Developing natural marine products for treating liver diseases

In recent years,marine-derived bioactive compounds have gained increasing attention because of their higher biodiversity vs land-derived compounds.A number of marine-derived compounds are proven to improve lipid metabolism,modulate the gut microbiota,and possess anti-inflammatory,antioxidant,antibacterial,antiviral,and antitumor activities.With the increasing understanding of the molecular landscape underlying the pathogenesis of chronic liver diseases,interest has spiked in developing new therapeutic drugs and medicine food homology from marine sources for the prevention and treatment of liver diseases.

Determination of Selenium in Marine Aquatic Products by Hydride Generation-atomic Fluorescence Spectrometry (HG-AFS)

A method for the analysis of selenium in marine aquatic products by HG-AFS has been investigated. The method is based on the reduction of inorganic selenium to volatile SeH2 which is bubbled out by carrier gas of pure argon, and then swept to Ar-H2 flame quarts atomizer to measure its fluorescence intensity. The hydride generation, transportation, atomization and some instrumental parameters were studied by a kind of orthogonal design. The optimum conditions selected are as follows： reactive acidity, 20% HC1; the amount of NaBH4, 4.9mL; gas flow of argon, 600mLmin^-1; atomizing temperature, 200 ℃ ; negative high voltage, - 300V; light current, 100 mA; integral time, 7s. The detection limit of the presented method is 0.072μgL^-1 for selenium. The calibration curve shows a satisfactory line inthe concentration range from 0.000 to 1.000μgL^-1 Se. The recovery is 95.8%-102.2%.

Marine natural products with anti-inflammation effects

The ocean possesses a complex setting with high pressure,high salinity,oligotrophy,low temperature and weak illumination conditions.To survive and evolve in such harsh surroundings,marine organisms metabolize a series of chemicals known as secondary metabolites which indicate structural and functional diversity to adapt interspecific survival competition.During recent decades,the anti-inflammatory property of marine natural products has come under scrutiny as inflammation involves in the vast majority of diseases.Correspondingly,a myriad of marine bioactive molecules including terpenes,polypeptides,polysaccharides,sterols and many others may bring a new insight into inflammation therapies with multifarious sources and minimal side effects.And a better understanding of their mechanisms of anti-inflammation may lead to better treatments for numerous diseases.Herein,the research progress of marine-derived anti-inflammation compounds and the relevant mechanisms were reviewed,to provide a basis for the research and development of anti-inflammatory marine drugs.

Research on the Optimization and Upgrading of Marine Tourism Products in Shanghai

The ocean has become a new theme of the world economic competition.The development of marine industry is an inevitable measure to stabilize the sustainable and healthy development of China’s national economy.As a leading industry of marine economy,marine tourism has great potential for development.Marine tourism products are the foundation and power source of marine tourism development.The optimization of tourism products plays the most direct and key role in the upgrading of tourism industry.Shanghai,located in the center of Yangtze River Delta,is one of the most developed regions in China.However,with the increasing competition in the tourism market,the development of marine tourism is inevitable.This paper analyzes the general situation of marine tourism resources and the development status of tourism products in Shanghai,and probes into the specific countermeasures for the upgrading of its products,so as to promote the high-efficiency development of marine economy in Shanghai.

Proper Management of Standards Formulation for Marine Survey Instrument Products

The challenges of the ocean working environment and conditions require that marine instrumentsand equipment be highly reliable and environmentally adaptable.The various parts and componentsof marine instruments should be interchangeable,so as to reduce product costs and reasonably economizethe use of energy and material resources.This paper intruduces the importance of formulating marine instrumentproduct standards,the present conditions and problems of marine product standards,and proposesrelated measures and suggestions to sovle the problems.

