%0 Journal Article
%T Antioxidant activity and free radical-scavenging capacity of Gynura divaricata leaf extracts at different temperatures
%A Wan Chunpeng
%A Yu Yanying
%A Zhou Shouran
%A Liu Wei
%J Pharmacognosy Magazine
%D 2011
%I Medknow Publications
%X Background: Extraction temperature influences the total phenolic content (TPC), total flavonoid content (TFC) of medicinal plant extracts to a great extend. TPC and TFC are the principle activity constituents present in the plant. The effects of extraction temperature on TPC, TFC and free radical-scavenging capacity of Gynura divaricata leaf extracts are worth to study. Materials and Methods: Folin-Ciocalteu and aluminum chloride colorimetric assay were used to determine the TPC and TFC of Gynura divaricata leaf extracts at different temperatures. The antioxidant and free radical-scavenging activity were measured by 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2-azino-bis-(3-ethylbenzthiazoline-6-sulfonic acid (ABTS) and phosphomolybdenum methods. Results: TPC and TFC were significantly elevated with increasing extraction temperature (from 40ˇăC to 100ˇăC). However, TPC and TFC were not significantly different (P > 0.05) at the extraction temperatures 90ˇăC and 100ˇăC. Also, the extracts obtained at a higher temperature exhibited a significant free radical-scavenging activity compared with extraction at lower temperatures (P < 0.05). The TPCs (13.95-36.68 mg gallic acid equivalent/g dry material) were highly correlated with DPPH (R2 = 0.9229), ABTS (R2 = 0.9951) free radical-scavenging capacity, and total antioxidant activity (R2 = 0.9872) evaluated by phosphomolybdenum method. Conclusion: The TPC and TFC of G. divaricata leaf was significantly influenced by the extraction temperatures, which were the main antioxidant constituents present in the G. divaricata plant.
%K Antioxidant activity
%K extraction temperature
%K Gynura divaricata
%K total phenolic content
%K total flavonoid content
%U http://www.phcog.com/article.asp?issn=0973-1296;year=2011;volume=7;issue=25;spage=40;epage=45;aulast=Wan