Studies on Quantitative Determination of Active Principles in Chinese Herbal Medicine by Second Derivative Differential Pulse Polarography

本文建立了中草药黄芩中黄芩甙、青黛中靛蓝、牡丹皮中丹皮酚、荜茇中胡椒碱的二阶导数差示脉冲极谱的定量分析方法。黄芩、靛蓝、丹皮酚和胡椒碱的化学结构中都含有ＣＯ，在酸性条件下，于滴汞电极上均可发生还原反应生成ＣＯ，并分别于１５５０Ｖ，１３００Ｖ，１６３０Ｖ，０８６０Ｖ（ｖｓＡｇ／ＡｇＣｌ）处出现良好的二阶导数差示脉冲极谱峰。黄芩、靛蓝、丹皮酚和胡椒碱分别在４５×１０５～２７×１０４ｍｏｌ·Ｌ１，３８×１０５～２５×１０４ｍｏｌ·Ｌ１，１０～６０×１０４ｍｏｌ·Ｌ１和７０×１０５～２５×１０４ｍｏｌ·Ｌ１范围内，浓度与其二阶导数差示脉冲极谱峰幅值呈极为显著的线性关系（Ｐ〈００１），检测限分别为９０×１０８ｍｏｌ·Ｌ１，８４×１０９ｍｏｌ·Ｌ１，９２×１０９ｍｏｌ·Ｌ１和８７×１０９ｍｏｌ·Ｌ１。方法简便、快速、灵敏，结果准确。     

二阶导数差示脉冲极谱法用于扑尔敏及其制剂的定量研究

采用扑尔敏在水溶液中，于－０．４００ｖ处出现一良好的二阶导数差示脉冲极谱峰，在２．０－８．０×１０＾－４ｍｏｌ／Ｌ范围内，药物浓度与其导数差示脉冲极谱峰幅值呈非常显著的线性关系。     

红霉素及其制剂的二阶导数差示脉冲极谱法定量研究

运用二阶导数差示脉冲极谱法对红霉素及其制剂进行了定量研究。红霉素化学结构中９位碳上含有＞Ｃ＝Ｏ，可在酸性条件下，于滴汞电极上发生氧化还原反应生成＞ＣＨ－ＯＨ，并于－０．３０５Ｖ（ｖｓＡｇ／ＡｇＣｌ）处出现一良好的二阶导数差示脉冲极谱峰，在０．１～０．８ｍｍｏｌ／Ｌ范围内，浓度与其二阶导数差示脉冲极谱峰幅值呈非常显著的线性关系（Ｐ＜０．０１）。检测限为０．８ｎｍｏｌ／Ｌ。本法操作简便、快速、灵敏，结果准确。     

差示脉冲极谱法测定片剂中的普伐他汀钠

普代他汀钠（Ｐｒａｖａｓｔａｔｉｎｓｏｄｉｕｍ）为降血脂药。本文介绍新的差示脉冲极谱法（ＤＰＰ）定量分析片剂中的普伐他汀钠。方法包括用甲醇从片剂中抽提出普伐他汀钠，过滤，适当稀释，在－１．６～－２．６Ｖ记录ＤＰ极谱图，在－２．１０Ｖ对Ａｇ／ＡｇＣｌ（１ｍｏｌ．Ｌ－１四甲基溴化铰）观察到Ｅ峰。用浓度为８×１０－５～２．４×１０－４ｍｏｌ．Ｌ－１（３５．７３～１０７．１８ｕｇ·ｍＬ－１）的普伐他订钠标准溶液记录５个不同的ＤＰ极谱图，在ｉ峰和药物浓度（ｃ）间绘制校正曲线图，其回归方程是：ｉ峰＝１．１８…     

盐酸多西环素及制剂的一阶导数差示脉冲极谱测定

建立了盐酸多西环素及制剂的一阶导数差示脉冲极谱测定法。在１０～６０μｇ／ｍｌ范围内，药物浓度与峰幅值呈线性关系，检测限为７．５×１０－９ｍｏｌ／Ｌ。方法简便、快速、准确     

