Marine Sources Research Articles

Green Medicine: Advancing Antimicrobial Solutions with Diverse Terrestrial and Marine Plant-Derived Compounds

Infectious diseases continue to cause global morbidity and mortality. The rise of drug-resistant pathogens is a major challenge to modern medicine. Plant-based antimicrobials may solve this issue; hence, this review discussed in detail plant-sourced antimicrobial drugs as an alternative toward bacterial, fungal, and viral pathogens. Plant-derived chemicals from various sources such as marine, medicinal, and non-medicinal sources have diverse antimicrobial properties. Complex chemical profiles from these sources allow these molecules to interact with several targets in the microbial pathogens. Due to their multi-component composition, these compounds are more effective and less likely to acquire resistance than single-target antibiotics. Medicinal herbs have long been used for their antimicrobial properties; however, non-medicinal plants have also been identified for their antimicrobial properties. Other interesting new pathways for the identification of antimicrobials include marine plants, which contain a wide variety of metabolites that are both distinct and varied. We have conducted a thorough literature search for the medicinal, non-medicinal, and marine plant-derived molecules with antimicrobial roles from databases which include Scopus, PubMed, Google Scholar, and Web of Science. The review also discussed the synergistic potential of combining these plant-derived compounds with traditional antimicrobial drugs to attenuate the microbial pathogenesis. Based on the existing research and advancements, the review article emphasizes the importance of continuing research into plant-based antimicrobials from these many sources and integrating them with existing therapies to combat the rising threat of drug-resistant infections.

Biofunctional applications of Chitosan in Dentistry – An Overview

Chitosan due to its unique properties has attracted materials scientists globally to explore it for bio-dental applications. In dentistry, chitosan is also shown wide applications. The creation of effective biomaterials for the prevention and treatment of dental disorders is a challenge for researchers in the present scenario. The natural semi-synthetic polysaccharide based biomaterial Chitosan is obtained from the marine source chitin. Due to its peculiar characteristics, chitosan offers benefits in biomedicine and can be utilized in the development of capsules (micro and nanoparticles), powders, scaffolds, films, beads, hydrogels, and bandages. Chitosan offers its benefits as an anti-microbial agent, mucoadhesive, biomimetic mineralization Teeth hardening action due to its remineralizing property which leads to the search and focus of chitosan towards dental applications. Translation of research to clinical applications is better suited for chitosan in terms of its multifactorial activities. Therefore, this article provides an overview of chitosan, which mainly covers the basic information of chitosan, with a focus on different techniques of preparation of chitosan based formulations. It also explores the usage of chitosan in the treatment of various dental disorders.

Green and sustainable technologies for extraction of carotenoids from natural sources: a comprehensive review.

In recent years, driven by increasing consumer demand for natural and healthy convenient foods, the food industry has been shifting from synthetic to natural products. This shift is also reflected in the growing popularity of non-conventional extraction methods for pigments, which are favored for sustainability and environment-friendliness compared to conventional processes. This review aims to investigate the extraction of carotenoids from a variety of natural sources, including marine sources like fungus, microalgae, and crustaceans, as well as widely studied plants like tomatoes and carrots. Additionally, it delves into the recovery of valuable carotenoids from waste products like pomace and peels, highlighting the nutritional and environmental benefits. The review also emphasizes the role of green solvents such limonene, vegetable oils, ionic liquids, supercritical fluids, and natural deep eutectic solvents in effective and ecologically friendly carotenoid extraction. These technologies support the ideas of a circular and sustainable economy in addition to having a smaller negative impact on the environment. Overall, the present study highlights the crucial importance of green extraction technologies in achieving the dual goals of sustainability and public safety.

