pyrimidinemonocarboxylic acid organofluorine compound nucleobase analogue 5-fluoroorotic acid FO 1,2,3,6-tetrahydro-2,6-dioxo-5-fluoro-4-pyrimidinecarboxylic acid NSC 31712 5-fluoro-6-carboxyuracil A pyrimidinemonocarboxylic that is orotic acid which is substituted by fluorine at position 5. It is used in yeast molecular genetics to detect expression of the URA3 gene, which encodes orotine-5'-monophosphate dicarboxylase. A yeast with and active URA3 gene converts 5-fluoroorotic acid to fluorodeoxyuridine, which is toxic to cells. NSC-31712 CHEBI:74498 Ro 2-9945 5-fluorouracil-4-carboxylic acid FOA chebi_ontology 5-fluoro-1,2,3,6-tetrahydro-2,6-dioxo-4-pyrimidinecarboxylic acid ENT-26398