• Applied Biological Chemistry
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• v.36 no.1
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• pp.33-37
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• 1993

Oxidations products of ${\alpha}-tocopherol$, ${\gamma}-tocopherol$ and ${\gamma}-tocotrienol$ in lipophilic reaction media were studied. ${\alpha}-Tocopherylquinone$, ${\gamma}-tocopherylquinone$ and ${\gamma}-tocotrienylquinone$ were fractionated using micro column, isolated and identified by HPLC and MS.

• Korean Journal of Food Science and Technology
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• v.35 no.3
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• pp.347-352
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• 2003

In order to compare quality characteristics and oxidative stabilities of rice germs prepared under different roasting conditions, sensory evaluation, color value, tocols (tocopherol+tocotrienol) contents, and peroxide value were investigated. Optimum roasting temperatures for the best acceptability were 20, 10, and 6 min at 170, 180 and 190, respectively. Hunter color a values of rice germ increased as roasting temperature and time increased, whereas L value decreased. Peroxide values of unroasted, and roasted rice germs at $170^{\circ}C$ for 20 min, $180^{\circ}C$ for 10 min, and $190^{\circ}C$ for 6 min were 2.0, and 145.6, 169.5, and 182.9 meq/kg, respectively, after 9 days storage at $60^{\circ}C$. Four tocopherol and three tocotrienol isomers were identified, whereas no ${\beta}$-tocotrienol was detected. The major tocopherol and tocotrienol isomers in rice germ were ${\alpha}$-tocopherol and ${\alpha}$-tocotrienol, respectively. ${\alpha}$-Tocopherol content in roasted rice germ decreased significantly during storage, whereas those of ${\beta}$- and ${\gamma}$-tocopherols slowly decreased. ${\delta}$-Tocopherol had the highest stability among tocopherol isomers in roasted rice germ. Similar trends were observed in tocotrienol isomers.

• Korean Journal of Plant Resources
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• v.20 no.2
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• pp.104-112
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• 2007

This study was carried out to investigate the effects of dietary tocotrienol extracted from the rice bran on hematological and histological changes of the mouse. The mice were divided into seven groups (basal diet, cholesterol diet, tocopherol diet, and 4 different tocotrienol diets), and bred for a month. Tocotrienol diet was shown to have decreasing effects of serum triacylglycerol and LDL concentrations, whereas serum HDL concentrations were increased by tocotrienol diet. But serum cholesterol concentration was not statistically significant among the diet groups. Tocotrienol diet was shown to have decreasing effects of serum AST activities (P=0.0548) and LDH activities (P=0.0016), which are the standard indicators for liver damages or myocardial infarction. And tocotrienol diet has reduced the fat bodies accumulated in liver and heart caused from administration of rice bran oil. Also, the effects were shown as concentration-dependent manners. In conclusion, dietary tocotrienol extracted from rice bran has evident effects to protect or reduce lipid accumulation from blood, hepatocytes and heart muscles. It is also suggested as a good fortifying nutrition for the health and medical care.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.49 no.6
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• pp.468-471
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• 2004

Tocotrienol $(T_3)$ and tocopherol (T) are well-known antioxidant vitamin E isomers that are enriched in rice bran, most of which is removed during polishing process. To verify the polishing-dependent fractional content of tocotrienol and tocopherol, harvested brown rice of 4 cultivars were polished by 4.0, 6.4, 8.0, 9.6, and $12\%$ (w/w) and resultant bran powder and rice were used for $T_3$ and T analysis. Polishing degree affected bran $T_3$ content in that bran polished by $6.4\%$ exhibited highest $T_3$ content compared to other polishing degrees except in cv. Chucheongbyeo which showed similar $T_3$ content from 4.0 to $8.0\%$ polishing. In case of tocopherol, bran polished by $8.0\%$ exhibited highest T content in all tested cultivars. In general, $T_3$ distributed in higher quantity in exterior i.e., in less polished bran, while T showed relatively less decrease with enhanced polishing degree. Consequently, total vitamin E content in bran as calculated by the summation of $T_3$ and T became less dependent on polishing degree in that bran polished between 6.4 to $9.6\%$ exhibited no statistical differences. The rice of cv. Chuchongbyeo, remained after polishing, exhibited similar vitamin E content up to $6.4\%$ polishing, above which significant vit E loss could be observed. These results suggest that polishing less than $6.4\%$ is desirable to minimize the loss of tocotrienols and tocopherols during polishing.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.49 no.3
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• pp.211-215
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• 2004

