Lutein AREDS

Monarch epidermis. Peaks seen at 8.7, 10, and 82min are 3-hydroxy-10 -apo-P-carotenal, lutein, zeaxanthin, and P-carotene, respectively. The peak seen eluting at 22 min is the internal standard, monopropyl lutein ether, (b) The chromatogram obtained from an extract of the leaves of the milkweed plant. Peaks eluting prior to lutein are xanthophylls and epoxy xanthophylls, identified components include lutein, zeaxanthin, P-carotene, and its crT-isomer, eluting at 10, 11, 41, 77, and 79min, respectively. 

Purified alfalfa gives a clean, bright lemon yellow shade. Lutein is more stable to oxidation than the other carotenoids. It is also resistant to the action of sulfur dioxide. Lutein is oil soluble and is most effective dissolved in oil. Aqueous dispersible preparations based on lutein are available. 

The metabolism and pharmacokinetics of the carotenoids are not well understood, and their bioavailabUity is associated with much interindividual and intraindividual variation (281). p-Carotene, a-carotene, cryptoxanthin, lycopene, and lutein are the major carotenoids in human serum, and lycopene and p-carotene are the major carotenoids in other human tissues (282). Small amounts of zeax-anthin, phytofluene, and phytoene are also found in various organs. Various carotenoids tend to be present in similar ratios in human plasma and tissues (282, 283). The carotenoids are safe and even long-term intake of 180 mg of p-carotene per day did not lead to hypervitaminosis. When large amounts of carotenoids are stored in the adipose and other lipid-rich tissues, they may cause reversible yellowing of the... 

There is much current debate about the relevance of such carotenoid repair processes to hydrocarbon carotenoids such as 8-carotene and lycopene in vivo where the parent carotenoid is unhkely to encounter the polar ascorbic acid. However, the cation radical, with a positive charge, maybe sufficiently polar and long-lived for such interactions to be possible. For the carotenoids found in the macula, where an efficient anti-oxidant process is crucial, the hydroxy carotenoids zeaxanthin, meso zeaxanthin and lutein are likely to be in a membrane orientation such that the corresponding cation radicals are efficiently repaired by the vitamin C (cf. vitamin E, below). 

Three such peroxyl radicals (9-phenanthrylperoxyl, 1-naphthylperoxyl and 2-naphthylperoxyl) have been studied in methanol and the rate constants obtained for their electron transfer reaction with the carotenoids zeaxanthin and lutein are given in Table 2. 

The triglyceride composition is summarized in Tables 3.142 and 3.143. Unsaponifiable components occur at levels of 0.2-1% of the oil and include hydrocarbons, aliphatic alcohols, triterpene alcohols (Table 3.147), sterols (Tables 3.145, 3.146 and 3.50) and tocopherols (Table 3.51). jS-Carotene and lutein are the major pigments, their level decreasing in the oil as the seed matures. Changes in the major lipid classes during maturation have been studied (Pattee et aL,1969 Sanders, 1980). Oleic acid increases as maturation progresses. 

Oxygenated derivatives of carotenoids also are common and widely distributed. These colored substances are known collectively as xanthophylls. The formation of xanthophylls involves an aerobic mechanism. p-Carotene is converted oxidatively to lutein (2), zeaxanthin [(3/ , 37 )-3,p-carotene-3,3 -diol] (15), and, finally, to violaxanthin (3) (Fig. 26.10) (Britton, 1993). Labeling studies have shown that hydroxyla-tions such as those involved in the conversion of zeaxanthin and lutein are formed by the direct replacement of the hydrogen by OH (Britton, 1993). 

Despite having no provitamin A function, carotenoids such as lycopene and lutein are still biologically active. High serum lycopene... 

Bechuanine and merenderine are identical in all respects, and correspond to the S -( + )-enantiomer of the known homoaporphine (—)-floramultine. The reduced homoproaporphine ( + )-yolantamine (jolantamine, jolanthamine) is diastereomeric with (-h)-bulbocodine. ( + )-Kesselringine and (-h)-luteine are diastereomers possessing identical stereochemistry at C-6a. 

Apples are a good source of vitamin C and E. Moreover they contain lutein, folic acid, potassium and magnesium. Vitamin C and E together with lutein are important antioxidants and may contribute to protective health effects against chronic diseasesFolic acid, as well as potassium and magnesium, has been associated with a reduced risk of CVD. ... 

Lycopene accounts for >85% of the total tomato carotenoids in red-ripe fruits thus causing its characteristic colour (Lenucci et al. 2006 and references therein). This open-chain hydrocarbon with 11 conjugated and two isolated double bonds has the highest degree of unsaturation of all carotenoids. Its concentration varies from 30 to 200mg/kg fresh wt (Topal et al. 2006). Phytoene, p-carotene, and lutein are further quantitatively remarkable constituents (Bums et al. 2003). 

Other significant components. Carotenoid pigments vary by variety in tomato seed oil. Red varieties contain lycopene, P-carotene, and lutein while zeta-carotene, P-carotene and lutein are the major pigment of yellow cultivars. Protein comprised about 33% of the seed and crude fiber about 25%. 

---