What is the Difference Between Ubiquinol and CoQ10

The key difference between Ubiquinol and CoQ10 is that ubiquinol is a completely reduced form, whereas CoQ10 is a completely oxidized form.

Ubiquinol and CoQ10 are important components in the human body involved in different pathways. The terms ubiquinol and CoQ10 refer to the reduced or oxidized forms of the same molecule/compound.

CONTENTS

1. Overview and Key Difference
2. What is Ubiquinol
3. What is CoQ10
4. Ubiquinol vs CoQ10 in Tabular Form
5. Summary – Ubiquinol vs CoQ10 

What is Ubiquinol?

Ubiquinol can be defined as an electron-rich form of coenzyme Q10. The naturally occurring form of ubiquinol is named in the IUPAC system as 2,3-dimethoxy-5-methyl-6-poly prenyl-1,4-benzoqionol. It has a polyprenylated side chain, which is 9-10 units long in mammals.

There are three major forms of coenzyme Q10 in three different redox states: ubiquinone, semiquinone, and ubiquinol. Ubiquinone is the fully oxidized state. Semiquinone or ubisemiquinone is a partially reduced state, while ubiquinol is the completely reduced state.

The chemical formula of ubiquinol is C₅₉H₉₂O₄. The molar mass of this compound is 865.38 g/mol. The appearance can be given as off-white powder. The melting point of ubiquinol is 45.6 degrees Celsius. It is practically insoluble in water. Moreover, it is not classified as a vitamin since humans can synthesize ubiquinol in the body.

When considering the bioavailability of ubiquinol, it has an enhanced bioavailability compared to coQ10 because it has two additional hydrogens that can result in the conversion of two ketone groups into hydroxyl groups on the active portion of the molecule. These additional hydrogens can increase the polarity of the molecule, increasing the enhancement of bioavailability.

Ubiquinol is a reduced product of ubiquinone. The tail of this compound contains 10 isoprene units. Ubiquinone can be reduced to ubiquinol via complexes I and II in the electron transfer chain. This can be observed in the Q cycle, in which cytochrome b converts ubiquinol into ubiquinone in a cyclic pattern. There, when ubiquinol is bonded to cytochrome b, the pKa of the phenolic group decreases, resulting in the formation of phenoxide anion via proton ionization.

What is CoQ10?

CoQ10 or coenzyme Q10 is a family of coenzymes that can be found in animals and most bacteria. It is also commonly known as ubiquinone. This is because there are three major forms of coenzyme Q10: ubiquinone, semiquinone, and ubiquinol.

The most common form that we can find in humans is coenzyme Q10 or ubiquinone-10. However, ubiquinone is not approved by the FDA for the treatment of any medical condition. But it can be used as a dietary supplement and also an ingredient in some cosmetics.

The chemical formula of CoQ10 is C₅₉H₉₀O₄. Its molar mass is 863.36 g/mol. It appears as a yellow or orange solid. The melting point of CoQ10 ranges between 48-52 degrees Celsius, and it is insoluble in water. We can categorize it as a 1,4-benzoquinone. Here, the letter Q in the Coenzyme Q10 refers to the number of isoprenyl chemical subunits found in its tail. Naturally occurring ubiquinones have 6-0 subunits.

Moreover, the CoQ10 molecule can act as a two-electron carrier and a one-electron carrier which is central to the role of this compound in the electron transport chain due to the iron-sulfur clusters. These clusters can accept only one electron at a time. Moreover, it can act as a free-radical-scavenging antioxidant.

What is the Difference Between Ubiquinol and CoQ10?

CoQ10 molecule can exist in three phases: completely oxidized form, partially reduced form, and completely reduced form. The completely oxidized form is ubiquinone, and it is also known commonly as CoQ10. The completely reduced form is ubiquinol. Therefore, the key difference between Ubiquinol and CoQ10 is that ubiquinol is a completely reduced form, whereas CoQ10 is a completely oxidized form.

The below infographic presents the differences between Ubiquinol and CoQ10 in tabular form for side-by-side comparison.

Summary – Ubiquinol vs CoQ10

Ubiquinol can be defined as an electron-rich form of coenzyme Q10. CoQ10 or coenzyme Q10 is a family of coenzymes that can be found in animals and most bacteria. The key difference between Ubiquinol and CoQ10 is that ubiquinol is a completely reduced form, whereas CoQ10 is a completely oxidized form. Moreover, ubiquinol is comparatively more polar than CoQ10 due to the presence of extra hydrogen atoms.

Reference:

1. “Coenzyme Q10 (Ubiquinol) Oral: Uses, Side Effects, Interactions, Pictures, Warnings & Dosing.” WebMD.

Image Courtesy:

1. “Ubiquinol” By Karl Oberholser at English Wikipedia – Transferred from en.Wikipedia to Commons by Ronhjones using CommonsHelper. (Public Domain) via Commons Wikimedia
2. “CoenzymeQ10” By Sponk (talk) – Own work (Public Domain) via Commons Wikimedia