Synthesis and enzymatic degradation of randomly substituted 2,3,6-O-cellulose acetate and regioselectively substituted 2,3-O-cellulose acetate

To investigate the effect of substitution site on enzymatic degradation property of cellulose acetate (CA), randomly substituted 2,3,6-O-CA (DS = 0.4, 1.2, and 2.1) and regioselectively substituted 2,3-O-CA (DS = 0.4, 1.3, and 2.0) were synthesized without or with using trytyl group for C6 protection process. Both 2,3,6-O-CA and 2,3-O-CA were submitted to enzymatic degradation test using cellulase from Toricoderma reesei. The concentration of hydrolytic products was analyzed by the reducing sugar analyses using glucose standards. CAs with lower DS (0.4) were more hydrolyzed compared to CAs with higher DS (1.2 or 1.3) and CAs with DS over 2 were not hydrolyzed regardless of substitution site. The degradability of 2,3-O-CAs (DS = 0.4 and 1.3) turned out to be higher than that of 2,3,6-O-CAs (DS = 0.4 and 1.2). The hydrolytic products of 2,3,6-O-CA and 2,3-O-CA were analyzed by HPLC and the relationship between their substitution site and the enzymatic degradation behavior was discussed in detail.