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Bioconversion of B‐cryptoxanthin into polar metabolites other than vitamin A
Author(s) -
Mein Jonathan Ryan,
Dolnikowski Gregory,
Russell Robert,
Wang XiangDong
Publication year - 2010
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.24.1_supplement.539.1
Subject(s) - carotenoid , bioconversion , chemistry , vitamin , biochemistry , metabolite , carotene , apolipoprotein b , oxygenase , food science , enzyme , cholesterol , fermentation
Several well‐implemented cohort studies have shown dietary intake or blood levels of β‐cryptoxanthin, but not other pro‐vitamin A carotenoids such as β‐carotene and α‐carotene, to be strongly associated with a reduced risk of lung cancer. This has raised an important question as to whether the potential protective activity of β‐cryptoxanthin, a mono‐hydroxy carotenoid, is due to the intact molecule or formation of unique metabolites. The objective of the present study was to investigate the excentric cleavage activity of mammalian carotene‐9′,10′‐oxygenase (CMO2) towards β‐cryptoxanthin. We found that baculovirus‐generated recombinant ferret CMO2 cleaved β‐cryptoxanthin at both the 9,10 and 9′10′ double bond in a protein‐, time‐ and dose‐dependent manner. In addition to the expected apo‐10′‐carotenal and β‐ionone cleavage products, HPLC and LC‐MS analysis identified the formation of two unique metabolites: 3‐OH‐apo‐10′‐carotenal and 3‐OH‐β‐ionone. Furthermore, in the presence of NAD+, incubation of 3‐OH‐apo‐10′‐carotenal with ferret liver S9 lysate resulted in the dose‐dependent formation of 3‐OH‐apo‐10′‐carotenoic acid. In conclusion, the bioconversion of β‐cryptoxanthin by CMO2 into 3‐OH‐apo‐10′‐carotenoids is significant because 3‐OH‐apo‐carotenoids may represent biologically important metabolites with specific biological activities related to human health. Grant Funding Source : R01CA104932