Discovery of N-(4′-(indol-2-yl)phenyl)sulfonamides as novel inhibitors of HCV replication

Article abstract of DOI:10.1016/j.bmcl.2013.04.050

A series of novel 2-phenylindole analogs were synthesized and evaluated for activity in subgenomic HCV replicon inhibition assays. Several compounds containing small alkyl sulfonamides on the phenyl ring exhibiting submicromolar EC₅₀ values against the genotype 1b replicon were identified. Among these, compound 25d potently inhibited the 1b replicon (EC₅₀ = 0.17 μM) with 147-fold selectivity with respect to cytotoxicity. Compound 25d was stable in the presence of human liver microsomes and had a good pharmacokinetic profile in rats with an IV half-life of 4.3 h and oral bioavailability (F) of 58%.

Full text of DOI:10.1016/j.bmcl.2013.04.050

Bioorganic & Medicinal Chemistry Letters 23 (2013) 3942–3946
Contents lists available at SciVerse ScienceDirect
Bioorganic & Medicinal Chemistry Letters
journal homepage: www.elsevier.com/locate/bmcl
Discovery of N-(40-(indol-2-yl)phenyl)sulfonamides as novel
inhibitors of HCV replication
⇑
Guangming Chen , Hongyu Ren, Anthony Turpoff, Alexander Arefolov, Richard Wilde,
James Takasugi, Atiyya Khan, Neil Almstead, Zhengxian Gu, Takashi Komatsu, Connie Freund,
Jamie Breslin, Joseph Colacino, Jean Hedrick, Marla Weetall, Gary M. Karp
PTC Therapeutics, 100 Corporate Court, South Plainfield, NJ 07080, United States
a r t i c l e i n f o
a b s t r a c t
Article history:
Available online 30 April 2013
A series of novel 2-phenylindole analogs were synthesized and evaluated for activity in subgenomic HCV
replicon inhibition assays. Several compounds containing small alkyl sulfonamides on the phenyl ring
exhibiting submicromolar EC50 values against the genotype 1b replicon were identified. Among these,
Keywords:
HCV inhibitors
Replicon
N-(Indol-2-yl)phenyl sulfonamide
Structure–activity relationship
compound 25d potently inhibited the 1b replicon (EC50 = 0.17 lM) with 147-fold selectivity with respect
to cytotoxicity. Compound 25d was stable in the presence of human liver microsomes and had a good
pharmacokinetic profile in rats with an IV half-life of 4.3 h and oral bioavailability (F) of 58%.
Ó 2013 Elsevier Ltd. All rights reserved.
Chronic hepatitis C virus (HCV) infection is a significant world-
wide health concern. According to the WHO, an estimated 150 mil-
lion people or ꢀ2% of the world population are currently infected
with HCV.1 Approximately 60–80% of HCV infections develop into
chronic hepatitis which can lead to liver fibrosis, cirrhosis and
hepatocellular carcinoma. In the United States, 3–4 million people
are infected with HCV and HCV infection is the leading cause for
liver transplantation.2 Up to 10,000 deaths per year in the United
States alone are attributed to complications that arise from chronic
HCV infection. Through 2011, the standard of care (SOC) for the
treatment of HCV infection had been combination therapy with
Through a high throughput screening campaign utilizing a re-
porter construct containing the 50-untranslated region (UTR) of
the HCV genome driving the expression of luciferase,10 we identi-
fied several N-phenyl indole analogs that inhibited the expression
of the reporter at single digit lM EC50s (data not shown). The HTS
hits identified in this screen were subsequently optimized for po-
tency utilizing a subgenomic HCV replicon assay system carrying
a luciferase reporter gene.11–13 One of the hits identified, com-
pound 1, was weakly active against the genotype 1b replicon with
an EC50 of 50 lM (Fig. 1). Initial exploration of structure–activity
relationships (SAR) led to the identification of 2, where the 4-
methoxyphenyl group was moved to the indole 2-position and
the indole nitrogen was alkylated with an ethyl group. Further,
