Synthesis, leishmanicidal, trypanocidal and cytotoxic activity of quinoline-hydrazone hybrids

Article abstract of DOI:10.1016/j.ejmech.2015.07.018

Abstract Cutaneous leishmaniasis and Chagas disease are vector-borne parasitic disease causing serious risks to million people living in poverty-stricken areas. Both diseases are a major health problem in Latin America, and currently drugs for the effective treatment of these diseases have important concerns related with efficacy or toxicity than need to be addressed.We report herein the synthesis and biological activities (cytotoxicity, leishmanicidal and trypanocidal activities) of ten quinolone-hydrazone hybrids. The structure of the products was elucidated by spectrometric analyses. The synthesized compounds were evaluated against amastigotes forms of L. (V) panamensis which is the most prevalent Leishmania species in Colombia and Trypanosoma cruzi that is the major pathogenic species to humans; in turn, cytotoxicity was evaluated against human U-937 macrophages.Compounds 6b, 6c and 8 showed activity against L. (V) panamensis with EC₅₀ of 6.5 ± 0.8 μg/mL (21.2 μM), 0.8 ± 0.0 μg/mL (2.6 μM) and 3.4 ± 0.6 μg/mL (11.1 μM), respectively, while compounds 6a and 6c had activity against T. cruzi. with EC₅₀ values of 1.4 ± 0.3 μg/mL (4.8 μM) and 6.6 ± 0.3 μg/mL (4.6 μM), respectively. Even compound 6a showed better activity against T. cruzi than the standard drug benznidazole with EC₅₀ Combining double low line 10.5 ± 1.8 μg/mL (40.3 μM).Analysis of the results obtained against leishmaniasis indicates that antiparasite activity is related to the presence of 2-substituted quinoline (isoquinolinic core) and the hydroxyl group in positions 3 and 4 of the aromatic ring. Although the majority of these compounds were highly cytotoxic, the antiparasite activity was higher than cytotoxicity and therefore, they still have potential to be considered as hit molecules for leishmanicidal and trypanocidal drug development.

Full text of DOI:10.1016/j.ejmech.2015.07.018

Accepted Manuscript
Synthesis, Leishmanicidal, Trypanocidal and Cytotoxic Activity of Quinoline-
Hydrazone Hybrids
Juan Carlos Coa, Castrillón L. Wilson, Cardona G. Wilson, Miguel Carda, Victoria
Ospina, July Andrea Muñoz, Iván D. Vélez, Sara M. Robledo
PII:
S0223-5234(15)30150-1
10.1016/j.ejmech.2015.07.018
EJMECH 7999
DOI:
Reference:
To appear in: European Journal of Medicinal Chemistry
Received Date: 17 April 2015
Revised Date: 6 July 2015
Accepted Date: 9 July 2015
Please cite this article as: J.C. Coa, C.L Wilson, C.G Wilson, M. Carda, V. Ospina, J.A. Muñoz,
I.D. Vélez, S.M. Robledo, Synthesis, Leishmanicidal, Trypanocidal and Cytotoxic Activity of
Quinoline-Hydrazone Hybrids, European Journal of Medicinal Chemistry (2015), doi: 10.1016/
j.ejmech.2015.07.018.
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ACCEPTED MANUSCRIPT
Synthesis, Leishmanicidal, Trypanocidal and Cytotoxic Activity of
Quinoline-Hydrazone Hybrids
Graphical Abstract
Juan Carlos Coa 1, Wilson Castrillón L1, Wilson Cardona G1 *, Miguel Carda 2, Victoria Ospina3,
July Andrea Muñoz3, Iván D. Vélez 3, Sara M. Robledo 3
1
Chemistry of Colombian Plants, Institute of Chemistry, Exact and Natural Sciences School,
University of Antioquia-UdeA; Calle 70 No. 52-21, A.A 1226, Medellín, Colombia; e-mail:
juancoa2@gmail.com; w.castrillon@hotmail.com
2
Department of Inorganic and Organic Chemistry, Jaume I University, E-12071 Castellón, Spain; e-
mail: mcarda@qio.uji.es
3
PECET-Medical Research Institute, School of Medicine, University of Antioquia-UdeA. Calle 70
No. 52-21, A.A 1226, Medellín, Colombia;
e-mail: sara.robledo@udea.edu.co; ivan.velez@udea.edu.co; victoriaospina@hotmail.com;
julyandru37@gmail.com.
* Author to whom correspondence should be addressed; e-mail: wilson.cardona1@udea.edu.co;
phone: +574-219-5653; fax: +574-233-0120.

ACCEPTED MANUSCRIPT
Synthesis, Leishmanicidal, Trypanocidal and Cytotoxic Activity of Quinoline-Hydrazone
Hybrids
Juan Carlos Coa 1, Wilson Castrillón L1, Wilson Cardona G1 *, Miguel Carda 2, Victoria Ospina3,
July Andrea Muñoz3, Iván D. Vélez 3, Sara M. Robledo 3
1
Chemistry of Colombian Plants, Institute of Chemistry, Exact and Natural Sciences School,
University of Antioquia-UdeA; Calle 70 No. 52-21, A.A 1226, Medellín, Colombia; e-mail:
juancoa2@gmail.com; w.castrillon@hotmail.com
2
Department of Inorganic and Organic Chemistry, Jaume I University, E-12071 Castellón, Spain; e-
mail: mcarda@qio.uji.es
3
PECET-Medical Research Institute, School of Medicine, University of Antioquia-UdeA. Calle 70
No. 52-21, A.A 1226, Medellín, Colombia;
e-mail: sara.robledo@udea.edu.co; ivan.velez@udea.edu.co; victoriaospina@hotmail.com;
julyandru37@gmail.com.
* Author to whom correspondence should be addressed; e-mail: wilson.cardona1@udea.edu.co;
phone: +574-219-5653; fax: +574-233-0120.
1

ACCEPTED MANUSCRIPT
Abstract
Cutaneous leishmaniasis and Chagas disease are vector-borne parasitic disease causing serious risks to
million people living in poverty-stricken areas. Both diseases are a major health problem in Latin
America, and currently drugs for the effective treatment of these diseases have important concerns
related with efficacy or toxicity than need to be addressed.
We report herein the synthesis and biological activities (cytotoxicity, leishmanicidal and trypanocidal
activities) of ten quinolone-hydrazone hybrids. The structure of the products was elucidated by
spectrometric analyses. The synthesized compounds were evaluated against amastigotes forms of L.
(V) panamensis which is the most prevalent Leishmania species in Colombia and Trypanosoma cruzi
that is the major pathogenic species to humans; in turn, cytotoxicity was evaluated against human U-
937 macrophages.
