title: Echinocystic acid 3,16-O-bisglycosides from Albizia procera.
abstract: Three triterpene glycosides and two known ones were isolated from the bark of Albizia procera by using chromatographic techniques. The structures of the compounds were determined to be 3-O-beta-D-xylopyranosyl-(1-->2)-beta-D-galactopyranosyl-(1-->6)-2-acetamido-2-deoxy-beta-D-glucopyranosyl echinocystic acid 16-O-beta-D-glucopyranoside, 3-O-beta-D-xylopyranosyl-(1-->2)-alpha-L-arabinopyranosyl-(1-->6)-2-acetamido-2-deoxy-beta-D-glucopyranosyl echinocystic acid 16-O-beta-D-glucopyranoside and 3-O-alpha-L-arabinopyranosyl-(1-->2)-alpha-L-arabinopyranosyl-(1-->6)-2-acetamido-2-deoxy-beta-D-glucopyranosyl echinocystic acid 16-O-beta-D-glucopyranoside. Their structures were determined by NMR techniques including HOHAHA, (1)H-(1)H COSY, ROE, HMQC and HMBC experiments together with FABMS as well as acid hydrolysis. To the best of our knowledge, the new compounds are considered the first examples of echinocystic acid 3,16-O-bisglycosides. In contrast to other cytotoxic echinocystic acid glycosides with N-acetyl glucosamine unit, the new glycosides were found inactive when assayed by MTT method for their cytotoxicities against the human tumor cell lines HEPG2, A549, HT29 and MCF7. The results showed the importance of the free hydroxyl group at the aglycone C-16 for exhibiting cytotoxic properties.
authors.affiliation: School of Pharmaceutical Sciences, University of Shizuoka, Shizuoka 422-8526, Japan.
authors.forename: Toshio
authors.initials: T
authors.lastname: Miyase
authors.forename: F R
authors.initials: FR
authors.lastname: Melek
authors.forename: N S
authors.initials: NS
authors.lastname: Ghaly
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Warashina
authors.forename: M
authors.initials: M
authors.lastname: El-Kady
authors.forename: Marian
authors.initials: M
authors.lastname: Nabil
mesh_terms: D031289:Albizzia / Q000737:chemistry*; D000972:Antineoplastic Agents, Phytogenic / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D004354:Drug Screening Assays, Antitumor; D004534:Egypt; D006027:Glycosides / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D019073:HT29 Cells; D056945:Hep G2 Cells; D006801:Humans; D015394:Molecular Structure; D019906:Nuclear Magnetic Resonance, Biomolecular; D009828:Oleanolic Acid / Q000031:analogs & derivatives* / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D024301:Plant Bark / Q000737:chemistry; D013237:Stereoisomerism; D013329:Structure-Activity Relationship; D014315:Triterpenes / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology
chemical_list: C552513:3-O-alpha-L-arabinopyranosyl-(1-2)-alpha-L-arabinopyranosyl-(1-6)-2-acetamido-2-deoxy-beta-D-glucopyranosyl echinocystic acid 16-O-beta-D-glucopyranoside; C552515:3-O-beta-D-xylopyranosyl-(1-2)-alpha-L-arabinopyranosyl-(1-6)-2-acetamido-2-deoxy-beta-D-glucopyranosyl echinocystic acid 16-O-beta-D-glucopyranoside; C552514:3-O-beta-D-xylopyranosyl-(1-2)-beta-D-galactopyranosyl-(1-6)-2-acetamido-2-deoxy-beta-D-glucopyranosyl echinocystic acid 16-O-beta-D-glucopyranoside; D000972:Antineoplastic Agents, Phytogenic; D006027:Glycosides; D014315:Triterpenes; D009828:Oleanolic Acid; C022999:echinocystic acid