左氧氟沙星制备方法的改进研究

目的:改进左氧氟沙星的制备工艺。方法:用DMF作溶剂,以三乙胺为催化剂,左氧氟羧酸与N-甲基哌嗪缩合制备左氧氟沙星。结果:制得左氧氟沙星的纯度稳定在99%以上,且目标产物经核磁共振、IR及MS确认结构。结论:本工艺改进了反应条件,减少了环境污染,降低了成本,具有更高的经济效益和市场竞争力。     

左氧氟沙星合成工艺改进研究

对左氧氟沙星的工艺进行了优化,以(2,3,4,5)-四氟苯甲酰氯为起始原料,经酰化,胺化,环合制得左氧氟环合酯,然后用无水哌嗪与左氧氟环合酯缩合,经硫酸二甲酯甲基化后水解精制得左氧氟沙星。与原工艺相比,用无水哌嗪代替N-甲基哌嗪,提高了产品的收率和质量,降低了成本,减少了环境污染,技术指标符合CP2010左氧氟沙星要求。     

旋光-紫外分析法测定盐酸左氧氟沙星滴眼液中左氧氟沙星的含量

选择旋光分析法测定盐酸左氧氟沙星滴眼液中左氧氟沙星的含量,利用紫外-可见分光光度法测定其氧氟沙星的总量,从而建立起氧氟沙星左旋体含量测定的新方法,打破氧氟沙星左旋体含量的传统测量方法-高效液相色谱法,为该类滴眼液的质量标准和控制方法提供了实验依据。左氧氟沙星在1～10 mg/mL范围内线性关系良好（r=0.9867,n=6）,加样回收率在120%左右,结果表明,盐酸左氧氟沙星滴眼液中左氧氟沙星的含量范围为100.9%～103.9%。该方法灵敏、准确、重现性好,结果令人满意。     

树状大分子与乳酸左氧氟沙星的相互作用研究

通过发散法合成出1.0~3.0 G聚酰胺—胺型树枝状高分子(PAMAM),利用氨基与醛的脱水缩合反应,用水杨醛修饰树状高分子合成出PAMAM-水杨醛席夫碱(PAMAM-SA),并采用荧光光谱法以中性磷酸盐缓冲溶液为介质,研究不同代数PAMAM及PAMAM-SA与乳酸左氧氟沙星的相互作用。结果表明:不同代数的PAMAM-SA都能引起乳酸左氧氟沙星(LFL)荧光强度降低,且PAMAM-SA对乳酸左氧氟沙星的猝灭属静态猝灭。与修饰前的PAMAM比较,经水杨醛修饰的PAMAM的树状大分子与乳酸左氧氟沙星的相互作用均表现出较强的相互作用。     

稳定同位素标记物D_3-左氧氟沙星的合成及表征

以市售的左氧氟沙星羧酸为原料,以氘代甲醇为稳定同位素标记物前体,经无水哌嗪取代、双氘代甲基化、氢氧化钠水解合成出稳定同位素标记的D_3-左氧氟沙星,3步反应总收率为45.5%。目标产物经MS、~1HNMR表征确认,通过高效液相色谱确认化学纯度98%,经计算同位素丰度为97.7%。该合成路线具有操作简便、试剂廉价等优点。     

甲磺酸帕珠沙星的合成

以左氧氟沙星中间体(S)-9,10-二氟-3-甲基-7-氧代-2,3-二氢-7-H吡啶[1,2,3-de][1,4]苯并噁嗪-6-羧酸乙酯为起始原料,经与氰乙酸乙酯进行亲核取代反应、水解脱羧、环合、水解、Hoffman降解,与甲磺酸成盐得甲磺酸帕珠沙星,总收率为38%,产品纯度符合药用标准。     

甲磺酸帕珠沙星的合成工艺改进

以左氧氟沙星的中间体--(S)-9,10-二氟-3-甲基-7-氧代-2,3-二氢-7H-吡啶[1,2,3-de][1,4]苯并噁嗪-6-羧酸乙酯为起始原料,经过与氰乙酸乙酯缩合、水解脱羧、1,2-二溴乙烷环合、水解、霍夫曼降解、成盐得到喹诺酮类抗菌药甲磺酸帕珠沙星.总收率达到43.8%,并对目标产物,进行了元素分析,IR,1H NMR,13C NMR,MS等确认.与文献报道相比,该合成工艺路线具有反应条件温和,收率较高,适合工业化生产.     

