Synthesis and spectroscopic characterization of fluorescent 4-aminoantipyrine analogues: Molecular docking and in vitro cytotoxicity studies

Article abstract of DOI:10.1016/j.saa.2015.08.008

Two substituted aromatic carbonyl compounds (compounds 1 and 2) of 4-aminoantipyrine were synthesized by condensation of fluorine substituted benzoyl chlorides and 4-aminoantipyrine. The structures of synthesized derivatives were established on the basis of UV-Vis, IR, and Mass, ¹H, ¹³C NMR and Fluorescence spectroscopy. Both compounds showed significant fluorescence emission and two broad emission bands were observed in the region at 340 nm and 450 nm on excitation at 280 nm. Theoretically to prove that the molecule has anticancer activity against cervical cancer cells, the compounds were analyzed for molecular docking interactions with HPV16-E7 target protein by Glide protocol. Furthermore, 4-aminoantipyrine derivatives were evaluated for their in vitro cytotoxic activity against human cervical cancer cells (SiHa) by MTT assay. Compound 1 showed two fold higher activity (IC₅₀ = 0.912 μM) over compound 2, and its activity was similar to that of Pazopanib, suggesting that although the two compounds were chemically very similar the difference in substituent on the phenyl moiety caused changes in properties.

Full text of DOI:10.1016/j.saa.2015.08.008

Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy 153 (2015) 118–123
Contents lists available at ScienceDirect
Spectrochimica Acta Part A: Molecular and Biomolecular
Spectroscopy
journal homepage: www.elsevier.com/locate/saa
Synthesis and spectroscopic characterization of fluorescent
4-aminoantipyrine analogues: Molecular docking and in vitro
cytotoxicity studies
c
c
c
b
a
D. Premnath a, , P. Mosae Selvakumar , P. Ravichandiran , G. Tamil Selvan , M. Indiraleka , J. Jannet Vennila
⁎
a
Department of Bioinformatics, School of Biotechnology and Health Science, Karunya University, Coimbatore 641114, Tamilnadu, India
Department of Bio Technology, Mepco Schlenk Engineering College, Sivakasi, Tamilnadu, India
Department of Chemistry, School of Science and Humanities, Karunya University, Coimbatore 641114, Tamilnadu, India
b
c
a r t i c l e i n f o
a b s t r a c t
Article history:
Two substituted aromatic carbonyl compounds (compounds 1 and 2) of 4-aminoantipyrine were synthesized by
condensation of fluorine substituted benzoyl chlorides and 4-aminoantipyrine. The structures of synthesized
derivatives were established on the basis of UV–Vis, IR, and Mass, 1H, 13C NMR and Fluorescence spectroscopy.
Both compounds showed significant fluorescence emission and two broad emission bands were observed in
the region at 340 nm and 450 nm on excitation at 280 nm. Theoretically to prove that the molecule has anticancer
activity against cervical cancer cells, the compounds were analyzed for molecular docking interactions with
HPV16-E7 target protein by Glide protocol. Furthermore, 4-aminoantipyrine derivatives were evaluated for
their in vitro cytotoxic activity against human cervical cancer cells (SiHa) by MTT assay. Compound 1 showed
two fold higher activity (IC50 = 0.912 μM) over compound 2, and its activity was similar to that of Pazopanib,
suggesting that although the two compounds were chemically very similar the difference in substituent on the
phenyl moiety caused changes in properties.
Received 9 February 2015
Received in revised form 23 July 2015
Accepted 4 August 2015
Available online 10 August 2015
Keywords:
4-Aminoantipyridine
Fluorescence
Spectroscopy
Molecular docking
Cytotoxic activity
© 2015 Elsevier B.V. All rights reserved.
1. Introduction
derivatives [12].4-Aminoantipyrine has been utilized as a key interme-
diate for the synthesis of heterocycles bearing biologically active moie-
4-Aminoantipyrine and its derivatives are recognized for their vari-
ety of applications in the area of catalysis [1,2], medicine [3], and phar-
macology [4]. Understanding the factors that promote drug innovation
is important both for improvements in health care and for the future
of organizations engaged in drug discovery research and development.
