Synthesis and enzyme-catalyzed hydrolysis of a radical-masked glycosylated spin-label reagent

Abstract N 1 -Acetoxy-2,2,6,6-tetramethylpiperidin-4-yl 2,3,4,6-tetra- O -benzyl-α- and -β- d -glucopyranosides ( 3 -α, β) and N 1 -acetoxy-2,2,5,5-tetramethylpyrrolin-3-oyl 2,3,4,6-tetra- O -benzyl-α- and -β- d -glucopyranosylamines ( 9 -α, β) were synthesized in good yield by Schmidt’s glycosylation method. Their subsequent O-debenzylation was proceeded successfully to give the desired products 1 -α, and 1 -β in good yield, and 2 -α in a low yield, without 2 -β by only short-timed hydrogenolysis in the presence of palladium-on-carbon (Pd–C) in a CHCl 3 –MeOH solvent system that included concentrated HCl. Upon enzyme-catalyzed hydrolysis, only 2 -α was hydrolyzed by the esterase, while both of 1 -α and 1 -β were not hydrolyzed by any other enzyme such as lipase. These 2 -α can likely be used as a new water-soluble radical-masked glycosylated spin-label reagent.