• Korean Journal of Fisheries and Aquatic Sciences
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• v.31 no.1
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• pp.1-7
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• 1998

Uronate compositions and molecular weights of alginates from the four kinds of brown algae, sea mustard (Undaria pinnatifida), sea tangle (Laminaria japonica), gulf weed (Sargassum fulvellum), and seaweed fusiforme (Hizikia fusiforme), in regard with the harvesting season were investigated. Sea mustard contained the highest amount of alginates in the four kinds of brown algae. D-Mannuronic acid to L-guluronic acid (M/C) ratio of the alginates was high in order of seaweed fusiforme, gulf weed, sea mustard, and sea tangle, and especially in water-soluble alginate. Molecular weights of the alginates were greater with the growing period ranging in $4,500\~4,800\;kDa$ for sea tangle, $4,000\~4,200\;kDa$ for sea mustard, $3,300\~3,400\;kDa$ for seaweed fusiforme, and $3,000\~3,200\;kDa$ for gulfweed. In water-soluble alginate of sea mustard, M/G ratio was much higher in sporophyll than in midrib and blade.

• Korean Journal of Food Science and Technology
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• v.23 no.3
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• pp.256-261
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• 1991

To isolate new antioxidants from twelve edible seaweeds, mixed methanol and chloroform extract of marine algae was fractionated into several subfractions and their antioxidant activities were measured by using AOM and 1, 1-diphenyl-2-picrylhydrazyl (DPPH). Especially the aqueous-methanol soluble fractions of brown and red algae showed a considerable antioxidant effect. Their antioxidant activities were stronger than synthetic antioxidants such as BHA, BHT, under the same concentration. Further fractionation of the aqueous-methanol soluble fractions using silica gel column chromatography yielded five subfractions. Among them methanol fraction exhibited high DPPH quenching activities. Also, it was confirmed to be benzene-derivative substances of two compounds by UV, HPLC, GC/MS analysis. Its each molecular weight was about 181, 238. These results suggested the existence of two effective natural antioxidant compounds in three edible marine algae.

• Archives of Pharmacal Research
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• v.27 no.12
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• pp.1226-1232
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• 2004

Extracts from seventeen seaweeds were determined for tyrosinase inhibitory activity using mushroom tyrosinase with L-tyrosine as a substrate. Only one of them, Ecklonia stolonifera OKAMURA (Laminariaceae) belonging to brown algae, showed high tyrosinase inhibitory activity. Bioassay-guided fractionation of the active ethyl acetate (EtOAc) soluble fraction from the methanolic extract of E. stolonifera, led us to the isolation of phloroglucinol derivatives [phloroglucinol (1), eckstolonol (2), eckol (3), phlorofucofuroeckol A (4), and dieckol (5)]. Compounds 1~5 were found to inhibit the oxidation of L-tyrosine catalyzed by mushroom tyrosinase with $IC_{50}$ values of 92.8, 126, 33.2, 177, and 2.16 ${\mu}g$ /mL, respectively. It was compared with those of kojic acid and arbutin, well-known tyrosinase inhibitors, with $IC_{50}$ values of 6.32 and 112 ${\mu}g$ / mL, respectively. The inhibitory kinetics analyzed from Lineweaver-Burk plots, showed compounds 1 and 2 to be competitive inhibitors with $K_i$ of $2.3{\times}10^{-4}\;and\;3.1{times}10^{-4}$ M, and compounds 3~5 to be noncompetitive inhibitors with $K_i$ of $1.9{\times}10^{-5},\;1.4{\times}10^{-3}\;and\;1.5{\times}10^{-5}$ M, respectively. This work showed that phloroglucinol derivatives, natural compounds found in brown algae, could be involved in the control of pigmentation in plants and other organisms through inhibition of tyrosinase activity using L-tyrosine as a substrate.

• Archives of Pharmacal Research
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• v.27 no.2
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• pp.194-198
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• 2004

Reactive oxygen species (ROS) play an important role in the pathogenesis of many human degenerative diseases such as cancer, aging, arteriosclerosis, and rheumatism. Much attention has been focused on the development of safe and effective antioxidants. To discover sources of antioxidative activity in marine algae, extracts from 17 kinds of seaweed were screened for their inhibitory effect on total ROS generation in kidney homogenate using 2',7'-dichlorofluorescein diacetate (DCFH-DA). ROS inhibition was seen in three species: UIva pertusa, Symphyocladia latiuscula, and Ecklonia stolonifera. At a final concentration of 25 $\mu\textrm{g}$/mL, U. pertusa inhibited 85.65$\pm$20.28％ of total ROS generation, S. latiscula caused 50.63$\pm$0.09％ inhibitory, and the Ecklonia species was 44.30$\pm$7.33％ inhibition. E. stolonifera OKAMURA (Lam-inariaceae), which belongs to the brown algae, has been further investigated because it is commonly used as a foodstuff in Korea. Five compounds, phloroglucinol (1), eckstolonol (2), eckol (3), phlorofucofuroeckol A (4), and dieckol (5), isolated from the ethyl acetate soluble fraction of the methanolic extrclct of E. stolonifera inhibited total ROS generation.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1998.11a
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• pp.162-162
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• 1998

