Novel quinolines and pyrimido[4,5-b]quinolines bearing biologically active sulfonamide moiety as a new class of antitumor agents

Article abstract of DOI:10.1016/j.ejmech.2009.11.021

Some novel quinolines and pyrimido[4,5-b]quinolines have been synthesized. The structures of which were confirmed by elemental analyses and spectral data. All the target compounds were subjected to in-vitro antitumor activity against Ehrlich Ascites Carcinoma (EAC) cells. Compounds 24, 19 and 12 showed higher activity with IC₅₀ values (5.5, 6.9, 7 μg/ml) when compared with Doxorubicin as a reference drug (IC₅₀ value 38 μg/ml).

Full text of DOI:10.1016/j.ejmech.2009.11.021

European Journal of Medicinal Chemistry 45 (2010) 738–744
Contents lists available at ScienceDirect
European Journal of Medicinal Chemistry
journal homepage: http://www.elsevier.com/locate/ejmech
Original article
Novel quinolines and pyrimido[4,5-b]quinolines bearing biologically active
sulfonamide moiety as a new class of antitumor agents
,
Saleh I. Alqasoumi a, Areej M. Al-Taweel b, Ahmed M. Alafeefy c, Eman Noaman d, Mostafa M. Ghorab a
*
a Medicinal, Aromatic and Poisonous Plants Research Center (MAPPRC), College of Pharmacy, King Saud University, P.O.Box 2457, Riyadh 11451, Saudi Arabia
b Pharmacognosy Department, College of Pharmacy, King Saud University, Saudi Arabia
c Medicinal Chemistry Department, College of Pharmacy, King Saud University, Saudi Arabia
d Radiation Biology Department, National Center for Radiation Research and Technology, Atomic Energy Authority, Nasr City, Cairo, Egypt
a r t i c l e i n f o
a b s t r a c t
Article history:
Some novel quinolines and pyrimido[4,5-b]quinolines have been synthesized. The structures of which
were confirmed by elemental analyses and spectral data. All the target compounds were subjected to in-
vitro antitumor activity against Ehrlich Ascites Carcinoma (EAC) cells. Compounds 24, 19 and 12 showed
Received 17 June 2009
Received in revised form
4 November 2009
Accepted 12 November 2009
Available online 18 November 2009
higher activity with IC50 values (5.5, 6.9, 7
(IC50 value 38 g/ml).
m
g/ml) when compared with Doxorubicin as a reference drug
m
Ó 2009 Elsevier Masson SAS. All rights reserved.
Keywords:
Quinoline
Pyrimidoquinoline
Sulfonamide
Antitumor activity
1. Introduction
benzenesulfonamide and pyrimido[4,5-b](quinoline-10-yl)benze-
nesulfonamide derivatives, bearing potentially active side chains,
such as cyano [11], ureido, thioureido [13] and thione [18] as
analogues of compound E7070 [29] (Fig. 1), to be evaluated as
potential antitumor agents.
Quinoline derivatives were found to possess several pharma-
cological properties, including antibacterial [1–3] and anticancer
[4–10] activities. Also, the chemistry of pyrimidine and fused
pyrimidine derivatives has been of increasing interest, since many
of these compounds exhibited several biological activities and
useful application as antitumor [11–19], and antibacterial agents
[20]. On the other hand, among the wide range of compounds
tested as antitumor agents, sulfonamides have attracted great
attention, as many sulfonamide derivatives were reported to have
interesting antitumor activity [21–25]. Several mechanisms have
been reported for the anticancer activity of the sulfonamide
compounds and the most prominent of these mechanisms was
through the inhibition of the carbonic anhydrase isozymes [26–29].
The mechanism of tumor inhibition by sulfonamide carbonic
anhydrase (CA) inhibitor was suggested by Boyle and Chegwidden
[30], that these compounds may reduce the provision of bicar-
bonate for the synthesis of nucleotides and other cell components
such as membrane lipids. In continuation of our work it seemed of
interest to design and synthesize some novel 4-(quinoline-1-yl)-
2. Results and discussion
2.1. Chemistry
In this investigation a series of new quinolines bearing sulfon-
amide moiety 6–11, 18, 21–24, pyrimido[4,5-b]quinoline attached
to sulfonamide moiety, 12–16, 17, 19 and 20 were designed,
synthesized (Schemes 1–4) and biologically evaluated for their in-
vitro antitumor activity. Thus, condensation of 1,3-cyclohexandione
1 with sulfanilamide 2 gave the corresponding enaminone 3, which
upon reaction with 2-(2,4-dichlorobenzylidene)- malononitrile 4,
in ethanol containing a catalytic amount of triethylamine, yielded
2-aminoquinoline-3-carbonitrile derivative 6. The structure of the
enaminone 3 was established by elemental analyses and spectral
data. IR spectrum of compound 3 showed the presence of the
characteristic bands for (NH, NH2), (C]O) and (SO2). Also, the 1H
NMR spectrum indicated the presence of a singlet at 9.0 ppm which
could be assigned to NH of enaminone 3. IR spectrum of compound
6 exhibited bands for (NH2), (C]O), (SO2) in addition to the
* Corresponding author. Tel.: þ966 534292860; fax: þ966 01 4670560.
E-mail address: mmsghorab@yahoo.com (M.M. Ghorab).
0223-5234/$ – see front matter Ó 2009 Elsevier Masson SAS. All rights reserved.
doi:10.1016/j.ejmech.2009.11.021

S.I. Alqasoumi et al. / European Journal of Medicinal Chemistry 45 (2010) 738–744
739
Fig. 1. Compound E7070, a sulfonamide compound in advanced clinical trials as
anticancer agent.
carbonitrile band. The mass spectrum of 6 revealed a molecular ion
peak m/z at 489 [Mþ] (1.8), with a base peak at 73 (100)
The behavior of compound 6 towards isothiocyanate was
studied. Thus, nucleophilic reaction of compound 6 on the highly
positive carbon of the isothiocyanate RNCS in dry pyridine for (2 h)
yielded the corresponding thioureido derivatives 7–11 (Scheme2),
while 24 h reaction time, furnished the cyclic system pyrimido[4,5-
b]quinoline derivatives 12–16, respectively. Structures of compounds
7–11 were confirmed on the basis of their IR spectra which showed
the presence of (C^N) band at 2164–2182 cmꢀ1. The structure of
compounds 12–16 was established on the basis of elemental
analyses, IR, 1H NMR and mass spectral data. IR spectra of
compounds 12–16 revealed the absence of (C^N) and the presence
Scheme 2.
mass spectrum of compound 18 exhibited a molecular ion peak m/z
at 532 [Mþ] (2.8), with a base peak at 48 (100), while fusion of
compound 6, with urea and/or thiourea, furnished the condensed
pyrimidoquinolines 19 and 20, respectively. Products 19, 20 were
formed via the loss of an ammonia molecule, followed by an
intramolecular addition to the cyano function to give the final
isolated products 19 and 20, respectively. IR spectra of 19 and 20
exhibited the disappearance of a band characteristic for the car-
bonitrile functional group and the presence of bands at 3420–
3209 cmꢀ1 (NH, NH2). The mass spectrum of compound 19 revealed
a molecular ion peak m/z at 532 [Mþ] (2.5), with abase peak at 41
(100). The mass spectrum of compound 20 showed a molecular ion
peak m/z at 548 [Mþ] (2.4), with abase peak at 47 (100).
