Two new phenolic glycosides from the stems of Clematis parviloba

To study the chemical constituents of the stems of Clematis parviloba, six compounds were isolated from a 95% ethanol extract by using a combination of various chromatographic techniques including column chromatography over silica gel, ODS, Sephadex LH-20, and semi-preparative HPLC. Two new phenolic glycosides, 2-((E)-3-carboxybut-2-en-yl)-4-hydroxy-3-methyl-phenyl-O-beta-D-glucopyranoside (1) and 4'-hydroxy-phenol-beta-D-[6-O-(4"-hydroxy-3", 5"-dimethoxy-benzoate)] glucopyranoside (2) were isolated, together with a known phenolic glycoside, 4'-hydroxy-3'-methoxy-phenol-beta-D-[6-O-(4"-hydroxy-3", 5"-dimethoxy-benzoate)] glucopyranoside (3) as well as three known megastigmane glycosides, linarionoside A (4), linarionoside C (5), and staphylionoside K (6). Their structures were determined on the basis of spectroscopic analysis and chemical evidence. Among them, compounds 1 and 2 were named as clemaparvilosides A (1) and B (2), respectively, and compounds 3-6 were obtained from Clematis genus for the first time.