• Plant Resources
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• v.8 no.2
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• pp.103-109
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• 2005

Lettuce (Lactuca sativa L.) is known to contain water-soluble substances that improve antioxidant status due to the richness in antioxidants. Greenhouse experiment was carried out under different shading conditions during spring lettuce growing season. Shade significantly reduced shoot weight, number of leaves and chlorophyll content, while it increased shoot length of lettuce plants. The antioxidant potential of the individual fraction was in order of n-butanol > ethyl acetate > water > n-hexane fraction, although was less than that of commonly used antioxidants, BHT and ascorbic acid. Fractions from lettuce plants dose-dependently increased DPPH free radical scavenging activity, in vitro test. By means of HPLC analysis, BuOH fraction of cultivar 'Hwahyang' (57.93 mg $100g^{-1}$) had the highest amount of antioxidant chi orogenic acid. Shading treatment increased average amount of chlorogenic acid of all cultivars in BuoH, EtOAc, hexane and water fractions by 33, 120, 144, and $58\%$, respectively. These results suggest that lettuce plants had potent antioxidant activity, and their activities were differently exhibited depending on cultivar and fraction.

• Journal of Food Hygiene and Safety
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• v.12 no.1
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• pp.1-8
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• 1997

This study was performed to evaluate the antioxidant activity of silymarin against human low density lipoproteins(LDL) oxidation. Silymarin extracted from Silybum marianum was successively purified with solvent fractionation and followed by silica gel column chromatography. The active substances were separated by HPLC and the isolated active substances, silymarin were identified by IR, NMR, GC-MS as silymarin. Silymarin inhibited at the 5 $\mu$M Cu2+-mediated oxidation of human low density lipoprotein (LDL) in a dose dependent manner. Silymarin completely inhibited LDL oxidation at 50 $\mu\textrm{g}$/$m\ell$ concentration. These findings suggest that silymarin may protect LDL against oxidation in atherosclerotic lessions.

• Proceedings of the Ginseng society Conference
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• 1998.06a
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• pp.57-62
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• 1998

We hypothesized the primary effect of ginseng was to protect cell membrane fatty acids from decomposition caused by free radicals. To confirm the antioxidant effect of ginseng, we measured the inhibitory effect on the formation of thiobarbituric acid-reactive substances, an indicator of lipid peroxidation, and evaluated the free radical scavenging effect of ginseng by electron spin resonance spectrometer, and gas chromatography. The results showed that thiobarbituric acid-reactive substances formed and the loss of arachidonic acid during lipid peroxidation, and that hydroxyl (-like) radical peak formed by the iron complex (ferric nitrilotriacetate, an known free radical generator in vitro) were completely inhibited by ginseng extract. This antioxidant effect of ginseng may be responsible for its wide pharmacological actions in clinical practice. As the free radical reactions in general are rapid and non-specific, ginseng seems to act as a normalizer, rather than a general tonic, at the stages of acute or chronic active phase of the various diseases.

• The Korean Journal of Food And Nutrition
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• v.20 no.4
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• pp.356-362
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• 2007

This study was carried to develop the new material of functional food which antioxidant of natural substances of sprouts. We compared antioxdiative activity and antioxidant substances exist in sprouts. Antioxidaive activities of sprouts were measured by total polyphenolic acid contents, electron donating activity(EDA), SOD-liked activity and hydroxyl radical scavenging ability. Total polyphenolic acid content was very higher in Rape sprouts extract(Rap) than other sprout extracts. Also Rape extract was showed the most excellent antioxdiative activity in SOD liked activity at 86.94%. The EDA was ordered Rape sprouts extract(Rap)>Tatsoi sprouts extract(Tat)>Broccoli sprouts extract(Bro)>Alfalfa sprout extract(Alf). Hydroxy radical scavenging ability was the most effective in Rape sprouts extract(Rap). Therefore we could be certain that Rape sprouts extract(Rap) was the most effective in antioxidative activity from sprouts.

• Journal of Life Science
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• v.9 no.1
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• pp.99-105
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• 1999

The aims of this studies were carried out to investigate the antioxidant activity on low density lipoprotein(LDL) using substances extracted from Bacillus sp. RH-5. The antioxidative substances produced extracellular in the culture broth by Bacillius sp. RH-S was obtained by elution of chloroform : methanol from silicagel column (80cm x100cm) chromatography. Band 4 eluted from fraction 3 by TLC was appeared at highest level of antioxidative activity using thiocyanate methed. Band 4 at a concentration of 100 or 200$\mu$g/$m\ell$ inhibited oxidation of LDL induced by the mouse transformed macrophage. According to IR. NMR or GC/MASS, the antioxidant substance was identified as 5-hydroxyindole.

