Glycosides from Cephalaria Species

Three novel triterpene glycosides (1-3), namely lycicoside I, II and cilicicoside I, were isolated from two different Cephalaria (Dipsacaceae) species along with one known oleanane- and one iridoit-type of glycoside. The structures of these compounds were established as 3-O-[beta-D-glucopyranosyl(1 -> 3)-alpha-L-rhamnopyranosyl(1 -> 4)-beta-D-xylopyranosyl(1 -> 4)-beta-D-xylopyranosyl]-28-O-[beta-D-glucopyranosyl(1 -> 6)-beta-D-glucopyranosyl]-oleanolic acid (1), 3-O-[beta-D-xylopyranosyl(1 -> 3)-alpha-L-rhamnopyranosyl(1 -> 4)-beta-D-xylopyranosyl]-28-O-[beta-D-glucopyranosyl]-oleanolic acid (2) from Cephalaria lyciea Matthew and 3-O-{beta-D-glucopyranosyl(1 -> 4)-beta-D-xylopyranosyl(1 -> 3)-alpha-L-rhamnopyranosyl(1 -> 2)-[beta-D-glucopyranosyl (1 -> 3)] - alpha-L-rhamnopyranosyl}-28-O-[beta-D-glucopyranosyl(1 -> 6)-beta-D-glucopyranosyl]-hederagenin (3) from Cephalaria cilicica Boiss. & Kotschy, on the basis of spectroscopic methods (1D and 2D NMR techniques, mass spectrometry) and chemical evidence. In addition, three new prosapogenins, 1B-3B, were obtained from the basic hydrolysis of 1-3. The antimicrobial activity of 1-3 was tested against some Gram-positive and Gram-negative bacteria strains.