• Journal of Plant Biology
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• 제16권1_2호
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• pp.6-11
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• 1973

The utilization of acetate by Dunaliella tertiolecta was examined, and the detections and assays of the enzymes of the tricarboxylic acid cycle and the glyoxylate pathway were described. Acetate could not be utilized as a sole carbon source for the growth. The carboxyl carbon of acetate was incorporated more rapidly into CO2 than the methyl carbon. It was identified that malate, succinate, citrate and etc., were accumulated whne [U-14C] acetate was supplied to the cell free homogenate. The following enzyme activities were measured; acetothiokinase, isocitrate dehydrogenase, fumarase, malate dehydrogenase and aconitase. Though isocitratase, malate synthetase, succinate dehydrogenase and oxoglutarate dehydrogenase could not be detected, 14C from succinate was easily contributed to CO2 and cell component. The evidence suggested that the glyoxylate pathway was not operative and showed that the TCA cycle was the all important pathway in the oxidation of acetate to CO2 in Dunaliella.

• 한국응용과학기술학회지
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• 제26권1호
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• pp.87-92
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• 2009

In this study, we evaluated anti-oxidation and whitening effects of Ligularia stenocephala extract for use as the cosmeceuticals. L. stenocephala was extracted by three different solvents which was n-Hexane, ethyl acetate, $H_{2}O$. The free radical (1,l-diphenyl-2-picrylhydrazyl, DPPH) scavenging activity of extract of L. stenocephala was in the order: ethyl acetate fraction of leaf ($IC_{50}$ value of 10.512ug/mL) > ethyl acetate fraction of stem ($IC_{50}$ value of 31.877ug/mL) > $H_{2}O$ fraction of leaf ($IC_{50}$ value of 129.194ug/mL). Reactive oxygen species (ROS) scavenging activity of extract of L. stenocephala was in the order: ethyl acetate fraction of leaf ($IC_{50}$ value of 0.230mg/mL) > ethyl acetate fraction of stem ($IC_{50}$ value of 0.528mg/mL) > $H_{2}O$ fraction of leaf ($IC_{50}$ value of 0.799mg/mL). Tyrosinase inhibition activity of L. stenocephala extracts was reduced 29.477% on ethyl acetate fraction of leaf, 13.583% on ethyl acetate fraction of stems. Therefore, L. stenocephala extracts may be useful as a new antioxidant and whitening agent to inhibit melanogenesis.

• Applied Biological Chemistry
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• 제50권4호
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• pp.327-333
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• 2007

본 연구에서는 차조기의 30, 50, 70, 95% 에탄올 및 물추출물과 분획물의 전자 공여능, 지질산화 억제능, SOD 유사활성 및 xanthin oxidase 저해 활성을 측정하였다. 추출물의 전자 공여능은 $18{\sim}30%$ 정도로 낮았으나, 분획물에서는 95%과 70% 에탄올 추출물의 chloroform 분획이 50% 수준의 활성을 보였고, ethyl acetate 분획에서는 모든 추출용매에서 75% 이상의 활성을 보였다. 특히, 70% 에탄올 추출물의 ethyl acetate 분획물이 93.4%로 가장 높은 활성을 보였으며 $RC_{50}$에 요구되는 농도는 200.5 ppm이었다. 저장 온도 $40^{\circ}C$에서 linoleic acid의 자동산화를 가장 효과적으로 억제하는 것으로 나타난 추출물은 70% 에탄올 이었다. 분획물의 경우, 95% 에탄추출물은 hexane과 ethyl acetate 가용성분이 그 외 에탄올 추출과 물추출은 chloroform과 ethyl acetate 가용성분이 가장 높은 억제효과를 나타내었다. SOD 유사활성은 에탄올 추출물이 $28{\sim}32%$, 물추출물이 30.3%이었으며, 70% 에탄올 추출물이 32.4%로 가장 높았다. 분획물에서는 70% 에탄올 추출물의 ethyl acetate 가용분이 38.8%로 활성이 가장 높았으며 $IC_{50}$에 요구되는 농도는 1549.0ppm이었다. Xanthine oxidase 저해 활성은 에탄올추출물이 $36{\sim}41.2%$이었으며, 물추출물이 46.9%로 추출물중 가장 높았다. 분획물에서는 물추출의 ethyl acetate 가용분이 1,000 ppm 농도에서 52%의 활성을 보여 가장 높았다.

