Insight into eukaryotic topoisomerase II-inhibiting fused heterocyclic compounds in human cancer cell lines by molecular docking.

Science.gov (United States)

Taskin, T; Yilmaz, S; Yildiz, I; Yalcin, I; Aki, E

2012-01-01

Etoposide is effective as an anti-tumour drug by inhibiting eukaryotic DNA topoisomerase II via establishing a covalent complex with DNA. Unfortunately, its wide therapeutic application is often hindered by multidrug resistance (MDR), low water solubility and toxicity. In our previous study, new derivatives of benzoxazoles, benzimidazoles and related fused heterocyclic compounds, which exhibited significant eukaryotic DNA topoisomerase II inhibitory activity, were synthesized and exhibited better inhibitory activity compared with the drug etoposide itself. To expose the binding interactions between the eukaryotic topoisomerase II and the active heterocyclic compounds, docking studies were performed, using the software Discovery Studio 2.1, based on the crystal structure of the Topo IIA-bound G-segment DNA (PDB ID: 2RGR). The research was conducted on a selected set of 31 fused heterocyclic compounds with variation in structure and activity. The structural analyses indicate coordinate and hydrogen bonding interactions, van der Waals interactions and hydrophobic interactions between ligands and the protein, as Topo IIA-bound G-segment DNA are responsible for the preference of inhibition and potency. Collectively, the results demonstrate that the compounds 1a, 1c, 3b, 3c, 3e and 4a are significant anti-tumour drug candidates that should be further studied.

Basic nitrogen-heterocyclic compounds in the Murchison meteorite

International Nuclear Information System (INIS)

Stoks, P.G.; Schwartz, A.W.

1982-01-01

A fragment of the Murchison (C2) carbonaceous meteorite was analyzed for basic, N-heterocyclic compounds, by dual detector capillary gas chromatography as well as capillary gas chromatography/mass spectrometry, using two columns of different polarity. In the formic acid extract 2,4,6-trimethylpyridine, quinoline, isoquinoline, 2-methylquinoline and 4-methylquinoline were positively identified. In addition, a suite of alkylpyridines and quinolines and/or isoquinolines was tentatively identified from their mass spectra. The (iso)quinolines were found to contain methyl substituents exclusively. The distribution of the pyridines observed reveals a similarity to that observed from catalytic reactions of ammonia and simple aldehydes under conditions similar to those applied in Fischer-Tropsch type reactions. (author)

Recent advances in the research of heterocyclic compounds as antitubercular agents.

Science.gov (United States)

Yan, Mi; Ma, Shutao

2012-12-01

Tuberculosis (TB) is a major health problem, with approximately one-third of the world's population infected with Mycobacterium tuberculosis, eight million people in the active disease state, and two million dying annually. Furthermore, the prevalence of TB/HIV co-infection, and the emergence of multidrug-resistant tuberculosis (MDR-TB) and extensively drug-resistant tuberculosis (XDR-TB) have further aggravated the spread of this disease and thus mortality by it. There is an urgent need for novel antitubercular agents with improved properties, such as lower toxicity, shortened duration of therapy, rapid bactericidal action, and enhanced activity against MDR strains. Fortunately, a number of new potential antitubercular candidate drugs with heterocyclic rings, which are most likely to be effective against resistant strains, have entered clinical trials in recent years. This review highlights recent advances in the research of novel heterocyclic compounds, with particular focus on their antimycobacterial activity, mechanisms of action, toxicity, and structure-activity relationships (SARs). Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Positron annihilation lifetime studies of changes in free volume on some biorelevant nitrogen heterocyclic compounds and their S-glycosylation

International Nuclear Information System (INIS)

Mahmoud, K.R.; Khodair, A.I.; Shaban, S.Y.

2015-01-01

A series of N-heterocyclic compounds was investigated by positron annihilation lifetime spectroscopy as well as Doppler broadening of annihilation radiation (DBAR) at room temperature. The results showed that the formation probability and life time of ortho-positronium in this series are structure and electron-donation character dependent, and can give more information about the structure. The DBAR provides direct information about the change of core and valance electrons as well as the number of defect types present in these compounds. - Highlights: • N-heterocyclic compounds were studied by PALS and DBAR at room temperature. • These compounds contain thiohydantoins which have wide applications as anticarcinogenic, antiviral, human immunodeficiency virus (HIV) and antimicrobial activity. • The DBAR provides direct information about the change of core and valance electrons as well as the number of defect types present in these compounds.

The tert-Amino Effect in Heterocyclic Chemistry. Synthesis of Spiro Heterocycles

Directory of Open Access Journals (Sweden)

Y. Morzherin

2005-09-01

Full Text Available The tert-amino reaction effect was examined. A new method to synthesize spiro heterocycles is presented. It was shown that the “tert-amino effect” could be applied to the formation of spiro-fused heterocycles. The formation of spiro compounds proceeds in most cases in good yields in a one-pot reaction.

Cyclometalated N-heterocyclic carbene iridium(iii) complexes with naphthalimide chromophores: a novel class of phosphorescent heteroleptic compounds.

Science.gov (United States)

Lanoë, Pierre-Henri; Chan, Jonny; Groué, Antoine; Gontard, Geoffrey; Jutand, Anny; Rager, Marie-Noelle; Armaroli, Nicola; Monti, Filippo; Barbieri, Andrea; Amouri, Hani

2018-03-06

A series of cyclometalated N-heterocyclic carbene complexes of the general formula [Ir(C^N) 2 (C^C:)] has been prepared. Two sets of compounds were designed, those where (C^C:) represents a bidentate naphthalimide-substituted imidazolylidene ligand and (C^N) = ppy (3a), F2ppy (4a), bzq (5a) and those where (C^C:) represents a naphthalimide-substituted benzimidazolylidene ligand and (C^N) = ppy (3b), F2ppy (4b), bzq (5b). The naphthalimide-imidazole and naphthalimide-benzimidazole ligands 1a,b and the related imidazolium and benzimidazolium salts 2a,b were also prepared and fully characterized. The N-heterocyclic carbene Ir(iii) complexes have been characterized by NMR spectroscopy, cyclic voltammetry and elemental analysis. Moreover, the molecular structures of one imidazolium salt and four Ir(iii) complexes were determined by single-crystal X-ray diffraction. The structures provide us with valuable information, most notably the orientation of the naphthalimide chromophore with respect to the N-heterocyclic carbene moiety. All compounds are luminescent at room temperature and in a frozen solvent at 77 K, exhibiting a broad emission band that extends beyond 700 nm. The presence of the naphthalimide moiety changes the character of the lowest excited state from 3 MLCT to 3 LC, as corroborated by DFT and TD-DFT calculations. Remarkably, replacing imidazole with a benzimidazole unit improves the quantum yields of these compounds by decreasing the k nr values which is an important feature for optimized emission performance. These studies provide valuable insights about a novel class of N-heterocyclic carbene-based luminescent complexes containing organic chromophores and affording metal complexes emitting across the red-NIR range.

On the radioprotective properties of heterocyclic nitrogenous compounds

International Nuclear Information System (INIS)

Rinaldi, R.; Bernard, Y.

1964-01-01

Continuing their study of the possible radioprotective properties of heterocyclic nitrogenous compounds, the authors study certain derivatives of imidazole and other compounds of similar structure. The results obtained showed: 1 - that the derivatives resulting from the presence in the imidazole ring of the mercapto, methyl, carbonyl, or benzyl groups are inactive: these substitutions appear to destroy the significant radioprotective activity of the imidazole, 2 - that benzimidazole, on the contrary, seems to possess highly interesting properties. The percentage of survivals obtained with mice treated with benzimidazole and exposed to lethal irradiation has encouraged the authors to undertake careful study of this substance, with a view to define optimum activity conditions, and to determine the mechanism responsible for its radioprotective action. Further on and so as to of clarify certain points that might give useful data concerning the mechanisms of action of radioprotective chemicals, in respect of each of the products the authors have studied: a - the action of these bodies on the internal temperature of mice, b - their radioprotective activity in vitro, in a solution of irradiated hemin. (authors) [fr

Nitrogen, oxygen or sulfur containing heterocyclic compounds as analgesic drugs used as modulators of the nitroxidative stress.

Science.gov (United States)

Salat, Kinga; Moniczewski, Andrzej; Librowski, Tadeusz

2013-03-01

Numerous lines of evidence suggest that heterocyclic compounds used as analgesic, anti-inflammatory and anti-migraine agents can be potent regulators of the nitroxidative stress and targeting free nitrogen and oxygen radicals is a very promising strategy for future pain management. Both classical analgesics (nonsteroidal anti-inflammatory drugs, opioid drugs) and many analgesic adjuvants, including desipramine, duloxetine, fluoxetine, paroxetine, escitalopram, phenytoin or carbamazepine and α-lipoic acid can modulate the balance between pro-oxidant and antioxidant processes in the mammalian tissues and these properties of drugs such as indomethacin, meloxicam, tenoxicam, valdecoxib or some metabolites of analgesic drugs formed by the activity of tissue peroxidases may contribute to their clinical efficacy and drug-related toxic effects, including gastrointestinal ulcers, hepatic failure, agranulocytosis, aplastic anemia, neutropenia, opiate-induced hyperalgesia and tolerance. The antioxidant capacities of novel heterocyclic compounds, including the compounds acting either by prevention of formation or catalyzed decomposition of peroxynitrite anion (ONOO-), namely the peroxynitrite decomposition catalysts or as superoxide (O2 •-)-scavengers which are the functional mimetics of superoxide dismutase (SOD) enzymes (SODm), as well as the derivatives of 6-nitro-3,4-methylenedioxyphenyl-Nacylhydrazone (LASSBio-881) or γ-butyrolactone (LPP1, BM113, BM113A, BM138 and BM138A) are also discussed as potent and promising future heterocyclic analgesics.

Comprehensive and Facile Synthesis of Some Functionalized Bis-Heterocyclic Compounds Containing a Thieno[2,3-b]thiophene Motif

Science.gov (United States)

Mabkhot, Yahia N.; Barakat, Assem; Al-Majid, Abdullah M.; Alshahrani, Saeed A.

2012-01-01

A comprehensive and facile method for the synthesis of new functionalized bis-heterocyclic compounds containing a thieno[2,3-b]thiophene motif is described. The hitherto unknown bis-pyrazolothieno[2,3-b]thiophene derivatives 2a–c, bis-pyridazin othieno[2,3-b]thiophene derivatives 4, bis-pyridinothieno[2,3-b]thiophene derivatives 6a,b, and to an analogous bis-pyridinothieno[2,3-b]thiophene nitrile derivatives 7 are obtained. Additionally, the novel bis-pyradazinonothieno[2,3-b]thiophene derivatives 9, and nicotinic acid derivatives 10, 11 are obtained via bis-dienamide 8. The structures of all newly synthesized compounds have been elucidated by 1H, 13C NMR, GCMS, and IR spectrometry. These compounds represent a new class of sulfur and Nitrogen containing heterocycles that should also be of interest as new materials. PMID:22408452

Study of physicochemical properties of zinc(II) butyrate complex compounds with some heterocyclic ligands

Czech Academy of Sciences Publication Activity Database

Szakácsová, M.; Györová, K.; Szunyogová, E.; Kovářová, Jana

2002-01-01

Roč. 96, - (2002), s. 383 ISSN 0009-2770. [Meeting of Chemical Societies /54./. 30.06.2002-04.07.2002, Brno] R&D Projects: GA AV ČR KSK4050111; GA MŠk VEGA 1/9247/02; GA MŠk VEGA 047/074 Keywords : butyrate complex compounds * heterocyclic ligands Subject RIV: CD - Macromolecular Chemistry

Simple Method of Preparation and Characterization of New Antifungal Active Biginelli Type Heterocyclic Compounds

Science.gov (United States)

Velan, A. Senthilkumara; Joseph, J.; Raman, N.

2008-01-01

A simple, efficient and cost effective method is described for the synthesis of Biginelli type heterocyclic compounds of dihydropyrimidinones analogous. They were prepared from a reaction mixture consisting of substituted benzaldehydes, thiourea and ethylacetoacetate using ammonium dihydrogenphosphate as catalyst. The procedure for the preparation of the compounds is environmentally benign and safe which is advantageous in terms of experimentation, catalyst reusability, yields of the products, shorter reaction times and preclusion of toxic solvents. The four new synthesised compounds were tested for their antifungal activity. They have good antifungal activity comparing to the standard (Fluconazole). PMID:23997611

RESEARCH REGARDING THE POTENTIAL ACTIVITY OF SOME HETEROCYCLIC COMPOUNDS ON PLANTS GROWTH AND DEVELOPMENT

Directory of Open Access Journals (Sweden)

OANA-IRINA PATRICIU

2017-06-01

Full Text Available It is well known that growth and morphogenesis of plant tissue cultures can be improved by small amounts of some organic compounds. Heterocyclic compounds such as chromanones and thiazoles derivatives, valuable because of their potential biological activities, have also been reported as pesticides, herbicides and plant-growth regulators. In the present study, different concentrations of chromanones and thiazoles derivatives were employed to evaluate their effects on plantlets growth of Ocimum basilicum L. and Echinacea purpurea L. The studied compounds were proved to be growth inhibitors at high concentrations. A growth stimulation effect was registered at low concentration.

Effects of halogenated aromatics/aliphatics and nitrogen(N)-heterocyclic aromatics on estimating the persistence of future pharmaceutical compounds using a modified QSAR model.

Science.gov (United States)

Lim, Seung Joo; Fox, Peter

2014-02-01

The effects of halogenated aromatics/aliphatics and nitrogen(N)-heterocyclic aromatics on estimating the persistence of future pharmaceutical compounds were investigated using a modified half life equation. The potential future pharmaceutical compounds investigated were approximately 2000 pharmaceutical drugs currently undergoing the United States Food and Drug Administration (US FDA) testing. EPI Suite (BIOWIN) model estimates the fates of compounds based on the biodegradability under aerobic conditions. While BIOWIN considered the biodegradability of a compound only, the half life equation used in this study was modified by biodegradability, sorption and cometabolic oxidation. It was possible that the potential future pharmaceutical compounds were more accurately estimated using the modified half life equation. The modified half life equation considered sorption and cometabolic oxidation of halogenated aromatic/aliphatics and nitrogen(N)-heterocyclic aromatics in the sub-surface, while EPI Suite (BIOWIN) did not. Halogenated aliphatics in chemicals were more persistent than halogenated aromatics in the sub-surface. In addition, in the sub-surface environment, the fates of organic chemicals were much more affected by halogenation in chemicals than by nitrogen(N)-heterocyclic aromatics. © 2013.

Synthesis, electrochemical, spectrophotometric and potentiometric studies of two azo-compounds derived from 4-amino-2-methylquinoline in ethanolic-aqueous buffered solutions

Energy Technology Data Exchange (ETDEWEB)

El-Attar, Mona A.; Ghoneim, Mohamed M. [Analytical Chemistry Research Unit, Chemistry Department, Tanta University (Egypt); Ismail, Iqbal M., E-mail: maema.2011@yahoo.com [Chemistry Department, Faculty of Science, King Abdul Aziz University, Jeddah (Saudi Arabia)

2012-08-15

Two azo-compounds, 2-methyl-4-(5-amino-2-hydroxy-phenylazo)-quinoline (2) and 2-methyl-4-(2-hydroxy-5-nitrophenylazo)-quinoline, derived from 4-amino-2-methylquinoline were synthesized. Their chemical structures were characterized and confirmed by means of elemental chemical analysis, infrared (IR) spectroscopy, {sup 1}H nuclear magnetic resonance (NMR) and mass spectrometry (MS). The electrochemical behavior of the starting compound (4-amino-2-methylquinoline) and of the two synthesized azo-derivatives was studied at the mercury electrode in the B-R universal buffer at various pH values (2-11.5) containing 40% (v/v) ethanol using dc-polarography, cyclic voltammetry and controlled-potential coulometry. Their electrode reaction pathways were elucidated and discussed. The dissociation constants (pKa) of the examined compounds, stability constants and stoichiometry of their complexes in solution with some transition metal ions (Co(II), Ni(II), Cu(II), La(III) and UO{sup 2+}{sub 2}) were determined. (author)

The Effect of Novel Heterocyclic Compounds on Cryptococcal Biofilm

Science.gov (United States)

Korem, Maya; Kagan, Sarah

2017-01-01

Biofilm formation by microorganisms depends on their communication by quorum sensing, which is mediated by small diffusible signaling molecules that accumulate in the extracellular environment. During human infection, the pathogenic yeast Cryptococcus neoformans can form biofilm on medical devices, which protects the organism and increases its resistance to antifungal agents. The aim of this study was to test two novel heterocyclic compounds, S-8 (thiazolidinedione derivative, TZD) and NA-8 (succinimide derivative, SI), for their anti-biofilm activity against strains of Cryptococcus neoformans and Cryptococcus gattii. Biofilms were formed in a defined medium in 96-well polystyrene plates and 8-well micro-slides. The effect of sub-inhibitory concentrations of S-8 and NA-8 on biofilm formation was measured after 48 h by a metabolic reduction assay and by confocal laser microscopy analysis using fluorescent staining. The formation and development of cryptococcal biofilms was inhibited significantly by these compounds in concentrations below the minimum inhibitory concentration (MIC) values. These compounds may have a potential role in preventing fungal biofilm development on indwelling medical devices or even as a therapeutic measure after the establishment of biofilm. PMID:29371559

Novel 2-phenyl-3-{4’-[N-(4”-aminophenylcarbamoyl]-phenyl}-quinazoline-4(3Hone-6-sulphonic acidbased mono azo reactive dyes

Directory of Open Access Journals (Sweden)

DIVYESH R. PATEL

2011-02-01

Full Text Available A series of new heterocyclic mono azo reactive dyes 7a–m were prepared by diazotization of 2-phenyl-3-{4’-[N-(4”-aminophenylcarbamoyl]-phenyl}-quinazoline-4(3H-one-6-sulphonic acid (3 and coupling with various cyanurated coupling components 6a–m and their dyeing performance on silk, wool and cotton fibres was assessed. These dyes were found to give a variety of colour shades with very good depth and levelness on the fibres. All the compounds were identified by conventional method (IR and 1H-NMR and elemental analyses. The percentage dye bath exhaustion on different fibres was reasonably good and acceptable. The dyed fibre showed moderate to very good fastness to light, washing and rubbing.

The investigation of hydrogens bonds between sulphur-bearing heterocyclic and proton-donor compounds by IR absorption spectra

International Nuclear Information System (INIS)

Narziev, B.N.; Nurulloev, M.; Makhkambaev, D.

1982-01-01

In this article the results of intermolecular interaction study of sulfur-containing heterocyclic (thiophene, thiophane) and proton-donar (water, alcohol, carbonic acids, chlorophon) molecules for measuring of IR spectrum absorption of protondonar compounds in soluted shape are presented

Heterocyclic Compounds: Effective α-Amylase and α-Glucosidase Inhibitors.

Science.gov (United States)

Saeedi, Mina; Hadjiakhondi, Abbas; Nabavi, Seyed Mohammad; Manayi, Azadeh

2017-01-01

Diabetes Mellitus (DM) is a metabolic disease characterized by high blood sugar levels. Recently, it has emerged as an important and global health problem with long-term complications and high economic burden. α-Amylase (α-Amy) and α-glucosidase (α-Gls) are two enzymes which are involved in the hydrolysis of starch into sugars and disaccharides leading to the increase of blood glucose level. Hence, inhibition of α-amylase and α-glucosidase plays key role in the treatment of type 2 diabetes. Heterocyclic compounds -both synthetic and naturally occurring derivatives- possess efficient biological properties. At this juncture, they have demonstrated potent inhibitory activity against α-Amy and α-Gls and were found to be versatile tools for the development of novel anti-diabetic agents.

Fused Heterocyclic Compounds as Potent Indoleamine-2,3-dioxygenase 1 Inhibitors.

Science.gov (United States)

Panda, Subhankar; Roy, Ashalata; Deka, Suman Jyoti; Trivedi, Vishal; Manna, Debasis

2016-12-08

Uncontrolled metabolism of l-tryptophan (l-Trp) in the immune system has been recognized as a critical cellular process in immune tolerance. Indoleamine 2,3-dioxygenase 1 (IDO1) enzyme plays an important role in the metabolism of a local l-Trp through the kynurenine pathway in the immune systems. In this regard, IDO1 has emerged as a therapeutic target for the treatment of diseases that are associated with immune suppression like chronic infections, cancer, and others. In this study, we synthesized a series of pyridopyrimidine, pyrazolopyranopyrimidine, and dipyrazolopyran derivatives. Further lead optimizations directed to the identification of potent compounds, 4j and 4l (IC 50 = 260 and 151 nM, respectively). These compounds also exhibited IDO1 inhibitory activities in the low nanomolar range in MDA-MB-231 cells with very low cytotoxicity. Stronger selectivity for the IDO1 enzyme (>300-fold) over tryptophan 2,3-dioxygenase (TDO) enzyme was also observed for these compounds. Hence, these fused heterocyclic compounds are attractive candidates for the advanced study of IDO1-dependent cellular function and immunotherapeutic applications.

An insight into the biological activities of heterocyclic-fatty acid hybrid molecules.

Science.gov (United States)

Venepally, Vijayendar; Reddy Jala, Ram Chandra

2017-12-01

Heterocyclic compounds are the interesting core structures for the development of new bioactive compounds. Fatty acids are derived from renewable raw materials and exhibit various biological activities. Several researchers are amalgamating these two bioactive components to yield bioactive hybrid molecules with some desirable features. Heterocyclic-fatty acid hybrid derivatives are a new class of heterocyclic compounds with a broad range of biological activities and significance in the field of medicinal chemistry. Over the last few years, many research articles emphasized the significance of heterocyclic-fatty acid hybrid derivatives. The present review article focuses the developments in designing and biological evaluation of heterocyclic-fatty acid hybrid molecules. Copyright © 2017. Published by Elsevier Masson SAS.

Acid-Base Properties of Azo Dyes in Solution Studied Using Spectrophotometry and Colorimetry

Science.gov (United States)

Snigur, D. V.; Chebotarev, A. N.; Bevziuk, K. V.

2018-03-01

Colorimetry and spectrophotometry with chemometric data processing were used to study the acid-base properties of azo dyes in aqueous solution. The capabilities of both methods were compared. Ionization constants of all the functional groups of the azo compounds studied could be determined relative to the change in the specific color difference depending on the acidity of the medium. The colorimetric functions of ion-molecular forms of azo compounds used as an analytical signal allow us to obtain complete information on the acid-base equilibrium in a wide acidity range.

Combinatorial synthesis of oxazol-thiazole bis-heterocyclic compounds.

Science.gov (United States)

Murru, Siva; Nefzi, Adel

2014-01-13

A combinatorial library of novel oxazol-thiazole bis-heterocycles was synthesized in good to excellent overall yields with high purity using a solution and solid-phase parallel synthesis approach. Oxazole amino acids, prepared from serine methyl ester and amino acids via coupling and cyclodehydration, were treated with Fmoc-NCS and α-haloketones for the parallel synthesis of diverse bis-heterocycles. Fmoc-isothiocyanate is used as a traceless reagent for thiazole formation. Oxazole diversity can be achieved by using variety of amino acids, whereas thiazole diversity is produced with various haloketones.

Dielectric Properties of Azo Polymers: Effect of the Push-Pull Azo Chromophores

Directory of Open Access Journals (Sweden)

Xuan Zhang

2018-01-01

Full Text Available The relationship between the structure and the dielectric properties of the azo polymers was studied. Four azo polymers were synthesized through the azo-coupling reaction between the same precursor (PAZ and diazonium salts of 4-aminobenzoic acid ethyl ester, 4-aminobenzonitrile, 4-nitroaniline, and 2-amino-5-nitrothiazole, respectively. The precursor and azo polymers were characterized by 1H NMR, FT-IR, UV-vis, GPC, and DSC. The dielectric constant and dielectric loss of the samples were measured in the frequency range of 100 Hz–200 kHz. Due to the existence of the azo chromophores, the dielectric constant of the azo polymers increases compared with that of the precursor. In addition, the dielectric constant of the azo polymers increases with the increase of the polarity of the azo chromophores. A random copolymer (PAZ-NT-PAZ composed of the azo polymer PAZ-NT and the precursor PAZ was also prepared to investigate the content of the azo chromophores on the dielectric properties of the azo polymers. It showed that the dielectric constant increases with the increase of the azo chromophores. The results show that the dielectric constant of this kind of azo polymers can be controlled by changing the structures and contents of azo chromophores during the preparation process.

Synthesis, characterization and anti-proliferative activity of heterocyclic hypervalent organoantimony compounds.

Science.gov (United States)

Chen, Yi; Yu, Kun; Tan, Nian-Yuan; Qiu, Ren-Hua; Liu, Wei; Luo, Ning-Lin; Tong, Le; Au, Chak-Tong; Luo, Zi-Qiang; Yin, Shuang-Feng

2014-05-22

Three heterocyclic hypervalent organoantimony chlorides RN(CH2C6H4)2SbCl (2a R = t-Bu, 2b R = Cy, 2c R = Ph) and their chalcogenide derivatives [RN(CH2C6H4)2Sb]2O (3a R = t-Bu, 3b R = Cy, 3c R = Ph) were synthesized and characterized by techniques such as (1)H NMR, (13)C NMR, X-ray diffraction, and elemental analysis. It is found that the anti-proliferative activity detected over these compounds can be attributed to the coordination bond between the antimony and nitrogen atoms of these compounds. Moreover, a preliminary study on mechanistic action suggests that the inhibition effect is ascribable to cell cycle arrest and cell apoptosis. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

AZO-Ag-AZO transparent electrode for amorphous silicon solar cells

International Nuclear Information System (INIS)

Theuring, Martin; Vehse, Martin; Maydell, Karsten von; Agert, Carsten

2014-01-01

Metal-based transparent electrodes can be fabricated at low temperatures, which is crucial for various substrate materials and solar cells. In this work, an oxide-metal-oxide (OMO) transparent electrode based on aluminum zinc oxide (AZO) and silver is compared to AZO layers, fabricated at different temperatures and indium tin oxides. With the OMO structure, a sheet resistance of 7.1/square and a transparency above 80% for almost the entire visible spectrum were achieved. The possible application of such electrodes on a textured solar cell was demonstrated on the example of a rough ZnO substrate. An OMO structure is benchmarked in a n-i-p amorphous silicon solar cell against an AZO front contact fabricated at 200 °C. In the experiment, the OMO electrode shows a superior performance with an efficiency gain of 30%. - Highlights: • Multilayer transparent electrode based on aluminum zinc oxide (AZO) and Ag • Comparison of AZO-Ag-AZO transparent electrode to AZO and indium tin oxide • Performance of AZO-Ag-AZO transparent electrodes on textured surfaces • Comparison of amorphous silicon solar cells with different transparent electrodes

Design, synthesis, antiviral activity and mode of action of phenanthrene-containing N-heterocyclic compounds inspired by the phenanthroindolizidine alkaloid antofine.

Science.gov (United States)

Yu, Xiuling; Wei, Peng; Wang, Ziwen; Liu, Yuxiu; Wang, Lizhong; Wang, Qingmin

2016-02-01

The phenanthroindolizidine alkaloid antofine and its analogues have excellent antiviral activity against tobacco mosaic virus (TMV). To simplify the structure and the synthesis of the phenanthroindolizidine alkaloid, a series of phenanthrene-containing N-heterocyclic compounds (compounds 1 to 33) were designed and synthesised, based on the intermolecular interaction of antofine and TMV RNA, and systematically evaluated for their anti-TMV activity. Most of these compounds exhibited good to reasonable anti-TMV activity. The optimum compounds 5, 12 and 21 displayed higher activity than the lead compound antofine and commercial ribavirin. Compound 12 was chosen for field trials of antiviral efficacy against TMV, and was found to exhibit better activity than control plant virus inhibitors. Compounds 5 and 12 were chosen for mode of action studies. The changes in fluorescence intensity of compounds 5 and 12 on separated TMV RNA showed that these small molecules can also bind to TMV RNA, but the mode is very different from that of antofine. The compounds combining phenanthrene and an N-heterocyclic ring could maintain the anti-TMV activity of phenanthroindolizidines, but their modes of action are different from that of antofine. The present study lays a good foundation for us to find more efficient anti-plant virus reagents. © 2015 Society of Chemical Industry.

Additive scheme for calculation of solvation enthalpies of heterocyclic aromatic compounds. Sublimation/vaporization enthalpy at 298.15 K

International Nuclear Information System (INIS)

Solomonov, Boris N.; Nagrimanov, Ruslan N.; Mukhametzyanov, Timur A.

2016-01-01

Highlights: • Additivity scheme for solvation enthalpies estimation of heteroaromatic compounds was proposed. • Method for determination of vaporization/sublimation enthalpies directly at 298.15 K was developed. • Solution enthalpies of 25 heteroaromatic compounds were measured. • Vaporization/sublimation enthalpies of 44 heteroaromatic compounds were determined. • Obtained values are in good agreement with the results of conventional methods. - Abstract: Hereby we propose a method for determination of vaporization and sublimation enthalpies of heterocyclic and carbonyl-containing aromatic compounds at 298.15 K. According to this method vaporization and sublimation enthalpies at 298.15 K are determined based on enthalpies of solvation and solution. Solvation enthalpies of heteroatomatic and carbonyl-containing compounds are calculated using an additive scheme from the solvation enthalpy of closest aromatic hydrocarbon and contributions related to the exchange of CH-groups of hydrocarbon with corresponding substituent atoms or groups. Measured solution enthalpies together with calculated solvation enthalpies allowed to calculate corresponding vaporization and sublimation enthalpies at 298.15 K for a large number of heterocyclic and carbonyl-containing compounds. We have also found that in a number of cases instead of solution enthalpy in benzene at 298.15 K fusion enthalpy at the melting temperature can be used. Comparison between literature data and calculated vaporization and sublimation enthalpies demonstrates satisfactory performance of the proposed method.

Additive scheme for calculation of solvation enthalpies of heterocyclic aromatic compounds. Sublimation/vaporization enthalpy at 298.15 K

Energy Technology Data Exchange (ETDEWEB)

Solomonov, Boris N., E-mail: boris.solomonov@kpfu.ru; Nagrimanov, Ruslan N.; Mukhametzyanov, Timur A.

2016-06-10

Highlights: • Additivity scheme for solvation enthalpies estimation of heteroaromatic compounds was proposed. • Method for determination of vaporization/sublimation enthalpies directly at 298.15 K was developed. • Solution enthalpies of 25 heteroaromatic compounds were measured. • Vaporization/sublimation enthalpies of 44 heteroaromatic compounds were determined. • Obtained values are in good agreement with the results of conventional methods. - Abstract: Hereby we propose a method for determination of vaporization and sublimation enthalpies of heterocyclic and carbonyl-containing aromatic compounds at 298.15 K. According to this method vaporization and sublimation enthalpies at 298.15 K are determined based on enthalpies of solvation and solution. Solvation enthalpies of heteroatomatic and carbonyl-containing compounds are calculated using an additive scheme from the solvation enthalpy of closest aromatic hydrocarbon and contributions related to the exchange of CH-groups of hydrocarbon with corresponding substituent atoms or groups. Measured solution enthalpies together with calculated solvation enthalpies allowed to calculate corresponding vaporization and sublimation enthalpies at 298.15 K for a large number of heterocyclic and carbonyl-containing compounds. We have also found that in a number of cases instead of solution enthalpy in benzene at 298.15 K fusion enthalpy at the melting temperature can be used. Comparison between literature data and calculated vaporization and sublimation enthalpies demonstrates satisfactory performance of the proposed method.

Synthesis of new heterocyclic compounds based on pyrazolopyridine scaffold and evaluation of their neuroprotective potential in MPP+-induced neurodegeneration.

Science.gov (United States)

Jouha, Jabrane; Loubidi, Mohammed; Bouali, Jamila; Hamri, Salha; Hafid, Abderrafia; Suzenet, Franck; Guillaumet, Gérald; Dagcı, Taner; Khouili, Mostafa; Aydın, Fadime; Saso, Luciano; Armagan, Güliz

2017-03-31

Neurodegenerative disorders including Alzheimer's disease, Parkinson's disease, and Huntington's disease affect millions of people in the world. Thus several new approaches to treat brain disorders are under development. The aim of the present study is to synthesize potential neuroprotective heterocyclic compounds based on pyrazolopyridine derivatives and then to evaluate their effects in MPP + -induced neurodegeneration in human neuroblastoma cell line (SH-SY5Y cells). The effects of the compounds on cell viability were measured by MTT assay and the changes in apoptosis-related proteins including bax, Bcl-2, Bcl-xl and caspase-3 were investigated by western blot technique. Based on the cell viability results obtained by MTT assay, the percentage of neuroprotection-induced by compounds against MPP + -induced neurotoxicity in SH-SY5Y cells was between 20% and 30% at 5 μM concentrations of all synthesized compounds. Moreover, the downregulation in pro-apoptotic proteins including bax and caspase-3 were found following the novel synthesized compounds treatments and these effects were observed in a dose-dependent manner. Our results provide an evidence that these heterocyclic compounds based on pyrazolopyridine derivatives may have a role on dopaminergic neuroprotection via antiapoptotic pathways. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Ferroelectric Nematic and Ferrielectric Smectic Mesophases in an Achiral Bent-Core Azo Compound.

Science.gov (United States)

Kumar, Jitendra; Prasad, Veena

2018-03-22

Here, we report the observation of ferroelectric nematic and ferrielectric smectic mesophases in an achiral bent-core azo compound consisting of nonsymmetrical molecules with a lateral fluoro substitution on one of the wings. These mesophases are enantiotropic in nature with fairly low transition temperatures and wide mesophase ranges. The liquid crystalline properties of this compound are investigated using polarizing optical microscope, differential scanning calorimeter, X-ray diffraction, and electro-optical studies. As revealed by X-ray diffraction measurements, the nematic mesophase is composed of skewed cybotactic clusters and, in the smectic mesophase, the molecules are tilted with respect to the layer normal. The polar order in these mesophases was confirmed by the electro-optical switching and dielectric spectroscopy measurements. The dielectric study in the nematic mesophase shows a single relaxation process at low frequency ( f interest is the fact that the smectic phase exhibits a field induced ferrielectric state, which can be exploited for designing of the potential optical devices due to multistate switching.

Recent advances in the electrochemical construction of heterocycles

Directory of Open Access Journals (Sweden)

Robert Francke

2014-12-01

Full Text Available Due to the fact that the major portion of pharmaceuticals and agrochemicals contains heterocyclic units and since the overall number of commercially used heterocyclic compounds is steadily growing, heterocyclic chemistry remains in the focus of the synthetic community. Enormous efforts have been made in the last decades in order to render the production of such compounds more selective and efficient. However, most of the conventional methods for the construction of heterocyclic cores still involve the use of strong acids or bases, the operation at elevated temperatures and/or the use of expensive catalysts and reagents. In this regard, electrosynthesis can provide a milder and more environmentally benign alternative. In fact, numerous examples for the electrochemical construction of heterocycles have been reported in recent years. These cases demonstrate that ring formation can be achieved efficiently under ambient conditions without the use of additional reagents. In order to account for the recent developments in this field, a selection of representative reactions is presented and discussed in this review.

Electrochemical methods for monitoring of environmental carcinogens.

Science.gov (United States)

Barek, J; Cvacka, J; Muck, A; Quaiserová, V; Zima, J

2001-04-01

The use of modern electroanalytical techniques, namely differential pulse polarography, differential pulse voltammetry on hanging mercury drop electrode or carbon paste electrode, adsorptive stripping voltammetry and high performance liquid chromatography with electrochemical detection for the determination of trace amounts of carcinogenic N-nitroso compounds, azo compounds, heterocyclic compounds, nitrated polycyclic aromatic hydrocarbons and aromatic and heterocyclic amines is discussed. Scope and limitations of these methods are described and some practical applications based on their combination with liquid-liquid or solid phase extraction are given.

Synthesis and antimicrobial activity of new heterocyclic compounds containing thieno[3,2-c] coumarin and pyrazolo[4,3-c] coumarin frameworks.

Science.gov (United States)

El-Dean, Adel M Kamal; Zaki, Remon M; Geies, Ahmed A; Radwan, Shaban M; Tolba, Mahmoud S

2013-01-01

Reaction of 4-chlorocoumarin-3-carbonitrile with ethyl thioglycolate and ethyl glycinate hydrochloride leads to a series of title products. Hydrazinolysis of amino thienocoumarin carboxylate afforded the hydrazine derivative which underwent various reactions to build new heterocyclic rings containing thienocoumarin moiety. Chloro acetylation of aminoester compound afforded the chloro acetyl amino which underwent nucleophilic substitution reactions various amines. The following treatment with formaldehyde under Mannich conditions afforded the corresponding imidazo derivatives. Reaction of Ghloroacetylamino with potassium thiocyanate yielded ethylpyrimidothieno coumarin sulfanylacetate which was used as a versatile precursor for synthesis of other heterocycles. On the other hand, reaction of chloro coumarin carbo nitrile with hydrazine gave the aminopyrazolocoumaine which reacted with bifunctionally compounds to give the substituted pyrimido derivatives. Diazotization and coupling of aminopyrazole with ethylcyanoacetate yielded ethylaminotriazinopyrazolocoumarine carboxylate. Several of the compounds obtained demonstrated considerable antifungal and antibacterial activity in the in vitro test systems.

The structure of active centers and the kinetic isotopic effect in the ionic polymerization of heterocyclic compounds

International Nuclear Information System (INIS)

Ponomarienko, W.A.; Berman, E.L.

1979-01-01

The method of kinetic isotopic effect has been applied to the elucidation of the structure of the active growth centres in the polymerization of some selected heterocyclic compounds. The cationic polymerization of ehtylene oxide, tetrahydrofuran and 1.3-dioxolane as well as the anionic and coordination polymerization of ethylene oxide have been discussed. (author)

Re-evaluation of azo dyes as food additives

DEFF Research Database (Denmark)

Pratt, Iona; Larsen, John Christian; Mortensen, Alicja

2013-01-01

additives to be assessed by the Scientific Committee on Food, many years ago, (ii) because of concern regarding possible health effects of artificial colours arising since the original evaluations.Concerns includedbehavioural effects in children, allergic reactions, genotoxicity and possible carcinogenicity......Aryl azo compounds are widely used as colorants (azo dyes) in a wide range of products including textiles, leather, paper, cosmetics, pharmaceuticals and food.As part of its systematic re-evaluation of food additives, the European Food Safety Authority (EFSA) has carried out new risk assessments...

Synthesis and Regioselective Reaction of Some Unsymmetrical Heterocyclic Chalcone Derivatives and Spiro Heterocyclic Compounds as Antibacterial Agents.

Science.gov (United States)

El-Hashash, Maher A; Rizk, Sameh A; Atta-Allah, Saad R

2015-12-10

A number of novel heterocyclic chalcone derivatives can be synthesized by thermal and microwave tools. Treatment of 4-(4-Acetylamino- and/or 4-bromo-phenyl)-4-oxobut-2-enoic acids with hydrogen peroxide in alkaline medium were afforded oxirane derivatives 2. Reaction of the epoxide 2 with 2-amino-5-aryl-1,3,4-thiadiazole derivatives yielded chalcone of imidazo[2,1-b]thiadiazole derivative 4 via two thermal routes. In one pot reaction of 4-bromoacetophenone, diethyloxalate, and 2-amino-5-aryl-1,3,4-thiadiazole derivatives in MW irradiation (W 250 and T 150 °C) under eco-friendly conditions afforded an unsuitable yield of the desired chalcone 4d. The chalcone derivatives 4 were used as a key starting material to synthesize some new spiroheterocyclic compounds via Michael and aza-Michael adducts. The chalcone 4f was similar to the aryl-oxo-vinylamide derivatives for the inhibition of tyrosine kinase and cancer cell growth. The electron-withdrawing substituents, such as halogens, and 2-amino-1,3,4-thiadiazole moeity decreasing the electron density, thereby decreasing the energy of HOMO, and the presence of imidazothiadiazole moiety should improve the antibacterial activity. Thus, the newly synthesized compounds were evaluated for their anti-bacterial activity against (ATCC 25923), (ATCC 10987), (ATCC 274,) and (SM514). The structure of the newly synthesized compounds was confirmed by elemental analysis and spectroscopic data.

Insight into π-hole interactions containing the inorganic heterocyclic compounds S2N2/SN2P2.

Science.gov (United States)

Lu, Bo; Zhang, Xueying; Meng, Lingpeng; Zeng, Yanli

2017-08-01

Similar to σ-hole interactions, the π-hole interaction has attracted much attention in recent years. According to the positive electrostatic potentials above and below the surface of inorganic heterocyclic compounds S 2 N 2 and three SN 2 P 2 isomers (heterocyclic compounds 1-4), and the negative electrostatic potential outside the X atom of XH 3 (X = N, P, As), S 2 N 2 /SN 2 P 2 ⋯XH 3 (X = N, P, As) complexes were constructed and optimized at the MP2/aug-cc-pVTZ level. The X atom of XH 3 (X = N, P, As) is almost perpendicular to the ring of the heterocyclic compounds. The π-hole interaction energy becomes greater as the trend goes from 1⋯XH 3 to 4⋯XH 3 . These π-hole interactions are weak and belong to "closed-shell" noncovalent interactions. According to the energy decomposition analysis, of the three attractive terms, the dispersion energy contributes more than the electrostatic energy. The polarization effect also plays an important role in the formation of π-hole complexes, with the contrasting phenomena of decreasing electronic density in the π-hole region and increasing electric density outside the X atom of XH 3 (X = N, P, As). Graphical abstract Computed density difference plots for the complexes 3⋯NH 3 (a 1 ), 3⋯PH 3 (b 1 ), 3⋯AsH 3 (c 1 ) and electron density shifts for the complexes 3⋯NH 3 (a 2 ), 3⋯PH 3 (b 2 ),3⋯AsH 3 (c 2 ) on the 0.001 a.u. contour.

Synthesis, biological evaluation and molecular modeling of a novel series of 7-azaindole based tri-heterocyclic compounds as potent CDK2/Cyclin E inhibitors.

Science.gov (United States)

Baltus, Christine B; Jorda, Radek; Marot, Christophe; Berka, Karel; Bazgier, Václav; Kryštof, Vladimír; Prié, Gildas; Viaud-Massuard, Marie-Claude

2016-01-27

From four molecules, inspired by the structural features of fascaplysin, with an interesting potential to inhibit cyclin-dependent kinases (CDKs), we designed a new series of tri-heterocyclic derivatives based on 1H-pyrrolo[2,3-b]pyridine (7-azaindole) and triazole heterocycles. Using a Huisgen type [3 + 2] cycloaddition as the convergent key step, 24 derivatives were synthesized and their biological activities were evaluated. Comparative molecular field analysis (CoMFA), based on three-dimensional quantitative structure-activity relationship (3D-QSAR) studies, was conducted on a series of 30 compounds from the literature with high to low known inhibitory activity towards CDK2/cyclin E and was validated by a test set of 5 compounds giving satisfactory predictive r(2) value of 0.92. Remarkably, it also gave a good prediction of pIC50 for our tri-heterocyclic series which reinforce the validation of this model for the pIC50 prediction of external set compounds. The most promising compound, 43, showed a micro-molar range inhibitory activity against CDK2/cyclin E and also an antiproliferative and proapoptotic activity against a panel of cancer cell lines. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

Utilization of Cyanoacetohydrazide and Oxadiazolyl Acetonitrile in the Synthesis of Some New Cytotoxic Heterocyclic Compounds.

Science.gov (United States)

Shaker, Soheir A; Marzouk, Magda I

2016-01-29

A (pyridazinyl)acetate derivative was reacted with thiosemicarbazide and hydrazine hydrate to yield spiropyridazinone and acetohydrazide derivatives, respectively. The acetohydrazide derivative was used as a starting material for synthesizing some new heterocyclic compounds such as oxoindolinylidene, dimethylpyrazolyl, methylpyrazolyl, oxopyrazolyl, cyanoacetylacetohydrazide and oxadiazolylacetonitrile derivatives. The behavior of the cyanoacetylacetohydrazide and oxadiazolylacetonitrile derivatives towards nitrogen and carbon nucleophiles was investigated. The assigned structures of the prepared compounds were elucidated by spectral methods (IR, ¹H-NMR (13)C-NMR and mass spectroscopy). Some of the newly prepared compounds were tested in vitro against a panel of four human tumor cell lines, namely hepatocellular carcinoma (liver) HePG-2, colon cancer HCT-116, human prostate cancer PC3, and mammary gland breast MCF-7. Also they were tested as antioxidants. Almost all of the tested compounds showed satisfactory activity.

Blue Chitin columns for the extraction of heterocyclic amines from urine samples

DEFF Research Database (Denmark)

Bang, J.; Frandsen, Henrik Lauritz; Skog, K.

2004-01-01

During normal cooking of meat, a class of mutagenic/carcinogenic compounds called heterocyclic amines is formed. Heterocyclic amines are rapidly absorbed and metabolised in the human body, and for estimation of the intake of heterocyclic amines, it is useful to determinate their levels in the uri...

Heterocyclic Naphthalimides as New Skeleton Structure of Compounds with Increasingly Expanding Relational Medicinal Applications.

Science.gov (United States)

Gong, Huo-Hui; Addla, Dinesh; Lv, Jing-Song; Zhou, Cheng-He

2016-01-01

Naphthalimide compounds are an important type of nitrogen-containing aromatic heterocycles with cyclic double imides and the naphthalene framework. This π-deficient large conjugated planar structure enables naphthalimide derivatives to readily interact with various biological cations, anions, small molecules and macromolecules such as DNAs, enzymes and recetors in living organism via noncovalent bonds, therefore exhibiting extensive potentiality in relatively medicinal applications. Currently, some naphthalimides as anticancer agents have entered into clinical trials and other naphthalimide-based medicinal developments as potential drugs for treatment of various diseases are actively and unprecedentedly expanding. Naphthalimide-derived artificial ion receptors, fluorescent probes and cell imaging agents are being overwhelmingly investigated and have a diversity of potential applications in real-time detecting ions and biomolecules, understanding biological processes and determining pharmacological and pharmacokinetic properties. All the above mentions have strongly implied that naphthalimide-based derivatives as new skeleton structure of compounds possess increasingly expanding relational medicinal applications, and the related research is becoming a quite attractive active topic and newly rising highlight. Combining with our research and referring other works from literature, this work systematically reviews the current research and development of heterocyclic naphthalimides as anticancer, antibacterial, antifungal, antiviral, anti-inflammatory, antidepressant agents as well as artificial cation and anion receptors, diagnostic agents and pathologic probes, and cell imaging agents for biologically important species. Some rational design strategies, structure-activity relationships and action mechanisms are discussed. The perspectives of the future development of naphthalimide-based medicinal chemistry are also presented.

(azo anils and oxalate ion) copper(ii)

African Journals Online (AJOL)

B. S. Chandravanshi

transition metal complexes compared to corresponding free ligands may be attributed to structural symmetry of ... C H, N contents in synthesized azo anils ligands and in Cu(II) complexes were found using. CHNS technique (Costech international-4100). Metal contents in synthesized complexes were. Compounds. Color.

Radioprotective properties of some heterocyclic nitrogenous compounds against changes in hemoglobin concentration and hematocrit value in x-irradiated mice

International Nuclear Information System (INIS)

Rousdhy, H.; Pierotti, T.; Polverelli, M.

1969-01-01

Radioprotective properties of imidazole and benzimidazole have been proved in previous works. In this study, authors try to demonstrate radioprotective action of these compounds in comparison with cysteamine upon the hematopoietic system after lethal X-irradiation. Results show: no drastic variations of hematologic constants (hemoglobin concentration and hematocrit value) after intraperitoneal injection of radioprotective compounds apart certain apparent reactions with the heterocyclic compounds; the better radioprotective action of benzimidazole. Twenty five days after irradiation, hemoglobin concentration and hematocrit of radio protected mice return to normal values. (author) [fr

Electrochemical oxidation of nitrogen-heterocyclic compounds at boron-doped diamond electrode.

Science.gov (United States)

Xing, Xuan; Zhu, Xiuping; Li, Hongna; Jiang, Yi; Ni, Jinren

2012-01-01

Nitrogen-heterocyclic compounds (NHCs) are toxic and bio-refractory contaminants widely spread in environment. This study investigated electrochemical degradation of NHCs at boron-doped diamond (BDD) anode with particular attention to the effect of different number and position of nitrogen atoms in molecular structure. Five classical NHCs with similar structures including indole (ID), quinoline (QL), isoquinoline (IQL), benzotriazole (BT) and benzimidazole (BM) were selected as the target compounds. Results of bulk electrolysis showed that degradation of all NHCs was fit to a pseudo first-order equation. The five compounds were degraded with the following sequence: ID>QL>IQL>BT>BM in terms of their rates of oxidation. Quantum chemical calculation was combined with experimental results to describe the degradation character of NHCs at BDD anode. A linear relationship between degradation rate and delocalization energy was observed, which demonstrated that electronic charge was redistributed through the conjugation system and accumulated at the active sites under the attack of hydroxyl radicals produced at BDD anode. Moreover, atom charge was calculated by semi empirical PM3 method and active sites of NHCs were identified respectively. Analysis of intermediates by GC-MS showed agreement with calculation results. Copyright © 2011 Elsevier Ltd. All rights reserved.

Comparative analysis of quasi-linear spectra of organic boron compounds and their heterocyclic and aromatic analogs

International Nuclear Information System (INIS)

Klimova, L.A.; Volkova, V.P.; Kugemova, M.E.; Mikhajlov, B.M.

1976-01-01

Quasiline absorption and luminescence spectra of polycyclic compounds containing boron, nitrogen, or oxygen atoms have been obtained and studied for the first time. Electron-vibrating spectra of these compounds have been compared with the corresponding spectra of nitrogen- and oxygen-containing heterocycles as well as with spectra of their aromatic analog - phenanthrene. Vibrational analysis of the spectra of all the compounds reveals, within the accuracy limit of measurements, the relative closeness of the vibrational frequencies. However, the great difference between the positions of electron transitions points to a change in π-electron structure of the molecules when heteroatoms are introduced. High sensitivity of the frequency of electron transition to structural changes makes it possible to determine the degree of influence of separate heteroatoms

Selected heterocyclic compounds as antioxidants. Synthesis and biological evaluation.

Science.gov (United States)

Tsolaki, E; Nobelos, P; Geronikaki, A; Rekka, E A

2014-01-01

Reactive oxygen species, oxidative stress, and oxidative damage are increasingly assigned important roles as harmful factors in pathological conditions and ageing. ROS are potentially reactive molecules derived from the reduction of molecular oxygen in the course of aerobic metabolism. ROS can also be produced through a variety of enzymes. Under normal circumstances, ROS concentrations are tightly controlled by physiological antioxidants. When excessively produced, or when antioxidants are depleted, ROS can impose oxidative damage to lipids, proteins, sugars and DNA. This reduction-oxidation imbalance, called oxidative stress, can subsequently contribute to the development and progression of tissue damage and play a role in the pathology of various diseases. An antioxidant is defined as "any substance that, when present at low concentrations compared with those of a substrate, significantly delays, prevents or removes oxidative damage to this target molecule". Despite evidence that oxidative damage contributes to a wide range of clinically important conditions, few antioxidants act as effective drugs in vivo. Inter alia, the difficulty of measuring antioxidant efficacy in vivo makes the interpretation of results from clinical trials difficult. A large number of synthetic compounds have been reported to possess antioxidant activity. Several of them derive from natural antioxidants, others have various structures. In this review, some of the most often reported classes of heterocyclic antioxidant compounds, as well as methods for evaluation of their antioxidant activity are discussed.

Accumulation of 19 environmental phenolic and xenobiotic heterocyclic aromatic compounds in human adipose tissue.

Science.gov (United States)

Wang, Lei; Asimakopoulos, Alexandros G; Kannan, Kurunthachalam

2015-05-01

The extensive use of environmental phenols (e.g., bisphenol A) and heterocyclic aromatic compounds (e.g., benzothiazole) in consumer products as well as widespread exposure of humans to these compounds have been well documented. Biomonitoring studies have used urinary measurements to assess exposures, based on the assumption that these chemicals are metabolized and eliminated in urine. Despite the fact that some of these chemicals are moderately lipophilic, the extent of their accumulation in adipose fat tissues has not been convincingly demonstrated. In this study, human adipose fat samples (N=20) collected from New York City, USA, were analyzed for the presence of environmental phenols, including bisphenol A (BPA), benzophenone-3 (BP-3), triclosan (TCS), and parabens, as well as heterocyclic aromatic compounds, including benzotriazole (BTR), benzothiazole (BTH), and their derivatives. BPA and TCS were frequently detected in adipose tissues at concentrations (geometric mean [GM]: 3.95ng/g wet wt for BPA and 7.21ng/g wet wt for TCS) similar to or below the values reported for human urine. High concentrations of BP-3 were found in human adipose tissues (GM: 43.4; maximum: 4940ng/g wet wt) and a positive correlation between BP-3 concentrations and donor's age was observed. The metabolite of parabens, p-hydroxybenzoic acid (p-HB), also was found at elevated levels (GM: 4160; max.: 17,400ng/g wet wt) and a positive correlation between donor's age and sum concentration of parabens and p-HB were found. The GM concentrations of BTR and BTH in human adipose tissues were below 1ng/g, although the methylated forms of BTR (i.e., TTR and XTR) and the hydrated form of BTH (i.e., 2-OH-BTH) were frequently detected in adipose samples, indicating widespread exposure to these compounds. Our results suggest that adipose tissue is an important repository for BP-3 and parabens, including p-HB, in the human body. Copyright © 2015 Elsevier Ltd. All rights reserved.

Heterocyclic N-Oxides – An Emerging Class of Therapeutic Agents

Science.gov (United States)

Mfuh, Adelphe M.; Larionov, Oleg V.

2016-01-01

Heterocyclic N-oxides have emerged as potent compounds with anticancer, antibacterial, antihypertensive, antiparasitic, anti-HIV, anti-inflammatory, herbicidal, neuroprotective, and procognitive activities. The N-oxide motif has been successfully employed in a number of recent drug development projects. This review surveys the emergence of this scaffold in the mainstream medicinal chemistry with a focus on the discovery of the heterocyclic N-oxide drugs, N-oxide-specific mechanisms of action, drug-receptor interactions and synthetic avenues to these compounds. As the first review on this subject that covers the developments since 1950s to date, it is expected that it will inspire wider implementation of the heterocyclic N-oxide motif in the rational design of new medicinal agents. PMID:26087764

Product ion distributions for the reactions of NO+ with some N-containing and O-containing heterocyclic compounds obtained using SRI-TOF-MS

Czech Academy of Sciences Publication Activity Database

Mochalski, P.; Unterkofler, K.; Španěl, Patrik; Smith, D.; Amann, A.

2015-01-01

Roč. 386, JUL 2015 (2015), s. 42-46 ISSN 1387-3806 Institutional support: RVO:61388955 Keywords : heterocyclic compounds * SRI-TOF-MS * NO+ reactions Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.183, year: 2015

Biodegradation of Various Aromatic Compounds by Enriched Bacterial Cultures: Part B--Nitrogen-, Sulfur-, and Oxygen-Containing Heterocyclic Aromatic Compounds.

Science.gov (United States)

Oberoi, Akashdeep Singh; Philip, Ligy; Bhallamudi, S Murty

2015-07-01

Present study focused on the biodegradation of various heterocyclic nitrogen, sulfur, and oxygen (NSO) compounds using naphthalene-enriched culture. Target compounds in the study were pyridine, quinoline, benzothiophene, and benzofuran. Screening studies were carried out using different microbial consortia enriched with specific polycyclic aromatic hydrocarbon (PAH) and NSO compounds. Among different microbial consortia, naphthalene-enriched culture was the most efficient consortium based on high substrate degradation rate. Substrate degradation rate with naphthalene-enriched culture followed the order pyridine > quinoline > benzofuran > benzothiophene. Benzothiophene and benzofuran were found to be highly recalcitrant pollutants. Benzothiophene could not be biodegraded when concentration was above 50 mg/l. It was observed that 2-(1H)-quinolinone, benzothiophene-2-one, and benzofuran-2,3-dione were formed as metabolic intermediates during biodegradation of quinoline, benzothiophene, and benzofuran, respectively. Quinoline-N and pyridine-N were transformed into free ammonium ions during the biodegradation process. Biodegradation pathways for various NSO compounds are proposed. Monod inhibition model was able to simulate single substrate biodegradation kinetics satisfactorily. Benzothiophene and benzofuran biodegradation kinetics, in presence of acetone, was simulated using a generalized multi-substrate model.

