Synthesis and biological evaluation of novel nitrogen- and sulfur-containing hetero-1,4-naphthoquinones as potent antifungal and antibacterial agents

Article abstract of DOI:10.1016/j.ejmech.2011.09.048

1,4-Naphthoquinones are unique reagents in organic synthesis and have been employed in several well known and recently developed areas of application. Furthermore, these 1,4-naphthoquinones have demonstrated high reactivity in nucleophilic vinylic substit

Full text of DOI:10.1016/j.ejmech.2011.09.048

European Journal of Medicinal Chemistry 46 (2011) 5861e5867
Contents lists available at SciVerse ScienceDirect
European Journal of Medicinal Chemistry
journal homepage: http://www.elsevier.com/locate/ejmech
Original article
Synthesis and biological evaluation of novel nitrogen- and sulfur-containing
hetero-1,4-naphthoquinones as potent antifungal and antibacterial agents
,
b
c
a
d
Cemil Ibis a , Amac Fatih Tuyun , Zeliha Ozsoy-Gunes , Hakan Bahar , Maryna V. Stasevych ,
*
Rostyslav Ya. Musyanovych d, Olena Komarovska-Porokhnyavets d, Volodymyr Novikov d
a Istanbul University, Engineering Faculty, Department of Chemistry, Istanbul, Turkey
b Beykent University, Engineering & Architecture Faculty, Department of Chemical Engineering, Istanbul, Turkey
c Istanbul University, Hasan Ali Yucel Education Faculty, Department of Elementary Education, Division of Science Education, Istanbul, Turkey
d National University “Lviv Polytechnic”, Department of Technology of Biologically Active Substances, Pharmacy and Biotechnology, Lviv, Ukraine
a r t i c l e i n f o
a b s t r a c t
Article history:
1,4-Naphthoquinones are unique reagents in organic synthesis and have been employed in several well
known and recently developed areas of application. Furthermore, these 1,4-naphthoquinones have
demonstrated high reactivity in nucleophilic vinylic substitutions, in the preparation of sulfurated,
(hetero)cyclic and several other transformations. This study describes the synthesis and biological
evaluation of derivatives of monosulfurated naphthalene-1,4-dione (3), 3-chloro-2-ethoxy-naphthalene-
1,4-dione (4), disulfurated naphthalene-1,4-dione (5), and symmetrical bis-1,4-naphthoquinones (7, 9)
were obtained from the reaction of 2,3-dichloro-naphthaquinone (1) with S-, O-substituted mono-, di-,
and tetrathiols, respectively. The structures of the novel products were characterized by spectroscopic
methods.
Received 27 July 2011
Received in revised form
21 September 2011
Accepted 26 September 2011
Available online 5 October 2011
Keywords:
Antibacterial activity
Antifungal activity
2,3-Dichloro-1,4-naphthoquinone
Amino-sulfinylnaphthoquinone
Quinone
Crown Copyright Ó 2011 Published by Elsevier Masson SAS. All rights reserved.
1. Introduction
quinones have antifungal activities [7]. There are numerous reports
on biological evaluation of substituted 1,4-naphthoquinones that
(Hetero)cyclic quinones constitute an important group of
substrates. The structure of these substrates is often found in natu-
rally occurring compounds and is incorporated into synthetic bio-
logically active compounds [1]. Structureeactivity relationship
studies from quinonoid compounds showed that the position and
number of nitrogen atoms were considerably important factors to
affect the biological activities [2,3]. Generally, increasing the number
of substituent nitrogen atoms enhances the activities. There is
a report that bis(arylthio)-quinoline-5,8-diones and 6-arylamino-
quinoline-5,8-diones exhibited antifungal activity against patho-
genic fungi [4,5]. The presence of amino, thio, or chloro moiety on
the quinines was considerably important factor to effect antifungal
activity [6].
show the biological relevance of this system, in particular when they
contain thio substituents [8].
The incidence of fungal and bacterial infections still remains an
important and challenging problem because of the combination of
factors including emerging infectious diseases and also because of
increasing of multi-drug resistant microbial pathogens [9]. The
resistance of spectrum antifungal and antibacterial agents has
prompted us to discover and develop new antifungal and antibac-
terial drugs [10].
As part of our research program on the synthesis of biologically
active quinones, we became interested in the synthesis and biological
evaluation of 1,4-naphthoquinones containing nitrogen and sulfur
atom, having a range of similar redox potentials. The profound anti-
fungal and antibacterial activity exhibited by compounds [11] has
prompted us to synthesize of new hetero-1,4-naphthoquinones
containing nitrogen and sulfur atoms at 2- and 3-positions of 1,4-
naphthoquinone and study their biological activity. We report
herein a methodology concept in quinone chemistry to carry out
biological evaluation of some potent antifungal and antibacterial
agents.
Systemic fungal infections are seriously causes of mortality in HIV
infections and the emergence of multi-resistance strains is a signifi-
cant problem. It is already known that some sulfide-, sulfoxide-
* Corresponding author.
E-mail address: ibiscml@istanbul.edu.tr (C. Ibis).
