Urea-based anticancer agents. Exploring 100-years of research with an eye to the future

Insecticidal effect of new synthesized chalcone derivatives on Caribbean fruit fly, Anastrepha suspensa

In this present study, new chalcone derivatives were synthesized from 4-aminoacetophenone, which were confirmed by spectroscopic methods. The toxic risks of chalcones to humans and the environment were investigated by a web-based platform called ADMETlab. With this program, the possible toxic effects of the compounds on liver, respiratory system, and eyes were evaluated. For the topical insecticidal activity, adult female Caribbean fruit fly, Anastrepha suspensa, was targeted. Results of the toxicity tests showed that chalcone derivatives are effective against female A. suspensa. Among the synthesized chalcones, 1-(4-cinnamoylphenyl)-3-(p-tolyl)urea (2) exhibited the greatest insecticidal activity, resulting in 73 % mortality at 100 µg/fly after 24 h, whereas other derivatives showed less than 30 % mortality. Our results demonstrate that insecticidal activity may be modulated by the presence of a certain phenyl ring in the structure of derivative 2 and, therefore, has potential for design of efficient chemicals for tephritid fruit fly management.

Sustainable urea treatment by environmental-friendly and highly hydrophilic vesicle-like iron phosphate-based carbon

Despite the versatile potential applications of urea, its unfavorable characteristics for conventional treatment methods hinder its utilization. Therefore, this study developed vesicle-like iron phosphate-based carbon (IP@C400) as a breakthrough urea removal and recovery material for a wide range of urea-containing sources. IP@C400 rapidly exhibited an exceptional capacity (2242 mg/g in 1 h) across a wide range of pH, even in synthetic hemodialysis wastewater with high urea concentrations and diverse co-existing components, compared with the 60 prominent adsorbents. The adsorption process followed dual Pseudo-kinetic, Langmuir-isotherm models with the involvement of primary robust physical (i.e., H-bonding and electrostatic interaction) and chemical mechanisms (i.e., hydrolysis). Remarkably, IP@C400 can maintain high urea removal (90 %) or recovery efficiency (95 %) even after 10 cycles with minimal leakages of Fe and P (far below WHO and EUWFD standards)-a significant improvement over disposable options. IP@C400 could also perform efficiently on batch and a new approach integrating with a naturally accessible material based on the fixed-bed column using low-range urea realistic samples, achieving 65.2 L water over 10 cycles with undetected urea, neutral pH, and well-aligned water safety standards with a minimal adsorbent dose (0.1 g.L-1) and economical cost ($0.05 L-1). Lastly, its environmentally friendly nature, which contains essential nutrients for plant growth, further enhances its recyclability after release. Thus, IP@C400 offers a solution to environmental sustainability and the urgent ultrapure water issue that industries are facing.

Diphenyl urea-benzylidene acetohydrazide hybrids as fibroblast growth factor receptor 1 inhibitors and anticancer agents

Molecular hybridization between diphenyl urea and benzylidene acetohydrazide was adopted for the design of a new series of FGFR-1 targeting cancer. The designed series was synthesized and submitted to NCI-USA to be screened for their growth inhibitory activity on NCI cancer cell lines. Some of the synthesized hybrids displayed promising growth inhibitory activity on NCI cancer cell lines with a mean GI% between 70.39% and a lethal effect. Compounds 9a, 9i, 9j, and 9n-p were further selected for a five-dose assay and all the tested candidates showed promising antiproliferative activity with GI50 reaching the submicromolar range. Encouraged by the potent activity of 9a on colon cancer on the one hand and the well-known overexpression of FGFR-1 in it on the other hand, it was further selected as a representative example to be evaluated for its mechanism on the cell cycle and apoptosis of HCT116 cell line. Interestingly, 9a was found to pause the cell cycle of the HCT116 cell line at the G1 phase and induced late apoptosis. In parallel, all the synthesized hybrids 9a-p were examined for their potential to inhibit FGFR-1 at 10 µM. Compounds 9a, 9g, 9h, and 9p were found to have potent inhibitory activity with % inhibition = 63.04%, 58.31%, 60.87% and 79.84%, respectively. Molecular docking simulation of 9a in the binding pocket of FGFR-1 confirms its capability to achieve the characteristic interactions of the type II FGFR-1 inhibitors. Exploration of the ADME properties of 9a-p by SwissADME web tool proved their satisfactory physicochemical properties for the discovery of new anticancer hits.

