黄芪多糖三种提取工艺比较

目的：优选黄芪多糖提取的最佳工艺。方法：分别用水提取大孔树脂分离法、水提醇沉法、超声提取法提取多糖,比较三种工艺提取黄芪多糖提取率。并采用分光光度法测定黄芪多糖含量。结果：水提取大孔树脂分离法的黄芪多糖提取率为4．186％,舍量为26．19％;水提醇沉法的黄芪多糖提取率为4．468％,含量为29．40％;超声提取法的黄芪多糖提取率为3．420％．含量为30．95％。结论：水提醇沉法是黄芪多糖提取率及含量比较理想的方法。     

黄芪地上部分有效成分研究

目的：对黄芪地上部分有效成分进行研究。方法：采用紫外分光光度法,对黄芪茎和花中的总黄酮、总皂苷和多糖进行含量测定。结果：测得茎中总黄酮含量为1．621mg／g,总皂苷含量为1.768mg／g,多糖含量为12.057mg／g,花中总黄酮含量为4．389mg／g,总皂苷含量为21．842mg／g,多糖含量为11．213mg／g。结论：黄芪地上部分有一定利用价值。     

黄芪多糖口服液质量标准研究

目的：建立黄芪多糖口服液的质量标准。方法：通过薄层色谱法进行鉴别；通过紫外分光光度法进行含量测定。结果：通过薄层色谱法进行鉴别，结论合格；通过紫外分光光度法进行含量测定，暂定本品含量以葡萄糖计，每m1不少于7．0mg。结论：该法操作简便，结果准确、可靠。     

蒙古黄芪多糖含量测定的方法学研究

目的建立蒙古黄芪多糖含量测定方法。方法制备蒙古黄芪多糖样品,并采用紫外分光光度法测定蒙古黄芪多糖含量。结果多糖供试液显色稳定,重现性好,平均加样回收率为98.67%,RSD=2.05%(n=9)。结论此方法简单、快速、重复性好,可用于蒙古黄芪中多糖含量的控制。     

蒙药瞿麦中多糖超声提取工艺研究及含量测定

目的研究瞿麦中多糖的超声提取方法及其含量测定的方法。方法采用苯酚-硫酸法显色,并以紫外-可见分光光度计测定瞿麦中多糖含量,以其作为评价指标,先后通过单因素试验和正交试验来确定提取瞿麦多糖的最佳工艺条件。结果超声法提取瞿麦中多糖的最佳工艺为料液比为1：20,温度60℃,超声时间为30 min,提取2次。各因素影响顺序为提取温度〉提取时间〉提取次数〉料液比,测得瞿麦中多糖含量为5.463%,平均回收率为98.6%,RSD=1.5%（n=6）。结论以上工艺为运用超声技术从瞿麦中提取出多糖的最佳工艺。采用紫外可见分光光度法测定瞿麦中多糖含量的方法简便、快速、灵敏,结果准确可靠,可作瞿麦中多糖的含量测定方法。     

不同提取工艺对黄芪精口服液中成分的影响

目的：采用水醇法和离心法工艺分别提取黄芪,用其提取液制备黄芪精口服液,对两种工艺制得的口服液中黄芪甲苷和黄芪多糖的含量进行比较,离心法工艺制得的口服液中黄芪多糖含量优于水醇法。方法：运用水醇法和离心法对黄芪进行有效成分提取,采用紫外分光光度法与薄层扫描法测定黄芪多糖和黄芪甲苷含量。结果：离心法中黄芪多糖和黄芪甲苷含量均高于水醇法。结论：离心法有效成分损失少,值得大力推广,适宜工业生产。     

沙枣多糖的超声提取及含量测定

目的　从沙枣中提取多糖并测定其含量。方法　采用超声法提取 ,分光光度法测定多糖含量。结果　用超声法提取测得沙枣多糖含量为 6 .81% ,较常规法高出近 5 0 %。结论　多糖提取可优选超声法。     

不同种类黄芪的皂苷含量比较

目的　测定不同种类黄芪的皂苷含量。方法　以 70 %乙醇为溶剂连续回流提取 ,采用紫外分光光度法在 5 4 4 nm波长处测定黄芪的皂苷含量。结果　不同种类黄芪中皂苷的含量分别为 :蒙古黄芪 0 .336 % ,膜荚黄芪 0 .118% ,天然黄芪 0 .314 %。结论　蒙古黄芪中皂苷含量最高     

甘草多糖的超声提取及含量分析

目的 从甘草中提取多糖并测定其含量。方法 采用超声法提取，分光光度法测定多糖含量。结果 甘草中多糖含量为14.01％，平均回收率为98．61％，RSD 1．14％(n=6)。结论 超声法提取多糖，速度加快，收率提高。     

莲子心中总黄酮含量测定方法的研究

目的：研究莲子心中总黄酮含量的测定方法。方法以芦丁为对照品,可见分光光度法用氯化铝作显色剂,在510nm波长测定总黄铜含量;紫外分光光度法在358nm 波长下测定总黄酮含量。结果可见分光法的回收率为98．47％,RSD 为0．24％;紫外分光法的回收率为97．10％,RSD为0．35％,比较两种方法的测定结果无显著性差异。结论可见分光光度法显色不稳定,紫外分光光度法显色稳定,且快速和简便,可用于莲子心中总黄酮的含量测定。     

黄芪中黄芪多糖含量测定方法的比较

比较了采用苯酚-浓硫酸比色法和蒽酮-浓硫酸比色法,以葡萄糖和葡聚糖(分子量约20000)两种对照品测定黄芪中多糖含量的方法.结果显示,以葡聚糖为对照品、蒽酮-浓硫酸比色法测定线性关系较好(r=0.9990),平均回收率97.9%,RSD 1.53%.并测定了7个品种黄芪药材中黄芪多糖的含量.     

黄芪多糖的药理作用研究进展

本文综述了黄芪多糖对增强免疫系统、抗肿瘤、保肝、降血糖、抗病毒、抗氧化延缓衰老等方面的药理活性,为黄芪多糖药理作用的进一步研究提供参考。     

不同产地黄芪中总黄酮含量的比较

目的:探讨不同产地黄芪总黄酮含量的差异.方法:以芦丁为对照,采用紫外分光光度法测定黄酮含量.结果:不同产地黄芪总黄酮含量为河北:5.511 mg/g,山西:5.391 mg/g,吉林:5.300 mg/g,甘肃:4.755 mg/g,内蒙:4.737 mg/g,陕西: 4.404 mg/g,青海: 3.472 mg/g. 结论:不同产地黄芪总黄酮含量存在明显差异.从样本数据的均值分析,总黄酮含量从高到低依次为河北、山西、吉林、甘肃、内蒙、陕西、青海.     

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.     

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.