• Environmental Engineering Research
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• 제13권4호
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• pp.210-215
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• 2008

The present study investigates the effect of oxidation-reduction potential (ORP) and organic compounds on specific anaerobic ammonium oxidation activity (SAA) using batch experiments. The batch tests were based on the measurement of nitrogen gas production. The relationship between ORP and dissolved oxygen (DO) concentration was found to be ORP (mV) = 160.38 + 68 log [$O_2$], where [$O_2$] is the DO concentration in mg/L. The linear relationship obtained between ORP and SAA ($R^2$ = 0.99) clearly demonstrated that ORP can be employed as an operational parameter in the Anammox process. At ORP value of -110 mV, the SAA was $0.272{\pm}0.03\;g\;N_2-N\;(g\;VSS)^{-1}\;d^{-1}$. The investigation also revealed inhibitory effect of glucose on the SAA while acetate concentration up to 640 mg COD/L (corresponding to 10 mM) had stimulating effect on the SAA. However, acetate concentration beyond 640 mg COD/L had inhibitory effect on the Anammox activity. The results indicated that nitrogen rich wastewaters containing low level organic matter could be better treated by Anammox microorganisms in real-world conditions after some acidification process.

• Journal of Applied Biological Chemistry
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• 제55권1호
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• pp.35-39
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• 2012

선학초 열수 추출물과 에탄올 추출물의 분획물을 항산화 및 주름개선의 소재로 이용하기 위하여 생리활성을 검증하였다. 항산화효과를 확인하기 위하여 전자공여능을 측정한 결과 선학초 열수추출물(AW)과 에탄올추출물(AE) 모두 ethyl acetate층 1,000 ppm에서 각각 96.2, 92.3%의 효과를 나타내었고, SOD 유사활성능을 측정한 결과 AW의 ethyl acetate층에서 61.8%의 활성을 AE의 $n$-butyl alcohol 층에서 58.0%의 높은 활성을 각각 나타내었다. 또한 xanthine oxidase저해활성을 측정한 결과 AW와 AE에서 모두 ethyl acetate층 1,000 ppm일 때, 각각 84.9, 92.5%의 가장 높은 저해율을 나타내었다. 주름개선 효능 확인을 위해 elastase 저해활성을 측정한 결과 이 또한 AW와 AE 모두에서 ethyl acetate층이 각각 55.2, 70.1%의 효능을 나타내었으며, collagenase 저해활성을 측정한 결과 AW의 ethyl acetate층이 90.6%로 가장 높은 저해율을, AE는 88.6%로 $n$-butyl alcohol 층이 가장 높은 저해율을 나타내었다. 이상의 결과로 미루어 보아 선학초의 열수 추출물과 에탄올 추출물의 분획물이 in vitro상에서 항산화 및 주름개선의 활성이 있음을 확인할 수 있었다.

• Food Science and Biotechnology
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• 제16권3호
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• pp.409-414
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• 2007

Antimicrobial and antioxidative effects of 14 different herbal flower extracts on skin microorganisms and oxidation were tested in this research. Herbal flower extracts were prepared with 70% ethanol. Among the herbal flower extracts, roselle (Hibiscus sabdariffa L.) flower extract showed the highest antimicrobial activity against Staphylococcus epidermidis as determined by a paper disc method. The seventy % ethanol extract of roselle flower was fractionated by sequential hexane, chloroform, ethyl acetate, n-butanol, and water fractionation. The growth of S. epidermidis, Streptomyces collinus, Streptomyces coeruleoprunus, Salmonella enteritidis, Vibrio parahaemolyticus, and Malassezia pachydermatis was most efficiently inhibited by ethyl acetate fraction of roselle flower extract as determined by a paper disc method and growth inhibition curves. In addition, the ethyl acetate fraction, water fraction and butanol fraction showed free radical scavenging and DNA cleavage inhibition activities. These results demonstrate that roselle flowers hold antimicrobial and antioxidative activities against skin microorganisms and oxidants.

• 대한한의학회지
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• 제25권2호
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• pp.1-8
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• 2004

Objectives : This study was performed to investigate the effects of Smilacis GlabraeRhizoma on antioxidation and antimicrobial activity. Methods : In this study, we investigated the effects of peroxide radicals on hydrogen donating activity and linoleic acid, and the MDA contents on the hepatic lipids of rats, via methanol extractions and subfractions of Smilacis Glabrae Rhizoma. Results : 1. Hydrogen donating activity was very great for the radical scavenging effects, depending on the additional concentration at the fraction level of chloroform and ethyl acetate. 2. The peroxide radicals in linoleic acid were lower depending on the additional concentration, at the fraction level of ethyl acetate, than the controls. We concluded that both had significant anti-oxidation effects. 3. MDA contents of the hepatic lipid had also inhibition effects on lipid radicals, in proportion to the concentration of n-hexane, chloroform, and ethyl acetate fraction level. 4. After extracting Smilads Glabrae Rhizoma with 80% methanol, we experimented with the extracts the antibiosis each concentration, for 5 bacilli, Bacilus subtilis, staphylococcus aureus, Escherichia coli, Salmonela typhimurium, and Alcaligenes faecalis. While the effects showed differentiations by concentration, they had usually the significant inhibition effect for the multiplication at 37.5~75ug/ml. To identify the effective constituents, we identified the antibiosis of the fractions assaying cyclically hexane, chloroform, ethyl acetate, and butanol. The result showed that antimicrobial activation of both Gram-positive and Gram-negative bacillus except for E. coli was measured highest at the fraction level of BuOH and water. Conclusions : This result suggest that the extractions of Smilacis Glabrae Rhizoma, at ethyl acetate fraction, had significant anti-oxidation effects and at BuOH and water fraction had relatively strong antimicrobial activity against Bacilus subtilis, staphylococcus aureus, Salmonela typhimurium, and Alcaligenes faecalis.

