Novel aminohydrazide cross-linked chitosan filled with multi-walled carbon nanotubes as antimicrobial agents.

PubMed

Mohamed, Nadia A; Abd El-Ghany, Nahed A

2018-04-21

Four chemically modified chitosan derivatives 1-4 were designed and synthesized via a series of four reactions; first by reaction with benzaldehyde to protect its amino groups (Derivative 1), second by reaction with epichlorohydrine (Derivative 2), third by reaction with aminobenzhydrazide (Derivative 3), and forth by removing of benzaldehyde to restore the free amino groups on the chitosan (Derivative 4). Two multi-walled carbon nanotube (MWCNT) biocomposites based on Derivative 4 were also prepared. The structure of the prepared derivatives and MWCNT composites was elucidated using elemental analyses, FTIR, XRD, SEM and TEM. The modified chitosan derivatives and MWCNT composites showed better antimicrobial activities than that of chitosan against Enterococcus faecalis, Staphylococcus epidermidis, Escherichia coli, Aspergillus niger, Cryptococcus neoformans and Candida tropicalis as judged by their higher inhibition zone diameters using the agar well diffusion technique. These derivatives and MWCNT composites are more potent against Gram-positive bacteria than against Gram-negative bacteria. The MWCNT composites displayed comparable or even better antimicrobial activities than the reference bactericides or fungicides. Thus, structural modification of chitosan through combination with functionalized moieties and MWCNTs in one system was taken as a way to achieve promising templates for antimicrobial agents and to be appropriate candidates for medical applications. Copyright © 2018 Elsevier B.V. All rights reserved.

Probing the molecular forces involved in binding of selected volatile flavour compounds to salt-extracted pea proteins.

PubMed

Wang, Kun; Arntfield, Susan D

2016-11-15

Molecular interactions between heterologous classes of flavour compounds with salt-extracted pea protein isolates (PPIs) were determined using various bond disrupting agents followed by GC/MS analysis. Flavour bound by proteins decreased in the order: dibutyl disulfide>octanal>hexyl acetate>2-octanone=benzaldehyde. Benzaldehyde, 2-octanone and hexyl acetate interacted non-covalently with PPIs, whereas octanal bound PPIs via covalent and non-covalent forces. Dibutyl disulfide reacted with PPIs covalently, as its retention was not diminished by urea and guanidine hydrochloride. Using propylene glycol, H-bonding and ionic interactions were implicated for hexyl acetate, benzaldehyde, and 2-octanone. A protein-destabilising salt (Cl3CCOONa) reduced bindings for 2-octanone, hexyl acetate, and benzaldehyde; however, retention for octanal and dibutyl disulfide increased. Conversely, a protein-stabilising salt (Na2SO4) enhanced retention for benzaldehyde, 2-octanone, hexyl acetate and octanal. Formation of a volatile flavour by-product, 1-butanethiol, from dibutyl disulfide when PPIs were treated with dithiothreitol indicated occurrence of sulfhydryl-disulfide interchange reactions. Copyright © 2016 Elsevier Ltd. All rights reserved.

Development of Multi-Component Transplant Mixes for Suppression of Meloidogyne incognita on Tomato (Lycopersicon esculentum)

PubMed Central

Kokalis-Burelle, N.; Martinez-Ochoa, N.; Rodríguez-Kábana, R.; Kloepper, J. W.

2002-01-01

The effects of combinations of organic amendments, phytochemicals, and plant-growth promoting rhizobacteria on tomato (Lycopersicon esculentum) germination, transplant growth, and infectivity of Meloidogyne incognita were evaluated. Two phytochemicals (citral and benzaldehyde), three organic amendments (pine bark, chitin, and hemicellulose), and three bacteria (Serratia marcescens, Brevibacterium iodinum, and Pseudomonas fluorescens) were assessed. Increasing rates of benzaldehyde and citral reduced nematode egg viability in vitro. Benzaldehyde was 100% efficacious as a nematicide against juveniles, whereas citral reduced juvenile viability to less than 20% at all rates tested. Benzaldehyde increased tomato seed germination and root weight, whereas citral decreased both. High rates of pine bark or chitin reduced plant growth but not seed germination, whereas low rates of chitin increased shoot length, shoot weight, and root weight; improved root condition; and reduced galling. The combination of chitin and benzaldehyde significantly improved tomato transplant growth and reduced galling. While each of the bacterial isolates contributed to increased plant growth in combination treatments, only Brevibacterium iodinum applied alone significantly improved plant growth. PMID:19265957

Enhanced sensitivity of self-assembled-monolayer-based SPR immunosensor for detection of benzaldehyde using a single-step multi-sandwich immunoassay.

PubMed

Gobi, K Vengatajalabathy; Matsumoto, Kiyoshi; Toko, Kiyoshi; Ikezaki, Hidekazu; Miura, Norio

2007-04-01

This paper describes the fabrication and sensing characteristics of a self-assembled monolayer (SAM)-based surface plasmon resonance (SPR) immunosensor for detection of benzaldehyde (BZ). The functional sensing surface was fabricated by the immobilization of a benzaldehyde-ovalbumin conjugate (BZ-OVA) on Au-thiolate SAMs containing carboxyl end groups. Covalent binding of BZ-OVA on SAM was found to be dependent on the composition of the base SAM, and it is improved very much with the use of a mixed monolayer strategy. Based on SPR angle measurements, the functional sensor surface is established as a compact monolayer of BZ-OVA bound on the mixed SAM. The BZ-OVA-bound sensor surface undergoes immunoaffinity binding with anti-benzaldehyde antibody (BZ-Ab) selectively. An indirect inhibition immunoassay principle has been applied, in which analyte benzaldehyde solution was incubated with an optimal concentration of BZ-Ab for 5 min and injected over the sensor chip. Analyte benzaldehyde undergoes immunoreaction with BZ-Ab and makes it inactive for binding to BZ-OVA on the sensor chip. As a result, the SPR angle response decreases with an increase in the concentration of benzaldehyde. The fabricated immunosensor demonstrates a low detection limit (LDL) of 50 ppt (pg mL(-1)) with a response time of 5 min. Antibodies bound to the sensor chip during an immunoassay could be detached by a brief exposure to acidic pepsin. With this surface regeneration, reusability of the same sensor chip for as many as 30 determination cycles has been established. Sensitivity has been enhanced further with the application of an additional single-step multi-sandwich immunoassay step, in which the BZ-Ab bound to the sensor chip was treated with a mixture of biotin-labeled secondary antibody, streptavidin and biotin-bovine serum albumin (Bio-BSA) conjugate. With this approach, the SPR sensor signal increased by ca. 12 times and the low detection limit improved to 5 ppt with a total response time of no more than ca. 10 min. Figure A single-step multi-sandwich immunoassay step increases SPR sensor signal by ca. 12 times affording a low detection limit for benzaldehyde of 5 ppt.

Intramolecular Benzoin Reaction Catalyzed by Benzaldehyde Lyase from Pseudomonas Fluorescens Biovar I.

PubMed

Hernández, Karel; Parella, Teodor; Petrillo, Giovanna; Usón, Isabel; Wandtke, Claudia M; Joglar, Jesús; Bujons, Jordi; Clapés, Pere

2017-05-02

Intramolecular benzoin reactions catalyzed by benzaldehyde lyase from Pseudomonas fluorescens biovar I (BAL) are reported. The structure of the substrates envisaged for this reaction consists of two benzaldehyde derivatives linked by an alkyl chain. The structural requirements needed to achieve the intramolecular carbon-carbon bond reaction catalyzed by BAL were established. Thus, a linker consisting of a linear alkyl chain of three carbon atoms connected through ether-type bonds to the 2 and 2' positions of two benzaldehyde moieties, which could be substituted with either Cl, Br, or OCH 3 at either the 3 and 3' or 5 and 5' positions, were suitable substrates for BAL. Reactions with 61-84 % yields of the intramolecular product and ee values between 64 and 98 %, were achieved. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Probing the Active Center of Benzaldehyde Lyase with Substitutions and the Pseudosubstrate Analogue Benzoylphosphonic Acid Methyl Ester

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brandt, Gabriel S.; Nemeria, Natalia; Chakraborty, Sumit

2008-07-28

Benzaldehyde lyase (BAL) catalyzes the reversible cleavage of (R)-benzoin to benzaldehyde utilizing thiamin diphosphate and Mg{sup 2+} as cofactors. The enzyme is important for the chemoenzymatic synthesis of a wide range of compounds via its carboligation reaction mechanism. In addition to its principal functions, BAL can slowly decarboxylate aromatic amino acids such as benzoylformic acid. It is also intriguing mechanistically due to the paucity of acid-base residues at the active center that can participate in proton transfer steps thought to be necessary for these types of reactions. Here methyl benzoylphosphonate, an excellent electrostatic analogue of benzoylformic acid, is used tomore » probe the mechanism of benzaldehyde lyase. The structure of benzaldehyde lyase in its covalent complex with methyl benzoylphosphonate was determined to 2.49 {angstrom} (Protein Data Bank entry 3D7K) and represents the first structure of this enzyme with a compound bound in the active site. No large structural reorganization was detected compared to the complex of the enzyme with thiamin diphosphate. The configuration of the predecarboxylation thiamin-bound intermediate was clarified by the structure. Both spectroscopic and X-ray structural studies are consistent with inhibition resulting from the binding of MBP to the thiamin diphosphate in the active centers. We also delineated the role of His29 (the sole potential acid-base catalyst in the active site other than the highly conserved Glu50) and Trp163 in cofactor activation and catalysis by benzaldehyde lyase.« less

Probing the active center of benzaldehyde lyase with substitutions and the pseudo-substrate analog benzoylphosphonic acid methyl ester

PubMed Central

Brandt, Gabriel S.; Nemeria, Natalia; Chakraborty, Sumit; McLeish, Michael J.; Yep, Alejandra; Kenyon, George L.; Petsko, Gregory A.; Jordan, Frank; Ringe, Dagmar

2009-01-01

Benzaldehyde lyase (BAL) catalyzes the reversible cleavage of (R)-benzoin to benzaldehyde utilizing thiamin diphosphate and Mg2+ as cofactors. The enzyme is important for the chemoenzymatic synthesis of a wide range of compounds via its carboligation reaction mechanism. In addition to its principal functions, BAL can slowly decarboxylate aromatic amino acids such as benzoylformic acid. It is also intriguing mechanistically due to the paucity of acid-base residues at the active center that can participate in proton transfer steps thought to be necessary for these type of reactions. Here methyl benzoylphosphonate, an excellent electrostatic analog of benzoylformic acid, is used to probe the mechanism of benzaldehyde lyase. The structure of benzaldehyde lyase in its covalent complex with methyl benzoylphosphonate was determined to 2.49 Å (PDB ID: 3D7K) and represents the first structure of this enzyme with a compound bound in the active site. No large structural reorganization was detected compared to the complex of the enzyme with thiamin diphosphate. The configuration of the predecarboxylation thiamin-bound intermediate was clarified by the structure. Both spectroscopic and X-ray structural studies are consistent with inhibition resulting from the binding of MBP to the thiamin diphosphate in the active centers. We also delineated the role of His29 (the sole potential acid-base catalyst in the active site other than the highly conserved Glu50) and Trp163 in cofactor activation and catalysis by benzaldehyde lyase. PMID:18570438

Rate and Equilibrium Constants for the Addition of N-Heterocyclic Carbenes into Benzaldehydes: A Remarkable 2-Substituent Effect**

PubMed Central

Collett, Christopher J; Massey, Richard S; Taylor, James E; Maguire, Oliver R; O'Donoghue, AnnMarie C; Smith, Andrew D

2015-01-01

Rate and equilibrium constants for the reaction between N-aryl triazolium N-heterocyclic carbene (NHC) precatalysts and substituted benzaldehyde derivatives to form 3-(hydroxybenzyl)azolium adducts under both catalytic and stoichiometric conditions have been measured. Kinetic analysis and reaction profile fitting of both the forward and reverse reactions, plus onwards reaction to the Breslow intermediate, demonstrate the remarkable effect of the benzaldehyde 2-substituent in these reactions and provide insight into the chemoselectivity of cross-benzoin reactions. PMID:25908493

Rate and Equilibrium Constants for the Addition of N‐Heterocyclic Carbenes into Benzaldehydes: A Remarkable 2‐Substituent Effect†

PubMed Central

Collett, Christopher J.; Massey, Richard S.; Taylor, James E.; Maguire, Oliver R.

2015-01-01

Abstract Rate and equilibrium constants for the reaction between N‐aryl triazolium N‐heterocyclic carbene (NHC) precatalysts and substituted benzaldehyde derivatives to form 3‐(hydroxybenzyl)azolium adducts under both catalytic and stoichiometric conditions have been measured. Kinetic analysis and reaction profile fitting of both the forward and reverse reactions, plus onwards reaction to the Breslow intermediate, demonstrate the remarkable effect of the benzaldehyde 2‐substituent in these reactions and provide insight into the chemoselectivity of cross‐benzoin reactions. PMID:27478264

Benzaldehyde

Integrated Risk Information System (IRIS)

Benzaldehyde ; CASRN 100 - 52 - 7 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic Effe

The Kinetic Behavior of Benzaldehyde under Hydrothermal Conditions

NASA Astrophysics Data System (ADS)

Fecteau, K.; Gould, I.; Hartnett, H. E.; Williams, L. B.; Shock, E.

2013-12-01

Aldehydes represent an intermediate redox state between alcohols and carboxylic acids and are likely intermediates in the transformation of organic compounds in natural systems. We have conducted kinetic studies of a model aldehyde, benzaldehyde, in high-temperature water (250-350 °C, saturation pressure) in clear fused quartz (CFQ) autoclaves. Under these conditions, benzaldehyde is observed to undergo a disproportionation reaction to benzyl alcohol and benzoic acid reminiscent of the base-catalyzed Cannizzaro reaction known to occur at cooler temperatures. Benzene is also produced via decarbonylation of the aldehyde. We have obtained pseudo second-order rate constants for the decomposition of benzaldehyde at 250, 300, and 350 °C. Rates derived via repeated heating phases and subsequent quantitative 13C-NMR spectroscopy of a single NMR-compatible CFQ tube containing isotopically labeled benzaldehyde are consistent with those obtained by analysis of product suites from individual timed experiments via gas chromatography. Arrhenius parameters for these rate constants are consistent with published values for the reaction under supercritical conditions from one study (Tsao et al. 1992) yet the pre-exponential factor is approximately 7 orders of magnitude smaller than that derived from another study (Ikushima et al. 2001). Moreover, fitting our rate constants with the Eyring equation yields an entropy of activation (ΔS‡) of -26.6 kcal mol-1 K-1, which is consistent for a bimolecular transition state at the rate-limiting step. In contrast, the rates of Ikushima et al. yield a positive value of ΔS‡, which is inconsistent with the putative mechanism for the reaction. The linear Arrhenius behavior of the decomposition of benzaldehyde from high-temperature liquid to supercritical conditions demonstrates the potential for extrapolating experimentally derived rates of reactions for organic functional group transformations to conditions where diagenesis, alteration, metamorphism, and other hydrothermal processes of interest occur in natural systems. References Ikushima, Y., K. Hatakeda, O. Sato, T. Yokoyama, and M. Arai. 2001. Structure and base catalysis of supercritical water in the noncatalytic benzaldehyde disproportionation using water at high temperatures and pressures. Angewandte Chemie, 40, 210-213. Tsao, C.C., Y. Zhou, X. Liu, and T.J. Houser. 1992. Reactions of supercritical water with benzaldehyde, benzylidenebenzylamine, benzyl alcohol, and benzoic acid. The Journal of Supercritical Fluids, 5, 107-113.

Hepatoprotective effect of acetone semicarbazone on Ehrlich ascites carcinoma induced carcinogenesis in experimental mice

PubMed Central

Islam, Farhadul; Ali, Shaikh Mohummad Mohsin; Khanam, Jahan Ara

2013-01-01

Objective To determine the hepatoprotective effect of acetone semicarbazone (ASC) in vivo in normal and Ehrlich ascites carcinoma (EAC) bearing male Swiss albino mice. Methods Drug-induced changes in biochemical and behavioral parameters at dose of 2.0 mg/kg body weight for 14 d and nullifying the toxicity induced by EAC cells were studied. The histopathology studies of the protective effects of ASC on vital organs were also assessed. Results The administration of ASC made insignificant changes in body weight and behavioral (salivation, diarrhea, muscular numbness) changes during treatment period due to minor toxicity were minimized after the treatment in normal mice. The biochemical parameters, including serum glutamate pyruvate transaminase, glutamate oxaloactate transaminase, alkaline phosphatase, serum glucose, cholesterol, urea, triglyceride and billirubin changed modestly in normal mice receiving ASC. Though the treatment continued, these values gradually decreased to normal level after the treatment. In EAC bearing mice, the toxic effects due to EAC cells in all cases were nullified by treatment with the ASC. Significant abnormalities were not detected in histology of the various organs of the normal mice treated with ASC. Conclusions ASC can, therefore, be considered safe in formulating novel anticancer drug, as it exhibits strong protective effect against EAC cell bearing mice. PMID:23593588

Exploration of a Library of 3,4-(Methylenedioxy)aniline-Derived Semicarbazones as Dual Inhibitors of Monoamine Oxidase and Acetylcholinesterase: Design, Synthesis, and Evaluation.

PubMed

Tripathi, Rati K P; Rai, Gopal K; Ayyannan, Senthil R

2016-06-06

A library of 3,4-(methylenedioxy)aniline-derived semicarbazones was designed, synthesized, and evaluated as monoamine oxidase (MAO) and acetylcholinesterase (AChE) inhibitors for the treatment of neurodegenerative diseases. Most of the new compounds selectively inhibited MAO-B and AChE, with IC50 values in the micro- or nanomolar ranges. Compound 16, 1-(2,6-dichlorobenzylidene)-4-(benzo[1,3]dioxol-5-yl)semicarbazide presented a balanced multifunctional profile of MAO-A (IC50 =4.52±0.032 μm), MAO-B (IC50 =0.059±0.002 μm), and AChE (IC50 =0.0087±0.0002 μm) inhibition without neurotoxicity. Kinetic studies revealed that compound 16 exhibits competitive and reversible inhibition against MAO-A and MAO-B, and mixed-type inhibition against AChE. Molecular docking studies further revealed insight into the possible interactions within the enzyme-inhibitor complexes. The most active compounds were found to interact with the enzymes through hydrogen bonding and hydrophobic interactions. Additionally, in silico molecular properties and ADME properties of the synthesized compounds were calculated to explore their drug-like characteristics. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Green synthesis of some novel dioxolane compounds from Indonesian essential oils as potential biogreases

NASA Astrophysics Data System (ADS)

Wahyuningsih, Tutik Dwi; Kurniawan, Yehezkiel Steven

2017-03-01

Greases are mostly prepared from petroleum base stocks that make it toxic to the environment. The demand for green greases has led to in depth research of other renewable resources. Vegetable oils are promising candidates due to their renewability and low toxicity. However, it has poor oxidation stability and high total acid number. One way to solve this problem is chemical modification of its fatty acid structure. We report some novel dioxolane compounds from oleic acid and benzaldehyde derivates from some Indonesian essential oils via several steps, i.e: hydroxylation, esterification and acetalization. The esterification and acetalization reaction was carried out by green procedure using sonochemical method and montmorillonite KSF as a catalyst. Hydroxylation of Oleic acid was performed by KMnO4 to give 9,10-dihydroxyoctadecanoic (DHOA) in 47% yield. The esterification was done using methanol yielded methyl 9,10-dihydroxyoctadecanoate (MDHO) as white powder in 94%. Acetalization of the ester MDO with various benzaldehyde derivatives was carried out to give the dioxolan derivatives in the range of 17 - 60% yield. All of the structure was confirmed by FT-IR and GC-MS, meanwhile their physicochemical properties were determined using ASTM methods. From physicochemical properties, i.e: -TAN, TBN and IV-, it can be concluded that these novel compounds have the potential to be developed into biogrease.

Highly selective oxidation of styrene to benzaldehyde over a tailor-made cobalt oxide encapsulated zeolite catalyst.

PubMed

Liu, Jiangyong; Wang, Zihao; Jian, Panming; Jian, Ruiqi

2018-05-01

A tailor-made catalyst with cobalt oxide particles encapsulated into ZSM-5 zeolites (Co 3 O 4 @HZSM-5) was prepared via a hydrothermal method with the conventional impregnated Co 3 O 4 /SiO 2 catalyst as the precursor and Si source. Various characterization results show that the Co 3 O 4 @HZSM-5 catalyst has well-organized structure with Co 3 O 4 particles compatibly encapsulated in the zeolite crystals. The Co 3 O 4 @HZSM-5 catalyst was employed as an efficient catalyst for the selective oxidation of styrene to benzaldehyde with hydrogen peroxide as a green and economic oxidant. The effect of various reaction conditions including reaction time, reaction temperature, different kinds of solvents, styrene/H 2 O 2 molar ratio and catalyst dosage on the catalytic performance were systematically investigated. Under the optimized reaction condition, the yield of benzaldehyde can achieve 78.9% with 96.8% styrene conversion and 81.5% benzaldehyde selectivity. Such an excellent catalytic performance can be attributed to the synergistic effect between the confined reaction environment and the proper acidic property. In addition, the reaction mechanism with Co 3 O 4 @HZSM-5 as the catalyst for the selective oxidation of styrene to benzaldehyde was reasonably proposed. Copyright © 2018 Elsevier Inc. All rights reserved.

Hydroacylation of 2-vinyl benzaldehyde systems: an efficient method for the synthesis of chiral 3-substituted indanones.

PubMed

Kundu, Kousik; McCullagh, James V; Morehead, Andrew T

2005-11-23

Asymmetric rhodium-catalyzed hydroacylation has been utilized in the synthesis of 3-substituted indanones with high conversions and enantioselectivity. The hydroacylation reaction of 2-vinyl benzaldehyde had been previously reported to give a low yield of indanone and an unidentified product. We have identified this compound as a dimer of the starting material. Substitution at the alpha-position of the 2-vinyl benzaldehyde substrates blocks the competitive dimerization reaction and allows the reaction to proceed with yields generally greater than 90%. Utilization of BINAP as a chiral ligand results in good chemical yields and enantioselectivity greater than 95% in most cases.

Hydrogen bonds and antiviral activity of benzaldehyde derivatives

NASA Astrophysics Data System (ADS)

Tolstorozhev, G. B.; Skornyakov, I. V.; Belkov, M. V.; Shadyro, O. I.; Brinkevich, S. D.; Samovich, S. N.

2012-09-01

We have obtained the Fourier transform IR spectra of solutions of benzaldehyde derivatives having different antiviral activities against a herpes virus. We observe a correlation between the presence of hydrogen bonds in the benzaldehyde molecules and the appearance of antiviral properties in the compounds. For compounds having antiviral activity, we have obtained spectral data suggesting the existence of hydrogen bonds of the type C=OṡṡṡH-O and O-HṡṡṡO in the molecules. When the hydrogen atom in the hydroxyl groups are replaced by a methyl group, no intramolecular hydrogen bonds are formed and the compounds lose their antiviral activity.

Antifungal activity of redox-active benzaldehydes that target cellular antioxidation

USDA-ARS?s Scientific Manuscript database

Many pathogenic fungi are becoming resistant to currently available drugs. Disruption of cellular antioxidation systems should be an effective method for control of fungal pathogens. Such disruption can be achieved with redox-active compounds. The aim of this study was to identify benzaldehydes that...

Origin of the selectivity in the gold-mediated oxidation of benzyl alcohol

NASA Astrophysics Data System (ADS)

Rodríguez-Reyes, Juan Carlos F.; Friend, Cynthia M.; Madix, Robert J.

2012-08-01

Benzyl alcohol has received substantial attention as a probe molecule to test the selectivity and efficiency of novel metallic gold catalysts. Herein, the mechanisms of benzyl alcohol oxidation on a gold surface covered with atomic oxygen are elucidated; the results show direct correspondence to the reaction on gold-based catalysts. The selective, partial oxidation of benzyl alcohol to benzaldehyde is achieved with low oxygen surface concentrations and takes place through dehydrogenation of the alcohol to form benzaldehyde via a benzyloxy (C6H5-CH2O) intermediate. While in this case atomic oxygen plays solely a dehydrogenating role, at higher concentrations it leads to the formation of intermediates from benzaldehyde, producing benzoic acid and CO2. Facile ester (benzyl benzoate) formation also occurs at low oxygen concentrations, which indicates that benzoic acid is not a precursor of further oxidation of the ester; instead, the ester is produced by the coupling of adsorbed benzyloxy and benzaldehyde. Key to the high selectivity seen at low oxygen concentrations is the fact that the production of the aldehyde (and esters) is kinetically favored over the production of benzoic acid.

Structure of the ThDP-dependent enzyme benzaldehyde lyase refined to 1.65 Å resolution

DOE Office of Scientific and Technical Information (OSTI.GOV)

Maraite, Andy; Schmidt, Thomas; Ansörge-Schumacher, Marion B.

2007-07-01

The X-ray crystal structure of the ThDP-dependent enzyme benzaldehyde lyase has been refined to 1.65 Å. Benzaldehyde lyase (BAL; EC 4.1.2.38) is a thiamine diphosphate (ThDP) dependent enzyme that catalyses the enantioselective carboligation of two molecules of benzaldehyde to form (R)-benzoin. BAL has hence aroused interest for its potential in the industrial synthesis of optically active benzoins and derivatives. The structure of BAL was previously solved to a resolution of 2.6 Å using MAD experiments on a selenomethionine derivative [Mosbacher et al. (2005 ▶), FEBS J.272, 6067–6076]. In this communication of parallel studies, BAL was crystallized in an alternative spacemore » group (P2{sub 1}2{sub 1}2{sub 1}) and its structure refined to a resolution of 1.65 Å, allowing detailed observation of the water structure, active-site interactions with ThDP and also the electron density for the co-solvent 2-methyl-2,4-pentanediol (MPD) at hydrophobic patches of the enzyme surface.« less

Quantification of brown dog tick repellents, 2-hexanone and benzaldehyde, and release from tick-resistant beagles, Canis lupus familiaris

USDA-ARS?s Scientific Manuscript database

We have recently shown that repellency of the tick Rhipicephalus sanguineus sensu lato by the tick resistant dog breed Beagle is mediated by volatile organic compounds 2-hexanone and benzaldehyde present in Beagle dog odour. Ectoparasite location on animal hosts is affected by variation in odour com...

OZONE REACTION WITH N-ALDEHYDES (N=4-10), BENZALDEHYDE, ETHANOL, ISOPROPANOL, AND N-PROPANOL ADSORBED ON A DUAL-BED GRAPHITIZED CARBON/CARBON MOLECULAR SIEVE ADSORBENT CARTRIDGE

EPA Science Inventory

Ozone reacts with n-aldehydes (n = 4 - 10), benzaldehyde, ethanol, isopropanol, and n-propanol adsorbed on a dual-bed graphitized carbon/carbon molecular sieve adsorbent cartridge. Destruction of n-aldehydes increases with n number and with ozone concentration. In some samp...

Oxidation of benzyl alcohol by K2FeO4 to benzaldehyde over zeolites

NASA Astrophysics Data System (ADS)

Wang, Yuan-Yuan; Song, Hua; Song, Hua-Lin; Jin, Zai-Shun

2016-10-01

A novel and green procedure for benzaldehyde synthesis by potassium ferrate oxidation of benzyl alcohol employing zeolite catalysts was studied. The prepared oxidant was characterized by SEM and XRD. The catalytic activity of various solid catalysts was studied using benzyl alcohol as a model compound. USY was found to be a very efficient catalyst for this particular oxidation process. Benzaldehyde yields up to 96.0% could be obtained at the following optimal conditions: 0.2 mL of benzyl alcohol, 4 mmol of K2FeO4, 0.5 g of USY zeolite; 20 mL of cyclohexene, 0.3 mL of acetic acid (36 wt %), 30°C temperature, 4 h reaction time.

Serotonin Mediates a Learned Increase in Attraction to High Concentrations of Benzaldehyde in Aged "C. elegans"

ERIC Educational Resources Information Center

Tsui, David; van der Kooy, Derek

2008-01-01

We utilized olfactory-mediated chemotaxis in "Caenorhabditis elegans" to examine the effect of aging on information processing and animal behavior. Wild-type (N2) young adults (day 4) initially approach and eventually avoid a point source of benzaldehyde. Aged adult animals (day 7) showed a stronger initial approach and a delayed avoidance to…

Characterization and analysis of diesel exhaust odor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shala, F.J.

1983-01-01

An instrumental method known as the Diesel Odor Analysis System or DOAS, has been developed at A.D. Little, Inc. for measuring diesel exhaust odor. It was of interest to determine which compound or compounds in the oxygenated fraction of the exhaust were primarily responsible for the odor correlation as developed at A.D. Little, Inc. This was accomplished by observing how the measurement of the exhaust odor intensity and number of chemical constituents of the oxygenate fraction were changing with respect to the odor values as measured by the DOAS. Benzaldehyde was found to give the best correlation (R = 0.98)more » with odor. A quantitative relationship between exhaust odor as measured by the total intensity of aroma (TIA) and the benzaldehyde concentration (B) in ppm in the exhaust is given by: TIA = 1.11 log/sub 10/(B) + 4.10. This correlation was supported by results obtained from two other diesel engine exhaust sources. A methyl benzaldehyde isomer also yielded a good correlation (R = 0.90) with odor. Air to fuel ratio correlations were determined for the tentatively identified compounds, cinnamaldehyde (R = 0.94) and a C2-benzaldehyde isomer (R = 0.94).« less

Polydopamine-Coated TiO2 Nanotubes for Selective Photocatalytic Oxidation of Benzyl Alcohol to Benzaldehyde Under Visible Light.

PubMed

Tripathy, Jyotsna; Loget, Gabriel; Altomare, Marco; Schmuki, Patrik

2016-05-01

TiO2 nanotube arrays grown by anodization were coated with thin layers of polydopamine as visible light sensitizer. The PDA-coated TiO2 scaffolds were used as photocatalyst for selective oxidation of benzyl alcohol under monochromatic irradiation at 473 nm. Benzaldehyde was selectively formed and no by-products could be detected. A maximized reaction yield was obtained in O2-saturated acetonitrile. A mechanism is proposed that implies firstly the charge carrier generation in polydopamine as a consequence of visible light absorption. Secondly, photo-promoted electrons are injected in TiO2 conduction band, and subsequently transferred to dissolved O2 to form O*2- radicals. These radicals react with benzyl alcohol and lead to its selective dehydrogenation oxidation towards benzaldehyde.

Photoelectrochemical detection of benzaldehyde in foodstuffs

DOE Office of Scientific and Technical Information (OSTI.GOV)

LaCourse, W.R.; Krull, I.S.

Photoelectrochemical detection (PED) coupled with high performance liquid chromatography was used to quantitatively determine benzaldehyde in extracts, beverages, and foodstuffs. Photoelectrochemical detection is responsive to alkyl and aryl ketones and aldehydes and offers the advantages of 2-3 orders of magnitude linearity, 5-1-ng limits of detection, and a high degree of selectivity without chemical derivatization. This is the first application of the PED to sample analysis.

Biomass pyrolysis: Thermal decomposition mechanisms of furfural and benzaldehyde

NASA Astrophysics Data System (ADS)

Vasiliou, AnGayle K.; Kim, Jong Hyun; Ormond, Thomas K.; Piech, Krzysztof M.; Urness, Kimberly N.; Scheer, Adam M.; Robichaud, David J.; Mukarakate, Calvin; Nimlos, Mark R.; Daily, John W.; Guan, Qi; Carstensen, Hans-Heinrich; Ellison, G. Barney

2013-09-01

The thermal decompositions of furfural and benzaldehyde have been studied in a heated microtubular flow reactor. The pyrolysis experiments were carried out by passing a dilute mixture of the aromatic aldehydes (roughly 0.1%-1%) entrained in a stream of buffer gas (either He or Ar) through a pulsed, heated SiC reactor that is 2-3 cm long and 1 mm in diameter. Typical pressures in the reactor are 75-150 Torr with the SiC tube wall temperature in the range of 1200-1800 K. Characteristic residence times in the reactor are 100-200 μsec after which the gas mixture emerges as a skimmed molecular beam at a pressure of approximately 10 μTorr. Products were detected using matrix infrared absorption spectroscopy, 118.2 nm (10.487 eV) photoionization mass spectroscopy and resonance enhanced multiphoton ionization. The initial steps in the thermal decomposition of furfural and benzaldehyde have been identified. Furfural undergoes unimolecular decomposition to furan + CO: C4H3O-CHO (+ M) → CO + C4H4O. Sequential decomposition of furan leads to the production of HC≡CH, CH2CO, CH3C≡CH, CO, HCCCH2, and H atoms. In contrast, benzaldehyde resists decomposition until higher temperatures when it fragments to phenyl radical plus H atoms and CO: C6H5CHO (+ M) → C6H5CO + H → C6H5 + CO + H. The H atoms trigger a chain reaction by attacking C6H5CHO: H + C6H5CHO → [C6H6CHO]* → C6H6 + CO + H. The net result is the decomposition of benzaldehyde to produce benzene and CO.

Synthesis and accumulation of aromatic aldehydes in an engineered strain of Escherichia coli.

PubMed

Kunjapur, Aditya M; Tarasova, Yekaterina; Prather, Kristala L J

2014-08-20

Aromatic aldehydes are useful in numerous applications, especially as flavors, fragrances, and pharmaceutical precursors. However, microbial synthesis of aldehydes is hindered by rapid, endogenous, and redundant conversion of aldehydes to their corresponding alcohols. We report the construction of an Escherichia coli K-12 MG1655 strain with reduced aromatic aldehyde reduction (RARE) that serves as a platform for aromatic aldehyde biosynthesis. Six genes with reported activity on the model substrate benzaldehyde were rationally targeted for deletion: three genes that encode aldo-keto reductases and three genes that encode alcohol dehydrogenases. Upon expression of a recombinant carboxylic acid reductase in the RARE strain and addition of benzoate during growth, benzaldehyde remained in the culture after 24 h, with less than 12% conversion of benzaldehyde to benzyl alcohol. Although individual overexpression results demonstrated that all six genes could contribute to benzaldehyde reduction in vivo, additional experiments featuring subset deletion strains revealed that two of the gene deletions were dispensable under the conditions tested. The engineered strain was next investigated for the production of vanillin from vanillate and succeeded in preventing formation of the byproduct vanillyl alcohol. A pathway for the biosynthesis of vanillin directly from glucose was introduced and resulted in a 55-fold improvement in vanillin titer when using the RARE strain versus the wild-type strain. Finally, synthesis of the chiral pharmaceutical intermediate L-phenylacetylcarbinol (L-PAC) was demonstrated from benzaldehyde and glucose upon expression of a recombinant mutant pyruvate decarboxylase in the RARE strain. Beyond allowing accumulation of aromatic aldehydes as end products in E. coli, the RARE strain expands the classes of chemicals that can be produced microbially via aldehyde intermediates.

Cu and Boron Doped Carbon Nitride for Highly Selective Oxidation of Toluene to Benzaldehyde.

PubMed

Han, Hongling; Ding, Guodong; Wu, Tianbin; Yang, Dexin; Jiang, Tao; Han, Buxing

2015-07-13

A novel Cu and boron doped graphitic carbon nitride catalyst (Cu-CNB) was synthesized using cheap precursors and systematically characterized. The selective oxidation of toluene proceeded very smoothly over the catalyst at 70 °C using tert-butyl hydroperoxide (TBHP) as the oxidant to exclusively afford benzaldehyde. The catalyst can be used for at least five cycles without decrease in activity and selectivity.

Chaetopyranin, a benzaldehyde derivative, and other related metabolites from Chaetomium globosum, an endophytic fungus derived from the marine red alga Polysiphonia urceolata.

PubMed

Wang, Song; Li, Xiao-Ming; Teuscher, Franka; Li, Dong-Li; Diesel, Arnulf; Ebel, Rainer; Proksch, Peter; Wang, Bin-Gui

2006-11-01

Cultivation of the endophytic fungus Chaetomium globosum, which was isolated from the inner tissue of the marine red alga Polysiphonia urceolata, resulted in the isolation of chaetopyranin (1), a new benzaldehyde secondary metabolite. Ten known compounds were also isolated, including two benzaldehyde congeners, 2-(2',3-epoxy-1',3'-heptadienyl)-6-hydroxy-5-(3-methyl-2-butenyl)benzaldehyde (2) and isotetrahydroauroglaucin (3), two anthraquinone derivatives, erythroglaucin (4) and parietin (5), five asperentin derivatives including asperentin (6, also known as cladosporin), 5'-hydroxy-asperentin-8-methylether (7), asperentin-8-methyl ether (8), 4'-hydroxyasperentin (9), and 5'-hydroxyasperentin (10), and the prenylated diketopiperazine congener neoechinulin A (11). The structures of these compounds were determined on the basis of their spectroscopic data analysis (1H, 13C, 1H-1H COSY, HMQC, and HMBC NMR, as well as low- and high-resolution mass experiments). To our knowledge, compound 1 represents the first example of a 2H-benzopyran derivative of marine algal-derived fungi as well as of the fungal genus Chaetomium. Each isolate was tested for its DPPH (1,1-diphenyl-2-picrylhydrazyl) radical-scavenging property. Compounds 1-4 were found to have moderate activity. Chaetopyranin (1) also exhibited moderate to weak cytotoxic activity toward several tumor cell lines.

Solvo-thermal synthesis of a unique alkaline earth-transition Ba-Cd micro-porous coordination framework as hetero-metallic luminescent sensor for Cu2+ and real-time detection of benzaldehyde

NASA Astrophysics Data System (ADS)

Ding, Bin; Ma, Dian Xue; Zhang, Hui Min; Meng, Xin; Qiu, Rong Rong; Ren, Rong; Wu, Jie; Wu, Xiang Xia; Huo, Jian Zhong; Liu, Yuan Yuan; Shi, Xue Fang

2018-06-01

In this work a unique hetero-metallic alkaline earth-transition Ba-Cd luminescent micro-porous metal-organic framework {[BaCd(μ6-tp)1.5(μ2-Cl)(H2O) (DMF)2]·0.75H2O}n (H2tp = terephthalic acid) (1) has been prepared under solvo-thermal conditions. In 1 infinite 1D {Ba-X-Cd} (X = O, Cl) inorganic chains are linked via these full de-pronated tp2- ligands forming a unique 3D I1O2 type micro-porous coordination framework. PXRD patterns of 1 have been determined confirming pure phases of 1. Luminescence investigations suggested that 1 exhibits highly selective and sensitive sensing for trace amounts of benzaldehyde in ethanol, which provides a facile method for real-time detection of benzaldehyde. Meanwhile 1 also exhibits highly selective and sensitive sensing for Cu2+ over other cations with high quenching efficiency Ksv value 1.15 × 104 L·mol-1. As far as we know, 1 represents the first example of alkaline earth-transition hetero-metallic Ba-Cd micro-porous coordination framework as bi-functional luminescent probes for Cu2+ and benzaldehyde.

Field background odour should be taken into account when formulating a pest attractant based on plant volatiles

PubMed Central

Cai, Xiaoming; Bian, Lei; Xu, Xiuxiu; Luo, Zongxiu; Li, Zhaoqun; Chen, Zongmao

2017-01-01

Attractants for pest monitoring and controlling can be developed based on plant volatiles. Previously, we showed that tea leafhopper (Empoasca onukii) preferred grapevine, peach plant, and tea plant odours to clean air. In this research, we formulated three blends with similar attractiveness to leafhoppers as peach, grapevine, and tea plant volatiles; these blends were composed of (Z)-3-hexenyl acetate, (E)-ocimene, (E)-4,8-dimethyl-1,3,7-nonatriene, benzaldehyde, and ethyl benzoate. Based on these five compounds, we developed two attractants, formula-P and formula-G. The specific component relative to tea plant volatiles in formula-P was benzaldehyde, and that in formula-G was ethyl benzoate. These two compounds played a role in attracting leafhoppers. In laboratory assays, the two attractants were more attractive than tea plant volatiles to the leafhoppers, and had a similar level of attractiveness. However, the leafhoppers were not attracted to formula-P in the field. A high concentration of benzaldehyde was detected in the background odour of the tea plantations. In laboratory tests, benzaldehyde at the field concentration was attractive to leafhoppers. Our results indicate that the field background odour can interfere with a point-releasing attractant when their components overlap, and that a successful attractant must differ from the field background odour. PMID:28150728

Investigation of the interaction between benzaldehyde thiosemicarbazone compounds and xanthine oxidase

NASA Astrophysics Data System (ADS)

Li, Mengrong; Yu, Yanying; Liu, Jing; Chen, Zelu; Cao, Shuwen

2018-05-01

A series of substituted benzaldehyde thiosemicarbazide compounds (1-7) were synthesized as xanthine oxidase (XO) inhibitors, and the interactions between substituted benzaldehyde thiosemicarbazide compounds (1-7) and XO were studied by ultraviolet spectroscopy, fluorescence spectroscopy, and molecular docking. It was found that the hydrogen bond and hydrophobicity were the main interactions between substituted benzaldehyde thiosemicarbazide compounds and XO, and introducing sbnd OH at the para position of the benzene ring and a Ph- or Me-group at the amino terminal of compound 4 increased the modifier's inhibitory activity. The results suggest that the newly introduced benzene ring interacted with the hydrophobic cavity of XO by means of the π-π stacking force between the newly introduced benzene ring and the aromatic amino acid residues, such as the Phe residue, which greatly increased the modifier's inhibitory activity. We conclude that introducing the Ph-group at the amino terminal of compound 4 and the sbnd OH group at the para position of the benzene ring was a good route to obtain novel XO inhibitors. Fluorescence spectroscopy assisted by 8-anilino-1-naphthalenesulfonic acid fluorescence probing and molecular docking were helpful for achieving a preliminary and relatively clear understanding of the interactions between target compounds and XO, which deserve further study.

Solvo-thermal synthesis of a unique alkaline earth-transition Ba-Cd micro-porous coordination framework as hetero-metallic luminescent sensor for Cu2+ and real-time detection of benzaldehyde.

PubMed

Ding, Bin; Ma, Dian Xue; Zhang, Hui Min; Meng, Xin; Qiu, Rong Rong; Ren, Rong; Wu, Jie; Wu, Xiang Xia; Huo, Jian Zhong; Liu, Yuan Yuan; Shi, Xue Fang

2018-06-15

In this work a unique hetero-metallic alkaline earth-transition Ba-Cd luminescent micro-porous metal-organic framework {[BaCd(μ 6 -tp) 1.5 (μ 2 -Cl)(H 2 O) (DMF) 2 ]·0.75H 2 O} n (H 2 tp=terephthalic acid) (1) has been prepared under solvo-thermal conditions. In 1 infinite 1D {Ba-X-Cd} (X=O, Cl) inorganic chains are linked via these full de-pronated tp 2- ligands forming a unique 3D I 1 O 2 type micro-porous coordination framework. PXRD patterns of 1 have been determined confirming pure phases of 1. Luminescence investigations suggested that 1 exhibits highly selective and sensitive sensing for trace amounts of benzaldehyde in ethanol, which provides a facile method for real-time detection of benzaldehyde. Meanwhile 1 also exhibits highly selective and sensitive sensing for Cu 2+ over other cations with high quenching efficiency K sv value 1.15×10 4 L·mol -1 . As far as we know, 1 represents the first example of alkaline earth-transition hetero-metallic Ba-Cd micro-porous coordination framework as bi-functional luminescent probes for Cu 2+ and benzaldehyde. Copyright © 2018 Elsevier B.V. All rights reserved.

A novel series of IKKβ inhibitors part I: Initial SAR studies of a HTS hit.

PubMed

Cushing, Timothy D; Baichwal, Vijay; Berry, Karen; Billedeau, Roland; Bordunov, Viola; Broka, Chris; Cardozo, Mario; Cheng, Peng; Clark, David; Dalrymple, Stacie; DeGraffenreid, Michael; Gill, Adrian; Hao, Xiaolin; Hawley, Ronald C; He, Xiao; Jaen, Juan C; Labadie, Sharada S; Labelle, Marc; Lehel, Csaba; Lu, Pu-Ping; McIntosh, Joel; Miao, Shichang; Parast, Camran; Shin, Youngsook; Sjogren, Eric B; Smith, Marie-Louise; Talamas, Francisco X; Tonn, George; Walker, Keith M; Walker, Nigel P C; Wesche, Holger; Whitehead, Chris; Wright, Matt; Browner, Michelle F

2011-01-01

A novel series of (E)-1-((2-(1-methyl-1H-imidazol-5-yl) quinolin-4-yl) methylene) thiosemicarbazides was discovered as potent inhibitors of IKKβ. In this Letter we document our early efforts at optimization of the quinoline core, the imidazole and the semithiocarbazone moiety. Most potency gains came from substitution around the 6- and 7-positions of the quinoline ring. Replacement of the semithiocarbazone with a semicarbazone decreased potency but led to some measurable exposure. Copyright © 2010 Elsevier Ltd. All rights reserved.

Amino acid-based dithiazines: synthesis and photofragmentation of their benzaldehyde adducts.

PubMed

Kurchan, Alexei N; Kutateladze, Andrei G

2002-11-14

Alpha-amino acids and GABA are functionalized with dithiazine rings via reaction with sodium hydrosulfide in aqueous formaldehyde. The resulting dithiazines are lithiated at -78 degrees C and reacted with benzaldehyde furnishing amino acid-based 2,5-bis-substituted dithiazines. These adducts undergo externally sensitized photofragmentation with quantum efficiency comparable to that of the parent dithiane adducts, thus offering a novel approach to amino acid-based photolabile tethers. [reaction: see text

Effects of hydroxylated benzaldehyde derivatives on radiation-induced reactions involving various organic radicals

NASA Astrophysics Data System (ADS)

Ksendzova, G. A.; Samovich, S. N.; Sorokin, V. L.; Shadyro, O. I.

2018-05-01

In the present paper, the effects of hydroxylated benzaldehyde derivatives and gossypol - the known natural occurring compound - on formation of decomposition products resulting from radiolysis of ethanol and hexane in deaerated and oxygenated solutions were studied. The obtained data enabled the authors to make conclusions about the effects produced by the structure of the compounds under study on their reactivity towards oxygen- and carbon-centered radicals. It has been found that 2,3-dihydroxybenzaldehyde, 4,6-di-tert-butyl-2,3-dihydroxybenzaldehyde and 4,6-di-tert-butyl-3-(1,3-dioxane-2-yl)-1,2-dihydroxybenzene are not inferior in efficiency to butylated hydroxytoluene - the industrial antioxidant - as regards suppression of the radiation-induced oxidation processes occurring in hexane. The derivatives of hydroxylated benzaldehydes were shown to have a significant influence on radiation-induced reactions involving α-hydroxyalkyl radicals.

Product selectivity control induced by using liquid-liquid parallel laminar flow in a microreactor.

PubMed

Amemiya, Fumihiro; Matsumoto, Hideyuki; Fuse, Keishi; Kashiwagi, Tsuneo; Kuroda, Chiaki; Fuchigami, Toshio; Atobe, Mahito

2011-06-07

Product selectivity control based on a liquid-liquid parallel laminar flow has been successfully demonstrated by using a microreactor. Our electrochemical microreactor system enables regioselective cross-coupling reaction of aldehyde with allylic chloride via chemoselective cathodic reduction of substrate by the combined use of suitable flow mode and corresponding cathode material. The formation of liquid-liquid parallel laminar flow in the microreactor was supported by the estimation of benzaldehyde diffusion coefficient and computational fluid dynamics simulation. The diffusion coefficient for benzaldehyde in Bu(4)NClO(4)-HMPA medium was determined to be 1.32 × 10(-7) cm(2) s(-1) by electrochemical measurements, and the flow simulation using this value revealed the formation of clear concentration gradient of benzaldehyde in the microreactor channel over a specific channel length. In addition, the necessity of the liquid-liquid parallel laminar flow was confirmed by flow mode experiments.

Synthesis, spectroscopic (FT-IR, FT-Raman, UV and NMR) and computational studies on 3t-pentyl-2r,6c-diphenylpiperidin-4-one semicarbazone

NASA Astrophysics Data System (ADS)

Arockia doss, M.; Savithiri, S.; Rajarajan, G.; Thanikachalam, V.; Saleem, H.

2015-09-01

The structural and spectroscopic studies of 3t-pentyl-2r,6c-diphenylpiperidin-4-one semicarbazone (PDPOSC) were made by adopting B3LYP/HF levels theory using 6-311++G(d,p) basis set. The FT-IR and Raman spectra were recorded in solid phase, the fundamental vibrations were assigned on the basis of the total energy distribution (TED) of the vibrational modes, calculated with scaled quantum mechanics (SQM) method and PQS program. DFT method indicates that B3LYP is superior to HF method for molecular vibrational analysis. UV-vis spectrum of the compound was recorded in different solvents in the region of 200-800 nm and the electronic properties such as excitation energies, oscillator strength, wavelengths, HOMO and LUMO energies were evaluated by time-dependent DFT (TD-DFT) approach. The polarizability and first order hyperpolarizability of the title molecule were calculated and interpreted. The hyperconjugative interaction energy (E(2)) and electron densities of donor (i) and acceptor (j) bonds were calculated using NBO analysis. In addition, MEP and atomic charges of carbon, nitrogen and oxygen were calculated using B3LYP/6-311++G(d,p) level theory. Moreover, thermodynamic properties of the title compound were calculated by B3LYP/HF, levels using 6-311++G(d,p) basis set. The 1H and 13C nuclear magnetic resonance (NMR) chemical shifts of the molecule were calculated by the gauge independent atomic orbital (GIAO) method and compared with experimental results.

Suitable combination of promoter and micellar catalyst for kilo fold rate acceleration on benzaldehyde to benzoic acid conversion in aqueous media at room temperature: a kinetic approach.

PubMed

Ghosh, Aniruddha; Saha, Rumpa; Ghosh, Sumanta K; Mukherjee, Kakali; Saha, Bidyut

2013-05-15

The kinetics of oxidation of benzaldehyde by chromic acid in aqueous and aqueous surfactant (sodium dodecyl sulfate, SDS, alkyl phenyl polyethylene glycol, Triton X-100 and N-cetylpyridinium chloride, CPC) media have been investigated in the presence of promoter at 303 K. The pseudo-first-order rate constants (kobs) were determined from a logarithmic plot of absorbance as a function time. The rate constants were found to increase with introduction of heteroaromatic nitrogen base promoters such as Picolinic acid (PA), 2,2'-bipyridine (bipy) and 1,10-phenanthroline (phen). The product benzoic acid has been characterized by conventional melting point experiment, NMR, HRMS and FTIR spectral analysis. The mechanism of both unpromoted and promoted reaction path has been proposed for the reaction. In presence of the anionic surfactant SDS, cationic surfactant CPC and neutral surfactant TX-100 the reaction can undergo simultaneously in both aqueous and micellar phase with an enhanced rate of oxidation in the micellar phase. Both SDS and TX-100 produce normal micellar effect whereas CPC produce reverse micellar effect in the presence of benzaldehyde. The observed net enhancement of rate effects has been explained by considering the hydrophobic and electrostatic interaction between the surfactants and reactants. SDS and bipy combination is the suitable one for benzaldehyde oxidation. Copyright © 2013 Elsevier B.V. All rights reserved.

Intermolecular interaction of thiosemicarbazone derivatives to solvents and a potential Aedes aegypti target

NASA Astrophysics Data System (ADS)

da Silva, João Bosco P.; Hallwass, Fernando; da Silva, Aluizio G.; Moreira, Diogo Rodrigo; Ramos, Mozart N.; Espíndola, José Wanderlan P.; de Oliveira, Ana Daura T.; Brondani, Dalci José; Leite, Ana Cristina L.; Merz, Kenneth M.

2015-08-01

DFT calculations were used to access information about structure, energy and electronic properties of series of phenyl- and phenoxymethyl-(thio)semicarbazone derivatives with demonstrated activity against the larvae of Aedes aegypti in stage L4. The way as the thiosemicarbazone derivatives can interact with solvents like DMSO and water were analyzed from the comparison between calculated and experimental 1H NMR chemical shifts. The evidences of thiosemicarbazone derivatives making H-bond interaction to solvent have provide us insights on how they can interact with a potential A. aegypti's biological target, the Sterol Carrier Protein-2.

Determination of some aldehydes by using solid-phase microextraction and high-performance liquid chromatography with UV detection.

PubMed

Kumar, Ashwini; Singh, Baldev; Malik, Ashok Kumar; Tiwary, Dhananjay K

2007-01-01

A new approach has been developed for the extraction and determination of aldehydes such as veratraldehyde, m-nitrobenzaldehyde, cinnamaldehyde, benzaldehyde, and p-chlorobenzaldehyde by using solid-phase microextraction (SPME) and high-performance liquid chromatography with UV detection (HPLC/UV). The method involves adsorption of the aldehydes on polydimethylsiloxane/divinylbenzene-coated fiber, followed by desorption in the desorption chamber of the SPME-HPLC interface, using acetonitrile-water (70 + 30) as the mobile phase; UV detection was at 254 nm. A good separation of 5 aldehydes was obtained on a C18 column. The detection limits of veratraldehyde, m-nitrobenzaldehyde, cinnamaldehyde, benzaldehyde, and p-chlorobenzaldehyde are 25, 41, 13, 12, and 11 pg/mL, respectively, which are about 100 times better than the detection limits for other SPME methods using gas chromatography. The proposed method was validated by determining benzaldehyde in bitter almonds and cinnamaldehyde in cinnamon bark. The recoveries of the 5 analytes were determined by analysis of spiked drinking water.

Interactions of flavoured oil in-water emulsions with polylactide.

PubMed

Salazar, Rómulo; Domenek, Sandra; Ducruet, Violette

2014-04-01

Polylactide (PLA), a biobased polymer, might prove suitable as eco-friendly packaging, if it proves efficient at maintaining food quality. To assess interactions between PLA and food, an oïl in-water model emulsion was formulated containing aroma compounds representing different chemical structure classes (ethyl esters, 2-nonanone, benzaldehyde) at a concentration typically found in foodstuff (100 ppm). To study non-equilibrium effects during food shelf life, the emulsions were stored in a PLA pack (tray and lid). To assess equilibrium effects, PLA was conditioned in vapour contact with the aroma compounds at concentrations comparable to headspace conditions of real foods. PLA/emulsion interactions showed minor oil and aroma compound sorption in the packaging. Among tested aroma compounds, benzaldehyde and ethyl acetate were most sorbed and preferentially into the lid through the emulsion headspace. Equilibrium effects showed synergy of ethyl acetate and benzaldehyde, favouring sorption of additional aroma compounds in PLA. This should be anticipated during the formulation of food products. Copyright © 2013 Elsevier Ltd. All rights reserved.

Mechanism insight into the cyanide-catalyzed benzoin condensation: a density functional theory study.

PubMed

He, Yunqing; Xue, Ying

2010-09-02

The reaction mechanism of the cyanide-catalyzed benzoin condensation without protonic solvent assistance has been studied computationally for the first time employing the density functional theory (B3LYP) method in conjunction with 6-31+G(d,p) basis set. Four possible pathways have been investigated. A new proposed pathway on the basis of the Lapworth mechanism is determined to be the dominant pathway in aprotic solvent, in which the formation of the Lapworth's cyanohydrin intermediate is a sequence including three steps assisted by benzaldehyde, clearly manifesting that the reaction can take place in aprotic solvents such as DMSO. In this favorable pathway with six possible transition states located along the potential energy surface, the reaction of the cyanide/benzaldehyde complex with another benzaldehyde to afford an alpha-hydroxy ether is the rate-determining dynamically with the activation free energy barrier of 26.9 kcal/mol, and the step to form cyanohydrin intermediate from alpha-hydroxy ether is partially rate-determining for its relatively significant barrier 20.0 kcal/mol.

Selective liquid phase oxidation of benzyl alcohol to benzaldehyde by tert-butyl hydroperoxide over γ-Al2O3 supported copper and gold nanoparticles

NASA Astrophysics Data System (ADS)

Ndolomingo, Matumuene Joe; Meijboom, Reinout

2017-03-01

Benzyl alcohol oxidation to benzaldehyde was performed by tert-butyl hydroperoxide (TBHP) in the absence of any solvent using γ-Al2O3 supported copper and gold nanoparticles. Li2O and ionic liquids were used as additive and stabilizers for the synthesis of the catalysts. The physico-chemical properties of the catalysts were characterized by atomic absorption spectroscopy (AAS), X-ray diffraction spectroscopy (XRD), N2 absorption/desorption (BET), transmission electron microscopy (TEM), scanning electron microscopy (SEM), thermogravimetric analysis (TGA) and temperature programmed reduction (TPR), whereas, the oxidation reaction was followed by gas chromatography with a flame ionization detector (GC-FID). The as prepared catalysts exhibited good catalytic performance in terms of conversion and selectivity towards benzaldehyde. The performance of the Au-based catalysts is significantly higher than that of the Cu-based catalysts. For both Cu and Au catalysts, the conversion of benzyl alcohol increased as the reaction proceeds, while the selectivity for benzaldehyde decreased. Moreover, the catalysts can be easily recycled and reused with neither significant loss of activity nor selectivity. A kinetic study for the Cu and Au-catalyzed oxidation of benzyl alcohol to benzyldehyde is reported. The rate at which the oxidation of benzyl alcohol is occurring as a function of catalyst and oxidant amounts was investigated, with the apparent rate constant, kapp being proportional to the amount of nano catalyst and oxygen present in the system.

Study of excess dielectric properties and Kirkwood correlation parameter of binary mixtures of benzaldehyde and methanol at different temperatures

NASA Astrophysics Data System (ADS)

Shah, N. S.; Vankar, H. P.; Rana, V. A.

2018-05-01

Static permittivity (ɛ0) and permittivity at optical frequency (ɛ∞) of the Benzaldehyde (BZ), Methanol (MeOH) and their binary mixtures were measured in the temperature range from 293.15 K to 323.15 K (in the interval of 10 K). From the ɛ0 and ɛ∞ other parameters such as effective Kirkwood correlation factor (geff), corrective Kirkwood correction factor (gf), Bruggman factor (fB), excess permittivity (ɛ0E ) and permittivity at optical frequency (ɛ∞E ) were evaluated.

Initial reactions involved in the dissimilation of mandelate by Rhodotorula graminis.

PubMed Central

Durham, D R

1984-01-01

Rhodotorula graminis utilized DL-mandelate, L(+)-mandelate, and D(-)-mandelate as sole sources of carbon and energy. Growth on these aromatic substrates resulted in the induction of an NAD-dependent D(-)-mandelate dehydrogenase and a dye-linked L(+)-mandelate dehydrogenase, each catalyzing the stereospecific conversion of its respective enantiomer of mandelate to benzoylformate. Benzoylformate was oxidized to benzaldehyde, which was dehydrogenated to benzoate by an NAD-dependent benzaldehyde dehydrogenase. Benzoate was further metabolized through p-hydroxybenzoate and the protocatechuate branch of the beta-ketoadipate pathway. PMID:6389497

Computational studies on nonlinear optical property of novel Wittig-based Schiff-base ligands and copper(II) complex

NASA Astrophysics Data System (ADS)

Rajasekhar, Bathula; Patowary, Nidarshana; K. Z., Danish; Swu, Toka

2018-07-01

Hundred and forty-five novel molecules of Wittig-based Schiff-base (WSB), including copper(II) complex and precursors, were computationally screened for nonlinear optical (NLO) properties. WSB ligands were derived from various categories of amines and aldehydes. Wittig-based precursor aldehydes, (E)-2-hydroxy-5-(4-nitrostyryl)benzaldehyde (f) and 2-hydroxy-5-((1Z,3E)-4-phenylbuta-1,3-dien-1-yl) benzaldehyde (g) were synthesised and spectroscopically confirmed. Schiff-base ligands and copper(II) complex were designed, optimised and their NLO property was studied using GAUSSIAN09 computer program. For both optimisation and hyperpolarisability (finite-field approach) calculations, Density Functional Theory (DFT)-based B3LYP method was applied with LANL2DZ basis set for metal ion and 6-31G* basis set for C, H, N, O and Cl atoms. This is the first report to present the structure-activity relationship between hyperpolarisability (β) and WSB ligands containing mono imine group. The study reveals that Schiff-base ligands of the category N-2, which are the ones derived from the precursor aldehyde, 2-hydroxy-5-(4nitro-styryl)benzaldehyde and pre-polarised WSB coordinated with Cu(II), encoded as Complex-1 (β = 14.671 × 10-30 e.s.u) showed higher β values over other categories, N-1 and N-3, i.e. WSB derived from precursor aldehydes, 2-hydroxy-5-styrylbenzaldehyde and 2-hydroxy-5-((1Z,3E)-4-phenylbuta-1,3-dien-1-yl)benzaldehyde, respectively. For the first time here we report the geometrical isomeric effect on β value.

A nanoporous 3D zinc(II) metal–organic framework for selective absorption of benzaldehyde and formaldehyde

DOE Office of Scientific and Technical Information (OSTI.GOV)

Moradpour, Tahereh; Abbasi, Alireza, E-mail: aabbassi@khayam.ut.ac.ir; Van Hecke, Kristof

A new 3D nanoporous metal–organic framework (MOF), [[Zn{sub 4}O(C{sub 24}H{sub 15}N{sub 6}O{sub 6}){sub 2}(H{sub 2}O){sub 2}]·6H{sub 2}O·DMF]{sub n} (1) based on 4,4′,4″-s-triazine-1,3,5-triyltri-p-aminobenzoate (TATAB) ligand was solvothermally synthesized and characterized by single–crystal X-ray diffraction, Powder X-ray diffraction (PXRD), infrared spectroscopy (IR) and Brunauer–Emmett–Teller (BET) analyses. X-ray single crystal diffraction analysis reveals that 1 exhibits a 3D network with new kvh1 topology. Semi-empirical (AM1) calculations were carried out to obtain stable conformers for TATAB ligand. In addition, the absorption of two typical aldehydes (benzaldehyde and formaldehyde) in the presence of 1 was investigated and the effect of the aldehyde concentration, exposure timemore » and temperature was studied. It was found that compound 1 has a potential for the absorption of aldehydes under mild conditions. - Graphical abstract: Absorption of two typical aldehydes (formaldehyde and benzaldehyde) by solvothermally synthesized of a 3D nano-porous MOF based on TATAB tricarboxylate ligand and Zn (NO{sub 3}){sub 2}·6H{sub 2}O. - Highlights: • We present a 3D Zn(II)-MOF with TATAB linker by solvothermal method. • The framework possesses a new kvh1 topology. • The framework displays formaldehyde and benzaldehyde absorption property. • Conformational analysis was performed to determine the stable linker geometry.« less

Fluorometric detection of nitroaromatics by fluorescent lead complexes: A spectroscopic assessment of detection mechanism

NASA Astrophysics Data System (ADS)

Chattopadhyay, Tanmay; Chatterjee, Sourav; Majumder, Ishani; Ghosh, Soumen; Yoon, Sangee; Sim, Eunji

2018-04-01

Three Schiff base ligands such as 2-[(2-Hydroxy-3-methoxy-benzylidene)-amino]-2-hydroxymethyl-propane-1,3-diol (HL1), 2-[(2-Hydroxy-benzylidene)-amino]-2-hydroxymethyl-propane-1,3-diol (HL2), 2-[(3,5-Dichloro-2-hydroxy-benzylidene)-amino]-2-hydroxymethyl-propane-1,3-diol (HL3) have been synthesized by condensation of aldehydes (such as 3,5-Dichloro-2-hydroxy benzaldehyde, 2-Hydroxy-benzaldehyde, and 2-Hydroxy-3-methoxy-benzaldehyde) with Tris-(hydroxymethyl)amino methane and characterized by IR, UV-vis and 1H NMR spectroscopy. Then all these three ligands have been used to prepare Pb(II) complexes by reaction with lead(II) acetate tri-hydrate in methanol. In view of analytical and spectral (IR, UV-vis and Mass) studies, it has been concluded that, except HL2, other two ligands form 1:1 metal complexes (1 and 3) with lead. Between two complexes, complex 3 is highly fluorescent and this property has been used to identify the pollutant nitroaromatics. Finally, the quenching mechanism has been established by means of spectroscopic investigation.

Evaluation of the hydroxynitrile lyase activity in cell cultures of capulin (Prunus serotina).

PubMed

Hernández, Liliana; Luna, Héctor; Navarro-Ocaña, Arturo; Olivera-Flores, Ma Teresa de Jesús; Ayala, Ivon

2008-07-01

Enzymatic preparations obtained from young plants and cell cultures of capulin were screened for hydroxynitrile lyase activity. The three week old plants, grown under sterile conditions, were used to establish a solid cell culture. Crude preparations obtained from this plant material were evaluated for the transformation of benzaldehyde to the corresponding cyanohydrin (mandelonitrile). The results show that the crude material from roots, stalks, and leaves of young plants and calli of roots, stalks, internodes and petioles biocatalyzed the addition of hydrogen cyanide (HCN) to benzaldehyde with a modest to excellent enantioselectivity.

Sonochemical synthesis of a multi-responsive regenerable water-stable zinc(II) fluorescent probe for highly selective, sensitive and real-time sensing of benzaldehyde, ferric ion and PH.

PubMed

Wang, Xin Rui; Wang, Xing Ze; Li, Yong; Liu, Kun; Liu, Shi Xin; Du, Jing; Huang, Zhuo; Luo, Yan; Huo, Jian Zhong; Wu, Xiang Xia; Liu, Yuan Yuan; Ding, Bin

2018-06-01

In this work, a novel water-stable coordination polymer with {4 4 } network topology {[Zn(L) 2 (NO 3 ) 2 ]} n (1) (L = 4,4'-Bis(triazol-1-ylmethyl)biphenyl) has been synthesized through the hydrothermal and sonochemical approaches. 1 has been characterized by single crystal X-ray diffraction, powder X-ray diffraction (PXRD), Fourier Transform Infrared Spectroscopy, UV-vis absorption spectrum and scanning electron microscopy (SEM). PXRD patterns of the as-synthesized samples 1 have confirmed the purity of the bulky samples. In the sonochemical preparation approaches, different ultrasound irradiation power and ultrasound time were also used in order to investigate the impact factor for morphology and size of nano-structured 1. Photo-luminescence studies have revealed that 1 can efficiently distinguish Fe 3+ from Fe 2+ and other metal ions. On the other hand, 1 also can exhibit a highly sensitive, excellently selective and real-time detection of benzaldehyde and pH through photo-luminescence quenching process. As for 1, density functional theory (DFT) and time-dependent DFT (TDDFT) theory has been applied to calculate these spectroscopic data, the result agree with the experimental results for detection of benzaldehyde. Photo-luminescent recyclability results indicated 1 can be reused at least five times in the detection process. To the best of our knowledge, this is the first example of a multi-responsive regenerable luminescent sensor for highly selective, sensitive and real-time sensing of Fe 3+ over Fe 2+ , benzaldehyde and pH values. Copyright © 2018 Elsevier B.V. All rights reserved.

Pestalols A-E, new alkenyl phenol and benzaldehyde derivatives from endophytic fungus Pestalotiopsis sp. AcBC2 isolated from the Chinese mangrove plant Aegiceras corniculatum.

PubMed

Sun, Jian-Fan; Lin, Xiuping; Zhou, Xue-Feng; Wan, Junting; Zhang, Tianyu; Yang, Bin; Yang, Xian-Wen; Tu, Zhengchao; Liu, Yonghong

2014-06-01

Five alkenyl phenol and benzaldehyde derivatives, pestalols A-E (1-5), as well as seven known compounds (6-12), were isolated from endophytic fungus Pestalotiopsis sp. AcBC2 derived from the Chinese mangrove plant Aegiceras corniculatum. Their structures were determined by spectroscopic analyses. Compounds 2 and 3 showed cytotoxicity against a panel of 10 tumor cell lines. Compounds 1-5, 8, 9, 11, and 12 showed inhibitory activities against Influenza A virus subtype (H3N2) and Swine Flu (H1N1) viruses. Compound 2 also showed inhibitory activity against tuberculosis.

Vibrational, NMR and UV-visible spectroscopic investigation and NLO studies on benzaldehyde thiosemicarbazone using computational calculations

NASA Astrophysics Data System (ADS)

Moorthy, N.; Prabakar, P. C. Jobe; Ramalingam, S.; Pandian, G. V.; Anbusrinivasan, P.

2016-04-01

In order to investigate the vibrational, electronic and NLO characteristics of the compound; benzaldehyde thiosemicarbazone (BTSC), the XRD, FT-IR, FT-Raman, NMR and UV-visible spectra were recorded and were analysed with the calculated spectra by using HF and B3LYP methods with 6-311++G(d,p) basis set. The XRD results revealed that the stabilized molecular systems were confined in orthorhombic unit cell system. The cause for the change of chemical and physical properties behind the compound has been discussed makes use of Mulliken charge levels and NBO in detail. The shift of molecular vibrational pattern by the fusing of ligand; thiosemicarbazone group with benzaldehyde has been keenly observed. The occurrence of in phase and out of phase molecular interaction over the frontier molecular orbitals was determined to evaluate the degeneracy of the electronic energy levels. The thermodynamical studies of the temperature region 100-1000 K to detect the thermal stabilization of the crystal phase of the compound were investigated. The NLO properties were evaluated by the determination of the polarizability and hyperpolarizability of the compound in crystal phase. The physical stabilization of the geometry of the compound has been explained by geometry deformation analysis.

Growth of 4-(dimethylamino) benzaldehyde doped triglycine sulphate single crystals and its characterization

NASA Astrophysics Data System (ADS)

Rai, Chitharanjan; Sreenivas, K.; Dharmaprakash, S. M.

2009-11-01

Single crystals of triglycine sulphate (TGS) doped with 1 mol% of 4-(dimethylamino) benzaldehyde (DB) have been grown from aqueous solution at ambient temperature by slow evaporation technique. The effect of dopant on the crystal growth and dielectric, pyroelectric and mechanical properties of TGS crystal have been investigated. X-ray powder diffraction pattern for pure and doped TGS was collected to determine the lattice parameters. FTIR spectra were employed to confirm the presence of 4-(dimethylamino) benzaldehyde in TGS crystal, qualitatively. The dielectric permittivity has been studied as a function of temperature by cooling the sample at a rate of 1 °C/min. An increase in the Curie temperature Tc=51 °C (for pure TGS, Tc=48.5 °C) and decrease in maximum permittivity has been observed for doped TGS when compared to pure TGS crystal. Pyroelectric studies on doped TGS were carried out to determine pyroelectric coefficient. The Vickers's hardness of the doped TGS crystals along (0 1 0) face is higher than that of pure TGS crystal for the same face. Domain patterns on b-cut plates were observed using scanning electron microscope. The low dielectric constant, higher pyroelectric coefficient and higher value of hardness suggest that doped TGS crystals could be a potential material for IR detectors.

Theoretical investigations on the mechanism of benzoin condensation catalyzed by pyrido[1,2-a]-2-ethyl[1,2,4]triazol-3-ylidene.

PubMed

He, Yunqing; Xue, Ying

2011-03-03

A new annulated N-heterocyclic carbene (NHC), pyrido[1,2-a]-2-ethyl[1,2,4]triazol-3-ylidene, has been synthesized and its good catalytic activity for benzoin condensation has been experimentally determined by You and co-workers recently [ Ma , Y. J. , Wei , S. P. , Lan , J. B. , Wang , J. Z. , Xie , R. G. , and You , J. S. J. Org. Chem. 2008 , 73 , 8256 ]. In this work, the mechanism of the title reaction has been intensively studied computationally by employing the density functional theory (B3LYP) method in conjunction with 6-31+G(d) and 6-311+G(2d,p) basis sets. Our results indicate that path A (in which a sequence of intermolecular proton transfers between two carbene/benzaldehyde coupling intermediates affords enamine) and path B (in which a t-BuOH assisted hydrogen transfer generates enamine) proposed on the basis of the Breslow mechanism are competitive for their similar barriers. In path A, the first intermolecular proton transfer between two N-heterocyclic carbene/benzaldehyde coupled intermediates to form tertiary alcohol and enolate anion is theoretically the rate-determining step with corresponding barrier (30.93 kcal/mol), while the t-BuOH assisted hydrogen transfer generating Breslow enamine is the rate-determining step with corresponding barrier (28.84 kcal/mol) in path B. The coupling of carbene and benzaldehyde, and the coupling of enamine and another benzaldehyde to form a C-C bond are partially rate-determining for their relatively significant barriers (24.06 and 26.95 kcal/mol, respectively), being the same in both paths A and B. Our results are in nice agreement with the experimental result in a kinetic investigation of thiazolium ion-catalyzed benzoin condensation performed by White and Leeper in 2001.

Computational study of the synthesis of benzoin derivatives from benzil

NASA Astrophysics Data System (ADS)

Topal, Kevser Göçmen; Unaleroglu, Canan; Aviyente, Viktorya

Benzil (1,2-diphenylethane-1,2-dione) undergoes cyanide catalyzed condensation with benzaldehyde to yield O-benzoylated benzoin (2-benzoyl-1,2-diphenylethanone). In this study, the experimentally suggested mechanism has been modeled with PM3 and verified with B3LYP. The effect of the substituent on the reaction yield has been rationalized by considering two benzil derivatives; 1,2-bis(2-chlorophenyl)ethane-1,2-dione and 1,2-bis(2-fluorophenyl)ethane-1,2-dione and three benzaldehyde derivatives; o-fluorobenzaldehyde, o-methylbenzaldehyde and 2-pyridinecarboxaldehyde. The effect of the solvent has been modeled by using the isodensity-surface polarizable continuum (IPCM) model. Reactivity descriptors have been used to justify the reactivity differences of the various substituents.

Charge transfer interactions and nonlinear optical properties of push pull chromophore benzaldehyde phenylhydrazone: A vibrational approach

NASA Astrophysics Data System (ADS)

Ravikumar, C.; Joe, I. Hubert; Jayakumar, V. S.

2008-07-01

FT Raman and IR spectra of the crystallized nonlinear optic (NLO) molecule, benzaldehyde phenylhydrazone (BPH) have been recorded and analyzed. The equilibrium geometry, bonding features and harmonic vibrational frequencies of BPH have been investigated with the help of B3LYP density functional theory (DFT) method. The assignments of the vibrational spectra have been carried out with the help of normal coordinate analysis (NCA) following the scaled quantum mechanical force field methodology (SQMFF). From the optimized geometry, the decrease in C-N bond length indicates the electron delocalization over the region of the molecule. The vibrational analysis confirm the charge transfer interaction between the phenyl rings through ≻Cdbnd N-N≺ skeleton.

