• Title/Summary/Keyword: OH 라디칼

Search Result 449, Processing Time 0.025 seconds

Effect of Ultrasound on the Decomposition of Sodium Dodecylbenzene Sulfonate in Aqueous Solution (Sodium Dodecylbenzene Sulfonate 수용액의 분해반응에서 초음파 효과)

  • Yim, Bong-Been
    • Journal of the Korean Chemical Society
    • /
    • v.48 no.6
    • /
    • pp.561-567
    • /
    • 2004
  • The influence of ultrasound frequency, dissolved gases, and initial concentration on the decomposition of sodium dodecylbenzene sulfonate(DBS) aqueous solution was investigated using ultrasound generator with 200 W ultrasound power. The decomposition rates at three frequencies(50, 200, and 600 kHz) examined under argon atmosphere were highest at 200 kHz. The highest observed decomposition rate at 200 kHz occurred in the presence of oxygen followed by air and argon, helium, and nitrogen. The effect of initial concentration of DBS on the ultrasonic decomposition was decreased with increasing initial concentration and would depend upon the formation of micelle in aqueous solution. It appears that the ultrasound frequency, dissolved gases, and initial concentration play an important role on the sonolysis of DBS. Sonolysis of DBS mainly take place at the interfacial region of cavitation bubbles by both OH radical attack and pyrolysis to alkyl chain, aromatic ring, and headgroup.

Antioxidant and DNA Damage Protective Activities of Freeze-Dried Blue Mussel (Mytilus edulis) (동결건조 진주담치 추출물의 항산화 및 DNA 손상 보호 활성)

  • Lee, Seon Woo;Choi, Mi-Joo;Kim, Si-Kyung;Lee, Seung-Cheol;Park, Eunju
    • Journal of the Korean Society of Food Science and Nutrition
    • /
    • v.43 no.12
    • /
    • pp.1801-1807
    • /
    • 2014
  • Blue mussels (Mytilus edulis) are widely distributed among the world's oceans in various habitats. The purpose of this study was to investigate the effects of freeze-drying on the antioxidant and antigenotoxic activities of blue mussels collected in the Gyeongnam coast area of Korea. Raw (RM) and freeze-dried blue mussel flesh (FRM) were extracted with ethanol, methanol, and water. Antioxidant activities were evaluated on the basis of DPPH radical scavenging activity, oxygen radical absorbance capacity (ORAC), cellular antioxidant capacity (CAC), and antigenotoxic activity (comet assay). Except for the water extract, RM and FRM showed DPPH radical scavenging activities, which increased upon freeze-drying in MeOH extract. The highest ORAC value was observed in water extract of RM and MeOH extract of FRM. CAC was protected against AAPH-induced oxidative stress in HepG2 cells by both RM and FRM extracts. Freeze-drying lowered ORAC value of water extract, whereas it increased CAC activity, suggesting that antioxidant activities varied according to the generated radicals. All extracts from RM and FRM showed antigenotoxic activities by reducing $H_2O_2$-induced DNA damage in human leukocytes. Freeze-drying had no effect on antigenotoxicity of blue mussels. Taken together, these results indicate that blue mussels possess antioxidant and antigenotoxic properties, and freeze-drying might be a useful processing method for blue mussels to retain their maximum physiological potential as a functional food.

Free Radical Scavenging Effect and Oxidative Stress Protective Activity of Domestic Processed Polygoni Multiflori Radix (국내산 법제 하수오의 라디칼 소거능 및 산화적 스트레스 개선 효과)

