杯芳烃涂层毛细管分离单胺类神经递质

本文设计制作了一种对烯丙基杯 [4 ]芳烃涂层毛细管。用于毛细管电泳分离的结果表明 ,此管能分离 5 羟色胺 ( 5 HT)、多巴胺 (DA)、去甲肾上腺素 (NE)、肾上腺素 (E)等结构相近的单胺类神经递质 ,而无涂层管则不能。本涂层管在pH4～ 9范围内的电渗较无涂层管下降约 75% ,且当pH <8时 ,电渗随pH的变化接近于线性关系 ,有利于高重现分离。杯芳烃涂层毛细管不降低紫外检测灵敏度。其主要问题是酚羟基对胺类仍有吸附 (或静电 )作用     

集成芯片毛细管电泳电化学检测系统

研制了一种新颖的集成芯片毛细管电泳电化学检测装置。此装置基于柱末安培检测法，将检测池集成芯片上，以自制的30μmPt微盘电极为工作电极，在几十年秒钟内实现了多巴胺、5－羟色胺和肾上腺素三种神经递质的快速分离检测。     

芯片毛细管电泳-NDA柱前衍生荧光检测多巴胺及组胺

本文以汞灯为激发光源,利用自组装的高灵敏芯片毛细管电泳荧光光子计数器检测系统,NDA柱前衍生检测神经递质多巴胺和组胺。优化了NDA衍生多巴胺、组胺以及衍生后分离与检测的条件。本法多巴胺和组胺的检出限(S/N=3)分别为2.5×10-7mol/L、1.4×10-6mol/L。组胺和多巴胺可在45s内分离和检测。     

多巴胺和5-羟色胺的毛细管电泳测定

建立了高效毛细管电泳结合柱上紫外检测测定单胺类神经递质多巴胺(dopamine,DA)和5_羟色胺(5_hydroxytryptamine,5_HT)的毛细管电泳方法 ,优化了缓冲液 pH值、浓度、电压等实验参数 ;结果表明 ,在优化的实验条件下 ,多巴胺、3,4_二羟苄胺 (3,4_dihydroxybenzylamine)和5_羟色胺在10min内得到很好的分离 ,检出限分别为2.02×10 -5mol/L,1.01×10 -5mol/L,1.20×10 -5mol/L ;该法简便、快速 ,样品用量少 ,结果准确 ,重现性好     

胶束电动毛细管色谱半导体激光诱导荧光测定单胺类神经递质

建立了用半导体激光诱导荧光结合胶束电动毛细管色谱测定单胺类神经递质——去甲肾上腺素和多巴胺的高灵敏分析方法。考察了青色素衍生物 ( Cy5 )对去甲肾上腺素和多巴胺的衍生条件。在优化条件下 ,去甲肾上腺素和多巴胺在 3× 1 0 - 8～ 5× 1 0 - 6 mol/L浓度范围内与荧光强度呈良好的线性关系。去甲肾上腺素和多巴胺的检出限分别为 5 .9× 1 0 - 9、 5 .4× 1 0 - 9mol/L。方法简便、灵敏、样品用量少 ,可用于痕量单胺类神经递质分析     

生物胺类神经递质的电化学检测研究进展

就1993-2005年生物胺类神经递质包括多巴胺、肾上腺素、去甲肾上腺素、5-羟色胺的各种电化学检测方法的应用研究和发展方向进行了评述。引用文献58篇。     

神经递质类相关物质的毛细管电泳分离及实际尿液的检测应用

建立了单胺类神经递质（5-羟色胺、多巴胺和肾上腺素）、神经递质类代谢产物（高香草酸、5-羟吲哚乙酸和香草扁桃酸）及神经递质类前体（精氨酸和酪氨酸）混合物的毛细管电泳（CE）分离方法. 利用标准试剂混合样考察了缓冲体系的组成、pH值及添加剂对分离的影响,并探讨了尿液中基体成分如肌酸酐、尿酸和乙酰乙酸对分离的干扰. 在Na₂B₄O₇-NaOH缓冲体系（pH=9.90）及紫外（UV）检测（波长200 nm）条件下对8种神经递质类相关物质的分析获得了良好的定量线性关系,检出限（LOD）为0.04~0.60 μmol/L,迁移时间和峰面积的相对标准偏差（RSD,n=5）范围分别为0.09% ~0.48%和0.47% ~3.34%. 利用该方法对实际尿液中的精氨酸和香草扁桃酸进行了定性和定量分析,其定量结果分别为（95.8±3.8）和（44.6±3.5） μmol/L,加标回收率为96.65%~104.5%.     

径向电场调制毛细管电泳法用于神经递质分离

利用双向电场控制毛细管电泳系统，考察了神经递质的分离。在pH2.5的0.01mol/L磷酸盐缓冲体系中，通过加入20％（V／V）正丙醇，改善了多巴胺和5－羟色胺的分离效果，但仍不太理想。通过施加径向电场，可进一步提高分离度。本研究不仅拓宽了径向电场调控的样品分离范围，而且为生物活性物质的痕量分析提供了参考依据。     

毛细管电泳-间接化学发光法分离检测儿茶酚胺及儿茶酚

根据儿茶酚胺及儿茶酚淬灭铁氰化钾-鲁米诺体系发光的原理,利用毛细管电泳．化学发光联用技术分离测定了3种儿茶酚胺和儿茶酚,并优化了检测和分离条件。在最佳条件下,测得多巴胺、肾上腺素、去甲肾上腺素和儿茶酚的检出限分别为0．33、1．8、2、4和0、12μmol／L。本方法具有一定的选择性,对于医用注射液及尿样在未经预处理条件下可直接进行分离分析,结果令人满意。     

荧光法测定SD大白鼠不同脑区的单胺类神经递质

以荧光光谱法定量地研究了不同浓度的司考林作用下,鼠脑组织中去甲肾上腺素、多巴胺和5-羟色胺的定量变化,从而表达了中枢神经递质的变化规律.     

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.     

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%).     

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.     

Synthesis of N-substituted carbazolones from α-iodo enaminones via Pd(0)-catalyzed intramolecular coupling under microwave irradiation

A variety of N-aryl and N-alkyl carbazolones were conveniently achieved in good to high yields via Pd₂(dba)₃-mediated intramolecular coupling of N-substituted α-iodo enaminones under microwave irradiation. The Pd(0)-catalyzed cyclization was found to proceed favorably with the more electron-deficient phenyl ring during the reactions involving unsymmetrical N,N-diaryl α-iodo enaminones. This unique property enables the construction of carbazolone skeleton containing nitro substituted benzenoid ring.     

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.     

Synthesis of substituted 2,4,5,6-tetrahydrocyclopenta[c]pyrazoles and 2,4,5,6-tetrahydropyrrolo[3,4-c]pyrazoles by intramolecular nitrilimine cycloaddition

Both substituted 2,4,5,6-tetrahydrocyclopenta[c]pyrazoles and 2,4,5,6-tetrahydropyrrolo[3,4-c]pyrazoles have been synthesized by the 3+2 intramolecular dipolar cycloaddition of nitrilimines to alkynes. This cyclization has been extended to more versatile 3-bromo derivatives by the use of alkynylbromides as dipolarophiles.