毛细管电泳-激光诱导荧光检测法分离检测谷胱甘肽及其构成氨基酸

以4-氯-7-硝基苯并-2-氧杂-1,3-二唑(NBD-Cl)为柱前衍生试剂,建立了一种毛细管电泳-激光诱导荧光直接检测氧化型和还原型谷胱甘肽及其构成氨基酸(谷氨酸、半胱氨酸和甘氨酸)的新方法。经过实验条件的优化,采用25 mmol/L硼砂-20 mmol/L聚氧乙烯月桂醚(Brij-35)-5%乙腈(pH 9.5)的缓冲体系,在柱温为25°C、分离电压为20 kV的条件下,压力进样3447.5 Pa(0.5 psi)×3 s,五种物质在11 min内实现高效基线分离。在该方法下,还原型谷胱甘肽、氧化型谷胱甘肽、谷氨酸、半胱氨酸和甘氨酸的线性范围分别为:1～50μg/mL,1～50μg/mL,0.5～25μg/mL,1～50μg/mL,0.1～20μg/mL;检测限分别为:0.1μg/mL,0.1μg/mL,0.005μg/mL,0.1μg/mL,0.001μg/mL。以还原型谷胱甘肽钠粉针剂为样品,方法的加标回收率为99.5%～110.7%,相对标准偏差为0.26%～3.272%(n=3)。该方法准确、快速、灵敏、检测限低,有望用于样品中氧化型和还原型谷胱甘肽及其构成氨基酸的含量分析。     

双氧水活化-面粉酶抑制法测定蔬菜中有机磷农药

基于α-乙酸萘酯和固蓝B在面粉酶的催化作用下生成紫红色的偶氮化合物,而有机磷农药在双氧水的活化下会抑制酶的催化作用,其抑制程度与农药的浓度在一定范围内呈线性关系,由此建立了一种快速测定有机磷农药的方法。探讨了最佳的反应条件,测定甲基对硫磷和甲胺磷的线性范围分别为1~10μg/mL,1~50μg/mL,最低检出限分别为0.1136μg/mL,0.3525μg/mL。该法具有试剂廉价易得、操作简便、迅速的特点,适合果蔬中常见有机磷农药的快速检测。     

流动注射-化学发光法测定血浆中盐酸阿霉素

在碱性介质中,K3[Fe(CN)6]与鲁米诺产生化学发光反应,盐酸阿霉素对该体系的发光强度具有显著的抑制作用,且光信号的减小值(△I)与盐酸阿霉素的浓度在一定的范围内成正比。基于此建立了一种流动注射化学发光法测定盐酸阿霉素的新方法。在最优实验条件下,该方法的线性范围为0.4～2.5μg/mL,检出限为2.9×10-2μg/mL。对1.2μg/mL的盐酸阿霉素连续平行测定11次,其相对标准偏差为2.1%。该方法用于血浆中盐酸阿霉素的分析,回收率在98.4%～102.0%之间。     

ICP-AES法同时测定土壤中有效态的硫和硼

采用一种方法同时提取国标土壤样品中的有效态硫和硼元素,再使用ICP-AES法进行测定。其测定值与标准值相比,硫和硼的相对误差分别小于1.4%和13%,均在允许误差范围内;方法的相对标准偏差,硫为3.2%~3.4%,硼为6.3%~7.6%;磷酸钙溶液作为提出剂条件下,方法的检出限硫为0.114μg/mL,硼为0.0039μg/mL,氯化钙溶液作为提出剂条件下,硫为0.151μg/mL,硼为0.0035μg/mL。     

顶空气相色谱法同时测定新药CBT108中12种残留溶剂

采用顶空气相色谱技术,建立了同时测定新药CBT108中12种残留溶剂的方法。优化了平衡加热时间和程序升温时间以及制样的溶剂,并通过验证确定了本方法的合理性、准确性和可行性。在优化的实验条件下,采用DB-624型毛细管柱(6%氰丙基苯基-94%二甲基聚硅氧烷为固定液,30 m×0.53 mm×3.0μm)分离、氢火焰离子化检测器检测、内标法定量的分析方案,实现了甲醇、乙醇、乙醚、丙酮、乙腈、二氯甲烷、正己烷、乙酸乙酯、四氢呋喃、庚烷、甲苯和四氯化碳共12种残留溶剂的同时分离与测定。12种溶剂在各自的范围内线性关系良好,线性相关系数(R~2)均0.997;以10倍信噪比确定方法定量限,以3倍信噪比确定方法检出限,分别为:甲醇0.024μg/mL、0.0072μg/mL;乙醇0.1μg/mL、0.012μg/mL;乙醚0.01μg/mL、0.005μg/mL;丙酮0.1μg/mL、0.008μg/mL;乙腈1.025μg/mL、0.0615μg/mL;二氯甲烷0.09μg/mL、0.06μg/mL;正己烷0.0174μg/mL、0.0145μg/mL;乙酸乙酯0.25μg/mL、0.008μg/mL;四氢呋喃0.108μg/mL、0.014μg/mL;四氯化碳0.16μg/mL、0.0004μg/mL;庚烷0.0075μg/mL、0.005μg/mL;甲苯0.0445μg/mL、0.0014μg/mL。在3个添加水平下,12种残留溶剂的加标回收率在90.96%~108.67%之间,相对标准偏差为0.1%~5.7%。结果表明,本法简单、快速、重现性好、准确性高,可用于实际药品中以上12种残留溶剂的检测,并可对其它药物中残留溶剂的检测提供参考。     

