异硫氰酸荧光素-牛血红蛋白化学发光反应的研究

研究了在碱性介质和阳离子表面活性剂CTMAB存在下,NaClO氧化异硫氰酸荧光素-牛血红蛋白标记物的化学发光行为和化学发光反应的条件,提出了反相流动注射化学发光测定牛血红蛋白的新方法.该法测定牛血红蛋白线性范围为0.26～12.8μg/mL,检出限为0.128μg/mL.     

毛细管电泳高频电导法测定虫草中的有效成份

建立了毛细管电泳高频电导法同时测定腺苷和虫草素的方法。实验对电泳介质的种类、浓度以及操作电压和进样时间等因素进行了优化,在4mmol／L乳酸＋10％异丙醇＋80μg／mL羟甲基纤维素钠（pH=4．0）,分离电压20．OkV的条下测定了天然虫草和人工虫草菌丝制品中的腺苷和虫草素的含量,线性范围分别为2．0μg／mL～120μg／mL和3．0μg／mL～110μg／mL,检出限分别为0．5μg／mL和1．0μg／mL。     

流动注射化学发光法测定甲氧氯普胺

在酸性条件下，甲醛对高锰酸钾氧化甲氧氯普胺的化学发光反应有很强的增敏作用，据此，建立了流动注射化学发光法测定甲氧氯普胺纳新方法。方法的线性范围为0．4-100μg/mL，检出限为0．2μg/mL，对10μg/mL的甲氧氯普胺标准溶液连续11次测定的相对标准偏差为1．8％。方法已用于药物中甲氧氯普胺含量的测定。     

异硫氰酸荧光素-人血清白蛋白标记物化学发光反应的研究

采用反相流动注射分析方法,研究了异硫氰酸荧光素（FITC）－人血清白蛋白（HSA）标记物的化学发光性能和反应的最佳条件,建立了化学发光测定人血清白蛋白的新方法。体系的化学发光强度与人血清白蛋白的含量在0．08－16μg/mL内呈线性关系,方法的检出限为0．04μg/mL。讨论了蛋白质标记物化学发光性增强的原因。     

高碘酸钾氧化溴甲酚紫动力学光度法测定间苯二酚

在碱性和沸水浴条件下,微量的间苯二酚对高碘酸钾氧化溴甲酚紫褪色的反应具有显著的促进作用,据此建立了测定间苯二酚的新动力学光度法。该方法测定间苯二酚的线性范围为0．10～5．0μg／mL,检出限为0．041μg／mL,对于2．0μg／mL的间苯二酚11次测定的相对标准偏差是1．94％。方法用于皮炎宁酊及水样中间苯二酚的测定,结果满意。     

反相流动注射-化学发光法测定氨基酸

基于碱性条件，氨基酸对次氯酸钠-一鲁米诺化学发光体系的显著增敏作用，建立了反相流动注射-化学发光法测定氨基酸的新方法。该法不需对氨基酸进行衍生或转化，检出限为0．016μg/mL，采样频率为150次／h，对1μg／L的组氨酸进行连续12次平行测定，其RSD为0．9％。对氨基酸注射液样品中的氨基酸测定的回收率在98．6％～102．1％之间，并和经典的茚三酮比色法进行了对照。     

铜（III）配合物-罗丹明6G体系流动注射化学发光法测定头孢米诺钠

在酸性条件下,头孢米诺钠对铜（III）配合物-硫酸-罗丹明6G化学发光体系有强烈的增敏作用,据此建立了流动注射化学发光法定量分析头孢米诺钠方法。头孢米诺钠浓度在2．0×10^-7-6．0×10^-6g／mL范围内与化学发光强度呈良好的线性关系,相关系数r=0．99969,检出限为1．4×10^-7g／mL。对2．0×10^-7g／mL头孢米诺钠水溶液进行11次平行分析,测定结果的相对标准偏差为1．69％。利用该方法对鸡血样品和头孢米诺钠针剂中头孢米诺钠的含量进行测定,加标回收率为90．2％～102．1％。     

