• Bulletin of the Korean Chemical Society
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• 제28권2호
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• pp.225-228
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• 2007

Lipoic acid (LA) is a multifunctional antioxidant against a variety of ROS. Nitrone acts as free radical spin trap and exhibits neuroprotective activity. Thus, LA-nitrone derivatives (6, 7, 8, and 9) were synthesized and screened as an antioxidant and inhibitors for cholinesterases. Even though the antioxidant effect of LA-nitrone derivatives was not improved, they turned out to be effective inhibitors of acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) in μM range.

• 약학회지
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• 제52권6호
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• pp.514-519
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• 2008

We developed a convenient synthetic route to 3-alkylated 2-phenyl-4-quinolone derivatives (4a-h and 5a-c), which were expected to retain antitumor activity. A series of 2,3-dihydro-2-hydroxy-2-phenyl-4-quinolones (3a-h) was synthesized through dehydration, dealcoholation and hydration using acid-catalyzed one-pot reaction from anilines and ethyl benzoylacetates. 3-Methyl (or 3,3-dimethyl)-2-phenyl-4-quinolone derivatives 4 and 5 were synthesized from 3a-h through the methylation using methyl iodide. Formation of quinolone nucleus was undertaken with p-toluenesulfonic acid (p-TSA) at $90{\sim}110^{\circ}C$ in toluene for 3${\sim}$7.5 hr over the Dean-Stark apparatus. The key intermediates in these preparations are ${\beta}$-ketoesters 2a-h, which can be readily obtained from the corresponding anilines 1a-e by reaction with ethyl bezoylacetates.

• Macromolecular Research
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• 제12권3호
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• pp.258-262
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• 2004

We have developed facile and rapid polycondensation reactions of N-trimellitylimido-L-leucine diacid chloride 1 with eight different derivatives of hydantoin compounds 2a-h, in the presence of a small amount of a polar organic medium, such as Ο-cresol, by using a domestic microwave oven. The polycondensation reactions proceeded rapidly-they were complete within 7-9 min-to produce a series of novel optically active poly(amide-imide)s (3a-h) in high yield with inherent viscosities of 0.33-0.51 dL/g. We characterized the resulting poly(amide-imide)s by elemental analysis, thermal gravimetric analysis (DSC, TGA, and DTG), and FTIR spectroscopy, and by measuring their viscosities, specific rotations, and solubilities. All of the polymers were soluble at room temperature in polar solvents such as N ,N-dimethylacetamide, N,N-dimethylformamide, dimethylsulfoxide, tetrahydrofuran, and N-methyl-2-pyrrolidone.

• International Journal of Automotive Technology
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• 제7권3호
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• pp.283-288
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• 2006

A mathematical methodology is proposed for designing nozzle hole shapes producing controlled geometric cavitation. The proposed methodology uses an unstructured RANS flow solver, with the ability to compute sensitivity derivatives via an adjoint algorithm. The adjoint formulation for the N-S equations is presented while variation of the turbulence viscosity is not taken into account during the geometry modifications. The sensitivities are calculated in a mode independently of the shape parameterisation. The method is used to develop and evaluate conceptual shapes for nozzle hole cavitation reduction. The localized region at the hole inlet producing cavitation, is parameterised using its radius of curvature, while a cost function is formulated to eliminate the negative pressures present at this location. Sensitivity derivatives are used to assess the dependence of the localized region on the minimum pressure, and to drive the geometry to the targeted shape. The results show that the computer model can provide nozzle hole entry shapes that produce predefined flow characteristics, and thus can be used as an inverse design tool for nozzle hole cavitation control.

• 한국응용과학기술학회지
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• 제25권2호
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• pp.240-251
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• 2008

The central role of tyrosine phosphorylation in cell proliferative signaling mechanisms provides another target for chemotherapy. The aim of this research is to develop new quinazoline derivatives that possess the inhibitory activity for depidermal growth factor receptor (EGFR) tyrosine kinase (TK) as protein kinase inhibitors. In this work, a series of new 4-anilino-6-guanidino-7-methoxyquinazoline derivatives (12a-l) were synthesized by the introduction of guanidine moiety at C-6 of quinazoline nucleus and evaluated for their EGFR TK inhibitory activities.

• Archives of Pharmacal Research
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• 제16권2호
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• pp.164-167
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• 1993

Arylhydrazones of diethyl acetonedicarboxylate 3 was treated with fomaldehyde to 1-aryl-1, 4, 5, 6-tetrahyeheypyridazine derivatives 4a-f Cyclization of compound 4a-f by hydroxy-lamine afforded [3, 4-d] 1, 4, 5, 6-tetrahydropyridazine derivative 5a-f. Also, cyclization of compound 4c with semicarbazide gave pyrazolote [4, 3-c] pyridazine 6. On the other hand compound 3 reacted with ethylothofomate to give diethyl-1, 4-dihydro-1-arypyridazine-4-one-3, 5 dicaboxylate 7, which on treatment with hydrazine, semicarbazide and thiosemicarbazide gave pyridazine, amido and thioamido derivatives. The spectrl and antimicrobial data of these compounds 1-8 were studied.

