Plant tyrosine decarboxylase can be strongly inhibited by L-α-aminooxy-β-phenylpropionate.

Tyrosine decarboxylase (EC 4.1.1.25) from Syringa vulgaris L. cell cultures and from Hordeum vulgare L. seedlings is strongly inhibited by the phenylalanine analogue, L-α-aminooxy-β-phenylpropionate. L-α-Aminooxy-β-phenylpropionate is therefore not specific in its inhibitory action against phenylalanine ammonia-lyase (EC 4.3.1.5). Hordeum tyrosine decarboxylase is also very sensitive to α-fluoromethyl(3,4-dihydroxyphenyl)alanine, but preparations from Nicotiana tabacum L. and Sanguinaria canadensis L. are largely unaffected by either type of inhibitor.