Systematic Search for Benzimidazole Compounds and Derivatives with Antileishmanial Effects

Molecular Diversity https://doi.org/10.1007/s11030-018-9830-7

ORIGINAL ARTICLE

Systematic search for benzimidazole compounds and derivatives with antileishmanial effects

Juan Carlos Sánchez-Salgado1 · Pablo Bilbao-Ramos2 · María Auxiliadora Dea-Ayuela3 · Francisco Hernández-Luis4 · Francisco Bolás-Fernández2 · José L. Medina-Franco4 · Yareli Rojas-Aguirre4,5,6

Received: 3 September 2017 / Accepted: 26 April 2018 © Springer International Publishing AG, part of Springer Nature 2018

1 Abstract 1 2 Leishmaniasis is a neglected tropical disease that currently affects 12 million people, and over 1 billion people are at risk 3 of infection. Current chemotherapeutic approaches used to treat this disease are unsatisfactory, and the limitations of these 4 drugs highlight the necessity to develop treatments with improved efficacy and safety. To inform the rational design and Author Proof 5 development of more efficient therapies, the present study reports a chemoinformatic approach using the ChEMBL database 2 6 to retrieve benzimidazole as a target scaffold. Our analysis revealed that a limited number of studies had investigated the 3 7 antileishmanial effects of benzimidazoles. Among this limited number, L. major was the species most commonly used to 8 evaluate the antileishmanial effects of these compounds, whereas L. amazonensis and L. braziliensis were used least often in the 9 reported studies. The antileishmanial activities of benzimidazole derivatives were notably variable, a fact that may depend on 10 the substitution pattern of the scaffold. In addition, we investigated the effects of a benzimidazole derivative on promastigotes 11 and amastigotes of L. infantum and L. amazonensis using a novel fluorometric method. Significant antileishmanial effects were 12 observed on both species, with L. amazonensis being the most sensitive. To the best of our knowledge, this chemoinformatic 13 analysis represents the first attempt to determine the relevance of benzimidazole scaffolds for antileishmanial drug discovery 14 using the ChEMBL database. The present findings will provide relevant information for future structure–activity relationship 4 15 studies and for the investigation of benzimidazole-derived drugs as potential treatments for leishmaniasis.

16 Keywords Benzimidazoles · Chemoinformatics · Leishmania · Molecular scaffold

Introduction 17 Electronic supplementary material The online version of this article (https://doi.org/10.1007/s11030-018-9830-7) contains supplementary Leishmania protozoan hemoflagellate parasites are transmit- 18 material, which is available to authorized users. ted via the bite of the infected female phlebotomine sandfly 19 B Yareli Rojas-Aguirre and cause a group of neglected tropical diseases that are 20 [email protected] collectively known as leishmaniasis. These include a wide 21 range of clinical manifestations that are determined by the 22 1 Instituto de Medicina Molecular y Ciencias Avanzadas, Rayo 11 Jardines del Pedregal, Álvaro Obregón, 01900 Mexico infecting species and the immune response of the human host 23 City, Mexico [1]. Leishmaniasis is therefore classified into three groups: 24 2 Departamento de Parasitología, Facultad de Farmacia, (a) visceral leishmaniasis, (b) mucocutaneous leishmaniasis, 25 Universidad Complutense de Madrid, Plaza Ramón y Cajal and (c) cutaneous leishmaniasis [2]. This group of diseases 26 s/n, 28040 Madrid, Spain affects approximately 12 million people in about 98 coun- 27 3 Departamento de Farmacia, Universidad CEU Cardenal tries. It is estimated that over 1 billion people are at risk, 28 Herrera, s/n, 46113 Moncada, Valencia, Spain uncorrectedindicating that this is one proof of the neglected tropical diseases 29 4 Facultad de Química, Departamento de Farmacia, Universidad with the highest disease burden [3–5]. 30 Nacional Autónoma de México, 04510 Mexico City, Mexico 5 Cátedra Conacyt-Laboratorio Nacional de Manufactura Aditiva y Tomografía Computarizada, Centro de Ciencias 6 Present Address: Instituto de Investigaciones en Materiales, Aplicadas y Desarrollo Tecnológico, Universidad Nacional Universidad Nacional Autónoma de México, 04510 Mexico Autónoma de México, 04510 Mexico City, Mexico City, Mexico

123

Journal: 11030 MS: 9830 TYPESET DISK LE CP Disp.:2018/5/3 Pages: 12 Layout: Large Molecular Diversity

31 No vaccine exists for the prevention of leishmaniasis, and mastigote found in the sandfly vector and the intracellular 44 32 current treatments rely on chemotherapeutics. Although sev- amastigote, which is present in macrophages and causes the 45 33 eral drugs are used to treat the infection, these treatments are clinical symptoms [9]. Therefore, an antileishmanial com- 46 34 limited by their severe toxicity, poor or variable efficacy, and pound needs to enter the host macrophage and eliminate the 47 35 emerging drug resistance; some drugs are also expensive and parasites, without damaging the host macrophage. As shown 48 36 this limits their availability in some neglected geographical in Table 1, current antileishmanial drugs have a broad diver- 49 37 regions [2,6,7]. sity of chemical core scaffolds, which are associated with 50 38 The development of new antileishmanial agents is chal- different mechanisms of action. 51 39 lenging because of the complex biology of the Leishmania Sangshetti et al. [11] reviewed the progress of antileishma- 52 40 parasite. First, drug efficacy varies depending on the parasite nial drug discovery, focusing on the chemical compositions 53 41 species, the clinical symptoms, and even the geographi- of new classes of synthetic and naturally occurring antileish- 54 42 cal region [7,8]. Second, the parasite life cycle is a factor manial agents. This analysis identified molecules belonging 55 43 because Leishmania alternates between the extracellular pro- to a wide variety of chemical families. This diversity means 56

Table 1 Current treatments for leishmaniasis

Mechanism of Name Chemical structure Uses Advantages Limitations action Author Proof

Efficacy ranges from 35- Pentavalent 95%. antimonials: Low cost. Drug resistance. sodium Not clearly VL and Can be used in Severe kidney and liver stibogluconate, elucidated. CL combination with toxicity; pancreatitis; meglumine amphotericin B tachycardia, fibrillation, and antimoniate cardiac arrhythmias Forms complexes with ergosterol (a major parasite membrane Efficacy of 95- Requires hospitalization component). 100% because of renal toxicity, Consequently, Effective when VL, CL, myocarditis, and reactions at Amphotericin B membrane resistance to and MCL the infusion site. permeability pentavalent Liposomal form: renal increases, aqueous antimonials is toxicity and high cost pores are formed, the observed ionic balance is altered, and the parasite dies

Drug resistance The primary mode of Efficacy of 70- Renal toxicity, myocarditis, action remains 80% fever, hypotension, Pentamidine unknown. VL Could be used in irreversible insulin- Possible binding with combination with dependent diabetes mellitus, kinetoplastid DNA other drugs death Inhibition of Efficacy of 94- phosphatidylcholine VL and 97% biosynthesis and variable Renal and hepatic toxicity Miltefosine Highly potent alteration of efficacy Teratogenicity Administered phospholipid and in CL orally sterol composition Possible alteration of membrane fluidity, interaction with VL and ribosomes, Highly hepatotoxic and CL. More Paromomycin interference with Low cost ototoxic; abdominal uncorrectedeffective proof mitochondrial cramps, diarrhea for CL membrane potential, and inhibition of respiration

