3757-90-2Relevant articles and documents
The effects of organic solvents on the synthesis of galactose disaccharides using β-galactosidases
Finch, Paul,Yoon, Jung Hae
, p. 339 - 345 (1997)
The use of β-galactosidases from five different sources in syntheses through transglycosylation leads to 3-O-methyl allolactose, N-acetyllactosamine, N-acetylallolactosamine and Gal(β1-6)Gal. The yield and distribution of products depends on the source of the enzyme and on the reaction conditions, viz. the nature of added organic co-solvent. Yields of 3-O-methyl allolactose (47%), Gal(β1-6)Gal (6%), N-acetylallolactosamine (30%) were obtained in aqueous buffer with β-galactosidase from E. coli. The same reactions occurred at much lower rates in the presence of water-miscible organic solvents. With β-galactosidases from K. fragilis and A. oryzae, however, the synthesis of the above disaccharides occurred only in the presence of organic solvent (> 60% v/v triethyl phosphate, trimethyl phosphate or tetraglyme) but not in aqueous buffer solution. β-galactosidases from D. pneumoniae and B. circulans in systems incorporating organic solvent produced 3-O-methyl allolactose and N-acetyllactosamine in yields of 30-40%. The direct separation of oligosaccharides on a preparative scale can be achieved by Ca2+-ligand exchange chromatography. Ultrafiltration was also used for the efficient recycling of enzymes.
Glycosyl azides - An alternative way to disaccharides
Bojarova, Pavla,Petraskova, Lucie,Ferrandi, Erica Elisa,Monti, Daniela,Pelantova, Helena,Kuzma, Marek,Simerska, Pavla,Kren, Vladimir
, p. 1514 - 1520 (2008/09/17)
Glycosyl azides are shown to be efficient donors for β-galactosidases, β-glucosidases and α mannosidases. Only α-galactosidases do not cleave the respective glycosyl azide 1 and, moreover, they exhibit competitive inhibition (especially α-galactosidase fr
On the effect of the aglycon structure of three aryl β-D-galactosides on the yield and the regioselecttvity of the transglycolytic synthesis of N-acetyllactosamine
Vetere, Amedeo,Novelli, Lara,Paoletti, Sergio
, p. 515 - 521 (2007/10/03)
We examined the effect as donors of three aryl β-D-galactosides (i.e. p-nitrophenyl β-D-galactopyranoside, o-nitrophenyl β-D-galactopyranoside and phenyl β-D-galactopyranoside) on the regioselectivity and the yield of the synthesis of N-acetyllactosamine obtained from the transglycosylation reaction catalyzed by a crude preparation of β-D-galactosidase from Bacillus circulans at 25°C, 37°C and 55°C, respectively. Using p-nitrophenyl β-D-galactopyranoside the reaction results were fully regiospecific at all the temperatures considered: the maximum molar yield (74%) was obtained at an incubation temperature of 55°C Using o-nitrophenyl β-D-galactopyranoside as the donor the reaction was still highly regioselective and the maximum molar yield (50%) was achieved at an incubation temperature also of 55°C. Using phenyl β-D-galactopyranoside transglycolytic products appear only at an incubation temperature of 55°C but at very low molar yield (about 14%) and lower regioselectivity.
