1 1D1 (7r)-8-cyclopentyl-7-ethyl-5-methyl-2-(1h-pyrrol-2-yl)-7,8-dihydropteridin-6(5h)-one 1.000 2 11G (7r)-8-cyclopentyl-7-ethyl-5-methyl-7,8-dihydropteridin-6(5h)-one 0.792