Antioxidant Active Compounds from Elaeocarpussylvestris and their Relationship between Structure and Activity

Three antioxidantactivecompounds from methanolic extract of Elaeocarpussylvestrisleaves are isolated by column chromatography and preparative TLC. Based on instrumental analysis, the compounds are identified as ellagic acid (1), gallic acid (2), and methyl gallate (3). The compounds have good antioxidant activity on scavenging DPPH radicals, reducing power and β-carotene bleaching assays. Further analysis of relationship between structures and activity of isolated compounds and fourteenbenzoic acid derivatives are also investigated. The result shows thatnumber and position of phenolic hydroxyl groups are important forantioxidant activity, particularly in ortho and para position. This study suggests that methanolic extract of E. sylvestris is potential as a natural antioxidant source.