Diaryl Urea Research Articles

A comparative study of diaryl urea molecules with and without sulfonamide group on Carbonic anhydrase IX and XII inhibition and its consequence on breast cancer cells

To investigate the intrinsic relation between carbonic anhydrase inhibition and anticancer activity, we have prepared four sets of diaryl urea molecules and tested for the inhibition of hCA-IX and XII on two breast cancer cell lines. Among 21 compounds, compound J2 (with -SO2NH2 group) and J16 (without -SO2NH2 group) showed the best activity under normoxic and hypoxic conditions. The IC50 values of J16 for MDA-MB-231 and MCF-7 cells, under normoxic condition were 6.3 and 3.7 µM respectively, which are 1.9/3.3 and 15.8 times better than U-4-Nitro and SLC-0111 respectively. Whereas, under the hypoxic condition the corresponding values were 12.4 and 1.1 µM (MDA-MB-231 and MCF-7 cells respectively), which are equal/8 times better than U-4-Nitro. Whereas, J2 showed better IC50 value than U-4-Nitro (6.3 µM) under normoxic condition for both MDA-MB-231 and MCF-7 cells (1.9/2.7 times). Compound J2 inhibits the activity of hCA-IX and XII in nanomolar concentration [Ki values 4.09 and 9.10 nM respectively with selectivity ratio of 1.8 and 0.8 with hCA-II]. The crystal structure and modelling studies demonstrates that the inhibition of CAs arises due to the blocking of the CO2 coordination site of zinc in its catalytic domain. However, J16 was found to be unable to inhibit the activity of hCAs (Ki > 89000 nM). qPCR and western blot analysis showed a significant reduction (1.5 to 20 fold) of the transcription and expression of HIF1A, CA9 and CA12 genes in presence of J2 and J16. Both J2 and J16 found to reduce accumulation of HIF-1α protein by inhibiting the chaperone activity of hHSP70 with IC50 values of 19.4 and 15.3 µM respectively. Perturbation of the hCA-IX and XII activity by binding at active site or by reduced expression or by both leads to the decrease of intracellular pH, which resulted in concomitant increase of reactive oxygen species by 2.6/2.0 (MCF-7) and 2.9/1.8 (MDA-MB-231) fold for J2/J16. Increased cyclin D1 expression in presence of J2 and J16 was presumed to be indirectly responsible for the apoptosis of the cancer cells. Expression of the other apoptosis markers Bcl-2, Bim, caspase 9 and caspase 3 substantiated the apoptosis mechanism. However, decreased transcription/expression of HIF1A/HIF-1α and hCA-IX/XII also implies the inhibition of the extracellular signal-regulated kinase pathway by J2 and J16.

Diabetes mellitus drug discovery: insights into targeting feline and human amylin with small molecules

Background Type 2 diabetes (T2D) is a health concern for both humans and cats, with cases rising over the past decade. Around 70% of patients from either species exhibit pancreatic aggregates of islet amyloid polypeptide (IAPP), a protein that proves toxic upon misfolding. These misfolded protein aggregates congregate in the islets of Langerhans of the pancreas, diminishing the capability of β-cells to produce insulin and further perpetuating disease. Objective Our team’s drug discovery program is investigating newly synthesized compounds that could diminish aggregates of both human and feline IAPP, potentially disrupting the progression of T2D. Material and methods We prepared 24 compounds derived from diaryl urea, as ureas have previously demonstrated great potential at reducing accumulations of misfolded proteins. Biophysical methods were employed to analyze the anti-aggregation activity of these compounds at inhibiting and/or disrupting IAPP fibril formation in vitro. Results The results demonstrate that compounds 12 and 24 were most effective at reducing the fibrillization and aggregation of both human and feline IAPP. When compared with the control for each experiment, samples treated with either compound 12 or 24 exhibited fewer accumulations of amyloid-like fibrils. Conclusion Urea-based compounds, such as compounds 12 and 24, may prove crucial in future pre-clinical studies in the search for therapeutics for T2D.

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.

Electrochemical synthesis of biaryls by reductive extrusion from N,N’-diarylureas

The synthesis of biaryl compounds by the transition-metal free coupling of arenes is an important contemporary challenge, aiming to avoid the toxicity and cost profiles associated with the metal catalysts commonly used in the synthesis of these pharmaceutically relevant motifs. In this paper, we describe an electrochemical approach to the synthesis of biaryls in which aniline derivatives are coupled through the formation and reduction of a temporary urea linkage. The conformational alignment of the arenes in the N,N’-diaryl urea intermediates promotes C-C bond formation following single-electron reduction. Our optimized conditions are suitable for the synthesis of a variety of biaryls, including sterically hindered examples carrying ortho-substituents, representing complementary reactivity to most metal catalysed methods.

