It was first isolated from the anther of the tiger lily (Lilium tigrinum) by P. Karrer and A. Oswald in 1935.*
The name antheraxanthin originates in Greek words ánthos (flower) and xanthos (yellow). When first isolated, 1,200 flowers of tiger lily were required to obtain as few as 25 mg of antheraxanthin1. It is an intermediate product in the xanthophyll cycle which helps plants as well as other organisms to cope with the variable intensity of sunlight during the day. In addition to the above mentioned, this carotenoid can be found in some fruits and vegetables2–7 and in anthers and petals of many yellow plants8.
Dandelions (Taraxacum officinale) growing in the Andes at higher altitudes produced significantly more antheraxanthin under excessive light compared to those growing in lower altitudes. This ability is probably one of the adaptation mechanisms that the dandelion has evolved and which allows it to expand into higher altitudes where it is considered invasive9.
Although dandelion is considered a weed, it is also an important medicinal plant. The whole plant can be utilized: fresh leaves for the preparation of salad, yellow flowers for dandelion wine, and root for tee10. Its common name means “lion’s tooth” in many languages (dandelion in English, dent de lion in French, der Löwenzahn in German).
*Karrer P., Oswald A. Carotinoide aus den Staubbeuteln von Lilium tigrinum. Ein neues Carotinoid: Antheraxanthin. Helv. chim. Acta, 18 (1935) pp. 1303-1305.
1P. Karrer a A. Oswald, “Carotinoide aus den Staubbeuteln von Lilium tigrinum. Ein neues Carotinoid: Antheraxanthin.”, Helvetica Chimica Acta 18, 1303–1305 (1935).
2G. F. Stewart, B. S. Schweigert, J. Hawthorn a J. C. Bauernfeind, Carotenoids as colorants and vitamin a precursors: technological and nutritional applications, Food Science and Technology (Elsevier, 2012).
3F. C. Petry a A. Z. Mercadante, “Composition by LC-MS/MS of new carotenoid esters in mango and citrus.”, Journal of Agricultural and Food Chemistry 64, 8207–8224 (2016).
4F. Shahidi, P. Kolodziejczyk, J. R. Whitaker, A. L. Munguia a G. Fuller, Chemicals via higher plant bioengineering, Advances in Experimental Medicine and Biology – Svazek 464 (Springer Science & Business Media, 2012).
5E. M. Yahia, Fruit and vegetable phytochemicals: chemistry and human health, 2 volumes (John Wiley & Sons, 2017).
6M. Siddiq a M. A. Uebersax, Handbook of vegetables and vegetable processing (John Wiley & Sons, 2018).
7W. J. Hurst, Methods of analysis for functional foods and nutraceuticals, second edition, Functional Foods and Nutraceuticals (CRC Press, 2008).
8T. Goodwin, The biochemistry of the carotenoids: volume i plants (Springer Science & Business Media, 2012).
9M. A. Molina-Montenegro, J. Peñuelas, S. Munné-Bosch a J. Sardans, “Higher plasticity in ecophysiological traits enhances the performance and invasion success of Taraxacum officinale (dandelion) in alpine environments.”, Biological Invasions 14, 21–33 (2012).
10Ladislav Hoskovec, Taraxacum sect. ruderalia kirschner, h. øllgaard et štepánek – pampelišky / púpavy, https://botany.cz/cs/taraxacum-rudera lia/, (accessed: 27.07.2018).
It was first isolated from the European lobster (Homarus gammarus) by R. Kuhn and E. Lederer in 1933.*
Astaxanthin is known for its presence in many aquatic organisms, such as salmons, trouts, krill, shrimp, crayfish or crustaceans1. Another animal that has a reddish colour due to the consumption of astaxanthin is a flamingo (chicks are born with grey feather). Captive flamingos with insufficient access to natural food lose their colour2. The same thing happened with the meat of farmed salmon. Therefore, carotenoids, mainly astaxanthin and canthaxanthin, are added to their diet1,3. Astaxanthin is also used in the breeding of hens for better colour of yolk. Astaxanthin is usually marked on the packing as E161j. A large part of the production of this carotenoid also goes to the cosmetics industry4.
There are two main ways to obtain astaxanthin. The first one is synthetic using petrochemistry. The second one is growing algae rich in this carotenoid and the subsequent extraction of it. Haematococcus pluvialis is one of the algae that is used for this purpose5. The Czech company Algamo also uses this algae for the production of astaxanthin6. The estimate of the global market with astaxanthin was around $555.4 billion in 20164.
*Kuhn R., Lederer E. Über die Farbstoffe des Hummers (Astacus gammarus L.) und ihre Stammsubstanz, das Astacin. Ber. dtsch. Chem. Ges. A/B, 66 (1933) pp. 488–495.
1 R. R. Ambati, S. M. Phang, S. Ravi a R. G. Aswathanarayana, “Astaxanthin: sources, extraction, stability, biological activities and its commercial applications–a review.”, Marine Drugs 12, 128–152 (2014).
2 D. L. Fox, “Astaxanthin in the American Flamingo.”, Nature 175, 942–943 (1955).
3 I. Higuera-Ciapara, L. Félix-Valenzuela a F. M. Goycoolea, “Astaxanthin: A Review of its Chemistry and Applications.”, Critical Reviews in Food Science and Nutrition 46, 185–196 (2006).
4 Grand View Research, Astaxanthin market analysis by source (natural [yeast, krill/shrimp, microalgae] and synthetic), by product (dried biomass/ powder, oil, soft gels, liquid), by application, and segment forecasts, 2018 - 2025, https : / / www . grandviewresearch . com / industry - analysis/global-astaxanthin-market, (accessed: 19.07.2018).
5 R. T. Lorenz a G. R. Cysewski, “Commercial potential for Haematococcus microalgae as a natural source of astaxanthin.”, Trends in Biotechnology 18, 160–167 (2000).
6 Algamo, Algamo - Technologie, http://www.algamo.cz/astaxanthin-techn ologie/, (accessed: 19.07.2018).
It was first isolated from achiote (Bixa orellana) by C. Etti in 1878.*
Bixin is still obtained from the fruit of the achiote (Bixa orellana). This evergreen shrub reaching up to ten meters originating in tropical America (original range from Brazil to the south of Mexico) got its Latin species name from the Spanish conquistador Francisco de Orellana (author of the name of the Amazon River)1,2. In the 17th century, the achiote spread to other tropical countries due to Spanish and Portuguese sailors2.
The spice that is obtained from the waxy arils covering the seeds is called annatto. It contains approximately 5% of dyes, 70-80% consists of bixin3. Native tribes used bixin in rituals to dye their skin4. Bixin was also found in ink in a manuscript from Mexico from the 16th century5. In India, achiote is used in the traditional medicine and is also used for the production of sindoor, a cosmetic powder6.
Today, the carotenoid is mainly used in the food industry (e.g. colouring of the surface of cheese, other dairy products, bakery products, margarine, breakfast cereals)2. Annatto, together with bixin and norbixin, are marked on the packing as E160b.
*Etti C. Ueber das Bixin. Ber. Dtsch. Chem. Ges., 11 (1878) pp. 864–870.
1 V. Grulich, Bixa orellana (l.) kuntze – oreláník barvírský, https://botan y.cz/cs/bixa-orellana/, (accessed: 19.07.2018).
2 G. J. Lauro a J. Francis, Natural food colorants: science and technology, Ift Basic Symposium (CRC Press, 2000).
3 The Raintree Group, “Toxicity profile: Annatto.”, British Industrial Biological Research Association, (Carshalton, Surrey, UK) 5 (1986).
4 J. R. Lovera, Food culture in south america, Food culture around the world (Greenwood Publishing Group, 2005).
5 M. E. Haude, Identification and classification of colorants used during mexico’s early colonial period, http://cool.conservation-us.org/coolaic/ sg/bpg/annual/v16/bp16-05.html, (accessed: 19.07.2018). xlii
6 N. P. Manandhar a S. Manandhar, Plants and people of nepal (Timber Press, Incorporated, 2002).
It was first isolated from a fungus Cantharellus cinnabarinus (chanterelles ) by F. Haxo in 1950.*
Cantharellus cinnabarinus got its species name from a mineral called cinnabarite which has a beautiful scarlet colour1. In addition to this edible fungus, canthaxanthin in also found in green algae, bacteria, crustaceans, or fish2. It is a relatively common carotenoid in nature that serves for example as an antioxidant in animal tissues3. Together with asthaxanthin, it is used in the feeding of farmed fish for better colour of their meat4. The carotenoid is also a part of most of so-called tanning pills. When used in larger quantities, canthaxathin is stored in certain parts of subcutaneous fat and colours the skin so it looks tanned2. A few people who have taken a large (or rather excessive) amount of these pills have developed a disease called retinopathy, which is the deposition of canthaxanthin on the eye retina and formation of its crystals. However, the affected people fully recovered when they stopped taking the canthaxanthin pills5,6. Also due to these extreme cases, the acceptable daily intake for canthaxanthin was set at 0.03 mg per kilogram bodyweight7. Canthaxanthin is referred to as E161g on the packing.
*Haxo F. Carotenoids of the Mushroom Cantharellus cinnabarinus, Botanical Gazette 112, 2, (1950) pp. 228-232.
1 F. Haxo, “Carotenoids of the mushroom Cantharellus cinnabarinusCantharellus cinnabarinus.”, Botanical Gazette 112, 228–232 (1950).
2 M. Garone, J. Howard a J. Fabrikant, “A Review of Common Tanning Methods.”, The Journal of Clinical and Aesthetic Dermatology 8, 43–47 (2015).
