• Journal of the Mineralogical Society of Korea
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• v.32 no.1
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• pp.63-69
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• 2019

The oxidation states of structural Fe in minerals reflect the paleo-depositional redox conditions for the biologically or abiotically induced mineral formation. Particularly, nano-scale analysis using high-resolution transmission electron microscopy (HRTEM) and electron energy loss spectroscopy (EELS) is necessary to identify evidence for the microbial role in the biomineralization. HRTEM-EELS analysis of oxidation states of structural Fe and carbon bonding structure differentiate biological factors in mineralization by mapping the distribution of Fe(II)/Fe(III) and source of organic C. HRTEM-EELS technique provides geomicrobiologists with the direct nano-scale evidence of microbe-mineral interaction.

• Journal of Life Science
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• v.15 no.2 s.69
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• pp.304-310
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• 2005

This study was carried out to investigate the effect of herbicide paraquat (1,1-dimethyl-4,4-bipyridilium dichloride) on the electron transport system of the cell. When actively growing cells of bacteria were exposed to the 1.0 mM paraquat, more than $50\%$ of the cells were killed at 0 hour. But specific activities of superoxide dismutase (SOD) were not changed at 0 hour of paraquat treatment. Oxido-reductions of NAD (H) by the suspension of bacterial membtane, rat mithochondria and NAD-dependent dehydrogenase were accelerated by paraquat treatment.

• Korean Journal of Food Science and Technology
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• v.22 no.3
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• pp.332-336
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• 1990

Antioxidative characteristics of freeze dried soybean sauce powder (SSP) on the oxidation reaction of linoleic acid mixture(LA) were evaluated by the determinations of peroxide formation, synergistic property, hydrogen donation and lipoxygenase activity. SSP was found to possess a considerable potentiality of antioxidant activity on the formation of hydroperoxides in the LA oxidation reaction system at $50^{\circ}C$ for 144hrs. This antioxidative effect was increased by the concentration from 0.02% to 0.5% of SSP in the reaction system. Under the condition of presence of ferric chloride (10 ppm) in the reaction system. appreciable effect of SSP on the synergistic antioxidation were observed. On the other hand, hydrogen donation property of SSP onto ${\alpha},\;{\alpha}'-diphenyl-{\beta}-picrylhydrazyl$ was found and inhibitory ability of SSP on LA oxidation was also shown in the reaction system of lipoxygenase-catalized oxidation.

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2003.05a
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• pp.119-120
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• 2003

식품에서 peptide는 영양, 맛 그리고 건강기능성에 영향을 미침으로써 식품에 매우 중요한 역할을 한다. 지질의 산화는 식품에 있어 색깔, 식품의 질, 향취 등을 나쁘게 하며 지질이 산화하게 되면 활성라디칼, 과산화물을 비롯하여 저분자 카르보널화합물 등 각종 활성화합물이 생성되는데 이들 활성화합물과 노화와는 밀접한 상관관계가 있다고 알려지고 있어 관심이 고조되고 있다. (중략)

• Journal of Life Science
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• v.3 no.1
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• pp.9-17
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• 1993

식물 특히, 우리가 섭취하고 있는 식품에 널리 존재하고 있는 phenolic compounds는 simple phenols과 phenolic acids, hydroxycinnamic acid derivatives 그리고 flavonoids 등의 세가지 종류들로 나누고 있다. 이들 물질은 일정수준의 항산화성, 항돌연변이원성, 항암성을 지니고 있다. 본 총설에서는 식물성 phenolic compounds의 특성, 산화작용과 항산화작용, phenolic compounds의 항산화 메카니즘, 그리고 식물성 phenolic compounds들의 항산화능 등에 대하여 차례로 살핀다. 특히, 우리가 일상적으로 섭취하고 있는 식품에서의 이들 물질과 그들의 항산화성에 대한 최근 연구결과들을 중심으로 고찰한다.

• KSBB Journal
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• v.19 no.2
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• pp.110-112
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• 2004

The in vitro cell regeneration, the noni extract was mixed into the dilute noni solution and the ability of ROS to degrade noni into H$_2$O$_2$ was measured spectrophotometically. H$_2$O$_2$ was used for producing reactive oxygen species (ROS) in this measurement.

