Preparation of 2-phenyl-3-hydroxyquinoline-4(1H)-one-5-carboxamides as potential anticancer and fluorescence agents

Article abstract of DOI:10.1039/c5ra08733c

The synthesis of 3-hydroxyquinoline-4(1H)-one derivatives bearing substituted phenyl in position 2 and variously substituted carboxamide group in position 5 is described, with use of 3-nitrophthalic anhydride, α-haloketones and primary amines as the starting materials. The synthetic approach was inspired by the preparation of analogous derivatives reported previously. However, a different strategy had to be developed with the corresponding bis(phenacyl)-3-aminophthalates as the key intermediates. Synthesized hydroxyquinolinones, as well as their intermediates, were tested for their cytotoxic activity towards various cancer and non-malignant cell lines. The fluorescent properties of these compounds have also been evaluated. In both fields, interesting data were obtained and compared to isomeric compounds that have been studied in the past.

Full text of DOI:10.1039/c5ra08733c

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Motyka, P. Dzubak, P. Znojek, S. Gurska, J. Kusz, C. McMaster, M. Hajduch and M. Soural, RSC Adv., 2015,
DOI: 10.1039/C5RA08733C.
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Preparation of 2-Phenyl-3-hydroxyquinoline-4(1H)-one-5-
carboxamides as Potential Anticancer and Fluorescence
Agents
Received 00th January 20xx,
Accepted 00th January 20xx
Petr Funka, Kamil Motykaa, Petr Džubákb, Pawel Znojekb, Sona Gurskab, Joachim Kuszc, Claire
DOI: 10.1039/x0xx00000x
McMastera, Marián Hajdúchb, and Miroslav Sourala
www.rsc.org/
Synthesis of 3-hydroxyquinoline-4(1H)-one derivatives bearing substituted phenyl in position 2 and variously substituted
carboxamide group in position 5 is described, with use of 3-nitrophthalic anhydride, α-haloketones and primary amines as
the starting materials. The synthetic approach was inspired by the preparation of analogous derivatives reported
previously. However, a different strategy had to be developed with the corresponding bis(phenacyl)-3-aminophthalates as
the key intermediates . Synthesized hydroxyquinolinones, as well as their intermediates, were tested for their cytotoxic
activity towards various cancer and non-malignant cell lines. The fluorescent properties of these compounds have also
been evaluated. In both fields, interesting data were obtained and compared to isomeric compounds that have been
studied
in
the
past.
prepared. Both structure-cytotoxicity20,21 and structure-
fluorescence22 relationships have been evaluated and
derivatives with the most promising biological and
fluorescence properties were identified (Figure 1).
Introduction
In the last decade, compounds bearing 3-hydroxyquinolin-
4(1H)-one scaffold (3HQs) have been studied intensively due
to their outstanding biological and spectral properties. In the
field of medicinal chemistry, 3HQs exhibited significant
cytotoxicity against selected cancer cell lines, indicating their
possible application as novel anticancer agents.1-5
Consequently, the most promising compounds have been
submitted for liposomal solubilization6 and micellar dispersion7
studies to increase their bioavailability and stability. Aside
from cytotoxicity, hydroxyquinolinones also exhibited strong
fluorescence with a dual emission spectra which pointed to
their potential application in the area of molecular probes and
fluorescence labeling.8-11 With use of the highly efficient
Pol = PS-DVB resin
L = backbone amide linker
O
O
O
O
OH
OH
R1
OH
H
N
H
N
L
N
R1
or
or
H
Pol
R1
N
H
N
H
R2
N
H
R2
R2
R1
O
N
O
H
O
O
O
H
N
R
OH
OH
O
N
R1
O
H
H
N
Cl
NH2
Cl
NH2
R
N
H
5
4
N
H
3
OH
O
6
2
Cl
Cl
7
N
R2
1
8
H
R: Cyclooctyl, IC =0.62-0.75 ꢀM, TI=17-43
R: Dodecyl, IC =0.25-0.56 ꢀM, TI=160-393
50
R: H, quantum yield 50.6%
R: pentyl, quantum yield 49.6%
50
R: Cyclododecyl, IC =0.26-0.77 ꢀM, TI= 47-217
R: hydroxyethyl, quantum yield 50.1%
50
Figure 1: Solid-phase strategy for the preparation of 6-8 carboxamides
described previously17,20 and properties of selected compounds
12-16
method of preparation, discovered in the end of nineties,
Despite detailed research into this field, a aforementioned
studies were incomplete due to the impossibility to apply the
original solid-phase approach to the preparation of isomers
with the carboxamide group located in position 5. To reach
this goal, we switched to traditional solution-phase chemistry
to find a synthetic strategy for the desired compounds. Herein
we describe the method development, its application for the
preparation of a set of target derivatives and comparisons of
their cytotoxic/fluorescence properties with the corresponding
6-8-carboxamides.
