乙苯/苯乙烯生产过程的优化运行研究

针对乙苯/苯乙烯实际生产装置,分别建立了烷基化、烷基转移、乙苯精馏、乙苯脱氢、苯乙烯精馏生产过程的机理模型,该机理模型与实际生产过程误差范围在2%左右。以该模型为基础进行系统优化操作设计,生产装置实际运行结果表明：基于该优化操作系统,可有效降低装置的能耗,为其他乙苯/苯乙烯装置的优化运行奠定了基础。     

分散深蓝新染料的合成及性能

以2-甲氧基-5-乙酰氨基苯胺为原料,经烷基化、重氮偶合等反应制备了一系列蓝色分散染料。结构式为:式中X为卤素,Y为—NO_2、—CN;R、R_3为—CH_3、—C_2H_5;R_1、R_2为—C_2H_4OH、—C_2H_4OCOCH_3;—C_2H_4CN、—CH_2—■、—CH_2—CH=CH_2。染料的最大吸收波长为580—630 nm;摩尔消光系数为3.46—4.10×10~4(mol/L)~(-1)cm~(-1),溶解度参数19.46—22.18(J~(1/2)/cm~(3/2))。     

叔丁醇治疗SD大鼠硒性白内障的疗效观察

目的:探讨叔丁醇外用滴眼液对SD大鼠硒性白内障模型(模拟老年性白内障)的治疗作用. 方法:建立SD大鼠硒性白内障模型,并将实验大鼠右眼作为药物干预组,左眼作为对照组;用自行配制的叔丁醇外用滴眼液(浓度分别为25、50、75 mmol/L)按时滴眼(1滴/次,3~5次/d);每日进行肉眼观察,并于用药后第5日及第10日用裂隙灯显微镜观察大鼠双眼晶状体核性病变,每日用游标卡尺(最小刻度值0.02 mm)测量大鼠双眼晶状体核性斑块最大直径的改变.另选未建模的SD大鼠,用100 mmol/L的叔丁醇滴眼液滴眼(1滴/次,3~5次/d),观察药物有无毒性及其他不良反应. 结果:硒性白内障大鼠用药眼晶状体核性混浊斑块直径小于对照眼(P<0.01);用药眼核性混浊斑块混浊程度低于对照眼;叔丁醇滴眼液毒性低,刺激性小. 结论:叔丁醇滴眼液对SD大鼠硒性白内障有一定的治疗作用.     

Synthesis of tertiary 14C‐labelled nonylphenol isomers

The ring‐¹⁴C‐labelled p‐nonylphenol (NP) isomers 4(3′,5′‐dimethyl‐3′‐heptyl)‐phenol (p353NP), 4(3′,6′‐dimethyl‐3′‐heptyl)‐phenol (p363NP) and 4(2′,6′‐dimethyl‐2′‐heptyl)‐phenol (p262NP) were synthesized for application in metabolism and sorption studies. Friedel–Crafts alkylation of ¹⁴C‐labelled phenol and the corresponding tertiary nonylalcohol with BF₃ as catalyst was used. After clean‐up of p262NP and p363NP by preparative thin‐layer chromatography radiochemical yields amounted to 62.8 and 64.6%, specific radioactivities were 332 and 88.2 MBq/mmol, and radiochemical purities 97.6 and 99.0%. For both isomers, a large‐scale synthesis with non‐labelled phenol was additionally developed, which led to pure products (96 and 99%, respectively) without further purification steps. In the case of p353NP, which was formed as a diastereomeric mixture, the crude synthetic product had a radiochemical purity of 96.9% (radiochemical yield: 76.0%; specific activity: 298 MBq/mmol); thus, purification was not necessary. All products were characterized by means of gas chromatography‐mass spectroscopy, ¹H‐ and ¹³C‐NMR, as well as IR. Copyright © 2002 John Wiley & Sons, Ltd.     

