Copper(II) and uranyl(II) complexes with acylthiosemicarbazide: Synthesis, characterization, antibacterial activity and effects on the growth of promyelocytic leukemia cells HL-60

Article abstract of DOI:10.1016/j.ejmech.2009.03.016

New chelates of N¹-[4-(4-X-phenylsulfonyl)benzoyl]-N⁴-butyl-thiosemicarbazide (X = H, Cl, Br) with Cu²⁺ and UO₂²⁺ have been prepared and characterized by analytical and physico-chemical techniques such as magnetic susceptibility measurements, elemental and thermal analyses, electronic, ESR and IR spectral studies. Room temperature ESR spectra of Cu(II) complexes yield {g} values characteristic of distorted octahedral and pseudo-tetrahedral geometry. Infrared spectra indicate that complexes contain six-coordinate uranium atom with the ligand atoms arranged in an equatorial plane around the linear uranyl group. Effects of these complexes on the growth of human promyelocytic leukemia cells HL-60 and their antibacterial activity (against Staphylococcus epidermidis ATCC 14990, Bacillus subtilis ATCC 6633, Bacillus cereus ATCC 14579, Pseudomonas aeruginosa ATCC 9027 and Escherichia coli ATCC 11775 strains) were studied comparatively with that of free ligands.

Full text of DOI:10.1016/j.ejmech.2009.03.016

European Journal of Medicinal Chemistry 44 (2009) 3323–3329
Contents lists available at ScienceDirect
European Journal of Medicinal Chemistry
journal homepage: http://www.elsevier.com/locate/ejmech
Short communication
Copper(II) and uranyl(II) complexes with acylthiosemicarbazide: Synthesis,
characterization, antibacterial activity and effects on the growth
of promyelocytic leukemia cells HL-60
,
a
a
Madalina Veronica Angelusiu a, Gabriela Laura Almajan b , Tudor Rosu , Maria Negoiu ,
*
Eva-Ruxandra Almajan c, Jenny Roy d
a University of Bucharest, Faculty of Chemistry, Inorganic Chemistry Department, 23 Dumbrava Rosie Street, 020462 Bucharest, Romania
b University of Medicine and Pharmacy, Faculty of Pharmacy, Organic Chemistry Department, 6 Traian Vuia Street, 020956 Bucharest, Romania
c Horia Hulubei National Institute of Physics and Nuclear Engineering IRASM, Radiation Processing Center, Microbiological Laboratory, 407 Atomistilor Street, P.O. Box MG-6,
Bucharest-Magurele, Romania
d
´
´
Oncology and Molecular Endocrinology Research Center, CHUL Research Center and Universite Laval, CHUQ-CHUL, 2705 Boulevard Laurier, Quebec City, G1V4G2 Canada
a r t i c l e i n f o
a b s t r a c t
New chelates of N1-[4-(4-X-phenylsulfonyl)benzoyl]-N4-butyl-thiosemicarbazide (X ¼ H, Cl, Br) with
Cu2þ and UO22þ have been prepared and characterized by analytical and physico-chemical techniques
such as magnetic susceptibility measurements, elemental and thermal analyses, electronic, ESR and IR
spectral studies. Room temperature ESR spectra of Cu(II) complexes yield {g} values characteristic of
distorted octahedral and pseudo-tetrahedral geometry. Infrared spectra indicate that complexes contain
six-coordinate uranium atom with the ligand atoms arranged in an equatorial plane around the linear
uranyl group. Effects of these complexes on the growth of human promyelocytic leukemia cells HL-60
and their antibacterial activity (against Staphylococcus epidermidis ATCC 14990, Bacillus subtilis ATCC
6633, Bacillus cereus ATCC 14579, Pseudomonas aeruginosa ATCC 9027 and Escherichia coli ATCC 11775
strains) were studied comparatively with that of free ligands.
Article history:
Received 24 October 2008
Received in revised form
15 February 2009
Accepted 12 March 2009
Available online 24 March 2009
Keywords:
Acylthiosemicarbazide
Cu(II) complexes
UO2(II) complexes
HL-60 cells
Ó 2009 Elsevier Masson SAS. All rights reserved.
Antibacterial activity
1. Introduction
(Fig. 2) and we described a preliminary investigation of their
structure and biological activity.
