Diterpenoids from the South China Sea soft coral Sarcophyton solidum

Chemical investigation of the South China Sea soft coral Sarcophyton solidum has led to the isolation of one new (1) and seven known (2–8) diterpenoids, including three sarsolenanes (1–3), two capnosanes (4 and 5), and three cembranes (6–8). Sarsolilide B (4) was firstly confirmed by single-crystal X-ray diffraction. Compounds 1, 3, 4, and 6–8 were isolated from S. solidum for the first time, and 1, 2, and 4–7 were considered as the chemotaxonomic markers for the species S. solidum.     

Chemical constituents of soft coral Sarcophyton infundibuliforme from the South China Sea

Chemical investigation on soft coral Sarcophyton infundibuliforme collected from the South China Sea led to the isolation and identification of 14 secondary metabolites, including ten cembrene diterpenoids (1–10), one α-tocopheryl quinone derivative (11), one prostaglandin (12), one lipid (13) and one carotinoid (14). Their structures were determined by extensive analysis of their spectroscopic data. All of these metabolites were isolated from this species for the first time. Diterpenoids 1, 2, 7 and 10 showed potent antifouling activity against the larval settlement of barnacle Balanus amphitrite.     

Crassocolides N-P, three cembranoids from the Formosan soft coral Sarcophyton crassocaule

Three new cembranoids crassocolides N-P (1-3), was isolated from the organic extract of a Formosan soft coral Sarcophyton crassocaule. These structures were elucidated on the basis of spectroscopic analyses and by comparison with those previously reported in literature. The cytotoxicity of these compounds toward various cancer cell lines has also been determined.     

Cytotoxic and anti-inflammatory cembranoids from the Dongsha Atoll soft coral Sarcophyton crassocaule

Five new cembranoids, sarcocrassocolides A–E (1–5), along with three known cembranoids 6–8, have been isolated from a Formosan soft coral Sarcophyton crassocaule. The structures of the new metabolites were elucidated by extensive spectroscopic analysis and the absolute configuration of 1 was determined by a modified Mosher’s method. Compounds 1–4 exhibited significantly cytotoxic activity against a limited panel of cancer cell lines. Compounds 1–4, 6 and 8 were shown to exert significant in vitro anti-inflammatory activity in LPS-stimulated RAW264.7 macrophage cells. Compound 6 also significantly inhibited the accumulation of pro-inflammatory COX-2 protein.     

Trochelioid A and B,new cembranoid diterpenes from the Red Sea soft coral Sarcophyton trocheliophorum

Chemical investigations of the soft coral Sarcophyton trocheliophorum, has led to the isolation of six cembranoids, two of which are new, Trochelioid A (1) and B (2), and one, 16-oxosarcophytonin E (3) isolated from nature for the first time. Additionally, two have been isolated from S. trocheliophorum for the first time (4 and 6). Structures were elucidated by employing extensive NMR and HR-FAB-MS experimentation.     

Marine sterols X. Minor constituents of the sterols of the soft coral Sarcophyton glaucum

The sterol mixture of the southern Japan soft coral $\text{Sarcophyton glaucum}$ was found to contain a variety of minor components overlooked in a previous study. Five 4α-methylsterols ($\text{1}$ to $\text{5}$) and three 4-demethyl-sterols ($\text{6}$ to $\text{8}$) were isolated and their structures were confirmed.     

A molecular phylogenetic analysis of reproductive trait evolution in the soft coral genus Alcyonium

The soft coral genus Alcyonium is among the most reproductively diverse invertebrate taxa known: The genus includes species that vary both in mode of reproduction (including broadcast spawners, internal brooders, and external brooders) and sexual expression (gonochores, hermaphrodites, and a unisexual parthenogen). Such diversity offers a unique opportunity to examine associations between reproductive and morphological traits in a phylogenetic context. We used an approximately 900-bp sequence of the nuclear ribosomal gene complex spanning the internal transcribed spacer (ITS) regions to construct a molecular phylogeny for 14 European and North American species of Alcyonium onto which we mapped the known distribution of reproductive and morphological traits. The phylogeny suggests that hermaphroditism or parthenogenesis has evolved independently at least twice in this genus, and always in internally brooding species. Broadcast spawning and external brooding only occur in species with large colony size, whereas all species with small colony size brood their larvae internally. Internal brooding and small size appear to be ancestral in this genus; if this is the case, an association between broadcast spawning and large colony size has evolved independently in at least two clades. This tendency of small adults to brood their larvae while large adults broadcast spawn them into the plankton has been observed in a variety of solitary invertebrate taxa, but to date has not been documented in any other colonial invertebrates. Moreoever, it has been suggested that organisms with a colonial growth form should not experience the allometric constraints on brood space that have been proposed to explain the association between adult size and mode of reproduction in solitary organisms. Unlike many other colonial groups, however, module (polyp) size is strongly correlated with colony size in Alcyonium, and constraints on brooding may be imposed by module, rather than colony, allometry. The very close genetic relationship (< 1% sequence divergence) and shared polymorphisms among A. digitatum (a large, gonochoric broadcast spawner), A. siderium, and A. sp. A (intermediate-sized and small hermaphroditic, internal brooders) suggest that evolutionary transitions between broadcast spawning and brooding and between gonochorism and hermaphroditism can occur easily and rapidly in this group.     

