Saponins from Sea Cucumbers

Acid hydrolysis of the glycosides from the Far Eastern holothurian Duasmodactyla kurilensis has yielded a new aglycone the structure of which is 3p-hydroxy-4,4,14-trimethylpregna-9(ll),16-dien-20-one 

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New saponin 104 and known bivittoside D (52) isolated from sea cucumber or a mixture of different sea cucumbers (not correctly identified) exhibited inhibitory activity (Ki) of 30 and 5 pM, respectively, in a chemokine receptor subtype 5 (CCR 5) assay... 

Kalinin, V.L, Avilov, SA., and Stonik, VA (2000) Triterpene glycosides from sea cucumbers (Holofhurioidea) structure, function and evolution, in Saponins in Food, Feed uffs and Medicinal Plants (eds W. Oleszek and A Marston), Wuwer Academic Publishers, Dordrecht, The Netherlands, pp. 155-162. 

Many of the toxins obtained from coelenterates and echinoderms, because of their hemolytic or cytotoxic actions, are assumed to have a general disruptive action on cell membranes. However, since many of these toxins are capable of forming pores or channels in the plasma membrane of cells, their cytolytic actions may be a result of this highly selective action. On the other hand, the saponins from starfish and sea cucumbers have a direct lytic action as a result of their detergent action on the integrity of cells. 

Two trisulfated tetraoside glycosides isolated from the Antarctic sea cucumber Staurocucumis liouvillei, liouvillosides A (88) and B (89) showed little or no cytotoxicity at concentration ranging from 6.25 to 50 ig/ml against Vero cells within 8 h of cell exposure to the compounds but both saponins were cytotoxic following prolonged incubation periods [73]. 

Holothurin B3 (59b), Fig. (27), a new sulfated diglycoside, was isolated from the sea cucumber Holothuria polii [95]. This saponin contains the... 

Recently, frondoside A2-8 (65), a new saponin with a non-holostane aglycone containing a A double bond, a hydroxyl group at C-20 and an acetoxy group at C-22 was isolated from the sea cucumber Cucumaria frondosa. Fig. (33) [62]. 

C. frondosa also contained frondosides C (66b) [58] and A2-I (66c) [62], two holothurins related to frondoside A2-8 (65), Fig. (34) that differed from this holothurin in the presence of a double bond and in the oligosaccharide chain. Previously, two saponins, Ds-penaustrosides A (66c) and B (66d), Fig. (34) lacking the aeetoxy group at C-22 were isolated from the sea cucumber Pewtocta australis [103]. 

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. 

The complete structure (27) of holothurin B, a saponin from the sea cucumber Holothuria leucospilota, has been established. A new sapogenin from another sea cucumber, Bohadschia vitiensis, has been assigned structure (28). Several papers dealing with the synthesis of sechellogenin (29) have appeared. Functionalization of C-18 was achieved by nitrite photolysis. 

I toxins. Among the echinodermata, the stalked grasping organ (pedicellaria) of isolated species of sea urchins and st sh may also serve as a poison weapon. The sea urchin Toxopneustes pileolus is much feared in East Asian waters. Other species of sea urchins also possess poisonous spines (e.g., Diadema setosum). The chemical composition of the venoms is mostly unknown. The cuvierian organs extruded from the cloaca of sea cucumbers when disturbed from sticky fibers in water may also secrete a venom, e.g., the holothurins see also echinoderm saponins. 

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). 

Kelecom, a., B. Tursch, and M. Vanhaelen Chemical Studies of Marine Invertebrates XIX. Glycosidic Chain Structure of Thelothurins A and B, Two New Saponins from the Indo-Pacific Sea Cucumber Thelenota ananas Jaeger (Echinodermata). Bull. Soc. Chim. Belg. 85, 277 (1976). 

Kelecom, A., Daloze, D., and Tursch, B. (1976a) Chemical studies of marine invertebrates. XXI. Six triterpene genin artifacts from thelothurins A and B, toxic saponins of the sea cucumber Thelenota ananas Jaeger (echinodermata) biosynthesis of the thelothurins. Tetrahedron, 32, 2353-2359. 

Kitagawa, I., Sugawara, T., and Yosioka, I. (1976) Saponin and sapogenol. XV. Antifungal glycosides from the sea cucumber Holothuria leucospilota Brandt structure of holofhurin A. Chem. Pham. Butt., 29,1951-1956. 

Van Dick, S., Gerbaux, P., and Flammang, P. (2010) Qualitative and quantitative saponins contents in five sea cucumbers from the Indian Ocean. Mar. Drugs, 8,173-189. 

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