Box-Benhnken响应面法优化超声波辅助提取银耳多糖工艺的研究

摘 要 目的：利用Box Behnken响应面法对超声波辅助提取银耳多糖工艺进行优化。方法: 在单因素试验基础上,选择超声波功率、超声时间和液料比为考察因素,以银耳多糖提取率为评价指标,采用Box Behnken响应面法考察各个因素及其交互作用对银耳多糖提取率的影响。结果: 最佳提取工艺为：超声波功率为360 W,超声时间为23 min,液料比为45∶1 ml·g^-1。在优化提取工艺参数条件下提取6批银耳多糖,平均提取率为20.4%±1.8%（n=6）。结论:利用Box-Behnken响应面法优化超声波辅助提取银耳多糖工艺,方法简便,预测性良好。     

基于正交设计和BP神经网络-遗传算法多指标综合优化茶叶提取工艺

目的 用正交设计及BP神经网络-遗传算法对茶叶提取工艺进行多指标综合优化。方法 以咖啡因、表没食子儿茶素没食子酸酯（epigallocatechin gallate,EGCG）、表儿茶素没食子酸酯（epicatechin gallate,ECG）为考察指标,在单因素实验的基础上,采用正交设计及BP神经网络-遗传算法优选超声辅助提取茶叶中有效成分的工艺,并对2种方法优选所得的工艺进行验证。结果 正交设计得到的最佳提取条件为乙醇浓度85%、浸提温度80℃、超声时间10 min。工艺验证评分为99.050。BP神经网络-遗传算法得到的最优提取方案为乙醇浓度89%、浸提温度88℃、超声时间13 min,网络预测评分为100.758,工艺验证评分为99.651,相对误差为1.099%。结论 BP神经网络-遗传算法数学模型可用于茶叶中有效成分提取工艺预测和优选,且略优于正交设计。     

响应面设计优化抗癌散总黄酮提取工艺

摘 要 目的： 采用响应面分析法对复方抗癌散总黄酮热回流提取工艺进行优化。方法: 以单因素试验选择了提取时间、乙醇浓度、料液比3个因素为自变量,总黄酮提取率为响应值,通过3因素3水平的响应面分析,确定最佳提取工艺条件。结果: 最佳工艺条件为乙醇浓度64.56%,料液比为1∶26.97,提取时间为2.29 h,提取温度为85℃,总黄酮提取率可达45.94 mg·g^-1。结论: 采用响应面分析法对复方抗癌散总黄酮提取条件优化合理可行,可为其工业生产提供工艺参数依据。     

Box-Behnken响应面法优化翻白草总黄酮的提取工艺

摘 要 目的：运用Box-Behnken响应面法优化翻白草中总黄酮的提取工艺。方法: 在单因素试验基础上,以提取时间、乙醇浓度以及料液比为考察因素,以翻白草总黄酮提取率为评价指标,利用 Box-Behnken 响应面法优化翻白草中总黄酮的提取工艺。结果: 提取的最佳工艺为：提取浓度为70%的乙醇,每次120 min,液料比为8∶1 ml·g^-1时,黄酮的提取率最高,总黄酮提取率预测值为3.86%,测定值为3.74%,其间相差0.12%。结论:使用Box-Behnken响应面法优化翻白草总黄酮的提取工艺科学可靠,可用于翻白草总黄酮的提取生产。     

星点设计-效应面法优选金荞麦提取工艺

目的优选金荞麦中表儿茶素的提取工艺。方法以微波功率、乙醇浓度、料液比、提取时间为自变量,表儿茶素提取率为因变量,通过对自变量各水平的多元线性回归及二项式拟合,用星点设计 效应面法选取最佳工艺,并进行预测分析。结果最佳工艺条件为微波功率211.89 W,乙醇浓度55.11%,料液比1：11.43,提取时间6.16 min,金荞麦中表儿茶素提取率的最大估计值为2.041 4%。实验结果与模型预测值相符。结论该方法简便合理,稳定,可预测性较优,可作为金荞麦的提取工艺。     

