Extraction and Antioxidant Activity of Flavonoids from Seed Coat of Borassus flabellifer Linn using Orthogonal Array (L16(4^4))

Abstract

This study aimed at optimizing the conditions required for maximal extraction of flavonoids from the seed coat of Borassus flabellifer and to evaluate antioxidant properties. Initially, the parameters like time, temperature, solvent concentration and material ratio were optimized using orthogonal design of experiments. Temperature was found to play a significant role in the maximum extraction of flavonoids and the optimum conditions were found to be 85°, 3 h, 70 % aqueous-ethanol and 1:20 material ratio. The crude samples were tested for antioxidant activity using the 1,1-diphenyl-2-picrylhydrazyl radical scavenging assay. Percent inhibition of the 1,1-diphenyl-2-picrylhydrazyl radical was found highest (95 %) at 50 μg/ml concentration of the extract of seed coat of B. flabellifer. Flavonoids were then purified using preparative thin layer chromatography. The purified sample did not reveal significant antioxidant activities. Hence, further purification of the sample is needed to obtain better results.