Crossword clues for lutein
The Collaborative International Dictionary
Lutein \Lu"te*in\, n. [From corpus luteum.] (Physiol. Chem.) A substance of a strongly marked yellow color, extracted from the yolk of eggs, and from the tissue of the corpus luteum.
Wiktionary
n. (context organic compound English) A yellow carotenoid pigment, widely distributed in both plants and animals.
WordNet
n. yellow carotenoid pigments in plants and animal fats and egg yolks [syn: xanthophyll, xanthophyl]
Wikipedia
Lutein ( or ; from Latin luteus meaning "yellow") is a xanthophyll and one of 600 known naturally occurring carotenoids. Lutein is synthesized only by plants and like other xanthophylls is found in high quantities in green leafy vegetables such as spinach, kale and yellow carrots. In green plants, xanthophylls act to modulate light energy and serve as non-photochemical quenching agents to deal with triplet chlorophyll (an excited form of chlorophyll), which is overproduced at very high light levels, during photosynthesis. See xanthophyll cycle for this topic.
Lutein is obtained by animals directly or indirectly, from plants. Lutein is apparently employed by animals as an antioxidant and for blue light absorption. Lutein is found in egg yolks and animal fats. In addition to coloring yolks, lutein causes the yellow color of chicken skin and fat, and is used in chicken feed for this purpose. The human retina accumulates lutein and zeaxanthin. The latter predominates at the macula lutea while lutein predominates elsewhere in the retina. There, it may serve as a photoprotectant for the retina from the damaging effects of free radicals produced by blue light. Lutein is isomeric with zeaxanthin, differing only in the placement of one double bond.
The principal natural stereoisomer of lutein is (3R,3′R,6′R)-beta,epsilon-carotene-3,3′-diol. Lutein is a lipophilic molecule and is generally insoluble in water. The presence of the long chromophore of conjugated double bonds ( polyene chain) provides the distinctive light-absorbing properties. The polyene chain is susceptible to oxidative degradation by light or heat and is chemically unstable in acids.
Lutein is present in plants as fatty-acid esters, with one or two fatty acids bound to the two hydroxyl-groups. For this reason, saponification (de-esterfication) of lutein esters to yield free lutein may yield lutein in any ratio from 1:1 to 1:2 molar ratio with the saponifying fatty acid.
Usage examples of "lutein".
Her curly brown hair shined with megadoses of vitamin A, the tawny bare arms glowed from adequate lutein consumption, her eyes sparkled with high-concentrate beta-carotene.
A half-cup of cooked kale, collard greens, or spinach delivers at least 13 milligrams of the carotenoid called lutein, which is shown to help prevent narrowing or hardening of the arteries.
Amount of fat in the diet affects bioavailability of lutein esters but not of alpha-carotene, beta-carotene, and vitamin E in humans.
Research shows that more protective benefits come from the lutein found in spinach than the beta-carotene found in carrots.
Her curly brown hair shined with megadoses of vitamin A, the tawny bare arms glowed from adequate lutein consumption, her eyes sparkled with high-concentrate beta-carotene.