• Journal of the Korean Applied Science and Technology
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• v.5 no.1
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• pp.25-30
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• 1988

In order to develope the method of quantitative determination of lipid hydroperoxide in human blood serum, we tried the ferrothiocyanate method to total lipids extracted by Bligh-Dyer method and obtained the results as follows. 1. The maximum absorbance showed at the concentration of Mohr's solution, 0.127M at pH 1.70 and ammonium thiocyanate solution, 3.95M in the ferrothiocyanate method. 2. When hydrogen peroxide, cumene hydroperoxide, and oxidized linoleic acid were added to serum, and extracted them by Bligh-Dyer method to examine the extraction efficiency, we confirmed that cumene hydroperoxide and oxidized linoleic acid were extracted in $CHCI_3$ phase, and hydrogen peroxide in $MeOH-H_2O$ phase, respectively. 3. The concentration of lipid hydroperoxide of total lipids extracted from normal adult serum was $2.0{\times}10^{-5}M$, and increased proportionally the concentration of lipid hydroperoxide by increasing the amount of serum. 4. When we compared the total lipids extracted by Bligh-Dyer method and total lipids extracted after lipoprotein is precipitated by Yagi method in human blood serum, the concentration of lipid hydroperoxide was showed nearly the same value. From our results, we concluded that the concentration of lipid hydroperoxide in human blood serum could be determined quantitatively by ferrothiocyanate method.

• 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.

• Journal of Ginseng Research
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• v.13 no.2
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• pp.234-238
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• 1989

In the presence of a photosensitizer, rose bengal, phooxidatlon in serum total lipids has been studied and the effects of ginseng water extract and saponins on it have reviewed. In the presence of rose bengal, serum total lipids undergo photooxidation and produce lipid hydroperoxides. On the other hand, ginseng water extract and dial saponins largely inhibit photooxidation and decrease the amount of lipid hydroperoxides in serum total lipids.

• Food Science and Biotechnology
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• v.17 no.5
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• pp.1086-1091
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• 2008

The antioxidant activities of the extracts of dangyuja (Citrus grandis Osbeck) leaves were evaluated. The highest phenolic content was obtained from the ethyl acetate fraction (EF) (202.1$\pm$0.8 mg GAE/g dried extract) and it exhibited the highest 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging activity. The cytoprotective effects of EF on oxidative damage induced by tert-butyl hydroperoxide (t-BHP) in a human hepatoma cell line, HepG2 cells, were investigated to understand the intracellular antioxidant mechanisms. Treatment of HepG2 cells with EF prior to oxidative stress was found to inhibit reactive oxygen species (ROS) generation, lipid peroxidation, and DNA damage in a dose-dependent manner. Gas chromatography-mass spectrometry (GC-MS) studies on EF resulted in tentative identification of 19 compounds representing 94.3% of the total content. Taken together, these results demonstrated that EF has excellent antioxidant activities and thus dangyuja leaves have great potential as a source for natural antioxidant which can be applied in food products.

• Korean Journal of Food Science and Technology
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• v.44 no.5
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• pp.643-647
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• 2012

The antioxidant capacity of aloe vera gel (AG), aloe vera exudates (AE), and a low molecular filtrate of aloe vera gel (ALMF) prepared from aloe vera grown on Jeju Island, Korea was evaluated using 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azinobis-3-ethyl-benzothiazoline-6-sulfonic acid (ABTS), and oxygen radical absorbance capacity (ORAC) assays, and total phenolic content (TPC), and total flavonoid content (TFC) were determined. The phenolic compounds in aloe samples were analyzed. Antioxidant capacities in oil-in-water emulsions following riboflavin photosensitization were analyzed using lipid hydroperoxide. AE had significantly higher antioxidant capacity than that of the other samples based on the DPPH, ABTS, and ORAC assays (p<0.05). Lipid hydroperoxide values of 5 mg/mL for AG, AE, and ALMF were 521.78, 272.32, and 699.89 mmol/kg oil, respectively, whereas that of samples without aloe vera was 893.07 mmol/kg oil over 48 h. AE had higher TPC and TFC values. Aloesin and aloin were found in AE, whereas those compounds were only found in trace amounts in AG and ALMF.

• Clinical and Experimental Pediatrics
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• v.50 no.8
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• pp.746-752
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• 2007

Purpose : Total hydroperoxide (TH), free radical-mediated oxidation product can be used as a measure of free radical injury. The aim of the present study was to see if preterm newborns are at increased risk for oxidative stress compared with term newborns, and to determine whether oxidative stress during postnatal first 1 week is associated with clinical outcomes in preterm infants. Methods : Serum TH levels of preterm infants (n=39) were compared with those of term infants (n=24) on the postnatal day 1. Among the preterm infants, serum TH levels of uncomplicated group (n=23) were also compared with those of complicated group (n=16) who developed oxygen radical related diseases on the postnatal day 1 and 7. Retrospective analysis was performed to find out risk factors for oxygen radical injuries based on birth history, laboratory data, neuroimaging findings and clinical progress in two preterm groups. Results : Serum TH levels on postnatal day 1 were higher in the preterm infant group than the term infant group. Serum TH levels on postnatal day 1 in the complicated preterm infant group were significantly higher compared with uncomplicated group, but there was no significant difference in serum TH levels on postnatal day 7. Also, there was no significant difference in serum TH levels between uncomplicated preterm infants and term infants. Serum TH level on postnatal day 1 was independently associated with higher morbidity after adjusting for gestational age, Apgar score (5 min), arterial blood gas analysis. Conclusion : Complicated preterm newborns are at increased risk for oxidative stress compared with uncomplicated newborns and term newborns. Oxidative injury during the prenatal or postnatal day 1 is associated with adverse outcomes in preterm infants. Elevated TH levels on postnatal day 1 may have a value to predict clinical outcomes in preterm infants.

