通过对溶于氘代二甲亚砜（DMSOd6）中的槲皮素的自扩散系数和槲皮素羟基质子与溶剂中水质子之间的交换速率常数的NMR测量,研究了交换速率常数与扩散系数随温度和含水量的变化情况.结果表明,化学交换与扩散系数是相互独立的两种运动,活泼质子的化学交换并不需要通过槲皮素分子的扩散而进行.但是活泼质子的表观扩散系数却显著地受化学交换的影响.当以活泼质子为对象时,这种影响需要引起足够的重视.%The exchange rate constants of the labile protons in quercetin with water and the self diffusion coefficients of quercetin in DMSO d6 solutions with different water concentrations and at different temperatures are studied. When the water concentration or the temperature is changed,both exchange rates and diffusion coefficients are changed,but there is no correlation between these two changes. This indicates that chemical exchange of the labile protons with water and self diffusion of the quercetin molecule are two independent motions in solutions and chemical exchange is not controlled by diffusion. However,the apparent self diffusion coefficients of the labile protons are obviously affected by chemical exchange.
展开▼
