Design, Synthesis and Molecular Docking of Novel Quinazolinone Hydrazide Derivatives as EGFR Inhibitors.

A series of novel quinazolinone hydrazide derivatives were designed and synthesized as EGFR inhibitors. The results indicated that most of the aimed compounds had potential anti-tumor cell proliferation and EGFR inhibitory activities. In the comprehensive analysis of all the tested compounds, the target compound 9c showed the best anti-tumor cell proliferation activity, (IC50 =1.31 µM for MCF-7, IC50 =1.89 µM for HepG2, IC50 =2.10 µM for SGC), and IC50 =0.59 µM for the EGFR inhibitory activity. Docking results showed that compound 9c could ideally insert the active site and interact with the critical amino acid residues (Val702, Lys721, Met769, Asp831) in the active site.

Recent Progress in Small-Molecule Fluorescent Probes for Detecting Mercury Ions.

Mercury is a highly toxic and non-essential element that is found in every corner of the globe. The small amount of mercury produced by various pathways eventually enters freshwater and marine ecosystems, circulating through the food chain (especially fish) and causing various environmental problems in aspects including plants, animals, and human. There are several traditional quantitative methods developed for mercury ions (II) analysis in water samples. However, due to the complexity of the detection process, high cost and strong technical expertise, it is difficult to detect mercury ions in real-time. Therefore, in recent years, a large number of researchers have developed small-molecule fluorescent probes for Hg ions detection. Fluorimetry has the advantages of convenient detection, short response time, high sensitivity and good selectivity. This review summarized the small-molecule fluorescent probes for mercuric ion detection developed in recent years according to the chemical structural classification, compared their performances and elaborated the mechanism. We hope that the review will help the researches for the designs of metal ions fluorescent probes and their applications with certain reference value.

Design, synthesis and bioactivity evaluation of thiazolidinedione derivatives as partial agonists targeting PPARγ.

Thiazolidinedione (TZD) is a novel peroxides proliferator activated receptor γ (PPARγ) agonist with many side effects. Herein, we developed a series of novel TZD analogues as partial agonists targeting PPARγ. The study of anti-hyperglycemic activity and anti-inflammatory activity enabled us to identify a novel compound, 4 g, which quickly recover the blood glucose of mice at the concentration of 100 mg/kg, and show similar anti-inflammatory activity to ibuprofen at the concentration of 20 mg/kg. The competitive binding assay confirmed direct binding of 4 g to the LBD of PPARγ with IC50 being 1790 nM, and dose-dependently increased the transcriptional activity of PPARγ. Besides, through computer-aided drug design software simulation docking, it was found that compound 4 g showed the best binding ability to target protein PPARγ. Furthermore, because of the introduction of benzene containing group at N3 position, the stability of H12 in the active pocket is reduced and the stability of H3 and ß-fold is increased, showing the characteristics of some PPARγ agonists, based on the docking model analysis. Together, these results suggest that 4 g is a promising PPARγ agonist that deserves further investigation.

Recent Progress in the Development of Small Molecule c-Met Inhibitors.

C-Met, also referred to as Hepatocyte Growth Factor Receptor (HGFR), is a heterodimeric receptor tyrosine kinase. It has been determined that c-Met gene mutations, overexpression, and amplification also occur in a variety of human tumor types, and these events are closely related to the aberrant activation of the HGF/c-Met signaling pathway. Meanwhile, high c-Met expression is closely associated with poor prognosis in cancer patients. The c-Met kinase has emerged as an attractive target for developing antitumor agents. In this review, we cover the recent advances on the small molecule c-Met inhibitors discovered from 2018 until now, with a main focus on the rational design, synthesis and structureactivity relationship analysis.

Nanoscale Metal-Organic-Frameworks Coated by Biodegradable Organosilica for pH and Redox Dual Responsive Drug Release and High-Performance Anticancer Therapy.

