Published on Web 10/03/2007
Anomeric Reactivity-Based One-Pot Synthesis of Heparin-Like
Oligosaccharides
Tu¨lay Polat and Chi-Huey Wong*
Contribution from the Department of Chemistry, The Scripps Research Institute,
La Jolla, California 92037
Received May 10, 2007; E-mail: wong@scripps.edu
Abstract: A highly efficient one-pot methodology is described for the synthesis of heparin and heparan
sulfate oligosaccharides utilizing thioglycosides with well-defined reactivity as building blocks. L-Idopyranosyl
and D-glucopyranosyl thioglycosides 5 and 10 were used as donors due to low reactivity of uronic acids as
the glycosyl donors in the one-pot synthesis. The formation of uronic acids by a selective oxidation at C-6
was performed after assembly of the oligosaccharides. The efficiency of this programmable strategy with
the flexibility for sulfate incorporation was demonstrated in the representative synthesis of disaccharides
17, 18, tetrasaccharide 23, and pentasaccharide 26.
Introduction
subunits, differing in their sulfation pattern and in the presence
of either D-glucuronic or L-iduronic acid.
Glycosaminoglycans (GAGs) are a family of highly sulfated,
linear polyanionic molecules that are found on most animal cell
surfaces as well as in the basement membranes and other
extracellular matrixes. Heparin and heparan sulfate are the most
widely studied members of this family. Heparin is exclusively
synthesized by tissue mast cells and is stored in cytoplasmic
granules, whereas the closely related molecule heparan sulfate
is expressed on cell surfaces and throughout tissue matrices.1
They are composed of repeating disaccharide units of 1 f 4
linked uronic acid and D-glucosamine (Figure 1). The uronic
acid residues typically consist of 90% L-iduronic acid and 10%
of D-glucuronic acid. The interaction of these polyanionic
molecules with proteins plays an important role in several
biological recognition processes, including blood coagulation,
virus infection, cell growth, inflammation, wound healing, tumor
metastasis, lipid metabolism, and diseases of the nervous
system.1,2
To date, more than one hundred heparin-binding proteins have
been identified. With the exception of the antithrombin III-
heparin interaction,3 in which the minimal sequence of heparin
pentasaccharide is required for binding, the structure and
function of heparin interaction with proteins is poorly under-
stood. This is mainly due to the complexity and heterogeneity
of these polymers. With the discovery of increasing numbers
of heparin-binding proteins, there is a need to characterize the
molecular elements responsible for binding to a particular protein
and modulating its biological activity. Since the first total
synthesis of heparin pentasaccharide,4 numerous synthetic
methodologies have been reported for the synthesis of heparin
fragments.5 Most of the strategies involve traditional stepwise
oligosaccharide synthesis in which protecting group and ano-
meric leaving group manipulations, intermediate workup, and
(3) (a) Koshida, S.; Suda, Y.; Sobel, M.; Ormsby, J.; Kusumoto, S. Bioorg.
Med. Chem. Lett. 1999, 9, 3127. (b) Petitou, M.; Duchaussoy, P.; Driguez,
P.-A.; Jaurand, G.; Herault, J.-P.; Lormeau, J.-C.; van Boeckel, C. A. A.;
Herbert, J.-M. Angew. Chem., Int. Ed. 1998, 37, 3009; (c) Petitou, M.;
Herault, J-P.; Bernat, A.; Driguez, P.-A.; Duchaussoy, P.; Lormeau, J.-C.;
Herbert, J.-M. Nature 1999, 398, 417.
The biosynthesis of heparin and heparan sulfate occurs by
similar pathways.2 Chain initiations occur in the Golgi apparatus.
The first step in the pathway involves the attachment of a
tetrasaccharide fragment to a serine residue in the core protein.
This structure is then modified by a series of enzymatic
transformations involving N-deacetylation followed by N-
sulfation, substrate directed epimerization of glucuronic acid
to iduronic acid moieties, and finally O-sulfation. Although these
enzymatic modifications result in a mixture of very complex
polysaccharides, structural studies have shown that heparin/
heparan sulfates are composed of only 19 distinct disaccharide
(4) (a) Jacquinet, J.-C.; Petitou, M.; Duchaussoy, P.; Lederman, I.; Choay, J.;
Torri, G.; Sinay, P. Carbohydr. Res. 1984, 130, 221. (b) Sinay, P.; Jacquinet,
J.-C.; Petitou, M.; Duchaussoy, P.; Lederman, I.; Choay, J.; Torri, G.
Carbohydr. Res. 1984, 132, C5. (c) Van Boeckel, C. A. A.; Beetz, T.;
Vos, J. N.; De Jong, A. J. M.; Van Aelst, S. F.; Van den Bosch, R. H.;
Mertens, J. M. R.; Van der Vlugt, F. A. Carbohydr. Res. 1985, 4, 293. (c)
Ichikawa, Y.; Monden, R.; Kuzuhara, H. Carbohydr. Res. 1988, 172, 37.
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therein. (b) Noti, C.; Seeberger, P. H. Chem. Biol. 2005, 12, 731, and
references therein. (c) Orgueira, H. A.; Bartolozzi, A.; Schell, P.; Litiens,
R. E. J. N.; Palmacci, E. R.; Seeberger, P. H. Chem.-Eur. J. 2003, 9, 140.
(d) Haller, M. F.; Boons, G.-J. Eur. J. Org. Chem. 2002, 67. 2033. (e) de
Paz, J.-L.; Ojeda, R.; Erichardt, N.; Martin-Lomas, M. Eur. J. Org. Chem.
2003, 68, 3308. (f) Yu, H. Y.; Furukawa, J.-I.; Ikeda, T.; Wong, C.-H.
Org. Lett. 2004, 6, 723. (g) Lee, J.-C.; Lu, X.-A.; Kulkarni, S. S.; Wen,
Y.-S.; Hung, S.-C. J. Am. Chem. Soc. 2004, 126, 476. (h) Codee, J. D. C.;
Stubba, B.; Schiattarella, M.; Overkleeft, H. S.; van Boeckel, C. A. A.;
van Boom, J. H.; van der Marel, G. A. J. Am. Chem. Soc. 2005, 127, 3767.
(i) Zhou, Y.; Lin, F.; Chen, J.; Yu, B. Carbohydr. Res. 2006, 341, 1619.
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C. Org. Lett. 2006, 8, 5995.
(1) (a) Comper, W. D. Heparin and Related Polysaccharides, Vol. 1; Gordon
and Breach: New York, 1981. (b) Linhardt, R. J.; Toida, T. In Carbohy-
drates as Drugs; Witczak, Z., Nieforth, K., Eds.; Dekker: New York, 1998;
pp 277-341.
(2) (a) Kjellen, L.; Lindahl, U. Annu. ReV. Biochem. 1991, 60, 443. (b) Conrad,
H. E. Heparin Binding Proteins; Academic Press: New York, 1998. (c)
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10.1021/ja073098r CCC: $37.00 © 2007 American Chemical Society
J. AM. CHEM. SOC. 2007, 129, 12795-12800
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