毛细管电泳法测定发酵液中的扁桃酸对映体含量

目的:采用毛细管电泳法同时测定发酵液中的苯乙酮酸和扁桃酸对映异构体的含量。方法:运行缓冲液为100 mmol·L-1 Tris-磷酸缓冲液(pH 7.6,含150 g·L-1羟丙基-β-环糊精);运行电压20 kV;柱温20℃;检测波长214 nm。结果:扁桃酸样品(0.75 mmol·L-1)的分离度(Rs)可达1.29;线性范围为0.065-1.0 mmol·L-1(r=0.998),最低检测限为0.01mmol·L-1(S/N=3);实际样品的平均回收率为99.2％;2个对映体迁移时间的RSD均小于1.0％,峰面积的RSD均小于3.0％。结论:采用该方法分析生物不对称合成的手性扁桃酸发酵样品,具有准确、经济、快速、简便等特点。     

高效毛细管电泳法研究盐酸司来吉兰的手性分离

目的 :采用高效毛细管电泳法分离盐酸司来吉兰的对映体。方法 :对影响分离的手性选择剂、运行缓冲液等进行了系统的研究。结果 :用含 2 0mmol·L-1羟丙基 - β -环糊精 (HP - β -CD) ,5 0mmol·L-1磷酸盐缓冲液 (pH4 7)作运行缓冲液 ,使盐酸司来吉兰对映体获得基线分离。 结论 :本法可应用于测定盐酸司来吉兰片中左旋异构体含量。     

毛细管电泳法测定红毛五加茎皮中鸟苷的含量

目的建立毛细管区带电泳法测定红毛五加茎皮中鸟苷含量的方法。方法采用毛细管区带电泳法 ,以未涂层的熔融毛细管 (5 8cm× 5 0 μmID ,有效分离长度为 5 0cm)为分离通道 ,运行缓冲液为 40 0mmol·L-1硼酸 5 0mmol·L-1硼砂 1 2 % (φ)乙腈 ,用氢氧化钠调 pH至 8 8;分离电压2 1kV(恒压 ) ;检测波长 2 5 4nm ;毛细管柱温 2 5℃ ;自动压力进样。结果红毛五加茎皮中鸟苷在0 0 1 8～ 0 3 5mmol·L-1内线性关系良好 (r=0 9997) ,鸟苷的加样回收率为 98%～ 1 0 2 % ,RSD为2 3 % (n =3 )。红毛五加茎皮中鸟苷的平均含量为 0 2 4mg·g-1。结论用毛细管区带电泳法测定红毛五加茎皮中鸟苷含量的方法简便、快捷、可行。     

氧氟沙星对映体的毛细管电泳手性分离

用高效毛细管电泳和二极管阵列检测器,以环糊精为拆分试剂对氧氟沙星进行手性分离(最大分离度可达2.18)。发现衍生化环糊精有较好的分离效果,用含DM-β-CD40mmol·L^-1,KH₂PO₄70mmol·L^-1,pH2.5的缓冲液,在25℃电泳,20kV分离电压下得到优化的分离结果。     

混合取代基—β—环糊精—毛细管电泳法分离测定麻黄碱和伪麻黄碱

目的:建立毛细管电泳法同时分离测定同分异构的2对手性化合物麻黄碱和伪麻黄碱的含量。方法:Waters CapillaryIon Analyzer,50μm×60cm空心熔融石英毛细管柱,柱上紫外检测。电泳条件:分离用缓冲液为25mmol·L~(-1)的磷酸-Tris 缓冲液,含18mmol·L~(-1)的羧甲基-β-环糊精和7.5mmol·L~(-1)的β-环糊精-硫酸酯,pH3.02。分离电压:18kV;温度:25℃;虹吸进样,高度10cm,时间1s;紫外检测波长214nm。结果:左旋伪麻黄碱、右旋麻黄碱、左旋麻黄碱和右旋伪麻黄碱线性范围分别为23.7～237μg·ml~(-1),25.0～250μg·mL~(-1),25.0～250μg·mL~(-1),25.4～254μg·mL~(-1),以信噪比等于3:1为标准,最小检测浓度均为5.0μg·mL~(-1);日内和日间精密度RSD在2.4％～4.3％之间。结论:方法分离效率高、简便、快速、成本低。     

高效毛细管电泳法测定地塞米松磷酸钠脂质体中地塞米松磷酸钠的含量

目的:建立高效毛细管电泳法测定地塞米松磷酸钠脂质体中药物含量。方法:毛细管(60 cm×75μm,有效长度53cm);运行缓冲液100 mmol·L-1硼砂(0.1 mol·L-1盐酸调pH 9.2),高压进样5 s,分离电压20 kV,温度为20℃,头孢拉定为内标,检测波长为240 nm。结果:地塞米松磷酸钠在0.78-50 μg·mL-1浓度范围内线性关系良好(r=0.9998),地塞米松磷酸钠的平均回收率为98.5％。结论:本方法准确、简单、快捷,适用于地塞米松磷酸钠脂质体的质量控制。     

左舒必利的毛细管电泳手性分离与纯度检查

目的:建立手性分离方法并检查左舒必利光学纯度。方法:通过手性拆分剂的种类及浓度、缓冲液的pH及浓度、温度及电压的优化,选择最佳的手性分离条件。结果:最佳分离条件缓冲液为100 mmol·L~(-1)磷酸盐缓冲液(用磷酸调pH4．0,内含18 mmol·L~(-1)β-环糊精硫酸钠盐);检测波长为254 nm;电压为15 kV;温度为22℃,基线分离了舒必利2个对映体。结论:建立的毛细管电泳法可用于左舒必利的质量控制和稳定性研究。     

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。     

毛细管电泳高频电导法测定威灵仙中熊果酸的含量

目的:建立以毛细管区带电泳、高频电导法测定威灵仙中熊果酸含量的方法。方法:采用未涂层弹性融硅石英毛细管柱(60cm×75μmID,有效长度56cm),以1.2mmol·L-1三乙胺-HCl(pH10.60)、0.24mmol·L-1β-环糊精为运行缓冲液,分离电压为12.5kV,重力进样10s(高度20cm)。结果:熊果酸检测浓度在5.55～111.0mg·mL-1范围内与对照品同内标峰面积的比值呈良好的线性关系(r=0.9993);平均回收率为96.0%,RSD=1.39%(n=6)。结论:本法简便、准确、快速、重现性好,可用于威灵仙中熊果酸的含量测定。     

毛细管电泳法测定元胡止痛片和元胡止痛口服液中延胡索乙素的含量

目的:建立毛细管区带电泳法测定元胡止痛片和元胡止痛口服液中延胡索乙素的含量。方法:0.2mol·L~(-1)Tris-45mmol·L~(-1)磷酸二氢钠(磷酸调pH 5.30)-40％异丙醇为缓冲液,分离电压为29 kV,检测波长200nm,50cm×50μm,末涂层石英毛细管,每次进样前分别用0.1 mol·L~(-1)的盐酸、氢氧化钠和缓冲液冲洗5 min; 进样方式:压力进样2s。操作温度:25℃。结果:延胡索乙素在0.04～1.60mg·mL~(-1)范围呈线性,RSD小于2.9％,回收率大于97％。结论:实验结果表明,该方法简便、快速、结果准确可靠,有较好的重复性。     

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.     

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.