3 S. Sanchez, B. Ruiz, R. Rodríguez-Sanoja a L. B. Flores-Cotera, “Microbial Production of Food Ingredients, Enzymes and Nutraceuticals, 9 - Microbial production of carotenoids.”, Woodhead Publishing Series in Food Science, Technology and Nutrition, 194–233 (2013).
4 D. Asker a Y. Ohta, “Production of canthaxanthin by Haloferax alexandrinusHaloferax alexandrinus under non-aseptic conditions and a simple, rapid method for its extraction.”, Applied Microbiology and Biotechnology 58, 743–750 (2002).
5 C. Harnois, J. Samson, M. Malenfant a A. Rousseau, “Canthaxanthin retinopathy. Anatomic and functional reversibility.”, Archives of Ophthalmology 107, 538–540 (1989).
6 A. Hueber, A. Rosentreter a M. Severin, “Canthaxanthin retinopathy: Long-term observations.”, Ophthalmic Research 46, 103–106 (2011).
7 E. F. S. A. (EFSA), Parma a Italy, “Scientific opinion on the safety and efficacy of canthaxanthin as a feed additive for poultry and for ornamental birds and ornamental fish.”, EFSA Journal 12, – (2014).
They were first isolated from a pepper Capsicum annuum by L. Zechmeister and L. V. Cholnoky in 1927 (capsanthin*) a 1934 (capsorubin**).
Capsicum annuum is a plant native to North America and northern South America. The Latin species name of this species – annuum (annual) – can be slightly misleading. If grown in a place where there is no winter frost it can grow for several years until it becomes a small shrub1.
In addition to its taste and colour, the pepper can be interesting also from a health point of view. Several studies have already focused in this direction. In one of them, weight loss was recorded in animals that drank a drink made from pepper instead of water for six weeks2.
The so-called pepper extract is obtained from the pepper using organic solvents. Its main ingredients are capsaicin (a burning agent, also used in pepper sprays), capsanthin and capsorubin. You can find this extract marked as E160c for example in cheese, jams, sausages, cereals, or fish products3.
*Zechmeister L., v. Cholnoky L. Untersuchungen über den Paprika- Farbstoff. I. Justus Liebigs Ann. Chem., 454, (1927) pp. 54–71.
**Zechmeister L., v. Cholnoky L. Untersuchungen über den Paprika- Farbstoff. VII (Adsorptionsanalyse des Pigments). Justus Liebigs Ann. Chem., 509, (1934) pp. 269–287.
1 Wikipedia, Capsicum annuum, https://en.wikipedia.org/wiki/Capsicum_annuum, (accessed: 20.07.2020).
2 K. Aizawa, T. Matsumoto, T. Inakuma, T. Ishijima, Y. Nakai, K. Abe, F. Amano, “Administration of tomato and paprika beverages modifies hepatic glucose and lipid metabolism in mice: A DNA microarray analysis.”, J. Agric. Food Chem. 57, 10964–10971 (2009).
3 Fér potravina, E160c - Paprikový extrakt, Kapsanthin, Kapsorubin, https://www.ferpotravina.cz/seznam-ecek/E160c, (accessed: 20.07.2020).
It was first isolated from the flavedo of the Sinton citrangequat by H. Yokoyama and M. J. White in 1965.*
The vast majority of citranaxanthin is produced synthetically1, despite the existence of its natural resources, such as the citrus Sinton citrangequat (a hybrid of the orange (Citrus sinensis), the trifoliate orange (Poncirus trifoliata) and a kumquat (Fortunella sp.)). The three most famous cultivars are named Sinton, Thomasville and Telfair. The former, from which the citranaxanthin was first isolated, was named after the city of Sinton, Texas (USA)2. Interestingly, although certain carotenoids are present in large quantities in the citrus hybrids, in the parent species there are usually fewer of them. For example, reticulataxanthin, another carotenoid present in the citrus Sinton citrangequat, makes up about a half of all carotenoids in fruits of this specie. In the parent hybrids, however, it occurs only in trace amounts3.
Citranaxanthin is mainly used in the food industry, where it is used together with other carotenoids as a supplement in feeding hens or chickens to improve the colour of egg yolk or chicken fat (citranaxanthin adds a red colour, whereas, for example, lutein adds yellow colour)4,5. Citranaxanthin is marked on the packing as E161i.
*Yokoyama H., White M. J. Citrus Carotenoids. II. The Structure of Citranaxanthin, a New Carotenoid Ketone. J. Org. Chem., 30, 7, (1965) pp. 2481–2482.
1 E. Burton, J. Gatcliffe, H. M. O’Neill a D. Scholey, Sustainable poultry production in europe, Poultry Science Symposium Series – Vydání 31 (CABI, 2016).
2 W. T. Swingle a T. R. Robinson, “Two important new types of citrous hybrids for the home garden, citrangequats and limequats.”, Journal of Agricultural Research 23, 229–238 (1923).
3 M. Ladanyia, Citrus fruit: biology, technology and evaluation (Academic Press, 2010).
4 L. M. Sandeski, E. H. G. Ponsano a M. G. Neto, “Optimizing xanthophyll concentrations in diets to obtain well-pigmented yolks.”, The Journal of Applied Poultry Research 23, 409–417 (2014).
5 I. INCHEM, Citranaxanthin, http://www.inchem.org/documents/jecfa/ jecmono/v22je11.htm, (accessed: 19.07.2018).
They were first isolated from saffron crocus (Crocus sativus) by P. Karrer and H. Salomon in 1927.*
The history of cultivating saffron for cooking dates back to at least three thousand years ago1. This spice is obtained from the dried styles of the saffron crocus flower. It gives the food both a bitter taste and a beautiful yellow colour. The colour is caused by crocin and crocetin – water-soluble carotenoids (which is a big exception among carotenoids)2,3. Due to the method of obtaining the saffron, this spice was and still is considered a luxury item1,4 - hence the phrase “as scarce as saffron” (and also because 20 g of saffron is considered a lethal dose)5. In the middle of the 14th century, a two-week “Saffron War” was even unleashed. It began after the nobility, dissatisfied with increasingly wealthier merchants, stole a shipment of saffron6. At that time, saffron was even more valuable than ever because people believed in its healing effects against the terrible plague7.
Although saffron was not very successful in fighting plague, it is once again in the spotlight of scientists looking for new drugs. Saffron, and especially crocetin, havs been shown to help prevent or even treat breast cancer, lung cancer, pancreatic cancer, and leukemia8. Crocetin has also been tested with promising results in the treatment of mice with Alzheimer’s and Parkinson’s disease2.
*Karrer P., Salomon H. Über Pflanzenfarbstoffe III. Zur Kenntnis der Safranfarbstoffe I. HCA, 10, (1927) pp. 397–405.
1 B. Deo, “Growing saffron - the world’s most expensive spice.”, Crop & Food Resesarch 20 (2003).
2 V. R. P. Ronald Ross Watson, Bioactive nutraceuticals and dietary supplements in neurological and brain disease: prevention and therapy (Academic Press, 2015).
3 S. H. Alavizadeh a H. Hosseinzadeh, “Bioactivity assessment and toxicity of crocin: A comprehensive review.”, 64, 65–80 (2014).
4 J. A. McGimpsey, M. H. Douglas a A. R. Wallace, “Evaluation of saffron (Crocus sativus L.) production in New Zealand.”, New Zealand Journal of Crop and Horticultural Science 25, 159–168 (1997).
5 M. Schmidt, G. Betti a A. Hensel, “Saffron in phytotherapy: Pharmacology and clinical uses.”, Wiener Medizinische Wochenschrift 157, 315–319 (2007).
6 C. L. K. Mary Newman, Edible flowers: a global history (Reaktion Books, 2016).
7 Z. A. Shah, R. Mir, J. M. Matoo, M. A. Dar a M. A. Beigh, “Medicinal importance of saffron: A review.”, Journal of Pharmacognosy and Phytochemistry 6, 2475–2478 (2017).
8 W. G. Gutheil, G. Reed, A. Ray, S. Anant a A. Dhar, “Crocetin: an agent derived from saffron for prevention and therapy for cancer.”, Current Pharmaceutical Biotechnology 13, 173–179 (2012).
It was first isolated from the extremophilic spherical bacterium Deinococcus radiodurans by L. Lemee, E. Peuchant, M. Clerc, M. Brunner and H. Pfander in 1997.*
The red bacterium Deinococcus radiodurans rightly deserves the adjective extremophilic. It is resistant to low temperature, dehydration, acidic environment, or vacuum1. However, it was discovered due to its ability to withstand high doses of radiation (it has been listed in The Guinness Book of World Records as the most radiation-resistant life form)2. In 1956, A. W. Anderson explored the possibilities of sterilizing food using high doses of γ-radiation. Even though the canned beef was exposed to a high dose of radiation, it spoiled just because of Deinococcus radiodurans3. The bacterium is able to survive radiation with an intensity of 15,000 grays (the lethal dose for humans is about 5 Gy)2,4.
This ability is probably also influenced by deinoxanthin, the carotenoid produced by the bacterium. It has greater antioxidant effects than other carotenoids5. Mutants of Deinococcus radiodurans, in which the carotenoid synthesis has been blocked, were more sensitive to radiation6. A possible use of this bacterium can be, for example, the decomposition of toxic to non-toxic substances (the so-called bioremediation) in radioactively contaminated areas7.
*Lemee L., Peuchant E., Clerc M., Brunner M., Pfander H. Deinoxanthin: A new carotenoid isolated from Deinococcus radiodurans. Tetrahedron, 53, 3 (1997) pp. 919-926.
1 R. Jaafar, A. Al-Sulami, A. Al-Taee, F. Aldoghachi a S. Napes, “Biosorption and bioaccumulation of some heavy metals by Deinococcus radiodurans isolated from soil in Basra governorate- Iraq.”, Journal of Biotechnology & Biomaterials 5, 190 (2015).
