• Bulletin of the Korean Chemical Society
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• v.23 no.10
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• pp.1467-1469
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• 2002

• Bulletin of the Korean Chemical Society
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• v.15 no.7
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• pp.534-537
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• 1994

A new metabolite 2 of bastadin class and the previously reported bastadins 3 and 4 were isolated from the sponge Ianthella basta collected in Indonesia.

• Korean Journal of Pharmacognosy
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• v.35 no.3 s.138
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• pp.189-193
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• 2004

In order to find some lead compounds for the treatment of opportunistic infections of malaria and pathogenic microbes, an undescribed Indonesian sponge Agelas sp. collected at Manado, Indonesian Waters, was suggested containing active compounds. Crude ethanolic extract of the sponge exhibited significant in vitro antimalarial and antimicrobial activity against Plasmodium falciparum (D6 colne) with $IC_{5O}$ values of $8\;{\mu}/ml$ and against pathogenic microbes such as Candida albicans $(150\;{\mu}/ml)$, Cryptococcus neoformans $(<20\;{\mu}/ml)$, Staphylococcus aureus $25\;{\mu}/ml$, methicillin-resistant Staphylococcus aureus $(<20\;{\mu}/ml)$, and Pseudomonas aeruginosa $(<20\;{\mu}/ml)$. Active compound (5.0 mg) was isolated from the ethanolic extracts of the sponge and purified by using silica gel and ODS column, successively. Active compound was elucidated as dibromosceptrin $(C_{22}H_{24}Br_2N_{10}O_2)$ by detailed analysis of FTESI-MS and comparison of $^1H,\;^{13}C$, DEPT and HMQC NMR spectral data with those reported.

• Mass Spectrometry Letters
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• v.2 no.1
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• pp.8-11
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• 2011

Two types of glycerolipids [monoacylglycerols (MAG) and cyclitols] were isolated by reversed phase high-performance liquid chromatography from the methanol extracts of a marine sponge, and analyzed by fast atom bombardment mass spectrometry (FAB-MS) in positive-ion mode. FAB mass spectra of these compounds yielded protonated molecules $[M + H]^+$ and abundant sodiated molecules $[M + Na]^+$ from a mixture of 3-nitrobenzyl alcohol and NaI. The structures of these compounds were elucidated by FAB-collisional-induced dissociation (CID)-tandem mass spectrometry. We carried out collision-indused dissociation (CID) of these lipids in B/E-linked scan mode. The CID B/E-linked scan of $[M + H]^+$ and $[M + Na]^+$ precursor ions resulted in the formation of numerous characteristic product ions through a series of dissociative processes. The product ions formed by charge-remote fragmentation (CRF) provided important information for the identification of the acyl chain structure substituted at the glycerol backbone. Some of the product the ions were diagnostic for the presence of a glycerol backbone or acyl chain structure.

• Korean Journal of Pharmacognosy
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• v.44 no.3
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• pp.224-229
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• 2013

Bromotopsentin (BSM) is a bisindole alkaloid compound, which is recognized as a metabolite of the marine sponge Spongosorites sp. In this study, the antioxidant activity of BSM was investigated. The 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging assay, the trolox equivalent antioxidant capacity (TEAC) assay, the superoxide radical scavenging (NBT) assay, the lipid peroxidation and hydroxyl radical-induced DNA damage assays were carried out to evaluate the antioxidant activity of BSM. It was found that BSM had stronger scavenging activity on the stable free radical DPPH and superoxide radical than L-ascorbic acid with an $IC_{50}$ value of 62 and 64 ${\mu}M$, respectively. The TEAC value which indicated the total antioxidant capacity of BSM was about 0.8, which was also stronger than L-ascorbic acid. About 1.3 ${\mu}M$ of BSM induced 50% inhibition of lipid peroxidation. 60 nM of BSM exhibited a significant protective activity against DNA strand scission by hydroxyl radical on pBR322 DNA. Taken together, we suggest that BSM possesses strong antioxidant activity, and could be a valuable new addition to the list of anti-aging chemotherapeutic agents.

• Journal of the Korean Magnetic Resonance Society
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• v.25 no.2
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• pp.24-32
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• 2021

Two new sesterterpenes, including a known sesterterpene, were isolated from the marine sponge Haliclona sp. collected in the Gageo island, Korea. One of the new sesterterpenes (1) was an unusual compound possessing a spiroketal moiety and the other (2) represented a four ring-fused skeleton. The planar structure of compound 1 was identical to gombaspiroketals A and B isolated from the marine sponge Clathria gombawuiensis, but the configuration for the two chiral centers was different each other. On the other hand, the skeletal structure of compound 2 was similar to that of phorone A isolated from Phorbas sp. and a compound from C. gombawuiensis, except for one configuration at C-8. However, in comparing the ¹H and ¹³C NMR spectral data, the proton and carbon chemical shifts for the three compounds were almost consistent. The NOESY spectrum revealed that the C-8 configuration of 2 was reversed to that of the two reported compounds. The configuration for compound 2 was supported by quantum mechanical calculation for the carbon chemical shifts and DP4+ probability for the protons and carbons of 2.

