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Due to the adverse environmental impacts of toxic heavy metal-based antifoulants, the screening of environmentally friendly antifoulants has become important for the development of marine antifouling technology. Compared with the traditional lengthy and costly screening method, computer-aided drug design (CADD) offers a promising and efficient solution that can accelerate the screening process of green antifoulants. In this study, we selected barnacle chitin synthase (CHS, an important enzyme for barnacle settlement and development) as the target protein for docking screening. Three CHS genes were identified in the barnacle Amphibalanus amphitrite, and their encoded proteins were found to share a conserved glycosyltransferase domain. Molecular docking of 31,561 marine natural products with AaCHSs revealed that zoanthamine alkaloids had the best binding affinity (-11.8 to -12.6â¯kcal/mol) to AaCHSs. Considering that the low abundance of zoanthamine alkaloids in marine organisms would limit their application as antifoulants, a marine fungal-derived natural product, mycoepoxydiene (MED), which has a similar chemical structure to zoanthamine alkaloids and the potential for large-scale production by fermentation, was selected and validated for stable binding to AaCHS2L2 using molecular docking and molecular dynamics simulations. Finally, the efficacy of MED in inhibiting cyprid settlement of A. amphitrite was confirmed by a bioassay that demonstrated an EC50 of 1.97⯵g/mL, suggesting its potential as an antifoulant candidate. Our research confirmed the reliability of using AaCHSs as antifouling targets and has provided insights for the efficient discovery of green antifoulants by CADD.
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Alcaloides , Incrustaciones Biológicas , Thoracica , Animales , Quitina Sintasa/genética , Quitina Sintasa/metabolismo , Simulación del Acoplamiento Molecular , Reproducibilidad de los Resultados , Incrustaciones Biológicas/prevención & control , Alcaloides/farmacología , LarvaRESUMEN
Marine natural products are promising sources of green antifoulants. Here, a new compound (1) was isolated from the soft coral Sinularia flexibilis. This compound, another nine cembranoids (2-10) from S. flexibilis, and three eunicellin-type diterpenoids (11-13) from the gorgonian Muricella sp. were tested for antifouling activity against larval settlement of the bryozoan Bugula neritina. Compounds 2, 3, 4, 9, 12, and 13 exhibited significant antifouling activity, with EC50 values of 18.2, 99.7, 67.9, 35.6, 33.9, and 49.3 µM, respectively. Analysis of the structure-activity relationships suggested that the hydroxy group at C-13 in compound 4 reduced its antifouling activity.
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Antozoos , Incrustaciones Biológicas , Briozoos , Animales , Terpenos , Incrustaciones Biológicas/prevención & control , Relación Estructura-ActividadRESUMEN
Many marine invertebrates have planktonic larval and benthic juvenile/adult stages. When the planktonic larvae are fully developed, they must find a favorable site to settle and metamorphose into benthic juveniles. This transition from a planktonic to a benthic mode of life is a complex behavioral process involving substrate searching and exploration. Although the mechanosensitive receptor in the tactile sensor has been implicated in sensing and responding to surfaces of the substrates, few have been unambiguously identified. Recently, we identified that the mechanosensitive transient receptor potential melastatin-subfamily member 7 (TRPM7) channel, highly expressed in the larval foot of the mussel Mytilospsis sallei, was involved in substrate exploration for settlement. Here, we show that the TRPM7-mediated Ca2+ signal was involved in triggering the larval settlement of M. sallei through the calmodulin-dependent protein kinase kinase ß/AMP-activated protein kinase/silk gland factor 1 (CaMKKß-AMPK-SGF1) pathway. It was found that M. sallei larvae preferred the stiff surfaces for settlement, on which TRPM7, CaMKKß, AMPK, and SGF1 were highly expressed. These findings will help us to better understand the molecular mechanisms of larval settlement in marine invertebrates, and will provide insights into the potential targets for developing environmentally friendly antifouling coatings for fouling organisms.
