• Archives of Pharmacal Research
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• 제27권12호
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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.

• Journal of Microbiology
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• 제44권6호
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• pp.694-698
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• 2006

Several marine bacterial strains were isolated from Undaria pinnatifida (Miyok in Korean). Sixty-six strains were isolated on R2A agar media at $10^{\circ}C$ and identified by a phylogenetic analysis of the 16S rRNA gene sequences. They were grouped into 10 different sequence types based on the initial sequence analysis of the 5' domain of the gene (approximately 500 bp). Full sequences of 16S rRNA gene, were obtained from one strain in each sequence type and the species-affiliation was determined using phylogenetic and sequence similarity analyses. The results of the analyses indicated that they were closely related to Psychrobacter aquimaris, P. celer, P. nivimaris, P. pulmonis, Psychromonas arctica or Bacillus psychrodurans. These bacteria are marine or psychrotrophic bacteria. Because the sporophytes of U. pinnatifida are cultured on the costal area during winter, the U. pinnatifida-associated bacteria appeared to grow at low temperatures. U. pinnatifida sporophytes can be a good source for the isolation of psychrotrophic bacteria.

• 생약학회지
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• 제37권2호통권145호
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• pp.92-96
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• 2006

Six phlorotannins were isolated from Ecklonia cava, a brown alga belonging to Alariaceae, collected offshore Jeju Island. Among the phlorotannins, dieckol showed strong elastase inhibition and hyaluronidase ingibition.

• 한국환경성돌연변이발암원학회지
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• 제26권4호
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• pp.113-115
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• 2006

Ecklonia cava is a brown alga(Laminariaceae) that is abundant in the subtidal regions of Jeju island in Korea. Phlorotannins were identified to be responsible for the biological activities in Ecklonia species. In the present study, triphlorethol-A, a phlorotannin, was isolated from Ecklonia cava and its anticancer properties were investigated. Triphlorethol-A was investigated whether it may show cytotoxicity effects against U937, HeLa, NCI-H460 and MCF-7 cancer cells by MTT test. As a result, triphlorethol-A did not show cytotoxic effects against tested four cell lines.

• 대한약학회:학술대회논문집
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• 대한약학회 2002년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2
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• pp.375.3-375.3
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• 2002

In continuing search for BChE-inhibitory compounds from Korean marine algae. we found a highly potent inhibitory activity in the methanolic extract of Sargassum species. After partition of the MeOH extract between $CHCl_3$ and 30% MeOH. the former layer was subjected to a series of ODS flash chromatography. silica column chromatography. and preparative TLC to afford three compounds (1-3). Detailed structural elucidation of them is in progress. Compound 1 showed potent BChE-inhibitory activity with $IC_{50}$ values of 11 ng/mL. (omitted)

• 생명과학회지
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• 제20권12호
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• pp.1807-1811
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• 2010

갈조류에서 에스트로겐 활성소재를 평가하기 위하여 in vitro 검출시스템을 사용하여 에스트로겐 효과를 가지는 분획을 검증하였다. 각각의 갈조류의 분획물들은 에탄올 추출로부터 물, 헥산, 부탄올 그리고 메탄올의 용매를 이용한 분획과정을 통해 제조하였다. 갈조류들의 수층 분획물에서 가장 높은 에스트로겐 활성을 보였다. 미역과 다시마의 수층 분획물들은 $500\;{\mu}g/ml$의 농도에서 $10^{-7}\;M$의 표준물질($17{\beta}$-estradiol)과 비슷한 활성을 보였으며, 곰피와 돌자반의 수층 분획물들은 $500\;{\mu}g/ml$의 농도에서 $10^{-8}\;M$의 표준물질보다 높은 활성을 보였다. 이 연구의 결과로 갈조류인 미역, 다시마, 곰피 및 돌자반의 수층 분획물에 에스트로겐 대체 작용을 할 수 있는 성분이 포함되어 있는 것을 확인하였으며, 이를 이용하여 폐경기 장애를 예방할 수 있는 에스트로겐 활성소재의 개발이 가능할 것으로 기대된다.

• 한국수산과학회지
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• 제38권2호
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• pp.112-117
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• 2005

Sargassum fulvellum (Turner) C. Agardh, an edible brown alga is farmed commercially by sexual reproduction and vegetative regeneration. Investigations were made on the phenology, abundance and maturity of reproductive structures in mature fronds, egg release and young germling development under different light conditions (20, 50, 80 and $100{\mu}mol/m^2/s$) and temperatures (5, 10, 15, 20 and $25^{\circ}C$). Monthly sampling was carried out by SCUBA diving at Chungsando on the southwestern coast of Korea from September 2002 to August 2003. The Maximum length of thalli was $104.6{\pm}20.7{\cal}cm$ in March 2003 when the water temperature was $9.0^{\circ}C$ and minimum was $0.8{\pm}0.5{\cal}cm$ in June when the water temperature was $19.5^{\circ}C$. Receptacle formation was observed from February to April. The peak period of egg release for this alga was in April when the water temperature was about $10^{\circ}C$ in nature. In the culture regimes of temperature and irradiance, the egg release of the excised female receptacle was highly affected by temperature. The maximum rate of egg release was $96.7{\pm}5.8{\%}$ under $20^{\circ}C$ and $80{\mu}mol/m^2/s$. The maximum length of young germlings was $3.9{\pm}0.2{\cal}mm$ after 35 days culture under $15^{\circ}C$ and $80{\mu}mol/m^2/s$.

