• Journal of Microbiology and Biotechnology
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• 제15권4호
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• pp.895-898
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• 2005

In the course of searching for potent chitin synthase 1 inhibitors from natural resources, Streptomyces sp. A6705 was found to exhibit potent inhibitory activity against the chitin synthase 1 from C. albicans (CaCHS1p). As a result, the inhibitor was isolated and identified using a series of chromatographies. Through chemical analyses with UV spectrophotometry, MS spectrometry, and various NMR techniques, the inhibitor was identified as N,N-bis(2-phenylethyl)urea. The compound exhibited strong inhibitory activity against the chitin synthase 1 from C. albicans with an $IC_{50}$ of 14 ${\mu}g$/ml, representing a similar inhibitory activity to that of the well-known chitin synthase inhibitor, polyoxin D ($IC_{50}$ 15 ${\mu}g$/ml). However, the compound showed no inhibitory activity against the chitin synthase 2 of Saccharomyces cerevisiae up to 280 ${\mu}g$/ml, which is structurally and functionally analogous to CaCHS 1 p. In addition, the compound exhibited weak antifungal activities against Cryptococcus neoformans and Rhizoctonis solani.

• 대한화학회지
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• 제45권4호
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• pp.325-333
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• 2001

4-치환 tetrazolo[1,5-a]quinoxaline류는 4-chlorotetrazolo[1,5-a]quinoxaline(8) 또는 4hydra-zino-[1,5-a]quinoxaline(9)으로부터 합성하였다. N,N-디메틸포름아미드 용매에서 tetrazololo[1,5-a]quinoxaline(12)를 환류시켜 1,2,4-triazolo[3,4-c]tetrazolo[1,5-a]quinoxaline (13)을 합성하였으며, 이것은 N,N-디메틸포름아미드 용매에서 화합물 9와 ethyl chloroformate를 반응시켜도 합성할 수 있었다. 화합물 9를 isothiocyanate류와 반응시켜 tetrazololo[1,5-a]quinoxaline류(14)를 합성하였으며, 이것을 dimethyl acethylenedicarboxyla-te와 반응시켜 tetrazololo[1,5-a]quinoxaline류(15)를 합성하였다. 그리고 화합물 9를 alkyl (ethoxymethylene)-cyanoacetate류와 반응시켜 tetrazololo[1,5-a]quinoxaline류(18)를 합성하였다. 합성한 화합물 중에서 몇 가지는 몇 가지 균주에 대하여 항균성, 항진균성 도는 항조류성을 나타내었다.

• Bulletin of the Korean Chemical Society
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• 제26권5호
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• pp.719-728
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• 2005

A novel 2-amino-4-(8-quinolinol-5-yl)-1- (p-tolyl)-pyrrole-3-cabonitrile (2) was obtained by the reaction of 2-[2-bromo-1-(8-hydroxyquinolin-5-yl)-ethylidene]-malononitrile (1) with p-toluidene. The new synthon compound (2) could be annelated to the corresponding pyrrolo[2,3-d]pyrimidines (4, 6, 7, 26-28), triazolo[1,5-c]pyrrolo[3,2-e]pyrimidines (10, 29, 30), pyrrolo[2,3-c]pyrazoles (11-15), pyrrolo[1,2-a]pyrrolo[3,2-e] pyrimidine (17) and imidazo[1,2-c]pyrrolo[3,2-e]pyrimidines (18-25) via the reaction with some reagents such as acetic anhydride, formamide, triethyl orthoformate, hydrazine hydrate, hydroxylamine, ethylenediamine, carbon disulfide and phosphorus oxychloride. Chemical and spectroscopic evidences for the structures of these compounds are presented. The antifungal and antibacterial activity of the newly synthesized comounds were evaluated.

• 대한화학회지
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• 제55권5호
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• pp.794-804
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• 2011

3-Chloro-1-benzothiophene-2-carbonylchloride (1) was allowed to react with glycine to give 3-chloro-1-benzothiophen-2-yl-carbonylaminoacetic acid (2). Various aldehydes were treated with compound (2) in acetic anhydride to get 1,3-oxazol-5-ones (3a-d). These oxazolones were treated with aromatic amines or hydrazides to get various imidazol-4-ones (4a-h or 5al) separately. Oxazolones was also treated with aromatic hydrazine, through which expansion of five membered oxazole ring to six member triazine ring occurs to yield 1,2,4-triazin-6-ones (6a-h). The structures of all the synthesized compounds were confirmed by spectral data and were screened for antibacterial and antifungal activities.

• Journal of Microbiology
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• 제40권4호
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• pp.289-294
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• 2002

The fungal strain SW-3 having antimicrobial activity was isolated from soil of crucified plants in Pocheon, Kyungki-Do, Korea. Strain SW-3 was identified as Alternaria brassicicola by its morphological characteristics, and confirmed by the analysis of the 18S gene and ITS regions of rDNA. The fungus showed a similarity of 99% with Alternaria brassicicola in the 18S rDNA sequence analysis. A. brassicicola has been reported to produce an antitumor compound, called depudecin. We found that strain SW-3 produced antimicrobial metabolites, in addition to depudecin, during sporulation under different growth conditions. The metabolite of the isolated fungus was found to have strong antifungal activity against Microsporium canis and Trichophyton rubrum, and antibacterial activity against Staphylococcus aureus and Pseudomonas aerogenes. The amount and kind of metabolites produced by the isolate were affected by growth conditions such as nutrients and growth periods.

