Novel nitro(triazole/imidazole)-based heteroarylamides/sulfonamides as potential antitrypanosomal agents

Design and Synthesis of 2-Nitroimidazole-1,2,3-triazole Sulfonamide Hybrids as Potent and Selective Anti-Trypanosomatid Agents

A series of 2-nitroimidazole-1,2,3-triazole sulfonamide hybrid analogs were designed using medicinal chemistry approaches, such as bioisosterism, molecular hybridization, Topliss tree decision, and Craig plot. A total of 24 compounds were synthesized via click chemistry in satisfactory yields. Overall, analogs 15 a-x exhibited relevant in vitro anti-trypanosomatid activity against amastigote forms of T. cruzi and without cytotoxic effect on LLC-MK2 cells. Analogs 15 b (R1=4-Cl-Ph; IC50=1.63 μM, SI=>30.65), 15 m (R1=3,4-di-Cl-Ph; IC50=0.63 μM, SI=>78.96), and 15 s (R1=Ph-4-O-Ph; IC50=0.63 μM, SI=>79.90) demonstrated pronounced antitrypanosomal activity, more active than the reference drug, benznidazole and with good selectivity indexes. Furthermore, analog 15 b (R1=4-Cl-Ph; IC50=0.5 μM, SI=>100) exhibited an outstanding antileishmanial activity against amastigote forms of Leishmania (L.) amazonensis and impressive selectivity index, comparable to the reference compound amphotericin B. The mutagenicity of compounds 15 b and 15 m were evaluated against Salmonella typhimurium strains (TA98, TA100 and TA102). Compound 15 b exhibited mutageniticy only at a concentration of 500  μg/plate for the TA100 strain, whereas compound 15 m was considered non-mutagenic. These findings suggest that 2-nitroimidazoles-1,2,3-triazole sulfonamide hybrid analogs are promising anti-trypanosomatid candidates for future in vivo studies.

Drugs in preclinical and early clinical development for the treatment of Chagas´s disease: the current status

INTRODUCTION

Chagas disease is spreading faster than expected in different countries, and little progress has been reported in the discovery of new drugs to combat Trypanosoma cruzi infection in humans. Recent clinical trials have ended with small hope. The pathophysiology of this neglected disease and the genetic diversity of parasites are exceptionally complex. The only two drugs available to treat patients are far from being safe, and their efficacy in the chronic phase is still unsatisfactory.

AREAS COVERED

This review offers a comprehensive examination and critical review of data reported in the last 10 years, and it is focused on findings of clinical trials and data acquired in vivo in preclinical studies.

EXPERT OPINION

The in vivo investigations classically in mice and dog models are also challenging and time-consuming to attest cure for infection. Poorly standardized protocols, availability of diagnosis methods and disease progression markers, the use of different T. cruzi strains with variable benznidazole sensitivities, and animals in different acute and chronic phases of infection contribute to it. More synchronized efforts between research groups in this field are required to put in evidence new promising substances, drug combinations, repurposing strategies, and new pharmaceutical formulations to impact the therapy.

Design and Synthesis of Novel 3-Nitro-1H-1,2,4-triazole-1,2,3-triazole-1,4-disubstituted Analogs as Promising Antitrypanosomatid Agents: Evaluation of In Vitro Activity against Chagas Disease and Leishmaniasis

A series of 28 compounds, 3-nitro-1H-1,2,4-triazole, were synthesized by click-chemistry with diverse substitution patterns using medicinal chemistry approaches, such as bioisosterism, Craig-plot, and the Topliss set with excellent yields. Overall, the analogs demonstrated relevant in vitro antitrypanosomatid activity. Analog 15g (R1 = 4-OCF3-Ph, IC50 = 0.09 μM, SI = >555.5) exhibited an outstanding antichagasic activity (Trypanosoma cruzi, Tulahuen LacZ strain) 68-fold more active than benznidazole (BZN, IC50 = 6.15 μM, SI = >8.13) with relevant selectivity index, and suitable LipE = 5.31. 15g was considered an appropriate substrate for the type I nitro reductases (TcNTR I), contributing to a likely potential mechanism of action for antichagasic activity. Finally, 15g showed nonmutagenic potential against Salmonella typhimurium strains (TA98, TA100, and TA102). Therefore, 3-nitro-1H-1,2,4-triazole 15g is a promising antitrypanosomatid candidate for in vivo studies.