• Food Science and Biotechnology
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• 제16권5호
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• pp.854-857
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• 2007

In this study, the crude methanol extract of mulberry leaves was fractionated with chloroform, ethyl acetate, n-butanol, and water, successively. The antioxidant activities of the fractions were examined with the 2-deoxyribose oxidation and linoleic acid peroxidation methods. The ethyl acetate fraction showed the strongest antioxidant activity. From it we isolated chlorogenic acid, caffeic acid, quercetin $3-O-{\beta}-D-glucopyranoside$, and kaempferol $3-O-{\beta}-D-glucopyranoside$ with preparatory octadecyl silane-high performance liquid chromatography (ODS-HPLC), and identified the compounds by nuclear magnetic resonance (NMR) and fast atom bombardment mass (FAB-MS) analyses. Overall, quercetin $3-O-{\beta}-D-glucopyranoside$ showed the strongest antioxidant activity by both the 2-deoxyribose oxidation and rat liver microsome peroxidation methods.

• 한국식품과학회지
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• 제30권5호
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• pp.1214-1221
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• 1998

지질 산화에 의해 생성하는 MDA (malondialdehyde)를 thiobarbituric acid와 반응시켜 측정한 MDA 값은 곰취 추출물의 농도가 증가함에 따라 감소하므로서 추출물들에 의해 산화가 억제됨을 알 수 있었다. 메탄올 추출물의 경우 $15\;{\mu}g/mL$농도로 첨가시 71.7% (13.36 nmol/㎎)의 산화억제율을 나타내었으며 분획물의 경우 ethyl acetate 분획물이 동일농도에서 97% (1.35 nmol/mg)의 억제율을 나타내었다. 산화시간에 따른 MDA 값의 변화는 $25\;{\mu}g/mL$의 농도를 첨가시 에탄올, 메탄올 및 물 추출물의 경우 4시간까지 산화를 억제하였으며 분획물의 경우에는 $20\;{\mu}g/mL$의 농도를 첨가시 ethyl acetate 분획물이 8시간까지 강한 항산화효과를 나타내었다. Agarose gel electrophoresis에서는 에탄올, 메탄올 그리고 물 추출물 모두 항산화 효과가 인정되었다. 지질산화에 의해 생성되는 conjugated diene은 곰취 추출물의 경우 $Cu^{2+}$로 산화시켰을 때 대조에 비해 약 1.1배에서 2.8배까지 감소시키는 효과를 나타내었고 분획물의 경우 약 2.2배에서 3.2배까지의 감소효과를 나타냄으로서 강한 산화 억제효과를 나타내었다. SDS-PAGE를 이용하여 LDL내부에 존재하는 apo B-100부분에 대하여 산화에 따른 분해정도를 측정한 결과 에탄올, 메탄올 및 물 추출물이 천연 LDL의 band와 유사한 band를 나타내었다. Densitometer를 이용한 apo B-100함량은 천연 LDL의 함량을 100%로 하였을 때 에탄올, 메탄올 및 물 추출물의 경우 각각 77.8, 92.5 그리고 82.3%의 함량을 나타내었다. 분획물의 경우 헥산, ethyl acetate 및 물 분획물에서 각각 38.8, 94.5% 그리고 65.5%의 함량을 나타냄으로서 ethyl acetate 분획물이 강하게 산화를 억제함으로서 apo B-100의 분해를 막아주고 있음을 알 수 있었다.

• Bulletin of the Korean Chemical Society
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• 제35권1호
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• pp.141-146
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• 2014

A series of bimetallic Cu-Zn/$SiO_2$ catalysts were prepared via thermal decomposition of the as-synthesized $CuZn(OH)_4(H_2SiO_3)_2{\cdot}nH_2O$ hydroxides precursors. This highly dispersed Cu-solid base catalyst is extremely effective for hydrogenation of ethyl acetate to ethanol. The reduction and oxidation features of the precursors prepared by coprecipitation method and catalysts were extensively investigated by TGA, XRD, TPR and $N_2$-adsorption techniques. Catalytic activity by ethyl acetate hydrogenation of reaction temperatures between 120 and $300^{\circ}C$, different catalyst calcination and reduction temperatures, different Cu/Zn loadings have been examined extensively. The relation between the performance for hydrogenation of ethyl acetate and the structure of the Cu-solid base catalysts with Zn loading were discussed. The detected conversion of ethyl acetate reached 81.6% with a 93.8% selectivity of ethanol. This investigation of the Cu-Zn/$SiO_2$ catalyst provides a recently proposed pathway for ethyl acetate hydrogenation reaction to produce ethanol over Cu-solid base catalysts.