头孢泊肟酯的研究进展

头孢泊肟酯（CPDX-PR）是日本三共公司开发的第3代口服头孢菌素,1990年在日本首次上市。化学名为（6R,7R）-7-[（2Z）-（2-氨基-4-噻唑基）（甲氧亚氨基）乙酰胺基]-3-（甲氧基甲基）-8-氧代-5硫杂-1-氮杂二环[4．2．0]辛-2-烯2-羧酸1[[（1-甲基乙氧基）羰基]氧基]乙酯,     

头孢去甲噻肟钠(Ceftizoxime Sodium)

异名 Epocelin、Ceftix、Ceftizox 化学名(6R,7R)-7-[(Z)-2-甲氧亚氨基-2-(2-氨基噻唑-4-基)乙酰胺基]-8-氧代-5-硫杂-1-氮杂二环[4.2.0]辛-2-烯-2-羧酸钠     

药品行政保护品种介绍:抗感染药(一)(待续)

头孢地尼 通用名：头孢地尼（cefdinir）。化学名：（-）-（6R，7R）-7-[（Z）-2-（2-氨基-4-噻唑基）-2-肟乙酰氨基]-8-氧代-3-乙烯基-5-硫代-1-氮杂双环[4，2，0]辛-2-烯-2-羧酸。结构式见图1。     

美爱克

[通用名称 ]　cefditorenpivoxil ,头孢妥仑匹酯[化学名称 ]　 ( - ) ( 6R ,7R) 2 ,2 二甲基丙酰氧甲基 7 [(Z) 2 ( 2 氨基 4 噻唑基 ) 2 甲氧基亚氨乙酰氨基 ] 3 [(Z) 2 ( 4 甲基 5 噻唑基 )乙烯基 ] 8 氧代 5 硫杂 1 氮杂二环 [4 ,2 ,0 ]辛 2 烯 2 羧酸酯[理化性状 ]　本品为黄色粉末 ,熔点 12 7～12 9℃ ,[α]2 0D 为 - 4 8.5 (c =0 .5 ,甲醇 ) ,能与盐酸以任意比例混合 ,极易溶于乙醇 ,在水中溶解。[药理作用 ]　本品是第四代头孢菌素类抗菌药物。吸收时 ,在肠管壁代谢成头孢妥仑而发挥抗…     

比特拉韦关键中间体的合成工艺改进

本研究以N-叔丁氧羰基-D-丙氨酸(2)为起始原料,经缩合得N-叔丁氧羰基-D-丙氨肟酸(3),3与环戊二烯经氧化和Diels-Alder反应得[(R)-1-[(1S,4R)-2-氧杂-3-氮杂双环[2.2.1]庚-5-烯-3-基]-1-氧代丙基-2-基]氨基甲酸叔丁酯(4),4经催化氢化得到[(R)-l-[(1S,4...     

去甲氨噻肟头孢菌素(Ceftizoxime)

化学名:(6R,7R)-7-[(Z)-2-(2-氨基-4-噻唑基)-2-甲氧亚氨乙酰氨基]8-氧-5-硫-1-氮杂二环[4,2,0]辛-2-烯-2-羧酸钠,Ceftizoxime曾译3-去甲酰氧甲基氨噻肟头孢菌素。化学式:C_(13)H_(12)N_5NaO_5S_2 分子量:405.38 结构式:     

7β-叔丁氧羰基氨基-3-氯甲基-3-头孢烯-4-羧酸二苯甲酯的合成

7-ACA经水解、氨基保护得到的7β-叔丁氧羰基氨基-3-羟甲基-3-头孢烯-4-羧酸,与二苯基重氮甲烷反应保护羧基得7β-叔丁氧羰基氨基-3-羟甲基-3-头孢烯-4-羧酸二苯甲酯,最后经氯代制得硫酸头孢噻利等的中间体7β-叔丁氧羰基氨基-3-氯甲基-3-头孢烯-4-羧酸二苯甲酯,总收率约29%(以7-ACA计).     

莫西沙星8-二氟甲氧基类似物的合成与体内外抗菌作用

1-环丙基-6，7-二氟-8-甲氧基-1，4-二氢．4-氧代喹啉．3-羧酸乙酯依次经醚键断裂、酯化、二氟甲基醚化得1．环丙基-6，7-二氟-8-二氟甲氧基-1，4-二氢-4-氧代喹啉．3-羧酸乙酯，然后经过螫合、与[1S，6S]-2．叔丁氧羰基．2，8．二氮杂双环[4，3，0]壬烷缩合、最后脱除叔丁氧羰基保护得到1-环丙基．8．二氟甲氧基-7-[（1S，6S）．2，8．二氮杂双环[4，3，0]壬烷．8．基]-6-氟．1，4-二氢-4-氧代喹啉-3-羧酸。目标化合物的结构经核磁共振氢谱和质谱（ESI）所确证，并测定了其体内外抗菌作用，结果表明该化合物优于对照药环丙沙星，与莫西沙星相当或略优，尤其对肺炎链球菌29074的体内活性突出，值得深入评价。     

多尼培南的合成

反式-4-羟基-L-脯氨酸经酯化、保护、还原、SN2取代、Mitsunobu反应、醇解得到（2S,4S）-1-叔丁氧羰基-2-（N-叔丁氧羰基氨磺酰胺基）甲基-4-巯基吡咯烷（7）,收率50.8%.7与（1R,5S,6S）-6-[（1R）-1-羟乙基]-2-二苯氧磷酰氧基-1-甲基-1-碳代-2-青霉烯-3-羧酸对硝基苄酯（8）缩合、脱保护,得到多尼培南,收率50.5%（以7计）.总收率接近26%（以反式-4-羟基-L-脯氨酸计）.     

盐酸头孢替安合成路线图解

头孢替安(cefotiam,1),化学名为(6R,7R)-7-[(2-氨基-4-噻唑基)乙酰胺基]-3-[[1-[2-(二甲胺基)乙基]-1H-四唑-5-基]硫代]甲基]-8-氧代-5-硫代-1-氮杂二环[4.2.0]辛2-烯-2-羧酸,是由日本武田公司研发、1981年首次在日本上市的第二代半合成头孢菌素[1].     

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.     

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.