Recent advancement in drug development of nitro(NO2 )-heterocyclic compounds as lead scaffolds for the treatment of Mycobacterium tuberculosis

Tuberculosis (TB) is an infectious disease caused predominantly by Mycobacterium tuberculosis (Mtb). It was responsible for approximately 1.4 million deaths worldwide in 2019. The lack of new drugs to treat drug-resistant strains is a principal factor for the slow rise in TB infections. Our aim is to aid the development of new TB treatments by describing improvements (last decade, 2011-2021) to nitro(NO₂ )-based compounds that have shown activity or pharmacological properties (e.g., anti-proliferative, anti-kinetoplastid) against Mtb. For all compounds, we have included final correlations of minimum inhibitory concentrations against Mtb (H₃₇ Rv).

Planning new Trypanosoma cruzi CYP51 inhibitors using QSAR studies

Chagas disease kills over 10,000 people per year, and approximately 8 million people are infected by Trypanosoma cruzi. The reference drug for treatment of the disease, benznidazole, is the same since the 70s. In recent years, many CYP51 inhibitors were tested against this parasite's target. One of them, posaconazole, was even tested in clinical trials that unfortunately were not successful. Nevertheless, there are still many evidences that CYP51 is a great potential target to treat T. cruzi infection. The research for new effective molecules that can cure the chronic phase of the disease is essential. 2D and 3D-quantitative structure activity relationship (QSAR) studies were conducted in this work to create three QSAR models using the chemical structures of 197 published compounds that already went through either in vivo or in vitro tests. After the analysis of the models, new analogues not yet synthesized were suggested here and had their biological activity and synthetic availability assessed.

Single- and Two-Electron Reduction of Nitroaromatic Compounds by Flavoenzymes: Mechanisms and Implications for Cytotoxicity

Nitroaromatic compounds (ArNO₂) maintain their importance in relation to industrial processes, environmental pollution, and pharmaceutical application. The manifestation of toxicity/therapeutic action of nitroaromatics may involve their single- or two-electron reduction performed by various flavoenzymes and/or their physiological redox partners, metalloproteins. The pivotal and still incompletely resolved questions in this area are the identification and characterization of the specific enzymes that are involved in the bioreduction of ArNO₂ and the establishment of their contribution to cytotoxic/therapeutic action of nitroaromatics. This review addresses the following topics: (i) the intrinsic redox properties of ArNO₂, in particular, the energetics of their single- and two-electron reduction in aqueous medium; (ii) the mechanisms and structure-activity relationships of reduction in ArNO₂ by flavoenzymes of different groups, dehydrogenases-electrontransferases (NADPH:cytochrome P-450 reductase, ferredoxin:NADP(H) oxidoreductase and their analogs), mammalian NAD(P)H:quinone oxidoreductase, bacterial nitroreductases, and disulfide reductases of different origin (glutathione, trypanothione, and thioredoxin reductases, lipoamide dehydrogenase), and (iii) the relationships between the enzymatic reactivity of compounds and their activity in mammalian cells, bacteria, and parasites.

Review on Experimental Treatment Strategies Against Trypanosoma cruzi

Chagas disease is a neglected tropical disease caused by the protozoan Trypanosoma cruzi. Currently, only nitroheterocyclic nifurtimox (NFX) and benznidazole (BNZ) are available for the treatment of Chagas disease, with limitations such as variable efficacy, long treatment regimens and toxicity. Different strategies have been used to discover new active molecules for the treatment of Chagas disease. Target-based and phenotypic screening led to thousands of compounds with anti-T. cruzi activity, notably the nitroheterocyclic compounds, fexinidazole and its metabolites. In addition, drug repurposing, drug combinations, re-dosing regimens and the development of new formulations have been evaluated. The CYP51 antifungal azoles, as posaconazole, ravuconazole and its prodrug fosravuconazole presented promising results in experimental Chagas disease. Drug combinations of nitroheterocyclic and azoles were able to induce cure in murine infection. New treatment schemes using BNZ showed efficacy in the experimental chronic stage, including against dormant forms of T. cruzi. And finally, sesquiterpene lactone formulated in nanocarriers displayed outstanding efficacy against different strains of T. cruzi, susceptible or resistant to BNZ, the reference drug. These pre-clinical results are encouraging and provide interesting evidence to improve the treatment of patients with Chagas disease.

