CP21 is an iron chelator that binds to iron in a 3:1 (ligand:iron) ratio. It is active against P. falciparum when used at concentrations of 10 and 100 µM. CP21 inhibits production of prostaglandin I2 induced by epinephrine, arachidonic acid, or A23187 in isolated rat aortic rings with IC50 values of 1.3, 1.3, and 1.4 mM, respectively. It inhibits glutamate-induced oxytosis, as well as decreases iodoacetic acid-induced cytotoxicity in an in vitro model of ischemia, in HT22 mouse hippocampal cells (EC50s = 13 and 9.5 µM, respectively). CP21 (200 mg kg) increases the excretion of iron, but not copper, zinc, calcium, or magnesium, in rabbits.
Erlotinib-13C6 (CP-358774-13C6) is a 13C-labeled Erlotinib. Erlotinib is a directly acting EGFR tyrosine kinase inhibitor, with an IC50 of 2 nM for human EGFR[1]. Erlotinib reduces EGFR autophosphorylation in intact tumor cells with an IC50 of 20 nM. Erlotinib is used for the treatment of non-small cell lung cancer[1].Stable heavy isotopes of hydrogen, carbon, and other elements have been incorporated into drug molecules, largely as tracers for quantitation during the drug development process[2]. [1]. Moyer JD, et al. Induction of apoptosis and cell cycle arrest by CP-358,774, an inhibitor of epidermal growth factor receptor tyrosine kinase. Cancer Res. 1997, 57(21), 4838-4848.[2]. Russak EM, et al. Impact of Deuterium Substitution on the Pharmacokinetics of Pharmaceuticals. Ann Pharmacother. 2019;53(2):211-216.