Nakafuran-9 from

Sponges produce furanosesquiterpenes of various skeletal types, such as furodysinin (118) from Dysidea herbacea and nakafuran-8 (119) from D. etheria, the latter of which is antifeeding. Similarly, mixed shikrmate-mevalonate metabolites are often encountered as sponge metabolites the first example is avarol (120), which was isolated from Dysidea avara. Several related compounds have been isolated from dictyoceratid... 

Cardellina, J.H. II and Bamekow, D.E. (1988) Oxidized nakafuran 8, sesquiterpenes from the sponge Dysidea etheria. Structure, stereochemistry and biological activity. J. Org. Chem., 53, 882-884. 

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