Synthesis, anticancer and antioxidant activities of some novel N-(benzo[d]oxazol-2-yl)-2-(7- or 5-substituted-2-oxoindolin-3-ylidene) hydrazinecarboxamide derivatives

Article abstract of DOI:10.3109/14756366.2011.556630

A series of N-(benzo[d]oxazol-2-yl)-2-(7- or 5-substituted-2-oxoindolin-3- ylidene) hydrazinecarboxamide derivatives were synthesized by treating N-(benzoxazol-2-yl)hydrazinecarboxamide with different isatin derivatives. The newly synthesized compounds were characterized on the basis of spectral analyses. All the synthesized derivatives (Va-l) were screened for anticancer and antioxidant activities. The results showed the anticancer activity of test compounds against HeLa, IMR-32 and MCF-7 cancer cell lines using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. All the synthetic compounds produced a dose-dependant inhibition of growth of the cells. The IC50 values of some compounds were comparable with standard anticancer agent, cisplatin. All the title compounds effectively scavenged the free radical, α,α-diphenyl-β-picryl hydrazyl. The test compounds having substitution with different halides (electron withdrawing groups) at C5 position showed more potent anticancer and antioxidant activities than those at C7 position. These results indicate that C5-substituted derivatives may be useful for developing antioxidant agents that play a protective role in many pathological conditions such as cancer, diabetes and so on.

Full text of DOI:10.3109/14756366.2011.556630

Journal of Enzyme Inhibition and Medicinal Chemistry, 2011; 26(6): 813–818
© 2011 Informa UK, Ltd.
ISSN 1475-6366 print/ISSN 1475-6374 online
DOI: 10.3109/14756366.2011.556630
ReseaRch aRtIcle
Synthesis, anticancer and antioxidant activities of some novel
N-(benzo[d]oxazol-2-yl)-2-(7- or 5-substituted-2-oxoindolin-3-
ylidene) hydrazinecarboxamide derivatives
Rajyalakshmi Gudipati, Rama Narsimha Reddy Anreddy, and Saranagapani Manda
University College of Pharmaceutical Sciences, Kakatiya University, Warangal, A.P., India
abstract
A series of N-(benzo[d]oxazol-2-yl)-2-(7- or 5-substituted-2-oxoindolin-3-ylidene) hydrazinecarboxamide derivatives
were synthesized by treating N-(benzoxazol-2-yl)hydrazinecarboxamide with different isatin derivatives. The newly
synthesized compounds were characterized on the basis of spectral analyses. All the synthesized derivatives (Va–l)
were screened for anticancer and antioxidant activities. The results showed the anticancer activity of test compounds
against HeLa, IMR-32 and MCF-7 cancer cell lines using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide
(MTT) assay. All the synthetic compounds produced a dose-dependant inhibition of growth of the cells.The IC50 values
of some compounds were comparable with standard anticancer agent, cisplatin. All the title compounds effectively
scavenged the free radical, α,α-diphenyl-β-picryl hydrazyl. The test compounds having substitution with different
halides (electron withdrawing groups) at C5 position showed more potent anticancer and antioxidant activities than
those at C7 position. These results indicate that C5-substituted derivatives may be useful for developing antioxidant
agents that play a protective role in many pathological conditions such as cancer, diabetes and so on.
Keywords: Isatin, benzoxazole, hydrazine, indole, anticancer, antioxidant, MTT, DPPH
Introduction
based drugs formulations. e development of synthetic
compounds, capable of scavenging free radicals, has
been a great success, especially in many pathological
conditions such as cancer, diabetes and so on.
