THE PRODIGY-5 MICRONUTRIENT FORMULA FOR GENERAL HEALTH: Vitamin A • Vitamin C • Vitamin D • Vitamin E • Vitamin K • Vitamin B6 • Vitamin B12 • Folate • B1 (Thiamin) • B2 (Riboflavin) • B3 (Niacin) 

MICRONUTRIENT FORMULA FOR EYE HEALTH: Lutein • Zeaxanthin • Copper • Zinc 

 

Zeaxanthin

From Wikipedia, the free encyclopedia
 
 
Zeaxanthin
Structural formula of zeaxanthin
Space-filling model of the zeaxanthin molecule
Names
IUPAC name
4-[18-(4-hydroxy-2,6,6-trimethyl-1-cyclohexenyl)-3,7,12,16-tetramethyl-octadeca-1,3,5,7,9,11,13,15,17-nonaenyl]-3,5,5-trimethyl-cyclohex-3-en-1-ol
Other names
β,β-carotene-3,3'-diol
Identifiers
144-68-3 Yes
3D model (Jmol) Interactive image
ChEBI CHEBI:27547 Yes
ChemSpider 4444421 Yes
ECHA InfoCard 100.005.125
E number E161h (colours)
PubChem 5280899
UNII CV0IB81ORO Yes
Properties
C40H56O2
Molar mass 568.88 g/mol
Appearance orange-red
Melting point 215.5 °C (419.9 °F; 488.6 K)
insol.
Related compounds
Related compounds
lutein
xanthophyll
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Yes verify (what is Yes ?)
Infobox references
   

Zeaxanthin is one of the most common carotenoid alcohols found in nature. It is important in the xanthophyll cycle. Synthesized in plants and some micro-organisms, it is the pigment that gives paprika (made from bell peppers), cornsaffronwolfberries, and many other plants and microbes their characteristic color.[1][2]

The name (pronounced zee-uh-zan'-thin) is derived from Zea mays (common yellow maize corn, in which zeaxanthin provides the primary yellow pigment), plus xanthos, the Greek word for "yellow" (see xanthophyll).

Xanthophylls such as zeaxanthin are found in highest quantity in the leaves of most green plants, where they act to modulate light energy and perhaps serve as a non-photochemical quenchingagent to deal with triplet chlorophyll (an excited form of chlorophyll) which is overproduced at high light levels during photosynthesis.

Animals derive zeaxanthin from a plant diet.[2] Zeaxanthin is one of the two primary xanthophyllcarotenoids contained within the retina of the eye. Within the central macula, zeaxanthin is the dominant component, whereas in the peripheral retina, lutein predominates.

Zeaxanthin supplements are typically taken on the supposition of supporting eye health. Although there are no reported side effects from taking zeaxanthin supplements, this possible benefit remains scientifically unproven, despite extensive ongoing research to define dietary or supplemental effects of zeaxanthin and lutein.[3][4][5]

As a food additive, zeaxanthin is a food dye with E number E161h.

Isomers and macular uptake

Lutein and zeaxanthin have identical chemical formulas and are isomers, but they are not stereoisomers. The only difference between them is in the location of the double bond in one of the end rings. This difference gives lutein three chiral centers whereas zeaxanthin has two. Because of symmetry, the (3R,3'S) and (3S,3'R) stereoisomers of zeaxanthin are identical. Therefore, zeaxanthin has only three stereoisomeric forms. The (3R,3'S) stereoisomer is called meso-zeaxanthin.

The principal natural form of zeaxanthin is (3R,3'R)-zeaxanthin. The macula mainly contains the (3R,3'R)- and meso-zeaxanthin forms, but it also contains much smaller amounts of the third (3S,3'S) form.[6] Evidence exists that a specific zeaxanthin-binding protein recruits circulating zeaxanthin and lutein for uptake within the macula.[7]

