RESUMEN
Soluble epoxide hydrolase (sEH) is essential for converting epoxy fatty acids, such as epoxyeicosatrienoic acids (EETs), into their dihydroxy forms. EETs play a crucial role in regulating blood pressure, mediating anti-inflammatory responses, and modulating pain, making sEH a key target for therapeutic interventions. Current research is increasingly focused on identifying sEH inhibitors from natural sources, particularly marine environments, which are rich in bioactive compounds due to their unique metabolic adaptations. In this study, the sEH inhibitory activities of ten cembranoid diterpenes (1-10) isolated from the soft coral Sinularia maxima were evaluated. Among them, compounds 3 and 9 exhibited considerable sEH inhibition, with IC50 values of 70.68 µM and 78.83 µM, respectively. Enzyme kinetics analysis revealed that these two active compounds inhibit sEH through a non-competitive mode. Additionally, in silico approaches, including molecular docking and molecular dynamics simulations, confirmed their stability and interactions with sEH, highlighting their potential as natural therapeutic agents for managing cardiovascular and inflammatory diseases.
Asunto(s)
Antozoos , Diterpenos , Epóxido Hidrolasas , Simulación del Acoplamiento Molecular , Simulación de Dinámica Molecular , Epóxido Hidrolasas/antagonistas & inhibidores , Epóxido Hidrolasas/metabolismo , Antozoos/química , Animales , Diterpenos/farmacología , Diterpenos/química , Diterpenos/aislamiento & purificación , Cinética , Inhibidores Enzimáticos/farmacología , Inhibidores Enzimáticos/químicaRESUMEN
A high throughput screen performed to identify catalytic inhibitors of the oncogenic fusion form of cAMP-dependent protein kinase A catalytic subunit alpha (J-PKAcα) found an individual fraction from an organic extract of the marine soft coral Acrozoanthus australiae as active. Bioassay-guided isolation led to the identification of a 2-amino adenine alkaloid acroamine A (1), the first secondary metabolite discovered from this genus and previously reported as a synthetic product. As a naturally occurring protein kinase inhibitor, to unambiguously assign its chemical structure using modern spectroscopic and spectrometric techniques, five N-methylated derivatives acroamines A1-A5 (2-6) were semisynthesized. Three additional brominated congeners A6-A8 (7-9) were also semisynthesized to investigate the structure-activity relationship of the nine compounds as J-PKAcα inhibitors. Compounds 1-9 were tested for J-PKAcα and wild-type PKA inhibitory activities, which were observed exclusively in acroamine A (1) and its brominated analogs (7-9) achieving moderate potency (IC50 2-50 µM) while none of the N-methylated analogs exhibited kinase inhibition.
Asunto(s)
Alcaloides , Antozoos , Proteínas Quinasas Dependientes de AMP Cíclico , Animales , Antozoos/química , Estructura Molecular , Alcaloides/farmacología , Alcaloides/química , Alcaloides/aislamiento & purificación , Relación Estructura-Actividad , Proteínas Quinasas Dependientes de AMP Cíclico/antagonistas & inhibidores , Proteínas Quinasas Dependientes de AMP Cíclico/metabolismo , Adenina/farmacología , Adenina/análogos & derivados , Adenina/química , Inhibidores de Proteínas Quinasas/farmacología , Inhibidores de Proteínas Quinasas/química , Dominio CatalíticoRESUMEN
In osteoporosis, bone quality adversely affects the tissue structural competence which increases the risk of a complicated fracture healing. In the present study highly potent scaffold containing natural coral particles was designed and considered for the healing of critical size bone defect in osteoporosis rat model. Scaffold morphological evaluation confirmed the porous nanofibrous structure. Water uptake of about 900 % was obtained for the fabricated scaffold as the result of its composition and three-dimensional structure. Mechanical analysis revealed the compressive modulus of about 50 kPa for the fabricated coral-incorporated nanofibrous structure. In vitro cellular assessments revealed that the designed scaffold induces no toxicity and provides the proper substrate for cell attachment together with increased and prolonged cell proliferation. In vivo experiments demonstrated that implantation of the fabricated scaffold in the femoral defects of osteoporotic rats significantly increased the number of osteocytes and osteoblasts, and enhanced the BTV, and BMP-2 expression compared with the control group. Furthermore, it was observed that seeding the scaffolds with MSCs prior to implantation, resulted in substantial improvements in mRNA expression of the BMP-2 and VEGF genes and considerable enhancement in stereological findings such as significantly higher number of osteoblasts, osteocytes, TVB, and BTV.
