Discovery of Anti-Hypercholesterolemia Agents Targeting LXRα from Marine Microorganism-Derived Natural Products.

A strategy integrating molecular docking with LXRα and phenotypic assays was adopted to discover anti-hypercholesterolemia agents in a small library containing 205 marine microorganism-derived natural products, collected by our group in recent years. Two fumitremorgin derivatives, 12,13-dihydroxyfumitremorgin C () and tryprostatin A (), were identified as potential LXRα agonists, by real-time qPCR and Western blot (WB) analysis, together with a surface plasmon resonance (SPR) assay. The anti-hypercholesterolemic effects of and , together with their mechanisms, were investigated in depth using different cell and mouse models, among which the study of LXRα is of crucial importance.

Organophosphate flame retardants and their metabolites in the Pearl River Estuary: Occurrence, influencing factors, and ecological risk control strategies based on a mass balance model.

Estuaries serve as crucial filters for land-based pollutants to the open sea, but there is a lack of information on the migration and fate of organophosphate flame retardants (OPFRs) within estuaries. This study focused on the Pearl River Estuary (PRE) by examining the co-occurrence of OPFRs and their metabolites and quantifying their transport fluxes using a mass balance model. The seawater concentrations of OPFRs and their metabolites exhibited significant seasonal variations (p < 0.

Labyrinthulomycetes thrives in organic matter-rich waters with ecological partitioning in the Pearl River Estuary.

Labyrinthulomycetes play an important role in marine biogeochemical cycles, but their diversity, distribution patterns, and key regulatory factors remain unclear. This study measured the abundance and diversity of Labyrinthulomycetes in the Pearl River Estuary (PRE) to understand its distribution pattern and relationship with environmental and biological factors. The abundance of Labyrinthulomycetes ranged from 24 to 500 cells·mL, with an average of 144.

Study of selenium enrichment metabolomics in Bacillus subtilis BSN313 via transcriptome analysis.

In this study, the transcriptome analysis was practiced to identify potential genes of probiotic Bacillus subtilis BSN313 involved in selenium (Se) enrichment metabolism. The transcriptomic variation of the strain was deliberated in presence of three different sodium selenite concentrations (0, 3, and 20 μg/mL). The samples were taken at 1 and 13 h subsequent to inoculation of selenite and gene expression profiles in Se metabolism were analyzed through RNA sequencing.

Estuarine hydrodynamic processes driving the molecular changes of terrestrial dissolved organic nitrogen: From mixing to biological modification.

Estuaries receive substantial amounts of terrestrial dissolved organic nitrogen (tDON), which will be transported from the freshwater to the oceanic terminus through vigorous exchange processes. However, the intricate migration and transformation dynamics of tDON during this transportation, particularly at a molecular level, remain constrained. To address this knowledge gap, Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) was used for the analysis of DON molecular composition in the Pearl River Estuary (PRE), a river-dominated estuarine system influenced by intensified anthropogenic activities in southern China.

Identifying Marine-Derived Tanzawaic Acid Derivatives as Novel Inhibitors against Osteoclastogenesis and Osteoporosis via Downregulation of NF-κB and NFATc1 Activation.

To discover novel osteoclast-targeting antiosteoporosis leads from natural products, we identified 40 tanzawaic acid derivatives, including 22 new ones (-, -, -, , and ), from the South China Sea mangrove-derived fungus SCSIO 41025. Penicisteck acid F (), one of the new derivatives showing the most potent NF-κB inhibitory activity, remarkably inhibited osteoclast generation . Mechanistically, reduced RANKL-induced IκBα degradation, NF-κB p65 nuclear translocation, the activation and nuclear translocation of NFATc1, and the relevant mRNA expression.

Expanding the Chemical Diversity of Grisechelins via Heterologous Expression.

Thiazole scaffold-based small molecules exhibit a range of biological activities and play important roles in drug discovery. Based on bioinformatics analysis, a putative biosynthetic gene cluster (BGC) for thiazole-containing compounds was identified from sp. SCSIO 40020.

Discovery of Artemisinins as Microsomal Prostaglandins Synthase-2 Inhibitors for the Treatment of Colorectal Cancer via Chemoproteomics.

Colorectal cancer remains the second leading cause of cancer-related mortalities worldwide. While artemisinin (ART), a key active compound from the traditional Chinese medicinal herb , has been recognized for its antiproliferative activity against colon cancer cells, its underlying molecular underpinnings remain elusive. Whereas promiscuity of heme-dependent alkylating of macromolecules, mainly proteins, has been seen pivotal as a universal and primary mode of action of ART in cancer cells, accumulating evidence suggests the existence of unique targets and mechanisms of actions contingent on cell or tissue specificities.

