Large Acceleration Effects of Mono-6-(alkylamino)-￥a-cyclodextrins on the Cleavage of p-Nitrophenyl ￥á-Methoxyphenylacetate

摘要

Kinetic studies of the deacylation reactions of p-and m-nitrophenyl esters of (R or S)-メ -methoxyphenylacetic acid were performed in モ -CD, mono-6-deoxy-6-[N-(2-aminoethyl)]amino-モ -CD (モ-CDen) and mono-6-deoxy-6-[N-(2-aminoethyl)-2-aminoethyl] amino-モ-CD (モ-CDdien) media. The binding constants (K) of the substrates to the hosts and the rate constants (kCD) for the complexed substrates were determined. kCD values are highly dependent on the hosts and the substrates, whereas differences in K values among them are modest. The p-nitrophenyl esters show larger acceleration by モ-CDen and モ-CDdien than the corresponding m-isomers, while the m-isomers are more reactive than the p-isomers in モ-CD media. This is taken as an indication that the amino groups attached to the primary side of モ-CD participate in the deacylation reaction.