(S)-alpha-((4-(((2,4-Diamino-6-pteridinyl)methyl)amino)benzoyl)amino)-1H-tetrazole-5-butanoic acid 127134-21-8 1H-Tetrazole-5-butanoic acid, alpha-((4-(((2,4-diamino-6-pteridinyl)methyl)amino)benzoyl)amino)-, (S)- Tetrazole-aminopterin gamma-Tetrazole-aminopterin