• Title/Summary/Keyword: auto-oxidation

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Antioxidant Effect of Vitamin-C/alginate Gel-entrapped Liposome for Resistance of DHA Autoxidation (DHA의 산화방지를 위한 Vitamin C/alginate Gel-entrapped Liposome의 항산화 효과)

  • 한성철;허은정;김연주;이기영;김진철
    • KSBB Journal
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    • v.18 no.3
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    • pp.229-233
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    • 2003
  • Antioxidant effect of reconstituted liposome was studied for application to food and cosmetic industry. Vitamin-C/alginate alginate gel-entrapped DHA-PC liposome (AVDL) was prepared and studied with respect to morphology (TEM), loading efficiency (TLC) and antioxidant effect (TBARS assay). AVDL has spherical structure and 80 ∼ 250 ㎚ size. As DHA content increased, DHA and PC loading efficiency and antioxidant effect was increased. At addition of 0.2 % vitamin C in AVDL, DHA auto-oxidation was minimized and sustained about 3 days.

Selective Homocysteine Assay with Cucurbit[7]uril by pH Regulation

  • Bae, Won-Bin;Kim, Hee-Joon;Jhee, Kwang-Hwan
    • Journal of Microbiology and Biotechnology
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    • v.32 no.4
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    • pp.514-521
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    • 2022
  • We report the effect of pH on the supramolecular complexation of two biothiols, viz., homocysteine (Hcy) and cysteine (Cys), with cucurbit[7]uril (CB[7]). Under basic pH conditions, Cys did not complex with CB[7], whereas Hcy efficiently complexed with CB[7], as confirmed by 1H NMR spectroscopy and Ellman's reagent (5,5'-dithio-bis(2-nitrobenzoic acid), DTNB) assay. 1H NMR and Raman spectroscopic studies revealed that, in the absence of CB[7], Hcy auto-oxidized slowly (~36 h) to homocystine (HSSH) under basic pH conditions. However, the rate of Hcy oxidation increased by up to 150 fold in the presence of CB[7], as suggested by the DTNB assay. Thus, supramolecular complexation under basic pH conditions led to the formation of a HSSH-CB[7] complex, and not Hcy-CB[7]. The results indicate that Hcy is rapidly oxidized to HSSH under the catalysis of CB[7], which acts as a reaction chamber, in basic pH conditions. Our studies suggest that Hcy concentration, a risk factor for cardiovascular disease, can be selectively and more easily quantified by supramolecular complexation with CB [7].

Changes in Antioxidant Activity during Growth of Artemisia iwayomogi (더위지기 생육 중 항산화 활성 변화)

  • Hwang, Tay-Eak
    • Korean Journal of Medicinal Crop Science
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    • v.17 no.4
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    • pp.286-292
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    • 2009
  • The aim of this study was to investigate the effect of plant growth at several different growing periods on antioxidant activities and zeatin and ABA contents of Artemisia iwayomogi. Measurements of antioxidant activities, lipid peroxidation inhibition, and superoxide radical scavenging activity were done using PMS, NBT and lipid auto-oxidation analysis, respectively. The results show that activities of antioxidants from Artemisia iwayomogi had much higher than BHT. DPPH free radical scavenging effect of Artemisia leaf extract was increased from $71.06{\pm}4.36%$ in April to $90.06{\pm}4.41%$ in October. Activities of superoxide radical scavenging and lipid peroxidation inhibition were $33.83{\pm}3.45%$ and $45.60{\pm}3.10$ in April and then increased to $84.40{\pm}4.00%$ and $75.86{\pm}3.50%$ in October, respectively. An ELISA technique has been developed for the determination of zeatin and ABA in Artemisia leaves. By this method, the content changes of zeatin and ABA from Artemisia during the growth were investigated. The zeatin content in leaf was measured to be $186.86{\pm}1.40$ pmol/g dry weight in April, however, decreased to $117.93{\pm}5.83$ pmol in October. The ABA content in leaf increased from $19.00{\pm}1.26$ nmol in April to $68.20{\pm}2.52$ nmol in October. Relationship between antioxidant activities and plant hormone contents was indicated that antioxidant activity may depend on decreasing zeatin content or increasing ABA content.

