New heterocyclic compounds from 1,2,4-triazole and 1,3,4-thiadiazole class bearing diphenylsulfone moieties. Synthesis, characterization and antimicrobial activity evaluation

Article abstract of DOI:10.1016/j.ejmech.2012.01.031

Some new 5-(4-(4-X-phenylsulfonyl)phenyl)-4-(R)-2H-1,2,4-triazol-3(4H)- thiones 4a,b; 5a,b and 5-(4-(4-X-phenylsulfonyl)phenyl)-N-(R)-1,3,4-thiadiazol- 2-amines 6a,b; 7a,b were obtained by cyclization of new N¹-[4-(4-X- phenylsulfonyl)benzoyl]-N⁴-(R)-thiosemicarbazides 2a,b; 3a,b (X = H, Br). The 1,2,4-triazoles were synthesized by intramolecular cyclization of acylthiosemicarbazides, in basic media. On the other hand, 1,3,4-thiadiazoles were obtained from same acylthiosemicarbazides, in acidic media. These new intermediates from thiosemicarbazide class were afforded by the reaction of 4-(4-X-phenylsulfonyl)benzoic acids hydrazides (X = H, Br) 1a,b with 4-trifluoromethoxyphenyl or 3,4,5-trimethoxyphenyl isothiocyanate. The newly synthesized compounds were characterized by IR, ¹H NMR, ¹³C NMR, MS and elemental analysis. All the new compounds were screened for their antimicrobial activity against some bacteria (Staphylococcus aureus ATCC 25923, Bacillus cereus ATCC 13061, Escherichia coli ATCC 25922, Enterobacter cloacae ATCC 49141, Acinetobacter baumannii ATCC 19606 and Pseudomonas aeruginosa ATCC 27853) and yeasts (Candida albicans ATCC 90028 and Candida parapsilosis ATCC 22019).

Full text of DOI:10.1016/j.ejmech.2012.01.031

European Journal of Medicinal Chemistry 49 (2012) 417e423
Contents lists available at SciVerse ScienceDirect
European Journal of Medicinal Chemistry
journal homepage: http://www.elsevier.com/locate/ejmech
Short communication
New heterocyclic compounds from 1,2,4-triazole and 1,3,4-thiadiazole class
bearing diphenylsulfone moieties. Synthesis, characterization and antimicrobial
activity evaluationq
,
a
c
Stefania-Felicia Barbuceanu a, Gabriel Saramet b , Gabriela Laura Almajan , Constantin Draghici ,
*
Florica Barbuceanu d, Gabriela Bancescu e
a Organic Chemistry Department, Faculty of Pharmacy, Traian Vuia Street 6, 020956 Bucharest, Romania
b Pharmaceutical Techniques Department, Faculty of Pharmacy, Traian Vuia Street 6, 020956 Bucharest, Romania
c C.D. Nenitescu Institute of Organic Chemistry, Romanian Academy, Splaiul Independentei 202B, 060023 Bucharest, Romania
d Institute for Diagnosis and Animal Health, Dr. Staicovici Street 63, Bucharest, Romania
e Microbiology Department, Faculty of Dentistry, Calea Plevnei Street 19, 050051 Bucharest, Romania
a r t i c l e i n f o
a b s t r a c t
Article history:
Some new 5-(4-(4-X-phenylsulfonyl)phenyl)-4-(R)-2H-1,2,4-triazol-3(4H)-thiones 4a,b; 5a,b and 5-(4-
(4-X-phenylsulfonyl)phenyl)-N-(R)-1,3,4-thiadiazol-2-amines 6a,b; 7a,b were obtained by cyclization of
new N1-[4-(4-X-phenylsulfonyl)benzoyl]-N4-(R)-thiosemicarbazides 2a,b; 3a,b (X ¼ H, Br). The 1,2,4-
triazoles were synthesized by intramolecular cyclization of acylthiosemicarbazides, in basic media. On
the other hand, 1,3,4-thiadiazoles were obtained from same acylthiosemicarbazides, in acidic media.
These new intermediates from thiosemicarbazide class were afforded by the reaction of 4-(4-X-phe-
nylsulfonyl)benzoic acids hydrazides (X ¼ H, Br) 1a,b with 4-trifluoromethoxyphenyl or 3,4,5-
trimethoxyphenyl isothiocyanate. The newly synthesized compounds were characterized by IR, 1H
NMR, 13C NMR, MS and elemental analysis. All the new compounds were screened for their antimicrobial
activity against some bacteria (Staphylococcus aureus ATCC 25923, Bacillus cereus ATCC 13061, Escherichia
coli ATCC 25922, Enterobacter cloacae ATCC 49141, Acinetobacter baumannii ATCC 19606 and Pseudomonas
aeruginosa ATCC 27853) and yeasts (Candida albicans ATCC 90028 and Candida parapsilosis ATCC 22019).
Ó 2012 Elsevier Masson SAS. All rights reserved.
Received 30 September 2011
Received in revised form
7 January 2012
Accepted 15 January 2012
Available online 21 January 2012
Keywords:
1,2,4-Triazol-3-thione
1,3,4-Thiadiazol-2-amine
Acylthiosemicarbazide
Cyclization
Diphenylsulfone moiety
Antimicrobial activity
1. Introduction
have gained importance as they constitute the structural features of
many bioactive compounds. It is known that triazole and thiadia-
During the past decades, the incidence of microbial infection has
increased to alarming levels all over the world as a result of anti-
microbial resistance. Thus, in recent years, much attention has been
focused on addressing the problem of multi-drug resistant (MDR)
bacteria and fungi resulting from the widespread use and misuse of
classical antimicrobial agents. Due to this reason, discovering of
new classes of antimicrobial agents with novel mechanisms is
crucial to combat multi-drug resistant infections.
zole rings are included in the structure of various drugs [1e4]. From
these classes of heterocyclic compounds, the synthesis of new
derivatives of 1,2,4-triazole-3-thiones and 2-amino-1,3,4-
thiadiazoles has been attracting considerable attention because of
various biological properties such as: antibacterial [5e10], anti-
fungal [5,11,12], anti-tubercular [5,8,13], antiviral [6,7,13], antioxi-
dant [14,15], antitumoral [16e18], anti-inflammatory [19e21],
anticonvulsant [22e24] etc.
Organic compounds incorporating heterocyclic ring systems
continue to attract considerable interest due to their wide range of
biological activities. Among different five-membered heterocyclic
systems 1,2,4-triazoles and 1,3,4-thiadiazoles and their derivatives
On the other hand, literature survey revealed that diphe-
nylsulfone derivatives have antibacterial activity [25,26].
Motivated by these findings and in continuation of our ongoing
efforts on the synthesis of heterocycles with potential antimicro-
bial activities [27e32], we are purposed to synthesize and inves-
tigate the antimicrobial activity of a new series from 1,2,4-triazole
and 1,3,4-thiadiazole class having diarylsulfone moiety as phar-
macophore centre in 5 position and different radicals linked in 4
position of triazole or to amino group from 2 position of thiadia-
zole nucleus.
q
A part of this work was presented as poster presentation at 4th European
Conference on Chemistry for Life Sciences (4ECCLS), Budapest, Hungary, August
31eSeptember 3, 2011.
* Corresponding author. Tel.: þ40 723 492067.
E-mail address: saramet.gabriel@yahoo.com (G. Saramet).
