• Korean Journal Plant Pathology
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• v.14 no.3
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• pp.191-202
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• 1998

About 300 actinomycetes were isolated from two forest and one sea-shore soil and tested for inhibitory effects on mycelial growth of six plant pathogenic fungi Magnaporthe grisea, Alternaria mali, Colletotrichum gloeosporioides, Phytophthora capsici, Fusarium oxysporum f. sp. cucumerinum, and Rhizoctonia solani. Among 300 actinomycetes tested, only 16 actinomycetes showed the antifungal activity against the test fungi. Isolate NH 50 was selected for production and purification of antifungal antibiotic substances. Actinomycete isolate NH 50 displayed the broad antifungal spectra against 11 plant pathogenic fungi. To identify actinomycete isolate NH 50, cultural characteristics on various agar media, diaminopimelic acid type, and morphological characteristics by scanning electron microscopy were examined. As a result, actinomycete isolate NH 50 was classified as a rare actinomycete that had LL-DAP type and did not produce spores. After incubation of isolate NH 50 in yeast extract-malt extract-dextrose broth, antifungal compound NH-B1 that inhibited mycelial growth of some plant pathogenic fungi was purified from the methanol eluates of XAD-16 resins by a series of purification procedures, i.e., silica gel flash chromatography, C18 flash chromatography, Sephadex LH-20 column chromatography, silica gel medium pressure liquid chromatography (MPLC), C18 MPLC, and high pressure liquid chromatography (HPLC). UV spectrum and 1HNMR spectrum of antifungal compound NH-B1 dissolved in methanol were examined. The antibiotic NH-B1 showed the major peaks at 230 and 271.2nm. Based on the data of 1H-NMR spectrum, NH-B1 was confirmed to be an extremely complex polymer of sugars called polysaccharides. The antibiotic NH-B1 showed strong antifungal activity against Alternaria solani and Cercospora kikuchi, but weak activity against M. grisea.

• The Korean Journal of Mycology
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• v.23 no.3 s.74
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• pp.232-237
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• 1995

Antifungal protein from the hemolymph of larvae of Tenebrio molitor in Korea was partially purified by $C_{18}$ open column chromatography and assayed for the activity spectrum using 3 kinds of yeast and 4 kinds of filamentous fungi. The crude antifungal protein showed static activity for a broad range of fungal species. Weak cidal effects were observed in growing yeast type cells, including Candida and Saccharomyces. The affected cells were changed from ovoid to swollen and spherical form in shape. For filamentous fungi including Aspergillus and Fusarium, the crude antifungal protein affected the spore germination and the hyphal growth but not the viability significantly.

• Mycobiology
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• v.49 no.1
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• pp.89-94
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• 2021

Forty-three (n = 43) endophytic fungi with different morphologic characteristics were from a medicinal plant Sceletium tortuosum, were utilized to investigate their antifungal effectiveness against pathogenic fungi. All fungal isolates exhibited antifungal activity against one or more pathogens in the dual culture test whereas only 33 fungal culture filtrates (77%) showed decent antifungal effect. Fusaria and Aspergillus were the dominate genus that displayed significant antifungal activity. Isolates GG02, GG09, ND15, and ND17 showed the broadest spectrum of antifungal activity. Furthermore, culture filtrate of Fusarium sp. DR08 exhibited a broad range of antifungal activity against all the pathogens. The results suggest endophytic fungi isolated from medicinal plant might be a source of novel bioactive molecules. To the best our knowledge, this is the first report on endophytic fungi isolated from native kougoed exhibiting antifungal activity against plant fungal pathogens.

• Journal of Life Science
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• v.19 no.11
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• pp.1672-1678
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• 2009

The purified antifungal substances produced by Bacillus amyloliquefaciens IUB158-03 was positive to ninhydrin but negative to aniline, suggesting that the antifungal substance could be a peptide. FAB-MS, UV adsorption spectrum, and amino acid composition analysis revealed that the molecular weight of the antifungal substance was 1042 and that maximal adsorption was at 220 nm and 277 nm. The antifungal substance was composed of $Asn_3$, $Gln_2$, $Ser_1$, $Gly_1$, and $Tyr_1$. The composition and structural characteristics of antifungal substance were analysed by $^1H$-NMR spectrum, $^1H$-COSY, HMQC, which revealed that the compound belongs to the iturin A family. Temperature and pH had little effect on the stability of the antifungal substance in the ranges of $-70{\sim}121^{\circ}C$ and pH 6.0~10.0, respectively. It showed strong antibiotic activity against fungi. An in vitro cytotoxicity test using NIH3T3 cell showed that the antifungal substance does not have cytotoxicity. The number of circulating leukocytes and the hematobiological analysis of the mice administered with the antifungal substances was similar to those of the control group, indicating no cytotoxicity in vivo. Therefore, the antifungal substances extracted from culture broth of Bacillus amyloliquefaciens IUB158-03 have future potential as biocontrol agents against plant diseases caused by fungi.

• YAKHAK HOEJI
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• v.42 no.6
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• pp.552-557
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• 1998

Acyl CoA synthetase inhibitor, was purified from the culture broth of a Bacillus sp. B-6, which had been isolated from soil, by chloroform extract, silica gel column chro matography and preparative TLC. The purified acyl CoA synthetase inhibitor showed higher Antifungal activity against C. al-bicans (MIC: 8${\mu}$g/ml). Though the analysis of UV spectrum, melting point, IR spectrum, Mass-spectrum, $^1H$-NMR and $^{13}C$-NMR spectrum, the inhibitor could be identified as phenazine-l-carboxylic acid.