A Small Molecule Agonist of Krüppel-Like Factor 15 in Proteinuric Kidney Disease

Key Points

Background

Podocyte loss is the major driver of primary glomerular diseases such as FSGS. While systemic glucocorticoids remain the initial and primary therapy for these diseases, high-dose and chronic use of glucocorticoids is riddled with systemic toxicities. Krüppel-like factor 15 (KLF15) is a glucocorticoid-responsive gene, which is essential for the restoration of mature podocyte differentiation markers and stabilization of actin cytoskeleton in the setting of cell stress. Induction of KLF15 attenuates podocyte injury and glomerulosclerosis in the setting of cell stress.

Methods

A cell-based high-throughput screen with a subsequent structure–activity relationship study was conducted to identify novel agonists of KLF15 in human podocytes. Next, the agonist was tested in cultured human podocytes under cell stress and in three independent proteinuric models (LPS, nephrotoxic serum nephritis, and HIV-1 transgenic mice). A combination of RNA sequencing and molecular modeling with experimental validation was conducted to demonstrate the direct target of the agonist.

Results

The high-throughput screen with structure–activity relationship study identified BT503, a urea-based compound, as a novel agonist of KLF15, independent of glucocorticoid signaling. BT503 demonstrated protective effects in cultured human podocytes and in three independent proteinuric murine models. Subsequent molecular modeling with experimental validation shows that BT503 targets the inhibitor of nuclear factor kappa-B kinase complex by directly binding to inhibitor of nuclear factor kappa-B kinase subunit beta to inhibit canonical NF-κB signaling, which, in turn, restores KLF15 under cell stress, thereby rescuing podocyte loss and ameliorating kidney injury.

Conclusions

By developing and validating a cell-based high-throughput screen in human podocytes, we identified a novel agonist for KLF15 with salutary effects in proteinuric murine models through direct inhibition of inhibitor of nuclear factor kappa-B kinase subunit beta kinase activity.

A green Heck reaction protocol towards trisubstituted alkenes, versatile pharmaceutical intermediates

The Heck reaction is widely employed to build a variety of biologically relevant scaffolds and has been successfully implemented in the production of active pharmaceutical ingredients (APIs). Typically, the reaction with terminal alkenes gives high yields and stereoselectivity toward the trans-substituted alkenes product, and many green variants of the original protocol have been developed for such substrates. However, these methodologies may not be applied with the same efficiency to reactions with challenging substrates, such as internal olefins, providing trisubstituted alkenes. In the present work, we have implemented a Heck reaction protocol under green conditions to access trisubstituted alkenes as final products or key intermediates of pharmaceutical interest. A set of preliminary experiments performed on a model reaction led to selecting a simple and green setup based on a design of experiments (DoE) study. In such a way, the best experimental conditions (catalyst loading, equivalents of alkene, base and tetraalkylammonium salt, composition, and amount of solvent) have been identified. Then, a second set of experiments were performed, bringing the reaction to completion and considering additional factors. The protocol thus defined involves using EtOH as the solvent, microwave (mw) irradiation to achieve short reaction times, and the supported catalyst Pd EnCat®40, which affords an easier recovery and reuse. These conditions were tested on different aryl bromides and internal olefines to evaluate the substrate scope. Furthermore, with the aim to limit as much as possible the production of waste, a simple isomerization procedure was developed to convert the isomeric byproducts into the desired conjugated E alkene, which is also the thermodynamically favoured product. The approach herein disclosed represents a green, efficient, and easy-to-use handle towards different trisubstituted alkenes via the Heck reaction.

Synthesis and Identification of Heterobivalent Anticancer Compounds Containing Urea and 5-Arylidene-2-Thiohydantoin Motifs

Urea and thiohydantoin are among the important privileged structures for drug discovery. We have developed a synthetic approach to the high-throughput synthesis of the heterobivalent compounds containing both urea and 5-arylidene-2-thiohydantoin functional groups. This synthetic methodology was applied to the synthesis of a mixture-based library containing a total of 5280 compounds in a positional scanning format. The library was screened for its antiproliferative activity against cancer cells using a tetrazolium dye (MTT) based assay. Deconvolution of the library identified six hit compounds exhibiting moderate inhibitory potency against cancer cell proliferation.

