Structure of a New Neuritogenic‐Active Ganglioside from the Sea Cucumber Stichopus japonicus

A new ganglioside molecular species SJG‐2 has been obtained from the n ‐hexane‐soluble lipid fraction of the chloroform/methanol extract of the sea cucumber Stichopus japonicus . On the basis of chemical and spectroscopic evidence, the structure of SJG‐2 has been determined, as NeuAcα2⇄4(NeuAcα2⇄3)Galβ1⇄8NeuAcα2⇄3GalNAcβ1⇄3Galβ1⇄4Glcβ1⇄1Cer. The new ganglioside SJG‐2 , possessing a unique carbohydrate moiety, is the first ganglioside containing either a branched sugar chain moiety or an N ‐acetylgalactosamine residue to be isolated from a sea cucumber. Partial hydrolysis with hot water and dilute acetic acid has proved useful for the structure elucidation of the complex oligosaccharide moieties. Moreover, the ganglioside SJG‐2 exhibits neuritogenic activity toward the rat pheochromocytoma cell line PC12 cells in the presence of NGF. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)