Suggested Reaction 1.1.4.-

Left

3,5,7,9,11,13,15,17-Octaoxo-nonadecanoyl-[acp]
+1,4-Dithiothreitol

Right

9-Hydroxy-3,5,7,11,13,15,17-octaoxo-nonadecanoyl-[acp]
+Oxidized dithiothreitol

[BiSSCat | GREP ]