• Bulletin of the Korean Chemical Society
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• v.26 no.10
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• pp.1569-1574
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• 2005

To develop new hole-blocking materials for phosphorescent organic light-emitting diodes (PhOLEDs), 5,6-dihydro-2,9-diisopropyl-4,7-diphenyl[1,10]phenanthroline (1) and 5,6-dihydro-2,9-diisopropyl-4-(4-methoxyphenyl)-7-phenyl[1,10]phenanthroline (2) were synthesized. While the absorption spectrum of 1 is very similar to that of 2, the photoluminescence spectrum of 1 has the feature of the narrower and blue-shifted blueviolet emission at the peak of 356 nm compared to that of 2. The HOMO and LUMO energy levels of 1 and 2 were estimated from the measurement of cyclic voltammetry, and 1 has the appropriate levels for a holeblocking layer (HBL). The use of 1 as a HBL in a green PhOLED led to good efficiency of 23.6 cd/A at 4.4 mA/$cm^2$.

• Korean Journal of Pharmacognosy
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• v.17 no.2
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• pp.168-177
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• 1986

Bioassay-directed isolation has yielded some cytotoxic substances against L1210 cell from the Korean traditional medicine. These include 5,2'-dihydroxy-6,7,8,6'-teramethoxyflavone $(IV,\;scutellaria\;root,\;ED_{50}\;=\;1.7\;{mu}g/ml)$, 7-geranyloxycoumarin $(XXXII,\;poncirus\;fruit,\;10.2\;{mu}g/ml) $and panaxydol $(I,\;white\;ginseng,\;0.03\;{mu}g/ml)$. IV, XXXII and their derivatives were synthesized in the purpose of in vivo tests and for observation of structure-activity relations. Among the flavone derivatives, 5,2',6'-trihydroxy-6,7,8-trimethoxy flavone (XVIII), 5-hydroxy-6,7,8-trimethoxy-6'-benzyloxyflavone (XVII) and 5,8-dihydroxy-6,7-dimethoxyflavone (X) showed the cytotoxicity which has no correlation to the flavone structures. Of the coumarins synthesized, 7,8-dihydroxycoumarin (XXVI), 6-7-dihydroxycoumarin (XXIX) and 6-hydroxy-5,7-dimethoxycoumarin (XXXI) showed considerable activities. Acetylated XXXI has moderate activity $(ED_{50}=17.2\;{mu}g/ml)$. Monobydroxycoumarins or their methyl and allyl ether were inactive. IV inhibits the growth of the solid form of S-180 by 70% at 40 mg/kg and shows T/C of 166% on the ascitic S-180 at 40 mg/kg. It strongly inhibits the activity of the membrane bounded ATPase from L1210 cell. The most cytotoxic fraction of the antitumor materials studied is the one from the trichosanthes root showing $ED_{50}=0. 0003\;{mu}g/ml$ against L1210 cell. This fraction, obtained from ethyl acetate extract, showed T/C of 130 and 135%, on ICR mice bearing S-180 and $BDF_1$ mice bearing L1210 at 10 mg/kg and 7.5 mg/kg, respectively.

• Journal of the Korean Chemical Society
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• v.23 no.5
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• pp.307-313
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• 1979

Seven new hydrazine derivatives were prepared from N-Aryllsufonylbenzimidoyl chloride. These were: ${\beta}-({\alpha}-Benzenesulfonamidobenzal)hydrazine\;(II),\;{\beta}-({\alpha}-Benzenesulfonamidobenzal)dimethylmethylenehydrazine\;(III),\;{\beta}-({\alpha}-Benzenesulfonamidobenzal)phenylhydrazine\;(VII),\;{\beta}-({\alpha}-Benzenesulfonamidobenzal)-4-nitrophenylhydrazine\;(VIII),\;{\beta}-({\alpha}-Benzenesulfonamidobenzal)-2,4-dinitrophenylhydrazine\;(IX),\;{\beta}-({\alpha}-Benzenesulfonamidobenzal)dimethylhydrazine\;(X),\;{\beta}-({\alpha}-Benzenesulfonamidobenzal)-p-methylphenylhydrazine\;(XI)$. The structure of these derivatives were identified by elemental analysis, spectral data and other chemical methods. In general, it was found that the yields of these reactions were significantly improved in polar solvent and by the electron attracting substituents in phenylhydrazine.

