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Microbes in the coral holobiont play important roles in nitrogen fixation, carbon supply, antibiotic production, mucus recycling, and food supply to maintain homeostasis in corals. However, microbes can also induce coral diseases in response to environmental changes under non-optimal conditions. Therefore, studies of microbial communities are needed to understand the health statuses of corals in response to environmental changes. In this study, we performed 16S rDNA metabarcoding to investigate the bacterial communities in two healthy alcyonacean soft coral species (Sinularia sp. and Litophyton sp.) inhabiting the coast of Weno Island (Chuuk, Micronesia) and in ambient seawater. We identified 18 bacterial phyla, 24 classes, 54 orders, 109 families, and 222 genera associated with the two corals and seawater. The bacterial communities differed in the corals and seawater. The bacterial community in Sinularia sp. was dominated by the genus Spirochaeta in Spirochaetaceae (63.9% relative abundance), followed by Endozoicomonas (10%). In Litophyton sp., the bacterial community also contained Spirochaeta (19.5%) and Endozoicomonas (4.7%), although Cellvibrionaceae (23.7%) was dominant and other groups such as Rhizobiales (11.5%) and Rhodospirillales (8.7%) were evenly distributed. In ambient seawater, the predominant bacteria were Pelagibacter (29.2%), Rhodobacteraceae (15.5%), Prochlorococcus (11.3%), and Vibrio (5.8%), which are distinct from the species in the two coral species. The microbial communities between the two alcyonacean soft corals and seawater were different, and the microbial community differences were coral species-specific.

A novel norditerpenoid, sinusiaetone A (1), featuring an uncommon bicyclo[11.3.0]hexadecane carbon skeleton, and four polyoxygenated cembranoids (2-5) were isolated from the Hainan soft coral Sinularia siaesensis. Their structures were established by spectroscopic analysis, X-ray diffraction, quantum chemical computational approaches, and/or a modified Mosher's method. A plausible biosynthetic pathway of 1 and its biogenetic relationship with 2-5 were proposed. New compounds 1-3 displayed an interesting inhibitory activity against lipopolysaccharide-induced inflammation in BV-2 microglial cells.

An extract of a Sinularia sp. soft coral showed inhibitory activity against the E3-ubiquitin ligase casitas B-lineage lymphoma proto-oncogene B (Cbl-b). Subsequent bioassay-guided separation of the extract provided a series of terpenoid-derived spermidine and spermine amides that were named sinularamides A–G (1–7). Compounds 1–7 represent new natural products; however, sinularamide A (1) was previously reported as a synthetic end product. The structures of sinularamides A–G (1–7) were elucidated by analysis of spectroscopic and spectrometric data from NMR, IR, and HRESIMS experiments and by comparison with literature data. All of the isolated compounds showed Cbl-b inhibitory activities with IC(50) values that ranged from approximately 6.5 to 33 μM.

The chemical investigation of the South China Sea soft coral Sinularia humilis has resulted in the isolation of a library of diverse diterpenoids, including four new cembranoids, namely, humilisins A-D (1-4), two new uncommon diterpenoids possessing a tetradecahydrocyclopenta[3',4']cyclobuta[1',2':4,5]cyclonona[1,2-b]oxirene ring system, namely, humilisins E and F (5 and 6), and eight known related compounds (7-14). Humilisin A (1) is the first cembranoid with an ether linkage between C-3 and C-7. The structures and absolute configurations of 1-8 were determined by extensive spectroscopic data analyses, chemical reactions, and a series of quantum chemical calculations including quantum mechanical-nuclear magnetic resonance (QM-NMR), time-dependent density functional theory-electronic circular dichroism (TDDFT-ECD), and optical rotatory dispersion (ORD) methods. In bioassay, compound 6 displayed anti-inflammatory activity in lipopolysaccharide (LPS)-stimulated BV-2 microglia cells.

Five new tyrosine derivatives (1-5), one new phenylacetic acid derivative (6), two new quinazolinone analogues (7 and 8), one new naphthalenedicarboxylic acid (9), and one new 3,4-dihydroisocoumarin derivative (10), together with seven known compounds, were isolated from the fungus Xylaria sp. FM1005, which was isolated from Sinularia densa (leather coral) collected in the offshore region of the Big Island, Hawaii. The structures of compounds 1-10 were elucidated by extensive analysis of NMR spectroscopy, HRESIMS, and ECD data. Due to their structure similarity to the antiplatelet drug tirofiban, compounds 1-5 together with 6 were investigated for their antithrombotic activities. Compounds 1 and 2 strongly inhibited the binding of fibrinogen to purified integrin IIIb/IIa in a dose-dependent manner with the IC50 values of 0.89 and 0.61 μM, respectively, and compounds 1 and 2 did not show any cytotoxicity against A2780 and HEK 293 at 40 μM.

A new diterpenoid with an unusual capnosane skeleton, sinuhumilol A (1), alone with twelve known diverse compounds (2-13), were isolated from the South China Sea soft coral Sinularia humilis. Their structures and stereochemistry were elucidated by extensive spectroscopic analysis, quantum chemical calculations, and/or by the comparison of the spectroscopic data with those reported in the literature. In bioassay, compound 11 exhibited interesting specific cytotoxicity against the human colon adenocarcinoma cell line HT-29 with IC50 value of 12.5 µM.

Changes in the microbial community associated with environmental impacts can lead to opportunistic infections, coral disease and death. Diversity analysis and community comparison were performed on 23 collected soft Coral specimens from South China See surrounding Hainan Province (China) based on Illumina MiSeq sequencing. The results showed that Proteobacteria was the main symbiotic bacteria in soft corals. In the same geographical location, the diversity and abundance of symbiotic bacteria in the genus Sinularia are higher than genus Sarcophyton. Unlike Sinularia, the genus Sarcophyton is more inclined to Tenericutes. Furthermore, the same coral species has different bacterial community structure in different environments. The temperature difference between sampling points at 2 ℃ is the main factor affecting the results. A large number of Endozoicomonas found in stone corals have not become the dominant bacteria associated with soft corals. Coral-related pathogenic bacteria were not found in this investigation. This study provided a baseline for future studies of soft coral microbiomes, and assessment of functions of host metabolites and soft coral holobionts. Our result documented that same coral species in each locality represent identical pattern of bacterial diversity and community.

