Spilanthol from Spilanthes acmella flowers, leaves and stems obtained by selective supercritical carbon dioxide extraction

Spilanthes acmella var oleracea, commonly known as jambu is a natural source of secondary metabolites such as alkylamides which are responsible for the anti-inflammatory, antiseptic and anesthetic bioactivities of the plant. The purpose of this work was to characterize the extracts obtained from jambu flowers, leaves and stems by a fractionated extraction procedure that included a supercritical fluid extraction (SFE) step, using supercritical carbon dioxide as solvent, followed by an enhanced solvent extraction (ESE) step using pressurized CO2 with ethanol, water and their mixtures as solvent enhancers. Results show that the flowers are richer in spilanthol, which justifies the highest antioxidant/total phenolic ratio as well as the highest anti-inflammatory activity. SFE proved to be particularly selective for spilanthol, mainly in the case of the flowers, yielding solvent free extracts with a yellow color, adequate to be used without further time consuming and solvent dependent purification processes. (C) 2011 Elsevier B.V. All rights reserved.