title: Novel furostanol glycosides from Allium macrostemon.
abstract: Further studies by means of preparative HPLC led to the isolation of two new furostanol saponins, macrostemonosides G (1) and I (3), along with an artifact, macrostemonoside H (2) from the bulbs of Allium macrostemon Bunge. On the basis of chemical evidence and spectral analyses (1H-,13C-NMR,1H-1H COSY,1H-13C COSY, HMBC and FAB-MS), the structure of 1 was established as 26-O-beta-D-glucopyranosyl-22-hydroxy-5 beta-furost-25(27)-ene-3 beta,12 beta,26 triol 3-O-beta-D-glucopyranosyl(1-->2)-beta-D-galactopyranoside and 2 as the 22-methoxy derivative of 1; 3 was deduced to be 26-O-beta-D-glucopyranosyl-22-hydroxy-5 beta-furost-25(27)-ene-12-one-3 beta,26- diol 3-O-beta-D-glucopyranosyl(1-->2)-beta-D-galactopyranoside. Preliminary pharmacological tests showed that macrostemonoside G (1) could inhibit ADP-induced human platelet aggregation in vitro (IC50 = 0.871 mM).
authors.affiliation: Department of Phytochemistry, Shenyang College of Pharmacy, People's Republic of China.
authors.forename: J
authors.initials: J
authors.lastname: Peng
authors.forename: X
authors.initials: X
authors.lastname: Yao
authors.forename: H
authors.initials: H
authors.lastname: Kobayashi
authors.forename: C
authors.initials: C
authors.lastname: Ma
mesh_terms: D000328:Adult; D000490:Allium / Q000737:chemistry*; D002240:Carbohydrate Sequence; D002849:Chromatography, Gas; D002851:Chromatography, High Pressure Liquid; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D008969:Molecular Sequence Data; D010840:Phytosterols / Q000302:isolation & purification* / Q000494:pharmacology; D010974:Platelet Aggregation / Q000187:drug effects*; D010975:Platelet Aggregation Inhibitors / Q000302:isolation & purification / Q000494:pharmacology; D012503:Saponins / Q000302:isolation & purification* / Q000494:pharmacology; D016339:Spectrometry, Mass, Fast Atom Bombardment
chemical_list: D010840:Phytosterols; D010975:Platelet Aggregation Inhibitors; D012503:Saponins