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探讨猕猴桃根提取物的体外抗氧化作用.采用DPPH自由基、超氧阴离子、羟基自由基、过氧化氢和还原力的反应体系,测定猕猴桃根提取物的体外抗氧化作用,并用VC进行对照实验.实验条件下,ERHM对DPPH自由基、超氧阴离子(·O2-)、羟基自由基(·OH)、过氧化氢H2O2等均有较强的清除或抑制作用,且显示较好的量效关系,同时具有一定的还原力.其消除DPPH自由基的EC50为8.03 μg/mL,清除超氧阴离子(·O2-)的EC5o为1.28 mg/mL,抑制羟基自由基(·OH)能力可达69.4%,浓度为100 μg/mL时对过氧化氢(H2O2)的清除率为42%.猕猴桃根提取物具有较强的还原力,能有效清除DPPH和超氧阴离子自由基,并抑制羟基自由基的产生.所以,ERHM有效成分具有较为显著的抗氧化作用. 相似文献
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猪血多肽亚铁螯合盐的体外抗氧化作用研究 总被引:1,自引:0,他引:1
研究了猪血多肽亚铁螯合盐对超氧阴离子自由基(O2-·)和过氧化氢(H2O2)的清除作用,并比较了维生素C、猪血多肽亚铁和猪血多肽对二者的清除能力。实验结果表明:猪血多肽亚铁螯合盐能清除超氧阴离子自由基(O2-·)和过氧化氢(H2O2),维生素C、猪血多肽亚铁和猪血多肽这三种物质对超氧阴离子自由基(O2-·)和过氧化氢(H2O2)清除能力的强弱顺序为维生素C〉猪血多肽亚铁〉猪血多肽,故猪血多肽亚铁螯合盐具有较强的清除超氧阴离子自由基(O2-·)和过氧化氢(H2O2)的能力。 相似文献
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海参脏器多糖体外抗氧化活性研究 总被引:3,自引:0,他引:3
研究海参脏器多糖HPS1、HPS2在体外对羟自由基(·OH)、超氧阴离子(O2-·)、以及1,1-二苯基苦基苯肼(DPPH·)自由基的清除能力.结果表明,HPS1、HPS2对·OH、O2-·和DPPH·自由基均有一定清除作用,且随着多糖质量浓度的增大,其抗氧化活性逐渐增加.HPS1对·OH、O2-·和DPPH.自由基清除能力IC50分别为0.89、0.98、0.31mg/mL;HPS2对·OH、O2-·和DPPH·自由基清除能力IC50分别为0.64、0.78、0.24mg/mL.2种多糖对DPPH.自由基的清除活性尤其明显.HPS2对于3种自由基的抗氧化活性均强于HPS1. 相似文献
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以猕猴桃籽油为原料,采用体外抗氧化实验模型研究其抗氧化活性。通过测定猕猴桃籽油还原力和DPPH自由基、超氧阴离子自由基(O2-·)、H2O2以及羟自由基(·OH)清除实验,以VC为阳性对照,探讨猕猴桃籽油的抗氧化性能。结果表明:猕猴桃籽油的还原能力随其质量浓度的增加而增强,对DPPH自由基、O2-·、H2O2以及·OH的清除率随质量浓度的增加而升高,其中对O2-·的清除效果比VC更明显,对其他自由基的清除效果却比VC弱;猕猴桃籽油对O2-·、H2O2、·OH的IC50分别为0.078、0.1、0.2mg/mL,表明猕猴桃籽油清除O2-·的效果最好。 相似文献
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采用丙酮温浸法对尖果沙枣和大果沙枣果、叶中多酚物质进行提取并研究其抗氧化活性。通过测定不同材料多酚提取物对羟自由基(·OH)、超氧阴离子自由基(O2-·)以及2,2二苯代苦味肼基(DPPH·)的清除率,并利用硫代巴比妥酸法(TBA法)测定其对脂质过氧化的抑制作用。结果表明:八种实验材料中,尖果沙枣青果和嫩叶多酚提取物对·OH、O2-·、DPPH·均具有较好的清除作用,且清除率均高于50%,同时对脂质过氧化的抑制作用明显高于其余实验材料。尖果沙枣较大果沙枣具有更好的体外抗氧化活性。 相似文献
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三叉苦提取物抗氧化作用的研究 总被引:6,自引:0,他引:6
目的:研究三叉苦不同部位水提取物的抗氧化作用及其规律,为食品或药物抗氧化剂的筛选和应用提供理论依据。方法:应用化学发光法检测三叉苦的各部位水提取物对邻苯三酚 -CTMAB 体系产生的超氧阴离子自由基(O2·)、邻菲罗啉 - 抗坏血酸体系产生的羟自由基(·OH)及过氧化氢(H2O2)的清除作用。结果:三叉苦水提取物具有明显的清除超氧阴离子自由基、羟自由基和过氧化氢的作用,清除率与浓度之间存在着明显的量效关系。结论:证明了三叉苦各部位的水提取物均是一种有效的抗氧化剂。 相似文献
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D. C. J. Gardner G. C. Tomlin T. Cele G. A. Hamilton C. M. James L. I. Stateva S. G. Oliver 《Yeast (Chichester, England)》1996,12(4):411-413
A physical map of a 14·5 kb region close to the centromere on the left arm of chromosome IV of Saccharomyces cerevisiae is presented. This map has been constructed by restriction analysis of a clone from a YCp50 genomic library and by use of pre-existing and new sequence data from this region. The map reveals the following gene order (reading from the most centromere-distal to the most centromere-proximal locus): USO1/INT1–MBP1–PSA1–SLC1–YLA1 and defines the size of the open reading frames and intergenic regions. 相似文献
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E Barbeau S
S Schwarzlaff M
G Uriyo J
M Johnson C
H Harris C
A Griffey 《Journal of the science of food and agriculture》2003,83(1):29-38
