• Title/Summary/Keyword: oxygen scavenger

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Effect of Additives on Gamma Radiolysis of Methanol (메탄올의 감마선 분해에 대한 첨가물의 영향)

  • Choi, Sang-Up
    • Journal of the Korean Chemical Society
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    • v.14 no.3
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    • pp.237-242
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    • 1970
  • Effect of Added 1-hexene on the yield of hydrogen produced from Co-60 gamma radiolysis of methanol was investigated at room temperature. The results indicated that the yield of hydrogen decreased rapidly with increasing 1-hexene concentrations. Effect of added methyl borate on the radiolysis of methanol was also studied in the presence of oxygen. The results revealved that methyl borate acted as a less effective scavenger than oxygen towards the precursors of the radiolysis products. Experimental data previously obtained on the systems with oxygen added were treated more quantitatively to re-examine mechanism of the radiolysis of methanol in detail.

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Effects of Silk Fibroin on Oxygen radicals and Their Scavenger Enzymes in Brain of SD Rats (뇌조직의 활성산소 및 그 제거효소에 미치는 실크 피브로인의 영향)

  • 최진호;김대익;박수현;김정민;조원기;이광길;여주홍;이용우
    • Journal of Life Science
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    • v.10 no.4
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    • pp.340-346
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    • 2000
  • This study was designed to investigate the effects of silk fibroin(Mw 500) powder (SFP) on oxygen radicals and the scavenger enzymes in brain membranes of rats. Spragu-Dawley(SD) male rats(160${\pm}$10g) were fed basic diet(control group), and experimental diets(SFP-2.5 and SFP-5.0 groups) added 2.5 and 5.0g/kg BW/day for 6 weeks. Hydroxyl radical($.$OH) levels resulted in a decreases(6.6% and 9.7%, 2.8% and 11.9%, respectively) in brain mitochondria and microsomes of SFP-2.5 and SFP-5.0 groups compared with control group, but were significantly decreased in these membrances of SFP-5.0 group only. Superoxide radical (O2) levels were a slightly decreased (2.0% and 9.1%, respectively) in brain cytosol of SFP-2.5 and SFP-5.0 groups compared with control group. Lipid peroxide(LPO) levels were significantly decreased (12.9% and 21.9%, 13.2% and 22.5%, respectively) in brain mitochondria and microsomes of SFP-2.5 and SFP-5.0 groups compared with control group. Oxidized protein (OP) levels were significantly decreased (16.7% and 15.7%, respectively) in brain microsomes of SFP-2.5 and SFP-5.0 group compared with control group, but significantly difference between in brain mitochondria of these two groups could not be obtained. Mn-SOD activities were remarkably increased (11.2% and 24.2%, respectively) in mitochodria of SFP-2.5 and SFP-5.0 groups. CuZn-SOD activities were effectively increased (7.7% and 19.6%, respectively) in brain cytosol of SFP-2.5 and SFP-5.0 groups, but significant difference between control and SFP-2.5 groups could be not obtained. GSHPx activities were considerably increased (5.3% and 11.7%, respectively) in brain cytosol of SFP-2.0 and SFP-5.0 groups compared with control group. There results suggest that anti-aging effect of silk fibroin may play an effective learning and memory role in a attenuating a oxidative stress and increasing a scavenger enzyme activity in brain membranes.

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Effect of Silk Fibroin on Oxygen Radicals and Their Scavenger Enzymes in Liver of SD Rats (간장조직의 활성산소 및 그 제거효소에 미치는 실크 피브로인의 영향)

  • 최진호;김대익;박수현;김정민;조원기;이광길;여주홍;이용우
    • Journal of Life Science
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    • v.10 no.6
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    • pp.577-583
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    • 2000
  • This study was designed to investigate the effect of silk fibroin (Mw 500)power (SFP) on oxygen radicals and their scavenger enzymes in liver membranes of rats. Sprague-Dawley (SD) male rats (160$\pm$10 g) were fed basic diet (control group), and experimental diets (SFP-2.5 and SFP-5.0 groups) added 2.5 and 5.0 g/kg BW/day for 6 weeks. Hydroxyl radical (.OH) levels resulted in a considerable decreases (5.8% and 8.4%, 3.7% and 11.1%, respectively) in liver motochondria and micorsomes of SFP-2.5 and SFP-5.0 groups compared with control group, and $O_2$radical level was remarkably decreased about 15% and 20% in liver cytosol of SFP-2.5 and SFP-5.0 groups compared with control group. Lipid peroxide (LPO) levels were significantly decreased (8.3% and 18.0%, 13.4% and 18.4%, respectively) in liver mitochondria and microsomes of SFP-2.5 and SFP-5.0 groups compared with control group. Oxidized protein (OP) levels were remarkably decreased about 11.6% in liver mitochondria of SFP-5.0 group compared with control group. Mn-SOD activities were remarkably in creased (17.6% and 28.8%, respectively) in mitochondria of SFP-2.5 and SFP-5.0 groups, and Cu/Zn-SOD activities were also effectively in creased (about 14.4%) in liver cytosol of SFP-5.0 groups, but significant difference between GSHPx activity in liver cytosol of these two groups could be not obtained. These results suggest that anti-aging effect of silk fibroin may play an effective anti-aging role in a aattenuating a oxidative stress and increasing a scavenger enzyme activity in liver membranes.