New kinds of chemo-therapeutic agents containing Schiff bases have
gained significant attention among the biochemists [1] and some of
the aminopyrines are commonly administered intravenously to detect
liver disease [3] in clinical treatment. New kinds of Schiff base
compounds containing 4-aminoantipyrine have gained significant in-
terest due to their potential applications in the area of catalysis [5–7]
medicine [8] and pharmacology [9,10]. To probe the functional and
application properties in chemotherapy diagnostic center a variety of
4-aminoantipyrine based agents are commonly administered intrave-
nously to detect liver disease in clinical treatment [11]. Due to their sig-
nificant roles in the environment, industrial and biological processes,
research efforts have been devoted towards the design and develop-
ment of simple and sensitive chromo sensors using 4-aminoantipyrine
ties [13–15]. 4-Aminoantipyrine administration caused a significant
decrease in the contracture of myometrium, while the cervix did not
reveal significant change [16]. Binding studies of 4-aminoantipyrine
with human serum albumin and DNA have already been explored
[17,18]. 4-Aminoantipyrine derivatives are well recognized for their
clinical and sensor abilities, however no attempt has been made to in-
vestigate their anticancer activity against cervical cancer. Furthermore,
4-aminoantipyrine aromatic acid derivatives have been studied less
extensively with regard to anti-viral effects in viral infections that can
subsequently lead to carcinomas. This study thus aims at assessing the
effectiveness and plausible mode of action of compounds belonging to
the class of 4AAP derivatives in HPV positive cervical cancer cells. As
an effective receptor to design target based drug design, we selectively
chose HPV16 E7 protein [18] and the designing and synthesizing of
4-aminoantipyrine derivatives became one of our major goals.
Towards this goal, this work reports the synthesis of two fluorescent
4-aminoantipyrine fluorine substituted benzoyl chloride derivatives,
with a special focus on their structural investigation, molecular docking
analysis with HPV16-E7 target protein receptor, and in vitro cytotoxicity
against human cervical cancer cells (SiHa). Spectroscopic analyses
explore the molecular structure and fluorescence of the compounds,
shown in Fig. 1.
⁎
Corresponding author.
E-mail address: prems.bioinfo@gmail.com (D. Premnath).
http://dx.doi.org/10.1016/j.saa.2015.08.008
1386-1425/© 2015 Elsevier B.V. All rights reserved.

D. Premnath et al. / Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy 153 (2015) 118–123
119
7.17 (tr, Ar, 2H), 3.11 (s, N–CH3, 3H), 2.20 (s, C–CH3, 3H). 13C-NMR: (δ,
DMSO-D6) 160 (C_O, amide), 155.95 (C_O), 135.69 134.75, 129.07,
126.82, 126.502, 124.00, 123.83, 103.83, 105.65 (aryl carbons) 105
(NH–C_) 35.71 (N–Me), 11.04 (C–Me). IR data (KBr, cm−1): 3140,
2937, 1950, 1800, 1697, 1633, 1514, 1425, 1365, 1321, 1240, 1133,
1100, 991, 962, 854, 804, 258, 700, 594. UV–Vis [DMSO,λmax,nm,],
263, 292. ES [MSI] calculated for C18H12F5N3O2 (m/z) = 397.30,
found = 397.13.
2.2.1.1. Analytical data. Calculated for C18H12F5N3O2. Calc: C, 54.42; H,
3.04; N, 10.58%. Found: C, 54.22; H, 3.09; N, 10.65%.
2.2.2. Synthesis of compound 2
1:1 equimolar methanolic solution of 4-aminoantipyrine (0.203 g,
0.001 mol) and 2, 6-Difluorobenzoyl chloride (0.176 g, 0.001 mol)
were mixed and refluxed for 90 min with constant stirring. The pale yel-
low precipitate obtained by condensation was filtered out and
recrystallized in methanol.
Fig. 1. Molecular structures of 4-aminoantipyridine derivatives 1 and 2.