Growth, structural, thermal, dielectric and optical studies on HBST crystal: A potential THz emitter

NASA Astrophysics Data System (ADS)

Ma, Yuzhe; Teng, Bing; Cao, Lifeng; Zhong, Degao; Ji, Shaohua; Teng, Fei; Liu, Jiaojiao; Yao, Yuan; Tang, Jie; Tong, Jiaming

2018-02-01

The efficient organic nonlinear optical material 4-hydroxy benzaldehyde-N-methyl 4-stilbazolium tosylate (HBST) was grown from methanol by slope nucleation method combined with slow cooling (SNM-SC) for the first time. The optimum growth conditions based on the cooling rate was further investigated. The single crystal X-ray diffraction (XRD) revealed that the chromophores of HBST crystal make an angle of about 33° with respect to the a-axis, which is close to the optimum of Terahertz (THz)-wave generation and electro-optics applications. NMR and FT-IR spectral studies have been performed to ascertain various functional groups present in the sample. Futhermore, the thermal stability and decomposition stages were analyzed through TG-DTA and DSC techniques. The dielectric constant and dielectric loss of HBST crystal have been studied. Critical optical properties like the absorption coefficient, refractive index, cut-off wavelength and band gap energy were calculated. Photoluminescence (PL) exication studies indicated green emission occured at 507 nm. All the results of HBST crystal make it a promising candidate in the fields of optoelectronic and the generation of THz.

Co-exposure with fullerene may strengthen health effects of organic industrial chemicals.

PubMed

Lehto, Maili; Karilainen, Topi; Róg, Tomasz; Cramariuc, Oana; Vanhala, Esa; Tornaeus, Jarkko; Taberman, Helena; Jänis, Janne; Alenius, Harri; Vattulainen, Ilpo; Laine, Olli

2014-01-01

In vitro toxicological studies together with atomistic molecular dynamics simulations show that occupational co-exposure with C60 fullerene may strengthen the health effects of organic industrial chemicals. The chemicals studied are acetophenone, benzaldehyde, benzyl alcohol, m-cresol, and toluene which can be used with fullerene as reagents or solvents in industrial processes. Potential co-exposure scenarios include a fullerene dust and organic chemical vapor, or a fullerene solution aerosolized in workplace air. Unfiltered and filtered mixtures of C60 and organic chemicals represent different co-exposure scenarios in in vitro studies where acute cytotoxicity and immunotoxicity of C60 and organic chemicals are tested together and alone by using human THP-1-derived macrophages. Statistically significant co-effects are observed for an unfiltered mixture of benzaldehyde and C60 that is more cytotoxic than benzaldehyde alone, and for a filtered mixture of m-cresol and C60 that is slightly less cytotoxic than m-cresol. Hydrophobicity of chemicals correlates with co-effects when secretion of pro-inflammatory cytokines IL-1β and TNF-α is considered. Complementary atomistic molecular dynamics simulations reveal that C60 co-aggregates with all chemicals in aqueous environment. Stable aggregates have a fullerene-rich core and a chemical-rich surface layer, and while essentially all C60 molecules aggregate together, a portion of organic molecules remains in water.

Synthesis, spectral and antimicrobial activity of Zn(II) complexes with Schiff bases derived from 2-hydrazino-5-[substituted phenyl]-1,3,4-thiadiazole and benzaldehyde/2-hydroxyacetophenone/indoline-2,3-dione

NASA Astrophysics Data System (ADS)

Singh, Ajay K.; Pandey, O. P.; Sengupta, S. K.

2013-09-01

Zn(II) complexes have been synthesized by reacting zinc acetate with Schiff bases derived from 2-hydrazino-5-[substituted phenyl]-1,3,4-thiadiazole and 2-hydroxyacetophenone/benzaldehyde/indoline-2,3-dione. All these complexes are soluble in DMF and DMSO; low molar conductance values indicate that they are non electrolytes. Elemental analyses suggest that the complexes have 1:2 metal to ligands stoichiometry of the types [ZnL2(H2O)2](L = monoanionic Schiff bases derived from 2-hydrazino-5-[substituted phenyl]-1,3,4-thiadiazole and 2-hydroxyacetophenone/indoline-2,3-dione) [ZnL2‧(OOCCH3)2(H2O)2](L‧ = neutral Schiff bases derived from 2-hydrazino-5-[substituted phenyl]-1,3,4-thiadiazole and benzaldehyde), and they were characterized by IR, 1H NMR, and 13C NMR. Particle sizes of synthesized compounds were measured with dynamic light scattering (DLS) analyser which indicates that particle diameter are of the range ca. 100-200 nm. All these Schiff bases and their complexes have also been screened for their antibacterial (Bacillus subtilis (B. subtilis), Escherichia coli (E. coli) and antifungal activities (Colletotrichum falcatum (C. falcatum), Aspergillus niger (A. niger), Fusarium oxysporium (F. oxysporium) Curvularia pallescence (C. pallescence). The antimicrobial activities have shown that upon complexation the activity increases.

Comparative studies of structural, thermal, optical, and electrochemical properties of azines with different end groups with their azomethine analogues toward application in (opto)electronics.

PubMed

Sek, Danuta; Siwy, Mariola; Bijak, Katarzyna; Grucela-Zajac, Marzena; Malecki, Grzegorz; Smolarek, Karolina; Bujak, Lukasz; Mackowski, Sebastian; Schab-Balcerzak, Ewa

2013-10-10

Two series of azines and their azomethine analogues were prepared via condensation reaction of benzaldehyde, 2-hydroxybenzaldehyde, 4-pyridinecarboxaldehyde, 2-thiophenecarboxaldehyde, and 4-(diphenylamino)benzaldehyde with hydrazine monohydrate and 1,4-phenylenediamine, respectively. The structures of given compounds were characterized by FTIR, (1)H NMR, and (13)C NMR spectroscopy as well as elemental analysis. Optical, electrochemical, and thermal properties of all compounds were investigated by means of differential scanning calorimetry (DSC), UV-vis spectroscopy, stationary and time-resolved photoluminescence spectroscopy, and cycling voltammetry (CV). Additionally, the electronic properties, that is, orbital energies and resulting energy gap were calculated theoretically by density functional theory (DFT). Influence of chemical structure of the compounds on their properties was analyzed.

A Grignard-like Organic Reaction in Water

NASA Astrophysics Data System (ADS)

Breton, Gary W.; Hughey, Christine A.

1998-01-01

The addition of a Grignard reagent to a carbonyl-containing compound to form an alcohol is an important reaction to demonstrate in organic chemistry laboratory courses. However, the reaction presents several practical problems for the lab instructor including the need for anhydrous solvents (e.g., ether), dry glassware, and the occasional problem of slow reaction initiation. We have scaled, and tested, a known Grignard-like reaction between allyl bromide and benzaldehyde mediated by zinc metal in aqueous media. The procedure retains the desirable features of the traditional Grignard reaction, while eliminating some of the commonly encountered difficulties. Thus, addition of allyl bromide (1.2 eq) to benzaldehyde and zinc in a two-phase mixture of THF and saturated aqueous NH4Cl afforded addition product 1-phenyl-3-buten-1-ol in 70-85% yields.

4-{2-[2-(4-Formyl-phen-oxy)eth-oxy]eth-oxy}benzaldehyde.

PubMed

Ma, Zhen; Cao, Yiqun

2011-06-01

The title compound, C(18)H(18)O(5), was obtained by the reaction of 4-hy-droxy-benzaldehyde with bis-(2,2-dichloro-eth-yl) ether in dimethyl-formamide. In the crystal, the mol-ecule lies on a twofold rotation axis that passes through the central O atom of the aliphatic chain, thus leading to one half-mol-ecule being present per asymmetric unit. The carbonyl, aryl and O-CH(2)-CH(2) groups are almost coplanar, with an r.m.s. deviation of 0.030 Å. The aromatic rings are approximately perpendicular to each other, forming a dihedral angle of 78.31 sh;H⋯O hydrogen bonds and C-H⋯π inter-actions help to consolidate the three-dimensional network.

Electronic excitation energies, three-state intersections, and photodissociation mechanisms of benzaldehyde and acetophenone

NASA Astrophysics Data System (ADS)

Cui, Ganglong; Lu, You; Thiel, Walter

2012-06-01

We report a theoretical study on the electronically excited states and the mechanisms of photodissociation of C6H5CHO and C6H5COCH3. For both molecules, we find an S1/T2/T1 three-state intersection region, which allows for an efficient S1 → T1 intersystem crossing via the T2 state that acts as a relay. Consequently, T1 reactions become the major radical photodissociation channels. According to the computed energy profiles, T1 photodissociation mainly yields phenyl and formyl radicals in the case of benzaldehyde, and benzoyl and methyl radicals in the case of acetophenone, with different C-C bonds being cleaved preferentially. The computational results agree well with the available experimental data.

Active-Site Engineering of Benzaldehyde Lyase Shows That a Point Mutation Can Confer Both New Reactivity and Susceptibility to Mechanism-Based Inhibition

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brandt, Gabriel S.; Kneen, Malea M.; Petsko, Gregory A.

2010-02-11

Benzaldehyde lyase (BAL) from Pseudomonas putida is a thiamin diphosphate (ThDP)-dependent enzyme that catalyzes the breakdown of (R)-benzoin. Here we report that a point mutant, BAL A28S, not only catalyzes the decarboxylation of benzoylformate but, like benzoylformate decarboxylase (BFDC), is also inactivated by the benzoylformate analogues methyl benzoylphosphonate (MBP) and benzoylphosphonate (BP). The latter has no effect on wild-type BAL, and the inactivation of the A28S variant is shown to result from phosphorylation of the newly introduced serine residue. This lends support to the proposal that an appropriately placed nucleophile facilitates the expulsion of carbon dioxide from the active sitemore » in many ThDP-dependent decarboxylases.« less

Comparison of sampling methods for radiocarbon dating of carbonyls in air samples via accelerator mass spectrometry

NASA Astrophysics Data System (ADS)

Schindler, Matthias; Kretschmer, Wolfgang; Scharf, Andreas; Tschekalinskij, Alexander

2016-05-01

Three new methods to sample and prepare various carbonyl compounds for radiocarbon measurements were developed and tested. Two of these procedures utilized the Strecker synthetic method to form amino acids from carbonyl compounds with either sodium cyanide or trimethylsilyl cyanide. The third procedure used semicarbazide to form crystalline carbazones with the carbonyl compounds. The resulting amino acids and semicarbazones were then separated and purified using thin layer chromatography. The separated compounds were then combusted to CO2 and reduced to graphite to determine 14C content by accelerator mass spectrometry (AMS). All of these methods were also compared with the standard carbonyl compound sampling method wherein a compound is derivatized with 2,4-dinitrophenylhydrazine and then separated by high-performance liquid chromatography (HPLC).

Effects of structures of bidentate Schiff base type bonded-ligands derived from benzaldehyde on the photoluminescence performance of polymer-rare earth complexes.

PubMed

Gao, Baojiao; Zhang, Liqin; Zhang, Dandan

2018-02-07

Two kinds of bidentate Schiff base ligands derived from benzaldehyde, benzaldehyde/m-aminophenol (BAMA) type and benzaldehyde/glutamic acid (BAGL) type ligands, were synchronously synthesized and bonded on the backbone of polysulfone (PSF) through molecular design and by polymer reactions, and two functional polymers, PSF-BAMA and PSF-BAGL, were obtained. Then two series of novel luminescent Schiff base-type polymer-rare earth complexes were prepared via coordination reactions. In this work, the effects of the structures of the bonded ligands on the photoluminescence performance of the complexes were investigated in detail, and for the different photophysical properties of the prepared complexes, relevant theoretical explanations were given. The experimental results show that the bonded ligand BAMA can strongly sensitize the fluorescence emission of Eu(iii) ions, and the binary complex PSF-(BAMA) 3 -Eu(iii) emits strong red fluorescence under UV light. The reason for this lies in the fact that a larger conjugate π-bond system is contained in the structure of BAMA, and so the triplet state of BAMA can be matched with the resonant energy level of the Eu(iii) ion. While the bonded ligand BAGL can effectively sensitize the fluorescence emission of Tb(iii) ions, the binary complex PSF-(BAGL) 3 -Tb(iii) exhibits very strong green fluorescence under UV light. The reason is that a smaller conjugate π-bond system is contained in the structure of BAGL and there is a good energy level matching between the triplet state of BAGL and the resonant energy level of the Tb(iii) ion. The fluorescence intensities of the two ternary complexes, PSF-(BAMA) 3 -Eu(iii)-(Phen) 1 (phenanthroline, Phen) and PSF-(BAGL) 3 -Tb(iii)-(Phen) 1 , are much stronger than that of the corresponding binary complex because Phen as the second ligand has two effects, the effect of synergistic coordination with the first ligand and the effect of replacing the coordinated water around the central ion, and it has been confirmed by fluorescence spectroscopy and thermogravimetric analysis.

Kinetics of the benzyl + O(3P) reaction: a quantum chemical/statistical reaction rate theory study.

PubMed

da Silva, Gabriel; Bozzelli, Joseph W

2012-12-14

The resonance stabilized benzyl radical is an important intermediate in the combustion of aromatic hydrocarbons and in polycyclic aromatic hydrocarbon (PAH) formation in flames. Despite being a free radical, benzyl is relatively stable in thermal, oxidizing environments, and is predominantly removed through bimolecular reactions with open-shell species other than O(2). In this study the reaction of benzyl with ground-state atomic oxygen, O((3)P), is examined using quantum chemistry and statistical reaction rate theory. C(7)H(7)O energy surfaces are generated at the G3SX level, and include several novel pathways. Transition state theory is used to describe elementary reaction kinetics, with canonical variational transition state theory applied for barrierless O atom association with benzyl. Apparent rate constants and branching ratios to different product sets are obtained as a function of temperature and pressure from solving the time-dependent master equation, with RRKM theory for microcanonical k(E). These simulations indicate that the benzyl + O reaction predominantly forms the phenyl radical (C(6)H(5)) plus formaldehyde (HCHO), with lesser quantities of the C(7)H(6)O products benzaldehyde, ortho-quinone methide, and para-quinone methide (+H), along with minor amounts of the formyl radical (HCO) + benzene. Addition of O((3)P) to the methylene site in benzyl produces a highly vibrationally excited C(7)H(7)O* adduct, the benzoxyl radical, which can β-scission to benzaldehyde + H and phenyl + HCHO. In order to account for the experimental observation of benzene as the major reaction product, a roaming radical mechanism is proposed that converts the nascent products phenyl and HCHO to benzene + HCO. Oxygen atom addition at the ortho and para ring sites in benzyl, which has not been previously considered, is shown to lead to the quinone methides + H; these species are less-stable isomers of benzaldehyde that are proposed as important combustion intermediates, but are yet to be identified experimentally. Franck-Condon simulations of the benzaldehyde, o-quinone methide, and p-quinone methide photoelectron spectra suggest that these C(7)H(6)O isomers could be distinguished using tunable VUV photoionization mass spectrometry.

Environmental Forensics

DTIC Science & Technology

2011-03-29

Ethanol Benzophenone Benzophenone Stearyl alcohol Stearyl alcohol Fragrances Fragrances Shampoo Lipstick Benzaldehyde Glycerin Methylene Chloride...MatchInconclusiveMatchConclusion NO YES Unknown Coastal Background Sediments: National Survey  0 10 cm depth composites A-  Analytical Methods (EPA SW

A multifunctional chemical sensor based on a three-dimensional lanthanide metal-organic framework

DOE Office of Scientific and Technical Information (OSTI.GOV)

Du, Pei-Yao; Liao, Sheng-Yun; Gu, Wen, E-mail: guwen68@nankai.edu.cn

2016-12-15

A 3D lanthanide MOF with formula [Sm{sub 2}(abtc){sub 1.5}(H{sub 2}O){sub 3}(DMA)]·H{sub 2}O·DMA (1) has been successfully synthesized via solvothermal method. Luminescence studies reveal that 1 exhibits dual functional detection benzyl alcohol and benzaldehyde among different aromatic molecules. In addition, 1 displays a turn-on luminescence sensing with respect to ethanol among different alcohol molecules, which suggests that 1 is also a promising luminescent probe for high selective sensing of ethanol. - Highlights: • A three-dimensional lanthanide metal-organic framework has been synthesized. • Complex 1 exhibits dual functional detection benzyl alcohol and benzaldehyde among different aromatic molecules. • Complex 1 displays amore » turn-on luminescence sensing with respect to ethanol among different alcohol molecules.« less

Sustainable synthesis of aldehydes, ketones or acids from neat alcohols using nitrogen dioxide gas, and related reactions.

PubMed

Naimi-Jamal, M Reza; Hamzeali, Hamideh; Mokhtari, Javad; Boy, Jürgen; Kaupp, Gerd

2009-01-01

Benzylic alcohols are quantitatively oxidized by gaseous nitrogen dioxide to give pure aromatic aldehydes. The reaction gas mixtures are transformed to nitric acid, which renders the processes free of waste. The exothermic gas-liquid or gas-solid reactions profit from the solubility of nitrogen dioxide in the neat benzylic alcohols. The acid formed impedes further oxidation of the benzaldehydes. The neat isolated benzaldehydes and nitrogen dioxide quantitatively give the benzoic acids. Solid long-chain primary alcohols are directly and quantitatively oxidized with nitrogen dioxide gas to give the fatty acids in the solid state. The oxidations with ubiquitous nitrogen dioxide are extended to solid heterocyclic thioamides, which gives disulfides, and to diphenylamine, which gives tetraphenylhydrazine. These sustainable (green) specific oxidation procedures produce no dangerous residues from the oxidizing agent or from auxiliaries.

Investigation of extractive microbial transformation in nonionic surfactant micelle aqueous solution using response surface methodology.

PubMed

Xue, Yingying; Qian, Chen; Wang, Zhilong; Xu, Jian-He; Yang, Rude; Qi, Hanshi

2010-01-01

Extractive microbial transformation of L-phenylacetylcarbinol (L-PAC) in nonionic surfactant Triton X-100 micelle aqueous solution was investigated by response surface methodology. Based on the Box-Behnken design, a mathematical model was developed for the predication of mutual interactions between benzaldehyde, Triton X-100, and glucose on L-PAC production. It indicated that the negative or positive effect of nonionic surfactant strongly depended on the substrate concentration. The model predicted that the optimal concentration of benzaldehyde, Triton X-100, and glucose was 1.2 ml, 15 g, and 2.76 g per 100 ml, respectively. Under the optimal condition, the maximum L-PAC production was 27.6 mM, which was verified by a time course of extractive microbial transformation. A discrete fed-batch process for verification of cell activity was also presented.

Synthesis, spectral and antimicrobial activity of Zn(II) complexes with Schiff bases derived from 2-hydrazino-5-[substituted phenyl]-1,3,4-thiadiazole and benzaldehyde/2-hydroxyacetophenone/indoline-2,3-dione.

PubMed

Singh, Ajay K; Pandey, O P; Sengupta, S K

2013-09-01

Zn(II) complexes have been synthesized by reacting zinc acetate with Schiff bases derived from 2-hydrazino-5-[substituted phenyl]-1,3,4-thiadiazole and 2-hydroxyacetophenone/benzaldehyde/indoline-2,3-dione. All these complexes are soluble in DMF and DMSO; low molar conductance values indicate that they are non electrolytes. Elemental analyses suggest that the complexes have 1:2 metal to ligands stoichiometry of the types [ZnL2(H2O)2](L=monoanionic Schiff bases derived from 2-hydrazino-5-[substituted phenyl]-1,3,4-thiadiazole and 2-hydroxyacetophenone/indoline-2,3-dione) [ZnL2(')(OOCCH3)2(H2O)2](L'=neutral Schiff bases derived from 2-hydrazino-5-[substituted phenyl]-1,3,4-thiadiazole and benzaldehyde), and they were characterized by IR, (1)H NMR, and (13)C NMR. Particle sizes of synthesized compounds were measured with dynamic light scattering (DLS) analyser which indicates that particle diameter are of the range ca. 100-200nm. All these Schiff bases and their complexes have also been screened for their antibacterial (Bacillus subtilis (B. subtilis), Escherichia coli (E. coli) and antifungal activities (Colletotrichum falcatum (C. falcatum), Aspergillus niger (A. niger), Fusarium oxysporium (F. oxysporium) Curvularia pallescence (C. pallescence). The antimicrobial activities have shown that upon complexation the activity increases. Copyright © 2013 Elsevier B.V. All rights reserved.

Rotational Spectrum and Large Amplitude Motions of 3,4-, 2,5- and 3,5-DIMETHYL-BENZALDEHYDE

NASA Astrophysics Data System (ADS)

Kleiner, I.; Tudorie, M.; Jahn, M.; Grabow, J.-U.; Goubet, M.

2012-06-01

The microwave spectra of the 3,4-, 2,5- and 3,5-Dimethyl-Benzaldehyde (DMBA) molecules have been recorded for the first time in the 2-26.5 GHz frequency range, using the COBRA-FTMW spectrometer in Hannover, with an instrumental uncertainty of 0.5 kHz for unblended lines. The experimental assignments and fits are supplemented by ab initio quantum chemical calculations,conformational energy landscape, and dipole moment components. The analysis of the spectra for the three isomers are in progress. The latest results, including spectroscopic constants and large amplitude motion parameters, will be presented. This investigation follows the study of the spectra of the 4-Methyl-Benzaldehyde molecule. The DMBA isomers belong to a similar series of molecules formally obtained by adding a second methyl group at the aromatic ring. These molecules serve as prototype systems for the development of the theoretical model of asymmetric top molecules having Cs symmetry while containing two inequivalent methyl tops (C3v), exhibiting different barrier heights and coupling terms to methyl internal rotation. Thus, the DMBA isomers represent benchmark species for testing the two-top internal rotors BELGI program written recently. Supported by the ANR-08-BLAN-0054 contract (France), the Deutsche Forschungsgemeinschaft, and the Land Niedersachsen (Germany). H. Saal, W. Caminati, I. Kleiner, A. R. Hight-Walker, J. T. Hougen, J.-U. Grabow, to be published. M. Tudorie, I. Kleiner, J. T. Hougen, S. Melandri, L. W. Sutikdja, W. Stahl, J. Mol. Spectrosc., 269 (2011), 211-225

Analysis of residual products in benzyl chloride used for the industrial synthesis of quaternary compounds by liquid chromatography with diode-array detection.

PubMed

Prieto-Blanco, M C; López-Mahía, P; Prada-Rodríguez, D

2009-02-01

In industrial and pharmaceutical processes, the study of residual products becomes essential to guarantee the quality of compounds and to eliminate or minimize toxic residual products. Knowledge about the origin of impurities (raw materials, processes, the contamination of industrial plants, etc.) is necessary in preventive treatment and in the control of a product's lifecycle. Benzyl chloride is used as raw material to synthesize several quaternary ammonium compounds, such as benzalkonium chloride, which may have pharmaceutical applications. Benzaldehyde, benzyl alcohol, toluene, chloro derivatives of toluene, and dibenzyl ether are compounds that may be found as impurities in technical benzyl chloride. We proposed a high-performance liquid chromatography method for the separation of these compounds, testing two stationary phases with different dimensions and particle sizes, with the application of photodiode array-detection. The linearity for four possible impurities (benzaldehyde, toluene, alpha,alpha-dichlorotoluene, and 2-chlorotoluene) ranged from 0.1 to 10 microg/mL, limits of detection from 11 to 34 ng/mL, and repeatability from 1% to 2.9% for a 0.3-1.2 microg/mL concentration range. The method was applied to samples of technical benzyl chloride, and alpha,alpha-dichlorotoluene and benzaldehyde were identified by spectral analysis and quantitated. The selection of benzyl chloride with lower levels of impurities is important to guarantee the reduction of residual products in further syntheses.

Solvent influence on the photophysical properties of 4-(2-Oxo-2H-benzo[h]chromen-4-ylmethoxy)-benzaldehyde

NASA Astrophysics Data System (ADS)

Pramod, A. G.; Renuka, C. G.; Shivashankar, K.; Boregowda, P.; Nadaf, Y. F.

2018-05-01

Steady-state absorption and the fluorescence properties of the synthesized Benzofuran derivatives were studied. Absorption and fluorescence spectra of 4-(2-Oxo-2H-benzo[h]chromen-4-ylm ethoxy)-benzaldehyde (4-OBCM) have been recorded at room temperature in extensive variety of solvents of various polarities. 4-OBCM Fluorescence band maxima of the solvents are small amount spectral shifted to hypsochromic when the solvent polarity will increase, compared to absorption band under the identical circumstance. This suggests an increase in dipole moment of excited state compared to ground state. The ground-state dipole moment of 4-OBCM was found from quantum mechanical methods and the excited state dipole moment of 4-OBCM was evaluated from Lippert-Mataga Bakhshiev's, Kawski-Chamma-Viallet's and Reichardt conditions by methods for solvatochromic shift. Kamlet-Taft coefficients which affect this absorption profiles.

Benzaldehyde, 2-hydroxybenzoyl hydrazone derivatives as inhibitors of the corrosion of aluminium in hydrochloric acid.

PubMed

Fouda, A S; Gouda, M M; El-Rahman, S I

2000-05-01

The effect of benzaldehyde, 2-hydroxybenzoyl hydrazone derivatives on the corrosion of aluminium in hydrochloric acid has been investigated using thermometric and polarization techniques. The inhibitive efficiency ranking of these compounds from both techniques was found to be: 2>3>1>4. The inhibitors acted as mixed-type inhibitors but the cathode is more polarized. The relative inhibitive efficiency of these compounds has been explained on the basis of structure of the inhibitors and their mode of interaction at the surface. Results show that these additives are adsorbed on an aluminium surface according to the Langmuir isotherm. Polarization measurements indicated that the rate of corrosion of aluminium rapidly increases with temperature over the range 30-55 degrees C both in the absence and in the presence of inhibitors. Some thermodynamic data of the adsorption process are calculated and discussed.

4-{2-[2-(4-Formyl­phen­oxy)eth­oxy]eth­oxy}benzaldehyde

PubMed Central

Ma, Zhen; Cao, Yiqun

2011-01-01

The title compound, C18H18O5, was obtained by the reaction of 4-hy­droxy­benzaldehyde with bis­(2,2-dichloro­eth­yl) ether in dimethyl­formamide. In the crystal, the mol­ecule lies on a twofold rotation axis that passes through the central O atom of the aliphatic chain, thus leading to one half-mol­ecule being present per asymmetric unit. The carbonyl, aryl and O—CH2—CH2 groups are almost coplanar, with an r.m.s. deviation of 0.030 Å. The aromatic rings are approximately perpendicular to each other, forming a dihedral angle of 78.31 sh;H⋯O hydrogen bonds and C—H⋯π inter­actions help to consolidate the three-dimensional network. PMID:21754870

EVALUATION OF THE SYNTHESIS AND STRUCTURE OF NEW AZETIDIN-2-ONES OF FERULIC ACID.

PubMed

Stan, Cătălina Daniela; Drăgan, Maria; Pânzariu, Andreea; Profire, Lenuţa

2016-01-01

To synthesize some new azetidin-2-ones of ferulic acid and to evaluate them from physicochemical and spectral point of view. The synthesis was carried out in several steps: (i) obtaining the ferulic acid chloride; (ii) obtaining the ferulic acid hydrazide with hydrazine hydrate (98%); (iii) condensation of ferulic acid hydrazide with different benzaldehydes (2-hydroxy-/2-nitro-/4-chloro-/4- fluoro-/4-bromo-benzaldehyde) in order to obtain the corresponding hydrazones; (iv) cy- clization of ferulic acid hydrazones with chloroacethyl chloride in freshly distilled toluene medium and in the presence of triethylamine, resulting in the corresponding azetidin-2-ones. Six new azetidin-2-ones of ferulic acid were synthesized. They were characterized in terms of their physicochemical properties and their structure was confirmed by IR and 1H-NMR spectroscopy. Six new azetidin-2-ones of ferulic acid were synthesized, physicochemically characterized and validated spectrally. A

Ultrasound-assisted synthesis of curcumin analogs promoted by activated chicken eggshells

NASA Astrophysics Data System (ADS)

Mardiana, L.; Ardiansah, B.; Septiarti, A.; Bakri, R.; Kosamagi, G.

2017-07-01

Curcumin has been widely known as a multifunctional natural product which has many biological activities. However, the biggest limitation for the large scale application of curcumin is its poor bioavailability. This research presented a cheap, mild and efficient solvent-free synthesis of monocarbonyl analogs of curcumin via Aldol condensation using activated chicken eggshells (ACE). Dibenzalpropanone as a product of Aldol condensation was prepared by mixing benzaldehyde and acetone using a simple glass tube in the presence of ACE under ultrasound irradiation (78 % yield), while dibenzalcyclohexanone was produced from the reaction of benzaldehyde with cyclohenxanone (81 %). The products have been characterized by FTIR, UV-Vis spectrophotometer and GC-MS instruments. The FTIR spectra show a significant absorption of carbonyl group that attached to the double bond in α,β-position at 1630-1660 cm-1. The molecular cation of m/z of 234 and 274 is in agreement with the products structures.

Analysis and optimization of a synthetic milkweed floral attractant for mosquitoes.

PubMed

Otienoburu, Philip E; Ebrahimi, Babak; Phelan, P Larry; Foster, Woodbridge A

2012-07-01

A pentane extract of flowers of common milkweed, Asclepias syriaca (Asclepiadaceae), elicited significant orientation from both male and female Culex pipiens in a dual-port flight olfactometer. Analysis of the extract by gas chromatography-mass spectrometry revealed six major constituents in order of relative abundance: benzaldehyde, (E)-β-ocimene, phenylacetaldehyde, benzyl alcohol, nonanal, and (E)-2-nonenal. Although not all were collected from the headspace profile of live flowers, a synthetic blend of these six compounds, when presented to mosquitoes in the same levels and proportions that occur in the extract, elicited a response comparable to the extract. Subtractive behavioral bioassays demonstrated that a three-component blend consisting of benzaldehyde, phenylacetaldehyde, and (E)-2-nonenal was as attractive as the full blend. These findings suggest the potential use of synthetic floral-odor blends for monitoring or control of both male and female disease-vectoring mosquitoes.

Spectroscopic studies and structure of 3-methoxy-2 -[(2,4,4,6,6-pentachloro-1,3,5,2{lambda}{sup 5},4{lambda}{sup 5},6{lambda}{sup 5}-triazatriphosphin-2-yl)oxy] benzaldehyde

DOE Office of Scientific and Technical Information (OSTI.GOV)

Oezay, H.; Yildiz, M., E-mail: myildiz@comu.edu.tr; Uenver, H.

2013-01-15

The compound called 3-methoxy-2- [(2,4,4,6,6-pentachloro-1,3,5,2{lambda}{sup 5},4{lambda}{sup 5},6{lambda}{sup 5}-triazatriphosphin-2-yl)oxy] benzaldehyde has been synthesized from the reaction of 2-hydroxy-3-methoxybenzaldehyde with hexachlorocyclotriphosphazene. It has been characterized by elemental analysis, MS, IR, {sup 1}H NMR, {sup 13}C NMR, {sup 31}P NMR and UV-visible spectroscopic techniques. The structure of the title compound has been determind by X-ray analysis. Crystals are orthorhombic, space group P2{sub 1}2{sub 1}2{sub 1}, Z = 4, a = 7.705(1), b = 12.624(1), c = 17.825(2) A, R{sub 1} = 0.0390 and wR{sub 2} = 0.1074 [I > 2{sigma}(I)], respectively.

Growth, structural, thermal, dielectric and optical studies on HBST crystal: A potential THz emitter.

PubMed

Ma, Yuzhe; Teng, Bing; Cao, Lifeng; Zhong, Degao; Ji, Shaohua; Teng, Fei; Liu, Jiaojiao; Yao, Yuan; Tang, Jie; Tong, Jiaming

2018-02-05

The efficient organic nonlinear optical material 4-hydroxy benzaldehyde-N-methyl 4-stilbazolium tosylate (HBST) was grown from methanol by slope nucleation method combined with slow cooling (SNM-SC) for the first time. The optimum growth conditions based on the cooling rate was further investigated. The single crystal X-ray diffraction (XRD) revealed that the chromophores of HBST crystal make an angle of about 33° with respect to the a-axis, which is close to the optimum of Terahertz (THz)-wave generation and electro-optics applications. NMR and FT-IR spectral studies have been performed to ascertain various functional groups present in the sample. Futhermore, the thermal stability and decomposition stages were analyzed through TG-DTA and DSC techniques. The dielectric constant and dielectric loss of HBST crystal have been studied. Critical optical properties like the absorption coefficient, refractive index, cut-off wavelength and band gap energy were calculated. Photoluminescence (PL) exication studies indicated green emission occured at 507nm. All the results of HBST crystal make it a promising candidate in the fields of optoelectronic and the generation of THz. Copyright © 2017 Elsevier B.V. All rights reserved.

Identification of Volatile Flavor Components by Headspace Analysis: A Quick and Easy Experiment for Introducing GC/MS

NASA Astrophysics Data System (ADS)

Kjonaas, Richard; Soller, Jean L.; McCoy, Leslee A.

1997-09-01

By placing a piece of chewing gum (Wrigley's) or a crushed piece of hard candy (LifeSavers or Runts) into a vial, followed by GC/MS analysis of a five microliter sample of the headspace, students are able to identify several of the volatile flavoring components which are present. The experiment has been used successfully with sophomore organic chemistry students, and with visiting groups of talented high school students over a three year period. Identification is simplified by handing out a list of the structural formulas of some likely candidates. Some of the components that these students easily identity include ethyl acetate, isobutyl acetate, isoamyl acetate, ethyl butyrate, benzaldehyde, benzyl alcohol, limonene, and cinnamaldehyde. Some of the more difficult to identify components include menthol, menthone, carvone, cineole, myrcene, alpha-pinene, beta-pinene, para-cymene, and gama-terpinene. Most of the major headspace components give signals whose size is comparable to that of the carbon dioxide which is present in each injection. Even with split injection, the background noise is trivial compared to the signals from the major components. The experiments were carried out with a commercially available tabletop GC/MS (Varian 3400 with Saturn MS).

Formation of highly oxygenated low-volatility products from cresol oxidation

NASA Astrophysics Data System (ADS)

Schwantes, Rebecca H.; Schilling, Katherine A.; McVay, Renee C.; Lignell, Hanna; Coggon, Matthew M.; Zhang, Xuan; Wennberg, Paul O.; Seinfeld, John H.

2017-03-01

Hydroxyl radical (OH) oxidation of toluene produces ring-retaining products: cresol and benzaldehyde, and ring-opening products: bicyclic intermediate compounds and epoxides. Here, first- and later-generation OH oxidation products from cresol and benzaldehyde are identified in laboratory chamber experiments. For benzaldehyde, first-generation ring-retaining products are identified, but later-generation products are not detected. For cresol, low-volatility (saturation mass concentration, C* ˜ 3.5 × 104 - 7.7 × 10-3 µg m-3), first- and later-generation ring-retaining products are identified. Subsequent OH addition to the aromatic ring of o-cresol leads to compounds such as hydroxy, dihydroxy, and trihydroxy methyl benzoquinones and dihydroxy, trihydroxy, tetrahydroxy, and pentahydroxy toluenes. These products are detected in the gas phase by chemical ionization mass spectrometry (CIMS) and in the particle phase using offline direct analysis in real-time mass spectrometry (DART-MS). Our data suggest that the yield of trihydroxy toluene from dihydroxy toluene is substantial. While an exact yield cannot be reported as authentic standards are unavailable, we find that a yield for trihydroxy toluene from dihydroxy toluene of ˜ 0.7 (equal to the reported yield of dihydroxy toluene from o-cresol; Olariu et al., 2002) is consistent with experimental results for o-cresol oxidation under low-NO conditions. These results suggest that even though the cresol pathway accounts for only ˜ 20 % of the oxidation products of toluene, it is the source of a significant fraction (˜ 20-40 %) of toluene secondary organic aerosol (SOA) due to the formation of low-volatility products.

Near-infrared light controlled photocatalytic activity of carbon quantum dots for highly selective oxidation reaction

NASA Astrophysics Data System (ADS)

Li, Haitao; Liu, Ruihua; Lian, Suoyuan; Liu, Yang; Huang, Hui; Kang, Zhenhui

2013-03-01

Selective oxidation of alcohols is a fundamental and significant transformation for the large-scale production of fine chemicals, UV and visible light driven photocatalytic systems for alcohol oxidation have been developed, however, the long wavelength near infrared (NIR) and infrared (IR) light have not yet fully utilized by the present photocatalytic systems. Herein, we reported carbon quantum dots (CQDs) can function as an effective near infrared (NIR) light driven photocatalyst for the selective oxidation of benzyl alcohol to benzaldehyde. Based on the NIR light driven photo-induced electron transfer property and its photocatalytic activity for H2O2 decomposition, this metal-free catalyst could realize the transformation from benzyl alcohol to benzaldehyde with high selectivity (100%) and conversion (92%) under NIR light irradiation. HO&z.rad; is the main active oxygen specie in benzyl alcohol selective oxidative reaction confirmed by terephthalic acid photoluminescence probing assay (TA-PL), selecting toluene as the substrate. Such metal-free photocatalytic system also selectively converts other alcohol substrates to their corresponding aldehydes with high conversion, demonstrating a potential application of accessing traditional alcohol oxidation chemistry.Selective oxidation of alcohols is a fundamental and significant transformation for the large-scale production of fine chemicals, UV and visible light driven photocatalytic systems for alcohol oxidation have been developed, however, the long wavelength near infrared (NIR) and infrared (IR) light have not yet fully utilized by the present photocatalytic systems. Herein, we reported carbon quantum dots (CQDs) can function as an effective near infrared (NIR) light driven photocatalyst for the selective oxidation of benzyl alcohol to benzaldehyde. Based on the NIR light driven photo-induced electron transfer property and its photocatalytic activity for H2O2 decomposition, this metal-free catalyst could realize the transformation from benzyl alcohol to benzaldehyde with high selectivity (100%) and conversion (92%) under NIR light irradiation. HO&z.rad; is the main active oxygen specie in benzyl alcohol selective oxidative reaction confirmed by terephthalic acid photoluminescence probing assay (TA-PL), selecting toluene as the substrate. Such metal-free photocatalytic system also selectively converts other alcohol substrates to their corresponding aldehydes with high conversion, demonstrating a potential application of accessing traditional alcohol oxidation chemistry. Electronic supplementary information (ESI) available. See DOI: 10.1039/c3nr00092c

Coordination behavior of ligand based on NNS and NNO donors with ruthenium(III) complexes and their catalytic and DNA interaction studies

NASA Astrophysics Data System (ADS)

Manikandan, R.; Viswnathamurthi, P.

2012-11-01

Reactions of 2-acetylpyridine-thiosemicarbazone HL1, 2-acetylpyridine-4-methyl-thiosemicarbazone HL2, 2-acetylpyridine-4-phenyl-thiosemicarbazone HL3 and 2-acetylpyridine-semicarbazone HL4 with ruthenium(III) precursor complexes were studied and the products were characterized by analytical and spectral (FT-IR, electronic, EPR and EI-MS) methods. The ligands coordinated with the ruthenium(III) ion via pyridine nitrogen, azomethine nitrogen and thiolate sulfur/enolate oxygen. An octahedral geometry has been proposed for all the complexes based on the studies. All the complexes are redox active and display an irreversible and quasireversible metal centered redox processes. Further, the catalytic activity of the new complexes has been investigated for the transfer hydrogenation of ketones in the presence of isopropanol/KOH and the Kumada-Corriu coupling of aryl halides with aryl Grignard reagents. The DNA cleavage efficiency of new complexes has also been tested.

Provisional Peer-Reviewed Toxicity Values for Benzaldehyde

EPA Science Inventory

Provisional Peer-Reviewed Toxicity Values (PPRTV) assessments are developed for use by the Agency’s Office of Land and Emergency Management (OLEM) to support informed decisions in the Superfund program and at hazardous waste sites when a values is not available in the Integrated ...

Health-Beneficial Phenolic Aldehyde in Antigonon leptopus Tea

PubMed Central

Mulabagal, Vanisree; Alexander-Lindo, Ruby L.; DeWitt, David L.; Nair, Muraleedharan G.

2011-01-01

Tea prepared from the aerial parts of Antigonon leptopus is used as a remedy for cold and pain relief in many countries. In this study, A. leptopus tea, prepared from the dried aerial parts, was evaluated for lipid peroxidation (LPO) and cyclooxygenase (COX-1 and COX-2) enzyme inhibitory activities. The tea as a dried extract inhibited LPO, COX-1 and COX-2 enzymes by 78%, 38% and 89%, respectively, at 100 μg/mL. Bioassay-guided fractionation of the extract yielded a selective COX-2 enzyme inhibitory phenolic aldehyde, 2,3,4-trihydroxy benzaldehyde. Also, it showed LPO inhibitory activity by 68.3% at 6.25 μg/mL. Therefore, we have studied other hydroxy benzaldehydes and their methoxy analogs for LPO, COX-1 and COX-2 enzymes inhibitory activities and found that compound 1 gave the highest COX-2 enzyme inhibitory activity as indicated by a 50% inhibitory concentration (IC50) at 9.7 μg/mL. The analogs showed only marginal LPO activity at 6.25 μg/mL. The hydroxy analogs 6, 7 and 9 showed 55%, 61% and 43% of COX-2 inhibition at 100 μg/mL. However, hydroxy benzaldehydes 3 and 12 showed selective COX-1 inhibition while compounds 4 and 10 gave little or no COX-2 enzyme inhibition at 100 μg/mL. At the same concentration, compounds 14, 21 and 22 inhibited COX-1 by 83, 85 and 70%, respectively. Similarly, compounds 18, 19 and 23 inhibited COX-2 by 68%, 72% and 70%, at 100 μg/mL. This is the first report on the isolation of compound 1 from A. leptopus tea with selective COX-2 enzyme and LPO inhibitory activities. PMID:19454555

Novel Scheme for Biosynthesis of Aryl Metabolites from l-Phenylalanine in the Fungus Bjerkandera adusta

PubMed Central

Lapadatescu, Carmen; Giniès, Christian; Le Quéré, Jean-Luc; Bonnarme, Pascal

2000-01-01

Aryl metabolite biosynthesis was studied in the white rot fungus Bjerkandera adusta cultivated in a liquid medium supplemented with l-phenylalanine. Aromatic compounds were analyzed by gas chromatography-mass spectrometry following addition of labelled precursors (14C- and 13C-labelled l-phenylalanine), which did not interfere with fungal metabolism. The major aromatic compounds identified were benzyl alcohol, benzaldehyde (bitter almond aroma), and benzoic acid. Hydroxy- and methoxybenzylic compounds (alcohols, aldehydes, and acids) were also found in fungal cultures. Intracellular enzymatic activities (phenylalanine ammonia lyase, aryl-alcohol oxidase, aryl-alcohol dehydrogenase, aryl-aldehyde dehydrogenase, lignin peroxidase) and extracellular enzymatic activities (aryl-alcohol oxidase, lignin peroxidase), as well as aromatic compounds, were detected in B. adusta cultures. Metabolite formation required de novo protein biosynthesis. Our results show that l-phenylalanine was deaminated to trans-cinnamic acid by a phenylalanine ammonia lyase and trans-cinnamic acid was in turn converted to aromatic acids (phenylpyruvic, phenylacetic, mandelic, and benzoylformic acids); benzaldehyde was a metabolic intermediate. These acids were transformed into benzaldehyde, benzyl alcohol, and benzoic acid. Our findings support the hypothesis that all of these compounds are intermediates in the biosynthetic pathway from l-phenylalanine to aryl metabolites. Additionally, trans-cinnamic acid can also be transformed via β-oxidation to benzoic acid. This was confirmed by the presence of acetophenone as a β-oxidation degradation intermediate. To our knowledge, this is the first time that a β-oxidation sequence leading to benzoic acid synthesis has been found in a white rot fungus. A novel metabolic scheme for biosynthesis of aryl metabolites from l-phenylalanine is proposed. PMID:10742235

Toluene, Methanol and Benzaldehyde Removal from Gas Streams by Adsorption onto Natural Clay and Faujasite-Y type Zeolite.

PubMed

Zaitan, Hicham; Mohamed, Elham F; Valdés, Héctor; Nawdali, Mostafa; Rafqah, Salah; Manero, Marie Hélène

2016-12-01

A great number of pollution problems come as a result of the emission of Volatile Organic Compounds (VOCs) into the environment and their control becomes a serious challenge for the global chemical industry. Adsorption is a widely used technique for the removal of VOCs due to its high efficiency, low cost, and convenient operation. In this study, the feasibility to use a locally available clay, as adsorbent material to control VOCs emissions is evaluated. Natural clay is characterised by different physical-chemical methods and adsorptive interaction features between VOCs and natural clay are identified. Toluene (T), methanol (M) and benzaldehyde (B) are used here as representatives of three different kinds of VOCs. Adsorption isotherms onto natural clay and faujasite-Y type zeolite (Fau Y) are obtained at room temperature. According to Langmuir model data, maximum adsorption capacities (qm) of Fez natural clay and zeolite toward methanol (M), toluene (T) and benzaldehyde (B) at 300 K are 8, 0.89 and 3.1 mmol g-1, and 15, 1.91 and 13.9 mmol g-1 respectively. In addition, the effect of temperature on the adsorption of toluene onto natural clay is evaluated in the range from 300 to 323K. An increase on temperature reduces the adsorption capacity of natural clay toward toluene, indicating that an exothermic physical adsorption process takes place. The enthalpy of adsorption of toluene onto Fez natural clay was found to be -54 kJ mol-1. A preliminary cost analysis shows that natural clay could be used as an alternative low cost adsorbent in the control of VOCs from contaminated gas streams with a cost of US$ 0.02 kg-1 compared to Fau Y zeolite with US$ 10 kg-1.

21 CFR 182.60 - Synthetic flavoring substances and adjuvants.

Code of Federal Regulations, 2010 CFR

2010-04-01

... (parapropenyl anisole). Benzaldehyde (benzoic aldehyde). N-Butyric acid (butanoic acid). d- or l-Carvone (carvol). Cinnamaldehyde (cinnamic aldehyde). Citral (2,6-dimethyloctadien-2,6-al-8, gera-nial, neral). Decanal (N-decylaldehyde, capraldehyde, capric aldehyde, caprinaldehyde, aldehyde C-10). Ethyl acetate. Ethyl butyrate. 3...

21 CFR 182.60 - Synthetic flavoring substances and adjuvants.

Code of Federal Regulations, 2011 CFR

2011-04-01

... (parapropenyl anisole). Benzaldehyde (benzoic aldehyde). N-Butyric acid (butanoic acid). d- or l-Carvone (carvol). Cinnamaldehyde (cinnamic aldehyde). Citral (2,6-dimethyloctadien-2,6-al-8, gera-nial, neral). Decanal (N-decylaldehyde, capraldehyde, capric aldehyde, caprinaldehyde, aldehyde C-10). Ethyl acetate. Ethyl butyrate. 3...

21 CFR 182.60 - Synthetic flavoring substances and adjuvants.

Code of Federal Regulations, 2013 CFR

2013-04-01

... (parapropenyl anisole). Benzaldehyde (benzoic aldehyde). N-Butyric acid (butanoic acid). d- or l-Carvone (carvol). Cinnamaldehyde (cinnamic aldehyde). Citral (2,6-dimethyloctadien-2,6-al-8, gera-nial, neral). Decanal (N-decylaldehyde, capraldehyde, capric aldehyde, caprinaldehyde, aldehyde C-10). Ethyl acetate. Ethyl butyrate. 3...

21 CFR 182.60 - Synthetic flavoring substances and adjuvants.

Code of Federal Regulations, 2012 CFR

2012-04-01

... (parapropenyl anisole). Benzaldehyde (benzoic aldehyde). N-Butyric acid (butanoic acid). d- or l-Carvone (carvol). Cinnamaldehyde (cinnamic aldehyde). Citral (2,6-dimethyloctadien-2,6-al-8, gera-nial, neral). Decanal (N-decylaldehyde, capraldehyde, capric aldehyde, caprinaldehyde, aldehyde C-10). Ethyl acetate. Ethyl butyrate. 3...

Surface Plasmon Resonance Based Sensitive Immunosensor for Benzaldehyde Detection

NASA Astrophysics Data System (ADS)

Onodera, Takeshi; Shimizu, Takuzo; Miura, Norio; Matsumoto, Kiyoshi; Toko, Kiyoshi

Fragrant compounds used to add flavor to beverages remain in the manufacturing line after the beverage manufacturing process. Line cleanliness before the next manufacturing cycle is difficult to estimate by sensory analysis, making excessive washing necessary. A new measurement system to determine line cleanliness is desired. In this study, we attempted to detect benzaldehyde (Bz) using an anti-Bz monoclonal antibody (Bz-Ab) and a surface plasmon resonance (SPR) sensor. We fabricated two types of sensor chips using self-assembled monolayers (SAMs) and investigated which sensor surface exhibited higher sensitivity. In addition, anti-Bz antibody conjugated with horseradish peroxidase (HRP-Bz-Ab) was used to enhance the SPR signal. A detection limit of ca. 9ng/mL (ppb) was achieved using an immobilized 4-carboxybenzaldehyde sensor surface using SAMs containing ethylene glycol. When the HRP-Bz-Ab concentration was reduced to 30ng/mL, a detection limit of ca. 4ng/mL (ppb) was achieved for Bz.

Comparative reactivity of different types of stable cyclic and acyclic mono- and diamino carbenes with simple organic substrates.

PubMed

Martin, David; Canac, Yves; Lavallo, Vincent; Bertrand, Guy

2014-04-02

A series of stable carbenes, featuring a broad range of electronic properties, were reacted with simple organic substrates. The N,N-dimesityl imidazolylidene (NHC) does not react with isocyanides, whereas anti-Bredt di(amino)carbene (pyr-NHC), cyclic (alkyl)(amino)carbene (CAAC), acyclic di(amino)carbene (ADAC), and acyclic (alkyl)(amino)carbene (AAAC) give rise to the corresponding ketenimines. NHCs are known to promote the benzoin condensation, and we found that the CAAC, pyr-NHC, and ADAC react with benzaldehyde to give the ketone tautomer of the Breslow intermediate, whereas the AAAC first gives the corresponding epoxide and ultimately the Breslow intermediate, which can be isolated. Addition of excess benzaldehyde to the latter does not lead to benzoin but to a stable 1,3-dioxolane. Depending on the electronic properties of carbenes, different products are also obtained with methyl acrylate as a substrate. The critical role of the carbene electrophilicity on the outcome of reactions is discussed.

OH-radical induced degradation of hydroxybenzoic- and hydroxycinnamic acids and formation of aromatic products—A gamma radiolysis study

NASA Astrophysics Data System (ADS)

Krimmel, Birgit; Swoboda, Friederike; Solar, Sonja; Reznicek, Gottfried

2010-12-01

The OH-radical induced degradation of hydroxybenzoic acids (HBA), hydroxycinnamic acids (HCiA) and methoxylated derivatives, as well as of chlorogenic acid and rosmarinic acid was studied by gamma radiolysis in aerated aqueous solutions. Primary aromatic products resulting from an OH-radical attachment to the ring (hydroxylation), to the position occupied by the methoxyl group (replacement -OCH 3 by -OH) as well as to the propenoic acid side chain of the cinnamic acids (benzaldehyde formations) were analysed by HPLC-UV and LC-ESI-MS. A comparison of the extent of these processes is given for 3,4-dihydroxybenzoic acid, vanillic acid, isovanillic acid, syringic acid, cinnamic acid, 4-hydroxycinnamic acid, caffeic acid, ferulic acid, isoferulic acid, chlorogenic acid, and rosmarinic acid. For all cinnamic acids and derivatives benzaldehydes were significant oxidation products. With the release of caffeic acid from chlorogenic acid the cleavage of a phenolic glycoside could be demonstrated. Reaction mechanisms are discussed.

Molecular docking study, synthesis and biological evaluation of Schiff bases as Hsp90 inhibitors.

PubMed

Dutta Gupta, Sayan; Snigdha, D; Mazaira, Gisela I; Galigniana, Mario D; Subrahmanyam, C V S; Gowrishankar, N L; Raghavendra, N M

2014-04-01

Heat shock protein 90 (Hsp90) is an emerging attractive target for the discovery of novel cancer therapeutic agents. Docking methods are powerful in silico tools for lead generation and optimization. In our mission to rationally develop novel effective small molecules against Hsp90, we predicted the potency of our designed compounds by Sybyl surflex Geom X docking method. The results of the above studies revealed that Schiff bases derived from 2,4-dihydroxy benzaldehyde/5-chloro-2,4-dihydroxy benzaldehyde demonstrated effective binding with the protein. Subsequently, a few of them were synthesized (1-10) and characterized by IR, (1)HNMR and mass spectral analysis. The synthesized molecules were evaluated for their potential to suppress Hsp90 ATPase activity by Malachite green assay. The anticancer studies were performed by 3-(4,5-dimethythiazol- 2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay method. The software generated results was in satisfactory agreement with the evaluated biological activity. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

Zwitterionic-surfactant-stabilized palladium nanoparticles as catalysts in the hydrogen transfer reductive amination of benzaldehydes.

PubMed

Drinkel, Emma E; Campedelli, Roberta R; Manfredi, Alex M; Fiedler, Haidi D; Nome, Faruk

2014-03-21

Palladium nanoparticles (NPs) stabilized by a zwitterionic surfactant are revealed here to be good catalysts for the reductive amination of benzaldehydes using formate salts as hydrogen donors in aqueous isopropanol. In terms of environmental impact and economy, metallic NPs offer several advantages over homogeneous and traditional heterogeneous catalysts. NPs usually display greater activity due to the increased metal surface area and sometimes exhibit enhanced selectivity. Thus, it is possible to use very low loadings of expensive metal. The methodology eliminates the use of a hydrogen gas atmosphere or toxic or expensive reagents. A range of aromatic aldehydes were converted to benzylamines when reacted with primary and secondary amines in the presence of the Pd NPs, which also displayed good activity when supported on alumina. In every case, the Pd NPs could be easily recovered and reused up to three more times, and at the end of the process, the product was metal-free.

Substituent effect of phenolic aldehyde inhibition on alcoholic fermentation by Saccharomyces cerevisiae

Treesearch

Rui Xie; Maobing Tu; Thomas Elder

2016-01-01

Phenolic compounds significantly inhibit microbial fermentation of biomass hydrolysates. To understand thequantitative structure-inhibition relationship of phenolic aldehydes on alcoholic fermentation, the effect of 11 differentsubstituted benzaldehydes on the final ethanol yield was examined. The results showed that the degree of phenolic...

Catalytic Hydrogenation of Organic Compounds without H2 Supply: An Electrochemical System

ERIC Educational Resources Information Center

Navarro, Daniela Maria do Amaral Ferraz; Navarro, Marcelo

2004-01-01

An experiment developed for an undergraduate organic chemistry laboratory course that can be used to introduce the catalytic hydrogenation reaction, catalysis electrochemical principles and gas chromatography is presented. The organic compounds hydrogenated by the electrocatalytic hydrogenation (ECH) process were styrene, benzaldehyde and…

Benzyl Derivatives with in Vitro Binding Affinity for Human Opioid Receptors and Cannabinoid Receptors from the Fungus Eurotium repens

USDA-ARS?s Scientific Manuscript database

Bioassay-guided fractionation of the fungus Eurotium repens resulted in the isolation of two benzyl derivatives, repenol A (1) and repenol B (2). Seven known secondary metabolites were also isolated including five benzaldehyde compounds, flavoglaucin (3), tetrahydroauroglaucin (4), dihydroauroglauci...

A Novel NADPH-Dependent Aldehyde Reductase Gene from Saccharomyces cerevisiae NRRL Y-12632 Involved in the Detoxification of Aldehyde Inhibitors Derived from Lignocellulosic Biomass Conversion

USDA-ARS?s Scientific Manuscript database

Aldehyde inhibitors such as furfural, 5-hydroxymethylfurfural (HMF), anisaldehyde, benzaldehyde, cinnamaldehyde, and phenylaldehyde are commonly generated during lignocellulosic biomass conversion process for low-cost cellulosic ethanol production that interferes with subsequent microbial growth and...

Azeotropic Preparation of a "C"-Phenyl "N"-Aryl Imine: An Introductory Undergraduate Organic Chemistry Laboratory Experiment

ERIC Educational Resources Information Center

Silverberg, Lee J.; Coyle, David J.; Cannon, Kevin C.; Mathers, Robert T.; Richards, Jeffrey A.; Tierney, John

2016-01-01

Imines are important in biological chemistry and as intermediates in organic synthesis. An experiment for introductory undergraduate organic chemistry is presented in which benzaldehyde was condensed with "p"-methoxyaniline in toluene to give 4-methoxy-"N"-(phenylmethylene)benzenamine. Water was removed by azeotropic…

Investigation of Solvent Effects on the Rate and Stereoselectivity of the Henry Reaction

PubMed Central

Kostal, Jakub; Voutchkova, Adelina M.; Jorgensen, William L.

2011-01-01

A combined computational and experimental kinetic study on the Henry reaction is reported. The effects of salvation on the transition structures and the rates of reaction between nitromethane and formaldehyde, and between nitropropane and benzaldehyde are elucidated with QM/MM calculations. PMID:22168236

Solvent-Free Synthesis of Chalcones

ERIC Educational Resources Information Center

Palleros, Daniel R.

2004-01-01

The synthesis of twenty different chalcones in the absence of solvent is presented. The results indicated that out of the twenty different chalcones investigated seventeen can be obtained in a matter of minutes by mixing the corresponding benzaldehyde and acetophenone in the presence of solid NaOH in a mortar with pestle.

Annulation of o-Quinodimethanes through N-Heterocyclic Carbene Catalysis for the Synthesis of 1-Isochromanones.

PubMed

Janssen-Müller, Daniel; Singha, Santanu; Olyschläger, Theresa; Daniliuc, Constantin G; Glorius, Frank

2016-09-02

The activation of 2-(bromomethyl)benzaldehydes using N-heterocyclic carbenes represents a novel approach to the generation of o-quinodimethane (o-QDM) intermediates. Coupling with ketones such as phenylglyoxylates, isatins, or trifluoromethyl ketones via [4 + 2] annulation gives access to functionalized 1-isochromanones.

Real World of Industrial Chemistry: Organic Chemicals from Carbon Monoxide.

ERIC Educational Resources Information Center

Kolb, Kenneth E.; Kolb, Doris

1983-01-01

Carbon Monoxide obtained from coal may serve as the source for a wide variety of organic compounds. Several of these compounds are discussed, including phosgene, benzaldehyde, methanol, formic acid and its derivatives, oxo aldehydes, acrylic acids, and others. Commercial reactions of carbon monoxide are highlighted in a table. (JN)

Probing the Rate-Determining Step of the Claisen-Schmidt Condensation by Competition Reactions

ERIC Educational Resources Information Center

Mak, Kendrew K. W.; Chan, Wing-Fat; Lung, Ka-Ying; Lam, Wai-Yee; Ng, Weng-Cheong; Lee, Siu-Fung

2007-01-01

Competition experiments are a useful tool for preliminary study of the linear free energy relationship of organic reactions. This article describes a physical organic experiment for upper-level undergraduates to identify the rate-determining step of the Claisen-Schmidt condensation of benzaldehyde and acetophenone by studying the linear free…

A Better Sunscreen: Structural Effects on Spectral Properties

ERIC Educational Resources Information Center

Huck, Lawrence A.; Leigh, William J.

2010-01-01

A modification of the mixed-aldol synthesis of dibenzylideneacetone, prepared from acetone and benzaldehyde, is described wherein acetone is replaced with a series of cyclic ketones with ring sizes of 5-7 carbons. The structural variations in the resulting conjugated ketones produce regular variations in the UV-vis absorption spectra. The choice…

Multiple-division of self-propelled oil droplets through acetal formation.

PubMed

Banno, Taisuke; Kuroha, Rie; Miura, Shingo; Toyota, Taro

2015-02-28

We demonstrate a novel system that exhibits both self-propelled motion and division of micrometer-sized oil droplets induced by chemical conversion of the system components. Such unique dynamics were observed in an oil-in-water emulsion of a benzaldehyde derivative, an alkanol and a cationic surfactant at a low pH.

Response of western pine beetle, Dendroctonus brevicomis LeConte (Coleoptera: Curculionidae), to different release rates of nonhost angiosperm volatiles and verbenone

Treesearch

C.J. Fettig; S.R. McKelvey; C.P. Dabney; R.R. Borys; D.P.W. Huber

2009-01-01

A blend of eight nonhost angiosperm volatiles (benzyl alcohol, benzaldehyde, guaiacol, nonanal, salicylaldehyde, (E)-2-hexenal, (E)-2-hexen-1-ol and (Z)-2-hexen-1-ol) without [NAV] and with [NAVV] (–)-verbenone (4,6,6-trimethylbicyclo[3...

Augmenting the activity of monoterpenoid phenols against fungal pathogens using 2-hydroxy-4-methoxybenzaldehyde that target cell wall integrity

USDA-ARS?s Scientific Manuscript database

The aim of this study was to identify benzaldehydes to which the fungal cell wall integrity signaling mutants showed increased sensitivity. These compounds could then function as chemosensitizing agents in combination with monoterpenoid phenols, such as carvacrol or thymol, to enhance antifungal act...

High efficient photocatalytic selective oxidation of benzyl alcohol to benzaldehyde by solvothermal-synthesized ZnIn2S4 microspheres under visible light irradiation

NASA Astrophysics Data System (ADS)

Chen, Zhixin; Xu, Jingjing; Ren, Zhuyun; He, Yunhui; Xiao, Guangcan

2013-09-01

Hexagonal ZnIn2S4 samples have been synthesized by a solvothermal method. Their properties have been determined by X-ray diffraction, ultraviolet-visible-light diffuse reflectance spectra, field emission scanning electron microscopy, nitrogen adsorption-desorption and X-ray photoelectron spectra. These results demonstrate that ethanol solvent has significant influence on the morphology, optical and electronic nature for such marigold-like ZnIn2S4 microspheres. The visible light photocatalytic activities of the ZnIn2S4 have been evaluated by selective oxidation of benzyl alcohol to benzaldehyde using molecular oxygen as oxidant. The results show that 100% conversion along with >99% selectivity are reached over ZnIn2S4 prepared in ethanol solvent under visible light irradiation (λ>420 nm) of 2 h, but only 58% conversion and 57% yield are reached over ZnIn2S4 prepared in aqueous solvent. A possible mechanism of the high photocatalytic activity for selective oxidation of benzyl alcohol over ZnIn2S4 is proposed and discussed.

Structural, thermal and optical characterization of an organic NLO material--benzaldehyde thiosemicarbazone monohydrate single crystals.

PubMed

Santhakumari, R; Ramamurthi, K

2011-02-01

Single crystals of the organic NLO material, benzaldehyde thiosemicarbazone (BTSC) monohydrate, were grown by slow evaporation method. Solubility of BTSC monohydrate was determined in ethanol at different temperatures. The grown crystals were characterized by single crystal X-ray diffraction analysis to determine the cell parameters and by FT-IR technique to study the presence of the functional groups. Thermogravimetric and differential thermal analyses reveal the thermal stability of the crystal. UV-vis-NIR spectrum shows excellent transmission in the region of 200-1100 nm. Theoretical calculations were carried out to determine the linear optical constants such as extinction coefficient and refractive index. Further the optical nonlinearities of BTSC have been investigated by Z-scan technique with He-Ne laser radiation of wavelength 632.8 nm. Mechanical properties of the grown crystal were studied using Vickers microhardness tester. Second harmonic generation efficiency of the powdered BTSC monohydrate was tested using Nd:YAG laser and it is found to be ∼5.3 times that of potassium dihydrogen orthophosphate. Copyright © 2010 Elsevier B.V. All rights reserved.

A diffuse reflectance comparative study of benzil inclusion within microcrystalline cellulose and beta-cyclodextrin.

PubMed

Vieira Ferreira, Luis F; Ferreira Machado, Isabel; Da Silva, José P; Oliveira, Anabela S

2004-02-01

Diffuse reflectance and laser-induced techniques were used to study photochemical and photophysical processes of benzil adsorbed on two solid powdered supports, microcrystalline cellulose and [small beta]-cyclodextrin. In both substrates, a distribution of ground-state benzil conformers exists, largely dominated by skew conformations where the carbonyl groups are twisted one to the other. Room temperature phosphorescence was observed in air-equilibrated samples in both cases. The decay times vary greatly and the largest lifetime was obtained for benzil/[small beta]-cyclodextrin, showing that this host's cavity accommodates benzil well, enhancing its room temperature phosphorescence. Triplet-triplet absorption of benzil entrapped in cellulose was detected and benzil ketyl radical formation also occurred. With benzil included into [small beta]-cyclodextrin, and following laser excitation, benzoyl radicals were detected on the millisecond timescale. Product analysis and identification of laser-irradiated benzil samples in the two hosts clearly showed that the main degradation photoproducts were benzoic acid and benzaldehyde. The main differences were a larger benzoic acid/benzaldehyde ratio in the case of cellulose and the formation of benzyl alcohol in this support.

Regio- and Stereoselective Aliphatic-Aromatic Cross-Benzoin Reaction: Enzymatic Divergent Catalysis.

PubMed

Beigi, Maryam; Gauchenova, Ekaterina; Walter, Lydia; Waltzer, Simon; Bonina, Fabrizio; Stillger, Thomas; Rother, Dörte; Pohl, Martina; Müller, Michael

2016-09-19

The catalytic asymmetric synthesis of chiral 2-hydroxy ketones by using different thiamine diphosphate dependent enzymes, namely benzaldehyde lyase from Pseudomonas fluorescens (PfBAL), a variant of benzoylformate decarboxylase from Pseudomonas putida (PpBFD-L461A), branched-chain 2-keto acid decarboxylase from Lactococcus lactis (LlKdcA) and a variant of pyruvate decarboxylase from Acetobacter pasteurianus (ApPDC-E469G), was studied. Starting with the same set of substrates, substituted benzaldehydes in combination with different aliphatic aldehydes, PfBAL and PpBFD-L461A selectively deliver the (R)- and (S)-2-hydroxy-propiophenone derivatives, respectively. The (R)- and (S)-phenylacetylcarbinol (1-hydroxy-1-phenylacetone) derivatives are accessible in a similar way using LlKdcA and ApPDC-E469G, respectively. In many cases excellent stereochemical purities (>98 % enantiomeric excess) could be achieved. Hence, the regio- and stereochemistry of the product in the asymmetric aliphatic-aromatic cross-benzoin reaction can be controlled solely by choice of the appropriate enzyme or enzyme variant. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Growth and characterization of benzaldehyde 4-nitro phenyl hydrazone (BPH) single crystal: A proficient second order nonlinear optical material

NASA Astrophysics Data System (ADS)

Saravanan, M.; Abraham Rajasekar, S.

2016-04-01

The crystals (benzaldehyde 4-nitro phenyl hydrazone (BPH)) appropriate for NLO appliance were grown by the slow cooling method. The solubility and metastable zone width measurement of BPH specimen was studied. The material crystallizes in the monoclinic crystal system with noncentrosymmetric space group of Cc. The optical precision in the whole visible region was found to be excellent for non-linear optical claim. Excellence of the grown crystal is ascertained by the HRXRD and etching studies. Laser Damage Threshold and Photoluminescence studies designate that the grown crystal contains less imperfection. The mechanical behaviour of BPH sample at different temperatures was investigated to determine the hardness stability of the grown specimen. The piezoelectric temperament and the relative Second Harmonic Generation (for diverse particle sizes) of the material were also studied. The dielectric studies were executed at varied temperatures and frequencies to investigate the electrical properties. Photoconductivity measurement enumerates consummate of inducing dipoles due to strong incident radiation and also divulge the nonlinear behaviour of the material. The third order nonlinear optical properties of BPH crystals were deliberate by Z-scan method.

High efficient photocatalytic selective oxidation of benzyl alcohol to benzaldehyde by solvothermal-synthesized ZnIn{sub 2}S{sub 4} microspheres under visible light irradiation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chen, Zhixin, E-mail: czx@fzu.edu.cn; Instrumental Measurement and Analysis Center, Fuzhou University, Fuzhou 350002; Xu, Jingjing

Hexagonal ZnIn{sub 2}S{sub 4} samples have been synthesized by a solvothermal method. Their properties have been determined by X-ray diffraction, ultraviolet–visible-light diffuse reflectance spectra, field emission scanning electron microscopy, nitrogen adsorption–desorption and X-ray photoelectron spectra. These results demonstrate that ethanol solvent has significant influence on the morphology, optical and electronic nature for such marigold-like ZnIn{sub 2}S{sub 4} microspheres. The visible light photocatalytic activities of the ZnIn{sub 2}S{sub 4} have been evaluated by selective oxidation of benzyl alcohol to benzaldehyde using molecular oxygen as oxidant. The results show that 100% conversion along with >99% selectivity are reached over ZnIn{sub 2}S{sub 4}more » prepared in ethanol solvent under visible light irradiation (λ>420 nm) of 2 h, but only 58% conversion and 57% yield are reached over ZnIn{sub 2}S{sub 4} prepared in aqueous solvent. A possible mechanism of the high photocatalytic activity for selective oxidation of benzyl alcohol over ZnIn{sub 2}S{sub 4} is proposed and discussed. - Graphical abstract: Marigold-like ZnIn{sub 2}S{sub 4} microspheres were synthesized by a solvothermal method. The high visible photocatalytic activities of ZnIn{sub 2}S{sub 4} were evaluated by selective oxidation of benzyl alcohol to benzaldehyde under mild conditions. Display Omitted - Highlights: • Marigold-like ZnIn{sub 2}S{sub 4} microspheres were synthesized by a solvothermal method. • The solvents have a remarkably influence on the morphology and properties of samples. • It is the first time to apply ZnIn{sub 2}S{sub 4} for selective oxidation of benzyl alcohol. • ZnIn{sub 2}S{sub 4} shows high photocatalytic activity for selective oxidation of benzyl alcohol.« less

Molecular simulations of palladium catalysed hydrodeoxygenation of 2-hydroxybenzaldehyde using density functional theory.

PubMed

Verma, Anand Mohan; Kishore, Nanda

2017-09-27

The catalytic conversion of 2-hydroxybenzaldehyde (2-HB) is carried out numerically over a Pd(111) surface using density functional theory. The palladium catalyst surface is designed using a 12 atom monolayer and verified with the adsorption of phenol, benzene, anisole, guaiacol, and vanillin; it is found that the adsorption energies along with the adsorption configurations of phenol and benzene are in excellent agreement with the literature. The conversion of 2-HB over the Pd(111) catalyst surface is performed using four reaction schemes: (i) dehydrogenation of the formyl group followed by elimination of CO and association of hydrogen with 2-hydroxyphenyl to produce phenol, (ii) direct elimination of CHO from 2-HB followed by elimination of hydrogen from adsorbed CHO and association of hydrogen with 2-hydroxyphenyl to produce phenol, (iii) direct dehydroxylation of 2-HB followed by association of a hydrogen atom with 2-formylphenyl to produce benzaldehyde, and (iv) dehydrogenation of the hydroxyl group of 2-HB followed by elimination of an oxygen atom and association of a hydrogen atom with 2-formylphenyl to produce benzaldehyde. Along with the reaction mechanisms and their barrier heights, all reaction steps are considered for kinetic modelling in the temperature range 498-698 K with 50 K intervals. The rate constants, pre-exponential factors, and equilibrium constants of all elementary reaction steps are evaluated for each temperature. Kinetic analyses of the catalytic conversion of 2-HB over the Pd(111) surface suggests the production of phenol as an intermediate, instead of benzaldehyde, via dehydrogenation of the formyl group of 2-HB as a first elementary reaction step because of its low activation barrier and the high rate constant of the rate controlling step. Furthermore, the equilibrium constants of the rate controlling step in the production of phenol from 2-HB over the Pd(111) surface report a major fraction of the product in the product mixture even at a low temperature of 498 K.

Determination of NH2 concentration on 3-aminopropyl tri-ethoxy silane layers and cyclopropylamine plasma polymers by liquid-phase derivatization with 5-iodo 2-furaldehyde

NASA Astrophysics Data System (ADS)

Manakhov, Anton; Čechal, Jan; Michlíček, Miroslav; Shtansky, Dmitry V.

2017-08-01

The quantification of concentration of primary amines, e.g. in plasma polymerized layers is a very important task for surface analysis. However, the commonly used procedure, such as gas phase derivatization with benzaldehydes, shows several drawbacks, the most important of which are the side reaction effects. In the present study we propose and validate a liquid phase derivatization using 5-iodo 2-furaldehyde (IFA). It was demonstrated that the content of NH2 groups can be determined from the atomic concentrations measured by X-ray photoelectron spectroscopy (XPS), in particular from the ratio of I 3d and N 1s peak intensities. First, we demonstrate the method on a prototypical system such as 3-aminopropyl tri-ethoxy silane (APTES) layer. Here the XPS analysis carried out after reaction of APTES layer with IFA gives the fraction of primary amines (NH2/N) of 38.3 ± 7.9%. Comparing this value with that obtained by N 1s curve fitting of APTES layer giving 40.9 ± 9.5% of amine groups, it can be concluded that all primary amines were derivatized by reaction with IFA. The second system to demonstrate the method comprises cyclopropylamine (CPA) plasma polymers that were free from conjugated imines. In this case the method gives the NH2 fraction ∼8.5%. This value is closely matching the NH2/N ratio estimated by 4-trifluoromethyl benzaldehyde (TFBA) derivatization. The reaction of IFA with CPA plasma polymer exhibiting high density of conjugated imines revealed the NH2/N fraction of ∼10.8%. This value was significantly lower compared to 17.3% estimated by TFBA derivatization. As the overestimated density of primary amines measured by TFBA derivatization is probably related to the side reaction of benzaldehydes with conjugated imines, the proposed IFA derivatization of primary amines can be an alternative procedure for the quantification of surface amine groups.

Benzene formation in electronic cigarettes.

