Oleanane-type triterpenes of Embelia schimperi leaves.
An investigation of an ethyl acetate extract of Embelia schimperi leaves has led to the isolation of 10 oleanane-type triterpenes characterized as 3beta,16alpha-di-O-acetyl-13beta, 28-epoxyoleanane (1), 3beta-acetyl-16-oxo-13beta, 28-epoxyoleanane (2), 3beta-acetyl-16alpha-hydroxy-13beta, 28-epoxyoleanane (3), 3beta-acetyl-16alpha-hydroxyoleanane-13beta, 28-olide (4), 3beta-acetyl-28-hydroxy-16-oxo-12-oleanene (5), 3beta, 28-di-O-acetyl-16alpha-hydroxy-12-oleanene (6), 3beta-acetyl-11alpha, 28-dihydroxy-16-oxo-12-oleanene (7), 3beta, 11alpha, 16alpha, 28-tetrahydroxy-12-oleanene (8), 3beta-acetyl-16alpha, 28alpha-dihydroxy-13beta, 28-oxydooleanane (9) and 3beta, 28alpha-dihydroxy-16-oxo-13beta, 28-oxydooleanane (10). The known compounds isolated from the same extract included 3beta, 16alpha-dihydroxy-13beta, 28-epoxyoleanane (protoprimulagenin A) (11), 3beta-hydroxy-16-oxo-13beta, 28-epoxyoxyoleanane (aegicerin) (12), 3, 16-dioxo-13beta, 28-epoxyoleanane (embilionone) (13), 3beta, 28-dihydroxy-16-oxo-12-oleanene (schimperinone) (14), taraxerone (15), taraxerol (16) and stigmasterol (17). Structure elucidations were carried out spectroscopically.
Manguro
Lawrence Onyango Arot
LO
Department of Chemistry, Maseno University, Private Bag, Maseno, Kenya. kamanguro@yahoo.com
Okwiri
Steve Onyango
SO
Lemmen
Peter
P
D031645:Embelia / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D009828:Oleanolic Acid / Q000031:analogs & derivatives / Q000737:chemistry / Q000302:isolation & purification; D018515:Plant Leaves / Q000737:chemistry*; D014315:Triterpenes / Q000737:chemistry* / Q000302:isolation & purification
D014315:Triterpenes; C413246:oleanane; D009828:Oleanolic Acid