Condensed tannins. 4. The distribution and deposition of tannins in the heartwoods of Acacia mollissima and Schinopsis spp

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Abstract
The isolation of (+)-catechin and gallic acid from the young heartwood of Schinopsis spp. and the tentative identification of fustin and fisetin in the heartwood of A. mollissima are described. These heartwoods contain enantiomorphous (-)- and (+)-leucofisetinidins respectively, and the vertical and radial distribution of their tannins in relation to average molecular weight, leucoanthocyanidin content and concentration of associated non-tannins'' are examined and contrasted. There is evidence that typical condensed tannins are formed in the cells in which their flavan precursors are initially deposited in the heartwood periphery. A vertical ''coning'' effect is present in the heartwood of the upper portion of the trunk of Schinopsis quebracho-colorado with regard to molecular weight and tannin/non-tannin ratio. The heartwood tannins of A. mollissima consist of a gradation over he molecular-weight range 290-1650 in which the yield of anthocyani-lins decreases with increasing average molecular weight.