The structures of two new monodesmosidic and bisdesmosidic triterpenoid saponins (1 and 2) and the known compound delta 5-stigmasterol-3-O-β-D-glucopyranoside (3) as well as two new oleanane type triterpene lactone glycosides 4, 5 and a new sapogenin lactone 6 isolated from the stem bark of Albizia gummifera C.A. Smith (Mimosaceae) have been elucidated as 3-O-{β-D-glucopyranosyl(1→2)-[α-L-arabinopyranosyl(1→6)]-β-D-glucopyranosyl}-oleanolic acid (1), β-D-glucopyranosyl(1→2)-β-D-glucopyranosyl-3-O-}β-D-glucopyranosyl(1→2)-[α-L-arabinopyrano syl(1→6)]-β-D-glucopyranosyl}-oleanolate (2), 3 β-{O-D-glucopyranosyl-(1→2)-[O-α-L-arabinopyranosyl(1→6 )] β-D-glucopyranosyloxy}-machaerinic acid gamma-lactone (4), 3β-O-β-D-glucopyranosiduronic acid (1→2)-β-D-glucopyranosyloxy]-machaerinic acid gamma-lactone (5), and A-homo-3a-oxa-5β-olean-12-en-3-one-28-oic acid (6), respectively. The complete assignment of the 1H and 13C resonances of 1, 2, 4 and 6 and of the peracetate of 5 were achieved by means of 2D-NMR studies.
stem bark, oleanolic acid glycosides, Mimosaceae, Albizia gummifera (C.A. Smith), machaerinic acid lactone glycosides, A-homo-3a-oxa-olean-12-en-28-oic acid, stigmasterol glycoside
NCBI PubMed ID: 10820798Publication DOI: 10.1016/s0031-9422(99)00464-1Journal NLM ID: 0151434Publisher: Elsevier
Correspondence: haslinger@kfunigraaz.ac.at
Institutions: Institut für Pharmazeutische Chemie, Universität Graz, Graz, Austria, Institut für Pharmakognosie, Universität Graz, Graz, Austria, Schering A.G., Berlin, Germany, Ethiopian Health and Nutrition Research Institute, Addis-Abeba, Ethiopia
Methods: 13C NMR, 1H NMR, NMR-2D, IR, GC-MS, TLC, ESI-MS, acid hydrolysis, GLC, alkaline hydrolysis, UV, extraction, capillary electrophoresis (CE), optical rotation measurement, acetylation, CC, melting point determination, derivatization, evaporation, PPC
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