C₂₁ steroidal glycosides from the root bark of <i>Periploca sepium</i> and their NO production inhibitory and cytotoxic activity

A series of C21 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 C21 steroidal glycosides could remarkably inhibit NO production, particularly 1 and 2 with IC50 values of 30.81 ± 0.18 μM and 44.39 ± 0.21 μM, 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 IC50 values of 28.41 ± 0.12 μM and 39.06 ± 0.05 μM, respectively.