Asunto(s)
Antozoos , Diferenciación Celular , Células Madre Mesenquimatosas , Osteoporosis , Andamios del Tejido , Animales , Femenino , Ratas , Antozoos/química , Proliferación Celular , Modelos Animales de Enfermedad , Células Madre Mesenquimatosas/metabolismo , Osteoblastos/metabolismo , Osteogénesis , Osteoporosis/patología , Osteoporosis/terapia , Poliésteres/química , Andamios del Tejido/químicaRESUMEN
Global Natural Products Social (GNPS) molecular networking platform was applied to discovery the undescribed compounds from the common marine fungi Aspergillus versicolor CGF9-1-2, ultimately resulting in isolation of four new polyketides, decumbenone E (1), decumbenone F (2), 2'-epi-8-O-methylnidurufin (6), (-)-phomoindene A (7), one new nucleoside, 3-methyl-9-(2-methylbutene)-xanthine (8), and five known analogues. Their structures were elucidated based on 1D/2D NMR spectroscopic and HRESIMS data analyses, meanwhile, the absolute configurations of new compounds were established based on the X-ray crystallographic experiments, as well as the electronic circular dichroism (ECD) analysis. All compounds were predicted pharmaceutical chemistry with ten commonly disease-related proteins by molecular docking. In addition, all compounds against TDP1 were performed in vitro, which was consistent with the docking result, and compound 6 shown a weak inhibitory activity.
Asunto(s)
Antozoos , Aspergillus , Simulación del Acoplamiento Molecular , Aspergillus/química , Antozoos/microbiología , Antozoos/química , Estructura Molecular , Animales , Policétidos/aislamiento & purificación , Policétidos/farmacología , Policétidos/química , China , Productos Biológicos/farmacología , Productos Biológicos/aislamiento & purificación , Productos Biológicos/química , Nucleósidos/aislamiento & purificación , Nucleósidos/química , Nucleósidos/farmacologíaRESUMEN
Coastal ecosystems, such as coral reefs, are particularly vulnerable to mercury contamination due to direct contact with terrestrial sources. Here, we evaluated, for the first time, the concentration of mercury in coral reefs in the Southwestern Atlantic using the amphi-atlantic scleractinian coral Montastraea cavernosa. Sampling was realized over an extension of 200 km along different coral reefs. Our data show mercury values ranging from 0.01 to 0.27 mg kg-1 in the tissue and 0.001-0.06 mg kg-1 in the skeleton and higher values when compared to coral worldwide. The concentration of mercury in the tissue from Todos os Santos Bay was higher than in open sea regions but also higher compared to other coral reefs of the world, while the skeleton concentration did not indicate any differences when compared to the open sea regions. The data presented is of concern as we consider the importance of coral reefs and should be used in future environmental management planning.
Asunto(s)
Antozoos , Arrecifes de Coral , Monitoreo del Ambiente , Mercurio , Contaminantes Químicos del Agua , Animales , Antozoos/química , Contaminantes Químicos del Agua/análisis , Mercurio/análisis , EcosistemaRESUMEN
Cembranolides are characteristic metabolites in marine soft corals, with complex structures and widespread biological activities. However, seldom has an intensive pharmacological study been done for these intriguing marine natural products. In this work, systematic chemical investigation was performed on Sinularia pedunculata by HSQC-based small molecule accurate recognition technology (SMART), resulting in the isolation and identification of 31 cembrane-type diterpenoids, including six new ones. In the bioassay, several compounds showed significant anti-inflammatory activities on the inhibition of NO production. The structure-activity relationship (SAR) was comprehensively analyzed, and two most bioactive and less toxic compounds 8 and 9 could inhibit inflammation through suppressing NF-κB and MAPK signaling pathways, and reduce the secretion of inflammatory cytokines. In a mouse model of dextran sodium sulfate (DSS)-induced acute colitis, 8 and 9 exhibited good anti-inflammatory effects and the ability to repair the colon epithelium, giving insight into the application of cembranolides as potential ulcerative colitis (UC) agents.