0223-5234/$ e see front matter Ó 2012 Elsevier Masson SAS. All rights reserved.
doi:10.1016/j.ejmech.2012.01.031

418
S.-F. Barbuceanu et al. / European Journal of Medicinal Chemistry 49 (2012) 417e423
2. Chemistry
The 5-(4-(4-X-phenylsulfonyl)phenyl)-4-(R)-2H-1,2,4-triazol-
3(4H)-thiones 4a,b and 5a,b, in equilibrium with thiole tautomer,
were obtained by dehydrative intramolecular cyclization of
acylthiosemicarbazides when refluxed in 8% sodium hydroxide
solution, followed by treatment with 1% hydrochloric acid solution.
Intramolecular cyclization of same acylthiosemicarbazides in
the presence of concentrated sulphuric acid and followed by
treatment with a ammonia solution led to 5-(4-(4-X-phenyl-
sulfonyl)phenyl)-N-(R)-1,3,4-thiadiazol-2-amines 6a,b; 7a,b.
The structures elucidation of the newly synthesized compounds
was carried out by different spectroscopic techniques like IR, 1H
NMR and 13C NMR. Further confirmations of the compounds were
carried out by mass spectrometry and elemental analysis.
The synthetic route for the newly synthesized compounds,1,2,4-
triazoles, 1,3,4-thiadiazoles and their acylthiosemicarbazides
intermediary, is illustrated and outlined in Scheme 1.
The precursors, 4-(4-X-phenylsulfonyl)benzoic acid hydrazides
1a,b (X ¼ H, Br), were prepared, in several stages, according to the
literature method [33]. Thus, diarylsulfones (X ¼ H, Br), obtained by
tosylation of benzene or bromobenzene with 4-methylbenzene-1-
sulfonyl chloride, by oxidation with chromic anhydride and acetic
acid, led to 4-(4-X-phenylsulfonyl)benzoic acids. Ethyl 4-(4-X-
phenylsulfonyl)benzoates were synthesized by esterification reac-
tion of 4-(4-X-phenylsulfonyl)benzoic acids with ethanol, in the
presence of catalytic amount of sulphuric acid. In the final stage, the
4-(4-X-phenylsulfonyl)benzoic acid hydrazides 1a,b were obtained
by hydrazinolysis of ethyl 4-(4-X-phenylsulfonyl)benzoate with
hydrazine hydrate.
3. Antimicrobial activity
The
new
N1-[4-(4-X-phenylsulfonyl)benzoyl]-N4-(R)-thio-
The new synthesized compounds were tested for their in vitro
antimicrobial activity against the Gram-positive bacteria: Staphy-
lococcus aureus ATCC 25923, Bacillus cereus ATCC 13061, the Gram-
negative bacteria: Escherichia coli ATCC 25922, Enterobacter cloacae
ATCC 49141, Acinetobacter baumannii ATCC 19606, Pseudomonas
aeruginosa ATCC 27853 and the yeasts Candida albicans ATCC 90028
semicarbazides 2a,b; 3a,b used as the key intermediates for the
synthesis of 1,2,4-triazole and 1,3,4-thiadiazole derivatives were
synthesized by nucleophilic addition of 4-(4-X-phenylsulfonyl)
benzoic acid hydrazides 1a,b to 4-trifluoromethoxyphenyl or 3,4,5-
trimethoxyphenyl isothiocyanate.
Scheme 1.

S.-F. Barbuceanu et al. / European Journal of Medicinal Chemistry 49 (2012) 417e423
419
and Candida parapsilosis ATCC 22019, by using the broth micro-
dilution method for determination of MIC.
The assignments of the signals 13C NMR of these new
compounds 2e7 resulted from the 2D-HETCOR spectra.
The 1H NMR spectra of compounds 4 and 5 show a downfield
singlet resonating at 14.26e14.38 ppm characteristic for the NH
proton from 1,2,4-triazole-3-thione [13,14,36,37,39]. This strong
deshielding of NH is probably explained by the strong intermolecular
hydrogen bonding [40]. In compounds 6 and 7 appeared one singlet
4. Results and discussions
4.1. Chemistry
signaltypical of the NHgroup inthed range 10.64e10.90 ppm [19,23].
The structural assignments of new compounds were based on
their elemental analysis and spectral data (IR, 1H NMR, 13C NMR and
MS). The elemental analysis data and some physical properties of
these new compounds are reported in Table 1.
These findings in IR and NMR data of 1,2,4-triazole 4 and 5
clearly provide that these compounds predominantly exist, both in
solid state and in solution, in the thione form rather than the
tautomeric thiol form.
Thestructureof thiosemicarbazides2and3was confirmed by their
IR spectra which displayed absorption peaks at 3150e3438 cmꢀ1 for
NH, 1673e1686 cmꢀ1 for C]O and 1209e1236 cmꢀ1 corresponding
to C]S stretching vibrations. In the 1H NMR spectra of these new
compounds, the NH protons were observed as singlets at chemical
In 1H NMR spectra of compounds 3, 5 and 7 the protons of three
methoxysubstituents resonated as two singlets: at
for 4-OCH3 group and at
d
¼ 3.70e3.78 ppm
d
¼ 3.60e3.63 ppm for 3-OCH3 and 5-OCH3
which are equivalent [41]. Also, in 13C NMR spectra of these
compounds, the carbon atoms of methoxy substituents appear at
60.07e60.23 ppm (4-OCH3) and 55.81e56.23 ppm (3-OCH3 and
5-OCH3), respectively. The signal of OCF3 substituent from compounds
2, 4 and 6 appears in 13C NMR spectra as quartet at 119.91e121.85 ppm
with JC-F ¼ 254.3e256.9 Hz.
shift
signals at
d
9.75e10.89 ppm [14,19]. The 13C NMR spectra showed two
w181 ppm and w165 ppm characteristic to C]S and C]O
d
carbons, respectively, which confirm the formation of thio-
semicarbazides [14].
In the IR spectra of the new heterocyclic compounds 4e7 the
absorption band C]O from acylthiosemicarbazides disappeared,
which confirms that their cyclization reaction took place.
According to the IR spectroscopic data of the compounds 4 and 5
which have triazole-3-thione structure, the presence of C]S and
The mass spectra of all compounds displayed molecular ions
which confirmed their molecular weights (see Section 6). The
compounds which have bromine atom in their molecule show in
the mass spectrum the characteristic peaks corresponding to
isotopic distribution (79Br and 81Br isotopes).
NH stretching bands at 1216e1235 cmꢀ1 and 3413e3431 cmꢀ1
,
respectively [34,35] and the absence of an absorption about in
2600e2550 cmꢀ1 region for SH group [34,36,37] have proved that
these compounds predominantly exist, in solid state, in the tauto-
meric thione form.
The structure of compounds which contain thiadiazole nucleus
is confirmed by the presence in their IR spectra of a single
stretching band in 3241e3348 cmꢀ1 region due to NH group and by
4.2. Antimicrobial activity
The results of antimicrobial screening of newly prepared
compounds from 1,2,4-triazole, 1,3,4-thiadiazole and acylth-
iosemicarbazide class expressed as the MIC values, are summarized
in Table 2. Amicakin and fluconazole were used as standard drugs.
The investigations of antimicrobial screening data revealed that
all newly synthesized compounds exhibited poor antimicrobial
activity compared to that of the control drugs.
The results obtained on Gram-positive bacteria showed
a stronger action of all compounds tested against B. cereus compared
to S. aureus. Triazole 5b which has in position 4 on diphenylsulfone
moiety a bromine atom and at the nitrogen atom N-4 of triazole ring
the 3,4,5-trimethoxyphenyl fragment, presented the strongest
disappearance of nC]S absorption band from thiosemicarbazides.
