Antileishmanial activity of indole alkaloids from Aspidosperma ramiflorum

The present study was designated to evaluate the antileishmanial activity of acid and basic fractions that were obtained after acid-basic extraction, from ethanolic 70% crude extract and pure compounds from the stem bark of Aspidosperma rainiflorum. The basic alkaloidal fraction presented a good activity against the extracellular form (promastigotes) of Leishimania (L.) amazonensis (LD50 value < 47 mu g/ml). Based on these findings, the basic fraction was fractionated on silica gel column chromatography in a bioassay-guided fractionation affording individual purified ramiflorines A and B. Both ramiflorines A and B showed significant activity against Leishmania (L.) amazonensis (LD50 values of 16.3 +/- 1.6 mu g/ml and 4.9 +/- 0.9 mu g/ml, respectively). Our results are promising, showing that these compounds are biologically active against Gram-positive bacteria. (C) 2006 Elsevier GmbH. All rights reserved.