The binding of C5-alkynyl and alkylfurano[2,3-d]pyrimidine glucopyranonucleosides to glycogen phosphorylase b: Synthesis, biochemical and biological assessment

► Novel C5-alkynyl & furano[2,3-d]pyrimidine nucleosides have been designed and synthesized. ► All compounds except two were low μM inhibitors of the enzyme. ► Three ligands induced significant conformational changes in the 280s loop. ► The most potent inhibitor was able to inhibit GPb activity in HepG2 cells in culture.