Synthesis and antimicrobial evaluation of 1-{3-[(furan-2-ylmethyl)sulfanyl] propanoyl}-4-substituted thiosemicarbazides and their products of cyclization to 1,2,4-triazole ring

Article abstract of DOI:10.1080/10426507.2013.820185

By the reaction of 3-[(furan-2-ylmethyl)sulfanyl]propanoylhydrazide with various isothiocyanates, the corresponding 4-substituted 1-[(furan-2-ylmethyl) sulfanyl] propanoylthiosemicarbazide derivatives (2-5) were obtained. Thiosemicarbazide derivatives (2-

Full text of DOI:10.1080/10426507.2013.820185

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Synthesis and Antimicrobial
Evaluation of 1-{3-[(Furan-2-
Ylmethyl)Sulfanyl] Propanoyl}-4-
Substituted Thiosemicarbazides and
their Products of Cyclization to 1,2,4-
Triazole Ring
Nazar Trotsko a , Monika Wujec a , Urszula Kosikowska b & Anna Malm
b
a Department of Organic Chemistry, Faculty of Pharmacy , Medical
University , 4A Chodźki, 20-093 , Lublin , Poland
b Department of Pharmaceutical Microbiology, Faculty of Pharmacy ,
Medical University , 1 Chodźki, 20-093 , Lublin , Poland
Accepted author version posted online: 02 Sep 2013.Published
online: 28 Jan 2014.
To cite this article: Nazar Trotsko , Monika Wujec , Urszula Kosikowska & Anna Malm (2014)
Synthesis and Antimicrobial Evaluation of 1-{3-[(Furan-2-Ylmethyl)Sulfanyl] Propanoyl}-4-Substituted
Thiosemicarbazides and their Products of Cyclization to 1,2,4-Triazole Ring, Phosphorus, Sulfur, and
Silicon and the Related Elements, 189:3, 293-299, DOI: 10.1080/10426507.2013.820185
To link to this article: http://dx.doi.org/10.1080/10426507.2013.820185
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Phosphorus, Sulfur, and Silicon, 189:293–299, 2014
Copyright ꢀC Taylor & Francis Group, LLC
ISSN: 1042-6507 print / 1563-5325 online
DOI: 10.1080/10426507.2013.820185
SYNTHESIS AND ANTIMICROBIAL EVALUATION
OF 1-{3-[(FURAN-2-YLMETHYL)SULFANYL]
PROPANOYL}-4-SUBSTITUTED THIOSEMICARBAZIDES
AND THEIR PRODUCTS OF CYCLIZATION TO
1,2,4-TRIAZOLE RING
Nazar Trotsko,1 Monika Wujec,1 Urszula Kosikowska,2
and Anna Malm2
1Department of Organic Chemistry, Faculty of Pharmacy, Medical University, 4A
Chodz´ki, 20-093, Lublin, Poland
2Department of Pharmaceutical Microbiology, Faculty of Pharmacy, Medical
University, 1 Chodz´ki, 20-093, Lublin, Poland
GRAPHICAL ABSTRACT
S
R
NH
S
NH
NH
O
O
2-5
2% NaOH
N
NH
S
N
R
O
S
6-9
Abstract By the reaction of 3-[(furan-2-ylmethyl)sulfanyl]propanoylhydrazide with
various isothiocyanates, the corresponding 4-substituted 1-[(furan-2-ylmethyl)sulfanyl]
propanoylthiosemicarbazide derivatives (2–5) were obtained. Thiosemicarbazide derivatives
(2–5) by ring closure with 2% NaOH, provided 5-{2-[(furan-2-ylmethyl)sulfanyl]ethyl}-4-
substituted-2,4-dihydro-3H-1,2,4-triazole-3-thiones (6–9). The new compounds were tested
for their in vitro antimicrobial activity. Compounds 2, 3, and 6 had in vitro activity against
Gram-positive reference strains of bacteria with MIC values: 250–500 μg/mL (for compound
2), 125–250 μg/mL (for compound 3), 500–1000 μg/mL (for compound 6).
