• Title/Summary/Keyword: 1,4-Conjugated oxidation

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Electrochemical Polymerization of Ruthenium(II) Complex and Application to Acetaminophen Analysis

  • Kannan, Sethuraman;Son, Jung-Ik;Yang, Jee-Eun;Shim, Yoon-Bo
    • Bulletin of the Korean Chemical Society
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    • v.32 no.4
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    • pp.1341-1345
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    • 2011
  • A novel ruthenium(II) complex, [$RuCl_2(DMSO)_2$(PhenTPy)] has been synthesized by the condensation of $RuCl_2(DMSO)_4$ with (1-(1,10-phenanthrolinyl)-2,5-di(2-thienyl)-1H-pyrrole)[PhenTPy] in $CHCl_3$ solution. The [$RuCl_2(DMSO)_2$(PhenTPy)] complex modified electrode was fabricated through the electropolymerization of the monomer in a 0.1 M tetrabutylammonium perchlorate (TBAP)/$CH_2Cl_2$ solution, to take advantage of the electronic communication between metal ion center by the conjugated backbone. The UV-visible spectroscopy (UV), mass spectrometry (MS), and cyclic voltammetry (CV) were employed to characterize the [$RuCl_2(DMSO)_2$(PhenTPy)] complex and its polymer (poly-Ru(II)Phen complex). The poly-Ru(II)Phen complex modified electrode exhibited an electrocatalytic activity to the oxidation of acetaminophen and the catalytic property was used for the analysis of acetaminophen at the concentration range between 0.09 and 0.01 mM in a phosphate buffer solution (pH 7.0).

Effects of Ligularia fischeri Extracts on Oxidation of Low Density Lipoprotein (저밀도 지방단백질의 산화에 대한 곰취 추출물의 항산화 효과)

  • Jeong, Seong-Won;Kim, Eun-Jeong;Hwangbo, Hyun-Ju;Ham, Seung-Shi
    • Korean Journal of Food Science and Technology
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    • v.30 no.5
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    • pp.1214-1221
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    • 1998
  • The study was carried out to investigate the antioxidant effects of ethanol, methanol, and water extracts or fractions of ethanol extract of Ligularia fischeri on low density lipoprotein(LDL) and ethanol extract was further fractionated. The methanol extract and ethyl acetate fraction showed strong antioxidant effect with 71.7% (13.36 nmol/mg) and 95% (1.35 nmol/mg) inhibition in the presence of $15\;{\mu}g/mL$, respectively. In the value of malondialdehyde(MDA) with oxidation time, ethanol, methanol and water extract in the presence of $25\;{\mu}g/mL$ inhibited the oxidation up to 4h incubation and ethyl acetate fraction showed strong antioxidant effect up to 8h incubation. Also, the ethanol, methanol and water extract showed antioxidant effects in the agarose gel electrophoresis test. The conjugated diene formation by lipid oxidation with addition of $Cu^{2+}$ in the Ligularia fischeri extracts and their fractions was decreased approximately 1.1 to 2.8 times and 2.2 to 3.2 times, respectively compared to control. In the degradation of apo B-100 by oxidation using SDS-PAGE, ethanol, methanol and water extract showed similar degradation band pattern compared to that of native LDL band. Apo B-100 contents using densitometer were 77.8, 92.5% and 82.3% in the ethanol, methanol and water extract, respectively, compared to 100% of native LDL. In the meanwhile, apo B-100 contents in hexane, ethyl acetate and water fraction were 38.8, 94.5 and 65.5% respectively. This results indicated that ethyl acetate fraction showed the strongest antioxidant effect on MDA value or apo B-100 contents of LDL.

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Toasting Effects on the Lipid Oxidation, Antioxidants, and Pigments of Dried Laver (Porphyra spp.) (토스팅에 따른 김의 지방질 산화, 산화방지성분과 색소 변화)

