• Journal of Life Science
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• v.20 no.11
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• pp.1611-1616
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• 2010

The purpose of this research was to determine the effect of surfactant micelles on lipid oxidation in W/O/W multiple emulsions. The content of ferric irons and hydroperoxide in the continuous phase in W/O/W multiple emulsions was measured as a function of Brij micelle. The concentration of ferric iron and hydroperoxide in the continuous phase increased with increased storage time (1~6 days). Lipid oxidation rates, as determined by the formation of lipid hydroperoxides, TBARs and headspace hexanal, in the W/O/W multiple emulsions containing ferric iron decreased when 3% surfactant micelles were exceeded. These results indicate that excess surfactant micelles could alter the physical location and prooxidant activity of iron in W/O/W multiple emulsions.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2003.05b
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• pp.237-238
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• 2003

과산화수소와 organic peroxide는 대류권내 광화학반응에서 생성되는 중요 부산물이다. 이들은 대류권내의 OH와 HO$_2$ 라디칼의 농도를 지시하여 대기의 산화도를 나타내는 지시자가 된다. 이 라디칼들은 $O_3$를 생성하는데 필수적인 성분이므로, 대류권내 광화학 반응을 이해하기 위해서는 과산화수소의 농도와 분포를 이해하는 것이 필수적이다. 대기중의 hydroperoxide는 유리코일 내에서 포집 용액에 의해 포집된 후 HPLC 시스템의 postcolumn reactor에서 효소와 반응하여 형광을 띠게 되고, 형광검출기에서 검출된다. 이 모든 과정은 자동화되어 과산화수소의 실시간 관측 및 연속관측이 가능하게 되었다. (중략)

• Proceedings of the PSK Conference
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• 2002.10a
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• pp.288.3-289
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• 2002

Increasing evidence regarding free radical generating agents and inflammatory processes suggests that accumulation of reactive oxygen species can cause hepatotoxicity. A short-chain analog of lipid hydroperoxide, t-butyl hydroperoxide (t-BHP), can be metabolized to free radical intermediates by cytochrome P-450 in hepatocytes. which in turn can initiate lipid peroxidation, affect cell integrity and result in cell injury. (omitted)

• Analytical Science and Technology
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• v.11 no.6
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• pp.474-477
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• 1998

A simple and rapid method for preparation of standard phosphatidylcholine hydroperoxide (PCOOH) in chemiluminescence-HPLC assay (CL-HPLC) was developed using the rose bengal dependent spectrofluorometric oxidation. The concentration of obtained PCOOH was determined by FOX (ferrous oxidation-xylenol orange) assay and then subjected to a CL-HPLC system.

• Applied Chemistry for Engineering
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• v.21 no.3
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• pp.343-348
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• 2010

The surface of low density polyethylene (LDPE) film was oxyfluorinated under different reaction conditions to introduce hydroperoxide groups and change surface characteristics. Hydroperoxide functional groups created by oxyfluorination were used as active sites for graft polymerization with hydrophobic monomer, acryl amide (AM), and hydrophilic monomer, methyl methacrylate (MMA) to carry out the second modification of the LDPE film surface. The surface properties of the OFPE films and grafted OFPE films were characterized by 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging method, ATR-IR, contact angle measurement and DSC. From the results of DPPH method, the amount of hydroperoxide groups on the oxyfluorinated LDPE film continuously increased as the total pressure in the oxyfluorination and the partial pressure of fluorine gas increased. The water contact angle and surface free energy measurements showed that hydrophilic liquid (water) contact angle on LDPE film surface decreased with hydrophilic AM grafting and hydrophobic liquid (methylene diiodide) contact angle on LDPE film surface decreased with hydrophobic MMA grafting. These were attributed to AM or MMA monomer grafting and the wettability of LDPE filmsurface to hydrophilic and hydrophobic liquids were improved.

• 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

• Applied Biological Chemistry
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• v.47 no.1
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• pp.72-77
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• 2004

The purpose of this research was to determine the effect of phenol compounds from green tea leaves and surfactant micelles on lipid oxidation in com oil-in-water emulsion (O/W). The concentration of phenol and surfactant in continuous phase of the O/W with exceed Brij 700 and phenol compounds was measured. The particle size of O/W with phenol (100 ppm) increased with increasing added exceed surfactant $(0{\sim}2.0%)$ and the concentration of surfactant and phenols in the continuous phase higher than these of control. Lipid oxidation rates, as determined by the formation of lipid hydroperoxides and headspace hexanal, in the O/W emulsions containing phenol compounds (100 ppm) and exceed surfactant $(0{\sim}2.0%)$ decreased with increasing concentration of exceed surfactant. The ability of the phenol compounds and exceed surfactant to inhibit hydroperoxide and headspace hexanal producing as lipid oxidation in O/W was BHT>procyanidin B3-3-O-gallate> (+)-gallocatechin > (+)-catechin and 2% > 1 % > 0% of exceed surfactant. These results indicate that phenol compounds and exceed surfactant could alter the physical location of hydroperoxide in O/W.

