Pentacyclic Triterpenoid Saponins from Silene viscidula

Three new pentacyclic triterpenoid saponins, viscidulosides A and B (1 and 2, resp.), and silenoviscoside D (3), were isolated from the roots of Silens viscidula, together with two known saponins, sinocrassulosides VIII and IX (4 and 5, resp.). Their structures were elucidated by spectroscopic data and chemical methods. Compounds 112 and 4/5 were two inseparable mixtures, which are glycosides of quillaic acid whose fucose residue is acylated by (E)- or (Z)-4-methoxycinnamic acid.