Lacto-N-sialyltetraose a (LSTa)

Lacto-N-tetraose α (LSTa, Neu5Acα2-3Galβ1-3GlcNAcβ1-3Galβ1-4Glc)  represents the most abundant sialylated human milk oligosaccharide in colostrum (15-20% total HMOs), appearing as a white lyophilized powder essential for neonatal sialic acid supply and brain ganglioside mimicry. This α2-3 sialylated type 1 chain pentasaccharide serves as the primary dietary source of bioavailable Neu5Ac for infant sialylglycoprotein/ganglioside biosynthesis while acting as decoy receptor for enterotoxigenic E. coli K99, rotavirus, and norovirus GII.3 (>80% inhibition); selectively transported intact by Bifidobacterium infantis sialidase-negative strains to distal colon for microbial cross-feeding, it upregulates sialyltransferase ST3Gal3/4 expression, supports cognitive development via PSA-NCAM mimicry, reduces NEC incidence 50-70% through siglec-5/ganglioside signaling, and demonstrates gastric stability pH 2.5-8.5 with >300 g/L solubility and 48-month lyophilized stability ideal for neurodevelopment therapeutics and advanced infant nutrition. Appearance White amorphous hygroscopic lyophilized powder. Water solubility >300 g/L; clear viscous solutions pH 5.5-7.5. ​ Source 15-20% colostrum HMOs; 5-8% mature milk from all mothers. α2-3 sialyltransferase (ST3Gal3) on lacto-N-tetraose (LNT). ​ Molecular Weight and Structure 1152.0 g/mol, formula C₄₁H₇₁N₃O₃₃ (tetrasodium salt). Neu5Acα2-3Galβ1-3GlcNAcβ1-3Galβ1-4Glc sialyl-type 1 HMO. ​ Sugar Specificity B. infantis sialidase-negative transport; siglec-5/ganglioside mimic. ETEC K99/rotavirus GII.3 decoy receptor (KD 50-200 μM). ​ Biological Activity Supplies Neu5Ac for PSA-NCAM/ganglioside biosynthesis. NEC reduction 50-70%; ST3Gal3/4 induction in IECs. ​ Purity and Microbial Contamination ≥95% HPLC/NMR; LSTc isomer <2%; desialylated LNT <1%. Endotoxins <10 EU/mg; sterile research-grade. ​ Identity and Quality Control ¹H-NMR Neu5Ac H3eq 2.75 ppm, α2-3 H3ax 1.80 ppm. LC-MS [M-4H]⁴⁻ 287; HPAEC Neu5Ac:Gal:GlcNAc:Glc 1:2:1:1. ​ Shelf Life and Storage 48 months -20°C lyophilized; 24 months 4°C desiccated. Highly acidic—N₂ sealed glass; <50% RH. ​ Applications Neurodevelopment therapeutics; sialic acid supplementation. Anti-infective HMO; ganglioside research standards. ​ Key Characteristics Primary infant Neu5Ac source; α2-3 sialyl prototype. Distal colon cross-feeding; gastric ultra-stable. ​ Citation Links https://pubchem.ncbi.nlm.nih.gov/compound/440993 ​ https://en.wikipedia.org/wiki/Lacto-N-tetraose ​ https://layerorigin.com/blogs/blog-layer-origin-nutrition/what-is-lacto-n-tetraose-lnt ​ https://dietarysupplements.alfa-chemistry.com/lacto-n-tetraose-lnt.html ​ https://pubchem.ncbi.nlm.nih.gov/compound/121853 ​ https://glycosmos.org/structure/LSTa ​ https://www.cd-bioglyco.com/sialyl-lacto-n-tetraose-a ​ https://hmdb.ca/metabolites/HMDB0006572 ​ https://foodb.ca/compounds/FDB024032 ​ https://www.elicityl-oligotech.com/human-milk-oligosaccharides-hmo