As coral populations decline worldwide in the face of ongoing environmental change, documenting their distribution, diversity and conservation status is now more imperative than ever. Accurate delimitation and identification of species is a critical first step. This task, however, is not trivial as morphological variation and slowly evolving molecular markers confound species identification. New approaches to species delimitation in corals are needed to overcome these challenges. Here, we test whether target enrichment of ultraconserved elements (UCEs) and exons can be used for delimiting species boundaries and population structure within species of corals by focusing on two octocoral genera, Alcyonium and Sinularia, as exemplary case studies. We designed an updated bait set (29,181 baits) to target-capture 3,023 UCE and exon loci, recovering a mean of 1,910 ± 168 SD per sample with a mean length of 1,055 ± 208 bp. Similar numbers of loci were recovered from Sinularia (1,946 ± 227 SD) and Alcyonium (1,863 ± 177 SD). Species-level phylogenies were highly supported for both genera. Clustering methods based on filtered single nucleotide polymorphisms delimited species and populations that are congruent with previous allozyme, DNA barcoding, reproductive and ecological data for Alcyonium, and offered further evidence of hybridization among species. For Sinularia, results were congruent with those obtained from a previous study using restriction site associated DNA sequencing. Both case studies demonstrate the utility of target-enrichment of UCEs and exons to address a wide range of evolutionary and taxonomic questions across deep to shallow timescales in corals.

The complete mitochondrial genome of Sinularia penghuensis was sequenced and analyzed using next-generation sequencing. The present mitochondrial genome was 18730 bp in length, containing 14 protein-coding genes (PCGs) (cox1-cox3.nad1-nad6, nad4L, atp6, atp8, cytb, and MutS), two ribosomal RNA genes (rRNAs) (12S and 16S), and one transfer RNA gene (Met-tRNA). The phylogenetic analysis of family Alcyoniidae revealed that S. penghuensis and Sinularia maxima cluster together. Five species in Sinularia reveals high identity in mitogenome sequences that the lowest variable sites (SNPs) were found between S. penghuensis and S. maxima.

Benzomalvins B, C, and E (1, 2, and 3) were simultaneously obtained from the marine fungus Aspergillus sp. isolated from the soft coral Sinularia sp., collected from South China Sea. Their structures were elucidated on the basis of NMR spectroscopic data and by comprehensive comparison with those previously reported in the literature. The stability of the double bond of E-benzomalvin B (1) under different light conditions was investigated, and 1 was transformed to Z-benzomalvin B (1′) with UV 365 nm irradiation. In particular, the incorrect 1H NMR data of 1′ in the literature was reassigned for the first time. Moreover, the absolute configuration of benzomalvin C (2) was also reported for the first time by X-ray single crystal diffraction.

The objective of the present study is to assess the status of the octocoral communities, and the extent of bleaching they suffered in 2016 (in line with the third Global Bleaching Event). Bleaching survey was carried out in the permanently fixed study sites in the 21 island of Gulf of Mannar. A focused study was carried out in Kariyachalli Island to monitor post-bleaching effects on octocorals. The overall octocoral cover in 2015 was 1.59±0.29%, and octocoral genera such as Sinularia, Sarcophyton, Lobophytum and Subergorgia were observed predominantly in GoM (Gulf of Mannar). Temperature reached a maximum of 32.5°C (March) during 2016 bleaching. The extent of bleaching in 2016 was 1.05±0.65% and the overall octocoral cover was reduced to 1.16±0.22%. Multiple paired t-test results indicate a significant variation in the octocoral covers between 2015 and 2016 (t = 3.173, p

Cancer and infectious diseases are notoriously known as deleterious health threats for the world, especially in the developing countries. The aim of the present study was to evaluate the cytotoxicity and antimicrobial activities of the methanolic extracts of the soft corals Nephthea elatensis, Heteroxenia fuscescens, Ellisella juncea, Dendronephthya mollis, and Sinularia hirta, that are native to the Red Sea in Egypt. The cytotoxicity assay was carried out by the enzymatic reduction of 3-[4,5-dimethylthiazole-2-yl]-2,5-diphenyltetrazolium bromide (MTT) assay against lung adenocarcinoma cell line (A549). Moreover, the antimicrobial activity was carried out against 11 human pathogenic bacterial and fungal strains using well-cut diffusion technique, while the Minimum Inhibitory Concentrations (MICs) were determined by microdilution method. Nephthea elatensis showed potent cytotoxicity [half maximal inhibitory concentration (IC50) 11.9 ± 1.2 µg/mL]. Also, it exhibited a potent antibacterial activity against Staphylococcus aureus(MIC 1.0 µg/mL). Sinularia hirta exhibited significant antimicrobial activities against Salmonella typhimurium and S. aureus (MIC 5.0 and 10.0 µg/mL, respectively). The results recommended N. elatensis and S. hirta as promising sources for new anticancer and antibiotic natural candidates.

