Synthesis of the C1-phosphonate analog of UDP-GlcNAc

Article abstract of DOI:10.1016/j.carres.2006.05.008

We describe the first synthesis of the C1-phosphonate analog of UDP-GlcNAc, based on a new preparation of the corresponding glycosyl phosphonate. This C-glycosyl analog is shown to be a very weak inhibitor (K_i > 10 mM) of fungal chitin synthase

Full text of DOI:10.1016/j.carres.2006.05.008

Carbohydrate Research 341 (2006) 1998–2004
Synthesis of the C1-phosphonate analog of UDP-GlcNAc
Robert Chang, Thanh-Trang Vo and Nathaniel S. Finney*
Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, CA 92093-0358, USA
Received 9 March 2006; received in revised form 9 May 2006; accepted 10 May 2006
Available online 5 June 2006
Abstract—We describe the first synthesis of the C1-phosphonate analog of UDP-GlcNAc, based on a new preparation of the cor-
responding glycosyl phosphonate. This C-glycosyl analog is shown to be a very weak inhibitor (Ki > 10 mM) of fungal chitin syn-
thase, indicating that at least in this case the replacement of the anomeric oxygen with a methylene group is not an innocent
substitution.
ꢀ 2006 Elsevier Ltd. All rights reserved.
Keywords: UDP-GlcNAc; Glycosyl phosphonate; Chitin synthase; Glycosyl transferase inhibition
1. Introduction
(poly-b-(1!4)-GlcNAc), an essential component of the
fungal cell wall (Fig. 2).3 CS is absent in humans, and
it is thus an attractive therapeutic target. In spite of this,
relatively little progress has been made in developing CS
inhibitors.4
In the course of our efforts to develop new CS inhib-
itors,5 we became interested in obtaining 2, the phospho-
nate analog of UDP-GlcNAc. C-Glycosyl phosphonate
derivatives are well established as inert isosteres of the
Nucleotide diphosphate (NDP) sugars and glycosyl
phosphates play a central role in glycobiology.1 Accord-
ingly, significant effort has been devoted to the develop-
ment of NDP sugar mimics, such as C-glycosyl analogs,
as inhibitors of the associated enzymes.2 The ubiquitous
NDP UDP-GlcNAc (1; Fig. 1) is polymerized by the
fungal enzyme chitin synthase (CS) to form chitin
Figure 1. UDP-GlcNAc and related phosphonates.
*
Corresponding author at present address: Organic Chemistry Institute, University of Zurich, Winterthurerstrasse 190, CH-8057 Zurich,
Switzerland. E-mail: finney@oci.unizh.ch
0008-6215/$ - see front matter ꢀ 2006 Elsevier Ltd. All rights reserved.
doi:10.1016/j.carres.2006.05.008

R. Chang et al. / Carbohydrate Research 341 (2006) 1998–2004
1999
Figure 2. Biosynthesis of chitin from UDP-GlcNAc.
corresponding phosphates.2 While there is only a single
report of the synthesis and evaluation of the UDP-
glucose analog (3) (arguably the simplest phosphonate
isostere),6 several syntheses of phosphonate analogs of
a-D-glucose-1-phosphate have been reported, and the
C-glycosyl analog of a-D-glucose (5) has been studied
as a substrate-analog inhibitor of several enzymes.7 In
contrast, there are no biological studies of either 2 or
the corresponding a-D-GlcNAc-1-phosphate analog 4.
This can be attributed to limited synthetic availability:
to our knowledge, 2 has never been prepared, and only
a single synthesis of phosphonate 4 has been achieved,
although related C-glycosyl compounds have been syn-
thesized.8 The first synthesis of 2 is reported here, based
on a new synthesis of a precursor to 4 and 5.
