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Methyl bromide (MB) is a potent fumigant used to control pests in soil and agricultural products. As an ozone-depleting substance, MB has been largely replaced by safer alternatives. MB is highly toxic to humans and has been shown to adversely affect asymptomatic workers’ central and autonomic nervous systems and vascular health. However, its impact on perceptual and cognitive abilities remains underexplored. In this study, we examined the effects of MB exposure on cognitive functions in asymptomatic workers. Event-related potential (ERP) indices, which reflect perceptual and cognitive processes, and urinary bromide ion (Br - ) concentrations were assessed in 32 fumigators (study group) and 18 inspectors (control group) before and after fumigation. Post-work ERP latency and amplitude changes in inspectors were significant ( P  < 0.01), similar to those observed in healthy individuals. In contrast, ERP changes in fumigators were not significant compared to pre-work values; this suggests that MB negatively impacts cognitive health. Additionally, Br ‑ levels in fumigators rose sharply after work ( P  < 0.001), while inspectors showed no such increase. The elevated Br - levels and nonenhanced ERP indices in fumigators after MB exposure indicate adverse health effects despite the absence of symptoms.

Marine algae contain various bromophenols that have been shown to possess a variety of biological activities, including antiradical, antimicrobial, anticancer, antidiabetic, anti-inflammatory effects, and so on. Here, we briefly review the recent progress of these marine algae biomaterials and their derivatives from 2011 to 2020, with respect to structure, bioactivities, and their potential application as pharmaceuticals.

Fluorinated organic compounds are becoming increasingly important in pharmaceuticals, agrochemicals and materials science. The introduction of trifluoromethoxy groups into new drugs and agrochemicals has attracted much attention due to their strongly electron-withdrawing nature and high lipophilicity. However, synthesis of trifluoromethoxylated organic molecules is difficult owing to the decomposition of trifluoromethoxide anion and β-fluoride elimination from transition-metal–trifluoromethoxide complexes, and no catalytic enantioselective trifluoromethoxylation reaction has been reported until now. Here, we present an example of an asymmetric silver-catalysed intermolecular bromotrifluoromethoxylation of alkenes with trifluoromethyl arylsulfonate (TFMS) as a new trifluoromethoxylation reagent. Compared to other trifluoromethoxylation reagents, TFMS is easily prepared and thermally stable with good reactivity. In addition, this reaction is operationally simple, scalable and proceeds under mild reaction conditions. Furthermore, broad scope and good functional group compatibility has been demonstrated by application of the method to the bromotrifluoromethoxylation of double bonds in natural products and natural product derivatives. The first example of an asymmetric silver-catalysed intermolecular bromotrifluoromethoxylation of alkenes has been described with trifluoromethyl aryl sulfonate as a new trifluoromethoxylation reagent. This reaction is operationally simple, scalable and proceeds under mild reaction conditions, which can be applied to the late-stage trifluoromethoxylation of complex small molecules.

Pro-inflammatory cytokines, like interleukin-1 beta and interferon gamma, are known to activate signalling pathways causing pancreatic beta cell death and dysfunction, contributing to the onset of diabetes. Targeting cytokine signalling pathways offers a potential strategy to slow or even halt disease progression, reducing reliance on exogenous insulin and improving glucose regulation. This study explores the protective and proliferative effects of breitfussin C (BfC), a natural compound isolated from the Arctic marine hydrozoan Thuiaria breitfussi , on pancreatic beta cells exposed to pro-inflammatory cytokines. Using the beta cell line RIN-M5F, we assessed the protective effects of BfC through a MTS assay for cell viability, caspase 3/7 activity for apoptosis, and EdU incorporation and cell cycle distribution for proliferation. Additionally, we investigated BfC’s inhibitory effects on the DYRK family of kinases using kinase activity and binding assays, western blotting, and docking simulations. Our findings reveal that BfC treatment effectively increases beta cell proliferation and counteracts cytokine-induced decrease in proliferation. The proliferative effect is associated with inhibition of DYRK kinases and a subsequent decrease in the cell cycle inhibitor p27 KIP . These results suggest that BfC mediates beta cell-protective effect by promoting proliferation through DYRK inhibition, highlighting its potential as a molecular starting point for the development of a therapeutic agent against diabetes.