Also, the IR spectra of triazoles and thiadiazoles showed new
absorption bands in region 1600e1620 cmꢀ1 due to C]N stretch-
ing vibrations that is an evidence for ring closure [19].
Transformation of acylthiosemicarbazides in heterocyclic
compounds from 1,2,4-triazole and 1,3,4-thiadiazole class is sup-
ported, from 13C NMR spectra, by the absence of carbonyl and thio-
carbonyl carbons signals characteristic to thiosemicarbazide. In the
spectra of compounds
6
and 7 appear two new signals at
action against B. cereus (MIC ¼ 8
7a and 7b showed good inhibitory activities against B. cereus
g/mL). So, all triazoles, thiadiazoles and thio-
semicarbazides containing 3,4,5-trimethoxyphenyl fragment have
better action against B. cereus group compared with derivatives
containing 4-trifluoromethoxyphenyl. Both thiosemicarbazides and
triazoles containing 3,4,5-trimethoxyphenyl fragment at the
mg/mL). Also compounds 3a, 3b, 5a,
d
164.73e165.35 and 155.40e156.28 ppm due to quaternary carbon
atoms C-2 and C-5 of the 1,3,4-thiadiazolic nucleus [14,38]. On the
other hand, 13C NMR spectra of compounds 4 and 5 show two new
signals characteristic to C-5 and C-3 quaternary carbon atoms from
1,2,4-triazole nucleus which appear in the region 148.97e149.07 and
168.92e168.98 ppm, respectively. The appearance of the C-3 carbon
(MIC ¼ 16
m
atom at
d
w 169 ppm indicates the presence of C]S [13,14,27,37,38].
nitrogen atom N-4 show lower MIC values (128 mg/mL) than those
Table 1
Characterization data of compounds 2e7.
Compd
X
R
Molecular formula
Molecular mass
M.p. (ꢁC)
Yield (%)
Elemental analysis found (calc)
C
H
N
2a
2b
3a
3b
4a
4b
5a
5b
6a
6b
7a
7b
H
Br
H
Br
H
Br
H
Br
H
Br
H
4-F3CO-C6H4
4-F3CO-C6H4
3,4,5-(H3CO)3-C6H2
3,4,5-(H3CO)3-C6H2
4-F3CO-C6H4
C21H16F3N3O4S2
C21H15BrF3N3O4S2
C23H23N3O6S2
C23H22BrN3O6S2
C21H14F3N3O3S2
C21H13BrF3N3O3S2
C23H21N3O5S2
C23H20BrN3O5S2
C21H14F3N3O3S2
C21H13BrF3N3O3S2
C23H21N3O5S2
495.49
574.39
501.58
580.47
477.48
556.38
483.56
562.46
477.48
556.38
483.56
562.46
190e192
199e201
178e181
184e186
259e261
237e240
264e266
156e158
235e236
249e250
272e274
300e302
98.1
95.2
96.2
87
63.5
80
70
62
89.2
91.6
75.5
74.0
50.86 (50.90)
43.86 (43.91)
55.01 (55.07)
47.52 (47.59)
52.90 (52.82)
45.29 (45.33)
57.07 (57.12)
49.02 (49.11)
52.79 (52.82)
45.40 (45.33)
57.08 (57.13)
49.18 (49.11)
3.19 (3.25)
2.57 (2.63)
4.57 (4.62)
3.75 (3.82)
2.91 (2.96)
2.30 (2.36)
4.33 (4.38)
3.51 (3.58)
3.01 (2.96)
2.30 (2.36)
4.42 (4.38)
3.62 (3.58)
8.51 (8.48)
7.36 (7.32)
8.43 (8.38)
7.18 (7.24)
8.74 (8.80)
7.49 (7.55)
8.63 (8.69)
7.42 (7.47)
8.74 (8.80)
7.59 (7.55)
8.72 (8.69)
7.41 (7.47)
4-F3CO-C6H4
3,4,5-(H3CO)3-C6H2
3,4,5-(H3CO)3-C6H2
4-F3CO-C6H4
4-F3CO-C6H4
3,4,5-(H3CO)3-C6H2
3,4,5-(H3CO)3-C6H2
Br
C23H20BrN3O5S2

420
S.-F. Barbuceanu et al. / European Journal of Medicinal Chemistry 49 (2012) 417e423
Table 2
Antimicrobial activities of compounds 2e7 as MIC values (mg/mL).
Compd.
Gram-positive
bacteriaa
Gram-negative bacteriab
Yeastsc
Sa
Bc
Ec
Ecl
Ab
Pa
Ca
Cp
2a
2b
3a
3b
4a
4b
5a
5b
6a
6b
7a
7b
256
512
128
128
256
512
128
128
512
512
512
512
2
32
32
16
16
32
32
16
8
32
32
16
16
e
128
128
128
128
128
256
128
128
128
128
128
64
128
128
128
128
128
256
128
128
128
128
128
128
e
64
64
32
32
32
32
32
32
32
32
32
32
e
64
64
64
64
64
64
64
64
64
64
64
64
2
64
64
64
64
128
128
64
64
64
128
64
64
e
64
64
64
64
64
64
32
16
64
64
64
64
e
Control (AM)
Control (FL)
2
e
e
e
e
e
e
e
2
Control: AM ¼ amikacin; FL ¼ fluconazole.
a
Sa (Staphylococcus aureus ATCC 25923); Bc (Bacillus cereus ATCC 13061).
Ec (Escherichia coli ATCC 25922); Ecl (Enterobacter cloacae ATCC 49141); Ab (Acinetobacter baumannii ATCC 19606); Pa (Pseudomonas aeruginosa ATCC 27853).
Ca (Candida albicans ATCC 90028); Cp (Candida parapsilosis ATCC 22019).
b
c
containing 4-trifluoromethoxyphenyl against S. aureus. All thiadia-
g/mL).
5. Conclusions
zoles showed the weakest action on S. aureus (MIC ¼ 512
m
This finding suggests that presence of OCH3 substituent in the
positions 3, 4 and 5 on the phenyl fragment, would be beneficial for
the activity against B. cereus and S. aureus (except thiadiazoles in case
of last strain) comparing to the situation when OCF3 substituent is
linked in the para position of the phenyl fragment.
The investigation of the biological action on Gram-negative
bacteria revealed that almost all compounds, especially those of
triazole and thiadiazole class, were active against A. baumannii
In this study we report the synthesis, characterization and anti-
microbial activity evaluation of new compounds from 1,2,4-triazole
and 1,3,4-thiadiazole class and their acylthiosemicarbazide inter-
mediates bearing diphenylsulfone moiety. The target compounds
from 1,2,4-triazole and 1,3,4-thiadiazole class were obtained from
intramolecular cyclization of some new acylthiosemicarbazides in
basic/acidic media. The intermediates from thiosemicarbazide class
were synthesized by reaction of 4-(4-X-phenylsulfonyl)benzoic
acids hydrazides with 4-trifluoro-methoxy/3,4,5-trimethoxyphenyl
isothiocyanate. The most antibacterial activity was presented by
(MIC ¼ 32
contain 4-trifluoromethoxyphenyl substituent at N-4 nitrogen
atom had a lower action (MIC ¼ 64 g/mL).
