Constituents of Holothuroidea, 18. Isolation and structure of biologically active disialo- and trisialo-gangliosides from the sea cucumber Cucumaria echinata

Three new disialo- and trisialo-gangliosides, CEG-6 (6), CEG-8 (8), and CEG-9 (9), were obtained, together with one known ganglioside, HLG-3 (7), from the lipid fraction of the chloroform/methanol extract of the sea cucumber Cucumaria echinata. The structures of the new gangliosides were determined on the basis of chemical and spectroscopic evidence to be 1-O-[alpha-L-fucopyranosyl-(1-->11)-(N-glycolyl-alpha-D-neuraminosyl)-(2-->4)-(N-acetyl-alpha-D-neuraminosyl)-(2-->6)-beta-D-glucopyranosyl]-ceramide (6) and 1-O-[(N-glycolyl-D-neuraminosyl)-(2-->11)-(N-glycolyl-D-neuraminosyl)-(2-->4)-(N-acetyl-D-neuraminosyl)-(2-->6)-D-glucopyranosyl]-ceramide (8, 9). The ceramide moieties of each compound were composed of an homogeneous sphingosine or phytosphingosine base and heterogeneous 2-hydroxy or nonhydroxylated fatty acid units. These gangliosides showed neuritogenic activity toward the rat pheochromocytoma cell line PC-12 in the presence of nerve growth factor.     

Constituents of holothuroidea. 10. Isolation and structure of a biologically active ganglioside molecular species from the sea cucumber Holothuria leucospilota

Three ganglioside molecular species, HLG-1 (1), HLG-2 (2), and HLG-3 (3) have been obtained from the lipid fraction of the chloroform/methanol extract of the sea cucumber Holothuria leucospilota. The structures of these gangliosides have been determined, on the basis of chemical and spectroscopic evidence, as 1-O-[(N-glycolyl-alpha-D-neuraminosyl)-(2-->6)-beta-D-glucopyranosyl]-ceramide (1), 1-O-[(N-glycolyl-alpha-D-neuraminosyl)-(2-->4)-(N-acetyl-alpha-D-neuraminosyl)-(2-->6)-beta-D-glucopyranosyl]-ceramide (2) and 1-O-[alpha-L-fucopyranosyl-(1-->11)-(N-glycolyl-alpha-D-neuraminosyl)-neuraminosyl)-(2-->4)-(N-aetyl-alpha-D-neuraminosyl)-(2-->6)-beta-D-glucopyranosyl]-ceramide (3). The ceramide moieties were composed of heterogeneous phytosphingosine, sphingosine and 2-hydroxy fatty acid units. Compounds 2 and 3 represent new ganglioside molecular species. These three ganglioside molecular species showed neuritogenic activity toward the rat pheochromocytoma cell line, PC-12 cell, in the presence of NGF (nerve growth factor).     

Constituents of Holothuroidea, 13. Structure of neuritogenic active ganglioside molecular species from the sea cucumber Stichopus chloronotus

Three ganglioside molecular species, SCG-1, SCG-2, and SCG-3, were obtained from the lipid fraction of the chloroform-methanol extract of the sea cucumber Stichopus chloronotus. On the basis of chemical and spectroscopic evidence, the structures of these gangliosides have been determined to be 1-O-[(N-glycolyl-alpha-D-neuraminosyl)-(2-->6)-beta-D-glucopyranosyl]-ceramide (SCG-1), 1-O-[8-O-sulfo(major)-(N-acetyl-alpha-D-neuraminosyl)-(2-->6)-beta-D-glucopyranosyl]-ceramide (SCG-2), and 1-O-[alpha-L-fucopyranosyl-(1-->11)-(N-glycolyl-alpha-D-neuraminosyl)-(2-->6)-beta-D-glucopyranosyl]-ceramide (SCG-3). The ceramide moieties were composed of heterogeneous long-chain base and fatty acid units. SCG-3 is the first type of ganglioside containing a fucopyranose in the sialosyl trisaccharide moiety. Moreover, these three gangliosides exhibited neuritogenic activity toward the rat pheochromocytoma PC12 cells in the presence of nerve growth factor.     

Determination of the absolute configuration of sialic acids in gangliosides from the sea cucumber Cucumaria echinata

Enantiomeric pairs of sialic acid, D- and L-NeuAc (N-acetylneuraminic acid), were converted to D- and L-arabinose, respectively, by chemical degradation. Using this method, the absolute configuration of the sialic acid residues, NeuAc and NeuGc (N-glycolylneuraminic acid), in the gangliosides from the sea cucumber Cucumaria echinata was determined to be the D-form. Although naturally occurring sialic acids have been believed to be the D-form on the basis of biosynthetic evidence, this is the first report of the determination of the absolute configuration of the sialic acid residues in gangliosides using chemical methods.     

