(6R)-Tetrahydrobiopterin hydrochloride 4(1H)-Pteridinone, 5,6,7,8-tetrahydro-2-amino-6-(1,2-dihydroxypropyl)-, dihydrochloride, (6R-(6R*(1R*,2S*)))- 69056-38-8 SUN 0588 Sapropterin dihydrochloride Sapropterin hydrochloride