Asunto(s)
Antozoos , Colitis Ulcerosa , Sulfato de Dextran , Diterpenos , Animales , Colitis Ulcerosa/tratamiento farmacológico , Diterpenos/farmacología , Diterpenos/química , Diterpenos/uso terapéutico , Diterpenos/aislamiento & purificación , Ratones , Relación Estructura-Actividad , Antozoos/química , Antiinflamatorios/farmacología , Antiinflamatorios/química , Antiinflamatorios/uso terapéutico , Antiinflamatorios/aislamiento & purificación , Células RAW 264.7 , FN-kappa B/metabolismo , FN-kappa B/antagonistas & inhibidores , Descubrimiento de Drogas , Ratones Endogámicos C57BL , Humanos , Masculino , Óxido Nítrico/metabolismoRESUMEN
Marine natural products offer immense potential for drug development, but the limited supply of marine organisms poses a significant challenge. Establishing aquaculture presents a sustainable solution for this challenge by facilitating the mass production of active ingredients while reducing our reliance on wild populations and harm to local environments. To fully utilize aquaculture as a source of biologically active products, a cell-free system was established to target molecular components with protein-modulating activity, including topoisomerase II, HDAC, and tubulin polymerization, using extracts from aquaculture corals. Subsequent in vitro studies were performed, including MTT assays, flow cytometry, confocal microscopy, and Western blotting, along with in vivo xenograft models, to verify the efficacy of the active extracts and further elucidate their cytotoxic mechanisms. Regulatory proteins were clarified using NGS and gene modification techniques. Molecular docking and SwissADME assays were performed to evaluate the drug-likeness and pharmacokinetic and medicinal chemistry-related properties of the small molecules. The extract from Lobophytum crassum (LCE) demonstrated potent broad-spectrum activity, exhibiting significant inhibition of tubulin polymerization, and showed low IC50 values against prostate cancer cells. Flow cytometry and Western blotting assays revealed that LCE induced apoptosis, as evidenced by the increased expression of apoptotic protein-cleaved caspase-3 and the populations of early and late apoptotic cells. In the xenograft tumor experiments, LCE significantly suppressed tumor growth and reduced the tumor volume (PC3: 43.9%; Du145: 49.2%) and weight (PC3: 48.8%; Du145: 7.8%). Additionally, LCE inhibited prostate cancer cell migration, and invasion upregulated the epithelial marker E-cadherin and suppressed EMT-related proteins. Furthermore, LCE effectively attenuated TGF-ß-induced EMT in PC3 and Du145 cells. Bioactivity-guided fractionation and SwissADME validation confirmed that LCE's main component, 13-acetoxysarcocrassolide (13-AC), holds greater potential for the development of anticancer drugs.
Asunto(s)
Antozoos , Antineoplásicos , Apoptosis , Acuicultura , Productos Biológicos , Animales , Antozoos/química , Antineoplásicos/farmacología , Humanos , Productos Biológicos/farmacología , Productos Biológicos/química , Línea Celular Tumoral , Apoptosis/efectos de los fármacos , Ratones , Desarrollo de Medicamentos , Ensayos Antitumor por Modelo de Xenoinjerto , Simulación del Acoplamiento Molecular , Masculino , Tubulina (Proteína)/metabolismo , Ratones DesnudosRESUMEN
As the balance between erosional and constructive processes on coral reefs tilts in favor of framework loss under human-induced local and global change, many reef habitats worldwide degrade and flatten. The resultant generation of coral rubble and the beds they form can have lasting effects on reef communities and structural complexity, threatening the continuity of reef ecological functions and the services they provide. To comprehensively capture changing framework processes and predict their evolution in the context of climate change, heavily colonized rubble fragments were exposed to ocean acidification (OA) conditions for 55 days. Controlled diurnal pH oscillations were incorporated in the treatments to account for the known impact of diel carbonate chemistry fluctuations on calcification and dissolution response to OA. Scenarios included contemporary pH (8.05 ± 0.025 diel fluctuation), elevated OA (7.90 ± 0.025), and high OA (7.70 ± 0.025). We used a multifaceted approach, combining chemical flux analyses, mass alteration measurements, and computed tomography scanning images to measure total and chemical bioerosion, as well as chemically driven secondary calcification. Rates of net carbonate loss measured in the contemporary conditions (1.36 kg m-2 year-1) were high compared to literature and increased in OA scenarios (elevated: 1.84 kg m-2 year-1 and high: 1.59 kg m-2 year-1). The acceleration of these rates was driven by enhanced chemical dissolution and reduced secondary calcification. Further analysis revealed that the extent of these changes was contingent on the density of the coral skeleton, in which the micro- and macroborer communities reside. Findings indicated that increased mechanical bioerosion rates occurred in rubble with lower skeletal density, which is of note considering that corals form lower-density skeletons under OA. These direct and indirect effects of OA on chemical and mechanical framework-altering processes will influence the permanence of this crucial habitat, carrying implications for biodiversity and reef ecosystem function.
