Active compound isolated from Dioscorea japonica roots with fumigant activity against house dust and stored food mites

Abstract

The acaricidal activity of essential oil from Dioscorea japonica roots against house dust and stored food mites was examined using the impregnated fumigant bioassay. The active component of D. japonica roots, isolated by silica gel column chromatography and high performance liquid chromatography, was identified as 2-hydroxy-4-methoxyacetophenone on the basis of spectroscopic analyses. Lethal dose 50 (LD50) values of 2-hydroxy-4-methoxyacetophenone were 1.29 and 1.78 μg/cm3 against Dioscorea farinae and Dioscorea pteronyssinus, respectively. The acaricidal activity of 2-hydroxy-4-methoxyacetophenone against Tyrophagus pteronyssinus was 2.28 μg/cm3. Compared to the commercial acaricide N,N-diethyl-m-toluamide (DEET), 2-hydroxy-4-methoxyacetophenone was found to be 19.52, 10.17, and 5.96 times more toxic against D. farinae, D. pteronyssinus, and T. putescentiae, respectively. These results suggest that 2-hydroxy-4-methoxyacetophenone may be useful as a preventive agent to control the growth of house-dust and stored-food mite populations.