2 G. W. Records, Most radiation-resistant lifeform, http : / / www . guinnes sworldrecords.com/world- records/most- radiation- resistant- lifeform, (accessed: 19.07.2018).
3 A. W. Anderson, H. C. Nordan, R. F. Cain, G. Parrish a D. Duggan, “Studies on a radio-resistant Micrococcus. I. Isolation, morphology, cultural characteristics, and resistance to gamma radiation.”, Food Technology 10, 575–577 (1956).
4 S. G. Levin, R. W. Young a R. L. Stohler, “Estimation of median human lethal radiation dose computed from data on occupants of reinforced concrete structures in Nagasaki, Japan.”, Health Physics 63, 522–531 (1992).
5 H.-F. Ji, “Insight into the strong antioxidant activity of deinoxanthin, a unique carotenoid in Deinococcus radiodurans.”, International Journal of Molecular Sciences 11, 4506–4510 (2010).
6 B. Tian, Z. X. amd Z. Sun, J. Lin a Y. Hua, “Evaluation of the antioxidant effects of carotenoids from Deinococcus radiodurans through targeted mutagenesis, chemiluminescence, and DNA damage analyses.”, Biochimica et Biophysica Acta (BBA) - General Subjects 1770, 902–911 (2007).
7 H. Brim, S. C. McFarlan, J. K. Fredrickson, K. W. Minton, M. Zhai, L. P. Wackett a M. J. Daly, “Engineering Deinococcus radiodurans for metal remediation in radioactive mixed waste environments.”, Nature Biotechnology 18, 85–90 (2000).
It was first isolated from the purple sea urchin (Paracentrotus lividus) by E. Lederer in 1935.*
Echinenone naturally occurs in cyanobacteria, algae, invertebrates living in oceans, and bacteria1–3. This ketocarotenoid (containing a keto-group C=O) can also be obtained from some genetically modified plants, such as carrots, tobacco, or potatoes. In the tubers and leaves of genetically modified potatoes, ketocarotenoids accounted for approximately one tenth of all present carotenoids4. Genetically modified tobacco has been reported to have reduced efficiency of photosynthesis (probably due to increase in the content of various ketocarotenoids, including echinenone)5. Carrots that have been genetically modified to produce more ketocarotenoids (including echinenone) have been shown to grow faster in ultraviolet light, and to better manage oxidative stress6.
One can find echinenone also in cuisine because the orange-coloured gonads of the purple sea urchin (Paracentrotus lividus), from which the echinenone was first isolated, are considered delicacy in the Mediterranean7. On the other hand, the urchin is rather unpopular with tourists who can step on it along the coast. Echinenone is an intermediate product in the conversion of β-carotene to canthaxanthin.
*Lederer E. Echinenone and pentaxanthin; two new carotenoids in the sea urchin (Echinus esculentus). Compt. Rend., 201 (1935) pp. 300-302.
1 T. W. Goodwin, Chemistry and biochemistry of plant pigments, Chemistry and Biochemistry of Plant Pigments (Academic Press, 1965).
2 R. A. Lewin, Physiology and biochemistry of algae (Academic Press, 1962).
3 P. Beyer, H. Kleinig, G. Englert, W. Meister a K. Noack, “Carotenoids of Rhizobia. IV. Isolation and structure elucidation of the carotenoids of a mutant of Rhizobium lupini.”, Helvetica Chimica Acta 62, 2551–2557 (1979).
4 T. Gerjets a G. Sandmann, “Ketocarotenoid formation in transgenic potato.”, Journal of Experimental Botany 57, 3639–3645 (2006).
5 C. Zhu, T. Gerjets a G. Sandmann, “Nicotiana glauca engineered for the production of ketocarotenoids in flowers and leaves by expressing the cyanobacterial crtO ketolase gene.”, Transgenic Research 16, 813–821 (2007).
6 J. Jayaraj a Z. K. Punja, “Transgenic carrot plants accumulating ketocarotenoids show tolerance to UV and oxidative stresses.”, Plant Physiology and Biochemistry 46, 875–883 (2008).
7 J. M. Lawrence, Edible sea urchins: biology and ecology, Developments in Aquaculture and Fisheries Science – Svazek 38 (Elsevier, 2006).
It was first isolated from California poppy (Eschscholzia californica) by H. H. Strain in 1938.*
In his article, in which by the way he relatively accurately estimated its structure, H. H. Strain described two methods of obtaining eschscholtzxanthin. In the first one, he used 63,000(!) petals (weighing 8.15 kg), and in the second one, he stated that the weight of the used petal was only 3 kg1.
Eschscholtzxanthin belongs to the group of retro-carotenoids, together with for example tangeraxanthin (see below), which means that the double bonds in the carbon chain of these carotenoids are shifted by one position2. Eschscholtzxanthin is found in the leaves of the boxwood (Buxus sempervirens) in winter, and its role in leaf protection during this period is being considered3,4.
The California poppy, from which the carotenoid was first isolated, was named after the Baltic-German doctor and scientist Johann Friedrich von Eschscholtz. It is the official flower of California where a national holiday is celebrated on April 6 in its honour. This plant was traditionally used by the native Americans as an analgesic and sedative5,6. Today, it is possible to buy an extract in the form of drops. It is mainly grown as an ornamental plant for its beautiful yellow flower. However, it sometimes escapes from the gardens and in several areas is considered invasive7.
*Strain H. H. Eschscholtzxanthin: A new xanthophyll from the petals of the Californian poppy, Eschscholzia californica. J. Biol. Chem., 123 (1938) pp. 425-437.
1 H. H. Strain, “Eschscholtzxanthin: A new xanthophyll from the petals of the california poppy, Eschscholtzia californica.”, Journal of Biological Chemistry 123, 425–437 (1938).
2 IUPAC a IUPAC-IUB, “Nomenclature of carotenoids (rules approved 1974).”, Butterworths, London, – (1974).
3 K. Hormaetxe, A. Hernández, J. M. Becerril a J. I. García-Plazaola, “Role of red carotenoids in photoprotection during winter acclimation in Buxus sempervirens leaves.”, Plant Biology 6, 325–332 (2004).
4 K. Hormaetxe, J. M. Becerril, I. Fleck, M. Pintó a J. I. García-Plazaola, “Functional role of red (retro)-carotenoids as passive light filters in the leaves of Buxus sempervirens L.: increased protection of photosynthetic tissues?.”, Journal of Experimental Botany 56, 2629–2636 (2005).
5 A. Rolland, J. Fleurentin, M.-C. Lanhers, C. Younos, R. Misslin, F. Mortier a J. M. Pelt, “Behavioural effects of the American traditional plant Eschscholzia californica: sedative and anxiolytic properties.”, Planta Medica 57, 212–216 (1991).
6 M. Fedurco, J. Gregorová, K. Šebrlová, J. Kantorová, O. Peš, R. Baur, E. Sigel a E. Táborská, “Modulatory effects of Eschscholzia californica alkaloids on recombinant GABAA receptors.”, Biochemistry Research International 2015, – (2015).
7 L. Kovár, Eschscholzia californica cham. – sluncovka kalifornská / slncovka kalifornská, https : / / botany . cz / cs / eschscholzia - californica/, (accessed: 30.07.2018).
It was first isolated from brown seaweeds (genera Fucus, Dictyota and Laminaria) by R. Willstätter and H. J. Page in 1914.*
Fucoxanthin occurs naturally in brown seaweeds, such as for example Laminaria japonica (Ma-Kombu), Phaeodactylum tricornutum, Cylindrotheca closterium or Undaria pinnatifida (wakame)1. The latter is considered invasive worldwide2. Fucoxanthin extracted from this alga has been shown to reduce obesity. The experiments were first performed on mice3, later also on women with liver problems, in whom a dietary supplement with fucoxanthin caused a significant weight loss4. There are many studies examining the effect of fucoxanthin on obesity, see for instance [5–9].
The aspects of fucoxanthin in treatment of other diseases of affluence, such as diabetes, high cholesterol, cancer, or cardiovascular disease are also examined1,10,11. It must be noted that this research has very promising results.
If one decide to cook brown seaweed, it is better to use fish oil because fucoxanthin better dissolves in it and the body absorbs it more easily. In contrast, fucoxanthin dissolves worse in vegetable fats12.
*Willstätter R., Page H. J. Untersuchungen über Chlorophyll. XXIV. Über die Pigmente der Braunalgen. Justus Liebigs Ann. Chem., 404 (1914) pp. 237–271.
1 H. Zhang, Y. Tang, Y. Zhang, S. Zhang, J. Qu, X.Wang, R. Kong, C. Han a Z. Liu, “Fucoxanthin: A Promising Medicinal and Nutritional Ingredient.”, Evidence-Based Complementary and Alternative Medicine 2015, 723515 (2015).
2 T. G. I. S. Database, 100 of the world’s worst invasive alien species, http://www.iucngisd.org/gisd/100_worst.php, (accessed: 20.07.2018).
3 H. Maeda, M. Hosokawa, T. Sashima, K. Funayama a K. Miyashita, “Fucoxanthin from edible seaweed, Undaria pinnatifida, shows antiobesity effect through UCP1 expression in white adipose tissues.”, Biochemical and biophysical research communications 332, 392–397 (2005).
4 M. Abidov, Z. Ramazanov, R. Seifulla a S. Grachev, “The effects of XanthigenTM in the weight management of obese premenopausal women with non-alcoholic fatty liver disease and normal liver fat.”, Diabetes, Obesity and Metabolism 12, 72–81 (2010).