The action on P. aeruginosa could be characterized as a medium
one, MIC being of 64 g/mL, and was not influenced by the presence
mg/mL) and that only two thiosemicarbazides which
m
1,2,4-triazole 5b against B. cereus with MIC ¼ 8
1,2,4-triazole 5a,1,3,4-thiadiazoles 7a,b and acylthiosemicarbazides
3a,b display good activity against B. cereus (MIC ¼ 16 g/mL). The
most antifungal activity was presented by the same 1,2,4-triazole 5b
g/mL).
mg/mL. Also,
m
m
of the functional groups of the substitutes upon diphenylsulfone
fragment or on the nitrogen atoms, as in the previous case.
The compounds showed a uniform weaker action against E. coli
and E. cloacae, especially the triazole 4b, substituted at the nitrogen
atom N-4 with trifluoromethoxyphenyl fragment, which proved to
against C. parapsilosis (MIC ¼ 16
m
Making a general appreciation of the relationship between the
molecular structure and biological activity of the above mentioned
compounds, it might be concluded that in most cases:
be less active against both strains (MIC ¼ 256
7b substituted at the amino group with the trimethoxyphenyl frag-
g/mL).
The antifungal activity tested against C. albicans and
C. parapsilosis was characterized by medium and equal MIC values,
mg/mL). The thiadiazole
- the presence of OCH3 substituent in molecule increases, in the
most cases, the antimicrobial efficiency of corresponding
compounds;
- the presence of OCF3 substituent has decreased, generally, the
efficiency of studied compounds;
- the presence of bromine on the diphenylsulfone fragment has
little influence on the biological activity of tested compounds;
- the cyclization of the thiosemicarbazides to triazoles and
thiadiazole, in most cases, has not influenced too much the
action against the Gram-positive bacteria, Gram-negative
bacteria and fungi.
ment manifested the best action against E. coli (MIC ¼ 64
m
of 64
all containing trifluoromethoxyphenyl fragment, which showed
g/mL). Also, the results mentioned in
mg/mL, excepting the triazoles 4a and 4b, and thiadiazole 6b,
weaker action (MIC ¼ 128
m
Table 2 are indicating that the triazoles 5a and 5b have shown
a promising antifungal activity against C. parapsilosis, with MIC
values of 32 mg/mL and 16 mg/mL, respectively. These compounds
also contained a trimethoxyphenyl fragment in their structure.
In order to analyze the relationship: structureethe activity of
these compounds, the value of the logarithm of the partition
coefficient (log P) was determinated. The obtained data are pre-
sented in Table S.1 (in the Supplementary data section).
None of these compounds is effective against the tested micro-
organisms comparable with used drugs.
The lipophilicity (estimated by the n-octanol/water partition
coefficient, log P), varies between 2.79 for 3a and 5.0 for 6b. As
previously reported [10], no clear correlation could be established
between estimated values for log P and the antimicrobial activity.
Although p-Br substitution determines a considerable increase in
log P values (mean 0.65), this fact seems to have no correspondent
into the antimicrobial activity.
6. Experimental protocols
6.1. Chemistry
Melting points were determined with Boetius apparatus and are
uncorrected. The IR spectra (KBr pellets) were recorded on a Vertex
70 Bruker spectrometer. The NMR spectrawere recorded on a Varian

S.-F. Barbuceanu et al. / European Journal of Medicinal Chemistry 49 (2012) 417e423
421
Gemini 300 BB spectrometer working at 300 MHz for a 1H and
6.1.1.4. N1-[4-(4-Bromophenylsulfonyl)benzoyl]-N4-(3,4,5-
trimethoxyphenyl)-thiosemicarbazide 3b. IR (KBr,
, cmꢀ1): 3438,
75 MHz for 13C in DMSO-d6 solutions using TMS as an internal
standard. The mass spectra of the new compounds were registered
on a triple quadrupole mass spectrometer Varian 1200 L/MS/MS
with electrospray interface (ESI), coupled with a high performance
liquid chromatograph with Varian ProStar 240 SDM ternar pump
and a Varian ProStar 410 automatic injector. The instrument was
n
3303, 3150 (NH), 3087, 3003 (aromatic CeH), 2838 (CH3), 1680
(C]O), 1573, 1532, 1507, 1464 (C]C), 1322, 1300, 1159 (SO2), 1236
(C]Sþ CeOeC), 1128 (CeOeC), 576 (CeBr); 1H NMR (DMSO-d6,
d
ppm): 10.64 (bs, 1H, NH); 9.79 (bs, 2H, NH); 8.12 (s, 4H; aromatic
protons); 7.95 (d, 2H, J ¼ 8.8 Hz, aromatic protons); 7.75 (d, 2H,
J ¼ 8.8 Hz, aromatic protons); 6.82 (s, 2H, aromatic protons); 3.73
(s, 3H, 4-OCH3); 3.63 (s, 6H, 3,5-di-OCH3); 13C NMR (DMSO-d6,
operated in positive ions mode. The sample solution (2 mg/mL in
CHCl3/CH3OH 1/1, v/v) was introduced in the ESI interface by direct
infusion, after a tenth dilution with methanol, at a flow rate of
d ppm): 181.14 (C]S), 164.70 (C]O), 152.25, 143.32, 140.06,
20
m
L0/min. Elemental analyses were performed on ECS-40-10-
139.88, 137.30, 134.67, 133.05, 129.59, 129.36, 128.37, 127.58, 103.36
(aromatic ring carbons), 60.14 (4-OCH3), 55.92 (3,5-di-OCH3);
(ESIeMS) m/z: 580 [M þ H]þ; m/z: 582 [M þ H]þ.
Costeh micro-dosimeter, after drying the compounds at 105 ꢁC.
6.1.1. General procedure for synthesis of N1-[4-(4-X-phenylsulfonyl)
benzoyl]-N4-(R)-thiosemicarbazides 2a,b; 3b
6.1.2. General procedure for synthesis of 5-(4-(4-X-phenylsulfonyl)
phenyl)-4-(R)-2H-1,2,4-triazol-3(4H)-thiones 4a,b; 5a,b
An equimolar mixture (1 mmol) of 4-(4-X-phenylsulfonyl)-
benzoic acid hydrazide (X ¼ H, Br) 1 and arylisothiocyanate in
ethanol (5 mL) was refluxed for 16e19 h. The reaction mixture was
cooled to room temperature and the obtained precipitated was
filtered, washed with cold ethanol, dried and recrystallized from
ethanol.
A mixture of acylthiosemicarbazide 2 or 3 (1mmol) and 8%
sodium hydroxide solution (15 mL) was heated under reflux for 5 h.
The reaction mixture was filtered and the filtrate was cooled and
acidified with a diluted solution of hydrochloric acid (1%) to pH w 5.
The precipitate obtained was filtered, washed with water, dried and
finally recrystallized from CHCl3/petroleum ether (1:2, v/v).
