2-[(3S)-3-[[(2S)-1-ethoxy-1-oxo-4-phenylbutan-2-yl]-nitrosoamino]-2-oxo-4,5-dihydro-3H-1-benzazepin-1-yl]acetic acid;(2-((S)-3-(((S)-1-ethoxy-1-oxo-4-phenylbutan-2-yl)(nitroso)amino)-2-oxo-2,3,4,5-tetrahydro-1H-benzo[b]azepin-1-yl)acetic acid);