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T. Jiang et al. / Bioorg. Med. Chem. Lett. 16 (2006) 2109–2112
10
Table 3. Antiviral activities (EC50, lM) of selected oxindoles against HIV-1-resistant mutants
Compound
WT
L100I
K103N
V106A
I135T
I135V
E138K
V179E
Y181C
Y188L
F227C
F227L
Efavirenz
Nevirapine
0.0005
0.050
0.027
0.006
0.008
0.023
0.003
0.018
0.016
0.008
0.010
0.010
0.164
0.260
0.008
0.174
0.277
0.178
2.087
0.100
0.228
0.058
0.032
5.053
>10
0.004
8.458
0.630
0.513
0.259
0.166
0.149
2.516
0.147
0.041
0.102
0.001
0.207
0.236
0.048
0.127
0.046
0.016
0.076
0.068
0.037
0.055
0.001
0.079
0.059
0.017
0.026
0.014
<0.003
0.055
0.263
0.029
0.047
0.002
0.031
0.052
0.030
0.045
0.032
0.020
0.028
0.038
0.026
0.071
0.006
0.116
2.465
0.324
0.898
0.048
0.088
0.101
0.060
0.010
0.483
0.0011
>10
0.28
>10
0.008
0.733
0.957
0.142
0.528
0.145
0.578
0.658
0.313
0.087
2.075
0.001
0.148
0.063
0.002
0.013
0.048
0.088
2.354
0.365
0.014
0.381
9
9
9
9
9
1
1
1
1
c
3.070
0.031
3.227
0.134
0.085
0.265
0.063
0.120
0.717
>10
1.252
>10
o
0.100
>10
z
ac
ae
0a
0b
2b
2c
1.928
11.096
14.280
2.240
0.696
2.346
6.518
22.638
23.106
1.969
1.068
>10
activity against L100I, I135T, I135V, E138K, V179E,
and F227L mutant viruses. However, similar to nevira-
pine and efavirenz, these oxindole analogs exhibited
poor antiviral activity against K103N and Y188L. In
general, the oxindoles are not as potent as EFV toward
these mutants but are superior to NVP. A few of them,
such as 9o and 12b have significantly improved mutant
profiles compared to nevirapine. Further optimization
would be required to achieve potency in all of these
NNRTI-resistant mutant viruses.
6. Miller, V.; Ait-Khaled, M.; Stone, C.; Griffin, P.; Meso-
giti, D.; Cutrell, A.; Harrigan, R.; Staszewski, S.; Katla-
ma, C.; Pearce, G.; Tisdale, M. AIDS 2000, 14, 163.
7
8
9
. Pauwels, R. Curr. Opin. Pharmacol. 2004, 4, 437.
. Bacheler, L. T. Drug Res. Updates 1999, 2, 56.
. Jiang, T.; Kuhen, K. L.; Wolff, K.; Yin, H.; Bieza, K.;
Caldwell, J.; Bursulaya, B.; Wu, T. Y.-H.; He, Y. Bioorg.
Med. Chem. Lett. 2006, 16, 0000.
1
0. Antiviral efficacy assay: Compounds were serially diluted
in DMSO and added to adherent HEK293T target cells
prior to addition of VSV-g pseudotyped HIV-1 luciferase
reporter virus (HIV-1 pseudovirions) harvested from 293T
producer cells following a triple transient transfection
In vitro studies suggested that many of these heterocy-
cle-containing analogs have improved water solubility
and metabolic stability. Compound 9z was also studied
for its pharmacokinetic properties in vivo. Compared to
ester 1, the pyridine analog 9z showed significantly im-
proved exposure (Table 2).
(
CaP, Clontech) of the three plasmid HIV-1 lentiviral
vector system comprised of the VSV-g envelope expression
plasmid, packaging construct (delta psi), and the HIV-1
LTR:Luc plasmid. The VSV-g envelope expression plas-
mid generates the pseudovirus receptor that permits a
broad tropism and mediates entry into the 293T target
cells. The delta psi packaging construct supplies all of the
structural and regulatory gene products needed to gener-
ate the pseudovirus. The viral vector RNA synthesized
from the HIV-1 LTR:Luc plasmid possesses the cis RNA
packaging signal (psi sequence) in addition to the lucifer-
ase reporter gene and the HIV-1 LTR. The supernatants
of transfected producer cells contain HIV-1 pseudovirions
carrying only the luciferase gene in the viral genome.
Upon transduction of the target 293T cells, the viral
genomic RNA will undergo reverse transcription, nuclear
translocation, integration, and transcription of the
integrated luciferase gene driven by the PGK (phospho-
glycerate kinase promoter). Luciferase activity using
Bright-Glo reagent (Promega) substrate was measured
48 h post-infection using a CLIPR plate reader (Molecular
Devices) to determine EC50 values.
In summary, following a lead from previous studies, a
series of oxindoles with aromatic moieties in the place
of metabolically unstable ester moiety was synthesized,
and a number of these analogs exhibited potent antiviral
activity toward wild-type virus as well as certain drug-
resistant mutants. Among these, compound 9z also
exhibited promising pharmaceutical properties.
References and notes
1
. St. Clair, M.; Martin, J. L.; Tudor-Williams, G.; Bach, M.
C.; Vavro, C. L.; King, D. M.; Kellam, P.; Kemp, S. D.;
Larder, B. A. Science 1991, 253, 1557.
2
3
4
. Sebastian, J.; Faruki, H. Med. Res. Rev. 2004, 24, 115.
. Gotte, M. Exert Rev. Anti-Infect. Ther. 2004, 2, 707.
. Mugavero, M. J.; Hicks, C. B. Drug Discovery Today:
Ther. Strategies 2004, 1, 529.
11. All compounds reported are racemic, and only one
enantiomer is shown. Data are based on the measurement
of the racemic mixture.
12. Flexible docking was conducted using Glide 2.0 (Schro-
dinger, Inc., Portland, OR, 2002). The protein coordi-
nates were taken from protein databank (pdb code
1FK9).
5
. Rusconi, S.; La Seta Catamancio, S.; Citterio, P.; Bulghe-
roni, E.; Kurtagic, S.; Galazzi, M.; Croce, F.; Moroni, M.;
Galli, M. Antiviral Ther. 2001, 6, 41.