0223-5234/$ e see front matter Crown Copyright Ó 2011 Published by Elsevier Masson SAS. All rights reserved.
doi:10.1016/j.ejmech.2011.09.048

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C. Ibis et al. / European Journal of Medicinal Chemistry 46 (2011) 5861e5867
2. Results and discussion
ethoxy derivatives. In the mass spectrum of the compounds 4c
and 4e the accurate mass measurement of the molecular ion peak
are noticed at m/z 306 (M)þ and 389 (M)þ, respectively. In the 1H
NMR spectra of 4c and 4e, protons in methylene group (-OeCH2e)
situated in ethoxy group and which are adjacent to the oxygen
atom are observed as multiplet at 4.4e4.8 ppm. However, these
peaks are not observed in the spectra of 5aeg since these
compounds are mono(thio)-substituted naphthoquinone. In the
mass spectrum of compounds 5aeg, the accurate mass measure-
ments of the molecular ion peaks were noticed at m/z 471 (M)þ, 506
(M)þ, 366 (M)þ, 578 (M)þ, 509 (M þ Na)þ, 382 (M)þ, and 401
(M þ Na)þ, respectively. The 13C NMR shifts of the methylene
carbon atoms of compound 4c and 4e -adjacent to the oxygen
atoms (-OeCH2e)- have showed their resonances in the downfield
at 69 ppm. The 13C NMR shifts of the carbon atoms of compounds
5aeg have appeared at around 150 ppm as one peak only, while the
carbon atoms of compounds 3aeb, 4c, and 4e have showed their
resonances at around 141 and 148 ppm as two peaks. The spectra of
compound 3aeb, 4c, and 4e, carbon atoms of carbonyl groups are
observed at around 175 and 180 ppm as two peaks while the carbon
atom signals of carbonyl groups of 5aeg have showed their reso-
nances at around 179 ppm as one peak only. For compounds 3aeb,
4c, and 4e, this is due to a carbonyl being beta to oxygen or chlorine
atoms and the other carbonyl being beta to sulfur atoms.
2.1. Chemistry
It is well known that the reaction of 2,3-dichloro-1,4-naphtho-
quinone with nucleophiles proceeds by nucleophilic substitution
whereas nucleophilic addition reactions of 1,4-naphthoquinones is
augmented by oxidative addition pathway [12]. Based on reactivity
and biological activity of 2,3-dichloro-1,4-naphthoquinone deriva-
tives [13], we have studied its reactions with different mono-, di-,
and tetrathiols (Scheme 1) in the presence or absence of a base as
reported and have evaluated their antifungal and antibacterial
activity.
Our investigation was to synthesize both di(thio)-substituted
products and mono(thio)-substituted products containing chlorine
atom. As intended, the di(thio)- and mono(thio)-substituted comp-
ounds were obtained. In some cases, mono(thio)-substituted comp-
ounds containing chlorine atom derivatives were not observed
potentially due to the decreased thiol amount in the medium of the
reaction, while the ethoxy derivatives of mono(thio)-substituted
compounds were obtained successfully.
The reaction of 2,3-dichloro-1,4-naphthoquinone (1) with
different alkyl-, arylthiols (1.1 equivalent) in ethanol in the pres-
ence of Na2CO3 gave 3aeb, 4c, 4e, and 5aeg compounds (Scheme
1). While compound 3aeb are mono(thio)-substituted naph-
thoquinone, the compound 4c and 4e is mono(thio)-substituted
The reaction of 2,3-dichloro-1,4-naphthoquinone (1) with 2,20-
thiodiethanethiol (8) resulted in the formation of intramolecular
S
O
O
O
O
O
O
O
S
S
S
S
S
S
S
S
S
S
S
S
S
O
S
O
10
11
9
SR1
R1
2,3,4,5
Cl
HS
SH CHCl3
NEt3
a
p-Cl-C6H4-CH2-
S
O
3
HO-(CH2)9-
HO-(CH2)4-
b
c
8
O
O
RSH
2
SR1
Cl
O2N
d
N
EtOH
Na2CO3
Cl
O
OCH2CH3
S
CH3
H3C
O
e
1
4
O
O
O
CH3
SR1
SR1
SH
HS
HS
O
O
O
O
CHCl3
f
NEt3
SH
O
N
O
O
6
O
N
g
5
O
O
O
O
O
S
S
S
S
O
O
O
O
O
O
O
7
Scheme 1. Reaction of 1,4-naphthoquinones with mono-, di-, and tetrathiols.

C. Ibis et al. / European Journal of Medicinal Chemistry 46 (2011) 5861e5867
5863
Table 1
cyclization to yield heterocyclic diquinone 7,8,10,11,20,21,23,24-
Antibacterial and antifungal activities of compounds by diffusion method.
octahydrodinaphtho[2,3-b:20,30-k] [1,4,7,10,13,16]hexathiacy-clooc-
tadecine-5,13,18,26-tetraone (9), condensed heterocyclic 2,3,5,6-
tetrahydronaphtho[2,3-b] [1,4,7]trithionine-8,13-dione (10), and
heterocyclic containing disulfide group 2,3,5,6,9,10,12,13-octahydr-
onaphtho[2,3-i] [1,2,5,8,11,14]hexathiacyclohexadecine-15,20-dione
(11) as exhibited in Scheme 1. In the mass spectrum of compounds
9, 10, and 11, the accurate mass measurements of the molecular ion
peaks were noticed at m/z 639 (M þ Na)þ, 308 (M)þ, and 460 (M)þ,
respectively.
