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):
Hamlet (Tchaikovsky) Elsinore, but there is an obvious love theme, and a plaintive melody on the oboe can be seen to represent Ophelia. What makes "Hamlet" unique from other works of Tchaikovsky fantasy is the lack of a structural development. The standard form of this music has an exposition, a development, and concludes with a recapitulation. Tchaikovsky did not clearly emphasize a development section in "Hamlet." There is no section that fulfills the duties of a development, causing "Hamlet" to be a unique piece that is of linear, not symmetrical, structure. The "Hamlet" overture-fantasia was dedicated to Edvard Grieg, whom Tchaikovsky had