Constituents of holothuroidea, 12. Isolation and structure of glucocerebrosides from the sea cucumber Holothuria pervicax

Ten glucocerebrosides, HPC-3-A-HPC-3-J, have been isolated from their obtained parent glucocerebroside molecular species HPC-3, together with other glucocerebroside molecular species HPC-1 and HPC-2, from the less polar lipid fraction of a chloroform/methanol extract of the sea cucumber Holothuria pervicax. The structures of these glucocerebrosides have been determined on the basis of chemical and spectroscopic evidence. Reversed-phase HPLC, including a recycling system, was effective in isolating these glucocerebrosides, revealing a very close resemblance in structure, though the problem due to regio-isomers remains.     

Constituents of Holothuroidea, 15. Isolation of ante-iso type regio-isomer on long chain base moiety of glucocerebroside from the sea cucumber Holothuria leucospilota

An ante-iso type regio-isomer on the long chain base moiety of a glucocerebroside, HLC-2-A, has been isolated from its parent glucocerebroside molecular species HLC-2 composed of iso and ante-iso isomers, from the less polar lipid fraction of a chloroform/methanol extract of the sea cucumber Holothuria leucospilota. Reverse-phase HPLC that included a recycling system was effective in separating the regio-isomer from its counterpart, revealing a very close resemblance in structure. Other typical glucocerebroside molecular species HLC-1 and HLC-3 were obtained together with HLC-2. The structures of these glucocerebrosides were determined on the basis of chemical and spectroscopic evidence.     

Constituents of holothuroidea, 14. Isolation and structure of new glucocerebroside molecular species from the sea cucumber Stichopus japonicus

Five glucocerebroside molecular species, SJC-1-SJC-5, have been isolated from the less polar lipid fraction of a chloroform/methanol extract of the sea cucumber Stichopus japonicus. The structures of these glucocerebroside molecular species were determined on the basis of chemical and spectroscopic evidence. SJC-1, SJC-2, and SJC-3 are typical sphingosine- and phytosphingosine-type glucocerebroside molecular species with nonhydroxylated and hydroxylated fatty acyl moieties. SJC-4 and SJC-5 are also sphingosine-type glucocerebroside molecular species with hydroxylated fatty acyl moieties, although they are new glucocerebroside molecular species with unique sphingosine bases.     

Constituents of holothuroidea.9. Isolation and structure of a new ganglioside molecular species from the sea cucumber Holothuria pervicax

A new ganglioside molecular species, HPG-7 (1) was obtained from the polar fraction of the chloroform/methanol extract of the sea cucumber, Holothuria pervicax. On the basis of chemical and spectroscopic evidence, the structure of 1 was determined, and the major component was 1-O-[alpha-L-fucopyranosyl-(1-->4)-(N-acetyl-alpha-D-neuraminosyl) - (2-->11)-(N-glycolyl-alpha-D-neuraminosyl)-(2-->4)-(N-acetyl -alpha-D- neuraminosyl)-(2-->6)-beta-D-glucopyranosyl]-(2S,3S,4R)-2-[(2R)-2- hydroxytetracosanoylamino]-14-methyl-hexadecane-1,3,4-triol. This is the first report on the isolation and structure elucidation of trisialo-ganglioside from sea cucumber. 1 showed neuritogenic activity toward the rat pheochromocytoma cell line, PC-12 cell.     

Structure of holothurin A a biologically active triterpene-oligoglycoside from the sea cucumber holothuria leucospilota brandt

On the basis of chemical and physicochemical evidence, the structure of holothurin A, a biologically active major obligoglycoside o lanostane-type triterpene holothurigenol ($\text{2}$), has been elucidated to be $\text{8}$.     

Cucumarioside C — A new triterpene glycoside from the sea cucumber of Cucumaria fraudatrix

Chemistry of Natural Compounds -     

Radioprotective properties of Cumaside, a complex of triterpene glycosides from the sea cucumber Cucumaria japonica and cholesterol

The radioprotective activity has been studied of a new immunomodulatory lead material, Cumaside, which is a complex of monosulfated triterpene glycosides from the edible sea cucumber Cucumaria japonica and cholesterol. Female CD-1 strain mice administered with prophylactic doses of Cumaside were irradiated using a Gamma-therapeutic device with a 60Co source (exposure dose 6.5 Gy, dose rate 1.14 Gy/min) and the average life span of the mice was determined. The animals administrated with Cumaside and irradiated were killed by pervisceral dislocation on days 4 and 9. Peripheral blood cell composition indexes, blood forming function and cell number in blood-forming organs and the number of pluripotent blood-forming stem cells were determined using standard procedures and the results compared with those of non-treated irradiated mice. The survivability percentage and average life span of the irradiated mice that were not treated with Cumaside were decreased in comparison with the Cumaside-treated groups. Especially, the leukocyte and neutrophil numbers in the blood (bone marrow from hip), and the weight and cell number of lymphoid organs were higher in the Cumaside-treated groups compared with the non-treated irradiated mice. It was concluded that at low prophylactic doses Cumaside possesses moderate radioprotective properties.     

Isolation and structure determination of the biologically active sphingolipids from marine sponge Haliclona species

In a continuation to our study on the marine sponge Haliclona species we have isolated three new cytotoxic components of sphingolipids (1-3). Methanolysis of the sphingolipid 1a-d in methanol produces fatty acid methyl ester. GC/MS was used to determine the length. The structure of each isolated compound has been determined on the basis of spectroscopic data and chemical evidence.     

