Estudo fitoquímico e atividade Leishmanicida para a de Annona impressivenia Safford (Annonaceae)

Abstract

Annona impressivenia Safford (Annonaceae) it is a species known popularly as "graviola-brava". It is a rare tree distributed of Guyana Venezuelan to the Amazonian Central. This work describes the results obtained from the phytochemical study and the anti-leishmanial assay of the extracts of the heartwood and stem bark of this plant against promastigote forms of Leishmania amazonensis and L. guyanensis. The botanical material was submitted to conventional analysis to separation of alkaloids. Among the investigated samples, the dichloromethane extracts and the dichloromethane neutral fraction of the stem bark and chloroform alkaloid fraction of the heartwood presented significant antileishmanial activity in vitro against L. guyanensis. Just the dichloromethane extract of the heartwood presented activity against promastigote form L. amazonensis. The phytochemical analysis of the dichloromethane extract of the stem bark revealed the presence of the oxoaporphine alkaloid liriodenine, commonly found in species of the family Annonaceae, and the pyrimidine-β-carboline-type alkaloid known as methoxyannomontine. From the dichloromethane extract of theheartwood, besides the alkaloid liriodenine, the azaanthraquinone-type alkaloid cleistofoline was isolated. The probable presence of the acetogenins in the hexane extracts (heartwood and stem bark) it was also detected. The identification of the isolated substances was accomplished through espectroscopic analyses (IV, H and C NMR 1D and 2D) and by comparisons with data of the literature.