• The Korean Journal of Food And Nutrition
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• v.24 no.3
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• pp.306-311
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• 2011

This study was performed to investigate the effect of Portulaca oleracea extract on the antioxidant and antimicrobial activities against Helicobacter pylori. The each solvent extracts prepared from Portulaca oleracea were investigated by measuring total phenolic compounds, electron donating ability, superoxide dismutase-like ability and thiobarbituric acid reactive substances The herb extractor extract yielded the highest content of total phenolic compounds(72.2 mg%). The electron donating abilities(EDA) of ethyl acetate and methanol extracts showed high antioxidant activity. The superoxide dismutase (SOD)-like abilities of ethyl acetate and petroleum ether extracts also showed some activity. The antioxidant activity of thiobarbituric acid reactive substances was not significant. The petroleum ether extract of Portulaca oleracea showed the highest antimicrobial activity at 10,000 ppm concentration.

• Korean Journal of Pharmacognosy
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• v.38 no.1
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• pp.31-36
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• 2007

In this study, we have investigated the antioxidant activities of the leaves of Smilax china Linne in order to find the antioxidant substances which has an scavenging effect of reactive oxygen species (ROS) from natural products. As a result, EtOAc and n-BuOH extracts of the leaves of Smilax china Linne exhibited potent antioxidant effect on various antioxidant experiment. The major components of antioxidant activity were isolated from EtOAc and n-BuOH extracts of the leaves of Smilax china Linne. Their structure of compounds were identified as kaempferol-7-O-${\alpha}$-L-rhamnopyranoside and kaempferol-3,7-O-${\alpha}$-L-dirhamnopyranoside by spectroscopic evidence, respectively. Antioxidant activities were observed in kaempferrol-7-O-${\alpha}$-L-rhamnopyranoside at 23 ${\mu}g$ and in kaempferol-3,7-O-${\alpha}$-L-dirhamnopyranoside at 27 ${\mu}g$ as concentration of DPPH 50% reduction.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.19 no.1
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• pp.1-9
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• 1986

In order to isolate and clarify the antioxygenic substances from the browning reaction products, the antioxidant activity of various amino acids and their browning reaction products were measured when they were reacted with xylose. Among nonpolar amino acids Met and Trp appeared to have stronger antioxidant effect than others. Most of polar and basic amino acids, however, did not have antioxidant activity. Ser and Cys showed a rather slight prooxidant effect. The browning reaction products of Trp and His had a higher level of antioxidant activity than that they were reacted as free amino acids. But the browning product of Met did not show the antioxidant activity. When all amino acids were divided on their polar characteristics, the higher optical density of the browning reaction products showed, the stronger antioxidant activity revealed.

• Preventive Nutrition and Food Science
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• v.7 no.3
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• pp.320-322
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• 2002

The antioxidative capacity of Monascus koji was studied in raw bologna-type sausage by measuring thiobarbituric acid reactive substances (TBARS) and peroxide values (POV) during storage at $25^{\circ}C$ for 7 days. The addition of 2% Monascus koji effectively inhibited lipid oxidation in the mixture without vitamin C and NaNO$_2$, evidenced by its prevention of an increase in TBARS and a significantly reduction in increases in POV. Monascus koji in raw minced processed meat significantly improved the shelf life of the food.

• Journal of Ginseng Research
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• v.14 no.3
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• pp.373-378
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• 1990

Free malonaldehyde was determined in nine kinds of ginseng polyacetylene-treated micro- some by HPLC analysis. Antioxidant activities of some phenolic compounds and ginseng saponin were also drtermined both by a new HVLC method and by THA method. A new HPLC system separaterl malonaldehyde at a retention time 5,6 min and showed a linear relationship between the peak are a and malonaldehyde concentration. Panaxnol showed the strongest activity among nine polyacetylenes and the addition of either chlorine or aletyl group reduced polyacetylene's own activity. Since C14-polyacetylenes such as panaxyne and panaxyne-epoxide had little or no antioxidant activities, S17-structure should be preserved to exert a radical-scvenging or trapping activity. The antioxidant activities of chlorogenic acid, ferulic acid and catechol were much weaker than those of C17-polyacetylenes. Ginseng saponin showed no antioxidant activity. Since TBA reactive substances and malonaldehyde contents were almost the same in peroxiedized microsome. TBA value seems a good indicator for lipid peroxidation in this particular Fe+3 ADP/NADPH system.