Studies on the Glycosphingolipids of the Starfish, Asterina pectinifera

III. Isolation and Structural Studies of Two Novel Gangliosides Containing Internal Sialic Acid Residues

Abstract

Two gangliosides, provisionally named Gangliosides 1 and 2 in previous studies, were isolated from starfish, Asterina pectinifera by silicic acid, DEAE-Sephadex, and Iatrobeads column chromatography procedures, and preparative thin-layer chromatography, and their structures were established. On the basis of the results of partial acid hydrolysis, methylation and oxidation with chromium trioxide, Gangliosides 1 and 2 were proposed to be Arapβ(1 →6)-Galpβ(1→4)8-0-MeNeuGc(2→, 3)Galpβ(1→4)G1cpβ(1→1)-ceramide and Arapβ(1→ 6)- Galpβ(1 4)NeuGc(2 →)3)Galpβ(1 →4)Glcpβ(1 →1)-ceramide, respectively.
The ceramide moieties of both gangliosides had similar phytosphingosine and 2-hydroxy fatty acid compositions, and both gangliosides were structurally related to the previously described Ganglioside 3.