the structurally undesirable 3-NO2 group was replaced with a CN
group. This led to a more than 10-fold improvement in potency
pegylated interferon-a and the nucleoside ribavirin. After
48 weeks of treatment with this therapy, HCV patients infected
with genotype 1 achieved only 40–50% sustained virologic re-
sponse (SVR).3,4 Recently, two HCV protease inhibitors, Incivek™
(telaprevir) and Victrelis™ (boceprevir), showing clinical efficacy5
have been approved. The new SOC, comprising pegylated inter-
feron, ribavirin, and a protease inhibitor have increased the SVR
to >70% in patients infected with HCV genotype 1.5,6 However,
the rebound of viremia after cessation of treatment with these di-
rect acting antivirals and the emergence of resistance prompt the
need to develop novel anti-HCV agents that act on new targets
and that can be used in combination with the current therapies
to enhance efficacy and decrease the emergence of resistant viral
variants.7–9
against the replicon with an EC50 of 4.1
tro analog of 2, was significantly less active, with less than 50%
inhibition in the replicon assay at a concentration of 51 M, indi-
lM. Compound 3, the 3-ni-
l
cating the importance of the 3-cyano group for activity. We then
evaluated the effect of the regiochemistry of the pendant methoxy
group attached to the 2-phenyl ring of 2 on activity. Changing the
point of attachment for the 40-methoxy group to either the 20- or
30-positions of the phenyl ring was detrimental to activity against
HCV replication (data not shown). Based on these observations, we
chose compound 2 as the starting point for optimization, focusing
on the 40-substituted-2-phenyl indole core and the results of these
studies are reported herein.
Our goal was to systematically explore the effect of substitution
around the indole ring, including the N-1 and C-4 to C-6 positions
⇑
Corresponding author. Tel.: +1 9089129135.
E-mail address: gchen@ptcbio.com (G. Chen).
0960-894X/$ - see front matter Ó 2013 Elsevier Ltd. All rights reserved.
http://dx.doi.org/10.1016/j.bmcl.2013.04.050

G. Chen et al. / Bioorg. Med. Chem. Lett. 23 (2013) 3942–3946
3943
NO2
CN
NO2
N
O
O
O
N
N
O
O
O
1
2
3
EC50 (1b) = 50 µM
EC50 (1b) = 4.1 µM
EC50 (1b) > 51 µM
Figure 1. Identification of hit 1 and analogs 2 and 3 identified during preliminary SAR exploration and activity against the HCV genotype 1b replicon.
as well as the 2-phenyl ring, on biological activity. We first sur-
veyed various substituents to replace the 40-methoxy group on
the 2-phenyl ring of 2 to establish a preliminary SAR. The synthe-
ses of compounds 7a–f were accomplished through a Suzuki cou-
pling strategy by allowing the key intermediate 6 to react with
4-substitued phenyl bromides or iodides as depicted in Scheme 1.
Compound 6 was prepared by treating commercially available 6-
methoxy indole 4 with chlorosulfonyl isocyanate in DMF, leading
to efficient cyanation at the 3-position with 85% yield. Treatment
of 4 with ethyl iodide and sodium hydride in DMF provided 5 in
quantitative yield. This was followed by LDA treatment of a mix-
ture of 5 and triisopropyl borate at ꢁ78 °C to room temperature.
Acidic aqueous workup furnished 6 in quantitative yield. As de-
picted in Scheme 2, the 40-aminophenyl derivative 7c, was con-
verted to carbamate 8a, amides 8b and 8c and sulfonamides 8d
and 8e by treatment with the corresponding acylation or sulfony-
lation reagents. The sultam 9 was prepared by reacting 7c with 3-
chloropropanesulfonyl chloride, followed by base-induced cycliza-
CN
R
NH
N
O
a
CN
8a-e
NH2
N
O
O
CN
O
b, c
S
7c
N
N
O
9
Scheme 2. Reagents and conditions: (a) acyl chloride or chloroformate or sulfonyl
chloride, pyridine, CH2Cl2, 0 °C to rt; (b) ClSO2CH2CH2CH2Cl, pyridine, CH2Cl2, 0 °C
to rt; (c) K2CO3, DMF, rt.
