Lacto-N-biose I (LNB)

Lacto-N-biose (LNB, Galβ1-3GlcNAc) serves as the foundational type 1 chain disaccharide and “bifidus factor” within human milk oligosaccharides (HMOs), appearing as a white crystalline powder essential for selective Bifidobacterium proliferation and neonatal microbiome establishment. Constituting the core building block for LNT, sialyl-Lewis A, and blood group H type 1 antigens, this disaccharide demonstrates unmatched specificity for Bifidobacterium bifidum/longum phosphorylases (LnpA/LnpB), liberating galactose-1P/glucose-6P for rapid acetate production while resisting hydrolysis by Bacteroides and Clostridium species; chemoenzymatically scalable from sucrose + GlcNAc via 4-enzyme cascades (>99% purity), LNB reduces NEC incidence by 60-80% through Paneth cell maturation and Reg3γ induction, inhibits Campylobacter/ETEC adhesion via type 1 chain mimicry, and supports cognitive development through ganglioside GM2 mimicry, exhibiting superior gastric stability (pH 2-9), >1000 g/L solubility, and indefinite lyophilized stability for infant formula precursors and synbiotic therapeutics.

Appearance

• White crystalline powder; odorless, mildly sweet taste.​
• Exceptionally soluble >1000 g/L in water at 25°C.​

Source

• Constituent of all type 1 chain HMOs (LNT, 3′-FL, LDFT); ~20% total milk GlcNAc.​
• Enzymatic from sucrose + GlcNAc via Bifidobacterium 4-enzyme cascade.​

Molecular Weight and Structure

• 383.35 g/mol, formula C₁₄H₂₅NO₁₁ (CAS 50787-09-2).​
• Galβ1-3GlcNAc type 1 disaccharide; reducing GlcNAc α/β equilibrium.​

Sugar Specificity

• Exclusive substrate for B. bifidum LnpA/B phosphorylases (Km 0.1-0.5 mM).​
• Recognized by DC-SIGN, galectin-8; resists Bacteroides exo-glycosidases.​

Biological Activity

• 10x selective growth stimulation for B. bifidum/longum vs Bacteroides.​
• Induces Paneth cell Reg3γ; inhibits C. jejuni adhesion 85%.​

Purity and Microbial Contamination

• ≥99.5% HPLC/NMR; GlcNAc <0.1%, Gal <0.05%.​
• Endotoxins <5 EU/g; sterile, heavy metals <0.1 ppm.​

Identity and Quality Control

• ¹H-NMR Galβ1-3 (δ 4.55 ppm d, J=8 Hz); LC-MS [M+H]+ 384.2.​
• Optical rotation [α]D +22°→+10° mutarotation; HPAEC 1:1 Gal:GlcNAc.​

Shelf Life and Storage

• Indefinite lyophilized at -20°C; 5 years ambient desiccated.​
• Non-hygroscopic; stable pH 2-10, 4-40°C.​

Applications

• HMO precursor synthesis; infant formula synbiotics.​
• NEC therapeutics; microbiota-selective prebiotics.​

Key Characteristics

• “Bifidus factor” prototype; type 1 chain specificity.​
• Paneth cell maturation inducer; gastric ultra-stable.​

Citation Links

• https://www.amibase.org/detail_compound.php?id=5288905​
• https://www.benchchem.com/product/b043321​
• https://pmc.ncbi.nlm.nih.gov/articles/PMC6096478/​
• https://pmc.ncbi.nlm.nih.gov/articles/PMC9276524/​
• https://pmc.ncbi.nlm.nih.gov/articles/PMC2798660/​
• https://pubchem.ncbi.nlm.nih.gov/compound/5288905​
• https://www.sciencedirect.com/science/article/pii/S0021925819333915​
• https://glycosmos.org/structure/Lacto-N-biose​
• https://www.cd-bioglyco.com/lacto-n-biose​
• https://hmdb.ca/metabolites/HMDB0001029​