Compounds Concentration Inhibition diameter of microorganism
(%)
growth, mm
Antibacterial activity
Antifungal
activity
E. coli S. aureus M. luteum C. tenuis A. niger
3a
3b
4c
4e
5a
5b
5c
5d
5e
5f
5g
7
0.5
0.1
0.5
0.1
0.5
0.1
0.5
0.1
0.5
0.1
0.5
0.1
0.5
0.1
0.5
0.1
0.5
0.1
0.5
0.1
0.5
0.1
0.5
0.1
0.5
0.1
0.1
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
7.0
0
0
0
0
0
14.0
10.0
0
7.0
0
0
0
0
0
0
It is pertinent to note that symmetrical bis-1,4-naphthoquinones
(7) were prepared through the addition of tetrathiol nucleophile 2,2-
19.4
12.0
0
0
0
0
0
0
26.0
18.0
8.0
0
0
0
7.0
0
9.0
6.0
0
25.4
14.7
0
0
0
0
0
0
31.0
22.0
11.7
0
0
0
10.4
7.7
11.7
6.7
0
14.7
8.4
0
0
7.4
0
10
0
0
0
0
0
6.0
0
6.0
0
bis(((3-mercaptopropanoyl)oxy)methyl)propane-1,3-diyl
bis(3-
mercaptopropanoate) (6) to naphthoquinone (1) representing
a common synthetic route to many fused heterocyclic rings which
have been used as synthetic intermediates in medicinal chemistry
and for dyestuffs.
Monosulfanyl-1,4-naphthoquinones (3) are (depending on the
character of thiol) positive by Beilstein’s test [14], and therefore,
contained chlorine, but and bissubstituted (sulfanyl- and ethoxy
sulfanyl) and cyclic 1,4-naphthoquinones (4, 5, 7, 9, 10, 11) are
negative by the same test because all chlorines have been
substituted by the thiolate (Scheme 1).
0
0
8.0
0
24.0
15.0
0
0
0
0
7.0
6.0
0
0
0
15.0
8.0
0
0
10.0
8.0
9.0
7.0
0
2.2. Biological activities as antibacterial and antifungal
0
0
0
15.0
0
0
0
18.0
0
0
0
9
In our new endeavors, we have synthesized different (hetero)
cyclic naphthoquinones and evaluated their antifungal activity
against fungi Candida tenuis VKM Y-70 and Aspergillus niger F-1119
by diffusion method [15] and serial dilution method [16] with
a view to develop therapeutic agents having broad spectrum of
antifungal activity. Antibacterial activity of synthesized compounds
was elucidated against Escherichia coli B-906, Staphylococcus aureus
209-P, and Mycobacterium luteum b-917 by diffusion method in
Table 1 and serial dilution method as shown in Tables 2 and 3. Their
activities were compared with those of the known antibacterial
agent Vancomicine and the antifungal agent Nystatin. Earlier
studies have led to the identification to potent antibacterial and
antifungal agents as lead molecules containing quinone chromo-
phore. Afterwards, on the basis of structureeactivity relationship of
antifungal activity of the (hetero)cyclic quinone derivatives, we
have further synthesized and screened antibacterial and antifungal
assay of 3aeb, 4c, 4e, 5aeg, 7, and 9 by diffusion method as shown
Table 1.
0
14.0
0
19.0
Ca
20.0
a
Vancomicine was used as a control in the tests of antibacterial activity of the
synthesized compounds, and Nystatin was used in the tests of antifungal activity of
the synthesized compounds.
Compound 5d (at 0.5% concentration) had better antifungal activity
against C. tenuis on comparison with Nystatin (Fig. 1).
Comparison of antibacterial activity with antibacterial drug
Vancomicine (at 0.1% concentration) showed that 4c (at 0.5%
concentration) and 5c (at 0.5 and 0.1% concentration) had better
activity against S. aureus and M. luteum (Fig. 2).
Evaluation of antibacterial activity of synthesized compounds
showed that 3a and 5b have MIC ¼ 500
m
m
g/mL, 5a and 5d have
g/mL for M. luteum. 4c
g/mL, 5g has MIC ¼ 62.5 g/mL for
MIC ¼ 125
m
g/mL, and 4c has MIC ¼ 31.2
and 5b have MIC ¼ 250
m
m
Data presented in Tables 1, 2, and 3 shows that there are
substances with antibacterial and fungicidal action among the
study compounds. The test-culture E. coli appeared not to be
sensitive to all compounds. The S. aureus and M. luteum was not
sensitive and low sensitive to compound 3aeb, 4e, 5aeb,def, 7, and
9 by diffusion method. The S. aureus strain was sensitive to
compound 4c at a concentration of 0.5% (diameter of the inhibition
zone was 19.4 mm), while the compound 5c at a concentration of
0.5% had diameter of the inhibition zone 26 mm.
Compounds 4c and 5c showed high activity against M. luteum at
0.5% (diameter of the inhibition zonee25.4 mm and 31 mm
respectively). Antifungal activity against C. tenuis was observed for
5d at concentration of 0.5% (d ¼ 24 mm). Compound 3a has low
activity against C. tenuis (d ¼ 14 mm at 0.5% concentration).
Compounds 3b, 4e, 5a, 5e, 7, and 9 have no antifungal activity
against A. niger at 0.5% and 0.1% evaluated concentrations by
diffusion method.
Table 2
Antibacterial activities of compounds by serial dilution method.
Compounds
MIC (mg/mL)
E. coli
S. aureus
M. luteum
3a
3b
4c
4e
5a
5b
5c
5d
5e
5f
5g
7
þ
þ
500.0
þ
þ
þ
þ
250.0
þ
31.2
þ
þ
þ
þ
125.0
þ
þ
250.0
15.6
þ
þ
15.6
125.0
þ
þ
þ
þ
þ
þ
*
500.0
þ
62.5
þ
500.0
þ
9
þ
þ
þ
Compound 3a and 4c (at 0.5% concentration) were found to
exhibit low antifungal activity against C. tenuis on comparison with
antifungal drug Nystatin evaluated by diffusion method.
