• Korean Journal of Pharmacognosy
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• v.35 no.3 s.138
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• pp.189-193
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• 2004

In order to find some lead compounds for the treatment of opportunistic infections of malaria and pathogenic microbes, an undescribed Indonesian sponge Agelas sp. collected at Manado, Indonesian Waters, was suggested containing active compounds. Crude ethanolic extract of the sponge exhibited significant in vitro antimalarial and antimicrobial activity against Plasmodium falciparum (D6 colne) with $IC_{5O}$ values of $8\;{\mu}/ml$ and against pathogenic microbes such as Candida albicans $(150\;{\mu}/ml)$, Cryptococcus neoformans $(<20\;{\mu}/ml)$, Staphylococcus aureus $25\;{\mu}/ml$, methicillin-resistant Staphylococcus aureus $(<20\;{\mu}/ml)$, and Pseudomonas aeruginosa $(<20\;{\mu}/ml)$. Active compound (5.0 mg) was isolated from the ethanolic extracts of the sponge and purified by using silica gel and ODS column, successively. Active compound was elucidated as dibromosceptrin $(C_{22}H_{24}Br_2N_{10}O_2)$ by detailed analysis of FTESI-MS and comparison of $^1H,\;^{13}C$, DEPT and HMQC NMR spectral data with those reported.

• YAKHAK HOEJI
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• v.15 no.3_4
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• pp.93-97
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• 1971

Seventeen novel compounds of thiosemicarbazone derivatives were synthesized and evaluated for their in vitro antitubercular activity against Mycobacterium tuberculosis H$_{37}$Rv and antibacterial activity against Staphylococcus aureus, Escherichia coli. It was found that 4-($\alpha$-naphthyl)-1-(2-furfuraldehyde)-3-thiosemicarbazone was active at 0.01$\mu$g/ml and 1, 1'-(p-phenylene)-4, 4'-bis(phenyl)-2, 2'-dithiosemicarbazide, at 0.01$\mu$g/ml against E. coli, respectively.

• Korean Journal of Organic Agriculture
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• v.23 no.4
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• pp.887-896
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• 2015

To develop environment-friendly agricultural products with anti-microbial activity against Sclerotinia sclerotiorum as a pathogen of sclerotium disease, Usnea longissima was extracted by methanol and its extract was fractionated into several solvent fractions. The chloroform fraction, which showed the highest antimicrobial activity, was separated by silica gel-column chromatography and obtained into nine group subfractions. The nine group fractions were searched the antifungal activities by bioassay. The most active No. 3 subfraction was analyzed by GC-MS. Each mass spectra, corresponding to each peak of chromatogram, was compared to database of Wiley library. As a result, Usnic acid was identified as main compounds. In conclusion, Usnic acid isolated from Usnea longissima was antimicrobial chemical against Sclerotinia sclerotiorum as a pathogen of sclerotium disease.

• 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.

• Journal of Environmental Health Sciences
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• v.7 no.2
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• pp.107-111
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• 1981

Thirteen Carbanilides, P-chloro, bromo, methyl, ethyl, methoxy and ethoxy carbanilides, 4,4'-dichlorocarbahilide, and 4-bromo, methyl, ethyl, methoxy and ethoxy 4'-chlorocarbanilides have been newly synthesized by reacting P-phenetidime, P-anisidime, anilime, P-chloroanilime, P-bromoanilime, P-methoxy aniline, and P-ethoxy anilime with phenyl and P-chlorophenyl isocyanate, respectively. The compounds generally exhibited antibacterial activity against Escherichia coli, and staphylococcus aureus. The results obtained were as follows 4-chlorocarbanilide and 4,4'-clichlorocarbanilide were active against Eschrichia Coli, and Staphylococcus aureus at the concentration of 50 ug/ml. 4-methyl-4'-chloro carbanilide, and 4-ethoxy-4'-chloro carbanilide were active against Escherichia Coli at the concentration of 100ug/ml. 4-methyl-4'-chloro canbanilide were active against Staphylococcus aureus at the concentration of 50ug/ml.

• Journal of Microbiology and Biotechnology
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• v.23 no.6
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• pp.771-778
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• 2013

