Isomer Analysis

Isomer analysis refers to the process of identifying and qualitatively and quantitatively analyzing compounds (isomers) that have the same molecular formula but different structures. In chemical and biological research, isomers are compounds with the same chemical formula but different molecular structures or spatial arrangements. Due to subtle structural differences, isomers often exhibit different physical and chemical properties, activity, and biological effects. They may also differ in terms of metabolism, activity, or toxicity within a biological system. Therefore, isomer analysis is of great significance in fields such as chemical synthesis, drug development, and food safety. Isomer analysis not only helps us understand the diversity of molecular structures but also provides an important experimental basis for new drug development, environmental monitoring, and molecular diagnostics. In drug development, the structural differences of isomers often determine the activity and side effects of drugs. Understanding the structure, properties, and interactions of isomers helps in the development of more precise and effective drugs. Especially in the analysis of chiral isomers, it is crucial for studies on biological activity and clinical applications, as the efficacy and safety of many drugs depend on their chiral structure.

 

1. Common Types and Classifications of Isomers

Isomers are compounds with the same molecular formula but different chemical structures. Isomers are generally divided into two major categories:

1. Conformational Isomers

These isomers can interconvert by rotating around a single bond in the molecule, typically without altering the connectivity of the chemical bonds. The differences between conformational isomers are usually minor, and they can interconvert under different temperature or solvent conditions. The most common examples are the different conformations of cycloalkanes.

 

2. Configurational Isomers

Configurational isomers are those that cannot interconvert even by rotating bonds within the molecule. The main types of configurational isomers include:

(1) StereoisomersIsomers with the same sequence of bonded atoms but different spatial arrangements.

(2) Geometric IsomersCommonly found in compounds with double bonds or ring structures, such as cis and trans isomers.

(3) EnantiomersIsomers that are mirror images of each other, typically possessing different biological activities.

(4) DiastereomersStereoisomers that are not mirror images, usually having different physical and chemical properties.

Due to structural differences, isomers may exhibit different chemical reactivities, solubilities, toxicities, and biological activities.

 

2. Methods of Isomer Analysis

Isomer analysis requires the use of high-precision and high-resolution techniques to distinguish between different isomers and determine their structures.

1. Mass Spectrometry (MS)

Mass spectrometry can infer molecular structures based on the mass-to-charge ratio of molecular fragments. For isomer analysis, mass spectrometry can distinguish different isomers, especially when analyzing isomers with the same molecular formula or different structures. High-resolution mass spectrometry can provide greater precision to help distinguish isomers with very small mass differences. The choice of ion source (such as electrospray ionization source, chemical ionization source) can affect the sensitivity and selectivity of the analysis, especially in complex samples, enhancing the ability to identify isomers.

 

2. Nuclear Magnetic Resonance (NMR)

Nuclear Magnetic Resonance (NMR) can provide information about the relationships between atoms within a molecule. Through NMR analysis, detailed structural information of isomers can be obtained, including the configuration of chiral centers, the positions of hydrogen or carbon atoms, and stereochemical information within the molecule. NMR is particularly suitable for the analysis of optical isomers, especially for the quantitative analysis of chiral molecules.

 

3. High-Performance Liquid Chromatography (HPLC)

High-Performance Liquid Chromatography (HPLC) is widely used for the separation and analysis of isomers in chemical samples, especially structural isomers and chiral isomers. By selecting appropriate columns and mobile phases, HPLC can effectively separate isomers and, when combined with other detection methods (such as UV absorption, fluorescence detection, or mass spectrometry), provide precise qualitative and quantitative analyses.

 

4. Polarimetry

For chiral isomers, polarimetry is a common method for analyzing their optical rotation properties. Different optical isomers rotate polarized light at different angles, and by measuring the optical rotation, chiral isomers can be distinguished and quantified. Polarimetry is often used for quality control of drugs, especially for monitoring the quality of chiral drugs.

 

5. Gas Chromatography (GC)

Gas chromatography can effectively separate isomers in volatile compounds, especially suitable for analyzing volatile chemicals with low molecular weight. GC is widely used in environmental analysis and food science, efficiently detecting isomers and providing quantitative data.

 

6. Fourier Transform Infrared Spectroscopy (FTIR)

Fourier Transform Infrared Spectroscopy (FTIR) infers molecular structure by analyzing the characteristic wavelengths of infrared light absorbed by molecules. FTIR can be used to analyze changes in functional groups within isomers, helping to determine the presence of different isomers, especially for qualitative analysis of structural isomers.

 

Biotage BioSciences provides comprehensive isomer analysis services, covering various advanced technology platforms such as mass spectrometry, nuclear magnetic resonance, and high-performance liquid chromatography. Whether it's structural isomers, optical isomers, or geometric isomers, we can provide precise and reliable analysis results. Please contact us, and we will be dedicated to providing you with high-quality isomer analysis services.

 

Biotage BioSciences - Characterization of Bioproducts, a high-quality service provider for multi-omics biomolecular mass spectrometry detection

 

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