• The Plant Pathology Journal
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• v.31 no.3
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• pp.278-289
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• 2015

Indigenous strains of Trichoderma species isolated from rhizosphere soils of Tea gardens of Assam, north eastern state of India were assessed for in vitro antagonism against two important tea fungal pathogens namely Pestalotia theae and Fusarium solani. A potent antagonist against both tea pathogenic fungi, designated as SDRLIN1, was selected and identified as Trichoderma viride. The strain also showed substantial antifungal activity against five standard phytopathogenic fungi. Culture filtrate collected from stationary growth phase of the antagonist demonstrated a significantly higher degree of inhibitory activity against all the test fungi, demonstrating the presence of an optimal blend of extracellular antifungal metabolites. Moreover, quantitative enzyme assay of exponential and stationary culture filtrates revealed that the activity of cellulase, ${\beta}$-1,3-glucanase, pectinase, and amylase was highest in the exponential phase, whereas the activity of proteases and chitinase was noted highest in the stationary phase. Morphological changes such as hyphal swelling and distortion were also observed in the fungal pathogen grown on potato dextrose agar containing stationary phase culture filtrate. Moreover, the antifungal activity of the filtrate was significantly reduced but not entirely after heat or proteinase K treatment, demonstrating substantial role of certain unknown thermostable antifungal compound(s) in the inhibitory activity.

• Microbiology and Biotechnology Letters
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• v.30 no.4
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• pp.339-345
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• 2002

Antifungal substances were isolated from solid cultures of Fusarium equiseti FO-68 obtained from arrowhead and Fusarium sp. FO-510 obtained from egg plant, and then their antifungal activities were investigated against plant pathogenic fungi in vitro and in vivo. An antifungal substance was purifed from rice solid cultures of F. equiseti FO-68 and identified as equisetin. In addition, two antibiotic substances were isolated from solid cultures of Fusarium sp. FO-510 and their chemical structures were determined to be zearalenone and 8'-hydroxyzearalenone. in vitro, equisetin and zearalenone inhibited mycelial growth of most of the plant pathogenic fungi tested, whereas 8'-hydroxyzearalenone hardly inhibited fungal growth. In vitro, equisetin effectively controlled the development of tomato gray mold and tomato late blight. Zearalenone exhibited in vivo antifungal activity against rice blast, rice sheath blight, tomato gray mold, and tomato late blight. However, 8'-hydroxyzearale-none did not control the development of plant diseases except tomato gray mold. This is the first report on the antifungal activities of equisetin, zearalenone, and 8'-hydroxyzearalenone.

• The Korean Journal of Pesticide Science
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• v.3 no.3
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• pp.37-44
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• 1999

Two sulphamide (dichlofluanid and tolylfluanid) and three dicarboximide fungicides (iprodione, vinclozolin, procymidone) were used to investigate the correlation between in vitro antifungal activities and in vivo disease controlling activities against Botrytis cinerea, a causal agent of tomato gray mold and to develop efficient in vitro assays. They controlled effectively the development of tomato gray mold disease in vivo and their controlling activities were similar one another. However, several in vitro assays revealed that their in vitro antifungal activities were quite different between sulphamide and dicarboximide fungicides; the formers showed stronger inhibition activities for spore germination than the latters, whereas the formers inhibited mycelial growth less severely than the latters. The results indicate that the fungicides having different modes of action can show different in vitro antifungal activities according to in vitro assays, even if they have similar in vivo disease controlling activities. On the other hand, two rapid and efficient in vitro assays named Microtiter plate methods I (MPM I) and II (MPM II) were developed for the evaluation of fungicides for inhibitory activities against spore germination and mycelial growth of B. cinerea, respectively. The antifungal activities of five fungicides of two chemical groups in MPM I and II were correlated with the inhibitory activities against spore germination and mycelial growth using solid media, respectively.

