Catalyzes the transmethylation of nonepinephrine (noradrenaline) to form epinephrine (adrenaline), using S-adenosyl-L-methionine as the methyl donor (By similarity). Other substrates include phenylethanolamine, octopamine and normetanephrine (PubMed:13863458, PubMed:683413). phenylethanolamine + S-adenosyl-L-methionine = H(+) + N-methylphenylethanolamine + S-adenosyl-L-homocysteine (R)-noradrenaline + S-adenosyl-L-methionine = (R)-adrenaline + H(+) + S-adenosyl-L-homocysteine (R)-normetanephrine + S-adenosyl-L-methionine = H(+) + N-methyl-(R)-normetanephrine + S-adenosyl-L-homocysteine (R)-octopamine + S-adenosyl-L-methionine = (R)-synephrine + H(+) + S-adenosyl-L-homocysteine Inhibited by 3-methyl-l,2,3,4-tetrahydro[1]benzothieno[3,2-c]pyridine hydrochloride. Optimum pH is 7.9 in phosphate buffer. Catecholamine biosynthesis; (R)-adrenaline biosynthesis; (R)-adrenaline from (R)-noradrenaline: step 1/1. Expressed in the adrenal medulla and brain. Belongs to the class I-like SAM-binding methyltransferase superfamily. NNMT/PNMT/TEMT family.