6.1.1.1. N1-[4-(Phenylsulfonyl)benzoyl]-N4-(4-trifluoromethoxyphenyl)-
thiosemicarbazide 2a. IR (KBr,
n
, cmꢀ1): 3367, 3297 (NH), 3086,
6.1.2.1. 5-(4-(Phenylsulfonyl)phenyl)-4-(4-trifluoromethoxyphenyl)-
3069, 3043 (aromatic CeH), 1681 (C]O), 1579, 1531, 1488 (C]C),
2H-1,2,4-triazol-3(4H)-thione 4a. IR (KBr, n
, cmꢀ1): 3413 (NH), 3086,
1322, 1295, 1158 (SO2), 1261 (CeOeC), 1209 (C]S); 1H NMR
3024 (aromatic CeH), 1600 (C]N), 1578, 1512, 1474 (C]C), 1323,
(DMSO-d6,
d ppm): 10.89 (bs, 1H, NH); 9.97 (bs, 1H, NH); 9.82 (bs,
1298, 1159 (SO2), 1261 (CeOeC), 1216 (C]S); 1H NMR (DMSO-d6,
1H, NH); 8.14 (d, 2H, J ¼ 8.9 Hz, aromatic protons); 8.09 (d, 2H,
J ¼ 8.9 Hz, aromatic protons); 8.00 (dd, 2H, J ¼ 7.3, 1.6 Hz, aromatic
protons); 7.72 (tt, 1H, J ¼ 7.3, 1.6 Hz, aromatic proton); 7.64 (bt, 2H,
J ¼ 7.3 Hz, aromatic protons); 7.55 (bd, 2H, J ¼ 8.2 Hz, aromatic
protons); 7.33 (d, 2H, J ¼ 8.2 Hz, aromatic protons); 13C NMR
d
ppm): 14.38 (s, 1H, NH); 7.80 (d, 2H, J ¼ 8.6 Hz, aromatic protons);
7.75 (d, 2H, J ¼ 7.5 Hz, aromatic protons); 7.70 (tt, 1H, J ¼ 7.5, 1.5 Hz,
aromatic proton); 7.61 (t, 2H, J ¼ 7.5 Hz, aromatic protons); 7.56 (d,
2H, J ¼ 7.9 Hz, aromatic protons); 7.52 (d, 2H, J ¼ 8.6 Hz, aromatic
protons); 7.50 (d, 2H, J ¼ 7.9 Hz, aromatic protons); 13C NMR
(DMSO-d6,
d
ppm): 181.17 (C]S), 164.60 (C]O), 145.15, 143.78,
(DMSO-d6, d ppm): 168.91 (C3-triazolic ring), 149.01 (C5-triazolic
140.60, 138.32, 137.03, 133.99, 129.83, 129.19, 128.30, 127.48, 127.41,
120.69 (aromatic ring carbons); 120.52 (q, J ¼ 256.1 Hz, OCF3);
(ESIeMS) m/z: 496 [M þ H]þ.
ring), 148.65, 142.50, 140.33, 134.07, 133.05, 130.96, 130.34, 129.85,
129.50, 127.62, 127.53, 121.83 (aromatic ring carbons), 119.93 (q,
J ¼ 255.0 Hz, OCF3) (ESIeMS) m/z: 478 [M þ H]þ.
6.1.1.2. N1-[4-(4-Bromophenylsulfonyl)benzoyl]-N4-(4-trifluoro-
6.1.2.2. 5-(4-(4-Bromophenylsulfonyl)phenyl)-4-(4-trifluoro-
methoxyphenyl)-thiosemicarbazide 2b. IR (KBr,
n
, cmꢀ1): 3327, 3305,
methoxyphenyl)-2H-1,2,4-triazol-3(4H)-thione 4b. IR (KBr, n
, cmꢀ1):
3205 (NH), 3093, 3071, 3013 (aromatic CeH), 1686 (C]O), 1575,
1543, 1524, 1483 (C]C), 1321, 1293, 1159 (SO2), 1263 (CeOeC), 1210
3423 (NH), 3088, 3020 (aromatic CeH),1600 (C]N),1574,1512,1470
(C]C),1329,1290,1161 (SO2),1264(CeOeC),1217 (C]S), 574 (CeBr);
(C]S), 573 (CeBr); 1H NMR (DMSO-d6,
d
ppm): 10.84 (bs, 1H, NH);
1H NMR (DMSO-d6,
d
ppm): 14.35 (s, 1H, NH); 7.96 (d, 2H, J ¼ 8.6 Hz,
9.99 (bs, 1H, NH); 9.80 (bs, 1H, NH); 8.15 (d, 2H, J ¼ 9.0 Hz, aromatic
protons); 8.12 (d, 2H, J ¼ 9.0 Hz, aromatic protons); 7.93 (d, 2H,
J ¼ 8.8 Hz, aromatic protons); 7.86 (d, 2H, J ¼ 8.8 Hz, aromatic
protons); 7.52 (bd, 2H, J ¼ 8.8, 1.6 Hz, aromatic protons); 7.33 (d, 2H,
aromatic protons); 7.87 (d, 2H, J ¼ 8.4 Hz, aromatic protons); 7.82 (d,
2H, J ¼ 8.4 Hz, aromatic protons); 7.56 (d, 2H, J ¼ 9.8 Hz, aromatic
proton); 7.53 (d, 2H, J ¼ 8.6 Hz, aromatic protons); 7.51 (d, 2H,
J ¼ 9.8 Hz, aromatic protons); 13C NMR (DMSO-d6,
d ppm): 168.92
J ¼ 8.8 Hz, aromatic protons); 13C NMR (DMSO-d6,
d
ppm): 181.15
(C3-triazolic ring), 148.97 (C5-triazolic ring), 148.64, 141.99, 139.56,
132.96, 130.95, 130.85, 130.55, 129.54, 129.44, 128.35, 127.69, 121.82
(aromatic ring carbons),119.91 (q, J ¼ 254.5 Hz, OCF3); (ESIeMS) m/z:
556 [M þ H]þ; m/z: 558 [M þ H]þ.
(C]S), 164.56 (C]O), 145.18, 143.25, 139.82, 138.29, 137.20, 132.94,
129.50, 128.50, 128.26, 127.50, 127.35, 120.70 (aromatic ring
carbons); 120.86 (q, J ¼ 256.9 Hz, OCF3); (ESIeMS) m/z: 574
[M þ H]þ; m/z: 576 [M þ H]þ.
6.1.2.3. 5-(4-(Phenylsulfonyl)phenyl)-4-(3,4,5-trimethoxyphenyl)-
6.1.1.3. N1-[4-(Phenylsulfonyl)benzoyl]-N4-(3,4,5-trimethoxyphenyl)-
2H-1,2,4-triazol-3(4H)-thione 5a. IR (KBr, n
, cmꢀ1): 3418 (NH), 3086,
thiosemicarbazide 3a. IR (KBr,
n
, cmꢀ1): 3390, 3254, 3150 (NH),
3065, 3028 (aromatic CeH), 2958, 2838 (CH3), 1600 (C]N), 1543,
1505, 1465 (C]C), 1325, 1277, 1160 (SO2), 1234 (C]S þ CeOeC),
3094, 3066 (aromatic CeH), 2837 (CH3), 1673 (C]O), 1531, 1507,
1449 (C]C), 1320, 1295, 1156 (SO2), 1235 (C]S þ CeOeC), 1127
1128 (CeOeC); 1H NMR (DMSO-d6,
d ppm): 14.26 (s, 1H, NH);
(CeOeC); 1H NMR (DMSO-d6,
d
ppm): 10.78 (bs, 1H, NH); 9.75 (s,
7.97 (d, 2H, J ¼ 8.6 Hz, aromatic protons); 7.94 (dd, 2H, J ¼ 7.4,
1.5 Hz, aromatic protons); 7.93 (t, 2H, J ¼ 7.4 Hz, aromatic protons);
7.70 (tt, 1H, J ¼ 7.4, 1.5 Hz, aromatic proton); 7.60 (d, 2H, J ¼ 8.6 Hz,
aromatic protons); 6.75 (s, 2H, aromatic protons); 3.70 (s, 3H, 4-
2H, NH); 8.12 (s, 4H, aromatic protons); 8.00 (dd, 2H, J ¼ 7.2, 1.4 Hz,
aromatic protons); 7.72 (tt, 1H, J ¼ 7.2, 1.4 Hz; aromatic proton);
7.64 (t, 2H, J ¼ 7.2 Hz, aromatic protons); 6.81 (s, 2H, aromatic
protons); 3.73 (s, 3H, 4-OCH3); 3.63 (s, 6H, 3,5-di-OCH3); 13C NMR
OCH3); 3.60 (s, 6H, 3,5-di-OCH3); 13C NMR (DMSO-d6,
d ppm):
(DMSO-d6,
d
ppm): 181.14 (C]S), 164.67 (C]O), 152.18, 143.85,
168.98 (C3-triazolic ring), 149.05 (C5-triazolic ring), 153.04, 142.27,
140.46, 138.04, 133.98, 130.58, 129.80, 129.57, 129.19, 127.55, 127.43,
106.69 (aromatic ring carbons), 60.15 (4-OCH3), 56.17 (3,5-di-
OCH3); (ESIeMS) m/z: 484 [M þ H]þ.