[Supplementary materials are available for this article. Go to the publisher’s online edition of
Phosphorus, Sulfer, and Silicon and the Related Elements for the following free supplemental
files: Additional tables.]
Keywords Furan derivatives; 1,2,4-triazole ring; antimicrobial activity
Received 15 March 2013; accepted 24 June 2013.
Address correspondence to Nazar Trotsko, Department of Organic Chemistry, Faculty of Pharmacy, Medical
University in Lublin, 4A Chodz´ki Str., 20-093, Lublin, Poland. E-mail: nazar.trotsko@umlub.pl
293

294
N. TROTSKO ET AL.
INTRODUCTION
1,2,4-Triazoles are building blocks for many drugs such as Alprazolam, Estazolam,
Fluconazole, and Vibunazole. Depending of the nature of substitutents, the 1,2,4-triazole
derivatives can show various biological activities, such as analgesic,1 anti-inflammatory,2
anticancer,3 antibacterial, 4,5 and antiviral properties.6 In addition; 1,2,4-triazole-3-thiones
derivatives with a furan ring have been reported as antibacterial,7,8 antifungal,9 antinoci-
ceptive, 10 and plant-growth regulative substances.11 Besides, many drugs include a furan
ring, such as Ranitidine (histamine H2-receptor antagonist), and are used in the treatment of
peptic ulcer disease;12 Nitrofurazone, Nitrofurantoin, Furazolidone, Nifurtoinol, Nifurzide,
and Nifuratel are used as antimicrobial drugs.13 The design of new compounds contains the
modification of molecules by the combinations of different pharmacophores in one frame,
which may lead to the formation of new compounds with higher biological activity. In
view of these facts and in continuation of our earlier research on antimicrobial activity of
thiosemicarbazide and 1,2,4-triazole derivatives,14 we connected a furan ring with 1,2,4-
triazole heterocyclic systems that could help to increase the biological activity. The newly
synthesized compounds were tested for their in vitro antimicrobial activity.
RESULT AND DISCUSSION
Chemistry
In the present study, 3-[(furan-2-ylmethyl)sulfanyl]propanoylhydrazide (1) was
used as a starting material. This hydrazide was obtained by the reaction of ethyl ester
of 3-[(furan-2-ylmethyl)sulfanyl]propanoic acid with hydrazine hydrate by the method
described earlier.15 The reaction of 3-[(furan-2-ylmethyl)sulfanyl]propanoylhydrazide
with various isothiocyanates yield the corresponding 4-substituted 1-[(furan-2-ylmethyl)
sulfanyl]propanoylthiosemicarbazide derivatives (2–5). Ring closure with 2% NaOH
provided 5-{2-[(furan-2-ylmethyl)sulfanyl]ethyl}-4-substituted-2,4-dihydro-3H-1,2,4-tri-
azole-3-thiones (6–9). The reaction proceeded according to the Figure 1.
The structures of the newly synthesized compounds (2–9) were confirmed by ele-
mental analysis, IR, 1H NMR, and 13C NMR methods.
NH
S
NH2
O
O
RNCS
1
S
2% NaOH
NH
N
NHR
S
NH
S
NH
S
O
O
O
N
2-5
6-9
R
R=C6H5, 4-CH3-C6H4, C6H5CH2, C6H11
Figure 1 Synthesis of 1-[(furan-2-ylmethyl)sulfanyl]propanoyl-4-substituted thiosemicarbazide derivatives and
reaction of their cyclization.

ANTIMICROBIAL STUDY OF THIOSEMICARBAZIDES & 1,2,4-TRIAZOLES
295
In the IR spectra, absorption bands characteristic for fragments: C=O for compounds
(2–5) and C=S for compounds (2–9) are visible in the ranges of: 1675–1693 cm−1 and
1310–1340 cm−1, respectively.