Antioxidants have gained a lot of importance because of
their potential as prophylactic and therapeutic agents in
many diseases. Free radicals are constantly formed as a
result of normal organ functions or excessive oxidative
stress1. High levels of free radicals can cause damage to
biomolecules such as lipids, proteins, enzymes and DNA
in cells and tissues, resulting in mutations that can lead
to malignancy. Damage to DNA by oxidative stress has
been widely accepted as a major cause of cancer2. DNA
mutation is a critical step in carcinogenesis and elevated
levels of oxidative DNA lesions have been observed in
various tumours. e discovery of the role of free radicals
in cancer, diabetes, cardiovascular diseases, autoimmune
diseases, neurodegenerative disorders, aging and other
diseases has led to new medical insight3,4. Minimizing
oxidative damage may be an important approach to the
primary prevention or treatment of these diseases, since
antioxidants may stop the free-radical formation or inter-
rupt an oxidizing chain reaction. is had attracted a
great deal of research interest in therapeutic antioxidant-
Literature survey revealed that isatin (1H-indole-2,3-
dione) possess diverse chemotherapeutic activities such
as anticancer5, antiviral6, anti-HIV7, anti-mycobacterial8,
antibacterial9, anti-inflammatory10 and anticonvulsant11.
Amongtheseproperties,cytotoxicactivityofthismoietyhas
been interestingly published by many researchers12–14
.
In view of above, we have planned to synthesize some
novel 3-(2-(benzoxazol-2-yl carbamoyl) hydrazono)-
substituted–2-oxoindoline derivatives for development
of new anticancer and antioxidant agents.
Materials and methods
General
Meltingpointsweredeterminedinopencapillaries,using
Toshniwal melting point apparatus, expressed in degree
centigrade and are uncorrected. e infrared (IR) spectra
Address for Correspondence: Sarangapani Manda, Ph.D., Kakatiya University, Warangal 506009, India. E-mail: rajyaanreddy@gmail.com
(Received 13 November 2010; revised 23 December 2010; accepted 18 January 2011)
813

814 R. Gudipati et al.
of the compounds were recorded on thermo Nicolet
Nexus 670S series, FT-IR spectrometer using KBr disc.
1H NMR were recorded on an Avance-300 MHz instru-
ment using Tetramethyl silane (TMS) as an internal
standard (chemical shifts δ, ppm), mass spectra were
recorded on an LC-MSD-Trap-SL. e purity of the
compounds was checked on silica gel-coated aluminum
sheets (Merck, Darmstadt, Germany; 1.005554, silica gel
HF254–361,Type 60, 0.25 mm) by thin-layer chromatog-
raphy (TLC). TLC was performed on silica gel G for TLC
(Merck) and spots were visualized by iodine vapour or
by irradiation with ultraviolet light (short wave length,
254 nm). Column chromatography was performed by
using Qualigen’s silica gel for column chromatography
(60–120 mesh).
Cell sciences, Pune, India. ese cell lines were grown and
maintained using suitable (DMEM) media and were grown
in culture medium supplemented with 10% fetal bovine
serum, 1% l-glutamine and 1% penicillin–streptomycin–
amphotericin B antibiotic solution. Cells were seeded in
25cm2 tissue culture flasks (Tarsons, India), at 250,000 cells/
flask in a total volume of 9ml. When confluent, all the cells
were trypsinized (using Trypsin-EDTA; HiMedia, Mumbai,
India) and seeded in 96-well plates (Tarsons, India).
Chemistry—general procedures
Synthesis of benzoxazole-2-amine (II)
To a solution of 2-amino phenol (I) (0.1 mol) in toluene
was added a solution of cyanogen bromide (0.1mol) in
toluene with continuous stirring and the stirring was
continued for 3 hr and completion of the reaction was
monitored by TLC. en, the solid separated was filtered
and washed with carbon tetrachloride and air dried to
give a light purple color solid (II) and recrystallized from
ethyl acetate, yield 69%, MP 116–118°C.
Chemicals
All the solvents, reagents and catalysts used are AR grade.
Isatin, fetal bovine serum, Dulbecco’s modified Eagle’s
medium, penicillin, amphotericin B, and streptomycin
were purchased from Himedia (Mumbai, India). α,α-
Diphenyl-β-picryl hydrazyl (DPPH) and 3-(4,5-dimeth-
ylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT)
were purchased from Sigma Chemical Company (St.
