One- and two-step enzymatic synthesis of polymerizable vinyladipoyl mono- and diesters of non-reducing trisaccharides

The enzymatic transesterification of non-reducing trisaccharides raffinose and melezitose with divinyl adipate using two lipases (Novozym 435, Lipozyme TL IM) and the protease subtilisin Carlsberg is described. Polymerizable vinyladipoyl sugar esters were obtained with good to excellent selectivity and high yields. Monoesters prepared with lipase catalysis have also been used as substrates for a second acylation step catalyzed by the protease. Diesters were obtained with high selectivity although the isolated yields were slightly lower than those obtained for the corresponding monoester derivatives. It is important to note that the preferential acylation positions for subtilisin are the same in the free sugar and in the corresponding used monoesters for both trisaccharides. This two-step enzymatic approach allows regioselective control in the incorporation of the sugar inside the polymer structure.