2. Results and discussion
2.1. Overview of the synthesis of C-glycosyl derivatives
2 and 4
In the retrosynthetic direction, 2 was envisioned to arise
from coupling of an activated uridine 50-monophos-
phate (UMP) equivalent with 4 (Scheme 1). The previ-
ous reported synthesis of 4 began with 2,3,5-tri-O-
benzyl-arabinofuranose and provided 4, via intermedi-
ate iodide 10, in 12 steps with a reported overall yield
of 14% (Fig. 3).8f A report of the apparently problematic
behavior of the organomercury intermediates,7b coupled
with the emergence of direct methods for vinylation of
glucal epoxides,9 prompted us to prepare 10 from the
Scheme 1. Retrosynthetic overview.
Figure 3. The previous synthesis of 4.

2000
R. Chang et al. / Carbohydrate Research 341 (2006) 1998–2004
corresponding alcohol, available in one step from the
a-vinyl glycosyl compound 6, which could in turn be
prepared in two steps from the commercially available
1,5-anhydro-2-deoxy-3,4,6-tri-O-benzyl-D-arabino-hex-
1-enitol (tri-O-benzyl-D-glucal).
steps and 80% yield from 2,3,5-tri-O-benzyl-b-D-arabino-
furanose. However, the new synthesis described here is
operationally simple and avoids toxic and potentially
problematic organomercury intermediates.
2.3. Synthesis of C-glycosyl derivative 4
2.2. Synthesis of iodide 10
C-Glycosyl compound 4 was prepared from 10 by the
known route (Scheme 3).8i Iodide 10 is also an estab-
lished precursor to 5.
Our synthesis of 10 began with tri-O-benzyl-D-glucal
(Scheme 2). Epoxidation with 3,3-dimethyldioxirane
(DMDO),10 followed by aluminum-mediated vinylation
provided 6 in 75% yield over two steps.9 TBS protection
of the C-2 hydroxyl group was successfully achieved with
TBSOTf (TBSCl proving ineffective), affording silyl ether
7 in high yield. Subsequent ozonolysis and in situ reduc-
tion with NaBH4 furnished the alcohol 8. While direct
iodination of 9 with iodine and triphenylphosphine was
unsuccessful, 8 could be quantitatively converted to the
corresponding mesylate 9 and treated with tetrabutyl-
ammonium iodide (TBAI) in DMF at 120 ꢁC, providing
the desired iodide 10 in six operations and 28% overall
yield from tri-O-benzyl-D-glucal.11 In comparison, the
previous report of 10 describes its preparation in three
2.4. Synthesis of the nucleoside phosphonate 2
The synthesis of 2 was effected via the Moffatt–Wong
protocol (Scheme 4),11 by which treatment of 4 with uri-
dine 50-monophosphomorpholidate in the presence of
1-H-tetrazole provided 2 in 37% yield after purification.
2.5. Biological evaluation of 2
We have conducted chitin synthase inhibition assays
with 2 (see Section 4 for details). Our standard chitin
synthase assay is conducted using freshly isolated
Scheme 2. Synthesis of intermediate iodide 10.
Scheme 3. Preparation of C-glycosyl derivative 4.

R. Chang et al. / Carbohydrate Research 341 (2006) 1998–2004
2001
Scheme 4. Conversion of 4 to 2.
tide portion of the substrate. This is not in itself surpris-
ing, given that GlcNAc has no inhibitory effect on chitin
synthase activity. However, it also indicates that binding
affinity is not simply a matter of having a negatively
charged nucleoside diphosphate present, since replace-
ment of the anomeric oxygen does not alter the formal
charge of the C-glycosyl compound 2.
3. Conclusion
We have reported the first synthesis of 2, as well as a
mercury-free synthesis of 4. This is significant in its
own right, as GlcNAc transferases are ubiquitous and
both 2 and 4 should prove to be valuable tools for study-
ing these enzymes. However, as a cautionary note, we
have shown that 2 is, at best, a very weak inhibitor
(Ki > 10 mM) of chitin synthase. This indicates that, at
least for this enzyme, the replacement of the anomeric
phosphonate oxygen with a methylene group—a wide-
spread strategy in the synthesis of sugar phosphate and
NDP sugar analogs—is not an innocent substitution.