Background: Soft corals of the genus Sinularia are well recognized as a rich source of steroidal compounds. These constituents have been reported as possessing antitumor, antimicrobial, and antiviral activities. Objectives: This study was designed to isolate and elucidate antibacterial and cytotoxic compounds from the soft coral Sinularia polydactila. Methods: Structure elucidation of steroids was determined based on spectroscopic data through 1D and 2D NMR analyses and mass spectrometry, with the results compared to data in the literature. Antibacterial activity was determined using four human bacterial pathogens, namely B. subtilis (ATCC 6633), P. aeruginosa (ATCC 27853), S. aureus (ATCC 25923), and E. coli (ATCC 25922). Cytotoxic activity was evaluated using the human colon cancer cell HCT 116 and brine shrimp lethality assay (BSLA). Results: Two steroids (Compounds 1 - 2) were isolated from the Indonesian soft coral Sinularia polydactila. (22R,23R,24R)-22,23-methylene-24-methylcholest-6-en-5α,8α-epidioxy-3β-ol (1) and 5α,8α-Epidioxy-24(R)-methylcholesta-6,22-dien-3α-ol (2) showed moderate activity against colon carcinoma cancer HCT 116 at the concentrations of 24.8 and 27.3 μg/mL, respectively. Furthermore, compounds 1 and 2 showed cytotoxic activity using the brine shrimp lethality assay with the concentrations of 57.1 and 121.3 3 μg/mL, respectively. Compound 2 showed moderate activity against S. aureus and B. subtilis at the 250 μg/mL concentration. Conclusions: Two steroids isolated from soft coral Sinularia polydactila were found to possess moderate cytotoxic and antibacterial activities.

Sinularia is one of the conspicuous soft coral species widely distributed in the world’s oceans at a depth of about 12 m. Secondary metabolites from the genus Sinularia show great chemical diversity. More than 700 secondary metabolites have been reported to date, including terpenoids, norterpenoids, steroids/steroidal glycosides, and other types. They showed a broad range of potent biological activities. There were detailed reviews on the terpenoids from Sinularia in 2013, and now, it still plays a vital role in the innovation of lead compounds for drug development. The structures, names, and pharmacological activities of compounds isolated from the genus Sinularia from 2013 to March 2021 are summarized in this review.

A pharmacophore-directed retrosynthesis strategy applied to rameswaralide provided simplified precursors bearing the common 5,5,6 (red) and 5,5,7 (blue) skeleton present in several cembranoid and n...

BackgroundOur ability to investigate processes shaping the evolutionary diversification of corals (Cnidaria: Anthozoa) is limited by a lack of understanding of species boundaries. Discerning species has been challenging due to a multitude of factors, including homoplasious and plastic morphological characters and the use of molecular markers that are either not informative or have not completely sorted. Hybridization can also blur species boundaries by leading to incongruence between morphology and genetics. We used traditional DNA barcoding and restriction-site associated DNA sequencing combined with coalescence-based and allele-frequency methods to elucidate species boundaries and simultaneously examine the potential role of hybridization in a speciose genus of octocoral,Sinularia.ResultsSpecies delimitations using two widely used DNA barcode markers,mtMutSand 28S rDNA, were incongruent with one another and with the morphospecies identifications, likely due to incomplete lineage sorting. In contrast, 12 of the 15 morphospecies examined formed well-supported monophyletic clades in both concatenated RAxML phylogenies and SNAPP species trees of >6,000 RADSeq loci. DAPC and Structure analyses also supported morphospecies assignments, but indicated the potential for two additional cryptic species. Three morphologically distinct species pairs could not, however, be distinguished genetically. ABBA-BABA tests demonstrated significant admixture between some of those species, suggesting that hybridization may confound species delimitation inSinularia.ConclusionsA genomic approach can help to guide species delimitation while simultaneously elucidating the processes generating diversity in corals. Results support the hypothesis that hybridization is an important mechanism in the evolution of Anthozoa, including octocorals, and future research should examine the contribution of this mechanism in generating diversity across the coral tree of life.

Three soft coral cuttings (finger soft coral, Sinularia sp.; black finger soft coral, Cladiella sp. and leather mushroom soft coral, Sarcophyton sp.) were selected to distinguish among the effects of five methods of attachment (adhering, containing, impaling, tethering and a natural attachment method used as a control) in a recirculating seawater system on healing time, time of self‐attachment, development of the cuttings and final survival. Three replicate and 30 cuttings per replicate (n = 30) were used for each treatment and the experimental period was 70 days. The results showed that the cuttings of Sinularia sp., Sarcophyton sp. and Cladiella sp. had already healed the wound area with pigmentation between 7 and 12 days for all the methods of attachment. The shortest time of self‐attachment for the Sinularia sp., Sarcophyton sp., and Cladiella sp. cuttings was obtained in the impaling method, with average values of 8.2 ± 0.9 days, 6.1 ± 0.1 days and 9.00 ± 0.8 days respectively. At the end of the experiment, the highest average final survival values of the Sinularia sp., Sarcophyton sp. and Cladiella sp. cuttings were obtained in the impaling method (86.7 ± 5.7%), the containing method (93.3 ± 5.7%) and the containing method (53.3 ± 5.7%), respectively. It was concluded from the study that the suitable methods of attachment for each soft coral were different and these methods are available for use in targeted propagation farms for restoration purposes.

The Red Sea has high biodiversity, with at least 266 coral and sponge species. The coral/Sponge holobiont is comprised of the coral/sponge animal and its associated microorganisms consisting of bacteria, archaea, fungi and viruses. It has been hypothesized that this interaction plays a role in coral/ sponge defense. This study aims to study the bio-diversity of some collected types of sponge and soft coral from Red Sea and to isolate associated bacteria from them. The result includes five types of sponges; Ircinia strobilina, Callyspongia viridis, Suberea spp., Spongia officinalis and Biemna ehrenbergi and five types of soft corals; Heteroxenia fuscescens, Didemnum moseleyi, Lobophytum pauciflorum, Sarcophyton trocheliophorum and Sinularia spp. Twenty two bacterial isolates were isolated from the sponges with 41 % and thirty two bacterial isolates were isolated from soft coral samples with 59 % collected from different Red Sea areas.

