Meso-zeaxanthin
 |
|
 |
|
| Names | |
|---|---|
|
IUPAC name
(1R)-4-[(1E,3E,5E,7E,9E,11E,13E,15E,17E)-18-[(4S)-4-hydroxy-2,6,6-trimethylcyclohexen-1-yl]-3,7,12,16-tetramethyloctadeca-1,3,5,7,9,11,13,15,17-nonaenyl]-3,5,5-trimethylcyclohex-3-en-1-ol
|
|
| Other names
3R,3'S zeaxanthin
|
|
| Identifiers | |
|
3D model (JSmol)
|
|
| ChemSpider | |
|
PubChem CID
|
|
| UNII | |
|
|
|
|
| Properties | |
| C40H56O2 | |
| Molar mass | 568.87144 g/mol |
| Appearance | orange-red |
| insol | |
|
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
|
|
| Infobox references | |
Meso-zeaxanthin (3R,3´S-zeaxanthin) is a xanthophyll carotenoid (as it contains oxygen and hydrocarbons), and is one of the three stereoisomers of zeaxanthin. Of the three stereoisomers, meso-zeaxanthin is the second most abundant in nature (after 3R,3´R-zeaxanthin, which is produced by plants and algae. To date, meso-zeaxanthin has been identified in specific tissues of marine organisms, and more importantly, meso-zeaxanthin has been identified in the macula lutea (from Latin, macula = "spot" and lutea = "yellow") of the human retina.
Carotenoids are essential for animal life, but animals cannot produce them. Indeed, animals obtain carotenoids from diet, with herbivores sourcing them from plants or algae, and carnivores, in turn, sourcing them from herbivores. There is a general consensus that meso-zeaxanthin is not present in plants, but is present in marine species. Originally, it was suggested that meso-zeaxanthin was non-dietary in origin and generated at the macula (the central part of the retina) from retinal lutein (another xanthophyll carotenoid found in the human diet), but this work (limited to animal studies) has since been refuted. Indeed, and consistent with the work by Maoka in 1986, Nolan et al. have shown that meso-zeaxanthin is present in the skin of trout, sardine and salmon, and in the flesh of trout. In a subsequent publication, Nolan´s group detected and quantified the three stereoisomers of zeaxanthin, including meso-zeaxanthin, in the flesh of two different trout species. This is the first publication to report the concentrations of meso-zeaxanthin in a habitually consumed food. Using data from this publication, it is estimated that when an average sized trout (circa 200 g) is consumed, 0.2 mg of natural meso-zeaxanthin is obtained from this source. Moreover, canned sardines can also be considered as a habitual source of meso-zeaxanthin for humans, as sardines presented commercially in this way contain a significant amount of skin, which contains meso-zeaxnthin. However, the concentration of meso-zeaxanthin in sardine skin has not been determined yet. Previously to this research, a publication from Khachick et al., (2002) reported that liver from Japanese Quail (Coturnix japonica) and frog plasma contain meso-zeaxanthin. Of note, frog legs are consumed habitually in France, as they are considered a delicacy of French cuisine.
Also, it is possible that meso-zeaxanthin is generated from other carotenoids consumed in the diet, as carotenoids are known to convert into different carotenoids for functional reasons. For example, it has been suggested that meso-zeaxanthin of trout integuments is derived from astaxanthin, and meso-zeaxanthin in primates (macula lutea) is derived (at least in part) from lutein.
...
Wikipedia