Multicomponent reactions: A simple and efficient route to heterocyclic phosphonates

Science.gov (United States)

2016-01-01

Summary Multicomponent reactions (MCRs) are one of the most important processes for the preparation of highly functionalized organic compounds in modern synthetic chemistry. As shown in this review, they play an important role in organophosphorus chemistry where phosphorus reagents are used as substrates for the synthesis of a wide range of phosphorylated heterocycles. In this article, an overview about multicomponent reactions used for the synthesis of heterocyclic compounds bearing a phosphonate group on the ring is given. PMID:27559377

Synthesis of novel 3-cyclohexylpropanoic acid-derived nitrogen heterocyclic compounds and their evaluation for tuberculostatic activity.

Science.gov (United States)

Gobis, Katarzyna; Foks, Henryk; Bojanowski, Krzysztof; Augustynowicz-Kopeć, Ewa; Napiórkowska, Agnieszka

2012-01-01

A series of novel 3-cyclohexylpropanoic acid derivatives and 3-cyclohexylpropanoic acid-derived nitrogen heterocyclic compounds (1-8) have been synthesized and evaluated for tuberculostatic activity. Compounds 1a, 1c, 1e and 1f bearing benzimidazole or benzimidazole-like systems showed the most potent tuberculostatic activity against Mycobacterium tuberculosis strains with MIC values ranging from 1.5 to 12.5μg/mL. More importantly 1a (6-chloro-2-(2-cyclohexylethyl)-4-nitro-1H-benzo[d]imidazole) and 1f (2-(2-cyclohexylethyl)-1H-imidazo[4,5-b]phenazine) appeared selective for M. tuberculosis as compared with eukaryotic cells (human fibroblasts), and other antimicrobial strains. These compounds may thus represent a novel, selective class of antitubercular agents. Additionally compound 1a stimulated type I collagen output by fibroblasts, in vitro. Copyright © 2011 Elsevier Ltd. All rights reserved.

Synthesis and antibacterial activity of some heterocyclic derivatives of sulfanilamide

Directory of Open Access Journals (Sweden)

B.B. Subudhi

2012-12-01

Full Text Available Considering the promising antimicrobial potential of carbonic anhydrase inhibitors and heterocyclic compounds some heterocyclic derivatives of sulfanilamide (2a-e were synthesized. The diazotisation of sulfanilamide followed by substitution with ethylacetoacetate and further condensation yielded compounds 2a-c. Schiff base of sulfanilamide with salicylaldehyde on reaction with thioglycollic acid and chloroacetyl chloride resulted in compound 2d-e. The susceptibility of Staphylococcus aureus, Enterococcus faecalis, Escherichia coli and Pseudomonas aeruginosa to the title compounds (300 μg/disc was investigated and compared to that of nitrofurantoin (300 μg/disc and ciprofloxacin (25 μg/disc. The title compounds showed good antimicrobial activity.DOI: http://dx.doi.org/10.4314/bcse.v26i3.15

Transition metal-catalyzed carbocyclization of nitrogen and oxygen-tethered 1,n-enynes and diynes: synthesis of five or six-membered heterocyclic compounds.

Science.gov (United States)

Zhang, Di-Han; Zhang, Zhen; Shi, Min

2012-10-25

Cycloisomerization of 1,n-enynes and diynes is a powerful method in organic synthesis to access heterocyclic compounds and has drawn increasing attention from organic chemists. In this paper, we attempted to summarize our recent results on the transition metal-catalyzed cycloisomerization to synthesize five or six-membered heterocyclic compounds using 1,n-enynes and diynes having a propargylic ester moiety. First, we will describe the synthesis of 2,3-disubstituted 3-pyrrolines via gold catalyzed cycloisomerization of 1,6-diynes. In addition, we will also disclose a novel silver catalyzed tandem 1,3-acyloxy migration/Mannich-type addition/elimination of the sulfonyl group of N-sulfonylhydrazone-propargylic esters to 5,6-dihydropyridazin-4-one derivatives. Furthermore, we will introduce three interesting examples of the synthesis of bicyclic compounds via titanium or rhodium catalyzed carbocyclization of enynes. In this context, we have presented that 1,n-enynes and diynes containing propargylic esters are highly reactive and useful starting materials for the cycloisomerization catalyzed by a transition metal catalyst.

Nucleobases in Space: Laboratory Studies of Polycyclic Aromatic Nitrogen Heterocycles

Science.gov (United States)

Elsila, Jamie; Mattioda, Andy; Bernstein, Max; Sandford, Scott; Hudgins, Doug

2005-01-01

Polycyclic Aromatic Nitrogen Heterocycles (PANHs) are heterocyclic aromatics Le., PAHs with carbon atoms replaced by a nitrogen atom. These molecules have been detected in meteorite extracts, and in general these nitrogen heterocycles are of astrobiological interest since this class of molecules include nucleobases, basic components of our nucleic acids. These compounds are predicted to be present in the interstellar medium and in Titan tholin, but have received relatively little attention. We will present spectra and reactions of PANHs, frozen in solid H2O at 12 K, conditions germane to astronomical observations. In contrast to simple PAHs, that do not interact strongly with solid H2O, the nitrogen atoms in PANHs are potentially capable of hydrogen bonding with H20 changing their spectra, complicating their remote detection on the surfaces of icy bodies. Moreover, we have studied the photo-chemistry of these interesting compounds under astrophysical conditions and will use our lab studies to assess a potential interstellar heritage of these compounds in carbonaceous chondrites.

Synthesis of boron-containing heterocyclic compounds

International Nuclear Information System (INIS)

Azev, Yuri; Slepukhina, Irina; Gabel, Detlef

2004-01-01

The synthesis of boron-containing 1,3,5-triazines and 1,2,4-triazines is described. Derivatives of 1,3,5-triazine containing the o-carborane cluster have been obtained by reacting the corresponding propargyl derivatives with B 10 H 14 . Derivatives of 1,2,4-triazine containing the B 12 H 12 2- cluster have been obtained by nucleophilic substitution of ethylsulfone derivatives with B 12 H 11 SH 2- . They have been isolated in their ring-protonated form. Reaction of RNH 2 -B 8 H 11 NH-R with stericly demanding heterocycles failed, either for steric or for solubility reasons

Chlorine disinfection of dye wastewater: Implications for a commercial azo dye mixture

International Nuclear Information System (INIS)

Vacchi, Francine Inforçato; Albuquerque, Anjaina Fernandes; Vendemiatti, Josiane Aparecida; Morales, Daniel Alexandre; Ormond, Alexandra B.; Freeman, Harold S.; Zocolo, Guilherme Julião; Zanoni, Maria Valnice Boldrin; Umbuzeiro, Gisela

2013-01-01

Azo dyes, the most widely used family of synthetic dyes, are often employed as colorants in areas such as textiles, plastics, foods/drugs/cosmetics, and electronics. Following their use in industrial applications, azo dyes have been found in effluents and various receiving waters. Chemical treatment of effluents containing azo dyes includes disinfection using chlorine, which can generate compounds of varying eco/genotoxicity. Among the widely known commercial azo dyes for synthetic fibers is C.I. Disperse Red 1. While this dye is known to exist as a complex mixture, reports of eco/genotoxicity involve the purified form. Bearing in mind the potential for adverse synergistic effects arising from exposures to chemical mixtures, the aim of the present study was to characterize the components of commercial Disperse Red 1 and its chlorine-mediated decoloration products and to evaluate their ecotoxicity and mutagenicity. In conducting the present study, Disperse Red 1 was treated with chlorine gas, and the solution obtained was analyzed with the aid of LC–ESI-MS/MS to identify the components present, and then evaluated for ecotoxicity and mutagenicity, using Daphnia similis and Salmonella/microsome assays, respectively. The results of this study indicated that chlorination of Disperse Red 1 produced four chlorinated aromatic compounds as the main products and that the degradation products were more ecotoxic than the parent dye. These results suggest that a disinfection process using chlorine should be avoided for effluents containing hydrophobic azo dyes such commercial Disperse Red 1. -- Highlights: ► Aqueous solutions of Disperse Red 1 were treated with chlorine. ► The chlorination products of Disperse Red 1 were identified using LC–ESI-MS/MS. ► Daphnia and Salmonella/microsome were employed for eco/genotoxicity testing. ► The chlorinated dye was more mutagenic than the dye itself. ► Chlorination should be avoided in effluents containing azo-dyes.

Synthesis, Antiproliferative, and Multidrug Resistance Reversal Activities of Heterocyclic α,β-Unsaturated Carbonyl Compounds.

Science.gov (United States)

Sun, Ju-Feng; Hou, Gui-Ge; Zhao, Feng; Cong, Wei; Li, Hong-Juan; Liu, Wen-Shuai; Wang, Chunhua

2016-10-01

A series of heterocyclic α,β-unsaturated carbonyl compounds (1a-1d, 2a-2d, 3a-3d, 4a-3d, and 5a-5d) with 1,5-diaryl-3-oxo-1,4-pentadienyl pharmacophore were synthesized for the development of anticancer and multidrug resistance reverting agents. The antiproliferative activities were tested against nine human cancer cell lines. Approximately 73% of the IC50 values were below 5 μm, while 35% of these figures were submicromolar, and compounds 3a-3d with 4-trifluoro methyl in the arylidene benzene rings were the most potent, since their IC50 values are between 0.06 and 3.09 μm against all cancer cell lines employed. Meanwhile, their multidrug resistance reversal properties and cellular uptake were further examined. The data displayed that all of these compounds could reverse multidrug resistance, particularly, compounds 3a and 4a demonstrated both potent multidrug resistance reverting properties and strong antiproliferative activities, which can be taken as leading molecules for further research of dual effect agents in tumor chemotherapy. © 2016 John Wiley & Sons A/S.

Azomesogens with a heterocyclic moiety

Indian Academy of Sciences (India)

Unknown

Azomesogens with a heterocyclic moiety. †. JAYRANG S DAVE and MEERA MENON*. Department of Applied Chemistry, Faculty of Technology and Engineering, MS University of Baroda,. Baroda 390 001, India. Abstract. Azobenzene derivatives were among the first ten liquid crystalline compounds. But there have been.

Positron annihilation lifetime studies of changes in free volume on some biorelevant nitrogen heterocyclic compounds and their S-glycosylation.

Science.gov (United States)

Mahmoud, K R; Khodair, A I; Shaban, S Y

2015-11-01

A series of N-heterocyclic compounds was investigated by positron annihilation lifetime spectroscopy as well as Doppler broadening of annihilation radiation (DBAR) at room temperature. The results showed that the formation probability and life time of ortho-positronium in this series are structure and electron-donation character dependent, and can give more information about the structure. The DBAR provides direct information about the change of core and valance electrons as well as the number of defect types present in these compounds. Copyright © 2015 Elsevier Ltd. All rights reserved.

Antibacterial and DNA cleavage activity of carbonyl functionalized N-heterocyclic carbene-silver(I) and selenium compounds

Science.gov (United States)

Haque, Rosenani A.; Iqbal, Muhammad Adnan; Mohamad, Faisal; Razali, Mohd R.

2018-03-01

The article describes syntheses and characterizations of carbonyl functionalized benzimidazolium salts, I-IV. While salts I-III are unstable at room temperature, salt IV remained stable and was further utilised to form N-heterocyclic carbene (NHC) compounds of silver(I), V and VI, and selenium compound, VII respectively. Compounds IV-VII were tested for their antibacterial potential against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). Salt IV shows a very low inhibition potential (minimum inhibitory concentration, MIC 500 μg/mL) compared to the respective silver(I)-NHC, V and VI (MIC 31.25 μg/mL against both, E. coli and S. aureus) and selenium compound, VII (MIC 125 μg/mL against E. coli and 62.50 μg/mL against S. aureus). In DNA cleavage abilities, all the test compounds cleave DNA in which the VII cleaves the DNA at the faster rate. Meanwhile, the silver(I)-NHC complexes V and VI act at the same mode and pattern of DNA cleavage while VII is similar to IV.

Fusing porphyrins with polycyclic aromatic hydrocarbons and heterocycles for optoelectronic applications

Science.gov (United States)

Thompson, Mark E.; Diev, Viacheslav; Hanson, Kenneth; Forrest, Stephen R.

2015-08-18

A compound that can be used as a donor material in organic photovoltaic devices comprising a non-activated porphyrin fused with one or more non-activated polycyclic aromatic rings or one or more non-activated heterocyclic rings can be obtained by a thermal fusion process. The compounds can include structures of Formula I: ##STR00001## By heating the reaction mixture of non-activated porphyrins with non-activated polycyclic aromatic rings or heterocyclic rings to a fusion temperature and holding for a predetermined time, fusion of one or more polycyclic rings or heterocyclic rings to the non-activated porphyrin core in meso,.beta. fashion is achieved resulting in hybrid structures containing a distorted porphyrin ring with annulated aromatic rings. The porphyrin core can be olygoporphyrins.

Effects of Electron Acceptors, Reducing Agents, and Toxic Metabolites on Anaerobic Degradation of Heterocyclic Compounds

DEFF Research Database (Denmark)

Licht, Dorthe; Ahring, Birgitte Kiær; Arvin, Erik

1996-01-01

Degradation of four heterocyclic compounds was examined under nitrate-reducing, sulphate-reducing and methanogenic conditions. Soil samples from a creosote-polluted site in Denmark were used as inoculum. Indole and quinoline were degraded under all redox conditions with the highest degradation...... of quinoline under sulphate-reducing conditions which was inhibited by sulphide at concentrations above 0.8 mM. Degradation of quinoline under methanogenic conditions was also inhibited by 3.2 mM sulphide used as a reducing agent, but sulphide had no inhibitory effect on the degradation of indole...... in methanogenic and sulphate-reducing soil slurries...

Sulfur-Kβ /sub emission studies on sulfur-bearing heterocycles

International Nuclear Information System (INIS)

Phillips, D.R.; Andermann, G.G.; Fujiwara, F.

1986-01-01

Sulfur-K/β /sub x-ray fluorescence spectroscopy (XFS) has been used to study the electronic structure and bonding in sulfur-bearing heterocycles. XFS not only has the capability of experimentally measuring valence electron energies in molecular species, but can also provide intensity data which can help define the nature of the molecular orbitals defined by the electrons. This report discusses the feasibility of using XFS as an analytical tool for the determination of total and specific sulfur heterocycle content in samples. A variety of compounds were studied. These include thiophene, thiophene derivatives, tetranydrothiophene, several more complex saturated and unsaturated sulfur heterocycles, and heterocycles containing both sulfur and nitrogen. The sulfur-K/β /sub spectra were obtained using a double crystal spectrometer which provided an instrumental resolution of about 0.7 eV

Stereoselective synthesis of organosulfur compounds incorporating N-aromatic heterocyclic motifs and quaternary carbon centers via a sulfa-Michael triggered tandem reaction.

Science.gov (United States)

Qin, Tianyou; Cheng, Lu; Zhang, Sean Xiao-An; Liao, Weiwei

2015-06-14

A novel sulfa-Michael addition (SMA)-triggered tandem reaction was developed by combining a SMA reaction with a simultaneous rearomatization process utilizing a less reactive carbonyl group as an intramolecular electrophile partner, which provided a unique synthetic route to access various organosulfur compounds incorporating an N-aromatic heterocyclic motif and quaternary carbon centers.

Heterocyclic organobismuth (III) compounds containing an eight-membered ring: Inhibitory effects on cell cycle progression.

Science.gov (United States)

Iuchi, Katsuya; Yagura, Tatsuo

2018-03-21

We previously showed that heterocyclic organobismuth compounds have excellent antimicrobial and antitumor potential. These compounds structurally consist of either six- or eight-membered rings. Previous research has shown that bi-chlorodibenzo[c,f][1,5]thiabismocine (Compound 3), an eight-membered ring, induced G 2 /M arrest via inhibition of tubulin polymerization in HeLa cells. Additionally, N-tert-butyl-bi-chlorodi-benzo[c,f][1,5]azabismocine (Compound 1), another eight-membered ring, exhibited higher cytotoxicity than Compound 3 against several cancer cell lines, including HeLa and K562. Finally, bi-chlorophenothiabismin-S,S-dioxide (Compound 5), a six-membered ring, exhibited lower antitumor activity than eight-membered ring compounds. In this study, we investigated the antimitotic activity of Compounds 1 and 5 in HeLa cells. At low concentrations, (0.1 and 0.25 μM), Compound 1 inhibited cell growth and arrested the cell cycle in mitosis. However, 0.5 μM Compound 1 exhibited no antimitotic activity. Conversely, Compound 5 weakly inhibited cell growth and did not markedly arrest the cell cycle. Flow cytometry showed that Compound 1 arrested the cell cycle at G 2 /M, resulting in apoptosis. Compound 1 inhibited tubulin polymerization as revealed by a cell-free assay, and both Compounds 1 and 3 inhibited microtubule spindle formation and chromosome alignment during prometaphase. These results suggest that eight-membered ring-containing organobismuth compounds can induce mitotic arrest by perturbing spindle dynamics. Copyright © 2018. Published by Elsevier Ltd.

Anoxic degradation of nitrogenous heterocyclic compounds by activated sludge and their active sites.

Science.gov (United States)

Xu, Peng; Han, Hongjun; Zhuang, Haifeng; Hou, Baolin; Jia, Shengyong; Wang, Dexin; Li, Kun; Zhao, Qian

2015-05-01

The potential for degradation of five nitrogenous heterocyclic compounds (NHCs), i.e., imidazole, pyridine, indole, quinoline, and carbazole, was investigated under anoxic conditions with acclimated activated sludge. Results showed that NHCs with initial concentration of 50 mg/L could be completely degraded within 60 hr. The degradation of five NHCs was dependent upon the chemical structures with the following sequence: imidazole>pyridine>indole>quinoline>carbazole in terms of their degradation rates. Quantitative structure-biodegradability relationship studies of the five NHCs showed that the anoxic degradation rates were correlated well with highest occupied molecular orbital. Additionally, the active sites of NHCs identified by calculation were confirmed by analysis of intermediates using gas chromatography and mass spectrometry. Copyright © 2015. Published by Elsevier B.V.

Syntheses of Azo-Imine Derivatives from Vanillin as an Acid Base Indicator

Directory of Open Access Journals (Sweden)

Bambang Purwono

2013-05-01

Full Text Available Preparations of azo, imine and azo-imine derivatives from vanillin as an indicator of acid-base titration have been carried out. The azo derivative of 4-hydroxy-3-methoxy-5-(phenylazobenzaldehyde 2 was produced by diazotitation reaction of vanillin in 37.04% yield. The azo product was then refluxed with aniline in ethanol to yield azo-imine derivatives, 2-methoxy-6-(phenylazo-4-((phenyliminomethylphenol 1 in 82.21% yield. The imine derivative, 2-methoxy-4-((phenyliminomethyl-phenol 3 was obtained by refluxing of vanillin and aniline mixture in ethanol solvent and produced 82.17% yield. The imine product was then reacted with benzenediazonium chloride salt. However, the products indicated hydrolyzed product of 4-hydroxy-3-methoxy-5-(phenylazobenzaldehyde 2 in 22.15% yield. The 2-methoxy-4-((phenyliminomethylphenol 2 could be used as an indicator for titration of NaOH by H2C2O4 with maximum concentration of H2C2O4 0.1 M while the target compound 1 could be used as titration indicator for titration of NaOH with H2C2O4 with same result using phenolphthalein indicator.

40 CFR 721.2577 - Copper complex of (substituted sulfonaphthyl azo substituted phenyl) disulfonaphthyl azo, amine...

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Copper complex of (substituted... Copper complex of (substituted sulfonaphthyl azo substituted phenyl) disulfonaphthyl azo, amine salt... substances identified generically as copper complex of (substituted sulfonaphthyl azo substituted phenyl...

Heterocyclic Nanographenes and Other Polycyclic Heteroaromatic Compounds: Synthetic Routes, Properties, and Applications.

Science.gov (United States)

Stępień, Marcin; Gońka, Elżbieta; Żyła, Marika; Sprutta, Natasza

2017-02-22

Two-dimensionally extended, polycyclic heteroaromatic molecules (heterocyclic nanographenes) are a highly versatile class of organic materials, applicable as functional chromophores and organic semiconductors. In this Review, we discuss the rich chemistry of large heteroaromatics, focusing on their synthesis, electronic properties, and applications in materials science. This Review summarizes the historical development and current state of the art in this rapidly expanding field of research, which has become one of the key exploration areas of modern heterocyclic chemistry.

Comprehensive database of Manufactured Gas Plant tars. Part C. Heterocyclic and hydroxylated polycyclic aromatic hydrocarbons.

Science.gov (United States)

Gallacher, Christopher; Thomas, Russell; Lord, Richard; Kalin, Robert M; Taylor, Chris

2017-08-15

Coal tars are a mixture of organic and inorganic compounds that were by-products from the manufactured gas and coke making industries. The tar compositions varied depending on many factors such as the temperature of production and the type of retort used. For this reason a comprehensive database of the compounds found in different tar types is of value to understand both how their compositions differ and what potential chemical hazards are present. This study focuses on the heterocyclic and hydroxylated compounds present in a database produced from 16 different tars from five different production processes. Samples of coal tar were extracted using accelerated solvent extraction (ASE) and derivatized post-extraction using N,O-bis(trimethylsilyl)trifluoroacetamide (BSTFA) with 1% trimethylchlorosilane (TMCS). The derivatized samples were analysed using two-dimensional gas chromatography combined with time-of-flight mass spectrometry (GCxGC/TOFMS). A total of 865 heterocyclic compounds and 359 hydroxylated polycyclic aromatic hydrocarbons (PAHs) were detected in 16 tar samples produced by five different processes. The contents of both heterocyclic and hydroxylated PAHs varied greatly with the production process used, with the heterocyclic compounds giving information about the feedstock used. Of the 359 hydroxylated PAHs detected the majority would not have been be detected without the use of derivatization. Coal tars produced using different production processes and feedstocks yielded tars with significantly different heterocyclic and hydroxylated contents. The concentrations of the individual heterocyclic compounds varied greatly even within the different production processes and provided information about the feedstock used to produce the tars. The hydroxylated PAH content of the samples provided important analytical information that would otherwise not have been obtained without the use of derivatization and GCxGC/TOFMS. Copyright © 2017 John Wiley & Sons, Ltd.

Oxygenated heterocyclic compounds to differentiate Citrus spp. essential oils through metabolomic strategies.

Science.gov (United States)

Masson, Jerome; Liberto, Erica; Beolor, Jean-Claude; Brevard, Hugues; Bicchi, Carlo; Rubiolo, Patrizia

2016-09-01

This study aimed to characterise and discriminate 44 authenticated commercial samples of citrus essential oils (EO) from seven species (bergamot, lemon, bigarade, orange, mandarin, grapefruit, lime) by analysing the non-volatile oxygenated heterocyclic compounds (OHC) by UHPLC/TOF-HRMS, multivariate data analysis (PCA, PLS-DA) and metabolomic strategies; the OHC fraction includes coumarins, furocoumarins, and polymethoxylated flavonoids. Two different approaches were adopted: (i) targeted profiling based on quantifying 18 furocoumarins and coumarins, some of which are regulated by law, and (ii) targeted fingerprinting based on 140 OHCs reported in citrus essential oils, from which 38 discriminant markers were defined. This approach correctly discriminated the Citrus species; its "sensitivity" to relatively low adulteration rate (10%) was highly satisfactory. The proposed method is complementary to that of analysing the citrus EO volatile part by GC techniques. Copyright © 2016 Elsevier Ltd. All rights reserved.

Synthesis and antiacetylcholinesterase activity of new D-glyceraldehyde heterocyclic derivatives

Energy Technology Data Exchange (ETDEWEB)

Scorzo, Cecilia M.; Fascio, Mirta L.; D' Accorso, Norma B. [Universidad de Buenos Aires, Buenos Aires (Argentina). Facultad de Ciencias Exactas y Naturales. Dept. de Quimica Organica; Cabrera, Margarita Gutierrez; Saavedra, Luis Astudillo [Universidad de Talca (Chile). Inst. de Quimica de Productos Naturales. Lab. de Sintesis Organica

2010-07-01

We report herein the convenient procedures for the syntheses of different heterocyclic compounds from 2,3-O-isopropylidene-D-glyceraldehyde using intramolecular cyclization, 1,3-dipolar cycloaddition or bimolecular coupling reactions. The products were characterized by {sup 1}H and {sup 13}C NMR spectroscopy and elemental analysis. The new heterocycles and their derivatives were evaluated as inhibitors of acetylcholinesterase enzyme. (author)

Synthesis and antiacetylcholinesterase activity of new D-glyceraldehyde heterocyclic derivatives

International Nuclear Information System (INIS)

Scorzo, Cecilia M.; Fascio, Mirta L.; D'Accorso, Norma B.; Cabrera, Margarita Gutierrez; Saavedra, Luis Astudillo

2010-01-01

We report herein the convenient procedures for the syntheses of different heterocyclic compounds from 2,3-O-isopropylidene-D-glyceraldehyde using intramolecular cyclization, 1,3-dipolar cycloaddition or bimolecular coupling reactions. The products were characterized by 1 H and 13 C NMR spectroscopy and elemental analysis. The new heterocycles and their derivatives were evaluated as inhibitors of acetylcholinesterase enzyme. (author)

New Approaches for the Synthesis, Cytotoxicity and Toxicity of Heterocyclic Compounds Derived from 2-Cyanomethylbenzo[c]imidazole.

Science.gov (United States)

Mohareb, Rafat M; Mohamed, Abeer A; Abdallah, Amira E M

2016-01-01

The reaction of ethyl cyanoacetate with o-phenylenediamine gave the 2-cyanomethylbenzo[c]imidazole (1). The latter compound was used as the key starting material to synthesise biologically active heterocyclic derivatives. Thus, the reaction of 1 with cyclohexanone and either of benzaldehyde, 4-methoxybenzaldehyde or 4-chlorobenzaldehyde gave the annulated derivatives 2a-c, respectively. The antitumor evaluations of the newly synthesized products against the three cancer cell lines MCF-7 (breast adeno-carcinoma), NCI-H460 (non-small cell lung cancer) and SF-268 (CNS cancer) showed that compounds 2b, 6, 11b, 11c, 12b, 16a, 16b and 18a exhibited optimal cytotoxic effect against cancer cell lines, with IC50 values in the nM range. Bioactive compounds are often toxic to shrimp larvae. Thus, in order to monitor these chemicals in vivo lethality to shrimp larvae (Artemia salina), Brine-Shrimp Lethality Assay was used. Compounds 11b, 12b and 16b showed no toxicity against the tested organisms.

Advances in heterocycle synthesis via [3+m]-cycloaddition reactions involving an azaoxyallyl cation as the key intermediate.

Science.gov (United States)

Xuan, Jun; Cao, Xia; Cheng, Xiao

2018-05-17

Heterocyclic compounds are widely found in many natural isolates and medicinally relevant compounds, as well as some fine chemicals. The development of general and efficient methods for the construction of heterocyclic compounds is one of the most important tasks in synthetic organic chemistry. Along these lines, [3+m]-cycloaddition reactions involving in situ generated azaoxyallyl cations as the 3-atom units have emerged as a powerful method for the synthesis of nitrogen-containing heterocycles. In this feature article, we highlight recent advances in this rapidly growing area, mainly focusing on the reaction design as well as the reaction mechanism.

Azo dye reduction by mesophilic and thermophilic anaerobic consortia

NARCIS (Netherlands)

Santos, dos A.B.; Madrid, de M.P.; Stams, A.J.M.; Lier, van J.B.; Cervantes, F.J.

2005-01-01

The reduction of the azo dye model compounds Reactive Red 2 (RR2) and Reactive Orange 14 (RO14) by mesophilic (30 C) and thermophilic (55 C) anaerobic consortia was studied in batch assays. The contribution of fermentative and methanogenic microorganisms in both temperatures was evaluated in the

Knock-Limited Power Outputs from a CFR Engine Using Internal Coolants. 3; Four Alkyl Amines, Three Alkanolamines, Six Amides, and Eight Heterocyclic Compounds

Science.gov (United States)

Imming, Harry S.; Bellman, Donald R.

1947-01-01

An investigation of the antiknock effectiveness of various additive-water solutions when used as internal coolants has been conducted at the NACA Cleveland laboratory. Nine compounds have been previously run in a CFR engine and the results are presented. In an effort to find a good anti-knock-coolant additive with more desirable physical properties than those of the nine compounds previously investigated, water solutions of four alkyl amines, three alkanolamines, six amides, and eight heterocyclic compounds were investigated and the results are presented.

Chlorine disinfection of dye wastewater: Implications for a commercial azo dye mixture

Energy Technology Data Exchange (ETDEWEB)

Vacchi, Francine Inforcato; Albuquerque, Anjaina Fernandes; Vendemiatti, Josiane Aparecida; Morales, Daniel Alexandre [Faculdade de Tecnologia, Universidade Estadual de Campinas, Limeira, SP, 13484-332 (Brazil); Ormond, Alexandra B.; Freeman, Harold S. [Department of Textile Engineering, Chemistry, and Science, North Carolina State University, Raleigh, NC 27695-8301 (United States); Zocolo, Guilherme Juliao; Zanoni, Maria Valnice Boldrin [Departamento de Quimica Analitica, Universidade Estadual Paulista Julio de Mesquita Filho, Instituto de Quimica de Araraquara, Araraquara, SP 14801-970 (Brazil); Umbuzeiro, Gisela, E-mail: giselau@ft.unicamp.br [Faculdade de Tecnologia, Universidade Estadual de Campinas, Limeira, SP, 13484-332 (Brazil)

2013-01-01

Azo dyes, the most widely used family of synthetic dyes, are often employed as colorants in areas such as textiles, plastics, foods/drugs/cosmetics, and electronics. Following their use in industrial applications, azo dyes have been found in effluents and various receiving waters. Chemical treatment of effluents containing azo dyes includes disinfection using chlorine, which can generate compounds of varying eco/genotoxicity. Among the widely known commercial azo dyes for synthetic fibers is C.I. Disperse Red 1. While this dye is known to exist as a complex mixture, reports of eco/genotoxicity involve the purified form. Bearing in mind the potential for adverse synergistic effects arising from exposures to chemical mixtures, the aim of the present study was to characterize the components of commercial Disperse Red 1 and its chlorine-mediated decoloration products and to evaluate their ecotoxicity and mutagenicity. In conducting the present study, Disperse Red 1 was treated with chlorine gas, and the solution obtained was analyzed with the aid of LC-ESI-MS/MS to identify the components present, and then evaluated for ecotoxicity and mutagenicity, using Daphnia similis and Salmonella/microsome assays, respectively. The results of this study indicated that chlorination of Disperse Red 1 produced four chlorinated aromatic compounds as the main products and that the degradation products were more ecotoxic than the parent dye. These results suggest that a disinfection process using chlorine should be avoided for effluents containing hydrophobic azo dyes such commercial Disperse Red 1. -- Highlights: Black-Right-Pointing-Pointer Aqueous solutions of Disperse Red 1 were treated with chlorine. Black-Right-Pointing-Pointer The chlorination products of Disperse Red 1 were identified using LC-ESI-MS/MS. Black-Right-Pointing-Pointer Daphnia and Salmonella/microsome were employed for eco/genotoxicity testing. Black-Right-Pointing-Pointer The chlorinated dye was more mutagenic

Preparation of deuterated heterocyclic five-membered ring compounds (furan, thiophene, pyrrole, and derivatives) by base-catalyzed hydrogen isotope exchange with deuterium oxide

International Nuclear Information System (INIS)

Heinrich, K.H.; Herrmann, M.; Moebius, G.; Sprinz, H.

1984-01-01

Several deuterated heterocyclic compounds of the type of furan,thiophene and pyrrole were prepared by base-catalyzed proton exchange with deuterium oxide at temperatures above 423 K in a closed system. The determination of deuterium and its distribution within the molecules was carried out by mass spectrometry and 1 H nmr spectrometry. (author)

Photoresists for Microlithography

Indian Academy of Sciences (India)

otherwise and listening to music both Indian and western: classical and modem. S V Eswaran has worked on lac resin, heterocycles and ... These free positions can undergo azo coupling reac- tion in the unexposed part with the photo active component, viz. the diazo compound. The consequent increase in IIl:olecular.

Novel zinc(II)phthalocyanines bearing azo-containing schiff base: Determination of pKa values, absorption, emission, enzyme inhibition and photochemical properties

Science.gov (United States)

Kantar, Cihan; Mavi, Vildan; Baltaş, Nimet; İslamoğlu, Fatih; Şaşmaz, Selami

2016-10-01

Azo-containing schiff bases are well known and there are many studies about their various properties in literature. However, phthalocyanines bearing azo-containing schiff bases, their spectral, analytical and biological properties are unknown. Therefore, new zinc (II) phthalocyanines bearing azo-containing schiff base were synthesized and investigated to determine pKa values, absorption, emission, enzyme inhibition and photochemical properties. Emission spectra were reported and large Stokes shift values were determined for all compounds, indicating that all molecules exhibit excited state intramolecular proton transfer. These phthalocyanines were the first examples of phthalocyanine showing excited state intramolecular proton transfer. Singlet oxygen quantum yields of zinc (II) phthalocyanines were determined. pKa values and indicator properties of all compounds were investigated by potentiometry. All compounds were assayed for inhibitory activity against bovine milk xanthine oxidase and acetylcholinesterase enzyme in vitro. Compound 2 showed the high inhibitory effect against xanthine oxidase (IC50 = 0.24 ± 0.01 μM). However, phthalocyanine compounds did not show enzyme inhibitor behavior.

Synthesis and characterization of 5-amino-2-((3-hydroxy-4-((3-hydroxyphenyl phenyl diazenyl phenol and its Cu(II complex – a strategy toward developing azo complexes for reduction of cytotoxicity

Directory of Open Access Journals (Sweden)

Durba Ganguly

2014-12-01

Full Text Available A major drawback of azo compounds is their associated toxicity, often carcinogenic, which is related to the reduction of the azo bond. This study intends to re-investigate this behavior by studying 5-amino-2-((3-hydroxy-4-((3-hydroxyphenyl phenyl diazenyl phenol (AHPD, a compound containing two azo bonds. Interaction of AHPD and its dimeric Cu(II complex with bacterial strains Escherichia coli and Staphylococcus aureus revealed the complex was less toxic. Reductive cleavage of the azo bond in AHPD and the complex followed using cytochrome c reductase (a model azo-reductase as well as azo-reductase enzymes obtained from bacterial cell extracts. Degradation of the azo bond was less in the complex allowing us to correlate the observed cytotoxicity. Cyclic voltammetry on AHPD and the complex support observations of enzyme assay experiments. These were particularly useful in realizing the formation of amines as an outcome of the reductive cleavage of azo bonds in AHPD that could not be identified through an enzyme assay. Results suggest that complex formation of azo compounds could be a means to control the formation of amines responsible for cytotoxicity. Studies carried out on bacterial cells for mere simplicity bear significance for multicellular organisms and could be important for human beings involved with the preparation and utilization of azo dyes.

synthesis and characterization of some poly functionalized heterocyclic derivatives of expected biological activity

International Nuclear Information System (INIS)

El-sayed, M.S.

2001-01-01

The present work was aimed and designed to fulfil The following objectives : 1- Continuation of the effort done by our research group in the field of chemistry of pyridinethione derivatives and their biological activities. 2- Synthesis of several new heterocyclic derivatives containing N and/or S using the laboratory available reagents. 3- Establishment of the structures of the newly synthesized heterocyclic compounds by the data of IR, 1 H-NMR, mass spectra in addition to the elemental analysis. 4- Synthesis of some of these heterocyclic derivatives via alternative routs and this used as a tool to confirm the structures of the newly synthesized heterocyclic derivatives. 5- study of the most probable mechanisms leading to the formation of the new heterocyclic derivatives. 6- The antimicrobial activity of some of the newly synthesized heterocyclic derivatives was tested against several types of organisms

Synthesis and evaluation of mutual azo prodrug of 5-aminosalicylic acid linked to 2-phenylbenzoxazole-2-yl-5-acetic acid in ulcerative colitis

Directory of Open Access Journals (Sweden)

Jilani JA

2013-07-01

Full Text Available Jamal A Jilani,1 Maha Shomaf,2 Karem H Alzoubi3 1Department of Medicinal Chemistry and Pharmacognosy, Jordan University of Science and Technology, Irbid, Jordan; 2Department of Pathology, Jordan University, Amman, Jordan; 3Department of Clinical Pharmacy, Jordan University of Science and Technology, Irbid, Jordan Abstract: In this study, the syntheses of 4-aminophenylbenzoxazol-2-yl-5-acetic acid, (an analogue of a known nonsteroidal anti-inflammatory drug [NSAID] and 5-[4-(benzoxazol-2-yl-5-acetic acidphenylazo]-2-hydroxybenzoic acid (a novel mutual azo prodrug of 5-aminosalicylic acid [5-ASA] are reported. The structures of the synthesized compounds were confirmed using infrared (IR, hydrogen-1 nuclear magnetic resonance (1H NMR, and mass spectrometry (MS spectroscopy. Incubation of the azo compound with rat cecal contents demonstrated the susceptibility of the prepared azo prodrug to bacterial azoreductase enzyme. The azo compound and the 4-aminophenylbenzoxazol-2-yl-5-acetic acid were evaluated for inflammatory bowel diseases, in trinitrobenzenesulfonic acid (TNB-induced colitis in rats. The synthesized diazo compound and the 4-aminophenylbenzoxazol-2-yl-5-acetic acid were found to be as effective as 5-aminosalicylic acid for ulcerative colitis. The results of this work suggest that the 4-aminophenylbenzoxazol-2-yl-5-acetic acid may represent a new lead for treatment of ulcerative colitis. Keywords: benzoxazole acetic acid, azo prodrug, colon drug delivery

Effects of nitro-heterocyclic derivatives against Leishmania (Leishmania) infantum promastigotes and intracellular amastigotes.

Science.gov (United States)

Petri e Silva, Simone Carolina Soares; Palace-Berl, Fanny; Tavares, Leoberto Costa; Soares, Sandra Regina Castro; Lindoso, José Angelo Lauletta

2016-04-01

Leishmaniasis is an overlooked tropical disease affecting approximately 1 million people in several countries. Clinical manifestation depends on the interaction between Leishmania and the host's immune response. Currently available treatment options for leishmaniasis are limited and induce severe side effects. In this research, we tested nitro-heterocyclic compounds (BSF series) as a new alternative against Leishmania. Its activity was measured in Leishmania (Leishmania) infantum promastigotes and intracellular amastigotes using MTT colorimetric assay. Additionally, we assessed the phosphatidylserine exposure by promastigotes, measured by flow cytometry, as well as nitric oxide production, measured by Griess' method. The nitro-heterocyclic compounds (BSF series) showed activity against L. (L.) infantum promastigotes, inducting the phosphatidylserine exposition by promastigotes, decreasing intracellular amastigotes and increasing oxide nitric production. The selectivity index was more prominent to Leishmania than to macrophages. Compared to amphotericin b, our compounds presented higher IC50, however the selectivity index was more specific to parasite than to amphotericin b. In conclusion, these nitro-heterocyclic compounds showed to be promising as an anti-Leishmania drug, in in vitro studies. Copyright © 2016 Elsevier Inc. All rights reserved.

Pyrrole PMOs, incorporating new N-heterocyclic compounds on an ethene-PMO through Diels–Alder reactions

International Nuclear Information System (INIS)

Esquivel, Dolores; De Canck, Els; Jiménez-Sanchidrián, César; Romero-Salguero, Francisco J.; Van Der Voort, Pascal

2014-01-01

The ethenylene bridges on the walls of an ethenylene-bridged periodic mesoporous organosilica were successfully modified with a variety of pyrrole derivatives – pyrrole, methylpyrrole, dimethylpyrrole, trimethylpyrrole and 1-phenylpyrrole – through Diels–Alder reactions. X-ray diffraction measurements and N 2 adsorption–desorption analysis confirmed the preservation of the ordering and mesoporosity of the parent material as well as the decoration of the pores with the surface Diels–Alder adducts. Moreover, other techniques such as DRIFT, 13 C and 29 Si nuclear magnetic resonances revealed the formation of the surface N-heterocyclic compounds at the parent ethenylene sites. - Highlights: • Chemical modification of the double bonds on an ethene-PMO through the Diels–Alder reaction. • A family of pyrrole derivatives act as dienes in the Diels–Alder reaction. • Well-ordering and mesoporosity are retained after the post-functionalization. • N-containing compounds on the surface of ethene-PMO are present after the Diels–Alder reaction

Pyrrole PMOs, incorporating new N-heterocyclic compounds on an ethene-PMO through Diels–Alder reactions

Energy Technology Data Exchange (ETDEWEB)

Esquivel, Dolores; De Canck, Els [Center for Ordered Materials, Organometallics and Catalysis, Department of Inorganic and Physical Chemistry, Ghent University, Krijgslaan 281-S3, 9000 Ghent (Belgium); Jiménez-Sanchidrián, César [Department of Organic Chemistry, Nanochemistry and Fine Chemistry Research Institute (IUIQFN), Faculty of Sciences, University of Córdoba, Campus de Rabanales, Marie Curie Building, Ctra. Nnal. IV, km 396, 14071 Córdoba (Spain); Romero-Salguero, Francisco J., E-mail: qo2rosaf@uco.es [Department of Organic Chemistry, Nanochemistry and Fine Chemistry Research Institute (IUIQFN), Faculty of Sciences, University of Córdoba, Campus de Rabanales, Marie Curie Building, Ctra. Nnal. IV, km 396, 14071 Córdoba (Spain); Van Der Voort, Pascal, E-mail: pascal.vandervoort@ugent.be [Center for Ordered Materials, Organometallics and Catalysis, Department of Inorganic and Physical Chemistry, Ghent University, Krijgslaan 281-S3, 9000 Ghent (Belgium)

2014-11-14

The ethenylene bridges on the walls of an ethenylene-bridged periodic mesoporous organosilica were successfully modified with a variety of pyrrole derivatives – pyrrole, methylpyrrole, dimethylpyrrole, trimethylpyrrole and 1-phenylpyrrole – through Diels–Alder reactions. X-ray diffraction measurements and N{sub 2} adsorption–desorption analysis confirmed the preservation of the ordering and mesoporosity of the parent material as well as the decoration of the pores with the surface Diels–Alder adducts. Moreover, other techniques such as DRIFT, {sup 13}C and {sup 29}Si nuclear magnetic resonances revealed the formation of the surface N-heterocyclic compounds at the parent ethenylene sites. - Highlights: • Chemical modification of the double bonds on an ethene-PMO through the Diels–Alder reaction. • A family of pyrrole derivatives act as dienes in the Diels–Alder reaction. • Well-ordering and mesoporosity are retained after the post-functionalization. • N-containing compounds on the surface of ethene-PMO are present after the Diels–Alder reaction.

Photoprotective effect and acute oral systemic toxicity evaluation of the novel heterocyclic compound LQFM048.

Science.gov (United States)

Vinhal, Daniela C; de Ávila, Renato Ivan; Vieira, Marcelo S; Luzin, Rangel M; Quintino, Michelle P; Nunes, Liliane M; Ribeiro, Antonio Carlos Chaves; de Camargo, Henrique Santiago; Pinto, Angelo C; Dos Santos Júnior, Helvécio M; Chiari, Bruna G; Isaac, Vera; Valadares, Marize C; Martins, Tatiana Duque; Lião, Luciano M; de S Gil, Eric; Menegatti, Ricardo

2016-08-01

The new heterocyclic derivative LQFM048 (3) (2,4,6-tris ((E)-ethyl 2-cyano-3-(4-hydroxy-3-methoxyphenyl)acrylate)-1,3,5-triazine) was originally designed through the molecular hybridization strategy from Uvinul® T 150 (1) and (E)-ethyl 2-cyano-3-(4hydroxy-3-methoxyphenyl)acrylate (2) sunscreens, using green chemistry approach. This compound was obtained in global yields (80%) and showed an interesting redox potential. In addition, it is thermally stable up to temperatures around 250°C. It was observed that LQFM048 (3) showed a low degradation after 150min of sunlight exposure at 39°C, whereas the extreme radiation conditions induced a considerable photodegradation of the LQFM048 (3), especially when irradiated by VIS and VIS+UVA. During the determination of sun protection factor, LQFM048 (3) showed interesting results, specially as in association with other photoprotective compounds and commercial sunscreen. Additionally, the compound (3) did not promote cytotoxicity for 3T3 fibroblasts. Moreover, it was not able to trigger acute oral systemic toxicity in mice, being classified as a compound with low acute toxicity hazard (2.000mg/kg>LD50compound synthesized using green chemistry approach is promising showing potential to development of a new sunscreen product with advantage of presenting redox potential, indicating antioxidant properties. Copyright © 2016 Elsevier B.V. All rights reserved.

Asymmetrical/symmetrical D-π-A/D-π-D thiazole-containing aromatic heterocyclic fluorescent compounds having the same triphenylamino chromophores.

Science.gov (United States)

Tao, Tao; Ma, Bin-Bin; Peng, Yu-Xin; Wang, Xiao-Xu; Huang, Wei; You, Xiao-Zeng

2013-09-06

A family of linear asymmetrical D-π-A and symmetrical D-π-D types of thiazole-based aromatic heterocyclic fluorescent compounds bearing various electron-donating and electron-withdrawing tails (bromo, triphenylamino, pyridyl, thienyl and benzoic acid) have been designed and prepared successfully. Synthetic, structural, thermal, spectral and computational comparisons have been carried out for related compounds because of their adjustable electronic properties. It is interesting to mention that compound 2 can be prepared from 5-bromothiazole by one-pot Suzuki-Miyaura coupling and subsequent C-H activation reactions via a 5-TPA-substituted thiazole intermediate 1. X-ray single-crystal structures of six compounds indicate that they all crystallize in the triclinic P1 space group and the thiazole core exhibits different dihedral angles with its adjacent benzene ring of the triphenylamino group (3.6(3)-40.8(3)°). The photophysical and electrochemical results demonstrate that compound 7 exhibits high electrochemical activity with a green fluorescence emission. Meanwhile, compounds 1, 2, and 6 show high luminescence quantum yields, and compound 8 exhibits excellent thermal stability (T(d(10)) = 503 °C).

Thermally Stable Heterocyclic Imines as New Potential Nonlinear Optical Materials

Science.gov (United States)

Nesterov, Volodymyr V.; Antipin, Mikhail Y.; Nesterov, Vladimir N.; Moore, Craig E.; Cardelino, Beatriz H.; Timofeeva, Tatiana V.

2004-01-01

In the course of a search for new thermostable acentric nonlinear optical crystalline materials, several heterocyclic imine derivatives were designed, with the general structure D-pi-A(D'). Introduction of a donor amino group (D') into the acceptor moiety was expected to bring H-bonds into their crystal structures, and so to elevate their melting points and assist in an acentric molecular packing. Six heterocycle-containing compounds of this type were prepared, single crystals were grown for five of them, and these crystals were characterized by X-ray analysis. A significant melting temperature elevation was found for all of the synthesized compounds. Three of the compounds were also found to crystallize in acentric space groups. One of the acentric compounds is built as a three-dimensional H-bonded molecular network. In the other two compounds, with very similar molecular structure, the molecules form one-dimensional H-bonded head-to-head associates (chains). These chains are parallel in two different crystallographic directions and form very unusual interpenetrating chain patterns in an acentric crystal. Two of the compounds crystallized with centrosymmetric molecular packing.

Research on Synthesis of New Azo Calix[4]arene and its Dyeing Properties

Directory of Open Access Journals (Sweden)

Tang Jun

2015-01-01

Full Text Available With the raw materials of calix[4]arene, benzocaine, tricaine and procaine hydrochloride, three new azo calix[4]arene derivatives—6a, 6b and 6c are synthesized by diazotization–coupling reaction of an aromatic amine, with its yield of 83%, 81% and 83% respectively. The structural characterization is in a way of IR, 1H NMR and elemental analysis. This paper investigates the spectral properties of azo calix[4]arene derivatives under different solution pH conditions through the UV–visible spectroscopy, and researches the dyeing properties through the dyeing curve, color yield test and fastness test. The results show that, with the increase of pH value, the azo calix[4]arene derivatives—6a, 6b and 6c form azo–hydrazone tautomeric isomers with the maximum absorption peak redshift; the dyeing effect of the compound is good, of which the dye–uptake rate of the compound 6a is as high as 78%; the surface depth of color yield is 2.798, and the dry and wet rubbing fastness and the soaping fastness are respectively 4, which is a better disperse dye.

Asymmetric Hydrogenation of Seven-Membered C=N-containing Heterocycles and Rationalization of the Enantioselectivity.

Science.gov (United States)

Balakrishna, Bugga; Bauzá, Antonio; Frontera, Antonio; Vidal-Ferran, Anton

2016-07-18

Iridium(I) complexes with phosphine-phosphite ligands efficiently catalyze the enantioselective hydrogenation of diverse seven-membered C=N-containing heterocyclic compounds (eleven examples; up to 97 % ee). The P-OP ligand L3, which incorporates an ortho-diphenyl substituted octahydrobinol phosphite fragment, provided the highest enantioselectivities in the hydrogenation of most of the heterocyclic compounds studied. The observed stereoselection was rationalized by means of DFT calculations. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Stereodivergent Synthesis of N-Heterocycles by Catalyst-Controlled, Activity-Directed Tandem Annulation of Diazo Compounds with Amino Alkynes.

Science.gov (United States)

Liu, Kai; Zhu, Chenghao; Min, Junxiang; Peng, Shiyong; Xu, Guangyang; Sun, Jiangtao

2015-10-26

A stereodivergent synthesis of five-membered N-heterocycles, such as 2,3-dihydropyrroles, and 2-methylene and 3-methylene pyrrolidines, has been developed through a tandem annulation of amino alkynes with diazo compounds and involves the trapping of in situ formed intermediates. Mechanistic investigations indicate that the copper-catalyzed tandem annulations proceed by allenoate formation and subsequent intramolecular hydroamination. In contrast, the rhodium-catalyzed protocol features a carbenoid insertion into the NH bond and subsequent Conia-ene cyclization. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Ruthenium sulfoxides structure and reactivity with nitrogen heterocyclic bases

International Nuclear Information System (INIS)

Oliveira, Denise de.

1990-01-01

Ruthenium (II) sulfoxides are compounds of great interest in oxidative catalysis and in chemotherapy. In order to contribute for the understanding of the chemistry and electronic structure of this class of compounds, it has been studied a series of [Ru Cl 2 (S-DMSO) 2 L x ] complexes, where x = 1 (polymeric compounds) or 2 (monomers) and L N-heterocyclic ligands (pyridine, pyrazine and imidazole derivatives). The nature of N-heterocyclic ligand and their coordination are of great relevance to the stability, spectroscopic and electrochemical characteristics of the complexes. The trans-interactions are extremely important in this series, influencing the strength of the Ru(II)-> S-DMSO and Ru(II)-> L π-back donation. The DMSO and L ligands are π-acceptors. The metal-> ligand π-back donation is strengthened when the ligand is trans to chloride, which is π-donor, due to trans-cooperative interactions of the type: π-donor -> Ru(II) π-acceptor. Another interesting aspect in the series of [Ru Cl 2 (S-DMSO) 2 L 2 ] complexes is the occurrence of dissociative equilibria in the solution, due to the existence of three types of ligands. It was observed that the trans-N isomer of 2,6-dimethyl pyrazine derivative undergoes thermal substitution, with preferential liabilization of the N-heterocyclic ligand. Chloride ion is the most inert ligand in this complex. (author). 145 refs., 76 figs., 21 tabs

Heterocyclic N-oxides - A Promising Class of Agents Against Tuberculosis, Malaria and Neglected Tropical Diseases.

Science.gov (United States)

Dos Santos Fernandes, Guilherme Felipe; Pavan, Aline Renata; Dos Santos, Jean Leandro

2018-04-17

Heterocyclic N-oxides have emerged as promising agents against a number of diseases and disorders, especially infectious diseases. This review analyzes the emergence and development of this scaffold in the medicinal chemistry, focusing mainly on the discovery of new heterocyclic N-oxide compounds with potent activity against tuberculosis, malaria and neglected tropical diseases (i.e. leishmaniasis and Chagas disease). A number of heterocyclic N-oxide are described herein, nevertheless, the following chemical classes deserve to be highlighted due to the large number of reports in the literature about their promising pharmacological effects: furoxan, benzofuroxan, quinoxaline 1,4-di-N-oxide, indolone N-oxide and benzimidazole N-oxide. In order to describe those most promising compounds, we included in this review only those most biologically active heterocyclic N-oxide published since 2000. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Cytotoxic effects of chemotherapeutic drugs and heterocyclic compounds at application on the cells of primary culture of neuroepithelium tumors.

Science.gov (United States)

Kulchitsky, Vladimir A; Potkin, Vladimir I; Zubenko, Yuri S; Chernov, Alexander N; Talabaev, Michael V; Demidchik, Yuri E; Petkevich, Sergei K; Kazbanov, Vladimir V; Gurinovich, Tatiana A; Roeva, Margarita O; Grigoriev, Dmitry G; Kletskov, Alexei V; Kalunov, Vladimir N

2012-01-01

Neuroepithelial tumor cells were cultured in vitro. The biopsy material was taken from 93 children at removal of the brain tumors during neurosurgical operations. The individual features of the cells sensitivity of primary cultures in respect to protocol-approved chemotherapy drugs and changes in the Interleukin-6 (Il-6) level in the culture medium after the application of chemotherapy were established. The initial level of Il-6 exceeded 600.0 pg/ml in the cultural medium with histologically verified pilomyxoid astrocytoma cells, and ranged from 100.0 to 200.0 pg/ml in the medium at cultivation of ganglioneuroblastoma and pilocytic astrocytoma. A decrease in the Il-6 level in the medium culture of primary tumors cells was observed after the application of chemotherapeutic agents on the cells of pilomyxoid astrocytoma, astrocytomas, and pilocytic desmoplastic/nodular medulloblastoma. The production of Il-6 increased after application of cytostatic drugs on the cells of oligoastrocytomas. A decrease in Il-6 level after application of Cisplatin and Methotrexate and a 5-10 fold increase in the level of Il-6 after application of Etoposide, Carboplatin, Cytarabine, and Gemcitabine were registered in the medium with ganglioneuroblastoma. To improve the cytotoxic action of chemotherapeutic agents, the combined application of cytostatics with heterocyclic compounds was carried out. A computer modeling of ligand-protein complexes of carbamide using the Dock 6.4 and USF Chimera program packages was performed with molecular mechanics method. Special attention was drawn to the ability of several isoxazole heterocycles and isothiazolyl to inhibit the tyrosine kinase. It was proved in vitro that the joint application of chemotherapeutic agents and heterocyclic compounds could reduce the concentration of the cytostatic factor by 10 or more times, having maintained the maximum cytotoxic effect. It was assumed that the target amplification of cytotoxic action of chemotherapeutic

Synthesis of heterocycles through transition-metal-catalyzed isomerization reactions

DEFF Research Database (Denmark)

Ishøy, Mette; Nielsen, Thomas Eiland

2014-01-01

of structurally complex and diverse heterocycles. In this Concept article, we attempt to cover this area of research through a selection of recent versatile examples. A sea of opportunities! Transition-metal-catalyzed isomerization of N- and O-allylic compounds provides a mild, selective and synthetically...... versatile method to form iminium and oxocarbenium ions. Given the number of reactions involving these highly electrophilic intermediates, this concept provides a sea of opportunities for heterocycle synthesis, (see scheme; Nu=nucleophile). © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim....

Solar photoassisted advanced oxidation process of azo dyes.