Novel 2-oxo-2-phenylethoxy and benzyloxy diaryl urea hybrids as VEGFR-2 inhibitors: Design, synthesis, and anticancer evaluation.

Two series of diaryl urea derivatives, 6a-k and 7a-n, were synthesized. All the newly synthesized compounds were tested against the NCI (US) cancer cell lines via SRB assay. The p-chloro-m-trifluoromethyl phenyl derivatives 6e-g and 7e-g showed the most potent cytotoxic activity with a GI50 value range of 1.2-15.9 µM. Furthermore, the p-fluorobenzyloxy diaryl urea derivative 7g revealed the most potent cytotoxicity against eight cancer cell lines in the MTT assay with IC50 values below 5 µM. Compounds 6a-k and 7a-n were tested for their vascular endothelial growth factor receptor-2 (VEGFR-2) kinase inhibitory activities. The p-chloro-m-trifluoromethyl diaryl urea benzyloxy derivatives 7e-i and the p-methoxydiaryl urea benzyloxy derivatives 7k, 7l, and 7n were found to be the most active compounds as VEGFR-2 inhibitors in the benzyloxy series 7, with an IC50 range of 0.09-4.15 µM. In the 2-oxo-2-phenylethoxy series 6, compounds 6e-g and 6i were reported with IC50 values of 0.94, 0.54, 2.71, and 4.81 µM, respectively. Moreover, compounds 7e and 7g induced apoptosis, causing cell cycle arrest in the G2/M phase. In addition, 7g showed an antimigratory effect in A-375 cells and inhibited the VEGFR-2 expression in an immunohistofluorescence study. Molecular docking simulations on VEGFR-2 as well as ADME properties prediction were also performed.

Convenient Diaryl Ureas as Promising Anti-pseudo-allergic Agents

Allergic diseases are a group of allergen-induced unfavorable immune responses initiating various symptoms in different organs. Mas-related G protein-coupled receptor X2 (MRGPRX2) on mast cells has been reported to be responsible for immunoglobulin E (IgE)-independent immune diseases and allergic drug reactions and has therefore been a crucial drug target for the development of anti-pseudo-allergic agents. Considering the active structural features of MRGPRX2, we designed and synthesized a series of diaryl ureas (DPUs). DPUs exert promising potency for inhibiting β-hexosaminidase release in LAD2 cells with half-maximal inhibitory concentrations (IC50) values of 2.51-0.62 μM, as well as favorable antilocal and systemic anaphylaxis in mice at a dosage of 10 mg/kg. MRGPRX2 is further revealed to participate in the anti-pseudo-allergic activity of DPUs by binding with electrophilic urea and trifluoromethyl substituents. In brief, these results highlight entities with powerful electrophilic substituents as a prospective therapeutic strategy for the treatment of IgE-independent disorders.

Diaryl Urea Derivative Molecule Inhibits Cariogenic Streptococcus mutans by Affecting Exopolysaccharide Synthesis, Stress Response, and Nitrogen Metabolism.

Different small molecules have been developed to target cariogenic bacteria Streptococcus mutans. Based on target-based designing and in silico screening, a novel diaryl urea derivative, 1,3-bis[3,5-bis(trifluoromethyl)phenyl]urea (BPU), has previously been found effective in inhibiting the growth of S. mutans. However, the exact mechanism remains unclear. This current study aimed to explore the antimicrobial and antibiofilm effects of BPU on S. mutans and locate key enzymes and biological processes affected by the molecule via in silico molecular docking analysis and transcriptomic profile. Our in vitro results confirmed that BPU was capable of inhibiting planktonic growth as well as biofilm formation of S. mutans. The virtual binding analysis predicted that the molecule had strong binding potentials with vital enzymes (3AIC and 2ZID) involved in extracellular exopolysaccharide (EPS) synthesis. The predicted inhibitive binding was further confirmed by in vitro quantification of EPS, which found a decreased amount of EPS in the biofilms. The transcriptomic profile also found differential expression of genes involved in EPS synthesis. Moreover, the transcriptomic profile implied alterations in stress response and nitrogen metabolism in S. mutans treated with BPU. Examination of differentially expressed genes involved in these biological processes revealed that altered gene expression could contribute to impaired growth, biofilm formation, and competitiveness of S. mutans. In conclusion, the novel diaryl urea derivative BPU can inhibit the virulence of S. mutans by affecting different biological processes and serves as a potent anti-caries agent.

