• Journal of Microbiology and Biotechnology
• /
• v.12 no.6
• /
• pp.1022-1025
• /
• 2002

Club root is one of the major diseases that occur in crucifers. It is caused by Plasmodiophora brassicae. In order to discover microbial biopesticides against P. brassicae, forty-eight Streptomyces isolated from soil were screened. Among these, three strains showed excellent pesticidal activities. We report results on in vivo screening with fermentation broths of these strains and identification of the strain taxa.

• Journal of Microbiology and Biotechnology
• /
• v.11 no.6
• /
• pp.1120-1123
• /
• 2001

Screening tests against six plant pathogenic fungi were performed in order to develop biopesticides. Actinomycetes were used to discriminate Bacillus thuringiensis for wide use as a microbial pesticide. From more than 100 actinomycetes tested, twelve strains showed potent antifungal activities. We report in vivo screening results from fermentation broths of these twelve strains and identification of the strain taxa.

• YAKHAK HOEJI
• /
• v.40 no.1
• /
• pp.90-94
• /
• 1996

6-[(N-4-Fluorophenyl)amino]-7-chloro-5,8-quinolinedione(RCK3) was tested for antifungal activities, in vivo, against Candida albicans. RCK3 was compared with ketoc onazole and fluconazole in the treatment of systemic infection with Candida albicans in normal mice. The therapeutic potential of RCK3 had been assessed by evaluating their activities (survival rate) against systemic infections in normal mice. RCK3 had $ED_{50},\;8.78{\pm}0.18mg/kg$ but ketoconazole and fluconazole had $ED_{50},\;8.00{\pm}0.73,\;10.00{\pm}0.43mg/kg$ respectively. Intraperitoneally administered RCK3 at the $ED_{50}$, 8.78mg/kg for 7 days and 14 days reduced Candida albicans colony count in the kidneys and livers as well as ketoconazole and fluconazole at these $ED_{50}$, 8.00 and 10.00mg/kg. And administered RCK3 at the $ED_{50}$ for 14 days improved survival rates better than ketoconazole.

• Journal of Microbiology and Biotechnology
• /
• v.16 no.3
• /
• pp.491-495
• /
• 2006

Methanol extracts of fruits of 67 plants were screened for in vivo antifungal activity against Magnaporthe grisea, Corticium sasaki, Botrytis cinerea, Phytophthora infestans, Puccinia recondita, and Blumeria graminis f. sp. hordei. Among them, 13 plant extracts ($3,000\;{\mu}g/ml$) showed more than 90% disease-control efficacy against at least one of six plant diseases. Specifically, the extracts of Aleurites fordii, Angelica dahurica, Camellia japonica, Chamaecyparis pisifera, Pittosporum tobira, and Styrax japonica controlled more than 90% of the development of rice blast at $1,000{\mu}g/ml$. Extracts of both S. japonica and A. dahurica fruits at $333{\mu}g/ml$ concentration displayed strong antifungal activity against M. grisea on rice seedlings.

• Journal of Microbiology and Biotechnology
• /
• v.12 no.6
• /
• pp.1026-1028
• /
• 2002

Screening tests against fungus causing rice blast, Magnaporthe grisea, were performed in order to develop biopesticides. More than 400 actinomycetes collected at several sites near Hanla Mountain on Jeju Island, Korea were tested, and strain BG2-53 showed potent antifungal activity. The in vivo screening was performed with fermentation broth, and the strain taxon was identified.

• Journal of Microbiology and Biotechnology
• /
• v.14 no.2
• /
• pp.422-425
• /
• 2004

To discover a potent strain against wheat leaf rust, soil samples collected from Ilgamho, Seoul, Korea were tested in vivo and a strain belonging to Streptomyces sp. was found to show good antifungal activity when fermented in a broth. The identification of the strain was carried out based on 16S rDNA analysis, and the active compound was separated from the fermented broth. Even though its structure was not determined completely, the authors report the results obtained so far indicate that the fermented broth of the strain showed activity against wheat leaf rust. Therefore, we propose that this may be a potential novel strain showing antifangal activity against Puccinia recondita.

