Galα1-4Galβ1-4Glc 

Galα1-4Galβ1-4Glc (α1,4-galactobiose extended lactose, also called globotriaose precursor) represents a blood group B-related trisaccharide and Shiga toxin receptor analog, appearing as a white lyophilized powder essential for bacterial pathogenesis studies and glycan array standards. This linear carbohydrate, featuring rare α1-4 galactosyl linkage on the non-reducing Galβ1-4Glc core, serves as a high-affinity ligand for Shiga-like toxins (SLT-I/II) from E. coli O157:H7, blocking cytotoxicity in vitro; absent in humans but prevalent in porcine/bovine gut epithelium, it is chemoenzymatically synthesized (>98% purity) using α1-4 galactosyltransferase, demonstrating gastric stability, selective E. coli galactosidase hydrolysis, and roles in microbiome modulation, vaccine development against HUS, and cancer glycomimetic design, with multi-year ambient stability.

Appearance

• White to off-white amorphous lyophilized powder, odorless.
• Highly water-soluble (>300 g/L); forms clear solutions at neutral pH.​

Source

• Found in pig/small ruminant intestinal glycosphingolipids; microbial Gb3 precursors.
• Enzymatic synthesis via α4GalT on lactose using UDP-Gal donors.​

Molecular Weight and Structure

• 504.44 g/mol, formula C₁₈H₃₂O₁₆ (trisaccharide sodium salt).
• α-D-Galp-(1→4)-β-D-Galp-(1→4)-D-Glcp linear chain.​

Sugar Specificity

• Binds Shiga toxin B-subunits (KD 10⁻⁹ M); recognized by blood group B lectins.
• Hydrolyzed by α1-4 galactosidases from Bacteroides fragilis.​

Biological Activity

• Neutralizes SLT cytotoxicity; modulates Gb3 synthase pathway.
• Prebiotic for Gb3-utilizing probiotics; anti-adhesive against EHEC.​

Purity and Microbial Contamination

• ≥98% by HPLC/NMR; endotoxins <5 EU/mg post-purification.
• Sterile, heavy metals <1 ppm, moisture <4% lyophilized.​

Identity and Quality Control

• ¹H-NMR (α1-4 H-1 doublet 5.2 ppm); LC-MS [M+Na]⁺ 527.2.
• HPAEC-PAD confirms Gal:Gal:Glc 2:1:1 ratio.​

Shelf Life and Storage

• 36+ months at -20°C or ambient desiccated.
• Protect from humidity to avoid hydrolysis.​

Applications

• Shiga toxin neutralization assays; HUS vaccine adjuvants.
• Glycan microarray standards; blood group B research.​

Key Characteristics

• Ultra-high toxin affinity; heat-stable to 100°C.
• Linear scaffold for Gb4/Gb5 extensions.​

Citation Links

• https://www.vulcanchem.com/product/VC212766​
• https://pubchem.ncbi.nlm.nih.gov/compound/91859346​
• https://www.smolecule.com/products/s1817995​
• https://orthandex.com/info/56537.html​
• https://www.vulcanchem.com/product/vc212723​
• https://pubchem.ncbi.nlm.nih.gov/compound/91847904​
• https://www.chemsrc.com/en/cas/157240-67-0_654751.html​
• http://chemsynlab.com/en/product/41744-59-6.html​
• https://pmc.ncbi.nlm.nih.gov/articles/PMC2271034/​
• https://pubchem.ncbi.nlm.nih.gov/compound/Gal-alpha1-4-Gal-beta1-4-Glc