Due to the commercial value of carotenoids, their biosynthesis has been studied extensively in both natural products and non-natural (heterologous) systems such as the bacteria Escherichia coli and yeast Saccharomyces cerevisiae. Zeaxanthin biosynthesis proceeds from beta-carotene via the action of a single protein, known as a beta-carotene hydroxylase, that is able to add a hydroxyl group (-OH) to carbon 3 and 3' of the beta-carotene molecule. Zeaxanthin biosynthesis therefore proceeds from beta-carotene to zeaxanthin (a di-hydroxylated product) via beta-cryptoxanthin (the mono hydroxylated intermediate). Although functionally identical, several distinct beta-carotene hydroxylase proteins are known. Due to the nature of zeaxanthin, relative to astaxanthin (a carotenoid of significant commercial value) beta-carotene hydroxylase proteins have been studied extensively.[8]

Relationship with diseases of the eye

Several observational studies have provided preliminary evidence for high dietary intake of foods including zeaxanthin with lower incidence of age-related macular degeneration (AMD), most notably the Age-Related Eye Disease Study.[9][10]

In general, however, there remains insufficient evidence to assess the effectiveness of dietary or supplemental zeaxanthin or lutein in treatment or prevention of AMD, or the formation or progression of cataracts.[2][9][11] Any benefit is more likely to be apparent in subpopulations of individuals exposed to high oxidative stress, such as heavy smokers, alcoholics or those with poor nutrition.[12]

In 2005, the US Food and Drug Administration rejected a Qualified Health Claims application by Xangold, citing insufficient evidence supporting the use of a zeaxanthin-containing supplement in prevention of AMD.[13]

Natural occurrence

Zeaxanthin is the pigment that gives paprika (made from bell peppers), cornsaffronwolfberries, and many other plants their characteristic color.[2]Spirulina is also a rich source and can serve as a dietary supplement.[14] Zeaxanthin breaks down to form picrocrocin and safranal, which are responsible for the taste and aroma of saffron.[15]

Foods containing the highest amounts of lutein and zeaxanthin are dark green leaf vegetables, such as kalespinachturnip greenscollard greensromaine lettucewatercressSwiss chard and mustard greens.[2][16]

Safety

An acceptable daily intake level for zeaxanthin was proposed as 0.75 mg/kg  of body weight/day, or 53 mg/day for a 70 kg adult.[17] In humans, an intake of 20 mg/day for up to six months had no adverse effects.[17]