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Bivalvos , Canales Catiónicos TRPM , Animales , Proteínas Quinasas Activadas por AMP/metabolismo , Organismos Acuáticos/metabolismo , Bivalvos/fisiología , Quinasa de la Proteína Quinasa Dependiente de Calcio-Calmodulina/metabolismo , Larva/metabolismo , Fosforilación , Canales Catiónicos TRPM/metabolismo , Calcio/metabolismo , Transducción de SeñalRESUMEN
Conducting polymer nanocoatings render plastics to possess interesting optical, chemical, and electrical properties. It nevertheless remains technically challenging to deposit uniform conducting polymer nanocoatings on ambient plastic substrates ascribed to the inert and varied chemical properties of plastics and the notorious processability of conducting polymers. Previous studies have made progress in delivering various conducting polymer thin films via oxidative chemical vapor deposition. Herein, we develop a solution-based approach to polyaniline (PANI) and PEGylated PANI nanocoatings on multiple engineering plastics followed by evaluating their antifouling performance. The procedure relies on the formation of uniform, lyotropic V2O5·nH2O thin films on plastics assisted by a surfactant-sodium N-lauroylsarcosinate. Next, in situ, oxidative polymerization causes the formation of nanofibrous PANI nanocoatings. Finally, interfacial functionalization leads to PEGylated PANI nanocoatings, and the steric nanolayer effectively repels the adsorption of bovine serum albumin and the attachment of the bacterium Pseudoalteromonas sp. on the surface. It is worth noting that the antifouling properties rely mainly on the presence of PEGylated PANI nanocoatings, irrespective of the type of plastic substrates underneath. The current study therefore opens an avenue for the solution-based delivery of conducting polymer-based, functional nanocoatings on hydrophobic substrates in a controllable manner with the availability of further modification.
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Hydrogels can be used as an alternative coating material for ships against marine biofouling. However, the adhesion of wet and soft hydrogels onto solid metals remains a challenging problem. Here we report the adhesion of a typical hydrogel material, poly(vinyl alcohol) (PVA)-glycerol hydrogel, onto stainless steel substrates and the antifouling potency of the adhered PVA-glycerol hydrogels. Poly(allylamine hydrochloride) (PAH) hydrogel and ethyl α-cyanoacrylate (ECA) are used as the binders, and they are found to be able to firmly bond the PVA-glycerol hydrogels onto the stainless steel substrates. The PAH hydrogel does not affect the mechanical properties of the PVA-glycerol hydrogel during use, but it tends to lose the adhesive ability in a dehydrating environment. In contrast, the ECA adhesive can maintain strong bonding between PVA-glycerol hydrogels and substrates upon several water losing/water absorbing cycles, despite some negative effects on the strength of the PVA-glycerol hydrogel. Biological experiments show that the PVA-glycerol hydrogel has a strong settlement-inhibiting effect on the barnacle Balanus albicostatus, suggesting that combining the PVA-glycerol hydrogel with ECA adhesive may have promising applications in marine antifouling.
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Marine bacterial biofilms have long been recognized as potential inducers of larval settlement and metamorphosis in marine invertebrates, but few chemical cues from bacteria have been identified. Here, we show that larval settlement and metamorphosis of an invasive fouling mussel, Mytilopsis sallei, could be induced by biofilms of bacteria isolated from its adult shells and other substrates from the natural environment. One of the strains isolated, Vibrio owensii MS-9, showed strong inducing activity which was attributed to the release of a mixture of nucleobases including uracil, thymine, xanthine, hypoxanthine, and guanine into seawater. In particular, the synergistic effect of hypoxanthine and guanine was sufficient for the inducing activity of V. owensii MS-9. The presence of two or three other nucleobases could enhance, to some extent, the activity of the mixture of hypoxanthine and guanine. Furthermore, we determined that bacteria producing higher concentrations of nucleobases were more likely to induce larval settlement and metamorphosis of M. sallei than were bacteria producing lower concentrations of nucleobases. The present study demonstrates that bacterial nucleobases play an important role in larval settlement and metamorphosis of marine invertebrates. This provides new insights into our understanding of the role of environmental bacteria in the colonization and aggregation of invasive fouling organisms and of the metabolites used as chemical mediators in cross-kingdom communication within aquatic systems.IMPORTANCE Invasive species are an increasingly serious problem globally. In aquatic ecosystems, invasive dreissenid mussels are well-known ecological and economic pests because they appear to effortlessly invade new environments and foul submerged structures with high-density aggregations. To efficiently control exotic mussel recruitment and colonization, the need to investigate the mechanisms of substrate selection for larval settlement and metamorphosis is apparent. Our work is one of very few to experimentally demonstrate that compounds produced by environmental bacteria play an important role in larval settlement and metamorphosis in marine invertebrates. Additionally, this study demonstrates that bacterial nucleobases can be used as chemical mediators in cross-kingdom communication within aquatic systems, which will enhance our understanding of how microbes induce larval settlement and metamorphosis of dreissenid mussels, and it furthermore may allow the development of new methods for application in antifouling.
