A Chloroacetamidine‐Based Inactivator of Protein Arginine Methyltransferase 1: Design, Synthesis, and In Vitro and In Vivo Evaluation

Protein arginine methyltransferases (PRMTs) catalyze the post-translational methylation of arginine residues. PRMT1 is the predominant mammalian isozyme and is responsible for generating the majority of the asymmetrically dimethylated arginine found in vivo. Herein, we describe the most potent PRMT1 inhibitor, C21, described to date.