Nor-diterpene

Two nor-diterpene dilactones from Podocarpus nagi. Kubo, I. Ying, B.P. Phytochemistry 1991,30,1967-1969. 

Bavoso A, Cafieri F, De Napoli L, Di Blasio B, Fattomsso E, Pavone V, Santacroce C (1987) Isolation and Structure Determination of Norsphaerol, a Bis-nor-Diterpene from the Red Alga Sphaerococcus coronopifolius. Gazz Chim Ital 117 87... 

Mayol, L., Piccialli, V., and Sica, D., Gracilin A, a unique nor-diterpene metabolite from the marine sponge Spongionella gracilis, Tetrahedron, 26, 1357, 1985. 

The structure of the diterpene 107 (C20H30O3) was established by spectroscopic methods and confirmed by x ray diffraction studies while, under nmr, the nor-diterpenes 109-113 proved to be structures with an exocyclic methylene and no carboxylic groups at C-4 and are assumed to be the result of an oxidative decarboxylation process as has occurred elsewhere. Orthosphenia mexicana yielded another new diterpene of the nor-isopimaradiene type (C19H28O3) related to the above-mentioned products [43] spectroscopic analysis and chemical trans-formations established its structure with a tertiaiy hydroxyl, an a,P-unsaturated keto group and the presence of a typical vinyl system of the ABX type. 

Chatterjee A, Banerjee A, Bohlmann F 1977 Crotocaudin a rearranged labdane type nor-diterpene from Croton daudatus Geisel. Tetrahedron 33 2407-2414... 

Misra R, Pandey R C, Sukh Dev 1978 Higher isoprenoids. X. Diterpenoids from the oleoresin of Hardwickia pinnata. Part 3 Kolavenol, kolavelool and a nor diterpene hydrocarbon. Tetrahedron 35 985-987... 

To these four diterpenic skeletons is added that of nor-sphaerane, which is actually a bis-nor-diterpene because it only contains 18 carbon atoms, and the two recently discovered carbon skeletons of sphaeroane and that of coronone (Smyrniotopoulos, Vagias, and Roussis, 2009 Smymiotopoulos et al., 2010a). 

Bavoso, F A., Cafieri, F., De Napoli, L., Di Balso, B., Fattorusso, E., Pavone, V, and Santacroce, C. (1987) Isolation and structure determination of norsphaerol, a bis-nor-diterpene from the red alga Sphaerococcus coronopijblius. Gazz. Chim. Ital., 117,87-89. 

Several species of Sargassum, and Cystophora, contain derivatives of farnesylacetone (bis-nor-diterpenes) that have insecticidal properties, which might prevent the setting of larvae on the thallus (Kubo, Matsumoto, and Ichikawa, 1985). 

All Other cyclic peroxides isolated from species of the family Latrunculiidae have terpenic skeletons, linear or cyclic, with or without transposition, and very often with loss of a carbon atom (nor-diterpenes and nor-sesterter-penes). Most of these peroxy derivatives are cytotoxic, antiviral and antiparasitic against toxoplasmosis and malaria (Albericci et al, 1982 Capon, MacLeod, and Willis, 1987 Hai-Yin and Faulkner, 1991 Butler and Capon, 1992a D Ambrosio et al, 1998 Ovenden and Capon, 1998 El Sayed et al, 2001a Youssef et al, 2001 Youssef, 2004 Dembitsky, Gloriozova, and Poroikov, 2007 Dembitsky, 2008). Some examples of peroxides are presented below. 

Sigmosceptrins A-C are nor-diterpenes derived directly from the skeleton of labdane, or which are formed from a backbone transposition. They were isolated from an Australian species of the genus Sigmosceptrdla (Bassett et al., 1997). 

Other nor-diterpenes and nor-sesterterpenes with the carbon skeleton of laurendane, labdane or aplysane (see Figure 13.15) were isolated from the Australian species Latrunculia brevis and L. conulosa (Butler and Capon, 1991, 1992a). 

Bassett, S., Ovenden, S.P.B., Gable, R.W., and Capon, R.J. (1997) Sigmosceptrins A-C new nor-diterpenes from a Southern Australian marine sponge S mosceptrdla sp. Aust.J. Chem., 50,1137-1143. 

D Ambrosio, M., Guerriero, A., Deharo, E., Debitus, C., Munoz, V., and Pietra, F. (1998) New types of potentially antimalarial agents, epidioxy-disubstituted nor-diterpenes and nor-sesterterpenes from the marine sponge Diacartms Imi. Helv. Chim. Acta, 81,1285-1292. 

Xestenone, a nor-diterpene with an unusual bicyclic skeleton was isolated from the Northeastern Pacific sponge Xestospongia vanilla (Northcote and Andersen, 1988). Its absolute configuration was determined by total synthesis (Ota et al., 2009). 

Mayol, L Picciali, V and Sica, D, (1986) Metabolites from sponge Spongionella gracilis. Three further nor-diterpenes one of them based on a novel carbocyclic skeleton. Tetrahedron. 42, 5369-5376,... 

Bowden, B.F., Coll, J.C., Mitchell, S.J., Mulder, J., and Stokie, G.J. (1978a) Studies of Australian soft corals. IX. A novel nor-diterpene from the soft coral Sinularia leptoclados. Aust. J. Chem., 31, 2049-2056. 

Rodriguez, A.D., Ramirez, C., and Rodriguez, I.I. (1999b) Sandresolides A and B novel nor-diterpenes from the sea whip Pseudopterogorgia elisabethae (Bayer). Tetrahedron Lett., 40, 7627-7631. 

Chabrolol B is a member of a group of three atypical tri-nor-diterpenes (C17) isolated from the alcyonacean Nephthea chabroli harvested in the China Sea. 

The species Nephthea chabrolii (China) contains a series of three tri-nor-diterpenes derived from one of these skeletons. 

A few other tricyclic diterpenes have been isolated, almost all of them from species of Sinularia, a genus that is an excephonal source of sesqui- and diterpenes. The following three examples are nor-diterpenes. Yonarolide and scabrohdes A and B seem to be the only natural representatives of this tricyclo[7,5,0,0 ]tetradecane, and the name yonarane has been proposed for this new carbon skeleton. Ineleganolide and horiolide are two other examples of nor-diterpenic lactones with an original carbon skeleton. 

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