Science.gov (United States)

Prato-Garcia, D; Buitrón, G

2009-01-01

Advanced oxidation processes assisted with natural solar radiation in CPC type reactors (parabolic collector compound), was applied for the degradation of three azo dyes: acid orange (AO7), acid red 151 (AR151) and acid blue 113 (AB113). Fenton, Fenton like and ferrioxalate-type complexes showed to be effective for degrade the azo linkage and moieties in different extensions. Initially, the best dose of reagents (Fe(3 + )-H(2)O(2)) was determined through a factorial experimental design, next, using response surface methodologies, the reagent consumption was reduced up to 40%, maintaining in all cases high decolourisation percentages (>98%) after 60 min. of phototreatment. In this work, it was also studied the effect of concentration changes of the influent between 100-300 mg/L and the operation of the photocatalytic process near neutral conditions (pH 6.0-6.5) by using ferrioxalate type complex (FeOx).

Handbook of heterocyclic chemistry

National Research Council Canada - National Science Library

Katritzky, Alan R

2010-01-01

... Heterocyclic Chemistry I (1984) Comprehensive Heterocyclic Chemistry II (1996) Comprehensive Heterocyclic Chemistry III (2008) Comprehensive Organic Functional Group Transformations I (1995) Compreh...

Design, synthesis and antibreast cancer MCF-7 cells biological evaluation of heterocyclic analogs of resveratrol.

Science.gov (United States)

Du, Cheng; Dong, Ming-Hui; Ren, Yu-Jie; Jin, Lu; Xu, Cheng

2017-09-01

A new series of resveratrol heterocyclic analogs (4a-m) were designed and synthesized, and their inhibitiory effects on MCF-7 cells were evaluated to investigate structure-activity relationship. The effects of these analogs on human breast cancer MCF-7 cells were also determined. Results showed that MCF-7 cells could be inhibited more potently by these analogs than by resveratrol (IC 50  = 80.0 μM). Among the analogs, compounds 4c, 4e, and 4k showed a significantly higher activity (IC 50  = 42.7, 48.1, and 43.4 μM) than resveratrol. Furthermore, the derivatives without additional heterocyclic structure in the 4'-OH position exhibited a more potent activity than that with addition heterocyclic structure. In addition, docking simulation was performed to adequately position compound 4c in a human F 1 -ATPase active site to determine a probable binding model. These heterocyclic analogs could be effective candidates for the chemoprevention of human breast cancer.

Greener Synthetic Alternatives to Heterocycles, Nanomaterials and Nanocomposites

Science.gov (United States)

Microwave (MW) expedited reaction of neat reactants or catalyzed by mineral support surfaces, such as alumina, silica, clay, or their ‘doped’ versions, for the rapid one-pot assembly of heterocyclic compounds from in situ generated reactive intermediates via enamines or using hyp...

Synthesis and properties of heterocyclic type I photoinitiators

International Nuclear Information System (INIS)

Liska, R.; Knaus, S.; Wendrinsky, J.

1999-01-01

The synthesis and properties of a series of new heterocyclic hydroxyalkylphenone-analogous photoinitiators (PIs) is described. The PIs are obtained by reaction of aromatic organolithium compounds with nitriles or by Friedel-Craft's-acylation. Preliminary photocalorimetric tests and UV absorption data are included

Structure of radicals produced by γ radiolysis. Part 4. Adamantane matrices doped with various 5-membered heterocyclic molecules

International Nuclear Information System (INIS)

Winters, D.L.; Ling, A.C.

1976-01-01

The effects of γ-radiolysis at room temperature on adamantane and adamantane-d 16 matrices doped with 5-membered heterocyclic molecules has been examined by X-band electron spin resonance (esr) spectrometry. Radical structures formed from heterocyclic solute molecules are discussed and tentative assignments made. Discussion of possible radical structures derived from selected heterocyclic compounds is included, but unambiguous assignmens of structure cannot be made for these compounds from the esr data obtained. It was noted that perdeuterated adamantane matrices provided superior resolution for esr spectra derived from radicals with a delocalized spin center such as allyl or allenyl species. (author)

EVALUATION OF THE ANTIMICROBIAL EFFECTS OF NEW HETEROCYCLIC BIS-QUATERNARY AMMONIUM COMPOUNDS ON BIOFILMS

Directory of Open Access Journals (Sweden)

OANA E. CONSTANTIN

2016-07-01

Full Text Available Considering the well-known mechanism of adaptable resistance of microorganisms to chemical compounds through biofilms formation and the widespread use of N-heterocyclic quaternary ammonium salts (QAC as disinfectants, in this study we have evaluate the effect of 8 newly synthesized symmetrical and unsymmetrical diquaternary ammonium salts of 1,2-bis-(4-pyridil-ethane on bacterial biofilms produced by three different bacterial strains. The effect of the exposure to quaternary ammonium salts on biofilm communities was investigated within biofilms obtained in a conventional testing system, on stainless steel and glass surfaces. Differential plate counts were used to characterize the developed communities and the effects of QAC exposure and the results were correlated with epifluorescence microphotographs. The data obtained revealed a significant reduction of bacterial cells in the biofilms tested with 4-7 log CFU for all the QAC.

Mineralization of polycyclic and n-heterocyclic aromatic compounds in hydrocarbon-contaminated soils

International Nuclear Information System (INIS)

Grosser, R.J.; Warshawsky, D.; Vestal, J.R.

1995-01-01

The comparative mineralization of eight polycyclic aromatic compounds in five soils collected from an abandoned coal tar refinery in eastern Ohio was determined. The soils showed differences only in total extractable hydrocarbon content of the soil chemical characteristics measured. The compounds studied included five polycyclic aromatic hydrocarbons (phenanthrene, anthracene, pyrene, and carcinogenic benz[a]anthracene and benzo[a]pyrene) and three N-heterocyclic aromatics (9H-carbazole, and carcinogenic 7H-dibenzo[c,g]carbazole and dibenz[a,j]acridine). Mineralization was measured by serum bottle radiorespirometry. Only phenanthrene, anthracene, pyrene, benz[a]anthracene, and carbazole were mineralized in the soils after 64 d. Two of the soils with eight to 15 times the hexane -extractable hydrocarbon content consistently showed more rapid initial rates and higher overall extents of mineralization compared to the other three soils. Overall extents of mineralization ranged from 38 to 55% for phenanthrene, 10 to 60% for anthracene, 25 to 70% for pyrene, background to 40% for benz[a]anthracene, and 25 to 50% for carbazole after 64 d. Extents of mineralization by indigenous soil microbiota appear to be more dependent on the chemical characteristics of the soil and not soil total biomass and activity. Cultures capable of degrading phenanthrene, anthracene, and pyrene were obtained following enrichment techniques. A Mycobacterium sp. capable of degrading these three compounds was isolated and reintroduced into two of the soils, resulting in mineralization enhanced above that of the indigenous soil microbial population. These data indicate that the future success of bioremediation methods relies on the characterization of environmental parameters affecting microbial degradation as well as the isolation of microbial populations that can reduce toxicity in the environment

N,S,O-Heterocycles in Aged Champagne Reserve Wines and Correlation with Free Amino Acid Concentrations.

Science.gov (United States)

Le Menn, Nicolas; Marchand, Stephanie; de Revel, Gilles; Demarville, Dominique; Laborde, Delphine; Marchal, Richard

2017-03-22

Champagne regulations allow winegrowers to stock still wines to compensate for quality shifts in vintages, mainly due to climate variations. According to their technical requirements and house style, Champagne producers use these stored wines in their blends to enhance complexity. The presence of lees and aging at low pH (2.95-3.15), as in Champagne wines, lead to several modifications in wine composition. These conditions, combined with extended aging, result in the required environment for the Maillard chemical reaction, involving aromatic molecules, including sulfur, oxygen, and nitrogen heterocycles (such as thiazole, furan, and pyrazine derivatives), which may have a sensory impact on wine. Some aromatic heterocycles in 50 monovarietal wines aged from 1 to 27 years provided by Veuve Clicquot Ponsardin Champagne house were determined by the SPME-GC-MS method. The most interesting result highlighted a strong correlation between certain heterocycle concentrations and wine age. The second revealed a correlation between heterocyclic compound and free amino acid concentrations measured in the wines, suggesting that these compounds are potential aromatic precursors when wine is aged on lees and, thus, potential key compounds in the bouquet of aged Champagnes. The principal outcome of these assays was to reveal, for the first time, that aromatic heterocycle concentrations in Champagne base wines are correlated with wine age.

[New-type electrodeless excilamp for advanced treatment on nitrogen-heterocyclic compounds (NHCs) in aqueous solution].

Science.gov (United States)

Ye, Zhao-Lian; Wang, Bin; Lu, Juan-Juan; Li, Feng; Zhang, Ren-Xi

2012-03-01

A novel 206 nm excilamp generated by microwave-driven Kr/I2 mixtures was employed for nitrogen-heterocyclic compounds (NHCs) degradation in aqueous solution. The photodissociation efficiencies of indole and quinoline with 206 nm excilamp were estimated on the basis of removal efficiency of targeted compounds and the loss of total organic carbon (TOC). The results indicated that removal efficiency of 20 mg x L(-1) indole was as high as 62.0% after 80 min and TOC loss efficiency of 50.7% for 150 min. The irradiation time, initial concentration and pH value had some influences on quinoline degradation. Indole removal efficiency and TOC loss was markedly higher than that of quinoline under the same condition. The intermediates were identified qualitatively by gas chromatography/mass spectrum (GC/MS) with headspace sampling after they were extracted by rotary evaporator. GC/MS analysis indicated that indole and quinoline underwent ring-open dissociation under 206 nm irradiation, as a result, benzene, xylene, acetate, aldehyde, as well as ester compounds were formed, while indole aggregation reaction occurred during indole photodegradation. At last, degradation mechanisms of quinoline and indole in aqueous media with 206 nm excilamp were proposed on the basis of intermediates.

Dye-sensitized solar cell based on AZO/Ag/AZO multilayer transparent conductive oxide film

Energy Technology Data Exchange (ETDEWEB)

Qi, Jin-He; Li, Ying [School of Materials Science and Engineering, Shanghai University, 149 Yanchang Road, Shanghai 200072 (China); Duong, Thanh-Tung; Choi, Hyung-Jin [Department of Materials Engineering, Chungnam National University, Daeduk Science Town, 305-764 Daejeon (Korea, Republic of); Yoon, Soon-Gil, E-mail: sgyoon@cnu.ac.kr [Department of Materials Engineering, Chungnam National University, Daeduk Science Town, 305-764 Daejeon (Korea, Republic of)

2013-04-15

Highlights: ► AZO/Ag/AZO (AAA) multilayer was used for working electrode of DSSC cell. ► The 100 nm-thick Nb-doped TiO{sub 2} layer showed a good blocking effect. ► The DSSC cell by AAA TCO material showed the highest efficiency of about 3.25%. -- Abstract: Niobium-doped TiO{sub 2} blocking layer and Al-doped ZnO (AZO)/Ag/AZO (AAA) TCO layers were grown onto glass substrate using pulsed laser deposition (PLD) and direct current (dc)/radio-frequency (rf) sputtering at room temperature, respectively for dye-sensitized solar cell (DSSC) applications. The 100 nm-thick NTO layer showed a blocking effect for the oxygen diffusion into AAA layer and for the recombination of the electrons. The DSSC cell composed of the NTO (100 nm)/AAA (400 nm) showed the highest photo-electrical efficiency of about 3.25%. An insertion of aluminum foil between serrated clip and AAA (100 nm) TCO improved a photo-conversion efficiency of the DSSC.

Dye-sensitized solar cell based on AZO/Ag/AZO multilayer transparent conductive oxide film

International Nuclear Information System (INIS)

Qi, Jin-He; Li, Ying; Duong, Thanh-Tung; Choi, Hyung-Jin; Yoon, Soon-Gil

2013-01-01

Highlights: ► AZO/Ag/AZO (AAA) multilayer was used for working electrode of DSSC cell. ► The 100 nm-thick Nb-doped TiO 2 layer showed a good blocking effect. ► The DSSC cell by AAA TCO material showed the highest efficiency of about 3.25%. -- Abstract: Niobium-doped TiO 2 blocking layer and Al-doped ZnO (AZO)/Ag/AZO (AAA) TCO layers were grown onto glass substrate using pulsed laser deposition (PLD) and direct current (dc)/radio-frequency (rf) sputtering at room temperature, respectively for dye-sensitized solar cell (DSSC) applications. The 100 nm-thick NTO layer showed a blocking effect for the oxygen diffusion into AAA layer and for the recombination of the electrons. The DSSC cell composed of the NTO (100 nm)/AAA (400 nm) showed the highest photo-electrical efficiency of about 3.25%. An insertion of aluminum foil between serrated clip and AAA (100 nm) TCO improved a photo-conversion efficiency of the DSSC

AZO/Au/AZO tri-layer thin films for the very low resistivity transparent electrode applications

Energy Technology Data Exchange (ETDEWEB)

Chu, Chien-Hsun [Department of Materials Science and Engineering, National Cheng Kung University, Tainan 70101, Taiwan (China); Wu, Hung-Wei, E-mail: hwwu@mail.ksu.edu.tw [Department of Computer and Communication, Kun Shan University, Tainan 71003, Taiwan (China); Huang, Jow-Lay [Department of Materials Science and Engineering, National Cheng Kung University, Tainan 70101, Taiwan (China); Department of Chemical and Materials Engineering, National University of Kaohsiung, Kaohsiung 81148, Taiwan (China); Research Center for Energy Technology and Strategy, National Cheng Kung University, Tainan 70101, Taiwan (China)

2014-08-01

Highlights: • High-quality Al-doped ZnO (AZO)/Au/AZO transparent conducting oxide films. • AZO films (30 nm) made by RF sputtering; ion sputtering for Au film (5–20 nm). • Effects of Au thickness on optical and electrical properties were analyzed. • The resistivity of 9 × 10{sup −5} Ω cm and the transmittance of 86.2% of the multilayer films were obtained in this study. - Abstract: Aluminum-doped ZnO (AZO)/gold/AZO tri-layer structures with very low resistivity and high transmittance are prepared by simultaneous RF magnetron sputtering (for AZO) and ion sputtering (for Au). The properties of the tri-layer films are investigated at different Au layer thicknesses (5–20 nm). The effects of Au layer thickness and the role of Au on the transmission properties of the tri-layer films were investigated. The very low resistivity of 1.01 × 10{sup −5} Ω cm, mobility of 27.665 cm{sup 2} V{sup −1} s{sup −1}, and carrier concentration of 4.563 × 10{sup 22} cm{sup −3} were obtained at an Au layer thickness of 20 nm. The peak transmittance of 86.18% at 650-nm wavelength was obtained at an Au layer thickness of 8 nm. These results show the films to be a good candidate for high-quality electrode scheme in various display applications.

Mechanochemical synthesis and structural characterization of three novel cocrystals of dimethylglyoxime with N-heterocyclic aromatic compounds and acetamide

Science.gov (United States)

Abidi, Syed Sibte Asghar; Azim, Yasser; Gupta, Abhishek Kumar; Pradeep, Chullikkattil P.

2017-12-01

With an aim to explore the interactions of (RR'Cdbnd Nsbnd OH) oxime moiety of dimethylglyoxime (DMG) with pyridyl ring of N-heterocyclic aromatic compounds and acetamide, three novel cocrystals of dimethylglyoxime with acridine (ACR), 1,10-phenanthroline monohydrate (PT) and acetamide (ACT) are reported. These three cocrystals were obtained with a mechanochemical synthesis approach and were characterized by single crystal X-ray diffraction (SCXRD), powder X-ray diffraction (PXRD), fourier transform-infrared spectroscopy (FT-IR), differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). Additionally, Hirshfeld surface analysis is used to investigate the intermolecular interaction and the crystal packing of cocrystals.

Structural and optical properties of ZnO nanostructures electrochemically synthesized on AZO/Ag/AZO-multilayer-film-coated polyethersulfone substrates

International Nuclear Information System (INIS)

Oh, Dohyun; Yoo, Chanho; No, Youngsoo; Kim, Suyoun; Kim, Taewhan; Cho, Woonjo; Kim, Jinyoung

2012-01-01

ZnO nanostructures were formed on Al-doped ZnO (AZO)/Ag/AZO-multilayer-film-coated flexible polyethersulfone (PES) substrates at low temperature by using an electrochemical deposition method. The resistivity of the AZO/Ag/AZO multilayer films decreased with increasing thickness of the Ag film. X-ray diffraction patterns for the ZnO nanostructures showed that the crystal structure of the ZnO was hexagonal wurtzite and that the orientation was along the c-axis perpendicular to the substrate. Scanning electron microscopy images showed that the ZnO nanostructures grown at current densities of - 1.0 and - 1.5 mA/cm 2 were ZnO nanorods with diameters of 150 nm and ZnO nanoflowers with a planar dimension, respectively. Photoluminescence spectra showed that the band-edge emission peak of the ZnO nanostructures dominantly appeared in the ultraviolet region. These results showed that ZnO nanorods and nanoflowers with high quality were synthesized on AZO/Ag/AZO-multilayer-film-coated PES substrates.

Degradation of azo dyes by environmental microorganisms and helminths

Energy Technology Data Exchange (ETDEWEB)

Kingthom Chung; Stevens, S.E. Jr. (Memphis State Univ., TN (United States). Dept. of Biology)

1993-11-01

The degradation of azo dyes by environmental microorganisms, fungi, and helminths is reviewed. Azo dyes are used in a wide variety of products and can be found in the effluent of most sewage treatment facilities. Substantial quantities of these dyes have been deposited in the environment, particularly in streams and rivers. Azo dyes were shown to affect microbial activities and microbial population sizes in the sediments and in the water columns of aquatic habitats. Only a few aerobic bacteria have been found to reduce azo dyes under aerobic conditions, and little is known about the process. A substantial number of anaerobic bacteria capable of azo dye reduction have been reported. The enzyme responsible for azo dye reduction has been partially purified, and characterization of the enzyme is proceeding. The nematode Ascaris lumbricoides and the cestode Moniezia expanza have been reported to reduce azo dyes anaerobically. Recently the fungus Phanerochaete chrysoporium was reported to mineralize azo dyes via a peroxidation-mediated pathway. A possible degradation pathway for the mineralization of azo dye is proposed and future research needs are discussed.

The structural and electro-optical characteristics of AZO/Cr:Cu/AZO transparent conductive film

International Nuclear Information System (INIS)

Lin, Tien-Chai; Huang, Wen-Chang; Tsai, Fu-Chun

2015-01-01

A novel triple-layered transparent conductive film, AZO/Cr:Cu/AZO (ACCA), was presented in the paper. The structural and electro-optical properties of the ACCA film were discussed. The thickness of the middle metal layer was constant and those of the AZO layers were varied. The ACCA film shows an obvious ZnO (002) c-axis preferential growth. No diffraction peaks related to Cr and Cu were observed through x-ray diffraction analysis. The middle Cr:Cu layer showed a thickness of 8.16 nm with a continuous and amorphous structure by the observation of a high-resolution transmission electron microscopy (HR-TEM). For the electro-optical characteristic, a best figure of merit (FOM) value of 3.54 × 10 −3 Ω −1 with a corresponding transmittance of 85% was obtained at the thickness of 116 nm of ACCA film. The high FOM value of the film is due to the improvement of conductivity and small sacrifices of transparency. - Highlights: • A novel triple-layered transparent conductive film, AZO/Cr:Cu/AZO is developed. • Chromium is added to copper to reduce the oxidation–reduction reaction. • The film has a FOM of 3.54 × 10 −3 Ω −1 with a corresponding transmittance of 85%. • The Cr:Cu layer shows a continuous and amorphous structure

The structural and electro-optical characteristics of AZO/Cr:Cu/AZO transparent conductive film

Energy Technology Data Exchange (ETDEWEB)

Lin, Tien-Chai [Department of Electrical Engineering, Kun Shan University, No. 195, Kun-Da Road, Yung-Kang Dist., Tainan 71003, Taiwan, ROC (China); Huang, Wen-Chang, E-mail: wchuang@mail.ksu.edu.tw [Department of Electro-Optical Engineering, Kun Shan University, No. 195, Kun-Da Road, Yung-Kang Dist., Tainan 71003, Taiwan, ROC (China); Tsai, Fu-Chun [Department of Electro-Optical Engineering, Kun Shan University, No. 195, Kun-Da Road, Yung-Kang Dist., Tainan 71003, Taiwan, ROC (China)

2015-08-31

A novel triple-layered transparent conductive film, AZO/Cr:Cu/AZO (ACCA), was presented in the paper. The structural and electro-optical properties of the ACCA film were discussed. The thickness of the middle metal layer was constant and those of the AZO layers were varied. The ACCA film shows an obvious ZnO (002) c-axis preferential growth. No diffraction peaks related to Cr and Cu were observed through x-ray diffraction analysis. The middle Cr:Cu layer showed a thickness of 8.16 nm with a continuous and amorphous structure by the observation of a high-resolution transmission electron microscopy (HR-TEM). For the electro-optical characteristic, a best figure of merit (FOM) value of 3.54 × 10{sup −3} Ω{sup −1} with a corresponding transmittance of 85% was obtained at the thickness of 116 nm of ACCA film. The high FOM value of the film is due to the improvement of conductivity and small sacrifices of transparency. - Highlights: • A novel triple-layered transparent conductive film, AZO/Cr:Cu/AZO is developed. • Chromium is added to copper to reduce the oxidation–reduction reaction. • The film has a FOM of 3.54 × 10{sup −3} Ω{sup −1} with a corresponding transmittance of 85%. • The Cr:Cu layer shows a continuous and amorphous structure.

Identification of sulfur heterocycles in coal liquids and shale oils. Technical progress report, August 1, 1980-May 1, 1981

Energy Technology Data Exchange (ETDEWEB)

Lee, M. L.; Castle, R. N.

1981-01-01

The sulfur heterocycle separation scheme which was described in the last progress report was evaluated for quantitative recovery of individual components. The results indicate that recoveries can range from 10% to approx. 30% depending on the structure of the compound. During this period, 23 unsubstituted sulfur-containing heterocyclic ring systems were synthesized in oder to confirm GC/MS identifications and for biological testing. The four possible 3-ring heterocycles and the thirteen possible 4-ring heterocycles were tested for mutagenic activity in the histidine reversion (Ames assay) system. One of the 3-ring isomers, naphtho(1,2-b)-thiophene, and six of the 4-ring isomers induced mutations in Salmonella test strains. One of these compounds, phenanthro(3,4-b)thiophene, displayed approximately the same mutagenic activity as benzo(a)pyrene. A two-step adsorption chromatographic procedure was developed in order to fractionate synthetic fuels into various chemical-type classes for studying the relative concentrations and mutagenic activities of the various types. An SRC-II Heavy Distillate was fractionated into aliphatic hydrocarbons, polycyclic aromatic hydrocarbons, sulfur heterocycles, indoles and carbazoles, azaarenes, and amino polycyclic aromatic hydrocarbons. It was found that the amino-PAH fraction contained most of the mutagenic activity. A survey was made for compounds containing both nitrogen and sulfur heteroatoms in their structures. A number of these compounds were detected by GC using nitrogen- and sulfur-selective detection.

Electrical circuit model of ITO/AZO/Ge photodetector.

Science.gov (United States)

Patel, Malkeshkumar; Kim, Joondong

2017-10-01

In this data article, ITO/AZO/Ge photodetector was investigated for electrical circuit model. Due to the double (ITO and AZO) transparent metal-oxide films (DOI:10.1016/j.mssp.2016.03.007) (Yun et al., 2016) [1], the Ge heterojunction device has a better interface quality due to the AZO layer with a low electrical resistance due to the ITO layer (Yun et al., 2015) [2]. The electrical and interfacial benefitted ITO/AZO/Ge heterojunction shows the quality Schottky junction. In order to investigate the device, the ITO/AZO/Ge heterojunction was analyzed by R-C circuit model using the impedance spectroscopy.

A simple, convenient, and one pot synthetic route for the preparation of 1,3,5-thiadiazines-2-thione heterocyclic compounds and their antifungal activity

Directory of Open Access Journals (Sweden)

Sohail Saeed

2015-12-01

Full Text Available A series of new heterocyclic 1,3,5-thiadiazines-2-thione with aroyl/aryl substituents (3a-c were synthesized by reacting isothiocyanates with N- (propan-2-ylpropan-2- amine in the presence of tetrabutylammonium bromide as phase transfer catalyst. The structures of these novel compounds were characterized by IR, mass spectrometry, and elemental analysis. The crystal structures were determined from single-crystal X-ray diffraction data. The synthesized compounds were tested in vitro against Fusarium solani, A. fumigatus, and Aspergillus flavus using standard drugs.

Some heterocyclic aromatic compounds are Ah receptor agonists in the DR-CALUX assay and the EROD assay with RTL-W1 cells.

Science.gov (United States)

Hinger, Gunnar; Brinkmann, Markus; Bluhm, Kerstin; Sagner, Anne; Takner, Helena; Eisenträger, Adolf; Braunbeck, Thomas; Engwall, Magnus; Tiehm, Andreas; Hollert, Henner

2011-09-01

Heterocyclic aromatic compounds containing nitrogen, sulfur, or oxygen heteroatoms (NSO-HET) have been detected in air, soil, marine, and freshwater systems. However, only few publications are available investigating NSO-HET using in vitro bioassays. To support better characterization of environmental samples, selected NSO-HET were screened for dioxin-like activity in two bioassays. The present study focuses on the identification and quantification of dioxin-like effects of 12 NSO-HET using the DR-CALUX assay, and the 7-ethoxyresorufin-O-deethylase (EROD) assay with the permanent fish liver cell line RTL-W1. Changes of the total medium compound concentrations during the test procedure due to, e.g., sorption or volatilization were quantified using GC/MS. The NSO-HET benzofuran, 2,3-dimethylbenzofuran, dibenzofuran, dibenzothiophen, acridine, xanthene, and carbazole caused a response in the DR-CALUX assay. Only benzofuran and 2,3-dimethylbenzofuran were also positive in the EROD assay. All other compounds were inactive in the EROD assay. Relative potency (REP) values ranged from (2.80 ± 1.32) · 10(-8) to (3.26 ± 2.03) · 10(-6) in the DR-CALUX and from (3.26 ± 0.91) · 10(-7) to (4.87 ± 1.97) · 10(-7) in the EROD assay. The REP values were comparable to those of larger polycyclic aromatic hydrocarbons, e.g., fluoranthene and pyrene. Thus, and because of the ubiquitous distribution of heterocyclic aromatic compounds in the environment, the provided data will further facilitate the bioanalytical and analytical characterization of environmental samples towards these toxicants.

Pyridine group assisted addition of diazo-compounds to imines in the 3-CC reaction of 2-aminopyridines, aldehydes, and diazo-compounds.

Science.gov (United States)

Gulevich, Anton V; Helan, Victoria; Wink, Donald J; Gevorgyan, Vladimir

2013-02-15

A novel three-component coupling (3-CC) reaction of 2-aminoazines, aromatic aldehydes, and diazo-compounds producing polyfunctional β-amino-α-diazo-compounds has been developed. The reaction features an unprecedented heterocycle-assisted addition of a diazo-compound to an imine. The obtained diazoesters were efficiently converted into valuable heterocycles as well as β-amino acid derivatives.

Electrical circuit model of ITO/AZO/Ge photodetector

Directory of Open Access Journals (Sweden)

Malkeshkumar Patel

2017-10-01

Full Text Available In this data article, ITO/AZO/Ge photodetector was investigated for electrical circuit model. Due to the double (ITO and AZO transparent metal-oxide films (DOI:10.1016/j.mssp.2016.03.007 (Yun et al., 2016 [1], the Ge heterojunction device has a better interface quality due to the AZO layer with a low electrical resistance due to the ITO layer (Yun et al., 2015 [2]. The electrical and interfacial benefitted ITO/AZO/Ge heterojunction shows the quality Schottky junction. In order to investigate the device, the ITO/AZO/Ge heterojunction was analyzed by R–C circuit model using the impedance spectroscopy.

Electric conduction mechanism of some heterocyclic compounds, 4,4′-bipyridine and indolizine derivatives in thin films

Energy Technology Data Exchange (ETDEWEB)

Danac, Ramona, E-mail: rdanac@uaic.ro [Faculty of Chemistry, Alexandru Ioan Cuza University of Iasi, Bulevardul Carol I, Nr. 11, 700506 Iasi (Romania); Leontie, Liviu, E-mail: lleontie@uaic.ro [Faculty of Physics, Alexandru Ioan Cuza University of Iasi, Bulevardul Carol I, Nr. 11, 700506 Iasi (Romania); Carlescu, Aurelian, E-mail: carlescu_aurelian@yahoo.com [Faculty of Physics, Alexandru Ioan Cuza University of Iasi, Bulevardul Carol I, Nr. 11, 700506 Iasi (Romania); Shova, Sergiu, E-mail: shova@icmpp.ro [Petru Poni Institute of Macromolecular Chemistry, Aleea Grigore Ghica Voda, Nr. 41A, 700487 Iasi (Romania); Tiron, Vasile, E-mail: vasile.tiron@uaic.ro [Faculty of Physics, Alexandru Ioan Cuza University of Iasi, Bulevardul Carol I, Nr. 11, 700506 Iasi (Romania); Rusu, George G., E-mail: rusugxg@uaic.ro [Faculty of Physics, Alexandru Ioan Cuza University of Iasi, Bulevardul Carol I, Nr. 11, 700506 Iasi (Romania); Iacomi, Felicia, E-mail: iacomi@uaic.ro [Faculty of Physics, Alexandru Ioan Cuza University of Iasi, Bulevardul Carol I, Nr. 11, 700506 Iasi (Romania); Gurlui, Silviu, E-mail: sgurlui@uaic.ro [Faculty of Physics, Alexandru Ioan Cuza University of Iasi, Bulevardul Carol I, Nr. 11, 700506 Iasi (Romania); Șușu, Oana, E-mail: oasusu@gmail.com [Faculty of Physics, Alexandru Ioan Cuza University of Iasi, Bulevardul Carol I, Nr. 11, 700506 Iasi (Romania); Rusu, Gheorghe I., E-mail: girusu@uaic.ro [Faculty of Physics, Alexandru Ioan Cuza University of Iasi, Bulevardul Carol I, Nr. 11, 700506 Iasi (Romania)

2016-08-01

Temperature dependence of d. c. electric conductivity of some recently synthesized heterocyclic compounds, 4,4′-bipyridine and indolizine derivatives, in thin films (d = 0.27–0.51 μm) spin-coated from chloroform solutions onto glass, is studied. The investigated compounds are polycrystalline (as shown by X-ray Diffraction analysis) and show typical n-type semiconductor behavior. The activation energy of d. c. electric conduction ranges between 1.55 and 2.33 eV. Some correlations between semiconducting characteristics and essential features of molecular structure of organic compounds have been established. In the higher temperature range (400–520 K), the electronic transport properties in present compounds can be explained in the frame of band gap representation model, while in the lower temperature range (300–350 K), the Mott's variable-range hopping conduction model can be conveniently used. - Highlights: • 4,4′-bipyridine and indolizine derivatives in thin films behave as n-type semiconductors. • The electron transfer is favored by extended conjugation and packing capacity. • The band gap representation is suitable in the higher temperature range. • The Mott's VRH conduction model may be used in the lower temperature range.

Enaminone in heterocyclic synthesis: synthesis of new pyrazolopyrazole, pyrazolothienooxazine and pyrazolothienopyridine derivatives

International Nuclear Information System (INIS)

Hafiz, I.S.; Rahim, M.A.M.A.

2014-01-01

The chemical reactivity of enaminone 2 toward some nucleophilic and electrophilic reagents was investigated. Enaminone 2 was used as a key precursor for the synthesis of many important heterocyclic compounds. The synthesized compounds were characterized by IR, 1H-NMR, MS spectral and elemental analysis. (author)

Alkoxy(alkyl)silylalkyl derivatives of nitrogen-containing heterocycles

International Nuclear Information System (INIS)

Trofimova, Ol'ga M; Voronkov, Mikhail G; Chernov, Nikolai F

1999-01-01

The published data on the synthesis, properties and transformations of alkoxy(alkyl)silylalkyl derivatives of nitrogen-containing heterocycles of the general formula Het(CH 2 ) n SiX 3 are surveyed and systematised. Data on the biological activities and applications of these compounds are presented. The bibliography includes 255 references.

Pyridine Group-Assisted Addition of Diazo-Compounds to Imines in the 3-CC Reaction of 2-Aminopyridines, Aldehydes, and Diazo-Compounds

Science.gov (United States)

Gulevich, Anton V.; Helan, Victoria; Wink, Donald J.

2013-01-01

A novel three-component (3-CC) coupling reaction of 2-aminoazines, aromatic aldehydes and diazo-compounds producing polyfunctional β-amino-α-diazo-compounds has been developed. The reaction features an unprecedented heterocycle-assisted addition of a diazo-compound to an imine. The obtained diazoesters were efficiently converted into valuable heterocycles, as well as to β-amino acid derivatives. PMID:23373731

Synthesis, pharmacological activity evaluation and molecular modeling of new polynuclear heterocyclic compounds containing benzimidazole derivatives.

Science.gov (United States)

Bassyouni, Fatma A; Saleh, Tamer S; ElHefnawi, Mahmoud M; Abd El-Moez, Sherein I; El-Senousy, Waled M; Abdel-Rehim, Mohamed E

2012-12-01

Novel heterocyclic compounds containing benzimidazole derivatives were synthesized from 2-(1H-benzimidazol-2-yl) acetonitrile (1) and arylhydrazononitrile derivative 2 was obtained via coupling of 1 with 4-methyl phenyldiazonium salt, which was then reacted with hydroxylamine hydrochloride to give amidooxime derivative 3. This product was cyclized into the corresponding oxadiazole derivative 4 upon reflux in acetic anhydride. Compound 4 was refluxed in DMF in the presence of triethylamine to give the corresponding 5-(1H-benzimidazol-2-yl)-2-p-tolyl-2H-1,2,3-triazol-4-amine 6. Treatment of compound 6 with ethyl chloroformate afforded 2,6-dihydro-2-(4-methylphenyl)-1,2,3-triazolo[4",5"-4',5']pyrimido[1,6-a]benzimidazole-5(4H)-one (8). 1,2-bis(2-cyanomethyl-1H-benzimidazol-1-yl)ethane-1,2-dione (10) was synthesized via the condensation reaction of 2-(1H-benzimidazol-2-yl) acetonitrile (1) and diethyloxalate. The reactivity of compound 10 towards some diamine reagents was studied. The in vitro antimicrobial activity of the synthesized compounds was investigated against several pathogenic bacterial strains such as Escherichia coli O157, Salmonella typhimurium, E. coli O119, S. paratyphi, Pseudomonas aeruginosa, Staphylococcus aureus, Listeria monocytogenes and Bacillus cereus. The results of MIC revealed that compounds 12a-c showed the most effective antimicrobial activity against tested strains. On the other hand, compounds 12a, b exhibited high activity against rotavirus Wa strain while compounds 12b, c exhibited high activity against adenovirus type 7. In silico target prediction, docking and validation of the compounds 12a-c were performed. The dialkylglycine decarboxylase bacterial enzyme was predicted as a potential bacterial target receptor using pharmacophore-based correspondence with previous leads; giving the highest normalized scores and a high correlation docking score with mean inhibition concentrations. A novel binding mechanism was predicted after docking

Greener Alternatives to Expedient Synthesis of Heterocycles and Nanomaterial

Science.gov (United States)

A brief account of reactions involving microwave (MW) exposure of neat reactants or catalyzed by mineral support surfaces, such as alumina, silica, clay, or their ‘doped’ versions, for the rapid one-pot assembly of heterocyclic compounds [1] from in situ generated reactive interm...

Facile synthesis and antimicrobial evaluation of some new heterocyclic compounds incorporating a biologically active sulfamoyl moiety.

Science.gov (United States)

Darwish, Elham S

2014-01-01

A facile and convenient synthesis of new heterocyclic compounds containing a sulfamoyl moiety suitable for use as antimicrobial agents was reported. The precursor 3-oxo-3-phenyl-N-(4-sulfamoylphenyl)propionamide was coupled smoothly with arenediazonium salt producing hydrazones which reacted with malononitrile or triethylorthoformate affording pyridazine and triazine derivatives, respectively. Also, the reactivity of the same precursor with DMF-DMA was followed by aminotriazole; aromatic aldehydes was followed by hydrazine hydrate, triethylorthoformate, or thiourea affording triazolo[1,5-a]pyrimidine, pyrazole, acrylamide, and dihydropyrimidine derivatives, respectively. On the other hand, treatment of the precursor propionamide with phenyl isothiocyanate and KOH in DMF afforded the intermediate salt which was treated with dilute HCl followed by 2-bromo-1-phenylethanone affording carboxamide derivative. While the same intermediate salt reacted in situ with chloroacetone, ethyl 2-chloroacetate, 3-(2-bromoacetyl)-2H-chromen-2-one, methyl iodide, or 2-oxo-N-phenylpropane hydrazonoyl chloride afforded the thiophene, ketene N,S-acetal, and thiadiazole derivatives, respectively. The structure of the new products was established based on elemental and spectral analysis. Antimicrobial evaluation of some selected examples from the synthesized products was carried out whereby four compounds were found to have moderate activities and one compound showed the highest activity.

Lactoperoxidase, an Antimicrobial Milk Protein, as a Potential Activator of Carcinogenic Heterocyclic Amines in Breast Cancer.

Science.gov (United States)

Sheikh, Ishfaq Ahmad; Jiffri, Essam Hussain; Kamal, Mohammad Amjad; Ashraf, Ghulam Md; Beg, Mohd Amin

2017-11-01

Lactoperoxidase (LPO) is an antimicrobial protein secreted from mammary, salivary and other mucosal glands. It is an important member of heme peroxidase enzymes and the primary peroxidase enzyme present in breast tissues. In addition to the antimicrobial properties, LPO has been shown to be associated with breast cancer etiology. Heterocyclic amines, an important class of environmental and dietary carcinogens, have been increasingly associated with breast cancer etiology. Heterocyclic amines undergo activation in breast tissue as a result of oxidation by LPO. The current study includes three important heterocyclic amines, 2-amino-3-methylimidazo[4,5-f]quinoline (IQ), 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx) and 2-amino-1-methy-6-phenylimidazo[4,5-b]-pyridine (PhIP), that have carcinogenic activity. The structural binding characterization of IQ, MeIQx and PhIP with LPO was done using in silico approaches. Their binding pattern and interactions with LPO amino acid residues were analyzed. The three compounds bound in the distal heme cavity of LPO without replacing the important water molecule required for oxidation of substrate compounds. PhIP displayed lesser binding affinity for LPO in comparison to IQ and MeIQx. The binding mode of heterocyclic amines in distal heme cavity of LPO resembled to that of substrate binding pattern. The three heterocyclic amines are suggested to act as LPO substrate. The undisturbed water molecule present in distal heme cavity of the LPO is expected to facilitate the oxidation and activation of the three heterocyclic amines. These activated compounds may potentially bind with DNA in breast tissues forming DNA adducts and may subsequently lead to breast cancer initiation. Copyright© 2017, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

Evidence for significantly enhancing reduction of Azo dyes in Escherichia coli by expressed cytoplasmic Azoreductase (AzoA) of Enterococcus faecalis.

Science.gov (United States)

Feng, J; Heinze, T M; Xu, H; Cerniglia, C E; Chen, H

2010-05-01

Although cytoplasmic azoreductases have been purified and characterized from various bacteria, little evidence demonstrating that these azoreductases are directly involved in azo dye reduction in vivo is known. In order to evaluate the contribution of the enzyme to azo dye reduction in vivo, experiments were conducted to determine the effect of a recombinant cytoplasmic azoreductase (AzoA) from Enterococcus faecalis expressed in Escherichia coli on the rate of metabolism of Methyl Red, Ponceau BS and Orange II. The intact cells that contained IPTG induced AzoA had a higher rate of dye reduction with increases of 2 (Methyl Red), 4 (Ponceau BS) and 2.6 (Orange II)-fold compared to noninduced cells, respectively. Metabolites of Methyl Red isolated from induced cultures were identified as N,N-dimethyl-p-phenylenediamine and 2-aminobenzoic acid through liquid chromatography electrospray ionization tandem mass spectrometry (LC/ESI-MS/MS) analyses. In conclusion, our data demonstrate that AzoA from Ent. faecalis is capable of increasing the reduction of azo dyes in intact E. coli cells and that cytoplasmic azoreductase is involved in bacterial dye degradation in vivo.

The Hydractinia echinata Test-System. III: Structure-Toxicity Relationship Study of Some Azo-, Azo-Anilide, and Diazonium Salt Derivatives

Directory of Open Access Journals (Sweden)

Sergiu Adrian Chicu

2014-07-01

Full Text Available Structure-toxicity relationships for a series of 75 azo and azo-anilide dyes and five diazonium salts were developed using Hydractinia echinata (H. echinata as model species. In addition, based on these relationships, predictions for 58 other azo-dyes were made. The experimental results showed that the measured effectiveness Mlog(1/MRC50 does not depend on the number of azo groups or the ones corresponding to metobolites, but it is influenced by the number of anilide groups, as well as by the substituents’ positions within molecules. The conformational analysis pointed out the intramolecular hydrogen bonds, especially the simple tautomerization of quinoidic (STOH or aminoidic (STNH2 type. The effectiveness is strongly influenced by the “push-pull” electronic effect, specific to two hydroxy or amino groups separated by an azo moiety (double alternate tautomery, (DAT, to the –COOH or –SO3H groups which are located in ortho or para position with respect to the azo group. The levels of the lipophylic/hydrophilic, electronic and steric equilibriums, pointed out by the Mlog(1/MRC50 values, enabled the calculation of their average values Clog(1/MRC50 (“Köln model”, characteristic to one derivative class (class isotoxicity. The azo group reduction and the hydrolysis of the amido/peptidic group are two concurrent enzymatic reactions, which occur with different reaction rates and mechanisms. The products of the partial biodegradation are aromatic amines. No additive or synergic effects are noticed among them.

Synthesis and properties of nitrogenous heterocycles containing a spiro-fused cyclopropane fragment

International Nuclear Information System (INIS)

Tomilov, Yury V; Nefedov, Oleg M; Kostyuchenko, Irina V

2000-01-01

The published data on the methods of synthesis and chemical transformations of nitrogenous heterocyclic compounds spiro-fused with a cyclopropane fragment are described systematically and generalised. The bibliography includes 146 references.

Role of certain plant natural products or gamma radiation in the control of mutagenic activity of some heterocyclic amines

International Nuclear Information System (INIS)

Abu Ghadeer, A.R.M.; El-Sedeek, A.B.A.; Salem, A.M.; Abu Zaid, M.M.

1999-01-01

The present study was designed to use ames test to evaluate the antimutagenic effect of some natural products on the lever microsomes extracted from rats and incubated with some chemical mutagens (heterocyclic compounds). Male swiss albino rats (120-140 g) were used as the source of liver microsomes. Three natural products (Nigella extract, garlic powder and sesame oil) were used to evaluate their antimutagenic activities on six heterocyclic amines. All the tested natural products exhibited their antimutagenic activities when added to the investigated heterocyclic compounds and the most effective product was nigella sativa. another group of rats was exposed to gamma-radiation (6.5 Gy) for testing the validity of ames test in quantitating mutagenicity using liver microsomes of irradiated rats. Liver microsomes from irradiated rats showed to lose ability for metabolic activation needed for heterocyclic amines to exert their mutagenic effect on salmonella typhimurium

Bent Shaped 1,3,4-Oxadiazole/Thiadiazole heterocyclic rings ...

Indian Academy of Sciences (India)

Two series of bent shaped 1,3,4-oxadiazole/thiadiazole heterocyclic ring containing liquid crystalline (LC) compounds were synthesized and characterized by FT-IR, 1H, 13C-NMR and ESI-Mass spectro-scopic techniques. Liquid crystal properties were investigated by polarized optical microscopy and differential scanning ...

Antimicrobial azobenzene compounds and their potential use in biomaterials

Science.gov (United States)

Sessa, L.; Concilio, S.; Iannelli, P.; De Santis, F.; Porta, A.; Piotto, S.

2016-04-01

We recently synthesized a class of active compounds with azobenzene structure [1] and lowest in silico toxicity values. The antimicrobial activity of these molecules and their thermal stability are very promising and indicate that they may have interesting and therapeutically significant applications. This work aims to develop new materials with antibacterial and antifungal activity inserting different percentages of synthetic antimicrobial azo compounds in commercial polymer matrices. We realized thin films using solvent casting and melt compounding techniques. The obtained materials retained the proprieties of the pure matrices. This means that azo dye dissolved in the matrix does not influence the thermal behavior and the morphology of the material. Tested films exhibited the capability to inhibit biofilms formation of S. aureus and C. albicans. Spectrophotometric investigation of the azo compound released from the polymer matrices confirmed that the realized materials might be interesting for biomedical tools, antibacterial surfaces, and films for active packaging.

Aerobic decolourization of two reactive azo dyes under varying ...

African Journals Online (AJOL)

STORAGESEVER

2010-02-01

Feb 1, 2010 ... Azo dyes generally resist aerobic microbial degra- dation, only organisms with specialized azo dye reducing enzymes were found to degrade azo dyes under fully aerobic ... textile mill, in sterile plastic bottles. Isolation of ...

Recent advances in novel heterocyclic scaffolds for the treatment of drug-resistant malaria.

Science.gov (United States)

Kumar, Sahil; Singh, Rajesh K; Patial, Babita; Goyal, Sachin; Bhardwaj, T R

2016-01-01

Malaria is a major public health problem all over the world, particularly in tropical and subtropical countries due to the development of resistance and most deadly infection is caused by Plasmodium falciparum. There is a direct need for the discovery of new drugs with unique structures and mechanism of action to treat sensitive and drug-resistant strains of various plasmodia for radical cure of this disease. Traditional compounds such as quinine and related derivatives represent a major source for the development of new drugs. This review presents recent modifications of 4-aminoquinoline and 8-aminoquinolone rings as leads to novel active molecules which are under clinical trials. The review also encompasses the other heterocyclic compounds emerged as potential antimalarial agents with promising results such as acridinediones and acridinone analogues, pyridines and quinolones as antimalarials. Miscellaneous heterocyclics such as tetroxane derivatives, indole derivatives, imidazolopiperazine derivatives, biscationic choline-based compounds and polymer-linked combined antimalarial drugs are also discussed. At last brief introduction to heterocyclics in natural products is also reviewed. Most of them have been under clinical trials and found to be promising in the treatment of drug-resistant strains of Plasmodium and others can be explored for the same purpose.

Density functional theory study of adsorption geometries and electronic structures of azo-dye-based molecules on anatase TiO2 surface for dye-sensitized solar cell applications.

Science.gov (United States)

Prajongtat, Pongthep; Suramitr, Songwut; Nokbin, Somkiat; Nakajima, Koichi; Mitsuke, Koichiro; Hannongbua, Supa

2017-09-01

Structural and electronic properties of eight isolated azo dyes (ArNNAr', where Ar and Ar' denote the aryl groups containing benzene and naphthalene skeletons, respectively) were investigated by density functional theory (DFT) based on the B3LYP/6-31G(d,p) and TD-B3LYP/6-311G(d,p) methods The effect of methanol solvent on the structural and electronic properties of the azo dyes was elucidated by employing a polarizable continuum model (PCM). Then, the azo dyes adsorbed onto the anatase TiO 2 (101) slab surface through a carboxyl group. The geometries and electronic structures of the adsorption complexes were determined using periodic DFT based on the PWC/DNP method. The calculated adsorption energies indicate that the adsorbed dyes preferentially take configuration of the bidentate bridging rather than chelating or monodentate ester-type geometries. Furthermore, the azo compounds having two carboxyl groups are coordinated to the TiO 2 surface more preferentially through the carboxyl group connecting to the benzene skeleton than through that connecting to the naphthalene skeleton. The dihedral angles (Φ B-N ) between the benzene- and naphthalene-skeleton moieties are smaller than 10° for the adsorbed azo compounds containing one carboxyl group. In contrast, Φ B-N > 30° are obtained for the adsorbed azo compounds containing two carboxyl groups. The almost planar conformations of the former appear to strengthen both π-electrons conjugation and electronic coupling between low-lying unoccupied molecular orbitals of the azo dyes and the conduction band of TiO 2 . On the other hand, such coupling is very weak for the latter, leading to a shift of the Fermi level of TiO 2 in the lower-energy direction. The obtained results are useful to the design and synthesize novel azo-dye-based molecules that give rise to higher photovoltaic performances of the dye-sensitized solar cells. Copyright © 2017 Elsevier Inc. All rights reserved.

Characterization of AZO and Ag based films prepared by RF magnetron sputtering

International Nuclear Information System (INIS)

Miao, Dagang; Jiang, Shouxiang; Zhao, Hongmei; Shang, Songmin; Chen, Zhuoming

2014-01-01

Highlights: • Highly infrared reflective AZO and Ag based films were prepared. • Ag showed better crystallization on AZO film than on glass substrate. • Infrared reflection rate was inversely proportional to the film sheet resistance. • Film with infrared reflection of 97% in FIR region was acquired. - Abstract: Ag, AZO/Ag, Ag/AZO and AZO/Ag/AZO films were prepared on glass substrates by radio frequency (RF) magnetron sputtering technology. The prepared films were systematically investigated by X-ray Diffraction (XRD), Atomic Force Microscopy (AFM), UV–visible spectrophotometer, a four-point probe system and Fourier Transform Infrared Spectroscopy. The results indicated that Ag inner layer starts forming a continuous film at the thickness of 10 nm and Ag layer presents superior crystallization on AZO substrate than that on glass substrate. The continuous Ag inner layer film provided the highest average visible transmittance of 85.4% (AZO/Ag/AZO). The lowest sheet resistance of 3.21 Ω/sq and the highest infrared reflection rate of 97% in FIR region can be obtained on AZO/Ag (15 nm)/AZO film. The high infrared reflection property of the AZO/Ag/AZO coating makes it a promising candidate for solar control films

Design and Synthesis of Novel Antimicrobial Acyclic and Heterocyclic Dyes and Their Precursors for Dyeing and/or Textile Finishing Based on 2-N-Acylamino-4,5,6,7-tetrahydro-benzo[b]thiophene Systems

Directory of Open Access Journals (Sweden)

Rafat Milad Mohareb

2011-07-01

Full Text Available A series of novel polyfunctionalized acyclic and heterocyclic dye precursors and their respective azo (hydrazone counterpart dyes and dye precursors based on conjugate enaminones and/or enaminonitrile moieties were synthesized. The dyes and their precursors are based on 2-cyano-N-(3-cyano-4,5,6,7-tetrahydrobenzo[b]thiophen-2-yl-acetamide, 2-ethoxycarbonyl-N-(3-cyano-4,5,6,7-tetrahydrobenzo[b]thiophen-2-yl-acetamide or 2-phenylcarbamoyl-N-(3-cyano-4,5,6,7-tetrahydrobenzo[b]thiophen-2-yl-acetamide systems as precursors. The latter compounds were used to synthesize polyfunctional thiophene-, thiazole-, pyrazole, pyridine-, pyrimidine-, oxazine-, as well as acyclic moieties. The dyes and dye precursors were characterized by elemental analysis and spectral methods. All dyes and their precursors were screened in vitro and evaluated for both their antibacterial and antifungal activities. MIC data of the novel dye systems and their respective precursors showed significant antimicrobial activity against most tested organisms. Some compounds exhibited comparable or even higher efficiency than selected standards. Dyes were applied at 5% depth for disperse dyeing of nylon, acetate and polyester fabrics. Their spectral characteristics and fastness properties were measured and evaluated.

Comparison of carrier transport mechanism under UV/Vis illumination in an AZO photodetector and an AZO/p-Si heterojunction photodiode produced by spray pyrolysis

International Nuclear Information System (INIS)

Shasti, M.; Mortezaali, A.; Dariani, R. S.

2015-01-01

In this study, Aluminum doped Zinc Oxide (AZO) layer is deposited on p-type silicon (p-Si) by spray pyrolysis method to fabricate ultraviolet-visible (UV/Vis) photodetector as Al doping process can have positive effect on the photodetector performance. Morphology, crystalline structure, and Al concentration of AZO layer are investigated by SEM, XRD, and EDX. The goal of this study is to analyze the mechanism of carrier transport by means of current-voltage characteristics under UV/Vis illumination in two cases: (a) electrodes connected to the surface of AZO layer and (b) electrodes connected to cross section of heterojunction (AZO/p-Si). Measurements indicate that the AZO/p-Si photodiode exhibits a higher photocurrent and lower photoresponse time under visible illumination with respect to AZO photodetector; while under UV illumination, the above result is inversed. Besides, the internal junction field of AZO/p-Si heterojunction plays an important role on this mechanism

Comparison of carrier transport mechanism under UV/Vis illumination in an AZO photodetector and an AZO/p-Si heterojunction photodiode produced by spray pyrolysis

Energy Technology Data Exchange (ETDEWEB)

Shasti, M.; Mortezaali, A., E-mail: mortezaali@alzahra.ac.ir; Dariani, R. S. [Department of Physics, Alzahra University, Tehran 1993893973 (Iran, Islamic Republic of)

2015-01-14

In this study, Aluminum doped Zinc Oxide (AZO) layer is deposited on p-type silicon (p-Si) by spray pyrolysis method to fabricate ultraviolet-visible (UV/Vis) photodetector as Al doping process can have positive effect on the photodetector performance. Morphology, crystalline structure, and Al concentration of AZO layer are investigated by SEM, XRD, and EDX. The goal of this study is to analyze the mechanism of carrier transport by means of current-voltage characteristics under UV/Vis illumination in two cases: (a) electrodes connected to the surface of AZO layer and (b) electrodes connected to cross section of heterojunction (AZO/p-Si). Measurements indicate that the AZO/p-Si photodiode exhibits a higher photocurrent and lower photoresponse time under visible illumination with respect to AZO photodetector; while under UV illumination, the above result is inversed. Besides, the internal junction field of AZO/p-Si heterojunction plays an important role on this mechanism.

Highly transparent conductive AZO/Zr50Cu50/AZO films in wide range of visible and near infrared wavelength grown by pulsed laser deposition

Directory of Open Access Journals (Sweden)

Jingyun Cheng

Full Text Available Novel AZO/Zr50Cu50/AZO tri-layer transparent conductive films with excellent transmittance in both visible and near infrared region were successfully prepared by pulsed laser deposition on glass substrates. The electrical and optical properties were investigated at various Zr50Cu50 thicknesses. As the AZO thickness was fixed at 50 nm and Zr50Cu50 thickness was varied between 1 and 18 nm, it was found that AZO (50 nm/Zr50Cu50/AZO (50 nm tri-layer films exhibited good conductivity and high transmittance in both visible and near infrared wavelength. Additionally, both the electrical and optical properties of AZO (50 nm/Zr50Cu50 (2 nm/AZO (50 nm tri-layer films were found to be sensitive to the growth temperature. In this work, the lowest sheet resistance (43 Ω/□ and relatively high transmittance (∼80% in the range of 400–2000 nm were achieved while the growth temperature was 350 °C. Furthermore, the AZO (50 nm/Zr50Cu50 (2 nm/AZO (50 nm thin film deposited at 350 °C exhibits the highest figure of merit of 1.42 × 10−3 Ω−1, indicating that the multilayer is promising for coated glasses and thin film solar cells. Keywords: Transparent conductive oxide, AZO, Zr50Cu50, Electrical and optical properties, Visible and near infrared transmittance

Modification of azo dyes by lactic acid bacteria.

Science.gov (United States)

Pérez-Díaz, I M; McFeeters, R F

2009-08-01

The ability of Lactobacillus casei and Lactobacillus paracasei to modify the azo dye, tartrazine, was recently documented as the result of the investigation on red coloured spoilage in acidified cucumbers. Fourteen other lactic acid bacteria (LAB) were screened for their capability to modify the food colouring tartrazine and other azo dyes of relevance for the textile industry. Most LAB modified tartrazine under anaerobic conditions, but not under aerobic conditions in modified chemically defined media. Microbial growth was not affected by the presence of the azo dyes in the culture medium. The product of the tartrazine modification by LAB was identified as a molecule 111 daltons larger than its precursor by liquid chromatography-mass spectrometry. This product had a purple colour under aerobic conditions and was colourless under anaerobic conditions. It absorbed light at 361 and 553 nm. LAB are capable of anabolizing azo dyes only under anaerobic conditions. IMPACT AND SIGNIFICANCE OF THE STUDY: Although micro-organisms capable of reducing the azo bond on multiple dyes have been known for decades, this is the first report of anabolism of azo dyes by food related micro-organisms, such as LAB.