a number of variously substituted 3HQs have been synthesized
and studied. Recently, a deeper attention has been paid to
compounds bearing the carboxamide group located on a
benzene ring of the quinolinone scaffold. For such compounds,
a high-throughput solid-phase synthesis concept has been
developed17-19 and targeted chemical libraries of 3HQs with the
carboxamide group located in position 6, 7 and 8 were
Results and discussion
Synthesis
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The initial strategy (Scheme 1) was based on the method of Reflux with propylamine in chloroform (10% solution) was
preparation of the corresponding 6-8 carboxamides reported successfully used on a small scale (milligram quantities). On a
previously.17 In such cases the key building block was 3-amino- larger scale (quantities above 100 mg), the method was not
2-(methoxycarbonyl)benzoic acid
the compound from 3-nitrophtalic anhydride
intermediate
However, the crude purity of compound
3. We managed to synthesize successful due to an incomplete conversion and chloroform
1
via had to be replaced by DMF.
2
according to described procedures.23,24
NaOH
MeOH
reflux
2hrs
SOCl2
Pd/C
H2, MeOH
rt, 2 hrs
3
after the catalytic
NO2
O
30-40 o
C
NH2
O
O
NH2
O
O
NO2
O
O
6 hrs
O
O
reduction step was low. Conversion of carboxylic acid
corresponding amide was tested with propylamine.
Unfortunately, the attempt to synthesize compound with use
3 to the
O
O
OH
OH
O
OH
MeOH
reflux
2hrs
O
2
8
10
9
4
86%
81%
98%
NaOH, MeOH
reflux, 2hrs
of the DIC/HOBt method afforded the product, only as a part
of a complex mixture. We subsequently reversed the reaction
sequence and propylamine was acylated directly with
PhCOCH2Br
TEA, DMF, rt, 2 hrs
NO2
O
NH2
O
OH
OH
O
O
compound
the expected product was not obtained and the reaction
afforded pure 4-nitro-2-propylisoindoline-1,3-dione
Although we managed to hydrolyze the intermediate to yield
2-nitro-6-(propylcarbamoyl)benzoic acid its catalytic
hydrogenation led only to a mixture of compounds and the
desired product was not isolated. Additionally, alkylation of
acid with bromoacetophenone did not lead to the
corresponding phenacylester (which could be also applied for
2 via the corresponding acylchloride. In this case,
O
11
93%
O
13a
70%
O
O
5.
PhCOCH2Br
TEA, DMF, rt, 2 hrs
5
Pd/C
H
2, MeOH
rt, 2 hrs
6,
NO2
O
O
O
O
7
O
6
O
12a
72%
the preparation of target 3HQs) but intermediate
detected instead.
5 was
Scheme 2: Strategy for the preparation of bis(phenacyl)-3-aminophthalates
13a
For fluorescence and biological assay purposes we also
managed to develop re-esterification of compound 14a to
prepare methyl derivative 16a (Scheme 3).
