盐酸异丙嗪的微波增敏方波伏安法测定

以玻碳电极作工作电极,在微波作用下用循环伏安法和方波伏安法研究了盐酸异丙嗪的电化学特性,结果表明微波可以增大峰电流,并应用于盐酸异丙嗪的检测,建立了一种新的检测盐酸异丙嗪的电化学方法.在最佳实验条件下,无微波作用时用方波伏安法检测盐酸异丙嗪,其响应电流与盐酸异丙嗪的浓度在4.0×10-6 ～1.0×10-4 mol/L范围呈线性关系(r=0.998 2,n=7),线性回归方程为I(A)=0.040 3c(mol/L)+5.0×10-7,检出限为4.0×10-7 mol/L;在微波作用下用方波伏安法检测盐酸异丙嗪,其响应电流与盐酸异丙嗪的浓度在4.0×10-6 ～1.0×10-4 mol/L范围有很好的线性关系(r=0.999 1,n=7),线性回归方程为I(A)=0.045 7c(mol/L)+6.0×10-7,检出限为2.0×10-7 mol/L.在4.0×10-6 ～1.0×10-4 mol/L范围微波增敏的峰电流与无微波条件下峰电流的比值平均值为1.22.该方法用于盐酸异丙嗪片的测定,结果满意.     

流动注射化学发光法测定片剂中阿昔洛韦含量

在碱性介质中,低浓度的阿昔洛韦会增强鲁米诺-H2O2体系的化学发光,据此建立了测定阿昔洛韦的新方法.该法的化学发光增强值ΔICL与阿昔洛韦的浓度在9.00×10-8～3.00×10-6mol/L范围内呈良好的线性关系,相关系数r为0.9957,检出限为7.71×10 -8mol/L.对1.00×10-6 mol/L的阿...     

聚L-苏氨酸铅笔芯修饰电极对盐酸异丙嗪的电化学行为及测定研究

通过循环伏安法(CV法)在铅笔芯电极上成功地制备了聚L-苏氨酸修饰膜,研究了铅笔芯修饰电极上的最佳聚合条件,并对电极的表面结构进行显微表征.同时,研究了盐酸异丙嗪在该修饰电极上的电化学行为.由盐酸异丙嗪在聚L-苏氨酸修饰电极上的氧化和高锰酸钾在金电极上的还原组成双安培检测体系,建立了在外加电压为0V条件下流动注射双安培法直接测定盐酸异丙嗪的新方法.在pH6.8PBS(磷酸盐缓冲溶液)中,该氧化峰峰电流与盐酸异丙嗪浓度在2.0×10-6～1.5×10-3mol/L范围内呈线性关系(r=0.9979,n=12),线性回归方程为I(nA)=1.97×107c-300,方法检出限为8.5×10-7mol/L(S/N=3).RSD为1.60%(n=20),进样频率为100样/h.     

硫酸铈-亚硫酸钠流动注射化学发光法测定多贝斯

基于多贝斯对硫酸铈-亚硫酸钠化学发光体系的抑制作用,建立了流动注射-化学发光测定多贝斯的新方法,并且研究了各种实验条件的影响。在酸性介质中,发光强度的降低(ΔICL)与多贝斯浓度在4.0×10-6~6.0×10-5mol/L范围内呈良好线性关系,回归相关系数为0.9976,方法的检出限为2.0×10-6mol/L,相对标准偏差为1.2%(n=6)。     

联吡啶钌体系电化学发光法测定克林霉素的研究

建立了以金电极为工作电极电致化学发光测定盐酸克林霉素的方法,并采用循环伏安和电致化学发光法,研究了体系的电化学行为和电化学发光行为.研究结果表明,在0.1 mol/L的硼酸(pH 8.0)缓冲溶液中,扫描速率为100 mV/s时,ECL的峰高与盐酸克林霉素浓度在1.0×10-5 ～1.0×10-4 mol/L和1.0×10-7 ～8.0×10-6 mol/L范围内呈线性关系,其线性回归方程分别为I(counts)=465.00×105c-133.80(r=0.996 8)和I(counts)=20.333×106c+100.25(r=0.995 9).方法的检出限为1.0×10-7 mol/L(S/N=3).连续测定2.0×10-5 mol/L的盐酸克林霉素溶液10次,发光强度值的RSD为1.74%.对样品进行加标回收率实验,回收率为93% ～102%.该方法具有较高的选择性和灵敏度,样品处理简单快速,用于盐酸克林霉素胶囊的测定,结果满意.     

毛细管电泳柱端电化学发光法分离测定药物和尿液中的盐酸维拉帕米

采用带有柱端电化学发光(ECL)检测池的毛细管电泳(CE)法分离并测定盐酸维拉帕米(Verapamil, VRPM).盐酸VRPM作为共反应剂,增强了吡啶钌的电化学发光强度.在优化的条件下,ECL强度与VRPM在7.0×10-7～5.0×10-4 mol/L范围内呈良好的线性关系;检出限(S/N=3)为4.6×10-8 mol/L.本方法已成功用于药物和人体尿样中盐酸VRPM含量的测定.研究了VRPM与牛血红蛋白(BHb)的相互作用,计算其结合常数为3.72×103 L/mol,最大结合量为1.375×10-4 mol.     

