地塞米松磷酸钠的流动注射-化学发光分析法的研究

实验了地塞米松磷酸钠在K3Fe（CN）6-鲁米诺、KMnO4-鲁米诺、KIO4-鲁米诺、H2O2-鲁米诺体系中的化学发光现象。结果表明,地塞米松磷酸钠能够显著增强K3Fe（CN）6-鲁米诺体系和KMnO4-鲁米诺体系的化学发光强度,而在另外两个体系中没有增强作用。结合流动注射技术,分别在K3Fe（CN）6-鲁米诺体系和KMnO4-鲁米诺体系中建立了测定地塞米松的新方法。方法的线性范围分别为1.0×10^-7-1.0×10^-5g/mL和6.0×10^-8-1.0×10^-5g/mL,检出限分别为3.0×10^-8g/mL和2.0×10^-8g/mL,相对标准偏差分别为1.6%和1.9%（1.0×10^-6g/mL地塞米松,n=11）。此法已用于针剂和片剂样品的测定,结果与药典方法没有显著性差异。     

流动注射化学发光法测定盐酸美司坦

在碱性介质中,当把鲁米诺和KMnO4的混合溶液注入到盐酸美司坦溶液中时,会产生很强的化学发光现象。由此结合流动注射技术,建立了测定盐酸美司坦的流动注射化学发光新方法。该法的线性范围为2.0×10^-7-8.0×10^-6g/mL,检出限（3σ）为9×10^-8g/mL,对2.0×10^-6g/mL盐酸美司坦样品连续进行11次平行测定,其RSD为0.74%。已用于盐酸美司坦片剂中盐酸美司坦的测定。     

电化学法研究橙黄Ⅳ和溶菌酶的相互作用

在pH 11.00的NH3-NH4Cl缓冲溶液中,橙黄Ⅳ与溶菌酶能形成一种橙黄色的超分子复合物。用线性扫描二阶导数极谱法对该体系进行了研究,复合物的形成使橙黄Ⅳ的还原峰电位不变,峰电流下降,并且该峰电流的下降值同所加的溶菌酶的浓度在一定范围内呈线性关系。用于溶菌酶的测定,在1.6×10^-9-1.0×10^-8mol/L,1.0×10^-8-8.0×10^-8mol/L,9.0×10^-8-1.6×10^-7mol/L三段范围内呈线性关系,检出限为4.0×10^-10mol/L,进而对模拟样品进行分析,并对结合反应机理进行初步的探讨。     

吐温-40-高碘酸钾-过氧化氢化学发光体系测定中药五倍子中的单宁酸

基于单宁酸对过氧化氢和高碘酸钾溶液在温温-40存在下化学发光反应的增敏作用,结合流动注射技术,建立测定痕量单宁酸化学发光的方法,测定单宁酸的线性范围为5．0×10^-8～1．0×10^-5mol·L^-1;检出限为2．3×10^-1mol·L^-1;对于5.0×10^-6mol·L^-1单宁酸进行11次平行测定,其相对标准偏差为2．6％。对化学发光反应的机理也作了初步探讨。     

高锰酸钾-甲醛-巯嘌呤化学发光体系的研究

在酸性条件下,甲醛与高锰酸钾能够产生较弱的化学发光,而巯嘌呤的存在能够大大地增强该化学发光强度。在一定浓度范围内,增加的发光强度与巯嘌呤的浓度呈良好的线性关系,由此建立了一种测定巯嘌呤的流动注射化学发光方法。方法的检出限为8.7×10-9 g/mL,线性范围为1.0×10-8~1.0×10-6 g/mL,相对标准偏差为3.1%(c=5.0×10-7 g/mL,n=11)。     

流动注射化学发光抑制法测定吡罗昔康

基于吖啶橙在氢氧化钠介质中能被高锰酸钾氧化产生较强的化学发光,吡罗昔康能强烈抑制其化学发光,建立了高锰酸钾-吖啶橙-吡罗昔康化学发光抑制测定吡罗昔康的新方法。吡罗昔康在1.0×10-5~7.0×10-4g/mL范围内与化学发光强度呈良好线性关系,方法的检出限为4.5×10-6g/mL,对1.0×10-5g/mL吡罗昔康连续进行6次测定的相对标准偏差为3.6%。     

流动注射-化学发光方法测定盐酸萘甲唑林和盐酸氧甲唑林

H2SO4酸性条件下,甲醛对KMnO4-盐酸萘甲唑林(盐酸氧甲唑林)化学发光体系有较强的增敏作用,且强度与药物浓度呈良好的线性关系.据此,建立了采用KMnO4-甲醛体系测定制剂中盐酸萘甲唑林(盐酸氧甲唑林)的流动注射-化学发光分析法.在优化的实验条件下,盐酸萘甲唑林在1.0×10-8～7.0×10-6g/mL范围内呈良好的线性关系,检出限为8.69×10-9g/mL;盐酸氧甲唑林在5.0×10-8～1.0×10-5范围内呈线性关系,检出限为3.47×10-8g/mL.对浓度为1.0×10-6g/mL的盐酸萘甲唑林和盐酸氧甲唑林分别进行的11次平行测定,RSD分别为4.0%和4.1%.     