Rolling with the punches: Organism-environment interactions shape spatial pattern of adaptive differentiation in the widespread mantis shrimp Oratosquilla oratoria.

Investigating spatial pattern of adaptive variation and its underlying processes can inform the adaptive potential distributed within species ranges, which is increasingly important in the context of a changing climate. A correct interpretation of adaptive variation pattern requires that population history and the ensuing population genetic structure are taken into account. Here we carried out such a study by integrating population genomic analyses, demographic model testing and species distribution modeling to investigate patterns and causes of adaptive differentiation in a widespread mantis shrimp, Oratosquilla oratoria, along a replicated, broad-scale temperature gradient in the northwestern Pacific (NWP).

Anthropogenic multipollutant input to the offshore South China Sea.

The remote region of the South China Sea (SCS), situated far from urban mainland areas, is commonly perceived to experience minimal pollution. However, this may evolve into a considerably polluted region owing to increasing anthropogenic pollutants. In this study, we employ a multidisciplinary approach to analyze the surface sediments collected from the offshore area of the southern SCS.

Polyethylene Terephthalate Hydrolases in Human Gut Microbiota and Their Implications for Human Health.

Polyethylene terephthalate (PET), primarily utilized for food and beverage packaging, consistently finds its way into the human gut, thereby exerting adverse effects on human health. PET hydrolases, critical for the degradation of PET, have been predominantly sourced from environmental microbial communities. Given the fact that the human gut harbors a vast and intricate consortium of microorganisms, inquiry into the presence of potential PET hydrolases within the human gut microbiota becomes imperative.

A new phenylspirodrimane derivative from the deep-sea-derived fungus FS705.

A new phenylspirodrimane derivative named stachybotrysin A (), together with four known analogues (-) were isolated and purified from the solid culture of the deep-sea-derived FS705. Their structures were determined by comprehensive spectroscopic analysis and the absolute configuration was evaluated by theoretical ECD calculations. Compounds - were evaluated for their cytotoxic, antibacterial and -glucosidase inhibitory activities.

Deciphering the Glycosylation Steps in the Biosynthesis of P-1894B and Grincamycin Isolated from Marine-Derived SCSIO LR32.

Recently, we re-isolated the glycosylated angucycline antibiotics P-1894B () and grincamycin () from the marine-derived SCSIO LR32 as potent antitumor agents and identified their biosynthesis gene cluster . Both P-1894B () and grincamycin () possess a trisaccharide and a disaccharide moiety comprised of five deoxysugars. In this work, three genes encoding glycosyltransferases (GcnG1, GcnG2, and GcnG3) responsible for the assembly of deoxysugars into angucycline aglycone were identified from the biosynthesis gene cluster .

OSMAC-Based Discovery and Biosynthetic Gene Clusters Analysis of Secondary Metabolites from Marine-Derived SCSIO LCY30.

The one strain many compounds (OSMAC) strategy is an effective method for activating silent gene clusters by cultivating microorganisms under various conditions. The whole genome sequence of the marine-derived strain SCSIO LCY30 revealed that it contains 30 biosynthetic gene clusters (BGCs). By using the OSMAC strategy, three types of secondary metabolites were activated and identified, including three angucyclines, mayamycin A (), mayamycin B (), and rabolemycin (); two streptophenazines (streptophenazin O () and M ()); and a macrolide dimeric dinactin (), respectively.

Two New Isocoumarins Isolated from the Marine-Sponge-Derived Fungus Setosphaeria sp. SCSIO41009.

Two new dihydroisocoumarins, exserolides L and M (1 and 2), along with six known compounds (3-8) were isolated from the extract of the marine-sponge-derived fungus Setosphaeria sp. SCSIO41009. Their structures were established by spectroscopic analyses.

gen. nov., sp. nov., a new member of the family , isolated from a marine sediment of the South China Sea.

A Gram-stain-negative, catalase-positive and oxidase-positive, nonmotile, aerobic, light yellow, spherical-shaped bacterial strain with no flagella, designated strain YIM 152171, was isolated from sediment of the South China Sea. Colonies were smooth and convex, light yellow and circular, and 1.0-1.

Administration of Gracilariopsis lemaneiformis polysaccharide attenuates cisplatin-induced inflammation and intestinal mucosal damage in colon-26 carcinoma tumor-bearing mice.

