5-Desamino-5-hydroxy-neuraminic acid or 2-keto-3-deoxy-nononic acid (Kdn) (Nadano et al., 1986)
is increasingly detected in microorganisms and animals.
Neuraminic acid itself (Neu), the de-N-acetylated
product of N-acetylneuraminic acid (Neu5Ac), is a
further component of mammalian glycoconjugates.