Constituintes químicos das raízes e cascas do caule de Tabebuia aurea (Silva Manso) Benth & Hook (Bignoniaceae) e atividades antiparasitárias

Abstract

The species Tabebuia aurea belongs to the genus Tabebuia, one of the main representatives of the family Bignoniaceae, with about 100 native species of tropical forests throughout Central America and South America. The species in the study has occurrence throughout the national territory, and that in the Pantanal region it is known as a "holy remedy", where the population uses it as an alternative for the treatment of several diseases, such as yellowing, diabetes, fever, malaria and hepatitis and influenza. This work presents the phytochemical study of extracts ethanolic the roots and methanolic of stem bark which resulted in obtaining five acids: the 3.4-dimetoxibenzóico (I) known as verátrico acid, the phydroxybenzoic acid (II), the trans-4-hidroxicinâmico (III) known as p-cumárico, the trans-4- methoxycinnamic acid (IX) and the cis-4-hidroxicinâmico (X); a derivative benzaldehyde: 2,3-dihydroxy-5-(hydroxymethyl) (IV); four steroids: colestanone (V), β-sitosterol (VI), stigmasterol (VII), campesterol (VIII) and a iridoid: the 6-O-coumaroylcatalpol (XI) known as specioside. And still reports significant activity of specioside in tests of cellular viability against parasites Leishmania amazonensis and Trypanossoma cruzi. It was found that the substance presented 65% of cell death in the concentration of 157.4 μM and concentration of 190.0 μM caused 90% mortality cellular, or 90% of cell lysis of L. amazonensis promastigotes forms and in concentrations of 157.4 and 190.0 μM presented 70 and 73% of cell mortality against epimastigotes of T. cruzi. These results were very promising and demonstrate the importance of iridoid as an alternative for the treatment of Leishmaniasis and Chagas’ disease.