Surveys conducted in Eilat’s upper mesophotic coral ecosystem (MCE) revealed protruding columnar calcareous structures with a Sinularia octocoral colony growing atop of each. The current study addressed the hypothesis that these colonies produce spiculites, and sought to determine (a) the spatial occurrence and dimensions of the spiculite-forming colonies and their species affiliation; (b) their microstructural features; and (c) the elemental composition of the columnar spiculites in comparison to the sclerites of the colonies. All the spiculite-forming colonies were exclusively found in the upper MCEs and produced by S. vrijmoethi. This type of spiculite, including its elemental analysis, is reported here for the first time for coral reefs in general and for the MCE in particular. Examination of the spiculites by scanning electron microscopy and energy-dispersive X-ray spectroscopy revealed spindle shaped-sclerites cemented by crystallites. The elemental composition of the sclerites differed from that of the cementing crystallites, in featuring ~8% Mg in the former and none in the latter. Inductively coupled plasma mass spectrometry revealed fragments of spiculite to be composed of 35% sclerites and 65% crystallites. X-ray powder diffraction analysis of individual sclerites indicated that they are composed exclusively of magnesium-calcite, and the spiculite fragments to also feature 9.3 ± 4% aragonite and 5–7% amorphous calcium carbonate. Consequently, it is proposed that the formation of the crystallites, which lithify the sclerites, is caused by a non-biogenic aragonite precipitation, and that the living colony might benefit from this protruding spiculite structure by means of enhanced exposure to water flow.

A new 5α,8α-epidioxysterol, namely yalongsterol A (1), along with two known related steroids 5α,8α-epidioxy-24-methyl-cholesta-6,24(28)-dien-3β-ol (2) and (22E,24S)-5α,8α-epidioxy-24-methyl-cholesta-6,22-dien-3β-ol (3), were isolated from the South China Sea soft coral Sinularia sp. Their structures were established by extensive spectroscopic analyses and comparisons of the spectral data with those reported in the literature. In bioassay, compounds 1-3 showed moderate immunosuppressive activities against T and/or B lymphocyte cells with IC50 values ranging from 19.30 to 59.49 μM, and low cytotoxicity on murine splenocytes with CC50 values ranging from 40.88 to 62.29 μM.[Formula: see text].

Coral reefs support rich levels of biodiversity, but are globally threatened by a multitude of factors, including land-sourced pollutants. Concentrations of organochlorine pesticides (OCPs) in three species of coral reef invertebrate at five sites along the Maputaland coast, South Africa were quantified. We aimed to assess spatial and interspecies variations in pesticide accumulation. Markedly high levels of a range of OCP residues were detected within tissues, with total concentrations (ng g−1 ww) ranging from 460 to 1200 (Sarcophyton glaucum), 1100–3000 (Sinularia gravis) and 450–1500 (Theonella swinhoei), respectively. A decreasing gradient in total pesticide concentrations was detected southward from Regal Reef, opposite Lake Sibaya, the hypothesised source of the pollutants. Observed gradients in pesticide concentrations and nitrogen isotope signatures indicated coastal groundwater to be the likely source of the pollutants. Further studies are required to assess the potential ecotoxicological impacts of these contaminants at the organismal and ecosystem level.

The rapid development of lipidomics of human and higher animals stimulated the study of the lipidome of certain groups of marine organisms. Soft corals are an integral part of the tropical and cold-water ecosystems of the World Ocean, but there is almost no data on the lipidome of these animals. The total lipidome of a tropical soft coral Sinularia siaesensis (Cnidaria: Anthozoa: Octocorallia: Alcionacea) containing intracellular symbiotic microalgae (zooxanthellae) was studied by gas and liquid chromatography-mass spectrometry. The structure and content of 144 molecular species of the main classes of acyl lipids of this alcyonaria were determined, including waxes, triglycerides (TG), monoalkyldiacylglycerides (MADAG), ethanolamine, choline, serine, and inositol glycerophospholipids (PE, PC, PS, and PI), ceramide aminoethylphosphonate (CAEP), sulfoquinovosyldiacylglyceride (SQDG), and mono- and digalactosyldiacylglycerides (MGDG and DGDG). The main components of S. siaesensis lipids were waxes 16:0/16:0, 16:0/18:0, and 18:0/16:0; TG 16:0/16:0/16:0 and 16:2/16:0/16:0; MADAG 18:0e/16:0/16:0, 16:0e/16:0/18:0, and 16:0e/16:0/16:0; and PS 18:0e/24:5, lyso-PC 18:0e, PE 18:1e/20:4, PC 18:0e/20:4, CAEP 18:2b/16:0, SQDG 14:0/16:0, and PI 18:0/24:5. The dominance of saturated waxes in reserve lipids is a species-specific feature of tropical alcyonarians. Waxes are synthesized in the host organism, and zooxanthellae can increase the proportion of saturated waxes by transferring saturated fatty acids (FA). The residues of polyunsaturated FA (PUFA) are found in the molecules of TG and MADAG, mainly in the sn-1 and sn-2 positions, respectively. Detection of MADAG with residues of marker FA of zooxanthellae (18:0e/18:3/16:0, 18:0e/18:4/16:0, and 16:0e/18:3/16:0) confirms the transfer of PUFA from the symbionts to the host. Tetracosapolyenoic FA, which is a chemotaxonomic markers of octocorals, are concentrated in molecular species of PS and PI. Most molecular species of PE, PC, and PS are in alkylacyl form, while for PI molecules, a diacyl form is characteristic. A significant proportion of MGDG, DGDG, and SQDG points to the importance of zooxanthellae in the formation of the lipid profile of symbiotic soft corals. Determination of the profile of lipid molecular species requires the development of a lipidomic approach in the study of biochemistry and ecology of corals and other cnidarians.

