Condensed tannins. 8. The isolation and distribution of interrelated heartwood components of Schinopsis spp

Abstract

([plus or minus])-Fustin has been isolated from the heartwoods of Schinopsis balansae, S.quebracho-colorado and from commercial quebracho extract. (-)-Fustin predominates (66%) in the extract of S. balansae and in the commercial extract. Other known and some related components have also been isolated by means of Craig counter-current separations followed by absorption separation on cellulose. The radial and vertical distribution of (-)-7:3[image]:[image]-trihydroxyflavan -3:4-diol, (+)-catechin, gallic acid, ([plus or minus])-fustin, fisetin and 2-benzyl-2-hydroxycoumaran-3-ones in the heartwood of S. quebracho-colorado has been estimated. The possible role these compounds play in the bio-genesis of tannins and the interconversions of the compounds related to (-)-7:3[image]:4[image]-trihydroxy-flavan-3:4-diol are discussed.