Figure 4. Inhibition of CS by 2.
chitin synthase from Saccharomyces cerevisiae, in pH 7.6
buffer, using a combination of UDP-GlcNAc and
3H-UDP-GlcNAc (ca. 5 · 10ꢀ8 mol/assay vial, com-
bined).5,12 At a fixed time (typically 1 h), the reaction
is terminated and the chitin is precipitated by addition
of trichloroacetic acid and ethanol. The precipitated chi-
tin is isolated by filtration, and chitin formation is quan-
tified by scintillation counting of the filter pad. Carrying
out the standard radioactivity-based assay for CS activ-
ity in the absence and presence of 2 (4 mM) and several
concentrations (1–25 mM)ꢀ of UDP-GlcNAc revealed
that 2 is best a weak inhibitor of CS (Ki > 10 mM;
Fig. 4). While the inhibition curve is qualitatively consis-
tent with competitive inhibition, this could not be defin-
itively demonstrated—full activity was not recovered at
25 mM UDP-GlcNAc, and at higher substrate concen-
trations the assay becomes unreliable.
4. Experimental
4.1. General
All reactions were carried out in oven or flame dried
glassware, under an atmosphere of N2, unless otherwise
noted. THF and CH2Cl2 were dried by passage through
an activated column of alumina, and pyridine was
distilled from CaH2. All other reagents were used as
received unless otherwise stated. Thin layer chromato-
It is instructive to compare the observed Ki (>10 mM)
with the KM for UDP-GlcNAc (ꢁ1 mM) and the Ki for
UDP itself (ꢁ1 mM).3 Treating KM as a qualitative mea-
sure of substrate binding, this comparison indicates that
the majority of binding affinity derives from the nucleo-
graphy was performed on Silica Gel 60 plates (F254
,
EM Science) and visualized with UV light or stained
with KMnO4, ninhydrin, or phosphomolybdic acid.
Flash column chromatography was performed using
silica gel (Selecto Scientific, 32–63 lm) or reverse phase
silica gel (EM Science, Silica Gel 60, RP-18) as indi-
cated. IR spectra were recorded using a Nicolet 550
spectrometer. 1H NMR data were acquired on a Varian
HG-400 (400 MHz) spectrometer and are reported in
ppm relative to residual monoprotium solvent (CHCl3
at 7.26 ppm, CHD2OD at 3.30 ppm, HOD at
ꢀ In order to conserve material (i.e., 2), we opted to carry out inhibition
studies at fixed inhibitor concentration and variable substrate
concentration. While this is not the conventional method, we have
previously shown it to be adequate for Ki determination (Ref. 5). In
principle, this approach also allows demonstration of competitive
inhibition—even at fixed inhibitor concentration, addition of excess
substrate should eventually lead to recovery of full activity if the
inhibitor is competitive.

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R. Chang et al. / Carbohydrate Research 341 (2006) 1998–2004
4.67 ppm). Proton decoupled 13C NMR spectra were
obtained on a Varian HG-400 (100 MHz) spectrometer
and are reported in ppm relative to solvent as internal
standard (CDCl3 at 77.0 ppm, CD3OD at 49.0 ppm,
added CH3OH at 49.5 ppm for D2O). High resolution
mass spectra were obtained on an Ionspec Ultima
FTMS (MALDI-FTMS) at the Scripps Research Insti-
tute, La Jolla, CA. 1-Deoxy-1-a-ethenyl-3,4,6-tri-O-benz-
yl-D-glucose (6) was prepared by the method of Rainier
et al.9 Iodide 10 was converted to phosphonate 4 by
the method of Casero et al.8i The identity of known
intermediates was confirmed by comparison to reported
analytical data. The chitin synthase assay protocol used
is based on the procedure of Orlean,12 modified after
helpful discussions with the author.5 S. cerevisiae strains
(PP-1D, wild type) were kindly provided by Professor
Orlean and were stored at ꢀ70 ꢁC on freezer stabs.
