• The Korean Journal of Food And Nutrition
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• v.8 no.2
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• pp.135-144
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• 1995

Lipid oxidation in foods produce the peroxidation products, toxic substance and rancidity odor. In vivo, lipid peroxidation by free radicals or molecular singlet oxygen cause such as a damage of DNA, cancer and aging. Accordingly, the development of new compound Inhibit lipid oxidation in foods and in vivo is very important. Antioxidants are generally used as a protection material of oxidation for a storage and preservation of foods. In terms of stability of foods and health for human, development of high effective antioxidants In a nature is required. In this point of view, this paper presents the research trends of a kind of natural antioxidative substances and its antioxidative activity.

• Journal of Ginseng Research
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• v.17 no.3
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• pp.232-235
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• 1993

We investigated the effect of antioxidants (ascorbate, glutathione, and sodium azide), which efEectively inhibited the chlorophyll bleaching of Panax ginseng CA Meyer under the high light intensity, treated by folilar wiping on the early stage of photosynthesis and transpiration of ginseng in the 5000 $\mu$mol photon.$m^{-2}$.$s^{-1}$. Ascorbate and glutathione, endogenous antioxidant, completely recovered ginseng from the photoinhibition, but sodium azide, synthetic quencher, showed negative effect. We assumed that endogenous antioxidants could be available to the protection of the leaf-burning phenomenon of ginseng.

• The Korean Journal of Food And Nutrition
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• v.10 no.4
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• pp.564-573
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• 1997

The addition of antioxidants to fats and oils is one of the most effective ways to prevent oxidation of lipids. The popularity of natural antioxidants has increased because of the possible toxicity of synthetic antioxidants. Common natural antioxidants, tocopherols, retard oxidation at ambient temperatures, but they are ineffective at retarding oxidation at frying temperatures. The need for the development of novel natural antioxidants which are effective at frying temperatures is obvious. Sterols present in vegetable oils and certain herbal plant extracts have been reported to have antioxidant properties. Some sterols have been shown to retard thermal changes at frying temperatures. All the sterol effective at preventing oxidation at frying temperatures have an ethylidene group in their side chain. These effects can be explained by the hypothesis that sterols with a structure that allows them to react with lipid free radicals to form relatively stable free radicals are effective as antioxidants. (Key words :natural antioxidants, sterols, ethylidene group, herbal plant extracts)

• Journal of the Korean Society of Tobacco Science
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• v.29 no.2
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• pp.90-97
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• 2007

This study was conducted to evaluate the effect of additives (antioxidants for free radicals reduction) in cigarette filter treated with various antioxidants (three types of proanthocyanidins and ascorbic acid) and various concentrations of ascorbic acid and loaded with activated carbon on the delivery of free radicals of mainstream smoke (MS) by ESR. Also, we analyzed Hoffmann's analytes andscavenger activity according to the storage time and in vitro cytotoxicity. The analysis of spin number of vapor and particulate phase free radicals in MS are decreased to $14{\sim}24\;%$ and $16{\sim}40\;%$, respectively. As aresult of antioxidant potential for inactivity of vapor and particulate phase free radicals, natural antioxidants were more effective than ascorbic acid. Based on the result of the analysis of Hoffmann's analytes for various antioxidantstreated cigarette filters during the smoking, cigarette filter treated with ascorbic acid showed the lower amount of the deliveries of hydroquinone, isoprene and quinoline in MS than those treated with the other antioxidants. In the significant t-test on the difference of the cytotoxicity among the various antioxidants treated-cigarette filters, there are no significant differences at the 95 % confidence level. Those results indicated that the antioxidants were useful for reducing free radicals in MS because of the fast reaction between antioxidant and free radicals.

• Nutritional Sciences
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• v.9 no.1
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• pp.48-54
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• 2006

Methods have been developed to evaluate the total antioxidant capacity of foods and plasma but limitations are associated with their ability to determine precisely the contribution of lipophilic antioxidants in a lipid milieu as well as interactions among them Thus, we modified the Oxygen Radical Absorbance Capacity (ORAC) assay to determine the peroxyradical scavenging ability of both hydrophilic and lipophilic compartments in plasma The hydrophilic ORAC assay was performed in a phosphate buffer system utilizing 2,2'-azobis (2-amidinopropane) dihydrochloride as a peroxyradical generator and fluorescein as the target The lipophilic ORAC assay was carried out in a dimethylsulfoxide :butyronitrile (DMSO/BN, 9:1 v/v) system using 2,2'-azobis (2,4-dimethyl valeronitrile) as a peroxyradical generator and BODIPY C11 581/591 as the target Analyses were conducted in bovine serum supplemented with water - and lipid - soluble antioxidants and in human plasma. Albumin (0.5$\sim$5 g/dL) and uric acid (0.1$\sim$0.5 $\mu$mol/L) increased hydrophilic ORAC values in a dose-dependent fashion ($R^{2}$=0.97 and 0.98, respectively) but had no impact on lipophilic ORAC values. $\alpha$-Tocopherol (15$\sim$200 $\mu$mol/L) increased lipophilic ORAC values in a dose-dependent fashion ($R^{2}$=0.94); neither $\alpha$-tocopherol nor $\beta$-carotene had an impact on hydrophilic ORAC values. However, addition of $\beta$-carotene at physiological concentration (0.23$\sim$1.86 $\mu$mol/L), either alone or in combination with other carotenoids, had no significant impact on lipophilic ORAC values. Thus, while assays of 'total antioxidant capacity' in biological matrices would be a useful research and clinical tool, existing methods are limited by the lack of complete responsiveness to the full range of dietary antioxidants.

