• Journal of Microbiology and Biotechnology
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• v.16 no.3
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• pp.349-354
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• 2006

Furaneol, a key aroma compound found in strawberry, pineapple, and processed foodstuffs, has been known to possess various biological activities on animal models. In this study, the antimicrobial effects of furaneol against human pathogenic microorganisms were investigated. The results indicated that furaneol displayed a broad spectrum of antimicrobial activities against Gram-positive and Gram-negative bacteria and fungi without hemolytic activity on human erythrocyte cells. To confirm the antifungal activity of furaneol, we examined the accumulation of intracellular trehalose as a stress response marker on toxic agents and its effect on dimorphic transition of Candida albicans. The results demonstrated that furaneol induced significant accumulation of intracellular trehalose and exerted its antifungal effect by disrupting serum-induced mycelial forms. These results suggest that furaneol could be a therapeutic agent having a broad spectrum of antimicrobial activity on human pathogenic microorganisms.

• Journal of Microbiology and Biotechnology
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• v.24 no.10
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• pp.1337-1345
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• 2014

A novel antifungal protein produced by the fungal strain Penicillium citrinum W1, which was isolated from a Southwest Indian Ocean sediment sample, was purified and characterized. The culture supernatant of P. citrinum W1 inhibited the mycelial growth of some plant pathogenic fungi. After saturation of P. citrinum W1 culture supernatants with ammonium sulfate and ion-exchange chromatography, an antifungal protein (PcPAF) was purified. The N-terminal amino acid sequence analysis showed that PcPAF might be an unknown antifungal protein. PcPAF displayed antifungal activity against Trichoderma viride, Fusarium oxysporum, Paecilomyces variotii, and Alternaria longipes at minimum inhibitory concentrations of 1.52, 6.08, 3.04, and $6.08{\mu}g/disc$, respectively. PcPAF possessed high thermostability and had a certain extent of protease and metal ion resistance. The results suggested that PcPAF may represent a novel antifungal protein with potential application in controlling plant pathogenic fungal infection.

• Mycobiology
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• v.47 no.3
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• pp.329-334
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• 2019

Streptomyces blastmyceticus strain 12-6 was isolated from a forest soil sample of Cheonan area on the basis of strong antifungal activities against plant pathogenic fungi. Butanol extracts of the cultural filtrates were active against C. acutatum, C. coccodes, C. gloeosporioides, F. oxysporum, and T. roseum. Active fractions were prepared by thin layer chromatography using silica gel plate; 12-6-2 ($R_f$ 0.36), 12-6-3 ($R_f$ 0.44). Scanning electron microscopy showed that the active fractions caused a change in surface texture of fungal spores from smooth surface to wrinkled surface. The lethal effect on the spores of the active fractions varied from 56% to 100%. It was shown that the spores of C. acutatum were more sensitive to the antifungal fractions than the spores of F. oxysporum. Fluorescence staining using TOTO-1 indicated that the antifungal fractions could make the spores more sensitive to the fluorescence dye. Thus, it was suggested that antifungal agents prepared in this study exhibited the antifungal activity by damaging the plasma membrane of both fungal spores and hyphae. Identification of antifungal agents in the active fraction using GC-MS analysis revealed the presence of cyclo-(Leu-Pro) and 9-octadecenamide as major components that have already been known as antifungal substances.

• Mycobiology
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• v.42 no.1
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• pp.66-72
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• 2014

Roselle (Hibiscus sabdariffa L.) family Malvaceae is an important crop used in food, cosmetics and pharmaceutics industries. Roselle is cultivated mainly in Upper Egypt (Qena and Aswan governorates) producing 94% of total production. Root rot disease of roselle is one of the most important diseases that attack both seedlings and adult plants causing serious losses in crop productivity and quality. The main objective of the present study is to identify and characterize pathogens associated with root rot and wilt symptoms of roselle in Qena, Upper Egypt and evaluate their pathogenicity under greenhouse and field condition. Fusarium oxysporum, Macrophomina phaseolina, Fusarium solani, Fusarium equiseti and Fusarium semitectum were isolated from the natural root rot diseases in roselle. All isolated fungi were morphologically characterized and varied in their pathogenic potentialities. They could attack roselle plants causing damping-off and root rot/wilt diseases in different pathogenicity tests. The highest pathogenicity was caused by F. oxysporum and M. phaseolina followed by F. solani. The least pathogenic fungi were F. equiseti followed by F. semitectum. It obviously noted that Baladi roselle cultivar was more susceptible to infection with all tested fungi than Sobhia 17 under greenhouse and field conditions. This is the first report of fungal pathogens causing root rot and vascular wilt in roselle in Upper Egypt.

