Lanreotide Impurity 19

(4R,7R,10R,13R,16S,19R,24R,27R,30R,33R,36S,39R) -13,33-bis ((1H-indol-3-yl) methyl) -19,39-bis ((R) -2-amino-3- (naphthalen-2-yl) propanamido) -N4, N24-bis ((3S) -1-amino-3-hydroxy-1-oxobutan-2-yl) -10,30-bis (4-aminobutyl) -16,36-bis (4-hydroxybenzyl) -7,27-diisopropyl-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-dicarboxamide