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2-Bromophenol
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Claudiu T. Supuran – One of the best experts on this subject based on the ideXlab platform.
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synthesis and carbonic anhydrase isoenzymes i ii ix and xii inhibitory effects of dimethoxybromophenol derivatives incorporating cyclopropane moieties
Journal of Medicinal Chemistry, 2015Co-Authors: Murat Boztas, Meryem Topal, Abdullah Menzek, Muhammet Tanc, Yasin Cetinkaya, Ilhami Gulcin, Ertan şahin, Claudiu T. SupuranAbstract:Cyclopropylcarboxylic acids and esters and cyclopropylmethanols incorporating bromophenol moieties were investigated as inhibitors of the carbonic anhydrase enzyme (CA; EC 4.2.1.1). The cis- and trans-esters 5 and 6 were obtained from the reaction of 4-allyl-1,2-dimethoxybenzene (4) with ethyl diazoacetate, which after bromination with Br2 gave two isomeric monobromides (11 and 15), four isomeric dibromides (12, 13, 16, and 17), and two isomeric tribromides (14 and 18). The carboxylic acids 7, 8, and 19–26 were thereafter obtained by hydrolysis of the synthesized esters. All these bromophenol derivatives were tested against human (h) CA isoenzymes I and II (cytosolic, ubiquitous isoforms) and hCA IX and XII (transmembrane, tumor-associated enzymes). All tested bromophenols exhibited excellent inhibitory effects, in the low nanomolar range, with Ki values in the range of 0.54–59 nM against hCA I and in the range of 0.97–12.14 nM against hCA II, whereas they were low micromolar inhibitors against hCA IX and…
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Synthesis and Carbonic Anhydrase Isoenzymes I, II,
IX, and XII Inhibitory Effects of Dimethoxybromophenol Derivatives
Incorporating Cyclopropane Moieties, 2015Co-Authors: Murat Boztaş, Yasin Çetinkaya, Meryem Topal, İlhami Gülçin, Abdullah Menzek, Ertan Şahin, Muhammet Tanc, Claudiu T. SupuranAbstract:Cyclopropylcarboxylic
acids and esters and cyclopropylmethanols
incorporating bromophenol moieties were investigated as inhibitors
of the carbonic anhydrase enzyme (CA; EC 4.2.1.1). The cis- and trans-esters 5 and 6 were obtained from the reaction of 4-allyl-1,2-dimethoxybenzene
(4) with ethyl diazoacetate, which after bromination
with Br2 gave two isomeric monobromides (11 and 15), four isomeric dibromides (12, 13, 16, and 17), and two isomeric
tribromides (14 and 18). The carboxylic
acids 7, 8, and 19–26 were thereafter obtained by hydrolysis of the synthesized
esters. All these bromophenol derivatives were tested against human
(h) CA isoenzymes I and II (cytosolic, ubiquitous isoforms) and hCA
IX and XII (transmembrane, tumor-associated enzymes). All tested bromophenols
exhibited excellent inhibitory effects, in the low nanomolar range,
with Ki values in the range of 0.54–59
nM against hCA I and in the range of 0.97–12.14 nM against
hCA II, whereas they were low micromolar inhibitors against hCA IX
and XII. The best hCA I inhibition was observed in new bromophenol
derivative 20 (Ki = 0.54
nM). On the other hand, new bromophenol derivative 12 showed a powerful inhibition effect against hCA II (Ki = 0.97 nM)
Bingui Wang – One of the best experts on this subject based on the ideXlab platform.
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new nitrogen containing bromophenols from the marine red alga rhodomela confervoides and their radical scavenging activity
Food Chemistry, 2012Co-Authors: James B Gloer, Bingui WangAbstract:In addition to nine known bromophenol derivatives, five new nitrogen-containing bromophenols were isolated from an ethyl acetate extract of the marine red alga Rhodomela confervoides. By using spectro-scopic methods, the structures of the new compounds were identified as 3-(2,3-dibromo-4,5-dihydroxybenzyl)pyrrolidine-2,5-dione (1), methyl 4-(2,3-dibromo-4,5-dihydroxybenzylamino)-4-oxobutanoate (2), 4-(2,3-dibromo-4,5-dihydroxybenzylamino)-4-oxobutanoic acid (3), 3-bromo-5-hydroxy-4-methoxybenzamide (4), and 2-(3-bromo-5-hydroxy-4-methoxyphenyl)acetamide (5). All of these bromophenols showed potent scavenging activity against DPPH (1,1-diphenyl-2-picrylhydrazyl) radicals, with IC50 values ranging from 5.22 to 23.60 mu M. These compounds also displayed moderate activity against ABTS (2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonate) radicals, with Trolox Equivalent Antioxidant Capacity values (TEAC) ranging from 2.11 to 3.58 mM. The results obtained in this study demonstrate that the bromophenols obtained from R. confervoides may have potential application in food and/or pharmaceutical fields as natural antioxidants. (C) 2012 Elsevier Ltd. All rights reserved.
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natural bromophenols from the marine red alga polysiphonia urceolata rhodomelaceae structural elucidation and dpph radical scavenging activity
Bioorganic & Medicinal Chemistry, 2007Co-Authors: Bingui WangAbstract:Three new natural occurring bromophenols, 3-(3-bromo-4,5-dihydroxyphenyl)-2-(3,5-dibromo-4-hydroxyphenyl)propionic acid (1), (E)-4-(3-bromo-4,5-dihydroxyphenyl)-but-3-en-2-one (2), and (3,5-dibromo-4-hydroxyphenyl) acetic acid butyl ester (3), together with one known bromophenol, 1,2-bis(3-bromo-4,5-dihydroxyphenyl)ethane (4), were isolated and identified from the marine red alga Polysiphonia urceolata. The structures of these compounds were elucidated by extensive analysis of ID and 2D NMR and IR spectra and MS data. Each of the isolated compounds was evaluated for scavenging alpha,alpha-diphenyl-beta-picrylhydrazyl (DPPH) radical activity and all of them exhibited significant activity with IC50 values ranging from 9.67 to 21.90 mu M, compared to the positive control, a well-known antioxidant butylated hydroxytoluene (BHT), with IC50 83.84 mu M. (C) 2007 Elsevier Ltd. All rights reserved.
