高效液相色谱法测定不同生长年限南方红豆杉中紫杉醇的含量

目的 采用高效液相色谱法测定不同生长年限南方红豆杉中紫杉醇的含量。方法 采用Hypersil BDS C18色谱柱（200nlm×4．6mm，5μm），流动相为甲醇-水（58：42），流速1．0mL·min^-1，检测波长为227nm，柱温为25＇C。结果紫杉醇的线性范围为192～960ng，r=0．9999，平均回收率为97．56％，RSD为1．17％。结论 建立的方法可靠，可用于南方红豆杉中紫杉醇的含量测定。     

HPLC测定曼地亚红豆杉中的紫杉醇

目的 采用RP-HPLC法测定曼地亚红豆杉中紫杉醇的含量.方法 采用Diamond C_(18)色谱柱(250 mm×4.6 mm,5 μm),流动相为乙腈-水(52:48),流速1.0 mL·min~(-1),检测波长227 mn,柱温30 ℃.结果 曼地亚红豆杉枝叶中紫杉醇的平均含量达0.0237%,该检测方法可将紫杉醇与其类似物分离.结论 曼地亚红豆杉枝叶中紫杉醇的含量较高,该检测方法稳定,可用于紫杉醇的快速定量测定.     

高效液相色谱法测定南方红豆杉细胞悬浮液中紫杉醇含量

目的建立南方红豆杉细胞悬浮液中紫杉醇含量测定高效液相色谱法。方法以Unitary C18色谱柱（5μm,150.0 mm×4.6 mm）为分析柱,乙腈-水为流动相,流速为1.0 mL min-1,检测波长为227 nm,柱温30℃;进样量20μL。结果南方红豆杉细胞悬浮液中紫杉醇在此色谱条件下分离效果良好,其质量浓度在3.99～79.8 mg L-1（r=0.999 5）与峰面积呈良好的线性关系,平均加样回收率为99.1%,RSD值为2.5%。结论该方法操作简便、准确,重现性好,为南方红豆杉细胞悬浮液中紫杉醇的测定及其质量控制奠定了基础。     

UPLC法测定度鲁特韦有关物质含量

目的:建立测定度鲁特韦原料药有关物质含量的超高效液相色谱方法.方法:色谱柱为Waters BEH C18(2.1 mm×150 mm×1.7μm),流动相:10 mmol·L-1甲酸铵溶液(pH=2.5)为流动相A,乙腈为流动相B,梯度洗脱:0～15 min,流动相B 20％ ～80％,柱温30℃,流速0.28 mL·...     

我国不同种类红豆杉不同部位紫杉醇的含量分布研究

目的:建立红豆杉中紫杉醇的提取纯化方法和紫杉醇高效液相色谱分析方法,分析研究了我国境内中国红豆杉、云南红豆杉、西藏红豆杉、东北红豆杉、南方红豆杉以及曼地亚红豆杉不同部位紫杉醇含量的差异,寻找其分布规律。方法:以乙酸乙酯-丙酮(1∶1)为提取溶剂进行提取,采用自制碱性氧化铝柱进行柱层析纯化;色谱条件:采用 AichromBond-AQ C_(18)(250 mm×4.6 mm,5μm)分析柱,以甲醇-乙腈-水(18∶40∶42)为流动相,流速1.0 min·mL~(-1),柱温40℃,于228 nm 波长处进行检测。结果:红豆杉各部化紫杉醇含量差异明显,其中叶、枝条、根和树皮的平均含量分别为0.015%,0.018%,0.055%,0.077%。中国红豆杉、云南红豆杉、西藏红豆杉、东北红豆杉、南方红豆杉以及曼地亚红豆杉树木各部位的平均含量分别为0.032%,0.050%,0.034%,0.043%,0.044%,0.046% 结论:鉴于红豆杉的枝和叶中也含有相当量的紫杉醇且再生能力较强,故应以红豆杉的枝叶为原料进行提取、分离,对红豆杉的保护和合理开发利用都具有现实意义,其中尤以云南红豆杉开发利用价值最高。     

HPLC法测定南方红豆杉种子中紫杉醇的含量

目的:建立高效液相色谱测定南方红豆杉种子中紫杉醇含量的方法.方法:采用Whatman C18 (250 mm × 4.6 mm,5.0 μm) 色谱柱,柱温30℃;流动相为乙腈-水(35∶65-80∶20)30 min梯度洗脱,流速1.0 mL/min;检测波长227 nm.结果:紫杉醇的线性范围:8.5 ~ 51.0...     

