title: Naphthoquinone derivatives and lignans from the Paraguayan crude drug "tayï pytá" (Tabebuia heptaphylla, Bignoniaceae).
abstract: 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 alpha-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.
authors.affiliation: Laboratorio de Química de Productos Naturales, Instituto de Química de Recursos Naturales, Universidad de Talca, Casilla 747, Talca, Chile. schmeda@utalca.cl
authors.forename: Guillermo
authors.initials: G
authors.lastname: Schmeda-Hirschmann
authors.forename: Fani
authors.initials: F
authors.lastname: Papastergiou
mesh_terms: D000818:Animals; D000977:Antiparasitic Agents / Q000494:pharmacology*; D029402:Bignoniaceae / Q000737:chemistry*; D007893:Leishmania donovani; D017705:Lignans / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology*; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D008968:Molecular Conformation; D009285:Naphthoquinones / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology*; D010239:Paraguay; D010936:Plant Extracts / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology; D018547:Plant Stems / Q000737:chemistry*; D010946:Plants, Medicinal / Q000737:chemistry*
chemical_list: D000977:Antiparasitic Agents; D017705:Lignans; D009285:Naphthoquinones; D010936:Plant Extracts