CHARACTERIZATION OF NEUTRAL OLIGOSACCHARIDE-ALDITOLS FROM XENOPUS-LAEVIS EGG JELLY COATS BY MATRIX-ASSISTED LASER-DESORPTION FOURIER-TRANSFORM MASS-SPECTROMETRY

Neutral oligosaccharides were released by alkaline sodium borohydride reduction of the jelly coating from the South African clawed toad, Xen opus laevis. The oligosaccharides were isolated by HPLC and analyzed b y matrix-assisted laser desorption ionization (MALDI)-Fourier transfor m mass spectrometry (FTMS). The mass spectrometry analysis allowed con firmation of 12 structures first proposed hy Strecker et al. using nuc lear magnetic resonance, In addition, seven new oligosaccharides with weak abundances were found and characterized by mass spectrometry. A m ethod for discriminating metastable fragments from quasimolecular ions is described. It involves doping the sample with cesium chloride. Ces ium-coordinated oligosaccharides do not fragment as readily as those c oordinated to sodium. Tandem MS experiments are performed on an unknow n oligosaccharide illustrating the potential of MALDI-collision-induce d dissociation-FTMS. (C) 1997 Academic Press.