Free Radical Reductive Degradation of vic-Dibromoalkanes and Reaction of Bromine Atoms with Polyunsaturated Fatty Acids: Possible Involvement of Br. in the 1,2-Dibromoethane-Induced Lipid-Peroxidation

Guha, S. N.; Schöneich, Christian; Asmus, K.‐D.

doi:10.1006/abbi.1993.1402

Cited by 16 publications

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“…In the proposed mechanism (Scheme ), persulfate generates sulfate radical primarily through thermal activation (step 1). − Next, in the presence of halides, sulfate radicals are scavenged by halides to produce halogen radicals (step 2). , Halogen radicals then react with chemical additives (e.g., cinnamaldehyde) to form halogenated products (step 3). However, a key question in our mechanism remains regarding whether halogen radicals directly add to chemical additives (step 3a) , or form nonradical halogen oxidants (i.e., hypohalous acid, step 3b) via recombination reactions − ,, to react with chemical additives (e.g., cinnamaldehyde) for halogenation. − Hypohalous acids (in particular, HOBr) added at concentrations produced from radical recombination (Figure S5) do react with cinnamaldehyde to produce halogenated products (Text S1.9, Figure S8), suggesting that the second pathway may be feasible.…”

Section: Resultsmentioning

confidence: 99%

“…In sunlit seawater, the presence of halogen radicals accelerates the transformations of certain pollutants and biogeochemically relevant compounds. − In addition to altering reaction rates, halogen radicals also alter reaction mechanisms by enabling halogenation both directly and indirectly. Directly, halogen radicals add to the structure of certain aromatic and olefinic molecules. , Indirectly, halogen radicals react via termination reactions to generate other halogenating agents (i.e., hypohalous acid), − which react with organics through substitution − or addition …”

Section: Introductionmentioning

confidence: 99%

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Halogen Radicals Contribute to the Halogenation and Degradation of Chemical Additives Used in Hydraulic Fracturing

Chen

Rholl

et al. 2021

Environ. Sci. Technol.

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In hydraulic fracturing fluids, the oxidant persulfate is used to generate sulfate radical to break down polymer-based gels. However, sulfate radical may be scavenged by high concentrations of halides in hydraulic fracturing fluids, producing halogen radicals (e.g., Cl•, Cl2 •–, Br•, Br2 •–, and BrCl•–). In this study, we investigated how halogen radicals alter the mechanisms and kinetics of the degradation of organic chemicals in hydraulic fracturing fluids. Using a radical scavenger (i.e., isopropanol), we determined that halogenated products of additives such as cinnamaldehyde (i.e., α-chlorocinnamaldehyde and α-bromocinnamaldehyde) and citrate (i.e., trihalomethanes) were generated via a pathway involving halogen radicals. We next investigated the impact of halogen radicals on cinnamaldehyde degradation rates. The conversion of sulfate radicals to halogen radicals may result in selective degradation of organic compounds. Surprisingly, we found that the addition of halides to convert sulfate radicals to halogen radicals did not result in selective degradation of cinnamaldehyde over other compounds (i.e., benzoate and guar), which may challenge the application of radical selectivity experiments to more complex molecules. Overall, we find that halogen radicals, known to react in advanced oxidative treatment and sunlight photochemistry, also contribute to the unintended degradation and halogenation of additives in hydraulic fracturing fluids.

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Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Halogen Radicals Contribute to the Halogenation and Degradation of Chemical Additives Used in Hydraulic Fracturing

Chen

Rholl

et al. 2021

Environ. Sci. Technol.

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“…The reactions of Brи with phenoxide ion forms were also very high and almost diffusion controlled, giving rise to corresponding phenoxyl radicals. It should be noted that metabolic activation of DBE, which has been used as a lead scavenger in gasoline, may lead to formation of highly oxidizing Brи radicals, which may account for the observation that in vivo metabolism of DBE could enhance lipid peroxidation [15]. From the results of the preceding Brи reaction it is seen that both eugenol and isoeugenol are capable of scavenging this highly damaging free radical, which causes lipid peroxidation.…”

Section: Reaction Of Brи With Egohmentioning

confidence: 96%

Kinetic and redox characteristics of phenoxyl radicals of eugenol and isoeugenol: A pulse radiolysis study

