Cyclic N-Acetyl-D-mannosamine is a monosaccharide used as a precursor in the chemical or enzymatic synthesis of neuraminic acid found in glycolipids and glycoproteins.N-Acetyl-D-mannosamine is a specific substrate for the synthesis of n -acetylneuraminic acid, an essential precursor for bacterial podoplanar polysialic acid (PA).N-Acetyl-D-mannosamine is used in the synthesis of sialic acid. mannosamine is used in the synthesis of sialic acid. It is also an intermediate in the synthesis of many carbohydrate-derived bioactive compound families and drug candidates.N-Acetyl-D-mannosamine is used in the study of cognitive disorders and aging.