以苯硼酸为识别物质的电化学阻抗糖传感器的制备

以苯硼酸为识别物质,利用巯基自组装法将半胱胺与4-甲酰基苯硼酸反应形成的Schiff’s碱固定于金电极表面,构建了检测葡萄糖、乳糖、甘露聚糖的电化学阻抗传感器。根据传感器结合糖前后电子转移阻抗值的变化(ΔR et),分别进行了葡萄糖、乳糖、甘露聚糖的分析测定。以pH 9.0的5 mmol/L K3[Fe(CN)6]-5 mmol/L K4[Fe(CN)6]平衡电对溶液作为检测溶液,ΔR et与葡萄糖的浓度在5.05×10#9~5.05×10#5mol/L之间呈良好的线性关系,检出限为9.7×10#10mol/L(S/N=3);ΔR et与乳糖的浓度在2.78×10#9~2.78×10#5mol/L之间呈良好的线性关系,检出限为8.1×10#10mol/L(S/N=3);ΔR et与甘露聚糖的浓度在4.35×10#9~4.35×10#5mol/L之间呈良好的线性关系,检出限为3.4×10#10mol/L(S/N=3)。该方法简单、灵敏、成本低,可用于不同种类糖的分析检测。     

曙红B共振光散射法测定微量的盐酸异丙嗪

研究了染料曙红B与盐酸异丙嗪的结合反应.在pH=3.50的Walpole介质中,曙红B本身的共振光散射信号较弱,与盐酸异丙嗪结合形成离子缔合物后,体系的共振光散射明显增强,并且光散射增强强度与盐酸异丙嗪在一定浓度范围内成正比,据此建立了一种高灵敏测定盐酸异丙嗪的方法.在体系的最大散射波长363 nm处,测得盐酸异丙嗪的线性范围为7.5×10-8～4.5×10-6 g/mL,检测限为1.8×10-8 g/mL,用于盐酸异丙嗪片剂、针剂、人血清及尿样中盐酸异丙嗪的测定,结果令人满意.     

巯基乙酸修饰金电极电化学发光行为的研究及其对盐酸硫必利的测定

在裸金电极上制备了巯基乙酸自组装膜修饰电极(MA/SAMs-Au/CME)。基于盐酸硫必利对联吡啶钌在该电极上的电化学及其发光行为的强烈增敏作用,建立起一种直接测定盐酸硫必利电致化学发光新方法。在最佳实验条件下,盐酸硫必利在1.0×10-4～1.0×10-7mol/L与相对发光强度呈线性关系,其线性回归方程I(强度)=27.169×106c+140.26,r2=0.9959,检出限(S/N=3)为5.11×10-9mol/L。连续测定1.0×10-5mol/L盐酸硫必利10次,发光强度的RSD值为1.8%。对样品进行回收率试验,回收率在94.1%～104.9%之间,RSD为4.5%(n=5)。     

盐酸氯丙嗪在聚L-苏氨酸/多壁碳纳米管修饰电极上的电化学行为

以玻碳电极为基底成功制备了聚L-苏氨酸poly(L-Threonine)/多壁碳纳米管(MCNTs)修饰电极(p-L-Thr/ MCNTs/GCE).研究了盐酸氯丙嗪在该修饰电极上的电化学行为.该修饰电极对盐酸氯丙嗪具有明显的电催化氧化作用,并对此电极进行显微表征.本研究将此修饰电极用于流动注射不可逆双安培(FL-IB)体系的构建,即利用盐酸氯丙嗪在p-L-Thr/MCNTs/GCE上的氧化和高锰酸钾(KMnO4)在另一支铂电极上的还原构建了双安培检测体系,成功的建立了在外加电压为0 V条件下流动注射双安培法直接测定盐酸氯丙嗪的方法.在0 V外加电压下,在1 mol/L pH6.8的磷酸盐缓冲溶液的载液中,氧化峰峰电流与盐酸氯丙嗪浓度在2.0×10-6mol/L～4.0×10-5 mol/L范围内呈良好的线性关系,其线性回归方程为i (nA)=9.73×107C-50(r=0.9993,n=6),在4.0×10-5mol/L～10-3 mol/L范围内呈线性关系,其线性回归方程为i (nA)=2.33×107C+4×103 (r=0.9984,n=7),方法检出限为4.0×10-7 mol/L (S/N=3).连续测定1.00×10-4mol/L的盐酸氯丙嗪标准溶液20次,电流值RSD为2.44%,进样频率为90样/h.该方法具有较高的选择性和灵敏度.对盐酸氯丙嗪片中的盐酸氯丙嗪的含量的测定,结果比较满意.     

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.