Apparatus and method for production of methanethiol

DOEpatents

Agarwal, Pradeep K.; Linjewile, Temi M.; Hull, Ashley S.; Chen, Zumao

2006-02-07

A method for the production of methyl mercaptan is provided. The method comprises providing raw feed gases consisting of methane and hydrogen sulfide, introducing the raw feed gases into a non-thermal pulsed plasma corona reactor, and reacting the raw feed gases within the non-thermal pulsed plasma corona reactor with the reaction CH₄+H₂S.fwdarw.CH₃SH+H₂. An apparatus for the production of methyl mercaptan using a non-thermal pulsed plasma corona reactor is also provided.

Volatile sulphur compound levels and related factors in patients with chronic renal failure.

PubMed

Gulsahi, Ayse; Evirgen, Sehrazat; Öztaş, Bengi; Genç, Yasemin; Çetinel, Yasemin

2014-08-01

To analyse specific volatile sulphur compound(VSC) levels in a group of chronic renal failure (CRF) patients and determine the relationship between these VSC levels and organoleptic measurements, blood urea nitrogen (BUN) levels, dental and periodontal conditions, salivary flow rate, and tongue coating scores. One examiner performed organoleptic and VSC measurements on fifty patients with CRF before and after haemodialysis (HD) and controls. DMFT and CPITN indexes, tongue coating scores, salivary flow rates were measured. Comparisons were performed using the Mann-Whitney U, Wilcoxon signed-ranks, and chi-square tests. Spearman correlation coefficient was used to analyse correlations. Before HD, the mean dimethyl sulphide level was 1.04 ± 1.20 in the CRF patients and 0.51 ± 0.65 in controls, with a significant difference. The mean hydrogen sulphide, methyl mercaptan and dimethyl sulphide levels in CRF patients were 1.47 ± 3.04, 1.03 ± 1.85, and 1.04 ± 1.20, respectively, before HD; and 0.53 ± 1.65, 0.48 ± 1.27, and 0.56 ± 0.85, respectively, after HD; with the differences being significant. Methyl mercaptan levels increased with an increase in HD duration. Tongue coating and organoleptic measurements were significantly correlated with methyl mercaptan. Dimethyl sulphide is the main VSC in extraoral blood-borne halitosis; but methyl mercaptan may also contribute to this type of halitosis. A decreased salivary flow rate and an increased pH of the biofilm matrix may be a significant parameter for VSC levels in CRF patients. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Lap shear strength and healing capability of self-healing adhesive containing epoxy/mercaptan microcapsules

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

Ghazali, Habibah; Ye, Lin; Zhang, Ming-Qiu

The aim of this work is to develop a self-healing polymeric adhesive formulation with epoxy/mercaptan microcapsules. Epoxy/mercaptan microcapsules were dispersed into a commercialize two-part epoxy adhesive for developing self-healing epoxy adhesive. The influence of different content of microcapsules on the shear strength and healing capability of epoxy adhesive were investigated using single-lap-joints with average thickness of adhesive layer of about 180 µm. This self-healing adhesive was used in bonding of 5000 series aluminum alloys adherents after mechanical and alkaline cleaning surface treatment. The adhesion strength was measured and presented as function of microcapsules loading. The results indicated that the virgin lapmore » shear strength was increased by about 26% with addition of 3 wt% of self-healing microcapsules. 12% to 28% recovery of the shear strength is achieved after self-healing depending on the microcapsules content. Scanning electron microscopy was used to study fracture surface of the joints. The self-healing adhesives exhibit recovery of both cohesion and adhesion properties with room temperature healing.« less

Method of refining cracked oil by using metallic soaps. [desulfurization of cracked oils

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

Masakichi, M.; Marunouchi, K.K.; Yoshimura, T.

1937-04-13

The method of refining cracked oil consists in dissolving oil-soluble heavy metallic soap of oleic acid in a volatile organic solvent which will disperse homogeneously in cracked oil; pouring the solution thus obtained slowly into cracked oil to effect dispersion naturally and homogeneously at room temperature in the cracked oil. This process serves to react the mercaptans in the cracked oil with the heavy metallic soap by a double decomposition reaction and to precipitate the mercaptans as insoluble metallic salts. The remaining liquid is distilled to separate it from the remaining solvent.

Biotreatment of refinery spent-sulfidic caustic using an enrichment culture immobilized in a novel support matrix.

