Reaction catalyzed by NADPH:quinone reductase (1.6.5.5)
2
+
NADPH
+
=
2
+
NADP+
2 5-hydroxy-1,4-naphthoquinone
+
NADPH
+
H+
=
2 5-hydroxy-1,4-naphthosemiquinone
+
NADP+
