[(2R)-4-[(2-{3-[(2R)-4-{[(S)-({[(2S,3R,4R,5R)-5-(6-amino-9H-purin-9-yl)-4-hydroxy-3-(phosphonooxy)oxolan-2-yl]methoxy}(hydroxy)phosphoryl phosphonato)]oxy}-2-hydroxy-3,3-dimethylbutanamido]propanamido}ethyl)sulfanyl]-2-hydroxy-4-oxobutyl]trimethylazanium