Triphenyl{(E-4-[4-(phenyldiazenylphenyl]-4H-1,2,4-triazol-1-yl}boron

Directory of Open Access Journals (Sweden)

Daisuke Urakami

2009-10-01

Full Text Available In the title compound, C32H26BN5 or [(C14H11N5B(C6H53], the B atom is approximately tetrahedrally coordinated. The diazo unit is in a trans conformation, which is generally more stable than a cis one for aromatic azo compounds. The crystal structure features very weak C—H...π interactions. The dihedral angles between the central benzene ring and the terminal rings in the heterocycle are 62.64, 73.54 and 61.60°.

Synthesis and research of benzylamides of some isocyclic and heterocyclic acids as potential anticonvulsants.

Science.gov (United States)

Strupińska, Marzanna; Rostafińska-Suchar, Grazyna; Pirianowicz-Chaber, Elzbieta; Stables, James P; Jiang, Jeff; Paruszewski, Ryszard

2013-01-01

A series of benzylamides of isocyclic and heterocyclic acids was synthesized and tested in Anticonvulsant Screening Project (ASP) of Antiepileptic Drug Development Program (ADDP) of NIH. Near all synthesized derivatives of heterocyclic acids showed activity. All obtained derivatives of mono- and bicyclic isocyclic acids were inactive. The power of action of heterocyclic acids derivatives seems does not depend upon kind of heteroatom (N, O or S). One of the compounds (2-furoic acid benzylamide (4)) appeared most promising. It showed in minimal clonic seizure (6Hz) test (ASP) in rats after i. p. administration: MES ED50 = 36.5 mg/kg, TOX TD50 = 269.75 mg/kg, and PI = 7.39.

Antiferroelectric phase in liquid crystalline compounds with azo group in their molecular core

Czech Academy of Sciences Publication Activity Database

Kašpar, Miroslav; Novotná, Vladimíra; Hamplová, Věra; Podoliak, Natalia; Nonnenmacher, D.; Giesselmann, F.; Glogarová, Milada

2011-01-01

Roč. 38, č. 3 (2011), s. 309-315 ISSN 0267-8292 R&D Projects: GA AV ČR IAA100100911; GA AV ČR(CZ) GA202/09/0047 Grant - others:German Czech bilateral program(DE) D4-CZ5/2010-2011; GA UK(CZ) SVV-2011-263303 Institutional research plan: CEZ:AV0Z10100520 Keywords : liquid crystals * antiferroelectricity * azo linkage group * photosensitivity Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.858, year: 2011

Preparation and Properties of Flexible AZO@C Nanofibers

Directory of Open Access Journals (Sweden)

MA Hui

2018-01-01

Full Text Available A new type of environmental-friendly flexible nanofibers of aluminum doped zinc oxide (AZO coated carbon (AZO@C was successfully prepared by using polyvinyl alcohol (PVA as raw materials. The as-spun PVA nanofibers were prepared via electrospinning and its water resistance was greatly improved after heat-treatment. Then, the PVA nanofibers with a layer of zinc aluminum hydroxide on the surface were synthesized by hydrothermal method. Thereafter, new AZO@C composite nanofibers was produced after sintering at 500℃ to the carbonization of PVA nanofibers and the dehydration of zinc aluminum hydroxide to form AZO nanoparticles. The structure and properties of the samples were characterized by Fourier-transform infrared spectrometer (FT-IR, thermal gravimetric analyzer (TGA and scanning electron microscope (SEM. The average diameter of the AZO@C nanofibers is (320±45nm. The photocatalytic property of the resultant composite fibers is demonstrated by degrading methyl orange under solar light.

Synthesis and Biological Evaluation of Novel Benzimidazole Derivatives Bearing a Heterocyclic Ring at 4/5 Position

International Nuclear Information System (INIS)

Wubulikasimu, Reyila; Yang, Yanbing; Xue, Fei; Luo, Xianjin; Shao, Dongping; Li, Yuhuan; Gao, Rongmei; Ye, Weidong

2013-01-01

A series of novel benzimidazole derivatives bearing a heterocyclic ring as oxadiazole (21-32), thiadiazole (33-34), triazole (35-36) were synthesized and evaluated for their activities against Coxsackie virus B3 and B6 in Vero cells. Compounds 21-26, 31-36 with moieties of 2'-pyridyl, 3'-pyridyl and 4'-pyridyl at the 2-position and oxadiazoles, thiadiazole, or triazole substituent at the 4- or 5-position generally displayed activities against CVB3 and CVB6. Especially compound 24 (IC 50 = 1.08 μg/mL, SI = 61.7 against CVB3) was the promising candidate as lead compound for anti-enteroviral drug. It was observed in the incorporation of heterocyclic rings in benzimidazole at the 5-position could enhance their biological activities

Measurement and ANN prediction of pH-dependent solubility of nitrogen-heterocyclic compounds.

Science.gov (United States)

Sun, Feifei; Yu, Qingni; Zhu, Jingke; Lei, Lecheng; Li, Zhongjian; Zhang, Xingwang

2015-09-01

Based on the solubility of 25 nitrogen-heterocyclic compounds (NHCs) measured by saturation shake-flask method, artificial neural network (ANN) was employed to the study of the quantitative relationship between the structure and pH-dependent solubility of NHCs. With genetic algorithm-multivariate linear regression (GA-MLR) approach, five out of the 1497 molecular descriptors computed by Dragon software were selected to describe the molecular structures of NHCs. Using the five selected molecular descriptors as well as pH and the partial charge on the nitrogen atom of NHCs (QN) as inputs of ANN, a quantitative structure-property relationship (QSPR) model without using Henderson-Hasselbalch (HH) equation was successfully developed to predict the aqueous solubility of NHCs in different pH water solutions. The prediction model performed well on the 25 model NHCs with an absolute average relative deviation (AARD) of 5.9%, while HH approach gave an AARD of 36.9% for the same model NHCs. It was found that QN played a very important role in the description of NHCs and, with QN, ANN became a potential tool for the prediction of pH-dependent solubility of NHCs. Copyright © 2015 Elsevier Ltd. All rights reserved.

Characteristics of indium-free GZO/Ag/GZO and AZO/Ag/AZO multilayer electrode grown by dual target DC sputtering at room temperature for low-cost organic photovoltaics

Energy Technology Data Exchange (ETDEWEB)

Park, Ho-Kyun; Kim, Han-Ki [Department of Display Materials Research Center, Materials Research Center for Information Displays (MRCID), Kyung Hee University, 1 Seocheon-dong, Youngin-si, Gyeonggi-do 446-701 (Korea); Kang, Jae-Wook [Department of Material Processing, Korea Institute of Materials Science(KIMS), 66 Sangnam-dong, Changwon-si, Gyeongnam 641-831 (Korea); Na, Seok-In; Kim, Don-Yu. [Heeger Center for Advanced Materials, Department of Materials Science and Engineering, Gwangju Institute of Science and Technology, 1 Oryoung-dong, Gwangju 500-712 (Korea)

2009-11-15

We compared the electrical, optical, structural and surface properties of indium-free Ga-doped ZnO (GZO)/Ag/GZO and Al-doped ZnO (AZO)/Ag/AZO multilayer electrodes deposited by dual target direct current sputtering at room temperature for low-cost organic photovoltaics. It was shown that the electrical and optical properties of the GZO/Ag/GZO and AZO/Ag/AZO multilayer electrodes could be improved by the insertion of an Ag layer with optimized thickness between oxide layers, due to its very low resistivity and surface plasmon effect. In addition, the Auger electron spectroscopy depth profile results for the GZO/Ag/GZO and AZO/Ag/AZO multilayer electrodes showed no interfacial reaction between the Ag layer and GZO or AZO layer, due to the low preparation temperature and the stability of the Ag layer. Moreover, the bulk heterojunction organic solar cell fabricated on the multilayer electrodes exhibited higher power conversion efficiency than the organic solar cells fabricated on the single GZO or AZO layer, due to much lower sheet resistance of the multilayer electrode. This indicates that indium-free GZO/Ag/GZO and AZO/Ag/AZO multilayer electrodes are a promising low-cost and low-temperature processing electrode scheme for low-cost organic photovoltaics. (author)

Structural evolution, electrical and optical properties of AZO films ...

Indian Academy of Sciences (India)

Administrator

Aluminum-doped zinc oxide (AZO) target was fabricated using AZO ... All AZO films show c-axis preferred orientation and hexagonal structure. With increasing film thick- ness from 153 to 1404 nm, the crystallinity was improved and the angle of (002) peak was close to ... For observing grain boundary and size, the target was.

Azo dye decolorization assisted by chemical and biogenic sulfide

Energy Technology Data Exchange (ETDEWEB)

Prato-Garcia, Dorian [Laboratory for Research on Advanced Processes for Water Treatment, Unidad Académica Juriquilla, Instituto de Ingeniería, Universidad Nacional Autónoma de México, Blvd. Juriquilla 3001, Querétaro 76230 (Mexico); Cervantes, Francisco J. [División de Ciencias Ambientales, Instituto Potosino de Investigación Científica y Tecnológica, Camino a la Presa de San José 2055, San Luis Potosí 78216 (Mexico); Buitrón, Germán, E-mail: gbuitronm@ii.unam.mx [Laboratory for Research on Advanced Processes for Water Treatment, Unidad Académica Juriquilla, Instituto de Ingeniería, Universidad Nacional Autónoma de México, Blvd. Juriquilla 3001, Querétaro 76230 (Mexico)

2013-04-15

Highlights: ► Azo dyes were reduced efficiently by chemical and biogenic sulfide. ► Biogenic sulfide was more efficient than chemical sulfide. ► There was no competition between dyes and sulfate for reducing equivalents. ► Aromatic amines barely affected the sulfate-reducing process. -- Abstract: The effectiveness of chemical and biogenic sulfide in decolorizing three sulfonated azo dyes and the robustness of a sulfate-reducing process for simultaneous decolorization and sulfate removal were evaluated. The results demonstrated that decolorization of azo dyes assisted by chemical sulfide and anthraquinone-2,6-disulfonate (AQDS) was effective. In the absence of AQDS, biogenic sulfide was more efficient than chemical sulfide for decolorizing the azo dyes. The performance of sulfate-reducing bacteria in attached-growth sequencing batch reactors suggested the absence of competition between the studied azo dyes and the sulfate-reducing process for the reducing equivalents. Additionally, the presence of chemical reduction by-products had an almost negligible effect on the sulfate removal rate, which was nearly constant (94%) after azo dye injection.

Biochemical interpretation of quantitative structure-activity relationships (QSAR) for biodegradation of N-heterocycles: a complementary approach to predict biodegradability.

Science.gov (United States)

Philipp, Bodo; Hoff, Malte; Germa, Florence; Schink, Bernhard; Beimborn, Dieter; Mersch-Sundermann, Volker

2007-02-15

Prediction of the biodegradability of organic compounds is an ecologically desirable and economically feasible tool for estimating the environmental fate of chemicals. We combined quantitative structure-activity relationships (QSAR) with the systematic collection of biochemical knowledge to establish rules for the prediction of aerobic biodegradation of N-heterocycles. Validated biodegradation data of 194 N-heterocyclic compounds were analyzed using the MULTICASE-method which delivered two QSAR models based on 17 activating (OSAR 1) and on 16 inactivating molecular fragments (GSAR 2), which were statistically significantly linked to efficient or poor biodegradability, respectively. The percentages of correct classifications were over 99% for both models, and cross-validation resulted in 67.9% (GSAR 1) and 70.4% (OSAR 2) correct predictions. Biochemical interpretation of the activating and inactivating characteristics of the molecular fragments delivered plausible mechanistic interpretations and enabled us to establish the following biodegradation rules: (1) Target sites for amidohydrolases and for cytochrome P450 monooxygenases enhance biodegradation of nonaromatic N-heterocycles. (2) Target sites for molybdenum hydroxylases enhance biodegradation of aromatic N-heterocycles. (3) Target sites for hydratation by an urocanase-like mechanism enhance biodegradation of imidazoles. Our complementary approach represents a feasible strategy for generating concrete rules for the prediction of biodegradability of organic compounds.

MICROWAVE IRRADIATION IN BENIGN SYNTHESIS OF HETEROCYCLES, NOBLE NANOMETALS AND NANOCOMPOSITES

Science.gov (United States)

A brief historic account of reactions involving microwave (MW) exposure of neat reactants or catalyzed by mineral support surfaces, such as alumina, silica, clay, or their ‘doped’ versions, for the rapid one-pot assembly of heterocyclic compounds [1] from in situ generated reacti...

Ion irradiation of AZO thin films for flexible electronics

Energy Technology Data Exchange (ETDEWEB)

Boscarino, Stefano; Torrisi, Giacomo; Crupi, Isodiana [IMM-CNR and Dipartimento di Fisica e Astronomia, Università di Catania, via S. Sofia 64, 95123 Catania (Italy); Alberti, Alessandra [CNR-IMM, via Strada VIII 5, 95121 Catania (Italy); Mirabella, Salvatore; Ruffino, Francesco [IMM-CNR and Dipartimento di Fisica e Astronomia, Università di Catania, via S. Sofia 64, 95123 Catania (Italy); Terrasi, Antonio, E-mail: antonio.terrasi@ct.infn.it [IMM-CNR and Dipartimento di Fisica e Astronomia, Università di Catania, via S. Sofia 64, 95123 Catania (Italy)

2017-02-01

Highlights: • Evidence of electrical good quality AZO ultra thin films without thermal annealing. • Evidence of the main role of Oxygen vs. structural parameters in controlling the electrical performances of AZO. • Evidence of the role of the ion irradiation in improving the electrical properties of AZO ultra thin films. • Synthesis of AZO thin films on flexible/plastic substrates with good electrical properties without thermal processes. - Abstract: Aluminum doped Zinc oxide (AZO) is a promising transparent conductor for solar cells, displays and touch-screen technologies. The resistivity of AZO is typically improved by thermal annealing at temperatures not suitable for plastic substrates. Here we present a non-thermal route to improve the electrical and structural properties of AZO by irradiating the TCO films with O{sup +} or Ar{sup +} ion beams (30–350 keV, 3 × 10{sup 15}–3 × 10{sup 16} ions/cm{sup 2}) after the deposition on glass and flexible polyethylene naphthalate (PEN). X-ray diffraction, optical absorption, electrical measurements, Rutherford Backscattering Spectrometry and Atomic Force Microscopy evidenced an increase of the crystalline grain size and a complete relief of the lattice strain upon ion beam irradiation. Indeed, the resistivity of thin AZO films irradiated at room temperature decreased of two orders of magnitude, similarly to a thermal annealing at 400 °C. We also show that the improvement of the electrical properties does not simply depend on the strain or polycrystalline domain size, as often stated in the literature.

UV-visible-DAD and 1H-NMR spectroscopy data fusion for studying the photodegradation process of azo-dyes using MCR-ALS.

Science.gov (United States)

Fernández, Cristina; Pilar Callao, M; Larrechi, M Soledad

2013-12-15

The photodegradation process of three azo-dyes - Acid Orange 61, Acid Red 97 and Acid Brown 425 - was monitored simultaneously by ultraviolet-visible spectroscopy with diode array detector (UV-vis-DAD) and (1)H-nuclear magnetic resonance ((1)H-NMR). Multivariate curve resolution-alternating least squares (MCR-ALS) was applied to obtain the concentration and spectral profile of the chemical compounds involved in the process. The analysis of the H-NMR data suggests there are more intermediate compounds than those obtained with the UV-vis-DAD data. The fusion of UV-vis-DAD and the (1)H-NMR signal before the multivariate analysis provides better results than when only one of the two detector signals was used. It was concluded that three degradation products were present in the medium when the three azo-dyes had practically degraded. This study is the first application of UV-vis-DAD and (1)H-NMR spectroscopy data fusion in this field and illustrates its potential as a quick method for evaluating the evolution of the azo-dye photodegradation process. © 2013 Elsevier B.V. All rights reserved.

Fluoroalkyl Amino Reagents (FARs: A General Approach towards the Synthesis of Heterocyclic Compounds Bearing Emergent Fluorinated Substituents

Directory of Open Access Journals (Sweden)

Bruno Commare

2017-06-01

Full Text Available Fluorinated heterocycles are important building blocks in pharmaceutical, agrochemical and material sciences. Therefore, organofluorine chemistry has witnessed high interest in the development of efficient methods for the introduction of emergent fluorinated substituents (EFS onto heterocycles. In this context, fluoroalkyl amino reagents (FARs—a class of chemicals that was slightly forgotten over the last decades—has emerged again recently and proved to be a powerful tool for the introduction of various fluorinated groups onto (heteroaromatic derivatives.

Fluoroalkyl Amino Reagents (FARs): A General Approach towards the Synthesis of Heterocyclic Compounds Bearing Emergent Fluorinated Substituents.

Science.gov (United States)

Commare, Bruno; Schmitt, Etienne; Aribi, Fallia; Panossian, Armen; Vors, Jean-Pierre; Pazenok, Sergiy; Leroux, Frédéric R

2017-06-12

Fluorinated heterocycles are important building blocks in pharmaceutical, agrochemical and material sciences. Therefore, organofluorine chemistry has witnessed high interest in the development of efficient methods for the introduction of emergent fluorinated substituents (EFS) onto heterocycles. In this context, fluoroalkyl amino reagents (FARs)-a class of chemicals that was slightly forgotten over the last decades-has emerged again recently and proved to be a powerful tool for the introduction of various fluorinated groups onto (hetero)aromatic derivatives.

An overview of the key routes to the best selling 5-membered ring heterocyclic pharmaceuticals

Directory of Open Access Journals (Sweden)

Nikzad Nikbin

2011-04-01

Full Text Available This review presents a comprehensive overview on selected synthetic routes towards commercial drug compounds as published in both journal and patent literature. Owing to the vast number of potential structures, we have concentrated only on those drugs containing five-membered heterocycles and focused principally on the assembly of the heterocyclic core. In order to target the most representative chemical entities the examples discussed have been selected from the top 200 best selling drugs of recent years.

Understanding effects of chemical structure on azo dye decolorization characteristics by Aeromonas hydrophila

Energy Technology Data Exchange (ETDEWEB)

Hsueh, Chung-Chuan [Department of Chemical and Materials Engineering, National I-Lan University, I-Lan 260, Taiwan (China); Chen, Bor-Yann, E-mail: bychen@niu.edu.tw [Department of Chemical and Materials Engineering, National I-Lan University, I-Lan 260, Taiwan (China); Yen, Chia-Yi [Department of Chemical and Materials Engineering, National I-Lan University, I-Lan 260, Taiwan (China)

2009-08-15

This novel comparative study tended to disclose how the molecular structures present in seven azo dyes including two types of azo dyes (i.e., naphthol type azo dyes - Reactive Black 5 (RB 5), Reactive Blue 171 (RB 171), Reactive Green 19 (RG19), Reactive Red 198 (RR198), Reactive Red 141 (RR141) and non-naphthol type azo dyes - Direct Yellow 86 (DY86), Reactive Yellow 84 (RY84)) affected color removal capability of Aeromonas hydrophila. Generally speaking, the decolorization rate of naphthol type azo dye with hydroxyl group at ortho to azo bond was faster than that of non-naphthol type azo dye without hydroxyl group, except of RG19. The azo dyes with electron-withdrawing groups (e.g., sulfo group in RR198, RB5 and RR141) would be easier to be decolorized than the azo dyes with the electron-releasing groups (e.g., -NH-triazine in RB171 and RG19). In addition, the azo dyes containing more electron-withdrawing groups (e.g., RR198, RB5 and RR141) showed significantly faster rate of decolorization. The azo dyes with electron-withdrawing groups (e.g., sulfo group) at para and ortho to azo bond (e.g., RR198, RB5 and RR141) could be more preferred for color removal than those at meta (e.g., DY86 and RY84). The former azo dyes with para and ortho sulfo group provided more effective resonance effects to withdraw electrons from azo bond, causing azo dyes to be highly electrophilic for faster rates of reductive biodecolorization. However, since the ortho substituent caused steric hindrance near azo linkage(s), azo dyes with para substituent could be more favorable (e.g., SO{sub 2}(CH{sub 2}){sub 2}SO{sub 4}{sup -} in RR198 and RB5) than those with ortho substituent (e.g., sulfo group at RR141) for decolorization. Thus, the ranking of the position for the electron-withdrawing substituent in azo dyes to escalate decolorization was para > ortho > meta. This study suggested that both the positions of substituents on the aromatic ring and the electronic characteristics of

Quenching of excited uranyl ion during its photochemical reduction with triphenyl-phosphine : Part IV - effect of heterocyclic molecules

International Nuclear Information System (INIS)

Sidhu, M.S.; Bhatia, P.V.K.

1994-01-01

The presence of heterocyclic compounds triggers off a competition between photophysical and photochemical annihilation of excited uranyl ion during its photochemical reduction with triphenylphosphine. This competition is used to measure Stern-Volmer constant using UV visible spectrophotometer for quenching the uranyl ion luminescence with a number of heterocyclic molecules viz., pyridine, thiophene bipyridyl, tetrahydrofuran and piperidine. (author). 7 refs., 2 figs., 1 tab

Radiation degradation and hemolytic toxicity evaluation of mono azo reactive dyes

International Nuclear Information System (INIS)

Saeed, Q.U.; Bhatti, I.A.; Ashraf, A.

2017-01-01

Monoazo reactive dyes have been synthesized and subjected to degradation before their application. Advanced oxidation process has been recognized as a promising radiation technology for the remediation of hazardous organic compounds. Radiation induced degradation of two mono azo reactive dyes have been tried at different absorbed dose, 5 kGy,10 kGy and 15 kGy. Aqueous solutions of these dyes were treated with gamma radiation using Cs 137 radiation source at Nuclear Institute of Agriculture and Biology (NIAB) Faisalabad. Dyes were evaluated spectrophotometrically by UV-visible and fourier transform infra red (FT-IR) spectroscopic techniques before and after irradiation to analyse their percentage decolorization and degradation. Maximum percentage decolorization of 93% and 63% was achieved for mono azo dyes D1 and D2 at 15 kGy absorbed dose. Toxicity study of these dyes was also tested by haemolytic activity assay. Percentage haemolytic activity of untreated dyes was found within permissible limit showing non toxicity of dye solutions. (author)

Effects of reduction products of ortho-hydroxyl substituted azo dyes on biodecolorization of azo dyes

International Nuclear Information System (INIS)

Liu Guangfei; Wang Jing; Lu Hong; Jin Ruofei; Zhou Jiti; Zhang Long

2009-01-01

The mediated effects of reduction products of some ortho-hydroxyl substituted azo dyes on biodecolorization were investigated. The results indicated that the addition of reduction products could effectively accelerate dye decolorization by Shigella sp. QRZ-1. The best accelerating effect was obtained with the addition of reduction products of Acid Red 14 (AR14), resulting in an over 3-fold increase in decolorization efficiency of many azo dyes. In sequencing batch reactor experiments, the accelerating effect of reduction products of AR14 was more obvious (1.5-fold) during the startup of the system. When the dye concentration was increased to 500 mg L -1 , the accelerated decolorization efficiency was still maintained around 95%. The presence of AR14 in the feed enhanced the decolorization performance of anaerobic sludge, indicating that the strategy may be beneficial for practical application. 1-Naphthol-2-amino-4-sulfonic acid, which is one of the reduction products of AR14, may function as redox mediator to speed up azo dye biodecolorization.

Greener Synthesis of N-Heterocycles via Sustainable Applications of Nano-Catalysts

Science.gov (United States)

A brief historic account of reactions involving microwave (MW) exposure of neat reactants or catalysis by mineral surfaces, such as alumina, silica, clay, or their ‘doped’ versions, for the rapid one-pot assembly of heterocyclic compounds from in situ generated reactive intermedi...

Solid-phase synthesis of complex and pharmacologically interesting heterocycles

DEFF Research Database (Denmark)

Nielsen, Thomas Eiland

2009-01-01

Efficient routes for the creation of heterocycles continue to be one of the primary goals for solid-phase synthesis. Recent advances in this field rely most notably on transition-metal-catalysis and N-acyliminium chemistry to mediate a range of cyclization processes for the generation of compounds...... with significant structural complexity and diversity. This review describes some of the most systematic solid-phase approaches that are potentially suited for pharmaceutical applications, that is, the methods described are useful for the synthesis of compound collections, and exhibit tunable stereochemistry...

Investigation of the structure and properties of heterocyclic compounds and their complexes

International Nuclear Information System (INIS)

Shejnker, V.N.; Troilina, V.S.; Merinova, E.G.; Garnovskij, A.D.; Osipov, O.A.

1988-01-01

Complexing of acetyl derivatives of azoles with iodine and bromine iodide is investigated using UV-spectroscopy and dipole moment methods. In bimolecular complexes σ-acceptor coordination occurs by heterocycle pyridine type nitrogen atom and is not accompanied by the ligand conformation change. The complex stability increases in agreement with azole basicity. For N-acetyltriazole ligand, conformation reversal occurs in its trimolecular complex with IBr

Microwave-Assisted Synthesis of Bio-Active Heterocycles and Fine Chemicals in Aqueous Media

Science.gov (United States)

Human health, especially in the aging population, mostly depends on various medicines, and researchers are combating against emerging diseases by new drug discovery. Heterocyclic compounds hold a special place among pharmaceutically active natural products as well as synthetic co...

Synthesis and Radiolabeling of Modified Peptides Attached to Heterocyclic Rings and Their Possible Medical Applications

International Nuclear Information System (INIS)

Shams El-Din, H.A.A.

2012-01-01

Keeping in mind the pharmacological potential of heterocyclic rings as well as the advantage of biodegradability and biocompatibility of amino acids/peptides, in this thesis we were prompted for the following: 1. Synthesis of novel dipeptide derivatives coupled with different heterocyclic rings (pyridine, 1,2,4-triazol-pyridine, 1,3,4-oxadiazolpyridine and tetrazol-pyridine rings). 2. Characterization of the synthesized compounds on the basis of their spectral data (IR, Mass and 1 H-NMR spectra). 3. Study their antimicrobial activity as one of their expected biological activities. 4. Study the radioiodination of some synthesized dipeptide derivatives. 5. Study the biodistribution of the radiolabeled compounds in normal mice as preliminary studies for the possibility of using them as agents for imaging and treatment.

UV-vis, IR and 1H NMR spectroscopic studies of some mono- and bis-azo-compounds based on 2,7-dihydroxynaphthalene and aniline derivatives

Science.gov (United States)

Issa, Raafat M.; Fayed, Tarek A.; Awad, Mohammed K.; El-Kony, Sanaa M.

2005-12-01

The absorption spectra of mono- and bis-azo-derivatives obtained by coupling the diazonium salts of aromatic amines and 2,7-dihydroxynaphthalene have been studied in six organic solvents. The different absorption bands have been assigned and the effect of solvents on the charge transfer band is also discussed. The diagnostic IR spectral bands and 1H NMR signals are assigned and discussed in relation to molecular structure. Also, semi-empirical molecular orbital calculations using the atom superposition and electron delocalization molecular orbital (ASED-MO) theory have been performed to investigate the molecular and electronic structures of these compounds. According to these calculations, an intramolecular hydrogen bonding is essential for stabilization of such molecules.

Synthesis, Characterisation and DFT Calculations of Azo-Imine Dyes

Directory of Open Access Journals (Sweden)

Sevil Özkınalı

2017-11-01

Full Text Available In this study, azo dyes containing an imine group were synthesised by coupling p-hydroxybenzylidene aniline with the diazonium salts of p-toluidine, 4-aminophenol, aniline, p-chloroaniline, p-fluoroaniline, and p-nitroaniline. The compounds were characterised by melting point, elemental, UV-Vis and IR analyses as well as 1H-NMR and 13C-NMR spectroscopies. Moreover, the experimental data were supplemented with density functional theory (DFT calculations. The experimental data on FT-IR and UV–Vis spectra of the compounds were compared with theoretical results. The DFT calculations were performed to obtain the ground state geometries of the compounds using the B3LYP hybrid functional level with 6-311++g(2d,2p basis set. Frontier molecular orbital energies, band gap energies and some chemical reactivity parameters, such as chemical hardness and electronegativity, were calculated and compared with experimental values. A significant correlation was observed between the dipole moment and polarities of the solvents and the absorption wavelength of the compounds.

Electronic bond tuning with heterocyclic carbenes

KAUST Repository

Falivene, Laura

2013-01-01

We discuss the impact of the nature of the heterocyclic carbene ring, when used as a complex forming ligand, on the relative stability of key intermediates in three typical Ru, Pd and Au promoted reactions. Results show that P-heterocyclic carbenes have a propensity to increase the bonding of the labile ligand and of the substrate in Ru-promoted olefin metathesis, whereas negligible impact is expected on the stability of the ruthenacycle intermediate. In the case of Pd cross-coupling reactions, dissociation of a P-heterocyclic carbene is easier than dissociation of the N-heterocyclic analogue. In the case of the Au-OH synthon, the Au-OH bond is weakened with the P-heterocyclic carbene ligands. A detailed energy decomposition analysis is performed to rationalize these results. © 2013 The Royal Society of Chemistry.

Effects of reduction products of ortho-hydroxyl substituted azo dyes on biodecolorization of azo dyes

Energy Technology Data Exchange (ETDEWEB)

Liu Guangfei [Key Laboratory of Industrial Ecology and Environmental Engineering, Ministry of Education, School of Environmental and Biological Science and Technology, Dalian University of Technology, Linggong Road No. 2, Dalian 116024 (China); Wang Jing, E-mail: wangjingbio@yahoo.cn [Key Laboratory of Industrial Ecology and Environmental Engineering, Ministry of Education, School of Environmental and Biological Science and Technology, Dalian University of Technology, Linggong Road No. 2, Dalian 116024 (China); Lu Hong; Jin Ruofei; Zhou Jiti; Zhang Long [Key Laboratory of Industrial Ecology and Environmental Engineering, Ministry of Education, School of Environmental and Biological Science and Technology, Dalian University of Technology, Linggong Road No. 2, Dalian 116024 (China)

2009-11-15

The mediated effects of reduction products of some ortho-hydroxyl substituted azo dyes on biodecolorization were investigated. The results indicated that the addition of reduction products could effectively accelerate dye decolorization by Shigella sp. QRZ-1. The best accelerating effect was obtained with the addition of reduction products of Acid Red 14 (AR14), resulting in an over 3-fold increase in decolorization efficiency of many azo dyes. In sequencing batch reactor experiments, the accelerating effect of reduction products of AR14 was more obvious (1.5-fold) during the startup of the system. When the dye concentration was increased to 500 mg L{sup -1}, the accelerated decolorization efficiency was still maintained around 95%. The presence of AR14 in the feed enhanced the decolorization performance of anaerobic sludge, indicating that the strategy may be beneficial for practical application. 1-Naphthol-2-amino-4-sulfonic acid, which is one of the reduction products of AR14, may function as redox mediator to speed up azo dye biodecolorization.

40 CFR 721.2097 - Azo chromium complex dyestuff preparation (generic name).

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Azo chromium complex dyestuff... New Uses for Specific Chemical Substances § 721.2097 Azo chromium complex dyestuff preparation... substance identified generically as an azo chromium complex dyestuff preparation (PMN P-95-240) is subject...

Gas phase radiolysis and vacuum ultraviolet photolysis of heterocyclic organic compounds. Progress report, February 1, 1974--February 1, 1975

International Nuclear Information System (INIS)

Scala, A.A.; Salomon, D.; Colon, I.; D'Angona, J.

1975-01-01

In the γ radiolysis of tetrahydrofuran there are pronounced density effects in the pressure range from 0 to 50 Torr with the most important ion-pair yields decreasing as the pressure increases. The relative product yields of the radiolysis is compared with that of xenon photolysis. Possible mechanisms to explain the results obtained are discussed. The ion-pair yields from the γ radiolysis of the heterocyclic amines, ethylenimine, azetidine, pyrrolidine, and piperidine, are determined, and the pressure effects are evaluated. Reactions mechanisms are discussed. The vacuum ultraviolet photolysis products of thietane and tetrahydrothiophene are studied and compared with the γ radiolysis products. Reaction mechanisms are discussed. The status of the construction of a photoionization mass spectrometer and the measurement of the ionization efficiencies and extinction coefficients of organic compounds is reported. (U.S.)

High-Quality AZO/Au/AZO Sandwich Film with Ultralow Optical Loss and Resistivity for Transparent Flexible Electrodes.

Science.gov (United States)

Zhou, Hua; Xie, Jing; Mai, Manfang; Wang, Jing; Shen, Xiangqian; Wang, Shuying; Zhang, Lihua; Kisslinger, Kim; Wang, Hui-Qiong; Zhang, Jinxing; Li, Yu; Deng, Junhong; Ke, Shanming; Zeng, Xierong

2018-05-09

Transparent flexible electrodes are in ever-growing demand for modern stretchable optoelectronic devices, such as display technologies, solar cells, and smart windows. Such sandwich-film-electrodes deposited on polymer substrates are unattainable because of the low quality of the films, inducing a relatively large optical loss and resistivity as well as a difficulty in elucidating the interference behavior of light. In this article, we report a high-quality AZO/Au/AZO sandwich film with excellent optoelectronic performance, e.g., an average transmittance of about 81.7% (including the substrate contribution) over the visible range, a sheet resistance of 5 Ω/sq, and a figure-of-merit (FoM) factor of ∼55.1. These values are well ahead of those previously reported for sandwich-film-electrodes. Additionally, the interference behaviors of light modulated by the coat and metal layers have been explored with the employment of transmittance spectra and numerical simulations. In particular, a heater device based on an AZO/Au/AZO sandwich film exhibits high performance such as short response time (∼5 s) and uniform temperature field. This work provides a deep insight into the improvement of the film quality of the sandwich electrodes and the design of high-performance transparent flexible devices by the application of a flexible substrate with an atomically smooth surface.

Complexes of uranyl with N-oxides of heterocyclic amines. Electron-vibrational absorption spectra

International Nuclear Information System (INIS)

Jezowska-Trzebiatowska, B.; Wieczorek, M.

1977-01-01

A number of coordination compounds formed by uranyl chloride and nitrate with N-oxides of heterocyclic amines have been prepared and characterized by spectral measurements in the absorption region 20000-50000 cm -1 . The electrons and vibronic transitions have been determined and discussed. (author)

Synthesis of heterocycle-attached methylidenebenzenesulfonohydrazones as antifungal agents.

Science.gov (United States)

Gao, Zhinan; Lv, Min; Li, Qin; Xu, Hui

2015-11-15

A series of heterocycle-attached methylidenebenzenesulfonohydrazone derivatives were synthesized and evaluated for their antifungal activities against seven phytopathogenic fungi such as Fusarium graminearum, Alternaria solani, Valsa mali, Phytophthora capsici, Fusarium solani, Botrytis cinerea, and Glomerella cingulata. Compounds 7b, 8d, 9a, 9b and 9d exhibited a good and broad-spectrum of antifungal activities against at least five phytopathogenic fungi at the concentration of 100 μg/mL. It demonstrated that addition of one double bond between the phenylsulfonylhydrazone fragment and the furan ring of 6a,b,d could afford more active compounds 9a,b,d; however, introduction of the nitro group on the phenyl ring of 6a-9a gave less potent compounds 6e-9e. Copyright © 2015 Elsevier Ltd. All rights reserved.

The design and synthesis of novel spirocyclic heterocyclic sulfone ROMK inhibitors as diuretics.

Science.gov (United States)

Chobanian, Harry R; Guo, Yan; Pio, Barbara; Tang, Haifeng; Teumelsan, Nardos; Clements, Matthew; Frie, Jessica; Ferguson, Ronald; Guo, Zach; Thomas-Fowlkes, Brande S; Felix, John P; Liu, Jessica; Kohler, Martin; Priest, Birgit; Hampton, Caryn; Pai, Lee-Yuh; Corona, Aaron; Metzger, Joseph; Tong, Vincent; Joshi, Elizabeth M; Xu, Ling; Owens, Karen; Maloney, Kevin; Sullivan, Kathleen; Pasternak, Alexander

2017-02-15

A spirocyclic class of ROMK inhibitors was developed containing a structurally diverse heterocyclic sulfone moiety and spirocyclic core starting from lead 1. These compounds not only displayed exquisite ROMK potency but significantly improved selectivity over hERG. The lead compounds were found to have favorable pharmacokinetic properties and displayed robust diuretic, natriuretic and blood pressure lowering effects in spontaneously hypertensive rats. Copyright © 2016 Elsevier Ltd. All rights reserved.

New chiral zwitterionic phosphorus heterocycles: synthesis, structure, properties and application as chiral solvating agents.

Science.gov (United States)

Sheshenev, Andrey E; Boltukhina, Ekaterina V; Grishina, Anastasiya A; Cisařova, Ivana; Lyapkalo, Ilya M; Hii, King Kuok Mimi

2013-06-17

A family of new chiral zwitterionic phosphorus-containing heterocycles (zPHC) have been derived from methylene-bridged bis(imidazolines). These structures were unambiguously determined, including single-crystal XRD analysis for two compounds. The stability, acid/base and electronic properties of these dipolar phosphorus heterocycles were subsequently investigated. zPHCs can be successfully employed as a new class of chiral solvating agents for the enantiodifferentiation of chiral carboxylic and sulfonic acids by NMR spectroscopy. The stoichiometry and binding constants for the donor-acceptor complexes formed were established by NMR titration methods. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Azole-Anion-Based Aprotic Ionic Liquids: Functional Solvents for Atmospheric CO2 Transformation into Various Heterocyclic Compounds.

Science.gov (United States)

Zhao, Yanfei; Wu, Yunyan; Yuan, Guangfeng; Hao, Leiduan; Gao, Xiang; Yang, Zhenzhen; Yu, Bo; Zhang, Hongye; Liu, Zhimin

2016-10-06

The chemical transformation of atmospheric CO 2 is of great significance yet still poses a great challenge. Herein, azole-anion-based aprotic ionic liquids (ILs) were synthesized by the deprotonation of weak proton donors (e.g., 2-methylimidazole, 4-methylimidazole, and 2,4-dimethylimidazole) with tetrabutylphosphonium hydroxide, [Bu 4 P][OH]. We found that these ILs, such as [Bu 4 P][2-MIm], could activate atmospheric CO 2 through the formation of carbamates. The resultant carbamate intermediates could further react with various types of substrate, including propargylic alcohols, 2-aminobenzonitriles, ortho-phenylenediamines, and 2-aminothiophenol, thereby producing α-alkylidene cyclic carbonates, quinazoline-2,4(1 H,3 H)-diones, benzimidazolones, and benzothiazoline, respectively, in moderate-to-good yields. Thus, we have achieved the transformation of CO 2 at atmospheric pressure, and we expect this method to open up new routes for the synthesis of various oxygen-containing heterocyclic compounds under metal-free conditions. © 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Radioprotective properties of some heterocyclic nitrogenous compounds against changes in hemoglobin concentration and hematocrit value in x-irradiated mice; Proprietes radioprotectrices de certains composes heterocycliques azotes sur les variations du taux d'hemoglobine et de la valeur hematocrite chez la souris irradiee

Energy Technology Data Exchange (ETDEWEB)

Rousdhy, H; Pierotti, T; Polverelli, M [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

1969-07-01

Radioprotective properties of imidazole and benzimidazole have been proved in previous works. In this study, authors try to demonstrate radioprotective action of these compounds in comparison with cysteamine upon the hematopoietic system after lethal X-irradiation. Results show: no drastic variations of hematologic constants (hemoglobin concentration and hematocrit value) after intraperitoneal injection of radioprotective compounds apart certain apparent reactions with the heterocyclic compounds; the better radioprotective action of benzimidazole. Twenty five days after irradiation, hemoglobin concentration and hematocrit of radio protected mice return to normal values. (author) [French] Les proprietes radioprotectrices de l'imidazole et du benzimidazole ayant ete demontrees dans de precedents travaux, les auteurs se sont attaches a etudier l'action de ces produits sur le systeme hematopofetique en comparaison avec celle de la cysteamine, apres une irradiation a dose letale. A l'aide des criteres choisis, les resultats demontrent: qu'en dehors de certaines reactions apparentes, succedant a l'injection intraperitoneale des heterocycles azotes, les constantes hematologiques (taux d'hemoglobine et valeur hematocrite) ne sont que legerement modifiees; la superiorite du benzimidazole sur les autres produits utilises. Enfin, le vingt-cinquieme jour apres irradiation, les souris protegees par les heterocycles azotes ont un taux d'hemoglobine et une valeur hematocrite tout a fait normaux. (auteur)

Synthesis of acetylene alcohols of heterocyclic type and the acyl derivatives

Directory of Open Access Journals (Sweden)

Moldir Dyusebaeva

2015-03-01

Full Text Available A synthesis of potentially biologically active heterocyclic amino alcohols of acetylene (Piperidine and Morpholine under the conditions of Mannich reaction accomplished and received their acyl derivatives. Pharmacological activity (antibacterial and antispasmotic of synthesized compounds, also acute toxicological characteristics studied. The study showed that the combination of DMAE-4 has antispasmodic activity with low toxicity.

Synthesis and evaluation of ?-hydroxy fatty acid-derived heterocyclic compounds with potential industrial interest

Directory of Open Access Journals (Sweden)

El-Sayed, R.

2006-12-01

Full Text Available T2-Hydroxyheptadecanoic acid chloride (2 reacted with anthranilic acid to produce 2-substituted-3,1-benzoxazin-4-one (3 which was used as starting material to synthesize some condensed and non-condensed heterocyclic compounds by reaction with nitrogen nucleophiles e.g., hydrazine hydrate, and formamide. The products were subjected to reaction with different moles of propylene oxide (n = 5, 10, 15 to produce a novel group of nonionic compounds having a double function as antibacterial and surface active agents which can be used in the manufacturing of drugs, cosmetics, pesticides or can be used as antibacterial and/or antifungal additives. The surface active properties as surface and interfacial tension, cloud point, foaming height, wetting time, and emulsification power were determined, the antimicrobial and biodegradability were also screened.El cloruro del ácido 2-hidroxiheptadecanoico (2 reaccionó con el ácido antranílico para producir 3,1-benzoxazin-4-onas 2-sustituidas que fueron usadas como material de partida en la síntesis de compuestos heterocíclicos condensados y no condensados por reacción con nucleófilos nitrogenados, como la hidracina o la formamida. Los productos fueron hechos reaccionar con diferentes moles de óxido de propileno (n = 5, 10, 15 para producir un grupo nuevo de compuestos no-iónicos teniendo una doble función como antibacterianos y tensoactivos que pueden ser usados en la manufactura de medicamentos, cosméticos, pesticidas, o pueden ser usados como aditivos antibacterianos y/o antifúngicos. Se determinaron diversas propiedades físicas de los compuestos preparados así como sus efectos antimicrobianos y sus biodegrabilidad.

Chronic toxicity of polycyclic aromatic compounds to the springtail Folsomia candida and the enchytraeid Enchytraeus crypticus.

NARCIS (Netherlands)

Droge, S.T.J.; Leon Paumen, M; Bleeker, E.A.J.; Kraak, M.H.S.; van Gestel, C.A.M.

2006-01-01

An urgent need exists for incorporating heterocyclic compounds and (bio)transformation products in ecotoxicological test schemes and risk assessment of polycyclic aromatic compounds (PACs). The aim of the present study therefore was to determine the chronic effects of (heterocyclic) PACs on two

Light sensitive polymer obtained by dispersion of azo-functionalized POSS nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Miniewicz, A., E-mail: andrzej.miniewicz@pwr.edu.pl [Advanced Materials Engineering and Modelling, Faculty of Chemistry, Wroclaw University of Technology, Wybrzeze Wyspianskiego 27, 50-370 Wroclaw (Poland); Tomkowicz, M.; Karpinski, P.; Sznitko, L. [Advanced Materials Engineering and Modelling, Faculty of Chemistry, Wroclaw University of Technology, Wybrzeze Wyspianskiego 27, 50-370 Wroclaw (Poland); Mossety-Leszczak, B. [Faculty of Chemistry, Rzeszow University of Technology, Al. Powstancow Warszawy 12, 35-959 Rzeszow (Poland); Dutkiewicz, M. [Faculty of Chemistry, Adam Mickiewicz University of Poznan, Umultowska 89 B, 61-614 Poznan (Poland)

2015-07-29

Highlights: • Nanocomposite material PMMA containing azo-functionalized POSS has been prepared. • Surface topographies of prepared films are porous and dependent on azo-POSS content. • Photo-induced optical anisotropies both static and dynamic have been characterized. - Abstract: Hybrid inorganic–organic nanoparticles based on cubic siloxane cage (RSiO{sub 3/2}){sub 8}, known as polyhedral oligosilsesquioxane (POSS), have been functionalized by eight groups of azo-benzene mesogens and dispersed in poly(methyl methacrylate) PMMA matrix. Presence of azo-benzene units adds an important light-driven functionality to the system due to their photoisomerization resulting in refractive index and/or absorption changes of the whole system. The polymer films containing various concentrations of azo-POSS nanoparticles show remarkable changes of surface morphology being either transparent (at low POSS concentration) or highly scattering (at high POSS concentration) for visible light. Surface structures were examined by optical microscopy as well as by atomic force microscopy (AFM). Results of photoinduced alignment are discussed in the framework of light-induced modification of the aliphatic chains containing azo-benzene photoisomerizing moieties and self-organization process.

Light sensitive polymer obtained by dispersion of azo-functionalized POSS nanoparticles

International Nuclear Information System (INIS)

Miniewicz, A.; Tomkowicz, M.; Karpinski, P.; Sznitko, L.; Mossety-Leszczak, B.; Dutkiewicz, M.

2015-01-01

Highlights: • Nanocomposite material PMMA containing azo-functionalized POSS has been prepared. • Surface topographies of prepared films are porous and dependent on azo-POSS content. • Photo-induced optical anisotropies both static and dynamic have been characterized. - Abstract: Hybrid inorganic–organic nanoparticles based on cubic siloxane cage (RSiO 3/2 ) 8 , known as polyhedral oligosilsesquioxane (POSS), have been functionalized by eight groups of azo-benzene mesogens and dispersed in poly(methyl methacrylate) PMMA matrix. Presence of azo-benzene units adds an important light-driven functionality to the system due to their photoisomerization resulting in refractive index and/or absorption changes of the whole system. The polymer films containing various concentrations of azo-POSS nanoparticles show remarkable changes of surface morphology being either transparent (at low POSS concentration) or highly scattering (at high POSS concentration) for visible light. Surface structures were examined by optical microscopy as well as by atomic force microscopy (AFM). Results of photoinduced alignment are discussed in the framework of light-induced modification of the aliphatic chains containing azo-benzene photoisomerizing moieties and self-organization process

Synthesis and Antimicrobial Studies of New Series of Pyrazoline Bearing Bis-Heterocycles via 1,3-Dipolar Cycloaddition Reactions

Directory of Open Access Journals (Sweden)

B. Jayashankara

2008-01-01

Full Text Available Biologically interesting bis-heterocycles bearing pyrazoline and imidazole moieties have been synthesized. 1H NMR, 13C NMR, IR and elemental analyses characterized the newly synthesized compounds. All the synthesized compounds were evaluated for their antimicrobial activity and were compared with the standard drugs. All the compounds demonstrated potent to weak antimicrobial activity.

Analytical procedures for the determination of disperse azo dyes

Energy Technology Data Exchange (ETDEWEB)

Betowski, L.D.; Jones, T.L. (Environmental Protection Agency, Las Vegas, NV (USA)); Munslow, W.; Nunn, N.J. (Lockheed Engineering and Management Services Co., Las Vegas, NV (USA))

1988-09-01

Disperse Blue 79 is the most widely-used azo dye in the US. Its economic importance for the dye industry and textile industry is very great. Because of its use and potential for degradation to aromatic amines, this compound has been chosen for testing by the Interagency Testing Committee. The authors laboratory has been developing methods for the analytical determination of Disperse Blue 79 and any possible degradation products in wastewater. This work has been taking place in conjunction with the study of the fate of azo dyes in the wastewater treatment processes by the Water Engineering Research Laboratory of the US EPA in Cincinnati. There were various phases for this analytical development. The first step involved purifying the commercial material or presscake to obtain a standard for quantitative determination. A combination of HPLC, TLC and mass spectrometric methods was used to determine purity after extraction and column cleanup. Phase two involved the extraction of the dye from the matrices involved. The third phase was the actual testing of Disperse Blue 79 in the waste activated sludge system and anaerobic digester. Recovery of the dye and any degradation products at each sampling point (e.g., secondary effluent, waste activated sludge) was the goal of this phase.

Fabrication of AZO TCO Films by RF-sputtering and Their Physical Properties

Directory of Open Access Journals (Sweden)

Jang T.S.

2016-01-01

Full Text Available We report on the fabrication of Al-doped ZnO (AZO transparent-conductive oxide (TCO films on glass substrates by RF-sputtering, their physical properties, and the effect of thermal annealing on the AZO TCO films. The AZO films on glass substrates have a preferred orientation of the c-axis, irrespective of deposition conditions, which means that the AZO films have textured structures along the c-axis. The film thickness and surface roughness in the AZO films are proportional to plasma power and deposition time, while they are inverse-proportional to working gas ratio and working pressure. The AZO films have the optical transmittance over 80 % in the wavelength range of 400 – 1000 nm, irrespective of deposition conditions. The plasma power and the deposition time relatively give a large influence on the optical transmittance, compared to the working gas ratio and the working pressure. The AZO films deposited at room temperature have poor electrical properties, while the thermal annealing under Ar ambient significantly improves the electrical conductivity of the AZO films: an as-deposited sample has an electrical resistivity of 87 Wcm and an electron concentration of 1.3´1017 cm−3, while the annealed sample has an electrical resistivity of 3.7´10-2 Wcm and an electron concentration of 1.2´1020 cm−3.

Effect of the nature of p-substituents in benzene ring of azo compounds based on chromotropic acid on their reactivity

Energy Technology Data Exchange (ETDEWEB)

Savvin, S B; Dedkova, V P; Azarashvili, M A; Likhonina, E A

1988-08-01

Effect of acceptor and donor substituents in a reagent on degree of contrast and selectivity of spectrophotometric beryllium determination as well as other elements was considered taking derivatives of orthanilic-azo-chromotropic acid as an example. The optimal pH region of aminoorthanilic-azo-chromotropic acid interaction with Be 5-6.5; the optimal wavelength is 640 nm. The solution colour changes from violet-red to blue during complex formation. Selectivity increases after addition of masking substances. Be determination on the background of 4-fold Cu and VO/sup 2+/ amounts 8-fold Al amounts, 2-fold Zn amounts is possible in the presence of 5-fold EDTA amounts unsubstituted reagent is characterized by the lowest degree of contrast and selectivity of reactions with metals.

Composite glycerol/graphite/aromatic acid matrices for thin-layer chromatography/matrix-assisted laser desorption/ionization mass spectrometry of heterocyclic compounds.

Science.gov (United States)

Esparza, Cesar; Borisov, R S; Varlamov, A V; Zaikin, V G

2016-10-28

New composite matrices have been suggested for the analysis of mixtures of different synthetic organic compounds (N-containing heterocycles and erectile dysfunction drugs) by thin layer chromatography/matrix-assisted laser desorption ionization time-of-flight mass spectrometry (TLC/MALDI-TOF). Different mixtures of classical MALDI matrices and graphite particles dispersed in glycerol were used for the registration of MALDI mass spectra directly from TLC plates after analytes separation. In most of cases, the mass spectra possessed [M+H] + ions; however, for some analytes only [M+Na] + and [M+K] + ions were observed. These ions have been used to generate visualized TLC chromatograms. The described approach increases the desorption/ionization efficiencies of analytes separated by TLC, prevent spot blurring, simplifies and decrease time for sample preparation. Copyright © 2016 Elsevier B.V. All rights reserved.

Auranofin and N-heterocyclic carbene gold-analogs are potent inhibitors of the bacteria Helicobacter pylori.

Science.gov (United States)

Owings, Joshua P; McNair, Nina N; Mui, Yiu Fung; Gustafsson, Tomas N; Holmgren, Arne; Contel, Maria; Goldberg, Joanna B; Mead, Jan R

2016-07-01

Auranofin is an FDA-approved gold-containing compound used for the treatment of rheumatoid arthritis. Recent reports of antimicrobial activity against protozoa and bacteria indicate that auranofin targets the reductive enzyme thioredoxin reductase (TrxR). We evaluated auranofin as well as five auranofin analogs containing N-heterocyclic carbenes (instead of the triethylphosphane present in auranofin) and five gold-carbene controls for their ability to inhibit or kill Helicobacter pylori in vitro Auranofin completely inhibited bacterial growth at 1.2 μM. Purified H. pylori TrxR was inhibited by auranofin in a cell-free assay (IC50 ∼88 nM). The most active gold(I)-N-heterocyclic carbene compounds exhibited MICs comparable to auranofin against H. pylori (2 μM), while also exhibiting lower toxicities for human embryonic kidney cells (HEK-293T cells). Median toxic concentrations (TC50) were 13-20-fold higher compared to auranofin indicating that they were less cytotoxic. The N-heterocyclic carbene analogs maybe well tolerated, but further evaluation is needed in vivo Finally, auranofin was synergistic with the antibiotic amoxicillin, suggesting that targeting both the reductive enzyme TrxR and cell wall synthesis may be effective against H. pylori infections. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

N- AND O-HETEROCYCLES PRODUCED FROM THE IRRADIATION OF BENZENE AND NAPHTHALENE IN H2O/NH3-CONTAINING ICES

International Nuclear Information System (INIS)

Materese, Christopher K.; Nuevo, Michel; Sandford, Scott A.

2015-01-01

Aromatic heterocyclic molecules are an important class of molecules of astrophysical and biological significance that include pyridine, pyrimidine, and their derivatives. Such compounds are believed to exist in interstellar and circumstellar environments, though they have never been observed in the gas phase. Regardless of their presence in the gas phase in space, numerous heterocycles have been reported in carbonaceous meteorites, which indicates that they are formed under astrophysical conditions. The experimental work described here shows that N- and O-heterocyclic molecules can form from the ultraviolet (UV) irradiation of the homocyclic aromatic molecules benzene (C 6 H 6 ) or naphthalene (C 10 H 8 ) mixed in ices containing H 2 O and NH 3 . This represents an alternative way to generate aromatic heterocycles to those considered before and may have important implications for astrochemistry and astrobiology

Activity of Antifungal Organobismuth(III Compounds Derived from Alkyl Aryl Ketones against S. cerevisiae: Comparison with a Heterocyclic Bismuth Scaffold Consisting of a Diphenyl Sulfone

Directory of Open Access Journals (Sweden)

Toshihiro Murafuji

2014-07-01

Full Text Available A series of hypervalent organobismuth(III compounds derived from alkyl aryl ketones [XBi(5-R'C6H3-2-COR(Ar] was synthesized to investigate the effect of the compounds’ structural features on their antifungal activity against the yeast Saccharomyces cerevisiae. In contrast to bismuth heterocycles [XBi(5-RC6H3-2-SO2C6H4-1'-] derived from diphenyl sulfones, a systematic quantitative structure-activity relationship study was possible. The activity depended on the Ar group and increased for heavier X atoms, whereas lengthening the alkyl chain (R or introducing a substituent (R' reduced the activity. IBi(C6H4-2-COCH3(4-FC6H4 was the most active. Its activity was superior to that of the related acyclic analogues ClBi[C6H4-2-CH2N(CH32](Ar and ClBi(C6H4-2-SO2 tert-Bu(Ar and also comparable to that of heterocyclic ClBi(C6H4-2-SO2C6H4-1'-, which was the most active compound in our previous studies. Density function theory calculations suggested that hypervalent bismuthanes undergo nucleophilic addition with a biomolecule at the bismuth atom to give an intermediate ate complex. For higher antifungal activity, adjusting the lipophilicity-hydrophilicity balance, modeling the three-dimensional molecular structure around the bismuth atom, and stabilizing the ate complex appear to be more important than tuning the Lewis acidity at the bismuth atom.

