What Is Fumaric Acid?
Fumaric acid is the simplest unsaturated dicarboxylic acid and is widely found in nature. It is a colorless crystalline powder with no odor but a strong sour taste. Industrially, fumaric acid is mainly produced by isomerizing maleic acid, a geometric isomer of fumaric acid.
Physicochemical Properties of Fumaric Acid
1. Name
English name: fumaric acid
IUPAC name: (2E)-but-2-enedioic acid
2. Molecular Formula
C4H4O4
3. Molecular Weight
116.07 4. melting point
4. Melting Point
300-302℃ (in sealed tube)
5. Solvent Solubility
Soluble in ethanol, insoluble in water, insoluble in benzene
Characteristics and Uses of Fumaric Acid
1. Use as a Fungicide
This compound is used as a disinfectant for fresh food due to its bactericidal properties. Its mechanism of action is as follows.
Fumaric acid’s mechanism of action as a fungicide:
- The carboxyl group is taken into the bacteria in a non-resolved state.
- The dissociation of the carboxyl group in the cytoplasm lowers the pH of the cytoplasm.
- As a result of (2) above, enzyme activity in the cytoplasm decreases, inducing metabolic abnormalities and killing the bacteria.
2. Examples of Use in the Food Industry, Livestock Industry, and Medical Field
Fumaric acid is recognized as safe as a food additive, and is used as an acidulant, expander, pH adjuster, and seasoning. In the livestock and agricultural fields, fumaric acid is used as an additive in feed and as a fungicide and algaecide for plants. In the industrial field, it is used as a raw material for synthetic resins and dyes. In the medical field, fumaric acid esters made from fumaric acid are being studied for their effectiveness in treating psoriasis.
3. Role in the body
Fumaric acid plays an important role in the energy production process of organisms that breathe oxygen. Specifically, it exists as an intermediate in the citric acid circuit, where it is produced from succinic acid and converted to malic acid.
Differences in Chemical Properties Between Fumaric Acid and Maleic Acid
Fumaric acid has geometric isomers. The trans form is fumaric acid and the cis form is maleic acid.
Interestingly, the chemical properties of these compounds are very different. Specifically, fumaric acid, the trans form, is less prone to intramolecular dehydrocondensation than maleic acid, and its solubility in water is much lower than that of maleic acid. These differences in properties can be explained by the steric positioning of the two carboxyl groups in these isomers. Please refer to the following article for a detailed explanation of this principle.