Prodelphinidin trimers and characterization of a proanthocyanidin oligomer from Cistus albidus.
Two new natural prodelphinidin trimers have been isolated from the air-dried herb of Cistus albidus, epigallocatechin-(4beta --> 8)-gallocatechin-(4alpha --> 8)-catechin and epigallocatechin-(4beta --> 8)-gallocatechin-(4alpha --> 8)-gallocatechin in addition to catechin, gallocatechin and thirteen known proanthocyanidins. The structures were determined on the basis of 1D- and reverse 2D-NMR (HSQC, HMBC) experiments of their peracetylated derivatives, MALDI-TOF-MS and by acid-catalysed degradation with phloroglucinol. A more abundant higher oligomeric proanthocyanidins fraction was also isolated and its chemical constitution studied by 13C-NMR. The mean molecular weight of the higher oligomeric fraction was estimated to be 6-7 flavan-3-ol-units.
Qa'Dan
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F
Faculty of Pharmacy, The University of Petra, Amman, Jordan. f_qadan@yahoo.com
Petereit
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F
Nahrstedt
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A
D000872:Anthocyanins / Q000737:chemistry*; D000975:Antioxidants / Q000737:chemistry; D029758:Cistus / Q000737:chemistry*; D007202:Indicators and Reagents; D009682:Magnetic Resonance Spectroscopy; D008970:Molecular Weight; D010696:Phloroglucinol / Q000737:chemistry; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology; D044945:Proanthocyanidins; D012997:Solvents; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
D000872:Anthocyanins; D000975:Antioxidants; D007202:Indicators and Reagents; D010936:Plant Extracts; D044945:Proanthocyanidins; D012997:Solvents; C472180:prodelphinidin B-2 3'-O-gallate; C013221:proanthocyanidin; D010696:Phloroglucinol