An unprecedented chlorine-containing piperamide from Piper pseudoarboreum as potential leishmanicidal agent

Abstract

A phytochemical investigation of the ethanolic extract of leaves from Piper pseudoarboreum led to the isolation of 3-chlorosintenpyridone 1, an unprecedented chlorinated piperamide, together with the known compounds 2–12. Their structures were established based on 1D and 2D (COSY, ROESY, HMQC, and HMBC) NMR spectroscopy, in addition to high resolution mass spectrometry. The proposed biosynthetic pathway of compound 1 is discussed. Compounds 1–12 were tested in vitro for their leishmanicidal potential against promastigote stages of Leishmania amazonensis, L braziliensis, L. guyanensis and L. infantum. Two compounds from this series, the alkamide 1 (IC50 3.4–5.2 μM) and the fatty acid 9 (IC50 18.7–29.6 μM) displayed higher or similar potency to Miltefosine, used as the reference drug.