Phytochemical screening, estimation of total phenols, total flavonoids and determination of antioxidant activity in the methanol extract of Dendrobium denudans D. Don stems

Abstract

The aim of the present study was to investigate the phyto-constituents present within the methanol extract of Dendrobium denudans D. Don stem and to estimate total phenols, total flavonoids and antioxidant activity. Phytochemical studies confirmed the presence of carbohydrates, phenols and flavonoids. The amount of total phenols and flavonoids were analyzed using a spectrophotometric technique, based on Folin-Ciocalteau reagents and aluminium chloride colorimetric assay, respectively. Gallic acid was used as standard compound for total phenols and catechin for total flavonoids. Furthermore, the antioxidant activity was determined by using two in-vitro models namely, 2, 2-diphenyl-1-picrylhydrazyl (DPPH) and reducing power methods. In both the methods, ascorbic acid was used as reference compound. The presence of antioxidant compound, rutin in the methanol extract was determined by High Performance Liquid Chromatography (HPLC) analysis. rnThe total phenols and flavonoids were found to be 129.02±0.865 mgGAE/g and 108.333±1.155 mg CAT/g respectively. IC50 of methanol extract was found to be 153.509±3.476 µg/mL and 10.052±2.365 µg/mL for DPPH and reducing power assays respectively.