流动注射化学发光法测定黄藤素

碱性条件下,铁氰化钾氧化鲁米诺产生化学发光,黄藤素对该体系的化学发光信号具有显著的增强作用。基于此,建立了一种直接测定黄藤素的流动注射化学发光分析新方法。该方法的线性范围为6.0×10-10－3.0×10^-8mol／L（r=0.9956）和3.0×10^-8－3.0×10^-6mol／L（r=0.9981）,检出限为2.5×10^-10mol／L（3σ）。对1.0×10^-9mol／L和1.0×10^-7mol／L的黄藤素连续平行测定11次,其相对标准偏差分别为3.5％和0.73％。该方法用于药物和体液中黄藤素的分析,回收率在96％-102％之间。     

毛细管电泳电化学发光法测定盐酸帕罗西汀的研究

实验发现盐酸帕罗西汀能增强钌联吡啶的电化学发光信号,据此建立了一种盐酸帕罗西汀的毛细管电泳-电化学发光测定新方法。在实验中,分别对毛细管电泳分离条件和电化学发光检测条件进行了优化。在优化的实验条件下,盐酸帕罗西汀检出限为3.45×10^-8g/mL（S/N=3）,线性范围为3.0×10^-7-1.0×10^-4g/mL。通过对1.0×10^-5g/mL的盐酸帕罗西汀进行11次平行测定,峰高的RSD为2.5%。已用于盐酸帕罗西汀片剂的测定。     

米托蒽醌分子印迹聚邻氨基酚敏感膜传感器的研制

在弱酸性条件下,在金电极上以邻氨基酚为单体和交联剂,米托蒽醌为模板分子,用循环伏安法电聚合成米托蒽醌分子印迹聚邻氨基酚敏感膜传感器。该传感器对米托蒽醌具有良好的选择性和敏感度,米托蒽醌浓度分别在2.0×10^-7—1.0×10^-5mol／L及1.0×10^-5—5.0×10^-5mol／L范围内与峰电流减小量呈线性关系,检出限为1.2×10^-7mol／L。本文同时对分子印迹膜的结构和性能进行了探讨与研究。     

Crystal structures of AgAF6 (A = P, As, Sb, Nb, Ta) at ambient temperatures

Structures of AgAF₆ (A=Sb, Ta) have been determined by X-ray single crystal studies at ambient temperatures. AgSbF₆ crystallizes in space group Ia with a=979.85(4) pm, V=9.4076(12)×10⁸ pm³, z=8, and AgTaF₆ crystallizes in space group P4₂/mcm with a=499.49(4) pm, c=960.51(8) pm, V=2.3964(6)×10⁸ pm³, z=2. Only the crystal system and cell parameters were obtained for the isomorphic AgNbF₆; primitive tetragonal, a=497.80(10) pm, b=960.40(10) pm, V=2.3799(12)×10⁸ pm³, z=2. The results of the Raman spectroscopy of AgAF₆ support the obtained structures. The structures are discussed by comparing with that of AgPF₆ and AgAsF₆ which have recently been determined in a series of our study.     

Study on the synthesis of 6-alkylaminouridines via the nucleophilic aromatic substitution reaction of 6-cyanouridine derivatives

6-Cyanouracil derivatives underwent direct substitution reactions with selective primary amines in the presence of N,N-dimethylaminopyridine as a catalyst to give the corresponding 6-alkylaminouracils. This reaction provides a facile access to versatile 6-alkylaminouridine derivatives.     

6,7-二氢-5H-1-氮茚的合成研究

以价廉易得的己二酸二甲酯为原料, 在甲醇钠的催化下, 通过Dieckmann缩合反应得到2-氧代环戊烷羧酸甲酯, 收率82.2%; 2-氧代环戊烷羧酸甲酯再与丙烯腈在40%(质量比)苄基三甲基氢氧化铵甲醇溶液存在下, 经Michael加成制得1-(2-氰乙基)-2-氧代环戊烷羧酸甲酯, 收率82.5%; 进一步酸性脱羧得到3-(2-氧代环戊基)丙腈, 收率84.0%; 将脱羧产物通入装有Ni-Cu/γ-Al2O3催化剂的固定床反应器中, 催化环合最终得到6,7-二氢-5H-1-氮茚, 反应总收率33.8%.     

NEW 6-ETHOXYQUINOLINES AS SIMPLE OPTOQUINE ANALOGUES

ABSTRACT

Reaction of 6-ethoxylepidine (6-ethoxy-4-methylquinoline) with strong base and electrophiles leads to new derivatives, as possible optoquine analogues.     

Synthesis of some sulfonamide derivatives with potential antibacterial activity

Some new quinoxaline-6-sulfonamide and phthalazine-6-sulfonamide derivatives were synthesized. The majority of the prepared compounds showed antibacterial activity.Faculty of Pharmacy, University of Tanta, Egypt. Fax: 002 040 335466Published in Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 523–528, April, 2000.     