• Microbiology and Biotechnology Letters
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• v.23 no.1
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• pp.98-103
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• 1995

During the screening of antifungal antibiotics from microbial metabolites, we selected Pseudomonas aeruginosa KGM-100 showing powerful antagonistic activity against various phytopathogenic fungi. Antibiotics KGM-100A and KGM-100B were purified from the culture broth of Pseudomonas aeruginosa KGM-100 by diaion HP-20 column chromatography, ethyl acetate extraction, silica gel column chromatography, preparative TLC and recrystallization. KGM-100A which was recrystallized in MeOH showed antimicrobial activities against a broad spectrum of fungi and bacteria. Physico-chemical properties of KGM-100A were determined and identified to be phenazine-l-carboxylic acid by UV, IR, $^{1}$H-NMR, $^{13}$C-NMR, mass spectrum, and elemental analyses.

• Journal of Microbiology and Biotechnology
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• v.10 no.4
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• pp.547-550
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• 2000

The yeast Williopsis californica was shown to secrete a unique broad-spectrum killer toxin (Wicaltin) with antifungal activity against 14 yeast genera, including yeast-like and mycelial forms of the human pathogens Candida albicans and Sporothrix schenkii. Agar diffusion bioassays indicated that its activity was more pronounced than the antifungal potential of frequently used antimycotics; 0.07 pmol Wicaltin showed the same toxicity as 0.2 pmol miconazole and 29 pmol clotrimazole. Since the toxin's primary target would appear to be the yeast cell wall, Wicaltin may be attractive in combatting clinically relevant yeast and fungal infections.

• Applied Biological Chemistry
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• v.42 no.4
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• pp.271-276
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• 1999

Several Streptomyces strains were tested for potent antifungal agents active against phytopathogenic fungi. Among the tested, S. hygroscopicus MJM1004 showed a potent antifungal activity when assayed using Candida albicans as indicator organism. With the strain of MJM1004, fermentation medium for the production of an antifungal agent was developed with varying carbon sources, nitrogen sources, and mineral elements, which resulted in the highest productivity in the medium containing 2% soybean meal, 1% glucose, 2% starch, 0.3% $CaCO_3$, 0.05% $MgSO_4{\cdot}7H_2O$, 0.05% $K_2HPO_4$. The active compound showed a broad spectrum of antifungal activity against several plant pathogenic fungi. The antifungal compound was purified and showed the physicochemical characteristics similar to azalomycin F complex in NMR and MS analysis.

• Korean Journal of Clinical Pharmacy
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• v.28 no.3
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• pp.181-187
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• 2018

Background: Posaconazole is a broad-spectrum triazole antifungal agent and the most recommended prophylactic antifungal agent for patients with acute myeloid leukemia (AML) undergoing induction chemotherapy. In this study, we evaluated the status and effectiveness of posaconazole as a prophylactic antifungal agent in pediatric patients receiving induction chemotherapy for AML. Methods: We retrospectively reviewed the electronic medical records of 36 pediatric patients with AML (between January 2013 and September 2017) at the Yonsei University Health System. Invasive fungal disease (IFD) was assessed as the primary endpoint of prophylactic antifungal effect. The secondary endpoints were incidence of fever, persistent fever despite the use of broad-spectrum antibiotics for 72 h, alteration of antifungal agent, intensive care unit admission, and death within 100 days. Results: Among the 36 patients, 18 patients used posaconazole, 12 were treated with suspension formula, and 6 of them were treated with tablets. Eighteen patients did not use antifungal agents prophylactically. The mean number of days of posaconazole administration was $26.8{\pm}16days$. IFD occurred in 2/18 (11.1%) patients in the no prophylaxis group and in 1/18 (5.6%) patients in the posaconazole group (p=0.49). Conclusion: Posaconazole is expected to be useful for the prevention of IFD in pediatric patients with AML undergoing induction chemotherapy. Prospective studies of the effectiveness of posaconazole prophylaxis should be conducted in more pediatric patients in the future.

• Journal of Microbiology and Biotechnology
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• v.22 no.3
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• pp.326-330
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• 2012

Antifungal metabolites were isolated from a culture of Pseudomonas aurantiaca IB5-10. Chemical structures of the metabolites were elucidated as phenazine-1-carboxylic acid (PCA; 1), 2-hydroxyphenazine (2-OH-PHZ; 2), and cyclo-(L-Pro-L-Val; 3), respectively, based on spectroscopic methods. Among them, 3 was isolated for the first time from this strain. The antifungal activities of 1-3 were evaluated against a variety of plant pathogens. To the best of our knowledge, the antifungal activities of 3 against plant fungal pathogens have been evaluated for the first time in this work. PCA (1) showed the most potent antifungal activities against Phytophthora capsici, Rhizoctonia solani AG-1(IA), and Pythium ultimum with MICs (${\mu}g/ml$) of less than 1.0, 1.3, and 2.0, respectively. On the other hand, 2-OH-PHZ (2) showed potent antifungal activity against R. solani AG-1(IA) with the MIC (${\mu}g/ml$) of 2.0, whereas it showed moderate antifungal activity against P. ultimum with the MIC (${\mu}g/ml$) of 50.0. In addition, 3 showed antifungal activity against only R. solani AG-1(IA).