• Mycobiology
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• v.37 no.3
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• pp.243-246
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• 2009

In this study, the antifungal activities of limonene against Trichophyton rubrum were evaluated via broth microdilution and vapor contact assays. In both assays, limonene was shown to exert a potent antifungal effect against T. rubrum. The volatile vapor of limonene at concentrations above $1{\mu}l$/800 ml air space strongly inhibited the growth of T. rubrum. The MIC value was 0.5% v/v in the broth microdilution assay. The antifungal activity of limonene against T. rubrum was characterized as a fungicidal effect.

• Journal of Microbiology and Biotechnology
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• v.26 no.3
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• pp.610-617
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• 2016

Candidiasis has posed a serious health risk to immunocompromised patients owing to the increase in resistant yeasts, and Candida albicans is the prominent pathogen of fungal infections. Therefore, there is a critical need for the discovery and characterization of novel antifungals to treat infections caused by C. albicans. In the present study, we report on the antifungal activity of the ethanol extract from Salvia miltiorrhiza against C. albicans and the possible mode of action against C. albicans. The increase in the membrane permeability was evidenced by changes in diphenylhexatriene binding and release of both 260-nm-absorbing intracellular materials and protein. In addition, inhibition of cell wall synthesis was demonstrated by the enhanced minimal inhibitory concentration in the presence of sorbitol and reduced (1,3)-β-D-glucan synthase activity. The above evidence supports the notion that S. miltiorrhiza has antifungal activity against C. albicans by the synergistic activity of targeting the cell membrane and cell wall. These findings indicate that S. miltiorrhiza displays effective activity against C. albicans in vitro and merits further investigation to treat C. albicans-associated infections.

• Archives of Pharmacal Research
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• v.21 no.4
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• pp.440-444
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• 1998

A series of 6-(N-arylamino)-7-methylthio-5,8-quinolinedione derivatives 4a-4l was newly synthesized for the evaluation of antifungal activity. 6-(N-Arylamino)-7-methylthio-5,8-quinolinediones were prepared by regioselective nucleophilic substitution of 6,7-dichloro-5,8-quinolinediones with arylamines in the presence of $Ce^{3+}$, and $Na_2$S/dimethylsulfate. The MIC values of 4a-4l were determined for antifungal susceptibility in vitro against Candida species by agar streak method. The derivatives 4a-4l had generally potent antifungal activities against all human pathogenic fungi. Especially they had the most potent activity against C. krusei at 12.5-0.8 $\mu\textrm{g}$/ml. Compounds 4d, 4g, 4h, 4j and 4k had more potent antifungal activities than fluconazole. Compounds 4g and 4h completely inhibited the fungal growth at 0.8-6.3 $\mu\textrm{g}$/ml against all Candida species, while fluconazole inhibited the growth at 25 $\mu\textrm{g}$/ml. The compounds such as 4g and 4h containing an N-(4-bromo-2-methylphenyl)- or N-(4-bromo-3methylphenyl)amino substituent exhibited the most potent antifungal activities.

• YAKHAK HOEJI
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• v.57 no.2
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• pp.119-124
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• 2013

The aim of this present study was to investigate the antifungal effect of tanshinones isolated from Salvia miltiorrhiza against Candida ablicans, a polymorphic fungus. For the work, tanshinone IIA (TSN), cryptotanshinone (CTS), and dihydrotanshinone I (DTS) were chosen. Initially, their antifungal effect was analyzed by in-vitro susceptibility test. Data from the susceptibility test showed that while all of these three compounds had antifungal activity, DTS was the most potent. At $100{\mu}g$ DTS/ml, there was about 80% CFU (colony forming unit) reduction as compared to DTS-untreated C. albicans yeast cells (P<0.05). Thus, DTS was selected to determine its antifungal activity in a murine model of disseminated candidiasis due to C. albicans. Results showed that DTS enhanced resistance of mice against disseminated candidiasis. During the entire period of 30-day observation, 60% of DTS-given mice groups survived whereas control animals all died within 14 days (P<0.05). Moreover, DTS inhibited the hyphal production, one of the virulence factors of this fungus, from the blastoconidial form of the fungus. Therefore, the tanshinone appears to have antifungal activity specific for C. albicans infection, which could possibly be mediated by the blockage of hyphal production.

