• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2000.05a
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• pp.145-148
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• 2000

• Bulletin of the Korean Chemical Society
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• v.31 no.11
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• pp.3133-3138
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• 2010

The electrochemical properties of the liposoluble vitamin $K_1$ adsorbed on bare and lipid coated glassy carbon electrodes (GCEs) were studied in unbuffered and well buffered aqueous media. The reduction products of vitamin $K_1$ were characterized by employing cyclic voltammetry and the in situ UV-visible spectroelectrochemical technique. The radical species of vitamin $K_1$ cannot be observed at the bare GCEs in well buffered media. The formation of the anion radical of vitamin $K_1$ was observed in unbuffered solutions above pH 5.9 or at the lipid coated GCE in a well-buffered solution. UV-visible absorption bands of neutral vitamin $K_1$ were observed at 260 nm and 330 nm, and a band corresponding to the anion radical species was observed at 450 nm. The derivative cyclic voltabsorptometric (DCVA) curves obtained for electrochemical reduction of vitamin $K_1$ confirmed the presence of both neutral and anion radical species. The anion radical of vitamin $K_1$ formed at the hydrophobic conditions with phosphatidylcholine (PC) lipid coated electrode was stable enough to be observed in the spectroelectrochemical experiments.

• Applied Chemistry for Engineering
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• v.20 no.6
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• pp.593-602
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• 2009

For a long time, there is much interest in the superoxide anion radical as one of reactive oxygen species (ROS) not only in the basic research field of chemistry and physics but also in the life science (or biotechnology). Recently, it is becoming ever more vital since the toxic property of nanomaterials as well as advanced oxidation processes (AOP) frequently employed for controlling pollutants are connected with the formation of superoxide anion radicals. Despite many researches on superoxide anion radical, the quantitative information of its presence and its detailed reaction mechanism in aqueous environments remains largely unclear, causing the controversy and confusion. In this review paper, we attempted to summarize the physicochemical property, mechanisms, and applications of superoxide anion radical. In addition, we briefly incorporated the important application of superoxide anion radical in AOP, nanomaterials, and life science (or biotechnology).

• KSBB Journal
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• v.32 no.2
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• pp.140-145
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• 2017

The objective of this study was to compare antioxidant effects of different extracts of Salicornia bigelovii seed. DPPH radical scavenging activity, chelating activity of ferrous, superoxide anion radical-scavenging activity, hydroxyl radical scavenging activity, and contents of total polyphenol and flavonoid were measured for different extracts. Ethanol extract (10 mg/mL) was found to have the maximum DPPH radical scavenging and superoxide anion radical scavenging activities (65.26 and 62.36%, respectively). However, hot water extract (10 mg/mL) showed the highest hydroxyl radical scavenging and chelating activities (51.50 and 53.24%, respectively). Total phenolics and flavonoid contents in the ethanol extract were 522.8 and $480.35{\mu}g/mg$, respectively. They were 401.51 and $352.60{\mu}g/mg$, respectively, in the hot water extract. These results indicate that ethanol and hot water extracts of S. bigelovii seed have good potential to be used as a new source of antioxidants for functional foods, cosmetics, and pharmaceuticals.

• Food Science and Preservation
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• v.9 no.2
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• pp.253-259
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• 2002

The antioxidative and free radical scavenging activity of water extracts of dandelion were investigated. Antioxidative and radical scavenging activity were assessed by means of different tests; inhibition of peroxidation on linoleic acid model system, scavenging DPPH radical, scavenging of hydroxyl radical by chemiluminescence assay, scavenging of superoxide anion radical by EPR spectroscopy and scavenging of hydrogen peroxide. The leaf extract showed strong antioxidant activity in linoleic acid system. The antioxidant activity of water extracts of dandelion increased with increasing concentrations of extracts. The scavenging activity of the dandelion extracts, on inhibition of the DPPH radical, was related to the reaction time. Hydroxyl radical were generated by lenten reaction and dandelion extract was found to scavenge OH˙in a concentration-dependent manner. The water extract of leaf had effective scavenging activities on hydrogen peroxide and superoxide anion radical. From the these data, it is evident that water extract of dandelion leaf is an effective scavenger for OH˙, O$_2$¨, DPPH˙, hydrogen peroxide. And, the antioxidative effect observed is believed to be partly due to this radical scavenger activity.