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Bivalvos/microbiología , Larva/crecimiento & desarrollo , Vibrio/metabolismo , Animales , Bivalvos/crecimiento & desarrollo , Guanina/análisis , Guanina/metabolismo , Metamorfosis Biológica , Agua de Mar/análisis , Timina/análisis , Timina/metabolismo , Uracilo/análisis , Uracilo/metabolismo , Vibrio/aislamiento & purificación , Xantina/análisis , Xantina/metabolismoRESUMEN
Six new diphenyl ethers (1â»6) along with eleven known analogs were isolated from the ethyl acetate extract of a marine-derived Aspergillus sydowii guided by LC-UV-MS. Their structures were unambiguously characterized by HRESIMS, NMR, as well as chemical derivatization. Compounds 1 and 2 are rare diphenyl ether glycosides containing d-ribose. The absolute configuration of the sugar moieties in compounds 1â»3 was determined by a LC-MS method. All the compounds were evaluated for their cytotoxicities against eight cancer cell lines, including 4T1, U937, PC3, HL-60, HT-29, A549, NCI-H460, and K562, and compounds 1, 5, 6, and 8â»11 were found to exhibit selective cytotoxicity against different cancer cell lines.
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Antineoplásicos/farmacología , Organismos Acuáticos/química , Aspergillus/química , Éteres Fenílicos/farmacología , Antineoplásicos/química , Antineoplásicos/aislamiento & purificación , Línea Celular Tumoral , Ensayos de Selección de Medicamentos Antitumorales , Humanos , Espectroscopía de Resonancia Magnética , Estructura Molecular , Éteres Fenílicos/química , Éteres Fenílicos/aislamiento & purificación , Espectrometría de Masa por Ionización de ElectrosprayRESUMEN
The effects of ocean acidification (OA) and warming on the physiological processes of many marine species have been well documented. However, far less is known about the impacts of these global variables on chemical communication. In this study, we identified the barnacle waterborne settlement pheromone (BWSP) of Balanus albicostatus as adenosine (Ado). Our results showed that neither elevated temperature (30 °C vs. ambient 26 °C) nor elevated pCO2 (1000 µatm vs. ambient 400 µatm) significantly affected the release of Ado from B. albicostatus adults. Exposure to elevated temperature and OA did not impair larval cue perception for settlement in B. albicostatus; however, OA inhibited settlement under elevated temperature in the absence/presence of BWSP, and elevated temperature induced larval settlement only in the presence of BWSP under ambient pCO2 condition. These results provided important insights into barnacle aggregation behavior in changing oceans and may help to predict the consequences of climate change on barnacle populations.
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Agua de Mar , Thoracica , Animales , Feromonas , Concentración de Iones de Hidrógeno , Adenosina , Acidificación de los Océanos , Océanos y Mares , Dióxido de CarbonoRESUMEN
Research on the microbiota associated with marine invertebrates is important for understanding host physiology and the relationship between the host and the environment. In this study, the microbiota of the green mussel Perna viridis was characterized at the tissue scale using 16S rRNA gene high-throughput sequencing and compared with the microbiota of the surrounding environment. Different mussel tissues were sampled, along with two environmental samples (the mussel's attachment substratum and seawater). The results showed that the phyla Proteobacteria, Bacteroidetes, and Spirochaetae were dominant in mussel tissues. The bacterial community composition at the family level varied among the tissues of P. viridis. Although the microbiota of P. viridis clearly differed from that of the surrounding seawater, the composition and diversity of the microbial community of the foot and outer shell surface were similar to those of the substratum, indicating their close relationship with the substratum. KEGG prediction analysis indicated that the bacteria harbored by P. viridis were enriched in the degradation of aromatic compounds, osmoregulation, and carbohydrate oxidation and fermentation, processes that may be important in P. viridis physiology. Our study provides new insights into the tissue-scale characteristics of mussel microbiomes and the intricate connection between mussels and their environment.
