• Preventive Nutrition and Food Science
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• 제9권2호
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• pp.150-155
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• 2004

The free radical scavenging activities and the protective effects of Rhus javanica extracts against oxidative damage induced by reactive oxygen species (ROS) were investigated. n-Hexane, ethyl acetate and water fractions were prepared from a methanol extract. DPPH radical, superoxide anion and hydroxyl radical scavenging activities were estimated. Intracellular ROS formation was quantified using fluorescent probes, 2', 7'-dichlorofluorescin diacetate (DCFH-DA) for hydroxyl radical and dihydroethidium (DHE) for superoxide anion. The oxidative DNA damage was investigated by the comet assay in HepG$_2$ cells exposed either to $H_2O$$_2$ or to menadione. The highest $IC_{50}$/ values for DPPH radical scavenging activity was found in the ethyl acetate fraction with a value of 5.38 $\mu\textrm{g}$/mL. Cells pretreated with $\geq$ 1 $\mu\textrm{g}$/mL of the ethyl acetate extract had significantly increased cell viability compared to control cells, which were not pretreated with the extract. Intracellular ROS formation and DNA damage in HepG$_2$ cells, which were pretreated with the various concentrations of Rhus javanica ethyl acetate extract and then incubated either with $H_2O$$_2$ or with menadione, reduced in a dose-dependent manner. These findings suggest that Rhus javanica might have biologically active components which have strong protective effects against ROS induced oxidative damages to the biomolecules, such as cell membranes and DNA.

• Natural Product Sciences
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• 제16권3호
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• pp.169-174
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• 2010

The seed of Phaseolus calcaratus Roxburgh (PHCR) is traditionally used for anti-pyretic and antiinflammatory effects. Although these effects are believed to be related to its antioxidant potential, little information is available for the mechanisms by which PHCR seed might scavenge free radicals or otherwise act as an antioxidant. In the present study, we purified some fractions from the ethanol extract of PHCR seed and evaluated each fraction's ability to scavenge free radicals generated by cell-free systems. We also identified active compound that is putatively responsible for free radical scavenging by analyzing NMR spectra. PHCR samples exhibited a concentration-dependent radical scavenging activity against hydroxyl radicals, superoxide anions, and DPPH radicals. Of the samples tested, a methanol-eluted sub-fraction from the PHCR extract, named $FF_4$, scavenged these radicals more effectively than the other fractions. We identified catechin-7-O-$\beta$-Dglucopyranoside as the active compound responsible for free radical scavenging potential of $FF_4$.

• ALGAE
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• 제28권4호
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• pp.371-378
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• 2013

Water and methanolic extracts of Ecklonia cava, a marine brown alga, were prepared by ultrasonic extraction (UE) and conventional extraction (CE) methods. The radical-scavenging activity and the inhibitory effects against hydrogen peroxide ($H_2O_2$)-induced DNA damage of the extracts were investigated. All extracts prepared by CE exhibited higher total polyphenolic content than that in the extracts prepared by UE. Extraction yield and total phenolic content increased as the UE time increased. The radical-scavenging activities increased as the UE time increased. All extracts prepared by CE exhibited higher 1,1-diphenyl-2-pricrylhydrazyl (DPPH) and hydroxyl radical-scavenging activities than did those prepared by UE. Extracts prepared by UE showed stronger scavenging activities on alkyl radical and $H_2O_2$ than those prepared by CE did. Methanolic extract with UE 12 h (100MEU-12h) and methanolic extract with CE 24 h (100MEC-24h) were selected and evaluated by comet assay for their inhibitory effect against $H_2O_2$-induced DNA damage. 100MEU-12h showed slightly greater protective effect against $H_2O_2$-induced DNA damage than 100MEC-24h. Thus, UE can be effectively used as a seaweed extraction technique, and there is potential for scale-up of the extraction process.

