Quantitative Analysis of Phytoconstituents and in Vitro Antioxidant Activity of Pyrostegia venusta Leaves

Abstract

Pyrostegia venusta (Ker-Gawl) Miers (family, Bignoniaceae) is a neotropic evergreen vine, also known as Orange trumphet.  The present study aimed to investigate quantitative analysis of leaves of Pyrostegia venusta in different extracts using standard methods. From the preliminary examination it has been found that extracts gave result for phenolic, flavonoids and protein contents. The quantitative studies for phenol, flavonoids and protein were performed present in different extracts like chloroform, ethyl acetate, methanol and water. The quantitative estimation was carried out using modified folin-ciocalteu method, taking gallic acid as standard, flavonoids content was based on aluminum chloride method taking quercetin as standard, protein content estimated by Lowry’s method taking bovine serum albumin as standard. Also, the in vitro antioxidant activity of methanolic extract was carried out by 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay and Hydrogen Peroxide method calculating the IC50 values. In DPPH method, ascorbic acid was taken as standard having IC50 value 14.55 µg/ml while methanolic extract gave IC50 value 33.38 µg/ml and in hydrogen peroxide method the IC50 value calculated for ascorbic acid is 7.58 µg/ml and that of methanolic extract was 62.70 µg/ml. So, a comparison of antioxidant potential was being made using the two methods.