当归不同提取液中阿魏酸、咖啡酸含量及抗氧化作用的比较研究北大核心CSCD

为考察不同提取条件对当归提取液中阿魏酸和咖啡酸的含量及抗氧化作用的影响,本研究通过HPLC外标一点法检测当归提取液中阿魏酸和咖啡酸的含量,通过DPPH法和ABTS法检测当归提取液的抗氧化作用。研究结果表明,不同提取条件下当归提取液中阿魏酸的含量为0. 574～0. 707 mg/g,咖啡酸为0. 012～0. 082 mg/g;碱水溶液提取时阿魏酸与咖啡酸的含量最高,其抗氧化活性也最强,而95%乙醇提取时的含量最低,抗氧化活性最弱;提取溶剂随醇浓度的增加,咖啡酸的含量逐渐减少,阿魏酸的含量呈现先增加后减少的趋势,30%～50%乙醇提取时各组分有良好的协同抗氧化作用。     

当归不同提取液中阿魏酸、咖啡酸含量及抗氧化作用的比较研究

为考察不同提取条件对当归提取液中阿魏酸和咖啡酸的含量及抗氧化作用的影响,本研究通过HPLC外标一点法检测当归提取液中阿魏酸和咖啡酸的含量,通过DPPH法和ABTS法检测当归提取液的抗氧化作用。研究结果表明,不同提取条件下当归提取液中阿魏酸的含量为0. 574～0. 707 mg/g,咖啡酸为0. 012～0. 082 mg/g;碱水溶液提取时阿魏酸与咖啡酸的含量最高,其抗氧化活性也最强,而95%乙醇提取时的含量最低,抗氧化活性最弱;提取溶剂随醇浓度的增加,咖啡酸的含量逐渐减少,阿魏酸的含量呈现先增加后减少的趋势,30%～50%乙醇提取时各组分有良好的协同抗氧化作用。     

响应面法优化当归中阿魏酸和藁本内酯提取工艺研究

为优化中药材当归中主要活性成分阿魏酸和藁本内酯同时提取的最佳工艺条件,该文以超声波辅助响应面优化当归中阿魏酸和藁本内酯提取工艺,采用氢核磁共振定量方法同时测定当归中阿魏酸和藁本内酯的含量.优化工艺以阿魏酸和藁本内酯含量的综合评分为考察指标,选取乙醇浓度、提取时间、液料比三个主要因素,采用单因素筛选结合Box-Behnk...     

黄芪多糖的闪式提取技术研究

目的:建立黄芪多糖的闪式提取技术.方法:对黄芪多糖闪式提取技术中提取温度、提取时间、提取电机电压、pH值、料液比、乙醇浓度进行了单因素实验,以多糖得率为指标确定提取工艺,并与传统碱水提取法进行了比较,最后用该工艺对8种不同产地或级别的黄芪原料进行多糖提取和含量测定.结果:初步确定提取工艺为温度65℃、提取时间2 min、pH值为10、提取电机电压200V、料液比1:10、乙醇浓度为5%(V/V),提取所得黄芪多糖总量达到123.46mg/g,比碱提法多糖得率提高了近30%,该法检测不同黄芪原料多糖含量在87.44～187.74mg/g.结论:闪式提取技术能大大提高黄芪多糖提取率,不同产地或级别的黄芪原料在黄芪多糖含量上有较大差异.     

近红外漫反射光谱法快速测定当归中阿魏酸及亚油酸北大核心CSCD

以反相高效液相色谱法(RP-HPLC)测定的当归中阿魏酸及亚油酸含量作为参考值,利用TQ Analyst 8.0软件的偏最小二乘法(PLS)建立了快速、准确测定当归中阿魏酸及亚油酸含量的定量模型。结果表明,阿魏酸校正集的相关系数(R)为0.9721,校正均方差(RMSEC)为0.5942,预测均方差(RMSEP)为0.6747。亚油酸校正集的相关系数为0.9673,校正均方差为0.4573,预测均方差为1.0682。验证集中阿魏酸及亚油酸的平均预测回收率分别为101.98%和102.03%。该方法操作简单、快速,所建模型预测结果准确、可靠,可用于中药当归中阿魏酸及亚油酸的含量测定。     

近红外漫反射光谱法快速测定当归中阿魏酸及亚油酸

以反相高效液相色谱法(RP-HPLC)测定的当归中阿魏酸及亚油酸含量作为参考值,利用TQ Analyst 8.0软件的偏最小二乘法(PLS)建立了快速、准确测定当归中阿魏酸及亚油酸含量的定量模型。结果表明,阿魏酸校正集的相关系数(R)为0.9721,校正均方差(RMSEC)为0.5942,预测均方差(RMSEP)为0.6747。亚油酸校正集的相关系数为0.9673,校正均方差为0.4573,预测均方差为1.0682。验证集中阿魏酸及亚油酸的平均预测回收率分别为101.98%和102.03%。该方法操作简单、快速,所建模型预测结果准确、可靠,可用于中药当归中阿魏酸及亚油酸的含量测定。     

响应面分析法优化当归粗多糖提取工艺

选取岷县当归药材为原料,采用水提醇沉法进行多糖提取,以当归粗多糖得率为指标,探讨加水量、回流提取时间、水提液的浓缩比、醇沉后所达含醇比例对当归多糖得率的影响。在单因素分析的基础上,采用响应面分析法(RSM)确定了当归粗多糖最佳提取条件为:加水量837.6 mL/100 g,浓缩后溶液体积为228.12 mL,最终含乙醇浓度为65.80%,回流提取时间2 h,在此条件下预测当归粗多糖得率理论的最佳值为10.44%,实际验证值为10.40%,两者相符,说明RSM法分析的可靠性。     

