E. Bedir et al., Cycloartane triterpene glycosides from the roots of Astragalus brachypterus and Astragalus microcephalus, J NAT PROD, 61(12), 1998, pp. 1469-1472
Three new cycloartane-type triterpene glycosides, brachyosides A (1), B (3)
, and C (2), from the roots of Astragalus brachypterus and one new glycosid
e, cyclocephaloside II (4), from the roots of Astragalus microcephalus have
been isolated together with five known saponins, astragalosides I, II, and
IV, cyclocanthoside E, and cycloastragenol. The structures of the new comp
ounds were established as 3-O-[beta-D-xylopyranosyl(1-->3)-beta-D-xylopyran
osyl-3 beta,6 alpha,24(S),25-pentahydroxycycloartane (1), 3-O-beta-D-xylopy
ranosyl-6-O-beta-D-glucopyran pentahydroxycycloartane (2), 20(R),24(S)-epox
y-6-O-beta-glucopyranosyl-3 (3), and 20(R),24(S)-epoxy-3-O-(4'-O-acetyl)-be
ta-D-16 beta,25-tetrahydroxycycloartane (4). For the structure elucidations
, 1D- and 2D-NMR experiments and FABMS were used.