PubMed

Conner, J A; Beitle, R R; Duncan, K; Kolhatkar, R; Sublette, K L

2000-01-01

Sodium hydroxide solutions are used in petroleum refining to remove hydrogen sulfide (H2S) and mercaptans from various hydrocarbon streams. The resulting sulfide-laden waste stream is called spent-sulfidic caustic. An aerobic enrichment culture was previously developed using a gas mixture of H2S and methyl-mercaptan (MeSH) as the sole energy source. This culture has now been immobilized in a novel support matrix, DuPont BIO-SEP beads, and is used to bio-treat a refinery spent-sulfidic caustic containing both inorganic sulfide and mercaptans in a continuous flow, fluidized-bed column bioreactor. Complete oxidation of both inorganic and organic sulfur to sulfate was observed with no breakthrough of H2S and < 2 ppmv of MeSH produced in the bioreactor outlet gas. Excessive buildup of sulfate (> 12 g/L) in the bioreactor medium resulted in an upset condition evidenced by excessive MeSH breakthrough. Therefore, bioreactor performance was limited by the steady-state sulfate concentration. Further improvement in volumetric productivity of a bioreactor system based on this enrichment culture will be dependent on maintenance of sulfate concentrations below inhibitory levels.

Self-Assembled Mercaptan on Mesoporous Silica (SAMMS) technology of mercury removal and stabilization

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

Feng, Xiangdong; Liu, Jun; Fryxell, G.E.

1997-09-01

This paper explains the technology developed to produce Self-Assembled Mercaptan on Mesoporous Silica (SAMMS) for mercury removal from aqueous wastewater and from organic wastes. The characteristics of SAMMS materials, including physical characteristics and mercury loading, and its application for mercury removal and stabilization are discussed. Binding kinetics and binding speciations are reported. Preliminary cost estimates are provided for producing SAMMS materials and for mercury removal from wastewater. The characteristics of SAMMS in mercury separation were studied at PNNL using simulated aqueous tank wastes and actual tritiated pump oil wastes from Savannah River Site; preliminary results are outlined. 47 refs., 16more » figs., 16 tabs.« less

Ultrafast dynamics of self-assembled monolayers under shock compression: effects of molecular and substrate structure.

PubMed

Lagutchev, Alexei S; Patterson, James E; Huang, Wentao; Dlott, Dana D

2005-03-24

Laser-driven approximately 1 GPa shock waves are used to dynamically compress self-assembled monolayers (SAMs) consisting of octadecanethiol (ODT) on Au and Ag, and pentanedecanethiol (PDT) and benzyl mercaptan (BMT) on Au. The SAM response to <4 ps shock loading and approximately 25 ps shock unloading is monitored by vibrational sum-frequency generation spectroscopy (SFG), which is sensitive to the instantaneous tilt angle of the SAM terminal group relative to the surface normal. Arrival of the shock front causes SFG signal loss in all SAMs with a material time constant <3.5 ps. Thermal desorption and shock recovery experiments show that SAMs remain adsorbed on the substrate, so signal loss is attributed to shock tilting of the methyl or phenyl groups to angles near 90 degrees. When the shock unloads, PDT/Au returns elastically to its native structure whereas ODT/Au does not. ODT evidences a complicated viscoelastic response that arises from at least two conformers, one that remains kinetically trapped in a large-tilt-angle conformation for times >250 ps and one that relaxes in approximately 30 ps to a nearly upright conformation. Although the shock responses of PDT/Au, ODT/Ag, and BMT/Au are primarily elastic, a small portion of the molecules, 10-20%, evidence viscoelastic response, either becoming kinetically trapped in large-tilt states or by relaxing in approximately 30 ps back to the native structure. The implications of the observed large-amplitude monolayer dynamics for lubrication under extreme conditions of high strain rates are discussed briefly.

Understanding the interface of six-shell cuboctahedral and icosahedral palladium clusters on reduced graphene oxide: experimental and theoretical study.

PubMed

Gracia-Espino, Eduardo; Hu, Guangzhi; Shchukarev, Andrey; Wågberg, Thomas

2014-05-07

Studies on noble-metal-decorated carbon nanostructures are reported almost on a daily basis, but detailed studies on the nanoscale interactions for well-defined systems are very rare. Here we report a study of reduced graphene oxide (rGOx) homogeneously decorated with palladium (Pd) nanoclusters with well-defined shape and size (2.3 ± 0.3 nm). The rGOx was modified with benzyl mercaptan (BnSH) to improve the interaction with Pd clusters, and N,N-dimethylformamide was used as solvent and capping agent during the decoration process. The resulting Pd nanoparticles anchored to the rGOx-surface exhibit high crystallinity and are fully consistent with six-shell cuboctahedral and icosahedral clusters containing ~600 Pd atoms, where 45% of these are located at the surface. According to X-ray photoelectron spectroscopy analysis, the Pd clusters exhibit an oxidized surface forming a PdO(x) shell. Given the well-defined experimental system, as verified by electron microscopy data and theoretical simulations, we performed ab initio simulations using 10 functionalized graphenes (with vacancies or pyridine, amine, hydroxyl, carboxyl, or epoxy groups) to understand the adsorption process of BnSH, their further role in the Pd cluster formation, and the electronic properties of the graphene-nanoparticle hybrid system. Both the experimental and theoretical results suggest that Pd clusters interact with functionalized graphene by a sulfur bridge while the remaining Pd surface is oxidized. Our study is of significant importance for all work related to anchoring of nanoparticles on nanocarbon-based supports, which are used in a variety of applications.