In addition, the behavior of compound 6 towards succinic
anhydride under different conditions was studied. Thus, the reac-
tion of compound 6 with succinic anhydride in boiling ethanol gave
the acid derivative 21. While carrying out the reaction under the
condition of fusion, the pyrrolo derivative 22 was obtained (Scheme 4).
The structure of compounds 21, 22 was proved on the basis of
elemental analyses and spectral data. IR spectrum of compound 21
revealed bands for (OH), (NH, NH2), (C^N) and (2C]O). 1H NMR
spectrum of 21 exhibited signals at 1.10–1.20 ppm for CH2–CH2,
8.90 ppm (OH). IR spectrum of compound 22 revealed the absence
of OH band and presence of (NH2), (C^N) and (3C]O) bands. 1H
NMR spectrum showed signals at 1.10–1.40 ppm (CH2–CH2). Its
mass spectrum revealed a molecular ion peak m/z at 571 [Mþ] (4.2),
with a base peak at 41 (100).
of (C]S) bands at 1256–1270 cmꢀ1
.
The target ring system 17 was synthesized by reaction of
compound 6 with carbon disulfide in pyridine for long time (48 h)
(Scheme 3). IR spectrum of compound 17 exhibited the absence of
(C^N) band. When compound 6 was allowed to react with urea in
ethanolic sodium ethoxide, a product of the molecular formula
C23H19Cl2N5O4S 18 is formed via the elimination of ammonia, based
on the presence of (C^N) absorption in the IR spectrum. Its IR
spectrum showed bands for (NH, NH2), (C^N) and (2C]O). The
Finally, 2-arylsulfonylaminoquinoline derivatives 23 and 24
were obtained by refluxing compound 6 with 4-nitro and/or 4-
bromobenzenesulfonyl chloride in dry pyridine. The structures of
compounds 23 and 24 were confirmed by IR, 1H NMR and mass
spectral data. IR spectra revealed bands for (C^N). 1H NMR spec-
trum of 23 showed singlet at 8.30 ppm (NH). Mass spectrum of 23
showed a molecular ion peak m/z at 674 [Mþ] (1.6), with a base peak
at 40 (100). Mass spectrum of compound 24 revealed a molecular
ion peak m/z at 708 [Mþ] (3.1), with a base peak at 44 (100).
2.2. In-vitro antitumor activity
Doxorubicin, the reference drug used in this study is one of the
most effective antitumor agents used to produce regressions in
acute leukemia’s, Hodgkin’s disease, and other lymphomas. The
relationship between survival ratio and drug concentration was
Scheme 1.

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S.I. Alqasoumi et al. / European Journal of Medicinal Chemistry 45 (2010) 738–744
Scheme 3.
plotted to obtain the survival curve of Ehrlich Ascites Carcinoma
(EAC) cells. The response parameter calculated was IC50 value
(Table 1), which corresponds to the compound concentration
causing 50% mortality in net cells.
presence of 4-bromobenzenesulfonamide at position-2 of quino-
line ring 24 with cyano group at position-3 increased the cytotoxic
activity which showed the higher potency than the tested
compounds and the reference drug Doxorubicin with (IC50 val-
ue ¼ 38
mg/ml). These results revealed that the nature of substit-
2.2.1. Structure activity relationship
uent at C-2 of the quinoline ring by 4-bromobenzenesulfonamide
has an important role on the cytotoxic activity and potency. On the
other hand the cyclic system pyrimidoquinoline derivative 19
The cytotoxicity of nineteen compounds was examined on
Ehrlich Ascites Carcinoma (EAC) cells. It is clear from the results, the
comparison of cytotoxicity of the quinoline derivatives has shown
that the cell killing potency follows the order quinoline having
bearing urea moiety at position-2 with (IC50 value ¼ 6.9
mg/ml)
exhibited higher potency than the quinoline derivative 18 having
4-bromobenzenesulfonamide 24 with (IC50 value ¼ 5.5
chlorobenzenesulfonamide 23 with (IC50 value ¼ 20 g/ml) > qui-
noline derivative 6 bearing free amino group at position-2 with
(IC50 value ¼ 25 g/ml).
Also, pyrimidoquinoline derivatives follows the order
19 > 12 >15 > 20 with IC50 values (6.9, 7, 10, 25 g/ml). The
m
g/ml) > 4-
urea moiety at position-2 with cyano group at position-3 with (IC50
m
value ¼ 75
pyrimidoquinoline 19 revealed a higher potency than the cyclic
thiourea 20 with (IC50 value ¼ 25 g/ml).
It is very clear from the results that the pyrimidoquinoline 12
bearing aliphatic butyl moiety at position-3 with (IC50 value ¼ 7 g/ml)
mg/ml). In addition it was found that the cyclic urea
m
m
m
m
Scheme 4.

S.I. Alqasoumi et al. / European Journal of Medicinal Chemistry 45 (2010) 738–744
741
Table 1
internal Standard and peak multiplicities are designed as follows: s,
singlet; d, doublet; t, triplet; m, multiplet. Electron impact Mass
Spectra were recorded on a Shimadzu GC-MS-QP 5000 instrument
(Shimadzu, Tokyo, Japan). Elemental analyses were performed on
Carlo Erba 1108 Elemental Analyzer (Heraeus, Hanau, Germany).
In-vitro cytotoxic activity of the newly synthesized compounds 6–24.
b
Compd. No.
