Figure 1. The terminal step in epinephrine (Epi) biosynthesis catalyzed by phenylethanolamine N-methyltransferase (PNMT, EC 2.1. 1.28), which facilitates the transfer of a methyl group from S-adenosyl-L-methionine (AdoMet) to the primary amine in norepinephrine (NE). S-Adenosyl-L-homocysteine is also formed through this process.