ID 5.3.99.9 DE neoxanthin synthase. AN NSY. CA all-trans-violaxanthin = all-trans-neoxanthin. CC -!- The opening of the epoxide ring of violaxanthin generates a chiral CC allene. CC -!- Neoxanthin is a precursor of the plant hormone abscisic acid and the CC last product of carotenoid synthesis in green plants. DR K4C9E2, NSY_SOLLC ; Q9M424, NXS_SOLTU ; //