Antioxidant activity and total phenolic content of different varieties of Portulaca grandiflora

摘要

Crude extracts from the whole plant of five different varieties (white, purple red, orange, pink and red) of Portulaca grandiflora were screened for their in vitro antioxidant and total phenolic content. These plants were extracted by methanol, acetone and ethanol, respectively. Their total phenolic content as determined by Folin-Ciocalteu reagent, were ranging from 46.39-82.19 mg GAE/100 g, 36.72-56.45 mg GAE/100 g, and 41.46-85.70 mg GAE/100 g for methanolic, acetone and ethanolic extract, respectively. The antioxidant activity of plant extracts as determined by DPPH scavenging assay were ranging from 0.69-2.14 mg/mL, 1.40-4.38 mg gallic acid/g, and 7.32-29.21 mg ascorbic acid/g when expressed as IC 50 , GEAC and AEAC, respectively. The highest antioxidant activity was observed in acetone extract of orange variety (PG 3). Therefore, each part of the PG 3, i.e. leaf, stem and flower was separated and further evaluated. The results showed that the leaf of PG 3 contained the highest phenolic content and antioxidant activity. The present study suggests that extracts from P. grandiflora could be utilised as natural sources for antioxidant.