fucoxanthin

{{chembox | Verifiedfields = changed | Watchedfields = changed | verifiedrevid = 437956950 | ImageFile=Fucoxanthin.svg | ImageSize=350px | IUPACName=(3S,5R,6M,3′S,5′R,6′S)-5′,6′-Epoxy-5,3′-dihydroxy-8′-oxo-6,7-didehydro-5,6,5′,6′,7′,8′-hexahydro-β,β-caroten-3-yl acetate | SystematicName=(1S,3R,4M)-3-Hydroxy-4-{(3E,5E,7E,9E,11E,13E,15E,17E)-18-[(1S,4S,6R)-4-hydroxy-2,2,6-trimethyl-7-oxabicyclo[4.1.0]heptan-1-yl]-3,7,12,16-tetramethyl-17-oxooctadeca-1,3,5,7,9,11,13,15,17-nonaen-1-ylidene}-3,5,5-trimethylcyclohexyl acetate | OtherNames= |Section1= |Section2= |Section3= }} Fucoxanthin is a xanthophyll, with formula C42H58O6. It is found as an accessory pigment in the chloroplasts of brown algae and most other heterokonts, giving them a brown or olive-green color. Fucoxanthin absorbs light primarily in the blue-green to yellow-green part of the visible spectrum, peaking at around 510–525 nm and absorbing significantly in the range of 450 to 540 nm.

== Function == Carotenoids are pigments produced by plants and algae and play a role in light harvesting as part of the photosynthesis process. Xanthophylls are a subset of carotenoids, identified by the fact that they are oxygenated either as hydroxyl groups or as epoxide bridges. This makes them more water soluble than carotenes such as beta-carotene. Fucoxanthin is a xanthophyll that contributes more than 10% of the estimated total production of carotenoids in nature. It is an accessory pigment found in the chloroplasts of many brown macroalgae, such as Fucus , and the golden-brown unicellular microalgae, the diatoms. It absorbs blue and green light at bandwidth 450–540 nm, imparting a brownish-olive color to algae. Fucoxanthin has a highly unique structure that contains both an epoxide bond and hydroxyl groups along with an allenic bond (two adjacent carbon-carbon double bonds) and a conjugated carbonyl group (carbon-oxygen double bond) in the polyene chain. All of these features provide fucoxanthin with powerful antioxidant activity.