A phenethylamine alkaloid that is 4-(2-aminoethyl)phenol substituted by a hydroxy group at position 1 and a methyl group at the amino nitrogen. ChEBI: Synephrine is a phenethylamine alkaloid that is 4-(2-aminoethyl)phenol substituted by a hydroxy group at position 1 and a methyl group at the amino nitrogen. It has a role as a plant metabolite and an alpha-adrenergic agonist. It is a phenethylamine alkaloid, a member of phenols and a member of ethanolamines. It is a conjugate base of a synephrinium.