Three new caffeoyl glycosides from the roots of Picrorhiza scrophulariiflora

From the underground parts of Picrorhiza scrophulariiflora, three new caffeoyl glycosides, scrocaffeside A-C (1-3), together with two caffeic acid derivates, 4-O-beta-D-glucopyranosyl caffeic acid (4) and 4-methoxy caffeic acid (5) and a phenylethanoid glycoside, scroside D (6), were isolated. Their structures were elucidated on the basis of chemical and spectroscopic evidence and comparisons with literature data of related compounds.