• Natural Product Sciences
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• 제9권4호
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• pp.232-234
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• 2003

A new glycerol ether has been isolated from a marine sponge Stelletta sp. By bioactivity-guided fractionation. The structure was established on the basis of NMR and MS analyses. The compound was evaluated for cytotoxicity against a small panel of five human tumor cell lines and exhibited significant cytotoxicity.

• 한국양식학회지
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• 제15권3호
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• pp.139-143
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• 2002

해면동물 P. incrustans 시료를 거제도 해금강 연안에서 SCUBA 다이빙에 의하여 채집하였으며, 채집한 시료를 메탄올로 반복해서 추출한 후에 다시 dichloromethane으로 반복 추출하였다 얻어진 유기 조추출물을 n-butanol과 물을 이용하여 분배한 후 n-butanol 층은 다시 15% 메탄올 수용액층과 n-hexane으로 분배하였다. n-Hexane 분배 분획에 대한 silica flash chromatography와 이렇게 얻어진 크로마토그래피 분획에 대한 반복적인 HPLC에 의해서 saringosterol을 분리할 수 있었으며, 이차원적 핵자기 공명 분광기법에 의하여 이 화합물을 구성하는 탄소원자들의 위치를 정확히 지정할 수 있었다. 이 스테로이드는 아직까지 우리나라에서 채집한 해양생물에서는 분리된 적이 없으며 이 화합물의 탄소 위치에 대한 정확한 지정도 처음으로 이루어졌다.

• Ocean and Polar Research
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• 제38권4호
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• pp.287-294
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• 2016

Marine sponges have been a remarkably rich source of pharmacologically active and structurally diverse natural products. As a part of our continuing search for novel secondary metabolites of biomedical importance from marine invertebrate, we encountered the sponge Lipastrotethya sp. from Chuuk, Micronesia. The crude organic extract of this animal exhibited considerable cytotoxicity against the K562 cell line. Guided by the $^1H$ NMR analysis, flash chromatography of the crude extract followed by HPLC yielded a new triterpene glycoside, along with ten known saponins of the sarasinoside class. The structure of this new compound was determined by combined spectroscopic methods such as COSY, HSQC and HMBC experiment. Among these metabolites, six compounds exhibited moderate cytotoxicity against ACHN, MDA-MB-231, NCI-H23 and NUGC-3 cell lines.

• Natural Product Sciences
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• 제5권4호
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• pp.177-180
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• 1999

The ethanolic extracts of two shallow water sponge species collected from the Aegean Sea afforded thirteen terpenoids in total, two of which were determined to be new. The structure elucidation of the terpenoids was carried out by spectroscopic techniques and comparison with related authentic compounds. The terpenoids have also been assayed for antibacterial activity. This is the first report about the metabolites isolated from the marine sponges of the Aegean Sea in Turkey.

• Natural Product Sciences
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• 제21권4호
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• pp.237-239
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• 2015

Sarcotragin C (1), a new sesterterpene metabolite was isolated from a Sarcotragus sp. sponge collected from Chuja Island, Korea. On the basis of the combined spectroscopic analyses, the structure of this compound was determined to be a linear norsesterterpene containing a leucine-derived ${\gamma}-lactam$ moiety. This compound exhibited moderate cytotoxicity against K562 and A549 cell-lines.

• Bulletin of the Korean Chemical Society
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• 제28권6호
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• pp.990-994
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• 2007

Bioassay-guided fractionation of the MeOH extract from the sponge Discodermia calyx collected off the coast of Jeju Island, South Korea, led to the isolation of a polyketide, icadamide C (1), along with previously reported theopederin K (3). Structure elucidation was performed by a combination of high resolution mass and 2D-NMR (principally COSY, HMBC, HSQC, and NOESY) spectroscopy. Stereochemistry of compound 1 was determined as 2R*, 3R*, 6R*, 10S*, 11S*, 12R*, 13S*, 15R* and 2'S by NMR data and Marfey analysis. Isolated metabolites displayed potent cytotoxic activity against a small panel of five human solid tumor cell lines with ED50 values of less than 0.1 μg/mL.

