Screening of Chinese rain tree (Koelreuteria elegans) leaves, bark and defatted seed cake for study of their total phenolic content, flavonoids and antioxidant properties

Abstract

The aim of the study was to analyse methanolic crude extract of leaves, bark and defatted seed cake of Koelreuteria elegans for total phenolics, flavonoids and antioxidant properties. Total phenolic contents were determined using Folin-Ciocalteau reagent and calculated as Gallic Acid equivalents per gram of extract. Aluminium chloride colorimeteric method was used for flavonoids determination. The antioxidant activities of the extracts were measured by 2, 2’-diphenyl-1-picrylhydrazyl (DPPH) method. The bark extract showed maximum antioxidant activity of 96 % at a conc. of 0.06 mg/mL with EC50 value 0.023±0.002 mg/mL of extract followed by leaves extract 95 % at a conc. of 0.07 mg/mL with EC50 value 0.022±0.002 and the seed cake extract 93 % at a conc. of 0.07 mg/mL with EC50 value 0.025±0.001 by DPPH method. Based on observations, it can be concluded that Chinese rain tree bark, leaves and the seed cake have a potential source of antioxidants of natural origin.