Complexes of thiosemicarbazide and 1,4-substituted thio-
semicarbazide are of general interest as models for bioinorganic
processes [1–3]. Numerous transition metal complexes of
substituted thiosemicarbazides, particularly the 1,4-substituted
derivatives, have been prepared and characterized and they have
been found to possess a wide variety of biological activities against
bacteria, fungi and certain type of tumours [4–10]. Acylth-
iosemicarbazide contains oxygen, sulphur and nitrogen as potential
donor atoms and is liable to form deprotonated complexes by loss
of hydrazinic proton via enolisation/thioenolisation, because it
might present a lot of tautomeric forms (Fig. 1).
2. Chemistry
The ligands N1-[4-(4-X-phenylsulfonyl)benzoyl]-N4-butyl-thio-
semicarbazide, X ¼ H, Cl, Br were obtained earlier [11] according to
Scheme 1.
For the synthesis of complexes were used Cu(II) chloride, nitrate,
acetate and thiocyanate salts and UO2(II) acetate, respectively,
which were refluxed with stirring with a hot clear solution of the
ligand in ethanol (1:1 metal:ligand ratio).
Keeping this observation in view, in this paper we have
synthesized new complexes of Cu(II) and UO2(II) with N1-[4-(4-
X-phenylsulfonyl)benzoyl]-N4-butyl-thiosemicarbazide as ligand
3. Biological activity
3.1. Antibacterial activity
The synthesized compounds were tested for their in vitro anti-
bacterial activity against the Gram-positive and the Gram-negative
bacteria: Staphylococcus epidermidis ATCC 14990, Bacillus subtilis
ATCC 6633, Bacillus cereus ATCC 14579, Pseudomonas aeruginosa
* Corresponding author. Tel.: þ40 741 095490; fax: þ40 21 3180729.
E-mail address: laura.almajan@gmail.com (G.L. Almajan).
0223-5234/$ – see front matter Ó 2009 Elsevier Masson SAS. All rights reserved.
doi:10.1016/j.ejmech.2009.03.016

3324
M.V. Angelusiu et al. / European Journal of Medicinal Chemistry 44 (2009) 3323–3329
OH
C
S
H
N
2
H
N
4
enol / thione form
N
1
C
3
O
C
S
H
N
H
N
H
N
C
3
SH
O
C
1
2
4
H
N
1
H
N
4
keto / thiol form
N
2
C
3
keto / thione form
Fig. 1. Tautomeric forms for N1-acyl-N4-substituted thiosemicarbazide.
spectrum of the free ligand was compared with the spectra of the
complexes.
All the ligands having three vibrational frequency from 3425 to
3178 cmꢀ1 which are assigned to the stretching vibration of the NH
groups, a strong band at the regions of 1679–1672 cmꢀ1 corre-
S
O
S
HL1 : X=H
HL2 : X=Cl
H
N
1
H
N
2
H
N
4
X
C
O
C
3
CH2CH2CH2CH3
HL3 : X=B
r
O
Fig. 2. Structure of the ligands.
sponding to
In all IR spectra of complexes the
observed, but the presence of a new band at 1578–1559 cmꢀ1, due
to the
(N]C) of N]C–Oꢀ group, indicates the enolisation of C]O
n(C]O) stretching vibration [11,16].
n(C]O) mode of ligand is not
ATCC 9027 and Escherichia. coli ATCC 11775, comparative with free
ligands, using the paper disc diffusion method [12] (for the quali-
tative determination) and the serial dilutions in liquid broth
method [13] for determination of MIC. Chloramphenicol was used
as control drug.
n
group followed by deprotonation and complexation with metal
ions. This is further supported by the presence of band at 1246–
1242 cmꢀ1 corresponding to C]S stretching vibrations in free
ligands which have not presented considerable change in the
complexes and ruling out the possibility of bonding through the
pC]S group. Furthermore, the Cu(II) complexes show extra IR
bands in the 532–427 cmꢀ1 and 477–412 cmꢀ1 regions assigned to
3.2. Antitumor activity
The biochemical effects involved in the antitumor activity of
ligands and some of newly synthesized complexes in human HL-60
promyelocytic leukemia cells were investigated using 3-(4,5-
dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfo-
phenyl)-2H-tetrazolium, inner salt (MTS), which is converted to
blue formazan by an enzyme present in metabolically active cells.