Compounds 6b, 6c and 8 showed activity against L. (V) panamensis with EC50 of 6.5 ± 0.8 µg/mL
(21.2µM), 0.8 ± 0.0 µg/mL (2.6 µM) and 3.4 ± 0.6 µg/mL (11.1 µM), respectively, while compounds
6a and 6c had activity against T. cruzi. with EC50 values of 1.4 ± 0.3 µg/mL (4.8 µM) and 6.6 ± 0.3
µg/mL (4.6 µM), respectively. Even compound 6a showed better activity against T. cruzi than the
standard drug benznidazole with EC50 = 10.5 ± 1.8 µg/mL (40.3 µM).
Analysis of the results obtained against leishmaniasis indicates that antiparasite activity is related to the
presence of 2-substituted quinoline (isoquinolinic core) and the hydroxyl group in positions 3 and 4 of
the aromatic ring. Although the majority of these compounds were highly cytotoxic, the antiparasite
activity was higher than cytotoxicity and therefore, they still have potential to be considered as hit
molecules for leishmanicidal and trypanocidal drug development.
Keywords: leishmaniasis; Chagas disease; antiprotozoal activity; cytotoxicity; quinoline; hydrazone;
hybrids
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1. Introduction
Cutaneous leishmaniasis and Chagas disease are causes of high morbidity in several countries of
tropical and subtropical regions where these diseases remain a significant health problem affecting
mainly people living in poverty-stricken areas. Both are considered by WHO as two of the 17 neglected
diseases due to lack of interest by the pharmaceutical industry to develop new or better drugs [1].
Cutaneous leishmaniasis involves a wide spectrum of clinical manifestations, ranging from small
nodules, plaques or ulcers in the skin to severe mucosal tissue destruction affecting 1.2 – 1.5 million
people around world every year. In the American region the disease can be caused by various species of
Leishmania that include: L. panamensis, L. braziliensis, and L. guayanensis (members of the Viannia
subgenus) and L. mexicana and L. amazonensis (members of the Leishmania subgenus). L. (V)
panamensis is one of the most prevalent Leishmania species involved in human cases of cutaneous
leishmaniasis in Colombia. This protozoan parasite is transmitted to humans through the bite of
phlebotominae sandflies of the Lutzomyia genus [2]. On the other hand, Chagas disease (also named
American trypanosomiasis) affects around 10 million people in Latin America. The disease is produced
by the protozoan parasite Trypanosoma cruzi that is transmitted to the mammalian host through the bite
of triatomine bugs belonging to Triatoma, Rhodnius and Panstrongylus genus [3].
The current chemotherapies are based on old drugs, pentavalent antimonials (meglumine antimoniate
and sodium stibogluconate) for cutaneous leishmaniasis or nitroaromatic compounds (benznidazole and
nifurtimox) for Chagas disease. However, all of them have various toxic effects on the patients that are
associated with high doses and long therapeutic schemes. Moreover, they are no longer as effective as
before due to the emergence of drug resistance in the parasite making the problem more complex [4-6].
A quinolinic core is a structural feature of several bioactive compounds. Thus, this core is an interesting
constituent for new drugs design. Anti-mycobacterial, anti-microbial, anti-convulsant, anti-inflamatory,
anti-tumoral, cardiovascular but also leishmanicidal and trypanocidal, are some biological activities
exhibited by compounds having this heteroaromatic ring [7-15]. On the other hand, hydrazones
constitute an important type of biologically active compounds which have high ability to elicit an
leishmanicidal and trypanocidal activity [16-18]; thus for example, the 4-benzyloxy N´,N´-
diethylbenzohydrazone (figure 1a) is one of the synthetic benzyloxy protected hydrazone series with an
Inhibitory Concentration (IC50) of 6.25 µg/mL (21µM) against (L) major promastigotes [19]. In turn,
the nitro derivative 1b (figure 1) exhibited an IC50 value lower than standard drugs pentamidine and
amphotericin B when tested on (L) donovani promastigotes [20]. Moreover, evaluation of 1H-pyrazole-
4-carbohydrazides derivatives against (L) amazonensis promastigotes showed that the most active
compounds were those with X = Br, Y = NO2 and X = NO2, Y = Cl (figures 1c and 1d) with CI50 20.71
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µg/mL (50 µM) and 29.58 µg/mL (80 µM) respectively [21]. Finally, hybrid compounds containing
hydrazones and benzofuroxan pharmacophores (figure 1e) showed selective trypanocidal activity with
IC50 6.80 µg/mL (19.8 µM) [22] while brazilizone A (figure 1f), a new potent trypanocydal prototype,
showed an IC50 of 1.92 µg/mL (5.3 µM) [23].
The combination of two pharmacological agents into a single molecule, called hybrid molecule is an
emerging strategy in medicinal chemistry and drug discovery research [24,25]. These hybrid
molecules may display dual activity but do not necessarily act on the same biological target [26-28]. In
the search for new therapeutic alternatives to treat cutaneous leishmaniasis and Chagas disease we
designed and synthesized a series of novel hydrazones having quinoline cores and their cytotoxicity
and leishmanicidal and trypanocidal activities were evaluated in vitro (figure 2).
2. Results and Discussion
2.1. Chemistry
Quinaldine (1) was oxidized with selenium oxide to produce the aldehyde 2 in 80% yield [29], which
was treated with iodine and methanol in basic solution affording ester 3 in 70% yield [30]. Then,
compound 3 was submitted to nucleophilic substitution with hydrazine hydrate obtaining acylhydrazide
4 in 75% yield [31], that was coupled with different hydroxyaldehydes in aqueous medium obtaining
hydrazones 6a-6e in 40-85% yields [32]. The synthetic strategy is summarized in Scheme 1. With this
strategy we only perform modifications of aromatic ring of the side chain in order to keep the two
pharmacological agents. Hydrazones 7a-7d and 8 were obtained following the same synthetic strategy
starting from compounds 4-quinolinecarboxaldehyde and isoquinoline-1-carboxylic acid, respectively
(figure 3).
2.2. Biological activities
The effect of hydrazones on cell growth and viability was assessed in human macrophages (U937
cells) which are the host cells for L. (V) panamensis and T. cruzi parasites. On the other hand, the
antiparasite activity of these compounds was tested on intracellular amastigotes of L. (V.) panamensis
and T. cruzi according to the ability of these compounds to reduce the amount of parasite inside
infected macrophages. Results are summarized in Tables 1 and 2.