Synthesis and Diazotization of Diethyl 6-Amino-2-Hydroxyazulene-1,3-Dicarboxylate and Its 2-Acetoxyl Derivative

Diethyl 6-amino-2-hydroxyazulene-1,3-dicarboxylate ( 6a ) and 2-acetoxyl derivative ( 6b ) were synthesized by reduction of the 6-azido derivatives ( 5a,b ) with zinc/acetic acid in excellent yields. 5a and 5b were prepared by azidation of diethyl 2-acetoxy-6-bromoazulene-1,3-dicarboxylate (4). Diazotization of 6a with sodium nitrite in the presence of concentrated sulfuric acid in dioxane gave diethyl 2-hydroxy- ( 7a ), 2,6-dihydroxy- ( 8a ), and 2-hydroxy-6-[2-(2-hydroxyethoxy)ethoxy]-azulene-1,3-dicarboxylates ( 9a ), in 5, 35 and 20% yields, respectively. Similar reaction of 6b gave the corresponding acetates 7b, 8b , and 9b , compounds of the same type from 6a . No evidence for the formation of 6-diazo-1,3-diethoxycarbonyl-2(6H) azulenone ( 2b ) was obtained in the employed reaction conditions.     

RNA表观遗传修饰——N~6-甲基腺嘌呤与植物的生长发育

RNA表观遗传修饰N~6-甲基腺嘌呤(m~6A)是真核生物信使RNA(mRNA)上存在的最为广泛的中间化学修饰。它在哺乳动物中存在较为广泛,证实m~6A为mRNA上的动态可逆化修饰,它由甲基转移酶复合物(编码器)催化形成,同时可以被去甲基酶(消码器)氧化去甲基;m~6A可以被结合蛋白(读码器)识别,进而调控mRNA的剪接、稳定性、翻译、出核等。相较之下,m~6A在植物中的研究较少。本文将简要回顾目前m~6A的研究进展,重点综述m~6A在植物中的研究结果,展望m~6A在植物生长发育和应对外界刺激时的潜在重要功能。     

Rational design of first generation inhibitors for trehalose 6-phosphate phosphatases

In this study, trehalose 6-phosphate phosphatase (T6PP) was targeted for inhibitor development. T6PP catalyzes the hydrolysis of trehalose-6-phosphate to form trehalose and inorganic phosphate, a reaction essential to important fungal, bacterial, and nematodal pathogens. At the current time, there are no specific inhibitors of T6PP available to serve as tools for interrogating its structure and function nor as leads for pharmaceutical applications. Herein, we describe the synthesis of non-hydrolysable mimics of trehalose-6-phosphate, which incorporate 6-sulfate (1), -phosphonate (2), -fluorophosphonate (3) and –boronate (4) groups in place of the 6-phosphate moiety of the substrate. The inhibitory efficacies of these adducts were evaluated against trehalose 6-phosphate phosphatases selected from evolutionarily distant pathogenic bacteria and nematodes. Phosphonates 2 and 3 were found to display good inhibitory activities against the T6PPs, while the sulfate analog, trehalose-6-sulfate, proved to be a particularly effective broad-spectrum inhibitor of these phosphatases and an ideal prototype for optimization.     

Syntheses and transformations of novel nitrogen and sulfur containing morphinanedienes

Summary The synthesis of 6-azido-6-demethoxythebaine (10) has been performed starting from thebaine (1). Compound10 undergoes a cycloaddition reaction with the azadienophilePTAD to form bridgehead azide14. The acid catalyzed rearrangement of isothiocyanato diene11 obtained from azido diene10 and thiocyanato dienes8 and9 leads to sulfur containing derivatives of apocodeine (17–20).

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Darstellung und Reaktionen stickstoff- und schwefelhaltiger Morphinandiene

Zusammenfassung 6-Azido-6-demethoxythebain (10) wurde ausgehend von Thebain (1) hergestellt. Verbindung10 wurde in einer Cycloadditionsreaktion mit dem AzadienophilPTAD zum Brückenkopfazid14 umgesetzt. Das aus dem Azidodien10 erhältliche Isothiocyanatodien11 und die bereits früher gewonnenen Thiocyanatodiene8 und9 liefern bei säurekatalysierter Umlagerung die Apokodeinderivate17–20.

     

YbB6的能带结构和光电导率谱的解析

用密度泛函（GGA＋U）方法研究YbB6晶体的电子结构。采用FLAPW方法进行计算,获得了比较精确的能带结构信息。分析了YbB6能带结构的特征与Yb-B6簇间成键情况的联系。在此基础上计算YbB6的反射率、介电函数、光电导率和能量损失函数等光学常数,结果与实验值符合比较好。对其光电导率（实部）和能量损失函数谱进行详细分析,对谱峰作出指认,阐明了各谱峰与能带间电子跃迁的联系,证实了前人对谱峰所作经验指认的合理部分,补充和纠正了前人经验指认的不足和不准确之处。