In enzymology, mannitol dehydrogenase (cytochrome) () is an enzyme that catalyzes the chemical reaction
The substrate of this enzyme is D-mannitol, which is acted on by two equivalents of the cofactor, ferricytochrome c, which oxidises one of the hydroxy groups to a keto group, giving D-fructose, while the cofactor's iron is reduced.
This enzyme belongs to the family of oxidoreductases, to be specific those acting on the CH-OH group of donor with a cytochrome as acceptor. The systematic name of this enzyme class is D-mannitol:ferricytochrome-c 2-oxidoreductase. This enzyme is also called polyol dehydrogenase. This enzyme participates in pentose and glucuronate interconversions and fructose and mannose metabolism