Degradação redutiva de azo-corantes utilizando-se ferro metálico Reductive degradation of azo-dyes by metallic iron

Directory of Open Access Journals (Sweden)

Cláudio Lima de Souza

2006-03-01

Full Text Available Corantes azo são extensivamente utilizados em processos de tingimento de fibras têxteis, sendo caracterizados por elevada resistência frente a processos aeróbios de biodegradação e, por conseqüência, persistência nos processos convencionais de tratamento de resíduos. Neste trabalho reporta-se a degradação redutiva de corantes azo, utilizando-se ferro metálico. Em condições experimentais otimizadas (pH 7 e 10 g de lã de aço comercial a completa descoloração do corante modelo (preto reativo 5 foi conseguida em um sistema contínuo, operando com tempos de retenção de 6 min. Nestas condições, o ferro solubilizado alcança concentrações compatíveis com os limites impostos pela atual legislação brasileira (12 mg L-1. Trata-se de um resultado bastante promissor, principalmente levando-se em consideração o caráter recalcitrante dos azo corantes e a simplicidade do sistema proposto.Azo dyes are extensively used in textile dying processes and are characterized by extreme resistance to biodegradation and consequently persistence during conventional wastewater treatment processes. In this work the reductive degradation of azo dyes was studied using zero-valent iron. At optimized experimental conditions (pH 7 and 10 g of commercial iron wool complete decolorization of the model dye (reactive black 5 was afforded in a continuous system operating with hydraulic retention time of 6 min. At these conditions the released total soluble iron reaches a concentration compatible with the limits imposed by the current Brazilian legislation (12 mg L-1. That is a very promising result, mainly taking into account the high recalcitrant character of azo dyes and the simplicity of the proposed system.

General and efficient one-pot synthesis of novel sugar/heterocyclic(aryl) 1,2-diketones from sugar terminal alkynes by Sonogashira/tetra-n- butylammonium permanganate oxidation.

Science.gov (United States)

Zhang, Fuyi; Wu, Xiaopei; Wang, Liming; Liu, Hong; Zhao, Yufen

2015-11-19

A new approach for one-pot synthesis of novel sugar/heterocyclic(aryl) 1,2-diketones has been achieved by the reaction of various sugar terminal alkynes with heterocyclic(aryl) iodides at room temperature. This one-pot protocol includes Sonogashira coupling and mild n-Bu4NMnO4 oxidation reaction. This method is mild, general and efficient. Fifty-six examples have been given and the sugar/heterocyclic(aryl) 1,2-diketones were obtained in 71-94% yields. The sugar terminal alkynes include 9 structurally different sugars in pyranose, furanose, and acyclic form which have various protecting groups, sensitive groups, and sterically bulky substituents. The heterocyclic(aryl) iodides include sterically bulky heterocyclic compounds and iodobenzenes with electron-donating, electron-neutral, and electron-withdrawing substituents. Copyright © 2015 Elsevier Ltd. All rights reserved.

Azo biphenyl polyurethane: Preparation, characterization and application for optical waveguide switch

Science.gov (United States)

Jiang, Yan; Da, Zulin; Qiu, Fengxian; Yang, Dongya; Guan, Yijun; Cao, Guorong

2018-01-01

Azo waveguide polymers are of particular interest in the design of materials for applications in optical switch. The aim of this contribution was the synthesis and thermo-optic waveguide switch properties of azo biphenyl polyurethanes. A series of monomers and azo biphenyl polyurethanes (Azo BPU1 and Azo BPU2) were synthesized and characterized by FT-IR, UV-Vis spectroscopy and 1H NMR. The physical and mechanical properties of thin polymer films were measured. The refractive index and thermo-optic coefficient (dn/dT) of polymer films were investigated for TE (transversal electric) polarizations by ATR technique. The transmission loss of film was measured using the Charge Coupled Device digital imaging devices. The results showed the Azo BPU2 containing chiral azobenzene chromophore had higher dn/dT and lower transmission loss. Subsequently, a 1 × 2 Y-branch and 2 × 2 Mach-Zehnder optical switches based on the prepared polymers were designed and simulated. The results showed that the power consumption of all switches was less than 1.0 mW. Compared with 1 × 2 Y-branch optical switch, the 2 × 2 Mach-Zehnder optical switches based on the same polymer have the faster response time, which were about only 1.2 and 2.0 ms, respectively.

Synthesis, Characterization and Photoinduction of Optical Anisotropy in Liquid Crystalline Diblock Azo-Copolymers

DEFF Research Database (Denmark)

Forcén, P; Oriol, L; Sánchez, C

2007-01-01

Diblock copolymers with polymethyl methacrylate and side chain liquid crystalline WC) azopolymethacrylate blocks were synthesized by atom transfer radical polymerization (ATRP). The azobeazene content in these copolymers ranges from 52 to 7 wt %. For an azo conteat dowri to 20% they exhibit a LC...... anisotropy induced in these films by illumination with linearly polarized 488 nm light was studied and the resuits compared with those of the azo homopolymer and of a random copolymer with a similar composition. The formation of azo aggregates inside the azo blocks is strongly reduced in going from...... the homopolymer to the copolymers. Photoinduced azo orientation perpendicular to the 488 nm light polarization was found in aH the polymers. The orientational order parameter is very similar in the homopolymer and in the block copolymers with an azo content down to 20 wt %, while it is much lower in the random...

Bacterial Degradation of Aromatic Compounds

Directory of Open Access Journals (Sweden)

Qing X. Li

2009-01-01

Full Text Available Aromatic compounds are among the most prevalent and persistent pollutants in the environment. Petroleum-contaminated soil and sediment commonly contain a mixture of polycyclic aromatic hydrocarbons (PAHs and heterocyclic aromatics. Aromatics derived from industrial activities often have functional groups such as alkyls, halogens and nitro groups. Biodegradation is a major mechanism of removal of organic pollutants from a contaminated site. This review focuses on bacterial degradation pathways of selected aromatic compounds. Catabolic pathways of naphthalene, fluorene, phenanthrene, fluoranthene, pyrene, and benzo[a]pyrene are described in detail. Bacterial catabolism of the heterocycles dibenzofuran, carbazole, dibenzothiophene, and dibenzodioxin is discussed. Bacterial catabolism of alkylated PAHs is summarized, followed by a brief discussion of proteomics and metabolomics as powerful tools for elucidation of biodegradation mechanisms.

Spatial distribution of heterocyclic organic matter compounds at macropore surfaces in Bt-horizons

Science.gov (United States)

Leue, Martin; Eckhardt, Kai-Uwe; Gerke, Horst H.; Ellerbrock, Ruth H.; Leinweber, Peter

2017-04-01

The illuvial Bt-horizon of Luvisols is characterized by coatings of clay and organic matter (OM) at the surfaces of cracks, biopores and inter-aggregate spaces. The OM composition of the coatings that originate from preferential transport of suspended matter in macropores determines the physico-chemical properties of the macropore surfaces. The analysis of the spatial distribution of specific OM components such as heterocyclic N-compounds (NCOMP) and benzonitrile and naphthalene (BN+NA) could enlighten the effect of macropore coatings on the transport of colloids and reactive solutes during preferential flow and on OM turnover processes in subsoils. The objective was to characterize the mm-to-cm scale spatial distribution of NCOMP and BN+NA at intact macropore surfaces from the Bt-horizons of two Luvisols developed on loess and glacial till. In material manually separated from macropore surfaces the proportions of NCOMP and BN+NA were determined by pyrolysis-field ionization mass spectrometry (Py-FIMS). These OM compounds, likely originating from combustion residues, were found increased in crack coatings and pinhole fillings but decreased in biopore walls (worm burrows and root channels). The Py-FIMS data were correlated with signals from C=O and C=C groups and with signals from O-H groups of clay minerals as determined by Fourier transform infrared spectroscopy in diffuse reflectance mode (DRIFT). Intensive signals of C15 to C17 alkanes from long-chain alkenes as main components of diesel and diesel exhaust particulates substantiated the assumption that burning residues were prominent in the subsoil OM. The spatial distribution of NCOMP and BN+NA along the macropores was predicted by partial least squares regression (PLSR) using DRIFT mapping spectra from intact surfaces and was found closely related to the distribution of crack coatings and pinholes. The results emphasize the importance of clay coatings in the subsoil to OM sorption and stabilization

Discovery and Characterization of Substituted Diphenyl Heterocyclic Compounds as Potent and Selective Inhibitors of Hepatitis C Virus Replication▿

Science.gov (United States)

Huang, Peiyong; Goff, Dane A.; Huang, Qi; Martinez, Anthony; Xu, Xiang; Crowder, Scott; Issakani, Sarkiz D.; Anderson, Emily; Sheng, Ning; Achacoso, Philip; Yen, Ann; Kinsella, Todd; Darwish, Ihab S.; Kolluri, Rao; Hong, Hui; Qu, Kunbin; Stauffer, Emily; Goldstein, Eileen; Singh, Rajinder; Payan, Donald G.; Lu, H. Henry

2008-01-01

A novel small-molecule inhibitor, referred to here as R706, was discovered in a high-throughput screen of chemical libraries against Huh-7-derived replicon cells carrying autonomously replicating subgenomic RNA of hepatitis C virus (HCV). R706 was highly potent in blocking HCV RNA replication as measured by real-time reverse transcription-PCR and Western blotting of R706-treated replicon cells. Structure-activity iterations of the R706 series yielded a lead compound, R803, that was more potent and highly specific for HCV replication, with no significant inhibitory activity against a panel of HCV-related positive-stranded RNA viruses. Furthermore, HCV genotype 1 replicons displayed markedly higher sensitivity to R803 treatment than a genotype 2a-derived replicon. In addition, R803 was tested by a panel of biochemical and cell-based assays for on-target and off-target activities, and the data suggested that the compound had a therapeutic window close to 100-fold, while its exact mechanism of action remained elusive. We found that R803 was more effective than alpha interferon (IFN-α) at blocking HCV RNA replication in the replicon model. In combination studies, R803 showed a weak synergistic effect with IFN-α/ribavirin but only additive effects with a protease inhibitor and an allosteric inhibitor of RNA-dependent RNA polymerase (20). We conclude that R803 and related heterocyclic compounds constitute a new class of HCV-specific inhibitors that could potentially be developed as a treatment for HCV infection. PMID:18227176

Solid‐Phase Synthesis of Structurally Diverse Heterocycles by an Amide–Ketone Condensation/N‐Acyliminium Pictet–Spengler Sequence

DEFF Research Database (Denmark)

Komnatnyy, Vitaly V.; Givskov, Michael Christian; Nielsen, Thomas Eiland

2012-01-01

An efficient approach for the solid‐phase synthesis of structurally diverse heterocyclic compounds is presented. Under acidic reaction conditions, peptidic levulinamides undergo intramolecular ketone–amide condensation reactions to form cyclic N‐acyliminium intermediates. In the presence...

Synthesis and stereochemical investigation of potential saturated heterocyclic drugs Pt. 1

International Nuclear Information System (INIS)

Bernath, G.

1982-01-01

Studies of partially and fully saturated heterocyclic compounds with condensed skeleton containing two heteroatoms are presented. The synthesis, stereochemical and conformation analyses aimed at the synthesis of potential drugs. Dihydro- and tetrahydro-1,3-oxazines were prepared from alicyclic 1,3-amino-alcohols by ring closure with aldehydes or imide esters. 1,3-oxazine-4-one derivatives were prepared by reacting alicyclic cis- and trans-2-hydroxy-1-carboxamides with aliphatic or aromatic aldehides. The conformations of the compounds prepared were determined by means of NMR spectroscopy. The main results of the determination of the steric structure of some representatives of the above described families of compounds by means of X-ray diffraction analysis are also presented. (author)

Synthesis, reactions and biological activity of some new bis-heterocyclic ring compounds containing sulphur atom

Science.gov (United States)

2013-01-01

Background The derivatives of thieno[2,3-b]thiophene belong to a significant category of heterocyclic compounds, which have shown a wide spectrum of medical and industrial application. Results A new building block with two electrophilic center of thieno[2,3-b]thiophene derivatives 2 has been reported by one-pot reaction of diketone derivative 1 with Br2/AcOH in excellent yield. A variety of heteroaromatics having bis(1H-imidazo[1,2a] benzimidazole), bis(1H-imidazo[1,2-b][1,2,4]triazole)-3-methyl-4-phenylthieno[2,3-b]thiophene derivatives, dioxazolo-, dithiazolo-, and 1H-imidazolo-3-methyl-4-phenylthieno[2,3-b]thiophene derivatives as well pyrrolo, thiazolo -3-methyl-4-phenylthieno[2,3-b]thiophene derivatives have been designed, synthesized, characterized, and evaluated for their biological activity. Compounds 3–9 showed good bioassay result. These new derivatives were evaluated for anti-cancer activity against PC-3 cell lines, in vitro antioxidant potential and β-glucuronidase and α-glucosidase inhibitory activities. Compound 3 (IC50 = 56.26 ± 3.18 μM) showed a potent DPPH radical scavenging antioxidant activity and found to be more active than standard N-acetylcystein (IC50 = 105.9 ± 1.1 μM). Compounds 8a (IC50 = 13.2 ± 0.34 μM) and 8b (IC50 = 14.1 ± 0.28 μM) found as potent inhibitor of α-glucusidase several fold more active than the standard acarbose (IC50 = 841 ± 1.73 μM). Most promising results were obtained in β-glucuronidase enzyme inhibition assay. Compounds 5 (IC50 = 0.13 ± 0.019 μM), 6 (IC50 = 19.9 ± 0.285 μM), 8a (IC50 = 1.2 ± 0.0785 μM) and 9 (IC50 = 0.003 ± 0.09 μM) showed a potent inhibition of β-glucuronidase. Compound 9 was found to be several hundred fold more active than standard D-Saccharic acid 1,4-lactone (IC50 = 45.75 ± 2.16 μM). Conclusions Synthesis, characterization, and in vitro biological activity of a series of

Anticancer Properties of an Important Drug Lead Podophyllotoxin Can Be Efficiently Mimicked by Diverse Heterocyclic Scaffolds Accessible via One-Step Synthesis

Science.gov (United States)

Magedov, Igor V.; Frolova, Liliya; Manpadi, Madhuri; Bhoga, Uma devi; Tang, Hong; Evdokimov, Nikolai M.; George, Olivia; Georgiou, Kathy Hadje; Renner, Steffen; Getlic, Matthäus; Kinnibrugh, Tiffany L.; Fernandes, Manuel A.; Van slambrouck, Severine; Steelant, Wim F. A.; Shuster, Charles B.; Rogelj, Snezna; van Otterlo, Willem A. L.; Kornienko, Alexander

2011-01-01

Structural simplification of an antimitotic natural product podophyllotoxin with mimetic heterocyclic scaffolds constructed using multicomponent reactions led to the identification of compounds exhibiting low nanomolar antiproliferative and apoptosis-inducing properties. The most potent compounds were found in the dihydropyridopyrazole, dihydropyridonaphthalene, dihydropyridoindole and dihydropyridopyrimidine scaffold series. Biochemical mechanistic studies performed with dihydropyridopyrazole compounds showed that these heterocycles inhibit in vitro tubulin polymerization and disrupt the formation of mitotic spindles in dividing cells at low nanomolar concentrations, in a manner similar to podophyllotoxin itself. Separation of a racemic dihydropyridonaphthalene into individual enantiomers demonstrated that only the optical antipode matching the absolute configuration of podophyllotoxin possessed potent anticancer activity. Computer modeling, performed using the podophyllotoxin binding site on beta-tubulin, provided a theoretical understanding of these successful experimental findings. PMID:21615090

Ion irradiation of AZO thin films for flexible electronics

Science.gov (United States)

Boscarino, Stefano; Torrisi, Giacomo; Crupi, Isodiana; Alberti, Alessandra; Mirabella, Salvatore; Ruffino, Francesco; Terrasi, Antonio

2017-02-01

Aluminum doped Zinc oxide (AZO) is a promising transparent conductor for solar cells, displays and touch-screen technologies. The resistivity of AZO is typically improved by thermal annealing at temperatures not suitable for plastic substrates. Here we present a non-thermal route to improve the electrical and structural properties of AZO by irradiating the TCO films with O+ or Ar+ ion beams (30-350 keV, 3 × 1015-3 × 1016 ions/cm2) after the deposition on glass and flexible polyethylene naphthalate (PEN). X-ray diffraction, optical absorption, electrical measurements, Rutherford Backscattering Spectrometry and Atomic Force Microscopy evidenced an increase of the crystalline grain size and a complete relief of the lattice strain upon ion beam irradiation. Indeed, the resistivity of thin AZO films irradiated at room temperature decreased of two orders of magnitude, similarly to a thermal annealing at 400 °C. We also show that the improvement of the electrical properties does not simply depend on the strain or polycrystalline domain size, as often stated in the literature.

Condensed heterocycles with a thiazole ring. 13. Azinothiazoloquinoxalinium salts

International Nuclear Information System (INIS)

Nesterenko, Yu.A.; Romanov, N.N.

1987-01-01

The condensation of 2,3-dichloroquinoxaline with 2-mercaptopyridines and 2-mercaptoquinolines gave the corresponding derivatives of new heterocyclic systems, viz., azino[1',2':3,2]thaizolo[4,5-b]quinoxalinium salts, which can be used for the synthesis of cyanine dyes. The electronic spectra of solutions of the compounds were obtained with an SF-8 spectrophotometer. The PMR spectra of solutions of CF 3 COOD were recorded with a BS-467 spectrometer (60 MHz) with hexamethyldisiloxane (HMDS) as the external standard

[Synthetic Studies of Bioactive Heterocyclic Natural Products and Fused Heterocyclic Compounds Based on the Thermal Electrocyclic or Azaelectocyclic Reaction of 6π-Electron or Aza-6π-electron Systems].

Science.gov (United States)

Hibino, Satoshi

2016-01-01

Since 1979, synthetic studies of bioactive heterocyclic natural products and condensed heteroaromatic compounds based on the thermal electrocyclic reaction of 6π-electron or aza-6π-electron systems incorporating the double bond of the principal aromatic or heteroaromatic ring have been conducted by our research group. In this review, five types of electrocyclic and azaelectrocyclic reaction are described: 1) the synthesis of the carbazole alkaloids hyellazole and 6-chlorohyellazole through the electrocyclic reaction of 2,3-bisalkenylindoles; 2) synthetic studies of the pyridocarbazole alkaloids ellipticine and olivacine through the electrocyclic reactions of the indole-2,3- and pyridine-3,4-quinodimethane intermediates; 3) synthetic studies of polysubstituted carbazole alkaloids through the allene-mediated electrocyclic reactions involving the indole 2,3-bond; 4) synthetic studies of fused pyridine rings through the azaelectrocyclic reaction of the 1-aza-6π-electron system using the oxime or oxime ether; and 5) synthetic studies of fused pyridine rings through the azaelectrocyclic reaction of the 2-aza-6π-electron system using a carbodiimide or isocyanate.

Petroleum geochemistry of the Potwar Basin, Pakistan: II – Oil classification based on heterocyclic and polycyclic aromatic hydrocarbons

International Nuclear Information System (INIS)

Asif, Muhammad; Fazeelat, Tahira

2012-01-01

In a previous study, oils in the Potwar Basin (Upper Indus) of Pakistan were correlated based on the dissimilarity of source and depositional environment of organic matter (OM) using biomarkers and bulk stable isotopes. This study is aimed at supporting the classification of Potwar Basin oils into three groups (A, B and C) using the distribution of alkylnaphthalenes, alkylphenanthrenes, alkyldibenzothiophenes, alkyldibenzofurans, alkylfluorenes, alkylbiphenyls, triaromatic steroids, methyl triaromatic steroids, retene, methyl retenes and cadalene. The higher relative abundance of specific methyl isomers of naphthalene and phenanthrene and the presence of diagnostic aromatic biomarkers clearly indicate the terrigenous and oxic depositional environment of OM for group A oil. Group B and C oils are of marine origin and the aforementioned heterocyclic and polycyclic aromatic hydrocarbons (HCs) differentiate them clearly into two different groups. The relative percentages of heterocyclic aromatic HCs reveal that the distribution of these compounds is controlled by the depositional environment of the OM. Sulfur-containing heterocyclic aromatic HCs are higher in crude oils generated from source rocks deposited in suboxic depositional environments, while oxygen-containing heterocyclic aromatic HCs in combination with alkylfluorenes are higher in marine oxic and deltaic oils. Biomarker and aromatic HC parameters do not indicate significant differences in the thermal maturity of Potwar Basin oils. Triaromatic and methyl triaromatic steroids support the division of Potwar Basin oils into the three groups and their relative abundances are related to source OM rather than thermal maturity. Significantly higher amounts of C 20 and C 21 triaromtic steroids and the presence or absence of long chain triaromatic steroids (C 25 , C 26 , C 27 , and C 28 ) indicates that these compounds are probably formed from different biological precursors in each group. Different isomers of methyl

Enhanced optical and electrical properties of Ni inserted ITO/Ni/AZO tri-layer structure for photoelectric applications

Energy Technology Data Exchange (ETDEWEB)

Kumar, M. Melvin David; Kim, Hyunki [Department of Electrical Engineering, Incheon National University, Incheon 406772 (Korea, Republic of); Park, Yun Chang [Measurement and Analysis Division, National Nanofab Center (NNFC), Daejeon 305-806 (Korea, Republic of); Kim, Joondong, E-mail: joonkim@incheon.ac.kr [Department of Electrical Engineering, Incheon National University, Incheon 406772 (Korea, Republic of)

2015-05-15

Highlights: • Ni-embedding transparent conductor effectively reduces the resistivity. • Ni insertion improves the carrier mobility and collection efficiencies. • ITO/Ni/AZO is effective to improve photo-responses compared to ITO/AZO. - Abstract: A thin Ni layer of 5 nm thickness was deposited in between indium-tin-oxide (ITO) and aluminum-doped-zinc oxide (AZO) layers of 50 nm thickness each. The Ni inserting tri-layer structure (ITO/Ni/AZO) showed lower resistivity of 5.51 × 10{sup −4} Ωcm which is nearly 20 times lesser than 97.9 × 10{sup −4} Ωcm of bilayer structure (ITO/AZO). A thin Ni layer in between ITO and AZO enhanced the carrier concentration, mobility and photoresponse behaviors so that figure of merit (FOM) value of ITO/Ni/AZO device was greater than that of ITO/AZO device. ITO/Ni/AZO structure showed improved quantum efficiencies over a broad range of wavelengths (∼350–950 nm) compared to that of ITO/AZO bilayer structure, resulting in enhanced photoresponses. These results show that the optical, electrical and photoresponse properties of ITO/AZO structure could be enhanced by inserting Ni layer of 5 nm thickness in between ITO and AZO layers.

Assembly of Four Diverse Heterocyclic Libraries Enabled by Prins Cyclization, Au-Catalyzed Enyne Cycloisomerization, and Automated Amide Synthesis

Science.gov (United States)

Cui, Jiayue; Chai, David I.; Miller, Christopher; Hao, Jason; Thomas, Christopher; Wang, JingQi; Scheidt, Karl A.; Kozmin, Sergey A.

2013-01-01

We describe a unified synthetic strategy for efficient assembly of four new heterocyclic libraries. The synthesis began by creating a range of structurally diverse pyrrolidinones or piperidinones. Such compounds were obtained in a simple one-flask operation starting with readily available amines, ketoesters, and unsaturated anhydrides. The use of tetrahydropyran-containing ketoesters, which were rapidly assembled by our Prins cyclization protocol, enabled efficient fusion of pyran and piperidinone cores. A newly developed Au(I)-catalyzed cycloisomerization of alkyne-containing enamides further expanded heterocyclic diversity by providing rapid entry into a wide range of bicyclic and tricyclic dienamides. The final stage of the process entailed diversification of each of the initially produced carboxylic acids using a fully automated platform for amide synthesis, which delivered 1872 compounds in high diastereomeric and chemical purity. PMID:22860634

Exploring the novel heterocyclic derivatives as lead molecules for design and development of potent anticancer agents.

Science.gov (United States)

Azad, Iqbal; Nasibullah, Malik; Khan, Tahmeena; Hassan, Firoj; Akhter, Yusuf

2018-05-01

This paper deals with in silico evaluation of newly proposed heterocyclic derivatives in search of potential anticancer activity. Best possible drug candidates have been proposed using a rational approach employing a pipeline of computational techniques namely MetaPrint2D prediction, molinspiration, cheminformatics, Osiris Data warrior, AutoDock and iGEMDOCK. Lazar toxicity prediction, AdmetSAR predictions, and targeted docking studies were also performed. 27 heterocyclic derivatives were selected for bioactivity prediction and drug likeness score on the basis of Lipinski's rule, Viber rule, Ghose filter, leadlikeness and Pan Assay Interference Compounds (PAINS) rule. Bufuralol, Sunitinib, and Doxorubicin were selected as reference standard drug for the comparison of molecular descriptors and docking. Bufuralol is a known non-selective adreno-receptor blocking agent. Studies showed that beta blockers are also used against different types of cancers. Sunitinib is well known Food and Drug administration (FDA) approved pyrrole containing tyrosine kinase inhibitor and our proposed molecules possess similarities with both drug and doxorubicin is another moiety having anticancer activity. All heterocyclic derivatives were found to obey the drug filters except standard drug Doxorubicin. Bioactivity score of the compounds was predicted for drug targets including enzymes, nuclear receptors, kinase inhibitors, G protein-coupled receptor (GPCR) ligands and ion channel modulators. Absorption, distribution, metabolism and toxicity (ADMET) prediction of all proposed compound showed good Blood-brain barrier (BBB) penetration, Human intestinal absorption (HIA), Caco-2 cell permeability except compound-11 and was found to have no AdmetSAR toxicity as well as carcinogenic effect. Compounds 1-9 were slightly mutagenic while compound 2, 11, 20 and 21 showed carcinogenic effect according to Lazar toxicity prediction. Rests of the compounds were predicted to have no side effect

Single-catalyst high-weight% hydrogen storage in an N-heterocycle synthesized from lignin hydrogenolysis products and ammonia.

Science.gov (United States)

Forberg, Daniel; Schwob, Tobias; Zaheer, Muhammad; Friedrich, Martin; Miyajima, Nobuyoshi; Kempe, Rhett

2016-10-20

Large-scale energy storage and the utilization of biomass as a sustainable carbon source are global challenges of this century. The reversible storage of hydrogen covalently bound in chemical compounds is a particularly promising energy storage technology. For this, compounds that can be sustainably synthesized and that permit high-weight% hydrogen storage would be highly desirable. Herein, we report that catalytically modified lignin, an indigestible, abundantly available and hitherto barely used biomass, can be harnessed to reversibly store hydrogen. A novel reusable bimetallic catalyst has been developed, which is able to hydrogenate and dehydrogenate N-heterocycles most efficiently. Furthermore, a particular N-heterocycle has been identified that can be synthesized catalytically in one step from the main lignin hydrogenolysis product and ammonia, and in which the new bimetallic catalyst allows multiple cycles of high-weight% hydrogen storage.

N- AND O-HETEROCYCLES PRODUCED FROM THE IRRADIATION OF BENZENE AND NAPHTHALENE IN H{sub 2}O/NH{sub 3}-CONTAINING ICES

Energy Technology Data Exchange (ETDEWEB)

Materese, Christopher K.; Nuevo, Michel; Sandford, Scott A., E-mail: christopher.k.materese@nasa.gov [NASA Ames Research Center, Moffett Field, CA 94035 (United States)

2015-02-20

Aromatic heterocyclic molecules are an important class of molecules of astrophysical and biological significance that include pyridine, pyrimidine, and their derivatives. Such compounds are believed to exist in interstellar and circumstellar environments, though they have never been observed in the gas phase. Regardless of their presence in the gas phase in space, numerous heterocycles have been reported in carbonaceous meteorites, which indicates that they are formed under astrophysical conditions. The experimental work described here shows that N- and O-heterocyclic molecules can form from the ultraviolet (UV) irradiation of the homocyclic aromatic molecules benzene (C{sub 6}H{sub 6}) or naphthalene (C{sub 10}H{sub 8}) mixed in ices containing H{sub 2}O and NH{sub 3}. This represents an alternative way to generate aromatic heterocycles to those considered before and may have important implications for astrochemistry and astrobiology.

Auspicious role of the steroidal heterocyclic derivatives as a platform for anti-cancer drugs.

Science.gov (United States)

Tantawy, Mohamed A; Nafie, Mohamed S; Elmegeed, Gamal A; Ali, Ibrahim A I

2017-08-01

Steroids are polycyclic compounds that have a wide range of biological activities. They are bio-synthesized from cholesterol through a series of enzyme-mediated transformations, so they are highly lipophilic and readily enter most cells to interact with intracellular receptors, making them ideal vehicles for targeting a broad array of pathologies. New curative agents for cancers have been developed from several steroidal derivatives. Some biologically important properties of modified steroids are dependent on structural features of the steroid moiety and their side chains. Therefore, chemical derivatization of steroids provides a way to modify their function, and many structure-activity relationships have been confirmed by such synthetic modifications. Several studies demonstrate that steroidal heterocyclic derivatives can be effective in the prevention and treatment of many types of hormone-dependent cancers. The present review is a concise report on steroidal heterocyclic derivatives, with special emphasis on steroid heterocyclic derivatives with 5 membered rings or six-membered rings having interesting therapeutic potential as enzyme inhibitors and cytotoxic drugs to be used as candidates for anti-cancer drug development. Copyright © 2017 Elsevier Inc. All rights reserved.

Optimized Syntheses of Cyclopentadienyl Nickel Chloride Compounds Containing "N"-Heterocyclic Carbene Ligands for Short Laboratory Periods

Science.gov (United States)

Cooke, Jason; Lightbody, Owen C.

2011-01-01

Experiments are described for the preparation of imidazolium chloride precursors to "N"-heterocyclic carbenes and their cyclopentadienyl nickel chloride derivatives. The syntheses have been optimized for second- and third-year undergraduate laboratories that have a maximum programmed length of three hours per week. The experiments are flexible and…

Biological Screening of Newly Synthesized BIAN N-Heterocyclic Gold Carbene Complexes in Zebrafish Embryos

Science.gov (United States)

Farooq, Muhammad; Abu Taha, Nael; Butorac, Rachel R.; Evans, Daniel Anthony; Elzatahry, Ahmed A.; Elsayed, Elsayed Ahmed; Wadaan, Mohammad A. M.; Al-Deyab, Salem S.; Cowley, Alan H.

2015-01-01

N-Heterocyclic carbene (NHC) metal complexes possess diverse biological activities but have yet to be extensively explored as potential chemotherapeutic agents. We have previously reported the synthesis of a new class of NHC metal complexes N-heterocyclic with acetate [IPr(BIAN)AuOAc] and chloride [IPr(BIAN)AuCl] ligands. In the experiments reported herein, the zebrafish embryos were exposed to serial dilutions of each of these complexes for 10–12 h. One hundred percent mortality was observed at concentrations ≥50 µM. At sub-lethal concentrations (10–30 µM), both compounds influenced zebrafish embryonic development. However, quite diverse categories of abnormalities were found in exposed embryos with each compound. Severe brain deformation and notochord degeneration were evident in the case of [IPr(BIAN)AuOAc]. The zebrafish embryos treated with [IPr(BIAN)AuCl] exhibited stunted growth and consequently had smaller body sizes. A depletion of 30%–40% glutathione was detected in the treated embryos, which could account for one of the possible mechanism of neurotoxicity. The fact that these compounds are capable of both affecting the growth and also compromising antioxidant systems by elevating intracellular ROS production implies that they could play an important role as a new breed of therapeutic molecules. PMID:26501273

Aspects and prospects of the chemistry of organic heterocycles (review)

International Nuclear Information System (INIS)

Schroth, W.

1986-01-01

The systematics of heterocycles, their place in organic chemistry, and their significance for theory and practice are discussed. Problems of the chemistry of heterocycles are discussed on the examples of systems with various types of conjugation and ring sizes. The focus is on the principles of synthesis of heterocycles, in particular, those based on acetylene, various C 3 fragments, carbon disulfide, and maleic anhydride. Individual sections of the survey are devoted to the role of heterocycles in biosynthesis, as well as certain problems common to the chemistry of heterocycles, biochemistry, and macromolecular chemistry

Crystal and molecular structure of three molybdenum (6) dioxocomplexes with heterocyclic hydrazones

International Nuclear Information System (INIS)

Ilyukhin, A.B.; Sergienko, V.S.

1994-01-01

The X-ray diffraction investigation into three Mo(6) dioxocomplexes with heterocyclic hydrazones has been made. In all compounds the Mo atom has a deformed octahedral coordination by two O atoms of cis-dioxogroups, N atoms (azomethane), N (heterocyclie), O (phenol) of tridentate organic ligand. Sixth position in Mo coordination octahedron is due to O atom of methanol solvated molecule in the 1,3 structures or N atom of γ-picoline molecule in the 2 structure. The packing of structural units in the crystals of the 1-3 compounds is under consideration. 12 refs., 5 figs., 3 tabs

Organic heterostructures deposited by MAPLE on AZO substrate

Science.gov (United States)

Socol, M.; Preda, N.; Stanculescu, A.; Breazu, C.; Florica, C.; Stanculescu, F.; Iftimie, S.; Girtan, M.; Popescu-Pelin, G.; Socol, G.

2017-09-01

Organic heterostructures based on poly(3-hexylthiophene) (P3HT) and fullerene (C60) as blends or multilayer were deposited on Al:ZnO (AZO) by Matrix-Assisted Pulsed Laser Evaporation (MAPLE) technique. The AZO layers were obtained by Pulsed Laser Deposition (PLD) on glass substrate, the high quality of the films being reflected by the calculated figure of merit. The organic heterostructures were investigated from morphological, optical and electrical point of view by atomic force microscopy (AFM), UV-vis spectroscopy, photoluminescence (PL) and current-voltage (I-V) measurements, respectively. The increase of the C60 content in the blend heterostructure has as result a high roughness. Compared with the multilayer heterostructure, those based on blends present an improvement in the electrical properties. Under illumination, the highest current value was recorded for the heterostructure based on the blend with the higher C60 amount. The obtained results showed that MAPLE is a useful technique for the deposition of the organic heterostructures on AZO as transparent conductor electrode.

FIA-Spectrophotometric Method for Determination of Nitrite in Meat Products: An Experiment Exploring Color Reduction of an Azo-Compound

Science.gov (United States)

Penteado, Jose C.; Angnes, Lucio; Masini, Jorge C.; Oliveira, Paulo C. C.

2005-01-01

This article describes the reaction between nitrite and safranine O. This sensitive reaction is based on the disappearance of color of the reddish-orange azo dye, allowing the determination of nitrite at the mg mL-1 level. A factorial optimization of parameters was carried out and the method was applied for the quantification of nitrite in…

A Novel Superfamily of Transporters for Allantoin and Other Oxo Derivatives of Nitrogen Heterocyclic Compounds in Arabidopsis

Science.gov (United States)

Desimone, Marcelo; Catoni, Elisabetta; Ludewig, Uwe; Hilpert, Melanie; Schneider, Anja; Kunze, Reinhard; Tegeder, Mechthild; Frommer, Wolf Bernd; Schumacher, Karin

2002-01-01

A wide spectrum of soil heterocyclic nitrogen compounds are potential nutrients for plants. Here, it is shown that Arabidopsis plants are able to use allantoin as sole nitrogen source. By functional complementation of a yeast mutant defective in allantoin uptake, an Arabidopsis transporter, AtUPS1 (Arabidopsis thaliana ureide permease 1), was identified. AtUPS1 belongs to a novel superfamily of plant membrane proteins with five open reading frames in Arabidopsis (identity, 64 to 82%). UPS proteins have 10 putative transmembrane domains with a large cytosolic central domain containing a “Walker A” motif. Transport of 14C-labeled allantoin by AtUPS1 in yeast exhibited saturation kinetics (Km ∼ 52 μM), was dependent on Glc and a proton gradient, and was stimulated by acidic pH. AtUPS1 transports uric acid and xanthine, besides allantoin, but not adenine. Protons are cosubstrates in allantoin transport by AtUPS1, as demonstrated by expression in Xenopus laevis oocytes. In plants, AtUPS1 gene expression was dependent on the nitrogen source. Therefore, AtUPS1 presumably is involved in the uptake of allantoin and other purine degradation products when primary sources are limiting. PMID:11971139

Ordered ZnO/AZO/PAM nanowire arrays prepared by seed-layer-assisted electrochemical deposition

International Nuclear Information System (INIS)

Shen, Yu-Min; Pan, Chih-Huang; Wang, Sheng-Chang; Huang, Jow-Lay

2011-01-01

An Al-doped ZnO (AZO) seed layer is prepared on the back side of a porous alumina membrane (PAM) substrate by spin coating followed by annealing in a vacuum at 400 °C. Zinc oxide in ordered arrays mediated by a high aspect ratio and an ordered pore array of AZO/PAM is synthesized. The ZnO nanowire array is prepared via a 3-electrode electrochemical deposition process using ZnSO 4 and H 2 O 2 solutions at a potential of − 1 V (versus saturated calomel electrode) and temperatures of 65 and 80 °C. The microstructure and chemical composition of the AZO seed layer and ZnO/AZO/PAM nanowire arrays are characterized by field emission scanning electron microscopy (FE-SEM), high-resolution transmission electron microscopy (HR-TEM), and energy-dispersive X-ray spectroscopy (EDS). Results indicate that the ZnO/AZO/PAM nanowire arrays were assembled in the nanochannel of the porous alumina template with diameters of 110–140 nm. The crystallinity of the ZnO nanowires depends on the AZO seed layer during the annealing process. The nucleation and growth process of ZnO/AZO/PAM nanowires are interpreted by the seed-layer-assisted growth mechanism.

The effect of lactate unit number in compounds with azo group in the molecular core

Czech Academy of Sciences Publication Activity Database

Novotná, Vladimíra; Hamplová, Věra; Kašpar, Miroslav; Podoliak, Natalia; Bubnov, Alexej; Glogarová, Milada; Nonnenmacher, D.; Giesselmann, F.

2011-01-01

Roč. 38, č. 5 (2011), s. 649-655 ISSN 0267-8292 R&D Projects: GA AV ČR IAA100100911; GA AV ČR(CZ) GA202/09/0047; GA ČR(CZ) GAP204/11/0723 Grant - others:RFASI(RU) 02.740.11.5166; Společný projekt AV ČR-DAAD SNR(CZ) D4-CZ5/2010-2011; GA UK(CZ) SVV-2011-263303 Institutional research plan: CEZ:AV0Z10100520 Keywords : liquid crystals * ferroelectricity * chirality * azo group * antiferroelectricity Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.858, year: 2011 http://dx.doi.org/10.1080/02678292.2011.565426

Titanocene–Gold Complexes Containing N-Heterocyclic Carbene Ligands Inhibit Growth of Prostate, Renal, and Colon Cancers in Vitro

Science.gov (United States)

2016-01-01

We report on the synthesis, characterization, and stability studies of new titanocene complexes containing a methyl group and a carboxylate ligand (mba = −OC(O)-p-C6H4-S−) bound to gold(I)–N-heterocyclic carbene fragments through the thiolate group: [(η5-C5H5)2TiMe(μ-mba)Au(NHC)]. The cytotoxicities of the heterometallic compounds along with those of novel monometallic gold–N-heterocyclic carbene precursors [(NHC)Au(mbaH)] have been evaluated against renal, prostate, colon, and breast cancer cell lines. The highest activity and selectivity and a synergistic effect of the resulting heterometallic species was found for the prostate and colon cancer cell lines. The colocalization of both titanium and gold metals (1:1 ratio) in PC3 prostate cancer cells was demonstrated for the selected compound 5a, indicating the robustness of the heterometallic compound in vitro. We describe here preliminary mechanistic data involving studies on the interaction of selected mono- and bimetallic compounds with plasmid (pBR322) used as a model nucleic acid and the inhibition of thioredoxin reductase in PC3 prostate cancer cells. The heterometallic compounds, which are highly apoptotic, exhibit strong antimigratory effects on the prostate cancer cell line PC3. PMID:27182101

Generation of N-Heterocycles via Tandem Reactions of N '-(2-Alkynylbenzylidene)hydrazides.

Science.gov (United States)

Qiu, Guanyinsheng; Wu, Jie

2016-02-01

As a powerful synthon, N '-(2-alkynylbenzylidene)hydrazides have been utilized efficiently for the construction of N-heterocycles. Since N '-(2-alkynylbenzylidene)hydrazides can easily undergo intramolecular 6-endo cyclization promoted by silver triflate or electrophiles, the resulting isoquinolinium-2-yl amides can proceed through subsequent transformations including [3 + 2] cycloaddition, nucleophilic addition, and [3 + 3] cycloaddition. Several unexpected rearrangements via radical processes were observed in some cases, which afforded nitrogen-containing heterocycles with molecular complexity. Reactive partners including internal alkynes, arynes, ketenimines, ketenes, allenoates, and activated alkenes reacted through [3 + 2] cycloaddition and subsequent aromatization, leading to diverse H-pyrazolo[5,1-a]isoquinolines with high efficiency. Nucleophilic addition to the in situ generated isoquinolinium-2-yl amide followed by aromatization also produced H-pyrazolo[5,1-a]isoquinoline derivatives when terminal alkynes, carbonyls, enamines, and activated methylene compounds were used as nucleophiles. Isoquinoline derivatives were obtained when indoles or phosphites were employed as nucleophiles in the reactions of N '-(2-alkynylbenzylidene)hydrazides. A tandem 6-endo cyclization and [3 + 3] cycloaddition of cyclopropane-1,1-dicarboxylates with N '-(2-alkynylbenzylidene)hydrazides was observed as well. Small libraries of these compounds were constructed. Biological evaluation suggested that some compounds showed promising activities for inhibition of CDC25B, TC-PTP, HCT-116, and PTP1B. © 2015 The Chemical Society of Japan & Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Flavor and taste compounds analysis in Chinese solid fermented ...

African Journals Online (AJOL)

A total of 82 kinds of volatile compounds were identified, including alcohols, acids, esters, aldehydes, ketones, phenols, heterocyclic compounds, alkynes and benzenes. The subtle aroma of the soy sauce seemed to depend not only on particular key compounds but also on a “critical balance” or a “weighted concentration

Kappa-receptor selective binding of opioid ligands with a heterocyclic bicyclo[3.3.1]nonan-9-one structure.

Science.gov (United States)

Benyhe, S; Márki, A; Nachtsheim, Corina; Holzgrabe, Ulrike; Borsodi, Anna

2003-01-01

Previous pharmacological results have suggested that members of the heterocyclic bicyclo[3.3.1]nonan-9-one-like compounds are potent kappa-opioid receptor specific agonists. One lead molecule of this series. called compound 1 (dimethyl 7-methyl-2,4-di-2-pyridyl-3.7-diazabicyclo[3.3.1]nonan-9-one-1,5-dicarboxylate) exhibited high affinity for [3H]ethylketocyclazocine and [3H]U-69.593 binding sites in guinea pig cerebellar membranes which known to be a good source for kappa1 receptors. It was shown by molecular modelling that heterocyclic bicyclo[3.3.1]nonan-9-ones fit very well with the structure of ketazocine, a prototypic kappa-selective benzomorphan compound; when compared to the arylacetamide structure of U-69.593, a specific kappa1-receptor agonist, a similar geometry was found with a slightly different distribution of the charges. It is postulated, that the essential structural skeleton involved in the opioid activity is an aryl-propyl-amine element distributed along the N7-C6-C5-C4-aryl bonds.

Direct Functionalization of Nitrogen Heterocycles via Rh-Catalyzed C-H Bond Activation

Energy Technology Data Exchange (ETDEWEB)

Lewis, Jared; Bergman, Robert; Ellman, Jonathan

2008-02-04

Nitrogen heterocycles are present in many compounds of enormous practical importance, ranging from pharmaceutical agents and biological probes to electroactive materials. Direct funtionalization of nitrogen heterocycles through C-H bond activation constitutes a powerful means of regioselectively introducing a variety of substituents with diverse functional groups onto the heterocycle scaffold. Working together, our two groups have developed a family of Rh-catalyzed heterocycle alkylation and arylation reactions that are notable for their high level of functional-group compatibility. This Account describes their work in this area, emphasizing the relevant mechanistic insights that enabled synthetic advances and distinguished the resulting transformations from other methods. They initially discovered an intramolecular Rh-catalyzed C-2-alkylation of azoles by alkenyl groups. That reaction provided access to a number of di-, tri-, and tetracyclic azole derivatives. They then developed conditions that exploited microwave heating to expedite these reactions. While investigating the mechanism of this transformation, they discovered that a novel substrate-derived Rh-N-heterocyclic carbene (NHC) complex was involved as an intermediate. They then synthesized analogous Rh-NHC complexes directly by treating precursors to the intermediate [RhCl(PCy{sub 3}){sub 2}] with N-methylbenzimidazole, 3-methyl-3,4-dihydroquinazolein, and 1-methyl-1,4-benzodiazepine-2-one. Extensive kinetic analysis and DFT calculations supported a mechanism for carbene formation in which the catalytically active RhCl(PCy{sub 3}){sub 2} fragment coordinates to the heterocycle before intramolecular activation of the C-H bond occurs. The resulting Rh-H intermediate ultimately tautomerizes to the observed carbene complex. With this mechanistic information and the discovery that acid co-catalysts accelerate the alkylation, they developed conditions that efficiently and intermolecularly alkylate a variety of

Decolourization and degradation of azo Dye, Synozol Red HF6BN ...

African Journals Online (AJOL)

Decolourization and degradation of azo Dye, Synozol Red HF6BN, by Pleurotus ostreatus. Sidra Ilyas, Skinder Sultan Sultan, Abdul Rehman. Abstract. The present paper focuses on the use of fungus, Pleurotus ostreatus, to decolorize and degrade azo dye, Synazol Red HF6BN. Decolorization study showed that P.

Quantitative LC–MS for water-soluble heterocyclic amines in fine aerosols (PM2.5) at Duke Forest, USA

Science.gov (United States)

In this study, a quantitative liquid chromatography-mass spectrometry (LC-MS) technique capable of measuring the concentrations of heterocyclic nitrogen compounds in ambient fine aerosols (PM2.5) has been developed. Quadrupole time-of-flight (Q-TOF) MS technology is used to provi...

N-heterocyclic carbene complexes of silver and gold as novel tools against breast cancer progression.

Science.gov (United States)

Saturnino, Carmela; Barone, Ines; Iacopetta, Domenico; Mariconda, Annaluisa; Sinicropi, Maria Stefania; Rosano, Camillo; Campana, Antonella; Catalano, Stefania; Longo, Pasquale; Andò, Sebastiano

2016-12-01

Metal carbenic complexes have received considerable attention in both the catalysis and biological fields for their potential applications in cancer and antimicrobial therapies. A small series of new silver and gold N-heterocyclic carbene complexes has been designed and synthesized. Among the tested complexes, one compound was particularly active in inhibiting anchorage-dependent and -independent breast cancer proliferation, and inducing cell apoptosis via a mitochondria-related process. The antitumor activity was associated to the transcriptional activation of the tumor suppressor gene p53 in an Sp1-dependent manner, as evidenced by biological and docking studies. Our results highlight the importance and the versatility of N-heterocyclic carbene complexes of gold and silver as useful tools against breast cancer progression.

An electrochemical procedure coupled with a Schiff base method; application to electroorganic synthesis of new nitrogen-containing heterocycles

International Nuclear Information System (INIS)

Dowlati, Bahram; Othman, Mohamed Rozali

2013-01-01

The synthesis of Nitrogen-containing heterocycles has been achieved using chemical and electrochemical methods, respectively. The direct chemical synthesis of nucleophiles proceeds through the Schiff base chemical reaction. This procedure offers an alternate reaction between dicarbonyl compounds and diamines leads to the formation of products. The results indicate that the Schiff base chemical method for synthesis of the product has successfully performed in excellent overall yield. In the electrochemical step, a series of Nitrogen-containing compounds were electrosynthesized. Various parameters such as the applied potential, pH of the electrolytic solution, cell configuration and also purification techniques, were carried out to optimize the yields of corresponding products. New Nitrogen-containing heterocycle derivatives were synthesized using an electrochemical procedure coupled with a Schiff base as a facile, efficient and practical method. The products have been characterized after purification by IR, 1 H NMR, 13 C NMR and ESI-MS 2

Evaluation of biodecolorization of the textile azo dye by halophilic archaea

Directory of Open Access Journals (Sweden)

Masoomeh Selseleh Hassan-Kiadehi

2017-09-01

Discussion and conclusion: In conclusion, our results indicate that halophilic archaea have very high potential to decolorize azo dyes. Regarding high amounts of salts in textile wastewaters, using such microorganisms which can tolerate the harsh environment in order to decolorize azo dyes, could be a new approach in this field.

Oxidation using quaternary ammonium polyhalides VII. Oxidation of primary amines and hydrazo compounds by use of benzyltrimethylammonium tribromide

OpenAIRE

Nishida, Akiko; Kohro, Noriaki; Fujisaki, Shizuo; Kajigaeshi, Shoji

1990-01-01

The reactions of primary amines and hydrazo compounds with benzyltrimethylammonium tribromide in aqueous sodium hydroxide or in water gave the corresponding nitriles and azo compounds in satisfactory yields, respectively.

Steroidal[17,16-d]pyrimidines derived from dehydroepiandrosterone: A convenient synthesis, antiproliferation activity, structure-activity relationships, and role of heterocyclic moiety

Science.gov (United States)

Ke, Shaoyong; Shi, Liqiao; Zhang, Zhigang; Yang, Ziwen

2017-01-01

A series of steroidal[17,16-d]pyrimidines derived from dehydroepiandrosterone were designed and prepared by a convenient heterocyclization reaction. The in vitro anticancer activities for these obtained compounds were evaluated against human cancer cell lines (HepG2, Huh-7, and SGC-7901), which demonstrated that some of these heterocyclic pyrimidine derivatives exhibited significantly good cytotoxic activities against all tested cell lines compared with 5-fluorouracil (5-FU), especially, compound 3b exhibited high potential growth inhibitory activities against all tested cell lines with the IC50 values of 5.41 ± 1.34, 5.65 ± 1.02 and 10.64 ± 1.49 μM, respectively, which might be used as promising lead scaffold for discovery of novel anticancer agents. PMID:28290501

Inhibitory action of an heterocyclic organic compound containing amine group for copper corrosion in 5,0 M nitric acid solution

Energy Technology Data Exchange (ETDEWEB)

El-Naggar, M.M.; Abdallah, M. [Benha Univ., Benha (Egypt). Chemistry Dept., Faculty of Science

2000-10-01

An heterocyclic organic compound containing amine group namely: 3-mercaptomethyl-4amino-5-hydroxy-1, 2, 4-triazole compound 1{sub a} was tested as a new inhibitor for copper corrosion in 5.0 M HNO{sub 3} solution. It proved to have a high value of inhibition efficiency (> 99.9%) at an inhibitor concentration of {>=} 2.5 x 10{sup -}3 M. A parallelism is established between the results obtained from weight loss, thermometric and galvanostatic polarization techniques. The high protective effect of compound I{sub a} is related to the decomposition of HNO{sub 2} formed through the autocatalytic cycle. The decomposition of HNO{sub 2} could be attributed to its reaction with the adsorbed inhibitor amine group. Furthermore, the results indicated that compound I{sub a} provides long-term protection and behaves as a mixed inhibitor type with a predominant cathodic effectiveness. [Italian] E' stato valutato, quale nuovo inibitore della corrosione del rame in soluzione 5.0 M di HNO{sub 3}, un composto organico eterociclico contenente un amino gruppo, chiamato: 3-mercaptometil-4amino-5-idrossi-1, 2, 4-triazolo composto I{sub a}. Questi, ad una concentrazione {>=} 2.5 x 10{sup -}3 M, ha dimostrato di possedere un elevato valore di efficienza di inibizione (> 99.9%). E' stato stabilito un parallelismo tra i risultati ottenuti dalla perdita di peso, da misure termometriche e di polarizzazione galvanostatica. L'elevato effetto protettivo del composto I{sub a} e' correlato alla decomposizione dell'HNO{sub 2} formatosi attraverso il ciclo autocatalitico. La decomposizione di HNO{sub 2} puo' essere attribuita alla sua reazione con il gruppo inibitore aminico adsorbito. Inoltre, i risultati indicano che il composto I{sub a} fornisce una protezione a lungo termine e si comporta come un inibitore di tipo misto con una predominante efficienza catodica.

Novel synthesis and antitumor evaluation of polyfunctionally substituted heterocyclic compounds derived from 2-cyano-N-(3-cyano-4,5,6,7-tetrahydrobenzo[b]thiophen-2-yl)-acetamide.

Science.gov (United States)

Shams, Hoda Z; Mohareb, Rafat M; Helal, Maher H; Mahmoud, Amira E

2010-12-27

The reaction of 2-amino-3-cyano-4,5,6,7-tetrahydrobenzo[b]thiophene with ethyl cyanoacetate gave 2-cyano-N-(3-cyano-4,5,6,7-tetrahydrobenzo[b]thiophen-2-yl)-acetamide. The latter was used to synthesize different heterocyclic derivatives comprising thiophene, thiazole, pyrazole, pyridine, pyrimidine, and coumarin rings. The mechanistic and synthetic pathways depended on regioselective attack and/or cyclization by the cyanoacetamido moiety in the key precursor on various chemical reagents. The competition of the reaction pathways including dipolar cyclization, dinucleophilic-bielectrophilic attack, β-attack, Gewald-type attack, and condensation reactions led to the diversity of the synthesized products. The antitumor activities of the synthesized products were studied and evaluated. Most of the compounds revealed high inhibitory effects when screened in vitro for their antiproliferative activity. Three human cancer cell lines, namely, breast adenocarcinoma (MCF-7), non-small cell lung cancer (NCI-H460) and CNS cancer (SF-268) were used in the screening tests. The simplicity of the synthetic procedures which mainly involved one-pot reactions under mild reaction conditions, the convenience of yield production and the diversity of the reactive sites in the produced systems play a valuable role for further heterocyclic transformations and further biological investigations.

Effect of AZO on GO-NO-GO radiation indicator

International Nuclear Information System (INIS)

Hasan Sham; Taiman Kadni; Noriah Mod Ali

2002-01-01

The purpose of the study is to evaluate the effect of Azo group dyes as an radiation indicator. Dimethyl Yellow, Alizarin Red, Congo Red, Methyl Violet and Bromophenol Blue dyes were used to compare the capability of each dye to change colour in response to radiation. Sensitivity of single and incorporated dyes were identified by exposing them to 5-50 kGy gamma radiation. The result shows that the Azo group is more sensitive to radiation compare to other groups. (Author)

A novel ITO/AZO/SiO2/p-Si frame SIS heterojunction fabricated by magnetron sputtering

International Nuclear Information System (INIS)

He, Bo; Wang, HongZhi; Li, YaoGang; Ma, ZhongQuan; Xu, Jing; Zhang, QingHong; Wang, ChunRui; Xing, HuaiZhong; Zhao, Lei; Rui, YiChuan

2013-01-01

Highlights: •Because the ITO/AZO double films lead to a great decrease of the lateral resistance. •The photon current can easily flow through top film entering the Cu front contact. •High photocurrent is obtained under a reverse bias. -- Abstract: The novel ITO/AZO/SiO 2 /p-Si SIS heterojunction has been fabricated by low temperature thermal oxidation an ultrathin silicon dioxide and RF sputtering deposition ITO/AZO double films on p-Si (1 0 0) polished substrate. The microstructural, optical and electrical properties of the ITO/AZO antireflection films were characterized by XRD, SEM, UV–VIS spectrophotometer, four point probe and Hall effect measurement, respectively. The results show that ITO/AZO films are of good quality. And XPS was carried out on the ultrathin SiO 2 film. The heterojunction shows strong rectifying behavior under a dark condition, which reveals that formation of a diode between AZO and p-Si. The ideality factor and the saturation current of this diode is 2.7 and 8.68 × 10 −5 A, respectively. High photocurrent is obtained under a reverse bias when the crystalline quality of ITO/AZO double films is good enough to transmit the light into p-Si. We can see that under reverse bias conditions the photocurrent of ITO/AZO/SiO 2 /p-Si SIS heterojunction is much higher than the photocurrent of AZO/SiO 2 /p-Si SIS heterojunction. Because the high quality crystallite and the good conductivity of ITO film which prepared by magnetron-sputtering on AZO film lead to a great decrease of the lateral resistance. The photon induced current can easily flow through ITO layer entering the Cu front contact. Thus, high photocurrent is obtained under a reverse bias

Reactions of homolytic addition of polyhalogenoalkanes to unsafurated tin-organic compounds and their application in organic synthesis

International Nuclear Information System (INIS)

Rakhlin, V.I.; Mirskov, R.G.; Voronkov, M.G.