• The Korean Journal of Pesticide Science
• /
• v.10 no.4
• /
• pp.249-261
• /
• 2006

Fifty compounds such as ester, sulfonyl ester, carbamate, ether and phosphoyl ester derivatives of 4-isopropyl-3-methylphenol(I) and 5-isopropyl-3-methylphenol(II) were synthesized. These derivatives were identified by IR, GC/MS and $^1H$-NMR spectra. Their in vitro antifungal activities were tested against 10 plant pathogenic fungi. Among them, several compounds showed potent in vitro antifungal activity. The selected compounds showing potent in vitro antifungal activity were tested for their in vivo antifungal activities against 5 plant diseases such as rice blast, rice sheath blast, cucumber anthracnose, cucumber gray mold and tomato late blight. As a result, 4-isopropyl-3-methylphenyl(2-amino-thiazole-4-yl)methoxyiminoacetate(I-7a) showed a potent in vivo antifungal activity against rice blast. Both methyl (4-isopropyl-3-methylphenoxy)acetate(I-4d) and methyl (5-isopropyl-3-methylphenoxy)acetate(II-4d) effectively inhibited the development of cucumber gray mold.

• Archives of Pharmacal Research
• /
• v.19 no.3
• /
• pp.197-200
• /
• 1996

6-[(N-2,3-Dichlorophenyl)aminol-7-chloro-5,8-quinolinedione (RCK1 1) was tested for in vivo antifungal activities in the treatment of systemic infection with Canclicla albicans in normal mice compared with ketoconazole. The therapeutic potential of RCK11 had been assessed by evaluating their activities (survival rates) against systemic infections in normal mice. $ED_{50}$ of intraperitoneally administered RCK11 was $0.10\pm0.01 mg/kg$ but that of ketoconazole had $8.00\pm0.73 mg/kg$ respectively. When RCK11 was administered intravenously at the $ED_{50}$(0.10 mg/kg), the colony counts of Canoliola albicans in the liver after 7 days and 14 days were reduced as likely as ketoconazole at the $ED_{50}$ (8.00 mg/kg), and the better survival rates than ketoconazole were achieved after 14 days. The results suggest that RCK11 may be a potent antifungal agent.

• Mycobiology
• /
• v.31 no.3
• /
• pp.179-182
• /
• 2003

A total of 187 endophytic fungi were isolated from 11 plant species, which were collected from 11 locations in Korea. Their antifungal activities were screened in vivo by antifungal bioassays after they were cultured in potato dextrose broth and rice solid media. Antifungal activity against plant pathogenic fungi such as Magnaporthe grisea(rice blast), Corticium sasaki(rice sheath blight), Botrytis cinerea(tomato gray mold), Phytophthora infestans(tomato late blight), Puccinia recondita(wheat leaf rust), and Blumeria graminis f. sp. hordei(barley powdery mildew) was determined in vivo by observing the inhibition of plant disease development. Twenty(11.7%) endophytic fungi fermentation broths were able to control, by more than 90%, at least one of the six plant diseases tested. Among 187 liquid broths, the F0010 strain isolated from Abies holophylla had the most potent disease control activity; it showed control values of more than 90% against five plant diseases, except for tomato late blight. On the other hand, fourteen(7.5%) solid culture extracts exhibited potent disease control values of more than 90% against one of six plant diseases. The screening results of this study strongly suggested that metabolites of plant endophytic fungi could be good potential sources for screening programs of bioactive natural products.

• Journal of Food Hygiene and Safety
• /
• v.14 no.1
• /
• pp.55-59
• /
• 1999

6-(4-Iodophenyl)amino-7-chloro-5,8-quinolinedione (RCK9) was evaluated for antifungal activities. The MIC values of RCK9 were determined against A. flavus, c. albicans, C. neoformans and F. oxysporium. The RCK9 showed generally potent antifungal activities against the tested fungi. Acute oral toxicity studies of RCK9 were carried out in ICR mice of both sexes. These acute oral toxicities of RCK9 had been evaluated. RCK9 were low and LD50 values were over 2,850 mg/kg in ICR mice. The genotoxicities of RCK9 had been evaluated. RCK9 was negative in Ames test with Salmonella typhimurium and chromosomal aberration test in CHL cells. The clastogenicity was tested on the RCK9 with in vivo mouse micronucleus assay. RCK9 did not show any clastogenic effect in mouse peripheral blood and was negative in mouse micronucleus assay. The results indicate that RCK9 has no genotoxic potential under these experimental conditions.