10-Alkoxy-anthracenyl-isoxazole analogs have sub-micromolar activity against a Glioblastoma multiforme cell line.

A series of 10-alkoxy-Anthryl-isoxazole-pyrrole-doubletails (RO-AIMs) were synthesized using a crown ether assisted nucleophilic aromatic substitution followed by a modified Schotten-Baumann reaction. The novel RO-AIMs described here exhibit robust growth inhibition for the human SNB19 CNS glioblastoma cell line, and biphenyl analog 8c had activity in the nanomolar regime, which represents the most efficacious compound in the AIM series to date. Computational modeling for RO-AIMs binding in a ternary complex with c-myc quadruplex DNA and its helicase DHX36 is presented which represents our current working hypothesis.

10-N-heterocylic aryl-isoxazole-amides (AIMs) have robust anti-tumor activity against breast and brain cancer cell lines and useful fluorescence properties.

A novel series of anthracenyl-isoxazole amide (AIM) antitumor agents containing N-heterocycles in the 10 position (N-het) were synthesized using palladium cross-coupling. The unique steric environment of the N-het-AIMs required individual optimization in each case. Lanthanide mediated double activation was used to couple the dimethylamino pyrrole moiety, required for antitumor action.

Crystal structure of the major quadruplex formed in the promoter region of the human c-MYC oncogene.

The c-MYC oncogene mediates multiple tumor cell survival pathways and is dysregulated or overexpressed in the majority of human cancers. The NHE III1 region of the c-MYC promoter forms a DNA quadruplex. Stabilization of this structure with small molecules has been shown to reduce expression of c-MYC, and targeting the c-MYC quadruplex has become an emerging strategy for development of antitumor compounds.

AIMing towards improved antitumor efficacy.

Using the structure-activity relationship emerging from previous Letter, and guided by pharmacokinetic properties, new AIMs have been prepared with both improved efficacy against human glioblastoma cells and cell permeability as determined by fluorescent confocal microscopy. We present our first unambiguous evidence for telomeric G4-forming oligonucleotide anisotropy by NMR resulting from direct interaction with AIMs, which is consistent with both our G4 melting studies by CD, and our working hypothesis. Finally, we show that AIMs induce apoptosis in SNB-19 cells.

Increased NQO1 but not c-MET and survivin expression in non-small cell lung carcinoma with KRAS mutations.

Cigarette smoking is one of the most significant public health issues and the most common environmental cause of preventable cancer deaths worldwide. EGFR (Epidermal Growth Factor Receptor)-targeted therapy has been used in the treatment of LC (lung cancer), mainly caused by the carcinogens in cigarette smoke, with variable success. Presence of mutations in the KRAS (Kirsten rat sarcoma viral oncogene homolog) driver oncogene may confer worse prognosis and resistance to treatment for reasons not fully understood.

Ethyl 3-(9-chloro-10-oxo-9,10-di-hydro-anthracen-9-yl)-5-methyl-isoxazole-4-carboxyl-ate.

The asymmetric unit of the title compound, C21H16ClNO4, contains two independent mol-ecules (A and B), each adopting a conformation wherein the isoxazole ring is roughly orthogonal to the anthrone ring. The dihedral angle between the mean plane of the isoxazole (all atoms) and the mean plane of the anthrone (all atoms) is 88.48 (3)° in one mol-ecule and 89.

Benzofuran-, benzothiophene-, indazole- and benzisoxazole-quinones: excellent substrates for NAD(P)H:quinone oxidoreductase 1.

A series of heterocyclic quinones based on benzofuran, benzothiophene, indazole and benzisoxazole has been synthesized, and evaluated for their ability to function as substrates for recombinant human NAD(P)H:quinone oxidoreductase (NQO1), a two-electron reductase upregulated in tumor cells. Overall, the quinones are excellent substrates for NQO1, approaching the reduction rates observed for menadione.

Synthesis of new quinolinequinone derivatives and preliminary exploration of their cytotoxic properties.