  • Kim, Hyun Young;Kim, Jun Young;Cho, Eun Ju;Choi, Ji Myung;Hwang, Chung Eun;Lee, Hee Yul;Ahn, Min Ju;Lee, Jin Hwan;Kim, Yun-Geun;Ko, Keon Hee;Goo, Young-Min;Oh, Kyeong Yeol;Cho, Kye Man
    • Journal of the Korean Society of Food Science and Nutrition
    • /
    • v.44 no.6
    • /
    • pp.809-815
    • /
    • 2015
  • In this study, we confirmed biological compounds from methanol (MeOH) extract of processed Polygoni Multiflori Radix (PPMR), and the radical scavenging effect and oxidative stress protective activity of MeOH extract of PPMR were investigated under in vitro conditions using LLC-$PK_1$ renal epithelial cells. In HPLC analysis, MeOH extract of PPMR contained four species of biological compounds named 2,3,5,4'-tetrahydroxystilbene 2-O-${\beta}$-D-glucoside, emodin, chrysophanol, and rhein. 2,3,5,4'-Tetrahydroxystilbene 2-O-${\beta}$-D-glucoside was detected as the main compound in PPMR as 115.02 mg/kg. MeOH extract of PPMR showed 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azino-bis (3-ethylbenzthiazoline-6-sulphonic acid) diammonium salt (ABTS), and hydroxyl radical scavenging activities in a concentration- dependent manner. In particular, upon $50{\mu}g/mL$ of PPMR extract treatment, DPPH, ABTS, and hydroxyl radical scavenging activities were approximately 48.4%, 57.9%, and 81.2%, respectively. LLC-$PK_1$ cell viability declined in response to oxidative stress induced by pyrogallol, sodium nitroprusside (SNP), and morpholinosydnonimine (SIN-1) generators of NO, $O_2{^-}$, and $ONOO^-$, respectively. However, MeOH extract of PPMR significantly and dose-dependently inhibited oxidative-stressed LLC-$PK_1$ cell cytotoxicity. In fact, upon $50{\mu}g/mL$ of PPMR extract treatment, LLC-$PK_1$ cell viabilities were approximately 82.1%, 89.1%, and 77.6% compared to stress levels induced by pyrogallol, SNP, and SIN-1, respectively.

The Influence of Current Flow on OH Radical Generation in a Photocatalytic Reactor of TiO2 Nanotube Plates (전류흐름에 따른 TiO2 nanotube 광촉매의 OH radical 생성량 평가)

  • Kim, Da-Eun;Lee, Yong-Ho;Kim, Dae-Won;Pak, Dae-Won
    • Journal of the Korean Applied Science and Technology
    • /
    • v.34 no.2
    • /
    • pp.349-356
    • /
    • 2017
  • OH radical generation is one of the common method to evaluate photocatalytic activity. In many of previous studies, only the UV(Ultraviolet) light was applied to test photocatalytic ability of $TiO_2$ nanotubes by studying probe compound(4-Chlorobenzoic acid) concentration change in solution. Also, $TiO_2$ nanotubes were found to show some electrochemical characteristics when the flow of electric current was applied. In this study, the flow of electric current and UV light were applied at the same time to determine whether electrochemical characteristics of $TiO_2$ nanotube plate can give synergetic effect on the photocatalytic activity. $TiO_2$ nanotube was grown on Ti by anodic oxidation to create $TiO_2$ nanotube plate which can be used as a photocatalyst and a electrode that can undergo AOP(Advanced Oxidation Process) for water treatment. Probe compound solution was prepared using 4-chlorobenzoic acid and $H_2O$ as a solvent. NaCl was added to give conductivity to work as electrolyte. As a result, enough level of electric current flow was found to give synergetic photocatalytic effect which can be used for efficient AOP water treatment method.

Evaluation of Ozone Application for Drinking Water Treatment Process Using DAF (DAF를 이용한 정수처리 공정에서의 오존 적용성 평가)

  • Kang, Tae-Hee;Oh, Byung-Soo;Cheong, Youn-Cheong;Kwon, Soon-Buhm;Sohn, Byeong-Yong;Kang, Joon-Wun
    • Journal of Korean Society of Environmental Engineers
    • /
    • v.27 no.6
    • /
    • pp.567-572
    • /
    • 2005
  • In this study, a lab-scale test was performed to apply the ozone process in drinking water treatment plant using dissolved ai, flotation(DAF). The kinetic study on the ozone decay and hydroxyl(OH) radical formation was investigated by several parameters, such as I.D(Instantaneous ozone demand), $k_c$(ozone decomposition rate), ozone-Ct and OH radical-Ct. Ozonation of several target waters, such as raw water, DAF treated water and filtrate, was conducted to select the optimum position and dosage of ozone process. The highest value of Ozone-Ct and OH radical-Ct was observed at DAF treated water at initial run time($0{\sim}30\;min$). From the results of ozonation, the intermediate ozonation was proposed as the optimum position and the effective dose of ozone was determined to be $1{\sim}2\;mg/L$.