5 K. Muradian, A. Vaiserman, K. J. Min a V. E. Fraifeld, “Fucoxanthin and lipid metabolism: A minireview.”, Nutrition, metabolism, and cardiovascular diseases 25, 891–897 (2015).
6 H. Maeda, T. Tsukui, T. Sashima, M. Hosokawa a K. Miyashita, “Seaweed carotenoid, fucoxanthin, as a multi-functional nutrient.”, Asia Pacific journal of clinical nutrition 17, 196–199 (2008).
7 H. Maeda, M. Hosokawa, T. Sashima, K. Murakami-Funayama a K. Miyashita, “Anti-obesity and anti-diabetic effects of fucoxanthin on diet-induced obesity conditions in a murine model.”, Molecular medicine reports 2, 897– 902 (2009).
8 S. M. Jeon, H. J. Kim, M. N.Woo, M. K. Lee, Y. C. Shin, Y. B. Park a M. S. Choi, “Fucoxanthin-rich seaweed extract suppresses body weight gain and improves lipid metabolism in high-fat-fed C57BL/6J mice.”, Biotechnology journal 5, 961–969 (2010).
9 M. A. Gammone a N. D’Orazio, “Anti-obesity activity of the marine carotenoid fucoxanthin.”, Marine drugs 13, 2196–2214 (2015).
10 T. Rengarajan, P. Rajendran, N. Nandakumar, M. P. Balasubramanian a I. Nishigaki1, “Cancer preventive efficacy of marine carotenoid fucoxanthin: Cell cycle arrest and apoptosis.”, Nutrients 5, 4978–4989 (2013).
11 A. Rwigemera, J. Mamelona a L. J. Martin, “Comparative effects between fucoxanthinol and its precursor fucoxanthin on viability and apoptosis of breast cancer cell lines MCF-7 and MDA-MB-231.”, Anticancer Research 35, 207–219 (2015).
12 H. Maeda, M. Hosokawa, T. Sashima a K. Miyashita, “Dietary combination of fucoxanthin and fish oil attenuates the weight gain of white adipose tissue and decreases blood glucose in obese/diabetic KK-Ay mice.”, Journal of agricultural and food chemistry 55, 7701–7706 (2007).
It was first isolated from the chicken retina by G. Wald in 1948.*
In his article describing the discovery of the new carotenoid, G. Wald drew an assumption that galloxanthin in the chicken retina serves as an auxiliary pigment for differentiating colours, or for excluding violet and near ultraviolet light1. In this respect, research is still carried out on birds and other animals.
Some bird species (e.g. zebra finch (Taeniopygia guttata) or (Columbidae) family) have four types of photoreceptor cells distinguishing colours2,3 (unlike man who lost two of these cells in the course of evolution and later evolved a third one again4). In the eyes of these birds, the carotenoids are dissolved in small droplets of fat located in front of the photoreceptor cells, and filter the light passing through them. This increases the ability of distinguishing colours which gives individuals with this ability a competitive advantage3 and also helps them choose a partner2.
In addition to chicken retina, galloxanthin has been found for example in ayu (Plecoglossus altivelis), a fish native to East Asia5. Among other methods, specially trained cormorants are used in Japan to catch ayu. The bird catches the ayu and delivers it to the fishermen6.
*Wald G. Galloxanthin, a carotenoid from the chicken retina. J. Gen. Physiol. 31, 5, (1948) pp. 377–383.
1 G. Wald, “Galloxanthin, a carotenoid from the chicken retina.”, The Journal of general physiology 31, 377–383 (1948).
2 A. T. D. Bennett, I. C. Cuthill, J. C. Partridge a E. J. Maier, “Ultraviolet vision and mate choice in zebra finches.”, Nature 380, 433–435 (1996).
3 M. Vorobyev, D. Osorio, A. T. D. Bennett, N. J. Marshall a I. C. Cuthill, “Tetrachromacy, oil droplets and bird plumage colours.”, Journal of Comparative Physiology A 183, 621–633 (1998).
4 C. A. Arrese, N. S. Hart, N. Thomas, L. D. Beazley a J. Shand, “Trichromacy in Australian marsupials.”, Current Biology 12, 657–660 (2002).
5 E. Yamashita, Y. Maruyama, M. Katsuyama, M. Tsushima, S. Arai a T. Matsuno, “The Presence and Origin of an Apocarotenoid, Galloxanthin in Ayu Plecoglossus altivelis.”, Fisheries Science 64, 826–830 (1998).
6 Cormorant fishing ukai, http : / / www . gifu - rc . jp / ukai / u _ main . html, (accessed: 23.07.2018).
It was first isolated from the sea pineapple (Halocynthia roretzi) by T. Matsuno and M. Ookubo in 1981.*
The sea pineapple is seafood which is used mainly in Korean and less also in Japanese cuisine. In Korea, it is consumed mainly raw marinated in gochujang (spicy fermented Korean condiment). In Japan, it is most often served as sashimi (thin slices) marinated in soy sauce1. Lipids extracted from the sea pineapple, which among others contained also carotenoids, reduced blood fat and sugar levels in mice fed with it for five weeks2.
Halocynthiaxanthin could be used for a treatment of cancer in the future. Some drugs, together with this carotenoid, can trigger a process in cancer cell in which the cells ‘commit suicide’ due to an intracellular program (so-called apoptosis, one of the types of programmed cell death)3. In other research, the addition of halocynthiaxanthin to an ineffective treatment caused cancer cells to die again. This ability of halocynthiaxanthin used together with fucoxanthinol has been demonstrated in leukemia, breast cancer and colorectal cancer4.
*Matsuno T., Ookubo M. A new carotenoid, halocynthiaxanthin from the sea squirt, halocynthia roretzi. Tetrahedron Letters, 22, 46 (1981) pp. 4659-4660.
1 T. T. T. Nguyen, N. Taniguchi, M. Nakajima, U. Na-Nakorn, N. Sukumasavin a K. Yamamoto, “Aquaculture of sea-pineapple, Halocynthia roretzi in Japan.”, Aquaculture Asia 12, 21–23 (2007).
2 N. Mikami, M. Hosokawa a K. Miyashita, “Effects of sea squirt (Halocynthia roretzi) lipids on white adipose tissue weight and blood glucose in diabetic/obese KK-Ay mice.”, Molecular Medicine Reports 3, 449–453 (2010).
3 T. Yoshida, T. Maoka, S. K. Das, K. Kanazawa, M. Horinaka, M. Wakada, Y. Satomi, H. Nishino a T. Sakai, “Halocynthiaxanthin and peridinin sensitize colon cancer cell lines to tumor necrosis factor-related apoptosisinducing ligand.”, Molecular Cancer Research 5, 615–625 (2007).
4 I. Konishi, M. Hosokawa, T. Sashima, H. Kobayashi a K. Miyashita, “Halocynthiaxanthin and fucoxanthinol isolated from Halocynthia roretzi induce apoptosis in human leukemia, breast and colon cancer cells.”, Comparative Biochemistry and Physiology. Toxicology & Pharmacology 142, 53–59 (2006).
It was first isolated from an isopod Idotea metallica by P. J. Herring in 1969.*
Idoxanthin is a xanthophyll occurring mainly in aquatic organisms, for example in salmon or carp (special red breed)1–4. Its presence in the Atlantic salmon (Salmo salar) is mainly due to the fact that idoxanthin is a metabolite of astaxanthin which the wild individuals obtain from food3 (farmed individuals are artificially fed with it)5–8.
Idoxanthin has been also found in meat, skin and ovaries of another salmonid fish, Arctic char (Salvelinus alpinus)9. The smaller the individual of this species, the higher the ratio of idoxanthin to astaxanthin2. On the contrary, in some studies, this carotenoid was not found in large adult individuals10.
In addition to the alpine lakes and the arctic and subarctic coastal areas, the Arctic char also occurs in one prodigious place – in the Canadian lake Pingualuit. This lake of a circular shape was formed about 1.4 million years ago by a meteorite impact. The Arctic char is the only fish species that has been discovered to live in the lake so far11. Over time, the individuals living in this lake have shrunk their body and their heads have become disproportionately large12.
*Herring P. J. Pigmentation and carotenoid metabolism of the marine isopod Idotea metallica. Journal of the Marine Biological Association of the United Kingdom, 49, 3, (1969) pp. 767-779.
1 T. Matsuno, S. Nagata, M. Iwahashi, T. Koibk a M. Okada, “Intensification of color of fancy red carp with zeaxanthin and myxoxanthophyll, major carotenoid constituents of Spirulina.”, Nippon Suisan Gakkaishi 45, 627– 632 (1979).
2 G. H. Aas, B. Bjerkeng, B. Hatlen a T. Storebakken, “Idoxanthin, a major carotenoid in the flesh of Arctic charr (Salvelinus alpinus) fed diets containing astaxanthin.”, Aquaculture 150, 135–142 (1997).
3 K. Schiedt, P. Foss, T. Storebakken a S. Liaaen-Jensen, “Metabolism of carotenoids in salmonids—I. idoxanthin, a metabolite of astaxanthin in the flesh of atlantic salmon (Salmon salar, L.) under varying external conditions.”, Comparative Biochemistry and Physiology Part B: Comparative Biochemistry 92, 277–281 (1989).
4 K. Schiedt, H. Mayer, M. Vecchi, E. Glinz a T. Storebakken, “Metabolism of carotenoids in salmonids*. Part 2*. Distribution and absolute configuration of idoxanthin in various organs and tissues of one atlantic salmon (Salmo salar, L.) fed with astaxanthin.”, Helvetica Chimica Acta 71, 881– 886 (1988).
5 H. Rajasingh, L. Øyehaug, D. I. Våge a S. W. Omholt, “Carotenoid dynamics in Atlantic salmon.”, BMC Biology 4 (2006) https://doi.org/10. 1186/1741-7007-4-10.
