• Title/Summary/Keyword: Radical density

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FTIR characterization and antioxidant activity of water soluble crude polysaccharides of Sri Lankan marine algae

  • Fernando, I.P. Shanura;Sanjeewa, K.K. Asanka;Samarakoon, Kalpa W.;Lee, Won Woo;Kim, Hyun-Soo;Kim, Eun-A;Gunasekara, U.K.D.S.S.;Abeytunga, D.T.U.;Nanayakkara, Chandrika;de Silva, E.D.;Lee, Hyi-Seung;Jeon, You-Jin
    • ALGAE
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    • v.32 no.1
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    • pp.75-86
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    • 2017
  • Polysaccharides of marine algae exhibit different structural characteristics and interesting biological functions. In this study, crude polysaccharides (CP) of eleven Sri Lankan marine algae obtained through hot water extraction and ethanol precipitation were investigated for DPPH, alkyl, and hydroxyl radical scavenging activities using electron spin resonance spectrometry and for intracellular reactive oxygen species scavenging activity in the Chang liver cell line. Characterization of CPs was done by Fourier transform infrared (FTIR) spectroscopy and by analysis of the monosaccharide composition. Time-dependent density functional theory quantum-chemical calculations at the RB3LYP/6-31G(d,p) level for constructed dimeric units of the corresponding polysaccharides were used to resolve the FTIR spectra. CPs from Chnoospora minima showed the highest DPPH and alkyl radical scavenging activities and higher intracellular reactive oxygen species scavenging effects for both AAPH and $H_2O_2$ induced ROS production in "Chang" cells. The major polysaccharide constituent in C. minima CP was identified as fucoidan and it displayed a higher sulfate content. The degree of sulfation of these polysaccharides suggests a positive correlation with the observed antioxidant properties.

Antioxidant Activity and Quality Characteristics of American Cookies Prepared with Job's Tears(Coix lachryma-jobi L.) Chungkukjang Powder and Wheat Bran Powder (율무 청국장 분말과 밀겨 분말을 활용한 아메리칸 쿠키의 항산화 활성과 품질 특성)

  • Lee, Hye-Jeong;Pak, Hee-Ok;Jang, Jae-Seon;Kim, Sung-Su;Han, Chan-Kyu;Oh, Jae-Bok;Do, Wan-Yeo
    • The Korean Journal of Food And Nutrition
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    • v.24 no.1
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    • pp.85-93
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    • 2011
  • Job's tears(Coix lachryma-jobi L.) chungkukjang powder and wheat bran powder were added to American cookies for practical use as healthy compounds. We examined the antioxidant activity and quality characteristics of cookies prepared with different amounts(as ratios of 10%, 20%, 25% to the flour quantity) of Job's tears chungkukjang & wheat bran powder. The antioxidant activity was estimated by DPPH free radical scavenging activity, the total phenolic compounds content and flavonoid content in Job's tears chungkukjang & wheat bran powder and cookies. The quality characteristics of Job's tears chungkukjang & wheat bran powder American cookie were estimated in terms of bulk density, pH of the dough, spread ratio, color, texture profile analysis, proximate composition, and sensory evaluations. While the spread ratio and the total polyphenol contents, flavonoid contents and DPPH free radical scavenging activity of cookies significantly increased, pH, hardness and L value of the cookies decreased with increasing Job's tears chungkukjang & wheat bran powder(p<0.01). The consumer acceptability score for the 10~20% Job's tears chungkukjang & wheat bran powder American cookie ranked significantly(p<0.05) higher than those of the other groups in texture andoverall preference. This suggests that Job's tears chungkukjang and wheat bran powder are good ingredient candidates for increasing consumer acceptability and functionality of cookies.

A Simple $H\ddot{u}ckel$ Approach to Intramolecular Photocyclization Reaction of N-(2-Chlorobenzyl)-Pyridinium, N-(Benzyl)-2-Chloropyridinium, and N-(2-Chlorobenzyl)-2-Chloropyridinium Salts