People of the Sea, or of the Soil? How the Balance of Marine and Terrestrial Resource Availability Informs Maximum Population on Four Polynesian Islands

AbstractMost studies of the food resource potential of early Polynesian populations focus exclusively on agricultural potential, and specifically starchy staples, despite the importance of marine resources to the Polynesians. To more accurately estimate total precontact food resource availability, we characterized the terrestrial and near-shore marine environments of four Polynesian islands: Moʻorea, Maupiti, Mangareva and Taravai. We estimate the agricultural potential of each island after a consideration of the ecological factors related to productivity. We also estimate the productivity of the near-shore marine environment as a function of surface area. Using a range of fish yield scenarios from Pacific subsistence systems we scale relative measures of faunal food biomass derived from local archaeological excavations to generate absolute biomass estimates. We convert our estimates of agricultural and fished/foraged food potential into a maximum population size based on calorie availability. Moʻorea’s fertile valleys and wetlands would potentially generate sufficient food energy, mostly from starchy staples, to support a considerable population, many times larger than the other islands. In the most likely fish yield scenario Moʻorea gets only 0.4% of its calories from marine sources, while the others range from 7–18%. These relative inputs reflect the vast superiority in productivity (in terms of calories per km2) of agricultural vs near-shore marine zones. We also find that population size on islands with smaller fringing reefs, such as Moʻorea, may have been limited by a lack of fish protein. Moʻorea’s maximum population is approximately halved when diet breadth is considered.

Fundamental Understanding of Marine Applications of Molten Salt Reactors: Progress, Case Studies, and Safety

Marine sources contribute approximately 2% of global energy-related CO₂ emissions, with the shipping industry accounting for 87% of this total, making it the fifth-largest emitter globally. Environmental regulations by the International Maritime Organization (IMO), such as the MARPOL (International Convention for the Prevention of Pollution from Ships) treaty, have driven the exploration of alternative green energy solutions, including nuclear-powered ships. These ships offer advantages like long operational periods without refueling and increased cargo space, with around 200 reactors already in use on naval vessels worldwide. Among advanced reactor concepts, the molten salt reactor (MSR) is particularly suited for marine applications due to its inherent safety features, compact design, high energy density, and potential to mitigate nuclear waste and proliferation concerns. However, MSR systems face significant challenges, including tritium production, corrosion issues, and complex behavior of volatile fission products. Understanding the impact of marine-induced motion on the thermal–hydraulic behavior of MSRs is crucial, as it can lead to transient design basis accident scenarios. Furthermore, the adoption of MSR technology in the shipping industry requires overcoming regulatory hurdles and achieving global consensus on safety and environmental standards. This review assesses the current progress, challenges, and technological readiness of MSRs for marine applications, highlighting future research directions. The overall technology readiness level (TRL) of MSRs is currently at 3. Achieving TRL 6 is essential for progress, with individual components needing TRLs of 4–8 for a demonstration reactor. Community Readiness Levels (CRLs) must also be addressed, focusing on public acceptance, safety, sustainability, and alignment with decarbonization goals.

Resolving dynamic and static characteristics of the fouling by alginate in membrane distillation via optical coherence tomography

In an effort to improve the efficiency of membrane distillation (MD) for recovering water from a high salinity feed, recent studies paid special attention to the effects of fouling by alginate, which is an anionic polysaccharide ubiquitously involved in marine sources. However, it is technically challenging to in-situ characterize the gel layer with a relatively low degree of optical visibility. Therefore, a particle-assisted strategy was proposed by this study to improve the characterization based on optical coherence tomography (OCT) and thereby resolve both the dynamic (i.e., relating to the spatiotemporal evolution) and static (i.e., relating to the morphological properties) characteristics for developing a gel layer in the MD process with an alginate-containing feed. When confirming the effectiveness of employing differently sized polystyrene microbeads as the tracer combined with alginate aggregates and the detector transferred into the network of hydrogel, all the characterization results reveal that the alginate aggregates could be deposited in a heterogeneous way to form a steady structure composed of a static layer (∼150 μm) and a dynamic layer (∼50 μm); ∼25% to ∼30% of the cross-sectional area could be dominated by submicron- and micron-sized fluid channels in the static layer. This study not only provides deeper insights into the fouling by alginate in MD, but also broadens the spectrum of OCT-based characterization.

Marine bioactives: a new frontier in neurosurgical therapeutics.

Bioactives derived from marine sources are opening up new therapeutic opportunities for neurosurgery. These include tissue regeneration, neuroprotection, and infection control. These molecules derived from extreme marine conditions have generated new modes of action, for example, selective inhibition of voltage-gated ion channels and influencing pathways of neuroinflammation. Representative examples include chitosan for nerve regeneration, conotoxins for pain modulation, and fucoidan for neuroprotection. Despite therapeutic promise, major challenges remain: those of sustainable sourcing and regulatory validation. This letter points up the potential of marine bioactives to change neurosurgical care and challenges the brain communities to work together across disciplines in order to make that happen.

