• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2015.05a
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• pp.107-107
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• 2015

In order to investigate electrochemical behavior and biocompatibility of Co-Cr dental alloy by electrochemical corrosion test and MTT assay, the xCo-25Cr-yW-zNi alloys were used in this study. Samples of Co-Cr-W-Ni alloys were manufactured using arc melting furnace. The microstructure of the alloys was examined by optical microscopy (OM), Field emission scanning electron microscopy (FE-SEM), energy dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), MTT assay, and corrosion test. Corrosion resistance increased slightly as cobalt (Co) content increased. And bioactivity was concerned with nickel (Ni) and tungsten (W). Biocompatibility of Co-Cr alloy depended on Ni and W contents.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.1375-1376
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• 2007

A synthesized 21-mer single-stranded DNA(ss DNA) was covalently immobilized onto a self-assembled aminoethanethiol monolayer modified gold electrode onto QCM. The covalently immobilized ssDNA was hybridized with complementary ssDNA. The interaction between surface immobilized ssDNA and complementary 21-mer DNA in solution was also examined. Each step was followed by monitoring changes in the QCM frequency with time. Also, PBS with pH 7.0 was selected as a supporting electrolyte in order to get maximum sensitivity and good bioactivity.

• Natural Product Sciences
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• v.22 no.2
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• pp.129-133
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• 2016

Bioactivity-guided fractionation of a methanolic extract of Buddleja officinalis led to the isolation of two monoterpenes, crocusatin M (1), crocusatin C (2), a flavonoid, acacetin (3), three lignans, lariciresinol (4), pinoresinol (5), and syringaresinol (6), and two triterpenoidal saponins, mimengoside B (7) and songarosaponin A (8). The structures of isolates were identified based on 1D-, 2D-NMR, and MS data analysis. All isolates were tested for their inhibition on LPS-induced NO production in RAW 264.7 cells. As a result, mimengoside B (7) and songarosaponin A (8) showed a mild inhibitory activity of NO production.

• Natural Product Sciences
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• v.13 no.4
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• pp.355-358
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• 2007

Further bioactivity-directed fractionation of the ethanol extract of the seeds of Annona cherimolia has led to the isolation of two mono-tetrahydrofuran acetogenins, xylomaticin (1) and gonionenin (2). The structures of these compounds were characterized on the basis of chemical and spectroscopic data. Compounds 1 and 2 have a relative stereochemistry relationship of threo/trans/threo across the mono-tetrahydrofuran ring with its two flanking hydroxyls. Compounds 1 and 2 are known, but are first isolated from this plant. In brine shrimp lethality test (BST), 1 and 2 exhibited cytotoxic activity.

• 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.

• Korean Journal of Pharmacognosy
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• v.48 no.2
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• pp.113-118
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• 2017

Bioassay guided fractionation and isolation of the $CH_2Cl_2$ extract from the apical bud of Gardenia sootepensis (Rubiaceae) led to the isolation of five known flavonoids (1-5). The structures of the compounds were determined by 1D and 2D NMR, and MS experiments, as well as by comparison of their data with published values. Compounds 1-5 were isolated for the first time from this plant source. The isolated compounds were evaluated for their cancer chemopreventive potential based on their ability to inhibit nitric oxide (NO) production. Among the isolates, compound 4 exhibited considerable NO inhibitory activity with an $IC_{50}$ value of $13.8{\mu}M$.

• Journal of Microbiology
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• v.37 no.4
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• pp.213-217
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• 1999

An extracellular endopeptidase from Bacillus cereus SH-7 was purified to homogeneity. The protease was most active at pH 8 and $40{\circ}C$, respectively. The molecular mass of the protease was 40 kDa on SDS-PAGE, and 120 kDa by gel filtration, suggesting that the native enzyme is composed of three homogeneous subunits. The $K_m\;and\;V_{max}$ values of the protease for N-succinyl-$(Ala)_2$-Pro-Phe-p-nitroanilide were 11.11 mM and 170 nmol/mg of protein/min, respectively. The protease was also identified as a metalloprotease. The bioactivity of the SH-7 protease will need further study in the future.

• Archives of Pharmacal Research
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• v.24 no.6
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• pp.518-521
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• 2001

Six bioactive alkaloids, aristolactam B(1), poperolactam A(2), aristolactam A(3), norcepharadione B(4), cepharadione B(5) and splendidine(6) were isolated by bioactivity-guided fractionalton of a methanolic extract of the aerial part of Houttuynia cordata. Several of them exhibited significant cytotoxicity against five human tumor cell lines (A-549,SK-OV-3,SK-MEL-2, XF-498 and HCT-15) in vitro.

• Archives of Pharmacal Research
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• v.23 no.3
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• pp.243-245
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• 2000

The diethyl ether extract of isodon excisus var. coreanus exhibited significant inhibitory activity in aromatase assay. Bioactivity-guided fractionation of the extract led to the isolation of three active compounds: inflexin(ent-1${\alpha}$-hydroxy-3${\beta}$,6a-diacetoxykau r-16-en-11,15-dione) (1), ursolic acid (2), and ursolic acid 3-O-acetate (3).

• Korean Journal of Pharmacognosy
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• v.52 no.4
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• pp.203-207
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• 2021

LC/MS approach targeting secondary metabolites of bacterial strain resulted in the discovery of boholamide A (1), from the culture of marine actinomycete strain which was isolated from a tidal mudflat in Muan, Republic of Korea. Boholamide A (1), a cyclodepsipeptide with HDMN, APD, glycine, and valine was structurally determined by using 1D/2D NMR spectroscopy, mass spectrometry and UV spectroscopy. Boholamide A (1) showed the inhibitory activity against Bacillus subtilis, with IC₅₀ value of 0.08 mM.