Akademik Veri Yönetim Sistemi
Journal of Agricultural and Food Chemistry, cilt.49, ss.4083-4089, 2001 (SCI-Expanded)
The antioxidant activities, reducing powers, 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging
activities, amount of total phenolic compounds, and antimicrobial activities of ether, ethanol, and
hot water extracts of the leaves and seeds of Rumex crispus L. were studied. The antioxidant activities
of extracts increase with increasing amount of extracts (50-150 íg). However, the water extracts
of both the leaves and seeds have shown the highest antioxidant activities. Thus, addition of 75 íg
of each of the above extracts to the linoleic acid emulsion caused the inhibition of peroxide formation
by 96 and 94%, respectively. Although the antioxidant activity of the ethanol extract of seed was
lower than the water extract, the difference between these was not statistically significant, P >
0.05. Unlike the other extracts, 75 íg of the ether extract of seeds was unable to show statistically
significant antioxidant activity, P > 0.05 (between this extract and control in that there is no extract
in the test sample). Among all of the extracts, the highest amount of total phenolic compound was
found in the ethanol extract of seeds, whereas the lowest amount was found in the ether extract of
seeds. Like phenolic compounds, the highest reducing power and the highest DPPH scavenging
activity were found in the ethanol extract of seeds. However, the reducing activity of the ethanol
extract of seeds was 40% that of ascorbic acid, whereas in the presence of 400 íg of water and
ethanol extracts of seeds scavenging activities were about 85 and 90%, respectively. There were
statistically significant correlations between amount of phenolic compounds and reducing power
and between amount of phenolic compounds and percent DPPH scavenging activities (r ) 0.99, P
< 0.01, and r ) 0.864, P < 0.05, respectively) and also between reducing powers and percent DPPH
scavenging activities (r ) 0.892, P < 0.05). The ether extracts of both the leaves and seeds and
ethanol extract of leaves had shown antimicrobial activities on Staphylococcus aureus and Bacillus
subtilis. However, none of the water extracts showed antimicrobial activity on the studied
microorganisms.