• 한국식품조리과학회지
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• 제20권2호
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• pp.219-226
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• 2004

This study was performed to investigate the change of chemical components and antioxidant activities in Hizikia fusiformis(Harvey) OKAMURA with blanching times. For chemical composition, the contents of minerals (K, Ca, Na, Mg, Fe, Cu, Mn and Zn), vitamins (vitamin C, ${\beta}$-carotene and ${\alpha}$-tocopherol) and total polyphenol were analyzed. The antioxidant activity was determined through free radicals (DPPH radical, superoxide anion radical, hydroxyl radical and hydrogen peroxide) scavenging activity and linoleic acid peroxidation inhibitory activity. As the blanching time increased, the contents of all minerals, vitamin C and total polyphenol decreased. However ${\beta}$-carotene and ${\beta}$-tocopherol were not affected by the blanching time. In addition antioxidant activities decreased with increasing blanching time.

• 한국식생활문화학회지
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• 제19권4호
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• pp.369-377
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• 2004

This study was performed to investigate the change of biologically functional compounds and antioxidant activities in Ecklonia cava with blanching times. As biologically functional compounds, the contents of minerals(K, Ca, Na, Mg, Fe, Cu, Mn and Zn), vitamins($vitamin\;C,\;{\beta}-carotene\;and\;{\alpha}-tocopherol$) and total polyphenol were analyzed. And antioxidant activity was determined through free radicals(DPPH radical, superoxide anion radical, hydroxyl radical and hydrogen peroxide) scavenging activity and linoleic acid peroxidation inhibitory activity. As the blanching time increased, the contents of minerals, vitamin C, ${\beta}-carotene$ and total polyphenol were decreased however ${\alpha}-tocopherol$ was not affected by blanching time, and antioxidant activities were decreased with blanching time.

• 한국식생활문화학회지
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• 제19권2호
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• pp.200-208
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• 2004

This study was performed to investigate the change of biologically functional compounds and antioxidant activities in Hizikia fusiformis with drying methods. As biologically functional compounds, the contents of minerals(K, Ca, Ma, Mg, Fe, Cu, Mn and Zn), vitamins(vitamin C, ${\beta}-carotene\;and\;{\alpha}-tocopherol$) and total polyphenol were analyzed. And antioxidant activity was determined through free radicals(DPPH radical, superoxide anion radical, hydroxyl radical and hydrogen peroxide) scavenging activity and linoleic acid peroxidation inhibitory activity. The contents of minerals were not affected by drying methods however vitamins and total polyphenol were lost more by sun-drying than other drying methods studies. Total polyphenol was preserved by freezing-drying than other drying methods studies, resulting in high antioxidant activities.

• 한국식품조리과학회지
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• 제31권1호
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• pp.26-32
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• 2015

The purpose of this research is to evaluate the quality characteristics and antioxidant activities of Makjang, Korean traditional fermented soybean paste, which has recently been disappearing, for its preservation. Six kinds of commercial Makjang from three different regions (Kang-won-do, Choong-chung-do, and Kyung-sang-do) were analysed for approximate composition, salinity, pH, total phenol contents, and DPPH and hydroxyl radical scavenging activities. Moisture content of samples was 48.30-58.93% while, crude protein was 9.42-13.67%. Crude fat was 2.45-6.50%, crude fiber was 2.08-6.45%, and ash was 6.59-14.64%. Salinity content ranged from 5.63-12.68%, and pH ranged from 4.36-5.67. Soluble solid content and reducing sugar content of samples ranged from 38.3-54.5 Brix and 22.38-31.61% respectively. The lightness, redness, and yellowness of the Hunter color system of samples were 16.58-28.19, 7.8-16.51, and 8.35-14.21, respectively. Total polyphenol contents were 0.20-0.45 mg/ml. Antioxidant activities determined by DPPH radical scavenging activity and hydroxyl radical scavenging activity ($IC_{50}$ value) ranged from 45.07 mg/ml to 95.93 mg/ml and 69.81 mg/ml to 309.40 mg/ml, respectively. From these results, it was suggested that the manufacturing process of Makjang is needed to standardize for quality control, and for mass production.

