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21.
小檗碱共振光散射法测定脱氧核糖核酸   总被引:9,自引:0,他引:9  
刘晨  陈献桃  李松青  陈小明 《分析化学》2002,30(10):1218-1221
研究了小檗碱与DNA作用的共振光散射光谱,在pH=2.0-2.8的范围内,DNA的加入导致小檗碱共振光散射的增强,在308nm处,存在一共振光散射增强峰,其强度与DNA的浓度呈线性关系,据此建立了一种测定DNA的共振光散射法。该方法的线性范围为0-600μg/L,相关系数为0.9972,检出限为19.9μg/L。将该方法用于混合样品中DNA的测定。结果令人满意。  相似文献   
22.
用邻苯二甲酸二(2-乙基)己酯作为活性物质和增塑剂制作PVC膜电极。该电极对季铵盐类药物黄连素、新洁尔灭和碘解磷定具有能斯特响应,用于成品药的分析取得满意的结果。  相似文献   
23.
<正>8-Oxocoptisine 1,a natural protoberberine alkaloid,can be more easily achieved starting from readily available and inexpensive berberine hydrochlorate 2.The structure of the target compound 1 was confirmed by melting point,~1H NMR,IR,MS and elemental analysis.  相似文献   
24.
为开发高效低毒的抗肿瘤天然产物衍生物,依据药物拼合原理设计并合成了10个新型小檗碱衍生物。将盐酸小檗碱与含单硫醚、单硒醚和二硫键脂肪链片段通过缩合反应得到目标化合物,其化学结构均经过核磁共振氢谱、碳谱以及高分辨质谱确证。采用噻唑蓝(MTT)法考察其体外抗肿瘤活性,结果表明,7个化合物针对不同的癌细胞株的抑制活性优于盐酸小檗碱,同时对人正常肝细胞L02的毒性较低。化合物3e的体外抗肿瘤活性最佳(针对BEL-7402的IC50值为8.70μmol/L,选择性指数为3.61),可对其深入研究用以开发高效低毒的抗肿瘤药物。  相似文献   
25.
A comprehensive metabonomic method, in combination with fingerprint analysis and target analysis, was performed to reveal potential mechanisms of berberine action in the treatment of patients with type 2 diabetes and dyslipidemia. Serum samples of 60 patients before and after treatment with either berberine or placebo were collected. Ultra-performance liquid chromatography and quadrupole time-of-flight tandem mass spectrometry (UPLC Q-TOF MS) coupled with pattern recognition analysis were used to identify changes in global serum metabolites. Compared with placebo, patients before and after berberine treatment could be separated into distinct clusters as displayed by the orthogonal signal correction filtered partial least-squares discriminant analysis (OSC-PLS-DA) score plot, which indicated changes in circulating metabolites after berberine treatment. Among them, free fatty acids changed markedly. These were further quantified by UPLC combined with single quadrupole mass spectrometry (UPLC SQ MS). There was a highly significant decrease in the concentrations of 13 fatty acids following berberine administration. 10 fatty acids also differed statistically from placebo. These results suggest that berberine might play a pivotal role in the treatment of type 2 diabetes through down-regulating the high level of free fatty acids and that comprehensive metabonomic measurements are potentially very useful for studying the mechanisms of action of traditional Chinese medicines.  相似文献   
26.
提出了一种基于溶剂毛细流效应的微波加热自组装成环荧光显微成像技术在环境水样中的应用方法。在pH 4.58的HAc-NaAc 反应介质和聚乙烯醇-124存在下,盐酸小檗碱液滴在疏水性玻璃表面上受热挥发形成直径为1.1 mm,环带宽为19.2 μm自组装环(self-ordered ring, SOR), 其荧光被苦味酸猝灭,猝灭强度与苦味酸的浓度成正比。当点样体积为0.1 μL时,线性范围为1.3~30.0×10-7 mol·L-1,方法的检测限为1.3×10-8 mol·L-1。应用于天然水样及合成水样分析,回收率为96.3%~108.0%,RSD小于3.3%。该方法灵敏度比斑点分析提高50倍,比液相分析方法提高了60倍,且来源于背景的干扰大大降低。检测方法在环境、生化等领域具有广泛的实用性和优越性。  相似文献   
27.