"一锅法"合成左氧氟沙星

以左氧氟环合酯为原料,水解后直接与N-甲基哌嗪缩合反应,"一锅法"合成左氧氟沙星.该合成方法产品收率高、三废少、生产效率高,符合绿色化学理念.     

金属改性MCM-41对盐酸左氧氟沙星吸附研究

实验制备MCM-41及金属改性Al-MCM-41和Co-MCM-41,并作为吸附剂来处理废水中的盐酸左氧氟沙星.实验对吸附剂反应温度、pH、吸附剂投加量对废水中盐酸左氧氟沙星的吸附效率的影响进行了研究.根据实验结果,设计一款有效吸附废水中的盐酸左氧氟沙星吸附装置,该装置有望于应用于实际生产中,从而简化处理抗生素盐酸左氧...     

左氧氟沙星竞争白热化

<正>左氧氟沙星由于抗菌作用优于母体药物氧氟沙星(泰利必妥)及其他沙星类药物,上市至今深受临床医学界欢迎。2015-2016年,国外媒体评选出的"10只世界上最受欢迎的抗菌药品"中,左氧氟沙星制剂占据2个名额,即第一名Levaquin和第六名Cravit。过去十几年里,左氧氟沙星在国内的产销数量增长迅速,这是因为我国药企仿制氧氟沙星及左氧氟沙星原料药/制剂是在"药品专利法"正式实施(即1993年)以前,可自由仿制。1997年底,国内获批生产左氧氟沙星的原料药厂多达     

Sapindaceae,cyanolipids, and bugs

Scentless plant bugs (Heteroptera: Rhopalidae) are so named because adults of the Serinethinae have vestigial metathoracic scent glands. Serinethines are seed predators of Sapindales, especially Sapindaceae that produce toxic cyanolipids. In two serinethine species whose ranges extend into the southern United States,Jadera haematoloma andJ. sanguinolenta, sequestration of host cyanolipids as glucosides renders these gregarious, aposematic insects unpalatable to a variety of predators. The blood glucoside profile and cyanogenesis ofJadera varies depending on the cyanolipid chemistry of hosts, and adults and larvae fed golden rain tree seeds (Koelreuteria paniculata) excrete the volatile lactone, 4-methyl-2(5H)-furanone, to which they are attracted.Jadera fed balloon vine seeds (Cardiospermum spp.) do not excrete the attractive lactone. Loss of the usual heteropteran defensive glands in serinethines may have coevolved with host specificity on toxic plants, and the orientation ofJadera to a volatile excretory product could be an adaptive response to save time.Mention of a commercial product does not consititute an endorsement by the USDA.     

Insect antifeedant properties of anthranoids from the genusVismia

Vismiones and ferruginins, representatives of a new class of lypophilic anthranoids from the genusVismia were found to inhibit feeding in larvae of species ofSpodoptera, Heliothis, and inLocusta migratoria.     

Direct observation of freeze-thaw instability of latex coatings via high pressure freezing and cryogenic SEM

Despite its industrial importance, the subject of freeze-thaw (F/T) stability of latex coatings has not been studied extensively. There is also a lack of fundamental understanding about the process and the mechanisms through which a coating becomes destabilized. High pressure (2100 bar) freezing fixes the state of water-suspended particles of polymer binder and inorganic pigments without the growth of ice crystals during freezing that produce artifacts in direct imaging scanning electron microscopy (SEM) of fracture surfaces of frozen coatings. We show that by incorporating copolymerizable functional monomers, it is possible to achieve F/T stability in polymer latexes and in low-VOC paints, as judged by the microstructures revealed by the cryogenic SEM technique. Particle coalescence as well as pigment segregation in F/T unstable systems are visualized. In order to achieve F/T stability in paints, latex particles must not flocculate and should provide protection to inorganic pigment and extender particles. Because of the unique capabilities of the cryogenic SEM, we are able to separate the effects of freezing and thawing, and study the influence of the rate of freezing and thawing on F/T stability. Destabilization can be caused by either freezing or thawing. A slow freezing process is more detrimental to F/T stability than a fast freezing process; the latter actually preserves suspension stability during freezing. Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, October 27–29, 2004 in Chicago, IL. Tied for first place in The John A. Gordon Best Paper Competition.     

