Efficient synthesis of MUC4 sialylglycopeptide through the new sialylation using 5-acetamido-neuraminamide donors.
Sialylation reactions using a new sialyl donor, diethyl 5-acetamido-4,7,8,9-tetra-O-acetyl-3,5-dideoxy-2-O-beta-D-glycero-D-galacto-2-nonulopyranosylonamide phosphite (Neu5Ac-1-amide-2-phosphite) derivatives, and the synthesis of the sialyl-T N-MUC4 glycopeptide are described. The sialylation was performed in CH2Cl2 solvent toward the 6-hydroxyl group of several monosugar acceptors and generated alpha-sialoside in good yield under low temperature and TMSOTf activation system. Amide derivatives of sialoside were easily converted into naturally occurring sialoside after hydrolysis of the amide group. Sialyl-alpha(2,6)-GalN3 was also prepared by this new sialylation protocol, and then this sialoside was further converted into a Fmoc-protected sialyl-TN serine derivative for solid-phase glycopeptides synthesis. The solid-phase glycopeptide synthesis using this sialyl-TN serine derivative in which the sugar hydroxyl group was free afforded the target sialyl-TN-MUC4 glycopeptide.
Okamoto
Ryo
R
International Graduate School of Arts and Sciences, Yokohama City University, 22-2, Seto, Kanazawa-ku, Yokohama, 236-0027, Japan.
Souma
Shingo
S
Kajihara
Yasuhiro
Y
D000577:Amides / Q000737:chemistry*; D000586:Amination; D004952:Esters / Q000737:chemistry; D008745:Methylation; D015394:Molecular Structure; D055264:Mucin-4; D009077:Mucins / Q000138:chemical synthesis* / Q000737:chemistry; D013696:Temperature
D000577:Amides; D004952:Esters; D055264:Mucin-4; D009077:Mucins