• 한국양식학회지
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• 제11권4호
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• pp.465-474
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• 1998

참전복(Haliotis discus hannai) 양성과정중 치패단계에서 발생된 패각 괴사증의 조사결과는 다음과 같다. 괴사된 전복패각에서 간균 형태(rod type)와 이질세포를 갖는 남조류가 관찰되었다. 그러나 주사전자현미경(SEM)의 자료에 근거하면 패각과 사증의 원인생물은 천공성 남조류, Mastigocoleus sp.로 나타났다. 천공성 남조류에 감염된 전복의 패각은 녹색에서 회백색으로 탈색되었고, 4~6번째 호흡공은 부서지기 쉬운 상태가 되었다. 양성 60일 후, 패각 괴사증은 갈색의 작은 집락이 산재되어있는 호흡공에서 주로 발생하였으며, 양성 후 3년까지 지속되었다. 이러한 패각 괴사증은 바다 채롱식 양식장에서 보다는 육상 수조식 양식장에서 주로 발생하였으며, 참전복의 성장에 커다란 영향을 미친 결과 3년산 참전복의 각장이 16mm였다.

• 한국양식학회지
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• 제19권1호
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• pp.33-39
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• 2006

Anticoagulant activities of a fermented edible brown alga, Laminaria ochotensis was investigated. L. ochotensis was fermented with 15% sugar (w/v) at $25^{\circ}C$ for 10 weeks. Anticoagulant activity was measured from the supernatant of algal mixture at biweekly intervals up to $10^{th}$ week by activated partial thromboplastin (APTT), prothrombin time (PT) and thrombin time (TT) assay using citrated human plasma. Sample having high APTT activity $(6^{th}\;week)$ was filtered, ethanol precipitated and freeze-dried. The polysaccharide compound having anticoagulant activity was purified by DEAE ion exchange chromatography followed by Sepharose-4B gel filtration chromatography. Anticoagulant activity, polysaccharide concentration, and heparin like activity were determined for the collected fractions by APTT, $phenol-H_2SO_4$, and glycosaminoglycan assay, respectively. The anticoagulant activity assay showed that the activity was increased up to $6^{th}$ week, and decreased thereafter. The concentration of our purified compound was $31.0{\mu}g/ml$ and showed higher APTT activity than commercial heparin. At the same concentration of $31.0{\mu}g/ml$, the heparin showed 186.5 sec activity while our purified compound showed an activity of 386 sec. Single spot on agarose gel electrophoresis showed that the compound was purified and polyacrylamide gel electrophoresis (PAGE) results revealed that the molecular mass of the purified polysaccharide compound was between 60 and 500 kDa. Therapeutic interest of the algal polysaccharide as an anticoagulant has recently been in highlighted. This purified anticoagulant compound from fermented L. ochotensis can be used as a model for anticoagulant agent or could be developed as an anticoagulant agent. This study can be extended to identify the structure and chemical composition of the purified polysaccharide, and to establish a relationship between structure and the function of the identified anticoagulant compounds.

• Fisheries and Aquatic Sciences
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• 제17권2호
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• pp.209-214
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• 2014

With the continuing demand for new solutions in the development of effective and safe candidiasis therapies, we investigated the efficacy of an antifungal agent from the marine brown alga Eisenia bicyclis. The methanolic extract of E. bicyclis evinced potential antifungal activity against Candida species. The ethyl acetate (EtOAc)-soluble extract from E. bicyclis demonstrated the strongest antifungal activity against Candida species among five solvent-soluble extracts. Indeed, the EtOAc-soluble extract showed minimum inhibitory concentrations (MICs) ranging from 4 to 8 mg/mL. Furthermore, the EtOAc-soluble extract considerably reversed high-level fluconazole resistance of Candida species. The MIC values of fluconazole against Candida species decreased substantially (from 64 to $4{\mu}g/mL$) in combination with the MIC of the EtOAc-soluble extract (4 mg/mL). The fractional inhibitory concentration indices of fluconazole ranged from 0.531 to 0.625 in combination with 4, 2, or 1 mg/mL of the EtOAc-soluble extract against Candida isolates, indicating that these combinations exert a marked synergistic effect against Candida isolates. These findings imply that compounds derived from E. bicyclis can be a potential source of natural antifungal agents against Candida species.