Anti-diabetic and Anti-oxidative Activities of Extracts from Crataegus pinnatifida (산사 추출물의 항산화 및 항당뇨 활성)

  • Nam, Sang-Myeoung;Kang, Il-Jun;Shin, Mee-Hye
    • Journal of the East Asian Society of Dietary Life
    • /
    • v.25 no.2
    • /
    • pp.270-277
    • /
    • 2015
  • This study was performed to investigate the antidiabetic and antioxidant activities of Crataegus pinnatifida which was extracted with water and different concentrations of EtOH (0~100%). The extraction yield of 70% EtOH (33.16%) was higher than that of 50% EtOH (27.79%), water (21.71%), 30% EtOH (21.88%) and 100% EtOH (19.03%). Total polyphenol contents of 50% EtOH extract from C. pinnatifida were the highest. DPPH and ABTS radical scavenging activities were $80.79{\pm}0.83%$ and $34.92{\pm}0.97%$ in 50% EtOH extract, respectively, which were higher than those of other extracts. The inhibitory activities of 50% ethanol extract from C. pinnatifida against advanced glycation end products (AGEs) formation and ${\alpha}$-glucosidase were determined to be $27.09{\pm}2.27%$ and $58.87{\pm}0.70%$, respectively. The inhibitory activity of water extract from C. pinnatifida against aldose reductase was higher ($30.68{\pm}1.41%$) than those of other extracts. Overall, 50% EtOH extract from C. pinnatifida showed the highest antidiabetic and antioxidant effects. These results suggest that 50% ethanol extracts from C. pinnatifida have potential as a useful ingredient with antidiabetic and antioxidant effects.

Statistical Analysis of The Influence of Inorganic Anions on MTBE Decomposition by Photolysis(UV/H2O2) (광분해반응을 통한 MTBE 분해 시 음이온 영향의 통계적 분석)

  • Chun, Sukyoung;Chang, Soonwoong
    • Journal of the Korean GEO-environmental Society
    • /
    • v.12 no.10
    • /
    • pp.57-62
    • /
    • 2011
  • This study investigated the effects of various inorganic anions($Cl^-$, $NO_3{^-}$, $HCO_3{^-}$) on the Methyl tert Butyl Ether(MTBE) degradation by photocatalysis using statistical method. Generally, this process in general demands the generation of hydroxyl radicals(OH radical) in solution in the presence of UV light. The generation of radicals were affected by inorganic anions in solution that inhibited the photodegradation by their trapping hydroxyl radicals. The effects of inorganic anions were mathematically described as the independent variables such as $Cl^-$, $NO_3{^-}$, and $HCO_3{^-}$, and these were designed by mixture analysis that was one of the response surface methodology(RSM). Regression analysis on ANOVA showed significant p-value(p<0.0001) and high coefficients for determination value($R^2$=99.28%, ${R^2}_{adj}$=98.91%). Contour and response surface plots showed that the effects of inorganic anions for MTBE photodegradation based on $UV/H_2O_2$ process. In the result, $Cl^-$ and $HCO_3{^-}$ inhibited the photodegradation of the MTBE by their trapping hydroxyl radicals, and the interaction by these two factors was observed.

Combustion Radicals and NOx Emissions Characteristics by Control of Partially Premixed Flames (부분적 예혼합화염제어에 의한 연소 라디칼 및 NOx 배출물 특성)