2. Experimental section
2.1. Materials
4-Aminoantipyrine, 4-methylbenzoyl chloride, 3-methylbenzoyl
chloride, and plasmid DNA were purchased from Aldrich & Co. SiHa cer-
vical cancer cell line was purchased from NCCS, Pune INDIA. All cells
were grown in 10% DMEM at 37 °C in 5% CO2. Commercially available
MTT (3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide)
and Eagle's minimal essential medium (EMEM) were obtained from
Sigma (St Louis, MO). Caspase-3 apoptosis kit was purchased from BD
Pharmingen, USA. All other reagents and solvents were of analytical
grade.
N-(1, 5-dimethyl-3-oxo-2-phenyl-2, 3-dihydro-1H-pyrazol-4-yl)-2,
6-difluoro-benzamide. The same synthetic procedure adopted for com-
pound 1 was repeated for compound 2, appropriately adapting 2, 6-
difluorobenzoyl chloride in place of 1,2,3,4,5-pentafluorobenzoyl. NMR
data (δ, DMSO-D6): 9.91 (s, –NH, 1H), 7.56–7.49 (q, phenyl, 3H), 7.37–
7.31 (q, phenyl, 3H), 7.21–7.17 (tr, phenyl, 2H), 3.10 (s, N–CH3, 3H),
2.20 (s, C–CH3, 3H). 13C-NMR: (δ, DMSO-D6) 160.07 (C_O, amide),
159.12 (C_O), 152.27, 134.86, 131.75, 131.95, 129.09, 126.45, 123.77,
112.00, 111.95, 111.76, 106.27 (aryl carbons) 106.27 (NH–C_) 35.82
(N–Me), 11.04 (C–Me), IR data (KBr, cm−1) 3508, 3444, 1662, 1625
1496, 1457, 1413, 1348, 1333, 1236, 1010, 906, 852, 796, 608, 530.
UV–Vis [DMSO, λmax, nm,], 260, 290. ES (MSI): Calculated for
C18H15F2N3O2 (m/z) = 343.33; Found = 343.15.
2.2. Synthesis
2.2.2.1. Anal data. Calculated for C18H15F2N3O2. Calc: C, 62.97; H, 4.40; N,
12.24%. Found: 62.68; H, 4.54; N, 12.07%.
2.2.1. Synthesis of compound 1
1:1 equimolar methanolic solution of 4-aminoantipyrine (0.203 g,
0.001 mol) and 1,2,3,4,5-pentafluorobenzoyl chloride (0.230 g,
0.001 mol) were mixed and refluxed for 90 min with constant stirring.
The pale yellow precipitate obtained by condensation was filtered out
and recrystallized in methanol.
N-(1, 5-dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol-4-yl)-
2,3,4,5,6-pentafluoro-benzamide. NMR data (δ, DMSO-D6): 10.19
(s, –NH, 1H), 7.53–7.49 (t, phenyl, 2H), 7.37–7.32 (q, phenyl, 3H), 7.21–
2.3. Physical measurements
Microanalysis of the complexes was done using a PerkinElmer PE
2400 series II CHNS/O elemental analyzer. Electronic spectra were re-
corded on a Jasco 670 spectrophotometer. Fluorescence spectra were
recorded on a Jasco 8300 spectrophotometer. 1H NMR spectroscopy in
DMSO-d6 (500 MHz, Bruker), 13C NMR spectroscopy in DMSO-d6
(125 MHz, Bruker) using tetramethylsilane (TMS) as internal standard
Scheme 1. Synthesis of 4-aminoantipyridine derivatives 1 and 2.

120
D. Premnath et al. / Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy 153 (2015) 118–123
accomplished using SP (Single precision) and XP (Extra precision)
docking procedure.
2.5. Biological assay
2.5.1. In vitro cytotoxicity analysis
In vitro cytotoxicity analysis was performed using standard proce-
dures available in previous reports [23–27]. SiHa cervical cancer cell
line was analyzed for contaminants. The contaminant free SiHa cells
was cultured in complete EMEM growth medium (EMEM + 10% FBS).
90% confluent SiHa mono layer culture was trypsinized and was diluted
with complete growth medium. 10,000 cells were placed in each well of
a 96-well plate, and the plate was incubated in a CO2 incubator for 24 h
at 37 °C. The medium was then aspirated out and 95 μl of fresh medium
and 5 μl of drug was added. The plate was incubated in CO2 incubator for
48 h at 37 °C. 20 μl medium was removed and replaced with 20 μl MTT.
