• Journal of Forest and Environmental Science
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• 제21권1호
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• pp.16-23
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• 2005

강원대학교 구내림에서 오동나무 잎을 채취하여 아세톤-물(7:3, v/v)로 추출하고 n-hexane, methylene chloride, ethylacetate 및 $H_2O$ 등 네 개의 분획으로 분리한 후 에틸아세테트용성 분획물을 Sephadex LH-20으로 칼럼 크로마토그래피를 수행하였으며 용리용매는 메탄올 수용액과 에탄올-헥산 혼합액을 사용하였다. 그 결과 flavonoid류 화합물인 (+)-catechin, (-)-epicatechin, apigenin, luteolin, taxifolin과 phenolic acid류 화합물인 $\rho$-hydroxybenzoic acid, vanillic acid 및 $\rho$-coumaric acid를 단리 하였다. 단리된 화합물은 NMR 및 MS 스펙트럼을 이용하여 구조를 결정하였다.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2017년도 제48회 춘계학술대회논문집
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• pp.521-528
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• 2017

본 논문에서는 고체 로켓 추진기관에서 내열재 및 단열재로 사용되는 실리카/페놀릭 복합재료의 열 반응을 고려한 열전도 수치해석을 수행하였다. 고체 로켓 추진기관의 연소 중 실리카/페놀릭의 삭마와 열분해 과정을 고려한 열전도 해석을 위해 1차원 유한차분법을 이용하여 계산을 수행하였다. 노즐벽에서의 경계조건은 대류열전달계수를 고려하였으며, 이는 적분방정식을 이용하여 계산하였다. 삭마두께 및 숯깊이 해석결과는 목삽입재 평가 모터인 TPEM-10을 이용한 시험결과와 비교분석하였으며, 잘 일치하는 것을 확인할 수 있었다.

• 한국식생활문화학회지
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• 제30권6호
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• pp.790-796
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• 2015

The objective of this study was to investigate the physicochemical properties and antioxidant activities of seven (A, B, C, D, E, F, G) commercial ketchups marketed in Korea. The 70% ethanol extracts were prepared and evaluated for total phenolic content, DPPH and ABTS radical scavenging activities, and metal chelating effect. pH ranged from 3.64 to 3.94, and soluble solid and reducing sugar contents of samples were 2.21~3.51oBrix and 4.78~13.45%, respectively. Salinity of samples was in the range of 1.79 to 3.21%, and sample G showed the lowest salinity. The lightness, redness, and yellowness of the Hunter color system of samples were 15.42~19.94, 18.55~23.98, and 20.87~24.34, respectively. The phenolic contents ranged from 1.37 to 2.60 mg GAE (gallic acid equivalents)/g, with samples F and G exhibiting the highest contents. Antioxidant activity determined based on DPPH and ABTS radical scavenging activities, and metal chelating effects were 45.10~90.87, 55.35~92.53, and 71.10~92.20%, respectively, at a concentration of 200 mg/mL. Samples A and G showed higher antioxidant activity than other samples. There were positive correlations between phenolic contents and antioxidant activity, suggesting that phenolic compounds are the major contributors to antioxidant activity.

• 펄프종이기술
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• 제37권5호통권113호
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• pp.50-55
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• 2005

In previous report, we investigated the impact of hexeneuronic acid and some residual extractiveson lignin determination. These non-lignin components severely interfered lignin content determination which also affect on the oxygen delignification comparison between aspen and pine unbleached kraft pulps. Very different pattern was observed whether based on uncorrected conventional kappa number or based on corrected kappa number in oxygen delignification comparison. Lower kappa number aspen pulps showed poor response to oxygen delignification when kappa number was used as lignin determination method but better response with using the acid lignin method. Phenolic hydroxyl group in kraft pulps were also compared based on uncorrected or corrected kappa numberfor lignin content. Based on uncorrected kappa number, lower kappa number oxygen-delignified pulps had lower phenolic hydroxyl group. However, lower kappa number oxygen-delignified pulps showed much higher phenolic hydroxyl group based on the corrected lignin content. For accurate comparison for residual lignin properties from different pulps, lignin determination should be corrected from non-lignin components contribution to lignin.

• 한국추진공학회지
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• 제22권4호
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• pp.76-84
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• 2018

본 논문에서는 고체 로켓 추진기관에서 내열재 및 단열재로 사용되는 실리카/페놀릭 복합재료의 열반응을 고려한 열전도 수치해석을 수행하였다. 고체 로켓 추진기관의 연소 중 실리카/페놀릭의 삭마와 열분해 과정을 고려한 열전도 해석을 위해 1차원 유한차분법을 이용하여 계산을 수행하였다. 노즐벽에서의 경계조건은 대류열전달계수를 고려하였으며, 이는 적분방정식을 이용하여 계산하였다. 삭마두께 및 숯깊이 해석결과는 목삽입재 평가 모터인 TPEM-10을 이용한 시험결과와 비교분석하였으며, 잘 일치하는 것을 확인할 수 있었다.