6 T. Storebakken a H. K. No, “Pigmentation of rainbow trout.”, Aquaculture 100, 209–229 (1992).
7 O. J.Torrissen, “Pigmentation of salmonids: Interactions of astaxanthin and canthaxanthin on pigment deposition in rainbow trout.”, Aquaculture 79, 363–374 (1989).
8 T. Storebakken, P. Foss, K. Schiedt, E. Austreng, S. Liaaen-Jensen a U. Manz, “Carotenoids in diets for salmonids: IV. Pigmentation of Atlantic salmon with astaxanthin, astaxanthin dipalmitate and canthaxanthin.”, Aquaculture 65, 279–292 (1987).
9 B. Bjerkeng, B. Hatlen a M. Jobling, “Astaxanthin and its metabolites idoxanthin and crustaxanthin in flesh, skin, and gonads of sexually immature and maturing Arctic charr (Salvelinus alpinus (L.)).”, Comparative Biochemistry and Physiology Part B: Biochemistry and Molecular Biology 125, 395–404 (2000).
10 K. Schiedt, “New aspects of carotenoid metabolism in animals.”, CarotenoidsChemistry and Biology, 247–268 (1989).
11 N. Gantner, J. Veillette, W. K. Michaud, R. Bajno, D. Muir, W. F. Vincent, M. Power, B. Dixon, J. D. Reist, S. Hausmann a R. Pienitz, “Physical and biological factors affecting mercury and perfluorinated contaminants in arctic char (Salvelinus alpinus) of Pingualuit Crater Lake (Nunavik, Canada) .”, Arctic 65, 195–206 (2012).
12 Pingualuit crater (chubb crater), https://www.wondermondo.com/pingualui t-crater-chubb-crater/, (accessed: 27.07.2018).
It was first isolated from lettuce (Lactuca sativa) by D. Siefermann- Harms, S. Hertzberg, G. Borch and S. Liaaen-Jensen in 1981.*
Studies in diabetic mice have shown the ability of this carotenoid to significantly lower blood sugar1.
Lettuce, from which lactucaxanthin was isolated, was first bred in ancient Egypt approximately 2,500 years BC. From that time, the images on the walls of the tombs are preserved. Lettuce further spread from Egypt through Greece and Rome not only to almost the whole Europe, but also to China, for example. It was first imported to America by Christopher Columbus during his second expedition to the New World in 1494. Today, there are countless cultivars of this plant. Among the most common there are romaine lettuce (Lactuca sativa var. longifolia) and looseleaf lettuce (Lactuca sativa var. capitata). Although it is one of the healthiest foods, when grown in greenhouse with a lack of light and at low temperatures, it accumulates nitrates. They can cause the so-called blue baby syndrome. A small portion of lettuce production is used to produce tobacco-free cigarettes2. In 2016, 26.8 million tons of lettuce were produced (together with chicory)3.
*Siefermann-Harms D., Hertzberg S., Borch G., Liaaen-Jensen S. Lactucaxanthin, an ε,ε-carotene-3,30-diol from Lactuca sativa. Phytochemistry, 20, 1, (1981) pp. 85-88.
1 S. S. Gopal , M. J. Lakshmi, G. Sharavana, G. Sathaiah, Y. N. Sreerama, V. Baskaran, Lactucaxanthin - a potential anti-diabetic carotenoid from lettuce (Lactuca sativa) inhibits α-amylase and α-glucosidase activity in vitro and in diabetic rats
2 S. H. Katz, W. W Weaver, Encyclopedia of Food and Culture: Food production to Nuts, Volume 2, Scribner, 2003, ISBN 0684805669, p. 614
3 Faostat, Faostat - Crops, http://www.fao.org/faostat/en/#data/QC (accessed: 20.07.2020).
It was first isolated from autumn leaves by Jöns Jacob Berzelius in 1837.*
The vast majority of the lutein production is now obtained from the flowers of the Mexican marigold (Tagetes erecta), the French marigold (Tagetes patula), or the pot marigold (Calendula officinalis), with the bulk of the production coming from China, India and Mexico1. In the commercial production of lutein, efforts are being made to produce it using algae. There have been quite successful experiments with Chlorella pyrenoidosa and Scenedesmus obliquus2. These efforts for a new approach are not surprising as the estimate of the global market with lutein was $225 milion in 20163.
The source of lutein for the human body is for example spinach, zucchini, kiwi, or egg yolk4. In the human body, it protects a part of the eye called macula against excessive exposure to blue light by absorbing it5, and it is also the major carotenoid in the brain. Some studies have shown that its amount in the blood and brain has an effect on cognitive functions6.
Among animals, lutein can be found for example in the larvae of the monarch butterfly (Danaus plexippus), on whose body it forms beautiful yellow stripes7.
*Berzelius J. J. Ueber die gelbe Farbe der Blaetter im Herbste. Annalen der Pharmacie, 21, (1837) pp. 257–262.
1 J.-H. Lin, D.-J. Lee a J.-S. Chang, “Lutein production from biomass: marigold flowers versus microalgae.”, Bioresource Technology 184, 421–428 (2015).
2 J.-H. Lin, D.-J. Lee a J.-S. Chang, “Lutein in specific marigold flowers and microalgae.”, Journal of the Taiwan Institute of Chemical Engineers 49, 90–94 (2015).
3 A. M. Williams, “The global market for carotenoids.”, BCC Research Report Overview, – (2018).
4 O. Sommerburg, J. E. E. Keunen, A. C. Bird a F. J. G. M. van Kuijk, “Fruits and vegetables that are sources for lutein and zeaxanthin: the macular pigment in human eyes.”, British Journal of Ophthalmology 82, 907–910 (1998).
5 J. T. Landrum a R. A. Bone, “Lutein, zeaxanthin, and the macular pigment.”, Archives of Biochemistry and Biophysics 385, 28–40 (2001).
6 E. J. Johnson, R. Vishwanathan, M. A. Johnson, D. B. Hausman, A. Davey, T. M. Scott, R. C. Green, L. S. Miller, M. Gearing, J. Woodard, P. T. Nelson, H.-Y. Chung, W. Schalch, J. Wittwer a L. W. Poon, “Relationship between serum and brain carotenoids, -tocopherol, and retinol concentrations and cognitive performance in the oldest old from the Georgia centenarian study.”, Journal of Aging Research 2013 (2013) https: //doi.org/10.1155/2013/951786.
7 J. T. Landrum, Carotenoids: physical, chemical, and biological functions and properties (CRC Press, 2009).
It was first isolated from the berries of black bryony (Tamus communis L.) by Hartsen in 1873.*
Although it was first isolated already in 18731, it got its current name (or at least a similar one – lycopine) as late as in 1903 from Schunck2, after Millardet named it solanorubin in 18751.
Except tomatoes, lycopene also occurs in larger amounts in watermelon, pink grapefruit, apricots, pink guavas, or pumpkins1,3,4. For its better absorption, tomatoes should better be heat-treated but not fried3–5. The content of lycopene is higher in already processed foods (for example ketchup), as the content of other components, such as water, is reduced3,4. In the human body, it is the main carotenoid in blood plasma but it also occurs in larger amounts in testicles, adrenal glands and prostate6. Unlike some other carotenoids, it is not a precursor of vitamin A5. Some studies suggest that lycopene (or foods containing it) could be a useful substance in prevention of certain types of cancer (e.g. prostate cancer) or cardiovascular diseases1. Such studies, however, need further evidence.
*Hartsen, Chemistry Centre, 204, (1873).
1 P. Singh a G. K. Goyal, “Dietary lycopene: Its properties and anticarcinogenic effects.”, Comprehensive Reviews in Food Science and Food Safety 7, 255–270 (2008).
2 C. A. Schunck, “The xanthophyll group of yellow colouring matters.”, Proceedings of the Royal Society of London 72, 165–176 (1903).
3 A. Dasgupta a K. Klein, Antioxidants in food, vitamins and supplements (Elsevier, 2014).
4 R. Watson a B. Dokken, Glucose intake and utilization in pre-diabetes and diabetes (Academic Press, 2014).
5 E. N. Story, R. E. Kopec, S. J. Schwartz a G. K. Harris, “An update on the health effects of tomato lycopene.”, Annual Review of Food Science and Technology 1, 189–210 (2010).
6 P. M. Choksi a V. Y. Joshi, “A review on lycopene — extraction, purification, stability and applications.”, International Journal of Food Properties 10, 289–298 (2007).
It was first isolated from seep monkeyflower (Mimulus guttatus) by H. Nitsche in 1972.*
In addition to several other plants belonging to the genus Mimulus, mimulaxanthin has been discovered in only one other plant up to this day, namely in the yellow archangel (Galeobdolon luteum)1,2. To obtain literally a pinch of mimulaxanthin, a huge amount of flowers had to be collected. Apart from other carotenoids, 150 mg of mimulaxanthin was extracted from 3 kg of flowers of seep monkeyflower3 , and 36 mg of mimulaxanthin was obtained from 1.4 kg of flowers of yellow archangel2.
The seep monkeyflower is native to North America. It was introduced in Europe (and also the Czech Republic) as a garden flower and it escaped from gardens into the wild4. The extract from the flower of this plant is used in so-called Bach flower remedies against anxiety and fear5,6. However, the effectiveness of this therapy has never been proven and the method is subject to harsh criticism7,8.
The yellow archangel is a close relative to dead-nettles (Lamium) and contains similar medicinal substances. It is recommended as a medicinal plant for internal infections, such as kidney infection. It will also help against varicose veins or rashes. It can be used as tea, bandage, or sitz baths9. The yellow archangel belongs to myrmecochorous plants (their seeds are dispersed by ants)10.