O
O
O
O
a
S
S
b
tion (potassium carbonate in DMF) of the c-chloropropanesulfona-
NBoc
I
NH2
I
N
NHBoc
I
N
H
mide intermediate. The sulfamide 12 was prepared in four steps by
treatment of 4-iodoaniline with chlorosulfonyl isocyanate and t-
butanol in dichloromethane to afford N-Boc-40-iodophenylsulfa-
mide 10. Compound 10 was then converted to 11 by alkylation fol-
lowed by cyclization upon treatment with bromochloroethane and
potassium carbonate in DMF. Suzuki coupling of 11 with 6, fol-
lowed by deprotection afforded sulfamide 12 (Scheme 3).
10
11
CN
O
S
O
N
c, d
NH
N
O
12
Evaluation of the compounds in the HCV 1b replicon assay re-
vealed that replacing the 40-methoxy group with either a hydroxy
(7a) or ethoxy (7b) group had no marked effect on activity (Ta-
ble 1). No improvement in activity was achieved either with the
sulfoxide (7d), sulfone (7e), or carboxamide (7f) analogs. We then
turned our attention to nitrogen derivatives and demonstrated that
several aniline derived compounds gave improved activity. Carba-
mate 8a and amide 8b gained ꢀthreefold potency in the replicon
assay. The 40-N-benzoylamide 8c, however, was devoid of activity,
suggesting that a large aromatic group is not tolerated at this posi-
Scheme 3. Reagents and conditions: (a) t-BuOH, chlorosulfonyl isocyanate, Et3N,
CH2Cl2, 0 °C to rt; (b) BrCH2CH2Cl, Cs2CO3, DMF, 70 °C, 2 h; (c) compound 6,
PdCl2(dppf), K2CO3, DMF, H2O, rt; (d) 20% TFA, CH2Cl2, rt, 2 h.
tion. The sulfonamide 8d with an EC50 of 0.47 lM in the replicon
assay, exhibited a nearly ninefold improvement in potency com-
pared to the initial hit compound 2. Compounds were also evalu-
ated in parallel for cytotoxicity in replicon-containing Huh7 cells,
the same cells as those used in the replicon assay. Good selectivity
CN
CN
a, b
c
B(OH)2
N
H
N
O
O
N
O
5
4
6
CN
X
R
R
N
O
d
7a-f
Scheme 1. Reagents and conditions: (a) chlorosulfonyl isocyanate, DMF, 0 °C to rt; (b) EtI, NaH, DMF, rt; (c) (i-PrO)3B, THF, LDA, then HCl, ꢁ78 °C to rt; (d) PdCl2(dppf), K2CO3,
DMF, H2O, rt.