• Journal of the Korean Society of Food Science and Nutrition
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• v.21 no.4
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• pp.381-385
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• 1992

The effect of antioxidant activity of soyasaponin on the liposomal phospholipid membrane were investigated by spectrophotometry. The oxidation index and oxidation rate of ${\alpha}-tocopherol$ containing egg phosphatidylcholine (EPC) liposomes were markedly decreased in the presence of soyasaponin relative to those of purephospholipid liposmes. ${\alpha}-tocopherol$ containing liposomes delayed the oxidation of liposomes. Especially soyasaponin stimulated the antioxidant activity of ${\alpha}-tocopheroal$ in liposomes. These results indicates that soyasaponin in liposomes had some additive effect on antioxidant of ${\alpha}-tocopherol$ toward liposomes.

• Proceedings of the Ginseng society Conference
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• 1984.09a
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• pp.113-118
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• 1984

The effect of the saponin fraction extracted from Panax ginseng C.A. Meyer on the antioxidant activity of ${\alpha}-tocopherol$ was investigated in vitro as well as in vivo. Microsomal preparation of albino rat (Sprague-Dawley, 180-200g) was incubated in the mixture containing NADPH, $Fe^{3+},$ ATP, ${\alpha}-tocopherol$ with and/or without ginseng saponin fraction for 30 minutes and the malondialdehyde formed was assayed and found that the saponin fraction stimulated the antioxidant activity of ${\alpha}-tocopherol$ cooperatively. It was also realized that the cooperative stimulation of the antioxidant activity of ${\alpha}-tocopherol$ was most eminent when the concentration of the saponin fraction was around $10^{-5}\%$ in the reaction mixture. Alcoholic suspension of ${\alpha}-tocopherol$ with and/or without ginseng saponin fraction was administered orally to rats in which the lipid peroxidation was induced by ethanol administration and the lipid peroxide contents of the liver were assayed at certain periods of time after ${\alpha}-tocopherol$ administration in this animal. It was reported that the saponin fraction stimulated the absorption of ${\alpha}-tocopherol$ in rats and this was confirmed again in the present work. From the previous work and present experimental results, it seemed that the saponin fraction accelerated the absorption of ${\alpha}-tocopherol$ and therefore stimulated the antioxidant activity of ${\alpha}-tocopherol$ more effectively in the animal body.

• Korean Journal of Microbiology
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• v.50 no.1
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• pp.22-26
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• 2014

Protocatechualdehyde (PA) is phenolic compound having antioxidative and antitumor activities. PA was purified from supernatant of Streptomyces lincolnensis M-20. In the presence of copper ion, PA acted as pro-oxidant. The antioxidant activity was assessed with the 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay, and the pro-oxidant effect of PA on DNA damage as pBR322 plasmid DNA-cleaving agents in the presence of Cu(II) ions was investigated. The involvement of reactive oxygen species (ROS) in the DNA damage was confirmed by the inhibition of the DNA breakage by using glutathione (GSH), specific scavenger of ROS. When the increase in ROS reaches a certain level (the toxic threshold), it may trigger cell death. The formation of the PA/Cu(II) chelate complex was confirmed by reaction with ethylenediamine-tetraacetic acid (EDTA), a well-known chelating agent for metal ions, by using UV/Vis spectroscopic analysis.

• Journal of the Korean Society of Food Science and Nutrition
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• v.21 no.1
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• pp.23-28
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• 1992

Starch solid model system was employed to investigate the effect of lipoxygenase, ${\beta}-carotene$, ${\alpha}-tocopherol$ and water activity on the oxidation of linoleic acid. The rate of oxidation of linoleic acid by lipoxygenase was increased with the increase in water activity, Addition of ${\beta}-carotene$ and ${\alpha}-tocopherol$ to this system has been shown to inhibit the oxidation of linoleic acid and ${\alpha}-tocopherol$ was more effective antioxidant than ${\beta}-carotene$. However, an increase in the concentration of ${\beta}-carotene$ was found to have a strong antioxidant effect in the solid model system. And also the antioxidative action of ${\beta}-carotene$ was increased with increasing water activity in this system.