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Effects of Silkworm (Bombyx mori L.) Powder on Oxygen Radicals and Their Scavenger Enzymes in Liver of SD Rats (간장조직의 활성산소 및 그 제거효소에 미치는 누에(Bombyx mori L.) 분말의 영향)

  • 최진호;김대익;박수현;김정민;조원기;이희삼;류강선
    • Journal of Life Science
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    • v.10 no.4
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    • pp.347-353
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    • 2000
  • This study was designed to investigate the effects of silkworm (Bombyx mori L.) powder (SWP) on oxygen radicals and their scavenger enzymes in liver membranes of rats. Sprague-Dawley(SD) male rats(160$\pm$10g) were fed basic diet (control group), and experimental diets(SWP-200 and SWP-400 groups) added 200 and 400 mg/kg BW/day for 6 weeks. Hydroxyl radical (.OH) levels resulted in a consistent decreases (4.0% and 7.2%, 5.0% and 14.1%, respectively) in liver mitochondria and microsomes of SWP-200 SWP-400 groups compared with control group, and O2 radical level was significantly decreased about 12% in liver cytosol of SWP-400 group compared with control group. Lipid peroxide(LPO) levels were significantly decreased (14.4% and 9.1%, respectively) in liver mitochondria and microsomes of SWP-400 group only compared with control group. Oxidized protein (OP) levels were remarkably decreased about 12.7% and 16.3% in liver microsomes only of SWP-200 and SWP-400 groups, but significant difference between liver mitochondria could not obtained. Mn-SOD activities were remarkably increased (15.8% and 25.2%, respectively) in mitochondria of SWP-200 and SWP-400 groups, but significant difference between Cu, Zn-SOD activities in these group could be not obtained. GSHPx activity was significantly increased in liver cytosol of SWP-400 group compared with control group. These results suggest that silkworm powder may play an effective role in a attenuating a oxidative stress and increasing a scavenger enzyme activity in liver membranes.

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Effect of Subfractions of Carthamus tinctorius L. Semen on the Lipid Peroxidation and Oxygen Free Radical Scavenging Enzyme Activities in CCl_4$-induced Hepatotoxic Rats (홍화자 분획물의 사염화탄소 유발 간손상 흰쥐에서 지질과산화와 oxygen free radical 제거 효소 활성도에 미치는 영향)

  • 정기화;정춘식;정정숙
    • Journal of Food Hygiene and Safety
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    • v.14 no.2
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    • pp.179-185
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    • 1999
  • Previous studies have shown that methanol extract and its butanol fraction of Carthamus tinctorius L. Semen have the hepatoprotective effect on the CCl4-induced hepatotoxicity. The hepatoprotective effect of the subfractions of butanol fraction has been evaluated by analyzing oxygen free radical scavenging enzyme activities and histopathological examinations. In BS-5 subfraction treated group, the activity of superoxide dismutase has been significantly increased as compared with that of CCl4, treated rats. Antioxidant activity has been evaluated by the examination of the scavenging activity against 1,1-diphenyl-2-picrylhydrazyl radical. BS-5 subfraction has shown strong antioxidant activities. The histopathological examination showed that the treatment of BS-5 subfraction has relieved the ballooning degeneration of hepatocytes which had been generated by CCl4. It appears that the protective effect of BS-5 subfraction would be mediated of the attenuation of lipid peroxidation by acting as a free radical scavenger, which were based on the increase of superoxide dismutase activity.

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Effects of Silk Fibroin Powder on Oxygen Radicals and Their Scavenger Enzymes in Serum of Rats (실크 피브로인 분말이 혈청중의 활성산소 및 제거효소에 미치는 영향)

  • 최진호;김대익;박수현;김동우;이종수;이용우
    • Journal of Sericultural and Entomological Science
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    • v.41 no.3
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    • pp.216-221
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    • 1999
  • This study was designed to investigate the effects of silk fibroin powder on oxygen radicals and their scavenger enzymes in serum of rats. Sprague-Dawley(SD) male rats (160${\pm}$10 g) were fed experimental diets (SFP-2.5 and SFP-5.0 groups)added 2.5 and 5.0 g/kg BW/day for 6 weeks. Triglyceride levels were remarkably inhibited (15∼25%) in SFP-2.5 and SFP-5.0 groups compared with control group. Hydroxyl radical ($.$OH) formations resulted in a marked decrease (15%∼25%) compared with control group, while superoxide radical and hydrogen peroxide formations resulted in a significant decrease (6∼12% and 10%). Lipid peroxide and oxidized protein (>C=O group) productions resulted in a significant decrease (6∼12% and 6%) compared with control group. Superoxide dismutase (SOD) and catalase (CAT) activities were remarkably increased (35∼55% and 40∼50%), but glutathione peroxidase (GSHPX) activities were significantly increased (13%) compared with control group. These results suggest that anti-aging effect of silk fibroin powder (SFP) may play a pivotal role in attenuating a various age-related changes.