Tropical corals cultured in or ex situ, are being increasingly shipped worldwide to supply wholesale aquarium companies and research institutions. Scleractinian corals are mostly traded for ornamental purposes, whereby octocorals are increasingly traded for biotechnological applications. During the shipping process corals can be affected by several stressors that in extreme cases can result in coral death. It is, therefore, important to understand the physiological effects of shipping on different coral species. For this, two octocoral species with biotechnological potential, Sinularia polydactyla and Sinularia asterolobata, were shipped from Indonesia to our research facilities in Europe, Portugal. Oxidative stress (catalase – CAT, glutathione S-transferase - GST, and total glutathione - tGSH), oxidative damage (lipid peroxidation - LPO), energy reserves (lipids, proteins, carbohydrates) and electron transport system (ETS) were measured at arrival and after three months of husbandry to evaluate stress and cellular damage after a common shipping practice. The CAT depletion, together with higher activity of the second line of oxidative defence (GST and tGSH) and energy consumption (measured as ETS activity), for S. polydactyla immediately after shipping, evidenced the detoxification effort to avoid cellular damage. However, colonies of this species did not recover from shipping and perished 24 h after arrival. S. asterolobata activated the antioxidative pathways (CAT, GST and tGSH) to control damage right after shipping. Nonetheless, after three months, levels of LPO were significantly higher. Post-stress regeneration and long-term acclimation to captivity conditions, are suggested explanations for these peroxidation values. This study highlights differences in species susceptibility to shipping stress and evidence the need to consider species-specific requirements to a successful shipping and reduce the loss of valuable biomass.

Abstract: Marine organisms are recognized as a rich source of bioactive secondary metabolites. The remarkable abundance and diversity of bioactive small molecules isolated from soft corals displayed their essential role in drug discovery for human diseases. Sterols and terpenes, particularly cembranolides, 14-membered cyclic diterpene, demonstrated numerous biological activities, such as antitumor, antimicrobial, antiviral, antidiabetic, anti-osteoporosis and anti-inflammatory. Accordingly, continuous investigation of marine soft corals leads the way to discover a plentiful number of chemical diverse natural products with various biological potentials for prospective pharmaceutical industrial applications. Such review affords plenary inspection of the total secondary metabolites isolated from the Sinularia, from 2008 until 2020, besides their natural sources as well as bioactivities whenever possible.

Coral polyps host intracellular symbiotic dinoflagellates (SD). The loss of SD (referred as bleaching) under stressful environmental conditions is the main reason of coral reef destruction, and therefore, intensively studied over the world. Lipids are the structural base of biomembranes and energy reserve of corals and are directly involved in the coral bleaching. In order to establish a relationship between coral tissue morphology, physiological processes and lipidome dynamics during bleaching, the soft coral Sinularia heterospiculata was exposed to experimental heat stress (33 °C) for 72 h. A chlorophyll content, structure of cells, the level of reactive oxygen species (ROS), and molecular species of storage and structural lipids were analyzed. After 24 h of heat exposure, the level of ROS-positive SD cells did not increase, but the host tissues lost a significant part of SD. The removal of SD cells by exocytosis were suggested. Exocytosis was presumed to prevail at earlier stages of the soft coral bleaching. Symbiophagosomes with degenerative SD were observed in the stressed coral host cells. After 24 h, the content of phosphatidylinositols, which involved in apoptosis and autophagy, was significantly decreased. The innate immune response was triggered, and SD were digested by the coral host. After 48 h, a degradation of SD chloroplasts and a decrease in the specific monogalactosyldiacylglycerol molecular species were detected that confirmed a disruption of lipid biosynthesis in chloroplasts. At the end of coral bleaching, the appearance of oxidized phosphatidylethanolamines, indicating damage to the host membranes, and the degradation of the coral tissues were simultaneously observed. Thus, a switch between dominant mechanisms of the SD loss during bleaching of S. heterospiculata was found and proved by certain variations of the lipidomic profile. Lipidomic parameters may become indicators of physiological processes occurring in the symbiotic coral organism and may be used for assessing anthropogenic or natural destructive effects on coral reefs.

Marine organism-based natural products derived from endophytic fungi (microorganisms that reside in internal tissues of organisms and produce secondary metabolites) have been proposed as ground-breaking due to their potential to supply novel compounds for drug discovery. This investigation into possible marine-based medical applications derived from isolated compounds entailed a process inclusive of initial antiproliferative assays, the cultivation of targeted strains, and the implementation of compound separation methods for sub-fractional study and UV absorption analysis. Fractional compound analysis was conducted using a High-Performance Liquid Chromatography (HPLC) UV detector to derive probable identifications of compounds that presented antiproliferative activity. Various strains decreased the growth of A2780S (ovarian cancer), and DU-145 (prostate cancer) cell lines to the 20% and 50% viability range, respectively, and showed a degree of activity against MCF-10A (breast cancer) cell lines. Forty-eight compounds fell into the UV absorption rate range of 195-384nm, with Benzene, Rac-BINAP, and L-Histidine being commonly identified. These compound identifications can be utilized for structural analysis, novel compound discovery, and the creation of an anticancer drug that reduces the probability of cancer resurfacing in the patient. Further investigations focusing on pharmacokinetics, the biological mechanisms behind genetically inherited cancers, and the effects of specific compounds against them, such as the potential to induce apoptosis or activate inhibitory mechanisms, need to be undertaken. This research will continue to acknowledge a crucial balance point of environmental utilization, and awareness for potential future uses in the medical field.

As coral populations decline worldwide in the face of ongoing environmental change, documenting their distribution, diversity and conservation status is now more imperative than ever. Accurate delimitation and identification of species is a critical first step. This task, however, is not trivial as morphological variation and slowly evolving molecular markers confound species identification. New approaches to species delimitation in corals are needed to overcome these challenges. Here, we test whether target enrichment of ultraconserved elements (UCEs) and exons can be used for delimiting species boundaries and population structure within species of corals by focusing on two octocoral genera, Alcyonium and Sinularia, as exemplary case studies. We designed an updated bait set (29,363 baits) to target-capture 3,040 UCE and exon loci, recovering a mean of 1,910 ± 168 SD per sample with a mean length of 1,055 ± 208 bp. Similar numbers of loci were recovered from Sinularia (1,946 ± 227 SD) and Alcyonium (1,863 ± 177 SD). Species-level phylogenies were highly supported for both genera. Clustering methods based on filtered SNPs delimited species and populations that are congruent with previous allozyme, DNA barcoding, reproductive and ecological data for Alcyonium, and offered further evidence of hybridization among species. For Sinularia, results were congruent with those obtained from a previous study using Restriction Site Associated DNA Sequencing. Both case studies demonstrate the utility of target-enrichment of UCEs and exons to address a wide range of evolutionary and taxonomic questions across deep to shallow time scales in corals.