PubMed

Pankow, James F; Kim, Kilsun; McWhirter, Kevin J; Luo, Wentai; Escobedo, Jorge O; Strongin, Robert M; Duell, Anna K; Peyton, David H

2017-01-01

The heating of the fluids used in electronic cigarettes ("e-cigarettes") used to create "vaping" aerosols is capable of causing a wide range of degradation reaction products. We investigated formation of benzene (an important human carcinogen) from e-cigarette fluids containing propylene glycol (PG), glycerol (GL), benzoic acid, the flavor chemical benzaldehyde, and nicotine. Three e-cigarette devices were used: the JUULTM "pod" system (provides no user accessible settings other than flavor cartridge choice), and two refill tank systems that allowed a range of user accessible power settings. Benzene in the e-cigarette aerosols was determined by gas chromatography/mass spectrometry. Benzene formation was ND (not detected) in the JUUL system. In the two tank systems benzene was found to form from propylene glycol (PG) and glycerol (GL), and from the additives benzoic acid and benzaldehyde, especially at high power settings. With 50:50 PG+GL, for tank device 1 at 6W and 13W, the formed benzene concentrations were 1.9 and 750 μg/m3. For tank device 2, at 6W and 25W, the formed concentrations were ND and 1.8 μg/m3. With benzoic acid and benzaldehyde at ~10 mg/mL, for tank device 1, values at 13W were as high as 5000 μg/m3. For tank device 2 at 25W, all values were ≤~100 μg/m3. These values may be compared with what can be expected in a conventional (tobacco) cigarette, namely 200,000 μg/m3. Thus, the risks from benzene will be lower from e-cigarettes than from conventional cigarettes. However, ambient benzene air concentrations in the U.S. have typically been 1 μg/m3, so that benzene has been named the largest single known cancer-risk air toxic in the U.S. For non-smokers, chronically repeated exposure to benzene from e-cigarettes at levels such as 100 or higher μg/m3 will not be of negligible risk.

Metaflumizone is a novel sodium channel blocker insecticide.

PubMed

Salgado, V L; Hayashi, J H

2007-12-15

Metaflumizone is a novel semicarbazone insecticide, derived chemically from the pyrazoline sodium channel blocker insecticides (SCBIs) discovered at Philips-Duphar in the early 1970s, but with greatly improved mammalian safety. This paper describes studies confirming that the insecticidal action of metaflumizone is due to the state-dependent blockage of sodium channels. Larvae of the moth Spodoptera eridania injected with metaflumizone became paralyzed, concomitant with blockage of all nerve activity. Furthermore, tonic firing of abdominal stretch receptor organs from Spodoptera frugiperda was blocked by metaflumizone applied in the bath, consistent with the block of voltage-dependent sodium channels. Studies on native sodium channels, in primary-cultured neurons isolated from the CNS of the larvae of the moth Manduca sexta and on Para/TipE sodium channels heterologously expressed in Xenopus (African clawed frog) oocytes, confirmed that metaflumizone blocks sodium channels by binding selectively to the slow-inactivated state, which is characteristic of the SCBIs. The results confirm that metaflumizone is a novel sodium channel blocker insecticide.

Witting Reaction Using a Stabilized Phosphorus Ylid: An Efficient and Stereoselective Synthesis of Ethyl Trans-Cinnamate

ERIC Educational Resources Information Center

Speed, Traci J.; Mclntyre, Jean P.; Thamattoor, Dasan M.

2004-01-01

An instructive experiment for the synthesis of ethyl trans-cinnamate, a pleasant smelling ester used in perfumery and flavoring by the reaction of benzaldehyde with the stable ylid triphenylphosphorane is described. The synthesis, workup and characterization of trans-cinnamate may be accomplished in a single laboratory session with commonly…

Exploring the Stereochemistry of the Wittig Reaction: The Unexpected Influence of a Nominal Spectator Ion

ERIC Educational Resources Information Center

Hanson, John; Dasher, Bill; Scharrer, Eric; Hoyt, Tim

2010-01-01

Students in the second-semester organic chemistry laboratory perform a Wittig reaction between butylidenetriphenylphosphorane (an ylide) and benzaldehyde and determine the relative percentages of the cis and trans isomers of the 1-phenyl-1-pentene product. Because of the highly reactive nature of this unstabilized ylide, students are introduced to…

SUBCHRONIC SENSITIVITY OF ONE-, FOUR-, AND SEVEN-DAY-OLD FATHEAD MINNOW (PIMEPHALES PROMELAS) LARVAE TO FIVE TOXICANTS

EPA Science Inventory

The fathead minnow (pimephales promelas) larval survival and growth test was used to evaluate the relative sensitivity of 1-,4-, and 7-d-old larvae to five contaminants, KC1, NaC1, 1-octanol, carbaryl, and benzaldehyde. The no observable effect concentration (NOEC) for survival o...

A Guided-Inquiry Approach to the Sodium Borohydride Reduction and Grignard Reaction of Carbonyl Compounds

ERIC Educational Resources Information Center

Rosenberg, Robert E.

2007-01-01

The guided-inquiry approach is applied to the reactions of sodium borohydride and phenyl magnesium bromide with benzaldehyde, benzophenone, benzoic anhydride, and ethyl benzoate. Each team of four students receives four unknowns. Students identify the unknowns and their reaction products by using the physical state of the unknown, an…

Antibacterial anti-oxidant electroactive injectable hydrogel as self-healing wound dressing with hemostasis and adhesiveness for cutaneous wound healing.

PubMed

Zhao, Xin; Wu, Hao; Guo, Baolin; Dong, Ruonan; Qiu, Yusheng; Ma, Peter X

2017-04-01

Injectable self-healing hydrogel dressing with multifunctional properties including anti-infection, anti-oxidative and conductivity promoting wound healing process will be highly desired in wound healing application and its design is still a challenge. We developed a series of injectable conductive self-healed hydrogels based on quaternized chitosan-g-polyaniline (QCSP) and benzaldehyde group functionalized poly(ethylene glycol)-co-poly(glycerol sebacate) (PEGS-FA) as antibacterial, anti-oxidant and electroactive dressing for cutaneous wound healing. These hydrogels presented good self-healing, electroactivity, free radical scavenging capacity, antibacterial activity, adhesiveness, conductivity, swelling ratio, and biocompatibility. Interestingly, the hydrogel with an optimal crosslinker concentration of 1.5 wt% PEGS-FA showed excellent in vivo blood clotting capacity, and it significantly enhanced in vivo wound healing process in a full-thickness skin defect model than quaternized chitosan/PEGS-FA hydrogel and commercial dressing (Tegaderm™ film) by upregulating the gene expression of growth factors including VEGF, EGF and TGF-β and then promoting granulation tissue thickness and collagen deposition. Taken together, the antibacterial electroactive injectable hydrogel dressing prolonged the lifespan of dressing relying on self-healing ability and significantly promoted the in vivo wound healing process attributed to its multifunctional properties, meaning that they are excellent candidates for full-thickness skin wound healing. Copyright © 2017 Elsevier Ltd. All rights reserved.

[Studies on chemical constituents from Elaeocarpus sylvestris].

PubMed

Zhang, Hong-Chao; Shi, Hai-Ming

2008-10-01

To study the chemical constituents of Elaeocarpus sylvestris. The compounds were isolated by chromatographic methods and their structures were elucidated by physico-chemical properties and spectral analysis. Six compounds were isolated and identified as: 2-hydroxy-benzaldehyde (1), coniferyl alcohol (2), umbelliferone (3), scopoletin (4), beta-sitosterol (5), daucosterol (6). All above compounds are isolated from Elaeocarpus Genus for the first time.

Brown dog tick, Rhipicephalus sanguineus sensu lato, infestation ofsusceptible dog hosts is reduced by slow release of semiochemicalsfrom a less susceptible host

USDA-ARS?s Scientific Manuscript database

Domestic dog breeds are hosts for the tick Rhipicephalus sanguineus sensu lato, but infestation levels vary among breeds. Beagles are less susceptible to tick infestations than English cocker spaniels due to enhanced production of 2-hexanone and benzaldehyde that act as tick repellents. We report th...

Unexpectedly Facile Rh(I) Catalyzed Polymerization of Ethynylbenzaldehyde Type Monomers: Synthesis of Polyacetylenes Bearing Reactive and Easy Transformable Pendant Carbaldehyde Groups.

PubMed

Sedláček, Jan; Havelková, Lucie; Zedník, Jiří; Coufal, Radek; Faukner, Tomáš; Balcar, Hynek; Brus, Jiří

2017-04-01

The chain coordination polymerization of (ethynylarene)carbaldehydes with unprotected carbaldehyde groups, namely ethynylbenzaldehydes, 1-ethynylbenzene-3,5-dicarboxaldehyde, and 3-[(4-ethynylphenyl)ethynyl]benzaldehyde, is reported for the first time. Polymerization is catalyzed with various Rh(I) catalysts and yields poly(arylacetylene)s with one or two pendant carbaldehyde groups per monomeric unit. Surprisingly, the carbaldehyde groups of the monomers do not inhibit the polymerization unlike the carbaldehyde group of unsubstituted benzaldehyde that acts as a strong inhibitor of Rh(I) catalyzed polymerization of arylacetylenes. The inhibition ability of carbaldehyde groups in (ethynylarene)carbaldehydes seems to be eliminated owing to a simultaneous presence of unsaturated ethynyl groups in (ethynylarene)carbaldehydes. The reactive carbaldehyde groups make poly[(ethynylarene)carbaldehyde]s promising for functional appreciation via various postpolymerization modifications. The introduction of photoluminescence or chirality to poly(ethynylbenzaldehyde)s via quantitative modification of their carbaldehyde groups in reaction with either photoluminescent or chiral primary amines under formation of the polymers with Schiff-base-type pendant groups is given as an example. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

The mechanism of the formation of the hemiaminal and Schiff base from the benzaldehyde and triazole studied by means of the topological analysis of electron localisation function and catastrophe theory

NASA Astrophysics Data System (ADS)

Berski, Slawomir; Zbigniew Ciunik, Leszek

2015-04-01

The mechanisms of reaction of benzaldehyde (ald) with 4-amine-4H-1,2,4-triazole (4at), leading to Schiff base (Sch) and water, were investigated using topological analysis of the electron localisation function and catastrophe theory. Two reactions (synthesis of hemiaminal and synthesis of Schiff base) are represented by one catastrophe sequence: ald+4at: 1-14-[FF†F†FFTS1FF†F†FF†F†CF†]-2-9-[C†FFTS3F†F†FFF]-0:Sch+H2O with only fold (F) and cusp (C) catastrophes. The first reaction, in which a molecule of the hemiaminal is formed, consists of 14 steps separated by 13 catastrophes. The mechanism is non-concerted. The covalent bond C-N is formed after the formation of the O-H bond is terminated. The Schiff base formation through the water molecule elimination in the second reaction requires nine steps with eight catastrophes. The mechanism is non-concerted because first the C-O bond is broken and then the proton transfer occurs that results in the O-H bond creation.

Effect of crop development on biogenic emissions from plant populations grown in closed plant growth chambers

NASA Technical Reports Server (NTRS)

Batten, J. H.; Stutte, G. W.; Wheeler, R. M.

1995-01-01

The Biomass Production Chamber at John F. Kennedy Space Center is a closed plant growth chamber facility that can be used to monitor the level of biogenic emissions from large populations of plants throughout their entire growth cycle. The head space atmosphere of a 26-day-old lettuce (Lactuca sativa cv. Waldmann's Green) stand was repeatedly sampled and emissions identified and quantified using GC-mass spectrometry. Concentrations of dimethyl sulphide, carbon disulphide, alpha-pinene, furan and 2-methylfuran were not significantly different throughout the day; whereas, isoprene showed significant differences in concentration between samples collected in light and dark periods. Volatile organic compounds from the atmosphere of wheat (Triticum aestivum cv. Yecora Rojo) were analysed and quantified from planting to maturity. Volatile plant-derived compounds included 1-butanol, 2-ethyl-1-hexanol, nonanal, benzaldehyde, tetramethylurea, tetramethylthiourea, 2-methylfuran and 3-methylfuran. Concentrations of volatiles were determined during seedling establishment, vegetative growth, anthesis, grain fill and senescence and found to vary depending on the developmental stage. Atmospheric concentrations of benzaldehyde and nonanal were highest during anthesis, 2-methylfuran and 3-methylfuran concentrations were greatest during grain fill, and the concentration of the tetramethylurea peaked during senescence.

Visible Light Driven Benzyl Alcohol Dehydrogenation in a Dye-Sensitized Photoelectrosynthesis Cell

DOE Office of Scientific and Technical Information (OSTI.GOV)

Song, Wenjing; Vannucci, Aaron K.; Farnum, Byron H.

2014-06-27

Light-driven dehydrogenation of benzyl alcohol (BnOH) to benzaldehyde and hydrogen has been shown to occur in a dye-sensitized photoelectrosynthesis cell (DSPEC). In the DSPEC, the photoanode consists of mesoporous films of TiO2 nanoparticles or of core/shell nanoparticles with tin-doped In2O3 nanoparticle (nanoITO) cores and thin layers of TiO2 deposited by atomic layer deposition (nanoITO/TiO2). Metal oxide surfaces were coderivatized with both a ruthenium polypyridyl chromophore in excess and an oxidation catalyst. Chromophore excitation and electron injection were followed by cross-surface electron-transfer activation of the catalyst to RuIV=O2+, which then oxidizes benzyl alcohol to benzaldehyde. The injected electrons are transferred tomore » a Pt electrode for H2 production. The nanoITO/TiO2 core/shell structure causes a decrease of up to 2 orders of magnitude in back electron-transfer rate compared to TiO2. At the optimized shell thickness, sustained absorbed photon to current efficiency of 3.7% was achieved for BnOH dehydrogenation, an enhancement of ~10 compared to TiO2.« less

UV-Induced [2+2] Grafting-To Reactions for Polymer Modification of Cellulose.

PubMed

Conradi, Matthias; Ramakers, Gijs; Junkers, Thomas

2016-01-01

Benzaldehyde-functional cellulose paper sheets have been synthesized via tosylation of cellulose (Whatman No 5) followed by addition of p-hydroxy benzaldehyde. Via UV-induced Paterno-Büchi [2+2] cycloaddition reactions, these aldehyde functional surfaces are grafted with triallylcyanurate, trimethylolpropane allyl ether, and vinyl chloroacetate. In the following, allyl-functional polymers (poly(butyl acrylate), pBA, Mn = 6990 g mol(-1) , Đ = 1.12 and poly(N-isopropyl acrylamide), pNIPAAm, Mn = 9500 g mol(-1) , Đ = 1.16) synthesized via reversible addition fragmentation chain transfer polymerization are conjugated to the celloluse surface in a UV-induced grafting-to approach. With pBA, hydrophobic cellulose sheets are obtained (water contact angle 116°), while grafting of pNIPAAm allows for generation of "smart" surfaces, which are hydrophilic at room temperature, but that become hydrophobic when heated above the characteristic lower critical solution temperature (93° contact angle). The Paterno-Büchi reaction has been shown to be a versatile synthetic tool that also performs well in grafting-to approaches whereby its overall performance seems to be close to that of radical thiol-ene reactions. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

New hydrazones of ferulic acid: synthesis, characterization and biological activity.

PubMed

Wolszleger, Maria; Stan, Cătălina Daniela; Apotrosoaei, Maria; Vasincu, Ioana; Pânzariu, Andreea; Profire, Lenuţa

2014-01-01

The ferulic acid (4-hydroxy-3-methoxy-cinnamic acid) is a phenolic compound with important antioxidant effects and which nowadays is being extensively studied for his potential indications in inflammatory and neurodegenerative diseases, hypertension, atherosclerosis, etc. The synthesis of new ferulic acid compounds with potential antioxidant activity. The synthesis of the designed compounds was performed in several steps: (i) the obtaining of ferulic acid chloride by reacting of ferulic acid with thionyl chloride; (ii) the reaction between the ferulic acid chloride and hydrazine hydrate 98% to obtain the ferulic acid hydrazide; (iii) the condensation of ferrulic acid hydrazide with various benzaldehydes (2-hydroxy/3-hydroxy/4-hydroxy/2-nitro/3-nitro/4-nitro/2-methoxi/ 4-chloro/4-fluoro/4-bromo-benzaldehyde) resulting the correspond- ing hydrazones. The structure of the synthesized compounds was confirmed by FT-IR spectroscopy and the evaluation of antioxidant potential was achieved by determining the total antioxidant capacity and reducing power. In this study new hydrazones of ferulic acid have been synthesized, physic-chemical and spectral characterized. The evaluation of antioxidant potential using in vitro methods showed the favorable influence of the structural modulation on the antioxidant effects of ferulic acid.

Evaluation of the glycoside hydrolase activity of a Brettanomyces strain on glycosides from sour cherry (Prunus cerasus L.) used in the production of special fruit beers.

PubMed

Daenen, Luk; Sterckx, Femke; Delvaux, Freddy R; Verachtert, Hubert; Derdelinckx, Guy

2008-11-01

The glycoside hydrolase activity of Saccharomyces cerevisiae and Brettanomyces custersii was examined on sour cherry (Prunus cerasus L.) glycosides with bound volatile compounds. Refermentations by the beta-glucosidase-negative S. cerevisiae strains LD25 and LD40 of sour cherry juice-supplemented beer demonstrated only a moderate increase of volatiles. In contrast, the beta-glucosidase-positive B. custersii strain LD72 showed a more pronounced activity towards glycosides with aliphatic alcohols, aromatic compounds and terpenoid alcohols. Important contributors to sour cherry aroma such as benzaldehyde, linalool and eugenol were released during refermentation as shown by analytical tools. A gradually increasing release was observed during refermentations by B. custersii when whole sour cherries, sour cherry pulp or juice were supplemented in the beer. Refermentations with whole sour cherries and with sour cherry stones demonstrated an increased formation of benzyl compounds. Thus, amygdalin was partially hydrolysed, and a large part of the benzaldehyde formed was mainly reduced to benzyl alcohol and some further esterified to benzyl acetate. These findings demonstrate the importance and interesting role of certain Brettanomyces species in the production of fruit lambic beers such as 'Kriek'.

A Novel Oxidizing Reagent Based on Potassium Ferrate(VI)(1).

PubMed

Delaude, Lionel; Laszlo, Pierre

1996-09-06

A new, efficient preparation has been devised for potassium ferrate(VI) (K(2)FeO(4)). The ability of this high-valent iron salt for oxidizing organic substrates in nonaqueous media was studied. Using benzyl alcohol as a model, the catalytic activity of a wide range of microporous adsorbents was ascertained. Among numerous solid supports of the aluminosilicate type, the K10 montmorillonite clay was found to be best at achieving quantitative formation of benzaldehyde, without any overoxidation to benzoic acid. The roles of the various parameters (reaction time and temperature, nature of the solvent, method of preparation of the solid reagent) were investigated. The evidence points to a polar reaction mechanism. The ensuing procedure was applied successfully, at room temperature, to oxidation of a series of alcohols to aldehydes and ketones, to oxidative coupling of thiols to disulfides, and to oxidation of nitrogen derivatives. At 75 degrees C, the reagent has the capability of oxidizing both activated and nonactivated hydrocarbons. Toluene is turned into benzyl alcohol (and benzaldehyde). Cycloalkanes are also oxidized, in significant (30-40%) yields, to the respective cycloalkanols (and cycloalkanones). Thus, potassium ferrate, used in conjunction with an appropriate heterogeneous catalyst, is a strong and environmentally friendly oxidant.

Cu+ association to some Ph-X (X = OH, NH2, CHO, COOH, CF3) phenyl derivatives.: A comparison with Li+ complexes

NASA Astrophysics Data System (ADS)

Corral, Ines; Mo, Otilia; Yanez, Manuel

2006-09-01

The complexes of Cu+ with phenol, aniline, benzaldehyde, benzoic acid, and trifluromethyl-benzene were investigated through the use of MP2 and density functional theory (DFT) methods. Both harmonic vibrational frequencies and optimized geometries were obtained at the B3LYP/6-311G(d,p) and MP2(full)/6-311G(d,p) levels of theory. Final energies were obtained through single point B3LYP/6-311+G(3df,2p)//B3LYP/6-311G(d,p) calculations. The interactions of Cu+ with these aromatic compounds have a non-negligible covalent character, which clearly differentiate Cu+-complexes from the corresponding Li+-complexes. These dissimilarities are reflected in the geometries, binding energies and infrared spectra of the most stable adducts. For Li+ only conventional [pi]-complexes should be expected when interacting with aniline, while Cu+ attaches preferentially to the para carbon atom. For phenol, besides the conventional [pi]-complexes, a 12% of oxygen attached species are expected to be found upon Li+ association. Conversely, no oxygen attached species should be formed in reactions of phenol with Cu+. For benzoic acid and benzaldehyde, Li+ aligns with the dipole moment of the base, interacting exclusively with the carbonyl oxygen in the plane of the molecule. This is also the case in Cu+-benzoic acid complex, while in the Cu+-benzaldehyde complex the metal ion also interacts with the aromatic [pi]-system. Cu+ binding enthalpies (BEs) are systematically larger (about 1.3 times) than Li+ BEs. The covalent character of Cu+ interactions is associated with electron donations from bonding ([pi]) orbitals or lone-pairs of the base toward the 4s empty orbital of the metal and with back-donations from the occupied d orbitals of the metal toward antibonding ([pi]*) empty orbitals of the base. This non-negligible covalent character is also reflected in a rough correlation between the calculated Cu+ BEs and the available experimental proton affinities that does not exist for Li+ BEs.

Hydrogenation of benzaldehyde via electrocatalysis and thermal catalysis on carbon-supported metals

DOE Office of Scientific and Technical Information (OSTI.GOV)

Song, Yang; Sanyal, Udishnu; Pangotra, Dhananjai

Abstract Selective reduction of benzaldehyde to benzyl alcohol on C-supported Pt, Rh, Pd, and Ni in aqueous phase was conducted using either directly H2 (thermal catalytic hydrogenation, TCH) or in situ electrocatalytically generated hydrogen (electrocatalytic hydrogenation, ECH). In TCH, the intrinsic activity of the metals at room temperature and 1 bar H2 increased in the sequence Rh/C < Pt/C < Pd/C, while Ni/C is inactive at these conditions due to surface oxidation in the absence of cathodic potential. The reaction follows a Langmuir-Hinshelwood mechanism with the second hydrogen addition to the adsorbed hydrocarbon being the rate-determining step. All tested metalsmore » were active in ECH of benzaldehyde, although hydrogenation competes with the hydrogen evolution reaction (HER). The minimum cathodic potentials to obtain appreciable ECH rates were identical to the onset potentials of HER. Above this onset, the relative rates of H reacting to H2 and H addition to the hydrocarbon determines the selectivity to ECH and TCH. Accordingly, the selectivity of the metals towards ECH increases in the order Ni/C < Pt/C < Rh/C < Pd/C. Pd/C shows exceptionally high ECH selectivity due to its surprisingly low HER reactivity under the reaction conditions. Acknowledgements The authors would like to thank the groups of Hubert A. Gasteiger at the Technische Universität München of Jorge Gascon at the Delft University of Technology for advice and valuable discussions. The authors are grateful to Nirala Singh, Erika Ember, Gary Haller, and Philipp Rheinländer for fruitful discussions. We are also grateful to Marianne Hanzlik for TEM measurements and to Xaver Hecht and Martin Neukamm for technical support. Y.S. would like to thank the Chinese Scholarship Council for the financial support. The research described in this paper is part of the Chemical Transformation Initiative at Pacific Northwest National Laboratory (PNNL), conducted under the Laboratory Directed Research and Development Program at PNNL, a multiprogram national laboratory operated by Battelle for the U.S. Department of Energy.« less

Acute toxicity of nitrofurazone to channel catfish Ictalurus punctatus, and goldfish, Carassius auratus

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wise, M.L.; Stiebel, C.L.; Grizzle, J.M.

1987-01-01

Nitrofurazone (5-nitro-2-furaldehyde semicarbazone) is a nitrofuran, a group of organic compounds which have inhibitory activity against many Gram-negative and Gram-positive bacteria and against some protozoan parasites. Although not approved by the United States Food and Drug Administration for use with food fish, nitrofurazone has been found effective in fish against external and internal infections by various species of Aeromonas, Pseudomonas and myxobacteria and can be administered either as a food additive or as a bath treatment. Attempts to control the microsporidian parasite Pleistophora ovariae in golden shiners, Notemigonus crysoleucas, with nitrofurazone met with equivocal results. The following experiment was performedmore » to determine acute toxicity, including lesions, of nitrofurazone to channel catfish, Ictalurus punctatus, and goldfish, carassius auratus, fingerlings. Toxicity of nitrofurazone to channel catfish was determined with low dissolved oxygen concentrations (2 mg/L) to simulate conditions frequently encountered in channel catfish culture. Information abut toxic levels of drugs and the lesions occurring in exposed fish is important to determine the safety of treatment levels and the effects of toxic concentrations.« less

Efficient Electrochemical Synthesis, Antimicrobial and Antiinflammatory Activity of 2–amino-5-substituted- 1,3,4-oxadiazole Derivatives

PubMed Central

Kumar, S.; Srivastava, D. P.

2010-01-01

An efficient electrochemical method for the preparation of 2-amino-5-substituted-1,3,4-oxadiazoles (4a-k) at platinum anode through the electrooxidation of semicarbazone (3a-k) at controlled potential electrolysis has been reported in the present study. The electrolysis was carried out in the acetic acid solvent and lithium perchlorate was used as supporting electrolyte. The products were characterized by IR,1H-NMR,13C-NMR, mass spectra and elemental analysis. The synthesized compounds were screened for their in vitro growth inhibiting activity against different strains of bacteria viz., Klebsilla penumoniae, Escherichia coli, Bassilus subtilis and Streptococcus aureus and antifungal activity against Aspergillus niger and Crysosporium pannical and results have been compared with the standard antibacterial streptomycin and antifungal griseofulvin. Compounds exhibits significant antibacterial activity and antifungal activity. Compounds 4a and g exhibited equal while 4c, d, i and j slightly less antibacterial activity than standard streptomycin. Compounds 4a and g exhibited equal while 4b, c, d, f and i displayed slightly less antifungal activity than standard griseofulvins. PMID:21218056

Incorporation of an aldehyde function in oligonucleotides.

PubMed

Tilquin, J M; Dechamps, M; Sonveaux, E

2001-01-01

A nucleotide-like phosphoramidite building block that has the nucleic base replaced by the tert-butyldimethylsilyl-protected styrene glycol was synthesized. After the automatic synthesis of an oligonucleotide incorporating this synthon, the benzaldehyde function was generated by fluoride deprotection and oxidation by sodium periodate. In a similar manner, an oligonucleotide where a nucleic base was replaced by the (CH2)8CH=O chain was synthesized and conjugated with biotin derivatives.

Aroma characterization of chinese rice wine by gas chromatography-olfactometry, chemical quantitative analysis, and aroma reconstitution.

PubMed

Chen, Shuang; Xu, Yan; Qian, Michael C

2013-11-27

The aroma profile of Chinese rice wine was investigated in this study. The volatile compounds in a traditional Chinese rice wine were extracted using Lichrolut EN and further separated by silica gel normal phase chromatography. Seventy-three aroma-active compounds were identified by gas chromatography-olfactometry (GC-O) and gas chromatography-mass spectrometry (GC-MS). In addition to acids, esters, and alcohols, benzaldehyde, vanillin, geosmin, and γ-nonalactone were identified to be potentially important to Chinse rice wine. The concentration of these aroma-active compounds in the Chinese rice wine was further quantitated by combination of four different methods, including headsapce-gas chromatography, solid phase microextraction-gas chromatography (SPME)-GC-MS, solid-phase extraction-GC-MS, and SPME-GC-pulsed flame photometric detection (PFPD). Quantitative results showed that 34 aroma compounds were at concentrations higher than their corresponding odor thresholds. On the basis of the odor activity values (OAVs), vanillin, dimethyl trisulfide, β-phenylethyl alcohol, guaiacol, geosmin, and benzaldehyde could be responsible for the unique aroma of Chinese rice wine. An aroma reconstitution model prepared by mixing 34 aroma compounds with OAVs > 1 in an odorless Chinese rice wine matrix showed a good similarity to the aroma of the original Chinese rice wine.

Nutritional value and volatile compounds of black cherry (Prunus serotina) seeds.

PubMed

García-Aguilar, Leticia; Rojas-Molina, Alejandra; Ibarra-Alvarado, César; Rojas-Molina, Juana I; Vázquez-Landaverde, Pedro A; Luna-Vázquez, Francisco J; Zavala-Sánchez, Miguel A

2015-02-17

Prunus serotina (black cherry), commonly known in Mexico as capulín, is used in Mexican traditional medicine for the treatment of cardiovascular, respiratory, and gastrointestinal diseases. Particularly, P. serotina seeds, consumed in Mexico as snacks, are used for treating cough. In the present study, nutritional and volatile analyses of black cherry seeds were carried out to determine their nutraceutical potential. Proximate analysis indicated that P. serotina raw and toasted seeds contain mostly fat, followed by protein, fiber, carbohydrates, and ash. The potassium content in black cherry raw and toasted seeds is high, and their protein digestibility-corrected amino acid scores suggest that they might represent a complementary source of proteins. Solid phase microextraction and gas chromatography/flame ionization detection/mass spectrometry analysis allowed identification of 59 and 99 volatile compounds in the raw and toasted seeds, respectively. The major volatile compounds identified in raw and toasted seeds were 2,3-butanediol and benzaldehyde, which contribute to the flavor and odor of the toasted seeds. Moreover, it has been previously demonstrated that benzaldehyde possesses a significant vasodilator effect, therefore, the presence of this compound along with oleic, linoleic, and α-eleostearic fatty acids indicate that black cherry seeds consumption might have beneficial effects on the cardiovascular system.

Tungstocobaltate-pillared layered double hydroxides: Preparation, characterization, magnetic and catalytic properties

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wei Xiaocui; Baicheng College of Higher Medicine, Baicheng 137000; Fu Youzhi

2008-06-15

A new polyoxometalate anion-pillared layered double hydroxide (LDH) was prepared by aqueous ion exchange of a Mg-Al LDH precursor in nitrate form with the tungstocobaltate anions [CoW{sub 12}O{sub 40}]{sup 5-}. The physicochemical properties of the product were characterized by the methods of powder X-ray diffraction, elemental analysis, infrared spectroscopy, thermogravimetric analysis and cyclic voltammetry. It was confirmed that [CoW{sub 12}O{sub 40}]{sup 5-} was intercalated between the brucite-type layers of the LDHs without a change in the structure. Magnetic measurement shows the occurrence of antiferromagnetic interactions between the magnetic centers. The investigation of catalytic performance for this sample exhibits high activitymore » for the oxidation of benzaldehyde by hydrogen peroxide. - Graphical abstract: A tungstocobaltate anion [CoW{sub 12}O{sub 40}]{sup 5-} pillared layered double hydroxide (LDH) was prepared by aqueous ion exchange with a Mg-Al LDH precursor in nitrate form, demonstrating that [CoW{sub 12}O{sub 40}]{sup 5-} was intercalated between the brucite-type layers of the LDHs without change in structure. Magnetic measurement shows the occurrence of antiferromagnetic interactions between the magnetic centers. The investigation of catalytic performance for this sample exhibits high activity for the oxidation of benzaldehyde by hydrogen peroxide.« less

A specific affinity reagent to distinguish aldehyde dehydrogenases and oxidases. Enzymes catalyzing aldehyde oxidation in an adult moth

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tasayco, M.L.; Prestwich, G.D.

1990-02-25

Aldehyde dehydrogenase (ALDH) and oxidase (AO) enzymes from the tissue extracts of male and female tobacco budworm moth (Heliothis virescens) were identified after electrophoretic protein separation. AO activity was visualized using formazan- or horseradish peroxidase-mediated staining coupled to the AO-catalyzed oxidation of benzaldehyde. A set of six soluble AO enzymes with isoelectric points from pI 4.6 to 5.3 were detected primarily in the antennal extracts. Partially purified antennal AO enzymes also oxidized both (Z)-9-tetradecenal and (Z)-11-hexadecenal, the two major pheromone components of this moth. ALDH activity was detected using a tritium-labeled affinity reagent based on a known irreversible inhibitor ofmore » this enzyme. This labeled vinyl ketone, (3H)(Z)-1,11-hexadecadien-3-one, was synthesized and used to covalently modify the soluble ALDH enzymes from tissue extracts. Molecular subunits of potential ALDH enzymes were visualized in the fluorescence autoradiograms of sodium dodecyl sulfate-polyacrylamide gel electrophoresis-separated proteins of the antenna, head, and leg tissues. Covalent modification of these protein subunits decreased specifically in the presence of excess pheromone aldehyde or benzaldehyde. Labeled vinyl ketones are thus novel tools for the identification of molecular subunits of ALDH enzymes.« less

Pulsed corona discharge oxidation of aqueous carbamazepine micropollutant.

PubMed

Ajo, Petri; Krzymyk, Ewelina; Preis, Sergei; Kornev, Iakov; Kronberg, Leif; Louhi-Kultanen, Marjatta

2016-08-01

The anti-epileptic drug carbamazepine (CBZ) receives growing attention due to slow biodegradation and inherent accumulation in the aquatic environment. The application of a gas-phase pulsed corona discharge (PCD) was investigated to remove CBZ from synthetic solutions and spiked wastewater effluent from a municipal wastewater treatment facility. The treated water was showered between high voltage (HV) wires and grounded plate electrodes, to which ultra-short HV pulses were applied. CBZ was readily oxidized and 1-(2-benzaldehyde)-4-hydroquinazoline-2-one (BQM) and 1-(2-benzaldehyde)-4-hydro-quinazoline-2,4-dione (BQD) were identified as the most abundant primary transformation products, which, contrary to CBZ ozonation data available in the literature, were further easily oxidized with PCD: BQM and BQD attributed to only a minor portion of the target compound oxidized. In concentrations commonly found in wastewater treatment plant effluents (around 5 µg L(-1)), up to 97% reduction in CBZ concentration was achieved at mere 0.3 kW h m(-3) energy consumption, and over 99.9% was removed at 1 kW h m(-3). The PCD application proved to be efficient in the removal of both the parent substance and its known transformation products, even with the competing reactions in the complex composition of wastewater.

Growth and characterization of novel organic 3-Hydroxy Benzaldehyde-N-methyl 4 Stilbazolium Tosylate crystals for NLO applications.

PubMed

Jagannathan, K; Umarani, P; Ratchagar, V; Ramesh, V; Kalainathan, S

2016-01-15

The 3-Hydroxy Benzaldehyde-N-methyl 4-Stilbazolium Tosylate (3- HBST) is a new organic NLO crystal and it is a new derivative in stilbazolium tosylate family. In this work we have synthesized 3-HBST and the single crystal was grown by conventional slow cooling method. The structure and lattice parameters of the grown crystal were determined by the single crystal X-ray diffraction (XRD) technique and it is exhibiting good crystalline nature which is observed from the powder XRD. In order to check the crystalline quality the rocking curve was recorded using multi crystal X-ray diffractometer. The functional groups were identified from both FTIR and NMR spectral analyses. The π-π* and n-π* optical transition energy levels were estimated from the absorption peaks. The NLO property was confirmed by measuring relative SHG efficiency by Kurtz powder test; it shows 24 times higher SHG efficiency than that of urea. In order to test the mechanical stability the Vickers and Knoop micro hardness measurement were carried out and found that the micro hardness number decreases with increasing load. The melting point was determined from Differential Scanning Colorimetry (DSC). Copyright © 2015 Elsevier B.V. All rights reserved.

Characterization of the Key Aroma Compounds in Proso Millet Wine Using Headspace Solid-Phase Microextraction and Gas Chromatography-Mass Spectrometry.

PubMed

Liu, Jingke; Zhao, Wei; Li, Shaohui; Zhang, Aixia; Zhang, Yuzong; Liu, Songyan

2018-02-20

The volatile compounds in proso millet wine were extracted by headspace solid-phase microextraction (85 μm polyacrylate (PA), 100 μm polydimethylsiloxane (PDMS), 75 μm Carboxen (CAR)/PDMS, and 50/30 μm divinylbenzene (DVB)/CAR/PDMS fibers), and analyzed using gas chromatography-mass spectrometry; the odor characteristics and intensities were analyzed by the odor activity value (OAV). Different sample preparation factors were used to optimize this method: sample amount, extraction time, extraction temperature, and content of NaCl. A total of 64 volatile compounds were identified from the wine sample, including 14 esters, seven alcohols, five aldehydes, five ketones, 12 benzene derivatives, 12 hydrocarbons, two terpenes, three phenols, two acids, and two heterocycles. Ethyl benzeneacetate, phenylethyl alcohol, and benzaldehyde were the main volatile compounds found in the samples. According to their OAVs, 14 volatile compounds were determined to be odor-active compounds (OAV > 1), and benzaldehyde, benzeneacetaldehyde, 1-methyl-naphthalene, 2-methyl-naphthalene, and biphenyl were the prominent odor-active compounds (OAV > 50), having a high OAV. Principal component analysis (PCA) showed the difference of distribution of the 64 volatile compounds and 14 odor-active compounds with four solid-phase microextraction (SPME) fibers.

Contrasting metabolic profiles of tasty Andean varieties of tomato fruit in comparison with commercial ones.

PubMed

D'Angelo, Matilde; Zanor, María I; Sance, María; Cortina, Pablo R; Boggio, Silvana B; Asprelli, Pablo; Carrari, Fernando; Santiago, Ana N; Asís, Ramón; Peralta, Iris E; Valle, Estela M

2018-02-02

The fruits of most commercial tomato cultivars (Solanum lycopersicum L.) are deficient in flavour. In contrast, traditional 'criollo' tomato varieties are appreciated for fruit of excellent organoleptic quality. Small farmers from the Andean valleys in Argentina have maintained their own tomato varieties, which were selected mainly for flavour. This work aims to correlate the chemical composition of the fruit with the sensory attributes of eight heirloom tomato varieties. The long-term goal is to identify potential candidate genes capable of altering the chemicals involved in flavour. A sensory analysis was conducted and the metabolomics of fruit were determined. The data revealed that defined tomato aroma and sourness correlated with citrate and several volatile organic compounds (VOC), such as α-terpineol, p-menth-1-en-9-al, linalool and 3,6-dimethyl-2,3,3a,4,5,7a-hexahydrobenzofuran (DMHEX), a novel volatile recently identified in tomato. Two sensory attributes - sweetness and a not-acidic taste - correlated with the characteristic tomato taste, and also with fructose, glucose, and two VOCs, benzaldehyde, and 2-methyl-2-octen-4-one. These data provide new evidence of the complex chemical combination that induced the flavour and aroma of the good-tasting 'criollo' tomato fruit. That is, the compounds that correlated with defined tomato aroma and acidic taste did not correlate with sweetness, or with characteristic tomato taste. © 2018 Society of Chemical Industry. © 2018 Society of Chemical Industry.

A deep transcriptomic analysis of pod development in the vanilla orchid (Vanilla planifolia).

PubMed

Rao, Xiaolan; Krom, Nick; Tang, Yuhong; Widiez, Thomas; Havkin-Frenkel, Daphna; Belanger, Faith C; Dixon, Richard A; Chen, Fang

2014-11-07

Pods of the vanilla orchid (Vanilla planifolia) accumulate large amounts of the flavor compound vanillin (3-methoxy, 4-hydroxy-benzaldehyde) as a glucoside during the later stages of their development. At earlier stages, the developing seeds within the pod synthesize a novel lignin polymer, catechyl (C) lignin, in their coats. Genomic resources for determining the biosynthetic routes to these compounds and other flavor components in V. planifolia are currently limited. Using next-generation sequencing technologies, we have generated very large gene sequence datasets from vanilla pods at different times of development, and representing different tissue types, including the seeds, hairs, placental and mesocarp tissues. This developmental series was chosen as being the most informative for interrogation of pathways of vanillin and C-lignin biosynthesis in the pod and seed, respectively. The combined 454/Illumina RNA-seq platforms provide both deep sequence coverage and high quality de novo transcriptome assembly for this non-model crop species. The annotated sequence data provide a foundation for understanding multiple aspects of the biochemistry and development of the vanilla bean, as exemplified by the identification of candidate genes involved in lignin biosynthesis. Our transcriptome data indicate that C-lignin formation in the seed coat involves coordinate expression of monolignol biosynthetic genes with the exception of those encoding the caffeoyl coenzyme A 3-O-methyltransferase for conversion of caffeoyl to feruloyl moieties. This database provides a general resource for further studies on this important flavor species.

(Methylthio)phenol semiochemicals are exploited by deceptive orchids as sexual attractants for Campylothynnus thynnine wasps.

PubMed

Bohman, Björn; Phillips, Ryan D; Flematti, Gavin R; Peakall, Rod

2018-04-01

Until recently, (methylthio)phenols as natural products had only been reported from bacteria. Now, four representatives of this class of sulfurous aromatic compounds have been discovered as semiochemicals in the orchid Caladenia crebra, which secures pollination by sexual deception. In this case, field bioassays confirmed that a 10:1 blend of 2-(methylthio)benzene-1,4-diol (1) and 4-hydroxy-3-(methylthio)benzaldehyde (2) sexually attracts the male thynnine wasp Campylothynnus flavopictus (Tiphiidae:Thynnineae), the exclusive pollinator of C. crebra. Here we show with field bioassays that another undescribed species of Campylothynnus (sp. A) is strongly sexually attracted to a 1:1 blend of compounds 1 and 2, which elicits very high attempted copulation rates (88%). We also confirm that this Campylothynnus species is a pollinator of Caladenia attingens subsp. attingens. Chemical analysis of the flowers of this orchid revealed two (methylthio)phenols, compound 2 and 2-(methylthio)phenol (3), as candidate semiochemicals involved in pollinator attraction. Thus, (methylthio)phenols are likely to be more widely used than presently known. The confirmation of this Campylothynnus as a pollinator of C. attingens subsp. attingens at our study sites was unexpected, since elsewhere this orchid is pollinated by a different thynnine wasp (Thynnoides sp). In general, sexually deceptive Caladenia only use a single species of pollinator, and as such, this unusual case may offer a tractable study system for understanding the chemical basis of pollinator switching in sexually deceptive orchids. Copyright © 2017 Elsevier B.V. All rights reserved.

Preparing Students for Research: Synthesis of Substituted Chalcones as a Comprehensive Guided-Inquiry Experience

NASA Astrophysics Data System (ADS)

Vyvyan, James R.; Pavia, Donald L.; Lampman, Gary M.; Kriz, George S., Jr.

2002-09-01

A guided inquiry experiment involving the synthesis and characterization of substituted benzalacetophenones (chalcones) is described. The chalcones are produced in the aldol condensation of substituted benzaldehydes with substituted acetophenones. Each student is assigned a different target chalcone and conducts online and printed literature searches on the target. After completing the synthesis and purification of their product, the students compare their data with those found in the literature.

Chemoselective N-heterocyclic carbene-catalyzed cross-benzoin reactions: importance of the fused ring in triazolium salts.

PubMed

Langdon, Steven M; Wilde, Myron M D; Thai, Karen; Gravel, Michel

2014-05-28

Morpholinone- and piperidinone-derived triazolium salts are shown to catalyze highly chemoselective cross-benzoin reactions between aliphatic and aromatic aldehydes. The reaction scope includes ortho-, meta-, and para-substituted benzaldehyde derivatives with a range of electron-donating and -withdrawing groups as well as branched and unbranched aliphatic aldehydes. Catalytic loadings as low as 5 mol % give excellent yields in these reactions (up to 99%).

Tissue Engineered Testicular Prostheses With Prolonged Testosterone Release

DTIC Science & Technology

2008-12-01

inguinal lymph nodes from a leaking testicular prosthesis: a cause for chronic fatigue? BJU Int., 86, 1090. Ebert, T ., F. Jockenhovel, A. Morales, and R ...NaOH, hydroxyproline oxidation was initiated by adding 1 ml chloramine- T to the extract. After gentle mixing and incubation for 20 minutes, the...chloramine- T was destroyed by addition of 1 ml perchloric acid to each tube. Finally, 1 ml p- dimethylamino-benzaldehyde solution was added and

Exploiting the CNC side chain in heterocyclic rearrangements: synthesis of 4(5)-acylamino-imidazoles.

PubMed

Piccionello, Antonio Palumbo; Buscemi, Silvestre; Vivona, Nicolò; Pace, Andrea

2010-08-06

A new variation on the Boulton-Katritzky reaction is reported, namely, involving use of a CNC side chain. A novel Montmorillonite-K10 catalyzed nonreductive transamination of a 3-benzoyl-1,2,4-oxadiazole afforded a 3-(alpha-aminobenzyl)-1,2,4-oxadiazole, which was condensed with benzaldehydes to afford the corresponding imines. In the presence of strong base, these imines underwent Boulton-Katritzky-type rearrangement to afford novel 4(5)-acylaminoimidazoles.

Human class II (pi) alcohol dehydrogenase has a redox-specific function in norepinephrine metabolism.

PubMed Central

Mårdh, G; Dingley, A L; Auld, D S; Vallee, B L

1986-01-01

Studies of the function of human alcohol dehydrogenase (ADH) have revealed substrates that are virtually unique for class II ADH (pi ADH). It catalyzes the formation of the intermediary glycols of norepinephrine metabolism, 3,4-dihydroxyphenylglycol and 4-hydroxy-3-methoxyphenylglycol, from the corresponding aldehydes 3,4-dihydroxymandelaldehyde and 4-hydroxy-3-methoxymandelaldehyde with Km values of 55 and 120 microM and kcat/Km ratios of 14,000 and 17,000 mM-1 X min-1; these are from 60- to 210-fold higher than those obtained with class I ADH isozymes. The catalytic preference of class II ADH also extends to benzaldehydes. The kcat/Km values for the reduction of benzaldehyde, 3,4-dihydroxybenzaldehyde and 4-hydroxy-3-methoxybenzaldehyde by pi ADH are from 9- to 29-fold higher than those for a class I isozyme, beta 1 gamma 2 ADH. Furthermore, the norepinephrine aldehydes are potent inhibitors of alcohol (ethanol) oxidation by pi ADH. The high catalytic activity of pi ADH-catalyzed reduction of the aldehydes in combination with a possible regulatory function of the aldehydes in the oxidative direction leads to essentially "unidirectional" catalysis by pi ADH. These features and the presence of pi ADH in human liver imply a physiological role for pi ADH in the degradation of circulating epinephrine and norepinephrine. PMID:3466164

Cd(II) and Zn(II) complexes of two new hexadentate Schiff base ligands derived from different aldehydes and ethanol amine; X-ray crystal structure, IR and NMR spectroscopy studies

NASA Astrophysics Data System (ADS)

Golbedaghi, Reza; Rezaeivala, Majid; Albeheshti, Leila

2014-11-01

Four new [Cd(H2L1)(NO3)]ClO4 (1), [Zn(H2L1)](ClO4)2 (2), [Cd(H2L2)(NO3)]ClO4 (3), and [Zn(H2L2)](ClO4)2 (4), complexes were prepared by the reaction of two new Schiff base ligands and Cd(II) and Zn(II) metal ions in equimolar ratios. The ligands H2L1 and H2L2 were synthesized by reaction of 2-[2-(2-formyl phenoxy)ethoxy]benzaldehyde and/or 2-[2-(3-formyl phenoxy)propoxy]benzaldehyde and ethanol amine and characterized by IR, 1H and 13C NMR spectroscopy. All complexes were characterized by IR, 1H and 13C NMR, COSY, and elemental analysis. Also, the complex 1 was characterized by X-ray in addition to the above methods. The X-ray crystal structure of compound 1 showed that all nitrogen and oxygen atoms of ligand (N2O4) and a molecule of nitrate with two donor oxygen atom have been coordinated to the metal ion and the Cd(II) ion is in an eight-coordinate environment that is best described as a distorted dodecahedron geometry.

Seasonal evaluation of disinfection by-products throughout two full-scale drinking water treatment plants.

PubMed

Zhong, Xin; Cui, Chongwei; Yu, Shuili

2017-07-01

Carbonyl compounds can occur alpha-hydrogens or beta-diketones substitution reactions with disinfectants contributed to halogenated by-products formation. The objective of this research was to study the occurrence and fate of carbonyl compounds as ozonation by-products at two full-scale drinking water treatment plants (DWTPs) using different disinfectants for one year. The quality of the raw water used in both plants was varied according to the season. The higher carbonyl compounds concentrations were found in raw water in spring. Up to 15 (as the sum of both DWTPs) of the 24 carbonyl compounds selected for this work were found after disinfection. The dominant carbonyl compounds were formaldehyde, glyoxal, methyl-glyoxal, fumaric, benzoic, protocatechuic and 3-hydroxybenzoic acid at both DWTPs. In the following steps in each treatment plant, the concentration patterns of these carbonyl compounds differed depending on the type of disinfectant applied. Benzaldehyde was the only aromatic aldehyde detected after oxidation with ozone in spring. As compared with DWTP 1, five new carbonyl compounds were formed (crotonaldehyde, benzaldehyde, formic, oxalic and malonic acid) disinfection by ozone, and the levels of the carbonyl compounds increased. In addition, pre-ozonation (PO) and main ozonation (OZ) increased the levels of carbonyl compounds, however coagulation/flocculation (CF), sand filtration (SF) and granular activated carbon filtration (GAC) decreased the levels of carbonyl compounds. Copyright © 2017 Elsevier Ltd. All rights reserved.

Exploring of bioactive compounds in essential oil acquired from the stem and root derivatives of Hypericum triquetrifolium callus cultures.

PubMed

Tahir, Nawroz Abdul-Razzak; Azeez, Hoshyar Abdullah; Muhammad, Kadhm Abdullah; Faqe, Shewa Anwer; Omer, Dlshad Ali

2017-12-25

The chemical profile of the essential oil of callus and cell suspension cultures derivatives from stem and root of Hypericum triquetrifolium were explored by ITEX/GC-MS. The major constituents for stem derivatives were undecane (78.44%) and 2,4,6-trimethyl-octane (9.74%) for fresh calli, 2,4-dimethyl-benzaldehyde (46.94%), 2,3-dimethyl-undecane (28.39%), 2,4-dimethyl-1-hexene (10.17%), 1,2-oxolinalool (3.64%) and limonene (3.55%) for dry calli and undecane (61.24%), octane, 2,4,6-trimethyl- (16.73%), nonane, 3-methyl-(3.74%), 2,5-diphenyl-benzoquinone (3.70%) and limonene (3.60%) for cell suspension. However, for root derivatives, the dominated components were: undecane (49.94%), eucalyptol (12.07%), limonene (9.98%), toluene (9.03%) and 3-methyl-nonane (4.29%) for fresh calli, 2,4-dimethyl-benzaldehyde (29.80%), 1,1-dimethylethyl-cyclohexane (14.99%), 3-methyl-pentanal (14.99%), undecane (10.04%), beta-terpinyl acetate (8.60%), 1,2-oxolinalool (6.27%) and 2-pentyl-furan (4.09%) for dry calli, undecane (52.38%), 2,4,6-trimethyl-octane (13.81%), 3-methyl-nonane (5.73%), toluene (4.82%) and limonene (4.57%) for cell suspension derivative in root. The attained outcomes indicated that the alkane, aldehyde and monoterpene fractions dominated the chemical composition of essential oils.

Field observations of volatile organic compound (VOC) exchange in red oaks

NASA Astrophysics Data System (ADS)

Cappellin, Luca; Algarra Alarcon, Alberto; Herdlinger-Blatt, Irina; Sanchez, Juaquin; Biasioli, Franco; Martin, Scot T.; Loreto, Francesco; McKinney, Karena A.

2017-03-01

Volatile organic compounds (VOCs) emitted by forests strongly affect the chemical composition of the atmosphere. While the emission of isoprenoids has been largely characterized, forests also exchange many oxygenated VOCs (oVOCs), including methanol, acetone, methyl ethyl ketone (MEK), and acetaldehyde, which are less well understood. We monitored total branch-level exchange of VOCs of a strong isoprene emitter (Quercus rubra L.) in a mixed forest in New England, where canopy-level fluxes of VOCs had been previously measured. We report daily exchange of several oVOCs and investigated unknown sources and sinks, finding several novel insights. In particular, we found that emission of MEK is linked to uptake of methyl vinyl ketone (MVK), a product of isoprene oxidation. The link was confirmed by corollary experiments proving in vivo detoxification of MVK, which is harmful to plants. Comparison of MEK, MVK, and isoprene fluxes provided an indirect indication of within-plant isoprene oxidation. Furthermore, besides confirming bidirectional exchange of acetaldehyde, we also report for the first time direct evidence of benzaldehyde bidirectional exchange in forest plants. Net emission or deposition of benzaldehyde was found in different periods of measurements, indicating an unknown foliar sink that may influence atmospheric concentrations. Other VOCs, including methanol, acetone, and monoterpenes, showed clear daily emission trends but no deposition. Measured VOC emission and deposition rates were generally consistent with their ecosystem-scale flux measurements at a nearby site.

Tomato root growth, gravitropism, and lateral development: correlation with auxin transport

NASA Technical Reports Server (NTRS)

Muday, G. K.; Haworth, P.

1994-01-01

Tomato (Lycopersicon esculentum, Mill.) roots were analyzed during growth on agar plates. Growth of these roots was inhibited by the auxin transport inhibitors naphthylphthalamic acid (NPA) and semicarbazone derivative I (SCB-1). The effect of auxin transport inhibitors on root gravitropism was analyzed by measurement of the angle of gravitropic curvature after the roots were reoriented 90 degrees from the vertical. NPA and SCB-1 abolished both the response of these roots to gravity and the formation of lateral roots, with SCB-1 being the more effective at inhibition. Auxins also inhibited root growth. Both auxins tested has a slight effect on the gravity response, but this effect is probably indirect, since auxins reduced the growth rate. Auxins also stimulated lateral root growth at concentration where primary root growth was inhibited. When roots were treated with both IAA and NPA simultaneously, a cumulative inhibition of root growth was found. When both compounds were applied together, analysis of gravitropism and lateral root formation indicated that the dominant effect was exerted by auxin transport inhibitors. Together, these data suggest a model for the role of auxin transport in controlling both primary and lateral root growth.

Design, structural and spectroscopic elucidation of new nitroaromatic carboxylic acids and semicarbazones for the in vitro screening of anti-leishmanial activity

NASA Astrophysics Data System (ADS)

Dias, L. C.; de Lima, G. M.; Pinheiro, C. B.; Rodrigues, B. L.; Donnici, C. L.; Fujiwara, R. T.; Bartholomeu, D. C.; Ferreira, R. A.; Ferreira, S. R.; Mendes, T. A. O.; da Silva, J. G.; Alves, M. R. A.

2015-01-01

In this paper we report the synthesis and characterization of four new nitroaromatic compounds, 2-{6-nitrobenzo[1,3]dioxol-5-(methyleneamino)}benzoic acid (1), 2-{[5-(2-nitrophenyl)furan-2-yl]methylene-amino}benzoic acid (2), 2-{(6-nitrobenzo[1,3]dioxol-5-yl)methylene}hydrazinecarboxamide (3) and 2-{[5-(2-nitrophenyl)furan-2-yl]methylene}hydrazinecarboxamide (4). Compounds (1)-(4) have been authenticated by infrared and NMR spectroscopy, and the structure of (1), (2) and (4) have been determined by X-ray diffraction. In addition, the in vitro ability of compounds (1)-(4) to inhibit the growth of Leishmania infantum has been evaluated. Comparisons of the redox potential of the compounds and leishmanicidal activity indicate that the presence of the electroactive nitro group is important for the biological activity. The inhibition activity of compound (3) is comparable to that of the reference drug, SbCl3. Considering the important side effects and the low efficiency of SbCl3 in the case of resistance, compound (3) deserves further attention as a promising anti-leishmanicidal drug for veterinary use.

A multifunctional chemical sensor based on a three-dimensional lanthanide metal-organic framework

NASA Astrophysics Data System (ADS)

Du, Pei-Yao; Liao, Sheng-Yun; Gu, Wen; Liu, Xin

2016-12-01

A 3D lanthanide MOF with formula [Sm2(abtc)1.5(H2O)3(DMA)]·H2O·DMA (1) has been successfully synthesized via solvothermal method. Luminescence studies reveal that 1 exhibits dual functional detection benzyl alcohol and benzaldehyde among different aromatic molecules. In addition, 1 displays a turn-on luminescence sensing with respect to ethanol among different alcohol molecules, which suggests that 1 is also a promising luminescent probe for high selective sensing of ethanol.

[Study on the chemical constituets in ethyl acetante extraction from semen litchi].

PubMed

Huang, Kai-Wen; Guo, Jie-Wen; Chen, Jian-Mei; Lin, Li-Jing; Xu, Feng

2012-01-01

To study the chemical constituents in ethyl acetate extraction of Semen Litchi. The compounds were isolated and purified by column chromatography on silica gel and Sephadex LH-20 coupled with preparative silica gel TLC, their structures were identified by physicochemical properties and spectrum analysis. Five compounds were isolated and identified as stigmasterol (1), P-hydroxy-benzaldehyde (2), protocatechuic acid (3), daucosterol (4) and kaempferol-3-O-beta-D-glucopyranoside (5). Compounds 2 and 5 are obtained from this plant for the first time.

Synthesize and Characterization of Hydroxypropyl-N-octanealkyl Chitosan Ramification

NASA Astrophysics Data System (ADS)

Tan, Fu-neng

2018-03-01

A new type of amphiphilic ramification, hydroxypropyl-N-octanealkyl chitosan was prepared from chitosan via hydrophilic group and hydrophobic group were introduced. We could protect the amino group of chitosan via the reaction of chitosan and benzaldehyde could get Schiff base structure. Structures of the products were characterized with FT-IR, elemental analysis, themogrammetry (TG) analysis and X-ray diffraction. The degree of substitution of hydrophobic group was studied by elemental analysis. The result showed this chitosan ramification was soluble, biocompatible, biodegradable and nontoxic.

Analysis of volatile components from Melipona beecheii geopropolis from Southeast Mexico by headspace solid-phase microextraction.

PubMed

Torres-González, Ahira; López-Rivera, Paulina; Duarte-Lisci, Georgina; López-Ramírez, Ángel; Correa-Benítez, Adriana; Rivero-Cruz, J Fausto

2016-01-01

A head space solid-phase microextraction method combined with gas chromatography-mass spectrometry was developed and optimised to extract and analyse volatile compounds of Melipona beecheii geopropolis. Seventy-three constituents were identified using this technique in the sample of geopropolis collected. The main compounds detected include β-fenchene (14.53-15.45%), styrene (8.72-9.98%), benzaldehyde (7.44-7.82%) and the most relevant volatile components presents at high level in the geopropolis were terpenoids (58.17%).

High Contrast Organic Crystal Optical Modulator for Phased Array Antenna and Optical Signal Processing

DTIC Science & Technology

1994-10-27

Thus, we investigated several other secondary amines for use in the condensation of the picoline salt with various substituted benza!dehydes. C I I...a 10 gallon glass lined reactor was charged with 12 L of methanol, 3.120 kg of picoline , and 6.046 kg of methyl toluene sulfonate. The I reaction...dimethylamino benzaldehyde was added to the newly formed picoline salt, I together with an additional 6 L of methanol. Finally, 500 mL of pyrrolidine were slowly

SEPARATION OF PLUTONIUM FROM ELEMENTS HAVING AN ATOMIC NUMBER NOT LESS THAN 92

DOEpatents

Fitch, F.T.; Russell, D.S.

1958-09-16

other elements having atomic numbers nnt less than 92, It has been proposed in the past to so separate plutonium by solvent extraction iato an organic solvent using triglycoldichlcride as the organic solvent. The improvement lies in the discovery that triglycoldichloride performs far more efflciently as an extractant, wher certain second organie compounds are added to it. Mentioned as satisfactory additive compounds are benzaldehyde, saturated aliphatic aldehydes containtng at least twc carbon atoms, and certain polyhydric phenols.

Purification and biological evaluation of the metabolites produced by Streptomyces sp. TK-VL_333.

PubMed

Kavitha, Alapati; Prabhakar, Peddikotla; Vijayalakshmi, Muvva; Venkateswarlu, Yenamandra

2010-06-01

An Actinobacterium strain isolated from laterite soils of the Guntur region was identified as Streptomyces sp. TK-VL_333 by 16S rRNA analysis. Cultural, morphological and physiological characteristics of the strain were recorded. The secondary metabolites produced by the strain cultured on galactose-tyrosine broth were extracted and concentrated followed by defatting of the crude extract with cyclohexane to afford polar and non-polar residues. Purification of the two residues by column chromatography led to isolation of five polar and one non-polar fraction. Bioactivity- guided fractions were rechromatographed on a silica gel column to obtain four compounds, namely 1H-indole-3-carboxylic acid, 2,3-dihydroxy-5-(hydroxymethyl) benzaldehyde, 4-(4-hydroxyphenoxy) butan-2-one and acetic acid-2-hydroxy-6-(3-oxo-butyl)-phenyl ester from three active polar fractions and 8-methyl decanoic acid from one non-polar fraction. The structure of the compounds was elucidated on the basis of FT-IR, mass and NMR spectroscopy. The antimicrobial activity of the bioactive compounds produced by the strain was tested against the bacteria and fungi and expressed in terms of minimum inhibitory concentration. Antifungal activity of indole-3-carboxylic acid was further evaluated under in vitro and in vivo conditions. This is the first report of 2,3-dihydroxy-5-(hydroxymethyl) benzaldehyde, 4-(4-hydroxyphenoxy) butan-2-one, acetic acid-2-hydroxy-6-(3-oxo-butyl)-phenyl ester and 8-methyl decanoic acid from the genus Streptomyces. 2010 Elsevier Masson SAS. All rights reserved.

Repeated Inactivation of the First Committed Enzyme Underlies the Loss of Benzaldehyde Emission after the Selfing Transition in Capsella.

PubMed

Sas, Claudia; Müller, Frank; Kappel, Christian; Kent, Tyler V; Wright, Stephen I; Hilker, Monika; Lenhard, Michael

2016-12-19

The enormous species richness of flowering plants is at least partly due to floral diversification driven by interactions between plants and their animal pollinators [1, 2]. Specific pollinator attraction relies on visual and olfactory floral cues [3-5]; floral scent can not only attract pollinators but also attract or repel herbivorous insects [6-8]. However, despite its central role for plant-animal interactions, the genetic control of floral scent production and its evolutionary modification remain incompletely understood [9-13]. Benzenoids are an important class of floral scent compounds that are generated from phenylalanine via several enzymatic pathways [14-17]. Here we address the genetic basis of the loss of floral scent associated with the transition from outbreeding to selfing in the genus Capsella. While the outbreeding C. grandiflora emits benzaldehyde as a major constituent of its floral scent, this has been lost in the selfing C. rubella. We identify the Capsella CNL1 gene encoding cinnamate:CoA ligase as responsible for this variation. Population genetic analysis indicates that CNL1 has been inactivated twice independently in C. rubella via different novel mutations to its coding sequence. Together with a recent study in Petunia [18], this identifies cinnamate:CoA ligase as an evolutionary hotspot for mutations causing the loss of benzenoid scent compounds in association with a shift in the reproductive strategy of Capsella from pollination by insects to self-fertilization. Copyright © 2016 Elsevier Ltd. All rights reserved.

Ligand-tailored single-site silica supported titanium catalysts: Synthesis, characterization and towards cyanosilylation reaction

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xu, Wei; Li, Yani; Yu, Bo

2015-01-15

A successive anchoring of Ti(NMe{sub 2}){sub 4}, cyclopentadiene and a O-donor ligand, 1-hydroxyethylbenzene (PEA), 1,1′-bi-2-naphthol (Binol) or 2,3-dihydroxybutanedioic acid diethyl ester (Tartrate), on silica was conducted by SOMC strategy in moderate conditions. The silica, monitored by in-situ Fourier transform infrared spectroscopy (in-situ FT-IR), was pretreated at different temperatures (200, 500 and 800 °C). The ligand tailored silica-supported titanium complexes were characterized by in-situ FT-IR, {sup 13}C CP MAS-NMR, X-ray photoelectron spectroscopy (XPS), X-ray absorption near edge structure (XANES) and elemental analysis in detail, verifying that the surface titanium species are single sited. The catalytic activity of the ligand tailored single-sitemore » silica supported titanium complexes was evaluated by a cyanosilylation of benzaldehyde. The results showed that the catalytic activity is dependent strongly on the dehydroxylation temperatures of silica and the configuration of the ligands. - Graphical abstract: The ligand-tailored silica supported “single site” titanium complexes were synthesized by SOMC strategy and fully characterized. Their catalytic activity were evaluated by benzaldehyde silylcyanation. - Highlights: • Single-site silica supported Ti active species was prepared by SOMC technique. • O-donor ligand tailored Ti surface species was synthesized. • The surface species was characterized by XPS, {sup 13}C CP-MAS NMR, XANES etc. • Catalytic activity of the Ti active species in silylcyanation reaction was evaluated.« less

Synthesis and Characterization of New Palladium(II) Thiosemicarbazone Complexes and Their Cytotoxic Activity against Various Human Tumor Cell Lines

PubMed Central

Hernández, Wilfredo; Paz, Juan; Carrasco, Fernando; Spodine, Evgenia; Manzur, Jorge; Sieler, Joachim; Blaurock, Steffen; Beyer, Lothar

2013-01-01

The palladium(II) bis-chelate complexes of the type [Pd(TSC1-5)2] (6–10), with their corresponding ligands 4-phenyl-1-(acetone)-thiosemicarbazone, HTSC1 (1), 4-phenyl-1-(2′-chloro-benzaldehyde)-thiosemicarbazone, HTSC2 (2), 4-phenyl-1-(3′-hydroxy-benzaldehyde)-thiosemicarbazone, HTSC3 (3), 4-phenyl-1-(2′-naphthaldehyde)-thiosemicarbazone, HTSC4 (4), and 4-phenyl-1-(1′-nitro-2′-naphthaldehyde)-thiosemicarbazone, HTSC5 (5), were synthesized and characterized by elemental analysis and spectroscopic techniques (IR and 1H- and 13C-NMR). The molecular structure of HTSC3, HTSC4, and [Pd(TSC1)2] (6) have been determined by single crystal X-ray crystallography. Complex 6 shows a square planar geometry with two deprotonated ligands coordinated to PdII through the azomethine nitrogen and thione sulfur atoms in a cis arrangement. The in vitro cytotoxic activity measurements indicate that the palladium(II) complexes (IC50 = 0.01–9.87 μM) exhibited higher antiproliferative activity than their free ligands (IC50 = 23.48–70.86 and >250 μM) against different types of human tumor cell lines. Among all the studied palladium(II) complexes, the [Pd(TSC3)2] (8) complex exhibited high antitumor activity on the DU145 prostate carcinoma and K562 chronic myelogenous leukemia cells, with low values of the inhibitory concentration (0.01 and 0.02 μM, resp.). PMID:24391528

Engineering a Promiscuous Tautomerase into a More Efficient Aldolase for Self-Condensations of Linear Aliphatic Aldehydes.

PubMed

Rahimi, Mehran; van der Meer, Jan-Ytzen; Geertsema, Edzard M; Poelarends, Gerrit J

2017-07-18

The enzyme 4-oxalocrotonate tautomerase (4-OT) from Pseudomonas putida mt-2 takes part in a catabolic pathway for aromatic hydrocarbons, where it catalyzes the conversion of 2hydroxyhexa-2,4-dienedioate into 2-oxohexa-3-enedioate. This tautomerase can also promiscuously catalyze carbon-carbon bond-forming reactions, including various types of aldol reactions, by using its amino-terminal proline as a key catalytic residue. Here, we used systematic mutagenesis to identify two hotspots in 4-OT (Met45 and Phe50) at which single mutations give marked improvements in aldolase activity for the self-condensation of propanal. Activity screening of a focused library in which these two hotspots were varied led to the discovery of a 4-OT variant (M45Y/F50V) with strongly enhanced aldolase activity in the self-condensation of linear aliphatic aldehydes, such as acetaldehyde, propanal, and butanal, to yield α,β-unsaturated aldehydes. With both propanal and benzaldehyde, this double mutant, unlike the previously constructed single mutant F50A, mainly catalyzes the self-condensation of propanal rather than the cross-condensation of propanal and benzaldehyde, thus indicating that it indeed has altered substrate specificity. This variant could serve as a template to create new biocatalysts that lack dehydration activity and possess further enhanced aldolase activity, thus enabling the efficient enzymatic self-coupling of aliphatic aldehydes. © 2017 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.

Catalyst system and process for benzyl ether fragmentation and coal liquefaction

DOEpatents

Zoeller, Joseph Robert

1998-04-28

Dibenzyl ether can be readily cleaved to form primarily benzaldehyde and toluene as products, along with minor amounts of bibenzyl and benzyl benzoate, in the presence of a catalyst system comprising a Group 6 metal, preferably molybdenum, a salt, and an organic halide. Although useful synthetically for the cleavage of benzyl ethers, this cleavage also represents a key model reaction for the liquefaction of coal; thus this catalyst system and process should be useful in coal liquefaction with the advantage of operating at significantly lower temperatures and pressures.

The synthesis of α-aryl-α-aminophosphonates and α-aryl-α-aminophosphine oxides by the microwave-assisted Pudovik reaction

PubMed Central

Tajti, Ádám; Ádám, Anna; Csontos, István; Karaghiosoff, Konstantin; Czugler, Mátyás; Ábrányi-Balogh, Péter

2017-01-01

A family of α-aryl-α-aminophosphonates and α-aryl-α-aminophosphine oxides was synthesized by the microwave-assisted solvent-free addition of dialkyl phosphites and diphenylphosphine oxide, respectively, to imines formed from benzaldehyde derivatives and primary amines. After optimization, the reactivity was mapped, and the fine mechanism was evaluated by DFT calculations. Two α-aminophosphonates were subjected to an X-ray study revealing a racemic dimer formation made through a N–H···O=P intermolecular hydrogen bridges pair. PMID:28179951

(E)-2-[2-(Penta­fluoro­phen­yl)ethen­yl]-8-quinolyl acetate

PubMed Central

Zhang, Li-Yan; Huo, Yan-Ping

2009-01-01

The title compound, C19H10F5NO2, was synthesized by the 1:1 condensation of 2-methyl-8-hydroxy­quinaldine with penta­fluoro­benzaldehyde. It crystallizes with two almost identical mol­ecules in the asymmetric unit. The penta­fluoro­benzene ring is essentially coplanar with the quinoline ring, forming dihedral angles of 2.49 (17) and 8.72 (16)° in the two mol­ecules. PMID:21578456

Reductive Bis-addition of Aromatic Aldehydes to α,β-Unsaturated Esters via the Use of Sm/Cu(I) in Air: A Route to the Construction of Furofuran Lignans.

PubMed

Liu, Yongjun; Tian, Guang; Li, Jingjing; Qi, Yan; Wen, Yonghong; Du, Feng

2017-06-02

The novel bis-addition of benzaldehydes to acrylates or maleates was achieved by the direct use of samarium metal with the assistance of CuI under mild conditions under dry air, and the useful 2-hydroxylalkyl-γ-butyrolactons and lignan derivatives were thus constructed with high efficiency. The key factors that influence the reaction efficiency were investigated. The use of potassium iodide and molecular sieves as additives can improve the reaction efficiency remarkably.

Rate Acceleration of the Retro Diels-Alder Reaction of Anthracene Cycloadducts by Polysiloxy Substituents

DTIC Science & Technology

1988-01-01

Lindsey 13 yielded 9, 1O-dimethyl-2,3,6,7-tetramethoxyanthracene (13) by condensing veratrole (12) and acetaldehyde in the presence of sulfuric acid...combination of those cited by Boldt12 and Lindsey.13 To an ice cooled solution of veratrole (32 mL, 250 mmol) in acetic acid (125 mL) was slowly added...solution of veratrole (32 mL, 250 mmol) in acetic acid (125 mL) was slowly added an ice cooled solution of benzaldehyde ( 25 mL, 246 mmol) in methanol

Synthesis, spectral characterization and structural studies of a novel O, N, O donor semicarbazone and its binuclear copper complex with hydrogen bond stabilized lattice

NASA Astrophysics Data System (ADS)

Layana, S. R.; Saritha, S. R.; Anitha, L.; Sithambaresan, M.; Sudarsanakumar, M. R.; Suma, S.

2018-04-01

A novel O,N,O donor salicylaldehyde-N4-phenylsemicarbazone, (H2L) has been synthesized and physicochemically characterized. Detailed structural studies of H2L using single crystal X-ray diffraction technique reveals the existence of intra and inter molecular hydrogen bonding interactions, which provide extra stability to the molecule. We have successfully synthesized a binuclear copper(II) complex, [Cu2(HL)2(NO3)(H2O)2]NO3 with phenoxy bridging between the two copper centers. The complex was characterized by elemental analysis, magnetic susceptibility and conductivity measurements, FT-IR, UV-Visible, mass and EPR spectral methods. The grown crystals of the copper complex were employed for the single crystal X-ray diffraction studies. The complex possesses geometrically different metal centers, in which the ligand coordinates through ketoamide oxygen, azomethine nitrogen and deprotonated phenoxy oxygen. The extensive intermolecular hydrogen bonding interactions of the coordinated and the lattice nitrate groups interconnect the complex units to form a 2D supramolecular assembly. The ESI mass spectrum substantiates the existence of 1:1 complex. The g values obtained from the EPR spectrum in frozen DMF suggest dx2 -y2 ground state for the unpaired electron.

Selective inhibitor of endosomal trafficking pathways exploited by multiple toxins and viruses

PubMed Central

Gillespie, Eugene J.; Ho, Chi-Lee C.; Balaji, Kavitha; Clemens, Daniel L.; Deng, Gang; Wang, Yao E.; Elsaesser, Heidi J.; Tamilselvam, Batcha; Gargi, Amandeep; Dixon, Shandee D.; France, Bryan; Chamberlain, Brian T.; Blanke, Steven R.; Cheng, Genhong; de la Torre, Juan Carlos; Brooks, David G.; Jung, Michael E.; Colicelli, John; Damoiseaux, Robert; Bradley, Kenneth A.