An insight on medicinal attributes of 1,2,4-triazoles

The present review aims to summarize the pharmacological profile of 1,2,4-triazole, one of the emerging privileged scaffold, as antifungal, antibacterial, anticancer, anticonvulsant, antituberculosis, antiviral, antiparasitic, analgesic and anti-inflammatory agents, etc. along with structure-activity relationship. The comprehensive compilation of work carried out in the last decade on 1,2,4-triazole nucleus will provide inevitable scope for researchers for the advancement of novel potential drug candidates having better efficacy and selectivity.

Antileishmanial activity of 4-phenyl-1-[2-(phthalimido-2-yl)ethyl]-1H-1,2,3-triazole (PT4) derivative on Leishmania amazonensis and Leishmania braziliensis: In silico ADMET, in vitro activity, docking and molecular dynamic simulations

Organic compounds obtained by click chemistry reactions have demonstrated a broad spectrum of biological activities being widely applied for the development of molecules against pathogens of medical and veterinary importance. Cutaneous leishmaniasis (CL), caused by intracellular protozoa parasite of genus Leishmania, comprises a complex of clinical manifestations that affect the skin and mucous membranes. The available drugs for the treatment are toxic and costly, with long periods of treatment, and the emergence of resistant strains has been reported. In this study we investigated the in vitro effects of a phthalimide-1,2,3-triazole derivative, the 4-Phenyl-1-[2-(phthalimido-2-yl)ethyl]-1H-1,2,3-triazole (PT4) obtained by click chemistry, on mammalian cells and on L. amazonensis and L. braziliensis, the causative agents of CL in Brazil. In silico ADMET evaluation of PT4 showed that this molecule has good pharmacokinetic properties with no violation of Lipinski's rules. The in vitro assays showed that PT4 was more selective for both Leishmania species than to mammalian cells. This compound also presented low cytotoxicity to mammalian cells with CC₅₀ > 500 μM. Treatment of promastigote forms with different concentrations of PT4 resulted in ultrastructural alterations, such as plasma membrane wrinkling, shortening of cell body, increased cell volume and cell rupture. The molecular dynamic simulations showed that PT4 interacts with Lanosterol 14 α-demethylase from Leishmania, an essential enzyme of lipid synthesis pathway in this parasite. Our results demonstrated PT4 was effective against both species of Leishmania. PT4 caused a decrease of mitochondrial membrane potential and increased production of reactive oxygen species, which may lead to parasite death. Taken together, our results pointed PT4 as promissing therapeutic agent against CL.

Synthesis and Antitrypanosomal Activity of 1,4-Disubstituted Triazole Compounds Based on a 2-Nitroimidazole Scaffold: a Structure-Activity Relationship Study

Chagas disease affects 6-8 million people worldwide, remaining a public health concern. Toxicity, several adverse effects and inefficiency in the chronic stage of the disease are the major challenges regarding the available treatment protocols. This work involved the synthesis of twenty-two 1,4-disubstituted-1,2,3-triazole analogues of benznidazole (BZN), by using a click chemistry strategy. Analogues were obtained in moderate to good yields (40-97 %). Antitrypanosomal activity was evaluated against the amastigote forms of Trypanosoma cruzi. Compound 8 a (4-(2-nitro-1H-imidazol-1-yl)methyl)-1-phenyl-1H-1,2,3-triazole) without substituents on phenyl ring showed similar biological activity to BZN (IC₅₀ =3.0 μM, SI>65.3), with an IC₅₀ =3.1 μM and SI>64.5. Compound 8 o (3,4-di-OCH₃ -Ph) with IC₅₀ = 0.65 μM was five-fold more active than BZN, and showed an excellent selectivity index (SI>307.7). Compound 8 v (3-NO₂ , 4-CH₃ -Ph) with IC₅₀ =1.2 μM and relevant SI>166.7, also exhibited higher activity than BZN. SAR analysis exhibited a pattern regarding antitrypanosomal activity relative to BZN, in compounds with electron-withdrawing groups (Hammett σ+) at position 3, and electron-donating groups (Hammett σ-) at position 4, as observed in 8 o and 8 v. Further research might explore in vivo antitrypanosomal activity of promising analogues 8 a, 8 o, and 8 v. Overall, this study indicates that approaches such as the bioisosteric replacement of amide group by 1,2,3-triazole ring, the use of click chemistry as a synthesis strategy, and design tools like Craig-plot and Topliss tree are promising alternatives to drug discovery.

