2-{[(2S)-2-({[(2S)-1-{[(4R,7S,10S,13S,16R)-13-[(2S)-but-2-yl]-7-(carbamoylmethyl)-16-[(4-ethoxyphenyl)methyl]-10-[(1R)-1-hydroxyethyl]-6,9,12,15,18-pentaoxo-1,2-dithia-5,8,11,14,17-pentazacycloicosan-4-yl]carbonyl}pyrrolidin-2-yl]carbonyl}amino)-5-amino-1-oxopentyl]amino}acetamide