This product can be completely solubilized in acidified isopropanol
and detected by a microtiter plate reader [14].
n(M–O) and
n(M–N), respectively [17,18].
The complex combinations 1a, 1b, 5a, 5b, 9a, 9b obtained using
CuCl2 and Cu(NO3)2 exhibit y(OH) and r(H2O) bands in the 3400–
3420 and 680–690 cmꢀ1 regions which are indicative of coordi-
nated water in the complexes [19,20].
The presence of n
(CH3COO) absorption bands at 1534 cmꢀ1 and
1422 cmꢀ1 in the IR spectra of complexes 2, 6 and 10 suggests that
the acetate group is coordinated to Cu(II) ion in ring bridge, in
a bidentate form [17]. In the IR spectrum of 3, 7 and 11 (prepared
from CuSCN), two absorption bands in the region 684–670 cmꢀ1
and 443–430 cmꢀ1, respectively, specific to the S-coordinated
thiocyanate group are detected [17]. No absorption is noted in the
870–780 cmꢀ1 range, so the N-coordination of the thiocyanate is
ruled out.
4. Results and discussions
4.1. Chemistry
The elemental analysis data along with some physical properties
of the complexes are reported in Table 1. The composition and
molecular formulas of the complexes under investigation were
further confirmed from the values of molar conductance. The molar
conductances in DMSO are in 2.5–8.6 ohmꢀ1 cm2 molꢀ1 range. The
data suggests that the complexes behave as nonelectrolytes [15].
In the uranyl complexes 4, 8 and 12, the bands which are
observed near 1530 and 1435 cmꢀ1 attributed to nas(OCO) and
ns(OCO) of the acetate group, respectively, indicate asymmetric
bidentate
coordination
of
this
group
(
D
(OCO) ¼
nas(OCO) ꢀ ns(OCO) < 100 cmꢀ1) [17]. Also, the uranyl complexes
show strong IR band near 839 cmꢀ1 assigned to nas(UO2) [21–23].
The overall IR spectral data suggests that the thiosemicarbazide
derivatives act as mononegative bidentate ligands and coordinate
4.1.1. IR spectra
Relevant IR data is given in Table 2. In order to study the binding
mode of thiosemicarbazides to the metal ion complexes, the IR
O
O
+ CH3C6H4SO2Cl
CrO3
X
X
S
CH3
X
S
COOH
AlCl3
AcOH
O
O
O
S
HN NH
O
S
O
1) EtOH
+ nC4H9NCS
H
X
C
X
C
O
C
S
N
C4H9(n)
EtOH
NHNH2
2) N2H4 100%
O
O
HL1 : X=H
HL2 : X=Cl
HL3 : X=Br
Scheme 1. Synthesis of the ligands.

M.V. Angelusiu et al. / European Journal of Medicinal Chemistry 44 (2009) 3323–3329
3325
(BM)
Table 1
Analytical data and physical properties of N1-[4-(4-X-phenylsulfonyl)benzoyl]-N4-butyl-thiosemicarbazide (X ¼ H, Cl, Br) complexes.
Compd. Molecular formula
MW (%) Colour
Yield Elemental analysis (%) calcd. (found)
L
(ohmꢀ1 cm2 molꢀ1
)
m
C
N
M
1a
1b
2
3
4
5a
5b
6
7
8
9a
9b
10
11
12
[Cu(L1)2(H2O)2] (C36H44CuN6O8S4)
880.57 Green
880.57 Green
1098.24 Dark green 75
530.14 Green
719.57 Dark red
