Linifanib--a multi-targeted receptor tyrosine kinase inhibitor and a low molecular weight gelator

Research and development of N,N'-diarylureas as anti-tumor agents

Tumor neovascularization provides abundant nutrients for the occurrence and development of tumors, and is also an important factor in tumor invasion and metastasis, which has attracted extensive attention in anti-tumor therapy. Sorafenib is a clinically approved multi-targeted anti-tumor drug that targets vascular endothelial growth factor receptor (VEGFR) and inhibits the formation of tumor angiogenesis, thereby achieving the purpose of suppressing tumor growth. Since the approval of sorafenib, N,N'-diarylureas have received extensive attention as the key pharmacophore in its chemical structure. And a series of N,N'-diarylureas were designed and synthesized to screen a new generation of anti-tumor drug candidates through chemical modification and structural optimization. Moreover, the rational design of targeted drugs is beneficial to reduce toxic side effects and drug resistance and improve the curative effect. Here, this article reviews the research progress in the design, classification, structure-activity relationship (SAR) and biological activity of N,N'-diarylureas, in order to provide some prospective routes for the development of clinically effective anti-tumor drugs.

New Carbamates and Ureas: Comparative Ability to Gel Organic Solvents

Two series of novel amphiphilic compounds were synthesized based on carbamates and ureas structures, using a modification of the synthesis methods reported by bibliography. The compounds were tested for organic solvent removal in a model wastewater. The lipophilic group of all compounds was a hexadecyl chain, while the hydrophilic substituent was changed with the same modifications in both series. The structures were confirmed by FT-IR, NMR, molecular dynamic simulation and HR-MS and their ability to gel organic solvents were compared. The SEM images showed the ureas had a greater ability to gel organic solvents than the carbamates and formed robust supramolecular networks, with surfaces of highly interwoven fibrillar spheres. The carbamates produced corrugated and smooth surfaces. The determination of the minimum gelation concentration demonstrated that a smaller quantity of the ureas (compared to the carbamates, measured as the weight percentage) was required to gel each solvent. This advantage of the ureas was attributed to their additional N-H bond, which is the only structural difference between the two types of compounds, and their structures were corroborated by molecular dynamic simulation. The formation of weak gels was demonstrated by rheological characterization, and they demonstrated to be good candidates for the removal organic solvents.

Local delivery of sunitinib and Ce6 via redox-responsive zwitterionic hydrogels effectively prevents osteosarcoma recurrence

The local delivery of sunitinib and Ce6 via redox-responsive zwitterionic hydrogels effectively induces apoptosis and prevents osteosarcoma recurrence.

Synthesis and characterization of some novel diaryl urea derivatives bearing quinoxalindione moiety

Diaryl urea derivatives have exhibited a broad spectrum of biochemical effects and pharmaceutical applications. Several diaryl urea derivatives such as sorafenib, regorafenib, linifanib, and tivozanib and lenvatinib are in clinical trial or clinical use. Therefore, development of small molecules within the diaryl urea scaffold with the ability of binding to variety of enzymes and receptors in the biological system are an interesting topic for researchers. Sorafenib as a diaryl urea derivative is a well-known anticancer agent. Corresponding to available information about biological activities of quinoxaline moieties, based on sorafenib scaffold, several structures were designed by replacement of pyridyl carboxamide group of sorafenib with quinoxalindione moiety. A total of 14 novel compounds in 7 synthetic steps were synthesized. Briefly, the amino group of p-aminophenol was first protected followed by O-arylation of 4-acetamidophenol with 5-chloro-2-nitroaniline to provide 5-(4-acetamidophenoxy)-2-nitroaniline. Reduction of the nitro group of 5-(4-acetamidophenoxy)-2-nitroaniline and cyclization of diamine N-(4-(3,4-diaminophenoxy) phenyl) acetamides with oxalic acid afforded compound N-(4-((2,3-dioxo-1,2,3,4-tetrahydroquinoxalin-6-yl)oxy)phenyl) acetamides which on deacetylation gave compounds 6-(4-aminophenoxy) quinoxaline-2,3 (1H, 4H)-diones. Then resultant compounds, 6-(4-aminophenoxy) quinoxaline-2,3 (1H, 4H)-diones were reacted by appropriate isocyanates/ carbamates to give the target compounds 1-(4-((2,3-dioxo-1,2,3,4-tetrahydroquinoxalin-6-yl)oxy)phenyl)-3-phenylureas. The structures of compounds confirmed by proton nuclear magnetic resonance (1H NMR), mass spectrum and Fourier transform infrared (FT-IR).