金线莲多糖的提取优化与纯化

目的 以响应面法优化超声提取金线莲多糖的工艺,同时,对多糖纯化中除蛋白方法进行考察。方法 以多糖提取率为检测指标,在单因素考察的基础上采用Box-Behnken实验设计及响应面法对料液比、超声时间、超声提取温度3个因素进行优化;以多糖保留率和蛋白脱除率对Sevage试剂法、TCA法、盐法（NaOH-CaCl₂法和NaOH-NaCl法）、盐酸法5种脱蛋白方法进行考察。结果 金线莲多糖最佳提取工艺为: 料液比1∶10,超声提取温度48 ℃,超声提取时间36 min,超声提取次数2次,超声功率为300 W,该条件下金线莲多糖提取率达到了13.13%;同时以NaOH-CaCl₂法脱蛋白,多糖损失率为18.74%,蛋白脱除率为95.62%。结论 超声提取操作简单,优化后提取方法能够取得较高提取率,NaOH-CaCl₂法脱蛋白能够获得较高蛋白脱除率及多糖保留率,该方法适用于金线莲多糖活性成分的开发研究。     

正交试验法优选狼毒大戟中活性成分的提取工艺

摘 要 目的：优选狼毒大戟中活性成分的最佳提取工艺。方法: 选用L9(3⁴ )正交试验设计,以提取物中岩大戟內酯B和狼毒乙素的含量为指标,考察乙醇浓度、溶剂用量、提取温度和提取时间对提取效果的影响。结果:最佳提取工艺为料液比1∶〖KG-*2〗10,加入浓度为70%的乙醇溶液,以70 ℃为提取温度,加热回流提取1 h。结论:优选得到的提取工艺稳定、合理、可行,操作简单,能耗低,大大提高了岩大戟内酯B和狼毒乙素的提取率。     

超声提取鬼灯檠中岩白菜素的最佳工艺研究

目的 建立超声波提取鬼灯檠中岩白菜素的最佳工艺。方法 以岩白菜素提取量为指标,在单因素实验的基础上,采用正交实验对岩白菜素的超声提取工艺进行优选。考察提取温度、料液比、提取功率、提取时间及提取次数对岩白菜素提取量的影响。结果 提取次数、提取时间和料液比对岩白菜素提取率的影响起主要作用,超声提取的最佳工艺为：料液比1∶14,超声波功率为60 W,提取温度为70 ℃,超声波提取时间60 min,提取4次。结论 通过验证实验, 表明所选的工艺条件可行,在该工艺条件下岩白菜素的提取率为12.588 5 mg·g^-1。     

Plackett-Burman设计结合Box-Behnken响应面法优化紫斑牡丹籽壳中低聚芪类和单萜苷类化合物的超声提取工艺

目的 优化紫斑牡丹籽壳中低聚芪类和单萜苷类化合物的超声提取工艺。方法 以HPLC测得的芍药苷和白藜芦醇得率为指标,采用综合评分法,在提取功率、液料比、提取温度、提取时间、乙醇浓度和提取次数6个单因素试验的基础上,通过Plackett-Burman试验从中遴选显著因素,进而采用Box-Behnken响应面法优化紫斑牡丹籽壳中低聚芪类和单萜苷类化合物的超声提取工艺。结果 优化得到的超声提取工艺为乙醇浓度75%、液料比30mL·g^-1、提取功率210 W、温度50.0℃、提取50min、提取2次。在此最佳工艺下,芍药苷和白藜芦醇的得率分别为5472.43,1633.11μg·g^-1,实测值与预测值基本相符。结论 优化得到的紫斑牡丹籽壳中低聚芪类和单萜苷类化合物的超声提取工艺合理,可为其后续的应用研究提供参考。     

BP神经网络结合遗传算法优化灰树花多糖提取工艺

目的 通过BP神经网络结合遗传算法,对灰树花多糖提取工艺进行优化,以探讨最佳提取工艺。方法 采用水提醇沉法,以多糖提取率为检测指标,采用3因素（提取温度、提取时间、液料比）4水平正交试验对多糖提取工艺进行考察。用BP神经网络模型结合遗传算法对试验结果进行目标寻优,并通过正交分析法进行验证,获得灰树花多糖的最佳提取工艺。结果 BP神经网络结合遗传算法处理分析得到优化结果为提取温度79.6℃,提取时间3.4 h,液料比50：1,此方法下多糖提取率为6.754%。结论 BP神经网络结合遗传算法优化灰树花多糖提取工艺的方法有效可靠,可为同类提取工艺的优化提供新思路。     

