Suggested Reaction 1.1.4.-

Left

13(1)-Oxo-Mg-protoporphyrin IX 13-monomethyl ester
+1,4-Dithiothreitol

Right

13(1)-Hydroxy-Mg-protoporphyrin IX 13-monomethyl ester
+Oxidized dithiothreitol

[BiSSCat | GREP ]