O
NH2
O
HN
O
TFA
reflux
2 hrs
O
O
PrNH2, DMF
50 oC, 2 hrs
O
O
O
O
OH
OH
O
N
H
N
H
O
O
14a
88%
15a
13a
35%
NaOH, MeOH
reflux, 60 min
Scheme 1: Attempt to synthesize methyl 2-amino-6-
(propylcarbamoyl)benzoate 7 according to previously reported procedure
O
O
O
OH
The alternative strategy was based on the preparation of
bis(phenacyl)-3-aminophthalates 13 as the precursors for the
formation of the 3HQ scaffold. Due to limited purity after
N
H
16a
34%
catalytic reduction of compound
synthesized first, via the formation of the corresponding
acylchloride. Subsequent reduction afforded compound in an
2, dimethylester 8 was
Scheme 3: Conversion of intermediate 13a to hydroxyquinolinone derivative
15a
9
With use of developed procedures, a set of model
compounds (Table 1) were prepared from various
bromoacetophenones and amines (Figure 2). To allow for the
comparative study of the structure-cytotoxicity and structure-
fluorescence relationship, we selected the same building
blocks and their combinations as used previously for the
preparation of 6-8 carboxamides.20,21 The developed
procedure was generally applicable, only the cyclization of
intermediate 13h had to be performed in anhydrous
phosphoric acid instead of TFA which did not work.
excellent purity which was smoothly hydrolyzed to obtain pure
3-aminophthalic acid 10. Compound 10 was alkylated with
bromoacetophenone to give bis(phenacyl)-3-aminophtalate
13a. It is worth mentioning that an alternative strategy based
on the hydrolysis of compound
8 followed by alkylation of
intermediate 11 failed in the stage of catalytic hydrogenation
of compound 12, which afforded only a complex mixture of
compounds (Scheme 2). Cyclization of intermediate 13a to
3HQ derivative 14a was performed with use of TFA as
described earlier for similar derivatives.12 The final step of the
sequence was aminolysis of compound 14a with propylamine
to obtain final 3HQ 15a. Two methods have been developed:
Fluorescence properties
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2-Aryl-3-hydroxyquinolin-4(1H)-ones typically exhibit dual
fluorescence spectrum with two sufficiently separated
emission bands, which allows for their possible application as
fluorescent labels.10,11 Type/location of different substituents
on the 3HQ scaffold can significantly affect the emission
spectra. In the case of different isomeric 3HQ-carboxamides,
we have already reported that positioning of the carboxamide
group strongly influences the resulting fluorescence
properties: 6-Carboxamides exhibited two well separated
maxima whereas 8-carboxamides provided only one emission
maximum at lower wavelength and extremely low quantum
yields.22
Figure 2: List of used haloketones and amines
R1
H
R2
Yielda (%)
70
68
84
65
82
77
68
87
88
87
93
84
90
95
81
79
35
45
64
40
31
81
35
24
34
30
34
32
Figure 3: Different sterical features of isomeric 3HQ-carboxamides
Entry Cmpd.
1
13a
13b
13c
13d
13e
13f
-
A different situation was expected in the structure of 5-
carboxamides; the steric repulsion between two carbonyl
groups enforces the conformation in which the carboxamide is
not in the same plain with the aromatic moiety and
conjugation is lost. This fact has been proved by X-ray analysis
of compound 15a (Picture 1). However, the consequence of
this feature to the resulting fluorescence and biological
properties was unclear.
2
3,5-diCl-4-NH2
4-CH3
-
3
-
4
4-OCH3
-
5
4-F
-
6
3-Br
-
7
13g
13h
14a
14b
14c
14d
14e
14f
3-NO2-4-Cl
3-NO2-4-N-PIP
H
-
8
-
9
-
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
3,5-diCl-4-NH2
4-CH3
-
-
4-OCH3
-
4-F
-
-
3-Br
14g
14h
15a
15b
15c
15d
15e
15f
3-NO2-4-Cl
3-NO2-4-N-PIP
H
-
-
Propyl
Propyl
Propyl
Propyl
Propyl
Propyl
Hydroxyethyl
3,5-diCl-4-NH2
4-CH3
4-OCH3
4-F
3-Br
15g
15h
15i
3,5-diCl-4-NH2
3,5-diCl-4-NH2
3,5-diCl-4-NH2
3,5-diCl-4-NH2
H
Picture 1: X-ray analysis of compound 15a. Hydrogen atoms have been
omitted for the sake of clarity. Displacement ellipsoids are drawn at the 50%
probability level.
Benzyl
15j
H
-
16a
16b
From the initial results of the fluorescence study in
dimethyl sulfoxide (DMSO), it was evident that the existence of
the dual fluorescence spectrum was not significantly affected
by the location of the carboxamide group at position 5.
