Dehydroascorbic acid: Difference between revisions

Jump to navigation Jump to search
No edit summary
m (Bot: Automated text replacement (-{{SIB}} + & -{{EH}} + & -{{EJ}} + & -{{Editor Help}} + & -{{Editor Join}} +))
 
Line 33: Line 33:
|}
|}
{{SI}}
{{SI}}
{{EH}}
 


==Chemistry==
==Chemistry==
Line 94: Line 94:
[[Category:Neurological disorders]]
[[Category:Neurological disorders]]
[[Category:Causes of death]]
[[Category:Causes of death]]
{{SIB}}
 
{{WH}}
{{WH}}
{{WikiDoc Sources}}
{{WikiDoc Sources}}

Latest revision as of 00:33, 9 August 2012

Template:Chembox header| Dehydroascorbic acid
Dehydroascorbic acid
Systematic name Dehydroascorbic acid
Chemical formula C6H6O6
Molecular mass 174.13 g/mol
Density x.xxx g/cm³
Melting point xx.x °C
Boiling point xx.x °C
CAS number [xx-xx-xx]
SMILES xxxxx
Template:Chembox header | Disclaimer and references

WikiDoc Resources for Dehydroascorbic acid

Articles

Most recent articles on Dehydroascorbic acid

Most cited articles on Dehydroascorbic acid

Review articles on Dehydroascorbic acid

Articles on Dehydroascorbic acid in N Eng J Med, Lancet, BMJ

Media

Powerpoint slides on Dehydroascorbic acid

Images of Dehydroascorbic acid

Photos of Dehydroascorbic acid

Podcasts & MP3s on Dehydroascorbic acid

Videos on Dehydroascorbic acid

Evidence Based Medicine

Cochrane Collaboration on Dehydroascorbic acid

Bandolier on Dehydroascorbic acid

TRIP on Dehydroascorbic acid

Clinical Trials

Ongoing Trials on Dehydroascorbic acid at Clinical Trials.gov

Trial results on Dehydroascorbic acid

Clinical Trials on Dehydroascorbic acid at Google

Guidelines / Policies / Govt

US National Guidelines Clearinghouse on Dehydroascorbic acid

NICE Guidance on Dehydroascorbic acid

NHS PRODIGY Guidance

FDA on Dehydroascorbic acid

CDC on Dehydroascorbic acid

Books

Books on Dehydroascorbic acid

News

Dehydroascorbic acid in the news

Be alerted to news on Dehydroascorbic acid

News trends on Dehydroascorbic acid

Commentary

Blogs on Dehydroascorbic acid

Definitions

Definitions of Dehydroascorbic acid

Patient Resources / Community

Patient resources on Dehydroascorbic acid

Discussion groups on Dehydroascorbic acid

Patient Handouts on Dehydroascorbic acid

Directions to Hospitals Treating Dehydroascorbic acid

Risk calculators and risk factors for Dehydroascorbic acid

Healthcare Provider Resources

Symptoms of Dehydroascorbic acid

Causes & Risk Factors for Dehydroascorbic acid

Diagnostic studies for Dehydroascorbic acid

Treatment of Dehydroascorbic acid

Continuing Medical Education (CME)

CME Programs on Dehydroascorbic acid

International

Dehydroascorbic acid en Espanol

Dehydroascorbic acid en Francais

Business

Dehydroascorbic acid in the Marketplace

Patents on Dehydroascorbic acid

Experimental / Informatics

List of terms related to Dehydroascorbic acid


Chemistry

Dehydroascorbic acid (DHA) is an oxidized form of ascorbic acid. It is actively imported into the endoplasmic reticulum of cells and generates the oxidative potential found there. Protein disulfide isomerases are known to reduce DHA back to ascorbic acid, oxidizing their disulfide bonds in the process. Therefore L-dehydroascorbic acid is a vitamin C compound much like L-ascorbic acid. Oxidized forms of esterified ascorbic acids can be numbered at C(5) or C(6) atoms and the (free) chemical radical semi-dehydroascorbate or semidehydro ascorbic acid (SDA) to the group of dehydroascorbic acids.

Physiological Significance

Top: ascorbic acid
(reduced form of Vitamin C)
Bottom: dehydroascorbic acid
(oxidized form of Vitamin C)

General significance

Although there exists a transporter for Vitamin C, it is mainly present in specialized cells, whereas the glucose transporters, most notably GLUT1, ensure in most cells of the body the transport of vitamin C (in its oxidized form, DHA)[1] where it is required as an enzyme cofactor and an intracellular antioxidant, after it is recycled back to ascorbic acid (see Transport to mitochondria).

Transport to mitochondria

Vitamin C accumulates in mitochondria, where most of the free radicals are produced, by entering through the glucose transporters, GLUT1. It is the oxidized form (dehydroascorbic acid) that is transported by GLUT1, not the reduced form (ascorbic acid). Ascorbic acid protects the mitochondrial genome and membrane.[1]

Transport to the brain

Vitamin C does not enter the brain.[2] However, the brain is one of the organs which has the greatest concentrations of vitamin C. It is dehydroascorbate that is transported through the blood-brain barrier via de GLUT1 transporters. DHA is then converted to vitamin C. Administration of dehydroascorbic acid confers protection from neuronal injury following stroke (ischemic stroke).

The lack of increased intracerebral hemorrhage (ICH) after the delayed administration of DHA after ischemia confers two significant advantages to this agent, which could lead to its utility at clinically relevant time points. As a well-tolerated agent, it could be given safely in the field before arrival in the hospital and the definitive diagnosis of stroke. Furthermore, its low risk of increasing ICH when administered after stroke obviates the expenditure of valuable time within the therapeutic window by eliminating the prerequisite radiographic imaging studies. Taken together, a pharmacological strategy to increase cerebral levels of ascorbate in stroke has tremendous potential to represent the timely translation of basic research into a relevant therapy for thromboembolic stroke in humans.[2]

References

  1. 1.0 1.1 KC S, Carcamo JM, Golde DW (2005). "Vitamin C enters mitochondria via facilitative glucose transporter 1 (Glut1) and confers mitochondrial protection against oxidative injury". FASEB J. 19 (12): 1657–67. PMID 16195374.
  2. 2.0 2.1 Huang J, Agus DB, Winfree CJ, Kiss S, Mack WJ, McTaggart RA, Choudhri TF, Kim LJ, Mocco J, Pinsky DJ, Fox WD, Israel RJ, Boyd TA, Golde DW, Connolly ES Jr. (2001). "Dehydroascorbic acid, a blood-brain barrier transportable form of vitamin C, mediates potent cerebroprotection in experimental stroke". Proceedings of the National Academy of Sciences. 98 (20): 11720–11724. PMID 11573006.

See also

Nualart F, Rivas C, Montecinos V, Godoy A, Guaiquil V, Golde D, Vera J (2003). "Recycling of vitamin C by a bystander effect". J Biol Chem. 278 (12): 10128–33. PMID 12435736.

External links

Template:WH Template:WikiDoc Sources