d-3,4-dihydroxyphenylalanine , d-threo-3,4-dihydroxyphenylserine and pyrocatechol competitively inhibited aromatic l-amino acid decarboxylase , whereas no inhibition occurred with l-norepinephrine , l-epinephrine , dopamine or some other amino acids without catechol side chains .
C0028351
norepinephrine
C0014563
epinephrine