Suggested Reaction 1.3.1.-

Left

Retinal
+NAD+

Right

(all-E)-3,7-Dimethyl-9-(2,6,6-trimethyl-1,3-cyclohexadien-1-yl)- 2,4,6,8-nonatetraenal
+NADH
+H+

[BiSSCat | GREP ]