• 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.

• 분석과학
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• 제11권6호
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• pp.478-484
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• 1998

상수리나무(Quercus acutissima, 3년생)의 잎, 줄기, 뿌리, 껍질, 및 열매에 각각 존재하고 있는 polyphenol 성분의 분포를 thin layer chromatography와 column chromatography를 이용하여 조사하였다. 총 25종류의 polyphenol 성분을 분리하였는데, 이들 중 잎에서 15개, 줄기에서 11개, 뿌리와 껍질에서 각각 7개를 분리하였으며, 열매에서는 4개의 성분을 분리하였다. 분리한 polyphenol 성분들 중에는 catechin 성분이 모든 부위에서 비교적 많이 분포하고 있었으며 일부 flavonoid 성분들도 확인되었다. 잎을 제외한 모든 부위에서 3종류의 polyphenol isomer의 존재를 확인했으며, 잎에서는 monomer와 oligomer성 polyphenol의 존재를 확인했으나 polymeric polyphenol이 확인되지 않았다. Quercus acutissima에서 polyphenol의 총함량은 껍질에서 상대적으로 가장 많았고, 다음으로는 뿌리, 잎, 열매의 순으로 많이 분포하였으며, 줄기에서 가장 적은 양이 확인되었다.

• 한국식품과학회지
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• 제35권5호
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• pp.959-967
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• 2003

한국산 배를 60% acetone으로 추출하여 Sephadex LH-20 gel column chromatography, MCI-CHP 20 gel column chromatography, Bondapack $C_{18}$ gel column chromatography을 이용하여 TLC와 HPLC로 순도를 검증한 후 4종의 polyphenol 화합물을 분리, 정제하였다. Compound A와 B는 Sepadex LH-20 gel column chromatography에서 증류수상에서 용출되었고 compound C는 40% methanol상에서 용출됨을 보아 compound B와 compound C는 흡착성이 강한 polyphenol 화합물이라 추정되었다. 분리, 정제한 4종의 compound를 NMR, FAM-mass 및 FT-IR를 이용하여 화학구조를 결정한 결과 compound A는 (+)-catechin, compound B는 (+)-gallocatechin, compound C는 (-)-epigallocatechin이고 compound D는 procyanidin B-3-3-o-gallate로 밝혀졌다.

• 약학회지
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• 제45권4호
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• pp.387-396
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• 2001

The effects of ascorbic acid, thiols such as cysteine, n-acetyl-ι-cyteine, glutathione, thiourea, 2-mercaptoethanol and dithiotreithol and organic acids such as magic acid, citric acid, glycolic acid, taurine and kojic acid on polyphenol oxidate (PPO) activity were studied in order to establish if it reacts with oxidized product and/or directly inhibits the enzyme. To investigate the mechanism, the quantification of t-butylcatechol and 4-methylcatechol (phenolic compounds) as substates, their oxidized product and sulphydryl colorless additional compounds were determined by high performance liquid chromatograph (HPLC) method. Chromatographic results indicate that ascorbic acid, organic acids and lower level of cysteine reduced oxidized product of substrates back to their respective positions uf ο-diphenols. On the other hand, other thiols and high level of cysteine reacted with oxidative product of ο-diphenols and then produced sulphydryl colorless compounds. Cysteine apperars to have two types of mechanism of actions in the formation of oxidative products of substrates depending on its concentration; ascorbic acid-type and other thiols-types. The effect of ascorbic acid with thiols on polyphenol oxidase was determined by same method. Chromatographic results indicate that ascorbic acid was more reactive with oxidized product of substrates than thiols.

• 농업과학연구
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• 제50권3호
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• pp.569-580
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• 2023

The aim of this study was to investigate the antioxidant effects of O. robusta stem extract (ORE) and to determine the total polyphenol and flavonoid contents. Free radical scavenging properties were evaluated using DPPH (2,2-diphenyl-1-picrylhydrazyl), ABTS (2,2'-azinobis (3-ethylbenzothiazoline-6-sulfonic acid)), and ·OH (hydroxyl radical) scavenging assays. Total polyphenol and flavonoid contents were measured using Folin-Ciocalteu reagent and aluminum chloride colorimetric methods, respectively. Active compounds of ORE were determined using high-performance liquid chromatography (HPLC). The results of the study showed that ORE exhibited DPPH, ABTS, and ·OH radical scavenging activities in a dose-dependent manner. Especially, 1,000 ㎍/mL of ORE showed the strongest radical scavenging properties against DPPH, ABTS, and ·OH. ORE contained total polyphenol content of 57.4 mg GAE/g and total flavonoid content of 5.4 mg QE/g, which may contribute to their antioxidant effects. As a result of HPLC, the contents of active compounds in ORE, dihydrokaempferol (0.65 ㎍/mL), and 3-O-methylquercetin (1.10 ㎍/mL) were confirmed. In conclusion, ORE may be useful as a functional material with antioxidant properties.

