Ircinia variabilis

Four unstable sulfate esters (373-376) of known furanosesterterpenes were obtained from Ircinia variabilis and from /. or os from the northern Adriatic Sea [328], The 22-O-sulfates of palinurin (377) and fasiculatin (378) were isolated from 7. variabilis and from /. fasiculata respectively. Both were toxic to brine shrimp [329]. Ircinianin sulfate (379) was isolated from /. (Psammocinia) wistarii from the Great Barrier Reef as a very unstable metabolite [330]. 

Marin, A., Lopez Belluga, M.D., Scognamiglio, G., and Cimino, G., Morphological and chemical camouflage of the Mediterranean nudibranch Discodoris indecora on the sponges Ircinia variabilis and Ircinia fasciculata, J. Moll. Stud., 63, 431, 1997. 

MELTING point Oil SPECTRAL data UV, IR, PMR organism Ircinia variabilis Schmidt (Porifera) reference 139... 

Constit. of Hippospongia communis, Spongia officinalis and Ircinia variabilis. 

Faulkner, D. J. Variabilin, an Antibiotic from the Sponge, Ircinia variabilis. Tetrahedron Letters 3821 (1973). 

Many species of the sponge genus Spongia contain biosynthetically intriguing C21 difuranoterpenes probably derived from linear sesterter-pene tetronic acids such as variabilin (146) which has long been known as a constitutent of Ircinia variabilis, A detailed discussion of sesterter-... 

Madaio, A., Piccialli, V., Sica, D., and Corriero, G. (1989) New polyhydroxysterols from the Dictyoceratid sponges Hippospongia communis, Spongia officinalis, Ircinia variabilis and Spongionella gracilis.]. Nat. Prod., 52, 952-961. 

Faulkner, D.J. (1973) Variabilin, an antibiotic from the sponge Ircinia variabilis. Tetrahedron Lett., 14, 3821-3822. 

Less common are those examples of this class of compound in which the tetronic acid moiety is nonconjugated. Palinurin (10a) was the first example of this class of compound, isolated from I. variabilis [37]. Subsequently, from an Australian Ircinia sp. was isolated a hydro derivative (11) of palinurin, which inhibits the growth of B. subtilis [38]. 

Four related furanoid sesterterpenes have been isolated from sponges of the genus Ircinia. Ircinin-1 (94) and ircinin-2 (95) from Ircinia oros were found to be isomeric difurano-sesterterpenes containing an unusual conjugated tetronic acid moiety 60). Fasciculatin (96) from Ircinia fasci-culata 37) and variabilin (97) from /. variabilis 84) were shown to be closely related monofurano-sesterterpenes. 

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