Enzymatic formation of apo-carotenoids from the xanthophyll carotenoids lutein, zeaxanthin and β-cryptoxanthin by ferret carotene-9′,10′-monooxygenase

► Vertebrate CMO2 enzymatically cleaves xanthophylls at the 9,10 and 9′,10′ double bond. ► Lutein and zeaxanthin are preferentially cleaved over β-cryptoxanthin. ► 3-OH-β-apo-10′-carotenal is oxidized to 3-OH-β-apo-10′-carotenoic acid.