Saponins from roots of Platycodon grandiflorum. Part 1. Structure of prosapogenins

Seven new prosapogenins have been isolated as their methyl esters [(1), (2), and (4)–(8)] from the roots of Platycodon grandiflorum A. DC., along with the known 3-O-β-D-glucopyranosylplatycodigenin methyl ester (3). The structures of the seven compounds were elucidated using 13C and 1H n.m.r. spectroscopy.