Studies of the macrolide glycosyltransferase, DesVII/DesVIII, showed that it can process a variety of linear substrates and cyclic substrates of different ring size. When multiple hydroxyl groups are present, no regiospecificity of glycosylation is observed for the linear substrates. In contrast, when cyclic substrates with multiple glycosylation sites were tested, it displayed excellent regiospecificity in most cases. These results clearly indicate that this enzyme pair is a valuable tool for glycodiversification.