(0.13 g, 0.22 mmol, 95%) as a pale yellow oil; 1H
NMR (400 MHz, CDCl3): d 7.38–7.24 (m, 13H), 7.10
(m, 2H), 6.16 (ddd, J 18.0, 11.2, 4.4 Hz, 1H), 5.44 (m,
2H), 4.93 (d, J 11.2 Hz, 1H), 4.79 (m, 2H), 4.70 (d, J
12.8 Hz, 1H), 4.50 (m, 4H), 3.96 (m, 1H), 3.83 (m,
1H), 3.66 (m, 3H), 0.98 (s, 9H), 0.06 (s, 6H); 13C
NMR (100 MHz, CDCl3): d 138.9, 138.2, 138.0, 131.9,
128.4, 128.3, 128.2, 128.0, 127.9, 127.6, 127.5, 127.4,
127.3, 119.2, 83.6, 78.4, 76.3, 75.4, 75.0, 73.5, 73.2,
71.9, 68.9, 25.8, 17.9, ꢀ4.6, ꢀ4.7; FTIR (thin film,
cmꢀ1): 2954, 2928, 2896, 2857, 1154, 1360, 1252, 1156,
1116, 1088, 1073, 1028, 1005, 865, 838; HR-MALDI-
FTMS: calcd for C35H46O5SiNa [MꢀNa+] 597.3007.
Found: m/z 597.3006. TLC (1:5 EtOAc–hexane), Rf:
0.54.
4.4. 1-Deoxy-1-a-hydroxymethyl-2-O-(tert-butyldimeth-
ylsilyl)-3,4,6-tri-O-benzyl-D-glucose (8)
4.2. C-Glycosyl analog of UDP-GlcNAc (2)
Ozone was bubbled through a soln of 7 (0.13 g,
0.23 mmol, 1 equiv) in CH2Cl2 (2 mL) at ꢀ78 ꢁC until
it appeared blue (15 min). N2 was subsequently bubbled
through the reaction mixture to remove excess ozone,
and the soln was warmed to 0 ꢁC. MeOH (2 mL) and
NaBH4 (0.02 g, 0.46 mmol, 2.0 equiv) were subsequently
added, and the reaction mixture was allowed to warm
slowly to rt. After 4 h, the reaction was concentrated
under diminished pressure, dissolved in CH2Cl2
(20 mL), washed with satd NH4Cl (1 · 20 mL), and
back-extracted with CH2Cl2 (1 · 20 mL). The extracts
were combined, dried over Na2SO4, and concentrated
under diminished pressure. Purification using silica gel
chromatography yielded 8 (0.07 g, 0.12 mmol, 54%) as
A soln of 4 (0.034 g, 0.11 mmol, 1 equiv) in dry pyridine
(0.5 mL) was added to a soln of 4-morpholine-N,N0-di-
cyclohexylcarboxamidinium uridine 50-monophospho-
morpholidate (0.023 g, 0.33 mmol, 3.0 equiv), and 1-H-
tetrazole (0.031 g, 0.44 mmol, 4.0 equiv) in dry pyridine
(0.5 mL) and stirred for 5 d at room temperature. The
soln was then concentrated under diminished pressure
and applied to size-exclusion gel (Bio-Rad, Bio-Gel, P-
2 Fine, 2.5 · 100 cm), eluted with 0.25 M NH4HCO3
and lyophilized to obtain 2 (0.026 g, 0.04 mmol, 37%)
1
as a fluffy white solid; H NMR (400 MHz, D2O): d
7.78 (d, J 8.0 Hz, 1H), 5.79 (m, 2H), 4.26–4.00 (m,
6H), 3.82 (m, 1H), 3.67 (m, 1H), 3.54 (m, 3H), 3.29 (t,
J 9.0 Hz, 1H), 2.16 (m, 2H), 1.86 (s, 3H); 13C NMR
(100 MHz, D2O): d 175.1, 166.9, 152.4, 142.3, 103.2,
89.1, 83.8, 74.4, 74.2, 73.4, 71.2, 70.2, 65.3, 61.3, 54.2,
49.5, 25.8 (JC–P 144.9 Hz), 22.6; HR-MALDI-FTMS:
calcd for C18H28N3O16P2 [MꢀHꢀ]: 604.0950. Found:
m/z 604.0949. TLC (33% 1 M aq NH4OAc–i-PrOH),
Rf: 0.55.
