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):
To Be or Not to Be (book) to Be" offers the reader the option to play as one of three characters: Hamlet, Ophelia, or Hamlet Sr., King of Denmark. From there the story branches frequently, with some options following the course of the original play and others providing the choice to give up on the quest to kill King Claudius, or to follow other pursuits (Ophelia, for example, is a keen scientist who can invent indoor heating, and King Hamlet, as a ghost, can choose to explore the ocean floor or tame the ghosts of dinosaurs). The choices that follow Shakespeare's play are marked with little "Yorick