Three new glycosides from the whole plant of Clematis lasiandra Maxim and their cytotoxicity

Phytochemical investigation on the whole plant of Clematis lasiandra Maxim led to the isolation of two new phenolic glycosides (1 and 2), one new lignanoid glycoside (3), together with three known lignanoid glycosides (4-6). The structures of the new compounds were elucidated as 4-O-beta-D-galactopyranosylethyl-E-caffeate (1), 4-O-beta-D-galactopyranosyl-3-hydroxyl-phenylethene (2) and (8R)-3,3'-dimethoxy-4,4',9,9'-tetrahydroxy-5',8-lignan 3'-O-beta-D-glucopyranoside (3), on the basis of extensive spectral analysis and chemical evidence. The characteristic of the polymerized C-5'-C-8 type lignanoid aglycone in glycoside 3 was found from genus Clematis for the first time. Compounds 1-6 were evaluated for their cytotoxicity against human tumor cell lines HL-60, Hep-G2 and SGC-7901, the new glycosides 1 and 2 showed significant cytotoxicity against those three tumor cell lines with IC50 in the range from 9.73 to 22.31 mu M, while lignanoid glycosides 3-6 showed weak cytotoxicity to those test cell lines with IC50 value more than 52.71 mu M. (C) 2014 Phytochemical Society of Europe. Published by Elsevier B.V. All rights reserved.