共查询到20条相似文献,搜索用时 62 毫秒
1.
目的:优化米格列醇关键中间体6-(N-羟乙基)-6-脱氧-氨基山梨糖的生物合成工艺。方法:以N-羟乙基葡糖胺作为原料,采用单因素试验方法优化工艺。分别考察了温度、转化时间、静息细胞浓度、底物浓度及起始pH对氧化葡萄糖酸杆菌静息细胞生物催化合成6-脱氧-6-羟乙基氨基山梨糖的影响。结果:在静息细胞浓度10%、底物浓度15%、起始pH 7.0,1000 mL摇瓶装液150 mL,30℃,200 r.min-1条件下振荡转化10 h,底物转化率可达93%。结论:该生物转化工艺切实可行。 相似文献
2.
目的 利用重组α-L-鼠李糖苷酶,以柚皮苷为底物,通过生物转化法制备普鲁宁。方法 以HPLC检测生物转化反应产物,通过DNS法对酶促反应过程进行动态分析,分析酶促反应动力学,优化普鲁宁制备工艺。结果 重组α-L-鼠李糖苷酶水解柚皮苷反应完全后,可得到反应产物普鲁宁和鼠李糖;生物转化法制备普鲁宁的最适反应温度为60 ℃、pH值为4.0、加酶量为12 U·mL-1、底物浓度为2.0 g·L-1,在此最优工艺条件下,94%的柚皮苷转化为普鲁宁;高浓度的Mn2+、Fe2+能够促进柚皮苷转化生成普鲁宁;重组酶对底物亲和力强,酶促反应的米氏常数Km为1.02 μmol·mL-1,Vmax为0.19 μmol·mL-1·min-1。结论 利用重组α-L-鼠李糖苷酶生物转化法制备普鲁宁,转化率高、重现性好、产物易于分离,可为普鲁宁功能研究、开发利用及改性等提供重要依据。 相似文献
3.
目的 通过优化内生放线菌WP-1的发酵条件,提高制霉色基素(funguchromin,FC)的产量。方法 采用单因素试验和正交试验分析不同速效、迟效碳源,不同速效、迟效氮源以及不同无机盐对FC产量的影响,优化放线菌WP-1的培养基组分;采用单因素试验分析不同的培养基初始pH值、培养温度、接种量、装液量、摇床转速对FC产量的影响,优化放线菌WP-1的培养条件。结果 优化后的发酵条件为葡萄糖1%,可溶性淀粉4%,蛋白胨0.5%,花生饼粉9%,MnSO40.000 5%,ZnSO4 0.000 5%,CuSO4 0.000 2%;初始pH 5.5,发酵温度28℃,装液量50 mL培养基/250 mL三角瓶,接种量8%,转速180 r·min-1。在此条件下,FC的产量可达159.0 mg·L-1,与初始发酵条件相比,提高了4.9倍。结论 该方法优化了WP-1产生FC的发酵条件,为下一步规模发酵提供了基础数据。 相似文献
4.
1例43岁女性患者,因感冒口服酚氨咖敏片(1片,tid),第2天停药。用药第5天出现四肢发疹,红斑伴瘙痒明显,用药第7天发展至面部,用药第9天出现高热,实验室检查示白细胞 22.82 × 10-9?L-1,中性粒细胞百分率89.3%, 嗜酸性粒细胞百分率2.7%,丙氨酸氨基转移酶95 U?L-1,门冬氨酸氨基转移酶55 U?L-1,乳酸脱氢酶228 U?L-1,磷酸肌酸激酶27 U?L-1,总胆红素10.2 μmol?L-1,直接胆红素3.4 μmol?L-1,1-3-β-D葡聚糖7.00 pg?ml-1,内毒素5.00 pg?ml-1。考虑为酚氨咖敏片致药物超敏反应综合征。给予注射用甲泼尼龙琥珀酸钠(80 mg,qd)、复方甘草酸苷注射液(100 ml,qd)静脉滴注,依巴斯汀片(10 mg,qd)、盐酸赛庚啶片(2 mg,qd)口服。停药第14天面部、躯干、四肢见暗红斑及色素沉着斑片,皮疹明显消退,白细胞14.95 × 10-9?L-1,中性粒细胞百分率72.0%, 嗜酸性粒细胞百分率1.2%,丙氨酸氨基转移酶44 U?L-1,门冬氨酸氨基转移酶14 U?L-1,乳酸脱氢酶165 U?L-1,磷酸肌酸激酶14 U?L-1,总胆红素9.0 μmol?L-1,直接胆红素1.9 μmol?L-1。停药后6周,皮疹全部消退,皮肤颜色基本正常。 相似文献
5.
6.
7.