Although the intensity of the lower wavelength maximum was
reduced (Figure 4, solid line), it was still noticeable and
resembled the emission spectra of 7-carboxamides.22 On the
other hand, the presence of the methyl ester instead of
3,5-diCl-4-NH2
-
aCalculated after the cyclization step
Table 1: List of synthesized 3HQs and bis(phenacyl)-3-aminophthalates
The difference could be explained by the strong intramolecular
hydrogen bonding in the structure of 8-carboxamides which
does not exist in the case of the 6- and 7-carboxamide
analogues (Figure 3).
carboxamide (3HQs 16a, 16b) led to complete loss of the
emission maximum at lower wavelength and the dual
fluorescence spectrum was not detected. 3HQs 14 with the
phenacyl ester moiety did not give consistent results: For the
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majority of them the dual fluorescence spectrum was lost, only systems, such as cells or tissues, where the local concentration
two 3HQs 14a and 14f provided the second (higher of the dye cannot be easily controlled and generally the label is
wavelength) emission maximum. In contrast, 3HQ 14g not distributed homogenously. In each studied case, the
afforded only the lower wavelength emission maximum (Table emission spectra retained the same shape at different pHs,
2) and compound 14h did not exhibit any fluorescence at all. whereas the fluorescence intensity changed (Figure 5). The
To highlight the key effect of the 3HQ scaffold, we have also maximum fluorescence intensity was reached at pH 3.60, 6.41,
studied bis(phenacyl)esters 13. Although their fluorescence 5.23 and 5.75 for 13c, 14a, 15d and 16a, respectively. The pH
has been observed, the dual fluorescence spectra were not dependences of fluorescence intensity had a similar shape for
obtained and their emission maximum was significantly lower all investigated compounds: At acidic pH values the
compared to 3HQs (520-560 nm for 3HQs 14
compounds 13).
-
16, 454-480 for fluorescence intensity increased with increasing pH, reached
the maximum and then gradually decreased (Figure 5, below).
In spite of the fact that the ratiometric measurement was not
possible, the pH dependence of fluorescence intensity for 13c
was linear (y = -8.7349x + 132.15, R2 = 0.9936) in the pH range
4.62–9.22 which could be beneficial, especially for biological
measurement.
80
60
40
20
0
d
Entry Cmpd λexc (nm)a λem,1 (nm)b λem,2 (nm)c I1/I2
φ (%)e
43.43
16.65
48.67
20.15
3.66
1
13a
13b
13c
13d
13e
13f
394
373
390
371
373
394
394
395
402
413
405
403
404
407
419
-
474
467
464
454
462
474
472
480
474
-
-
-
-
-
-
-
-
-
-
2
-
3
-
4
-
5
-
6
-
19.87
5.43
7
13g
13h
14a
14b
14c
14d
14e
14f
-
8
-
0.17
9
555
560
555
560
556
555
-
0.1158 11.20
300
400
500
600
700
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
-
-
-
-
19.57
10.44
28.91
10.84
Wavelength (nm)
-
Figure 4: Excitation and emission spectra for 13c (dash line), 15d (solid line)
and 16a (dotted line).
-
-
478
481
-
0.0990 7.26
Quantum yields within the group of 5-carboxamides 15
were mostly similar, although slightly lower compared to
analogical 6/7-carboxamides.22 Nonetheless, there was no
clear relationship between their values and the structural
features of these molecules. A quite different situation was
observed for phenacyl-3HQs 14 which provided a wide range
of values from 0.72% to 28.9%. It could be concluded that the
presence of 2-phenyl with strongly electron withdrawing
groups (such as nitro, fluoro) significantly diminished the
quantum yields (compounds 14g and 14h), whereas
compounds with electron-donating groups (such as methoxy,
amino, methyl) provided higher values. Similar dependence
14g
14h
15a
15b
15c
15d
15e
15f
-
-
0.72
-
-
403
409
404
400
404
403
415
411
410
412
402
416
449
467
464
454
455
457
456
468
461
471
-
527
531
526
525
528
520
532
532
531
530
547
554
0.1024 36.14
0.0627 37.63
0.1025 14.76
0.1146 38.61
0,1123 42.54
0.0698 30.80
0.0602 42.74
0.0893 24.11
0.0683 37.10
0.0855 25,51
15g
15h
15i
15j
16a
16b
-
-
39.78
29.96
have been observed for bis(phenacyl)esters 13
.