Guha

Priyadarsini

2000

Int J Chem Kinet

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The phenoxyl radicals of eugenol (EgOH) and isoeugenol (iEgOH) were generated by the specific one-electron oxidant N 3 и using pulse radiolysis technique, and were characterized by their absorption spectra, decay and formation kinetics, and one-electron reduction potential (E 7 1 ) values. Reactivities of eugenol phenoxyl radical with the biologically important molecule, trolox C (analogue of vitamin E, ␣-tocopheral), were determined. Reactions of OH with these phenols were studied at different pHs and suitable mechanisms for these reactions were suggested. Scavenging abilities of the phenols toward highly damaging Brи, NO 2 и, and CCl 3 O 2 и radicals were evaluated.

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“…This is in agreement with several papers which demonstrated that reactive oxygen species increase as well as redox status alteration are common features in cancer cells (Harris et al, 2015; Su et al, 2019; Zhong et al, 2017). In this scenario, bromine atoms could have a pivotal role as initiator for lipid peroxidation since they can react with polyunsaturated fatty acids, the lipid membrane components which represent also the substrate for radical species interaction (Guha et al, 1993).…”

Section: Discussionmentioning

confidence: 99%

Morpho‐functional analyses reveal that changes in the chemical structure of a marine bisindole alkaloid alter the cytotoxic effect of its derivatives

Burattini

Battistelli

Verboni

et al. 2022

Microscopy Res & Technique

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2,2-bis(6-bromo-1H-indol-3-yl) ethanamine, a marine bisindole alkaloid, showed anticancer property in several tumor cell lines thanks to the presence of a 3,3 0diindolylmethane scaffold. Here, the modifications in its chemical structure into alkaloid-like derivatives, have been evaluated, to investigate changes in its biological activities. Three derivatives have been considered and their potential apoptotic action has been evaluated through morpho-functional analyses in a human cancer cell line. Apoptosis appears strongly decreased in the derivatives without the bromine atoms (1) and in those where the bromine atoms have been substituted with fluorine atoms (2). On the contrary, the methylation of indole NH (3) does not alter the alkaloid apoptotic activity that occurs through mitochondria involvement supported by cardiolipin peroxidation and dysfunctional mitochondria presence. This manuscript highlights the alkaloid derivative cytotoxic effect, which is strictly correlated to the presence of N-methylated bisindole alkaloid and bromine atoms, conditions which assure to maintain the pro-apoptotic activity. Since molecular therapies, by targeting mitochondria pathways, have shown positive outcomes against several cancer cells, the alkaloid with bisindole methylated scaffold and the two bromine atoms can be considered a promising candidate to develop new derivatives with strong anticancer property.anticancer activity, apoptotic cell death, marine alkaloids, mitochondria damage, U937 cell line Research Highlights• 2,2-bis(6-bromo-1H-indol-3-yl) ethanamine is an alkaloid known for its anticancer properties.• Morpho-functional analyses evaluated cytotoxicity of its synthetic derivatives in tumor cells.• Anticancer properties depend on the presence of bisindole scaffold and the two bromine units.Marine bisindole alkaloids showed significant cytotoxicity, antineoplastic and antimicrobial properties (Kamel et al., 2020; Veale & Davies-Coleman, 2014). In particular, 2,2-bis(6-bromo-3-indolyl) ethanamine (BrDIMEA), extracted from the Californian tunicate Didemnum candidum and the New Caledonian sponge Orina (Salucci et al., 2018), is a strong cytotoxic agent and its anticancer

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Free Radical Reductive Degradation of vic-Dibromoalkanes and Reaction of Bromine Atoms with Polyunsaturated Fatty Acids: Possible Involvement of Br. in the 1,2-Dibromoethane-Induced Lipid-Peroxidation

Cited by 16 publications

References 0 publications

Halogen Radicals Contribute to the Halogenation and Degradation of Chemical Additives Used in Hydraulic Fracturing

Halogen Radicals Contribute to the Halogenation and Degradation of Chemical Additives Used in Hydraulic Fracturing

Kinetic and redox characteristics of phenoxyl radicals of eugenol and isoeugenol: A pulse radiolysis study

Morpho‐functional analyses reveal that changes in the chemical structure of a marine bisindole alkaloid alter the cytotoxic effect of its derivatives

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