Structural optimization and structure-activity relationship studies of N-phenyl-7,8-dihydro-6H-pyrimido[5,4-b][1,4]oxazin-4-amine derivatives as a new class of inhibitors of RET and its drug resistance mutants.

The RET tyrosine kinase is an important therapeutic target for medullary thyroid cancer (MTC), and drug resistance mutations of RET, particularly V804M and V804L, are a main challenge for the current targeted therapy of MTC based on RET inhibitors. In this investigation, we report the structural optimization and structure-activity relationship studies of N-phenyl-7,8-dihydro-6H-pyrimido[5,4-b][1,4]oxazin-4-amine derivatives as a new class of RET inhibitors. Among all the obtained kinase inhibitors, 1-(5-(tert-butyl)isoxazol-3-yl)-3-(4-((6,7,8,9-tetrahydropyrimido[5,4-b][1,4]oxazepin-4-yl)amino)phenyl)urea (17d) is a multi-kinase inhibitor and potently inhibits RET and its drug resistance mutants. It showed IC50 (half maximal inhibitory concentration) values of 0.010 µM, 0.015 µM, and 0.009 µM against RET-wild-type, RET-V804M, and RET-V804L, respectively. 17d displayed significant anti-viability potencies against various RET-driving tumor cell lines. In a xenograft mouse model of NIH3T3-RET-C634Y, 17d exhibited potent in vivo anti-tumor activity, and no obvious toxicity was observed. Mechanisms of action were also investigated by Western blot and immunohistochemical assays. Collectively, 17d could be a promising agent for the treatment of MTC, hence deserving a further investigation.

Syntheses and cell-based phenotypic screen of novel 7-amino pyrido[2,3-d]pyrimidine-6-carbonitrile derivatives as potential antiproliferative agents.

A series of N-3-substituted 7-aminopyrido[2,3-d]pyrimidin-6-carbonitrile derivatives was readily synthesized and their anti-proliferative activities on five types of tumor cells were evaluated through a cell-based phenotypic screening approach. Compound 3k was found to be potent on human colon cancer SW620 cells with an IC(50) value of 12.5 mM. Structural optimization of compound 3k led to compound 4a with improved anti-proliferative potency on SW620 cells with an IC(50) value of 6.9 mM. Further cell-cycle analyses suggested that compound 4a induced apoptosis of SW620 cells in a concentration-dependent manner.

Synthesis and biological evaluation of 2-(3-fluoro-4-nitro phenoxy)-n-phenylacetamide derivatives as novel potential affordable antitubercular agents.

A novel series of 2-(3-fluoro-4-nitrophenoxy)-N-phenylacetamide compounds were designed, synthesized and in vitro assessed for their antitubercular activities by a microdilution method. All the novel derivatives exerted potent or moderate active against M. tuberculosis H37Rv, with MIC values ranging from 4 to 64 µg/mL. The most potent derivative 3m showed an identical MIC value of 4 µg/mL for both M. tuberculosis H37Rv and rifampin-resistant M. tuberculosis 261. It demonstrated no inhibitory effects against six different tumor cell lines by a MTT assay and had a good safety profile in a vero cell line, providing a good lead for subsequent optimization in search of novel affordable antitubercular agents.

4-(5-Oxo-5H-1,2,4-dithia-zol-3-yl)phenyl 4-methyl-benzene-sulfonate.

In the mol-ecular structure of the title compound, C(15)H(11)NO(4)S(3), the 1,2,4-dithia-zolone and central benzene rings are approximately coplanar, making a dihedral angle of 3.08 (7)°. The central benzene ring and the 4-methyl-benzene ring subtend a dihedral angle of 57.47 (8)°. In the crystal, π-π stacking occurs between the central benzene ring and the 1,2,4-dithia-zolone ring of adjacent mol-ecules, which are aligned almost parallel, the centroid-centroid distance being 3.555 (7) Å.

