Synthesis, antimalarial, antiproliferative, and apoptotic activities of benzimidazole-5-carboxamide derivatives

Design, synthesis and evaluation of novel carboline-triazole hybrids as promising antimalarial agents

A series of twenty-four carboline-triazole derivatives were synthesized using a molecular hybridization approach and evaluated for their antimalarial activity against Plasmodium parasites. Ten compounds exhibited strong in vitro antimalarial activity against both chloroquine-sensitive Pf3D7 and chloroquine-resistant PfK1 strains, with IC50 values ranging from 0.21 to 0.98 μM and 0.32-0.82 μM, respectively. Among them, compound 15k demonstrated significant in vivo antimalarial activity against P. yoelii N67 in Swiss mice. Notably, compounds 15e, 15f, and 15k also inhibited P. berghei liver stage development with IC50 values ranging from 4.81 to 7.58 μM. Evaluation of in vitro pharmacokinetic parameters revealed that the synthesized carboline-triazole conjugate 15k fulfils the criteria for orally active drug development. These findings highlight the potential of this scaffold as a promising framework for the development of antimalarial agents.

Benzimidazole scaffold as a potent anticancer agent with different mechanisms of action (2016-2023)

Benzimidazole scaffolds have potent anticancer activity due to their structure similarity to nucleoside. In addition, benzimidazoles could function as hydrogen donors or acceptors and bind to different drug targets that participate in cancer progression. The literature had many anticancer agents containing benzimidazole cores that gained much interest. Provoked by our endless interest in benzimidazoles as anticancer agents, we summarized the successful trials of the benzimidazole scaffolds in this concern. Moreover, we discuss the substantial opportunities in cancer treatment using benzimidazole-based drugs that may direct medicinal chemists for a compelling future design of more active chemotherapeutic agents with potential clinical applications. The uniqueness of this work lies in the highlighted benzimidazole scaffold hybridization with different molecules and benzimidazole-metal complexes, detailed mechanisms of action, and the IC50 of the developed compounds determined by different laboratories after 2015.

Design, synthesis, antimalarial activity, and in-silico studies of new benzimidazole/pyridine hybrids as dihydrofolate reductase inhibitors

Molecular hybridization of substituted 2-phenylbenzimidazole and pyridine moieties afforded a new series of antimalarial targeting compounds 5a-l. They were assessed against both chloroquine resistant -W2 (CR-W2) and chloroquine sensitive-D6 (CS-D6) strains of P. falciparum. Artemisinin and chloroquine were used as standards drugs. Results revealed that compounds 5e, 5j, 5k and 5l were the most effective against CS-D6 P. falciparum strain with IC50 values ranged between 0.019 and 0.056 µM and selectivity index values of 7551.95-13642.10. In addition to 5j and 5k derivatives, another four tested compounds 5c, 5d, 5f and 5g exerted effective antimalarial activity against CR-W2 strain of P. falciparum, their IC50 values were between 0.046 and 0.253 µM with high selectivity index values ranged from 2610.23 to 1024.50. Upon assessing DHFR inhibitory activity of the energetic derivatives, compounds 5j, 5k, and 5e exhibited IC50 values of 0.72, 3.95, and 5.31 µM, respectively, in comparison to the reference medication trimethoprim, which has an IC50 of 13.36 µM. Moreover, molecular dynamic simulations and docking experiments were applied to the most active derivative, 5j, into the catalytic binding site of wild-PfDHFR-TS, were done and showed interesting binding profiles and affinities. Furthermore, in silico physicochemical and pharmacokinetic parameters were predicted.

Synthesis, Leishmanicidal, Trypanocidal, Antiproliferative Assay and Apoptotic Induction of (2-Phenoxypyridin-3-yl)naphthalene-1(2H)-one Derivatives

The coexistence of leishmaniasis, Chagas disease, and neoplasia in endemic areas has been extensively documented. The use of common drugs in the treatment of these pathologies invites us to search for new molecules with these characteristics. In this research, we report 16 synthetic chalcone derivatives that were investigated for leishmanicidal and trypanocidal activities as well as for antiproliferative potential on eight human cancers and two nontumor cell lines. The final compounds 8−23 were obtained using the classical base-catalyzed Claisen−Schmidt condensation. The most potent compounds as parasiticidal were found to be 22 and 23, while compounds 18 and 22 showed the best antiproliferative activity and therapeutic index against CCRF-CEM, K562, A549, and U2OS cancer cell lines and non-toxic VERO, BMDM, MRC-5, and BJ cells. In the case of K562 and the corresponding drug-resistant K562-TAX cell lines, the antiproliferative activity has shown a more significant difference for compound 19 having 10.3 times higher activity against the K562-TAX than K562 cell line. Flow cytometry analysis using K562 and A549 cell lines cultured with compounds 18 and 22 confirmed the induction of apoptosis in treated cells after 24 h. Based on the structural analysis, these chalcones represent new compounds potentially useful for Leishmania, Trypanosoma cruzi, and some cancer treatments.