The information was extracted from the following Refs.[2,8,10] VL visceral leishmaniasis, CL cutaneous leishmaniasis, MCL mucocutaneous leishmaniasis

123

Journal: 11030 MS: 9830 TYPESET DISK LE CP Disp.:2018/5/3 Pages: 12 Layout: Large Molecular Diversity

57 that it is difficult to establish an overall relationship between ously [38]. The present study based the scaffold analysis and 107 58 chemical structure and antileishmanial activity. its distribution in the database on specific molecular chemo- 108 59 Chemoinformatic approaches can be used to analyze and types, an approach previously described by Medina-Franco 109 60 integrate information related to the physicochemical proper- et al. [39]. Hence, in the present work the molecular chemo- 110 61 ties of compounds and their biological activities, in order to types, also called cyclic systems, were defined as a set of rings 111 62 identify novel drug candidates [12–14]. Chemoinformatics plus the chains of atoms that linked them to one another. To 112 63 has been applied to aid antiparasitic drug discovery [15–17], isolate the scaffold, all the substituent groups, with the excep- 113 64 including the search for potential antileishmanial compounds tion of endocyclic carbonyls and imines, were removed from 114 65 through distinct approaches [18–20]. the rings and linkers. Heteroatoms were retained, whereas 115 66 The ChEMBL bioactivity database is administered by the all hydrogen atoms attached to them were considered side 116 67 European Molecular Biology Laboratory in the UK (http:// chains and therefore deleted. The Molecular Equivalence 117 68 www.ebi.ac.uk/chembl/). This free public online repository Indices (MEQI) program (version 2.41) [40] was used to 118 69 provides large amounts of information on the relationships obtain the specific cyclic system, which had a five-character 119 70 between the physicochemical properties of molecules and alphanumeric chemotype identifier that was present on each 120 71 their molecular targets [21,22]. The inclusion of user feed- compound in the subsets obtained from ChEMBL. 121 72 back has allowed ChEMBL to expand over time, and it has 73 recently included the direct deposition of data relating to

74 neglected diseases [23]. Biological assays 122

Author Proof 75 The present study aimed to identify potential antileish-

76 manial scaffolds by mining the ChEMBL database. We Model benzimidazole compound 123 77 focused on the benzimidazole scaffold because this is a major

78 documented pharmacophore in drug discovery [24] and ben- We used 5,6-dichloro-2-(trifluoromethyl)-1H-benzimidaz- 124 79 zimidazole derivatives have been widely used as antiparasitic ole (G2) as a model compound with a benzimidazole scaf- 125 80 drugs in the treatment of helminthic and protozoan infections, fold to assess antileishmanial activity. This compound was 126 81 where they primarily act by inhibiting tubulin polymeriza- previously designed and synthesized by our research group 127 82 tion [25,26]. The α-, β-, and γ -tubulins are essential for as part of a 2-(trifluoromethyl)-1H-benzimidazole deriva- 128 83 microtubule formation and play a key role in the growth tives series. G2 showed significant activity when evaluated 129 84 and differentiation of kinetoplastid protozoa [27–30]. For this against L. mexicana promastigotes. Although it was not the 130 85 reason, tubulin is a significant target in the antiparasitic and most active among that series, we selected it because of the 131 86 antileishmanial drug discovery fields [31–33]. simplicity of its structure, in comparison with the other active 132 87 There has been increasing interest in exploring the compounds that contained bulky substituents at the 5 and 6 133 88 antileishmanial potential of benzimidazoles [34–37]. For this positions. We therefore considered G2 as a starting point [34]. 134 89 reason, it is important to start analyzing the benzimidazole 90 scaffold content to identify representative compounds dis- Parasites 135 91 playing activities against particular Leishmania species or 92 all the species to contribute to further structure–activity rela- Two Leishmania species were used for the following exper- 136 93 tionship studies. iments: L. amazonensis (MHOM/BR/79/Maria) was kindly 137 94 To ascertain the antileishmanial potential of benzimida- provided by Dr. Alfredo Toraño (Instituto de Salud Carlos 138 95 zole derivatives, we mined the ChEMBL database system- III, Madrid, Spain), and an autochthonous strain of L. infan- 139 96 atically to identify benzimidazole scaffolds with activities tum (MCAN/ES/92/BCN83), isolated from an asymptomatic 140 97 against diverse species of Leishmania and their relevance for dog in the Priorat region (Catalonia, Spain), was generously 141 98 these species. In addition, we synthesized and determined the provided by Professor Montserrat Portús (Universidad de 142 99 activities of a benzimidazole derivative, namely 5,6-dichloro- Barcelona). Promastigotes of both species were cultured at 143 100 2-(trifluoromethyl)-1H-benzimidazole (G2), against the pro- ◦ 26 C in 25-mL culture flasks containing Schneider’s insect 144 101 mastigotes and intra-macrophage amastigotes of two Leish- medium (Sigma) supplemented with 20% heat-inactivated 145 102 mania species. fetal bovine serum (Sigma), 100U/mL penicillin, and 100 146 uncorrectedµg/mL streptomycin (Sigma). proof 147 103 Materials and methods

148 104 Chemical informatics Effect of G2 on Leishmania promastigotes

105 A range of methods can be employed to derive the scaffold The effect of G2 on promastigotes was analyzed using the 149 106 of a molecule in a systematic manner, as described previ- procedure reported by Bilbao-Ramos et al., with minor mod- 150

123

Journal: 11030 MS: 9830 TYPESET DISK LE CP Disp.:2018/5/3 Pages: 12 Layout: Large Molecular Diversity

151 ifications [41]. Briefly, serial dilutions of G2 (40, 20, 6, 5, Microscopy studies 198 152 2.5, 1.2, 0.6, 0.3 µM) were prepared using fresh culture 153 medium. The parasites were seeded in 96-well microplates Confocal laser fluorescence microscopy 199 5 154 (2.5 × 10 promastigotes/well) prior to adding the indi- ◦ 6 155 cated concentration of G2 and incubating at 26 C for 48 h. Promastigotes of L. infantum (10 × 10 parasites) were incu- 200 156 Resazurin dye solution (20µL of 2.5mM) was then added, bated in Schneider’s insect medium containing G2 at its IC50 201 157 and the plates were incubated for 3h. Fluorescence intensity of 8.6 µM for 48 h. The culture medium was then removed, 202 158 was then measured using an Infinite 200 (Tecan i-Control) and the promastigotes were washed with phosphate-buffered 203 159 fluorometer at an excitation wavelength of 535 nm and an saline (PBS) containing 0.25mM MgCl2 and 0.35mM CaCl2 204 160 emission wavelength of 590nm. These readings were used [43]. Thereafter, the samples were incubated with a rab- 205 161 to calculate the growth inhibition rate, which was expressed bit anti-β-tubulin primary antibody (Thermo Fisher Scien- 206 162 as the 50% inhibitory concentration (IC50) and calculated tific) (1:100 dilution in PBS containing MgCl2 and CaCl2) 207 ◦ 163 using SPSS 17.0 Statistics Software. Miltefosine (Sigma) overnight at 4 C. Subsequently, the cells were washed 208 2+ 2+ 164 was used as reference drug, and all tests were performed three times with PBS–Mg –Ca prior to exposure to a 209 165 in triplicate. secondary antibody (goat anti-rabbit IgG FITC-conjugated, 210 2+ 2+ ◦ 1:100 in PBS–Mg –Ca ). Cells were maintained at 37 C 211 2+ 2+ 166 Effect of G2 on Leishmania amastigotes for 1h and then washed with PBS–Mg –Ca . Slides were 212 air-dried in darkness at room temperature and then observed 213