  • Son, Soojeong;Choe, Eunok
    • Korean Journal of Food Science and Technology
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    • v.46 no.6
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    • pp.677-681
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    • 2014
  • The effects of toasting, simulated gimgui (dried and toasted laver) manufacturing, on lipid oxidation and antioxidant and pigment contents of dried laver (Porphyra spp.) were evaluated by peroxide value (POV) and conjugated dienoic acid (CDA) value measurement, HPLC, and spectrophotometry. Dried laver was toasted for 40 or 300 s at $120^{\circ}C$, or for 2 or 5 s at $250^{\circ}C$. The POV and CDA contents were significantly higher in the toasted samples (0.60-0.69 mmol/kg and 2.17-4.20%, respectively) except in samples toasted at $120^{\circ}C$ for 40 s, compared to those in the non-toasted samples (0.43 mmol/kg and 1.21%, respectively). Chlorophyll was the most stable pigment during toasting (>90% retention), followed by carotenoids (50-77% retention) and phycocyanins and phycoerythrins (13-73% retention). Porphyran was the most stable antioxidant (>95% retention), and polyphenols, the most unstable antioxidant (24-75% retention). Despite the degradation of pigments and antioxidants during toasting, the dried laver still contained health-benefiting components after toasting.

Quality characteristics of deep fat fried carrots depend on type of frying oil, frying temperature, and time of frying

  • Park, Hyun Su;Kim, Hyun Jung
    • Korean Journal of Food Science and Technology
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    • v.52 no.1
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    • pp.46-53
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    • 2020
  • Carrots were deep fat fried with sunflower oil (SO), palm oil (PO), and a blend of palm and sunflower oils (PSO with PO:SO as 2:8 or 4:6) at different temperatures (180 and 190℃) and lengths of time (0.5 to 2.5 min). The quality of deep fat fried carrots was determined by the moisture and fat content, color, conjugated dienoic acid (CDA), hydroperoxide, p-anisidine value, and fatty acid composition. The moisture content of fried carrots decreased with increasing frying time, while the fat content increased. The CDA and p-anisidine values of carrots fried with SO were higher than those fried with PO because of greater unsaturated fatty acids content in SO. PSO was a better choice than SO or PO for deep fat frying carrots in the aspects of oxidative stability and ratio of unsaturated to saturated fatty acids. These results indicate that the quality of deep fat fried carrots depends on the type of oil and frying temperature used, as well as the length of time.

Antioxidant Activity of Green Tea Extracts toward Human Low Density Lipoprotein (사람의 Low Density Lipoprotein에 대한 녹차의 항산화 활성)

  • Park, Chun-Ok;Jin, Seung-Heun;Ryu, Beung-Ho
    • Korean Journal of Food Science and Technology
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    • v.28 no.5
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    • pp.850-858
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    • 1996
  • Green tea leaves 12.5 g were extracted twice with 500 ml boiling water. The green tea extract (GTE) contained 4.67 mg solid. The GTE contained polyphenols sush as 54.12% (-) epicatechin gallate, 26.21% (-) epicatechin, 10.71% epicatechin gallate, 7.09% (-) epicatechin and 1.85% catechin. The GTE inhibited the copper-catalyzed oxidation of human LDL at the concentrations of 50 and $100\;{\mu}g/ml$ GTE in the presence of $5\;{\mu}M$ $CuSO_{4}$. The electrophoretic mobility of the LDL oxidized in the presence of $5\;{\mu}M\;CuSO_{4}$ was higher than that of the native LDL. The GTE also inhibited LDL oxidation induced by J774, human monocyte-derived macrophages and vascular endotherial cells. The LDL modified by copper or cells was inhibited by human macrophages at a much greater rate than native LDL in the presence of GTE. The GTE was found to be a potent inhibitor of modification of LDL. GTE inhibited the uptake of cell-modified $^(125)I-labelled$ LDL by macrophages. The formation of conjugated dienes was strongly inhibited in the presence of 50 or $100\;{\mu}g/ml$ GTE.

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Effect of Cordyceps ochraceostromat, Silkworm Cocoon, and Conjugated Linoleic Acid (CLA) on the Quality Characteristics of Pork Sausage Manufactured with Protein Recovered from Breast of Spent Laying Hen (폐계가슴살 회수단백질을 활용한 돈육소시지의 품질 특성에 영향하는 동충하초, 누에고치 및 Conjugated Linoleic Acid (CLA) 첨가 효과)

