|
|
| Line 1: |
Line 1: |
| {{Chembox | | {{Short description|A reduced form of coenzyme Q10}} |
| | Watchedfields = changed
| | {{DISPLAYTITLE:Ubiquinol}} |
| | verifiedrevid = 447333645
| |
| | Name = Ubiquinol
| |
| | ImageFile = Ubiquinol structure.png
| |
| | ImageSize = 270 | |
| | IUPACName = 2-[(2E,6E,10E,14E,18E,22E,26E,30E,34E)-3,7,11,15,19,23,27,31,35,39-decamethyltetraconta-2,6,10,14,18,22,26,30,34,38-decaenyl]-5,6-dimethoxy-3-methyl-benzene-1,4-diol
| |
| | OtherNames = Reduced CoQ<sub>10</sub>, unoxidized CoQ<sub>10</sub>, CoQ<sub>10</sub>H<sub>2</sub>, or dihydroquinone
| |
| | Section1 = {{Chembox Identifiers
| |
| | CASNo_Ref = {{cascite|correct|??}}
| |
| | CASNo =
| |
| | PubChem = 9962735
| |
| | SMILES = }}
| |
| | Section2 = {{Chembox Properties
| |
| | C=59 | H = 92 | O=4
| |
| | Appearance = off-white powder
| |
| | Density =
| |
| | MeltingPt = 45.6 C
| |
| | BoilingPt =
| |
| | Solubility = practically insoluble in water
| |
| }}
| |
| }} | |
|
| |
|
| == Coenzyme Q<sub>10</sub>: Structure, Redox States, and Biological Functions ==
| | '''Ubiquinol''' is the reduced form of [[coenzyme Q10]] (CoQ10), a vital component in the production of cellular energy and an important antioxidant in the body. It plays a crucial role in the [[electron transport chain]] within [[mitochondria]], where it helps generate [[adenosine triphosphate]] (ATP), the primary energy currency of cells. |
|
| |
|
| | ==Biological Role== |
| | Ubiquinol is a key player in the [[mitochondrial]] electron transport chain, which is essential for [[aerobic respiration]]. It acts as an electron carrier, shuttling electrons between [[complex I]] and [[complex II]] to [[complex III]] in the chain. This process is critical for the production of ATP, which provides energy for various cellular processes. |
|
| |
|
| [[File:Ubiquinol structure.png|thumb|Ubiquinol structure]] | | In addition to its role in energy production, ubiquinol functions as a potent [[antioxidant]]. It helps protect cells from oxidative damage by neutralizing [[free radicals]], which are unstable molecules that can cause cellular damage and contribute to [[aging]] and various [[diseases]]. |
|
| |
|
| Coenzyme Q<sub>10</sub> (CoQ<sub>10</sub>), known for its central role in [[Bioenergetics|cellular energy production]] and as a potent [[antioxidant]], is a ubiquitous component found in the [[mitochondria]] of eukaryotic cells. Its structure and redox properties enable it to participate in various vital physiological processes.
| | ==Health Benefits== |
| | Ubiquinol is believed to support [[cardiovascular health]] by improving the function of the [[heart]] and [[blood vessels]]. It may help reduce [[blood pressure]] and improve [[endothelial function]], which is important for maintaining healthy [[arteries]]. |
|
| |
|
| == Chemical Structure ==
| | Furthermore, ubiquinol is thought to enhance [[immune function]] and support [[brain health]]. It may help protect against [[neurodegenerative diseases]] by reducing oxidative stress in the [[brain]]. |
| The natural ubiquinol form of CoQ<sub>10</sub> is identified chemically as 2,3-dimethoxy-5-methyl-6-poly prenyl-1,4-benzoquinol. A distinguishing feature of this molecule in [[mammal]]s is its polyprenylated side-chain, which typically consists of 9-10 isoprenyl subunits.
