title: Characterization and Physicochemical Properties of Condensed Tannins from Acacia catechu.
abstract: Condensed tannins from Acacia catechu were carefully studied to determine their chemical structure and physicochemical properties. The combined use of MALDI-TOF-MS and (13)C NMR revealed that catechin and epicatechin are the predominant monomers. Most of the compounds were dimers, as confirmed by size exclusion chromatography measurements. To evaluate their potential as aromatic building block in polymer synthesis, special care was given to the characterization and quantification of the different OH groups. A detailed (31)P NMR analysis showed the predominance of catechin, with a catechin/epicatechin ratio of 4.2:1. Two distinct (1)H NMR measurements confirmed the quantification. The thermal properties were also determined: the tannins showed a high temperature of degradation (ca. 190 °C) and a high glass transition temperature (ca. 140 °C), allowing for thermal processing or chemical reactions at relatively high temperature. A. catechu tannins thus present interesting features to be used as aromatic building blocks in polymer materials.
authors: Bioteam/ICPEES-ECPM, UMR 7515, Université de Strasbourg , 25 rue Becquerel, 67087 Strasbourg Cedex 2, France.
authors: Antoine
authors: A
authors: Duval
authors: Bioteam/ICPEES-ECPM, UMR 7515, Université de Strasbourg , 25 rue Becquerel, 67087 Strasbourg Cedex 2, France.
authors: Luc
authors: L
authors: Avérous
mesh_terms: D000045:Acacia / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D010936:Plant Extracts / Q000737:chemistry*; D044945:Proanthocyanidins / Q000737:chemistry*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
chemical_list: D010936:Plant Extracts; D044945:Proanthocyanidins
keywords: 13C NMR; 1H NMR; 31P NMR; Acacia catechu; MALDI-TOF; tannins