新型手性相转移催化剂的合成及其应用

合成了两个新型含１,３－亚乙氧基链手性双生铵盐相转移催化剂碘化１,８－双（Ｎ＿苄基－（３８,４Ｓ）－３,４－二羟基四氢吡咯）－３,６－二氧辛烷（ＰＴＣ１）和碘化１,１１－双（Ｎ－苄基（３Ｓ,４Ｓ）－３,４－二羟基四氢吡咯）－５,６,９－三氧十一（ＰＴＣⅡ）,并用于１－（３,４－－亚甲二氧化苯基）２－２丙酮的不对称烃基化反应,合成六个手性苯丙酮衍生物。研究了在手性双季铵盐相转移从化剂ＰＴＣ１存在一,     

Radiosynthesis of 1‐iodo‐2‐[11C]methylpropane and 2‐methyl‐1‐[11C]propanol and its application for alkylation reactions and C―C bond formation

The multitude of biologically active compounds requires the availability of a broad spectrum of radiolabeled synthons for the development of positron emission tomography (PET) tracers. The aim of this study was to synthesize 1‐iodo‐2‐[¹¹C]methylpropane and 2‐methyl‐1‐[¹¹C]propanol and investigate the use of these reagents in further radiosynthesis reactions. 2‐Methyl‐1‐[¹¹C]propanol was obtained with an average radiochemical yield of 46 ± 6% d.c. and used with fluorobenzene as starting material. High conversion rates of 85 ± 4% d.c. could be observed with HPLC, but large precursor amounts (32 mg, 333 μmol) were needed. 1‐Iodo‐2‐[¹¹C]methylpropane was synthesized with a radiochemical yield of 25 ± 7% d.c. and with a radiochemical purity of 78 ± 7% d.c. The labelling agent 1‐iodo‐2‐[¹¹C]methylpropane was coupled to thiophenol, phenol and phenylmagnesium bromide. Average radiochemical conversions of 83% d.c. for thiophenol, 40% d.c. for phenol, and 60% d.c. for phenylmagnesium bromide were obtained. In addition, [¹¹C]2‐methyl‐1‐propyl phenyl sulphide was isolated with a radiochemical yield of 5 ± 1% d.c. and a molar activity of 346 ± 113 GBq/μmol at the end of synthesis. Altogether, the syntheses of 1‐iodo‐2‐[¹¹C]methylpropane and 2‐methyl‐1‐[¹¹C]propanol were achieved and applied as proof of their applicability.     

Alkylated glutamic acid and histidine derived from protein-adducts indicate exposure to sulfur mustard in avian serum

Sulfur mustard (SM, bis[2-chloroethyl]-sulfide) is a banned chemical warfare agent deployed in the violent conflict in the Middle East poisoning humans and animals. For legal reasons, bioanalytical methods are mandatory proving exposure to SM. Reaction products (adducts) of SM with endogenous proteins, for example, serum albumin (SA), are valuable long-lived targets for analysis. Whereas nearly all methods known so far focus on human proteins, we address for the first time neat chicken SA and avian serum from chicken, duck, and ostrich. After proteolysis, protein precipitation, evaporation of the supernatant, and re-dissolution analysis were performed by micro-liquid chromatography-electrospray ionization tandem-mass spectrometry in the selected reaction monitoring mode, μLC-ESI MS/MS (SRM), for detection of the hydroxyethylthioethyl product ion [HETE]⁺ at m/z 105.0. After in vitro incubation with SM and pronase-catalyzed proteolysis, the alkylated amino acids Glu(-HETE) and His(-HETE) were detected. Both borne the SM-characteristic HETE-moiety bound to their side chain. The eightfold deuterated SM analog (d8-SM) was also applied to support adduct identification. Proteolysis conditions were optimized with respect to pH (8.0), temperature (50°C), and time to maximize the yield of Glu(-HETE) (30 min) and His(-HETE) (180 min). Amino acid adducts were stable in the autosampler for at least 24 h. Protein-adducts were stable in serum at −30°C for at least 33 days and for three freeze-and-thaw cycles. At the body temperature of chicken (+40°C), Glu(-HETE) was degraded in serum (period of half-change 3 days), whereas His(-HETE) remained stable. The presented method broadens the toolbox of procedures to document poisoning with SM.     

