花菁-脱氧核糖核酸的共振光散射光谱及其分析应用

研究了一种苯并噻唑阳离子花菁与脱氧核糖核酸(DNA)作用的共振光散射光谱,在pH 6.0的六次甲基四胺-HCl缓冲介质中,痕量DNA的加入使花菁在590nm的共振光散射强度显著增强。在最佳实验条件下,增强的共振光散射强度与DNA浓度具有良好的线性关系,据此建立了一种测定DNA的共振光散射光谱法。方法的线性范围为:小牛胸腺DNA(CT DNA),0～20μg/mL,鱼精子DNA(FS DNA),0～15μg/mL;检出限分别为0.005μg/mL和0.008μg/mL。该方法已用于合成样品中DNA的测定。     

同多酸和染料探针共振光散射法测定蛋白质

在酸性条件下,铬黑T、钼酸铵与蛋白质形成聚合物,使体系的共振光散射明显增强。据此建立了利用共振光散射技术测定总蛋白含量的新方法。在最佳条件下,体系的最大散射峰位于555nm处。共振光散射增强的程度与蛋白质的浓度呈良好的线性关系。牛血清白蛋白和人血清白蛋白的线性范围分别为0.20～10.0μg/mL和0.10～8.0μg/mL,检出限为0.050μg/mL和0.039μg/mL。方法已用于人血清样品的分析,并与考马斯亮蓝的测定结果进行了比较,两者无显著性差异。     

铁-金橙G-共振散射光谱法测定水中痕量Fe3+

研究了Fe3+-金橙G(OG)体系的共振光散射光谱,发现Fe3+对OG的共振光散射有增强效应。进一步研究发现,其增强值(△I)与加入Fe3+的质量浓度呈线性关系,对条件进行了优化,并建立了一种测定Fe3+的新方法,方法的线性范围为0.028～1.00μg/mL,检出限为0.009μg/mL,用于水样中痕量Fe3+的测定,结果满意。     

表面活性剂和染料探针共振光散射法测定蛋白质

在pH为2.1的Britton-Robinson缓冲溶液中,蛋白质与十二烷基磺酸钠和吖啶红作用形成聚集体,导致体系产生较大的共振散射光(RLS)强度,并且RLS的增强程度与蛋白质的浓度呈线性关系,据此建立了测定蛋白质含量的方法.人血清白蛋白(HSA)和牛血清白蛋白(BSA)分别在0.03～3.0μg/mL和0.2～7.0μg/mL的浓度范围内与增强的共振光散射强度有良好的线性关系,相应的检测限分别为0.0119μg/mL和0.026μg/mL.对体系的反应机理进行了讨论.将方法用于人血清中蛋白质含量的测定,并将分析结果与考马斯亮蓝法进行了对照.t-检验证明,两种方法无显著性差异.     

Ru（bpy）3^2＋ -DNA体系的共振光散射光谱研究及其分析应用

研究了Ru(bpy)32 与脱氧核糖核酸(DNA)作用的共振光散射光谱。基于DNA对Ru(bpy)32 共振光散射的增强效应,建立了共振光散射法测定DNA的新方法。在最佳实验条件下,Ru(bpy)32 在373nm处的共振光散射增强与DNA的质量浓度呈线性关系,线性范围为0.04~3.2μg/mL,检出限为16ng/mL。应用于合成样品及实际样品中DNA的测定。     

苯唑西林与维多利亚蓝B的共振瑞利散射光谱及应用

在pH 9.54时,苯唑西林的水解产物与维多利亚蓝B形成紫红色的离子缔合物,使体系的共振瑞利散射(RRS)急剧增强并产生新的RRS光谱,在最大散射波长366 nm处,苯唑西林的浓度在0~6.0μg/mL范围内与散射强度(△IRRS)成良好的线性关系,据此建立了测定苯唑西林的共振瑞利散射法,检出限为0.039μg/mL。该方法可用于苯唑西林药物及人体尿液中苯唑西林含量的测定。     

基于与铁氰化钾和Zn~(2+)作用共振光散射法测定异烟肼

在酸性介质中,异烟肼能将铁氰酸根离子还原成亚铁氰酸根离子,后者与硫酸锌反应生成K2Zn3[Fe(CN)6]2粒子引起体系的共振光散射信号显著增强.在345nm处增强的散射信号强度ΔIRLS与异烟肼的浓度在0.01~1.0μg/mL范围内呈线性关系,据此建立了一种检测异烟肼含量的共振光散射(RLS)分析方法.线性回归方程为ΔIRLS=136.1+4239c(c,μg/mL),相关系数(r)为0.9984,检测限(3σ)为3.8ng/mL.该方法已成功用于异烟肼片剂及血清样品的测定.此外,文中还结合吸收光谱,动态光散射,扫描电子显微镜等表征手段对反应机理和RLS信号强度增强的原因进行了探讨.     