Identification of novel ureido benzothiophenes as dual VEGFR-2/EGFR anticancer agents

Presently, dual-targeting by a single small molecule stands out as a fruitful cancer-fighting strategy. Joining the global effort to fight cancer, a leading cause of death worldwide, we report in this study a novel set for benzothiophene-based aryl urea derivatives as potential anti-proliferative candidates endowed with dual VEGFR-2/EGFR inhibitory activities. The prepared ureido benzothiophenes 6a-r have been evaluated for their anticancer action on a panel of tumor cell lines, namely PanC-1, MCF-7, and HepG2 cells. Most newly synthesized benzo[b]thiophene ureas disclosed effective cytotoxic activities against the examined cancer cell lines. In particular, compound 6q, with an appended 4-trifluoromethoxy group on the terminal phenyl ring, exhibited the most significant cytotoxic activity in MCF-7 with IC50 3.86 ± 0.72 ug/mL; IC50 of 3.65 ± 0.18 ug/ml in PanC-1 cell line and an IC50 of 4.78 ± 0.06 ug/ml in HepG2. After that, derivatives that exhibited the most potent cytotoxic activities (6g, 6j, 6q, and 6r) were further evaluated as VEGFR-2 and EGFR inhibitors. Fortunately, they displayed low nanomolar IC50 values against both enzymes, where compound 6q emerged to possess superior inhibitory effects towards both EGFR and VEGFR-2 with IC50 46.6 nM and 11.3 nM simultaneously compared to the reference medications Erlotinib and Sorafenib, respectively. The docked structure of 6q within the catalytic region of VEGFR-2 and EGFR kinases was acquired and studied so that we could investigate potential binding mechanisms for the target ureido benzothiophenes. Hence, the benzothiophene-based aryl urea scaffold has great potential for advancing the development of highly effective dual inhibitors targeting both EGFR and VEGFR-2, which can serve as effective candidates for anticancer therapy.

Impact of trifluoromethyl and sulfonyl groups on the biological activity of novel aryl-urea derivatives: synthesis, in-vitro, in-silico and SAR studies

We designed and prepared a novel series of urea derivatives with/without sulfonyl group in their structures to investigate the impact of the sulfonyl group on the biological activity of the evaluated compounds. Antibacterial investigations indicated that derivatives 7, 8, 9, and 11 had the most antibacterial property of all the compounds examined, their minimum inhibitory concentrations (MICs) determined against B. mycoides, E. coli, and C. albicans, with compound 8 being the most active at a MIC value of 4.88 µg/mL. Anti-cancer activity has been tested against eight human cancer cell lines; A549, HCT116, PC3, A431, HePG2, HOS, PACA2 and BJ1. Compounds 7, 8 and 9 emerged IC50 values better than Doxorubicin as a reference drug. Compounds 7 and 8 showed IC50 = 44.4 and 22.4 μM respectively against PACA2 compared to Doxorubicin (IC50 = 52.1 μM). Compound 9 showed IC50 = 17.8, 12.4, and 17.6 μM against HCT116, HePG2, and HOS, respectively. qRT-PCR revealed the down-regulation of PALB2 in compounds 7 and 15 treated PACA2 cells. Also, the down-regulation of BRCA1 and BRCA2 was shown in compound 7 treated PC3 cells. As regard A549 cells, compound 8 decreased the expression level of EGFR and KRAS genes. While compounds 7 and 9 down-regulated TP53 and FASN in HCT116 cells. Molecular docking was done against Escherichia coli enoyl reductase and human Son of sevenless homolog 1 (SOS1) and the results showed the promising inhibition of the studied proteins.

Synthesis, Characterization, and Anticancer Activity of New N,N'-Diarylthiourea Derivative against Breast Cancer Cells

The goal of the current study was to prepare two new homologous series of N,N'-diarylurea and N,N'-diarylthiourea derivatives to investigate the therapeutic effects of these derivatives on the methodologies of inhibition directed on human MCF-7 cancer cells. The molecular structures of the prepared derivatives were successfully revealed through elemental analyses, 1H-NMR, 13C-NMR and FT-IR spectroscopy. The cytotoxic results showed that Diarylthiourea (compound 4) was the most effective in suppressing MCF-7 cell growth when compared to all other prepared derivatives, with the most effective IC50 value (338.33 ± 1.52 µM) after an incubation period of 24 h and no cytotoxic effects on normal human lung cells (wi38 cells). Using the annexin V/PI and comet tests, respectively, treated MCF-7 cells with this IC50 value of the Diarylthiourea 4 compound displayed a considerable increase in early and late apoptotic cells, as well as an intense comet nucleus in comparison to control cells. An arrest of the cell cycle in the S phase was observed via flow cytometry in MCF-7 cells treated with the Diarylthiourea 4 compound, suggesting the onset of apoptosis. Additionally, ELISA research showed that caspase-3 was upregulated in MCF-7 cells treated with compound 4 compared to control cells, suggesting that DNA damage induced by compound 4 may initiate an intrinsic apoptotic pathway and activate caspase-3. These results contributed to recognizing that the successfully prepared Diarylthiourea 4 compound inhibited the proliferation of MCF-7 cancer cells by arresting the S cell cycle and caspase-3 activation via an intrinsic apoptotic route. These results, however, need to be verified through in vivo studies utilizing an animal model.

