POST-SOURCE DECAY FRAGMENT SPECTRA OF CYCLOMALTO-OCTAOSE AND BRANCHEDCYCLOMALTO-HEXAOSE BY MATRIX-ASSISTED LASER DESORPTION IONIZATION TIME-OF-FLIGHT MASS-SPECTROMETRY/

gamma-Cydodextrin, maltosyl-alpha-cyclodextrin and diglucosyl-alpha-cy clodextrin were analyzed using matrix-assisted laser desorption/ioniza tion time-of-flight (MALDI-TOF) mass spectrometry. All of these compou nds have the same molecular weight (M.W.=1297.15) and consist of only D-glucopyranose. From a comparison of the intensities in the post-sour ce decay (PSD) fragment spectra of these cyclodextrin derivatives, cor relation between the chemical structures and the relative intensities in the PSD fragment ions was found. The correlation is considered to b e caused by the difference in the number of cleavage sites at the glyc osyl binding. It was found that the intensity of the PSD ion resulting from one cleavage is higher than that resulting from two cleavages at a glycosyl bond. The results show that PSD fragment-ion spectrum meth od used in MALDI-TOF mass spectrometry is a very powerful technique fo r the structural analyses of the sugar-substituted cyclodextrins.