The molecule is a branched amino heptasaccharide consisting of a linear chain of an alpha-D-mannose residue, a beta-D-mannose residue and two N-acetyl-beta-D-glucosamine residues linked sequentially (1->6), (1->4) and (1->4), to the alpha-D-mannose residue of which are linked (1->3) and (1->2) alpha-D-mannose and beta-D-xylose residues respectively, while the N-acetyl-beta-D-glucosamine residue at the reducing end also carries an alpha-L-fucose residue via a (1->3) linkage. It forms the heptasaccharide portion of the N-glycan phytohemaglutinin (PHA). It has a role as a carbohydrate allergen. It is an amino heptasaccharide and a glucosamine oligosaccharide.
N-[(2S,3R,4R,5S,6R)-2-[(2R,3S,4R,5R,6R)-5-acetamido-6-hydroxy-2-(hydroxymethyl)-4-[(2S,3S,4R,5S,6S)-3,4,5-trihydroxy-6-methyloxan-2-yl]oxyoxan-3-yl]oxy-4-hydroxy-6-(hydroxymethyl)-5-[(2S,3S,4S,5R,6R)-5-hydroxy-4-[(2S,3S,4S,5S,6R)-3,4,5-trihydroxy-6-(hydroxymethyl)oxan-2-yl]oxy-6-[[(2S,3S,4S,5S,6R)-3,4,5-trihydroxy-6-(hydroxymethyl)oxan-2-yl]oxymethyl]-3-[(2S,3R,4S,5R)-3,4,5-trihydroxyoxan-2-yl]oxyoxan-2-yl]oxyoxan-3-yl]acetamide