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Characterization of condensed tannins and carbohydrates in hot water bark extracts of European softwood species.
Journal article

Characterization of condensed tannins and carbohydrates in hot water bark extracts of European softwood species.

  • Bianchi S Bern University of Applied Sciences, Architecture Wood and Civil Engineering, Solothurnstrasse 102, 2502 Biel, Switzerland. Electronic address: sauro.bianchi@bfh.ch.
  • Kroslakova I Zurich University of Applied Sciences, Institute of Chemistry and Biological Chemistry, Einsiedlerstrasse 31, 8820 Wädenswil, Switzerland.
  • Janzon R University of Hamburg, Department of Chemical Wood Technology, Leuschnerstraβe 91b, 21031 Hamburg, Germany.
  • Mayer I Bern University of Applied Sciences, Architecture Wood and Civil Engineering, Solothurnstrasse 102, 2502 Biel, Switzerland.
  • Saake B University of Hamburg, Department of Chemical Wood Technology, Leuschnerstraβe 91b, 21031 Hamburg, Germany.
  • Pichelin F Bern University of Applied Sciences, Architecture Wood and Civil Engineering, Solothurnstrasse 102, 2502 Biel, Switzerland.
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  • 2015-11-09
Published in:
  • Phytochemistry. - 2015
Abies alba
Carbohydrates
Condensed tannins
Larix decidua
MALDI-TOF MS
Picea abies
Pinus sylvestris
Pseudotsuga menziesii
Softwood bark extracts
Thiolysis
Biflavonoids
Catechin
Chromatography, High Pressure Liquid
Flavonoids
Glucosides
Hot Temperature
Molecular Structure
Norway
Picea
Pinus
Plant Bark
Plant Extracts
Proanthocyanidins
Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
Tannins
Water
English Condensed tannins extracted from European softwood bark are recognized as alternatives to synthetic phenolics. The extraction is generally performed in hot water, leading to simultaneous extraction of other bark constituents such as carbohydrates, phenolic monomers and salts. Characterization of the extract's composition and identification of the extracted tannins' molecular structure are needed to better identify potential applications. Bark from Silver fir (Abies alba [Mill.]), European larch (Larix decidua [Mill.]), Norway spruce (Picea abies [Karst.]), Douglas fir (Pseudotsuga menziesii [Mirb.]) and Scots pine (Pinus sylvestris [L.]) were extracted in water at 60°C. The amounts of phenolic monomers, condensed tannins, carbohydrates, and inorganic compounds in the extract were determined. The molecular structures of condensed tannins and carbohydrates were also investigated (HPLC-UV combined with thiolysis, MALDI-TOF mass spectrometry, anion exchange chromatography). Distinct extract compositions and tannin structures were found in each of the analysed species. Procyanidins were the most ubiquitous tannins. The presence of phenolic glucosides in the tannin oligomers was suggested. Polysaccharides such as arabinans, arabinogalactans and glucans represented an important fraction of all extracts. Compared to traditionally used species (Mimosa and Quebracho) higher viscosities as well as faster chemical reactivities are expected in the analysed species. The most promising species for a bark tannin extraction was found to be larch, while the least encouraging results were detected in pine. A better knowledge of the interaction between the various extracted compounds is deemed an important matter for investigation in the context of industrial applications of such extracts.
Language
  • English
Open access status
closed
Identifiers
Persistent URL
https://sonar.ch/global/documents/273808
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