Microbial natural products have always performed a prominent role in the history of drug discovery and development [1].These secondary metabolites have a remarkable range of biological activities which are mainly caused by their complicated scaffolds and different functional groups [2].Various modification reactions are involved in the biosynthesis of these bioactive natural products,which can be divided into three different stages:namely pre-assembly modification,assembly line modification,and post-assembly modification.Undoubtedly,post-modification is often the most important modification that contributes to the structural diversity and good biological activities of most natural products,including redox,methylation,glycosylation,acetylation,prenylation,halogenation,etc.[3].In addition to traditional approaches for natural product discovery,combinatorial biosynthesis methods can also generate new derivatives with improved properties [3].In recent years,remarkable efforts have been carried out on both normal and unusual sugars,since they have a profound impact on the properties of the bioactive natural products [4].Therefore,it is meaningful to develop some combinatorial biosynthetic approaches which can modify the sugar moieties and generate novel glycosylated derivatives.