Synthesis and biological evaluation of new pyrazole- and tetrazole-related C-nucleosides with modified sugar moieties

3(5)-Carboxamido-4-(β-d-ribofuranosyl)pyrazoles bearing 2′-benzamido () and 3′-mesyloxy () isosteric groups, as well as the tetrazole C-nucleosides with 2-benzamido-2-deoxy-β-d-ribofuranose () and 3-azido-3-deoxy-β-d-xylofuranose () as sugar segments, have been synthesized starting from d-glucose, by utilizing the 2,5-anhydro-d-glucose ethylene acetal derivatives and as divergent intermediates. The C-nucleosides and were shown to be moderate inhibitors of the in vitro growth of both N2a and BHK 21 tumour cell lines, whereas showed a selective, although not potent cytotoxic activity against N2a cells. Compound also showed a moderate in vitro antiviral activity towards the rabies virus.