The plate was incubated in CO2 incubator for 4 to 6 h at 37 °C. The entire
medium was carefully removed and the formazan crystals were
dissolved in DMSO. The plate was read at 570 nm. The % growth
inhibition was calculated by % cell inhibition = 100 − ({(At − Ab) /
(Ac − Ab)} × 100), where, At — absorbance value of test compound.
Ab — absorbance value of blank, and Ac — absorbance value of control.
Fig. 2. UV–Visible spectrum of compounds 1 and 2 in ethanol (inset: fluorescence emission
spectrum of compound 1 and 2 excited at 290 nm).
were also carried out. Chemical shifts for proton resonances are report-
ed in ppm (δ) relative to tetramethylesilane and DMSO-D6 was used as
solvent. High-resolution mass spectra (HRMS-EI) was measured by
Electron ionization (EI) method (Jeol GC-Mate 2). Molecular docking
studies of all the synthesized compounds were accomplished by
GLIDE program (version 8.5, Schrodinger, LLC, New York, 2010) and
the entire glide scores are reported in kcal/mol. In vitro cytotoxicity of
all the compounds against cervical cancer cell line (SiHa) was studied
by cell viability assay method.
3. Results and discussion
3.1. Synthesis
The 4-antiaminopyrine derivatives 1 and 2, possessing fluorine
substituted phenyl moiety, were synthesized by acid chloride and
amine condensation reaction in acetone at 40 °C as represented in
Scheme 1.
The compounds 1 and 2 are pale yellow in color and are soluble in
almost all organic solvents, such as acetone, methanol, acetonitrile,
chloroform, DMF, and DMSO.
2.4. Molecular docking studies
Molecular docking has become an increasingly important tool for
drug discovery. It is a useful tool for investigating the binding interac-
tion of a protein receptor with its ligand and detail about the binding
mechanism. Flexible ligand with rigid receptor docking strategies
were employed in this study to identify the most suitable ligand binging
sites in the compounds 1 and 2 with human papilloma virus type 16 E7
protein [19,20]. To prove the biological activity through computational
method the protein molecule should have the three dimensional molec-
ular characterization and in view of the study the three dimensional
structure of E7 protein was predicted and downloaded through Robetta
server. Molecular docking studies were performed using Schrödinger
Glide program (version version 2014-4, Schrödinger LLC, New York
2014) [21]. To perceive the docking glide score results Maestro user in-
terface was executed and to confirm the best docking and validate the
docking score, the protocol was evaluated by re-docking. To compare
the molecular interaction with the standard reference drug, Pazopanib
[22] was selected for docking studies. The structures of compounds 1,
2, and the reference molecule were drawn using ACD/Chemsketch
(free ware). The Glide Grid generation wizard was used to define the
grid space to reveal the biological active site. Glide docking was
3.2. Spectral investigation
3.2.1. UV–Vis spectroscopy
The UV–Visible spectrum for compounds 1 and 2 were recorded
in ethanol. Both compounds exhibited similar absorption spectra
(Fig. 2).with two bands, one at 260 nm (π–π* transition) and the
other at 290 nm (n–π* transition). The later is due to non-bonding
electrons present on the nitrogen atom of the CO group [28].
3.2.2. Fluorescence spectra
Fluorescence emission spectra of compounds 1 and 2 were recorded
in 10−5 M solution of ethanol at room temperature (Fig. 2). Emission
band observed region at 320 nm when excited at 280 nm. Both
compounds behave similarly due to the 4-aminoantipyrine core which
is common.
3.2.3. IR spectra
FT-IR spectra of compounds 1 and 2 were recorded to identify func-
tional groups [Supplementary material S1-1]. The three characteristic IR
signals for compounds 1 and 2 corresponding to (i) CO, (ii) NH, and
Fig. 3. Optimized geometry of compounds 1 and 2.