  • Lee, Gang-Ho;Park, Yong-Tae
    • Bulletin of the Korean Chemical Society
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    • v.15 no.10
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    • pp.857-860
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    • 1994
  • We have calculated the ${\pi}$-electron density, atom self-polarizability, and free valence on each atom of N-(2-chlorobenzyl)-pyridinium, N-(benzyl)-2-chloropyridinium, and N-(2-chlorobenzyl)-2-chloropyridinium salts using a simple Huckel method in order to discuss their intramolecular photocyclization reaction in a qualitative method. Our calculation qualitatively predicts that photocyclization occurs through forming radicals as a reaction intermediate by breaking a C-Cl bond after photoexcitation into a triplet state via intersystem crossing from an initially excited singlet state. We noticed that this C-Cl bond breaking is aided by ${\pi}$-complex formation between a chlorine atom and the ${\pi}$ -electrons of the neighboring ring in the triplet state and a stronger ${\pi}$-complex bond makes C-Cl bond breaking, i.e., radical formation, much easier. A chlorine atom will form a stronger ${\pi}$ -complex bond to a benzyl ring of N-(benzyl)-2-chloropyridinium than a pyridinium ring of N-(2-chlorobenzyl)-pyridinium because the former can donate its ${\pi}$-electron more easily than the latter. The chlorine at position 15 of N-(2-chlorobenzyl)-2-chloropyridinium salt in the excited state also provides its ${\pi}$-electron to the benzyl ring. So this ${\pi}$-electron can increase the bond strength of the $\pi-complex.$ Therefore, the strength of ${\pi}$-complex follows the order of N-(2-chlorobenzyl)-2-chloropyridinium, N-(benzyl)-2-chloropyridinium, and N-(2-chlorobenzyl)-pyridinium salts and thus the radical formation rate. This provides us with an intramolecular photocyclization reaction rate of the same order as given above.

Three-dimensional Electrochemical Oxidation process using Nanosized Zero-valent Iron/Activated carbon as Particle electrode and Persulfate (나노영가철/활성탄 입자전극과 과황산을 이용한 3차원 전기화학적 산화공정)

  • Min, Dongjun;Kim, Cheolyong;Ahn, Jun-Young;Cho, Soobin;Hwang, Inseong
    • Journal of Soil and Groundwater Environment
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    • v.23 no.6
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    • pp.104-113
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    • 2018
  • A three-dimensional electrochemical process using nanosized zero-valent iron (NZVI)/activated carbon (AC) particle electrode and persulfate (PS) was developed for oxidizing pollutants. X-ray diffraction (XRD), scanning electron microscopy with energy dispersive spectroscopy (SEM-EDS), and Brunauer-Emmett-Teller (BET) surface area analysis were performed to characterize particle electrode. XRD and SEM-EDS analysis confirmed that NZVI was impregnated on the surface of AC. Compared with the conventional two-dimensional electrochemical process, the three-dimensional particle electrode process achieved three times higher efficiency in phenol removal. The system with current density of $5mA/cm^2$ exhibited the highest phenol removal efficiency among the systems employing 1, 5, and $10mA/cm^2$. The removal efficiency of phenol increased as the Fe contents in the particle electrode increased. The particle electrode achieved more than 70% of phenol removal until it was reused for three times. The sulfate radical played a predominant role in phenol removal according to the radical scavenging test.

Effects of Electrodeposition Parameters on Electrochemical Hydroxyl Radical Evolution of PbO2 Electrode (이산화납 전극 제조 시 전기화학적 증착인자가 수산화라디칼 발생에 미치는 영향)

  • Shim, Soojin;Yoon, Jeyong
    • Journal of Korean Society of Environmental Engineers
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    • v.38 no.12
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    • pp.647-655
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    • 2016
  • Lead dioxide ($PbO_2$) is an electrode material that is effective for organic pollutant degradation based on hydroxyl radical ($^{\bullet}OH$) attack. Representative parameters for $PbO_2$ electrodeposition are summarized to current, temperature, reaction time, concentration of Pb(II) and electrolyte agent. In this study, $Ti/PbO_2$ electrodes were fabricated by electrodeposition method under controlled reaction time, current density, temperature, concentration of $HNO_3$ electrolyte. Effects of deposition parameters on $^{\bullet}OH$ evolution were investigated in terms of electrochemical bleaching of p-Nitrosodimethylaniline (RNO). As major results, the $^{\bullet}OH$ evolution was promoted at the $PbO_2$ that was deposited in longer reaction time (1-90 min), lower current density ($0.5-50mA/cm^2$), higher temperature ($5-65^{\circ}C$) and lower $HNO_3$ concentration (0.01-1.0 M). Especially, the $PbO_2$ which was deposited in 0.01 M of lowest $HNO_3$ concentration by applying $20mA/cm^2$ for above 10 min was most effective on $^{\bullet}OH$ evolution. The performance gap between $PbO_2$s that was best and worst in $^{\bullet}OH$ evolution was about 41%. Among the properties of $PbO_2$ related on $^{\bullet}OH$ evolution performance, conductivity of $Ti/PbO_2$ significantly influenced on $^{\bullet}OH$ evolution. The increase in conductivity promoted $^{\bullet}OH$ evolution. In addition, the increase in crystal size of $PbO_2$ interfered $^{\bullet}OH$ evolution at surface of some $PbO_2$ deposits.