-
a λex, excitation wavelength.
The study was further expanded to evaluate the
relationship between fluorescence properties and pH. For this
b λem,1, the fluorescence emission maximum at lower wavelengths.
c λem,2, the fluorescence emission maximum at higher wavelengths.
d I1/I2, the ratio of fluorescence maxima intensities.
purpose, representative compounds 13c, 14a, 15d and 16a
with the highest quantum yields and/or dual-band spectra e φ, fluorescence quantum yield (determined with quinine sulphate in 0.5 M
sulphuric acid (φ = 0.57725), taken as a reference fluorescence standard).
were selected. The pH measurements were performed in a
solution consisting of 9:1 v/v 0.1 M phosphate buffer/dimethyl
sulfoxide with the concentration of investigated compound
being 10 μg.mL-1. Surprisingly, in aqueous solution the
emission spectra totally lost their dual character. The loss of
the dual shape of emission spectra did not enable us to apply
the ratio of the maximum intensities as a signal. The intensity
ratio does not usually depend on the label concentration
which is an important advantage in complex biological
Table 2: Fluorescence properties of synthesized compounds (measured in
dimethyl sulfoxide, conc. 0.1 mg.mL-1).
Cytotoxic activity
To allow for the structure-activity relationship studies, the
synthesized compounds were screened against the same
cancer cell lines as their analogues, that have previously been
studied: CCRF-CEM (T-lymphoblastic leukaemia), CEM-DNR (T-
lymphoblastic leukaemia, daunorubicin resistant), K562 (acute
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myeloid leukaemia) and K562-TAX (acute myeloid leukaemia, corresponding methylesters (16a,b) provided approximately
paclitaxel resistant), A549 (human lung adenocarcinoma), the same results. On the other hand, cytotoxicity of 3HQs-5-
HCT116 (human colorectal cancer), HCT116p53-/- (human phenacylesters 14 was in general significantly higher, with
colorectal
cancer,
p53
deficient),
U2OS
(human compound 14b being the most active derivative from the
osteosarcoma). The therapeutic index (TI) was evaluated using whole set. IC50 of aminophthalate 14b for A-549, K56A, CEM,
one representative of non-malignant cell lines – BJ (human K562-TAX and CEM-DNR was comparable to isomeric
fibroblasts). The obtained results are summarized as the IC50 aminoterephthalate.2 In contrast, 4-methylphenyl phthalate
values in Table 3.
derivative 14c was inactive compared to isomeric
aminoterephthalate that exhibited micromolar IC50 for all
tested lines.2 The reversed dependence was observed for the
unsubstituted phenacylester 14a (Figure 6). The majority of
active compounds were less active against the CEM-DNR
multidrug resistant cell line overexpressing the multidrug
resistance protein
1
(MRP-1), than against highly
chemosensitive parental CCRF-CEM cell line. However, the
opposite pattern was identified in the case of P glycoprotein
(Pgp-1) overexpressing multidrug resistant K562-TAX cell line
which was more sensitive than parental K562 cell line.
Interestingly, CEM-DNR cells also lack topoisomerase IIα gene,
which has been previously reported as a molecular target for
quinolone derivatives. It is suggesting either the
topoisomerase II
α as a molecular target for 3HQs-5-
phenacylesters 14 or involvement of MPR-1 but not Pgp-1 in
drug efflux and resistance mechanisms.26 The growth
inhibitory activity of compounds against human colorectal
cancer cell line HCT116 and its p53 deficient counterpart
(HCT116p53-/-) were similar, thus indicating independence of
cell death mechanism on the p53 gene. The therapeutic index
of the most active compound 14b ranged from 15-30 for
majority of cell lines, suggesting preferential activity against
malignant cells.
Finally, two representative compounds were subjected to the
fluorescent microscopy assay. We selected the most cytotoxic
compound 14b along with the most active carboxamide
derivative 15i. The results are depicted in Picture 2. The
microscopy imaging is showing that the fluorescent
compounds are penetrating cellular membranes of living cells.