Various natural compounds act as antioxidants in protection against lipid peroxidation. Lipid peroxidation yields a variety of decomposition products which have been implicated in not only decreasing the nutritional value of food, but also in developing an off-flavor and toxic substances. As a source of safer and more effective natural antioxidants of natural origin have been widely investigated. Some Indonesian plants have evaluated for their antioxidative activity, and suggested the possible existence of various antioxygenic compounds in them. We attempted to study such antioxygenic compounds with simple method evaluation. As we are interested in the natural product compounds, we examined of several sample such as edible sea-weeds, and some edible fruits. Sea-weed, Eisenia bicyclis, one of the edible brown algae, exhibited the activity. As a traditional food additive consumed by Indonesian, Garcinia parvifolia is used as taste supplement in region West Sumatra, have been studied. Our current studies on the semi-polar fractions shows the activity by the thiocyanate method test. Another sample, Garcinia mangostana, a famous fruit with sweet taste, the part kernel have also evaluated. The acidic fraction of the extract showed antioxidative activity. Some other active components were found in the neutral and BuOH fractions.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.30 no.6
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• pp.909-915
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• 1997

The nitrite scavenging effect of methanol extracts of marine algae were evaluated to discover new natural nitrite scavengers. Among the tested seaweeds, Ecklonia stolonifera, an edible brown algae, showed the strongest scavenging effect. The MeOH extract was then sequentially partitioned into $CH_2Cl_2,\;CH_2Cl_2$ insoluble interface, EtOAc, n-BuOH, and $H_2O$ layers. The EtOAc and n-BuOH fraction demonstrated high levels of nitrite-scavenging activity while the $CH_2Cl_2,\;CH_2Cl_2$ insoluble interface, and $H_2O$ fractions were inactive. A column chromatography of the EtOAc fraction through silica gel and Sephadex LH-20 yielded phloroglucinol and a new compound tentatively named phlorotannin A. The nitrite scavenging activity of phloroglucinol $(IC_{50}=3.9{\mu}g/ml)$ was more potent than that of L-ascorbic acid $(IC_{50}=65.0{\mu}g/ml)$. However, phlorotannin A $(IC_{50}=193.2{\mu}g/ml)$ showed only low levels of activity. From the above results, it is possible to suggest that both the MeOH extract and their fractions and isolated phloroglucinol and phlorotannin A obtained from E. stolonifera may be applicable as scavengers of nitrite, which is a precursor for the formation of carcinogenic N-nitroso compounds.

• Journal of Marine Bioscience and Biotechnology
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• v.5 no.4
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• pp.8-14
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• 2011

Although marine living organism contains a numerious number of compounds, it is difficult to collect these compounds in a large scale for medicinal application. However, in recent years, several bioactive compounds isolated from marine macroalgae have been proved to be able to provide potential sources for development of medicinal products because they can be obtained in large amount from marine. A number of studies have reported a variety of effects of marine macroalgae but a few anti-inflammatory activity of marine macroalgae have recently been published. Herein, we reviewed novel anti-inflammatory compounds recently isolated from marine brown algae, green algae and red algae. From this survey, in particular, some compounds contained in edible macroalgae exert anti-inflammatory effects with inhibition on cyclooxygenase-2 (COX-2), inducible nitric oxide synthase(iNOS) and matrix metalloproteinases (MMPs) activity regulated by nuclear factor-kappa B transcription factor that play a key role in cancer as well as inflammation, demonstrating to be able to potentially apply to development of anti-inflammatory agent for chemoprevention of cancer. Furthermore, some macroalgae and their compounds with both excellent anti-inflammatory activity and very low toxicity can select a potential candidates capable of preventing or treating several chronic inflammation such as colitis, hepatitis and gastritis, leading to cancer.