Recent Advances in Phenazine Natural Products: Chemical Structures and Biological Activities.

Phenazine natural products are a class of colored nitrogen-containing heterocycles produced by various microorganisms mainly originating from marine and terrestrial sources. The tricyclic ring molecules show various chemical structures and the decorating groups dedicate extensive pharmacological activities, including antimicrobial, anticancer, antiparasitic, anti-inflammatory, and insecticidal. These secondary metabolites provide natural materials for screening and developing medicinal compounds in the field of medicine and agriculture due to biological activities. The review presents a systematic summary of the literature on natural phenazines in the past decade, including over 150 compounds, such as hydroxylated, O-methylated, N-methylated, N-oxide, terpenoid, halogenated, glycosylated phenazines, saphenic acid derivatives, and other phenazine derivatives, along with their characterized antimicrobial and anticancer activities. This review may provide guidance for the investigation of phenazines in the future.

Carbon and nitrogen sources in tropical coastal lagoon food webs under variable hydrological conditions

Whilst the impact of continental and marine nutrient sources on the ecological functioning of coastal food webs is well investigated in temperate regions, tropical ecosystems remain less well understood, in particular coastal lagoons. In this study, the sources of carbon and nitrogen in a coastal lagoon system in the southeast of Madagascar are traced using stable isotopes of carbon (δ13C) and nitrogen (δ15N). Three interconnected coastal lagoons with different degree of river influence and eutrophication are investigated. Their food webs are assessed with respect to spatial and seasonal (wet and dry seasons) variations in lagoon water conditions, as well as with respect to the sources of nutrients and organic matters. Results show that river input is the main source of NO3−, and that NO3− supply is significantly higher during the wet season. In contrast, NH4+ is produced internally in the lagoon, and concentrations are higher during the dry season. A lower δ13C value observed in particulate organic matter (POM; proxy of phytoplankton) indicates terrestrial-riverine carbon inputs, which generally have low δ13C values. During the dry season, exceptionally high δ15N values of lagoon POM suggest the uptake of newly produced lagoon water NH4+ and/or the 15N enrichment of lagoon POM pool due to mineralization, resulting in 15N enrichment in consumers. Moreover, δ13C and δ15N values of consumers (fishes and invertebrates) reflect predominantly those of lagoon POM and sediment organic matter (SOM), suggesting that consumers primarily depend on lagoon POM and SOM as sources of carbon and nitrogen. The δ15N values in consumers further indicate that some species feed on more than one trophic level, suggesting flexible foraging strategy of consumers as a function of food source availability. This study demonstrates the roles of both river inflow and sediment in supplying carbon and nitrogen to a coastal lagoon food web, documenting the ecological implications of seasonal variations in lagoon hydrological conditions.

Spatial and seasonal variability of chlorophyll-a, total suspended matter, and colored dissolved organic matter in the Sundarban mangrove forest using earth observation and field data

The Sundarbans, the world's largest mangrove forest, confronts potential threats from various anthropogenic activities leading to degradation of its aquatic ecosystem. To examine the current status of the aquatic ecosystem, this study aimed to evaluate the spatial and seasonal fluctuation of three principal water quality attributes namely Chlorophyll-a (Chl-a), Total Suspended Matter (TSM), and Colored Dissolved Organic Matter (CDOM) in the complex tidal river systems of the Sundarban mangroves forest using earth observation and in-situ data. A set of two bio-optical algorithms, Ocean color-2 (OC-2) and Ocean color-3 (OC-3), were applied to measure Chl-a concentration, Green/NIR and the Red/NIR band ratio algorithms were used for TSM and the Case-2 Regional Coast Color (C2RCC) processor in the SNAP software was applied to obtain CDOM concentration in study area. A total of 50 in-situ samples were collected during post-monsoon and pre-monsoon to validate the results. Our results clearly demonstrated seasonal variability with higher Chl-a concentrations in post-monsoon than pre-monsoon. This was due to the OC-2 algorithm which produced better results with R2 = 0.73, RMSE = 0.27 for post-monsoon and R2 = 0.55, RMSE = 0.32 for pre-monsoon. Whilst, TSM concentration performed the best with R2 = 0.77; RMSE = 15.82 and R2 = 0.65; RMSE = 33.96 in post-monsoon and pre-monsoon according to the Green/NIR band ratio method. The nearshore and narrow waterway regions had the highest concentrations of TSM and Chl-a, whereas the offshore regions had the lowest. Strong association were observed between the in-situ and satellite derive absorption coefficient, aCDOM (m−1). The R2 for a CDOM during pre-monsoon was 0.65 and throughout the post-monsoon, it was 0.74. Pre-monsoon concentrations were found to be higher due to marine sources and higher wind speeds, possibly due to sediment resuspension. This kind of baseline evaluation will help to detect threats, direct preventive measures for the protection of biodiversity, and deepen our knowledge of these distinct ecosystems. The results will help develop flexible management and preservation plans that can adjust to both natural and man-made changes.

