亲水作用色谱法测定表阿霉素及其杂质

建立了一种以亲水作用色谱分离测定表阿霉素的新方法。采用硅胶色谱柱及高极性有机溶剂水相缓冲溶液流动相。对流动相的pH、缓冲溶液的浓度及流速进行了优化,确定了以乙腈甲酸钠缓冲溶液(pH2.9)(90∶10,V/V)作为流动相的最佳条件。对优化的分离条件进行系统适应性实验,结果表明表阿霉素与有关杂质之间的分离度和拖尾因子均达到药典要求。该法具有良好的线性(相关系数0.9971～0.9991)和重复性(峰面积RSD<1.0%),方法简便实用,用于实际样品分析,结果满意。     

置换色谱法分离表阿霉素和阿霉素异构体的研究

采用置换色谱法在Kromasil KR100-10C18色谱柱(250 mm×4.6 mm i.d.,10 μm)上成功地分离了二元异构体表阿霉素和阿霉素的混合物,并研究和探讨了置换剂类型、浓度、流动相的组成及流速对分离的影响。结果表明：选用30 g/L的海胺1622为置换剂,流速0.2 mL/min,以及在有机相比例较低的流动相中加样,而将置换剂溶解在有机相比例稍高的流动相中进行置换展开,可以达到较好的分离。在最佳分离条件下,采用置换展开方式可以在分析色谱柱上一次分离30 mg异构体的混合物。该结果充分     

2,4-Dinitrophenol as an Uncoupler Augments the Anthracyclines Toxicity against Prostate Cancer Cells

One of the strategies for the treatment of advanced cancer diseases is targeting the energy metabolism of the cancer cells. The compound 2,4-DNP (2,4-dinitrophenol) disrupts the cell energy metabolism through the ability to decouple oxidative phosphorylation. The aim of the study was to determine the ability of 2,4-DNP to sensitize prostate cancer cells with different metabolic phenotypes to the action of known anthracyclines (doxorubicin and epirubicin). The synergistic effect of the anthracyclines and 2,4-DNP was determined using an MTT assay, apoptosis detection and a cell cycle analysis. The present of oxidative stress in cancer cells was assessed by CellROX, the level of cellular thiols and DNA oxidative damage. The study revealed that the incubation of LNCaP prostate cancer cells (oxidative phenotype) with epirubicin and doxorubicin simultaneously with 2,4-DNP showed the presence of a synergistic effect for both the cytostatics. Moreover, it contributes to the increased induction of oxidative stress, which results in a reduced level of cellular thiols and an increased number of AP sites in the DNA. The synergistic activity may consist of an inhibition of ATP synthesis and the simultaneous production of toxic amounts of ROS, destroying the mitochondria. Additionally, the sensitivity of the LNCaP cell line to the anthracyclines is relatively higher compared to the other two (PC-3, DU-145).     

盐酸表阿霉素与牛血清白蛋白的相互作用和伏安分析

应用线性扫描技术研究盐酸表阿霉素的电化学行为.结果表明,在pH 6.80的Tris-HCl缓冲溶液中,盐酸表阿霉素有一较灵敏的还原峰,Epc=-0.34 V(vs.SCE).加入牛血清白蛋白(BSA)后,盐酸表阿霉素的还原峰电流明显下降.据此,建立了BSA的电化学测定法.在最佳实验条件下,1.0×10-9～1.0×10-6 mol.L-1范围内,BSA浓度与盐酸表阿霉素的峰电流下降值△ip呈线性关系(R=0.9973),BSA检出限达8.05×10-10 mol.L-1.盐酸表阿霉素与BSA的结合比为1,结合常数β为3.04×106 L.mol-1.     

Ursolic Acid Enhances the Sensitivity of MCF-7 and MDA-MB-231 Cells to Epirubicin by Modulating the Autophagy Pathway

Breast cancer is the leading cause of cancer death among women in the world, and its morbidity and mortality are increasing year by year. Epirubicin (EPI) is a commonly used drug for the treatment of breast cancer but unfortunately can cause cardiac toxicity in patients because of dose accumulation. Therefore, there is an urgent need for new therapies to enhance the sensitivity of breast cancer cells to EPI. In this study, we found ursolic acid (UA) can significantly improve the drug sensitivity of human breast cancer MCF-7/MDA-MB-231 cells to EPI. Next, we observed that the co-treatment of UA and EPI can up-regulate the expression of autophagy-related proteins Beclin-1, LC3-II/LC3-I, Atg5, and Atg7, and decrease the expression levels of PI3K and AKT, which indicates that the potential mechanism should be carried out by the regulating class III PI3K(VPS34)/Beclin-1 pathway and PI3K/AKT/mTOR pathway. Furthermore, we found the autophagy inhibitor 3-methyladenine (3-MA) could significantly reverse the inhibitory effect of co-treatment of UA and EPI on MCF-7 and MDA-MB-231 cells. These findings indicate that UA can dramatically enhance the sensitivity of MCF-7 and MDA-MB-231 cells to EPI by modulating the autophagy pathway. Our study may provide a new therapeutic strategy for combination therapy.     

盐酸表柔比星与核酸相互作用的共振瑞利散射光谱研究及其分析应用

用共振瑞利散射光谱研究了盐酸表柔比星(EPI)与小牛胸腺DNA(ctDNA)、鲑鱼DNA(sDNA)、鲱鱼精DNA(hsDNA)和酵母RNA(yRNA)等核酸之间的相互作用. 实验表明在pH 2.0左右的酸性介质中, 表柔比星及核酸本身的共振瑞利散射(RRS)均十分微弱, 但是当它们相互作用形成结合产物时, 将导致RRS增强并出现新RRS光谱. 不同核酸与表柔比星结合产物的RRS 光谱特征略有差异, 散射增强程度则各不相同, 其相对散射强度的顺序是ctDNA≈sDNA＞hsDNA＞yRNA . 在一定范围内核酸浓度与散射强度成正比, 据此可以建立一种新的用表柔比星测定DNA的 RRS 法, 方法具有高灵敏度, 对于不同DNA 其检出限(3s)在24.0 ng/mL 至28.0 ng/mL 之间, 用于合成样品分析, 结果满意. 文中还研究了适宜的反应条件, 影响因素和结合产物的分析化学性质. 结合吸收光谱和荧光光谱特征对表柔比星与DNA 的反应机理进行了讨论.     

Fabrication of a single-walled carbon nanotube-modified glassy carbon electrode and its application in the electrochemical determination of epirubicin

In the presence of dicetyl phosphate (DCP), a kind of surfactant with two long carbon–hydrogen chains, insoluble single-walled carbon nanotube (SWNT) was successfully dispersed into water. A uniform and very stable SWNT–DCP aqueous suspension was achieved, and then a SWNT-film-modified glassy carbon electrode (GCE) was easily fabricated via water-evaporation. The SWNT-modified GCE was characterized and its application in the electrochemical determination of epirubicin was described.