In the 1H NMR spectra, all the compounds showed proton signals typical for furan
ring in the range of 6.13–7.58 ppm. For the thiosemicarbazides (2–5), the signals of proton
linked to nitrogens were shown at 7.26–9.99 ppm. Cyclic compounds (6–9) showed proton
signals in the range 13.52–13.75 ppm, that is typical for the NH group of the 1,2,4-triazole
ring.
The δ values of the carbons of the furan ring were in the range 107.6–107.7,
110.5–110.6, 142.4–142.5, and 151.2–151.6 ppm. In the thiosemicarbazide derivatives
(2–5), the signals of C=S and C=O groups were observed in the range 170.1–170.3 and
180.7–180.8 ppm, respectively. All the 1,2,4-triazole derivatives (6–9) showed the carbon
signals of C=S group in the range 166.1–167.7 ppm.
1
The detailed results of IR, H NMR, and 13C NMR spectra are presented in the
experimental part.
Microbiology
The results of antibacterial in vitro activity of the newly synthesized compounds
obtained using the agar dilution method did not show very significant effects against
most of the examined microorganisms. It was found that the tested compounds were not
active against Gram-negative bacteria and due majority of Gram-positive bacteria. Only
compounds 2, 3 with phenyl and 4-methylphenyl substituent respectively and 6 with phenyl
substituent showed moderate activity against Gram-positive bacteria with MIC values from
125 to 1000 μg/mL (Table S1 Supplemental Materials). The most sensitive bacteria was B.
subtilis. Three compounds had bactericidal effect toward this bacteria strain (MBC/MIC =
1 or 2).
Compounds 2 and 3 showed promising activity against Micrococcus luteus with MIC
250 and 125, respectively. But, on the basis of MBC/MIC ratio, it was found that these
compounds have bacteriostatic effect (MBC/MIC = 4 or 8).
EXPERIMENTAL
Chemistry
Melting points were determined in a Fischer-Johns block (Sanyo, Japan) and are
not corrected. The IR spectra were recorded in KBr using a Thermo Nicolet 6700 FT-IR
spectrometer. The 1H NMR and 13C NMR spectra were recorded on a Bruker Avance DPX
250, in DMSO-d6, using tetramethylsilane as internal standard. The purity of all compounds
was checked by TLC on aluminium oxide 60 F254 plates (Merck), in a CHCl3/C2H5OH
(10:1, v/v) solvent system with UV visualization (λ = 254 nm). Elemental microanalysis
for C, H, N was performed on AMZ 851 CHX analyzer and the results were within 0.4%
of theoretical values.
Synthesis of 1-{3-[(furan-2-ylmethyl)sulfanyl]propanoyl}-4-substituted
Thiosemicarbazides (2–5)
General procedure. To 3-[(furan-2-ylmethyl)sulfanyl]propanoylhydrazide 0.005
mol, corresponding isothiocyanate (phenyl isothiocyanate, 4-methylphenyl isothiocyanate,
benzyl isothiocyanate and cyclohexyl isothiocyanate) 0.005 mol was added. Then the

296
N. TROTSKO ET AL.
mixture was heated in an oil bath at 60◦C for 12 h. The obtained products were washed
with diethyl ether, dried, and recrystallized from ethanol.
