Dolabellane Diterpenes and Elemane Alkaloids from the Soft Coral Clavularia inflata Collected in the South China Sea.

Five new dolabellane diterpenes, clavularinlides A-E (1-5), and four new racemic elemane alkaloids, clavulacylides A-D (7-10), together with one known compound (6), were isolated from the soft coral Clavularia inflata collected in the South China Sea. Their structures were elucidated by 1D and 2D NMR, HRESIMS, calculated ECD, and DP4+ probability analyses. Compounds 1-7 showed anti-inflammatory activity in the zebrafish assay.

Terpenoids from the Soft Coral Sinularia sp. Collected in Yongxing Island.

Three new sesquiterpenoids (sinuketal (1), sinulins A and B (2 and 3)) and two new cembranoids (sinulins C and D (4 and 5)), as well as eight known sesquiterpenoids (6–13) and eight known cembranoids (14–21), were isolated from the Xisha soft coral Sinularia sp. Their structures were elucidated by extensive spectroscopic analysis. Compound 1 possesses an unprecedented isopropyl-branched bicyclo [6.3.0] undecane carbon skeleton with unique endoperoxide moiety, and a plausible biosynthetic pathway of it was postulated. According to the reported biological properties of endoperoxide, the antimalarial, cytotoxic, antiviral, and target inhibitory activities of 1 were tested. Compound 1 showed mild in vitro antimalarial activity against Plasmodium falciparum 3D7, weak cytotoxic activities toward Jurkat, MDA-MB-231, and U2OS cell lines, inhibitory effects against influenza A viruses H1N1 and PR8, as well as mild target inhibitory activity against acetylcholinesterase. The other compounds were evaluated for cytotoxicities against HeLa, HCT-116, and A549 tumor cell lines and target inhibitory activities against protein tyrosine phosphatase 1B (PTP1B). Compound 20 exhibited cytotoxicities against HeLa and HCT-116, and compounds 5, 11, and 15 showed mild target inhibitory activities against PTP1B.

Metabolites from the Paracel Islands Soft Coral Sinularia cf. molesta.

Five new oxygenated sesquiterpenes, molestins A⁻D (1, 3⁻5) and epi-gibberodione (2), three new cyclopentenone derivatives, ent-sinulolides C, D, and F ((+)-9⁻(+)-11), one new butenolide derivative, ent-sinulolide H ((+)-13), and one new cembranolide, molestin E (14), together with 14 known related metabolites (6⁻8, (⁻)-9⁻(⁻)-11, (±)-12, (⁻)-13, 15⁻19) were isolated from the Paracel Islands soft coral Sinularia cf. molesta. The structures and absolute configurations were elucidated based on comprehensive spectroscopic analyses, quantum chemical calculations, and comparison with the literature data. Compound 5 is the first example of a norsesquiterpene with a de-isopropyl guaiane skeleton isolated from the genus Sinularia. Molestin E (14) exhibited cytotoxicities against HeLa and HCT-116 cell lines with IC50 values of 5.26 and 8.37 µM, respectively. Compounds 4, 5, and 8 showed significant inhibitory activities against protein tyrosine phosphatase 1B (PTP1B) with IC50 values of 218, 344, and 1.24 µM, respectively.

An unusual spinaceamine-bearing pregnane from a soft coral Scleronephthya sp. inhibits the migration of tumor cells.

An unprecedented spinaceamine-bearing pregnane namely scleronine (1) was isolated from a Chinese soft coral Scleronephthya sp. Its structure was determined on the basis of 1D and 2D NMR spectroscopic analyses in association with the HRESIMS data, while the absolute configurations were deduced by the single-crystal X-ray diffraction analysis. In addition, a dehydrogenated analogue (3) was synthesized through six steps with pregna-1,20-dien-3-one (2) as a precursor. The significantly inhibitory effects of 1 and 3 against the migration of tumor cells A549 and B16 accompanying the down-regulation of key genes (TGFß, TNFα, IL-1ß, and IL-6) were observed. These findings suggested that both 1 and 3 are potential for therapeutic usage aiming at cancer metastasis inhibition.