Non-viable cells (%)a
Concentration ( g/ml)
IC50 (mg/ml)
m
100
50
25
10
Doxorubicin
6
7
8
100
68 ꢂ 3.3
65 ꢂ 2.2
35 ꢂ 3.2
33 ꢂ 5.1
55 ꢂ 2.4
100
90 ꢂ 4.7
80 ꢂ 3.2
50 ꢂ 3.2
50 ꢂ 3.3
90 ꢂ 5.3
50 ꢂ 5.2
39 ꢂ 3.7
40 ꢂ 3.8
90 ꢂ 2.9
100
32 ꢂ 4.1
50 ꢂ 5.5
30 ꢂ 2.1
30 ꢂ 2.1
50 ꢂ 3.2
60 ꢂ 2.6
50 ꢂ 4.1
70 ꢂ 3.7
40 ꢂ 2.3
30 ꢂ 4.2
60 ꢂ 4.2
30 ꢂ 2.1
30 ꢂ 3.5
35 ꢂ 4.2
80 ꢂ 5.1
50 ꢂ 2.8
35 ꢂ 2.4
50 ꢂ 4.3
85 ꢂ 3.4
90 ꢂ 4.1
19 ꢂ 1.8
40 ꢂ 2.4
30 ꢂ 2.6
10 ꢂ 1.2
40 ꢂ 2.1
30 ꢂ 1.6
50 ꢂ 2.1
70 ꢂ 4.1
30 ꢂ 2.1
10 ꢂ 1.1
50 ꢂ 3.2
30 ꢂ 3.9
11 ꢂ 1.6
20 ꢂ 2.1
80 ꢂ 4.2
30 ꢂ 1.9
20 ꢂ 1.8
20 ꢂ 2.2
50 ꢂ 2.9
90 ꢂ 2.1
38
25
4.1.1. 4-(3-Oxocyclohexenylamino)benzenesulfonamide (3)
95 ꢂ 2.1
40 ꢂ 3.1
40 ꢂ 3.5
95 ꢂ 3.8
100
90 ꢂ 3.6
80 ꢂ 5.1
75 ꢂ 2.1
60 ꢂ 2.3
95 ꢂ 2.3
70 ꢂ 3.3
57 ꢂ 2.7
60 ꢂ 1.3
100
A mixture of 1,3-cyclohexanedione 1 (1.12 g, 0.01 mol) and
sulfanilamide 2 (1.72 g, 0.01 mol) in ethanol (30 ml) was refluxed
for 5 h. The reaction mixture was cooled and then poured onto cold
water, the obtained solid was crystallized from ethanol to give 3:
Yield, 88%; m.p. 236–238 ꢁC; IR, cmꢀ1: 3354, 3263, 2210 (NH, NH2),
3032 (CH arom.), 2940, 2870 (CH aliph.), 1611 (C]O), 1360, 1184
>100c
>100c
25
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
40
25
7
50
50
10
50
(SO2). 1H NMR (DMSO-d6)
d: 1.0–2.2 [m, 6H, 3CH2], 5.5 [s, 1H, CH],
7.0–7.8 [m, 6H, Ar-H þ SO2NH2], 9.0 [s, 1H, NH, D2O-exchangable].
Anal. Calcd. For C12H14N2O3S: C, 54.12; H, 5.30; N, 10.52. Found: C,
53.81; H, 5.62; N, 10.23.
>100c
75
6.9
25
50
25
20
4.1.2. 4-[2-Amino-3-cyano-4-(2,4-dichlorophenyl)-5-oxo-5,6,7,8-
tetrahydro quinolin-1(4H)-yl]benzenesulfonamide (6)
100
60 ꢂ 2.3
90 ꢂ 3.5
90 ꢂ 4.5
100
50 ꢂ 4.8
70 ꢂ 3.5
85 ꢂ 3.8
90 ꢂ 2.9
A mixture of enaminone 3 (2.66 g, 0.01 mol) and 2-(2,4-
dichlorobenzylidine)malononitrile 4 (2.23 g, 0.01 mol) in ethanol
(20 ml) containing 3 drops of triethy1amine was refluxed for 5 h.
The reaction mixture was filtered while hot and the solid obtained
was crystallized from dioxane to give 6: Yield, 90%; m.p. 291–293 ꢁC;
IR, cmꢀ1: 3464, 3347 (NH2), 3064 (CH arom.), 2957, 2860 (CH
aliph.), 2171 (C^N), 1634 (C]O), 1374, 1189 (SO2), 706 (C–Cl). 1H
5.5
a
Mean of non-viable percentage of three repeated experiments.
b
IC50 value: Corresponds to the compound concentration causing 50% mortality
in net cells.
c
Compounds with IC50 > 100 mg/ml are considered to be inactive.
is more active than the pyrimidoquinoline 15 carrying aromatic 4-
NMR (DMSO-d6) d: 1.8–2.2 [m, 6H, 3CH2], 4.9 [s, 1H, CH], 5.4 [s, 2H,
NH2, D2O-exchangable], 7.1–8.0 [m, 9H, Ar-H þ SO2NH2]. 13C NMR
chlorophenyl moiety at the same position with (IC50 value ¼ 10
mg/
ml).
(DMSO-d6) d: 21.9, 27.8, 34.8, 37.6, 58.6, 113.4, 116.5, 118.3 (C^N),
According to these results it was found that quinoline derivative
10 having 4-chlorophenylthiourea at position-2 with cyano group
128.2, 129.6, 130.9, 131.7, 132.8, 133.6, 136.7, 142.6, 145.9, 155.6,
167.8, 197.5 (C]O). MS, m/z (%): 489 [Mþ] (1.8), 73 (100). Anal.
Calcd. For C22H18Cl2N4O3S: C, 53.99; H, 3.71; N, 11.45. Found: C,
54.33; H, 3.49; N, 11.10.
at position-3 with (IC50 value ¼ 40
mg/ml) is nearly as active as
Doxorubicin as positive control. Finally, compounds 13, 14, 16, 21,
and 18 exhibited a moderate activity, while compounds 7, 8, and 17
showed no activity.
4.1.3. 4-[3-Cyano-4-(2,4-dichlorophenyl)-5-oxo-2-(3-substituted-
thioureido)-5,6,7,8-tetrahydroquinolin-1(4H)-yl]benzene
sulfonamide 7–11
3. Conclusions
A mixture of compound 6 (4.89 g, 0.01 mol) and the corre-
sponding isothiocyanates (0.01 mol) in pyridine (20 ml) was
refluxed for 1 h, the reaction mixture was cooled and then poured
onto cold water, then acidified with dilute HCl. The solid obtained
was crystallized from dioxane to give 7–11, respectively.