• Korean Journal of Food Science and Technology
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• v.28 no.1
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• pp.184-189
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• 1996

A scavenger of superoxide anion radical which causes oxygen toxicity was isolated from Capsella bursa-pastoris, and its physicochemical properties were investigated. The scavenger was isolated and purified by solvent fractionation and liquid column chromatographies (Amberlite XAD-2, Sephadex LH-20, Bio gel P-2, ODS (silica gel with 100% octadecyl silanization)). An active compound of 0.25 g was finally isolated by Fast Protein Liquid chromatography (FPLC) from 100 g ethanol extract of Capsella bursa-pastoris. A 50% decrease of superoxide anion radical was obtained with the scavenger compound of 0.58 g. The compound was assumed to be a phenolic glycoside from its physicochemical properties.

• Journal of Photoscience
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• v.4 no.2
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• pp.31-34
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• 1997

The rapid and spontaneous interaction between superoxide anion radical and nitric oxide to yield the potent oxidants. peroxynitrite artion and peroxynitrous acid, was investigated in phorbol myristate acetate(PMA)-stimulated RAW264.7 macrophases by means of lucigenin- or luminol-enhanced chemiluminescence method. When RAW264.7 macrophages were stimulated by PMA. peroxynitrite-induced chemiluminescence was clearly observed. To prove observed chemiluminescencc due to the reaction between superoxide anion radical and nitric oxide produced by RAW264.7 macrophases, N-nitrosoglutathione (GSNO), a nitric oxide-releasing compound. superoxide dismutase(SOD), an enzyme removing superoxide anion radical by dismutating superoxide artion radical to hydrogen peroxide, and N-acethyl cysteine(NAC), a scarvenging reagent both superoxide artion radical and nitric oxide, were added in the cell system. Peroxynitrite- induced chemilumincscence was increased by exogenous addition of GSNO. whereas observed chemiluminescence was decreased by SOD and NAC. These results suggest that PMA-stimulated RAW264.7 macrophages produce both superoxide anion radical and nitric oxide to form peroxynitrite.

• Food Science and Preservation
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• v.18 no.5
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• pp.739-745
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• 2011

The major objective of this study was to investigate the antioxidant activities of methanolic extracts from different parts (flower, leaf stem, and root) of Chrysanthemum zawadskii by employing various in-vitro assay systems. The extraction yields from the flower, leaf stem, and root were 18.347, 12.93, and 11.33-----, respectively. The total polyphenol content was highest in the flower (17.16 mg/100 g) and lowest in the root (11.33 mg/100 g). The antioxidant activities were raised within creasing amounts of extracts, and the extracts from the flower showed the highest effect on the superoxide anion radical scavenging, metal chelating on ferrous ions and reducing power. In addition, the leaf stem also showed good antioxidant activity in various systems. These results suggest that the methanolic extracts from the flower and leaf stem possess excellent antioxidant activities and may thus serve as potential sources of natural antioxidants.

• Applied Biological Chemistry
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• v.47 no.1
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• pp.135-140
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• 2004

The antioxidant activities of 80% methanol extracts obtained from 118 medicinal plants were tested through the evaluation of DPPH and superoxide anion radicals scavenging activity. Methanol extracts of Sophora japonica (76.9%) and Camptotheca acuminata Dence (50.9%) were found to have more than 50% DPPH radical scavenging activity while those of Perilla frutescens (37.2%), Amomum costatum (34.9%), Prunus ansu (33.2%), Mentha arvensis (32.3%), Serratula koreana (32.2%), Eriobotrya japonica (30.5%), and Artemisia asiatica (30.5%) showed more than 30% scavenging activity. Even though all of the commercial antioxidants didn't show superoxide anion radical activity, Mentha arvensis (87.7%), Eriobotrya japonica (84.9%), Amomum costatum (82.9%), Camptotheca acuminata Dence (82.1%) showed more than 80% scavenging activity. Mentha arvensis, Eriobotrya japonica, Amomum costatum, Camptotheca acuminata Dence showed strong antioxidative activity in the both DPPH and superoxide anion radical scavenging activities.

• Journal of the Korean Society of Food Science and Nutrition
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• v.30 no.3
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• pp.421-425
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• 2001

Antioxidative effects of crude chlorophylls and carotenoids extracts from mustard leaf kimchi on the lipid peroxidation in rat liver homogenate, egg phosphatidyl choline (EPC) liposome and superoxide anion radical were examined. The extracts were found to inhibit the increase of the thiobarbituric acid (TBA) value and show the effect of antioxidative activity on the liposomal phospholipid membrane. The oxidation index of EPC liposome was markedly decreased in the prescence of the extracts. The antioxidative activity of the extracts from mustard leaf kimchi was not related with fermentation period of the kimchi. The extracts from mustard leaf showed the similar antioxidative activity of $\alpha$-tocopherol within in the given level of addition. However, the oxidation index. When the effect of the extracts from mustard leaf kimchi on free radical scavenging was observed by the determination of the superoxide anion radical scavenging activity, it had similar value to that of $\alpha$-tocopherol.