• Preventive Nutrition and Food Science
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• v.12 no.2
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• pp.65-73
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• 2007

Sargassum fulvellum, a marine brown alga, is a popular low priced edible plant in Korean markets. The polysaccharide fraction of the alga was separated and investigated for its radical scavenging activities and the results compared with those of commercial fucoidans (Fucus vesiculosus and Undaria pinnatifida), BHA and ${\alpha}$-tocopherol. The polysaccharide fraction of S. fulvellum showed a promising DPPH radical scavenging activity than did other fucoidans. Moreover, the sample exhibited a dose-dependent activity on hydrogen peroxide scavenging activity in the V79-4 cell line. Interestingly, all the tested polysaccharide counterparts were more potent NO. scavengers than were the commercial antioxidants, BHA and ${\alpha}$-tocopherol. The sulfated polysaccharide of S. fulvellum had an approximate molecular weight of 529 kDa and mainly consisted of fucose and galactose, and minor amounts of mannose, rhamnose and xylose.

• BMB Reports
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• v.43 no.1
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• pp.62-68
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• 2010

Matrix Metalloproteinases (MMPs) are a family of zinc-endopeptidases which can degrade extracellular matrix (ECM) components and play important roles in a variety of biological and pathological processes. 6,6'-bieckol isolated and characterized from an edible marine brown alga Ecklonia cava (EC), according to the comprehensive spectral analysis of MS and NMR data. Here the influence of 6,6'-bieckol on expressions of MMPs was examined by zymography and western blot analysis via human fibrosarcoma cell line (HT1080). It is shown that 6,6'-bieckol significantly down regulated the expressions of MMP-2 and -9 in dose-dependent manner. The influence of 6,6'-bieckol on the cell viability and cell behavior of HT1080 cells were also investigated, our dates shown that it suppressed the migration and 3D culture in HT1080 cells. Meanwhile, we explored several signal pathways which may contribute to this process, and found the suppressing of MMPs expressions in HT1080 cells might be due to the suppression of NF-${\kappa}B$ signal pathway.

• Ocean Science Journal
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• v.42 no.3
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• pp.165-170
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• 2007

The structure of the nematodes communities has been studied in the sediments on two sites located outside and under the layer of Ahnfeltia tobuchiensis (Kanno and Matsubara 1932; Makijenko 1970). Bottom sediments at the stations were represented by sands with a different degree of silting. Specific structure of nematodes at the stations was significantly different under the similar environmental conditions (water depth, dissolved oxygen saturation, salinity, temperature of the bottom layer and organic carbon content inside of the sediment). Nematodes dominated (75.7 %) in meiobenthos community under the layer of A. tobuchiensis where concentration of silt particles was 12 %. Representatives of the family Comesomatidae were dominant. Low index of species diversity and high Simpson domination index were detected in this community. Under a layer of A. tobuchiensis with the thickness of 30 cm concentration of the silt particles was 5.39 %; nematodes density was low and made 32.1 % of the general density of meiobenthos. Species of the families Xyalidae and Monoposthiidae were dominant. Outside of A. tobuchiensis, field percentage of silt particles was minimal (3.1 %) and representatives of families Cyatholaimidae and Axonolaimidae dominated. The specific structure of nematodes in this type of the ground is characterized by high index of species diversity and low level of domination.

• Journal of Microbiology and Biotechnology
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• v.18 no.4
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• pp.676-681
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• 2008

To obtain a natural antioxidant from a marine biomass, this study investigated the antioxidative activity of methanolic extracts from the marine brown alga, Ishige okamurae collected off Jeju Island. A potent free radical scavenging activity was detected in the ethyl acetate fraction containing polyphenolic compounds, and the potent antioxidant elucidated as a kind of phlorotannin, diphlorethohydroxycarmalol, by NMR and mass spectroscopic data. The free radical scavenging activities of the diphlorethohydroxycarmalol were investigated in relation to 1,1-diphenyl-2-picrylhydrazyl (DPPH), alkyl, and hydroxyl radicals using an electron spin resonance (ESR) system. The diphlorethohydroxycarmalol was found to scavenge DPPH ($IC_{50}=3.41{\mu}M$) and alkyl ($IC_{50}=4.92{\mu}M$) radicals more effectively than the commercial antioxidant, ascorbic acid. Therefore, these results present diphlorethohydroxycarmalol as a new phlorotannin with a potent antioxidative activity that could be useful in cosmetics, foods, and pharmaceuticals.

• Korean Journal of Environmental Biology
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• v.37 no.4
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• pp.672-681
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• 2019

The ecological characteristics of Sargassum macrocarpum, an ecologically and commercially valuable brown alga, were investigated from May 2018 to June 2019 in Jeju Island, Korea. The S. macrocarpum population formed patches at depths of 3-5 m. Growth in the length of the alga reached a maximum of 135.3±20.0 cm in June. The weight of the alga reached a maximum of 3.6±2.1 kg·wet-wt in May. The mean density and biomass of S. macrocarpum was 4.5 individuals·m^-2 and 4.6 kg·wet-wt.·m^-2 in their habitat. Receptacles were observed from April to August and egg release was detected from June to July when the seawater temperatures were 19.3-22.9℃. The developmental initiation of thalli occurred at temperatures above 14.1℃ and maturation required approximately 726.3 degree-days. The reproductive allocation of this alga, calculated from the reproductive frond length(RFL) and reproductive frond weight(RFW) indices to the whole length and weight, reached a maximum of 69.3% in June. The growth and maturation patterns of S. macrocarpum could be divided into vegetative growth (October-January), maturity preparation (February-April), maturation (May-June), egg release (June-July), and resting period (August-September). This was the first study to examine an S. macrocarpum population throughout the entire year in a natural habitat in Jeju Island, Korea.

• Proceedings of the Korean Aquaculture Society Conference
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• 2004.05a
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• pp.154-155
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• 2004

• Proceedings of the Korean Aquaculture Society Conference
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• 2004.05a
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• pp.152-153
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• 2004

• Proceedings of the Zoological Society Korea Conference
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• 2000.10a
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• pp.200.1-200
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• 2000

No Abstract, See Full Text

• Proceedings of the Botanical Society of Korea Conference
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• 2000.04a
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• pp.26-26
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• 2000

• Applied Chemistry for Engineering
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• v.21 no.6
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• pp.659-663
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• 2010

Microalgae has been seen all over the seawater and several species are used for human food. Specially, Nannochloropsis oculata, a photosynthetic microalgae, has been focused for a vast array of valuable nutritious compounds. In order to find high mass Nannochloropsis oculata culture conditions, some of important growth factors of pH, temperature, culture media, and $CO_2$ effect were tested. The optimal growth condition was found to be as follows : 3% artificial seawater, initial pH 8.5, and temperature $25^{\circ}C$. The alga mass and chlorophyll content were dramatically increased by applying 5% flue $CO_2$ gas (1.50 g/L algae in a continuous $CO_2$ flue; 0.76 g/L alga without $CO_2$). It was shown that the chlorophyll biosynthesis was also closely associated with alga growth.