We report here the synthesis of some new quinoline and pyr-
imidoquinoline derivatives containing biologically active sulfon-
amide moiety, it was clearly observed that quinolines with either
4-bromobenzenesulfonamide 24 or 4-chlorobenzenesulfonamide
moiety 23 exhibited higher antitumor activity than the reference
drug Doxorubicin. Also, pyrimidoquinoline derivatives 19, 12, 15,
and 20 revealed higher potency than the Doxorubicin. In the
meantime compound 10 is nearly as active as Doxorubicin, while,
compounds 13, 14, 16, 21, and 18 exhibited a moderate activity. On
the other hand compounds 7, 8, and 17 showed no activity.
4.1.3.1. 4-(2-(3-Butylthioureido)-3-cyano-4-(2,4-dichlorophenyl)-5-
oxo-5,6,7,8-tetrahydroquinolin-1(4H)-yl)benzenesulfonamide (7). 7:
Yield, 87%; m.p. 284–286 ꢁC; IR, cmꢀ1: 3432, 3347, 3236 (NH, NH2),
3064 (CH arom.), 2957, 2866 (CH aliph.), 2164 (C^N), 1646 (C]O),
1371, 1191 (SO2), 1256 (C]S), 706 (C–Cl). 1H NMR (DMSO-d6)
d: 0.8
[t, 3H, CH3],1.3–1.8 [m, 6H, 3CH2],1.9–2.4 [m, 6H, 3CH2 cyclo], 5.0 [s,
1H, CH], 7.3–7.9 [m, 9H, Ar-H þ SO2NH2], 8.6 [s, 2H, 2NH, D2O-
exchangable]. MS, m/z (%): 604 [Mþ] (0.62), 42 (100). Anal. Calcd.
For C27H27Cl2N5O3S2: C, 53.64; H, 4.50; N, 11.58. Found: C, 53.46; H,
4.26; N, 11.77.
4. Experimental
4.1. Chemistry
Melting points (ꢁC, uncorrected) were determined in open
capillaries on a Gallenkemp melting point apparatus (Sanyo Gal-
lenkemp, Southborough, UK) and were uncorrected. Precoated
silica gel plates (silica gel 0.25 mm, 60 G F254; Merck, Germany)
were used for thin layer chromatography, dichloromethane/meth-
anol (9.5:0.5) mixture was used as a developing solvent system and
the spots were visualized by ultraviolet light and/or iodine. Infra
red spectra were recorded in KBr discs using IR-470 Shimadzu
spectrometer (Shimadzu, Tokyo, Japan). NMR spectra (in DMSO-d6)
were recorded on Bruker AC-300 Ultra Shield NMR spectrometer
4.1.3.2. 4-(2-(3-Allylthioureido)-3-cyano-4-(2,4-dichlorophenyl)-5-
oxo-5,6,7,8-tetrahydroquinolin-1(4H)-yl)benzenesulfonamide (8). 8:
Yield, 69%; m.p. 169–171 ꢁC; IR, cmꢀ1: 3390, 3346, 3280 (NH, NH2),
3100 (CH arom.), 2950, 2860 (CH aliph.), 2181 (C^N), 1647 (C]O),
1372, 1192 (SO2), 1267 (C]S), 707(C–Cl). 1H NMR (DMSO-d6)
d: 1.2–
2.4 [m, 6H, 3CH2], 3.4 [d, 2H, NCH2, J ¼ 6.5 Hz], 4.3 [d, 2H, CHCH2,
J ¼ 3.5 Hz], 4.9 [s, 1H, CH], 5.4 [s, 1H, C]CH], 7.3–8.0 [m, 9H, Ar-
H þ SO2NH2], 8.3, 9.2 [2s, 2H, 2NH, D2O-exchangable]. MS, m/z (%):
588 [Mþ] (2.1), 45 (100). Anal. Calcd. For C26H23Cl2N5O3S2: C, 53.06;
H, 3.94; N, 11.90. Found: C, 53.31; H, 4.29; N, 11.68.
(Bruker, Flawil, Switzerland,
d ppm) at 300 MHz using TMS as

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4.1.3.3. 4-(2-(3-Phenylthioureido)-3-cyano-4-(2,4-dichlorophenyl)-
5-oxo-5,6,7,8-tetrahydroquinolin-1(4H)-yl)benzenesulfonamide
(9). 9: Yield, 74%; m.p. 165–167 ꢁC; IR, cmꢀ1: 3370, 3345, 3180 (NH,
NH2), 3080 (CH arom.), 2949, 2880 (CH aliph.), 2180 (C^N), 1646
(C]O), 1372, 1192 (SO2), 1269 (C]S), 755 (C–Cl). 1H NMR (DMSO-
NMR (DMSO-d6)
d
: 1.0 [d, 2H, C]CH2, J ¼ 1.9 Hz], 2.1–2.9 [m, 6H,
3CH2 cyclo], 4.5 [s, 1H, CH], 5.1 [d, 2H, NCH2, J ¼ 4.6 Hz], 5.9–6.2 [m,
1H, ]CH], 7.0–7.8 [m, 9H, Ar-H þ SO2NH2], 8.2, 8.3 [2s, 2H, 2NH,
D2O-exchangable]. MS, m/z (%): 703 [Mþ] (4.2), 48 (100). Anal.
Calcd. For C26H23Cl2N5O3S2: C, 53.06; H, 3.94; N, 11.90. Found: C,
53.29; H, 3.73; N, 11.67.
d6)
d: 1.6–2.4 [m, 6H, 3CH2], 5.5 [s, 1H, CH], 7.2–7.8 [m, 14H,
Ar-H þ SO2NH2], 9.0 [s, 2H, 2NH, D2O-exchangable]. 13C NMR
(DMSO-d6)
d: 21.7, 27.6, 35.6, 37.2, 58.0, 112.5, 117.9, 118.5 (C^N),
4.1.4.3. -4-(3-(4-Allyl)-5-(2,4-dichlorophenyl)-4-imino-6-oxo-2-thio
xo-1,2,3,4,6,7,8,9-octahydropyrimido[4,5-b]quinolin-10(5H)-yl)ben-
125.9, 128.1, 129.4, 130.2, 131.3, 132.4, 133.1, 134.6, 137.5, 138.6,
143.0, 145.8, 155.3, 168.7, 179.4 (C]S), 198.9 (C]O). MS, m/z (%):
624 [Mþ] (2.6), 43 (100). Anal. Calcd. For C29H23Cl2N5O3S2: C, 55.77;
H, 3.71; N, 11.21. Found: C, 55.49; H, 3.50; N, 11.45.
zenesulfonamide (14). 14: Yield 83%; m.p. 270–272 ꢁC; IR, cmꢀ1
:
3390, 3325, 3260 (NH, NH2), 3058 (CH arom.), 2926, 2889 (CH
aliph.), 1626 (C]O), 1368, 1191 (SO2), 1295 (C]S), 754 (C–Cl). 1H
NMR (DMSO-d6) d: 1.7–2.6 [m, 6H, 3CH2], 5.5 [s, 1H, CH], 7.1–7.8 [m,
4.1.3.4. 4-(2-(3-(4-Chlorophenylthioureido)-3-cyano-4-(2,4-dichlor-
ophenyl)-5-oxo-5,6,7,8-tetrahydroquinolin-1(4H)-yl))benzenesulfo-
namide (10). 10: Yield, 81%; m.p. ꢁC 152–154 ꢁC; IR, cmꢀ1: 3360,
3316, 3260 (NH, NH2), 3091 (CH arom.), 2950, 2870 (CH aliph.),
2182 (C^N), 1647 (C]O), 1371, 1192 (SO2), 1269 (C]S), 713 (C–Cl).
