Sphaerodiscus placenta

The remaining group of sea star compounds are the polyhydroxysteroids (Table 7.10). The aforementioned Echinasteridae family178 elaborates the polyhydroxysteroids shown in Structures 7.145-7.157, one of which (Structure 7.154)191 was previously reported from a Mediterranean sea star Sphaerodiscus placenta. The Antarctic Acodontaster conspicuus produces polyols (Structures 7.157—7.162) 57 hexol (Structure 7.159) can be found in the Mediterranean Coscinaste-rias tenuispina.192 Polyhydroxysteroid (Structure 7.152) has modest cytotoxicity and the polyols shown in Structures 7.158, 7.161, and 7.162 were inhibitory toward sympatric microorganisms none of the others tested displayed notable bioactivity. 

Zollo, F., Finamore, E., and Minale, L., Starfish saponins, XXXI. Novel polyhydroxysteroids and steroidal glycosides from the starfish Sphaerodiscus placenta, J. Nat. Prod., 50, 794, 1987. 

H H 3-OH H 3-OH H a-OH 3-OH SC-31 Crossaster papposus Sphaerodiscus placenta Kicha, Kalinovskii, and Stonik, 1989 Zollo, Finamore, and Minale, 1987... 

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