A study on an intermittent aeration membrane bioreactor system using ammonia sensor to decrease energy consumption and sludge concentration by tubular membrane (암모니아 센서를 이용한 간헐폭기 Membrane bioreactor공정에서의 전력비 저감과 관형막을 이용한 슬러지 농축에 관한 연구)

  • Kang, Heeseok;Lee, Euijong;Kim, Hyungsoo;Jang, Am
    • Journal of Korean Society of Water and Wastewater
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    • v.28 no.2
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    • pp.161-170
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    • 2014
  • It is essential to decrease energy consumption and excess sludge to economically operate sewage treatment plant. This becomes more important along with a ban on sea dumping and exhaustion of resource. Therefore, many researchers have been study on energy consumption reduction and strategies for minimization of excess sludge production from the activated sludge process. The aeration cost account for a high proportion of maintenance cost because sufficient air is necessary to keep nitrifying bacteria activity of which the oxygen affinity is inferior to that of heterotrophic bacteria. Also, additional costs are incurred to stabilize excess sludge and decrease the volume of sludge. There were anoxic, aerobic, membrane, deairation and concentration zone in this MBR process. Continuous aeration was provided to prevent membrane fouling in membrane zone and intermittent aeration was provided in aerobic zone through ammonia sensor. So, there was the minimum oxygen to remove $NH_4-N$ below limited quantity that could be eliminated in membrane zone. As the result of this control, energy consumption of aeration system declined by between 10.4 % and 19.1 %. Besides, we could maintain high MLSS concentration in concentration zone and this induced the microorganisms to be in starved condition. Consequentially, the amount of excess sludge decrease by about 15 %.

ANTIOXIDATIVE ACTIVITIES OF SOME DIETARY FIBERS DETERMINED BY AN NIR EMISSION SPECTROSCOPY

  • Suzuki, Nobutaka;Nagai, Takeshi;Tokunou, Kazunari;Mizumoto, Iwao;Matsuya, Hiroko;Yoda, Binkoh;Itami, Toshiaki;Takahashi, Yukinori;Kozawa, Akiya
    • Proceedings of the Korean Society of Near Infrared Spectroscopy Conference
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    • 2001.06a
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    • pp.3102-3102
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    • 2001
  • Constituents of several .representative seaweeds, such as wakame Undaria pinnatifida; hijikia Hizikia fusifome; and kombu Laminaria japonica, were found to have fairly large reaction rates determined by quenching experiments of emission spectra in the near-infrared region (1max: 1270 nm) from singlet oxygen (102). Emission spectra of singlet oxygen generated from an aqueous solution of Rose Bengal under irradiation with a green laser (330 nm) were measured by a near-infrared (NIR) emission spectrometer constructed in our laboratory. The quenching experiments were as follows: Intensities of emission spectra were measured in the absence (I0) and in the presence of the seaweed constituents (I): Ratios of I0/I were plotted against every concentration of the quenchers (Stern-Volmer plots) which gives a straight line. The slope of each line gives a kqt value which gives a quenching constant kq value (an antioxidative constant against singlet oxygen) when the t value (half-life time of singlet oxygen in the solvent used) was given. The determined reaction rates are between 103-105 (g/l)-ls-1; the larger ones are as large as that of ascorbic acid, 8.4 ${\times}$ 104 (g/1)-ls-1. Most of these seaweed constituents also showed antioxidative activity against auto-oxidation and superoxide as well as their immunological enhancing activity. These results suggest a possibility that dietary fibers which are supposed to prevent the large-intestine cancer by their physical properties may prevent the cancer, at least in parts, by their chemical, antioxidative activity.