Author Proof 167 The experiments involving L. amazonensis were performed under a Leica DM-IRE2 inverted microscope. Confocal 214 168 using the fluorometric method reported by Bilbao-Ramos et microscopy images were acquired using LCS 2.6 software. 215 169 al. [42], with some modifications. The experiments involv- 170 ing L. infantum amastigotes were conducted for the first Light microscopy 216 171 time, although these experiments were also based on the pro- 172 tocol reported by Bilbao-Ramos et al. [42]. Briefly, J774 These studies were performed in 8-well Lab-Tek cham- 217 173 macrophages were grown in RPMI-1640 medium. These ber slides (Nunc) using L. amazonensis and L. infantum. 218 4 174 cells (5 × 10 cells/well) were seeded in 96-well microplates Macrophage infection was developed as described above, 219 5 175 and then infected with 5 × 10 promastigotes/well. The and the infected macrophages were exposed to G2 at 10 220 176 macrophages infected with L. infantum were incubated for µg/mL for 48h. The cells were then fixed with methanol 221 ◦ 177 48 h at 37 C, whereas those infected with L. amazonen- and stained with 10% Giemsa (200 µL/well). After 15min, 222 ◦ 178 sis were incubated at 33 C for 24 h. The temperature of the samples were washed and air-dried at room temperature. 223 ◦ 179 both cultures was then adjusted to 37 C. After 24h, the cul- Before the microscopic analysis, the upper structure of the 224 180 ture medium was removed and the cells were washed with chamber was removed, and the coverslips were placed and 225 181 RPMI-HEPES to eliminate the non-internalized promastig- sealed with DPX. 226 182 otes. Thereafter, the infected cells were exposed to 100 µL 183 of G2 at different concentrations (200, 100, 50, 25, 12.5, ◦ 184 6, 3, 1.5 µM) in RPMI-1640 for 48h at 37 C. The cul- Results and discussion 227 185 ture medium was then removed by centrifugation at 3500 186 rpm for 5min (Centrifuge 5403, Eppendorf), and a lysis Chemoinformatic analysis 228 187 solution (0.01% sodium dodecyl sulfate in RPMI-HEPES) 188 was added to the pellet. After 20min, the treated cells were The workflow used to systematically retrieve benzimidazole 229 ◦ 189 centrifuged (3500 rpm, 5min, 4 C) and the supernatants scaffolds from the ChEMBL database is shown in Fig. 1. 230 190 were replaced by 200 µL of Schneider’s insect medium. ◦ 191 Finally, the plates were incubated at 26 C for 3days to allow Antileishmanial data retrieval 231 192 the transformation of viable amastigotes to promastigotes. 193 The proliferation and viability of Leishmania promastig- We conducted an initial exploratory search for molecules 232 194 otes, expressed as the IC50, was then determined using the in ChEMBL that had been reported to show antileishma- 233 195 resazurin method described above. Miltefosineuncorrected was used nial activity. This also allowed proof us to identify the Leishmania 234 196 as a reference, and all experiments were performed three species associated with the highest number of records. An 235 197 times. initial dataset including 6903 chemical entities with activ- 236 ity against ten Leishmania species was retrieved from the 237 database (Supplementary File 1, Table S1). L. donovani, L. 238 infantum, and L. amazonensis were the most commonly stud- 239 ied species, with 3472, 1681, and 716 active compounds, 240

123

Journal: 11030 MS: 9830 TYPESET DISK LE CP Disp.:2018/5/3 Pages: 12 Layout: Large Molecular Diversity

Fig. 1 Workflow used for identification of benzimidazole scaffolds Author Proof scaffolds for L. infantum were thus more diverse (58.56%) 254 than those for L. amazonensis (28.39%) (Fig. 3b). 255

Chemotype analysis 256

This analysis revealed that single aromatic ring compounds 257 were the most prevalent in entries associated with both 258 L.amazonensis andL.infantum. Regarding L. amazonensis, 259 it was found that the bioactive molecules mostly contained 260 cyclic systems with 2–5 aromatic or heterocyclic rings. Some 261 of these were linked by a long unsaturated carbon chain, 262 resembling the structure of pentamidine (Supplementary File 263 2, Fig S1). However, there were no benzimidazoles within 264 this dataset. 265 Fig. 2 ChEMBL database entries associated with effects on the indi- With respect to L. infantum, the active compounds had 266 cated Leishmania species different structural features and were more complex (Sup- 267 plementary File 2, Fig. S2). These scaffolds included shorter 268 241 respectively (Fig. 2). These values reflected the fact that chemotypes with either heterocyclic or aromatic systems, 269 242 L. donovani and L. infantum, which cause lethal visceral with a considerable number of acyclic compounds (1.72%). 270 243 leishmaniasis, have been prioritized by the scientific research Chemotypes including single cyclic or bridged alkanes, cor- 271 244 community. responding to cyclohexane or adamantane structures, respec- 272 245 This initial dataset was then searched to identify com- tively, were present; a cyclic chemotype containing selenium 273 246 pounds with a benzimidazole scaffold. atoms was also identified. Interestingly, a cyclic system with 274 a benzimidazole moiety (chemotype ID NM7HR) was iden- 275 247 Chemotype assessment tified within this group with a frequency of 0.65%. Four 276 uncorrectedadditional cyclic systems proof containing the benzimidazole moi- 277 248 The total number of cyclic chemotypes was analyzed for each ety, albeit at lower frequencies were detected. Therefore, five 278 249 species using MEQI, which has previously been used suc- cyclic chemotypes containing benzimidazole were found in 279 250 cessfully to classify several compound collections [44–46]. the L. infantum dataset (Fig. 4). Interestingly, these were 280 251 AsshowninFig.3a, the 1681 entries associated with L. infan- all N-ferrocenylmethyl, N’-methyl-2-substituted benzimi- 281 252 tum included more chemotypes (1105) than the 716 chemical dazoles and benzimidazolium iodide salts belonging to a 282 253 entries relating to L. amazonensis (249 chemotypes). The chemical series that included 26 compounds [47]. 283

123

Journal: 11030 MS: 9830 TYPESET DISK LE CP Disp.:2018/5/3 Pages: 12 Layout: Large Molecular Diversity

entries; these were associated with L. donovani (n = 40), L. 303 major (n = 39), and L. mexicana (n = 20). 304 In the case of L. donovani, eight scaffolds with benz- 305 imidazole as the main system were identified. Interestingly, 306 the structural features of this group mostly corresponded to 307 bis-benzimidazole systems linked by a long chain of carbon 308 atoms, resembling the structure of pentamidine (Supplemen- 309 tary File 2, Fig. S4a). In contrast, five scaffolds corresponding 310 to benzofuran, benzothiazole, or 7-chloroquinoline main het- 311 erocyclic systems were found to contain benzimidazole as a 312 substituent (Supplementary File 2, Fig. S4b). The benzimida- 313 zole heterocycle substituted at the 1, 2, 5, and 6 positions was 314 the scaffold detected for both L. major and L. mexicana.For 315 the latter species, an additional scaffold comprising a hybrid 316 system from benzimidazole and pentamidine was also iden- 317 tified (Supplementary File 2, Fig. S5). 318

