Convergent synthesis of neoglycopeptides by coupling of 2-bromoethyl glycosides to cysteine and homocysteine residues in T cell stimulating peptides.
The 2-bromoethyl beta-glycosides of the disaccharide galabiose [Gal(alpha1-4)Gal] and the trisaccharides globotriose [Gal(alpha1-4)Gal(beta1-4)Glc] and 3'-sialyllactose [Neu5Ac(alpha2-3)Gal(beta1-4)Glc] have been prepared by improved routes. The 2-bromoethyl glycosides were then used in cesium carbonate promoted alkylations of the sulfhydryl groups of cysteine and homocysteine residues in T cell stimulating peptides. This convergent and general approach was used to prepare 16 neoglycopeptides which were obtained in 52-95% yields after purification by HPLC. 1H NMR spectroscopy revealed that beta-elimination and epimerization of neoglycopeptide stereocentres did not occur during the synthesis.
Bengtsson
M
M
Astra Draco AB, Preclinical R&D, Lund, Sweden.
Broddefalk
J
J
Dahmén
J
J
Henriksson
K
K
Kihlberg
J
J
Lönn
H
H
Srinivasa
B R
BR
Stenvall
K
K
D000595:Amino Acid Sequence; D000818:Animals; D002240:Carbohydrate Sequence; D002851:Chromatography, High Pressure Liquid; D003545:Cysteine / Q000737:chemistry; D006020:Glycopeptides / Q000138:chemical synthesis* / Q000737:chemistry / Q000276:immunology; D006027:Glycosides / Q000737:chemistry; D006710:Homocysteine / Q000737:chemistry; D006801:Humans; D016056:Immunodominant Epitopes / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D008969:Molecular Sequence Data; D013601:T-Lymphocytes / Q000276:immunology
D006020:Glycopeptides; D006027:Glycosides; D016056:Immunodominant Epitopes; D006710:Homocysteine; D003545:Cysteine