1
a colorless oil; H NMR (400 MHz, CDCl3): d 7.35–
7.24 (m, 13H), 7.06 (m, 2H), 4.87 (d, J 11.2 Hz, 1H),
4.81 (d, J 11.2 Hz, 1H), 4.76 (d, J 10.8 Hz, 1H), 4.62
(d, J 12.0 Hz, 1H), 4.52 (d, J 12.0 Hz, 1H), 4.45 (d,
J 10.8 Hz, 1H), 4.09 (m, 1H), 3.98 (m, 2H), 3.88 (dd,
J 12.4, 4.0 Hz, 1H), 3.72–3.57 (m, 5H), 0.82 (s, 9H),
0.12 (s, 3H), 0.05 (s, 3H); 13C NMR (100 MHz,
CDCl3): d 138.6, 137.9, 137.8, 128.4, 128.3, 128.2,
128.0, 127.9, 127.8, 127.7, 127.4, 127.3, 83.4, 78.0,
76.6, 75.4, 75.0, 73.6, 72.5, 72.0, 68.9, 58.1, 25.8, 17.9,
ꢀ4.6, ꢀ4.8; FTIR (thin film, cmꢀ1): 2952, 2928, 2885,
2857, 1454, 1360, 1254, 1124, 1094, 1071, 1028, 1005,
860, 837; HR-MALDI-FTMS: calcd for C34H47O6Si
[MꢀH+] 579.3136. Found: 579.3137; TLC (4:6
EtOAc–hexane), Rf: 0.47.
4.3. 1-Deoxy-1-a-ethenyl-2-O-(tert-butyldimethylsilyl)-
3,4,6-tri-O-benzyl-D-glucose (7)
TBSOTf (0.10 mL, 0.48 mmol, 2.0 equiv) was added to a
soln of 1-deoxy-1-a-ethenyl-3,4,6-tri-O-benzyl-D-glucose
(6, 0.11 g, 0.24 mmol, 1 equiv),9 2,6-lutidine (0.08 mL,
0.69 mmol, 2.9 equiv) and CH2Cl2 (2 mL) at 0 ꢁC under
argon. The reaction was allowed to warm to room tem-
perature and was stirred for 2 h. The soln was then
diluted with CH2Cl2 (20 mL), washed with 1 · 20 mL
satd aq NaHCO3, and back-extracted with CH2Cl2
(1 · 20 mL). The extracts were combined and washed
with brine (1 · 40 mL), dried over Na2SO4, and concen-
trated under diminished pressure. Purification by silica
gel chromatography (1:20 EtOAc–hexane) afforded 7
4.5. 1-Deoxy-1-a-iodomethyl-2-O-(tert-butyldimethyl-
silyl)-3,4,6-tri-O-benzyl-D-glucose (10)
Methanesulfonyl chloride (0.004 lL, 0.052 mmol, 1.2
equiv) was added to a soln of 8 (0.026 g, 0.045 mmol,
1 equiv) and diisopropylethyl amine (0.016 lL, 0.090
mmol, 2.0 equiv), in CH2Cl2 (0.5 mL) at 0 ꢁC under

R. Chang et al. / Carbohydrate Research 341 (2006) 1998–2004
Table 1. Fitting parameters for CS inhibition by 2
2003
argon. The reaction was stirred for 5 min, then diluted
with CH2Cl2 (20 mL), washed with satd NH4Cl (1 · 5
mL), and back-extracted with CH2Cl2 (1 · 5 mL). The
extracts were combined, dried over Na2SO4, and con-
centrated to dryness under diminished pressure to afford
the mesylate 10 (0.029 g crude weight, 0.044 mmol,
99%). Crude 10 was dissolved in DMF (0.5 mL); TBAI
(0.170 g, 0.460 mmol, 10.2 equiv) was subsequently
added, and the reaction mixture was heated to reflux
(120 ꢁC). After 12 h, the reaction was diluted with
EtOAc (5 mL) and washed with brine (3 · 5 mL), and
back-extracted with EtOAc (1 · 15 mL). The extracts