Near infrared reflectance spectroscopy (NIRS) is a rapid and accurate analytical method for determining the composition of agricultural products and feeds. This study was conducted to determine tocopherol and tocotrienol contents in rice bran by using NIRS system. Total 80 rice bran samples previously analyzed by HPLC were scanned by NIRS and over 60 samples were selected for calibration and validation equation. A calibration equation calculated by MPLS(modified partial least squares) regression technique was developed and coefficient of determination for tocopheyol and tocotyienol content were 0.975 and 0.984, respectively, in calibration sets. Each calibration equation was fitted to validation set that was performed with the remaining samples not included is the calibration set, which showed high positive correlation both in tocopherol and tocotrienol content file. This results demonstrate that the developed NIRS equation can be practically used as a rapid screening method for quantification of tocopherol and tocotrienol contents in rice bran.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.48 no.6
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• pp.469-472
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• 2003

The rice bran has been known to contain tocopherols and tocotrienols carrying antioxidant and cholesterol-lowing activities. The content of 8 isomers of vitamin E : $\alpha\textrm{-}$, $\beta\textrm{-}$, $\gamma\textrm{-}$, $\delta\textrm{-}$tocoperols (T) and tocotrienols ($\textrm{T}_3$) were extracted from 18 major rice varieties and quantified with an HPLC. Tested varieties exhibited T, $\textrm{T}_3$ and total vitamin E ($\textrm{TT}_3$) contents ranging 9.1-14.8, 22.4-37.1, 34.9-46.5 mg/100g with averages of 11.1, 28.0, 39.2 mg/100g, respectively. Among tested varieties, Seojinbyeo and Hwasungbyeo showed high T contents and Andabyeo, Damakum were high in $\textrm{T}_3$, and Andabyeo and Seojinbyeo were high in total $\textrm{TT}_3$ contents. Regardless of varieties, the average 8 isomer contents (in mg/100g) were in descending order of $\gamma\textrm{-}$$\textrm{T}_3$(17.9) ＞$\alpha\textrm{-}$$\textrm{T}_3$(8.8) ＞$\alpha\textrm{-}$T (7.8) ＞$\gamma\textrm{-}$T(2.6) ＞$\delta\textrm{-}$$\textrm{T}_3$ (0.9)＞$\beta\textrm{-}$T (0.7)＞$\beta\textrm{-}$$\textrm{T}_3$ (0.4)＞$\delta\textrm{-}$T (0.1). In most varieties, $\gamma\textrm{-}$$\textrm{T}_3$, a strong antioxidant and anticancer compound, consisted 64% of total tocotrienol and 46% of total vitamin E in vice bran.

• Korean Journal of Food Science and Technology
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• v.25 no.4
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• pp.307-312
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• 1993