14H, Ar-H þ SO2NH2], 9.0 [2s, 2H, 2NH, D2O-exchangable]. 13C NMR
(DMSO-d6) d: 21.2, 26.8, 31.6, 37.8, 77.0, 112.6, 116.9 (C^N), 125.9,
126.8, 129.7, 130.4, 131.2, 132.3, 133.5, 134.6, 135.8, 137.5, 143.7,
146.6, 155.6, 169.2, 185.2 (C]S), 199.4 (C]O). MS, m/z (%): 624 [Mþ]
(3.6), 64 (100). Anal. Calcd. For C29H23Cl2N5O3S2: C, 55.77; H, 3.71;
N, 11.21. Found: C, 55.49; H, 3.92; N, 11.52.
1H NMR (DMSO-d6)
d: 1.8–2.4 [m, 6H, 3CH2], 5.4 [s, 1H, CH], 6.9–7.9
[m, 13H, Ar-H þ SO2NH2], 8.0, 9.2 [2s, 2H, 2NH, D2O-exchangable].
MS, m/z (%): 658 [Mþ] (1.4), 43 (100). Anal. Calcd. for
C29H22Cl3N5O3S2: C, 52.85; H, 3.36; N, 10.63. Found: C, 52.61; H,
3.10; N, 10.92.
4.1.4.4. 4-(3-(4-Chlorophenyl)-5-(2,4-dichlorophenyl)-4-imino-6-oxo-
2-thioxo-1,2,3,4,6,7,8,9-octahydropyrimido[4,5-b]quinolin-10(5H)-yl)-
benzene-sulfonamide (15). 15: Yield 86%; m.p. 297–299 ꢁC; IR,
cmꢀ1: 3410, 3391, 3210 (NH, NH2), 3080 (CH arom.), 2940, 2860
(CH aliph.), 1636 (C]O), 1368, 1163 (SO2), 1271 (C]S), 711 (C–Cl).
4.1.3.5. 4-(2-(3-(4-Bromophenylthioureido)-3-cyano-4-(2,4-dichlor-
ophenyl)-5-oxo-5,6,7,8-tetrahydroquinolin-1(4H)-yl))benzenesulfo-
namide (11). 11: Yield, 65%; m.p. 176–178 ꢁC; IR, cmꢀ1: 3390, 3368,
3210 (NH, NH2), 3068 (CH arom.), 2940, 2870 (CH aliph.), 2182
1H NMR (DMSO-d6)
d: 1.6–2.7 [m, 6H, 3CH2], 5.7 [s, 1H, CH], 7.0–
7.7 [m, 13H, Ar-H þ SO2NH2], 8.7, 8.9 [2s, 2H, 2NH, D2O-exchang-
able]. MS, m/z (%): 658 [Mþ] (1.6), 64 (100). Anal. Calcd. For
C29H22Cl3N5O3S2: C, 52.85; H, 3.36; N, 10.63. Found: C, 52.58; H,
3.65; N, 10.41.
(C^N), 1628 (C]O), 1372, 1192 (SO2), 1270 (C]S), 708 (C–Cl). 1
H
NMR (DMSO-d6) d: 1.6–2.3 [m, 6H, 3CH2], 5.3 [s, 1H, CH], 7.4–8.1 [m,
13H, Ar-H þ SO2NH2], 8.6, 9.0 [2s, 2H, 2NH, D2O-exchangable]. MS,
m/z (%): 703 [Mþ] (4.2), 48 (100).Anal. Calcd. For
C29H22BrCl2N5O3S2: C, 49.51; H, 3.15; N, 9.96. Found: C, 49.20; H,
3.48; N, 9.71.
4.1.4.5. -4-(3-(4-Bromophenyl)-5-(2,4-dichlorophenyl)-4-imino-6-ox
o-2-thioxo-1,2,3,4,6,7,8,9-octahydropyrimido[4,5-b]quinolin-10(5H)-
yl)benzene-sulfonamide (16). 16: Yield 82%; m.p. 315–317 ꢁC; IR,
cmꢀ1: 3420, 3385, 3300 (NH, NH2), 3060 (CH arom.), 2925, 2860
(CH aliph.), 1630 (C]O), 1368, 1190 (SO2), 1271 (C]S), 742 (C–Cl).
4.1.4. 4-[5-(2,4-Dichlorophenyl)-4-imino-6-oxo-3-substituted-2-
thioxo-1,2,3,4,6,7,8,9-octahydropyrimido[4,5-b]quinolin-10(5H)-
yl]benzene- sulfonamide 12–16
1H NMR (DMSO-d6)
d: 1.2–2.4 [m, 6H, 3CH2], 5.1 [s, 1H, CH], 6.9–7.8
[m, 13H, Ar-H þ SO2NH2], 8.4, 8.8 [2s, 2H, 2NH, D2O-exchangable].
MS, m/z (%): 703 [Mþ] (1.2), 78 (100). Anal. Calcd. For
C29H22BrCl2N5O3S2: C, 49.51; H, 3.15; N, 9.96. Found: C, 49.26; H,
3.51; N, 9.69.
Method (A): A mixture of compound 6 (4.89 g, 0.01 mol) and the
corresponding isothiocyanate (0.01 mol) in pyridine (20 ml) was
refluxed for 28 h, the reaction mixture was cooled and then poured
onto cold water, then acidified with dilute HCl. The solid obtained
was crystallized from acetic acid to give 12–16, respectively.
Method (B): A solution of compounds 7–11 (0.01 mol) in pyri-
dine (10 ml) was refluxed for 24 h, the reaction mixture was cooled
and then poured onto cold water, then acidified with dilute HCl. The
solid obtained was crystallized from acetic acid to give 12–16,
respectively. (m.p and m.m.p.).