LIQUID PRODUCTS MARINE TERMINAL OP-V OF KARACHI PORT,PAKISTAN WAS COMMISSIONED

The Karachi Port of Pakistan is a deep natural sea port with a history of 150 years. The Port has an 11 km long approach channel decaracted with buoys for proriding safe navigation of 75,000 DWT tankers,modern container vessels,bulk Karachi Port is the premier port of Pakistan and handles over 85 percent of the whole dry gen-

Diverse foraging strategies of breeding Swinhoe's Storm-petrel in the productive marginal sea of the Northwest Pacific

Understanding the foraging behavior is essential for investigating seabird ecology and conservation,as well as monitoring the well-being of the marine environment.Breeding seabirds adopt diverse foraging strategies to maximize energy gains and cope with the intensified challenges of parenting and self-maintenance.Such tradeoff may stem from the heterogeneity of food resources and the constraints of central place foraging.Nevertheless,abundant marine productivity could alleviate the energy limitation for seabirds,resulting in a consistent foraging approach.Here,we investigated the foraging strategy during the breeding season of a cryptic small-sized seabird,Swinhoe’s Storm-petrel(Hydrobates monorhis),in the Yellow Sea,a productive marginal sea of the Northwest Pacific.Using GPS tracking,we evaluated habitat preference,quantified the foraging strategy,and tested if environmental conditions and individual traits influence foraging trips.We found that Swinhoe’s Storm-petrels preferred nearshore areas with shallow water and engaged in primarily short foraging trips.Distinctive southeastward and southwestward strategies emerged when combining trip metrics,including foraging direction,duration,and maximum distance.The bathymetry,proximity to the coastline,and sea surface temperature differed in two foraging strategies.Foraging strategies exhibited flexibility between individuals,potentially explained by wing morphology,in which longer-winged birds are more likely to embark on longer-distance foraging trips.These findings highlight the impact of environmental factors and individual traits on seabirds’foraging decisions in productive marginal sea ecosystems.Our study also provides valuable insights into the foraging ecology of this Asian endemic storm-petrel.

Role of marine natural products in the development of antiviral agents against SARS‑CoV‑2:potential and prospects

A novel coronavirus,known as severe acute respiratory syndrome coronavirus 2(SARS-CoV-2),has surfaced and caused global concern owing to its ferocity.SARS-CoV-2 is the causative agent of coronavirus disease 2019;however,it was only discovered at the end of the year and was considered a pandemic by the World Health Organization.Therefore,the develop-ment of novel potent inhibitors against SARS-CoV-2 and future outbreaks is urgently required.Numerous naturally occurring bioactive substances have been studied in the clinical setting for diverse disorders.The intricate infection and replication mechanism of SARS-CoV-2 offers diverse therapeutic drug targets for developing antiviral medicines by employing natural products that are safer than synthetic compounds.Marine natural products(MNPs)have received increased attention in the development of novel drugs owing to their high diversity and availability.Therefore,this review article investigates the infection and replication mechanisms,including the function of the SARS-CoV-2 genome and structure.Furthermore,we highlighted anti-SARS-CoV-2 therapeutic intervention efforts utilizing MNPs and predicted SARS-CoV-2 inhibitor design.

Heterologous expression facilitates the discovery and characterization of marine microbial natural products

Microbial natural products and their derivatives have been developed as a considerable part of clinical drugs and agricultural chemicals.Marine microbial natural products exhibit diverse chemical structures and bioactivities with substantial potential for the development of novel pharmaceuticals.However,discovering compounds with new skeletons from marine microbes remains challenging.In recent decades,multiple approaches have been de-veloped to discover novel marine microbial natural products,among which heterologous expression has proven to be an effective method.Facilitated by large DNA cloning and comparative metabolomic technologies,a few novel bioactive natural products from marine microorganisms have been identified by the expression of their biosynthetic gene clusters(BGCs)in heterologous hosts.Heterologous expression is advantageous for character-izing gene functions and elucidating the biosynthetic mechanisms of natural products.This review provides an overview of recent progress in heterologous expression-guided discovery,biosynthetic mechanism elucidation,and yield optimization of natural products from marine microorganisms and discusses the future directions of the heterologous expression strategy in facilitating novel natural product exploitation.

