Altering the extent of the conjugated double-bond system as a result of the epoxidation and de-epoxidation reactions. Under high light, diadinoxanthin converts to diatoxanthin reverting to diadinoxanthin under dim light ordarkness. (Ref.632)

Ref.687 : M. Lohr and C. Wilhelm, Proc. Natl. Acad. Sci. USA, Vol. 96, pp. 8784–8789, July 1999, Plant Biology "Algae displaying the diadinoxanthin cycle also possess the violaxanthin cycle"

Ref.632 : Miriam Zigman, Zvy Dubinsky and David Iluz, Applied Photosynthesis 2012, ISBN: 978-953-51-0061-4, "The Xanthophyll Cycle in Aquatic Phototrophs and Its Role in the Mitigation of Photoinhibition and Photodynamic Damage "