• Journal of Microbiology and Biotechnology
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• v.29 no.9
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• pp.1401-1411
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• 2019

Mycobacterial cell walls comprise thick and diverse lipids and glycolipids that act as a permeability barrier to antibiotics or other chemical agents. The use of OH radicals from a non-thermal plasma jet (NTPJ) for the inactivation of mycobacteria in aqueous solution was adopted as a novel approach. Addition of water vapor in a nitrogen plasma jet generated OH radicals, which converted to hydrogen peroxide ($H_2O_2$) that inactivated non-pathogenic Mycobacterium smegmatis and pathogenic Mycobacterium tuberculosis H37Rv. A stable plasma plume was obtained from a nitrogen plasma jet with 1.91 W of power, killing Escherichia coli and mycobacteria effectively, whereas addition of catalase decreased the effects of the former. Mycobacteria were more resistant than E. coli to NTPJ treatment. Plasma treatment enhanced intracellular ROS production and upregulation of genes related to ROS stress responses (thiolrelated oxidoreductases, such as SseA and DoxX, and ferric uptake regulator furA). Morphological changes of M. smegmatis and M. tuberculosis H37Rv were observed after 5 min treatment with $N_2+H_2O$ plasma, but not of pre-incubated sample with catalase. This finding indicates that the bactericidal efficacy of NTPJ is related to the toxicity of OH and $H_2O_2$ radicals in cells. Therefore, our study suggests that NTPJ treatment may effectively control pulmonary infections caused by M. tuberculosis and nontuberculous mycobacteria (NTM) such as M. avium or M. abscessus in water.

• Journal of the East Asian Society of Dietary Life
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• v.18 no.4
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• pp.499-506
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• 2008

The nutritional composition of the white lotus(Nelumbo nucifera Gaertn) leaf are moisture($1.87{\pm}0.06%$), crude ash($9.57{\pm}0.07%$), crude protein($15.53{\pm}0.4%$) and crude lipid($2.42{\pm}0.1%$) per 100g. The highest mineral content was K and Ca. The principal free sugars in the white lotus leaf was sucrose, fructose and glucose. The total phenolics compounds evidenced maximal levels of $8,842.73{\pm}20.57\;g/100g$. DPPH and hydroxyl radical of scavenging ability of each sample tended to increase with increasing degrees of the sample concentration. The $IC_{50}$ values of the ethanol extract, n-hexane, chloroform, ethylacetate, butanol and water fraction from the white lotus leaf to DPPH radicals were 5.65, 8.5, 8.27, 2.03, 2.3 and $13.7\;{\mu}g/mL$ respectively. The $IC_{50}$ values of the hydroxyl radical scavenging ability of the ethanol extract, ethylacetate, butanol and water fraction were 390, 574, 327 and $378\;{\mu}g/mL$ respectively.

• Preventive Nutrition and Food Science
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• v.14 no.2
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• pp.109-115
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• 2009

The principal objective of this study was to assess the radical scavenging activities and total polyphenols, flavonoids, and flavonol contents of takju, a Korean traditional rice wine. The antioxidant properties of the wine and takju samples were evaluated using five distinct assays: specifically, 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2-azino-di-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS); hydroxyl; superoxide anion; and nitric oxide (NO) radical-scavenging activity assays. In this study, the takju evidenced strong scavenging activities against the hydroxyl, superoxide anion, and NO radicals. Furthermore, the total polyphenol contents of T-2 were similar to those previously observed in white wine (p<0.05). However, the flavonoids and flavonol contents of all takju samples were significantly (p<0.05) lower than that of white wine. The results of this study show that takju possesses a powerful radical scavenging activity against a variety of oxidative systems. The findings of this study also indicate that takju should be considered a useful antioxidant, and that their functional compound reduces oxidative stress.