| |
|
| |
|
| == Redox States and Function == | | ==Supplementation== |
| CoQ<sub>10</sub> can exist in three distinct [[redox]] states:
| | Ubiquinol is available as a dietary supplement and is often recommended for individuals who may have difficulty converting CoQ10 to its active form, such as older adults or those with certain health conditions. It is considered more bioavailable than [[ubiquinone]], the oxidized form of CoQ10, meaning it is more easily absorbed and utilized by the body. |
|
| |
|
| * '''Fully Oxidized''' ([[ubiquinone]]): This form is devoid of electrons. | | ==Related Pages== |
| * '''Partially Reduced''' ([[semiquinone]] or ubisemiquinone): This intermediate state has acquired one electron. | | * [[Coenzyme Q10]] |
| * '''Fully Reduced''' (ubiquinol): The completely reduced form, endowed with two electrons. | | * [[Mitochondria]] |
| | * [[Antioxidant]] |
| | * [[Electron transport chain]] |
| | * [[Adenosine triphosphate]] |
|
| |
|
| The ability of CoQ<sub>10</sub> to oscillate between these states, especially the interchange of two [[electron]]s between its oxidized (ubiquinone) and reduced (ubiquinol) forms, underpins its functional significance in the body.
| | [[Category:Biochemistry]] |
| | | [[Category:Antioxidants]] |
| === Cellular Energy Production ===
| | [[Category:Dietary supplements]] |
| CoQ<sub>10</sub> plays an instrumental role in the [[Electron transport chain|electron transport chain]] in mitochondria. By shuttling electrons between complexes, it facilitates the generation of adenosine triphosphate (ATP), the primary energy currency of cells.
| |
| | |
| === Antioxidant Defense ===
| |
| Ubiquinol, the reduced form of CoQ<sub>10</sub>, acts as a formidable [[antioxidant]], neutralizing harmful reactive oxygen species (ROS) that can damage cellular structures, including lipids, proteins, and DNA. Its antioxidant capabilities are rooted in its ability to donate electrons, converting harmful oxidants to stable, non-reactive species.<ref>{{cite journal |pmid=5922959 |year=1966 |last1=Mellors |first1=A |last2=Tappel |first2=AL |title=The inhibition of mitochondrial peroxidation by ubiquinone and ubiquinol |volume=241 |issue=19 |pages=4353–6 |journal=The Journal of Biological Chemistry |url=http://www.jbc.org/cgi/pmidlookup?view=long&pmid=5922959}}</ref>
| |
| | |
| == Clinical Implications ==
| |
| Given its pivotal roles in energy metabolism and oxidative stress defense, CoQ<sub>10</sub> has been investigated for potential therapeutic applications in various clinical conditions. These range from mitochondrial disorders to neurodegenerative diseases, cardiovascular conditions, and even aging.
| |
| | |
| ==Characteristics==
| |
| | |
| Ubiquinol is a [[lipid]]-soluble benzoquinol that is found in all cellular systems and in nearly every [[cell (biology)|cell]], [[tissue (biology)|tissue]], and [[organ (biology)|organ]] in mammals. Ubiquinol is acquired through [[biosynthesis]], supplementation, and, in small amounts, [[diet (nutrition)|diet]]. Ubiquinol has an established role as an essential component of the [[electron transport chain]] transferring electrons resulting in [[ATP synthesis]]. In mammals, [[Adenosine triphosphate|ATP]] production takes place predominantly in [[mitochondria]] and to a lesser extent in other [[organelle]]s such as the [[Golgi apparatus]] or [[endoplasmic reticulum]]. The mitochondria typically produce nearly 95% of the energy required for cellular growth, development, and healthy [[metabolism]]. The antioxidant action of ubiquinol is now considered to be one of the most important functions in cellular systems.
| |
| | |
| Ubiquinol is the antioxidant form of CoQ10 and is essential for mitochondrial synthesis of energy. It is the only known lipid-soluble antioxidant that is endogenously synthesized, protecting biological membranes against [[lipid peroxidation]] as well as regenerating other antioxidants such as [[Vitamin C]] and [[Vitamin E]].