Responsive nanocarriers with biocompatibility and precise drug releasing capability have emerged as a prospective candidate for anticancer treatment. However, the challenges imposed by the complicated preparation process and limited loading capacities have seriously impeded the development of novel multifunctional drug delivery systems. Here, we developed a novel and dual-responsive nanocarrier based on a nanoscale ZIF-8 core and an organosilica shell containing disulfide bridges in its frameworks through a facile and efficient strategy. The prepared ZIF-8@DOX@organosilica nanoparticles (ZDOS NPs) exhibited a well-defined structure and excellent doxorubicin (DOX) loading capability (41.2%) with pH and redox dual-sensitive release properties. The degradation of the organosilica shell was observed after 12 h incubation with a 10 mM reducing agent. Confocal imaging and flow cytometry analysis further proved that the nanocarriers can efficiently enter cells and complete intracellular DOX release under the low pH and high glutathione concentrations, which resulted in an enhanced cytotoxicity of DOX for cancer cells. Meanwhile, subcellular localization experiments revealed that the ZDOS NPs entered cells mainly by endocytosis and then escaped from lysosomes into the cytosol. Moreover, in vivo assays also demonstrated that the ZDOS NPs exhibited negligible systemic toxicity and significantly enhanced anticancer efficiencies compared with free DOX. In summary, our prepared pH and redox dual-responsive nanocarriers provide a potential platform for controlled release and cancer treatment.

Discovery and development of novel rhodanine derivatives targeting enoyl-acyl carrier protein reductase.

A series of rhodanine derivatives RB1-RB23 were synthesized through a two-round screening. Their Mycobacterial tuberculosis (Mtb) InhA inhibitory activity and Mtb growth blocking capability were evaluated. The most potent hit compound RB23 indicated comparable InhA inhibiton (IC50 = 2.55 µM) with the positive control Triclosan (IC50 = 6.14 µM) and Isoniazid (IC50 = 8.29 µM). Its improved growth-blocking effect on Mtb and low toxicity were attractive for further development. The docking simulation revealed the possible binding pattern of this series and picked the key interacted residues as Ser20, Phe149, Lys165 and Thr196. The 3D-QSAR model visualized the SAR discussion and hinted new information. Modifying the surroundings near rhodanine moiety might be promising attempts in later investigations.

Design, synthesis and evaluation of novel diaryl-1,5-diazoles derivatives bearing morpholine as potent dual COX-2/5-LOX inhibitors and antitumor agents.

In this paper, 41 hybrid compounds containing diaryl-1,5-diazole and morpholine structures acting as dual COX-2/5-LOX inhibitors have been designed, synthesized and biologically evaluated. Most of them showed potent antiproliferative activities and COX-2/5-LOX inhibitory in vitro. Among them, compound A33 displayed the most potency against cancer cell lines (IC50 = 6.43-10.97 µM for F10, HeLa, A549 and MCF-7 cells), lower toxicity to non-cancer cells than celecoxib (A33: IC50 = 194.01 µM vs.celecoxib: IC50 = 97.87 µM for 293T cells), and excellent inhibitory activities on COX-2 (IC50 = 0.17 µM) and 5-LOX (IC50 = 0.68 µM). Meanwhile, the molecular modeling study was performed to position compound A33 into COX-2 and 5-LOX active sites to determine the probable binding models. Mechanistic studies demonstrated that compound A33 could block cell cycle in G2 phase and subsequently induced apoptosis of F10 cells. Furthermore, compound A33 could significantly inhibit tumor growth in F10-xenograft mouse model, and pharmacokinetic study of compound A33 indicated that it showed better stability in vivo. In general, compound A33 could be a promising candidate for cancer therapy.

FAK inhibitors in Cancer, a patent review.

INTRODUCTION: Focal adhesion kinase (FAK) is a non-receptor tyrosine kinase that localizes at sites of cell adhesion to the extracellular matrix (ECM) and mediates signalling events downstream of integrin engagement of the ECM. FAK is known to regulate cell survival, proliferation and migration. AREAS COVERED: FAK expression has also been shown to be up-regulated in many cancer types. Previous study also indicates that FAK-mediated signaling and functions are intrinsically involved in the progression of tumor aggressiveness, suggesting that FAK is a promising target for anticancer therapies. Small molecule FAK inhibitors have been developed and are being tested in clinical phase trials. EXPERT OPINION: These inhibitors have demonstrated to be effective by inducing tumor cell apoptosis in addition to reducing metastasis and angiogenesis. In this review, we give updates on the design, synthesis and structure-activity relationship analysis of small molecule FAK inhibitors discovered from 2015 until now. We also review the FAK inhibitors that are in clinical development and highlight the future prospects.

