Chemical constituents and biological activities of the fruits of <i>Knema pachycarpa</i> de Wilde

Abstract

The <i>n</i>-hexane extract of <i>Knema pachycarpa</i> fruits (Myristicaceae family), exhibiting strong anti-acetylcholinesterase activity, was investigated by gas chromatography/mass spectrometry and then purified by column chromatography. Guided by GC/MS profiling and bioassay, chromatographic separations led to the isolation of five new compounds: two anacardic acid derivatives <b>1</b>-<b>2</b>, two cardanol derivatives <b>3</b>-<b>4</b> and a cardol derivative <b>5</b>, along with mixtures of known phenolic lipids <b>6</b>-<b>9</b>. The chemical structures were determined by various spectroscopic methods. New isolated compounds <b>1</b>-<b>5</b> were evaluated for their cytotoxicity and anti-acetylcholinesterase activity. Cardanol <b>3</b> and cardol <b>5</b> were the most active compounds in the acetylcholinesterase inhibitory assay with IC₅₀ values of 2.60 ± 0.24 µM and 2.46 ± 0.23 µM, respectively. Cardanol <b>4</b> and cardol <b>5</b> showed moderate cytotoxicity against Hela and MCF-7 cancer cell lines with IC₅₀ values ranging from 31.36 ± 0.41 µM to 41.30 ± 2.49 µM.