Docking, synthesis and biological evaluation of pyridine ring containing Diaryl urea derivatives as anticancer agents

A novel series of pyridine ring containing diaryl urea derivatives (R1-R9) were synthesized in four chemical steps using pyridine-2-carboxylic acid as starting material. The synthesized compounds were design by using Autodock vina in the crystal structure of the Kinase domain of Human B-raf (PDB ID: 4DBN) to get insights into structural requirements for anticancer activity. In vitro anticancer activity against cell line (MCF-7) showed that compounds R3, R6 and R9 were found to be the most potent (Docking score: > -12, IC50 = 17.39 µM) among the synthesized molecules.

Synthesis of diaryl urea derivatives and evaluation of their antiproliferative activities in colon adenocarcinoma

Colon cancer is one of the leading causes of cancer-related deaths today. Serious research for ideal chemotherapy continues today. In this context, newly synthesized molecules have an essential role in cancer treatment research. The effects of 5 diaryl urea derivatives synthesized within the scope of this study on the HT-29 colon cancer cell line were investigated for the first time in the literature by in-silico and in-vitro methods. Among the five compounds produced in the first stage of the study, DAU5 was found to have a cytotoxic effect on HT-29. However, it was determined that it did not show a serious cytotoxic effect on L929 (healthy fibroblast cell line) at the same doses. The efficacy of DAU5 was evaluated for expression of LC3B, an indicator of autophagy, and 8-OHdG, an indicator of oxidative stress-DNA damage. LC3B and 8-OHdG expression were lower in the DAU5 treatment group than in the control group. As a result, it was seen that DAU5, a diaryl urea derivative compound we synthesized in this study, has the potential to be a chemotherapeutic agent against colon cancer. However, our study needs to be supported by in vivo and clinical studies.

Synthesis, Anticancer Evaluation and Molecular Docking Studies of Isonicotinamide and Diaryl Urea Hybrid Motifs

In search of new anticancer agents with improved efficacy, we designed and synthesized novel hybrid series of isonicotinamide and diaryl urea motifs (R1-R9). Design of series compounds carried out using docking study by Autodock vina tool. Binding energy (more than -9.7 kcal/mol) calculated using Autodock vina against Raf kinase (PDB: 4DBN). All the synthesized compounds were evaluated for them in vitro anticancer activity against MCF-7 cell line. The anticancer activities of the synthesized compounds were also carried. Some of the compounds (R1, R8, R9) showed better activities towards MCF-7 cell line by MTT assay.

Docking, Synthesis and Anticancer Activity of 4-(4-(3-(4-Chloro-3-(trifluoromethyl)- phenyl)ureido)phenoxy)-N-(2-morpholinoethyl)picolinamide Derivatives

A new series of diaryl urea derivatives bearing pyridine moiety were designed, synthesized and evaluated for their biological activity. In this study, we applied the structure-based virtual screening (SBVS) on the high similar sorafenib approved drug, selected from the DrugBank database as well as on a series of derivatives, selected from the literature. Aim was to provide new potent anticancer agents. Analysis was performed using AutoDock VINA tools. Based on the ligand binding energy. Compounds will be synthesized by chlorination of pyridine acid derivative which further coupled with amine and form amide, amide further reaction with aminophenolic moiety and form ether which is react with other aromatic amine using CDI to produce final compound and these compounds characterized by IR, NMR and mass spectroscopic techniques. The synthesized derivatives have been evaluated to their anticancer activity in vitro by MTT assay using MCF-7 cell line. The anticancer activity indicates that compounds C1, C3, C6 and C9 have better anticancer activity.

Synthesis and bioevaluation of diaryl urea derivatives as potential antitumor agents for the treatment of human colorectal cancer

The development of inhibitors targeting the PI3K-Akt-mTOR signaling pathway has been greatly hindered by the on-target AEs, such as hyperglycemia and hepatotoxicities. In this study, a series of diaryl urea derivatives has been designed and synthesized based on clinical candidate gedatolisib (6aa), and most of the newly synthesized derivatives showed kinase inhibitory and antiproliferative activities within nanomolar and submicromolar level, respectively. The terminal l-prolineamide substituted derivative 6 ab showed 8.6-fold more potent PI3Kα inhibitory activity (0.7 nM) and 4.6-fold more potent antiproliferative effect against HCT116 cell lines (0.11 μM) compared with control 6aa. The potential antitumor mechanism and efficacy of 6 ab in HCT116 xenograft models have also been evaluated, and found 6 ab showed comparable in vivo antitumor activity with 6aa. The safety investigations revealed that compound 6 ab exhibited more safer profiles in the selectivity of liver cells (selectivity index: >6.6 vs 1.85) and blood glucose regulation than 6aa. In addition, the in vitro stability assays also indicated our developed compound 6 ab possessed good metabolic stabilities.

