Terekhova Irina V
Institute of Solution Chemistry of Russian Academy of Sciences, 1 Akademicheskaya Str., Ivanovo, Russian Federation.
Curr Drug Discov Technol. 2008 Jun;5(2):168-72. doi: 10.2174/157016308784746201.
The effect of native and hydroxypropylated beta-cyclodextrin on the solubility and activity of some purine alkaloids was examined. For this purpose, the solubility of purine alkaloids in pure water and in aqueous solutions of mentioned beta-cyclodextrins was determined at 298.15 K. Stability constants of inclusion complexes and their stoichiometry were obtained from solubility diagrams. Enthalpic characteristics of interactions occurring between beta-cyclodextrins and purine alkaloids in aqueous solution were calculated from the direct calorimetric measurements. It was found, that beta-cyclodextrin forms with purine alkaloids weak complexes which are stabilized only by the entropy term. Due to very low complexing affinity of both beta-cyclodextrins to studied purine alkaloids their solubilizing effect is insignificant. The influence of structure of purine alkaloids and beta-cyclodextrin on the thermodynamic parameters of interaction was discussed.
研究了天然β-环糊精和羟丙基化β-环糊精对某些嘌呤生物碱溶解度和活性的影响。为此，在298.15 K下测定了嘌呤生物碱在纯水以及上述β-环糊精水溶液中的溶解度。从溶解度图中获得包合物的稳定常数及其化学计量比。通过直接量热测量计算了β-环糊精与嘌呤生物碱在水溶液中相互作用的焓特性。结果发现，β-环糊精与嘌呤生物碱形成弱络合物，这些络合物仅通过熵项得以稳定。由于两种β-环糊精对所研究的嘌呤生物碱的络合亲和力非常低，它们的增溶作用微不足道。讨论了嘌呤生物碱和β-环糊精的结构对相互作用热力学参数的影响。
