• Natural Product Sciences
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• v.21 no.1
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• pp.25-29
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• 2015

In a continuation of our studies to discover bioactive secondary metabolites from marine sources, we further investigated samples from a tryptamine and phenyl-alkane producing sponge, which resulted in the isolation of four uncommon small molecules and five nucleosides. Their structures were determined to be 7,8-dihydroimidazo[1,5-c]pyrimidin-5(6H)-one (1), 5-chlorocavernicolin (2), maleimide-5-oxime (3), 3-methylmaleimide-5-oxime (4), uridine (5), 2'-deoxyuridine (6), thymidine (7), adenine (8), and adenosine (9) by spectroscopic analyses. The isolated compounds were evaluated for inhibitory activity against soluble epoxide hydrolase (sEH) as well as the Wnt/${\beta}$-catenine signaling pathway.

• Journal of Advanced Marine Engineering and Technology
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• v.33 no.4
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• pp.497-501
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• 2009

When modal tests on the large structures and machinery are performed, it is in general difficult and inaccurate to use artificial excitation devices such as impact hammers, because of insufficient capacity of the device and different environmental conditions of the concerned structures. Therefore, the Operational Modal Analysis(OMA) technique, which is performed by measuring only vibration responses during the operation of the objective product, can be one alternative. In this paper, the way to identify natural frequencies, mode shapes and damping ratios of a ship by using the OMA during the sea trail is described.

• Natural Product Sciences
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• v.13 no.1
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• pp.90-96
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• 2007

Bioactivity guided fractionation of the cultured filtrates of Aspergillus versicolor, which was derived from a marine sponge Petrosia sp., yielded three polyketides: decumbenones A (1),B (2), and versiol (3). These compounds were identified on the basis of 1D and 2D NMR spectroscopic and MS analysis. The absolute configuration was defined by the modified Mosher's method. The isolated compounds were tested for cytotoxicity against a panel of five human solid tumor cell lines and antibacterial activity against twenty clinically isolated methicillin-resistant strains. This is the first report on the isolation of these compounds from a marine source.

• KSBB Journal
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• v.29 no.4
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• pp.271-277
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• 2014

In this study, crude extract of the seagrass Zostera japonica, and its solvent-partitioned fractions were evaluated for their antioxidant activity. The crude extract was successively fractionated into n-hexane, 85% aqueous methanol (85% aq.MeOH), n-butanol (n-BuOH), and water fractions by liquid-liquid partition. These include DPPH radical scavenging, hydroxyl radical scavenging in HT-1080 cells, peroxynitrite scavenging, and protective effect on DNA damage caused by hydroxyl radicals generated. In all assays, except for DPPH radical, 85% aq.MeOH and n-BuOH fraction showed the strong antioxidant activity. These results suggest that Z. japonica may be used as a potential source of natural antioxidants for the development of cosmetic product or functional food in the future.

• Natural Product Sciences
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• v.9 no.1
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• pp.18-21
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• 2003

Guided by the brine shrimp lethality assay, a new (4) and three known cyclitol derivatives (1-3) were isolated from the marine sponge Stelletta sp. Norsarcotride A (4) showed significant cytotoxicity against a small panel of five human tumor cell lines.

• Natural Product Sciences
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• v.22 no.3
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• pp.216-219
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• 2016

The microbial transformation of anthranilic acid (1) by the marine-mudflat-derived fungus Thielavia sp. produced an antibacterial polycyclic quinazoline alkaloid, thielaviazoline (2). The stereostructure of the metabolite was assigned based on detailed spectroscopic data analyses including comparison of the NMR ($^1H$ and $^{13}C$) data with those of reported compound (2). Compound 2 displayed in vitro antimicrobial activity against methicillin-resistant and multidrug-resistant Staphylococcus aureus (MRSA and MDRSA), with minimum inhibitory concentrations (MICs) of 6.25 and $12.5{\mu}g/mL$, respectively. Compound 2 also showed potent radical-scavenging activity against 2,2-diphenyl-1-picrylhydrazyl (DPPH) with an $IC_{50}$ of $11{\mu}M$, which was more active than the positive control, L-ascorbic acid ($IC_{50}$, $20.0{\mu}M$).

• The Journal of Fisheries Business Administration
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• v.44 no.1
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• pp.15-24
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• 2013

Recently the Korean court accepts two typies of fisheries damages caused by oil pollution.. One is the direct loss of fisheries production originated from pollution of oil spillover. The other is the indirect loss of fisheries production originated from governmental measure of restricting fishing activities because of safety of marine product of oil spillover areas. The paper tries to suggest the appropriated measure of oil pollution damages of hanging and floating netcage aquaculture fisheries using the court judgement for responsibility restriction on Herbei Spirit Case. The paper tries to compare the damge estimation method of floating netcage aquaculture fisheries with that of natural aquaculture fisheries using conventional theory of the population biology of living resources characterized with age distribution.

• Natural Product Sciences
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• v.13 no.4
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• pp.365-368
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• 2007

Bioactivity-guided fractionation of MeOH extract of an association of two sponges, Jaspis sp. and Poecillastra sp. resulted in isolation of four apocarotenoids (1 - 4). Their structures were determined on the basis of MS and NMR spectroscopic analyses and by direct comparison with those of reported. This is the first report on isolation of these compounds from any sponge. Isolated metabolites were evaluated for cytotoxicity against a small panel of solid human tumor cell lines.

• Natural Product Sciences
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• v.21 no.4
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• pp.261-267
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• 2015

Compared to their terrestrial and marine counterparts, little is known about the capacity of freshwater-derived actinomycete bacteria to produce novel secondary metabolites. In the current study, we highlight the disparities that exist between cultivation-independent and -dependent analyses of actinomycete communities from four locations in Lake Michigan sediment. Furthermore, through phylogenetic analysis of strains isolated from these locations, we identified a Streptomyces sp., strain B025, as being distinct from other Streptomyces spp. isolated from sediment. Upon fermentation this strain produced a rare class of eight-membered lactone secondary metabolites, which have been for their antitumor properties. We used spectroscopic and chemical derivitization techniques to characterize octalactin B (1) in addition to its corresponding novel, unnatural degradation product (2).

• Journal of the Korea Concrete Institute
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• v.25 no.1
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• pp.115-123
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• 2013

The steel industry, a representative industry that significantly consumes raw materials and energy, produces steel as well as a large amount of by-product steel slag through the production process. The vast habitat foundation of marine life has been destroyed due to recent reckless marine development and environment pollution, resulting in intensification of the decline of marine resources, and a solution to this issue is imperative. In order to propose a method to recycle large amounts of by-product slag into a material that can serve as an alternative to natural aggregate, the engineering properties and applicability for each mixing factor of environment friendly porous concrete as a material for the composition of marine ranches were evaluated in this study. The test results for percentage of voids per mixing ratio revealed that the margin of error for all conditions was within 2.5%. The compressive strength test results showed that the most outstanding environmental friendly porous concrete can be manufactured when mixing 30% slag aggregate and 10% specially treated granular fertilizer for the optimum volume fraction. As concrete for marine applications, the best seawater resistance was obtained with mixing conditions for high compression strength. An assessment of the ability to provide a marine life habitat foundation of environmentally friendly porous concrete showed that a greater percentage of voids facilitated implantation and inhabitation of marine life, and the mixing of specially treated granular fertilizer led to active initial implantation and activation of inhabitation. The evaluation of harmfulness to marine life depending on the mixture of slag aggregate and specially treated granular fertilizer revealed that the stability of fish is secured.