(Z)2-(5-(4-methoxybenzylidene)-2, 4-dioxothiazolidin-3-yl) acetic acid protects rats from CCl(4) -induced liver injury.

BACKGROUND AND AIM: (Z)2-(5-(4-methoxybenzylidene)-2, 4-dioxothiazolidin-3-yl) acetic acid (MDA) is an aldose reductase (AR) inhibitor. Recent studies suggest that AR contributes to the pathogenesis of inflammation by affecting the nuclear factor κB (NF-κB)-dependent expression of cytokines and chemokines and therefore could be a novel therapeutic target for inflammatory pathology. The current study evaluated the in vivo role of MDA in protecting the liver against injury and fibrogenesis caused by CCl(4) in rats, and the underlying mechanisms. METHODS: A single injection of CCl(4) induced acute hepatitis, and repeated injections were used to induce hepatic fibrosis in rats. Therapeutic efficacy was assessed by comparison of the severity of hepatic injury and fibrosis in MDA-treated rats versus untreated controls. RESULTS: MDA significantly protected the liver from injury by reducing the activity of serum alanine aminotransferase, and improving the histological architecture of the liver. MDA modulated NF-κB-dependent activation of inflammatory cytokines by reducing hepatic mRNA levels of tumor necrosis factor-α, interleukin-1ß, inducible nitric oxide (NO) synthase and transforming growth factor-ß. In addition, MDA attenuated oxidative stress by increasing the content of hepatic glutathione. These favorable changes were associated with suppressed hepatic NF-κB activation by MDA. MDA treatment improved liver fibrosis in rats that received repeated CCl(4) injections. In vitro, MDA attenuated phosphorylation of IκB and activation of NF-κB, and thus prevented biosynthesis of NO in lipopolysaccharide-activated RAW264.7 cells. CONCLUSIONS: The present study suggests that AR is a novel therapeutic anti-inflammatory target for the treatment of hepatitis and liver fibrosis.

3-Fluoro-4-nitro-phenyl 4-methyl-benzene-sulfonate.

In the title compound, C(13)H(10)FNO(5)S, the dihedral angle between the benzene rings is 47.63 (14)°. In the crystal, π-π stacking occurs between nearly parallel benzene rings of adjacent mol-ecules, the centroid-centroid distance being 3.7806 (16) Å. Weak inter-molecular C-H⋯O hydrogen bonding is also present in the crystal structure.

5-[(2-Chloro-4-nitro-anilino)methyl-idene]-2,2-dimethyl-1,3-dioxane-4,6-dione.

In the title compound, C(13)H(11)ClN(2)O(6), the dihedral angles between the benzene ring and the amino-methyl-ene unit and between the amino-methyl-ene group and the dioxane ring are 8.19 (14) and 1.39 (17)°, respectively. The dioxane ring has a half-boat conformation, in which the C atom between the dioxane O atoms is 0.662 (4)Å out of the plane through the remaining ring atoms. Intra-molecular N-H⋯O and N-H⋯Cl inter-actions occur.

2,2-Dimethyl-5-{[(4-nitro-phen-yl)amino]-methyl-idene}-1,3-dioxane-4,6-dione.

In the title compound, C(13)H(12)N(2)O(6), the dihedral angle between the benzene ring and the amino-methyl-ene unit is 5.42 (16)°, while the angle between the amino-methyl-ene unit and the dioxane ring is 3.06 (43)°. The dioxane ring shows a half-boat conformation, in which the C atom between the dioxane ring O atoms is 0.464 (10) Šout of the plane. An intra-molecular N-H⋯O hydrogen bond stabilizes the mol-ecular conformation. In the crystal, a three-dimensional framework is built up via inter-molecular N-H⋯O hydrogen bonds.

