Carboxylic acid functionalized cobalt(iii) cyclen complexes for catalytic hydrolysis of phosphodiester bonds

Abstract

4-(1,4,7,10-Tetraazacyclotetradec-1-yl)methylbenzoic acid (cycmba, 1) has been synthesized, as a step towards the eventual development of sequence-specific hydrolytic complexes. A cobalt(III) complex of 1, [Co(cycmba)Cl₂]Cl·1.5H₂O (2·1.5H₂O) was found to be active against both an activated phosphodiester compound, bis(nitrophenyl)phosphate (BNPP), and supercoiled DNA. The presence of the benzoate group depresses the rate of hydrolysis of the ligand–Co(III) system at neutral pH, as confirmed by the kinetics results of a methyl ester analog. The ability of (2·1.5H₂O) to bind to solid substrates and remain active was also demonstrated by attachment of the molecule to agarose beads.