4-Amino-5-carboxy-2-hydroxy-pyrimidin, 4-Amino-2-oxo-1,2-dihydro-pyrimidin-5-carbonsaeure, 5-carboxylcytosine, 4-amino-2-hydroxypyrimidine-5-carboxylic acid, 4-amino-2-oxo-1,2-dihydropyrimidine-5-carboxylic acid, 6-amino-2-oxo-1H-pyrimidine-5-carboxylic acid, Cytosine-5-carboxylic acid, 5-Carboxy-cytosin, 4-Amino-2-hydroxy-5-pyrimidinecarboxylic acid, 4-amino-2-oxo-1,2-dihydro-5-pyrimidinecarboxylic acid