Asunto(s)
Antozoos , Cambio Climático , Arrecifes de Coral , Agua de Mar , Antozoos/fisiología , Antozoos/química , Animales , Agua de Mar/química , Concentración de Iones de Hidrógeno , Calcificación Fisiológica , Carbonatos/química , Carbonatos/análisis , Océanos y Mares , Acidificación de los OcéanosRESUMEN
An efficient synthetic strategy for scabrolide F (7), a norcembranolide diterpene that was isolated from the Taiwanese soft coral Sinularia scabra, has only recently been reported by our group. Herein, we report details of the first total synthesis of 7. The tetrahydrofuran domain of 7 was stereoselectively constructed via the 5-endo-tet cyclization of a hydroxy vinyl epoxide. The reaction of alkyl iodide 30 with dithiane 38, followed by the introduction of an alkene moiety, afforded allylation precursor 41. The coupling of alkyl iodide 42 and allylic stannane 43 was examined as a model experiment of allylation. Because the desired allylated product 44 was not obtained, an alternative synthetic route toward 7 was investigated instead. In the second synthetic approach, fragment-coupling between alkyl iodide 56 and aldehyde 58, macrolactonization, and transannular ring-closing metathesis were used as the key steps to achieve the first total synthesis of 7. We hope that this synthetic strategy provides access to the total synthesis of other macrocyclic norcembranolides. We also evaluated the antifouling activity and toxicity of 7 and its synthetic intermediates toward the cypris larvae of the barnacle Amphibalanus amphitrite. This study is the first to report the antifouling activity of norcembranolides as well as the biological activity of 7.
Asunto(s)
Diterpenos , Diterpenos/síntesis química , Diterpenos/química , Diterpenos/farmacología , Relación Estructura-Actividad , Animales , Incrustaciones Biológicas/prevención & control , Estereoisomerismo , Estructura Molecular , Antozoos/químicaRESUMEN
Five undescribed atranones, namely atranones V-Z (1-5), three undescribed dolabellane-type diterpenoids, namely stachatranones D-F (7-9), together with four known congeners (6 and 10-12), were obtained from a coral-associated strain of the toxigenic fungus Stachybotrys chartarum. Their structures were elucidated via extensive spectroscopic analyses, mainly including the HRESIMS and NMR data, single-crystal X-ray diffraction analysis, electronic circular dichroism calculation, and [Mo2(OAc)4] induced circular dichroism spectrum. The cardiomyocyte protective activity assay revealed that compound 9 significantly ameliorated cold ischemic injury at 24 h post cold ischemia (CI) in a dose-dependent manner. Moreover, compound 9 prevented CI induced dephosphorylation of phosphatidylinositol-3-kinase and RAC-α serine/threonine-protein kinase at 12 h post CI in a dose-dependent manner. In this work, the undescribed compound 9 could significantly protect cardiomyocytes against cold ischemic injury, highlighting the promising potential to be designed and developed as a novel cardioprotectant in heart transplant medicine.
Asunto(s)
Antozoos , Diterpenos , Miocitos Cardíacos , Stachybotrys , Animales , Stachybotrys/química , Antozoos/microbiología , Antozoos/química , Diterpenos/farmacología , Diterpenos/química , Diterpenos/aislamiento & purificación , Miocitos Cardíacos/efectos de los fármacos , Estructura Molecular , Relación Dosis-Respuesta a Droga , Frío , Ratas , Cardiotónicos/farmacología , Cardiotónicos/química , Cardiotónicos/aislamiento & purificación , Conformación Molecular , Fosfatidilinositol 3-Quinasas/metabolismoRESUMEN
Kallopterolides A-I (1-9), a family of nine diterpenoids possessing either a cleaved pseudopterane or a severed cembrane skeleton, along with several known compounds were isolated from the Caribbean Sea plume Antillogorgia kallos. The structures and relative configurations of 1-9 were characterized by analysis of HR-MS, IR, UV, and NMR spectroscopic data in addition to computational methods and side-by-side comparisons with published NMR data of related congeners. An investigation was conducted as to the potential of the kallopterolides as plausible in vitro anti-inflammatory, antiprotozoal, and antituberculosis agents.