Efficacy of gut lavage,hemodialysis, and hemoperfusion in the therapy of paraquat or diquat intoxication

Clinical and in vitro investigations were carried out to test the efficacy of gut lavage, hemodialysis, and hemoperfusion in the treatment of poisoning with paraquat or diquat. In a patient suffering from diquat intoxication 130 times more diquat was removed by gut lavage 30 h after ingestion than was removed by complete aspiration of the gastric contents.Determination of in vitro clearances for paraquat and diquat by hemodialysis showed that, at serum concentrations of 1–2 ppm, such as are frequently encountered in poisoning in man, toxicologically relevant quantities of herbicide cannot be removed from the body. At a concentration of 20 ppm, on the other hand, hemodialysis proved to be effective, the clearance being 70 ml/min at a blood flow rate of 100 ml/min. The efficacy of hemoperfusion with coated activated charcoal was on the whole better. Especially at concentrations around 1–2 ppm, the clearance values for hemoperfusion were some 5–7 times higher than those for hemodialysis.In a patient suffering from paraquat poisoning, both hemodialysis as well as hemoperfusion were carried out. The in vitro results could be confirmed: At serum concentrations of paraquat less than 1 ppm no clearance could be obtained by hemodialysis while by hemoperfusion with activated charcoal quite high clearance values were measured and the serum level dropped down to zero.

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Zusammenfassung Klinische Untersuchungen und Laboratoriumsversuche wurden durchgeführt, um die Wirksamkeit von Darmspülung, Hämodialyse und Hämoperfusion bei Paraquat- und Deiquat-Vergiftungen zu prüfen.Bei einem Patienten wurde 30 Std nach Deiquat-Aufnahme durch Darmspülung 130mal mehr Deiquat entfernt als durch vollständige Aspiration des Mageninhaltes. In vitro-Versuche ergaben, daß bei Blutserumkonzentrationen von 1–2 ppm, die bei Vergiftungen oft gemessen werden, durch Hämodialyse keine toxikologisch relevanten Paraquat- oder Deiquat-Mengen entfernt werden können. Dagegen erwies sich die Hämodialyse bei 20 ppm und einer Blutumlaufgeschwindigkeit von 100 ml/min mit einer Clearance von 70 ml/min als wirksam. Die Hämoperfusion mit beschicheter Aktivkohle war in diesen Versuchen aber eindeutig überlegen, denn insbesondere bei Konzentrationen um 1–2 ppm waren die Clearance-Werte 5–7mal höher als bei der Hämodialyse.Die in vitro-Ergebnisse wurden bei einem Patienten mit einer Paraquat-Vergiftung bestätigt: Bei Konzentrationen unter 1 ppm war die Hämodialyse wirkungslos, während durch Hämoperfusion relativ hohe Clearance-Werte erreicht wurden, so daß der Serumspiegel rasch unter die Nachweisgrenze abfiel.

     

In vitro studies on sterically stabilized liposomes (SL) as enzyme carriers in organophosphorus (OP) antagonism

This study describes a new approach for organophosphorous (OP) antidotal treatment by encapsulating an OP hydrolyzing enzyme, OPA anhydrolase (OPAA), within sterically stabilized liposomes. The recombinant OPAA enzyme was derived from Alteromonas strain JD6. It has broad substrate specificity to a wide range of OP compounds: DFP and the nerve agents, soman and sarin. Liposomes encapsulating OPAA (SL)* were made by mechanical dispersion method. Hydrolysis of DFP by (SL)* was measured by following an increase of fluoride ion concentration using a fluoride ion selective electrode. OPAA entrapped in the carrier liposomes rapidly hydrolyze DFP, with the rate of DFP hydrolysis directly proportional to the amount of (SL)* added to the solution. Liposomal carriers containing no enzyme did not hydrolyze DFP. The reaction was linear and the rate of hydrolysis was first order in the substrate. This enzyme carrier system serves as a biodegradable protective environment for the recombinant OP-metabolizing enzyme, OPAA, resulting in prolongation of enzymatic concentration in the body. These studies suggest that the protection of OP intoxication can be strikingly enhanced by adding OPAA encapsulated within (SL)* to pralidoxime and atropine.     

