Planta Medica, Inhaltsverzeichnis Planta Med 1993; 59(3): 264-268DOI: 10.1055/s-2006-959666 Paper © Georg Thieme Verlag Stuttgart · New YorkProanthocyanidins from Quercus petraea BarkErnst Pallenbach1 , Eberhard Scholz1 , Martin König1 , Horst Rimpler1 , 2 1Institut für Pharmazeutische Biologie, Schänzlestraße 1, D(W)-7800 Freiburg, Federal Republic of Germany 2Address for correspondence Artikel empfehlen Abstract als PDF herunterladen(opens in new window) Artikel einzeln kaufen(opens in new window) Abstract Flavanols and oligomeric proantho-cyanidins were isolated from oak bark (Quercus petraea) and characterized by acid hydrolysis, gel permeation chromatography, haemanalysis, and complete as well as partial thiolytic degradation. The proantho-cyanidins had an average polymerization degree of 6.1 and a procyanidin: prodelphinidin ratio of 6:4. The prevailing units of the oligomeric chains were (+)-catechin, (-)-epicatechin, and (+)-gallocatechin, minor units were (-)-epicatechin 3-O-gallate and (-)-epigallocatechin 3-O-gallate. The bark contains both hydrolyzable and condensed tannins. Although only 23% of the water-soluble oak bark tannins consisted of oligomeric proanthocyanidins, these contributed with 55% to the astringency of the total tannin fraction. Key words Quercus petraea - Fagaceae - tannins - pro-anthocyanidins - gallic acid - astringency. PDF (453 kb)
