(3S,9S,12S,15R,18S)-15-(Cyclohexylmethyl)-9-(3-guanidinopropyl)-12-(1H-indol-3-ylmethyl)-3-(L-phenylalanylamino)-1,7,10,13,16-pentaazabicyclo[16.3.0]henicosane-2,8,11,14,17-pentaone