Phylogenetic relationships within the tropical soft coral genera Sarcophyton and Lobophytum (Anthozoa, Octocorallia)

Abstract. The alcyonacean soft coral genera Sarcophyton and Lobophytum are conspicuous, ecologically important members of shallow reef communities throughout the Indo-West Pacific. Study of their ecology is, however, hindered by incomplete knowledge of their taxonomy: most species cannot be identified in the field and the two genera cannot always be distinguished reliably. We used a 735-bp fragment of the octocoral-specific mitochondrial protein-coding gene msh1 to construct a phylogeny for 92 specimens identified to 19 species of Lobophytum and 16 species of Sarcophyton . All phylogenetic methods used recovered a tree with three strongly supported clades. One clade included only morphologically typical Sarcophyton species with a stalk distinct from the polypary, poorly formed club-shaped sclerites in the colony surface, and large spindles in the interior of the stalk. A second clade included only morphologically typical Lobophytum colonies with lobes and ridges on the colony surface, poorly formed clubs in the colony surface, and interior sclerites consisting of oval forms with regular girdles of ornamental warts. The third distinct clade included a mix of Sarcophyton and Lobophytum nominal species with intermediate morphologies. Most of the species in this mixed clade had a polypary that was not distinct from the stalk, and the sclerites in the colony surface were clubs with well-defined heads. Within the Sarcophyton clade, specimens identified as Sarcophyton glaucum belonged to six very distinct genetic sub-clades, suggesting that this morphologically heterogeneous species is actually a cryptic species complex. Our results highlight the need for a complete taxonomic revision of these genera, using molecular data to help confirm species boundaries as well as to guide higher taxonomic decisions.     

Cembrane diterpenoids from the soft coral Sarcophyton trocheliophorum Marenzeller as a new class of PTP1B inhibitors

A detailed investigation of the South China Sea soft coral Sarcophyton trocheliophorum Marenzeller yielded, along with six known terpenes (6?11), the new sarcophytonolides N?R (1?5), whose structures have been elucidated by detailed spectroscopic analysis. Sarcophytonolides N–R are mono- or bicyclic cembranoids characterized by the presence of three/four double bonds and oxidized methyl groups. Some of the isolated compounds showed significant inhibitory activity against human protein tyrosine phosphatase 1B (PTP1B) enzyme, a key target for the treatment of type-II diabetes and obesity, and some preliminary structure–activity relationships have been drawn. This is the first report on the anti-PTP1B activity of cembrane diterpenoids.     

Distribution of Sarcophytol A in Soft Coral of the Sarcophyton Genus

The distribution of sarcophytol-A in the Sarcophyton genus was investigated in seven samples belonging to S. glaucum (3 samples), S. infundibulifurme (2 samples), S. crassocaule (1 sample) and S. trocheliophorum (1 sample) that were collected on Ishigaki Island in Okinawa Prefecture. Sarcophytol-A was present in one sample each of S. glaucum and S. infundibulifurme. This study indicates that the composition of cembranoids in the Sarcophyton genus is not related with the respective species, but with the individual samples collected.     

Assessment of the phylogenetic analysis and antimicrobial,antiviral, and anticancer activities of marine endophytic Streptomyces species of the soft coral Sarcophyton convolutum

International Microbiology - In the present work, the extensive biological activities of marine endophytic Streptomyces strains isolated from marine soft coral Sarcophyton convolutum have been...     

A new genus of soft coral (Cnidaria,Octocorallia) from the Republic of Congo (Pointe-Noire Region)

A new genus of soft coral from the Republic of Congo is described, Complexum gen. n. Nine West African octocoral species previously described in the genus Alcyonium by Tixier-Durivault (1955) are referred to this new genus, and a new species is described and figured, Complexum pusillum sp. n. The new species is characterized by having encrusting growth form and abundant spiny clubs in the surface of the polyparium. It colonizes shallow calcareous rocky banks (5 to 20 m depth) existing in coastal water of the region of Pointe-Noire. Based on molecular phylogeny this new genus is well separated from Alcyonium species.     

Marine sterols. XII. Glaucasterol, a novel C27 sterol with a unique side chain, from the soft coral Sarcophyton glaucum

A minor C27 sterol, glaucasterol, was isolated from the soft coral Sarcophyton glaucum. Based on the spectroscopic evidence and the correlation to cholestanol and 26-nor-27-homocholestanol, its structure was proposed to be 24 epsilon,25 epsilon-24,26-cyclocholesta-5,22E-dien-3 eta-ol (1), the first example of a natural C27 sterol having a cyclopropane ring in the side chain.     

