• Food Science and Biotechnology
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• v.17 no.2
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• pp.295-301
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• 2008

In this study, the antioxidant activities of red pepper seed kimchi extracts were examined. The extracts were evaluated by various antioxidant assays that included determinations of total phenolic and flavonoid contents, DPPH radical scavenging, superoxide anion radical scavenging, nitric oxide scavenging, superoxide dismutase (SOD) activity, metal chelating activity, and reducing power. All the kimchi extracts showed strong antioxidant activities by the tested methods. The 7% red pepper seed kimchi that was fermented for 6 days possessed the highest activity according to the performed tests. Yet, the highest scavenging activity was exhibited against nitrite, by extracts from kimchi for 0 day of fermentation rather than 6 days. All the activities for the kimchi fermented for 0 day with the addition of 7% red pepper seed increased markedly with an increase in concentration. With the exception of metal chelating and SOD activities, for the antioxidant properties assayed, the red pepper seed kimchi extracts were found to be highly effective.

• Preventive Nutrition and Food Science
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• v.14 no.4
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• pp.277-282
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• 2009

The antioxidant potency of methanolic extract of Duchesnea indica (MDI; Indian strawberry) was investigated by employing various established in vitro systems, such as total phenolic content, 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging activity, reducing power assay, metal chelating assay, superoxide radical scavenging activity and protective ability of DNA damage and protein oxidation. MDI inhibited metal chelating by 75.57% at 2 mg/mL, scavenged 50% DPPH free radical at 29.13 ${\mu}$g/mL, and eliminated approximately 46.21% superoxide radical at the concentration of 1 mg/mL. In addition, MDI showed strong ability on reducing power, DNA damage protection and protein oxidation protection. Overall, results suggested that MDI might be beneficial as a potent antioxidant and effectively employed as an ingredient in food applications.

• Journal of Applied Biological Chemistry
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• v.53 no.1
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• pp.8-12
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• 2010

The antioxidant activity of hawthorn fruit (Crataegus pinnatifida Bunge var. typica Schneider) extracts was investigated by several in vitro antioxidants properties, including DPPH free radical scavenging activity, total phenolic and flavonoid contents, hydroxyl radical scavenging activity, reducing power activity, iron-chelating capacity and nitrite scavenging activity. Among the extracts in this study, the 70% EtOH extract showed higher antioxidant activity than the others. The $IC_{50}$ value of DPPH free radical scavenging activity was $99.26\;{\mu}g/mL$. Furthermore, the 70% EtOH extract also showed significantly high total phenolic and flavonoids contents and reducing power activity. However, the MeOH extract exhibited stronger effects on hydroxyl radical scavenging activity, iron-chelating capacity and nitrite scavenging activity. All the results implicated that, the hawthorn fruit may has the available potential to be utilize as a potential source of natural antioxidant.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2004.02a
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• pp.106-113
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• 2004

A major problem of nuclear energy is the production of radioactive wastes. Needs for more environmentally favorable method to decontaminate radioactive contaminants make the use of liquid/Supercritical $CO_2$ as a solvent medium. In removing radioactive metallic contaminants under $CO_2$ solvent, two methods - use of chelating ligands and that of water in $CO_2$ emulsion - are possible. In the chelating ligand method, a combination of ligands that can make synergistic effects seems important. We discuss about the properties of microemulsion formed by F-AOT. By adding acid in water core, decontamination of metallic parts, soils were possible.

• Journal of the Korean Applied Science and Technology
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• v.32 no.3
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• pp.363-371
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• 2015

n-Butanol and ethyl acetate extracts of thermal treatment yam (Dioscorea batatas $D_{ECNE.}$) belonging to the family Dioscoreaceae were measured for their radical scavenging activity and lipid peroxidation inhibition ability. In this study, ethyl acetate extract showed the most potent antioxidant activity evaluated by ferrous ion chelating activity and NO radical scavenging activity. Nevertheless, n-butanol extract was more effective in inhibiting linoleic acid peroxidation. A significant difference between n-butanol extract and ethyl acetate extract in nitrite scavenging activity ${\beta}$-carotene bleaching assays could not be found. Also, the results of this study showed that thermal treatment yam could be used as easily accessible source of natural antioxidants and as a possible food supplement.