肉桂中肉桂酸的单扫描示波极谱法测定

本文报道一种测定肉桂中肉桂酸含量的单扫描示波极谱法。在０．４ｍｏｌ／Ｌ氯化铵－０．００２５ｍｏｌ／Ｌ盐酸（ｐＨ２．６±０．１）支持电解质溶液中肉桂酸在－１．３５Ｖ（ｖｓ．ＳＣＥ）有一极谱还原波。该波的一阶导数峰峰高与肉桂酸浓度在２．０×１０~（－６）～１．０×１０~（－４）ｍｏｌ／Ｌ范围内呈良好线性关系（ｒ＝０．９９９）．肉桂的其它成分如肉桂醛、肉桂醇、香豆素等不干扰测定。应用本方法测定广西肉桂中肉桂酸的含量，结果令人满意。     

差示脉冲极谱法测定片剂中的多沙唑嗪甲磺酸盐

多沙唑嗪甲磷酸盐（ｄｏｘａｚｏｓｉｎ，Ｉ）是血管舒张药。本文介绍差示脉冲极谱（ＤＰＰ）法检验片剂中的１，并同分光光度法的结果比较。ＤＰＰ法包括用甲醇从片剂中将１抽提出，过滤，适当稀释，在０．４～－０．４Ｖ记录ＤＰ极谱图，在０．０８８Ｖ（Ａｇ／ＡｇＣＩ，３ｍｏｌ·Ｌ－１ＫＣｌ）获得Ｅ４峰用Ⅰ的浓度为８．０～４０．０ｕｇ·ｍｌ．－１的标准溶液记录５个不同的ＤＰ极谱图，以ｉ峰和药物浓度制备标准曲线，其回归方程为：ｉ峰＝０．０２７９ｃ＋０．００５（ｒ＝０．９９９９）商品片剂，每片含４ｍｇ　　Ｉ，用ＤＰＰ…     

吡哌酸的电化学行为研究及其单扫示波极谱测定

吡哌酸在ｐＨ４．５,０．２ｍｏｌ／Ｌ的醋酸盐缓冲溶液中有灵敏的单扫极谱吸附波。在６×１０－８～２×１０－６ｍｏｌ／Ｌ范围内吡哌酸的浓度与其波高成直线关系,检测下限２×１０－８ｍｏｌ／Ｌ。利用该波测定了吡哌酸片中吡哌酸的含量,结果满意。吡哌酸在该溶液中的汞电极上的吸附服从Ｌａｎｇｍｕｉｒ等温线,吸附系数β＝５．４×１０５;电极反应的电子传递系数α＝０．６８,表面电极反应速率常数ｋｓ＝０．６８ｓ－１。     

用兔血小板膜受体筛选血小板激活因子（TAF）拮抗剂

在兔血小板膜中，血小板激活因子（ＰＡＦ）结合部位显示高度亲合性（Ｋｄ＝０．１±０．００７ｎｍｏｌ／Ｌ）、饱和性、显著的药理学特异性，其最大结合容量为２．８９±０．３２ｐｍｏｌ／ｍｇ蛋白。３Ｈ－ＰＡＦ饱和结合浓度为０．２ｎｍｏｌ／Ｌ。等温线表明为单一结合位点。红曲霉（Ｍｏｎａｓｃｕｓｓｐ．Ｆ４００）代谢产物中的小成份Ｄ（２Ａ）和Ｃ（４Ａ）与ＰＡＦ竞争受体结合部位，它们是ＰＡＦ的拮抗剂。Ｄ２Ａ的ＩＣ５０为３．１６×１０－５ｍｏｌ／Ｌ，Ｃ４Ａ的ＩＣ５０为３．０３×１０－５ｍｏｌ／Ｌ。     

二创导数差示脉冲极谱法用于血浆中氯氮zhou及其主要代谢？…

目的：测定血浆中氯氮ｚｈｏｕ及其主要代谢物的含量。方法：血浆用乙醚提取，经薄层层析分离，分别洗脱，残渣溶于５０ｍｍｏｌ．Ｌ＾－１Ｈ２ＳＯ４水溶液中，用是导数差示脉冲极谱法测定。结果：氟氮ｚｈｏｕ及其代谢物（Ⅰ、Ⅱ）的二阶导数差示脉冲极谱峰电位分别为：－０．６００Ｖ、－０．５９０Ｖ、－０．６４５Ｖ，检测限分别为：０．２７，０．１１，０．２２ｎｇ．ｍｌ＾－１。结论：该简便、快速、灵敏，结果准确。     

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.     

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.