β-环糊精修饰有机聚合物整体材料的制备及其在室温磷光分析中的应用

以甲基丙烯酸缩水甘油酯为单体,乙二醇二甲基丙烯酸酯为交联剂,偶氮二异丁腈为引发剂,正丙醇、1,4丁-二醇为致孔剂,制备了有机聚合整体材料膜片。合成的膜片经β-环糊精化学修饰后可同时用作固相萃取膜以及室温磷光测量的新型固体基质。考察了14种有机物在β-环糊精修饰膜片上的室温磷光行为,发现3吲-哚乙酸、1萘-乙酸、菲、7,8苯-并喹啉、咔唑和芴有较强的磷光信号,检出限为1.15~13.7 ng/spo。t实验发现,膜片可以选择性萃取和富集水样中的菲、7,8苯-并喹啉、咔唑和芴,检出限可降低至0.72~10.7μg/L。建立的方法用于水样中7,8苯-并喹啉和芴的测定,回收率分别为80.2%~111.6%和86.0%~101.7%,结果满意。     

L-(8-羟基-5-甲基喹啉)半胱氨酸修饰电极的制备及其对汞离子选择性检测

利用Shifft碱反应将L-半胱氨酸和5-甲酰基-8-羟基喹啉一步合成L-(8-羟基-5-甲基喹啉)半胱氨酸,通过金-硫键将L-(8-羟基-5-甲基喹啉)半胱氨酸自组装到金电极表面制备L-(8-羟基-5-甲基喹啉)修饰金电极。L-(8-羟基-5-甲基喹啉)半胱氨酸分子中的羟基氧和氮可与Hg2+形成稳定的五元环配合物,因此该修饰电极能选择性吸附Hg2+,结合方波伏安法用于Hg2+电化学检测。在0.01mol/L HCl中,富集时间为160s,Hg2+浓度在1.0×10-9~1.0×10-8 mol/L、1.0×10-8~1.0×10-7 mol/L浓度范围内与方波伏安峰电流分段呈现良好的线性关系,检出限为0.92×10-9 mol/L。     

水溶性阳离子荧光共轭聚合物作为荧光探针测定三磷酸腺苷

利用荧光光谱研究了三磷酸腺苷(ATP)与水溶性阳离子荧光共轭聚合物的相互作用,发现加入ATP后,聚合物的荧光强度被显著猝灭,且猝灭程度与ATP的加入量成正比,据此建立了测定ATP的方法.荧光光谱的激发波长选择395 nm,发射波长为521 nm,激发狭缝宽度为10.0 nm,发射狭缝宽度为10.0 nm.在0 05 mol/L Tris-HCl缓冲溶液(pH=7.4)中,测定ATP的线性范围为8.0×10-8～1.0×10-5 mol/L; 检出限为2.0×10-8 mol/L; 回收率在93.6%～105.6%之间; 相对标准偏差在2.2%～6.9%之间.本方法用于三磷酸腺苷二钠药片和鲫鱼肉中ATP的测定,获得满意结果.     

荧光光度法测定环境水样中的苯酚和对苯二酚

建立了荧光光度法直接测定环境水样中的苯酚和对苯二酚的新方法.通过β-环糊精增敏,三维荧光扫描选择测量波长,在波长对为λex/λem=273/307 nm时测定苯酚,苯酚的线性范围为0～1×10-4 mol/L,检出限为6.6×10-8 mol/L;在波长对为λex/λem=295/331 nm时测定对苯二酚, 对苯二酚的线性范围为0～1.5×10-5 mol/L,检出限为5.2×10-9 mol/L,回收率达到93.5%～103.5%.     

邻苯二甲醛-β-巯基乙醇组合试剂可视化荧光检测多巴胺

研究发现,在碱性条件下,邻苯二甲醛和β-巯基乙醇组合试剂可与多巴胺发生化学反应生成异吲哚类化合物。当用340 nm光激发时产生462 nm的荧光,且荧光强度与多巴胺含量呈良好的线性关系,从而建立了一种可视化荧光检测多巴胺的新方法。在pH 9.8的H3BO3-NaOH缓冲条件下,检测的线性范围为5.2×10-8~1.7×10-5mol/L,相关系数为0.9993,检出限(3σ)为4.1×10-8mol/L。对7.0×10-6mol/L的多巴胺进行11次平行测定,其相对标准偏差为1.4%。方法用于盐酸多巴胺注射液含量的分析,平均加标回收率为97.7%。以波长为365 nm紫外灯激发多巴胺样品,可实现多巴胺可视化半定量检测。     