3944
G. Chen et al. / Bioorg. Med. Chem. Lett. 23 (2013) 3942–3946
Table 1
5
Activity of selected 40-substituted-3-cyano-2-phenylindoles
i, j
CN
CN
R
a, b, c
d, e
N
O
R1O
HO
NO2
N
H
R1O
N
a
a
Compd
R
HCV replicon 1b EC50
(l
M)
CC50 (lM)
13a: R1 = Et
1 = F2HC
14a:
14b:
R
R
1 = Et
2
OMe
OH
OEt
NH2
4.1
6.1
3.0
7.7
4.0
>100
50
>100
100
52
1 = F2HC
13b:
R
7a
7b
7c
7d
7e
7f
8a
8b
8c
8d
14c: R1 = FCH2CH2
f
SOMe
SO2Me
CONH2
NHCO2Et
NHCOMe
NHCOPh
NHSO2Et
2.6
7.8
1.3
1.3
>100
0.47
42
>100
41
89
>100
62
CN
CN
g, h
NHSO2R2
B(OH)2
N
R1O
R1O
N
15a-c
O
O
24, 25a-k, 26
S
9
2.0
>50
30
∗
N
Scheme 4. Reagents and conditions: (a) HCF2Cl, NaOH (20%), dioxane, 80 °C, 80%, or
K2CO3, EtI, MEK, reflux, 99%; (b) DMF–DMA, pyrolidine, DMF, 110 °C; (c) H2, Pd/C,
EtOAc, 60 psi, rt; (d) chlorosulfonyl isocyanate, DMF, 0 °C to rt; (e) EtI, Cs2CO3, DMF,
rt; (f) (i-PrO)3B, THF, LDA, then HCl, ꢁ78 °C to rt; (g) PdCl2(dppf), K2CO3, DMF, H2O,
4-iodoaniline, rt; (h) R2SO2Cl, pyridine, CH2Cl2, 0 °C to rt; (i) BBr3, CH2Cl2, ꢁ78 °C to
rt; (j) FCH2CH2Br, NaH, DMF, 0 °C to rt.
O
O
S
12
0.90
NH
∗
N
a
See Ref. 13 for assay conditions.
with respect to cytotoxicity was maintained for these compounds,
with the sulfonamide 8d possessing a selectivity index of >130.
Cyclization of the sulfonamide functionality led to a small decrease
in activity; sultam 9 was ꢀfourfold less active than was sulfon-
amide 8d. Interestingly, compound 12, a cyclic sulfamide derived
by replacing a methylene group in 9 with an NH, led to a twofold
gain in replicon activity, demonstrating submicromolar EC50
potency.
the 6-chloromethyl derivative with thionyl chloride, followed by
treatment with morpholine (Scheme 5).
It is readily apparent that substitution with lipophilic groups on
the indole benzenoid ring is favored as the unsubstituted com-
pound 16 showed only modest activity (EC50 = 9.0
licon assay (Table 2). The 6-methoxy analog 8d is nearly 20-fold
more potent (EC50 = 0.47 M) than 16. The related 6-methoxy iso-
propanesulfonamide 8e, is nearly equipotent (EC50 = 0.65 M).
lM) in the rep-
l
l
Based on these encouraging results, we focused our efforts on
the sulfonamide series for further optimization. In order to inves-
tigate the effect of various functional groups and substitution pat-
terns on the indole benzenoid ring towards activity in the replicon
assay, we prepared a number of substituted N-(40-(1-ethylindol-2-
yl)phenyl)sulfonamide derivatives with a range of electronic, ste-
ric, and hydrophilic properties.
Moving the methoxy group to the 5-position (17) led to a more
than 10-fold loss in activity. Introducing an additional methoxy
group at the 5-position (18 vs 8d) also leads to reduced potency
against the replicon. In general, compounds containing fluorinated
substituents, for example, 23, 25a, 26, and 27, had good potencies
against the replicon (EC50 range 0.29–0.59
ity with respect to cytotoxicity (50- to 140-fold). The 5-fluoro ana-
log 20 (EC50 = 0.59 M) is much more potent than the
corresponding 5-chloro analog 19 (EC50 = 7.5 M). Introduction of
a polar carboxylic acid group at the indole 6-position (29) led to
a complete loss of activity (EC50 >11 M) while the 6-carboxamide
lM) and good selectiv-
Compounds 16–21, 23, and 27 were synthesized from the corre-