D. Premnath et al. / Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy 153 (2015) 118–123
121
(iii) C–N were analyzed. The broad IR signal around 3800–3000 cm−1
obtained for both compounds 1 and 2 can be ascribed to the NH func-
tional groups. Compounds 1 & 2 showing sharp and intense peaks in
the range of 1572–1589 cm−1 and 1616–1665 cm−1 can be attributed
to νC–N and νC_O stretching modes respectively.
3.2.4. Mass spectra
The mass spectral data [Supplementary material SI-2, 3] indicating
an intense molecular ion peak at 343.17 and 394.13 corresponds to
respective (M + 1) molecular formulae, confirming the formation of
compounds 1 and 2 respectively.
3.2.5. NMR spectra
1H and 13C-NMR spectroscopic techniques were carried out and the
compounds were characterized without any ambiguity as described
below. The 1H NMR spectra recorded on DMSO-D6, (SI-4) independent-
ly provides well resolved 1H NMR signals attributable to aliphatic
protons N–CH3 and C–CH3, in addition to aromatic phenyl protons,
and NH resonances and the integral area matches with the calculated
number of hydrogens appropriately.
The 13C NMR spectra (SI-5) recorded in CDCl3 provides many well
distinguishable peaks confirming the presence of various magnetically
nonequivalent carbons. The peaks around 160 and 155δ indicate the
presence of two different C_O groups attributed to antipyrine CO and
peptide CO. In the aromatic region, the peak corresponding to 131.37
and 131.57δ with a weak intensity represents the quaternary carbon.
The other peaks observed at 129.83, 128.58, 128.49δ corresponds to
the aromatic CH carbons. The peak at 70.49δ indicates the presence of
–CH2, the 13C resonance at 35δ and 10δ represents the N–CH3 and
C–CH3 carbons respectivly.
3.2.6. Molecular docking studies
The optimized geometry of compounds 1 and 2 are shown in Fig. 3.
Both structures are almost similar. The fluorine substituted phenyl ring
is situated nearly perpendicular to the 4-aminoantipyrene ring.
To comprehend the molecular interaction of HPV16 E7 protein re-
ceptor with chemically synthesized molecules of compounds 1 and 2,
the three dimensional structure of HPV16 E7 protein was predicted
and downloaded from Robetta server [29] and deliberated with
Schrodinger GLIDE program. All Glide Docking and Emodel scores
were analyzed and the details are presented in Table 1. Aromatic car-
bonyl functional groups of both compounds were established. Before
docking, compounds 1 and 2 were optimized using Schrödinger soft-
ware to have proper atomic coordination. Docking studies revealed in-
termolecular hydrogen bonding interaction with amino hydrogens of
GLN70 of receptor protein and amide and antipyrine carbonyl groups
of compounds 1 and 2. The standard reference drug pazopanib
interacted through hydrogen bonding with GLN70, CYS68, ASP14, and
ASP4 (Fig. 4). All the Glide and Emodel scores were compared with
the scores of the standard drug. Computational analysis of the com-
pounds clearly reveal significant relationship of 4-aminoantipyrine
fluorinated benzoyl derivative with the HPV16 E7 receptor moieties,
suggesting that increasing the number of fluorine in benzoyl moiety
may increase the efficacy of the drug.
Fig. 4. Docking model structure of compounds 1, 2 and reference drug (Pazopanib) into
the HPV16 E7 Protein Binding Pocket.
Table 1
Molecular docking data of compounds 1, 2 and standard reference drug (Pazopanib) with
HPV16 E7 protein receptor.
Compounds Molecular docking
3.2.7. In vitro cytotoxicity assay
In vitro cytotoxicity was estimated using MTT assay. Results revealed
the anticancer efficacy of compounds 1 and 2 on human cervical cancer
cells (Fig. 5). Morphological alteration was obtained in all the tested
concentrations and the two compounds showed dose dependent
anticancer activity (Fig. 6). Maximum anticancer activities for both
compounds were observed at 100 μM. The percentage of cell growth
Glide score Emodel score Binding Energy XP hydrogen bond
(kcal/mol)
1.
2.
3.
