Linaclotide Impurity 41

((2S,5S,9S,12S,18R,23S,26S,29R,32R,37R,40S,42aS,49R) -32-amino-40- (2-amino-2-oxoethyl) -26- (2-carboxyethyl) -23- (4-hydroxybenzyl) -12- ((R) -1-hydroxyethyl) -49- (mercaptomethyl) -2,5-dimethyl-3,6,13,16,22,27,28,31,38,41,42,48,52-tridecaoxotetracontahydro-21H,36H-21l4-37,21- (epiminoethano) -9,29- (methanothiomethano) pyrrolo[2,1-x][1,15,16,32]tetrathia[2,5,6,11,20,25,26,29,35,36,39,42]dodecaazacyclotetratetracontine-18-carbonyl) -L-tyrosine