Suggested Reaction 1.1.1.-

Left

6-Lactoyl-5,6,7,8-tetrahydropterin
+NADPH
+H+

Right

2-Amino-6-(1,2-dihydroxypropyl)-5,6,7,8-tetrahydoro-4(1H)- pteridinone
+NADP+

[BiSSCat | GREP ]