscorea septemloba Thunb.

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.