All novel hydrazones with exception of 7c and 7d, were highly cytotoxic to U937 cells showing LC50 <
100.0 ꢀg/mL (Table 1). Compound 7d showed moderate cytotoxicity (LC50 > 100.0 ꢀg/mL, 347.3 µM)
while compound 7c had no cytotoxicity (LC50 > 200 ꢀg/mL, >650.8 µM). In turn, amphotericin B,
benznidazole and meglumine antimoniate showed high, moderate and no cytotoxicity, respectively.
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Compounds 6b-6e, 7a and 8 showed activity against intracellular amastigotes of L. (V) panamensis
with percentages of inhibition higher than 50% at concentrations < 20 ꢀg/mL (Table 1). The most
active compounds was 6c inhibiting in 64% the amount of intracellular amastigotes at 1.0 ꢀg/mL
followed by compound 8 with 62% of inhibition at 5.0 ꢀg/mL. Others compounds showed low activity
against L. (V) panamensis intracellular amastigotes. As expected, amphotericin B and meglumine
antimoniate, standar drugs to treat cutaneous leishmaniasis, demonstrated activity against intracellular
amastigotes with percentages of inhibition > 70.0% at 0.05 and 10.0 ꢀg/mL, respectively.
On the other hand, only compound 6a showed activity against intracellular amastigotes of T. cruzi,
inhibiting the amount of parasite in 50.4% at concentrations lower than 10 µg/mL (Table 1).
Benznidazole, one of the standard drugs to treat Chagas disease was active against intracellular
amastigotes of T. cruzi inhibiting 87.6% of the parasite growth at 20 ꢀg/mL.
The leishmanicidal and trypanocidal activities were confirmed by determining the effective
concentration 50 (EC50) that corresponds to the concentration of drug that gives the half-maximal
reduction of the parasite growth (Table 2). Dose-response relationship showed that compounds 6b-6e
and 8 were highly active against intracellular amastigotes of L. (V) panamensis with EC50 < 20 ꢀg/mL.
The most active compound was 6c with an EC50 of 0.8 ± 0.0 ꢀg/mL (2.6 µM), followed by 6b with an
EC50 of 6.5 ± 0.8 ꢀg/mL (21.2 µM). As expected again, the leishmanicidal drugs amphotericin B and
meglumine antimoniate showed activity with low EC50 values. In turn, compounds 6a, 6c and 7b were
active against intracellular amastigotes of T. cruzi with EC50 of 1.4 ± 0.3 (4.8 µM), 6.6 ± 0.3 (4.6 µM)
and 20.8 ± 0.5 ꢀg/mL (67.7 µM), respectively (Table 2). In this case, benznidazole showed activity
with an EC50 of 10.5 + 1.8 ꢀg/mL (40.3 µM).
The leishmanicidal activity of hydrazones 6b-6e and 8 and trypanocidal activity of hydrazones 6a, 6c
and 7b were higher than their cytotoxicity. Thus, the IS values calculated for these compounds ranged
from 2.6 to 4.7 in leishmanicidal compounds and from 0.5 to 11.6 in trypanocidal compounds (Table
2). As demonstrated elsewhere, amphotericin B and meglumine antimoniate have very high IS values.
Although compounds 6c and 8 showed better activity than meglumine antimoniate, the IS of these
compounds is affected by their high cytotoxicity. These results suggest that biological activity of the
hydrazones reported here is selective, being more active against L. (V) panamensis than U937 cells. On
the other hand, only the trypanocidal activity of hydrazones 6a was also higher than their cytotoxicity
with an IS value of 11.6.
According to the results obtained against leishmaniasis, it is interesting to note that compounds with 2-
substituted quinoline or isoquinolinic core (6a-6e vs 8) are more active than those with 4-substituted
quinoline (7a-7d). This higher activity could be due to a possible mechanism of action for these
5

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compounds as iron chelators. In this mechanism, iron complexes with the nitrogen atom in hydrazone
and with the oxygen atom in the carbonyl group [33]. In our case, we consider that iron complexes with
the 2-substituted quinolone or isoquinolinic nitrogen instead of complexing with the oxygen in the
carbonyl group because nitrogen is more basic. The mode of action of iron chelators have been
reported for hydrazones in other protozoan diseases [34]. Studies in vitro have shown that chelating
agents are able to inhibit parasite growth and proliferation by deprivation of iron, which is an essential
nutrient for cell growth and division [35].
Other possible mechanisms of action for these compounds may be formulated in terms of conjugated
addition of nucleophilic amino acid residues present in target enzymes of Leishmania e.g. such
cysteine proteases [36], in a Michael addition [37]. An electrophilic conjugated system could be
generated from o-hydroxybenzylidene-N-acylhydrazone framework due to the ability of this system to
be converted into an electrophilic quinone methide intermediate through a pericyclic rearrangement
[38]. This mechanism has been reported for other α,β-unsaturated compounds such as lactones,
chromones and cinnamic acid esters [39-41].
Results of the present work suggest that the hydroxyl group in the positions 3 and 4 in the aromatic ring
is determinant for the activity. The importance of this position may be due to the best molecular
recognition ability towards target bioreceptors by forming hydrogen bonds [42].
3. Conclusions
The synthesis, leishmanicidal and trypanocidal screening of 10 quinoline-hydrazone hybrids are
reported. Three of them were active against L. (V) panamensis (6b, 6c and 8) and two of them against
T. cruzi (6a and 6c) with EC50 values lower than 10 µg/mL, being 6b and 6a the most active
compounds for L. (V) panamensis and T. cruzi, respectively. The antiparasite activity and the selectivity
showed by these compounds suggest that they have potential as templates for drugs development
against these parasites. The presence of 2-substituted quinoline or isoquinolinic core and hydroxyl
group in positions 3 and 4 of the aromatic ring increase the leishmanicidal activity.
4. Experimental Section
4.1. Chemical Synthesis
4.1.1. General Remarks
Synthesis of acylhydracides were carried out in a MW domestic oven adapted for the use of a reflux
condenser and magnetic stirrer at a constant power (400W). Hydrazones were synthesized in an
ultrasonic cleaner (BRANSON). NMR spectra were recorded as DMSO-d6 solutions on an AMX 300
instrument (Bruker, Billerica, MA, USA) operating at 300 MHz for 1H and 75 MHz for 1C. Chemical
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shifts (δ) are expressed in ppm with the solvent peak as reference and TMS as an internal standard;
coupling constants (J) are given in Hertz (Hz). High resolution mass spectra were recorded using
electrospray ionization mass spectrometry (ESI-MS). A QTOF Premier instrument with an orthogonal
Z-spray-electrospray interface (Waters, Manchester, UK) was used operating in the
W-mode. The drying and cone gas was nitrogen set to flow rates of 300 and 30 L/h, respectively.