949.46 Green
949.46 Green
82
68
49.10 (49.02)
49.10 (49.00)
43.75 (43.70)
9.54 (9.47)
9.54 (9.43)
7.65 (7.59)
7.22 (7.15)
7.22 (7.23)
11.57 (11.65) 4.7
5.3
6.1
2.15
2.25
1.25
1.75
1.50
2.20
2.23
1.34
1.80
1.50
2.18
2.22
1.50
1.75
1.70
[Cu(L1)2(H2O)2] (C36H44CuN6O8S4)
[Cu2(L1)2(AcO)2(H2O)4] (C40H54Cu2N6O14S4)
[Cu(L1)(SCN)(H2O)] (C19H22CuN4O4S3)
[UO2(L1)(AcO)] (C20H23N4O7S2U)
83
79
69
71
43.05 (42.98) 10.57 (10.50) 11.99 (12.01) 2.5
33.38 (33.31)
45.54 (45.48)
45.54 (45.50)
41.16 (41.08)
40.42 (40.43)
31.86 (31.78)
41.64 (41.58)
41.64 (41.60)
38.25 (38.17)
37.47 (37.42)
30.08 (30.02)
5.84 (5.78)
8.85 (8.79)
8.85 (8.81)
7.20 (7.15)
9.92 (10.01)
5.57 (5.46)
8.09 (8.02)
8.09 (8.05)
6.69 (6.61)
9.20 (9.23)
5.26 (5.30)
33.08 (33.22) 8.6
6.69 (6.73)
6.69 (6.61)
10.89 (10.96) 4.1
11.26 (11.35) 3.6
31.57 (31.48) 5.2
6.12 (6.19)
6.12 (6.18)
[Cu(L2)2(H2O)2] (C36H42Cl2CuN6O8S4)
[Cu(L2)2(H2O)2] (C36H44CuN6O8S4)
7.5
6.5
[Cu2(L2)2(AcO)2(H2O)4] (C40H52Cl2Cu2N6O14S4)
[Cu(L2)(SCN)(H2O)] (C19H21ClCuN4O4S3)
[UO2(L2)(AcO)] (C20H22ClN4O7S2U)
[Cu(L3)2(H2O)2] (C36H42Br2CuN6O8S4)
[Cu(L3)2(H2O)2] (C36H42Br2CuN6O8S4)
1167.13
Dark green 80
564.58 Green
754.02 Dark red
1038.36 Green
1038.36 Green
78
65
78
81
2.8
3.7
4.0
[Cu2(L3)2(AcO)2(H2O)4] (C40H52Br2Cu2N6O14S4) 1256.03 Dark green 82
10.12 (10.18)
10.43 (10.50) 3.2
29.81 (29.88) 4.4
[Cu(L3)(SCN)(H2O)] (C19H21BrCuN4O4S3)
[UO2(L3)(AcO)] (C20H22BrN4O7S2U)
609.04 Green
798.46 Dark red
68
75
through deprotonated enolic carbonyl oxygen (]C–Oꢀ) and
hydrazinic N2H nitrogen atoms and form a five-membered chelate
ring.
indicative of one unpaired electron per Cu(II) ion. The UV–VIS
spectra for these complexes (Table 3) shows d–d bands in the
regions 13,003–12,345, 14,970–14,045 and 16,325–15,822 cmꢀ1
which may be assigned to dx2ꢀy2 /dz2 ; dx2ꢀy2 /dxy
;
and
4.1.2. Electronic spectra and magnetic studies
dx2ꢀy2 /dxz;yz transitions, respectively, due to the distorted octa-
hedral geometry (D4h) around Cu(II) [24].
The nature of the ligand field around metal ion and the geom-
etry of the metal complexes have been deduced from the electronic
spectra and magnetic moment data of the complexes. The room
temperature magnetic moment (Table 1) of the Cu(II) complexes
1a, 1b, 5a, 5b, 9a and 9b was found in the range 2.15–2.25 BM,
The electronic spectra for 2, 6 and 10 exhibit three bands
observed at 12,562–12,484 cmꢀ1, 14,447–14,347 cmꢀ1 and 16,835–
16,121 cmꢀ1 which may be assigned to dx2ꢀy2 /dz2 ; , dx2ꢀy2 /dxy
;
and dx2ꢀy2 /dxz;yz; transitions, respectively, due to the octahedral
Table 2
IR bands and their assignments for N1-[4-(4-X-phenylsulfonyl)benzoyl]-N4-butyl-thiosemicarbazide and its complexes 1–12.
as;s
SO2
as,s
Compd.
