枸橼酸莫沙必利的手性分离

目的采用高效液相和毛细管电泳建立枸橼酸莫沙必利对映体的分离方法。方法采用Chiral-AGP手性柱,以10mmol.L-1的甲酸铵-甲醇为流动相,进行液相色谱分离。采用未涂层石英毛细管(50μm×67cm,有效长度50cm),气压进样(50mbar,6s),柱温为20℃,分离电压为20kV,检测波长为200nm;运行缓冲液为含3%羟丙基-β-环糊精的100mmol.L-1硼砂溶液(pH值为2.5)。结果采用HPLC和HPCE方法均可以分离枸橼酸莫沙必利的两异构体。两个对映体HPLC的分离度为1.8,HPCE的分离度为3.1,HPCE的线性范围为20～300μg.mL-1,检测限为5μg.mL-1。结论在上述条件下能成功分离枸橼酸莫沙必利对映体,毛细管电泳法的分离效果优于高效液相色谱法。     

HPCE和HPLC测量导赤丸中盐酸小檗碱含量

目的建立毛细管电泳法（HPCE）与高效液相色谱法（HPLC）测定导赤丸中盐酸小檗碱含量的方法,并比较二者在测定本品中盐酸小檗碱含量方面的差异。方法采用盐酸-甲醇（1∶100）溶液提取导赤丸样品。HPCE分离条件为：熔融石英毛细管柱（67 cm×75μm,有效长度60 cm）,缓冲液体系为60 mmol.L-1磷酸二氢钾缓冲溶液-甲醇（65∶35）,pH 3.5,分离电压30 kV,毛细管柱温25℃,检测波长254 nm,进样时间5 s;HPLC分离条件为：C18柱（250 mm×4.6 mm,5μm）,柱温25℃,流动相为60 mmol.L-1磷酸二氢钾-甲醇（60∶40,用磷酸调pH3.5）,流速1.0 mL.min-1,检测波长254 nm。结果盐酸小檗碱在HPLC和HPCE各自的分离条件下进样浓度分别在5.03～30.18μg.mL-1、30.18～80.48μg.mL-1内表现出良好线性关系（r=0.999 8;r=0.999 8）,平均加样加收率分别为99.0%,100.8%,RSD分别为1.4%,0.6%。结论这两种方法均可用于导赤丸中盐酸小檗碱含量的测定,二者的测定结果稍有差异,HPCE测定盐酸小檗碱在柱效、分离时间、多组分生物碱分离上更有优势。     

西布曲明对映体的毛细管电泳分离与定量分析方法研究

目的:采用毛细管电泳分离西布曲明手性异构体,建立准确、快速的定量分析西布曲明及其对映体的方法。方法:对运行缓冲液离子强度、pH、手性选择剂浓度、有机溶剂添加剂、毛细管内径进行了选择。电泳条件为:石英毛细管柱内径75μm,总长65.0 cm,有效长度51.6 cm;紫外检测波长223nm;分离电压18 kV;温度25℃;电动力进样,进样电压18 kV,进样时间3s。结果:在20 mmol·L-1β-环糊精、30 mmol·L-1磷酸盐、pH 5.40的运行缓冲液中,西布曲明对映体达到了基线分离。西布曲明在0.031-0.412 mg·mL-1浓度范围内,线性关系良好,两对映体的检测限分别为11 μg·mL-1和10 μg·mL-1。在制剂其它成分共存时西布曲明的回收率为96.9％,2种对映体的回收率分别为95.1％及98.7％。结论:在该条件下可以成功分离西布曲明对映体,并建立起西布曲明对映体定量分析的毛细管电泳方法。     

西布曲明对映体的毛细管电泳分离及结合常数的测定

目的 采用毛细管电泳法分离西布曲明对映体并测定其结合常数.方法 考察手性添加剂浓度、缓冲溶液pH及浓度、温度、分离电压等因素对分离度的影响,并采用双倒数法计算西布曲明对映体与2,6-二甲基-β-环糊精(DM-β-CD)的结合常数.结果 在12.5 mmol·L~(-1)DM-β-CD、100 mmol·L~(-1)Tris-H_3PO_4(pH 2.5)缓冲液、16℃柱温,30 kV操作电压的毛细管电泳条件下,西布曲明对映体在9 min内获得了良好分离,分离度达2.0;结合常数分别为154.4、173.3 L·mol~(-1).结论 所用高效毛细管电泳方法快速、准确、可靠,适用于西布曲明对映体的分离;结合常数的计算可为研究西布曲明对映体的拆分机理提供依据.     

