Fucoxanthin
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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 by various estimates and absorbing significantly in the range of 450 to 540 nm.
Contents
• Function
• Sources
• See also
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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.cite-ref-1[1] It is an accessory pigment found in the chloroplasts of many brown macroalgae, such as Fucus spp., 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.cite-ref-2[2]
In macroalgal plastids, fucoxanthin acts like an antenna for light harvesting and energy transfer in the photosystem light harvesting complexes.cite-ref-3[3] In diatoms like Phaeodactylum tricornutum, fucoxanthin is protein-bound along with chlorophyll to form a light harvesting protein complex.cite-ref-4[4] Fucoxanthin is the dominant carotenoid, responsible for up to 60% of the energy transfer to chlorophyll a in diatoms.cite-ref-5[5] When bound to protein, the absorption spectrum of fucoxanthin expands from 450–540 nm to 390–580 nm, a range that is useful in aquatic environments.cite-ref-6[6]
Sources
Fucoxanthin is present in brown seaweeds and diatoms and was first isolated from Fucus, Dictyota, and Laminaria by Willstätter and Page in 1914.cite-ref-peng-7-0[7] Seaweeds are commonly consumed in south-east Asia and certain countries in Europe, while diatoms are single-cell planktonic microalgae characterized by a golden-brown color, due to their high content of fucoxanthin. Generally, diatoms contain up to four times more fucoxanthin than seaweed, making diatoms a viable source for fucoxanthin industrially.cite-ref-8[8] Diatoms can be grown in controlled environments (such as photobioreactors).
Bioavailability
See also
References
cite-note-22. ↑ citerefhuliuchenwu2010Hu T, Liu D, Chen Y, Wu J, Wang S (March 2010). "Antioxidant activity of sulfated polysaccharide fractions extracted from Undaria pinnitafida in vitro". International Journal of Biological Macromolecules. 46 (2): 193–8. doi:10.1016/j.ijbiomac.2009.12.004. PMID 20025899.
cite-note-44. ↑ citerefguglielmilavaudrousseauetienne2005Guglielmi G, Lavaud J, Rousseau B, Etienne AL, Houmard J, Ruban AV (September 2005). "The light-harvesting antenna of the diatom Phaeodactylum tricornutum. Evidence for a diadinoxanthin-binding subcomplex" (PDF). The FEBS Journal. 272 (17): 4339–48. doi:10.1111/j.1742-4658.2005.04846.x. PMID 16128804.
cite-note-55. ↑ citerefpapagiannakisvan-stokkumfeyb-chel2005Papagiannakis E, van Stokkum IH, Fey H, Büchel C, van Grondelle R (November 2005). "Spectroscopic characterization of the excitation energy transfer in the fucoxanthin-chlorophyll protein of diatoms". Photosynthesis Research. 86 (1–2): 241–50. doi:10.1007/s11120-005-1003-8. PMID 16172942.
cite-note-66. ↑ citerefpremvardhansandbergfeybirge2008Premvardhan L, Sandberg DJ, Fey H, Birge RR, Büchel C, van Grondelle R (September 2008). "The charge-transfer properties of the S2 state of fucoxanthin in solution and in fucoxanthin chlorophyll-a/c2 protein (FCP) based on stark spectroscopy and molecular-orbital theory". The Journal of Physical Chemistry B. 112 (37): 11838–53. doi:10.1021/jp802689p. PMC 2844098. PMID 18722413.
cite-note-peng-77. ↑ citerefpengyuanwuwang2011Peng J, Yuan JP, Wu CF, Wang JH (2011-10-10). "Fucoxanthin, a marine carotenoid present in brown seaweeds and diatoms: metabolism and bioactivities relevant to human health". Marine Drugs. 9 (10): 1806–28. doi:10.3390/md9101806. PMC 3210606. PMID 22072997.