Naturally occurring quinones. Part XII. Extractives from Tabebuia chrysantha nichols and other bignoniaceae

Abstract

The following compounds have been isolated from the heartwood of T. chrysantha: lapachol, α- and β-lapachone, dehydro-α-lapachone, 1-hydroxy-2-methyl- and 2-hydroxy-3-methyl-anthraquinone, lapachenole, dihydrolapachenole, nordihydrolapachenole, dehydrotectol, and tetrahydrotectol and its dimethyl ether. The sapwood contained lapachenole, dihydrolapachenole, and 1-methoxynaphthalene. The extractives of a T. dönnell-smittii veneer and Paratecoma peroba heartwood are similar but anthraquinones and tectol-type dimers are absent. 1-Methoxynaphthalene, also present in the heartwood of P. peroba, or an equivalent, is probably the first naphthalenic intermediate on the biogenetic pathway to the C₁₅ compounds and dimers.