143.76, 140.62, 137.13, 134.78, 134.02, 129.86, 129.22, 128.31, 127.43,
103.40 (aromatic ring carbons); 60.07 (OCH3), 55.86 (3,5-di-OCH3);
(ESIeMS) m/z: 502 [M þ H]þ.

422
S.-F. Barbuceanu et al. / European Journal of Medicinal Chemistry 49 (2012) 417e423
6.1.2.4. 5-(4-(4-Bromophenylsulfonyl)phenyl)-4-(3,4,5-trimethoxyph
enyl)-2H-1,2,4-triazol-3(4H)-thione 5b. IR (KBr,
, cmꢀ1): 3431 (NH),
6.1.3.4. 5-(4-(4-Bromophenylsulfonyl)phenyl)-N-(3,4,5-trimethoxyph
enyl)-1,3,4-thiadiazol-2-amine 7b. IR (KBr,
, cmꢀ1): 3270 (NH),
n
n
3088, 3002 (aromatic CeH), 2940, 2836 (CH3), 1600 (C]N), 1573,
1506, 1465 (C]C), 1324, 1280, 1160 (SO2), 1235 (C]S þ CeOeC),
3087, 3062 (aromatic CeH), 2940, 2840 (CH3), 1620 (C]N), 1573,
1509, 1463 (C]C), 1325, 1291, 1159 (SO2), 1237, 1128 (CeOeC); 573
(CeBr); 1H NMR (DMSO-d6, d ppm): 10.68 (s, 1H, NH); 8.08 (d, 2H,
J ¼ 8.8 Hz, aromatic protons); 8.04 (d, 2H, J ¼ 8.8 Hz, aromatic
protons); 7.93 (d, 2H, J ¼ 8.8 Hz, aromatic protons); 7.86 (d, 2H,
J ¼ 8.8 Hz, aromatic protons); 7.00 (s, 2H, aromatic protons); 3.78 (s,
1128 (CeOeC), 585 (CeBr); 1H NMR (DMSO-d6,
d ppm): 14.26 (s,
1H, NH); 7.99 (d, 2H, J ¼ 8.7 Hz, aromatic protons); 7.88 (d, 2H,
J ¼ 8.4 Hz, aromatic protons); 7.82 (d, 2H, J ¼ 8.4 Hz, aromatic
protons); 7.61 (d, 2H, J ¼ 8.7 Hz, aromatic protons); 6.75 (s, 2H,
aromatic protons); 3.70 (s, 3H, 4-OCH3); 3.61 (s, 6H, 3,5-di-OCH3);
3H, 4-OCH3); 3.62 (s, 6H, 3,5-di-OCH3); 13C NMR (DMSO-d6,
d ppm):
13C NMR (DMSO-d6,
d
ppm): 168.93 (C3-triazolic ring), 149.07 (C5-
165.35 (C2-thiadiazolic ring), 155.40 (C5-thiadiazolic ring), 153.15,
141.21, 139.99, 139.50, 136.38, 135.06, 133.00, 129.48, 128.43, 127.81,
126.64, 95.83 (aromatic ring carbons), 60.18 (4-OCH3), 55.81 (3,5-
di-OCH3); (ESIeMS) m/z: 562 [M þ H]þ; m/z: 564 [M þ H]þ.
triazolic ring), 153.11, 141.84, 139.72, 138.07, 132.99, 130.83, 129.62,
129.32, 128.56, 128.36, 127.69, 106.72 (aromatic ring carbons), 60.23
(4-OCH3), 56.23 (3,5-di-OCH3); (ESIeMS) m/z: 562 [M þ H]þ; m/z:
564 [M þ H]þ.
6.2. Antibacterial activity
6.1.3. General procedure for synthesis of 5-(4-(4-X-phenylsulfonyl)
phenyl)-N-(R)-1,3,4-thiadiazol-2-amines 6a,b; 7a,b
The stock solution (2048 mg/mL) of each compound was made
Appropriate acylthiosemicarbazide 2 or 3 (1 mmol) in 40 mL of
concentrated sulphuric acid was stirred at 0 ꢁC for 3 h and then
another 4 h at room temperature. To the resulting solution was
added, on ice bath, an aqueous ammonia till pH w 8 and then the
obtained precipitated was filtered, washed with water and recrys-
tallized from CHCl3/petroleum ether (1:2, v/v).
using dimethyl sulfoxide (DMSO) as solvent. The minimum inhib-
itory concentrations (MIC) of the new compounds were determined
by the broth microdilution method carried out in 96-well micro-
plates (Nunc, Denmark). Series of two-fold dilutions (from 1/2 to
1/1024) of the 12 compounds were made in cation-adjusted
}
Muller-Hinton broth when tested against the bacterial strains and
in Sabouraud broth when tested against the yeast strains.
The inoculum of the bacterial strains was obtained by sus-
pending 5 colonies from a 24 h culture obtained on Columbia blood
6.1.3.1. 5-(4-(Phenylsulfonyl)phenyl)-N-(4-trifluoromethoxyphenyl)-
1,3,4-thiadiazol-2-amine 6a. IR (KBr, n
, cmꢀ1): 3348 (NH), 3060, 3017
}
(aromatic CeH), 1614 (C]N), 1579, 1555, 1510, 1480 (C]C), 1323,
1308, 1156 (SO2),1264 (CeOeC); 1H NMR (DMSO-d6, d ppm): 10.88 (s,
1H, NH); 8.09 (d, 2H, J ¼ 9.0 Hz, aromatic protons); 8.06 (d, 2H,
J ¼ 9.0 Hz, aromatic protons); 7.99 (dd, 2H, J ¼ 7.5, 1.4 Hz, aromatic
protons); 7.77 (d, 2H, J ¼ 8.8 Hz, aromatic protons); 7.71 (tt,1H, J ¼ 7.5,
1.4 Hz, aromatic proton); 7.64 (t, 2H, J ¼ 7.5 Hz, aromatic protons);
agar, in 5 mL of Muller-Hinton broth. After vigorous shaking of the
microbial suspensions on a vortex-mixer for 1500, the turbidity was
adjusted at 0.5 McFarland standard with a densitometer (DEN-1,
BioSan), in order to achieve a concentration of 1.5 ꢂ108 bacterial
colony forming units (CFU)/mL. Afterwards, 0.1 mL of the above
prepared bacterial inoculum was added in a tube with 9.9 mL
7.37 (d, 2H, J ¼ 8.8 Hz, aromaticprotons); 13C NMR (DMSO-d6,
d
ppm):
Muller-Hinton broth and the concentration achieved after vortex
}
164.73 (C2-thiadiazolic ring), 156.28 (C5-thiadiazolic ring), 142.82,
141.91, 140.71, 139.29, 134.69, 133.94, 129.86, 128.35, 127.86, 127.42,
122.08,118.90 (aromatic ring carbons),121.85 (q, J ¼ 254.3 Hz, OCF3);
(ESIeMS) m/z: 478 [M þ H]þ.
