2.4.6.8-Tetrahydroxy-pyrimido<5.4-d>pyrimidin(Oxyhomoharnsaeure), 1,5-dihydro-pyrimido[5,4-d]pyrimidine-2,4,6,8-tetraone, homouric acid, 1,5-dihydro-pyrimido[5,4-d]pyrimidinetetraone, 1,5-Dihydro-pyrimido[5,4-d]pyrimidintetraon, 1,5-dihydropyrimido[5,4-d]pyrimidine-2,4,6,8(3H,7H)tetrone, 2,4,6,8-Tetrahydroxypyrimido-[5,4-d]pyrimidine, 2,4,6,8-Tetraoxo-octahydro-pyrimido<5,4-d>pyrimidin