The highest intensity of the fluorescence and accumulation of
the compound was observed in the cytoplasm, with discrete
nuclear spots. Maximum cytoplasmic positivity was seen in
perinuclear region, the staining pattern was overlapping in
both emission wavelengths. Detailed subcellular localization is
to be determined in future studies.
Figure 5: Illustrative emission spectra of 13c (red, solid line pH 5.75, dashed
line pH 7.69 and dotted line pH 12.49), 14a (green, solid line pH 6.43,
dashed line pH 2.48 and dotted line pH 11.53), 15d (black, solid line pH 3.60,
dashed line pH 6.49 and dotted line pH 12.49) and 16a (blue, solid line pH
5.75, dashed line pH 8.58 and dotted line pH 11.63) and fluorescence
intensity at different pH.
As in the case of bisphenacyl-2-aminoterephthalates,2 the
corresponding bisphenacyl-3-aminophthalates 13 did not
exhibit significant cytotoxic activity. However, an exception
has been observed for compound 13g which showed a
medium cytotoxicity against K562-TAX, U2OS and CEM cells.
Within the group of HQ-5-carboxamides 15, the similar SAR
pattern as for analogical 6-8 carboxamides was observed: The
highest activity was detected for 2-(3,5-dichloro-4-
Conclusions
We have developed a synthetic procedure for 3HQs-5-
carboxamides 15 to enable the study of their properties
compared to analogical 6-8 isomers. In the field of
fluorescence properties, the synthesized 5-carboxamides
exhibited similar results to their 7-isomers that have previously
been studied. In this regard, some derivatives showed a
potential to serve as pH indicators and/or molecular probes.
Based on the fluorescence microscopy imaging of U2OS cells
treated with two representative compounds 14b and 15i it was
demonstrated, that compounds enter live cells and show
preferential cytoplasmic staining. The cytotoxicity of 3HQs-5-
aminophenyl)-3HQs with unpolar
propyl and 15i -benzyl), whereas the unsubstituted
carboxamide 15j and compounds with polar 15g:N-
N-alkyl substituents (15b:N-
:N
(
hydroxyethyl) or basic (15h:N-piperidinyl-ethyl) ligands were
not cytotoxic. Structural change of propylamides (15a,b) to the
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carboxamides towards various cancer cell lines corresponded
to 8-carboxamides. The overall results show that the location
of the carboxamide group in position 5 rather decreases the
cytotoxicity activity compared to 6,7-carboxamides, however,
the evaluation of SAR data revealed the same pattern. Higher
cytotoxicity was detected for 3HQs-5-phenacylesters 14. The
most active compound 14b exhibited the similar activity as the
corresponding 7-phenacylester described previously. On the
other hand, the SAR pattern observed within the group of
available 5- and 7-phenacylesters showed an interesting
differences based on the location of the phenacylester moiety.
To explore the field in further details, 3HQs-6-phenacylesters
and 3HQs-8-phenacylesters will be synthesized and
systematically studied for biological activities and fluorescence
probing properties.
CCRF-
CEM
CEM
K562
-TAX
HCT116
p53 -/-
Cmpd.
K562
A549
HCT116
U2OS
BJ
-DNR
13a
13b
13c
13d
13e
13g
13h
14a
14b
14c
14d
14e
14f
>50 >50 >50 >50 >50
43
>50
>50
>50
>50
>50 >50
>50
>50
>50
>50
>50 >50 >50 >50
>50 >50 >50 >50
>50
>50
>50
>50
>50
>50
>50
>50
48
46
>50 >50 >50 >50 >50
>50 >50 >50 >50 >50
Picture 2: U2OS osteosacroma cancer cells treated with 14b (first row) and
15i (second row). Full size images are available in SI.
>50
12
37
17
8.3 >50
30
19
>50
12
>50
>50
>50
>50
>50 >50 >50 >50 >50
Acknowledgements
2.7
0.8
40
8.1
4.5
>50 >50
8.6
1.5
6.0
0.8
42
9.5
2.3
>50 >50
12
4.0
1.4
>50
10
2.4
>50
10
25
>50
1.6
The authors are grateful to projects CZ.1.07/2.3.00/30.0060,
CZ.1.07/2.3.00/30.0041 from the European Social Fund, from
Palacky University (Internal Grant No. IGA_PrF_2015_007,
IGA_LF_2015_031), National Sustainability Programme
(LO1304) and Czech Technology Agency (TE02000058).