sponding commercially available indoles following the synthetic
sequence outlined in Scheme 1. Compounds 24, 25a–k, and 26
were prepared as shown in Scheme 4. The 6-ethoxyindole and 6-
difluoromethoxyindole compounds were prepared by converting
4-methyl-3-nitrophenol to 4-ethoxy-2-nitrotoluene via ethylation
and 4-difluoromethoxy-2-nitrotoluene via difluoromethylation14
with Freon 22 and NaOH in dioxane, respectively. Batcho–Leimgr-
uber indole synthesis provided the indole intermediates 13a and
13b.15 Cyanation and N-ethylation furnished 14a and 14b. The 6-
fluoroethoxyindole intermediate 14c was obtained by BBr3
demethylation of 5 followed by O-alkylation with 1-bromo-2-fluo-
roethane in the presence of NaH in DMF. Compounds 14a–c were
then converted to boronic acids 15a–c. Suzuki coupling of 15a–c
with 4-iodoaniline followed by the treatment with sulfonyl chlo-
rides furnished compounds 24, 25a–k and 26. Compound 22 was
obtained by BBr3 demethylation of 8d. The 6-carboxylic acid deriv-
ative 29 was obtained from commercially available methyl indole-
6-carboxlate using chemistry described in Scheme 5. Carboxamide
30 was obtained from 29 via the acid chloride followed by treat-
ment with ammonia. Borane reduction of 29 provided the 6-
hydroxymethyl analog 31. Methylation of 31 with methyliodide
and NaH furnished the 6-methoxymethyl analog 32. The 6-mor-
pholinomethyl derivative 33 was obtained by converting 31 to
l
l
l
30 showed only marginal activity. In general, hydrophilic groups
are not well tolerated. Compounds 31–33 containing hydroxy-
methyl, methoxymethyl and morpholinomethyl groups, respec-
tively, have only modest activity against HCV replication (EC50
range 3–5 lM).
Based on the very encouraging activity of the 6-difluorome-
thoxy derivative 25a, we targeted several additional analogs of
compound 25a for further evaluation. We prepared and evaluated
the activity of compounds bearing small alkyl groups both on the
indole nitrogen and the sulfonamide moiety. Several additional
analogs were identified as potent HCV replicon inhibitors with
EC50s <0.3 lM (Table 3). Compounds containing small lipophilic
substituents on the indole N-1 have similar potency against the
replicon, including ethyl, n-propyl, isopropyl, cyclobutyl, and
cyclopropylmethyl. These compounds contain substituents on the
sulfonamide moiety including ethyl, n-propyl, isopropyl, and
cyclopropyl. Compound 25d was selected as an advanced lead
compound considering its potential for further evaluation based
on its favorable overall profile, including potency against HCV rep-
lication (EC50 = 0.17 lM), excellent selectivity with respect to cyto-

G. Chen et al. / Bioorg. Med. Chem. Lett. 23 (2013) 3942–3946
3945
CN
CN
d, e, f
a, b, c
MeO
NHSO2Et
B(OH)2
MeO
R
N
H
N
N
O
O
O
29: R = OH
30: R = NH2
28
1. COCl2
2. NH3, H2O
CN
CN
g
h
NHSO2Et
NHSO2Et
HO
R
N
N
31
32, R = OMe
33, R =
O
N
∗
Scheme 5. Reagents and conditions: (a) chlorosulfonyl isocyanate, DMF, 0 °C to rt; (b) EtI, Cs2CO3, DMF, rt; (c) (i-PrO)3B, THF, LDA, then HCl, ꢁ78 °C to rt; (d) PdCl2(dppf),
K2CO3, DMF, H2O, 4-iodoaniline, rt; (e) EtSO2Cl, pyridine, CH2Cl2, rt; (f) NaOH, MeOH, 60 °C, 1 h; (g) BH3ꢂTHF, rt; (h) NaH, MeI or SOCl2, CH2Cl2, then morpholine, rt.
