螺旋霉素发酵液萃取过程工艺研究

研究了螺旋霉素发酵滤液提取过程中的萃取工艺特性，考察了温度、酸度等诸因素对萃取过程和萃取分配系数α的影响。实验发现，萃取过程中的最佳酸度范围在ｐＨ９～１０左右，而且温度影响其分配系数α。在此基础上推导并建立了Ｔ＝５～３５℃，ｐＨ７～１０时萃取分配系数数学模型：α＝７３．５６ｅｘｐ［－ΔＨｍＲ（１Ｔ－１Ｔ０）］／（１＋１０８．４－ｐＨ＋１０１５．５－２ｐＨ）     

螺旋霉素和丙酰螺旋霉素的某些萃取性质的比较研究

研究了溶剂萃取和反萃取丙酰螺旋霉素的有关性质，并与螺旋霉素作了比较。根据螺旋霉素及丙酰螺旋霉素的表观分配常数与ｐＨ的模型式，用高斯牛顿法回归理论分配系数分别为３３．６２和１９．０１，并通过回归首次得到丙酰螺旋霉素的解离常数为７．７６和５．２。通过在磷酸盐缓冲液体系中的反萃取实验得到反萃取的经验模型为Ｋ＋ａ＝ｂ＋ｃ＊ｐＨ，通过计算可知当ｐＨ为３．１５和３．２４时，丙酰螺旋霉素和ＳＰＭ反萃取率达到最大，分别为４８和１０２。另外还研究了温度对萃取和反萃取的影响。根据所得公式可以得到丙酰螺旋霉素的计算诺模图。     

头孢菌素C反应性萃取的初步研究.Ⅱ.萃取工艺条件

通过探讨萃取时间、萃取剂浓度、料液浓度、氯离子浓度、相比、水相ｐＨ值、水相缓冲溶液阴离子、萃取剂阴离子等因素对萃取率的影响规律，提出较好的头孢菌素Ｃ的萃取工艺条件。并且对萃取过程中出现的第３相进行了分析，提出一些消除或减少第３相的措施；对反萃体系的选择和反萃条件的确定也进行了一些探索     

头孢菌素C反应性萃取的初步研究.：II.萃取工艺条件

通过探讨萃取时间、萃取剂浓度、料液浓度、氯离子浓度、相比、水相ｐＨ值、水相缓冲溶液阴离子、萃取剂阴离子等因素对萃取率的影响规律，提出较好的头孢菌素Ｃ的萃取工艺条件。并且对萃取过程中出现的第３相进行了分析，提出一些消除或减少第３相的措施；对反萃体系的选择和反萃条件的确定也进行了一些探索。     

青霉素G间歇反萃取工艺的优越性

萃取与反萃取是青霉素G提纯的重要步骤，选择适合的反萃取工艺对提高收率、保证质量起着决定性作用。本文论证了青霉素G间歇反萃取工艺的优点，并与连续反萃取工艺进行了比较及反萃取液(RK)的质量对结晶阶段影响作了详细论述。结论间歇式反萃取工艺更适合现代的青霉素提炼生产。     

银杏叶提取物中银杏黄酮苷元的提纯工艺研究

目的 从银杏提取物中分离纯化黄酮苷元,寻找分离提纯银杏黄酮苷元的最优条件.方法 对银杏提取物水解液的酸度、水解液的料液比、水解时间、水解液醇度、水解温度、萃取溶剂、萃取条件以及黄酮苷元的结晶进行研究.结果 确定了最佳水解液为醇-盐酸为8∶2、最佳固液比为(g·mL-1)1∶50、水解时间2h、水解温度60℃、萃取溶剂为...     

去甲金霉素提取新工艺研究

研究了去甲金霉素发醇滤液的提取新工艺,并对新萃取体系的萃取和反萃取特性进行了详细研究。新萃取剂的发挥性小,气味小,水溶性小,萃取过程产生的界面物也少,提高了萃取收率,降低了生产成本。可以直接多次复用,省去了回收溶剂和溶煤复用所消耗的大量能量。研究表明,该萃取体系有良好的萃取和反萃取特性。     

反胶束萃取技术及其在抗生素分离上的应用

本文介绍了反胶束概念及萃取分离的基本原理，详细地介绍了反胶束萃取抗生素的国内外研究现状，对反胶束萃取分离抗生素尤其是氨基糖类抗生素提出了新思想。     

利福霉素B的提取工艺研究

从地中海拟无枝酸菌的发酵液中提取利福霉素B的工艺研究。采用萃取→反萃取→二次萃取→结晶的工艺路线．可以得到纯度较高的利福霉素B中间产品。萃取时采用乙酸丁酯为萃取剂；反萃取时采用pH7．5—8．0的磷酸盐缓冲液为反萃剂，进行多级错流萃取，再经二次萃取提纯，通过冷冻结晶即得产品利福霉素B。     

超临界CO2提取香附、当归挥发油的工艺研究

目的确定舒经克痛软胶囊中挥发油成分的提取路线并优化工艺参数。方法采用超临界CO2萃取法，使用正交试验设计方案，以提取率为指标，对萃取温度、萃取压力、分离压力和分离温度等影响因素进行考察。结果萃取压力、分离压力、分离温度对提取率的影响具有显著性意义，萃取温度无显著性意义。采用超临界CO2萃取法萃取舒经克痛软胶囊中挥发油成分的最佳工艺条件为：香附：萃取压力15mPa、萃取温度45℃、分离压力10mPa、分离温度30℃；当归：萃取压力25mPa、萃取温度50℃、分离压力8mPa、分离温度40℃。结论该方法简便，可靠，选择性高，适工业化生产。     

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.