STRUCTURAL-ANALYSIS OF LAMINARANS BY MALDI AND FAB MASS-SPECTROMETRY

MALDI and FAB mass spectrometry were applied to eight samples of lamin arans from different algal species. The existence of both M-chains (ma nnitol-containing) and G-chains (mannitol-free) was confirmed for six of them, as well as the absence of M-chains for laminarans from two Cy stoseira sp. It was found that Cystoseira barbata and C. crinita gluca ns contain a small percentage of N-acetylhexosamine-terminated chains. This is the first observation of nitrogen-containing sugars in lamina rans. The presence of cyclic structures in some laminaran samples is s uggested by the MALDI and FAB data. This study demonstrates the power of modern mass spectrometry for defining d.p. profiles in complex mixt ures of polysaccharides and for rapidly and sensitively revealing the presence of novel components. (C) 1998 Elsevier Science Ltd. All right s reserved.