The present invention relates to compounds of the general formula (I) which are inhibitors of purine muclioside phosphorylases (PNP), purine phosphoribosyltransferases (PPRT), 5'-methylthioadenosine phosphorylases (MTAP), 5'-methylthioadenosine mucliosidases (MTAN) and/or nucleoside hydrolases (NH). The invention also relates to the use of these compounds in the treatment of diseases and infections including cancer, bacterial infections, protozoal infections, and T-cell mediated disease and to pharmaceutical compositions containing the compounds.