Louis, MO). Substituted isatins were prepared by the
procedures reported in the literature15.
Synthesis of phenyl benzoxazol-2-ylcarbamate (III)
To a solution of phenyl chloroformate (0.1mol) in chloro-
form (40ml) was added 0.1mol of 2-amino-benzoxazole
(II) and triethylamine (0.1mol) dropwise and stirred at
room temperature for 6hr.e reaction mixture was then
concentrated and after cooling 40–50ml of petroleum
ether was added to give a precipitate, which was filtered
and washed with large quantity of water and the separated
solid was air dried. Recrystallized with absolute alcohol to
Cell cultures
eHeLa(cervical), IMR-32(neuronal)andMCF-7(breast)
cancer cell lines were purchased from National Centre for
Table 1. Physical data of all synthesized title compounds (Va–l).
N
O
NH
C
NH
N
O
R1
O
N
H
V (a-1)
R2
S. No
1
Compound
Mol. Formula
C16H11O3N5
C16H10O3N5F
C16H10O3N5Cl
C16H10O3N5Br
C17H10O3N5
C16H10O5N6
C17H11O5N5
C18H13O5N5
C16H10O3N5Cl
C16H10O5N6
C17H10O3N5
C17H11O5N5
R1
R2
H
Mol .wt.
321
% Yield
47
Mp (°C)
278–280
170–172
158–160
220–225
210–211
208–210
258–261
248–250
>320
Va
Vb
Vc
Vd
Ve
Vf
H
2
F
Cl
H
339
42
3
H
356
51
4
Br
H
400
46
5
CH3
NO2
COOH
COOCH3
H
H
334
55
6
H
362
65
7
Vg
Vh
Vi
H
365
64
8
H
379
60
9
Cl
NO2
CH3
356
53
10
11
12
Vj
H
362
69
180–181
232–235
208–210
Vk
Vl
H
334
62
H
COOH
365
67
Journal of Enzyme Inhibition and Medicinal Chemistry

Anticancer activity of isatin derivatives 815
1
give pale pink color needle-like crystals (III), yield 69%,
(Table 1) were confirmed by means of their IR, H NMR
MP 92–94°C.
and mass spectral analysis.
Synthesis of N-(benzoxazol-2-yl) hydrazinecarboxamide (IV)
To 0.1 mol of compound III in absolute ethanol (20 ml),
hydrazine hydrate (99%, 0.2 mol) was added, followed by
a catalytic amount of glacial acetic acid (3 drops). en,
the mixture was refluxed for 3 hrs. Excess solvent was
removed by distillation and poured on to crushed ice to
give a white color solid (IV) recrystallized from ethanol
(49%), MP 258–260°C.
Spectral data of synthesized compounds
3-(2-(Benzoxazol-2-yl carbamoyl) hydrazono)-2-oxoindoline (Va)
IR υ (cm−1): 3255 (N–H), 1709 (C=O), 1603 (C=C), 1457
1
(C=N), 1231 (C–O–C), 1171 (C–N); H NMR (dim-
ethyl sulphoxide [DMSO]-d6) δ ppm: 6.81–7.03 (m,
5H, Ar–H), 7.16–7.21 (t, 1H, Ar–H), 7.34–7.36 (d, 1H,
Ar–H),7.43–7.45 (d, 1H, Ar–H), 10.08 (s, 1H, CONH),
10.68 (s, 1H, CONH), 10.77 (s, 1H, indole NH), 13C
NMR (DMSO-d6) δ ppm: 115.24, 117.40, 117.88,
119.68, 121.46, 122.86, 123.03, 126.46, 132.45, 133.16,
141.71, 146.29, 147.06, 151.12, 163.23, 165.08; ESI: m/z
value 322.0.