• Journal of the Korean Ceramic Society
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• v.49 no.5
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• pp.412-416
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• 2012

Porous SiC ceramics were prepared by using recycled SiC sludge, which is an industrial waste generated from solar cell industry. Polycarbosilane derivatives, such as polycarbosilane (PCS), polyphenylcarbosilane (PPCS) and hydridopolycarbosilane (HPCS) were used as binding agents for the fabrication of porous SiC ceramics at $1800^{\circ}C$ under Ar atmosphere. The effects of the various binding agents having different C/Si ratios were discussed on the sintering and porosity of the SiC ceramics. The prepared porous SiC ceramics were characterized by X-ray Diffraction (XRD) and Field-Emission Scanning Electron Microscope (FE-SEM). Thermal conductivity and porosity of SiC ceramics were measured at room temperature, and they were 56.7W/mK and 29.8%, respectively.

• Bulletin of the Korean Chemical Society
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• v.32 no.5
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• pp.1650-1656
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• 2011

A series of potent tricyclic derivatives with a non-aromatic amide as potent PARP-1 inhibitors were successfully synthesized and their PARP-1 inhibitory activity was evaluated. Among the derivatives, 2-(1-propylpiperidin-4-yloxy)-7,8,9,10-tetrahydrophenanthridin-6(5H)-one 23c displayed potent activity in a PARP-1 enzymatic assay and cell-based assay ($IC_{50}$ = 0.142 ${\mu}M$, $ED_{50}$ = 0.90 ${\mu}M$) with good water solubility. Further, molecular modeling studies confirmed the obtained biological results.

• Bulletin of the Korean Chemical Society
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• v.33 no.9
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• pp.2985-2990
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• 2012

New thiazoline derivatives 7a-c, and thiophenes 9a-c linked to indole moiety were easily prepared via the reaction of the acrylamide derivative 3 with phenacyl bromides 4a-c, depending on the reaction conditions. In addition, the reaction of compound 3 with hydrazonoyl chlorides 11a-f afforded a series of 1,3,4-thiadiazole derivatives 13a-f. Moreover, coupling of 3-(3-methyl-1H-indol-2-yl)-3-oxopropanenitrile (2) with the diazonium salts of 3-phenyl-5-aminopyrazole 16 or 3-amino-1,2,4-triazole 17 gave the corresponding hydrazones 18 and 19, respectively. Cyclization of the latter hydrazones yielded the corresponding pyrazolo[5,1-c]-1,2,4-triazine and 1,2,4-triazolo[5,1-c]-1,2,4-triazine derivatives 20 and 21, respectively. The structures of the synthesized compounds were assigned on the basis of elemental analysis, IR, $^1H$ NMR and mass spectral data. All the synthesized compounds were tested for in vitro activities against certain strains of fungi such as Aspergillus niger, Aspergillus nodulans, Alternaria alternate. Compounds showed marked inhibition of fungal growth nearly equal to the standards.