1-{3-[(furan-2-ylmethyl)sulfanyl]propanoyl}-4-phenylthiosemicarbazide
(2)
Yield 60%, mp 104–106◦C. IR (KBr) ν(cm−1): 3229 (NH); 3136 (CHar.); 2958
1
(CHal.); 1689 (C=O); 1327 (C=S). H NMR (DMSO-d6) δ (ppm): 2.44, 2.69 (2m, 4H,
CH2CH2S); 3.82 (s, 2H, CH2S); 6.29, 6.39 (2d, 2H, furan ring, J = 2.5 Hz); 7.29 (m, 5H,
C6H5); 7.58 (m, 1H, furan ring); 9.61, 9.91, 9.99 (3s, 3H, 3NH). 13C NMR (DMSO-d6) δ
(ppm): 26.2, 27.1, 33.2 (3CH2), 107.4, 110.4 (2C, furan ring), 127.8, 129.4, 129.7, 131.3
(4Car.), 142.4, 151.3 (2C, furan ring), 170.1 (C=S), 180.7 (C=O). Elemental anal. (%),
Calcd for C15H17N3O2S2 (335.44): C 53.71, H 5.11, N 12.53; Found: C 53.64, H 5.13, N
12.60
1-{3-[(furan-2-ylmethyl)sulfanyl]propanoyl}-4-(4-methylphenyl)
thiosemicarbazide (3)
Yield 62%, mp 127–130◦C. IR (KBr) ν(cm−1): 3237 (NH); 3134 (CHar.); 2960
(CHal.); 1693 (C=O); 1325 (C=S). 1H NMR (DMSO-d6) δ (ppm): 2.27 (s, 3H, CH3); 2.42,
2.65 (2m 4H, CH2CH2S); 3.78 (s, 2H, CH2S); 6.28, 6.39 (2d, 2H, furan ring, J = 2.5 Hz);
7.12 (d, 2H, 4-CH3C6H4, J = 7.5 Hz); 7.27 (d, 2H, 4-CH3C6H4, J = 7.5 Hz); 7.57 (s, 1H,
furan ring); 9.40, 9.53, 9.96 (3s, 3H, 3NH). 13C NMR (DMSO-d6) δ (ppm): 20.5 (CH3),
26.4, 27.2, 33.5 (3CH2), 107.6, 110.6 (2C, furan ring), 125.3, 128.6, 134.3, 136.4 (4Car.),
142.5, 151.5 (2C, furan ring), 170.3 (C=S), 180.8 (C=O). Elemental anal. (%), Calcd for
C16H19N3O2S2 (349.47): C 54.99, H 5.48, N 12.02; Found: C 54.82, H 5.45, N 12.00
4-benzyl-1-{3-[(furan-2-ylmethyl)sulfanyl]propanoyl}thiosemicarbazide
(4)
Yield 58%, mp 90–93◦C. IR (KBr) ν(cm−1): 3236 (NH); 3133 (CHar.); 2949 (CHal.);
1690 (C=O); 1322 (C=S). 1H NMR (DMSO-d6) δ (ppm): 2.40, 2.64 (2m, 4H, CH2CH2S);
3.73 (s, 2H, CH2S); 4.27 (s, 2H, CH2C6H5); 6.26 (d,1H, furan ring, J = 3.1 Hz); 6.37 (m,
1H, furan ring); 7.21 (m, 5H, C6H5); 7.56 (m, 1H, furan ring); 8.32, 9.23, 9.83 (3s, 3H,
3NH). 13C NMR (DMSO-d6) δ (ppm): 25.3, 26.4, 27.0, 46.2 (4CH2), 107.6, 110.5 (2C,
furan ring), 126.3, 127.6, 128.5, 135.1 (4Car.), 142.5 (C, furan ring), 151.4 (C, furan ring),
170.2 (C=S) 180.6 (C=O). Elemental anal. (%), Calcd for C16H19N3O2S2 (349.47): C
54.99, H 5.48, N 12.02; Found: C 54.87, H 5.51, N 11.98
4-cyclohexyl-1-{3-[(furan-2-ylmethyl)sulfanyl]propanoyl}
thiosemicarbazide (5)
Yield 52%, mp 116–118◦C. IR (KBr) ν(cm−1): 3240 (NH); 3136 (CHar.); 2929, 2852
1
(CHal.); 1675 (C=O); 1333 (C=S). H NMR (DMSO-d6) δ (ppm): 1.20, 1.67 (2m, 10H,
