Glycosphingolipids in insects

Abstract

A group of Calliphora vicina pupal glycolipids could be segregated from the neutral glycosphingolipids, according to their two‐dimensional TLC migration properties and positive reactions toward ninhydrin and fluorescamine spray reagents. These classified zwitterionic glycolipids were isolated by silica‐gel column chromatography and characterized by the presence of a N ‐acetyl‐glucosamine‐bound phosphoethanolamine residue. The structural elucidation of the oligosaccharide moieties was performed by the determination of constituent carbohydrates as alditol acetates, linkage analysis by permethylation, exoglycosidase cleavage, fast‐atombombardment mass spectrometry and NMR spectroscopy. The dominant fatty acid and sphingoid base species of the ceramide moieties were C 20:0 (arachidic acid) and C 14:1 (tetradecasphing‐4‐enine), respectively. The chemical structures of the zwitterionic, biogenetic glycosphingolipid series were determined as: ( P Etn‐6′)GlcNAc(β1–3)Man(β1–4)GlcβCer; GalNAc(β1–4) ( P Etn‐6′)GlcNAc(β1–3)Man(β1–4)Glcβ Cer; GalNAc(α1–4)GalNAc(β1–4) ( P Etn‐6′)GlcNAc (β1–3)Man(β1–4)GlcβCer; Gal(β1–3)GalNAc(β1–4) ( P Etn‐6′)GlcNAc(β1–3)Man(β1–4)Glcβ Cer; Gal(β1–3)GalNAc(α1–4)GalNAc(β1–4) ( P Etn‐6′)GlcNAc(β1–3)Man(β1–4)Glcβ Cer; GlcNAc(β1–3)Gal(β1–3)GalNAc(α1–4)GalNAc(β1–4) ( P Etn‐6′)GlcNAc(β1–3)Man(β1–4)Glcβ Cer.