2013-01-01

Pathogenic microorganisms and toxins have evolved a variety of mechanisms to gain access to the host-cell cytosol and thereby exert virulent effects upon the host. One common mechanism of cellular entry requires trafficking to an acidified endosome, which promotes translocation across the host membrane. To identify small-molecule inhibitors that block this process, a library of 30,000 small molecules was screened for inhibitors of anthrax lethal toxin. Here we report that 4-bromobenzaldehyde N-(2,6-dimethylphenyl)semicarbazone, the most active compound identified in the screen, inhibits intoxication by lethal toxin and blocks the entry of multiple other acid-dependent bacterial toxins and viruses into mammalian cells. This compound, which we named EGA, also delays lysosomal targeting and degradation of the EGF receptor, indicating that it targets host-membrane trafficking. In contrast, EGA does not block endosomal recycling of transferrin, retrograde trafficking of ricin, phagolysosomal trafficking, or phagosome permeabilization by Franciscella tularensis. Furthermore, EGA does not neutralize acidic organelles, demonstrating that its mechanism of action is distinct from pH-raising agents such as ammonium chloride and bafilomycin A1. EGA is a powerful tool for the study of membrane trafficking and represents a class of host-targeted compounds for therapeutic development to treat infectious disease. PMID:24191014

Synthesis and characterization of bis nitrato[4-hydroxyacetophenonesemicarbazone) nickel(II) complex as ionophore for thiocyanate-selective electrode.

PubMed

Chandra, Sulekh; Hooda, Sunita; Tomar, Praveen Kumar; Malik, Amrita; Kumar, Ankit; Malik, Sakshi; Gautam, Seema

2016-05-01

The PVC based-ion selective electrode viz., bis nitrato[4-hydroxyacetophenone semicarbazone] nickel(II) as an ionophore was prepared for the determination of thiocyanate ion. The ionophore was characterized by FT-IR, UV-vis, XRD, magnetic moment and elemental analysis (CHN). On the basis of spectral studies an octahedral geometry has been assigned. The best performance was obtained with a membrane composition of 31% PVC, 63% 2-nitrophenyl octylether, 4.0% ionophore and 2.0% trioctylmethyl ammonium chloride. The electrode exhibited an excellent Nernstian response to SCN(-) ion ranging from 1.0 × 10(-7) to 1.0 × 10(-1)M with a detection limit of 8.6 × 10(-8)M and a slope of -59.4 ± 0.2 mV/decade over a wide pH range (1.8-10.7) with a fast response time (6s) at 25 °C. The proposed electrode showed high selectivity for thiocyanate ion over a number of common inorganic and organic anions. It was successfully applied to direct determination of thiocyanate in biological (urine and saliva) samples in order to distinguish between smokers and non-smokers, environmental samples and as an indicator electrode for titration of thiocyanate ions with AgNO3 solution. Copyright © 2016 Elsevier B.V. All rights reserved.

The volatile profiles of a rare apple (Malus domestica Borkh.) honey: shikimic acid-pathway derivatives, terpenes, and others.

PubMed

Kuś, Piotr Marek; Jerković, Igor; Tuberoso, Carlo Ignazio Giovanni; Šarolić, Mladenka

2013-09-01

The volatile profiles of rare Malus domestica Borkh. honey were investigated for the first time. Two representative samples from Poland (sample I) and Spain (sample II) were selected by pollen analysis (44-45% of Malus spp. pollen) and investigated by GC/FID/MS after headspace solid-phase microextraction (HS-SPME) and ultrasonic solvent extraction (USE). The apple honey is characterized by high percentage of shikimic acid-pathway derivatives, as well as terpenes, norisoprenoids, and some other compounds such as coumaran and methyl 1H-indole-3-acetate. The main compounds of the honey headspace were (sample I; sample II): benzaldehyde (9.4%; 32.1%), benzyl alcohol (0.3%; 14.4%), hotrienol (26.0%, 6.2%), and lilac aldehyde isomers (26.3%; 1.7%), but only Spanish sample contained car-2-en-4-one (10.2%). CH2 Cl2 and pentane/Et2 O 1 : 2 (v/v) were used for USE. The most relevant compounds identified in the extracts were: benzaldehyde (0.9-3.9%), benzoic acid (2.0-11.2%), terpendiol I (0.3-7.4%), coumaran (0.0-2.8%), 2-phenylacetic acid (2.0-26.4%), methyl syringate (3.9-13.1%), vomifoliol (5.0-31.8%), and methyl 1H-indole-3-acetate (1.9-10.2%). Apple honey contained also benzyl alcohol, 2-phenylethanol, (E)-cinnamaldehyde, (E)-cinnamyl alcohol, eugenol, vanillin, and linalool that have been found previously in apple flowers, thus disclosing similarity of both volatile profiles. Copyright © 2013 Verlag Helvetica Chimica Acta AG, Zürich.

Regulator and enzyme specificities of the TOL plasmid-encoded upper pathway for degradation of aromatic hydrocarbons and expansion of the substrate range of the pathway.

PubMed Central

Abril, M A; Michan, C; Timmis, K N; Ramos, J L

1989-01-01

The TOL plasmid upper pathway operon encodes enzymes involved in the catabolism of aromatic hydrocarbons such as toluene and xylenes. The regulator of the gene pathway, the XylR protein, exhibits a very broad effector specificity, being able to recognize as effectors not only pathway substrates but also a wide variety of mono- and disubstituted methyl-, ethyl-, and chlorotoluenes, benzyl alcohols, and p-chlorobenzaldehyde. Benzyl alcohol dehydrogenase and benzaldehyde dehydrogenase, two upper pathway enzymes, exhibit very broad substrate specificities and transform unsubstituted substrates and m- and p-methyl-, m- and p-ethyl-, and m- and p-chloro-substituted benzyl alcohols and benzaldehydes, respectively, at a high rate. In contrast, toluene oxidase only oxidizes toluene, m- and p-xylene, m-ethyltoluene, and 1,2,4-trimethylbenzene [corrected], also at a high rate. A biological test showed that toluene oxidase attacks m- and p-chlorotoluene, albeit at a low rate. No evidence for the transformation of p-ethyltoluene by toluene oxidase has been found. Hence, toluene oxidase acts as the bottleneck step for the catabolism of p-ethyl- and m- and p-chlorotoluene through the TOL upper pathway. A mutant toluene oxidase able to transform p-ethyltoluene was isolated, and a mutant strain capable of fully degrading p-ethyltoluene was constructed with a modified TOL plasmid meta-cleavage pathway able to mineralize p-ethylbenzoate. By transfer of a TOL plasmid into Pseudomonas sp. strain B13, a clone able to slowly degrade m-chlorotoluene was also obtained. PMID:2687253

Low-Temperature Molecular Layer Deposition Using Monofunctional Aromatic Precursors and Ozone-Based Ring-Opening Reactions.

PubMed

Svärd, Laura; Putkonen, Matti; Kenttä, Eija; Sajavaara, Timo; Krahl, Fabian; Karppinen, Maarit; Van de Kerckhove, Kevin; Detavernier, Christophe; Simell, Pekka

2017-09-26

Molecular layer deposition (MLD) is an increasingly used deposition technique for producing thin coatings consisting of purely organic or hybrid inorganic-organic materials. When organic materials are prepared, low deposition temperatures are often required to avoid decomposition, thus causing problems with low vapor pressure precursors. Monofunctional compounds have higher vapor pressures than traditional bi- or trifunctional MLD precursors, but do not offer the required functional groups for continuing the MLD growth in subsequent deposition cycles. In this study, we have used high vapor pressure monofunctional aromatic precursors in combination with ozone-triggered ring-opening reactions to achieve sustained sequential growth. MLD depositions were carried out by using three different aromatic precursors in an ABC sequence, namely with TMA + phenol + O 3 , TMA + 3-(trifluoromethyl)phenol + O 3 , and TMA + 2-fluoro-4-(trifluoromethyl)benzaldehyde + O 3 . Furthermore, the effect of hydrogen peroxide as a fourth step was evaluated for all studied processes resulting in a four-precursor ABCD sequence. According to the characterization results by ellipsometry, infrared spectroscopy, and X-ray reflectivity, self-limiting MLD processes could be obtained between 75 and 150 °C with each of the three aromatic precursors. In all cases, the GPC (growth per cycle) decreased with increasing temperature. In situ infrared spectroscopy indicated that ring-opening reactions occurred in each ABC sequence. Compositional analysis using time-of-flight elastic recoil detection indicated that fluorine could be incorporated into the film when 3-(trifluoromethyl)phenol and 2-fluoro-4-(trifluoromethyl)benzaldehyde were used as precursors.

Proteins involved in wine aroma compounds metabolism by a Saccharomyces cerevisiae flor-velum yeast strain grown in two conditions.

PubMed

Moreno-García, Jaime; García-Martínez, Teresa; Millán, M Carmen; Mauricio, Juan Carlos; Moreno, Juan

2015-10-01

A proteomic and exometabolomic study was conducted on Saccharomyces cerevisiae flor yeast strain growing under biofilm formation condition (BFC) with ethanol and glycerol as carbon sources and results were compared with those obtained under no biofilm formation condition (NBFC) containing glucose as carbon source. By using modern techniques, OFFGEL fractionator and LTQ-Orbitrap for proteome and SBSE-TD-GC-MS for metabolite analysis, we quantified 84 proteins including 33 directly involved in the metabolism of glycerol, ethanol and 17 aroma compounds. Contents in acetaldehyde, acetic acid, decanoic acid, 1,1-diethoxyethane, benzaldehyde and 2-phenethyl acetate, changed above their odor thresholds under BFC, and those of decanoic acid, ethyl octanoate, ethyl decanoate and isoamyl acetate under NBFC. Of the twenty proteins involved in the metabolism of ethanol, acetaldehyde, acetoin, 2,3-butanediol, 1,1-diethoxyethane, benzaldehyde, organic acids and ethyl esters, only Adh2p, Ald4p, Cys4p, Fas3p, Met2p and Plb1p were detected under BFC and as many Acs2p, Ald3p, Cem1p, Ilv2p, Ilv6p and Pox1p, only under NBFC. Of the eight proteins involved in glycerol metabolism, Gut2p was detected only under BFC while Pgs1p and Rhr2p were under NBFC. Finally, of the five proteins involved in the metabolism of higher alcohols, Thi3p was present under BFC, and Aro8p and Bat2p were under NBFC. Copyright © 2015 Elsevier Ltd. All rights reserved.

Application of pulsed field gradient NMR techniques for investigating binding of flavor compounds to macromolecules.

PubMed

Jung, Da-Mi; De Ropp, Jeffrey S; Ebeler, Susan E

2002-07-17

Two diffusion-based NMR techniques are presented and used to investigate the binding of selected flavor compounds to macromolecules. A pulsed field gradient NMR (PFG-NMR) method was applied to measure the apparent diffusion coefficients of four alkanone compounds as they associated with bovine serum albumin (BSA). The change in the apparent diffusion coefficient as a function of the BSA/alkanone ratio was fitted to yield binding constants (K(a)()) and binding stoichiometry (n) for each alkanone. The results showed that the apparent diffusion coefficients of alkanones increased with a decrease in the BSA/alkanone ratios, and the measured values of K(a)() and n were comparable with those obtained with other methods and depended on the alkanone structure. A diffusion-based nuclear Overhauser effect (called diffusion NOE pumping) method was also applied to screen mixtures of flavor compounds and identify those that have a binding affinity to complex macromolecules. Using this technique benzaldehyde and vanillin were observed to bind with bovine serum albumin, whereas 2-phenylethanol was identified as a nonbinding or weakly binding ligand with BSA. The diffusion NOE pumping method was also applied to a hydro alcoholic solution of cacao bean tannin extracts to which a mixture of ethylbenzoate, benzaldehyde, and 2-phenylethanol was added. The diffusion NOE pumping technique clearly indicated that ethylbenzoate had a stronger binding affinity to the polymeric (-)-epicatechin units of the cacao bean tannin extracts than the other two flavor compounds. The results successfully demonstrate the potential applications of diffusion-based NMR techniques for studying flavors and nonvolatile food matrix interactions.

Structural variation from heterometallic cluster-based 1D chain to heterometallic tetranuclear cluster: Syntheses, structures and magnetic properties

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Shu-Hua, E-mail: zsh720108@163.com; Zhao, Ru-Xia; Li, He-Ping

Using the solvothermal method, we present the comparative preparation of ([Co{sub 3}Na(dmaep){sub 3}(ehbd)(N{sub 3}){sub 3}]·DMF){sub n} (1) and [Co{sub 2}Na{sub 2}(hmbd){sub 4}(N{sub 3}){sub 2}(DMF){sub 2}] (2), where Hehbd is 3-ethoxy-2-hydroxy-benzaldehyde, Hhmbd is 3-methoxy-2-hydroxy-benzaldehyde, and Hdmaep is 2-dimethylaminomethyl-6-ethoxy-phenol, which was synthesized by an in-situ reaction. Complexes 1 and 2 were characterized by elemental analysis, IR spectroscopy, and X-ray single-crystal diffraction. Complex 1 is a novel heterometallic cluster-based 1-D chain and 2 is a heterometallic tetranuclear cluster. The (Co{sub 3}{sup II}Na) and (Co{sub 2}{sup II}Na{sub 2}) cores display dominant ferromagnetic interaction from the nature of the binding modes through μ{sub 1,1,1}-N{sub 3}{supmore » –} (end-on, EO). - Graphical abstract: Two novel cobalt complexes have been prepared. Compound 1 consists of tetranuclear (Co{sub 3}{sup II}Na) units, which further formed a 1-D chain. Compound 2 is heterometallic tetranuclear cluster. Two complexes display dominant ferromagnetic interaction. - Highlights: • Two new heterometallic complexes have been synthesized by solvothermal method. • The stereospecific blockade of the ligands in the synthesis system seems to be the most important synthetic parameter. • The magnetism studies show that 1 and 2 exhibit ferromagnetic interactions. • Complex 1 shows slowing down of magnetization and not blocking of magnetization.« less

Mechanism of intermolecular hydroacylation of vinylsilanes catalyzed by a rhodium(I) olefin complex: a DFT study.

PubMed

Meng, Qingxi; Shen, Wei; Li, Ming

2012-03-01

Density functional theory (DFT) was used to investigate the Rh(I)-catalyzed intermolecular hydroacylation of vinylsilane with benzaldehyde. All intermediates and transition states were optimized completely at the B3LYP/6-31G(d,p) level (LANL2DZ(f) for Rh). Calculations indicated that Rh(I)-catalyzed intermolecular hydroacylation is exergonic, and the total free energy released is -110 kJ mol(-1). Rh(I)-catalyzed intermolecular hydroacylation mainly involves the active catalyst CA2, rhodium-alkene-benzaldehyde complex M1, rhodium-alkene-hydrogen-acyl complex M2, rhodium-alkyl-acyl complex M3, rhodium-alkyl-carbonyl-phenyl complex M4, rhodium-acyl-phenyl complex M5, and rhodium-ketone complex M6. The reaction pathway CA2 + R2 → M1b → T1b → M2b → T2b1 → M3b1 → T4b → M4b → T5b → M5b → T6b → M6b → P2 is the most favorable among all reaction channels of Rh(I)-catalyzed intermolecular hydroacylation. The reductive elimination reaction is the rate-determining step for this pathway, and the dominant product predicted theoretically is the linear ketone, which is consistent with Brookhart's experiments. Solvation has a significant effect, and it greatly decreases the free energies of all species. The use of the ligand Cp' (Cp' = C(5)Me(4)CF(3)) decreased the free energies in general, and in this case the rate-determining step was again the reductive elimination reaction.

Aromatic aldehydes at the active site of aldehyde oxidoreductase from Desulfovibrio gigas: reactivity and molecular details of the enzyme-substrate and enzyme-product interaction.

PubMed

Correia, Hugo D; Marangon, Jacopo; Brondino, Carlos D; Moura, Jose J G; Romão, Maria J; González, Pablo J; Santos-Silva, Teresa

2015-03-01

Desulfovibrio gigas aldehyde oxidoreductase (DgAOR) is a mononuclear molybdenum-containing enzyme from the xanthine oxidase (XO) family, a group of enzymes capable of catalyzing the oxidative hydroxylation of aldehydes and heterocyclic compounds. The kinetic studies reported in this work showed that DgAOR catalyzes the oxidative hydroxylation of aromatic aldehydes, but not heterocyclic compounds. NMR spectroscopy studies using (13)C-labeled benzaldehyde confirmed that DgAOR catalyzes the conversion of aldehydes to the respective carboxylic acids. Steady-state kinetics in solution showed that high concentrations of the aromatic aldehydes produce substrate inhibition and in the case of 3-phenyl propionaldehyde a suicide substrate behavior. Hydroxyl-substituted aromatic aldehydes present none of these behaviors but the kinetic parameters are largely affected by the position of the OH group. High-resolution crystallographic structures obtained from single crystals of active-DgAOR soaked with benzaldehyde showed that the side chains of Phe425 and Tyr535 are important for the stabilization of the substrate in the active site. On the other hand, the X-ray data of DgAOR soaked with trans-cinnamaldehyde showed a cinnamic acid molecule in the substrate channel. The X-ray data of DgAOR soaked with 3-phenyl propionaldehyde showed clearly how high substrate concentrations inactivate the enzyme by binding covalently at the surface of the enzyme and blocking the substrate channel. The different reactivity of DgAOR versus aldehyde oxidase and XO towards aromatic aldehydes and N-heterocyclic compounds is explained on the basis of the present kinetic and structural data.

Development of an LC-MS/MS analytical method for the simultaneous measurement of aldehydes from polyunsaturated fatty acids degradation in animal feed.

PubMed

Douny, Caroline; Bayram, Pinar; Brose, François; Degand, Guy; Scippo, Marie-Louise

2016-05-01

Knowing that polyunsaturated fatty acids can lead to the formation of potentially toxic aldehydes as secondary oxidation products, an analytical method using liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) detection was developed to measure the concentration of eight aldehydes in animal feed: malondialdehyde (MDA), 4-hydroxy-2-nonenal (4-HNE), 4-hydroxy-2-hexenal (4-HHE), crotonaldehyde (CRT), benzaldehyde (BNZ), hexanal (HXL), 2,4-nonadienal, and 2,4-decadienal. The developed method was validated according to the criteria and procedure described in international standards. The evaluated parameters were specificity/selectivity, recovery, precision, accuracy, uncertainty, limits of detection and quantification, using the concept of accuracy profiles. These parameters were determined during experiments conducted over three different days with ground Kellogg's® Corn Flakes® cereals as model matrix for animal feed and spiked at different levels of concentration. Malondialdehyde, 4-HHE, 4-HNE, crotonaldehyde, benzaldehyde, and hexanal can be analyzed in the same run in animal feed with a very good accuracy, with recovery rates ranging from 86 to 109% for a working range going from 0.16 to 12.50 mg/kg. The analysis of 2,4-nonadienal and 2,4-decadienal can also be performed but in a limited range of concentration and with a limited degree of accuracy. Their recovery rates ranged between 54 and 114% and coefficient of variation for the intermediate precision between 11 and 25% for these two compounds. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Synthesis and characterization of Cu(II), Co(II) and Ni(II) complexes of a number of sulfadrug azodyes and their application for wastewater treatment

NASA Astrophysics Data System (ADS)

El-Baradie, K.; El-Sharkawy, R.; El-Ghamry, H.; Sakai, K.

2014-03-01

The azodye ligand (HL1) was synthesized from the coupling of sulfaguanidine diazonium salt with 2,4-dihydroxy-benzaldehyde while the two ligands, HL2 and HL3, were prepared by the coupling of sulfadiazine diazonium salt with salicylaldehyde (HL2) and 2,4-dihydroxy-benzaldehyde (HL3). The prepared ligands were characterized by elemental analysis, IR, 1H NMR and mass spectra. Cu(II), Co(II) and Ni(II) complexes of the prepared ligands have been synthesized and characterized by various spectroscopic techniques like IR, UV-Visible as well as magnetic and thermal (TG and DTA) measurements. It was found that all the ligands behave as a monobasic bidentate which coordinated to the metal center through the azo nitrogen and α-hydroxy oxygen atoms in the case of HL1 and HL3. HL2 coordinated to the metal center through sulfonamide oxygen and pyrimidine nitrogen. The applications of the prepared complexes in the oxidative degradation of indigo carmine dye exhibited good catalytic activity in the presence of H2O2 as an oxidant. The reactions followed first-order kinetics and the rate constants were determined. The degradation reaction involved the catalytic action of the azo-dye complexes toward H2O2 decomposition, which can lead to the generation of HOrad radicals as a highly efficient oxidant attacking the target dye. The detailed kinetic studies and the mechanism of these catalytic reactions are under consideration in our group.

Synthesis and anticandidal activity of some imidazopyridine derivatives.

PubMed

Kaplancikli, Zafer Asim; Turan-Zitouni, Gülhan; Ozdemir, Ahmet; Revial, Gilbert

2008-12-01

New hydrazide derivatives of imidazo[1,2-a]pyridine have been synthesized and evaluated for anticandidal activity. The reaction of imidazo[1,2-a]pyridine-2-carboxylic acid hydrazides with various benzaldehydes gave N-(benzylidene)imidazo[ 1,2-a]pyridine-2-carboxylic acid hydrazide derivatives. Their anticandidal activities against Candida albicans and Candida glabrata (isolates obtained from Osmangazi University, Faculty of Medicine, Eskisehir, Turkey), Candida albicans (ATCC 90028), Candida utilis (NRLL Y-900), Candida tropicalis (NRLL Y-12968), Candida krusei (NRLL Y-7179), Candida zeylanoides (NRLL Y-1774), and Candida parapsilosis (NRLL Y-12696) were investigated.

The enzymic hydrolysis of amygdalin

PubMed Central

Haisman, D. R.; Knight, D. J.

1967-01-01

Chromatographic examination has shown that the enzymic hydrolysis of amygdalin by an almond β-glucosidase preparation proceeds consecutively: amygdalin was hydrolysed to prunasin and glucose; prunasin to mandelonitrile and glucose; mandelonitrile to benzaldehyde and hydrocyanic acid. Gentiobiose was not formed during the enzymic hydrolysis. The kinetics of the production of mandelonitrile and hydrocyanic acid from amygdalin by the action of the β-glucosidase preparation favour the probability that three different enzymes are involved, each specific for one hydrolytic stage, namely, amygdalin lyase, prunasin lyase and hydroxynitrile lyase. Cellulose acetate electrophoresis of the enzyme preparation showed that it contained a number of enzymically active components. PMID:4291788

Interaction of aromatic alcohols, aldehydes and acids with α-hydroxyl-containing carbon-centered radicals: A steady state radiolysis study

NASA Astrophysics Data System (ADS)

Samovich, S. N.; Brinkevich, S. D.; Shadyro, O. I.

2013-01-01

Benzaldehyde and its derivatives efficaciously oxidize in aqueous solutions α-hydroxyl-containing carbon-centered radicals (α-HCR) of various structures, suppressing thereby the radical recombination and fragmentation reactions. The compounds containing cinnamic moieties are capable of adding α-hydroxyethyl radicals (α-HER) to the carbon-carbon double bonds conjugated with the aromatic system to form molecular products identifiable by mass spectrometry. On radiolysis of aqueous ethanol solutions, reduction of α-HER by aromatic alcohols and acids has been shown to proceed via formation of their adducts with hydrated electron species.

Phytochemical, morphological, and biological investigations of propolis from Central Chile.

PubMed

Valcic, S; Montenegro, G; Mujica, A M; Avila, G; Franzblau, S; Singh, M P; Maiese, W M; Timmermann, B N

1999-01-01

Propolis from central Chile was investigated for its plant origin by microscopical analysis of pollen grains and leaf fragments found in the sample. The pollen grains that appear with significant higher frequency in the sample corresponded to four native and two introduced species, whereas leaf fragments corresponded to four native species. Seventeen phenolic compounds that belong to the phenylpropane, benzaldehyde, dihydrobenzofuran, or benzopyran classes, were isolated from an organic extract that was found to have a moderate growth inhibitory activity against Mycobacterium avium, M. tuberculosis, and two strains of Staphylococcus aureus. The components responsible for activity were determined.

Organic materials with nonlinear optical properties

DOEpatents

Stupp, Samuel I.; Son, Sehwan; Lin, Hong-Cheu

1995-01-01

The present invention is directed to organic materials that have the ability to double or triple the frequency of light that is directed through the materials. Particularly, the present invention is directed to the compound 4-[4-(2R)-2-cyano-7-(4'-pentyloxy-4-biphenylcarbonyloxy)phenylheptylidene) phenylcarbonyloxy]benzaldehyde, which can double the frequency of light that is directed through the compound. The invention is also directed to the compound (12-hydroxy-5,7-dodecadiynyl) 4'-[(4'-pentyloxy-4-biphenyl)carbonyloxy]-4-biphenylcarboxylate, and its polymeric form. The polymeric form can triple the frequency of light directed through it.

Fe/Al synergy in Fe(2)O(3) nanoparticles supported on porous aluminosilicate materials: excelling activities in oxidation reactions.

PubMed

Mariana Balu, Alina; Pineda, Antonio; Yoshida, Kenta; Manuel Campelo, Juan; Gai, Pratibha L; Luque, Rafael; Angel Romero, Antonio

2010-11-07

A synergetic Fe-Al effect in Fe(2)O(3) nanoparticles supported on mesoporous aluminosilicates compared to pure siliceous silicates has been demonstrated, for the first time, by a remarkably superior catalytic activity of the former in the microwave-assisted selective oxidation of benzyl alcohol to benzaldehyde. This significant finding, that also deeply influences the acidity of the materials (increasing total and particularly Lewis acidity), can have important consequences in the improved efficiency of these systems in related oxidations as well as in acid catalysed processes.

Fluorescence method for enzyme analysis which couples aromatic amines with aromatic aldehydes

DOEpatents

Smith, R.E.; Dolbeare, F.A.

1980-10-21

Analysis of proteinases is accomplished using conventional amino acid containing aromatic amine substrates. Aromatic amines such as 4-methoxy-2-naphthylamine (4M2NA), 2-naphthylamine, aminoisophthalic acid dimethyl ester, p-nitroaniline, 4-methoxy-1-aminofluorene and coumarin derivatives resulting from enzymatic hydrolysis of the substrate couples with aromatic aldehydes such as 5-nitrosalicylaldehyde (5-NSA), benzaldehyde and p-nitrobenzaldehyde to produce Schiff-base complexes which are water insoluble. Certain Schiff-base complexes produce a shift from blue to orange-red (visible) fluorescence. Such complexes are useful in the assay of enzymes. No Drawings

Fluorescence method for enzyme analysis which couples aromatic amines with aromatic aldehydes

DOEpatents

Smith, Robert E. [557 Escondido Cir., Livermore, CA 94550; Dolbeare, Frank A. [5178 Diane La., Livermore, CA 94550

1980-10-21

Analysis of proteinases is accomplished using conventional amino acid containing aromatic amine substrates. Aromatic amines such as 4-methoxy-2-naphthylamine (4M2NA), 2-naphthylamine, aminoisophthalic acid dimethyl ester, p-nitroaniline, 4-methoxy-1-aminofluorene and coumarin derivatives resulting from enzymatic hydrolysis of the substrate couples with aromatic aldehydes such as 5-nitrosalicylaldehyde (5-NSA), benzaldehyde and p-nitrobenzaldehyde to produce Schiff-base complexes which are water insoluble. Certain Schiff-base complexes produce a shift from blue to orange-red (visible) fluorescence. Such complexes are useful in the assay of enzymes.

Organic materials with nonlinear optical properties

DOEpatents

Stupp, S.I.; Son, S.; Lin, H.C.

1995-05-02

The present invention is directed to organic materials that have the ability to double or triple the frequency of light that is directed through the materials. Particularly, the present invention is directed to the compound 4-[4-(2R)-2-cyano-7-(4{prime}-pentyloxy-4-biphenylcarbonyloxy)phenylheptylidenephenylcarbonyloxy]benzaldehyde, which can double the frequency of light that is directed through the compound. The invention is also directed to the compound (12-hydroxy-5,7-dodecadiynyl)-4{prime}-[(4{prime}-pentyloxy-4-biphenyl)carbonyloxy]-4-biphenylcarboxylate, and its polymeric form. The polymeric form can triple the frequency of light directed through it. 4 figs.

Fluorescence method for enzyme analysis which couples aromatic amines with aromatic aldehydes

DOEpatents

Smith, Robert E.; Dolbeare, Frank A.

1979-01-01

Analysis of proteinases is accomplished using conventional amino acid containing aromatic amine substrates. Aromatic amines such as 4-methoxy-2-naphthylamine (4M2NA), 2-naphthylamine, aminoisophthalic acid dimethyl ester, p-nitroaniline, 5-methoxy-1-aminofluorene and coumarin derivatives resulting from enzymatic hydrolysis of the substrate couples with aromatic aldehydes such as 5-nitrosalicylaldehyde (5-NSA), benzaldehyde and p-nitrobenzaldehyde to produce Schiff-base complexes which are water insoluble. Certain Schiff-base complexes produce a shift from blue to orange-red (visible) fluorescence. Such complexes are useful in the assay of enzymes.

Alkyne Benzannulation Reactions for the Synthesis of Novel Aromatic Architectures.

PubMed

Hein, Samuel J; Lehnherr, Dan; Arslan, Hasan; J Uribe-Romo, Fernando; Dichtel, William R

2017-11-21

Aromatic compounds and polymers are integrated into organic field effect transistors, light-emitting diodes, photovoltaic devices, and redox-flow batteries. These compounds and materials feature increasingly complex designs, and substituents influence energy levels, bandgaps, solution conformation, and crystal packing, all of which impact performance. However, many polycyclic aromatic hydrocarbons of interest are difficult to prepare because their substitution patterns lie outside the scope of current synthetic methods, as strategies for functionalizing benzene are often unselective when applied to naphthalene or larger systems. For example, cross-coupling and nucleophilic aromatic substitution reactions rely on prefunctionalized arenes, and even directed metalation methods most often modify positions near Lewis basic sites. Similarly, electrophilic aromatic substitutions access single regioisomers under substrate control. Cycloadditions provide a convergent route to densely functionalized aromatic compounds that compliment the above methods. After surveying cycloaddition reactions that might be used to modify the conjugated backbone of poly(phenylene ethynylene)s, we discovered that the Asao-Yamamoto benzannulation reaction is notably efficient. Although this reaction had been reported a decade earlier, its scope and usefulness for synthesizing complex aromatic systems had been under-recognized. This benzannulation reaction combines substituted 2-(phenylethynyl)benzaldehydes and substituted alkynes to form 2,3-substituted naphthalenes. The reaction tolerates a variety of sterically congested alkynes, making it well-suited for accessing poly- and oligo(ortho-arylene)s and contorted hexabenzocoronenes. In many cases in which asymmetric benzaldehyde and alkyne cycloaddition partners are used, the reaction is regiospecific based on the electronic character of the alkyne substrate. Recognizing these desirable features, we broadened the substrate scope to include silyl- and halogen-substituted alkynes. Through a combined experimental and computational approach, we have elucidated mechanistic insight and key principles that govern the regioselectivity outcome of the benzannulation of structurally diverse alkynes. We have applied these methods to prepare sterically hindered, shape-persistent aromatic systems, heterocyclic aromatic compounds, functionalized 2-aryne precursors, polyheterohalogenated naphthalenes, ortho-arylene foldamers, and graphene nanoribbons. As a result of these new synthetic avenues, aromatic structures with interesting properties were uncovered such as ambipolar charge transport in field effect transistors based on our graphene nanoribbons, conformational aspects of ortho-arylene architectures resulting from intramolecular π-stacking, and modulation of frontier molecular orbitals via protonation of heteroatom containing aromatic systems. Given the availability of many substituted 2-(phenylethynyl)benzaldehydes and the regioselectivity of the benzannulation reaction, naphthalenes can be prepared with control of the substitution pattern at seven of the eight substitutable positions. Researchers in a range of fields are likely to benefit directly from newly accessible molecular and polymeric systems derived from polyfunctionalized naphthalenes.

Iron(II) catalysis in oxidation of hydrocarbons with ozone in acetonitrile

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bataineh, Hajem; Pestovsky, Oleg; Bakac, Andreja

Oxidation of alcohols, ethers, and sulfoxides by ozone in acetonitrile is catalyzed by submillimolar concentrations of Fe(CH 3CN) 6 2+. The catalyst provides both rate acceleration and greater selectivity toward the less oxidized products. For example, Fe(CH 3CN) 6 2+-catalyzed oxidation of benzyl alcohol yields benzaldehyde almost exclusively (>95%), whereas the uncatalyzed reaction generates a 1:1 mixture of benzaldehyde and benzoic acid. Similarly, aliphatic alcohols are oxidized to aldehydes/ketones, cyclobutanol to cyclobutanone, and diethyl ether to a 1:1 mixture of ethanol and acetaldehyde. The kinetics of oxidation of alcohols and diethyl ether are first-order in [Fe(CH 3CN) 6 2+] andmore » [O 3] and independent of [substrate] at concentrations greater than ~5 mM. In this regime, the rate constant for all of the alcohols is approximately the same, k cat = (8 ± 1) × 10 4 M –1 s –1, and that for (C 2H 5) 2O is (5 ± 0.5) × 10 4 M –1 s –1. In the absence of substrate, Fe(CH 3CN) 6 2+ reacts with O 3 with k Fe = (9.3 ± 0.3) × 10 4 M –1 s –1. The similarity between the rate constants k Fe and k cat strongly argues for Fe(CH 3CN) 6 2+/O 3 reaction as rate-determining in catalytic oxidation. The active oxidant produced in Fe(CH 3CN) 6 2+/O 3 reaction is suggested to be an Fe(IV) species in analogy with a related intermediate in aqueous solutions. As a result, this assignment is supported by the similarity in kinetic isotope effects and relative reactivities of the two species toward substrates.« less

Development and application of a validated stability-indicating HPLC method for simultaneous determination of granisetron hydrochloride, benzyl alcohol and their main degradation products in parenteral dosage forms.

PubMed

Hewala, Ismail; El-Fatatre, Hamed; Emam, Ehab; Mubrouk, Mokhtar

2010-06-30

A simple, rapid and sensitive reversed phase high performance liquid chromatographic method using photodiode array detection was developed and validated for the simultaneous determination of granisetron hydrochloride, benzyl alcohol, 1-methyl-1H-indazole-3-carboxylic acid (the main degradation product of granisetron) and benzaldehyde (the main degradation product of benzyl alcohol) in granisetron injections. The separation was achieved on Hypersil BDS C8 (250 mm x 4.6 mm i.d., 5 microm particle diameter) column using a mobile phase consisted of acetonitrile:0.05 M KH(2)PO(4):triethylamine (22:100:0.15) adjusted to pH 4.8. The column was maintained at 25 degrees C and 20 microL of solutions was injected. Photodiode array detector was used to test the peak purity and the chromatograms were extracted at 210 nm. Naphazoline hydrochloride was used as internal standard. The method was validated with respect to specificity, linearity, accuracy, precision, limit of quantitation and limit of detection. The validation acceptance criteria were met in all cases. Identification of the pure peaks was carried out using library match programmer and wavelengths of derivative optima of the spectrograms of the peaks. The method was successfully applied to the determination of the investigated drugs and their degradation products in different batches of granisetron injections. The method was proved to be sensitive for the determination down to 0.03 and 0.01% of granisetron degradation product and benzaldehyde, respectively, which are far below the compendia limits for testing these degradation products in their corresponding intact drugs. Copyright 2010 Elsevier B.V. All rights reserved.

Isolation and characterization of Lactobacillus helveticus DSM 20075 variants with improved autolytic capacity.

PubMed

Spus, Maciej; Liu, Hua; Wels, Michiel; Abee, Tjakko; Smid, Eddy J

2017-01-16

Lactobacillus helveticus is widely used in dairy fermentations and produces a range of enzymes, which upon cell lysis can be released into the cheese matrix and impact degradation of proteins, peptides and lipids. In our study we set out to explore the potential of Lb. helveticus DSM 20075 for increased autolytic capacity triggered by conditions such as low pH and high salt concentrations encountered in cheese environments. Lb. helveticus DSM 20075 was subjected to varied incubation temperatures (ranging from 37 to 50°C). High-temperature incubation (in the range of 45 to 50°C) allowed us to obtain a collection of six variant strains (V45-V50), which in comparison to the wild-type strain, showed higher growth rates at elevated temperatures (42°C-45°C). Moreover, variant strain V50 showed a 4-fold higher, in comparison to wild type, autolytic capacity in cheese-like conditions. Next, strain V50 was used as an adjunct in lab-scale cheese making trials to measure its impact on aroma formation during ripening. Specifically, in cheeses made with strain V50, the relative abundance of benzaldehyde increased 3-fold compared to cheeses made with the wild-type strain. Analysis of the genome sequence of strain V50 revealed multiple mutations in comparison to the wild-type strain DSM 20075 including a mutation found in a gene coding for a metal ion transporter, which can potentially be linked to intracellular accumulation of Mn 2+ and benzaldehyde formation. The approach of high-temperature incubation can be applied in dairy industry for the selection of (adjunct) cultures targeted at accelerated cheese ripening and aroma formation. Copyright © 2016 Elsevier B.V. All rights reserved.

Di­aqua­[5,10,15,20-tetra­kis­(4-chloro­phen­yl)porphyrinato-κ4 N]iron(III) tri­fluoro­methane­sulfonate–4-hy­droxy-3-meth­oxy­benzaldehyde–water (1/1/2)

PubMed Central

Ben Haj Hassen, Leila; Ezzayani, Khaireddine; Rousselin, Yoann; Nasri, Habib

2014-01-01

In the title compound, [Fe(C44H24Cl4N4)(H2O)2](SO3CF3)·C8H8O3·2H2O, the FeIII cation is chelated by the four N atoms of the deprotonated tetra­kis­(4-chloro­tetra­phen­yl)porphyrin (TClPP) and further coordinated by two water mol­ecules in a distorted octa­hedral geometry. In the crystal, the cations, anions, 4-hy­droxy-3-meth­oxy­benzaldehyde and water mol­ecules of crystallization are linked by classical O—H⋯O hydrogen bonds and weak C—H⋯O and C—H⋯Cl hydrogen bonds into a three-dimensional supra­molecular architecture. The crystal packing is further stabilized by weak C—H⋯π inter­actions involving pyrrole and benzene rings. π–π stacking between parallel benzene rings of adjacent 4-hy­droxy-3-meth­oxy­benzaldehyde mol­ecules is also observed, the centroid–centroid distance being 3.8003 (13) Å. The three F atoms of the anion are disordered over two sets of sites, with a refined occupancy ratio 0.527 (12):0.473 (12). The O atom of one water mol­ecule of crystallization is also disordered over two positions in an occupancy ratio of 0.68 (5):0.32 (5). PMID:25249880

Investigation of molecular metabolites in expired air of healthy man in condition of long-term isolation in hermetical confined environment

NASA Astrophysics Data System (ADS)

Tsarkov, Dmitriy; Mardanov, Robert; Markin, Andrey; Moukhamedieva, Lana

Investigation of intermediary metabolites, produced in cells, in expired air of healthy man is directed on determination of molecular markers which are reflecting normal physiological pro-cesses in an organism, as well as on determination and validation of biomarkers for objective screening and non-invasive prenosological diagnostics of disorders in metabolic processes caused by negative effect of live environment. Investigation of influence of long-term isolation in her-metical confined environment on composition of healthy human expired air was made during experiment with 105 days isolation in condition of controlled environment and standard food ra-tion. Expired air samples were analyzed on gas chromatograph associated with the quadrupole mass spectrometer. The investigation results show that at rest hydroxy ketones, mostly 1-hydroxy-prorapanone-2 (acetol), aldehydes (decenal, benzaldehyde), acetophenone, phenol and fatty acids were determined. After physical performance (oxidative stress) the content of ke-tones (heptanone-2, heptanone-3), phenol, determined aldehydes (decenal, octadecenal) and acetol in expired air of volunteers decreased. It can be concerned with prevailing of alternative -methylglyoxalic metabolic pathway and caused by oxidative stress. Analysis of expired air samples taken on 30, 60 and 90 day of isolation showed that in conditions of long-term iso-lation concentration of heptanone-2, heptanone-3, 2,3-butadione, acetol, furanones, aldehydes (decenal, benzaldehyde) and acetophenone is increasing while concentration of phenol and fatty acids is decreasing as compared to samples taken before isolation. It was shown that dynamics of concentration of saturated hydrocarbons in expired air can be informative marker for estima-tion of organism response to oxidative stress, while the level of acetol can be used as indicator of man's training status, validity of exercise load and as a marker of hypoxic state.

Composition and emission dynamics of migratory locust volatiles in response to changes in developmental stages and population density.

PubMed

Wei, Jianing; Shao, Wenbo; Wang, Xianhui; Ge, Jin; Chen, Xiangyong; Yu, Dan; Kang, Le

2017-02-01

Chemical communication plays an important role in density-dependent phase change in locusts. However, the volatile components and emission patterns of the migratory locust, Locusta migratoria, are largely unknown. In this study, we identified the chemical compositions and emission dynamics of locust volatiles from the body and feces and associated them with developmental stages, sexes and phase changes. The migratory locust shares a number of volatile components with the desert locust (Schistocerca gregaria), but the emission dynamics of the two locust species are significantly different. The body odors of the gregarious nymphs in the migratory locust consisted of phenylacetonitrile (PAN), benzaldehyde, guaiacol, phenol, aliphatic acids and 2,3-butanediol, and PAN was the dominant volatile. Volatiles from the fecal pellets of the nymphs primarily consist of guaiacol and phenol. Principal component analysis (PCA) showed significant differences in the volatile profiles between gregarious and solitary locusts. PAN and 4-vinylanisole concentrations were significantly higher in gregarious individuals than in solitary locusts. Gregarious mature males released significantly higher amounts of PAN and 4-vinylanisole during adulthood than mature females and immature adults of both sexes. Furthermore, PAN and 4-vinylanisole were completely lost in gregarious nymphs during the solitarization process, but were obtained by solitary nymphs during gregarization. The amounts of benzaldehyde, guaiacol and phenol only unidirectionally decreased from solitary to crowded treatment. Aliphatic aldehydes (C7 to C10), which were previously reported as locust volatiles, are now identified as environmental contaminants. Therefore, our results illustrate the precise odor profiles of migratory locusts during developmental stages, sexes and phase change. However, the function and role of PAN and other aromatic compounds during phase transition need further investigation. © 2016 Institute of Zoology, Chinese Academy of Sciences.

Preparation of Different Substitued Polypyridine Ligands, Ruthenium(II)-Bridged Complexes and Spectoscopıc Studies.

PubMed

Obali, Aslihan Yilmaz; Ucan, Halil Ismet

2016-09-01

Novel different substitued polypyridine ligands 4-((4-(1H-imidazo[4,5-f][1,10]phenanthroline-2-yl)phenoxy)methyl)benzaldehyde (BA-PPY), (E)-N-(4-((4-(1H-imidazo[4,5-f][1,10]phenanthroline-2-yl)phenoxy)methyl)benzylidene)-pyrene-4-amine (PR-PPY), (E)-N-(4-((4-(1H-imidazo[4,5-f][1,10] phenanthroline-2-yl)phenoxy)methyl)benzylidene)-1,10-phenanthroline-5amine (FN-PPY), 2-(4-(bromomethyl)phenyl)-1H-imidazo[4,5-f][1,10] phenanthroline (BR-PPY), 2-(4-(azidomethyl)phenyl)-1H-imidazo[4,5-f][1,10]phenanthroline (N3-PPY) and triazole containing polypyridine ligand 3,4-bis[(4-(metoxy)-1,2,3-triazole)1-methylphenyl)-1H-imidazo[4,5-f][1,10]phenanthroline)] benzaldehyde (BA-DIPPY) and Ruthenium(II) complexes were synthesized and characterized. Their photopysical properties were investigated. The complexes RuP(PR-PPY), RuB(PR-PPY, RuP(FN-PPY) and RuB(FN-PPY) exhibited a broad absorption bands at 485, 475, 476, and 453 nm, respectively, assignable to the spin-allowed MLCT (dπ-π*) transition. The emission maxima of the pyrene-appended polypyridine ligand PR-PPY was observed at λems = 616 nm and the phenanthroline-appended polypyridine ligand FN-PPY was observed at λems = 668 nm. And the emission maxima of the complexes RuP(PR-PPY), RuB(PR-PPY), RuP(FN-PPY) and RuB(FN-PPY) were observed at λems = 646, 646, 685 and 685 nm, respectively. As seen in fluorescence spectra, the fluorescence intensities of the ligands are higher than their metal complexes. This is because of quenching effect of Ruthenium(II) metal on chromophore groups.

In situ DRIFTS study of O3 adsorption on CaO, γ-Al2O3, CuO, α-Fe2O3 and ZnO at room temperature for the catalytic ozonation of cinnamaldehyde

NASA Astrophysics Data System (ADS)

Wu, Jianfeng; Su, Tongming; Jiang, Yuexiu; Xie, Xinling; Qin, Zuzeng; Ji, Hongbing

2017-08-01

In situ DRIFTS were conducted to identify adsorbed ozone and/or adsorbed oxygen species on CaO, ZnO, γ-Al2O3, CuO and α-Fe2O3 surfaces at room temperature. Samples were characterized by means of TG, XRD, N2 adsorption-desorption, pyridine-IR, nitrobenzene-IR, chloroform-IR, and CO2-TPD. Pyridine-DRIFTS measurements evidence two kinds of acid sites in all the samples. Nitrobenzene, chloroform-DRIFTS, and CO2-TPD reveal that there are large amounts of medium-strength base sites on all the metal oxides, and only CaO, ZnO, and γ-Al2O3 have strong base sites. And the benzaldehyde selectivity was increased in the same order of the alkalinity of the metal oxides. With weaker sites, ozone molecules form coordinative complexes bound via the terminal oxygen atom, observed by vibrational frequencies at 2095-2122 and 1026-1054 cm-1. The formation of ozonide O3- at 790 cm-1, atomic oxygen at 1317 cm-1, and superoxide O2- at 1124 cm-1 was detected; these species are believed to be intermediates of O3 decomposition on strong acid/base sites. The adsorption of ozone on metal oxides is a weak adsorption, and other gases, such as CO2, will compete with O3 adsorption. The mechanism of cinnamaldehyde ozonation at room temperature over CaO shows that cinnamaldehyde can not only be oxidized into cinnamic acid, but also be further oxidized into benzaldehyde, benzoic acid, maleic anhydride, and ultimately mineralized to CO2 in the presence of O3.

Iron(II) catalysis in oxidation of hydrocarbons with ozone in acetonitrile

DOE PAGES

Bataineh, Hajem; Pestovsky, Oleg; Bakac, Andreja

2015-02-11

Oxidation of alcohols, ethers, and sulfoxides by ozone in acetonitrile is catalyzed by submillimolar concentrations of Fe(CH 3CN) 6 2+. The catalyst provides both rate acceleration and greater selectivity toward the less oxidized products. For example, Fe(CH 3CN) 6 2+-catalyzed oxidation of benzyl alcohol yields benzaldehyde almost exclusively (>95%), whereas the uncatalyzed reaction generates a 1:1 mixture of benzaldehyde and benzoic acid. Similarly, aliphatic alcohols are oxidized to aldehydes/ketones, cyclobutanol to cyclobutanone, and diethyl ether to a 1:1 mixture of ethanol and acetaldehyde. The kinetics of oxidation of alcohols and diethyl ether are first-order in [Fe(CH 3CN) 6 2+] andmore » [O 3] and independent of [substrate] at concentrations greater than ~5 mM. In this regime, the rate constant for all of the alcohols is approximately the same, k cat = (8 ± 1) × 10 4 M –1 s –1, and that for (C 2H 5) 2O is (5 ± 0.5) × 10 4 M –1 s –1. In the absence of substrate, Fe(CH 3CN) 6 2+ reacts with O 3 with k Fe = (9.3 ± 0.3) × 10 4 M –1 s –1. The similarity between the rate constants k Fe and k cat strongly argues for Fe(CH 3CN) 6 2+/O 3 reaction as rate-determining in catalytic oxidation. The active oxidant produced in Fe(CH 3CN) 6 2+/O 3 reaction is suggested to be an Fe(IV) species in analogy with a related intermediate in aqueous solutions. As a result, this assignment is supported by the similarity in kinetic isotope effects and relative reactivities of the two species toward substrates.« less

Synthesis of Renewable meta-Xylylenediamine from Biomass-Derived Furfural.

PubMed

Scodeller, Ivan; Mansouri, Samir; Morvan, Didier; Muller, Eric; de Oliveira Vigier, Karine; Wischert, Raphael; Jérôme, François

2018-04-30

We report the synthesis of biomass-derived functionalized aromatic chemicals from furfural, a building block nowadays available in large scale from low-cost biomass. The scientific strategy relies on a Diels-Alder/aromatization sequence. By controlling the rate of each step, it was possible to produce exclusively the meta aromatic isomer. In particular, through this route, we describe the synthesis of renewably sourced meta-xylylenediamine (MXD). Transposition of this work to other furfural-derived chemicals is also discussed and reveals that functionalized biomass-derived aromatics (benzaldehyde, benzylamine, etc.) can be potentially produced, according to this route. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

The oxidation of 2,6-di-tert-butyl-4-methylphenol

USGS Publications Warehouse

Yohe, G.R.; Dunbar, J.E.; Pedrotti, R.L.; Scheidt, F.M.; Lee, F.G.H.; Smith, E.C.

1956-01-01

The products formed in the oxidation of 2,6-di-tert-butyl-4-methylphenol with oxygen and sodium hydroxide at about 100?? are 3,5-di-tert-butyl-4-hydroxybenzaldehyde, trimethylacetic acid, an acidic compound C14H22O3, and probably 2,6-di-tert-butylbenzoquinone (which was actually isolated in the similar oxidation of the above-named benzaldehyde), in addition to compounds previously reported. Some of the properties of C14H22O3 are given, and the oxidation of it to 2,3-di-tert-butylsuccinic anhydride is described, but assignment of structure is reserved pending the completion of more experimental work.

Spectral regression and correlation coefficients of some benzaldimines and salicylaldimines in different solvents

NASA Astrophysics Data System (ADS)

Hammud, Hassan H.; Ghannoum, Amer; Masoud, Mamdouh S.

2006-02-01

Sixteen Schiff bases obtained from the condensation of benzaldehyde or salicylaldehyde with various amines (aniline, 4-carboxyaniline, phenylhydrazine, 2,4-dinitrophenylhydrazine, ethylenediamine, hydrazine, o-phenylenediamine and 2,6-pyridinediamine) are studied with UV-vis spectroscopy to observe the effect of solvents, substituents and other structural factors on the spectra. The bands involving different electronic transitions are interpreted. Computerized analysis and multiple regression techniques were applied to calculate the regression and correlation coefficients based on the equation that relates peak position λmax to the solvent parameters that depend on the H-bonding ability, refractive index and dielectric constant of solvents.

Amido-Schiff base derivatives as colorimetric fluoride sensor: Effect of nitro substitution on the sensitivity and color change.

PubMed

Ghosh, Soumen; Alam, Md Akhtarul; Ganguly, Aniruddha; Guchhait, Nikhil

2015-01-01

A series of Schiff bases synthesized by the condensation of benzohydrazide and -NO2 substituted benzaldehyde have been used as selective fluoride ion sensor. Test paper coated with these synthetic Schiff bases (test kits) can detect fluoride ion selectively with a drastic color change and detection can be achieved by just using the naked-eye without the help of any optical instrument. Interestingly, the position of -NO2 group in the amido Schiff bases has an effect on the sensitivity as well as on the change of color of species. Copyright © 2015 Elsevier B.V. All rights reserved.

Surface and catalytic properties of acid metal carbons prepared by the sol gel method

NASA Astrophysics Data System (ADS)

Aguado-Serrano, J.; Rojas-Cervantes, M. L.; Martín-Aranda, R. M.; López-Peinado, A. J.; Gómez-Serrano, V.

2006-06-01

The sol-gel method has been applied for the synthesis of a series of acid metal-carbon xerogels (with M = V, Cr, Mo and Ni) by polymerisation of resorcinol with formaldehyde in the presence of metallic precursors. A blank sample was also prepared without any metal addition. The xerogels were heated in nitrogen at 1000 °C to obtain the pyrolysed products. The samples were characterised by different techniques such as thermal-mass spectrometry analysis, gas physisorption, and mercury porosimetry. In addition, the acid character of the pyrolysed products was tested by the Claisen-Schmidt condensation between benzaldehyde and acetophenone for the formation of chalcones.

Preparation, characterization and catalytic properties of MCM-48 supported tungstophosphoric acid mesoporous materials for green synthesis of benzoic acid

NASA Astrophysics Data System (ADS)

Wu, Hai-Yan; Zhang, Xiao-Li; Chen, Xi; Chen, Ya; Zheng, Xiu-Cheng

2014-03-01

MCM-48 and tungstophosphoric acid (HPW) were prepared and applied for the synthesis of HPW/MCM-48 mesoporous materials. The characterization results showed that HPW/MCM-48 obtained retained the typical mesopore structure of MCM-48, and the textural parameters decreased with the increase loading of HPW. The catalytic oxidation results of benzyl alcohol and benzaldehyde with 30% H2O2 indicated that HPW/MCM-48 was an efficient catalyst for the green synthesis of benzoic acid. Furthermore, 35 wt% HPW/MCM-48 sample showed the highest activity under the reaction conditions.

Direct evidence of photochemical α-cleavage of benzoin in fluid solutions

NASA Astrophysics Data System (ADS)

Koyanagi, Motohiko; Futami, Hiroshi; Mukai, Masahiro; Yamauchi, Seigo

1989-02-01

By means of optical absorption, 1 NMR, and transient EPR techniques, the fate of diluted benzoin upon light irradiation to its S 1 (nπ*) state has been investigated in methylcyclohexane and benzene solutions at room temperature. The CIDEP spectrum of benzoin is observed for the first time, and the intermediate radicals involved are assigned. The overall results show that the main scheme of the photochemical reactions is the α-cleavage occurring in the excited triplet state of benzoin, as proved in the almost net emission pattern of the CIDEP spectra. A stoichiometric reaction leading to effective benzaldehyde formation is established for the benzoin solutions.

New Element Organic Frameworks Based on Sn, Sb, and Bi, with Permanent Porosity and High Catalytic Activity

PubMed Central

Fritsch, Julia; Rose, Marcus; Wollmann, Philipp; Böhlmann, Winfried; Kaskel, Stefan

2010-01-01

We present new element organic frameworks based on Sn, Sb and Bi atoms connected via organic linkers by element-carbon bonds. The open frameworks are characterized by specific surface areas (BET) of up to 445 m2 g-1 and a good stability under ambient conditions resulting from a highly hydrophobic inner surface. They show good performance as heterogeneous catalysts in the cyanosylilation of benzaldehyde as a test reaction. Due to their catalytic activity, this class of materials might be able to replace common homogeneous element-organic and often highly toxic catalysts especially in the food industry.

Synthesis and Spectroscopic Properties of Carbazole-Oxadiazoles.

PubMed

Gündoğdu, Leyla; Şen, Nihan; Hızlıateş, Cevher Gündoğdu; Ergün, Mustafa Yavuz

2017-11-01

Four new carbazole-oxadiazole derivatives (3a-b, 6a-b) were prepared from the reaction of aromatic aldehydes and carbohydrazides which were synthesized from carbazole aldehydes namely 9-hexyl-9H-carbazole-3-carbaldehyde 1 and 4-(9H-carbazole-9-yl)benzaldehyde 4 and acid hydrazides. The structures of the new derivatives were confirmed by 1 H-NMR and FT-IR. The optical properties such as maximum absorption and emission wavelengths (λ; nm), molar extinction coefficients (ε; cm -1 M -1 ), Stoke's shifts (ΔλST; nm) and quantum yields (ϕF), of the carbazole-oxadiazole derivatives were declared in dichloromethane, toluene and tetrahydrofuran solutions.

[Study on chemical constituents from roots of Saussurea lappa].

PubMed

Zhang, Ting; Wang, Hongqing; Du, Guanhua; Chen, Ruoyun

2009-05-01

To study the chemical constituents in roots of Saussurea lappa. Isolation and purification were carried out by silica gel, Sephadex LH-20 and RP-18 column chromatography. The chemical structures of constituents were elucidated on the basis of spectral data. Eleven compounds were isolated and identified as: 5,7-dihydroxy-2-methylchromone (1), p-hydroxybenzaldehyde (2), 3,5-dimethoxy-4-hydroxy-benzaldehyde (3), 3,5-dimethoxy-4-hydroxy-acetophenone (4), ethyl 2-pyrrolidinone-5(s)-carboxylate (5), 5-hydroxymethyl-furaldehyde (6), palmitic acid (7), succinic acid (8), glucose (9), daucosterol (10), beta-sitosterol (11). Compounds 1, 2, 4, 5, 7, 9 were isolated from the genus Saussurea for the first time.

Solvent-free synthesis, spectral correlations and antimicrobial activities of some aryl E 2-propen-1-ones

NASA Astrophysics Data System (ADS)

Sathiyamoorthi, K.; Mala, V.; Sakthinathan, S. P.; Kamalakkannan, D.; Suresh, R.; Vanangamudi, G.; Thirunarayanan, G.

2013-08-01

Totally 38 aryl E 2-propen-1-ones including nine substituted styryl 4-iodophenyl ketones have been synthesised using solvent-free SiO2-H3PO4 catalyzed Aldol condensation between respective methyl ketones and substituted benzaldehydes under microwave irradiation. The yields of the ketones are more than 80%. The synthesised chalcones were characterized by their analytical, physical and spectroscopic data. The spectral frequencies of synthesised substituted styryl 4-iodophenyl ketones have been correlated with Hammett substituent constants, F and R parameters using single and multi-linear regression analysis. The antimicrobial activities of 4-iodophenyl chalcones have been studied using Bauer-Kirby method.

Antimicrobial Activity and Urease Inhibition of Schiff Bases Derived from Isoniazid and Fluorinated Benzaldehydes and of Their Copper(II) Complexes.

PubMed

Habala, Ladislav; Varényi, Samuel; Bilková, Andrea; Herich, Peter; Valentová, Jindra; Kožíšek, Jozef; Devínsky, Ferdinand

2016-12-17

In order to evaluate the influence of substitution on biological properties of Schiff bases and their metal complexes, a series of differently substituted fluorine-containing Schiff bases starting from the drug isoniazid (isonicotinylhydrazide) were prepared and their structures were established by single-crystal X-ray diffraction. Also, four copper(II) complexes of these Schiff bases were synthesized. The prepared compounds were evaluated for their antimicrobial activity and urease inhibition. Two of the Schiff bases exerted activity against C. albicans . All copper(II) complexes showed excellent inhibitory properties against jack bean urease, considerably better than that of the standard inhibitor acetohydroxamic acid.

Solvent for urethane adhesives and coatings and method of use

DOEpatents

Simandl, Ronald F.; Brown, John D.; Holt, Jerrid S.

2010-08-03

A solvent for urethane adhesives and coatings, the solvent having a carbaldehyde and a cyclic amide as constituents. In some embodiments the solvent consists only of miscible constituents. In some embodiments the carbaldehyde is benzaldehyde and in some embodiments the cyclic amide is N-methylpyrrolidone (M-pyrole). An extender may be added to the solvent. In some embodiments the extender is miscible with the other ingredients, and in some embodiments the extender is non-aqueous. For example, the extender may include isopropanol, ethanol, tetrahydro furfuryl alcohol, benzyl alcohol, Gamma-butyrolactone or a caprolactone. In some embodiments a carbaldehyde and a cyclic amide are heated and used to separate a urethane bonded to a component.

Direct Synthesis of Protoberberine Alkaloids by Rh-Catalyzed C-H Bond Activation as the Key Step.

PubMed

Jayakumar, Jayachandran; Cheng, Chien-Hong

2016-01-26

A one-pot reaction of substituted benzaldehydes with alkyne-amines by a Rh-catalyzed C-H activation and annulation to afford various natural and unnatural protoberberine alkaloids is reported. This reaction provides a convenient route for the generation of a compound library of protoberberine salts, which recently have attracted great attention because of their diverse biological activities. In addition, pyridinium salt derivatives can also be formed in good yields from α,β-unsaturated aldehydes and amino-alkynes. This reaction proceeds with excellent regioselectivity and good functional group compatibility under mild reaction conditions by using O2 as the oxidant. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

FeF(3) catalyzed cascade C-C and C-N bond formation: synthesis of differentially substituted triheterocyclic benzothiazole functionalities under solvent-free condition.

PubMed

Atar, Amol B; Jeong, Yeon Tae

2014-05-01

A series of diverse polyfunctionalized triheterocyclic benzothiazoles were easily prepared in excellent yields via the Biginelli reaction of 2-aminobenzothiazole with substituted benzaldehydes and α-methylene ketones using FeF(3) as an expeditious catalyst under solvent-free conditions. The protocol provides a practical and straightforward approach toward highly functionalized triheterocyclic benzothiazole derivatives in excellent yields. The reaction was conveniently promoted by FeF(3) and the catalyst could be recovered easily after the reaction and reused without any loss of its catalytic activity. The advantageous features of this methodology are high atom economy, operational simplicity, shorter reaction time, convergence, and facile automation.

Quantitative structure activity relationship studies of mushroom tyrosinase inhibitors

NASA Astrophysics Data System (ADS)

Xue, Chao-Bin; Luo, Wan-Chun; Ding, Qi; Liu, Shou-Zhu; Gao, Xing-Xiang

2008-05-01

Here, we report our results from quantitative structure-activity relationship studies on tyrosinase inhibitors. Interactions between benzoic acid derivatives and tyrosinase active sites were also studied using a molecular docking method. These studies indicated that one possible mechanism for the interaction between benzoic acid derivatives and the tyrosinase active site is the formation of a hydrogen-bond between the hydroxyl (aOH) and carbonyl oxygen atoms of Tyr98, which stabilized the position of Tyr98 and prevented Tyr98 from participating in the interaction between tyrosinase and ORF378. Tyrosinase, also known as phenoloxidase, is a key enzyme in animals, plants and insects that is responsible for catalyzing the hydroxylation of tyrosine into o-diphenols and the oxidation of o-diphenols into o-quinones. In the present study, the bioactivities of 48 derivatives of benzaldehyde, benzoic acid, and cinnamic acid compounds were used to construct three-dimensional quantitative structure-activity relationship (3D-QSAR) models using comparative molecular field (CoMFA) and comparative molecular similarity indices (CoMSIA) analyses. After superimposition using common substructure-based alignments, robust and predictive 3D-QSAR models were obtained from CoMFA ( q 2 = 0.855, r 2 = 0.978) and CoMSIA ( q 2 = 0.841, r 2 = 0.946), with 6 optimum components. Chemical descriptors, including electronic (Hammett σ), hydrophobic (π), and steric (MR) parameters, hydrogen bond acceptor (H-acc), and indicator variable ( I), were used to construct a 2D-QSAR model. The results of this QSAR indicated that π, MR, and H-acc account for 34.9, 31.6, and 26.7% of the calculated biological variance, respectively. The molecular interactions between ligand and target were studied using a flexible docking method (FlexX). The best scored candidates were docked flexibly, and the interaction between the benzoic acid derivatives and the tyrosinase active site was elucidated in detail. We believe that the QSAR models built here provide important information necessary for the design of novel tyrosinase inhibitors.

Mechanically Robust 3D Nanostructure Chitosan-Based Hydrogels with Autonomic Self-Healing Properties.

PubMed

Karimi, Ali Reza; Khodadadi, Azam

2016-10-12

Fabrication of hydrogels based on chitosan (CS) with superb self-healing behavior and high mechanical and electrical properties has become a challenging and fascinating topic. Most of the conventional hydrogels lack these properties at the same time. Our objectives in this research were to synthesize, characterize, and evaluate the general properties of chitosan covalently cross-linked with zinc phthalocyanine tetra-aldehyde (ZnPcTa) framework. Our hope was to access an unprecedented self-healable three-dimensional (3D) nanostructure that would harvest the superior mechanical and electrical properties associated with chitosan. The properties of cross-linker such as the structure, steric effect, and rigidity of the molecule played important roles in determining the microstructure and properties of the resulting hydrogels. The tetra-functionalized phthalocyanines favor a dynamic Schiff-base linkage with chitosan to form a 3D porous nanostructure. Based on this strategy, the self-healing ability, as demonstrated by rheological recovery and macroscopic and microscopic observations, is introduced through dynamic covalent Schiff-base linkage between NH 2 groups in CS and benzaldehyde groups at cross-linker ends. The hydrogel was characterized using FT-IR, NMR, UV/vis, and rheological measurements. In addition, cryogenic scanning electron microscopy (cryo-SEM) was employed as a technique to visualize the internal morphology of the hydrogels. Study of the surface morphology of the hydrogel showed a 3D porous nanostructure with uniform morphology. Furthermore, incorporating the conductive nanofillers, such as carbon nanotubes (CNTs), into the structure can modulate the mechanical and electrical properties of the obtained hydrogels. Interestingly, these hydrogel nanocomposites proved to have very good film-forming properties, high modulus and strength, acceptable electrical conductivity, and excellent self-healing properties at neutral pH. Such properties can be finely tuned through variation of the cross-linker and CNT concentration, and as a result these structures are promising candidates for potential applications in various fields of research.

Characterization of sphingosine-1-phosphate lyase activity by electrospray ionization-liquid chromatography/tandem mass spectrometry quantitation of (2E)-hexadecenal.

PubMed

Berdyshev, Evgeny V; Goya, Jonathan; Gorshkova, Irina; Prestwich, Glenn D; Byun, Hoe-Sup; Bittman, Robert; Natarajan, Viswanathan

2011-01-01

Sphingosine-1-phosphate (S1P) is a sphingolipid signaling molecule crucial for cell survival and proliferation. S1P-mediated signaling is largely controlled through its biosynthesis and degradation, and S1P lyase (S1PL) is the only known enzyme that irreversibly degrades sphingoid base-1-phosphates to phosphoethanolamine and the corresponding fatty aldehydes. S1PL-mediated degradation of S1P results in the formation of (2E)-hexadecenal, whereas hexadecanal is the product of dihydrosphingosine-1-phosphate (DHS1P) degradation. Fatty aldehydes can undergo biotransformation to fatty acids and/or alcohols, making them elusive and rendering the task of fatty aldehyde quantitation challenging. We have developed a simple, highly sensitive, and high-throughput protocol for (2E)-hexadecenal quantitation as a semicarbazone derivative by liquid chromatography-electrospray ionization-tandem mass spectrometry. The approach was applied to determining S1PL activity in vitro with the ability to use as low as 0.25μg of microsomal protein per assay. The method is also applicable to the use of total tissue homogenate as the source of S1PL. A correction for (2E)-hexadecenal disappearance due to its biotransformation during enzymatic reaction is required, especially at higher protein concentrations. The method was applied to confirm FTY720 as the inhibitor of S1PL with an IC₅₀ value of 52.4μM. Copyright © 2010 Elsevier Inc. All rights reserved.

Characterization of sphingosine-1-phosphate lyase activity by ESI-LC/MS/MS quantitation of (2E)-hexadecenal

PubMed Central

Berdyshev, Evgeny V.; Goya, Jonathan; Gorshkova, Irina; Prestwich, Glenn D.; Byun, Hoe-Sup; Bittman, Robert; Natarajan, Viswanathan

2010-01-01

Sphingosine-1-phosphate (S1P) is a sphingolipid signaling molecule crucial for cell survival and proliferation. S1P-mediated signaling is largely controlled through its biosynthesis and degradation, and S1P lyase (S1PL) is the only known enzyme, which irreversibly degrades sphingoid base-1-phosphates to phosphoethanolamine and the corresponding fatty aldehydes. S1PL-mediated degradation of S1P results in the formation of (2E)-hexadecenal, while hexadecanal is the product of dihydrosphingosine-1-phosphate (DHS1P) degradation. Fatty aldehydes can undergo biotransformation to fatty acids and/or alcohols, which makes them elusive and renders the task of fatty aldehyde quantitation challenging. We have developed a simple, highly sensitive, and high-throughput protocol for (2E)-hexadecenal quantitation as a semicarbazone derivative by liquid chromatography-electrospray ionization-tandem mass spectrometry. The approach was applied to determining S1PL activity in vitro, with the ability to use as low as 0.25 µg microsomal protein per assay. The method is also applicable to the use of total tissue homogenate as the source of S1PL. A correction for (2E)-hexadecenal disappearance due to its biotransformation during enzymatic reaction is required, especially at higher protein concentrations. The method was applied to confirm FTY720 as the inhibitor of S1PL with the IC50 of 52.4 µM. PMID:20804717

EGA Protects Mammalian Cells from Clostridium difficile CDT, Clostridium perfringens Iota Toxin and Clostridium botulinum C2 Toxin

PubMed Central

Schnell, Leonie; Mittler, Ann-Katrin; Sadi, Mirko; Popoff, Michel R.; Schwan, Carsten; Aktories, Klaus; Mattarei, Andrea; Tehran, Domenico Azarnia; Montecucco, Cesare; Barth, Holger

2016-01-01

The pathogenic bacteria Clostridium difficile, Clostridium perfringens and Clostridium botulinum produce the binary actin ADP-ribosylating toxins CDT, iota and C2, respectively. These toxins are composed of a transport component (B) and a separate enzyme component (A). When both components assemble on the surface of mammalian target cells, the B components mediate the entry of the A components via endosomes into the cytosol. Here, the A components ADP-ribosylate G-actin, resulting in depolymerization of F-actin, cell-rounding and eventually death. In the present study, we demonstrate that 4-bromobenzaldehyde N-(2,6-dimethylphenyl)semicarbazone (EGA), a compound that protects cells from multiple toxins and viruses, also protects different mammalian epithelial cells from all three binary actin ADP-ribosylating toxins. In contrast, EGA did not inhibit the intoxication of cells with Clostridium difficile toxins A and B, indicating a possible different entry route for this toxin. EGA does not affect either the binding of the C2 toxin to the cells surface or the enzyme activity of the A components of CDT, iota and C2, suggesting that this compound interferes with cellular uptake of the toxins. Moreover, for C2 toxin, we demonstrated that EGA inhibits the pH-dependent transport of the A component across cell membranes. EGA is not cytotoxic, and therefore, we propose it as a lead compound for the development of novel pharmacological inhibitors against clostridial binary actin ADP-ribosylating toxins. PMID:27043629

EGA Protects Mammalian Cells from Clostridium difficile CDT, Clostridium perfringens Iota Toxin and Clostridium botulinum C2 Toxin.

PubMed

Schnell, Leonie; Mittler, Ann-Katrin; Sadi, Mirko; Popoff, Michel R; Schwan, Carsten; Aktories, Klaus; Mattarei, Andrea; Azarnia Tehran, Domenico; Montecucco, Cesare; Barth, Holger

2016-04-01

The pathogenic bacteria Clostridium difficile, Clostridium perfringens and Clostridium botulinum produce the binary actin ADP-ribosylating toxins CDT, iota and C2, respectively. These toxins are composed of a transport component (B) and a separate enzyme component (A). When both components assemble on the surface of mammalian target cells, the B components mediate the entry of the A components via endosomes into the cytosol. Here, the A components ADP-ribosylate G-actin, resulting in depolymerization of F-actin, cell-rounding and eventually death. In the present study, we demonstrate that 4-bromobenzaldehyde N-(2,6-dimethylphenyl)semicarbazone (EGA), a compound that protects cells from multiple toxins and viruses, also protects different mammalian epithelial cells from all three binary actin ADP-ribosylating toxins. In contrast, EGA did not inhibit the intoxication of cells with Clostridium difficile toxins A and B, indicating a possible different entry route for this toxin. EGA does not affect either the binding of the C2 toxin to the cells surface or the enzyme activity of the A components of CDT, iota and C2, suggesting that this compound interferes with cellular uptake of the toxins. Moreover, for C2 toxin, we demonstrated that EGA inhibits the pH-dependent transport of the A component across cell membranes. EGA is not cytotoxic, and therefore, we propose it as a lead compound for the development of novel pharmacological inhibitors against clostridial binary actin ADP-ribosylating toxins.

Photochemical organic oxidations and dechlorinations with a mu-oxo bridged heme/non-heme diiron complex.

PubMed

Wasser, Ian M; Fry, H Christopher; Hoertz, Paul G; Meyer, Gerald J; Karlin, Kenneth D

2004-12-27

Steady state and laser flash photolysis studies of the heme/non-heme mu-oxo diiron complex [((6)L)Fe(III)-O-Fe(III)-Cl](+) (1) have been undertaken. The anaerobic photolysis of benzene solutions of 1 did not result in the buildup of any photoproduct. However, the addition of excess triphenylphosphine resulted in the quantitative photoreduction of 1 to [((6)L)Fe(II)...Fe(II)-Cl](+) (2), with concomitant production by oxo-transfer of 1 equiv of triphenylphosphine oxide. Under aerobic conditions and excess triphenylphosphine, the reaction produces multiple turnovers (approximately 28) before the diiron complex is degraded. The anaerobic photolysis of tetrahydrofuran (THF) or toluene solutions of 1 likewise results in the buildup of 2. The oxidation products from these reactions included gamma-butyrolactone (approximately 15%) for the reaction in THF and benzaldehyde (approximately 23%) from the reaction in toluene. In either case, the O-atom which is incorporated into the carbonyl product is derived from dioxygen present under workup or under aerobic photolysis conditions. Transient absorption measurements of low-temperature THF solutions of 1 revealed the presence of an (P)Fe(II)-like [P = tetraaryl porphyrinate dianion] species suggesting that the reactive species is a formal (heme)Fe(II)/Fe(IV)=O(non-heme) pair. The non-heme Fe(IV)=O is thus most likely responsible for C-H bond cleavage and subsequent radical chemistry. The photolysis of 1 in chlorobenzene or 1,2-dichlorobenzene resulted in C-Cl cleavage reactions and the formation of [[((6)L)Fe(III)-Cl...Fe(III)-Cl](2)O](2+) (3), with chloride ligands that are derived from solvent dehalogenation chemistry. The resulting organic products are biphenyl trichlorides or biphenyl monochlorides, derived from dichlorobenzene and chlorobenzene, respectively. Similarly, product 3 is obtained by the photolysis of benzene-benzyl chloride solutions of 1; the organic product is benzaldehyde (approximately 70%). A brief discussion of the dehalogenation chemistry, along with relevant environmental perspectives, is included.

