D-mannose is an organic compound with a molecular formula of C6H12O6 and a molecular weight of 180.156. It is a colorless or white crystalline powder. D-mannose is a carbohydrate that plays an important role in the process of human metabolism, especially in the glycosylation of specific proteins.

D-mannose can be prepared by the hydrolysis of glycans rich in D-mannose (ivory palm seeds, yeast mannans, etc.). It can also be synthesized from D-mannitol (a by-product of the kelp iodine industry) in the presence of ferrous ions with hydrogen peroxide. It can also be prepared by D-glucose epimerization, or the carbon chain growth of D-arabinose.
A simple sugar. It is a component of a variety of polysaccharides. Exist in a free state in some plant peels, such as citrus peels, a small amount of free mannose in fruits such as peaches and apples, and ivory palm seeds, yeast, red algae, serum globulin, ovomucoid, and Mycobacterium tuberculosis Glycan containing D-mannose
D-mannose, the only glyconutrient used clinically, D-mannose is widely distributed in body fluids and tissues, especially in the nerves, skin, testes, retina, liver and intestines. It is directly used to synthesize glycoproteins and participate in immune regulation. Many diseases are caused by the lack of enzymes in mannose glycation.