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Naphthoquinone Derivatives and Lignans from the Paraguayan Crude Drug “Tayï Pytá” (Tabebuia heptaphylla, Bignoniaceae)

Schmeda-Hirschmann, Guillermo; Papastergiou, Fani

The Paraguayan crude drug “tayï pytá” 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.
Published in: Zeitschrift für Naturforschung C, 10.1515/znc-2003-7-809, De Gruyter