Benzimidazole hybrids as anticancer drugs: An updated review on anticancer properties, structure-activity relationship, and mechanisms of action (2019-2021)

Cancer, characterized by a deregulation of the cell cycle which mainly results in a progressive loss of cellular differentiation and uncontrolled cellular growth, remains a prominent cause of death across the world. Almost all currently available anticancer agents used in clinical practice have developed multidrug resistance, creating an urgent need to develop novel chemotherapeutics. Benzimidazole derivatives could exert anticancer properties through diverse mechanisms, inclusive of the disruption of microtubule polymerization, the induction of apoptosis, cell cycle (G2/M) arrest, antiangiogenesis, and blockage of glucose transport. Moreover, several benzimidazole-based agents have already been approved for the treatment of cancers. Hence, benzimidazole derivatives are useful scaffolds for the development of novel anticancer agents. In particular, benzimidazole hybrids could exert dual or multiple antiproliferative activities and had the potential to overcome drug resistance, demonstrating the potential of benzimidazole hybrids as potential prototypes for clinical deployment in the control and eradication of cancers. The purpose of the present review article is to provide a comprehensive landscape of benzimidazole hybrids as potential anticancer agents, and the structure-activity relationship as well as mechanisms of action are also discussed to facilitate the further rational design of more effective candidates, covering articles published from 2019 to 2021.

Experimental and computational studies of an antiplasmodial derivative of allantoin; antimycobacterial essential oil from Cordia batesii WERNHAM (Boraginaceae)

Background

Chemical and pharmacological investigations were performed on the stems of Cordia batesii (Boraginaeae); chemical studies included quantum calculations applied on a newly described compound.

Results

A new derivative of allantoin (1) named batesiin (2) was characterized. Thirteen other known compounds involving allantoin (1) were either isolated or identified. GC–MS enabled the identification of six compounds from a fraction containing essential oil. MeOH extract and some isolated compounds were tested in vitro against Pf7G8 CQS and Pf Dd2 CQR strains of Plasmodium falciparum; extract disclosed a moderate antiplasmodial activity (IC₅₀ = 50 μg mL⁻¹). Meantime, the CH₂Cl₂ extract and essential oil fraction were tested on a resistant mycobacterial strain of Mycobacterium tuberculosis; a potent antimycobacterial activity with a MIC = 9.52 μg mL⁻¹ was deduced from essential oil. Density functional theory (DFT) calculations were carried on batesiin (2). Calculated chemical shifts at B3LYP/6-31G(d,p) and MPW1PW91/6-31G+(d,p) showed much better correlations with the experimental data. Time dependent DFT at B3LYP/6-31G+(d,p) displayed a major absorption band 3.01 nm higher than the experimental value.

Conclusion

Cordia batesii can be considered as promising in search of compounds with antimalarial and antitubercular properties. DFT studies are very helpful when trying to learn more about the spectroscopic insights of a derivative of allantoin (1).

Synthesis and antimalarial and anticancer evaluation of 7-chlorquinoline-4-thiazoleacetic derivatives containing aryl hydrazide moieties

Twelve 7-chloroquinoline derivatives were designed and synthesized using the principle of molecular hybridization through the coupling of 2-[2-(7-chloroquinolin-4-ylthio)-4-methylthiazol-5-yl]acetic acid 1 with various benzoyl hydrazines 2a-l. The synthetic compounds were tested as antimalarials. Some of them showed an efficient in vitro activity as inhibitors of β-hematin formation and an in vivo activity in a murine model, resulting in compounds 8 and 9 as the most active ones with IC₅₀ values of 0.65 ± 0.09 and 0.64 ± 0.16 µM, respectively. The effects of the compounds on the cell viability, cell cycle, and apoptosis induction of A549 and MCF-7 cancer cell lines were also examined. Our data showed that compounds 6 and 12 were the most active agents, decreasing the cell viability of MCF-7 cells with IC₅₀ values of 15.41 and 12.99 µM, respectively. None of the compounds analyzed significantly affected the viability of peripheral blood mononuclear cells. Also, significant induction of apoptosis was observed when both cancer cell lines were incubated with compounds 6 and 12. In MCF-7 cells, treatment with these compounds led to cell cycle arrest in the G0/G1 phase. The results obtained suggest that these structures may be useful in developing new therapies for malaria and cancer treatment.