血红蛋白-维生素B6-ONOO-体系的荧光特性及ONOO-分析

在中性pH值的缓冲溶液中,血红蛋白作催化剂,维生素B6与过氧亚硝酸活性氧(ONOO-)发生反应,维生素B6原来位于391 nm处的强烈的荧光发射峰消失,而在384 nm和424 nm处出现了两个新的荧光峰.据此建立了血红蛋白一维生素B6体系高灵敏检测ONOO-活性氧的新方法.方法的线性范围为5.24×10-8～2.62×10-6mol/L,检出限为2.62×10-9mol/L,对1.31×10-7mol/L的ONOO-溶液测定的相对标准偏差为3.75%(n=7).     

水中痕量铝离子的浊点萃取-荧光光度法测定

建立了荧光光度法测定水中痕量铝离子的浊点萃取分离富集新体系.在pH 6.0的HAc-NaAc缓冲体系中,水样中的铝与8-羟基喹啉生成疏水性络合物.通过85 ℃水浴加热40 min,8-羟基喹啉-铝络合物被萃取到Triton X-100表面活性剂相并与水相分开.将表面活性剂相用乙醇分散稀释至2.0 mL,在激发波长375 nm和发射波长510 nm下进行荧光测定.测定铝的线性范围为4.0 ～200.0 μg/L,方法的检出限为1.2 μg/L,相对标准偏差(RSD)为4.5%(n=11).方法用于自来水、矿泉水、河水和湖水中痕量铝的测定,加标回收率为92% ～108%.     

微乳液增敏催化荧光光度法测定叶酸的研究

报道了在微乳液介质中,当pH=3.5,以353 nm为激发波长,444 nm为发射波长,在该波长处测定钯(Ⅱ)作为催化剂催化KIO4与叶酸之间反应的荧光强度,从而间接测定叶酸的新方法.在最佳条件下,测定叶酸的线性范围为1.0×10-6～6.0×10-5 mol/L,检出限为1.0×10-7 mol/L,相对标准偏差小于2.20%,加标回收率在97%～105%范围内.CTMAB微乳液的引入可提高体系的灵敏度.结果表明,该方法具有很高的灵敏度、选择性和稳定性,可直接用于各种样品中叶酸的测定.     

钇(Ⅲ)对铽(Ⅲ)-对苯二甲酸-乙二胺体系的荧光增强及其分析应用

在pH8.0的水溶液中 ,8.0×10-4mol/L的Y(Ⅲ)可使Tb(Ⅲ) -对苯二甲酸 -乙二胺体系的荧光增强84倍;以1.0×10-8 mol/L的Tb(Ⅲ)试验 ,体系的最大荧光条件为对苯二甲酸浓度1.0×10-3 mol/L,乙二胺水溶液体积分数1 %,用量0.5mL ,激发光波长296nm ,测量的荧光发射波长546nm;实验表明 ,Tb(Ⅲ)的浓度在2.0×10-9 ～2.0×10-7mol/L范围与体系的荧光强度呈线性关系 ,据此建立了测定痕量Tb(Ⅲ)的荧光光度分析法 ,测定结果的相对标准偏差为0.80 % ,Tb(Ⅲ)的检出限为5.0×10 -11mol/L。     

柱前衍生化高效液相色谱-荧光检测法测定桑叶中的1-脱氧野尻霉素

采用柱前衍生化高效液相色谱-荧光检测法测定了桑叶中的1-脱氧野尻霉素(DNJ)。用0.05 mol/L HCl提取桑叶中的DNJ,采用6-氨基喹啉基-N-羟基琥珀酰亚氨基甲酸酯(AQC)试剂在pH 8.5硼酸盐缓冲液下对DNJ进行衍生化,以0.02 mol/L磷酸二氢钾缓冲液(pH 5.0)-乙腈(体积比为85∶15)为流动相,利用C18色谱柱(5 μm,250 mm×4.6 mm)分离,在激发波长为250 nm、发射波长为395 nm条件下进行荧光检测,DNJ的AQC衍生物与衍生化试剂的水解产物分离良好。方法的线性范围为0.5～25 mg/L,检出限为0.02 mg/L（S/N=3）。实验测得桑叶中DNJ含量为0.12%;回收率为96.1%～98.6%。     

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.