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1.
M.?NaczkEmail author R.?B.?Pegg R.?Zadernowski F.?Shahidi 《Journal of the American Oil Chemists' Society》2005,82(4):255-260
Possible use of canola hulls as a source of natural anti-oxidants was explored. Cyclone canola hulls were extracted with methanol
(30 to 80%, vol/vol) and acetone (30 to 80%, vol/vol). The free radical-scavenging activity of phenolic extracts so prepared
was evaluated using the 2,2′-azinobis-(3-ethylbenzothiazoline-6-sulfonate) (ABTS) radical ion (ABTSo−), 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical, and chemiluminescence assays. The total content of phenolics in prepared
extracts from canola hulls ranged from 15 to 136 mg sinapic acid equivalents per gram of extract. Higher levels of condensed
tannins were detected in the acetone extracts than in the corresponding methanolic counterparts. Seventy and 80% (vol/vol)
acetone extracts displayed markedly stronger antioxidant activity than any of the other extracts investigated. Statistically
significant linear correlations were found between TEAC (Trolox equivalent antioxidant capacity) values (expressed in mM of
Trolox equivalents per gram of extract) and total pehnolics, TEAC and total condensed tannins (i.e., determined using the
modified vanillin and pronthocyanidin assays), as well as TEAC and protein precipitation activity of phenolic extracts (i.e.,
measured using the dye-labeled assay). The antioxidant activities of extracts as determined by the ABTSo− radical ion assay correlated highly with those of the chemiluminescence and DPPH radical assays. 相似文献
2.
药物抗氧化作用对DNA发光动力学行为的影响 总被引:14,自引:0,他引:14
本文应用CuSO4-Phen-Vc-H2O2-DNA化学发光体系观察药物对发光动力学行为的影响,研究了九种药物对DNA损伤的保护作用,并对其药物结构对抗氧化能力的影响进行了分析。发现药物在该系统中的抗氧化作用有三种类型,提示它们可能在体内不同的反应过程中起不同的作用。在该系统中具有抑制DNA损伤发光能力的药物,按其作用强弱依次为阿魏酸、丹参素、芦丁,茶多酚、SOD、、丹参酮Ⅱ-A,丹皮酚,五味子乙 相似文献
3.
以双(2,4,5-三氯-6-正丁烷氧羰基苯基)草酸酯(简称CPPO)和红色荧光剂罗丹明B组成的过氧草酸酯类化学发光体系为研究对象,从粒径、用量和种类的角度讨论了分散剂云母等对体系发光效率的影响.结果表明,添加30μm云母50mg后,体系的发光寿命、强度均显著增加,发光效率较高。 相似文献
4.
化学发光材料双(2,4,6-三氯苯基)草酸酯的合成 总被引:1,自引:0,他引:1
草酸酯是过氧草酸酯类化学发光所必需的一种要素化合物,作者合成了一种能提供高强度化学发光的草酸酯即双(2,4,6 三氯苯基)草酸酯,并以质谱验证了结构。 相似文献
5.
分别考察了钌(Ⅱ)-Ⅲ(1,10-菲咯啉)和硫脲在KMnO4、KBrO3、K2S2O8、I2、KIO4、 Ce(SO4)2存在下的化学发光反应情况,发现只有KMnO4能氧化硫脲和钌(Ⅱ)-Ⅲ(1,10-菲咯啉) 而发光。体系的化学发光强度与硫脲的浓度在2.0×10~(-8)~1.0×10~(-5)mol·L~(-1)范围内呈线性关系,方法的检出限为2.0×10~(-8)mol·L~(-1),平行测定10次相对标准偏差为1.1%。该法用于分析测定白葡萄酒中的硫脲,平均回收率为96.3%~103%获得满意结果。 相似文献
6.
