Formation of Carotenoid Oxygenated Cleavage Products - Carotenoids: Physical, Chemical, and Biological Functions and Properties - page 223

100

( E )-β-Carotene

%

0

0.00 10.00 20.00 30.00 40.00

Apo-carotenals β-Carotene

epoxides

( Z )-β-Carotene
isomers

FIGURE 11.5 Chromatograms at 450 nm of the reaction mixture at 6 h of catalytic oxidation of β-
carotene by dioxygen catalyzed by ruthenium mesitylporphyrin.

O

O

O

O

O

O

O

O

O

O

FIGURE 11.6 Hypothesis of the sequence of events when β-carotene is oxidized by molecular oxygen in the
presence of ruthenium tetramesitylporphyrin. Parts of the chemical formula in dotted line indicate that length
of the carbon chain may vary.

The literature contains other examples of the chemical oxidation of carotenoids that aim to mimic
oxidation processes that potentially occur in vivo . For example, hypochlorous acid, an oxidant pro-
duced by polymorphonuclear leukocytes during inl ammatory processes, was shown to oxidatively
cleave

β -carotene into apocarotenals and shorter chain compounds (Sommerburg et al. 2003).