Absolute Konfiguration von α-Zeacarotin, α-Apo-8-carotinal und α-Apo-8-carotinol
✍ Scribed by Richard Buchecker; Conrad Hans Eugster
- Publisher
- John Wiley and Sons
- Year
- 1973
- Tongue
- German
- Weight
- 236 KB
- Volume
- 56
- Category
- Article
- ISSN
- 0018-019X
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✦ Synopsis
Abstract
α‐Zeacarotene, isolated from corn gluten, has been shown to have the same absolute configuration at C(6) as natural (+)‐α‐carotene. Chiroptical comparison was made with the derived α‐apo‐8‐carotenole. The same chirality has been found with δ‐, ε‐carotene, lutein, semi‐α‐carotenone, zeinoxanthin, crocoxanthin and β,ε‐carotene‐2‐ol. Therefore, biological cyclisation of the acyclic precursor to the α‐ionone ring seems to be stereospecific and is probably different (enantiomeric) to that leading to β‐ionone derivatives.
Cotton effects of carotenoids have for the first time been measured in the visible region. All carotenoids examined with C(6)‐R‐chirality show a positive effect at their longest absorption band.