  • Kim, Tae-Gwon;Jang, Jun-Yeong
    • Transactions of the Korean Society of Mechanical Engineers B
    • /
    • v.26 no.4
    • /
    • pp.561-569
    • /
    • 2002
  • This paper presents an investigation on $C_2$, CH, OH radicals and NOx emissions in partially premixed flames with acoustic excitation. The radicals are visualized by the digital image technique with optical filters and ICCD camera while NOx emissions are determined by a chemiluminescent detection(NOx analyser). The measurements are made in flames with an overall equivalence ratio (${\phi}_o$) 0.5 and a center tube equivalence ratio(${\phi}_c$) varing from 1.1 to 5.0 for a constant fuel flow rate. In the case of excitation, the visual shape of the flame is changed from laminar to turbulent-like flames. Images of $C_2$, CH, and OH radicals resemble those of the flame appearances as the excitation phase is varied, and the radicals generated at the upstream are convected toward the downstream. It is inferred that the flame characteristics is affected by the flow characteristics of air-fuel mixture. In the case of acoustic excitation, OH radicals are much increased relative to unexcitation. From the radicals and flame visualization under acoustic excitation, the reduction of flame length affects the shorter residence time of center tube mixture, and significantly influences the NOx reduction.

Effects of Oxygen-Derived Free Radicals on Brain Microsomal $Na^+-K^+-ATPase$ Activity (산소유리라디칼이 뇌조직 미크로좀분획의 $Na^+-K^+-ATPase$ 활성도에 미치는 영향)

  • Oh, Sae-Moon;Son, Young-Sook;Choi, Kil-Soo;Lim, Jung-Kyoo;Chung, Myung-Hee
    • The Korean Journal of Pharmacology
    • /
    • v.18 no.2
    • /
    • pp.1-14
    • /
    • 1982
  • The effects of xanthine-xanthine oxidase reaction on brain microsomal $Na^+-K^+-ATPase$ activity were studied to see possible involvement of oxygen free radicals in pathologic change occurring in ischemic state of CNS accompanied by cerebral vascular occlusion or impact injury. When microsomal fraction was incubated with xanthine ana xanthine oxidase, $Na^+-K^+-ATPase$ activity of the fraction was markedly inactivated (80% inactivation) whereas btssl $Mg^{++}-ATPase$ was much less sensitive (less than 10% inactivation) compared to that of $Na^+-K^+-ATPase$. The inactivation was observed only in the presence of both xanthine and xanthine oxidase, not either of them alone, and the extent of inactivation was dependent on the concentration of xanthine. In an attempt to determine which of the oxygen species was responsible for the inactivation, the ability of various scavengers to overcome the inactivation was tested. Superoxide dismutase, catalase and 1,4-diazabicyclo(2,2,2)octane were shown to reverse the inactivation of the ATPase in dose-dependent manner. In contrast, mannitol as well as other $OH{\cdot}$quenchers were ineffective in limiting oxygen radical-induced inactivation. Thus $O_{\bar{2}}{\cdot},\;H_2O_2$ and $^1O_2$ were implicated to be mediators involved in the inactivation. Since oxygen radicals are suspected as being a cause of the peroxidative damaging process in train ischemia, the ATPase inactivation by oxygen radicals may be a possible contributing factor which gives rise to functional derangement of nerve cells observed in the pathologic process.

  • PDF

OH Radical Distribution and Sooting Characteristics in Co-Flow Diffusion Flames (동축류 확산화염의 OH 라다칼 분포 및 매연 특성)

  • Lee, Won-Nam;Song, Young-Hoon;Cha, Min-Suk
    • 한국연소학회:학술대회논문집
    • /
    • 1997.06a
    • /
    • pp.1-11
    • /
    • 1997
  • The soot and OH radical distributions have been experimentally studied in ethylene and propane laminar diffusion flames. The integrated soot volume fraction was measured along the centerline of a flame using a laser light extinction method. Planar laser light scattering and PLIF techniques are employed for the soot and OH radical distribution measurements utilizing Nd:YAG laser and OPO, FDO system. The concentration of OH radical is rapidly decreased at the edge of sooting region, which implies the importance of OH radical species on the soot oxidation process. For ethylene flames, the addition of air in fuel moves the OH radical distribution towards the center line of a flame at the soot oxidation region, while the concentration of OH radical remains relatively high at the soot formation region. The interaction between soot particles and OH radicals becomes more active with fuel-air at the soot oxidation region. For propane flames, however, any indication of the increased interaction between soot particles and OH radicals with fuel-air was not noticed.

  • PDF