• The Korean Journal of Pesticide Science
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• v.12 no.2
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• pp.111-117
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• 2008

The comparative molecular field analysis (CoMFA) for the fungicidal activity with N-phenylbenzenesulfonamide analogues (1-45) against gray mold (Botriyts cinerea) were studied quantitatively. The statistical values of CoMFA models had much better predictability and fitness than those of comparative molecular similarity indices analysis (CoMSIA) models. The statistical values of the optimized CoMFA I model were predictablity, $r^2_{cv.}(or\;q^2)=0.457$ and correlation coefficient, $r^2_{ncv.}=0.959$, and their fungicidal activity was dependent on the steric field (52%) and electrostatic field (35.6%) of the substrate molecules. And also, it was found that the optimized CoMFA I model with the sensitivity to perturbation ($d_q^{2'}/dr^2_{yy'}=0.898$) and prediction ($q^2=0.346$ & SDEP=0.614) produced by a progressive scrambling analysis was not dependent on chance correlation. From the results of graphical analyses on the contour maps with the optimized CoMFA I model, it is expected that the $R_3$ and $R_4$-substituents on the N-phenyl ring as steric favor group and para-substituents ($R_1$) on the S-phenyl ring as steric disfavor group will contribute to the fungicidal activity. Therefore, the optimized CoMFA I model should be applicable to the prediction of the fungicidal activities against gray mold.

• YAKHAK HOEJI
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• v.43 no.2
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• pp.221-227
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• 1999

The fungistatic and fungicidal activities of amphotericin B, fluconazole, miconazole, econazole, and 5-fluorocytosine against Saccharomyces cerevisiae were estimated in the presence of 1/2 minimum inhibitory concentration (MIC) and 1/2 minimum fungicidal concentration (MFC) of polygodial, respectively. Among them, the antifungal activities of miconazoles by polygodial was still shown against several yeast-like fungi including Candida albicans, Candida utilis, Cryptococcus neoformans, except for Candida krusei. The combination of polygodial with imidazole drugs against Saccharomyces cerevisiae was further examined using the macrobroth dilution checkerboard method. The fractional inhibitory concentration (FIC) and the fractional fungicidal concentration (FFC) index between polygodial and miconazole were 0.16 and 0.19, while the combination of polygodial with econazole exhibited the FIC index of 0.19 and the FFC of 0.25, respectively. These results suggest that polygodial and the imidazoles on the fungistatic and fungicidal action are highly synergistic.

• The Korean Journal of Pesticide Science
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• v.10 no.3
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• pp.157-164
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• 2006

Three dimensional quantitative structure-activity relationships (3D-QSARs) for the fungicidal activities against Rhizoctonia solani (RS) and Phytophthora capsici (PC) by N-phenyl substituents(X) of N-phenylthionocarbamate derivatives were studied quantitatively using comparative molecular field analysis (CoMFA) methodology based on different alignment approaches. Statistical quality of CoMFA models with field fit alignment were slightly higher than that of atom based fit alignment. The optimized CoMFA models (RS: RF2 & PC: PF2) were derived from field fit alignment and combination of CoMFA fields. And the statistical results of the two models showed the best predictability of the fungicidal activities based on the cross-validated value $q^2$ ($r^2_{cv.}$ =RS: 0.557 & PC: 0.676) and non-cross-validated value ($r^2_{ncv.}$ =RS: 0.954 & PC: 0.968), respectively. The selective fungicidal activities between two fungi were dependence upon the electrostatic field of substrate molecule. Therefore, the fungicidal activities from CoMFA contour maps showed that the fungicidal activity will be able to increased according to the modification of X-substituents on the substrate molecules.

• Natural Product Sciences
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• v.7 no.4
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• pp.114-119
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• 2001

The effect of Rhinacanthus nasutus leaf extract on the growth of dermatophytes had been investigated. In vitro the extract exhibited high activity against various species of dermatophytes (Trichophyton mentagrophytes var. mentagrophytes, T. mentagrophytes var. interdigitale, T. rubrum, Microsporum canis and M. gypseum). The minimal inhibitory concentration (MIC) values of the extract revealed that all the dermatophytes tested had MIC values of 13.6 mg/ml. The extract exhibited fungistatic activity at lower concentrations $({\leq}13.6\;mg/ml\;or\;below\;the\;MIC\;value)$ and fungicidal activity at higher concentrations $({\geq}13.6\;mg/ml$\;or\;above\;the\;MIC\;value)$. The results suggested that the extract acted on the cell wall of the dermatophytes which subsequently leading to the formation of cytopathological and membrane structural degeneration and finally leading to cell lysis and death.