Fructose-rich niches traced the evolution of lactic acid bacteria toward fructophilic species

Fructophilic lactic acid bacteria (FLAB) are found in fructose-rich habitats associated with flowers, fruits, fermented foods, and the gastrointestinal tract of several insects having a fructose-based diet. FLAB are heterofermentative lactobacilli that prefer fructose instead of glucose as carbon source, although additional electron acceptor substrates (e.g. oxygen) remarkably enhance their growth on glucose. As a newly discovered bacterial group, FLAB are gaining increasing interest. In this review, the ecological context in which these bacteria exist and evolve was resumed. The wide frequency of isolation of FLAB from fructose feeding insects has been deepened to reveal their ecological significance. Genomic, metabolic data, reductive evolution, and niche specialization of the main FLAB species have been discussed. Findings to date acquired are consistent with a metabolic model in which FLAB display a reliance on environmental niches and the degree of host specificity. In light of FLAB proximity to lactic acid bacteria generally considered to be safe, and due to their peculiar metabolic traits, FLAB may be successfully exploited in food and pharmaceutical applications.     

Aag-initiated base excision repair drives alkylation-induced retinal degeneration in mice

Vision loss affects >3 million Americans and many more people worldwide. Although predisposing genes have been identified their link to known environmental factors is unclear. In wild-type animals DNA alkylating agents induce photoreceptor apoptosis and severe retinal degeneration. Alkylation-induced retinal degeneration is totally suppressed in the absence of the DNA repair protein alkyladenine DNA glycosylase (Aag) in both differentiating and postmitotic retinas. Moreover, transgenic expression of Aag activity restores the alkylation sensitivity of photoreceptors in Aag null animals. Aag heterozygotes display an intermediate level of retinal degeneration, demonstrating haploinsufficiency and underscoring that Aag expression confers a dominant retinal degeneration phenotype.     

Improved synthesis and application of [11C]benzyl iodide in positron emission tomography radiotracer production

Positron emission tomography has increased the demand for new carbon‐11 radiolabeled tracers and building blocks. A promising radiolabeling synthon is [¹¹C]benzyl iodide ([¹¹C]BnI), because the benzyl group is a widely present functionality in biologically active compounds. Unfortunately, synthesis of [¹¹C]BnI has received little attention, resulting in limited application. Therefore, we investigated the synthesis in order to significantly improve, automate, and apply it for labeling of the dopamine D₂ antagonist [¹¹C]clebopride as a proof of concept. [¹¹C]BnI was synthesized from [¹¹C]CO₂ via a Grignard reaction and purified prior the reaction with desbenzyl clebopride. According to a one‐pot procedure, [¹¹C]BnI was synthesized in 11 min from [¹¹C]CO₂ with high yield, purity, and specific activity, 52 ± 3% (end of the cyclotron bombardment), 95 ± 3%, and 123 ± 17 GBq/µmol (end of the synthesis), respectively. Changes in the [¹¹C]BnI synthesis are reduced amounts of reagents, a lower temperature in the Grignard reaction, and the introduction of a solid‐phase intermediate purification. [¹¹C]Clebopride was synthesized within 28 min from [¹¹C]CO₂ in an isolated decay‐corrected yield of 11 ± 3% (end of the cyclotron bombardment) with a purity of >98% and specific activity (SA) of 54 ± 4 GBq/µmol (n = 3) at the end of the synthesis. Conversion of [¹¹C]BnI to product was 82 ± 11%. The reliable synthesis of [¹¹C]BnI allows the broad application of this synthon in positron emission tomography radiopharmaceutical development. Copyright © 2015 John Wiley & Sons, Ltd.