• Korean Journal of Fisheries and Aquatic Sciences
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• v.56 no.5
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• pp.691-700
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• 2023

This study examined the seasonal variations of subtidal marine algal community structures along four sites in Jejudo Island, Korea, from February 2016 to November 2018. A total of 147 marine algal species were identified, including 13 green (8.84%), 26 brown (17.69%), and 108 red algae (73.47%). During the study period, the number of species was highest in Sagye (116 species) followed by numbers in Sinheung (98 species), Bukchon (90 species) and Sinchang (73 species). Ecklonia cava, Peyssonnelia caulifera, Synarthrophyton chejuense, Corallina aberrans and Corallina crassisima occurred at all study sites and in all seasons. The average annual biomass of marine algal flora was 746.29±88.85 g wet wt./m² and ranged from 652.25 g/m² at Sinheung to 979.91 g/m² at Sagye. The brown alga E. cava was the most dominant species, occupying 42.85% (319.80 g/m²) of the total seaweed biomass. Subdominant species were C. crassissima and Undaria pinnatifida, comprising 10.22% (76.29 g/m²) and 9.66% (72.13 g/m²), respectively. A similarity analysis showed that there were regional differences in the algal communities, with three distinct groups.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.3
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• pp.307-314
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• 2006

This study was conducted to screen in vitro angiotensin converting enzyme (ACE) inhibitory activities of methanol (MeOH) and aqueous extracts which were prepared by four different extractions-80% methanol extracts(ME) at $20^{\circ}C\;and\;70^{\circ}C$, respectively and aqueous extracts (AE) at both temperatures with the residue of the MEs-of ten marine green algae and nineteen brown algae collected along Jeju coast of Korea. Most marine brown algae extracts showed higher capacities than those of marine green algae in ACE inhibitory activity. Particularly, $70^{\circ}C$ MeOH extract (70ME) of Hizikia fusiforme showed the strongest inhibition activity (about 87%) among all the extracts. Also, 70 MEs of Enteromorpha linza, Ishige sinicola, Laminaria ochotensis, Petrospongium rugosum, Sagrassum horneri, Undaria pinnatifida and $20^{\circ}C$ MeOH extracts (20ME) of Myagropsis myagroides, Petrospongium rugosum, $20^{\circ}C$ aqueous extracts (20AE) of Codium contractum, Enteromorpha compressa, and $70^{\circ}C$ aqueous extracts (70AE) of Ecklonia cava, Petrospongium rugosum showed moderate ACE inhibitory activities more than 50% and the other extracts exhibited weak activities. On tile other hand, E. cava had the best ACE inhibitory activity among 70AEs. This indicates that 70AE of E. cava contains potential anti-ACE macromolecular. We tried to proteolytic digest 70AE of E. cava to induce production of anti-ACE peptides from E. cava 70AE. The enzymes used are five pretenses including Kojizyme, Flavourzyme, Neutrase, Alcalase, and Protamex, which are food grade-commercial enzymes from Novo Co. Flavourzyme-digest of E. cava 70AE showed the highest inhibitory activity about 90%. And the five different enzymatic digests of the E. cava 70AE ranged from 2.33 to 3.56 ${\mu}g/mL$, respectively in $IC_{50}$ values of anti-ACE activity.

• ALGAE
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• v.27 no.4
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• pp.269-281
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• 2012

Marado is a small rocky island located off the south coast of Jeju Island and acts as the first gateway of the Kuroshio Current to Korean coastal ecosystems. This island is one of the most unpolluted and well preserved sea areas around the Jeju coast. We extensively observed macroalgal assemblages of species and functional forms in the intertidal and subtidal zones through four seasons on Marado, Jeju Island, Korea to demonstrate the seasonality of vertical distribution patterns and biomass. A total of 144 species (14 Chlorophyta, 40 Phaeophyta, and 90 Rhodophyta) were identified in quadrats and were analyzed seasonally and vertically to define the variation patterns. The annual mean biomass of macroalgae was $2,932.3g\;wet\;wt\;m^{-2}$ and the highest value was recorded in spring and the lowest was in winter. The annual dominant species by biomass was Ecklonia cava followed by Sargassum fusiforme, S. macrocarpum, Amphiroa galapagensis, Chondria crassicaulis, and S. thunbergii. Obvious biomass zonation patterns of macroalgal species were detected in relation to tidal height and depth. Macroalgal biomass, diversity index (H'), and community dynamics were the highest in the shallow subtidal zone. Species number was higher in the subtidal than in the intertidal zone and similar throughout the entire subtidal zone. Our results provide revealing insights into the distribution patterns of macroalgal assemblages in an unpolluted sea area around Jeju Island.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.47 no.4
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• pp.356-362
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• 2014

Phlorotannins, the major constituent in brown algae, possess various biological activities; however, there is little information their toxicological effects. To assess the safety of phlorotannins, we investigated the acute oral toxicity of a high-purity phlorotannin preparation (PRT; total phlorotannin content 90%) in beagle dogs. Six beagle dogs (3 males, 3 females) were assigned randomly to three experimental groups. PRT was administered at oral doses of 250, 500, and 750 mg/kg by capsule. Vomiting by male and female beagles was observed with 500 and 750 mg/kg on the first day. In addition, one beagle given 750 mg/kg had soft stool and diarrhea on days 3 and 13. No deaths or abnormal clinical signs were observed during the experiment. All groups showed similar body weight gain and food consumption. Our acute toxicity study showed that PRT did not cause any toxicological effects in beagle dogs.