Development of PLGA nanoparticles simultaneously loaded with vincristine and verapamil for treatment of hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) is one of the malignant tumors with poor chemo-sensitivity to vincristine sulfate (VCR) due to multi-drug resistance (MDR). Combinations of encapsulated VCR and verapamil hydrochloride (VRP, a chemo-sensitizer) might be a potential strategy to improve HCC therapeutic efficacy of VCR. PLGA nanoparticles (PLGANPs) simultaneously loaded with VCR and VRP (CVn) were prepared. The entrapment efficiencies of VCR and VRP were 70.92 ± 3.78% and 85.78 ± 3.23%, respectively (n = 3). The HCC therapeutic activity of CVn was assessed using MTT assay. In BEL7402 and BEL7402/5-FU human hepatocarcinoma cell lines, CVn had the same antitumor effect as one free drug/another agent-loaded PLGANPs (C + Vn or Cn + V) combination and coadministration of two single-agent-loaded PLGANPs (Cn + Vn), which was slightly higher than that of the free VCR/VRP combination (C - V). CVn might cause lower normal tissue drug toxicity by the enhanced permeation and retention effect in vivo. Additionally, CVn might cause fewer drug-drug interaction and be the most potential formulation to simultaneously deliver VCR and VRP to the target cell in vivo than the other three nanoparticle formulations (C + Vn, Cn + V, and Cn + Vn). Therefore, we speculate that CVn might be the most effective preparation in the treatment of drug-resistant human HCC in vivo.

A phosphoinositide 3-kinase-gamma inhibitor, AS605240 prevents bleomycin-induced pulmonary fibrosis in rats.

Phosphoinositide 3-kinase-gamma (PI3Kgamma) has been identified to play the critical roles in inflammatory cells activation and recruitment in multiply inflammatory diseases and it promised to be a prospective target for relevant inflammatory diseases therapy. AS605240, a selective PI3Kgamma inhibitor, has been proved effective on several inflammatory diseases. In this study, we investigated the protective effect of AS605240 on bleomycin-induced pulmonary fibrosis in rats. Our results showed that orally administration of AS605240 significantly prevented lung inflammation and reduced collagen deposition. AS605240 also inhibited augmented expression of TNF-alpha and IL-1beta induced by bleomycin instillation. Moreover, the mRNA levels of TNF-alpha and IL-1beta in lung were remarkably suppressed. Histological assessment found that AS605240 reduced the expression of TGF-beta(1) and prevented T lymphocytes infiltration to lung. Phospho-Akt level in inflammatory cells by blocking PI3Kgamma was down-regulated and the inhibition of Akt phosphorylation was further confirmed by Western blot. Our findings illustrated that AS605240 was effective for preventing pulmonary fibrosis by suppressing inflammatory cells recruitment and production of inflammatory cytokines. These findings also suggest that PI3Kgamma may be a useful target in treating inflammation diseases and AS605240 may represent a promising novel agent for the future therapy of pulmonary fibrosis.

4-[4-(Piperidin-1-yl)piperidin-1-yl]benzonitrile.

In the title compound, C(17)H(23)N(3), both piperidine rings adopt chair conformations. In the crystal packing, intermolecular C-H⋯N hydrogen bonds and C-H⋯π interactions are present.

Inhibition of phosphoinositide 3-kinase ameliorates dextran sodium sulfate-induced colitis in mice.

The critical role of phosphoinositide 3-kinase gamma (PI3Kgamma) in inflammatory cell activation and recruitment makes it an attractive target for immunomodulatory therapy. 5-Quinoxilin-6-methylene-1,3-thiazolidine-2,4-dione (AS605240), a potent PI3Kgamma inhibitor, has been reported to ameliorate chronic inflammatory disorders including rheumatoid arthritis, systemic lupus erythematosus, and atherosclerosis. However, its in vivo effect on intestinal inflammation remains unknown. Here we evaluated the protective and therapeutic potentials of AS605240 in mice with dextran sodium sulfate (DSS)-induced acute and chronic colitis. Our results showed that AS605240 improved survival rate, disease activity index, and histological damage score in mice administered DSS in both preventive and therapeutic studies. AS605240 treatment also significantly inhibited the increase in myeloperoxidase levels, macrophage infiltration, and CD4(+) T-cell number in the colon of DSS-fed mice. The DSS-induced overproduction of colonic proinflammatory cytokines including interleukin (IL)-1beta, tumor necrosis factor-alpha, and interferon-gamma was significantly suppressed in mice undergoing AS605240 therapy, whereas colonic anti-inflammatory cytokines such as IL-4 were up-regulated. The down-regulation of the phospho-Akt level in immunological cells from the inflamed colon tissue and spleen of AS605240-treated mice was detected both by immunohistochemical analysis and Western blotting. These findings demonstrate that AS605240 may represent a promising novel agent for the treatment of inflammatory bowel disease by suppressing leukocyte infiltration as well as by immunoregulating the imbalance between proinflammatory and anti-inflammatory cytokines.

