Two ganglioside molecular species [GAA‐6 (1) and GAA‐7 (4)] have been obtained from the water‐soluble lipid fraction of the chloroform/methanol extract of the whole bodies of the starfish Asterias amurensis versicolor Sladen. The structures of these ganglioside molecular species have been determined on the basis of chemical and spectroscopic findings. GAA‐6 (1) is a starfish ganglioside molecular species resembling a mammalian brain ganglioside, GM3. In contrast, GAA‐7 (4) is assigned the same structure as that of the main ganglioside[3] from Asterias amurensis[4] for the oligosaccharide moiety. Partial hydrolysis of oligosaccharide moieties with hot water or dilute acetic acid has proved useful for the structure elucidation of the ganglioside molecular species. Moreover, the Mayn ganglioside molecular species, GAA‐7 (4), shows neuritogenic and growth‐inhibitory activities towards the mouse neuroblastoma cell line (Neuro 2a). The structure‐activity relationship of starfish gangliosides is also discussed.

Six new cerebrosides, asteriacerebroside A (l), B (2), C (3), D (4), E (7) and F (a), have been isolated from the two cerebroside molecular species obtained from the less polar fraction of the chloroform/methanol extract of the starfish Asterias amurensis versicolor Sladen. The structures of these cerebrosides have been determined on the basis of chemical and spectroscopic evidences. Two known cerebrosides, astrocerebroside A (5) and acanthacerebroside C (6), have also been isolated and characterized. Reversed-and normal-phase HPLC were effective in isolating these cerebrosides, showing the very close similarity in their structures. Mass spectrometry of dimethyl disulfide derivatives of the cerebrosides was useful for the determination of the double-bond position in the cerebrosides.As for the study of the glycosphingolipids from the starfishes, in continuation of our preceding study'), isolation and characterization of cerebrosides from Asterias amurensis versicolor Sladen have been conducted in the hope of discovering the biologically active compounds. From the spermatozoa and hepatopancreas of the related starfish, Asterias amurensis3), a molecular species of glu~osylceramide~) having trifold unsaturated long-chain bases and a molecular species of ganglioside 5, have been obtained. In this paper, isolation and structure of six new and two known cerebrosides from the whole bodies of A. amurensis versicolor are reported.The acetone insoluble part, which was obtained from the less polar fraction of the chloroform/methanol extract of the whole bodies of A. amurensis versicolor, was separated by silica gel column chromatography to give two components, AA-1 and AA-2, showing a single spot on normal-phase TLC. In the IR and negative FAB mass spectra of AA-1 and AA-2, strong hydroxy and amide absorptions and a series of molecular ion peaks were observed. AA-1 and AA-2 exhibit the characteristic signals due to sphingosineand phytosphingosine-type cerebroside possessing 2-hydroxy fatty acid and 0-glucopyranose moieties in the I3C-NMR spectra (Table 1). Therefore, AA-1 and AA-2 must be a molecular species of sphingosine-and phytosphingosinetype cerebroside, respectively, composed of 2-hydroxy fatty acid and 0-glucopyranose moieties. Before the separation of the molecular species, AA-1 and AA-2, into individual cerebrosides, the components of the fatty acid and long-chain base moities of these molecular species have been investigated. Fatty Acid and Long-Chain Base Composition of AA-1According to the Gaver-Sweely method6), AA-1 was methanolyzed with methanolic hydrochloric acid to yield a mixture of fatty acid methyl ester (FAM) and a mixture of long chain base (LCB) together with methyl D-glucopyranoside. The FAM mixture exhibited I3C-NMR signals due to normal 2-hydroxy fatty acid methyl esters including monounsaturated compounds at 6 = 14. 2, 52.4, 70.6, 129.7, 129.9 and 175.9. Analysis of the FAM mixture by GC-MS showed the existence of eleven components (FAM-1-11) and they were characterized as methyl 2-hydroxy-pen...

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