Lutein is a fat-soluble xanthophyll carotenoid.

The name "lutein" comes from the Latin "luteus" meaning "yellow". This refers to the yellow color of lutein.

Synthesis of lutein.

• In plants. Lutein is a xanthophyll pigment that is synthesized in plants. It's an important component of chloroplasts and plays a key role in photosynthesis.
• Through diet. Humans cannot synthesize lutein and so must obtain it through diet. Lutein is found in many leafy green vegetables, like spinach and lettuce, as well as in other foods like eggs.

Natural synthesis of lutein.

• Production of precursors. In the chloroplasts of plants, fatty acid molecules are converted into geranylgeranyl diphosphate (GGPP), an important precursor.
• Formation of carotenoids. The GGPP is converted into phytoene, which is then transformed into lycopene through a series of enzyme reactions.
• Synthesis of lutein. The lycopene is converted into alpha-carotene, which is then transformed into lutein through the action of several enzymes.

It appears in the form of an orange powder.

What it is used for and where

Natural substance found in vegetables with green leaves, egg yolk.

Medical

It is an antioxidant that protects the human eye by filtering out ultraviolet rays and protecting it from degenerative ageing diseases.

It is found in spinach, vegetables, fruit and eggs.

It has antioxidant, anti-cancer, anti-inflammatory properties particularly against retinopathy of prematurity, age-related macular degeneration, cataracts, myopia (1)

Food

Lutein is generally obtained from the plant Tagetes erecta L., which belongs to the Asteraceae family and contains at least 80% carotenoids.

 Lutein is an ingredient included in the list of European food additives as a colour with the number E161b. The Panel on Food Additives noted the lack of reproductive toxicity and chronic toxicity/carcinogenicity studies and therefore, in the uncertainty, applied an ADI (Acceptable Daily Intake) of 1 mg/kg body weight/day (2).

Lutein studies

• Molecular Formula: C₄₀H₅₆O₂
• Molecular Weight: 568.886 g/mol
• CAS: 127-40-2
• EC Number: 204-840-0
• UNII: X72A60C9MT
• PubChem Substance ID 329748359
• MDL number: MFCD08435941
• Beilstein Registry Number: 2068547

Synonyms:

• Luteine
• Bo-Xan
• beta,epsilon-Carotene-3,3'-diol, (3R,3'R,6'R)-
• (3R,3'R,6'R)-beta,epsilon-carotene-3,3'-diol
• ε-carotene-3,3′-diol
• ε-carotene
• α-Carotene-3,3′-diol, β
• all-trans-Xanthophyll
• Xanthophyll
• beta,epsilon-Carotene-3,3'-diol
• NSC 59193

References_____________________________________________________________________

(1) Li LH, Lee JC, Leung HH, Lam WC, Fu Z, Lo ACY. Lutein Supplementation for Eye Diseases. Nutrients. 2020 Jun 9;12(6):1721. doi: 10.3390/nu12061721.

(2) EFSA Scientific Opinion on the re-evaluation of lutein (E 161b) as a food additive  EFSA-Q-2008-787  doi  10.2903/j.efsa.2010.1678