• Title/Summary/Keyword: 에탄올 산화

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The antioxidative effects of Ampelopsis brevipedunculata extracts (개머루덩굴 추출물의 항산화 효과)

  • Rhim, Tae-Jin;Choi, Moo-Young
    • Korean Journal of Plant Resources
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    • v.23 no.5
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    • pp.445-450
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    • 2010
  • This study was carried out to investigate the antioxidative capacity of Ampelopsis brevipedunculata 95% ethanol extracts. The concentration of A. brevipedunculata extract at which DPPH radical scavenging activity was inhibited by 50% was 0.42 mg/mL as compared to 100% by pyrogallol as a reference. Total antioxidant status was examined by total antioxidant capacity against ABTS radical reactions. Total antioxidant capacities of A. brevipedunculata extract at the concentrations of 0.1 and 1 mg/mL were 0.65 and 3.71 mM Trolox equivalents, respectively. Oxygen radical absorbance capacities of A. brevipedunculata extract at the concentrations of 5 and $100\;{\mu}g/mL$ were 22.75 and $131.25\;{\mu}M$ gallic acid equivalents, respectively. Superoxide scavenging activities of A. brevipedunculata extract at the concentrations of 0.1 and 1 mg/mL were 27.7 and 56.0%, respectively. Total phenolic contents of A. brevipedunculata extract at the concentrations of 0.5 and 2.0 mg/mL were 0.55 and 2.06 mM gallic acid equivalents, respectively. A. brevipedunculata extract at the concentration of 0.1 mg/mL inhibited 0.2 mM and 0.5 mM tert-butyl hydroperoxide induced cyototoxicity by 36.2 and 23.3%, respectively, in HepG2 cell culture system. Thus strong antioxidant and cytotoxicity-inhibiting effects of A. brevipedunculata extract seem to be due to, at least in part, the prevention from free radicals-induced oxidation as well as high levels in total phenolic contents.

A Study on the Properties of Condensed Ethyl Silicate Synthesized according to Water Contents in Ethanol (에탄올의 수분함량에 따라 합성된 Condensed Ethyl Silicate의 물성에 관한 연구)

  • Rho, Jae-Seong;Hong, Seong-Su;Seo, Shin-Seok
    • Applied Chemistry for Engineering
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    • v.7 no.1
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    • pp.91-100
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    • 1996
  • Condensed ethyl silicate(CES) solutions were prepared from $SiCl_4$ and ethanol which is different in water content(2.5, 5.0 and 7.0wt.% ). To investigate the sol-gel transition behaviors of CES and PHT(partially hydrolyzed TEOS) solutions, the measurement of volume change, density, $SiO_2$ content, intrinsic viscosity and number average molecular weight were conducted with elapsed time. The polymer shapes of CES were discussed from the relation between the intrinsic viscosity[$\eta$] and the number average molecular weight($\bar{Mn}$). CES-3 prepared from ethanol containing 7.0wt.% $H_2O$ had different sol-gel transition behaviors from CES-1 (2.5wt.% $H_2O$) and CES-2(5.Owt.% $H_2O$), but similar behaviors to those of PHT which is used for controlling the hydrolysis rata of TEOS when composite ceramic materials were manufactured from silicon alkoxides. On the basis of Mark-Hawink relation, $[{\eta}]=K\bar{Mn}^{{\alpha}}$, the polymer shape of CES solutions were determined linear siloxane polymers because all solutions had ${\alpha}$ values in the range from 0.53 to 0.84. Especially, CES-3 showed to be a favorable raw materials for composite ceramics due to its similar properties to those of PHT.

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Antioxidant Activity of Various Solvent Extracts Obtained from A Maillard-type Browning Reaction Mixture (각종용매(各種溶媒)로부터 추출(抽出)한 Maillard형(型) 갈색화반응(褐色化反應) 생성물(生成物)의 산화억제작용(酸化抑制作用))