Changes of marine productivity and sedimentary environment recorded by biogenic components in the Antarctica Ross Sea since the last deglaciation

Changes in the marine productivity and sedimentary environment since the last deglaciation in the Ross Sea are presented in this paper.Opal has replaced calcium carbonate as the major biogenic component and has a significantly positive correlation with total organic carbon(TOC),which indicates that siliceous phytoplankton controlled the absorption and release of carbon by the biological pump and was the main producer of marine organic matter.Using the AMS 14C age framework,foraminiferal fossils and redox sensitive elements(RSEs),we found that both the sedimentary environment and marine productivity changed clearly in^11 cal ka BP,which is more likely related with the melting and retreat of the Ross Ice Shelf.In addition,the increase of marine productivity promoted the sinking of more organic-matter to the seabed.A large proportion of oxygen in the bottom water body was consumed and more carbon dioxide was produced during the decomposition of organic matter,making the bottom water body more soluble to calcium carbonate.

Biogenic silica concentration as a marine primary productivity proxy in the Holsteinsborg Dyb, West Greenland, during the last millennium

We analyzed the biogenic silica(BSi)content and produced a diatom-based summer sea-surface temperature(SST)reconstruction for sediment core GC4 from the Holsteinsborg Dyb,West Greenland.Our aim was to reconstruct marine productivity and climatic fluctuations during the last millennium.Increased BSi content and diatom abundance suggest relatively high marine productively during the interval of AD 1000–1400,corresponding in time to the Medieval Warm Period(MWP).The summer SST reconstruction indicates relatively warm conditions during AD 900–1100,followed by cooling after AD 1100.An extended cooling period during AD 1400–1900 is characterized by prolonged low in reconstructed SST and high sea-ice concentration.The BSi values fluctuated during this period,suggesting varying marine productivity during the Little Ice Age(LIA).There is no significant correlation between the BSi content and SST during the last millennium,suggesting that the summer SST has little influence on marine productively in the Holsteinsborg Dyb.A good correspondence between the BSi content and the element Ti counts in core GC4 suggests that silicate-rich meltwater from the Greenland ice sheet was likely responsible for changes in marine productively in the Holsteinsborg Dyb.

Assessing the uncertainties of phytoplankton absorption-based model estimates of marine net primary productivity

Satellite-derived phytoplankton pigment absorption （aph） has been used as a key predictor of phytoplankton photosynthetic efficiency to estimate global ocean net primary production （NPP）. In this study, an aph-based NPP model （AbPM） with four input parameters including the photosynthetically available radiation （PAR）, diffuse attenuation at 490 nm （Ka（490））, euphotic zone depth （Zeu） and the phytoplankton pigment absorption coefficient （aph） is compared with the chlorophyll-based model and carbon-based model. It is found that the AbPM has significant advantages on the ocean NPP estimation compared with the chlorophyll-based model and carbon- based model. For example, AbPM greatly outperformed the other two models at most monitoring sites and had the best accuracy, including the smallest values of RMSD and bias for the NPP estimate, and the best correlation between the observations and the modeled NPPs. In order to ensure the robustness of the model, the uncertainty in NPP estimates of the AbPM was assessed using a Monte Carlo simulation. At first, the frequency histograms of simple difference （fi）, and logarithmic difference （~LOG） between model estimates and in situ data confirm that the two input parameters （Zeu and PAR） approximate the Normal Distribution, and another two input parameters （aph and Ka（490）） approximate the logarithmic Normal Distribution. Second, the uncertainty in NPP estimates in the AbPM was assessed by using the Monte Carlo simulation. Here both the PB （percentage bias）, defined as the ratio of ANPP to the retrieved NPP, and the CV （coefficient of variation）, defined as the ratio of the standard deviation to the mean are used to indicate the uncertainty in the NPP brought by input parameter to AbPM model. The uncertainty related to magnitude is denoted by PB and the uncertainty related to scatter range is denoted by CV. Our investigations demonstrate that PB of NPP uncertainty brought by all parameters with an annual mean of 5.5% covered a range of -5%-15% for the global ocean. The PB uncertainty of AbPM model was mainly caused by aph; the PB of NPP uncertainty brought by aph had an annual mean of 4.1% for the global ocean. The CV brought by all the parameters with an annual mean of 105% covered a range of 98%-134% for global ocean. For the coastal zone of Antarctica with higher productivity, the PB and CV of NPP uncertainty brought by all parameters had annual means of 7.1% and 121%, respectively, which are significantly larger than those obtained in the global ocean. This study suggests that the NPPs estimated by AbPM model are more accurate than others, but the magnitude and scatter range of NPP errors brought by input parameter to AbPM model could not be neglected, especially in the coastal area with high productivity. So the improving accuracy of satellite retrieval of input parameters should be necessary. The investigation also confirmed that the SST related correction is effective for improving the model accuracy in low temperature condition.

