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Two new eunicellin-type diterpenoids, litophynols A [1] and B [2], and the known diterpenoids litophynins E [3], H [11], and I monoacetate [12], were isolated from the mucus secreted by the soft coral Litophyton sp. Their structures have been elucidated on the basis of spectral and single crystal X-ray analyses. These compounds have hemolytic activity.

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Four new cerebrosides, PA-0-1, PA-0-5, PA-2-5 and PA-2-6, rebroside CE-2cr1l obtained from the related sea cucumber were isolated from the two cerebroside mixtures, PA-0 and Cucumaria echinata of the same family. Reversed-phase PA-2, obtained from the less polar fraction of the methanol HPLC was effective in isolating these cerebrosides, showing extract of the sea cucumber Pentacta australis. The structures the very close similarity of their structures. An analysis of of these cerebrosides were determined on the basis of chemi-the mass spectrum of the dimethyl disulfide derivatives of cal and spectroscopic evidence. Another cerebroside, PA-1-cerebrosides was also useful for the determination of the 4, isolated in a pure state from a different cerebroside mix-double-bond position in the sea cucumber cerebroside.ture PA-1, was found to be identical with the known glucoceAs described in the preceding paper"], three sphingosinetype glucocerebrosides, CE-2b, CE-2c and CE-2d, were isolated from a cerebroside mixture, which was obtained from the less polar fraction of the methanol extract of the sea cucumber Cucumaria echinata, and characterized.In continuation of the preceding studies on the sea cucumber C. echinata, the isolation and structure determination of the homogeneous cerebrosides from the related sea cucumber Pentacta australis (Gokakukinko in Japansese) of the same family are conducted due to the considerable interest and importance attached to the determination of the composition of the mixture of glycosphingolipids, and in the hope of discovering the biologically active compounds from marine natural products.In ref.L2] we have reported o n the isolation and structure determination of the biologically active triterpenoid oligoglycosides isolated from the whole bodies of l? australis. In this paper, the isolation and structure determination of four new and one known cerebrosides from the whole bodies of l? australis are described.The chloroform soluble part, which is obtained from the methanol extract of the whole bodies of P australis, is separated by silica gel column chromatography to give three compounds, PA-0, PA-1 and PA-2, showing a single spot on normal-phase (silica gel) TLC.are observed (Scheme 1 and Table 1). Therefore, PA-0 must be a mixture of sphingosine-type cerebrosides composed of fatty acid and P-glucopyranose moieties. Furthermore, PA-0 is presumed to have type of fatty acids and ante-isd3I type of long-chain bases, mainly, because the carbon signals for the terminal methyl groups are observed at 6 = 14.3 (normal form), 6 = 11.5 and 19.4 (ante-iso form) in the 13C-NMR spectrum of PA-0 (Scheme 1 and Table 1). Before separation of the mixture PA-0 into individual cerebrosides, the fatty acid constituents and the stereochemistry of the long-chain base of the cerebroside mixture are investigated. the IR spectrum and a series of molecular ion peaks in the C According to the Gaver-Sweeley methodl41, PA-0 is methanolyzed with methanolic hydrochloric acid to yield a mix-

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