Chemoenzymatic n.c.a synthesis of the coenzyme UDP-2-deoxy-2-(18F)fluoro-alpha-D-glucopyranose as substrate of glycosyltransferases

The development of F-18-labelling methods adopted to proteins and bioactive peptides is of great interest in radiopharmaceutical sciences. In order to provide F-18-labelled sugars as a polar prosthetic group for an enzymatic 18 F-labelling procedure, an appropriate nucleotide activated sugar is needed. Here, we present the radiosynthesis of n.c.a. UDP-2-deoxy-2-[F-18]fluoro-alpha-D-glucopyranose (UDP-[F-18]FDG) as a substrate for glycosyltransferases. The MacDonald synthesis of [F-18]FDG-1-phosphate was successfully combined with an enzymatic activation to obtain UDP-[F-18]FDG directly in an aqueous medium located in the void volume of a solid phase cartridge. The radiochemical yield of UDP-[F-18]FDG was 20% (based on [F-18] fluoride) after a total synthesis time of 110 min. Thus, an intermediate was provided for the enzymatic transfer of [F-18]FDG using UDP-[ 18 F]FDG as glycosyl donor making use of a suitable glycosyltransferase. This would represent a highly selective and mild F-18-labelling method for glycosylated biomolecules. Copyright (c) 2007 John Wiley & Sons, Ltd