Carbonyl emissions in diesel and biodiesel exhaust

NASA Astrophysics Data System (ADS)

Machado Corrêa, Sérgio; Arbilla, Graciela

With the use of biodiesel in clear growth, it is important to quantify any potential emission benefits or liabilities of this fuel. Several researches are available concerning the regulated emissions of biodiesel/diesel blends, but there is a lack of information about non-regulated emissions. In a previous paper [Corrêa, S.M., Arbilla, G., 2006. Emissões de formaldeído e acetaldeído de misturas biodiesel/diesel. Periódico Tchê Química, 3, 54-68], the emissions of aromatic hydrocarbons were reported. In this work, seven carbonyl emissions (formaldehyde, acetaldehyde, acrolein, acetone, propionaldehyde, butyraldehyde, and benzaldehyde) were evaluated by a heavy-duty diesel engine fueled with pure diesel (D) and biodiesel blends (v/v) of 2% (B2), 5% (B5), 10% (B10), and 20% (B20). The tests were conducted using a six cylinder heavy-duty engine, typical of the Brazilian fleet of urban buses, in a steady-state condition under 1000, 1500, and 2000 rpm. The exhaust gases were diluted nearly 20 times and the carbonyls were sampled with SiO 2-C18 cartridges, impregnated with acid solution of 2,4-dinitrophenylhydrazine. The chemical analyses were performed by high performance liquid chromatography using UV detection. Using average values for the three modes of operation (1000, 1500, and 2000 rpm) benzaldehyde showed a reduction on the emission (-3.4% for B2, -5.3% for B5, -5.7% for B10, and -6.9% for B20) and all other carbonyls showed a significative increase: 2.6, 7.3, 17.6, and 35.5% for formaldehyde; 1.4, 2.5, 5.4, and 15.8% for acetaldehyde; 2.1, 5.4, 11.1, and 22.0% for acrolein+acetone; 0.8, 2.7, 4.6, and 10.0% for propionaldehyde; 3.3, 7.8, 16.0, and 26.0% for butyraldehyde.

Observation of volatile and semi-volatile carbonyls in an Algerian urban environment using dinitrophenylhydrazine/silica-HPLC and pentafluorophenylhydrazine/silica-GC-MS.

PubMed

Cecinato, Angelo; Yassaa, Noureddine; Di Palo, Vincenzo; Possanzin, Massimiliano

2002-04-01

Lower carbonyls and n-alkanals from C5 to C10 were measured from late autumn 2000 to summer 2001 in two urban areas in the Algerian territory: Algiers and Ouargla. They were collected on silica cartridges coated with dinitrophenylhydrazine (DNPH) and pentafluorophenylhydrazine (PFPH), which were analysed by HPLC-UV and high-resolution GC-MS. respectively. The two methods were used in parallel samplings in a suburban Algiers site and provided consistent results for semi-volatile congeners, as differences in the concentration data did not exceed 21% on average for individual carbonyl levels ranging from 0.0 to 0.5-2.6 microg m(-3). Concentrations of formaldehyde up to 27 and 5 microg m(-3) were monitored during 10 h samplings in the daytime in Algiers and Ouargla, respectively; acetaldehyde reached values of 13 and 5 microg m(-3), whilst acetone was the most abundant ketone with peak levels of 14 and 4 microg m(-3), respectively. High night-time levels of lower carbonyls were also measured at both locations. Among the semi-volatile alkanals, the highest levels were observed in suburban Algiers for hexanal and nonanal (2.2 microg m(-3)) and in downtown Algiers for valeraldehyde (2.6 microg m(-3)), whilst in Ouargla only hexanal and nonanal levels within the C5-C10 fraction exceeded 1 microg m(-3). Moreover, benzaldehyde concentrations as high as 5 microg m(-3) were measured in the centre of Algiers. Algiers data are comparable with those found in photochemically polluted urban areas of Europe and the USA. Strong correlations between formaldehyde and acetaldehyde and between formaldehyde and benzaldehyde were observed; by contrast, acetone did not show any correlation with the lower aldehydes, suggesting the existence of carbonyl sources other than vehicular traffic. Diurnal variations of almost all carbonyls suggested that motor vehicles were the most important source in the winter, whereas photochemical production appeared to predominate during the summer.

Screening of Polish Fir Honeydew Honey Using GC/MS, HPLC-DAD, and Physical-Chemical Parameters: Benzene Derivatives and Terpenes as Chemical Markers.

PubMed

Kuś, Piotr M; Jerković, Igor; Marijanović, Zvonimir; Tuberoso, Carlo I G

2017-09-01

GC/MS of headspace solid phase micro extraction (HS-SPME) and solvent extractives along with targeted HPLC-DAD of Polish fir (Abies alba Mill.) honeydew honey (FHH), were used to determine the chemical profiles and potential markers of botanical origin. Additionally, typical physical-chemical parameters were also assigned. The values determined for FHH were: conductivity (1.2 mS/cm), water content (16.7 g/100 g), pH (4.5), and CIE chromaticity coordinates (L* = 48.4, a* = 20.6, b* = 69.7, C* = 72.9, and h° = 73.5). FHH contained moderate-high total phenolic content (533.2 mg GAE/kg) and antioxidant activity (1.1 mmol TEAC/kg) and (3.2 mmol Fe 2+ /kg) in DPPH and FRAP assays. The chemical profiles were dominated by source plant-originated benzene derivatives: 3,4-dihydroxybenzoic acid (up to 8.7 mg/kg, HPLC/honey solution), methyl syringate (up to 14.5%, GC/solvent extracts) or benzaldehyde (up to 43.7%, GC/headspace). Other markers were terpenes including norisoprenoid (4-hydroxy-3,5,6-trimethyl-4-(3-oxobut-1-enyl)cyclohex-2-en-1-one, up to 20.3%, GC/solvent extracts) and monoterpenes, mainly linalool derivatives (up to 49%, GC/headspace) as well as borneol (up to 5.9%, GC/headspace). The application of various techniques allowed comprehensive characterisation of FHH. 4-Hydroxy-3,5,6-trimethyl-4-(3-oxobut-1-enyl)cyclohex-2-en-1-one, coniferyl alcohol, borneol, and benzaldehyde were first time proposed for FHH screening. Protocatechuic acid may be a potential marker of FFH regardless of the geographical origin. © 2017 Wiley-VHCA AG, Zurich, Switzerland.

Synthesis of cobalt-containing mesoporous catalysts using the ultrasonic-assisted “pH-adjusting” method: Importance of cobalt species in styrene oxidation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Baitao, E-mail: btli@scut.edu.cn; Zhu, Yanrun; Jin, Xiaojing

2015-01-15

Cobalt-containing SBA-15 and MCM-41 (Co-SBA-15 and Co-MCM-41) mesoporous catalysts were prepared via ultrasonic-assisted “pH-adjusting” technique in this study. Their physiochemical structures were comprehensively characterized and correlated with catalytic activity in oxidation of styrene. The nature of cobalt species depended on the type of mesoporous silica as well as pH values. The different catalytic performance between Co-SBA-15 and Co-MCM-41 catalysts originated from cobalt species. Cobalt species were homogenously incorporated into the siliceous framework of Co-SBA-15 in single-site Co(II) state, while Co{sub 3}O{sub 4} particles were loaded on Co-MCM-41 catalysts. The styrene oxidation tests showed that the single-site Co(II) state was moremore » beneficial to the catalytic oxidation of styrene. The higher styrene conversion and benzaldehyde selectivity over Co-SBA-15 catalysts were mainly attributed to single-site Co(II) state incorporated into the framework of SBA-15. The highest conversion of styrene (34.7%) with benzaldehyde selectivity of 88.2% was obtained over Co-SBA-15 catalyst prepared at pH of 7.5, at the mole ratio of 1:1 (styrene to H{sub 2}O{sub 2}) at 70 °C. - Graphical abstract: Cobalt-containing mesoporous silica catalysts were developed via ultrasonic-assisted “pH-adjusting” technique. Compared with Co{sub 3}O{sub 4} in Co-MCM-41, the single-site Co(II) state in Co-SBA-15 was more efficient for the styrene oxidation. - Highlights: • Fast and cost-effective ultrasonic technique for preparing mesoporous materials. • Incorporation of Co via ultrasonic irradiation and “pH-adjusting”. • Physicochemical comparison between Co-SBA-15 and Co-MCM-41. • Correlation of styrene oxidation activity and catalyst structural property.« less

Characterization of an allylic/benzyl alcohol dehydrogenase from Yokenella sp. strain WZY002, an organism potentially useful for the synthesis of α,β-unsaturated alcohols from allylic aldehydes and ketones.

PubMed

Ying, Xiangxian; Wang, Yifang; Xiong, Bin; Wu, Tingting; Xie, Liping; Yu, Meilan; Wang, Zhao

2014-04-01

A novel whole-cell biocatalyst with high allylic alcohol-oxidizing activities was screened and identified as Yokenella sp. WZY002, which chemoselectively reduced the C=O bond of allylic aldehydes/ketones to the corresponding α,β-unsaturated alcohols at 30°C and pH 8.0. The strain also had the capacity of stereoselectively reducing aromatic ketones to (S)-enantioselective alcohols. The enzyme responsible for the predominant allylic/benzyl alcohol dehydrogenase activity was purified to homogeneity and designated YsADH (alcohol dehydrogenase from Yokenella sp.), which had a calculated subunit molecular mass of 36,411 Da. The gene encoding YsADH was subsequently expressed in Escherichia coli, and the purified recombinant YsADH protein was characterized. The enzyme strictly required NADP(H) as a coenzyme and was putatively zinc dependent. The optimal pH and temperature for crotonaldehyde reduction were pH 6.5 and 65°C, whereas those for crotyl alcohol oxidation were pH 8.0 and 55°C. The enzyme showed moderate thermostability, with a half-life of 6.2 h at 55°C. It was robust in the presence of organic solvents and retained 87.5% of the initial activity after 24 h of incubation with 20% (vol/vol) dimethyl sulfoxide. The enzyme preferentially catalyzed allylic/benzyl aldehydes as the substrate in the reduction of aldehydes/ketones and yielded the highest activity of 427 U mg(-1) for benzaldehyde reduction, while the alcohol oxidation reaction demonstrated the maximum activity of 79.9 U mg(-1) using crotyl alcohol as the substrate. Moreover, kinetic parameters of the enzyme showed lower Km values and higher catalytic efficiency for crotonaldehyde/benzaldehyde and NADPH than for crotyl alcohol/benzyl alcohol and NADP(+), suggesting the nature of being an aldehyde reductase.

Characterization of an Allylic/Benzyl Alcohol Dehydrogenase from Yokenella sp. Strain WZY002, an Organism Potentially Useful for the Synthesis of α,β-Unsaturated Alcohols from Allylic Aldehydes and Ketones

PubMed Central

Ying, Xiangxian; Wang, Yifang; Xiong, Bin; Wu, Tingting; Xie, Liping; Yu, Meilan

2014-01-01

A novel whole-cell biocatalyst with high allylic alcohol-oxidizing activities was screened and identified as Yokenella sp. WZY002, which chemoselectively reduced the C=O bond of allylic aldehydes/ketones to the corresponding α,β-unsaturated alcohols at 30°C and pH 8.0. The strain also had the capacity of stereoselectively reducing aromatic ketones to (S)-enantioselective alcohols. The enzyme responsible for the predominant allylic/benzyl alcohol dehydrogenase activity was purified to homogeneity and designated YsADH (alcohol dehydrogenase from Yokenella sp.), which had a calculated subunit molecular mass of 36,411 Da. The gene encoding YsADH was subsequently expressed in Escherichia coli, and the purified recombinant YsADH protein was characterized. The enzyme strictly required NADP(H) as a coenzyme and was putatively zinc dependent. The optimal pH and temperature for crotonaldehyde reduction were pH 6.5 and 65°C, whereas those for crotyl alcohol oxidation were pH 8.0 and 55°C. The enzyme showed moderate thermostability, with a half-life of 6.2 h at 55°C. It was robust in the presence of organic solvents and retained 87.5% of the initial activity after 24 h of incubation with 20% (vol/vol) dimethyl sulfoxide. The enzyme preferentially catalyzed allylic/benzyl aldehydes as the substrate in the reduction of aldehydes/ketones and yielded the highest activity of 427 U mg−1 for benzaldehyde reduction, while the alcohol oxidation reaction demonstrated the maximum activity of 79.9 U mg−1 using crotyl alcohol as the substrate. Moreover, kinetic parameters of the enzyme showed lower Km values and higher catalytic efficiency for crotonaldehyde/benzaldehyde and NADPH than for crotyl alcohol/benzyl alcohol and NADP+, suggesting the nature of being an aldehyde reductase. PMID:24509923

(E)-2′-[(3,5-Di-tert-butyl-2-hy­droxy­benzyl­idene)amino]-1,1′-binaphthalen-2-ol methanol monosolvate

PubMed Central

He, Dian; Li, Chong; Wang, Xiaohong

2011-01-01

The title compound, C35H35NO2·CH4O, was obtained by the reaction of rac-2-amino-2-hy­droxy-1,1-binaphthyl and 3,5-di-tert-butyl-2-hy­droxy­benzaldehyde in absolute methanol. In the Schiff base mol­ecule, the two naphthyl bicycles are twisted by 71.15 (5)°. One hy­droxy group is involved in intra­molecular O—H⋯N hydrogen bond, while the methanol solvent mol­ecule is linked to another hy­droxy group via an inter­molecular O—H⋯O hydrogen bond. PMID:22219946

A matrix-focused structure-activity and binding site flexibility study of quinolinol inhibitors of botulinum neurotoxin serotype A.

PubMed

Harrell, William A; Vieira, Rebecca C; Ensel, Susan M; Montgomery, Vicki; Guernieri, Rebecca; Eccard, Vanessa S; Campbell, Yvette; Roxas-Duncan, Virginia; Cardellina, John H; Webb, Robert P; Smith, Leonard A

2017-02-01

Our initial discovery of 8-hydroxyquinoline inhibitors of BoNT/A and separation/testing of enantiomers of one of the more active leads indicated considerable flexibility in the binding site. We designed a limited study to investigate this flexibility and probe structure-activity relationships; utilizing the Betti reaction, a 36 compound matrix of quinolinol BoNT/A LC inhibitors was developed using three 8-hydroxyquinolines, three heteroaromatic amines, and four substituted benzaldehydes. This study has revealed some of the most effective quinolinol-based BoNT/A inhibitors to date, with 7 compounds displaying IC 50 values ⩽1μM and 11 effective at ⩽2μM in an ex vivo assay. Published by Elsevier Ltd.

Impact of ultrasound on hydrophobic interactions in solutions: ultrasonic retardation of benzoin condensation.

PubMed

Hagu, Hannes; Salmar, Siim; Tuulmets, Ants

2007-04-01

Kinetics of the benzoin condensation of benzaldehyde in presence of KCN as the catalyst in water and in ethanol-water binary solutions were investigated without sonication and under ultrasound at 22 kHz. A statistically significant 20% decrease of the rate was observed in water. The retardation effect of ultrasound gradually decreases up to 45 wt% ethanol content. We report an evidence of ultrasonic retardation of reactions and thereby a direct evidence for sonochemical processes in the bulk solution. Ultrasound can disturb solvation of the species in the solution. If breaking down the stabilization of the encounter complexes between the reagents, sonication hinders the reaction while perturbation of the solvent-stabilization of the reagents accelerates the reaction.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bell, Stephen G.; Hoskins, Nicola; Xu Feng

Four (CYP195A2, CYP199A2, CYP203A1, and CYP153A5) of the seven P450 enzymes, and palustrisredoxin A, a ferredoxin associated with CYP199A2, from the metabolically diverse bacterium Rhodopseudomonas palustris have been expressed and purified. A range of substituted benzenes, phenols, benzaldehydes, and benzoic acids was shown to bind to the four P450 enzymes. Monooxygenase activity of CYP199A2 was reconstituted with palustrisredoxin A and putidaredoxin reductase of the P450cam system from Pseudomonas putida. We found that 4-ethylbenzoate and 4-methoxybenzoate were oxidized to single products, and 4-methoxybenzoate was demethylated to form 4-hydroxybenzoate. Crystals of substrate-free CYP199A2 which diffracted to {approx}2.0 A have been obtained.

Synthesis of new chalcone derivatives and their antimicrobial studies

NASA Astrophysics Data System (ADS)

Noorulhaq, Syed Shah Najib; Baseer, Mohammad Abdul

2017-11-01

Chalcones are the significant constituent of natural sources. Chalcones posses 1,3-diaryl-1-ones frame which withdraws the recognition of biological importance. Chalcones are not possible to separate from plants because it is transformed into flavonones due to the presence of enzyme chalcone synthetase. Chalcones are prepared by the Claisen-Schimdt condensation of equimolar ratios of aldehyde and ketone in presence of base. With this vision we accounted here the synthesis of some novel chalcones via Clasien-Schimdt condensation of substituted ketones containing hydroxy, chloro, fluoro groups and 4-(4-Methyl-piperazin-1-yl)-benzaldehyde in presence of alkali at room temperature. These recently synthesized γ, β unsaturated compounds that is chalcones were screened for their antimicrobial studies which show modest to good activity.

Bis(N'-{(E)-[(2E)-1,3-di-phenyl-prop-2-en-1-yl-idene]amino}-N-ethyl-carbamimido-thio-ato-κ2N',S)zinc(II): crystal structure and Hirshfeld surface analysis.

PubMed

Tan, Ming Yueh; Crouse, Karen A; Ravoof, Thahira B S A; Jotani, Mukesh M; Tiekink, Edward R T

2017-07-01

The title Zn II complex, [Zn(C 18 H 18 N 3 S) 2 ], (I), features two independent but chemically equivalent mol-ecules in the asymmetric unit. In each, the thio-semicarbazonate monoanion coordinates the Zn II atom via the thiol-ate-S and imine-N atoms, with the resulting N 2 S 2 donor set defining a distorted tetra-hedral geometry. The five-membered ZnSCN 2 chelate rings adopt distinct conformations in each independent mol-ecule, i.e. one ring is almost planar while the other is twisted about the Zn-S bond. In the crystal, the two mol-ecules comprising the asymmetric unit are linked by amine-N-H⋯N(imine) and amine-N-H⋯S(thiol-ate) hydrogen bonds via an eight-membered heterosynthon, {⋯HNCN⋯HNCS}. The dimeric aggregates are further consolidated by benzene-C-H⋯S(thiol-ate) inter-actions and are linked into a zigzag supra-molecular chain along the c axis via amine-N-H⋯S(thiol-ate) hydrogen bonds. The chains are connected into a three-dimensional architecture via phenyl-C-H⋯π(phen-yl) and π-π inter-actions, the latter occurring between chelate and phenyl rings [inter-centroid separation = 3.6873 (11) Å]. The analysis of the Hirshfeld surfaces calculated for (I) emphasizes the different inter-actions formed by the independent mol-ecules in the crystal and the impact of the π-π inter-actions between chelate and phenyl rings.

Simultaneous quantification of preactivated ifosfamide derivatives and of 4-hydroxyifosfamide by high performance liquid chromatography-tandem mass spectrometry in mouse plasma and its application to a pharmacokinetic study.

PubMed

Deroussent, Alain; Skarbek, Charles; Maury, Adeline; Chapuis, Hubert; Daudigeos-Dubus, Estelle; Le Dret, Ludivine; Durand, Sylvère; Couvreur, Patrick; Desmaële, Didier; Paci, Angelo

2015-06-15

The antitumor drug, ifosfamide (IFO), requires activation by cytochrome P450 (CYP) to form the active metabolite, 4-hydroxyisfosfamide (4-OHIFO), leading to toxic by-products at high dose. In order to overcome these drawbacks, preactivated ifosfamide derivatives (RXIFO) were designed to release 4-OHIFO without CYP involvement. A high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method was developed for the simultaneous quantification of 4-OHIFO, IFO and four derivatives RXIFO in mouse plasma using multiple reaction monitoring. Because of its instability in plasma, 4-OHIFO was immediately converted to the semi-carbazone derivative, 4-OHIFO-SCZ. For the six analytes, the calibration curves were linear from 20 to 5000ng/mL in 50μL plasma and the lower limit of quantitation was determined at 20ng/mL with accuracies within ±10% of nominal and precisions less than 12%. Their recoveries ranged from 62 to 96% by using liquid-liquid extraction. With an improved assay sensitivity compared to analogues, the derivative 4-OHIFO-SCZ was stable in plasma at 4°C for 24h and at -20°C for three months. For all compounds, the assay was validated with accuracies within ±13% and precisions less than 15%. This method was applied to a comparative pharmacokinetic study of 4-OHIFO from IFO and three derivatives RXIFO in mice. This active metabolite was produced by some of the novel conjugates with good pharmacokinetic properties. Copyright © 2015 Elsevier B.V. All rights reserved.

The pheromone production of female Plodia interpunctella is inhibited by tyraminergic antagonists.

PubMed

Hirashima, Akinori; Kimizu, Megumi; Shigeta, Yoko; Matsugu, Sachiko; Eiraku, Tomohiko; Kuwano, Eiichi; Eto, Morifusa

2004-11-01

Several compounds were found to suppress the calling behavior and in vitro pheromone biosynthesis of the Indian meal moth, Plodia interpunctella. The compounds were screened by means of a calling-behavior bioassay with female P. interpunctella. Five derivatives with activities in the nanomolar range were identified, in order of decreasing pheromonostatic activity: 4-hydroxybenzaldehyde semicarbazone (42) > 5-(4-methoxyphenyl)-1,3-oxazole (38) > 5-[4-(tert-butyl)phenyl]-1,3-oxazole (40) > 5-(3-methoxyphenyl)-1,3-oxazole (35) > 5-(4-cyanophenyl)-1,3-oxazole (36). These compounds also showed in vitro inhibitory activity in intracellular de novo pheromone biosynthesis, as determined with isolated pheromone-gland preparations that incorporated [1-(14)C]sodium acetate in the presence of the so-called pheromone-biosynthesis-activating neuropeptide (PBAN). The non-additive effect of the inhibitor with antagonist (yohimbine) for the tyramine (TA) receptor suggests that it could be a tyraminergic antagonist. Three-dimensional (3D) computer models were built from a set of compounds. Among the common-featured models generated by the program Catalyst/HipHop, aromatic-ring (AR) and H-bond-acceptor-lipophilic (HBAl) features were considered to be essential for inhibitory activity in the calling behavior and in vitro pheromone biosynthesis. Active compounds, including yohimbine, mapped well onto all the AR and HBAl features of the hypothesis. Less-active compounds were shown to be unable to achieve an energetically favorable conformation, consistent with our 3D common-feature pharmacophore models. The present hypothesis demonstrates that calling behavior and PBAN-stimulated incorporation of radioactivity are inhibited by tyraminergic antagonists.

Ni-Catalyzed Carbon-Carbon Bond-Forming Reductive Amination.

PubMed

Heinz, Christoph; Lutz, J Patrick; Simmons, Eric M; Miller, Michael M; Ewing, William R; Doyle, Abigail G

2018-02-14

This report describes a three-component, Ni-catalyzed reductive coupling that enables the convergent synthesis of tertiary benzhydryl amines, which are challenging to access by traditional reductive amination methodologies. The reaction makes use of iminium ions generated in situ from the condensation of secondary N-trimethylsilyl amines with benzaldehydes, and these species undergo reaction with several distinct classes of organic electrophiles. The synthetic value of this process is demonstrated by a single-step synthesis of antimigraine drug flunarizine (Sibelium) and high yielding derivatization of paroxetine (Paxil) and metoprolol (Lopressor). Mechanistic investigations support a sequential oxidative addition mechanism rather than a pathway proceeding via α-amino radical formation. Accordingly, application of catalytic conditions to an intramolecular reductive coupling is demonstrated for the synthesis of endo- and exocyclic benzhydryl amines.

Functionalized SBA-15 supported nickel (II)-oxime-imine catalysts for liquid phase oxidation of olefins under solvent-free conditions

NASA Astrophysics Data System (ADS)

Paul, Luna; Banerjee, Biplab; Bhaumik, Asim; Ali, Mahammad

2016-05-01

A new oxime-imine functionalized highly ordered mesoporous SBA-15 (SBA-15-NH2-DAMO) has been synthesized via post-synthesis functionalization of SBA-15 with 3-aminopropyl-triethoxysilane followed by the Schiff base condensation with diacetylmonooxime, which was further reacted with Ni(ClO4)2 to yield the functionalized nickel catalyst SBA-15-NH2-DAMO-Ni. All the synthesized materials were thoroughly characterized using different characterization techniques. It was found that SBA-15-NH2-DAMO-Ni catalyzes the one-pot oxidation of olefins like styrene, cyclohexene, cyclooctene, 1-hexene and 1-octene to the corresponding benzaldehyde, cyclohexene-1-ol and cyclooctene-oxide, respectively under solvent-free conditions by using tert-butylhydroperoxide as oxidant.

Synthesis and characterization of a novel schiff base of 1,2-diaminopropane with substituted salicyaldehyde and its transition metal complexes: Single crystal structures and biological activities

NASA Astrophysics Data System (ADS)

Tadavi, Samina K.; Yadav, Abhijit A.; Bendre, Ratnamala S.

2018-01-01

A novel schiff base H2L derived from simple condensation of 2-hydroxy-6-isopropyl-3-methyl benzaldehyde and 1,2-diaminopropane in 2:1 M ratio and its [MnL], [CoL] and [NiL]2 complexes have been prepared and characterized by spectroscopic technique, elemental analysis, SEM-EDX analysis, and cyclic voltammetry. Additionally, single crystal X-ray diffraction technique has been applied to the schiff base ligand H2L and its nickel complex. The structure of nickel complex exhibited dimeric form with formula [NiL]2 with distorted square planar geometry around each nickel center. Furthermore, all the synthesized compounds were screened for their antimicrobial and antioxidant and DNA cleavage activities.

Gold Nanoparticles Supported on a Layered Double Hydroxide as Efficient Catalysts for the One-Pot Synthesis of Flavones.

PubMed

Yatabe, Takafumi; Jin, Xiongjie; Yamaguchi, Kazuya; Mizuno, Noritaka

2015-11-02

Flavones are a class of natural products with diverse biological activities and have frequently been synthesized by step-by-step procedures using stoichiometric amounts of reagents. Herein, a catalytic one-pot procedure for the synthesis of flavone and its derivatives is developed. In the presence of gold nanoparticles supported on a Mg-Al layered double hydroxide (Au/LDH), various kinds of flavones can be synthesized starting from 2'-hydroxyacetophenones and benzaldehydes (or benzyl alcohols). The present one-pot procedure consists of a sequence of several reactions, and Au/LDH can catalyze all these different types of reactions. The catalysis is shown to be truly heterogeneous, and Au/LDH can be readily recovered and reused. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Characterizing the Smell of Marijuana by Odor Impact of Volatile Compounds: An Application of Simultaneous Chemical and Sensory Analysis

PubMed Central

2015-01-01

Recent US legislation permitting recreational use of marijuana in certain states brings the use of marijuana odor as probable cause for search and seizure to the forefront of forensic science, once again. This study showed the use of solid-phase microextraction with multidimensional gas chromatography—mass spectrometry and simultaneous human olfaction to characterize the total aroma of marijuana. The application of odor activity analysis offers an explanation as to why high volatile chemical concentration does not equate to most potent odor impact of a certain compound. This suggests that more attention should be focused on highly odorous compounds typically present in low concentrations, such as nonanal, decanol, o-cymene, benzaldehyde, which have more potent odor impact than previously reported marijuana headspace volatiles. PMID:26657499

Synthesis, characterization and application of a nano-manganese-catalyst as an efficient solid catalyst for solvent free selective oxidation of ethylbenzene, cyclohexene, and benzylalcohol

NASA Astrophysics Data System (ADS)

Habibi, Davood; Faraji, Ali Reza

2013-07-01

The object of this study is to synthesize the heterogeneous Mn-nano-catalyst (MNC) which has been covalently anchored on a modified nanoscaleSiO2/Al2O3, and characterized by FT-IR, UV-Vis, CHN elemental analysis, EDS, TEM, and EDX. The method is efficient for the highly selective oxidation of ethylbenzene, cyclohexene, and benzylalcohol without the need to any solvents, using tert-butyl hydroperoxide (TBHP) as an oxidant. Oxidation of ethylbenzene, cyclohexene, and benzylalcohol gave acetophenone, 2-cyclohexene-1-one and benzaldehyde, respectively, as major products. Reaction conditions have been optimized by considering the effect of various factors such as reaction time, amounts of substrates and oxidant, Mn-nano-catalyst and application of various solvents.

Flavonoids and other constituents from Aletris spicata and their chemotaxonomic significance.

PubMed

Li, Lin-Zhen; Wang, Meng-Hua; Sun, Jian-Bo; Liang, Jing-Yu

2014-01-01

Eleven compounds, including four flavonoids [(2R,3R)-2,3-dihydro-3,5-dihydroxy-7,4'-dimethoxyflavone (1), 5-hydroxy-7,8,4'-trimethoxy-flavone (2), amentoflavone (10) and apigenin (11)], two penylpropanoids [sinapaldehyde (3) and 3-methoxy-4-hydroxy-cinnamic aldehyde (4)], three phenolic acids [4-hydroxyl-3,5-dimethoxy-benzaldehyde (5), 4-hydroxyacetophen-one (6) and p-hydroxybenzaldehyde (7)], one furan derivative [5-hydroxymethyl furfural (8)] and one steroid saponin [β-sitosterol-3-O-β-d-glucoside (9)], were isolated and identified from Aletris spicata. Among them, compounds 1-7, 9 and 10 were reported from the genus Aletris for the first time. Furthermore, seven of them (1-6, 10) were obtained from the family Liliaceae for the first time. Chemotaxonomy of the isolated compounds is discussed briefly.

Myoglobin-Catalyzed Olefination of Aldehydes.

PubMed

Tyagi, Vikas; Fasan, Rudi

2016-02-12

The olefination of aldehydes constitutes a most valuable and widely adopted strategy for constructing carbon-carbon double bonds in organic chemistry. While various synthetic methods have been made available for this purpose, no biocatalysts are known to mediate this transformation. Reported herein is that engineered myoglobin variants can catalyze the olefination of aldehydes in the presence of α-diazoesters with high catalytic efficiency (up to 4,900 turnovers) and excellent E diastereoselectivity (92-99.9 % de). This transformation could be applied to the olefination of a variety of substituted benzaldehydes and heteroaromatic aldehydes, also in combination with different alkyl α-diazoacetate reagents. This work provides a first example of biocatalytic aldehyde olefination and extends the spectrum of synthetically valuable chemical transformations accessible using metalloprotein-based catalysts. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Surface chemistry of aromatic reactants on Pt- and Mo-modified Pt catalysts

DOE Office of Scientific and Technical Information (OSTI.GOV)

Robinson, Allison M.; Mark, Lesli; Rasmussen, Mathew J.

Supported catalysts containing an oxophilic metal such as Mo and a noble metal such as Pt have shown promising activity and selectivity for deoxygenation of biomass-derived compounds. Here, we report that PtMo catalysts also promote hydrogenolysis of the model compound benzyl alcohol, while decarbonylation is most prevalent over unmodified Pt. A combination of single crystal surface science studies, density functional theory (DFT) calculations, and vapor phase upgrading experiments using supported catalysts was carried out to better understand the mechanism by which Mo promotes deoxygenation. Molybdenum was deposited in submonolayer quantities on a Pt(111) surface and reduced at high temperature. Temperature-programmedmore » desorption (TPD) experiments using benzyl alcohol as a reactant showed greatly enhanced yields of the deoxygenation product toluene at moderate Mo coverages. To understand how the interaction of the aromatic group with the surface influenced this reactivity, we investigated the adsorption of toluene as a probe molecule. We found that the addition of Mo to Pt(111) resulted in a significant decrease in toluene decomposition. DFT calculations indicated that this decrease was consistent with decreased aromatic adsorption strengths that accompany incorporation of Mo into the Pt subsurface. The weaker aromatic-surface interaction on Pt/Mo surfaces led to a tilted adsorption geometry for benzyl alcohol, which presumably promotes hydrogenolysis to produce toluene instead of decarbonylation to produce benzene and CO. Alumina-supported Pt and PtMo catalysts were also tested for benzyl alcohol deoxygenation. PtMo catalysts had a higher rate of toluene production and lower rates of benzene and benzaldehyde production. Additionally, when benzaldehyde was used as the reactant to measure decarbonylation activity the mass-normalized rate of benzene production was 2.5 times higher on Pt than PtMo. Altogether, the results of TPD, DFT, and supported catalyst experiments suggest that subsurface Mo sites weaken the binding of aromatic rings on PtMo surfaces; the weakened aromatic-surface interaction is correlated with an improvement in selectivity to C-O bond scission.« less

Surface chemistry of aromatic reactants on Pt- and Mo-modified Pt catalysts

DOE PAGES

Robinson, Allison M.; Mark, Lesli; Rasmussen, Mathew J.; ...

2016-11-01

Supported catalysts containing an oxophilic metal such as Mo and a noble metal such as Pt have shown promising activity and selectivity for deoxygenation of biomass-derived compounds. Here, we report that PtMo catalysts also promote hydrogenolysis of the model compound benzyl alcohol, while decarbonylation is most prevalent over unmodified Pt. A combination of single crystal surface science studies, density functional theory (DFT) calculations, and vapor phase upgrading experiments using supported catalysts was carried out to better understand the mechanism by which Mo promotes deoxygenation. Molybdenum was deposited in submonolayer quantities on a Pt(111) surface and reduced at high temperature. Temperature-programmedmore » desorption (TPD) experiments using benzyl alcohol as a reactant showed greatly enhanced yields of the deoxygenation product toluene at moderate Mo coverages. To understand how the interaction of the aromatic group with the surface influenced this reactivity, we investigated the adsorption of toluene as a probe molecule. We found that the addition of Mo to Pt(111) resulted in a significant decrease in toluene decomposition. DFT calculations indicated that this decrease was consistent with decreased aromatic adsorption strengths that accompany incorporation of Mo into the Pt subsurface. The weaker aromatic-surface interaction on Pt/Mo surfaces led to a tilted adsorption geometry for benzyl alcohol, which presumably promotes hydrogenolysis to produce toluene instead of decarbonylation to produce benzene and CO. Alumina-supported Pt and PtMo catalysts were also tested for benzyl alcohol deoxygenation. PtMo catalysts had a higher rate of toluene production and lower rates of benzene and benzaldehyde production. Additionally, when benzaldehyde was used as the reactant to measure decarbonylation activity the mass-normalized rate of benzene production was 2.5 times higher on Pt than PtMo. Altogether, the results of TPD, DFT, and supported catalyst experiments suggest that subsurface Mo sites weaken the binding of aromatic rings on PtMo surfaces; the weakened aromatic-surface interaction is correlated with an improvement in selectivity to C-O bond scission.« less

Ethyl 4-anilino-2,6-bis­(4-chloro­phen­yl)-1-phenyl-1,2,5,6-tetra­hydro­pyridine-3-carboxyl­ate

PubMed Central

Yu, Jianfeng; Tang, Shiming; Zeng, Jingbin; Yan, Zifeng

2013-01-01

The title compound, C32H28Cl2N2O2, was synthesized by a multicomponent reaction of 4-chloro­benzaldehyde, aniline and ethyl aceto­acetate. The central 1,2,5,6-tetra­hydro­pyridine ring exhibits a distorted boat conformation and the two chloro­phenyl rings attached to the central ring at positions 2 and 6 are oriented in opposite directions. The two O atoms of the eth­oxy­carbonyl group are involved in intra­molecular N—H⋯O and C—H⋯O hydrogen bonds. In the crystal, weak C—H⋯O hydrogen bonds link mol­ecules related by translation along the b axis into chains. PMID:23795109

Improved Catalytic Activity and Stability of a Palladium Pincer Complex by Incorporation into a Metal-Organic Framework.

PubMed

Burgess, Samantha A; Kassie, Abebu; Baranowski, Sarah A; Fritzsching, Keith J; Schmidt-Rohr, Klaus; Brown, Craig M; Wade, Casey R

2016-02-17

A porous metal-organic framework Zr6O4(OH)4(L-PdX)3 (1-X) has been constructed from Pd diphosphinite pincer complexes ([L-PdX](4-) = [(2,6-(OPAr2)2C6H3)PdX](4-), Ar = p-C6H4CO2(-), X = Cl, I). Reaction of 1-X with PhI(O2CCF3)2 facilitates I(-)/CF3CO2(-) ligand exchange to generate 1-TFA and I2 as a soluble byproduct. 1-TFA is an active and recyclable catalyst for transfer hydrogenation of benzaldehydes using formic acid as a hydrogen source. In contrast, the homogeneous analogue (t)Bu(L-PdTFA) is an ineffective catalyst owing to decomposition under the catalytic conditions, highlighting the beneficial effects of immobilization.

A pure inorganic 1D chain based on {Mo8O28} clusters and Mn(II) ions: [Mn(H2O)2Mo8O28 ] n 6 n -

NASA Astrophysics Data System (ADS)

Zhang, Xiaofen; Yan, Yonghong; Wu, Lizhou; Yu, Chengxin; Dong, Xinbo; Hu, Huaiming; Xue, Ganglin

2016-01-01

A new pure inorganic polymer, (NH4)6n[Mn(H2O)2Mo8O28)]n(H2O)2n(1), has been synthesized and characterized by elemental analyses, IR spectrum, UV-vis absorption spectra, TG-DSC and electrochemical studies. In 1, [Mo8O28]8- anions act as tetradentate ligands and are alternately linked by Mn(H2O)2 2 + ions into a one-dimensional chain structure. It is interesting that 1 represents the first example of pure inorganic-inorganic hybrid based on octamolybdate and transition metal ions. Moreover, it was indicated that 1 had definite catalytic activities on the probe reaction of benzyl alcohol oxidation to benzaldehyde with H2O2.

Nanoscale Assembly of Actuating Cilia-Mimetic

NASA Astrophysics Data System (ADS)

Baird, Lance; Breidenich, Jennifer; Land, Bruce; Hayes, Allen; Benkoski, Jason; Keng, Pei; Pyun, Jeffrey

2009-03-01

The cilium is among the smallest mechanical actuators found in nature. We have taken inspiration from this design to create magnetic nanochains, measuring approximately 1-5 μm long and 25 nm in diameter. Fabricated from the self-assembly of cobalt nanoparticles, these flexible filaments actuate in an oscillating magnetic field. The cobalt nanoparticles were functionalized with a polystyrene/benzaldehyde surface coating, thus allowing the particles to form imine bonds with one another in the presence of a diamine terminated polyethylene glycol. These imine bonds effectively cross-linked the particles and held the nanochains together in the absence of a magnetic field. Using design of experiments (DOE) to efficiently screen the effects of cobalt nanoparticle concentration, crosslinker concentration, and surface chemistry, we determined that the morphology of the final structures could be explained primarily by physical interactions (i.e. magnetic forces) rather than chemistry.

Bimetallic Cu-Ni nanoparticles supported on activated carbon for catalytic oxidation of benzyl alcohol

NASA Astrophysics Data System (ADS)

Kimi, Melody; Jaidie, Mohd Muazmil Hadi; Pang, Suh Cem

2018-01-01

A series of bimetallic copper-nickel (CuNix, x = 0.1, 0.2, 0.5 and 1) nanoparticles supported on activated carbon (AC) were prepared by deposition-precipitation method for the oxidation of benzyl alcohol to benzaldehyde using hydrogen peroxide as oxidising agent. Analyses by means of X-ray Diffraction (XRD) and Scanning Electron Microscopy (SEM) confirmed that Cu and Ni was successfully added on the surface of activated carbon. CuNi1/AC showed the best catalytic activity for the oxidation of benzyl alcohols to the corresponding aldehyde within a short reaction period at 80 °C. The catalytic performance is significantly enhanced by the addition of equal amount of Ni as compared to the monometallic counterpart. This result indicates the synergistic effect between Ni and Cu particles in the catalytic oxidation reaction.

Method of acetaldehyde measurement with minimal artifactual formation in red blood cells and plasma of actively drinking subjects with alcoholism.

PubMed

Hernandez-Munoz, R; Ma, X L; Baraona, E; Lieber, C S

1992-07-01

After alcohol consumption, a substantial amount of acetaldehyde that is reversibly bound to protein and nonprotein components of the red blood cells circulates in the blood and could cause extrahepatic toxicity. However, acetaldehyde measurement in human red blood cells is hampered by considerable ex vivo artifactual formation as a result of nonenzymatic oxidation of ethanol during protein precipitation. To eliminate this source of artifactual formation, free and reversibly bound acetaldehyde were trapped with semicarbazide from red blood cell hemolysates, and both the stroma and the hemoglobin were sequentially removed by centrifugation and ion-exchange chromatography in carboxymethyl Sephadex, respectively. The eluted semi-carbazone was dissociated with perchloric acid, and the acetaldehyde that was released in the protein-free supernatants was measured by head-space gas chromatography. Maximal retention of hemoglobin by carboxymethyl Sephadex and complete recovery of acetaldehyde and ethanol were achieved at a pH of 5.3. The artifactual formation decreased from 2.62 +/- 0.32 mumol of acetaldehyde per millimole of ethanol in the initial hemolysates to 1.38 +/- 0.20 mumol after removal of the stroma and to a level that is comparable to measurements in plasma (0.09 +/- 0.02 mumol) after removal of both the stroma and the hemoglobin. In 12 actively drinking subjects with alcoholism, with blood ethanol levels that ranged between 9 and 81 mmol/L, the concentrations of acetaldehyde in red blood cells (11.50 +/- 1.46 mumol/L; range: 7.5 to 22 mumol/L) were minimally affected by blood ethanol levels and were three times as high as those in the plasma (3.74 +/- 1.49 mumol/L).(ABSTRACT TRUNCATED AT 250 WORDS)

Comparison of metabolic pathways of different α-N-heterocyclic thiosemicarbazones.

PubMed

Pelivan, Karla; Frensemeier, Lisa M; Karst, Uwe; Koellensperger, Gunda; Heffeter, Petra; Keppler, Bernhard K; Kowol, Christian R

2018-03-01

Clinical failure of novel drugs is often related to their rapid metabolism and excretion. This highlights the importance of elucidation of their pharmacokinetic profile already at the preclinical stage of drug development. Triapine, the most prominent representative of α-N-heterocyclic thiosemicarbazones, was investigated in more than 30 clinical phase I/II trials, but the results against solid tumors were disappointing. Recent investigations from our group suggested that this is, at least partially, based on the fast metabolism and excretion. In order to establish more detailed structure/activity/metabolism relationships, herein a panel of 10 different Triapine derivatives was investigated for their metabolic pathways. From the biological point of view, the panel consists of terminally dimethylated thiosemicarbazones with nanomolar IC 50 values, derivatives with micromolar cytotoxicities comparable to Triapine and a completely inactive representative. To study the oxidative metabolism, a purely instrumental approach based on electrochemistry/mass spectrometry was applied and the results were compared to the data obtained from microsomal incubations. Overall, the investigated thiosemicarbazones underwent the phase I metabolic reactions dehydrogenation, hydroxylation, oxidative desulfuration (to semicarbazone and amidrazone) and demethylation. Notably, dehydrogenation resulted in a ring-closure reaction with formation of thiadiazoles. Although strong differences between the metabolic pathways of the different thiosemicarbazones were observed, they could not be directly correlated to their cytotoxicities. Finally, the metabolic pathways for the most cytotoxic compound were elucidated also in tissues collected from drug-treated mice, confirming the data obtained by electrochemical oxidation and microsomes. In addition, the in vivo experiments revealed a very fast metabolism and excretion of the compound. Graphical abstract Structure/activity/metabolisation relationships for 10 anticancer thiosemicarbazones were established using electrochemical oxidation coupled to mass spectrometry (EC-MS) and human liver microsomes analyzed by LC-MS.

One-step synthesis of highly efficient nanocatalysts on the supports with hierarchical pores using porous ionic liquid-water gel.

PubMed

Kang, Xinchen; Zhang, Jianling; Shang, Wenting; Wu, Tianbin; Zhang, Peng; Han, Buxing; Wu, Zhonghua; Mo, Guang; Xing, Xueqing

2014-03-12

Stable porous ionic liquid-water gel induced by inorganic salts was created for the first time. The porous gel was used to develop a one-step method to synthesize supported metal nanocatalysts. Au/SiO2, Ru/SiO2, Pd/Cu(2-pymo)2 metal-organic framework (Cu-MOF), and Au/polyacrylamide (PAM) were synthesized, in which the supports had hierarchical meso- and macropores, the size of the metal nanocatalysts could be very small (<1 nm), and the size distribution was very narrow even when the metal loading amount was as high as 8 wt %. The catalysts were extremely active, selective, and stable for oxidative esterification of benzyl alcohol to methyl benzoate, benzene hydrogenation to cyclohexane, and oxidation of benzyl alcohol to benzaldehyde because they combined the advantages of the nanocatalysts of small size and hierarchical porosity of the supports. In addition, this method is very simple.

Differential presence of anthropogenic compounds dissolved in the marine waters of Puget Sound, WA and Barkley Sound, BC.

PubMed

Keil, Richard; Salemme, Keri; Forrest, Brittany; Neibauer, Jaqui; Logsdon, Miles

2011-11-01

Organic compounds were evaluated in March 2010 at 22 stations in Barkley Sound, Vancouver Island Canada and at 66 locations in Puget Sound. Of 37 compounds, 15 were xenobiotics, 8 were determined to have an anthropogenic imprint over natural sources, and 13 were presumed to be of natural or mixed origin. The three most frequently detected compounds were salicyclic acid, vanillin and thymol. The three most abundant compounds were diethylhexyl phthalate (DEHP), ethyl vanillin and benzaldehyde (∼600 n g L(-1) on average). Concentrations of xenobiotics were 10-100 times higher in Puget Sound relative to Barkley Sound. Three compound couplets are used to illustrate the influence of human activity on marine waters; vanillin and ethyl vanillin, salicylic acid and acetylsalicylic acid, and cinnamaldehyde and cinnamic acid. Ratios indicate that anthropogenic activities are the predominant source of these chemicals in Puget Sound. Published by Elsevier Ltd.

Nematicidal activity of plant essential oils and components from coriander (Coriandrum sativum), Oriental sweetgum (Liquidambar orientalis), and valerian (Valeriana wallichii) essential oils against pine wood nematode (Bursaphelenchus xylophilus).

PubMed

Kim, Junheon; Seo, Sun-Mi; Lee, Sang-Gil; Shin, Sang-Chul; Park, Il-Kwon

2008-08-27

Commercial essential oils from 28 plant species were tested for their nematicidal activities against the pine wood nematode, Bursaphelenchus xylophilus. Good nematicidal activity against B. xylophilus was achieved with essential oils of coriander (Coriandrum sativum), Oriental sweetgum (Liquidambar orientalis), and valerian (Valeriana wallichii). Analysis by gas chromatography-mass spectrometry led to the identification of 26, 11, and 4 major compounds from coriander (Coriandrum sativum), Oriental sweetgum (Liquidambar orientalis), and valerian (Valeriana wallichii) oils, respectively. Compounds from each plant essential oil were tested individually for their nematicidal activities against the pine wood nematode. Among the compounds, benzaldehyde, trans-cinnamyl alcohol, cis-asarone, octanal, nonanal, decanal, trans-2-decenal, undecanal, dodecanal, decanol, and trans-2-decen-1-ol showed strong nematicidal activity. The essential oils described herein merit further study as potential nematicides against the pine wood nematode.

Optimization of headspace solid phase micro-extraction of volatile compounds from papaya fruit assisted by GC-olfactometry.

PubMed

da Rocha, Renier Felinto Julião; da Silva Araújo, Ídila Maria; de Freitas, Sílvia Maria; Dos Santos Garruti, Deborah

2017-11-01

Optimization of the extraction conditions to investigate the volatile composition of papaya fruit involving headspace solid phase micro-extraction was carried out using multivariate strategies such as factorial design and response surface methodology. The performance of different combinations of time for reaching the equilibrium in the headspace and time for maximum extraction of volatiles was evaluated by GC-olfactometry of the extract (intensity of papaya characteristic aroma), number of peaks and total area in the chromatogram. Thirty-two compounds were identified by GC-MS under the optimized extraction conditions, the majority of which were aldehydes, both in number of compounds and area. Major compounds were δ-octalactone, β-citral, benzaldehyde, heptanal, benzyl isothiocyanate, isoamyl acetate, γ-octalactone, (E)-linalool oxide and benzyl alcohol. Seven aldehydes and two other compounds are reported for the first time in papaya's volatile profile.

Radicals and molecular products from the gas-phase pyrolysis of lignin model compounds. Cinnamyl alcohol

PubMed Central

Khachatryan, Lavrent; Xu, Meng-xia; Wu, Ang-jian; Pechagin, Mikhail; Asatryan, Rubik

2016-01-01

The experimental results on detection and identification of intermediate radicals and molecular products from gas-phase pyrolysis of cinnamyl alcohol (CnA), the simplest non-phenolic lignin model compound, over the temperature range of 400–800 °C are reported. The low temperature matrix isolation – electron paramagnetic resonance (LTMI-EPR) experiments along with the theoretical calculations, provided evidences on the generation of the intermediate carbon and oxygen centered as well as oxygen-linked, conjugated radicals. A mechanistic analysis is performed based on density functional theory to explain formation of the major products from CnA pyrolysis; cinnamaldehyde, indene, styrene, benzaldehyde, 1-propynyl benzene, and 2-propenyl benzene. The evaluated bond dissociation patterns and unimolecular decomposition pathways involve dehydrogenation, dehydration, 1,3-sigmatropic H-migration, 1,2-hydrogen shift, C—O and C—C bond cleavage processes. PMID:28344372

Comparative study of volatile components from male and female flower buds of Populus × tomentosa by HS-SPME-GC-MS.

PubMed

Xu, Liang; Liu, Haiping; Ma, Yucui; Wu, Cui; Li, Ruiqi; Chao, Zhimao

2018-06-13

The differences of volatile components in male (MFB) and female flower buds (FFB) of Populus × tomentosa were analysed and compared by HS-SPME with GC-MS for the first time. A total of 34 compounds were identified. Two clusters were clearly divided into male and female by hierarchical clustering analysis. Both the male and female flower buds showed methyl salicylate (22.83 and 24.09%, respectively) and 2-hydroxy-benzaldehyde (10.05 and 12.41%, respectively) as the main volatile constituents. The content of 2-cyclohexen-1-one, benzyl benzoate, and methyl benzoate in FFB was remarkably higher than in MFB. In contrast, the content of ethyl benzoate in MFB was greater than that in FFB. The phenomena showed the characteristic differences between MFB and FFB of P. × tomentosa, which enriched the basic studies on dioecious plant.

Reductive alkylation of ribosomes as a probe to the topography of ribosomal proteins*

PubMed Central

Moore, Graham; Crichton, Robert R.

1974-01-01

Escherichia coli ribosomes were treated with a number of different aldehydes of various sizes in the presence of NaBH4. After incorporation of either 3H or 14C, the ribosomal proteins were separated by two-dimensional polyacrylamide-gel electrophoresis and the extent of alkylation of the lysine residues in each protein was measured. The same pattern of alkylation was observed with the four reagents used, namely formaldehyde, acetone, benzaldehyde and 3,4,5-trimethoxybenzaldehyde. Every protein in 30S and 50S subunits was modified, although there was considerable variation in the degree of alkylation of individual proteins. A topographical classification of ribosomal proteins is presented, based on the degree of exposure of lysine residues. The data indicate that every protein of the ribosome has at least one lysine residue exposed at or near the surface of the ribonucleo-protein complex. PMID:4462744

Crystal structure of (E)-2-hy-droxy-4'-meth-oxy-aza-stilbene.

PubMed

Chantrapromma, Suchada; Kaewmanee, Narissara; Boonnak, Nawong; Chantrapromma, Kan; Ghabbour, Hazem A; Fun, Hoong-Kun

2015-06-01

The title aza-stilbene derivative, C14H13NO2 {systematic name: (E)-2-[(4-meth-oxy-benzyl-idene)amino]-phenol}, is a product of the condensation reaction between 4-meth-oxy-benzaldehyde and 2-amino-phenol. The mol-ecule adopts an E conformation with respect to the azomethine C=N bond and is almost planar, the dihedral angle between the two substituted benzene rings being 3.29 (4)°. The meth-oxy group is coplanar with the benzene ring to which it is attached, the Cmeth-yl-O-C-C torsion angle being -1.14 (12)°. There is an intra-molecular O-H⋯N hydrogen bond generating an S(5) ring motif. In the crystal, mol-ecules are linked via C-H⋯O hydrogen bonds, forming zigzag chains along [10-1]. The chains are linked via C-H⋯π inter-actions, forming a three-dimensional structure.

Molecular structure, vibrational spectral assignments (FT-IR and FT-RAMAN), NMR, NBO, HOMO-LUMO and NLO properties of O-methoxybenzaldehyde based on DFT calculations

NASA Astrophysics Data System (ADS)

Vennila, P.; Govindaraju, M.; Venkatesh, G.; Kamal, C.

2016-05-01

Fourier transform - Infra red (FT-IR) and Fourier transform - Raman (FT-Raman) spectroscopic techniques have been carried out to analyze O-methoxy benzaldehyde (OMB) molecule. The fundamental vibrational frequencies and intensity of vibrational bands were evaluated using density functional theory (DFT). The vibrational analysis of stable isomer of OMB has been carried out by FT-IR and FT-Raman in combination with theoretical method simultaneously. The first-order hyperpolarizability and the anisotropy polarizability invariant were computed by DFT method. The atomic charges, hardness, softness, ionization potential, electronegativity, HOMO-LUMO energies, and electrophilicity index have been calculated. The 13C and 1H Nuclear magnetic resonance (NMR) have also been obtained by GIAO method. Molecular electronic potential (MEP) has been calculated by the DFT calculation method. Electronic excitation energies, oscillator strength and excited states characteristics were computed by the closed-shell singlet calculation method.

Synthesis and antiviral bioactivities of 2-aryl- or 2-methyl-3-(substituted- benzalamino)-4(3H)-quinazolinone derivatives.

PubMed

Gao, Xingwen; Cai, Xuejian; Yan, Kai; Song, Baoan; Gao, Lili; Chen, Zhuo

2007-12-27

A simple and general method has been developed for the synthesis of various4(3H)-quinazolinone derivatives by the treatment of the appropriate 3-amino-2-aryl-4(3H)-quinazolinone with a substituted benzaldehyde in ethanol. The structures of the compoundswere characterized by elemental analysis, IR, (1)H-NMR and (13)C-NMR spectra. The title 2-aryl- or 2-methyl-3-(substituted-benzalamino)-4(3H)-quinazolinone compounds III-1~III-31 were found to possess moderate to good antiviral activity. Semi-quantitative PCR andReal Time PCR assays were used to ascertain the target of action of compound III-31against TMV. The studies suggest that III-31 possesses antiviral activity due to inductionof up-regulation of PR-1a and PR-5, thereby inhibiting virus proliferation and movementby enhancement of the activity of some defensive enzyme.

Synthesis, structural characterization, antimicrobial activities and theoretical investigations of some 4-(4-aminophenylsulfonyl) phenylimino) methyl)-4-(aryldiazenyl) phenol

NASA Astrophysics Data System (ADS)

Ghasemian, Motaleb; Kakanejadifard, Ali; Karami, Tahereh

2016-11-01

The azo-azomethine dyes with a different substitution have been designed from the reaction of 4,4‧-diaminodiphenyl sulfone with 2-hydroxy-5-(aryldiazenyl)benzaldehyde. The compounds have been characterized by elemental analysis, Mass, IR, UV-Vis, TGA-DTA and NMR spectroscopy. The solvatochromism behaviors, effects of substitution and pH on the electronic absorption spectra of dyes were evaluated. The in vitro antimicrobial activities were also screened for their potential for antibiotic activities by broth micro dilution method. Also, the optimum molecular geometries, molecular electrostatic potential (MEP), nucleus-independent chemical shift (NICS) and frontier molecular orbitals (FMO), vibrational spectra (IR) and electronic absorption (UV-Vis) spectra of the title compounds have been investigated with the help of DFT and TDDFT methods with 6-311 ++G(d,p) basis sets and PCM calculations. The results of the calculations show excellent agreement with the experimental value.

(E)-3-[3,4-Bis(meth-oxy-methoxy)phen-yl]-1-(7-hy-droxy-5-meth-oxy-2,2-dimethyl-chroman-8-yl)prop-2-en-1-one.

PubMed

Hashim, Nur Athirah; Ahmad, Farediah; Basar, Norazah; Awang, Khalijah; Ng, Seik Weng

2011-09-01

The reaction of 5,6-(2,2-dimethyl-chroman-yl)-2-hy-droxy-4-meth-oxy-acetophenone and 3,4-bis-(meth-oxy-meth-yloxy)benzaldehyde affords the intense orange title chalcone derivative, C(25)H(30)O(8). The two benzene rings are connected through a -C(=O)-CH=CH- (propenone) unit, which is in an E conformation; the ring with the hy-droxy substitutent is aligned at 19.5 (2)° with respect to this unit, whereas the ring with the meth-oxy-meth-yloxy substituent is aligned at 9.3 (3)°. The dihedral angle between the rings is 19.38 (10)°. The hy-droxy group engages in an intra-molecular O-H⋯O hydrogen bond with the carbonyl O atom of the propenone unit, generating an S(5) ring.

Characterization of oxidized coal surfaces: Quarterly report, January 1987-April 1987

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hercules, D.M.

1987-04-01

The work has focused on exploration of ambient temperature in-situ derivatization of aldehydes and ketones on carbon surfaces. 2,4-Dinitrophenylhydrazine, bisulfite, -ylium dichloro-iodate, and iminium perchlorate derivatizations were performed on a set of model aldehydes and ketones. Positive and negative ion laser mass spectra (LMS) of the 2,4-dinitrophenylhydrazine derivatives were obtained on zinic which is a common metal support used for LMS analysis. Although positive ion spectra were informative, negative ion spectra were more satisfactory as most compounds yielded molecular ion species in negative ion analysis. Spectra of selected preformed derivatives placed on charcoal and of benzaldehyde derivatized on charcoal weremore » also obtained. Molecular ion species that can be distinguished readily from carbon background ions were observed. Thus, the results established that in-situ derivatization followed by analysis is indeed possible. 3 refs., 8 figs.« less

Role of laccase from Coriolus versicolor MTCC-138 in selective oxidation of aromatic methyl group.

PubMed

Chaurasia, Pankaj Kumar; Singh, Sunil Kumar; Bharati, Shashi Lata

2014-01-01

Now a day, laccases are the most promising enzymes in the area of biotechnology and synthesis. One of the best applications of laccases is the selective oxidation of aromatic methyl group to aldehyde group. Such transformations are valuable because it is difficult to stop the reaction at aldehyde stage. Chemical methods used for such biotransformations areexpensive and give poor yields. But, the laccase-catalyzed biotransformations of such type are non-expensive and yield is excellent. Authors have used crude laccase obtained from the liquid culture growth medium of fungal strain Coriolus versicolor MTCC-138 for the biotransformations of toluene, 3-nitrotoluene, and 4-chlorotoluene to benzaldehyde, 3-nitrobenzaldehyde, and 4-chlorobenzaldehyde, respectively, instead of purified laccase because purification process requires much time and cost. This communication reports that crude laccase can also be used in the place of purified laccase as effective biocatalyst.

Design, synthesis, and spectroscopic study of some new flavones containing two azo linkages

NASA Astrophysics Data System (ADS)

Ayoob, Mzgin Mohammed; Hawaiz, Farouq Emam

2017-09-01

In the present study; 5-(4-chlorophenyl azo) -2-hydroxy acetophenone (1) was prepared by diazotization of 4-chloro aniline and its coupling reaction with 2-hydroxy acetophenone, then reacted with different azo benzyloxy benzaldehydes(3a-i) to give new synthesized 2-hydroxy chalcones(4a-i). The later compounds were subjected to oxidative cyclization by catalytic amount of I2 in DMSO affording the target molecules new flavones bearing two azo-linkages (5a-i). The structures of the newly synthesized compounds were identified on the bases of their FT-IR, 1H-NMR, 13C-NMR and DEPT-135 spectra. The synthesized Flavone derivatives were evaluated against two types of bacteria gram positive (Staphylococcus aurous) and gram negative (Pseudomonas aeruginosa). The results showed that most of the synthesized flavones are more sensitive against (G -ve) bacteria than (G +ve) bacteria.

Synthesis, crystal growth and studies on non-linear optical property of new chalcones

NASA Astrophysics Data System (ADS)

Sarojini, B. K.; Narayana, B.; Ashalatha, B. V.; Indira, J.; Lobo, K. G.

2006-09-01

The synthesis, crystal growth and non-linear optical (NLO) property of new chalcone derivatives are reported. 4-Propyloxy and 4-butoxy benzaldehydes were made to under go Claisen-Schmidt condensation with 4-methoxy, 4-nitro and 4-phenoxy acetophenones to form corresponding chalcones. The newly synthesized compounds were characterized by analytical and spectral data. The Second harmonic generation (SHG) efficiency of these compounds was measured by powder technique using Nd:YAG laser. Among tested compounds three chalcones showed NLO property. The chalcone 1-(4-methoxyphenyl)-3-(4-propyloxy phenyl)-2-propen-1-one exhibited SHG conversion efficiency 2.7 times that of urea. The bulk crystal of 1-(4-methoxyphenyl)-3-(4-butoxyphenyl)-2-propen-1-one (crystal size 65×28×15 mm 3) was grown by slow-evaporation technique from acetone. Microhardness of the crystal was tested by Vicker's microhardness method.

Pollen diversity and volatile variability of honey from Corsican Anthyllis hermanniae L. habitat.

PubMed

Yang, Yin; Battesti, Marie-José; Paolini, Julien; Costa, Jean

2014-12-01

Melissopalynological, physicochemical, and volatile analyses of 29 samples of Corsican 'summer maquis' honey were performed. The pollen spectrum was characterized by a wide diversity of nectariferous and/or polleniferous taxa. The most important were Anthyllis hermanniae and Rubus sp., associated with some endemic taxa. Castanea sativa was also determined in these honeys with a great variation. The volatile fraction was characterized by 37 compounds and dominated by phenolic aldehydes and linear acids. The major compounds were phenylacetaldehyde, benzaldehyde, and nonanoic acid. Statistical analysis of pollen and volatile data showed that 18 samples were characterized by a high abundance of phenylacetaldehyde, which might relate to the high amount of A. hermanniae and Rubus sp. Eleven other samples displayed a higher proportion of phenolic ketones and linear acids, which characterized the nectar contribution of C. sativa and Thymus herba-barona, respectively. Copyright © 2014 Verlag Helvetica Chimica Acta AG, Zürich.

Microkinetic Modeling of Benzyl Alcohol Oxidation on Carbon-Supported Palladium Nanoparticles

DOE Office of Scientific and Technical Information (OSTI.GOV)

Savara, Aditya; Rossetti, Ilenia; Chan-Thaw, Carine E.

Six products are formed from benzyl alcohol oxidation over Pd nanoparticles using O2 as the oxidant: benzaldehyde, toluene, benzyl ether, benzene, benzoic acid, and benzyl benzoate. Three experimental parameters were varied here: alcohol concentration, oxygen concentration, and temperature. Microkinetic modeling using a mechanism published recently with surface intermediates was able to produce all 18 trends observed experimentally with mostly quantitative agreement. Approximate analytical equations derived from the microkinetic model for isothermal conditions reproduced the isothermal trends and provided insight. The most important activation energies are Ea2=57.9 kJ mol₋1, Ea5=129 kJ mol₋1, and Ea6=175 kJ mol₋1, which correspond to alcohol dissociation,more » alkyl hydrogenation, and the reaction of alkyl species with alkoxy species. Upper limits for other activation energies were identified. The concepts of a sticking coefficient and steric factor in solution were applied.« less

Iridium-catalyzed Arene ortho-Silylation by Formal Hydroxyl-directed C-H Activation

PubMed Central

Simmons, Eric M.; Hartwig, John F.

2010-01-01

A strategy for the ortho-silylation of aryl ketone, benzaldehyde and benzyl alcohol derivatives has been developed in which a hydroxyl group formally serves as the directing element for Ir-catalyzed arene C-H bond activation. One-pot generation of a (hydrido)silyl ether from the carbonyl compound or alcohol is followed by dehydrogenative cyclization at 80–100 °C in the presence of norbornene as hydrogen acceptor and the combination of 1 mol % [Ir(cod)OMe]2 and 1,10-phenanthroline as catalyst to form benzoxasiloles. The synthetic utility of the benzoxasilole products is demonstrated by conversion to phenol or biaryl derivatives by Tamao-Fleming oxidation or Hiyama cross-coupling. Both of these transformations of the C-H silylation products exploit the Si-O bond in the system and proceed by activation of the silyl moiety with hydroxide, rather than fluoride. PMID:21077625

The Variation of Catalyst and Carrier Gas on Anisole Deoxygenation Reaction

NASA Astrophysics Data System (ADS)

Ariyani, D.; Dwi Nugrahaningtyas, Khoirina; Heraldy, E.

2018-03-01

This research aims to determine the best catalyst and carrier gas in anisole deoxygenation reaction. The reaction was carried out over a flow system with a variation of catalyst CoMo A (CoMo/USY reduction), CoMo B (CoMo/USY oxidation-reduction), and CoMo C (CoMo/ZAA oxidation-reduction). In addition, variation of carrier gas nitrogen and hydrogen was investigated. The result was analyzed using Gas Chromatography-Mass Spectroscopy (GC-MS). The deoxygenation anisole result showed that CoMo A catalyst with hydrogen as the carrier gas has the highest total product yield (50.72 %), intermediate product yield (38.49 % in phenol and 6.99 % in benzaldehyde), and deoxygenation yield (5.24 %). The CoMo C catalyst exhibited the most selective deoxygenation product. The nitrogen carrier gas with the CoMo C catalyst has the best selectivity of benzene product (93.92 %).

Synthesis and pharmacological investigation of 2-(4-dimethylaminophenyl)-3,5-disubstituted thiazolidin-4-ones as anticonvulsants.

PubMed

Senthilraja, Manavalan; Alagarsamy, Veerachamy

2012-10-01

A new series of 2-(4-dimethylaminophenyl)-3-substituted thiazolidin-4-one-5-yl-acetyl acetamides/benzamides were synthesized by the nucleophilic substitution of 3-substituted-2-(4-dimethylaminophenyl)-thiazolidin-4-one-5-yl-acetylchloride with acetamide and benzamide. The starting material 3-substituted-2-(4-dimethylaminophenyl)-thiazolidin-4-one-5-yl-acetylchloride was synthesized from 3-substituted-2-(4-dimethylaminophenyl)-thiazolidin-4-one-5-yl-acetic acid, which in turn was prepared by one-pot reaction of amino component, p-dimethylamino benzaldehyde and mercapto succinic acid. The title compounds were investigated for their anticonvulsant activities; among the test compounds, compound 2-(4-dimethylaminophenyl)-3-phenylamino-thiazolidine-4-one-5-yl-acetylbenzamide (14) emerged as the most active compound of the series and as moderately more potent than the reference standard diazepam. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Structural and biochemical analyses of YvgN and YtbE from Bacillus subtilis

PubMed Central

Lei, Jian; Zhou, Yan-Feng; Li, Lan-Fen; Su, Xiao-Dong

2009-01-01

Bacillus subtilis is one of the most studied gram-positive bacteria. In this work, YvgN and YtbE from B. subtilis, assigned as AKR5G1 and AKR5G2 of aldo-keto reductase (AKR) superfamily. AKR catalyzes the NADPH-dependent reduction of aldehyde or aldose substrates to alcohols. YvgN and YtbE were studied by crystallographic and enzymatic analyses. The apo structures of these proteins were determined by molecular replacement, and the structure of holoenzyme YvgN with NADPH was also solved, revealing the conformational changes upon cofactor binding. Our biochemical data suggest both YvgN and YtbE have preferential specificity for derivatives of benzaldehyde, such as nitryl or halogen group substitution at the 2 or 4 positions. These proteins also showed broad catalytic activity on many standard substrates of AKR, such as glyoxal, dihydroxyacetone, and DL-glyceraldehyde, suggesting a possible role in bacterial detoxification. PMID:19585557

Microwave-assisted synthesis and anti-YFV activity of 2,3-diaryl-1,3-thiazolidin-4-ones.

PubMed

Sriram, Dharmarajan; Yogeeswari, Perumal; Kumar, T G Ashok

2005-09-01

The purpose of this study was to prepare several 1,3-thaizolidin-4-ones bearing variously substituted diaryl ring at C-2 and N-3 positions and evaluate them for their anti-YFV activity. Several 1,3-thaizolidin-4-ones were prepared by reacting substituted benzaldehyde with equimolar amount of an appropriate substituted aromatic amine in the presence of an excess of mercaptoacetic acid in toluene utilizing microwave irradiation. The synthesized compounds were also evaluated for their inhibitory effects on the replication of YFV in green monkey kidney (Vero) cells (ATCC CCL81), by means of a cytopathic effect reduction assay. The compound DS1 emerged as the most potent anti-YFV agent with EC50 of 6.9 microM and CC50 more than 100 microM making it more potent than ribavirin. 2,3-diaryl-1,3-thiazolidin-4-ones possess anti-YFV potency.

When is an imine not an imine? Unusual reactivity of a series of Cu(II) imine-pyridine complexes and their exploitation for the Henry reaction.

PubMed

Cooper, Christine J; Jones, Matthew D; Brayshaw, Simon K; Sonnex, Benjamin; Russell, Mark L; Mahon, Mary F; Allan, David R

2011-04-14

In this paper we report the synthesis and solid-state structures for a series of pyridine based Cu(II) complexes and preliminary data for the asymmetric Henry reaction. Interestingly, the solid-state structures indicate the incorporation of an alcohol into one of the imine groups of the ligand, forming a rare α-amino ether group. The complexes have been studied via single crystal X-ray diffraction, EPR spectroscopy and mass spectrometry. Intriguingly, it has been observed that the alcohol only adds to one of the imine moieties. Density functional theory (DFT) calculations have also been employed to rationalise the observed structures. The Cu(II) complexes have been tested in the asymmetric Henry reaction (benzaldehyde + nitromethane or nitroethane) with ee's up to 84% being achieved as well as high conversions and modest diastereoselectivities. © The Royal Society of Chemistry 2011

Chemical analysis applied to the radiation sterilization of solid ketoprofen

NASA Astrophysics Data System (ADS)

Colak, S.; Maquille, A.; Tilquin, B.

2006-01-01

The aim of this work is to investigate the feasibility of radiation sterilization of ketoprofen from a chemical point of view. Although irradiated ketoprofen has already been studied in the literature [Katusin-Razem et al., Radiat. Phys. Chem. 73 111-116 (2005)], new results, on the basis of electron spin resonance (ESR) measurements and the use of hyphenated techniques (GC-MS and LC-MS), are obtained. The ESR spectra of irradiated ketoprofen consists of four unresolved resonance peaks and the mean G-value of ketoprofen is found to be 4 +/- 0.9 nmoles/J, which is very small. HPLC-UV analyses indicate that no significant loss of ketoprofen is detected after irradiation. LC-MS-MS analyses show that the structures of the non-volatile final products are similar to ketoprofen. Benzaldehyde is detected in the irradiated samples after dynamic-extraction GC-MS. The analyses show that ketoprofen is radioresistant and therefore might be radiosterilized.

Ethylenediamine diacetate (EDDA) mediated synthesis of aurones under ultrasound: their evaluation as inhibitors of SIRT1.

PubMed

Manjulatha, Khanapur; Srinivas, S; Mulakayala, Naveen; Rambabu, D; Prabhakar, M; Arunasree, Kalle M; Alvala, Mallika; Basaveswara Rao, M V; Pal, Manojit

2012-10-01

An improved synthesis of functionalized aurones has been accomplished via the reaction of benzofuran-3(2H)-one with a range of benzaldehydes in the presence of a mild base EDDA under ultrasound. A number of aurones were synthesized (within 5-30min) and the molecular structure of a representative compound determined by single crystal X-ray diffraction study confirmed Z-geometry of the C-C double bond present within the molecule. Some of the compounds synthesized have shown SIRT1 inhibiting as well as anti proliferative properties against two cancer cell lines in vitro. Compound 3a [(Z)-2-(5-bromo-2-hydroxybenzylidene) benzofuran-3(2H)-one] was identified as a potent inhibitor of SIRT1 (IC(50)=1μM) which showed a dose dependent increase in the acetylation of p53 resulting in induction of apoptosis. Copyright © 2012 Elsevier Ltd. All rights reserved.

Ultrasonic evidence of hydrophobic interactions. Effect of ultrasound on benzoin condensation and some other reactions in aqueous ethanol.

PubMed

Tuulmets, Ants; Hagu, Hannes; Salmar, Siim; Cravotto, Giancarlo; Järv, Jaak

2007-03-29

The kinetics of KCN-catalyzed benzoin condensation of benzaldehyde in water and ethanol-water binary mixtures was investigated both under ultrasound at 22 kHz and without sonication. Thermodynamic activation parameters were calculated from kinetic data obtained at 35, 50, and 65 degrees C. Evidence that ultrasound can retard reactions is reported and hence a direct proof that sonochemical processes occur in the bulk solution. Former results and literature data for ester hydrolyses and tert-butyl chloride solvolysis are involved in the discussion. A quantitative relationship between sonication effects and the hydrophobicity of reagents is presented for the first time. Ultrasound affects hydrophobic interactions with the solvent, which are not manifested in conventional kinetics. When it suppresses the stabilization of the encounter complexes between reagents, sonication hinders the reaction but accelerates it when it perturbs the hydrophobic stabilization of the ground state of a reagent.

Odour intensity learning in fruit flies

PubMed Central

Yarali, Ayse; Ehser, Sabrina; Hapil, Fatma Zehra; Huang, Ju; Gerber, Bertram

2009-01-01

Animals' behaviour towards odours depends on both odour quality and odour intensity. While neuronal coding of odour quality is fairly well studied, how odour intensity is treated by olfactory systems is less clear. Here we study odour intensity processing at the behavioural level, using the fruit fly Drosophila melanogaster. We trained flies by pairing a MEDIUM intensity of an odour with electric shock, and then, at a following test phase, measured flies' conditioned avoidance of either this previously trained MEDIUM intensity or a LOWer or a HIGHer intensity. With respect to 3-octanol, n-amylacetate and 4-methylcyclohexanol, we found that conditioned avoidance is strongest when training and test intensities match, speaking for intensity-specific memories. With respect to a fourth odour, benzaldehyde, on the other hand, we found no such intensity specificity. These results form the basis for further studies of odour intensity processing at the behavioural, neuronal and molecular level. PMID:19586944

Reaction Acceleration in Thin Films with Continuous Product Deposition for Organic Synthesis.