Search of external sources 319 Author Proof

Although ChEMBL is a high-quality public database, it 320 can contain gaps that can be addressed by additional lit- 321 erature searching [48]. To this end, databases of the peer- 322 reviewed literature were searched for publications report- 323 ing benzimidazoles, beyond those already identified using 324 ChEMBL. Three publications were found that reported the 325 effects of benzimidazole analogs on Leishmania species. 326 One of these publications reported the synthesis of gold 327 complexes using benzimidazole moieties as ligands. These 328 Fig. 3 Chemotypes and scaffold diversity determined by MEQI. a Total compounds (4 entries) showed significant activities against 329 number of chemotypes and b scaffold diversity associated with L. ama- zonensis and L. infantum promastigotes and amastigotes of L. major, L. amazonen- 330 sis, and L. braziliensis (Supplementary File 2, Fig. S6) 331 [49]. Thirty-one entries relating toL. donovani were iden- 332 tified; these reported a series of 2,3-dihydroimidazo[1,2- 333 284 Analysis of benzimidazole chemotypes α]benzimidazole analogs, some of which showed promising 334 antiparasitic activity against the two biological stages of this 335 285 The analysis described above identified five chemotypes parasite with IC50 values of 3.05–5.29 µM (Supplementary 336 286 containing benzimidazoles in the L. infantum dataset. We File 2, Fig. S6b) [50]. In addition, 2-aryl- and 5-nitro-2- 337 287 were curious about the low frequency of these scaffolds and arylbenzimidazole derivatives (31 entries) were effective 338 288 therefore modified our search criteria to find cases where ben- against L. major promastigotes (Supplementary File 2, Fig. 339 289 zimidazole was present as the main ring or as a substituent. S6c) [51]. 340 290 This approach identified 13 additional cyclic chemotypes We combined these additional findings with those iden- 341 291 containing benzimidazoles (corresponding to 30 derivatives). tified in ChEMBL. Figure 5 shows the total number of 342 292 Eight chemotypes with benzimidazole as the main system benzimidazole-containing molecules identified, and the Leish- 343 293 were identified. Within this group, two bis-benzimidazole mania species in which they were evaluated. These findings 344 294 systems were found, whereas the rest of the scaffolds were demonstrate that benzimidazole scaffold bioactivity has 345 295 1,2-disubstituted benzimidazoles. Five of the chemotypes did mostly been studied using L. major, followed by L. dono- 346 296 not include benzimidazole as the main scaffold;uncorrected these were vani; these species cause proof the cutaneous and visceral forms of 347 297 all 2-aryl substituted benzimidazoles (Supplementary File 2, the disease, respectively. In contrast, the effects of benzimi- 348 298 Fig. S3). In this manner, 56 benzimidazole derivatives were dazoles were seldom investigated using L. amazonensis and 349 299 identified as being active against L. infantum. This approach L. braziliensis. 350 300 yielded no results for L. amazonensis, but its application to In total, 235 benzimidazole scaffolds evaluated against 351 301 the datasets relating to the other eight Leishmania species Leishmania species were retrieved. A total of 127 struc- 352 302 recorded in ChEMBL identified a total of 99 benzimidazole tures (54%) showed activity against visceral leishmaniasis 353

123

Journal: 11030 MS: 9830 TYPESET DISK LE CP Disp.:2018/5/3 Pages: 12 Layout: Large Molecular Diversity Author Proof

Fig. 4 Benzimidazole scaffold-containing chemotypes identified for L. infantum

Fig. 6 Chemical structure of G2

Fig. 5 Frequency of benzimidazole scaffolds for each Leishmania Benzimidazole antileishmanial activity 362 species To explore benzimidazole bioactivity directly, we per- 363 formed biological assays focusing on L. amazonensis (cuta- 364 354 (L. donovani, L. infantum), 104 molecules (44.3%) were neous leishmaniasis) and L. infantum (visceral leishmani- 365 355 studied in species associated with cutaneousuncorrected leishmania- asis). Our research group proof previously synthesized a num- 366 356 sis (L. major, L. mexicana, L. amazonensis), and only 4 ber of benzimidazole compounds and found some activ- 367 357 benzimidazole derivatives (1.7%) were evaluated against ity against a broad spectrum of parasites, ranging from 368 358 mucocutaneous leishmaniasis (L. braziliensis). These results helminths to protozoans. Within these molecules, G2 (Fig. 6) 369 359 reflect the fact that interest in discovering novel chemother- showed activity against L. mexicana promastigotes [34], and 370 360 apeutics has focused on the visceral form of the dis- we therefore investigated its effects on other Leishmania 371 361 ease. species. 372

123

Journal: 11030 MS: 9830 TYPESET DISK LE CP Disp.:2018/5/3 Pages: 12 Layout: Large Molecular Diversity

Table 2 Antileishmanial Compound IC (µM) activity of G2 50 Promastigotes Amastigotes L. amazonensis L. infantum L. amazonensis L. infantum

G2 4.11 8.63 9.00 15.79 Miltefosine 9.56 7.42 3.21 4.6

373 Activity against promastigotes and amastigotes In particular, a bulky group in position 1 might influence 416 antileishmanial activity, and positions 5 and 6 could also 417 374 In L. amazonensis promastigotes, G2 showed greater antileish- play important roles. These findings provide a starting point 418 375 manial activity than miltefosine. In L. infantum promastig- for further studies of the relationship between benzimida- 419 376 otes, the activity of G2 was comparable to that of miltefosine zole structure and antileishmanial activity. These preliminary 420 377 (Table 2). results could inform further exploration of the benzimidazole 421 378 Although Leishmania promastigote screening provides scaffold in the design of novel compounds, or the repo- 422 379 valuable preliminary information, this assay could generate sitioning of existing benzimidazole-derived drugs, for the 423 380 false positives. The amastigote is more clinically relevant treatment of L. amazonensis infections. 424