Halogenated Briarane Diterpenes with Acetyl Migration from the Gorgonian Coral Junceella fragilis.

Chemical examination of the gorgonian coral Junceella fragilis resulted in the isolation of four pairs of acetyl isomers belonging to briarane diterpenoids, including five new compounds. Their structures were determined on the basis of extensive spectroscopic (IR, MS, NMR, and single-crystal X-ray diffraction) analysis in association with the chemical conversion. Each pair of isomers featured by dynamical interconversion through as acetyl migration in 1,2-diol, which was postulated to be generated under the formation of a cyclic orthoacetate intermediate. All compounds exerted the inhibitory activities against the nitric oxide production in RAW264.7 macrophage cells.

Cyclopentenone derivatives and polyhydroxylated steroids from the soft coral Sinularia acuta.

Four new polyhydroxylated steroids, 1-4, and the racemic form of cyclopentenone 9, together with four known steroids, 5-8, one known cyclopentenone derivative, 10, and one known butenolide derivative, 11, were isolated from the soft coral Sinularia acuta collected from Weizhou Island of Guangxi Province, P. R. China. Their structures were elucidated on the basis of spectroscopic analyses and by comparison of the corresponding data with those previously reported. The cytotoxicities of the isolates 1-11 in vitro against the selected tumor cell lines HL-60, HeLa, and K562 were evaluated. Compounds 2 and 5 showed potent cytotoxicities against HL-60 cell lines with IC50 values of 7.3 and 9.9 µM, respectively. Compounds 5 and 6 showed moderate activities against K562 cell lines with IC50 values of 10.9 and 11.7 µM, respectively, while compounds 1, 2, and 6 showed weak activities against HeLa cell lines with respective IC50 values of 44.8, 27.1, and 18.2 µM. This is the first report on chemical and bioactivity research of S. acuta.

Asteriscane-type sesquiterpenoids from the soft coral Sinularia capillosa.

Chemical examination of the soft coral Sinularia capillosa collected from the South China Sea resulted in the isolation of 14 new asteriscane-type sesquiterpenoids, namely, capillosananes A-N (1-14), four new seco-asteriscanes, capillosananes O-R (15-18), and (-)-sinularone A and sinularone A. Their structures were determined on the basis of extensive spectroscopic analyses, while the absolute configurations were determined by CD and ECD calculation, Mosher's method, and chemical conversion. This is the first report of asteriscane-type sesquiterpenoids from soft corals, and capillosananes Q (17) and R (18) represent new seco-asteriscane skeletons. Capillosanane A exhibited potent antifouling activity against Balanus amphitrite, with an IC50 value of 9.70 µM, while capillosananes B and I and (-)-sinularone A inhibited inflammation-related TNF-α in vitro.

Sarcophyolides B-E, new cembranoids from the soft coral Sarcophyton elegans.

Four new cembrane-type diterpenoids, sarcophyolides B-E (1-4), along with 11 known analogues were isolated from the soft coral Sarcophyton elegans. The structures of new compounds 1-4 were established on the basis of spectroscopic analysis and chemical conversion. The new cembranoids sarcophyolides B (1) and lobocrasol were found to exhibit potent inhibition against A2780 human ovarian tumor cells.

Non-native coral species dominate the fouling community on a semi-submersible platform in the southern Caribbean.