不同提取方法对豫产白花蛇舌草多糖及抗氧化活性的影响

为评价不同提取方法对河南地区白花蛇舌草粗多糖的得率、总碳水化合物含量、杂质含量和抗氧化活性的影响,本实验分别以传统热水提取法、超声波辅助提取法、纤维素酶提取法从该药材中提取多糖。同时测定了粗多糖中总碳水化合物含量、杂质含量(总蛋白和总酚含量)以及羟基自由基清除能力、DPPH自由基清能力、还原力等抗氧化能力。实验结果显示三种提取法所得粗多糖相对于原药材的得率分别为6.77±0.09%、6.37±0.01%和4.81±0.90%;粗多糖中的总碳水化合物含量分别为289.14±1.33、246.83±2.33和278.92±2.92mg/g。粗多糖中总蛋白含量分别为28.59±2.21、23.26±2.43和4.96±0.18mg/g,总酚类成分含量分别为5.9±0.08、5.31±0.40和2.82±0.07mg/g。抗氧化活性实验结果表明,三种粗多糖的羟基自由基清除能力呈现出浓度依赖性,且均在3.0mg/mL时达到最大,对应最大清除率分别为89.13%、85.87%和74.71%。另外,三种粗多糖的DPPH自由基清除率分别在0.75~3.0mg/mL的浓度区间内达到最大并保持稳定,对应清除率的稳定区间分别为77.02%~77.90%、77.06%~77.96%和83.16%~85.73%。综上所述,以上三种不同提取方法对白花蛇舌草多糖的品质影响较大,可以为豫产白花蛇舌草的品质鉴别、多糖质量控制和开发利用提供依据。     

樱桃核的主要成分及水溶性多糖的体外抗氧化测定

樱桃加工过程产生的大量加工副产物——樱桃核会被丢弃。对樱桃核主要成分的含量进行了测定。采用水溶醇沉方法从樱桃核中提取水溶性多糖,并进行了体外抗氧化功效评价。实验测得樱桃核中主要成分含量(干重)依次为:蛋白质含量18.80±0.30 g/100 g,脂质含量8.97±0.58 g/100 g,可溶性总糖含量4.96±0.14 g/100 g,灰分含量1.49±0.08 g/100 g,维生素C(Vc)含量27.55±0.99 mg/100 g。樱桃核水溶性多糖对1,1-二苯基-2-三硝基苯肼(DPPH)、2,2'-联氮-双-3-乙基苯并噻唑啉-6-磺酸(ABTS)、羟基自由基的体外清除能力非常稳定,IC_(50)分别为0.31、0.32和0.34 mg/mL。樱桃核具有一定的营养价值和抗氧化功效,为樱桃核的"变废为宝"开发利用提供理论参考。     

HPLC法测定新疆阿魏不同部位阿魏酸的含量

建立新疆阿魏中不同部位阿魏酸的高效液相色谱含量测定方法.采用PLATISIL ODS(250 mm×4.6mm,5μm)色谱柱,甲醇～0.1％冰醋酸水溶液(35∶ 65)为流动相,流速1.0 mL/min,检测波长320 nm,柱温30℃.测得阿魏酸进样量在0.440～5.396μg/mL(r=0.9997)范围内与峰面积有良好的线性关系,平均回收率达97.8％,RSD为1.79％(n=9).新疆阿魏胶、根、茎和叶中的阿魏酸含量分别为0.2600、0.0362、0.0225和0.0275 mg/g,胶中阿魏酸的含量远高于根、茎和叶.该方法简便、准确、重复性好,可用于新疆阿魏中不同部位阿魏酸含量的测定.     

Investigation of the mechanism of temperature sensitivity of the electroreceptors of ampullae of lorenzini

In experiments on Black Sea skates (Raja clavata), the potential of the receptor epithelium of the ampullae of Lorenzini and spike activity of single nerve fibers connected to them were investigated during electrical and temperature stimulation. Usually the potential within the canal was between 0 and –2 mV, and the input resistance of the ampulla 250–400 k. Heating of the region of the receptor epithelium was accompanied by a negative wave of potential, an increase in input resistance, and inhibition of spike activity. With worsening of the animal's condition the transepithelial potential became positive (up to +10 mV) but the input resistance of the ampulla during stimulation with a positive current was nonlinear in some cases: a regenerative spike of positive polarity appeared in the channel. During heating, the spike response was sometimes reversed in sign. It is suggested that fluctuations of the transepithelial potential and spike responses to temperature stimulation reflect changes in the potential difference on the basal membrane of the receptor cells, which is described by a relationship of the Nernst's or Goldman's equation type.I. P. Pavlov Institute of Physiology, Academy of Sciences of the USSR, Leningrad. I. M. Sechenov, Institute of Evolutionary Physiology and Biochemistry, Academy of Sciences of the USSR, Leningrad. Pacific Institute of Oceanology, Far Eastern Scientific Center, Academy of Sciences of the USSR, Vladivostok. Translated from Neirofiziologiya, Vol. 12, No. 1, pp. 67–74, January–February, 1980.     

Principles of organization and evolution of systems of regulation of functions

Evolution of living organisms is closely connected with evolution of structure of the system of regulations and its mechanisms. The functional ground of regulations is chemical signalization. As early as in unicellular organisms there is a set of signal mechanisms providing their life activity and orientation in space and time. Subsequent evolution of ways of chemical signalization followed the way of development of delivery pathways of chemical signal and development of mechanisms of its regulation. The mechanism of chemical regulation of the signal interaction is discussed by the example of the specialized system of transduction of signal from neuron to neuron, of effect of hormone on the epithelial cell and modulation of this effect. These mechanisms are considered as the most important ways of the fine and precise adaptation of chemical signalization underlying functioning of physiological systems and organs of the living organism