Enzymatic synthesis of methyl β-d-glucoside directly from cellulose pretreated with biocompatible amino acid ionic liquid/cosolvent

Abstract

Abstract A new approach for the enzymatic synthesis of methyl β-d-glucoside was proposed, based on commercially available cellulase and cellulose pretreated with phosphonium-based amino acid ionic liquid/cosolvent. The pretreatments were quite effective and methyl β-d-glucoside was successfully synthesized with 40% yield from cellulose (Avicel) pretreated with tetrabutylphosphonium glycine/dimethyl sulfoxide (DMSO), whereas the yield was only 1.4% from untreated cellulose. Preparative-scale synthesis from 1 g cellulose with a reduced amount of cellulase was also conducted, achieving a 33% isolated yield. Results of additional studies with cellobiose and glucose as substrates have been interpreted as cellulose being first enzymatically hydrolyzed to cellobiose, which then reacted with methanol to produce methyl β-d-glucoside by transglycosylation.