Synthesis of core-class 2 O-linked glycopeptides: a benzyl-protected tetrasaccharyl serine and its derivative carrying a hydrophobic cholestanyl group.
A core-class 2 tetrasaccharide-linked serine was synthesized in a convergent manner. The coupling reaction of disaccharide glycosyl donor 3 and acceptor 4 stereoselectively afforded tetrasaccharide 15, which was converted to glycosyl fluoride 20. Glycosylation of Fmoc serine allyl ester 5 with 20 produced alpha- and beta-glycosides in 40% and 33% yields, respectively. Alpha-Isomer 21 was converted into 1, a useful building block for the solid-phase synthesis of glycopeptides. On the other hand, 21 was N-deprotected and condensed with hydrophobic cholestanol through a succinyl spacer. The same compound was alternatively synthesized by coupling 20 and 28. Functional group manipulation and hydrogenation afforded core 2 tetrasaccharide-cholestanol conjugate 2.
Watabe
Jun
J
Institute of Glycotechnology, Department of Applied Biochemistry, Tokai University, Hiratsuka-shi, Kanagawa, Japan.
Singh
Latika
L
Nakahara
Yuko
Y
Ito
Yukishige
Y
Hojo
Hironobu
H
Nakahara
Yoshiaki
Y
D006020:Glycopeptides / Q000138:chemical synthesis* / Q000737:chemistry*; D057927:Hydrophobic and Hydrophilic Interactions; D015394:Molecular Structure; D012694:Serine / Q000737:chemistry*
D006020:Glycopeptides; D012694:Serine