Quantitative Analysis of Gallic acid and Quercetin by HPTLC and In vitro Antioxidant activity of Averrhoa carambola Linn

The preliminary phytochemical screening of ethanolic extracts of Averrhoa carambola (A. carambola) leaves were done using the standard protocol. The findings of phytochemical analysis exhibited the occurrence of Carbohydrates, Alkaloids, Steroids, Tannins, Vitamin C and flavonoids by using the Folin-Ciocalteu technique and the aluminum chloride colorimetric technique, respectively, the whole phenolic or flavonoid amounts were evaluated and were found 194.48±0.723 mg/g of dry extract as equivalent to gallic acid and 54.83±0.108 mg/g of dry extract as equivalent to quercetin respectively. In vitro, antioxidant activity was evaluated using 2,2-diphenlyl-1-picrylhydrazyl (DPPH), Hydrogen peroxide (H2O2), and Nitric oxide (NO) method. Ethanolic extract of A. carambola leaves showed good In vitro antioxidant action. Thin layer chromatography (TLC) of the ethanolic extract was carried out with gallic acid and quercetin as the reference biomarkers. HPTLC (High-Performance Thin Layer Chromatography technique was applied to detect spots and quantification for gallic acid and quercetin. The Rf values of gallic acid and quercetin were found 0.25 and 0.53 respectively. The amounts of gallic acid and quercetin were found to be 502.7 µg and 458.3 µg/100 mg of the ethanolic extract of A. carambola leaves separately.