Mendeleev Commun., 2009, 19, 62–63
NHBoc
NHBoc
O
NHBoc
NHBoc
viii
O
O
O
BocHN
BocHN
HO
FmocHN
FmocHN
N
5
5
5
H
NH2
NHBoc
[
ix, x]n
v, vi, vii
NHBoc
O
NHGly Boc
n
NHBoc
N
H
NHGlynBoc
OH
NHGlynBoc
xi, xii
O
i, ii, iii, iv
OH
NHGly Boc
n
OH
OH
6'SLN–spacer–HN
N
NHGlynBoc
NHGlynBoc
H
Scheme 1 Reagents and conditions: i, HBr/AcOH, boiling, 18 h, then HBr/H SO , boiling, 8 h, 80%; ii, NaN , DMSO, 90 °C; iii, H , Pd/C, EtOH, 90%;
2
4
3
2
iv, Boc O, EtOH, 75%; v, MsCl/Et N, CH Cl , 0 °C, 99%; vi, NaN , DMSO, 110 °C, 30%; vii, PPh , MeOH/H O, 85%; viii, FmocNH(CH CH O) CH COOSu,
2
3
2
2
3
3
2
2
2
5
2
DMF, 50%; ix, CF COOH; x, BocGly OSu–Et N or BocGlyOSu–Et N, DMF, 67–98%; xi, piperidine, DMSO; xii, 6'SLN–spacer–COONp, DMSO, 60 °C,
3
2
3
3
45–70%.
were protected and the hydroxyl group was stepwise transformed
into amino group, which was acylated by N-hydroxysuccinimide
Z/nm
4
2
6000
5000
A
B
14
ester of Fmoc-protected aminoacid FmocNH(CH CH O) CH -
B
2
2
5
2
COOSu. Oligoglycine antennae were elongated by stepwise
N-acylation using N-hydroxysuccinimide esters of Boc-pro-
tected glycine or diglycine. After each step Boc groups were
removed by treatment with trifluoroacetic acid and the obtained
amine was elongated further. Thus, a set of branched peptides,
A
0
1000
2000
4
3
2
1
000
000
000
000
7
Cross-section A–A/Å
4
2
0
FmocNH(CH CH O) CH CONHCH C(CH NHGly Boc) , where
0
2000 4000 6000
2
2
5
2
2
2
n
3
0
400
800
1200
n = 2, 4, 6–8, was synthesized. After attachment of all glycine
residues Fmoc group was removed from oligoethylene glycol
spacer by treatment with piperidine (for peptides with n = 6–8),
and glycopeptide was obtained by N-acylation using 6'SLN-
O(CH ) NHCO(CH ) COONp, where 6'SLN is trisaccharide
X/Å
Cross-section B–B/Å
Figure 2 AFM image of the aggregates of triantennary glycopeptide (n = 7);
solution of the glycopeptide (1 mg cm ) was placed on mica surface, kept
for 1 min and then unadsorbed material was removed by a nitrogen stream.
–3
2
3
2 4
Neu5Acα2-6Galβ1-4GlcNAcβ-.
3.5 nm and planar sizes of 20–500 nm (Figure 2), which can
be considered as two-dimensional crystals similar to the tetra-
antennary tectomers.
According to size-exclusion chromatography data, the glyco-
peptides assemble in aqueous solution, when the length of oligo-
glycine antennae reaches seven (Ultropac Column TSK G4000SW
The antiviral activity of glycopeptides was studied in fetuin
binding inhibition test, where the synthesized glycopeptides
inhibited the binding of fetuin peroxidase conjugate to virus
–1
7
.5×300 mm, Sweden; elution with 2 M NaCl, 1 ml min ; UV
detection at l = 195 nm; retention times for monomers 8.1–8.6 min,
for aggregates 3.7–3.9 min). The ratio of monomeric to aggregated
forms depends on length of the peptide antennae and the nature
of the end groups. Glycopeptides with terminal Boc groups
4
immobilized on a plastic. All the assembling glycopeptides
show antiviral activity one order of magnitude higher than
the activity of monomeric 6'SLN, while their non-assembling
analogues are not active.
assemble in water solution; those with terminal NH groups do
2
not assemble presumably because of intramolecular interaction
between the amino groups and negatively charged sugar.
The Raman spectroscopy of the solid Boc-substituted peptide
with n = 7 demonstrates that antennae adopt polyglycine II
conformation (characteristic lines at 884, 1261, 1381, 1424 and
Thus, for triantennary glycopeptides we do not observe such
dramatically increased virus-blocking activity (three orders of
magnitude) as in case of tetraantennary ones.
This work was supported by the RAS Presidium programme
‘Molecular and Cell Biology’.
–
1
1
651 cm ). The supramolecular organization of glycopeptides
was investigated by atomic force microscopy. AFM studies
show that the aggregates are thin, flat plates with height about
References
1
2
M. N. Matrosovich and H.-D. Klenk, Rev. Med. Virol., 2003, 13, 85.
N. V. Bovin, A. B. Tuzikov, A. A. Chinarev and A. S. Gambaryan,
Glycoconjugate J., 2004, 21, 471.
A. B. Tuzikov, A. A. Chinarev, A. S. Gambaryan, V. A. Oleinikov, D. V.
Klinov, N. B. Matsko, V. A. Kadykov, M. A. Ermishov, I. V. Demin,
V. V. Demin, P. D. Rye and N. V. Bovin, ChemBioChem, 2003, 4, 147.
A. S. Gambaryan and M. N. Matrosovich, J. Virol. Methods, 1992, 39, 11.
Table 1 Antiviral activity of triantennary glycopeptides related to 6'SLN.
Virus
3
4
Glycopeptide
NIB/23/89M
H1N1)
NIB/26/90M
(H3N2)
B/NIB/48/90M
(B)
(
R = Boc, n = 6
R = Boc, n = 7
R = H, n = 7
15
30
1
7.5
7.5
1
4
£ 1
7.5
£ 1
4
1 (200)
R = Boc, n = 8
10
6'SLN
1 (150)a
1 (150)a
a
a
Values of IC , mkM, for monomeric 6'SLN are given in parentheses.
5
0
Received: 2nd September 2008; Com. 08/3208
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