甲醛

5-去氮杂叶酸

N-(4-氨基苯(甲)酰)-L-谷氨酸二乙酯

2,4-diaminopyrido[2,3-d]pyrimidine-6-carbaldehyde

2-amino-4-oxo-1H-pyrido[2,3-d]pyrimidine-6-carbaldehyde