• Journal of Microbiology and Biotechnology
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• 제25권12호
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• pp.2007-2010
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• 2015

A new chemical inhibitor against severe acute respiratory syndrome (SARS) coronavirus helicase, 7-ethyl-8-mercapto-3-methyl-3,7-dihydro-1H-purine-2,6-dione, was identified. We investigated the inhibitory effect of the compound by conducting colorimetry-based ATP hydrolysis assay and fluorescence resonance energy transfer-based double-stranded DNA unwinding assay. The compound suppressed both ATP hydrolysis and double-stranded DNA unwinding activities of helicase with IC₅₀ values of 8.66 ± 0.26 μM and 41.6 ± 2.3 μM, respectively. Moreover, we observed that the compound did not show cytotoxicity up to 80 μM concentration. Our results suggest that the compound might serve as a SARS coronavirus inhibitor.

• Bulletin of the Korean Chemical Society
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• 제26권3호
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• pp.428-432
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• 2005

Squarylium or squaraine dyes are derived from 1,2-dihydroxycyclobuten-3,4-dione, otherwise known as squaric acids. They are two principal types: the 1,2-bisdonorsubstituted derivatives, and the 1,3-bisdonorsubstituted derivatives. The former are essentially merocyanines and have no distinctive properties, whereas the latter represent a unique type of chromophore, which is neither a merocyanines nor cyanine and has exceptional light absorption characteristics. They also have many functional applications based on their special properties. Thus it was the objective of this research project to synthesize a range of 1,3-squarylium dyes of widely differing structural types, and to investigate their light absorption and fluorescence properties in general, and the color change properties of appropriate examples in particular. Also in this study, the various pHinduced colour change processes were examined.

• Archives of Pharmacal Research
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• 제15권4호
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• pp.317-321
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• 1992

Furoyldroximoyl chloride 3d reacted with 2-aminopyridine, 2-aminopyrimidine. O-aminophenol, O-phenylenediamine and aminothiophenol to afford imidazo [1, 2-a]pyridine 6. imidazo[1, 2-a]pyrimidine 8, benzoxadiazine 10, nitrosobenzopyrizine 13a and nitrosobenzothiazine 13b, respectively. Isoxazoline 18 and pyrrolidino[3, 4-d]isoxazolin-4, 6-dione derivatives 19a and 19b obtained by the reaction of 3 with acrylonitrile and N-arylmaleimide. Hydroximoyl chloride 3 reacted with thiophenol and sodium benzene-sulfinate to yield furylglyoxaloxime 16a and 16b, respectively. Hydroximoyl chloride 3 reacted also with some active methylene compound to give isoxazole derivatives 20-23, respectively.

• 생약학회지
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• 제46권1호
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• pp.31-37
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• 2015

Thirteen compounds were isolated from n-hexane layer of the extracts of feces of Trogopterus xanthipes. Their chemical structures were elucidated as lupeol (1), lupenone (2), simiarenol (3), epitaraxerol (4), taraxerone (5), fatty acid esters of 11-oxo-${\beta}$-amyrin (6), 12-oleane-3,11-dione (7), $5{\beta}$-stigmastan-$3{\alpha}$-ol (8), $5{\beta}$-stigmastan-$3{\beta}$-ol (9), $5{\alpha}$-stigmastan-3-one (10), $5{\beta}$-stigmastan-3-one (11), $5{\beta}$-cholestan-$3{\alpha}$-ol (12), and 2-methoxyphenanthrene (13) on the basis of spectroscopic data. Even though all the isolated compounds are known, to the best of our knowledge, all the compounds (1-13) are reported from this species for the first time.

• 한국염색가공학회지
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• 제27권4호
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• pp.340-344
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• 2015

The interaction between curcumin(1,7-bis[4-hydroxy-3-methoxyphenyl]-1,6-heptadiene-3,5-dione) and ethylamines was studied in DMSO:$H_2O$(5:1, v/v) using absorption and fluorescence measurements. The association constant, $K_{ass}$, and the Stern-Volmer constants were calculated by the Benesi-Hildebrand and Stern-Volmer equation, respectively. Curcumin displayed marked UV-Vis absorption changes and highly responsive fluorescence quenching in the presence of ethylamine and the quenching ability was enhanced almost linearly with the concentration of ethylamines. The apparent Stern-Volmer constant measured for the ethylamine-curcumin system was about 1000-fold greater than that of the triethylamine-curcumin system, indicating considerably greater quenching efficiency of ethylamines.

• Bulletin of the Korean Chemical Society
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• 제25권3호
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• pp.415-416
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• 2004

• Bulletin of the Korean Chemical Society
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• 제27권12호
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• pp.2087-2090
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• 2006

• Bulletin of the Korean Chemical Society
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• 제25권12호
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• pp.1874-1876
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• 2004

Quantitative structure activity relationship has been probed for spirosuccinimide-fused tetrahydropyrrolo[1,2-a]pyrazine-1,3-dione derivatives acting as aldose reductase inhibitors. While the spirosuccinimide compounds contain a chiral center, the aldose reductase inhibition assay was performed with racemic mixtures in the published work. As the physicochemical descriptors of the QSAR analysis must be evaluated for a definite molecular structure, we devise a new 'racemic' descriptor as the arithmetic mean of the (R)-enantiomer descriptor and the (S)-enantiomer descriptor. The resultant QSAR model derived from the racemic descriptors outperforms the original QSAR models, closely reproducing the observed activity of optically pure enantiomers as well as racemic mixtures.

• Bulletin of the Korean Chemical Society
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• 제24권5호
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• pp.569-572
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• 2003

The majority of dyes belong to the chromophoric class known as donor-acceptor systems. The essential structural feature of such systems is the presence of one or more electron donating groups conjugated to one or more electron withdrawing groups via an unsaturated bridge. The pyrazolin-5-one system is an effective electron acceptor residue, and can also act as a weak electron donor. In our experiments, the various symmetrical and unsymmetrical H-chromophores were synthesized in the indoxyl, imidazo[1,2-a]pyridin-2-one, pyrazolin-5-one, and pyridin-2,6-dione residues, resulting in cross-conjugated donor-acceptor systems. And the visible light absorption was then associated with the migration of electron density from the donor region of the molecule to the acceptor region. Also, it was useful to prepare related non-cross-conjugated donor acceptor chromophores by combining these residues with other electron donor or acceptor moieties. For convenience such chromophores are referred to as merocyanines.

• Archives of Pharmacal Research
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• 제24권3호
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• pp.171-179
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• 2001

The present investigation deals with the synthesis of some new salicylamidoacetyl sulfonamides 3a,b, salicylamido ethylacetate 4, salicylamido acetic acid hydrazide 5, which is considered as the key intermediate for the synthesis of several series of new compounds such as salicylamido pyrazol 6 and pyrazolone 1. N-imido-derivatives 9, 10, 11, thiadiazole 13, oxadiazole 14, 15, Schiffs bases 16a-f. Cyclocondensation of Schiffs bases with thioglycolic acid gave thiazolidinone 18a-c while with acetylchloride afforded azitidinones 19a-c and with acetic anhydride gave 1,4-benzoxazepine-3,5-dione. Some of the compounds were tested for their analgesic and antiinflammatory activities as well as ulcerogenic effects. Some derivatives were more effective than salicylamide and ulcerogenic activity was variably lowered .