Artificial Metallooxidases from Cyclodextrin Diacids

Unprecedented simple artificial metalloenzymes were made from cyclodextrin diacids. Six alpha- and beta-cyclodextrin diacids were prepared and their metal-binding and acid properties were investigated. The diacids formed fairly stable complexes with copper, zinc, and iron, with dissociation constants of 0.4-8x10(-4) m. The iron complexes were found to catalyse a Fenton-like oxidation reaction of benzylic alcohols, which displayed Michaelis-Menten catalysis and rate accelerations up to 2700.