Patent ID: 7098334

Claim:
A compound of the formula (I): wherein: A is selected from CH and CR, where R is selected from halogen, alkyl, aralkyl, aryl, OH, NH 2 , NHR 1 , NR 1 R 2 and SR 3, where R 1, R 2 and R 3 are each alkyl, aralkyl or aryl groups; B is selected from NH 2 and NHR 4, where R 4 is an alkyl, aralkyl or aryl group; X is selected from H, OH and halogen; and Z is SQ, where Q is a C 2 –C 5 alkyl group; a C 2 –C 5 alkyl group substituted with a halogen; a phenyl group; or a phenyl group substituted with a halogen or a methyl; or a tautomer thereof; or a pharmaceutically acceptable salt thereof; with the proviso that the stereochemistry of the aza-sugar moiety is D-ribo or 2′-deoxy-D-erythro-.