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Barnacles are the only sessile lineages among crustaceans, and their sessile life begins with the settlement of swimming larvae (cyprids) and the formation of protective shells. These processes are crucial for adaptation to a sessile lifestyle, but the underlying molecular mechanisms remain poorly understood. While investigating these mechanisms in the acorn barnacle, Amphibalanus amphitrite, we discovered a new gene, bcs-6, which is involved in the energy metabolism of cyprid settlement and originated from a transposon by acquiring the promoter and cis-regulatory element. Unlike mollusks, the barnacle shell comprises alternate layers of chitin and calcite and requires another new gene, bsf, which generates silk-like fibers that efficiently bind chitin and aggregate calcite in the aquatic environment. Our findings highlight the importance of exploring new genes in unique adaptative scenarios, and the results will provide important insights into gene origin and material development.
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Thoracica , Animales , Thoracica/genética , Adaptación Fisiológica/genética , Larva/genética , Quitina/metabolismo , Filogenia , Carbonato de Calcio , Elementos Transponibles de ADN/genética , Metabolismo Energético/genética , Evolución MolecularRESUMEN
In the search for new environmental friendly antifouling (AF) agents, four coumarins were isolated from the herbal plant Cnidium monnieri, known as osthole (1), imperatorin (2), isopimpinellin (3) and auraptenol (4). Furthermore, five coumarin derivatives, namely 8-epoxypentylcoumarin (5), meranzin hydrate (6), 2'-deoxymetranzin hydrate (7), 8-methylbutenalcoumarin (8), and micromarin-F (9) were synthesized from osthole. Compounds 1, 2, 4, 7 showed high inhibitory activities against larval settlement of Balanus albicostatus with EC(50) values of 4.64, 3.39, 3.38, 4.67 µg mL-1. Compound 8 could significantly inhibit larval settlement of Bugula neritina with an EC(50) value of 3.87 µg mL-1. The impact of functional groups on anti-larval settlement activities suggested that the groups on C-5' and C-2'/C-3' of isoamylene chian could affect the AF activities.
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Briozoos/efectos de los fármacos , Cnidium/química , Cumarinas/farmacología , Thoracica/efectos de los fármacos , Animales , Briozoos/crecimiento & desarrollo , Cumarinas/síntesis química , Cumarinas/química , Relación Dosis-Respuesta a Droga , Furocumarinas/química , Furocumarinas/farmacología , Larva/efectos de los fármacos , Larva/crecimiento & desarrollo , Dosificación Letal Mediana , Modelos Químicos , Estructura Molecular , Extractos Vegetales/química , Extractos Vegetales/farmacología , Thoracica/crecimiento & desarrolloRESUMEN
Biofouling and corrosion of underwater equipment induced by marine organisms have become major issues in the marine industry. The superior corrosion resistance of Fe-based amorphous coatings makes them suitable for marine applications; however, they have a poor antifouling ability. In this work, a hydrogel-anchored amorphous (HAM) coating with satisfactory antifouling and anticorrosion performance is designed, utilizing an interfacial engineering strategy involving micropatterning, surface hydroxylation, and a dopamine intermediate layer to increase the adhesion strength between the hydrogel layer and the amorphous coating. The as-obtained HAM coating exhibits exceptional antifouling properties, achieving 99.8% resistance to algae, 100% resistance to mussels, and excellent biocorrosion resistance against Pseudomonas aeruginosa. Antifouling and anticorrosion performance of the HAM coating was also explored by conducting a marine field test in the East China Sea, and no signs of corrosion and fouling are observed after 1 month of immersion. It is revealed that the outstanding antifouling properties stem from the killing-resisting-camouflaging trinity that resists organism attachment across different length scales, and the excellent anticorrosion performance originates from the remarkable barrier of the amorphous coating against Cl- ion diffusion and microbe-induced biocorrosion. This work presents a novel methodology for designing marine protective coating with excellent antifouling and anticorrosion properties.