• Bulletin of the Korean Chemical Society
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• 제32권8호
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• pp.2593-2598
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• 2011

Polyphenols (PPs) are known as antioxidant compounds having benign biological activities. In this paper, a series of hybrid molecules between the free or acetyl protected polyphenol compounds were synthesized and their in vitro antioxidant activity (DPPH assay) and cholinesterase [acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE)] inhibition activities were evaluated. As expected, free phenolic hybrid compounds (6 and 8) showed better antioxidant activity than acetyl protected hybrid compounds (5 and 7) from DPPH assay. But the contrast result was obtained from BuChE inhibition assay. Acetyl protected hybrid compounds (5 and 7) showed better inhibition activity for BuChE than free phenolic hybrid compounds (6 and 8). Specifically, 10 (AcFA-AcFA) were shown as an effective inhibitor of BuChE ($IC_{50}=2.3{\pm}0.3{\mu}M$) and also had a great selectivity for BuChE over AChE (more than 170 fold). Inhibition kinetic studies with acetyl protected compounds (5, 7, 9, and 10) indicated that 5, 7 and 10 are a hyperbolic mixed-type inhibition and 10 is a competitive inhibition type. The binding affinity (Ki) value of 10 to BuChE is $2.32{\pm}0.15{\mu}M$.

• 약학회지
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• 제49권4호
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• pp.330-334
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• 2005

Antimutagenic activity of the enzymatic browning reaction products (EBRPs) was investigated by using the spore rec-assay with Bacillus subtilis strains H17 $(rec^+)\;and\;M45 (rec^-)$. The EBRPs tested were prepared from the reactions of five different kinds of polyphenols with polyphenol oxidase isolated from the leaves Perilla frutescens. In the spore rec-assay, most of the polyphenolic compounds tested showed positive, whereas only their tested compound showed negative respectively. In addition of polyphenol oxidase inhibitors such as cysteine, glutathione and ascorbic acid to the reaction mixtures consisted with the polyphenol oxidase and polyphenols, the mutagenic effects were increased in the spore recassay. These results show that the activity of polyphenol oxidase may play an important role in the reduction of mutagenicity of polyphenols.

• 생약학회지
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• 제48권3호
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• pp.208-212
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• 2017

In this study, analysis of active compounds that are believed to be highly relevant to antioxidant activity was carried out on the methanol extract and its solvent fractions of Corni fructus. The DPPH radical scavenging activity for the comparison of antioxidant activity was higher in order of aqueous fraction > methanol extract > ethyl acetate fraction > n-hexane fraction. It is similar to the order of total polyphenol contents in the samples. As a result of LC-MS analysis, phenolic acid compounds such as caffeic acid, gallic acid and chlorogenic acid and lognin, which is known as a representative active ingredient of Corni fructus, were identified as active compounds. And the antioxidative activity and the total polyphenol content of the extracts and solvent fractions were found to be related to the contents of the compounds. Particularly, it was confirmed that phenolic acid such as caffeic acid contributes to the antioxidative activity of the aqueous fraction of Corni fructus methanol extract.

• 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.

• 한국식품과학회지
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• 제34권3호
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• pp.493-497
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• 2002

한국산 인삼 5년근을 60% acetone으로 추출하여 Sepadex LH-20 gel column chromatography, MCI-CHP 20 gel column chromatography, Bondapak $C_{18}$, column chromatography을 이용하여 TLC와 HPLC로 순도를 검증한 후 3 종의 polyphenol 화합물을 분리하였다. Compound I과 II는 Sepadex LH-20 gel column chromatography에서 증류수상에서 용출되었고 compound Ⅲ는 40% methanol 상에서 용출됨을 보아 compound II와 compound III는 흡착성이 강한 polyphenol 화합물이라 추정되었다. 혈압강하에 관여하는 효소인 angiotensin converting enzyme(ACE)의 저해효과는 compound II가 157 ppm에서 31.86%로 3 가지 분획물 중 가장 우수하였으며 compound I과 III는 높은 활성을 보이지 않았다. 통풍예방에 관여하는 xanthine oxidase 저해효과는 compound I, II에서 666 ppm에서 100%저해효과를 나타내었으나 compound III는 저해효과가 낮았다. Melanin을 형성하는 tyrosinase 저해효과를 실함한 결과 compound III는 400 ppm에서 28.6%의 저해효과를 나타내었고 Compound I과 II의 저해효과는 낮았다.