Chem Explorers

Succinic Acid: From Metabolism to Eco-Friendly Applications

Succinic Acid: A Comprehensive Guide to Its Structure, Properties, and Importance in Metabolism

Succinic acid is a dicarboxylic acid with the molecular formula C4H6O4. It was first discovered by the German scholar Georgius Agricola in the early 16th century, who referred to it as “spiritus urinae.” Over time, succinic acid has found numerous applications in various industries, including food, pharmaceuticals, and agriculture.

This comprehensive guide will provide an overview of succinic acid, its structure, physical and chemical properties, and role in metabolism, as well as its health benefits and drug interactions.

Succinic Acid Structure and Molecular Formula:

Succinic acid has a tetrahedral molecular geometry and consists of two carboxyl groups (COOH) on each end of a four-carbon chain.

It is also known as butanedioic acid due to its four-carbon chain. The molecular formula of succinic acid is C4H6O4, with a molar mass of 118.09 g/mol.

Historical Background and Production Methods:

Succinic acid was initially obtained via distillation of amber, a fossilized tree resin. However, in the contemporary era, petrochemical technology is widely used for its production.

Succinic acid can be manufactured through the anaerobic fermentation of glucose, fructose, or sucrose, or through synthetic methods using maleic anhydride. Nowadays, succinic acid production has grown for its use in eco-friendly applications due to its renewability and abundance.

Physical and Chemical Properties:

Succinic acid is a white, crystalline solid with a melting point of 185 °C and a boiling point of 235-238 °C. It has a sweet taste and is soluble in water and ethanol, whereas it is insoluble in non-polar solvents such as ether and chloroform.

Succinic acid reacts with strong oxidizing agents to produce carbon dioxide and water. It also reacts with alcohols and amines to form monoesters and amides of succinic acid, respectively.

Role in Intermediary Metabolism:

Succinic acid plays a significant role in the intermediary metabolism of humans and other organisms. It is a key component of the Krebs cycle, also known as the citric acid cycle or the tricarboxylic acid (TCA) cycle.

The Krebs cycle is a fundamental part of aerobic respiration, and it involves the conversion of pyruvate to carbon dioxide through a series of chemical reactions, which yields ATP, FADH2, and NADH. Succinic acid is generated via the oxidation of succinate dehydrogenase, an enzyme that transfers electrons to FAD (flavin adenine dinucleotide) from succinate, forming fumarate.

Health Benefits and Drug Interactions:

Succinic acid has been recognized as a beneficial natural antibiotic for infections. It has also been found to enhance the immune system and promote neural system recovery in cases of stroke or brain injury.

Additionally, succinic acid is used to treat chronic fatigue syndrome, while also improving metabolism on the whole. On the other hand, it has been reported to interact with certain drugs like insulin, glucagon, and barbiturates, and therefore, needs monitoring while using them.


Succinic acid is a crucial molecule in biological and organic chemistry. Its structure, properties, and role in the intermediary metabolism have been studied extensively and have led to its applications in several industries.

Understanding its health benefits and drug interactions is also essential in advocating its use. Therefore, continued research into succinic acid and its formation will help to advance our knowledge even further.

Methods of Synthesis of Succinic Acid

Succinic acid is an essential organic acid used in various fields such as the food, chemical, and pharmaceutical industries. The current demand for succinic acid led to the development of many methods of synthesis, each with its own advantages and disadvantages.

This article provides an overview of the most common methods of synthesis, including their mechanisms.

Reduction of Maleic Acid

The reduction of maleic acid is one of the widely used methods of succinic acid preparation. Maleic acid is a cis-unsaturated dicarboxylic acid with a double bond between two carbon atoms.

To reduce maleic acid to succinic acid, hydrogen gas is passed over nickel catalysts at elevated temperatures and pressures. The double bond, referred to as a pi bond, is broken using hydrogen atoms, leading to the formation of a cis-unsaturated dicarboxylic acid.