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The microbiologically influenced corrosion of 304 stainless steel in the presence of a marine biofilm-forming bacterium Tenacibaculum mesophilum D-6 was systematically investigated by means of electrochemical techniques and surface analyses to reveal the effect of the selective attachment and adsorption of the biofilms on the passivity breakdown of the stainless steel. It was found that the T. mesophilum D-6 was electroactive and could oxidize low valent cations and metal, facilitating the local dissolution of the passive film and the substrate in the film defects, nearly doubling the surface roughness. The biofilms of T. mesophilum D-6 with mucopolysaccharide secreta and chloride ions tended to preferentially adsorb at the defects of the passive film on the steel, yielding non-homogeneous microbial aggregates and local Cl- enrichment there. The adsorption of the bacteria and chloride ions reduced the thickness of passive film by 23.9%, and generate more active sites for pitting corrosion on the passive film and more semiconducting carrier acceptors in the film. The maximum current density of the 304 SS in the presence of T. mesophilum D-6 was over one order of magnitude higher than that in the sterile medium, and the largest pit was deepened 3 times.
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Acero Inoxidable , Tenacibaculum , Biopelículas , Corrosión , Propiedades de SuperficieRESUMEN
Surface topography has been demonstrated as an effective nonchemical strategy for controlling the fouling resistance of a surface, but its impact on optical transparency remains a barrier to the application of this strategy in optical materials. To reconcile the conflicting effects of surface topography on optical transparency and fouling resistance, here we study the optical properties and antifouling performance of nanowrinkled surfaces inspired by the corneal surface of zebrafish (Danio rerio). Experimental and numerical analyses demonstrate that a good compromise between optical transparency and antifouling efficacy can be achieved by wavy nanowrinkles with a characteristic wavelength of 800 nm and an amplitude of 100 nm. In particular, the optimal wrinkled surface under study can reduce biofouling by up to 96% in a single-species (Pseudoalteromonas sp.) bacterial settlement assay in the laboratory and 89% in a field test while keeping the total transmittance above 0.98 and haze below 0.04 underwater. Moreover, our nanowrinkled surface also exhibits excellent resistance against contamination by inorganic particles. This work provides a nonchemical strategy for achieving the coexistence of optical transparency and fouling resistance on one single material, which implies significant application potential in various optical devices and systems, such as antibacterial contact lenses and self-cleaning solar panels.
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Incrustaciones Biológicas , Pseudoalteromonas , Animales , Antibacterianos/farmacología , Incrustaciones Biológicas/prevención & control , Córnea , Propiedades de Superficie , Pez CebraRESUMEN
Given the adverse environmental impacts of the antifoulants currently used in marine antifouling paints, such as copper and booster biocides, it is urgent to identify potential substitutes that are environmentally benign. Here, we examined the degradation of camptothecin (a natural product previously identified as an efficient antifoulant in the laboratory and in the field) under various conditions and evaluated the environmental risks associated with its use as a marine antifoulant. We found that camptothecin was rapidly photolyzed in seawater: the half-life of camptothecin was less than 1 d under a light intensity of 1000-20,000 lx and was approximately 0.17 d under sunlight irradiation. At pH 4 and pH 7, camptothecin had half-lives of 30.13 and 16.90 d, respectively; at 4 °C, 25 °C, and 35 °C, the half-lives of camptothecin were 23.90, 21.66, and 26.65 d, respectively. Camptothecin biodegradation in seawater was negligible. The predicted no-effect concentration (PNEC) of camptothecin was 2.19 × 10-1 µg L-1, while the average predicted environmental concentrations (PECs) in open seas, shipping lanes, commercial harbors, and marinas were 6.14 × 10-7, 9.39 × 10-7, 6.80 × 10-3, and 5.03 × 10-2 µg L-1, respectively. The PEC/PNEC ratio of camptothecin was much lower than 1 (i.e., 2.80 × 10-6, 4.29 × 10-6, 3.11 × 10-2, and 2.30 × 10-1 for open seas, shipping lanes, commercial harbors, and marinas, respectively), indicating that the use of camptothecin as a marine antifoulant posed little environmental risk.
