A practical synthesis of capped 4-methylumbelliferyl hyaluronan disaccharides and tetrasaccharides as potential hyaluronidase substrates

The synthesis of hyaluronan dimers and tetramers equipped with a 4-methylumbelliferyl group at the reducing end to potentially allow monitoring of hyaluronidase activities is described. The 4-OH at the non-reducing glucuronate in the presented series is either removed or methylated to prohibit transglycosylase reactions, leading to a total of four probes.