Isocopalanes

Another dorid nudibranch, Doris verrucosa has been reported (70) to contain an analogue of methylthioadenosine [84] along with diterpenoic acid glycerides, verrucosin A [85] and verrucosin B [86]. The carbon skeleton of the vemicosins could be derived from isocopalane diterpenes which formerly were considered to be the biogenetic precursors of the tetracyclic spongiane diterpenes. 

Isocopalane and its tetracyclic furan derivatives, referred to as spongianes, are found in various sponges such as Spongia officinalis, and in the naked snails eating these sponges. Such compounds include (+)-isocopalene-15,16-dial, the cyclohe-miacetal (-)-spongiane-15,16-diol, the lactone (+)-l ip-hydroxy-12-spongiene-16-... 

FIGURE 10. 70 eV mass spectra of tricyclic diterpanes (C20 and C19) derived from abietic acid or pimaric acid, resins, of coals and high plants. Isolated from coal (a) abietane (b) flchtelite (c) norprimane (d) C2o-tricyclic terpane , (e) isocopalane ... 

New isocopalane diterpene diester from a sub-Antarctic marine nudibranch. Van Wyk, A.W.W., Froneman, P.W., Bernard, K.S., Davies-Coleman, M.T. (2007) ARKIVOC, 2007, 121-128. 

Mycalidae Mycale Cyclic peroxides, macrolides, diterpenes (isocopalane), brominated acetogenines en Cns, acetylenic derivatives, pyrrole derivatives... 

Some examples of diterpenes of isocopalane and ent-isocopalane series were isolated in the species Mycale aff. graveleyi (Mombassa, Kenya) and Coelocarteria cf. sin-gaporensis (Sulawesi, Indonesia). These derivatives are only moderately cytotoxic. 

Fattorusso, E., Romano, A., Taglialatella-Scafati, O., Bavestrello, G., Bonelli, P., and Calcinai, B. (2006b) Coelodiol and coeloic acid, ent-isocopalane diterpenes from ihe Indonesian sponge Coelocarteria cfr. singaporensis. Tetrahedron Lett, 47, 2197-2200. 

Isocopalane, Isocopalene, Isocopalic acid, and Related Compounds... 

Unidentified nudibranch (Marion island, Sub-Antarctic) Van Wyk et al, 2007 (isocopalane skeleton)... 

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