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Contaminantes Químicos del Agua , Camptotecina , Pintura , Agua de Mar , Navíos , Contaminantes Químicos del Agua/análisisRESUMEN
Insulin analogs have been developed to treat diabetes with focus primarily on improving the time action profile without affecting ligand-receptor interaction or functional selectivity. As a result, inherent liabilities (e.g. hypoglycemia) of injectable insulin continue to limit the true therapeutic potential of related agents. Insulin dimers were synthesized to investigate whether partial agonism of the insulin receptor (IR) tyrosine kinase is achievable, and to explore the potential for tissue-selective systemic insulin pharmacology. The insulin dimers induced distinct IR conformational changes compared to native monomeric insulin and substrate phosphorylation assays demonstrated partial agonism. Structurally distinct dimers with differences in conjugation sites and linkers were prepared to deliver desirable IR partial agonist (IRPA). Systemic infusions of a B29-B29 dimer in vivo revealed sharp differences compared to native insulin. Suppression of hepatic glucose production and lipolysis were like that attained with regular insulin, albeit with a distinctly shallower dose-response. In contrast, there was highly attenuated stimulation of glucose uptake into muscle. Mechanistic studies indicated that IRPAs exploit tissue differences in receptor density and have additional distinctions pertaining to drug clearance and distribution. The hepato-adipose selective action of IRPAs is a potentially safer approach for treatment of diabetes.
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Diabetes Mellitus Experimental/tratamiento farmacológico , Diabetes Mellitus Tipo 1/tratamiento farmacológico , Hipoglucemiantes/farmacología , Insulina/farmacología , Receptor de Insulina/agonistas , Tejido Adiposo/efectos de los fármacos , Tejido Adiposo/metabolismo , Aloxano/administración & dosificación , Aloxano/toxicidad , Animales , Glucemia/efectos de los fármacos , Glucemia/metabolismo , Células CHO , Cricetulus , Diabetes Mellitus Experimental/sangre , Diabetes Mellitus Experimental/inducido químicamente , Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Tipo 1/sangre , Diabetes Mellitus Tipo 1/inducido químicamente , Diabetes Mellitus Tipo 1/metabolismo , Células HEK293 , Humanos , Hipoglucemiantes/uso terapéutico , Insulina/uso terapéutico , Lipólisis/efectos de los fármacos , Hígado/efectos de los fármacos , Hígado/metabolismo , Masculino , Ratones , Ratas , Proteínas Recombinantes/farmacología , Proteínas Recombinantes/uso terapéutico , Transducción de Señal/efectos de los fármacos , Porcinos , Porcinos EnanosRESUMEN
We have identified a series of novel insulin receptor partial agonists (IRPAs) with a potential to mitigate the risk of hypoglycemia associated with the use of insulin as an antidiabetic treatment. These molecules were designed as dimers of native insulin connected via chemical linkers of variable lengths with optional capping groups at the N-terminals of insulin chains. Depending on the structure, the maximal activation level (%Max) varied in the range of â¼20-70% of native insulin, and EC50 values remained in sub-nM range. Studies in minipig and dog demonstrated that IRPAs had sufficient efficacy to normalize plasma glucose levels in diabetes, while providing reduction of hypoglycemia risk. IRPAs had a prolonged duration of action, potentially making them suitable for once-daily dosing. Two lead compounds with %Max values of 30 and 40% relative to native insulin were selected for follow up studies in the clinic.
