( ( ( Catecholamine hormones ) ( such ( as adrenalin ) ) ) ( ( are ( released ( during ( ( ( frightening or ) stressful ) situations ) ) ) ) . ) )
(ROOT (S (NP (NP (JJ Catecholamine) (NNS hormones)) (PP (JJ such) (IN as) (NP (NN adrenalin)))) (VP (VBP are) (VP (VBN released) (PP (IN during) (NP (ADJP (JJ frightening) (CC or) (JJ stressful)) (NNS situations))))) (. .)))
Catecholamine hormones such as adrenalin are released during frightening or stressful situations.
(ROOT (S (NP (NNP Adrenalin)) (VP (VBZ is) (NP (NP (DT the) (NN hormone)) (VP (VBN produced) (PP (IN in) (NP (JJ high-stress) (NNS situations)))))) (. .)))