Xanthophylls capsanthin

Fig. 8.2 Carotene and xanthophyll biosynthetic pathways in Capsicum. Isopentenyl pyrophosphate (IPP) phytoene synthase (PSY) lycopene fi-cyclase (LCYB) lycopene e-cyclase (LCYE) P-carotene hydroxylase (CrtZ-2) zeaxanthin epoxidase (Ze) and capsanthin-capsorubin synthase (CCS)...

Carotene is the major dietary precursor of vitamin A and therefore represents a fundamental component in our diet. The later steps of carotenoid biosynthesis in plants involve the formation of xanthophylls, which are oxygenated derivatives. Among these, capsanthin results from the activity of a bifunctional enzyme, the capsanthin-capsorabin synthase (CCS), that catalyses the conversion of the ubiquitous antheraxanthin and violaxanthin, into capsanthin and capsorubin (Fig. 11.3). 

Several other naturally occurring carotenoids that are not considered significant in the human diet have shown potential as cancer chemopreventive agents. These inclnde neoxanthin, fucoxanthin, phytoflnene, ( -carotene, phytoene, crocetin, capsanthin, peridinin, and astaxanthin. The xanthophyll astaxanthin is a powerful antioxidant and has great potential for reducing human disease processes related to oxidative damage." Therefore, it warrants a more detailed discussion as follows. 

In natural materials, the concentration of C. is usually in the order of 0.02-0.1% of the dry mass. The C. content of the eye ring of the pheasant Narcissus majalis is extremely high, being 16%, or about times that in carrots. An estimated ICf metric tonnes of C. are produced per year by living organisms, the most abundant being fucoxanthin, lutein, violaxan-thin and neoxanthin, followed by p-carotene, zeaxanthin, lycopene, capsanthin and bixin. More than 90 % of the C. in a plant is found in the leaves, usually as a mixture of 20 0% carotenes (containing more than 70 % p-carotene) and 60-80 % xanthophylls like lutein, violaxanthin, cryptoxanthin and zeaxanthin. 

Sander et al. [828] separated seven xanthophylls (e.g., lutein, zeaxanthin, capsanthin, echinenone) and seven carotenoids (e.g., a-, P-, and y-carotene, lycopene, 15-cw- -carotene) on a C30 column (X = 450nm) using a 90-min 81/15/4 -> 6/90/A methanol/MlBE/water gradient. Excellent resolution between all 14 components and peak shapes were obtained. The authors note that a nonaqueous methanol/MrBE gradient resolves all compounds except for the fi-cryptoxanthin/echinenone pair. As noted above, the addition of 4% water resolves this pair and retains separation of all other compounds as well. 

Two xanthophylls, capsorubin and capsanthin, were extracted from red peppers and analyzed on a Cjg column (A = 450nm) using an 80/10/10 acetonitrile/... 

As shown in Table 1 Titavit treatment stimultated to a high extent carotenoid formation, specially p-carotene and red coloured xanthophylls (capsorubin and capsanthin). Esterification of capsanthin with fatty acids increased 1.4 times as a function of Titavit treatment. This was accompanied by structural change on the chromoplast. The fatty bodies disappeared and the fibriles became much thicker in chromoplast from Titavit-treated fruits. 

---