Essential oils are increasingly of interest for use as novel drugs acting as antimicrobial and antiviral agents. In the present study, we report the in vitro antiviral activities of 29 essential oils, extracted from Chinese indigenous aromatic plants, against the tobacco mosaic virus (TMV). Of these essential oils, those oils from ginger, lemon, tea tree, tangerine peel, artemisia, and lemongrass effected a more than 50% inhibition of TMV at 100 ${\mu}g/ml$. In addition, the mode of antiviral action of the active essential oils was also determined. Essential oils isolated from artemisia and lemongrass possessed potent inactivation and curative effects in vivo and had a directly passivating effect on TMV infection in a dose-dependent manner. However, all other active essential oils exhibited a moderate protective effect in vivo. The chemical constitutions of the essential oils from ginger, lemon, tea tree, tangerine peel, artemisia, and lemongrass were identified by gas chromatography and gas chromatography-mass spectrometry. The major components of these essential oils were ${\alpha}$-zingiberene (35.21%), limonene (76.25%), terpinen-4-ol (41.20%), limonene (80.95%), 1,8-cineole (27.45%), and terpinolene (10.67%). The curative effects of 10 individual compounds from the active essential oils on TMV infection were also examined in vivo. The compounds from citronellal, limonene, 1,8-cineole, and ${\alpha}$-zingiberene effected a more than 40% inhibition rate for TMV infection, and the other compounds demonstrated moderate activities at 320 ${\mu}g/ml$ in vivo. There results indicate that the essential oils isolated from artemisia and lemongrass, and the individual compound citronellal, have the potential to be used as an effective alternative for the treatment of tobacco plants infected with TMV under greenhouse conditions.

• Journal of Society of Preventive Korean Medicine
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• v.9 no.1
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• pp.135-141
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• 2005

Bioassay-directed fractionation of the dired roots of Sophorae Radix led to the isolation of Sophoraflavanone G. Their structures were elucidated using 1H-NMR, 13C-NMR, UV, IR and mass spectral ananlyses. These compounds exhibited a moderate antimicrobial activities against Streptococcus gordonii, Actinobacillus actinomycetemoomitans and Porphylomonas gingivalis.

• The Plant Pathology Journal
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• v.27 no.4
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• pp.342-348
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• 2011

Bacillus subtilis EBS05, an endophytic bacteria strain isolated from a medicinal plant Cinnamomum camphor, can produce antagonistic compounds that effectively inhibit plant pathogenic fungi. The greenhouse experiments showed that wheat sharp eyespot disease (WSED) was reduced by 91.2%, 88.2% and 43.0% after the treatment with fermentation broth, bacteria-free filter and a fungicide fludioxonil, respectively. The culture broth of strain EBS05 can more effectively control WSED than can fludioxonil. The fermentation broth and bacteria-free filter ability to suppress WSED was not significantly different, suggesting that an active secreted substance played a major role in controlling WSED. Separation and purification of the active compounds was carried out by serial processes, including hydrochloric acid (pH 2.0) treatment, methanol extraction and Sephadex LH-20 column chromatography, silica gel column chromatography and reverse-phase high-pressure liquid chromatography (HPLC), respectively. The purified compounds, one of active peaks in the HPLC spectrum, were obtained from the collection. Analysis of the chemical structures by time-of-flight mass spectrometry (TOF-MS) and electrospray ionization mass spectrometry/mass spectrometry (ESI-MS/MS) showed that the active substances produced by the endophytic bacteria EBS05 are mixture of the ${\beta}$-hydroxy-C12~C15-$Leu^7$ surfactin A isomers with 1035.65 Da, 1021.64 Da, 1007.63 Da and 993.65 Da molecular weights, respectively.

• Mycobiology
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• v.44 no.4
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• pp.338-342
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• 2016

The culture filtrate of Lentinula edodes shows potent antimicrobial activity against the plant pathogenic bacteria Ralstonia solanacearum. Bioassay-guided fractionation was conducted using Diaion HP-20 column chromatography, and the insoluble active compound was not adsorbed on the resin. Further fractionation by high-performance liquid chromatography (HPLC) suggested that the active compounds were organic acids. Nine organic acids were detected in the culture filtrate of L. edodes; oxalic acid was the major component and exhibited antibacterial activity against nine different phytopathogenic bacteria. Quantitative analysis by HPLC revealed that the content of oxalic acid was higher in the water extract from spent mushroom substrate than in liquid culture. This suggests that the water extract of spent L. edodes substrate is an eco-friendly control agent for plant diseases.

• Korean Journal of Organic Agriculture
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• v.23 no.2
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• pp.323-334
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• 2015

This study was conducted to develop environment-friendly agricultural products with anti-microbial activity against Acidovorax avenae subsp. citrulli as a pathogen of bacterial fruit blotch in cucurbit. Schlechtendalia chinensis was extracted by MeOH and solvent fraction. The hexane fraction, which showed highest value of anti-microbial activity, was analyzed by GC-MS. Each mass spectra, corresponding to each peak of chromatogram, was compared to MS database of Wiley library. As a result, myristic acid, palmitic acid and 3-n-pentadecylphenol were identified as maine compounds showing antimicrobial activity against A. avenae subsp. citrulli. Bioassay using commercial myristic acid, palmitic acid and 3-n-pentadecylphenol to test for the anti-microbial activity conformed the anti-microbial activity of potential active compounds, and myristic acid and 3-n-pentadecylphenol showed strong activity. In conclusion, myristic acid and 3-n-pentadecylphenol identified from S. chinensis were anti-microbial chemicals.