Sarcophyton

Anthozoa Alcyonaria Alcyonacea Alcyonidae Sarcophyton glaucum... 

Ne eman I, Fishelson L, Kashman Y, Sarcophine. New toxin from the soft coral Sarcophyton glaucum PAcyonsena) Toxicon 12 593—598, 1974. 

Chang-Yih D, Rei-Sheu H, Cytotoxic cembranoids from the soft corals Sinularia gibberosa and Sarcophyton trocheliophorum, J Nat Prod 59 595—598, 1996. 

Sarcophyton glaucum is a common soft coral of the Red Sea, Pacific, and other coral reefs. In 1974, Kashman and co-workers67 reported the furanocembranoid diterpene sarcophine (45) from S. glaucum with a remarkable yield of up to 3% dry weight, and suggested that sarcophine constitutes the major chemical defense against natural predators. 

Bowden, B. F., Coll, J. C., Hicks, W., Kazlauskas, R., and Mitchell, S. J., Studies of Australian soft corals X the isolation of epoxyisoneocembrene-A from Sinularia grayi isoneocembrene-A from Sarcophyton ehrenbergi, Aust. J. Chem., 31, 2702, 1978. 

Class Subclass Order Suborder Family Genus Lithophyton Lobophytum Minabea Paraerythropodium Sarcophyton Sinularia... 

Some nudibranchs have adapted to feed on soft corals,270 273 ascidians,274 bryozoans,275 or on other molluscs rather than sponges. The mollusc Ovula ovum was reported to sequester the toxic sarcophytoxide (Structure 2.151) from Sarcophyton sp. and transform it into the less toxic terpene (Structure 2.152),276 but the deoxy metabolite was subsequently found in the soft coral.277... 

PROGRESS OF STUDIES ON THE NATURAL CEMBRANOIDS FROM THE SOFT CORAL SPECIES OF SARCOPHYTON GENUS... 

Sarcophyton, and Sinidaria are the most prolific. This review mainly pertains to the cembrane-type constituents of the soft corals of the Sarcophyton genus. 

CEMBRANE-TYPE CONSTITUENTS FROM THE SARCOPHYTON GENUS... 

Sarcophyton species contain diterpenes up to 10% of their dry weight, and this large quantity of secondary metabolites plays an important role in the survival of Octo-corals with defensive, competitive, reproductive, and possibly pheromonal functions. Soft corals lacking physical defense thus seem to be protected from predation by the presence of diterpene toxins in their tissue. Nearly 25 species of this genus occurring in different seawaters have been examined chemically so far, and more than 80 cembranoid diterpenes have been isolated from the Sarcophyton genus since the 1970s. 

Up to 20 sarcophytols were isolated from the Sarcophyton genus with the name of sarcophytol from A to T (except sarcophytol L, including two sarcophytol T) (Figure 6-2). 

Chemical examination of Sarcophyton glaucum collected at Ishigaki island, Okinawa Prefecture, resulted in the isolation of seven cembranoid diterpenes, namely sarcophytol A (3), sarcophytol A acetate (4), sarcophytol B (5), sarcophy-tonin A (6), and minor constituents sarcophytol C (7), D (8), and E (9). These compounds were found to be susceptible to autooxidation while being purified. The structural determination of these compounds was made mainly based on proton and carbon nuclear magnetic resonance (NMR) spectral evidence and degradative studies by ozonolysis. X-ray crystallographic analysis for the two crystalline compounds, sarcophytol B (5) and D (8), has been reported. The total lipid extracts of S. glaucum comprise about 40% sarcophytol A (3), 5% each of sarcophytol A acetate (4) and sarcophytonin A (6), about 1% sarcophytol B (5), and minor amounts of sarcophytol C (7), D (8), and E (9). 

The Other Cembrane-Type Constituents from the Sarcophyton Genus... 

A new epoxy-bridged cembranoid diterpene 49 possessing antifouling activity was reported from an unidentified Thai soft coral species of the Sarcophyton genus, whose structure was assigned by NMR and NMR experiments. Two new cembranoids, 50 and 51, which showed cytotoxic activity on ehrlichacities tumor... 

Two novel irregular cembranoids possessing a 13-membered carbocyclic skeleton, sarcotol (83), and sarcotal acetata (84) were reported from another unidentified Sarcophyton species (Figure 6-8), whose structures were determined by spectroscopic and single-crystal x-ray analyses and chemical conversion." " ... 

C (27) was first isolated as a component of oleoresin of Finns koraiensis by Raldugin in 1971, but its structure was not confirmed. In 1978, Vanderah et al. isolated it from the soft coral Nephthea spp. and established its structure as ( , , , )-l,7,ll-trimethyM-isopropyl-l,3,7,ll-cyclotetradecatetraene. It was also found in another soft coral Sarcophyton ehrenbergi afterward. Cembrene C (27) was synthesized in a trace amount by isomerization of naturally occurring cembrene A (59) (Scheme 6-9). 

Sarcophytonin B (67) was first isolated from Sarcophyton spp. by Kobayashi and Hirase in 1990. cis- and trarw-Cembranolides were isolated from Sinularia mayi by Uchio et al. (Scheme 6-33). and from Lobophytum michaelae by Coll et al. Cembranolides were assumed to be logical biosynthetic precursors of sarcophytonin B. Several syntheses of the cembranolides and sarcophytonin B (67) have been reported. 

A number of cembranoid diterpenoids have been isolated from corals. These include (128) from a South Pacific soft coral/ trocheliophorol (129) from Sarcophyton trocheliophorium, " flexibilide (=sinularin) (130) from Sinularia flexibilis, and isosarcophytoxide (131) and the corresponding diepoxide from a Sarcophyton species.A norcembrane (132) has been isolated from Sinularia... 

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