Convenient synthesis of a sialylglycopeptide-thioester having an intact and homogeneous complex-type disialyl-oligosaccharide.
Carbohydr Res
; 341(10): 1333-40, 2006 Jul 24.
Article
en En
| MEDLINE
| ID: mdl-16701588
ABSTRACT
Access to glycopeptides with C-terminal thioester functionality is essential for the synthesis of large glycopeptides and glycoproteins through the use of native chemical ligation. Toward that end, we have developed a concise method for the synthesis of a glycopeptide thioester having an intact complex-type dibranched disialyl-oligosaccharide. The synthesis employed a coupling reaction between benzylthiol and a free carboxylic acid at the C-terminus of a glycopeptide in which the peptide side chains are protected. After construction of glycopeptide on the HMPB-PEGA resin through the Fmoc-strategy, the protected glycopeptide was released upon treatment with acetic acid/trifluoroethanol and then the C-terminal carboxylic acid was coupled with benzylthiol at -20 degrees C in DMF. For this coupling, PyBOP/DIPEA was found to be the best for the formation of the thioester, while avoiding racemization. Finally, the protecting groups were removed in good yield with 95% TFA, thus affording a glycopeptide-thioester having an intact and homogeneous complex-type disialyl-oligosaccharide.
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Oligosacáridos
/
Ácidos Siálicos
/
Glicopéptidos
Idioma:
En
Revista:
Carbohydr Res
Año:
2006
Tipo del documento:
Article
País de afiliación:
Japón