−12.658
−12.073
−11.356
−58.79
−76.849
−38.717
−49.612
−64.731
−532.487
2 (GLN 70)
2 (GLN 70)
4 (GLN70, CYS 68,
ASP14, ASP4)

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D. Premnath et al. / Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy 153 (2015) 118–123
Fig. 5. Images of cytotoxic activity of compound 1 and 2 in SiHa cell line.
inhibition was found to be 93.02% for compound 1 and 85.27% for com-
pound 2. The IC50 values were estimated from Fig. 7, and was found to
be 0.912 μM for compound 1 and 1.02 μM for compound 2 and 0.8 μM
for Pazopanib, revealing that the potency of compound 1 was closer
to standard than compound 2. The higher anticancer potency of
compound 1 is probably due to the presence of high number of fluorine
in benzoyl moiety in the 4-aminoantipyrine. This might be the reason
for the notable difference in IC50 values of the synthesized 4-
aminoantipyrine derivatives (Fig. 8).
causing cervical cancer in human. In vitro cytotoxicity study of the
synthesized molecules against cervical cancer cells (SiHa), revealed
that compound 1 exhibited better IC50 value (0.912 μM) than com-
pound 2 (1.02 μM) and was similar to that of the standard drug.
Both compounds inhibited the growth of SiHa cells, with compound
1 showing a cell growth inhibition of 93.02% and compound 2
showing a cell growth inhibition of 85.27%. On comparing the re-
sults of Glide score and in vitro cytotoxicity studies, it is clear that
these two fluorine substituted fluorescent 4-aminoantipyrine deriv-
atives are moderately effective in inhibiting the growth of cancer
cells (SiHa). The difference in fluorine substitution on the phenyl
moiety exhibited changes in anticancer potency of the compounds,
even though both these compounds were derived from a common
structure.
4. Conclusion
In conclusion, a new series of fluorine substituted fluorescent 4-
aminoantipyrine derivatives were chosen through target based
drug discovery, and synthesized, and characterized by UV–Visible,
FT-IR, 1H NMR, 13C NMR and high resolution mass (HRMS-EI) spec-
troscopy. Compounds 1 and 2 showed significant fluorescence
emission, two broad emission bands were observed in the region
of 340 nm and 450 nm on excitation at 280 nm. Molecular docking
studies establish that these molecules exhibit significant molecular
interactions with HPV16-E7 target protein that are responsible for
Acknowledgment
The authors thank the management and the authorities of Karunya
University, Coimbatore, for their kind support in terms of providing
lab facility. We extend our thanks to SAIF, IIT Chennai, India and IISC
Bangalore, India for the NMR and HR-Mass spectral analyses.
Fig. 6. Determination of IC50 value of the compound by MTT assay.

D. Premnath et al. / Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy 153 (2015) 118–123
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Fig. 7. Anticancer effect of compounds 1 and 2 on SiHa cell line.
[7] V. Aruna, N. Sridevi, P.P. Robinsona, S. Manjua, K.K.M. Yusuff, Ni(II) and Ru(II) Schiff
base complexes as catalysts for the reduction of benzene, Journal of Molecular Catal-
ysis A: Chemical 304 (2009) 191–198.
[8] Claudia A. Contreras-Celedón, Darío Mendoza-Rayo, José A. Rincón-Medina, Luis
Chacón-García, novel 4-aminoantipyrine-Pd(II) complex catalyzes Suzuki–Miyaura
cross-coupling reactions of aryl halides, Beilstein J. Org. Chem. 10 (2014)
2821–2826.
[9] A.M. Farghaly, A. Hozza, Pharmazie 35 (1980) 596.
[10] T. Hitoshi, N. Tamao, A. Hideyuki, F. Manabu, M. Takayuki, Polyhedron 16 (1997)
3787.
[11] P.M. Selvakumar, E. Suresh, P.S. Subramanian, Polyhedron 26 (4) (2007) 749–756.
[12] Amendola et al., 2006; Gunnlaugsson et al. 2006; Katyav et al. 2006; Schmidtchen,
2006.
[13] M.M. Ghorab, M.G. El-Gazzar, M.S. Alsaid, Int. J. Mol. Sci. 15 (5) (2014) 7539–7553,
http://dx.doi.org/10.3390/ijms15057539.
