The chemical structure of cryptoxanthin, a yellow tetraterpenoid of the xanthophyll type.

Tetraterpenes are terpenes consisting of eight isoprene units and have the molecular formula C40H64.[1] Tetraterpenoids (including many carotenoids) are tetraterpenes that have been chemically modified, as indicated by the presence of oxygen-containing functional groups.

Phytoene is biosynthesized via the head-to-head condensation of two GGPP molecules.[2] One group of tetraterpenes, and possibly the most studied one, is the carotenoids pigments. Carotenoids have important biological functions, with roles in light capture, antioxidative activity and protection against free radicals, synthesis of plant hormones and as structural components of the membranes. Aside their biological relevance, carotenoids are also high-value compounds for the food and pharmaceutical industries. Carotenoids are biosynthesized by photosynthetic and non-photosynthetic organisms; however, in photosynthetic organisms, they are essential components as accessory pigments for the light-harvesting reaction centers.[3][4][5] Xanthophylls are another group of tetraterpene pigments distributed widely in nature.

References

  1. ↑ Davis, Edward M.; Croteau, Rodney (2000). "Cyclization enzymes in the biosynthesis of monoterpenes, sesquiterpenes, and diterpenes". Biosynthesis. Vol. 209. pp. 53–95. doi:10.1007/3-540-48146-X_2. ISBN 978-3-540-66573-1. {{cite book}}: |journal= ignored (help)
  2. ↑ Umeno D, Tobias AV, Arnold FH (December 2002). "Evolution of the C30 carotenoid synthase CrtM for function in a C40 pathway". Journal of Bacteriology. 184 (23): 6690–9. doi:10.1128/JB.184.23.6690-6699.2002. PMC 135437. PMID 12426357.
  3. ↑ Domonkos I, Kis M, Gombos Z, Ughy B (October 2013). "Carotenoids, versatile components of oxygenic photosynthesis". Progress in Lipid Research. 52 (4): 539–61. doi:10.1016/j.plipres.2013.07.001. PMID 23896007.
  4. ↑ Havaux M (April 1998). "Carotenoids as membrane stabilizers in chloroplasts". Trends in Plant Science. 3 (4): 147–151. doi:10.1016/s1360-1385(98)01200-x.
  5. ↑ Sozer O, Komenda J, Ughy B, Domonkos I, Laczkó-Dobos H, Malec P, Gombos Z, Kis M (May 2010). "Involvement of carotenoids in the synthesis and assembly of protein subunits of photosynthetic reaction centers of Synechocystis sp. PCC 6803". Plant & Cell Physiology. 51 (5): 823–35. doi:10.1093/pcp/pcq031. PMID 20231245.
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