3'-Azido-3'-deoxythymidine 3'-Azidothymidine 3'-Deoxy-3'-azidothymidine 30516-87-1 AZT Azidothymidine Azitidin BW-A 509U NSC602670 Retrovir Thymidine,3'-azido-3'-deoxy- Timazid ZDV Zidovudine