  • Won, Jong-Tai;Kim, Dong-Hoon
    • Korean Journal of Food Science and Technology
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    • v.12 no.4
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    • pp.235-241
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    • 1980
  • Equal portions of a Maillard-type browning mixture (0.2 M glucose+0.2 M glycine), heated at $100^{\circ}C$ for 12 hr, were extracted with the same amounts of eight solvents, respectively. The extracts were then dissolved in equal amounts of an edible soybean oil, and the resulting substrates and a portion of the soybean oil (Control) were stored in an incubator kept at $45.0{\pm}1.0^{\circ}C$ for three weeks. Peroxide values and TBA values of Control and the substrates were determined regularly during the storage period. The POVs of Control and the substrates containing acetone, benzene, chloroform, ethanol, diethyl ether, methanol, methylene chloride, and petroleum ether extracts after 12 days of storage were respectively $60.0{\pm}3.6$, $31.9{\pm}0.9$, $37.6{\pm}2.2$, $48.1{\pm}1.1$, $11.9{\pm}1.3$, $4.85{\pm}0.4$, $11.5{\pm}1.0$, $45.3{\pm}0.3$, and $43.3{\pm}4.2\;m.\;mole/kg\;oil$. The TBA values after 16 days of storage were respectively $0.28{\pm}0.02$, $0.20{\pm}0.01$, $0.21{\pm}0.01$, $0.26{\pm}0.03$, $0.16{\pm}0.02$, $0.28{\pm}0.02$, $0.17{\pm}0.01$, $0.33{\pm}0.05$, and $0.31{\pm}0.02$. The induction periods (arbitrarily taken as the time in hours for a substrate to reach a peroxide value of 30 m. mole/kg oil) of Control and the substrates were respectively 193, 280, 252, 220, 478, 229, 455, 217, and 214 hr. The antioxidant activity of each extract estimated on the basis of the length of the induction periods was, in decreasing order, as follows; ethanol>methanol>acetone>benzene>diethyl ether>chloroform, pertroleum ether, methylene chloride.

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Antioxidant Activity of the Ethanol Extract from Cooking Drips of Thunnus thynnus by Gamma Irradiation (참치 자숙액의 항산화 활성에 감마선 조사가 미치는 영향)

  • Lee, Hee-Sub;Kim, Hyun-Joo;Choi, Jong-Il;Kim, Jae-Hun;Kim, Jin-Gyu;Chun, Byung-Soo;Ahn, Dong-Hyun;Chung, Young-Jin;Kim, Yeung-Ji;Byun, Myung-Woo;Lee, Ju-Woon
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.37 no.6
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    • pp.810-814
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    • 2008
  • This study was conducted to examine the effect of a gamma irradiation on the antioxidant activity of ethanol extract from cooking drips of Thunnus thynnus (ECT). The electron donating ability against 1,1-diphenyl- 2-picryl-hydrazyl (DPPH), authentic hydroxyl radical scavenging activity by Ultra Weak Luminescence Analyzer, oxidative protection factors by Racimat method, ferric reducing antioxidant power (FRAP), and ${\beta}$-carotene bleaching activity were measured as indices of antioxidant activity. All of the results shown that irradiation increased the antioxidant activity of ECT. These results suggested that ECT could be used as an antioxidative component in food and gamma irradiation could enhance these antioxidative properties.

Programmed APTES and OTS Patterns for the Multi-Channel FET of Single-Walled Carbon Nanotubes (SWCNT 다중채널 FET용 표면 프로그램된 APTES와 OTS 패턴을 이용한 공정에 대한 연구)

  • Kim, Byung-Cheul;Kim, Joo-Yeon;An, Ho-Myoung
    • The Journal of Korea Institute of Information, Electronics, and Communication Technology
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    • v.8 no.1
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    • pp.37-44
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    • 2015
  • In this paper, we have investigated a selective assembly method of single-walled carbon nanotubes (SWCNTs) on a silicon substrate using only photolithographic process and then proposed a fabrication method of field effect transistors (FETs) using SWCNT-based patterns. The aminopropylethoxysilane (APTES) patterns, which are formed for positively charged surface molecular patterns, are utilized to assemble and align millions of SWCNTs and we can more effectively assemble on a silicon (Si) surface using this method than assembly processes using only the 1-octadecyltrichlorosilane (OTS). We investigated a selective assembly method of SWCNTs on a Si surface using surface-programmed APTES and OTS patterns and then a fabrication method of FETs. photoresist(PR) patterns were made using photolithographic process on the silicon dioxide (SiO2) grown Si substrate and the substrate was placed in the OTS solution (1:500 v/v in anhydrous hexane) to cover the bare SiO2 regions. After removing the PR, the substrate was placed in APTES solution to backfill the remaining SiO2 area. This surface-programmed substrate was placed into a SWCNT solution dispersed in dichlorobenzene. SWCNTs were attracted toward the positively charged molecular regions, and aligned along the APTES patterns. On the contrary, SWCNT were not assembled on the OTS patterns. In this process, positively charged surface molecular patterns are utilized to direct the assembly of negatively charged SWCNT on SiO2. As a result, the selectively assembled SWCNT channels can be obtained between two electrodes(source and drain electrodes). Finally, we can successfully fabricate SWCNT-based multi-channel FETs by using our self-assembled monolayer method.

