Fumaric acid or trans-butenedioic acid is an organic compound with the formula HO2CCH=CHCO2H. A white solid, fumaric acid occurs widely in nature. It has a fruit-like taste and has been used as a food additive. Its E number is E297.[
] The salts and are known as fumarates. Fumarate can also refer to the ion (in solution). Fumaric acid is the trans isomer of butenedioic acid, while maleic acid is the cis isomer.
Biosynthesis and occurrence
It is produced in
eukaryotic organisms from
succinate in complex 2 of the electron transport chain via the
enzyme succinate dehydrogenase.
Fumaric acid is found in fumitory ( Fumaria officinalis), bolete (specifically Boletus fomentarius var. pseudo-igniarius), lichen, and Iceland moss.
Fumarate is an intermediate in the citric acid cycle used by cells to produce energy in the form of adenosine triphosphate (ATP) from food. It is formed by the oxidation of succinate by the enzyme succinate dehydrogenase. Fumarate is then converted by the enzyme fumarase to malic acid.
Human skin naturally produces fumaric acid when exposed to sunlight.[ Active Ingredients Used in Cosmetics: Safety Survey, Council of Europe. Committee of Experts on Cosmetic Products]
Fumarate is also a product of the urea cycle.
Uses
Food
Fumaric acid has been used as a food acidulant since 1946. It is approved for use as a food additive in the EU,
[UK Food Standards Agency: ] USA
[US Food and Drug Administration: ] and Australia and New Zealand.
[Australia New Zealand Food Standards Code] As a
food additive, it is used as an acidity regulator and can be denoted by the
E number E297. It is generally used in beverages and
for which requirements are placed on purity. Fumaric acid is used in the making of
as a food preservative and as the acid in leavening.
It is generally used as a substitute for
tartaric acid and occasionally in place of
citric acid, at a rate of 1 g of fumaric acid to every ~1.5 g of citric acid, in order to add sourness, similarly to the way
malic acid is used. As well as being a component of some artificial vinegar flavors, such as "Salt and Vinegar" flavored potato chips,
it is also used as a
flocculation in stove-top pudding mixes.
The European Commission Scientific Committee on Animal Nutrition, part of DG Health, found in 2014 that fumaric acid is "practically non-toxic" but high doses are probably Nephrotoxicity after long-term use.[European Commission: ]
Medicine
Fumaric acid was developed as a medicine to treat the autoimmune condition
psoriasis in the 1950s in Germany as a tablet containing 3
, primarily dimethyl fumarate, and marketed as Fumaderm by
Biogen Idec in Europe. Biogen would later go on to develop the main ester, dimethyl fumarate, as a treatment for multiple sclerosis.
In patients with relapsing-remitting multiple sclerosis, the ester dimethyl fumarate (BG-12, Biogen) significantly reduced relapse and disability progression in a phase 3 trial. It activates the Nrf2 antioxidant response pathway, the primary cellular defense against the cytotoxic effects of oxidative stress.
Other uses
Fumaric acid is used in the manufacture of
polyester and polyhydric alcohols and as a
mordant for dyes.
Fumaric acid can be used to make 6-methylcoumarin.
When fumaric acid is added to their feed, lambs produce up to 70% less methane during digestion.
Synthesis
Fumaric acid is produced based on
catalyst isomerisation of
maleic acid in aqueous solutions at low p
H. It precipitates from the reaction solution. Maleic acid is accessible in large volumes as a
hydrolysis product of maleic anhydride, produced by catalytic oxidation of
benzene or
butane.
[
]
Historic and laboratory routes
Fumaric acid was first prepared from succinic acid.[Volhard, J. "Darstellung von Maleïnsäureanhydrid" Justus Liebig's Annalen der Chemie 1892, volume 268, page 255-6. ] A traditional synthesis involves oxidation of furfural (from the processing of maize) using sodium chlorate in the presence of a vanadium-based catalyst.
Reactions
The chemical properties of fumaric acid can be anticipated from its component . This weak acid forms a diester, it undergoes bromination across the alkene,
Safety
The oral LD50 is 10g/kg.[
]
See also
External links
