Structure-activity relationship of 4-Hydroxycoumarins and related compounds

Abstract

Eight 4-hydroxycoumarins derived from the condensation between malonic acid and phenols or from the condensation of diethyl carbonate and 2-hydroxyacetophenes and twenty four dicoumarols obtained from nucleophilic substitution reaction between 4-hydroycoumarin and aromatic aldehydes were synthesized. These compounds were subjected for the examination for biological activities: insect antifeedant against greater wax moth larvae (Galleria mellonella Linn.) and weed growth inhibition against giant mimosa seedling (Mimosa pigra Linn.) It was found that there was indeed a significant relationship between the structures and biological activities. For insect antifeedant activity, 4-hydroxycoumarins with amethoxy froup at C-5(6) and various substituents at C-6 (2,4 and 5) and dicoumarols with a methoxy group on a benzylidene ring ( 15 and 16 ) inhibition, 4-hydroxycoumarins with methyl (2) and chloro (4) substituents at c-6 ans dicoumarols (14,17 and 18) with hydroxyl and methoxy substituents on a benzylidene ring showed nigh activity. Several compounds displayed the activity comparable to various commercial insecticides and herbicides in terms of antifeedant activity and growth inhibition activity tests, respectively. Some of them revealed promising tendency for the development as new agrochemicals.