[Two new asterosaponins from the antarctic starfish Diplasterias brucei. Structures and cytotoxic activities].

Two new asterosaponins, diplasteriosides A and B, with the same oligosaccharide chains beta-D-Fucp-(1-->2)-beta-D-Galp-(1-->4)-[beta-D-Quip-(1-->2)]-beta-D-Quip-(1-->3)-beta-D-Quip-(1-->, linked to C6 of known genins, 3-O-sulfates of thornasterols A and B, respectively, were isolated along with the previously known asteriidoside A from the Antarctic starfish Diplasterias brucei. The structures of new compounds were elucidated by spectroscopic methods (mainly 2D NMR and mass spectrometry). The cytotoxicity of isolated asterosaponins against human colon cancer cell line HCT-116, human breast cancer cell line T-47D, and human melanoma cancer cell line RPMI-7951 was investigated.

[Three new polyhydroxysteroids from the tropical starfish Asteropsis carinifera].

Thirteen steroidal compounds including three new polyhydroxysteroids, (24R,25S)-24-methyl-5α-cholestane-3ß,6α,8,15ß,16ß,26-hexaol, (22E,24R,25S)-24-methyl-5α-cholest-22-ene-3ß,6α,8,15ß,16ß,26-hexaol and (22E,24R,25S)-24-methyl-5α-cholest-22-ene-3ß,4ß,6α,8,15ß,16ß,26-heptaol, have been isolated along with the previously known ten polyhydroxysteroids from the tropical starfish Asteropsis carinifera collected near the coast of Vietnam. The structures of new compounds were elucidated by spectroscopic methods (mainly 2D NMR and ESI-mass-spectrometry).

[Two new steroid glycosides from the Far East starfish Hippasteria kurilensis].

Two new steroid glycosides were isolated from the Far East starfish Hippasteria kurilensis collected in the Sea of Okhotsk. They were characterized as (22E,24R)-3-O-(2-O-methyl-beta-D-xylopyranosyl)-24-O-[2-O-methyl-beta-D-xylopyranosyl-(1-->5)-alpha-L-arabinofuranosyl]-5alpha-cholest-22-ene-3beta,4beta,6alpha,7alpha,8,15beta,24-heptaol (kurilensosid I) and (24S)-3-O-(2-O-methyl-beta-D-xylopyranosyl)-24-O-(alpha-L-arabinofuranosyl)-5alpha-cholestan-3beta,4beta,6beta,15alpha,24-pentaol (kurilensosid J). In addition, the earlier known glycosides linkosides F and L1, levisculoside G, forbeside L, desulfated echinasteroside A, and granulatoside A were isolated and identified. The structures of the new compounds were established with the help of bidimentional NMR spectroscopy and mass spectrometry.

[Polyhydroxylated steroid compounds from the Far Eastern starfish Distolasterias nipon].

Two new steroid glycosides: distolasteroside D6, (24S)-24-O-(beta-D-xylopyranosyl)-5alpha-cholestane-3beta,6alpha,8,15beta,16beta,24-hexaol, and distolasteroside D7. (22E,24R)-24-O-(beta-D-xylopyranosyl)-5alpha-cholest-22-ene-3beta,6alpha,8,15beta,24-pentaol were isolated along with the previously known distolasterosides D1, D2, and D3, echinasteroside C, and (25S)-5alpha-cholestane-3beta,4beta,6alpha,7alpha,8,15alpha,16beta,26-octaol from the Far Eastern starfish Distolasterias nipon. The structures of new compounds were elucidated by NMR spectroscopy and MALDI TOF mass spectrometry. Like neurotrophins, distolasterosides D1, D2, and D3 were shown to induce neuroblast differentiation in a mouse neuroblastoma C 1300 cell culture.

Neurotrophic effects of polyhydroxylated steroids and steroid glycosides in cultured neuroblastoma cells.

The effects of steroid compounds from Pacific Ocean starfishes were studied using cultured neuroblastoma C-1300 cells. Vital observations and examination of silver-impregnated preparations showed that the test substances in a concentration of 2-10 microM stimulate differentiation and improves survival of neuroblastoma cells under adverse conditions (similarly to neurotrophins). These substances in high concentrations (20-40 microM) had no effect or exhibited cytotoxic activity. The screening test allowed us to select several compounds for further studies of neurotrophic and neuroprotective properties.

New steroid glycosides from the starfish Asterias rathbuni.