Author Proof 381 because it infects the mammalian host. Previous studies have Howarth and Hanlon [47] reported the synthesis of 26 425 382 identified a poor correlation between the biological activities benzimidazolium derivatives that were evaluated against L. 426 383 of compounds in these two stages [52,53], and evaluation of infantum; however, they did not indicate whether the assays 427 384 amastigote effects is therefore essential. The method used to were performed on promastigotes and no technical details 428 385 identify activity against amastigotes is worth careful consid- were provided. It is therefore difficult to compare their work 429 386 eration. Axenic amastigote cultures have provided a useful with our results directly, although our findings showed that 430 387 tool for high-throughput screening studies. Nevertheless, this G2 significantly affected L. infantum promastigotes and 431 388 method has some limitations because it does not reflect many amastigotes, with IC50 values below 25 µM. 432 389 aspects of intracellular parasite development [54]. In the 390 present study, we employed a novel fluorometric assay of 391 intra-macrophage amastigotes to evaluate the antileishma- Microscopy studies 433 392 nial effects of G2. This method was initially developed for 393 L. amazonensis; however, we successfully adapted it for L. Figure 7a depicts a promastigote of L. infantum that was 434 394 infantum by making the appropriate modifications. As shown incubated with an anti-β-tubulin antibody. The image shows 435 395 in Table 2, G2 showed antileishmanial effects on the intracel- the normal distribution pattern of this protein, which is 436 396 lular amastigotes of both species, with L. amazonensis being principally concentrated in the subpellicular region of the 437 397 the most sensitive. This was the same trend as that observed protozoa [56]. In contrast, marked morphological changes 438 398 for the promastigotes. Although the anti-amastigote activities were observed when the parasite was exposed to G2 (Fig. 7b), 439 399 were lower than those of the reference drug, the IC50 values with the circular shape indicating a benzimidazole-induced 440 400 were below an arbitrary threshold of 25 µM for both species redistribution of β-tubulin. This indicated an alteration of the 441 401 [55], demonstrating that this benzimidazole derivative had tubulin-microtubule equilibrium and suggested that tubulin 442 402 the potential to act as an antileishmanial compound. could be a target for G2. 443 403 To date, only four compounds containing a benzimidazole Benzimidazoles are well known to target the β-tubulin 444 404 moiety have been reported as active against L. amazonensis. subunit of some pathogens [57]. Although the β-tubulin 445 405 These gold-based complexes with benzimidazole moieties as structures in both helminths and protozoa have not been 446 406 the ligands [49] showed antileishmanial antiparasitic activ- resolved, significant efforts have been made to elucidate the 447 407 ity, with IC50 values of 5.18–42.19 µM for promastigotes and benzimidazole binding site using homology modeling stud- 448 408 5.77–25.95 µM for amastigotes. Interestingly, the benzimi- ies [58,59]. In these reports, binding sites have been proposed 449 409 dazole moieties per se did not show this activity.uncorrected However, and a series of benzimidazole proof carbamates has been docked 450 410 the IC50 values for G2 on L. amazonensis promastigotes and into the models. Based on these studies, it could be hypoth- 451 411 amastigotes were within the ranges reported by Mota et al. esized that the structural features of G2 could promote a 452 412 for the gold complexes. A comparison of the chemical struc- hydrogen bonding interaction with the Glu 198 residue at the 453 413 tures of the benzimidazole ligands employed (Supplementary β-tubulin binding site. More detailed docking and molecular 454 414 file 2, Fig. S6) and G2 indicated that the substitution of the dynamics studies will be required to develop a deeper insight 455 415 benzimidazole scaffold at positions 1 and 2 was important. into the interaction between G2 and β-tubulin. Furthermore, 456

123

Journal: 11030 MS: 9830 TYPESET DISK LE CP Disp.:2018/5/3 Pages: 12 Layout: Large Molecular Diversity

Fig. 7 Confocal microscopy of L. infantum promastigotes incubated with anti-β-tubulin without G2 treatment (a) and treated with G2 (b) Author Proof

Fig. 8 Macrophages infected with L. amazonensis (a and b)orL. infantum (c and d) were left untreated (a and c) or treated with G2 (b and d)

457 in silico studies with other targets will provideuncorrected a valuable future research should consider proof all of these as potential mech- 464 458 source of information related to alternative mechanisms of anisms of action. 465 459 action. For example, effects on Leishmania arginase have The effect of G2 on intracellular amastigotes was observed 466 460 been explored by Méndez-Cuesta et al. and Nieto-Meneses using light microscopy. For both species examined, the 467 461 et al. [60,61]. The bioactivities of benzimidazoles may also infected macrophages treated with G2 showed a marked 468 462 include disruption of metabolism, glucose uptake, and inhi- decrease in parasite load (Fig. 8). A vacuolated appearance 469 463 bition of mitochondrial dehydrogenase activity [62]. Thus, was observed in the G2-treated cells (Fig. 8b, d), and this 470

123

Journal: 11030 MS: 9830 TYPESET DISK LE CP Disp.:2018/5/3 Pages: 12 Layout: Large Molecular Diversity