1996-01-01

Reactions of homolytic addition of polyhalogenoalkanes; including iodine compounds, to tin trialkylalkenyl derivatives are considered. They may be used as convenient method for synthesis of various polyhalogenoalkylsubstituted alicycles and heterocycles: cyclopropane, 1.3-dioxocycloalkanes, thiacycloalkanes, various nitrogen-containing heterocycles. 27 refs

Spectroscopic, thermal, catalytic and biological studies of Cu(II) azo dye complexes

Science.gov (United States)

El-Sonbati, A. Z.; Diab, M. A.; El-Bindary, A. A.; Shoair, A. F.; Hussein, M. A.; El-Boz, R. A.

2017-08-01

New complexes of copper(II) with azo compounds of 5-amino-2-(aryl diazenyl)phenol (HLn) are prepared and investigated by elemental analyses, molar conductance, IR, 1H NMR, UV-Visible, mass, ESR spectra, magnetic susceptibility measurements and thermal analyses. The complexes have a square planar structure and general formula [Cu(Ln)(OAc)]H2O. Study the catalytic activities of Cu(II) complexes toward oxidation of benzyl alcohol derivatives to carbonyl compounds were tested using H2O2 as the oxidant. The intrinsic binding constants (Kb) of the ligands (HLn) and Cu(II) complexes (1-4) with CT-DNA are determined. The formed compounds have been tested for biological activity of antioxidants, antibacterial against Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) bacteria and yeast Candida albicans. Antibiotic (Ampicillin) and antifungal against (Colitrimazole) and cytotoxic compounds HL1, HL2, HL3 and complex (1) showed moderate to good activity against S. aureus, E. coli and Candida albicans, and also to be moderate on antioxidants and toxic substances. Molecular docking is used to predict the binding between the ligands with the receptor of breast cancer (2a91).

Differential specificity in the glomerular response profiles for alicyclic, bicyclic and heterocyclic odorants

Science.gov (United States)

Johnson, Brett A.; Xu, Zhe; Pancoast, Paige; Kwok, Jennifer; Ong, Joan; Leon, Michael

2008-01-01

As part of our ongoing effort to relate stimulus to response in the olfactory system, we tested the hypothesis that the unique chemical structures and odors of various cyclic odorants would be associated with unique spatial response patterns in the glomerular layer of the rat olfactory bulb. To this end, rats were exposed to sets of odorants including monocyclic hydrocarbons, bicyclic compounds, and various heterocyclic structures containing oxygen or nitrogen in the ring. Relative activity across the entire layer was assessed by mapping uptake of 2-deoxyglucose into anatomically standardized data matrices. Whereas monocyclic hydrocarbons evoked patterns similar to those evoked by open-chained hydrocarbon odorants, a set of bicyclic compounds with structures and odors similar to camphor evoked uptake in paired ventral domains not previously associated with any other odorant chemical structures. Despite their unique odors as judged by humans, heterocyclic odorants either evoked uptake in previously characterized areas corresponding to their functional groups or stimulated weak or patchy patterns involving isolated glomeruli. While the patchiness of the patterns may be partly related to the rigidity of the compounds, which would be expected to restrict their interactions to only a few receptors, the weakness of the patterns suggests the possibility of species-specific odorant representations. We conclude that whereas some of the novel cyclic structures indeed were represented by unique patterns in the rat bulb, other unique structures were poorly represented, even when they evoked intense and unique odors in humans. PMID:16958095

CYP-450 isoenzymes catalyze the generation of hazardous aromatic amines after reaction with the azo dye Sudan III.

Science.gov (United States)

Zanoni, Thalita Boldrin; Lizier, Thiago M; Assis, Marilda das Dores; Zanoni, Maria Valnice B; de Oliveira, Danielle Palma

2013-07-01

This work describes the mutagenic response of Sudan III, an adulterant food dye, using Salmonella typhimurium assay and the generation of hazardous aromatic amines after different oxidation methods of this azo dye. For that, we used metabolic activation by S9, catalytic oxidation by ironporphyrin and electrochemistry oxidation in order to simulate endogenous oxidation conditions. The oxidation reactions promoted discoloration from 65% to 95% of Sudan III at 1 × 10(-4)molL(-1) and generation of 7.6 × 10(-7)molL(-1) to 0.31 × 10(-4)molL(-1) of aniline, o-anisidine, 2-methoxi-5-methylaniline, 4-aminobiphenyl, 4,4'-oxydianiline; 4,4'-diaminodiphenylmethane and 2,6-dimethylaniline. The results were confirmed by LC-MS-MS experiments. We also correlate the mutagenic effects of Sudan III using S. typhimurium with the strain TA1535 in the presence of exogenous metabolic activation (S9) with the metabolization products of this compound. Our findings clearly indicate that aromatic amines are formed due to oxidative reactions that can be promoted by hepatic cells, after the ingestion of Sudan III. Considering that, the use of azo compounds as food dyestuffs should be carefully controlled. Copyright © 2013 Elsevier Ltd. All rights reserved.

Vapor pressures and sublimation enthalpies of novel bicyclic heterocycle derivatives

International Nuclear Information System (INIS)

Blokhina, Svetlana V.; Ol’khovich, Marina V.; Sharapova, Angelica V.; Perlovich, German L.; Proshin, Alexey N.

2014-01-01

Highlights: • The vapor pressures of novel bicyclo-derivatives of amine were measured. • Thermodynamic functions of sublimation were calculated. • The influence of substituent structure and chemical nature on the vapor pressure was studied. -- Abstract: The vapor pressures of five novel bicyclic heterocycle derivatives were measured over the temperature 341.15 to 396.15 K using the transpiration method by means of an inert gas carrier. From these results the standard enthalpies and Gibbs free energies of sublimation at the temperature 298.15 K were calculated. The effects of alkyl- and chloro-substitutions on changes in the thermodynamic functions have been investigated. Quantitative structure–property relationship on the basis HYBOT physico-chemical descriptors for biologically active compounds have been developed to predict the sublimation enthalpies and Gibbs free energies of the compounds studied

Design, synthesis and evaluation of aromatic heterocyclic derivatives as potent antifungal agents.

Science.gov (United States)

Zhao, Shizhen; Zhang, Xiangqian; Wei, Peng; Su, Xin; Zhao, Liyu; Wu, Mengya; Hao, Chenzhou; Liu, Chunchi; Zhao, Dongmei; Cheng, Maosheng

2017-09-08

To further enhance the anti-Aspergillus efficacy of our previously discovered antifungal lead compounds (1), a series of aromatic heterocyclic derivatives were designed, synthesized and evaluated for in vitro antifungal activity. Many of the target compounds showed good inhibitory activity against Candida albicans and Cryptococcus neoformans. In particular, the isoxazole nuclei were more suited for improving the activity against Aspergillus spp. Among these compounds, 2-F substituted analogues 23g and 23h displayed the most remarkable in vitro activity against Candida spp., C. neoformans, A. fumigatus and fluconazole-resistant C.alb. strains, which is superior or comparable to the activity of the reference drugs fluconazole and voriconazole. Notably, the compounds 23g and 23h exhibited low inhibition profiles for various isoforms of human cytochrome P450 and excellent blood plasma stability. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Structural Correlation of Some Heterocyclic Chalcone Analogues and Evaluation of Their Antioxidant Potential

Directory of Open Access Journals (Sweden)

Hoong-Kun Fun

2013-09-01

Full Text Available A series of six novel heterocyclic chalcone analogues 4(a–f has been synthesized by condensing 2-acetyl-5-chlorothiophene with benzaldehyde derivatives in methanol at room temperature using a catalytic amount of sodium hydroxide. The newly synthesized compounds are characterized by IR, mass spectra, elemental analysis and melting point. Subsequently; the structures of these compounds were determined using single crystal X-ray diffraction. All the synthesized compounds were screened for their antioxidant potential by employing various in vitro models such as DPPH free radical scavenging assay, ABTS radical scavenging assay, ferric reducing antioxidant power and cupric ion reducing antioxidant capacity. Results reflect the structural impact on the antioxidant ability of the compounds. The IC50 values illustrate the mild to good antioxidant activities of the reported compounds. Among them, 4f with a p-methoxy substituent was found to be more potent as antioxidant agent.

Synthesis of Heterocycles through a Ruthenium‐Catalyzed Tandem Ring‐Closing Metathesis/Isomerization/N‐Acyliminium Cyclization Sequence

DEFF Research Database (Denmark)

Ascic, Erhad; Jensen, Jakob Feldthusen; Nielsen, Thomas Eiland

2011-01-01

Tandem bicycle: In the title reaction double bonds created during ring-closing metathesis isomerize to generate reactive iminium intermediates that undergo intramolecular cyclization reactions with tethered heteroatom and carbon nucleophiles. In this way, a series of biologically interesting hete...... heterocyclic compounds can be made, including a known precursor for the total synthesis of the antiparasitic natural product harmicine....

The effect of dioctyl sodium sulphosuccinate on tartrazine azo reduction by intestinal bacteria.

Science.gov (United States)

Allan, R J; Roxon, J J

1977-03-01

1. Washed whole-cell suspensions of Proteus vulgaris and micro-organisms from rat faeces, reductively cleave the azo bond of the food dye tartrazine under anaerobic conditions. 2. Dioctyl sodium sulphosuccinate, a common faecal softening laxative, when added to incubations in vitro at concentrations greater than 0.005%, increases tartrazine azo reduction in P. vulgaris whole-cell suspensions. 3. By contrast, concentrations of dioctyl sodium sulphosuccinate greater than 0.005% when added to incubations in vitro of rat faecal preparations, resulted in an inhibition of tartrazine azo reduction.

[The decolorization and biodegrading metabolism of azo dyes by Pseudomonas S-42].

Science.gov (United States)

Liu, Z P; Yang, H F

1989-12-01

Pseudomonas S-42 was capable of decolorizing azo dyes such as Diamira Brilliant Orange RR(DBO-RR), Direct Brown M (DBM), Eriochrome Brown R(EBR) and so on. The cell suspension, cell-free extract and purified enzyme of Pseud. S-42 could decolorize azo dyes under similar conditions: the optimum pH and temperature laid 7.0 and 37 degrees C respectively. The efficiencies of decolorizing of DBO-RR, DBM, EBR by intact cells stood more than 90%. When the cell concentration was 15 mg(wet)/ml and the reaction time was 5 hours, the decolorizing activity for above three azo dyes by intact cells were 1.75, 2.4, 0.95 micrograms dye/mg cell, respectively. Cell-free extract and purified enzyme could well express the decolorizing activity only under the anaerobic condition and added NADH. Purified enzyme belongs to azoreductase, its molecular weight is about 34,000-2000 daltons, and its Vmax and Km for DBO-RR are 13 mumol.mg protein-1.min-1 and 54 mumol/L. The results of the detection of the biodegrading products of DBO-RR by spectrophotometric and NaNO2 reactional methods showed that the biodegradation of azo dyes was initiated by the reduction cleavage of azo bonds. It was hypothesized that biodegrading metabolism pathway of DBO-RR by Pseudomonas S-42.

Palladium-catalyzed allylation of tautomerizable heterocycles with alkynes.

Science.gov (United States)

Lu, Chuan-Jun; Chen, Dong-Kai; Chen, Hong; Wang, Hong; Jin, Hongwei; Huang, Xifu; Gao, Jianrong

2017-07-21

A method for the allylic amidation of tautomerizable heterocycles was developed by a palladium catalyzed allylation reaction with 100% atom economy. A series of structurally diverse N-allylic substituted heterocycles can be synthesized in good yields with high chemo-, regio-, and stereoselectivities under mild conditions.

Regioselective C-H imidation of five-membered heterocyclic compounds through a metal catalytic or organocatalytic approach.

Science.gov (United States)

Wang, Xin; Sun, Kai; Lv, Yunhe; Ma, Fengji; Li, Gang; Li, Donghui; Zhu, Zhonghong; Jiang, Yongqing; Zhao, Feng

2014-12-01

An efficient method for the synthesis of 2-amino and β-amino five-membered heterocyclic derivatives that are closely related to a variety of biologically active natural products is described. Regioselectivity was achieved through a metal catalytic or organocatalytic approach. Preliminary studies on the reaction mechanism suggest a radical imidation pathway; however, further studies are needed to verify the mechanism. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Domino approach to 2-aroyltrimethoxyindoles as novel heterocyclic combretastatin A4 analogues.

Science.gov (United States)

Arthuis, Martin; Pontikis, Renée; Chabot, Guy G; Quentin, Lionel; Scherman, Daniel; Florent, Jean-Claude

2011-01-01

Two series of 2-aroyltrimethoxyindoles were designed to investigate the effects of the replacement of the trimethoxyphenyl ring of phenstatin with a trimethoxyindole moiety. These compounds were efficiently prepared through a domino palladium-catalyzed sequence from 2-gem-dibromovinylanilines substituted by three methoxy groups and arylboronic acids under carbon monoxide atmosphere. These novel heterocyclic combretastatin A4 analogues were evaluated for their cell growth inhibitory properties and their ability to inhibit the tubulin polymerization. Copyright © 2010 Elsevier Masson SAS. All rights reserved.

Physicochemical study of niobium(5) complexes with rhodanide and heterocyclic bases

International Nuclear Information System (INIS)

Lobanov, F.I.; Zatonskaya, V.M.; Gibalo, I.M.

1980-01-01

Mixed complexes of niobium rhodanide with organic heterocyclic bases-1,10-phenanthroline; 2,3-dimethyl-1,10-phenanthroline; 4,7-diphenyl-1,10 phenanthroline-bathophenanthroline; S-collidine are singled out. The composition of the compounds is established. The character of the bonds Nb-O, Nb-NCS, Nb-basis is studied using the method of IR spectroscopy. Derivatogravimetric analysis of the complexes singled out has shown the complex character of their decomposition. The measurement of electric conductivity of the mixed complexes in dimethylformamide solutions has shown that they are binary electrolytes

Alkyne-Azide Cycloaddition Catalyzed by Silver Chloride and “Abnormal” Silver N-Heterocyclic Carbene Complex

Directory of Open Access Journals (Sweden)

Aldo I. Ortega-Arizmendi

2013-01-01

Full Text Available A library of 1,2,3-triazoles was synthesized from diverse alkynes and azides using catalytic amounts of silver chloride instead of copper compounds. In addition, a novel “abnormal” silver N-heterocyclic carbene complex was tested as catalyst in this process. The results suggest that the reaction requires only 0.5% of silver complex, affording 1,2,3-triazoles in good yields.

Ohmic contacts on n-type β-Ga2O3 using AZO/Ti/Au

Directory of Open Access Journals (Sweden)

Patrick H. Carey IV

2017-09-01

Full Text Available AZO interlayers between n-Ga2O3 and Ti/Au metallization significantly enhance Ohmic contact formation after annealing at ≥ 300°C. Without the presence of the AZO, similar anneals produce only rectifying current-voltage characteristics. Transmission Line Measurements of the Au/Ti/AZO/Ga2O3 stacks showed the specific contact resistance and transfer resistance decreased sharply from as-deposited values with annealing. The minimum contact resistance and specific contact resistance of 0.42 Ω-mm and 2.82 × 10-5 Ω-cm2 were achieved after a relatively low temperature 400°C annealing. The conduction band offset between AZO and Ga2O3 is 0.79 eV and provides a favorable pathway for improved electron transport across this interface.

Ohmic contacts on n-type β-Ga2O3 using AZO/Ti/Au

Science.gov (United States)

Carey, Patrick H.; Yang, Jiancheng; Ren, F.; Hays, David C.; Pearton, S. J.; Jang, Soohwan; Kuramata, Akito; Kravchenko, Ivan I.

2017-09-01

AZO interlayers between n-Ga2O3 and Ti/Au metallization significantly enhance Ohmic contact formation after annealing at ≥ 30 0°C. Without the presence of the AZO, similar anneals produce only rectifying current-voltage characteristics. Transmission Line Measurements of the Au/Ti/AZO/Ga2O3 stacks showed the specific contact resistance and transfer resistance decreased sharply from as-deposited values with annealing. The minimum contact resistance and specific contact resistance of 0.42 Ω-mm and 2.82 × 10-5 Ω-cm2 were achieved after a relatively low temperature 40 0°C annealing. The conduction band offset between AZO and Ga2O3 is 0.79 eV and provides a favorable pathway for improved electron transport across this interface.

Reduction of azo dyes by flavin reductase from Citrobacter freundii A1

Directory of Open Access Journals (Sweden)

Mohd Firdaus Abdul-Wahab

2012-12-01

Full Text Available Citrobacter freundii A1 isolated from a sewage treatment facility was demonstrated to be able to effectively decolorize azo dyes as pure and mixed culture. This study reports on the investigation on the enzymatic systems involved. An assay performed suggested the possible involvement of flavin reductase (Fre as an azo reductase. A heterologouslyexpressed recombinant Fre from C. freundii A1 was used to investigate its involvement in the azo reduction process. Three model dyes were used, namely Acid Red 27 (AR27, Direct Blue 15 (DB15 and Reactive Black 5 (RB5. AR27 was found to be reduced the fastest by Fre, followed by RB5, and lastly DB15. Redox mediators nicotinamide adenine dinucleotide (NADH and riboflavin enhance the reduction, suggesting the redox activity of the enzyme. The rate and extent of reduction of the model dyes correlate well with the reduction potentials (Ep. The data presented here strongly suggest that Fre is one of the enzymes responsible for azo reduction in C. freundii A1, acting via an oxidation-reduction reaction.

Metabolism of azo dyes by human skin microbiota.

Science.gov (United States)

Stingley, Robin L; Zou, Wen; Heinze, Thomas M; Chen, Huizhong; Cerniglia, Carl E

2010-01-01

Reduction of Methyl Red (MR) and Orange II (Or II) by 26 human skin bacterial species was monitored by a rapid spectrophotometric assay. The analysis indicated that skin bacteria, representing the genera Staphylococcus, Corynebacterium, Micrococcus, Dermacoccus and Kocuria, were able to reduce MR by 74-100 % in 24 h, with only three species unable to reduce completely the dye in that time. Among the species tested, only Corynebacterium xerosis was unable to reduce Or II to any degree by 24 h, and only Staphylococcus delphini, Staphylococcus sciuri subsp. sciuri and Pseudomonas aeruginosa were able to reduce completely this dye within 24 h. MR reduction started with early-exponential growth in Staphylococcus aureus and Staphylococcus epidermidis, and around late-exponential/early-stationary growth in P. aeruginosa. Reduction of Or II, Ponceau S and Ponceau BS started during late-exponential/early-stationary growth for all three species. Using liquid chromatography/electrospray ionization mass spectrometry analyses, MR metabolites produced by Staph. aureus, Staph. epidermidis and P. aeruginosa were identified as N,N-dimethyl-p-phenylenediamine and 2-aminobenzoic acid. Searches of available genomic and proteomic data revealed that at least four of the staphylococci in this study, Staphylococcus haemolyticus, Staph. epidermidis, Staphylococcus cohnii and Staphylococcus saprophyticus, have hypothetical genes with 77, 76, 75 and 74 % sequence identity to azo1 encoding an azoreductase from Staph. aureus and hypothetical proteins with 82, 80, 72 and 74 % identity to Azo1, respectively. In addition, Staphylococcus capitis has a protein with 79 % identity to Azo1. Western analysis detected proteins similar to Azo1 in all the staphylococci tested, except Staph. delphini, Staph. sciuri subsp. sciuri and Staphylococcus auricularis. The data presented in this report will be useful in the risk assessment process for evaluation of public exposure to products containing these dyes.

Low resistance and transparent Ag/AZO ohmic contact to p-GaN

International Nuclear Information System (INIS)

Han, T.; Wang, T.; Gan, X. W.; Wu, H.; Shi, Y.; Liu, C.

2014-01-01

Silver (Ag)/ aluminum-doped zinc oxide (AZO) films were deposited on p-GaN by using electron beam evaporation. After the annealing process, current -voltage (I-V) measurements were carried out to determine the characteristic of the contacts. The Ag/AZO films annealed at 600 .deg. C were found to present an ohmic contact behavior. The specific contact resistance was calculated to be 9.76 x 10 -4 Ωcm 2 and the transmittance was over 80% for visibly light. The atomic force microscope was used to measure the aggregation of Ag grains which may have been the main factor in the formation of the Ag/AZO ohmic contact to p-GaN.

Regiospecificity in the heterocyclization of b-oxonitriles to 5-substituted 4-oxothiazolidine derivatives

Directory of Open Access Journals (Sweden)

PETER STEEL

2003-05-01

Full Text Available A study on the regiospecificity of the base-catalyzed reaction of activated b-oxonitriles 1 with diethyl mercaptosuccinate affording the title compounds 3 is reported. Other competitive heterocyclic products, that is 4-oxo-1,3-thiazinanes 4, derivatives of tetrahydrothiophene 5 and/or thiacyclohexane 6 which on the grounds of mechanistic considerations could be formed, were not observed. Spectroscopic and experimental evidence, together with theoretical considerations, provides a reasonable explanation for the observed regiospecificity.

Enhanced performance of a-IGZO thin-film transistors by forming AZO/IGZO heterojunction source/drain contacts

International Nuclear Information System (INIS)

Zou, Xiao; Fang, Guojia; Wan, Jiawei; Liu, Nishuang; Long, Hao; Wang, Haolin; Zhao, Xingzhong

2011-01-01

A low-cost Al-doped ZnO (AZO) thin film was deposited by radio-frequency magnetron sputtering with different Ar/O 2 flow ratios. The optical and electrical properties of an AZO film were investigated. A highly conductive AZO film was inserted between the amorphous InGaZnO (a-IGZO) channel and the metal Al electrode to form a heterojunction source/drain contact, and bottom-gate amorphous a-IGZO thin-film transistors (TFTs) with a high κ HfON gate dielectric were fabricated. The AZO film reduced the source/drain contact resistivity down to 79 Ω cm. Enhanced device performance of a-IGZO TFT with Al/AZO bi-layer S/D electrodes (W/L = 500/40 µm) was achieved with a saturation mobility of 13.7 cm 2 V −1 s −1 , a threshold voltage of 0.6 V, an on-off current ratio of 4.7 × 10 6 , and a subthreshold gate voltage swing of 0.25 V dec −1 . It demonstrated the potential application of the AZO film as a promising S/D contact material for the fabrication of the high performance TFTs

Biodegradation of NSO-compounds under different redox-conditions

DEFF Research Database (Denmark)

Dyreborg, S.; Arvin, E.; Broholm, K.

1997-01-01

Laboratory experiments were carried out to investigate the potential of groundwater microorganisms to degrade selected heterocyclic aromatic compounds containing nitrogen, sulphur, or oxygen (NSO-compounds) under four redox-conditions over a period of 846 days. Eight compounds (pyrrole, 1...... anaerobic conditions, even though the microorganisms present in the anaerobic microcosms were active throughout the incubation period. A high variability in the lag period among the NSO-compounds was observed under aerobic conditions. While quinoline, indole, and carbazole were degraded with a lag period...

Reversible photocontrol of molecular assemblies of metal complex containing azo-amphiphiles

International Nuclear Information System (INIS)

Einaga, Yasuaki; Mikami, Rie; Akitsu, Takashiro; Li, Guangming

2005-01-01

Photo-controllable molecular systems, [M(en) 2 ][Pt(en) 2 Cl 2 ](1) 4 (M 2+ =Pt 2+ , Pd 2+ and en=ethylenediamine), have been designed by the self-assembly of chloride-bridged platinum/palladium complexes and photochromic amphiphiles of the azobenzene derivative, 4-[4-(N-methyl-N-n-dodecylamino)phenylazo]benzene sulfonic acid (designated as compound 1). Reversible structural changes caused by cis-trans photoisomerization of azo groups in compound 1 were observed by alternating illumination of UV and visible light. Visible illumination resulted in the formation of the plate-like structures, whereas UV illumination resulted in fragmentation of the assembling structures. Reversible changes were observed in the electronic states of the chloride-bridged platinum/palladium complexes; the plate-like structures exhibited charge transfer absorption of chloride-bridged platinum complexes and delocalized Pt(II)/Pt(IV) states, while the fragments of the separated complexes exhibited no charge transfer bands. As a consequence, we have discovered that the reversible structural changes in this system could be controlled by photoillumination

On the radioprotective properties of heterocyclic nitrogenous compounds; Etude des proprietes radioprotectrices de composes heterocycliques azotes

Energy Technology Data Exchange (ETDEWEB)

Rinaldi, R; Bernard, Y [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

1964-07-01

Continuing their study of the possible radioprotective properties of heterocyclic nitrogenous compounds, the authors study certain derivatives of imidazole and other compounds of similar structure. The results obtained showed: 1 - that the derivatives resulting from the presence in the imidazole ring of the mercapto, methyl, carbonyl, or benzyl groups are inactive: these substitutions appear to destroy the significant radioprotective activity of the imidazole, 2 - that benzimidazole, on the contrary, seems to possess highly interesting properties. The percentage of survivals obtained with mice treated with benzimidazole and exposed to lethal irradiation has encouraged the authors to undertake careful study of this substance, with a view to define optimum activity conditions, and to determine the mechanism responsible for its radioprotective action. Further on and so as to of clarify certain points that might give useful data concerning the mechanisms of action of radioprotective chemicals, in respect of each of the products the authors have studied: a - the action of these bodies on the internal temperature of mice, b - their radioprotective activity in vitro, in a solution of irradiated hemin. (authors) [French] Les proprietes radioprotectrices de l'imidazole ayant ete mises en evidence dans un precedent travail, les auteurs poursuivent leur experimentation sur certains derives de ce noyau ainsi que des composes de structure voisine. Leurs resultats montrent: 1 - que les composes obtenus par substitution d'un groupement mercapto, methyle, carbonyle ou benzyle, a un hydrogene du noyau imidazole sont inactifs, 2 - que le benzimidazole presente par contre des proprietes interessantes. Pour ce dernier compose le pourcentage de survie pouvant atteindre 90 pour cent les auteurs ont determine les conditions optimales de son activite radioprotectrice; de plus, dans le but d'obtenir des renseignements susceptibles de preciser le mecanisme d'action de la radioprotection

Diphenyl (4′-(Aryldiazenylbiphenyl-4-ylamino(pyridin-3-ylmethylphosphonates as Azo Disperse Dyes for Dyeing Polyester Fabrics

Directory of Open Access Journals (Sweden)

Mohamed F. Abdel-Megeed

2013-01-01

Full Text Available Diphenyl (4′-aminobiphenyl-4-ylamino(pyridin-3-ylmethylphosphonate (1 was synthesized in 88% yield from reaction of pyridine-3-carboxaldehyde with benzidine and triphenylphosphite in the presence of titanium tetrachloride as a catalyst. Diazotization of 1 gave the corresponding diazonium salt 2 which was coupled with several hydroxyl or amino compounds to give the corresponding azo dyes 3–8 in 82–88% yields after crystallization. The dyes produced were applied to polyesters as disperse dyes and their fastness properties were elevated.

New Homologues Series of Heterocyclic Schiff Base Ester: Synthesis and Characterization

Directory of Open Access Journals (Sweden)

Yee-Ting Chong

2016-01-01

Full Text Available A homologous series of liquid crystal bearing with heterocyclic thiophene Schiff base ester with alkanoyloxy chain (CH3(CH2nCOO–, where n=4, 6, 8, 10, 12, 14, 16 was successfully synthesized through the modification of some reported methods. The structural information of these compounds was isolated and characterized through some spectroscopic techniques, such as FTIR, 1H, and 13C NMR and elemental analysis. Textural observation was carried out using a polarizing optical microscope (POM over heating and cooling cycles. It was found that all synthesized compounds (3a–g exhibited an enantiotropic nematic phase upon the heating and cooling cycle with high thermal stability. Moreover, a characteristic bar transition texture was observed for compounds 3f and 3g which have shown transition of nematic-to-smectic C phase. This has been further confirmed by obtaining relative phase transition temperature using the differential scanning calorimetry (DSC.

Strong guided mode resonant local field enhanced visible harmonic generation in an azo-polymer resonant waveguide grating.

Science.gov (United States)

Lin, Jian Hung; Tseng, Chun-Yen; Lee, Ching-Ting; Young, Jeff F; Kan, Hung-Chih; Hsu, Chia Chen

2014-02-10

Guided mode resonance (GMR) enhanced second- and third-harmonic generation (SHG and THG) is demonstrated in an azo-polymer resonant waveguide grating (RWG), comprised of a poled azo-polymer layer on top of a textured SU8 substrate with a thin intervening layer of TiO2. Strong SHG and THG outputs are observed by matching either in-coming fundamental- or out-going harmonic-wavelength to the GMR wavelengths of the azo-polymer RWG. Without the azo-polymer coating, pure TiO2 RWGs, do not generate any detectable SHG using a fundamental beam peak intensity of 2 MW/cm(2). Without the textured TiO2 layer, a planar poled azo-polymer layer results in 3650 times less SHG than the full nonlinear RWG structure under identical excitation conditions. Rigorous coupled-wave analysis calculations confirm that this enhancement of the nonlinear conversion is due to strong local electric fields that are generated at the interfaces of the TiO2 and azo-polymer layers when the RWG is excited at resonant wavelengths associated with both SHG and THG conversion processes.

AZO/Ag/AZO anode for resonant cavity red, blue, and yellow organic light emitting diodes

Energy Technology Data Exchange (ETDEWEB)

Gentle, A. R., E-mail: angus.gentle@uts.edu.au; Smith, G. B. [School of Mathematical and Physical Sciences and Institute of Nanoscale Technology, University of Technology Sydney, P.O. Box 123, Broadway, New South Wales 2007 (Australia); Yambem, S. D.; Burn, P. L.; Meredith, P. [Centre for Organic Photonics and Electronics, School of Chemistry and Molecular Biosciences and School of Mathematics and Physics, The University of Queensland, St Lucia, Queensland 4072 (Australia)

2016-06-28

Indium tin oxide (ITO) is the transparent electrode of choice for organic light-emitting diodes (OLEDs). Replacing ITO for cost and performance reasons is a major drive across optoelectronics. In this work, we show that changing the transparent electrode on red, blue, and yellow OLEDs from ITO to a multilayer buffered aluminium zinc oxide/silver/aluminium zinc oxide (AZO/Ag/AZO) substantially enhances total output intensity, with better control of colour, its constancy, and intensity over the full exit hemisphere. The thin Ag containing layer induces a resonant cavity optical response of the complete device. This is tuned to the emission spectra of the emissive material while minimizing internally trapped light. A complete set of spectral intensity data is presented across the full exit hemisphere for each electrode type and each OLED colour. Emission zone modelling of output spectra at a wide range of exit angles to the normal was in excellent agreement with the experimental data and hence could, in principle, be used to check and adjust production settings. These multilayer transparent electrodes show significant potential for both eliminating indium from OLEDs and spectrally shaping the emission.

Polyazidopyrimidines: High Energy Compounds and Precursors to Carbon Nanotubes (Postprint)

National Research Council Canada - National Science Library

Ye, Chengfeng; Gao, Haixiang; Boatz, Jerry A; Drake, Gregory W; Twamley, Brendan; Shreeve, Jean'ne M

2006-01-01

...). The compound 4,4',6,6'-tetra(azido)azo-1,3,5-triazine (2), has a heat of formation of 2171 (6164 kJ kg -1) (Fig. 1). Recently it was demonstrated that 1 and 2 were good precursors to nano carbon nitride materials...

METHODS OF SYNTHESIS EIGHT-TELLURIUM-CONTAINING HETEROCYCLES WITH MORE HETEROATOMS

Directory of Open Access Journals (Sweden)

G. M. Abakarov

2013-01-01

Full Text Available In this article systematized and summarized data on the synthesis of neweight-embered tellurium-containing heterocycles and new preparative methods described above produce heterocyclic tellurium.

Structural mechanisms of photoeffect in polyimide structures containing heterocyclic fragments

International Nuclear Information System (INIS)

Aleksandrova, E. L.

2006-01-01

Trends in the variation in the quantum yields of charge-carrier photogeneration in polyimide structures containing heterocyclic fragments are studied. It is shown that the efficiency of sensitization of polyimides depends on the donor and acceptor properties of the fragments of monomeric units of the polyimide. It is established that the range of spectral sensitivity for heterocyclic fragments representing intramolecular complexes with charge transport is wider than that for heterocycles that do not represent such complexes

Cyclodepsipeptides and other O-containing heterocyclic metabolites from Beauveria felina EN-135, a marine-derived entomopathogenic fungus.

Science.gov (United States)

Du, Feng-Yu; Li, Xiao-Ming; Zhang, Peng; Li, Chun-Shun; Wang, Bin-Gui

2014-05-13

Bioassay-guided fractionation of a culture extract of Beauveria felina EN-135, an entomopathogenic fungus isolated from a marine bryozoan, led to the isolation of a new cyclodepsipeptide, iso-isariin D (1); two new O-containing heterocyclic compounds that we have named felinones A and B (2 and 3); and four known cyclodepsipeptides (4-7). The structures were elucidated via spectroscopic analysis, and the absolute configurations of 1 and 2 were determined using single-crystal X-ray diffraction and CD, respectively. All isolated compounds were evaluated for antimicrobial activity and brine-shrimp (Artemia salina) lethality.

Experimental Study on Fabrication of AZO Transparent Electrode for Organic Solar Cell Using Selective Low-Temperature Atomic Layer Deposition

International Nuclear Information System (INIS)

Kim, Kicheol; Song, Gensoo; Kim, Hyungtae; Yoo, Kyunghoon; Kang, Jeongjin; Hwang, Junyoung; Lee, Sangho; Kang, Kyungtae; Kang, Heuiseok; Cho, Youngjune

2013-01-01

AZO (aluminum-doped zinc oxide) is one of the best candidate materials to replace Into (indium tin oxide) for TKOs (transparent conductive oxides) used in flat panel displays, organic light-emitting diodes (OLDS), and organic solar cells (OCSS). In the present study, to apply an AZO thin film to the transparent electrode of an organic solar cell, a low temperature selective atomic layer deposition (ALD) process was adopted to deposit an AZO thin film on a flexible polyethylene-naphthanate (Pen) substrate. The reactive gases for the ALD process were di-ethyl-zinc (De) and tri-methylaluminum (Tma) as precursors and H 2 O as an oxidant. The structural, electrical, and optical characteristics of the AZO thin film were evaluated. From the measured results of the electrical and optical characteristics of the AZO thin films deposited on the Pen substrates by Ald, it was shown that the Azo thin film appeared to be comparable to a commercially used Into thin film, which confirmed the feasibility of AZO as a TCO for flexible organic solar cells in the near future

Polyazido Pyrimidines: High Energy Compounds and Precursors to Carbon Nanotubes (PREPRINT)

National Research Council Canada - National Science Library

Ye, Chengfeng; Gao, Haoxiang; Twamley, Brendan; Shreeve, Jean'ne M; Drake, Gregory W; Boatz, Jerry A

2006-01-01

...). The compound 4,4',6,6'-tetra(azido)azo-1,3,5-triazine (2), has a heat of formation of 2171 (6164 kJ kg -1). Recently it was demonstrated that 1 and 4 were good precursors to nano carbon nitride materials...

Photocatalytic fluoroalkylation reactions of organic compounds

OpenAIRE

Barata Vallejo, Sebastian; Bonesi, Sergio Mauricio; Postigo, Jose Alberto

2017-01-01

Photocatalytic methods for fluoroalkyl-radical generation provide more convenient alternatives to the classical perfluoroalkyl-radical (Rf) production through chemical initiators, such as azo or peroxide compounds or the employment of transition metals through a thermal electron transfer (ET) initiation process. The mild photocatalytic reaction conditions tolerate a variety of functional groups and, thus, are handy to the late-stage modification of bioactive molecules. Transition metal-photoc...

Synthesis of pyridine and isoquinoline labelled with 14C on the nitrogen heterocycle

International Nuclear Information System (INIS)

Robveille, Jacques

1985-01-01

This research thesis addresses the synthesis of derivatives of pyridine and isoquinoline labelled with carbon 14 ( 14 C) in the nitrogenated heterocycle as these compounds are of biological and pharmacological interest. The author aimed at developing rather general synthesis schemes which could be easily applied to the synthesis of radioactive compounds, and could produce, through a given synthesis way, the largest as possible family of differently substituted compounds. Different sources for labelled pyridine and isoquinoline have been used: dioxo-1,5 or their corresponding dioxins, substituted pentadienoic acids, derivatives of acrylic acid, and derivatives of cinnamic acid. Thus, three different synthesis processes have been developed to obtain 14 C labelled pyridine, and one of them is applied to the preparation of 14 C labelled isoquinoline. These synthesis processes can have a very general application, and allow different 14 C labelling positions to be envisaged. The possibility to obtain the same compounds but labelled with tritium can also be envisaged to obtain much higher specific activities [fr

Optimization of AZO films prepared on flexible substrates

Indian Academy of Sciences (India)

Administrator

grey relational analysis, the optimization of these deposition process parameters for AZO thin films with multiple characteristics ... bias voltage, annealing temperature and plasma treatment deposition time (Pei et ... water and dried in nitrogen.

SYNTHESIS AND STUDY OF HALOGENATED BENZYLAMIDES OF SOME ISOCYCLIC AND HETEROCYCLIC ACIDS AS POTENTIAL ANTICONVULSANTS.

Science.gov (United States)

Strupińska, Marzanna; Rostafińska-Suchar, Grażyna; Pirianowicz-Chaber, Elżbieta; Grabczuk, Mateusz; Józwenko, Magdalena; Kowalczyk, Hubert; Szuba, Joanna; Wójcicka, Monika; Chen, Tracy; Mazurek, Aleksander P

2015-01-01

A series of potential anticonvulsants have been synthesized. There are eight fluorobenzylamides and three chlorobenzylamides of isocyclic or heterocyclic acids. Two not halogenated benzylamides were also synthesized to compare the effect of halogenation. The aim of the research performed was to evaluate whether halogenation of the mother structure is able to improve its anticonvulsant activity. The compounds were tested in Anticonvulsant Screening Project (ASP) of Antiepileptic Drug Development Program (ADDP) of NIH. Compound 1 showed MES ED50 = 80.32 mg/kg, PI = 3.16. Compound 7 showed CKM ED50 = 56.72 mg/kg. Compound 8 showed MES ED50 = 34.23 mg/kg and scPTZ ED50 > 300 mg/kg, PI = 8.53.Compound 13 showed 6Hz ED50 = 78.96, PI = 3.37. The results indicate that fluorination does not improve activity, whereas chlorination in our experiment even reduces it.

Transparent conducting AZO and ITO films produced by pulsed laser ablation at 355 nm

DEFF Research Database (Denmark)

Thestrup, B.; Schou, Jørgen

1999-01-01

Thin films of aluminium-doped zinc oxide (AZO) and indium tin oxide (ITO) were deposited on glass substrates by laser ablation in an oxygen environment. The electrical and optical properties of films grown at various oxygen pressures were compared. With no substrate heating, highly transparent...... and conducting films were obtained with oxygen pressures between 15 and 23 mTorr for both materials. We obtained a specific resistivity of 1.8 x 10(-3) Omega cm for AZO and 1.1 x 10(-3) Omega cm for ITO. By heating the substrate to 160 degrees C or 200 degrees C, the resistivity was further reduced to 1.1 x 10......(-3) Omega cm for AZO and 3.9 x 10(-4) Omega cm for ITO. The average transmission of visible light (450-750 MI) was between 82% and 98% in most cases. The results suggest that AZO is a promising alternative to ITO....

Computational models for structure-hydrophobicity relationships of 4-carboxyl-2,6-dinitrophenyl azo hydroxynaphthalenes.

Science.gov (United States)

Idowu, Olakunle S; Adegoke, Olajire A; Idowu, Abiola; Olaniyi, Ajibola A

2007-01-01

Some phenyl azo hydroxynaphthalene dyes (e.g., sunset yellow) are certified as approved colorants for food, cosmetics, and drug formulations. The hydrophobicity of 4 newly synthesized azo dyes of the phenyl azo hydroxynaphthalene class was investigated, as a training set, with the goal of developing models for quantitative structure-property relationships (QSPR). Retention behavior of the molecules reversed-phase thin-layer chromatography (RPTLC) was investigated using liquid paraffin-coated silica gel as the stationary phase. Mobile phases consisted of aqueous mixtures of methanol, acetone, and dimethylformamide (DMF). Basic hydrophobicity parameter (Rmw), specific hydrophobic surface area (S), and isocratic chromatographic hydrophobicity index (phio) were computed from the chromatographic data. The hydrophobicity index (Rm) decreased linearly with increasing concentration of organic modifiers. Extrapolated Rmw values obtained by using DMF and acetone differ significantly from the value obtained by using methanol as organic modifier [P dyes and may also play useful roles in computer-assisted molecular discovery of nontoxic azo dyes.

Influence of various thickness metallic interlayers on opto-electric and mechanical properties of AZO thin films on PET substrates

Science.gov (United States)

Chang, R. C.; Li, T. C.; Lin, C. W.

2012-02-01

Various thickness metallic interlayers to improve the opto-electric and mechanical properties of aluminum-doped zinc oxide (AZO) thin films deposited on flexible polyethylene terephtalate (PET) substrates are studied. The effects of the interlayers on the resistance and transmittance of the AZO thin films are discussed. The result shows that the metallic interlayers effectively improve the electric resistance but reduce the optical transmittance of the AZO thin films. These phenomena become more obvious as the interlayer thickness increases. However, the AZO with an aluminum interlayer still behaves an acceptable transmittance. Moreover, mechanical tests indicate that the aluminum interlayer increases the hardness and modulus, and reduce the residual stress of the AZO thin films. In contrast, the silver and copper interlayers decrease the AZO's mechanical properties. Comparing to those without any interlayer, the results show that the best interlayer is the 6 nm thick aluminum film.

Studies on Dyeing Performance of Novel Acid Azo Dyes and Mordent Acid Azo Dyes Based on 2,4-Dihydroxybenzophenone

Directory of Open Access Journals (Sweden)

Bharat C. Dixit

2009-01-01

Full Text Available Novel acid azo and mordent acid azo dyes have been prepared by the coupling of diazo solution of different aminonaphthol sulphonic acids and aromatic amino acids with 2,4-dihydroxybenzophenone. The resultant dyes were characterized by elemental analysis as well as IR and 1H NMR spectral studies. The UV-visible spectral data have also been discussed in terms of structure property relationship. The dyeing assessments of all the dyes were evaluated on wool and silk textile fibers. The dyeing of chrome pretreated wool and silk have also been monitored. The result shows that better hue was obtained on mordented fiber. Results of bactericidal studies of chrome pretreated fibers revealed that the toxicity of mordented dyes against bacteria is fairly good. Dyeing on wool and silk fibers resulted in yellowish pink to reddish brown colourations having excellent light fastness and washing fastness.

Extending the scope of amantadine drug by incorporation of phenolic azo Schiff bases as potent selective inhibitors of carbonic anhydrase II, drug likeness and binding analysis.

Science.gov (United States)

Channar, Pervaiz Ali; Saeed, Aamer; Shahzad, Danish; Larik, Fayaz Ali; Hassan, Mubashir; Raza, Hussain; Abbas, Qamar; Seo, Sung-Yum

2018-05-16

A series of Amantadine based azo Schiff base dyes 6a-6e have been synthesized and characterized by 1 H NMR and 13 C NMR and evaluated for their in vitro carbonic anhydrase II inhibition activity and antioxidant activity. All of the synthesized showed excellent carbonic inhibition. Compound 6b was found to be the most potent derivative in the series, the IC 50 of 6b was found to be 0.0849 ± 0.00245μM (standard Acetazolamide IC 50 =0.9975±0.049μM). The binding interactions of the most active analogs were confirmed through molecular docking studies. Docking studies showed 6b is interacting by making two hydrogen bonds w at His93 and Ser1 residues respectively. All compounds showed a good drug score and followed Lipinski's rule. In summary, our studies have shown that these amantadine derived phenolic azo Schiff base derivatives are a new class of carbonic anhydrase II inhibitors. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Microwave-assisted synthesis of bio-active heterocycles in aqueous media

KAUST Repository

Polshettiwar, Vivek; Varma, Rajender S.

2010-01-01

Synthesis of bio-active heterocycles and fine chemicals in aqueous media are one of the best solutions for the development of green and sustainable protocols. To illustrate the advantages of aqueous MW chemistry in heterocycle synthesis

Green Synthetic Alternatives to Organic Compounds and Nanomaterials

Science.gov (United States)

A brief account of reactions involving microwave (MW) exposure of neat reactants or catalyzed by mineral support surfaces, such as alumina, silica, clay, or their ‘doped’ versions, for the rapid one-pot assembly of heterocyclic compounds from in situ generated reactive intermedia...

Effect of dye structure and redox mediators on anaerobic azo and anthraquinone dye reduction

Directory of Open Access Journals (Sweden)

Mayara Carantino Costa

2012-01-01

Full Text Available We investigated the biological decolourisation of dyes with different molecular structures. The kinetic constant values (k1 achieved with azo dye Reactive Red 120 were 7.6 and 10.1 times higher in the presence of RM (redox mediators AQDS and riboflavin, respectively, than the assays lacking RM. The kinetic constant achieved with the azo dye Congo Red was 42 times higher than that obtained with the anthraquinone dye Reactive Blue 4. The effect of RM on dye reduction was more evident for azo dyes resistant to reductive processes, and ineffective for anthraquinone dyes because of the structural stability of the latter.

Synthesis and Reactions of Five-Membered Heterocycles Using Phase Transfer Catalyst (PTC Techniques

Directory of Open Access Journals (Sweden)

Ahmed M. El-Sayed

2014-01-01

Full Text Available Phase transfer catalysts (PTCs have been widely used for the synthesis of organic compounds particularly in both liquid-liquid and solid-liquid heterogeneous reaction mixtures. They are known to accelerate reaction rates by facilitating formation of interphase transfer of species and making reactions between reagents in two immiscible phases possible. Application of PTC instead of traditional technologies for industrial processes of organic synthesis provides substantial benefits for the environment. On the basis of numerous reports it is evident that phase-transfer catalysis is the most efficient way for generation and reactions of many active intermediates. In this review we report various uses of PTC in syntheses and reactions of five-membered heterocycles compounds and their multifused rings.

Inductively coupled hydrogen plasma processing of AZO thin films for heterojunction solar cell applications

International Nuclear Information System (INIS)

Zhou, H.P.; Xu, S.; Zhao, Z.; Xiang, Y.

2014-01-01

Highlights: • A high-density plasma reactor of inductively coupled plasma source is used in this work. • The conductivity and transmittance can be enhanced simultaneously in the hydrogen process. • The formation of additional donors and passivation due to the hydrogen plasma processing. • The photovoltaic improvement due to the improved AZO layer and hetero-interface quality in the solar cells. - Abstract: Al-doped ZnO (AZO) thin films deposited by means of RF magnetron sputtering were processed in a low frequency inductively coupled plasma of H 2 , aiming at heterojunction (HJ) solar cell applications. A variety of characterization results show that the hydrogen plasma processing exerts a significant influence on the microstructures, electrical and optical properties of the AZO films. The incorporation of hydrogen under the optimum treatment simultaneously promoted the transmittance and conductivity due to the hydrogen associated passivation effect on the native defects and the formation of shallow donors in the films, respectively. A p-type c-Si based HJ solar cell with a front AZO contact was also treated in as-generated non-equilibrium hydrogen plasma and the photovoltaic performance of the solar cell was prominently improved. The underlying mechanism was discussed in terms of the beneficial impacts of high-density hydrogen plasma on the properties of AZO itself and the hetero-interfaces involved in the HJ structure (interface defect and energy band configuration)

Radical fragmentation of six-membered oxygen-containing heterocycles

International Nuclear Information System (INIS)

Petryaev, E.P.; Kosobutskij, V.S.; Shadyro, O.I.

1982-01-01

Using chromatography, the composition and radiation-chemical yields of final products of desctruction of six-member saturated oxygen-containing heterocycles (the effect of #betta#-radiation on aqueous solutions of tetrahydropyran, 1,3-dioxane, 2,2 dimethyl-1,3 dioxane, 1,4-dioxane, paraldehyde) have been determined. It is established that the identified products are formed at the expense of decomposition of primary radicals of the initial compounds and point to the realization of the following fragmentation ways: 1) #betta#-scattering, 2) #betta#-scattering with a subsequent 1,5 migration of an H atom, 3) simultaneous rupture of two vicinal, relative to the radical center, bonds. A formation mechanism of the substances desctruction products is suggested. Material balance of the product yields of 1,3-dioxane radical synchronous decomposition is presented

Electroluminescence enhancement for near-ultraviolet light emitting diodes with graphene/AZO-based current spreading layers

DEFF Research Database (Denmark)

Lin, Li; Ou, Yiyu; Zhu, Xiaolong

LEDs) have attracted significant research interest due to their intensive applications in various areas where indium tin oxide (ITO) is one of the most widely employed transparent conductive materials for NUV LEDs. Compared to ITO, indium-free aluminum-doped zinc oxide (AZO) has similar electrical......Near-ultraviolet light emitting diodes with different aluminum-doped zinc oxide-based current spreading layers were fabricated and electroluminescence (EL) was compared. A 170% EL enhancement was achieved by using a graphene-based interlayer. GaN-based near-ultraviolet light emitting diodes (NUV...... with a new type of current spreading layer (CSL) which combines AZO and a single-layer graphene (SLG) as an effective transparent CSL [1]. In the present work, LEDs with solo AZO CSL in Fig.1(a) and SLG/Ni/AZO-based CSL in Fig.1(b) were both fabricated for EL comparison. Standard mesa fabrication including...

Structure Modification of an Active Azo-Compound as a Route to New Antimicrobial Compounds

Directory of Open Access Journals (Sweden)

Simona Concilio

2017-05-01

Full Text Available Some novel (phenyl-diazenylphenols 3a–g were designed and synthesized to be evaluated for their antimicrobial activity. A previously synthesized molecule, active against bacteria and fungi, was used as lead for modifications and optimization of the structure, by introduction/removal or displacement of hydroxyl groups on the azobenzene rings. The aim of this work was to evaluate the consequent changes of the antimicrobial activity and to validate the hypothesis that, for these compounds, a plausible mechanism could involve an interaction with protein receptors, rather than an interaction with membrane. All newly synthesized compounds were analyzed by 1H-NMR, DSC thermal analysis and UV-Vis spectroscopy. The in vitro minimal inhibitory concentrations (MIC of each compound was determined against Gram-positive and Gram-negative bacteria and Candida albicans. Compounds 3b and 3g showed the highest activity against S. aureus and C. albicans, with remarkable MIC values of 10 µg/mL and 3 µg/mL, respectively. Structure-activity relationship studies were capable to rationalize the effect of different substitutions on the phenyl ring of the azobenzene on antimicrobial activity.

Use of Titanium Dioxide Photocatalysis on the Remediation of Model Textile Wastewaters Containing Azo Dyes

Directory of Open Access Journals (Sweden)

Josino Costa Moreira

2011-12-01

Full Text Available The photocatalytic degradation of two commercial textile azo dyes, namely C.I Reactive Black 5 and C.I Reactive Red 239, has been studied. TiO2 P25 Degussa was used as catalyst and photodegradation was carried out in aqueous solution under artificial irradiation with a 125 W mercury vapor lamp. The effects of the amount of TiO2 used, UV-light irradiation time, pH of the solution under treatment, initial concentration of the azo dye and addition of different concentrations of hydrogen peroxide were investigated. The effect of the simultaneous photodegradation of the two azo dyes was also investigated and we observed that the degradation rates achieved in mono and bi-component systems were identical. The repeatability of photocatalytic activity of the photocatalyst was also tested. After five cycles of TiO2 reuse the rate of colour lost was still 77% of the initial rate. The degradation was followed monitoring the change of azo dye concentration by UV-Vis spectroscopy. Results show that the use of an efficient photocatalyst and the adequate selection of optimal operational parameters may easily lead to a complete decolorization of the aqueous solutions of both azo dyes.

Synthesis and Biological Activity Evaluation of Novel Heterocyclic Pleuromutilin Derivatives

Directory of Open Access Journals (Sweden)

Yunpeng Yi

2017-06-01

Full Text Available A series of pleuromutilin derivatives were synthesized by two synthetic procedures under mild reaction conditions and characterized by Nuclear Magnetic Resonance (NMR, Infrared Spectroscopy (IR, and High Resolution Mass Spectrometer (HRMS. Most of the derivatives with heterocyclic groups at the C-14 side of pleuromutilin exhibited excellent in vitro antibacterial activities against Staphylococcus aureus, methicillin-resistant Staphylococcus aureus (MRSA, methicillin-resistant Staphylococcus epidermidis (MRSE, and vancomycin-resistant Enterococcus (VRE in vitro antibacterial activity. The synthesized derivatives which contained pyrimidine rings, 3a, 3b, and 3f, displayed modest antibacterial activities. Compound 3a, the most active antibacterial agent, displayed rapid bactericidal activity and affected bacterial growth in the same manner as that of tiamulin fumarate. Moreover, molecular docking studies of 3a and lefamulin provided similar information about the interactions between the compounds and 50S ribosomal subunit. The results of the study show that pyrimidine rings should be considered in the drug design of pleuromutilin derivatives.

Cyclodepsipeptides and Other O-Containing Heterocyclic Metabolites from Beauveria felina EN-135, a Marine-Derived Entomopathogenic Fungus

Directory of Open Access Journals (Sweden)

Feng-Yu Du

2014-05-01

Full Text Available Bioassay-guided fractionation of a culture extract of Beauveria felina EN-135, an entomopathogenic fungus isolated from a marine bryozoan, led to the isolation of a new cyclodepsipeptide, iso-isariin D (1; two new O-containing heterocyclic compounds that we have named felinones A and B (2 and 3; and four known cyclodepsipeptides (4–7. The structures were elucidated via spectroscopic analysis, and the absolute configurations of 1 and 2 were determined using single-crystal X-ray diffraction and CD, respectively. All isolated compounds were evaluated for antimicrobial activity and brine-shrimp (Artemia salina lethality.

Binding to the DNA Minor Groove by Heterocyclic Dications: From AT Specific Monomers to GC Recognition with Dimers

Science.gov (United States)

Nanjunda, Rupesh; Wilson, W. David

2012-01-01

Compounds that bind in the DNA minor groove have provided critical information on DNA molecular recognition, they have found extensive uses in biotechnology and they are providing clinically useful drugs against diseases as diverse as cancer and sleeping sickness. This review focuses on the development of clinically useful heterocyclic diamidine minor groove binders. These compounds have shown us that the classical model for minor groove binding in AT DNA sequences must be expanded in several ways: compounds with nonstandard shapes can bind strongly to the groove, water can be directly incorporated into the minor groove complex in an interfacial interaction, and the compounds can form cooperative stacked dimers to recognize GC and mixed AT/GC base pair sequences. PMID:23255206

Comparative study on reaction selectivity of azo dye decolorization by Pseudomonas luteola

International Nuclear Information System (INIS)

Hsueh, C.-C.; Chen, B.-Y.

