Ruta graveolens the isolation of the furanocoumarin chalepensin. The essential oil of "R. graveolens" contains two main constituents, undecan-2-one (46.8%) and nonan-2-one (18.8%). The bitter taste of its leaves led to rue being associated with the (etymologically unrelated) verb "rue" "to regret". Rue is well known for its symbolic meaning of regret and it has sometimes been called "herb-of-grace" in literary works. It is one of the flowers distributed by the mad Ophelia in William Shakespeare's "Hamlet" (IV.5): It was planted by the gardener in "Richard II" to mark the spot where the Queen wept upon hearing news of Richard's capture (III.4.104–105):
Critical approaches to Hamlet with "self-reproaches" and "scruples of conscience, which remind him that he himself is literally no better than the sinner whom he is to punish". Freud goes on to suggest that Hamlet's apparent "distaste for sexuality", as expressed in his conversation with Ophelia (presumably in the 'nunnery scene' rather than during the play-within-a-play), "fits in well" with this interpretation. Since this theory, the 'closet scene' in which Hamlet confronts his mother in her private quarters has been portrayed in a sexual light in several performances. Hamlet is played as scolding his mother for having sex with Claudius while simultaneously wishing (unconsciously)