• Ocean and Polar Research
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• v.38 no.4
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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.

• Ocean and Polar Research
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• v.39 no.2
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• pp.115-124
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• 2017

The objective of this study is to evaluate the antioxidant activity of the fruits of Ligustrum japonicum. The crude extract was successively fractionated into n-hexane, 85% aqueous methanol (85% aq.MeOH), n-butanol (n-BuOH), and water fractions by means of solvent polarity. The crude extract and its solvent fractions were evaluated for their antioxidant effect by four different assay systems: scavenging power on peroxynitrite and intralcellular ROS produced in HT-1080 cells; DNA oxidation inhibition; ferric reducing antioxidant power (FRAP). The n-BuOH fraction exhibiting potent antioxidant activity was further purified by C18 silica gel column chromatography and RP-HPLC to give tyrosol (1) and salidroside (2). The structure of isolated compounds was determined by extensive 2 D NMR experiments such as $^1H$ COSY, NOESY, HSQC and HMBC as well as by comparison with the published spectral data.

• Natural Product Sciences
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• v.14 no.1
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• pp.12-15
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• 2008

A chemical investigation of the polar extract of the sea cucumber Stichopus japonicus, collected from Jeju Island, Korea, has led to isolation of five new fatty acid derivatives (1, 4 - 7) along with known compounds (2 - 3, 8 - 14). Their structures were elucidated by a combination of MS and NMR spectroscopy.

• Journal of the Korean Society of Food Science and Nutrition
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• v.13 no.3
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• pp.326-333
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• 1984

The oxidation rate of krill lipids is very slow and no peroxides are accumulated even after long storage. By means of various chromatographic techniques and mass spectrophotometry, the primary antioxidant has been identified as ${\alpha}$-tocopherol. The phospholipid fractions did not show any antioxidative activity but peroxide-decomposing properties of total lipids depended upon the phospholipid contents. The peroxide-decomposing activities of phospholipids were due to the presence of polar materials generated during the storage. The most peroxide-decomposing fractions of oxidized krill lecithin by DEAE-cellulose column chromatography was low-molecule fraction (mean molecular weight: 182) and high-molecule fraction (mean molecular weight: 1942) was the next. The separation of peroxide-decomposing properties from low-molecule fraction was achieved by partitioning between chloroform and methanol/water. The methanol/water fraction showed strong peroxide-decomposing activities and main component of this fraction was assumed hydroxyamine compounds derived from choline.

• YAKHAK HOEJI
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• v.25 no.4
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• pp.193-197
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• 1981

Germanium (Ge) content in Zingiberis Rhizoma was determined by flameless atomic absorption spectrometry with a graphite tube atomizer. The Ge content of the cortical layer was 65.mu.g/g, the central cylinder, $98\mu$g/g and the total, $87\mu$g/g. In the effect of the extraction of Ge by various solvents, polar solvent was more effective than the nonpolar one, Especially, water was the most effective solvent. The water extract of Zingiberis Rhizoma, separated by sephadex G-25 gel filtration, was fractionated into 2 peaks at 254nm. Both the peaks showed atomic absorptions of Ge. It may be concluded that the Ge components of Zingiberis Rbizoma exist as the form of an aqueous organic compounds or associated forms with proteins.

• Archives of Pharmacal Research
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• v.22 no.6
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• pp.575-578
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• 1999

Derivatives of elema-1,3-diene were synthesized in several steps as polar analogs of $\beta$-elemene, antitumor agent under clinical phase. The lactone ring of compound 1 was opened by LiAlH4 to give diol 2 which was selectively protected by TBDPSCI. After acetylation of the secondary alcohol, the acetylated product was ozonolyzed and reduced to give elemene derivative 4 which was converted to diolefin 8 via selenides subsequent deprotection by tetrabutylammonium fluoride gave two compounds 9, 10.

• KSBB Journal
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• v.25 no.5
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• pp.409-420
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• 2010

Biopolymer-based materials recently have garnered considerable interest as they can decrease dependency on fossil fuel. Biopolymers are naturally obtainable macromolecules including polysaccharides, polyphenols, polyesters, polyamides, and proteins, that play an important role in biomedical applications such as tissue engineering, regenerative medicine, drug-delivery systems, and biosensors, because of their inherent biocompatibility and biodegradability. However, the insolubility of unmodified biopolymers in most organic solvents has limited the applications of biopolymer-based materials and composites. Ionic liquids (ILs) are good solvents for polar organic, nonpolar organic, inorganic and polymeric compounds. Biopolymers such as cellulose, chitin/chitiosan, silk, and DNA can be fabricated from ILs into films, membranes, fibers, spheres, and molded shapes. Various biopolymer/biopolymer and biopolymer/synthetic polymer composites also can be prepared by co-dissolution of polymers into IL mixtures. Heparin/biopolymer composites are especially of interest in preparing materials with enhanced blood compatibility.

• Journal of Photoscience
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• v.11 no.3
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• pp.107-113
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• 2004

Synthesis, absorption and fluorescence properties of 3-methyl indole (1), N-(benzenesulfonyl)-3-(3-oxo-but-1-enyl)-indole (2) and 1H-3-(3-oxo-but-1-enyl)-indole (3) are described. Extended conjugation at C-3 of indole as in 3 causes moderate resolution of $^1L_a$ and $^1L_b$ bands. However, 2 having an electron-withdrawing group at indolic nitrogen shows only the $^1L_a$ band. While the $^1L_b$ band largely remains solvent polarity independent, the $^1L_a$ band undergoes moderate red shift in polar solvents. The fluorescence in 2 and 3 originates from the $L_b$ transition. Additionally, interaction of 2 and 3 with BSA indicates that these compounds bind to the hydrophobic site of BSA with the formation of a highly fluorescent BSA-probe complex.

• Bulletin of the Korean Chemical Society
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• v.21 no.1
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• pp.81-86
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• 2000

In order to obtain detailed information on ground and excited states of curcumin and curcuminoids, as well as to understand the photobiological characteristics of them, their spectral and photophysical behaviors are investigated in various conditions. Various curcuminoids were obtained and their structures were determined by spectroscopic methods. In n-hexane, the absorption and fluorescence spectra of these compounds contain some structure, which disappear in more polar solvent such as methanol. The fluorescence intensities of curcumin and dimethylated curcumin decrease as the concentration of water increases. The intensities also decrease as the solvent varies from neutral to extremely acidic (lower than pH 1.5) or to basic (higher than pH 8.0) condition. These results indicate that the spectral and photophysical properties of both of curcumin and curcuminoids are strongly influenced by solvent, water, and pH.

• Journal of Radiation Industry
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• v.8 no.2
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• pp.105-109
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• 2014

This study was conducted to investigate the sensitivity of Arthrobacter sp. PAMC 25486 to various mutagens. ${\gamma}-ray$, UV-ray, Ethyl methane sulfonate (EMS) and hydrogen peroxide ($H_2O_2$) were used as mutagen, and the survival rate of Arthrobacter sp. was measured at various doses of ${\gamma}-ray$ and UV-ray, and concentrations of EMS and $H_2O_2$. Decimal reduction dose ($D_{10}$ value) of Arthrobacter sp. was determined 370 Gy for a gamma irradiation treatment, 0.019 J for a UV ray, 2.5 mM for EMS, and 230 mM for $H_2O_2$. This result will be applied for the development of superior mutant strain of Arctic bacteria producing valuable compounds.