盐酸坦洛新的手性分离与纯度检查

目的:建立手性分离盐酸坦洛新的高效液相色谱方法和毛细管电泳法,并检查光学纯度。方法:采用 Chiral OD-R 手性色谱柱(250 mm×4.6 mm,5μm),以0.5 mol·L~(-1)高氯酸钠缓冲液(用高氯酸调 pH 2.0)-乙腈(68:32)为流动相;流速0.5 mL·min~(-1);检测波长:210 nm;柱温:30℃;样品浓度0.1 mg·mL~(-1),进样10 μL。采用未涂层石英毛细管(67 cm×50μm,有效长度60 cm),以10 mmol·L~(-1)磷酸盐缓冲液(pH 7.0,内含16 mmol·L~(-1)β-环糊精硫酸钠盐)为缓冲液;检测波长为214 nm;阳极压力进样2 s;电压为27 kV;温度为25℃。结果:HPLC 法和 HPCE 法均基线分离盐酸坦洛新的2个对映体;其最低检测限分别为0.1%和0.3%;2种方法光学纯度测定结果基本一致。结论:建立的高效液相色谱法和毛细管电泳法均可用于该新药的质量控制和稳定性研究。     

盐酸肾上腺素注射液中S-对映体的测定及稳定性考察

目的:建立肾上腺素对映异构体中S-对映体的高效毛细管电泳检测方法。方法:采用未涂层熔融石英毛细管(50μm×42 cm,有效长度32 cm),以含13 mmol·L-1DM-β-CD pH 2.5的缓冲体系(含0.10 mol·L-1磷酸和0.07 mol·L-1三乙胺)为背景电解质溶液,在20 kV分离电压下,于214 nm波长处测定S-对映体。结果:肾上腺素R-对映体和S-对映体浓度分别在0.0026～0.1036 mg·mL-1范围内线性关系良好,相关系数分别为0.9995和0.9999(n=6);定量限分别为0.3和0.4μg·mL-1(S/N≥10),检测限分别为0.1μg·mL-1(S/N≥3)。结论:本方法灵敏度高,重复性好,可用于盐酸肾上腺素注射液中S-对映体的测定及稳定性研究。     

高效毛细管电泳法测定育亨宾树皮中育亨宾的含量

目的建立高效毛细管电泳(HPCE)测定育亨宾树皮中育亨宾含量的方法。方法运用高效毛细管电泳方法,熔融石英毛细管(75μmID×50cm),缓冲液为20mmol·L-1磷酸盐缓冲液(PH=3.0),检测波长:270nm,分离电压:15kV,柱温25℃,用0.45μm微孔滤膜过滤后进样,压力进样:50mbar×5s。结果方法最低检测浓度为0.1μg·mL-1,线性范围1～200μg·mL-1,r=0.9991,线性关系良好。精密度RSD为1.3%,回收率为98.4%。结论本法简单、灵敏经济,可作为育亨宾树皮中育亨宾的含量的测定。     

毛细管区带电泳法分离盐酸美沙酮对映体

目的:采用毛细管区带电泳法对盐酸美沙酮对映体进行了拆分。方法:比较了3种衍生化β-环糊精为手性添加剂的分离效果,对缓冲液的pH及浓度、手性添加剂的浓度、柱温、分离电压等方面进行了考察及优化。结果:确定采用75μm×75 cm未凃渍石英玻璃管柱,运行缓冲液为含50 mmol.L-1的Tris和10 mmol.L-1的HP-β-环糊精的水溶液(以磷酸调节pH至2.0),分离电压为25 kV,柱温25℃,检测波长为205 nm,结论:该方法简便、快速,在15 min内分离度可达到1.9。     

高效毛细管电泳法测定牛乳铁蛋白的含量

目的:采用高效毛细管电泳法(HPCE)的毛细管区带电泳模式(CZE)分离测定牛乳铁蛋白(BLF)的含量.方法:熔融石英毛细管柱67 cm(有效长度55 cm)×50μm;运行缓冲液为33 mmol·L-1磷酸二氢钾-10 mmol·L-1磷酸溶液(pH 2.5);压力进样6.9 kPa × 5 s;运行电压25 kV;检测波长214 nm;毛细管柱温为25℃.结果:乳铁蛋白进样浓度在100.0～600.0 mg·L-1范围内线性关系良好(r=0.999 5),最低检测限为25 mg·L-1.结论:采用HPCE测定乳铁蛋白及杂蛋白的方法简便,结果可靠.     

毛细管电泳法分离盐酸地匹福林对映体

目的:建立一种利用毛细管电泳拆分盐酸地匹福林对映体的方法。方法:采用毛细管区带电泳模式,以羟丙基-β-环糊精(HP-β-CD)为手性选择剂,HP-β-CD最佳浓度为12 g.L-1,磷酸盐为缓冲溶液(pH5.5)、柱温为20℃、分离电压20 kV,检测波长为200 nm。结果:在上述的优化条件下盐酸地匹福林对映体在8 min内达到了基线分离。结论:采用毛细管电泳法分离盐酸地匹福林对映体,方法操作简便、快捷、有效,可用于该药物的质量控制。     

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.     

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.