Cyclic steroidal glycosides

A new type of saponin was discovered as toxic substances in starfishes of the genus Echinaster. The stmcture of steroidal cyclic glycosides, sepositoside A (76) from the Mediterranean starfish Echinaster sepositus [100] was determined. Three major saponins in the same starfish were isolated, and their structures were found to have 22,23-epoxide groups in the side chain [101]. 

Regioselectively addressable functionalized templates (RAFT), oligovalent moieties with chemically distinct functional groups that can be selectively addressed in the preparation of template-associated synthetic proteins (TASP). RAFT are molecular scaffolds that comprise porphyrins, steroids, calixarenes, glycosides, and a variety of cyclic peptides and peptidomimetics. RAFT... 

Phytochemistry A wide assortment of chemical compounds have been isolated from the seeds including triterpene saponins, alkaloids (up to 0.5 %, convolvine and convolamine), cyclic peptides, phenolic acid, flavonoids, and steroids. Roots contain 5 % saponins, sugars, saporubin, and saporubinic acid. Leaves contain the glycoside saponarin (Ogolevitz 1951 Morita et al. 1997a, b Sang et al. 2000, 2003). 

De Simone, F., A. Dini, E. Finamore, L. Minale, C. Pizza, R. Riccio, and F. Zollo Starfish Saponins. Part 5. Structure of Sepositoside A, a Novel Steroidal Cyclic Glycoside from the Starfish Echinaster sepositus. J. Chem. Soc., Perkin Trans. 1 1981, 1855. 

Riccio, R., Dini, A., Minale, L., Pizza, C., Zollo, F., and Sevenet, T. (1982b) Starfish saponins. Vll. Structure of luzonicoside, a further steroidal cyclic glycoside from the Pacific starfish Echinaster luzonicus. Experientia, 38, 68-70. 

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