2008～2009年世界塑料工业进展

收集了2008年7月～2009年6月世界塑料工业的相关资料,介绍了2008～2009年国外塑料工业的发展情况,提供了世界塑料产量、消费量及全球各类树脂的需求量及产能情况。按通用热塑性树脂(聚乙烯、聚丙烯、聚苯乙烯、聚氯乙烯、ABS树脂)、工程塑料(尼龙、聚碳酸酯、聚甲醛、热塑性聚酯、聚苯醚)、特种工程塑料(聚苯硫醚、液晶聚合物、聚醚醚酮)、通用热固性树脂(酚醛、聚氨酯、环氧树脂、不饱和聚酯树脂)不同品种的顺序,对树脂的产量、消费量、供需状况及合成工艺、产品应用开发、树脂品种的延伸及应用的进一步扩展等技术作了详细介绍。     

Ethanol and (−)-α-Pinene: Attractant Kairomones for Bark and Ambrosia Beetles in the Southeastern US

In 2002–2004, we examined the flight responses of 49 species of native and exotic bark and ambrosia beetles (Coleoptera: Scolytidae and Platypodidae) to traps baited with ethanol and/or (−)-α-pinene in the southeastern US. Eight field trials were conducted in mature pine stands in Alabama, Florida, Georgia, North Carolina, and South Carolina. Funnel traps baited with ethanol lures (release rate, about 0.6 g/day at 25–28°C) were attractive to ten species of ambrosia beetles (Ambrosiodmus tachygraphus, Anisandrus sayi, Dryoxylon onoharaensum, Monarthrum mali, Xyleborinus saxesenii, Xyleborus affinis, Xyleborus ferrugineus, Xylosandrus compactus, Xylosandrus crassiusculus, and Xylosandrus germanus) and two species of bark beetles (Cryptocarenus heveae and Hypothenemus sp.). Traps baited with (−)-α-pinene lures (release rate, 2–6 g/day at 25–28°C) were attractive to five bark beetle species (Dendroctonus terebrans, Hylastes porculus, Hylastes salebrosus, Hylastes tenuis, and Ips grandicollis) and one platypodid ambrosia beetle species (Myoplatypus flavicornis). Ethanol enhanced responses of some species (Xyleborus pubescens, H. porculus, H. salebrosus, H. tenuis, and Pityophthorus cariniceps) to traps baited with (−)-α-pinene in some locations. (−)-α-Pinene interrupted the response of some ambrosia beetle species to traps baited with ethanol, but only the response of D. onoharaensum was interrupted consistently at most locations. Of 23 species of ambrosia beetles captured in our field trials, nine were exotic and accounted for 70–97% of total catches of ambrosia beetles. Our results provide support for the continued use of separate traps baited with ethanol alone and ethanol with (−)-α-pinene to detect and monitor common bark and ambrosia beetles from the southeastern region of the US.     

Many Drugs of Abuse May Be Acutely Transformed to Dopamine,Norepinephrine and Epinephrine In Vivo

It is well established that a wide range of drugs of abuse acutely boost the signaling of the sympathetic nervous system and the hypothalamic–pituitary–adrenal (HPA) axis, where norepinephrine and epinephrine are major output molecules. This stimulatory effect is accompanied by such symptoms as elevated heart rate and blood pressure, more rapid breathing, increased body temperature and sweating, and pupillary dilation, as well as the intoxicating or euphoric subjective properties of the drug. While many drugs of abuse are thought to achieve their intoxicating effects by modulating the monoaminergic neurotransmitter systems (i.e., serotonin, norepinephrine, dopamine) by binding to these receptors or otherwise affecting their synaptic signaling, this paper puts forth the hypothesis that many of these drugs are actually acutely converted to catecholamines (dopamine, norepinephrine, epinephrine) in vivo, in addition to transformation to their known metabolites. In this manner, a range of stimulants, opioids, and psychedelics (as well as alcohol) may partially achieve their intoxicating properties, as well as side effects, due to this putative transformation to catecholamines. If this hypothesis is correct, it would alter our understanding of the basic biosynthetic pathways for generating these important signaling molecules, while also modifying our view of the neural substrates underlying substance abuse and dependence, including psychological stress-induced relapse. Importantly, there is a direct way to test the overarching hypothesis: administer (either centrally or peripherally) stable isotope versions of these drugs to model organisms such as rodents (or even to humans) and then use liquid chromatography-mass spectrometry to determine if the labeled drug is converted to labeled catecholamines in brain, blood plasma, or urine samples.