A series of 7-amino- and 7-acetamidoquinoline-5,8-diones with aryl substituents at the 2-position were synthesized, characterized, and evaluated as potential NAD(P)H:quinone oxidoreductase (NQO1) -directed antitumor agents. The synthesis of lavendamycin analogues is illustrated. Metabolism studies demonstrated that 7-amino analogues were generally better substrates for NQO1 than 7-amido analogues, as were compounds with smaller heteroaromatic substituents at the C-2 position.

Improved synthesis of 3-aryl isoxazoles containing fused aromatic rings.

A critical comparison of methods to prepare sterically hindered 3-aryl isoxazoles containing fused aromatic rings using the nitrile oxide cycloaddition (NOC) reveal that modification of the method of Bode, Hachisu, Matsuura, and Suzuki (BHMS), utilizing either triethylamine as base or sodium enolates of the diketone, ketoester, and ketoamide dipolarophiles, respectively, was the method of choice for this transformation.

Synthesis, metabolism and in vitro cytotoxicity studies on novel lavendamycin antitumor agents.

A series of lavendamycin analogues with two, three or four substituents at the C-6, C-7 N, C-2', C-3' and C-11' positions were synthesized via short and efficient methods and evaluated as potential NAD(P)H:quinone oxidoreductase (NQO1)-directed antitumor agents. The compounds were prepared through Pictet-Spengler condensation of the desired 2-formylquinoline-5,8-diones with the required tryptophans followed by further needed transformations. Metabolism and toxicity studies demonstrated that the best substrates for NQO1 were also the most selectively toxic to NQO1-rich tumor cells compared to NQO1-deficient tumor cells.

Lavendamycin antitumor agents: structure-based design, synthesis, and NAD(P)H:quinone oxidoreductase 1 (NQO1) model validation with molecular docking and biological studies.

A 1H69 crystal structure-based in silico model of the NAD(P)H:quinone oxidoreductase 1 (NQO1) active site has been developed to facilitate NQO1-directed lavendamycin antitumor agent development. Lavendamycin analogues were designed as NQO1 substrates utilizing structure-based design criteria. Computational docking studies were performed using the model to predict NQO1 substrate specificity.

Benzimidazole- and benzothiazole-quinones: excellent substrates for NAD(P)H:quinone oxidoreductase 1.

A series of benzimidazole- and benzothiazole-quinones has been synthesized. The ability of these heterocyclic quinones to act as substrates for recombinant human NAD(P)H:quinone oxidoreductase (NQO1), a two-electron reductase upregulated in tumour cells, was determined. Overall, the quinones were excellent substrates for NQO1.

Indolequinone antitumour agents: correlation between quinone structure and rate of metabolism by recombinant human NAD(P)H:quinone oxidoreductase.

A series of indolequinones bearing a range of substituents at the (indol-2-yl)methyl position has been synthesized. The ability of these indolequinones to act as substrates for recombinant human NAD(P)H:quinone oxidoreductase (NQO1), a two-electron reductase upregulated in tumour cells, was determined, along with their toxicity to an isogenic tumour cell line pair that is differentiated as either NQO1-expressing cells (BE-NQ) or NQO1-null cells (BE-WT). Overall, the 2-substituted indolequinones were relatively poor substrates for NQO1.

Arsenic exposure in pregnant mice disrupts placental vasculogenesis and causes spontaneous abortion.

Arsenic is an abundant toxicant in ground water and soil around areas with extractive industries. Human epidemiological studies have shown that arsenic exposure is linked to developmental defects and miscarriage. The placenta is known to utilize vasculogenesis to develop its circulation.

Activation of protein kinase C and disruption of endothelial monolayer integrity by sodium arsenite--Potential mechanism in the development of atherosclerosis.

Arsenic exposure has been shown to exacerbate atherosclerosis, beginning with activation of the endothelium that lines the vessel wall. Endothelial barrier integrity is maintained by proteins of the adherens junction (AJ) such as vascular endothelial cadherin (VE-cadherin) and beta-catenin and their association with the actin cytoskeleton. In the present study, human aortic endothelial cells (HAECs) were exposed to 1, 5 and 10 microM sodium arsenite [As(III)] for 1, 6, 12 and 24 h, and the effects on endothelial barrier integrity were determined.

Manganese enhances peroxynitrite and leukotriene E4 formation in bovine aortic endothelial cells exposed to arsenic.