光谱法研究二甲酚橙-Cu(Ⅱ)配合物与蛋白质的相互作用

研究了二甲酚橙(XO)-Cu(Ⅱ)配合物与牛血清蛋白(BsA)相互作用的共振散射光谱(RLS)和电子吸收光谱,建立了一种利用金属配合物为探针测定痕量蛋白质的分析方法.在pH 2.50的Britton-Robinson缓冲溶液中,XO-Cu(Ⅱ)与BSA作用后在λ=557 nm处出现一增强的共振散射峰,且增强的RLS强度与蛋白质的浓度呈线性关系.在选定的优化条件下,线性范围为0.18～15μg/mL.线性方程为I(Rts)=46.5+64.8ρ(μg/mL),r=0.998,方法检出限为0.15μg/mL.该方法用于牛尿及牛血样品分析测定.对二甲酚橙-Cu(Ⅱ)配合物与蛋白质的相互作用的研究表明,二甲酚橙-Cu(Ⅱ)配合物与蛋白质之间主要存在的相互作用是静电引力.     

樱桃红共振光散射光谱法测定牛血清白蛋白

研究了以樱桃红为共振光散射探针测定牛血清白蛋白的分析方法。在pH 3.58的BR缓冲溶液中,樱桃红与牛血清白蛋白(BSA)相互作用形成复合物,导致共振光散射(RLS)光谱明显增强,最大RLS峰位于340 nm处。由此建立检测痕量BSA的新方法。在优化实验条件下,RLS强度与BSA浓度的线性范围为1.0～60.0μg/mL,检出限为0.15μg/mL。方法可用于牛尿样品的分析。     

Bi-BSA-钙试剂体系共振光散射光谱法测定铋的研究

基于Bi(Ⅲ)可以对BSA-钙试剂体系的共振光散射产生一定的增强作用,从而建立了测定铋的灵敏的RLS新方法。该方法的线性范围为0.0~12.0μg/mL,检出限为4.5μg/L,对1.0μg/mL的铋标准溶液进行连续9次平等测定,相对标准偏差为1.4%。该方法用于胃药中铋量的测定。     

二氧化碳和丙烯直接合成甲基丙烯酸的NiPMo/TiO2催化剂的研究

用溶胶-凝胶法以磷钼酸(MPA)的镍盐溶液水解钛酸四丁酯制备了NiPMo/TiO2催化剂.使用ICP、 XRD、 TG-DTA、 IR、 TPD-MS和微反应技术研究了催化剂的化学组成、热稳定性、化学吸附性质和催化反应性能.杂多钼酸盐与TiO2通过O2-在TiO2表面发生了键合.在623 K下,杂多阴离子仍保持原有的Keggin结构.CO2在Lewis酸位Ni(Ⅱ)和Lewis碱位Ni-O-Mo的桥氧协同作用下生成CO2卧式吸附态Ni(Ⅱ)←O-(CO)←(O--Ni).丙烯有多种吸附态在催化剂上吸附.在563 K、 1 MPa和空速1500 h-1的反应条件下,丙烯的摩尔转化率为3.2%,产物MAA选择性为95%.     

Synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives

Different approaches for the synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives from simple amino acids have been investigated. A library of 33 precursors for the preparation of N-hydroxy pyrazinones was obtained in moderate to good yields.     

Toward new camptothecins. Part 6: Synthesis of crucial ketones and their use in Friedländer reaction

In the context of the preparation of camptothecin and luotonin A analogs, the synthesis of some key keto-precursors and their use in Friedländer condensation are described. This paper also focuses on the stability of these keto intermediates and emphasizes the major differences between indolizinones and pyrroloquinazolinones series. Noteworthy is also the report of some original structures isolated as by-products of some experiments.     