在pH 6.6的磷酸盐缓冲溶液中,荧光桃红在520 nm有一个吸收峰,在560 nm处有一个荧光峰。当有小檗碱存在时,荧光桃红与小檗碱可形成稳定的紫红色缔合微粒。其最大吸收波长在560 nm,小檗碱浓度(c)在6.65×10-7~7.71×10-5mol·L-1范围内符合比尔定律,回归方程为A=1.051×104c+0.008 6,相关系数为0.996 9, 摩尔吸光系数为2.21×104 L·mol-1·cm-1。荧光桃红-小檗碱体系的光谱特性研究表明,小檗碱与荧光桃红主要通过静电引力形成疏水性的缔合微粒,在385,470,586 nm产生3个共振散射峰,560 nm荧光峰的降低是由于复合微粒形成所致。  相似文献   
28.
小檗碱与人血清白蛋白的相互作用   总被引:14,自引:2,他引:12  
利用紫外光谱和荧光光谱技术研究了中药有效成分小檗碱与人血清白蛋白(HSA)的相互作用机制。利用荧光猝灭反应测得它们之间结合常数K=1.168×105 L·mol-1,结合位点数n=5.26。依据Frster非辐射能量转移机制,测得供体-受体间结合距离R=3.44 nm和能量转移效率E=0.303。认为小檗碱在HSA的位置阻断了酪氨酸残基与色氨酸残基之间的能量转移,并使它们的荧光猝灭,并与色氨酸结合生成了较弱的荧光发光体。  相似文献   
29.
The electrochemical behavior of anticancer herbal drug berberine was investigated in 0.2 mol L‐1 HAc‐NaAc (pH 4.2) buffer solution at a glassy carbon electrode. The drug yields a single well‐defined reduction peak at the potential of ‐1.085 V at the scan rate of 0.05 V s‐1 and the electrode reaction is an irreversible adsorption‐controlled process as the result of cyclic voltammetry. All experimental conditions were studied in order to obtain the optimum conditions for the determination of berberine. A good linear relationship was observed between the reductive peak currents and the concentrations of berberine in the range from 1.0 × 10‐6 to 8.0 × 10‐5 mol L‐1. The detection limit of 8.0 × 10‐7 mol L‐1 was obtained in terms of the signal to noise ratio of 3:1 (S/N = 3). The proposed technique was applied to determine the content of berberine in tablets with good satisfactory. In addition, the electrode process dynamics parameters were calculated.  相似文献   
30.
A new extraction agent featuring dopamine self‐polymerized on magnetic Fe3O4 nanoparticles has been successfully synthesized and evaluated for the SPE of berberine from the extract of the traditional Chinese medicinal plant, Cortex Phellodendri. The nanoparticles prepared possessed a core–shell structure and showed super‐paramagnetism. It was found that these polydopamine‐coated nanoparticles exhibited strong and selective adsorption for berberine. Among the chemical components present in C. Phellodendri, only berberine was adsorbed by the nanoparticles and extracted by a following SPE procedure. Various conditions such as the amount of polydopamine‐coated nanoparticles, desorption solvent, desorption time and equilibrium time were optimized for the SPE of berberine. The purity of berberine extracted from C. Phellodendri was determined to be as high as 91.3% compared with that of 9.5% in the extract. The established SPE protocol combined advantages of highly selective enrichment with easy magnetic separation, and proved to be a facile efficient procedure for the isolation of berberine. Further, the prepared polydopamine‐coated magnetic nanoparticles could be reused for multiple times, reducing operational cost. The applicability and reliability of the developed SPE method were demonstrated by isolating berberine from three different C. Phellodendri extracts. Recoveries of 85.4–111.2% were obtained with relative standard deviations ranging from 0.27–2.05%.  相似文献   
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