Chemical Composition of Tannins and Polyphenols from Conifer Wood and Bark

Methanol extracts of the wood and bark of twelve species of conifers, representing ten genera, were characterized using spectroscopy and two-dimensional paper chromatography. Cedrus, Taxodium, Pseudotsuga, Picea, Sequoia, Pinus, Tsuga, Larix, Thuja, and Taxus extracts all contained monomeric leucocyanidins and catechins with higher concentrations near the cambium. Concentration of tannins increased in the bark-to-pith direction. Distribution patterns and the presence of cyanidin and catechin units in the tannins strongly suggest that tannins and heartwood color are derived from these monomers. Knowledge of variations in polyphenolic character and content can be a useful taxonomic tool. Chemical composition of the extracts from each genera, in relation to commercial possibilities (particularly tanning) and current use in the U.S. and other countries, are discussed.

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