Antioxdant effect was studied in model system with linoleic acid methylester and tocochromanols $({\alpha}-,\;{\beta}-,\;{\gamma}-,\;{\delta}-tocopherol\;and \;{\alpha}-,\;{\gamma}-,\;{\delta}-tocotrienol)$ under definite autoxidation condition-temperature $(40,\;60,\;80^{\circ}C),\;O_2\;(0,\;10,\;20%\;O_2\;in\;N_2)$. 13-Hydroperoxy-9-cis-11-trans-, 13-hydroperoxy-9-trans-11-trans-, 9-hydroperoxy-10-trans-12-cis-, 9-hydroperoxy-10-trans-12-trans-octadecadienoic acid methylester as the major oxidation product were produced from linoleic acid methylester by autoxidation, analyzed with HPLC and antioxidant activities were compared by their quantitative changes. Experimental results showed that all added tocochromanols except ${\alpha}-tocotrienol$ had antioxidant effect at $60^{\circ}C$, and also ${\alpha}-tocopherol$, ${\alpha}-tocotrienol$ and ${\delta}-tocotrienol$ had prooxidant effect at $80^{\circ}C$. And cis/trans-hydroperoxide was predominantly produced at $40^{\circ}C$, but trans/trans-hydroperoxide at $80^{\circ}C$. Except no reproductive experimental data in produced hydroperoxides amount, the production ratio of cis/trans-:trans/trans-hydroperoxides in the autoxidation condition of range from $40^{\circ}C/10%,\;O_2\;to\;60^{\circ}C/20%\;O_2$ were as follows: ${\alpha}-T>{\alpha}-T_3>{\gamma}-T>{\beta}-T>{\gamma}-T_3>{\delta}-T>{\delta}-T_3$. This result showed that ${\alpha}-tocopherol$ among tocochromanols had the lowest antioxidant effect.

• Journal of Nutrition and Health
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• v.43 no.3
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• pp.304-314
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• 2010

Vitamin E has been a generic term for all tocopherol and tocotrienol derivatives. The most active form of vitamin E isoforms in vivo is regarded to be $\alpha$-tocopherol which is the only form defined as vitamin E in the US Food and Nutrition Board, causing controversy over setting dietary reference intake (DRI) of vitamin E. However, most of the countries other than the US maintain the original concept that all isoforms are accepted as vitamin E but with different biopotency. The roles of the isoforms of vitamin E other than $\alpha$-tocopherol have received continuous attention. Among them those of $\gamma$-tocopherol and $\alpha$-tocotrienol have been most studied in comparison with $\alpha$-tocopherol, since $\gamma$-tocopherol comprises major form of vitamin E in many plant seeds and those of the both vitamin E have been implicated in unique physiological functions. This review summarizes findings that have led a better understanding of vitamin E absorption, transport, tissue storage and various functions common and specific to vitamin E isoforms focusing $\alpha$- and $\gamma$-tocopherol as well as tocotrienols. It is expected to help redefining vitamin E and setting its DRI for Koreans.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 2009.11a
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• pp.190-192
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• 2009

Kainic acid (KA), an agonist for kainate and AMPA receptors, is an excitatory neurotoxic substance. Vitamin E such as alpha-tocopherol and alpha-tocotrienol is a chain-breaking antioxidant, preventing the chain propagation step during lipid peroxidation. In the present study, we have investigated the neuroprotective effects of alphatocopherol and alpha-tocotrienol on KA-induced neuronal death using organotypic hippocampal slice culture (OHSC). After 15h KA treatment, delayed neuronal death was detected in CA3 region. Alpha-tocopherol and alpha-tocotrienol increased cell survival and reduced the number of TUNEL-positive cells in CA3 region. These data suggest that alpha-tocopherol and alpha-tocotrienol treatment have protective effects on KA-induced cell death

• Food Science and Biotechnology
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• v.15 no.2
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• pp.183-188
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• 2006

The tocopherol and tocotrienol contents of 39 vegetable oils, margarines, butters, and peanut butters typically consumed in the Korea diet were determined by direct solvent extraction method followed by normal phase liquid chromatography. All samples were locally obtained in the Cheongju area in 2003 and 2004. The study examined data on 19 vegetable oils, 10 margarines, 6 butters, and 4 peanut butters. ${\gamma}$-Tocopherol (${\gamma}$-T) and ${\alpha}$-tocopherol (${\alpha}$-T) were detectable in all products except butters and were usually present in the vitamin E form in greater quantity than the other isomers. Usually, ${\gamma}$-T content was higher than ${\alpha}$-T content in many samples. Tocotrienols were measurable in some samples but usually at levels less than the corresponding tocopherols. Three analytical method validation parameters, accuracy, precision, and specificity, were calculated to ensure the method's validity and were all confirmed to be reliable and satisfactory.