Two new glycosides and one new neolignan from the roots of Cynanchum stauntonii

Three new compounds including one C-21-steroidal glycoside, one methylglycoside, and one neolignan, named as Deoxyamplexicogenin A-3-O-yl-4-O-(4-O-alpha-L-cymaropyranosoyl-beta-nu-digitoxopyranosoyl)-beta- D-canaropyranoside (1), Methyl-O-alpha-L-cymaropyranosoyl-(1 -> 4)-beta-D-digitoxopyranoside (2), and (+)-(7S, 8R, 7'E)-5-hydroxy-3, 5'-dimethoxy-4', 7-epoxy-8, 3'-neolign-7'-ene-9, 9'-diol 9'-ethyl ether (3), respectively, were isolated from the roots of Cynanchum stauntonii. The structure elucidations were achieved by in-depth spectroscopic examination, mainly including the experiments and analyses of multiple 1D- and 2D-NMR and HRESIMS and CD analysis and qualitative chemical tests. Cytotoxicity activities of compounds 1-3 were evaluated against five tumor cell lines (HCT-8, Bel-7402, BGC-823, A549, and A2780) in cell based assays where they were found to be inactive. (C) 2015 Phytochemical Society of Europe. Published by Elsevier B.V. All rights reserved.