*Nitsche H. Mimulaxanthin—a new allenic xanthophyll from the petals of Mimulus guttatus. Phytochemistry, 11, 1, (1972) pp. 401-404.
1 A. M. LaFountain, H. A. Frank a Y.-W. Yuan, “Carotenoid composition of the flowers of Mimulus lewisii and related species: Implications regarding the prevalence and origin of two unique, allenic pigments.”, Archives of Biochemistry and Biophysics 573, 32–39 (2015).
2 R. Buchecker a C. H. Eugster, “Mimulaxanthin, Hauptcarotinoid von Lamium montanum, und seine absolute Konfiguration; konfigurative Verknüpfung von Deepoxyneoxanthin mit Neoxanthin .”, Helvetica Chimica Acta 63, 2531–2537 (1980).
3 H. Nitsche, “Die Struktur von Mimulaxanthin.”, Zeitschrift für Naturforschung 28c, 481–487 (1973).
4 Jindřich Houska, Erythranthe guttata (dc.) g. l. nesom – kejklířka skvrnitá / čarodejka škvrnitá, https : / / botany . cz / cs / mimulus - guttatus/, (accessed: 06.08.2018).
5 B. Cornelia a C. R. Boedler, Applying bach flower therapy to the healing profession of homoeopathy (B. Jain Publishers, 2003).
6 J. Howard, “Do Bach flower remedies have a role to play in pain control?: A critical analysis investigating therapeutic value beyond the placebo effect, and the potential of Bach flower remedies as a psychological method of pain relief.”, Complementary Therapies in Clinical Practice 13, 174–183 (2007).
7 K. Thaler, A. Kaminski, A. Chapman, T. Langley a G. Gartlehner, “Bach Flower Remedies for psychological problems and pain: a systematic review.”, BMC Complementary and Alternative Medicine 9 (2009) https: //doi.org/10.1186/1472-6882-9-16.
8 E. Ernst, “Bach flower remedies: a systematic review of randomised clinical trials.”, Swiss Medical Weekly 140 (2010) https://doi.org/10.4414/smw. 2010.13079.
9 Ivo Antušek, Pitulník žlutý Galeobdolon luteum huds. https://www.bioli b.cz/cz/taxon/id41052/, (accessed: 06.08.2018).
10 A. Orczewska, “Migration of herbaceous woodland flora into post-agricultural black alder woods planted on wet and fertile habitats in south western Poland.”, Plant Ecology 204, 83–96 (2009).
It was first isolated from green leaves of barley (Hordeum sp.) by H. H. Strain in 1938.*
Together with β-carotene, lutein and violaxanthin, neoxanthin forms the majority of carotenoids in the green leaves of plants1 and it is the main carotenoid in leaf vegetables (spinach, lettuce, etc.)2. In addition, neoxanthin is a predominant carotenoid in many algae1. Its importance for plants was proven by the creation of genetically modified plant of the thale cress (Arabidopsis thaliana), in which the possibility of neoxanthin production was blocked but it could produce other carotenoids natural to it. Individuals with this modification were more sensitive to photooxidative stress which manifested itself for example in faster whitening of the leaf in more intense light3.
Barley, from which neoxanthin was first isolated, is a very important crop (it is the fourth most widespread cereal in the world after wheat, rice and maize)4. It is used as fodder, for the production of flour, or malt. In order to simplify beer brewing, species of barley containing lower amounts of β-glucan were bred5. However, later it was found that this substance has beneficial effects on human health (e.g. reduces the amount of cholesterol in the blood)6,7. Today, scientist are going against the brewing trend and are trying to increase the β-glucan content in barley8.
*H. Strain H. H. Leaf Xanthophylls. Carnegie Institute Publ. No. 490, Washington (1938).
1 G. Britton, S. Liaaen-Jensen a H. Pfander, Carotenoids: handbook (Springer Science & Business Media, 2004).
2 U. S. Gupta, What’s new about crop plants: novel discoveries of the 21st century (CRC Press, 2011).
3 L. Dall’Osto, S. Cazzaniga, H. North, A. Marion-Poll a R. Bassi, “The Arabidopsis aba4-1 mutant reveals a specific function for neoxanthin in protection against photooxidative stress.”, The Plant Cell 19, 1048–1064 (2007).
4 The Food and Agriculture Organization of the United Nations, Faostat: crops, http://www.fao.org/faostat/en/#data/QC, (accessed: 02.08.2018).
5 R. B. Vis a K. Lorenz, “Malting and brewing with a high β-glucan barley.”, LWT - Food Science and Technology 31, 20–26 (1998).
6 D. J. A. Jenkins, M. Axelsen, C. W. C. Kendall, L. S. A. Augustin, V. Vuksan a U. Smith, “Dietary fibre, lente carbohydrates and the insulinresistant diseases.”, British Journal of Nutrition 83, S157–S163 (2000).
7 A. Cavallero, S. Empilli, F. Brighenti a A. M. Stanca, “High (1->3,1->4)- β-glucan barley fractions in bread making and their effects on human glycemic response.”, Journal of Cereal Science 36, 59–66 (2002).
8 E. Islamovic, D. E. Obert, R. E. Oliver, S. A. Harrison, A. Ibrahim, J. M. Marshall, K. J. Miclaus, G. Hu a E. W. Jackson, “Genetic dissection of grain beta-glucan and amylose content in barley (Hordeum vulgare L.).”, Molecular Breeding 31, 15–25 (2013).
It was first isolated from the red bread mold Neurospora crassa by F. Haxo in 1949.*
Neurosporene occurs in many organisms as an intermediate product in the formation of other carotenoids. We can therefore find it in plants, bacteria, or fungi1. It is important for organisms in terms of its antioxidative effects and protection against UV-B radiation2.
It is one of about 20 carotenoids found in human blood and tissues, and one of 12 found in blood plasma3. Its commercial production has still not been achieved, therefore the most important source for the human body is food that contains it 4,5.
The main source of neurosporene for scientific purposes is the strain Rhodobacter capsulatus, either genetically modified6, or growing in the presence of nicotine7, or Rhodobacter viridis with a neurosporene content of up to 98%4. Another possibility is genetically modified Escherichia coli8.
The genus Neurospora was described already in 1843, in a rather unflattering circumstances. In Paris, it caused the mould of bread in the hot and humid summer9. Many things has changed since then and today it is one of the most widely used model organisms, mainly in molecular biology and genetics10.
*Haxo F. Studies on the Carotenoid Pigments of Neurospora; Composition of the Pigment. Arch. Biochem. 20, 2, (1949) pp. 400-421.
1 G. Britton, S. Liaaen-Jensen a H. Pfander, Carotenoids: handbook (Springer Science & Business Media, 2004).
2 G. Sandmann, S. Kuhn a P. Böger, “Evaluation of structurally different carotenoids in Escherichia coli transformants as protectants against UVB radiation.”, Applied and Environmental Microbiology 64, 1972–1974 (1998).
3 J. Fiedor a K. Burda, “Potential role of carotenoids as antioxidants in human health and disease.”, Nutrients 6, 466–488 (2014).
4 E. V. V. Ramaprasad, C. Sasikala a C. V. Ramana, “Neurosporene is the major carotenoid accumulated by Rhodobacter viridis JA737.”, Biotechnology Letters 35, 1093–1097 (2013).
5 F. Khachik, “Distribution and metabolism of dietary carotenoids in humans as a criterion for development of nutritional supplements.”, Pure and Applied Chemistry 78, 1551–1557 (2006).
6 P. A. Scolnik, M. A. Walker a B. L. Marrs, “Biosynthesis of carotenoids derived from neurosporene in Rhodopseudomonas capsulata*.”, The Journal of Biological Chemistry 255, 2427–2432 (1980).
7 R. K. Singh, A. Ben-Aziz, G. Britton a T. W. Goodwin, “Biosynthesis of spheroidene and hydroxyspheroidene in Rhodopseudomonas species: experiments with nicotine as inhibitor (Short Communication).”, Biochemical Journal 132, 649–652 (1973).
8 J. Harada, K. V. P. Nagashima, S. Takaichi, N. Misawa, K. Matsuura a K. Shimada, “Phytoene desaturase, CrtI, of the purple photosynthetic bacterium, Rubrivivax gelatinosus, produces both neurosporene and lycopene.”, Plant and Cell Physiology 42, 1112–1118 (2001).
9 D. D. Perkins, “ Neurospora: the organism behind the molecular revolution.”, Genetics 130, 687–701 (1992).
10 R. H. Davis a D. D. Perkins, “ Neurospora: a model of model microbes.”, Nature Reviews Genetics 3, 397–403 (2002).
It was first isolated from scarlet elf cup (Plectania coccinea) by N. Arpin and S. Liaaen-Jensen in 1967.*
This carotenoid was named after the genus name of the fungus Plectania coccinea. However, the fungus was later given its current name Sarcoscypha coccinea, where Sarcoscypha means a “fleshy cup” and coccinea refers to the bright red colour1. The scarlet elf cup grows also in the Czech Republic but opinions on its edibility differ. One can enjoy its beauty in the spring when it grows on the rotting wood of deciduous trees1,2. It is food for both rodents, and snails3.
Plectaniaxanthin is one of the less explored carotenoids. In addition to the above mentioned scarlet elf cup, it was also found for example in yeasts of the species Cryptococcus laurentii4, and in Dioszegia sp. In the latter, exposition of the yeast to oxidative stress increased the proportion of plectaniaxanthin. In this procedure, the yeasts are supplied with more oxygen leading to the creation of plectaniaxanthin which should protect the organism against oxygen5.