were combined, dried over Na2SO4, and concentrated
under diminished pressure. Purification by silica gel
chromatography afforded 11 (0.020 g, 0.028 mmol,
63% over two steps) as a pale yellow oil. Spectral data
were identical to those reported by Nicotra and co-
workers.8i
Best-fit values
Activity in
the absence of 2
Activity in
the presence of 2
Vmax
KM (app)
R2
48,884
1.23
0.98
57,177
10.35
0.98
each new membrane preparation, and the combination
with the highest activity at 30 min was used in the assay.
Concentrations of trypsin typically tested were 0.5, 1.0,
2.0, and 4.0 mg/mL, and trypsin was added to the mem-
brane preparation at a concentration of 1 lL of trypsin
soln for every 5 lL of membrane preparation. Individ-
ual assays were performed in 1.5 mL Eppendorf centri-
fuge tubes.
The standard assay soln used contained UDP-Glc-
NAc (1.0 mM), GlcNAc (40 mM), and digitonin (0.2%
w/v) dissolved in pH 7.5 tris buffer (50 mM) containing
MgCl2 (5.0 mM). For radioactivity based assays, radio-
active substrate (typically 0.125 lCi, transferred to the
Eppendorf as a soln which was then evaporated to dry-
ness under diminished pressure) in 40 lL assay soln
(containing necessary inhibitor) was transferred to each
tube. Trypsin-treated membrane (20 lL) was then added
and the mixture was incubated for 1 h at 30 ꢁC. The
reaction was stopped by the addition of 1 mL cold
(0 ꢁC) aq trichloroacetic acid (10% v/v) and filtered onto
glass fiber filter disks (Whatman GF/C, 25 mm), rinsed
with 7:3 EtOH–1 M aq AcOH (4 · 1 mL) and the
remaining radioactivity on the filter paper was measured
by scintillation counting.
Enzyme activity (in the absence of inhibitor) was typ-
ically 25–30,000 cpm/h, with a time-independent back-
ground of 500–600 cpm. Under these conditions, the
enzyme activity was linear (based on plots of incorpo-
rated radioactivity vs. time) to at least 3 h. Control reac-
tions run in the presence of 0.1 mM polyoxin D or
nikkomycin Z, both of which were known competitive
inhibitors (Ki ꢂ 10 lM) of chitin synthase, always
showed P99% inhibition.
Radioactivity based assays evaluating 2 as an inhibi-
tor of CS were carried out using 4 mM 2 in pH 7.5 tris
buffer, with 3H-UDP-GlcNAc added as described
above. Inhibition assays were carried out at [UDP-Glc-
NAc] = 0.1, 0.2, 0.5, 1.0, 2.0, 5.0, 15, 20, and 25 mM.
Competition curves were subjected to nonlinear least
squares fitting using the Prism3 software package
(GraphPad, Inc., San Diego, CA; see Table 1).