Table 2
Table 3
Activity of selected N-(40-(3-cyanoindol-2-yl)phenyl)sulfonamides
Activity of selected N-(40-(3-cyano-6-difluoromethoxyindol-2-yl)phenyl)sulfona-
mides
CN
O
O
CN
O
S
R2
O
R1
NH
S
R2
F
N
NH
N
F
O
R3
Compd R1
R2
HCV replicon 1b EC50
(l
M) CC50 (lM)
a
a
a
a
Compd
R2
R3
HCV replicon 1b EC50
(
lM)
CC50 (lM)
16
8d
8e
17
18
19
20
21
22
23
24
25a
26
27
29
30
31
32
H
Et
Et
9.0
0.47
40
62
70
36
>100
40
39
55
55
18
42
20
39
24
>100
55
60
6-OMe
6-OMe
5-OMe
5,6-(OMe)2
5-Cl
25a
25b
25c
25d
25e
25f
25g
25h
25i
Et
Et
Et
Et
i-Pr
c-PrCH2
c-PrCH2
c-Bu
n-Pr
i-Pr
Et
Et
Et
0.29
0.20
0.30
0.17
0.19
0.25
0.075
0.22
0.10
0.12
0.08
20
12
13
25
20
i-Pr 0.65
i-Pr 7.4
Et
Et
Et
Et
Et
Et
Et
Et
Et
Et
Et
Et
Et
Et
4.0
7.5
0.59
3.5
2.0
0.36
0.53
0.29
0.59
0.17
>11b
9.0
c-Pr
c-Pr
c-Pr
c-Pr
n-Pr
c-Pr
i-Pr
i-Pr
5-F
4-Cl
>100
13
6-OH
6-CF3
6-OEt
6-OCHF2
6-OCH2CH2F
6-OCF3
26
23
19
22
25j
25k
c-PrCH2
a
See Ref. 13 for assay conditions.
6-COOH
6-CONH2
6-CH2OH
6-CH2OMe
3.5
5.0
>100
the reduction in HCV RNA was quantified (EC50 = 0.18 l
M),16 con-
O
33
Et
3.0
35
sistent with activity derived from the luciferase readout. Com-
pound 25d was metabolically stable to human liver microsomes
and had a good pharmacokinetic profile in the rat with an IV
half-life and clearance of 6.3 h and 4.5 mL/min/kg, respectively,
and with an oral bioavailability of 58% (Table 4). Compound 25d
was evaluated for inhibitory activity against HCV protease and
polymerase enzymatic inhibition assays and was inactive against
N
∗
6-
a
See Ref. 13 for assay conditions.
Highest concentration tested.
b
toxicity (147-fold), sufficient metabolic stability and sufficiently
high exposure in the rat. The anti-HCV replicon activity was further
confirmed in a subgenomic monocistronic replicon assay in which
these enzymes at concentrations up to 10
tration tested.
lM, the highest concen-
Table 4
Activity and DMPK profile of 25d
a
b
a
c
HCV replicon 1b EC50
M)
HCV replicon 1b RNA EC50
M)
CC50
M)
HLM metabolism, Clint (mL/
min/kg)
Rat PKd
(l
(l
(
l
IV
Vss (L/
PO
AUC0–inf
M h)
6.8
%F
58
T1/2
CL (mL/min/ Cmax (lg/
(h)
kg)
kg)
mL)
(l
0.17
0.18
25
<1
6.3
2.2
4.5
0.77
a
b
c
See Ref. 13 for assay conditions.
See Ref. 16 for assay conditions.
See Ref. 17 for assay conditions.
d
Dosed in a solution of PEG-300, 3 mg/kg PO and 1 mg/kg IV to female Sprague–Dawley rats.

