A 3-hydroxy β-end group in xanthophylls is preferentially oxidized to a 3-oxo ε-end group in mammals

摘要: We previously found that mice fed lutein accumulated its oxidative metabolites (3′-hydroxy-e,e-caroten-3-one and e,e-carotene-3,3′-dione) as major carotenoids, suggesting mammals can convert xanthophylls to keto-carotenoids by the oxidation of hydroxyl groups. Here we elucidated metabolic activities mouse liver for several xanthophylls. When was incubated with postmitochondrial fraction in presence NAD+, (3′R,6′R)-3′-hydroxy-β,e-caroten-3-one (6RS,3′R,6′R)-3′-hydroxy-e,e-caroten-3-one were produced products. The former only at early stage assumed be an intermediate, followed isomerization latter. configuration C3′ C6′ e-end group retained two These results indicate 3-hydroxy β-end preferentially oxidized a 3-oxo via group. Other such β-cryptoxanthin zeaxanthin, which have group, also same manner lutein. keto-carotenoids, derived from dietary xanthophylls, confirmed present plasma normal human subjects, β,e-caroten-3′-one significantly increased ingestion β-cryptoxanthin. Thus, humans well activity