Astaxanthin: Difference between revisions

'''Astaxanthin''' is a keto-carotenoid within a group of chemical compounds known as terpenes.{{pmid|15823009}} Astaxanthin is a metabolite of zeaxanthin and canthaxanthin, containing both hydroxyl and ketone functional groups. It is a lipid-soluble pigment with red coloring properties, which result from the extended chain of conjugated (alternating double and single) double bonds at the center of the compound. The presence of the hydroxyl functional groups and the hydrophobic hydrocarbons render the molecule amphiphilic.{{pmid|34371336}}

Astaxanthin is produced naturally in the freshwater microalgae ''Haematococcus pluvialis'' and the yeast fungus ''Xanthophyllomyces dendrorhous'' (also known as ''Phaffia rhodozyma'').<ref>{{cite web|title=''Phaffia rhodozyma'' M.W. Mill., Yoney. & Soneda - Names Record|url=http://www.speciesfungorum.org/Names/NamesRecord.asp?RecordID=319694|website=www.speciesfungorum.org|publisher=Species Fungorum|access-date=9 September 2022}}</ref> This vibrant red-orange pigment is synthesized in algae in response to environmental stress factors such as lack of nutrients, increased salinity, or excessive sunlight. In this context, astaxanthin is considered a xenohormetic compound, as its production is a direct response to stress conditions in the microalgae. Animals who feed on the algae, such as salmon, red trout, red sea bream, flamingos, and crustaceans (shrimp, krill, crab, lobster, and crayfish), subsequently reflect the red-orange astaxanthin pigmentation.