Biologically active glycosides from asteroidea, 42. Isolation and structure of a new biologically active ganglioside molecular species from the starfish Asterina pectinifera

A ganglioside molecular species GP-3 (1) has been obtained from the water-soluble lipid fraction of the chloroform/methanol extract of the starfish Asterina pectinifera. The structure of the ganglioside has been determined on the basis of chemical and spectroscopic evidence. Compound 1 represents new ganglioside molecular species possessing two moles of sialic acids at the inner part of the sugar moiety. Partial hydrolysis by hot water and an enzymatic hydrolysis by means of endoglycoceramidase (EGCase) have proved useful for structure elucidation of the complex oligosaccharide moiety. Moreover, 1 exhibits neuritogenic activity toward the rat pheochromocytoma cell line, PC-12 cells, in the presence of nerve growth factor (NGF).     

Fallaxosides B1 and D3, triterpene glycosides with novel skeleton types of aglycones from the sea cucumber Cucumaria fallax

Two unprecedented triterpene glycosides, fallaxosides B₁ and D₃ with aglycones of new skeletal types were isolated from the sea cucumber Cucumaria fallax (Cucumariidae, Dendrochirotida). The first of these aglycones is formed as result of intramolecular aldol condensation of a precursor having 1,6-diketone functionality, while the second one by pinacol-pinacolone-like rearrangement of another precursor, probably containing 7,8,9-trihydroxy fragment (or its 8,9-epoxy-7-hydroxy analog). The structures of these compounds were established by analysis of 1D, 2D NMR, ESI MS and CD data with using the quantum-chemical calculations.     

Immunomodulatory action of monosulfated triterpene glycosides from the sea cucumber Cucumaria okhotensis: stimulation of activity of mouse peritoneal macrophages

Six monosulfated triterpene glycosides, frondoside A1 (1), okhotoside B1 (2), okhotoside A1-1 (3), frondoside A (4), okhotoside A2-1 (5) and cucumarioside A2-5 (6), isolated from Cucumaria okhotensis Levin et Stepanov, stimulate spreading and lysosomal activity of mouse macrophages and ROS-formation in the macrophages. The highest macrophage spreading and stimulation of their lysosomal activity was induced by glycosides 1, 4 and 6. All glycosides similarly stimulate ROS formation in macrophages, but glycoside 2 caused minimal stimulation.     

Isolation and sequencing of a new biologically active peptide from human lung carcinoma

A biologically active peptide designated hLCP has been isolated and purified to homogeneity from human lung carcinoma by means of acidic extraction and successive chromatography on Sephadex G-50, Toyopearl HW-40 F and reverse-phase high performance liquid chromatography columns. Analysis showed that peptide consists of thirteen amino acids. Primary structure of hLCP has been deduced by double-coupling Edman degradation combined with enzyme digestion as H-Ser-Pro-Pro-Asp-Gly-Lys-Lys-Glx-Ser-Ala-Asp-Val-Lys-OH. hLCP possessed significant excitatory activity on an electrical stimulation induced contraction. No hLCP could be detected in normal lung tissue. The possibility of using hLCP as a biochemical marker in the clinic for the early detection of lung carcinoma is being investigated.     

Constituents of Crinoidea, 4. Isolation and structure of ceramides and glucocerebrosides from the feather star Comanthus japonica

Five ceramides, JC-1-JC-5, and four glucocerebrosides, JCer-1-JCer-4, have been isolated from their parent ceramide and glucocerebroside molecular species JC and JCer obtained from the less polar lipid fraction of the chloroform/methanol extract of the feather star Comanthus japonica. The structures of these sphingolipids have been determined on the basis of chemical and spectroscopic evidence. Reversed-phase HPLC was effective at isolating these sphingolipids, revealing very close resemblance in their structures. JC-1, JC-3, JC-4, JC-5 and JCer-2, JCer-4 are newly found ceramides and glucocerebrosides, respectively.     

Synthesis, structure and redox potentials of biologically active ferrocenylalkyl azoles

The syntheses, structures, electrochemical properties of the series of ferrocenylalkyl azoles, FcAlkAz, as well as the antitumor activity of ferrocenylmethyl benzimidazole (8) have been studied. Above mentioned compounds were investigated by the method of cyclic voltametry. All of them exhibited a reversible one-electron oxidation-reduction wave owing to the ferrocene-ferrocenium redox couple with a positive shift (0.50-0.65 V) compared with that of ferrocene (0.42 V). The X-ray determination of molecular structures of 1-(ferrocenylmethyl)imidazole (4), 1-(ferrocenylbenzyl)imidazole (7) and 1-(ferrocenylmethyl)bezimidazole (8) was carried out. Compound 4 with imidazolyl substituent was found to be present in N-protonated form. Antitumor activity of 1-(ferrocenylmethyl)benzimidazole (8) against some solid tumor models such as adenocarcinoma 755 (Ca755), melanoma B16 (B16) and Lewis lung carcinoma was studied. The antitumor activity of compound 8 was compared with cisplatin effectiveness against some experimental tumor systems.