• Journal of the Korean Magnetic Resonance Society
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• v.11 no.1
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• pp.56-63
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• 2007

A series of bromophenols and corresponding debrominated phenolic compounds was prepared by isolation from red alga Tichocarpus crinitus and by structural modification of natural bromophenols. Their structures were determined by extensive NMR analysis and the antioxidant activities were established through the determination of their abilities to inhibit free radicals using DPPH as the stable radical. The most active free radical scavengers were the debrominated phenolic derivatives 3,4-dihydroxybenzyl alcohol and 3,3',4,4'-tetrahydroxydiphenylmethane.

• Food Science and Biotechnology
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• v.17 no.5
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• pp.1110-1114
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• 2008

$\beta$-Glucuronidases of intestinal bacteria are capable of retoxifying compounds that have been detoxified by liver glucuronidation, which is one of the most important detoxication processes in the liver. Therefore, this enzyme is known to accelerate colon cancer invasion and metastasis. Two bromophenols, 2,4,6-tribromophenol (I) and 2,4-dibromophenol (II), were purified from the red alga Grateloupia elliptica. $IC_{50}$ values of bromophenol I and II against Escherichia coli $\beta$-glucuronidase were 5.4 and 8.5 mg/mL, respectively. Hence, bromophenols of G. elliptica, a potent $\beta$-glucuronidase inhibitor, can be used as a novel pharmaceutical agent for the prevention and treatment of colon cancer.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.47 no.1
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• pp.45-51
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• 2014

Scuticociliates are regarded as serious pathogens in marine aquaculture worldwide. In Korea, they cause mass-mortalities in fish such as the commercially important olive flounder Paralichthys olivaceus. In particular, mixed infections of scuticociliates with pathogenic bacteria have been commonly reported. During efforts to identify natural marine-algae derived products that possess anti-bacterial and anti-scuticociliate properties, we found that an 80% methanolic extract of the red alga Polysiphonia morrowii Harvey exhibits both anti-scuticociliate activity against Miamiensis avidus, which is a major causative agent of scuticociliatosis, and anti-bacterial activities against fish pathogenic bacteria. Activity-guided fractionation and isolation of the 80% methanolic extract of P. morrowii yielded three bromophenols, which were identified as 3-bromo-4,5-dihydroxybenzyl methyl ether (1), 3-bromo-4,5-dihydroxybenzaldehyde (2) and urceolatol (3) based on spectroscopic analyses. 3-bromo-4,5-dihydroxybenzyl methyl ether (1) showed the highest anti-bacterial and anti-scuticociliate activities, with a minimal inhibitory concentration (MIC) of $62.5{\mu}g/mL$ (against Vibrio anguillarum) and minimal lethal concentration (MLC) of 62.5 ppm (in seawater). Investigations of the anti-bacterial and anti-scuticociliate activities of seventeen bromophenol derivatives, including the three isolated natural bromophenols, showed that the existence of an electron donating group or atom with a non-covalent electron pair at $C_4$ of the 2-bromophenol structure may be important in anti-scuticociliate activity. These findings suggest that the extract and bromophenol derivatives of P. morrowii may provide useful alternatives in aquaculture anti-scuticociliate therapies.

• Fisheries and Aquatic Sciences
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• v.10 no.3
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• pp.113-118
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• 2007

Bromophenols are a group of compounds found only in marine organisms. They accumulate and give a sea-like aroma to marine animals. Cultivated fishes generally contain low concentrations of bromophenols compared to wild fishes. Feeding cultivated fishes with bromophenol-containing seaweed could increase their bromophenol content and thus improve their flavor quality. We evaluated the effect of an experimental feed on the bromophenol content of green grouper, Epinephelus coioides, during an 8-week feeding period. Green grouper individuals were divided into two groups and fed with conventional feed or experimental feed containing dried seaweed. Fish were collected biweekly for 8 weeks for proximate analyses and bromophenol content evaluations. Bromophenols were extracted, identified, and quantified by gas chromatography-mass spectrometry. Both moisture and lipid contents were generally higher in the controls; however, total weight and protein content were higher in the experimental group. Only 2,4-dibromophenol and 2,4,6-tribromophenol were detected in the samples. Throughout the 8 weeks, 2,4,6-tribromophenol concentrations were higher in the experimental group (9.20-32.3 ng/g dry wt) than in the control group (7.33-18.79 ng/g dry wt), but no significant difference in 2,4-dibromophenol concentration was detected between the two groups. The total bromophenol content reached a maximum at week 4 for the experimental feed and week 6 for the control. In short, experimental feed that incorporated bromophenol-containing seaweed increased the total bromophenol content in the green grouper.

• Bulletin of the Korean Chemical Society
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• v.24 no.9
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• pp.1276-1280
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• 2003

Thermal behavior of bromphenols was investigated by direct pyrolysis at high temperature. The thermal degradation products formed by the pyrolysis of mono-bromophenols (o-, m-, and p-) were identified by gas chromatography-mass spectrometry. During the pyrolysis reactions, several kinds of dioxins and furans were produced, and the relative ratio of pyro-products was dependent on the substituted position of bromine in phenolic structure due to the effect of symmetry and steric hindrance. The formation of dioxins can be explained by the phenoxy radical addition and Br atom elimination at an ortho-carbon site on phenolic structure. On the other hand, the formation of furans can be explained by the ortho-ortho carbon coupling of phenoxy radicals at unsubstituted sites to form o, o'-dihydroxydiphenyl intermediate via its keto-tautomer, followed by $H_2O$ elimination. The pyrolysis temperature has also a substantial effect on the dimerized products quantities but little effect on the type of pyro-products. Moreover, the formation mechanism of pyro-products was suggested on the basis of products identified.