Side population (SP) cells within tumors are a small fraction of cancer cells with stem-like properties that can be identified by flow cytometry analysis based on their high ability to export certain compounds such as Hoechst 33342 and chemotherapeutic agents. The existence of stem-like SP cells in tumors is considered as a key factor contributing to drug resistance, and presents a major challenge in cancer treatment. Although it has been recognized for some time that tumor tissue niches may significantly affect cancer stem cells (CSCs), the role of key nutrients such as glucose in the microenvironment in affecting stem-like cancer cells and their metabolism largely remains elusive. Here we report that SP cells isolated from human cancer cells exhibit higher glycolytic activity compared to non-SP cells. Glucose in the culture environment exerts a profound effect on SP cells as evidenced by its ability to induce a significant increase in the percentage of SP cells in the overall cancer cell population, and glucose starvation causes a rapid depletion of SP cells. Mechanistically, glucose upregulates the SP fraction through ATP-mediated suppression of AMPK and activation of the Akt pathway, leading to elevated expression of the ATP-dependent efflux pump ABCG2. Importantly, inhibition of glycolysis by 3-BrOP significantly reduces SP cells in vitro and impairs their ability to form tumors in vivo . Our data suggest that glucose is an essential regulator of SP cells mediated by the Akt pathway, and targeting glycolysis may eliminate the drug-resistant SP cells with potentially significant benefits in cancer treatment.

Methyl bromide (MeBr) is a chemically reactive compound that has found use as a fire retardant and fumigant used for wood, soil, fruits and grains. Its use is banned in many countries because of its ozone-depleting properties. Despite this ban, the use of MeBr persists in some parts of the world (e.g. New Zealand) due to its important role in maintaining strict biosecurity of exported and imported products. Its high chemical reactivity leads to a broad toxicological profile ranging from acute respiratory toxicity following inhalation exposure, through carcinogenicity to neurotoxicty. In this article, we discuss the chemistry of MeBr in the context of its mechanisms of toxicity. The chemical reactivity of MeBr clearly underlies its toxicity. Bromine (Br) is electronegative and a good leaving group; the δ+ carbon thus facilitates electrophilic methylation of biological molecules including glutathione (GSH) via its δ− sulphur atom, leading to downstream effects due to GSH depletion. DNA alkylation, either directly by MeBr or indirectly due to reduction in GSH-mediated detoxification of reactive alkylating chemical species, might explain the carcinogenicity of MeBr. The neurotoxicity of MeBr is much more difficult to understand, but we speculate that methyl phosphates formed in cells might contribute to its neurone-specific toxicity via cholinesterase inhibition. Finally, evidence reviewed shows that it is unlikely for Br− liberated by the metabolism of MeBr to have any toxicological effect because the Br− dose is very low.

1-Bromopropane, an alternative to ozone-depleting solvents, exhibits neurotoxicity in humans and rats. The aim of the present study was to identify the genes or signaling pathways involved in the neurotoxicity and hepatotoxicity of 1-bomopropane in two inbred strains of rats. F344 rats and WNA/NUM rats were exposed to 1-bromopropane or filtered air by inhalation for either a single 8-hour session, or 8 h daily for 4 weeks. Motor nerve conduction velocity and distal latency were measured in the tail. At the end of the experiment, the animals were decapitated, and the hippocampus, liver, and blood were collected. Exposure to 1-bromopropane for 4 weeks increased distal latency in the tail nerve significantly in F344 and marginally in WNA/NUM. It also increased total and direct bilirubin in both rat strains. Eight-hour exposure increased metallothionein 2A, metallothionein 1 and NAD(P)H quinone dehydrogenase 1 expression in the liver of both rat strains, whereas 4-week exposure upregulated glutathione S-transferase alpha 3 and CD36 molecule in the liver of both strains. KEGG analysis showed that 8-hr 1-bromopropane upregulated pathways of apoptosis, NOD-like receptor signaling and colorectal cancer, in both the hippocampus and liver, whereas 4-week exposure upregulated NOD-like receptor signaling pathway both in the hippocampus and liver of the two rat strains. Insulin signaling pathway was upregulated persistently in the hippocampus of the two rat strains. Our results suggest the involvement of immune system/inflammation-related pathway in the neuro- and hepato-toxicity of 1-bromopropane and the involvement of insulin signaling pathway in the neurotoxicity of 1-brromopropane.

