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Antioxidant and antimicrobial activities of Polygonum cognatum Meissn extracts
Author(s) -
Yıldırım Ali,
Mavi Ahmet,
Kara Ayşe Aydan
Publication year - 2002
Publication title -
journal of the science of food and agriculture
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.782
H-Index - 142
eISSN - 1097-0010
pISSN - 0022-5142
DOI - 10.1002/jsfa.1288
Subject(s) - chemistry , dpph , antioxidant , antimicrobial , gallic acid , linoleic acid , food science , ethanol , ascorbic acid , ether , scavenging , organic chemistry , fatty acid
The antioxidant activities, reducing powers, 2,2‐diphenyl‐l‐picrylhydrazyl (DPPH) radical‐scavenging activities, total phenolic compound contents and antimicrobial activities of ether, ethanol and hot water extracts of Polygonum cognatum Meissn were studied in vitro . The highest antioxidant activity was found in the water extract. However, there were no statistically significant differences among 15 µg ml −1 extract‐containing samples in linoleic acid emulsion (0.02 M , pH 7.0) during 120 h of incubation ( P > 0.05). The reducing power of the water extract was the highest, but its reducing power was markedly lower than that of ascorbic acid. The highest DPPH radical‐scavenging activity was found in the water extract, with 50% DPPH radical scavenging at a concentration of 100 µg ml −1 dried water extract, while at the same concentration of dried ethanol extract the value was 12%. Surprisingly, no DPPH radical‐scavenging activity was observed in the ether extract. The concentrations of phenolic compounds found were 0.48, 0.50 and 0.01 µg ml −1 gallic acid equivalent in 10 µg ml −1 water, ethanol and ether extracts respectively. The ether and ethanol extracts showed antimicrobial activity against Staphylococcus aureus and Bacillus subtilis . The water extract did not show antimicrobial activity against the studied micro‐organisms. © 2002 Society of Chemical Industry