Felypressin Impurity C

(2S,2’S)-1,1′-((4R,7S,10S,13S,16S,19R,24R,27S,30S,33S,36S,39R)-19,39-diamino-7,27-bis(2-amino-2-oxoethyl)-10,30-bis(3-amino-3-oxopropyl)-13,16,33,36-tetrabenzyl-6,9,12,15,18,26,29,32,35,38-decaoxo-1,2,21,22-tetrathia-5,8,11,14,17,25,28,31,34,37-decaazacyclotetracontane-4,24-dicarbonyl)bis(N-((S)-6-amino-1-((2-amino-2-oxoethyl)amino)-1-oxohexan-2-yl)pyrrolidine-2-carboxamide)