Bioactive Cycloartane-Type Triterpene Glycosides from Astragalus elongatus

摘要

Together with two known cycloartane-type glycosides, askendosides D (3-O-[α-arabinopyranosyl-(1→2)-β-xylopyranosyl]-6-O-β-xylopyranosyl-cycloastragenol, 2) and G (3-0- [aarabinopyranosyl-( 1→2)-β-xylopyranosyl]-16-O-β-glucopyranosy1-3β,6α,16β,24(R),25- pentahydroxycycloartane, 3), also a new monodesmosidic cycloartane-type glycoside, elongatoside (1), was isolated from the roots of Astragalus elongatus and identified as 3-0- [aarabinopyranosy1-(1→2)-β-xylopyranosyl]-cycloastragenol. All structures were unambiguously determined by means of spectroscopic and spectrometric methods (1D and 2D NMR, ESI-MS). The isolated compounds were tested for the inhibition of proliferation and ICAM-1 expression in vitro using the human microvascular endothelial cell line (HMEC-1). 1 showed weak activity in the ICAM-1 assay.