UDP‐GlcNAc analogues as inhibitors of O‐GlcNAc transferase (OGT): Spectroscopic, computational, and biological studies

A series of glycomimetics of UDP-GlcNAc, in which the β-phosphate has been replaced by either an alkyl chain or a triazolyl ring and the sugar moiety has been replaced by a pyrrolidine ring, has been synthesized by the application of different click-chemistry procedures. Their affinities for human O-GlcNAc transferase (hOGT) have been evaluated and studied both spectroscopically and computationally. The binding epitopes of the best ligands have been determined in solution by means of saturation transfer difference (STD) NMR spectroscopy. Experimental, spectroscopic, and computational results are in agreement, pointing out the essential role of the binding of β-phosphate. We have found that the loss of interactions from the β-phosphate can be counterbalanced by the presence of hydrophobic groups at a pyrroline ring acting as a surrogate of the carbohydrate unit. Two of the prepared glycomimetics show inhibition at a micromolar level.We thank for their support of our programs: MINECO (Madrid, Spain), the FEDER Program (Project CTQ2016-76155-R), and the Government of Aragon (Group E-10) to P.M; a Wellcome Investigator Award (110061) to DMFvA, and the University of Ferrara (FAR2016) to D.P. and M.F. M.G. thanks the MECD for an FPU pre-doctoral grant. D.S. thanks the CSIC for a JAE-Pre pre-doctoral grant. KR is funded by a BBSRC Studentship (1416998)Peer reviewe