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Bromine, iodine and sodium along the EAIIST traverse: Bulk and surface snow latitudinal variability.Environmental Research Dec 2023During the East Antarctic International Ice Sheet Traverse (Eaiist, december 2019), in an unexplored part of the East Antarctic Plateau, snow samples were collected to...
During the East Antarctic International Ice Sheet Traverse (Eaiist, december 2019), in an unexplored part of the East Antarctic Plateau, snow samples were collected to expand our knowledge of the latitudinal variability of iodine, bromine and sodium as well as their relation in connection with emission processes and photochemical activation in this unexplored area. A total of 32 surface (0-5 cm) and 32 bulk (average of 1 m depth) samples were taken and analysed by Inductively Coupled Plasma Mass Spectrometry (ICP-MS). Our results show that there is no relevant latitudinal trend for bromine and sodium. For bromine they also show that it has no significant post-depositional mechanisms while its inland surface snow concentration is influenced by spring coastal bromine explosions. Iodine concentrations are several orders of magnitude lower than bromine and sodium and they show a decreasing trend in the surface samples concentration moving southward. This suggests that other processes affect its accumulation in surface snow, probably related to the radial reduction in the ozone layer moving towards central Antarctica. Even though all iodine, bromine and sodium present similar long-range transport from the dominant coastal Antarctic sources, the annual seasonal cycle of the ozone hole over Antarctica increases the amount of UV radiation (in the 280-320 nm range) reaching the surface, thereby affecting the surface snow photoactivation of iodine. A comparison between the bulk and surface samples supports the conclusion that iodine undergoes spring and summer snow recycling that increases its atmospheric lifetime, while it tends to accumulate during the winter months when photochemistry ceases.
Topics: Iodine; Bromine; Snow; Sodium; Antarctic Regions
PubMed: 37821067
DOI: 10.1016/j.envres.2023.117344 -
Annals of the New York Academy of... Jun 2016Bromine (Br2 ) gas inhalation poses an environmental and occupational hazard resulting in high morbidity and mortality. In this review, we underline the acute lung... (Review)
Review
Bromine (Br2 ) gas inhalation poses an environmental and occupational hazard resulting in high morbidity and mortality. In this review, we underline the acute lung pathology (within 24 h of exposure) and potential therapeutic interventions that may be utilized to mitigate Br2 -induced human toxicity. We discuss our latest published data, which suggest that an increase in heme-dependent tissue injury underlies the pathogenesis of Br2 toxicity. Our study was based on previous findings that demonstrated that Br2 upregulates the heme-degrading enzyme heme oxygenase-1 (HO-1), which converts toxic heme into bilverdin. Interestingly, following Br2 inhalation, heme levels were indeed elevated in bronchoalveolar lavage fluid, plasma, and whole lung tissue in C57BL/6 mice. High heme levels correlated with increased lung oxidative stress, lung inflammation, respiratory acidosis, lung edema, higher airway resistance, and mortality. However, therapeutic reduction of heme levels, by either scavenging with hemopexin or degradation by HO-1, improved lung function and survival. Therefore, heme attenuation may prove a useful adjuvant therapy to treat patients after Br2 exposure.
Topics: Animals; Bromine; Heme; Humans; Inhalation Exposure; Lung Injury; Models, Biological; Public Health
PubMed: 27244263
DOI: 10.1111/nyas.13086 -
Molecules (Basel, Switzerland) Dec 2022Halogenation of 2-trifluoromethylindole afforded 3-chloro-, 3-bromo- and 3-iodo derivatives in up to 98% yield. Methyl-, benzyl- and tosyl-groups can be installed at the...
Halogenation of 2-trifluoromethylindole afforded 3-chloro-, 3-bromo- and 3-iodo derivatives in up to 98% yield. Methyl-, benzyl- and tosyl-groups can be installed at the nitrogen atom of prepared indoles in high yields by base catalyzed reaction with the corresponding alkylating (sulfonylating) reagents. A high synthetic utility of the prepared haloindoles in the reaction with various nucleophilies was shown. The reaction with 4-methylthiophenol and copper cyanide afforded the corresponding sulfides and nitriles in high yield. Palladium catalyzed cross-coupling with phenyl boronic acid and phenylacetylene gave the corresponding 3-phenyl-2-CF-indoles and acetylenic derivatives in 72-98% yield.
Topics: Indoles; Catalysis; Cyanides; Nitriles; Halogenation; Palladium
PubMed: 36557954
DOI: 10.3390/molecules27248822 -
Proceedings of the National Academy of... Jul 2020Bromine and peroxidasin (an extracellular peroxidase) are essential for generating sulfilimine cross-links between a methionine and a hydroxylysine within collagen IV, a...