Quality Characteristics of Cookies added with Kale Powder (케일 분말 첨가 쿠키의 품질특성)

  • Lee, Jeong-Ae
    • Culinary science and hospitality research
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    • v.21 no.3
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    • pp.40-52
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    • 2015
  • This study investigated the quality characteristics of cookies containing Kale powder, which is well known for its various functions and biological activity. In this study, we assessed the quality characteristics and antioxidant activity of cookies containing various concentrations (0, 3, 5, 7 and 9%) of kale powder(KP). To analyze quality characteristics, density and pH of dough, spread factor, moisture content, color(L, a, b), hardness, DPPH radical scavenging activity and sensory properties were measured. The spread factor and DPPH radical scavenging activity of the cookies significantly increased with increasing concentrations of KP, whereas pH and density of the dough, L value of the cookies significantly decreased. The results of sensory properties showed that cookies made with 3% and 5% KP did not differ significantly from the control in color, taste, and overall quality. Texture scores for the 3% and 5% KP groups ranked significantly higher than those of the other groups. Taken together, the results of this study suggest that KP is a beneficial ingredient for increasing the consumer acceptability and functionality of cookies. The quality characteristics of the 3% and 5% added samples exhibited significantly similar or higher values as compared to those of the controls, raising the possibility of developments in health-functional cookies. The results of the sensory evaluation produced very significant values for color, appearance, texture, and overall quality of instrumental analysis.

Characteristics of Decomposition for Refractory Organic Compounds in Aqueous Solution by Sonolysis and Electrolysis (초음파와 전기분해를 이용한 수중의 난분해성 유기물질의 분해 특성)

  • Jeong, Jae-Baek;Lee, Seong-Ho;Bae, Jun-Ung
    • Journal of the Korean Chemical Society
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    • v.50 no.6
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    • pp.454-463
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    • 2006
  • refractory organic compounds in aqueous solution are not readily removed by the existing conventional wastewater treatment process. In recent years, the sonolysis and electrochemical oxidation process had been shown to be promising for wastewater treatment due to the effectiveness and easiness in operation. This study was performed to investigate the characteristics of sonolytic and electrolytic decomposition as the basic data for development of the wastewater treatment process. Trichloroethylene(TCE) and 2,4- dichlorophenol(2,4-DCP) were used as the samples, and their destruction efficiency were measured with various operating parameters, such as initial solution concentration, initial solution pH, reaction temperature, sonic power and current density. Also, the decomposition mechanism conformed indirectly with the effect of NaHCO3 as a radical scavenger on the decomposition reaction. Thermal decompositon reaction is predominant for TCE but thermal and radical decompositon reactions were dominant for 2,4-DCP. Results showed that the destruction efficiencies of all samples were above 65% within 120 minutes by sonolysis and electrolysis at the same time, and were increased with increasing initial concentration, sonic power and current density. Destruction efficiency of TCE was high in the acidic solution, but 2,4-DCP showed high destruction efficiency in basic solution.

Simultaneous Analysis of Bangpungtongseong-san and Its Antioxidant Effect (방풍통성산의 동시분석 및 항산화 효능 연구)

