• Proceedings of the SCSK Conference
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• 2003.09b
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• pp.184-191
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• 2003

New pyranone derivative, 2-((3E)-4(2H, 3H, -benzo[3, 4-d] 1, 3-dioxolan-5-yl)-2-oxo-but-3-enyloxy)-5-hydroxy-4H-pyran-4-one (Seletinoid $G^{TM}$), was designed as a novel retinoid on the assumption that the pyranone ring may mimic the carboxylic acid moiety in retinoid structure. The enolic hydroxy of pyranone at five position was easily deprotonated to form an enolate. The role of enolate was similar to that of carboxylic acid. To evaluate the value of Seletinoid G as an anti-aging ingredient, various tests were performed for example inhibitory effect for MMP-l expression, anti-oxidative activity, procollagen synthesis in hairless mouse and primary skin irritation. The result of this study suggested that our new synthetic retinoid could be used as a safe material for anti-aging cosmetics.

• YAKHAK HOEJI
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• v.47 no.6
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• pp.450-455
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• 2003

Synthesis of (lR,5S,6S)-6-[(lR)-1-hydroxyethyl] -2-[(3S,5S)-5-(2-ethoxycarbonyl-1-moxy(hydroxy)iminoethyl)pyrrolidine-3-ylthio]-1-methylcarbapen-2-em-3-carboxylic acids (10a,l0b) were described. Methyl(2S,4S)-4-tritylthio-1-(allyloxycarbonyl)pyrrolidine-2-carboxyla late (I) was prepared from trans-4-hydroxy-L-proline with (2S,4R)-abs olute configuration as starting material. (2S,4S)-1-allyloxycarbonyl-2-(2-ethoxycarbonyl-hydroxy(methoxy )iminoethyl)-4-mercapto- pyrrolidines (6,7) were obtained from the tritylthio compound (I). (lR,5S,6S)-6-[(lR)-1-hydroxyethyl]-2-[(3S,5S)-5-(2-ethoxycarbonyl-1-methoxy(hydroxy)imino-ethyl)pyrrolidine-3-ylthio]-1-methylcarbapem-2-em-3-carboxylic acids (10a,10b) were obtained by the coupling reaction with carbapenem diphenylphosphates (8) and pyrrolidine-thiol moiety (6,7). Their in vitro antibacterial activities against both Gram-positive and Gram-negative were tested. Compounds ( 10a,10b) showed potent antibacterial activity except pseudomonas aerusinosa.

• Bulletin of the Korean Chemical Society
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• v.28 no.10
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• pp.1725-1728
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• 2007

Mast cells are key effector cells in the early phase allergic inflammation and in diverse immunological and pathological processes. In order to understand the effect on reduction of the anti-dinitrophenyl (DNP) IgE antibody-induced β-hexosaminidase release in RBL-2H3 rat mast cells, a novel series of 4-senecioyloxymethyl- 6,7-dimethoxycoumarins (SMDC) was prepared by reacting 4-chloromethyl-6,7-dimethoxycoumarin with various carboxylic acids. Compounds 8-11 with cyclic moiety such as phenyl, thiophenyl, pyridinyl, and furanyl group were found to inhibit-hexosaminidase release more potently (5.98-9.62 μM) than compounds 3- 7 and 12 with acyclic moiety (19.32-76.78 μM). Furthermore, compounds 8 and 9 inhibited IgE-induced ear swelling and significantly reduced systemic passive cutaneous anaphylaxis reaction in mice.

• Proceedings of the Membrane Society of Korea Conference
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• 1998.04a
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• pp.89-92
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• 1998

1. Introduction : Among many azeotropic compounds, pyridine which forms an azeotropic mixture with three moles of water boiling at 92-93$\circ$C is very useful synthetic intermediate in laboratory and industry. With conventional separation method, the dehydration of pyridine aqueous solution is difficult and requires strong drying chemicals. To overcome these difficulties, several researchers have investigated on the separation of pyridine from aqueous solution through polymer membranes. Kujawski reported several ion-exchang membranes containing carboxylic and sulfonic fuctional group for dehydration of aqueous pyridine solution [1]. We have applied the idea of activation of water tranport through ion-dipole interactions between polymer membrane and aclueous feed. Our previous studies reported on the in-situ complex membrane to separate water from aqueous pyridine solution based on simple acid'-base theory [2, 3]. Water transport was enhanced through in-situ complex formation between the , acid moiety in the membrane and the incoming pyridine moiety in the feed.