• Journal of Microbiology and Biotechnology
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• v.17 no.8
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• pp.1324-1329
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• 2007

Resveratrol (3,5,4'-trihydroxystilbene) is a naturally occurring, multi-biofunctional chemical existing in grapes and various other plants as a polyphenol type, and it is one of the best known natural anticancer and antiatherosclerosis reagents. In this study, we investigated the antifungal action by resveratrol in Candida albicans, which is a human infectious fungi as an agent of candidiasis. Resveratrol displayed potent fungicidal activity in an energy-dependent manner, without any hemolytic effects against human erythrocytes. It was found that the serum-induced mycelial forms, which playa crucial role in the pathogenesis of C. albicans during host tissue invasion, were disrupted by resveratrol. To understand the correlation between lethal effects and resveratrol action, we examined the physiological changes of C. albicans. A significant accumulation of intracellular trehalose was induced by stress responses to resveratrol action, and a remarkable arrest of cell-cycle processes at the S-phase in C. albicans occured. Therefore, the fungicidal effects of resveratrol demonstrate that this compound is a potential candidate as an antifungal agent in treating infectious diseases by candidal infections.

• Bulletin of the Korean Chemical Society
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• v.33 no.5
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• pp.1703-1706
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• 2012

Rice blast is the most serious disease of rice due to its harmfulness and its world wide distribution. $Magnaporthe$ $grisea$ is the cause of rice blast disease and destroys rice enough to feed several tens of millions of people each year. Fungicides are commonly used to control rice blast. But $M.$ $grisea$ acquires resistance to chemical treatments by genetic mutations. 2-Phenylimino-1,3-thiazolines were proposed as a novel class of fungicides against $M.$ $grisea$ in the previous study. To develop compounds with a higher biological activity, a new series of 2-phenylimino-1,3-thiazolines was synthesized and its fungicidal activity was determined against $M.$ $grisea$. The QSAR analysis was carried out on a series of 2-phenylimino-1,3-thiazolines. The QSAR results showed the dependence of fungicidal activity on the structural and physicochemical features of 2-phenylimino-1,3-thiazolines. Our results could be used as guidelines for the study of the mode of action and further design of optimal fungicides.

• 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.

• Mycobiology
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• v.30 no.2
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• pp.93-95
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• 2002

The antifungal activities of propolis on Cryptococcus neoformans and Candida albicans were evaluated. In microbroth culture assay, the MIC(minimum inhibitory concentration) of propolis for C. neoformans and C. albicans were 2 and 16 mg/ml, respectively. In propolis-included solid medium assay, the MIC of propolis for C. neoformans and C. albicans were 4 and 16 mg/ml, respectively. Propolis showed fungicidal activity against C. neoformans, whereas propolis possesed fungistatic activity against C. albicans. The MFC(minimum fungicidal concentration) for C. neoformans was 8 mg/ml. Cell morphology of C. neoformans was affected by treatment of propolis. In scanning electron microscope, the appearance of cell rupture was observed.

• Applied Biological Chemistry
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• v.50 no.3
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• pp.187-191
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• 2007

Comparative molecular similarity indice analysis (CoMSIA) models on the fungicidal activities of N-phenyl substituents (X) in N-phenyl-O-phenylthionocarbamate derivatives against rice sheath blight (Rhizoctonia solani: RS) and phytophthora blight (Phytophthora capsici: PC) were derived. Also, the characterizations of H-bonds between substrates and ${\beta}-tubulin$ were discussed quantitatively. It was revealed that, from the contour maps of CoMSIA models, the H-bond acceptor field contributed the most highly to fungicidal activity for two fungi in common. It is predicted that the selectivity in the fungicidal activity between two fungi is caused by results from the roles of H-bond donor disfavor functional groups in RS and H-bond acceptor disfavor functional groups in PC when these two groups induced at meta- and para-position on the N-phenyl ring. And also, if the substituents (X) are steric disfavor group, negative charge favor groups are introduced at the metaposition in RS and H-bond acceptor group is introduced at the para-position in PC, the antifungal activity against two fungi will be likely able to be increased.

• Applied Biological Chemistry
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• v.38 no.4
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• pp.359-363
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• 1995

New ten N-[1-(benzotriazol-1-yl)alkyl]aniline(4) derivatives were synthesized and the crystal structure of 4h was shown by X-ray crystallography and the absolute configuration has been assigned as S form. The molecule crystallizes in the monoclinic system, space group $P2_{1}/n$. And the molecules in the crystal are linked with each other through the hydrogen bond $(N_{11}-H_{11}{\cdots}N3)$ with distance $2.300(11){\AA}$ The fungicidal activity($pI_{50}$) in-vitro against Botrytis cineria (BC), Phytophthora casici (PC) and Sclerotium cepinorum (SC) were determined by the agar dilution method. The structure activity ralationships (SAR) between structure of 4 and the activity were studied using a physicochemical parameters of substituents and multiple regression technique. Among these compounds, only the bromo group substituent(4f) showed higher activity, which depend on the hydrophobic(${\pi}$) of substituents. The relative orders of the activity are SC>BC> and PC, respectively. This implies that the activity is affected by the hydrophobic(${\pi}$) nature of the Z group rather than the X group. Linear free energy relationships(LFER) on the fungicidal activity with substituents has been also discussed.