  • Seo, Chang-Seob;Kim, Ohn Soon;Shin, Hyeun-Kyoo
    • Herbal Formula Science
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    • v.21 no.2
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    • pp.133-143
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    • 2013
  • Objectives : We carry out the simultaneous quantification for quality control of four components in Bangpungtongseong-san (BPTSS) sample. In addition, we assessed the antioxidant effects of BPTSS sample. Methods : The used column for separation and analysis of four compounds was Luna C18 column and column oven temperature was maintained at $40^{\circ}C$. The mobile phase for simultaneous determination consisted of two solvent systems, 1.0% acetic acid in water and 1.0% acetic acid in acetonitrile. High performance liquid chromatography-photodiode array (HPLC-PDA) method for analysis was performed at a flow rate of 1.0 mL/min with PDA detection at 254 and 280 nm. The injection volume was 10 ${\mu}L$. The antioxidant activities of BPTSS were evaluated by measuring free radical scavenging activities on 2,2'-Azinobis-3-ethyl-benzothiazoline-6-sulfonic acid (ABTS) and 1-1-diphenyl-2-picrylhydrazyl (DPPH). The inhibitory effects on low-density lipoprotein (LDL) oxidation were evaluated by the formation of thiobarbituric acid relative substances (TBARS) and relative electrophoretic mobility (REM). Results : Calibration curves were acquired with $r^2{\geq}0.9999$. The values of limit of detection (LOD) and quantification (LOQ) were 0.06-0.29 ${\mu}g/mL$ and 0.20-0.98 ${\mu}g/mL$, respectively. The amounts of geniposide, liquiritin, baicalin, and glycyrrhizin in BPTSS were 5.06, 7.33, 27.56, and 7.81 mg/g, respectively. The BPTSS showed the radical scavenging activity in a dose-dependent manner. The concentration required for 50% reduction (RC50) against ABTS and DPPH radicals were 72.51 ${\mu}g/mL$ and 128.49 ${\mu}g/mL$. Furthermore, GMGHT reduced the oxidation properties of LDL induced by CuSO4. Conclusions : The established HPLC-PDA method will be helpful to improve quality control of BPTSS. In addition, BPTSS has potentials as therapeutic agent on anti-atherosclerosis.

Quality Characteristics of Cookies added with Aster yomena Powder (쑥부쟁이 분말 첨가 쿠키의 품질특성)

  • Lee, Jeong-Ae
    • Culinary science and hospitality research
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    • v.21 no.2
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    • pp.141-153
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    • 2015
  • We investigated the feasibility of incorporating Aster yomena powder into cookies as a value-added food ingredient. In this study, we assessed the quality characteristics and antioxidant activity of cookies containing various concentrations (0, 3, 5, 7 and 9%) of Aster yomena powder(AYP). For the analysis, quality characteristics such as density and pH of dough, spread factor, moisture content, color(L, a, b), hardness, DPPH radical scavenging activity and sensory properties were measured. The Hardness and DPPH radical scavenging activity of the cookies significantly increased with increasing concentrations of AYP, whereas pH and density of the dough, L value of the cookies significantly decreased. The results of sensory properties showed that cookies made with 3% and 5% AYP did not differ significantly from the control in color, taste, and overall quality. Texture scores for the 3% and 5% AYP groups ranked significantly higher than those of the other groups. Taken together, the results of this study suggest that AYP is a beneficial ingredient for increasing the consumer acceptability and functionality of cookies. The quality characteristics of the 3% and 5% added samples exhibited significantly similar or higher values as compared to those of the controls, raising the possibility of developments in health-functional cookies. The results of the sensory evaluation produced very significant values for color, appearance, texture, and overall quality of instrumental analysis.

Antioxidant Activity and Quality Characteristics of Black Rice Bran Cookies (흑미 미강 쿠키의 항산화활성 및 품질특성)

  • Joo, Shin-Youn;Choi, Hae-Yeon
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.41 no.2
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    • pp.182-191
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    • 2012
  • Black rice bran powder has potential medical uses and functionality. In this study, we assessed the antioxidant activity and quality characteristics of cookies containing various concentrations (0, 1, 3, 5, 7, and 9%) of black rice bran powder. To analyze quality characteristics, proximate composition, fatty acid composition, amino acid composition, bulk density and pH of the dough, spread factor, loss rate, leavening rate, color, texture profile analysis, and sensory evaluations were measured. Black rice bran cookies (7%) contained more crude protein ($10.67{\pm}0.33$%) compared to control ($5.84{\pm}0.06$%). The total unsaturated fatty acid contents of the control and 7% black rice bran cookies were 30.44 and 30.81%, respectively. The amino acid content of 7% black rice bran cookie was higher than that of control. Bulk density of the dough, moisture, spread factor, total polyphenol content, and DPPH free radical scavenging activity of the cookies significantly increased with increasing content of black rice bran powder, whereas pH of the dough, loss rate, leavening rate, and L values of the cookies decreased. Additionally, consumer acceptability scores for the 7% black rice bran cookie group ranked significantly higher than those of the other groups in terms of appearance, taste, flavor, texture, and overall preference. Taken together, the results of this study suggest that black rice bran powder is an effective ingredient for increasing the consumer acceptability and functionality of cookies.