N-Acetyllactosamine

beta-D-galactosyl-1,4-N-acetyl-D-glucosamine

N-Acetyllactosamine, or LacNAc, is a key disaccharide found as a repeating unit in many complex carbohydrates, including glycoproteins, glycolipids, and mucins. Its structure is Gal(β1-4)GlcNAc. This compound is a crucial building block for the synthesis of blood group antigens and other cell surface glycans, playing a fundamental role in cell-to-cell recognition.