STRUCTURAL ELUCIDATION AND MONOKINE-INDUCING ACTIVITY OF 2 BIOLOGICALLY-ACTIVE ZWITTERIONIC GLYCOSPHINGOLIPIDS DERIVED FROM THE PORCINE PARASITIC NEMATODE ASCARIS-SUUM

The isolated neutral glycosphingolipid fraction from the pig parasitic nematode, Ascaris suum, was fractionated by silica gel chromatography to yield a neutral and a zwitterionic glycosphingolipid fraction, the latter of which mainly contained two zwitterionic glycosphingolipids termed components A and C, Preliminary chemical characterization with hydrofluoric acid treatment and immunochemical characterization with a phosphocholine-specific monoclonal antibody indicated that both compo nents contained phosphodiester substitutions: phosphocholine for compo nent A, and phosphocholine and phosphoethanolamine for component C, Bo th components were biologically active in inducing human peripheral bl ood mononuclear cells to release the inflammatory monokines tumor necr osis factor alpha, interleukin 1, and interleukin 6, Component A was t he more bioactive molecule, and its biological activity was abolished on removal of the phosphocholine substituent by hydrofluoric acid, The glycosphingolipid components were structurally analyzed by matrix-ass isted laser desorption/ionization time-of-flight mass spectrometry, li quid secondary ion mass spectrometry, methylation analysis, H-1 NMR sp ectroscopy, exoglycosidase cleavage, and ceramide analysis, Their chem ical structures were elucidated to be (see Structure I below), [GRAPHI CS] The carbohydrate moiety oligosaccharide core was characterized as belonging to the arthro series of protostomial glycosphingolipids. The ceramide moiety was distinguished;by (R)-2-hydroxytetracosanoic acid as the dominant fatty acid species and by the C17 iso-branched sphingo sine and sphinganine bases, 15-methylhexadecasphing-4-enine and 15-met hylhexadecasphinganine, respectively.