• Journal of Pharmaceutical Investigation
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• v.26 no.1
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• pp.55-59
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• 1996

The crystal structure of diflunisal, 2',4'-difluoro-4-hydroxy-3-biphenyl-carboxylic acid, was determined by single crystal X-ray diffraction technique. The compound was recrystallized from a mixture of acetone and water in monoclinic, space group C2/c, with $a\;=\;34.666(6),\;b\;=\;3.743(1),\;c\;=\;20.737(4)\;{\AA},\;{\beta}=\;110.57(2)^{\circ}$, and Z = 8. The calculated density is $1.324\;g/cm^3$. The structure was solved by the direct method and refined by full matrix least-squares procedure to the final R value of 0.045 for 1299 observed reflections. It was found that the molecules in the crystal are partially disordered, that is, the two equivalent conformers $(180^{\circ}$ rotated ones through C(1)-C(7)) are packed alternatively without regular symmetry or sequence. The two phenyl rings of the biphenyl group is tilted to each other by the dihedral angle of $43.3^{\circ}$. The carboxyl group at the salicylic moiety is just coplanar to the phenyl ring, and the planarity of this salicylic moiety is stabilized by an intramolecular hydrogen bond of O(3)-H(O3) O(2). The molecules are dimerized through the intermolecular hydrogen bonds at the carboxyl group in the crystal.

• YAKHAK HOEJI
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• v.42 no.1
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• pp.12-24
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• 1998

For the development of new cephalosporin antibiotics with aminothiazolcarboxymethylethoxyimino moiety on the C-7 position and tetrazolymethyl moiety on the C-3 position of cephe m ring, 7${\beta}$-[(Z)-2-(2-aminothiazol-4-yl)-2-(1-carboxy-1-methylethoxyimino)acetamido]-3-[5-(substituted)tetrazol-2-yl]methyl-3-cephem-4-carboxylic acids(28-35) were synthesized. These compounds were tested for antimicrobial activity in vitro against Gram(+) and Gram(-) bacteria. They showed remarkable antibacterial activity against Escherichia coli AB 1157, Escherichia coli AB 0111, Escherichia coli BE 1186, Micrococcus luteus ATCC 9341, Salmonella typhimurium TV 119, Salmonella typhimurium SL 1102, Staphylococcus aureus IFO 12732, Staphylococcus aureus R-209, but these compounds were not active against Pseudomonas aeruginosa N-10.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1994.04a
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• pp.171-171
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• 1994

Cephem ring의 C-7위치에 aminothiazoly lmethoxyimino기를 가진 화합물들이 항균활성을 증가시키고, G(-)균의 외막투과성을 촉진시킬뿐 아니라 광범위항균 spectrum을 갖게 하고 $\beta$-lactamase에 안정하며 PBP(penicillin binding protein)에 대한 결합친화성을 증가시킨다는 보고에 따라 본 저자는 C-7위치에 cefotaxime구조와 같이 aminothiazolylmethoxyimino acetamido moiety를 고정시키고 항균활성을 증가시키기 위하여 약리활성이 기대되는 5-(substituted)-2H-tetrazole유도체들을 합성하여 C-3 위치에 도입시킨 새로운 화합물 7$\beta$-〔(z)-2-(2-aminothiazol-4-yl)-2_(methoxyimino)acetamido〕-3-〔5-(substituted)tetrazol-2-yl〕 methyl-3-cephem-4-carboxylic acid 유도체를 합성하여 B. subtilis ATCC 6633, M. luteus ATCC 1004, E. coli KCTC 1039, E. coli ESS, K. pncumonia KCTC 1560, P. aeruginosa IF0 13130, S. typhimurium KCTC 1925, S. typhimurium SL 1102, 및 C. albicans ATCC 10231 등의 균과 fungus에 대하여 기존의 cefotaxime과 cefazoline을 대조물질로 사용하여 항균력을 비교하였다. 이들 화합물들은 대체적으로 M. luteus ATCC 6633, E. coli ESS, S. typhimurium SL 1102 균에 대해서는 cefotaxime보다 항균력이 우수하였으나 P. aeruginosa IF0 13130에 대해서는 항균력이 저하되었고 cefazolin보다는 대체적으로 항균력이 우수하였다.

