1,4-Dihydroisonicotinic acid 4-Carboxypyridine 4-Picolinic acid 4-Pyridinecarboxylic acid 55-22-1 AI3-19239 Acide iso-nicotinique [French] EINECS 200-228-2 INA ISONICOTINIC ACID NSC 1483 gamma-Picolinic acid gamma-Pyridinecarboxylic acid p-Pyridinecarboxylic acid