Background: Our preliminary research revealed that the polysaccharide GP90 from Gracilariopsis lemaneiformis enhanced the antitumor effect of cisplatin, indicating that GP90 may increase the chemotherapeutic sensitivity. However, it is still necessary to fully understand whether GP90 can also improve the intestinal barrier dysfunction and systemic inflammation induced by cisplatin.

Results: GP90 has been demonstrated to inhibit the excessive release of nitirc oxide, interleukin (IL)-6, IL-1β and tumor necrosis factor (TNF)-α induced by lipopolysaccharide in RAW264.

Efficient biological carbon export to the mesopelagic ocean induced by submesoscale fronts.

Oceanic submesoscale processes are ubiquitous in the North Pacific Subtropical Gyre (NPSG), where the biological carbon pump is generally ineffective. Due to difficulties in collecting continuous observations, however, it remains uncertain whether episodic submesoscale processes can drive significant changes in particulate organic carbon (POC) export into the mesopelagic ocean. Here we present observations from high-frequency Biogeochemical-Argo floats in the NPSG, which captured the enhanced POC export fluxes during the intensifying stages of a submesoscale front and a cyclonic eddy compared to their other life stages.

Semi-synthesis and structure-activity relationship study yield antibacterial vicenistatin derivatives with low cytotoxicity.

Vicenistatin (1) is a 20-membered polyketide macrocyclic antibiotic with potent antimicrobial and cytotoxic activities. In this study, to further explore the potential of 1 as candidates of antibacterial drug development, 4'-N-demethyl vicenistatin (2), a secondary metabolite obtained from the ∆vicG mutant strain of Monodonata labio-associated Streptomyces parvus SCSIO Mla-L010, was utilized as a starting material for modifications of 4'-amino group of vicenistatin. Six new vicenistatin derivatives (3-8) were semi-synthesized through a concise route of amino modification with various aliphatic and aromatic aldehydes.

Outer membrane vesicles produced by coral-associated Vibrio coralliilyticus inhibit bacteriophage infection and its ecological implications.

The potential to produce and release outer membrane vesicles (OMVs) is evolutionarily conserved among bacteria, facilitating interactions between microbes. OMV release and its ecological significance have rarely been reported in coral holobionts. Here, via transmission electron microscopy (TEM), we discovered that the coral-associated strain Vibrio coralliilyticus DSM 19607 produced OMVs in culture.

Re-evaluation of the taxonomic status of four nominal, western Pacific species of tongue soles (Pleuronectoidei: Cynoglossidae: Cynoglossus), with redescription of C. joyneri Gnther, 1878.

Striking similarities in morphological characters and significant overlap in meristic features have resulted in different hypotheses regarding the taxonomic status of several nominal species of northwestern Pacific tongue soles of the genus Cynoglossus, including C. joyneri Gnther, 1878, C. lighti Norman, 1925, C.

Bacterial carbonic anhydrase-induced carbonates mitigate soil erosion in biological soil crusts.

Soil erosion is a significant environmental issue worldwide, particularly in island regions where land resources are exceedingly scarce. Biological soil crusts play a crucial role in mitigating soil erosion, yet the precise effect and mechanism of biological soil crusts against erosion remain ambiguous. In this study, biological soil crusts at various developmental stages from a tropical coral island in the South China Sea were chosen to investigate the role of carbonic anhydrase in mitigating erosion.

Meroterpenoids from the marine-derived fungus Aspergillus terreus GZU-31-1 exerts anti-liver fibrosis effects by targeting the Nrf2 signaling in vitro.

Six undescribed meroterpenoids aspertermeroterpenes A-F and four known analogues were isolated from the marine-derived fungus Aspergillus terreus GZU-31-1. Their structures were elucidated based on spectroscopic methods and electronic circular dichroism calculations. All meroterpenoids possessed the unique acetyl group at C-11, and also aspertermeroterpene A featured the rare C-14 decarboxylated in DMOA meroterpenoids.

Non-enzymatic synthesis of -methylated fluostatins: discovery and reaction mechanism.

Two -methylated fluostatins (FSTs) B3 (1) and B4 (2) were synthesized from flavin-mediated nonenzymatic epoxide ring-opening reactions of FST C. The structures of 1 and 2 were elucidated by HRESIMS, NMR, and ECD spectroscopic analyses. A subsequent C labeling study demonstrated that the -methyl groups of 1 and 2 were derived from DMSO and enabled the mechanistic proposal of a nonenzymatic -methylation.