O-acetylated gangliosides in bovine buttermilk: Characterization of 7-O-acetyl, 9-O-acetyl, and 7,9-DI-O-acetyl G_D3

Three O-acetylated gangliosides, G₁, G₂, and G₃, were purified from bovine buttermilk by using chloroform/methanol extraction, Folch partitioning, chromatography on DEAE-Sephadex A-25, and Iatrobeads columns. The final yields of gangliosides G₁, G₂, and G₃ were 2 mg, 37 mg, and 40 mg per 1.7 kg of the buttermilk powder, respectively. On the basis of immunostaining on high performance thin layer chromatography with specific monoclonal antibodies, mild alkaline treatment, gas-liquid Chromatographie analysis, fast atom bombardment mass spectrometry, and proton nuclear magnetic resonance studies, G₁ and G₂ are characterized as O-acetylated G_D3 and G₃ as O-acetylated G_T3, and the structures of these gangliosides are as follows: equation presented The major fatty acids of these gangliosides were C 18:0, C22:0, C23:0, and C24:0, and the long chain base was C18-sphingosine.