Understanding sediment and carbon accumulation in macrotidal minerogenic saltmarshes for climate resilience

Coastal saltmarshes play an essential role in providing services such as sediment and carbon storage, coastal protection and support for biodiversity. Despite their importance, understanding the factors controlling sediment and carbon accumulation in these minerogenic saltmarshes remains challenging due to their diversity and site-specific characteristics. Understanding the respective role of these drivers is essential for effective coastal management, particularly for mitigating the impacts of climate change. This study evaluates the control of forcing factors on the lateral and vertical morphological evolution and carbon burial rates of three minerogenic saltmarshes located on the French Atlantic coast (Pertuis Charentais region). By focusing on these sites, the study isolates specific factors such as wind and wave exposure, inundation frequency, and sediment availability, while minimizing confounding influences like climate and tidal range. Results reveal significant lateral expansion of saltmarsh boundaries towards the sea across all sites, with the highest rates of progradation observed in the protected areas influenced by geomorphological features such as sand spits and sheltered bay heads. Sediment and mass accumulation rates (SAR; MAR), derived from 210Pb and 137Cs profiles of sediment cores (n = 14), range from 0.48 to 2.22 cm yr−1, among the highest reported globally, with notable variability within and between sites. Inundation frequency and accommodation space explain SAR variability within sites, while sediment availability predominantly determines spatial differences in vertical accumulation rates between sites. Organic carbon burial rates range from 75 to 345 gC m−2 yr−1, and show a strong correlation with SAR (r = 0.9, p < 0.001, n = 13) but no dependence on carbon content or density (r = 0.2, p > 0.05, n = 13). This highlights the role of sediment input in the accumulation and sequestration of carbon by minerogenic saltmarshes. Furthermore, isotopic analysis indicates a marine source dominance in organic carbon sediment. This research provides insights into how different environmental conditions affect saltmarsh morphological evolution and carbon sequestration rates, informing targeted coastal management strategies focused on enhancing ecosystem resilience and climate resilience.

From Sea to Lab: Angiotensin I-Converting Enzyme Inhibition by Marine Peptides-Mechanisms and Applications.

To reveal potent ACE inhibitors, researchers screen various bioactive peptides from several sources, and more attention has been given to aquatic sources. This review summarizes the recent research achievements on marine peptides with ACE-inhibitory action and application. Marine peptides are considered excellent bioactives due to their large structural diversity and unusual bioactivities. The mechanisms by which these marine peptides inhibit ACE include competitive binding to ACEs' active site, interfering with ACE conformational changes, and avoiding the identification of substrates. The unique 3D attributes of marine peptides confer inhibition advantages toward ACE activity. Because IC50 values of marine peptides' interaction with ACE are low, structure-based research assumes that the interaction between ACE and peptides increased the therapeutic application. Numerous studies on marine peptides focused on the sustainable extraction of ACE-inhibitory peptides produced from several fish, mollusks, algae, and sponges. Meanwhile, their potential applications and medical benefits are worth investigating and considering. Due to these peptides exhibiting antioxidant, antihypertensive, and even antimicrobial properties simultaneously, their therapeutic potential for cardiovascular disease and other illnesses only increases. In addition, as marine peptides show better pharmacological benefits, they have increased absorption rates and low toxicity and could perhaps be modified for better stability and bioefficacy. Biotechnological advances in peptide synthesis and formulation have greatly facilitated the generation of peptide-based ACE inhibitors from marine sources, which subsequently offer new treatment models. This article gives a complete assessment of the present state of knowledge about marine organism peptides as ACE inhibitors. In addition, it emphasizes the relevance of additional investigation into their mechanisms of action, the optimization of manufacturing processes, and assessment in in vivo, preclinical, and clinical settings, underlining the urgency and value of this study. Using marine peptides for ACE inhibition not only broadens the repertory of bioactive compounds but also shows promise for tackling the global health burden caused by cardiovascular diseases.

