• Fibers and Polymers
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• v.5 no.2
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• pp.83-88
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• 2004

In order to assess the potential of the hydroxy-containing polyamic acid (PHAA) synthesized from 3,3'-dihydroxy benzidine and pyromellitic dianhydride for a fire-safe polymer, the cyclization pathway of PHAA has been investigated using a model compound prepared from 2-aminophenol and phthalic anhydride. The reaction was monitored. by $^1{H-nuclear}$ magnetic resonance. N-(2-hydroxyphenyl) phthalamic acid is converted to N-(2-hydroxyphenyl) phthalimide at ca. 175$^{\circ}C$, showing endothermic reaction. The imide structure is rearranged to the benzoxazole structure over ca. $400^{\circ}C$. These results are similar with that of PHAA. According to pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) data, water and carbon dioxide are released during the cyclization and rearrangement reaction. One DMAc molecule is complexed with one carboxyl acid group in PHAA, which accelerates the imidization process to release more easily the flame retardant, water.

• Bulletin of the Korean Chemical Society
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• v.35 no.12
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• pp.3502-3508
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• 2014

The first synthetic route to 5'-norcarbocyclic C-nucleoside [7-oxa-7,9-dideazadenosine (furo[3,2-d]pyrimidine) and 9-deazaadenosine (pyrrolo[3,2-d]pyrimidine)] phosphonic acids from commercially available 1,3-dihydroxy cyclopentane was described. The key C-C bond formation from sugar to base precursor was performed using Knoevenagel-type condensation from a ketone derivative. Synthesized C-nucleoside phosphonic acids were tested for anti-HIV activity as well as anti-leukemic activity. Compound 26 showed significant anti-leukemic activity.

• BMB Reports
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• v.46 no.2
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• pp.119-123
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• 2013

Methyl-6,7-dihydroxy-1,2,3,4-tetrahydroisoquinoline (salsolinol), an endogenous neurotoxin, is known to perform a role in the pathogenesis of Parkinson's disease (PD). In this study, we evaluated oxidative modification of cytochrome c occurring after incubation with salsolinol. When cytochrome c was incubated with salsolinol, protein aggregation increased in a dose-dependent manner. The formation of carbonyl compounds and the release of iron were obtained in salsolinol-treated cytochrome c. Salsolinol also led to the release of iron from cytochrome c. Reactive oxygen species (ROS) scavengers and iron specific chelator inhibited the salsolinol-mediated cytochrome c modification and carbonyl compound formation. It is suggested that oxidative damage of cytochrome c by salsolinol might induce the increase of iron content in cells, subsequently leading to the deleterious condition which was observed. This mechanism may, in part, provide an explanation for the deterioration of organs under neurodegenerative disorders such as PD.

• 한국정보디스플레이학회:학술대회논문집
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• 2002.08a
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• pp.933-935
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• 2002

In this paper, new non-chiral molecules with semi-fluorinated alkyl chains were synthesized varying the structure of central bent core unit. Their mesomorphic properties were investigated by DSC and polarized microscopy. The compound with 1,3-dihydroxy phenylene unit could form an enantiomeric smectic phase, but the remaining compounds with bent-core mesogenic unit were not liquid crystalline. In this presentation, their x-ray measurement and electro-optical property will be also described.

• Natural Product Sciences
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• v.23 no.4
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• pp.306-309
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• 2017

Microbial transformation of $({\pm})$-6-(1,1-dimethylallyl)naringenin (6-DMAN, 1) and $({\pm})$-5-(O-prenyl) naringenin-4',7-diacetate (5-O-PN, 2) was performed by using fungi. Scale-up fermentation studies with Mucor hiemalis, Cunninghamella elegans var. elegans, and Penicillium chrysogenum led to the isolation of five microbial metabolites. Chemical structures of the metabolites were determined by spectral analyses as $({\pm})$-8-prenylnaringenin (3), (2S)-5,4'-dihydroxy-7,8-[(R)-2-(1-hydroxy-1-methylethyl)-2,3-dihydrofurano]flavanone (4), $({\pm})$-5-(O-prenyl)naringenin-4'-acetate (5), $({\pm})$-naringenin-4'-acetate (6), and $({\pm})$-naringenin (7), of which 5 was identified as a new compound.