• Preventive Nutrition and Food Science
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• v.12 no.3
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• pp.173-176
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• 2007

${\gamma}-Oryzanol$ is one of the chain breaking antioxidants. Both sterol (triterpene) and phenolic hydroxyl groups in the structure of ${\gamma}-oryzanol$ may be responsible for its antioxidative function. We hypothesize that ${\gamma}-oryzanol$ is more effective in preventing the autoxidation of polyunsaturated fatty acid (PUFA) than the synthetic phenolic compounds in an oil/water (O/W) emulsion system. The antioxidative effectiveness of different concentrations of ${\gamma}-oryzanol$ and synthetic antioxidants was evaluated at different incubation times (0, 4, 8, 16, and 32 h) by measuring both the formation of hydroperoxides and the decomposition product of hydroperoxides (hexanal) in each emulsion system. Overall, the order of effectiveness of various antioxidants for inhibiting the formation of hydroperoxide in the O/W emulsion was: ${\gamma}-oryzanol$> tert-butylhydroquinone (TBHQ)> butylated hydroxytoluene (BHT)> butylated hydroxyanisole (BHA). O/W emulsion with selective lower concentrations of ${\gamma}-oryzanol$ showed better effectiveness than that with higher concentration of synthetic antioxidants. However, the ability of both ${\gamma}-oryzanol$ and synthetic antioxidants to decompose hydroperoxide was similar. ${\gamma}-Oryzanol$ was more effective antioxidant than the synthetic phenolic compounds in preventing the formation of hydroperoxide in the O/W emulsion system.

• Journal of the Korean Applied Science and Technology
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• v.7 no.2
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• pp.55-61
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• 1990

To investigate the influence of saturated fats, ${\alpha}-linolenic$ acid, EPA and DHA on the lipid hydroperoxide concentration and fatty acid composition in liver microsomes and in plasma lipid of rabbits, the animals were fed on the perilla oil rich ${\alpha}-linolenic$ acid or sardine oil rich EPA and DHA diet for four weeks Were examined. The fatty acid composition of plasma lipid and liver microsomes of rabbits fed on the perilla oil diet was an accumulation of arachidonic acid(AA) 20:4 n-6, eicosapentaenoic acid(EPA) 20:5 n-3, and docosahexaenoic acid(DHA) 22:6 n-3, The fatty acid composition of plasma lipid and liver microsomes of rabbits fed on the sardine oil was an accumulation of ${\alpha}-linolenic$ acid(LNA) 18:3 n-3, and arachidonic acid(AA) 20:4. The p/s ratio of rabbits fed on the perilla oil diet changed from 7.4 to 2.27 for plasma lipid and 2.47 for liver microsomes. The concentration of lipid hydroperoxide was 3.48 nmol MDA/ml and 4.35 nmol MDA/ml for plasma lipid and liver microsomes, respectively, in perilla oil diet. The lipid hydroperoxide liver was 4.22 nmol MDA/ml and 67 nmol MDA/ml for plasma lipid and liver microsornes in sardine oil diet.

• Journal of the Korean Chemical Society
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• v.27 no.2
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• pp.142-149
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• 1983

Reaction of thianthrene cation radical perchlorate (1) with cumene (4), p-chlorocumene (2), and p-nitrocumene (3) hydroperoxides in acetonitrile at room temperature afforded, inter alia, thianthrene as a common product and 5-(4'-hydroxyphenyl) thianthrenium perchlorate (5) for 4, 5-(5'-chloro-2'-hydroxyphenyl) thianthrenium perchlorate (7) and 5-acetonylthianthrenium perchlorate (6) for 2 and 6 for 3, respectively. Stoichiometry of these reactions showed that 2 moles of 1 gave rise to 1mole of thianthrene and 1 mole of thianthrenium salt (or salts). Nucleophilic reactivity to 1 was found to be in the order of phenol > > p-chlorophenol ${\sim}$ acetone > > p-nitrophenol. Apart from acid-catalyzed heterolytic decomposition of hydroperoxides, small amount of homolytic decomposition products were found from 3 and 4.