þ: Growth of microorganisms.
*In the investigated concentrations the indexes of biocidic effect were not
determined.

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C. Ibis et al. / European Journal of Medicinal Chemistry 46 (2011) 5861e5867
Table 3
4. Experimental
Antifungal activities of compounds by serial dilution method.
4.1. Materials and methods
Compounds
MIC (mg/mL)
C. tenuis
A. niger
Melting points were measured using a Buchi B-540 melting
point apparatus and are uncorrected. Elemental analyses were
performed on a Thermo Finnigan Flash EA 1112 elemental analyzer.
Infrared (IR) spectra were recorded in KBr pellets in Nujol mulls on
a Perkin Elmer Precisely Spectrum One FTIR spectrometer. 1H NMR
(500 MHz) and 13C NMR (125 MHz) spectra were recorded in CDCl3,
DMSO on a Varian Unity INOVA spectrometer. Mass spectra were
obtained on a Thermo Finnigan LCQ Advantage MAX LC/MS/MS
spectrometer using the ESI or APCI technique. Products were iso-
lated by column chromatography on silica gel (Fluka silica gel 60,
3a
3b
4c
4e
5a
5b
5c
5d
5e
5f
5g
7
15.6
31.2
15.6
62.5
15.6
þ
15.6
þ
31.2
þ
31.2
þ
7.8
31.2
31.2
þ
15.6
125.0
15.6
125.0
15.6
31.2
62.5
500.0
þ
particle size 63e200
mm). Thin-layer chromatography (TLC) was
9
þ
performed on Merck silica gel plates (60F254), and detection was
carried out with ultraviolet light (254 nm). All chemicals were
reagent grade and used without further purification. Moisture was
excluded from the glass apparatus using CaCl2 drying tubes.
þ: Growth of microorganisms.
In the investigated concentrations the indexes of biocidic effect were not
determined.
4.2. General procedures for the synthesis of 1,4-naphthoquinones
S. aureus, and 5c has MIC ¼ 15.6
mg/mL for S. aureus and M. luteum
(Table 2 and Table 3).
4.2.1. General procedure 1: for the synthesis of mono-, disubstituted
thio-substituted-1,4-naphthoquinones, and ethoxy-substituted thio-
substituted-1,4-naphthoquinones
Sodium carbonate (1.52 g) was dissolved in ethanol as reaction
media (65 mL). 2,3-dichloro-1,4-naphthoquinone (1) and thiol
(2aeg) were added to the solution, respectively. Without heating,
the mixture was stirred for 6e8 h. The color of the solution changed
quickly, and the extent of the reaction was monitored by TLC. The
Evaluation of antifungal activity of compounds 3aeb, 4c, 4e,
5a, 5c, 5g, 7, and 9 showed their activity in concentrations
7.8e125 mg/mL against test-culture C. tenuis. MIC of 3a, 4c, 5a, 5c,
5d, 5f, and 5g was observed at 15.6e500
culture A. niger.
mg/mL against test-
3. Conclusion
reaction mixture was extracted in a Soxhlet extractor with
dichloromethane. After recovery of the solvent, the crude product
A convenient synthesis route of 2- and 2,3-substituted naph-
thalene-1,4-diones from 2,3-dichloro-1,4-naphthoquinone has
been reported. Among the synthesized compounds with antimi-
crobial activity at low concentrations against S. aureus, M. luteum
bacteria and C. tenuis and A. niger fungi in comparison with control
were identified. 2-chloro-3-((4-chlorobenzyl)thio)naphthalene-
1,4-dione (3a), 2-ethoxy-3-((4-hydroxybutyl)thio)naphthalene-
1,4-dione (4c), 2,3-Bis((4-chlorobenzyl)thio)naphthalene-1,4-
dione (5a), 2,3-Bis((4-hydroxybutyl)thio)naphthalene-1,4-dione
was purified by column chromatography.
4.2.1.1. 2-Chloro-3-((4-chlorobenzyl)thio)naphthalene-1,4-dione
(3a). Orange powder; yield 1.2 g (78%); m.p. 120.5e122.5 ꢀC; Rf:
0.82 (CHCl3); IR (KBr):
1589, 1496 (C]C), 1672, 1660 (C]O); 1H NMR (500 MHz, CDCl3):
4.52 (s, 2H, SeCH2), 7.17e7.23 (m, 4H, CHaromatic), 7.65e7.67 (m,
2H, CHaromatic), 7.98e8.05 (m, 2H, CHaromatic); 13C NMR (125 MHz,
CDCl3): 38.05 (SeCH2), 127.53, 129.17, 130.77, 131.39, 132.71,
n
(cmꢁ1) 3299, 3038 cmꢁ1 (CeHaromatic),
d
d
(5c),
2,3-bis((6-nitrobenzo[d]thiazol-2-yl)thio)naphthalene-1,4-
133.92, 134.18, 134.44, 135.45 (Caromatic), 148.13, 141.02 (]CeS),
180.11, 175.29 (C]O); MS (ESI): 349 (M)þ; Anal. Calcd. for
C17H10Cl2O2S: C, 58.47; H, 2.89; S, 9.18. Found C, 58.40; H, 2.97; S,
8.55.; Beilstein test [14]: Cl positive.
dione (5d), 2,3-bis((furan-2-ylmethyl)thio)naphthalene-1,4-dione
(5f), and 2,3-Bis(pyrimidin-2-ylthio)naphthalene-1,4-dione (5g)
are promising as biologically active compounds.
