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 attention. Even more important was the question of decorum, which in the case of "Hamlet" focused on the play's violation of tragic unity of time and place, and on the characters. Jeremy Collier attacked the play on both counts in his "Short View of the Immorality and Profaneness of the English Stage", published in 1698. Comparing Ophelia to Electra, he condemns Shakespeare for allowing his heroine to become "immodest" in her insanity, particularly in the "Flower Scene". Collier's attack occasioned a widespread, often vituperative controversy. "Hamlet" in general and Ophelia in particular were defended by Thomas D'urfey and George Drake