Pharmacological treatment of COVID-19: an opinion paper

The precocity and efficacy of the vaccines developed so far against COVID-19 has been the most significant and saving advance against the pandemic. The development of vaccines has not prevented, during the whole period of the pandemic, the constant search for therapeutic medicines, both among existing drugs with different indications and in the development of new drugs. The Scientific Committee of the COVID-19 of the Illustrious College of Physicians of Madrid wanted to offer an early, simplified and critical approach to these new drugs, to new developments in immunotherapy and to what has been learned from the immune response modulators already known and which have proven effective against the virus, in order to help understand the current situation.     

Steroidal sapogenin contents in some domestic plants

In order to find out the values of the steroid resources for the future use. the compositions and contents of steroidal sapogenins from 13 domestic plants have been investigated. As a result,Dioscorea nipponica, D. quinqueloba andSmilax china were found to have large amount of diosgenin. And pennogenin inTrillium kamtschaticum andParis verticillata, yuccagenin inAllium fistulosum, hecogenin inAgave americana and neochlorogenin inSolanum nigum were appeared to be major steroidal sapogenins.     

Aquatic Insects and Trace Metals: Bioavailability,Bioaccumulation, and Toxicity

Abstract

The uptake of metals from food and water sources by insects is thought to be additive. For a given metal, the proportions taken up from water and food will depend both on the bioavailable concentration of the metal associated with each source and the mechanism and rate by which the metal enters the insect. Attempts to correlate insect trace metal concentrations with the trophic level of insects should be made with a knowledge of the feeding relationships of the individual taxa concerned. Pathways for the uptake of essential metals, such as copper and zinc, exist at the cellular level, and other nonessential metals, such as cadmium, also appear to enter via these routes. Within cells, trace metals can be bound to proteins or stored in granules. The internal distribution of metals among body tissues is very heterogeneous, and distribution patterns tend to be both metal and taxon specific. Trace metals associated with insects can be both bound on the surface of their chitinous exoskeleton and incorporated into body tissues. The quantities of trace meals accumulated by an individual reflect the net balance between the rate of metal influx from both dissolved and particulate sources and the rate of metal efflux from the organism. The toxicity of metals has been demonstrated at all levels of biological organization: cell, tissue, individual, population, and community. Much of the literature pertaining to the toxic effects of metals on aquatic insects is based on laboratory observations and, as such, it is difficult to extrapolate the data to insects in nature. The few experimental studies in nature suggest that trace metal contaminants can affect both the distribution and the abundance of aquatic insects. Insects have a largely unexploited potential as biomonitors of metal contamination in nature. A better understanding of the physico-chemical and biological mechanisms mediating trace metal bioavailability and exchange will facilitate the development of general predictive models relating trace metal concentrations in insects to those in their environment. Such models will facilitate the use of insects as contaminant biomonitors.     

Alzheimer’s disease – current trends in basic and clinical research. Highlights from the 16th ECNP

Advances in the molecular biological knowledge of neuronal nicotinic acetylcholine receptors (nAChRs) have led to a growing interest by the pharmaceutical industry in the development of novel compounds that selectively modulate nAChR function. The ability of (-)-nicotine, an activator of nAChRs, to enhance attentional aspects of cognition in animals and humans, to exert neuroprotective and anxiolytic-like effects, and presumably to mediate the negative correlation between smoking and Alzheimer's (and Parkinson's) Disease, has focused interest on the potential therapeutic utility of modulators of nAChR function for treatment of some of the deficits associated with these progressive, neurodegenerative conditions. Numerous compounds are known which activate nAChRs and which might serve as lead compounds toward the development of such agents. The pharmacologic diversity of neuronal nAChR subtypes suggests the possibility of developing selective compounds which would have more favourable side-effect profiles than existing agents. This broader class of agents, collectively called cholinergic channel modulators (ChCMs), is anticipated to encompass compounds which would have more favourable side-effect profiles than existing agents, which generally exhibit low selectivity. This selectivity may be achieved by preferentially activating some subtypes of nAChRs (i.e., Cholinergic Channel Activators, ChCAs) or inhibiting the function of other subtypes (Cholinergic Channel Inhibitors, ChCIs). An overview of the biology of nAChRs and the rationale for the use of ChCMs for the treatment of dementia related to neurodegenerative diseases are presented, followed by a discussion of lead compounds and compounds under consideration for clinical evaluation.