The latter approach mostly could rely on the coordination of
transition-metal cations to monosite (9, 10, 11) and/or multisite (7)
ligands. Investigations concerning the biological activity in science
of the compounds have presented herein.
4.2.1.2. 2-Chloro-3-((9-hydroxynonyl)thio)naphthalene-1,4-dione
(3b). Red powder; yield 0.53 g (30%); m. p. 62.3e62.5 ꢀC; Rf: 0.7
(CHCl3); IR (KBr):
n
(cmꢁ1) 3583 (OeH), 2926 (CeHaromatic), 2851
24
25
20
19
20
15
14.7
14
15
10
10
9
8
7.4
7
7
6
6
10
5
0
3a (C. Tenuis)
4c (C. Tenuis)
5f (A. Niger)
5a (C. Tenuis)
3a (A. Niger)
5g (A. Niger)
5c (C. Tenuis)
4c (A. Niger)
5d (C. Tenuis)
5b (A. Niger)
5g (C. Tenuis)
5c (A. Niger)
Nystatin (C. Tenuis)
5d (A. Niger)
Nystatin (A. Niger)
Fig. 1. Comparative antifungal study plot with Nystatin and compounds.

C. Ibis et al. / European Journal of Medicinal Chemistry 46 (2011) 5861e5867
5865
31
26
25.4
30
25
20
15
10
5
19.4
18
15
11.7
11.7
10.4
9
8
7
7
0
3a (S. aureus)
5g (S. aureus)
5d (M. luteum)
4c (S. aureus)
5c (S. aureus)
5g (M. luteum)
5d (S. aureus)
4c (M. luteum)
5f (S. aureus)
5c (M. luteum)
Vancomicine (S. aureus)
5f (M. luteum)
Vancomicine (M. luteum)
Fig. 2. Comparative antibacterial study plot with Vancomicine and compounds.
(CeHaliphatic), 1665 (C]O), 1590 (C]C); 1H NMR (500 MHz, CDCl3):
4.2.1.6. 2,3-Bis((9-hydroxynonyl)thio)naphthalene-1,4-dione
d
1.2e1.8 (m, 14H, CH2), 3.3 (t, J ¼ 7.32 Hz, 2H, -SeCH2), 3.5 (t,
(5b). Red powder; yield 0.74 g (42%); m. p. 72e72.2 ꢀC; Rf: 0.6
J ¼ 6.83 Hz, 2H,-OeCH2), 7.2e8.2 (m, 4H, Haromatic); 13C NMR
(CHCl3); IR (KBr):
(CeHaliphatic), 1665 (C]O), 1589 (C]C); 1H NMR (500 MHz, CDCl3):
1.1e1.6 (m, 28H, CH2), 3.2 (t, J ¼ 7.28, 2H, -SCH2), 3.5 (t, J ¼ 6.83,
2H, -OCH2), 7.60e8.0 (m, 4H, Haromatic); 13C NMR (125 MHz, CDCl3):
32.98, 30.63, 29.62, 29.53, 29.25, 28.88, 25.92 (-CH2), 35.17
n
(cmꢁ1) 3313 (OeH), 2924 (CeHaromatic), 2848
(125 MHz, CDCl3):
d 31.75, 29.40, 28.34, 28.27, 27.97, 27.58, 24.68
(eCH2), 33.32 (eSeCH2), 62.00 (HOeCH2), 133.09, 132.77, 131.62,
130.28, 126.86, 126.19 (Caromatic, CHaromatic), 138.75 (]CeS), 148.41
(]CeCl), 178.89 (C]O); MS (ESI): 366 (M)þ; Anal. Calcd. for
C19H23ClO3S: C, 62.20; H, 6.32; S, 8.74. Found C, 61.15; H, 5.20; S,
8.54; Beilstein test [14]: Cl positive.
d
d
(-SeCH2), 63.23 (-OeCH2), 148.11 (]CeS), 179.24 (C]O); MS (ESI):
506 (M)þ; Anal. Calcd. for C28H42O4S2: C, 66,36; H, 8.35; S, 12,65.
Found C, 65.28; H, 8.10; S, 13.01; Beilstein test [14]: Cl negative.
