• Journal of the Korean Society of Food Science and Nutrition
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• v.25 no.5
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• pp.721-726
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• 1996

Fatty acid composition and phenolic acid content of rice with different milling fractions were analyzed to provide basic data for nutrition, processing and storage of rice. Major fatty acids of rice were palmitic, oleic and linoleic acids and their respective contents were 20.0%, 33.3% and 43.0% of embryo, 17.3%, 45.1% and 34.5% of rice bran and 23.4%, 26.2% and 46.1% of milled rice. Outer fraction had a high content of oleic acid but a low content of linoleic acid in rice bran. As milling yields increased in milled rice, oleic acid content increased, but palmitic acid, linoleic acid, stearic acid and linolenic acid contents decreased. Contents of free, esterified and insoluble bound phenolic acid extracts from bran were 321.0mg%, 299.7mg% and 212.4mg%, respectively. Milled rice contained 118.0mg% of free phenolic acids, 56.0mg% of insoluble bound phenolic acids and no esterified phenolic acids. Rice bran contained 86.2% of ferulic acid as a principal phenolic acid. It also contained 35.7~36.6% of sinapic and syringic acids, 16.7% of p-coumaric acid and 0.13% of vanillic acid as minor component. Contents of total phenolic acid, expressed in terms of tannic acid, among rice with different milling fractions was highest in embryo. It was higher in outer fraction in bran, but rarely detected as fractionation of the component with milling in milled rice.

• Korean Journal of Agricultural Science
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• v.46 no.1
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• pp.85-92
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• 2019

This study was intended to provide basic data for a health functional food study by exploring antioxidant activity of reflux extract according to the concentration of ethanol and the extract of ultrasonic waves extracted and reflux extracted under the same solvent conditions. In the same solvent condition, the reflux extract ($75.10{\pm}1.99mg$) showed a higher total phenol content than the ultrasonic wave extract ($51.74{\pm}2.28mg$). Flavonoids also had a higher reflux extract ($25.05{\pm}1.53mg$) than did ultrasonic extracts ($16.23{\pm}1.95mg$). Reflux extract according to ethanol concentration was found to have a higher phenol content than the 70% ethanol extract ($40.60{\pm}1.49mg$) in 60% ethanol extract. Flavonoid content was also similar to phenol content in reflux extract as determined by ethanol concentration from 60% ethanol ($25.05{\pm}1.53mg$) to 70% ethanol extract ($6.60{\pm}0.46mg$). In addition, the antioxidant activity (DPPH, TEAC, FRAP, ORAC) of the reflux extract in the same solvent conditions tended to be higher than that of ultrasonic extracts. Also, 60% ethanol extract had better antioxidant activity than 70% ethanol extract. However, an analysis of phenolic acid content through HPLC showed that the ultrasonic extract had a higher content in the same solvent condition than did the reflux extract. Not only the presence of phenolic acid, but also those of other compounds are believed to be attributed to the activity of antioxidants. Therefore, further studies are needed to clarify this phenomenon.

• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.183-183
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• 2022

This study was aimed to investigate the content of avenanthramides(AVNs) and other phenolic compounds in the grains of a naked oat cultivar, Daeyang, which were seeded in the fall and spring, and examine the effects of alcohol extracts from the grains on natural killer(NK) cell activity in vitro. The content of AVN-A, AVN-B, and AVN-C in the spring-seeded oat grains was 2.2 folds higher than the fall-seeded oat grains on average. Among these AVNs, the content of AVN-C was 1.9-folds higher in the spring-seeded oat grains(66.1㎍/g), comparing to the content in the fall-seeded oat grains(34.8㎍/g). The content of other phenolic compounds, such as phenolic acids and flavonoids in the spring-seeded oat grains was 1.1~4.7-folds higher than the fall-seeded oat grains. In particular, sinapinic acid was the most abundant phenolic acid in the spring-seeded oat grains(50.0㎍/g) and its content was 2.4-folds higher than its content in the fall-seed oat grains. Furthermore, NK cell activity in vitro treated with the spring-seeded oat grain extracts was 158%, and it was 18%p higher than NK cell activity treated with the extracts from the fall-seeded oat grain extracts. Our finding suggest that the bioactive properties of naked oat grains would be enhanced by spring seeding.