4.6. Chitin synthase assays
Active yeast cultures were temporarily maintained on
agar plates, stored at 4 ꢁC. Cells were cultured in
200 mL YEPG (1% yeast extract, 2% bactopeptone,
2% glucose) medium at 30 ꢁC and allowed to grow to
saturation. An aliquot (10–12 mL) of the saturated med-
ium was transferred to 400 mL of YEPG medium to
give an optical density of 0.15–0.20 and allowed to grow
to an optical density of 0.65–0.70. The cells were washed
with cold water and TM buffer (50 mM trisÆHCl,
2.5 mM MgCl2, pH 7.5) by suspension and centrifuga-
tion (15 min, 2000g). The wet weight of the cells at this
point was typically around 1 g; this weight was used to
determine the vol of buffer in which the final pellet
was suspended (vide infra).
The cells were suspended in 2 mL of TM buffer in a
50 mL plastic centrifuge tube, and glass beads
(0.45 mm) were added until the vol of beads reached
about 3 mm below the liquid’s surface. The tube was
then vortexed 20 · 30 s, with 30 s of cooling on ice be-
tween each vortex; vortexing was performed in a 4 ꢁC
cold room. The broken cells were removed from the bot-
tom of the tube with a glass Pasteur pipet and the glass
beads were rinsed 5–7 · 1.5 mL with TM buffer. The
pooled rinsings were centrifuged at 2000g for 4 min,
the supernatant was removed, and the remaining cell
wall precipitate was washed once more with TM buffer.
The cell-wall free supernatants were combined and cen-
trifuged at 60,000g for 1 h.
The enzyme pellet was suspended in 1.6 mLÆ{gram
wet weight of cells} TM buffer and homogenized thor-
oughly with a glass Dounce homogenizer. The mem-
branes were treated with trypsin (quantified by weight,
10 min, 30 ꢁC) and then treated with 3.0 · {mass of tryp-
sin} trypsin inhibitor. Typically, four different concen-
trations of trypsin/trypsin inhibitor were tested for
Acknowledgements
We thank the NIH (GM60875) and the UC Systemwide
Biotechnology Program for direct support and the NIH
and NSF for infrastructure support (GM62116,

2004
R. Chang et al. / Carbohydrate Research 341 (2006) 1998–2004
7. For representative studies, see: (a) Dondoni, A.; Marra,
A.; Pasti, C. Tetrahedron: Asymmetry 2000, 11, 305–317;
(b) Brooks, G.; Edwards, P. D.; Hatto, J. D. I.; Smale, T.
C.; Southgate, R. Tetrahedron 1995, 51, 7999–8014; (c)
Qiao, L.; Vederas, J. C. J. Org. Chem. 1993, 58, 3480–
3482; (d) Ray, W. J., Jr.; Post, C. B.; Puvathingal, J. M.
Biochemistry 1991, 32, 38–47; (e) Withers, S. G.; Johnson,
L. N.; Martin, J. L. Biochemistry 1990, 29, 10745–10757;
(f) Nicotra, F.; Ronchetti, F.; Russo, G. J. Org. Chem.
1982, 47, 4459–4462; (g) Cerretti, P. Carbohydr. Res. 1981,
94, C10–C13.
8. (a) Stolz, F.; Blume, A.; Hinderlich, S.; Reutter, W.;
Schmidt, R. R. Eur. J. Org. Chem. 2004, 3304–3312; (b)
Wen, X.; Hultin, P. G. Tetrahedron Lett. 2004, 45, 1773–
1775; (c) Stolz, F.; Reiner, M.; Blume, A.; Reutter, W.;
Schmidt, R. R. J. Org. Chem. 2004, 69, 665–679; (d)
Gaurat, O.; Xie, J.; Valery, J.-M. J. Carbohydr. Chem.
2003, 22, 645–656; (e) Tetrahedron Lett. 2000, 41, 1187–
1189; (f) Grugier, J.; Xie, J.; Duarte, I.; Valery, J.-M. J.