Conformational study into N-alkyl-N'-aryl ureas to inform drug discovery

Ureas are an important functional group in small molecule drugs as well as having wider applications in organic chemistry. Understanding of their conformation is of critical importance for rational design of urea-containing bioactive compounds. Whilst the conformational preferences of biaryl ureas have been extensively studied, very little attention has been paid to alkylated analogues. We carried out a systematic study of N-aryl (phenyl and pyridyl)-N'-cyclopentyl ureas with differing N-methylation patterns using Well Tempered Metadynamics at a semi-empirical level in implicit water (GBSA) using Well-Tempered Metadynamics to generate their conformational free-energy landscapes. Geometries and energetics of the most relevant configurations are further refined using DFT level of theory. Validation for the computation was obtained by synthesis of all 8 analogues followed by conformational studies by X-ray crystallography and NMR. These findings reveal that the methylation pattern significantly affects the conformational preference of the system. Most notably, N-phenyl-N'-cyclopentyl urea is shown to adopt both the trans-trans, and cis-trans conformations with equal energy and that the cis-trans conformation can be significantly stabilised by the presence of an internal hydrogen bond to the N'-hydrogen. This study will be of utility for the design of N-alkyl-N'-aryl ureas as drug candidates.

Hybrids of Sterically Hindered Phenols and Diaryl Ureas: Synthesis, Switch from Antioxidant Activity to ROS Generation and Induction of Apoptosis

The utility of sterically hindered phenols (SHPs) in drug design is based on their chameleonic ability to switch from an antioxidant that can protect healthy tissues to highly cytotoxic species that can target tumor cells. This work explores the biological activity of a family of 45 new hybrid molecules that combine SHPs equipped with an activating phosphonate moiety at the benzylic position with additional urea/thiourea fragments. The target compounds were synthesized by reaction of iso(thio)cyanates with C-arylphosphorylated phenols containing pendant 2,6-diaminopyridine and 1,3-diaminobenzene moieties. The SHP/urea hybrids display cytotoxic activity against a number of tumor lines. Mechanistic studies confirm the paradoxical nature of these substances which combine pronounced antioxidant properties in radical trapping assays with increased reactive oxygen species generation in tumor cells. Moreover, the most cytotoxic compounds inhibited the process of glycolysis in SH-SY5Y cells and caused pronounced dissipation of the mitochondrial membrane of isolated rat liver mitochondria. Molecular docking of the most active compounds identified the activator allosteric center of pyruvate kinase M2 as one of the possible targets. For the most promising compounds, 11b and 17b, this combination of properties results in the ability to induce apoptosis in HuTu 80 cells along the intrinsic mitochondrial pathway. Cyclic voltammetry studies reveal complex redox behavior which can be simplified by addition of a large excess of acid that can protect some of the oxidizable groups by protonations. Interestingly, the re-reduction behavior of the oxidized species shows considerable variations, indicating different degrees of reversibility. Such reversibility (or quasi-reversibility) suggests that the shift of the phenol-quinone equilibrium toward the original phenol at the lower pH may be associated with lower cytotoxicity.

Identification of a novel extracellular inhibitor of FGF2/FGFR signaling axis by combined virtual screening and NMR spectroscopy approach

The aberrant activation of the fibroblast growth factor 2 (FGF2)/fibroblast growth factor receptor (FGFR) signalling pathway drives severe pathologies, including cancer development and angiogenesis-driven pathologies. The perturbation of the FGF2/FGFR axis via extracellular allosteric small inhibitors is a promising strategy for developing FGFR inhibitors with improved safety and efficacy for cancer treatment. We have previously investigated the role of new extracellular inhibitors, such as rosmarinic acid (RA), which bind the FGFR-D2 domain and directly compete with FGF2 for the same binding site, enabling the disruption of the functional FGF2/FGFR interaction. To select ligands for the previously identified FGF2/FGFR RA binding site, NMR data-driven virtual screening has been performed on an in-house library of non-commercial small molecules and metabolites. A novel drug-like compound, a resorcinol derivative named RBA4 has been identified. NMR interaction studies demonstrate that RBA4 binds the FGF2/FGFR complex, in agreement with docking prediction. Residue-level NMR perturbations analysis highlights that the mode of action of RBA4 is similar to RA in terms of its ability to target the FGF2/FGFR-D2 complex, inducing perturbations on both proteins and triggering complex dissociation. Biological assays proved that RBA4 inhibited FGF2 proliferative activity at a level comparable to the previously reported natural product, RA. Identification of RBA4 chemical groups involved in direct interactions represents a starting point for further optimization of drug-like extracellular inhibitors with improved activity.