Recent Advances in the Discovery of Novel Antiprotozoal Agents

Parasitic diseases have serious health, social, and economic impacts, especially in the tropical regions of the world. Diseases caused by protozoan parasites are responsible for considerable mortality and morbidity, affecting more than 500 million people worldwide. Globally, the burden of protozoan diseases is increasing and is been exacerbated because of a lack of effective medication due to the drug resistance and toxicity of current antiprotozoal agents. These limitations have prompted many researchers to search for new drugs against protozoan parasites. In this review, we have compiled the latest information (2012-2017) on the structures and pharmacological activities of newly developed organic compounds against five major protozoan diseases, giardiasis, leishmaniasis, malaria, trichomoniasis, and trypanosomiasis, with the aim of showing recent advances in the discovery of new antiprotozoal drugs.

Benzo[b]thiophene-thiazoles as potent anti-Toxoplasma gondii agents: Design, synthesis, tyrosinase/tyrosine hydroxylase inhibitors, molecular docking study, and antioxidant activity

Synthesis and investigation of anti-Toxoplasma gondii activity of novel thiazoles containing benzo [b]thiophene moiety are presented. Among the derivatives, compound 3k with adamantyl group shows exceptionally high potency against Me49 strain with IC₅₀ (8.74 μM) value which is significantly lower than the activity of trimethoprim (IC₅₀ 39.23 μM). In addition, compounds 3a, 3b and 3k showed significant activity against RH strain (IC₅₀ 51.88-83.49 μM). The results of the cytotoxicity evaluation showed that Toxoplasma gondii growth was inhibited at non-cytotoxic concentrations for the mammalian L929 fibroblast (CC₃₀ ∼ 880 μM). The most active compound 3k showed tyrosinase inhibition effect, with IC₅₀ value of 328.5 μM. The binding energies calculated for compounds 3a-3e, 3k are strongly correlated with the experimentally determined values of tyrosinase inhibition activity. Moreover, the binding energies corresponding to the same ligands and calculated for both tyrosinase and tyrosine hydroxylase are also correlated with each other, suggesting that tyrosinase inhibitors may also have an inhibitory effect on tyrosine hydroxylase. Compounds 3j and 3k have also very strong antioxidant activity (IC₅₀ 15.9 and 15.5 μM), respectively, which is ten times higher than well-known antioxidant BHT.

Nitro-Group-Containing Drugs

The nitro group is considered to be a versatile and unique functional group in medicinal chemistry. Despite a long history of use in therapeutics, the nitro group has toxicity issues and is often categorized as a structural alert or a toxicophore, and evidence related to drugs containing nitro groups is rather contradictory. In general, drugs containing nitro groups have been extensively associated with mutagenicity and genotoxicity. In this context, efforts toward the structure-mutagenicity or structure-genotoxicity relationships have been undertaken. The current Perspective covers various aspects of agents that contain nitro groups, their bioreductive activation mechanisms, their toxicities, and approaches to combat their toxicity issues. In addition, recent advances in the field of anticancer, antitubercular and antiparasitic agents containing nitro groups, along with a patent survey on hypoxia-activated prodrugs containing nitro groups, are also covered.

Design of Radioiodinated Pharmaceuticals: Structural Features Affecting Metabolic Stability towards in Vivo Deiodination

Radioiodinated pharmaceuticals are convenient tracers for clinical and research investigations because of the relatively long half-lives of radioactive iodine isotopes (i.e., 123I, 124I, and 131I) and the ease of their chemical insertion. Their application in radionuclide imaging and therapy may, however, be hampered by poor in vivo stability of the C-I bond. After an overview of the use of iodine in biology and nuclear medicine, we present here a survey of the catabolic pathways for iodinated xenobiotics, including their biodistribution, accumulation, and biostability. We summarize successful rational improvements in the biostability and conclude with general guidelines for the design of stable radioiodinated pharmaceuticals. It appears to be necessary to consider the whole molecule, rather than the radioiodinated fragment alone. Iodine radionuclides are generally retained in vivo on sp2 carbon atoms in iodoarenes and iodovinyl moieties, but not in iodinated heterocycles or on sp3 carbon atoms. Iodoarene substituents also have an influence, with increased in vivo deiodination in the cases of iodophenols and iodoanilines, whereas methoxylation and difluorination improve biostability.