Hydroxyapatite synthesis and characterization from marine sources: A comparative study

BackgroundHydroxyapatite (HAP) is a biocompatible material widely used in biomedical applications. Recent studies have explored various marine sources for HAP synthesis, demonstrating its potential for diverse applications. ObjectiveThis study aims to compare the characteristics of hydroxyapatite synthesized from sea shells and fish bones, specifically from the shells of Scylla olivacea (orange mud crab) and bones of Eleutheronema tetradactylum (fourfinger threadfin). Materials & methodsHAP was synthesized from Scylla olivacea shells and Eleutheronema tetradactylum bones. The synthesized HAP underwent comprehensive characterization, including scanning electron microscopy (SEM) for structural analysis, hemocompatibility testing, antibacterial assays, and energy-dispersive X-ray spectroscopy (EDS) analysis. ResultsSEM revealed a complex structure of HAP with a clustered arrangement and biofilm-like features. HAP derived from crab shells exhibited superior structural properties compared to that from fish bones. Both sources demonstrated good hemocompatibility, essential for biomedical applications. The antibacterial assays indicated effective antibacterial properties for both HAP sources, with crab shell-derived HAP showing slightly better performance. EDS analysis confirmed the presence of key elements necessary for HAP, with a consistent composition in both sources. ConclusionOur study concludes that hydroxyapatite derived from Scylla olivacea shells exhibits superior properties compared to that from Eleutheronema tetradactylum bones. This research establishes a precedent for future investigations into other marine species, thereby broadening the scope and potential of hydroxyapatite synthesis from natural sources.

Chemoproteomics of Marine Natural Product Naamidine J Unveils CSE1L as a Therapeutic Target in Acute Lung Injury.

Acute lung injury is a devastating illness characterized by severe inflammation mediated by aberrant activation of macrophages, resulting in significant morbidity and mortality, highlighting the urgent need for novel pharmacological targets and drug candidates. In this study, we identified a novel target for regulating inflammation in macrophages and acute lung injury via chemical proteomics and genetics based on a marine alkaloid, naamidine J (NJ). The structures of NJ-related naamidine alkaloids were first confirmed or revised by a combination of quantum chemical calculations and X-ray diffraction analysis. NJ was found as a potential anti-inflammatory agent by screening our compound library, and CSE1L was identified by chemoproteomics as a main cellular target of NJ to inhibit inflammation in macrophages and protect against acute lung injury. Mechanistically, we demonstrated that NJ directly interacted with CSE1L on the sites of His745 and Phe903 and then inhibited the nuclear translocation and transcriptional activity of transcription factor SP1, thereby suppressing inflammation in macrophages and ameliorating acute lung injury. Taken together, these findings have uncovered a novel pharmacological target for the treatment of acute lung injury and have also provided a potential druggable pocket of CSE1L and a lead compound or an available chemical tool from marine sources for investigating CSE1L function and developing novel drug candidates against acute lung injury.

Marine Bioactives in Cancer Prevention and Treatment

The twice high incidence risk of cancer in men was the reason for over a million new cases and deaths recorded globally in 2018. The two most frequent cancer-related fatalities are lung and breast cancer. Novel therapies have been made possible by developments in immunotherapy, biology, and pharmaceutical design. Novel cancer prevention and therapy elements are being made possible by technological advancements and studies on marine natural resources. The creation of innovative anticancer medications is utilizing marine-derived natural products (MNPs). Biologically active polyketides, high molecular weight organic sugars, terpenes, bioengineered alkaloids, and marine animal peptides are some examples of these MNPs. Anticancer drugs are also developed with the help of plants, animals, invertebrates, and microbes found on land. The National Cancer Institute is exploring the potential of nutrition and food in cancer prevention despite the absence of preclinical and clinical data. Marine organisms contain bioactive compounds that have potential anticancer effects. Polyphenols, polysaccharides, and alkaloids are some of the active components found in marine species. Polyphenols, found in edible seaweeds like Palmaria palmata, can lower cancer cell division and proliferation, while polysaccharides trigger the innate immune system, causing apoptosis in pancreatic islet cancer and human leukemia cells. Alkaloids, derived from marine sources, can inhibit cancer cell development. Peptides, found in various plant species, have shown cytotoxic effects on several human cell lines, including pancreatic, breast, lung, and bladder cancers. Marine drug approval faces challenges like the possibility of a resurgence of different metabolites due to environmental conditions and limited lead compound availability.

