盐酸克伦特罗在乙炔黑电极上的电化学行为及其分析测定研究

研究了盐酸克伦特罗(CLB)在乙炔黑电极上的电化学行为,发现阴离子表面活性剂十二烷基苯磺酸钠(SDBS)能显著提高CLB的氧化峰电流并降低其氧化过电位。优化了实验参数,建立了一种直接测定CLB的新电分析方法,其线性范围为1.0×10-7~7.5×10-5mol/L,开路富集1 min后的检出限为2.5×10-8mol/L。平行10次测定1.0×10-5mol/L盐酸克伦特的RSD为3.1%。方法用于猪尿中盐酸克伦特罗含量的测定。     

纳米CeO2修饰碳糊电极微分脉冲伏安法对盐酸克伦特罗的测定

研究了盐酸克伦特罗(CLB)在纳米CeO2修饰碳糊电极上的电化学行为.结果表明:在0.10 mol·L-1的HClO4溶液中,CLB于+0.40 V(vs SCE)左右处产生1对准可逆的氧化还原峰.与裸碳糊电极相比,CLB在修饰电极上的电流响应明显增大,据此建立了尿样中CLB的微分脉冲伏安测定方法.线性范围为5.0×10-9 ～6.0×10-6 mol·L-1(r=0.998 2,n=7),检出限为2.5×10-9 mol·L-1(3sb),加标回收率为96% ～104%.     

钯掺杂聚精氨酸修饰电极同时测定5-羟基色氨酸和多巴胺

制备了钯掺杂聚L-精氨酸修饰玻碳电极(Pd-PA/GCE),研究了5-羟基色氨酸(5-HTP)和多巴胺(DA)在该修饰电极上的电化学行为,建立了同时测定5-HTP和DA的电化学新方法。在pH=2.0的磷酸缓冲溶液中,扫描速率为160mV/s时,DA在该电极上产生一对氧化还原峰,峰电位分别为0.515V和0.464V;5-HTP在该电极上产生一个氧化峰,峰电位为0.643V,两者的氧化峰电位差达128mV。在最优条件下,同时测定5-HTP和DA的线性范围分别为:9.00×10-7~1.00×10-5 mol/L、1.00×10-5~4.00×10-5 mol/L(5-HTP);7.00×10-7~1.00×10-5 mol/L、1.00×10-5~4.00×10-5 mol/L(DA)。检出限分别为7.0×10-7 mol/L和5.0×10-7 mol/L。方法可用于药剂中5-HTP和DA的测定。     

聚赖氨酸修饰电极在抗坏血酸共存时测定肾上腺素

在pH8.0磷酸盐缓冲溶液(PBS)中利用循环伏安法制备了聚赖氨酸修饰电极,在pH4.0 PBS中,聚赖氨酸膜对肾上腺素(EP)的电化学氧化具有明显的催化作用.利用循环伏安法测定EP还原峰电流可排除抗坏血酸(AA)干扰.肾上腺素还原峰电流与其浓度分别在6.3×10-7mol/L~1.0×10-5 mol/L与1.0×10-5mol/L~1.2×10-4 mol/L范围内呈良好线性关系,相关系数分别为0.9978与0.9975,;检出限(S/N=3)为7.2×10-8mol/L.该方法具有良好的灵敏度、选择性,已用于针剂样品分析.     

