LNnT

Lacto-N-neotetraose  (LNnT, Galβ1-4GlcNAcβ1-3Galβ1-4Glc) ranks as the #2 neutral human milk oligosaccharide after 2'-FL, comprising 8-12% of total HMOs in mature breast milk and appearing as a white hygroscopic powder essential for Bifidobacterium-selective gut colonization and infant barrier function. This type 2 chain tetrasaccharide serves as universal precursor for Lewis X (LNFP III), sialyl-Lewis X, and difucosyl HMOs, demonstrating 3-5x Bifidobacterium bifidum/longum growth stimulation versus glucose while resisting Bacteroides/Clostridium hydrolysis; commercially scalable via engineered E. coli β4GalT1/β3GnT2 (>99% purity, FDA/EFSA GRAS), it inhibits ETEC/rotavirus adhesion 75-90% through competitive receptor mimicry, upregulates tight junctions (ZO-1↑2x/claudin↑1.5x), reduces NEC risk 45-65% via TLR4/NOD2 modulation, supports hippocampal neurogenesis through ganglioside mimicry, and exhibits gastric stability pH 2.5-9 with >800 g/L solubility and 60-month shelf life ideal for infant formula fortification up to 1.5 g/L. Appearance White to off-white amorphous hygroscopic powder. Ultra-high water solubility >800 g/L; clear solutions pH 6-8. Source 8-12% total HMOs mature human milk; 4-6% colostrum. Microbial fermentation: β4GalT1/β3GnT2 engineered E. coli. Molecular Weight and Structure 707.63 g/mol, formula C₂₆H₄₅NO₂₁ (CAS 13007-32-4). Galβ1-4GlcNAcβ1-3Galβ1-4Glc type 2 chain tetrasaccharide. Sugar Specificity B. bifidum/longum β3GnTase/β4GalTase (Km 0.2-0.8 mM). Precursor Leˣ (FucT3), sLeˣ (ST3Gal4); DC-SIGN ligand. Biological Activity 3-5x Bifidobacterium growth; ETEC/rotavirus inhibition 75-90%. ZO-1/claudin upregulation; NEC risk reduction 45-65%. Purity and Microbial Contamination ≥99% HPLC/NMR; lactose <0.3%, LNT <0.5%. Endotoxins <10 EU/g; total aerobes <10 CFU/g. Identity and Quality Control ¹H-NMR β-linkages verified; [α]D +33°→+27° mutarotation. LC-MS [M+H]⁺ 708.25; HPAEC Gal:GlcNAc:Glc 2:1:1. Shelf Life and Storage 60 months 25°C/60%RH sealed; indefinite -20°C. Hygroscopic—desiccated nitrogen storage. Applications Infant formula HMO (0.8-1.5 g/L); synbiotic formulations. Microbiota research; barrier function therapeutics. Key Characteristics Type 2 HMO scaffold; Bifido-selective distal colon targeting. Gastric-stable pH 2.5-9; Leˣ/sLeˣ universal precursor. Citation Links https://pubchem.ncbi.nlm.nih.gov/compound/121853 https://www.chemicalbook.com/ChemicalProductProperty_EN_CB1418097.htm https://www.tga.gov.au/resources/resources/compositional-guidelines/lacto-n-neotetraose https://www.medchemexpress.com/lacto-n-neotetraose.html https://www.fda.gov/media/100020/download https://pubchem.ncbi.nlm.nih.gov/compound/21670519 https://www.elicityl-oligotech.com/.../621-lacto-n-neotetraose... https://glycosmos.org/structure/LNnT https://www.cd-bioglyco.com/lacto-n-neotetraose https://en.wikipedia.org/wiki/Lacto-N-neotetraose