Antifouling Activities of Marine Bacteria Associated with Sponge (Sigmadocia sp.)

The present study aimed at assessing the antifouling activity of bacteria associated with marine sponges. A total of eight bacterial strains were isolated from the surface of sponge Sigmadocia sp., of them, SS02, SS05 and SS06 showed inhibitory activity against biofilm-forming bacteria. The extracts of these 3 strains considerably affected the extracellular polymeric substance producing ability and adhesion of biofilm-forming bacterial strains. In addition to disc diffusion assay, microalgal settlement assay was carried out with the extracts mixed with polyurethane wood polish and coated onto stainless steel coupons. The extract of strain SS05 showed strong microalgal settlement inhibitory activity. Strain SS05 was identified as Bacillus cereus based on its 16S rRNA gene. Metabolites of the bacterial strains associated with marine invertebrates promise to be developed into environment-friendly antifouling agents.

On the further development of marine ecotourism in Qingdao

As the companionate city of Beijing to hold the Olympic Games 2008, Qingdao has enormous potentialities in developing its own marine ecotourism industry. The paper mainly analyses the advantages and disadvantages in Qingdao’s developing the marine ecotourism industry, and make suggestions on how to make good use of this Olympic Games opportunity in order to quicken the development of marine ecotourism industry of Qingdao.

A new chloro-azaphilone derivative with pro-angiogenesis activity from the hadal trench-derived fungus Chaetomium globosum YP-106

A new chloro-azaphilone derivative chaetoviridin L(1)along with four known analogues,namely,chaetomugilin A(2),chaetoviridin E(3),chaetomugilin O(4),and chaephilone D(5),is isolated and identified from the culture extract of Chaetomium globosum YP-106,a deep-sea derived fungus obtained from the hadal zone seawater collected in the Yap Trench.Their structures were determined based on detailed interpretation of nuclear magnetic resonance(NMR)spectroscopic,mass spectrometry(MS)data analysis and comparison with the reported literature.The absolute configuration of the new compound was established by quantum chemical calculations of electronic circular dichroism(ECD).All the isolated compounds were evaluated for pro-angiogenesis activity using zebra fish model.Compounds 1,2,and 5significantly promoted the angiogenesis in a dose-dependent manner and thus,these compounds might be used as promising molecules for the treatment of cardiovascular disease.