Synthesis of 3-(2-(benzoxazol-2-yl carbamoyl)hydrazono)-
2-oxoindoline (Va–l)
To a warm solution of acid hydrazide (IV; 0.01 mol) in
absolute ethanol (15 ml) was added the appropriate
indole-2,3-dione (0.01 mol) in the presence of glacial ace-
tic acid and the reaction mixture was heated under reflux
for 8–12 hr, then allowed to cool to room temperature.
e solid thus formed was separated and recrystallized
from ethanol, and purified by column chromatography
(ethylacetate:hexane), yield 62%, MP 278–284°C). e
chemical structures of the synthesized compounds
N-(benzo[d]oxazol-2-yl)-2-(5-chloro-2-oxoindolin-3-ylidene)
hydrazinecarboxamide (VI c)
IR υ (cm−1): 3247 (N–H), 1733 (C=O), 1677 (C=O), 1502
1
(C=N), 1238 (C–O–C); H NMR (DMSO-d6) δ ppm: 6.96–
6.97(d, 1H, Ar–H), 7.12–7.13 (t, 1H, Ar–H), 7.14–7.16 (m, 2H,
Ar–H), 7.49–7.50 (d, 2H, Ar–H), 8.20 (s, 1H, Ar–H), 12.10 (s,
2H, CONH), 12.25 (s, 1H, indole NH); ESI: m/z value 355.0.
NH2
N
CNBr
toluene
OH
O
NH2
I
II
O
C
Cl
O
chloroform
triethylamine
N
O
C
O
NH
O
III
N
NH2NH2.H2O
Ethanol
O
NH
C
NH
NH2
O
IV
R1
O
O
N
H
R2
Ethanol, AcOH
N
O
NH
C
NH
N
R1
O
N
O
H
V (a-1)
R2
Scheme 1. Synthesis of some novel N-(benzo[d]oxazol-2-yl)-2-(7- or 5-substituted-2-oxoindolin-3-ylidene) hydrazinecarboxamide
derivatives.
© 2011 Informa UK, Ltd.

816 R. Gudipati et al.
(DPPH), at the concentration of 0.2 mM in methanol18.
To the 0.1 ml of test compound (at different concentra-
tions), 1.5 ml of methanol and 0.5 ml of DPPH solution
were added, mixed thoroughly and absorbance was read
at 517 nm against blank. e percent reduction of free-
radical concentration (OD) with different concentration
of test compounds was calculated and was compared
with standard ascorbic acid. e results were expressed
as IC50 values (the concentration of test required to scav-
enge 50% free radicals).
N-(Benzo[d]oxazol-2-yl)-2-(5-bromo-2-oxoindolin-3-ylidene)
hydrazinecarboxamide (VI d)
IR υ (cm−1): 3177 (N–H), 1682 (C=O), 1534 (C=N), 1271
(C–N), 1241 (C–O–C); 6.8–6.9(t, 1H, Ar–H), 7.19–7.20
(m, 3H, Ar–H), 7.46–7.48 (d, 1H, Ar–H), 7.61–7.62 (d, 1H,
Ar–H), 7.8 (s, 1H, Ar–H), 11.17 (s, 1H, CONH), 11.33 (s, 1H,
CONH), 11.58 (s, 1H, indole NH); ESI: m/z value 399.0.
N-(Benzo[d]oxazol-2-yl)-2-(5-methyl-2-oxoindolin-3-ylidene)
hydrazinecarboxamide (V e)
IR υ (cm−1): 3198 (N–H), 1696 (C=O), 750 (C=C–H), 1228
1
(C–O–C); H NMR (DMSO-d6) δ ppm: 6.79–6.96 (m, 5H,
Results and discussion
Ar–H), 7.21–7.22 (d, 2H, Ar–H), 7.36 (s, 1H, Ar–H), 10.07
(s, 1H, CONH), 10.68 (s, 1H, CONH), 10.77 (s, 1H, indole
NH); C NMR (DMSO-d6) δ ppm: 16.04, 114.66, 117.40,
119.18, 120.41, 122.86, 123.03, 123.71, 125.99, 132.08,
132.70, 134.66, 147.05, 151.14, 152.09, 163.03, 165.07; ESI:
m/z value 335.0.