The expectation that antimony (Sb) compounds should display phosphorescence emissions based on the “heavy element effect” prompted our interest in the introduction of antimony to a biaryl as the bridging atom in a fused heterole system. Herein, the synthesis, molecular structures, and optical properties of novel benzene-fused heteroacenes containing antimony or arsenic atoms are described. The stiboles and arsole were prepared by the condensation of dibromo(phenyl)stibane or dichloro(phenyl)arsine with dilithium intermediates derived from the corresponding dibromo compounds. Nuclear magnetic resonance (NMR) spectroscopy and X-ray crystal analysis revealed that the linear pentacyclic stibole was highly symmetric in both the solution and crystal states. In contrast, the curved pentacyclic stibole adopted a helical structure in solution, and surprisingly, only M helical molecules were crystallized from the racemate. All synthesized compounds produced very weak or no emissions at room temperature or in the solid state. In contrast, the linear penta- and tetracyclic stiboles exhibited clear phosphorescence emissions in the CHCl3 frozen matrix at 77 K under aerobic conditions.

Naturally occurring three-dimensional (3D) biopolymer-based matrices that can be used in different biomedical applications are sustainable alternatives to various artificial 3D materials. For this purpose, chitin-based structures from marine sponges are very promising substitutes. Marine sponges from the order Verongiida (class Demospongiae) are typical examples of demosponges with well-developed chitinous skeletons. In particular, species belonging to the family Ianthellidae possess chitinous, flat, fan-like fibrous skeletons with a unique, microporous 3D architecture that makes them particularly interesting for applications. In this work, we focus our attention on the demosponge Ianthella flabelliformis (Linnaeus, 1759) for simultaneous extraction of both naturally occurring (“ready-to-use”) chitin scaffolds, and biologically active bromotyrosines which are recognized as potential antibiotic, antitumor, and marine antifouling substances. We show that selected bromotyrosines are located within pigmental cells which, however, are localized within chitinous skeletal fibers of I. flabelliformis. A two-step reaction provides two products: treatment with methanol extracts the bromotyrosine compounds bastadin 25 and araplysillin-I N20 sulfamate, and a subsequent treatment with acetic acid and sodium hydroxide exposes the 3D chitinous scaffold. This scaffold is a mesh-like structure, which retains its capillary network, and its use as a potential drug delivery biomaterial was examined for the first time. The results demonstrate that sponge-derived chitin scaffolds, impregnated with decamethoxine, effectively inhibit growth of the human pathogen Staphylococcus aureus in an agar diffusion assay.

Bromophenols are a class of compounds occurring in red algae that are thought to play a role in chemical protection; however, their exact function is still not fully known. In order to investigate their occurrence, pure standards of seven bromophenols were isolated from a methanolic extract of the epiphytic red alga Vertebrata lanosa collected in Brittany, France. The structures of all compounds were determined by NMR and MS. Among the isolated substances, one new natural product, namely, 2-amino-5-(3-(2,3-dibromo-4,5-dihydroxybenzyl)ureido)pentanoic acid was identified. An HPLC method for the separation of all isolated substances was developed using a Phenomenex C8(2) Luna column and a mobile phase comprising 0.05% trifluoroacetic acid in water and acetonitrile. Method validation showed that the applied procedure is selective, linear (R2 ≥ 0.999), precise (intra-day ≤ 6.28%, inter-day ≤ 5.21%), and accurate (with maximum displacement values of 4.93% for the high spikes, 4.80% for the medium spikes, and 4.30% for the low spikes). For all standards limits of detection (LOD) were lower than 0.04 μg/mL and limits of quantification (LOQ) lower than 0.12 μg/mL. Subsequently, the method was applied to determine the bromophenol content in Vertebrata lanosa samples from varying sampling sites and collection years showing values between 0.678 and 0.005 mg/g dry weight for different bromophenols with significant variations between the sampling years. Bioactivity of seven isolated bromophenols was tested in agar diffusion tests against Staphylococcus aureus and Escherichia coli bacteria. Three compounds showed a small zone of inhibition against both test organisms at a concentration of 100 µg/mL.