Bromine and peroxidasin (an extracellular peroxidase) are essential for generating sulfilimine cross-links between a methionine and a hydroxylysine within collagen IV, a basement membrane protein. The sulfilimine cross-links increase the structural integrity of basement membranes. The formation of sulfilimine cross-links depends on the ability of peroxidasin to use bromide and hydrogen peroxide substrates to produce hypobromous acid (HOBr). Once a sulfilimine cross-link is created, bromide is released into the extracellular space and becomes available for reutilization. Whether the HOBr generated by peroxidasin is used very selectively for creating sulfilimine cross-links or whether it also causes oxidative damage to bystander molecules (e.g., generating bromotyrosine residues in basement membrane proteins) is unclear. To examine this issue, we used nanoscale secondary ion mass spectrometry (NanoSIMS) imaging to define the distribution of bromine in mammalian tissues. We observed striking enrichment of bromine (Br, Br) in basement membranes of normal human and mouse kidneys. In peroxidasin knockout mice, bromine enrichment of basement membranes of kidneys was reduced by ∼85%. Proteomic studies revealed bromination of tyrosine-1485 in the NC1 domain of α2 collagen IV from kidneys of wild-type mice; the same tyrosine was brominated in collagen IV from human kidney. Bromination of tyrosine-1485 was reduced by >90% in kidneys of peroxidasin knockout mice. Thus, in addition to promoting sulfilimine cross-links in collagen IV, peroxidasin can also brominate a bystander tyrosine. Also, the fact that bromine enrichment is largely confined to basement membranes implies that peroxidasin activity is largely restricted to basement membranes in mammalian tissues.
Topics: Animals; Basement Membrane; Biopsy; Bromates; Bromides; Bromine; Cells, Cultured; Collagen Type IV; Extracellular Matrix Proteins; Humans; Hydrogen Peroxide; Imines; Kidney; Mice; Mice, Inbred C57BL; Mice, Knockout; Peroxidase; Proteomics; Peroxidasin
PubMed: 32571911
DOI: 10.1073/pnas.2007749117 -
Molecules (Basel, Switzerland) May 2022Limonene (1-methyl-4-(1-methylethenyl)-cyclohexene) is one of the most widespread monocyclic terpenes, being both a natural and industrial compound. It is widely present...
Limonene (1-methyl-4-(1-methylethenyl)-cyclohexene) is one of the most widespread monocyclic terpenes, being both a natural and industrial compound. It is widely present in the environment, including in water supplies. Therefore, it may be subjected to aqueous chlorination at water treatment stations during drinking water preparation. Besides, being a component of numerous body care and cosmetic products, it may present at high levels in swimming pool waters and could also be subjected to aqueous chlorination. Laboratory experiments with aqueous chlorination of D-limonene demonstrated the prevalence of the conjugated electrophilic addition of HOCl molecule to the double bonds of the parent molecule as the primary reaction. The reaction obeys the Markovnikov rule, as the levels of the corresponding products were higher than those of the alternative ones. Fragmentation pattern in conditions of electron ionization enabled the assigning of the structures for four primary products. The major products of the chlorination are formed by the addition of two HOCl molecules to limonene. The reactions of electrophilic addition are usually accompanied by the reactions of elimination. Thus, the loss of water molecules from the products of various generations results in the reproduction of the double bond, which immediately reacts further. Thus, a cascade of addition-elimination reactions brings the most various isomeric polychlorinated species. At a ratio of limonene/active chlorine higher than 1:10, the final products of aqueous chlorination (haloforms) start forming, while brominated haloforms represent a notable portion of these products due to the presence of bromine impurities in the used NaOCl. It is worth mentioning that the bulk products of aqueous chlorination are less toxic in the bioluminescence test on than the parent limonene.
Topics: Chlorine; Disinfection; Halogenation; Limonene; Water Pollutants, Chemical; Water Purification
PubMed: 35566337
DOI: 10.3390/molecules27092988 -
International Journal of Molecular... Jun 2021The risk of accidental bromine (Br) exposure to the public has increased due to its enhanced industrial use. Inhaled Br damages the lungs and the heart; however, adverse...
The risk of accidental bromine (Br) exposure to the public has increased due to its enhanced industrial use. Inhaled Br damages the lungs and the heart; however, adverse effects on the brain are unknown. In this study, we examined the neurological effects of inhaled Br in Sprague Dawley rats. Rats were exposed to Br (600 ppm for 45 min) and transferred to room air and cage behavior, and levels of glial fibrillary acidic protein (GFAP) in plasma were examined at various time intervals. Bromine exposure resulted in abnormal cage behavior such as head hitting, biting and aggression, hypervigilance, and hyperactivity. An increase in plasma GFAP and brain 4-hydroxynonenal (4-HNE) content also was observed in the exposed animals. Acute and delayed sympathetic nervous system activation was also evaluated by assessing the expression of catecholamine biosynthesizing enzymes, tryptophan hydroxylase (TrpH1 and TrpH2), and tyrosine hydroxylase (TyrH), along with an assessment of catecholamines and their metabolites. TyrH was found to be increased in a time-dependent manner. TrpH1 and TrpH2 were significantly decreased upon Br exposure in the brainstem. The neurotransmitter content evaluation indicated an increase in 5-HT and dopamine at early timepoints after exposure; however, other metabolites were not significantly altered. Taken together, our results predict brain damage and autonomic dysfunction upon Br exposure.