Marine Bioactive Molecules as Inhibitors of the Janus Kinases: A Comparative Molecular Docking and Molecular Dynamics Simulation Approach.

A treasure trove of naturally occurring biomolecules can be obtained from sea living organisms to be used as potential antioxidant and anti-inflammatory agents. These bioactive molecules can target signaling molecules involved in the severity of chronic autoimmune diseases such as rheumatoid arthritis (RA). The intracellular tyrosine kinases family, Janus kinases (JAKs, includes JAK1, JAK2, and JAK3), is implicated in the pathogenesis of RA through regulating several cytokines and inflammatory processes. In the present study, we conducted molecular docking and structural analysis investigations to explore the role of a set of bioactive molecules from marine sources that can be used as JAKs' specific inhibitors. Around 200 antioxidants and anti-inflammatory molecules out of thousands of marine molecules found at the Comprehensive Marine Natural Products Database (CMNPD) website, were used in that analysis. The details of the interacting residues were compared to the recent FDA approved inhibitors tofacitinib and baricitinib for data validation. The shortlisted critical amino acids residues of our pharmacophore-based virtual screening were LYS905, GLU957, LEU959, and ASP1003 at JAK1, GLU930 and LEU932 at JAK2, and GLU905 and CYS909 of JAK3. Interestingly, marine biomolecules such as Sargachromanol G, Isopseudopterosin E, Seco-Pseudopterosin, and CID 10071610 showed specific binding and significantly higher binding energy to JAK1 active/potential sites when being compared with the approved inhibitors. In addition, Zoanthoxanthin and Fuscoside E bind to JAK2's critical residues, GLU930 and LEU932. Moreover, Phorbaketal and Fuscoside E appear to be potential candidates that can inhibit JAK3 activity. These results were validated using molecular dynamics simulation for the docked complexes, JAK1(6sm8)/SG, JAK2 (3jy9)/ZAX, and JAK3 (6pjc)/Fuscoside E, where stable and lower binding energy were found based on analyzing set of parameters, discussed below (videos are attached). A promising role of these marine bioactive molecules can be confirmed in prospective preclinical/clinical investigations using rheumatoid arthritis models.

Significance of research on natural products from marine-derived Aspergillus species as a source against pathogenic bacteria.

Bacterial infections pose a significant clinical burden on global health. The growing incidence of drug-resistant pathogens highlights the critical necessity to identify and isolate bioactive compounds from marine resources. Marine-derived fungi could provide novel lead compounds against pathogenic bacteria. Due to the particularity of the marine environment, Aspergillus species derived from marine sources have proven to be potent producers of bioactive secondary metabolites and have played a considerable role in advancing drug development. This study reviews the structural diversity and activities against pathogenic bacteria of secondary metabolites isolated from marine-derived Aspergillus species over the past 14 years (January 2010-June 2024), and 337 natural products (including 145 new compounds) were described. The structures were divided into five major categories-terpenoids, nitrogen-containing compounds, polyketides, steroids, and other classes. These antimicrobial metabolites will offer lead compounds to the development and innovation of antimicrobial agents.

