4-[2-[3-[4-[[[5-(6-aminopurin-9-yl)-4-hydroxy-3-phosphonooxy-oxolan-2-yl]methoxy-hydroxy-phosphoryl]oxy-hydroxy-phosphoryl]oxy-2-hydroxy-3,3-dimethyl-butanoyl]aminopropanoylamino]ethylsulfanyl]-2-hydroxy-4-oxo-butanoic acid