Flavanoid present in the bark and stems of a variety of trees. Isolation from Rhus cotinus L. Anacardiaceae, Venetian Sumach: Chevreul, Lecons Chim. Appl. a la Teint. 2, 169 (1833) [cf. J. Schmid, Ber. 19, 1734 (1886)]; from heartwood of Acacia spp, Leguminosae: Roux et al., Biochem. J. 78, 834 (1961). Structure: Seshadri, Annu. Rev. Biochem. 20, 492 (1951). Synthesis: St. Kostanecki et al., Ber. 37, 784 (1904); J. Allan, R. Robinson, J. Chem. Soc. 129, 2334 (1926). Inhibition of aflatoxin cytotoxicity: A. G. Schwartz, W. R. Rate, J. Environ. Pathol. Toxicol. 2, 1021 (1979). Mutagenicity studies: J. P. Brown et al., Biochem. Soc. Trans. 5, 1489 (1977); idem, P. S. Dietrich, Mutat. Res. 66, 223 (1979). TLC determn: D. Heimler, J. Chromatogr. 366, 407 (1986).