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):
Rockabye Hamlet then toured eastern Canada with Brent Carver as Hamlet and Beverly D'Angelo as Ophelia. Jones revised the show and retitled it Rockabye Hamlet for a Broadway production that was staged as an all-out rock concert directed and choreographed by Gower Champion. After 21 previews, it opened on February 17, 1976 at the Minskoff Theatre and closed after seven performances. D'Angelo reprised her role of Ophelia, and the rest of the cast included Larry Marshall as Hamlet, Alan Weeks as Claudius, Leata Galloway as Gertrude, Kim Milford as Laertes, Rory Dodd as Horatio, Meat Loaf as the Priest, and Christopher Chadman