A coral community was examined on a semi-submersible platform that was moored at the leeward side of Curaçao, in the southern Caribbean, from August 2016 until August 2017. This community included several non-native or cryptogenic species. Among them were two scleractinian corals (Tubastraea coccinea and T. tagusensis) and two octocorals (Chromonephthea sp. and an unidentified Nephtheidae sp.). This is the first reported presence of T. tagusensis in the southern Caribbean, and the genus Chromonephthea in the Caribbean region. An ascidian, Perophora cf. regina, is also reported from the southern Caribbean for the first time, as well as a coral-associated vermetid gastropod, Petaloconchus sp., first recorded in the Caribbean in 2014. Lack of biofouling management could potentially harm indigenous marine fauna through the introduction of non-native species. Therefore monitoring communities associated with semi-submersible platforms is essential to track the presence and dispersal of non-native, potentially invasive species.

Antifouling eunicellin-type diterpenoids from the gorgonian Astrogorgia sp.

Twelve new eunicellin-based diterpenoids, astrogorgins B-M (1-12), were isolated from a Chinese gorgonian Astrogorgia sp., together with ophirin, muricellin, astrogorgin, calicophirins A and B, and 14-deacetoxycalicophirin B. The structures of the new compounds were elucidated by extensive spectroscopic analysis and by comparison with data reported in the literature. Significant antifouling activity was observed for 14-deacetoxycalicophirin B against the larval settlement of the barnacle Balanus amphitrite at nontoxic concentrations with an EC(50) = 0.59 µg/mL, while the other analogues were effective within an EC(50) range of 5.14-17.8 µg/mL.

Sinularones A-I, new cyclopentenone and butenolide derivatives from a marine soft coral Sinularia sp. and their antifouling activity.

Nine new compounds, namely sinularones A-I (1-9), characterized as cyclopentenone and butenolide-type analogues, were isolated from a soft coral Sinularia sp., together with a known butenolide (10). Their structures were elucidated by means of spectroscopic (IR, MS, 1D and 2D NMR, CD) analysis. The absolute configurations were determined on the basis of CD and specific rotation data in association with the computed electronic circular dichroism (ECD) by time dependent density functional theory (TD DFT) at 6-31+G(d,p)//DFT B3LYP/6-31+G(d,p) level. Compounds 1-2 and 7-10 showed potent antifouling activities against the barnacle Balanus amphitrite.

9,10-secosteroids, protein kinase inhibitors from the Chinese gorgonian Astrogorgia sp.

Fourteen new 9,10-secosteroids designated as astrogorgols A-N (1-14) were isolated from a Chinese gorgonian Astrogorgia sp. together with eight known analogues. The structural patterns were characterized by the presence of a sterol-based 9,10-seco nucleus containing a 3-hydroxy-10-methylphenyl ring. Astrogorgol N (14) possessing a 1,4-dien-3-one unit in ring A was biogenetically considered as an intermediate to generate diverse 9,10-secosteroids. Five compounds showed significant inhibitory activities against human tumor related protein kinases, including ALK, AXL, FAK, IGF-1R, MET wt, SRC, and VEGF-R2.

Lobophytones U - Z1, biscembranoids from the Chinese soft coral Lobophytum pauciflorum.

Chemical examination of a Chinese soft coral Lobophytum pauciflorum resulted in the isolation of seven new biscembranoids named lobophytones U-Z(1) (1-7, resp.), together with methyl sartortuoate (8) and nyalolide (9). The structures of the new compounds were elucidated by 1D- and 2D-NMR (COSY, HSQC, HMBC, and NOESY) spectroscopic analysis in association with MS and IR data. All compounds were tested against lipopolysaccharide (LPS)-induced nitric oxide (NO) release in mouse peritoneal macrophage. Lobophytone Z (6) inhibited NO production with an IC(50) value of 2.6 µM. Lobophytone H (1) showed inhibitory activities against the bacteria S. aureus and S. pneumoniae.

Rhodolitica on rhodoliths: a new stoloniferan genus (Anthozoa, Octocorallia, Alcyonacea).