| |
| | |
| Because humans can synthesize ubinquinol, it is not classed as a vitamin.<ref name="Banerjee2007">{{cite book |author=Banerjee R |title=Redox Biochemistry |url=http://books.google.com/books?id=ynFUOEgjXYgC&pg=PA35 |year=2007 |publisher=John Wiley & Sons |isbn=978-0-470-17732-7 |page=35}}</ref>
| |
| | |
| ==Bioavailability==
| |
| It is well-established that CoQ<sub>10</sub> is not well absorbed into the body, as has been published in many peer-reviewed scientific journals.<ref>{{cite journal |doi=10.1074/jbc.M501527200 |title=Interactions of Mitochondria-targeted and Untargeted Ubiquinones with the Mitochondrial Respiratory Chain and Reactive Oxygen Species: Implications for the use of exogenous ubiquinones as therapies and experimental tools |year=2005 |last1=James |first1=Andrew M. |journal=Journal of Biological Chemistry |volume=280 |issue=22 |pages=21295–312 |pmid=15788391 |last2=Cochemé |first2=Helena M. |last3=Smith |first3=Robin A. J. |last4=Murphy |first4=Michael P.}}</ref> Since the ubiquinol form has two additional hydrogens, it results in the conversion of two [[ketone group]]s into [[hydroxyl group]]s on the active portion of the molecule. This causes an increase in the [[Chemical polarity|polarity]] of the CoQ<sub>10</sub> molecule and may be a significant factor behind the observed enhanced bioavailability of ubiquinol. Taken orally, ubiquinol exhibits greater bioavailability than ubiquinone.<ref>{{cite journal |doi=10.1016/j.yrtph.2006.07.001 |title=Study on safety and bioavailability of ubiquinol (Kaneka QH™) after single and 4-week multiple oral administration to healthy volunteers |year=2007 |last1=Hosoe |first1=Kazunori |last2=Kitano |first2=Mitsuaki |last3=Kishida |first3=Hideyuki |last4=Kubo |first4=Hiroshi |last5=Fujii |first5=Kenji |last6=Kitahara |first6=Mikio |journal=Regulatory Toxicology and Pharmacology |volume=47 |pages=19–28 |pmid=16919858 |issue=1}}</ref>
| |
| | |
| However, there are authorities that dispute whether ubiquinol is more bioavailable in practice rather than in theory compared to CoQ<sub>10</sub> supplements because those have their CoQ<sub>10</sub> molecules dissolved in lipid micelles, which then deliver their cargo to the plasma membrane in the intestinal wall. There they dissolve via simple diffusion in the intestinal cells, then onto the [[lymphatic vessel]]s, and then into the venous system. Since ubiquinol and CoQ<sub>10</sub> are redox pairs and can and are rapidly inter-converted in the body, it is not clear that ubiqinol's more [[Hydrophile|hydrophilic]] nature compared to CoQ<sub>10</sub> is of practical significance.<ref>{{cite web|last=Judy|first=William|title=Coenzyme Q10 Facts or Fiction|url=http://www.thorne.com/media/pdfs/Q-Best_Sheet_Email_Click.pdf|publisher=Thorne Research|accessdate=9 December 2013}}</ref>
| |
| | |
| ==Content in foods==
| |
| In foods, there are varying amounts of ubiquinol. An analysis of a range of foods found ubiquinol to be present in 66 out of 70 items and accounted for 46% of the total coenzyme Q10 intake. The following chart is a sample of the results.<ref>{{cite journal |doi=10.1016/j.jfca.2007.10.003 |title=Food content of ubiquinol-10 and ubiquinone-10 in the Japanese diet |year=2008 |last1=Kubo |first1=Hiroshi |last2=Fujii |first2=Kenji |last3=Kawabe |first3=Taizo |last4=Matsumoto |first4=Shuka |last5=Kishida |first5=Hideyuki |last6=Hosoe |first6=Kazunori |journal=Journal of Food Composition and Analysis |volume=21 |issue=3 |pages=199–210}}</ref>
| |
| | |
| {| class="wikitable"
| |
| |-
| |
| ! Food
| |
| ! Ubiquinol (μg/g)
| |
| ! Ubiquinone (μg/g)
| |
| |-
| |
| | Beef (shoulder)
| |
| | 5.36
| |
| | 25
| |
| |-
| |
| | Beef (liver)
| |
| | 40.1
| |
| | 0.4
| |
| |-
| |
| | Pork (shoulder)
| |
| | 25.4
| |
| | 19.6
| |
| |-
| |
| | Pork (thigh)
| |
| | 2.63
| |
| | 11.2
| |
| |-
| |
| | Chicken (breast)
| |
| | 13.8
| |
| | 3.24
| |
| |-
| |
| | Mackerel
| |
| | 0.52
| |
| | 10.1
| |
| |-
| |
| | Tuna (canned)
| |
| | 14.6
| |
| | 0.29
| |
| |-
| |
| | Yellowtail
| |
| | 20.9
| |
| | 12.5
| |
| |-
| |
| | Broccoli
| |
| | 3.83
| |
| | 3.17
| |
| |-
| |
| | Parsley
| |
| | 5.91
| |
| | 1.57
| |
| |-
| |
| | Orange
| |
| | 0.88
| |
| | 0.14
| |
| |}
| |
| | |
| ==Molecular aspects==
| |
| '''Ubiquinol''' is a benzoquinol and is the reduced product of [[ubiquinone]] also called [[Coenzyme Q10|coenzyme Q<sub>10</sub>]]. Its tail consists of 10 [[isoprene]] units.