mixing was of 1 ꢂ106 CFU/mL. An aliquot of 50
mL of the final
inoculum was added to all wells with 50 mL broth with compound,
except for the negative growth control well (the sterility control),
which contained only compound-free broth (100 L). The final
liquid volume in every well was of 100 L, including the positive
growth control (containing 50 L compound-free broth and 50
bacterial inoculum). In addition, an inoculum control was per-
formed by transferring 10 L from each bacterial growth control
m
m
6.1.3.2. 5-(4-(4-Bromophenylsulfonyl)phenyl)-N-(4-trifluoro-
m
mL
methoxyphenyl)-1,3,4-thiadiazol-2-amine 6b. IR (KBr, n
, cmꢀ1): 3241
(NH), 3087, 3057, 3015 (aromatic CeH), 1612 (C]N), 1573, 1556, 1510,
m
1493 (C]C), 1323, 1307, 1158 (SO2), 1264 (CeOeC), 571 (CeBr); 1H
well (just after the inoculum was added) into a tube with 10 mL
}
NMR (DMSO-d6,
d
ppm): 10.90 (s, 1H, NH); 8.08 (d, 2H, J ¼ 9.1 Hz,
Muller-Hinton broth, followed by vortex mixing and spreading of
aromatic protons); 8.04 (d, 2H, J ¼ 9.1 Hz, aromatic protons); 7.92 (d,
2H, J ¼ 8.8 Hz, aromatic protons); 7.85 (d, 2H, J ¼ 8.8 Hz, aromatic
protons); 7.77 (d, 2H, J ¼ 9.1 Hz, aromatic protons); 7.38 (d, 2H,
100 mL of this dilution onto a plate with Columbia blood agar, with
overnight incubation.
In case of the Candida reference strains, the inoculum was
obtained by suspending 5 colonies (obtained from a 24 h culture
on a Sabouraud dextrose agar) into 5 mL of sterile distilled water.
After vortex mixing the suspension for 1500, the turbidity was
adjusted at 0.5 McFarland, and afterwards, the inoculum was
diluted in sterile distilled water in order to obtain a working
suspension of 105 CFU/mL. The series of two-fold dilutions of the
compounds (from 1/2 to 1/1024) were made in Sabouraud broth,
and the inoculum was added into the microplates wells in the
same amount as the broth. In addition, the positive and negative
growth controls were prepared too. An inoculum control was
performed by transferring 10
after the inoculum was added) into a tube with 2 mL Sabouraud
broth, followed by vortex mixing. Afterwards, 100 L of this dilu-
tion was spread on Sabouraud dextrose agar plates, which were
incubated for 24e48 h.
J ¼ 9.1 Hz, aromatic protons); 13C NMR (DMSO-d6,
d ppm): 164.81 (C2-
thiadiazolic ring), 156.23 (C5-thiadiazolic ring), 142.82, 141.37, 139.96,
139.28, 134.89, 132.97, 129.44, 128.43, 128.19, 127.92, 122.08, 118.91
(aromatic ring carbons), 120.16 (q, J ¼ 255.7 Hz, OCF3); (ESIeMS) m/z:
556 [M þ H]þ; m/z: 558 [M þ H]þ.
6.1.3.3. 5-(4-(Phenylsulfonyl)phenyl)-N-(3,4,5-trimethoxyphenyl)-
1,3,4-thiadiazol-2-amine 7a. IR (KBr, n
, cmꢀ1): 3264 (NH), 3088, 3062
(aromatic CeH), 2966, 2840 (CH3), 1606 (C]N), 1580, 1564, 1509,
1462 (C]C), 1319, 1309, 1157 (SO2), 1240, 1129 (CeOeC); 1H NMR
(DMSO-d6, d ppm): 10.64 (s,1H, NH); 8.08 (d, 2H, J ¼ 8.8 Hz, aromatic
protons); 8.05 (d, 2H, J ¼ 8.8 Hz, aromatic protons); 8.00 (dd, 2H,
J ¼ 7.2, 1.9 Hz, aromatic protons); 7.72 (tt, 1H, J ¼ 7.2, 1.9 Hz, aromatic
proton); 7.65 (t, 2H, J ¼ 7.2 Hz, aromatic protons); 6.99 (s, 2H,
mL from the growth control well (just
m
aromatic protons); 3.78 (s, 3H, 4-OCH3); 3.63 (s, 6H, 3,5-di-OCH3); 13
C
NMR (DMSO-d6,
d
ppm): 165.34 (C2-thiadiazolic ring), 155.53 (C5-
The inoculum control plates and the microplates sealed with
sterile adhesive sheets and covered with proper lids were incu-
bated at 37 ꢁC for 20 h for the bacterial strains and for 24e48 h for
the yeasts strains (24 h for C. albicans and 48 h for C. parapsilosis).
thiadiazolic ring), 153.20, 141.80, 140.78, 139.51, 136.51, 134.90,
134.04, 129.15, 128.41, 127.82, 127.57, 95.85 (aromatic ring carbons),
60.22 (4-OCH3), 55.85 (3,5-di-OCH3); (ESIeMS) m/z: 484 [M þ H]þ.

S.-F. Barbuceanu et al. / European Journal of Medicinal Chemistry 49 (2012) 417e423
423
[13] I. Küçükgüzel, E. Tatar, S¸ .G. Küçükgüzel, S. Rollas, E. De Clercq, Eur. J. Med.
Chem. 43 (2008) 381e392.
[14] I. Khan, S. Ali, S. Hameed, N.H. Rama, M.T. Hussain, A. Wadood, R. Uddin,
Z. Ul-Haq, A. Khan, S. Ali, M.I. Choudhary, Eur. J. Med. Chem. 45 (2010)
5200e5207.
[15] G. Ayhan-Kilcigil, C. Kus, T. Çoban, B. Can-Eke, M. Iscan, J. Enz. Inhib. Med.
Chem. 19 (2004) 129e135.
[16] A. Duran, H.N. Dogan, S. Rollas, Il Farmaco 57 (2002) 559e564.
[17] W. Rzeski, J. Matysiak, M. Kandefer-Szerszen, Bioorg. Med. Chem. 15 (2007)
3201e3207.
[18] A.T. Mavrova, D. Wesselinova, Y.A. Tsenov, P. Denkova, Eur. J. Med. Chem. 44
(2009) 63e69.
[19] H. Kumar, S.A. Javed, S.A. Khan, M. Amir, Eur. J. Med. Chem. 43 (2008)
2688e2698.
[20] M. Amir, K. Shikha, Eur. J. Med. Chem. 39 (2004) 535e545.
[21] S.M. El-Moghazy, F.F. Barsoum, H.M. Abdel-Rahman, A.A. Marzouk, Med.
Chem. Res. (2011). doi:10.1007/s00044-011-9691-4.
[22] J.M. Kane, M.A. Staeger, C.R. Dalton, F.P. Miller, M.W. Dudley, A.M.L. Ogden,
J.H. Kehne, H.J. Ketteler, T.C. McCloskey, Y. Senyah, P.A. Chmielewski,
J.A. Miller, J. Med. Chem. 37 (1994) 125e132.
After the incubation period, the microbial growth in the wells
containing the tested compounds was examined macroscopically
and compared to the positive and negative growth controls. The
MIC value was considered to be the lowest concentration of the
compound which could inhibit the microbial growth, traduced by
the absence of any turbidity or growth button.