• Journal of Food Hygiene and Safety
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• v.10 no.2
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• pp.73-79
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• 1995

Incidents of seafood and massive fish kills have been rapidly increasing in both frequency and geographical distribution and the socioeconomic impacts brought by those incidents. However, the biological origins of those marine toxins have not been well clarified. Most of the marine organisms investigated are filter-feeder, which accumulate toxins from their food and/or their symbiotic microalgae. We have examined the action on rabbit platelets of marine toxins isolated from cultured dinoflagellates and sponge collected at Okinawa. Maitotoxin (MTX) is a water-soluble toxin isolated from the cultured dinoflagellate Gambierdiscus toxicus which causes a seafood poisoning in tropical regions. Zooxanthellatoxin A (ZT-A) was isolated from exteracts of cultured symbiotic dinoflagellate Symbiodinium sp. (socalled zooxanthella) from flatworms of the genus Amphiscolops collected at Okinawan marine sponge Theonella sp. MTX caused a disaggregation and a dissolution of large aggregates. ZT-A caused a dissolution of small aggregates followed by a increment of light tranmission. TZ-A caused an initial and transient shape change followed by a sustained aggregation and a increment of large aggregates. In conclusion, marine toxins exert unique patterns on the light trasmission and the size of aggregates in rabbit platelets by their concentrations and kinds

• Microbiology and Biotechnology Letters
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• v.45 no.2
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• pp.124-132
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• 2017

Microbial secondary metabolites of marine organisms are regarded as major sources of structurally and biologically novel compounds with numerous potential uses. Sponge-microbe associations are among the most interesting sources for exploring bioactive compounds. In this study, the bacterial strain Microbulbifer sp. (127CP7-12) was isolated from the Asian marine sponge Hymeniacidon sinapium collected at an intertidal zone on the west coast of Korea. Cultured bacteria produced a violet pigment, and optimal culture conditions for violet pigment production were investigated. Maximum production of the violet pigment from the strain culture was observed under the conditions of $25^{\circ}C$, pH 6.0, and 3% NaCl. Acetone provided better extraction of the pigment from fermented broth compared with ethanol and methanol. The proposed structure of the major component in the extracted crude pigment was determined via high-performance liquid chromatography, nuclear magnetic resonance, mass spectrometry, and UV spectra analyses, which showed that the metabolite was the promising bioactive compound violacein. This study describes the examination of marine bioactive materials from microbe-engaged metabolites and the ecological implications of the sponge-microbe association in a changing ocean.

• Korean Journal of Microbiology
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• v.46 no.2
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• pp.177-182
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• 2010

The bacterial community structure of two marine sponges, Spirastrella abata and Cinachyrella sp. collected from Jeju Island, in April 2009, was analyzed by 16S rDNA-denaturing gradient gel electrophoresis (DGGE). DGGE banding patterns indicated 8 and 7 bands for Spirastrella abata and Cinachyrella sp., respectively. Comparative sequence analysis of variable DGGE bands revealed from 92% to 100% similarity to the known published sequences. The bacterial groups associated with Spirastrella abata were Alphaproteobacteria and Deltaproteobacteria. The bacterial community of Cinachyrella sp. consisted of Alphaproteobacteria, Gammaproteobacteria, and Actinobacteria. Alphaproteobacteria was common and predominant in both the sponge species. Deltaproteobacteria was found only in Spirastrella abata while Actinobacteria and Gammaproteobacteria were found only in Cinachyrella sp. The results revealed that though the common bacterial group was found in both the sponges, the bacterial community profiles differed between the two sponge species obtained from the same geographical location.

• Fisheries and Aquatic Sciences
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• v.8 no.1
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• pp.6-9
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• 2005

Two new cyclic peroxides were isolated from an undescribed sponge of the genus Plakortis sp. collected at Discovery Bay, Jamaica. The molecular structures were elucidated by interpreting ID and 2D NMR and HRMS data. The cyclic peroxides, Compound 1 and 2, exhibited significant antimicrobial activity against pathogenic bacteria and fungi with IC$_${50} values of 0.9-5.0$\mug/mL and 0.7-8.0$\mug/mL, respectively.