西红花苷对牛主动脉平滑肌细胞内钙离子浓度的影响 总被引:4,自引:0,他引:4
目的研究西红花苷对血管平滑肌细胞内钙离子浓度的影响。方法以Fluo-3/AM作为Ca2+荧光探针,采用激光扫描共聚焦显微镜观察牛主动脉平滑肌细胞内钙离子浓度的变化。结果无论细胞外有无钙离子,西红花苷(1×10-8,1×10-7,1×10-6 mol·L-1)均能明显抑制1×10-2 mol·L-1 H2O2引起的细胞内钙离子浓度的升高,其抑制率含钙条件下分别为34.1%, 57.1%和74.3%(P<0.01),无钙条件下分别为26.2%,32.1%和50.0%(P<0.01);在胞外无钙的条件下,西红花苷 (1×10-8,1×10-7,1×10-6 mol·L-1)能抑制70 mmol·L-1 CHCl3导致雷洛丁敏感钙池的释放,其抑制率分别为27.8%, 27.8%和50.0% (P<0.01)。结论西红花苷能抑制胞外钙离子的内流及内质网上钙离子的释放。 相似文献
8.
水和非水毛细管电泳-电导检测法分离测定水杨酸类药物 总被引:9,自引:0,他引:9
目的建立水和非水毛细管电泳-电导法分离水杨酸类药物。方法用未涂层石英毛细管柱(55 cm×50 μm),以10 mmol·L-1 Tris-30 mmol·L-1 H3BO3(pH 8.0)为运行缓冲液,分离电压为24 kV,进样时间10 s,电导检测法。结果在非水实验条件下,水杨酸(SA)、乙酰水杨酸(ASA)和磺基水杨酸(SSA)得到很好的分离。SA,ASA和SSA的线性范围分别为0.05~100 mg·L-1,5.0~250 mg·L-1,0.08~100 mg·L-1,r均大于0.995。结论应用于阿斯匹林制剂中水杨酸和乙酰水杨酸含量的测定,结果令人满意。与水介质相比,乙醇介质具有更高的灵敏度和分离效率。 相似文献
9.
目的探索用固定化氧化葡萄糖酸菌转化6-(N-羟乙基)胺基-6-脱氧-L-山梨呋喃糖的最优条件。方法以海藻酸钠为载体把氧化葡萄糖酸菌固定化,考察固定化细胞在不同转化条件时对底物的转化率。结果通过条件优化,确定固定化细胞转化时间为24 h,底物质量浓度为10 g.L-1,采用的海藻酸钠质量浓度为40g.L-1,菌体包埋量为每g凝胶包埋3.1 g菌体,最适pH为7.0,最适温度为28℃,摇床转速要求高于100r.min-1;用60mmol.L-1的MnCl2替代原转化液中20mmol.L-1的MgSO4;固定化细胞与原游离细胞工艺相比,24h内底物转化率由原来的47%上升到93%,连续转化10次后,转化率仍为38%。结论用固定化氧化葡萄糖酸菌转化6-(N-羟乙基)胺基-6-脱氧-L-山梨呋喃糖,转化率提高46%并能连续转化约10次。 相似文献
10.
大环内酯类抗生素麦迪霉素的电化学特性 总被引:3,自引:0,他引:3
在K2HPO4,NH4Cl+NH3和NaOH的10%(v/v)乙醇水溶液中,除0.01mol·L-1以上NaOH液作为支持电解质外,麦迪霉素的伏安波皆为两个峰。峰A相当于它的甲醛基还原波,峰B为催化吸附氢波。溶液pH对两峰有强烈的影响。实验表明伏安波有吸附特性,且不可逆。两峰的ip与麦迪霉素的浓度成正比,线性范围分别为3×10-6~3×10-5mol·L-1和1×10-7~4×10-5mol·L-1,检测限为:1×10-6mol·L-1和5×10-8mol·L-1。可应用于麦迪霉素的定量测定。研究了两峰的特性和电极机理,测定了有关的物理常数。 相似文献
12.
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.相似文献
13.
14.
Petrikovics I McGuinn WD Sylvester D Yuzapavik P Jiang J Way JL Papahadjopoulos D Hong K Yin R Cheng TC DeFrank JJ 《Drug delivery》2000,7(2):83-89
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. 相似文献
16.
《Critical reviews in toxicology》2013,43(5-6):327-369
AbstractThe 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. 相似文献
17.
《Expert opinion on investigational drugs》2013,22(1):79-86
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. 相似文献
18.
Chang Min Kim Kun Ho Son Sung Hwan Kim Hyun Pyo Kim 《Archives of pharmacal research》1991,14(4):305-310
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. 相似文献
19.
Alberto García-Lled Javier Gmez-Pavn Juan Gonzlez del Castillo Teresa Hernndez-Sampelayo Mari Cruz Martín-Delgado Francisco Javier Martín Snchez Manuel Martínez-Sells Jos María Molero García Santiago Moreno Guilln Fernando Rodríguez-Artalejo Julin Ruiz-Galiana Rafael Cantn Pilar De Lucas Ramos Alejandra García-Botella Emilio Bouza 《Rev Esp Quimioter》2022,35(2):115
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. 相似文献