论文部分内容阅读
目的:研究盐酸倍他洛尔和β-环糊精包合物化学计量比、结构信息和稳定常数。方法:配制不同浓度比例盐酸倍他洛尔和β-环糊精混合溶液,测定了它们的1H NMR数据,绘制出Job’s曲线。并测定了包合物的二维ROESY和排序扩散谱(DOSY)数据。结果:盐酸倍他洛尔和β-环糊精的Job’s曲线拐点均在r=0.5处。1H NMR显示盐酸倍他洛尔的H-4’～H-8’包合后向高场位移。ROESY图谱的交叉峰信号出现在H-5’～H-8’和β-环糊精的H-3、H-5、H-6之间。DOSY获得了包合物的扩散系数。结论:盐酸倍他洛尔与β-环糊精形成了化学计量比1∶1的包合物。盐酸倍他洛尔由窄口端进入β-环糊精内部,H-4’至H-8’部分完全进入疏水空腔,其余部分在空腔外部。用β-环糊精的表观扩散系数近似代替包合物的扩散系数可方便地计算出包合物稳定常数,结果为153.2 M-1。
Objective: To study the stoichiometry, structure information and stability constants of betaxolol and β-cyclodextrin inclusion complexes. Methods: The mixed solutions of betaxolol and β-cyclodextrin were prepared at different concentrations, their 1H NMR data were measured and the Job’s curve was drawn. The two-dimensional ROESY and ordered diffuse spectra (DOSY) data of the inclusion complex were determined. Results: Job’s curve inflection point of both betaxolol and beta-cyclodextrin were all at r = 0.5. 1H NMR showed that H-4 ’~ H-8’ of betaxolol hydrochloride was shifted to high field after inclusion. The cross peak signal of the ROESY map appears between H-5 ’~ H-8’ and β-cyclodextrin between H-3, H-5 and H-6. DOSY obtained the diffusion coefficient of the inclusion complex. Conclusion: Betalool hydrochloride and β-cyclodextrin form a 1: 1 stoichiometry inclusion compound. Betalol hydrochloride enters the interior of β-cyclodextrin from the narrow end, and the H-4 ’to H-8’ part enters the hydrophobic cavity completely and the rest is outside the cavity. By using the apparent diffusion coefficient of β-cyclodextrin instead of the diffusion coefficient of the inclusion complex, the stability constant of the inclusion complex can be easily calculated, and the result is 153.2 M-1.