氧氟沙星对映体的高效毛细管电泳法手性拆分

目的 建立氧氟沙星对映体高效毛细管电泳拆分的新方法.方法 以三甲基-β-环糊精(TM-β-CD)作为手性添加剂,tris-H3PO4 作背景电解质,检测波长为 282 nm,对运行缓冲溶液的pH值和浓度、TM-β-CD的浓度、分离电压、有机改性剂等因素对分离的影响进行了考察,并对拆分机制进行了初步探讨.结果 在运行缓冲液为pH2.5的75 mmol/L的tris-H3PO4溶液,30 mmol/L的TM-β-CD,操作电压为 30 kV,柱温为20℃的条件下氧氟沙星对映体达到良好分离,分离度为 3.5.结论 所建立的高效毛细管电泳方法分析时间短,重复性好,灵敏度高,适用于氧氟沙星对映体的分离.     

水／非水介质毛细管电泳法拆分抗胆碱能药物的研究

目的:研究抗胆碱能药物盐酸苯环壬酯、盐酸去甲苯环壬酯和盐酸戊乙奎醚对映体的手性分离方法。方法:采用均匀设计方法建立了拆分3种抗胆碱能药物对映体的水介质毛细管电泳方法。也通过选择环糊精种类和浓度、背景电解质浓度和酸度等最佳试验条件,确定了非水介质毛细管电泳拆分这3种抗胆碱能药物对映体的方法。结果:40 mmol·L~(-1)的磷酸盐缓冲液,pH=2.0,含有5 mmol·L~(-1)HP-β-CD 的甲醇(20%,v/v)水溶液实现了盐酸苯环壬酯和盐酸去甲苯环壬酯的手性分离;20 mmol·L~(-1)磷酸和10 mmol·L~(-1)氢氧化钠的甲醇溶液,添加9 mmol·L~(-1)HDMS-β-CD 作为分离介质,可以同时拆分盐酸苯环壬酯和盐酸去甲苯环壬酯的混合物,并可以较好地分离盐酸戊乙奎醚对映体。结论:比较2种拆分体系表明,非水介质毛细管电泳快速、高效,分离度高。     

坦洛新对映体的HS-β-环糊精的HPCE手性拆分研究

目的:建立坦洛新对映体的毛细管电泳手性拆分法。方法:10 mmol·L~(-1)HS-β-环糊精为手性添加剂,以25 mmol·L~(-1)的磷酸缓冲液,用三乙醇胺调节 pH 为3.0为背景电解质溶液,运行电压为-20 kV,毛细管温度为20℃,检测波长200nm,对坦洛新对映体进行手性分离研究,并考察了多种因素对分离的影响。结果:在该毛细管电泳条件下,坦洛新对映体能得到基线分离。结论:本方法简单、快捷、经济,可适用于坦洛新对映体分离和纯度检查。     

新型活性化合物Ⅱ-f对映体的毛细管电泳手性拆分研究

目的以羧甲基-倍他-环糊精(CM-β-CD)为手性选择剂,建立新型活性化合物Ⅱ-f对映体的毛细管电泳拆分方法,并对其左旋对映体的过量值(e.e.%值)进行测定。方法采用未涂层熔融石英毛细管柱,背景电解质为Tris-H3PO4缓冲溶液。考察了手性选择剂CM-β-CD浓度、pH值、缓冲溶液浓度、工作电压及温度对对映体分离的影响。结果在优化条件下,即20mmol·L-1CM-β-CD、40mmol·L-1Tris-H3PO4(pH4.4,50%甲醇v/v)的运行缓冲液,分离电压20kV,温度20℃,Ⅱ-f两对映体分离度达3.5,标记出峰顺序为右旋体杂质先出峰,左旋Ⅱ-f粗品与精制品样品的e.e.%值测定结果分别为72.50%和100%。结论该法简单快速,可用于Ⅱ-f对映体的质量控制。     

以盐酸去甲万古霉素为手性选择剂毛细管电泳法分离西替利嗪对映体

目的:建立以阳离子表面活性剂碘化四丁基铵为电渗流改性剂,以盐酸去甲万古霉素为手性选择剂的毛细管电泳法分离西替利嗪对映体。方法:考察了盐酸去甲万古霉素浓度、Tris 浓度和缓冲液 pH 对分离的影响,对分离条件进行了优化。结果:在含0.04 g·L~(-1)碘化四丁基铵和1.0 mmol·L~(-1)盐酸去甲万古霉素的25 mmol·L~(-1)Tris 磷酸缓冲液(pH 4.5)的运行电解质体系中,西替利嗪对映体在分离电压为20 kV 的条件下得到良好分离,西替利嗪对映体分离度达1.8。结论:本法可用于西替利嗪对映体的分离。     

羧甲基-β-环糊精作为手性选择剂对毛细管电泳手性拆分西酞普兰的影响

目的 以羧甲基-β-环糊精作为手性选择剂,研究西酞普兰的毛细管电泳手性拆分方法 .方法 选择和优化了手性选择剂的浓度、缓冲溶液的浓度、pH及分离电压等.电泳石英毛细管柱内径为75 μm,总长65 cm,有效长度5 cm;紫外检测波长200 nm;柱温15℃.结果 在含0.25%羧甲基-β-环糊精和25 mmol·L<'-1>磷酸盐(pH7.0)的缓冲溶液中,分离电压为30kV时,西酞普兰对映体达到基线分离,分离度为1.6.结论 所建方法 可以分离分析西酞普兰对映体.     

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。     

毛细管区带电泳法分离盐酸异丙肾上腺素对映体

目的 采用毛细管区带电泳法拆分盐酸异丙肾上腺素对映体. 方法 比较3种衍生化β-环糊精(β-CD)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考察及优化. 结果确定采用75 μm×75 cm未凃渍石英玻璃管柱,运行缓冲液为含50 mmol.L-1的三羟甲基氨基甲烷和40 mmol.L-1的2,6-二甲苯-β-CD的水溶液(采用磷酸调节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、重复性好,在14 min内分离度可达到2.6.     

盐酸西布曲明对映体的手性分离

目的采用高效液相和毛细管电泳建立盐酸西布曲明两对映体的分离方法。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225nm;运行缓冲液为含2%磺化-β-环糊精的20mmol.L-1磷酸二氢钠溶液(pH值为3.5)。结果采用HPLC和HPCE方法均可以分离盐酸西布曲明的两异构体。两个对映体HPLC的分离度为3.1,HPCE的分离度为16.8,HPCE的线性范围为5~300μg.mL-1,检测限为2μg.mL-1。结论在上述条件下能成功分离盐酸西布曲明对映体,毛细管电泳法的分离效果优于高效液相色谱法     

2-甲基-β-环糊精作为手性选择剂对5种药物对映体的毛细管电泳拆分研究

目的以2-甲基-β-环糊精(2-O-methylated-β-cyclodextrin,2-O-M-β-CD)为手性添加剂,利用毛细管电泳法(capillary electrophoresis,CE)对消旋体药物甲溴后马托品、氧氟沙星、酮康唑、利阿唑和卡维地洛进行拆分研究。方法考察了背景电解质溶液的pH值、2-O-M-β-CD浓度、缓冲盐浓度对分离的影响,优化了分离条件。结果在最佳分离条件下,甲溴后马托品、氧氟沙星、酮康唑、利阿唑对映体达到完全分离,分离度分别为3.6、2.8、1.7、1.5;卡维地洛对映体分离度达到1.4。结论所建立的毛细管电泳法适于除卡维地洛外其余4种药物的对映体分离。     

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.     

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.