Linaclotide Aspartic Acid Impurity

Chemical Name: (2S)-2-((3S,6R,9R,15R,20R,23S,26S,29R,32R,37R,40S,45aS)-32-amino-26-(2-carboxyethyl)-40-(carboxymethyl)-23-(4-hydroxybenzyl)-9-(1-hydroxyethyl)-3-methyl-1,4,7,10,13,22,25,28,31,38,41,47-dodecaoxotetracontahydro-1H-37,20-(epiminomethano)-6,29-(methanodithiomethano)pyrrolo[2,1-s][1,2,27,28,5,8,11,14,17,20,23,32,35,38,41]tetrathiaundecaazacyclotritetracontine-15-carboxamido)-3-(4-hydroxyphenyl)propanoic acid

Smile: O=C(O)[C@@H](NC([C@@H](NC(CNC([C@@H](C(O)C)NC([C@@](C(CC1S)S)([H])NC([C@H](C)NC([C@@](CCC2)([H])N2C([C@H](CC(O)=O)NC([C@]3([H])CSSC[C@H](N)C(N[C@]1([H])C(N[C@@H](CCC(O)=O)C(N[C@H]4CC5=CC=C(O)C=C5)=O)=O)=O)=O)=O)=O)=O)=O)=O)=O)CSSC[C@](C(N3)=O)([H])NC4=O)=O)CC6=CC=C(O)C=C6