硅胶柱层析纯化青蒿素

目的确定硅胶柱层析对超临界CO2萃取所得青蒿素粗品纯化的工艺条件。方法采用薄层层析-硅胶柱层析法考察不同展开剂的层析效果,最优洗脱剂为正己烷-乙醚(80∶20);以青蒿素回收率和平均含量为评价指标,考察了流速、进样量与层析柱再生条件对层析分离的影响。结果硅胶柱层析纯化青蒿素的最佳操作条件为洗脱剂空塔流速0.5cm.min-1,进样量18.9mg.ml-1柱体积,甲醇再生2倍床层体积。青蒿素含量可由原来的15%提高到70%以上,回收率达90%。经过重结晶精制,产品中青蒿素含量超过99.5%。结论硅胶柱层析纯化青蒿素所得产品符合质量要求。     

吡柔比星的分离与纯化

目的确定用硅胶柱层析纯化吡柔比星粗品的工艺条件。方法采用薄层层析-硅胶柱层析法考察不同展开剂的层析效果,最优洗脱剂为二氯甲烷-甲醇;以吡柔比星的回收率和平均含量为评价指标,考察了流速、进样量与层析柱再生条件对层析粗分和精分的影响。结果硅胶柱层析粗分吡柔比星的最佳工艺条件:以梯度洗脱方式洗脱,洗脱剂流速5.0mL.min-1,上样量16.6mg.mL-1柱体积,0.5g.L-1氢氧化钠溶液离线再生硅胶。吡柔比星质量分数经粗分后由原来的35.7%提高到90%左右,回收率为96.2%。硅胶柱层析精分吡柔比星的最佳工艺条件为洗脱剂二氯甲烷-甲醇比例为90∶10,流速3.5mL.min-1,上样量16.6mg.mL-1柱体积,甲醇再生3倍柱体积。吡柔比星质量分数经精分后由粗分的90%提高到99.6%左右,回收率为97.5%。结论硅胶柱层析纯化吡柔比星所得产品符合质量要求。     

离子交换法分离纯化酶反应液中5-氟尿苷的研究

为开发从酶反应液中分离纯化5-氟尿苷的方法,研究了利用阴离子交换树脂以及硅胶柱色谱实现转化产物分离纯化的工艺;实验采用HPLC为检测方法,以5-氟尿苷含量为考察指标,从吸附量,洗脱率,回收率的角度考察了各种条件的影响。最终确定以D301树脂为吸附剂;最佳吸附条件为动态吸附,温度25℃,pH 8;动态洗脱,洗脱剂5%NaCl溶液,体积流量为3BV/h;再利用硅胶柱色谱,采用200～300目硅胶,以正己烷∶乙酸乙酯=12∶88作为洗脱剂,洗脱后结晶可得到5-氟尿苷纯品,色谱纯,最终收率72.4%。     

硅胶柱层析法分离纯化表没食子儿茶素没食子酸酯

目的 优化表没食子儿茶素没食子酸酯（EGCG）的分离纯化条件。方法 采用硅胶柱层析法，用氯仿和乙酸乙酯对儿茶素富集物进行萃取富集，考察洗脱条件（洗脱剂的类型、体积分数、pH、流速）及上样量对EGCG分离纯化效果的影响，收集高纯度的EGCG馏分，采用高效液相色谱（HPLC）法对儿茶素单体进行检测。结果 最佳洗脱条件为，儿茶素富集物上样量为0.4 g，以80%乙醇为洗脱剂，在pH 4.0、流速3 mL/min条件下进行洗脱。在此条件下，EGCG得率为81.79%，纯度为91.14%。结论 硅胶柱层析法具有方便、快速、纯化分离效果好等优点，可经济、有效地分离出高纯度EGCG。     

大孔树脂联用硅胶柱色谱法富集制备人工蛹虫草中虫草素的工艺研究

目的优选一种简单快捷分离制备人工蛹虫草中虫草素的工艺。方法首先考察7种不同极性的大孔树脂,优选出最佳吸附树脂,然后对树脂富集虫草素的吸附量、洗脱剂浓度、洗脱体积等工艺进行考察,最后对硅胶柱洗脱剂比例等条件进行考察,优选出最佳的硅胶柱分离洗脱剂。结果根据实验考察数据得出最佳工艺条件:大孔树脂型号为HPD-D,树脂对虫草提取液(0.1 mg/m L)的吸附量为2树脂床体积(2BV),用20%乙醇,洗脱体积为3BV可将虫草素洗脱完全,硅胶柱洗脱剂为乙酸乙酯∶丙酮(2∶1),分离制得虫草素晶体纯度约为93.60%。结论优选出的人工蛹虫草中虫草素的富集分离工艺简单快捷,适用于大规模生产制备虫草素。     

