Goserelin Impurity 40

(11S,14S,17R,20S,23S) -23- ((S) -2- ((S) -3- (1H-imidazol-5-yl) -2- ((S) -5-oxopyrrolidine-2-carboxamido) propanamido) -3- (1H-indol-3-yl) propanamido) -17- (tert-butoxymethyl) -11- (2- ((S) -1- (2-carbamoylhydrazineyl) pyrrolidin-2-yl) -2-oxoacetyl) -2-hydroxy-20- (4-hydroxybenzyl) -6-imino-14-isobutyl-3,13,16,19,22-pentaoxo-4,5,7,12,15,18,21-heptaazatetracosan-24-yl 2-hydroxypropanoate