Para-Lacto-N-neohexaose (Para-LNnH)

Para-Lacto-N-neohexaose (Para-LNnH, p-LNnH, CAS 64309-00-8) is a neutral hexasaccharide human milk oligosaccharide (HMO) analogue with a unique branched type-2 chain architecture: Galβ1-4GlcNAcβ1-3(Galβ1-4GlcNAcβ1-6)Galβ1-4Glc, featuring two LacNAc units extending from a central galactose without fucose or sialic acid modifications typical of core HMOs. This para-neo structure, biosynthesized by iterative β1-4 galactosyltransferase action on lacto-N-neotetraose (LNnT) scaffolds, occurs in trace levels in human milk (<0.05% total HMOs) but higher in bovine sources, serving as a model for poly-N-acetyllactosamine (poly-LacNAc) glycans on cell surfaces. Para-LNnH exhibits strong bifidoselectivity, preferentially metabolized by Bifidobacterium longum subsp. infantis via GH20/β-galactosidases, promoting gut colonization while resisting degradation by opportunistic pathogens lacking type-2 chain hydrolases. Its anti-adhesive properties stem from competitive binding to E. coli type-1 fimbriae and rotavirus VP4, reducing neonatal infection risk. Chemically synthesized for research, it functions as an LC-MS/MS standard in HMO profiling, prebiotic candidate for synbiotic formulas targeting microbiome dysbiosis, and probe in glycan arrays dissecting galectin-3/9 binding specificities for IBD therapeutics and cancer glycoimmunology.

Appearance

• White amorphous lyophilized powder.
• Stable non-hygroscopic solid for long-term storage.

Source

• Minor component in human/bovine milk; enriched in porcine colostrum.
• Chemoenzymatic synthesis via β4GalT-1 on LNnT core.

Molecular Weight and Structure

• Formula: C40H68N2O31; MW 1072.96 g/mol.
• Galβ1→4GlcNAcβ1→3[Galβ1→4GlcNAcβ1→6]Galβ1→4Glc (di-para type-2 LacNAc).

Sugar Specificity

• Type-2 chain selective for B. infantis ABC-transporters.
• Weak galectin-3 ligand; resistant to α-fucosidases.

Biological Activity

• Bifidogenic: 3-5x selective growth of B. infantis over Clostridium.
• Inhibits EPEC adhesion (IC50 5-10 mM); barrier-protective.

Purity and Microbial Contamination

• 90% by NMR/HPLC for lab standards.
• Endotoxin <0.1 EU/mg; bioburden <5 CFU/g.

Identity and Quality Control

• 1H-NMR (β4-linked anomeric ~4.55 ppm), HRMS (m/z 1073 [M+H]+).
• Sequential enzymatic digestion (β4/β3 galactosidases).

Shelf Life and Storage

• 3 years at -20°C lyophilized; solutions stable 3 weeks 4°C.
• Desiccated; avoid repeated freeze-thaw cycles.

Applications

• HMO analytics standards; synbiotic development.
• Glycobiology probes, infant formula R&D.

Key Characteristics

• Ultra water-soluble (>250 mg/mL); neutral poly-LacNAc mimic.
• Highly bifidoselective without pathogenic utilization.

Citation Links

• https://www.elicityl-oligotech.com/human-milk-oligosaccharides-hmo/279-para-lacto-n-neohexaose-para-lnnh-90-nmr.html
• https://pmc.ncbi.nlm.nih.gov/articles/PMC11370726/
• https://pubchem.ncbi.nlm.nih.gov/compound/22833594
• https://cymitquimica.com/cas/64309-00-8/
• https://www.chemicalbook.com/ChemicalProductProperty_EN_CB84657291.htm
• https://pubchem.ncbi.nlm.nih.gov/compound/Lacto-N-hexaose
• https://glyconnect.expasy.org/hmo/structures
• https://pmc.ncbi.nlm.nih.gov/articles/PMC9235823/
• https://www.bioglyco.com/para-lacto-n-hexaose
• https://bovinedb.ca/metabolites/BMDB0006628