| Abstract
| - (6AR,6DR)-6A,6D-Di-C-cyano-β-cyclodextrin (1) and 6A,6D-di-C-cyano-α-cyclodextrin (2) were synthesized and shown to catalyze hydrolysis of aryl glycosides into glucose and phenol with a reactionfollowing Michaelis−Menten kinetics. At pH 8.0 and 59 °C hydrolysis of 4-nitrophenyl α-glucopyranoside was catalyzed by 1 with KM = 10.5 ± 1.5 mM, kcat = 1.42(±0.09) × 10-4 s-1, and kcat/kuncat= 7922. Catalysis was observed with a concentration of 1 as low as 10 μM. Hydrolysis of the otheraryl glycosides containing stereochemical variation in the sugar-moiety and 4-nitro-, 2-nitro-,2-aldehydo-, and 2,4-dinitro- were also catalyzed by 1 and 2 with kcat/kuncat ranging from 4 to 7100.Hydrolysis of a phenyl β-d-glucoside or the thioglycoside tolylthio β-d-glucoside was also catalyzed.From a series of prepared analogues of 1 it was found that the catalysis was associated with thehydroxyl groups α to the nitril groups. The monocyanohydrin 6-C-cyano-β-cyclodextrin (3) was alsofound to catalyze the hydrolysis of 4-nitrophenyl β-glucopyranoside with kcat/kuncat = 1356. It wasproposed that the cyclodextrin cyanohydrins 1−3 catalyze the hydrolysis by general acid catalysison the bound substrate.
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