荧光法研究槲皮素与β-环糊精及其衍生物的包合作用

Study on the complexation of quercetin with β-Cyclodextrin and its derivatives by fluorescence spectroscopy

目的详细研究槲皮素与环糊精在溶液中的包合行为并探讨影响包合的因素。方法采用荧光光谱法系统研究水溶液中槲皮素与β-CD、HP-β-CD和DM-β-CD的包合作用,并考察溶液酸度和环糊精种类等对包合过程的影响,探讨包合机理。结果槲皮素与环糊精在溶液中存在包合作用,其与三种环糊精的包合比均是1:1,包合强度依次是HP-β-CD>DM-β-CD>β-CD。在中性或酸性(pH6.5)条件下,环糊精最适宜包合槲皮素。结论环糊精衍生物比母体环糊精具有更好的包合能力,且环糊精更适合包合槲皮素的中性型体。

Objective To investigate the inclusion behavior between quercetin（QUE）and cyclodextrins,and to elucidate the factors which influence the inclusion complexes.Methods The inclusion complexes of QUE with CDs including β-CD,HP-β-CD and DM-β-CD have been investigated using the method of fluorescence systematicaly.The stoichiometric ratio and the inclusion constants（K）were estimated from spectrofluometric titrations.The effect of pH and kinds of CDs was also assessed as well as the inclusion mechanism.Results Inclusion complexes were formed in aqueous solution between QUE and CDs,and the stoichiometric ratio of the three complexes was found to be 1：1.The inclusion constants showed that HP-β-CD provided the maximum inclusion ability,followed by DM-β-CD and β-CD.And maximum inclusion ability of β-CDs was measured in the case of pH 6.5 in this system.Conclusion Cyclodextrin derivatives provided better complexation abilities compared to the parental β-CD,and β-CDs were more suitable for inclusion of the neutral form of QUE.