Synthesis and biological evaluation of N-alkyl naphthoimidazoles derived from β-lapachone against Trypanosoma cruzi bloodstream trypomastigotes

The QSAR study of 34 2-aryl-naphthoimidazoles screened so far revealed that σi is the most important factor for their lytic activity on the bloodstream trypomastigote forms of T. cruzi, the etiologic agent of Chagas disease. Based on this result, 16 new N-alkyl-naphthoimidazoles derived from 6,6-dimethyl-3,4,5,6-tetrahydrobenzo[7,8]chromene[5,6-d]imidazole (the product of the reaction of β-lapachone with paraformaldehyde) by its reaction with halo-alkanes were prepared and evaluated against the parasite and peritoneal macrophages. The N1-n-hexyl and N3-n-hexyl naphthoimidazoles were 2.2 and 3.2 times more active than the standard drug benznidazole with selectivity indices of 2.7 and 13.4, respectively.

Nitrotriazole-Based Compounds as Antichagasic Agents in a Long-Treatment In Vivo Assay

3-Nitrotriazole-based compounds belonging to various chemical subclasses were found to be very effective against Chagas disease both in vitro and in vivo after a short administration schedule. In this study, five compounds with specific characteristics were selected to be administered for longer periods of time to mice infected with the virulent Trypanosoma cruzi Y strain to further evaluate their effectiveness as antichagasic agents and whether or not potential adverse effects occur. Benznidazole was included for comparison purposes. Complete parasitemia depletion, weight gain, 100% survival, and a lack of myocardial inflammation were observed with four of the compounds and benznidazole administered intraperitoneally at 15 or 20 mg/kg of body weight/day for 40 days. There was a significant reduction in the number of treatment days (number of doses) necessary to induce parasitemia suppression with all four compounds compared to that required with benznidazole. Partial cures were obtained with only one compound tested at 15 mg/kg/day and on the schedule mentioned above but not with benznidazole. Taken together, our data suggest that these compounds demonstrate potent trypanocidal activity comparable to or better than that of the reference drug, benznidazole, when they are administered at the same dose and on the same schedule.

Rational design of nitrofuran derivatives: Synthesis and valuation as inhibitors of Trypanosoma cruzi trypanothione reductase

The rational design and synthesis of a series of 5-nitro-2-furoic acid analogues are presented. The trypanocidal activity against epimastigote forms of Trypanosoma cruzi and the toxic effects on human HeLa cells were tested. Between all synthetic compounds, three of thirteen had an IC₅₀ value in the range of Nfx, but compound 13 exhibited an improved effect with an IC₅₀ of 1.0 ± 0.1 μM and a selective index of 70 in its toxicity against HeLa cells. We analyzed the activity of compounds 8, 12 and 13 to interfere in the central redox metabolic pathway in trypanosomatids, which is dependent of reduced trypanothione as the major pivotal thiol. The three compounds behaved as better inhibitors of trypanothione reductase than Nfx (Ki values of 118 μM, 61 μM and 68 μM for 8, 12 and 13, respectively, compared with 245 μM for Nfx), all following an uncompetitive enzyme inhibition pattern. Docking analysis predicted a binding of inhibitors to the enzyme-substrate complex with binding energy calculated in-silico that supports such molecular interaction.

Synthesis and antibacterial evaluation of new N- and S-glycosides analogues with dinitrophenyl-substituted heterocyclic bases

Four N- and S-glycosides 13-16 having nucleobases 7-12 binding to sugar molecules from one side and to 3,5-dinitrophenyl moieties from another side were synthesized from 3,5-dinitrobenzoic acid 2. The synthetic intermediates, hydrazide 5 and thiosemicarbazide 6 regarded as important key compounds for the synthesis of nucleobases 7-12, each was obtained by two approaches. Structures of synthesized compounds were determined spectroscopically. Antibacterial activities for synthetic intermediates and glycosides were assessed using the paper disk diffusion method against Gram-negative bacteria: Pseudomonas aeruginosa, Pseudomonas fluorescens, and Escherichia coli and Gram-positive bacteria: Bacillus cereus and Staphylococcus aureus. Some of the synthetic compounds showed variant activity against some of the microorganisms tested. Nucleobases 8-10 and 12 showed moderate to slight activity against microorganisms under test at relatively high concentration, while the N-glycosides 14 and 15 exhibited persistent effect even at lower concentrations. Commercially available antibiotics polymyxine and oxytetracycline were used as positive controls.