4.2.1.3. 2-Ethoxy-3-((4-hydroxybutyl)thio)naphthalene-1,4-dione
(4c). Red powder, yield 0.53 g (% 36); m. p. 64.6e64.8 ꢀC; Rf: 0.4
4.2.1.7. 2,3-Bis((4-hydroxybutyl)thio)naphthalene-1,4-dione (5c). Red
powder; yield 0.55 g (38%); m. p. 70.6e71 ꢀC; Rf: 0.3 (CHCl3); IR
(CHCl3); IR (KBr):
(CeHaliphatic), 1660 (C]O), 1591 (C]C); 1H NMR (500 MHz, CDCl3):
1.3e1.4 (q, 3H, CH3), 1.5e1.7 (m, 4H, CH2), 3.2 (t, 2H, J ¼ 6.83 Hz,
SeCH2), 3.6 (t, 2H, J ¼ 6.34 Hz eCH2eOH), 4.8 (q, 2H, OeCH2),
7.5e8.0 (m, 4H, Haromatic); 13C NMR (125 MHz, CDCl3):
14.91
(CH3), 25.59e30.61 (CH2), 31.78 (SeCH2), 61.11(CH2eOH), 69.01
(OeCH2), 125.38, 125.56, 130.42, 131.34, 132.56, 32.62 (Caromatic
n
(cmꢁ1) 3411 (OeH), 2979 (CeHaromatic), 2936
(KBr):
n
(cmꢁ1) 3533 (OeH), 2936 (CeHaromatic), 2862 (CeHaliphatic),
d
1662 (C]O), 1590 (C]C); 1H NMR (500 MHz, CDCl3):
d 1.6e1.8 (m,
8H, CH2), 3.2e3.3 (t, 4H, J ¼ 6.84 Hz, SeCH2), 3.5e3.7 (t, 4H, J ¼ 6.85,
d
CH2eOH), 7.95e8.05 (m, 4H, Haromatic); 13C NMR (125 MHz, CDCl3):
d
25.92, (SeCH2), 61.23 (CH2eOH), 125.91, 131.99, 132.51 (Caromatic,
,
CHaromatic), 146.84(]CeS), 177.97 (C]O); MS (ESI): 366 (M)þ; Anal.
Calcd. for C18H22O4S2: C, 58.99; H, 6.05; S, 17.50. Found C, 58.35; H,
6.20; S, 17.25; Beilstein test [14]: Cl negative.
CHaromatic), 133.26 (]CeS), 156.94 (]CeO), 177.86, 181.87 (C]O);
MS (ESI): 306 (M)þ; Anal. Calcd. for C16H18O4S: C, 62.72; H, 5.92; S,
10.47. Found C, 61.65; H, 5.76; S, 10.01; Beilstein test [14]: Cl
negative.
4.2.1.8. 2,3-Bis((6-nitrobenzo[d]thiazol-2-yl)thio)naphthalene-1,4-
dione (5d). Orange powder; yield 1.5 g (60%); m. p. 148.5e150 ꢀC; Rf
4.2.1.4. 2-Ethoxy-3-((2,4,6-trimethylbenzyl)thio)naphthalene-1,4-
: 0.50 (CHCl3); IR (KBr):
1520 (C]C), 1678 (C]O); 1H NMR (500 MHz, CDCl3):
(m, 10H, CHaromatic); 13C NMR (125 MHz, CDCl3):
116.76, 121.15,
n
(cmꢁ1) 3090 cmꢁ1 (CeHaromatic), 1573,
dione (4e). Orange powder; yield 0.51
125.1e126.4 ꢀC; Rf : 0.68 [PET/CH2Cl2(1:1)]; IR (KBr):
(CeHaromatic), 2987, 2944, 2959, 2909, 2857 (CeHaliphatic), 1671 (C]
O), 1590, 1556 (C]C); 1H NMR (500 MHz, CDCl3):
1.36 (t,
g
(32%); m. p.
n
d 7.69e8.67
(cmꢁ1) 3067
d
121.77, 126.06, 127.01, 131.17, 133.82 (Caromatic), 144.05 (]CeS),
147.85 (CeNO2), 155.33 (C]NeC-), 166.75 (SeCeS), 176.57 (C]O);
MS (ESI): 578 (M)þ; Anal. Calcd. for C24H10N4O6S4: C, 49.82; H, 1.74;
N, 9.68; S, 22.17. Found C, 49.15; H, 1.69; N, 8.56; S, 15.90; Beilstein
test [14]: Cl negative.
d
J ¼ 7.32 Hz, 3H, CH3), 2.19 (s, 3H, CH3), 2.36 (s, 6H, CH3), 4.39e4.43
(m, 4H, SeCH2, OeCH2), 6.79 (s, 2H, CHaromatic), 7.62e7.64 (m, 2H,
CHaromatic), 7.98e8.00 ppm (m, 2H, CHaromatic); 13C NMR (125 MHz,
CDCl3):
d 14.9, 18.6, 18.6, 19.9 (CH3), 31.8 (SeCH2), 69.1 (OeCH2),
125.4, 125.6, 128.1, 128.8, 130.5, 131.5, 132.5, 132.6, 134.6, 136.3,
136.7 (CHaromatic, Caromatic), 156.6 (OeCeC]O), 177.9, 181.9 (C]O);
MS (ESI): 389 (M þ Na)þ; Anal. Calcd. for C22H22O3S: C, 72.10; H,
6.05; S, 8.75%. Found C, 71.72; H, 6.03; S, 8.99%; Beilstein test [14]:
Cl negative.
4.2.1.9. 2,3-Bis((2,4,6-trimethylbenzyl)thio)naphthalene-1,4-dione
(5e). Yelow powder; yield 0.73 g (34%); m. p. 252.1e254.4 ꢀC; Rf :
0.80 [PET/CH2Cl2(1:1)]; IR (KBr):
2913, 2859 (CeHaliphatic), 1665 (C]O), 1590 (C]C); 1H NMR
(500 MHz, CDCl3): 2.17 (s, 6H, CH3), 2.34 (s, 12H, CH3), 4.50 (s, 4H,
n
(cmꢁ1) 3004 (CeHaromatic), 2968,
d
SeCH2), 6.76 (s, 4H, CHaromatic), 7.64e7.66 (m, 2H, CHaromatic),
4.2.1.5. 2,3-Bis((4-chlorobenzyl)thio)naphthalene-1,4-dione
Orange powder; yield 1.6 g (77%); m. p. 137.5e139 ꢀC; Rf : 0.77
(CHCl3); IR (KBr):
(cmꢁ1) 3064 cmꢁ1 (CeHaromatic), 1591, 1496 (C]
C), 1661 (C]O); 1H NMR (500 MHz, CDCl3):
4.35 (s, 4H, SeCH2),
7.10e7.22 (m, 4H, CHaromatic), 7.59e7.62 (m, 4H, CHaromatic),
7.90e7.93 (m, 4H, CHaromatic); 13C NMR (125 MHz, CDCl3):
37.39
(5a).