HL1
yN4
yN2
yN1
H
yC]O
yC]N
yC]S
yN1
y
y
yC–X (X ¼ Cl, Br)
–
yM–O, yM–N [17]
ꢀN2
acetate
H
H
3425
3287
3267
3290
3282
3332
3420
3284
3253
3286
3278
3336
3420
3283
3256
3291
3239
3336
3290
3108
3103
3110
3104
3243
3340
3104
3141
3158
3242
3242
3341
3154
3143
3175
3141
3244
3196
1672
–
1242
1010
1015
1015
1012
1020
1016
1010
1013
1013
1013
1014
1014
1011
1011
1010
1010
1010
1011
–
–
–
1324
1159
1326
1160
1324
1160
1331
1160
1323
1154
1327
1157
1326
1160
1335
1161
1331
1162
1330
1160
1329
1157
1335
1162
1324
1160
1331
1160
1330
1161
1331
1160
1326
1156
1333
1162
–
1a
1b
2
–
–
1561
1559
1562
1564
1577
–
1238
1236
1238
1240
1238
1242
1243
1240
1240
1240
1230
1246
1243
1243
1243
1245
1239
–
–
–
–
–
532
419
531
419
520
428
518
423
839
–
–
–
–
1534
1421
–
3
–
–
4
–
–
1531
1436
–
(Uranyl abs.)
–
HL2
5a
5b
6
3188
1672
635
580
623
577
622
581
623
577
624
570
626
581
616
575
615
576
614
577
617
574
616
574
617
575
–
–
1560
1576
1561
1565
1578
–
–
–
525
473
528
477
527
473
529
471
–
–
–
–
1534
1421
–
7
–
–
8
–
–
1529
1435
–
838
(Uranyl abs.)
-
HL3
9a
9b
10
11
12
3178
1679
–
–
-
–
–
-
1570
1574
1569
1577
1575
–
–
434
417
438
413
430
418
427
412
1534
1422
–
–
–
–
–
1528
1435
839
(Uranyl abs.)

3326
M.V. Angelusiu et al. / European Journal of Medicinal Chemistry 44 (2009) 3323–3329
Table 3
the ligand to the uranyl ion, which is imparting the complex its red
colour [24].
Electronic spectra (cmꢀ1) for the Cu(II) complexes.
Compound
Band max (cmꢀ1
)
Transitions
Geometry
4.1.3. ESR spectra
The tensor value {g} of copper complexes (Table 5) can be used
to derive the ground state.
The shape of ESR spectra for (1a, b), (5a, b) and (9a, b) is very
similar, leading to close values of the {g} tensor, which are specific
to an octahedral geometry of the Cu(II) ion. The parameter
1a
38,023; 29,940; 27,397
24,691
16,325
14,970
37,987; 29,914; 27,365
24,687
14,903
12,345
38,103; 29,967; 27,485
24,691
16,121
Intraligand
Charge transfer
Distorted
Octahedral (D4h
)
)
)
dx2 /dxz;yz
ꢀy2
dx2 /dxy
ꢀy2
1b
2
Intraligand
Distorted
Octahedral (D4h
Charge transfer
dx2 /dxy
ꢀy2
dx2 /dz2
ꢀy2
G ¼ (g ꢀ 2)/(gt ꢀ 2) < 4 (G value is in 1.90–2.94 range) indicates an
k
Intraligand
Distorted
Octahedral (D4h
exchange interaction between the Cu(II) ions and further supports
the dinuclear nature of the complexes [25–27].
Charge transfer
dx2 /dxz;yz
ꢀy2
The room temperature ESR spectra of Cu(II) complexes obtained
with Cu(CH3COO)2 exhibit an isotropic signal, with giso ¼ 2.089 (2);
2.086 (6) and 2.090 (10), which confirms the octahedral geometry
for metallic ion [28,29]. In pseudo-tetrahedral complexes (3), (7)
and (11) the unpaired electron lies in the dxy orbital giving 2B1 as
the ground state. The g values obtained in case of these complexes
indicate an increase of the covalent nature of the bonding between
the metal ion and the ligand molecule. The ESR parameters of the
complexes coincide well with related systems which suggests that
the complex has pseudo-tetrahedral geometry [24,30].
14,347
12,484
dx2 /dxy
ꢀy2
dx2 /dz2
ꢀy2
3
37,287; 30,094
24,154; 20,375
14,026
38,561; 29,787; 27,302
23,981
15,822
14,388
12,391
38,260; 29,568; 27,300
23,484
15,873
14,814
38,602; 29,805; 27,326
22,870
16,187
Intraligand
Pseudo-
Tetrahedral
Charge transfer
d
xy/dz2 ; dx2ꢀy2
5a
Intraligand
Distorted
Octahedral (D4h
Charge transfer
)
dx2 /dxz;yz
ꢀy2
dx2 /dxy
ꢀy2
dx2 /dz2
ꢀy2
5b
6
Intraligand
Distorted
Octahedral (D4h
Charge transfer
)
)
dx2 /dxz;yz
ꢀy2
dx2 /dxy
ꢀy2
4.1.4. Thermogravimetric analysis
Intraligand
Distorted
Octahedral (D4h
The TG thermograms of complexes are characterized by three or
four degradation steps, the first and/or the second weight loss
endothermic step corresponds to the release of the coordinated
small fragments (H2O, SCN). Always, the ligand supports two
stepwise decomposition between 275–480 ꢁC (w60% ligand loss)
and 500–680 ꢁC (w40% ligand loss). For the complexes 2, 4, 6, 8, 10,
12 the last step of decomposition is attributed to the removal of the
acetate species. Up to 700 ꢁC, the final residue (CuO, UO3) is formed.