溴酸钾氧化中性红动力学光度法测定甲醛

在一定温度和酸性介质条件下,甲醛对溴酸钾氧化中性红的反应具有显著的催化作用,据此建立了测定甲醛的新动力学光度分析法。方法的线性范围为0．10～1．10μg／mL,检出限为0．063μg／mL,对于0．40μg/mL甲醛11次测定的相对标准偏差是1.77％。本法应用于水样及漆料中甲醛的测定,结果满意。     

火焰原子吸收光谱法连续测定香蕉中的铜铁锌锰

研究了香蕉中的金属元素的含量和火焰原子吸收光谱法在同一体系中测定香蕉中微量元素铜、铁、锌、锰的方法，考察了硝酸、过氧化氢的不同用量以及消化时间长短的影响和在同一体系中铜、铁、锌、锰的相互干扰情况。在选定条件下铜检测限为0．064μg／mL，铁为0．275μg／mL，锌为0．157μg／mL，锰为0．187μg／mL，相对标准偏差为1．9％-4．7％，回收率为92．3％-105．0％。     

DNA荧光探针—荧光素-中性红体系的研究

基于DNA对荧光素(FL)-中性红(NR)分子间荧光能量转移的抑制作用，以荧光素-中性红为荧光探针，考察该探针与DNA的结合反应，建立了准确测定DNA的新方法，在pH＝6.5条件下，hsDNA、ctDNA和smDNA的浓度与荧光素-中性红体系的荧光比值变化量Δ(Fd／Fa)成线性关系，响应线性范围分别为0．25-6．25μg／mL、0．10-5．00μg／mL、0．10-4．00μg／mL，0.025μg/mL和0．023μg／mL；分析测定了DNA合成样品，回收率91．3％-101．4％，相对标准偏差小于4．2％．     

α-Amino acid derived enaminones and their application in the synthesis of N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates and other heterocycles

A new and simple synthesis of novel N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates, which exist in equilibrium with their 4-oxo tautomers, has been developed in two steps starting from N-protected α-amino acids. The key intermediates are enaminones, which can also be isolated, characterized, and used for the construction of other functionalized heterocycles, before they spontaneously decompose to pyrrole products. 4-Hydroxypyrroles are prone to partial aerial oxidation but can be efficiently alkylated or reduced to stable polysubstituted pyrrolidine derivatives.     

Specific intramolecular aromatic CH insertion of diazosulfonamides

The chemoselectivity in the intramolecular CH insertion of various diazosulfonamides has been experimentally studied. The results reveal that the aliphatic 1,4-, 1,5-, or 1,6-C(sp³)?H insertions of diazosulfonamides are not accessible, while the aromatic 1,5-C(sp²)?H insertion can be realized specifically by adjusting the diazo-adjacent group. In addition, the general chemoselectivities in the intramolecular CH insertions of diazosulfonyl compounds are summarized. Generally, diazosulfones undergo both aromatic 1,5-C(sp²)?H and aliphatic 1,5- and 1,6-C(sp³)?H insertions, while diazosulfonates undergo aliphatic 1,5- and 1,6-C(sp³)?H insertions. However, diazosulfonamides only undergo aromatic 1,5-C(sp²)?H insertion.     

N-Heterocyclic carbene-palladacyclic complexes: synthesis,characterization and their applications in the C-N coupling and α-arylation of ketones using aryl chlorides

N-Heterocyclic carbene-palladacyclic complexes 3 were successfully achieved in a one-pot procedure under mild conditions. The structure of 3a was unambiguously confirmed by X-ray single crystal diffraction and it was an active catalyst in the Buchwald-Hartwig amination and α-arylation of ketones even at very low catalyst loadings (0.01?mol%).     