471 was particularly apparent in those infected with L. amazo- vector and reservoir species. PLoS Negl Trop Dis 4:e585. https:// 520 521 472 nensis. Weakly basic compounds were previously reported to doi.org/10.1371/journal.pntd.0000585 4. Hotez PJ, Alvarado M, Basáñez M-G, Bolliger I, Bourne R, Boussi- 522 473 cause cytoplasmic vacuolation in macrophages [63]. There- nesq M, Brooker SJ, Brown AS, Buckle G, Budke CM, Carabin 523 474 fore, these observations indicate that this benzimidazole H, Coffeng LE, Fèvre EM, Fürst T, Halasa YA, Jasrasaria R, 524 475 was internalized by the host cell, an essential feature of an Johns NE, Keiser J, King CH, Lozano R, Murdoch ME, O’Hanlon 525 526 476 antileishmanial compound. S, Pion SDS, Pullan RL, Ramaiah KD, Roberts T, Shepard DS, Smith JL, Stolk WA, Undurraga EA, Utzinger J, Wang M, Murray 527 CJL, Naghavi M (2014) The global burden of disease study 2010: 528 interpretation and implications for the neglected tropical diseases. 529 PLoS Negl Trop Dis 8:e2865. https://doi.org/10.1371/journal.pntd. 530 477 Conclusions 0002865 531 5. Who (2016) World Health Organization. In: Leishmaniasis. http:// 532 478 This study was performed to investigate benzimidazole scaf- www.who.int/leishmaniasis/en/ 533 6. Gillespie PM, Beaumier CM, Strych U, Hayward T, Hotez PJ, 534 479 folds as potential antileishmanial agents. We searched for Bottazzi MA (2016) Status of vaccine research and development 535 480 target scaffolds in the ChEMBL database, combined with of vaccines for leishmaniasis. Vaccine 34:2992–2995. https://doi. 536 481 additional literature searches. Benzimidazole derivatives org/10.1016/j.vaccine.2015.12.071 537 482 were found to be active against 6 Leishmania species, with a 7. Lamotte S, Späth GF, Rachidi N, Prina E (2017) The enemy within: 538 targeting host-parasite interaction for antileishmanial drug discov- 539 483 frequency ranking of L. major > L. donovani > L. infan- ery. PLoS Negl Trop Dis 11:e0005480 540 484 = tum> L. mexicana > L. amazonensis L. braziliensis. 8. Tiuman TS, Santos AO, Ueda-Nakamura T, Dias Filho BP, Naka- 541 485 The biological activities of benzimidazole derivatives var- mura CV (2011) Recent advances in leishmaniasis treatment. Int 542 Author Proof 486 ied greatly and may depend on the substitution pattern of the J Infect Dis 15:e525–e532. https://doi.org/10.1016/j.ijid.2011.03. 543 021 544 487 scaffold, with the 1, 2, 5, and 6 positions identified as relevant 9. Séguin O, Descoteaux A (2016) Leishmania, the phagosome, and 545 488 for future structure–activity relationship studies. In addition, host responses: the journey of a parasite. Cell Immunol 309:1–6. 546 489 the approach used could be applied to other chemoinformatic https://doi.org/10.1016/j.cellimm.2016.08.004 547 490 studies of different structural features. 10. Nagle AS, Khare S, Kumar AB, Supek F, Buchynskyy A, Mathi- 548 son CJ, Chennamaneni NK, Pendem N, Buckner FS, Gelb MH, 549 491 The benzimidazole derivative G2 demonstrated antileish- Molteni V (2014) Recent developments in drug discovery for 550 492 manial activity against both L. amazonensis and L. infantum. leishmaniasis and human African trypanosomiasis. Chem Rev 551 493 This finding indicates that deeper investigation is warranted 114:11305–11347. https://doi.org/10.1021/cr500365f 552 494 into the potential treatment of cutaneous leishmaniasis using 11. Sangshetti JN, Kalam Khan FA, Arote R Kulkarni AA, Patil RH 553 (2015) Antileishmanial drug discovery: comprehensive review of 554 495 benzimidazoles. Furthermore, our results provide a rationale the last 10 years. RSC Adv 5:32376–32415. https://doi.org/10. 555 496 for elucidation of the interaction between benzimidazoles 1039/C5RA02669E 556 497 and tubulin, as well as other possible biological targets. These 12. Cumming JG, Davis AM, Muresan S, Haeberlein M, Chen H (2013) 557 498 studies can be initiated using computational techniques. Chemical predictive modelling to improve compound quality. Nat 558 Rev Drug Discov 12:948–962. https://doi.org/10.1038/nrd4128 559 13. Medina-Franco JL (2012) Interrogating novel areas of chemical 560 499 Acknowledgements YRA thanks the Consejo Nacional de Ciencia space for drug discovery using chemoinformatics. Drug Dev Res 561 500 y Tecnología for financial support: Ph.D. scholarship 211321, Ph.D. 73:430–438. https://doi.org/10.1002/ddr.21034 562 501 mixed scholarship Grant 290618, and Programa de Apoyo a la Inves- 14. Muegge I, Bergner A, Kriegl JM (2016) Computer-aided drug 563 502 tigación y el Posgrado PAIP 5000-9157, Facultad de Química, Uni- design at Boehringer Ingelheim. J Comput Aided Mol Des 31:1–11. 564 503 versidad Nacional Autónoma de México (UNAM). YRA also thanks https://doi.org/10.1007/s10822-016-9975-3 565 504 J. Fernando Márquez-Domínguez for his mentorship and invaluable 15. Krasky A, Rohwer A, Schroeder J, Selzer PM (2007) A combined 566 505 guidance in the magic paths of science. JLMF thanks Programa de bioinformatics and chemoinformatics approach for the develop- 567 506 Apoyo a la Investigación y el Posgrado (PAIP) Grant 5000-9163, Fac- ment of new antiparasitic drugs. Genomics 89:36–43. https://doi. 568 507 ultad de Química, UNAM. The authors are also grateful for the Spanish org/10.1016/j.ygeno.2006.09.008 569 508 Agency of International Cooperation for Development (AECID) Grant 16. Saldívar-González FI, Jesús Naveja J, Palomino-Hernández O, 570 509 AP/0397670/11 and the pre-doctoral fellowship awarded to PBR. Medina-Franco JL (2017) Getting SMARt in drug discovery: 571 chemoinformatics approaches for mining structure-multiple activ- 572 ity relationships. RSC Adv 7:632–641. https://doi.org/10.1039/ 573 C6RA26230A 574 510 References 17. Sharma R, Lawrenson AS, Fisher NE, Warman A, Shone AE, Hill 575 A, Mbekeani A, Pidathala C, Amewu RK, Leung S, Gibbons P, 576 511 1. Steverding D (2017) The history of leishmaniasis. Parasit Vectors Hong DW, Stocks P, Nixon GL, Chadwick J, Shearer J, Gow- 577 512 10:82–92. https://doi.org/10.1186/s13071-017-2028-5uncorrecteders I, Cronk D, Parel proof SP, O’Neill PM, Ward SA, Biagini GA, 578 513 2. Zulfiqar B, Shelper TB, Avery VM (2017) Leishmaniasis drug Berry NG (2012) Identification of novel antimalarial chemotypes 579 514 discovery: recent progress and challenges in assay develop- via chemoinformatic compound selection methods for a high- 580 515 ment. Drug Discov Today 22:1516–1531. https://doi.org/10.1016/ throughput screening program against the novel malarial target, 581 516 j.drudis.2017.06.004 PfNDH2: increasing hit rate via virtual screening methods. J Med 582 517 3. González C, Wang O, Strutz SE, González-Salazar C, Sánchez- Chem 55:3144–3154. https://doi.org/10.1021/jm3001482 583 518 Cordero V, Sarkar S (2010) Climate change and risk of leishmani- 18. Bolt HL, Eggimann GA, Denny PW, Cobb SL (2016) Enlarging the 584 519 asis in North America: predictions from ecological niche models of chemical space of anti-leishmanials: a structure-activity relation- 585

123

Journal: 11030 MS: 9830 TYPESET DISK LE CP Disp.:2018/5/3 Pages: 12 Layout: Large Molecular Diversity

