209977-51-5Relevant articles and documents
ENZYMIC SYNTHESIS OF DISACCHARIDES BY USE OF THE REVERSED HYDROLYSIS ACTIVITY OF β-D-GALACTOSIDASES
Ajisaka, Katsumi,Fujimoto, Hiroshi,Nishida, Hiroko
, p. 35 - 42 (1988)
D-Galactosyl disaccharides have been synthesized by utilizing the reversed hydrolysis activity of β-D-galactosidases from E. coli and from A. oryzae, respectively.In order to shift the equilibrium towards the formation of disaccharide, solutions of monosaccharides were circulated through columns of immobilized β-D-galactosidase and activated carbon in series.After 24 h, the disaccharides were eluted with aqueous 50 percent ethanol from the column of activated carbon and analyzed by h.p.l.c. and 13C-n.m.r. spectroscopy.In this way, β-D-galactosyl-D-glucose, β-D-galactosyl-2-acetamido-2-deoxy-D-glucose, and β-D-galactosyl-D-fructose were produced in yields of 6.0, 16.0, and 11.3 percent, respectively, when the immobilized β-D-galactosidase from E. coli was used.The possible mechanism of the synthesis of the disaccharides is discussed.
The Heyns rearrangement revisited: An exceptionally simple two-step chemical synthesis of D-lactosamine from lactulose
Wrodnigg, Tanja M.,Stuetz, Arnold E.
, p. 827 - 828 (1999)
Disaccharides containing D-glucosamine at the reducing end can be conveniently synthesized in good yields from O-glycosylated D-fructoses by the title reaction [Eq. (a)]. With all the disaccharides investigated, the method proceeded-presumably because of
Highly efficient enzymatic synthesis of Galβ-(1→3)-GalNAc and Galβ-(1→3)-GlcNAc in ionic liquids
Bayón, Carlos,Cortés, álvaro,Berenguer, José,Hernáiz, María J.
, p. 4973 - 4978 (2013/06/27)
Ionic liquids (ILs) have emerged as an alternative to conventional organic media due to their high thermal and chemical stability, negligible vapour pressure, non-flammability and easy recycling. In this context, this work assesses the catalytic activity of a β-galactosidase from Bacillus circulans ATCC 31382 (β-Gal-3-NTag) in the synthesis of β-(1→3)-galactosides using different ILs. A noticeably increase in activity, retaining total regioselectivity was found in the synthetic behaviour of B. circulans β-galactosidase in ILs as co-solvents and using a 1:5 molar ratio of donor (pNP-β-Gal):acceptor (GlcNAc or GalNac). Yields up to 97% of β-(1→3) with different ILs were found. These reactions take place without noticeable hydrolytic activity and with total regioselectivity, representing a considerable improvement over the use of aqueous buffer or conventional organic solvents. Furthermore, reaction scaling up and IL recovery and recycling are feasible without losing catalytic action. Molecular modelling studies performed predict a three-dimensional interaction at the active centre between the acceptor and the water-IL mixture, which could explain the results obtained.
Improved synthesis of disaccharides with Escherichia coli β-galactosidase using bio-solvents derived from glycerol
Pérez-Sánchez, María,Cortés Cabrera, álvaro,García-Martín, Héctor,Sinisterra, J. Vicent,García, José I.,Hernáiz, María J.
experimental part, p. 7708 - 7712 (2011/10/12)
A noticeably increase in activity, keeping total regioselectivity was found in the synthetic behaviour of Escherichia coli β-galactosidase in glycerol-based solvents using a 1:7 molar ratio of donor (pNP-β-Gal): acceptor (GlcNAc). Yields of up to 97% of β(1→6) with different solvents were found. These reactions take place without noticeable hydrolytic activity and with total regioselectivity, representing a considerable improvement over the use of aqueous buffer or conventional organic solvents. There is a clear dependence of the catalytic results on the solvent structure, which is analysed in terms of polarity and hydrophobicity.
