Résumé
The bioassay-guided purification of the ethanolic extract from the leaves of Piper hispidum led to the isolation of one new amide, N-2-(3',4',5'-trimethoxyphenyl)ethyl-2-hydroxybenzamide (1) as well as two known chalcones 2'-hydroxy-3',4',6'-trimethoxychalcone (2); 2',4'-dihydroxy-6'-methoxychalcone (cardamonin, 3) and one known flavanone, 5,7-dihydroxyflavanone (Pinocembrin, 4). Their structures were elucidated on the basis of spectroscopic data, including homo-and heteronuclear correlation NMR experiments (COSY, HSQC and HMBC) and comparison with data reported in the literature. The isolated compounds were tested against Leishmania amazonensis axenic amastigotes. The results showed that the known chalcone 2 exhibited the most potent antileishmanial activity with an IC(50) of 0.8 mu M (amphotericin B: IC(50) = 0.2 mu M) but was shown to exhibit mild cytotoxicity. (C) 2011 Phytochemical Society of Europe. Published by Elsevier B.V. All rights reserved.