Bioactive nucleoside analogues possessing selected five-membered azaheterocyclic bases

The review summarizes literature reports on nucleoside analogues containing five-membered aglycones based on imidazole-4-carboxamide (X = Y = CH), 1,2,4-triazole-3-carboxamide (X = CH, Y = N) or 1,2,3-triazole-4-carboxamide (X = N, Y = CH) structural motifs with modifications (a-c), which exhibit diverse therapeutically useful or promising biological activities.