[SKLB-102 inhibits acute hepatitis induced by concanavalin A in mice].

OBJECTIVE: To test the effect of 5-(4-methoxybenzylidene)-2-thioxo-dihydropyrimidine-4, 6 (1H, 5H)-dione (SKLB-102) on acute hepatic inflammatory induced by concanavalin A (ConA) in mice. METHODS: The inhibitive effect of SKLB-102 on RAW264.7 cell migration induced by recombinant rat monocyte chemotactic protein-1 (MCP-1) was tested. The serum from the ConA-treated mice was collected after intragastric administration of SKLB-102 at the dose of 50 mg/kg bodyweight. The serum AST and ALT were determined by an automatic analyzer, and the serum TNF-alpha was determined with enzyme-linked immunosorbent assay (ELISA) kits. The liver samples were fixed in 10% formalin, embedded in paraffin, sectioned and then stained with hematoxylin and eosin for histological examinations. RESULTS: SKLB-102 markedly reduced cell migrations, successfully reduced serum AST, ALT and down-regulated TNF-alpha. CONCLUSION: SKLB-102 is likely to suppress the occurrence of Con A-induced hepatitis by suppressing macrophages migration and TNF-alpha releases.

Phosphoinositide 3-kinase gamma inhibitor ameliorates concanavalin A-induced hepatic injury in mice.

A pivotal role of phosphoinositide 3-kinase-gamma (PI3Kgamma) in inflammatory cell activation and recruitment makes it an attractive target for immunomodulatory therapy. In present study we investigated the therapeutic efficiency of AS605240, a selective PI3Kgamma inhibitor, on hepatitis and liver fibrosis in murine models induced by concanavalin A (ConA). Orally administration of AS605240 significantly improved survival, decreased the serum levels of alanine aminotransaminase (ALT), prevented inflammatory infiltration to liver in ConA-induced hepatitis. TNF-alpha and IFN-gamma at protein levels in serum and mRNA levels in liver were markedly reduced. Downregulated phospho-Akt level of inflammatory cells infiltrating the liver by AS605240 treatment was detected by immunohistochemistry analysis in liver and further confirmed by Western blotting analysis in splenocytes. In ConA-induced chronic liver fibrosis model, accumulation of smooth-muscle actin (SMA)-expressing cells was partially inhibited by AS605240 treatment. These observations suggest that AS605240 might be of therapeutic value for the treatment of ConA-induced hepatic injury.

5-(4-Chloro-anilinomethyl-ene)-2,2-dimethyl-1,3-dioxane-4,6-dione.

The title compound, C(13)H(12)ClNO(4), is approximately planar, with a dihedral angle of 8.23 (4)° between the mean plane of the amino-methyl-ene unit and the planar part of the dioxane ring. The dioxane ring has a half-boat conformation, in which the C atom between the dioxane O atoms is -0.464 (8) Šout of the plane of the other five atoms. In the mol-ecule there is an intra-molecular N-H⋯O hydrogen bond, involving the NH H atom and the adjacent dioxane carbonyl O atom. In the crystal, weak intermolecular C-H⋯O hydrogen-bonding contacts, result in the formation of sheets parallel to the ab plane.