Chemistry
13
In the present study, 12 different novel novel
3-(2-(benzoxazol-2-yl
carbamoyl)
hydrazono)-2-
oxoindoline derivatives (Va–l) were prepared by treating
N-(benzoxazol-2-yl)hydrazinecarboxamide with differ-
ent isatin derivatives. e preparation of the title deriva-
tives is outlined in Scheme 1. e physical data of the all
synthesized compounds were shown in Table 1. All the
synthesized compounds were purified by column chro-
matography using ethyl acetate, chloroform and metha-
nol as solvent and the reactions were monitored by TLC.
e chemical structures of the synthesized compounds
N-(Benzo[d]oxazol-2-yl)-2-(7-chloro-2-oxoindolin-3-ylidene)
hydrazinecarboxamide (VI i)
IR υ (cm−1): 3255 (N–H), 1732 (C=O), 1690 (C=O), 1502
1
(C=N), 1232 (C–O–C), 1144 (C–N); H NMR (DMSO-d6)
δ ppm: 6.75–6.78 (d, 1H, Ar–H), 7.17–7.20 (d, 1H, Ar–H),
7.34–7.37 (d, 1H, Ar–H), 7.42–7.44 (d, 1H, Ar–H), 7.50–7.52
(t, 1H, Ar–H), 7.60–7.61 (d, 1H, Ar–H), 7.7 (s, 1H, Ar–H),
11.15 (s, 1H, CONH), 11.30 (s, 1H, CONH), 11.51 (s, 1H,
indole NH); ESI: m/z value 355.0.
1
(Table 1) were confirmed by means of their IR, H NMR
and mass spectral analysis.
In vitro anticancer activity
e anticancer activity of all the synthesized compounds
(Va–Vl) was evaluated against HeLa, IMR-32 and MCF-7
cancer cell lines using MTT method and were equally
active against the three cell types tested. e IC50 values of
allthecompoundsincludingtheintermediatewereshown
in Table 2. All the synthesized compounds produced a
dose-dependant inhibition of growth of the cells. e IC50
values of all the synthetic test compounds were found
between 13.71 and 44.61 μM and were less than those
of intermediate and isatin. e IC50 of these compounds
were comparable with known anticancer agent, cisplatin.
Among all the test compounds, compounds Vb–d and Vl
have more potent anticancer activity against three test cell
types. Many anticancer drugs are effective against HeLa,
IMR-32 and MCF-7 cells by causing apoptosis through the
expression of caspase-3, generating reactive oxygen spe-
cies and damaging DNA19. Cisplatin causes cytotoxicity in
MCF-7 and HeLa cells by a similar mechanism20.
e results also indicate that the anticancer activity
of all the synthesized compounds varied with structural
modification. e IC50 value of compound Va (having no
substitution at C5, C7 position) was more than those of
compounds Vb–l, indicating that substitution with dif-
ferent functional groups at C5 and C7 positions results
in the synthesis of potent anticancer activity. Among the
all synthetic compounds, C5-substituted compounds
are more potent than those of C7 substitution. Among
the C5-substituted compounds, compounds having
Biological activities
Evaluation of in vitro anticancer activity against HeLa, IMR-32
and MCF-7 cancer cell lines
In vitro anticancer activity of all the title compounds was
evaluated against HeLa, IMR-32 and MCF-7 cancer cell
lines using MTT assay16,17. e cell suspension of 1×105
cells/ml was prepared in complete growth medium.