Synthesis and Biological Evaluation of Glycyrrhetic Acid Derivatives as Potential VEGFR2 Inhibitors.

Vascular endothelial growth factor receptor 2 (VEGFR2) has been proven to play a major role in the regulation of tumor angiogenesis. A series of novel glycyrrhetic acid derivatives were synthesized and evaluated for their VEGFR2 inhibitory activity as well as their antiproliferative properties against four cancer cell lines (MCF-7, HeLa, HepG2, and A549). In vitro biological evaluations against these human tumor cell lines indicate that most of the prepared compounds have antiproliferative activities; compound 3 a (3ß-hydroxy-30-(4-phenyl-1-piperazinyl)olean-12-ene-11,30-dione) exhibited the best inhibitory activity against MCF-7 cells, with an IC50 value of 1.08 µm. Compound 3 a also showed the most potent inhibitory activity against VEGFR2 tyrosine kinase, with an IC50 value of 0.35 µm. Docking simulations were performed with the aim of discovering the binding mode of compound 3 a, and the results indicate that 3 a could bind at the VEGFR2 active site.

Identification of novel 1-indolyl acetate-5-nitroimidazole derivatives of combretastatin A-4 as potential tubulin polymerization inhibitors.

Microtubules are essential for the mitotic division of cells and have become an attractive target for anti-tumour drugs due to the increased incidence of cancer and significant mitosis rate of tumour cells. In this study, a total of six indole 1-position modified 1-indolyl acetate-5-nitroimidazole derivatives were designed, synthesized, and evaluated for their ability to inhibit tubulin polymerization caused by binding to the colchicine-binding site of tubulin. Among them, compound 3 displayed the best ability to inhibit tubulin polymerization; it also exhibited better anti-proliferative activities than colchicine against a panel of human cancer cells (with IC50 values ranging from 15 to 40nM), especially HeLa cells (with IC50 values of 15nM), based on the cellular cytotoxicity assay results. Moreover, cellular mechanism studies indicated that compound 3 could induce G2/M phase arrest and apoptosis of HeLa and MCF-7 cells, which were associated with alterations in the expression of cell cycle-checkpoint related proteins (Cyclin B1, Cdc2, and P21) and a reduction in the mitochondrial membrane potential as well as alterations in the levels of apoptosis-related proteins (PARP, Caspase 9, Bcl-2, and Bax) of these cells, respectively. Importantly, in vivo studies further revealed that compound 3 could dramatically suppress HeLa cell xenograft tumour growth compared with vehicle and CA-4 phosphate (CA-4P), and no signs of toxicity were observed in these mice. Collectively, these in vitro and in vivo results indicated that compound 3 might be a promising lead compound for further development as a potential anti-cancer drug.

Tyrosyl-tRNA synthetase inhibitors: a patent review.

INTRODUCTION: Bacterial infection has been a consistent and relentless threat to human health because of emerging resistance to existing antibiotics. Therefore, much of the research has been focused on the design of new potent antibacterial agents. Tyrosyl-tRNA synthetase (TyrRS), as a member of aminoacyl-tRNA synthetase family, could recognize the information including the coincident tRNA molecules and the amino acids' structures, which are essential in translating the coded information into protein structures in nucleic acids. Therefore, the discovery and application of tyrosyl-tRNA synthetase inhibitors might be a potential strategy to control these diseases in humans. Areas covered: This review covers 1999 to 2016 wherein several new analogues were claimed as TyrRS inhibitors based on their chemical structures. Xiao, Z.P. et al patented two Chinese patents related to TyrRS inhibitors which are included. Expert opinion: Due to the pivotal role in translation, tyrosyl-tRNA synthetase has been recognized as a promising target for a new generation of antibiotics with selectivity and specificity. However, while some of the TyrRS inhibitors showed encouraging results, there is an urgent need to develop novel TyrRS inhibitors with higher activity and selectivity. Based on the published SAR results, selective tyrosyl-tRNA synthetase inhibitors could be designed and developed as the next generation of antibacterial agents.

Evaluation of Nonpeptidic Ligand Conjugates for the Treatment of Hypoxic and Carbonic Anhydrase IX-Expressing Cancers.

