In enzymology, mannitol 2-dehydrogenase (NADP<sup>+</sup>) () is an enzyme that catalyzes the chemical reaction
The two substrates of this enzyme are D-mannitol and oxidised nicotinamide adenine dinucleotide phosphate (NADP<sup>+</sup>). Its products are D-fructose (shown in its open-chain form), reduced NADPH, and a proton.
This enzyme belongs to the family of oxidoreductases, specifically those acting on the CH-OH group of donor with NAD<sup>+</sup> or NADP<sup>+</sup> as acceptor. The systematic name of this enzyme class is D-mannitol:NADP<sup>+</sup> 2-oxidoreductase. This enzyme is also called mannitol 2-dehydrogenase (NADP<sup>+</sup>). This enzyme participates in fructose and mannose metabolism.
As of late 2007, only one structure has been solved for this class of enzymes, with the PDB accession code .