Hydrolysis of toxic natural glucosides catalyzed by cyclodextrin dicyanohydrins

The hydrolysis of toxic 7-hydroxycoumarin glucosides and other aryl and alkyl glucosides, catalyzed by modified alpha- and beta-cyclodextrin dicyanohydrins, was investigated using different UV, redox, or HPAEC detection assays. The catalyzed reactions all followed Michaelis-Menten kinetics, and an impressive rate increase of up to 7569 (k(cat)/k(uncat)) was found for the hydroxycoumarin glucoside substrate 4-MUGP. Good and moderate degrees of catalysis (k(cat)/k(uncat)) of up to 1259 were found for the natural glucosides phloridzin and skim-min. By using a newly developed catechol detection UV-assay, a weak degree of catalysis was also found for the toxic hydroxycoumarin esculin. A novel synthesized diaminomethyl beta-cyclodextrin showed a weak catalysis of p-nitrophenyl beta-D-glucopyranoside hydrolysis. (C) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008.