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Effect of Deodorizing Temperature on Physicochemical Characteristics in Corn Oil IV. Effect of Deodorizing Temperature on Volatile Flavor Component Composition in Corn Oil (탈취온도가 옥수수기름의 이화학적 특성에 미치는 영향 제4보, 탈취온도가 옥수수기름의 휘발성 냄새성분 변화에 미치는 영향)

  • 이근보;한명규;이미숙
    • The Korean Journal of Food And Nutrition
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    • v.11 no.3
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    • pp.272-277
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    • 1998
  • We carried out separation and guantitation of flavor components by GC about essential oils extracted from deodorized corn oil at the different deodorizing temperature. Flavor components were detected total 16 kinds included aldehydes of 8 kinds, major components were propane, pentane, hexanal etc. These major components content was about 70~75% of the total flavor components. According to rise of deodorizing temperature, both ethane and aldehydes of 8 kinds content were in proportion to increase, but propane, pentane, hexane, octan, pentyl furan content were decreased by contraries, respectively. On the other hand, total flavor component content was appeared the lowest level at 245$^{\circ}C$ treating group, aldehydes content was in proportion to increase according to rise of deodorizing temperature. These phenomenons consider that the undesirable reactions such as partial auto-oxidation, degradation, polymerization and hydrolysis etc. by effecting factors of stripping steam and vacuum degree. Conclusively, deodorizing temperature under high temperature was undesirable for the minimization of off-flavor materials.

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Studies on the Regulation of Nitric oxide Synthesis in Murine Mononuclear Phagocytes (마우스 단핵 탐식 세포에서 Nitric oxide 생성의 조절 기전에 관한 연구)

  • 최병기;김수응
    • Environmental Analysis Health and Toxicology
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    • v.15 no.3
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    • pp.69-80
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    • 2000
  • ADP-rubosylation may be involved in the process of macrophage activation. Nitric oxide (NO) has emerged as an important intracellular and interacellular regulatory molecule with function as diverse as vasodilation, neural communication or host defense. NO is derived from the oxidation of the terminal guanidino nitrogen atom of L-arginine by the NADPH -dependent enzyme, nitric oxide synthase (NOS) which is one of the three different isomers in mammalian tissues. Since NO can exert protective or regulatory functions in the cell at a low concentration while toxic effects at higher concentrations, its role may be tightly regulated in the cell. Therefore, this paper was focused on signal transduction pathway of NO synthesis, role of endogenous TGF-$\beta$ in NO production. effect of NO on superoxide formation. Costimulation of murine peritoneal macrophages with interferon-gamma (IFN-γ) and phorbol 12-myristate 13-acetate (PMA) increased both NO secretion and mRNA expression of inducible nitric oxide synthase (iNOS) when PMA abolished costimulation. Pretreatmnet of the cells with PMA abolished costimuation effects due to the depletion of protein kinase C (PKC) activities . The involvement of PKC in NO secretion could be further confirmed by PKC inhibitor, stauroprine, and phorbol ester derivative, phorbol 12,13-didecanoate. Addition of actinomycine D in IFN-γ plus PMA stimulated cells inhibited both NO secretion and mRNA expression of iNOS indication that PMA stabilizes mRNA of iNOS . Exogenous TGF-$\beta$ reduced NO secretion in IFN -γ stimulated murine macrophages. However addition of antisense oligodeoxynucleotide (ODN) to TGF-$\beta$ to this system recovered the ability of NO production and inhibited mRNA expression of TGF-$\beta$. ACAS interactive laser cytometry analysis showed that transportation of FITC -labeled antisense ODN complementary to TGF-$\beta$ mRNA could be observed within 5 min and reached maximal intensity in 30 min in the murine macrophage cells. NO released by activated macrophages inhibits superoxide formation in the same cells . This inhibition nay be related on NO-induced auto -adenosine diphosphate (ADP) -ribosylation . In addition, ADP-ribosylation may be involved in the process of macrophage activation .