Org. Chem. 2000, 65, 979–984; (g) Cipolla, L.; Klaps, E.;
La Ferla, B.; Nicotra, F.; Schmid, W. Carbohydr. Lett.
1998, 3, 173–178; (h) Roe, B. A.; Boojamra, C. G.; Griggs,
J. L.; Bertozzi, C. R. J. Org. Chem. 1996, 61, 6442–6445;
(i) Casero, F.; Cipolla, F.; Lay, L.; Nicotra, F.; Panza, L.;
Russo, G. J. Org. Chem. 1996, 61, 3428–3432; (j) Cipolla,
L.; Lay, L.; Nicotra, F.; Panza, L.; Russo, G. Chem.
Commun. 1995, 1993–1994.
GM61894, CHE-9709183). We thank Professor Peter
Orlean (University of Illinois) for donation of yeast
strains, and Dr. Brad Hayes (UCSD) for technical
assistance.
References
1. The Essentials of Glycobiology; 2nd ed.; Varki, A.,
Cummings, R., Esko, J., Freeze, H., Hart, G., Marth, J.,
Eds., Cold Spring Harbor Press: New York, 1999.
2. For recent reviews, see: (a) Compain, P.; Martin, O. R.
Bioorg. Med. Chem. 2001, 9, 3077–3092; (b) Du, Y.;
Linhardt, R. J.; Vlahov, I. R. Tetrahedron 1998, 54, 9913–
9959; (c) Cipolla, L.; La Ferla, B.; Nicotra, F. Carbohydr.
Polym. 1998, 37, 291–298.
3. For representative overviews of fungal chitin synthase (EC
2.4.1.16): (a) Munro, C. A.; Gow, N. A. R. Med. Mycol.
2001, 39, 41–53; (b) Valdivieso, M. H.; Duran, A.;
Roncero, C. EXS 1999, 87, 55–69; (c) Merz, R. A.;
Horsch, M.; Nyhlen, L. E.; Rast, D. M. EXS 1999, 87, 9–
37; (d) Cabib, E. Adv. Enzymol. 1987, 59, 59–101.
4. For recent reviews of chitin synthase inhibition, see: (a)
Ruiz-Herrera, J.; San-Blas, G. Curr. Drug Targ.–Infect.
Disorders 2003, 3, 77–91; (b) Behr, J. B. Curr. Med.
Chem.–Anti-Infect. Agents 2003, 2, 173.
5. (a) Chang, R.; Yeager, A. R.; Finney, N. S. Org. Biomol.
Chem. 2003, 1, 39–41; (b) Yeager, A. R.; Finney, N. S. J.
Org. Chem. 2004, 69, 613–618; (c) Chang, R.; Moquist, P.;
Finney, N. S. Carbohydr. Res. 2004, 339, 1531–1536; (d)
Yeager, A. R.; Finney, N. S. Bioorg. Med. Chem. 2004, 12,
6451–6460.
6. Armstrong, R. N.; Andre, J. C.; Bessems, J. G. M.
Colloque INSERM 1988, 173, 51–58, Chem. Abstr. 110,
169181.
9. (a) Allwein, S. P.; Cox, J. M.; Howard, B. E.; Johnson, H.
W. B.; Rainier, J. D. Tetrahedron 2002, 58, 1997–2009; (b)
Rainier, J.; Cox, J. M. Org. Lett. 2000, 2, 2707–2709.
10. (a) Adam, W.; Bialas, J.; Hadjiarapoglou, L. Chem. Ber.
1991, 124, 2377; (b) Danishefsky, S.; Halcomb, R. L. J.
Am. Chem. Soc. 1989, 111, 6661–6666.
11. (a) Wong, C.-H.; Wittman, V. J. Org. Chem. 1997, 62,
2144–2147; (b) Moffatt, J. G. Methods Enzymol. 1966, 8,
136–142.
12. Orlean, P. J. Biol. Chem. 1987, 262, 5732–5739.