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Diabetes Mellitus Tipo 2 , Hipoglucemia , Animales , Glucemia , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Perros , Hipoglucemia/tratamiento farmacológico , Hipoglucemiantes/farmacología , Hipoglucemiantes/uso terapéutico , Insulina/uso terapéutico , Receptor de Insulina , Porcinos , Porcinos Enanos , Índice TerapéuticoRESUMEN
One new dimeric diterpenoid, 8(14)-enyl-pimar-2'(3')-en-4'(18')-en-15'(16')-endolabr- 16,15,2',3'-oxoan-16-one (1) and five known terpenoids: Tagalsin C (2), Tagalsin I (3), lup-20(29)-ene-3ß,28-diol (4), 3-oxolup-20(29)-en-28-oic acid (5) and 28-hydroxylup- 20(29)-en-3-one (6) were isolated from the roots of the mangrove plant Ceriops tagal. Their structures and relative stereochemistry were elucidated by means of extensive NMR, IR and MS analysis. The antifouling activity against larval settlement of the barnacle Balanus albicostatus were evaluated using capsaicin as a positive control. All these terpenoids exhibited antifouling activity against cyprid larvae of the barnacle without significant toxicity. The structure-activity relationship results demonstrated that the order of antifouling activity was diterpenoid (Compound 2) > triterpenoid (Compounds 4, 5 and 6) > dimeric diterpenoid (Compounds 1 and 3). The functional groups on the C-28 position of lupane triterpenoid significantly affect the antifouling activity. The diterpenoid dimmer with two identical diterpenoid subunits might display more potent antifouling activity than one with two different diterpenoid subunits. The stability test showed that Compounds 2, 4, 5 and 6 remained stable over 2-month exposure under filtered seawater.
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Rhizophoraceae/química , Terpenos/química , Animales , Larva/efectos de los fármacos , Espectroscopía de Resonancia Magnética , Conformación Molecular , Raíces de Plantas/química , Raíces de Plantas/metabolismo , Rhizophoraceae/metabolismo , Relación Estructura-Actividad , Terpenos/aislamiento & purificación , Terpenos/farmacología , Thoracica/efectos de los fármacos , Thoracica/crecimiento & desarrolloRESUMEN
Settlement and metamorphosis of planktonic larvae into benthic adults are critical components of a diverse range of marine invertebrate-mediated processes such as the formation of mussel beds and coral reefs, the recruitment of marine shellfisheries, and the initiation of macrobiofouling. Although larval settlement and metamorphosis induced by natural chemical cues is widespread among marine invertebrates, the mechanisms of action remain poorly understood. Here, we identified that the molecular target of adenosine (an inducer of larval settlement and metamorphosis from conspecific adults in the invasive biofouling mussel Mytilopsis sallei) is adenosine kinase (ADK). The results of transcriptomic analyses, pharmacological assays, temporal and spatial gene expression analyses, and siRNA interference, suggest that ATP-dependent phosphorylation of adenosine catalyzed by ADK activates the downstream AMPK-FoxO signaling pathway, inducing larval settlement and metamorphosis in M. sallei. This study not only reveals the role of the ADK-AMPK-FoxO pathway in larval settlement and metamorphosis of marine invertebrates but it also deepens our understanding of the functions and evolution of adenosine signaling, a process that is widespread in biology and important in medicine.
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Adenosina/análogos & derivados , Adenosina/farmacología , Bivalvos/efectos de los fármacos , Larva/efectos de los fármacos , Metamorfosis Biológica/efectos de los fármacos , Transducción de Señal/efectos de los fármacos , Proteínas Quinasas Activadas por AMP/metabolismo , Adenosina/metabolismo , Adenosina Quinasa/metabolismo , Secuencia de Aminoácidos , Animales , Factores de Transcripción Forkhead/metabolismo , Etiquetas de Fotoafinidad/metabolismo , Etiquetas de Fotoafinidad/farmacología , Transcriptoma/efectos de los fármacosRESUMEN
The development of environmentally friendly and sustainable corrosion protection technologies is a longstanding yet difficult problem, especially for the marine environment. The utilization of living biofilms isolated from local environments is an effective strategy for infrastructure protection. In this study, three aerobic marine bacteria, Tenacibaculum mesophilum D-6, Tenacibaculum litoreum W-4, and Bacillus sp. Y-6, with strong biofilm-forming abilities were isolated and evaluated for the corrosion protection of X80 carbon steel. The corrosion inhibitory effect of the bacteria was found to be closely related to their biofilm-forming abilities. This conclusion was corroborated by biofilm characterization, electrochemical tests, weight loss analysis, and corrosion product analysis. Moreover, secreted extracellular polymeric substances were identified to play significant roles in corrosion inhibition. Herein, we proposed a novel, eco-friendly, and cost-effective method for corrosion protection of carbon steels in the marine environment, providing guiding principles for identifying corrosion inhibitory bacteria from the local marine environment.