Triterpene saponins from the roots of Medicago hybrida.
Fourteen triterpene saponins (1-14) have been isolated from the roots of Medicago hybrida and their structures elucidated by FAB-MS and NMR analysis. Two of them are new compounds and were identified as hederagenin 3-O-[alpha-L-rhamnopyranosyl(1-->2)-beta-D-glucopyranosyl(1-->2)-beta-D-glucopyranosyl]-28-O-beta-D-glucopyranoside (7) and oleanolic acid 3-O-[beta-D-galactopyranosyl(1-->2)-beta-D-glucuronopyranosyl]-28-O-[alpha-L-rhamnopyranosyl(1-->4)-beta-D-glucopyranoside] (14). Seven saponins being mono- and bidesmosides of hederagenin (1, 5, 6, 9), one bidesmoside of bayogenin (2), and two bidesmosides of 2beta,3beta-dihydroxyolean-12-en-23-al-28-oic acid (11) and oleanolic acid (13) are known compounds but not previously reported as saponin constituents of Medicago, whereas five other saponins, being mono- and bidesmosides of medicagenic acid (3, 4, 8, 10, 12), and one monodesmoside of hederagenin (8) have been previously isolated from other Medicago species. The presence of 2beta,3beta-dihydroxyolean-12-en-23-al-28-oic acid might represent an interesting intermediate in the biosynthesis of these substances.
Department of Biochemistry, Institute of Soil Science and Plant Cultivation, Czartoryskich 8, 24-100 Pulawy, Poland.
Zbigniew
Z
Bialy
Marian
M
Jurzysta
Mariella
M
Mella
Aldo
A
Tava
D009682:Magnetic Resonance Spectroscopy; D029902:Medicago / Q000737:chemistry*; D015394:Molecular Structure; D018517:Plant Roots / Q000737:chemistry*; D012503:Saponins / Q000737:chemistry / Q000302:isolation & purification*; D016339:Spectrometry, Mass, Fast Atom Bombardment; D014315:Triterpenes / Q000737:chemistry / Q000302:isolation & purification*
D012503:Saponins; D014315:Triterpenes