• Journal of the Korean Chemical Society
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• v.39 no.5
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• pp.379-383
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• 1995

The elution behaviors of stannous ion by PSA(phenol sulfonic acid) as an eluent on chelating resin, Amberlite IRC-718 have been investigated. When 0.10 M stannous solution was adsorbed on the resin and eluted with various concentrations of PSA, the two peaks of stannous ion were appeared in the elution curve. These two peak areas were changed according to the PSA concentration. Using these results, the stability constant of the complex formation between Sn2+ and PSA was calculated. This value is 2.0 ${\times}$ 10-1.

• Advances in Traditional Medicine
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• v.7 no.2
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• pp.162-170
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• 2007

Woodfordia fruticosa Kurz. (Lythraceae), commonly known as Dhayero, is used in the treatment of various ailments in Nepal. In this study, the antioxidant capacity of crude extract and different polarity fractions of Woodfordia fruticosa flowers were assayed for their scavenging abilities against 1,1-diphenyl-2-picrylhydrazyl (DPPH) and nitric oxide radicals, competitive ${\beta}$-carotene bleaching, reducing power, metal chelating ability and total phenolic content. Crude extract and polar fractions showed stronger antioxidant capacity and contained very high level of total phenolics. They exhibited strong DPPH radical scavenging, nitric oxide scavenging and reducing power, medium ${\beta}$-carotene bleaching and poor metal chelating capacity. Positive correlation obtained between total phenolic content and antioxidant capacity assays, indicated the contribution of phenolics toards antioxidant capacity.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2001.09a
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• pp.103-106
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• 2001

A remediation technology consisting of biodegradation and a modified Fenton reaction was developed to degrade mixtures of polycyclic aromatic hydrocarbons (PAHs) at a former manufactured gas plant (MGP) site. The original Fenton reaction (i.e., $H_2O$$_2$ + Fe$^{2+}$) was modified to be biocompatible by using ferric ions and chelating agents such as catechol and gallic acid. The modified reaction was effective in degrading PAHs at near neutral pH and thus was compatible with biodegradation. By the combined treatment of the modified Fenton reaction and biodegradation, more than 98% of 2- or 3-ring hydrocarbons and between 70 and 85% of 4- or 5-ring compounds were degraded in the MGP soil, while maintaining its pH about 6.6.

• Journal of the Korea Institute of Military Science and Technology
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• v.11 no.5
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• pp.99-106
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• 2008

Metal ions such as Cu and Cr were extracted from the Cu, Cr and Ag impregnated active carbon by contacting the solid surfaces with supercritical carbon dioxide(Sc-$CO_2$) containing chelating agents. About 10g of the active carbon sample were loaded in a vertical tube extractor contacting with $CO_2$ flowing from the bottom of the tube for 6hrs. The ligands used were acetyl acetone(AA) and Cyanex-302(C-302). Water and methanol were used as entrainers to study the effect of co-solvent to $CO_2$. Experimental results showed that C-302 was more effective than AA in removing Cu with the maximum extraction of 42.0wt%, while 57.6wt% of Cr was extracted with AA from the sample.

• Fibers and Polymers
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• v.2 no.1
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• pp.135-139
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• 2001

Poly(hydroxamic acid) resin beads were prepared and complexed with various metal ions. We used IR spectroscopy to investigate the structure of metal complex. It proved that the products formed by introduction of metal ions gave stable and colored complex. It was found that the resin bead as synthesized would be a good column packing material for continuous extraction. Energy dispersive spectroscopy was use to study the distribution of metal ions in the resin matrix. It could be tentatively concluded that adsorption and diffusion of metal ions in the chelating resins mainly depended on the loading of the resin matrix which indicated interacting sites with metal ions.