Schmeda-Hirschmann,G. Laboratorio de Quımica de Productos Naturales,Instituto de Quımica de Recursos Naturales, Universidad de Talca, Casilla 747, Talca, Chile.The Paraguayan crude drug “tayı¨ pyta´” is used to treat cancer, wounds and inflammation.
It consist of the bark and trunkwood of Tabebuia heptaphylla (Bignoniaceae). A phytochemical
study of the crude drug gave, in addition to previously described naphthoquinones and
the known lignans cycloolivil and secoisolariciresinol, three new lapachenol (lapachonone)-,
two naphthofuran-, a chromone and a naphthalene derivative. The structures were elucidated
by means of high field NMR spectroscopy. The biological activity of the main compound
lapachol and the related α-lapachone as well as the lignans cycloolivil and secoisolariciresinol
can explain, at least in part, the effect atributed to the crude drug in Paraguayan folk medicine
