Synthetic mucin fragments. Benzyl O-beta-D-galactopyranosyl-(1----3)-O-(2-acetamido-2-deoxy-beta-D- glucopyranosyl)-(1----6)-2-acetamido-2-deoxy-alpha-D-galactopyranoside and O-alpha-L-fucopyranosyl-(1----3)-O-(2-acetamido-2-deoxy-beta-D- glucopyranosyl)-(1----6)-2-acetamido-2-deoxy-D-galactopyranose.
Benzyl 2-acetamido-6-O-(2-acetamido-2-deoxy-4,6-O-isopropylidene-beta-D- glucopyranosyl)-2-deoxy-3,4-O-isopropylidene-alpha-D-galactopyranoside (2) was obtained by acetalation of its parent disaccharide with 2,2-dimethoxypropane in hot N,N-dimethylformamide and in the presence of 4-toluenesulfonic acid. Glycosylation of 2 with 2,3,4,6-tetra-O-acetyl-alpha-D-galactopyranosyl bromide (catalyzed by mercuric cyanide), followed by removal of the protecting groups afforded the title trisaccharide 7. A second product was also isolated, which was identified as a derivative of 7 having a 2-cyanopropyl group. Glycosylation of diacetal 2 with 2,3,4-tri-O-benzyl-alpha-L-fucopyranosyl bromide (under catalysis by bromide ion), followed by systematic removal of the protecting groups furnished the title trisaccharide 13. The structures of both 7 and 13 were established by 13C-n.m.r. spectroscopy.
Thomas
R L
RL
Department of Gynecologic Oncology, Roswell Park Memorial Institute, Buffalo, New York 14263.
Rutan
J F
JF
Abbas
S A
SA
Matta
K L
KL
D009682:Magnetic Resonance Spectroscopy; D009077:Mucins / Q000032:analysis*; D009844:Oligosaccharides / Q000032:analysis / Q000138:chemical synthesis; D014312:Trisaccharides / Q000032:analysis / Q000138:chemical synthesis*
D009077:Mucins; D009844:Oligosaccharides; D014312:Trisaccharides; C061113:benzyl O-galactopyranosyl-(1-3)-O-(2-acetamido-2-deoxyglucopyranosyl)-(1-6)-2-acetamido-2-deoxygalactopyranoside; C061115:O-fucopyranosyl-(1-3)-O-(2-acetamido-2-deoxyglucopyranosyl)-(1-6)-2-acetamido-2-deoxygalactopyranoside