Studies on Glycosphingolipids of Fresh-Water Bivalves. VI. Isolation and Chemical Characterization of Neutral Glycosphingolipids from Spermatozoa of the Fresh-Water Bivalve, Hyriopsis schlegelii1

Abstract

The spermatozoa of the fresh-water bivalve, Hyriopsis schiegelil, had a complex spectrum of neutral glycosphingolipids. CDS, CTS, and CreS were isolated as minor components (together they accounted for 3% of the total neutral glycolipid fraction), while CMS and the glycolipids (Lipid I, II, and III) with larger saccharide chains that were previously characterized (1–4) occurred as major ones. The chemical structures were determined by employing exoglycosidases, partial acid hydrolysis and permethylation analysis. The proposed structures are as follows: Mana(1–3)Manβ(1—4)Glc-Cer for CTS, and Manα(1–3)[Xylβ(1–2)]Manβ(1–4)Glc-Cer for CTeS. CTeS was the first example of a tetraglycosyl ceramide containing xylose. In another fraction, two types of diglycosyl ceramides were obtained as a mixture, and identified as Manβ(1–4)Glc-Cer and Galβ(1–4)Glc-Cer, respectively. The long-chain base was predominantly composed of sphingosine, and the acyl groups were mainly of palm itate and stearate.