Extraction, Purification, Quantification, and Stability of Bioactive Spilanthol from Acmella oleracea

Area of Science:

• Natural Product Chemistry
• Phytochemistry
• Cosmetic Science

Background:

• Acmella oleracea is rich in spilanthol, a compound with anti-inflammatory, antioxidant, and muscle-relaxant properties.
• Spilanthol's ability to inhibit facial muscle contractions makes it a sought-after ingredient in anti-aging and anti-wrinkle cosmetics, often referred to as 'herbal Botox'.
• Commercial interest in spilanthol necessitates efficient extraction and quantification methods.

Purpose of the Study:

• To develop an effective method for extracting spilanthol from Acmella oleracea.
• To establish a simple, fast, and economical protocol for quantifying spilanthol concentration.
• To investigate the stability of spilanthol solutions and determine optimal storage conditions.

Main Methods:

• Extraction of spilanthol from all aerial parts of Acmella oleracea.
• Enrichment of spilanthol concentration by removing polar and acidic substances.
• Quantification using proton nuclear magnetic resonance (¹H NMR) and high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS).

Main Results:

• An effective method for obtaining Acmella oleracea extracts with high spilanthol content was developed.
• A simple, fast, and economical ¹H NMR protocol for spilanthol quantification was established.
• A sensitive, precise, and accurate HPLC-MS/MS method (LOQ=1 ng/mL) was applied for result confirmation. The oxidation product of spilanthol was identified as (2E,7Z)-6,9-endoperoxy-N-(2-methylpropyl)-2,7-decadienamide.

Conclusions:

• The developed methodology enables efficient spilanthol extraction and enrichment from Acmella oleracea.
• The established ¹H NMR protocol provides a feasible method for spilanthol quantification.
• Stability studies have led to the development of conditions for long-term storage of spilanthol solutions.