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Application of tubular membrane to thickening process as a pre-treatment of anaerobic digester (관형막을 이용한 혐기소화조의 전처리 농축공정으로써 적용가능성 연구)

  • Kang, Hee-Seok;Park, Ki-Tae;Park, Jung-Woo;Kim, Hyung Soo
    • Journal of Korean Society of Water and Wastewater
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    • v.29 no.2
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    • pp.203-209
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    • 2015
  • The purpose of this study is to estimate the applicability of a stable anaerobic digester using a separator membrane to the preprocessing thickening process. The results of the experiments showed about a 47.16% weight loss rate for the sludge under anaerobic condition, and about 41.17% under intermittent aeration condition. The concentrations of rejection water were $SCOD_{Cr}$ 25 mg/L, T-N 16.6 mg/L, and T-P 1.4 mg/L on the average under the intermittent aeration condition, which were lower than the concentrations of rejection water under an anaerobic condition. As for the factors affecting the reduction of the flux, correlation analyses of TTF, MLSS, $SCOD_{Cr}$, and $EPS_{Protein}$, $EPS_{Polysacchride}$ resulted in -0.97, -0.95, -0.84 and -0.86, -0.95, respectively, which showed that TTF had the highest correlation to the reduction of the flux. In addition, it was concluded that MLSS, $SCOD_{Cr}$ and $EPS_{Protein}$, $EPS_{Polysacchride}$ also have close correlations. The results are considered to show that, in the case of the process using a tubular membrane in the preprocessing process of an anaerobic digester, an intermittent aeration condition of the thickener considering the contamination of the membrane and load of rejection water is appropriate for the stable preprocessing process.

Combustion Characteristics of Premixed Burner for Fuel Reformer (개질기용 예혼합 연소장치의 연소특성 연구)

  • Lee, Pil-Hyong;Lee, Jae-Young;Han, Sang-Seok;Park, Chang-Soo;Hwang, Sang-Soon
    • Proceedings of the KSME Conference
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    • 2008.11b
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    • pp.2181-2185
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    • 2008
  • Fuel processing systems which convert HC fuel into $H_2$ rich gas (such as stream reforming, partial oxidation, auto-thermal reforming) need high temperature environment($600-1000^{\circ}C$). Generally, anode-off gas or mixture of anode-off gas and LNG is used as input gas of fuel reformer. In order to make efficient and low emission burner system for fuel reformer, it is necessary to elucidate the combustion and emission characteristic of fuel reformer burner. The purpose of this study is to develop a porous premixed flat ceramic burner that can be used for 1-5kW fuel cell reformer. Ceramic burner experiments using natural gas, hydrogen gas, anode off gas were carried out respectively to investigate the flame characteristics by heating capacity and equivalence ratio. Results show that the stable flat flames can be established for natural gas, hydrogen gas, anode off gas and mixture of natural & anode off gas as reformer fuel. For all of fuels, their burning velocities become smaller as the equivalence ratio goes to the lean mixture ratio, and a lift-off occurs at lean limit. Flame length in hydrogen and anode off gas became longer with increasing the heat capacity.

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Screening of the Antioxidative Activity, Antimutagenicity and Mutagenicity of the Ethanolic Extracts from Legumes (두류 에탄올 추출물의 항산화 활성, 항변이원성 및 변이원성 검정)

  • Chang, Su-Min;Nam, Seok-Hyun;Kang, Mi-Young
    • Korean Journal of Food Science and Technology
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    • v.34 no.6
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    • pp.1115-1122
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    • 2002
  • To evaluate the physiological properties of 22 varieties of legumes, antioxidative activity, antimutagenicity against Mitomycin C, genotoxicity, and mutagenicity were tested. Ethanolic extracts of legumes had significant antioxidative activities in the tests of electron-donating ability to DPPH radical, hydroxy radical-scavenging activity, and inhibitory effect on lipid auto-oxidation model system. Soy sprout bean (green), mung bean, and small black bean (green) had excitatory effects on the growth of E. coli PQ 37 cell. Black bean and green soy bean had inhibitory effects on the mutagenicities of the cells. Rice bean, pea, mung bean, and bonavista bean showed antimutagenic activities against chemical mutagen, Mitomycin C. Thus, rice bean and mung bean were found to be appropriate auxiliary ingredients of rice cake and rice processing food for the promotion of health and augmentation of rice and legume consumptions.