Coumarin derivatives from Esenbeckia grandiflora and its larvicidal activity against Aedes aegypti

From a hexane fraction prepared from the roots of Esenbeckia grandiflora Mart., effective against fourth instar larvae of Aedes aegypti L. (LC50 108.23 ppm), eight coumarin derivatives [daphnetin 7-methyl-8-(3,3-dimethylallyl) ether, a mixture containing pimpinellin eight one of its photodimerization product, 5-senecloylxanthotoxin, 3-(1',1')-dimethylallylcolumbianetin, swietenocoumarin B, isopimpinellin, xanthotoxin, and 5-(1'-hydroxyisopentenyl)bergapten] were isolated in addition to sitosterol and sitostenone. The mixture containing pimpinellin and its photodimerization product was effective against fourth instar larvae (LC50 at 45.77 ppm), and a mixture of pimpinellin and swietenocoumarin B showed a LC50 value of 62.23 ppm. All isolated compounds were identified on the basis of the spectral data including 2D experiments. Furthermore, previously unreported spectral data for some compounds are given.