• Korean Journal of Organic Agriculture
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• v.14 no.4
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• pp.399-410
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• 2006

This study was carried out to identity the effects of antifungal bacteria isolated from the soil grown kiwi fruit plants on the growth inhibition of Botrytis cinerea causing gray mold in kiwi fruit plants in the southern districts of Jeonnam. Two hundred and fifty antagonistic microorganisms were isolated and examined into the antifungal activity against Botrytis cinerea. We screened and isolated four bacterial strains which strongly inhibited Botrytis cinerea from the soil grown kiwi fruit plants. And the best antifungal bacterial strain which called CHO 163 was finally selected. Antagonistic microorganism CHO 163 was identified to be the genus Bacillus sp. based on the morphological and biochemical characterization. Bacillus sp. CHO 163 showed 86.9% of antifungal activity against Botrytis cinerea. By the bacterialization of culture broth and heated filtrates of culture broth, Bacillus sp. CHO 163 showed almost all of antagonistic activity against Botrytis cinerea. And we also confirmed that in vitro the treatment of Bacillus sp. CHO 163 cultured by SD+B+P broth efficiently controled the growth of Botrytis cinerea causing gray mold in kiwi fruit plants.

• Microbiology and Biotechnology Letters
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• v.37 no.3
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• pp.273-279
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• 2009

Hyungbangjihwang-Tang (HT), an Oriental herbal formula, has been known to play a role which helps to recover vigor of human in the Orient. In this study, antifungal substance (HTI) was purified from the ethyl-acetate extracts of HT by using $SiO_2$ column chromatography and HPLC, and the antifungal effects of HTI and its mode of action were investigated. By using a broth micro-dilution assay, the activity of HTI was evaluated against fungi. HTI showed antifungal activities without hemolytic effect against human erythrocytes. To confirm antifungal activity of HTI, we examined the accumulation of intracellular trehalose as stress response on toxic agents and effect on dimorphic transition in Candida albicans. The results demonstrated that HTI induced the accumulation of intracellular trehalose and exerted its antifungal effect by disrupting the mycelial forms. To understand its antifungal mode of action, cell cycle analysis was performed with C. albicans, and the results showed HTI arrested the cell cycle at the S phase in yeast. The present study indicates that HTI has considerable antifungal activity, deserving further investigation for clinical applications.

• Archives of Pharmacal Research
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• v.29 no.7
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• pp.535-540
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• 2006

Several novel 1-[2-(1H-tetrazol-5-yl) ethyl]-1H-benzo[d][1,2,3]triazoles (3a-h) have been synthesized by the condensation of 1-[2-(1H-tetrazol-5-yl)-ethyl]-1H-benzotriazole (2) and appropriate acid chlorides. 1-[2-(1H-tetrazol-5-yl)-ethyl]-1H-benzotriazole (2) was synthesized by reacting 3-(1H-benzo[d][1,2,3]triazol-1-yl)propanenitrile with sodium azide and ammonium chloride in the presence of dimethylformamide. The synthesized compounds were characterized by IR and PMR analysis. The titled compounds were evaluated for their in vitro antibacterial and antifungal activity by the cup plate method and anticonvulsant activity evaluated by the maximal electroshock induced convulsion method in mice. All synthesized compounds exhibited moderate antibacterial activity against Bacillus subtilis and moderate antifungal activity against Candida albicans. Compounds 5-(2-(1 H-benzo[d][1,2,3]triazo-1-yl)ethyl)-1H-tetrazol-1-yl)(4-aminophenyl)methanone 3d and 5-(2-(1 H-benzo[d][1,2,3]triazo-1-yl)ethyl)-1H-tetrazol-1-yl)(2-aminophenyl)methanone 3e elicited excellent anticonvulsant activity.