• 동아시아식생활학회지
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• 제22권4호
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• pp.521-526
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• 2012

본 연구는 염생 식물이라는 특성으로 인해 갯벌이 발달한 우리나라에서 쉽게 접할 수 있는 칠면초에 대한 분석과 항산화활성을 검토하고자 이루어졌다. 일반성분 분석 결과, 수분을 제외하고 탄수화물, 단백질, 회분의 함량이 10.75%, 8.3%, 7.6%로 많이 측정되었다. 무기질 중에서는 나트륨이 5.4%로 측정되어 회분의 대부분이 나트륨임을 알 수 있었다. 중금속함량 측정 결과, 납, 카드뮴, 비소, 수은은 각각 건물 기준 0.86 ppm, 0.04 ppm, 0.39 ppm, 0.01 ppm을 나타내어 식품으로서 기준치에 적합하였다. 70% 에탄올로 칠면초를 추출하여 항산화력을 알아본 결과, 총 페놀 함량과 총 플라보노이드 함량은 18.77 mg/g, 2.69 mg/g을 보여주었다. Hydroxyl radical 소거능, hydrogen peroxide 소거능, xanthine oxidase 소거능등을 측정하여 합성항산화제인 BHA와 비교한 결과, BHA의 30~50% 가량의 활성을 보여주었다.

• Bulletin of the Korean Chemical Society
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• 제29권6호
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• pp.1125-1130
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• 2008

A series of dihydroxylated chalcone derivatives with diverse substitution patterns on a phenyl ring B and the para-substituents on a phenyl ring A were prepared, and their radical scavenging activities were evaluated by simple DPPH test to determine quantitative structure-activity relationship in these series of compounds. The chalcone compounds with the ortho- (i.e. 2',3'- and 3',4'-) and para- (i.e. 2,5'-) substitution patterns show an excellent antioxidant activities (80-90% of control at the concentration of 50 $\mu$M) which are comparable to those of ascorbic acid and $\alpha$ -tocopherol as positive reference materials. On the contrary, the compounds with meta- (i.e. 2',4'-, 3',5'-) substitution pattern demonstrate very dramatic decrease in activities which are around 25% of the control even at the concentration of 200 $\mu$ M (IC50 > 200 $\mu$ M). These dramatic differences could be interpreted in terms of the ease formation of fairly stable semiquinone radicals from the ortho- and parasubstituted chalcone molecules through facilitating electron delocalization. Our results indicate that the substitution patterns of two hydroxyl groups on ring B are very important structural factors for their radical scavenging activity enhancement. Meanwhile, the substituents at para-position of the phenyl ring A of chalcones have no influence on the activity.

• 한국식품영양과학회지
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• 제42권3호
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• pp.355-362
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• 2013

본 연구에서는 효소처리 한 대두추출물의 항산화 및 미백 효과를 확인하기 위하여 DPPH 및 hydroxyl radical 포착활성을 측정하였고, 멜라닌 생성의 첫 단계인 tyrosinase 활성, mouse melanoma B16BL6 세포 생존율 및 TRP-1, TRP-2 발현 저해활성을 측정하였다. 또한 기존의 기계적 마쇄 가공한 대두추출물과 효소처리 가공한 대두추출물의 항산화 및 미백효과를 비교 조사하였다. 효소처리 한 대두추출물의 DPPH radical 소거능과 hydroxyl radical 소거능이 마쇄처리 한 추출물보다 높았으며, 특히 효소처리군이 마쇄군에 비하여 20% 이상 높은 항산화력을 나타내었다. 또한 마쇄군에 비하여 효소처리군이 tyrosinase와 TRP-1, TRP-2의 더 높은 활성 억제능을 보였다. 이는 대두가 B16BL6 melanoma 세포의 tyrosinase 단백질의 활성을 저해시킴으로써 멜라닌 생성을 억제하는데 효과적임을 의미하는 동시에 효소처리에 의하여 대두의 영양소의 손실이 더 적었음을 나타낸다. 결론적으로 효소처리에 의한 대두 추출물은 항산화 활성과 미백 효과가 우수하여 기능성 화장품의 천연 소재로서 활용 가능성이 매우 높은 것으로 사료된다.