The majority of tumors contain regions of hypoxia, which cause marked phenotypic changes to resident cells. This altered gene expression often leads to increased resistance to anticancer treatments. Therefore, elimination of these resistant hypoxic cells is crucial to prevent disease recurrence. Herein, we describe the selective delivery of imaging and chemotherapeutic agents to cells expressing carbonic anhydrase IX (CA IX), a highly upregulated hypoxia receptor. These agents were conjugated to a potent divalent CA IX ligand through a hydrophilic PEG linker. These conjugates are shown to bind CA IX-expressing cells in a receptor-dependent manner in vitro with mid-nanomolar affinities and in vivo with good tumor selectivity. In a mouse xenograft tumor model using HT-29 cells, a cytotoxic tubulysin B conjugate completely inhibited tumor growth. Overall, the targeting of a hypoxia marker, such as CA IX, to selectively deliver imaging or chemotherapeutic agents may lead to better treatment options for solid, hypoxic tumors. In addition, the combination of standard chemotherapeutics that are most potent in normoxic dividing cells and drugs specifically designed to eliminate hypoxic nondividing cells may elicit a superior clinical outcome. Mol Cancer Ther; 16(3); 453-60. ©2016 AACR.

Recent Advances in the Design and Synthesis of c-Met Inhibitors as Anticancer Agents (2014-Present).

c-Met, also known as the surface receptor of hepatocyte growth factor receptor (HGFR), is a receptor tyrosine kinase with heterodimer transmembrane. c-Met involves in the activation of several signaling pathways, most of them are implicated in aggressive cancer phenotypes. In a variety of human malignances, c-Met/HGF signaling has been found aberrant, and in many instances, has been correlated with advanced disease stage and poor prognosis. Thus, the c-Met has identified as an emerging and interesting target for cancer chemotherapy. In this review, we briefly summarize signaling pathways of c-Met, and discuss the crystal structures of representative c-Met and the binding modes with their ligands. We also present updates on the design, synthesis and structure-activity relationship analysis of c-Met inhibitors developed from 2014 till now. At last, we review the c-Met inhibitors that are in clinical development and highlight the future prospects.

Indole-based, Antiproliferative Agents Targeting Tubulin Polymerization.

Indole is a potential lead for drug design which has been found in numerous pharmaceutically important compounds due to its medicinal properties, such as anti-tumor, anti-bacterial, anti-virus and anti-inflammatory. In the last decade, interfering with microtubule polymerization, a potential orientation to cause cell cycle arrest and apoptosis has become a promising method for cancer therapy. Thus, indole-based agents capable to modulate the microtubule assembly have gained considerable interest among scientists. This review describes the synthesis, bioactivities and SARs of indole-based agents targeting tubulin polymerization during the past decade.

Recent Developments of Metal and Metal Oxide Nanocatalysts in Organic Synthesis.

Recently, various nanomaterials have been used in many organic transformations as efficient catalysts. The development of new catalysts by nanoscale design has emerged as a fertile field for research and innovation. The ability of nanotechnology to enhance catalytic activity opens the potential to replace expensive catalysts with lower amounts of inexpensive nanocatalysts. Besides, development of efficient and environmentally friendly synthetic methodologies for the synthesis of compound libraries of medicinal scaffolds is an attractive area of research in both academic and pharmaceutical industry. According to above reports and needs, this review deals with applications of nanoparticles as catalysts in various organic syntheses. We detail the topic of organic transformations using nanoparticles: Metal Nanoparticles and Metal Oxide Nanoparticles. In the latter part, different Metal Oxide Nanoparticles, such as ZnO Nanoparticle, TiO2 Nanoparticle, and CuO Nanoparticle are discussed.

Evaluation of Nonpeptidic Ligand Conjugates for SPECT Imaging of Hypoxic and Carbonic Anhydrase IX-Expressing Cancers.

As tumors grow, vasculature is often deficient or malformed, resulting in many localized areas of hypoxia. Cells located in these hypoxic regions exhibit an altered gene expression pattern that can significantly alter resistance to conventional anticancer treatments such as ionizing radiation and chemotherapeutic drugs. A priori knowledge of the level of hypoxia within a tumor may better guide clinical care. In an effort to create a hypoxia specific imaging agent, a ligand for the tissue hypoxia marker, carbonic anhydrase IX (CA IX), was synthesized and used as a targeting ligand to deliver an attached (99m)Tc-chelating agent. Binding of the resulting conjugates to hypoxic cancer cells was first characterized in vitro. Whole animal imaging and biodistribution studies then were performed to determine tumor specificity in vivo. Several conjugates were found to bind selectively to CA IX expressing tumors in a receptor-dependent manner. We suggest that such conjugates could prove useful in identifying hypoxic cancers and/or quantitating the level of hypoxia within a tumor.