• Journal of Applied Biological Chemistry
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• v.65 no.2
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• pp.89-92
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• 2022

In this study, the effects of soil conditions on antioxidant activities of the aerial and underground parts of rosemary were assessed to determine the most effective soil conditions for cultivation. The antioxidant activity was the highest (51.58±2.93 ㎍/mL) when cultivated in the mixture of gardening soil and vermiculite using DPPH assay. The antioxidant activity of underground parts the highest (127.48±12.38 ㎍/mL) when cultivated in the mixture of soil, vermiculite, and perlite. ABTS assay showed that the antioxidant activity of aerial parts was 230.34±57.93 ㎍·mL^-1 when cultivated in the mixture of gardening soil and vermiculite and that of underground parts was 320.98±16.04 ㎍·mL^-1 when cultivated in the mixture of gardening soil, vermiculite, and perlite. The total phenolic content of aerial parts was the highest (155.25±2.96 mg GAE/g) when cultivated in the mixture of gardening soil. The total flavonoid content of aerial parts was the highest (67.32±5.27 mg QE/g) when cultivated in the mixture of gardening soil. Therefore, the mixture of gardening soil, vermiculite, and perlite is superior to gardening soil alone for cultivation of rosemary to increase its antioxidant activity as well as total phenolic and flavonoid content.

• Journal of Ginseng Research
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• v.40 no.1
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• pp.68-75
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• 2016

Background: The study of phenolic compounds profiles and antioxidative activity in ginseng fruit, leaves, and roots with respect to cultivation years, and has been little reported to date. Hence, this study examined the phenolic compounds profiles and 2, 2-diphenyl-1-picrylhydrazyl (DPPH) free-radical-scavenging activities in the fruit, leaves, and roots of Korean ginseng (Panax ginseng Meyer) as a function of cultivation year. Methods: Profiling of 23 phenolic compounds in ginseng fruit, leaves, and roots was investigated using ultra-high performance liquid chromatography with the external calibration method. Antioxidative activity of ginseng fruit, leaves, and roots were evaluated using the method of DPPH free-radical-scavenging activity. Results: The total phenol content in ginseng fruit and leaves was higher than in ginseng roots (p < 0.05), and the phenol content in the ginseng samples was significantly correlated to the DPPH free-radical-scavenging activity ($r=0.928^{****}$). In particular, p-coumaric acid ($r=0.847^{****}$) and ferulic acid ($r=0.742^{****}$) greatly affected the DPPH activity. Among the 23 phenolic compounds studied, phenolic acids were more abundant in ginseng fruit, leaves, and roots than the flavonoids and other compounds (p < 0.05). In particular, chlorogenic acid, gentisic acid, p- and m-coumaric acid, and rutin were the major phenolic compounds in 3e6-yr-old ginseng fruit, leaves, and roots. Conclusion: This study provides basic information about the antioxidative activity and phenolic compounds profiles in fruit, leaves, and roots of Korean ginseng with cultivation years. This information is potentially useful to ginseng growers and industries involved in the production of high-quality and nutritional ginseng products.

• Tribology and Lubricants
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• v.16 no.4
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• pp.266-273
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• 2000

The friction characteristics of phenolic resin and model friction materials were investigated with the content of hexamethylenetetamine (HEXA). At 10 wt.% of HEXA, the phenolic resin and model friction materials showed the most stable friction coeffcient in constant temperature test at various test conditions because of its good thermal stability and proper curing reaction. It was found from constant interval test in mild condition that the friction coeffcients of friction materials cured with 10 wt.% of HEXA was the highest and stable values in the whole range of braking operations. However, at the severe condition in constant interval test, the friction coefficient of friction materials cured with 10 wt.% to of HEXA was lowered and as the number of braking operation increased, the values became stable. In order to obtain the thormal stable friction materials, the content of HEXA from 5 to 10 wt.% could be recommended.