cyclohexyl); 2.41, 2.68 (2m, 4H, CH2CH2S); 3.81 (s, 2H, CH2S); 4.02 (s, 1H, cyclohexyl);
6.28 (d, 1H, furan ring, J = 3.2 Hz); 6.38, 7.58 (2m, 2H, furan ring); 7.26, 9.16, 9.76 (3s,
3H, 3NH). 13C NMR (DMSO-d6) δ (ppm): 24.6, 24.8 (2CH2, cyclohexyl), 25.0, 26.7, 27.0
(3CH2), 31.6, 52.6 (2CH2, cyclohexyl), 107.7, 110.6, 142.5, 151.3 (4C, furan ring), 170.0

ANTIMICROBIAL STUDY OF THIOSEMICARBAZIDES & 1,2,4-TRIAZOLES
297
(C=S), 180.7 (C=O). Elemental anal. (%), Calcd for C15H23N3O2S2 (341.49): C 52.76, H
6.79, N 12.31; Found: C 52.82, H 6.71, N 12.27
Synthesis of 5-{2-[(furan-2-ylmethyl)sulfanyl]ethyl}-4-substituted-2,4-
dihydro-3H-1,2,4-triazole-3-thiones (6–9)
General procedure. To compounds 2–5 0.005 mol 2% solution of NaOH 10 mL
was added. The mixture was refluxed for 2 h. The solution was filtered off. After cooling
filtrate was acidified by diluted HCl to pH = 3–4. The resulting precipitate was recrystallized
from ethanol.
5-{2-[(furan-2-ylmethyl)sulfanyl]ethyl}-4-phenyl-2,4-dihydro-3H-1,2,4-
triazole-3-thione (6)
Yield 57%, mp 118–120◦C. IR (KBr) ν(cm−1): 3090, 3040 (CHar.); 2923 (CHal.);
1340 (C=S). 1H NMR (DMSO-d6) δ (ppm): 2.65 (m, 4H, CH2CH2S); 3.67 (s, 2H, CH2S);
6.15, 6.33 (2m, 2H, furan ring); 7.51 (dd, 1H, furan ring, J = 1.8 Hz, J = 0.8 Hz); 7.38,
7.56 (2m, 5H, C6H5); 13.75 (s, 1H, NH). 13C NMR (DMSO-d6) δ (ppm): 26.0, 27.0, 27.2
(3CH2); 107.6, 110.5 (2C, furan ring), 128.2, 129.5, 129.6, 133.5 (4Car.), 142.5 (C, furan
ring), 150.8 (C=N), 151.2 (C, furan ring), 167.7 (C=S). Elemental anal. (%), Calcd for
C15H15N3OS2 (317.43): C 56.76, H 4.76, N 13.24; Found: C 56.68, H 4.69, N 13.25
5-{2-[(furan-2-ylmethyl)sulfanyl]ethyl}-4-(4-methylphenyl)-2,4-dihydro-
3H-1,2,4-triazole-3-thione (7)
Yield 78%, mp 110–112◦C. IR (KBr) ν(cm−1): 3112, 3055 (CHar.); 2947 (CHal.); 1318
(C=S). 1H NMR (DMSO-d6) δ (ppm): 2.38 s (3H, CH3); 2.58, 2.63 (2m, 4H, CH2CH2S);
3.67 (s, 2H, CH2S); 6.14 (dd, 1H, furan ring, J = 3.2 Hz, J = 0.8 Hz); 6.33 (dd, 1H, furan
ring, J = 3.2 Hz, J = 1.9 Hz); 7.24, 7.35 (dd, 4H, 4-CH3C6H4, J = 7.5 Hz); 7.51 (dd, 1H,
furan ring, J = 1.9 Hz, J = 0.9 Hz); 13.71 s (1H, NH). 13C NMR (DMSO-d6) δ (ppm):20.8
(CH3), 26.0, 27.1, 27.2 (3CH2), 107.6, 110.5 (2C, furan ring), 127.9, 130.0, 130.9, 139.2
(4Car.), 142.5 (C, furan ring), 150.9 (C=N), 151.2 (C, furan ring), 167.7 (C=S). Elemental
anal. (%), Calcd for C16H17N3OS2 (331.46): C 57.98, H 5.17, N 12.68; Found: C 58.04, H