Evaluation of a Carbonic Anhydrase IX-Targeted Near-Infrared Dye for Fluorescence-Guided Surgery of Hypoxic Tumors.

Proof-of-principle studies in ovarian, lung, and brain cancer patients have shown that fluorescence-guided surgery can enable removal of otherwise undetectable malignant lesions, decrease the number of cancer-positive margins, and permit identification of disease-containing lymph nodes that would have normally evaded resection. Unfortunately, the current arsenal of tumor-targeted fluorescent dyes does not permit identification of all cancers, raising the need to design new tumor-specific fluorescent dyes to illuminate the currently undetectable cancers. In an effort to design a more universal fluorescent cancer imaging agent, we have undertaken to synthesize a fluorophore that could label all hypoxic regions of tumors. We report here the synthesis, in vitro binding, and in vivo imaging of a near-infrared (NIR) fluorescent dye that is targeted to carbonic anhydrase IX (CA IX), i.e., a widely accepted marker of hypoxic tissues. The low molecular weight NIR probe, named Hypoxyfluor, is shown to bind CA IX with high affinity and accumulate rapidly and selectively in CA IX positive tumors. Because nearly all human cancers contain hypoxic regions that express CA IX abundantly, this NIR probe should facilitate surgical resection of a wide variety of solid tumors.

Design, Synthesis, and Biological Evaluation of Potential Prodrugs Related to the Experimental Anticancer Agent Indotecan (LMP400).

Indenoisoquinoline topoisomerase I (Top1) inhibitors are a novel class of anticancer agents with two compounds in clinical trials. Recent metabolism studies of indotecan (LMP400) led to the discovery of the biologically active 2-hydroxylated analogue and 3-hydroxylated metabolite, thus providing strategically placed functional groups for the preparation of a variety of potential ester prodrugs of these two compounds. The current study details the design and synthesis of two series of indenoisoquinoline prodrugs, and it also reveals how substituents on the O-2 and O-3 positions of the A ring, which are next to the cleaved DNA strand in the drug-DNA-Top1 ternary cleavage complex, affect Top1 inhibitory activity and cytotoxicity. Many of the indenoisoquinoline prodrugs were very potent antiproliferative agents with GI50 values below 10 nM in a variety of human cancer cell lines.

Sulfonamide derivatives containing dihydropyrazole moieties selectively and potently inhibit MMP-2/MMP-9: Design, synthesis, inhibitory activity and 3D-QSAR analysis.

New series of sulfonamide derivatives containing a dihydropyrazole moieties inhibitors of MMP-2/MMP-9 were discovered using structure-based drug design. Synthesis, antitumor activity, structure-activity relationship and optimization of physicochemical properties were described. In vitro the bioassay results revealed that most target compounds showed potent inhibitory activity in the enzymatic and cellular assays. Among the compounds, compound 3i exhibited the most potent inhibitory activity with IC50 values of 0.21 µM inhibiting MMP-2 and 1.87 µM inhibiting MMP-9, comparable to the control positive compound CMT-1 (1.26 µM, 2.52 µM). Docking simulation was performed to position compound 3i into the MMP-2 active site to determine the probable binding pose. Docking simulation was further performed to position compound 3i into the MMP-2 active site to determine the probable binding model the 3D-QSAR models were built for reasonable design of MMP-2/MMP-9 inhibitors at present and in future.

Discovery of a series of novel phenylpiperazine derivatives as EGFR TK inhibitors.

Human epidermal growth factor receptor (EGFR) is an important drug target that plays a fundamental role in signal transduction pathways in oncology. We report herein the discovery of a novel class of phenylpiperazine derivatives with improved potency toward EGFR. The biological activity of compound 3p as inhibitor of EGFR was further investigated both in vitro and in vivo. Notably, compound 3p exhibited an IC50 in the nanomolar range in A549 cell cultures and induced a cessation of tumor growth with no toxicity, as determined by loss of body weight and death of treated mice. Compoutational docking studies also showed that compound 3p has interaction with EGFR key residues in the active site.