Synthesis of LeX and LeY Oligosaccharides with Azido-Type Spacer-Arms. Comparison of 3- and 4-Methoxybenzyl Groups as Key Temporary Protective Groups
摘要:
5-Azido-3-oxa-1-pentanol was prepared from 2-(2-chloroethoxy)ethanol and used as a spacer in the chemical synthesis of the trisaccharide beta-D-Gal-(1-->4)-[alpha-L-Fuc-(1-->3)]-GlcNAc and the tetrasaccharide alpha-L-Fuc-alpha-(1-->2)-beta-D-Gal-(1-->4)-[alpha-L-Fuc-(1-->3)]-GlcNAc that represent the epitopes defining the human blood groups Le(x) and Le(y). The classical 4-methoxybenzyl group and the remarably acid-stable 3-methoxybenzyl group were compared as temporary protective groups for position 3 at the glucosamine unit to circumvent the problems associated with the simultaneous presence of allyl and azido groups. The resulting oligosaccharides were coupled to proteins with high efficiency.
Synthesis of LeX and LeY Oligosaccharides with Azido-Type Spacer-Arms. Comparison of 3- and 4-Methoxybenzyl Groups as Key Temporary Protective Groups
摘要:
5-Azido-3-oxa-1-pentanol was prepared from 2-(2-chloroethoxy)ethanol and used as a spacer in the chemical synthesis of the trisaccharide beta-D-Gal-(1-->4)-[alpha-L-Fuc-(1-->3)]-GlcNAc and the tetrasaccharide alpha-L-Fuc-alpha-(1-->2)-beta-D-Gal-(1-->4)-[alpha-L-Fuc-(1-->3)]-GlcNAc that represent the epitopes defining the human blood groups Le(x) and Le(y). The classical 4-methoxybenzyl group and the remarably acid-stable 3-methoxybenzyl group were compared as temporary protective groups for position 3 at the glucosamine unit to circumvent the problems associated with the simultaneous presence of allyl and azido groups. The resulting oligosaccharides were coupled to proteins with high efficiency.
Efficient Preparation of Natural and Synthetic Galactosides with a Recombinant β-1,4-Galactosyltransferase-/UDP-4‘-Gal Epimerase Fusion Protein
作者:Ola Blixt、Jillian Brown、Melissa J. Schur、Warren Wakarchuk、James C. Paulson
DOI:10.1021/jo0057809
日期:2001.4.1
galactose to a variety of different glucose- and glucosamine-containing acceptors, and utilizes either UDP-galactose or UDP-glucose as donor substrates. A crude lysate from Escherichia coli expressing the fusion protein is demonstrated to be sufficient for the efficientpreparation of galactosylated oligosaccharides from inexpensive UDP-glucose in a multigram scale. Lysates containing the fusion protein are
Synthesis of Le<sup>X</sup> and Le<sup>Y</sup> Oligosaccharides with Azido-Type Spacer-Arms. Comparison of 3- and 4-Methoxybenzyl Groups as Key Temporary Protective Groups
5-Azido-3-oxa-1-pentanol was prepared from 2-(2-chloroethoxy)ethanol and used as a spacer in the chemical synthesis of the trisaccharide beta-D-Gal-(1-->4)-[alpha-L-Fuc-(1-->3)]-GlcNAc and the tetrasaccharide alpha-L-Fuc-alpha-(1-->2)-beta-D-Gal-(1-->4)-[alpha-L-Fuc-(1-->3)]-GlcNAc that represent the epitopes defining the human blood groups Le(x) and Le(y). The classical 4-methoxybenzyl group and the remarably acid-stable 3-methoxybenzyl group were compared as temporary protective groups for position 3 at the glucosamine unit to circumvent the problems associated with the simultaneous presence of allyl and azido groups. The resulting oligosaccharides were coupled to proteins with high efficiency.