Tacrolimus 21-Carboxylic Acid Nitroso Impurity

Chemical Name: 2-((2R,3R,5S)-6-((1S,3S,5Z,7R,10S,11R,12S,13E)-7-allyl-10-hydroxy-14-((1R,3R,4R)-4-hydroxy-3-methoxycyclohexyl)-1-methoxy-3,5,11,13-tetramethyl-12-(((S)-1-nitrosopiperidine-2-carbonyl)oxy)-8-oxotetradeca-5,13-dien-1-yl)-2-hydroxy-5-methoxy-3-methyltetrahydro-2H-pyran-2-yl)-2-oxoacetic acid

Smile: O=C(O)C([C@@]1(O)[C@H](C)C[C@H](OC)C([C@@H](OC)C[C@@H](C)C/C(C)=C\[C@@H](CC=C)C(C[C@H](O)[C@@H](C)[C@H](OC([C@H]2N(N=O)CCCC2)=O)/C(C)=C/[C@H]3C[C@@H](OC)[C@H](O)CC3)=O)O1)=O