Native Kenyan plants as possible alternatives to methyl bromide in soil fumigation
| Autor: | K.J. Rugutt, Paul K Ndalut, J.K. Rugutt, Anastasiah N. Ngigi |
|---|---|
| Rok vydání: | 2006 |
| Předmět: |
Warburgia ugandensis
Stereochemistry Fumigation Polygodial Pharmaceutical Science Microbial Sensitivity Tests chemistry.chemical_compound Fusarium Bromide Drug Discovery Fusarium oxysporum Organic chemistry Pharmacology Plants Medicinal Molecular Structure biology Plant Extracts Aspergillus niger Alternaria Azadirachta biology.organism_classification Kenya Fungicides Industrial Azadirachtin Complementary and alternative medicine chemistry Molecular Medicine Sesquiterpenes |
| Zdroj: | Phytomedicine. 13:576-583 |
| ISSN: | 0944-7113 |
| DOI: | 10.1016/j.phymed.2003.08.005 |
| Popis: | Methyl bromide (CH 3 Br) is a biocidal fumigant used widely in crop production and commodity preservation worldwide. CH 3 Br escapes to the stratosphere and releases bromine atom (Br), which contributes to significant destruction of the ozone (O 3 ). It is therefore necessary to explore alternatives to CH 3 Br that are environmentally safe and suitable for resource-poor African farmers. We present here the results of a study on the inhibitory activity of crude extracts from Kenyan medicinal plants against three soil pathogens, Fusarium oxysporum , Alternaria passiflorae , and Aspergillus niger. Crude organic extracts of Warburgia ugandensis Sprague, Azadirachta indica A. Juss, Tagetes minuta and Urtica massaica were active against all soil pathogens, while those from U. massaica were not. Chromatographic purification of the crude extract of W. ugandensis provided two pure compounds, muzigadial ( 1 ) and muzigadiolide ( 5 ). The minimum inhibitory concentration (MIC value) for muzigadial ( 1 ) ranged from 5 to 100 μg/ml. Muzigadiolide ( 5 ) was not active. Greenhouse tests of W. ugandensis extract s against F. oxysporium pathogen showed the most effective inhibitory concentration to be at least 5 mg/ml. Quantitative structure–activity relationship (QSAR) models were used to rationalize the variation in biological activities of muzigadial ( 1 ), warburganal ( 2 ), polygodial ( 3 ), ugandensidial ( 4 ), muzigadiolide ( 5 ), azadirachtin ( 6 ), and CH 3 Br. The models were based on several molecular descriptors including LogP, van der Waals surface area (VDW A ), van der Waals volume (VDW v ), dipole moment, total energy, polarizability, and differences between the highest occupied molecular orbital and the lowest unoccupied molecular orbital (HOMO–LUMO gap). |
| Databáze: | OpenAIRE |
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