Rhodolitica occulta gen. nov. et sp. nov. (Clavulariidae) is described from Cocos Island National Park, Pacific Ocean, Costa Rica. The species was found at various islets and rocky outcrops around the island, 20-55 m in depth. The genus is characterised by tubular, single, erect anthosteles interconnected by thin basal ribbon-like stolons on the surfaces of living rhodoliths. The anthosteles are devoid of fused sclerites, which are only present in the stolons. Coenenchymal sclerites are mostly spindles of various shapes, with a characteristic cylindrical warty type in the outer layer, crosses and radiates. Anthocodiae are armed with points, lacking collarets. Colonies and sclerites are red. Using an integrative taxonomic approach, we separate the new genus from similar genera through both morphological comparison and a molecular phylogenetic analysis. This research is a contribution to the knowledge of the octocoral biodiversity in Cocos Island and marine biodiversity in the eastern tropical Pacific.

Sesquiterpenoids from the soft coral Lemnalia sp.

Two new neolemnane-type sesquiterpenoids lemnolins A (1) and B (2), together with one known tricyclic sesquiterpenoid (3) were isolated from the South China Sea soft coral Lemnalia sp. The structures were elucidated by comprehensive spectroscopic analysis and ECD analysis. Compound 1 displayed antiviral activity against influenza A (H1N1) virus in vitro.

Terpenoids from the South China Sea soft coral Sinularia multiflora.

A rare sinulariane-type norcembranoid sinulariadiolide B (1) with a unique cyano group, and a eunicellin-based diterpenoid multifloralin (2), along with two known related analogues, sinulariadiolide (3) and sclerophytin E (4), were isolated from the extract of the South China Sea soft coral Sinularia multiflora. Their structures were elucidated on the basis of detailed spectroscopic analysis and by comparison with previously reported data. Compounds 2 and 4 showed potent antifouling activity against barnacle Balanus albicostatus.

Lobophytones O-T, new biscembranoids and cembranoid from soft coral Lobophytum pauciflorum.

Chemical examination of a Chinese soft coral Lobophytum pauciflorum resulted in the isolation of five new biscembranoids named lobophytones O-S (1-5) and a new "monomeric" cembrane lobophytone T (6). The structures of the new compounds were elucidated by interpretation of 1D and 2D NMR (COSY, HSQC, HMBC, and NOESY) spectroscopic data in association with MS and IR data. Lobophytone Q showed significant inhibition against lipopolysaccharide (LPS)-induced nitric oxide (NO) release in mouse peritoneal macrophages, while lobophytones Q and T showed inhibitory activities against the bacteria S. aureus and S. pneumoniae.

Lobophytones H-N, Biscembranoids from the Chinese soft coral Lobophytum pauciflorum.

Chemical examination of a Chinese soft coral Lobophytum pauciflorum resulted in the isolation of seven new biscembranoids, named lobophytones H-N (1-7). Their structures were determined by interpretation of 1D- and 2D-NMR (correlation spectroscopy (COSY), heteronuclear single quantum coherence (HSQC), heteronuclear multiple bond connectivity (HMBC), and nuclear Overhauser effect spectroscopy (NOESY)) spectroscopic data in association with MS and IR data. All compounds were tested for the inhibition of lipopolysaccharide (LPS)-induced nitric oxide (NO) production, cytotoxicity of mouse peritoneal macrophage, and antibacterial activities.

The genus Litophyton Forskål, 1775 (Octocorallia: Alcyonacea: Nephtheidae) from Australia.

The Litophyton species of Australia are described. Of the 33 species dealt with three were previously described and 30 are considered new. For convenience the species described are divided into five distinct morphological groups. The new species are compared with previously described species from neighbouring Indonesia. L. pyramidalis (Kükenthal, 1895) is synonymized with L. elongatum (Kükenthal, 1895).

Corrigenda: Hanah, a replacement name for Hana Lau, Stokvis, Ofwegen & Reimer, 2018 (preoccupied name).

[This corrects the article DOI: 10.3897/zookeys.790.28875.].