Methanol sample solutions (ca. 1 × 10−5 M) were directly introduced into the ESI spectrometer at a
flow rate of 10 µL/min. A capillary voltage of 3.5 kV was used in the positive scan mode, and the cone
voltage set to Uc = 10 V. For accurate mass measurements, a 2 mg/L standard solution of leucine
enkephalin was introduced via the lock spray needle at a cone voltage set to 85 V and a flow rate of
30 ꢀL/min. IR spectra were recorded on a Spectrum RX I FT-IR system (Perkin-Elmer, Waltham, MA,
USA) in KBr disks. Silica gel 60 (0.063–0.200 mesh, Merck, Whitehouse Station, NJ, USA) was used
for column chromatography, and precoated silica gel plates (Merck 60 F254 0.2 mm) were used for
thin layer chromatography (TLC).
4.1.1.1. Synthetic procedure for methyl quinoline-2-carboxylate preparation (3):
Quinoline-2-carbaldehyde 2 (2g, 12.7 mmol) was dissolved in methanol (20 mL) and solutions of
KOH (32 mmol, 1.8 g) and iodine (16.5 mmol, 4.2 g) in MeOH (each 6 mL) were successively
added at 0°C. The mixture was stirred for a period of 15 minutes and then was concentrated on a
rotatory evaporator, and the residue was purified by column chromatography over silica gel eluting
with hexane and a mixture of hexane-ethyl acetate (9:1 ratio) to obtain the ester in 70% yield (8.9
mmol, 1.7 g). Monitoring of the reaction progress and product purification was carried out by TLC.
4.1.1.2. Synthetic procedure for quinoline-2-carbohydrazide preparation (4):
To a solution of 3 (1.5 g, 8.0 mmol) in ethanol (10 mL) was added hydrazine monohydrate (16 mL of a
80% solution). The reaction mixture submitted to microwave irradiation and maintained under reflux
for 30 minutes. Then, the reaction mixture was poured on ice and the resulting precipitate was filtered
out affording the title compound in 75% yield (6 mmol, 1.1 g).
4.1.1.3. Synthetic procedure for hydrazones preparation:
A quinoline-2-carbohydrazide 4 (100 mg, 0.53 mmol) solution in water (2 mL) was sonicated for 2
minutes and then aldehyde 5 (0.53 mmol) and acetic acid (0.1 mL) were added dropwise to the reaction
mixture. Upon completion of the reaction (20–30 min), the product was filtered, sequentially washed
with water (20 mL) and ethyl ether (5 mL), dried in vacuo and recrystallized from ethanol to obtain the
corresponding hydrazones in yields ranging from 40% to 85%.
4.1.1.3.1. N'-[(1E)-(2-hydroxyphenyl)methylidene]quinoline-2-carbohydrazide (6a):
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Yield 50% (0.265 mmol, 77.2 mg); light yellow solid, M.p. 185–187°C; IR (cm−1): νmax 3457 (Ar-OH),
1
3323 (N-H), 1700 (C=O), 1502 (C=N), 1482 (C=CAr), 1268 ((C=O)-N), 775 (C-HAr). H-NMR
(DMSO-d6): δ 6.90-6.99 (H14, H16, m), 7.33 (H15, tapparent, J = 8.32 Hz), 7.55 (H17, dd, J = 7.74, 1.5 Hz),
7.75 (H7, tapparent, J = 7.60 Hz), 7.91 (H8, tapparent, J = 7.60 Hz), 8.10 (H6, d, J = 8.14 Hz), 8.20 (H3, d, J =
8.52 Hz), 8.23 (H9, d, J = 8.17 Hz), 8.61 (H4, d, J = 8.52 Hz), 8.89 (H11, s), 11.35 (OH), 12.53 (NH).
13C-NMR (CDCl3): δ 116.94 (C12), 119.07 (C14), 119.54 (C16), 119.96 (C3), 128.63 (C7), 128.98 (C6),
129.46 (C17), 129.75 (C8), 130.28 (C5), 131.23 (C9), 132.14 (C15), 138.60 (C4), 146.47 (C2), 149.70
(C11),
[M + H]+, Calcd for C17H13N3O2: 292.1086.
4.1.1.3.2. N'-[(1E)-(2,3-dihydroxyphenyl)methylidene]quinoline-2-carbohydrazide (6b):
150.57
(C10),
158.01
(C13),
161.22
(C=O).
EIMS:
m/z
292.1087
Yield 75% (0.40 mmol, 122.1 mg); light brown solid, M.p. 205-207°C; IR (cm−1): νmax 3382 (Ar-OH),
1
3289 (N-H), 1683 (C=O), 1503 (C=N), 1471 (C=CAr), 1274 ((C=O)-N), 772 (C-HAr). H-NMR
(DMSO-d6): δ 6.77 (H16, tapparent, J = 7.84 Hz), 6.89 (H15, dd, J = 7.77, 1.0 Hz), 6.97 (H17, dd, J = 7.77,
1.0 Hz), 7.77 (H7, tapparent, J = 7.76 Hz), 7.93 (H8, tapparent, J = 7.76 Hz), 8.13 (H6, d, J = 8.10 Hz), 8.23
(H3, H9, d, J = 8.57 Hz), 8.63 (H4, d, J = 8.51 Hz), 8.90 (H11, s), 9.22 (OH), 11.25 (OH), 12.54 (NH).
13C-NMR (CDCl3): δ 118.0 (C12), 119.24 (C15), 119.62 (C3), 119.67 (C16), 120.78 (C17), 128.70 (C7),
128.91 (C5), 129.50 (C6), 129.69 (C8), 131.22 (C9), 138.58 (C4), 146.12 (C2), 146.51 (C10), 146.73
(C14), 149.86 (C11), 151.24 (C13), 161.05 (C=O). EIMS: m/z 308.1036 [M + H]+, Calcd for C17H13N3O3:
308.1035.
4.1.1.3.3. N'-[(1E)-(2,4-dihydroxyphenyl)methylidene]quinoline-2-carbohydrazide (6c):
Yield 81% (0.43 mmol, 132.0 mg); yellow solid, M.p. 259-262°C; IR (cm−1): νmax 3459 (Ar-OH), 3309
(N-H), 1675 (C=O), 1501 (C=N), 1431 (C=CAr), 1225 ((C=O)-N), 770 (C-HAr). 1H-NMR (DMSO-d6):
δ 6.34 (H14, d, J = 2.23 Hz), 6.39 (H16, dd, J = 8.40, 2.23 Hz), 7.32 (H17, d, J = 8.40 Hz), 7.74 (H7,
tapparent, J = 8.0 Hz), 7.90 (H8, tapparent, J = 8.0 Hz), 8.09 (H6, d, J = 8.03 Hz), 8.18 (H3, d, J = 8.56 Hz),
8.22 (H9, d, J = 8.83 Hz), 8.60 (H4, d, J = 8.60 Hz), 8.75 (H11, s), 10.16 (OH), 11.55 (OH), 12.34 (NH).
