Schmeda-Hirschmann, GuillermoPapastergiou, Fani2018-10-022018-10-0220030939-5075https://depositonce.tu-berlin.de/handle/11303/8265http://dx.doi.org/10.14279/depositonce-7416The 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.en570 Biowissenschaften; BiologieTabebuia heptaphyllaBignoniaceaeNaphthoquinonesArticle1865-7125