Fumaric acid
From Wikipedia, the free encyclopedia
| Fumaric acid | |
|---|---|
 |
|
| General | |
| Common name | Fumaric acid |
| Systematic name | (E)-Butenedioic acid |
| Other names | trans-1,2-Ethylenedicarboxylic acid 2-Butenedioic acid Allomaleic acid Boletic acid Lichenic acid |
| Molecular formula | C4H4O4 |
| SMILES | OC(=O)C=CC(=O)O |
| Molar mass | 116.07 g/mol |
| Appearance | White solid |
| CAS number | [110-17-8] |
| Properties | |
| Density and phase | 1.635 g/cm³, solid |
| Solubility in water | 0.63 g/100 mL |
| Solubility | Alcohols |
| Melting point | 287 °C |
| Acidity (pKa) | pka1 = 3.03, pka2 = 4.44 |
| Thermodynamic data | |
| Standard enthalpy of formation É¢fH°solid |
? kJ/mol |
| Standard enthalpy of combustion É¢cH°solid |
? kJ/mol |
| Standard molar entropy S°solid |
? J.K−1.mol−1 |
| Hazards | |
| EU classification | Irritant (Xi) |
| R-phrases | R36 |
| S-phrases | S2 S26 |
| NFPA 704 | |
| Supplementary data page | |
| Structure and properties |
n, É√r, etc. |
| Thermodynamic data |
Phase behaviour Solid, liquid, gas |
| Spectral data | UV, IR, NMR, MS |
| Regulatory data | Flash point, RTECS number, etc. |
| Related compounds | |
| Related carboxylic acids | Maleic acid Succinic acid |
| Related compounds | Fumaryl chloride Fumaronitrile Dimethyl fumarate Iron(II) fumarate |
| Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) Infobox disclaimer and references |
|
Fumaric acid is the chemical compound with the formula HO2CCH=CHCO2H. This colorless crystalline compound is one of two isomeric unsaturated dicarboxylic acids, the other being maleic acid wherein the carboxylic acid groups are cis. It has a fruit-like taste.
Contents |
[edit] Biology
Fumaric acid is found in fumitory (Fumaria officinalis), bolete mushrooms (specifically Boletus fomentarius var. pseudo-igniarius), lichen, and Iceland moss.
Related to malic acid, the ionized form of fumaric acid, fumarate, is used by cells (in the TCA cycle) to produce energy from food. Human skin naturally produces fumaric acid when exposed to sunlight.
[edit] Medicine
Fumaric acid esters are sometimes used to treat psoriasis, as it has been suggested that the condition is caused by an impairment of fumaric acid production in the skin. A starting dose is 60-105 mg daily, which may be gradually increased to as much as 1,290 mg per day. Side effects include kidney or gastrointestinal disorders, as well as skin flushing; these are mainly caused by excess intake. Decreased white blood cell counts have been reported with prolonged use.
[edit] Food
Fumaric acid is a food acidulent used since 1946 because it is non-toxic. It is generally used in beverages and baking powders for which requirements are placed on purity, such as Welch's Grape Drink. It is generally used as a substitute for tartaric acid and occasionally in place of citric acid, at a rate of 1.36 g of citric acid to every 0.91 grams of fumaric acid for the same taste. It is a common component of food additives and dietary supplements, and is sometimes used as a substitute for tartaric acid in beverages or baking powder. It is also used in candy, similarly to the way malic acid is used.
[edit] Chemistry
Fumaric acid is inexpensive, so it is typically purchased rather than prepared. It was first prepared from bromosuccinic acid.[1] A traditional synthesis involves oxidation of furfural (from the processing of maize) using sodium chlorate in the presence of a vanadium-based catalyst.[2]
The chemical properties of fumaric acid can be anticipated from its component functional groups. This weak acid forms a diester, it undergoes additions across the double bond, and it is an excellent dienophile.
[edit] Other uses
Fumaric acid is used in the manufacture of polyester resins and polyhydric alcohols and as a mordant for dyes.
[edit] Safety
Fumaric acid converts to the irritant maleic anhydride upon partial combustion.
[edit] References
- ^ Volhard, J. "Darstellung von Maleïnsäureanhydrid" Justus Liebig's Annalen der Chemie 1892, volume 268, page 255-6. DOI: 10.1002/jlac.18922680108
- ^ Milas, N. A. "Fumaric Acid" Organic Synthesis 1943, Collective Volume 2, page 302. http://www.orgsyn.org/orgsyn/pdfs/CV2P0302.pdf
[edit] See also
- Dermatology
- Photosynthesis
- Maleic acid, the cis-isomer of fumaric acid
