(-)-(6R)-2-Amino-6-((1R,2S)-1,2-dihydroxypropyl)-5,6,7,8-tetrahydro-4(3H)-pteridinone 27070-47-9 62989-33-7 6R-5,6,7,8-Tetrahydrobiopterin 6R-L-5,6,7,8-Tetrahydrobiopterin Sapropterin Sapropterin [INN] Sapropterina [INN-Spanish] Sapropterinum [INN-Latin]