Involved in the oxidation of myo-inositol (MI) to 2-keto-myo-inositol (2KMI or 2-inosose). myo-inositol + NAD(+) = H(+) + NADH + scyllo-inosose Polyol metabolism; myo-inositol degradation into acetyl-CoA; acetyl-CoA from myo-inositol: step 1/7. By myo-inositol. Belongs to the Gfo/Idh/MocA family.