β-Cyclodextrin attached with metal complex as catalyst for the cleavage of rebonucleoside cyclic phosphates and ribonucleotide dimers

Abstract

The 2',3'-cyclic monophosphates of ribonucleosides are efficiently cleaved by the 1:1 complex between modified β-cyclodextrin ( I) bearing a diethylenetriamine residue at the primary hydroxyl side and Zn(II) ion. The magnitude of the acceleration is highly dependent on the kind of ribonucleoside, with the largest effect on adenosine cyclic phosphate (2300 and 440 fold accelerations at pH 7 and 8 respectively). The catalysis involves formation of a complex between the I-Zn 2+ complex and the substrate, followed by nucleophilic attack either by hydroxide ion bound to the Zn(II) ion, by free water, or by free hydroxide ion. Cleavage of ribonucleotide dimers is also catalyzed by the I-Zn 2+ complex.