22150-76-1 4(1H)-Pteridinone, 2-amino-6-(1,2-dihydroxypropyl)-, [S-(R*,S*)]- 4(3H)-Pteridinone, 2-amino-6-(L-erythro-1,2-dihydroxypropyl)- Biopterin L-Erythro-Biopterin NSC339699 Pterin H B2