title: Novel di-O-acetylated GM3s from equine erythrocytes, one containing 4,9-di-O-acetyl-N-glycolylneuraminic acid and another containing 4-O-acetyl-N-glycolylneuraminic acid and 6-O-acetyl-D-galactose.
abstract: A novel GM3 O-acetylated at C-4 and at C-9 of N-glycolylneuraminic acid (4,9-di-O-Ac GM3), together with a second GM3 O-acetylated at O-4 of the neuraminic acid and O-6 of D-galactose (4,6'-di-O-Ac GM3) were isolated from equine erythrocytes as a mixture in approximate 1:1 ratio. These two major species were chromatographically inseparable. Their structures, especially the positions of the acetoxy group(s), were determined by means of 1D- and 2D-1H NMR and fast atom bombardment-MS as well as by gas chromatography-MS of partially O-methylated O-trimethylsilylated monosaccharides derived from the di-O-Ac GM3s. In addition, 4-O-Ac GM3 was chemically mono-O-acetylated with trimethyl orthoacetate under acidic conditions, giving exclusively 4,9-di-O-Ac GM3, the NMR and mass spectra of which were used as references to confirm the 4,9-di-O-acetylated structure of the naturally-occurring GM3.
authors.affiliation: Department of Chemistry, School of Medicine, Sapporo Medical University, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Yachida
authors.forename: K
authors.initials: K
authors.lastname: Tsuchihashi
authors.forename: S
authors.initials: S
authors.lastname: Gasa
mesh_terms: D000107:Acetylation; D000818:Animals; D002240:Carbohydrate Sequence; D004910:Erythrocyte Membrane / Q000737:chemistry*; D005227:Fatty Acids / Q000032:analysis; D005679:G(M3) Ganglioside / Q000737:chemistry*; D005690:Galactose / Q000031:analogs & derivatives* / Q000302:isolation & purification; D006736:Horses; D008969:Molecular Sequence Data; D009438:Neuraminic Acids / Q000302:isolation & purification*; D016339:Spectrometry, Mass, Fast Atom Bombardment; D013110:Sphingosine / Q000031:analogs & derivatives
chemical_list: C106060:4,9-di-O-acetyl-N-glycolylneuraminic acid; C106061:4-O-acetyl-N-glycolylneuraminic acid; C101248:6-O-acetylgalactose; D005227:Fatty Acids; D005679:G(M3) Ganglioside; D009438:Neuraminic Acids; D013110:Sphingosine; D005690:Galactose