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Effects of an In-package Oxygen Scavenger on the Stability of Deep-fried Instant Noodle (인스탄트 라면의 안정성(安定性)에 대한 탈산소제(脫酸素劑)의 효과(效果))

  • Ma, Sang-Jo;Kim, Dong-Hoon
    • Korean Journal of Food Science and Technology
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    • v.12 no.4
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    • pp.229-234
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    • 1980
  • Deep-fried instant noodle was prepared on a laboratory scale (150 units). A part of the noodle was packed in gas-proof laminated film bags with a small package of an oxygen scavenger made from Fe-powder and a 150 ml of air in each bag(Sample 1). Another part was packed in ordinary laminated film bags (Control), and the rest was vacuum-packed (74 mmHg) in the gas-proof film bags (Sample 2). All samples were placed in an incubator kept at $45.0{\pm}0.5^{\circ}C$ for 45 days. Oxygen-removing power of the scavenger, and peroxide and thiobarbituric acid values of the samples were determined regulary. The results of the study are as follows: 1. The residual oxygen concentration of the bags in Sample 1 decreased from the original 21% to less than 0. 5% after 48 hr. 2. POVs of Control, Samples 1 and 2 after 45 days were $12.4{\pm}0.4$, $5.7{\pm}0.2$ and $6.8{\pm}0.1\;meq/㎏$ fat respectively. It was noteworthy that the POV of Sample 1 did not change significantly during the storage period. The scavenger seemed very effective in retarding the POV development of Sample 1. 3. TBA values of Control, Sample 1 and 2 after 45 days were $1.31{\pm}0.04$, $0.60{\pm}0.04$, and $0.72{\pm}0.07$. As in the case of POVs, the samples packed with the scavengers exhibited consistently smaller TBA values than the vacuum-packed samples in later stages of the storage period.

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Mechanism of Photodynamic Therapy using 9-hydroxypheophorbide-alpha on HeLa Cell Lines

  • Ahn, Jin-Chul
    • Biomedical Science Letters
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    • v.15 no.2
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    • pp.153-160
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    • 2009
  • Photodynamic therapy(PDT) is a treatment utilizing the generation of singlet oxygen and other reactive oxygen species(ROS), which selectively accumulate in target cells. The aim of present work is to investigate the photodynamic therapy mechanism of 9-HpbD-a-mediated PDT in HeLa cell lines. We studied the general reactive oxygen species(G-ROS) activation after 9-HpbD-a PDT using fluorescence stain with $H_2DCF-DA$. G-ROS activation observed after 9-HpbD-a PDT and higher activation condition was 1 hour after PDT at 0.5 ${\mu}g/ml$ 9-HpbD-a concentration. Sodium azide and reduced glutathione(the singlet oxygen quencher) could protect HeLa cells from cell death induced by 9-HpbD-a PDT. But D-mannitol(the hydroxyl radical scavenger) could not protect cell death. Singlet oxygen played a decisive role in 9-HpbD-a PDT induced HeLa cell death. Type II reaction was the main type of ROS formation at 9-HpbD-a PDT.

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Identification of the Strain JM-4151 Producing Nonactin, as Radical-producing Antibiotic

  • Lee, Jin-Man;Lee, Dong-Sun;Hong, Soon-Duck
    • Journal of Life Science
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    • v.9 no.2
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    • pp.1-4
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    • 1999
  • Nonactin, as a radical-producing antibiotic, was isolated from the cultural broth of the strain JM-4151. This strain was identified as Streptomyces viridochromogenes and designated S. viridochromogenes JM-4151. The antibacterial activity of nonactin against Bacillus subtilis was antagonized by the activity opf quercetin, an oxygen radical scavenger. This result suggests that oxygen radical formation might be the cause for the antibacterial activity of nonactin.

Decrease of Membrane Degradation in PEMFC by Fucoidan (후코이단에 의한 PEMFC 고분자막의 열화 감소)

  • Oh, Sohyung;Kak, Ahyeon;Oh, Sungjun;Lee, Daewoong;Na, Il-Chai;Park, Kwonpil
    • Korean Chemical Engineering Research
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    • v.58 no.1
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    • pp.59-63
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    • 2020
  • Radical scavenger is used to improve the durability of PEMFC polymer membrane. In this study, we investigated whether fucoidan extracted from seaweed as a radical scavenger prevents electrochemical degradation through Fenton and OCV Holding experiments. Fucoidan has an antioxidant effect, protecting the polymer membrane from hydrogen peroxide and oxygen radicals, reducing the degradation rate to 1/10. Fucoidan has been shown to be more effective than MnO2, which is used as a radical scavenger. In the PEMFC cell, the accelerated durability evaluation method (OCV Holding) showed that fucoidan reduced the hydrogen permeability of the polymer membrane by 12% and enhanced the performance by 29.1% compared to without radical scavenger. And fucoidan was found to be more effective in the cathode side ionomer than the anode side.