Ubiquinol
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| n = 9–10 (mammals) or 10 (humans) | |||||||||||||
| General | |||||||||||||
| Surname | Ubiquinol | ||||||||||||
| other names | |||||||||||||
| Molecular formula | C 59 H 92 O 4 | ||||||||||||
| Brief description |
White dust |
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| properties | |||||||||||||
| Molar mass | 865.36 g mol −1 | ||||||||||||
| Physical state |
firmly |
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| Melting point |
47 ° C |
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| As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions . | |||||||||||||
Ubiquinol ( eng.ubiquinol , also ubihydroquinone or QH 2 for short ) is an electron-rich ( reduced ) form of the coenzyme Q 10 . The natural ubiquinol form of coenzyme Q 10 is 2,3-dimethoxy-5-methyl-6-polyprenyl-1,4-benzoquinol, the polyprenylated side chain being 9-10 units long in mammals and 10 units in length in humans. Coenzyme Q 10 (CoQ10) exists in three redox states , fully oxidized ( ubiquinone-10 ), partially reduced ( semiquinone or ubiquinone), and fully reduced (ubiquinol). The redox functions of ubiquinol in cellular energy production and in antioxidant protection are based on the ability to exchange two electrons in a redox cycle between ubiquinol (reduced) and the (oxidized) ubiquinone form.
Occurrence
Ubiquinol is a fat-soluble benzoquinol found in all cell systems and in virtually every cell, tissue and organ in mammals . Ubiquinol is supplied to the body through biosynthesis , food supplements and, in small quantities, also through food . Ubiquinol plays an important role as a key component of the electron transport chain through which the electrons are provided for the ATP synthase . In mammals, ATP production occurs mainly in the mitochondria and, to a lesser extent, in other organelles such as the Golgi apparatus or the endoplasmic reticulum. Usually the mitochondria produce almost 95% of the energy required for cell growth and development and a healthy cell metabolism . The antioxidant effect of ubiquinol is now regarded as one of the most important functions in cell systems. Ubiquinol is a powerful lipophilic antioxidant that is able to regenerate other antioxidants like vitamin E or vitamin C. Recent studies also confirm the role of ubiquinol in gene expression , which is involved in communication, metabolism and transport of human cells.
Ubiquinol in food
Different amounts of ubiquinol are found in food. The analysis of a wide range of foods showed that ubiquinol was found in 63 out of 70 different products and accounted for 46% of the total Coenzyme Q 10 intake in the Japanese diet.
| food | Ubiquinol (µg / g) | Ubiquinone (µg / g) |
|---|---|---|
| Beef (shoulder) | 5.36 | 25th |
| Beef (liver) | 40.1 | 0.4 |
| Pig (shoulder) | 25.4 | 19.6 |
| Pig (thigh) | 2.63 | 11.2 |
| Poultry (breast) | 13.8 | 3.24 |
| mackerel | 0.52 | 10.1 |
| Tuna (can) | 14.6 | 0.29 |
| Yellowtail | 20.9 | 12.5 |
| Broccoli | 3.83 | 3.17 |
| parsley | 5.91 | 1.57 |
| orange | 0.88 | 0.14 |
properties
Ubiquinol is a benzoquinol and a reduced form of ubiquinone , which is also called coenzyme Q 10 .
The reduction of ubiquinone to ubiquinol takes place in complexes I and II of the electron transfer chain. The Q cycle is a process that takes place with the help of cytochrome c , a component of complex III in the electron transport chain, and which converts ubiquinol into ubiquinone in a cyclical process. When ubiquinol binds to cytochrome c, the pKa of the phenolic group decreases, so that the proton ionizes and the phenoxide anion is formed.
When the Phenoxidsauerstoff is oxidized to form the semiquinone , wherein the unpaired electron in the ring.
Bioavailability
It is known that coenzyme Q 10 is not well absorbed by the body, as has been shown in many peer-reviewed scientific journals. Since its ubiquinol form has two additional hydrogen atoms, this leads to the conversion of two ketone groups to hydroxy groups on the active part of the molecule. This results in an increased polarity of the coenzyme Q 10 molecule and could be a significant factor in the observed greater bioavailability of ubiquinol. Taken orally, ubiquinol is more bioavailable than ubiquinone: 150 mg per day in a softgel capsule resulted in minimum blood values of 3.84 µg / g within 4 weeks.
function
Ubiquinol's primary function is to assist in the synthesis of cellular energy. Ubiquinol is found in concentrated form in the mitochondrial inner membrane, where it serves as a carrier of two reduction equivalents per mole in complexes I and II in the direction of complex III of the mitochondrial electron transfer chain. In this process, ubiquinol is used to produce ATP (adenosine triphosphate), the main source of energy in living organisms.
Furthermore, ubiquinol acts as an acceptor of electrons in the oxidation of toxic hydrogen sulfide by the sulfide: ubiquinone oxidoreductase . These electrons are also used in ATP production.