Oxidative Stress Activated by Sorafenib Alters the Temozolomide Sensitivity of Human Glioma Cells Through Autophagy and JAK2/STAT3-AIF Axis.

The development of temozolomide (TMZ) resistance in glioma leads to poor patient prognosis. Sorafenib, a novel diaryl urea compound and multikinase inhibitor, has the ability to effectively cross the blood-brain barrier. However, the effect of sorafenib on glioma cells and the molecular mechanism underlying the ability of sorafenib to enhance the antitumor effects of TMZ remain elusive. Here, we found that sorafenib could enhance the cytotoxic effects of TMZ in glioma cells in vitro and in vivo. Mechanistically, the combination of sorafenib and TMZ induced mitochondrial depolarization and apoptosis inducing factor (AIF) translocation from mitochondria to nuclei, and this process was dependent on STAT3 inhibition. Moreover, the combination of sorafenib and TMZ inhibited JAK2/STAT3 phosphorylation and STAT3 translocation to mitochondria. Inhibition of STAT3 activation promoted the autophagy-associated apoptosis induced by the combination of sorafenib and TMZ. Furthermore, the combined sorafenib and TMZ treatment induced oxidative stress while reactive oxygen species (ROS) clearance reversed the treatment-induced inhibition of JAK2/STAT3. The results indicate that sorafenib enhanced the temozolomide sensitivity of human glioma cells by inducing oxidative stress-mediated autophagy and JAK2/STAT3-AIF axis.

Diaryl Ureas as an Antiprotozoal Chemotype.

We now describe the physicochemical profiling, in vitro ADME, and antiparasitic activity of eight N,N'-diarylureas to assess their potential as a broad-spectrum antiprotozoal chemotype. Chromatographic LogD7.4 values ranged from 2.5 to 4.5; kinetic aq. solubilities were ≤6.3 μg/mL, and plasma protein binding ranged from 95 to 99%. All of the compounds had low intrinsic clearance values in human, but not mouse, liver microsomes. Although no N,N'-diarylurea had submicromolar potency against Trypanosoma cruzi, two had submicromolar potencies against Toxoplasma gondii and Trypanosoma brucei rhodesiense, and five had submicromolar potencies against Leishmania donovani. Plasmodium falciparum appeared to be the most susceptible to growth inhibition by this compound series. Most of the N,N'-diarylureas had antiprotozoal selectivities ≥10. One N,N'-diarylurea had demonstrable activity in mouse models of malaria and toxoplasmosis.

Facile one-pot sequential synthesis of novel diaryl urea derivatives and evaluation of their in vitro cytotoxicity on adenocarcinoma cells

Recently, the diarylurea scaffold has been used widely to design potential anticancer agents. Pursuing our design strategy based on the modification of sorafenib as the lead compound using de novo design approaches, a new series of diaryl urea derivatives were synthesized through an efficient sequential one-pot reaction and evaluated for their in vitro antiproliferative activities against A549 and HT-29 cell lines. Notably, compound 11j exhibited antiproliferative activity against HT-29 with an IC50 value of 17.87 µM. SAR analyses revealed that substitution of the core diaryl scaffold with chlorine and methyl groups, and linear elongation of the molecules by the introduction of a methylene spacer group could cooperatively improve antiproliferative activity. The most active compound 11j induced mild apoptosis in HT-29 cells assessed based on DAPI staining experiments. The results of molecular docking simulations showed that the novel compounds bind to VEGFR-2 in a similar fashion to that observed for sorafenib. Molecular docking calculations also revealed that the most active compound 11j can bind well to the active site of VEGFR-2 by forming various interactions similar to those known for sorafenib particularly the π–π interaction, which is almost unique to sorafenib and highly active derivatives.

Design, synthesis and evaluation of novel thienopyrimidine-based agents bearing diaryl urea functionality as potential inhibitors of angiogenesis.

