Holothuria

Echinozoa Holothurioidea Aspidochirotida Holothurioidae Holothuria sp (Aspidochirotacea)... 

Sea cucumbers (Holothuroidea, Echinodermata) appear to be unique in their mode of squalene oxide (37) cyclization. Tritium-labeled lanosterol (33), cycloartenol (32) and parkeol (38) were individually administered to the sea cucumber Holothuria arenicola. While the former two triterpenes were not metabolized [22], parkeol was efficiently transformed into 14x-methyl-5a-cho-lest-9(l l)-en-3/ -ol (39) (Scheme 3). Other A1 sterols present in H. arenicola were not found to be radioactive and were thus assumed to be of dietary origin. The intermediacy of parkeol was confirmed by the feeding of labeled mevalonate (23) and squalene (26) to the sea cucumber Stichopus californicus [15]. Both precursors were transformed into parkeol, but not lanosterol nor cycloartenol, aqd to 4,14a-dimethyl-5a-cholest-9(ll)-en-3/J-ol (40) and 14a-methyl-5a-cholest-9(ll)-en-3/ -ol. Thus, while all other eukaryotes produce either cycloartenol or lanosterol, parkeol is the intermediate between triterpenes and the 14-methyl sterols in sea cucumbers. 

Chromium-zinc mixtures were more-than-additive in toxicity to Tisbe holothuriae, a marine copepod. Zinc in combination with chromium was more toxic to copepods than were mixtures of zinc with copper, lead, nickel, or cadmium (Verriopoulos and Dimas 1988). 

Verriopoulos, G. and S. Dimas. 1988. Combined toxicity of copper, cadmium, zinc, lead, nickel, and chrome to the copepod Tisbe holothuriae. Bull. Environ. Contam. Toxicol. 41 378-384. 

Verriopoulos, G. and M. Moraitou-Apostolopoulou. 1989. Toxicity of zinc to the marine copepod Tisbe holothuriae, the importance of the food factor.Arch. Hydrobiol. 114 457-463. 

Moraitou-Apostolopoulou, M. and G. Verriopoulos. 1982a. Individual and combined toxicity of three heavy metals, Cu, Cd and Cr for the marine copepod Tisbe holothuriae. Hydrobiologia 87 83-87. Moraitou-Apostolopoulou, M. and G. Verriopoulos. 1982b. Toxicity of chromium to the marine planktonic copepod Acartia clausi, Giesbrecht. Hydrobiologia 96 121-127. 

Adverse effects, most sensitive species Brown algae, Fucus serratus Copepod, Tisbe holothuriae Pacific oyster, Crassostrea gigas, larvae Alga, Rhizosolenia spp. 

Fig. (8). Structures of glycosides isolated from the sea cucumbers Holothuria leucospilota and Holothuria forskalii...

The Japanese sea cucumber Cucumaria echinata contained a ganglioside CG-1 (664) with neuritogenic activity toward the rat pheochromocytoma PC-12 cell line [526]. Similar activity was reported for the ganglioside HPG-8 (665) isolated from the sea cucumber Holothuria pervicax from Japan [527]. 

Bandaranayake, W.M. and Des Rocher, A., Role of secondary metabolites and pigments in the epidermal tissues, ripe ovaries, viscera, gut contents and diet of the sea cucumber Holothuria atra, Mar. Biol, 133, 163, 1999. 

Holothuria nobilis102 Echinoderraata Sea cucumber 1600 Respiratory tree Single... 

Holothuria nobilis102 Echinodermata Sea cucumber 1250 Epidermis Single... 

Some triterpene glycosides from holothurians belonging to the family Stichopodidae show also antitumor activities [67, 60]. Holotoxin Al (33) from Apostichopus (=Stichopus) japonicus inhibited the growth of the solid form of Ehrlich tumor and Sarcoma-37 in mice on 37-65 and 13-53 %, respectively, at doses of 1.25 and 2.50 mg/kg. Triterpene glycosides from Holothuria forskali have cytotoxic activities against tumor cells [68]. 

The stichoposides D (28), E (29) and thelenotoside B (31), with no quinovose as second monosaccharide unit, were significantly less effective and inhibited the enzyme activity by 19-27 %. Holothurin Ai (102) from the Holothuria floridana, containing a hydroxyl group on the side chain of aglycon, inhibited activity by... 

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