Synthesis 2009(13): 2210-2222  
DOI: 10.1055/s-0029-1216820
PAPER
© Georg Thieme Verlag Stuttgart ˙ New York

Stability of 5(6)-Carboxyfluorescein in Microwave-Assisted Synthesis of Fluorescein-Labelled O-Dimannosylated Peptides

Renata Kowalczyka,c, Paul W. R. Harrisa,c, Rod P. Dunbarb,c, Margaret A. Brimble*a,c
a Department of Chemistry, University of Auckland, 23 Symonds St, Auckland 1142, New Zealand
b School of Biological Sciences, University of Auckland, Private Bag 92019, Auckland 1142, New Zealand
c Maurice Wilkins Centre for Molecular Biodiscovery, University of Auckland, Private Bag 92019, Auckland 1142, New Zealand
Fax: +64(9)3737422; e-Mail: m.brimble@auckland.ac.nz;
Further Information

Publication History

Received 11 February 2009
Publication Date:
14 May 2009 (online)

Abstract

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.