title: Two triterpenoid saponins from Pterocephalus bretschneidri.
abstract: Two new triterpenoid saponins, named bretschnosides A and B, were isolated from the roots of Pterocephalus bretschneidri. On the basis of chemical degradation and spectroscopic evidence, the structures of bretschnosides A and B were shown to be 3-O-alpha-L-rhamnopyranosyl(1-->3)- beta-D-xylopyranosyl(1-->3)-alpha-L-rhamnopyranosyl(1-->2)-beta-D- xylopyranosyl oleanolic acid 28-O-beta-D-glucopyranosyl(1-->6)-beta-D-glucopyranoside 4 and 3-O-alpha-D-glucopyranosyl(1-->3)-beta-D-xylopyranosyl(1-->3)-alpha-L- rhamnopyranosyl(1-->2)-beta-D-xylopyranosyl oleanolic acid 28-O-beta-D-glucopyranosyl(1-->6)-beta-D-glucopyranoside 6, respectively.
authors.affiliation: Chengdu Institute of Biology, Academia Sinica, China.
authors.forename: J
authors.initials: J
authors.lastname: Tian
authors.forename: F E
authors.initials: FE
authors.lastname: Wu
authors.forename: M H
authors.initials: MH
authors.lastname: Qiu
authors.forename: R L
authors.initials: RL
authors.lastname: Nie
mesh_terms: D002240:Carbohydrate Sequence; D009682:Magnetic Resonance Spectroscopy; D008969:Molecular Sequence Data; D015394:Molecular Structure; D009828:Oleanolic Acid / Q000031:analogs & derivatives*; D010946:Plants, Medicinal / Q000737:chemistry*; D012503:Saponins / Q000737:chemistry / Q000302:isolation & purification*; D014315:Triterpenes / Q000737:chemistry / Q000302:isolation & purification*
chemical_list: D012503:Saponins; D014315:Triterpenes; C080843:bretschnoside A; C080846:bretschnoside B; D009828:Oleanolic Acid