Soft coral, Sinularia sp. had been proven to inherit promising anti-cancer properties against variety of cancer. Current study, Sinularia sp. extract was introduced to Hepatocellular carcinoma (Hep 3B). Cell viability assay indicated the extract exhibit a dose and time dependent cytotoxicity. LC50 exhibited the lowest at 72 h post treatment estimated as 45.3 µg/mL. Morphological alterations including nuclear condensation, cytoplasm shrinkage and deformed cellular shape in treated Hep 3B were observable. Chemometric analysis revealed hydrophobic metabolites were significantly altered. Elevated vitamin D and derivatives tend to up-regulation Ca2+ and ROS subsequently triggering apoptosis. Dysregulated glycerolipids may suggest that they were biotransformed to compensate the needs of phospholipids during cell damage. Perturbation of sphingolipids, ceramide and carbohydrate-conjugated ceramides species increased the release of pro-apoptotic components reside within mitochondria and promote programmed cell death in treated Hep 3B. To conclude, MS-based metabolomics enabled the characterization of Sinularia sp. extract-induced cell death.

Corals are ecosystem engineers of the coral reefs, one of the most biodiverse but severely threatened marine ecosystems. The ability of corals to form the three dimensional structure of reefs depends on the precipitation of calcium carbonate under biologically control. However, the exact mechanisms underlying this biologically controlled biomineralization remain to be fully unelucidated, for example whether corals employ a different molecular machinery for the deposition of different calcium carbonate (CaCO3) polymorphs (i.e., aragonite or calcite). Here we used tandem mass spectrometry (MS/MS) to compare skeletogenic proteins, i.e., the proteins occluded in the skeleton of three octocoral and one scleractinian species: Tubipora musica and Sinularia cf. cruciata, both forming calcite sclerites, the blue coral Heliopora coerulea with an aragonitic rigid skeleton, and the scleractinian aragonitic Montipora digitata. We observed extremely low overlap between aragonitic and calcitic species, while a core set of proteins is shared between octocorals producing calcite sclerites. However, the same carbonic anhydrase (CruCA4) is employed for the formation of skeletons of both polymorphs. Similarities could also be observed between octocorals and scleractinians, including the presence of a galaxin-like protein. Additionally, as in scleractinians, some octocoral skeletogenic proteins, such as acidic proteins and scleritin, appear to have been secondarily co-opted for calcification and likely derive from proteins playing different extracellular functions. In H. coerulea, co-option was characterized by aspartic acid-enrichment of proteins. This work represents the first attempt to identify the molecular basis underlying coral skeleton polymorph diversity, providing several new research targets and enabling both future functional and evolutionary studies aimed at elucidating the origin and evolution of biomineralization in corals.

Two new steroids, ximaosteroid E (1) and ximaosteroid F (2), along with two known related compounds (3 and 4), were isolated from the Chinese soft coral Sinularia sp. Notably, 1 possesses an uncommon dihydrofuran group. Their structures were established from extensive spectroscopic analyses and comparisons of their spectral data with those reported in the literature. The absolute configuration of 2 was determined by applying the modified Mosher’s method. In bioassay, compounds 1, 2, and 4 showed significant cytotoxicity against the HL-60 tumor cell line with IC50 values of 1.79, 4.03 and 0.69 μM, respectively.

Pulau Redang and Pulau Tioman have experienced huge tourism growth over the last two decades, but minimal sewage treatment may threaten the resilience of their coral reefs. This study uses stable isotope techniques to identify suitable bioindicators of sewage nutrients (δ15N) at these islands by measuring macroalgae (Lobophora spp.), gastropods (Drupella spp.), scleractinian coral (Acropora spp.), and leather coral (Sinularia spp.). At tourist hubs using seepage septic tank systems, enrichment of Acropora δ15N (Redang, +0.7‰) and Sinularia δ15N (Tioman, +0.4‰) compared to pristine background levels indicate enhanced sewage nutrient discharge. Carbon isotopes and survey data suggest that sedimentation did not confound these δ15N trends. Potential damaging effects of sewage discharge on the coral reef communities at both islands are highlighted by strong correlations between Acropora δ15N and regional variation in coral reef community structure, and exclusive occurrence of degraded reefs at regions of high sewage influence.

Soft corals of the genus Sinularia are widely distributed in the South China Sea. Two new lipid analogues (Z)-N-(3,4-dihydroxyphenethyl)-3-methyldo-dec-2-enamide (1) and (E)-1-(2,5-dihydroxy-4-methylphenyl)-6-acetoxy-2,3,7-trihydroxy-3,7,11,15-tetramethylhexadeca-11,14-dien (2), together with three known compounds (3–5) were isolated from the soft coral Sinularia flexibilis. Their structures were elucidated on the basis of extensive spectroscopic analysis, including one and two-dimensional NMR, MS, IR, UV, as well as by comparison with published data.

Soft corals have bioactive compounds to potential as marine natural products, but the over exploitive to destroy of that ecosystem. Therefor endophyte microbial isolation can be effort to prevent that matters. This research aimed to isolate and characteristic on the entophyte microbial of soft coral Lobophytum sp and Sinularia sp that collated from Maspari island waters. Methodology of research were establishing growth of microbial samples (bacterial and fungal), isolation and characterization. Total of bacteria colony of Lobophytum sp were obtained about 5 isolates, and Sinularia sp were about 4 isolates. The macroscopic characteristic showed that whole bacteria had white colors. That colonies had undulate, entire and curl (the edge of colony) and circular and irregular (for colony shape). For fungal of Lobophytum sp were obtained about 3 isolates, while Sinularia sp had only one isolate. The fungal colonies macroscopic characteristic showed yellow, green and white color, while shaped and edges colonies were thickened. spread, thin, round, dark, and the whole of isolates had filamentous hyphae.

