三种抗癌嘌呤类化合物与环糊精作用的研究

采用荧光光度法 ,在考察了时间、酸度以及温度对包合物形成的影响后 ,利用荧光双倒数法分别计算出了巯嘌呤、硫唑嘌呤和 8 氮杂鸟嘌呤与 β 环糊精及羟丙基 β 环糊精的包合常数。实验表明 :时间和酸度对它们的包合有显著影响。β 环糊精形成稳定包合物的时间约在 3h左右 ,而羟丙基 β 环糊精的包合时间大约在 2h左右。最佳酸度在弱碱性范围 (pH =7 7)左右。它们的最大激发波长都在 2 76～ 2 85nm之间 ,最大发射波长较长 ,在 32 8～ 35 3nm之间。随着环糊精浓度增大 ,包合物的荧光都有增加趋势 ,且羟丙基 β 环糊精包结物的增强更为显著一些。3种黄嘌呤类衍生物与环糊精的包结物的包结比均为 1∶1。

A Study on Inclusion Complexes of Cyclodextrin with Three Anticancer Xanthines by Fluorescence

The inclusion complexes of beta-Cyclodextrin (beta-CD) and HP-beta-Cyclodextrin (HP-beta-CD) with 6-Mercaptopurine (6-MP), Azathioprine (BAN) and 8-Azaguanine (Azan) were investigated by fluorescence. Various factors affecting the formation of inclusion complexes were discussed in detail including formation time and pH effect. The formation constants of their inclusion complexes were determined. The results indicated that their inclusion was affected significantly by laying time and pH. The formation time of beta-CD inclusion complexes is much longer than that of HP-beta-CD. The optimum pH is about pH = 7.7-12. Their maximum excitation wavelengths are all in the range of 276-285 nm and the maximum emission wavelengths are all in the range of 328-353 nm. The fluorescence signals are intensified with increasing concentration of CD. The stoichiometries of the inclusion complexes of CD with these three anticancer xanthines are all 1:1 and the formation constants are calculated.