• Journal of Microbiology and Biotechnology
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• 제19권3호
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• pp.229-237
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• 2009

Among 12 marine bacterial strains from the China coast that exhibited interesting bioactivity (positive for both antimicrobial and cytotoxic activities), only four strains, namely, NJ6-3-1, NJ6-3-2, NB-6, and YTHM-17, had a KS domain or A domain when screened for PKS and NRPS genes using a PCR. Interestingly, two of these strains belonging to Pseudoalteromonas and associated with the marine sponge Hymeniacidon perleve were positive for both PKS and NRPS, whereas the other two strains of Pseudoalteromonas did not have a PKS or NRPS gene. A molecular phylogeny analysis and DGGE analysis of the Pseudoalteromonas sp. indicated that they had a specific affinity with the host marine sponge Hymeniacidon perleve. Furthermore, an analysis of a partial sequence of Pseudoalteromonas sp. NJ6-3-2 isolated from the marine sponge Hymeniacidon perleve obtained from genomic walking using a computational approach indicated a relatively complete PKS module including auxiliary domains (DH, KR, and Cy).

• Proceedings of the National Institute of Ecology of the Republic of Korea
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• 제2권1호
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• pp.21-25
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• 2021

We measured the sizes of microstructures and the reflectance of blue feathers in the Common Kingfisher (Alcedo atthis). The colors were mainly produced in the barbs, which were composed of keratin sponge layers with air spaces and melanin rods. The reflectance spectra of back and tail feathers of the Common Kingfisher showed a peak with a broad plateau in the visible wavelength, whereas those of the wing feathers showed peaks in ultraviolet and visible and short-wavelengths. Moreover, the reflectance of back and tail feathers was higher than that of wing feathers. The blue color of the feathers comes from the keratin sponge layer due to coherent scattering. The back and tail feathers are composed of the keratin sponge layer only, and the wing feathers are composed of the keratin sponge layer and the keratin honeycomb structure. Due to the difference in these structures, it supposed that the reflectance is different. Determining why the reflectance spectra of the back and tail feathers were flattened will require further study.

• 한국산학기술학회논문지
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• 제9권6호
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• pp.1775-1781
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• 2008

가교제의 종류가 헬리콥터 연료탱크의 자기밀폐층 소재로 적용시키기 위한 천연고무 스폰지의 팽윤에 미치는 효과를 조사하였다. 과산화물과 황을 섞은 가교방식과 과산화물에 의한 가교방식을 채택하였다. 천연고무 콤파운드를 Kneader와 Roll-Mill을 활용하여 제조하고, 고압조건의 프레스에서 부분 가교시킨 후 대기압의 금형에서 발포와 완전가교를 실시하였다. 얻어진 스폰지의 겉보기밀도를 측정하고 스폰지의 셀구조를 주사전자현미경을 통하여 관찰하였다. 톨루엔, 이소옥탄과 항공유를 사용하여 실온에서 팽윤실험을 실시하였다. 용매에 2분 동안 침적 후 얻어지는 부피팽윤비 값은 과산화물 가교에 의한 천연고무 스폰지가 비슷한 양의 황과 과산화물의 혼합가교에 의한 경우보다 높았다. 스폰지의 겉보기밀도와 셀구조는 과산화물 함량에 매우 민감하였으며 이는 또한 천연고무 스폰지의 팽윤거동에 영향을 미쳤다. 천연고무 스폰지가 연료와 접촉하여 신속한 팽윤이 얻어지기 위하여 금형에서 동시에 발생하는 두 가지 반응인 발포제의 분해반응과 천연고무의 가교반응을 적절히 조절하는 것이 중요하다.

• 한국자기공명학회논문지
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• 제10권2호
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• pp.188-196
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• 2006

A known theonellapeptolide Ie, previously reported in other research group, was isolated from the methanolic extract of the Philippine sponge Theonella swinhoei. The planar structure of this compound was determined on the basis of NMR methods including HMBC and selective HMBC experiments. This is fast and efficient for the dereplication of natural products compared with the MS studies of fragments obtained from complete and partial hydrolysis. The sequence of thirteen amino acids including six N-methyl amino acids in the compound was clearly determined from correlations of extensive HMBC experiments.