转铁蛋白偶联双氢青蒿素氧基苯甲酰肼的载药量分析

Analysis of Drug Holding of Dihydroartemisininoxy Benzoic Acid Hydrazide Tagged to Holotransferrin

在含20%乙醇的B-R缓冲溶液(V/V,pH=7.2)中,利用电分析化学方法测得双氢青蒿素氧基苯甲酰肼(dihydroartemisininoxy benzoic acid hydrazide,DBAH)在银电极上于-0.66V(vs.SCE)处有一不可逆还原峰。DBAH与被高碘酸钠氧化后的转铁蛋白(holotransferrin,Tf)结合形成电活性复合物,其还原峰峰电位由-0.16V负移至-0.84V,峰电流随DBAH和Tf浓度的增加而增加。该法测得一个Tf分子可以与3个DBAH分子连接,其结合常数为5.1×1010。紫外可见吸收光谱法测定结果与电化学测定结果相吻合。实验结果表明,Tf与DBAH共价结合形成电活性复合物。

There was an irreversible reductive peak at-0.66 V（vs.SCE） for dihydroartemisininoxy benzoic acid hydrazide（DBAH） at Ag electrode B-R buffer solution containing 20% ethanol（V/V,pH 7.2） using electroanalytical chemistry method.The reductive peak of DBAH shifted negatively to-0.84 V in the presence of holotransferrin（Tf） which indicated an electrochemical active complex was forming.The peak current of the complex increased with the concentration of DBAH and Tf respectively increasing.The result of electrochemical determination showed that one Tf molecule could tag with three DBAH molecules,the combinative constant of the complex was 5.1×10^10.This result was also validated via UV-vis absorption spectroscopy.It was showed that DBAH and Tf could bind by covalent bonds and form an electrochemical active complex which can be determined by the above mentioned methods.