*Arpin N., Liaaen Jensen S. Recherches chimiotaxinomiques sur les champignons. Fungal carotenoids: III—Nouveaux carotenoides, notamment sous forme d’esters tertiaires, isoles de Plectania coccinea (scop. ex fr.) fuck. Phytochemistry, 6, 7, (1967) pp. 995-1005.
1 A. H. Smith a N. S.Weber, The mushroom hunter’s field guide, Mushroom Field Guides (University of Michigan Press, 1980).
2 Vladimír Klepáč, Česku vládne mráz a sníh, ale lesy jsou plné hub, https: //www.novinky.cz/domaci/427121- cesku- vladne- mraz- a- snih- ale- lesyjsou- plne-hub.html, (accessed: 26.09.2018).
3 R. P. Brown, “Observations on Sarcoscypha coccinea and Disciotis venosa in North Wales during 1978–1979.”, Bulletin of the British Mycological Society 14, 130–135 (1980).
4 M. Bae, T. H. Lee, H. Yokoyama, H. G. Boettger a C. O. Chichester, “The occurrence of plectaniaxanthin in Cryptococcus laurentii.”, Phytochemistry 10, 625–629 (1971).
5 A. Madhour, H. Anke, A. Mucci, P. Davoli a R. W. S. Weber, “Biosynthesis of the xanthophyll plectaniaxanthin as a stress response in the red yeast Dioszegia (Tremellales, Heterobasidiomycetes, Fungi).”, Phytochemistry 66, 2617–2626 (2005).
It was first isolated from sweetbriar rose (Rosa rubiginosa) by R. Kuhn and Ch. Grundmann in 1934.*
Rubixanthin is one of the main carotenoids in the fruits of sweetbriar rose, the so-called rose hips1. The amount of the carotenoid varies depending on the ripeness of the fruit2. Rubixanthin and its isomer gazaniaxanthin are present in almost all specimens of roses. Neither rubixanthin, nor gazaniaxanthin are precursors of vitamin A. However, in other branches of industry they may be used as antioxidants or dyes1.
Some bird species obtain rubixanthin by consumption of food containing it, including rose hips. Rubixanthin is then converted to metabolites such as 4-oxo-rubixanthin in their bodies3. Together with other substances, it colours the bird’s feathers in a beautiful red colour, as for example in scarlet finch (Haematospiza sipahi), two-barred crossbill (Loxia leucoptera) or arctic redpoll (Acanthis hornemanni)4,5. The colour of the feathers in for example house finch (Haemorhous mexicanus) is decisive when choosing partner. Males must therefore try to ensure that their diet contains an adequate amount of carotenoids6,7.
Rubixanthin is used to colour cosmetics, and is marked on the packing as E161d (or natural yellow 27)8. Food colouring with rubixanthin is not permitted in the EU9,10.
*Kuhn R., Grundmann Ch. Über Rubixanthin, ein neues Xanthophyll der Formel C40H56O. Ber. dtsch. Chem. Ges. A/B, 67, (1934) pp. 339–344.
1 D. Hornero-Méndez a M. I. Mínguez-Mosquera, “Carotenoid pigments in Rosa mosqueta hips, an alternative carotenoid source for foods.”, Journal of Agricultural and Food Chemistry 48, 825–828 (2000).
2 S. C.Andersson, K. Rumpunen, E. Johansson a M. E.Olsson, “Carotenoid content and composition in rose hips (Rosa spp.) during ripening, determination of suitable maturity marker and implications for health promoting food products.”, Food Chemistry 128, 689–696 (2011).
3 G. E. Hill a K. J. McGraw, Bird coloration: mechanisms and measurements (Harvard University Press, 2006).
4 R. A. Ligon, R. K. Simpson, N. A. Mason, G. E. Hill a K. J. McGraw, “Evolutionary innovation and diversification of carotenoid-based pigmentation in finches.”, Evolution 70, 2839–2852 (2016).
5 P. Deviche, K. J. McGraw a J. Underwood, “Season-, sex-, and age-specific accumulation of plasma carotenoid pigments in free-ranging white-winged crossbills Loxia leucoptera.”, Journal of Avian Biology 39, 283–292 (2008).
6 C. Y. Inouye, G. E. Hill, R. D. Stradi a R. Montgomerie, “Carotenoid pigments in male house finch plumage in relation to age, subspecies, and ornamental coloration.”, The American Ornithologists’ Union 118, 900– 915 (2001).
7 K. J. McGraw, P. M. Nolan a O. L. Crino, “Carotenoid accumulation strategies for becoming a colourful House Finch: analyses of plasma and liver pigments in wild moulting birds.”, Functional Ecology 20, 678–688 (2006).
8 A. C. de Groot, J. W. Weyland a J. P. Nater, Unwanted effects of cosmetics and drugs used in dermatology, vydání 282 (Elsevier, 1994).
9 FÉR potravina, E161d - rubixantin, https://www.ferpotravina.cz/seznamecek/ E161d, (accessed: 13.08.2018).
10 T. Vrbová, Víme, co jíme?, aneb, průvodce éčky v potravinách (EcoHouse, 2001).
It was first isolated from the peel of the Citrus tangerina species, a close relative of mandarin orange, by A. L. Curl in 1962.*
For his experiments, A. L. Curl bought three batches of tangerines on different days around the New Year, and he obtained 99.5, 1215 and 1714 grams of peel, respectively. Tangeraxanthin was present in only two of them, those purchased before the end of the year. In addition to this carotenoid, another less common carotenoid – reticulataxanthin – was present in the peel1.
Tangerine got its name after the Moroccan port city Tangier. Supposedly, the first shipment of tangerines was sent to Europe in the mid-1740s from there2. Tangerine is one of the cultivars of mandarin and they are often confused in everyday life. Mandarins come from China where the tradition of their breeding dates back to 4,000 years ago3. Its name probably originated from comparing its colour to the colour of the dress of state dignitaries in China (Mandarins)2. The first tree was imported to Europe, namely England, as late as in 1805, and it spread to Malta, Sicily and Italy from there4.
*Curl A. L. Reticulataxanthin and Tangeraxanthin, Two Carbonyl Carotenoids from Tangerine Peel. Journal of Food Science, 27 (1962) pp. 537–543.
1 A. L. Curl, “Reticulataxanthin and tangeraxanthin, two carbonyl carotenoids from tangerine peel.”, Journal of Food Science 27, 537–543 (1962).
2 D. Reeve a D. Arthur, “Riding the citrus trail: When is a mandarin a tangerine?.”, Perfumer & Flavorist 27, 20–22 (2002).
3 I. A. Khan, Citrus genetics, breeding and biotechnology, CABI Publishing Series (CABI, 2007).
4 S. Tolkowsky, Hesperides: a history of the culture and use of citrus fruits (J. Bale, Sons & Curnow, Limited, 1938).
It was first isolated from the common dandelion (Taraxacum officinale) by R. Kuhn and E. Lederer in 1931.*
In their paper from 1931, Kuhn and Lederer explained that taraxaxanthin would be a more accurate name for this carotenoid. At the same time, however, they admitted that it was more convenient to use an abbreviated name, taraxanthin1. In addition to common dandelion, one of the main sources of taraxanthin include beautifully yellow-flowering plants such as the common sunflower (Helianthus annuus), tall buttercup (Ranunculus aceracris), touch-me-not balsam (Impatiens noli-tangere), common broom (Sarothamnus Cytisus scoparius) and coltsfoot (Tussilago farfara)2. The latter is one of the classical medicinal plants – tea from its flowers is used mainly against cough3. Its genus name refers to this fact, because tussis means cough and ago means to cure, or to act upon something4. In long-term use, it is dangerous for the human body, and therefore it may not be used in food production according to the Decree No. 225/2008 Coll.3,5.
Taraxanthin is also commonly found in fish tissues6–8 and in small quantities it is also part of the fodder for captive fish9.
A study from 2001 showed that the human body neither absorbs taraxanthin to blood plasma, nor produces its metabolites from it10.
*Kuhn R., Lederer E. Taraxanthin, ein neues Xanthophyll mit 4 Sauerstoffatomen. Hoppe-Seyler‘s Zeitschrift für physiologische Chemie, 200, 1-3, (1931) pp. 108–114.
1 R. Kuhn a E. Lederer, “Taraxanthin, ein neues Xanthophyll mit 4 Sauerstoffatomen.”, Hoppe-Seyler’s Zeitschrift für physiologische Chemie 200, 108–114 (1931).
2 K. Egger, “Zur Identität von Taraxanthin und Luteinepoxid.”, Planta 80, 65–76 (1968).
3 Petr Krása, Tussilago farfara l. – podběl lékařský / podbel liečivý, https: //botany.cz/cs/tussilago-farfara/, (accessed: 07.08.2018).
4 D. Booth, An analytical dictionary of the english language (Oxfordská univerzita, 1835).
5 Zákony pro lidi, Vyhláška č. 225/2008 sb. https://www.zakonyprolidi.cz/ cs/2008-225, (accessed: 07.08.2018).
6 T. Goodwin, The biochemistry of the carotenoids: volume 2 animals (Springer Science & Business Media, 2012).
7 C. C. C. R. de Carvalho a M. J. Caramujo, “Carotenoids in aquatic ecosystems and aquaculture: A colorful business with implications for human health.”, Frontiers in Marine Science 4, 93–106 (2017).
8 D. A. Davis, Feed and feeding practices in aquaculture, Woodhead Publishing Series in Food Science, Technology and Nutrition (Woodhead Publishing, 2015).
9 S. H. S. Dananjaya, D. M. S. Munasinghe, H. B. S. Ariyaratne, J. Lee a M. D. Zoysa, “Natural bixin as a potential carotenoid for enhancing pigmentation and colour in goldfish (Carassius auratus).”, Aquaculture Nutrition 23, 255–263 (2017).
