Studies on glycosphingolipids of larvae of the green-bottle fly, Lucilia caesar. I. Isolation and characterization of glycosphingolipids having novel sugar sequences.

The neutral glycosphingolipids from larvae of the green-bottle fly, Lucilia caesar, were analyzed. Thin-layer chromatograms showed that the larvae contained at least seven major glycolipid components. Of them, the four components with shorter sugar chains consisting of one to four sugar units, were purified by Iatrobeads column chromatography. The structures were identified by partial acid hydrolysis, sequential enzymatic hydrolysis, chromium trioxide oxidation and methylation analysis as: Glc beta (1-1)Cer, Man beta (1-4)Glc beta (1-1)Cer, GlcNAc beta (1-3)Man beta (1-4)Glc beta (1-1)Cer and GalNAc beta (1-4)GlcNAc beta (1-3)Man beta (1-4)Glc(1-1)Cer. These glycolipids altogether comprised 38.3% of the total neutral glycolipid fraction. Unlike common vertebrate glycosphingolipids, the larval ones appear to be quite unique in having the sugar structures, -GlcNAc beta (1-3)Man- and -GalNAc beta (1-4)GlcNAc beta (1-3)Man-, which are novel finding in the natural systems examined so far. The ceramide moieties were composed of normal fatty acids (16:0-22:0) with a small amount of branched acids (16 and 18), and tetradeca- and hexadeca-4-sphingenines as the long-chain bases.