Discovery of Nonpungent Transient Receptor Potential Vanilloid 1 (TRPV1) Agonist as Strong Topical Analgesic.

Paradoxically, some TRPV1 agonists are, at the organismal level, both nonpungent and clinically useful as topical analgesics. Here, we describe the scaled-up synthesis and characterization in mouse models of a novel, nonpungent vanilloid. Potent analgesic activity was observed in models of neuropathic pain, and the compound blocked capsaicin induced allodynia, showing dermal accumulation with little transdermal absorption. Finally, it displayed much weaker systemic toxicity compared to capsaicin and was negative in assays of genotoxicity.

Discovery of wt RET and V804M RET Inhibitors: From Hit to Lead.

Oncogenic activation of RET kinase has been found in several neoplastic diseases, like medullary thyroid carcinoma, multiple endocrine neoplasia, papillary thyroid carcinoma, and non-small-cell lung cancer. Currently approved RET inhibitors were not originally designed to be RET inhibitors, and their potency against RET kinase has not been optimized. Hence, novel compounds able to inhibit both wild-type RET (wt RET) and its mutants (e.g., V804M RET) are needed. Herein we present the development and the preliminary evaluation of a new sub-micromolar wt RET/V804M RET inhibitor, N-(2-fluoro-5-trifluoromethylphenyl)-N'-{4'-[(2''-benzamido)pyridin-4''-ylamino]phenyl}urea (69), endowed with a 4-anilinopyridine structure, starting from our previously identified 4-anilinopyrimidine hit compound. Profiling against a panel of kinases indicated 69 as a multi cKIT/wt RET/V804M RET inhibitor.

A novel compound T7 (N-{4'-[(1E)-N-hydroxyethanimidoyl]-3',5,6-trimethoxybiphenyl-3-yl}-N'-[4-(3-morpholin-4-ylpropoxy)phenyl]urea) screened by tissue angiogenesis model and its activity evaluation on anti-angiogenesis.

A tissue model for angiogenesis that imitated new blood vessels formation in vivo had been established in the previous study. Here, it was used to screen and evaluate a series of synthesized compounds and the results indicated that compound T7 (N-{4'-[(1E)-N-hydroxyethanimidoyl]-3',5,6-trimethoxybiphenyl-3-yl}-N'-[4-(3-morpholin-4-ylpropoxy)phenyl]urea) could effectively inhibit the blood vessels formation. Then the anti-angiogenic potential of T7 and its related molecular mechanisms against lung carcinoma in vitro and in vivo were investigated. Treatment with T7 significantly inhibited human umbilical vein endothelial cells and A549 cells proliferation and migration. T7 reduced human umbilical vein endothelial cells tube formation as well. Western blotting analysis of cell signaling molecules indicated that T7 reduced phosphorylation of KDR and its downstream signaling players AKT and ERK1/2 activation in endothelial cells and A549 cells. Moreover, T7 inhibited tumor growth in A549 xenografted model of athymic mice and reduced CD34 expression levels in tumor-bearing mice by immunohistochemistry. In sum, our findings showed that T7 was a candidate of tumor angiogenesis inhibitors, and it functioned by interrupting the autophosphorylation of KDR, AKT and ERK1/2.

Effect of BZG-4000, a novel multi-targeted kinase inhibitor with potent anticancer activity, on a hepatocellular carcinoma xenograft model.

The present study was to synthesize a novel multi-targeted kinase inhibitor and evaluated its anticancer effects on a hepatocellular carcinoma xenograft model. In our study, in vivo efficacy was determined in nude mice bearing HuH7 human HCC xenografts. The mice were randomly divided into the following five groups with the use of a randomization chart (n = 8 in each group): high-dose BZG-4000 group, medium-dose BZG-4000 group, low-dose BZG-4000 group, sorafenib group, and model group. Tumor size measurements included the length (L) and width (W) measured with calipers, and tumor volume was calculated as (LW∧2)/2. Tumor tissues slides were hematoxylin and eosin (HE) stained for histopathological examination. Immunohistochemistry detected CD31 expression, and Western blotting measured VEGF protein expression. We found that when BZG-4000 was administered orally to xenograft HuH7 nude mice, tumor growth was inhibited and significant tumor shrinkage was evident. After oral administration of BZG-4000 at 40 mg/kg/day, the tumor weight and volume were significantly lower than tumors of the sorafenib group. BZG-4000 considerably decreased the expression of CD31 and VEGF in tumors compared to tumors treated with positive control drug. It was concluded that BZG-4000 has the potential to inhibit the tumorigenesis of hepatocellular carcinoma in vivo by decreasing the expression of CD31 and VEGF.

The discovery of potent and selective 4-aminothienopyridines as B-Raf kinase inhibitors.

A series of novel, potent 4-aminothienopyridine B-Raf kinase inhibitors was designed and synthesized using knowledge-based design. Compounds 5f, and 6k exhibited not only excellent potency in both enzyme assay (IC(50)=5.1, 16.6 nM) and cellular assay (IC(50)=0.2, 0.2 µM), but also had an outstanding selectivity profile against other kinases.

Discovery of 1-[4-(N-benzylamino)phenyl]-3-phenylurea derivatives as non-peptidic selective SUMO-sentrin specific protease (SENP)1 inhibitors.