References

  1. Jump up^  Encyclopedia.com. "Carotenoids". Retrieved 6 May 2012.
  2. Jump up to:a b c d e "Lutein + Zeaxanthin Content of Selected Foods". Linus Pauling Institute, Oregon State University, Corvallis. 2014. Retrieved 20 May 2014.
  3. Jump up^  Age-Related Eye Disease Study 2 Research Group (2013). "Lutein + zeaxanthin and omega-3 fatty acids for age-related macular degeneration: The Age-Related Eye Disease Study 2 (AREDS2) randomized clinical trial". JAMA309 (19): 2005–15. doi:10.1001/jama.2013.4997PMID 23644932.
  4. Jump up^  Pinazo-Durán, M. D.; Gómez-Ulla, F; Arias, L; Araiz, J; Casaroli-Marano, R; Gallego-Pinazo, R; García-Medina, J. J.; López-Gálvez, M. I.; Manzanas, L; Salas, A; Zapata, M; Diaz-Llopis, M; García-Layana, A (2014). "Do Nutritional Supplements Have a Role in Age Macular Degeneration Prevention?"Journal of Ophthalmology2014: 901686. doi:10.1155/2014/901686PMC 3941929Freely accessiblePMID 24672708.
  5. Jump up^  Koo, E; Neuringer, M; Sangiovanni, J. P. (2014). "Macular xanthophylls, lipoprotein-related genes, and age-related macular degeneration". American Journal of Clinical Nutrition100 (Supplement 1): 336S–346S. doi:10.3945/ajcn.113.071563PMID 24829491.
  6. Jump up^  Nolan, J. M.; Meagher, K; Kashani, S; Beatty, S (2013). "What is meso-zeaxanthin, and where does it come from?"Eye27 (8): 899–905. doi:10.1038/eye.2013.98PMC 3740325Freely accessiblePMID 23703634.
  7. Jump up^  Li, B; Vachali, P; Bernstein, P. S. (2010). "Human ocular carotenoid-binding proteins"Photochemical & Photobiological Sciences9 (11): 1418–25. doi:10.1039/c0pp00126kPMC 3938892Freely accessiblePMID 20820671.
  8. Jump up^  Scaife, Mark A.; Ma, Cynthia A.; Ninlayarn, Thanyanun; Wright, Phillip C.; Armenta, Roberto E. (22 May 2012). "Comparative Analysis of β-Carotene Hydroxylase Genes for Astaxanthin Biosynthesis". Journal of Natural Products75 (6): 120522090507004. doi:10.1021/np300136tPMID 22616944.
  9. Jump up to:a b Krishnadev N, Meleth AD, Chew EY (May 2010). "Nutritional supplements for age-related macular degeneration"Current Opinion in Ophthalmology21 (3): 184–9. doi:10.1097/ICU.0b013e32833866eePMC 2909501Freely accessiblePMID 20216418.
  10. Jump up^  SanGiovanni JP, Chew EY, Clemons TE, et al. (September 2007). "The relationship of dietary carotenoid and vitamin A, E, and C intake with age-related macular degeneration in a case-control study: AREDS Report No. 22". Archives of Ophthalmology125 (9): 1225–1232. doi:10.1001/archopht.125.9.1225PMID 17846363.
  11. Jump up^  Chong EW, Wong TY, Kreis AJ, Simpson JA, Guymer RH (October 2007). "Dietary antioxidants and primary prevention of age related macular degeneration: systematic review and meta-analysis"BMJ (Clinical Research Ed.)335 (7623): 755. doi:10.1136/bmj.39350.500428.47PMC 2018774Freely accessiblePMID 17923720.
  12. Jump up^  Fernandez MM, Afshari NA (January 2008). "Nutrition and the prevention of cataracts". Current Opinion in Ophthalmology19 (1): 66–70. doi:10.1097/ICU.0b013e3282f2d7b6PMID 18090901.
  13. Jump up^  "Letter of Denial - Xangold Lutein Esters, Lutein, or Zeaxanthin and Reduced Risk of Age-related Macular Degeneration or Cataract Formation (Docket No. 2004Q-0180". US FDA, Qualified Health Claims. 19 December 2005.
  14. Jump up^  Yu, B.; Wang, J.; Suter, P. M.; Russell, R. M.; Grusak, M. A.; Wang, Y.; Wang, Z.; Yin, S.; Tang, G. (2012). "Spirulina is an effective dietary source of zeaxanthin to humans". British Journal of Nutrition108 (4): 611–619. doi:10.1017/S0007114511005885PMID 22313576.
  15. Jump up^  Frusciante, Sarah; Diretto, Gianfranco; Bruno, Mark; Ferrante, Paola; Pietrella, Marco; Prado-Cabrero, Alfonso; Rubio-Moraga, Angela; Beyer, Peter; Gomez-Gomez, Lourdes (2014-08-19). "Novel carotenoid cleavage dioxygenase catalyzes the first dedicated step in saffron crocin biosynthesis"Proceedings of the National Academy of Sciences111 (33): 12246–12251. doi:10.1073/pnas.1404629111ISSN 0027-8424PMC 4143034Freely accessiblePMID 25097262.
  16. Jump up^  "Foods highest in lutein-zeaxanthin per 100 grams". Conde Nast for the USDA National Nutrient Database, release SR-21. 2014. Retrieved 23 December 2015.
  17. Jump up to:a b Edwards JA (2016). "Zeaxanthin: Review of Toxicological Data and Acceptable Daily Intake"Journal of Ophthalmology2016: 3690140. doi:10.1155/2016/3690140PMC 4738691Freely accessiblePMID 26885380. Retrieved 2016-07-23
    • In their evaluation of the safety of synthetic zeaxanthin as a Novel Food, the EFSA NDA Scientific Panel [37] applied a 200-fold safety factor to this NOAEL to define an ADI of 0.75 mg/kg bw/day, or 53 mg/day for a 70 kg adult.
    • Formulated zeaxanthin was not mutagenic or clastogenic in a series of in vitro and in vivo tests for genotoxicity.
    • Information from human intervention studies also supports that an intake higher than 2 mg/day is safe, and an intake level of 20 mg/day for up to 6 months was without adverse effect.

Source: https://en.wikipedia.org/wiki/Zeaxanthin