A new Carboniferous rugose coral genus from northern England

Pleionastraea gen. nov. of the family Lithostrotionidae is described from the Lower Carboniferous Brigantian Stage of northern England. Two species, P. magna P. matura , are referred to it. This astraeoid/thamnasterioid genus is distinguished from Orionastraea by its larger dimensions, but is considered to have followed the same evolutionary trend of a gradual breakdown of the corallite wall.     

A new 9,11-secosterol from the soft coral Sinularia granosa

Chemical investigations on the EtOAc-soluble fractions from the EtOH extract of Formosa soft coral afforded a new 9,11-secosteroid, 8αH-3β,11-dihydroxy-5α,6α-expoxy-24-methylene-9,11-secocholestan-9-one (1), along with one known steroid 3β,11-dihydroxy-5β,6β-expoxy-24-methylene-9,11-secocholestan-9-one (2) from Sinularia granosa. The structure of the new metabolite was elucidated on the basis of extensive spectroscopic analysis and by comparison of their NMR data with the known compounds, including 2. Both 1 and 2 were shown to significantly inhibit the accumulation of the pro-inflammatory inducible nitric oxide synthase protein, and 1 also was found to effectively reduce the level of cyclooxygenase-2 protein, in lipopolysaccharide-stimulated RAW264.7 macrophage cells at 10 μM. Furthermore, cytotoxic activity of 1 and 2 toward a limited panel of cancer cell lines was also discovered.     

A comparison between coral colonies of the genus Madracis and simulated forms

In addition to experimental studies, computational models provide valuable information about colony development in scleractinian corals. Using our simulation model, we show how environmental factors such as nutrient distribution and light availability affect growth patterns of coral colonies. To compare the simulated coral growth forms with those of real coral colonies, we quantitatively compared our modelling results with coral colonies of the morphologically variable Caribbean coral genus Madracis. Madracis species encompass a relatively large morphological variation in colony morphology and hence represent a suitable genus to compare, for the first time, simulated and real coral growth forms in three dimensions using a quantitative approach. This quantitative analysis of three-dimensional growth forms is based on a number of morphometric parameters (such as branch thickness, branch spacing, etc.). Our results show that simulated coral morphologies share several morphological features with real coral colonies (M. mirabilis, M. decactis, M. formosa and M. carmabi). A significant correlation was found between branch thickness and branch spacing for both real and simulated growth forms. Our present model is able to partly capture the morphological variation in closely related and morphologically variable coral species of the genus Madracis.     

Molecular evidence for the hybrid origin of species in the soft coral genus Alcyonium (Cnidaria: Anthozoa: Octocorallia)

Several recent studies have suggested that hybridization may play a previously unrecognized and important role in the evolution of corals. Our observations of polymorphic and recombinant sequences in the multicopy ribosomal internal transcribed spacer (ITS) region suggested the possible hybrid origin of two European soft coral species, Alcyonium hibernicum and Bellonella bocagei. To examine this possibility further we cloned and sequenced ITS-1 from multiple individuals and populations of these two species as well as two sympatric congeners, A. coralloides and A. sp. M2. Phylogenetic analyses separated the observed sequence variants into two distinct clades. All A. coralloides sequences belonged to clade A, while A. sp. M2 had only clade B sequences. A majority of A. hibernicum individuals, however, contained both clade A and B sequences that were identical to the predominant sequence variants found in A. coralloides and A. sp. M2, respectively. This pattern of additivity suggests that A. hibernicum originated from a hybrid cross between A. coralloides and A. sp. M2, a hypothesis that is supported by its unusual mode of reproduction (meiotic parthenogenesis). The predominant sequence variant found in B. bocagei was a unique, derived clade B sequence; in addition, however, most individuals of this species also had copies of a sequence identified as a recombinant between clade A and clade B sequence types. The presence of this recombinant sequence in the B. bocagei genome suggests that this species may also be the product of past hybridization events within the clade. Reticulate evolution may explain the failure of several previous studies to resolve the phylogeny of these four species.     

Steroids from the soft coral Dendronephthya sp

Fifteen steroids were isolated from the soft coral Dendronephthya sp., of which five are determined as new compounds, namely (22E)-3-O-beta-formylcholest-5,22-diene (1), (22E)-3-O-beta-formyl-24-methyl-cholest-5,22-diene (2), 2-ethoxycarbonyl-2-beta-hydroxy-A-nor-cholest-5-ene-4-one (3), (22E)-2-ethoxycarbonyl-2-beta-hydroxy-A-nor-cholest-5,22-diene-4-one (4), and (22E)-2-ethoxycarbonyl-2-beta-hydroxy-24-mthyl-A-nor-cholest-5,22-diene-4- one (5). 1 and 2 belonged to 3-O-formylated cholesterol analogues, and 3 to 5 are unique ring A-contracted steroids. Their structures were elucidated by extensive 2D NMR in association with IR, MS analysis.