• Journal of the Korean Society of Tobacco Science
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• v.23 no.2
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• pp.162-167
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• 2001

This study was carried out to quantitatively determine phenol compounds in smoke total particulate matter(TPM) to evaluate the qualititive characteristics of flue-cured tobacco varieties(NC82, KFl14 and KFl18). After collecting The TPM by using smoking machine, the concentration of phenol compounds were analyzed by gas chromatography as their trimethylsilyl derivative on a fused capillary column bonded with a 5％ PE ME siloxane stationary phase. In all the flue-cured tobacco varieties, the major phenol components were monohydroxy compounds. The order of the highest concentration of total phenol compounds in TPM was NC82, KF114 and KFl18 but the contents of dihydroxy compound in the KFl18 was higher than those of NC82 and KF114.

• Archives of Pharmacal Research
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• v.28 no.3
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• pp.280-284
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• 2005

The chromatographic separation of the MeOH extract from the aerial parts of Syneilesis palmata led to the isolation of a new sesquiterpene glycoside 4, together with four known compounds. Their structures were characterized to be 4$\beta$,5$\beta$-epoxy-caryophill-8,(15)-ene (1), 3$\beta$­hydroxy-gultin-5-ene (2), 4$\alpha$,5$\beta$-dihydroxy-caryophill-8,(15)-ene (3), (-)-oplopan-4-one-10-$\alpha$-O­$\beta$-D-glucose (4) and 3-hexenyl-1-O-$\beta$-D-glucopyranose (5), based on spectroscopic and chemical methods. Compound 2 showed moderate cytotoxicity against five human tumor cell lines in vitro with its EDso values ranging from 5.90-1 0.83 $\mu$g/mL.

• Archives of Pharmacal Research
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• v.26 no.10
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• pp.816-820
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• 2003

The chloroform extract of the aerial part of Limnophila geoffrayi showed antimycobacterial and antioxidant activities. Bioassay-guided fractionation has led to the isolation of the flavones nevadensin (5,7-dihydroxy-6,8,4'-trimethoxyflavone, 1) and isothymusin (6,7-dimethoxy-5,8,4'-trihydroxyflavone, 2). Both compounds 1 and 2 exhibited inhibition activity against Mycobacterium tuberculosis, with equal MIC value of $200{\;}\mu\textrm{g}/mL$. Only compound 2 exhibited antioxidant activity against the radical scavenging ability of DPPH, with the $IC_{50}$ value of $7.7{\;}\mu\textrm{g}/mL$. The crude hexane, chloroform and methanol extracts as well as the pure compounds 1 and 2 did not exhibit mutagenic activity in the Bacillus subtilis recassay.

• Archives of Pharmacal Research
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• v.29 no.6
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• pp.497-502
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• 2006

A new natural C-benzylated chalcone, $2',4'-dihydroxy-3'-(2-hydroxybenzyl)-6{\c}-methoxychalcone$ (2), along with two other flavonoids, tiliroside and kaempferol 3-O-rutinoside, and an oxoaporphine alkaloid, lanuginosine were isolated from the aerial parts of Ellipeiopsis cherrevensis (Annonaceae). Two known polyoxygenated cyclohexene derivatives, ferrudiol and zeylenol, and a new analog, ellipeiopsol D, were also isolated. The chalcone 2 exhibited cytotoxic activity against human small-cell lung-cancer (NCl-H187), epidermoid carcinoma (KB) and breast cancer (BC) cell lines with $IC_{50}$ values of 1.40, 5.31 and $13.92\;{\mu}g/mL$, respectively. This compound also showed antimalarial activity against Plasmodium falciparum with an $IC_{50}$ value of $7.1\;{\mu}g/mL$ as well as antimicrobacterial activity against Mycobacterium tuberculosis with a MIC of 25 mg/mL.

• Natural Product Sciences
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• v.24 no.4
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• pp.284-287
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• 2018

A new isoprenylated acetophenone, acronyculatin P (1) as well as two known compounds, 3',5'-diisoprenyl-2',4'-dihydroxy-6'-methoxyphenylethanone (2) and 3'-isoprenyl-2',4',6'-trihydroxyphenylethanone (3) were isolated from the stem bark of Acronychia pedunculata (L.) Miq. The structures were determined by HRESIMS, 1D and 2D NMR. The inhibitory activity of the isoprenylated acetophenone derivatives against murine leukemia P-388 cells showed compound 1 moderate activity with $IC_{50}$ $15.42{\mu}M$.