番石榴叶中总黄酮最佳提取条件的探讨及其抑菌作用的研究

设计正交实验,采用超声波法从番石榴叶中提取总黄酮,综合各因素确定最佳提取条件为乙醇浓度40％,固料比（番石榴干叶：浸提剂）=1g：60mL,浸泡25h超声波处理时间50min,获得提取液总黄酮含量为9．9167％。采用牛津杯法做抑菌实验,结果表明番石榴叶和果实的水提、醇提粗提液对大肠杆菌、金黄色葡萄球菌、枯草芽孢杆菌、阴沟肠杆菌、溶血葡萄球菌等均有很好的抑菌效果。叶和果实的总黄酮提取液的抑菌作用也很明显。番石榴有望作为药食同源产品和天然食品防腐剂进行开发利用。     

番石榴叶黄酮类化合物提取及其粗提物对蔬菜病原真菌的抑菌活性

采用溶剂法提取番石榴Psidium guajava叶总黄酮,通过对溶剂浓度、提取温度、时间、料液比等因素进行正交试验,优化番石榴叶总黄酮的最佳提取工艺条件。结果表明,溶剂法提取番石榴叶总黄酮的最佳工艺参数为：80 ℃加热,60%乙醇,料液比1∶15,加热回流提取1 h,在此条件下总黄酮提取率达3.51%。番石榴叶总黄酮粗提物对茄子白绢病菌、甘蓝黑斑病菌、白菜炭疽病菌、黄瓜枯萎病菌的室内抑菌EC50分别为184、209、180、102 mg·mL-1。     

木豆叶总黄酮测定方法的比较研究

采用比色法测定木豆叶中的总黄酮含量。对三氯化铝比色法、硼酸—柠檬酸比色法和硝酸铝比色法3种测定方法进行比较,确定了硝酸铝比色法为木豆叶总黄酮的最佳测定方法,该方法稳定性、精密度和重现性好,其RSD分别为2.1%、0.9%和2.3%,应用该方法测定木豆叶总黄酮含量为15.65 mg·g^-1 DW。本方法适用于木豆叶或其制剂中总黄酮的质量分析检验,为木豆叶中黄酮的研究开发提供了质控依据。     

不同部位艾纳香中总黄酮的含量测定

以芦丁为对照品,建立紫外分光光度法检测艾纳香总黄酮含量的方法,并检测艾纳香中不同部位总黄酮的含量。结果表明:芦丁在0~0.04832mg/mL(r=0.9998)范围内线性关系良好,平均回收率为99·7%,RSD=2.3%,其叶、小枝条、茎含总黄酮分别为2.94%,1.21%,1.36%,该方法简便、可靠、准确,结果可作为艾纳香中总黄酮含量的检测方法。     

大孔吸附树脂分离纯化番石榴叶总黄酮的研究

考察大孔吸附树脂吸附分离番石榴叶总黄酮的工艺条件.以静态饱和吸附量、静态洗脱率、动态饱和吸附量、动态洗脱率为考察指标,比较了D101、AB-8两种大孔树脂分离纯化番石榴叶总黄酮的优劣.又以总黄酮回收率为指标,对最佳树脂吸附工艺参数进行了研究.在考察的2种树脂中,AB-8型树脂最适于番石榴叶总黄酮的分离纯化,其工艺条件为:4倍树脂体积50%乙醇洗脱,速度2mL/min.树脂可重复使用4次.其平均总黄酮回收率为87.47%.所得总黄酮纯度为74.03%     

阔叶十大功劳叶与花总黄酮提取及含量测定

目的:研究阔叶十大功劳叶与花总黄酮的提取方法和含量测定。方法:比较以索氏提取法、超声波提取法和微波辅助提取法3种方法提取阔叶十大功劳叶与花中总黄酮,用亚硝酸钠-硝酸铝-氢氧化钠比色法测定总黄酮含量。结果:3种提取方法中,微波法提取效率最高,结果重现性好,并测得叶与花中总黄酮含量分别为2.182%和8.155%。结论:阔叶十大功劳总黄酮含量较高,总黄酮在花中的含量明显高于叶。     

沙棘不同部位总黄酮含量的测定及比较

考察了引种于俄罗斯的大果沙棘不同部位总黄酮含量的差异。用超声提取作为沙棘总黄酮的制备方法;以芦丁为对照品,采用分光光度法作为沙棘总黄酮的测定方法。实验结果表明,沙棘叶、果肉和果皮中总黄酮含量分别为1.71%、0.76%和0.55%,叶中总黄酮含量分别是果肉和果皮的2.3倍和3.1倍,因此引种于俄罗斯的大果沙棘叶具有较大的开发价值和应用前景。     

北山楂叶与云南山楂叶中总黄酮与金丝桃苷含量的比较

目的:比较北山楂叶和云南山楂叶中总黄酮和金丝桃苷的含量.方法:以芦丁为对照品,采用紫外-可见分光光度法在500nm波长处测定总黄酮的含量;以金丝桃苷为对照品,采用高效液相色谱法,用C18色谱柱,以乙腈-甲醇-四氢呋喃-0.5%冰醋酸溶液(1:1:19.4:64.2)为流动相,检测波长为363nm,测定金丝桃苷的含量.结果:北山楂叶和云南山楂叶中总黄酮及金丝桃苷的含量分别为7.70%和6.79%,0.143%和0.289%.结论:北山楂叶中总黄酮的含量高于云南山楂叶,而金丝桃苷的含量则刚好相反.     

黑龙江省西部乌拉尔甘草总黄酮含量的动态变化研究

采用超声提取和分光光度法对黑龙江省西部地区乌拉尔甘草不同部位的总黄酮含量进行测定,并对其季节变化进行了分析,研究结果表明:采用50%甲醇溶液提取,超声45 min对甘草总黄酮提取效果较好,适于进行大批量样品的提取测定.无论是野生甘草还是栽培甘草,在一个生长季中,叶的总黄酮含量最高,而地下部分含量则相对较低.在5～10月期间,叶的总黄酮含量逐渐下降,而地下部分总黄酮含量如根和根茎具有上升的趋势.甘草各部位总黄酮含量在不同生长季存在波动现象,尤其在具有运输功能的部位如复叶柄、地上茎表现更为明显.野生甘草不同部位的总黄酮含量的波动可能与有性繁殖有关,而栽培甘草的总黄酮含量的波动可能与无性生殖有关.     

蜜楝叶、花及果实中总黄酮含量积累动态研究

本文采用紫外分光光度法分析检测了不同生长时期蜜楝叶、花及果实中总黄酮的含量及其积累动态。芦丁标准品在7.76~77.60μg/m L范围内呈良好的线性关系,Y=0.0087X+0.0268(R2=0.9964),平均加样回收率为101.72%,RSD为2.25%(n=6)。随着植物发育阶段的推移,蜜楝叶、花、果实中总黄酮的含量逐渐增加,其中花蕾和幼果中总黄酮含量最高。研究结果表明蜜楝花及果实中黄酮类化合物含量丰富,可作为提取制备黄酮类化合物的一种植物资源,具有很好的开发利用价值。     

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