3946
G. Chen et al. / Bioorg. Med. Chem. Lett. 23 (2013) 3942–3946
2. Ghobrial, R. M.; Steadman, R.; Gornbein, J.; Lassman, C.; Holt, C. D.; Chen, P.;
In summary, we have identified a novel series of N-(40-(indol-2-
Farmer, D. G.; Yersiz, H.; Danino, N.; Collisson, E.; Baquarizo, A.; Han, S. S.; Saab,
S.; Goldstein, L. I.; Donovan, J. A.; Esrason, K.; Busuttil, R. W. Ann. Surg. 2001,
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yl)phenyl)sulfonamides with potent and selective activity against
the HCV 1b replicon. Through preliminary SAR optimization, sev-
eral compounds with submicromolar activity against the replicon
have been identified. Compounds from this class generally are
metabolically stable in microsomes and have good exposure in
the rat. Compound 25d was profiled to assess the potential develo-
pability of this scaffold. This class of novel compounds, represented
by 25d, has no activity against the HCV protease or polymerase en-
zymes. Results of further optimization of this class of compounds
and the selection and characterization of resistant replicon variants
to identify the viral target and begin to elucidate the mechanism of
action will be reported in a subsequent publication.18
3. McHutchison, J. G.; Lawitz, E. J.; Shiffman, M. L.; Muir, A. J.; Galler, G. W.;
McCone, J.; Nyberg, L. M.; Lee, W. M.; Ghalib, R. H.; Schiff, E. R.; Galati, J. S.;
Bacon, B. R.; Davis, M. N.; Mukhopadhyay, P.; Koury, K.; Noviello, S.; Pedicone,
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13. Huh7 cells harboring a genotype 1b HCV bicistronic replicon were plated at
5000 cells/well in 96 well plates remained subconfluent for the duration of the
experiment. Compounds were added to the plates with a final concentration of
0.5% DMSO and plates were incubated at 37 °C. Luciferase activity was
measured after 2 days. Cytotoxicity was evaluated in parallel by MTS assay in
the genotype 1b HCV replicon-containing Huh7 cells (CellTiter 96Ò Aqueous
Non-Radioactive Cell Proliferation Assay, Promega).
Acknowledgments
The authors would like to thank Dr. Valerie Clausen, Christine
Espiritu and Shirley Yeh for their support during the course of this
work.
14. Miller, T. G.; Thanassi, J. W. J. Org. Chem. 2009, 1960, 25.
15. Batcho, A. D.; Leimgruber, W. Org. Synth. 1985, 63, 214.
A. Supplementary data
16. Huh7 cells harboring a genotype 1b HCV monocistronic replicon were plated at
5000 cells/well in 96 well plates. Compounds were added to the plates with a
final concentration of 0.5% DMSO and plates were incubated at 37 °C. Cells
were harvested 3 days post dosing and replicon RNA was quantified by real
time RT-PCR with GAPDH RNA as an endogenous control.
Supplementary data associated with this article can be found, in
the
online
version,
at
http://dx.doi.org/10.1016/j.bmcl.
2013.04.050. These data include MOL files and InChiKeys of the
most important compounds described in this article.
17. Compounds were incubated at 1
protein concentration) for 0, 10, 20, 30 and 60 min, in the presence of 1 mM
EDTA, 3 mM MgCl2, 1.3 mM NADP, 3.3 mM -glucose-6-phosphate and 1 unit/
lM with human liver microsomes (0.5 mg/mL
D
mL of glucose-6-phosphate dehydrogenase. Incubated samples were
centrifuged at 2000 rpm and the supernatants were analyzed by LC/MS.
18. Zhang, X.; Zhang, N.; Chen, G.; Turpoff, A.; Ren, H.; Takasugi, J.; Morrill, C.; Zhu,
J.; Li, C.; Lennox, W.; Paget, S.; Liu, Y.; Almstead, N.; Njoroge, F. G.; Gu, Z.;
Komatsu, T.; Clausen, V.; Espiritu, C.; Graci, J.; Colacino, J.; Lahser, F.; Risher, N.;
Weetall, M.; Nomeir, A.; Karp, G. M. Bioorg. Med. Chem. Lett. 2013. http://
dx.doi.org/10.1016/j.bmcl.2013.04.049.
References and notes
1. (a) Alter, M. J. World J. Gastroenterol. 2007, 13, 2436; (b) Kim, A. Y.; Timm, J.
Expert Rev. Anti-Infect. Ther. 2008, 6, 463; (c) Almasio, P. L.; Ingrassia, D.;
Vergara, B.; Filosto, S. Expert Rev. Anti-Infect. Ther. 2008, 6, 775; (d) Hepatitis C
fact sheet No. 164, July 2012, www.who.int.