• YAKHAK HOEJI
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• v.50 no.5
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• pp.326-331
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• 2006

We designed and synthesized new benzylpiperidinyl ether derivatives as beta-amyloid aggregation inhibitors for the development of novel anti-Alzheimer's disease agents. As starting material, 4-hydroxypiperidine was used. For protection of the amine group in piperidine (2), di-tert-butyl dicarbonate was reacted with 4-hydroxypiperidine in the presence of triethylamine. For introduction of benzyl group, benzylbromide was treated with compound 2 in dioxane. After deprotection of Boc group on amine in compound 3, ester (5) was synthesized by addition of ethyl-4-chlorobutyrate. The alcohol 6 was synthesized by hydride reduction of 5 using $LiAlH_4$. To obtain final products (7-14), the alcohol 6 was condensed with each of substituted benzoic acids. To screen beta-amyloid aggregation inhibition of the products, thioflavinT assay was performed using $A{\beta}1-42\;at\;37^{\circ}C$ for 26 h incubation, in vitro. From the result of screening, compound 8, 9, 11 and 12 showed effective activity about $65{\sim}85\;{\mu}M\;as\;IC_{50}$ value. Among the prepared compounds, 4-[4-(benzyloxy)piperidino]butyl-4-chlorobenzoate (8) was the most effective inhibitor having $IC_{50}\;of\;65.4{\mu}M$.

• Biotechnology and Bioprocess Engineering:BBE
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• v.9 no.1
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• pp.65-68
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• 2004

The purpose of the present study was to examine the efficacy and mechanism of fraction IV cold ethanol fractionation and pasteurization (60$^{\circ}C$ heat treatment for 10 h), involved in the manufacture of albumin from human plasma, in the removal and/or inactivation of the hepatitis A virus (HAV). Samples from the relevant stages of the production process were spiked with HAV and the amount of virus in each fraction then quantified using a 50% tissue culture infectious dose (TCID$\_$50/). HAV was effectively partitioned from albumin during the fraction IV cold ethanol fractionation with a log reduction factor of 3.43. Pasteurization was also found to be a robust and effective step in inactivating HAV, where the titers were reduced from an initial titer of 7.60 log TCID$\_$50/ to undetectable levels within 5 h of treatment. The log reduction factor achieved during pasteurization was $\geq$4.76. Therefore, the current results indicate that the production process for albumin has sufficient HAV reducing capacity to achieve a high margin of virus safety.

• Applied Chemistry for Engineering
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• v.7 no.5
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• pp.1020-1026
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• 1996

Chitosan is the deacetylation product of chitin. Chitosan was converted to N-alkyl chitosan derivatives using proper aldehyde having different alkyl chains, then chitosan derivatives with quaternary ammonium salt were producted by quaternization with methyl iodide. Their antibacterial activities aganst S. aureus(ATCC 6538P) and E. coli (ATCC 14339), gram-positive bacteria and gram-negative bacteria, respectively, as introduced alkyl length were evaluated by shake flask method using colony count. The antibacteiral activity was found to be increased as alkyl chains. hydrophobic goups. These antibacterial agents were more active against S. aureus than E. coli. It may be due to the different of structure of cytoplasmic membrane.

• Biomolecules & Therapeutics
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• v.15 no.1
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• pp.46-51
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• 2007

Bioassay-directed chromatographic fractionation of an ethyl acetate extract from leaves of sweet potato (Ipomoea batatas L.) afforded six quinic acid derivatives: 3,5-epi-dicaffeoylquinic acid (1), 3,5-dicaffeoylquinic acid (2), methyl 3,5-O-dicaffeoylquinate (3), methyl 3,4-dicaffeoylquinate (4), methyl 4,5-dicaffeoylquinic acid (5),4,5-dicaffeoylquinate (6), and two phenolic compounds: caffeic acid (7) and caffeic acid methyl ester (8) together with three flavonoids: quercetin 3-O-${\beta}$-D-glucopyranoside (9), quercetin 3-O-${\beta}$-D-glucopyranoside, isoquercitrin (10) and kaempferol 3-O-${\beta}$-D-glucopyranoside (11). The structures of these compounds were elucidated by the aid of spectroscopic methods. These compounds were assessed for antioxidant activities using three different cell-free bioassay systems. All isolates except 11 showed potent DPPH and superoxide anion radicals scavenging, and lipid peroxidation inhibitory activities. 3,5-epi-DCQA (1) and methyl quinates (3-5) along with flavonoide 9 were isolated for the first time from this plant.