8.03e8.05 ppm (m, 2H, CHaromatic); 13C NMR (125 MHz, CDCl3):
d
18.6, 19.9 (CH3), 33.8 (SeCH2), 125.9, 128.1, 128.5, 132.0, 132.5,
n
136.4, 136.7, 147.1 (CHaromatic, Caromatic), 178.2 (C]O); MS (ESI): 509
(M þ Na)þ; Anal. Calcd. for C30H30O2S2: C, 74.04; H, 6.21; S, 13.18.
Found C, 73.75; H, 6.12; S, 13.10; Beilstein test [14]: Cl negative.
d
d
(SeCH2), 125.77, 126.22, 127.65, 129.37, 131.69, 132.54, 134.74 (Car-
omatic), 146.27 (]CeS), 177.90 (C]O); MS (ESI): 471 (M)þ; Anal.
Calcd. for C24H16Cl2O2S2: C, 61.15; H, 3.42; S, 13.60. Found C, 58.83;
H, 3.06; S, 10.21; Beilstein test [14]: Cl positive.
4.2.1.10. 2,3-Bis((furan-2-ylmethyl)thio)naphthalene-1,4-dione
(5f). Red powder; yield 0.65 g (39%); m. p. 110e111.5 ꢀC; Rf: 0.56
(CHCl3); IR (KBr):
n
(cmꢁ1) 3141, 3021 (CeHaromatic), 1587, 1458 (C]
C), 1648 (C]O); 1H NMR (500 MHz, CDCl3):
d
4.41 (s, 4H, SeCH2),

5866
C. Ibis et al. / European Journal of Medicinal Chemistry 46 (2011) 5861e5867
6.00 (d, J ¼ 0.98, 2H, CHfuran), 6.10 (dd, J ¼ 1.95, J ¼ 1.95, 2H, CHfuran),
7.15 (d, J ¼ 0.98, 2H, OeCHfuran), 7.60 (dd, J ¼ 3.42 Hz, J ¼ 3.42 Hz,
2H, Haromatic), 7.95 (dd, J ¼ 3.42 Hz, J ¼ 3.42 Hz, 2H, Haromatic); 13C
(CeHaliphatic), 1659, 1644 (C]O), 1590 (C]C); 1H NMR (500 MHz,
CDCl3):
2.85 (t, J ¼ 5.86 Hz 4H, SeCH2), 3.74 (t, J ¼ 5.86 Hz 4H,
SeCH2), 7.63e7.65 (m, 2H, CHaromatic), 8.01e8.03 (m, 2H, CHaromatic);
13C NMR (125 MHz, CDCl3):
34.5, 37.6 (CH2), 127.1, 132.3, 133.8
d
NMR (125 MHz, CDCl3):
d
26.64 (SeCH2), 122.35, 129.02
d
(CeHaromatic), 128.43 (Caromatic), 103.95, 105.94, 137.97 (CHfuran),
143.07 (]CeS), 146.21 (Cfuran), 174.45 (C]O); MS (ESI): 382 (M)þ,
300 (MeC5H5O)þ, 259 (MeC5H5OS)þ; Anal. Calcd. for C20H14O4S2:
C, 62.81; H, 3.69; S, 16.77. Found C, 63.25; H, 3.83; S, 18.14; Beilstein
test [14]: Cl negative.
(CHaromatic, Caromatic), 146.2 (SeCeC]O), 180.7 (C]O); MS (ESI): 308
(M)þ; Anal. Calcd. for C14H12O2S3: C, 54.52; H, 3.92; S, 31.19. Found C,
54.25; H, 4.01; S, 31.38; Beilstein test [14]: Cl negative.
4.2.2.4. 2,3,5,6,9,10,12,13-Octahydronaphtho[2,3-i] [1,2,5,8,11,14]hex-
athiacyclohexadecine-15,20-dione (11). Orange powder; yield 0.05 g
4.2.1.11. 2,3-Bis(pyrimidin-2-ylthio)naphthalene-1,4-dione
(4%); m. p. 135.9e136.8 ꢀC; Rf : 0.57 [PET/CH2Cl2(1:1)]; IR (KBr):
n
(5g). Yelow powder; yield 1.24 g (75%); m. p. 161.5e163 ꢀC; Rf : 0.16
(cmꢁ1) 2960, 2919, 2850 (CeHaliphatic), 1661, 1650 (C]O), 1588 (C]
C); 1H NMR (500 MHz, CDCl3):
2.80e2.83 (m, 12H, SeCH2),
(CHCl3); IR (KBr):
n
(cmꢁ1) 3029 (CeHaromatic), 1554, 1524 (C]C),
d
1727, 1668 (C]O); 1H NMR (500 MHz, CDCl3):
d
6.96 (t, J ¼ 4.88 Hz,
3.45e3.47 (m, 4H, SeCH2), 7.65e7.66 (m, 4H, CHaromatic),
2H, CHeCHpyrimidineeCH), 7.69 (dd, J ¼ 2.93 Hz, J ¼ 3.42 Hz, 2H,
Haromatic), 8.04 (dd, J ¼ 3.42 Hz, J ¼ 3.41 Hz, 2H, Haromatic), 8.40 (d,
7.99e8.02 ppm (m, 4H, CHaromatic); 13C NMR (125 MHz, CDCl3):
d
31.3, 32.5, 34.2, 38.28 (CH2), 126.1, 131.9, 132.7 (CHaromatic, Car-
4.88 Hz, 4H, NeCHpyrimidine); 13C NMR (125 MHz, CDCl3):
d
118.09
omatic), 147.3 (SeCeC]O), 177.9 (C]O); MS (ESI): 460 (M)þ; Anal.