The reaction involved can be represented as follows:

Cis-Butenedioic acid + H2 → Succinic acid

As the reaction can generate a cyclic intermediate, the use of certain solvents and catalysts help to restrain this phenomenon. The process can be conducted in a batch or continuous mode, getting a high yield of moderate purity.

Cyanide Method

The cyanide method is another approach to synthesize succinic acid. This method involves the reaction of 1,2-di-bromoethane with sodium cyanide.

The reaction produces 1,2-dicyanoethane, which is hydrolyzed to diaminobutyric acid. The hydrolysis of diaminobutyric acid leads to the formation of succinic acid.

This method also requires the use of a reducer, such as sodium borohydride. The reaction involved can be represented as follows:

1,2-bromoethane + NaCN → 1,2-dicyanoethane + NaBr

1,2-dicyanoethane + H2O → Diaminobutyric acid

Diaminobutyric acid + NaOH + H2O → Succinic acid

Although this method has an excellent yield, it is a bit complicated due to the use of cyanides, leading to its limited applicability.

Reduction of Tartaric Acid

Another approach to preparing succinic acid is by the reduction of tartaric acid. Tartaric acid is a naturally occurring dicarboxylic acid found in many fruits.

Its reduction using hydrogen iodide and red phosphorous leads to the formation of succinic acid. However, the reduction of tartaric acid is less commonly used than the reduction of maleic acid as it requires special conditions, leading to low yield and purity.

The reaction can be represented as follows:

Tartaric acid + 3 HI + P → Succinic acid + 3 I2 + CO2

Characterization and Analysis of Succinic Acid

Fourier Transform Infrared Spectroscopy (FTIR)

FTIR is a common technique to analyze the structure of organic compounds such as succinic acid. FTIR works on the principle that molecules absorb light at specific wavelengths, which is related to the functional groups in the sample.

The spectrum produced contains characteristic peaks that confirm the presence of specific functional groups. When an FTIR spectrum of succinic acid is produced, characteristic absorption bands at approximately 1730, 1460 and 1385 cm-1 are related to the C=O stretching, CH bending of CH2, and CO stretching, respectively.

By analyzing the FTIR spectrum of succinic acid, the functional groups present, and ultimately the structure of the sample can be established.

Other Techniques

Besides FTIR, other techniques exist that have proven valuable in the characterization of succinic acid. Raman spectroscopy, for instance, employs a laser source and detects the vibration of molecular bonds in a sample, ultimately producing an Raman-active band.

The intensity of the band relates to the concentration of the bond. Scanning electron spectroscopy (SEM) is also useful in analysing succinic acid.

This method involves directing electron beams to a sample, producing information regarding its morphology. SEM is valuable in determining the purity of the sample, the roughness of its surface and the crystal shape.


Succinic acid is an essential organic compound utilized in various industries. It can be synthesized through a variety of methods, the most common being the reduction of maleic acid using hydrogen gas over nickel catalysts and the cyanide method.

Once synthesized, succinic acid is characterized using several analysis techniques, including FTIR, Raman spectroscopy and SEM. By analyzing the spectra produced, the structure of the sample can be determined along with its purity, morphology, and crystal shape.

Thus, the comprehensive understanding of the methods of synthesis and their analysis techniques aids in producing succinic acid of high purity and quality.

Uses of Succinic Acid

Succinic acid is an essential dicarboxylic acid that is used widely in various fields, including food, pharmaceuticals, and the chemical industry. With the increased demand for eco-friendly solutions, the use of succinic acid has gained significant interest, largely due to its biodegradability and renewability.

In this article, we explore the use of succinic acid across various applications.

Industrial and Commercial Applications

Succinic acid has gained significant importance in the food industry as a food additive. Its sour taste makes it an ideal acidulant, especially in candy, condiments, and carbonated drinks, among others.

Succinic acid, being a GRAS substance, does not have any adverse health effects on human physiology and is approved by the U.S. Food and Drug Administration (FDA). It is also used as a flavor enhancer in food products.