13C-NMR (CDCl3): δ 103.15 (C14), 108.30 (C16), 111.0 (C12), 119.50 (C3), 128.60 (C7), 128.90 (C6),
129.40 (C5), 129.73 (C8), 131.20 (C9), 132.19 (C17), 138.56 (C4), 146.50 (C2), 149.90 (C10), 151.40
(C11), 160.10 (C15), 160.83 (C13), 161.33 (C=O). EIMS: m/z 308.1039 [M + H]+, Calcd for C17H13N3O3:
308.1035.
4.1.1.3.4. N'-[(1E)-(2,5-dihydroxyphenyl)methylidene]quinoline-2-carbohydrazide (6d):
Yield 47% (0.25 mmol, 76.5 mg); yellow solid, M.p. 229-232°C; IR (cm−1): νmax 3418 (Ar-OH), 3307
(N-H), 1675 (C=O), 1505 (C=N), 1382 (C=CAr), 1257 ((C=O)-N), 774 (C-HAr). 1H-NMR (DMSO-d6):
δ 6.98 (H17, d, J = 1.72 Hz), 6.75-6.79 (H14, H15, m), 7.76 (H7, tapparent, J = 7.52 Hz), 7.92 (H8, tapparent, J
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= 7.52 Hz), 8.12 (H6, d, J = 8.02 Hz), 8.18-8.26 (H3, H9, m), 8.63 (H4, d, J = 8.54 Hz), 8.85 (H11, s),
8.87 (OH), 9.02 (OH), 12.42 (NH). 13C-NMR (CDCl3): δ 114.56 (C12), 117.60 (C15), 119.42 (C3),
119.58 (C14, C17), 128.69 (C6), 128.87 (C5), 129.46 (C8), 129.69 (C9), 131.19 (C4), 138.54 (C2), 146.50
(C10), 149.98 (C11), 150.37 (C16), 150.88 (C13), 161.0 (C=O). EIMS: m/z 308.1037 [M + H]+, Calcd for
C17H13N3O3: 308.1035.
4.1.1.3.5. N'-[(1E)-(2,3,4-trihydroxyphenyl)methylidene]quinoline-2-carbohydrazide (6e):
Yield 60% (0.32 mmol, 102.8 mg); dark brown solid, M.p. 219-221°C; IR (cm−1): νmax 3461 (Ar-OH,
N-H), 1636 (C=O), 1501 (C=N), 1480 (C=CAr), 1265 ((C=O)-N), 770 (C-HAr). 1H-NMR (DMSO-d6): δ
6.42 (H16, d, J = 8.32 Hz), 6.79 (H17, d, J = 8.32 Hz), 7.76 (H7, tapparent, J = 7.40 Hz), 7.92 (H8, tapparent, J
= 7.40 Hz), 8.12 (H6, d, J = 8.02 Hz), 8.22 (H9, H3, d, J = 8.43 Hz), 8.50 (OH), 8.62 (H4, d, J = 8.60
Hz), 8.76 (H11, s), 9.49 (OH), 11.59 (OH), 12.38 (NH). 13C-NMR (CDCl3): δ 108.20 (C16), 111.37
(C12), 119.60 (C3), 121.88 (C17), 128.69 (C7), 128.82 (C6), 129.44 (C5), 129.67 (C8), 131.20 (C9),
133.22 (C14), 138.55 (C4), 146.53 (C2), 148.13 (C11), 149.40 (C10), 150.03 (C15), 152.30 (C13), 160.72
(C=O). EIMS: m/z 324.0988 [M + H]+, Calcd for C17H13N3O4: 324.0984.
4.1.1.3.6. N'-[(1E)-(2,3-dihydroxyphenyl)methylidene]quinoline-4-carbohydrazide (7a):
Yield 70% (0.371 mmol, 114.0 mg); brown solid, M.p. 263-267°C; IR (cm−1): νmax 3443 (Ar-OH), 3191
(N-H), 1654 (C=O), 1578 (C=N), 1471 (C=CAr), 1283 ((C=O)-N), 724 (C-HAr). 1H-NMR (DMSO-d6):
δ 6.76 (H16, tapparent, J = 7.84 Hz), 6.89 (H15, dd, J = 7.8, 1.3 Hz), 7.03 (H17, dd, J = 7.8, 1.3 Hz), 7.74
(H3, d, J = 4.2 Hz), 7.78-7.96 (H7, H8, m), 8.13 (H6, d, J = 8.4 Hz), 8.20 (H9, d, J = 8.2 Hz), 8.30 (OH),
8.52 (H11, s), 9.04 (H2, d, J = 4.4 Hz), 10.79 (OH), 12.34 (NH). 13C-NMR (CDCl3): δ 119.20 (C12),
119.82 (C15), 120.16 (C3), 120.32 (C16), 124.61 (C17), 125.67 (C5), 128.30 (C5), 129.87 (C6, C9), 130.63
(C8), 140.18 (C4), 146.03 (C14), 148.30 (C10), 150.13 (C11), 150.74 (C2), 163.10 (C13), 168.76 (C=O).
EIMS: m/z 308.1037 [M + H]+, Calcd for C17H13N3O3: 308.1035.
4.1.1.3.7. N'-[(1E)-(2,4-dihydroxyphenyl)methylidene]quinoline-4-carbohydrazide (7b):
Yield 60% (0.318 mmol, 97.7 mg); yellow solid, M.p. 250-254°C; IR (cm−1): νmax 3381 (Ar-OH), 2856
(N-H), 1632 (C=O), 1509 (C=N), 1466 (C=CAr), 1235 ((C=O)-N), 762 (C-HAr). 1H-NMR (DMSO-d6):
δ 6.35 (H14, d, J = 1.6 Hz), 6.38 (H16, dd, J = 8.5, 1.6 Hz), 7.36 (H17, d, J = 8.5 Hz), 7.71 (H3, d, J = 4.2
Hz), 7.77-7.89 (H7, H8, m), 8.12 (H6, d, J = 8.4 Hz), 8.19 (H9, d, J = 7.6 Hz), 8.42 (H11, s), 9.02 (H2, d,
J = 4.2 Hz), 11.26 (OH), 12.22 (NH). 13C-NMR (CDCl3): δ 103.1 (C14), 108.40 (C16), 110.82 (C12),
120.10 (C3), 124.70 (C5), 125.61 (C7), 128.22 (C8), 129.83 (C9), 130.57 (C6), 131.76 (C17), 140.36 (C4),
148.31 (C10), 150.36 (C11), 150.71 (C2), 159.95 (C15), 161.49 (C13), 162.76 (C=O). EIMS: m/z
308.1035 [M + H]+, Calcd for C17H13N3O3: 308.1035.
4.1.1.3.8. N'-[(1E)-(2,5-dihydroxyphenyl)methylidene]quinoline-4-carbohydrazide (7c):
9

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Yield 62% (0.329 mmol, 101.0 mg); light brown solid, M.p. 270-276°C; IR (cm−1): νmax 3442 (Ar-OH),
1
3339 (N-H), 1661 (C=O), 1585 (C=N), 1466 (C=CAr), 1226 ((C=O)-N), 765 (C-HAr). H-NMR
(DMSO-d6): δ 6.77 (H14, H15, sapparent), 7.05 (H17, s), 7.72 (H3, d, J = 4.4 Hz), 7.78-7.89 (H7, H8, m),
8.12 (H6, d, J = 8.5 Hz), 8.19 (H9, d, J = 8.3 Hz), 8.27 (OH), 8.49 (H11, s), 9.03 (H2, d, J = 4.4 Hz),
10.22 (OH), 12.30 (NH). 13C-NMR (CDCl3): δ 117.64 (C12), 119.43 (C14, C17), 119.90 (C15), 120.14
(C3), 124.60 (C5), 125.71 (C7), 128.22 (C9), 129.93 (C6), 130.60 (C8), 140.36 (C4), 148.33 (C11), 148.65
(C10), 150.36 (C16), 150.73 (C2), 163.10 (C13), 168.83 (C=O). EIMS: m/z 308.1034 [M + H]+, Calcd for
C17H13N3O3: 308.1035.
4.1.1.3.9. N'-[(1E)-(2,3,4-trihydroxyphenyl)methylidene]quinoline-4-carbohydrazide (7d):
Yield 85% (0.450 mmol, 145.6 mg); light yellow solid, M.p. 285-286°C; IR (cm−1): νmax 3496 (Ar-OH),
1
3190 (N-H), 1652 (C=O), 1517 (C=N), 1465 (C=CAr), 1250 ((C=O)-N), 797 (C-HAr). H-NMR
(DMSO-d6): δ 6.42 (H16, d, J = 8.6 Hz), 6.84 (H17, d, J = 8.6 Hz), 7.73 (H3, d, J = 4.3 Hz), 7.79-7.89
(H7, H8, m), 8.12 (H6, d, J = 8.4 Hz), 8.16 (OH), 8.20 (H9, d, J = 8.4 Hz), 8.38 (H11, s), 8.74 (OH), 9.04
(H2, d, J = 4.3 Hz), 11.21 (OH), 12.26 (NH). 13C-NMR (CDCl3): δ 108.3 (C17), 111.16 (C3), 120.15
(C12), 121.72 (C16), 124.70 (C5), 125.71 (C7), 128.20 (C9), 129.91 (C6), 130.60 (C8), 133.2 (C14),
140.31 (C4), 148.0 (C10), 149.52 (C11), 150.74 (C15), 151.45 (C2), 162.73 (C13), 168.25 (C=O). EIMS:
m/z 324.0983 [M + H]+, Calcd for C17H13N3O4: 324.0984.
4.1.1.3.10. N'-[(1E)-(2,4-dihydroxyphenyl)methylidene]isoquinoline-1-carbohydrazide (8):
Yield 65% (0.345 mmol, 105.9 mg); yellow solid, M.p. 260-263°C; IR (cm−1): νmax 3461 (Ar-OH),
1
3268 (N-H), 1665 (C=O), 1511 (C=N), 1460 (C=CAr), 1200 ((C=O)-N), 750 (C-HAr). H-NMR
(DMSO-d6): δ 6.38 (H14, H16, m), 7.29 (H17, d, J = 8.90 Hz), 7.77 (H7, ddd, J = 8.30, 7.07, 1.13 Hz),
7.86 (H8, ddd, J = 8.30, 707, 1.13 Hz), 8.09 (H6, H4 dapparent, J = 8.03 Hz), 8.61 (H3, H11, m), 8.91 (H9,
d, J = 8.51 Hz), 10.16 (OH), 11.55 (OH), 12.34 (NH). 13C-NMR (CDCl3): δ 103.19 (C14), 108.27 (C16),
110.94 (C12), 124.31 (C4), 126.28 (C10), 126.72 (C6), 127.75 (C7), 129.21 (C8), 131.35 (C9), 131.86
(C17), 137.03 (C5), 141.39 (C3), 150.41 (C1), 150.60 (C11), 160.06 (C15), 161.42 (C13), 165.50 (C=O).
EIMS: m/z 308.1035 [M + H]+, Calcd for C17H13N3O3: 308.1035.
4.2. Biological Activity Assays
The compounds were subjected to evaluation of in vitro cytotoxicity on U937 human cells and
leishmanicidal and trypanocidal activities on intracellular amastigotes of L. (V) panamensis and T.
cruzi.
4.2.1. In vitro cytotoxicity
The cytotoxic activity of the compounds was assessed based on the viability of the human
promonocytic cell line U937 (ATCC CRL-1593.2TM) evaluated by the MTT (3-(4,5-dimethylthiazol-2-
10

ACCEPTED MANUSCRIPT
yl)-2,5-diphenyltetrazolium bromide) assay following the metodology described previously [43]. In
brief, cells were grown in 96-well cell-culture dishes at a concentration of 100,000 cells/mL in RPMI-
1640 supplemented with 10% FBS and the corresponding concentrations of the compounds, starting at
200 µg/mL in duplicate. The cells were incubated at 37 °C with 5% CO2 for 72 h in the presence of the
compounds and then the effect of the compounds was determined by measuring the activity of the
mitochondrial dehydrogenase by adding 10 µL/well of MTT solution (0.5 mg/mL) and incubating at 37
°C for 3h. The reaction was stopped by adding 100 µL/well of 50% isopropanol solution with 10%
sodium dodecyl sulfate and incubating for 30 min. Cell viability was determined based on the quantity
of formazan produced according to the intensity of color (absorbance) that registered as optical
densities (O.D) obtained at 570 nm in a ELISA reader plate (Bio-Rad, Hercules, CA, USA). Cultured
cells in the absence of compounds were used as control of viability (negative control), while
meglumine antimoniate and amphotericin B were used as control for cytotoxicity (negative and
positive controls, respectively). Assays were performed in two independent assays with three replicates
per each concentration tested.
4.2.2. In vitro leishmanicidal activity
The activity of compounds was evaluated on intracellular amastigotes of L. (V) panamensis
transfected with the green fluorescent protein gene (MHOM/CO/87/UA140pIR-GFP) [44]. The effect
of each compound was determined according to the inhibition of the infection evidenced by both
decrease of the infected cells and decrease of intracellular parasite load. Briefly, U-937 human cells at a
concentration of 3 × 105 cells/mL in RPMI 1640 and 0.1 ꢀg/mL of PMA (phorbol-12-myristate-13-
acetate) were infected with promastigotes in stationary phase growth in a 15:1 parasites per cell ratio
and incubated at 34 °C and 5% CO2 for 3 h. Cells were washed two times with phosphate buffer
solution (PBS) to eliminate not internalized parasites. Fresh RPMI 1640 1 mL was added and cells
were incubated during 24 h to guarantee multiplication of intracellular parasites.
After 24 h of infection, the culture medium was replaced by fresh culture medium containing each
compound at concentrations 20 ꢀg/mL or lower, (based on the cytotoxicity showed previously by each
compound). After 72 h, the inhibition of the infection progress was determined. Cells were removed
from the bottom plate with a trypsin/EDTA (250 mg) solution. Recovered cells were centrifuged at
1100 rpm during 10 min at 4 °C, the supernatant was discarded and cells were washed with 1 mL of
cold PBS and centrifuged at 1100 rpm during 10 min at 4 °C. The supernatant was discarded and cells
were suspended in 500 ꢀL of PBS and analyzed by flow cytometry (FC 500MPL, Cytomics, Brea, CA,
US) counting 20.000 events. All determinations for each compound and standard drugs were carried
out in triplicate, in two independent experiments [43, 45]. Activity of tested compounds was carried out
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in parallel with infection progress in culture medium alone and in culture medium with amphotericin B
and meglumine antimoniate as leishmanicidal drugs (positive controls). Compounds that showed
growing percentages of inhibition higher than 50% al 20 or less ꢀg/mL were then evaluated at four
additional concentrations to determine the effective concentration 50 (EC50). Here, infected cells were
exposed against each concentration of synthesized compounds during 72 h, then, cells were removed
and tested by flow cytometry as described before.
4.2.3. In vitro trypanocidal activity
Compounds were tested on intracellular amastigotes of T. cruzi, Tulahuen strain transfected with β-
galactosidase gene (donated by Dr. F. S. Buckner, University of Washington) [45]. The activity was
determined according to the ability of the compound to reduce the infection of U-937 cells by T. cruzi.
Similar to the procedure described previously, the trypanocidal activity was initially screened at unique
5
concentration < 20 mg/ml. Briefly, 100 ꢀL of U-937 human cells at a concentration of 2.5 x 10
cells/mL in RPMI-1640, 10% SFB and 0.1 ꢀg/mL of PMA were placed in each well of 96-wells
microplate and then infected with log phase growth epimastigotes in 5:1 (parasites per cell) ratio and
incubated at 34°C, 5% CO2. After 24 hours of incubation, 20 ꢀg/mL of each compound were added to
infected cells. After 72h of incubation, the effect of all compounds on viability of intracellular
amastigotes was determined measuring the β-galactosidase activity by spectrophotometry adding to
each well 100 ꢀM CPRG and 0.1% nonidet P-40. After 3h of incubation, plates were read at 570 nm in
a spectrophotometer (Varioskan™ Flash Multimode Reader - Thermo Scientific, USA) and intensity of
color (absorbance) was registered as optical densities (O.D). Compounds that showed inhibition
percentages higher than 50% were evaluated again at four concentrations selected according to the
LC50 previously obtained for each compound. Infected cells exposed to benznidazol were used as
control for trypanocidal activity (positive control) while infected cells incubated in culture medium
alone were used as control for infection (negative control). Non-specific absorbance was corrected by
subtracting absorbance (O.D) of the blank. Determinations were done by triplicate in at least two
independent experiments [46].
4.2.4. Statistical Analysis
Cytotoxicity was determined according to viability and mortality percentages obtained for each
isolated experiment (compounds, amphotericin B, meglumine antimoniate and culture medium alone).
The results were expressed as 50 lethal concentrations (LC50) that corresponds to the concentration
necessary to eliminate 50% of cells and calculated by Probit analysis [47]. Percentage of viability was
calculated by Equation 1, where the O.D of control, corresponds to 100% of viability. In turn, mortality
percentage corresponds to 100%–% viability:
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% Viability = (O.D Exposed cells) / (O.D Control cells) × 100
(1)
The degree of toxicity was graded according to the LC50 value using the following scale: high
cytotoxicity: LC50 < 100 ꢀg/mL; moderate cytotoxicity: LC50 > 100 to < 200 ꢀg/mL and potentially
non-cytotoxicity: LC50 > 200 ꢀg/mL.
Leishmanicidal activity was determined according to the percentage of infected cells and parasite
load obtained for each experimental condition by flow cytometry. The percentage of infected cells was
determined as the number of positive events by double fluorescence (green for parasites and red for
cells) using dotplot analysis. On the other hand, the parasitic load was determined by analysis of mean
fluorescence intensity (MFI) of fluorescent parasites [43]. The parasite inhibition was calculated by
equation 2, where the MFI of control, corresponds to 100% of parasites. In turn, inhibition percentage
corresponds to 100% – % Parasites. Results of leishmanicidal activity were expressed as EC50
determined by the Probit method [47]:
% Parasite = (MFI Exposed parasites) / (MFI Control parasites) × 100
(2)
Similarly, trypanocidal activity was determined according to the percentage of infected cells and
parasite load obtained for each experimental condition by colorimetry. The parasite inhibition was
calculated by equation 3, where the O.D of control corresponds to 100% of parasites. In turn, inhibition
percentage corresponds to 100% – % Parasites. Results of trypanocidal activity were also expressed as
EC50 determined by the Probit method [47]:
% Parasite = (O.D Exposed parasites) / (O.D Control parasites) × 100
(3)
The leishmanicidal or trypanocidal activities were graded according to the EC50 value using the
following scale: High activity: EC50 < 20 ꢀg/mL, moderate activity: EC50 > 20 to < 50 ꢀg/mL;
potentially non activity: EC50 > 100 ꢀg/mL.
