Glycosphingolipids of echinoderms -the chemical diversity of carbohydrate and ceramide structure

Glycosphingolipids (GSLs) are glycoconjugates that consist of sphingosine base, fatty acid, and carbohydrate, and found in cell membranes of living world. Gangliosides are sialoglycolipids that present in the central nervous system, and play critical roles in the physiological properties as carbohydrate antigens, cellular recognition, cell-to-cell communication, receptors of cholera toxin B, differentiation inducer, and so on. Many studies of mammalian gangliosides regarding structures, biosynthesis, metabolism, and functions have been accumulated. On the other hand, in the invertebrates, most of the gangliosides could be found from echinoderms, such as sea urchin, starfish, and sea cucumber, and their chemical structures are quite different from mammalian gangliosides. For nearly 30 years, chemical studies on the GSLs of echinoderms have been carried out in our laboratory. In this paper, we will discuss about the chemical diversity of carbohydrate and ceramide in the GSLs of echinoderms.