• Journal of the Korean Chemical Society
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• v.6 no.2
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• pp.99-103
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• 1962

The usefulness of a propionylated paper chromatography to the identification of various insoluble organic antioxidants in rubber vulcanizates was studied. Purified commercial antioxidants and commercially mixed antioxidants could be identified by the propionylated paper chromatography. Antioxidants were identified by the propionylated paper chromatography from acetone extract of pure gum vulcanizates, which were either unaged or aged in Geer-Oven. The $R_f$ values from acetone extracts of vulcanizates were a little lower than those purified samples, but the colours and shapes of the spots support the identification. No spot could be obtained by the method from the aged vulcanizate containing antioxidant 200 (2,6 Di-tert-butyl-p-cresol). This indicates that the antioxidant was converted or decomposed to other compound after aging. It was concluded from the above results that the propionylated paper chromatography is useful to identify the antioxidants from vulcanizates and presents a key for elucidating the mechanism of the inhibition.

• Journal of Environmental Health Sciences
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• v.5 no.1
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• pp.21-24
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• 1978

This study was conducted to find out the co-operative effect of antioxidants (butyl hydroxy anisol, dibutyl hydroxy toluene, propyl gallate, dl-$\alpha$-tocopherol) and organic acid (citric acid, tartaric acid, succinic acid) on the stability of soybean oil by active oxygen method. The results obtained were summarized as follows: 1. When antioxidants and organic acid were used together, the antioxidants activity was more strong than antioxidants were used only. 2. The co-operative effect of citric acid for antioxydants was the strongest whereas succinic acid was the weakest. 3. The co-operative effect of phenolic antioxydants for organic acid was more strong than dl-$\alpha$-tocopherol.

• Elastomers and Composites
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• v.14 no.2
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• pp.83-102
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• 1979

The purpose of this dissertation is to study some of the vulcanization characteristics of rubber-bound antioxidants such as G-1, [N-(3-methacryloyloxy-2-hydroxypropyl)-N'-phenyl-p-phenylene diamine] and acryl, acrylamide & acrylester substituted hindered phenols. The influence of these antioxidants upon vulcanization characteristics in NR and SBR compounds in the presence of vulcanizing accelerators such as MSA, TT, DM, M & D was evaluated by means of Oscillationg Disk Cure Meter. The comparison was also made between the influence of rubber-bound antioxidants and that of conventional non-reactive antioxidants such as N-alkyl substituted PADA series. Regarding the influence of reactive type antioxidant G-1 mixed with accelerator TT upon vulcanization characteristics, rapid onset of vulcanization and higher degree of cross-linking were discovered, whereas in the case of accelerator M and DM, the result was slow onset of vulcanization and lesser degree of cross-linking. The comparison of vulcanizing characteristics among acrylic substituted hindered phenols as antioxidants was made under several vulcanization accelerator systems. Under such systems, MSA-S combined accelerator caused the onset of vulcanization to slow down and lowered the degree of cross-linking. Finally in the case of hindered phenol derivatives containing longer substituent, the delayed onset of vulcanization and the lowered degree of cross-linking could be discerned.

• Food Science and Biotechnology
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• v.18 no.4
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• pp.904-909
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• 2009

The beneficial effects derived from consuming natural antioxidants may not depend on the action of an individual antioxidant, but rather on the concerted action of several antioxidants naturally present. The aim of this study was to determine the concentrations and combinations of antioxidants that can produce synergistic effects (SyEs). Quantification of the lipoperoxyl radical scavenging capacity of antioxidants was carried out in a homogeneous model system where the free radicals were produced by the oxidation of methyl linoleate, initiated by the 2,2'-azobis (2,4-dimethylvaleronitrile). The greatest SyE (2.21, p<0.05) was seen in mixtures of all 4 antioxidants when used with concentrations of 15 ${\mu}M$ lycopene, 2.5 ${\mu}M$ vitamin E, 0.16 ${\mu}M$ vitamin C, and 10 ${\mu}M$ ${\beta}-carotene$. Doubling the vitamin E concentration from 2.5 to 5.0 ${\mu}M$ in the mixture with all 4 antioxidant reduced the SyE to 1.69 (p<0.05). Other combinations produced synergistic effects that ranged from 1.28 to 1.41.

• Proceedings of the KSAR Conference
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• 2001.10a
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• pp.47-47
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• 2001

One of the problems associated with in vitro culture of primordial germ cells (PGCs) is the large loss of cells during the initial period of culture. This study characterized the initial loss and determined the effectiveness of two classes of apoptosis inhibitors, protease inhibitors and antioxidants, on the ability of porcine PGCs to survive in culture. Results from electron microscopic analysis and in situ DNA fragmentation assay indicated that porcine PGCs rapidly undergo apoptosis when placed in culture. Additionally,？ 2-macroglobulin, a protease inhibitor and cytokine carrier, and N-acetylcysteine, an antioxidant, increased the survival of PGCs in vitro. While other protease inhibitors tested did not affect survival of PGCs, all antioxidants tested improved survival of PGCs (p〈0.05). Further results indicated that the beneficial effect of the antioxidants was critical only during the initial period of culture. Finally, it was determined that in short-term culture, in the absence of feeder layers, antioxidants could partially replace the effect(s) of growth factors and reduce apoptosis. Collectively, these results indicate that the addition of ？2-macroglobulin and antioxidants can increase the number of PGCs in vitro by suppressing apoptosis.