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At least 19 recordsLinked to original sources
PubMed2002

A bromine compound existing in blood.

Since a bromine compound with REM-sleep-inducing and anti-choline esterase activities have been isolated from human cerebrospinal fluid, and was identified as 1-methylheptyl gamma-bromoacetoacetate, the compound was chemically synthesized. It was found that this compound was composed with three forms, i.e., a keto-form, an enol-form that changed gradually from keto-form by tautomerism, and a stable six-membered ring form (= cyclic r-Br) converted from enol form, when it was chemically synthesized. In addition, it was found that the six-membered ring form of this bromine compound was present in the human blood. However, in this case, the keto-form and the enol-form were not detected. When 14C-butyrate was injected to rats, it was incorporated into the bromine compound in the blood of the animal and the bromine compound formed was found to be present mainly as the six-membered ring form. From these results, the mechanism for the formation of bromine compounds in human and animal blood were deduced.

Acetoacetates↗
PubMed2001

A GC/ECNI-MS method for the identification of lipophilic anthropogenic and natural brominated compounds in marine samples.

GC/ECNI-MS in both the full scan and selected ion monitoring modes was applied to study the patterns of brominated compounds in the blubber of marine mammals from a variety of locations. The adipose tissue of one polar bear was also studied. Occurrence of three major residues originating from the use of brominated flame-retardants (PBDE 47, 99, and 100) and several potential naturally occurring brominated compounds was studied in the samples. A series of three major natural brominated compounds (BC-1, BC-2, BC-3) recently identified in dolphins from Australia was included in this study. Two further brominated compounds, BC-10 and BC-11, were studied for the first time. ECNI-MS full scan spectra were obtained for BC-3 and BC-10. A natural mixed halogenated compound (MHC-1) and an unknown brominated compound (UBC-1) were investigated as well. Evidence for the natural production of these secondary metabolites and their bioaccumulation in higher organisms as well as analytical protocols for their detection in the environment are presented. Some of these naturally occurring compounds may be misinterpreted as anthropogenic brominated compounds. In ECNI-MS, brominated compounds are usually identified by the detection of the fragment ions m/z 79 ([79Br]-) and m/z 81 ([81Br]-). In this work, it is shown that monitoring of additional ion traces corresponding to [Br2]- (160 type), [HBr2]- (161 type), [BrCl]- (116 type), and [HBrCl]- (117 type) fragment ions allows distinguishing between different classes of brominated compounds. This technique was used to demonstrate that UBC-1 is neither a PBDE nor a PBB congener, whereas a second mixed halogenated compound (MHC-2) was identified as a result of the ECNI-MS response at m/z 114/116. Studies on blubber extracts of marine mammals from four continents resulted in the detection of significant differences in the global distribution of brominated compounds. Our results suggest that naturally occurring organobromines are more abundant than anthropogenic brominated compounds in several regions of the world.

Adipose Tissue↗
PubMed2001

Antiangiogenic activity of aeroplysinin-1, a brominated compound isolated from a marine sponge.

(+)-aeroplysinin-1, an antibacterial brominated compound produced by certain sponges, was selected during a blind high-throughput screening for new potential antiangiogenic compounds obtained from marine organisms. In a variety of experimental systems, representing the sequential events of the angiogenic process, aeroplysinin-1 treatment of endothelial cells resulted in strong inhibitory effects. Aeroplysinin-1 inhibited the growth of endothelial cells in culture and induced endothelial cell apoptosis. Capillary tube formation on Matrigel was completely abrogated by addition of aeroplysinin-1 at the low micromolar range. Aeroplysinin-1 also exhibited a clear inhibitory effect on the migration capabilities of endothelial cells. Zymographic assays showed that aeroplysinin-1 treatment produced a decrease in the concentration of matrix metalloproteinase-2 and urokinase in conditioned medium from endothelial cells. Finally, aeroplysinin-1 exhibited a dose-dependent inhibitory effect on the in vivo chorioallantoic membrane assay, showing potent apoptosis-inducing activity in the developing endothelium. The in vivo inhibition of angiogenesis by aeroplysinin-1 was confirmed by the Matrigel plug assay. Together, our data indicate that aeroplysinin-1 is a compound that interferes with key events in angiogenesis, making it a promising drug for further evaluation in the treatment of angiogenesis-related pathologies.

Acetonitriles↗
PubMed2000

Distribution of brominated compounds within the sponge Aplysina aerophoba: coupling of X-ray microanalysis with cryofixation techniques.

The major secondary metabolites of the sponge Aplysina aerophoba are brominated compounds. X-ray energy dispersive microanalysis was therefore used to locate secondary metabolites via the Br signal in energy emission spectra from sponge sections. To test the reliability of this method in the face of the loss or redistribution of metabolites during processing, we compared the results obtained by conventional aldehyde fixation with those obtained by cryofixation and cryosubstitution with and without cryoembedding. Bromine appeared to be concentrated in two sponge structures, viz. fibres and spherulous cells, when cryofixed material was examined. However, X-ray microanalysis failed to demonstrate the presence of bromine in spherulous cells in chemically fixed samples, showing the need for cryotechniques to avoid the loss of compounds. Cryofixation plus cryosubstitution methods performed best regarding structural preservation and the immobilization of metabolites. The presence of bromine in the spherulous cells suggests that this cell type is the producer of the secondary metabolites, as described for other sponge species. Nevertheless, the presence of bromine in sponge fibres indicates that they can accumulate metabolic substances, although we have been unable to assess whether the chemicals are in their original form or in a modified state within the fibres. A. aerophoba has both bacterial and cyanobacterial symbionts in its mesohyl; the absence of brominated compounds in them contrasts with previous findings in other sponges with prokaryote symbionts.