• Archives of Pharmacal Research
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• 제25권6호
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• pp.851-855
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• 2002

Seven ergosterol derivatives (1-7) were isolated from silkworm larvae infected with Paecilomyces sp. J300. On the basis of spectroscopic means, their structures have been elucidated as 3$\beta$,5$\alpha$-dihydroxy-ergosta-7,22-diene (1), 5$\alpha$,6$\alpha$-epoxy-(22E,24R)-ergosta-8(14), 22-diene-3$\beta$,7$\alpha$-diol (2), 5$\alpha$,6$\alpha$-epoxy-(22E,24R)-ergosta-8, 22-diene-3$\beta$,7$\alpha$-diol (3), ergosta-4, 6, 8(14), 22-tetraene-3-one (4), ergosterol (5), ergosterol endoperoxide (6), 3$\beta$,5$\alpha$-dihydroxy-6$\beta$-methoxyergosta-7,22-diene (7). Compounds 3~7 showed moderate cytotoxicity against five tumor cells.

• 약학회지
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• 제42권4호
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• pp.364-369
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• 1998

New cephalosporin antibiotics. 7-[(1H-tetrazolyl)acetamidol]-3-[(4-carboxy-3-hydroxyisothiazol-5-yl)thiomethyl-3-cephem-4-carboxylic acid trisodium salt 2,7-[(5-ethylthio-3-hydroxyisothiazol-4-yl)carbox-amidol-3-[(4-carboxy-3-hydroxyisothiazo1-5-yl)thiomethyl)-3-cephem-4-carboxylic acid 3,7-[(2-aminothiazol-4-yl)acetamido]-3-[(4-carboxy-3-hydroxyisothiazol-5-yl]thiomethyl]-3-cephem-4-caboxylic acid 4,7-[(Z)-2-(2-aminothiazol-4-yl)-2-(alkoxyimino)acetamido)-3-[(4-carboxy-3-hydroxyisothiazol-5-yl)thiomethyl)-3-cephem-4-carboxylic acid 5-9 were synthesized. Antibacterial activities of these new cephalosporin derivatives and the relationship between their structures and activities were examined. Among them, 7-((Z)-2-(2-aminothiazol-4-yl)-2-(carboxymethoxyimino)acetamido)-3-[(4-carboxy-3-hydroxyisothiazol-5-yl)thiomethyl)-3-cephem-4-carboxylic acid 8 and 7-[(Z)-2-(2-aminothiazol-4-yl)-2-(l-carboxy-1-methylethoxyimino)acetamido]-3-[(4-carboxy-3-hydroxyisothiazol-5-yl)thiomethyl)-3-cephem-4-carboxylic acid 9 exhibited good antibacterial activities compared with those of cefotaxime and ceftriaxone.

• Bulletin of the Korean Chemical Society
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• 제32권4호
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• pp.1143-1145
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• 2011

The synthesis of novel iminecalix[4]arenes and further modification thereafter is described using a synthetic strategy. The reaction of the benzaldehyde derivatives with tetraamine functions on the calix[4]arene easily afforded the pure compounds in 92.4-95.7% yields, regardless of the effect of the substituents on the benzaldehyde derivatives. These compounds were stable under the conditions to obtain their analogue dialkylated in the narrow rim, with 83.2-89.9% yields. Characterization of the newly synthesized iminecalix[4]arene derivatives by spectroscopic methods revealed that all compounds are in the cone conformations.

• 한국군사과학기술학회지
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• 제2권1호
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• pp.73-81
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• 1999

Four bis-iodosobenzoic acid derivatives have been synthesizd in 5 steps following literature methods from 5-hydroxyantranilic acid; 1) diazotization and iodination, 2) acid protection, 3) tosylate substitution, 4) acid deprotection, 5) oxidation of iodo-substituent to iodoso group. Catalytic effects of new 5,5'-tri-, tetra-, deca-, polyethyleneglycoxy- bis(2-iodosobenzoic acid) on hydrolysis reactions of PNPDPP(p-nitrophenyl diphenyl phosphate), sarin and soman have been measured to determine the role of ethyleneglycoxy substituents as phase transfer catalysts. At $25{\pm}0.2^{\circ}C$, pH 8.0, and cetyltrimethyl ammonium chloride(CTACl) micelle solution condition, bis-IBA derivatives hydrolyzes PNPDPP with maximum pseudo-first order rate constant($K_{obsd}^{max}$) of 0.32035 ~ 0.13659 $sec^{-1}$, which corresponds to 2~18 times rate increase than those of unsubstituted o-IBA[iodosobenzoate($K_{obsd}^{max}=0.0645sec^{-1}$), iodoxybenzoate ($K_{obsd}^{max}$ = $0.0178 sec^{-1}$)]. At the similar condition for PNPDPP hydrolysis, bis-IBA derivatives also act as efficient catalysts for hydrolytic cleavage of nerve agents such as sarin and soman. Hydrolysis rate constant with 5,5'-polyethyleneglycoxy- bis(2-iodosobenzoic acid) shows 7 times increase than that of simple 5-hydroxy-2-iodosobenzoic acid.