2-((S)-2-((S)-1-((4R,7S,10S,13S,16S)-7-(2-amino-2-oxoethyl)-13-benzyl-16-(4-hydroxybenzyl)-10-isobutyl-6,9,12,15,18-pentaoxo-1,2-dithia-5,8,11,14,17-pentaazacycloicosane-4-carbonyl)pyrrolidine-2-carboxamido)-6-(2-aminobenzamido)hexanamido)acetic acid