Stock solutions of synthetic compounds were prepared in
DMSO. e stock solutions were serially diluted with com-
plete growth medium containing 50mg/ml of gentamycin
to obtain working test solution of required concentrations
(having <1% DMSO). e 100 μl of cell suspension was
added to each well of the 96-well tissue culture plates.
e cells were allowed to grow in CO2 incubator (37°C, 5%
CO2, 90% relative humidity) for 24hr. e test materials in
complete growth medium (100 μl) were added after 24hr
incubation to the wells containing cell suspension. After
48hr of treatment with different concentrations of test
compounds, the cells were incubated with MTT (2.5mg/
ml) for 2hr. e medium was then removed and 100 µl
of DMSO were added into each well to dissolve formazan
crystals, the metabolite of MTT. After thorough mixing,
the plate was read at 490nm for optical density that is
directly correlated with cell quantity.
Evaluation of antioxidant activity
For the evaluation of antioxidant activity, we have used
a stable free-radical α,α-diphenyl-β-picryl hydrazyl
Journal of Enzyme Inhibition and Medicinal Chemistry

Anticancer activity of isatin derivatives 817
substitution with different halides (electron-withdraw-
ing groups) showed more potent activity than those at
C7 position. is is not surprising, as C5 substitution
has previously been associated with increased biologi-
studies conducted by Ranjit et al.24. is may be due
to the increased lipophilicity of molecules because of
substitution with electronegative atom such as chloro/
bromo at the C5 position of the aromatic ring23. ese
results suggest that C5 substitution with different halides
(electron-withdrawing groups) increases the anticancer
and antioxidant activities of new 3-(2-(benzoxazol-2-yl
carbamoyl) hydrazono)-2-oxoindoline derivatives.
Damage to DNA by oxidative stress has been widely
accepted as a major cause of cancer2. DNA mutation is
a critical step in carcinogenesis and elevated levels of
oxidative DNA lesions have been observed in various
tumours. However, a very recent review on the effect
of antioxidant supplementation on chemotherapy
suggests that the concurrent use of antioxidants and
chemotherapeutic drugs could diminish the dose-
limiting toxicity of these latter25.
cal activity for a range of indole-based compounds21,22
.
Previous studies have shown that strong electronegative
atom substitution such as chloro/bromo at the C5 posi-
tion of the aromatic ring increases the lipophilicity of
molecules and is responsible for enhanced cytotoxicity
in MTT model23.
Antioxidant activity using DPPH method
e antioxidant or DPPH free-radical scavenging activ-
ity of all the synthesized compounds were performed
using DPPH method and the results were found in
Table 3. All the synthetic compounds produced a
concentration-dependant scavenging of free radical,
DPPH. e IC50 values of all the synthetic test compounds
were found between 14 and 47 μM and were less than
those of intermediate and isatin, indicating that combi-
nation of intermediate (N-(benzoxazol-2-yl) hydrazine
carboxamide) with substituted isatins results in the
development of new 3-(2-(benzoxazol-2-yl carbamoyl)
hydrazono)-2-oxoindoline derivatives with good antioxi-
dant activity. Among all the test compounds, compound
having substitution with electron-withdrawing groups
(Vc, Vb and Vk) have more potent antioxidant activity
against DPPH free radicals. ese results support the
conclusions
A new series of new 3-(2-(benzoxazol-2-yl carbamoyl)
hydrazono)-2-oxoindoline derivatives were successfully
synthesized and were screened for their anticancer and
antioxidant activities. e present study results indicated
the dose-dependent anticancer and antioxidant activities
of all title compounds. Among all the test compounds,
compounds with halides substitution at R1 (C5) position
have more potent anticancer and antioxidant activities.
Table 2. Anticancer activity of synthesized compounds against HeLa, IMR-32 and MCF-7 cancer cells using MTT assay.