When translocated into wheat, the short arm of the 1R chromosome of rye carries with it linked resistance genes to powdery mildew, stripe rust, leaf rust and stem rust. The translocation is also reported to increase yield potential of hard wheats. However, many doughs made from some 1BL/1RS hard wheats are unacceptable for breadmaking purposes because of excessive stickiness and mixing intolerance. 1BL/1RS wheats may be sticky because of: the inheritance of secalin proteins from rye and absence of key glutenin subunits; higher amounts and/or differences in the composition of cell wall polysaccharides, β‐glucans and pentosans; and/or the presence of a ferulic acid ester moiety residing with the water‐soluble fraction of 1BL/1RS flours. None of these hypotheses has been proven or disproven, to date, as a cause of excessive stickiness. Investigators have found that 1BL/1RS doughs are not uniformly sticky and are in some instances less sticky than non‐1BL/1RS doughs. Significant genotype–environment interactions have been reported for dough stickiness and flour quality characteristics of 1BL/1RS wheats. Investigators have generally failed to find significant differences in the breadmaking performance of 1BL/1RS and non‐1BL/1RS hard wheats despite a report that 1BL/1RS doughs break down and soften during high‐speed mixing. The 1BL/1RS translocation has been shown to reduce cookie spread of soft wheat flours but has no deleterious effects on cake volume or texture. © 2002 Society of Chemical Industry 相似文献
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为了研究环丙烯类乙烯抑制剂的作用效果,以绿熟期番茄为试材,用1-甲基环丙烯(1-MCP)、1-戊基环丙烯(1-PentCP)、1-辛基环丙烯(1-OCP)处理后,常温(18℃±2℃)贮藏,每隔3 d测定1次理化指标,研究三者对番茄果实后熟衰老和贮藏效果的影响。结果表明:1-MCP及其结构相似物处理番茄不同程度地降低了呼吸强度和乙烯释放量的峰值,抑制了番茄果实硬度的下降,延缓了可溶性固形物含量的上升,同时也有效抑制了后熟期番茄果实过氧化氢酶(CAT)活性、过氧化物酶(POD)活性,延缓了果实的后熟衰老。3种试验的抑制剂中,1-MCP、1-PentCP和1-OCP处理随支链长度的增加,抑制后熟衰老的效果依次降低。 相似文献
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RL95-2 endometrial cancer cells were used to study cytochrome P450-mediated chemopreventative mechanisms of four flavonoids found in foods. To investigate enzymatic CYP1 inhibition, intact cells were induced with benzo(a)pyrene or 2,3,7,8-tetrachlorodibenzo-p-dioxin. Quercetin, kaempferol and myricetin inhibited CYP1 activity dose-dependently with IC50s ranging from 2.2 to 4 μM; while amentoflavone was inactive. Further experiments were designed to determine if flavonoids also interacted with the AhR or caused a decrease in CYP1 protein or mRNA expression. CYP1A1 protein expression was inhibited in cells co-treated with TCDD and quercetin, kaempferol or myricetin compared with TCDD alone, but amentoflavone was ineffective. Relatively higher (∼7-fold) basal levels of CYP1B1 protein were not significantly affected by flavonoid treatments. In general, at the message level significant inhibition of induced CYP1A1 or CYP1B1 was not detected following flavonoid cotreatment. Despite the common inhibitory effects of quercetin, kaempferol, and myricetin on induced CYP1A1-dependent activity and protein expression, the mechanisms of CYP1 inhibition in this cell line are complex and dependent on the CYP gene, AhR inducer and the flavonoid. 相似文献
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用清除DPPH自由基法评价药黑豆色素的抗氧化能力 总被引:2,自引:2,他引:0
通过对DPPH·体系的吸收光谱和稳定性研究,确定DPPH·乙醇溶液的检测波长为517nm;体系中加入不同抗氧化剂反应30min趋于稳定;用上述方法评价纯化前后的药黑豆色素(MBSP1和MBSP2)对DPPH·清除率和浓度之间的关系,以Vc作对照,HSC50值作为评价指标,并对MBSP2进行抗氧化动力学分析和FT-IR分析.结果表明,药黑豆色素对DPPH·具有明显的清除作用,Vc、MBSP1和MBSP2三者的HSC50值分别为0.63、1.09、0.88mg/mL,同时药黑豆色素的抗氧化能力与其花色苷含量呈正相关.FT-IR结果表明,药黑豆色素是一种以矢车菊素为主要结构的花色苷类化合物. 相似文献
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研究了不同浓度(1、5和50μl/L)的环丙烯类乙烯效应抑制剂1-MCP(1-甲基环丙烯)和1-OCP(1-辛基环丙烯)常温[(20±2)℃]熏蒸处理20h对青熟期芒果(Mangifera indica L.)后熟和衰老的影响。结果表明:不同浓度的环丙烯类乙烯效应抑制剂均能不同程度地延缓芒果果实可滴定酸、MDA(丙二醛)含量的下降;降低POD(过氧化物酶)、PPO(多酚氧化酶)活性;抑制硬度的下降和SSC(可溶性固形物)含量的上升;减缓果实质量损失和成熟度的进程;呼吸高峰出现的时间与对照相比延迟了3 d。表明1-MCP和1-OCP处理能有效地延缓芒果果实的后熟和衰老,其中以5μl/L 1-MCP和50μl/L 1-OCP的效果较佳。 相似文献