Spongian diterpenes

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. 

Latrunculin B was also present in extracts of C. hamiltoni collected from the reefs off southern Mozambique. The latter specimens of C. hamiltoni also yielded two spongiane diterpene lactones (150,151) [127]. No evidence of the hamiltonins was found in extracts of the Mozambique specimens of C. hamiltoni and possibly reflects geographical variation in the organisms that make up C. hamiltonf s diet in this region of the southern African coast. The structures of both spongiane diterpenes and the hamiltonins A -E were determined from spectroscopic data while the absolute stereochemistry at C-16 in 147 was established by comparison of its CD data with those of related compounds [127]. 

Capelle, N., J.C. Braekman, D. Daloze, and B. Tursch Chemical Studies of Marine Invertebrates. XLIV. Three New Spongian Diterpenes from Spongia officinalis. Bull. Soc. Chim. Belg. 89, 399 (1980). 

For recent reviews of spongiane diterpenes, see Keyzers, Northcote, and Davies-Coleman (2006) and Gonzalez (2007). 

Figure 19.117 Examples of spongian diterpenes (class E) isolated from dictyoceratid sponges.

Keyzers, R.A., Northcote, P.T., and Zubkov, O.A. (2004b) Novel antiinflammatory spongian diterpenes from the New Zealand marine sponge ChelonaplysiUa violacea. Eur. J. Org. Chem., 419-425. 

Rudi, A., Erez, Y, Benayahu, Y, and Kashman, Y. (2005b) Omriolides A and B, two new rearranged spongian diterpenes from the marine sponge Dictyodendrilla aff. rctiara. Tetrahedron Lett., 46,8613-8616. 

New cytotoxic spongian diterpenes from the sponge Dysidea cf. arenaria. Tetrahedron, 65,1495—1499. 

Hirsch, S. and Kashman, Y. (1988) Spongialactone A, a new spongian diterpene from Spongia arabica Spor a offidncdis var. arabica). J. Nat. Prod., 51, 1243-1245. 

Arno, M., Gonzalez, M.A., and Zaragoza, R.J. (1999) Diastereoselective synthesis of spongian diterpenes. Total synthesis of the luranoditerpene (-)-spongia-13(16),14-diene. Tetrahedron, 55,12419-12428. 

Abad, A., Agullo, C., Cunat, A.C., and Garcia, A.B. (2005) Syntheses of oxygenated spongiane diterpenes from carvone, synthesis of dorisenone C. Tetrahedron, 61, 1961-1970. 

Gonzalez, M.A. (2008) Total syntheses and synthetic studies of spongiane diterpenes. Tetrahedron, 64, 445-467. 

McPhail, K.L. and Davies-Coleman, M.T. (1997) New spongiane diterpenes from the East African nudibranch Chromodoris hamdtoni. Tetrahedron, 53, 4655-4660. 

Somerville, M.J., Mollo, E., Cimino, G., Rungprom, W., and Garson, M.J. (2006) Spongian diterpenes from Australian nudibranchs an anatomically guided chemical study. J. Nat. Prod., 69, 1086-1088. 

---