Calcd. for C18H20O2S6: C, 46.92; H, 4.38; S, 41.76. Found C, 46.38; H,
4.03; S, 40.35; Beilstein test [14]: Cl negative.
(CHeCHpyrimidineeCH), 127.72 (CeHaromatic), 133.19 (Caromatic), 134.15
(CeHaromatic), 149.03 (]CeS), 157.84 (NeCHpyrimidine), 170.43
(NeCaromaticeN), 179.07 (C]O); MS (ESI): 401 (M þ Na)þ, 267
(MeC4H3N2S)þ; Anal. Calcd. for C18H10N4O2S2: C, 57.13; H, 2.66; S,
16.95. Found C, 56.16; H, 3.58; S,17.28; Beilstein test [14]: Cl negative.
4.3. Antifungal and antibacterial evaluation
4.3.1. Diffusion technique
4.2.2. General procedure 2: for the synthesis of cyclic 1,4-
naphthoquinones
Antimicrobial activity of compounds was evaluated by diffusion
in peptone on nutrient medium (meat-extract agar for bacteria;
wort agar for fungi). The microbial loading was 109 cells (spores)/
1 mL. The required incubation periods were as: 24 h at 35 ꢀC for
bacteria and 48e72 h at 28e30 ꢀC for fungi. The results were
recorded by measuring the zones surrounding the disk. Control
disk contained Vancomicine (for bacteria) or Nistatine (for fungi) as
a standard.
2,3-dichloro-1,4-naphthoquinone (1) and thiol (6 and 8) were
stirred in chloroform as solvent (50 mL). Triethylamine (1 mL) or
sodium carbonate (1.52 g) was added to the reaction mixture
slowly. Without heating, the mixture was stirred for 4 h. The color
of the solution changed quickly, and the extent of the reaction was
monitored by TLC. Chloroform was added to the reaction mixture to
separate the organic layer. Then, the organic layer was washed with
water (5 ꢂ 30 mL) and dried with Na2SO4. After filtering, the
solvent was evaporated, and the residue was purified by column
chromatography on silica gel.
4.3.2. Serial dilution technique
Testing was performed in a flat-bottomed 96-well tissue culture
plate. The tested compounds were dissolved in DMSO, and arriving
the necessary concentration. The exact volume of solution of
compounds is brought in nutrient medium. The inoculum of
bacteria and fungi was inoculated in nutrient medium (meat-
extract agar for bacteria; wort agar for fungi). The duration of
incubation was at 37 ꢀC for bacteria and 30 ꢀC for fungi during
24e72 h. The results were estimated according to the presence or
absence of microorganism growth.
4.2.2.1. 2,20,3,30,11,110,12,120-octahydro-7,70-spirobi[naphtho[2,3-j]
[1,5,9,12]dioxadithiacyclopentadecin]-4,40,10,100,14,140,19,190(6H,60H,
8H,80H)-octaone (7). Yellow powder; yield 1 g (57.5%); m. p. 205 ꢀC
(decomp.); Rf: 0.22 (CH2Cl2); IR (KBr):
1590, 1497 (C]C), 1739, 1662 (C]O); 1H NMR (500 MHz, CDCl3):
2.61e2.68 (m, 8H, (C]O)eCH2), 3.45e3.49 (m, 8H, SeCH2), 4.07
(s, 8H, OeCH2), 7.81e7.84 (m, 2H, CHaromatic), 7.95e7.99 (m, 2H,
CHaromatic); 13C NMR (125 MHz, CDCl3):
29.79 (SeCH2), 35.31 ((C]
n
(cmꢁ1) 3044 (CHaromatic),
d
d
Acknowledgments
O)eCH2), 35.65 (-C-), 63.64 (SeCH2), 134.56, 133.59, 127.26 (Car-
omatic), 147.29 (]CeS), 178.88, 171.72 (C]O); MS (ESI): 796 (M)þ;
Anal. Calcd. for C37H32O12S4: C, 55.77; H, 4.05; S, 16.09. Found C,
54.70; H, 4.85; S, 14.19; Beilstein test [14]: Cl negative.
The financial support from TUBITAK for Ukraine-Turkey agree-
ment gratefully acknowledged (Project No.109T617) and from State
Agency on Science, Innovations and Informatization of Ukraine
(Project No. M/309-2011).
4.2.2.2. 2-((2-((2-((1,4-Dioxo-3-((2-(propylthio)ethyl)thiwo)-1,4-
dihydronaphthalen-2-yl)thio)ethyl)thio)ethyl)thio)-3-mercaptona-
phthalene-1,4-dione (9). Orange powder; yield 0.12 g (9%); m. p.
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n ) 2962, 2917, 2851
(cmꢁ1

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