CoFe2O4自形成磁性液体场致结构化对磁化的影响

The Langevin paramagnetic theory can’t describe the relation between magnetization of ferrofluids and applied magnetic field. The structuralization of ferrofluids, which is considered the main influence factor of the magnetization, is regarded. The part of magnetization works is deposited when the structure is forming. This action influences the magnetization of ferrofluids directly or indirectly. On the base of the “compressing” model, the Langevin function that usually describes the magnetization of ferrofluid is modified, and a well-fitted curve is obtained. An equation of the relation between the equivalent volume fraction after being “compressed” and the intensity of magnetic field is discovered, which approximately describes the process of magnetization. The relation between the approximate initial susceptibility and the volume fraction can be obtained from modified formula.     

Highly regioselective Buchwald–Hartwig amination at C-2 of 2,4-dichloropyridine enabling a novel approach to 2,4-bisanilinopyridine (BAPyd) libraries

The highly regioselective Buchwald–Hartwig amination at C-2 of the cheap and readily accessible reagent, 2,4-dichloropyridine with a range of anilines and heterocyclic amines is described. This new methodology is robust and provides a facile access to 4-chloro-N-phenylpyridin-2-amines on 0.25 mol scale. These intermediates undergo a further Buchwald–Hartwig amination at higher temperature to enable rapid exploration of the chemical space at C-4 and to provide a library of 2,4-bisaminopyridines.     

KMnO4-mediated oxidative CN bond cleavage of tertiary amines: Synthesis of amides and sulfonamides

KMnO₄-mediated oxidative CN bond cleavage of tertiary amines producing secondary amine was introduced, which was trapped by electrophiles (acyl chloride and sulfonyl chloride) to form amides and sulfonamides. The reaction could take place at mild condition, tolerating a wide range of function groups and affording products in moderate to excellent yields.     

Chemistry of heterocyclic compounds at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences, over 50 years (Review)

The review contains a concise historical account and information on the most significant researches undertaken by the staff at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences on the Chemistry of Heterocyclic Compounds. Dedicated to Academician of the Russian Academy of Sciences B. A. Trofimov on his 70th jubilee. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1443–1502, October, 2008.     

A general and convenient synthesis of 4-(tosylmethyl)semicarbazones and their use in amidoalkylation of hydrogen,heteroatom, and carbon nucleophiles

A general synthesis of previously unknown semicarbazone-based α-amidoalkylating reagents, 4-(tosylmethyl)semicarbazones, has been developed. The synthesis involved three-component condensation of semicarbazones of aliphatic or aromatic aldehydes with the same or other aldehydes and p-toluenesulfinic acid. The scope and limitations of this reaction were investigated. The compounds obtained were demonstrated to be an efficient α-(4-semicarbazono)alkylating agents. They were reacted with H- (sodium borohydride), O- (sodium methylate), S- (sodium phenylthiolate), N- (pyrrolidine, sodium succinimide), P- (trialkyl phosphites), and C-nucleophiles (sodium diethyl malonate) to give the corresponding products of the tosyl group substitution, 4-substituted semicarbazones, including analogues of nitrofurazone. Among the prepared compounds tested in vitro for antibacterial and antifungal activity, three nitrofuryl-containing semicarbazones exhibited high biological activities with minimum inhibitory concentration (MIC) values of 8–32 μg/mL.     

Sulfur-directed metal-free and regiospecific methyl C(sp3)–H imidation of thioanisoles

Regiospecific and direct imidation of the methyl C(sp³)–H bond of thioanisoles is realized under mild and metal-free conditions with N-fluorobis(benzenesulfonyl)imide as an oxidant and nitrogen source. Proposed mechanism suggests that thionium ion intermediates and a Pummerer-type reaction are involved. The imidation has advantages such as high step-economy, excellent functionality tolerance, and regiospecificity, giving structurally diverse imidation products.     

Synthesis of novel chiral bidentate hydroxyalkyl-N-heterocyclic carbene ligands and their application in palladium-catalyzed Mizoroki–Heck couplings and asymmetric addition of diethylzinc to benzaldehyde

A small library of new chiral bidentate hydroxyalkyl-imidazolium salts 1 is conveniently synthesized on multi-gram scale from inexpensive and commercially available chiral pool amino acids. The corresponding carbenes, generated by deprotonation of imidazolium salts 1, in combination with palladium(II) chloride were tested in the Mizoroki–Heck coupling reaction. The most significant results in terms of yields and reactivities were achieved with low catalyst loading. The catalytic activities of these imidazolium salts were also investigated in the asymmetric addition of diethylzinc to benzaldehyde. The use of MgO nanoparticles as an additive in conjunction with these ligands played a crucial role in increasing the efficiency of these reactions.