( L ( - ( ( Tyrosine ( is ( natural ( amino acid ) ) ) ) . ) ) )
(ROOT (FRAG (NP (NNP L)) (: -) (S (NP (NNP Tyrosine)) (VP (VBZ is) (NP (JJ natural) (JJ amino) (NN acid)))) (. .)))
L- Tyrosine is natural amino acid.
(ROOT (S (NP (NNS Catecholamines)) (VP (VBP are) (NP (NP (DT a) (NN class)) (PP (IN of) (NP (JJ amine) (NNS hormones))) (SBAR (WHNP (WHNP (DT that)) (NP (WRB when) (JJ synthesised))) (S (VP (VBP form) (NP (DT the) (JJ amino) (NN acid) (NN tyrosine))))))) (. .)))