Long-term exposure to arsenic in drinking water has been linked to cancer and other health effects, including cardiovascular disease. Arsenic in the environment is found in combination with a range of metals that could influence its toxicity. Manganese, in particular, is a metal that is typically found in conjunction with arsenic in contaminated groundwater.

Novel lavendamycin analogues as antitumor agents: synthesis, in vitro cytotoxicity, structure-metabolism, and computational molecular modeling studies with NAD(P)H:quinone oxidoreductase 1.

Novel lavendamycin analogues with various substituents were synthesized and evaluated as potential NAD(P)H:quinone oxidoreductase (NQO1)-directed antitumor agents. Pictet-Spengler condensation of quinoline- or quninoline-5,8-dione aldehydes with tryptamine or tryptophans yielded the lavendamycins. Metabolism studies with recombinant human NQO1 revealed that addition of NH2 and CH2OH groups at the quinolinedione-7-position and indolopyridine-2'-position had the greatest positive impact on substrate specificity.

Arsenic exposure exacerbates atherosclerotic plaque formation and increases nitrotyrosine and leukotriene biosynthesis.

A correlation between arsenic and cardiovascular disease (CVD) has been established through epidemiological studies, although the mechanisms are unknown. Using a mouse model that develops atherosclerotic lesions on a normal chow diet, we have confirmed a connection between long-term arsenic intake and CVD. Our results reveal a significant increase in the degree of atherosclerotic plaque stenosis within the innominate artery of ApoE-/-/LDLr-/- mice treated with 10 ppm sodium arsenite (133 microM) in drinking water for 18 weeks compared to controls.

Novel quinolinequinone antitumor agents: structure-metabolism studies with NAD(P)H:quinone oxidoreductase (NQO1).

A series of quinolinequinones bearing various substituents has been synthesized, and the effects of substituents on the metabolism of the quinones by recombinant human NAD(P)H:quinone oxidoreductase (hNQO1) was studied. A range of quinolinequinones were selected for study, and were specifically designed to probe the effects of aryl substituents at C-2. A range of 28 quinolinequinones 2-29 was prepared using three general strategies: the palladium(0) catalyzed coupling of 2-chloroquinolines, the classical Friedländer synthesis and the double-Vilsmeier reaction of acetanilides.

Comparative study of isoflavone, quinoxaline and oxindole families of anti-angiogenic agents.

A study designed to compare the effects on VEGF-induced angiogenesis of a number of known anti-angiogenic agents together with some novel derivatives thereof was undertaken. Thus the isoflavone biochanin A 1[structure: see text], indomethacin 2[structure: see text], the 3-arylquinoxaline SU1433 and its derivatives 3-6[structure: see text], the benzoic acid derivative 7[structure: see text], the oxindoles SU5416 8[structure: see text] and SU6668 11[structure: see text], together with their simple N-benzyl derivatives 9, 10, and 12[structure: see text] were selected for study. Using an in vitro assay the compounds were evaluated for their ability to inhibit VEGF-induced angiogenesis in HUVECs, and the cytotoxicity of representative compounds was also studied in tumour cell lines using 24-h exposure.

Arsenic induces peroxynitrite generation and cyclooxygenase-2 protein expression in aortic endothelial cells: possible role in atherosclerosis.

Epidemiological evidence suggests that exposure to the metalloid arsenic constitutes a risk factor for cardiovascular disease. The purpose of this study was to determine whether arsenic could stimulate generation of factors involved in oxidative stress and inflammation, conditions associated with atherosclerosis, or coronary artery disease. We found that production of peroxynitrite, a strong oxidant formed from the coupling of nitric oxide and superoxide anion, was significantly increased in bovine aortic endothelial (BAE) cells exposed to sodium arsenite at concentrations as low as 0.

Topical delivery of 5-fluorouracil (5-FU) by 1,3-bisalkylcarbonyl-5-FU prodrugs.

The solubilities in isopropyl myristate (S(IPM)) and pH 4.0 buffer (S(AQ)) and the partition coefficients between IPM and pH 4.0 buffer (K(IPM:AQ)) have been measured for a series of 1,3-bisalkylcarbonyl-5-fluorouracil prodrugs (1,3-AC-5-FU).