10 170A. B. Barua a J. A. Olson, “Xanthophyll epoxides, unlike β-carotene monoepoxides, are not detectibly absorbed by humans.”, The Journal of Nutrition 131, 3212–3215 (2001).
It was first isolated from honeysuckles (Lonicera webbiana and Lonicera ruprechtiana) by A.-K. Rahman and K. Egger in 1973.*
In addition to webbiaxanthin, another new carotenoid was discovered by A.-K. Rahman and K. Egger in 1973 in the two species of honeysuckle (Lonicera webbiana and Lonicera ruprechtiana), which was named loniceraxanthin after the Latin genus name of honeysuckle1.
Lonicera webbiana and Lonicera ruprechtiana are shrubs growing for example in Pakistan or China2. In total, there are about 180 species of honeysuckles that grow virtually all around the Northern hemisphere3. These shrubs got their Latin genus name in honour of the German botanist Adam Lonicer4. Most of the honeysuckle species have poisonous berries, there are some exceptions though, such as blue honeysuckle (Lonicera kamtschatica), whose berries are sold under the name Kamchatka blueberry. It contains a large amount of vitamin C and other antioxidants5,6. Other honeysuckle species are mostly planted as ornamental plants.
Japanese honeysuckle (Lonicera japonica) is used in small doses in traditional Chinese medicine. However, it is toxic in larger quantities or with long-term use, and must not be used in the treatment of children. It is possible to use buds, leaves and young twigs. Despite these beneficial properties, this species is invasive in many countries of the world7.
*Rahman A.-K., Egger K. Ketocarotinoide in den Früchten von Lonicera webbiana und Lonicera ruprechtiana. Z. Naturforsch. 28 c, (1973) pp. 434-436.
1 A.-K. Rahman a K. Egger, “Ketocarotinoide in den Früchten von Lonicera webbiana und Lonicera ruprechtiana.”, Zeitschrift für Naturforschung C 28c, 434–436 (1973).
2 Roman Businský, Pákistán, národní park ayubia, https://botany.cz/cs/ ayubia/, (accessed: 08.08.2018).
3 G. E. Burrows a R. J. Tyrl, Toxic plants of north america (John Wiley & Sons, 2012).
4 Jana Möllerová, Lonitzer, adam, https://botany.cz/cs/lonitzer/, (accessed: 08.08.2018).
5 Jana Möllerová, Lonicera caerulea l. – zimolez modrý / zemolez belasý, https://botany.cz/cs/lonicera-caerulea/, (accessed: 08.08.2018).
6 T. Pokorná-Juríková a J. Matuškovic, “The study of irrigation influence on nutritional value of Lonicera kamtschatica - Cultivar Gerda 25 and Lonicera edulis berries under the Nitra conditions during 2001-2003.”, Horticultural Science 34, 11–16 (2007).
7 Věra Svobodová, Lonicera japonica thunb. – zimolez japonský / zemolez, https://botany.cz/cs/lonicera-japonica/, (accessed: 08.08.2018).
It was first isolated from corn (Zea sp.) by P. Karrer, H. Salomon and H. Wehrli in 1929.*
Zeaxanthin occurs naturally in egg yolk, corn, orange pepper, mango, or oranges1. In the human body, it can be found in the highest concentrations in eye, namely in the centre of the macula lutea where it plays an important role2. Together with two other carotenoids, lutein and meso-zeaxanthin, an isomer of zeaxanthin, it protects the cells by absorbing part of the blue light3. Some studies suggest that zeaxanthin together with lutein could play a role in the prevention of two diseases of the eye, specifically cataract and macular degeneration, which mainly affect elderly3–5.
In green plants, zeaxanthin takes part mainly in the xanthophyll cycle where it serves as a quench in excessive light. It is also the starting molecule in the formation of picrocrocin and safranal, substances responsible for taste and smell of saffron6. The European Commission has approved the use of synthetic zeaxanthin as a food ingredient with a maximum daily intake of 2 mg7. It is marked on the packing as E161h.
*Karrer P., Salomon H., Wehrli H. Pflanzenfarbstoffe XIV. Über einen Carotinoidfarbstoff aus Mais: Zeaxanthin (1. Mitteilung). HCA, 12, (1929) pp. 790–792.
1 O. Sommerburg, J. E. E. Keunen, A. C. Bird a F. J. G. M. van Kuijk, “Fruits and vegetables that are sources for lutein and zeaxanthin: the macular pigment in human eyes.”, British Journal of Ophthalmology 82, 907–910 (1998).
2 R. A. Bone, J. T. Landrum, L. M. Friedes, C. M. Gomez, M. D. Kilburn, E. Menendez, I. Vidal a W. Wang, “Distribution of lutein and zeaxanthin stereoisomers in the human retina.”, Experimental Eye Research 64, 211– 218 (1997).
3 N. I. Krinsky, J. T. Landrum a R. A. Bone, “Biologic mechanisms of the protective role of lutein and zeaxanthin in the eye.”, Annual Review of Nutrition 23, 171–201 (2003).
4 S. Maci a R. Santos, “The beneficial role of lutein and zeaxanthin in cataracts.”, Nutrafoods 14, 63–69 (2015).
5 J. A. Mares-Perlman, A. E. Millen, T. L. Ficek a S. E. Hankinson, “The body of evidence to support a protective role for lutein and zeaxanthin in delaying chronic disease. Overview.”, The Journal of Nutrition 132, 518S– 524S (2002).
6 S. Frusciante, G. Diretto, M. Bruno, P. Ferrante, M. Pietrella, A. Prado- Cabrero, A. Rubio-Moraga, P. Beyer, L. Gomez-Gomez, S. Al-Babili a G. Giuliano, “Novel carotenoid cleavage dioxygenase catalyzes the first dedicated step in saffron crocin biosynthesis.”, Proceedings of the National Academy of Sciences of the United States of America 11, 12246–12251 (2014).
7 “Prováděcí rozhodnutí komise ze dne 22. ledna 2013, kterým se povoluje uvedení syntetického zeaxanthinu na trh jako nové složky potravin podle nařízení Evropského parlamentu a Rady (ES) c. 258/97.”, Úřední věstník Evropské unie, – (2013).
It was first isolated from the groundcherry (Physalis sp.) by R. Kuhn and Ch. Grundmann in 1933.*
The main source of β-cryptoxanthin in the diet is orange fruit such as papaya, orange, tangerine, apricot, red pepper or peach. It is one of approximately 20 carotenoids found in human tissues and blood, where it makes up about 90% of the carotenoids present together with β-carotene, lycopene, lutein and α-carotene1,2. In the human body, the main role of β-cryptoxanthin is its conversion to vitamin A3. β-cryptoxanthin is marked on the packing as E161c and although its negative effect on human health is not known, it has not been authorized to use for food colouring yet4,5.
β-cryptoxanthin has been studied for possible effects in the prevention and treatment of cancer. Some studies have found positive effects6, 7, other studies found negative effects8.
Chinese lantern (Physalis alkekengi), from which β-cryptoxanthin was first isolated, is often planted as an ornamental plant in gardens. It easily escapes from there and thus it has spread throughout almost all Europe (it is said that it was spread by nomadic Romani people). The fruits of the groundcherry are used in dried flower arrangements, but in small quantities they can also be used in alternative medicine. One must be especially careful about unripe fruits which are poisonous9.
*Kuhn R., Grundmann Ch. Über Krypto-xanthin, ein Xanthophyll der Formel C40H36O (Über das Vitamin des Wachstums, V. Mitteil.). Ber. dtsch. Chem. Ges. A/B, 66 (1933) pp. 1746–1750.
1 D. E. Breithaupt, P. Weller, M. Wolters a A. Hahn, “Plasma response to a single dose of dietary β-cryptoxanthin esters from papaya (Carica papaya L.) or non-esterified β-cryptoxanthin in adult human subjects: a comparative study.”, British Journal of Nutrition 90, 795–801 (2003).
2 J. G. Bieri, E. D. Brown a J. C. Smith Jr., “Determination of individual carotenoids in human plasma by high performance liquid chromatography.”, Journal of Liquid Chromatography 8, 473–484 (1985).
3 B. J. Burri, “Beta-cryptoxanthin as a source of vitamin A.”, Journal of the Science of Food and Agriculture 95, 1786–1794 (2015).
4 FÉR potravina, E161c - kryptoxantin, https : / / www . ferpotravina . cz / seznam-ecek/E161c, (accessed: 06.08.2018).
5 T. Vrbová, Víme, co jíme?, aneb, průvodce éčky v potravinách (EcoHouse, 2001).
6 J.-M. Yuan, D. O. Stram, K. Arakawa, H.-P. Lee a M. C. Yu, “Dietary cryptoxanthin and reduced risk of lung cancer.”, Cancer Epidemiology, Biomarkers & Prevention 12, 890–898 (2003).
7 F. Lian, K. Hu, R. M. Russell a X. Wang, “β-Cryptoxanthin suppresses the growth of immortalized human bronchial epithelial cells and non-small-cell lung cancer cells and up-regulates retinoic acid receptor β expression.”, International Journal of Cancer 119, 2084–2089 (2006).
8 G. N. DeLorenze, L. McCoy, A.-L. Tsai, C. P. Quesenberry Jr., T. Rice, D. Il’yasova a M. Wrensch, “Daily intake of antioxidants in relation to survival among adult patients diagnosed with malignant glioma.”, BMC Cancer 10 (2010) https://doi.org/10.1186/1471-2407-10-215.
9 Ladislav Kovář, Physalis alkekengi l. – mochyně židovská / machovka čerešňová, https://botany.cz/cs/physalis-alkekengi/, (accessed: 06.08.2018).