Quebracho Colorado. Quebracho Gum. Schinopsis lorentsii.
Quebracho Colorado and Quebracho Gum are respectively the wood and the dried juice or aqueous extract of the Schinopsis Lorentsii (Gries.) Engl. (fam. Anacardiaceae), a large tree growing in the Argentine Republic. The wood is very heavy, hard, and of a reddish-brown color. (See A. J. P., 1879, p. 152; also Penzoldt, loc. cit.; P. J., xii.) Quebracho Colorado has been used as a substitute for the true quebracho, but is essentially different from it, and probably is a simple astringent and gastro-intestinal stimulant, although Penzoldt claims that it is similar in its action, but much weaker than quebracho blanco. The extract, which contains about 70 per cent. of tannin, is extensively used in the tanning of leather. In appearance it is somewhat intermediate between kino and logwood extract. Perkin and Gunnel have determined the yellow coloring matter of the wood of quebracho Colorado to be identical with fisetin, C15H10O6, the coloring matter of young fustic, Rhus Cotinus L.. It occurs in glistening yellow needles, dyeing similarly to quercitin, and yields compounds with mineral acids. Its benzoyl and acetyl derivatives have also been prepared. Fused with alkalies it yields protocatechuic acid and probably resorcinol. Ellagic and gallic acids have also been obtained from the wood, these being probably formed during the isolation of the fisetin. (A J. P., Nov., 1896, 626.)