Abstract:
Mosquitoes transmit devastating diseases that kill millions of people each year. The adverse effects on human health, well being and high economic losses inflicted by mosquitoes, the malaria vector, is an important stimulant for the search for new, safe and effective mosquito larvicides. The pool of natural products is an important source of such larvicidal metabolites. Fungi have extensive secondary metabolites at their disposal, and some could be active against the mosquito larvae. This project involved searching for larvicidal compounds from the submerged cultures of a basidiomycete JO5182. Initial screening of the crude extract from the basidiomycete showed good larvicidal activity (LC50 3.33 ppm, LC90 59.33 ppm). On purification using chromatographic methods, thirteen fractions from the crude extracts of the basidiomycetesJO5182 were obtained. Fractions: JO5182M03N (LC50 71.45 ppm, LC90 167.77), JO5182M06N (LC50 154.26 ppm, LC90 248.50 ppm) JO5182M07N (LC50 61.15, LC90) and JO5182K12N (LC50 129.49, LC90 230.26) displayed good larvicidal activity against the Aedes aegypti larvae. Three compounds; Methyl 2-hydroxy-4-methoxybenzoate (JO5182M10N), 3, 4- Dimethoxyphenol (JO5182K14N) and [(R)-(-)-8-hydroxy-3-methyl-3, 4-dihydro-1H-2- benzopyran-1-one] (JO5182K15N), were isolated and their structures determined using NMR spectroscopy. The larvicidal activity displayed by the extract from the basidiomycete JO5182 can be useful in the reduction of mosquito population which is on the rise and in the long run help in the elimination of malaria.