N
O
NH
C
NH
N
O
R1
O
N
H
V (a-1)
R2
S. No
1
Compound
R1
R2
IC50 (μM)* (HeLa)
421.9
IC50 (μM)* (IMR-32)
411.8
IC50 (μM)* (MCF-7)
401.85
217.69
41.71
Isatin
IV
2
(Intermediate)
241.75
44.61
232.02
38.46
3
Va
H
H
H
4
Vb
F
Cl
18.82
17.41
21.21
5
Vc
H
16.97
14.65
19.12
6
Vd
Br
H
15.88
13.71
17.89
7
Ve
CH3
NO2
COOH
COOCH3
H
H
21.35
21.36
24.15
8
Vf
H
29.67
33.71
31.05
9
Vg
H
23.58
22.79
24.68
10
11
12
13
14
15
Vh
H
32.39
38.20
35.57
Vi
Cl
25.95
24.84
26.48
Vj
H
NO2
CH3
COOH
23.65
24.34
25.67
Vk
H
20.97
21.02
22.42
Vl
H
18.52
18.81
20.06
Cisplatin
14.18
13.64
15.58
*Values are expresses as means (n=4).
© 2011 Informa UK, Ltd.

818 R. Gudipati et al.
mercaptoacetyl]hydrazono]-1H-2-indolinones. Eur J Med Chem
2003;38:633–643.
6. Debra CQ, Kathy AK, Kern ER. In vitro and in vivo evaluation of
isatin-β-thiosemicarbazone and marboran against vaccinia and
cowpox virus infections. Antiviral Res 2006;71:24–30.
Table 3. Antioxidant activity of synthesized compounds using
DPPH method.
N
O
7. PandeyaSN,SriramD,NathG,DeClercqE.Synthesis,antibacterial,
antifungal and anti-HIV evaluation of Schiff and Mannich bases
of isatin derivatives with 3-amino-2-methylmercapto quinazolin-
4(3H)-one. Pharm Acta Helv 1999;74:11–17.
8. Karali N, Gürsoy A, Kandemirli F, Shvets N, Kaynak FB, Ozbey S
et al. Synthesis and structure-antituberculosis activity relationship
of 1H-indole-2,3-dione derivatives. Bioorg Med Chem
2007;15:5888–5904.
9. Pandeya SN, Sriram D, Nath G, De Clercq E. Synthesis and
antimicrobial activity of Schiff and Mannich bases of isatin and its
derivatives with pyrimidine. Farmaco 1999;54:624–628.
10. Sridhar SK, Ramesh A. Synthesis and pharmacological activities
of hydrazones, Schiff and Mannich bases of isatin derivatives. Biol
Pharm Bull 2001;24:1149–1152.
11. Verma M, Pandeya SN, Singh KN, Stables JP. Anticonvulsant activity
of Schiff bases of isatin derivatives. Acta Pharm 2004;54:49–56.
12. Kara LV, Julie ML, Marie R, Stephen GP, John BB. An investigation
into the cytotoxicity and mode of action of some novel N-alkyl-
substituted isatins. J Med Chem 2007;50:5109–5117
13. Prasad RK, Narsinghani T, Sharma R. QSAR analysis of novel
N-alkyl substituted isatins derivatives as anticancer agents. J Chem
Pharma Res 2009;1:199–204.
14. Raja SV, Changkun H, Hoyun L. Hybrid pharmacophore design
and synthesis of isatin–benzothiazole analogs for their anti-breast
cancer activity. Bioorg Med Chem 2009;17:7585–7589.
15. Bahl AA. Textbook of Organic Chemistry, 5th edn. New Delhi: S.
Chand and Company Ltd, 2004, pp. 364–370.
NH
C
NH
N
O
R1
O
N
H
V (a-1)
R2
S. No
1
Compound
R1
R2
IC50 (μM)
202.8
177.5
46.80
19.75
13.46
26.30
41.60
23.82
22.51
30.54
35.96
22.68
18.13
24.99
8.64
Isatin
2
IV
(Intermediate)
3
Va
H
F
H
4
Vb
H
H
5
Vc
Cl
Br
6
Vd
H
7
Ve
CH3
NO2
COOH
COOCH3
H
H
8
Vf
H
9
Vg
H
10
11
12
13
14
15
Vh
H
Vi
Cl
Vj
H
NO2
CH3
COOH
Vk
Vl
H
H
Ascorbic acid
16. Monks A, Scudiero D, Skehan P, Shoemaker R, Paull K, Vistica
D et al. Feasibility of a high-flux anticancer drug screen using a
diverse panel of cultured human tumor cell lines. J Natl Cancer
Inst 1991;83:757–766.