4.1.5. 4-(5-(2,4-dichlorophenyl)-6-oxo-2,4-dithioxo-1,2,3,4,6,7,8,9-
octahydro- pyrimido[4,5-b]quinolin-10(5H)-yl)benzenesulfonamide (17)
A mixture of compound 6 (4.89 g, 0.01 mol) and carbon disulfide
(3 ml) in dry pyridine (10 ml) was refluxed for 48 h. After cooling,
the reaction mixture was poured onto ice-water and acidified with
dilute HCl, the obtained solid was crystallized from ethanol–
dimethylformamide (1:1) to give 17.
4.1.4.1. 4-(3-(4-Butyl)-5-(2,4-dichlorophenyl)-4-imino-6-oxo-2-thio
xo-1,2,3,4,6,7,8,9-octahydropyrimido[4,5-b]quinolin-10(5H)-yl)ben-
17: Yield 62%; m.p. 310–312 ꢁC; IR, cmꢀ1: 3365, 3272, 3205
(NH, NH2), 3098 (CH arom.), 2927, 2880 (CH aliph.), 1653 (C]O),
zenesulfonamide (12). 12: Yield 68%; m.p. 241–243 ꢁC; IR, cmꢀ1
:
1371, 1164 (SO2), 756 (C–Cl). 1H NMR (DMSO-d6)
d
: 1.7–2.6 [m,
6H, 3CH2], 5.6 [s, 1H, CH], 6.8–7.9 [m, 9H, Ar-H þ SO2NH2], 8.8,
9.3 [2s, 2H, 2NH, D2O-exchangable]. 13C NMR (DMSO-d6)
: 20.9,
3380, 3341, 3220 (NH, NH2), 3060 (CH arom.), 2955, 2869 (CH
aliph.), 1627 (C]O), 1368, 1188 (SO2), 1265 (C]S), 763(C–Cl).
d
1H NMR (DMSO-d6)
d
: 1.0 [t, 3H, CH3], 1.2–1.7 [m, 4H, CH2–CH2],
26.8, 36.7, 39.6, 91.0, 112.7, 115.6, 126.7, 128.8, 130.6, 131.5,
132.39, 133.0, 135.8, 142.7, 145.6, 154.2, 162.3, 184.6 (C]S), 196.1
(C]S), 199.7 (C]O). MS, m/z (%): 565 [Mþ] (4.2), 44 (100). Anal.
Calcd. For C23H18Cl2N4O3S3: C, 48.85; H, 3.21; N, 9.91. Found: C,
48.56; H, 3.52; N, 9.61.
1.8–2.4 [m, 6H, 3CH2 cyclo], 4.3 [s, 1H, CH], 5.1 [t, 2H, NCH2], 7.5–8.1
[m, 9H, Ar-H þ SO2NH2], 8.7, 9.0 [2s, 2H, 2NH, D2O-exchangable]. MS,
m/z (%): 703 [Mþ] (4.2), 48 (100). Anal. Calcd. For C27H26Cl2N5O3S2: C,
53.73; H, 4.34; N, 11.60. Found: C, 53.48; H, 4.54; N, 11.87.
4.1.4.2. -4-(3-(4-Allyl)-5-(2,4-dichlorophenyl)-4-imino-6-oxo-2-thio
xo-1,2,3,4,6,7,8,9-octahydropyrimido[4,5-b]quinolin-10(5H)-yl)ben-
4.1.6. 4-[3-Cyano-4-(2,4-dichlorophenyl)-5-oxo-2-ureido-5,6,7,8-
tetrahydro- quinolin-1(4H)-yl]benzenesulfonamide (18)
A mixture of compound 6 (4.89 g, 0.01 mol) and urea (0.9 g,
0.015 mol) in ethanol (20 ml) containing sodium ethoxide (0.5 g)
was refluxed for 4 h., the reaction mixture was cooled acidified
zenesulfonamide (13). 13: Yield 72%; m.p258–260 ꢁC; IR, cmꢀ1
:
3421, 3380, 3200 (NH, NH2), 3068 (CH arom.), 2923, 2866 (CH
aliph.), 1624 (C]O), 1370, 1188 (SO2), 1289 (C]S), 720 (C–Cl). 1H

S.I. Alqasoumi et al. / European Journal of Medicinal Chemistry 45 (2010) 738–744
743
with dilute HCl. The separated crystals were crystallized from
dioxane to give 18.
the formed crystals were collected and crystallized from ethanol/
dimethylformamide (1:1) to give 22: Yield 66%; m.p. 195–197 ꢁC;
IR, cmꢀ1: 3380, 3290 (NH2), 3088 (CH arom.), 2943, 2886 (CH
aliph.), 2213 (C^N), 1783, 1733, 1654 (3C]O), 1368, 1189 (SO2), 760
18: Yield 79%; m.p. 318–320 ꢁC; IR, cmꢀ1: 3366, 3273, 3209 (NH,
NH2), 3105 (CH arom.), 2958, 2866 (CH aliph.), 2170 (C^N), 1696,
1651 (2C]O), 1627 (C]N), 1372, 1185 (SO2), 795 (C–Cl). 1H NMR
(C–Cl). 1H NMR (DMSO-d6)
d: 1.1–1.4 [m, 4H, 2CH2], 1.8–2.7 [m, 6H,
(DMSO-d6)
D2O-exchangable], 7.0–8.0 [m, 9H, Ar-H þ SO2NH2], 9.1 [s, 1H, NH,
D2O-exchangable]. 13C NMR (DMSO-d6)
: 22.0, 27.8, 35.2, 38.4,
d: 1.7–2.9 [m, 6H, 3CH2], 5.4 [s, 1H, CH], 6.8 [s, 2H, NH2,
3CH2 cyclo], 5.3 [s, 1H, CH], 7.2–7.9 [m, 9H, Ar-H þ SO2NH2]. 13C
NMR (DMSO-d6) d: 20.5, 26.6, 28.9, 34.4, 37.1, 60.7, 112.6,115.9, 117.9
d
(C^N), 128.5, 129.3, 131.7, 133.9, 136.3, 143.0, 145.9, 154.5, 155.1,
177.2 (2C]O), 199.4 (C]O). MS, m/z (%): 571 [Mþ] (4.2), 41 (100).
Anal. Calcd. For C26H20Cl2N4O5S: C, 54.65; H, 3.53; N, 9.80. Found: C,
54.41; H, 3.84; N, 9.65.
