125291-17-0 6H-Purin-6-one, 2-amino-9-(2,3-dideoxy-3-fluoro-.beta.-D-threo-pentofuranosyl)-1,9-dihydro- 9-(2,3-Dideoxy-3-fluoro-.beta.-D-xylofuranosyl)guanine AIDS-001159 AIDS001159 ddFXG