Sesquiterpene lactones in mongolian Saussurea lipshitzii

Abstract

Five known guaianolides were isolated from the areal part of Saussurea lipshitzii ( Asteraceae ) collected in South Gobi, Mongolia: cynaropicrin ( I ), janerin ( II ), chlorojanerin ( III ), 15-deschloro-15-acetoxychlorojanerin ( IV ), and 15-deschloro-15-hydroxychlorojanerin ( V ). The correlation between I-V and the β-configuration of the C-4/C-15 bond in II-V was shown by biomimetic chemical transformations, suggesting compound I as the possible common precursor. (