3-Maleimidopropionic acid
[CAS# 7423-55-4]

Identification

• Classification: Chemical reagent >> Organic reagent >> Imide
• Name: 3-Maleimidopropionic acid
• Synonyms: N-(2-Carboxyethyl)maleimide
• Molecular Formula: C₇H₇NO₄
• Molecular Weight: 169.13
• CAS Registry Number: 7423-55-4
• EC Number: 616-069-0
• SMILES: C1=CC(=O)N(C1=O)CCC(=O)O

Properties

• Density: 1.5±0.1 g/cm³ Calc.^*
• Melting point: 103 - 106 °C (Expl.)
• Boiling point: 382.5±25.0 °C 760 mmHg (Calc.)^*
• Flash point: 185.1±23.2 °C (Calc.)^*
• Index of refraction: 1.565 (Calc.)^*

^* Calculated using Advanced Chemistry Development (ACD/Labs) Software.

Safety Data

• Hazard Symbols: GHS07 Warning
• Risk Statements: H315-H319-H335
• Safety Statements: P261-P264-P264+P265-P271-P280-P302+P352-P304+P340-P305+P351+P338-P319-P321-P332+P317-P337+P317-P362+P364-P403+P233-P405-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Skin irritation	Skin Irrit.	2	H315
Specific target organ toxicity - single exposure	STOT SE	3	H335
Eye irritation	Eye Irrit.	2	H319
Eye irritation	Eye Irrit.	2A	H319

Discovery and Applications

3-Maleimidopropionic acid, with the chemical formula C6H7NO4, is an organic compound that contains both a maleimide group and a carboxyl group. It is commonly used as a reagent in biochemical and chemical synthesis, particularly in the formation of conjugates for applications in biochemistry, molecular biology, and materials science.

The discovery and use of maleimides, including 3-maleimidopropionic acid, are rooted in their ability to form stable covalent bonds with thiol groups. The maleimide group is highly reactive toward thiols (–SH), making it an invaluable tool for linking proteins, peptides, or other molecules that contain thiol groups. This reactivity is key to its widespread use in the development of bioconjugates, which are hybrid molecules that combine biological molecules with other substances, such as drugs or diagnostic agents.

The structure of 3-maleimidopropionic acid features a maleimide ring (a five-membered ring containing both carbon and nitrogen atoms) attached to a propionic acid chain. This structure provides two functional groups that facilitate its use in conjugation reactions: the maleimide group, which reacts with thiols, and the carboxyl group, which can be used for further derivatization or conjugation.

In biochemistry, 3-maleimidopropionic acid is often used to modify proteins or peptides by attaching them to other molecules. This process is important in the creation of targeted drug delivery systems, where the molecule can be conjugated to a drug or a targeting agent, thus improving the specificity and efficacy of the treatment. The carboxyl group in the structure can also be used to link the compound to solid supports or to other biomolecules, making it a versatile tool in protein chemistry.

The compound is also employed in the preparation of biosensors and diagnostic assays. By linking biomolecules to a surface via 3-maleimidopropionic acid, it is possible to develop systems that can detect specific biomolecular interactions. For instance, the compound may be used in the development of enzyme-linked immunosorbent assays (ELISA) or other affinity-based detection systems, where the stable attachment of biomolecules to a sensor surface is crucial for sensitivity and specificity.

In addition to its uses in biology and chemistry, 3-maleimidopropionic acid is utilized in materials science for the development of functional materials. The ability to conjugate thiol-containing compounds to various surfaces, such as nanoparticles or polymers, allows for the creation of materials with specific properties, such as increased stability, biocompatibility, or responsiveness to external stimuli. This makes it an important component in the development of new materials for medical devices, diagnostics, and drug delivery systems.

The reactivity of the maleimide group with thiols is highly specific, which contributes to the utility of 3-maleimidopropionic acid in a wide range of applications. The maleimide-thiol bond is stable under a variety of conditions, including physiological pH, which makes it ideal for use in biological systems. Additionally, the carboxyl group provides further versatility by enabling coupling to a variety of other molecules or surfaces.

Safety precautions are important when handling 3-maleimidopropionic acid, as with any chemical that is reactive and used in bioconjugation processes. Proper laboratory techniques should be employed, including the use of gloves, eye protection, and appropriate waste disposal methods. The compound's reactivity with thiols means that it should be handled with care to avoid unwanted reactions.

In conclusion, 3-maleimidopropionic acid is a versatile and important chemical used primarily in the synthesis of bioconjugates and in the development of targeted therapies, diagnostic assays, and functional materials. Its reactivity with thiol groups enables it to play a crucial role in linking biomolecules, making it a valuable tool in both research and application within the fields of biochemistry, molecular biology, and materials science.