Glycosides from Cephalaria Species

Abstract

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-[β -D-glucopyranosyl( 1→3)-α-L-rhamnopyranosyl(1→4)-β -D-xylopyranosyl(1→4)-β -D-xylopyranosyl]-28-O-[β -Dglucopyranosyl( 1→6)-β -D-glucopyranosyl]-oleanolic acid (1), 3-O-[β -D-xylopyranosyl(1→3)-α- L-rhamnopyranosyl(1→4)-β -D-xylopyranosyl]-28-O-[β -D-glucopyranosyl]-oleanolic acid (2) from Cephalaria lycica Matthew and 3-O-{β -D-glucopyranosyl(1→4)-β -D-xylopyranosyl(1→3)-α-Lrhamnopyranosyl( 1→2)-[β -D-glucopyranosyl(1→3)]-α -L-rhamnopyranosyl}-28-O-[β -D-glucopyranosyl( 1→6)-β -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.