Ubiquinone-10

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Structural formula
Structural formula of ubiquinone-10
General
Surname Ubiquinone-10
other names
  • 6-all- trans -decaprenyl-2,3-dimethoxy-5-methyl-1,4-benzoquinone ( IUPAC / IUBMB )
  • Q-10
  • outdated: Coenzyme Q 10
Molecular formula C 59 H 90 O 4
Brief description

odorless solid

External identifiers / databases
CAS number 303-98-0
EC number 206-147-9
ECHA InfoCard 100.005.590
PubChem 5281915
ChemSpider 4445197
DrugBank DB09270
Wikidata Q321285
Drug information
ATC code

C01 EB09

properties
Molar mass 863.34 g mol −1
Physical state

firmly

Melting point

48-52 ° C

solubility
  • soluble in chloroform
  • practically insoluble in water
safety instructions
Please note the exemption from the labeling requirement for drugs, medical devices, cosmetics, food and animal feed
GHS labeling of hazardous substances
no GHS pictograms
H and P phrases H: no H-phrases
P: no P-phrases
As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Coenzyme Q10 (also UQ of Engl. Ubiquinone , or Q-10 or Coenzyme Q 10 ) is a quinone derivative having a lipophilic isoprenoid side chain, structurally related to vitamin K and vitamin E . The reduced, phenolic form is called ubihydroquinone or ubiquinol (QH 2 for short ). Ubiquinon-10 is one of the ubiquinones .

Q-10 is an electron and proton carrier between complex I or complex II and complex III of the respiratory chain .

Q-10 is offered for sale as an ingredient in cosmetic creams and as a dietary supplement .

properties

Q-10 is a yellow-orange, crystalline powder with no odor or taste. The hydrophobic isoprenoid side chain enables the molecule to be anchored in the likewise hydrophobic area of ​​the biomembrane , which builds up the mitochondria .

Biological function

Q-10 is an endogenous substance. It is partly absorbed through food , but it is also produced in the body itself. In every human cell , the energy from food is converted into the body's own energy ( ATP ). As a coenzyme, Q-10 is involved in oxidative phosphorylation , which generates 95% of total body energy (ATP). The organs with the highest energy requirements - such as the heart , lungs and liver - therefore also have the highest Q-10 concentration.

biochemistry

The respiratory chain in the mitochondria of the cell enables the gradual transfer of electrons and protons to oxygen while at the same time obtaining ATP as a biochemical energy equivalent. This reaction takes place on localized membrane proteins, complexes I to V, and mobile components, ubiquinone and cytochrome c . The latter serve as shuttle systems between the complexes: Ubiquinone mediates between complexes I / II and III, cytochrome c between complexes III and IV.

The electrons for the reduction of ubiquinone come from the oxidation of NADH on complex I of the respiratory chain , the NADH dehydrogenase , or from the oxidation of succinate on complex II, which is identical to the succinate dehydrogenase of the citric acid cycle . An ubiquinone molecule can take up two electrons step by step. In the first step QH forms • , a fairly stable semiquinone - radical . The uptake of the second electron creates the hydroquinone ubiquinol after protonation , i.e. the reduced form. In addition to electron transport, this also enables two protons to bind - ubiquinone can thus also serve as a proton carrier. These processes are important within the respiratory chain in the Q cycle at complex III .

Prooxidant and antioxidant properties

Ubiquinone is also involved in the formation of reactive oxygen species (ROS) through the creation of superoxide by ubi semiquinone - radicals that cause oxidative damage that underlies many degenerative diseases. Paradoxically, the ubiquinone pool is also an important mitochondrial antioxidant .

defect

Permanent Q-10 deficiency is rare. It is often found in patients with myopathies . Since not all of the enzymes involved in the biosynthesis of Q-10 are known, it is quite possible that mutations in one of the affected genes have not yet been identified.