• Journal of Microbiology and Biotechnology
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• 제20권5호
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• pp.942-945
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• 2010

The ability of the human fungal pathogen Candida albicans to undergo the morphological transition from a single yeast form to pseudohyphal and hyphal forms in response to various conditions is known to be important for its virulence. Many studies have shown the pharmacological effects of resveratrol, a phytoalexin polyphenolic compound. In this study, we investigated the antifungal activity of resveratrol against C. albicans. Both yeast-form and mycelial growth of C. albicans were inhibited by resveratrol. In addition, normal filamentation of C. albicans was affected and yeast-to-hypha transition under serum-, pH-, and nutrient-induced hyphal growth conditions was impaired by resveratrol.

• 통합자연과학논문집
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• 제1권1호
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• pp.47-53
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• 2008

In a previous study, we showed that Cecropin A (1-8)-Magainin 2 (1-12) hybrid peptide (CA-MA)'s analogue, Anal P5, exhibit broad-spectrum antimicrobial activity. Anal P5, designed by flexible region (positions 9, 10)-substitution, Lys- (positions 4, 8, 14, 15) and Leu- (positions 5, 6, 12, 13, 16, 17, 20) substitutions, showed an enhanced antimicrobial and antitumor activity without hemolysis. The primary objective of the present study was to gain insight into the relevant mechanisms of antimicrobial activities of Anal P5 by using flow cytometric analysis. Anal P5 exhibits strong antifungal activity in a salt concentration independent manner. In addition, Anal P5 causes significant morphological alterations of the bacterial surfaces as shown by scanning electron microscopy, supporting its antibacterial activity. Its potent antibiotic activity suggests that Anal P5 is an excellent candidate as a lead compound for the development of novel antibiotic agents.

• 약학회지
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• 제16권4호
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• pp.162-175
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• 1972

Fifty six compounds of 4-methylthiosemicarbazone and thiorcarbohydrazone derivatives were prepared and subjected to biological tests. The following five compounds, 2-hydroxybenzaldehyde monothiocarbohydrazone (2),4-methylbenzaldehyde monothiocarbohydrazone (8), 1-(2-hydroxybenzaldehyde)-5(4-hydroxy-3-methoxybenzaldehyde) dithiocarbohydrazone (45), 1-(2-hydroxybenzaldehyde)-5-furfural dithiocarbohydrazone (46) and 1-benzaldehyde-5-cinnamaldehyde dithiocarbohydrazone (49) exhibited marked antimicrobial activity against E. coli, St. aureus and P. chrysogenum. In addition to these compounds, 3-methoxybenzaldehyde monothiocarbohydrazone (12) and 4-methylbenzaldehyde dithiocarbohydrazone (29) showed marked inhibition of HeLa cell growth at the concentration of 10 ${\nu}$g/ml. It was generally observed that most compounds demonstrated significant antifungal activity against P. chrysongenum but only one compound, 3-hydroxy-4-methoxybenzaldehyde dithiocarbohydrazone (39), exerted antituberculosis activity against M. tuberculosis H$_{37}$ RV at the concentration of 10 ${\nu}$g/ml.

• The Plant Pathology Journal
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• 제22권3호
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• pp.289-294
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• 2006

Two isolates of mucous bacteria, mc75 and pc78, were isolated from fungal culture plate as culture contaminants with an interesting swarming motility. Both isolates were identified as Pseudomonas fluorescens based on microscopy, biochemical analysis, Biolog test and DNA sequence analysis of the 16S rRNA gene. Both strains have the exactly the same 16S rRNA gene sequences, and yet their biological control activity were not identical each other. In vitro analysis of antagonistic activity of two isolates against several plant pathogenic fungi indicated that both produced diffusible and volatile antifungal compounds of unknown identities. Treatment of the bacterial culture of P. fluorescens pc78 and its culture filtrate exhibited a strong biological control activity against rice sheath blight in vivo among six plant diseases tested. More effective disease control activity was obtained from treatment of bacterial culture than that of culture filtrate. Therefore, in addition to antifungal compound and siderophore production, other traits such as biofilm formation and swarming motility on plant surface may contribute to the biological control activity of P.fluorescens pc78 and mc75.

• The Korean Journal of Ecology
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• 제25권5호
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• pp.353-358
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• 2002

소나무과 식물(곰솔, 리기다소나무 및 소나무)이 지닌 monoterpene의 표준시약 12가지를 4가지 농도별로 Escherichia coli와 Aspergillus nidulans에 처리하여 성장 저해 효과를 조사하였다. E. coli의 성장 저해 효과가 있는 것들은 (R)(-)carvone, (S)(+)carvone, (1R)(-)fenchone, (-)menthone, α-pinene, (1S)(-)verbenone 그리고 (+)β-pinene이었고, 이들 중에서 가장 높은 성장 저해 효과를 보이는 것은 (+)β-pinene이었다. 그리고 A. nidulans에 성장 저해 효과를 보이는 것들은 (R)(-)carvone, (S)(+)carvone, (+)β-pinene, geranyl-acetate, α-pinene 그리고 (1S)(-)verbenone이었다. 본 실험에서 A. nidulans에 성 장 저해 효과를 나타내는 monoterpene은 대부분 E. coli에서도 저해효과를 보이는데, 다만 geranyl-acetate는 E. coli에서는 전혀 영향을 미치지 않는 것으로 나타났다. 또한 (1R)(-)fenchone과 (-)menthone은 E. coli의 성장 억제를 하는 반면. A. nidulans의 성장에는 영향이 없었다. 특히 주목할 만한 점은 myrcene, sabinene, bornyl acetate 그리고 limonene의 경우 두 종 모두에서 성장 저해 효과가 전혀 나타나지 않았다.