• Journal of the Korean Chemical Society
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• v.54 no.1
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• pp.77-87
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• 2010

Hospital-acquired methicillin-resistant Staphylococcus aureus (MRSA) has been an increasing problem worldwide since the initial reports over 40 years ago. To examine new drug leads with potential antibacterial activities, Various N'-[(-3-substituted-4-oxo-1,3-thiazolidin-2-ylidene]-4-hydroxy benzohydrazide (4a-4.i) and N'-[-(3,4-disubstituted)-1,3-thiazolidin-2ylidene)]-4-hydroxybenzohydrazide from (5.a-5.i) to (10.a-10.i) were synthesized using appropriate synthetic route. The entire test compounds (4.a-4.i) and from (5.a-5.i) to (10.a-10.i) were assayed in vitro against s. aureus strain. The minimum inhibitory concentration (MIC) was determined for test compounds and for reference standards. The test compounds showed significant antibacterial activity against the strains used, when tested in vitro. In general, p-hydroxybenzohydrazide ring and substituted thiazoline ring are essential for antimicrobial activity. Among the compounds tested, compounds 6.f, 7.g, 9.f and 10.f, 10 i were found to be most potent. The test compounds were found nontoxic upto the dose level of 2000 ${\mu}g$/mL. The intact compounds were then subjected for 3D-QSAR studies. 3D-QSAR study based on the principal of alignment of pharmacophoric features by Schrodinger PHASE module. The 3D-QSAR study allowed us to confirm the preferential binding mode of p-hydroxybenzohydrazide inside the active site.

• Archives of Pharmacal Research
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• v.29 no.1
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• pp.16-25
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• 2006

A novel series of 1-(1-benzofuran-2-yl-ethylidene)-4-substituted thiosemicarbazides (2a-d) along with some derived ring systems: substituted-2,3-dihydro-thiazoles(3a-c, 4a-f) and thiazolidin-4-ones(5a-d and 6a-d), were synthesized. In addition, cyanoacetic acid-(1-benzofuran-2-yl-ethylidene) hydrazide(7) was used to prepare another new series of compounds consisting of substituted pyridin-2(1H)-ones(8a-c); 2-thioxo-2,3-dihydro-thiazoles(9a-d) and 2-thioxo-2,3-dihydro-6H-thiazolo[4,5-d]pyrimidin-7-ones (10a-c, 11a-c). The absolute configuration of compound 5c was determined by X-ray crystallography. The compounds prepared were evaluated for their in vitro anti-HIV, anticancer, antibacterial, and antifungal activities. Among the tested compounds, compounds 5c and 9a produced a significant reduction ㅐ ㄹ the viral cytopathic effect (93.19% and 59.55%) at concentrations $>2.0{\times}10^{-4}\;M\;and\;2.5{\times}10^{-5}\;M$respectively. Compound 9a was confirmed to have moderate anti-HIV activity. Compounds 2a, 2d, and 5c showed mild antifungal activity. However, none of the tested compounds showed any significant anticancer activity.

• Natural Product Sciences
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• v.10 no.1
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• pp.32-34
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• 2004

Two 2-phenoxychromones; a rare group of natural products, were isolated from the combined ethylacetate and chloroform fractions of the ethanolic extract of Ononis serrata frossk (Leguminosae) growing in Egypt. Structures were elucidated by chemical, spectroscopic methods as well as single X-ray diffraction analyses. The cytotoxic and antimicrobial effects of the two compounds were examined. It is worth to mention that this is the first report on the isolation of 2-phenoxychromones from the family Leguminosae.

• Archives of Pharmacal Research
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• v.25 no.3
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• pp.250-257
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• 2002

A series of benzimidazole derivatives carrying different heterocycles such as 1,2,3-thiadiazole, 1,3,4-thiadiazole, thiazolidine, 2,3-dihydro-thiazole, 1,3,4-oxadiazole, semicarbazone and substituted thiosemi-carbazones were synthesized. Also a series of 1-methylbenzimidazole carrying hydroxy ethyl-amide, substituted sulfonyl hydrazide and benzoyl hydrazide from aminobenzoyl group at position 2 of 1-methylbenzimidazole were synthesized. The antimicrobial evaluation of some of the new compounds was carried out.