Studies
Antioxidant and aging effects
Ubiquinol is a highly effective fat-soluble antioxidant that, among other things, a. is able to regenerate α-tocopherol . Its importance is underscored by the fact that it is the only fat-soluble antioxidant that is synthesized in the body. Scientists working specifically with coenzyme Q 10 have investigated the relationship between suboptimal states, which are characterized by high oxidative stress, and the corresponding levels of ubiquinone and ubiquinol in the body - both of which together represent one value, the total coenzyme Q 10 is called. Disturbances caused by increased oxidative stress can dramatically alter ubiquinol and ubiquinone levels in the body, a factor that scientists express as the ratio of ubiquinol to ubiquinone (ubiquinol: ubiquinone). Another form of representation is the ubiquinol ratio, i.e. the percentage of ubiquinol in the total amount of coenzyme Q 10 . A significant change was e.g. B. found in the coenzyme Q 10 profile of diabetes II patients. Specifically, a decrease in the plasma-ubiquinol ratio was found, which suggests an increase in oxidative stress. Another study showed the decrease in ubiquinol under conditions of increased oxidative stress. Patients suffering from hepatitis, cirrhosis and hepatoma all showed a decrease in their ubiquinol concentrations, while the levels of total coenzyme Q 10 (ubiquinol + ubiquinone) did not decrease. Recent research suggests that decreased ubiquinol levels may be related to aging. Elderly people not only have decreased coenzyme Q 10 biosynthesis, but also a reduced ability to convert ubiquinone into ubiquinol.
Neural health
A number of smaller studies have shown that coenzyme Q 10 has a positive effect on the neurological system. A study from 2002 examined the effect of coenzyme Q 10 (ubiquinone) in patients with the onset of Parkinson's disease. The scientists in this multi-center phase II study found that ubiquinone reduced the impairment of function in Parkinson's disease. In view of these encouraging results, a much larger, multi-center phase III study was then initiated. Another study looked at the protective effects of ubiquinone and ubiquinol in rats given MPTP (1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine), a neurotoxin that causes changes as in idiopathic Parkinson's disease evokes. MPTP is selectively toxic to the cells of the substantia nigra, specialized cells in the brain stem that play a role in motor control and dopamine neurotransmitter synthesis. Both forms offered protection against MTPT-induced toxicity, but ubiquinol produced a stronger effect.
Kidney health
Scientists from the University of Tokyo have investigated the role of antioxidants in chronic kidney disease. An animal model of chronic kidney disease was developed as a preliminary study. Three experimental groups were defined: a control group, a high-salt diet group, and a high-salt diet plus ubiquinol group. Compared to the control group, the high salty food increased oxidative stress (measured by the production of superoxide anion in kidney tissue), increased blood pressure and caused albuminuria. In contrast, the high-salt diet and ubiquinol supplement group showed results that indicated a significant protective function for the kidneys by ubiquinol, including decreased production of superoxide anion (antioxidant effect), decreased urine albumin, and a decrease in hypertension.
Inflammation and gene expression
Several studies have been initiated to investigate the effect of coenzyme Q 10 on gene expression. The computer-aided analysis of hundreds of genes has shown that coenzyme Q 10 acts on 17 different genes which are functionally linked by 4 different cellular connection pathways : G-protein coupled receptors , the JAK-STAT signal path , integrin and beta Arrestin . The researchers in this study then undertook detailed investigations with the ubiquinol form. An in vitro study on a human monocyte cell line (THP-1) exposed to inflammation-stimulating lipopolysaccharides (LPS) showed that ubiquinol blocked the release of inflammatory substances. The scientists found that ubiquinol had a stronger effect on these inflammation triggers than ubiquinone.
Further research results
One study looked at the association between ubiquinol and blood lipids in patients with coronary heart disease. The researchers tried to find out whether there was a connection between the extent of stenosis (i.e. the narrowing of blood vessels) and the concentrations of ubiquinol and blood lipids. Coenzyme Q 10 is being investigated in relation to blood lipids because it is almost entirely found in the blood in lipoproteins (especially in the low density lipoprotein LDL-C). For their part, lipoproteins are carriers of fat-soluble cholesterol in the bloodstream (cholesterol does not occur freely), hence the connection between coenzyme Q 10 , cholesterol and lipoproteins. In contrast to other studies with dietary supplements, the study participants received no ubiquinol or statins. To determine the extent of stenosis, subjects underwent coronary angiography. Of a total of 36 subjects, 20 were classified as negative (less than 50% stenosis), 16 subjects were classified as positive (more than 70% stenosis). The results showed that the quotient of ubiquinol to blood lipids was significantly higher in the low-stenosis group; in contrast, the high-stenosis group had significantly low values of the ubiquinol / blood fat quotient. The scientists highlighted that the ubiquinol / blood lipid ratio appears to be an important factor in determining progressive atherosclerotic changes. Even if this was not an intervention study, the connection between the ubiquinol / blood lipid ratio and the extent of the stenosis was clearly evident.
Web links
- Rotatable 3D structures of Complex III on Proteopedia.org
Individual evidence
- ↑ Patent US2008138326 : Method for cancer treatment, carcinogenesis suppression or mitigation of adverse reactions of anticancer agents. Published June 12, 2008 , Inventors: Fujii, Toshihide; Kato, Masanori; Sakamoto, Hirokazu; Shinagawa, Yoshiyuki; Kitano, Mitsuaki; Hosoe, Kazunori.
