• YAKHAK HOEJI
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• v.38 no.6
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• pp.677-682
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• 1994

A number of 7-[3-hydroxy-(4-methylthio or 3-methylthiomethyl)pyrrolidinyl]quinoline-3-carboxylic acids were synthesized by condensation of 7-fluoro substituted quinoline-3-carboxylic acid with 3-hydroxy-4-methylthiopyrrolidine or 3-hydroxy-4-methylthiomethylpyrrolidine. The in vitro antimicrobial activity of them were tested against twenty species of Gram-positive or Gram-negative microorganisms. It showed remarkable antibacterial activity, particularly against Gram-positive microorganisms. Among those 1-cyclopropyl-5-amino-6,8-difluoro 7-(3-hydroxy-4-methylthiomethylpyrrolidinyl)-1,4-dihyd ro-4-oxo-3-quinolinecarboxylic acid(12d) and 1-cyclopropyl-6-fluoro-8-methoxy-7-(3-hydroxy-4-methylthiometby1pyrrolinyl)-1,4-dihydro-4-oxo-3-quinolinocarboxylic acid(12g) showed the most potent in vitro antibacterial activity, and 12d showed better antibacterial activity against MRSA compared to ciprofloxacin and sparfloxacin.

• YAKHAK HOEJI
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• v.48 no.3
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• pp.202-206
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• 2004

New asymmetric dimers, N,N'-dialkyl-4'-hydroxy-4-oxo-2,2',3,3'-tetrahydro-2,2'-diphenyl-4,4'-quinolones 3a-f were synthesized through the dehydration and dea1coholation of N-alkylanilines and ethyl benzoylacetate. Dimers 3a-f were identified by NMR, IR and GC-MS. A series of dimer 3a-f has been synthesized using acid-catalyzed one-pot reaction that involved the condensation, cyc1ization and dimerization. Similarly, the 6,6'-methoxy (or 7,7'-methoxy) substituted dimers were prepared from N-alkyl-meta-(or para)-anisidines. Formation of dimers was undertaken with p-toluenesulfonic acid (p-TSA) at 90∼11$0^{\circ}C$ in toluene for 2∼6 hours over the Dean-Stark apparatus.

• Journal of Plant Biology
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• v.31 no.2
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• pp.113-119
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• 1988

The effects of the defoliant and desiccant dimethipin(2,3-dihydro-5,6-dimethyl-1,4-dithiin-1,1,4,4-tetraoxide) on the passive permeability and osmotic ground value of onion(Allium cepa L.) epidermal cells were investigated by plasmometric method. The osmotic ground value and the water permeability of onion epidermal cells were decreased by 9.8% and 41.2%, respectively, and the passive permeabilities of nonelectrolytesurea, methylurea, ethylurea and malonamide-were also decreased by the range of 15.7%∼57.8% after treatment with 10-3M dimethipin. After treatment with 10-4M dimethipin, the osimotic ground value and the solute permeability of onion epidermal cells were also decreased by 3.7% and 24.5%∼48.8%, respectively, but the water permeability of onion epidermal cells was increased by 8.3%. It was suggested that dimethipin treatment modified the cell membrane of onion epidermis.

• YAKHAK HOEJI
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• v.43 no.4
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• pp.437-441
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• 1999

Enoxacin[1-ethyl-6-fluoro-1,4-dihydro-4-oxo-7-(1-\piperazinyl)-1,8-naphthyridine-3-carboxylic acid, ENX] is a new quinolone antibacterial agent. The method is based on the highly colored charge-transfer complex formation of this drug as a $\pi$-electron donor with 7,7,8,8-tetracyanoquinodimethane(TCNQ) or chloranil(CL) as $\pi$-acceptors. The colored products were measured spectrophotometrically at 842 nm and 552 nm for TCNQ and CL, respectively. The different experimental conditions are optimized. The linearities for TCNQ and CL were $1.6{\;}\mu\textrm{g}/mL~32{\;}\mu\textrm{g}/mL$ and $6.4{\;}\mu\textrm{g}/mL~160{\;}\mu\textrm{g}/mL$, respectively and colors were produced in non-aqueous media. This report describes a simple and ra\pid method for the analysis of enoxacin.

• Journal of the Korean Chemical Society
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• v.56 no.1
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• pp.68-73
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• 2012

In the present study, we have synthesized novel Isopropyl 2-(4-substitutedbenzylidene)-5-methyl-3-oxo-7-phenyl-3,7-dihydro-2H-thiazolo[3,2-a]-pyrimidine-6-carboxylate derivatives (6a-j). Elemental analysis, IR, $^1H$ NMR and mass spectral data elucidated structure of newly synthesized compounds. The newly synthesized compounds were screened for antiinflammatory and anti microbial studies. Their biological activity data of the 10 compounds indicates that two compounds posses potent anti-inflammatory and five have antimicrobial activities.

