Five New Phenylethanoid Glycosides from the Whole Plants of Lamium purpureum L.

摘要

Five new phenylethanoid glycosides,lamiusides A (1),B (2),C (3),D (4) and E (5),were isolated from the whole plants of Lamium purpureum L.(Labiatae) together with seven known compounds (6-12).On the basis of chemical and spectral analyses,the structures of the new compounds were elucidated to be 2-(3,4-dihydroxy- phenyl)ethyl-O-beta-D-galactopyranosyl-(1->2)-alpha-L-rhamnopyranosyl-(l->3)-(4-O-trans-caffeoyl)-beta-D-glucopyra- noside (1),2-(3,4-dihydroxyphenyl)ethyl-O-beta-D-galactopyranosyl-(l->2)-alpha-L-rhamnopyranosyl-(1->3)-(4-0-trans- feruloyl)-beta-D-glucopyranoside (2),2-(3,4-dihydroxyphenyI)ethyl-0-beta-D-galactopyranosyl-(l->2)-alpha-L-rhamnopy- ranosyl-(l->3)-(6-0-trans-caffeoyl)-beta-D-gIucopyranoside (3),2-(3,4-dihydroxyphenyl)-R,S-methoxy-ethyl-O-beta-D- galactopyranosyl-(l->2)-alpha-L-rhamnopyranosyl-(l->3)-(4-0-trans-caffeoyl)-beta-D-glucopyranoside (4) and 2-(3-hy- droxy-4-methoxyphenyl)ethyl-O-alpha-L-rhamnopyranosyl-(1->3)-beta-D-glucopyranosyl-(l->6)-(4-0-cis-feruloyl)-beta-D- glucopyranoside (5).In addition,the radical-scavenging activities of compounds 1-4 on l,l-diphenyl-2-picrylhy- drazyl radical were examined.