133310-38-0 2,6-Diamino-4-oxo-5-formamidopyrimidine 2,6-diamino-4-hydroxy-5-formamidopyrimidine Fapy guanine Fapy-G Fapygua Formamide, N-(2,6-diamino-4,5-dihydro-4-oxo-pyrimidinyl)-