• ALGAE
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• v.28 no.4
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• pp.365-369
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• 2013

The objective of this study was to determine the optimal blade size and timing to transplant seed-stock of Ecklonia cava Kjellman onto the reef structure. We used the modified artificial stepped reef structure. A total of 14 units (3.0 m length ${\times}$ 3.5 m width ${\times}$ 1.1 m height) were deployed 7-8 m deep under the water to examine the optimal blade size and timing to transplant seed-stock of E. cava onto the structures. Sporophytes of E. cava <1 cm in length were all died within 1 month of transplantation. The blades of 5-10 cm in length which were transplanted in March 2007 survived and grew well on the artificial reefs. Growth rates of 5-10 cm size class were higher than those of longer blade sporophytes (20-30 cm size class, transplanted in April) while the survival rates showed no difference between the classes of blade size. Both classes of 5-10 and 20-30 cm in length grew until July, and a reduction in size had occurred in September. These results indicate the importance of the blade size of E. cava and timing for successful transplantation of the seaweed on artificial reef structures.

• 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.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.42 no.5
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• pp.523-526
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• 2009

Biodegradable polybutylene succinate (BPS) multifilament were designed to degrade upon disposal by the action of afforestration of Ecklonia cava. Matured thalli of E. cava were collected at Jeju for zoospore collection and the substrate for zoospores were BPS multifilament (12 mm, 500 Td/96). The materials were made as nets of $1\;m^2$ with a cross stripes of 10 cm. The unit biodegradable nets bearing germlings of E. cava was moved into Wando where the place is conducting intensive seaweed cultivation in Korea for 5 months of nursery culture until they grew to 10 cm in length after which the nets were transplanted into the sea bed at Jeju at a depth of 12 m and the algal growth was monitored from May 2007 to December 2008. This is the first instance of using the BPS materials for seaweed afforestation to avoid any environmental problems.

• Fisheries and Aquatic Sciences
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• v.14 no.3
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• pp.198-204
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• 2011

The brown seaweed Ecklonia cava is known to be a rich source of phlorotannins that have diverse biological activities. Among the phlorotannins in E. cava, concentrations of dieckol and phlorofucofuroeckol-A, which were identified as major active components, were determined in different parts of the tissue. We compared the efficacy of different pretreatments for their extraction. A high-performance liquid chromatography (HPLC) method to determine phlorotannin concentrations showed good accuracy (92.64 and 94.02%, respectively), precision (3.92 and 3.94%, respectively), and linearity (r>0.996). Mature thalli contained 1.5-fold more dieckol (1.82 mg/g-dry tissue) than young thalli. In the tissues of E. cava, blade tissue contained more phlorotannins than the stipe or holdfast. Among differently dried thalli, approximately 90% or more dieckol and phlorofucofuroeckol-A were extracted from shadow-dried tissue as compared with lyophilized tissue. In sun-dried and oven-dried thalli, approximately 60% of the phlorotannins were extracted. Thalli washed with fresh water, boiled thalli, and steamed thalli showed reduced extraction of the compounds.

• Nutrition Research and Practice
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• v.5 no.2
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• pp.93-100
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• 2011

Inhibition of angiotensin I-converting enzyme (ACE) activity is the most common mechanism underlying the lowering of blood pressure. In the present study, five organic extracts of a marine brown seaweed Ecklonia cava were prepared by using ethanol, ethyl acetate, chloroform, hexane, and diethyl ether as solvents, which were then tested for their potential ACE inhibitory activities. Ethanol extract showed the strongest ACE inhibitory activity with an $IC_{50}$ value of 0.96 mg/ml. Five kinds of phlorotannins, phloroglucinol, triphlorethol-A, eckol, dieckol, and eckstolonol, were isolated from ethanol extract of E. cava, which exhibited potential ACE inhibition. Dieckol was the most potent ACE inhibitor and was found to be a non-competitive inhibitor against ACE according to Lineweaver-Burk plots. Dieckol had an inducible effect on the production of NO in EAhy926 cells without having cytotoxic effect. The results of this study indicate that E. cava could be a potential source of phlorotalnnins with ACE inhibitory activity for utilization in production of functional foods.

• Journal of Fisheries and Marine Sciences Education
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• v.26 no.1
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• pp.34-48
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• 2014

