( ( This reaction ) ( also ( ( ( may not ) ( ( break bonds ) ( to ( the ( chiral center ) ) ) ) ) . ) ) )
(ROOT (S (NP (DT This) (NN reaction)) (ADVP (RB also)) (VP (MD may) (RB not) (VP (VB break) (NP (NNS bonds)) (PP (TO to) (NP (DT the) (JJ chiral) (NN center))))) (. .)))
This reaction also may not break bonds to the chiral center.
(ROOT (S (NP (JJ Catabolic) (NNS reactions)) (VP (VBP involve) (S (VP (VBG breaking) (NP (NNS bonds))))) (. .)))