Definition of ketoses

1. Ketonic parent sugars (polyhydroxy ketones H-[CHOH]n-C(=O)[CHOH]m-H with three or more carbon atoms) and their intramolecular hemiacetals. 2-Carb-1.2. The oxo group is usually at C-2. See also monosaccharides . E.g. D-fructose