in addition , the sialic acids already known to occur in this tissue , namely n-acetylneuraminic acid , n-acetyl-7-o-acetylneuraminic acid , n-acetyl-9-o-acetylneuraminic acid , n-acetyl-7,9-di-o-acetylneuraminic acid , n-glycoloylneuraminic acid , and n-glycoloyl-9-o-acetylneuraminic acid could be identified .
C0037025
sialic
C0067762
n