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):
Ophelia whomever he wants. Ophelia's father, Polonius, who enters while Laertes is leaving, also forbids Ophelia from pursuing Hamlet, as Polonius fears that Hamlet is not earnest about her. In Ophelia's next appearance, she tells Polonius that Hamlet rushed into her room with his clothing askew and a "hellish" expression on his face; he only stared at her, nodding three times without speaking to her. Based on what Ophelia told him, Polonius concludes that he was wrong to forbid Ophelia from seeing Hamlet, and that Hamlet must be mad with love for her. Polonius immediately decides to go to Claudius, the