• ALGAE
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• v.29 no.2
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• pp.165-174
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• 2014

Ecklonia cava is a common edible brown algae that is plentiful in Jeju Island of Republic of Korea. Polyphenols from E. cava have strong anti-inflammatory activity. However, a large number of the by-products from E. cava processing are discarded. In the present study, to utilize these by-products, we assessed the anti-inflammatory activity of the polyphenol-rich fraction (PRF) from E. cava processing by-product (EPB) in lipopolysaccharide (LPS)-induced RAW264.7 macrophage cells. Four compounds, namely eckol, eckstolonol, dieckol, and phlorofucofuroeckol-A, were isolated and identified from PRF. We found that PRF suppressed the production of nitric oxide (NO), inducible nitric oxide synthase, and cyclooxygenase-2 in the LPS-induced cells. Furthermore, the protective effect of PRF was investigated in vivo in LPS-stimulated inflammation zebrafish model. PRF had a protective effect against LPS-stimulated toxicity in zebrafish embryos. In addition, PRF inhibited LPS-stimulated reactive oxygen species and NO generation. According to the results, PRF isolated from EPB could be used as a beneficial anti-inflammatory agent, instead of discard.

• Fisheries and Aquatic Sciences
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• v.21 no.7
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• pp.18.1-18.6
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• 2018

Background: Cutaneous bacterial pathogens including Staphylococcus aureus, Staphylococcus epidermidis, Pseudomonas aeruginosa, and Propionibacterium acnes are often involved in acne vulgaris. The currently available therapeutic option for these skin pathogens is an antibiotic treatment, resulting in the emergence of antibiotic-resistant bacteria. The objective of this study was to discover an alternative antibacterial agent with lower side effect from marine algae. Results: The ethanolic extract of edible brown algae Ishige okamurae exhibits potent antibacterial activity against cutaneous bacterial pathogens. Among the ethanol soluble fractions, the n-hexane (Hexane)-soluble fraction exhibited the strongest antibacterial activity against the pathogens with MIC values ranging 64 to $512{\mu}g/mL$ and with minimum bactericidal concentration values ranging 256 to $2048{\mu}g/mL$. Furthermore, the combination with Hexane fraction and antibiotics (ceftazidime, ciprofloxacin, and meropenem) exhibited synergistic effect. Conclusion: This study revealed that the I. okamurae extract exhibited a synergistic antibacterial effect against acnerelated cutaneous bacterial pathogens acquired antibiotic resistant. Thus, the results of the present study suggested that the edible seaweed extract will be a promising antibacterial therapeutic agent against antibiotic-human skin pathogens and its infections.

• ALGAE
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• v.20 no.1
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• pp.69-75
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• 2005

Hizikia fusiformis is well known edible brown seaweed both in Korea and Japan. It has been intensively studied due to its pronounced health benefits. In this study, the radical scavenging (antioxidative) activities of its hydrophilic phlorotannin constituents were studied. An aqueous extract/original extract (OE) of H. fusiformis was initially prepared with heat, enzymes and pH control treatments. Then the original extract was further fractionated (with methylene chloride and methanol) and crude hydrophilic phlorotannin extract (CHPE) was prepared. The radical scavenging activities of both OE and CHPE were determined by using electron spin resonance (ESR) spectrophotometric assays such as 1,1-diphenyl-2-picrylhydrazyl (DPPH), hydroxyl and alkyl radical assays. The CHPE reported significantly (p < 0.05) higher total phenolic (phlorotannins) content (1.23 mg ${\cdot}ml^{-1}$) than that of the OE (0.21 mg ${\cdot}ml^{-1}$). Both OE and CHPE have reported good radical scavenging activities and those activities were dose-dependent. The CHPE have demonstrated significantly higher radical scavenging activities than that of the OE. In comparison, the DPPH radical (6 $\times$ 10$^{-5}$ M) scavenging activities of all the CHPE concentrations (0.25, 0.5 and 1 mg ${\cdot}ml^{-1}$) tested were significantly higher (37.3, 78.2 and 91.6%, respectively) than that of the OE counterparts (11.4, 34.6 and 61.7%, respectively). Alkyl radical scavenging percentages of CHPE at 0.0625, 0.125, 0.25 and 0.5 mg${\cdot}ml^{-1}$ were significantly higher (34.3, 69.2, 80.4 and 88.7%, respectively) than that of the OE (16.6, 41.4, 62.3 and 77.4%, respectively). The percentages of hydroxyl radical scavenging activities of CHPE at the concentrations of 0.25, 0.5 and 1 mg ${\cdot}ml^{-1}$ were 32.5, 59.4 and 84.2 % respectively. Moreover, the hydroxyl radical scavenging activity of OE was quite lower than that of the CHPE. Therefore, these results suggest that the hydrophilic phlorotannins of H. fusiformis are potential radical scavengers thus, a great source of antioxidative nutraceuticles.