响应面优化超声辅助提取刺梨多糖工艺研究

探讨超声波作用下刺梨多糖提取的最佳工艺条件。在单因素试验基础上,采用响应面法对刺梨多糖提取工艺参数进行优化研究。响应面试验表明提取温度、超声功率、超声时间、液料比对响应值刺梨多糖提取率均有显著影响,优化得到超声辅助提取刺梨多糖最佳工艺条件为:超声时间30 min,超声功率120 W,液料比40m L/g,提取温度80℃,提取3次。在此条件下的刺梨多糖提取率可达2.18%,与模型预测值非常接近。     

响应面法优化金刷把多糖提取工艺

利用响应面法优化金刷把多糖的提取工艺。在单因素试验的基础上,选择提取温度、提取时间、料液比为自变量,以多糖提取率为响应值,进行Box-Benhnken中心组合实验设计,应用响应曲面分析方法优化提取条件,得到金刷把多糖最佳提取工艺条件如下:提取温度95℃,提取时间2.5 h,料液比1∶20 g/m L,此时金刷把多糖提取率的理论预测值为4.62%,最优条件下多糖得率的实验值为4.42%,与理论值的相对误差为4.3%。经过响应面法优化提取工艺,提高了提取率,适用于金刷把粗多糖的提取。     

响应面法优化龙牙百合多糖的高温高压水提取法工艺

以江西万载龙牙百合为原料,研究了料液比、提取温度、提取时间和提取次数4个因素对百合多糖得率的影响,在单因素试验基础上,采用Box-Behnken响应面法设计优化提取工艺。结果表明:最佳提取条件为料液比1∶25(g/mL)、温度121℃、时间92 min,提取次数2次,在此条件下百合多糖的得率为6. 284%。该方法简单、易操作,比较适于百合多糖的提取。     

响应面法优化桑葚多糖的超声波辅助提取工艺条件

本研究利用响应面法优化桑葚多糖的超声波辅助提取工艺条件;选定提取温度、时间及水料比作为影响因素,以桑葚多糖提取率为评价指标,在单因素实验的基础上,通过3因素3水平Box-Behnken中心组合试验建立多糖提取率的二次多项式回归方程,研究超声提取时间、温度、水料比对桑葚多糖提取率的影响;结果显示最佳提取工艺条件为提取温度72℃、超声时间23.5 min、水料比27∶1(v∶m,mL/g),在该条件下多糖提取率预测值为17.80%,验证值为17.78±0.85%(n=3);此方法与传统水提取法相比具有省时、高效的优点,为桑葚多糖的后续研发提供实验基础。     

响应面优化绿穗苋多糖的提取工艺

本研究旨在对热水工艺提取绿穗苋多糖的条件进行优化。在单因素实验基础上,筛选得到三个主要对绿穗苋多糖提取率相关的因素,其分别为:提取料液比、提取时间和提取温度。采用响应面试验设计软件,以提取料液比、提取时间和提取温度3因素作为试验的自变量,绿穗苋多糖提取率作为因变量,运用Box-Behnken实验设计和响应面分析法,得到了热水提取绿穗苋多糖工艺的最佳条件:料液比1:42.08(g/mL),提取温度92.30℃,提取时间219.01 min有最大多糖提取率。提取率为16.68%,与试验模型预测提取率为16.81%相近。本研究对绿穗苋多糖提取优化的研究为进一步探讨绿穗苋多糖生物活性的的研究提供了材料基础。     

响应面法优化乌骨藤通光藤苷G提取工艺

利用响应面法对乌骨藤Marsdenia tenacissima通光藤苷G的提取工艺进行优化。以通光藤苷G提取率为指标,在单因素试验的基础上,选取乙醇浓度、料液比、提取时间、提取次数进行4因素3水平的Box-Behnken中心组合研究,并运用Design Expect 8.0软件对试验参数进行分析,研究各自变量及其交互作用对通光藤苷G提取率的影响。结果显示,通光藤苷G的最佳提取条件为：乙醇溶液浓度80%,料液比1∶20(W/V),提取时间1.5 h,提取2次,在此条件下,通光藤苷G提取率为0.253%。     

响应面法优化余甘叶中黄酮提取工艺

以余甘叶为试材,利用超声波辅助提取余甘叶黄酮,研究料液比、乙醇浓度、超声时间、超声功率对黄酮提取率的影响,并在单因素试验的基础上,通过响应面分析法优化提取工艺。结果表明,余甘叶中黄酮最佳超声提取条件为：料液比1∶73、乙醇浓度50%、超声时间30 min、超声功率210 W,在此条件下黄酮实际提取率为19.51%。     

基于响应曲面法的龙须藤多糖提取条件优化

采用响应曲面法分析与确定龙须藤多糖提取工艺,通过单因素实验确定影响多糖提取的主要影响因素,然后在单因素实验的基础上,采用响应曲面法分析提取因素对龙须藤多糖含量的影响,得出龙须藤多糖提取的最优条件为:提取温度100℃、提取时间4 h、料液比1∶23、提取次数为2次。在此条件下龙须藤多糖提取率理论值为3.12%,实测值为2.98%。     

正交试验法优化半夏多糖的提取工艺

目的:建立半夏多糖的最佳提取工艺.方法:采刚水提醇沉法,以多糖提取率为指标,通过单因素试验和正交试验,确定半夏多糖的最住提取工艺条件.结果:最佳水提条件为料液比1:30,70℃提取1h,提取3次,最佳醇沉工艺条件为醇沉浓度70%,静置时间12h.在此条件下,半夏多糖的提取率为13.68%.结论:该工艺简便,重复性好,多糖的提取率高.     

响应面法优化苦荞麸皮粉蛋白质提取工艺

目的：分析苦荞麸皮粉中蛋白含量及其蛋白组成。方法：采用碱法提取-等电点沉淀分离蛋白。在单因素试验基础上,选取料液比（w/v）、pH、时间等3个影响因素,采用响应面法 （Box-Behnken 中心组合）优化苦荞麸皮粉蛋白提取工艺。结果：料液比、pH、时间对麸皮蛋白提率有显著影响,影响顺序为料液比> pH>时间。响应面优化得到最佳提取条件为pH 10.5、料液比1∶35、时间3 h 40 min,此条件下苦荞麸皮蛋白提取率为（97.31±4.64）%。结论：本研究为有效开发利用苦荞麸皮粉的蛋白提供科学依据。     

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.     

Determination of stoichiometry of radioiodination of proteins

A sensitive method for the detection of small quantities of hydrophobic antioxidant free radical scavengers such as butylatedhydroxytoluene (BHT) and butylatedhydroxyanisole (BHA) in aqueous samples is described. The procedure involves extraction of the hydrophobic free radical scavenger into an organic solvent phase, followed by the subsequent reaction of an aliquot of this extract with the stable cation radical tris(p-bromophenyl)amminium hexachloroantimonate (TBACA). In experiments with BHT and BHA, the loss of TBACA absorbance at 730 nm was found to be linearly proportional to the amount of antioxidant added, with quantities of BHT as small as 200 pmol being easily detectable. In aqueous suspensions of dimyristoylphosphatidylcholine vesicles, assays of the aqueous BHT concentration showed that BHT partitioned strongly into the membrane phase, achieving very high BHT/phospholipid ratios. For a given concentration of BHT, partitioning into the membrane phase was greater in large, multilamellar liposomes than in either small, single-walled vesicles or in purified rat brain synaptic vesicle membranes. Direct assay of BHT and BHA in phospholipid membranes, however, was complicated by a nonspecific interaction between TBACA and the phospholipid.