Barry Dellinger – One of the best experts on this subject based on the ideXlab platform.
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Formation of bromochlorodibenzo-p-dioxins and dibenzofurans from the high-temperature oxidation of a mixture of 2-chlorophenol and 2-Bromophenol.
Environmental science & technology, 2006Co-Authors: Catherine S. Evans, Barry DellingerAbstract:The homogeneous, gas-phase oxidative thermal degradation of a 50:50 mixture of 2-Bromophenol and 2-chlorophenol was studied in a 1 cm i.d., fused silica flow reactor at a concentration of 88 ppm, with a reaction time of 2.0 s, over a temperature range of 300 to 1000 °C. Observed products in order of decreasing yield included the following: dibenzo-p-dioxin (DD), 4-bromo-6-chlorodibenzofuran (4-B,6-CDF), phenol, 4,6-dibromodibenzofuran (4,6-DBDF), 2,6-dibromophenol, 4,6-dichlorodibenzofuran (4,6-DCDF), 2-bromo-4-chlorophenol, 2,4-dibromophenol, 2-chloro-4-bromophenol, 4-monobromodibenzofuran (4-MBDF), 4-monochlorodibenzofuran (4-MCDF), dibenzofuran (DF), 1-monobromodibenzo-p-dioxin (1-MBDD), 1-monochlorodibenzo-p-dioxin (1-MCDD), 2,4,6-tribromophenol, naphthalene, chloronaphthalene, bromonaphthalene, chlorobenzene, bromobenzene, and benzene. The results are compared and contrasted with previous results reported for the oxidations of pure 2-chlorophenol and 2-Bromophenol as well as results for the pyrolysi…
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Surface-mediated formation of PBDD/Fs from the high-temperature oxidation of 2-Bromophenol on a CuO/silica surface.
Chemosphere, 2005Co-Authors: Catherine S. Evans, Barry DellingerAbstract:Abstract As a model brominated hydrocarbon that may form brominated dioxins, we studied the surface-mediated, oxidative thermal degradation of 2-Bromophenol on a supported copper oxide catalyst in a 1 mm i.d., fused silica flow reactor at a constant concentration of 90 ppm over a temperature range from 250 to 550 °C. Observed products included: dibenzo- p -dioxin (DD), 1-monobromodibenzo- p -dioxin (1-MBDD), dibromodibenzo- p -dioxin (DBDD), tribromodibenzo- p -dioxin (TrBDD), 4-monobromodibenzofuran (4-MBDF), 2,4,6-tribromophenol, 2,4- and 2,6-dibromophenol, and polybrominated benzenes. The results are compared and contrasted with previous work on surface catalyzed oxidative thermal degradation of 2-chlorophenol as well as our own work with the surface-catalyzed pyrolytic thermal degradation of 2-Bromophenol. Typically 20 to 200× higher yields of PBDDs are observed for 2-Bromophenol than for the analogous PCDDs for 2-chlorophenol. However the anticipated PBDF, 4,6-DBDF, was not observed and 4-MBDF was observed at very low yields. Surprisingly, the maximum yields of PBDDs were observed at higher temperatures than under pyrolytic conditions. This is attributed to regeneration of the catalytic surface due to the presence of oxygen. Higher yields of polybrominated phenols and polybrominated benzenes were also observed than for the analogous chlorinated phenols and benzenes from the oxidation of 2-chlorophenol. This can be attributed to the ease of bromination over chlorination based on the higher abundance of bromine atoms present for 2-Bromophenol than chlorine atoms present for 2-chlorophenol.
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Formation of bromochlorodibenzo-p-dioxins and furans from the high-temperature pyrolysis of a 2-chlorophenol/2-Bromophenol mixture.
Environmental science & technology, 2005Co-Authors: Catherine S. Evans, Barry DellingerAbstract:The homogeneous, gas-phase pyrolytic thermal degradation of a 50:50 mixture of 2-Bromophenol and 2-chlorophenol was studied in a 1 cm i.d., fused silica flow reactor at a total concentration of 88 ppm, reaction time of 2.0 s, and temperatures from 300 to 1000 °C. Observed products included (in decreasing yield) naphthalene, dibenzo-p-dioxin (DD), phenol, dibenzofuran (DF), bromobenzene, chloronaphthalene, 4-bromo-6-chlorodibenzofuran (4-B,6-CDF), bromonaphthalene, benzene, 4,6-dichlorodibenzofuran (4,6-DCDF), chlorobenzene, 4-monobromodibenzofuran (4-MBDF), 4-monochlorodibenzofuran (4-MCDF), 1-monobromodibenzo-p-dioxin (1-MBDD), 2-chloro,4-bromophenol, 2,4-dibromophenol, and 2-bromo-4-chlorophenol. Unlike the case for the pyrolysis of pure 2-chlorophenol, 4,6-DCDF was observed, but the analogous 4,6-DBDF remained undetected similar to the individual results with 2-MBP. This indicates that the presence of bromine increases the concentration of chlorine atoms available for the formation of 4,6-DCDF. Due to …