5.09, N 12.61
4-benzyl-5-{2-[(furan-2-ylmethyl)sulfanyl]ethyl}-2,4-dihydro-3H-1,2,4-
triazole-3-thione (8)
Yield 70%, mp 138–140◦C. IR (KBr) ν(cm−1): 3090, 3033 (CHar.); 2925 (CHal.);
1310 (C=S). 1H NMR (DMSO-d6) δ (ppm): 2.64 (m, 4H, CH2CH2S); 3.68 (s, 2H, CH2S);
5.19 (s, 2H, CH2C6H5); 6.13, 6.28 (2s, 2H, furan ring); 7.25 (m, 5H, C6H5); 7.46 (s, 1H,
furan ring); 13.72 (s, 1H, NH). 13C NMR (DMSO-d6) δ (ppm): 25.7, 26.8, 27.1, 45.5
(4CH2), 107.6, 110.5 (2C, furan ring), 126.9, 127.8, 128.7, 135.6 (4Car.), 142.5 (C, furan
ring), 151.1 (C=N), 151.3 (C, furan ring), 167.3 (C=S). Elemental anal. (%), Calcd for
C16H17N3OS2 (331.46): C 57.98, H 5.17, N 12.68; Found: C 58.11, H 5.21, N 12.71.

298
N. TROTSKO ET AL.
4-cyclohexyl-5-{2-[(furan-2-ylmethyl)sulfanyl]ethyl}-2,4-dihydro-3H-1,2,
4-triazole-3-thione (9)
Yield 85%, mp 126–127◦C. IR (KBr) ν(cm−1): 3110, 3046 (CHar.); 2932, 2855
1
(CHal.); 1322 (C=S). H NMR (DMSO-d6) δ (ppm): 1.26, 1.71 (2m, 10H, cyclohexyl);
2.81, 2.95 (2m, 4H, CH2CH2S); 3.83 (s, 2H, CH2S); 4.39 (s, 1H, cyclohexyl); 6.29, 6.38,
7.57 (3m, 3H, furan ring); 13.52 (s, 1H, NH). 13C NMR (DMSO-d6) δ (ppm): 24.5, 25.5
(2CH2, cyclohexyl), 26.7, 27.5, 27.6 (3CH2), 29.1, 55.6 (2CH2, cyclohexyl), 107.7, 110.6,
142.5 (3C, furan ring), 150.7 (C=N), 151.7 (C, furan ring), 166.1 (C=S). Elemental anal.
(%), Calcd for C15H21N3OS2 (323.48): C 55.70, H 6.54, N 12.99; Found: C 55.57, H 6.48,
N 13.08.
Microbiology
The antimicrobial activity of the tested 2–9 compounds was screened on the American
Type Culture Collection (ATCC) reference strains of the Gram-positive bacteria (Staphy-
lococcus aureus ATCC 25923, Staphylococcus epidermidis ATCC 12228, Bacillus subtilis
ATCC 6633, Micrococcus luteus ATCC 10240) and of the Gram-negative bacteria (Es-
cherichia coli ATCC 25922, Klebsiella pneumoniae ATCC 13883, Proteus mirabilis ATCC
12453, Pseudomonas aeruginosa ATCC 9027).
The methicillin-resistant Staphylococcus aureus (MRSA) Microbank 14.001 from the
collection of National Medicines Institute in Warsaw was used. All stock solutions of the
tested compounds were dissolved in dimethyl sulfoxide (DMSO). Microbial suspensions
were prepared in the sterile saline (0.85% NaCl) with an optical density of 0.5 McFarland
standard—150 × 106 CFU/mL (CFU—colony forming units). The medium with DMSO
at the final concentration and without the tested compounds served as a negative control.
