摘要
Enzymatic synthesis of para-lacto-N-hexaose and its isomeric structures as well as those α1,2-fucosylated variants naturally occurring in human milk oligosaccharide (HMOs) was achieved using a sequential one-pot enzymatic system. Three glycosylation routes comprising bacterial glycosyltransferases and corresponding sugar-nucleotide-generating enzymes were developed to facilitate efficient production of extended type-1 and type-2 N-acetyllactosamine (LacNAc) backbones and hybrid chains. Further fucosylation efficiency of two α1,2-fucosyltransferases on both type-1 and type-2 chains of the hexasaccharide was investigated to achieve practical synthesis of the fucosylated glycans. The availability of structurally defined HMOs offers a practical approach for investigating future biological applications. (Figure presented.).