Glycosyl benzoates as novel substrates for glycosynthases

The development of a procedure for the one-pot synthesis of glycosyl benzoates directly from unprotected sugars in aqueous media using 2-chloro-1,3-dimethylimidazolium chloride (DMC), thiobenzoic acid, and triethylamine is reported. These glycosyl donors are excellent substrates for wild-type and mutant glycosidases. & beta;-Glucosyl benzoate was hydrolysed by the GH1 & beta;-glucosidase derived from Halothermothrix orenii (HorGH1). Subsequent use of this substrate in thioligase-mediated glycosylation of p-nitrothiophenol demonstrated their superiority as donors compared to their p-nitrophenol counterparts with excellent conversions. Using a series of arene nucleophiles, we also demonstrate good to excellent conversions (up to 94%) of & beta;-glucosyl benzoate to the corresponding p-nitrophenyl- and thioglycosides.

Automated summary

A one-pot synthesis method for glycosyl benzoates from unprotected sugars in water using 2-chloro-1,3-dimethylimidazolium chloride, thiobenzoic acid, and triethylamine was developed. These glycosyl donors were found to be excellent substrates for both wild-type and mutant glycosidases. The hydrolysis of β-glucosyl benzoate by the GH1 β-glucosidase from Halothermothrix orenii was demonstrated, and the donor's superiority in thioligase-mediated glycosylation was shown with high conversions.