Thus, based on these analytical and physico-chemical data, the
proposed structures for the complexes are shown in Fig. 3.
Charge transfer
dx2 /dxz;yz
ꢀy2
14,447
12,562
dx2 /dxy
ꢀy2
dx2 /dz2
ꢀy2
7
37,814; 30,101
24,205; 20,526
13,880
30,087; 29,714; 25,009
21,682
16,103
14,045
30,015; 29,684; 24,999
21,240
Intraligand
Pseudo-
Tetrahedral
Charge transfer
d
xy/dz2 ; dx2ꢀy2
9a
Intraligand
Distorted
Octahedral (D4h
Charge transfer
)
)
dx2 /dxz;yz
ꢀy2
dx2 /dxy
ꢀy2
9b
Intraligand
Distorted
Octahedral (D4h
Charge transfer
15,873
14,326
13,003
30,114; 29,812; 25,126
20,214
dx2 /dxz;yz
ꢀy2
4.2. Biological activity
dx2 /dxy
ꢀy2
dx2 /dz2
ꢀy2
4.2.1. Antibacterial activity
10
11
Intraligand
Distorted
Octahedral (D4h
Charge transfer
)
The free ligands and their metal complexes were screened for
their antibacterial activities. The results (Table 6) indicated that
the ligands do not have any significant activity, whereas their
complexes showed more activity against the some organisms
under identical experimental conditions. This would suggest that
the chelation could facilitate the ability of a complex to cross
a cell membrane and can be explained by Tweedy’s chelation
theory [31]. Chelation considerably reduces the polarity of the
metal ion mainly because of partial sharing of its positive charge
with the donor group and possible electron delocalization over
the whole chelate ring. Such chelation could also enhance the
lipophilic character of the central metal atom, which subse-
quently favours its permeation through the lipid layer of the cell
membrane [32].
16,835
14,388
30,003; 27,980
23,614; 20,835
14,280
dx2 /dxz;yz
ꢀy2
dx2 /dxy
ꢀy2
Intraligand
Pseudo-
Tetrahedral
Charge transfer
dxy/dz2 ; dx2ꢀy2
(D4h) geometry around Cu(II) [24,25]. For these complexes meff < 2
(1.25–1.50 BM) suggests an antiferromagnetic interaction in the
dinuclear compounds [26].
In the electronic spectrum of complexes with thiocyanate, the
broad band was observed at 14,280–13,880 cmꢀ1 region due to
d
xy/dz2 ; dx2ꢀy2 transition, suggesting
a
pseudo-tetrahedral
Most of the Cu(II) tested compounds are less active towards
studied microorganisms in comparison to the control drug.
configuration around the central metal ion [24]. This complexes
show two extra absorption bands at 24,205–23,614 and 20,835–
20,375 cmꢀ1 respectively, which are attributed to ligand–metal
charge transfer. The complexes were found paramagnetic with
magnetic moments in 1.75–1.80 BM range, which is normal for
Cu(II) with pseudo-tetrahedral stereochemistry [24].
Table 4
UV–VIS spectral data (nm) for the uranyl complexes 4, 8, 12.
Compd.
p
/
p*; n / p*and charge transfer transitions
d / d transitions
The UV–VIS spectrum of uranyl complexes 4, 8, 12 (Table 4)
shows one or two bands in addition to the ligand bands. The first
band observed at >590 nm due to electronic transitions from apical
oxygen atom to the f-orbitals of uranyl atom is characteristic of the
uranyl moiety [24]. The second band observed at 694 nm in 8
corresponding to charge transfer from equatorial donor atoms of
HL1
4
266; 337; 365
263; 366
260; 336; 367
260; 373
263; 337; 378
261; 362
-
592
–
590; 694
–
HL2
8
HL3
12
594

M.V. Angelusiu et al. / European Journal of Medicinal Chemistry 44 (2009) 3323–3329
3327
Table 5
Table 6
The {g} parameter values for the Cu(II) complexes.