Satellite remote sensing of ultraviolet irradiance on the ocean surface

Ultraviolet （UV） radiation has a significant influence on marine biological processes and primary productivity; however, the existing ocean color satellite sensors seldom contain UV bands. A look-up table of wavelength- integrated UV irradiance （280-400 nm） on the sea surface is established using the coupled ocean atmosphere radiative transfer （COART） model. On the basis of the look-up table, the distributions of the UV irradiance at middle and low latitudes are inversed by using the satellite-derived atmospheric products from the Aqua satellite, including aerosol optical thickness at 550 nm, ozone content, liquid water path, and the total precipitable water. The validation results show that the mean relative difference of the 10 d rolling averaged UV irradiance between the satellite retrieval and field observations is 8.20% at the time of satellite passing and 13.95% for the daily dose of UV. The monthly-averaged UV irradiance and daily dose of UV retrieved by satellite data show a good correlation with the in situ data, with mean relative differences of 6.87% and 8.43%, respectively. The sensitivity analysis of satellite inputs is conducted. The liquid water path representing the condition of cloud has the highest effect on the retrieval of the UV irradiance, while ozone and aerosol have relatively lesser effect. The influence of the total precipitable water is not significant. On the basis of the satellite-derived UV irradiance on the sea surface, a preliminary simple estimation of ultraviolet radiation＇s effects on the global marine primary productivity is presented, and the results reveal that ultraviolet radiation has a non-negligible effect on the estimation of the marine primary productivity.

Crystal Structure of 2-(2-Carboxy-4-hydroxy-6-methoxyphenoxy)-3,5-dichloro-6-hydroxy-4-methylbenzoic Acid 1-Methyl Ester

The title compound, neogeodin hydrate （C17H14C1208, CAS： 94540-50-8）, was derived from marine fungus Aspergilhts terreus CRIM301. It was unequivocally characterized by IR, NMR spectroscopies, and single-crystal X-ray crystallography and tested for various biological activities. Neogeodin hydrate crystallizes in the triclinic space group P1 with a = 8.1159（5） A, b = 8.2472（4） A, c= 14.1278（7） A, a = 81.448（2）°, β = 84.860（2）°, γ= 70.400（2）°, V = 880.13（8） A3; Z = 2. It comprises a diphenyl ether, asterric acid skeleton and dichloro substituents. The methoxyphenoxy rings of the inversely related molecules form a ribbon-like structure that is stabilized by O-H...O hydrogen bonds through the doubly disordered carboxyl groups and by C-H...O interactions, generating the same R22（8） ring motif. The chlorinated methylbenzoate rings, making mostly a right angle, link the parallel upper and lower ribbons via bifurcated O-H...O and C-H...O hydrogen bonds, yielding endless channels. The channels formed are further sustained by C-H...O and π...π interactions Neogeodin hydrate exhibits inhibition against superoxide anion radical formation in the xanthine/xanthine oxidase （XXO） assay, but has no aromatase inhibitory activity.

An overview of the marine natural products in clinical trials and on the market

The first marine natural products that served as leads or scaffolds for medicines were discovered in the middle of last century:the arabinosyl glycosides from the marine sponge Tectitethya crypta.Synthesis and modifications of the natural molecules generated antiviral and antileukemic drugs developed in the 1970’s and in the following decades,including the first effective treatment against HIV infection.With the improvement of techniques for the elucidation of chemical structure of the molecules,as well as chemical synthesis,especially from the 1990’s,there was an increase in the number of bioactive natural products characterized from marine organisms.New chemical structures with high specificity towards molecular targets in cells allowed the development of new drugs with indication for the treatment of several illnesses,from cancer to new antibiotics,and even neurological disorders.Currently there are at least 13 molecules derived from marine natural products on advanced clinical trials,and nine were approved to be used as medicines.Considering that in the past eight years,more than 1000 new compounds from marine organisms were described,per year,the expectation is that many more drugs will be derived from marine natural products in a near future.