2.7
2.2
2.3
20
8.8
6.7
2.3
24
7.6
13
4.2
4.0
4.6
6.2
13
13
23
6.5
3.5
3.0
8.7
12
4.0
3.3
2.7
11
10
5.4
10
>50
36
1.3
38
6.4
34
14g
14h
15a
15b
15c
15d
15e
15f
12
>50
7.7
>50
23
26
>50
>50 >50
32
32
>50
>50
10
26
23
39
44
>50
15
31
20
19
Notes and references
7.7
22
8.8
26
34
>50
7.5
27
7.2
20
12
34
>50
>50
32
1
2
3
P. Hradil, P. Krejčí, J. Hlaváč, I. Wiedermannová, A. Lyčka, V.
Bertolasi, J. Heterocyclic Chem., 2004, 41, 375-379.
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P. Hradil, J. Hlaváč, M. Soural, M. Hajdúch, M. Kolář, R.
>50
>50
>50
28
48
35
30
27
16
36
13
>50
>50
25
32
>50
24
21
17
46
14
47
46
10
27
17
9.3
45
>50
4.3
31
10
7.9
42
8.0
39
>50
15g
15h
15i
49
48
>50
48
Večeřová, Mini-Rev. Med. Chem., 2009, 9, 696-702.
>50
34
36
>50
4.6
30
25
27
40
8.6
45
4
5
P. Krejčí, P. Hradil, J. Hlaváč, M. Hajdúch WO2008028427 A1
Z. Sui, V.N. Nguyen, J. Altom, J. Fernandez, J.J Hilliard, J.I.
Bernstein, J.F. Barrett, K.A. Ohemeng, Eur. J. Med.
Chem.,1999, 34, 381-387.
3.3
34
10
48
49
6.7
2.5
45
6.9
49
24
4.0
18
15j
20
>50 >50 >50 >50
16a
16b
15
46
>50
9.8
4.7
5.8 4.6 27 5.5
4.6
6
7
M. Di Cagno, P.C. Stein, J. Stýskala, J. Hlaváč, N. Skalko-
Basnet. A. Brauer-Brandl, Eur. J. Pharm. Biopharm., 2012, 80,
657-662.
M. Di Cagno, J. Stýskala, J. Hlaváč, M. Brandl, A. Brauer-
Brandl, N. Skalko-Basnet. J. Liposome Res,. 2011, 21, 272-
278.
Table 3: Results of cytotoxicity for all synthesized compounds (relative IC50,
ꢀM). Average values from 3-4 independent experiments with SD ranging
from 10-25% of the average values
O
O
O
O
O
R1
8
9
K. Motyka, B. Vankova, J. Hlaváč, M. Soural, J. Fluoresc.,
2011, 21, 2207-2212.
K. Motyka, J. Hlaváč, M. Soural, P. Hradil, P. Krejčí, L. Kvapil,
M. Weiss, Tetrahedron Lett., 2011, 52, 715-717.
10 D.A. Yushchenko, V.V. Shvadchak, A.S. Klymchenko, G.
OH
OH
O
O
N
H
N
H
R1
R1
R1
O
R1 = 3,5-diCl-4-NH2 IC50 = 0.8 ꢀM
IC50 = 1 ꢀM
Duportail, Y. Mely, V.G. Pivovarenko, New J. Chem., 2006, 30
774-781.
11 D.A. Yushchenko, M.D. Bilokin´, O.V. Pyvovarenko, G.
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2006, 47, 905-908.
,
IC50 = 2.9 ꢀM
IC50 = 40 ꢀM
IC50 = 10 ꢀM
R1 = CH3
R1 = H
IC50 = 132 ꢀM
Figure 6: Example of 3HQs-phenacylesters cytotoxicity dependence on the
location of the ester group (for K562 cell line)
12 M. Soural, P. Hradil, S. Křupková, J. Hlaváč J. Mini-Rev. Org.
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6 | J. Name., 2012, 00, 1-3
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