One possibility for temporary Q-10 deficiency is medication with statins , where the inhibition of HMG-CoA reductase reduces the starting materials for the biosynthesis of Q-10, which leads to a decrease in plasma levels. On the other hand, nothing is known about the availability of Q-10 in muscles, nor about the effectiveness of increased intake.

biosynthesis

The biosynthesis of Q-10 in eukaryotes starts from 4-hydroxybenzoic acid , which is obtained from the amino acid tyrosine in five steps, including hydroxyphenylsuccinic acid and 4-coumaric acid , and forms the quinone part; on the other hand, all- trans -decaprenyl phosphate is required for the side chain , which is built up from geranylgeranyl phosphate (GGP, from the mevalonate pathway ) in six steps. Both starting materials are combined to 3-decaprenyl-4-hydroxybenzoate with the help of p-hydroxybenzoate polyprenyltransferase ( EC  2.5.1.39 ). In seven further steps, ubiquinol-10 is produced , which becomes ubiquinone-10 through electron transfer.

Nutritional supplement

A person ingests around three to five milligrams of the coenzyme daily through food, which is not absolutely necessary. In rare cases of increased Q-10 requirement, nutritional supplements can help avoid or compensate for a deficiency. For an adult, the dosage of Q-10 recommended by most scientists in such a case is 30–200 mg per day as a dietary supplement. The Federal Office for Consumer Protection and Food Safety has decreed that in Germany food supplements in capsule form with Q-10 may only be placed on the market if "the daily consumption of 100 mg coenzyme Q10 is not exceeded with a recommended consumption of one capsule per day" and the Labeling warns against consumption by pregnant and breastfeeding women, children and adolescents under 18 years of age.

Cosmetics

Q-10 is also a promoted active ingredient in skin creams that are widely available . They are supposed to compensate for the supposedly increasing lack of Q-10 with old age. B. ensure the breakdown of harmful radicals.

Occurrence

Q-10 is found abundantly in the meat of organs ( liver ), oily fish ( sardines , mackerel , etc.), nuts (e.g. pistachios), legumes , sesame seeds, sunflower seeds, vegetable oils , cabbage, onions, potatoes, spinach, Brussels sprouts and broccoli. Cooking can destroy the coenzyme, however.

Manufacturing

Three processes are used to manufacture Q-10: fermentation of yeast , fermentation of bacteria, and chemical synthesis.

During the yeast fermentation process, Q-10 is created in the so-called trans configuration, which means that it is identical to the naturally occurring CoQ 10 , as found in meat, fish or other foods.

The safety of yeast fermentation has been confirmed by several safety studies carried out by one of the world's leading testing laboratories ( Covance Laboratories Inc. ). In addition, a double-blind, randomized, placebo-controlled study has shown that CoQ 10 from yeast fermentation in doses of up to 900 milligrams per day is absolutely safe and well tolerated.

Q-10, produced by chemical synthesis, contains the cis isomer (a molecular structure that does not exist in naturally occurring Q-10), the safety of which has not yet been investigated intensively.

history

Ubiquinone-10 was discovered in 1957 and was first isolated from bovine hearts by Fred L. Crane . The chemical structure was clarified in 1958 by Karl August Folkers . The British scientist Peter D. Mitchell received the 1978 Nobel Prize in Chemistry for his findings on the role of Q-10 in the Q cycle of complex III of the respiratory chain .