微乳液体系共振光散射法测定蛋白质

在酸性条件下,十二烷基磺酸钠微乳液与牛血清白蛋白(BSA)形成离子缔合物,使其共振散射光强度增强。研究了相应的光谱特征、影响因素及反应条件。在最佳实验条件下,BSA在0~5.0μg/mL范围内与散射光强度呈线性关系。方法的检出限为0.08μg/mL,可用于人血清样品中蛋白质的测定。     

同步荧光光谱法直接测定尿液中卡那霉素

基于卡那霉素对CdTe量子点荧光的增强效应,建立一种直接测定尿液中卡那霉素含量的同步荧光光谱法。研究发现采用同步荧光光谱法,能够有效避免尿液中复杂基质的荧光干扰。在优化实验条件下,卡那霉素浓度在0.2~20.0μg/mL范围内与体系相对同步荧光强度呈良好的线性关系,相关系数为0.9996,检出限为0.005μg/mL。该方法用于尿液样品中卡那霉素含量的直接测定,回收率为96.3%~104.4%。     

化学发光法同时测定色氨酸和半胱氨酸的研究

基于色氨酸和半胱氨酸对Ru(pheo)32 -Ce(Ⅳ)体系化学发光的增强作用及其发光动力学性质的显著差别,提出了一种化学发光法同时测定这两种氨基酸的新方法.在优化的实验条件下,该方法测定色氨酸和半胱氨酸的线性范围分别为0.05～2.0 μg/mL和0.05～3.0 μg/mL,检出限分别为0.03 μg/mL和0.02 μg/mL.将其应用于合成样品中两种氨基酸的同时测定.结合文献提出了可能的化学发光反应机理.     

极谱法测定毒死蜱等有机磷农药残留

建立了测定毒死蜱、辛硫磷、乐果、水胺硫磷和三唑磷5种常见有机磷农药残留的极谱分析新方法。优化实验条件下,毒死蜱浓度在0.0192~24.0μg/mL范围内与峰电流成线性关系,检出限为0.012μg/mL,回收率在90.36%~103.3%范围。其它有机磷农药的线性范围分别为:辛硫磷0.016~25.2μg/mL,乐果13.41~33.52μg/mL,水胺硫磷为17.42~34.84μg/mL,三唑磷为0.0110~21.2μg/mL。用极谱法研究了毒死蜱的电化学行为,证明了电极反应物为水杨基荧光酮,极谱波为不可逆还原吸附波。     

精氨酸的流动注射化学发光法测定

在碱性介质中,精氨酸对硫氰化钾 鲁米诺化学发光体系有增敏作用,建立了用硫氰化钾 鲁米诺 精氨酸体系测定精氨酸的新方法。用该方法测定精氨酸的线性范围为0.01～2.0μg/mL,检出限0.01μg/mL,采样频率为190次/h,对3μg/mL的精氨酸连续平行测量10次,RSD为1.2%。用该方法对皮革屑中酶法提取的精氨酸进行了测定,并与氨基酸测定仪测定的结果进行了比较。     

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.     

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.     

Cu0-catalysed 1,3-dipolar cycloadditions of α-amino acid derived N,N-cyclic azomethine imines to ynones

A series of 20 CuAIAC reactions between eight 4-acylamino substituted pyrazolidine-3-one-1-azomethine imines and four terminal ynones were performed using Cu⁰ as catalyst. The corresponding fluorescent cycloadducts were obtained in very high yields upon simple workup. Thus, Cu-metal turned out to be a better catalyst than Cu^I in terms of yield and ease of isolation. Availability of azomethine imines, mild reaction conditions, and simple workup enable a “click” access to libraries of densely substituted 2,3-dihydro-1H,5H-pyrazolo[1,2-a]pyrazol-1-ones. Reactivity of differently substituted dipoles was evaluated experimentally and by quantum chemical methods (DFT).     

Synthesis and antioxidative/anti-inflammatory activity of novel fullerene–polyamine conjugates

(E)-4-(Fullerenopyrrolidin-1-yl)-3-methylbut-2-enoic acid and its corresponding succinimidyl ester, readily obtained through Prato-type modification of C₆₀, were used for the selective N-acylation of polyamines. The thus obtained conjugates were evaluated for their antioxidative and anti-inflammatory activity and their cytotoxicity was determined. Members of this family of compounds showed interesting anti-lipid peroxidation, anti-lipoxygenase and anti-inflammatory activity and comparable cytocompatibility to spermidine.