The pharmaceutical industry uses succinic acid as a precursor for drug development. For instance, the di-ethyl ester of succinic acid is a key component in the form of a pharmaceutical intermediate known as alitretinoin, used to treat skin diseases such as psoriasis.

Succinic acid helps in the formation of carboxamide, carboxylate, and succinimide. Succinic acid also plays a role in the formulation of phenylethyl Malonic esters, which are useful in the production of antihistamines and tranquilizers, among others.

Succinic acid also speeds up the dissolution of poorly soluble drugs and can be used to develop sustained-release formulations. Succinic acid is also utilized in the production of biodegradable plastics, as it can serve as an intermediate precursor to polybutylene succinate (PBS), a biodegradable thermoplastic polymer.

PBS finds applications in packaging, automobiles, agriculture, and horticulture. This success can be attributed to the property of PBS, which is biodegradable under both aerobic and anaerobic conditions in nature, circumventing the obesity of landfills.

Environmental Benefits

Succinic acid plays a crucial role in reducing the carbon footprint of various industries. It has emerged as an essential renewable feedstock in the chemical industry, facilitating the production of biomaterials and other industrial products.

Succinic acid can be manufactured from biomass, including sugars, cellulose, and lignin. The fermentative process converts the metabolic products of various microorganisms, such as E. coli and yeast. This methodology is an attractive approach to utilizing renewable resources and reducing the dependency on non-renewable resources.

Another application that can be achieved through succinic acid is the use of metal catalysts to fix carbon dioxide using succinic acid. The ability of succinic acid to complex metal ions makes it an ideal candidate for this process, leading to the production of the corresponding metal succinate complexes.

These complexes are essential as they trap carbon dioxide, which would otherwise contribute to the greenhouse gases. The metal succinate complexes are used as catalysts in the production of methanol, which is a feedstock in the synthesis of several organic compounds.

This methodology creates an opportunity to utilize carbon dioxide, reducing the carbon footprint and promoting a sustainable environment.


Succinic acid has significant importance in various fields, including the food, pharmaceuticals, and chemical industries. The utilization of succinic acid in these industries has led to an increase in eco-friendliness, sustainable resources, and biodegradable plastics, thereby reducing the reliance on non-renewable and harmful resources.

The capacity of succinic acid complexes to sequester carbon dioxide makes it an essential precursor in this process. It is evident that the use of succinic acid has enormous potential to promote a sustainable environment and benefit multiple industries, and research in this field is growing in prominence.

In conclusion, succinic acid is a versatile compound with a wide range of applications in various industries. Its uses in food additives, pharmaceuticals, and biodegradable plastics highlight its significance in industrial and commercial settings.

Additionally, its renewable feedstock properties and role as a catalyst in chemical reactions offer environmental benefits. Succinic acid’s ability to contribute to sustainable practices and reduce carbon footprints makes it an important topic to explore further.

Understanding the diverse uses of succinic acid encourages the development of more sustainable and eco-friendly solutions in multiple industries.


  1. What are the industrial applications of succinic acid?

    Succinic acid is commonly used as a food additive and flavor enhancer, as well as a precursor in the pharmaceutical industry and in the production of biodegradable plastics.

  2. How does succinic acid benefit the environment?

    Succinic acid can be derived from renewable resources, reducing dependence on non-renewable resources. It can also be used as a catalyst to trap carbon dioxide and promote sustainable practices.

  3. What are the environmental advantages of using succinic acid in chemical reactions?

    Succinic acid can complex metal ions to trap carbon dioxide, reducing greenhouse gas emissions and promoting a more sustainable environment.

  4. How does succinic acid contribute to the production of biodegradable plastics?

    Succinic acid serves as an intermediate precursor in the production of polybutylene succinate (PBS), a biodegradable thermoplastic polymer used in various applications.

  5. Can succinic acid be used as a flavor enhancer in food products?

    Yes, succinic acid is commonly used as an acidulant and flavor enhancer in various food products, approved by the FDA for its safe consumption.

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