The crude n-hexane and methanol extracts of the aerial parts of plant, Pimpinella monoica Dalz. (Umbelliferae) showed significant feeding deterrency to Spodoptera litura F. larvae. Phytochemical investigation of these extracts has resulted into the isolation of one furanocoumarin and five biogenetically related furanochromones. Furanocoumarin, isopimpinellin was found to be most active. Furochromones, visnagin and khellin exhibited significant activity while their hydroxymethyl analogues, khellol and ammiol showed moderate activity. α-Hydroxyisopropyldihydrofurochromone, visamminol was found to be least active.