Inhibition of angiogenesis is a promising strategy for the treatment of cancer. Herein, we describe the design and synthesis of thieno[2,3-d]pyrimidine-1,3,4-thiadiazole-aryl urea derivatives 11a-m to evaluate their efficacy in the chick chorioallantoic membrane (CAM) assay. Among target agents, 11i had a considerable activity against prostate cancer cell line, PC3 (IC50=3.6μM). Moreover, induction of apoptosis, good inhibitory activity against the growth of capillary blood vessels, and inhibition of VEGFR-2 phosphorylation were noticeable parameters which convinced us that 11i could be considered as a promising candidate for the discovery of novel drugs to treat tumors, particularly prostate cancer.

Synthesis and biological evaluation of diaryl urea derivatives as FLT3 inhibitors

As a class III receptor tyrosine kinase (RTK), FMS-like tyrosine kinase 3 (FLT3) is always overexpressed in many cases of acute leukemia. This paper studies the structure-based synthesis and biological evaluation of diaryl urea derivatives as FLT3 inhibitors. Encouragingly, compounds 15b, 16b, 24a, and 24c showed excellent biological activities in a low nanomolar range. In particular, compound 16b demonstrated significant inhibitory potency against FLT3-ITD (IC50 = 5.60 nM) and better antiproliferative activity than quizartinib against MV4-11 cell line (IC50 = 0.176 nM). It is indicated that compound 16b for the treatment of acute myeloid leukemia could be very promising.

Abstract CT264: Clinical phase II study of SCO-101 - an inhibitor of SRPK1 and ABCG2 - restoring sensitivity to FOLFIRI in metastatic FOLFIRI resistant colorectal cancer patients

Abstract The purpose of the phase II study is to determine safety, tolerability, MTD and efficacy of SCO-101 in combination with FOLFIRI in patients with FOLFIRI resistant metastatic colorectal cancer. SCO-101 is a low molecular weight molecule (Acidic di-aryl urea). Preclinical studies have shown that it inhibits the SRPK1 kinase which phosphorylates and thereby activates proteins involved in the regulation of alternative splicing. It also degrades the ABCG2 drug efflux pump to which irinotecan (SN38) is a substrate. SCO-101 has successfully passed 4 clinical phase I studies in healthy volunteers and demonstrated to be a safe oral drug with very limited toxicity and good PK parameters. It reverses irinotecan- and several other types of anti-cancer drug resistance in in vitro and in vivo preclinical cancer models. The clinical phase II study: An open-label, non-randomized, prospective study, enrolling patients with acquired FOLFIRI resistant metastatic colorectal cancer. The study consists of two parts: -Part 1 is a dose escalation part based on a traditional 3+3 design. Increasing doses of SCO-101 are investigated in combination with a fixed, patient specific, dose of FOLFIRI. The primary objectives of part 1, is to determine the safety- and toxicity profile and the MTD of SCO-101. The MTD will be the recommended dose of SCO-101 for part 2 (RDP2); -Part 2 is the efficacy part, where up to 25 patients (Simons Two Stage Design) receive the SCO-101 RDP2 in combination with FOLFIRI. Primary objectives are to determine the safety- and toxicity profile and assess objective response rates. A number of potential biomarkers for SCO-101 efficacy will be evaluated. Approval for the study has been obtained and the study will start recruiting patients primo 2020. SCO-101 has two unique mechanisms of action. No other drugs have been presented that inhibits the SRPK1 kinase. Several published preclinical studies have associated high SRPK1 activity with progression of cancer including development of cancer drug resistance. SCO-101 is also the first drug described that degrades the ABCG2 drug efflux pump. If a positive signal is obtained in the clinical study, we will continue with a randomized clinical design allowing for time-dependent end-points, e.g. PFS and OS. Citation Format: Peter Michael Vestlev, Nicklas L. Roest, Jakob HV Schou, Jan Stenvang, Nils Brünner. Clinical phase II study of SCO-101 - an inhibitor of SRPK1 and ABCG2 - restoring sensitivity to FOLFIRI in metastatic FOLFIRI resistant colorectal cancer patients [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr CT264.

Comparative Target Analysis of Chlorinated Biphenyl Antimicrobials Highlights MenG as a Molecular Target of Triclocarban.

