Trojanosides I-K:: New cycloartane-type glycosides from the aerial parts of Astragalus trojanus

Three new cycloartane-type triterpene glycosides have been isolated from the aerial parts of Astragalus trojanus. The structures were established mainly by a combination of one- and two-dimensional NMR techniques [H-1-H-1-correlation spectroscopy (COSY), H-1-C-13-heteronuclear multiple quantum correlation spectroscopy (HMQC), and H-1-C-13-heteronuclear multiple-bond correlation spectroscopy (HMBC)] and high resolution electrospray ionization mass spectrometry (HR-ESI-MS) as 3-O-beta-(2',3'-di-O-acetyl)-D-xylopyranosyl-6-O-beta -D-glucopyranosyl-16-O-acetoxy-20(R),24(S)-epoxycycloartane-3 beta ,6 alpha ,16 beta ,25-tetrol, 3-O-[alpha -L-rhamnopyranosyl-(1 -->2)beta-(3',4'-di-O-acetyl)-D-xylopyranosyl]-6-O-beta -D-xylop'ranosyl-20(R),24(S)-epox3-cycloai-tane-3p,6a,16P,25-tetrol, 3-O-beta -D-xylopyranosyl-6,16-di-O-beta -D-glucopyranosyl-20(R),24(S)-epoxycycloartane-3 beta ,6 alpha ,16 beta ,25-tetrol.