[14] Samir Bondock, Ramy Rabie, Hassan A. Etman, Ahmed A. Fadda, Eur. J. Med. Chem.
43 (10) (October 2008) 2122–2129.
[15] Hala M. Aly, Nashwa M. Saleh, Heba A. Elhady, Eur. J. Med. Chem. 46 (9) (September
2011) 4566–4572.
[16] G. Yarrington, K. Fontwit, J.P. Figueroa, A. Massmann, P.W. Nathanielsz, Yale J. Biol.
Med. 59 (4) (1986) 415–424.
[17] Jayant I. Gowda, Sharanappa T. Nandibewoor, Spectrochim. Acta A Mol. Biomol.
Fig. 8. Analysis of IC50 values of compounds 1 and 2 on SiHa cells.
Spectrosc. 124 (2014) 397–403.
[18] N. Raman, A. Sakthivel, N. Pravin, Spectrochim. Acta A Mol. Biomol. Spectrosc. 125
(2014) 404–413.
[19] Noor Gammoh, Helena Sterlinko Grm, Paola Massimi, Lawrence Banks, J. Virol. 80
(4) (February 2006) 1787–1797.
Appendix A. Supplementary data
[20] A. Roman, K. Munger, Virology 445 (2013) 138–168.
[21] R.A.O. Friesner, R.B. Murphy, M.P. Repasky, L.L. Frye, J.R. Greenwood, T.A. Halgren,
P.C. Sanschagrin, D.T. Mainz, J. Med. Chem. 49 (2006) 6177–6196.
[22] Fabio A.B. Schutz, Toni K. Choueiri, Cora N. Sternberg, Crit. Rev. Oncol. Hematol. 77
(3) (Mar 2011) 163–171.
Supplementary data to this article can be found online at http://dx.
doi.org/10.1016/j.saa.2015.08.008.
[23] T. Mossman, J. Immunol. Methods 65 (1983) 55–63.
[24] B.C. Saravanan, C. Sreekumar, G.C. Bansal, D. Ray, J.R. Rao, A.K. Mishra, Vet. Parasitol.
113 (2003) 211–216.
[25] D.I. Bounous, R.P. Campagnoli, J. Brown, Avian Dis. 36 (1992) 1022–1027.
[26] J. Carmichael, W.G. DeGraff, A.F. Gazdar, J.D. Minna, J.B. Mitchell, Cancer Res. 47
(1987) 936–942.
[27] Wilson AP.,3rd ed, Oxford University Press: Oxford Vol. 1; 2000.
[28] S. Yousuf, R. Alex, P.M. Selvakumar, I.V.M.V. Enoch, P.S. Subramanian, Y. Sun, Picking
out logic operations in a naphthalene β-diketone derivative by using molecular
encapsulation, controlled protonation, and DNA binding, ChemistryOpen
(2015), http://dx.doi.org/10.1002/open.201500034.
[29] D.E. Kim, D. Chivian, D. Baker, Nucleic Acids Res. 32 (Web Server issue) (2004)
W526–W531.
References
[1] K. Bernardo, S. Leppard, A. Robert, G. Commenges, F. Dehan, B. Meunier, Inorg.
Chem. 35 (1996) 387.
[2] T. Punniyamurthy, S.J.S. Kalra, J. Iqbal, Tetrahedron Lett. 36 (1995) 8497.
[3] D. Chiaramonte, J.M. Steiner, J.D. Broussard, K. Baer, S. Gumminger, E.M. Moeller,
D.A. Williams, R. Shumway, Can. J. Vet. Res. 67 (2003) 183.
[4] T. Hitoshi, N. Tamao, A. Hideyuki, F. Manabu, M. Takayuki, Polyhedron 16 (1997)
3787.
[5] Kamal Z. Ismail, Transit. Met. Chem. 25 (2000) 522–528.
[6] C.A. Contreras-Celedón, J.A. Rincón-Medina, D. Mendoza-Rayo, L. Chacón-García,
Oxidative homocoupling of arylboronic acids catalyzed by a 4-aminoantipyrine–
Pd(II)complex, Appl. Organometal. Chem. 29 (2015) 439–442.