• Journal of Environmental Science International
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• v.17 no.5
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• pp.509-516
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• 2008

New functional surfactant, N,N-dimethyl-N-dodecyl-N-(2-methyl benzimidazoyl) ammonium chloride(DDBAC) having benzimidazole(BI) functional group have been synthesized and the critical micellar concentration of DDBAC measured by surface tentiometry and electric conductivity method was $8.9{\times}10^{-4}M$. Micellar effects in DDBAC functional surfactant solution on the hydrolysis of p-nitrophenylacetate(p-NPA), p-nitro-phenylpropionate(p-NPP) and p-nitrophenylvalerate(p-NPV) were observed with change of various pH (Tris-buffer). The pseudo first rate constants of hydrolysis of p-NPA, p-NPP and p-NPV in optimum concentration of DDBAC solution increase to about 160, 280 and 600 times, respectively, as compared with those of aqueous solution at pH 8.00(Tris-buffer). It is considered that benzimidazole functional moiety accelerates the reaction rates of hydrolysis because they act as nucleophile or general base. In optimum concentration of DDBAC solution, the rate constants of hydrolysis of p-NPP and p-NPV increase to about 1.5 and 3.0 times, respectively, as compared with that of p-NPA. It means that the more the carbon numbers of alkyl group of substrates, the larger the binding constants between DDBAC micelle and substrates are. To know the hydrolysis mechanism of p-NPCE(p-NPA, p-NPP and p-NPV), the deuterium kinetic isotope effects were measured in $D_2O$ solutions. Consequently the pseudo first order rate constant ratios in $H_2O$ and $D_2O$ solution, $k_{H_2O}/k_{D_2O}$, were about $2.8{\sim}3.0$ range. It means that the mechanism of hydrolysis were proceeded by nucleophile and general base attack in approximately same value.

• YAKHAK HOEJI
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• v.50 no.5
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• pp.338-344
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• 2006

A novel series of 4-senecioyloxymethyl-6,7-dimethoxycoumarin, isolated from Crinum latifolium, was prepared by reacting 4-bromomethyl or 4-bromomethyl-6,7- dimethoxycoumarin with various carboxylic acids and examined for their anti-angiogenic activities in human umbilical vein endothelial cells (HUVECs). Among them, 4e, 4f, 4g and 4i with noncyclic moiety exhibited potent anti-angiogenic activity. However, compounds with cyclic moiety such as phenyl, pyridinyl, thiophenyl and furanyl group did not exhibit any anti-angiogenic activity. Also, compounds 4f and 4g which exhibited strong anti-angiogenic activity in a dose-dependent manner showed antitumor activity.

• Polymer(Korea)
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• v.38 no.5
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• pp.596-601
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• 2014

Polyamide (PA) oligomers, which are the hard segment of poly(ether-block-amide) (PEBA), presenting thermoplastic and high performance elastomeric properties were prepared by polycondensation between 4-aminobenzoic acid and 12-aminododecanoic acid. Subsequently PEBAs were obtained by addition polymerization of the PA oligomers and various molecular weights of poly(tetramethylene glycol) (PTMG). The structure of the final PEBA was identified by using FTIR and $^1H$ NMR and the thermal properties depending on changes in the structure of hard segment were collected by using DSC and UTM analysis. As the results, the melt temperature ($T_m$), the initial modulus, and the maximum strength of PEBAs increased with an increase in aromatic moiety up to 30% without reducing crystallinity.