Antibacterial activities of ligands HL1, HL2, HL3 and Cu(II) and UO2(II) complexes 1–
12 as MIC values (
m
g/mL).
Compound
giso
g
gt
g1
g2
g3
k
Compd.
Gram-positive bacteriaa
Gram-negative
bacteriab
1a
1b
2
–
–
2.128
2.128
–
2.050
2.053
–
–
–
–
–
–
–
–
–
–
2.089
–
–
–
2.086
–
–
–
Se
Bs
Bc
Pa
Ec
3
–
–
2.024
–
–
–
2.036
–
–
–
2.094
–
–
–
2.089
–
–
–
2.219
–
–
–
2.195
–
–
-
HL1
1a
1b
2
1024
512
512
256
512
256
512
256
256
128
256
256
512
256
256
128
128
256
512
512
512
512
256
256
128
128
128
128
64
1024
512
512
512
1024
512
512
512
512
256
512
256
1024
512
512
512
512
512
1024
512
512
512
1024
512
512
512
512
512
256
128
1024
512
512
512
1024
512
1024
512
512
512
1024
512
512
256
256
256
512
128
512
256
256
256
256
256
5a
5b
6
2.135
2.149
–
2.071
2.071
–
7
–
–
3
4
9a
9b
10
11
2.127
2.162
–
2.050
2.055
–
HL2
5a
5b
6
2.090
–
–
–
2.040
2.088
2.246
7
8
64
Thiocyanato and acetato Cu(II) complexes inhibit the growth of
B. subtilis, similar to chloramphenicol. The UO2 derivatives are more
active than free ligands and have no significant effect against
P. aeruginosa, S. epidermidis and B. cereus comparative with control
drug.
HL3
9a
9b
10
11
12
128
128
128
64
64
256
4.2.2. Cell viability determination (MTS assay)
Control
64
64
128
64
128
The in vitro cytotoxicity of the ligands HL1, HL2, HL3 and some of
their Cu(II) and UO2(II) complexes, 1a, 3, 6, 7, 8, 9a, 11, 12 on human
promyelocytic leukemia cells HL-60 was determined by an MTS-
based assay [14]. Doxorubicin was used as reference. None of the
Control ¼ chloramphenicol.
a
Se (Staphylococcus epidermidis ATCC 14990); Bs (Bacillus subtilis ATCC 6633); Bc
(Bacillus cereus ATCC 14579).
b
Pa (Pseudomonas aeruginosa ATCC 9027); Ec (Escherichia coli ATCC 11775).
HN C4H9(n)
S
H2O
H
O
2
Ar
H
N
O
SCN
O
N
Cu
Cu
N
Ar
H
N
O
N
N
N
C4H9(n)
Ar
H
H
S
H2O
[Cu(Ln)2(H2O)2]
S
C4H9(n) NH
[Cu(Ln)(SCN)(H2O)]
(3) n=1 : X=H
(7) n=2 : X=Cl
(1a; 1b) n=1 : X=H
(5a; 5b) n=2 : X=Cl
(9a; 9b) n=3 : X=Br
(11) n=3 : X=Br
HN C4H9(n)
CH3
H2O
Ar
H2O
Cu
S
H
O
O
O
Ar
N
O
O
O
N
Cu
U
N
N
O
N
H
C
CH3
N
O
O
O
H
O
S
Ar
S
H2O
CH3
H2O
C4H9(n) NH
C
4H9(n) NH
[UO2(Ln)(AcO)]
(4) n=1 : X=H
(8) n=2 : X=Cl
[Cu(Ln)(AcO)(H2O)2]2
(2) n=1 : X=H
(6) n=2 : X=Cl
(10) n=3 : X=Br
O
S
(12) n=3 : X=Br
X
Ar =
O
Fig. 3. Proposed structures of the complexes 1–12.

3328
M.V. Angelusiu et al. / European Journal of Medicinal Chemistry 44 (2009) 3323–3329
compounds in the tested concentration inhibited cell proliferation
by 50% and therefore IC50 values could not be calculated.
vacuum and the crystals were washed with cold ethanol and
anhydrous diethylether and kept in a desiccator over fused CaCl2.
