Antifungal activity of crude extracts and fat-soluble constituents of Holotrichia diomphalia larvae

Late blight caused by Phytophthora infestans (Mont.) De Bary is one of the most devastating diseases of potato. Although a large number of synthetic fungicides have been recommended to control this organism, most of them have proved to be pollutive, carcinogenic and the pathogen develops resistance quickly. Botanical control is one of the safe substitutes to be explored to control this phytopathogen. In the present study an attempt has been made to evaluate the antifungal activity of plant extracts against the above pathogen. Crude ethanolic extracts of five different plant materials viz. Brassica nigra, Cinnamomum camphora, Eupatorium adenophorum, Lantana camara and Melia azedarach were screened and tested against the fungal isolate of P. infestans. The antifungal activity of the crude extracts was evaluated by agar well diffusion method and two fold broth dilution method. The moisture content was highest in the twigs of L. camara and lowest in the cake of B. nigra. C. camphora gave the highest yield of 70% while M. azedarach had the lowest yield of (9.75%) of crude extracts. B. nigra was found most effective against P. infestans with both MIC and MFC values at 6.25mg/ml while C. camphora was found least effective. Different types of plant extracts with different concentrations significantly (P<0.05) inhibited the growth of the pathogen. The extracts used in this experiment were found to be suitable for the control of the pathogen. Key words: botanical control; antifungal; MIC; ZOI; MFC DOI: 10.3126/njst.v11i0.4087Nepal Journal of Science and Technology 11 (2010) 37-40

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Bioactive Chemical Constituents and Comparative Antimicrobial Activity of Callus Culture and Adult Plant Extracts from Alternanthera tenella

Zeitschrift für Naturforschung C ◽

10.1515/znc-2009-5-612 ◽

2009 ◽

Vol 64 (5-6) ◽

pp. 373-381 ◽

Cited By ~ 5

Author(s):

Marcos J. Salvador ◽

Paulo S. Pereira ◽

Suzelei C. França ◽

Regina C. Candido ◽

Izabel Y. Ito ◽

...

Keyword(s):

Antimicrobial Activity ◽

Antifungal Activity ◽

Callus Culture ◽

Culture Media ◽

Chemical Constituents ◽

Adult Plant ◽

Antibacterial And Antifungal Activity ◽

Crude Extracts ◽

Antibacterial And Antifungal ◽

Adult Plants

Crude extracts of a callus culture (two culture media) and adult plants (two collections) from Alternanthera tenella Colla (Amaranthaceae) were evaluated for their antibacterial and antifungal activity, in order to investigate the maintenance of antimicrobial activity of the extracts obtained from plants in vivo and in vitro. The antibacterial and antifungal activity was determined against thirty strains of microorganisms including Gram-positive and Gram-negative bacteria, yeasts and dermatophytes. Ethanolic and hexanic extracts of adult plants collected during the same period of the years 1997 and 2002 [Ribeirão Preto (SP), collections 1 and 2] and obtained from plant cell callus culture in two different hormonal media (AtT43 and AtT11) inhibited the growth of bacteria, yeasts and dermatophytes with inhibition halos between 6 and 20 mm. For the crude extracts of adult plants bioassay-guided fractionation, purification, and isolation were performed by chromatographic methods, and the structures of the isolated compounds were established by analysis of chemical and spectral evidences (UV, IR, NMR and ES-MS). Steroids, saponins and flavonoids (aglycones and C-glycosides) were isolated. The minimum inhibitory concentration (MIC) of the isolated compounds varied from 50 to 500 μg/mL

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