• Advances in Traditional Medicine
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• v.7 no.2
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• pp.162-170
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• 2007

Woodfordia fruticosa Kurz. (Lythraceae), commonly known as Dhayero, is used in the treatment of various ailments in Nepal. In this study, the antioxidant capacity of crude extract and different polarity fractions of Woodfordia fruticosa flowers were assayed for their scavenging abilities against 1,1-diphenyl-2-picrylhydrazyl (DPPH) and nitric oxide radicals, competitive ${\beta}$-carotene bleaching, reducing power, metal chelating ability and total phenolic content. Crude extract and polar fractions showed stronger antioxidant capacity and contained very high level of total phenolics. They exhibited strong DPPH radical scavenging, nitric oxide scavenging and reducing power, medium ${\beta}$-carotene bleaching and poor metal chelating capacity. Positive correlation obtained between total phenolic content and antioxidant capacity assays, indicated the contribution of phenolics toards antioxidant capacity.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 2001.06a
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• pp.114-114
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• 2001

The thermal and friction characteristics of phenolic resin and model friction materials were investigated with the content of acrylonitrilebutadienerubber(NBR). The thermal characteristics of material was performed by dynamic mechanical thermal analysis and differential scanning calorimetry. The friction and wear characteristics of the material were determined by using friction material testing machine. The results show that with the more content of rubber, the loss modulus of friction material was increased. The friction coefficient and the specific wear rate with various NBR contents were reported.

• Biomedical Science Letters
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• v.26 no.4
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• pp.319-326
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• 2020

This study was conducted to develop a new functional material by optimizing the conditions for high concentrations of chlorogenic acid and eleutheroside E in Acanthopanax koreanum stem. The total phenolic compound content was the highest in the 20 hours sonication Acanthopanax koreanum stem extract (UAK-20). In addition, eleutheroside E, a typical functional ingredient of Cortex Acanthopanacis, in the 20 hours treated Acanthopanax koreanum stem extract showed the highest content at 1.646%. However, another functional ingredient, chlorogenic acid, showed the highest content of 2.625% in 1 hour treated Acanthopanax koreanum stem extract. Therefore, it is considered that the optimal conditions for high concentrations of total phenolic compound and eleutheroside E are 20 hours sonication Acanthopanax koreanum stem extract.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.2
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• pp.153-160
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• 2013

The peel from seven types of citrus was extracted with 80% methanol, and their phenolic compound content, oxygen radical absorbance capacity (ORAC), inhibitory activities of nitric oxide (NO), and reactive oxygen species (ROS) production induced by LPS and t-BHP in LPS-activated RAW 264.7 cells were measured. Total phenolic content was high in Yungkyool, Cheonhyehyang, and Jinkyool (30.6, 30.2, and 28.2 mg GAE/g, respectively), while total flavonoid content was high in Yungkyool and Jinkyool (30.3 and 25.5 mg RE/g, respectively). ORAC was the highest at 1,076 mM TE/g in Yungkyool, followed by Cheonhyehyang (1,012), Jinkyool (984), and Hallabong (914). High inhibitory activity against NO production was shown in Cheonhyehyang, Yungkyool, and Jinkyool with $IC_{50}$ values of 215.3, 259.2, and 328.9 ${\mu}g/mL$, respectively. LPS-induced ROS production was inhibited by 16.4% and 12.8% in Hallabong and Jinkyool, while t-BHP-induced ROS production was inhibited by 28.7%, 26.1%, and 26.6% in Jinkyool, Hallabong, and Cheonhyehyang, respectively. Correlation coefficients between total phenolic, total flavonoid content, and ORAC were 0.884 and 0.855. Inhibitory activity against NO production showed higher correlation with total phenolic content than total flavonoid content. It was concluded that citrus peels had potent antioxidant activities and could be used as natural antioxidants in the food and pharmaceutical industries.