• Korean Journal of Plant Resources
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• v.23 no.5
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• pp.445-450
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• 2010

This study was carried out to investigate the antioxidative capacity of Ampelopsis brevipedunculata 95% ethanol extracts. The concentration of A. brevipedunculata extract at which DPPH radical scavenging activity was inhibited by 50% was 0.42 mg/mL as compared to 100% by pyrogallol as a reference. Total antioxidant status was examined by total antioxidant capacity against ABTS radical reactions. Total antioxidant capacities of A. brevipedunculata extract at the concentrations of 0.1 and 1 mg/mL were 0.65 and 3.71 mM Trolox equivalents, respectively. Oxygen radical absorbance capacities of A. brevipedunculata extract at the concentrations of 5 and $100\;{\mu}g/mL$ were 22.75 and $131.25\;{\mu}M$ gallic acid equivalents, respectively. Superoxide scavenging activities of A. brevipedunculata extract at the concentrations of 0.1 and 1 mg/mL were 27.7 and 56.0%, respectively. Total phenolic contents of A. brevipedunculata extract at the concentrations of 0.5 and 2.0 mg/mL were 0.55 and 2.06 mM gallic acid equivalents, respectively. A. brevipedunculata extract at the concentration of 0.1 mg/mL inhibited 0.2 mM and 0.5 mM tert-butyl hydroperoxide induced cyototoxicity by 36.2 and 23.3%, respectively, in HepG2 cell culture system. Thus strong antioxidant and cytotoxicity-inhibiting effects of A. brevipedunculata extract seem to be due to, at least in part, the prevention from free radicals-induced oxidation as well as high levels in total phenolic contents.

• Korean Journal of Plant Resources
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• v.24 no.4
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• pp.456-460
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• 2011

The objective of this study was to investigate the antioxidative capacity of Rhododendron brachycarpum 95% ethanol extracts. Total antioxidant status was examined by total antioxidant capacity against ABTS radical reactions. Total antioxidant capacities of R. brachycarpum extract at the concentrations of 0.2 and 1 mg/mL were 0.33 and 2.26 mM Trolox equivalents, respectively. Superoxide scavenging activities of R. brachycarpum extract at the concentrations of 0.2 and 1 mg/mL were 45.0 and 77.0%, respectively. Oxygen radical absorbance capacities of R. brachycarpum extract at the concentrations of 5 and 100 ${\mu}g/mL$ were 40.88 and 131.00 ${\mu}M$ Trolox equivalents, respectively. Total phenolic contents of R. brachycarpum extract at the concentrations of 0.2 and 1 mg/mL were 0.37 and 1.25 mM gallic acid equivalents, respectively. R. brachycarpum extract at the concentration of 0.1 mg/mL inhibited 0.2 mM and 0.5 mM tert-butyl hydroperoxide induced cyototoxicity by 52.1 and 30.3%, respectively, in HepG2 cell culture system. Thus, strong antioxidant and cytotoxicity-inhibiting effects of R. brachycarpum extract seem to be due to, at least in part, the prevention from free radicals-induced oxidation as well as high levels in total phenolic contents.

• Journal of Ginseng Research
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• v.24 no.1
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• pp.29-34
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• 2000

The effects of each component (water extracts, alcohol extracts, lipophillic extracts, total saponin, panaxadiol, panaxatriol) of red ginseng on the antioxidative enzyme activities were investigated in the liver in order to screen antioxidative components of red ginseng. 20∼25g ICR mouse which were pretreated with 50 mg/kg body weight of red ginseng component for 15 days. The ability of red ginseng component to protect against oxidative damage to the mouse liver was examined by determining the level of lipid peroxidation (MDA), hydroperoxide (H$_2$O$_2$) and the activities of superoxide dismutase (SOD), catalase. The hepatic total-SOD activity was highest in lipophilic extracts group and panaxadiol group next (p<0.01). The content of hepatic hydroperoxide was lowest in the order of panaxatriol group and alcohol extracts group (p < 0.01). The hepatic catalase activity in the liver was highest in order of lipophillic extracts group (p <0.01) and total saponin group (p<0.05). Finally the lipid peroxidation (MDA) level was lowest in lipophillic extracts group, alcohol extracts group and panaxadiol next (p <0.01). In conclusion, the order of effectiveness of antioxidants was to be lipophillic extracts>panaxadiol >total saponins.

• Korean Journal of Food Science and Technology
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• v.44 no.1
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• pp.100-105
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• 2012

Analysis of the various constituents and determination of biological activities in the different parts (root, stem, and leaf) of Allium victorialis var. platyphyllum were carried out. Potassium and calcium were detected in higher contents (mg/100 g fresh wt.) than other minerals. The total phenolic content (mg tannic acid eq./100 g dry wt.) decreased in the order of leaves ($792.7{\pm}16.6$) > stems ($160.3{\pm}6.8$) > roots ($101.5{\pm}2.7$), and the total flavonoid content (mg quercetin eq./100 g dry wt.) was as follows: leaves ($497.9{\pm}11.1$), roots ($35.7{\pm}0.4$), stems ($18.5{\pm}1.4$). DPPH radical-scavenging activity and inhibition activity against the formation of cholesteryl ester hydroperoxide in rat blood plasma was higher in the leaves than in roots and stems. Extracts of A. victorialis separated by parts displayed antimicrobial activity against Clostridium perfringens, Staphylococcus aureus, Listeria monocytogenes, Vibrio vulnificus, Vibrio parahaemolyticus, of which the strongest activity was against C. perfringens.