• Applied Biological Chemistry
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• v.41 no.8
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• pp.600-604
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• 1998

Methanol extracts from 53 species of oriental medicinal plants in 34 families were tested for their fungicidal activities against Pyricularia grisea, Rhizoctonia solani, Phytophthora capsici, Phytophthora infestans, Collectotrichum dematium, Botryospaeria dothidea, Fusarium oxysporum f. sp. cucumerinum, Botrytis cinerea, Puccinia recondita, and Erysiphe graminis. In in vitro study using impregnated paper disc method, the efficacy varied with both plant pathogen and plant species tested. Methanol extracts of Asarum sieboldii roots, Sinomenium acutum roots, Pinus densiflora leaves, Rheum undulatum root barks, Coptis japonica roots, and Phellodendron amurense barks showed potent fungicidal activities against the various pathogens when treated with 10 mg/disc. In a whole plant test, methanol extracts of P. densiflora leaves and roots and C. japonica roots were highly effective against a variety of plant pathogens. As a naturally occurring fungicide, P. densiflora- and C. japonica-derived materials could be useful as new fungicidal products against various plant diseases induced by plant pathogenic fungi.

• The Plant Pathology Journal
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• v.24 no.2
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• pp.202-206
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• 2008

Antifungal activity of Korean and Chinese lichen-forming fungi (LFF) was evaluated against plant pathogenic fungus of Colletotrichum acutatum, causal agent of anthracnose on hot pepper. This is the first attempt to evaluate antifungal activity of LFF, instead of lichen thalli, against C. acutatum. Total 100 LFF were isolated from the lichens with discharged spore method or tissue culture method. Among the 100 isolates, 8 LFF showed more than 50% of inhibition rates of mycelial growth of the target pathogen. Especially, Lecanora argentata was highly effective in inhibition of mycelial growth of C. accutatum at the rate of 68%. Antifungal activity of other LFF was in the order of Cetrelia japonica (61.4%), Ramalina conduplicans (59.5%), Umbilicaria esculenta (59.5%), Ramalina litoralis (56.7%), Cetrelia braunsiana (56.5%), Nephromopsis pallescensn (56.1%), and Parmelia simplicior (53.8%). Among the tested LFF, 61 isolates of LFF exhibited moderate antifungal activity against the target pathogen at the inhibition rates from 30 to 50%. Antifungal activity of the LFF against C. acutatum was variable at the species level rather than genus level of LFF. This study suggests that LFF can be served as a promising bioresource to develop novel biofungicides.

• Archives of Pharmacal Research
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• v.28 no.5
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• pp.557-560
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• 2005

Resveratrol, a phenolic antioxidant found in grapes, has been known to mediate various biological activities on the human body. In the present study, we tested the antifungal a ctivity of resveratrol against human pathogenic fungi before carrying out further studies to elucidate the antifungal mechanism(s) of resveratrol. Resveratrol displayed potent antifungal activity against human pathogenic fungi at concentration levels of 10-20 ${\mu}g$/mL. Furthermore, time-kill curve exhibited fungicidal effect of resveratrol on C. albicans, but the compound had no hemolytic activity against human erythrocytes. The destruction of C. albicans cells by resveratrol was confirmed by scanning electron microscopy. These results suggest that resveratrol could be employed as a therapeutic agent to treat fungal infections of humans.

• The Korean Journal of Mycology
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• v.26 no.1 s.84
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• pp.78-85
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• 1998

During the screening of biological control agents for insect pests in the greenhouse, 70 dead insect-related fungi were isolated and tested insecticidal effect of their culture filtrates was tested. From this studies, CNAB-63 isolate showed strong control effects against the cotton aphids and the two-spotted spider mite as 65.19% and 77.55%, respectively. The insecticidal active compound of CNAB-63 isolate was purified from culture filtrate by silica gel chromotography, thin layer chromatography and HPLC. Purified active compound (CNAB) showed control effects against the two-spotted spider mite with 63.45% at $100\;{\mu}g/ml$ concentration. However, it did not exhibit antimicrobial activity against fungi and bacteria.

• Proceedings of the Microbiological Society of Korea Conference
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• 2005.05a
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• pp.191.2-191
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• 2005

• Proceedings of the Korean Society of Plant Pathology Conference
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• 1999.04a
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• pp.31.3-31
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• 1999