Marine algal assemblages on the artificial reefs at three stations (Haengwon, Geumneung, Pyoseon in Jeju-do) and the growth pattern of Ecklonia cava with water depth were studied before and after rocky cleaning. Nine algal species occurred at three artificial reefs before rocky cleaning in July 2012, however, 19 algal species were found at three artificial reefs after rocky cleaning in July 2013. In particular, 13 of 19 species in 2013 were replaced by different species which were not found in July 2012. Algal biomass rapidly increased in July 2013 after rocky cleaning. The nMDS plot based on the presence and absence data of macro-algal assemblages on the artificial reefs showed that the species compositions between artificial reefs were similar to each other before rocky cleaning operations in July of 2012. However, after rocky cleaning, the species composition of macro-algal assemblages in Haengwon region was similar to that in Pyoseon region while that in Geumneung region was different to those in Haengwon and Pyseon regions in July 2013. It is needed to clarify the suitable water depth for transplantation of perennial Phaeophyta E. cava. According to the data on seasonal changes in total length, total weight, blade length, blade width, blade weight of E. cava, it began to grow rapidly from April and reached to the maximum value in June, and then degeneration of the blade occurred in July and continued to early August. Although the total length of E. cava at 10m water depth was larger than those at 5 m and 15 m water depths, there was no significant difference statistically among water depths by ANOVA test. However, in the values of total weight, blade length, blade width, and blade weight, the growth patterns at 5 m water depth were larger than those at 10 m and 15 m. Thus, it is assumed that the most suitable water depth for transplantation and its maximum growth and effective release of zoospores of E. cava will be 7~10 m water depth.

• Korean Journal of Environmental Biology
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• v.38 no.3
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• pp.404-415
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• 2020

We investigated the seasonal variations in growth and physiological responses of the kelp species Ecklonia cava to different nitrogen sources to establish indoor culture conditions for mass production. Ecklonia cava was cultivated for 10 days in 16 combinations of seawater temperatures (15, 17, 21, and 25℃) and different nitrogen sources (control; NH-NH₄⁺ 100 μM; NO-NO₃^- 100 μM; and NHNO-NH₄⁺ 50 μM+NO₃^- 50 μM). The growth and growth rate of the blade were affected by temperature. The mean fresh weight and area-based daily growth rate were the highest (5.8±0.5 and 6.6±0.5% day^-1, respectively) at 15℃ and the lowest (2.2±0.2 and 3.0±0.3% day^-1, respectively) at 25℃. The daily growth rate was the highest in the NH and NO treatments and lowest in the control. The nitrate reductase activity of E. cava varied with water temperature (season). The highest activity was in the control (1.32±0.10 μmol NO₂^- g^-1 dry weight h^-1) and the lowest was in the NH treatment (0.25±0.02 μmol NO₂^- g^-1 dry weight h^-1). The photosynthetic pigment concentrations reached a maximum value in the NHNO treatment and a minimum value in the control. These results showed that water temperature played an important role in the cultivation of E. cava and that a single supply of NH₄⁺ or NO₃^- may induce the accelerated growth of E. cava. The growth and physiological responses of E. cava to different nitrogen sources during each season provide valuable information for determining the optimal nitrogen source in E. cava cultivation under indoor conditions.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.47 no.4
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• pp.363-369
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• 2014

Obesity is a worldwide problem that contributes to serious diseases, including diabetes, hypertension, and atherosclerosis. Recently, much research has examined functional natural materials and their anti-obesity activity. This study investigated the effect of enzyme-treated Ecklonia cava extracts on mice fed a high fat diet. To test the anti-obesity effects of a diet containing the enzyme-treated E. cava extracts (EEc), C57BL/6NTacSam mice were divided into six groups : normal diet (ND), high-fat diet (HFD), high-fat with Garcinia extract diet (GHD), and three high-fat with EEc diet (EHD250, EHD500, and EHD1000) groups. After 9 weeks, body weight was increased significantly in the HFD group compared to all of the EHD groups, and the weights of the liver, perirenal fat and epididymal fat paralleled the increase in body weight. The serum GOT, GPT, triglyceride, total cholesterol, and LDL-cholesterol levels were lower in the EHD1000 group than in the HFD group. The glucose and leptin concentrations were lowest in the EHD1000 group and C/EBP family expression was decreased in a dose-dependent manner. These results indicate that E. cava extracts not only have anti-oxidation functions but also anti-obesity effects.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.48 no.3
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• pp.301-307
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• 2015

Phlorotannins and marine algal polyphenols, including dieckol, 6,6-bieckol, phloroglucinol, phlorofucofuroeckol-A, and eckol, were isolated from brown seaweeds. These compounds have beneficial bioactivities, and Ecklonia cava has become widely used for the extraction and isolation of phlorotannins. Eckol, in particular, has been to shown to have antioxidant, anti-inflammatory, anticoagulatory, and photoprotective properties. However, due to its low abundance in weaweed, the isolation and purification of eckol are difficult. Its limited availability renders the isolation and purification of eckol labor-intensive processes. Centrifugal partition chromatography (CPC) is an efficient technique for the isolation and purification of eckol. In this study, eckol was isolated from the ethyl acetate fraction of the 70% ethanol extract of E. cava using CPC with a two-phase solvent system of a n-hexane:EtOAc:methanol:water (2:8:3:7, v/v) solution. The purity and anti-inflammatory activity of the isolated eckol were verified by high-performance liquid chromatography and by assaying lipopolysaccharide-induced inflammatory responses in an immortalized murine BV2 microglial cell line, respectively. In conclusion, CPC is a useful technique for simple and efficient isolation of eckol from E. cava.

• Proceedings of the Korean Society of Life Science Conference
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• 2008.10a
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• pp.84.1-84.1
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• 2008