• Journal of Marine Bioscience and Biotechnology
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• v.7 no.1
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• pp.19-27
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• 2015

The objective of the current study was to evaluate the inhibitory and antioxidant activities of powdered katsuobushi (dried bonito) protein hydrolysates and their corresponding fractions. The powdered katsuobushi (dried bonito) hydrolysates were obtained by enzymatic hydrolysis using Alcalase, ${\alpha}$-chymotrypsin, Neutrase, pepsin, papain, and trypsin. The antioxidant efficacy of the respective hydrolysates were evaluated using 2,2-diphenyl-1-picrylhydrazyl (DPPH), hydroxyl, superoxide, and alkyl radical-scavenging activities. Among the hydrolysates, the peptic-derived hydrolysate exhibited the highest antioxidant activity compared to other enzymatic hydrolysates. Therefore, the peptic-derived hydrolysate was further analyzed, and was found to contain an active peptide with an amino acid sequence identified as Pro-Met-Pro-Leu-Asn-Ser-Cys (756 Da). The purified peptides from powdered katsuobushi (dried bonito) had an $EC_{50}$ value of $105.82{\mu}M$, and exhibited an inhibitory effect against DNA oxidation induced by hydroxyl radicals. Taken together, these results suggests that powdered katsuobushi (dried bonito) could be used as a natural antioxidant in functional foods and prevent oxidation reactions in food processing.

• Journal of Environmental Science International
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• v.29 no.8
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• pp.793-800
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• 2020

The conventional development of multi-component electrodes is based on the researcher's experience and is based on trial and error. Therefore, there is a need for a scientific method to reduce the time and economic losses thereof and systematize the mixing of electrode components. In this study, we use design of mixture experiments (DOME)- in particular a simplex lattice design with Design Expert^Ⓡ program- to attempt to find an optimum mixing ratio for a three-component electrode for the high RNO degradation; RNO is an indictor of OH radical formation. The experiment included 12 experimental points with 2 center replicates for 3 different independent variables (with the molar ratio of Ru, Ti, Ir). As the Prob > F value of the 'Quadratic' model is 0.0026, the secondary model was found to be suitable. Applying the molar ratio of the electrode components to the corrected response model results is an RNO removal efficiency (%) = 59.89 × [Ru] + 9.78 × [Ti] + 67.03 × [Ir] + 66.38 × [Ru] × [Ir] + 132.86 × [Ti] × [Ir]. The R² value of the equation is 0.9374 after the error term is excluded. The optimized formulation of the ternary electrode for an high RNO degradation was acquired when the molar ratio of Ru 0.100, Ti 0.200, Ir 0.700 (desirability d value, 1).

• Journal of Environmental Health Sciences
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• v.32 no.5 s.92
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• pp.446-450
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• 2006

In order to treat the wastewater containing organic compound, pre-treatment system connected with MSP(molecular separation process) was investigated. With the aim of selecting an optimum process of Fenton's oxidation, removal efficiency of each process in the optimum reaction condition was recommended. The $Fe/H_{2}O_{2}$(ferric sulfate to hydrogen peroxide)reagent is referred to as the Fenton's regent, which produces hydroxyl radicals by the interaction of Fe with $H_{2}O_{2}$. The powerful oxidizing ability and extreme kinetic reactively of the hydroxyl radical was well established. Increasing dosage of $Fe/H_{2}O_{2}$ increased removal efficiency as molar ratio of $Fe/H_{2}O_{2}$ between 0.2 and 2.5. Optimum dosage of molar ratio was 1. The removal efficiency for reaction condition was increased as pH decreased when the molar ratio of $Fe/H_{2}O_{2}$ was 1.7. Fenton's oxidation was most efficient in the reaction time 35 min for complex wastewater. Also, coagulation aid experiments using kaolin resulted in 3% of kaolin dosage.

