FTISADTSK-13C6,15N2 TFA is 13C- and 15N-labeled FTISADTSK . FTISADTSK is an endogenous stable signature peptide from Trastuzumab monitored by selected reaction monitoring (SRM).
Stable heavy isotopes of drogen, carbon, and other elements have been incorporated into drug molecules, largely as tracers for quantitation during the drug development process. Deuteration has gained attention because of its potential to affect the pharmacokinetic and metabolic profiles of drugs[1].
References:
[1]. Russak EM, et al. Impact of Deuterium Substitution on the Pharmacokinetics of Pharmaceuticals. Ann Pharmacother. 2019 Feb;53(2):211-220.
[2]. Bults P, et al. LC-MS/MS-Based Monitoring of In Vivo Protein Biotransformation: Quantitative Determination of Trastuzumab and Its Deamidation Products in Human Plasma. Anal Chem. 2016;88(3):1871-1877.