南方红豆杉与引种德国曼地亚红豆杉茎、叶中紫杉醇和10-脱乙酰巴卡亭Ⅲ含量的比较

目的建立HPLC法同时测定并比较南方红豆杉与德国引种曼地亚红豆杉茎、叶中紫杉醇和10-脱乙酰巴卡亭Ⅲ含量。方法采用Cosmasil TMC18色谱柱(250mm×4.6mm,5μm);以乙腈-水(50∶50)为流动相;流速为1.0mL·min-1;检测波长为227nm;柱温:30℃。结果紫杉醇、10-脱乙酰巴卡亭Ⅲ的线性范围分别为2.675⁴2.8μg·mL-1(r=0.999 3)和3.87542.8μg·mL-1(r=0.999 3)和3.875⁶2μg·mL-1(r=0.999 6),平均加样回收率(n=9)分别为98.1%和101.6%,RSD分别为2.7%和2.3%。南方红豆杉与德国引种曼地亚红豆杉的茎、叶中紫杉醇含量分别为0.12和0.10mg·g-1,10-脱乙酰巴卡亭Ⅲ含量分别为0.12和0.14mg·g-1。结论引种红豆杉与南方红豆杉在同一地区的生态环境下生长,茎、叶中所含紫杉醇和10-脱乙酰巴卡亭Ⅲ含量有显著性差异(P<0.05)。所建立方法准确,简便,适用于红豆杉的质量评价,为不同栽培品种的选择提供参考。     

HPLC-DAD法同时测定复合维生素B片中4种维生素的含量

目的:建立反相高效液相色谱法同时测定复合维生素B片中4种维生素含量。方法:采用梯度洗脱反相高效液相色谱法,ZORBAX Ecliose XDB-C18(4.6 mm×250 mm,5μm)色谱柱,流动相A为含0.1%三乙胺的0.05 mol·L-1磷酸二氢钾溶液(pH 4.6);流动相B为甲醇,检测波长为266 nm、柱温为40℃、流速为1.0 mL·min-1。结果:4种维生素含量测定方法的线性关系良好,r 0.999 5～0.999 9,方法回收率均在99.2%～100.6%范围内,RSD均在0.8%～2.0%之间。结论:本方法简便快捷,灵敏准确,可以用于复合维生素B片的质量控制。     

喜马拉雅红豆杉与曼地亚红豆杉中紫杉醇和三尖杉宁碱含量比较

目的测定并比较维吾尔药材喜马拉雅红豆杉与人工栽培品种曼地亚红豆杉中紫杉醇和三尖杉宁碱的含量。方法采用RP-HPLC色谱法梯度洗脱,色谱柱为Century SIL C18-EPS柱(250 mm×4.6 mm,5μm);流动相为乙腈-水;流速为1.0mL·min-1;检测波长为227nm;柱温为30℃。结果紫杉醇回归方程:Y=2.050 975×107 X+5 531.887,线性范围为0.042~1.69μg(r=0.999 9),平均回收率为98.0%,RSD=0.98%(n=6);三尖杉宁碱回归方程Y=1.806 535×107 X+3 046.378,线性范围为0.040~1.6μg(r=0.999 9),平均回收率为96.6%,RSD=2.97%(n=6),喜马拉雅红豆杉叶中三尖杉宁碱平均含量高于茎中含量,曼地亚红豆杉相反;两者叶中紫杉醇含量高于茎中含量,而曼地亚红豆杉茎叶中紫杉醇含量并不低于喜马拉雅红豆杉。结论该方法简便、准确、适用于红豆杉药材的质量评价。     

阿莫西林克拉维酸钾制剂中有关物质超高效液相色谱分析方法的建立

目的:建立超高效液相色谱方法,用于分析阿莫西林克拉维酸钾制剂中的有关物质.方法:采用超高效液相色谱法,色谱柱为ACQUITY UPLC BEH-C18(2.1mm×100mm,1.7μm);流动相A为0.01mol·L-1磷酸二氢钾溶液(用2mol·L-1氢氧化钠溶液调节pH至6.0),流动相B为乙腈;进行梯度洗脱;检...     

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.     

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.     

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.