Synthesis, cytotoxicity, pharmacokinetic profile, binding with DNA and BSA of new imidazo[1,2-a]pyrazine-benzo[d]imidazol-5-yl hybrids

Novel derivatives possessing imidazo[1,2-a]pyrazine and 1H-benzo[d]imidazole scaffolds were synthesized using Suzuki-Miyaura cross-coupling reactions. In vitro anticancer activities against NCI-60 cancer cell panels were tested at 10 µM concentration. The best results were obtained from substitution of two 1-cyclohexyl-1H-benzo[d]imidazole groups present at C-6 and C-8 positions of imidazo[1,2-a]pyrazine (31). Compound 31 was found to be cytotoxic against 51 cell lines and cytostatic against 8 cell lines with broad range of growth inhibitions (−98.48 to 98.86%). GI₅₀ value of compound 31 was found in the range of 0.80–2.87 µM for 59 human cancer cell lines at five-dose concentration levels. DNA binding study of potent compound 31 was suggested that this compound was intercalated into DNA base pairs with binding constant of 1.25 × 10⁴ M⁻¹. Compound 31 showed effective binding with bovine serum albumin (BSA) and presented binding constant value of 3.79 ×10⁴ M^-1. Pharmacokinetic studies revealed that all compounds are following Lipinski’s rule of five and expected to be orally active.

An epigrammatic status of the 'azole'-based antimalarial drugs

The development of multidrug resistance in the malarial parasite has sabotaged majority of the eradication efforts by restraining the inhibition profile of first line as well as second line antimalarial drugs, thus necessitating the development of novel pharmaceutics constructed on appropriate scaffolds with superior potency against the drug-resistant and drug-susceptible Plasmodium parasite. Over the past decades, the infectious malarial parasite has developed resistance against most of the contemporary therapeutics, thus necessitating the rational development of novel approaches principally focused on MDR malaria. This review presents an epigrammatic collation of the epidemiology and the contemporary antimalarial therapeutics based on the 'azole' motif.

Synthesis and biological activity of 2-[2-(7-chloroquinolin-4-ylthio)-4-methylthiazol-5-yl]-N-phenylacetamide derivatives as antimalarial and cytotoxic agents

A novel series of 2-[2-(7-chloroquinolin-4-ylthio)-4-methylthiazol-5-yl]- N-phenylacetamide derivatives is synthesized via substitution with 2-mercapto-4-methyl-5-thiazoleacetic acid at position 4 of 4,7-dichloroquinoline to obtain an intermediate acetic acid derivative. The chemical behavior of these reactants was investigated using different reaction conditions to optimize the nucleophilic substitution at position 4. The final compounds are prepared using a modified version of the Steglich esterification reaction between the acetic acid intermediate 3 and different anilines. The structures are confirmed by infrared, 1H, 13C, distortionless enhancement by polarization transfer 135°, Correlated Spectroscopy, heteronuclear correlation spectroscopy and (Long range HETCOR using three BIRD pulses) FLOCK-NMR spectral studies, and by elemental analysis. The synthesized compounds are tested in vitro and in vivo for their potential antimalarial and anticancer activities, with derivative 11 being the most promising candidate.

Synthesis and antimalarial activity of (S)-methyl-(7-chloroquinolin-4-ylthio)acetamidoalquilate derivatives

The synthesis of five new ( S)-methyl-(7-chloroquinolin-4-ylthio)acetamidoalquilate derivatives is carried out under a modified version of the Steglich esterification reaction between different l-amino acid methyl esters and 2-(7-chloroquinolin-4-ylthio)acetic acid. Two of the compounds showed significant inhibition (>50%) of β-hematin formation. The two active structures were tested in vivo as potential antimalarials in mice infected with Plasmodium berghei ANKA, a chloroquine susceptible strain. Compounds 6b and 6e exhibited antimalarial activity comparable to that of chloroquine.