title: Studies on the glycosphingolipids of the starfish, Asterina pectinifera. II. Isolation and characterization of a novel ganglioside with an internal sialic acid residue.
abstract: 1. Three gangliosides, provisionally named Gangliosides 1, 2, and 3, were obtained from the lipid extract of the starfish, Asterina pectinifera by silicic acid, DEAE-Sephadex, and Iatrobeads column chromatography. The most abundant, Ganglioside 3 (37.7 microgram/g wet weight of starfish) was isolated in the pure state and its chemical structure was studied. 2. The sugar composition of Ganglioside 3 consisted of arabinose, glucose, galactose, and sialic acid (as N-glycolylneuraminic acid) in a molar ratio of 1:1:3:1. Three sialic acid-containing oligosaccharide fragments were isolated from partial acid hydrolysates of the ganglioside by Dowex 1 X 8 (acetate form) column chromatography and preparative paper chromatography, and identified as Gal leads to NeuGc, Gal (1 leads to 4)[Gal(1 leads to 8)]NeuGc and Ara-(1 leads to 6)Gal(1 leads to 4)[Gal(1 leads to 8)]NeuGc. 3. The structure of Ganglioside 3 was postulated to be: Araf,p(1 leads to 6)Galpbeta(1 leads to 4)[Galpbeta(1 leads to 8)]NeuGc(2 leads to 3)Galpbeta(1 leads to 4)Glcpbeta(1 leads to 1)-ceramide. This is a unique structure with the sialic acid residue internally located in the sugar chain. 4. The ganglioside contained saturated 2-hydroxy fatty acids ranging in length from C16 to C24, among which C22, C23, and C24 acids were predominant.  The long-chain bases consisted exclusively of C16, C17, and C18 phytosphingosines of iso and anteiso types.
mesh_terms: D002241:Carbohydrates / Q000032:analysis; D002849:Chromatography, Gas; D002855:Chromatography, Thin Layer; D005732:Gangliosides / Q000032:analysis*; D006028:Glycosphingolipids / Q000032:analysis*; D013058:Mass Spectrometry; D009844:Oligosaccharides / Q000032:analysis; D012794:Sialic Acids / Q000032:analysis; D013215:Starfish / Q000032:analysis*; D001616:beta-Galactosidase
chemical_list: D002241:Carbohydrates; D005732:Gangliosides; D006028:Glycosphingolipids; D009844:Oligosaccharides; D012794:Sialic Acids; D001616:beta-Galactosidase