Chemical examination of a cultured octocoral, Sinularia sandensis, led to the isolation of a new constituent, (24S)-24-methylcholest-5-en-3β,4α-diol (1), together with two unusual sterols, 3β,4α-dihydroxyergosta-5,24(28)-diene (2) and gorgosterol (3). The structures of compounds 1−3 were established utilizing spectroscopic analysis and literature comparison. Additionally, the structure of 3 was identified by a single-crystal X-ray diffraction analysis directly, for the first time. Sterols 1 and 3 demonstrated slightly inhibition effects for the expression of inducible nitric oxide synthase (iNOS) protein in lipopolysaccharides (LPS)-induced RAW 264.7 mouse macrophage cells.

Climate change threatens coral reefs, with recent heatwaves causing widespread coral bleaching and mortality. Soft corals (order Alcyonacea) provide reef structure and habitat, but most reef research has instead focused on reef-building hard corals (order Scleractinia). Reviewing the primary literature documenting the effects of recent (2014–2020) marine heatwaves on corals, a period including the third global coral bleaching event, we found that only 20% (19/94) of studies presented any results of heat stress effects on soft corals, and even fewer (5%) presented taxonomic-specific results, highlighting the need for further study. Using images (n = 6265) collected on 16 expeditions to the world's largest atoll (Kiritimati; central equatorial Pacific) between 2007 and 2019, we quantified soft coral cover around the atoll's shallow (10-12 m depth) forereefs before and after a prolonged heatwave (the 2015/2016 El Nino). Prior to the heatwave, soft coral accounted for 3.0% of the benthic community, with greater cover at more sheltered sites with lower net primary productivity; Lobophytum and Sinularia were the most common genera. We documented a complete loss of soft coral after the heatwave within our sites. New soft corals were detected in 2019, three years after the heatwave. Photos of individual colonies tracked over time revealed that soft coral structures can persist for several years post-mortality, and hard corals can recruit onto these structures. Our study exposes the vulnerability of soft corals to heat stress, which has received scant previous documentation. Future studies examining the effects of heatwaves on coral bleaching and mortality should include soft corals.

This study aims to assess the soft corals community around Mauritius and Rodrigues Island due to the limited research on the abundance and diversity of soft corals in the area. Seven soft corals species are newly reported from Mauritian waters. Triplicates of 5-metreline transect were used to survey soft corals at twelve different monitoring sites. Of the sites monitored for soft coral occurrence, the highest Margalef richness index and Shannon index (H’) values were obtained at Port Mathurin for Rodrigues Island and at Les Salines for Mauritius. Identification was carried out using both morphological characters and a DNA-based marker. The morphological identification process was based on the external form and colouration, type of colony growth; the type of polyps and colonies and sclerites analysis. 41 different species showed dissimilar characteristics, and results grouped the colonies to three different families; 32 colonies of Alcyoniidae, 3 of Nephtheidae and 6 of Xeniidae were obtained. To ascertain morphological classification, the longest non-coding region of the mitochondrial COI-COII intergenic spacer (IGS) (consisting of 122 nucleotides) was used to construct a molecular phylogeny that included 21 species of octocorals. The COI-COII IGS phylogeny recovered 5 well supported clades, which did not tally with the cladogram based on morphological characters. Three dendrograms based on morphological characters were constructed where the first one involved mapping of all the morphological characters onto the tree, the second one was based mainly on the type of sclerites present and the third one based on the collection depth of the samples. The dendrogram based on morphological markers clustered all the soft corals from the Alcyoniidae family aside from the other families. The second dendrogram clustered all the soft corals from the genus Sinularia, Lobophytum, Sarcophyton as well as Cladiella kashmani together, away from the soft corals with distinct sclerite form. Furthermore, the third dendrogram clustered the soft corals into 2 major clades, one clade clustering the soft corals which are ubiquitous and a larger clade including all soft corals collected from a depth of 0 m to above 20 m. As documented by other studies on octocorals, construction of the phylogenetic tree has led to an appreciation of the importance of genetic work which has been overlooked while using traditional morphological characters.

Chemical examination of the octocoral Sinularia humilis, collected in the waters of Taiwan, led to the isolation of S8 (1). Its structure was determined by a single-crystal x-ray diffraction analysis and this is the first time that S8 has been reported from a marine invertebrate.

Marine invertebrates have a great variety of defensive strategies, with taste deterrence and protective coloration among the most important. Species of the gastropod family Ovulidae are closely associated with chemically defended soft corals and can accumulate food-derived defensive substances. A painted mantle covers the shell, camouflaging some ovulid mollusks and making other conspicuous, which makes these mollusks a good model object for studying correlations between types of protective coloration and taste deterrence. We compared the palatability of two ovulids: Ovula ovum, whose coloration most researchers have interpreted as aposematic (although never tested directly), and Calpurnus verrucosus, whose coloration cannot be confidently assigned as either aposematic or cryptic. In feeding experiments, agar pellets flavored with water extracts of two mollusks and six soft coral species were offered to sympatric fishes, the Indo-Pacific sergeant (Abudefduf vaigiensis) and the juvenile barramundi ( Lates calcarifer ). Additionally, we studied fish feeding behavior. We found that both the foot and mantle of Ovula ovum have a strong aversive taste for fish, which proves aposematism in this species. On the contrary, Calpurnus verrucosus had an attractive taste for fish, which excludes aposematism in this mollusk. We contemplate possible crypticity over a long distance and in low visibility, as well as unlikeness of mimetic nature of such coloration. All soft corals tested, including host species for mollusks ( Sarcophyton and Sinularia) were strongly aversive. Because both mollusks feed on soft corals but differ dramatically in palatability, it is probable that Ovula ovum and Calpurnus verrucosus transform soft coral antifeedants in different ways; however, we cannot rule out the possibility of de novo synthesis of taste deterrents in Ovula ovum. Both fish species orosensorially tested flavored pellets several times before swallowing or rejecting them. For pellets that produce aversive taste, the number of repeated grasps is smaller and retention time is longer than for pellets that produce attractive taste.

