(2S)-2-[2-[3-[[4-[[[(2R,3S,4R,5R)-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]amino]propanoylamino]ethylsulfanylcarbonyl]propanoic acid