We developed 1-[4-(N-benzylamino)phenyl]-3-phenylurea derivative 4 (GN6958) as a non-peptidic selective SUMO-sentrin specific protease (SENP)1 protease inhibitor based on the hypoxia inducible factor (HIF)-1α inhibitor 1 (GN6767). The direct interaction of compound 1 with SENP1 protein in cells was observed by the pull-down experiments using the biotin-tagged compound 2 coated on the streptavidin affinity column. Among the various 1-[4-(N-benzylamino)phenyl]-3-phenylurea derivatives tested, compounds 3 and 4 suppressed HIF-1α accumulation in a concentration-dependent manner without affecting the expression level of tubulin protein in HeLa cells. Both compounds inhibited SENP1 protease activity in a concentration-dependent manner, and compound 4 exhibited more potent inhibition than compound 3. Compound 4 exhibited selective inhibition against SENP1 protease activity without inhibiting other protease enzyme activities in vitro.

Discovery, optimization, and pharmacological characterization of novel heteroaroylphenylureas antagonists of C-C chemokine ligand 2 function.

Through the application of TRAP (target-related affinity profiling), we identified a novel class of heteroaroylphenylureas that inhibit human CCL2-induced chemotaxis of monocytes/macrophages both in vitro and in vivo. This inhibition was concentration-dependent and selective with regard to other chemokines. The compounds, however, did not antagonize the binding of (125)I-labeled CCL2 to the CCR2 receptor nor did they block CCR2-mediated signal transduction responses such as calcium mobilization. Optimization of early leads for potency and pharmacokinetic parameters resulted in the identification of 17, a potent inhibitor of chemotaxis (IC(50) = 80 nM) with excellent oral bioavailability in rats (F = 60%). Compound 17 reduced swelling and joint destruction in two rat models of rheumatoid arthritis and delayed disease onset and produced near complete resolution of symptoms in a mouse model of multiple sclerosis.

Converting homogeneous to heterogeneous in electrophilic catalysis using monodisperse metal nanoparticles.

A continuing goal in catalysis is to unite the advantages of homogeneous and heterogeneous catalytic processes. To this end, nanoparticles represent a new frontier in heterogeneous catalysis, where this unification can also be supplemented by the ability to obtain new or divergent reactivity and selectivity. We report a novel method for applying heterogeneous catalysts to known homogeneous catalytic reactions through the design and synthesis of electrophilic platinum nanoparticles. These nanoparticles are selectively oxidized by the hypervalent iodine species PhICl(2), and catalyse a range of π-bond activation reactions previously only catalysed through homogeneous processes. Multiple experimental methods are used to unambiguously verify the heterogeneity of the catalytic process. The discovery of treatments for nanoparticles that induce the desired homogeneous catalytic activity should lead to the further development of reactions previously inaccessible in heterogeneous catalysis. Furthermore, a size and capping agent study revealed that Pt PAMAM dendrimer-capped nanoparticles demonstrate superior activity and recyclability compared with larger, polymer-capped analogues.

Discovery of N-benzyl-N'-(4-pipyridinyl)urea CCR5 antagonists as anti-HIV-1 agents (I): optimization of the amine portion.

Several series of carbamate, urea and carboxamide-based CCR5 antagonists have been discovered via optimizations at the amine portion of lead compound 2. All compounds were evaluated for their antiviral activities. Lead urea 29 showed good pharmacokinetic properties, justifying further development of this series.

Identification of N-(5-tert-butyl-isoxazol-3-yl)-N'-{4-[7-(2-morpholin-4-yl-ethoxy)imidazo[2,1-b][1,3]benzothiazol-2-yl]phenyl}urea dihydrochloride (AC220), a uniquely potent, selective, and efficacious FMS-like tyrosine kinase-3 (FLT3) inhibitor.

Treatment of AML patients with small molecule inhibitors of FLT3 kinase has been explored as a viable therapy. However, these agents are found to be less than optimal for the treatment of AML because of lack of sufficient potency or suboptimal oral pharmacokinetics (PK) or lack of adequate tolerability at efficacious doses. We have developed a series of extremely potent and highly selective FLT3 inhibitors with good oral PK properties. The first series of compounds represented by 1 (AB530) was found to be a potent and selective FLT3 kinase inhibitor with good PK properties. The aqueous solubility and oral PK properties at higher doses in rodents were found to be less than optimal for clinical development. A novel series of compounds were designed lacking the carboxamide group of 1 with an added water solubilizing group. Compound 7 (AC220) was identified from this series to be the most potent and selective FLT3 inhibitor with good pharmaceutical properties, excellent PK profile, and superior efficacy and tolerability in tumor xenograft models. Compound 7 has demonstrated a desirable safety and PK profile in humans and is currently in phase II clinical trials.

Development of N-4,6-pyrimidine-N-alkyl-N'-phenyl ureas as orally active inhibitors of lymphocyte specific tyrosine kinase.

A new class of lymphocyte specific tyrosine kinase (lck) inhibitors based on an N-4,6-pyrimidine-N-alkyl-N'-phenyl urea scaffold is described. Many of these compounds showed low-nanomolar inhibition of lck kinase activity as well as IL-2 synthesis from Jurkat cells. One of these analogs, 7i, was shown to be orally efficacious by in vivo testing in a rat adjuvant-induced arthritis study.