swell

  1. ↑ a b c d e f Data sheet Coenzyme Q-10, 98 +% at AlfaAesar, accessed on June 17, 2019 ( PDF )(JavaScript required) .
  2. ↑ a b Federal Office for Consumer Protection and Food Safety : Announcement of a general decree in accordance with Section 54 of the Food and Feed Code (LFGB) for bringing into the Federal Republic of Germany and placing a food supplement with the addition of coenzyme Q10 (BVL 14/01/002) dated 12 February 2014 (Federal Gazette of March 4, 2014).
  3. ↑ L. Ernster, G. Dallner: Biochemical, physiological and medical aspects of ubiquinone function . Biochim. Biophys. Acta . Volume 1271, 1995, pp. 195-204. PMID 7599208
  4. ↑ PL Dutton et al: Coenzyme Q oxidation reduction reactions in mitochondrial electron transport. In: VE Kagan, PJ Quinn (ed.): Coenzyme Q: Molecular mechanisms in health and disease. CRC Press, 2000, pp. 65-82.
  5. ^ Y. Shindo, E. Witt, D. Han, W. Epstein, L. Packer: Enzymic and non-enzymic antioxidants in epidermis and dermis of human skin. In: Invest. Dermatol. 102, 1994, pp. 122-124.
  6. ↑ AM James et al.: Antioxidant and prooxidant properties of mitochondrial coenzymes Q. In: Arch. Biochem. Biophys. Volume 423, 2004, pp. 47-56. PMID 14989264
  7. ↑ M. Mancuso, D. Orsucci, L. Volpi, V. Calsolaro, G. Siciliano: Coenzyme Q10 in neuromuscular and neurodegenerative disorders . In: Curr Drug Targets . tape 11 , no. 1 , January 2010, p. 111-121 , PMID 20017723 .
  8. ↑ SR Lalani, DG Vladutiu, K. Plunkett, TE Lotze, AM Adesina, F. Scaglia: Isolated mitochondrial myopathy associated with muscle coenzyme Q10 deficiency . In: Arch. Neurol. tape 62 , no. 2 , February 2005, p. 317-320 , doi : 10.1001 / archneur.62.2.317 , PMID 15710863 .
  9. ↑ S. Sacconi, E. Trevisson, L. Salviati include: Coenzyme Q10 is frequently reduced in muscle of patients with mitochondrial myopathy . In: Neuromuscul. Disord. tape 20 , no. 1 , January 2010, p. 44-48 , doi : 10.1016 / j.nmd.2009.10.014 , PMID 19945282 .
  10. ^ L. Marcoff, PD Thompson: The role of coenzyme Q10 in statin-associated myopathy: a systematic review . In: J. Am. Coll. Cardiol. tape 49 , no. June 23 , 2007, pp. 2231-2237 , doi : 10.1016 / j.jacc.2007.02.049 , PMID 17560286 ( onlinejacc.org ).
  11. ↑ MetaCyc: ubiquinone-10 biosynthesis (eukaryotic)
  12. ^ C. Weber: Dietary intake and absorption of coenzyme Q. In: VE Kagan, PJ Quinn (Ed.): Coenzyme Q: Molecular mechanisms in health and disease. CRC Press, 2000, pp. 209-215.
  13. ↑ A. Kalén, EL Appelkvist, G. Dallner: Age-related changes in the lipid Compositions of rat and human tissues . In: Lipids . tape 24 , no. 7 , July 1989, p. 579-584 , PMID 2779364 .
  14. ↑ FL Crane: Biochemical functions of coenzyme Q10. In: Journal of the American College of Nutrition. Volume 20, Number 6, December 2001, pp. 591-598. PMID 11771674 (Review).
  15. ↑ Q10 - We apply cream to ourselves young .
  16. ↑ KD Williams, JD Maneka, M. Abdel-Hameed, RL Hall, TE Palmer, M. Kitano, T. Hidaka: 52-Week oral gavage chronic toxicity study with ubiquinone in rats with a 4-week recovery. In: J Agric Food Chem . 47, 1999, pp. 3756-3763.
  17. ↑ H. Ikematsu, K. Nakamura, S. Harashima, K. Fujii, N. Fukutomi: Safety assessment of Coenzyme Q10 (Kaneka Q10) in healthy subjects: A double-blind, randomized, placebo-controlled trial. In: Regul Toxicol Pharmacol . 44, 2006, pp. 212-218.
  18. ↑ FL Crane et al.: Isolation of a quinone from beef heart mitochondria. In: Biochim. Biophys. Acta. Volume 25, 1957, pp. 220-221. PMID 13445756 .
  19. ^ Obituary: Karl Folkers

literature

  • FL Crane: Biochemical functions of coenzyme Q10. In: Journal of the American College of Nutrition. Volume 20, Number 6, December 2001, pp. 591-598. PMID 11771674 (Review).
  • JTA Ely, CA Krone: A brief update on ubiquinone (coenzyme Q10) . In: J. Orthomolecular. Med. Vol. 15, 2000, pp. 63-68.
  • L. Ernster, G. Dallner: Biochemical, physiological and medical aspects of ubiquinone function. In: Biochim. Biophys. Acta. Volume 1271, 1995, pp. 195-204. PMID 7599208 .

See also

Web links

Wikibooks: Ubiquinone Biosynthesis  - Learning and Teaching Materials