Asunto(s)
Antozoos , Diterpenos , Diterpenos/química , Diterpenos/aislamiento & purificación , Diterpenos/farmacología , Animales , Antozoos/química , Antiprotozoarios/química , Antiprotozoarios/farmacología , Antiprotozoarios/aislamiento & purificación , Región del Caribe , Estructura Molecular , Antiinflamatorios/química , Antiinflamatorios/farmacología , Antiinflamatorios/aislamiento & purificación , Espectroscopía de Resonancia Magnética , Antituberculosos/química , Antituberculosos/farmacología , Antituberculosos/aislamiento & purificaciónRESUMEN
Geochemical proxies of sea surface temperature (SST) and seawater pH (pHsw) in scleractinian coral skeletons are valuable tools for reconstructing tropical climate variability. However, most coral skeletal SST and pHsw proxies are univariate methods that are limited in their capacity to circumvent non-climate-related variability. Here we present a novel multivariate method for reconstructing SST and pHsw from the geochemistry of coral skeletons. Our Scleractinian Multivariate Isotope and Trace Element (SMITE) method optimizes reconstruction skill by leveraging the covariance across an array of coral elemental and isotopic data with SST and pHsw. First, using a synthetic proxy experiment, we find that SMITE SST reconstruction statistics (correlation, accuracy, and precision) are insensitive to noise and variable calibration period lengths relative to Sr/Ca. While SMITE pHsw reconstruction statistics remain relative to δ11B throughout the same synthetic experiment, the magnitude of the long-term trend in pHsw is progressively lost under conditions of moderate-to-high analytical uncertainty. Next, we apply the SMITE method to an array of seven coral-based geochemical variables (B/Ca, δ11B, Li/Ca, Mg/Ca, Sr/Ca, U/Ca & Li/Mg) measured from two Bermudan Porites astreoides corals. Despite a <3.5 year calibration period, SMITE SST and pHsw estimates exhibit significantly better accuracy, precision, and correlation with their respective climate targets than the best single- and dual-proxy estimators. Furthermore, SMITE model parameters are highly reproducible between the two coral cores, indicating great potential for fossil applications (when preservation is high). The results shown here indicate that the SMITE method can outperform the most common coral-based SST and pHsw reconstructions methods to date, particularly in datasets with a large variety of geochemical variables. We therefore provide a list of recommendations and procedures for users to begin implementing the SMITE method as well as an open-source software package to facilitate dissemination of the SMITE method.
Asunto(s)
Antozoos , Agua de Mar , Temperatura , Agua de Mar/química , Concentración de Iones de Hidrógeno , Antozoos/química , Animales , Oligoelementos/análisisRESUMEN
Hepatitis B Virus (HBV) infection is a global public health challenge that seriously endangers human health. Soft coral, as a major source of terpenoids, contains many structurally novel and highly bioactive compounds. Sixteen cembranoids (1-16), including a new one named sinupedunol B (16), were isolated from the South China Sea Soft coral Sinularia pedunculata. The structure of the sinupedunol B (16) was determined through a combination of spectroscopic analysis and X-ray single-crystal diffraction. In this study, cembranoids isolated from Sinularia pedunculata were found of anti-HBV activity for the first time. Among them, flexilarin D (6) showed significant anti-HBV activity with an IC50 value of 5.57â µM without cytotoxicity. We then analyzed the structure-activity relationship (SAR). Furthermore, it is demonstrated that flexilarin D (6) can accelerate the formation of capsid, inhibit HBeAg, HBV core particle DNA, HBV total RNA and pregenomic RNA in a dose dependent manner. We also confirmed the anti-HBV activity of 6 in HepG2-NTCP infection system. Finally, we demonstrated the anti-HBV mechanism of these compounds by inhibiting the ENI/Xp enhancer/promoter.
