STEREOCHEMISTRY OF THE HYDROLYSIS OF α,α-TREHALOSE BY TREHALASE, DETERMINED BY USING A LABELLED SUBSTRATE

Article abstract of DOI:10.1016/0008-6215(83)88462-6

(1,1'-13C)α,α-Trehalose was obtained in 37percent yield from the Pavia condensation of 2,3,4,6-tetra-O-benzyl-D-(1-13C)glucopyranose, in dichloromethane in the presence of trifluoromethanesulfonic anhydride, followed by the usual deprotection tecniques.The hydrolysis of this substrate by cockchafer trehalase was monitored at 37 deg by using 13C-n.m.r. spectroscopy with short recording times.Equimolecular amounts of α- and β-D-glucopyranose are released simultaneously by the action of the enzyme.This result is consistent with a bimolecular substitution mechanism, taking into account previous results involving C-2 asymmetric participation in the catalytic step of hydrolysis of α,α-trehalose.For comparative evaluation of its accuracy, the usual polarimetric technique was also used for the determination of the anomeric configuration of the D-glucose released by the action of the enzyme on α,α-trehalose.