• Nutrition Research and Practice
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• v.3 no.2
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• pp.77-83
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• 2009

Retinoic acids (RAs) modulate growth, differentiation, and apoptosis in normal, pre-malignant & malignant cells. In the present study, the effects of RA isomers (all-trans RA, 13-cis RA, and 9-cis RA) on the cell signal transduction of human breast cancer cells have been studied. The relationship between RAs and an enzymatic antioxidant system was also determined. Estrogen-receptor (ER) positive MCF-7 and ER-negative MDA-MB-231 human breast cancer cells were treated with different doses of each RA isomers, all-trans RA, 13-cis RA, or 9-cis RA. Treatment of RA isomers inhibited cell viability and induced apoptosis of MCF-7 cells as a result of increased caspase activity in cytoplasm and cytochrome C released from mitochondria. All-trans RA was the most effective RA isomer in both cell growth inhibition and induction of apoptosis in MCF-7 cells. However, no significant effect of RA isomers was observed on the cell growth or apoptosis in ER-negative MDA-MB-231 cells. In addition, activities of antioxidant enzymes such as catalase and glutathione peroxidase were decreased effectively after treatment of RA in MCF-7 cells, whereas SOD activity was rarely affected. Thus, the present data suggest that all-trans RA is the most potential inducer of apoptosis and modulator of antioxidant enzymes among RA isomers in MCF-7 human breast cancer cells.

• Bulletin of the Korean Chemical Society
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• v.30 no.5
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• pp.1127-1130
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• 2009

The effects of different dihydroxybenzoic acid (DHB) isomers, when used as matrix materials in matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS), were investigated in analyses of polyethylene glycol (PEG) polymers. PEG polymers ranging from 400 to 8,000 Da were prepared in different DHB isomer matrices using solvent-based and solvent-free methods. PEG samples were detected only in matrices of 2,3-DHB, 2,5-DHB, and 2,6-DHB while the most intense peaks were observed using 2,6-DHB in both solvent-free and solvent-based preparations.

• Korean Journal of Pharmacognosy
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• v.27 no.1
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• pp.20-25
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• 1996

In searching for anticomplementary compounds, three phenylpropanoids were isolated from the roots of Agastache rugosa and identified as rosmarinic acid (RA), rosmarinic acid methyl ester (RAM) and caffeic acid methyl ester (CAM) by NMR analyses. RA and RAM exhibited strong inhibitory activity on both the classical pathway (CP) and the alternative pathway (AP) of the complement system, in vitro, but CAM did far less than RA and RAM. $RAM-M1{\sim}-M5$, the methylated derivatives from the RAM, showed that the inhibitory activity was decreased in inverse proportion to the number of methylated groups and $RAM-M 2{\sim}-M4$, the isomers of two methylated hydroxyl groups, exhibited different inhibition activity.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.293-293
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• 2017

The objective of this study was to determine physicochemical changes in brown rice during ageing condition. Five varieties (Haiami, Ilpum, Daecheong, Jungwon, and Dasan1) of brown rice were stored at $35^{\circ}C$ for 8 weeks. Crude protein and lipid content, seed germination rate, fat acidity, tocol content, TOYO glossiness value, pasting properties, and composition of storage proteins were measured to evaluate its quality during storage. The isomers of tocols (tocopherol and tocotrienols) were quantified using HPLC system, and the pattern of variation in rice storage proteins was examined through electrophoresis of protein extracts. Seed germination rate decreased by 2.7 times, whereas the fatty acid value dramatically increased by 4.8 times after 8 weeks of storage. Toyo glossiness value of cooked milled rice considerably affected by storage period, and the pasting properties of milled rice were also influenced by storage. The final viscosity and breakdown value increased, but setback decreased during storage. In terms of storage protein, proportion of prolamin (14.3 kDa) and globulin (26.4 kDa) increased, whereas percentage of glutelin (34-39 kDa and 21-22 kD) decreased. Furthermore, the contents of total tocol and isomers decreased in stored brown rice.

• The Korean Journal of Food And Nutrition
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• v.26 no.3
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• pp.591-600
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• 2013

This study investigated the changes in the nutraceutical lipid components of brown rice oil after germination. Four different high-yielding cultivars (Dasan1, Segyejinmi, Hanareum1 and Hanareum2) of Korean brown rice were selected and brown rice oil was extracted from each cultivar before and after germination. Free fatty acid, squalene, policosanols, and isomers of phytosterol were analyzed using GC, and isomers of tocols (tocopherol and tocotrienol) and ${\gamma}$-oryzanol were quantified using HPLC from both brown rice oil (BRO) and germinated brown rice oil (GBRO). The contents of phytosterol isomers, campesterol, stigmasterol, and ${\beta}$-sitosterol were increased by 8.3%, 31.6%, 3.3% in GBRO, respectively. Furthermore, the squalene content showed the highest increase of up to 2.4 fold in GBRO compared to BRO. In addition, linoleic and linolenic acid composition increased whereas oleic and palmitic acid decreased in the GRBO. However, the contents of tocols (tocopherol and tocotrienol) in GBRO were lower than those in BRO, and there was no significant difference in policosanol and ${\gamma}$-oryzanol between GBRO and BRO. These results suggest that GBRO has the potential as a healthy and functional source due to its lipid profile on improved lipid metabolism.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.58 no.4
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• pp.367-375
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• 2013

The rice bran, a by-product of rice milling process, is well known for various functional components, such as tocopherol, tocotrienol, ${\gamma}$-oryzanol, carrying antioxidant activities. This study was conducted to investigate the antioxidant components and antioxidant activities in rice bran of different Korean rice cultivars. The 8 isomers of vitamin E, ${\gamma}$-oryzanol, flavonoids, and polyphenolics in rice bran from 16 Korean premium and high quality rice cultivars were quantified. DPPH and ABTS radical scavenging activities and reducing power of the ethanol extracts of rice bran were measured. 'Hopum' showed the highest total vitamin E content, $221.47{\mu}g/g$ among the cultivars, and 'Hanseol' showed the lowest content. The rice bran showed different compositions of ${\alpha}-$, ${\beta}-$, ${\gamma}-$, ${\delta}-$ tocopherol and tocotrienol among rice cultivars. The antioxidant contents were also different by cultivar; the ${\gamma}$-oryzanol contents ranged from 1.99 mg/g (Unkwang) to 4.30 mg/g (Chilbo), the polyphenol contents ranged from 427.22 mg gallic acid eq./100 g (Odaebyeo) to 775.80 mg gallic acid eq./100 g (Hopum). 'Hopum' also had the highest DPPH and ABTS free radical scavenging activities, 9.82% and 187.5 AEAC mg/100 g, respectively. In vitro, the rice bran extracts from 'Hopum' had significantly higher antioxidant activities than that of other cultivars.