PubMed

Wei, Zhenwei; Wleklinski, Michael; Ferreira, Christina; Cooks, R Graham

2017-08-01

Thin film formats are used to study the Claisen-Schmidt base-catalyzed condensation of 6-hydroxy-1-indanone with substituted benzaldehydes and to compare the reaction acceleration relative to the bulk. Relative acceleration factors initially exceeded 10 3 and were on the order of 10 2 at steady state, although the confined volume reaction was not electrostatically driven. Substituent effects were muted compared to those in the corresponding bulk and microdroplet reactions and it is concluded that the rate-limiting step at steady state is reagent transport to the interface. Conditions were found that allowed product deposition from the thin film to occur continuously as the reaction mixture was added and as the solvent evaporated. Yields of 74 % and production rates of 98 mg h -1 were reached in a very simple experimental system that could be multiplexed to greater scales. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Microkinetic Modeling of Benzyl Alcohol Oxidation on Carbon-Supported Palladium Nanoparticles

DOE PAGES

Savara, Aditya; Rossetti, Ilenia; Chan-Thaw, Carine E.; ...

2016-07-14

Six products are formed from benzyl alcohol oxidation over Pd nanoparticles using O2 as the oxidant: benzaldehyde, toluene, benzyl ether, benzene, benzoic acid, and benzyl benzoate. Three experimental parameters were varied here: alcohol concentration, oxygen concentration, and temperature. Microkinetic modeling using a mechanism published recently with surface intermediates was able to produce all 18 trends observed experimentally with mostly quantitative agreement. Approximate analytical equations derived from the microkinetic model for isothermal conditions reproduced the isothermal trends and provided insight. The most important activation energies are Ea2=57.9 kJ mol₋1, Ea5=129 kJ mol₋1, and Ea6=175 kJ mol₋1, which correspond to alcohol dissociation,more » alkyl hydrogenation, and the reaction of alkyl species with alkoxy species. Upper limits for other activation energies were identified. The concepts of a sticking coefficient and steric factor in solution were applied.« less

Characterization of Aronia melanocarpa volatiles by headspace-solid-phase microextraction (HS-SPME), simultaneous distillation/extraction (SDE), and gas chromatography-olfactometry (GC-O) methods.

PubMed

Kraujalytė, Vilma; Leitner, Erich; Venskutonis, Petras Rimantas

2013-05-22

The profiles of volatile constituents of berry fruit of two Aronia melanocarpa genotypes were evaluated by headspace-solid-phase microextraction (HS-SPME), simultaneous distillation and extraction (SDE), and gas chromatography-olfactometry (GC-O). In total, 74 volatile compounds were identified in chokeberry juice, 3-penten-2-one, 3,9-epoxy-p-menth-1-ene, and benzaldehyde being the most abundant constituents; however, their percentage concentrations were remarkably different in the HS-SPME and SDE profiles. Twenty two aroma-active compounds were detected and characterized by the trained panelists in HS-SPME using GC-O detection frequency analysis. Olfactometry revealed that ethyl-2-methyl butanoate, ethyl-3-methyl butanoate, ethyl decanoate ("fruity" aroma notes), nonanal ("green" notes), unidentified compound possessing "moldy" odor, and some other volatiles may be very important constituents in formation of chokeberry aroma of both analyzed plant cultivars.

pH-responsive self-healing injectable hydrogel based on N-carboxyethyl chitosan for hepatocellular carcinoma therapy.

PubMed

Qu, Jin; Zhao, Xin; Ma, Peter X; Guo, Baolin

2017-08-01

Injectable hydrogels with pH-responsiveness and self-healing ability have great potential for anti-cancer drug delivery. Herein, we developed a series of polysaccharide-based self-healing hydrogels with pH-sensitivity as drug delivery vehicles for hepatocellular carcinoma therapy. The hydrogels were prepared by using N-carboxyethyl chitosan (CEC) synthesized via Michael reaction in aqueous solution and dibenzaldehyde-terminated poly(ethylene glycol) (PEGDA). Doxorubicin (Dox), as a model of water-soluble small molecule anti-cancer drug was encapsulated into the hydrogel in situ. Self-healing behavior of the hydrogels was investigated at microscopic and macroscopic levels, and the hydrogels showed rapid self-healing performance without any external stimulus owing to the dynamic covalent Schiff-base linkage between amine groups from CEC and benzaldehyde groups from PEGDA. The chemical structures, rheological property, in vitro gel degradation, morphology, gelation time and in vitro Dox release behavior from the hydrogels were characterized. Injectability was verified by in vitro injection and in vivo subcutaneous injection in a rat. pH-responsive behavior was verified by in vitro Dox release from hydrogels in PBS solutions with different pH values. Furthermore, the activity of Dox released from hydrogel matrix was evaluated by employing human hepatocellular liver carcinoma (HepG2). Cytotoxicity test of the hydrogels using L929 cells confirmed their good cytocompatibility. Together, these pH-responsive self-healing injectable hydrogels are excellent candidates as drug delivery vehicles for liver cancer treatment. STATEMENT OF SIGNIFICANCE: pH-responsive drug delivery system could release drug efficiently in targeted acid environment and minimalize the amount of drug release in normal physiological environment. pH-sensitive injectable hydrogels as smart anti-cancer drug delivery carriers show great potential application for cancer therapy. The hydrogels with self-healing property could prolong their lifetime during implantation and provide the advantage of minimally invasive surgery and high drug-loading ratio. This work reported the design of a series of pH-responsive self-healing injectable hydrogels based on N-carboxyethyl chitosan synthesized in aqueous solution and dibenzaldehyde-terminated poly(ethylene glycol) via a green approach, and demonstrated their potential as intelligent delivery vehicle of doxorubicin for hepatocellular carcinoma therapy via the pH-responsive nature of dynamic Schiff base. Copyright © 2017 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Thermochemical data and additivity group values for ten species of o-xylene low-temperature oxidation mechanism.

PubMed

Canneaux, Sébastien; Vandeputte, Romain; Hammaecher, Catherine; Louis, Florent; Ribaucour, Marc

2012-01-12

o-Xylene could be a good candidate to represent the family of aromatic hydrocarbons in a surrogate fuel. This study uses computational chemistry to calculate standard enthalpies of formation at 298 K, Δ(f)H°(298 K), standard entropies at 298 K, S°(298 K), and standard heat capacities C(p)°(T) over the temperature range 300 K to 1500 K for ten target species present in the low-temperature oxidation mechanism of o-xylene: o-xylene (1), 2-methylbenzyl radical (2), 2-methylbenzylperoxy radical (3), 2-methylbenzyl hydroperoxide (4), 2-(hydroperoxymethyl)benzyl radical (5), 2-(hydroperoxymethyl)benzaldehyde (6), 1-ethyl-2-methylbenzene (7), 2,3-dimethylphenol (8), 2-hydroxybenzaldehyde (9), and 3-hydroxybenzaldehyde (10). Δ(f)H°(298 K) values are weighted averages across the values calculated using five isodesmic reactions and five composite calculation methods: CBS-QB3, G3B3, G3MP2, G3, and G4. The uncertainty in Δ(f)H°(298 K) is also evaluated. S°(298 K) and C(p)°(T) values are calculated at B3LYP/6-311G(d,p) level of theory from molecular properties and statistical thermodynamics through evaluation of translational, rotational, vibrational, and electronic partition functions. S°(298 K) and C(p)°(300 K) values are evaluated using the rigid-rotor-harmonic-oscillator model. C(p)°(T) values at T ≥ 400 K are calculated by treating separately internal rotation contributions and translational, external rotational, vibrational, and electronic contributions. The thermochemical properties of six target species are used to develop six new additivity groups taking into account the interaction between two substituents in ortho (ORT/CH2OOH/ME, ORT/ET/ME, ORT/CHO/OH, ORT/CHO/CH2OOH) or meta (MET/CHO/OH) positions, and the interaction between three substituents (ME/ME/OH123) located one beside the other (positions numbered 1, 2, 3) for two- or three-substituted benzenic species. Two other additivity groups are also developed using the thermochemical properties of benzenic species taken from the literature: the C/CB/H2/OO and the CB/CO groups. These groups extend the capacities of the group additivity method to deal with substituted benzenic species.

Volatile components of vine leaves from two Portuguese grape varieties (Vitis vinifera L.), Touriga Nacional and Tinta Roriz, analysed by solid-phase microextraction.

PubMed

Fernandes, Bruno; Correia, Ana C; Cosme, Fernanda; Nunes, Fernando M; Jordão, António M

2015-01-01

The purpose of this work was to study the volatile composition of vine leaves and vine leaf infusion prepared from vine leaves collected at 30 and 60 days after grape harvest of two Vitis vinifera L. species. Eighteen volatile compounds were identified by gas chromatography-mass spectrometry in vine leaves and in vine leaf infusions. It was observed that the volatile compounds present in vine leaves are dependent on the time of harvest, with benzaldehyde being the major volatile present in vine leaves collected at 30 days after harvesting. There are significant differences in the volatile composition of the leaves from the two grape cultivars, especially in the sample collected at 60 days after grape harvest. This is not reflected in the volatile composition of the vine leaf infusion made from this two cultivars, the more important being the harvesting date for the volatile profile of vine leaf infusion than the vine leaves grape cultivar.

Skin diseases in workers at a perfume factory.

PubMed

Schubert, Hans-Jürgen

2006-08-01

The aim of this study is to find out the causes of skin diseases in one-third of the staff of a perfume factory, in which 10 different perfume sprays were being manufactured. Site inspection, dermatological examination and patch testing of all 26 persons at risk with 4 perfume oils and 30 ingredients of them. The results showed 6 bottlers were found suffering from allergic contact dermatitis, 2 from irritant contact dermatitis, 12 workers showed different strong reactions to various fragrances. The main causes of allergic contact dermatitis were 2 perfume oils (12 cases) and their ingredients geraniol (12 cases), benzaldehyde(9), cinnamic aldehyde (6), linalool, neroli oil, terpenes of lemon oil and orange oil (4 each). Nobody was tested positive to balsam of Peru. Job changes for office workers, packers or printers to other rooms, where they had no longer contact with fragrances, led to a settling. To conclude, automation and replacement of glass bottles by cartridges from non-fragile materials and using gloves may minimize the risk.

Hierarchical Porous Interlocked Polymeric Microcapsules: Sulfonic Acid Functionalization as Acid Catalysts

NASA Astrophysics Data System (ADS)

Wang, Xiaomei; Gu, Jinyan; Tian, Lei; Zhang, Xu

2017-03-01

Owing to their unique structural and surface properties, mesoporous microspheres are widely applied in the catalytic field. Generally, increasing the surface area of the specific active phase of the catalyst is a good method, which can achieve a higher catalytic activity through the fabrication of the corresponding catalytic microspheres with the smaller size and hollow structure. However, one of the major challenges in the use of hollow microspheres (microcapsules) as catalysts is their chemical and structural stability. Herein, the grape-like hypercrosslinked polystyrene hierarchical porous interlocked microcapsule (HPIM-HCL-PS) is fabricated by SiO2 colloidal crystals templates, whose structure is the combination of open mouthed structure, mesoporous nanostructure and interlocked architecture. Numerous microcapsules assembling together and forming the roughly grape-like microcapsule aggregates can enhance the structural stability and recyclability of these microcapsules. After undergoing the sulfonation, the sulfonated HPIM-HCL-PS is served as recyclable acid catalyst for condensation reaction between benzaldehyde and ethylene glycol (TOF = 793 h-1), moreover, exhibits superior activity, selectivity and recyclability.

Probing the importance of the hemilabile site of bis(phosphine) monoxide ligands in the copper-catalyzed addition of diethylzinc to N-phosphinoylimines: discovery of new effective chiral ligands.

PubMed

Bonnaventure, Isabelle; Charette, André B

2008-08-15

The hemilabile ligand Me-DuPHOS(O) 2 has proven to be a successful ligand for the copper-catalyzed addition of diethylzinc to N-phosphinoylimines. The corresponding alpha-chiral amines were obtained in high yields (80-98%) and enantiomeric ratios (19.0:1 to 99.0:1 er). Furthermore, this Cu* 2 catalytic system has been shown to be effective in the addition of diethylzinc to nitroalkenes and in the reduction of beta,beta-disubstituted vinyl phenyl sulfones. This paper describes a general structure/selectivity study in which the three ligand subunits (chiral phospholane-linker-labile coordinating group (Z)) are systematically modified and tested in the copper-catalyzed addition of diethylzinc to the N-phosphinoylimine 1 derived from benzaldehyde. This study led to the discovery of a new class of effective chiral ligands that combine a chiral phospholane unit and an achiral phosphine oxide.

Synthetic phenolic antioxidants, including butylated hydroxytoluene (BHT), in resin-based dental sealants

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Wei; Kannan, Pranav; Xue, Jingchuan

Resin-based dental sealants (also referred to as pit-and-fissure sealants) have been studied for their contribution to bisphenol A (BPA) exposure in children. Nevertheless, little attention has been paid to the occurrence of other potentially toxic chemicals in dental sealants. In this study, the occurrence of six synthetic phenolic antioxidants (SPAs), including 2,6-di-tert-butyl-4-hydroxytoluene (BHT), 2,6-di-tert-butyl-4-(hydroxyethyl)phenol (BHT-OH), 3,5-di-tert-butyl-4-hydroxy-benzaldehyde (BHT-CHO), 2,6-di-tert-butylcyclohexa-2,5-diene-1,4-dione (BHT-Q), 3,5-di-tert-butyl-4-hydroxybenzoic acid (BHT-COOH) and 2-tert-butyl-4-methoxyphenol (BHA), was examined in 63 dental sealant products purchased from the U.S. market. BHT was found in all dental sealants at median and maximum concentrations of 56.8 and 1020 µg/g, respectively. The metabolites of BHT andmore » BHA were detected in 39–67% of samples, at concentration ranges of« less

Isolation, identification and antioxidant activity of bound phenolic compounds present in rice bran.

PubMed

Wang, Wei; Guo, Jia; Zhang, Junnan; Peng, Jie; Liu, Tianxing; Xin, Zhihong

2015-03-15

The bound phenolic compounds in rice bran were released and extracted with ethyl acetate based on alkaline digestion. An investigation of the chemical constituents of EtOAc extract has led to the isolation of a new compound, para-hydroxy methyl benzoate glucoside (8), together with nine known compounds, cycloeucalenol cis-ferulate (1), cycloeucalenol trans-ferulate (2), trans-ferulic acid (3), trans-ferulic acid methyl ester (4), cis-ferulic acid (5), cis-ferulic acid methyl ester (6), methyl caffeate (7), vanillic aldehyde (9) and para-hydroxy benzaldehyde (10). The structures of these compounds were determined using a combination of spectroscopic methods and chemical analysis. Among the compounds isolated, compound 3, 5 and 7 exhibited strong DPPH and ABTS(+) radical scavenging activities, followed by compounds 4 and 6. Compound 1 and 2 showed potent DPPH and ABTS(+) radical scavenging activities, compound 8 displayed moderate antioxidant activity against ABTS(+) radical, whereas compound 9 and 10 showed weak antioxidant activity. Copyright © 2014 Elsevier Ltd. All rights reserved.

Hydroxyapatite catalyzed aldol condensation: Synthesis, spectral linearity, antimicrobial and insect antifeedant activities of some 2,5-dimethyl-3-furyl chalcones

NASA Astrophysics Data System (ADS)

Subramanian, M.; Vanangamudi, G.; Thirunarayanan, G.

2013-06-01

A series of 2,5-dimethyl-3-furyl chalcones [2E-1-(2,5-dimethyl-3-furyl)-3-(substituted phenyl)-2-propen-1-ones] have been synthesized by Hydrotalcite catalyzed aldol condensation between 3-acetyl-2,5-dimethylfuron and substituted benzaldehydes. Yields of chalcones are more than 80%. These chalcones were characterized by their physical constants and spectral data. The group frequencies of infrared ν(cm-1) of CO s-cis and s-trans, CH in-plane and out of plane, CHdbnd CH out of plane, lbond2 Cdbnd Crbond2 out of plane modes, NMR chemical shifts δ(ppm) of Hα, Hβ, CO, Cα and Cβ of these chalcones were correlated with Hammett substituent constants, F and R parameters using single and multi-regression analyses. From the results of statistical analyses, the effects of substituents on the group frequencies are explained. Antibacterial, antifungal and insect antifeedant activities of these chalcones have been studied.

Mechanistic Investigation of Molybdate-Catalysed Transfer Hydrodeoxygenation.

PubMed

Larsen, Daniel B; Petersen, Allan R; Dethlefsen, Johannes R; Teshome, Ayele; Fristrup, Peter

2016-11-07

The molybdate-catalysed transfer hydrodeoxygenation (HDO) of benzyl alcohol to toluene driven by oxidation of the solvent isopropyl alcohol to acetone has been investigated by using a combination of experimental and computational methods. A Hammett study that compared the relative rates for the transfer HDO of five para-substituted benzylic alcohols was carried out. Density-functional theory (DFT) calculations suggest a transition state with significant loss of aromaticity contributes to the lack of linearity observed in the Hammett study. The transfer HDO could also be carried out in neat PhCH 2 OH at 175 °C. Under these conditions, PhCH 2 OH underwent disproportionation to yield benzaldehyde, toluene, and significant amounts of bibenzyl. Isotopic-labelling experiments (using PhCH 2 OD and PhCD 2 OH) showed that incorporation of deuterium into the resultant toluene originated from the α position of benzyl alcohol, which is in line with the mechanism suggested by the DFT study. © 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

1,3,4-Thiadiazole derivatives of R-(+)-limonene benzaldehyde-thiosemicarbazones cause death in Trypanosoma cruzi through oxidative stress.

PubMed

Martins, Solange C; Lazarin-Bidóia, Danielle; Desoti, Vânia C; Falzirolli, Hugo; da Silva, Cleuza C; Ueda-Nakamura, Tania; Silva, Sueli de O; Nakamura, Celso V

2016-12-01

This work evaluated the in vitro and in vivo activity of TDZ 2 on Trypanosoma cruzi amastigotes and determined the possible mechanism of action of this compound on T. cruzi death. TDZ 2 inhibited T. cruzi proliferation in vitro and had low haemolytic potential. It also induced morphological and ultrastructural alterations. We observed a reduction of cell volume, the depolarization of the mitochondrial membrane, an increase in ROS production, lipoperoxidation of the cell membrane, lipid bodies formation and production of nitric oxide, a decrease in reduced thiols levels and, presence of autophagic vacuoles. The in vivo study found a reduction of parasitemia in animals treated with TDZ 2 alone or combined with benznidazole. Altogether, the alterations induced by TDZ 2 point to an oxidative stress condition that lead to T. cruzi cell death. Copyright © 2016 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

Yellowing reaction in encapsulant of photovoltaic modules

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shigekuni, T.; Kumano, M.

1997-12-31

To clarify the mechanism of the yellowing reaction in encapsulant used for photovoltaic (PV) modules, a low molecular weight substance in EVA (Ethylene vinyl acetate) under accelerated weathering test (Dew cycle test, 1000 hours) with yellow change and virgin EVA were extracted with methanol. Extracts were chemically analyzed by GCIR (Gas Chromatography Infrared-Ray spectroscopic analysis), GC-AED (Gas Chromatography Atomic Emission Detector), and FDMS (Field Desorption Mass Spectroscopy). The conditions of this accelerated test were based on JIS-K9117. The analysis results showed that 2,6-di-t-butyl-4-methyl phenol of antioxidant and 2-hydroxy-4-octoxy-benzophenone of UV absorbent were consumed after the weathering test and that 3,5-di-t-butyl-4-hydroxy-benzaldehydemore » having yellow color was newly produced. A mechanism of the yellowing reaction in encapsulant was presented here that 2,6-di-t-N-O radical from Bis-2,2,6,6-tetramethyl-4-piperidinyl sebacate to produce 3,5 di-t-butyl-4-hydroxy benzaldehyde.« less

Crystal structure of benzyl (E)-2-(3,4-di-meth-oxy-benzyl-idene)hydrazine-1-carbodi-thio-ate.

PubMed

Tan, Yew-Fung; Break, Mohammed Khaled Bin; Tahir, M Ibrahim M; Khoo, Teng-Jin

2015-02-01

The title compound, C17H18N2O2S2, synthesized via a condensation reaction between S-benzyl di-thio-carbazate and 3,4-di-meth-oxy-benzaldehyde, crystallized with two independent mol-ecules (A and B) in the asymmetric unit. Both mol-ecules have an L-shape but differ in the orientation of the benzyl ring with respect to the 3,4-di-meth-oxy-benzyl-idine ring, this dihedral angle is 65.59 (8)° in mol-ecule A and 73.10 (8)° in mol-ecule B. In the crystal, the A and B mol-ecules are linked via pairs of N-H⋯S hydrogen bonds, forming dimers with an R 2 (2)(8) ring motif. The dimers are linked via pairs of C-H⋯O hydrogen bonds, giving inversion dimers of dimers. These units are linked by C-H⋯π inter-actions, forming ribbons propagating in the [100] direction.

Comparative study of glass tube and mist chamber sampling techniques for the analysis of gaseous carbonyl compounds

NASA Astrophysics Data System (ADS)

François, Stéphanie; Perraud, Véronique; Pflieger, Maryline; Monod, Anne; Wortham, Henri

In this work, glass tube and mist chamber sampling techniques using 2,4-dinitrophenylhydrazine as derivative agent for the analysis of gaseous carbonyl compounds are compared. Trapping efficiencies of formaldehyde, acetaldehyde, propionaldehyde, acetone, acrolein, glyoxal, crotonaldehyde, benzaldehyde, butyraldehyde and valeraldehyde are experimentally determined using a gas-phase generator. In addition to generalise our results to all atmospheric gaseous compounds and derivative agents, theoretical trapping efficiencies and enrichment factors are expressed taking into account mechanisms involved in the two kinds of traps. Theoretical and experimental results show that, as expected, the trapping efficiencies of the glass tube depend mainly on solubility of compounds. The results provide new information and better understanding of phenomena occurring in the mist chamber and the ability of this sampler to concentrate the samples. Hence, the mist chamber is the more convenient sampling method when the trapping is associated to a fast derivatisation of the compounds and the glass tube technique must be used to trap atmospheric compounds without simultaneous derivatisation.

pH and Glucose Dual-Responsive Injectable Hydrogels with Insulin and Fibroblasts as Bioactive Dressings for Diabetic Wound Healing.

PubMed

Zhao, Lingling; Niu, Lijing; Liang, Hongze; Tan, Hui; Liu, Chaozong; Zhu, Feiyan

2017-11-01

pH and glucose dual-responsive injectable hydrogels were prepared through the cross-linking of Schiff's base and phenylboronate ester using phenylboronic-modified chitosan, poly(vinyl alcohol) and benzaldehyde-capped poly(ethylene glycol). Protein drugs and live cells could be incorporated into the hydrogels during the in situ cross-linking, displaying sustained and pH/glucose-triggered drug release from the hydrogels and cell viability and proliferation in the three-dimensional hydrogel matrix as well. Hence, the hydrogels with insulin and fibroblasts were considered as bioactive dressings for diabetic wound healing. A streptozotocin-induced diabetic rat model was used to evaluate the efficacy of hydrogel dressings in wound repair. The results revealed that the incorporation of insulin and L929 in the hydrogels could promote neovascularization and collagen deposition and enhance the wound-healing process of diabetic wounds. Thus, the drug- and cell-loaded hydrogels have promising potential in wound healing as a medicated system for various therapeutic proteins and live cells.

Synthesis and β-glucuronidase inhibitory activity of 2-arylquinazolin-4(3H)-ones.

PubMed

Khan, Khalid Mohammed; Saad, Syed Muhammad; Shaikh, Nimra Naveed; Hussain, Shafqat; Fakhri, Muhammad Imran; Perveen, Shahnaz; Taha, Muhammad; Choudhary, Muhammad Iqbal

2014-07-01

2-Arylquinazolin-4(3H)-ones 1-25 were synthesized by reacting anthranilamide with various benzaldehydes using CuCl2·2H2O as a catalyst in ethanol under reflux. Synthetic 2-arylquinazolin-4(3H)-ones 1-25 were evaluated for their β-glucuronidase inhibitory potential. A trend of inhibition IC50 against the enzyme in the range of 0.6-198.2μM, was observed and compared with the standard d-saccharic acid 1,4-lactone (IC50=45.75±2.16μM). Compounds 13, 19, 4, 12, 14, 22, 23, 25, 15, 8, 17, 11, 21, 1, 3, 18, 9, 2, and 24 with the IC50 values within the range of 0.6-44.0μM, indicated that the compounds have superior activity than the standard. The compounds showed no cytotoxic effects against PC-3 cells. A structure-activity relationship is established. Copyright © 2014 Elsevier Ltd. All rights reserved.

Circuit mechanisms encoding odors and driving aging-associated behavioral declines in Caenorhabditis elegans.

PubMed

Leinwand, Sarah G; Yang, Claire J; Bazopoulou, Daphne; Chronis, Nikos; Srinivasan, Jagan; Chalasani, Sreekanth H

2015-09-22

Chemosensory neurons extract information about chemical cues from the environment. How is the activity in these sensory neurons transformed into behavior? Using Caenorhabditis elegans, we map a novel sensory neuron circuit motif that encodes odor concentration. Primary neurons, AWC(ON) and AWA, directly detect the food odor benzaldehyde (BZ) and release insulin-like peptides and acetylcholine, respectively, which are required for odor-evoked responses in secondary neurons, ASEL and AWB. Consistently, both primary and secondary neurons are required for BZ attraction. Unexpectedly, this combinatorial code is altered in aged animals: odor-evoked activity in secondary, but not primary, olfactory neurons is reduced. Moreover, experimental manipulations increasing neurotransmission from primary neurons rescues aging-associated neuronal deficits. Finally, we correlate the odor responsiveness of aged animals with their lifespan. Together, these results show how odors are encoded by primary and secondary neurons and suggest reduced neurotransmission as a novel mechanism driving aging-associated sensory neural activity and behavioral declines.

Synthesis of novel fluorinated chalcones derived from 4‧-morpholinoacetophenone and their antiproliferative effects

NASA Astrophysics Data System (ADS)

Kurşun Aktar, Bedriye Seda; Oruç-Emre, Emine Elçin; Demirtaş, Ibrahim; Yaglioglu, Ayse Sahin; Guler, Caglar; Adem, Sevki; Karaküçük Iyidoğan, Ayşegül

2017-12-01

The fluorinated chalcones were synthesized by Claisen-Schmidt condensation between 4‧-morpholineacetophenone and various fluorinated benzaldehydes in the presence of NaOH in methanol. The synthesized compounds [1-7] were evaluated their antiproliferative activity against HeLa and C6 cell lines. Among them, compounds 4 and 5 were determined to have anticancer activity against HeLa cells line (IC50 values of 7.74 and 6.10 μg/mL, respectively). The anticancer activity results were shown that compounds 3, and 6 had inhibitory against C6 cells (IC50 values of 12.80 and 4.16 μg/mL, respectively). The compounds 1 and 2 had high antiproliferative activity with non-cytotoxicity. All of the new compounds, except for compound 4 showed inhibition against the human isozyme hCA I with IC50 in the range of 0.5-1,16 mM. Pyruvate kinase M2 (PKM2) was effectively inhibited by compound 4 with IC50 = 26 μM.

Conformational Aspects of the O-acetylation of C-tetra(phenyl)calixpyrogallol[4]arene.

PubMed

Casas-Hinestroza, José Luis; Maldonado, Mauricio

2018-05-20

Reaction between pyrogallol and benzaldehyde results in a conformational mixture of C- tetra(phenyl)pyrogallol[4]arene (crown and chair). The conformer mixture was separated using crystallization procedures and the structures were determined using FTIR, ¹H-NMR, and 13 C-NMR. O -acetylation of C- tetra(phenyl)pyrogallol[4]arene (chair) with acetic anhydride, in pyridine results in the formation of dodecaacetyl-tetra(phenyl)pyrogallol[4]arene. The structure was determined using ¹H-NMR and 13 C-NMR finding that the product maintains the conformation of the starting conformer. On the other hand, the O -acetylation reaction of C- tetra(phenyl)pirogallol[4]arene (crown) under same conditions proceeded efficiently, and its structure was determined using ¹H-NMR and 13 C-NMR. Dynamic ¹H-NMR of acetylated pyrogallolarene was studied by means of variable temperature in DMSO- d ₆ solution, and it revealed that two conformers are formed in the solution. Boat conformations for acetylated pyrogallolarene showed a slow interconversion at room temperature.

Chemical Analysis of Dietary Constituents in Rosa roxburghii and Rosa sterilis Fruits.

PubMed

Liu, Meng-Hua; Zhang, Qi; Zhang, Yuan-He; Lu, Xian-Yuan; Fu, Wei-Ming; He, Jing-Yu

2016-09-09

Both Rosa roxburghii and R. sterilis, belonging to the Rosaceae, are endemic species in Guizhou Province, China. The fruits of these two species are mixed-used as functional food in the region. Aiming to elucidate the phytochemical characteristics of R. roxburghii and R. sterilis fruits, the essential oils and constituents in a methanol extract have been analyzed and compared by GC-MS and UFLC/Q-TOF-MS, respectively. As a result, a total of 135 volatile compounds were identified by GC-MS and 91 components were different between R. roxburghii and R. sterilis fruits; a total of 59 compounds in methanol extracts were identified by UFLC/Q-TOF-MS, including 13 organic acids, 12 flavonoids, 11 triterpenes, nine amino acids, five phenylpropanoid derivatives, four condensed tannins, two stilbenes, two benzaldehyde derivatives and one benzoic acid derivative; and nine characteristic compounds were found between R. roxburghii and R. sterilis fruits. This systematic study plays an important role for R. roxburghii and R. sterilis fruits in the product development.

Lateral cis-1,3,5,7-tetraazadecalin podands and their complexes: synthesis, structure, and strong binding with Pb(II) and other heavy metal ions.

PubMed

Reany, Ofer; Fuchs, Benzion

2013-02-18

The chemistry and complexation behavior of diaminal podands based on cis-1,3,5,7-tetraazadecalin (cis-TAD) were elaborated, reassessed, and extended. The synthesis of 2,6-bis(hydroxymethylene)-cis-TAD (9) and 2,6-bis(α,α'-dimethyl-β- hydroxyethyl)-cis-TAD (10) as well as of suitably substituted 2,6-diaryl-cis-TAD podands is laid out. For the latter, the effect of electron donating or withdrawing substituents on the benzaldehyde reagents was examined while 9 and 10 were probed and showed considerable propensity for heavy metal-ion chelation. The [Cd(II)·(9)] and [Pb(II)·(9)] complexes stood out indeed, and their structure and properties show a particularly interesting 5-amino-1,3-diazane chelation type and strong ligand-ion binding mode, with intramolecular donor exchange in solution, all strongly influenced by the anomeric effect in the ligand.

Carbonyl atmospheric reaction products of aromatic hydrocarbons in ambient air

NASA Astrophysics Data System (ADS)

Obermeyer, Genevieve; Aschmann, Sara M.; Atkinson, Roger; Arey, Janet

To convert gaseous carbonyls to oximes during sampling, an XAD-4 resin denuder system pre-coated with O-(2,3,4,5,6-pentafluorobenzyl)hydroxylamine and followed by analysis with methane positive chemical ionization gas chromatography/mass spectrometry was used to measure carbonyls in ambient air samples in Riverside, CA. In conjunction with similar analyses of environmental chamber OH radical-initiated reactions of o- and p-xylene, 1,2,4-trimethylbenzene, ethylbenzene, 4-hydroxy-2-butanone and 1,4-butanediol, we identified benzaldehyde, o-, m- and p-tolualdehyde and acetophenone and the dicarbonyls glyoxal, methylglyoxal, biacetyl, ethylglyoxal, 1,4-butenedial, 3-hexene-2,5-dione, 3-oxo-butanal, 1,4-butanedial and malonaldehyde in the ambient air samples. As discussed, these carbonyls and dicarbonyls can be formed from the OH radical-initiated reactions of aromatic hydrocarbons and other volatile organic compounds emitted into the atmosphere, and we conclude that in situ atmospheric formation is a major source of these carbonyls in our Riverside, CA, ambient air samples.

[Mechanism and performance of styrene oxidation by O3/H2O2].

PubMed

He, Jue-Cong; Huang, Qian-Ru; Ye, Qi-Hong; Luo, Yu-Wei; Zhang, Zai-Li; Fan, Qing-Juan; Wei, Zai-Shan

2013-10-01

It can produce a large number of free radicals in O3/H2O2, system, ozone and free radical coupling oxidation can improve the styrene removal efficiency. Styrene oxidation by O3/H2O2 was investigated. Ozone dosage, residence time, H2o2 volume fraction, spray density and molar ratio of O3/C8H8 on styrene removal were evaluated. The experimental results showed that styrene removal efficiency achieved 85.7%. The optimal residence time, H2O2, volume fraction, spray density and O3/C8H8 molar ratio were 20. 6 s, 10% , 1.72 m3.(m2.h)-1 and 0.46, respectively. The gas-phase degradation intermediate products were benzaldehyde(C6H5CHO) and benzoic acid (C6H5 COOH) , which were identified by means of gas chromatography-mass spectrometry(GC-MS). The degradation mechanism of styrene is presented.

Molecular System for the Division of Self-Propelled Oil Droplets by Component Feeding.

PubMed

Banno, Taisuke; Toyota, Taro

2015-06-30

Unique dynamics using inanimate molecular assemblies have drawn a great amount of attention for demonstrating prebiomimetic molecular systems. For the construction of an organized logic combining two fundamental dynamics of life, we demonstrate here a molecular system that exhibits both division and self-propelled motion using oil droplets. The key molecule of this molecular system is a novel cationic surfactant containing a five-membered acetal moiety, and the molecular system can feed the self-propelled oil droplet composed of a benzaldehyde derivative and an alkanol. The division dynamics of the self-propelled oil droplets were observed through the hydrolysis of the cationic surfactant in bulk solution. The mechanism of the current dynamics is argued to be based on the supply of "fresh" oil components in the moving oil droplets, which is induced by the Marangoni instability. We consider this molecular system to be a prototype of self-reproducing inanimate molecular assembly exhibiting self-propelled motion.

Synthesis, characterization and biological studies of copper(II) complexes with 2-aminobenzimidazole derivatives

NASA Astrophysics Data System (ADS)

Joseph, J.; Suman, A.; Nagashri, K.; Joseyphus, R. Selwin; Balakrishnan, Nisha

2017-06-01

Novel series of four copper(II) complexes with 2-aminobenzimidazole derivatives (obtained from the Knoevenagel condensate of acetylacetone (obtained from acetylacetone and halogen substituted benzaldehydes) and 2-aminobenzimidazole) were synthesized. They were structurally characterized using elemental analysis, molar conductance, FAB mass, FT- IR, 1H &13C-NMR, UV-Vis., and EPR techniques. On the basis of analytical and spectral studies, the distorted square planar geometry was assigned for all the complexes. The antibacterial screening of the ligands and their copper complexes indicated that all the complexes showed higher anti microbial activities than the free ligands. Superoxide dismutase and antioxidant activities of the copper complexes have also been performed. In the electrochemical technique, the shift in ΔEp, E1/2 and Ipc values were explored for the interaction of the complexes with CT-DNA. During the electrolysis process, the present ligand system stabilizes unusual oxidation state of copper in the complexes. It is believed that the copper complexes with curcumin analogs may enhance chemotherapeutic behavior.

Ligand-tailored single-site silica supported titanium catalysts: Synthesis, characterization and towards cyanosilylation reaction

NASA Astrophysics Data System (ADS)

Xu, Wei; Li, Yani; Yu, Bo; Yang, Jindou; Zhang, Ying; Chen, Xi; Zhang, Guofang; Gao, Ziwei

2015-01-01

A successive anchoring of Ti(NMe2)4, cyclopentadiene and a O-donor ligand, 1-hydroxyethylbenzene (PEA), 1,1‧-bi-2-naphthol (Binol) or 2,3-dihydroxybutanedioic acid diethyl ester (Tartrate), on silica was conducted by SOMC strategy in moderate conditions. The silica, monitored by in-situ Fourier transform infrared spectroscopy (in-situ FT-IR), was pretreated at different temperatures (200, 500 and 800 °C). The ligand tailored silica-supported titanium complexes were characterized by in-situ FT-IR, 13C CP MAS-NMR, X-ray photoelectron spectroscopy (XPS), X-ray absorption near edge structure (XANES) and elemental analysis in detail, verifying that the surface titanium species are single sited. The catalytic activity of the ligand tailored single-site silica supported titanium complexes was evaluated by a cyanosilylation of benzaldehyde. The results showed that the catalytic activity is dependent strongly on the dehydroxylation temperatures of silica and the configuration of the ligands.

Measurement of the dipole moments of excited states and photochemical transients by microwave dielectric absorption

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fessenden, R.W.; Carton, P.M.; Shimamori, H.

1982-09-16

Time-resolved changes in microwave dielectric absorption have been used to study transients formed by laser flash photolysis. Details of the method and apparatus are given. Applications both to the measurements of the dipole moments of transients and to decay kinetics are given. The dipole moments of the lowest triplet states of a number of aromatic compounds (mostly ketones) have been measured in benzene solution at room temperature. States of n..pi..* character generally possess smaller dipole moments than the corresponding ground states while states of ..pi pi..* character (for example, fluorenone) have larger values than the ground state. The triplets ofmore » 4-(dimethylamino)benzaldehyde and 4,4'-bis(dimethylamino)benzophenone have rather high values of dipole moment (10.5 and 8.4 D, respectively) showing their charge-transfer character. The triplet state of benzil was found to have zero or near-zero dipole moment, thus confirming that the triplet state is of a transstructure. 7 figures, 1 table.« less

Tandem catalysis by palladium nanoclusters encapsulated in metal–organic frameworks

DOE PAGES

Li, Xinle; Guo, Zhiyong; Xiao, Chaoxian; ...

2014-08-25

A bifunctional Zr-MOF catalyst containing palladium nanoclusters (NCs) has been developed. The formation of Pd NCs was confirmed by transmission electron microscopy (TEM) and extended X-ray absorption fine structure (EXAFS). Combining the oxidation activity of Pd NCs and the acetalization activity of the Lewis acid sites in UiO-66-NH 2, this catalyst (Pd@UiO-66-NH 2) exhibits excellent catalytic activity and selectivity in a one-pot tandem oxidation-acetalization reaction. This catalyst shows 99.9% selectivity to benzaldehyde ethylene acetal in the tandem reaction of benzyl alcohol and ethylene glycol at 99.9% conversion of benzyl alcohol. We also examined various substituted benzyl alcohols and found thatmore » alcohols with electron-donating groups showed better conversion and selectivity compared to those with electron-withdrawing groups. As a result, we further proved that there was no leaching of active catalytic species during the reaction and the catalyst can be recycled at least five times without significant deactivation.« less

Physicochemical and flavor characteristics of flavoring agent from mungbean protein hydrolyzed by bromelain.

PubMed

Sonklin, Chanikan; Laohakunjit, Natta; Kerdchoechuen, Orapin

2011-08-10

Enzymatic bromelain mungbean meal protein hydrolysate (eb-MPH) was produced from mungbean meal protein isolate (MPI). Enzymatic bromelain, with a known protease activity of 98,652 (unit/g), was used at concentrations of 0, 2, 6, 10, 14 and 18% (w/w) and with hydrolysis times of 0.5, 3, 6, 12, and 24 h. The pH and temperature were controlled at 6.0 and 50 °C, respectively. It was found that the best treatment combination for eb-MPH production by response surface methodology (RSM) was 18% bromelain and a hydrolysis time of 3 h, resulting in the greatest degree of hydrolysis (% DH) and percent yield, with values of 61.04 and 45.63%, respectively. Results also showed that the phenylalanine, tyrosine and leucine contents of the optimally produced eb-MPH were 20.88, 14.50 and 10.93%, respectively. Twelve volatile compounds were identified using gas chromatography mass spectrometry in eb-MPH; benzaldehyde, 2-pentylfuran and furfural were the predominant odorants.

Circuit mechanisms encoding odors and driving aging-associated behavioral declines in Caenorhabditis elegans

PubMed Central

Leinwand, Sarah G; Yang, Claire J; Bazopoulou, Daphne; Chronis, Nikos; Srinivasan, Jagan; Chalasani, Sreekanth H

2015-01-01

Chemosensory neurons extract information about chemical cues from the environment. How is the activity in these sensory neurons transformed into behavior? Using Caenorhabditis elegans, we map a novel sensory neuron circuit motif that encodes odor concentration. Primary neurons, AWCON and AWA, directly detect the food odor benzaldehyde (BZ) and release insulin-like peptides and acetylcholine, respectively, which are required for odor-evoked responses in secondary neurons, ASEL and AWB. Consistently, both primary and secondary neurons are required for BZ attraction. Unexpectedly, this combinatorial code is altered in aged animals: odor-evoked activity in secondary, but not primary, olfactory neurons is reduced. Moreover, experimental manipulations increasing neurotransmission from primary neurons rescues aging-associated neuronal deficits. Finally, we correlate the odor responsiveness of aged animals with their lifespan. Together, these results show how odors are encoded by primary and secondary neurons and suggest reduced neurotransmission as a novel mechanism driving aging-associated sensory neural activity and behavioral declines. DOI: http://dx.doi.org/10.7554/eLife.10181.001 PMID:26394000

Dynamic covalent chemistry of bisimines at the solid/liquid interface monitored by scanning tunnelling microscopy.

PubMed

Ciesielski, Artur; El Garah, Mohamed; Haar, Sébastien; Kovaříček, Petr; Lehn, Jean-Marie; Samorì, Paolo

2014-11-01

Dynamic covalent chemistry relies on the formation of reversible covalent bonds under thermodynamic control to generate dynamic combinatorial libraries. It provides access to numerous types of complex functional architectures, and thereby targets several technologically relevant applications, such as in drug discovery, (bio)sensing and dynamic materials. In liquid media it was proved that by taking advantage of the reversible nature of the bond formation it is possible to combine the error-correction capacity of supramolecular chemistry with the robustness of covalent bonding to generate adaptive systems. Here we show that double imine formation between 4-(hexadecyloxy)benzaldehyde and different α,ω-diamines as well as reversible bistransimination reactions can be achieved at the solid/liquid interface, as monitored on the submolecular scale by in situ scanning tunnelling microscopy imaging. Our modular approach enables the structurally controlled reversible incorporation of various molecular components to form sophisticated covalent architectures, which opens up perspectives towards responsive multicomponent two-dimensional materials and devices.

Concentration and trend of 9,10-phenanthrenequinone in airborne particulates collected in Nagasaki city, Japan.

PubMed

Kishikawa, Naoya; Nakao, Maiko; Ohba, Yoshihito; Nakashima, Kenichiro; Kuroda, Naotaka

2006-07-01

9,10-Phenanthrenequinone (PQ), one of the components of atmospheric pollutants, has potent harmful effects on human health. PQ in airborne particulates collected in Nagasaki city was determined by HPLC with fluorescence derivatization. PQ extracted from airborne particulates using methanol was derivatized with benzaldehyde in the presence of ammonium acetate to give a fluorescent compound. The average concentration (mean+/-SD, n=52) of PQ found in airborne particulates collected from July 1997 to June 1998 was 0.287+/-0.128 ng m-3. Concentrations of PQ in winter were higher than those in summer. In a weekly variation study, PQ concentrations were higher during weekdays and lower at weekend. The levels of PQ were obviously correlated with those of phenanthrene (PH) that is considered as a parent compound of PQ. This observation suggested that PQ was emitted into the atmosphere from the same source as PH, or PQ was converted from PH in the atmosphere.

MICROBIAL METABOLISM OF AROMATIC COMPOUNDS I.

PubMed Central

Tabak, Henry H.; Chambers, Cecil W.; Kabler, Paul W.

1964-01-01

Tabak, Henry H. (Robert A. Taft Sanitary Engineering Center, Cincinnati, Ohio), Cecil W. Chambers, and Paul W. Kabler. Microbial metabolism of aromatic carbon compounds. I. Decomposition of phenolic compounds and aromatic hydrocarbons by phenol-adapted bacteria. J. Bacteriol. 87:910–919. 1964.—Bacteria from soil and related environments were selected or adapted to metabolize phenol, hydroxy phenols, nitrophenols, chlorophenols, methylphenols, alkylphenols, and arylphenols when cultured in mineral salts media with the specific substrate as the sole source of carbon. A phenol-adapted culture (substrate-induced enzyme synthesis proven) was challenged in respirometric tests with 104 related compounds; probable significant oxidative activity occurred with 65. Dihydric phenols were generally oxidized; trihydric phenols were not. Cresols and dimethylphenols were oxidized; adding a chloro group increased resistance. Benzoic and hydroxybenzoic acids were oxidized; sulfonated, methoxylated, nitro, and chlorobenzoic acids were not; m-toluic acid was utilized but not the o- and p-isomers. Benzaldehyde and p-hydroxybenzaldehyde were oxidized. In general, nitro- and chloro-substituted compounds and the benzenes were difficult to oxidize. PMID:14137630

Functionalized SBA-15 supported nickel (II)–oxime–imine catalysts for liquid phase oxidation of olefins under solvent-free conditions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Paul, Luna; Banerjee, Biplab; Bhaumik, Asim, E-mail: msab@iacs.res.in

2016-05-15

A new oxime–imine functionalized highly ordered mesoporous SBA-15 (SBA-15-NH{sub 2}-DAMO) has been synthesized via post-synthesis functionalization of SBA-15 with 3-aminopropyl-triethoxysilane followed by the Schiff base condensation with diacetylmonooxime, which was further reacted with Ni(ClO{sub 4}){sub 2} to yield the functionalized nickel catalyst SBA-15-NH{sub 2}-DAMO-Ni. All the synthesized materials were thoroughly characterized using different characterization techniques. It was found that SBA-15-NH{sub 2}-DAMO-Ni catalyzes the one-pot oxidation of olefins like styrene, cyclohexene, cyclooctene, 1-hexene and 1-octene to the corresponding benzaldehyde, cyclohexene-1-ol and cyclooctene-oxide, respectively under solvent-free conditions by using tert-butylhydroperoxide as oxidant. - Graphical abstract: A new well characterized oxime–imine functionalized highlymore » ordered mesoporous SBA-15-NH{sub 2}-DAMO-Ni complex catalyzes the one-pot oxidation of olefins under solvent free mild conditions.« less

Origin of low-molecular mass aldehydes as disinfection by-products in beverages.

PubMed

Serrano, María; Gallego, Mercedes; Silva, Manuel

2017-09-01

A novel, simple and automatic method based on static headspace-gas chromatography-mass spectrometry has been developed to determine 10 low-molecular mass aldehydes that can be found in beverages, coming from the treated water used in their production. These aldehydes are the most frequently found in treated water as water disinfection by-products, so they can be used as indicators of the addition of treated water to beverages. The study covered a large number of fruit juices and soft drinks. The presence of the whole array of analytes is related to the contact with treated water during beverage production, mainly by the addition of treated water as ingredient. In particular, propionaldehyde, valeraldehyde and benzaldehyde can be used as indicators of the addition of treated water in these kinds of beverages. Among the ten aldehydes, only formaldehyde and acetaldehyde are naturally present in all kinds of fruit, and their concentrations are related to stage of the ripening of the fruit.

Evaluation of pre-rigor injection of beef with proteases on cooked meat volatile profile after 1 day and 21 days post-mortem storage.

PubMed

Ma, Q L; Hamid, N; Bekhit, A E D; Robertson, J; Law, T F

2012-12-01

This research was carried out to determine the effects of pre-rigor injection of beef semimembranosus muscle with nine proteases from plant and microbial sources, on the volatile profile of cooked beef after 1 day and 21 days post-mortem (PM) storage using Solid-phase microextraction gas chromatography mass spectrometry analysis. A total of 23 aldehydes, 5 ketones, 3 furans, 8 nitrogen and sulphur compounds, 4 alkanes, 7 alcohols and 6 terpenes were detected. Eleven volatile compounds characteristic of ginger flavour were detected in zingibain-treated meat. Benzaldehyde significantly increased (p<0.05) only in kiwifruit juice (KJ), fungal 31 protease and Asparagus protease (ASP) treated samples from 1 day to 21 days PM storage. A significant increase (p<0.05) in 3-methylbutanal was observed in KJ, bacterial and fungal protease treated samples at 21 days PM storage. Treatments with bromelain, papain, ASP, actinidin, and KJ (except KJ 21 days) proteases resulted in flavour profiles closer to that of the control beef sample. Copyright © 2012 Elsevier Ltd. All rights reserved.

The benzylperoxyl radical as a source of hydroxyl and phenyl radicals.

PubMed

Sander, Wolfram; Roy, Saonli; Bravo-Rodriguez, Kenny; Grote, Dirk; Sanchez-Garcia, Elsa

2014-09-26

The benzyl radical (1) is a key intermediate in the combustion and tropospheric oxidation of toluene. Because of its relevance, the reaction of 1 with molecular oxygen was investigated by matrix-isolation IR and EPR spectroscopy as well as computational methods. The primary reaction product of 1 and O2 is the benzylperoxyl radical (2), which exists in several conformers that can easily interconvert even at cryogenic temperatures. Photolysis of radical 2 at 365 nm results in a formal [1,3]-H migration and subsequent cleavage of the O-O bond to produce a hydrogen-bonded complex between the hydroxyl radical and benzaldehyde (4). Prolonged photolysis produces the benzoyl radical (5) and water, which finally yield the phenyl radical (7), CO, and H2O. Thus, via a sequence of exothermic reactions 1 is transformed into radicals of even higher reactivity, such as OH and 7. Our results have implications for the development of models for the highly complicated process of combustion of aromatic compounds. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Effective Recovery of Vanadium from Oil Refinery Waste into Vanadium-Based Metal-Organic Frameworks.

PubMed

Zhan, Guowu; Ng, Wei Cheng; Lin, Wenlin Yvonne; Koh, Shin Nuo; Wang, Chi-Hwa

2018-03-06

Carbon black waste, an oil refinery waste, contains a high concentration of vanadium(V) leftover from the processing of crude oil. For the sake of environmental sustainability, it is therefore of interest to recover the vanadium as useful products instead of disposing of it. In this work, V was recovered in the form of vanadium-based metal-organic frameworks (V-MOFs) via a novel pathway by using the leaching solution of carbon black waste instead of commercially available vanadium chemicals. Two different types of V-MOFs with high levels of crystallinity and phase purity were fabricated in very high yields (>98%) based on a coordination modulation method. The V-MOFs exhibited well-defined and controlled shapes such as nanofibers (length: > 10 μm) and nanorods (length: ∼270 nm). Furthermore, the V-MOFs showed high catalytic activities for the oxidation of benzyl alcohol to benzaldehyde, indicating the strong potential of the waste-derived V-MOFs in catalysis applications. Overall, our work offers a green synthesis pathway for the preparation of V-MOFs by using heavy metals of industrial waste as the metal source.

A study of interferences in ozone UV and chemiluminescence monitors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hudgens, E.E.; Kleindienst, T.E.; McElroy, F.F.

A study was conducted to examine interferences and other measurement anomalies in chemiluminescence and ultraviolet ozone monitors. Previous results had show that there was a positive deviation in the chemiluminescence monitors and no direct interference with ultraviolet monitors due to the presence of water at non-condensing concentrations. The present study continues this effort, examining both potential positive and negative effects of moisture and other interferences on these monitors. Aromatic compounds and their oxidation products could potentially show a positive interference with ultraviolet monitors, and test measurements were made with aromatics such as toluene, benzaldehyde, and nitrotoluene to determine their possiblemore » retention in the ozone scrubber and their absorption in the cell as a function of the humidity. A detailed examination of the scrubbers used in ultraviolet ozone monitors has also been undertaken. Ozone scrubbers that have shown anomalous behavior in the field have been studied in various reduced-efficacy modes under controlled laboratory conditions. Longer term tests of unused scrubbers for possible ozone breakthrough under exposure to various simulated field conditions were initiated.« less

Emission of floral volatiles from Mahonia japonica (Berberidaceae).

PubMed

Picone, Joanne M; MacTavish, Hazel S; Clery, Robin A

2002-07-01

Flowering Mahonia japonica plants were subjected to controlled environments and the floral volatiles emitted from whole racemes (laterals) were trapped by Porapak Q adsorbent and analysed by GC-FID. An experiment with photoperiods of 6 and 9 h at constant temperature (10+/-1 degrees C) demonstrated that photoperiod was the stimulus for enhanced emission of most volatiles. Small quantitative differences in emitted fragrance composition were observed between light and dark periods and between plants acclimatised to different photoperiods. Maximum rates of emission occurred in the middle of the light period; aromatic compounds (benzaldehyde, benzyl alcohol and indole) displayed a more rapid increase and subsequent decline compared with monoterpenes (cis- and trans-ocimene and linalool). When the photoperiod was extended from 6 to 9 h, maximum rates of emission continued throughout the additional 3 h. Total emission (microg/h) of volatiles was 2-fold greater in the day-time (DT) (39.7 microg/h) compared with the night-time (NT) (19.8 microgg/h) under a 6 h photoperiod and was not significantly different from total emission under a 9 h photoperiod.

Characterization of volatile profile from ten different varieties of Chinese jujubes by HS-SPME/GC-MS coupled with E-nose.

PubMed

Chen, Qinqin; Song, Jianxin; Bi, Jinfeng; Meng, Xianjun; Wu, Xinye

2018-03-01

Volatile profile of ten different varieties of fresh jujubes was characterized by HS-SPME/GC-MS (headspace solid phase micro-extraction combined with gas chromatography-mass spectrometry) and E-nose (electronic nose). GC-MS results showed that a total of 51 aroma compounds were identified in jujubes, hexanoic acid, hexanal, (E)-2-hexenal, (Z)-2-heptenal, benzaldehyde and (E)-2-nonenal were the main aroma components with contributions that over 70%. Differentiation of jujube varieties was conducted by cluster analysis of GC-MS data and principal component analysis & linear discriminant analysis of E-nose data. Both results showed that jujubes could be mainly divided into two groups: group A (JZ, PDDZ, JSXZ and LWZZ) and group B (BZ, YZ, MZ, XZ and DZ). There were significant differences in contents of alcohols, acids and aromatic compounds between group A and B. GC-MS coupled with E-nose could be a fast and accurate method to identify the general flavor difference in different varieties of jujubes. Copyright © 2017 Elsevier Ltd. All rights reserved.

Chemometric evaluation of the volatile profile of probiotic melon and probiotic cashew juice.

PubMed

de Godoy Alves Filho, Elenilson; Rodrigues, Tigressa Helena Soares; Fernandes, Fabiano André Narciso; Pereira, Ana Lucia Fernandes; Narain, Narendra; de Brito, Edy Sousa; Rodrigues, Sueli

2017-09-01

The aim of this study was to evaluate the influence of the lactic acid fermentation on volatile compounds of melon and cashew apple juices. The effect of the fermentation processing on the volatile profile of probiotic juices was assessed by HS-SPME/GC-MS coupled to chemometrics with 67.9% and 81.0% of the variance in the first principal component for melon and cashew juices, respectively. The Lactobacillus casei fermentation imparted a reduction of ethyl butanoate, ethyl-2-methylbutirate, and ethyl hexanoate for melon juice; and of ethyl acetate, ethyl-2-methyl butanoate, ethyl crotonate, ethyl isovalerate, benzaldehyde, and ethyl hexanoate for cashew juice. Measurements of the stability of these compounds and the formation of the component 3-methyl-2-butenyl in melon juice may be used as a volatile marker to follow the juice fermentation. These findings suggested that even though it is not a dairy product the lactic acid fermentation of fruits developed a volatile profile combining the fruit and lactic acid fermentation volatiles with mildly formation or degradation of aroma compounds. Copyright © 2017 Elsevier Ltd. All rights reserved.

Pyrrole-coupled salicylimine-based fluorescence "turn on" probe for highly selective recognition of Zn²⁺ ions in mixed aqueous media: Application in living cell imaging.

PubMed

Bhosale, Jitendra; Fegade, Umesh; Bondhopadhyay, Banashree; Kaur, Simanpreet; Singh, Narinder; Basu, Anupam; Dabur, Rajesh; Bendre, Ratnamala; Kuwar, Anil

2015-06-01

Cation sensing behaviour of a pyrrole-based derivative (2-hydroxyl 3 methyl 6 isopropyl benzaldehyde}-3,4-dimethyl-1H-pyrrole-2-carbohydrazide (receptor 3) has been explored and is found to be selective towards Zn(2+) over a variety of tested cations. The receptor 3 has shown high selectivity and sensitivity towards Zn(2+) over the other alkali, alkaline earth and transition metal ions. In the presence of Zn(2+), absorption band of receptor 3 has shown the red shift. The sensing behaviour has been suggested to continue via enhancement process which has further been supported by UV-vis absorption and theoretical density functional theory (DFT) calculations indicating the formation of a 1:1 complex between the pyrrole based receptor 3 and Zn(2+). The present work is presenting a highly selective dual channel colorimetric sensor for zinc with great sensitivity. The developed sensor was successfully applied to image intracellular Zn(2+) in living cells. Copyright © 2015 John Wiley & Sons, Ltd.

Enantioselective Synthesis of Various Cyanohydrins Using Covalently Immobilized Preparations of Hydroxynitrile Lyase from Prunus dulcis.

PubMed

Alagöz, Dilek; Tükel, S Seyhan; Yildirim, Deniz

2015-11-01

The carrier-based and carrier-free (cross-linked enzyme aggregate) covalent immobilizations of Prunus dulcis hydroxynitrile lyase were investigated. The immobilized preparations were tested for enantioselective carbon-carbon bond formation activity in the biphasic medium. Of the tested preparations, only cross-linked enzyme aggregate of P. dulcis hydroxynitrile lyase (PdHNL-CLEA) achieved the synthesis of (R)-mandelonitrile with 93% yield and 99% enantiopurity. PdHNL-CLEA was also used in the synthesis of various (R)-cyanohydrins from corresponding aldehydes/ketones and hydrocyanic acid. When 4-methoxybenzaldehyde, 4-methyl benzaldehyde, and 4-hydroxybenzaldehyde were used as substrates, the yield-enantiomeric excess of corresponding (R)-cyanohydrins were obtained as 95-95, 85-79, and 2-25%, respectively, after 96 h at pH 4.0 and 5 °C. For acetophenone, 4-fluoroacetophenone, 4-chloroacetophenone, 4-bromoacetophenone, and 4-iodoacetophenone, the yield-enantiomeric excess of corresponding (R)-cyanohydrins were 1-99, 20-84, 11-95, 5-99, and 3-24%, respectively at the same conditions. The results demonstrate PdHNL-CLEA can be effectively used in the synthesis of (R)-mandelonitrile.

HS-SPME GC/MS characterization of volatiles in raw and dry-roasted almonds (Prunus dulcis).

PubMed

Xiao, Lu; Lee, Jihyun; Zhang, Gong; Ebeler, Susan E; Wickramasinghe, Niramani; Seiber, James; Mitchell, Alyson E

2014-05-15

A robust HS-SPME and GC/MS method was developed for analyzing the composition of volatiles in raw and dry-roasted almonds. Almonds were analyzed directly as ground almonds extracted at room temperature. In total, 58 volatiles were identified in raw and roasted almonds. Straight chain aldehydes and alcohols demonstrated significant but minimal increases, while the levels of branch-chain aldehydes, alcohols, heterocyclic and sulfur containing compounds increased significantly (500-fold) in response to roasting (p<0.05). Benzaldehyde decreased from 2934.6±272.5 ng/g (raw almonds) to 315.8±70.0 ng/g (averaged across the roasting treatments evaluated i.e. 28, 33 and 38 min at 138 °C) after roasting. Pyrazines were detected in only the roasted almonds, with the exception of 2,5-dimethylpyrazine, which was also found in raw almonds. The concentration of most alcohols increased in the roasted samples with the exception of 2-methyl-1-propanol, 3-methyl-1-butanol and 2-phenylethyl alcohol, which decreased 68%, 80%, and 86%, respectively. Copyright © 2013 Elsevier Ltd. All rights reserved.

Volatiles from a rare Acer spp. honey sample from Croatia.

PubMed

Jerković, Igor; Marijanović, Zvonimir; Malenica-Staver, Mladenka; Lusić, Drazen

2010-06-24

A rare sample of maple (Acer spp.) honey from Croatia was analysed. Ultrasonic solvent extraction (USE) using: 1) pentane, 2) diethyl ether, 3) a mixture of pentane and diethyl ether (1:2 v/v) and 4) dichloromethane as solvents was applied. All the extracts were analysed by GC and GC/MS. The most representative extracts were 3) and 4). Syringaldehyde was the most striking compound, being dominant in the extracts 2), 3) and 4) with percentages 34.5%, 33.1% and 35.9%, respectively. In comparison to USE results of other single Croatian tree honey samples (Robinia pseudoacacia L. nectar honey, Salix spp. nectar and honeydew honeys, Quercus frainetto Ten. honeydew as well as Abies alba Mill. and Picea abies L. honeydew) and literature data the presence of syringaldehyde, previously identified in maple sap and syrup, can be pointed out as a distinct characteristic of the Acer spp. honey sample. Headspace solid-phase microextraction (HS-SPME) combined with GC and GC/MS identified benzaldehyde (16.5%), trans-linalool oxide (20.5%) and 2-phenylethanol (14.9%) as the major compounds that are common in different honey headspace compositions.

Use of Tetragenococcus halophilus as a starter culture for flavor improvement in fish sauce fermentation.

PubMed

Udomsil, Natteewan; Rodtong, Sureelak; Choi, Yeung Joon; Hua, Yanglin; Yongsawatdigul, Jirawat

2011-08-10

The potential of Tetragenococcus halophilus as a starter culture for flavor improvement in fish sauce fermentation was elucidated. Four strains of T. halophilus isolated from fish sauce mashes were inoculated to anchovy mixed with 25% NaCl with an approximate cell count of 10(6) CFU/mL. The α-amino content of 6-month-old fish sauce samples inoculated with T. halophilus was 780-784 mM. The addition of T. halophilus MRC10-1-3 and T. halophilus MCD10-5-10 resulted in a reduction of histamine (P < 0.05). Fish sauce inoculated with T. halophilus showed high contents of total amino acids with predominantly high glutamic acid. Major volatile compounds in fish sauce were 2-methylpropanal, 2-methylbutanal, 3-methylbutanal, and benzaldehyde. T. halophilus-inoculated fish sauce samples demonstrated the ability to reduce dimethyl disulfide, a compound contributing to a fecal note. The use of T. halophilus for fish sauce fermentation improves amino acid profiles and volatile compounds as well as reduces biogenic amine content of a fish sauce product.

Characterization of Morphology, Volatile Profiles, and Molecular Markers in Edible Desert Truffles from the Negev Desert.

PubMed

Kamle, Madhu; Bar, Einat; Lewinsohn, Dalia; Shavit, Elinoar; Roth-Bejerano, Nurit; Kagan-Zur, Varda; Barak, Ze'ev; Guy, Ofer; Zaady, Eli; Lewinsohn, Efraim; Sitrit, Yaron

2017-03-28

Desert truffles are mycorrhizal, hypogeous fungi considered a delicacy. On the basis of morphological characters, we identified three desert truffle species that grow in the same habitat in the Negev desert. These include Picoa lefebvrei (Pat.), Tirmania nivea (Desf.) Trappe, and Terfezia boudieri (Chatain), all associated with Helianthemum sessiliflorum. Their taxonomy was confirmed by PCR-RFLP. The main volatiles of fruit bodies of T. boudieri and T. nivea were 1-octen-3-ol and hexanal; however, volatiles of the latter species further included branched-chain amino acid derivatives such as 2-methylbutanal and 3-methylbutanal, phenylalanine derivatives such as benzaldehyde and benzenacetaldehyde, and methionine derivatives such as methional and dimethyl disulfide. The least aromatic truffle, P. lefebvrei, contained low levels of 1-octen-3-ol as the main volatile. Axenic mycelia cultures of T. boudieri displayed a simpler volatile profile compared to its fruit bodies. This work highlights differences in the volatile profiles of desert truffles and could hence be of interest for selecting and cultivating genotypes with the most likable aroma.

Hydridosilylamido complexes of Ta and Mo isolobal with Berry's zirconocenes: syntheses, β-Si-H agostic interactions, catalytic hydrosilylation, and insight into mechanism.

PubMed

McLeod, Nicolas A; Kuzmina, Lyudmila G; Korobkov, Ilia; Howard, Judith A K; Nikonov, Georgii I

2016-02-14

The syntheses of novel Group 5 and Group 6 hydrosilylamido complexes of the type R(ArN[double bond, length as m-dash])M{N((t)Bu)SiMe2-H}X (M = Ta, R = Cp; M = Mo, R = ArN; X = Cl, H, OBn, Me) are described. The various substituents in the X position seem to play the key role in determining the extent of β-agostic interaction with the Si-H bond. The Mo agostic hydrido complex (ArN[double bond, length as m-dash])2Mo{η(3)-N((t)Bu)SiMe2-H}H is a pre-catalyst for the hydrosilylation of carbonyls. The stoichiometric reaction between benzaldehyde and (ArN[double bond, length as m-dash])2Mo{η(3)-N((t)Bu)SiMe2-H}H gives the benzoxy complex (ArN[double bond, length as m-dash])2Mo{N((t)Bu)SiMe2-H}(OBn), which showed a similar catalytic reactivity compared to the parent hydride. Mechanistic studies suggest that a non-hydride mechanism is operative.

Ultrasound accelerated Claisen Schmidt condensation: A green route to chalcones

NASA Astrophysics Data System (ADS)

Calvino, V.; Picallo, M.; López-Peinado, A. J.; Martín-Aranda, R. M.; Durán-Valle, C. J.

2006-06-01

Chalcones have been synthesized under sonochemical irradiation by Claisen-Schmidt condensation between benzaldehyde and acetophenone. Two basic activated carbons (Na and Cs-Norit) have been used as catalysts. The effect of the ultrasound activation has been studied. A substantial enhancing effect in the yield was observed when the carbon catalyst was activated under ultrasonic waves. This "green" method (combination of alkaline-doped carbon catalyst and ultrasound waves) has been applied to the synthesis of several chalcones with antibacterial properties achieving, in all cases, excellent activities and selectivities. A comparative study under non-sonic activation has showed that the yields are lower in silent conditions, indicating that the sonication exerts a positive effect on the activity of the catalyst. Cs-doped carbon is presented as the optimum catalyst, giving excellent activity for this type of condensation. Cs-Norit carbon catalyst can compete with the traditional NaOH/EtOH when the reaction is carried out under ultrasounds. The role of solvent in this reaction was studied with ethanol. High conversion was obtained in absence of solvent. The carbons were characterized by thermal analysis, nitrogen adsorption and X-ray photoelectron spectroscopy.

Characterization of Botanical and Geographical Origin of Corsican "Spring" Honeys by Melissopalynological and Volatile Analysis.

PubMed

Yang, Yin; Battesti, Marie-José; Costa, Jean; Paolini, Julien

2014-01-27

Pollen spectrum, physicochemical parameters and volatile fraction of Corsican "spring" honeys were investigated with the aim of developing a multidisciplinary method for the qualification of honeys in which nectar resources are under-represented in the pollen spectrum. Forty-one Corsican "spring" honeys were certified by melissopalynological analysis using directory and biogeographical origin of 50 representative taxa. Two groups of honeys were distinguished according to the botanical origin of samples: "clementine" honeys characterized by the association of cultivated species from oriental plain and other "spring" honeys dominated by wild herbaceous taxa from the ruderal and/or maquis area. The main compounds of the "spring" honey volatile fraction were phenylacetaldehyde, benzaldehyde and methyl-benzene. The volatile composition of "clementine" honeys was also characterized by three lilac aldehyde isomers. Statistical analysis of melissopalynological, physicochemical and volatile data showed that the presence of Citrus pollen in "clementine" honeys was positively correlated with the amount of linalool derivatives and methyl anthranilate. Otherwise, the other "spring" honeys were characterized by complex nectariferous species associations and the content of phenylacetaldehyde and methyl syringate.

Facile dimethyl amino group triggered cyclic sulfonamides synthesis and evaluation as alkaline phosphatase inhibitors.

PubMed

Bhatti, Huma Aslam; Khatoon, Memoona; Al-Rashida, Mariya; Bano, Huma; Iqbal, Nafees; Zaib-Un-Nisa; Yousuf, Sammer; Khan, Khalid Mohammed; Hameed, Abdul; Iqbal, Jamshed

2017-04-01

Owing to the biological importance of cyclic sulfonamides (sultams), herein we report a new, facile and cost-effective method for the synthesis of sultams that makes use of a reaction between dansyl amide and easily accessible benzaldehydes under mildly acidic conditions. All compounds were obtained in good yields (69-96%). Consequently a series of cyclic sulfonamides (7a-7n) was synthesized and characterized using FTIR, MS and NMR spectroscopy, crystal structure of compound 7b has also been determined. All compounds were evaluated for their potential to inhibit alkaline phosphatase (bTNAP and bIAP). All compounds were found to be excellent inhibitors of bTNAP with IC 50 values in lower micro-molar range (0.11-6.63μM). Most of the compounds were selective inhibitors of bTNAP over bIAP. Only six compounds were found to be active against bIAP (IC 50 values in the range 0.38-3.48μM). Molecular docking studies were carried out to identify and rationalize the structural elements necessary for efficient AP inhibition. Copyright © 2017 Elsevier Inc. All rights reserved.

Odor of the muskox : A preliminary investigation.

PubMed

Flood, P F; Abrams, S R; Muir, G D; Rowell, J E

1989-08-01

The behavior of captive male muskoxen was observed closely during their characteristic superiority display, the anatomy of the preputial region was studied in two adults and three calves, and preputial washings and preorbital gland secretion were subjected to gas chromatography and mass spectroscopy. During the superiority display, the prepuce was everted to form a pendulous tube tipped with a fringe of matted hair. Owing to the movement of the animal, the urine that dribbled from the preputial opening was liberally applied to the long guard hairs of the belly. The superiority display was almost exclusively confined to dominant males and apparently accounted for their odor. In the quiescent state, the hair seen around the preputial opening was drawn inside and formed an 8 cm-wide band on the lining of the prepuce. The preputial washings contained large amounts of benzoic acid andp-cresol. The infraorbital gland secretion contained cholesterol, benzaldehyde, and a homologous series of saturated γ-lactones ranging from 8 to 12 carbons. The latter compounds and the natural secretion smell similar to the human nose.

Molecular modeling and snake venom phospholipase A2 inhibition by phenolic compounds: Structure-activity relationship.

PubMed

Alam, Md Iqbal; Alam, Mohammed A; Alam, Ozair; Nargotra, Amit; Taneja, Subhash Chandra; Koul, Surrinder

2016-05-23

In our earlier study, we have reported that a phenolic compound 2-hydroxy-4-methoxybenzaldehyde from Janakia arayalpatra root extract was active against Viper and Cobra envenomations. Based on the structure of this natural product, libraries of synthetic structurally variant phenolic compounds were studied through molecular docking on the venom protein. To validate the activity of eight selected compounds, we have tested them in in vivo and in vitro models. The compound 21 (2-hydroxy-3-methoxy benzaldehyde), 22 (2-hydroxy-4-methoxybenzaldehyde) and 35 (2-hydroxy-3-methoxybenzylalcohol) were found to be active against venom-induced pathophysiological changes. The compounds 20, 15 and 35 displayed maximum anti-hemorrhagic, anti-lethal and PLA2 inhibitory activity respectively. In terms of SAR, the presence of a formyl group in conjunction with a phenolic group was seen as a significant contributor towards increasing the antivenom activity. The above observations confirmed the anti-venom activity of the phenolic compounds which needs to be further investigated for the development of new anti-snake venom leads. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Headspace, volatile and semi-volatile organic compounds diversity and radical scavenging activity of ultrasonic solvent extracts from Amorpha fruticosa honey samples.

PubMed

Jerković, Igor; Marijanović, Zvonimir; Kezić, Janja; Gugić, Mirko

2009-07-27

Volatile organic compounds of Amorpha fruticosa honey samples were isolated by headspace solid-phase microextraction (HS-SPME) and ultrasonic solvent extraction (USE), followed by gas chromatography and mass spectrometry analyses (GC, GC-MS), in order to obtain complementary data for overall characterization of the honey aroma. The headspace of the honey was dominated by 2-phenylethanol (38.3-58.4%), while other major compounds were trans- and cis-linalool oxides, benzaldehyde and benzyl alcohol. 2-Phenylethanol (10.5-16.8%) and methyl syringate (5.8-8.2%) were the major compounds of ultrasonic solvent extracts, with an array of small percentages of linalool, benzene and benzoic acid derivatives, aliphatic hydrocarbons and alcohols, furan derivatives and others. The scavenging ability of the series of concentrations of the honey ultrasonic solvent extracts and the corresponding honey samples was tested by a DPPH (1,1-diphenyl-2-picrylhydrazyl) assay. Approximately 25 times lower concentration ranges (up to 2 g/L) of the extracts exhibited significantly higher free radical scavenging potential with respect to the honey samples.

Phytochemical and physical-chemical analysis of Polish willow (Salix spp.) honey: identification of the marker compounds.

PubMed

Jerković, Igor; Kuś, Piotr Marek; Tuberoso, Carlo Ignazio Giovanni; Šarolić, Mladenka

2014-02-15

The case study of Polish Salix spp. honey was compared with published data on willow honey from other regions. GC-FID/MS (after HS-SPME and ultrasonic solvent extraction) and targeted HPLC-DAD were applied. Phenolic content, FRAP/DPPH assays and the colour coordinates were determined spectrophotometrically. Beside ubiquitous linalool derivatives, borneol (up to 10.9%), bicyclic monoterpenes with pinane skeleton (pinocarvone up to 10.6%, myrtenal up to 4.8% and verbenone up to 3.4%) and trans-β-damascenone (up to 13.0%) dominated in the headspace. The main compounds of the extractives were vomifoliol (up to 39.6%) and methyl syringate (up to 16.5%) along with not common 4-hydroxy-3-(1-methylethyl)benzaldehyde (up to 11.1%). Abscisic acid (ABA) was found (up to 53.7 mg/kg) with the isomeric ratio (Z,E)-ABA:(E,E)-ABA=1:2. The honey exhibited low antioxidant potential with pale yellow colour. The composition of Polish willow honey is similar to Mediterranean willow honeys with several relevant differences. Copyright © 2013 Elsevier Ltd. All rights reserved.