The Antioxidative Effects of Rhododendron brachycarpum Extracts (만병초(Rhododendron brachycarpum) 추출물의 항산화 효과)

  • Rhim, Tae-Jin;Choi, Moo-Young
    • Korean Journal of Plant Resources
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    • v.24 no.4
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    • pp.456-460
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    • 2011
  • The objective of this study was to investigate the antioxidative capacity of Rhododendron brachycarpum 95% ethanol extracts. Total antioxidant status was examined by total antioxidant capacity against ABTS radical reactions. Total antioxidant capacities of R. brachycarpum extract at the concentrations of 0.2 and 1 mg/mL were 0.33 and 2.26 mM Trolox equivalents, respectively. Superoxide scavenging activities of R. brachycarpum extract at the concentrations of 0.2 and 1 mg/mL were 45.0 and 77.0%, respectively. Oxygen radical absorbance capacities of R. brachycarpum extract at the concentrations of 5 and 100 ${\mu}g/mL$ were 40.88 and 131.00 ${\mu}M$ Trolox equivalents, respectively. Total phenolic contents of R. brachycarpum extract at the concentrations of 0.2 and 1 mg/mL were 0.37 and 1.25 mM gallic acid equivalents, respectively. R. brachycarpum extract at the concentration of 0.1 mg/mL inhibited 0.2 mM and 0.5 mM tert-butyl hydroperoxide induced cyototoxicity by 52.1 and 30.3%, respectively, in HepG2 cell culture system. Thus, strong antioxidant and cytotoxicity-inhibiting effects of R. brachycarpum extract seem to be due to, at least in part, the prevention from free radicals-induced oxidation as well as high levels in total phenolic contents.

Synergistic Effect of Rhus javanica Linne Ethanol Extract Containing Several Synergist (항산화 효과가 있는 붉나무 추출물의 몇가지 synergist 첨가 효과)

  • Chang, Young-Sang;Choi, Ung;Shin, Dong-Hwa;Shin, Jae-Ik
    • Korean Journal of Food Science and Technology
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    • v.24 no.2
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    • pp.149-153
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    • 1992
  • Antioxidative effects of crude ethanol extract of the Rhus javanica L. and its fractionates with various synergists on the oxidation of palm oil, lard and soybean oil were compared with induction period(IP) using a Rancimat test. Addition of 200 ppm of the crude extract with phosphoric acid to palm oil extended IP 2.89 times as much as that of control and ethyl acetate fractionate extended IP 4.18 times at the same condition. To lard, 600 ppm of chloroform fraction with 200 ppm of ${\delta}-Tocopherol$ extended IP 13.42 times as much as that of control. 200 ppm of each fraction with various synergists were added to palm oil and lard, and oxidative stability of the oils were monitored by measuring POV, AV, and TBA value. The POV of palm oil containing 200 ppm of ethyl acetate and chloroform fraction with 200 ppm of phosphoric acid after 27 days storage at $60^{\circ}C$ were 8.9 meq/kg and 9.4 meq/kg respectively while the POV of control was 98.3 meq/kg at the same condition. AV and TBA value were also lower than that of control. The POV value of lard containing same amount of ethyl acetate and chloroform fraction with ${\delta}-Tocopherol$ after 12 day storage at $60^{\circ}C$ were 20.0meq/kg and 10.7 meq/kg respectively while the POV of control was 161.1 meq/kg at the same condition. AV and TBA value were also lower than that of control.

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Binderless Consolidation of Fine Poly-Si Powders for the Application as Photovoltaic Feedstock (태양전지(太陽電池) 원재료(原材料)로 사용(使用)하기 위한 폴리실리콘 미세분말(微細粉末)의 무점결제(無粘結劑) 성형(成形))

  • Shin, Je-Sik;Kim, Dae-Suk;Kim, Ki-Young;Shon, In-Jin;Moon, Byung-Moon
    • Resources Recycling
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    • v.18 no.1
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    • pp.38-43
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    • 2009
  • In this study, binderless consolidation processes of ultra foe Si powder, by-products of making high purity poly-Si in the current method, were systematically investigated for use as economical solar-grade feedstock. The average diameter of the silicon powder was $7.8{\mu}m$. The main contaminants of the fine silicon powder were $SiO_2$ type oxide and humidity. The chemical pretreatment using the HF solution was observed to be effective for the improvement of the compactability of the silicon powder and the density ratio and the strength of the silicon powder compacts. The yield of the binder-free consolidation process increased by 20% under a vacuum condition. In as-received state, the silicon powder were not pure enough to be used as solar grade feed-stock material. After the dry chemical treatments, a sufficiently high purity above solar-grade was able to be achieved.