Rationally Developed Organic Salts of Tolfenamic Acid and Its β-Alanine Derivatives for Dual Purposes as an Anti-Inflammatory Topical Gel and Anticancer Agent

A new series of primary ammonium monocarboxylate (PAM) salts of a nonsteroidal anti-inflammatory drug (NSAID), namely, tolfenamic acid (TA), and its β-alanine derivatives were generated. Nearly 67 % of the salts in the series showed gelling abilities with various solvents, including water (biogenic solvent) and methyl salicylate (typically used for topical gel formulations). Gels were characterized by rheology, electron microscopy, and so forth. Structure-property correlations based on single-crystal and powder XRD data of several gelator and nongelator salts revealed intriguing insights. Studies (in vitro) on an aggressive human breast cancer cell line (MDA-MB-231) with the l-tyrosine methyl ester salt of TA (S7) revealed that the hydrogelator salt was more effective at killing cancer cells than the mother drug TA (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay); displayed better anti-inflammatory activity compared with that of TA (prostaglandin E₂ assay); could be internalized within the cancer cells, as revealed by fluorescence microscopy; and inhibited effectively migration of the cancer cells. Thus, the easily accessible ambidextrous gelator salt S7 can be used for two purposes: as an anti-inflammatory topical gel and as an anticancer agent.

Biological evaluation, docking and molecular dynamic simulation of some novel diaryl urea derivatives bearing quinoxalindione moiety

In this study a series of diarylurea derivatives containing quinoxalindione group were biologically evaluated for their cytotoxic activities using MTT assay against MCF-7 and HepG2 cell lines. Antibacterial activities of these compounds were also evaluated by Microplate Alamar Blue Assay (MABA) against three Gram-negative (Escherichia coli, Pseudomonas aeruginosa and Salmonella typhi), three Gram-positive (Staphylococcus aureus, Bacillus subtilis and Listeria monocitogenes) and one yeast-like fungus (Candida albicans) strain. Furthermore, molecular docking was carried out to study the binding pattern of the compounds to the active site of B-RAF kinase (PDB code: 1UWH). Molecular dynamics simulation was performed on the best ligand (16e) to investigate the ligand binding dynamics in the physiological environment. Cytotoxic evaluation revealed the most prominent cytotoxicity for 6 compounds with IC₅₀ values of 10-18 μM against two mentioned cell lines. None of the synthesized compounds showed significant antimicrobial activity. The obtained results of the molecular docking study showed that all compounds fitted in the binding site of enzyme with binding energy range of -11.22 to -12.69 kcal/mol vs sorafenib binding energy -11.74 kcal/mol as the lead compound. Molecular dynamic simulation indicated that the binding of ligand (16e) was stable in the active site of B-RAF during the simulation.

Developing a self-healing supramolecular nucleoside hydrogel

Low molecular weight gelator hydrogels provide a viable alternative to traditional polymer based drug delivery platforms, owing to their tunable stability and in most cases inherent biocompatibility. Here we report the first self-healing nucleoside hydrogel using N4-octanoyl-2'-deoxycytidine (0.5% w/v) for drug delivery. The hydrogel's cross-linked nanofibrillar structure, was characterised using oscillatory rheology and confirmed using SEM and TEM imaging. The potential of this gel for drug delivery was explored in vitro using fluorescently labelled tracers. Cell viability assays were conducted using pancreatic cell lines which tolerated the gels well; whilst no adverse effects on the viability or proliferation of cells were observed for fibroblast cell lines.

Low molecular weight gels induced differentiation of mesenchymal stem cells

Four low molecular weight gels (LMWGs) with different moduli were fabricated as scaffolds to investigate the differentiation of mesenchymal stem cells (MSCs).

Linifanib for treatment of hepatocellular carcinoma: An overview of clinical trials

Linifanib achieves the antitumor activity by inhibiting all vascular endothelial growth factor receptors and platelet-derived growth factor receptors. We aim to review the findings of clinical trials of linifanib for the treatment of hepatocellular carcinoma (HCC). Several phase I clinical trials have confirmed the safety of linifanib in patients with solid malignancy. One phase Ⅱ clinical trial has shown the clinical efficacy of linifanib alone for the treatment of HCC. Recently, a phase Ⅲ randomized controlled trial showed that, compared with sorafenib, linifanib cannot significantly improve the overall survival of HCC patients. Thus, linifanib is not recommended as the first-line therapy for advanced HCC. However, because linifanib could significantly prolong the time-to-progression and progression-free survival time and increase the objective response rate, future studies might be necessary to explore the clinical utility of linifanib as a second-line therapy for advanced HCC.