Topics: Administration, Inhalation; Animals; Behavior, Animal; Biomarkers; Brain Injuries; Brain Stem; Bromine; Catecholamines; Female; Glial Fibrillary Acidic Protein; Metabolome; Neurons; Neurotransmitter Agents; Oxidative Stress; Rats, Sprague-Dawley; Tryptophan Hydroxylase; Tyrosine 3-Monooxygenase; Rats
PubMed: 34204780
DOI: 10.3390/ijms22126316 -
American Journal of Physiology. Heart... Jan 2019Halogens are widely used, highly toxic chemicals that pose a potential threat to humans because of their abundance. Halogens such as bromine (Br) cause severe pulmonary...
Halogens are widely used, highly toxic chemicals that pose a potential threat to humans because of their abundance. Halogens such as bromine (Br) cause severe pulmonary and systemic injuries; however, the mechanisms of their toxicity are largely unknown. Here, we demonstrated that Br and reactive brominated species produced in the lung and released in blood reach the heart and cause acute cardiac ultrastructural damage and dysfunction in rats. Br-induced cardiac damage was demonstrated by acute (3-24 h) increases in circulating troponin I, heart-type fatty acid-binding protein, and NH-terminal pro-brain natriuretic peptide. Transmission electron microscopy demonstrated acute (3-24 h) cardiac contraction band necrosis, disruption of z-disks, and mitochondrial swelling and disorganization. Echocardiography and hemodynamic analysis revealed left ventricular (LV) systolic and diastolic dysfunction at 7 days. Plasma and LV tissue had increased levels of brominated fatty acids. 2-Bromohexadecanal (Br-HDA) injected into the LV cavity of a normal rat caused acute LV enlargement with extensive disruption of the sarcomeric architecture and mitochondrial damage. There was extensive infiltration of neutrophils and increased myeloperoxidase levels in the hearts of Br or Br reactant-exposed rats. Increased bromination of sarco(endo)plasmic reticulum Ca-ATPase (SERCA) and increased phosphalamban after Br inhalation decreased cardiac SERCA activity by 70%. SERCA inactivation was accompanied by increased Ca-sensitive LV calpain activity. The calpain-specific inhibitor MDL28170 administered within 1 h after exposure significantly decreased calpain activity and acute mortality. Bromine inhalation and formation of reactive brominated species caused acute cardiac injury and myocardial damage that can lead to heart failure. NEW & NOTEWORTHY The present study defines left ventricular systolic and diastolic dysfunction due to cardiac injury after bromine (Br) inhalation. A calpain-dependent mechanism was identified as a potential mediator of cardiac ultrastructure damage. This study not only highlights the importance of monitoring acute cardiac symptoms in victims of Br exposure but also defines calpains as a potential target to treat Br-induced toxicity.
Topics: Administration, Inhalation; Animals; Biomarkers; Bromine; Calpain; Cells, Cultured; Hemodynamics; Male; Mitochondria, Heart; Myocardial Contraction; Myocardial Reperfusion Injury; Myocytes, Cardiac; Rats; Rats, Sprague-Dawley; Sarcoplasmic Reticulum Calcium-Transporting ATPases; Ventricular Dysfunction; Ventricular Remodeling
PubMed: 30379573
DOI: 10.1152/ajpheart.00652.2017 -
British Medical Journal Mar 1957
Topics: Bromine; Humans; Hypnotics and Sedatives
PubMed: 13404236
DOI: 10.1136/bmj.1.5018.565 -
Public Health Reports (Washington, D.C.... Jun 1959
Topics: Fluoridation; Halogenation; Humans
PubMed: 13658341
DOI: No ID Found -
Biomolecules Dec 2022Halogenation of bioactive peptides via incorporation of non-natural amino acid derivatives during chemical synthesis is a common strategy to enhance functionality....
Halogenation of bioactive peptides via incorporation of non-natural amino acid derivatives during chemical synthesis is a common strategy to enhance functionality. Bacterial tyrptophan halogenases efficiently catalyze regiospecific halogenation of the free amino acid tryptophan, both in vitro and in vivo. Expansion of their substrate scope to peptides and proteins would facilitate highly-regulated post-synthesis/expression halogenation. Here, we demonstrate novel in vitro halogenation (chlorination and bromination) of peptides by select halogenase enzymes and identify the C-terminal (G/S)GW motif as a preferred substrate. In a first proof-of-principle experiment, we also demonstrate chemo-catalyzed derivatization of an enzymatically chlorinated peptide, albeit with low efficiency. We further rationally derive PyrH halogenase mutants showing improved halogenation of the (G/S)GW motif, both as a free peptide and when genetically fused to model proteins with efficiencies up to 90%.
Topics: Halogenation; Oxidoreductases; Bacterial Proteins; Peptides; Amino Acids
PubMed: 36551269
DOI: 10.3390/biom12121841