Iodine-mediated oxidative Pictet-Spengler reaction using terminal alkyne as the 2-oxoaldehyde surrogate for the synthesis of 1-aroyl-β-carbolines and fused-nitrogen heterocycles

An efficient iodine-mediated oxidative Pictet-Spengler reaction in dimethyl sulphoxide (DMSO) using terminal alkynes as the 2-oxoaldehyde surrogate for the synthesis of aryl (9H-pyrido[3,4-b]indol-1-yl)methanones is described. The scope of the protocol includes the total synthesis of Fascaplysin, Eudistomins Y₁ and Y₂. The methodology is extended for preparing pyrrolo[1,2-a]-quinoxaline and indolo[1,5-a]quinoxaline derivatives. The utility of 1-aroyl-β-carbolines was demonstrated by performing palladium-catalyzed β-carboline directed ortho-C(sp2)-H functionalization of the phenyl ring with thiomethyl (SMe) group using DMSO as source and for accessing 4-aryl-canthin-6-ones.     

Facile synthesis of bicyclic 1-arylpyrazol-5-ones

In this Letter, we described a facile method for constructing fused bicyclic 1-arylpyrazol-5-one ring system. We employed various methylene-containing carboxylic acids as the substrates and proved that the pyrazolone ring closure requires activated methylene group in intermediate II. Accordingly, a series of structurally diversified, fused bicyclic 1-arylpyrazol-5-ones was prepared in moderate to high yields using the requisite substrates.     

A carbanion induced synthesis of highly congested pyrazole and imidazole containing heterocycles

An efficient approach to the synthesis of highly congested di, penta and hexacyclic pyrazoles as well as imidazole fragment containing novel heterocyclic molecule has been developed through a carbanion induced transformation of suitably functionalized 2H-pyran-2-ones, benzo[h]chromene and thiochromeno[4,3-b]pyrans. Due to the presence of fluorescence, we report their prime application metal sensor as off/on switching in ferric ions.     

Synthesis of pyrrolo[1,2-a]pyrazines and pyrazino[1,2-a]indoles by Curtius reaction in Morita-Baylis-Hillman derivatives

Synthesis of substituted pyrrolo[1,2-a]pyrazines and pyrazino[1,2-a]indoles from the Morita-Baylis-Hillman derivatives of acrylates via saponification followed by Curtius reaction is described.     

正丁胺对激光染料荧光谱影响的研究

用正丁胺作为碳源,采用射频辉光放电制备碳膜,选用激光染料R6G和聚乙二醇混合液作为蒸气源,采用单源热蒸发,在蒸发室与染料同时沉积得到混合膜,用拉曼光谱和红外光谱分析了碳膜的结构和键合方式,分析表明:碳膜中存在胺基团和氢原子.混合膜的荧光谱测量结果表明,认为正丁胺对染料荧光谱的影响是因为胺基和氢原子的存在.     

Selective synthesis of 4,5-dihydroimidazo- and imidazo[1,5-a]quinoxalines via modified Pictet–Spengler reaction

An efficient tandem approach for the selective synthesis of 4,5-dihydroimidazo[1,5-a]quinoxalines 6a–g and imidazo[1,5-a]quinoxalines 7a–h by the reaction of 2-imidazolyl anilines 4a–c with aryl aldehydes 5a–k under mild reaction conditions is described. Introduction of electron releasing alkyl groups in substrates 4a–b was found to be instrumental for the success of the reaction.     

Understanding the Diels-Alder reactivity of 1,2-azaborine analogues

The Diels-Alder reactivity of 1,2-heteroborines (H₄C₄B(H)X, X?=?NH, PH, AsH; O, S, Se) has been computationally explored by means of Density Functional Theory (DFT) calculations. The influence of the HB?=?X fragment on the reactivity of the system has been quantitatively analyzed in detail by means of the so-called Activation Strain Model (ASM) of reactivity. It is found that the interaction between these species and the dienophile is significantly stronger than that computed for their all-carbon isoelectronic counterpart, benzene. In addition, the strain energy plays a key role in the observed reactivity trends. The role of the aromaticity strength of these heteroarenes on the reactivity is also assessed.