149741-42-4 1H-Purine-2,6-dione, 3,7-dihydro-3-(2-(4-aminophenyl)ethyl)-8-(hexahydro-2,5-methanopentalen-3a(1H)-yl)-1-propyl- 3-(4-Aminophenethyl)-8-(3-noradamantyl)-1-propylxanthine