Lutein

• Xanthophyll
• (3R, 3'R, 6'R ) - β, ε -carotene -3, 3' -diol
• 4 - [ 18 - (4- hydroxy-2 ,6,6 -trimethyl- cyclohex -2-enyl ) -3,7,12,16 -tetramethyl- octadeca -1, 3,5,7,9,11,13 ,15,17 - nonaenyl ] - 3,5,5 -trimethyl -cyclohex -3 -enol (IUPAC)
• E 161b

Orange -yellow solid

Fixed

190 ° C.

Insoluble in water

Template: Infobox chemical / molecular formula search available

Lutein ( " stained with Reseda " from the Latin luteus, " orange yellow ") is a yellow-orange, and the next xanthophyll β -carotene most common carotenoid. Lutein is approved as E 161b in the EU as a food dye.

Occurrence

Lutein is a naturally widespread xanthophyll and is always accompanied by zeaxanthin.

High levels are in dark leafy vegetables (eg kale to 0.25 mg / g fresh weight, spinach to 0.12 mg / g fresh weight) have been found. Tagetes petals, with contents up to 8.5 mg / g fresh weight and are used for industrial production of lutein. Lutein occurs in animal organisms, for example, as a yellow colorant in the egg yolk. In the macula of the eye, lutein and zeaxanthin are the only carotenoids before.

Production and representation

The biosynthesis of lutein from α -carotene occurs by hydroxylation of both Iononringe by specific hydroxylases. This biosynthesis as well as that of α -carotene occurs only in plants.

Industrially it is recovered by extraction luteinhaltiger parts of plants, especially from marigold petals.

Properties

Lutein forms orange - yellow, oxidation and heat-sensitive crystals.

Use

Lutein is used as a food dye ( E161b ) as well as a feed additive for poultry in particular to yellow yolk of use.

It is also used as an active ingredient in medicaments for the treatment of macular degeneration (AMD ); the mode of action is unclear. Recent research has shown that the administration of lutein also prevent macular degeneration in old age and can mitigate. To test these findings, in 2008 the AREDS II study was initiated.

In 2010, a study from the University of Wisconsin -Madison with 1800 participants that by the gift of lutein and vitamin C, the risk of cataracts in women can be reduced.

Risks of supplementation

The VITAL study

The VITAL study ( " Vitamins and Lifestyle ") was a cohort study, which was conducted in 2000-2002 with over 77,000 participants in the U.S. state of Washington. She had to reveal the interrelationships of the intake of vitamins and other nutritional supplements with a possible increased risk of cancer. As one of the results, it was found that a constant for several years taking lutein is associated with a higher risk of lung cancer in women. Despite the large number of participants, the number of Luteinbenutzer was but may be too small to be statistically significant.

Biological Significance

Lutein is part of the light -harvesting complexes in chloroplasts. There, it increases the energy yield and exhibits a protective effect. It serves as a further Lockfarbe in petals and fruit. In humans, lutein plays ( in combination with zeaxanthin ) an essential role in vision.