(also sedoheptose), C7Hl4O7, a monosaccharide of the ketoheptose group. Sedoheptulose exists in the optically active D-and L-forms and also occurs as the racemate. The D-form is widely distributed in nature. Sedoheptulose takes part in the biosynthesis of monosaccharides in the leaves of green plants during photosynthesis and in carbohydrate metabolism in animal organisms (pentose-phosphate cycle).