Starfish Asterias rubens

Egg Starfish, Asterias rubens 326 Irreversible inhibition of fertilization membrane formation in eggs transferred 10 sec. after insemination 46... 

Sandworm, Nereis diversicolor, whole British Columbia various locations Polychaete worms, 3 species whole California Echinoderms Starfish, Asterias rubens Gonad... 

Considerable proportions of cerebroside have been detected in the starfish Asterias rubens.9Ail0 It is a glucosylceramide having a-hydroxy fatty acids (from C16 to C26) and dihydroxy bases whose major components are Cl8 and C22 bases, with one, or two, double bonds. 

A second natural product study reported in 2003 that used the sensitivity of cryogenic probe capabilities and the HSQC-TOCSY experiment to advantage was the report by Preiss et al.25S that detailed the elucidation of the structure of two new asterosaponins from the starfish Asterias rubens. The structure of one of the molecules characterized (110) of which only 0.3 mg was isolated, is shown. 

M. Sandvoss, A. Weltring, A. Preiss, K. Levsen, and G. Wnensch, Combination of matrix solid-phase dispersion extraction and direct on-line liqnid chromatography-nnclear magnetic resonance spectroscopy-tandem mass spectrometry as a new efficient approach for the rapid screening of natural prodncts Application to the total asterosaponin fraction of the starfish Asterias rubens, J. Chromatogr A 917 (2001), 75-86. 

Large amounts of C28 and C29 sterols occur in asteroids and other echinoderms but it seems that they cannot be synthesized from C27 sterols by transmethylation as is the case in plants (but not in other animals). This was confirmed with the starfish Laiaster leechii, which could convert MVA into A -cholesterol but could not alkylate this at C-24 or introduce a A -bond. Similarly the starfish Asterias rubens can only synthesize C27 sterols de novo, but here there is evidencethat a A -bond can be introduced into both cholesterol and A -cholesterol. This starfish can also synthesize A -sterols and there is some indication that cholesterol itself may be synthesized even though it was previously concluded that the family could not perform the final steps in this biosynthesis. This species also rapidly metabolized dietary steroids and such A -sterols could be converted into A -products, but it was considered unlikely that the organism had the ability to dealkylate C28 and C29 sterols. 

It should be emphasised that the specificity of attraction of the predator to its prey is not fixed to a certain extent, it would appear that some species can be conditioned to respond to organisms other than their habitual prey, when the latter disappear. This is the case for the tuna Thunnus albacores (Atema et al., 1977), and the starfish Asterias rubens (Castilla, 1972). 

Anthocidaris sp., 151 Arbaciapunctata, 455 Hemicentrotus sp., 151 Lytechinus pictus, 860 Strongylocentrotus purpuratus, 860, 880 Starfish, Asterias rubens, 656... 

Yet, the death of 4-20 million starfish Asterias Rubens on the Letnii Coast of the White Sea s Dvina Gulf in May 1990 is undoubtedly an EC since, as a result, practically the entire population of starfish was lost in the region. 

An examination done with an underwater apparatus showed that almost all starfish had been lost. In the observation area of the apparatus, 1-2 starfish per square meter were detected. The total number of dead and displaced starfish Asterias Rubens was estimated at 4-20 million. 

Ramsay, K., Kaiser, M., and Richardson, C. (2001) Invest in arms behavioural and energetic implications of multiple autotomy in starfish Asterias rubens). Behavioral Ecology and Sociobiology, 50, 360-365. 

Kelm, A., Shaw, L., Schauer, R., and Reuter, G. The biosynthesis of 8-O-methylated sialic acids in the starfish Asterias rubens Isolation and characterisation of -adenosyl-L-methionine sialate-8-O-methyltransferase. Eur. J. Biochem. (1998) 251, 874-884. 

Schlenzka, W., Shaw, L., and Schauer, R., 1993a, Catalytic properties of the CMP-N-acetylneur-aminic acid hydroxylase from the starfish Asterias rubens Comparison with the mammalian enzyme, Biochim. Biophys. Acta 1161 131-138. 

A soluble sialidase in the starfish Asterias rubens has been purified to homogeneity (Schauer and Wember, 1989). This enzyme has a molecular mass of 230 kDa with four identical subunits and preferentially cleaves a2-3-linked sialic acids in various substrates. Another enzyme in the hepatopancreas from the shrimp Penaeus japonicus has been shown to be a 32-kDa protein which binds P-galactosidase in vitro. No protective protein has been detected for this enzyme (Chuang and Yang, 1990) (see Section 5.1 for protective protein). 

Schauer, R., and Wember, M., 1989, Isolation and characterization of a sialidase from the starfish Asterias rubens, Biol. Chem. Hoppe-Seyler 370 183-190. 

Sandvoss, M., Pham, L.H., Levsen, K., Preiss, A., Mtigge, C., and Wiinsch, G. (2000) Isolation and structural elucidation of steroid oligoglycosides from the starfish Asterias rubens by means of direct online LC-NMR-MS hyphenation and one- and two-dimensional NMR investigations. Eur. J. Org. Chem., 1253-1262. 

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