139110-80-8 4-Guanidino-NeueAc2en 5-Acetamido-2,6-anhydro-3,4,5-trideoxy-4-guanidino-D-glycero-D-galacto-non-2-enonic acid AIDS-070984 AIDS070984 GG167 GR121167X Relenza Zanamavir Zanamivir