61.5, 113.6, 115.9, 117.6 (C^N), 126.6, 128.7, 130.4, 131.5, 133.7, 136.7,
142.7, 145.4, 150.6, 155.0, 156.3, 198.4 (C]O). MS, m/z (%): 532 [Mþ]
(2.8), 48 (100). Anal. Calcd. For C23H19Cl2N5O4S: C, 51.89; H, 3.60; N,
13.15. Found: C, 52.08; H, 3.77; N, 12.85.
4.1.10. 4-Nitro-N-(3-cyano-4-(2,4-dichlorophenyl)-5-oxo-1-(4-
sulfamoyl phenyl)-1,4,5,6,7,8-hexahydroquinolin-2-
yl)benzenesulfonamide (23), 4-bromo-N-(3-cyano-4-(2,4-
dichlorophenyl)-5-oxo-1-(4-sulfamoyl phenyl)-1,4,5,6,7,8-
hexahydroquinolin-2-yl) benzenesulfonamide (24)
4.1.7. 4-[4-Amino-5-(2,4-dichlorophenyl)-2,6-dioxo-1,2,6,7,8,9-
hexahydro-pyrimido[4,5-b]quinolin-10(5H)-yl]benzenesulfonamide
(19) and 4-[4-amino-5-(2,4-dichlorophenyl)-6-oxo-2-thioxo-
1,2,6,7,8,9-hexahydro-pyrimido[4,5-b]quinolin-10(5H)-
yl]benzenesulfonamide (20)
A mixture of compound 6 (4.89 g, 0.01 mol) and 4-nitro or
4-bromo-benzenesulfonylchloride (0.01 mol) in dry pyridine
(10 ml) was refluxed for 8 h, the reaction mixture was cooled and
poured onto ice-water, then acidified with dilute HCl, the obtained
solid was crystallized from dioxane to give 23 and 24, respectively.
23: Yield 89%; m.p. 177–179 ꢁC; IR, cmꢀ1: 3370, 3351, 3260 (NH,
NH2), 3093 (CH arom.), 2940, 2886 (CH aliph.), 2180 (C^N), 1647
A mixture of compound 6 (4.89 g, 0.01 mol) and urea or thiourea
(0.015 mol) was fused together at 250 ꢁC for 15 min, the formed
mass was then triturated with ethanol and the separated solid was
crystallized from ethanol–dimethylformamide (1:1) to give 19 and
20, respectively.
19: Yield 65%; m.p. 252–254 ꢁC; IR, cmꢀ1: 3320, 3209, 3190 (NH,
NH2), 3084 (CH arom.), 2920, 2830 (CH aliph.), 1700, 1630 (2C]O),
(C]O), 1372, 1192 (SO2), 742 (C–Cl). 1H NMR (DMSO-d6)
d: 1.7–2.9
1399, 1157 (SO2), 789 (C–Cl). 1H NMR (DMSO-d6)
d: 1.6–2.9 [m, 6H,
[m, 6H, 3CH2], 5.6 [s, 1H, CH], 7.3–8.2 [m, 13H, Ar-H þ SO2NH2], 8.3
[s, 1H, NH, D2O-exchangable]. MS, m/z (%): 674 [Mþ] (1.6), 40 (100).
Anal. Calcd. For C28H21Cl2N5O7S2: C, 49.86; H, 3.14; N, 10.38. Found:
C, 49.52; H, 3.47; N, 10.61.
3CH2], 5.2 [s, 1H, CH], 6.9 [s, 2H, NH2, D2O-exchangable], 7.2–8.1 [m,
9H, Ar-H þ SO2NH2], 8.9 [s, 1H, NH, D2O-exchangable]. 13C NMR
(DMSO-d6) d: 20.0, 26.1, 30.4, 37.1, 78.1, 112.6, 114.2, 126.5, 129.3,
130.4, 131.7, 133.0, 134.5, 136.8, 142.6, 143.2, 145.6, 154.8, 163.1,
165.4, 197.4 (C]O). MS, m/z (%): 532 [Mþ] (2.5), 41 (100). Anal.
Calcd. For C23H19Cl2N5O4S: C, 51.89; H, 3.60; N, 13.15. Found: C,
52.16; H, 3.90; N, 13.34.
24: Yield 87%; m.p. 308–310 ꢁC; IR, cmꢀ1: 3390, 3349, 3210 (NH,
NH2), 3089 (CH arom.), 2952, 2860 (CH aliph.), 2182 (C^N), 1647
(C]O), 1372, 1192 (SO2), 708 (C–Cl). 1H NMR (DMSO-d6)
d: 1.6–2.6
[m, 6H, 3CH2], 5.2 [s, 1H, CH], 6.9–7.8 [m, 13H, Ar-H þ SO2NH2], 8.6
[s, 1H, NH, D2O-exchangable]. MS, m/z (%): 708 [Mþ] (3.1), 44 (100).
Anal. Calcd. For C28H21BrCl2N4O5S2: C, 47.47; H, 2.99; N, 7.91. Found:
C, 47.71; H, 2.69; N, 7.73.
20: Yield 67%; m.p. >320 ꢁC; IR, cmꢀ1: 3420, 3380, 3310 (NH,
NH2), 2950, 2882 (CH aliph.), 1653 (C]O), 1636 (C]N), 1390, 1160
(SO2), 750 (C–Cl). 1H NMR (DMSO-d6)
d: 1.4–2.6 [m, 6H, 3CH2], 5.7
[s, 1H, CH], 6.7 [s, 2H, NH2, D2O-exchangable], 7.2–8.1 [m, 9H, Ar-
H þ SO2NH2], 9.4 [s, 1H, NH, D2O-exchangable]. MS, m/z (%): 548
[Mþ] (2.4), 47 (100). Anal. Calcd. For C23H19Cl2N5O3S2: C, 50.37; H,
3.49; N, 12.77. Found: C, 50.63; H, 3.78; N, 12.49.
4.2. Biological testing
4.2.1. Animals, chemicals and facilities
Ehrlich Ascites Carcinoma cells (EAC) was maintained in female
Swiss albino mice weighing 25–30 g (the holding company for
biological products and vaccines, VACSERA, Cairo, Egypt) were
housed at a constant temperature (24 ꢂ 2 ꢁC) with alternating 12-h
light and dark cycles and fed standard laboratory food (Milad CO.,
Cairo, Egypt) and water ad libitum. All chemicals and reagents were
of the highest grade commercially available. Facilities including
animal house, biochemical equipments have been made available
by the National Center for Radiation Research and Technology
(NCRRT), Atomic Energy Authority (AEA), Cairo, Egypt. Animal care
and handling was done according to the guidelines set by the world
health organization, Geneva, Switzerland and approved from the
committee for animals care at NCRRT, AEA.