Validation of HPLC Methods for Ascorbic Acid and Its Derivatives in Foods (식품 중 아스코르빈산 유래 산화방지제의 HPLC 분석법 검증 및 개선)

  • Jeong, Min Kyu;Park, Chan Uk;Park, Min Hee;Yeo, JuDong;Park, SeungKwan;Kim, SoHee;Shin, Tae-Sun;Baek, Hyung Hee;Lee, JaeHwan
    • Food Engineering Progress
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    • v.15 no.1
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    • pp.75-79
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    • 2011
  • Analytical methods for food antioxidants including ascorbic acid, erythorbic acid, ascorbyl palmitate (AP), and ascorbyl stearate (AS), were validated using high performance liquid chromatography. Validation parameters such as linearity, limit of detection (LOD), limit of quantification (LOQ), and recovery were tested using lard and cider as food model systems. Linearity of ascorbic acid and erythorbic acid were both higher than ($R^2$> 0.99), LOD of these compounds were 0.46 and 0.48 ${\mu}g/mL$, respectively and LOQ were 1.39 and 1.45 ${\mu}g/mL$, respectively. The recovery rates of these compounds were 86.35-94.78% and 84.76-95.02%, respectively. However, the concentration of AP and AS decreased in methanol stock solution. Four other solvents including ethanol, acetonitrile, mixture of methanol and acetonitrile, and mixture of ethanol and acetonitrile were tested to increase the stability of AP and AS under room temperature and refrigerated temperature. Ethanol provided better stability of AP and AS under both room and refrigerated temperature. This study can help to accurately analyze the content of ascorbic acid and its derivatives in processed foods.

Antioxidative and Cytotoxic Effects of Ethanol Extracts from Elaeagnus multiflora (뜰보리수 에탄올 추출물의 산화적 스트레스 억제 효과와 암세포 증식 억제 효과)

  • Oh, Se-In;Lee, Mee-Sook
    • The Korean Journal of Food And Nutrition
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    • v.21 no.4
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    • pp.403-409
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    • 2008
  • Elaeagnus multiflora, generally referred to as the cherry silverberry, is a plant. Elaeagnus multiflora fruit, leaves, and roots have been traditionally utilized in China as a treatment for cough, diarrhea, itch, and foul sores, and even cancer. More importantly, it is being investigated as a food that is capable of reducing the incidence of cancer, and also as a means of halting or reversing the growth of cancers. Considering the dearth of information regarding the medicinal properties of Elaeagnus multiflora, we assessed the antioxidative and cytotoxic effects of Elaeagnus multiflora by examining its scavenging effects on the 1,1-diphenyl-2-picryl-hydrazyl(DPPH) radical, its inhibitory effects on lipid peroxidation, and its inhibitory effects on cancer cell proliferation in HeLa cells, MCF-7 cells, and SNU-638 cells via MTT assay. Ethanol extracts of Elaeagnus multiflora flesh and seed inhibited DPPH radical production($36.91{\pm}1.00$, $94.17{\pm}0.37$) and lipid peroxidation ($28.18{\pm}5.02$, $40.30{\pm}1.45$, respectively). The Elaeagnus multiflora seed is believed to exert a possible antioxidative effects against the DPPH radical. The ethanol extracts of Elaeagnus multiflora flesh and seed exerted the cytotoxic effects on Hela cells ($6.93{\pm}1.92$, $84.97{\pm}0.47$), MCF-7 cells($5.45{\pm}0.41$, $84.97{\pm}0.47$), and SNU-638 cells($19.39{\pm}0.43$, $76.84{\pm}0.63$) used in this study. This result suggests that Elaeagnus multiflora seeds in contrast to its flesh, is believed to exert a possible anticancer effect. Elaeagnus multiflora seeds are considered to be a the candidate for preventative and dietetic treatment as an anticancer functional food.