2007-01-01

This study is to inspect how the variation of molecular structures and functional groups present in our model azo dyes (i.e., Congo red, Eriochrome black T (EBT), methyl orange, and methyl red) affects biodecolorization capability of Pseudomonas luteola. The most viable decolorization was found at pH 7-9 and the optimal cellular age for the most effective decolorization was 7 days after static incubation in dye-free cultures. In decolorization, the maximal absorption wavelength in UV-vis spectra for the different dye-containing cultures shifted from visible light range towards the ultraviolet visible range. Methyl red was not decolorized in contrast to methyl orange, Congo red, and Eriochrome black T. The sulfonic group para to azo bond (-N=N-) in methyl orange was a strong electron-withdrawing group through resonance to cause an enhancement of color removal to be easily biodecolorized. As a charged carboxyl group on methyl red is at ortho position (i.e., in the proximity) to azo bond, this led to a complete inhibition to decolorization. However, decolorization of Congo red and EBT in the absence of charged group (e.g., hydroxy or amino group) near azo bond was not completely repressed like methyl red. Thus, the presence of electron-withdrawing groups as the substituents on azo dyes enhanced decolorization capability for biodegradability. In addition, Monod kinetic model provided better predictions to all dye decolorization at initial short periods of time due to negligible intermediate formed at initial short time duration, but significant intermediate accumulation took place at longer period of time. In contrast, the decolorization performances of methyl orange at 400 ppm and EBT at 230 ppm were significantly less than those predicted from the Monod kinetic model likely due to accumulated intermediates exceeding the threshold levels for feedback inhibition

Effect of silver nanoparticles on photo-induced reorientation of azo groups in polymer films

International Nuclear Information System (INIS)

Zhou Jingli; Yang Jianjun; Sun Youyi; Zhang Douguo; Shen Jing; Zhang Qijin; Wang Keyi

2007-01-01

A series of polymer films containing azo groups and silver nanoparticles were prepared. Photo-induced reorientation of the film was conducted under irradiation of polarized light with wavelength at 365 nm, 442 nm and 532 nm, respectively. The influence of the concentration of dopant silver on the reorientation of the azo groups was studied. An enhancement of about 50% for the reorientation rate and about 70% for the reorientation amplitude was achieved. From a comparison of the enhancement obtained by irradiating with three different light sources, it was realized that the mechanism for enhancement of reorientation of azo groups is due to plasmon resonance of silver nanoparticles doped in the polymer films

Impact of self-assembled monolayer assisted surface dipole modulation of PET substrate on the quality of RF-sputtered AZO film

Energy Technology Data Exchange (ETDEWEB)

Vo, Thieu Thi Tien [Department of Chemical Engineering, National Taiwan University of Science and Technology, Taipei 10607, Taiwan (China); Faculty of Chemical Engineering and Food Technology, Ba Ria-Vung Tau University, Vung Tau (Viet Nam); Mahesh, K.P.O. [Department of Chemical Engineering, National Taiwan University of Science and Technology, Taipei 10607, Taiwan (China); Lin, Pao-Hung [Department of Electronic and Computer Engineering, National Taiwan University of Science and Technology, Taipei 10607, Taiwan (China); Tai, Yian, E-mail: ytai@mail.ntust.edu.tw [Department of Chemical Engineering, National Taiwan University of Science and Technology, Taipei 10607, Taiwan (China)

2017-05-01

Highlights: • We use SAMs functionalizing the PET substrates to generate different surface dipoles. • We deposited AZO film on pristine and SAMs-modified PET substrate. • The positive dipole moment of PET surface promotes the crystallinity of AZO film. • The negative dipole moment of PET surface deteriorates the crystallinity of AZO film. • The electrical properties of AZO/PET changes upon the variation of the crystallinity. - Abstract: In this study, we fabricated the electron donating/withdrawing group functionalized organosilane self-assembled monolayers (SAMs) on transparent polyethylene terephthalate (PET) flexible substrate followed by the deposition of aluminum doped zinc oxide (AZO) using RF magnetron sputtering at room temperature. The effect of different SAMs on transparent PET substrates and AZO films were studied by contact angle (CA), X-ray photoelectron spectroscopy (XPS), Atomic force microscopy (AFM), X-ray diffraction (XRD), Field-Emission scanning electron microscope (FE-SEM), Hall measurement and UV–vis spectroscopy (UV–vis). The results presented that the surface dipole (i.e. electron-donating/withdrawing) of different SAMs functionalized PET substrates affected the quality of the AZO films which deposited on top of them. The crystallinity, the charge mobility, and the carrier concentration of the AZO improved when the film was deposited on the PET functionalized with electron donating group, which was possibly due to favored interaction between electron donating group and Al ions.

Impact of self-assembled monolayer assisted surface dipole modulation of PET substrate on the quality of RF-sputtered AZO film

International Nuclear Information System (INIS)

Vo, Thieu Thi Tien; Mahesh, K.P.O.; Lin, Pao-Hung; Tai, Yian

2017-01-01

Highlights: • We use SAMs functionalizing the PET substrates to generate different surface dipoles. • We deposited AZO film on pristine and SAMs-modified PET substrate. • The positive dipole moment of PET surface promotes the crystallinity of AZO film. • The negative dipole moment of PET surface deteriorates the crystallinity of AZO film. • The electrical properties of AZO/PET changes upon the variation of the crystallinity. - Abstract: In this study, we fabricated the electron donating/withdrawing group functionalized organosilane self-assembled monolayers (SAMs) on transparent polyethylene terephthalate (PET) flexible substrate followed by the deposition of aluminum doped zinc oxide (AZO) using RF magnetron sputtering at room temperature. The effect of different SAMs on transparent PET substrates and AZO films were studied by contact angle (CA), X-ray photoelectron spectroscopy (XPS), Atomic force microscopy (AFM), X-ray diffraction (XRD), Field-Emission scanning electron microscope (FE-SEM), Hall measurement and UV–vis spectroscopy (UV–vis). The results presented that the surface dipole (i.e. electron-donating/withdrawing) of different SAMs functionalized PET substrates affected the quality of the AZO films which deposited on top of them. The crystallinity, the charge mobility, and the carrier concentration of the AZO improved when the film was deposited on the PET functionalized with electron donating group, which was possibly due to favored interaction between electron donating group and Al ions.

Using chemical wet-etching methods of textured AZO films on a-Si:H solar cells for efficient light trapping

Energy Technology Data Exchange (ETDEWEB)

Lin, Guo-Sheng; Li, Chien-Yu; Huang, Kuo-Chan; Houng, Mau-Phon, E-mail: mphoung@eembox.ncku.edu.tw

2015-06-15

In this paper, Al-doped ZnO (AZO) films are deposited on glasses substrate by RF magnetron sputtering. The optical, electrical and morphological properties of AZO films textured by wet-etching with different etchants, H{sub 3}PO{sub 4}, HCl, and HNO{sub 3} are studied. It is found that the textured structure could enhance the light scattering and light trapping ability of amorphous silicon solar cells. The textured AZO film etched with HNO{sub 3} exhibits optimized optical properties (T% ≧ 80% over entire wavelength, haze ratio > 40% at 550 nm wavelength) and excellent electrical properties (ρ = 5.86 × 10{sup −4} Ωcm). Scanning electron microscopy and Atomic force microscopy are used to observe surface morphology and average roughness of each textured AZO films. Finally, the textured AZO films etched by H{sub 3}PO{sub 4}, HCl and HNO{sub 3} were applied to front electrode layer for p–i–n amorphous silicon solar cells. The highest conversion efficiency of amorphous silicon solar cell fabricated on HNO{sub 3}-etched AZO film was 7.08% with open-circuit voltage, short-circuit current density and fill factor of 895 mV, 14.92 mA/cm{sup 2} and 0.56, respectively. It shows a significantly enhancement in the short-circuit current density and conversion efficiency by 16.2% and 20.2%, respectively, compared with the solar cell fabricated on as-grown AZO film. - Highlights: • The textured surface enhances light scattering and light trapping ability. • The HNO{sub 3}-etched AZO film exhibits excellent optical and electrical properties. • The efficiency of a-Si:H solar cell fabricated on HNO{sub 3}-etched AZO film was 7.08%. • The short-circuit current density enhances to 16.2%. • The conversion efficiency enhances to 20.2%.

Using chemical wet-etching methods of textured AZO films on a-Si:H solar cells for efficient light trapping

International Nuclear Information System (INIS)

Lin, Guo-Sheng; Li, Chien-Yu; Huang, Kuo-Chan; Houng, Mau-Phon

2015-01-01

In this paper, Al-doped ZnO (AZO) films are deposited on glasses substrate by RF magnetron sputtering. The optical, electrical and morphological properties of AZO films textured by wet-etching with different etchants, H 3 PO 4 , HCl, and HNO 3 are studied. It is found that the textured structure could enhance the light scattering and light trapping ability of amorphous silicon solar cells. The textured AZO film etched with HNO 3 exhibits optimized optical properties (T% ≧ 80% over entire wavelength, haze ratio > 40% at 550 nm wavelength) and excellent electrical properties (ρ = 5.86 × 10 −4 Ωcm). Scanning electron microscopy and Atomic force microscopy are used to observe surface morphology and average roughness of each textured AZO films. Finally, the textured AZO films etched by H 3 PO 4 , HCl and HNO 3 were applied to front electrode layer for p–i–n amorphous silicon solar cells. The highest conversion efficiency of amorphous silicon solar cell fabricated on HNO 3 -etched AZO film was 7.08% with open-circuit voltage, short-circuit current density and fill factor of 895 mV, 14.92 mA/cm 2 and 0.56, respectively. It shows a significantly enhancement in the short-circuit current density and conversion efficiency by 16.2% and 20.2%, respectively, compared with the solar cell fabricated on as-grown AZO film. - Highlights: • The textured surface enhances light scattering and light trapping ability. • The HNO 3 -etched AZO film exhibits excellent optical and electrical properties. • The efficiency of a-Si:H solar cell fabricated on HNO 3 -etched AZO film was 7.08%. • The short-circuit current density enhances to 16.2%. • The conversion efficiency enhances to 20.2%

Infrared Spectroscopy of Matrix-Isolated Polycyclic Aromatic Nitrogen Heterocycles (PANHs)

Science.gov (United States)

Mattioda, A. L.; Hudgins, D. M.; Bauschlicher, C. W.; Allamandola, L. J.; Biemesderfer, C. D.; Rosi, M.

2002-01-01

The mid-infrared spectra of the nitrogen-containing heterocyclic polycyclic aromatic compounds 1-azabenz[a]-anthracene; 2-azabenz[a]anthracene; 1-azachrysene; 2-azachrysene; 4-azachrysene; 2-azapyrene, and 7,8 benzoquinoline in their neutral and cation forms were investigated. The spectra of these species isolated in an argon matrix have been measured. Band frequencies and intensities were tabulated and these data compared with spectra computed using density functional theory at the B3LYP level. The overall agreement between experiment and theory is quite good, in keeping with earlier results on homonuclear polycyclic aromatic hydrocarbons. The differences between the spectral properties of nitrogen bearing aromatics and non-substituted, neutral polycyclic aromatic hydrocarbons will be discussed.

Effect of Reactive Black 5 azo dye on soil processes related to C and N cycling

Directory of Open Access Journals (Sweden)

Khadeeja Rehman

2018-05-01

Full Text Available Azo dyes are one of the largest classes of synthetic dyes being used in textile industries. It has been reported that 15–50% of these dyes find their way into wastewater that is often used for irrigation purpose in developing countries. The effect of azo dyes contamination on soil nitrogen (N has been studied previously. However, how does the azo dye contamination affect soil carbon (C cycling is unknown. Therefore, we assessed the effect of azo dye contamination (Reactive Black 5, 30 mg kg−1 dry soil, bacteria that decolorize this dye and dye + bacteria in the presence or absence of maize leaf litter on soil respiration, soil inorganic N and microbial biomass. We found that dye contamination did not induce any change in soil respiration, soil microbial biomass or soil inorganic N availability (P > 0.05. Litter evidently increased soil respiration. Our study concludes that the Reactive Black 5 azo dye (applied in low amount, i.e., 30 mg kg−1 dry soil contamination did not modify organic matter decomposition, N mineralization and microbial biomass in a silty loam soil.

Decolorization of azo dyes (Direct Blue 151 and Direct Red 31 by moderately alkaliphilic bacterial consortium

Directory of Open Access Journals (Sweden)

Sylvine Lalnunhlimi

2016-03-01

Full Text Available Abstract Removal of synthetic dyes is one of the main challenges before releasing the wastes discharged by textile industries. Biodegradation of azo dyes by alkaliphilic bacterial consortium is one of the environmental-friendly methods used for the removal of dyes from textile effluents. Hence, this study presents isolation of a bacterial consortium from soil samples of saline environment and its use for the decolorization of azo dyes, Direct Blue 151 (DB 151 and Direct Red 31 (DR 31. The decolorization of azo dyes was studied at various concentrations (100–300 mg/L. The bacterial consortium, when subjected to an application of 200 mg/L of the dyes, decolorized DB 151 and DR 31 by 97.57% and 95.25% respectively, within 5 days. The growth of the bacterial consortium was optimized with pH, temperature, and carbon and nitrogen sources; and decolorization of azo dyes was analyzed. In this study, the decolorization efficiency of mixed dyes was improved with yeast extract and sucrose, which were used as nitrogen and carbon sources, respectively. Such an alkaliphilic bacterial consortium can be used in the removal of azo dyes from contaminated saline environment.

Novel bio-electro-Fenton technology for azo dye wastewater treatment using microbial reverse-electrodialysis electrolysis cell

DEFF Research Database (Denmark)

Li, Xiaohu; Jin, Xiangdan; Zhao, Nannan

2017-01-01

Development of sustanaible technologies for treatment of azo dyes containing wastewaters has long been of great interest. In this study, we proposed an innovative concept of using microbial reverse-electrodialysis electrolysis cell (MREC) based Fenton process to treat azo dye wastewater. In such ......Development of sustanaible technologies for treatment of azo dyes containing wastewaters has long been of great interest. In this study, we proposed an innovative concept of using microbial reverse-electrodialysis electrolysis cell (MREC) based Fenton process to treat azo dye wastewater....... In such MREC-Fenton integrated process, the production of H2O2 which is the key reactant of fenton-reaction was driven by the electrons harvested from the exoelectrogens and salinity-gradient between sea water and fresh water in MREC. Complete decolorization and mineralization of 400 mg L-1 Orange G...

synthesis and labelling of some nitrogenous heterocyclic compounds

International Nuclear Information System (INIS)

Mahmoud, A.A.L.

2002-01-01

the imidazole nucleus has wide range of pharmaceutical activities . also , radioiodinated compounds are used in nuclear medicine. this thesis deals with the synthesis of 2-(iodophenyl)-4-oxazoline-5-ons e, which are used as starting materials in the synthesis of the corresponding imidazolinone derivatives. also, it deals with radioiodination f the synthesized compounds to evaluate their application in nuclear medicine. interaction of o- iodo hippuric acid (I) with aromatic aldehydes (i.e., benzaldehyde, p- methoxybenzaldehyde and p- nitrobenzaldehyde) in acetic anhydride and in the presence of fused sodium acetate effected cyclization to afford the corresponding 2-(2-iodophenyl)-4-arylidene- 2-oxazoline-5-ones(l l a-c )

A review on bis-hydrazonoyl halides: Recent advances in their synthesis and their diverse synthetic applications leading to bis-heterocycles of biological interest

Directory of Open Access Journals (Sweden)

Ahmad Sami Shawali

2016-11-01

Full Text Available This review covers a summary of the literature data published on the chemistry of bis-hydrazonoyl halides over the last four decades. The biological activities of some of the bis-heterocyclic compounds obtained from these bis-hydrazonoyl halides are also reviewed and discussed.

Heterocyclic aramid nanoparticle-assisted graphene exfoliation for fabrication of pristine graphene-based composite paper

Energy Technology Data Exchange (ETDEWEB)

Mo, Yao; Liu, Qi; Fan, Jinchen, E-mail: Jinchen.fan@shiep.edu.cn; Shi, Penghui; Min, Yulin, E-mail: ahaqmylin@126.com; Xu, Qunjie [Shanghai University of Electric Power, Shanghai Key Laboratory of Materials Protection and Advanced Materials in Electric Power, College of Environmental and Chemical Engineering (China)

2015-07-15

Mechanically strong, electrically conductive, and flexible pristine graphene-based composite paper was prepared based on heterocyclic aramid nanoparticle-assisted liquid-phase exfoliation of graphite. The macroscopic heterocyclic aramid yarns were split and assembled into heterocyclic aramid nanoparticles with the size of ∼30 nm by deprotonation in dimethylsulfoxide in the presence of potassium hydroxide. The obtained heterocyclic aramid nanoparticles dimethylsulfoxide dispersion was used as good medium solvent for highly efficiency liquid-phase exfoliation of graphite. The results demonstrated that the concentration of exfoliated graphene can facile reaches ∼2.72 mg/mL after direct sonication of 7 h with assist of heterocyclic aramid nanoparticles. After exfoliation, the self-assembled pristine graphene-based composite paper was fabricated by vacuum-assisted filtration. Due to the introduction of heterocyclic aramid nanoparticles, the self-assembled pristine graphene/heterocyclic aramid nanoparticles composite paper exhibited good mechanical property with tensile strength of ∼129.7 MPa, meantime, has a high electrical conductivity of ∼1.42 × 10{sup 4} S/m.

Heterocyclic aramid nanoparticle-assisted graphene exfoliation for fabrication of pristine graphene-based composite paper

International Nuclear Information System (INIS)

Mo, Yao; Liu, Qi; Fan, Jinchen; Shi, Penghui; Min, Yulin; Xu, Qunjie

2015-01-01

Mechanically strong, electrically conductive, and flexible pristine graphene-based composite paper was prepared based on heterocyclic aramid nanoparticle-assisted liquid-phase exfoliation of graphite. The macroscopic heterocyclic aramid yarns were split and assembled into heterocyclic aramid nanoparticles with the size of ∼30 nm by deprotonation in dimethylsulfoxide in the presence of potassium hydroxide. The obtained heterocyclic aramid nanoparticles dimethylsulfoxide dispersion was used as good medium solvent for highly efficiency liquid-phase exfoliation of graphite. The results demonstrated that the concentration of exfoliated graphene can facile reaches ∼2.72 mg/mL after direct sonication of 7 h with assist of heterocyclic aramid nanoparticles. After exfoliation, the self-assembled pristine graphene-based composite paper was fabricated by vacuum-assisted filtration. Due to the introduction of heterocyclic aramid nanoparticles, the self-assembled pristine graphene/heterocyclic aramid nanoparticles composite paper exhibited good mechanical property with tensile strength of ∼129.7 MPa, meantime, has a high electrical conductivity of ∼1.42 × 10 4  S/m.

A brief review on synthesis & applications of β-enamino carbonyl compounds

Directory of Open Access Journals (Sweden)

yellajyosula L N Murthy

2012-01-01

Full Text Available Owing to the wide range applications of β-enamino esters (enamines of β–dicarbonyl compounds in pharmaceuticals and as building blocks for the synthesis of a variety of heterocyclic compounds, β-amino esters, β-amino acids, γ-amino alcohols, peptides and alkaloids a number of methods have been developed so far for the synthesis of these compounds. Due to the importance of these compounds as intermediates in organic synthesis, a concised review is presented.

Novel colorimetric sensors for cyanide based on azo-hydrazone tautomeric skeletons.

Science.gov (United States)

Adegoke, Olajire A; Adesuji, Temitope E; Thomas, Olusegun E

2014-07-15

The monoazo dyes, 4-carboxyl-2, 6-dinitrophenylazohydroxynaphthalenes dyes (AZ-01, AZ-03 and AZ-04), were evaluated as a highly selective colorimetric chemosensor for cyanide ion. The recognition of cyanide ion gave an obvious colour change from light yellow to brownish red and upon dilution with acetone produced a purple to lilac colour. Optimum conditions for the reaction between the azo dyes and cyanide ion were established at 30°C for 5 min, and different variables affecting the reaction were carefully studied and optimised. Under the optimum conditions, linear relationships between the CN(-) concentrations and light absorption were established. Using these azo-hydrazone molecular switch entities, excellent selectivity towards the detection of CN(-) in aqueous solution over miscellaneous competitive anions was observed. Such selectivity mainly results from the possibility of nucleophilic attack on the azo-hydrazone chemosensors by cyanide anions in aqueous system, which is not afforded by other competing anions. The cyanide chemosensor method described here should have potential application as a new family probes for detecting cyanide in aqueous solution. Copyright © 2014 Elsevier B.V. All rights reserved.

Dimerisation, rhodium complex formation and rearrangements of N-heterocyclic carbenes of indazoles

Directory of Open Access Journals (Sweden)

Zong Guan

2014-04-01

Full Text Available Deprotonation of indazolium salts at low temperatures gives N-heterocyclic carbenes of indazoles (indazol-3-ylidenes which can be trapped as rhodium complexes (X-ray analysis. In the absence of Rh, the indazol-3-ylidenes spontaneously dimerize under ring cleavage of one of the N,N-bonds and ring closure to an indazole–indole spiro compound which possesses an exocyclic imine group. The E/Z isomers of the imines can be separated by column chromatography when methanol is used as eluent. We present results of a single crystal X-ray analysis of one of the E-isomers, which equilibrate in solution as well as in the solid state. Heating of the indazole–indole spiro compounds results in the formation of quinazolines by a ring-cleavage/ring-closure sequence (X-ray analysis. Results of DFT calculations are presented.

Gold-catalyzed heterocyclizations in alkynyl- and allenyl-β-lactams

Directory of Open Access Journals (Sweden)

Pedro Almendros

2011-05-01

Full Text Available New gold-catalyzed methods using the β-lactam scaffold have been recently developed for the synthesis of different sized heterocycles. This overview focuses on heterocyclization reactions of allenic and alkynic β-lactams which rely on the activation of the allene and alkyne component. The mechanism as well as the regio- and stereoselectivity of the cyclizations are also discussed.

ADSORPSI-DESORPSI ZAT WARNA AZO JENIS REMAZOL BLACK B MENGGUNAKAN MEMBRAN POLIELEKTROLIT (PEC KITOSAN-PEKTIN

Directory of Open Access Journals (Sweden)

Ni Putu Sri Ayuni

2016-08-01

Full Text Available Abstrak Sekitar 2-50% dari zat warna azo yang digunakan selama proses pencelupan ini tidak mengikat serat dan langsung dilepaskan ke lingkungan melalui instalasi pengolahan limbah. Hal ini perlu dilakukan pengolahan limbah cair yang mengandung zat warna azo jenis Remazol Black B sebelum dibuang ke lingkungan. Penelitian ini bertujuan untuk mengetahui kondisi optimum membran PEC kitosan-pektin yang dapat digunakan untuk mengadsorpsi zat warna azo jenis Remazol Black B .Untuk memperoleh kondisi optimum akan dilakukan adsorpsi zat warna azo jenis Remazol Black B dengan variasi waktu kontak (5-150 menit, pH (5-9 dan konsentrasi larutan zat warna azo jenis Remazol Black B (5, 10, 15, 20, dan 25 mg/L. Untuk mengetahui karakteristik zat warna jenis Remazol Black B oleh membran PEC kitosan-pektin di analisis dengan persamaan isoterm adsorpsi Langmuir dan isoterm adsorpsi Freundlich sedangkan daya adsorpsi maksimum dari membran PEC kitosan pektin ditentukan dari kurva berdasarkan karakteristik membran yang diperoleh. Hasil penelitian menunjukkan bahwa adsorpsi zat warna azo jenis Remazol Black B terjadi pada kondisi optimum dengan pH 5, waktu 120 menit dan konsentrasi larutan zat warna azo jenis Remazol Black B 10 mg/L (62,75 %. Pola adsorpsi mengikuti pola adsorpsi isoterm Freundlich dengan daya adsorpsi maksimum 0,02 (mg/g. Untuk efisiensi desorpsi maksimal diperoleh pada larutan NaCl 1 M (11,17 % Kata Kunci: adsorpsi, membran polielektrolit kitosan pektin, Remazol Black B Abstract Azo dyes produced approximately 2-50% from dying process were thrown through effluent to the environment without any treatment. The objective of this research were to know the optimum condition of PEC chitosan pectin membrane using to adsorp Remazol Black B with various contact time (5-150 min, pH (5-9 and Remazol Black B concentration (5, 10, 15, 20, dan 25 mg/L. Adsorption charactheristic of Remazol Black B by PEC chitosan pectin membrane were determined by Langmuir and

Atomic-Layer-Deposited AZO Outperforms ITO in High-Efficiency Polymer Solar Cells

KAUST Repository

Kan, Zhipeng

2018-05-11

Tin-doped indium oxide (ITO) transparent conducting electrodes are widely used across the display industry, and are currently the cornerstone of photovoltaic device developments, taking a substantial share in the manufacturing cost of large-area modules. However, cost and supply considerations are set to limit the extensive use of indium for optoelectronic device applications and, in turn, alternative transparent conducting oxide (TCO) materials are required. In this report, we show that aluminum-doped zinc oxide (AZO) thin films grown by atomic layer deposition (ALD) are sufficiently conductive and transparent to outperform ITO as the cathode in inverted polymer solar cells. Reference polymer solar cells made with atomic-layer-deposited AZO cathodes, PCE10 as the polymer donor and PC71BM as the fullerene acceptor (model systems), reach power conversion efficiencies of ca. 10% (compared to ca. 9% with ITO-coated glass), without compromising other figures of merit. These ALD-grown AZO electrodes are promising for a wide range of optoelectronic device applications relying on TCOs.

Atomic-Layer-Deposited AZO Outperforms ITO in High-Efficiency Polymer Solar Cells

KAUST Repository

Kan, Zhipeng; Wang, Zhenwei; Firdaus, Yuliar; Babics, Maxime; Alshareef, Husam N.; Beaujuge, Pierre

2018-01-01

Tin-doped indium oxide (ITO) transparent conducting electrodes are widely used across the display industry, and are currently the cornerstone of photovoltaic device developments, taking a substantial share in the manufacturing cost of large-area modules. However, cost and supply considerations are set to limit the extensive use of indium for optoelectronic device applications and, in turn, alternative transparent conducting oxide (TCO) materials are required. In this report, we show that aluminum-doped zinc oxide (AZO) thin films grown by atomic layer deposition (ALD) are sufficiently conductive and transparent to outperform ITO as the cathode in inverted polymer solar cells. Reference polymer solar cells made with atomic-layer-deposited AZO cathodes, PCE10 as the polymer donor and PC71BM as the fullerene acceptor (model systems), reach power conversion efficiencies of ca. 10% (compared to ca. 9% with ITO-coated glass), without compromising other figures of merit. These ALD-grown AZO electrodes are promising for a wide range of optoelectronic device applications relying on TCOs.

TiO2/beads as a photocatalyst for the degradation of X3B azo dye

Institute of Scientific and Technical Information of China (English)

无

2003-01-01

The feasibility of photocatalytic degradation of X3B azo dye by TiO2/beads photocatalyst was studied. The effects of parameters such as the amount of TiO2/beads, airflow, as well as the concentrations of H2O2, Fe3+, Mg2+ and Na+ on the photocatalytic degradation of X3B azo dye were also studied. The results showed that 25 mg/dm3 X3B azo dye can be photocatalytically degraded completely by 30 min illumination with a 375W medium pressure mercury lamp. Adding a small amount of H2O2 or Fe3+, the efficiencies of photocatalytic degradation of X3B azo dye were increased rapidly. The mechanisms of the reaction and the role of the additives were also investigated. After 120 hours TiO2/beads showed no significant loss of the photocatalytic activity.

Novel acid mono azo dye compound: Synthesis, characterization, vibrational, optical and theoretical investigations of 2-[(E)-(8-hydroxyquinolin-5-yl)-diazenyl]-4,5-dimethoxybenzoic acid

Science.gov (United States)

Saçmacı, Mustafa; Çavuş, Hatice Kanbur; Arı, Hatice; Şahingöz, Recep; Özpozan, Talat

2012-11-01

Novel acid mono azo dye, 2-[(E)-(8-hydroxyquinolin-5yl)-diazenyl]-4,5-dimethoxybenzoic acid (HQD), was synthesized by coupling diazonium salt solution of 2-amino-4,5-dimethoxybenzoic acid (DMA) with 8-hydroxyquinoline (HQ). This dye was characterized by UV-vis, IR & Raman, 1H and 13C NMR spectroscopic techniques and elemental analysis. The normal coordinate analysis of HQD was also performed to assign each band in vibrational spectra. DFT (B3LYP and B3PW91) calculations were employed to optimize the geometry, to interpret NMR spectra, to calculate and to determine the stable tautomeric structure of the compound. Natural Bond Orbital (NBO) analysis was performed to investigate intramolecular interactions. The vibrational spectral data obtained from solid phase IR & Raman spectra were assigned based on the results of the theoretical calculations. UV-vis spectroscopic technique was employed to obtain the optical band gap of HQD. The analysis of the optical absorption data revealed the existence of direct and indirect transitions in the optical band gaps. The optical band gaps of HQD have been found 1.95 and 1.90 eV for direct and indirect transitions, respectively.

Heterocyclic amines in meat and meat products

Directory of Open Access Journals (Sweden)

Aliye BULGAN

2013-06-01

Full Text Available Heterocyclic amines (HA are the mutagenic/carcinogenic compounds which generate as a result of cooking of red meat, poultry meat and fish fillets at high temperatures. Up to 20 different HAs were detected and classified in the researches that conducted on these types of meats cooked at high temperatures. HAs are the products of Maillard reactions and the Strecker degredation of main precursors such as creatine/creatinine, aminoacid and the polysaccharides. Many physical and chemical factors effect the formation of HAs. Thus, it was reported by many researchers that utilizing coating and marination processes in addition to using natural and synthetic antioxidants and seasonings-plant extracts were effective on inhibiting/decreasing the formation of HAs. Additionally, boiling/steaming and microwave cooking methodologies were recommended instead of barbecuing, grilling or frying to inhibit/decrease the formation of HAs. The HAs formed in meat and meat products and the factors which have effects on the formation of HAs are presented in this review.

Anti-Candida albicans biofilm effect of novel heterocyclic compounds.

Science.gov (United States)

Kagan, Sarah; Jabbour, Adel; Sionov, Edward; Alquntar, Abed A; Steinberg, Doron; Srebnik, Morris; Nir-Paz, Ran; Weiss, Aryeh; Polacheck, Itzhack

2014-02-01

The aims of this study were to develop new anti-biofilm drugs, examine their activity against Candida albicans biofilm and investigate their structure-activity relationship and mechanism of action. A series of thiazolidinedione and succinimide derivatives were synthesized and their ability to inhibit C. albicans biofilm formation and destroy pre-formed biofilm was tested. The biofilms' structure, metabolic activity and viability were determined by XTT assay and propidium iodide and SYTO 9 live/dead stains combined with confocal microscopic analysis. The effect of the most active compounds on cell morphology, sterol distribution and cell wall morphology and composition was then determined by specific fluorescent stains and transmission electron microscopy. Most of the compounds were active at sub-MICs. Elongation of the aliphatic side chain resulted in reduced anti-biofilm activity and the sulphur atom contributed to biofilm killing, indicating a structure-activity relationship. The compounds differed in their effects on biofilm viability, yeast-to-hyphal form transition, hyphal morphology, cell wall morphology and composition, and sterol distribution. The most effective anti-biofilm compounds were the thiazolidinedione S8H and the succinimide NA8. We developed novel anti-biofilm agents that both inhibited and destroyed C. albicans biofilm. With some further development, these agents might be suitable for therapeutic purposes.

Synthesis and antitumor evaluation of thiophene based azo dyes incorporating pyrazolone moiety

Directory of Open Access Journals (Sweden)

Moustafa A. Gouda

2016-03-01

Full Text Available A series of thiophene incorporating pyrazolone moieties 5a–f and 6a–c were synthesized via diazo coupling of diazonium salt of 3-substituted-2-amino-4,5,6,7-tetrahydrobenzo[b]thiophenes 1a–c with 3-methyl-1H-pyrazol-5(4H-one, 3-methyl-1-phenyl-1H-pyrazol-5(4H-one or 3-amino-1H-pyrazol-5(4H-one, respectively. Newly synthesized dyes were applied to polyester fabric as disperse dyes in which their color measurements and fastness properties were evaluated. These dyes showed generally red to blue shifted color with high extinction coefficient in comparison with aniline-based azo dyes. The antitumor activity of the synthesized dyes was evaluated. The results showed clearly that most of them exhibited good activity and compounds 5c and 5d exhibited moderate activity.

Synthesis and characterization of azo-guanidine based alcoholic media naked eye DNA sensor

Science.gov (United States)

Hashmat, Uzma; Yousaf, Muhammad; Lal, Bhajan; Ullah, Shafiq; Holder, Alvin A.; Badshah, Amin

2016-01-01

DNA sensing always has an open meadow of curiosity for biotechnologists and other researchers. Recently, in this field, we have introduced an emerging class of molecules containing azo and guanidine functionalities. In this study, we have synthesized three new compounds (UA1, UA6 and UA7) for potential application in DNA sensing in alcoholic medium. The synthesized materials were characterized by elemental analysis, FTIR, UV-visible, 1H NMR and 13C NMR spectroscopies. Their DNA sensing potential were investigated by UV-visible spectroscopy. The insight of interaction with DNA was further investigated by electrochemical (cyclic voltammetry) and hydrodynamic (viscosity) studies. The results showed that compounds have moderate DNA binding properties, with the binding constants range being 7.2 × 103, 2.4 × 103 and 0.2 × 103 M−1, for UA1, UA6 and UA7, respectively. Upon binding with DNA, there was a change in colour (a blue shift in the λmax value) which was observable with a naked eye. These results indicated the potential of synthesized compounds as DNA sensors with detection limit 1.8, 5.8 and 4.0 ng µl−1 for UA1, UA6 and UA7, respectively. PMID:28018613

Green Synthetic Alternatives to Organic Compounds and Nanomaterials-May 2008

Science.gov (United States)

A brief account of reactions involving microwave (MW) exposure of neat reactants or catalyzed by mineral support surfaces, such as alumina, silica, clay, or their ‘doped’ versions, for the rapid one-pot assembly of heterocyclic compounds from in situ generated reactive intermedia...

Amino substituted nitrogen heterocycle ureas as kinase insert domain containing receptor (KDR inhibitors: Performance of structure–activity relationship approaches

Directory of Open Access Journals (Sweden)

Hayriye Yilmaz

2015-06-01

Full Text Available A quantitative structure–activity relationship (QSAR study was performed on a set of amino-substituted nitrogen heterocyclic urea derivatives. Two novel approaches were applied: (1 the simplified molecular input-line entry systems (SMILES based optimal descriptors approach; and (2 the fragment-based simplex representation of molecular structure (SiRMS approach. Comparison with the classic scheme of building up the model and balance of correlation (BC for optimal descriptors approach shows that the BC scheme provides more robust predictions than the classic scheme for the considered pIC50 of the heterocyclic urea derivatives. Comparison of the SMILES-based optimal descriptors and SiRMS approaches has confirmed good performance of both techniques in prediction of kinase insert domain containing receptor (KDR inhibitory activity, expressed as a logarithm of inhibitory concentration (pIC50 of studied compounds.

Carbon-14 labelled nitrogen heterocycles; the syntheses of three phosphodiesterase inhibitors

International Nuclear Information System (INIS)

Lawrie, K.W.M.; Novelli, C.E.A.; Saunders, David

1995-01-01

The syntheses of three heterocyclic phosphodiesterase inhibitors are described from a common radiolabelled precursor, namely 2-propoxybenzo[cyano- 14 C] nitrile. Conversion of the nitrile to the corresponding methyl ketone or amidine allows elaboration of the heterocycles radiolabelled within the ring systems. (Author)

Ozonation of azo dyes (Orange II and Acid Red 27) in saline media

International Nuclear Information System (INIS)

Silva, Alessandra C.; Pic, Jean Stephane; Sant'Anna, Geraldo L.; Dezotti, Marcia

2009-01-01

Ozonation of two azo dyes was investigated in a monitored bench scale bubble column reactor (8.5-L), varying liquid media salt content (0, 1, 40 and 100 g L -1 , NaCl). In experiments with Orange II pH was varied (5, 7.5 and 9) but ozonation of Acid Red 27 was performed at pH 7.5. Ozone self-decomposition rate-constant increased with salt concentration. Color removal was very effective and fast achieved under all experimental conditions. For the two azo dyes tested, more than 98% of color intensity was removed in 30-min ozonation assays. However, only partial mineralization of azo dyes (45%-Orange II; 20%-Acid Red 27) was attained in such experiments. The degree of mineralization (TOC removal) was negatively affected by salt concentration. Biodegradation assays conducted by respirometry revealed the inhibitory effect of dye degradation products formed during ozonation.

Methods for the analysis of azo dyes employed in food industry--A review.

Science.gov (United States)

Yamjala, Karthik; Nainar, Meyyanathan Subramania; Ramisetti, Nageswara Rao

2016-02-01

A wide variety of azo dyes are generally added for coloring food products not only to make them visually aesthetic but also to reinstate the original appearance lost during the production process. However, many countries in the world have banned the use of most of the azo dyes in food and their usage is highly regulated by domestic and export food supplies. The regulatory authorities and food analysts adopt highly sensitive and selective analytical methods for monitoring as well as assuring the quality and safety of food products. The present manuscript presents a comprehensive review of various analytical techniques used in the analysis of azo dyes employed in food industries of different parts of the world. A brief description on the use of different extraction methods such as liquid-liquid, solid phase and membrane extraction has also been presented. Copyright © 2015 Elsevier Ltd. All rights reserved.

Microwave-assisted synthesis of bio-active heterocycles in aqueous media

KAUST Repository

Polshettiwar, Vivek

2010-01-01

Synthesis of bio-active heterocycles and fine chemicals in aqueous media are one of the best solutions for the development of green and sustainable protocols. To illustrate the advantages of aqueous MW chemistry in heterocycle synthesis, in this chapter, various synthetic pathways developed in recent years in aqueous reaction media using microwave irradiation are described.

Privileged scaffolds or promiscuous binders: a glance of pyrrolo[2,1-f][1,2,4]triazines and related bridgehead nitrogen heterocycles in medicinal chemistry.

Science.gov (United States)

Song, Yu'ning; Zhan, Peng; Zhang, Qingzhu; Liu, Xinyong

2013-01-01

Pyrrolo[2,1-f][1,2,4]triazine template, a unique bridgehead nitrogen heterocycle, certainly deserves the title of "privileged scaffold" in the drug discovery field because of the versatility and potential to yield derivatives with a wide range of biological activities, such as anti-anaplastic lymphoma kinase (ALK), Janus kinase 2 (JAK2), VEGFR-2, EGFR and/or HER2, Met kinase, p38α mitogen-activated protein (MAP) kinase and insulin-like growth factor receptor (IGF-1R) kinase activities, etc. These different biological properties of pyrrolo[2,1-f][1,2,4]triazine derivatives have motivated new studies in searching for novel derivatives with improved activity and also other applications in pharmaceutical field. However, no systematic review is available in the literature on the pyrrolo[2,1- f][1,2,4]triazine derivatives concerning the design of potent drug-like compounds. Owing to the importance of this heterocyclic system, the present paper is an attempt to the pharmacological activities, structural modifications and the structure-activity relationship (SAR) reported for bridgehead nitrogen heterocycles in the current literature, making an effort to highlight the importance and therapeutic potentials of the pyrrolo[2,1-f][1,2,4]triazine scaffold and its bridgehead nitrogen bioisosters as heterocyclic privileged medicinal scaffolds.

Synthesis and biological evaluation of novel heterocyclic derivatives of combretastatin A-4.

Science.gov (United States)

Nguyen, Thi Thanh Binh; Lomberget, Thierry; Tran, Ngoc Chau; Colomb, Evelyne; Nachtergaele, Lore; Thoret, Sylviane; Dubois, Joëlle; Guillaume, Joren; Abdayem, Rawad; Haftek, Marek; Barret, Roland

2012-12-01

A novel series of combretastatin A-4 heterocyclic analogues was prepared by replacement of the B ring with indole, benzofurane or benzothiophene, attached at the C2 position. These compounds were evaluated for their abilities to inhibit tubulin assembly: derivative cis3b, having a benzothiophene, showed an activity similar to those of colchicine or deoxypodophyllotoxine. The antiproliferative and antimitotic properties of cis3b against keratinocyte cancer cell lines were also evaluated and the intracellular organization of microtubules in the cells after treatment with both stereoisomers of 3b was also determined, using confocal microscopy. Copyright © 2012 Elsevier Ltd. All rights reserved.

Carbon-14 labelled nitrogen heterocycles; the syntheses of three phosphodiesterase inhibitors

Energy Technology Data Exchange (ETDEWEB)

Lawrie, K.W.M.; Novelli, C.E.A.; Saunders, David [SmithKline Beecham Pharmaceuticals Research and Development, Harlow (United Kingdom). Synthetic Isotope Chemistry Dept.; Coates, W.J. [SmithKline Beecham Pharmaceuticals Research and Development, Welwyn (United Kingdom)

1995-09-01

The syntheses of three heterocyclic phosphodiesterase inhibitors are described from a common radiolabelled precursor, namely 2-propoxybenzo[cyano-{sup 14}C] nitrile. Conversion of the nitrile to the corresponding methyl ketone or amidine allows elaboration of the heterocycles radiolabelled within the ring systems. (Author).

Adsorbed States of phosphonate derivatives of N-heterocyclic aromatic compounds, imidazole, thiazole, and pyridine on colloidal silver: comparison with a silver electrode.

Science.gov (United States)

Podstawka, Edyta; Olszewski, Tomasz K; Boduszek, Bogdan; Proniewicz, Leonard M

2009-09-03

Here, we report a systematic surface-enhanced Raman spectroscopy (SERS) study of the structures of phosphonate derivatives of the N-heterocyclic aromatic compounds imidazole (ImMeP ([hydroxy(1H-imidazol-5-yl)methyl]phosphonic acid) and (ImMe)(2)P (bis[hydroxy-(1H-imidazol-4-yl)-methyl]phosphinic acid)), thiazole (BAThMeP (butylaminothiazol-2-yl-methyl)phosphonic acid) and BzAThMeP (benzylaminothiazol-2-yl-methyl)phosphonic acid)), and pyridine ((PyMe)(2)P (bis[(hydroxypyridin-3-yl-methyl)]phosphinic acid)) adsorbed on nanometer-sized colloidal particles. We compared these structures to those on a roughened silver electrode surface to determine the relationship between the adsorption strength and the geometry. For example, we showed that all of these biomolecules interact with the colloidal surface through aromatic rings. However, for BzAThMeP, a preferential interaction between the benzene ring and the colloidal silver surface is observed more so than that between the thiazole ring and this substrate. The PC(OH)C fragment does not take part in the adsorption process, and the phosphonate moiety of ImMeP and (ImMe)(2)P, being removed from the surface, only assists in this process.

Synthesis of a 1-Aryl-2,2-chlorosilyl(phosphasilene Coordinated by an N-Heterocyclic Carbene

Directory of Open Access Journals (Sweden)

Andreas Wolfgang Kyri

2016-09-01

Full Text Available Phosphasilenes, P=Si doubly bonded compounds, have received considerable attention due to their unique physical and chemical properties. We report on the synthesis and structure of a chlorophosphasilene coordinated by an N-heterocyclic carbene (NHC, which has the potential of functionalization at the Si–Cl moiety. Treatment of a silylphosphine, ArPH–SiCl2RSi (Ar = bulky aryl group, RSi = Si(SiMe33 with two equivalents of Im-Me4 (1,3,4,5-tetramethylimidazol-2-ylidene afforded the corresponding NHC-coordinated phosphasilene, ArP=SiClRSi(Im-Me4 as a stable compound. Bonding properties of the P=Si bond coordinated to an NHC will be discussed on the basis of theoretical calculations.

Structure and spectroscopic properties of the dimeric copper(I) N-heterocyclic carbene complex [Cu₂(CNC(t-Bu))₂](PF₆)₂.

Science.gov (United States)

Riener, Korbinian; Pöthig, Alexander; Cokoja, Mirza; Herrmann, Wolfgang A; Kühn, Fritz E

2015-08-01

In recent years, the use of copper N-heterocyclic carbene (NHC) complexes has expanded to fields besides catalysis, namely medicinal chemistry and luminescence applications. In the latter case, multinuclear copper NHC compounds have attracted interest, however, the number of these complexes in the literature is still quite limited. Bis[μ-1,3-bis(3-tert-butylimidazolin-2-yliden-1-yl)pyridine]-1κ(4)C(2),N:N,C(2');2κ(4)C(2),N:N,C(2')-dicopper(I) bis(hexafluoridophosphate), [Cu2(C19H25N5)2](PF6)2, is a dimeric copper(I) complex bridged by two CNC, i.e. bis(N-heterocyclic carbene)pyridine, ligands. Each Cu(I) atom is almost linearly coordinated by two NHC ligands and interactions are observed between the pyridine N atoms and the metal centres, while no cuprophilic interactions were observed. Very strong absorption bands are evident in the UV-Vis spectrum at 236 and 274 nm, and an emission band is observed at 450 nm. The reported complex is a new example of a multinuclear copper NHC complex and a member of a compound class which has only rarely been reported.

Novel approach for heterocyclization: a clean and efficient synthesis and biological evaluation of 4-oxothiazolidines under microwave technique

International Nuclear Information System (INIS)

Desai, Krunal G.; Desai, K.R.

2006-01-01

A new selective method has been developed for rapid synthesis of 2-(aryl)-3-[2-benzoimidazolythio)-acetamidyl]-4-oxothiazolidines 4a-j by the heterocyclization of 2-{(1H-benzemidazol)-ylthio}-N-benzylidene aceto hydrazide 3a-j with HSCH2COOH under microwave irradiation (MWI) is described. The reaction rate and yield is enhanced tremendously under MWI as compared to conventional methods. All the compounds have been screened for their antifungal activity against Candida albicans and Aspergillus niger, antibacterial activity against Escherchia coli and Staphylococcus aureus. In the primary screening, some of the compounds exhibited appreciable activity. The structures of the synthesized compounds 4a-j have been characterized on the basis of their elemental analysis, IR, HNMR and Mass spectral data. (author)

Characterization of Predominant Reductants in an Anaerobic Leachate-Contaminated Aquifer by Nitroaromatic Probe Compounds

DEFF Research Database (Denmark)

Rügge, Kirsten; Hofstetter, Thomas B.; Haderlein, Stefan B.

1998-01-01

The biogeochemical processes controlling the reductive transformation of contaminants in an anaerobic aquifer were inferred from the relative reactivity patterns of redox-sensitive probe compounds. The fate of five nitroaromatic compounds (NACs) was monitored under different redox conditions in a...... results suggest that Fe(ll) associated with ferric iron minerals is a highly reactive reductant in anaerobic aquifers, which may also determine the fate of other classes of reducible contaminants such as halogenated solvents, azo compounds, sulfoxides, chromate, or arsenate....

Role of brown-rot fungi in the bioremoval of azo dyes under different conditions

Directory of Open Access Journals (Sweden)

Naeem Ali

2010-12-01

Full Text Available The present study is vital to the understanding of bioremediation of structurally different azo dyes by some unusual Brown-rot fungi. Bioremoval of each dye (20 mg l-1 was tested in two different culture media under static and shaking conditions by taking inocula from different fungi. Fungal strains showed varying dyes removal abilities, though considerable high in case of Acid Red (AR 151(di-azo as compared to Orange (Or II (mono-azo. With an exception of Aspergillus tereus SA3, all the fungal isolates showed higher removal of dyes in SDB. Under static condition, the maximum decolorizing fungal strains were; Aspergillus flavus SA2 (67% and Alternaria spp. SA4 (57% in AR 151, while Penicillium spp. (34 and 33 % in Orange II, in SDB and STE, respectively. Bioremoval of dyes was considerably increased when experiments were shifted from static to shaking mode. It was specifically increased (% in; AR 151 (255 with Penicillium spp., Or II with A. flavus SA2 (112 and Alternaria spp. (111. The primary mechanism of dyes removal proved to be fungal biosorption. However, reduction of dyes (onto fungal with formation of their products (α. naphthol, sulphalinic acid and aniline furthermore revealed that dyes (specifically azo were actually biodegraded.

Vibrational spectroscopy and structural analysis of complex uranium compounds (review)

International Nuclear Information System (INIS)

Umreiko, D.S.; Nikanovich, M.V.

1985-01-01

The paper reports on the combined application of experimental and theoretical methods of vibrational spectroscopy together with low-temperature luminescence data to determine the characteristic features of the formation and structure of complex systems, not only containing ligands directly coordinated to the CA uranium, but also associated with the extraspherical polyatomic electrically charged particles: organic cations. These include uranyl complexes and heterocyclical amines. Studied here were compounds of tetra-halouranylates with pyridine and its derivates, as well as dipyridyl, quinoline and phenanthroline. Structural schemes are also proposed for other uranyl complexes with protonated heterocyclical amines with a more complicated composition, which correctly reflect their spectroscopic properties

Removal of selected nitrogenous heterocyclic compounds in biologically pretreated coal gasification wastewater (BPCGW) using the catalytic ozonation process combined with the two-stage membrane bioreactor (MBR).

Science.gov (United States)

Zhu, Hao; Han, Yuxing; Ma, Wencheng; Han, Hongjun; Ma, Weiwei

2017-12-01

Three identical anoxic-aerobic membrane bioreactors (MBRs) were operated in parallel for 300 consecutive days for raw (R 1 ), ozonated (R 2 ) and catalytic ozonated (R 3 ) biologically pretreated coal gasification wastewater (BPCGW) treatment. The results demonstrated that catalytic ozonation process (COP) applied asa pretreatment remarkably improved the performance of the unsatisfactory single MBR. The overall removal efficiencies of COD, NH 3 -N and TN in R 3 were 92.7%, 95.6% and 80.6%, respectively. In addition, typical nitrogenous heterocyclic compounds (NHCs) of quinoline, pyridine and indole were completely removed in the integrated process. Moreover, COP could alter sludge properties and reshape microbial community structure, thus delaying the occurrence of membrane fouling. Finally, the total cost for this integrated process was estimated to be lower than that of single MBR. The results of this study suggest that COP is a good option to enhance pollutants removal and alleviate membrane fouling in the MBR for BPCGW treatment. Copyright © 2017 Elsevier Ltd. All rights reserved.

C-H functionalization directed by transformable nitrogen heterocycles: synthesis of ortho-oxygenated arylnaphthalenes from arylphthalazines.

Science.gov (United States)

Rastogi, Shiva K; Medellin, Derek C; Kornienko, Alexander

2014-01-21

Two protocols for oxygenation of aromatic C-H bonds ortho-positioned to the phthalazine ring were developed. The transannulation of the phthalazine ring to a naphthalene moiety by an Inverse Electron Demand Diels-Alder (IEDDA) reaction led to the synthesis of naphtho[2,1-c]chromenes, 1-(ortho-hydroxyaryl)naphthalenes and 6,7-dihydrobenzo[b]naphtho[1,2-d]oxepine. This new strategy based on the utilization of transformable nitrogen heterocycles in C-H functionalization chemistry can be potentially applicable to the synthesis of a broad range of biaryl compounds.

An overview of the synthetic routes to the best selling drugs containing 6-membered heterocycles

Directory of Open Access Journals (Sweden)

Marcus Baumann

2013-10-01

Full Text Available This review which is the second in this series summarises the most common synthetic routes as applied to the preparation of many modern pharmaceutical compounds categorised as containing a six-membered heterocyclic ring. The reported examples are based on the top retailing drug molecules combining synthetic information from both scientific journals and the wider patent literature. It is hoped that this compilation, in combination with the previously published review on five-membered rings, will form a comprehensive foundation and reference source for individuals interested in medicinal, synthetic and preparative chemistry.

New Gold(I) Organometallic Compounds with Biological Activity in Cancer Cells

NARCIS (Netherlands)

Bertrand, Benoit; de Almeida, Andreia; van der Burgt, Evelien P. M.; Picquet, Michel; Citta, Anna; Folda, Alessandra; Rigobello, Maria Pia; Le Gendre, Pierre; Bodio, Ewen; Casini, Angela

N-Heterocyclic carbene gold(I) complexes bearing a fluorescent coumarin ligand were synthesized and characterized by various techniques. The compounds were examined for their antiproliferative effects in normal and tumor cells in vitro; they demonstrated moderate activity and a certain degree of

Biodegradation of azo dyes in cocultures of anaerobic granular sludge with aerobic aromatic amine degrading enrichment cultures

NARCIS (Netherlands)

Tan, N.C.G.; Prenefeta-Boldú, F.X.; Opsteeg, J.L.; Lettinga, G.; Field, J.A.

1999-01-01

A prerequisite for the mineralization (complete biodegradation) of many azo dyes is a combination of reductive and oxidative steps. In this study, the biodegradation of two azo dyes, 4-phenylazophenol (4-PAP) and Mordant Yellow 10 (4-sulfophenylazo-salicylic acid; MY10), was evaluated in batch

Radioprotective properties of some heterocyclic nitrogenous compounds against spectral modifications in hemoglobin of x-irradiated mice; Proprietes radioprotectrices de certains composes heterocycliques azotes sur les modifications spectrales de l'hemoglobine de souris irradiee

Energy Technology Data Exchange (ETDEWEB)

Roushdy, H; Pierotti, T; Polverelli, M [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

1969-07-01

Imidazole and benzimidazole are known for their radioprotective action. In this work, authors have studied the radioprotective action of these compounds on visible and ultra-violet hemoglobin absorption spectra obtained from mice after in vivo X-irradiation. Results compared to those obtained with cysteamine show: 1- a possible pharmacological action of the heterocyclic nitrogenous compounds on the {alpha} and {beta} bands (540 and 580 m{mu}). 2 - a significative variation of the ratio of the optical densities (580/540) after irradiation with hemoglobin of non and radio-protected mice. However, following a real drop of absorption maxima, the twenty-fifth day after irradiation, normal optical densities of each band are found again. A physico-chemical study would be necessary to understand the hemoglobin transformation after irradiation and perhaps, its possible radioprotection. (authors) [French] Les proprietes radioprotectrices de l'imidazole et du benzimidazole etant deja connues, les auteurs ont etudie l'action de ces produits sur les spectres d'absorption de l'hemoglobine dans le visible et le proche ultra-violet apres une irradiation in vivo de souris a dose letale. L'action de ces produits comparee a celle de la cysteamine utilisee dans les memes conditions a permis de constater: 1- l'action pharmacologique probable des heterocycles azotes sur les bandes {alpha} et {beta} situees a 540 et 580 m{mu}; 2 - qu'avec et sans radioprotecteurs, les modifications spectrales se traduisaient par des variations du rapport d'intensite d'absorption existant entre les bandes a 540 et 580 m{mu}. Toutefois, apres une chute des maxima d'absorption, ceux-ci retournent aux valeurs normales le vingt-cinquieme jour apres irradiation. Une etude physicochimique complementaire de l'hemoglobine permettrait de definir la nature exacte du changement apres irradiation et peut-etre son eventuelle radioprotection. (auteurs)

Partitioning-separation of metal ions using heterocyclic ligands

International Nuclear Information System (INIS)

Hudson, M.J.; Drew, M.G.B.; Iveson, P.B.; Russell, M.L.

2001-01-01

Some guidelines are proposed for the effective design of heterocyclic ligands for partitioning because there is no doubt that the correct design of a molecular extractant is required for the effective separation of metal ions such as actinides(III) from lanthanides(III). Heterocyclic ligands with aromatic ring systems have a rich chemistry, which is only now becoming sufficiently well understood in relation to the partitioning process. The synthesis, characterisation and structures of some chosen molecules will be introduced in order to illustrate some important features. For example, the molecule N-carboxy-butyl-2-amino-4,6-di (2-pyridyl)-1,3,5-triazine (BADPTZ), which is an effective solvent extraction reagent for actinides and lanthanides, has been synthesised, characterised and its interaction with lanthanide ions studied. The interesting and important features of this molecule will be compared with those of other heterocyclic molecules such as 2,6-bis(5-butyl-1,2,4-triazole-3-yl) pyridine (DBTZP), which is a candidate molecule for the commercial separation of actinides and lanthanide elements. (author)

Heterocyclic cyclohexanone monocarbonyl analogs of curcumin can inhibit the activity of ATP-binding cassette transporters in cancer multidrug resistance.