586 ship study of peptoids against Leishmania mexicana, a causative Mol Biochem Parasitol 98:53–65. https://doi.org/10.1016/S0166- 652 587 agent of cutaneous leishmaniasis. Med Chem Commun 7:799–805. 6851(98)00146-7 653 588 https://doi.org/10.1039/C6MD00060F 34. Hernández-Luis F, Hernández-Campos A, Castillo R, Navarrete- 654 589 19. Prates Lorenzo V, Carneiro Lúcio ASS, Scotti L, Tavares JF, Bar- Vázquez G, Soria-Arteche O, Hernández-Hernández M, Yépez- 655 590 bosa Filho JM, de Souza Lima TK, da Câmara Rocha J, Scotti MT Mulia L (2010) Synthesis and biological activity of 2- 656 591 (2016) Structure- and ligand-based approaches to evaluate apor- (trifluoromethyl)-1H-benzimidazole derivatives against some pro- 657 592 phynic alkaloids from annonaceae as multi-target agent against tozoa and Trichinella spiralis. Eur J Med Chem 45:3135–3141. 658 593 leishmania donovani. Curr Pharm Des 22:5196–5203. https://doi. https://doi.org/10.1016/j.ejmech.2010.03.050 659 594 org/10.2174/1381612822666160513144853 35. Mayence A, Pietka A, Collins MS, Cushion MT, Tekwani BL, 660 595 20. Leite FHA, Froes TQ, da Silva SG, Macêdo de Souza EI, Gomes Huang TL, Vanden Eynde JJ (2008) Novel bisbenzimidazoles with 661 596 Vital-Fujii DG, Goulart Trossini GH, da Rocha Silva, Pita S, Santos antileishmanial effectiveness. Bioorg Med Chem Lett 18:2658– 662 597 Castilho M (2017) An integrated approach towards the discovery 2661. https://doi.org/10.1016/j.bmcl.2008.03.020 663 598 of novel non-nucleoside Leishmania major pteridine reductase 1 36. Escudero-Martínez JM, Pérez-Pertejo Y,Reguera RM, Castro MA, 664 599 inhibitors. Eur J Med Chem 132:322–332. https://doi.org/10.1016/ Rojo MV, Santiago C, Abad A, García PA, López-Pérez JL, San 665 600 j.ejmech.2017.03.043 Feliciano A, Balaña-Fouce R (2017) Antileishmanial activity and 666 601 21. Bento AP, Gaulton A, Hersey A, Bellis LJ, Chambers J, Davies tubulin polymerization inhibition of podophyllotoxin derivatives 667 602 M, Krüger FA, Light Y, Mak L, McGlinchey S, Nowotka M, on Leishmania infantum. Int J Parasitol Drugs Drug Resist 7:272– 668 603 Papadatos G, Santos R, Overington JP (2013) The ChEMBL bioac- 285. https://doi.org/10.1016/j.ijpddr.2017.06.003 669 604 tivity database: an update. Nucleic Acids Res 42:D1083–D1090. 37. Tonelli M, Gabriele E, Piazza F, Basilico N, Parapini S, Tasso B, 670 605 https://doi.org/10.1093/nar/gkt1031 Loddo R, Sparatore F, Sparatore A (2018) Benzimidazole deriva- 671 606 22. Heikamp K, Bajorath J (2011) Large-scale similarity search pro- tives endowed with potent antileishmanial activity. J Enzyme Inhib 672 607 filing of ChEMBL compound data sets. J Chem Inf Model Med Chem 33:210–226. https://doi.org/10.1080/14756366.2017. 673 608 51:1831–1839. https://doi.org/10.1021/ci200199u 1410480 674 Author Proof 609 23. Gaulton A, Hersey A, Nowotka M, Bento AP, Chambers J, Mendez 38. Bemis GW, Murcko MA (1996) The properties of known drugs. 675 610 D, Mutowo P, Atkinson F, Bellis LJ, Cibrián-Uhalte E, Davies M, 1. Molecular frameworks. J Med Chem 39:2887–2893. https://doi. 676 611 Dedman N, Karlsson A, Magariños MP, Overington JP, Papadatos org/10.1021/jm9602928 677 612 G, Smit I, Leach AR (2017) The ChEMBL database in 2017. 39. Medina-Franco JL, Petit J, Maggiora GM (2006) Hierarchical 678 613 Nucleic Acids Res 45:D945–D954. https://doi.org/10.1093/nar/ strategy for identifying active chemotype classes in compound 679 614 gkw1074 databases. Chem Biol Drug Des 67:395–408. https://doi.org/10. 680 615 24. Barot KP, Nikolova S, Ivanov I, Ghate MD (2013) Novel 1111/j.1747-0285.2006.00397.x 681 616 research strategies of benzimidazole derivatives: a review. 40. Xu Y-J, Johnson M (2002) Using molecular equivalence numbers 682 617 Mini-Rev Med Chem 13:1421–1447. https://doi.org/10.2174/ to visually explore structural features that distinguish chemical 683 618 13895575113139990072 libraries. J Chem Inf Comput Sci 42:912–926. https://doi.org/10. 684 619 25. Croft SL (1997) The current status of antiparasite chemotherapy. 1021/ci025535l 685 620 Parasitology 114(Suppl):S3–S15 41. Bilbao-Ramos P, Galiana-Roselló C, Dea-Ayuela MA, González- 686 621 26. Lacey E (1990) Mode of action of benzimidazoles. Parasitol Today Alvarez M, Vega C, Rolón M, Pérez-Serrano J, Bolás-Fernández F, 687 622 6:112–115. https://doi.org/10.1016/0169-4758(90)90227-U González-Rosende ME (2012) Nuclease activity and ultrastructural 688 623 27. Andrzejewska M, Yépez-Mulia L, Cedillo-Rivera R, Tapia A, effects of new sulfonamides with anti-leishmanial and trypanoci- 689 624 Vilpo L, Vilpo J, Kazimierczuk Z (2002) Synthesis, antiproto- dal activities. Parasitol Int 61:604–613. https://doi.org/10.1016/j. 690 625 zoal and anticancer activity of substituted 2-trifluoromethyl- and parint.2012.05.015 691 626 2-pentafluoroethylbenzimidazoles. Eur J Med Chem 37:973–978. 42. Bilbao-Ramos P, Sifontes-Rodríguez S, Dea-Ayuela MA, Bolás- 692 627 https://doi.org/10.1016/S0223-5234(02)01421-6 Fernández F (2012) A fluorometric method for evaluation of 693 628 28. Katiyar SK, Gordon VR, McLaughlin GL, Edlind TD (1994) pharmacological activity against intracellular Leishmania amastig- 694 629 Antiprotozoal activities of benzimidazoles and correlations with otes. J Microbiol Methods 89:8–11. https://doi.org/10.1016/j. 695 630 beta-tubulin sequence. Antimicrob Agents Chemother 38:2086– mimet.2012.01.013 696 631 2090. https://doi.org/10.1128/AAC.38.9.2086 43. Körner U, Fuss V, Steigerwald J, Moll H (2006) Biogene- 697 632 29. Reynoldson JA, Thompson RC, Horton RJ (1992) Albendazole as sis of Leishmania major-harboring vacuoles in murine dendritic 698 633 a future antigiardial agent. Parasitol Today 8:412–414. https://doi. cells. Infect Immun 74:1305–1312. https://doi.org/10.1128/IAI. 699 634 org/10.1016/0169-4758(92)90193-6 74.2.1305-1312.2006 700 635 30. Valdez J, Cedillo R, Hernández-Campos A, Yépez L, Hernández- 44. Yongye AB, Waddell J, Medina-Franco JL (2012) Molecular scaf- 701 636 Luis F, Navarrete-Vázquez G, Tapia A, Cortés R, Hernández fold analysis of natural products databases in the public domain. 702 637 M, Castillo R (2002) Synthesis and antiparasitic activity of 1H- Chem Biol Drug Des 80:717–724. https://doi.org/10.1111/cbdd. 703 638 benzimidazole derivatives. Bioorg Med Chem Lett 12:2221–2224. 12011 704 639 https://doi.org/10.1016/S0960-894X(02)00346-3 45. Kraft R, Kahn A, Medina-Franco JL, Orlowski ML, Baynes C, 705 640 31. Armson A, Kamau SW, Grimm F, Reynoldson JA, Best WM, López-Vallejo F, Barnard K, Maggiora GM, Restifo LL (2012) 706 641 MacDonald LM, Thomspon RCA (1999) A comparison of the A cell-based fascin bioassay identifies compounds with potential 707 642 effects of a benzimidazole and the dinitroanilines against Leish- anti-metastasis or cognition-enhancing functions. Dis Model Mech 708 643 mania infantum. Acta Trop 73:303–311. https://doi.org/10.1016/ 6:217–235. https://doi.org/10.1242/dmm.008243 709 644 S0001-706X(99)00034-0 uncorrected46. López-Vallejo F, Nefzi proof A, Bender A, Owen JR, Nabney IT, 710 645 32. Jayanarayan KG, Dey CS (2004) Altered expression, polymerisa- Houghten RA, Medina-Franco JL (2011) Increased diversity 711 646 tion and cellular distribution of alpha-/beta-tubulins and apoptosis- of libraries from libraries: chemoinformatic analysis of bis- 712 647 like cell death in arsenite resistant Leishmania donovani promastig- diazacyclic libraries. Chem Biol Drug Des 77:328–342. https:// 713 648 otes. Int J Parasitol 34:915–925. https://doi.org/10.1016/j.ijpara. doi.org/10.1111/j.1747-0285.2011.01100.x 714 649 2004.03.009 47. Howarth J, Hanlon K (2003) N-ferrocenylmethyl, N′-Methyl- 715 650 33. Werbovetz KA, Brendle JJ, Sackett DL (1999) Purification, char- 2-substituted benzimidazolium iodide salts with In vitro activ- 716 651 acterization, and drug susceptibility of tubulin from Leishmania. ity against the Leishmania infantum parasite strain L1. Bioorg 717