Bridging gas and aerosol properties between the northeastern US and Bermuda: analysis of eight transit flights

Abstract. The western North Atlantic Ocean is strongly influenced by continental outflow, making it an ideal region to study the atmospheric transition from a polluted coastline to the marine environment. Utilizing eight transit flights between the NASA Langley Research Center (LaRC) in Hampton, Virginia, and the remote island of Bermuda from NASA's Aerosol Cloud meTeorology Interactions oVer the western ATlantic Experiment (ACTIVATE), we examine the evolution of trace gas and aerosol properties off the US East Coast. The first pair of flights flew along the wind trajectory of continental outflow, while the other flights captured a mix of marine and continental air mass sources. For measurements within the boundary layer (BL), there was an offshore decline in particle N&lt;100 nm, N&gt;100 nm, CH4, CO, and CO2 concentrations, all leveling off around ∼900 km offshore from the LaRC. These trends are strongest for the first pair of flights. In the BL, offshore declines in organic mass fraction and increases in sulfate mass fraction coincide with increasing hygroscopicity based on f(RH) measurements. Free troposphere measurements show a decline in N&lt;100 nm, but other measured parameters are more variable when compared to the prominent offshore gradients seen in the BL. Pollution layers exist in the free troposphere, such as smoke plumes, that can potentially entrain into the BL. This work provides detailed case studies with a broad set of high-resolution measurements to further our understanding of the transition between continental and marine environments.

Natural linoleic acid from marine fungus Eutypella sp. F0219 blocks KEAP1/NRF2 interaction and ameliorates MASLD by targeting FABP4

Ectopic lipid accumulation induced lipotoxicity plays a crucial role in exacerbating the development of metabolic dysfunction-associated steatotic liver disease (MASLD), which affects over 30 % of the worldwide population and 85 % of the obese population. The growing demand for effective therapeutic agents highlights the need for high-efficacy lipotoxicity ameliorators and relevant therapeutic targets in the fight against MASLD. This study aimed to discover natural anti-lipotoxic and anti-MASLD candidates and elucidate the underlying mechanism and therapeutic targets. Utilizing palmitic acid (PA)-induced HepG-2 and primary mouse hepatocyte models, we identified linoleic acid (HN-002), a ligand of fatty acid binding protein 4 (FABP4), from the marine fungus Eutypella sp. F0219. HN-002 dose-dependently prevented lipid overload-induced hepatocyte damage and lipid accumulation, inhibited fatty acid esterification, and ameliorated oxidative stress. These beneficial effects were associated with improvements in mitochondrial adaptive oxidation. HN-002 treatment enhanced lipid transport into mitochondria and oxidation, inhibited mitochondrial depolarization, and reduced mitochondrial ROS (mtROS) level in PA-treated hepatocytes. Mechanistically, HN-002 treatment disrupted the interaction between KEAP1 and NRF2, leading to NRF2 deubiquitylation and nuclear translocation, which activated beneficial metabolic regulation. In vivo, HN-002 treatment (20 mg/kg/per 2 days, i. p.) for 25 days effectively reversed hepatic steatosis and liver injury in the fast/refeeding plus high-fat/high-cholesterol diet induced MASLD mice. These therapeutic effects were associated with enhanced mitochondrial adaptive oxidation and activation of NRF2 signaling in the liver. These data suggest that HN-002 would be an interesting candidate for MASLD by improving mitochondrial oxidation via the FABP4/KEAP1/NRF2 axis. The discovery offers new insights into developing novel anti- MASLD agents derived from marine sources.

Enantioselectivity in Vanadium-Dependent Haloperoxidases of Different Marine Sources for Sulfide Oxidation to Sulfoxides.

This study explores the reasons behind the variations in the enantioselectivity of the sulfoxidation of methyl phenyl sulfide by marine-derived vanadium-dependent haloperoxidases (VHPOs). Twelve new VHPOs of marine organisms were overexpressed, purified, and tested for their ability to oxidize sulfide. Most of these marine enzymes exhibited nonenantioselective behavior, underscoring the uniqueness of AnVBPO from the brown seaweed Ascophyllum nodosum and CpVBPO from the red seaweed Corallina pilulifera, which produce (R)- and (S)-sulfoxides, respectively. The enantioselective sulfoxidation pathway is likely due to direct oxygen transfer within the VHPO active site. This was demonstrated through molecular docking and molecular dynamics simulations, which revealed differences in the positioning of sulfide within AnVBPO and CpVBPO, thus explaining their distinct enantioselectivities. Nonenantioselective VHPOs probably follow a different oxidation pathway, initiating with sulfide oxidation to form a positively charged radical. Further insights were gained from studying the catalytic effect of VO43- on H2O2-driven sulfoxidation. This research improves the understanding of VHPO-mediated sulfoxidation and aids in developing biocatalysts for sulfoxide synthesis.