In the first step, the antibacterial potency of tested compounds was screened using the agar
dilution method on the basis of the growth inhibition on the Mueller–Hinton agar to which
the tested compounds at concentrations 1000 μg/mL were added.
Then the antibacterial activity of the compounds with inhibitory effect was determined
by broth microdilution technique using 96-well microplates with series of twofold dilution
of the tested compounds, according to the method described earlier.14
It was shown that DMSO at the final concentration had no influence on the growth of
tested microorganisms. Cefuroxime was used as reference antibiotic. The antimicrobial ac-
tivity of the tested derivatives was expressed as the minimal concentration of the compound
that inhibits the visible growth of the bacteria (MIC). The MBC (minimal bactericidal con-
centration), defined as the lowest concentration of each compound that resulted in >99.9%
reduction in CFU of the initial inoculum, was also determined. MBC was determined by
a broth microdilution technique by plating out the contents of wells (5 μL) that showed
no visible growth of bacteria, onto Mueller–Hinton agar plates and incubating at 35◦C for
18 h.
REFERENCES
1. Tozkoparan, B.; Ku¨peli, E.; Yes¸ilada, E.; Ertan, M. Bioorg. Med. Chem. 2007, 15, 1808-1814.
2. Kumar, H.; Javed, S. A.; Khan, S. A.; Amir, M. Eur. J. Med. Chem. 2008, 43, 2688-2698.
3. Mavrova, A. Ts.; Wesselinova, D.; Tsenov, Y. A.; Denkova, P. Eur. J. Med. Chem. 2009, 44,
63-69.

ANTIMICROBIAL STUDY OF THIOSEMICARBAZIDES & 1,2,4-TRIAZOLES
299
4. Bayrak, H.; Demirbas, A.; Karaoglu, S. A.; Demirbas, N. Eur. J. Med. Chem. 2009, 44, 1057-
1066.
5. Almajan, G. L.; Barbuceanu, S. -F.; Almajan, E. -R.; Draghici, C.; Saramet, G. Eur. J. Med.
Chem. 2009, 44, 3083-3089.
6. Kritsanida, M.; Mouroutsou, A.; Marakos, P.; Pouli, N.; Papakonstantinou-Garoufalias, S.; Pan-
necouque, C.; Witvrouw, M.; De Clerq, E. Farmaco 2002, 57, 253-257.
7. Shehata, I. A. Saudi Pharm. J. 2003, 11, 87-96.
8. Siwek, A.; Wujec, M.; Stefan´ska, J.; Paneth, P. Phosphorus Sulfur Silicon Relat. Elem. 2009,
184, 3149-3159.
9. Klip, N. T.; C¸ apan, G.; Gu¨rsoy, A.; Uzun, M.; Satana, D. J. Enzym. Inhib. Med. Chem. 2010, 25,
126-131.
10. Siwek, A.; Wujec, M.; Dobosz, M.; Jagiełło-Wo´jtowicz, E.; Chodkowska, A.; Kleinrok, A.;
Paneth, P. Cent. Eur. J. Chem. 2008, 6, 47-53.
11. Li, X. Z.; Si, Z. X. Chinese Chem. Lett. 2002, 13, 129-132.
12. Woodings, E. P.; Dixon, G. T.; Harrison, C.; Carey, P.; Richards, D. A. Gut. 1980, 21, 187-191.
13. Podlewski, J.; Chwalibogowska-Podlewska, A. Leki Wspo´łczesnej Terapii (Drugs of Contempo-
rary Therapy); PZWL: Warszawa, 1986; pp. 275, 422-423, 425.
14. Trotsko, N.; Kro´l, J.; Siwek, A.; Wujec, M.; Kosikowska, U.; Malm, A. Heteroatom Chem. 2012,
23, 117-121.
15. Hallinan, E. A.; Hagen, T. J.; Husa, R. K.; Tsymbalov, S.; Lee, A. C.; Van Hoeck, J-P. Eur. Pat.
Appl. 1992, EP 0512400 A1, 92/46, pp. 61.