Supercritical fluid extraction of chebulagic acid from Terminalia bellirica fruits (Baheda)

Abstract

Chebulagic acid is a hydrolyzable tannin found in the fruits of Terminalia bellirica and has been extensively used in traditional Indian medicine. Currently, most of the chebulagic acid is extracted from Terminalia chebula and a lesser extent, from T. bellirica. Crude chebulagic acid extracts from these fruits are usually extracted using Soxhlet extraction or reflux methods before purification using column chromatography and High-Performance Liquid Chromatography (HPLC). We examined supercritical fluid extraction efficiency with or without a modifier in extracting chebulagic acid from T. bellirica fruit powder in the present study. Our results demonstrated that supercritical fluid extraction with 50% ethanol as a modifier (SFEM) was the most efficient method in extracting chebulagic acid from T. bellirica fruit powder compared to supercritical fluid extraction without modifier (SFE) and Soxhlet extraction (SE) methods. This new extraction method (SFEM) yielded 96.10% ± 3.34 (w/w) chebulagic acid with 96.9% ± 1.34 purity and 95.21% ± 0.14 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging activity, requiring no further purification. HPLC was used to confirm the purity of chebulagic acid and the chemical structure was confirmed using their mass spectroscopy (MS) and 1H nuclear magnetic resonance (NMR) spectra. This one-step extraction and purification method is clean, uses less liquid solvent compared to the conventional Soxhlet method, and the extraction process requires 92% less time. Novelty impact statement: In this current study, the supercritical fluid extraction method yielded 96.10% ± 3.34 (w/w) chebulagic acid with 96.9% ± 1.34 purity and required no further purification. In addition, this one-step extraction and purification method is clean, uses less liquid solvent compared to the conventional Soxhlet method, and the extraction process requires 92% less time.