(2S)?-1-?[2-?[(2R,?3R,?6S)?-?6-?[(2S,?3E,?5E,?7E,?9S,?11R)?-?2,?13-?Dimethoxy-?3,?9,?11-?trimethyl-?12-?oxo-?3,?5,?7-?tridecatrien-?1-?yl]?tetrahydro-?2-?hydroxy-?3-?methyl-?2H-?pyran-?2-?yl]?-?2-?oxoacetyl]?-?2-?piperidinecarboxylic Acid-d3 is labelled (2S)?-1-?[2-?[(2R,?3R,?6S)?-?6-?[(2S,?3E,?5E,?7E,?9S,?11R)?-?2,?13-?Dimethoxy-?3,?9,?11-?trimethyl-?12-?oxo-?3,?5,?7-?tridecatrien-?1-?yl]?tetrahydro-?2-?hydroxy-?3-?methyl-?2H-?pyran-?2-?yl]?-?2-?oxoacetyl]?-?2-?piperidinecarboxylic Acid (D461585) which is an impurity of Sirolimus (R124000) which is an immunosuppressant drug used to prevent rejection in organ transpl