• Journal of Microbiology and Biotechnology
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• v.25 no.12
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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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• v.19 no.10
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• pp.1059-1063
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• 1998

Regiospecific total syntheses of (±)-11-deoxy-4-methoxy-10-oxo-βrhodomycinone (21a) and (±)-11-deoxy-1-methoxy-10-oxo-β-rbodomycinone (21b) are described. 2-(2-Bromoethyl)-1,3-dioxane (6) was transformed to naphthalenone 12, which was condensed with (phenylsulfonyl)-isobenzofuranone 13 to afford 7,8-dihydro-9-ethyl-6-hydroxy-4-methoxynaphthacen-5,12-dione (15). Epoxide 16 prepared from olefinic compound 15, reacted with HF/Pyr (7:3) to give 17. Dihydroxylation of 17 with t-BuOK/P(OMe)3/O2, selective cis-diol protection of mixed compounds 18 with phenylboronic acid in toluene, separation of cis-boronate 19 and trans-diol 20 by column chromatography on silica gel, and cleavage of the boronate group of 19 with 2-methylpentane-2,4-diol in acetic acid completed the construction of 21.

• Journal of Life Science
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• v.24 no.8
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• pp.873-879
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• 2014

The constituents from the needles of the pine tree, Pinus densiflora, were purified and investigated for antithrombotic activity. The needles were initially extracted three times with 70% ethanol, and the extract was sequentially fractionated with chloroform and n-butanol. The aqueous layer formed after n-butanol fractionation was subjected to purification by medium pressure and high pressure liquid chromatography. The two neolignans, 2, 3-dihydro-7-hydroxyl-3-hydroxymethyl-2-(4'-hydroxyl -3-methoxyphenyl)-5-benzofuranpropanol-3-O-${\alpha}$-rhamnopyranoside (a neolignan glycoside) and 2, 3-dihyro-3-hydroxymethyl-7-methoxy-2-(4'-hydroxyphenyl-3'-methoxy)-5-benxofuran propanol 4'-O-${\alpha}$-rhamnopyranoside (icariside $E_4$) were identified by $^1H$ and $^{13}C$ NMR spectra. The effect of the purified compounds, the neolignan glycoside and icariside $E_4$ on thrombin inhibition were investigated by measuring thrombin clotting time in plasma. As a result, the clotting of the neolignan glycoside was delayed four times compared to that of icariside $E_4$. In addition, an analysis of the inhibition effect by changing the concentration showed that the clotting time was delayed in accordance with an increase in the concentration of the neolignan glycoside. Furthermore, we examined the interaction of thrombin and fibrinogen to clarify the action mechanism. As a result, the delay of clotting time in the response of thrombin and pure fibrinogen may indicate that neolignan glycosides inhibit the thrombin action in a direct manner, leading to the suppression of fibrin generation.

• Journal of the Korean Society of Clothing and Textiles
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• v.33 no.12
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• pp.2002-2010
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• 2009

The degradation behavior of berberine is examined using GC-MS to select the fingerprint products that can be used to identify berberine dye in badly faded archaeological textiles. A total of $100^{\circ}C$ thermal and $H_2O_2/UV/O_2$ degradation systems were used to degrade berberine chloride 0.1% solution up to 408 hours. The samples were analyzed using the GC-MS. Dihydroberberine, 2-pteridinamine, 6,7-dimethyl-N-[(trimethylsilyl) oxy]-, and 8-methoxy-11-[3-methylbutyl]-11H-indolo[3,2-c]-quinoline, 5-oxide were detected as the major products of thermal degradation and identified as the fingerprint products for berberine dye at the early stage of degradation. Isobenzofuran-1,3-dione,4,5-dimethoxy-, 9H-fluorene,3,6-bis(2-hydroxyethyl)-,1,3-dioxolo[4,5-g]isoquinolin-5(6H)-one,7,8-dihydro-, and 3-tert-butyl-4-hydroxyanisole were detected as the major products generated by the $H_2O_2/UV/O_2$ degradation and identified as the fingerprint products for berberine dye under severe degradation conditions.

• Korean journal of food and cookery science
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• v.17 no.6
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• pp.565-570
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• 2001

Soibirhym(Portulace oleracea) was extracted by methanol and its antimicrobial activities against food spoilage or foodborne disease microorganisms were investigated by the paper disc method. The microorganisms used in this experiment included 5 species of bacteria(Escherichia coli, Pseudomonas aeruginosa, Salmonella typhimurium, Klebsiella Pneumoniae, Staphylococcus aureus) and 3 species of fungi(Fusarium solani, Aspergillus flavius, Penicillium citreonigrum). Soibirhym showed high antimicrobial activites against P. citreonigrum, P. aeruginosa and K. pneumoniae. Minimum inhibitory concentrations(MICs) on S. aureus, P. citreonigrum and K. pneumoniae were 200, 200 and 250 mg/㎖, respectively. In the methanol extracts from Soibirhym, 147 kinds of compound were separated by GC/MS. The extraction yields of phenolics, furans, alcohols, acids and esters, ketones, aldehydes, and miscellaneous compounds were 7.43%, 6.13%, 2.20%, 41.06%, 9.21%, 0.15% and 1.08%, respectively. Some antimicrobial compounds such as 2,3-dihydro-benzofuran, 4-hydroxy-3-methoxy-benzoic acid, 4-hydroxy benzeneethanol were detected in the methanol extract.