TLC-LSIMS OF NEOGLYCOLIPIDS OF GLYCOSAMINOGLYCAN DISACCHARIDES AND OFOXYMERCURATION CLEAVAGE PRODUCTS OF HEPARIN FRAGMENTS THAT CONTAIN UNSATURATED URONIC-ACID

Heparin and chondroitin sulfate disaccharides have been investigated b y high-performance (HP) TLC and liquid secondary-ion mass spectrometry (LSIMS) after conversion to neoglycolipid derivatives by reductive-am ination with an aminolipid (dihexadecyl phosphatidylethanol amine, DHP E). Mobility on HPTLC was largely determined by the number of sulfate groups present, but was also influenced by the position of sulfate, mo nosaccharide composition and linkage. The mass spectra acquired direct ly from the TLC plate provided quasimolecular and fragment ions from w hich composition, including sulfate content, and sequence information was obtained at high sensitivity. Lipid DHPE conjugation and TLC-LSIMS were performed to analyse products of the oxymercuration reaction use d to cleave unsaturated uronic acid (Delta UA) residues from glycosami noglycan (GAG) fragments produced by enzymatic degradation with glycan lyases. Previously the identification of the product from Delta UA an d the integrity of the remaining structures