Two novel steroidal 24-O-xylosides, designated as rathbuniosides R(1) (1) and R(2) (2), and the known amurensoside A (3) and 3-O-sulfomarthasterone (4) have been isolated from the starfish Asterias rathbuni. The structures of all the compounds were determined from their spectroscopic data, including one- and two-dimensional NMR methods. The compounds 1 and 4 inhibit the cell division of fertilized sea urchin eggs at doses of 7.0 x 10(-5) and 2.9 x 10(-5) M, respectively.

The distribution of free sterols, polyhydroxysteroids and steroid glycosides in various body components of the starfish Patiria (=Asterina) pectinifera.

The distribution of free sterols, polyhydroxysteroids and steroid glycosides in different body components of the Far-eastern starfish Patiria (=Asterina) pectinifera has been studied. It was shown that free sterol fractions from aboral and oral body walls, gonads, stomach and pyloric ceca contained Delta(7) sterols with a preponderance of 5alpha-cholest-7-en-3beta-ol. All these body components had also toxic steroid oligoglycosides. However, polyhydroxysteroids and related low molecular weight steroid glycosides were found in stomach and pyloric ceca only. In pyloric ceca, the sulfated monoside 'asterosaponin' P(1) was identified as a main polar steroid, whereas 6-sodium sulfate of cholestane-3beta,4beta,6alpha,7alpha,8,15beta,16beta,26-octaol predominated in the stomach. Probable biological functions of polar steroids and free sterols in this starfish were discussed. It was suggested that some polyhydroxysteroids and related monoglycosides play the same biological role as bile alcohols and bile acids do in vertebrates.

Hemolytic polar steroidal constituents of the starfish Aphelasterias japonica.

A reinvestigation of the polar steroid fraction from the starfish Aphelasterias japonica, collected near the Russian shore of the Sea of Japan, has afforded two new compounds, the disulfated quinovoside aphelasteroside C (1) and the monosulfated polyhydroxysteroid aphelaketotriol (2). Compounds 1 and 2 contain a unique 23-oxo-24-hydroxylated side chain that is unprecedented in marine steroids. The known compounds cheliferoside L1 (3), 3-O-sulfoasterone (4), forbeside E3 (5), and 3-O-sulfothornasterol A (6) were also isolated from this source. Compounds 1-3, 5, and 6 showed hemolytic activity to mouse erythrocytes.

New steroid glycosides from the deep-water starfish Mediaster murrayi.

Four new 24-O-biosides of 5alpha-cholestane-3beta,6alpha,8,15beta, 24-pentaol, designated as mediasterosides M1 (1), M2 (2), M3 (3), and M4 (4), and the previously known 5alpha-cholestane-3beta,6beta,8, 15alpha,16beta,26-hexaol (5) have been isolated from the deep-water starfish Mediaster murrayi. Glycosides 1-3 contain rare carbohydrate moieties with (1-->5) bonds between the monosaccharide units. Compounds 1 and 2 showed the inhibition of cell division of fertilized sea urchin eggs and exhibited moderate hemolytic activities.

Stimulatory effects of starfish sapogenins (Asterias amurensis and Lethasterias nanimensis chelifera) on molluscan heart (Spisula sachalinensis).

Sapogenins from the starfish Asterias amurensis and Lethasterias nanimensis chelifera, 5 alpha-pregn-9(11)-ene-3 beta,6 alpha-diol-20-one, 5 alpha-cholest-9(11)-ene-3 beta,6 alpha-diol-23-one, 5 alpha-cholesta-9(11),24(25)-diene-3 beta,6 alpha-diol-23-one, (20E)-5 alpha-cholesta-9(11),20(22)-diene-3 beta,6 alpha-diol-23-one and 24 zeta-methyl-5 alpha-cholesta-9(11),20(22)-diene-3 beta,6 alpha-diol-23-one, stimulated the contractile force of the heart of the mollusk Spisula sachalinensis at concentration of 5 x 10(-5) M. Ouabain, a specific inhibitor of Na+,K(+)-ATPase, at concentration of 5 x 10(-5) M had no effect on this physiological model. Starfish sapogenins of the cholestane series moderately inhibited rat brain cortex Na+,K(+)-ATPase and decreased Ca2+ influx into Ehrlich carcinoma cells. In contrast, pregnane asterogenin asterone did not inhibit Na+,K(+)-ATPase and increased the influx of Ca2+ into cells. These effects were not the result of cell membrane damage, because none of the compounds tested have hemolytic activity.