Animals↗
PubMedDate not supplied

Antibiotic and cytotoxic activity of brominated compounds from the marine sponge Verongia aerophoba.

Analysis of the marine sponge Verongia aerophoba from the Canary Islands afforded eight brominated secondary metabolites including the small molecular weight compounds aeroplysinin-1 (5) and the dienone (7) which were previously shown to arise by enzymatically catalyzed degradation of aerophobin-2 (4) and isofistularin-3 (1) following breakdown of the cellular compartmentation of the sponge. All compounds were identified from their NMR and mass spectra. Aeroplysinin-1 as well as dienone which arise from isofistularin-3 or aerophobin-2 by biotransformation within the sponge showed a significantly higher antibiotic as well as cytotoxic activity than their biogenetic precursors. Antibiotic activity was studied with respect to several gram-positive and gram-negative bacteria including B. subtilis, S. aureus and E. coli. The MICs (MBCs) of aeroplysinin-1 (5) and the dienone (7) varied between 12.5-25 (50-100) micrograms/ml respectively. Cytotoxicity was tested in vitro towards HeLa cells, a human cervix uteri tumour cell line. Aeroplysinin-1 (5) and the dienone (7) displayed pronounced cytotoxic activity with IC50s of 3.0 and 3.2 microM respectively. A five-fold increase in cytotoxicity was observed after O-acetylation of the dienone (7). The IC50 of the dienone O-acetate (0.6 microM) was comparable to that of the clinically used anticancer drug cisplatin (0.7 microM).

Animals↗
PubMed1976

Antibacterial activity of marine violet-pigmented Alteromonas with special reference to the production of brominated compounds.

The synthesis of several types of antibiotics was investigated in four strains of violet-pigmented bacteria belonging to the species Alteromonas luteo-violaceus. Two of the strains simultaneously produce an antibiotic polyanionic polysaccharide, weakly bound to the cells and diffusing throughout the medium, and two intracellular brominated bactericidal substances. The third strain only synthesizes the polyanionic antibiotic. The fourth one is totally inactive. The macromolecular antibiotic, probably responsible for the autointoxication of the bacteria in their cultures, acts at the respiratory level; it induces an increase of oxygen uptake and the production of peroxides by test bacteria. Thus, its activity is inhibited by catalase and peroxidase.

Anti-Bacterial Agents↗
PubMed1984

Anticholinesterase action of a bromine compound isolated from human cerebrospinal fluid.

L-1- Methylheptyl -gamma- bromoacetoacetate was found to be a competitive inhibitor of the acetylcholinesterases (electric eel, Ki = 17.2 microM; rat brain, Ki = 32.6 microM) and of butyrylcholinesterase (horse serum, Ki = 1.2 microM). The L-isomer was a more effective inhibitor than the D-isomer. The bromine atom at the gamma-position of the acidic moiety, the specific length of the carbon chain constituting the secondary alcohol moiety, and the presence of the ketone radical at the acidic moiety of the ester were necessary for the anticholinesterase action. 1- Methylheptyl -gamma- bromoacetoacetate formed a complex with acetylcholinesterase or butyrylcholinesterase without hydrolysis of its own molecule.

Acetoacetates↗
PubMed1988

Chemical pneumonitis due to exposure to bromine compounds.

A 60-year-old laboratory technician developed pulmonary infiltrates consistent with chemical pneumonitis following accidental exposure to a mixture of hydrogen bromide and phosphorus tribromide. A protracted clinical course ensued consistent with bronchiolitis obliterans. These problems may have been avoided if the potential for subsequent damage had been realized at the time of the initial exposure. Health personnel must be aware of the potentially delayed effects of accidental exposures to respiratory irritants.

Bromine↗
PubMed1987

Responses of marine unicellular algae to brominated organic compounds in six growth media.

Marine unicellular algae, Skeletonema costatum, Thalassiosira pseudonana, and Chlorella sp. were exposed to the industrial brominated compounds tetrabromobisphenol A, decabromobiphenyloxide (DBBO), hexabromocyclododecane (HBCD), pentabromomethylbenzene (PBMB), pentabromoethylbenzene (PBEB), and the herbicide bromoxynil (BROM), in six algal growth media. High concentrations of DBBO (1 mg liter-1), PBMB (1 mg liter-1), and PBEB (0.5 mg liter-1) reduced growth by less than 50%. EC50s of the other compounds varied with growth medium, with high EC50/low EC50 ratios between 1.3 and 9.9. Lowest EC50s, 9.3 to 12.0 micrograms liter-1, were obtained with S. costatum and HBCD. It is concluded that responses to toxicants in different media are the results of interactions among algae, growth medium, toxicant, and solvent carrier.

Eukaryota↗
PubMed1999

Novel brominated lipidic compounds from lichens of central Asia.

The composition of novel brominated aliphatic compounds from lichens collected during summer from stones around the lake Issyk-Kul (Central Asia) is described. The compounds, predominantly fatty acid derivatives with unique groups (bromine, cyclopropane, oxirane) and conjugated double and triple bonds, were identified by means of 1H and 13C-NMR, MS, IR and UV spectra.

Bromine↗
PubMed2003

Nonselective bromination-selective debromination strategy: selective bromination of unsymmetrical ketones on singly activated carbon against doubly activated carbon.

[reaction: see text] We have found a new synthetic method for the preparation of the alpha-bromoketones that are brominated in the less activated terminal position of unsymmetrical ketones. Brominations in short reaction times (kinetically controlled) provided internally brominated compounds as a major product. However, brominations in longer reaction times (thermodynamically controlled) gave more of the terminally brominated compound through the reversible reaction by Br(2) and produced hydrogen bromide. Several brominated compounds at the terminal position were successfully prepared through the new synthetic route.

Journal Article↗