• Preventive Nutrition and Food Science
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• v.11 no.1
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• pp.17-24
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• 2006

Methanolic and aqueous extracts from 37 seaweed species (10 green and 27 brown seaweeds) collected from Jeju Island coast were prepared at high ($70^{\circ}C$) and room ($20^{\circ}C$) temperatures and examined for cytotoxic activity against 4 tumor cell lines: U937 (human monoblastoid leukemia cell line), HL60 (human promyelocytic leukemia cell line), HeLa (woman cervical carcinoma cell line) and CT26 (mouse colon carcinoma line). Both MeOH extracts of Desmarestia tabacoides and Dictyota dichotoma possessed strong cytotoxic activities against all the tumor cell lines tested, but the aqueous extract exhibited no activity. On the other hand Ecklonia cava showed strong cytotoxic activities for the $20^{\circ}C$ aqueous extract against the three tumor cells except HeLa cell. Sagassum coreanum and Sagassum siliquastrum $20^{\circ}C$ aqueous extracts also exhibited strong cytotoxic activities against U937, HL60, HeLa cells. Even though green seaweeds showed less activity than brown seaweeds, $20^{\circ}C$ aqueous extracts of Codium contractum and Codium fragile exhibited strong cytotoxic activities against HL60 or CT26 cells, respectively.

• Korean Journal of Food Science and Technology
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• v.9 no.3
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• pp.194-198
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• 1977

A seaweed Ecklonia cava from Jeju island was irradiated with $0.1{\sim}6\;Mrad$ of gamma-rays and the yield and viscosity characteristics of alginates from it were examined. Irradiation below 1 Mrad dose brought about a 70% increase in the yield while higher doses caused slight decreases. Viscosity behavior of alginates below 0.5 Mrad dose was not altered while the viscosity decreased markedly above 1 Mrad dose, likely due to the depolymerization.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.17 no.5
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• pp.391-397
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• 1984

The seasonal and portional variation in the composition of uronic acid of alginic acid from Eckionia cava was investigated. The sample was collected from the coast of Ieechun Illkwangmyun, Yangsangun, Kyungnam, Korea, in the period of January to December in 1982. In seasonal variation of the content of alginic acid, the range of variation was larger in the frond than in the stipe, It was the highest content in between February to April, and the lowest in between August to October, and the content was more in the stipe than in the frond. The uronic acid ratio(M/G ratio) was varied seasonaly in a relationship with the variation of the alginic acid content. The maximum M/G ratio appeared in the period of December to March and minimum May to August, and the average values of the M/G ratios in the periods were 3.08, 2.64 in the frond and 2.91, 1.39 in the stipe, respectively. Additively a year mean values were 3.22 in the frond and 2.18 in the stipe.

• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.8
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• pp.1293-1296
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• 2005

Nitrite plays an important role in the formation of carcinogenic nitrosamine. In order to effectively inhibit the formation of carcinogenic nitrosamine in food and biological systems, scavenging of residual nitrite is necessary. In screening test of nitrite-scavenging effect of seaweed, The methanol extract from Phaeophyta was more effective than those from Rhodophyta and Chlorophyta. Among the brown algae family, Laminariaceae, A. cribrosum (90.4$\%$) and E. cava (80.1$\%$), E. stolonifera (79.0$\%$) that belong to genus Ecklonia showed marked nitrite-scavenging effect at pH 1.2. Furthermore, these algae showed potent reducing power and radical scavenging activity. The nitrite-scavenging effect was correlated with level of reducing power.

• Environmental Mutagens and Carcinogens
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• v.25 no.4
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• pp.129-133
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• 2005

We investigated the cytoprotective effect of phloroglucinol, which was isolated from Ecklonia cava (brown seaweed), against oxidative stress induced cell damage in Chinese hamster lung fibroblast(V79-4) cells. Phloroglucinol was found to scavenge intracellular reactive oxygen species (ROS) generated by $\gamma-ray$ radiation. In addition, Phloroglucinol inhibited cell damage induced by radiation through scavenging ROS. Phloroglucinol increased the superoxide dismutase and glutathione peroxidase activity, Taken together, the results suggest that phloroglucinol protectes V79-4 cells against oxidative damage by enhancing the cellular antioxidant enzymes activity.

• The Korean Journal of Malacology
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• v.25 no.3
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• pp.231-236
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• 2009

This study describes biological environmental characteristics in natural habitats of Haliotis diversicolor in the coastal area of Sungsanpo located in the eastern coast of Jeju-do, Korea. The field survey was monthly conducted from May 2006 to February 2007. H. diversicolor, sea urchin, turban shell and marine algae were collected by two divers using SCUBA. The species composition of demersal fishes were seasonally investigated by fish traps in 2007. During the study period, more than 67% of H. diversicolor and sea urchin were found in the depth shallower than 5 m, and more than 64% of turban shell were found in the depth deeper than 3 m. The dominant algal species in May were generally Undaria pinnatifida, Ecklonia cava, Sargassum. spp. and coralline algae. Most of demersal fishes collected by the fish traps were wrasses which have been reported as a major predator of young abalone.