(2S)-1-[(3S,6S,9S,12S,15R,18S,21S)-3-(3H-imidazol-4-ylmethyl)-6,15-bis(1H-indol-3-ylmethyl)-21-(3-{[amino(azanylidene)methyl]amino}propyl)-9-(hydroxymethyl)-12-[(4-hydroxyphenyl)methyl]-18-(2-methylpropyl)-1,4,7,10,13,16,19,22-octaoxo-1-[(2S)-5-oxopyrrolidin-2-yl]-2,5,8,11,14,17,20-heptazadocos-22-yl]-N-ethylpyrrolidine-2-carboxamide acetic acid