The investigation of the antimicrobial activity of the compounds
was done in duplicate and as control, S. aureus ATCC 25923, E. coli
ATCC 25922 and P. aeruginosa ATCC 27853 were tested against
amikacin, and C. parapsilosis ATCC 22019 against fluconazole by the
broth microdilution method [42,43]. The MIC value of amikacin was
2
mg/mL in case of all tested strains and the MIC value of fluconazole
was also 2 g/mL, in case of C. parapsilosis reference strain.
m
Because the MIC values are not spectacular, no statistical
calculations were made.
[23] H.N. Dogan, A. Duran, S. Rollas, G. Sener, M.K. Uysal, D. Gülen, Bioorg. Med.
Chem. 10 (2002) 2893e2898.
[24] R. Sharma, G.P. Misra, J. Sainy, S.C. Chaturvedi, Med. Chem. Res. 20 (2011)
Acknowledgements
245e253.
[25] E.F. Elslager, Z.B. Gavrilis, A.A. Phillips, D.F. Worth, J. Med. Chem. 12 (1969)
357e363.
[26] R. Wolf, H. Matz, E. Orion, B. Tuzun, Y. Tuzun, Dermatol. Online J. 8 (2002) 2.
[27] S.-F. Barbuceanu, G. Bancescu, O.D. Cretu, C. Draghici, A. Bancescu, M. Radu-
Popescu, Rev. Chim. (Bucharest) 61 (2010) 140e145.
This paper is supported by the Sectoral Operational Programme
Human Resources Development, financed from the European Social
Fund and by the Romanian Government under the contract number
POSDRU/89/1.5/S/64109.
ꢀ
ꢀ
ꢀ
[28] I. S¸ aramet, G.-L. Almajan, S¸ . Barbuceanu, C. Draghici, M.D. Banciu, Rev. Roum.
Chim. 50 (2005) 19e27.
Appendix. Supplementary material
[29] S.F. Barbuceanu, G.L. Almajan, I. Saramet, C. Draghici, R. Socoteanu,
F. Barbuceanu, J. Serb. Chem. Soc. 74 (2009) 1041e1049.
[30] S.-F. Barbuceanu, G.L. Almajan, I. Saramet, C. Draghici, A.I. Tarcomnicu,
G. Bancescu, Eur. J. Med. Chem. 44 (2009) 4752e4757.
[31] G.L. Almajan, S.-F. Barbuceanu, G. Bancescu, I. Saramet, G. Saramet, C. Draghici,
Eur. J. Med. Chem. 45 (2010) 6139e6146.
Supplementary data related to this article can be found online
at doi:10.1016/j.ejmech.2012.01.031.
[32] G.L. Almajan, S.-F. Barbuceanu, E.-R. Almajan, C. Draghici, G. Saramet, Eur. J.
Med. Chem. 44 (2009) 3083e3089.
References
[33] A. Mavrodin, V. Zotta, V.M. Stoenescu, D. Oteleanu, Pharm. Zentr. Deutsch. 95
(1956) 353e361.
[34] M.R. Banday, A. Rauf, Indian J. Chem. 48B (2009) 97e102.
[35] S. Shelke, G. Mhaske, S. Gadakh, C. Gill, Bioorg. Med. Chem. Lett. 20 (2010)
7200e7204.
[1] F. Sabatelli, R. Patel, P.A. Mann, C.A. Mendrick, C.C. Norris, R. Hare,
D. Loebenberg, T.A. Black, P.M. McNicholas, Antimicrob. Agents Chemother. 50
(2006) 2009e2015.
[2] T. El-Sayed Ali, A.M. El-Kazak, Eur. J. Chem. 1 (2010) 6e11.
ꢀ
ꢀ
[3] M. Serdar, N. Gümrükçüoglu, S¸ . Alpay Karaoglu, N. Demirbas¸ , Turk. J. Chem. 31
(2007) 315e326.
[36] Z. Cesur, N. Cesur, S. Birteksöz, G. Ötük, Acta Chim. Slov. 57 (2010) 355e362.
ꢂꢂ
ꢂ
[37] J. Tomasciková, J. Imrich, I. Danihel, S. Böhm, P. Kristian, J. Pisarcíková,
M. Sabol, K.D. Klika, Molecules 13 (2008) 501e518.
[4] N. Siddiqui, P. Ahuja, W. Ahsan, S.N. Pandeya, M.S. Alam, J. Chem. Pharm. Res.
1 (2009) 19e30.
[38] U. Salgın-Göks¸ en, N. Gökhan-Kelekçi, Ö. Göktas¸ , Y. Köysal, E. Kiliç, S¸ . Is¸ ik,
G. Aktay, M. Özalp, Bioorg. Med. Chem. 15 (2007) 5738e5751.
[5] N.U. Güzeldemirci, Ö. Küçükbasmaci, Eur. J. Med. Chem. 45 (2010) 63e68.
[6] S¸ .G. Küçükgüzel, I. Küçükgüzel, E. Tatar, S. Rollas, F. S¸ ahin, M. Güllüce, E. De
Clercq, L. Kabasakal, Eur. J. Med. Chem. 42 (2007) 893e901.
[7] M.T. Abdel-Aal, W.A. El-Sayed, A.H. Abdel Aleem, E.S.H. El Ashry, Pharmazie 58
(2003) 788e792.
ꢀ
[39] N.N. Gülerman, H.N. Dogan, S. Rollas, C. Johansson, C. Çelik, Il Farmaco 56
(2001) 953e958.
[40] G.A. Idrees, O.M. Aly, G. El-Din, A.A. Abuo-Rahma, M.F. Radwan, Eur. J. Med.
Chem. 44 (2009) 3973e3980.
[8] I. Küçükgüzel, S.G. Küçükgüzel, S. Rollas, M. Kiraz, Bioorg. Med. Chem. Lett. 11
(2001) 1703e1707.
[9] A.A. Kadi, N.R. El-Brollosy, O.A. Al-Deeb, E.E. Habib, T.M. Ibrahim, A.A. El-
Emam, Eur. J. Med. Chem. 42 (2007) 235e242.
[10] T. Plech, M. Wujec, A. Siwek, U. Kosikowska, A. Malm, Eur. J. Med. Chem. 46
(2011) 241e248.
[41] W. Xu, B. Song, P. Bhadury, Y. Song, D. Hu, Molecules 15 (2010) 766e779.
[42] European Committee for Antimicrobial Susceptibility Testing (EUCAST) of the
European Society of Clinical Microbiology and Infectious Diseases (ESCMID),
Determination of minimum inhibitory concentrations (MICs) of antibacterial
agents by broth dilution, Clin. Microbiol. Infect. 9 (2003) 1e7.
[43] Subcommittee on Antifungal Susceptibility Testing (EUCAST-AFST) of the
ESCMID European Committee for Antimicrobial Susceptibility Testing
(EUCAST-AFST) 2008, EUCAST definitive document EDef 7.1: method for the
determination of broth dilution MICs of antifungal agents for fermentative
yeasts, Clin. Microbiol. Infect. 14 (2008) 398e405.
[11] A.A. Siddiqui, A. Arora, N. Siddiqui, A. Misra, Indian J. Chem. 44B (2005)
838e841.
ꢁ
[12] C. Camoutsis, A. Geronikaki, A. Ciric, M. Sokovic, P. Zoumpoulakis, M. Zervou,
Chem. Pharm. Bull. 58 (2010) 160e167.