• International Journal of Advanced Culture Technology
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• 제7권3호
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• pp.120-125
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• 2019

In this paper, we have isolated six phenolic compounds, such as (+)-catechin (1), taxifolin (2), taxifolin-3-O-${\beta}$-D-(+)-xylose (3), quercetin (4), quercetin-3-O-${\alpha}$-L(+)-rhamnose (quercitrin) (5), apigenin-8-C-rhamnosyl-(1'''${\rightarrow}$2'')-glucoside (2''-O-rhamnosylvitexin) (6) from the EtOAc(Ethyl Acetate) and $H_2O$ soluble fractions of Japanese anise(Illicium anisatum L) leaves and twigs. Also, we have evaluated antioxidative and antiviral activity for each isolated compound. The antioxidative test was DPPH (1,1-diphenyl-2-picrylhydrazyl) radical scavenging activity. According to the experimental results, all of the isolated compounds indicated the increased radical scavenging activities as the concentration increases and most of the isolated compounds indicated generally good antioxidative values compare to the controls, ascorbic acid and ${\alpha}$-tocopherol. In the antiviral activities, all of the isolated compounds had no potentials in rhinovirus 1B (HRV 1B). But in enterovirus 71 (EV 71) and Influenza virus A/PR/8 (Influenza PR8), only quercetin (4) indicated the good antiviral activity compare to the control. Based on the above results, we found that the phenolic compounds of Japanese anise may be applied for one of the natural biomass sources that can be used as an antioxidant and an antiviral substance.

• Natural Product Sciences
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• 제25권1호
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• pp.44-48
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• 2019

Nelumbo nucifera Gaertn. (Nymphaeaceae) is commonly called lotus and its leaves are widely been used as functional ingredients due to its antioxidant activity. For maximum efficacy, optimized extraction condition was established using response surface methodology. The high F-values, low p-values and insignificant p-value for lack-of-fit supported the fitness of the model and yielded the second-order polynomial regression for the antioxidant activity. The optimized extract was obtained by the extraction of 1 g of lotus leaves with 40 mL of 50% MeOH at $10.0^{\circ}C$, which exerted 70.1% antioxidant activity. Close correlation between phenolic content and antioxidant activity suggested phenolic compounds as active constituents of lotus leaves. In addition, comparison of different parts of lotus demonstrated the most potent antioxidant activity of flowers, followed by leaves and roots. Taken together, these results provide useful information about lotus leaves for the development as antioxidant ingredients. In addition, flowers and roots as well as leaves are suggested as good sources for antioxidant activity.

• Journal of Applied Biological Chemistry
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• 제63권4호
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• pp.297-303
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• 2020

Berries are rich sources of phenolic compounds, which are known to have health-promoting effects. In this study, phenolic compounds of seven popularly consumed berries were analyzed by HPLC-ESI-MS/MS. In addition, 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical and nitrite scavenging activities were investigated for comparison of the biological activity of the berry extracts. Chlorogenic acid was the major phenolic acid, which had the highest content in aronia, followed by blueberry. The rutin and isoquercetin contents were the highest in mulberry, followed by aronia, black raspberry, and blueberry. The anthocyanin content was the highest in black raspberry. Aronia showed the highest DPPH free radical and nitrite scavenging activities with the highest contents of total phenolics and proanthocyanidins.

• 한국식생활문화학회지
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• 제38권6호
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• pp.456-464
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• 2023

The purpose of this study was to investigate nutritional and functional ingredients and antioxidant activity after fermenting rice bran using Lactobacillus brevis for 24, 36, and 48 hours. The results of the analysis of the nutritional ingredients revealed that there was no significant difference in the carbohydrate, crude protein, crude fat and ash content regardless of the fermentation process and fermentation time. The amount of dietary fiber was significantly different between the unfermented and fermented rice bran and was observed to be the highest after a 48-hour fermentation. The γ-oryzanol, gamma-aminobutyric acid (GABA) and total phenolic contents were significantly higher in the fermented rice bran compared to the unfermented rice bran (p<0.05) and the GABA and total phenolic contents increased significantly as the fermentation time increased (p<0.05). The 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS), superoxide and hydroxyl radical scavenging activities used to measure antioxidant effects significantly increased as the fermentation time increased (p<0.05). From these results, it was confirmed that the antioxidant effect and functional components, namely γ-oryzanol, GABA, and the total phenolic content of rice bran improved with fermentation. Based on these results, fermented rice bran could be presented as a functional material for use in high value-added industries.

• 한국산림과학회지
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• 제102권4호
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• pp.566-570
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• 2013

정금나무의 기능성 품종을 육성하기 위하여 정금나무 선발 5개체의 열매에 대한 항산화 활성을 측정하였으며, 항산화 성분인 총 페놀 함량을 측정하였다. 총 페놀 함량은 gallic acid를 기준물질로 하여 분석한 결과 15.8~19.9 mg/g 범위로 전체 평균 17.9 mg/g을 나타냈으며, DPPH free radical 소거활성은 400 ppm의 농도에서 69.1~91.4% 범위로 전체평균 84.2%를 나타내었다. 환원력은 0.56~0.96 범위로 전체 평균 0.79를 나타내었다. 상관분석 결과 DPPH free radical 소거활성과 환원력에서 상관계수가 0.969로 매우 높은 정의 상관관계를 나타내었다.