Identification and synthesis of a trisaccharide produced from lactose by transgalactosylation.
Enzymatic transgalactosylation of lactose by means of Streptococcus thermophilus, subspecies DN-001065, led to a mixture of D-galactose (approximately 4%), D-glucose (approximately 15%), lactose (approximately 51%), minor disaccharides (6%), trisaccharides (approximately 20%) and tetrasaccharides (3%). The major trisaccharide (approximately 16%) was identified by NMR spectroscopy and chemical synthesis as being the known beta-D-galactopyranosyl-(1-->3)-beta-D-galactopyranosyl-(1-->4)-D-glucos e (3'-beta-D-galactopyranosyl-lactose). It was purified from a mixture of peracetylated oligosaccharides by column chromatography followed by deacetylation. For the first time, 3'-beta-D-galactopyranosyl-lactose has been obtained on the 1 g scale, by resorting to simple techniques and equipment. NMR spectra have been unambiguously assigned.
Perrin
V
V
Université Claude-Bernard Lyon I, Villeurbanne, France.
Fenet
B
B
Praly
J P
JP
Lecroix
F
F
Ta
C D
CD
D002240:Carbohydrate Sequence; D005690:Galactose / Q000378:metabolism; D005947:Glucose / Q000737:chemistry; D007785:Lactose / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D008969:Molecular Sequence Data; D014312:Trisaccharides / Q000138:chemical synthesis* / Q000737:chemistry*
D014312:Trisaccharides; C410294:galactopyranosyl-(1-3)-galactopyranosyl-(1-4)-glucose; D005947:Glucose; D007785:Lactose; D005690:Galactose