Asunto(s)
Antozoos , Antivirales , Diterpenos , Virus de la Hepatitis B , Antozoos/química , Virus de la Hepatitis B/efectos de los fármacos , Antivirales/farmacología , Antivirales/química , Antivirales/aislamiento & purificación , Animales , Relación Estructura-Actividad , Diterpenos/farmacología , Diterpenos/química , Diterpenos/aislamiento & purificación , Humanos , China , Células Hep G2 , Relación Dosis-Respuesta a Droga , Conformación Molecular , Estructura Molecular , Pruebas de Sensibilidad Microbiana , Cristalografía por Rayos XRESUMEN
Octocoral of the genus Clavularia is a kind of marine invertebrate possessing abundant cytotoxic secondary metabolites, such as prostanoids and dolabellanes. In our continuous natural product study of C. spp., two previously undescribed prostanoids [clavulone I-15-one (1) and 12-O-deacetylclavulone I (2)] and eleven known analogs (3-13) were identified. The structures of these new compounds were elucidated based on analysis of their 1D and 2D NMR, HRESIMS, and IR data. Additionally, all tested prostanoids (1 and 3-13) showed potent cytotoxic activities against the human oral cancer cell line (Ca9-22). The major compound 3 showed cytotoxic activity against the Ca9-22 cells with the IC50 value of 2.11 ± 0.03 µg/mL, which echoes the cytotoxic effect of the coral extract. In addition, in silico tools were used to predict the possible effects of isolated compounds on human tumor cell lines and nitric oxide production, as well as the pharmacological potentials.
Asunto(s)
Antozoos , Antineoplásicos , Prostaglandinas , Humanos , Antozoos/química , Animales , Línea Celular Tumoral , Prostaglandinas/farmacología , Antineoplásicos/farmacología , Antineoplásicos/química , Antineoplásicos/aislamiento & purificación , Óxido Nítrico/metabolismo , Concentración 50 Inhibidora , Organismos Acuáticos , Estructura MolecularRESUMEN
Eleven undescribed cembrane-type diterpenoids, named litoamentenes A-K (1-11), were isolated from the soft coral Litophyton amentaceum collected from the South China Sea. Their structures were elucidated by extensive analysis of spectroscopic data, comparison with the literature data, single crystal X-ray diffraction, quantum chemical calculations and TDDFT-ECD calculations. This is the first systematic investigation of L. amentaceum. In particular, compounds 1-3 are cembrane-type norditerpenoids that lack isopropyl side chains. Compound 6 is a cembrane-type norditerpenoid without a methyl group at C-4, the first natural product identified with this carbon skeleton. Compounds 6, 9 and 10 showed modest cytotoxicity against several human cancer cell lines with IC50 values ranging from 3.99 to 14.56 µM.
Asunto(s)
Antozoos , Diterpenos , Ensayos de Selección de Medicamentos Antitumorales , Antozoos/química , Diterpenos/química , Diterpenos/farmacología , Diterpenos/aislamiento & purificación , Animales , Humanos , Estructura Molecular , Relación Estructura-Actividad , Antineoplásicos/farmacología , Antineoplásicos/química , Antineoplásicos/aislamiento & purificación , China , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Modelos MolecularesRESUMEN
A previously undescribed open-loop decarbonizing cembranolide, sarcocinerenolide A, and eight undescribed cembranolides, sarcocinerenolides B-I, characterized by poly-membered oxygen ring fragments were isolated from the soft coral Sarcophyton cinereum collected from the South China Sea. The structures and absolute configurations of these previously undescribed compounds were precisely determined by analysis of NMR data, DP4+ and ECD spectra. The bioactivities of the compounds were evaluated using zebrafish models and sarcocinerenolides C and H exhibited anti-thrombotic activity.
Asunto(s)
Antozoos , Diterpenos , Animales , Antozoos/química , Diterpenos/química , Diterpenos/farmacología , Diterpenos/aislamiento & purificación , Estructura Molecular , Pez Cebra , Fibrinolíticos/farmacología , Fibrinolíticos/química , Fibrinolíticos/aislamiento & purificación , China , Relación Estructura-ActividadRESUMEN
This study aimed to evaluate the concentration, distribution, along with the environmental and human health impact of eight heavy metals-Pb, Cr, Cu, Cd, Zn, Mn, Ni, and As-on St. Martin's Island in the northeastern Bay of Bengal, and in doing so to help implement new legislations to protect the island. Focusing on the island's significance as a tourist destination, with seafood being a prominent dietary component, three sample types (sediment, seawater, and crustaceans) were selected for a comprehensive assessment, considering seasonal variations. Concentration of metals was observed to be lower than the established standards in sediment samples, but in seawater samples, Pb, Cr, Cd and Zn were higher than US-EPA values for natural marine water. The metals displayed a decreasing trend of Zn > Ni > Pb > Cu > Mn > As > Cd > Cr in crustacean samples for both seasons. Crustacean samples displayed higher metal concentrations in winter than in monsoon. Pb exceeded the maximum allowable limit for crustaceans with a concentration of about 3 and 4 mg kg-1 in monsoon and winter respectively; being more than 6-8 times the standard for Bangladesh which is only about 0.5 mg kg-1. Health indices displayed that although adults may suffer less from carcinogenic/non-carcinogenic health effects, the risks are far greater for children. For both age groups, As and Ni displayed possibilities of developing cancer. Principal Component Analysis (PCA)shed light on the sources of metals and showed that most of them were from anthropogenic sources. Overall, this study found that the quality of the environment of the island was better in comparison to previous studies made before the pandemic, and so, if the trend continues, it may lead to a better environment for the organisms around the island and help to keep the negative physiological impacts from the consumption of these organisms to a minimal.
