Synthesis of Three C-Glycoside Analogues of UDP-Galactopyranose as Conformational Probes for the Mutase-Catalyzed Furanose/Pyranose Interconversion

UDP-galactopyranose mutase (UGM) catalyzes the isomerization of UDP-galactopyranose (UDP-Galp) into UDP-galactofuranose (UDP-Galf), an essential step of the mycobacterial cell wall biosynthesis. In order to probe the UGM binding pocket, we synthesized the alpha- and beta-C-glycosidic analogues of UDP-galacopyranose along with the corresponding UDP-exo-galactal. Preliminary inhibition evaluation indicated that UDP-exo-galactal inhibits UGM with a binding affinity similar to that of UDP-alpha-C-galactopyranose. ((c) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)