• Proceedings of the Korean Society of Life Science Conference
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• 2008.10a
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• pp.65.1-65.1
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• 2008

• Proceedings of the Korean Society of Life Science Conference
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• 2008.10a
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• pp.66.1-66.1
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• 2008

• Archives of Pharmacal Research
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• v.24 no.1
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• pp.27-34
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• 2001

A series of 2-methylbenzimidazole incorporated to different heterocycles through ethyl or carbamoylethyl groups at position 1 of benzimidazole were synthesized. Also 3-(2-methylbenzimidazol-1-yl)propanoic acid hydrazide incorporated with semicarbazides and thiosemicarbazides were prepared. Moreover, the triazole 5e underwent Michael addition and alkylation reaction. Some of the newly synthesized compounds showed considerable antimicrobial activity against gram positive, negative bacteria and yeast.

• Journal of Microbiology and Biotechnology
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• v.19 no.4
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• pp.372-377
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• 2009

The chemical compositions and antibacterial and antifungal activities of essential oils extracted from Abies holophylla and A. koreana were investigated. GC-MS analysis revealed that 38 compounds comprised 95.88% of the A. holophylla essential oil, with the main components being bicyclo[2.2.1]heptan-2-ol(28.05%), ${\delta}3$-carene(13.85%), $\alpha$-pinene(11.68%), camphene(10.41%), dl-limonene(7.61%), $\beta$-myrcene(7.11%), trans-caryophyllene(5.36%), and $\alpha$-bisabolol(3.67%). In the essential oil from A. koreana, 36 compounds comprised 98.67% of the oil, and the main compounds were bornyl ester(41.79%), camphene(15.31%), $\alpha$-pinene(11.19%), dl-limonene(8.58%), fenchyl acetate(5.55%), and $\alpha$-terpinene(2.29%). Both essential oils showed great potential of antibacterial activity against several bacteria tested, in the range of 2.2-$8.8{\mu}g$ per disc by the agar disc diffusion method, and minimal inhibitory concentration(MIC) values of 5.5-21.8 mg/ml by the microdilution method. Both oils showed very effective antifungal activities toward all pathogenic strains tested, including Candida glabrata, with MIC values in the range of 0.5-2.2 mg/ml. As a whole, A. koreana oil showed better antibacterial and antifungal properties than A. holophylla oil.

• Journal of Applied Biological Chemistry
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• v.59 no.1
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• pp.19-23
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• 2016

A phenol substance was extracted from Pinus koraiensis Siebold et Zucc leaf extracts and its biological efficacy was measured. The highest content of the phenol substance contained in Pinus koraiensis Siebold et Zucc leaves was 13.5 mg/g, which was obtained when it was extracted with 80% ethanol. At a concentration of 200 mg/mL, the phenolic substances extracted with 80% ethanol and water showed antimicrobial activities against Helicobacter pylori, producing clear zones of 10 and 12 mm diameter, respectively. Pinus koraiensis Siebold et Zucc. leaf extracts were separated using a Sephadex LH-20 column and 4 fractions were obtained (fractions A-D). Fractions C and D showed the greatest inhibitory activity against Helicobacter pylori producing 10.1 and 12.3 mm clear zones, respectively. These two fractions were purified using a Sephadex LH-20 and MCI-gel column ($H_2O{\rightarrow}100%$ ethanol). Purified compounds A and B were identified as syringic acid and compound C was identified as p-coumaric acid based on $^1H$-nuclear magnetic resonance (NMR), $^{13}C$-NMR, and fast atom bombardment mass spectrometry spectra. When two or more purified compounds were mixed, a synergistic effect of anti-Helicobacter pylori activity was evident. This result indicates that extracts of Pinus koraiensis Siebold et Zucc leaves could be considered a functional food because of their high antimicrobial properties.

• YAKHAK HOEJI
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• v.52 no.4
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• pp.306-310
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• 2008

In vitro ${\beta}-lactamase$ inhibitory activity of 6-benzothiazole penicillins (1, 2, 3 and 4) was compared with clavulanic acid, sulbactam and tazobactam. The inhibitory activity of exomethylene compounds (3 and 4) was stronger than those of non-exomethylene compounds (1 and 2). The sulfide 3 showed stronger inhibitory activity than sulbactam, clavulanic acid andsimilar to tazobactam against ${\beta}-lactamase$ Type I enzymes. The inhibitory activity of 4 was stronger than those of sulbactam, clavulanic acid and tazobactam against Type III and IV enzymes. The in vitro antimicrobial activity of ampicillin or cefoperazone combined with 3 or 4 was stronger than those of ampicillin or cefoperazone alone against many ${\beta}-lactamase$ producing strains to show that compounds 3 and 4 have some synergistic effect. The synergistic activity of 3 and 4 was comparable to sulbactam in some ${\beta}-lactamase$ producing strains, but it was inferior to tazobactam.