替考拉宁的分离纯化

目的优化替考拉宁纯化工艺,制备纯度高、满足欧洲药典标准的替考拉宁。方法采用大孔树脂吸附、结晶等技术分离替考拉宁,结合二元液相色谱系统,以聚合物微球为载体,对填料的型号和洗脱条件进行优化,最终得到高质量替考拉宁样品。结果 PS30-300微球为最佳纯化介质,洗脱剂为65%甲醇-水,上样量为10mg/mL填料,洗脱流速为1.5～2.0BV/h柱体积时洗脱效果最佳。在此实验条件下产品纯度≥99%,纯化收率≥75%。结论该分离纯化方法简单,快速,易于操作,适于工业化生产。     

硅胶柱层析纯化蓖麻碱

目的:确定硅胶柱层析纯化蓖麻中蓖麻碱的工艺条件。方法:采用薄层层析-硅胶层析,以蓖麻碱回收率与平均含量作为评价指标,考察了洗脱剂、上样量对硅胶层析效果的影响。结果:硅胶柱层析纯化蓖麻碱的最佳操作条件为:最佳洗脱溶剂氯仿-甲醇(12∶1),当上样量为3.0 g时,经硅胶柱层析的蓖麻碱粗粉的纯度可以达到89.3%。结论:该方法稳定可靠,可为蓖麻碱的纯化工艺提供参考。     

层析凝胶DEAE Sepharose Fast Flow分离纯化5’-混合脱氧单核苷酸

目的针对5’-混合脱氧单核苷酸的理化特性,研究利用DEAE Sepharose Fast F low凝胶分离纯化5’-混合脱氧单核苷酸。方法上样缓冲液采用20 mmol/L Tris,pH9.0,上柱量≤7.5mg/mL.gel,上柱流速5mL/m in,洗脱缓冲液采用20 mmol/LTris+0.025mol/L NaC l,pH 9.0,洗脱流速0.5mL/m in。结果实验结果发现dCMP,dAMP,dTMP的收率为95%以上,dGMP的收率为85%以上,所获得的混合脱氧单核苷酸经高效液相色谱检测色谱纯达98%以上。     

层析凝胶DEAE Sepharose Fast Flow分离纯化5’-混合脱氧单核苷酸

目的针对5’-混合脱氧单核苷酸的理化特性,研究利用DEAE Sepharose Fast F low凝胶分离纯化5’-混合脱氧单核苷酸。方法上样缓冲液采用20 mmol/L Tris,pH9.0,上柱量≤7.5mg/mL.gel,上柱流速5mL/m in,洗脱缓冲液采用20 mmol/LTris 0.025mol/L NaC l,pH 9.0,洗脱流速0.5mL/m in。结果实验结果发现dCMP,dAMP,dTMP的收率为95%以上,dGMP的收率为85%以上,所获得的混合脱氧单核苷酸经高效液相色谱检测色谱纯达98%以上。     

ADS系列大孔吸附树脂纯化山楂叶总黄酮工艺研究

目的：研究ADS系列大孔吸附树脂分离纯化山楂叶总黄酮的工艺条件及参数。方法：以树脂对山楂叶总黄酮的吸附量和洗脱率为指标,对ADS系列大孔吸附树脂分离纯化山楂叶总黄酮的工艺条件进行筛选。结果：ADS-8型大孔吸附树脂对山楂叶总黄酮有较好的吸附分离性能,该树脂分离纯化山楂叶总黄酮的最佳工艺条件为：上柱液pH值4.5,上柱液总黄酮含量为1 000 mg/L,以流速3 BV/h上柱,上样量为100 ml（约5 BV）;所用洗脱剂乙醇体积分数为40%,以2BV/h的流速洗脱,洗脱剂用量为150 m l（约7.5 BV）。经过上述工艺纯化后,所得产品总黄酮含量达到80%。结论：ADS-8型大孔吸附树脂适于分离纯化山楂叶总黄酮。     

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.

---

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.     

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.