| abstract |
A compound of the formula: nwherein B is a purin-9-yl group or a heterocyclic isostere of a purin-9-yl group; or a pyrimidin-1-yl group or a heterocyclic isostere of a pyrimidin-1-yl group; A is -CH- or A-G taken together is -C(=O)-, -C(=CH₂)-, -C(OH)(CH₂OH)- or nand G and D are functional groups; or a pharmaceutically acceptable salt or ester thereof. |