阿霉素在氧化铟锡电极上的电化学行为及其应用

阿霉素(ADM)在0.02 mol/L pH 7.50的NaH2PO4-Na2HPO4缓冲溶液中,用氧化铟锡(ITO)电极进行线性扫描伏安法测定,得到一良好的还原峰,其峰电位为-0.63 V。峰电流与ADM浓度在1.0×10-7~5.0×10-6mol/L范围内呈线性关系,检出限为5.0×10-8mol/L。用循环伏安法研究了体系的电化学行为及电极反应机理。实验表明,该体系属两电子还原的不可逆过程。     

盐酸阿霉素在玻碳电极上的电化学行为研究及分析应用

采用线性扫描伏安法和循环伏安法研究了盐酸阿霉素在玻碳电极上的电化学行为及电极反应机理,优化了测定盐酸阿霉素的各实验参数。结果表明,在0.01 mol/L的HCl溶液中,盐酸阿霉素在-0.40 V处出现(vs.SCE)一灵敏的还原峰,峰电流与其溶液浓度在5.0×10-8~1.0×10-6mol/L(r=0.999)和1.0×10-6~1.0×10-5mol/L(r=0.998)范围内呈良好的线性关系,检出限为1.0×10-8mol/L。并用循环伏安法研究了盐酸阿霉素的峰电流性质,发现电极反应属于准可逆过程,出现一对灵敏的氧化还原峰,体系属准可逆吸附波。利用盐酸阿霉素在玻碳电极的电化学行为建立的分析方法可用于盐酸阿霉素的质量监控及药代动力学研究。     

二茂铁巯基化合物/金纳米粒子/还原石墨烯修饰电化学传感器检测Cu~(2+)

通过Hummer法进一步还原合成还原石墨烯(RGO),Shifft碱反应合成新型二茂铁巯基化合物(FcSH)。利用还原石墨烯吸附性将石墨烯修饰在玻碳电极(GCE)上,在石墨烯表面电沉积金纳米粒子(AuNPs),通过自组装制备还原石墨烯和二茂铁巯基修饰电化学传感器(FcSH/AuNPs/RGO/GCE),该电化学传感器具有大的比表面积和富电子性能。实验显示,在0.01 mol/L HCl中,富集时间为180s,Cu~(2+)浓度在1.0×10~(-12)~1.0×10~(-11)mol/L与1.0×10~(-11)~1.0×10~(-10)mol/L范围内与方波伏安峰电流分别呈现良好的线性关系,检出限为0.94×10~(-12)mol/L。该电化学传感器对Cu~(2+)的检测表现出较好的选择性、高的稳定性和灵敏性,可用于环境中痕量Cu~(2+)的测定。     

镍纳米粒子-离子液体修饰碳糊电极的制备及其对多巴胺的测定

制备了镍纳米粒子-离子液体修饰电极,在0.1 mol/L磷酸缓冲溶液(pH 6.0)中研究了多巴胺(DA)在修饰电极上的电化学行为.与裸电极相比,DA在该修饰电极上的氧化还原电位明显降低,氧化还原反应的峰电流明显增大,DA的峰电流与其浓度在2.0×10~(-8) ～1.0×10~(-4) mol/L范围内呈良好的线性关系,检出限为6.5×10~(-9) mol/L.该修饰电极对抗坏血酸具有明显的抗干扰能力.     

碳纳米管/纳米金修饰金电极上柔红霉素电化学行为的研究

将碳纳米管与纳米金结合修饰在金电极上制成修饰电极,并用于柔红霉素(DNR)的电化学行为研究和检测.在4.4 mmol/L磷酸盐缓冲溶液(pH=5.81)中,DNR在碳纳米管-纳米金/Au电极上有一对灵敏的氧化还原峰.还原峰电流与DNR的浓度在3.2×10-8～1.0×10-6mol/L和1.0× 10-6～2.2× 1...     

冬凌草甲素的电化学性质及电分析方法研究

研究了抗癌药物冬凌草甲素在悬汞电极上的电化学行为。在NaAc-NaOH(pH 7.8)的缓冲溶液中,冬凌草甲素有一受吸附控制的还原峰,峰电位为-1.150 V,峰电流与冬凌草甲素浓度在7.25×10-7~1.01×10-5mol/L范围内有良好的线性关系,检出限为1.45×10-7mol/L(S/N=3)。对冬凌草片剂实际样品中冬凌草甲素含量测定,结果满意。     

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.