First Report on Rare Unifloral Honey of Endemic Moltkia petraea (Tratt.) Griseb. from Croatia: Detailed Chemical Screening and Antioxidant Capacity.

PubMed

Jerković, Igor; Marijanović, Zvonimir; Zekić, Marina; Tuberoso, Carlo I G

2017-03-01

Rare Moltkia petraea (Tratt.) Griseb. honey from Croatia was first time characterised. The spectrophotometric assays on CIE L*a*b*C ab *h ab ° colour coordinates, total phenol content and antioxidant capacity (FRAP, CUPRAC, DPPH • and ABTS •+ assays) determined higher honey values generally close to dark honeys ranges. Headspace solid-phase microextraction (HS-SPME) on two fibres after GC-FID and GC/MS revealed the major compounds 2-phenylacetaldehyde (12.8%; 15.6%), benzaldehyde (11.1%; 10.0%), octane (9.3%; 7.6%), nonane, propan-2-one, pentan-2-one, pentanal and nonanal (4.9%; 14.5%). Ultrasonic solvent extraction (USE) mainly isolated non-specific higher molecular compounds characteristic of the comb environment. Targeted HLPC-DAD analysis of the honey determined higher concentration of phenylalanine (212.08 mg/kg) and lumichrome (16.25 mg/kg) along with tyrosine and kojic acid. The headspace composition (chemical fingerprint) and high concentration of lumichrome can be considered particular for M. petraea honey. © 2017 Wiley-VHCA AG, Zurich, Switzerland.

Synthesis of new N-substituted 5-arylidene-2,4-thiazolidinediones as anti-inflammatory and antimicrobial agents.

PubMed

Nastasă, Cristina; Tiperciuc, Brînduşa; Pârvu, Alina; Duma, Mihaela; Ionuţ, Ioana; Oniga, Ovidiu

2013-06-01

A novel series of 5-arylidene-2,4-thiazolidinediones (TZDs) 2a-p was synthesized from the condensation of 3-((2-phenylthiazol-4-yl)methyl)thiazolidine-2,4-dione with different benzaldehyde derivatives. All the structures were confirmed by their spectral (IR, ¹H NMR, ¹³C NMR and mass) and elemental analytical data. The new molecules were evaluated in vivo as anti-inflammatory agents in an acute experimental inflammation, evaluating the acute phase bone marrow response and phagocyte activity. All compounds, excepting one, reduced the absolute leukocytes count due to the lower neutrophil percentage. Phagocytary index was decreased by the same molecules, while only half of them reduced the phagocytary activity. The effect was superior to meloxicam, the reference anti-inflammatory drug, for the majority of the TZD derivatives. The new molecules were also investigated for their antimicrobial properties on Gram-positive and Gram-negative bacteria and one fungal strain. Two compounds (2e and 2n) manifested growth inhibition capacity on all the tested strains. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Synthesis and biological activities of new furo[3,4-b]carbazoles: potential topoisomerase II inhibitors.

PubMed

Hajbi, Youssef; Neagoie, Cléopatra; Biannic, Bérenger; Chilloux, Aurélie; Vedrenne, Emeline; Baldeyrou, Brigitte; Bailly, Christian; Mérour, Jean-Yves; Rosca, Sorin; Routier, Sylvain; Lansiaux, Amélie

2010-11-01

New 1,5-dihydro-4-(substituted phenyl)-3H-furo[3,4-b]carbazol-3-ones were synthesised via a key step Diels-Alder reaction under microwave irradiation. 3-Formylindole was successfully used in a 6-step synthesis to obtain those complex heterocycles. The Diels-Alder reaction generating the carbazole ring was optimised under thermal conditions or microwave irradiation. After cleavage of functional groups, DNA binding, topoisomerase inhibition and cytotoxic properties of the new-formed furocarbazoles were investigated. These carbazoles do not present a strong interaction with the DNA, and do not modify the relaxation of the DNA in the presence of topoisomerase I or II except for one promising compound. This compound is a potent topoisomerase II inhibitor, and its cellular activity is not moderated compared to etoposide. The synthesis of these molecules allowed the generalisation of the method using indole and 5-OBn indole and several benzaldehydes. The synthesis of these molecules produced chemical structures endowed with promising cytotoxic and topoisomerase II inhibition activities. Copyright © 2010 Elsevier Masson SAS. All rights reserved.

Self-Propelled Oil Droplets and Their Morphological Change to Giant Vesicles Induced by a Surfactant Solution at Low pH.

PubMed

Banno, Taisuke; Tanaka, Yuki; Asakura, Kouichi; Toyota, Taro

2016-09-20

Unique dynamics using inanimate molecular assemblies based on soft matter have drawn much attention for demonstrating far-from-equilibrium chemical systems. However, there are no soft matter systems that exhibit a possible pathway linking the self-propelled oil droplets to formation of giant vesicles stimulated by low pH. In this study, we conceived an experimental oil-in-water emulsion system in which flocculated particles composed of a imine-containing oil transformed to spherical oil droplets that self-propelled and, after coming to rest, formed membranous figures. Finally, these figures became giant vesicles. From NMR, pH curves, and surface tension measurements, we determined that this far-from-equilibrium phenomenon was due to the acidic hydrolysis of the oil, which produced a benzaldehyde derivative as an oil component and a primary amine as a surfactant precursor, and the dynamic behavior of the hydrolytic products in the emulsion system. These findings afforded us a potential linkage between mobile droplet-based protocells and vesicle-based protocells stimulated by low pH.

Synthesis, solvatochromaticity and bioactivities of some transition metal complexes with 2-(R-benzylideneamino)-pyridin-3-ol Schiff base derivatives

NASA Astrophysics Data System (ADS)

Ahmed, I. S.; Kassem, M. A.

2010-10-01

New four Schiff bases are prepared by condensation of 2-amino-pyridin-3-ol with 3, 4-dihydroxy-benzaldehyde (I), 2-hydroxybenzaldehyde (II), 5-bromo-2-hydroxybenzaldehyde (III), and 4-dimethylaminobenzaldehyde (IV). The structures of these compounds are characterized based on elemental analyses (C. H. N), IR and 1H NMR. Also, the electronic absorption spectra are recorded in organic solvents of different polarity. The solvents are selected to be covered a wide range of parameters (refractive index, dielectric constant and hydrogen bonding capacity). The UV-vis absorption spectra of Schiff base compounds are investigated in aqueous buffer solutions of varying pH and utilized for the determination of ionization constant, p Ka and activation free energy, Δ G* of the ionization process. The biological activity against bacterial species and fungi as microorganisms representing different microbial categories such as (two Gram-negative bacteria, Eschericha coli and Agrobacterium sp.),three Gram-positive bacteria ( Staphylococcus aureus, Bacillus subtlus and Bacillus megatherium), yeast ( Candida albicans), and fungi ( Aspergillus niger) were studied.

Constitutive and inducible resistance to Atherigona soccata (Diptera: Muscidae) in Sorghum bicolor.

PubMed

Chamarthi, Siva K; Vijay, Peter M; Sharma, Hari C; Narasu, Lakshmi M

2012-06-01

Host plant resistance is one of the important components for minimizing the losses because of sorghum shoot fly, Atherigona soccata (Diptera: Muscidae) attack. Therefore, we studied the constitutive and inducible biochemical mechanisms of resistance to A. soccata in a diverse array of sorghum genotypes to identify lines with diverse mechanisms of resistance to this insect. Fifteen sorghum genotypes with different levels of resistance to A. soccata were evaluated. Methanol extracts of 10-d old damaged and undamaged sorghum seedlings were subjected to high-performance liquid chromatography analysis. Association between peak areas of the identified and unidentified compounds with parameters measuring A. soccata resistance was determined through correlation analysis. Amounts of p-hydroxy benzaldehyde and the unidentified compounds at RTs 24.38 and 3.70 min were associated with susceptibility to A. soccata. Genotypes exhibiting resistance to A. soccata were placed in four groups, and the lines showing constitutive and/or induced resistance to A. soccata with different combinations of biochemical factors potentially could be used for increasing the levels of resistance to A. soccata in sorghum.

Structural and catalytic properties of some azo-rhodanine Ruthenium(III) complexes

NASA Astrophysics Data System (ADS)

Shoair, A. F.; El-Bindary, A. A.; Abd El-Kader, M. K.

2017-09-01

Novel azo-rhodanine ruthenium(III) complexes of the type trans-[Ru(Ln)2(AsPh3)2]Cl (Ln = monobasic bidentate anions of 5-(4‧-methoxyphenylazo)-3-phenylamino-2-thioxothiazolidin-4-one (HL1), 5-(phenylazo)-3-phenylamino-2-thioxothiazolidin-4-one (HL2) and 5-(4‧-chlorophenylazo)-3-phenylamino-2-thioxothiazolidin-4-one (HL3); AsPh3 = triphenylarsine) have been synthesized and characterized by elemental analysis, spectroscopic (IR, 1H NMR and UV-VIS), magnetic, X-ray diffraction, mass spectra and thermal analysis techniques. These techniques confirm the formation of octahedral ruthenium(III) complexes. The Ru(III) complexes were tested as a catalysts for the oxidation of benzyl alcohol to benzaldehyde with N-methylmorpholine-N-oxide as a co-oxidant. The effect of time, temperature, and solvent were also studied and the mechanism of this catalytic oxidation reaction is suggested. Molecular docking was used to predict the binding between azo rhodanine derivatives (HLn) with the receptor of 3qum- immune system receptor of human prostate specific antigen (PSA) in a Fab sandwich with a high affinity and a PCa selective antibody.

Thermophilic enzymes and their applications in biocatalysis: a robust aldo-keto reductase.

PubMed

Willies, Simon; Isupov, Misha; Littlechild, Jennifer

2010-09-01

Extremophiles are providing a good source of novel robust enzymes for use in biocatalysis for the synthesis of new drugs. This is particularly true for the enzymes from thermophilic organisms which are more robust than their mesophilic counterparts to the conditions required for industrial bio-processes. This paper describes a new aldo-keto reductase enzyme from a thermophilic eubacteria, Thermotoga maritima which can be used for the production of primary alcohols. The enzyme has been cloned and over-expressed in Escherichia coli and has been purified and subjected to full biochemical characterization. The aldo-keto reductase can be used for production of primary alcohols using substrates including benzaldehyde, 1,2,3,6-tetrahydrobenzaldehyde and para-anisaldehyde. It is stable up to 80 degrees C, retaining over 60% activity for 5 hours at this temperature. The enzyme at pH 6.5 showed a preference for the forward, carbonyl reduction. The enzyme showed moderate stability with organic solvents, and retained 70% activity in 20% (v/v) isopropanol or DMSO. These properties are favourable for its potential industrial applications.

Extended reaction scope of thiamine diphosphate dependent cyclohexane-1,2-dione hydrolase: from C-C bond cleavage to C-C bond ligation.

PubMed

Loschonsky, Sabrina; Wacker, Tobias; Waltzer, Simon; Giovannini, Pier Paolo; McLeish, Michael J; Andrade, Susana L A; Müller, Michael

2014-12-22

ThDP-dependent cyclohexane-1,2-dione hydrolase (CDH) catalyzes the CC bond cleavage of cyclohexane-1,2-dione to 6-oxohexanoate, and the asymmetric benzoin condensation between benzaldehyde and pyruvate. One of the two reactivities of CDH was selectively knocked down by mutation experiments. CDH-H28A is much less able to catalyze the CC bond formation, while the ability for CC bond cleavage is still intact. The double variant CDH-H28A/N484A shows the opposite behavior and catalyzes the addition of pyruvate to cyclohexane-1,2-dione, resulting in the formation of a tertiary alcohol. Several acyloins of tertiary alcohols are formed with 54-94 % enantiomeric excess. In addition to pyruvate, methyl pyruvate and butane-2,3-dione are alternative donor substrates for CC bond formation. Thus, the very rare aldehyde-ketone cross-benzoin reaction has been solved by design of an enzyme variant. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Dual-mesoporous ZSM-5 zeolite with highly b-axis-oriented large mesopore channels for the production of benzoin ethyl ether.

PubMed

Zhou, Xiaoxia; Chen, Hangrong; Zhu, Yan; Song, Yudian; Chen, Yu; Wang, Yongxia; Gong, Yun; Zhang, Guobin; Shu, Zhu; Cui, Xiangzhi; Zhao, Jinjin; Shi, Jianlin

2013-07-22

Dual-mesoporous ZSM-5 zeolite with highly b axis oriented large mesopores was synthesized by using nonionic copolymer F127 and cationic surfactant CTAB as co-templates. The product contains two types of mesopores--smaller wormlike ones of 3.3 nm in size and highly oriented larger ones of 30-50 nm in diameter along the b axis--and both of them interpenetrate throughout the zeolite crystals and interconnect with zeolite microporosity. The dual-mesoporous zeolite exhibits excellent catalytic performance in the condensation of benzaldehyde with ethanol and greater than 99 % selectivity for benzoin ethyl ether at room temperature, which can be ascribed to the zeolite lattice structure offering catalytically active sites and the hierarchical and oriented mesoporous structure providing fast access of reactants to these sites in the catalytic reaction. The excellent recyclability and high catalytic stability of the catalyst suggest prospective applications of such unique mesoporous zeolites in the chemical industry. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Effectiveness of water-air and octanol-air partition coefficients to predict lipophilic flavor release behavior from O/W emulsions.

PubMed

Tamaru, Shunji; Igura, Noriyuki; Shimoda, Mitsuya

2018-01-15

Flavor release from food matrices depends on the partition of volatile flavor compounds between the food matrix and the vapor phase. Thus, we herein investigated the relationship between released flavor concentrations and three different partition coefficients, namely octanol-water, octanol-air, and water-air, which represented the oil, water, and air phases present in emulsions. Limonene, 2-methylpyrazine, nonanal, benzaldehyde, ethyl benzoate, α-terpineol, benzyl alcohol, and octanoic acid were employed. The released concentrations of these flavor compounds from oil-in-water (O/W) emulsions were measured under equilibrium using static headspace gas chromatography. The results indicated that water-air and octanol-air partition coefficients correlated with the logarithms of the released concentrations in the headspace for highly lipophilic flavor compounds. Moreover, the same tendency was observed over various oil volume ratios in the emulsions. Our findings therefore suggest that octanol-air and water-air partition coefficients can be used to predict the released concentration of lipophilic flavor compounds from O/W emulsions. Copyright © 2017 Elsevier Ltd. All rights reserved.

Multiple headspace-solid-phase microextraction: an application to quantification of mushroom volatiles.

PubMed

Costa, Rosaria; Tedone, Laura; De Grazia, Selenia; Dugo, Paola; Mondello, Luigi

2013-04-03

Multiple headspace-solid phase microextraction (MHS-SPME) followed by gas chromatography/mass spectrometry (GC-MS) and flame ionization detection (GC-FID) was applied to the identification and quantification of volatiles released by the mushroom Agaricus bisporus, also known as champignon. MHS-SPME allows to perform quantitative analysis of volatiles from solid matrices, free of matrix interferences. Samples analyzed were fresh mushrooms (chopped and homogenized) and mushroom-containing food dressings. 1-Octen-3-ol, 3-octanol, 3-octanone, 1-octen-3-one and benzaldehyde were common constituents of the samples analyzed. Method performance has been tested through the evaluation of limit of detection (LoD, range 0.033-0.078 ng), limit of quantification (LoQ, range 0.111-0.259 ng) and analyte recovery (92.3-108.5%). The results obtained showed quantitative differences among the samples, which can be attributed to critical factors, such as the degree of cell damage upon sample preparation, that are here discussed. Considerations on the mushrooms biochemistry and on the basic principles of MHS analysis are also presented. Copyright © 2013 Elsevier B.V. All rights reserved.

Volatile Flavor Compounds Produced by Molds of Aspergillus, Penicillium, and Fungi imperfecti.

PubMed

Kaminski, E; Stawicki, S; Wasowicz, E

1974-06-01

Strains of molds Aspergillus niger, A. ochraceus, A. oryzae, A. parasiticus, Penicillium chrysogenum, P. citrinum, P. funiculosum, P. raistrickii, P. viridicatum, Alternaria, Cephalosporium, and Fusarium sp. were grown on sterile coarse wheat meal at 26 to 28 C for 120 h. The volatiles from mature cultures were distilled at low temperature under reduced pressure. The distillates from traps -40 and -78 C were extracted with methylene chloride and subsequently concentrated. All the concentrates thus obtained were analyzed by gas-liquid chromatography, mass spectrometry, chemical reactions of functional groups, and olfactory evaluation. Six components detected in the culture distillates were identified positively: 3-methylbutanol, 3-octanone, 3-octanol, 1-octen-3-ol, 1-octanol, and 2-octen-1-ol. They represented 67 to 97% of all the volatiles occurring in the concentrated distillate. The following 14 components were identified tentatively: octane, isobutyl alcohol, butyl alcohol, butyl acetate, amyl acetate, octyl acetate, pyridine, hexanol, nonanone, dimethylpyrazine, tetramethylpyrazine, benzaldehyde, propylbenzene, and phenethyl alcohol. Among the volatiles produced by molds, 1-octen-3-ol yielding a characteristic fungal odor was found predominant.

Volatile Flavor Compounds Produced by Molds of Aspergillus, Penicillium, and Fungi imperfecti

PubMed Central

Kaminski, E.; Stawicki, S.; Wasowicz, E.

1974-01-01

Strains of molds Aspergillus niger, A. ochraceus, A. oryzae, A. parasiticus, Penicillium chrysogenum, P. citrinum, P. funiculosum, P. raistrickii, P. viridicatum, Alternaria, Cephalosporium, and Fusarium sp. were grown on sterile coarse wheat meal at 26 to 28 C for 120 h. The volatiles from mature cultures were distilled at low temperature under reduced pressure. The distillates from traps -40 and -78 C were extracted with methylene chloride and subsequently concentrated. All the concentrates thus obtained were analyzed by gas-liquid chromatography, mass spectrometry, chemical reactions of functional groups, and olfactory evaluation. Six components detected in the culture distillates were identified positively: 3-methylbutanol, 3-octanone, 3-octanol, 1-octen-3-ol, 1-octanol, and 2-octen-1-ol. They represented 67 to 97% of all the volatiles occurring in the concentrated distillate. The following 14 components were identified tentatively: octane, isobutyl alcohol, butyl alcohol, butyl acetate, amyl acetate, octyl acetate, pyridine, hexanol, nonanone, dimethylpyrazine, tetramethylpyrazine, benzaldehyde, propylbenzene, and phenethyl alcohol. Among the volatiles produced by molds, 1-octen-3-ol yielding a characteristic fungal odor was found predominant. PMID:16349989

[Chemical constituents from whole plants of Aconitum tanguticum (III)].

PubMed

Li, Yan-Rong; Li, Chun; Wang, Zhi-Min; Yang, Li-Xin

2014-04-01

Nineteen compounds were isolated from the whole plants of Aconitum tanguticum by various of chromatographic techniques and their structures were determined through spectral analysis (1D, 2D-NMR and MS) and comparison with the literature data. These compounds were identified as 5-hydroxymethy furfural (1), 5-acetoxymethyl furfural (2), pyrrolezanthine [5-hydroxymethyl-1-[2-(4-hydroxyphenyl) -ethyl] -1H-pyrrole-2-carbaldehyde] (3), lichiol B (4), phthalic acid dibutyl ester (5), 3, 4-dihydroxy phenylethanol (6), 3, 4-dihydroxy phenylethanol glucoside (7), salidroside (8), p-hydroxy phenylethanol (9), p-hydroxybenzoie acid glucoside (10), p-hydroxybenzoic acid (11), gastrodin (12), 1-(3, 4-dimethoxyphenyl) -1, 2-ethanediol (13), p-hydroxy benzaldehyde (14), p-hydroxy acetophenone (15), 3, 4-dihydroxy phenyl ethyl acetate (16), syringic aldehyde (17), ethyl beta-D-fructopyranoside (18), and p-hydroxybenzoic acid methyl ester (19). Compounds 3 and 4 were isolated from the Ranunculaceae family for the first time, and compounds 2, 6 and 9-19 were isolated from the Aconitum genus for the first time, and compounds 1 and 5 were isolated from the species for the first time.

Microbial biodiesel production from oil palm biomass hydrolysate using marine Rhodococcus sp. YHY01.

PubMed

Bhatia, Shashi Kant; Kim, Junyoung; Song, Hun-Seok; Kim, Hyun Joong; Jeon, Jong-Min; Sathiyanarayanan, Ganesan; Yoon, Jeong-Jun; Park, Kyungmoon; Kim, Yun-Gon; Yang, Yung-Hun

2017-06-01

The effect of various biomass derived inhibitors (i.e. furfural, hydroxymethylfurfural (HMF), vanillin, 4-hydroxy benzaldehyde (4-HB) and acetate) was investigated for fatty acid accumulation in Rhodococcus sp. YHY 01. Rhodococcus sp. YHY01 was able to utilize acetate, vanillin, and 4-HB for biomass production and fatty acid accumulation. The IC 50 value for furfural (3.1mM), HMF (3.2mM), vanillin (2.0mM), 4-HB (2.7mM) and acetate (3.7mM) was calculated. HMF and vanillin affect fatty acid composition and increase saturated fatty acid content. Rhodococcus sp. YHY 01 cultured with empty fruit bunch hydrolysate (EFBH) as the main carbon source resulted in enhanced biomass (20%) and fatty acid productivity (37%), in compression to glucose as a carbon source. Overall, this study showed the beneficial effects of inhibitory molecules on growth and fatty acid production, and support the idea of biomass hydrolysate utilization for biodiesel production by avoiding complex efforts to remove inhibitory compounds. Copyright © 2017 Elsevier Ltd. All rights reserved.

Photoinduced intramolecular charge transfer and photophysical characteristics of (2Z)-3-[4-(dimethylamino) phenyl]-2-(2-methylphenyl) prop-2-ene-nitrile (DPM) in different media

NASA Astrophysics Data System (ADS)

Asiri, Abdullah M.; El-Daly, Samy A.; Alamry, Khalid A.; Arshad, Muhammad Nadeem; Pannipara, Mehboobali

2015-10-01

A new fluorophore, (2Z)-3-[4-(dimethylamino) phenyl]-2-(2-methylphenyl) prop-2-ene-nitrile (DPM), was synthesized by knoevenagel condensation of 4-(dimethylamino) benzaldehyde and 2-methylbenzyl cyanide in ethanol using NaOH as base. The electronic absorption and emission characteristic of DPM was studied in different solvents. The X-ray crystallographic structure of DPM was also investigated. A crystalline solid of DPM gives a strong green emission at about 533 nm; these phenomena are important for the application of DPM dye in organic photo emitting diode. DPM exhibits a red shift in its emission spectrum as solvent polarity increases, indicating a large change in the dipole moment of dye molecule upon excitation due to intramolecular charge transfer in excited DPM*. The fluorescence quantum yield depends strongly on the properties of the solvents, which was attributed to positive and negative solvatokinetic effects. The DPM dye displays solubilization in cationic (CTAB) micelle and could be used as a probe to determine the critical micelle concentration (CMC) of CTAB.

Efficient synthetic protocols in glycerol under heterogeneous catalysis.

PubMed

Cravotto, Giancarlo; Orio, Laura; Gaudino, Emanuela Calcio; Martina, Katia; Tavor, Dorith; Wolfson, Adi

2011-08-22

The massive increase in glycerol production from the transesterification of vegetable oils has stimulated a large effort to find novel uses for this compound. Hence, the use of glycerol as a solvent for organic synthesis has drawn particular interest. Drawbacks of this green and renewable solvent are a low solubility of highly hydrophobic molecules and a high viscosity, which often requires the use of a fluidifying co-solvent. These limitations can be easily overcome by performing reactions under high-intensity ultrasound and microwaves in a stand-alone or combined manner. These non-conventional techniques facilitate and widen the use of glycerol as a solvent in organic synthesis. Glycerol allows excellent acoustic cavitation even at high temperatures (70-100 °C), which is otherwise negligible in water. Herein, we describe three different types of applications: 1) the catalytic transfer hydrogenation of benzaldehyde to benzyl alcohol in which glycerol plays the dual role of the solvent and hydrogen donor; 2) the palladium-catalyzed Suzuki cross-coupling; and (3) the Barbier reaction. In all cases glycerol proved to be a greener, less expensive, and safer alternative to the classic volatile organic solvents. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Synthesis, characterization and biological activity of C6-Schiff bases derivatives of chitosan.

PubMed

Xu, Ruibo; Aotegen, Bayaer; Zhong, Zhimei

2017-12-01

C 6 -Schiff bases derivatives of chitosan were synthesized for the first time. C 2 -amino groups and C 3 -hydroxy groups were firstly protected by CuSO 4 ·5H 2 O, and the C 6 -hydroxy was then transformed into aldehyde, which then reacted with anilines through nucleophilic addition to introduce the CN group at C 6 -position in chitosan chain. Finally, C 6 -Schiff bases derivatives of chitosan were got by the deprotection of C 2 -NH 2 with cation exchange resin. The structures and properties of the new synthesized products were characterized by Fourier transform infrared spectroscopy, 13 C NMR, SEM image, and elemental analysis. The antibacterial activities of derivatives were tested in the experiment, and the results showed that the prepared chitosan derivatives had significantly improved antibacterial activity toward Staphylococcus aureus and Escherichia coli. The Cytotoxicity test showed that the prepared chitosan derivatives had low Cytotoxicity, compared with chitosan and C 2 -benzaldehyde Schiff bases of chitosan. This paper allowed a new method for the synthesis of Schiff bases of chitosan, which was enlightening. Copyright © 2017 Elsevier B.V. All rights reserved.

Determination of Carbonyl Compounds in Cork Agglomerates by GDME-HPLC-UV: Identification of the Extracted Compounds by HPLC-MS/MS.

PubMed

Brandão, Pedro Francisco; Ramos, Rui Miguel; Almeida, Paulo Joaquim; Rodrigues, José António

2017-02-08

A new approach is proposed for the extraction and determination of carbonyl compounds in solid samples, such as wood or cork materials. Cork products are used as building materials due to their singular characteristics; however, little is known about its aldehyde emission potential and content. Sample preparation was done by using a gas-diffusion microextraction (GDME) device for the direct extraction of volatile aldehydes and derivatization with 2,4-dinitrophenylhydrazine. Analytical determination of the extracts was done by HPLC-UV, with detection at 360 nm. The developed methodology proved to be a reliable tool for aldehyde determination in cork agglomerate samples with suitable method features. Mass spectrometry studies were performed for each sample, which enabled the identification, in the extracts, of the derivatization products of a total of 13 aldehydes (formaldehyde, acetaldehyde, furfural, propanal, 5-methylfurfural, butanal, benzaldehyde, pentanal, hexanal, trans-2-heptenal, heptanal, octanal, and trans-2-nonenal) and 4 ketones (3-hydroxy-2-butanone, acetone, cyclohexanone, and acetophenone). This new analytical methodology simultaneously proved to be consistent for the identification and determination of aldehydes in cork agglomerates and a very simple and straightforward procedure.

Kinetics of acetaminophen degradation by Fenton oxidation in a fluidized-bed reactor.

PubMed

de Luna, Mark Daniel G; Briones, Rowena M; Su, Chia-Chi; Lu, Ming-Chun

2013-01-01

Acetaminophen (ACT), an analgesic and antipyretic substance, is one of the most commonly detected pharmaceutical compound in surface waters and wastewaters. In this study, fluidized-bed Fenton (FB-Fenton) was used to decompose ACT into its final degradation products. The 1.45-L cylindrical glass reactor had inlet, outlet and recirculating sections. SiO(2) carrier particles were supported by glass beads with 2-4 mm in diameter. ACT concentration was determined by high performance liquid chromatography (HPLC). During the first 40 min of reaction, a fast initial ACT removal was observed and the "two-stage" ACT degradation conformed to a pseudo reaction kinetics. The effects of ferrous ion dosage and [Fe(2+)]/[H(2)O(2)] (FH ratio) were integrated into the derived pseudo second-order kinetic model. A reaction pathway was proposed based on the intermediates detected through SPME/GC-MS. The aromatic intermediates identified were hydroquinone, benzaldehydes and benzoic acids while the non-aromatic substances include alcohols, ketones, aldehydes and carboxylic acids. Rapid initial ACT degradation rate can be accomplished by high initial ferrous ion concentration and/or low FH ratio. Copyright © 2012 Elsevier Ltd. All rights reserved.

Synthetic bioactive novel ether based Schiff bases and their copper(II) complexes

NASA Astrophysics Data System (ADS)

Shabbir, Muhammad; Akhter, Zareen; Ismail, Hammad; Mirza, Bushra

2017-10-01

Novel ether based Schiff bases (HL1- HL4) were synthesized from 5-chloro-2-hydroxy benzaldehyde and primary amines (1-amino-4-phenoxybenzene, 4-(4-aminophenyloxy) biphenyl, 1-(4-aminophenoxy) naphthalene and 2-(4-aminophenoxy) naphthalene). From these Schiff bases copper(II) complexes (Cu(L1)2-Cu(L4)2)) were synthesized and characterized by elemental analysis and spectroscopic (FTIR, NMR) techniques. The synthesized Schiff bases and copper(II) complexes were further assessed for various biological studies. In brine shrimp assay the copper(II) complexes revealed 4-fold higher activity (LD50 3.8 μg/ml) as compared with simple ligands (LD50 12.4 μg/ml). Similar findings were observed in potato disc antitumor assay with higher activities for copper(II) complexes (IC50 range 20.4-24.1 μg/ml) than ligands (IC50 range 40.5-48.3 μg/ml). DPPH assay was performed to determine the antioxidant potential of the compounds. Significant antioxidant activity was shown by the copper(II) complexes whereas simple ligands have shown no activity. In DNA protection assay significant protection behavior was exhibited by simple ligand molecules while copper(II) complexes showed neutral behavior (neither protective nor damaging).

Laccase/mediator assisted degradation of triarylmethane dyes in a continuous membrane reactor.

PubMed

Chhabra, Meenu; Mishra, Saroj; Sreekrishnan, Trichur Ramaswamy

2009-08-10

Laccase/mediator systems are important bioremediation agents as the rates of reactions can be enhanced in the presence of the mediators. The decolorization mechanism of two triarylmethane dyes, namely, Basic Green 4 and Acid Violet 17 is reported using Cyathus bulleri laccase. Basic Green 4 was decolorized through N-demethylation by laccase alone, while in mediator assisted reactions, dye breakdown was initiated from oxidation of carbinol form of the dye. Benzaldehyde and N,N-dimethyl aniline were the major end products. With Acid Violet 17, laccase carried out N-deethylation and in mediator assisted reactions, oxidation of the carbinol form of the dye occurred resulting in formation of formyl benzene sulfonic acid, carboxy benzene sulfonic acid and benzene sulfonic acid. Toxicity analysis revealed that Basic Green 4 was toxic and treatment with laccase/mediators resulted in 80-100% detoxification. The treatment of the textile dye solution using laccase and 2,2'-azino-di-(-ethylbenzothiazoline-6-sulfonic acid) (ABTS) was demonstrated in an enzyme membrane reactor. At a hydraulic retention time of 6h, the process was operated for a period of 15 days with nearly 95% decolorization, 10% reduction in flux and 70% recovery of active ABTS.

Trichocyanines: a Red-Hair-Inspired Modular Platform for Dye-Based One-Time-Pad Molecular Cryptography.

PubMed

Leone, Loredana; Pezzella, Alessandro; Crescenzi, Orlando; Napolitano, Alessandra; Barone, Vincenzo; d'Ischia, Marco

2015-06-01

Current molecular cryptography (MoCryp) systems are almost exclusively based on DNA chemistry and reports of cryptography technologies based on other less complex chemical systems are lacking. We describe herein, as proof of concept, the prototype of the first asymmetric MoCryp system, based on an 8-compound set of a novel bioinspired class of cyanine-type dyes called trichocyanines. These novel acidichromic cyanine-type dyes inspired by red hair pigments were synthesized and characterized with the aid of density functional theory (DFT) calculations. Trichocyanines consist of a modular scaffold easily accessible via an expedient condensation of 3-phenyl- or 3-methyl-2H-1,4-benzothiazines with N-dimethyl- or o-methoxyhydroxy-substituted benzaldehyde or cinnamaldehyde derivatives. The eight representative members synthesized herein can be classified as belonging to two three-state systems tunable through four different control points. This versatile dye platform can generate an expandable palette of colors and appears to be specifically suited to implement an unprecedented single-use asymmetric molecular cryptography system. With this system, we intend to pioneer the translation of digital public-key cryptography into a chemical-coding one-time-pad-like system.

Trichocyanines: a Red-Hair-Inspired Modular Platform for Dye-Based One-Time-Pad Molecular Cryptography

PubMed Central

Leone, Loredana; Pezzella, Alessandro; Crescenzi, Orlando; Napolitano, Alessandra; Barone, Vincenzo; d’Ischia, Marco

2015-01-01

Current molecular cryptography (MoCryp) systems are almost exclusively based on DNA chemistry and reports of cryptography technologies based on other less complex chemical systems are lacking. We describe herein, as proof of concept, the prototype of the first asymmetric MoCryp system, based on an 8-compound set of a novel bioinspired class of cyanine-type dyes called trichocyanines. These novel acidichromic cyanine-type dyes inspired by red hair pigments were synthesized and characterized with the aid of density functional theory (DFT) calculations. Trichocyanines consist of a modular scaffold easily accessible via an expedient condensation of 3-phenyl- or 3-methyl-2H-1,4-benzothiazines with N-dimethyl- or o-methoxyhydroxy-substituted benzaldehyde or cinnamaldehyde derivatives. The eight representative members synthesized herein can be classified as belonging to two three-state systems tunable through four different control points. This versatile dye platform can generate an expandable palette of colors and appears to be specifically suited to implement an unprecedented single-use asymmetric molecular cryptography system. With this system, we intend to pioneer the translation of digital public-key cryptography into a chemical-coding one-time-pad-like system. PMID:26246999

Chemical composition and antimicrobial activity of the essential oil of apricot seed.

PubMed

Lee, Hyun-Hee; Ahn, Jeong-Hyun; Kwon, Ae-Ran; Lee, Eun Sook; Kwak, Jin-Hwan; Min, Yu-Hong

2014-12-01

In traditional oriental medicine, apricot (Prunus armeniaca L.) seed has been used to treat skin diseases such as furuncle, acne vulgaris and dandruff, as well as coughing, asthma and constipation. This study describes the phytochemical profile and antimicrobial potential of the essential oil obtained from apricot seeds (Armeniacae Semen). The essential oil isolated by hydrodistillation was analysed by gas chromatography-mass spectroscopy. Benzaldehyde (90.6%), mandelonitrile (5.2%) and benzoic acid (4.1%) were identified. Disc diffusion, agar dilution and gaseous contact methods were performed to determine the antimicrobial activity against 16 bacteria and two yeast species. The minimum inhibitory concentrations ranged from 250 to 4000, 500 to 2000 and 250 to 1000 µg/mL for Gram-positive bacteria, Gram-negative bacteria and yeast strains, respectively. The minimum inhibitory doses by gaseous contact ranged from 12.5 to 50, 12.5 to 50 and 3.13 to 12.5 mg/L air for Gram-positive bacteria, Gram-negative bacteria and yeast strains, respectively. The essential oil exhibited a variable degree of antimicrobial activity against a range of bacteria and yeasts tested. Copyright © 2014 John Wiley & Sons, Ltd.

Desalination of fish sauce by electrodialysis: effect on selected aroma compounds and amino acid compositions.

PubMed

Chindapan, Nathamol; Devahastin, Sakamon; Chiewchan, Naphaporn; Sablani, Shyam S

2011-09-01

Fish sauce is an ingredient that exhibits unique flavor and is widely used by people in Southeast Asia. Fish sauce, however, contains a significant amount of salt (sodium chloride). Recently, electrodialysis (ED) has been successfully applied to reduce salt in fish sauce; however, no information is available on the effect of ED on changes in compounds providing aroma and taste of ED-treated fish sauce. The selected aroma compounds, amino acids, and sensory quality of the ED-treated fish sauce with various salt concentrations were then analyzed. The amounts of trimethylamine, 2,6-dimethylpyrazine, phenols, and all carboxylic acids except for hexanoic acid significantly decreased, whereas benzaldehyde increased significantly when the salt removal level was higher. The amounts of all amino acids decreased with the increased salt removal level. Significant difference in flavor and saltiness intensity among ED-treated fish sauce with various salt concentrations, as assessed by a discriminative test, were observed. Information obtained in this work can serve as a guideline for optimization of a process to produce low-sodium fish sauce by ED. It also forms a basis for further in-depth sensory analysis of low-sodium fish sauce. © 2011 Institute of Food Technologists®

Synthesis and property of solvatochromic fluorophore based on D-pi-A molecular system: 2-[[3-cyano-4-(N-ethyl-N-(2-hydroxyethyl)amino)styryl]-5,5-dimethylfuran-2(5H)-ylidene]malononitrile dye.

PubMed

Son, Young-A; Gwon, Seon-Yeong; Lee, Sue-Yoen; Kim, Sung-Hoon

2010-01-01

2-[[3-Cyano-4-(N-ethyl-N-(2-hydroxyethyl)amino)styryl]-5,5-dimethylfuran-2(5H)-ylidene]malononitrile styryl dye was prepared by the condensation of 4-[(2-hydroxy-ethyl)-methyl-amino]-benzaldehyde (donor moiety) with 2-cyanomethylene-3-cyano-4,5,5-trimethyl-2,5-dihydrofuran (acceptor moiety). The corresponding design, synthesis and solvatochromic characteristics of the intramolecular charge-transfer (ICT) dye chromophore were discussed and determined. Optical properties such as absorption and fluorescence emission spectra were monitored in several solvent media with different polarity. In this determination, the prepared dye chromophore showed positive solvatochromism effect and the resulting solvatochromic characteristics were studied with semiempirical calculations. The energy potentials of this dye chromophore such as HOMO and LUMO values were calculated by computational simulation approaches using Material Studio 4.3. Furthermore, the functions as a molecular switching sensor with pH stimulation of alkali-acid addition were determined in DMSO, which was operated by deprotonation/protonation effects based on intramolecular charge-transfer system. Copyright 2009 Elsevier B.V. All rights reserved.

Low temperature oxidation of benzene and toluene in mixture with n-decane

PubMed Central

Herbinet, Olivier; Husson, Benoit; Ferrari, Maude; Glaude, Pierre-Alexandre; Battin-Leclerc, Frédérique

2013-01-01

The oxidation of two blends, benzene/n-decane and toluene/n-decane, was studied in a jet-stirred reactor with gas chromatography analysis (temperatures from 500 to 1100 K, atmospheric pressure, stoichiometric mixtures). The studied hydrocarbon mixtures contained 75% of aromatics in order to highlight the chemistry of the low-temperature oxidation of these two aromatic compounds which have a very low reactivity compared to large alkanes. The difference of behavior between the two aromatic reactants is highly pronounced concerning the formation of derived aromatic products below 800 K. In the case of benzene, only phenol could be quantified. In the case of toluene, significant amounts of benzaldehyde, benzene, and cresols were also formed, as well as several heavy aromatic products such as bibenzyl, phenylbenzylether, methylphenylbenzylether, and ethylphenylphenol. A comparison with results obtained with neat n-decane showed that the reactivity of the alkane is inhibited by the presence of benzene and, to a larger extent, toluene. An improved model for the oxidation of toluene was developed based on recent theoretical studies of the elementary steps involved in the low-temperature chemistry of this molecule. Simulations using this model were successfully compared with the obtained experimental results. PMID:23762017

Synthesis and characterization of Cr-MSU-1 and its catalytic application for oxidation of styrene

NASA Astrophysics Data System (ADS)

Liu, Hong; Wang, Zhigang; Hu, Hongjiu; Liang, Yuguang; Wang, Mengyang

2009-07-01

Chromium-containing mesoporous silica material Cr-MSU-1 was synthesized using lauryl alcohol-polyoxyethylene (23) ether as templating agent under the neutral pH condition by two-step method. The sample was characterized by XRD, TEM, FT-IR, UV-Vis, ESR, ICP-AES and N 2 adsorption. Its catalytic performance for oxidation of styrene was studied. Effects of the solvent used, the styrene/H 2O 2 mole ratio and the reaction temperature and time on the oxidation of styrene over the Cr-MSU-1 catalyst were examined. The results indicate that Cr ions have been successfully incorporated into the framework of MSU-1 and the Cr-MSU-1 material has a uniform worm-like holes mesoporous structure. After Cr-MSU-1 is calcined, most of Cr 3+ is oxidized to Cr 5+ and Cr 6+ in tetrahedral coordination and no extra-framework Cr 2O 3 is formed. The Cr-MSU-1 catalyst is highly active for the selective oxidation of styrene and the main reaction products over Cr-MSU-1 are benzaldehyde and phenylacetaldehyde. Its catalytic performance remains stable within five repeated runs and no leaching is noticed for this chromium-based catalyst.

Improved rate of substrate oxidation catalyzed by genetically-engineered myoglobin.

PubMed

Chand, Subhash; Ray, Sriparna; Wanigasekara, Eranda; Yadav, Poonam; Crawford, Joshua A; Armstrong, Daniel W; Rajeshwar, Krishnan; Pierce, Brad S

2018-02-01

This study showcases the potential of unnatural amino acids to enable non-natural functions when incorporated in the protein scaffold of heme metalloproteins. For this purpose, a genetically-engineered myoglobin (Mb) mutant was created by incorporating redox-active 3-amino-l-tyrosine (NH 2 Tyr) into its active site, replacing the distal histidine (H64) with NH 2 Tyr. In peroxide-shunt assays, this variant exhibits an increased rate of turnover for thioanisole and benzaldehyde oxidation as compared to the wild-type (WT) Mb. Indeed, in the presence of excess hydrogen peroxide (H 2 O 2 ), a 9-fold and 81-fold increase in activity was observed over multiple turnovers for thioanisole sulfoxidation and benzoic acid formation, respectively. The increased oxidation activity in the H64NH 2 Tyr Mb mutant underlined the role of NH 2 Tyr in the distal active-site scaffold in peroxide activation. Kinetic, electrochemical, and EPR spectroscopic experiments were performed. On the basis of these studies, it is argued that the single NH 2 Tyr residue within the Mb variant simultaneously serves the role of the conserved His/Arg-pair within the distal pocket of horseradish peroxidase. Copyright © 2018 Elsevier Inc. All rights reserved.

Phytochemical study of the headspace volatile organic compounds of fresh algae and seagrass from the Adriatic Sea (single point collection)

PubMed Central

Marijanović, Zvonimir; Roje, Marin; Kuś, Piotr M.; Jokić, Stela; Čož-Rakovac, Rozelinda

2018-01-01

Performed phytochemical study contributes to the knowledge of volatile organic compounds (VOCs) of Halopteris filicina (Grateloup) Kützing, Dictyota dichotoma (Hudson) J. V. Lamouroux, Posidonia oceanica (L.) Delile and Flabellia petiolata (Turra) Nizamuddin from the Adriatic Sea (single point collection). VOCs were investigated by headspace solid-phase microextraction (HS-SPME) and analysed by gas chromatography and mass spectrometry (GC-MS/FID). H. filicina headspace contained dimethyl sulfide (DMS; 12.8%), C8-compounds (e.g. fucoserratene (I; 9.5%)), benzaldehyde (II; 8.7%), alkane C17, dictyopterene D and C (III, IV), tribromomethane (V), 1-iodopentane, others. F. petiolata headspace was characterized by DMS (22.2%), 6-methylhept-5-en-2-one (9.5%), C17 (9.1%), II (6.5%), compounds I-V. DMS (59.3%), C15 (14.5%), C17 (7.2%) and C19 (6.3%) dominated in P. oceanica headspace. Sesquiterpenes were found in D. dichotoma, predominantly germacrene D (28.3%) followed by other cadinenyl (abundant), muurolenyl and amorphenyl structures. Determined VOCs may be significant for chemosystematics and chemical communications in marine ecosystem. PMID:29738535

Aromatic compounds produced by Periconia atropurpurea, an endophytic fungus associated with Xylopia aromatica.

PubMed

Teles, Helder Lopes; Sordi, Renata; Silva, Geraldo Humberto; Castro-Gamboa, Ian; Bolzani, Vanderlan da Silva; Pfenning, Ludwig Heinrich; de Abreu, Lucas Magalhães; Costa-Neto, Claudio Miguel; Young, Maria Claudia Marx; Araújo, Angela Regina

2006-12-01

6,8-Dimethoxy-3-(2'-oxo-propyl)-coumarin (1) and 2,4-dihydroxy-6-[(1'E,3'E)-penta-1',3'-dienyl]-benzaldehyde (2), in addition to the known compound periconicin B (3), were isolated from the ethyl acetate extract of Periconia atropurpurea, an endophytic fungus obtained from the leaves of Xylopia aromatica, a native plant of the Brazilian Cerrado. Their chemical structures were assigned based on analyses of MS, 1D and 2D-NMR spectroscopic experiments. Biological analyses were performed using two mammalian cell lines, human cervix carcinoma (HeLa) and Chinese hamster ovary (CHO). The results showed that compound 1 had no effect when compared to the control group, which was treated with the vehicle (DMSO). Compound 2 was able to induce a slight increase in cell proliferation of HeLa (37% of increase) and CHO (38% of increase) cell lines. Analysis of compound 3 showed that it has potent cytotoxic activity against both cell lines, with an IC50 of 8.0 microM. Biological analyses using the phytopathogenic fungi Cladosporium sphaerospermum and C. cladosporioides revealed that also 2 showed potent antifungal activity compared to nystatin.

Analysis of residual products in triethylbenzylammonium chloride by HPLC. Study of the retention mechanism.

PubMed

Prieto-Blanco, M C; López-Mahía, P; Prada-Rodríguez, D

2006-04-01

The control of industrial products for minimization of their impact on the environment and human health requires the development of specific analysis methods. Information provided by these methods about toxic components, by-products, and other derivatives may also be useful to reduce the possible impact of industrial products. The studied compound in this paper, triethylbenzylammonium chloride (TEBA), is mainly used in industrial synthesis. This quaternary compound and its residual products coming from quaternization reaction (benzyl chloride, benzaldehyde, and benzyl alcohol) are analyzed by HPLC. The separation is based on control of the silanophilic contribution to TEBA retention because of the quaternary nature of this compound. The effect of the three buffers (sodium acetate, ammonium acetate, and sodium formate) and their concentrations in the chromatographic behavior of the quaternary compound is examined. The buffer cation and anion regulate TEBA retention. Also, the concentration of the quaternary compound is another parameter that had influence in some aspects of its chromatographic behavior (e.g., retention and symmetry). The proposed method is applied to TEBA synthesis along, with the formation and removal of impurities with the results compared with those obtained for the quaternary compound benzalkonium chloride.

Characterization of Botanical and Geographical Origin of Corsican “Spring” Honeys by Melissopalynological and Volatile Analysis

PubMed Central

Yang, Yin; Battesti, Marie-José; Costa, Jean; Paolini, Julien

2014-01-01

Pollen spectrum, physicochemical parameters and volatile fraction of Corsican “spring” honeys were investigated with the aim of developing a multidisciplinary method for the qualification of honeys in which nectar resources are under-represented in the pollen spectrum. Forty-one Corsican “spring” honeys were certified by melissopalynological analysis using directory and biogeographical origin of 50 representative taxa. Two groups of honeys were distinguished according to the botanical origin of samples: “clementine” honeys characterized by the association of cultivated species from oriental plain and other “spring” honeys dominated by wild herbaceous taxa from the ruderal and/or maquis area. The main compounds of the “spring” honey volatile fraction were phenylacetaldehyde, benzaldehyde and methyl-benzene. The volatile composition of “clementine” honeys was also characterized by three lilac aldehyde isomers. Statistical analysis of melissopalynological, physicochemical and volatile data showed that the presence of Citrus pollen in “clementine” honeys was positively correlated with the amount of linalool derivatives and methyl anthranilate. Otherwise, the other “spring” honeys were characterized by complex nectariferous species associations and the content of phenylacetaldehyde and methyl syringate. PMID:28234308

Biochemical and Structural Basis for Controlling Chemical Modularity in Fungal Polyketide Biosynthesis

DOE PAGES

Winter, Jaclyn M.; Cascio, Duilio; Dietrich, David; ...

2015-07-14

Modular collaboration between iterative fungal polyketide synthases (IPKSs) is an important mechanism for generating structural diversity of polyketide natural products. Inter-PKS communication and substrate channeling are controlled in large by the starter unit acyl carrier protein transacylase (SAT) domain found in the accepting IPKS module. Here in this study, we reconstituted the modular biosynthesis of the benzaldehyde core of the chaetoviridin and chaetomugilin azaphilone natural products using the IPKSs CazF and CazM. Our studies revealed a critical role of CazM’s SAT domain in selectively transferring a highly reduced triketide product from CazF. In contrast, a more oxidized triketide that ismore » also produced by CazF and required in later stages of biosynthesis of the final product is not recognized by the SAT domain. The structural basis for the acyl unit selectivity was uncovered by the first X-ray structure of a fungal SAT domain, highlighted by a covalent hexanoyl thioester intermediate in the SAT active site. Finally, the crystal structure of SAT domain will enable protein engineering efforts aimed at mixing and matching different IPKS modules for the biosynthesis of new compounds.« less

Synthesis and Evaluation of In Vitro Antibacterial and Antitumor Activities of Novel N,N-Disubstituted Schiff Bases

PubMed Central

Luo, Heng; Xia, Yu-fen; Sun, Bao-fei; Huang, Li-rong; Wang, Xing-hui; Lou, Hua-yong; Zhu, Xu-hui

2017-01-01

To get inside the properties of N,N-disubstituted Schiff bases, we synthesized three high-yielding benzaldehyde Schiff bases. We used the reaction between salicylaldehyde and different diamine compounds, including diamine, ethanediamine, and o-phenylenediamine, determining the structure of obtained molecules by nuclear magnetic resonance spectroscopy and electrospray ionization mass spectroscopy. We thus evaluated the microbicidal and antitumor activity of these compounds, showing that salicylaldehyde-hydrazine hydrate Schiff base (compound 1a) significantly inhibited the growth of S. aureus; salicylaldehyde-o-phenylenediamine Schiff base (compound 1c) displayed a strong capability to inhibit the proliferation of leukemia cell lines K562 and HEL. Moreover, we observed that the antibacterial action of 1a might be associated with the regulation of the expression of key virulence genes in S. aureus. Compound 1c resulted in a strong apoptotic activity against leukemia cells, also affecting the cell cycle distribution. Overall, our novel N,N-disubstituted Schiff bases possess unique antibacterial or antitumor activities that exhibit the potent application prospect in prophylactic or therapeutic interventions, providing new insights for developing new antibacterial and anticancer chemical agents. PMID:28713593

Synthesis and biological evaluation of novel 6-hydroxy-benzo[d][1,3]oxathiol-2-one Schiff bases as potential anticancer agents.

PubMed

Chazin, Eliza de Lucas; Sanches, Paola de Souza; Lindgren, Eric Brazil; Vellasco Júnior, Walcimar Trindade; Pinto, Laine Celestino; Burbano, Rommel Mario Rodríguez; Yoneda, Julliane Diniz; Leal, Kátia Zaccur; Gomes, Claudia Regina Brandão; Wardell, James Lewis; Wardell, Solange Maria Silva Veloso; Montenegro, Raquel Carvalho; Vasconcelos, Thatyana Rocha Alves

2015-01-27

With the aim of discovering new anticancer agents, we have designed and synthesized novel 6-hydroxy-benzo[d][1,3]oxathiol-2-one Schiff bases. The synthesis started with the selective nitration at 5-position of 6-hydroxybenzo[d][1,3]oxathiol-2-one (1) leading to the nitro derivative 2. The nitro group of 2 was reduced to give the amino intermediate 3. Schiff bases 4a-r were obtained from coupling reactions between 3 and various benzaldehydes and heteroaromatic aldehydes. All the new compounds were fully identified and characterized by NMR (1H and 13C) and specifically for 4q by X-ray crystallography. The in vitro cytotoxicity of the compounds was evaluated against cancer cell lines (ACP-03, SKMEL-19 and HCT-116) by using MTT assay. Schiff bases 4b and 4o exhibited promising cytotoxicity against ACP-03 and SKMEL-19, respectively, with IC50 values lower than 5 μM. This class of compounds can be considered as a good starting point for the development of new lead molecules in the fight against cancer.

Comparative analysis of the volatile composition of honeys from Brazilian stingless bees by static headspace GC-MS.

PubMed

de Lima Morais da Silva, Patricia; de Lima, Liliane Schier; Caetano, Ísis Kaminski; Torres, Yohandra Reyes

2017-12-01

The volatile composition of honeys produced by eight species of stingless bees collected in three municipalities in the state of Paraná (Brazil) was compared by combining static headspace GC-MS and chemometrics methods. Forty-four compounds were identified using NIST library and linear retention index relative to n-alkanes (C 8 -C 40 ). Linalool derivatives were the most abundant peaks in most honeys regardless geographical or entomological origin. However, Principal Component Analysis discriminated honeys from different geographical origins considering their distinctive minor volatile components. Honey samples from Guaraqueçaba were characterized by the presence of hotrienol while those from Cambará showed epoxylinalol, benzaldehyde and TDN as minor discriminating compounds. Punctual species such as Borá showed similar fingerprints regardless geographical origin, with ethyl octanoate and ethyl decanoate as characteristic intense chromatographic peaks, which may suggest a specialized behavior for nectar collection. Discriminant Analysis allowed correct geographic discrimination of most honeys produced in the three spots tested. We concluded that volatile profile of stingless bee honeys can be used to attest authenticity related to regional origin of honeys. Copyright © 2017. Published by Elsevier Ltd.

Synthesis and reactions of nickel and palladium carbon-bound enolate complexes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Burkhardt, E.R.; Bergman, R.G.; Heathcock, C.H.

1990-01-01

Nickel and palladium carbon-bound enolates of the general formula {eta}{sup 5}-C{sub 5}R{sub 5}(Ph{sub 3}P)MCHR{prime}COR{double prime} (R = H, CH{sub 3}; R{prime} = H, CH{sub 3}; R{double prime} = t-Bu, Ph, O-t-Bu) were prepared. Cp{sup *}(Ph{sub 3}P)NiCH{sub 2}CO{sub 2}-t-Bu (1e) was characterized by X-ray diffraction. Compound 1e crystallizes in the monoclinic space group P2{sub 1}/n with unit-cell dimensions a = 13.6110 (20) {angstrom}, b = 12.7454 (13) {angstrom}, c = 17.8571 (23) {angstrom}, {beta} = 105.544 (11){degree}, Z = 4, observed data 4,091, R = 4.53%, and R{sub w} = 4.19%. Reactions of these nickel and palladium enolates with aldehydes andmore » other electrophilic reagents were examined. The nickel ketone enolates were shown to react with 2 equiv of benzaldehyde to deliver products resulting from a Tischtschenko-type oxidation/reduction process. Cp(Ph{sub 3}P)NiCH{sub 2}CO-t-Bu reacts with phosphines (L) to yield paramagnetic nickel(I) complexes of general formula Cp(L){sub 2}Ni.« less

Volatiles released from Vaccinium corymbosum were attractive to Aegorhinus superciliosus (Coleoptera: Curculionidae) in an olfactometric bioassay.

PubMed

Parra, Leonardo; Mutis, Ana; Ceballos, Ricardo; Lizama, Marcelo; Pardo, Fernando; Perich, Fernando; Quiroz, Andrés

2009-06-01

The objective of this study was to evaluate the role of host volatiles in the relationship between a blueberry plant Vaccinium corymbosum L. and the raspberry weevil Aegorhinus superciliosus (Guérin) (Coleoptera: Curculionidae), the principal pest of blueberry in the south of Chile. Volatiles from the aerial part of different phenological stages of the host were collected on Porapak Q and analyzed by coupled gas chromatography-mass spectrometry (GC-MS). Several chemical groups were identified including green leaf volatiles, aromatic compounds, and terpenes. The olfactometric responses of A. superciliosus toward different odor sources were studied in a four-arm olfactometer. Blueberry shoots at the phenological stages of fruit set, and blue-pink fruit color elicited the greatest behavioral responses from weevils. Five compounds (2-nonanone, eucalyptol, R- and S-limonene, and 4-ethyl benzaldehyde) elicited an attractant behavioral response from A. superciliosus. The results suggest the host location behavior of A. superciliosus could be mediated by volatiles derived from V. corymbosum. This work has identified a number of compounds with which it is possible to develop a lure for the principal pest of blueberry in southern Chile.

Enantioselectivity in CPA-catalyzed Friedel-Crafts reaction of indole and N-tosylimines: a challenge for guiding models.

PubMed

Simón, Luis

2018-03-28

Qualitative reaction models or predicting guides are a very useful outcome of theoretical investigations of organocatalytic reaction mechanism that allow forecasting of the degree and sense of the enantioselectivity of reactions involving novel substrates. However, application of these models can be unexpectedly challenging in reactions affected by a large number of conformations and potential control of the enantioselectivity by different reaction steps. The QM/MM study of the Friedel-Crafts reaction between indole and the N-tosylimide of benzaldehyde catalysed by different CPA reveals that the reaction consists of two CPA-assisted steps: the addition of the two reagents to yield a Wheland intermediate, and its re-aromatization. The relevance of the second step depends on the catalyst: it changes the sense of the expected stereoselectivity for a BINOP-derived CPA but is irrelevant in the reaction catalysed by a VAPOL-derived imidodiphosphoric acid catalyst. Although the relative energies of the TSs can be rationalized considering the steric interactions with the catalyst, the possibility of additional H-bonds, or the relative stability of the conformation of the reagents, predicting the enantioselectivity is not possible using qualitative guides.

Characterization of amygdalin-degrading Lactobacillus species.

PubMed

Menon, R; Munjal, N; Sturino, J M

2015-02-01

Cyanogenic glycosides are phytotoxic secondary metabolites produced by some crop plants. The aim of this study was to identify lactic acid bacteria (LAB) capable of catabolizing amygdalin, a model cyanogenic glycoside, for use in the biodetoxification of amygdalin-containing foods and feeds. Amygdalin-catabolizing lactobacilli were characterized using a combination of cultivation-dependent and molecular assays. Lactobacillus paraplantarum and Lactobacillus plantarum grew robustly on amygdalin (Amg(+)), while other LAB species typically failed to catabolize amygdalin (Amg(-)). Interestingly, high concentrations of amygdalin and two of its metabolic derivatives (mandelonitrile and benzaldehyde) inhibited the growth of Lact. plantarum RENO 0093. The differential regulation of genes tentatively involved in cyanohydrin metabolism illustrated that the metabolism of amygdalin- and glucose-grown cultures also differed significantly. Amygdalin fermentation was a relatively uncommon phenotype among the LAB and generally limited to strains from the Lact. plantarum group. Phenotype microarrays (PM) enabled strain-level discrimination between closely related strains within a species and suggested that phenotypic differences might affect niche specialization. Amygdalin-degrading lactobacilli with practical application in the biodetoxification of amygdalin were characterized. These strains show potential for use as starter cultures to improve the safety of foods and feeds. © 2014 The Society for Applied Microbiology.

A microfluidic device for open loop stripping of volatile organic compounds.

PubMed

Cvetković, Benjamin Z; Dittrich, Petra S

2013-03-01

The detection of volatile organic compounds is of great importance for assessing the quality of water. In this contribution, we describe a miniaturized stripping device that allows fast online detection of organic solvents in water. The core component is a glass microfluidic chip that facilitates the creation of an annular-flowing stream of water and nitrogen gas. Volatile compounds are transferred efficiently from the water into the gas phase along the microfluidic pathway at room temperature within less than 5 s. Before exiting the microchip, the liquid phase is separated from the enriched gas phase by incorporating side capillaries through which the hydrophilic water phase is withdrawn. The gas phase is conveniently collected at the outlet reservoir by tubing. Finally, a semiconductor gas sensor analyzes the concentration of (volatile) organic compounds in the nitrogen gas. The operation and use of the stripping device is demonstrated for the organic solvents THF, 1-propanol, toluene, ethylbenzene, benzaldehyde, and methanol. The mobile, inexpensive, and continuously operating system with liquid flow rates in the low range of microliters per minute can be connected to other detectors or implemented in chemical production line for process control.

New Approach to Evaluate the Antennal Response of an Adult Predator Insect to Different Volatile Chemical Compounds by using Electroantennogram Technique

NASA Astrophysics Data System (ADS)

Shonouda, Mourad L.

The antennal response of adult syrphid flies to selected plant volatile chemical compounds was investigated in the present study. The main chemical classes and their chemical compounds were aldehydes (nonanal and benzaldehyde), monoterpene-alcohols (linalool and alpha-terpineol), ketones (6-methyl-5-heptene-2-one and 2-undecanone), hydrocarbons (tetradecane) and benzoids (methyl salicylate). Electroantennogram (EAG) records showed that the syrphid antennae were strongly responded to linalool, 6-methyl-5-heptene-2-one and methyl salicylate even at low concentrations, in addition to the high dose concentration of nonanal comparably to the other chemical compounds. The antennae of old syrphid adults were more responsive and elicited higher levels of responses to all compounds rather than young syrphid adults. The antennal sensitivity may differ from one compound to another according to the sex. The difference in responses could be attributed to the sensitivity of olfactory receptors and/or the characterization of binding protein(s). The quality of biocontrol agent could be improved if the chemical interaction between beneficial natural enemies and the surrounding environment is intensively studied and we clearly understand the chemical ecology of each natural enemy.

New insights into aldol reactions of methyl isocyanoacetate catalyzed by heterogenized homogeneous catalysts

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ye, Rong; Zhao, Jie; Yuan, Bing

The Hayashi–Ito aldol reaction of methyl isocyanoacetate (MI) and benzaldehydes, a classic homogeneous Au(I)-catalyzed reaction, was studied with heterogenized homogeneous catalysts. Among dendrimer encapsulated nanoparticles (NPs) of Au, Pd, Rh, or Pt loaded in mesoporous supports and the homogeneous analogues, the Au NPs led to the highest yield and highest diastereoselectivity of products in toluene at room temperature. The Au catalyst was stable and was recycled for at least six runs without substantial deactivation. Moreover, larger pore sizes of the support and the use of a hydrophobic solvent led to a high selectivity for the trans diastereomer of the product.more » The activation energy is sensitive to neither the size of Au NPs nor the support. A linear Hammett plot was obtained with a positive slope, suggesting an increased electron density on the carbonyl carbon atom in the rate-limiting step. As a result, IR studies revealed a strong interaction between MI and the gold catalyst, supporting the proposed mechanism, in which rate-limiting step involves an electrophilic attack of the aldehyde on the enolate formed from the deprotonated MI.« less

Metal based new triazoles: Their synthesis, characterization and antibacterial/antifungal activities

NASA Astrophysics Data System (ADS)

Sumrra, Sajjad H.; Chohan, Zahid H.

2012-12-01

A series of new triazoles and their oxovanadium(IV) complexes have been synthesized, characterized and evaluated for antibacterial/antifungal properties. The new Schiff bases ligands (L1)-(L5) were prepared by the condensation reaction of 3,5-diamino-1,2,4-triazole with 2-hydroxy-1-naphthaldehyde, pyrrole-2-carboxaldehyde, pyridine-2-carboxaldehyde, 2-acetyl pyridine and 2-methoxy benzaldehyde. The structures of the ligands have been established on the basis of their physical, spectral (IR, 1H and 13C NMR and mass spectrometry) and elemental analytical data. The prepared ligands were used to synthesize their oxovanadium(IV) complexes (1)-(5) which were also characterized by their physical, spectral and analytical data and proposed to have a square pyramidal geometry. The ligands and their complexes were screened for in vitro antibacterial activity against six bacterial species such as, Escherichia coli, Shigella flexneri, Pseudomonas aeruginosa, Salmonella typhi, Staphylococcus aureus, and Bacillus subtilis and for in vitro antifungal activity against six fungal strains, Trichophyton longifusus, Candida albicans, Aspergillus flavus, Microsporum canis, Fusarium solani, and Candida glabrata. Cytotoxic nature of the compounds was also reported using brine shrimp bioassay method against Artemia salina.

Determination of starting materials, intermediates, and subsidiary colors in the color additive Food Red No. 106 (Sulforhodamine B) using high-performance liquid chromatography.

PubMed

Tatebe, Chiye; Ohtsuki, Takashi; Fujita, Tsuyoshi; Nishiyama, Koji; Itoh, Sumio; Sugimoto, Naoki; Kubota, Hiroki; Tada, Atsuko; Sato, Kyoko; Akiyama, Hiroshi

2017-12-15

The main subsidiary color of structure in Food Red No. 106 (R106) was identified to be a desethyl derivative (R106-SubA). High-performance liquid chromatography (HPLC) was performed for the quantitative determination of benzaldehyde-2,4-disulfonic acid, N,N-diethyl-m-aminophenol, leuco acid, pyrone acid, R106-SubA, etc. in R106. An ammonium acetate solution (20mM) and acetonitrile:water (7:3) were used to stabilize the retention time of the HPLC analytes. The linearity of the calibration curves was in the range of 0.05-10μg/mL, with good correlation coefficients (R 2 >0.9983). The recoveries of impurities at levels 0.1%, 0.5% and 1% ranged from 94.2% to 106.6% with relative standard deviations of 0.1%-1.0%. While surveying commercial R106, the amounts obtained by area% determination were similar to those obtained by the calibration-curve determination. The area% determination by HPLC for the determinations of impurities in R106 is a simple and reliable method and can be applied in routine analysis. Copyright © 2017 Elsevier Ltd. All rights reserved.

Expedient synthesis of C-aryl carbohydrates by consecutive biocatalytic benzoin and aldol reactions.

PubMed

Hernández, Karel; Parella, Teodor; Joglar, Jesús; Bujons, Jordi; Pohl, Martina; Clapés, Pere

2015-02-16

The introduction of aromatic residues connected by a C-C bond into the non-reducing end of carbohydrates is highly significant for the development of innovative structures with improved binding affinity and selectivity (e.g., C-aril-sLex). In this work, an expedient asymmetric "de novo" synthetic route to new aryl carbohydrate derivatives based on two sequential stereoselectively biocatalytic carboligation reactions is presented. First, the benzoin reaction of aromatic aldehydes to dimethoxyacetaldehyde is conducted, catalyzed by benzaldehyde lyase from Pseudomonas fluorescens biovar I. Then, the α-hydroxyketones formed are reduced by using NaBH4 yielding the anti diol. After acetal hydrolysis, the aldol addition of dihydroxyacetone, hydroxyacetone, or glycolaldehyde catalyzed by the stereocomplementary D-fructose-6-phosphate aldolase and L-rhamnulose-1-phosphate aldolase is performed. Both aldolases accept unphosphorylated donor substrates, avoiding the need of handling the phosphate group that the dihydroxyacetone phosphate-dependent aldolases require. In this way, 6-C-aryl-L-sorbose, 6-C-aryl-L-fructose, 6-C-aryl-L-tagatose, and 5-C-aryl-L-xylose derivatives are prepared by using this methodology. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

In-tube extraction for the determination of the main volatile compounds in Physalis peruviana L.

PubMed

Kupska, Magdalena; Jeleń, Henryk H

2017-01-01

An analytical procedure based on in-tube extraction followed by gas chromatography with mass spectrometry has been developed for the analysis of 24 of the main volatile components in cape gooseberry (Physalis peruviana L.) samples. According to their chemical structure, the compounds were organized into different groups: one hydrocarbon, one aldehyde, four alcohols, four esters, and 14 monoterpenes. By single-factor experiments, incubation temperature, incubation time, extraction volume, extraction strokes, extraction speed, desorption temperature, and desorption speed were determined as 60°C, 20 min, 1000 μL, 20, 50:50 μL/s, 280°C, 100 μL/s, respectively. Quantitative analysis using authentic standards and external calibration curves was performed. The limit of detection and limit of quantification for the analytical procedure were calculated. Results shown the benzaldehyde, ethyl butanoate, 2-methyl-1-butanol, 1-hexanol, 1-butanol, α-terpineol, and terpinen-4-ol were the most abundant volatile compounds in analyzed fruits (68.6-585 μg/kg). The obtained data may contribute to qualify cape gooseberry to the group of superfruits and, therefore, increase its popularity. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

United States Department of Agriculture-Agricultural Research Service research on natural products for pest management.

PubMed

Duke, Stephen O; Baerson, Scott R; Dayan, Franck E; Rimando, Agnes M; Scheffler, Brian E; Tellez, Mario R; Wedge, David E; Schrader, Kevin K; Akey, David H; Arthur, Frank H; De Lucca, Anthony J; Gibson, Donna M; Harrison, Howard F; Peterson, Joseph K; Gealy, David R; Tworkoski, Thomas; Wilson, Charles L; Morris, J Brad

2003-01-01

Recent research of the Agricultural Research Service of USDA on the use of natural products to manage pests is summarized. Studies of the use of both phytochemicals and diatomaceous earth to manage insect pests are discussed. Chemically characterized compounds, such as a saponin from pepper (Capsicum frutescens L), benzaldehyde, chitosan and 2-deoxy-D-glucose are being studied as natural fungicides. Resin glycosides for pathogen resistance in sweet potato and residues of semi-tropical leguminous plants for nematode control are also under investigation. Bioassay-guided isolation of compounds with potential use as herbicides or herbicide leads is underway at several locations. New natural phytotoxin molecular target sites (asparagine synthetase and fructose-1,6-bisphosphate aldolase) have been discovered. Weed control in sweet potato and rice by allelopathy is under investigation. Molecular approaches to enhance allelopathy in sorghum are also being undertaken. The genes for polyketide synthases involved in production of pesticidal polyketide compounds in fungi are found to provide clues for pesticide discovery. Gene expression profiles in response to fungicides and herbicides are being generated as tools to understand more fully the mode of action and to rapidly determine the molecular target site of new, natural fungicides and herbicides.

Thermostable NADP+-Dependent Medium-Chain Alcohol Dehydrogenase from Acinetobacter sp. Strain M-1: Purification and Characterization and Gene Expression in Escherichia coli

PubMed Central

Tani, Akio; Sakai, Yasuyoshi; Ishige, Takeru; Kato, Nobuo

2000-01-01

NADPH-dependent alkylaldehyde reducing enzyme, which was greatly induced by n-hexadecane, from Acinetobacter sp. strain M-1 was purified and characterized. The purified enzyme had molecular masses of 40 kDa as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and 160 kDa as determined by gel filtration chromatography. The enzyme, which was shown to be highly thermostable, was most active toward n-heptanal and could use n-alkylaldehydes ranging from C2 to C14 and several substituted benzaldehydes, including the industrially important compounds cinnamyl aldehyde and anisaldehyde, as substrates. The alrA gene coding for this enzyme was cloned, and its nucleotide sequence was determined. The deduced amino acid sequence encoded by the alrA gene exhibited homology to the amino acid sequences of zinc-containing alcohol dehydrogenases from various sources. The gene could be highly expressed in Escherichia coli, and the product was purified to homogeneity by simpler procedures from the recombinant than from the original host. Our results show that this enzyme can be used for industrial bioconversion of useful alcohols and aldehydes. PMID:11097895

New insights into aldol reactions of methyl isocyanoacetate catalyzed by heterogenized homogeneous catalysts

DOE PAGES

Ye, Rong; Zhao, Jie; Yuan, Bing; ...

2016-12-14

The Hayashi–Ito aldol reaction of methyl isocyanoacetate (MI) and benzaldehydes, a classic homogeneous Au(I)-catalyzed reaction, was studied with heterogenized homogeneous catalysts. Among dendrimer encapsulated nanoparticles (NPs) of Au, Pd, Rh, or Pt loaded in mesoporous supports and the homogeneous analogues, the Au NPs led to the highest yield and highest diastereoselectivity of products in toluene at room temperature. The Au catalyst was stable and was recycled for at least six runs without substantial deactivation. Moreover, larger pore sizes of the support and the use of a hydrophobic solvent led to a high selectivity for the trans diastereomer of the product.more » The activation energy is sensitive to neither the size of Au NPs nor the support. A linear Hammett plot was obtained with a positive slope, suggesting an increased electron density on the carbonyl carbon atom in the rate-limiting step. As a result, IR studies revealed a strong interaction between MI and the gold catalyst, supporting the proposed mechanism, in which rate-limiting step involves an electrophilic attack of the aldehyde on the enolate formed from the deprotonated MI.« less

Characteristics of Planetary Candidates Observed by Kepler. II. Analysis of the First Four Months of Data

NASA Astrophysics Data System (ADS)

Borucki, William J.; Koch, David G.; Basri, Gibor; Batalha, Natalie; Brown, Timothy M.; Bryson, Stephen T.; Caldwell, Douglas; Christensen-Dalsgaard, Jørgen; Cochran, William D.; DeVore, Edna; Dunham, Edward W.; Gautier, Thomas N., III; Geary, John C.; Gilliland, Ronald; Gould, Alan; Howell, Steve B.; Jenkins, Jon M.; Latham, David W.; Lissauer, Jack J.; Marcy, Geoffrey W.; Rowe, Jason; Sasselov, Dimitar; Boss, Alan; Charbonneau, David; Ciardi, David; Doyle, Laurance; Dupree, Andrea K.; Ford, Eric B.; Fortney, Jonathan; Holman, Matthew J.; Seager, Sara; Steffen, Jason H.; Tarter, Jill; Welsh, William F.; Allen, Christopher; Buchhave, Lars A.; Christiansen, Jessie L.; Clarke, Bruce D.; Das, Santanu; Désert, Jean-Michel; Endl, Michael; Fabrycky, Daniel; Fressin, Francois; Haas, Michael; Horch, Elliott; Howard, Andrew; Isaacson, Howard; Kjeldsen, Hans; Kolodziejczak, Jeffery; Kulesa, Craig; Li, Jie; Lucas, Philip W.; Machalek, Pavel; McCarthy, Donald; MacQueen, Phillip; Meibom, Søren; Miquel, Thibaut; Prsa, Andrej; Quinn, Samuel N.; Quintana, Elisa V.; Ragozzine, Darin; Sherry, William; Shporer, Avi; Tenenbaum, Peter; Torres, Guillermo; Twicken, Joseph D.; Van Cleve, Jeffrey; Walkowicz, Lucianne; Witteborn, Fred C.; Still, Martin

2011-07-01

On 2011 February 1 the Kepler mission released data for 156,453 stars observed from the beginning of the science observations on 2009 May 2 through September 16. There are 1235 planetary candidates with transit-like signatures detected in this period. These are associated with 997 host stars. Distributions of the characteristics of the planetary candidates are separated into five class sizes: 68 candidates of approximately Earth-size (R p < 1.25 R ⊕), 288 super-Earth-size (1.25 R ⊕ <= R p < 2 R ⊕), 662 Neptune-size (2 R ⊕ <= R p < 6 R ⊕), 165 Jupiter-size (6 R ⊕ <= R p < 15 R ⊕), and 19 up to twice the size of Jupiter (15 R ⊕ <= R p < 22 R ⊕). In the temperature range appropriate for the habitable zone, 54 candidates are found with sizes ranging from Earth-size to larger than that of Jupiter. Six are less than twice the size of the Earth. Over 74% of the planetary candidates are smaller than Neptune. The observed number versus size distribution of planetary candidates increases to a peak at two to three times the Earth-size and then declines inversely proportional to the area of the candidate. Our current best estimates of the intrinsic frequencies of planetary candidates, after correcting for geometric and sensitivity biases, are 5% for Earth-size candidates, 8% for super-Earth-size candidates, 18% for Neptune-size candidates, 2% for Jupiter-size candidates, and 0.1% for very large candidates; a total of 0.34 candidates per star. Multi-candidate, transiting systems are frequent; 17% of the host stars have multi-candidate systems, and 34% of all the candidates are part of multi-candidate systems.