When we used CuCl2 and Cu(NO3)2 the same complexes were
obtained (1a, b; 5a, b; 9a, b). For uranyl(II) complexes it was used
UO2(CH3COO)2 and the work procedure was analogous.
5. Conclusions
The coordination ability of the N1-[4-(4-X-phenyl-
sulfonyl)benzoyl]-N4-butyl-thiosemicarbazide (X ¼ H, Cl, Br) has
been proved in complexation reaction with Cu(II) and UO2(II) ions.
The analytical and physico-chemical analyses confirmed the
composition and the structure of the newly obtained complex
combinations.
In all complexes the ligand acts as mononegative bidentate
bonding through the carbonyl/enolic oxygen and the hydrazinic
N2H nitrogen. Room temperature ESR spectra of Cu(II) complexes
yield {g} values characteristic of distorted octahedral and pseudo-
tetrahedral geometry. Infrared spectra indicate that complexes
contain six-coordinate uranium atom with the ligand atoms
arranged in an equatorial plane around the linear uranyl group.
The antibacterial data given for the compounds presented in this
paper allowed us to state that the (phenylsulfonyl)phenyl group is
not the main cause for the appearance of antibacterial activity and
the metal ion could be responsible for the variation of the anti-
bacterial activity. Results of antitumoral screening indicate that
both the ligands and their complexes have not presented cytotoxic
effects in micro-molar concentrations.
6.2. Antibacterial activity
Qualitative determination of antibacterial activity was done
using the disk diffusion method. Suspensions in sterile peptone
water from 24 h cultures of microorganisms were adjusted to 0.5
McFarland. These suspensions were inoculated in Muller–Hinton
Petri dishes of 90 mm. Paper disks (6 mm in diameter) containing
10 mL of the substance to be tested (at a concentration of 2048 mg/
mL in DMSO) were placed in a circular pattern in each inoculated
plate. Incubation of the plates was done at 37 ꢁC for 18–24 h.
Reading of the results was done by measuring the diameters of the
inhibition zones generated by the tested substances using a ruler.
Chloramphenicol was used as a reference substance.
Determination of MIC was done using the serial dilutions in
liquid broth method. The materials used were 96-well plates,
suspensions of microorganism (0.5 McFarland), Muller–Hinton
broth (Merck) and solutions of the substances to be tested
(2048
substances to be tested were obtained in the 96-well plates: 1024;
512; 256; 128; 64; 32; 16; 8; 4; 2
g/mL. After incubation at 37 ꢁC
mg/mL in DMSO). The following concentrations of the
Other investigations are in progress for this class of complex
combinations with acylthiosemicarbazides.
m
for 18–24 h, the MIC for each tested substance was determined by
macroscopic observation of microbial growth. It corresponds well
with the lowest concentration of the tested substance where
microbial growth was clearly inhibited.
Cytotoxicity of the tested compounds was determined by stan-
dard MTS assay [14].
6. Experimental protocols
6.1. Chemistry
The content of metallic ions was determined by atomic
absorption spectroscopy with AAS-1N spectrometer Carl Zeiss Jena;
C, H, and N were done with a Carlo Erba microdosimeter, after
drying the complexes at 105 ꢁC. The molar conductivity was
determined in DMSO (3 ꢂ 10ꢀ3 M), at room temperature, using OK-
102/1 Radelkis conductometer. Electronic spectra were recorded by
the diffuse-reflectance technique, using MgO as diluting matrix, on
a JASCO V-550 spectrophotometer. IR spectra were recorded with
a BioRad FTS 135 spectrophotometer in the 4000–400 cmꢀ1 region
using KBr pellets. The thermal analysis of the complexes was
carried out in static air atmosphere, with a sample heating rate of
10 ꢁC/min using DuPont 2000 ATG thermo-balance. ESR spectra
were recorded with an ART-6, model IFA-Bucharest, X-band spec-
trometer (9.01 GHz) online with a PC equipped with a 100 KHz field
modulation unit, on polycrystalline powders at room temperature.
The melting points were determinated with Boetius apparatus and
are higher than 250 ꢁC for all complexes. The required chemicals
were purchased from Merck and Chimopar, Bucharest and all
manipulations were performed using materials as received.
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