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栝楼籽蛋白分离纯化及抗氧化性的研究 总被引:1,自引:0,他引:1
《应用化工》2016,(1):7-10
采用超声波辅助碱溶法提取栝楼籽蛋白,以等电点沉淀、乙醇沉淀、硫酸铵沉淀等三种方法对栝楼籽蛋白纯化,并对纯化蛋白分别进行羟基自由基清除能力,DPPH自由基清除能力,铁还原能力的测定。结果表明,在三种纯化方法的最优条件下,蛋白质析出率最高的为硫酸铵沉淀法,其次为等电点沉淀法,较小的为乙醇沉淀法;三种方法沉淀蛋白质的抗氧化性均随着蛋白质浓度增大而增强,但它们的抗氧化能力不一,抗氧化能力强弱顺序为:硫酸铵沉淀等电点沉淀乙醇沉淀。 相似文献
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目的优化广西莪术挥发油提取工艺,并分析挥发油的抗氧化活性。方法利用微波辅助提取法提取广西莪术挥发油,通过单因素和正交实验对提取工艺进行优化,再通过测定挥发油的还原性能力以及清除·OH、DPPH·能力,初步评价其抗氧化活性。结果微波辅助提取广西莪术挥发油的最佳提取工艺条件为料液比1∶20,提取时间6 min,提取功率900 W在最佳提取条件下提取率为5.18%。挥发油为100μg/m L时的还原性好于同浓度Vc,并且显示较好的清除羟基自由基和DPPH自由基能力,具有一定抗氧化效果。 相似文献
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为了分离制备猪肺抗氧化肽,该文研究了中心组合设计和响应面分析优化猪肺抗氧化肽的提取工艺,以DPPH自由基清除率为响应值,分析了料液比、水解时间和酶浓度对制备抗氧化肽的影响,再通过葡聚糖凝胶Sephadex G-50、G-25和G-10对抗氧化肽进行分离纯化,得到了具有抗氧化活性的肽段,测定其清除DPPH自由基、超氧阴离子、ABTS自由基、羟基自由基以及金属螯合的能力。猪肺抗氧化肽的最佳提取工艺参数为:新鲜猪肺质量与水质量的比例(料液比)为1∶3,水解6 h,酶浓度为6 500 U/g,此时DPPH自由基清除率为66.89%;抗氧化活性最强的组分A5清除DPPH自由基、超氧阴离子、ABTS自由基和羟基自由基的IC50分别为0.073、0.989、0.192和1.261 g/L,金属螯合能力的IC50为6.505 g/L;其相对分子质量为175。 相似文献
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超声辅助浊点萃取荞麦壳总黄酮工艺及抗氧化活性研究 总被引:1,自引:0,他引:1
以DPPH自由基清除率作为考察指标,采用单因素和正交试验相结合的方法进行了工艺优化,研究超声辅助浊点萃取荞麦壳中黄酮的最佳工艺及抗氧化活性。通过极差分析得出的最佳条件:平衡时间为50 min,液料比为35∶1,离子强度为0.6 mol/L,表面活性剂(TritionX-114)质量浓度为30 g/L。该条件下荞麦壳总黄酮提取率为1.78%。当荞麦壳中黄酮的提取液浓度为40 g/L时,对羟基自由基的清除率为84.77%,对DPPH自由基的清除率为86.36%,对DPPH自由基清除率的IC_(50)值为18.63 g/L,荞麦壳总黄酮提取液具有较强的抗氧化活性。 相似文献
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乙烯酮(双乙烯酮)是十分重要的化工中间体,其下游产品较多。江苏某化工厂开发生产乙烯酮(双乙烯酮)下游产品三十多个,年生产规模三万多吨,是国内以乙烯酮(双乙烯酮)为中间体生产精细化学品的综合骨干企业。针对乙烯酮(双乙烯酮)下游产品废水特点,该厂结合企业实际,开展了产品优化,结构调整,清洁生产,资源循环利用,节水降耗等工作,从源头削减了污染物的生产。同时投资二千多万元新建预处理装置三套,6000m3/d废水生化处理装置一套,使全厂乙烯酮(双乙烯酮)下游产品的废水得到了有效的治理。 相似文献
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D. G. Gordeev L. F. Gudarenko M. V. Zhernokletov V. G. Kudel’kin M. A. Mochalov 《Combustion, Explosion, and Shock Waves》2008,44(2):177-189
A semi-empirical equation of state for metals is described. Its capabilities are demonstrated by the example of the equation
of state for aluminum. New experimental data are presented on the location of the isentrope of aluminum for unloading from
the state at p = 229.71 GPa on the shock adiabat to an aerogel (SiO2) of density 0.08 g/cm3.
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Translated from Fizika Goreniya i Vzryva, Vol. 44, No. 2, pp. 61–75, March–April, 2008. 相似文献
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Jorge Marcelo Romero Soledad Bustillo Hugo Enrique Ramirez Maisuls Nelly Lidia Jorge Manuel Eduardo Gómez Vara Eduardo Alberto Castro Alicia H. Jubert 《International journal of molecular sciences》2007,8(7):688-694
A thermochemical rather simple experimental technique is applied to determine the enthalpy of formation of Diperoxide of ciclohexanone. The study is complemented with suitable theoretical calculations at the semiempirical and ab initio levels. A particular satisfactory agreement between both ways is found for the ab initio calculation at the 6–311G basis This set level. Some possible extensions of the present procedure are pointed out. 相似文献
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A perturbation viscometer is a differential capillary viscometer that measures the logarithmic viscosity gradient of the viscosity-composition curve for gas mixtures. Measurements are made at different gas mixture compositions. Integration of the logarithmic viscosity gradients measured over the full composition range gives the mixture viscosity relative to the viscosity of one of the pure components of the gas mixture. This method is attractive because, for measurements of equal precision, integration of the gradients is potentially an order of magnitude more precise than measurement of the viscosities directly. It can also work at high and low temperatures and perhaps high pressures.The perturbation viscometer has been used to make measurements on ideal gas mixtures at ambient and elevated temperatures. The situation is more complicated when the gas mixtures are non-ideal. Extra effects due to density differences, molar volume change on mixing and differential thermal expansion may be measured in addition to the desired viscosity change producing systematic errors in the results. Thus, a more sophisticated apparatus is required. The standard perturbation viscometer has been modified to separate out the extra effects to permit measurement of the true change in viscosity. In addition, the theoretical operation of the modified apparatus has been revised to account for the design changes to permit calculation of the viscosity-composition profiles from the results.The apparatus has been tested using helium-HFC-125 mixtures and two new viscosity-composition profiles are presented for these mixtures at 23 and . Internal consistency tests have been used to confirm that the data produced are of high quality with an estimated uncertainty in the viscosity ratio data at of 0.9% and at of 1.5%. 相似文献
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醋酸纤维素取代基分布与性质的关系 总被引:9,自引:0,他引:9
分析了以吡啶为溶剂的醋酸纤维素的13C-NMR核磁共振谱,得出了三种不同位置羟基的取代度。结合X—射线和DSC分析,初步说明具有相同取代度但未经水解和经过水解的醋酸纤维素(CA) 性质上的差异是由于三个羟基上的取代度分布不同及消晶程度差异所致。 相似文献