Relationship between candidate communication ability and oral certification examination scores.

PubMed

Lunz, Mary E; Bashook, Philip G

2008-12-01

Structured case-based oral examinations are widely used in medical certifying examinations in the USA. These orals assess the candidate's decision-making skills using real or realistic patient cases. Frequently mentioned but not empirically evaluated is the potential bias introduced by the candidate's communication ability. This study aimed to assess the relationship between candidate communication ability and medical certification oral examination scores. Non-doctor communication observers rated a random sample of 90 candidates on communication ability during a medical oral certification examination. The multi-facet Rasch model was used to analyse the communication survey and the oral examination data. The multi-facet model accounts for observer and examiner severity bias. anova was used to measure differences in communication ability between passing and failing candidates and candidates grouped by level of communication ability. Pearson's correlations were used to compare candidate communication ability and oral certification examination performance. Candidate separation reliability values for the communication survey and the oral examination were 0.85 and 0.97, respectively, suggesting accurate candidate measurement. The correlation between communication scores and oral examination scores was 0.10. No significant difference was found between passing and failing candidates for measured communication ability. When candidates were grouped by high, moderate and low communication ability, there was no significant difference in their oral certification examination performance. Candidates' communication ability has little relationship to candidate performance on high-stakes, case-based oral examinations. Examiners for this certifying examination focused on assessing candidate decision-making ability and were not influenced by candidate communication ability.

Candidate marketing takes the guessing game out of choosing employers.

PubMed

Russell, Judith; Havel, Stacey

2010-01-01

Candidate marketing builds a foundation for relationships between employers and potential employees. Additionally, candidate marketing differentiates organizations in the marketplace. Organizations using candidate marketing to communicate the employer brand can expect a higher quality of candidates, and new employees are better prepared for the work environment and culture. Today, organizations can use a variety of integrated tools and techniques to communicate and build relationships with candidates. Candidate marketing demonstrates an organization's willingness towards transparency, and ability to invite open conversations between candidates and members of the organizations.

Advising Doctorate Candidates and Candidates' Views during the Dissertation Process

ERIC Educational Resources Information Center

Hilliard, Ann T.

2013-01-01

In order to provide candidates with effective advisement, it is important for the advisor to continue to practice positive professional relationships and provide relevant academic support to candidates. The advisor should work closely with other faculty members and need to listen to the voices of candidates to ensure candidates' success. What…

Candidal colonization, strain diversity, and antifungal susceptibility among adult diabetic patients.

PubMed

Al-Attas, Safia A; Amro, Soliman O

2010-01-01

Candidal colonization in diabetics is a matter of debate. The aim of this study is to investigate oral candidal colonization, strain diversity, antifungal susceptibility, and the influence of local and systemic host factors on candidal colonization in adult diabetics. We conducted a case-control study that compared 150 diabetics (49 type 1, 101 type 2) with 50 healthy controls. Two salivary samples were collected, using the oral rinse sampling method: one for salivary flow rate and pH determination, and the other for candidal colonization assessment. The candidal isolates were identified and tested in vitro for antifungal susceptibility using the commercial kit, Candifast. The relationship between specific host factors and candidal colonization was also investigated. Diabetics had a higher candidal carriage rate compared to controls, but not density. Candida albicans was the most frequently isolated species, but diabetics had a variety of other candidal species present. None of the control samples were resistant to any tested antifungal, while the diabetic samples had differing resistances to azole antifungals. Although there was a significant positive correlation between glycemic control and candidal colonization in type 2 diabetics, there was a negative correlation between salivary pH and candidal carriage in the controls versus density in type 2 diabetics. Diabetic patients not only had a higher candidal carriage rate, but also a variety of candidal species that were resistant to azole antifungals. Oral candidal colonization was significantly associated with glycemic control, type of diabetes, and salivary pH.

Analysis of swing voter in the Indonesian election of 2014 presidential candidates using Twitter data

NASA Astrophysics Data System (ADS)

Alfarisy, Muhammad Salman; Putra, Rizki M.; Liong, The Houw; Purqon, Acep

2015-09-01

Ahead of the 2014 elections would be interesting to predict which candidate will hold the highest authority in the Republic of Indonesia. Entering the 2014 presidential election there is no infidelity tendency of voters who initially settled on a party or a candidate then choose another party or candidate in the next election. Changes in the tendency to make the condition of society in a state that has not been to given the choice of a candidate is commonly called swing voters. On this occasion, an examination of the swing voters who use social media twitter. By utilizing the advanced search facility to collect data from the response of tweeps (twitter users) on the twitter to Indonesian presidential candidate. The data will be used to describe how much the popularity of a candidate among tweeps, knowing the candidates who have the largest positive response and negative response, as well as the growing popularity of the candidate. The data is expected to predict the RI presidential candidate in 2014.

32 CFR 901.6 - Candidate fitness test requirement.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 32 National Defense 6 2013-07-01 2013-07-01 false Candidate fitness test requirement. 901.6... Requirements § 901.6 Candidate fitness test requirement. Before being offered an appointment, candidates must take a Candidate Fitness Test (CFT) which consists of exercises designed to measure muscular strength...

32 CFR 901.6 - Candidate fitness test requirement.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 32 National Defense 6 2014-07-01 2014-07-01 false Candidate fitness test requirement. 901.6... Requirements § 901.6 Candidate fitness test requirement. Before being offered an appointment, candidates must take a Candidate Fitness Test (CFT) which consists of exercises designed to measure muscular strength...

32 CFR 901.6 - Candidate fitness test requirement.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 32 National Defense 6 2012-07-01 2012-07-01 false Candidate fitness test requirement. 901.6... Requirements § 901.6 Candidate fitness test requirement. Before being offered an appointment, candidates must take a Candidate Fitness Test (CFT) which consists of exercises designed to measure muscular strength...

32 CFR 901.6 - Candidate fitness test requirement.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 32 National Defense 6 2011-07-01 2011-07-01 false Candidate fitness test requirement. 901.6... Requirements § 901.6 Candidate fitness test requirement. Before being offered an appointment, candidates must take a Candidate Fitness Test (CFT) which consists of exercises designed to measure muscular strength...

32 CFR 901.6 - Candidate fitness test requirement.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 32 National Defense 6 2010-07-01 2010-07-01 false Candidate fitness test requirement. 901.6... Requirements § 901.6 Candidate fitness test requirement. Before being offered an appointment, candidates must take a Candidate Fitness Test (CFT) which consists of exercises designed to measure muscular strength...

22 CFR 11.8 - Travel expenses of candidates.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Travel expenses of candidates. 11.8 Section 11... Travel expenses of candidates. The travel and other personal expenses of candidates incurred in... Department may issue round-trip invitational travel orders to bring candidates to Washington at Government...

A Research on the Burnout and the Teaching Profession Attitudes of Teacher Candidates

ERIC Educational Resources Information Center

Kadi, Aysegül; Beytekin, Osman Ferda; Arslan, Hasan

2015-01-01

Purpose of this study is to examine burnout and teaching profession attitudes of teacher candidates. Research was conducted with 287 teacher candidates. By the findings; burnout and teaching profession attitudes of teacher candidates don't differ according to their gender. Burnout of teacher candidates differs according to their graduation status…

75 FR 69221 - Endangered and Threatened Wildlife and Plants; Review of Native Species That Are Candidates for...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-11-10

...In this Candidate Notice of Review (CNOR), we, the U.S. Fish and Wildlife Service (Service), present an updated list of plant and animal species native to the United States that we regard as candidates for or have proposed for addition to the Lists of Endangered and Threatened Wildlife and Plants under the Endangered Species Act of 1973, as amended. Identification of candidate species can assist environmental planning efforts by providing advance notice of potential listings, allowing landowners and resource managers to alleviate threats and thereby possibly remove the need to list species as endangered or threatened. Even if we subsequently list a candidate species, the early notice provided here could result in more options for species management and recovery by prompting candidate conservation measures to alleviate threats to the species. The CNOR summarizes the status and threats that we evaluated in order to determine that species qualify as candidates and to assign a listing priority number (LPN) to each species or to determine that species should be removed from candidate status. Additional material that we relied on is available in the Species Assessment and Listing Priority Assignment Forms (species assessment forms, previously called candidate forms) for each candidate species. Overall, this CNOR recognizes five new candidates, changes the LPN for four candidates, and removes one species from candidate status. Combined with other decisions for individual species that were published separately from this CNOR in the past year, the current number of species that are candidates for listing is 251. This document also includes our findings on resubmitted petitions and describes our progress in revising the Lists of Endangered and Threatened Wildlife and Plants during the period October 1, 2009, through September 30, 2010. We request additional status information that may be available for the 251 candidate species identified in this CNOR.

275 Candidates and 149 Validated Planets Orbiting Bright Stars in K2 Campaigns 0–10

NASA Astrophysics Data System (ADS)

Mayo, Andrew W.; Vanderburg, Andrew; Latham, David W.; Bieryla, Allyson; Morton, Timothy D.; Buchhave, Lars A.; Dressing, Courtney D.; Beichman, Charles; Berlind, Perry; Calkins, Michael L.; Ciardi, David R.; Crossfield, Ian J. M.; Esquerdo, Gilbert A.; Everett, Mark E.; Gonzales, Erica J.; Hirsch, Lea A.; Horch, Elliott P.; Howard, Andrew W.; Howell, Steve B.; Livingston, John; Patel, Rahul; Petigura, Erik A.; Schlieder, Joshua E.; Scott, Nicholas J.; Schumer, Clea F.; Sinukoff, Evan; Teske, Johanna; Winters, Jennifer G.

2018-03-01

Since 2014, NASA’s K2 mission has observed large portions of the ecliptic plane in search of transiting planets and has detected hundreds of planet candidates. With observations planned until at least early 2018, K2 will continue to identify more planet candidates. We present here 275 planet candidates observed during Campaigns 0–10 of the K2 mission that are orbiting stars brighter than 13 mag (in Kepler band) and for which we have obtained high-resolution spectra (R = 44,000). These candidates are analyzed using the vespa package in order to calculate their false-positive probabilities (FPP). We find that 149 candidates are validated with an FPP lower than 0.1%, 39 of which were previously only candidates and 56 of which were previously undetected. The processes of data reduction, candidate identification, and statistical validation are described, and the demographics of the candidates and newly validated planets are explored. We show tentative evidence of a gap in the planet radius distribution of our candidate sample. Comparing our sample to the Kepler candidate sample investigated by Fulton et al., we conclude that more planets are required to quantitatively confirm the gap with K2 candidates or validated planets. This work, in addition to increasing the population of validated K2 planets by nearly 50% and providing new targets for follow-up observations, will also serve as a framework for validating candidates from upcoming K2 campaigns and the Transiting Exoplanet Survey Satellite, expected to launch in 2018.

Using a New Crustal Thickness Model to Test Previous Candidate Lunar Basins and to Search for New Candidates

NASA Technical Reports Server (NTRS)

Meyer, H. M.; Frey, H. V.

2012-01-01

A new crustal thickness model was used to test the viability of 110 candidate large lunar basins previously identified using older topographic and crustal thickness data as well as photogeologic data. The new model was also used to search for new candidate lunar basins greater than 300 km in diameter. We eliminated 11 of 27 candidates previously identified in the older crustal thickness model, and found strong evidence for at least 8 new candidates.

Low-lying excited states by constrained DFT

NASA Astrophysics Data System (ADS)

Ramos, Pablo; Pavanello, Michele

2018-04-01

Exploiting the machinery of Constrained Density Functional Theory (CDFT), we propose a variational method for calculating low-lying excited states of molecular systems. We dub this method eXcited CDFT (XCDFT). Excited states are obtained by self-consistently constraining a user-defined population of electrons, Nc, in the virtual space of a reference set of occupied orbitals. By imposing this population to be Nc = 1.0, we computed the first excited state of 15 molecules from a test set. Our results show that XCDFT achieves an accuracy in the predicted excitation energy only slightly worse than linear-response time-dependent DFT (TDDFT), but without incurring into problems of variational collapse typical of the more commonly adopted ΔSCF method. In addition, we selected a few challenging processes to test the limits of applicability of XCDFT. We find that in contrast to TDDFT, XCDFT is capable of reproducing energy surfaces featuring conical intersections (azobenzene and H3) with correct topology and correct overall energetics also away from the intersection. Venturing to condensed-phase systems, XCDFT reproduces the TDDFT solvatochromic shift of benzaldehyde when it is embedded by a cluster of water molecules. Thus, we find XCDFT to be a competitive method among single-reference methods for computations of excited states in terms of time to solution, rate of convergence, and accuracy of the result.

Purification, cloning, functional expression and characterization of perakine reductase: the first example from the AKR enzyme family, extending the alkaloidal network of the plant Rauvolfia.

PubMed

Sun, Lianli; Ruppert, Martin; Sheludko, Yuri; Warzecha, Heribert; Zhao, Yu; Stöckigt, Joachim

2008-07-01

Perakine reductase (PR) catalyzes an NADPH-dependent step in a side-branch of the 10-step biosynthetic pathway of the alkaloid ajmaline. The enzyme was cloned by a "reverse-genetic" approach from cell suspension cultures of the plant Rauvolfia serpentina (Apocynaceae) and functionally expressed in Escherichia coli as the N-terminal His(6)-tagged protein. PR displays a broad substrate acceptance, converting 16 out of 28 tested compounds with reducible carbonyl function which belong to three substrate groups: benzaldehyde, cinnamic aldehyde derivatives and monoterpenoid indole alkaloids. The enzyme has an extraordinary selectivity in the group of alkaloids. Sequence alignments define PR as a new member of the aldo-keto reductase (AKR) super family, exhibiting the conserved catalytic tetrad Asp52, Tyr57, Lys84, His126. Site-directed mutagenesis of each of these functional residues to an alanine residue results in >97.8% loss of enzyme activity, in compounds of each substrate group. PR represents the first example of the large AKR-family which is involved in the biosynthesis of plant monoterpenoid indole alkaloids. In addition to a new esterase, PR significantly extends the Rauvolfia alkaloid network to the novel group of peraksine alkaloids.

Effects of irrigation regimes on fatty acid composition, antioxidant and antifungal properties of volatiles from fruits of Koroneiki cultivar grown under Tunisian conditions.

PubMed

Brahmi, Faten; Chehab, Hechmi; Flamini, Guido; Dhibi, Madiha; Issaoui, Manel; Mastouri, Maha; Hammami, Mohamed

2013-11-15

The olive tree is generally grown under rain-fed conditions. However, since the yield response to irrigation is great, even with low amounts of water, there is increasing interest in irrigated agriculture. The main goal of this study was, therefore, to investigate the effect of irrigation regimes on olive (Olea europaea L., cv. Koroneiki) obtained from an intensively-managed orchard in a semi-arid area with a Mediterranean climate in Tunisia. Different irrigation treatments 50% ETc, 75% ETc and 100% ETc were applied to the olive orchard. Accordingly, the effects of three irrigation regimes on volatile compounds, fatty acid composition and biological activities of Koroneiki cultivar were studied. The total profile of the volatile constituents of all samples revealed the predominance of 3-ethenylpyridine (from 14.9-19.6%), phenylethyl alcool (from 7.8-19.2%) and benzaldehyde (from 9.0 to 13.8%). During watering level treatments studied, the major fatty acids were oleic, palmitic and linoleic. Antioxidant activity of the fresh fruit volatiles cultivated at a watering level of 100% ETc was higher than that obtained under 50 and 75% Etc. The results of antifungal activity showed that the fruits volatiles of the three irrigation treatments had varying degrees of growth inhibition against the microorganisms tested.

Reversible 1,2-Addition of Water To Form a Nucleophilic Mn(I) Hydroxide Complex: A Thermodynamic and Reactivity Study

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tondreau, Aaron M.; Michalczyk, Ryszard; Boncella, James M.

( iPrPN HP)Mn(CO) 2(OH) (2; iPrPN HP = HN{CH 2CH 2(P iPr 2)} 2) was formed from the reversible 1,2-addition of water to ( iPrPNP)Mn(CO) 2 (1; iPrPNP = the deprotonated, amide form of the ligand, –N{CH 2CH 2(P iPr 2)} 2). This reversible reaction was probed via variable-temperature NMR experiments, and the energetics of the 1,2-addition/elimination was found to be slightly exothermic (-0.8 kcal/mol). The corresponding manganese hydroxide was found to react with aldehydes, yielding the corresponding manganese carboxylate complexes ( iPrPN HP)Mn(CO) 2(CO 2R), where R = H, methyl, phenyl. While no reaction between 1 and neat benzaldehydemore » was observed, in the presence of water, conversion to the corresponding manganese-bound benzoate with formation of H 2 was observed. The catalytic oxidation of benzaldehyde by water without additives was unsuccessful due to strong product inhibition, with the manganese benzoate formed under a variety of reaction conditions. Upon addition of base, a catalytic cycle for the conversion of aldehyde to carboxylate and hydrogen can be devised.« less

Installing heterobimetallic cobalt–aluminum single sites on a metal organic framework support

DOE PAGES

Thompson, Anthony B.; Pahls, Dale R.; Bernales, Varinia; ...

2016-08-22

Here, a heterobimetallic cobalt-aluminum complex was immobilized onto the metal organic framework NU-1000 using a simple solution-based deposition procedure. Characterization data are consistent with a maximum loading of a single Co-Al complex per Zr 6 node of NU-1000. Furthermore, the data support that the Co-Al bimetallic complex is evenly distributed throughout the NU-1000 particle, binds covalently to the Zr6 nodes, and occupies the NU-1000 apertures with the shortest internode distances (~8.5 Å). Heating the anchored Co-Al complex on NU-1000 at 300 °C for 1 h in air completely removes the organic ligand of the complex without affecting the structural integritymore » of the MOF support. We propose that a Co-Al oxide cluster is formed in place of the anchored complex in NU-1000 during heating. Collectively, the results suggest that well-defined heterobimetallic complexes can be effective precursors for installing two different metals simultaneously onto a MOF support. The CoAl-functionalized NU-1000 samples catalyze the oxidation of benzyl alcohol to benzaldehyde with tert-butyl hydroperoxide as a stoichiometric oxidant. Density functional theory calculations were performed to elucidate the detailed structures of the Co-Al active sites on the Zr 6-nodes, and a Co-mediated catalytic mechanism is proposed.« less

Molecular Targeted Approaches to Cancer Therapy and Prevention Using Chalcones

PubMed Central

Jandial, Danielle D.; Blair, Christopher A.; Zhang, Saiyang; Krill, Lauren S.; Zhang, Yan-Bing; Zi, Xiaolin

2014-01-01

There is an emerging paradigm shift in oncology that seeks to emphasize molecularly targeted approaches for cancer prevention and therapy. Chalcones (1,3-diphenyl-2-propen-1-ones), naturally-occurring compounds with widespread distribution in spices, tea, beer, fruits and vegetables, consist of open-chain flavonoids in which the two aromatic rings are joined by a three-carbon α, β-unsaturated carbonyl system. Due to their structural diversity, relative ease of chemical manipulation and reaction of α, β-unsaturated carbonyl moiety with cysteine residues in proteins, some lead chalcones from both natural products and synthesis have been identified in a variety of screening assays for modulating important pathways or molecular targets in cancers. These pathways and targets that are affected by chalcones include MDM2/p53, tubulin, proteasome, NF-kappa B, TRIAL/death receptors and mitochondria mediated apoptotic pathways, cell cycle, STAT3, AP-1, NRF2, AR, ER, PPAR-γ and β-catenin/Wnt. Compared to current cancer targeted therapeutic drugs, chalcones have the advantages of being inexpensive, easily available and less toxic; the ease of synthesis of chalcones from substituted benzaldehydes and acetophenones also makes them an attractive drug scaffold. Therefore, this review is focused on molecular targets of chalcones and their potential implications in cancer prevention and therapy. PMID:24467530

Study of the antibacterial and antifungal activities of synthetic benzyl bromides, ketones, and corresponding chalcone derivatives.

PubMed

Shakhatreh, Muhamad Ali K; Al-Smadi, Mousa L; Khabour, Omar F; Shuaibu, Fatima A; Hussein, Emad I; Alzoubi, Karem H

2016-01-01

Several applications of chalcones and their derivatives encouraged researchers to increase their synthesis as an alternative for the treatment of pathogenic bacterial and fungal infections. In the present study, chalcone derivatives were synthesized through cross aldol condensation reaction between 4-( N , N -dimethylamino)benzaldehyde and multiarm aromatic ketones. The multiarm aromatic ketones were synthesized through nucleophilic substitution reaction between 4-hydroxy acetophenone and benzyl bromides. The benzyl bromides, multiarm aromatic ketones, and corresponding chalcone derivatives were evaluated for their activities against eleven clinical pathogenic Gram-positive, Gram-negative bacteria, and three pathogenic fungi by the disk diffusion method. The minimum inhibitory concentration was determined by the microbroth dilution technique. The results of the present study demonstrated that benzyl bromide derivatives have strong antibacterial and antifungal properties as compared to synthetic chalcone derivatives and ketones. Benzyl bromides (1a and 1c) showed high ester activity against Gram-positive bacteria and fungi but moderate activity against Gram-negative bacteria. Therefore, these compounds may be considered as good antibacterial and antifungal drug discovery. However, substituted ketones (2a-b) as well as chalcone derivatives (3a-c) showed no activity against all the tested strains except for ketone (2c), which showed moderate activity against Candida albicans .

Study of the antibacterial and antifungal activities of synthetic benzyl bromides, ketones, and corresponding chalcone derivatives

PubMed Central

Shakhatreh, Muhamad Ali K; Al-Smadi, Mousa L; Khabour, Omar F; Shuaibu, Fatima A; Hussein, Emad I; Alzoubi, Karem H

2016-01-01

Several applications of chalcones and their derivatives encouraged researchers to increase their synthesis as an alternative for the treatment of pathogenic bacterial and fungal infections. In the present study, chalcone derivatives were synthesized through cross aldol condensation reaction between 4-(N,N-dimethylamino)benzaldehyde and multiarm aromatic ketones. The multiarm aromatic ketones were synthesized through nucleophilic substitution reaction between 4-hydroxy acetophenone and benzyl bromides. The benzyl bromides, multiarm aromatic ketones, and corresponding chalcone derivatives were evaluated for their activities against eleven clinical pathogenic Gram-positive, Gram-negative bacteria, and three pathogenic fungi by the disk diffusion method. The minimum inhibitory concentration was determined by the microbroth dilution technique. The results of the present study demonstrated that benzyl bromide derivatives have strong antibacterial and antifungal properties as compared to synthetic chalcone derivatives and ketones. Benzyl bromides (1a and 1c) showed high ester activity against Gram-positive bacteria and fungi but moderate activity against Gram-negative bacteria. Therefore, these compounds may be considered as good antibacterial and antifungal drug discovery. However, substituted ketones (2a–b) as well as chalcone derivatives (3a–c) showed no activity against all the tested strains except for ketone (2c), which showed moderate activity against Candida albicans. PMID:27877017

New fluorescent azo-Schiff base Cu(II) and Zn(II) metal chelates; spectral, structural, electrochemical, photoluminescence and computational studies

NASA Astrophysics Data System (ADS)

Purtas, Fatih; Sayin, Koray; Ceyhan, Gokhan; Kose, Muhammet; Kurtoglu, Mukerrem

2017-06-01

A new Schiff base containing azo chromophore group obtained by condensation of 2-hydroxy-4-[(E)-phenyldiazenyl]benzaldehyde with 3,4-dimethylaniline (HL) are used for the syntheses of new copper(II) and zinc(II) chelates, [Cu(L)2], and [Zn(L)2], and characterized by physico-chemical and spectroscopic methods such as 1H and 13C NMR, IR, UV.-Vis. and elemental analyses. The solid state structure of the ligand was characterized by single crystal X-ray diffraction study. X-ray diffraction data was then used to calculate the harmonic oscillator model of aromaticity (HOMA) indexes for the rings so as to investigate of enol-imine and keto-amine tautomeric forms in the solid state. The phenol ring C10-C15 shows a considerable deviation from the aromaticity with HOMA value of 0.837 suggesting the shift towards the keto-amine tautomeric form in the solid state. The analytical data show that the metal to ligand ratio in the chelates was found to be 1:2. Theoretical calculations of the possible isomers of the ligand and two metal complexes are performed by using B3LYP method. Electrochemical and photoluminescence properties of the synthesized azo-Schiff bases were also investigated.

Sources of fine organic aerosol. 2. Noncatalyst and catalyst-equipped automobiles and heavy-duty diesel trucks

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rogge, W.F.; Hildemann, L.M.; Mazurek, M.A.

Gasoline- and diesel-powered vehicles are known to contribute appreciable amounts of inhalable fine particulate matter to the atmosphere in urban areas. Internal combustion engines burning gasoline and diesel fuel contribute more than 21% of the primary fine particulate organic carbon emitted to the Los Angeles atmosphere. In the present study, particulate (d[sub p] [le] 2 [mu]m) exhaust emissions from six noncatalyst automobiles, seven catalyst-equipped automobiles, and two heavy-duty diesel trucks are examined by gas chromatography/mass spectrometry. The purposes of this study are as follows: (a) to search for conservative marker compounds suitable for tracing the presence of vehicular particulate exhaustmore » emissions in the urban atmosphere, (b) to compile quantitative source profiles, and (c) to study the contributions of fine organic particulate vehicular exhaust to the Los Angeles atmosphere. More than 100 organic compounds are quantified, including n-alkanes, n-alkanoic acids, benzoic acids, benzaldehydes, PAH, oxy-PAH, steranes, pentacyclic triterpanes, azanaphthalenes, and others. Although fossil fuel markers such as steranes and pentacyclic triterpanes can be emitted from other sources, it can be shown that their ambient concentrations measured in the Los Angeles atmosphere are attributable mainly to vehicular exhaust emissions. 102 refs., 9 figs., 6 tabs.« less

Enzyme-Regulated Fast Self-Healing of a Pillararene-Based Hydrogel.

PubMed

Zhang, Xin; Xu, Jiayun; Lang, Chao; Qiao, Shanpeng; An, Guo; Fan, Xiaotong; Zhao, Linlu; Hou, Chunxi; Liu, Junqiu

2017-06-12

Self-healing, one of the exciting properties of materials, is frequently used to repair the damage of biological and artificial systems. Here we have used enzymatic catalysis approaches to develop a fast self-healing hydrogel, which has been constructed by dynamic aldimine cross-linking of pillar[5]arene-derivant and dialdehyde-functionalized PEG followed by encapsulation of glucose oxidase (GOx) and catalase (CAT). In specific, the two hydroxyl groups at terminal of PEG 4000 are functionalized with benzaldehydes that can interact with amino-containing pillar[5]arene-derivant through dynamic aldimine cross-links, resulting in reversible dynamic hydrogels. Modulus analysis indicated that storage modulus (G') and loss modulus (G″) of the hydrogel increased obviously as the concentration of dialdehyde-functionalized PEG 4000 (DF-PEG 4000 ) increased or the pH values decreased. Once glucose oxidase (GOx) and catalase (CAT) are located, the hydrogel could be fast repaired, with self-healing efficiency up to 100%. Notably tensile test showed that the repair process of pillararene-based hydrogel can finish in several minutes upon enzyme catalysis, while it needed more than 24 h to achieve this recovery without enzymes. This enzyme-regulated self-healing hydrogel would hold promise for delivering drugs and for soft tissue regeneration in the future.

Structural and Kinetic Basis for Substrate Selectivity in Populus tremuloides Sinapyl Alcohol Dehydrogenase

PubMed Central

Bomati, Erin K.; Noel, Joseph P.

2005-01-01

We describe the three-dimensional structure of sinapyl alcohol dehydrogenase (SAD) from Populus tremuloides (aspen), a member of the NADP(H)-dependent dehydrogenase family that catalyzes the last reductive step in the formation of monolignols. The active site topology revealed by the crystal structure substantiates kinetic results indicating that SAD maintains highest specificity for the substrate sinapaldehyde. We also report substantial substrate inhibition kinetics for the SAD-catalyzed reduction of hydroxycinnamaldehydes. Although SAD and classical cinnamyl alcohol dehydrogenases (CADs) catalyze the same reaction and share some sequence identity, the active site topology of SAD is strikingly different from that predicted for classical CADs. Kinetic analyses of wild-type SAD and several active site mutants demonstrate the complexity of defining determinants of substrate specificity in these enzymes. These results, along with a phylogenetic analysis, support the inclusion of SAD in a plant alcohol dehydrogenase subfamily that includes cinnamaldehyde and benzaldehyde dehydrogenases. We used the SAD three-dimensional structure to model several of these SAD-like enzymes, and although their active site topologies largely mirror that of SAD, we describe a correlation between substrate specificity and amino acid substitution patterns in their active sites. The SAD structure thus provides a framework for understanding substrate specificity in this family of enzymes and for engineering new enzyme specificities. PMID:15829607

Structural and kinetic basis for substrate selectivity in Populus tremuloides sinapyl alcohol dehydrogenase.

PubMed

Bomati, Erin K; Noel, Joseph P

2005-05-01

We describe the three-dimensional structure of sinapyl alcohol dehydrogenase (SAD) from Populus tremuloides (aspen), a member of the NADP(H)-dependent dehydrogenase family that catalyzes the last reductive step in the formation of monolignols. The active site topology revealed by the crystal structure substantiates kinetic results indicating that SAD maintains highest specificity for the substrate sinapaldehyde. We also report substantial substrate inhibition kinetics for the SAD-catalyzed reduction of hydroxycinnamaldehydes. Although SAD and classical cinnamyl alcohol dehydrogenases (CADs) catalyze the same reaction and share some sequence identity, the active site topology of SAD is strikingly different from that predicted for classical CADs. Kinetic analyses of wild-type SAD and several active site mutants demonstrate the complexity of defining determinants of substrate specificity in these enzymes. These results, along with a phylogenetic analysis, support the inclusion of SAD in a plant alcohol dehydrogenase subfamily that includes cinnamaldehyde and benzaldehyde dehydrogenases. We used the SAD three-dimensional structure to model several of these SAD-like enzymes, and although their active site topologies largely mirror that of SAD, we describe a correlation between substrate specificity and amino acid substitution patterns in their active sites. The SAD structure thus provides a framework for understanding substrate specificity in this family of enzymes and for engineering new enzyme specificities.

An olfactory shift is associated with male perfume differentiation and species divergence in orchid bees.

PubMed

Eltz, Thomas; Zimmermann, Yvonne; Pfeiffer, Carolin; Pech, Jorge Ramirez; Twele, Robert; Francke, Wittko; Quezada-Euan, J Javier G; Lunau, Klaus

2008-12-09

Saltational changes may underlie the diversification of pheromone communication systems in insects, which are normally under stabilizing selection favoring high specificity in signals and signal perception. In orchid bees (Euglossini), the production of male signals depends on the sense of smell: males collect complex blends of volatiles (perfumes) from their environment, which are later emitted as pheromone analogs at mating sites. We analyzed the behavioral and antennal response to perfume components in two male morphotypes of Euglossa cf. viridissima from Mexico, which differ in the number of mandibular teeth. Tridentate males collected 2-hydroxy-6-nona-1,3-dienyl-benzaldehyde (HNDB) as the dominant component of their perfume. In bidentate males, blends were broadly similar but lacked HNDB. Population genetic analysis revealed that tri- and bidentate males belong to two reproductively isolated lineages. Electroantennogram tests (EAG and GC-EAD) showed substantially lower antennal responses to HNDB in bidentate versus tridentate males, revealing for the first time a mechanism by which closely related species acquire different chemical compounds from their habitat. The component-specific differences in perfume perception and collection in males of two sibling species are in agreement with a saltational, olfaction-driven mode of signal perfume evolution. However, the response of females to the diverged signals remains unknown.

Mesoporous inorganic salts with crystal defects: unusual catalysts and catalyst supports† †Electronic supplementary information (ESI) available: Scheme S1 contains reaction equation, Fig. S1–S7 contain solubility test, XRD, SEM, TEM, micropore size distribution and reaction conversion. See DOI: 10.1039/c4sc03736g Click here for additional data file.

PubMed Central

Kang, Xinchen; Shang, Wenting; Zhu, Qinggong; Zhang, Jianling; Wu, Zhonghua; Li, Zhihong; Xing, Xueqing

2015-01-01

We proposed a strategy to synthesize mesoporous inorganic salt particles using the special properties of ionic liquid (IL) mixtures, and hollow mesoporous LaF3, NdF3, and YF3 particles were synthesized and characterized using different techniques. The size of the mesopores in the salt particles was about 4 nm, and the materials were full of crystal defects. The LaF3, NdF3 and YF3 particles were used as the catalysts for the cyanosilylation reaction of benzaldehyde using trimethylsilyl cyanide, and Ru/LaF3 and Ru/NdF3, in which Ru nanocatalysts were supported on the LaF3 and NdF3 particles with mesopores, were used to catalyze hydrogenations of benzene to cyclohexane and levulinic acid (LA) to γ-valerolactone (GVL). It was discovered that the activities of these catalysts were unprecedentedly high for these reactions. Detailed study showed that both the crystal defects and the mesopores in the salt particles played crucial roles for the extremely high catalytic activity. PMID:29308132

Small-Sized Mg–Al LDH Nanosheets Supported on Silica Aerogel with Large Pore Channels: Textural Properties and Basic Catalytic Performance after Activation

PubMed Central

Wang, Yusen; Wang, Xiaoxia; Feng, Xiaolan; Ye, Xiao; Fu, Jie

2018-01-01

Layered double hydroxides (LDHs) have been widely used as an important subset of solid base catalysts. However, developing low-cost, small-sized LDH nanoparticles with enhanced surface catalytic sites remains a challenge. In this work, silica aerogel (SA)-supported, small-sized Mg–Al LDH nanosheets were successfully prepared by one-pot coprecipitation of Mg and Al ions in an alkaline suspension of crushed silica aerogel. The supported LDH nanosheets were uniformly dispersed in the SA substrate with the smallest average radial diameter of 19.2 nm and the thinnest average thickness of 3.2 nm, both dimensions being significantly less than those of the vast majority of LDH nanoparticles reported. The SA/LDH composites also showed large pore volume (up to 1.3 cm3·g) and pore diameter (>9 nm), and therefore allow efficient access of reactants to the edge catalytic sites of LDH nanosheets. In a base-catalyzed Henry reaction of benzaldehyde with nitromethane, the SA/LDH catalysts showed high reactant conversions and favorable stability in 6 successive cycles of reactions. The low cost of the SA carrier and LDH precursors, easy preparation method, and excellent catalytic properties make these SA/LDH composites a competitive example of solid-base catalysts. PMID:29462941

Small-Sized Mg-Al LDH Nanosheets Supported on Silica Aerogel with Large Pore Channels: Textural Properties and Basic Catalytic Performance after Activation.

PubMed

Wang, Lijun; Wang, Yusen; Wang, Xiaoxia; Feng, Xiaolan; Ye, Xiao; Fu, Jie

2018-02-16

Layered double hydroxides (LDHs) have been widely used as an important subset of solid base catalysts. However, developing low-cost, small-sized LDH nanoparticles with enhanced surface catalytic sites remains a challenge. In this work, silica aerogel (SA)-supported, small-sized Mg-Al LDH nanosheets were successfully prepared by one-pot coprecipitation of Mg and Al ions in an alkaline suspension of crushed silica aerogel. The supported LDH nanosheets were uniformly dispersed in the SA substrate with the smallest average radial diameter of 19.2 nm and the thinnest average thickness of 3.2 nm, both dimensions being significantly less than those of the vast majority of LDH nanoparticles reported. The SA/LDH composites also showed large pore volume (up to 1.3 cm3·g) and pore diameter (>9 nm), and therefore allow efficient access of reactants to the edge catalytic sites of LDH nanosheets. In a base-catalyzed Henry reaction of benzaldehyde with nitromethane, the SA/LDH catalysts showed high reactant conversions and favorable stability in 6 successive cycles of reactions. The low cost of the SA carrier and LDH precursors, easy preparation method, and excellent catalytic properties make these SA/LDH composites a competitive example of solid-base catalysts.

Analytical and toxicological evaluation of flavor chemicals in electronic cigarette refill fluids.

PubMed

Behar, Rachel Z; Luo, Wentai; McWhirter, Kevin J; Pankow, James F; Talbot, Prue

2018-05-29

Thousands of electronic cigarette refill fluids are commercially available. The concentrations of nicotine and the solvents, but not the flavor chemicals, are often disclosed on product labels. The purpose of this study was to identify and quantify flavor chemicals in 39 commercial refill fluids that were previously evaluated for toxicity. Twelve flavor chemicals were identified with concentrations ≥1 mg/ml: cinnamaldehyde, menthol, benzyl alcohol, vanillin, eugenol, p-anisaldehyde, ethyl cinnamate, maltol, ethyl maltol, triacetin, benzaldehyde, and menthone. Transfer of these flavor chemicals into aerosols made at 3V and 5V was efficient (mean transfer = 98%). We produced lab-made refill fluids containing authentic standards of each flavor chemical and analyzed the toxicity of their aerosols produced at 3V and 5V using a tank Box Mod device. Over 50% of the refill fluids in our sample contained high concentrations of flavor chemicals that transferred efficiently to aerosols at concentrations that produce cytotoxicity. When tested with two types of human lung cells, the aerosols made at 5V were generally more toxic than those made at 3V. These data will be valuable for consumers, physicians, public health officials, and regulatory agencies when discussing potential health concerns relating to flavor chemicals in electronic cigarette products.

Surface properties and electromagnetic excitation of a piezoelectric gallium phosphate biosensor.

PubMed

Vasilescu, Alina; Ballantyne, Scott M; Cheran, Larisa-Emilia; Thompson, Michael

2005-02-01

The surface properties of GaPO4 have been studied by secondary ion mass spectrometry, X-ray photoelectron spectroscopy and electromagnetic acoustic wave excitation in order to explore the potential of this relatively new piezoelectric material as a biosensor. The X-ray photoelectron spectrum of the substrate shows a Ga-rich surface (Ga:P = 1.4), while the negative secondary ion mass spectrum is similar to that of other phosphates, with PO3- and PO2- being the main fragments derived from the substrate. Surface analysis reveals that the linker protein for biotinylated moieties, neutravidin, is both readily chemisorbed to bare gallium phosphate at pH 7.5 and attached to p-hydroxy benzaldehyde-treated devices, establishing the possibility to exploit the surface chemistry of the phosphate for the fabrication of an electrode-free acoustic wave biosensor. Preliminary results regarding the detection of the adsorption of neutravidin with an electromagnetic field-excited GaPO4 device incorporated in a FIA configuration showed comparable results with those obtained with a quartz-sensor equivalent. The frequency shift for the adsorbed protein layer at the device fundamental frequency was 200 Hz and the noise was routinely around 13 Hz. The possibility to use the electrodeless acoustic GaPO4 device at higher harmonics in the liquid phase has also been confirmed.

EOBII, a Gene Encoding a Flower-Specific Regulator of Phenylpropanoid Volatiles' Biosynthesis in Petunia[C][W

PubMed Central

Spitzer-Rimon, Ben; Marhevka, Elena; Barkai, Oren; Marton, Ira; Edelbaum, Orit; Masci, Tania; Prathapani, Naveen-Kumar; Shklarman, Elena; Ovadis, Marianna; Vainstein, Alexander

2010-01-01

Floral scent, which is determined by a complex mixture of low molecular weight volatile molecules, plays a major role in the plant's life cycle. Phenylpropanoid volatiles are the main determinants of floral scent in petunia (Petunia hybrida). A screen using virus-induced gene silencing for regulators of scent production in petunia flowers yielded a novel R2R3-MYB–like regulatory factor of phenylpropanoid volatile biosynthesis, EMISSION OF BENZENOIDS II (EOBII). This factor was localized to the nucleus and its expression was found to be flower specific and temporally and spatially associated with scent production/emission. Suppression of EOBII expression led to significant reduction in the levels of volatiles accumulating in and emitted by flowers, such as benzaldehyde, phenylethyl alcohol, benzylbenzoate, and isoeugenol. Up/downregulation of EOBII affected transcript levels of several biosynthetic floral scent-related genes encoding enzymes from the phenylpropanoid pathway that are directly involved in the production of these volatiles and enzymes from the shikimate pathway that determine substrate availability. Due to its coordinated wide-ranging effect on the production of floral volatiles, and its lack of effect on anthocyanin production, a central regulatory role is proposed for EOBII in the biosynthesis of phenylpropanoid volatiles. PMID:20543029

Transformations of Aromatic Compounds by Nitrosomonas europaea

PubMed Central

Keener, William K.; Arp, Daniel J.

1994-01-01

Benzene and a variety of substituted benzenes inhibited ammonia oxidation by intact cells of Nitrosomonas europaea. In most cases, the inhibition was accompanied by transformation of the aromatic compound to a more oxidized product or products. All products detected were aromatic, and substituents were often oxidized but were not separated from the benzene ring. Most transformations were enhanced by (NH4)2SO4 (12.5 mM) and were prevented by C2H2, a mechanism-based inactivator of ammonia monooxygenase (AMO). AMO catalyzed alkyl substituent hydroxylations, styrene epoxidation, ethylbenzene desaturation to styrene, and aniline oxidation to nitrobenzene (and unidentified products). Alkyl substituents were preferred oxidation sites, but the ring was also oxidized to produce phenolic compounds from benzene, ethylbenzene, halobenzenes, phenol, and nitrobenzene. No carboxylic acids were identified. Ethylbenzene was oxidized via styrene to two products common also to oxidation of styrene; production of styrene is suggestive of an electron transfer mechanism for AMO. Iodobenzene and 1,2-dichlorobenzene were oxidized slowly to halophenols; 1,4-dichlorobenzene was not transformed. No 2-halophenols were detected as products. Several hydroxymethyl (-CH2OH)-substituted aromatics and p-cresol were oxidized by C2H2-treated cells to the corresponding aldehydes, benzaldehyde was reduced to benzyl alcohol, and o-cresol and 2,5-dimethylphenol were not depleted. PMID:16349282

Reversible 1,2-Addition of Water To Form a Nucleophilic Mn(I) Hydroxide Complex: A Thermodynamic and Reactivity Study

DOE PAGES

Tondreau, Aaron M.; Michalczyk, Ryszard; Boncella, James M.

2017-09-20

( iPrPN HP)Mn(CO) 2(OH) (2; iPrPN HP = HN{CH 2CH 2(P iPr 2)} 2) was formed from the reversible 1,2-addition of water to ( iPrPNP)Mn(CO) 2 (1; iPrPNP = the deprotonated, amide form of the ligand, –N{CH 2CH 2(P iPr 2)} 2). This reversible reaction was probed via variable-temperature NMR experiments, and the energetics of the 1,2-addition/elimination was found to be slightly exothermic (-0.8 kcal/mol). The corresponding manganese hydroxide was found to react with aldehydes, yielding the corresponding manganese carboxylate complexes ( iPrPN HP)Mn(CO) 2(CO 2R), where R = H, methyl, phenyl. While no reaction between 1 and neat benzaldehydemore » was observed, in the presence of water, conversion to the corresponding manganese-bound benzoate with formation of H 2 was observed. The catalytic oxidation of benzaldehyde by water without additives was unsuccessful due to strong product inhibition, with the manganese benzoate formed under a variety of reaction conditions. Upon addition of base, a catalytic cycle for the conversion of aldehyde to carboxylate and hydrogen can be devised.« less

47 CFR 64.804 - Rules governing the extension of unsecured credit to candidates or persons on behalf of such...

Code of Federal Regulations, 2010 CFR

2010-10-01

... credit to candidates or persons on behalf of such candidates for Federal office for interstate and... CARRIERS Extension of Unsecured Credit for Interstate and Foreign Communications Services to Candidates for Federal Office § 64.804 Rules governing the extension of unsecured credit to candidates or persons on...

Comparing What Teacher Candidates Know about Each Other: China and the United States

ERIC Educational Resources Information Center

Xu, Tingting; Byker, Erik Jon; Chen, Juan

2016-01-01

The purpose of this article is to compare teacher candidates' knowledge and perceptions about China and the United States. Using a survey research design, 91 Chinese teacher candidates and 96 teacher candidates from the United Sates participated. The survey findings indicated that, while both groups of teacher candidates had a basic level of…

Teachers Candidates' Reviews on Teacher Candidate Training System

ERIC Educational Resources Information Center

Altintas, Sedat; Görgen, Izzet

2017-01-01

In our country, as a result of the appointment in some different disciplines, nearly 30000 teacher candidates could be a part of education system. Also, a new revision has been completed on teacher candidate training and it has been put into action. Teacher candidates have been trained for six months after they have been appointed. These teachers…

The role of candidate evaluations in the 2014 European Parliament elections: Towards the personalization of voting behaviour?

PubMed Central

Gattermann, Katjana; De Vreese, Claes H

2017-01-01

We study the personalization of voting behaviour in European Parliament elections. We argue that information from the media is crucial for providing linkages between candidates and voters. Moreover, we contend that candidates can serve as information short-cuts given the complexity of European Union politics. We use a four-wave Dutch panel survey and a media study that enable us to link evaluations of lead candidates, party preferences, and vote choice to exposure to news about these candidates. We show, firstly, that exposure to candidate news is a strong explanatory factor for candidate recognition. Secondly, we find that candidate evaluations positively affect party choice, albeit mainly for those voters who tend to be politically aware. Our research has implications for debates about the European Union’s accountability deficit. PMID:29657555

The role of candidate evaluations in the 2014 European Parliament elections: Towards the personalization of voting behaviour?

PubMed

Gattermann, Katjana; De Vreese, Claes H

2017-09-01

We study the personalization of voting behaviour in European Parliament elections. We argue that information from the media is crucial for providing linkages between candidates and voters. Moreover, we contend that candidates can serve as information short-cuts given the complexity of European Union politics. We use a four-wave Dutch panel survey and a media study that enable us to link evaluations of lead candidates, party preferences, and vote choice to exposure to news about these candidates. We show, firstly, that exposure to candidate news is a strong explanatory factor for candidate recognition. Secondly, we find that candidate evaluations positively affect party choice, albeit mainly for those voters who tend to be politically aware. Our research has implications for debates about the European Union's accountability deficit.

Pilot study on the use of data mining to identify cochlear implant candidates.

PubMed

Grisel, Jedidiah J; Schafer, Erin; Lam, Anne; Griffin, Terry

2018-05-01

The goal of this pilot study was to determine the clinical utility of data-mining software that screens for cochlear implant (CI) candidacy. The Auditory Implant Initiative developed a software module that screens for CI candidates via integration with a software system (Noah 4) that serves as a depository for hearing test data. To identify candidates, patient audiograms from one practice were exported into the screening module. Candidates were tracked to determine if any eventually underwent implantation. After loading 4836 audiograms from the Noah 4 system, the screening module identified 558 potential CI candidates. After reviewing the data for the potential candidates, 117 were targeted and invited to an educational event. Following the event, a total of six candidates were evaluated, and two were implanted. This objective approach to identifying candidates has the potential to address the gross underutilization of CIs by removing any bias or lack of knowledge regarding the management of severe to profound sensorineural hearing loss with CIs. The screening module was an effective tool for identifying potential CI candidates at one ENT practice. On a larger scale, the screening module has the potential to impact thousands of CI candidates worldwide.

Exploring intentions of physician-scientist trainees: factors influencing MD and MD/PhD interest in research careers.

PubMed

Kwan, Jennifer M; Daye, Dania; Schmidt, Mary Lou; Conlon, Claudia Morrissey; Kim, Hajwa; Gaonkar, Bilwaj; Payne, Aimee S; Riddle, Megan; Madera, Sharline; Adami, Alexander J; Winter, Kate Quinn

2017-07-11

Prior studies have described the career paths of physician-scientist candidates after graduation, but the factors that influence career choices at the candidate stage remain unclear. Additionally, previous work has focused on MD/PhDs, despite many physician-scientists being MDs. This study sought to identify career sector intentions, important factors in career selection, and experienced and predicted obstacles to career success that influence the career choices of MD candidates, MD candidates with research-intense career intentions (MD-RI), and MD/PhD candidates. A 70-question survey was administered to students at 5 academic medical centers with Medical Scientist Training Programs (MSTPs) and Clinical and Translational Science Awards (CTSA) from the NIH. Data were analyzed using bivariate or multivariate analyses. More MD/PhD and MD-RI candidates anticipated or had experienced obstacles related to balancing academic and family responsibilities and to balancing clinical, research, and education responsibilities, whereas more MD candidates indicated experienced and predicted obstacles related to loan repayment. MD/PhD candidates expressed higher interest in basic and translational research compared to MD-RI candidates, who indicated more interest in clinical research. Overall, MD-RI candidates displayed a profile distinct from both MD/PhD and MD candidates. MD/PhD and MD-RI candidates experience obstacles that influence their intentions to pursue academic medical careers from the earliest training stage, obstacles which differ from those of their MD peers. The differences between the aspirations of and challenges facing MD, MD-RI and MD/PhD candidates present opportunities for training programs to target curricula and support services to ensure the career development of successful physician-scientists.

Candidate genes for obesity-susceptibility show enriched association within a large genome-wide association study for BMI.

PubMed

Vimaleswaran, Karani S; Tachmazidou, Ioanna; Zhao, Jing Hua; Hirschhorn, Joel N; Dudbridge, Frank; Loos, Ruth J F

2012-10-15

Before the advent of genome-wide association studies (GWASs), hundreds of candidate genes for obesity-susceptibility had been identified through a variety of approaches. We examined whether those obesity candidate genes are enriched for associations with body mass index (BMI) compared with non-candidate genes by using data from a large-scale GWAS. A thorough literature search identified 547 candidate genes for obesity-susceptibility based on evidence from animal studies, Mendelian syndromes, linkage studies, genetic association studies and expression studies. Genomic regions were defined to include the genes ±10 kb of flanking sequence around candidate and non-candidate genes. We used summary statistics publicly available from the discovery stage of the genome-wide meta-analysis for BMI performed by the genetic investigation of anthropometric traits consortium in 123 564 individuals. Hypergeometric, rank tail-strength and gene-set enrichment analysis tests were used to test for the enrichment of association in candidate compared with non-candidate genes. The hypergeometric test of enrichment was not significant at the 5% P-value quantile (P = 0.35), but was nominally significant at the 25% quantile (P = 0.015). The rank tail-strength and gene-set enrichment tests were nominally significant for the full set of genes and borderline significant for the subset without SNPs at P < 10(-7). Taken together, the observed evidence for enrichment suggests that the candidate gene approach retains some value. However, the degree of enrichment is small despite the extensive number of candidate genes and the large sample size. Studies that focus on candidate genes have only slightly increased chances of detecting associations, and are likely to miss many true effects in non-candidate genes, at least for obesity-related traits.

78 FR 70103 - Endangered and Threatened Wildlife and Plants; Review of Native Species That are Candidates for...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-11-22

...In this Candidate Notice of Review (CNOR), we, the U.S. Fish and Wildlife Service (Service), present an updated list of plant and animal species native to the United States that we regard as candidates for or have proposed for addition to the Lists of Endangered and Threatened Wildlife and Plants under the Endangered Species Act of 1973, as amended. Identification of candidate species can assist environmental planning efforts by providing advance notice of potential listings, allowing landowners and resource managers to alleviate threats and thereby possibly remove the need to list species as endangered or threatened. Even if we subsequently list a candidate species, the early notice provided here could result in more options for species management and recovery by prompting candidate conservation measures to alleviate threats to the species. The CNOR summarizes the status and threats that we evaluated in order to determine that species qualify as candidates and to assign a listing priority number (LPN) to each species or to determine that species should be removed from candidate status. Additional material that we relied on is available in the Species Assessment and Listing Priority Assignment Forms (species assessment forms) for each candidate species. Overall, this CNOR recognizes no new candidates, changes the LPN for three candidates, and removes three species from candidate status. Combined with other decisions for individual species that were published separately from this CNOR in the past year, the current number of species that are candidates for listing is 146. This document also includes our findings on resubmitted petitions and describes our progress in revising the Lists of Endangered and Threatened Wildlife and Plants (Lists) during the period October 1, 2012, through September 30, 2013. We request additional status information that may be available for the 146 candidate species identified in this CNOR.

76 FR 66369 - Endangered and Threatened Wildlife and Plants; Review of Native Species That Are Candidates for...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-10-26

...In this Candidate Notice of Review (CNOR), we, the U.S. Fish and Wildlife Service (Service), present an updated list of plant and animal species native to the United States that we regard as candidates for or have proposed for addition to the Lists of Endangered and Threatened Wildlife and Plants under the Endangered Species Act of 1973, as amended. Identification of candidate species can assist environmental planning efforts by providing advance notice of potential listings, allowing landowners and resource managers to alleviate threats and thereby possibly remove the need to list species as endangered or threatened. Even if we subsequently list a candidate species, the early notice provided here could result in more options for species management and recovery by prompting candidate conservation measures to alleviate threats to the species. The CNOR summarizes the status and threats that we evaluated in order to determine that species qualify as candidates and to assign a listing priority number (LPN) to each species or to determine that species should be removed from candidate status. Additional material that we relied on is available in the Species Assessment and Listing Priority Assignment Forms (species assessment forms) for each candidate species. Overall, this CNOR recognizes three new candidates, changes the LPN for seven candidates, and removes three species from candidate status. Combined with other decisions for individual species that were published separately from this CNOR in the past year, the current number of species that are candidates for listing is 244. This document also includes our findings on resubmitted petitions and describes our progress in revising the Lists of Endangered and Threatened Wildlife and Plants (Lists) during the period October 1, 2010, through September 30, 2011. We request additional status information that may be available for the 244 candidate species identified in this CNOR.

Do heads of government age more quickly? Observational study comparing mortality between elected leaders and runners-up in national elections of 17 countries.

PubMed

Olenski, Andrew R; Abola, Matthew V; Jena, Anupam B

2015-12-14

To determine whether being elected to head of government is associated with accelerated mortality by studying survival differences between people elected to office and unelected runner-up candidates who never served. Observational study. Historical survival data on elected and runner-up candidates in parliamentary or presidential elections in Australia, Austria, Canada, Denmark, Finland, France, Germany, Greece, Ireland, Italy, New Zealand, Norway, Poland, Spain, Sweden, United Kingdom, and United States, from 1722 to 2015. Elected and runner-up political candidates. Observed number of years alive after each candidate's last election, relative to what would be expected for an average person of the same age and sex as the candidate during the year of the election, based on historical French and British life tables. Observed post-election life years were compared between elected candidates and runners-up, adjusting for life expectancy at time of election. A Cox proportional hazards model (adjusted for candidate's life expectancy at the time of election) considered years until death (or years until end of study period for those not yet deceased by 9 September 2015) for elected candidates versus runners-up. The sample included 540 candidates: 279 winners and 261 runners-up who never served. A total of 380 candidates were deceased by 9 September 2015. Candidates who served as a head of government lived 4.4 (95% confidence interval 2.1 to 6.6) fewer years after their last election than did candidates who never served (17.8 v 13.4 years after last election; adjusted difference 2.7 (0.6 to 4.8) years). In Cox proportional hazards analysis, which considered all candidates (alive or deceased), the mortality hazard for elected candidates relative to runners-up was 1.23 (1.00 to 1.52). Election to head of government is associated with a substantial increase in mortality risk compared with candidates in national elections who never served. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Presidential, But Not Prime Minister, Candidates With Lower Pitched Voices Stand a Better Chance of Winning the Election in Conservative Countries.

PubMed

Banai, Benjamin; Laustsen, Lasse; Banai, Irena Pavela; Bovan, Kosta

2018-01-01

Previous studies have shown that voters rely on sexually dimorphic traits that signal masculinity and dominance when they choose political leaders. For example, voters exert strong preferences for candidates with lower pitched voices because these candidates are perceived as stronger and more competent. Moreover, experimental studies demonstrate that conservative voters, more than liberals, prefer political candidates with traits that signal dominance, probably because conservatives are more likely to perceive the world as a threatening place and to be more attentive to dangerous and threatening contexts. In light of these findings, this study investigates whether country-level ideology influences the relationship between candidate voice pitch and electoral outcomes of real elections. Specifically, we collected voice pitch data for presidential and prime minister candidates, aggregate national ideology for the countries in which the candidates were nominated, and measures of electoral outcomes for 69 elections held across the world. In line with previous studies, we found that candidates with lower pitched voices received more votes and had greater likelihood of winning the elections. Furthermore, regression analysis revealed an interaction between candidate voice pitch, national ideology, and election type (presidential or parliamentary). That is, having a lower pitched voice was a particularly valuable asset for presidential candidates in conservative and right-leaning countries (in comparison to presidential candidates in liberal and left-leaning countries and parliamentary elections). We discuss the practical implications of these findings, and how they relate to existing research on candidates' voices, voting preferences, and democratic elections in general.

47 CFR 76.205 - Origination cablecasts by legally qualified candidates for public office; equal opportunities.

Code of Federal Regulations, 2010 CFR

2010-10-01

...) Bona fide news interview; (3) Bona fide news documentary (if the appearance of the candidate is... legally qualified candidate for the office in question. (d) Burden of proof. A candidate requesting equal...

47 CFR 76.205 - Origination cablecasts by legally qualified candidates for public office; equal opportunities.

Code of Federal Regulations, 2011 CFR

2011-10-01

...) Bona fide news interview; (3) Bona fide news documentary (if the appearance of the candidate is... legally qualified candidate for the office in question. (d) Burden of proof. A candidate requesting equal...

Examination of the Attitudes of Preschool Teacher Candidates and Teacher Candidates in Other Branches towards Scientific Research in Terms of Some Variables

ERIC Educational Resources Information Center

Ekici, Fatma Yasar

2017-01-01

The main objective of this study is to examine the attitudes of preschool teacher candidates and teacher candidates in other branches towards scientific research in terms of some variables. Survey method was used. The study group consists of 547 teacher candidates studying in education faculty of a private university in the spring term of…

ARCHITECTURE AND DYNAMICS OF KEPLER'S CANDIDATE MULTIPLE TRANSITING PLANET SYSTEMS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lissauer, Jack J.; Jenkins, Jon M.; Borucki, William J.

About one-third of the {approx}1200 transiting planet candidates detected in the first four months of Kepler data are members of multiple candidate systems. There are 115 target stars with two candidate transiting planets, 45 with three, 8 with four, and 1 each with five and six. We characterize the dynamical properties of these candidate multi-planet systems. The distribution of observed period ratios shows that the vast majority of candidate pairs are neither in nor near low-order mean-motion resonances. Nonetheless, there are small but statistically significant excesses of candidate pairs both in resonance and spaced slightly too far apart to bemore » in resonance, particularly near the 2:1 resonance. We find that virtually all candidate systems are stable, as tested by numerical integrations that assume a nominal mass-radius relationship. Several considerations strongly suggest that the vast majority of these multi-candidate systems are true planetary systems. Using the observed multiplicity frequencies, we find that a single population of planetary systems that matches the higher multiplicities underpredicts the number of singly transiting systems. We provide constraints on the true multiplicity and mutual inclination distribution of the multi-candidate systems, revealing a population of systems with multiple super-Earth-size and Neptune-size planets with low to moderate mutual inclinations.« less

Government instability shifts skin tone representations of and intentions to vote for political candidates.

PubMed

Stern, Chadly; Balcetis, Emily; Cole, Shana; West, Tessa V; Caruso, Eugene M

2016-01-01

Does government stability shift the way White and Black Americans represent and make voting decisions about political candidates? Participants judged how representative lightened, darkened, and unaltered photographs were of a racially ambiguous candidate ostensibly running for political office (Studies 1-3). When the governmental system was presented as stable, White participants who shared (vs. did not share) the candidate's political beliefs rated a lightened photo as more representative of the candidate, and Black participants who shared (vs. did not share) the candidate's political beliefs rated a darkened photo as more representative (Studies 1-3). However, under conditions of instability, both Whites and Blacks who shared (vs. did not share) the candidate's political beliefs rated a lightened photo as more representative (Study 3). Representations of (Studies 2 and 3) and actual differences in (Studies 4a and 4b) skin tone predicted intentions to vote for candidates, as a function of government stability and participants' race. Further evidence suggested that system stability shifted the motivations that guided voting decisions (Study 4a and 4b). When the system was stable, the motivation to enhance one's group predicted greater intentions to vote for lighter skinned candidates among Whites, and greater intentions to vote for darker skinned candidates among Blacks. When the system was unstable, however, lacking confidence in the sociopolitical system predicted intentions to vote for lighter skinned candidates among both Whites and Blacks. Implications for political leadership and social perception are discussed. (c) 2016 APA, all rights reserved).

Analysis of PGY-1 Pharmacy Resident Candidate Letters of Recommendation at an Academically Affiliated Residency Program.

PubMed

McLaughlin, Milena M; Masic, Dalila; Gettig, Jacob P

2018-04-01

Letters of recommendation (LORs) are a critical component for differentiating among similarly qualified pharmacy residency candidates. These letters contain information that is difficult to ascertain from curricula vitae and pharmacy school transcripts. LOR writers may use any words or phrases appropriate for each candidate as there is no set framework for LORs. The objective of this study was to characterize descriptive themes in postgraduate year 1 (PGY-1) pharmacy residency candidates' LORs and to examine which themes of PGY-1 pharmacy residency candidates' LORs are predictive of an interview invitation at an academically affiliated residency program. LORs for candidates from the Pharmacy Online Residency Centralized Application System (PhORCAS) from 2013 and 2014 for the Midwestern University PGY-1 Pharmacy Residency were analyzed. LOR characteristics and descriptive themes were collected. All scores for candidate characteristics and overall PhORCAS recommendation were also recorded. A total of 351 LORs for 111 candidates from 2013 (n = 47 candidates) and 2014 (n = 64 candidates) were analyzed; 36 (32.4%) total candidates were offered an interview. Themes that were identified as predictors of an interview included a higher median (interquartile range) number of standout words (3 words [1.3-4] vs 3.8 words [2.5-5.5], P < .01) and teaching references (3.7 words [2.7-6] vs 5.7 words [3.7-7.8], P = .01). For this residency program, standout words and teaching references were important when offering interviews.

Physical attractiveness, issue agreement, and assimilation effects in candidate appraisal.

PubMed

Schubert, James N; Curran, Margaret Ann; Strungaru, Carmen

2011-01-01

This study examines the cognitive and affective factors of candidate appraisal by manipulating candidate attractiveness and levels of issue agreement with voters. Drawing upon research in evolutionary psychology and cognitive neuroscience, this analysis proposes that automatic processing of physical appearance predisposes affective disposition toward more attractive candidates, thereby influencing cognitive processing of issue information. An experimental design presented attractive and unattractive candidates who were either liberal or conservative in a mock primary election. The data show strong partial effects for appearance on vote intention, an interaction between appearance and issue agreement, and a tendency for voters to assimilate the dissimilar views of attractive candidates. We argue that physical appearance is important in primary elections when the differences in issue positions and ideology between candidates is small.

Robo-AO Kepler Survey. IV. The Effect of Nearby Stars on 3857 Planetary Candidate Systems

NASA Astrophysics Data System (ADS)

Ziegler, Carl; Law, Nicholas M.; Baranec, Christoph; Riddle, Reed; Duev, Dmitry A.; Howard, Ward; Jensen-Clem, Rebecca; Kulkarni, S. R.; Morton, Tim; Salama, Maïssa

2018-04-01

We present the overall statistical results from the Robo-AO Kepler planetary candidate survey, comprising of 3857 high-angular resolution observations of planetary candidate systems with Robo-AO, an automated laser adaptive optics system. These observations reveal previously unknown nearby stars blended with the planetary candidate host stars that alter the derived planetary radii or may be the source of an astrophysical false positive transit signal. In the first three papers in the survey, we detected 440 nearby stars around 3313 planetary candidate host stars. In this paper, we present observations of 532 planetary candidate host stars, detecting 94 companions around 88 stars; 84 of these companions have not previously been observed in high resolution. We also report 50 more-widely separated companions near 715 targets previously observed by Robo-AO. We derive corrected planetary radius estimates for the 814 planetary candidates in systems with a detected nearby star. If planetary candidates are equally likely to orbit the primary or secondary star, the radius estimates for planetary candidates in systems with likely bound nearby stars increase by a factor of 1.54, on average. We find that 35 previously believed rocky planet candidates are likely not rocky due to the presence of nearby stars. From the combined data sets from the complete Robo-AO KOI survey, we find that 14.5 ± 0.5% of planetary candidate hosts have a nearby star with 4″, while 1.2% have two nearby stars, and 0.08% have three. We find that 16% of Earth-sized, 13% of Neptune-sized, 14% of Saturn-sized, and 19% of Jupiter-sized planet candidates have detected nearby stars.

CT colonography: influence of 3D viewing and polyp candidate features on interpretation with computer-aided detection.

PubMed

Shi, Rong; Schraedley-Desmond, Pamela; Napel, Sandy; Olcott, Eric W; Jeffrey, R Brooke; Yee, Judy; Zalis, Michael E; Margolis, Daniel; Paik, David S; Sherbondy, Anthony J; Sundaram, Padmavathi; Beaulieu, Christopher F

2006-06-01

To retrospectively determine if three-dimensional (3D) viewing improves radiologists' accuracy in classifying true-positive (TP) and false-positive (FP) polyp candidates identified with computer-aided detection (CAD) and to determine candidate polyp features that are associated with classification accuracy, with known polyps serving as the reference standard. Institutional review board approval and informed consent were obtained; this study was HIPAA compliant. Forty-seven computed tomographic (CT) colonography data sets were obtained in 26 men and 10 women (age range, 42-76 years). Four radiologists classified 705 polyp candidates (53 TP candidates, 652 FP candidates) identified with CAD; initially, only two-dimensional images were used, but these were later supplemented with 3D rendering. Another radiologist unblinded to colonoscopy findings characterized the features of each candidate, assessed colon distention and preparation, and defined the true nature of FP candidates. Receiver operating characteristic curves were used to compare readers' performance, and repeated-measures analysis of variance was used to test features that affect interpretation. Use of 3D viewing improved classification accuracy for three readers and increased the area under the receiver operating characteristic curve to 0.96-0.97 (P<.001). For TP candidates, maximum polyp width (P=.038), polyp height (P=.019), and preparation (P=.004) significantly affected accuracy. For FP candidates, colonic segment (P=.007), attenuation (P<.001), surface smoothness (P<.001), distention (P=.034), preparation (P<.001), and true nature of candidate lesions (P<.001) significantly affected accuracy. Use of 3D viewing increases reader accuracy in the classification of polyp candidates identified with CAD. Polyp size and examination quality are significantly associated with accuracy. Copyright (c) RSNA, 2006.

Questions and Answers for Transplant Candidates about Model for End-Stage Liver Disease (MELD) and Pediatric End-Stage ....

MedlinePlus

... first offered to local Status 1 candidates, then regional Status 1 candidates. The sequence of offers after ... would then be considered for local and then regional candidates with a MELD of 15 or higher. ...

11 CFR 9033.1 - Candidate and committee agreements.

Code of Federal Regulations, 2010 CFR

2010-01-01

... supporting documentation and other information that the Commission may request. (5) The candidate and the... other information that the Commission may request. If the candidate or the candidate's authorized...) that meet the requirements of 11 CFR 9033.12(b). Upon request, documentation explaining the computer...

11 CFR 9033.1 - Candidate and committee agreements.

Code of Federal Regulations, 2011 CFR

2011-01-01

... supporting documentation and other information that the Commission may request. (5) The candidate and the... other information that the Commission may request. If the candidate or the candidate's authorized...) that meet the requirements of 11 CFR 9033.12(b). Upon request, documentation explaining the computer...

Teacher Candidate Dispositions: Perspectives of Professional Expectations

ERIC Educational Resources Information Center

Wake, Donna; Bunn, Gary

2016-01-01

This study describes a programmatic effort to examine dispositions perceptions of teacher candidates entering the profession. Study participants included 114 master's level teaching candidates in their first semester of a nontraditional teacher education program. Teacher candidates scored themselves on a department disposition rubric designed to…

Optimization of Candidate Selection Using Naive Bayes: Case Study in Company X

NASA Astrophysics Data System (ADS)

Kadar, JA; Agustono, D.; Napitupulu, D.

2018-01-01

This research was conducted as a decision-making system, and an alternative solution to complete the candidate assessment for a particular position. The human resources (HR) section on company X is responsible and initiative in selecting candidates in accordance with the assessment of their superiors. Selection by using the method of filling out the manager’s assessment questionnaire on the candidate’s subordinate. Three (3) managers have been determined to assess the 11 candidates for subordinates. By using questionnaire of quality classification of human resources and formula naive bayes it will get result which finally grouped using criteria scale as final grouping. The HR department has also determined that what is received is that which meets criteria 5. The result is three (3) candidates who can be proposed as candidates for certain positions in company X, and have met all required calculations. Furthermore the candidate will be given to management as an alternative input data in the selection of candidates.

Rapid automatic keyword extraction for information retrieval and analysis

DOEpatents

Rose, Stuart J [Richland, WA; Cowley,; E, Wendy [Richland, WA; Crow, Vernon L [Richland, WA; Cramer, Nicholas O [Richland, WA

2012-03-06

Methods and systems for rapid automatic keyword extraction for information retrieval and analysis. Embodiments can include parsing words in an individual document by delimiters, stop words, or both in order to identify candidate keywords. Word scores for each word within the candidate keywords are then calculated based on a function of co-occurrence degree, co-occurrence frequency, or both. Based on a function of the word scores for words within the candidate keyword, a keyword score is calculated for each of the candidate keywords. A portion of the candidate keywords are then extracted as keywords based, at least in part, on the candidate keywords having the highest keyword scores.

Identity Functions and Empathetic Tendencies of Teacher Candidates

ERIC Educational Resources Information Center

Ay, Alpaslan; Kadi, Aysegul

2016-01-01

Objective of this research is to investigate identity functions and empathetic tendencies of teacher candidates. Sample consists of 232 teacher candidates in social studies teacher education. Survey model is preferred to investigate the difference between identity functions and empathetic tendencies of teacher candidates. And also correlational…

Planet Hunters: New Kepler Planet Candidates from Analysis of Quarter 2

NASA Astrophysics Data System (ADS)

Lintott, Chris J.; Schwamb, Megan E.; Barclay, Thomas; Sharzer, Charlie; Fischer, Debra A.; Brewer, John; Giguere, Matthew; Lynn, Stuart; Parrish, Michael; Batalha, Natalie; Bryson, Steve; Jenkins, Jon; Ragozzine, Darin; Rowe, Jason F.; Schwainski, Kevin; Gagliano, Robert; Gilardi, Joe; Jek, Kian J.; Pääkkönen, Jari-Pekka; Smits, Tjapko

2013-06-01

We present new planet candidates identified in NASA Kepler Quarter 2 public release data by volunteers engaged in the Planet Hunters citizen science project. The two candidates presented here survive checks for false positives, including examination of the pixel offset to constrain the possibility of a background eclipsing binary. The orbital periods of the planet candidates are 97.46 days (KIC 4552729) and 284.03 (KIC 10005758) days and the modeled planet radii are 5.3 and 3.8 R ⊕. The latter star has an additional known planet candidate with a radius of 5.05 R ⊕ and a period of 134.49 days, which was detected by the Kepler pipeline. The discovery of these candidates illustrates the value of massively distributed volunteer review of the Kepler database to recover candidates which were otherwise uncataloged. .

Identifying Individual Differences among Doctoral Candidates: A Framework for Understanding Problematic Candidature

ERIC Educational Resources Information Center

Cantwell, Robert H.; Scevak, Jill J.; Bourke, Sid; Holbrook, Allyson

2012-01-01

Understanding how candidates cope with the demands of PhD candidature is important for institutions, supervisors and candidates. Individual differences in affective and metacognitive disposition were explored in 263 PhD candidates from two Australian universities. Several questionnaires relating to affective and metacognitive beliefs were…

11 CFR 100.92 - Candidate debates.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 11 Federal Elections 1 2011-01-01 2011-01-01 false Candidate debates. 100.92 Section 100.92 Federal Elections FEDERAL ELECTION COMMISSION GENERAL SCOPE AND DEFINITIONS (2 U.S.C. 431) Exceptions to Contributions § 100.92 Candidate debates. Funds provided to defray costs incurred in staging candidate debates...

11 CFR 100.154 - Candidate debates.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 11 Federal Elections 1 2010-01-01 2010-01-01 false Candidate debates. 100.154 Section 100.154 Federal Elections FEDERAL ELECTION COMMISSION GENERAL SCOPE AND DEFINITIONS (2 U.S.C. 431) Exceptions to Expenditures § 100.154 Candidate debates. Funds used to defray costs incurred in staging candidate debates in...

11 CFR 110.13 - Candidate debates.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 11 Federal Elections 1 2010-01-01 2010-01-01 false Candidate debates. 110.13 Section 110.13... PROHIBITIONS § 110.13 Candidate debates. (a) Staging organizations. (1) Nonprofit organizations described in 26... political parties may stage candidate debates in accordance with this section and 11 CFR 114.4(f). (2...