Triclocarban (TCC), a formerly used disinfectant, kills bacteria via an unknown mechanism of action. A structural hallmark is its N,N'-diaryl urea motif, which is also present in other antibiotics, including the recently reported small molecule PK150. We show here that, like PK150, TCC exhibits an inhibitory effect on Staphylococcus aureus menaquinone metabolism via inhibition of the biosynthesis protein demethylmenaquinone methyltransferase (MenG). However, the activity spectrum (MIC90) of TCC across a broad range of multidrug-resistant staphylococcus and enterococcus strains was much narrower than that of PK150. Accordingly, TCC did not cause an overactivation of signal peptidase SpsB, a hallmark of the PK150 mode of action. Furthermore, we were able to rule out inhibition of FabI, a confirmed target of the diaryl ether antibiotic triclosan (TCS). Differences in the target profiles of TCC and TCS were further investigated by proteomic analysis, showing complex but rather distinct changes in the protein expression profile of S. aureus Downregulation of the arginine deiminase pathway provided additional evidence for an effect on bacterial energy metabolism by TCC.IMPORTANCE TCC's widespread use as an antimicrobial agent has made it a ubiquitous environmental pollutant despite its withdrawal due to ecological and toxicological concerns. With its antibacterial mechanism of action still being unknown, we undertook a comparative target analysis between TCC, PK150 (a recently discovered antibacterial compound with structural resemblance to TCC), and TCS (another widely employed chlorinated biphenyl antimicrobial) in the bacterium Staphylococcus aureus We show that there are distinct differences in each compound's mode of action, but also identify a shared target between TCC and PK150, the interference with menaquinone metabolism by inhibition of MenG. The prevailing differences, however, which also manifest in a remarkably better broad-spectrum activity of PK150, suggest that even high levels of TCC or TCS resistance observed by continuous environmental exposure may not affect the potential of PK150 or related N,N'-diaryl urea compounds as new antibiotic drug candidates against multidrug-resistant infections.

Thieno[2,3-d]pyrimidin-4(3H)-one Derivatives of Benzimidazole as Potential Anti- Breast Cancer (MDA-MB-231, MCF-7) Agents.

The purpose of this study was the synthesis of some new thienopyrimidine derivatives of 1,3-disubstituted benzimidazoles and the evaluation of their cytotoxicity against MDA-MB-231, MCF-7, and 3T3 cells lines. An overexpression or mutational activation of TK receptors EGFR and HER2/neu is characteristic of tumors. It has been found that some thieno[2,3-d]pyrimidines exhibited better inhibitory activity against Epidermal Growth Factor Receptor (EGFR/ErbB-2) tyrosine kinase in comparison to aminoquinazolines. Breast cancer activity towards MDA-MB-231 and MCF-7 cell lines by inhibiting EGFR was revealed by a novel 2-arylbenzimidazole. This motivated the synthesis of new thienopyrimidines possessing benzimidazole fragments in order to evaluate their cytotoxicity to the above-mentioned cell lines. The objectives of the study were to design and synthesize a novel series of thieno[2,3-d]pyrimidines bearing biologically active moieties, such as 1,3-disubstituted-benzimidazole heterocycle, structurally similar to diaryl ureas in order to evaluate their cytotoxicity against MDA-MB-231, and MCF-7 breast cancer cell lines. N,N-disubstituted benzimidazole-2-one carbonitriles were synthesized by Aza-Michael addition and used as precursors to generate some of the new thieno[2,3-d]pyrimidines in acidic medium The interaction of chloroethyl-2-thienopyrimidines, 2-amino-benzimidazole and benzimidazol-2-one nitriles under solid-liquid transfer catalysis conditions led to new thienopyrimidines. MTT assay for cell survival was performed in order to evaluate the cytotoxicity of the tested compounds. A fluorescence study was conducted to elucidate some aspects of the mechanism of action. The effects of nine synthesized compounds were investigated towards MDA-MB-231, MCF-7 and 3T3 cell lines. Thieno[2,3-d]pyirimidine-4-one 16 (IC50 - 0.058μM) and 21 (IC50 - 0.029μM) possess high cytotoxicity against MDA-MB-231 cells after 24h. The most cytotoxic compounds against breast cancer MCF-7 cells was compound 21 (IC50 - 0.074μM), revealing lower cytotoxicity against mouse fibroblast 3T3 cells with IC50 - 0.20μM. SAR analysis was performed. Fluorescence study of the treatment of MDA-MB cells with compound 21 was carried out in order to clarify some aspects of the mechanism of action. The relationship between cytotoxicity of compounds 14 and 20 against MCF-7 and 3T3 cells can suggest a similar mechanism of action. The antitumor potential of the tested compounds proves the necessity for further investigation to estimate the exact inhibition pathway in the cellular processes. The fluorescence study of the treatment of MDA-MB cells with compound 21 showed a rapid process of apoptosis.