Potentials of marine natural products against malaria, leishmaniasis, and trypanosomiasis parasites: a review of recent articles

Background:Malaria and neglected communicable protozoa parasitic diseases,such as leishmaniasis,and trypanosomiasis,are among the otherwise called diseases for neglected communities,which are habitual in underprivileged populations in developing tropical and subtropical regions of Africa,Asia,and the Americas.Some of the currently available therapeutic drugs have some limitations such as toxicity and questionable efficacy and long treatment period,which have encouraged resistance.These have prompted many researchers to focus on fin ding new drugs that are safe,effective,and affordable from marine environ merits.The aim of this review was to show the diversity,structural scaffolds,in-vitro or in-vivo efficacy,and recent progress made in the discovery/isolation of marine natural products(MNPs)with potent bioactivity against malaria,leishmaniasis,and trypanosomiasis.Main text:We searched PubMed and Google scholar using Boolean Operators(AND,OR,and NOT)and the combination of related terms for articles on marine natural products(MNPs)discovery published only in English language from January 2016 to June 2020.Twenty nine articles reported the isolation,identification and antiparasitic activity of the isolated compounds from marine environment.A total of 125 compounds were reported to have been isolated,out of which 45 were newly isolated compounds.These compounds were all isolated from bacteria,a fungus,sponges,algae,a bryozoan,cnidarians and soft corals.In recent years,great progress is being made on anti-malarial drug discovery from marine organisms with the isolation of these potent compounds.Comparably,some of these promising antikinetoplastid MNPs have potency better or similar to conventional drugs and could be developed as both antileishmanial and antitrypanosomal drugs.However,very few of these MNPs have a pharmaceutical destiny due to lack of the following:sustainable production of the bioactive compounds,stan da rd efficient screening methods,knowledge of the mechanism of action,partnerships between researchers and pharmaceutical industries.Conclusions:It is crystal clear that marine organisms are a rich source of antiparasitic compounds,such as alkaloids,terpenoids,peptides,polyketides,terpene,coumarins,steroids,fatty acid derivatives,and lactones.The current and future technological innovation in natural products drug discovery will bolster the drug armamentarium for malaria and neglected tropical diseases.

In vitro antimicrobial and synergistic effect of essential oil from the red macroalgae Centroceras clavulatum (C. Agardh) Montagne with conventional antibiotics

Objective:To study the chemical profile,antimicrobial properties,and synergistic effect with known antibiotics of essential oil extracted from the marine red macroalgae Centroceras clavulatum(C.Agardh)Montagne,collected in Morocco.Methods:The chemical composition of the oil was analyzed by gas chromatography-mass spectrometry.The oil was evaluated for antibacterial(Pseudomonas aeruginosa,Escherichia coli,Bacillus subtilis,Micrococcus luteus,Staphylococcus aureus,and Klebsiella pneumoniae),and antifungal activity(Candida albicans,Candida glabrata,Candida krusei,and Candida parapsilosis),by the disc diffusion method.The minimum inhibitory and minimum microbicidal concentrations of the oil were determined,as well as the synergistic effects of its application combined with the antibiotics ciprofloxacin and fluconazole,by the checkerboard method.Results:Thirty molecules were identified in the essential oil,comprising 96.27%of the total oil composition.Monoterpenes such as carvacrol(36.06%)were the most abundant compounds,followed by caryophyllene(14.67%),endo-borneol(9.04%),pyroterebic acid(3.23%)and caryophyllene oxide(3.13%).The oil exhibited a moderate antimicrobial activity with inhibition zone diameters ranging from 9.0 to 15.0 mm.The minimum inhibitory concentration values varied between 0.9 and 14.7 mg/mL,and Bacillus subtilis and Escherichia coli were the more sensitive bacteria with 0.9 and 1.9 mg/mL,respectively.The minimum microbicidal concentration values ranged from 0.4 to 14.7 mg/mL.A significant synergic action was observed when the oil was applied in combination with ciprofloxacin and fluconazole,with fractional inhibitory concentration index values ranging from 0.31 to 0.50.Synergy was found in 80%of the combinations and a 2 to 16-fold reduction of antibiotics MIC was observed.Conclusions:Our findings suggest that the essential oil of Centroceras clavulatum should be further appraised for its potential use in the management of multi-drug resistant microorganisms,with the purpose to restore the activity of standard antimicrobial drugs.