Asunto(s)
Bahías , Monitoreo del Ambiente , Islas , Metales Pesados , Contaminantes Químicos del Agua , Contaminantes Químicos del Agua/análisis , Metales Pesados/análisis , Animales , Humanos , Bahías/química , Agua de Mar/química , Sedimentos Geológicos/química , Antozoos/química , India , Estaciones del Año , Metales/análisis , Alimentos Marinos/análisis , CrustáceosRESUMEN
Extracellular chemical cues constitute much of the language of life among marine organisms, from microbes to mammals. Changes in this chemical pool serve as invisible signals of overall ecosystem health and disruption to this finely tuned equilibrium. In coral reefs, the scope and magnitude of the chemicals involved in maintaining reef equilibria are largely unknown. Processes involving small, polar molecules, which form the majority components of labile dissolved organic carbon, are often poorly captured using traditional techniques. We employed chemical derivatization with mass spectrometry-based targeted exometabolomics to quantify polar dissolved phase metabolites on five coral reefs in the U.S. Virgin Islands. We quantified 45 polar exometabolites, demonstrated their spatial variability, and contextualized these findings in terms of geographic and benthic cover differences. By comparing our results to previously published coral reef exometabolomes, we show the novel quantification of 23 metabolites, including central carbon metabolism compounds (e.g., glutamate) and novel metabolites such as homoserine betaine. We highlight the immense potential of chemical derivatization-based exometabolomics for quantifying labile chemical cues on coral reefs and measuring molecular level responses to environmental stressors. Overall, improving our understanding of the composition and dynamics of reef exometabolites is vital for effective ecosystem monitoring and management strategies.
Asunto(s)
Arrecifes de Coral , Metabolómica , Animales , Metabolómica/métodos , Metaboloma , Islas Virgenes de los Estados Unidos , Antozoos/metabolismo , Antozoos/química , Espectrometría de Masas/métodos , Ecosistema , Carbono/metabolismo , Carbono/químicaRESUMEN
The black corals possess a branched, tree-like skeleton that is composed of chitin fibrils embedded within a protein matrix. This skeleton exhibits growth rings interlocked by spines. The lamellae are tightly wrapped around the spines, creating a structure akin to an onion. The indentation hardness and Young's modulus of the spines are comparable to those of the chitin rings. The compressive stress and the fracture toughness are increased by approximately 14.6% and 32.2% at higher loading rate in the dry state, but remain comparable at different loading rates in the wet state. The lamellar interfaces have a tendency to resist sliding in the dry state. As a result, the lamellae that curve around the spines are prone to fracturing one by one, just like an onion being peeled. This allows the material to absorb more fracture energy, ensuring that the spines can effectively resist the lamellar delamination.
Asunto(s)
Antozoos , Antozoos/química , Animales , Módulo de Elasticidad , Quitina/química , DurezaRESUMEN
Four undescribed sesquiterpenoids, lemneolemnanes A-D (1-4), have been isolated from the marine soft coral Lemnalia sp. The absolute configurations of the stereogenic carbons of 1-4 were determined by single-crystal X-ray crystallographic analysis. Compounds 1 and 2 are epimers at C-3 and have an unusual skeleton with a formyl group on C-6. Compound 3 possesses an uncommonly rearranged carbon skeleton, while 4 has a 6/5/5 tricyclic system. Compound 1 showed significant anti-Alzheimer's disease (AD) activity in a humanized Caenorhabditis elegans AD pathological model.