Chemistry Reference
In-Depth Information
Man
AcO
OAc
O
CH
2
Man
O
AcO
AcO
CH
2
O
O
O
CH
2
O
7
N
3
O
178
O
N
N
RO
N
N
3
(i) CuSO
4
/ Na ascorbate
MW, 70°C, 30 min
RO
N
RO
O
O
O
N
S
N
RO
NHFmoc
HO
HO
(ii) NH
3
,MeOH,rt,24h
RO
HO
n
O
O
S
HO
NH
2
177
n
OH
n = 0, 1, 2
R = Ac
179
n=6
R=Bz
n=0,1,2,6
SCHEME 5.41
Synthesis of multimannosides on amino-functionalized oligosaccharide
scaffolds.
and only a few examples have been reported [19b-c, 66]. When designing glycoclus-
ters to study biological processes, specificity, affinity, and stability against glycolytic
enzymes are important factors to be considered. In contrast to natural
O
-linked
sugars, the
S
-carbohydrate mimetics are usually resistant to metabolic processes
and are seen as potential precursors of promising carbohydrate-based therapeutics.
Particularly, the resistance of glycoclusters to enzyme hydrolysis is crucial to
circumvent degradation when they are internalized in the cell. The replacement of
HO
N
3
O
O
HO
Man
N
3
HO
CH
2
O
HO
O
OH
O
O
7
N
3
O
HO
+
+
O
181
HO
S
SCN
O
NH
2
HO
O
OH
FITC
180
CuSO
4
/Na ascorbate
DMF/H
2
O
Man
O
Man
CH
2
O
Man
O
CH
2
O
O
HO
CH
2
O
N
OH
N
N
O
O
N
HO
O
N
HO
N
N
HO
S
O
O
N
O
N
H
HO
HO
NH
O
S
O
HO
182
OH
SCHEME 5.42
Synthesis of a fluorescent glycocluster probe.
Search WWH ::
Custom Search