- ↑ Patent GB947643 : Substituted chrome compounds. Published January 22, 1964 .
- ↑ This substance has either not yet been classified with regard to its hazardousness or a reliable and citable source has not yet been found.
- ↑ G. Lenaz et al .: Localization and mobility of coenzyme Q in lipid bilayers and membranes . In: Biofactors , 1999, 9, pp. 87-93.
- ↑ M. Nakamura, T. Hayashi: One- and Two-electron reduction of quinones by rat liver subcellular fractions . In: J Biochem , 1994, 115, pp. 334-344.
- ↑ M. Battino et al .: Natural distribution and occurrence of coenzyme Q homologues . In: Membr. Biochem. , 1990, 9, pp. 179-190.
- ↑ DE Green, Tzagoloff: The mitochondrial electron transfer chain . In: Arch. Biochem. Biophys. , 1966, 116, pp. 293-304.
- ^ B. Frei et al .: Ubiquinol-10 is an effective lipid-soluble antioxidant at physiological concentrations . In: Proc. Natl. Acad. Sci. USA , 1990, 87, pp. 4879-4883.
- ↑ A. Arroyo et al .: Ubiquinol regeneration by plasma membrane ubiquinone reductase . In: Protoplasma , 1998, 205, pp. 107-113.
- ^ H Kubo et al .: Food Content of ubiquinol-10 and ubiquinone-10 in the Japanese diet . In: Journal of Food Composition and Analysis , 2008, 21, pp. 199-210, doi: 10.1016 / j.jfca.2007.10.003 .
- ^ EC Slater: The Q cycle: An ubiquitous mechanism of electron transfer . In: Trends in Biochemical Sciences , 1983, 8, pp. 239-242.
- ↑ BL Trumpower: Cytochrome bc1 complexes of microorganisms . In: Microbiological Reviews , 1990, 54, pp 101-129.
- ↑ BL Trumpower: The proton motive Q cycle-energy transduction by coupling of proton translocation to electron transfer by the cytochrome bc1 complex . In: J. Biol. Chem. , 1990, 265, pp. 11409-11412.
- ↑ AM James et al .: Interactions of Mitochondria-targeted and Untargeted Ubiquinones with the Mitochondrial Respiratory Chain and Reactive Oxygen Species . In: Journal of Biochemistry . 2005, 280 (22), pp. 21295-21312, PMID 15788391 .
- ↑ K Hosoe et al .: Study On Safety And bioavailability of ubiquinol (Kaneka QH) after single and 4-week multiple oral administration to healthy volunteers . In: Regulatory Toxicology and Pharmacology , 2007, 47, pp. 19-28, PMID 16919858 .
- ^ P Navas et al .: The importance of plasma membrane coenzyme Q in aging and stress response . In: Mitochondrion , 2007, 7S, S34-S40.
- ↑ S Lim et al .: Oxidative burden in prediabetic and diabetic individuals: evidence from plasma coenzyme Q10 . In: Diabetic Medicine , 2006, 23, pp. 1344-1349.
- ↑ Y Yamamoto et al .: Plasma ubiquinone to ubiquinol ratio in patients with hepatitis, cirrhosis, and hepatoma, and in patients with percutaneous transluminal coronary reperfusion . In: BioFactors , 1999, 9, pp. 241-246.
- ^ H Wada et al .: Redox Status Of Coenzyme Q10 Is Associated With Chronological Age . In: Journal of the American Geriatrics Society , 2007, 55 (7), pp. 1142-1144.
- ↑ C Shults et al .: Effects of Coenzyme Q10 in Early Parkinson Disease . In: Archives of Neurology , 2002, 59 pp. 1541-1550.
- ↑ C Cleren et al .: Therapeutic effects of coenzyme Q10 (CoQ10) and reduced CoQ10 in the MPTP model of Parkinsonism . In: Journal of Neurochemistry , 2008, 104, pp. 1613-1621.
- ↑ A Ishikawa et al .: Renal preservation effect of ubiquinol, the reduced form of coenzyme Q10 . In: Clin Exp Nephrol. , 2010.
- ^ F Döring et al .: Functional Connections and Pathways of Coenzyme Q10-inducible Genes: An In-silico Study . In: IUBMB Life , 2007, 59 (10), pp. 628-633.
- ↑ C Schmelzer et al .: In vitro effects of the reduced form of Coenzyme Q10 on secretion levels of TNF-alpha and chemokines in response to LPS in the human monocytic cell line THP-1 . In: J Clin Biochem Nutr. , 2009, 44, pp. 62-66.
- ↑ MV. Miles: The uptake and distribution of coenzyme Q (10) . In: Mitochondrion , 2007, S72-S77.
- ↑ P Zakova et al .: Ubiquinol-10 / lipids ratios in consecutive patients with different angiographic findings . In: Clinica Chimica Acta , 2007, 380, pp. 133-138.