C 21 steroidal glycosides from the root bark of Periploca sepium and their NO production inhibitory and cytotoxic activity.

A series of C ₂₁ steroidal glycosides were isolated from the root bark of Periploca sepium , including a new compound, perisepiumoside A1 ( 1 ), and six known compounds ( 2-7 ). Their structures were elucidated by analysis of HR-ESI-MS, and 1D and 2D NMR spectroscopic data. All these compounds were tested for their NO production inhibitory activity in LPS-stimulated RAW 264.7 cells. Results showed that these C ₂₁ steroidal glycosides could remarkably inhibit NO production, particularly 1 and 2 with IC ₅₀ values of 30.81 ± 0.18  μ M and 44.39 ± 0.21  μ M, respectively. In addition, the cytotoxicity of these compounds was measured on A549, MCF-7, and HeLa cancer cell lines. Among them, compounds 1 and 7 displayed cytotoxicity against the A549 cell line with IC ₅₀ values of 28.41 ± 0.12  μ M and 39.06 ± 0.05  μ M, respectively.