Compounds from Starfish

Komori et al. (555) reported the isolation of a cerebroside mixture (987) and two nucleosides, thymine desoxyribonucleoside (988) and uracil desoxyribonucleoside (989), from Acanthaster planci. Structure elucidation was based on and C-NMR spectrometry as well as on El- and FD mass spectrometry. Similar cerebroside mixtures which showed nearly identical IR-spectra could be extracted from Luidia qui naria and Astropecten latespinosus. The mycosporine-like amino acids (990-994) have been obtained from alcoholic extracts of the starfish Asterina pectinifera 656). 

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Anderson, L. Bohlin, L. lorizzi, M. Riccio, R. Minale, L. Moreno-Lopez, W. Biologically Active Saponins and Saponin-Like Compounds from Starfish and Brittle-Stars. Toxicon. 1989, 27, 179-188. 

Callyspongins A-B (617-618) are sulfated compounds from a Japanese sample of Callyspongia truncata. They inhibit fertilisation of starfish (Asterias amurensis) gametes [493]. 

Much work has been done in the last thirty years on the isolation and structural characterization of saponins and polyhydroxylated steroid glycosides from starfishes and sea cucumbers. The wide spectrum of biological activities these compounds show must be related to their role in the organisms that produce them and this task must be addressed in future investigations. 

Several steroidal saponin sulfates have been reported from starfish (Hostettmann, 1985). Sea cucumbers secrete water-soluble glycosides, holothurins, that possess greater hemolytic ability than saponins of plant origin. These compounds are mixtures of glycoside sulfates (Agarwal and Ras-togi, 1974). 

As the glycosides from starfish are steroidal in nature and as some known polyhydroxylated steroids with moderate cytotoxicity have been isolated from these animals, the literature since 1980 dealing with such compounds will be reviewed here. Aside from some monohydroxyste-rols from Echinaster sepositus 646), Acanthaster planci 647) - this being a source of a new cyclopropane sterol Asterias vulgaris 648), and Comasterias lurida 649), the reports deal mainly with polyhydroxylated steroids. 

Ivanchina, N.V., Malyarenko, T.V., Kicha, A.A., Kalinovsky, A.I., and Dmitrenok, P.S. (2008) Polar steroidal compounds from the Far Eastern starfish Lethasterias Jusca. Russ. Chem. Bull., 56, 204-208. 

Levina, E.V., Kalinovsky, A.I., Stonik, V.A., Dmitrenok, P.S., and Andriyaschenko, P.V. (2005b) Steroid compounds from Par Eastern starfishes Henricia aspera and H. tumida. Russ. J. Bioorg. Chem., 31, 467-474. 

Korotchenko and coworkers detected PG-like compounds in five starfish from the Sea of Japan Asterias amurensis, Distolasterias nippon, Evasterias r. tabulata, Lysastrosoma anthosticta, and Patina pectinifera [189]. Perry and Epel showed that Pisaster ochraceous homogenates were able to oxidize AA [190]. Early studies on oocyte maturation in starfish suggested that HETE s might play a role [195]. Two compounds, 12- and 15-HETE, were able to induce oocyte maturation. Subsequent work showed that the activity was actually due to 8-HETE (33), which was a minor contaminant of both HETE preparations [196]. The 8R enantiomer of this compound (33) and 8R-HEPE (32) were also isolated from the aqueous extracts of Patiria miniata from the Gulf of California [197],... 

The absolute stereochemistries for both compounds were determined by CD analysis of the p-bromobenzoate derivatives. Two other eicosanoids were also isolated from whole animals [198], The trihydroxylated oxylipin 8jR,11S,12R-trihydroxyeicosa-5Z,9 ,14Z,17Z-tetraenoic acid (trioxilin A4,150) was detected in, or isolated from, five starfish species P. miniata, Dermasterias imbricata, Pycnopodia helianthoides, Culcita novaeguinea, and Nardoa tubercolata. Its structure was determined by H and 13C NMR and FAB-MS analyses of the natural product and of an acetonide derivative. The co6 analog of this compound (151) was isolated only from P. helianthoides. The relative stereochemistry in these metabolites (150, 151) was established from a comparison of NMR shifts with malyngic acid, a trihydroxylated C18 compound isolated from Lyngbya majuscula, while the absolute stereochemistry was proposed on the basis of the earlier isolation of 8R-HETE from P. miniata. 

As far as we know, one species, or a few closely related ones, often have a monopoly on a particular compound. The tobacco plant (Nicotiana tabacum), for example, synthesizes nicotine to defend itself from attack by herbivores (animals that feed on plants) and as a convenient way of storing nitrogen temporarily. Neither roses, elephants, nor starfish contain nicotine. In fact, apart from a few of tobacco s close relatives, we know of no other living organism that makes nicotine. In the same way, other plants have devised their own defensive compounds for protection from herbivores. 

Many starfish cause an escape response in usually sessile marine invertebrates [7]. The starfish Dermasterias imbricata causes the sea anemone Stomphia coccinea to release its basal disc from the substratum and swim away on contact. Bioassay-directed fractionation of the starfish extract led to the isolation of the compound found to elicit this response, the benzyltetrahydroisoquinoline alkaloid imbricatine (646). The structure of compound 646 was elucidated by spectral data interpretation. The amino acid residue in imbricatine is related to the thiol containing amino acids ovothiols A-C. Imbricatine (646) is active in both LI210 and P388... 

The taurine residue can also be found as an amide derivative of the 26-carboxylic acid function in the 3p,5a,6p,15a-polyhydroxylated steroids 328 and 329, which were obtained from the starfish Myxoderma platyacanthum [245]. The structures of both compounds were determined from spectral data and chemical correlations. The bile of the sunfish Mola mola has been shown to contain a new bile acid conjugated with taurine (330) together with sodium taurocholate. Compound 330 was identified as sodium 2-[3a,7a, 11 a-trihydroxy-24-oxo-5P-cholan-24-yl]amino]ethane-sulfonate on the basis of its physicochemical data and chemical transformations [246]. 

Closely related to these compounds are the carolisterols A-C (331-333), which were isolated from deep-water starfish Styracaster caroli [247]. Carolisterols A-C are characterized by a polyhydroxycholanic acid moiety in which the 24-carboxylic acid function is found as an amide derivative of D-cysteinolic acid. Z)-cysteinolic acid has been found in fish, alga, and other marine organisms [248]. 

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