In enzymology, sequoyitol dehydrogenase () is an enzyme that catalyzes the chemical reaction
The two substrates of this enzyme are sequoyitol and oxidised nicotinamide adenine dinucleotide (NAD<sup>+</sup>). Its products are 2D-5-O-methyl-2,3,5/4,6-pentahydroxycyclohexanone, reduced NADH, 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 5-O-methyl-myo-inositol:NAD<sup>+</sup> oxidoreductase. This enzyme is also called D-pinitol dehydrogenase.