• Fisheries and Aquatic Sciences
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• v.14 no.4
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• pp.243-249
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• 2011

Carotenoids were found in high levels in both muscle and tunic samples, with the highest and lowest values observed in March and January, respectively. The average values in muscle (GM) and tunic (GT) harvested in Geoje were 49.1 mg/100g and 56.7 mg/100g, respectively, whereas those in muscle (TM) and tunic (TT) harvested in Tongyeong were 42.0 mg/100g and 50.2 mg/100g, respectively. The total phenol contents of the tunic were not significantly different (P < 0.05) between sampling area and month. We investigated the antioxidative activities of the carotenoids against linoleic acid peroxidation [1,1-diphenyl-2-picrylhydrazyl (DPPH)] and hydroxyl radicals as well as their reducing power. The DPPH radical scavenging activity was 7.6-13.5% in GM, which is relatively weak, whereas it was 21.1-29.9% in GT, 9.6-12.4% in TM and 19.3-24.1% in TT. In comparison to ${\alpha}$-tocopherol, the carotenoids were found to have strong inhibitory effects against linoleic acid peroxidation, and exhibited strong hydroxyl radical scavenging activities and reducing power at 120 ${\mu}g/mL$ of each sample.

• Food Science and Biotechnology
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• v.14 no.5
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• pp.614-620
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• 2005

The antioxidative effect of Ecklonia cava, a brown marine alga, was investigated on radical scavenging, including 1,1-diphenyl-2-picrylhydrazyl (DPPH), and hydroxyl and alkyl radicals, using an electron spin resonance (ESR) technique, and on the inhibition of $H_2O_2$-induced DNA damage using comet assay. E. cava was enzymatically hydrolyzed with five food industrial proteases (Alcalase, Flavourzyme, Kojizyme, Neutrase and Protamex) to prepare water-soluble extracts. All the proteolytic hydrolysates exhibited strong dose-dependent radical scavenging activities (above 80%) at a concentration of $2.5\;{\mu}g/mL$. Kojizyme extract (obtained by proteolytic hydrolysation of E. cava with Kojizyme) showed the highest hydroxyl radical scavenging activity of around 98%. In addition, the $H_2O_2$-induced DNA damage was determined using a comet assay, which was quantified by measuring the tail length. Reduction of DNA damage increased with increasing concentrations of Kojizyme extract from E. cava. These results indicated that E. cava has a potential as a valuable natural antioxidative source.

• Food Science and Biotechnology
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• v.18 no.6
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• pp.1505-1510
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• 2009

Arginyl-fructose (AF) and arginyl-fructosyl-glucose (AFG) were chemically synthesized and purified. Their in vitro and cellular antioxidant activity was investigated using oxygen radical absorbance capacity (ORAC) and cellular antioxidant activity assay, respectively. The peroxyl radical scavenging activity of AF was much higher than that of AFG, which was in good agreement with their reduction capacity to donate electrons or hydrogen atoms. On the other hand, the hydroxyl radical scavenging activity of AF was weaker than that of AFG, which was consistent with their metal chelating activity, suggesting that AFG-$Cu^{2+}$ complex may be less redox-active than AF-$Cu^{2+}$ complex due to 1 glucose molecule attached. The cellular antioxidant activity of AF and AFG appeared to depend on both their permeability into cell membrane and the scavenging activity on peroxyl or hydroxyl radicals. These results indicate that AF and AFG, Maillard reaction products, may have a high potential as a material for the development of nutraceutical food with antioxidant activity.

• Archives of Pharmacal Research
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• v.28 no.10
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• pp.1122-1126
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• 2005

Tungtungmadic acid (3-caffeoyl-4-dihydrocaffeoyl quinic acid) is a new chlorogenic acid derivative that was isolated from the Salicomia herbacea. The structure of tungtungmadic acid was determined using chemical and spectral analysis. The antioxidant activity of tungtungmadic acid was evaluated using various antioxidant assays, including free radical scavenging, lipid peroxidation and hydroxyl radical-induced DNA strand breaks assays. Tungtungmadic acid ($IC_{50}\;=\;5.1\;{\mu}M\;and\;9.3\;{\mu}M$) was found to have higher antioxidant activity in the DPPH scavenging assay as well as in the iron-induced liver microsomal lipid peroxidation system. In addition, the tungtungmadic acid was also effective in protecting the plasmid DNA against strand breakage induced by hydroxyl radicals.