RAPID ANALYSIS OF O-ACETYLATED NEURAMINIC ACIDS BY MATRIX-ASSISTED-LASER-DESORPTION IONIZATION TIME-OF-FLIGHT MASS-SPECTROMETRY/

N-Acetylneuraminic acid (a sialic acid) occurs mainly as a terminal su bstituent of oligosaccharides of glycoconjugates. Derivatives of neura minic acid occur widely, substituted in the amino and hydroxy side cha ins, as well in the C-9 carbon skeleton. These derivatives are respons ible for specific functions of sialic acids during cell-cell, cell-sub strate, or cell-virus interactions. The study of O-acetylated neuramin ic acids is difficult, because only small amounts are extractable from natural sources and they are generally unstable to acids and bases. W e report a new method for the rapid analysis of O-acetylated neuramini c acids, using a combination of reversed phase HPLC and MALDI-TOF mass spectrometry. A mixture of neuraminic acids from bovine submaxillary gland mucins was analysed, as well as neuraminic acids variously subst ituted in the amino and hydroxy side chains with acetyl and glycolyl g roups, respectively.