The selectivity index (SI), was calculated by dividing the cytotoxic activity and the leishmanicidal
or trypanocidal activity using the following formula: SI = CL50/CE50. Cytotoxic compound: LC50<100
µg/mL.
Acknowledgments
The authors thank Universidad de Antioquia (grant CODI IN656CE and CIDEPRO) for financial
support.
Conflict of interest
The authors declare no conflict of interest.
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Figure and Scheme legends
Figure 1. Structures of some hydrazones with antiprotozoal activity.
Figure 2. Design of quinoline-hydrazone hybrids as antiprotozoal agents.
Figure 3. 4-quinoline and isoquinoline hydrazone derivatives.
Scheme 1. Synthetic pathway to quinoline-hydrazone hybrids.
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Table 1. In vitro cytotoxicity and antiprotozoal activity of hydrazones
Cytotoxicity
(LC50) a
Inhibition intracellular amastigotes
growth (%)
Compound
L. (V)
T. cruzi
panamensis
6a
6b
6c
6d
6e
7a
7b
7c
7d
8
16.3 + 2.2, 56.0
30.6 + 5.3, 99.6
3.6 + 0.3, 11.7
48.9 + 3.8, 159.1
71.5 + 4.5, 221.2
14.6 + 1.0, 47.5
10.6 + 2.1, 34.5
>200.0, >650.8
112.2 + 4.0, 347.3
8.8 + 1.5, 28.6
495.9 + 55,6
16.8 + 5.0 b
75.7 + 14.1 b
64.7 + 5.6 e
64.0 + 8.2 b
68.2 + 2.1 b
47.4 + 1.2 c
6.4 + 1.2 d
50.4 + 1.4 d
31.0 + 2.0 b
41.5 + 6.0 d
24.0 + 3.0 b
36.1 + 1.6 b
27.4 + 3.2 b
27.7 + 1.7 c
20.7 + 3.6 b
15.7 + 0.8 b
24.1 + 3.7 c
NAg
26.1 + 3.7 b
21.3 + 3.5 b
62.6 + 7.8 d
79.4 + 2.1 c
Meglumine
antimoniate
Amphotericin B
42.1 + 2.0, 45.6
76.0 + 3.0 f
NAg
Benznidazole
179.0 + 4.2, 687.7
NAg
87.6 + 8.4 b
a
Data represent mean value +/- standard deviation; LC50: Lethal Concentration 50 in
b
c
d
µg/mL, µM; Dose employed 20 µg/mL; Dose employed: 10 µg/mL; Dose employed:
e
f
g
5.0 µg/mL; Dose employed: 1.0 µg/mL; Dose employed: 0.05 µg/mL;
applicable.
NA: Not

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Table 2. Dose-response antileishmanial and antitrypanosomal activities of
hydrazones and selectivity
a
Compound
EC50
IS b
Antileishmanial
6b
6.5 ± 0.8, 21.2
0.8 ± 0.0, 2.6
4.7
4.5
6c
6d
37.2 ± 3.7, 121.1
15.4 ± 2.5, 47.6
3.4 ± 0.6, 11.1
6.3 ± 0.9
2.8
6e
4.6
8
2.6
Meglumine antimoniate
78.6
1052.5
Amphotericin B
0.04 ± 0.01, 0.04
Antitrypanosomal
6a
1.4 ± 0.3, 4.8
6.6 ± 0.3, 4.6
11.6
0.5
6c
7b
20.8 ± 0.5, 67.7
10.5 ± 1.8, 40.3
0.5
Benznidazole
17.0
Data represent the mean value +/- standard deviation; a EC50: Effective Concentration
50 in µg/mL, µM; b IS: Index of Selectivity = LC50 / EC50.

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Synthesis, Leishmanicidal, Trypanocidal and Cytotoxic Activity of
Quinoline-Hydrazone Hybrids
Highlights
1. We synthesized ten quinoline hydrazones with good yields
2. Five of the compounds obtained were active against L. (V) panamensis and three of them against T.
cruzi
3. The presence of 2-substituted quinoline o isoquinolinic core increase the leishmanicidal activity
4. Hydroxyl group in positions 3 and 4 of the aromatic ring is essential for activity.
Juan Carlos Coa 1, Wilson Castrillón L1, Wilson Cardona G1 *, Miguel Carda 2, Victoria Ospina3,
July Andrea Muñoz3, Iván D. Vélez 3, Sara M. Robledo 3
1
Chemistry of Colombian Plants, Institute of Chemistry, Exact and Natural Sciences School,
University of Antioquia-UdeA; Calle 70 No. 52-21, A.A 1226, Medellín, Colombia; e-mail:
juancoa2@gmail.com; w.castrillon@hotmail.com
2
Department of Inorganic and Organic Chemistry, Jaume I University, E-12071 Castellón, Spain; e-
mail: mcarda@qio.uji.es
3
PECET-Medical Research Institute, School of Medicine, University of Antioquia-UdeA. Calle 70
No. 52-21, A.A 1226, Medellín, Colombia;
e-mail: sara.robledo@udea.edu.co; ivan.velez@udea.edu.co; victoriaospina@hotmail.com;
julyandru37@gmail.com.
* Author to whom correspondence should be addressed; e-mail: wilson.cardona1@udea.edu.co;
phone: +574-219-5653; fax: +574-233-0120.

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Synthesis, Leishmanicidal, Trypanocidal and Cytotoxic Activity of Quinoline-Hydrazone
Hybrids
Juan Carlos Coa 1, Wilson Castrillón L1, Wilson Cardona G1 *, Miguel Carda 2, Victoria Ospina3,
July Andrea Muñoz3, Iván D. Vélez 3, Sara M. Robledo 3
1
Chemistry of Colombian Plants, Institute of Chemistry, Exact and Natural Sciences School,
University of Antioquia-UdeA; Calle 70 No. 52-21, A.A 1226, Medellín, Colombia; e-mail:
juancoa2@gmail.com; w.castrillon@hotmail.com
2
Department of Inorganic and Organic Chemistry, Jaume I University, E-12071 Castellón, Spain; e-
mail: mcarda@qio.uji.es
3
PECET-Medical Research Institute, School of Medicine, University of Antioquia-UdeA. Calle 70
No. 52-21, A.A 1226, Medellín, Colombia;
e-mail: sara.robledo@udea.edu.co; ivan.velez@udea.edu.co; victoriaospina@hotmail.com;
julyandru37@gmail.com.
* Author to whom correspondence should be addressed; e-mail: wilson.cardona1@udea.edu.co;
phone: +574-219-5653; fax: +574-233-0120.

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1H, 13C NMR and MS spectra

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