123

Journal: 11030 MS: 9830 TYPESET DISK LE CP Disp.:2018/5/3 Pages: 12 Layout: Large Molecular Diversity

718 Med Chem Lett 13:2017–2020. https://doi.org/10.1016/S0960- 56. Chavan HD, Singh G, Dey CS (2007) Confocal microscopic 763 719 894X(03)00327-5 investigation of tubulin distribution and effect of paclitaxel on 764 720 48. Papadatos G, Gaulton A, Hersey A, Overington JP (2015) Activity, posttranslationally modified tubulins in sodium arsenite resistant 765 721 assay and target data curation and quality in the ChEMBL database. Leishmania donovani. Exp Parasitol 116:320–326. https://doi.org/ 766 722 J Comput Aided Mol Des 29:885–896. https://doi.org/10.1007/ 10.1016/j.exppara.2007.01.016 767 723 s10822-015-9860-5 57. Sharma OP, Pan A, Hoti SL, Jadhav A, Kannan M, Mathur PP 768 724 49. Mota VZ, De Carvalho GSG, Da Silva AD, Sodré Costa LA, (2012) Modeling, docking, simulation, and inhibitory activity of 769 725 de Almeida Machado P, Soares Coimbra E, Veríssima Ferreira the benzimidazole analogue against β-tubulin protein from Brugia 770 726 C, Mika Shishido S, Cuin A (2014) Gold complexes with benz- malayi for treating lymphatic filariasis. Med Chem Res 21:2415– 771 727 imidazole derivatives: synthesis, characterization and biological 2427. https://doi.org/10.1007/s00044-011-9763-5 772 728 studies. Biometals 27:183–194. https://doi.org/10.1007/s10534- 58. Aguayo-Ortiz R, Méndez-Lucio O, Romo-Mancillas A, Castillo R, 773 729 014-9703-1 Yépez-Mulia L, Medina-Franco JL, Hernández-Campos A (2013) 774 730 50. Oh S, Kim S, Kong S, Yang G, Lee N, Han D, Goo J, Siqueira- Molecular basis for benzimidazole resistance from a novel β- 775 731 Neto JL, Freitas-Junior LH, Song R (2014) Synthesis and biological tubulin binding site model. J Mol Graph Model 45:26–37. https:// 776 732 evaluation of 2,3-dihydroimidazo[1,2-a]benzimidazole derivatives doi.org/10.1016/j.jmgm.2013.07.008 777 733 against Leishmania donovani and Trypanosoma cruzi. Eur J Med 59. Aguayo-Ortiz R, Cano-González L, Castillo R, Hernández- 778 734 Chem 84:395–403. https://doi.org/10.1016/j.ejmech.2014.07.038 Campos A, Domínguez L (2017) Structure-based approaches for 779 735 51. Shaukat A, Mirza HM, Ansari AH, Yasinzai M, Zaidi SZ, Dilshad the design of benzimidazole-2-carbamate derivatives as tubulin 780 736 S, Ansari FL (2012) Benzimidazole derivatives: synthesis, leish- polymerization inhibitors. Chem Biol Drug Des 90:40–51. https:// 781 737 manicidal effectiveness, and molecular docking studies. Med Chem doi.org/10.1111/cbdd.12926 782 738 Res 22:3606–3620. https://doi.org/10.1007/s00044-012-0375-5 60. Méndez-Cuesta CA, Méndez-Lucio O, Castillo R (2012) Homol- 783 739 52. De Rycker M, Hallyburton I, Thomas J, Campbell L, Wyllie S, Joshi ogy modeling, docking and molecular dynamics of the Leishmania 784 740 D, Cameron S, Gilbert IH, Wyatt PG, Frearson JA, Fairlamb AH, mexicana arginase: a description of the catalytic site useful for drug 785 Author Proof 741 Gray DW (2013) Comparison of a high-throughput high-content design. J Mol Graph Model 38:50–59. https://doi.org/10.1016/j. 786 742 intracellular Leishmania donovani assay with an axenic amastigote jmgm.2012.08.003 787 743 assay. Antimicrob Agents Chemother 57:2913–2922. https://doi. 61. Nieto-Meneses R, Castillo R, Hernández-Campos A, Maldonado- 788 744 org/10.1128/AAC.02398-12 Rangel A, Matius-Ruiz JB, Trejo-Soto PJ, Nogueda-Torres B, Dea- 789 745 53. Vermeersch M, da Luz RI, Toté K, Timmermans J-P, Cos P, Ayuela MA, Bolás-Fernandez F, Méndez-Cuesta C, Yépez-Mulia 790 746 Maes L (2009) In vitro susceptibilities of Leishmania donovani L (2017) In vitro activity of new N-benzyl-1H-benzimidazol-2- 791 747 promastigote and amastigote stages to antileishmanial reference amine derivatives against cutaneous, mucocutaneous and visceral 792 748 drugs: practical relevance of stage-specific differences. Antimicrob Leishmania species. Exp Parasitol 184:82–89. https://doi.org/10. 793 749 Agents Chemother 53:3855–3859. https://doi.org/10.1128/AAC. 1016/j.exppara.2017.11.009 794 750 00548-09 62. Boiani M, Boiani L, Merlino A, Hernández P, Chidichimo A, Caz- 795 751 54. De Muylder G, Ang KKH, Chen S, Arkin MR, Engel J, McKerrow zulo JJ, Cerecetto H, González M (2009) Second generation of 796 752 JH (2011) A Screen against Leishmania intracellular amastigotes: 2H-benzimidazole 1,3-dioxide derivatives as anti-trypanosomatid 797 753 comparison to a promastigote screen and identification of a host agents: synthesis, biological evaluation, and mode of action studies. 798 754 cell-specific hit. PLoS Negl Trop Dis 5:e1253. https://doi.org/10. Eur J Med Chem 44:4426–4433. https://doi.org/10.1016/j.ejmech. 799 755 1371/journal.pntd.0001253 2009.06.014 800 756 55. Andrade-Neto VV, Cunha-Júnior EF, do Canto-Cavalheiro MM, 63. Ohkuma S, Poole B (1981) Cytoplasmic vacuolation of mouse peri- 801 757 Correa Atella G, de Almeida Fernandes T, Ribeiro Costa PR, toneal macrophages and the uptake into lysosomes of weakly basic 802 758 Torres-Santos EC (2016) Antileishmanial activity of ezetimibe: substances. J Cell Biol 90:656–664. https://doi.org/10.1083/jcb. 803 759 inhibition of sterol biosynthesis, in vitro synergy with azoles, 90.3.656 804 760 and efficacy in experimental cutaneous Leishmaniasis. Antimicrob 761 Agents Chemother 60:6844–6852. https://doi.org/10.1128/AAC. 762 01545-16

uncorrected proof

123

Journal: 11030 MS: 9830 TYPESET DISK LE CP Disp.:2018/5/3 Pages: 12 Layout: Large