A NOVEL MONO-SULFATED PENTAGLYCOSYLCERAMIDE WITH THE ISOGLOBO-SERIES CORE STRUCTURE IN RAT-KIDNEY

A five-sugar sulfated glycosphingolipid containing an isoglobo-series carbohydrate core was isolated from rat kidney and its structure chara cterized by compositional analysis, FTIR spectroscopy, methylation ana lysis and H-1 NMR spectroscopy of the intact glycolipid and its limite d degradation products, and negative liquid secondary ion mass spectro metry (LSIMS). The two dimensional chemical shift correlated spectrosc opy and NOE spectroscopy provided information on the sugar sequence an d linkage as well as anomeric configurations, so as to establish the p resence of a 3-O-sulfated galactose and a Gal alpha 1-3Gal structure w ithin the molecule. Negative LSIMS with collision-induced dissociation defined the sugar sequence and ceramide composition, allowing to conf irm the presence, and indicating the position, of the sulfate group. T he glycosphingolipid was found to be a mono-sulfated derivative of the isoglobo-series core, with the following structure: HSO3--3Gal beta 1 -3GalNAc beta 1-3Gal alpha 1-3Gal beta 1-4Glc beta 1-1Cer (iGb(5)Cer V -3-sulfate).