[(2S)-2-[[(2R)-3-[2,3-di(hexadecanoyloxy)propylsulfanyl]-2-[(2-methylpropan-2-yl)oxycarbonylamino]propanoyl]amino]-3-[3-[(2-methylpropan-2-yl)oxycarbonyl-[4-[(2-methylpropan-2-yl)oxycarbonyl-[3-[(2-methylpropan-2-yl)oxycarbonylamino]propyl]amino]butyl]amino]propylamino]-3-oxopropyl] 4-[[6-amino-2-(butylamino)-8-oxo-7H-purin-9-yl]methyl]benzoate