| |
| [[File:Ubiquinol.png|center|800px|Ubiquinol]]
| |
| | |
| The reduction of ubiquinone to ubiquinol occurs in Complexes I & II in the [[electron transfer chain]]. The Q cycle<ref>{{cite journal |doi=10.1016/0968-0004(83)90348-1 |title=The Q cycle, an ubiquitous mechanism of electron transfer |year=1983 |last1=Slater |first1=E.C. |journal=Trends in Biochemical Sciences |volume=8 |issue=7 |pages=239–42}}</ref> is a process that occurs in [[cytochrome b]],<ref>{{cite journal |author=Trumpower BL |title=Cytochrome bc1 complexes of microorganisms |journal=Microbiol. Rev. |volume=54 |issue=2 |pages=101–29 |date=June 1990 |pmid=2163487 |pmc=372766}}</ref><ref>{{cite journal |first1=Bernard L. |last1=Trumpower |title=The Protonmotive Q Cycle |journal=The Journal of Biological Chemistry |pmid=2164001 |url=http://www.jbc.org/cgi/pmidlookup?view=long&pmid=2164001 |year=1990 |volume=265 |issue=20 |pages=11409–12}}</ref> a component of Complex III in the [[electron transport chain]], and that converts ubiquinol to ubiquinone in a cyclic fashion. When ubiquinol binds to cytochrome b, the pKa of the phenolic group decreases so that the proton ionizes and the phenoxide anion is formed.
| |
| | |
| [[File:Ubiquinol semiphenoxide.png|center|800px|Ubiquinol, semiphenoxide]]
| |
| If the phenoxide oxygen is oxidized, the semiquinone is formed with the unpaired electron being located on the ring.
| |
| [[File:Ubiquinol semiquinone.png|center|800px|Ubiquinol]]
| |
| | |
| A page on Proteopedia, Complex III of Electron Transport Chain,<ref>http://proteopedia.org/wiki/index.php/Complex_III_of_Electron_Transport_Chain{{full|date=June 2013}}{{MEDRS|date=June 2013}}</ref> contains rotatable 3-D structures of Complex III, which may be used to study the peptide structures of Complex III and the mechanism of the Q cycle.
| |
| | |
| ==References==
| |
| {{reflist|colwidth=30em}}
| |
| | |
| ==External links==
| |
| * [http://chemsub.online.fr/name/ubiquinol.html ChemSub Online: Ubiquinol]
| |
| | |
| [[Category:Nutrition]]{{stub}} | |
A reduced form of coenzyme Q10
Ubiquinol is the reduced form of coenzyme Q10 (CoQ10), a vital component in the production of cellular energy and an important antioxidant in the body. It plays a crucial role in the electron transport chain within mitochondria, where it helps generate adenosine triphosphate (ATP), the primary energy currency of cells.
Biological Role[edit]
Ubiquinol is a key player in the mitochondrial electron transport chain, which is essential for aerobic respiration. It acts as an electron carrier, shuttling electrons between complex I and complex II to complex III in the chain. This process is critical for the production of ATP, which provides energy for various cellular processes.
In addition to its role in energy production, ubiquinol functions as a potent antioxidant. It helps protect cells from oxidative damage by neutralizing free radicals, which are unstable molecules that can cause cellular damage and contribute to aging and various diseases.
Health Benefits[edit]
Ubiquinol is believed to support cardiovascular health by improving the function of the heart and blood vessels. It may help reduce blood pressure and improve endothelial function, which is important for maintaining healthy arteries.
Furthermore, ubiquinol is thought to enhance immune function and support brain health. It may help protect against neurodegenerative diseases by reducing oxidative stress in the brain.
Supplementation[edit]
Ubiquinol is available as a dietary supplement and is often recommended for individuals who may have difficulty converting CoQ10 to its active form, such as older adults or those with certain health conditions. It is considered more bioavailable than ubiquinone, the oxidized form of CoQ10, meaning it is more easily absorbed and utilized by the body.
Related Pages[edit]