Nitrotriazole-based acetamides and propanamides with broad spectrum antitrypanosomal activity

3-Nitro-1H-1,2,4-triazole-based acetamides bearing a biphenyl- or a phenoxyphenyl moiety have shown remarkable antichagasic activity both in vitro and in an acute murine model, as well as substantial in vitro antileishmanial activity but lacked activity against human African trypanosomiasis. We have shown now that by inserting a methylene group in the linkage to obtain the corresponding propanamides, both antichagasic and in particular anti-human African trypanosomiasis potency was increased. Therefore, IC50 values at low nM concentrations against both T. cruzi and T. b. rhodesiense, along with huge selectivity indices were obtained. Although several propanamides were active against Leishmania donovani, they were slightly less potent than their corresponding acetamides. There was a good correlation between lipophilicity (clogP value) and trypanocidal activity, for all new compounds. Type I nitroreductase, an enzyme absent from the human host, played a role in the activation of the new compounds, which may function as prodrugs. Antichagasic activity in vivo was also demonstrated with representative propanamides.

Design, synthesis, molecular docking and biological evaluation of thiophen-2-iminothiazolidine derivatives for use against Trypanosoma cruzi

In this study, we designed and synthesized a series of thiophen-2-iminothiazolidine derivatives from thiophen-2-thioureic with good anti-Trypanosoma cruzi activity. Several of the final compounds displayed remarkable trypanocidal activity. The ability of the new compounds to inhibit the activity of the enzyme cruzain, the major cysteine protease of T. cruzi, was also explored. The compounds 3b, 4b, 8b and 8c were the most active derivatives against amastigote form, with significant IC50 values between 9.7 and 6.03μM. The 8c derivative showed the highest potency against cruzain (IC50=2.4μM). Molecular docking study showed that this compound can interact with subsites S1 and S2 simultaneously, and the negative values for the theoretical energy binding (Eb=-7.39kcal·mol(-1)) indicates interaction (via dipole-dipole) between the hybridized sulfur sp(3) atom at the thiazolidine ring and Gly66. Finally, the results suggest that the thiophen-2-iminothiazolidines synthesized are important lead compounds for the continuing battle against Chagas disease.

Antitrypanosomal activity of 5-nitro-2-aminothiazole-based compounds

A small series of 5-nitro-2-aminothiazole-based amides containing arylpiperazine-, biphenyl- or aryloxyphenyl groups in their core were synthesized and evaluated as antitrypanosomatid agents. All tested compounds were active or moderately active against Trypanosoma cruzi amastigotes in infected L6 cells and Trypanosoma brucei brucei, four of eleven compounds were moderately active against Leishmania donovani axenic parasites while none were deemed active against T. brucei rhodesiense. For the most active/moderately active compounds a moderate selectivity against each parasite was observed. There was good correlation between lipophilicity (clogP value) and antileishmanial activity or toxicity against L6 cells. Similarly, good correlation existed between clogP values and IC50 values against T. cruzi in structurally related subgroups of compounds. Three compounds were more potent as antichagasic agents than benznidazole but were not activated by the type I nitrorectusase (NTR).

3-Nitrotriazole-based piperazides as potent antitrypanosomal agents

Novel linear 3-nitro-1H-1,2,4-triazole-based piperazides were synthesized and evaluated as antitrypanosomal agents. In addition, some bisarylpiperazine-ethanones which were formed as by-products were also screened for antiparasitic activity. Most 3-nitrotriazole-based derivatives were potent and selective against Trypanosoma cruzi parasites, but only one displayed these desired properties against Trypanosoma brucei rhodesiense. Moreover, two 3-nitrotriazole-based chlorophenylpiperazides were moderately and selectively active against Leishmania donovani. Although the bisarylpiperazine-ethanones were active or moderately active against T. cruzi, none of them demonstrated an acceptable selectivity. In general, 3-nitrotriazole-based piperazides were less toxic to host L6 cells than the previously evaluated 3-nitrotriazole-based piperazines and seven of 13 were 1.54- to 31.2-fold more potent antichagasic agents than the reference drug benznidazole. Selected compounds showed good ADMET characteristics. One potent in vitro antichagasic compound (3) was tested in an acute murine model and demonstrated antichagasic activity after a 10-day treatment of 15 mg/kg/day. However, neither compound 3 nor benznidazole showed a statistically significant P value compared to control due to high variability in parasite burden among the untreated animals. Working as prodrugs, 3-nitrotriazole-based piperazides were excellent substrates of trypanosomal type I nitroreductases and constitute a novel class of potentially effective and more affordable antitrypanosomal agents.