  • Jin, Sang-Keun;Kim, Il-Suk;Kang, Suk-Nam;Choi, Seung-Yun;Hur, In-Chul;Lee, Jung-Guen;Yang, Han-Sul
    • Journal of Animal Science and Technology
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    • v.52 no.2
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    • pp.131-140
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    • 2010
  • This study was conducted to investigate the effects of Cordyceps ochraceostromat, silkworm cocoon, and conjugated linoleic acid (CLA) on the quality and storage properties of pork sausage manufactured with protein recovered from breast of spent laying hen during 4 wks of storage at $4^{\circ}C$. Pork sausages were prepared using 100% ham (control) and 40% recovered protein from breast of spent laying hen to replace pork (T1), and with added different sources to final concentrations of 0.1% Cordyceps ochraceostromat powder (T2), 0.1% silkworm cocoon powder (T3), 0.1% CLA (T4), 0.05% Cordyceps ochraceostromat + 0.05% silkworm cocoon (T5), 0.05% Cordyceps ochraceostromat + 0.05% CLA (T6), and 0.05% silkworm cocoon + 0.05% CLA (T7). The treatments T5 and T7 had higher (p<0.05) protein content than control, but control had lower fat content than other samples during 4 wks of storage at $4^{\circ}C$. Lightness was significantly lower in the treatment samples than control. However, there was no significant difference in water holding capacity between the sausage samples, whereas, cohesiveness and chewiness were significantly higher (p<0.05) in the control than other treatments. All sausage samples showed a significant increase in volatile basic nitrogen (VBN) and total plate counts with extending storage time (p<0.05), and VBN values of treatments were lower than the control. However, the treatment samples showed a significant decrease (p<0.05) in thiobarbituric acid reactive substances over the increasing storage time. Therefore, our results suggested that the 40% recovered protein to replace pork and with added different sources decreased lipid oxidation and protein denaturation of pork sausages, thereby enhancing self-life, compared to normal pork sausage (control).

Reaction of the Fe(II) Macrocyclic Complexes with Dioxygen : Preparation of New Unsaturated Ring Systems by Oxidative Dehydrogenation Reactions of Fe(II) Macrocyclic Ligands (이가철 거대고리 리간드의 착화합물과 산소 분자간의 반응 : 이가철 거대고리 리간드 착화합물의 산화성 탈수소 반응에 의한 새로운 불포화 고리계의 합성)

  • Myunghyun Paik;Shin-Geol Kang;Kyu Whan Woo
    • Journal of the Korean Chemical Society
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    • v.28 no.6
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    • pp.384-392
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    • 1984
  • Reaction of the Fe(II) complex of a fully saturated tetradentate macrocyclic ligand [Fe([14]aneN$_4)(CH_3CN)_2]^{2+}$, where [14]ane$N_4$ represents 1,4,8,11-tetraazacyclotetradecane, with $O_2$ has been investigated in acetonitrile solutions. [Fe([14]aneN$_4)(CH_3CN)_2]^{2+}$ reacts with oxygen to yield low spin Fe(III) species, [Fe([14]aneN$_4)(CH_3CN)_2]^{3+}$, which undergoes metal ion assisted oxidative dehydrogenation of the macrocyclic ligand to produce low spin Fe(II) complex, [Fe([14]tetraeneN$_4)(CH_3CN)_2]^{2+}$. The macrocyclic ligand in [Fe([14]tetraeneN$_4)(CH_3CN)_2]^{2+}$ is highly unsaturated and its double bonds are conjugated. [Fe([14]dieneN$_4)(CH_3CN)_2]^{2+}$ and [Fe([14]dieneN$_4)(CH_3CN)_2]^{3+}$ are isolated as the intermediates of the reaction. The Fe(II) complexes involved in this oxidative dehydrogenation reaction react with carbon monoxide to give respective carbon monoxide derivatives, [FeL$(CH_3CN)(CO)]^{2+}$ (where L = macrocyclic ligand). The values of $v_{CO}$ of [FeL$(CH_3CN)(CO)]^{2+}$, and the electrochemical oxidation potentials of Fe(II) ${\to}$ Fe(III) and the qualitative stability toward air-oxidation for [FeL(CH$_3CN_2)^{2+}$ increase as the degree of unsaturation of the macrocyclic ligands increase.

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Effects of CLA-vegetable Oils and CLA-lard on TBARS, Color and Fatty Acid Composition of Emusion-type Sausage (식물성유와 동물성유 CLA가 유화형 Sausage의 지방산패도, 육색 및 지방산 조성의 변화에 미치는 영향)

  • 박구부;문성실;이정일;하영래;주선태
    • Food Science of Animal Resources
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    • v.21 no.1
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    • pp.71-79
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    • 2001
  • Emulsion-type sausages were manufactured to investigate the effects of CLA-vegetable oils and CLA-lard on quality of emulsion-type sausage. Each treatments replaced pork back fat with CLA-sesame oil (CLA-SO), CLA-lard (CLA-LD) and CLA-safflower seed oil (CLA-SSO) were stored during 1, 7, 14, 21 and 28 days at 4$^{\circ}C$. The changes in physico-chemical properties, thiobarbituric acid reactive substances(TBARS) and fatty acid composition of each treatments were measured during 1, 7, 14, 21 and 28 days at 4$^{\circ}C$. The pH values of all treatments significantly(p<0.05) decreased as storage time increased. Sausage products containing CLA-vegetable oils showed higher pH value than that of CLA-lard among the treatments. Color a*-value of CLA-SSO was higher than that of other treatments. During storage, TBARS values of treatments were significantly (p<0.05) increased, sausage products containing CLA-vegetable oils showed lower (p<0.05) TBARS value than CLA-lard, and TBARS of sausage products containing CLA-SSO was the lowest. This result indicated that CLA concentration in emulsion-type sausage did affect the lipid oxidation stability. Fatty acids composition was changed by addition of CLA-vegetable oils and CLA-lard. All kinds of fatty acids content decreased whereas CLA content extremely increased by replacement of CLA-vegetable oils and CLA-lard. The level of CLA content in CLA-vegetable oils was higher than CLA-lard. It may be concluded that emulsion-type sausage could be manufactured using CLA-vegetable oils as a pork fat substitutor without any negative effects on general components or physico-chemical properties.

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Expression Study of The Mouse Collectin-Placenta 1 Gene (마우스 Collectin-Placenta 1 유전자의 발현 연구)

  • Kim, Geun Ho;Kim, Youn Uck
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.20 no.8
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    • pp.477-484
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    • 2019
  • Several types of scavenger receptors, including the Collectin-Placenta 1 (CL-P1) receptorthat is present in mammals, are molecules that are expressed on the surfaces of endothelial cells, macrophages and smooth muscle cells. These molecules are cell surface glycoproteins that can be conjugated to oxidized low density lipoprotein (oxLDL). Among these molecules, the effect of quercetin on CL-P1 activation has been confirmed. Quercetin is known as an antioxidant that stops oxidation because it acts to remove free radicals that are responsible for the oxidation reaction. In this study, fragments from the transcription start site of the mouse CL-P1 gene promoter to the -500th base were cloned using DNA polymerase. These fragments were then introduced into macrophage like RAW264.7 cells and fibroblast-like NIH3T3 cells to study the effect of quercetin on the CL-P1 gene expression. As a result, we found that bases ranging from -250 to -350 in the anterior part where gene expression starts are important for producing CL-P1 protein. Among them, the DNA mutation experiments we performed confirmed that the E2F binding sites are critical for producing the CL-P1 protein? In addition, when quercetin was added to the RAW264.7 culture medium, which was a culture of adherent cells, observedthe phenomenon of the cells falling off from the surface of the culture container.

Selective tyrosine conjugation with a newly synthesized PCB -TE2A-luminol bifunctional chelator

  • Subramani Rajkumar;Hyun Park;Abhinav Bhise;Seong Hwan Cho;Jung Young Kim;Kyo Chul Lee;Jeongsoo Yoo
    • Journal of Radiopharmaceuticals and Molecular Probes
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    • v.7 no.2
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    • pp.85-91
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    • 2021
  • Selective amino acid conjugation of bulky antibodies is a valuable asset for real-time diagnosis and therapy. However, selective conjugation incorporating a chelate-bearing radioactive atom into an antibody without affecting its immunoreactivity is a challenging task. A bifunctional chelator (BFC), a selective amino acid-targeting probe, and a linker have been developed to overcome this problem. Here, we report the synthesis of a novel propylene cross-bridged chelator (PCB)-1,8-N,N'-bis-(carboxymethyl)-1,4,8,11-tetraazacyclotetradecane (TE2A)-luminol BFC via a click reaction and radiolabel it with a 64Cu ion for tyrosine-selective conjugation of trastuzumab. In the initial optimization study, we tried different oxidative addition conditions such as electro-oxidation, hemin, horseradish peroxidase, iodogen tube, chloramine-T, and iodo beads. In this study, up to 82% of 64Cu-PCB-TE2A-luminol was conjugated with the antibody in an iodo bead-catalyzed oxidative addition reaction with an isolated yield of 24.4%.