Elena Mikhalchik Liliya Yu. Basyreva Sergey A. Gusev Oleg M. Panasenko Dmitry V. Klinov Nikolay A. Barinov Olga V. Morozova Alexander P. Moscalets Liliya N. Maltseva Lyubov Yu. Filatova Evgeniy A. Pronkin Julia A. Bespyatykh Nadezhda G. Balabushevich 《International journal of molecular sciences》2022,23(18)
Nano- and microparticles enter the body through the respiratory airways and the digestive system, or form as biominerals in the gall bladder, salivary glands, urinary bladder, kidney, or diabetic pancreas. Calcium, magnesium, and phosphate ions can precipitate from biological fluids in the presence of mucin as hybrid nanoparticles. Calcium carbonate nanocrystallites also trap mucin and are assembled into hybrid microparticles. Both mucin and calcium carbonate polymorphs (calcite, aragonite, and vaterite) are known to be components of such biominerals as gallstones which provoke inflammatory reactions. Our study was aimed at evaluation of neutrophil activation by hybrid vaterite–mucin microparticles (CCM). Vaterite microparticles (CC) and CCM were prepared under standard conditions. The diameter of CC and CCM was 3.3 ± 0.8 µm and 5.8 ± 0.7 µm, with ƺ-potentials of −1 ± 1 mV and −7 ± 1 mV, respectively. CC microparticles injured less than 2% of erythrocytes in 2 h at 1.5 mg mL−1, and no hemolysis was detected with CCM; this let us exclude direct damage of cellular membranes by microparticles. Activation of neutrophils was analyzed by luminol- and lucigenin-dependent chemiluminescence (Lum-CL and Luc-CL), by cytokine gene expression (IL-6, IL-8, IL-10) and release (IL-1β, IL-6, IL-8, IL-10, TNF-α), and by light microscopy of stained smears. There was a 10-fold and higher increase in the amplitude of Lum-CL and Luc-CL after stimulation of neutrophils with CCM relative to CC. Adsorption of mucin onto prefabricated CC microparticles also contributed to activation of neutrophil CL, unlike mucin adsorption onto yeast cell walls (zymosan); adsorbed mucin partially suppressed zymosan-stimulated production of oxidants by neutrophils. Preliminary treatment of CCM with 0.1–10 mM NaOCl decreased subsequent activation of Lum-CL and Luc-CL of neutrophils depending on the used NaOCl concentration, presumably because of the surface mucin oxidation. Based on the results of ELISA, incubation of neutrophils with CCM downregulated IL-6 production but upregulated that of IL-8. IL-6 and IL-8 gene expression in neutrophils was not affected by CC or CCM according to RT2-PCR data, which means that post-translational regulation was involved. Light microscopy revealed adhesion of CC and CCM microparticles onto the neutrophils; CCM increased neutrophil aggregation with a tendency to form neutrophil extracellular traps (NETs). We came to the conclusion that the main features of neutrophil reaction to mucin–vaterite hybrid microparticles are increased oxidant production, cell aggregation, and NET-like structure formation, but without significant cytokine release (except for IL-8). This effect of mucin is not anion-specific since particles of powdered kidney stone (mainly calcium oxalate) in the present study or calcium phosphate nanowires in our previous report also activated Lum-CL and Luc-CL response of neutrophils after mucin sorption. 相似文献
7.
8.
目的:探讨咖啡酸衍生物(CADs):绿原酸(Chlorogenic acid,ChA)、阿魏酸(Ferulic acid,FeA)、迷迭香酸(Rosmarinic acid,RoA)对自由基致DNA损伤的联合抑制保护效果。方法:运用DPPH自由基及羟自由基反应模型观察不同组成的CADs对自由基的淬灭效应,以CuSO4-Phen-VitC-H2O2-DNA化学发光体系测定不同成分的多酚类物质对·OH致DNA损伤的抑制作用。结果:在30min时间内,三种CADs联合组在浓度为25、50、100、200μg/mL时,对DPPH·清除率分别为28.93%、58.39%、83.93%和84.09%;对·OH清除率分别为33.43%、55.27%、71.23%、77.49%。在DNA化学发光体系中,在25~200μg/mL范围内,三种CADs联合组对DNA损伤产物发光抑制率为12.49%~81.09%。结论:CADs能有效清除DPPH自由基和羟自由基,抑制羟自由基引发的DNA损伤程度,并延迟其受损伤的时间。在各实验组中三种CADs联用组在对DPPH自由基清除率、DNA损伤产物发光抑制率以及保护DNA损伤的能力均最强,体现出协同作用。 相似文献
9.
10.
在酸性介质中,高锰酸钾能氧化穿心莲内酯发生化学发光反应,而甲醛的存在可使发光强度增强,在体系中加入表面活性剂十六烷基三甲基溴化铵可以进一步增强该体系的化学发光强度。据此建立了1种流动注射化学发光测定穿心莲内酯的新方法。方法的线性范围为5.0×10-6~2.5×10-4g.mL-1,检测限1.0×10-6g.mL-1,相对标准偏差0.9%(n=12,c=1.0×10-5g.mL-1)。样品测量通量150 h-1。该法用于药物中穿心莲内酯含量的测定,结果令人满意。同时,对高锰酸钾-甲醛-穿心莲内酯体系化学发光反应机理进行了探讨。为穿心莲内酯的快速定量测定提供了1种简便、高效的方法。 相似文献