Identification of bioactive compounds in Phyllenthus emblica L. fruit and their free radical scavenging activities

Emblica has been used as an important traditional herbal medicine in southeast Asia since ancient times. In this study, the air-dried hulls of emblica fruit were extracted with 95% ethanol, and then the extract was partitioned by diethyl ether and ethyl acetate (EA). The EA fraction was purified by silica gel column and thin layer chromatography (TLC) to obtain six compounds. They were identified as cinnamic acid (C1), quercetin (C2), 5-hydroxymethylfurfural (C3), gallic acid (C4), β-daucosterol (C5) and ellagic acid (C6) using mass spectrometry and nuclear magnetic resonance (NMR) spectroscopy. Cinnamic acid and 5-hydroxymethylfurfural were identified as components of emblica fruit for the first time. The DPPH and ABTS⁺ radical scavenging activities of components were evaluated. All the compounds showed significant DPPH and ABTS⁺ radical scavenging activity except for cinnamic acid. Gallic acid showed the highest DPPH radical scavenging activity while ellagic acid showed the highest ABTS⁺ scavenging activity amongst all the compounds tested.