Science.gov (United States)

Revalde, Jezrael L; Li, Yan; Hawkins, Bill C; Rosengren, Rhonda J; Paxton, James W

2015-02-01

Curcumin (CUR) is a phytochemical that inhibits the xenobiotic ABC efflux transporters implicated in cancer multidrug resistance (MDR), such as P-glycoprotein (P-gp), breast cancer resistance protein (BCRP) and multidrug resistance-associated proteins 1 and 5 (MRP1 and MRP5). The use of CUR in the clinic however, is complicated by its instability and poor pharmacokinetic profile. Monocarbonyl analogs of CUR (MACs) are compounds without CUR's unstable β-diketone moiety and were reported to have improved stability and in vivo disposition. Whether the MACs can be used as MDR reversal agents is less clear, as the absence of a β-diketone may negatively impact transporter inhibition. In this study, we investigated 23 heterocyclic cyclohexanone MACs for inhibitory effects against P-gp, BCRP, MRP1 and MRP5. Using flow cytometry and resistance reversal assays, we found that many of these compounds inhibited the transport activity of the ABC transporters investigated, often with much greater potency than CUR. Overall the analogs were most effective at inhibiting BCRP and we identified three compounds, A12 (2,6-bis((E)-2,5-dimethoxy-benzylidene)cyclohexanone), A13 (2,6-bis((E)-4-hydroxyl-3-methoxybenzylidene)-cyclohexanone) and B11 (3,5-bis((E)-2-fluoro-4,5-dimethoxybenzylidene)-1-methylpiperidin-4-one), as the most promising BCRP inhibitors. These compounds inhibited BCRP activity in a non-cell line, non-substrate-specific manner. Their inhibition occurred by direct transporter interaction rather than modulating protein or cell surface expression. From these results, we concluded that MACs, such as the heterocyclic cyclohexanone analogs in this study, also have potential as MDR reversal agents and may be superior alternatives to the unstable parent compound, CUR. Copyright © 2014 Elsevier Inc. All rights reserved.

Trypanocidal 1,3-arylene diketone bis(guanylhydrazone)s. Structure-activity relationships among substituted and heterocyclic analogues.

Science.gov (United States)

Ulrich, P; Cerami, A

1984-01-01

Based on the antitrypanosomal activity of 1,3-diacetylbenzene bis(guanylhydrazone) (4) and 2,6-diacetylpyridine bis(guanylhydrazone) (17), a number of substituted and heterocyclic 1,3-arylene diketone bis(guanylhydrazone)s were prepared and tested against Trypanosoma brucei infections in mice. A wide range of ED50 values was observed among 5-substituted derivatives of 4. The 5-amino analogue 5 and 5-acetamido analogue 6 were about twice as active as 4. 1,3,5-Triacetylbenzene tris(guanylhydrazone) (12) was about 9 times as active as 4 and was approximately one-half as active as the currently used trypanocide diminazene aceturate in this test system. Other 5-derivatives had activity equivalent to or less than that of the parent compound 4. Three new heterocyclic analogues were all less active than 2,6-diacetylpyridine derivative 17 and benzene derivative 4. Ring substitution ortho to the guanylhydrazone side chains was invariably detrimental to activity. Side-chain homologues 1,3-dipentanoylbenzene bis(guanylhydrazone) and 1,3-diacetylbenzene bis(2-imidazolin-2-ylhydrazone) were essentially inactive.

Studies on the cytotoxicity and anticancer performance of heterocyclic hypervalent organobismuth(III) compounds.

Science.gov (United States)

Liu, Yong-Ping; Lei, Jian; Tang, Li-Wen; Peng, Yao; Au, Chak-Tong; Chen, Yi; Yin, Shuang-Feng

2017-10-20

Novel organobismuth(III) complex of 5H-dibenzo[c,f][1,5]oxabismocin-12(7H)-yl nitrate (C2) was synthesized and characterized by spectral and elemental analysis. It was compared with other five C,E,C-chelating (E = N, O, S) organobismuth(III) complexes against human adenocarcinoma alveolar basal epithelial cells (A549), human liver cancer cell line (SMCC7721), human gastric cancer cell line (SGC-7901), human colon adenocarcinoma cell line (SW480) and healthy human bronchial cell line (16HBE14o-) in vitro. It was found that C2 exhibited the best anticancer activity. Further mechanistic investigation indicated that toxicological activity of C2 was ascribable to apoptosis rather than anti-proliferative activity. Apoptosis was induced through up-regulating the level of Bcl-2/Bax as well as the activation of caspase-3. The results demonstrate that heterocyclic organobismuth(III) complexes of this type have great potential in the treatment of cancer. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Key intermediates in nitrogen transformation during microwave pyrolysis of sewage sludge: a protein model compound study.

Science.gov (United States)

Zhang, Jun; Tian, Yu; Cui, Yanni; Zuo, Wei; Tan, Tao

2013-03-01

The nitrogen transformations with attention to NH3 and HCN were investigated at temperatures of 300-800°C during microwave pyrolysis of a protein model compound. The evolution of nitrogenated compounds in the char, tar and gas products were conducted. The amine-N, heterocyclic-N and nitrile-N compounds were identified as three important intermediates during the pyrolysis. NH3 and HCN were formed with comparable activation energies competed to consume the same reactive substances at temperatures of 300-800°C. The deamination and dehydrogenation of amine-N compounds from protein cracking contributed to the formation of NH3 (about 8.9% of Soy-N) and HCN (6.6%) from 300 to 500°C. The cracking of nitrile-N and heterocyclic-N compounds from the dehydrogenation and polymerization of amine-N generated HCN (13.4%) and NH3 (31.3%) between 500 and 800°C. It might be able to reduce the HCN and NH3 emissions through controlling the intermediates production at temperatures of 500-800°C. Copyright © 2013 Elsevier Ltd. All rights reserved.

Synthesis of some Heterocyclic Compounds Derived from 2-Chloro-N-p-Tolylacetamide

Directory of Open Access Journals (Sweden)

Hanan Gh Shaaban

2017-02-01

Full Text Available This research includes preparation of (2-chloro-N-p-tolylacetamide (1 from the reaction of (p-aminotoluene with chloro acetyl chloride. Compound (1 reacted with thiosemi carbazide and gave compound (2, and when compound (1 reacted with semicarbazide gave compound (3. While when compound (1 reacted with thiourea it produced compound (4. Compounds (2-4 when reacted with appropriate aromatic aldehydes or ketones produced Shiff bass (5-16, which in turn reacted with chloro acetyl chloride in the present of tri ethyl amine and dioxin gave β-lactam derivatives (14-22. The structures of these compounds were characterized from their melting points, FT-IR, and NMR.

Highly selective deuteration of pharmaceutically relevant nitrogen-containing heterocycles: a flow chemistry approach.

Science.gov (United States)

Ötvös, Sándor B; Mándity, István M; Fülöp, Ferenc

2011-08-01

A simple and efficient flow-based technique is reported for the catalytic deuteration of several model nitrogen-containing heterocyclic compounds which are important building blocks of pharmacologically active materials. A continuous flow reactor was used in combination with on-demand pressure-controlled electrolytic D(2) production. The D(2) source was D(2)O, the consumption of which was very low. The experimental set-up allows the fine-tuning of pressure, temperature, and flow rate so as to determine the optimal conditions for the deuteration reactions. The described procedure lacks most of the drawbacks of the conventional batch deuteration techniques, and additionally is highly selective and reproducible.

Thermal stability and degradation behavior of novel wholly aromatic azo polyamide-hydrazides

International Nuclear Information System (INIS)

Al-Ghamdia, R.F.; Fahmib, M.M.; Mohamed, N.A.

2005-01-01

Thermal stability and degradation behavior of a series of novel wholly aromatic azo polyamide-hydrazides have been investigated in nitrogen and in air atmospheres using differential scanning ealorimetry, thermogravimetry, infrared spectroscopy and elemental analysis. The influences of controlled structural variations and molecular weight on the thermal stability and degradation behavior of this series of polymers have also been studied. The structural differences were achieved by varying the content of para- and meta substituted phenylene rings incorporated within this series. The polymers were prepared by a low temperature solution polycondensation reaction of p aminosalicylic acid hydrazide and an equimolar amount of 4,4-azo dibenzoyl chloride [4,4 ADBC] or 3,3-azo dibenzoyl chloride [3,3ADBC] or mixtures of various molar ratios of 4,4ADBC and 3,3ADBC in anhydrous N,N- dimethyl acetamide [DMAc] containing lithium chloride as a solvent at -10 degree C. The results clearly reveal that these polymers are characterized by high thermal stability. Their weight loss occurred in three distinctive steps. The first was small and assigned to the evaporation of absorbed moisture. The second was appreciable and was attributed to the cyclo dehydration reaction of the hydrazide groups into 1,3,4-oxadiazole rings by losing water, combined with elimination of azo groups by losing molecular nitrogen. This is not a true degradation but rather a thermo-chemical transformation reaction of the azo polyamide-hydrasdes into the corresponding polyamide-l,3,4-oxadiazoles. The third was relatively severe and sharp, particularly in air, and corresponded to the decomposition of the resulting polyamide-l, 3,4-oxadiazoles. In both degradation atmospheres, the improved resistance to high temperatures was always associated with increased content of para- phenylene moieties of the investigated polymer. Further, with exception of 160-200 degree C temperature range, where the lower molecular weight

Synthesis of novel 2-mercapto benzothiazole and 1,2,3-triazole based bis-heterocycles: their anti-inflammatory and anti-nociceptive activities.

Science.gov (United States)

Shafi, Syed; Alam, Mohammad Mahboob; Mulakayala, Naveen; Mulakayala, Chaitanya; Vanaja, G; Kalle, Arunasree M; Pallu, Reddanna; Alam, M S

2012-03-01

A focused library of novel bis-heterocycles encompassing 2-mercapto benzothiazole and 1,2,3-triazoles were synthesized using click chemistry approach. The synthesized compounds have been tested for their anti-inflammatory activity by using biochemical cyclooxygenase (COX) activity assays and carrageenan-induced hind paw edema. Among the tested compounds, compound 4d demonstrated a potent selective COX-2 inhibition with COX-2/COX-1 ratio of 0.44. Results from carrageenan-induced hind paw edema showed that compounds 4a, 4d, 4e and 4f posses significant anti-inflammatory activity as compared to the standard drug Ibuprofen. The compounds showing significant activity were further subjected to anti-nociceptive activity by writhing test. These four compounds have shown comparable activity with the standard Ibuprofen. Further ulcerogenic studies shows that none of these compounds causing gastric ulceration. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

Mixed ligand complexes of uranyl lactate with some simple and heterocyclic amines

International Nuclear Information System (INIS)

Jaiswal, S.R.; Rupainwar, D.C.

1984-01-01

Mixed ligand complexes of uranyl lactate with simple and heterocyclic amines having a general formula UO 2 (C 3 H 5 O 3 ).nL.xH 2 O, were prepared, where n=1 and x=1 for L=ethylenediamine (En), dimethyl aniline (DMAn), diethyl amine (DEA), orthophenylenediamine (OPDA), pyridine (Py), 2-picoline(2-Pic), 3-picoline(3-Pic), 4-Picoline(4-Pic), piperidine (Pipy), 2,4-lutidine (2,4 Lut), 2-Aminopyridine (2 APy), quinoline (Quin), isoquinoline (Isoquin) but x=0 for the ligands 2,2'-bipyrldyl (Bipy) and 1,10-phenenthroline (Phen). All the compounds are bright yellow coloured with high decomposition temp. (>200deg) and were characterized by electronic and infrared spectral data. (author)

Anticancer Gold N-Heterocyclic Carbene Complexes: A Comparative in vitro and ex vivo Study.

Science.gov (United States)

Estrada-Ortiz, Natalia; Guarra, Federica; de Graaf, Inge A M; Marchetti, Lorella; de Jager, Marina H; Groothuis, Geny M M; Gabbiani, Chiara; Casini, Angela

2017-09-07

A series of organometallic Au I N-heterocyclic carbene (NHC) complexes was synthesized and characterized for anticancer activity in four human cancer cell lines. The compounds' toxicity in healthy tissue was determined using precision-cut kidney slices (PCKS) as a tool to determine the potential selectivity of the gold complexes ex vivo. All evaluated compounds presented cytotoxic activity toward the cancer cells in the nano- or low micromolar range. The mixed Au I NHC complex, (tert-butylethynyl)-1,3-bis-(2,6-diisopropylphenyl)imidazol-2-ylidene gold(I), bearing an alkynyl moiety as ancillary ligand, showed high cytotoxicity in cancer cells in vitro, while being barely toxic in healthy rat kidney tissues. The obtained results open new perspectives toward the design of mixed NHC-alkynyl gold complexes for cancer therapy. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Synthesis and characterization of near-IR absorbing metal-free and zinc(II phthalocyanines modified with aromatic azo groups

Directory of Open Access Journals (Sweden)

Mukaddes Özçeşmeci

2015-05-01

Full Text Available Metal-free and zinc(II phthalocyanine complexes bearing peripheral (E-4-((2-hydroxynaphthalen-1-yldiazenyl units have been synthesized. Novel phthalonitrile derivative required for the preparation of phthalocyanine complexes was prepared by coupling 4-aminophthalonitrile and 2-naphthol. The structures of these new compounds were characterized by using elemental analyses, proton nuclear magnetic resonance, fourier transform infrared spectroscopy, ultraviolet–visible spectroscopy, fluorescence spectroscopy and mass spectrometry. In the UV-Vis spectra a broad absorption band appears for phthalocyanine complexes at around 450–500 nm resulting from azo-group introduced onto the phthalocyanine ring. The photophysical properties of metal-free and zinc(II phthalocyanines were studied in tetrahydrofuran.

Synthesis and anticancer activity of silver(I)-N-heterocyclic carbene complexes derived from the natural xanthine products caffeine, theophylline and theobromine.

Science.gov (United States)

Mohamed, Heba A; Lake, Benjamin R M; Laing, Thomas; Phillips, Roger M; Willans, Charlotte E

2015-04-28

A new library of silver(I)-N-heterocyclic carbene complexes prepared from the natural products caffeine, theophylline and theobromine is reported. The complexes have been fully characterised using a combination of NMR spectroscopy, mass spectrometry, elemental analysis and X-ray diffraction analysis. Furthermore, the hydrophobicity of the complexes has been measured. The silver(I)-N-heterocyclic carbenes have been evaluated for their antiproliferative properties against a range of cancer cell lines of different histological types, and compared to cisplatin. The data shows different profiles of response when compared to cisplatin in the same panel of cells, indicating a different mechanism of action. Furthermore, it appears that the steric effect of the ligand and the hydrophobicity of the complex both play a role in the chemosensitivity of these compounds, with greater steric bulk and greater hydrophilicity delivering higher cytotoxicity.

Metal and hydrogen catalysis in isotopic hydrogen exchange in some biologically important heterocyclic compounds

International Nuclear Information System (INIS)

Buncel, E.; Joly, H.A.; Jones, J.R.; Onyido, I.

1989-01-01

This study reports on the catalytic roles of metal and hydrogen ions in tritium exchange in some heterocyclic substrates which occur as residues in many biologically important molecules. We have found that detritiation of 1-methyl[2- 3 H]imidazole is inhibited by a number of metal ions. As well, inhibition of exchange rates was noted with Ag(I) and Cu(II) for [2- 3 H]thiazole and 1-methyl[8- 3 H]inosine, with Ag(I) for [2- 3 H]benzothiazole, and with Cu(II) for 1-methyl[8- 3 H]guanosine. A complete mechanistic description, which includes the various metal ion-coordinated species generated under the experimental conditions, is presented. The results demonstrate the reactivity order: protonated >> metal-coordinated >> neutral substrates. The differential catalytic effects of metal and hydrogen ions in these processes are discussed in terms of the extent of charge developed on the ligating heteroatom in the reaction intermediate. (author). 13 refs.; 1 fig

Discovery of Novel Tricyclic Heterocycles as Potent and Selective DPP-4 Inhibitors for the Treatment of Type 2 Diabetes

Energy Technology Data Exchange (ETDEWEB)

Wu, Wen-Lian; Hao, Jinsong; Domalski, Martin; Burnett, Duane A.; Pissarnitski, Dmitri; Zhao, Zhiqiang; Stamford, Andrew; Scapin, Giovanna; Gao, Ying-Duo; Soriano, Aileen; Kelly, Terri M.; Yao, Zuliang; Powles, Mary Ann; Chen, Shiying; Mei, Hong; Hwa, Joyce (Merck)

2016-05-12

In our efforts to develop second generation DPP-4 inhibitors, we endeavored to identify distinct structures with long-acting (once weekly) potential. Taking advantage of X-ray cocrystal structures of sitagliptin and other DPP-4 inhibitors, such as alogliptin and linagliptin bound to DPP-4, and aided by molecular modeling, we designed several series of heterocyclic compounds as initial targets. During their synthesis, an unexpected chemical transformation provided a novel tricyclic scaffold that was beyond our original design. Capitalizing on this serendipitous discovery, we have elaborated this scaffold into a very potent and selective DPP-4 inhibitor lead series, as highlighted by compound 17c.

Comparison study of transparent RF-sputtered ITO/AZO and ITO/ZnO bilayers for near UV-OLED applications

Science.gov (United States)

Rezaie, Mahdiyar Nouri; Manavizadeh, Negin; Abadi, Ehsan Mohammadi Nasr; Nadimi, Ebrahim; Boroumand, Farhad Akbari

2017-01-01

Hybrid inorganic/organic light-emitting diodes have attracted much attention in the field of luminescent electronics due to the desired incorporation of high optoelectronic features of inorganic materials with the processability and variety of organic polymers. To generate and emit a near ultraviolet (N-UV) ray, wide band gap semiconductors can be applied in the organic light-emitting diodes (OLEDs). In this paper, zinc oxide (ZnO) and aluminum-doped ZnO (AZO) thin films are deposited by radio frequency (RF) sputtering above the ITO electrode and poly [2-methoxy-5-(2-ethyl-hexyloxy)-1,4-phenylene-vinylene] (MEH-PPV) conjugated polymer is utilized as a complementary p-type semiconductor in OLED structure. The impact of ZnO and AZO thickness on the structural, electrical, optical and morphological properties of ITO/AZO and ITO/ZnO bilayers are scrutinized and compared. Results show that with the enlargement of both ZnO and AZO film thickness, the physical properties are gradually improved resulting in the better quality of transparent conducting thin film. The average electrical resistivity of 8.4 × 10-4 and 1.1 × 10-3 Ω-cm, average sheet resistance of 32.9 and 42.3 Ω/sq, average transmittance of 88.3 and 87.3% and average FOM of 1.0 × 104 and 7.4 × 103 (Ω-cm)-1 are obtained for ITO/AZO and ITO/ZnO bilayers, respectively. Moreover, comparing the results indicates that the strain and the stress within the ITO/AZO bilayer are decreased nearly 19% with respect to ITO/ZnO bilayer which yield higher quality of crystal. Consequently, the physical properties of ITO/AZO bilayer is found to be superior regarding ITO/ZnO bilayer. For fabricated UV-OLEDs, the turn-on voltages, the characteristic energy (Et) and the total concentration of traps (Nt) for the devices with the structures of ITO/ZnO/MEH-PPV/Al and ITO/AZO/MEH-PPV/Al are obtained 12 and 14 V, 0.108 and 0.191 eV, 9.33 × 1016 and 5.22 × 1016 cm-3, respectively. Furthermore, according to the electroluminescence

Microwave-Assisted Multicomponent Synthesis of Heterocycles

NARCIS (Netherlands)

Kruithof, A.; Ruijter, E.; Orru, R.V.A.

2011-01-01

Multicomponent reactions are valuable tools for the generation of diverse heterocycles. As in many fields or organic chemistry, microwave irradiation is rapidly replacing conventional heating methods in multicomponent chemistry. In this review, we present an overview of recent applications of the

Structure-activity relationship (SAR) study and design strategies of nitrogen-containing heterocyclic moieties for their anticancer activities.

Science.gov (United States)

Akhtar, Jawaid; Khan, Ahsan Ahmed; Ali, Zulphikar; Haider, Rafi; Shahar Yar, M

2017-01-05

The present review article offers a detailed account of the design strategies employed for the synthesis of nitrogen-containing anticancer agents. The results of different studies describe the N-heterocyclic ring system is a core structure in many synthetic compounds exhibiting a broad range of biological activities. Benzimidazole, benzothiazole, indole, acridine, oxadiazole, imidazole, isoxazole, pyrazole, triazoles, quinolines and quinazolines including others drugs containing pyridazine, pyridine and pyrimidines are covered. The following studies of these compounds suggested that these compounds showed their antitumor activities through multiple mechanisms including inhibiting protein kinase (CDK, MK-2, PLK1, kinesin-like protein Eg5 and IKK), topoisomerase I and II, microtubule inhibition, and many others. Our concise representation exploits the design and anticancer potency of these compounds. The direct comparison of anticancer activities with the standard enables a systematic analysis of the structure-activity relationship among the series. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Anti-trypanosomal activity of cationic N-heterocyclic carbene gold(I) complexes.

Science.gov (United States)

Winter, Isabel; Lockhauserbäumer, Julia; Lallinger-Kube, Gertrud; Schobert, Rainer; Ersfeld, Klaus; Biersack, Bernhard

2017-06-01

Two gold(I) N-heterocyclic carbene complexes 1a and 1b were tested for their anti-trypanosomal activity against Trypanosoma brucei parasites. Both gold compounds exhibited excellent anti-trypanosomal activity (IC 50 =0.9-3.0nM). The effects of the gold complexes 1a and 1b on the T. b. brucei cytoskeleton were evaluated. Rapid detachment of the flagellum from the cell body occurred after treatment with the gold complexes. In addition, a quick and complete degeneration of the parasitic cytoskeleton was induced by the gold complexes, only the microtubules of the detached flagellum remained intact. Both gold compounds 1a and 1b feature selective anti-trypanosomal agents and were distinctly more active against T. b. brucei cells than against human HeLa cells. Thus, the gold complexes 1a and 1b feature promising drug candidates for the treatment of trypanosome infections such as sleeping sickness (human African Trypanosomiasis caused by Trypanosoma brucei parasites). Copyright © 2017 Elsevier B.V. All rights reserved.

Low-temperature-fabricated ZnO, AZO, and SnO{sub 2} nanoparticle-based dye-sensitized solar cells

Energy Technology Data Exchange (ETDEWEB)

Kim, Hong Hee; Park, Cheolmin; Choi, Wonkook; Cho, Sungjae; Moon, Byungjoon; Son, Dongick [Korea Institute of Science and Technology, Seoul (Korea, Republic of); Yonsei University, Seoul (Korea, Republic of)

2014-11-15

The authors investigated the microstructural and the electrical properties of ZnO, AZO, and SnO{sub 2} based dye-sensitized solar cells (DSSCs) fabricated using a low-temperature-processed (200 .deg. C) dyesensitized ZnO, AZO, and SnO{sub 2} nanoparticle thin film and a Pt catalyst deposited on ITO/glass by RF magnetron sputtering. A hydropolymer containing PEG (poly ethylene glycol) and PEO (poly ethylene oxide) is used to make uniformly-distributed ZnO, AZO, and SnO{sub 2} nanoparticle layer which forms a nano porous ZnO, AZO, and SnO{sub 2} network after heat treatment. The layer is then dye sensitized and sandwiched between two electrodes in an electrolyte to make a DSSC device. The highest measured parameters, the short-circuit current density (J{sub sc}), the open circuit potential (V{sub oc}), the fill factor (FF), and power conversion efficiency (η), of the DSSC fabricated wander optimized conditions were observed to be 5.10 mA/cm{sup 2}, 0.61 V, 0.46, and 1.43%, respectively.

Dietary exposure to heterocyclic amines in high-temperature cooked meat and fish in Malaysia.

Science.gov (United States)

Jahurul, M H A; Jinap, S; Ang, S J; Abdul-Hamid, A; Hajeb, P; Lioe, H N; Zaidul, I S M

2010-08-01

The intake of heterocyclic amines is influenced by the amount and type of meat and fish ingested, frequency of consumption, cooking methods, cooking temperature, and duration of cooking. In this study, the dietary intake of heterocyclic amines in Malaysia and their main sources were investigated. Forty-two samples of meat and fish were analysed by high-performance liquid chromatography with photodiode array detector to determine the concentration of the six predominant heterocyclic amines, namely: 2-amino-3-methylimidazo[4,5-f] quinoline (IQ), 2-amino-3,4-dimethylimidazo[4,5-f] quinoline(MeIQ), 2-amino-3,8-dimethylimidazo[4,5-f] quinoxaline (MeIQx), 2-amino-3,4,8-trimethylimidazo[4,5-f] quinoxaline (4,8-DiMeIQx), 2-amino-3,7,8-trimethylimidazo[4,5-f] quinoxaline (7,8-DiMeIQx), and 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP). Dietary intake data were obtained using a food-frequency questionnaire when interviewing 600 Malaysian respondents. The level of total heterocyclic amines in food samples studies ranged from not detected to 38.7 ng g(-1). The average daily intake level of heterocyclic amine was 553.7 ng per capita day(-1). The intake of PhIP was the highest, followed by MeIQx and MeIQ. The results reveal that fried and grilled chicken were the major dietary source of heterocyclic amines in Malaysia. However, the heterocyclic amine intake by the Malaysian population was lower than those reported from other regions.

A novel heterocyclic compound improves working memory in the radial arm maze and modulates the dopamine receptor D1R in frontal cortex of the Sprague-Dawley rat.

Science.gov (United States)

Hussein, Ahmed M; Aher, Yogesh D; Kalaba, Predrag; Aher, Nilima Y; Dragačević, Vladimir; Radoman, Bojana; Ilić, Marija; Leban, Johann; Beryozkina, Tetyana; Ahmed, Abdel Baset M A; Urban, Ernst; Langer, Thierry; Lubec, Gert

2017-08-14

A series of compounds have been shown to enhance cognitive function via the dopaminergic system and indeed the search for more active and less toxic compounds is continuing. It was therefore the aim of the study to synthetise and test a novel heterocyclic compound for cognitive enhancement in a paradigm for working memory. Specific and effective dopamine re-uptake inhibition DAT (IC50=4,1±0,8μM) made us test this compound in a radial arm maze (RAM) in the rat. CE-125 (4-((benzhydrylsulfinyl)methyl)-2-cyclopropylthiazole), was tested for dopamine (DAT), serotonin and norepinephrine re-uptake inhibition by a well-established system. The working memory index (WMI) was evaluated in male Sprague Dawley rats that were intraperitoneally injected with CE-125 (1 or 10mg/kg body weight). In order to evaluate basic neurotoxicity, the open field, elevated plus maze, rota rod studies and the forced swim test were carried out. Frontal cortex was taken at the last day of the RAM test and dopamine receptors D1R and D2R, DAT and phosphorylated DAT protein levels were determined. On the 10th day both doses were increasing the WMI as compared to the vehicle-treated group. In both, trained and treated groups, D1R levels were significantly reduced while D2R levels were unchanged. DAT levels were comparable between all groups while phosphorylated DAT levels were increased in the trained group treated with 1mg/kg body weight. CE-125 as a probably non-neurotoxic compound and specific reuptake inhibitor was shown to increase performance (WMI) and modulation of the dopaminergic system is proposed as a possible mechanism of action. Copyright © 2017. Published by Elsevier B.V.

Mechanism of azo dye degradation in Advanced Oxidation Processes: Degradation of Sulfanilic Acid Azochromotrop and its parent compounds in aqueous solution by ionizing radiation

International Nuclear Information System (INIS)

Palfi, Tamas; Wojnarovits, Laszlo; Takacs, Erzsebet

2011-01-01

Mechanistic studies were made on hydroxyl radical and hydrated electron reaction with Sulfanilic Acid Azochromotrop (SPADNS) as model azo dye in dilute aqueous solution. SPADNS contains 4,5-dihydroxynaphthalene-2,7-disulfonic acid part and 4-sulfophenylazo group. To establish the details of the reaction mechanism the reactions of two simpler molecules without 4-sulfophenylazo part were also studied: one of them contained one (in position 4, II), the other two (in positions 4 and 5, III) -OH groups. Hydroxyl radicals react with these molecules with radical addition to the naphthalene-2,7-disulfonic acid part. The adduct hydroxycyclohexadienyl type radical decays in radical-radical reactions, or undergoes a (pH dependent) water elimination to yield naphthoxy radical. The radical decay takes place on the ms timescale. Degradation efficiencies are 0.6-0.8. Hydrated electron in the case of the two simpler molecules reacts with the rings, while in the case of dye with the azo bond. Electron scavenging is followed by protonation, this reaction in the case of II and III yields cyclohexadienyl, while with the dye hydrazo radical. The efficiency of degradation with II and III is 0.2-0.6, while for SPADNS it is close to 1.

Oxidative N-Heterocyclic Carbene-Catalyzed γ-Carbon Addition of Enals to Imines: Mechanistic Studies and Access to Antimicrobial Compounds.

Science.gov (United States)

Zheng, Peng-Cheng; Cheng, Jiajia; Su, Shihu; Jin, Zhichao; Wang, Yu-Huang; Yang, Song; Jin, Lin-Hong; Song, Bao-An; Chi, Yonggui Robin

2015-07-06

The reaction mechanism of the γ-carbon addition of enal to imine under oxidative N-heterocyclic carbene catalysis is studied experimentally. The oxidation, γ-carbon deprotonation, and nucleophilic addition of γ-carbon to imine were found to be facile steps. The results of our study also provide highly enantioselective access to tricyclic sulfonyl amides that exhibit interesting antimicrobial activities against X. oryzae, a bacterium that causes bacterial disease in rice growing. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Decolorization of azo dye and generation of electricity by microbial fuel cell with laccase-producing white-rot fungus on cathode

International Nuclear Information System (INIS)

Lai, Chi-Yung; Wu, Chih-Hung; Meng, Chui-Ting; Lin, Chi-Wen

2017-01-01

Highlights: • A laccase-producing fungus on cathode of MFC was used to enhance degradation of azo dye. • Laccase-producing fungal cathodes performed better than laccase-free control cathodes. • A maximum power density of 13.38 mW/m"2 and an >90% decolorization of acid orange 7 were obtained. • Growing a fungal culture with continuous laccase production improved MFC’s electricity generation. - Abstract: Wood-degrading white-rot fungi produce many extracellular enzymes, including the multi-copper oxidative enzyme laccase (EC 1.10.3.2). Laccase uses atmospheric oxygen as the electron acceptor to catalyze a one-electron oxidation reaction of phenolic compounds and therefore has the potential to simultaneously act as a cathode catalyst in a microbial fuel cell (MFC) and degrade azo dye pollutants. In this study, the laccase-producing white-rot fungus Ganoderma lucidum BCRC 36123 was planted on the cathode surface of a single-chamber MFC to degrade the azo dye acid orange 7 (AO7) synergistically with an anaerobic microbial community in the anode chamber. In a batch culture, the fungus used AO7 as the sole carbon source and produced laccase continuously, reaching a maximum activity of 20.3 ± 0.3 U/L on day 19 with a 77% decolorization of the dye (50 mg/L). During MFC operations, AO7 in the anolyte diffused across a layer of polyvinyl alcohol-hydrogel that separated the cathode membrane from the anode chamber, and served as a carbon source to support the growth of, and production of laccase by, the fungal mycelium that was planted on the cathode. In such MFCs, laccase-producing fungal cathodes outperformed laccase-free controls, yielding a maximum open-circuit voltage of 821 mV, a closed-circuit voltage of 394 mV with an external resistance of 1000 Ω, a maximum power density of 13.38 mW/m"2, a maximum current density of 33 mA/m"2, and a >90% decolorization of AO7. This study demonstrates the feasibility of growing a white-rot fungal culture with continuous

Inorganic heterocycles with two manganes or rhenium carbonyl units

International Nuclear Information System (INIS)

Kuellmer, V.; Vahrenkamp, H.

1977-01-01

From the reactive complexes [(CO) 4 M-E-Sn(CH 3 ) 3 ] 2 (M = Mn,Re; E = S,Se) with (CH 3 ) 2 PCl via the non-isolable four-membered ring intermediates [(CO) 4 M-E-P(CH 3 ) 2 ] 2 the six-membered heterocycles[-(CO) 4 M-P(CH 3 ) 2 -E-] 2 are formed. By use of (CH 3 ) 2 AsCl both the four-membered ring intermediates and the six-membered ring products can be isolated. The six-membered heterocycles can be opened by trimethylphosphine. (orig./HK) [de

Structural, optical and nonlinear optical studies of AZO thin film prepared by SILAR method for electro-optic applications

Science.gov (United States)

Edison, D. Joseph; Nirmala, W.; Kumar, K. Deva Arun; Valanarasu, S.; Ganesh, V.; Shkir, Mohd.; AlFaify, S.

2017-10-01

Aluminium doped (i.e. 3 at%) zinc oxide (AZO) thin films were prepared by simple successive ionic layer adsorption and reaction (SILAR) method with different dipping cycles. The structural and surface morphology of AZO thin films were studied by using X-ray diffraction (XRD) and scanning electron microscopy (SEM). The optical parameters such as, transmittance, band gap, refractive index, extinction coefficient, dielectric constant and nonlinear optical properties of AZO films were investigated. XRD pattern revealed the formation of hexagonal phase ZnO and the intensity of the film was found to increase with increasing dipping cycle. The crystallite size was found to be in the range of 29-37 nm. Scanning Electron Microscope (SEM) images show the presence of small sized grains, revealing that the smoothest surface was obtained at all the films. The EDAX spectrum of AZO conforms the presence of Zn, O and Al. The optical transmittance in the visible region is high 87% and the band gap value is 3.23 eV. The optical transmittance is decreased with respect to dipping cycles. The room temperature PL studies revealed that the AZO films prepared at (30 cycles) has good film quality with lesser defect density. The third order nonlinear optical parameters were also studied using Z-scan technique to know the applications of deposited films in nonlinear devices. The third order nonlinear susceptibility value is found to be 1.69 × 10-7, 3.34 × 10-8, 1.33 × 10-7and 2.52 × 10-7 for AZO films deposited after 15, 20, 25 and 30 dipping cycles.

Synthesis of heterocyclic chalcone derivatives and their radical scavenging ability toward 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radicals

International Nuclear Information System (INIS)

Hwang, Kijun; Kim, Hoseok; Kim, Beomtae; Han, Incheol

2012-01-01

A series of heterocyclic chalcone derivatives bearing heterocycles such as thiophene or furan ring as an isostere of benzene ring were carefully prepared, and the influence of heterocycles on 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activities was systematically investigated. Structure-activity relationships (SAR) analysis showed that the activities of thiophene ring-containing chalcones were higher than those of furan ring containing chalcones, and the presence of methyl substituent of heterocyclic ring distinctly affected the activities compared with non-substituted heterocycles in an opposite manner, with the 4'-methyl group of thiophene ring increasing activity and the 3'-methyl group of the furan ring decreasing activity. The distinct isosteric effect of heterocycles (i.e., thiophene or furan ring) on radical scavenging activities of heterocyclic chalcones was distinctly demonstrated in our work

Pyrolysis mechanism of microalgae Nannochloropsis sp. based on model compounds and their interaction

International Nuclear Information System (INIS)

Wang, Xin; Tang, Xiaohan; Yang, Xiaoyi

2017-01-01

Highlights: • Pyrolysis experiments were conducted by model compounds of algal components. • Interaction affected little bio-crude yield of model compounds co-pyrolysis. • Some interaction pathways between microalgae components were recommended. • N-heterocyclic compounds were further pyrolysis products of Maillard reaction products. • Surfactant synthesis (lipid-amino acids and lipid-glucose) between algal components. - Abstract: Pyrolysis is one of important pathways to convert microalgae to liquid biofuels and key components of microalgae have different chemical composition and structure, which provides a barrier for large-scale microalgae-based liquid biofuel application. Microalgae component pyrolysis mechanism should be researched to optimal pyrolysis process parameters. In this study, single pyrolysis and co-pyrolysis of microalgal components (model compounds castor oil, soybean protein and glucose) were conducted to reveal interaction between them by thermogrametric analysis and bio-crude evaluation. Castor oil (model compound of lipid) has higher pyrolysis temperature than other model compounds and has the maximum contribution to bio-crude formation. Bio-crude from soybean protein has higher N-heterocyclic compounds as well as phenols, which could be important aromatic hydrocarbon source during biorefineries and alternative aviation biofuel production. Potential interaction pathways based on model compounds are recommended including further decomposition of Maillard reaction products (MRPs) and surfactant synthesis, which indicate that glucose played an important role on pyrolysis of microalgal protein and lipid components. The results should provide necessary information for microalgae pyrolysis process optimization and large-scale pyrolysis reactor design.

Influence of mass transfer and chemical reaction on ozonation of azo dyes

Energy Technology Data Exchange (ETDEWEB)

Choi, I.S.; Wiesmann, U. [Dept. of Environmental Engineering, Technical Univ. of Berlin, Berlin (Germany)

2003-07-01

Azo dyes can be only mineralised by chemical oxidation. In this paper the oxidation of reactive black 5 (RB 5) and reactive orange 96 (RO 96) with concentrations between 35 and 5700 mgL{sup -1} (RB 5) and between 20 and 2050 mgL{sup -1} (RO 96) is investigated. A lab scale bubble column was used, which was gassed by a mixture of O{sub 2} and O{sub 3}. The oxidation rate was influenced by mass transfer for all dye concentrations used. For lower dye concentrations mass transfer alone was decisive for reaction rate showing an enhancement factor of E {approx} 1. However, in the region of higher dye concentrations, the slope of the decreasing ozone concentration inside the liquid boundary layer increases more and more with increasing dye concentration as a result of a chemical oxidation. Therefore, the enhancement factor depends on the kind and concentration of the azo dyes. For RB 5 as an diazo dye an enhancement factor of E = 9 was observed for 3800 mgL{sup -1}, RO 96 as a mono azo dye with a remarkable higher chemical oxidation rate shows an E = 17 already for 2050 mgL{sup -1}. (orig.)

Electrochemical characterization of azo dye (E)-1-(4-((4-(phenylamino)phenyl)diazenyl)phenyl)ethanone (DPA)

International Nuclear Information System (INIS)

Surucu, Ozge; Abaci, Serdar; Seferoğlu, Zeynel

2016-01-01

Highlights: • Electrochemical characterization of azo dye DPA was performed. • Pencil graphite electrode was used as working electrode. • Cyclic voltammetry was used to determine the effect of scan rate and pH. • Chronoamperometry was used to determine diffusion constant. • Square wave voltammetry verified the results of cyclic voltammetry. - Abstract: An enormous range of possible dyes are available, especially as the starting molecules are readily available and cheap. As other dye classes become less viable from either an environmental or economic reasons, azo dyes come to the forefront. Therefore, electrochemical characterization of a novel synthesized azo dye (E)-1-(4-((4-(phenylamino) phenyl)diazenyl)phenyl)ethanone was achieved for the first time. Cyclic voltammetry, chronoamperometry and square wave voltammetry techniques were used to investigate the electrochemical behavior and electrocatalytic effect of azo dye (E)-1-(4-((4-(phenylamino) phenyl)diazenyl)phenyl)ethanone at pencil graphite electrode. Cyclic voltammograms were utilized to determine the effect of scan rate and pH on the peak current and peak potential. Chronoamperometry technique was used to determine diffusion constant, D and the type of adsorption isotherms. The kinetics parameters which were the apparent electron transfer rate constant, k s and charge transfer coefficient, α were calculated. Square wave voltammetry was used to verify responses of cyclic voltammetry technique.

Growth of KOH etched AZO nanorods and investigation of its back scattering effect in thin film a-Si solar cell

Science.gov (United States)

Sharma, Jayasree Roy; Mitra, Suchismita; Ghosh, Hemanta; Das, Gourab; Bose, Sukanta; Mandal, Sourav; Mukhopadhyay, Sumita; Saha, Hiranmay; Barua, A. K.

2018-02-01

In order to increase the stabilized efficiencies of thin film silicon (TFS) solar cells it is necessary to use better light management techniques. Texturization by etching of sputtered aluminum doped zinc oxide (Al:ZnO or AZO) films has opened up a variety of promises to optimize light trapping schemes. RF sputtered AZO film has been etched by potassium hydroxide (KOH). A systematic study of etching conditions such as etchant concentration, etching time, temperature management etc. have been performed in search of improved electrical and optical performances of the films. The change in etching conditions has exhibited a noticeable effect on the structure of AZO films for which the light trapping effect differs. After optimizing the etching conditions, nanorods have been found on the substrate. Hence, nanorods have been developed only by chemical etching, rather than the conventional development method (hydrothermal method, sol-gel method, electrolysis method etc.). The optimized etched substrate has 82% transmittance, moderate haze in the visible range and sheet resistance ∼13 (Ω/□). The developed nanorods (optimized etched substrate) provide better light trapping within the cell as the optical path length has been increased by using the nanorods. This provides an effect on carrier collection as well as the efficiency in a-Si solar cells. Finite difference time domain (FDTD) simulations have been performed to observe the light trapping by AZO nanorods formed on sputtered AZO films. For a p-i-n solar cell developed on AZO nanorods coated with sputtered AZO films, it has been found through simulations that, the incident light is back scattered into the absorbing layer, leading to an increase in photogenerated current and hence higher efficiency. It has been found that, the light that passes through the nanorods is not getting absorbed and maximum amount of light is back scattered towards the solar cell.

Preparation, spectral, X-ray powder diffraction and computational studies and genotoxic properties of new azo-azomethine metal chelates

Science.gov (United States)

Bitmez, Şirin; Sayin, Koray; Avar, Bariş; Köse, Muhammet; Kayraldız, Ahmet; Kurtoğlu, Mükerrem

2014-11-01

A new tridentate azo-azomethine ligand, N‧-[{2-hydroxy-5-[(4-nitrophenyl)diazenyl]phenyl}methylidene]benzohydrazidemonohydrate, (sbH·H2O) (1), is prepared by condensation of benzohydrazide and 2-hydroxy-5-[(4-nitrophenyl)diazenyl]benzaldehyde (a) with treatment of a solution of diazonium salt of p-nitroaniline and 2-hydroxybenzaldehyde in EtOH. The five coordination compounds, [Co(sb)2]·4H2O (2), [Ni(sb)2]·H2O (3), [Cu(sb)2]·4H2O (4), [Zn(sb)2]·H2O (5) and [Cd(sb)2]·H2O (6) are prepared by reacting the Co(II), Ni(II), Cu(II), Zn(II) and Cd(II) ions with the ligand. The structures of the compounds are elucidated from the elemental analyses data and spectroscopic studies. It is found the ligand acts as a tridentate bending through phenolic and carbonyl oxygens and nitrogen atom of the Cdbnd Nsbnd group similar to the most of salicylaldimines. Comparison of the infrared spectra of the ligand and its metal complexes confirm that azo-Schiff base behaves as a monobasic tridentate ligand towards the central metal ion with an ONO donor sequence. Upon complexation with the ligand, the Cd(II), and Zn(II) ions form monoclinic structures, while Co(II), Cu(II) and Ni(II) ions form orthorhombic structures. Quantum chemical calculations are performed on tautomers and its metal chelates by using DFT/B3LYP method. Most stable tautomer is determined as tautomer (1a). The geometrical parameters of its metal chelates are obtained as theoretically. The NLO properties of tautomer (1a) and its metal complexes are investigated. Finally, the ligand and its metal complexes are assessed for their genotoxicity.

O-heterocyclic derivatives with antibacterial properties from marine bacterium Bacillus subtilis associated with seaweed, Sargassum myriocystum.

Science.gov (United States)

Chakraborty, Kajal; Thilakan, Bini; Chakraborty, Rekha Devi; Raola, Vamshi Krishna; Joy, Minju

2017-01-01

The brown seaweed, Sargassum myriocystum associated with heterotrophic bacterium, Bacillus subtilis MTCC 10407 (JF834075) exhibited broad-spectra of potent antibacterial activities against pathogenic bacteria Aeromonas hydrophila, Vibrio vulnificus, and Vibrio parahaemolyticus. B. subtilis MTCC 10407 was found to be positive for polyketide synthetase (pks) gene, and therefore, was considered to characterize secondary metabolites bearing polyketide backbone. Using bioassay-guided fractionation, two new antibacterial O-heterocyclic compounds belonging to pyranyl benzoate analogs of polyketide origin, with activity against pathogenic bacteria, have been isolated from the ethyl acetate extract of B. subtilis MTCC 10407. In the present study, the secondary metabolites of B. subtilis MTCC 10407 with potent antibacterial action against bacterial pathogens was recognized to represent the platform of pks-1 gene-encoded products. Two homologous compounds 3 (3-(methoxycarbonyl)-4-(5-(2-ethylbutyl)-5,6-dihydro-3-methyl-2H-pyran-2-yl)-butyl benzoate) and 4 [2-(8-butyl-3-ethyl-3,4,4a,5,6,8a-hexahydro-2H-chromen-6-yl)-ethyl benzoate] also have been isolated from the ethyl acetate extract of host seaweed S. myriocystum. The two compounds isolated from ethyl acetate extract of S. myriocystum with lesser antibacterial properties shared similar structures with the compounds purified from B. subtilis that suggested the ecological and metabolic relationship between these compounds in seaweed-bacterial relationship. Tetrahydropyran-2-one moiety of the tetrahydropyrano-[3,2b]-pyran-2(3H)-one system of 1 might be cleaved by the metabolic pool of seaweeds to afford methyl 3-(dihydro-3-methyl-2H-pyranyl)-propanoate moiety of 3, which was found to have no significant antibacterial activity. It is therefore imperative that the presence of dihydro-methyl-2H-pyran-2-yl propanoate system is essentially required to impart the greater activity. The direct involvement of polarisability (Pl) with

An Improved Method for Removal of Azo Dye Orange II from Textile Effluent Using Albumin as Sorbent

Directory of Open Access Journals (Sweden)

Tadashi Ohashi

2012-11-01

Full Text Available Azo dyes are generally resistant to biodegradation due to their complex structures. Acid orange II is one of the most widely used dyes in the textile industry. The influence of bovine serum albumin (BSA in different concentrations, pH, and time of contact on Orange II was investigated using kinetics and adsorption-isotherm experiments. The results showed that the maximum colour removed from dye/albumin was 99.50% and that a stable dye-protein complex had been formed at pH 3.5 and in a proportion of 1:3 (v/v, respectively. The synthetic effluent did not show toxicity to the microcrustacean Artemia salina, and showed a CL50 equal to 97 µg/mL to azo dye orange II. Additionally, the methodology was effective in removing the maximum of orange II using BSA by adsorption at pH 3.5 which mainly attracted ions to the azo dye during the adsorption process. This suggests that this form of treatment is economical and easy to use which potentially could lead to bovine serum albumin being used as a sorbent for azo dyes.

Isolation and screening of azo dye decolorizing bacterial isolates from dye-contaminated textile wastewater

Directory of Open Access Journals (Sweden)

Shahid Mahmood

2011-04-01

Full Text Available Azo dyes are released into wastewater streams without any pretreatment and pollute water and soilenvironments. To prevent contamination of our vulnerable resources, removal of these dye pollutants is of greatimportance. For this purpose, wastewater samples were collected from dye-contaminated sites of Faisalabad. About200 bacterial isolates were isolated through enrichment and then tested for their potential to remove RemazolBlack-B azo dye in liquid medium. Five bacterial isolates capable of degrading Remazol Black-B azo dye efficientlywere screened through experimentation on modified mineral salt medium. Isolate SS1 (collected from wastewater ofSupreme Textile Industry was able to completely remove the Remazol Black-B dye from the liquid medium in 18 h.Further, the isolate showed the best performance at the dye concentration of 100 mg L-1 medium (pH 7 and attemperature 35oC. Similarly, yeast extract proved to be the best carbon source for decolorization purpose. Theresults imply that the isolate SS1 could be used for the removal of the reactive dyes from textile effluents.

Azo group containing compounds: investigation of the decay mechanism

Energy Technology Data Exchange (ETDEWEB)

Franzke, D; Kritzenberger, J; Kunz, T [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

1997-06-01

We investigated compounds containing the N=N-X (X=S,P,N{sub 3}) group which are potential candidates for microstructuring by photoresist technology or by photoablation. To elucidate the mechanism of thermal decomposition and photolysis we used infrared and UV spectroscopy, respectively, in solution as well as in the solid state. In this article we describe photolytic and thermolytic properties of one representative molecule for each of three substance classes: diazosulfides, azophosphonates and pentazadienes. (author) 4 figs., 4 refs.

Photolysis of Heterocyclic Lactones in Cryogenic Inert Matrices

International Nuclear Information System (INIS)

Kus, N.

2008-01-01

Heterocyclic lactones receive important uses in organic synthesis and are important biologically active compounds. Their weak toxicity and easy synthesis have made these compounds the subject of great interest and extensive investigation. Since long ago, lactones have been shown to possess an interesting photochemistry. Some representative six- and five-membered conjugated lactones [α-pyrone and some of its derivatives, including coumarin and 3-acetamido coumarin, 2(5H)-furanone] were recently investigated by infrared spectroscopy using the matrix isolation technique and quantum chemical calculations in our laboratories. Two main competitive photochemical reaction pathways could be identified: (i) ring-opening, leading to formation of the isomeric aldehyde-ketene, and (ii) ring-contraction leading to the corresponding Dewar isomers. For α-pyrone and 2(5H)-furanone, the ring-opening process dominates over the ring-contraction reaction, the same occurring for derivatives of these compounds bearing a voluminous substituent at position 3. In 2(5H)-furanone, the ring-opening reaction requires the simultaneous occurrence of a [1,2]-hydrogen atom migration, which was found to occur upon excitation at λ> 235 nm. Under the identical UV-irradiation (λ> 235 nm) of the six-membered analogues, the ring-opening reaction was more efficient in α-pyrone than in coumarin, and factors explaining this observation will be discussed. In turn, the Dewar forms of the studied compounds, resulting from the ring-contraction photoreaction, were found to undergo subsequent photo-elimination of CO 2 , with formation of the corresponding cycloalkenes. In the matrices, CO 2 and the simultaneously formed cycloalkenes were predicted by calculations to exist as associates, in which the CO 2 molecule is preferentially placed over the cycloalkene ring in a stacked-type geometry. For coumarin, a third photoreaction channel was observed, leading to formation of benzofurane and CO. This additional

Structural, spectral and magnetic studies of two Co(II)-N-heterocyclic diphosphonates based on multinuclear units

Science.gov (United States)

Zhao, Chen; Ma, Kui-Rong; Zhang, Yu; Kan, Yu-He; Li, Rong-Qing; Hu, Hua-You

2016-01-01

Two examples of Co(II)-N-heterocyclic coordination polymers based on 1-hydroxyethylidenediphosphonic acid (H5L = CH3C(OH)(PO3H2)2), namely 0.5(H3NCH2CH2NH3)·[Co6(Cl2)(H3L)2(H2L)(HL)(2,2‧-bipy)6] 1 and 2(NH4)·[Co3(HL)2(H2O)2(phen)2]·2(H2O) 2, have been solvothermally obtained by introducing the second ligands 2,2‧-bipyridine/1,10-phenanthroline (2,2‧-bipy/phen) and characterized by powder X-ray diffraction (PXRD), elemental analysis, IR, TG-DSC. The single-crystal X-ray diffractions show that compound 1 possesses a 0-D structure with hexa-nuclear cluster [Co6(O-P-O)8] built through single/double O-P-O bridges and compound 2 displays a 1-D ladder-like chain structure with magnetic topology building blocks [Co4(O-P-O)4]n. Then H-bonding and π-π stacking interactions further expand the two low-dimensional structures into three-dimensional supramolecular frameworks. Fluorescent measurements reveal that both the maximum emission peaks of 1-2 are centered at 423 nm, mainly deriving from intraligand π*-π transition state of N-heterocyclic ligand 2,2‧-bipy/phen, respectively. Magnetism data indicate that 1 exhibits antiferromagnetic behavior within hexa-nuclear Co(II) clusters, while 2 shows weak ferromagnetic interactions in 1-D topology Co(II)-chain, showing promising potential as magnetic materials.

The influence of target erosion grade in the optoelectronic properties of AZO coatings growth by magnetron sputtering

International Nuclear Information System (INIS)

Zubizarreta, C.; G-Berasategui, E.; Ciarsolo, I.; Barriga, J.; Gaspar, D.; Martins, R.; Fortunato, E.

2016-01-01

Graphical abstract: - Highlights: • High quality AZO films deposited at low temperature by RF magnetron sputtering. • Transmittance values of 84% and resistivity of 1.9 × 10"−"3 Ω cm were obtained. • Stable optoelectronic and structural properties during whole life of the target. • RF MS: robust and reliable for the industrial manufacture of AZO frontal electrode. - Abstract: Aluminum-doped zinc oxide (AZO) transparent conductor coating has emerged as promising substitute to tin-doped indium oxide (ITO) as electrode in optoelectronic applications such as photovoltaics or light emitting diodes (LEDs). Besides its high transmission in the visible spectral region and low resistivity, AZO presents a main advantage over other candidates such as graphene, carbon nanotubes or silver nanowires; it can be deposited using the technology industrially implemented to manufacture ITO layers, the magnetron sputtering (MS). This is a productive, reliable and green manufacturing technique. But to guarantee the robustness, reproducibility and reliability of the process there are still some issues to be addressed, such as the effect and control of the target state. In this paper a thorough study of the influence of the target erosion grade in developed coatings has been performed. AZO films have been deposited from a ceramic target by RF MS. Structure, optical transmittance and electrical properties of the produced coatings have been analyzed as function of the target erosion grade. No noticeable differences have been found neither in optoelectronic properties nor in the structure of the coatings, indicating that the RF MS is a stable and consistent process through the whole life of the target.

Features of the behavior of 4-amino-5-carboxamido-1,2,3-triazole in multicomponent heterocyclizations with carbonyl compounds

Directory of Open Access Journals (Sweden)

Eugene S. Gladkov

2012-11-01

Full Text Available Multicomponent reactions involving polyfunctional 4-amino-5-carboxamido-1,2,3-triazole and cyclic carbonyl-containing CH-acids were studied under conventional thermal heating, microwave and ultrasonic irradiation. The features of the reactions studied were discussed and the optimized procedures for the synthesis of final triazolopyrimidines were elaborated. In contrast to the similar MCRs of numerous other aminoazoles, a change of direction of the heterocyclizations in the case of 4-amino-5-carboxamido-1,2,3-triazole was not observed when microwave or thermal heating was substituted by ultrasonication at ambient temperature.

All-fiber maskless lithographic technology to form microcircular interference pattern on Azo polymer film

Science.gov (United States)

Kim, Junki; Jung, Yongmin; Oh, Kyunghwan; Chun, Chaemin; Hong, Jeachul; Kim, Dongyu

2005-03-01

We report a novel all-fiber, maskless lithograpic technology to form various concentric grating patterns for micro zone plate on azo polymer film. The proposed technology is based on the interference pattern out of the cleaved end of a coreless silica fiber (CSF)-single mode fiber (SMF) composite. The light guided along SMF expands into the CSF segment to generate various circular interference patterns depending on the length of CSF. Interference patterns are experimentally observed when the CSF length is over a certain length and the finer spacing between the concentric rings are obtained for a longer CSF. By using beam propagation method (BPM) package, we could further investigated the concentric interference patterns in terms of intensity distribution and fringe spacing as a function of CSF length. These intereference patterns are directly projected over azo polymer film and their intensity distrubution formed surface relief grating (SRG) patterns. Compared to photoresist films azo polymer layers produce surface relief grating (SRG), where the actual mass of layer is modulated rather than refractive index. The geometric parameters of the CSF length as well as diameter and the spacing between the cleaved end of a CSF and azo polymer film, were found to play a major role to generate various concentric structures. With the demonstration of the circular SRG patterns, we confirmed that the proposed technique do have an ample potential to fabricate micro fresnel zone plate, that could find applications in lens arrays for optical beam formings as well as compact photonic devices.

Influence of chemical structures on biodegradation of azo dyes by ...

African Journals Online (AJOL)

Influence of chemical structures on biodegradation of azo dyes by Pseudomonas sp. NA Oranusi, CJ Ogugbue. Abstract. No Abstract. Global Journal of Environmental Sciences Vol. 5(1) 2006: 19-25. Full Text: EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT.