STRUCTURAL CHARACTERIZATION OF NOVEL INOSITOL PHOSPHOSPHINGOLIPIDS OFTRITRICHOMONAS-FETUS AND TRICHOMONAS-VAGINALIS

Two major ethanolamine phosphate-substituted inositol phosphosphingoli pids have been identified in the unsaponifiable acidic lipid fractions of Tritrichomonas foetus and Trichomonas vaginalis. The compounds wer e radiolabelled and purified by high-performance thin-layer chromatogr aphy followed by high-performance liquid chromatography. The structure s were determined by a combination of tandem mass spectrometry (MS/MS) and nuclear magnetic resonance (NMR) experiments, and gas-liquid chro matography of components obtained by degradation and derivatization. I nositol in the T. foetus component was 1-linked to the phosphosphingol ipid, had the phosphoethanolamine group at the 3-position and a fucosy l residue at the 4-position. The T. vaginalis component lacked the fuc osyl moiety. Both organisms also produced inositol phosphosphingolipid s having the same long-chain base (sphingosine or dihydrosphingosine) and the same fatty acyl distribution as the inositol diphosphate compo unds. These glycosphingolipids may represent metabolic intermediates f or new types of membrane anchors for surface glycopeptides or glycolip ids that mediate the host-parasite relationship of these trichomonads. The MS/MS and NMR spectroscopic data should provide reference informa tion for structural determinations of other phosphorylated inositol de rivatives.