An antifouling sesquiterpene isolated from Sinularia sp. was synthesized from citronellyl acetate in eight steps and 9% overall yield. The furan moiety was constructed using a multifunctional sulfone reagent.

Dynamics in reef cover, mortality and recruitment success of a high-latitude coral community in South Africa were studied over 20 yr with the aim to detect the effects of climate change. Coral communities at this locality are the southernmost on the African continent, non-accretive, attain high biodiversity and are dominated by soft corals. Long-term monitoring within fixed transects on representative reef was initiated in 1993 and has entailed annual photo-quadrat surveys and hourly temperature logging. Although sea temperatures rose by 0.15 °C p.a. at the site up to 2000, they have subsequently been decreasing, and the overall trend based on monthly means has been a significant decrease of 0.03 °C p.a. Despite this, minor bleaching was encountered in the region during the 1998 El Nino–Southern Oscillation event, again in the summer of 2000/2001 and in 2005. A significant decreasing trend of 0.95% p.a. in soft coral cover has been evident throughout the monitoring period, attributable to significant decreases in Sinularia and Lobophytum spp. cover. In contrast, hard coral cover gradually and significantly increased up to 2005, this being largely attributable to increases in cover by Acropora spp. Recruitment success and mortality of both soft and hard corals has displayed high inter-annual variability with increasing but non-significant trends in the last 5 yr. The reduction in soft coral cover has been more consistent and greater than that of hard corals, but it is difficult at this stage to attribute this to changes in water quality, acidification-linked accretion or temperature.

We report the first complete Stoloniferamitochondrial genome.Carijoa riisei(Duchassaing&Michelotti, 1860) isolate CLP2_A03was collected by scuba at 32 m on the USTS Texas Clipper (27° 53.7827' N, 93° 36.2702' W). The complete mitogenome has the ancestral octocoral gene order for its 14 protein-coding genes, two rRNA genes, and one tRNA gene. It is 18,714 bp (30.7% A, 15.8% C, 18.8% G, and 34.7% T). Of the Alcyonacea mitogenomes published to date, it is most genetically similar (94% uncorrected) to Sinularia ceramensisVerseveldt, 1977 (NC_044122).

Herein, we provide observation on the ecological relationships between the hydrozoan species Pteroclava krempfi and three alcyonacean genera: Lobophytum, Sarcophyton and Sinularia from protected and exposed reef habitats in the Maldives. The associations were found to be widespread in the investigated area with both an overall and taxon-specific symbiosis prevalence higher in the exposed reef sites. Pteroclava krempfi most frequently occurred with Lobophytum, followed by Sinularia and Sarcophyton. The prevalence of P. krempfi with soft corals was also positively correlated to percent host cover, which was higher in the outer reef sites, suggesting a host-reliant relationship for the hydrozoan. However, the nature of these relationships, as as well as the factors that drive their establishment, requires further investigation. The widespread degradation of coral reef ecosystems endangers the existence of many poorly understood, but intimate relationships that often go unrecognized.

Three new oxygenated steroids, sinulasterols A–C (1–3), along with seven known related steroids 4–10, were isolated from the Chinese soft coral Sinularia depressa. The structures of the new compounds were established from extensive spectroscopic data analyses and by comparison of their spectral data with those reported in the literature. Among the new compounds, metabolites 1 and 2 featured on unusual C-18 oxygenated pattern. In the TNF-α bioassay, compound 4 exhibited a potent inhibitory activity (IC50 = 12.1 μM), which was analogous to the positive control dexamethasone (IC50 = 8.7 μM), metabolites 1 and 2 displayed a moderate inhibitory activity (IC50 51.1 μM and 22.7 μM respectively).

Four new cembranoids (1–4) were isolated from the extracts of a soft coral collected from the sea area near Xisha Island, South China Sea. The structures of these compounds were determined mainly by spectroscopic analyses, with the absolute configuration of 1 being established by X-ray diffraction analysis. In bioassay, compounds 1 and 3 displayed moderate inhibitory activity against Aβ42 aggregation (20.6% and 37.2% inhibition at 10 μM). The binding mode of 1 with Aβ42 monomer was predicted by molecular docking. In addition, compounds 1 and 3 did not show cytotoxicity against human tumor cell lines (SH-SY5Y, MDA-MB-426, A549, Hep3B, and HT-29) at 100 μM. Taken together, these cembranoids as new anti-Aβ aggregation agents derived from Sinularia sp. provided a new chemical scaffold for anti-Alzhemer's disease drug discovery.

Three new compounds (9-11) were isolated together with eight known analogues from the fungus Pseudallescheria boydii associated with the South China Sea soft coral Sinularia sandensis. The structures of the new compounds were elucidated on the basis of the spectroscopic analysis, and the absolute configurations including the sulfur stereogenic center of a sulfoxide moiety were determined by comparison of experimental ECD spectra to TDDFT/ECD calculations. Epimeric chiral sulfoxides differing in the absolute configuration of the sulfur chirality center could be efficiently distinguished and assigned by comparing the experimental ECD to those of calculations for the sulfur epimers. In the in vitro biotests for osteoclastogenesis effects, compounds 1, 5, 7, and 10 exhibited a stimulatory activity, while compound 3 displayed an inhibitory activity.

One novel sesquiterpenoid containing an unprecedented eight-membered cyclic peroxide motif, sinulatumolin A (1), along with four new related terpenoids, namely sinulatumolins B–E (2–4 and 6), were isolated from South China Sea soft coral Sinularia tumulosa. The structures of all the isolates were elucidated by detailed spectroscopic analysis, chemical transformations, and single X-ray diffraction analysis. Compound 1 represents the first example of sesquiterpene bearing an eight-membered cyclic peroxide ring from soft coral. All the new compounds isolated were evaluated for their anti-inflammatory activity. Compounds 1, 3, 4 and 6 displayed significant TNF-α inhibitory activity being comparable with that of the positive control dexamethasone (IC50 = 8.7 μM), with IC50 values of 7.5, 2.6, 5.5, and 3.6 μM, respectively.