17. Skehan P, Storeng R, Scudiero D, Monks A, McMahon J, Vistica
D et al. New colorimetric cytotoxicity assay for anticancer-drug
screening. J Natl Cancer Inst 1990;82:1107–1112.
18. Blios MS. Antioxidant determination by the use of stable free
radical. Nature 1958;26:1199–1200.
19. Leong CO, Gaskell M, Martin EA, Heydon RT, Farmer PB, Bibby
MC et al. Antitumour 2-(4-aminophenyl)benzothiazoles generate
DNA adducts in sensitive tumour cells in vitro and in vivo. Br J
Cancer 2003;88:470–477.
20. Osbild S, Brault L, Battaglia E, Bagrel D. Resistance to cisplatin and
adriamycin is associated with the inhibition of glutathione efflux
in MCF-7-derived cells. Anticancer Res 2006;26:3595–3600.
21. Cane A, Tournaire MC, Barritault D, Crumeyrolle-Arias M.
e endogenous oxindoles 5-hydroxyoxindole and isatin are
antiproliferative and proapoptotic. Biochem Biophys Res Commun
2000;276:379–384.
Development of these anticancer agents with significant
antioxidant property may be useful for anticancer drug
development in the future.
acknowledgements
e authors thank the University Grants Commission
(UGC), New Delhi, India, for providing the RGNF
(Rajiv Gandhi National Fellowship) Junior Research
Fellowship. ey also thank the Central Instrumentation
Centre, Kakatiya University, Warangal, and Laila Impex,
Vijayawada, India, for providing the spectral data.
Declaration of interest
e authors declared no conflict of interest.
22. Lee D, Long SA, Murray JH, Adams JL, Nuttall ME, Nadeau DP
et al. Potent and selective nonpeptide inhibitors of caspases 3 and
7. J Med Chem 2001;44:2015–2026.
References
23. Hari HP, Umashankar D, Wilson JQ, Masami K, Hiroshi S, Jonathan
RD. Cytotoxic 3,5-bis(benzylidene)piperidin-4-ones and N-acyl
analogs displaying selective toxicity for malignant cells. Eur J Med
Chem 2008;43:1–7.
24. Ranjit K, Rao GK, Pai PNS. Synthesis and biological evaluation of
N1-[(3z)-5-substituted-2-Oxo-1, 2-dihydro-3H-indol-3-ylidene]-
1. Valko M, Rhodes CJ, Moncol J, Izakovic M, Mazur M. Free radicals,
metals and antioxidants in oxidative stress-induced cancer. Chem
Biol Interact 2006;160:1–40.
2. Drorge W. Free radicals in the physiological control of cell function.
Physiol Rev 2002;82:47–95.
3. Ratnam DV, Ankola DD, Bhardwaj V, Sahana DK, Kumar MN. Role
of antioxidants in prophylaxis and therapy: A pharmaceutical
perspective. J Control Release 2006;113:189–207.
5H-dibenzo [b,f] azepine-5-carbohydrazides. Int
2010;4:19–26.
J Biol Chem
25. Block KI, Koch AC, Mead MN, Tothy PK, Newman RA,
Gyllenhaal C. Impact of antioxidant supplementation on
chemotherapeutic efficacy: a systematic review of the evidence
from randomized controlled trials. Cancer Treat Rev 2007;33:
407–418.
4. Suzen S. Antioxidant activities of synthetic indole derivatives
and possible activity mechanisms. Topic Heterocyclic Chem
2007;11:145–178.
5. Gürsoy A, Karali N. Synthesis and primary cytotoxicity
evaluation
of
3-[[(3-phenyl-4(3H)-quinazolinone-2-yl)
Journal of Enzyme Inhibition and Medicinal Chemistry