Suggested Reaction 1.1.4.-

Left

6-(1,2-Dioxopropyl)-5,6,7,8-tetrahydropterin
+1,4-Dithiothreitol

Right

6-Lactoyl-5,6,7,8-tetrahydropterin
+Oxidized dithiothreitol

[BiSSCat | GREP ]