Methodology for the efficient, automated and microwave-assisted
Fmoc solid-phase synthesis of a 5(6)-carboxyfluorescein-labelled
Lys(Dde)-Gly-Wang resin that can be further elongated through the
lysine N
ε amino group
is described. Incorporation of O-dimannosylated peptides onto this
resin using Fmoc-[α-d-Man(OBz)4-(1→6)-α-d-Man(OBz)3α1-]Ser-OH
and PEG-[α-d-Man(OBz)4-(1→6)-α-d-Man(OBz)3α1-]-OH
building blocks is demonstrated. Conditions were optimised to enable
the efficient automated synthesis of several carboxyfluorescein-labelled
dimannosylated peptides. 5(6)-Carboxyfluorescein was shown to be
stable to the microwave conditions used for glycopeptide synthesis.
The methodology described provides a robust, flexible synthetic
platform for the preparation of a variety of fluorescently labelled
glycopeptides (especially O-dimannosylated peptides) for biological evaluation.
carbohydrates - glycopeptides - mannosylated
amino acids - glycosylations - solid-phase synthesis