4.1.8. 4-[3-Cyano-4-(2,4-dichlorophenyl)-5-oxo-1-(4-sulfamoyl-
phenyl)-1,4,5,6,7,8-hexahydroquinolin-2-ylamino]-4-oxobutanoic
acid (21)
A mixture of compound 6 (4.89 g, 0.01 mol) and succinic
anhydride (1.5 g 0.015 mol) in ethanol (30 ml) was refluxed for 6 h,
the reaction mixture was concentrated and the solid obtained was
crystallized from dioxane to give 21: Yield 77%; m.p. 302–304 ꢁC;
IR, cmꢀ1: 3463 (OH), 3347, 3310, 3230 (NH, NH2), 3064 (CH arom.),
2940, 2866 (CH aliph.), 2171 (C^N), 1650, 1634 (3C]O), 1374, 1189
(SO2), 706 (C–Cl). 1H NMR (DMSO-d6)
d: 1.1–1.2 [m, 4H, CH2CH2],
1.4–2.7 [m, 6H, 3CH2 cyclo], 5.0 [s, 1H, CH], 7.3–7.9 [m, 9H, Ar-
H þ SO2NH2], 8.0 [s, 1H, NH, D2O-exchangable], 8.9 [s, 1H, OH, D2O-
exchangable]. 13C NMR (DMSO-d6)
d: 21.5, 27.6, 32.4, 33.1, 34.5, 37.6,
60.8, 111.6, 115.5, 117.9 (C^N), 127.5, 129.3, 130.5, 131.6, 133.2, 134.3,
136.9, 142.4, 145.2, 154.9, 157.0, 171.6 (C]O), 178.0 (C]O), 199.5
(C]O). Anal. Calcd. For C26H22Cl2N4O6S: C, 52.98; H, 3.76; N, 9.50.
Found: C, 52.69; H, 3.47; N, 9.77.
4.2.2. Antitumor activity [31]
Ehrlich Ascites Carcinoma cells (EAC) were obtained by needle
aspiration of ascetic fluid from preinoculated mice; under aseptic
conditions. Tumor cells suspension (2.5 ꢃ106 per ml) was prepared
in RPMI-1640 media. Tested compounds were prepared with
4.1.9. 4-[3-Cyano-4-(2,4-dichlorophenyl)-2-(2,5-dioxopyrrolidin-1-
yl)-5-oxo-5,6,7,8-tetrahydroquinolin-1(4H)-yl]benzene-
sulfonamide (22)
A mixture of compound 6 (4.89 g, 0.01 mol) and succinic
anhydride (1.5 g, 0.015 mol) was fused together in an oil bath at
250 ꢁC for 20 min, the fused mass was triturated with ethanol and
various dilutions by dissolving: 100, 50, 25 & 10
compounds in DMSO (1 ml).
In a set of sterile test tubes 0.8 ml RPMI-1640 media containing
(glutamine, fetal calf serum as nutrient, streptomycin and peni-
cillin), 0.1 ml of each of the tested compounds (corresponding to
mg of the tested
100, 50, 25, 10 mg) were mixed then 0.1 ml of tumor cell suspension

744
S.I. Alqasoumi et al. / European Journal of Medicinal Chemistry 45 (2010) 738–744
(2 ꢃ106) was added. The test tubes were incubated at 37 ꢁC for 2 h.
Trypan blue exclusion test was carried out to calculate the
percentage of non-viable cells after 2 h of incubation [32].
The total number of cells/ml will be determined using the
following calculations:
[9] C.H. Tseng, Y.L. Chen, P.J. Lu, C.N. Yang, C.C. Tzeng, Bioorg. Med. Chem. 16 (6)
(2008) 3153–3162.
[10] Y.L. Chen, I.L. Chen, T.C. Wang, C.H. Han, C.C. Tzeng, Eur. J. Med. Chem. 40
(2005) 928–934.
[11] M.M. Ghorab, E. Noaman, M.M.F. Ismail, H.I. Heiba, Y.A. Amar, M.Y. Sayed,
Arzneimittelforschung 56 (6) (2006) 405–413.
[12] M.M. Ghorab, F.A. Ragab, E. Noaman, H.I. Heiba, M. Galal, Arzneimittelfor-
schung 56 (7) (2006) 553–560.
[13] D.A. Abou El Ella, M.M. Ghorab, E. Noaman, H.I. Heiba, A.I. Khalil, Bioorg. Med.
Chem. 16 (5) (2008) 2391–2402.
[14] M.M. Ghorab, A.N. Osman, E. Noaman, H.I. Heiba, N.H. Zaher, Phosphorus,
Sulfur, Silicon 181 (2006) 1935–1950.
Cells=ml [ average cells count per 5 squares 3 dilution
factor 3 104:
[15] M.M. Ghorab, A.N. Osman, E. Noaman, H.I. Heiba, N.H. Zaher, Phosphorus,
Sulfur, Silicon 181 (2006) 1983–1996.
[16] H.I. Heiba, F.A. Ragab, E. Noaman, M.M. Ghorab, M. Galal, Arzneimittelfor-
schung 56 (8) (2006) 593–599.
Total cells [ cells=ml 3 the original volume of fluid from
which thecellsample was removed:
[17] M.M. Ghorab, Phosphorus, Sulfur, Silicon 165 (2000) 221–235.
[18] M.M. Ghorab, S.B. El-Sayed, H.M. Saker, M.M. Abd Rabo, Arzneimittelforschung
56 (9) (2006) 665–670.
[19] M.M. Ghorab, S.G. Abdel-Hamide, M.M. Abou Zeid, Phosphorus, Sulfur, Silicon
112 (1996) 7–17.
[20] M.M. Ghorab, S.G. Abdel-Hamide, M.S.A. El-Gaby, Acta Pharm. 49 (1999) 1–10.
[21] M.M. Ghorab, Z.H. Ismail, S.M. Abdel-Gawad, A. Abdel-Aziem, Heteroat. Chem.
15 (2004) 57–62.
total non-viable cells ðstainedÞ
% cell non-viability ¼
ꢃ 100
total cells
The results of in-vitro cytotoxic activity experiments are pre-
sented in Table 1.
[22] S.A. Rostom, Bioorg. Med. Chem. 14 (19) (2006) 6475–6485.
[23] C.T. Supuran, A. Casini, A. Mastrolorenzo, A. Scozzafava, Mini-Rev. Med. Chem.
4 (6) (2004) 625–632.
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