Protease-catalyzed monoacylation of 2-O-α-D-glucopyranosyl-L-ascorbic acid in pyridine

2-O-alpha -D-Glucopyranosyl-6-O-octanoyl-L-ascorbic acid was enzymatically synthesized from 2-O-alpha -D-glucopyranosyl-L-ascorbic acid (AA-2G) and vinyl octanoate with a protease from Bacillus subtilis in pyridine. Furthermore, with various linear saturated fatty acid vinylesters as acyl donors, AA-2G was also converted to their corresponding 6-O-acyl AA-2G in the same manner. The reactivities of transacylation decreased with increasing length of the acyl groups. Thus, short chain acyl groups were transferred to AA-2G by this protease more efficiently than were long chain acyl groups. This enzymatic method is recommended for the synthesis of 6-Acyl-AA-2G with short or medium length chain acyl groups.