What Is Linkage Ratio

Polysaccharides are a class of natural polymers with critical biological functions. An essential step in elucidating the structure of unknown carbohydrates in a sample is accomplished by performing chain analysis on the sample. Linkage analysis determines which hydroxyl groups of each monosaccharide in a polysaccharide are linked to other substituents, in which the unconnected carbohydrate hydroxyl groups are labeled with methyl groups. The sample is hydrolyzed to monosaccharides and reduced to alditols, and finally, the free hydroxyl groups are acetylated. The synthesized partially methylated alditol acetates were analyzed by gas chromatography-mass spectrometry (GC-MS) or liquid chromatograph mass spectrometer (LC-MS) analysis. In addition, mass spectrometric fragmentation assigns monosaccharides whose exact structure is unknown, and the superior resolution of GC permits the separation of dozens of chemically similar carbohydrate derivatives. Differences in retention times distinguish different sugar groups and are a powerful analytical tool.

Fig.1 The process of linkage analysis of polysaccharides. (Galermo, et al.,2018)

Linkage Ratio Analysis Services at CD BioGlyco

Due to the structural diversity of polysaccharide molecules, their extraction, detection, and structural analysis are challenging. At CD BioGlyco, we have a one-stop polysaccharide solution that enables comprehensive analysis of polysaccharides by several methods, especially to clarify the structure and glycosidic bonding linkages. Further study of carbohydrate conformational relationships accelerates the development of glycomics, we offer the following methodological services:

• A method based on LC-MS/MS

At CD BioGlyco, we use LC-MS/MS methods for rapid and simultaneous relative quantification of glycosidic bonds for polysaccharide identification. We use ultra-high-performance liquid chromatography and triple-quadrupole mass spectrometry (UHPLC/QqQ-MS) in multiple reaction monitoring (MRM) modes. Permethylation and hydrolysis conditions, as well as LC-MS/MS parameters, were optimized, followed by UHPLC/MRM-MS analysis, and simultaneous monitoring of derivatized terminal, linear, dichotomous, and trichotomous monosaccharide linkages was achieved by mass spectrometry within a 15-minute run time. The speed and specificity of the method enable its application to the rapid glycosidic bond analysis of polysaccharides.

• Other methods

Our commonly used methods include GC-MS, high pH anion exchange chromatography with pulsed amperometric detection (HPAEC-PAD), capillary electrophoresis (CE), and high-performance liquid chromatography (HPLC) separation coupled with ultraviolet (UV) detection, which provides customers the most suitable detection strategies, and provides the accurate results.

Fig.2 The flowchart of linkage analysis. (CD BioGlyco, 2023)

Application

• Applied to Oligosaccharides, Monosaccharides, and Polysaccharide characterization.

Advantages

• Linkage ratio analysis with greater sensitivity.
• The analytical technique with high resolution, high sensitivity, and high versatility.
• Professional team: tracking and guiding the whole process.

As a company focused on glycobiology, CD BioGlyco is equipped with professional researchers and advanced large-scale instruments. We offer high-quality Beta-Glucan Production, Quantification, and characterization services. Moreover, we provide high-sensitive DB Analysis, and DP/MW Analysis By SEC services. If you need our services, please contact us, and we will reply as soon as possible.

• DB Analysis
• DP/MW Analysis By SEC