21 CFR 172.515 - Synthetic flavoring substances and adjuvants.

Code of Federal Regulations, 2012 CFR

2012-04-01

...-hydroxyundecanoic acid γ-lactone; peach aldehyde; aldehyde C-14. Undecenal. 2-Undecanone; methyl nonyl ketone. 9.... Acetanisole; 4′-methoxyacetophenone. Acetophenone; methyl phenyl ketone. Allyl anthranilate. Allyl butyrate... ethyl ether. Benzyl formate. 3-Benzyl-4-heptanone; benzyl dipropyl ketone. Benzyl isobutyrate. Benzyl...

21 CFR 172.515 - Synthetic flavoring substances and adjuvants.

Code of Federal Regulations, 2013 CFR

2013-04-01

...-hydroxyundecanoic acid γ-lactone; peach aldehyde; aldehyde C-14. Undecenal. 2-Undecanone; methyl nonyl ketone. 9.... Acetanisole; 4′-methoxyacetophenone. Acetophenone; methyl phenyl ketone. Allyl anthranilate. Allyl butyrate... ethyl ether. Benzyl formate. 3-Benzyl-4-heptanone; benzyl dipropyl ketone. Benzyl isobutyrate. Benzyl...

21 CFR 172.515 - Synthetic flavoring substances and adjuvants.

Code of Federal Regulations, 2011 CFR

2011-04-01

...-hydroxyundecanoic acid γ-lactone; peach aldehyde; aldehyde C-14. Undecenal. 2-Undecanone; methyl nonyl ketone. 9.... Acetanisole; 4′-methoxyacetophenone. Acetophenone; methyl phenyl ketone. Allyl anthranilate. Allyl butyrate... ethyl ether. Benzyl formate. 3-Benzyl-4-heptanone; benzyl dipropyl ketone. Benzyl isobutyrate. Benzyl...

21 CFR 172.515 - Synthetic flavoring substances and adjuvants.

Code of Federal Regulations, 2010 CFR

2010-04-01

...-hydroxyundecanoic acid γ-lactone; peach aldehyde; aldehyde C-14. Undecenal. 2-Undecanone; methyl nonyl ketone. 9.... Acetanisole; 4′-methoxyacetophenone. Acetophenone; methyl phenyl ketone. Allyl anthranilate. Allyl butyrate... ethyl ether. Benzyl formate. 3-Benzyl-4-heptanone; benzyl dipropyl ketone. Benzyl isobutyrate. Benzyl...

Electrochromic device using mercaptans and organothiolate compounds

DOEpatents

Lampert, Carl M.; Ma, Yan-ping; Doeff, Marca M.; Visco, Steven

1995-01-01

An electrochromic cell is disclosed which comprises an electrochromic layer and a composite ion counter electrode for transporting ions. The counter electrode further comprises a polymer electrolyte material and an organosulfur material in which, in its discharged state, the organosulfur material is further comprised of a mercaptan or an organothiolate. In one preferred embodiment, both the electrochromic electrode and the counter electrode are transparent either to visible light or to the entire electromagnetic spectrum in both charged and discharged states. An electrochromic device is disclosed which comprises one or more electrochromic electrodes encased in glass or plastic plates on the inner surface of each of which is formed a transparent electrically conductive film. Electrical contacts, which are in electrical contact with the conductive films, facilitate external electrical connection.

Primerless RTV Silicone Sealants/Adhesives PP-1135

DTIC Science & Technology

2003-04-01

Ultem ®. Structural homology recommended benzyl alcohol as a candidate fragment that might fulfill these...value for benzyl alcohol . Qualitative experiments show that benzyl alcohol wets the surface of an Ultem sample, as do some of the other solvents...isopropanol and benzyl alcohol are very nearly equal, yet the modeling predicts that benzyl alcohol interacts more favorably with Ultem than

Degradation of ethyl mercaptan and its major intermediate diethyl disulfide by Pseudomonas sp. strain WL2.

PubMed

Wang, Xiangqian; Wu, Chao; Liu, Nan; Li, Sujing; Li, Wei; Chen, Jianmeng; Chen, Dongzhi

2015-04-01

A Pseudomonas sp. strain WL2 that is able to efficiently metabolize ethyl mercaptan (EM) into diethyl disulfide (DEDS) through enzymatic oxidation was isolated from the activated sludge of a pharmaceutical wastewater plant. One hundred percent removal of 113.5 mg L(-1) EM and 110.3 mg L(-1) DEDS were obtained within 14 and 32 h, respectively. A putative EM degradation pathway that involved the catabolism via DEDS was proposed, which indicated DEDS were further mineralized into carbon dioxide (CO2), bacterial cells, and sulfate (SO4 (2-)) through the transformation of element sulfur and ethyl aldehyde. Degradation kinetics for EM and DEDS with different initial concentrations by strain WL2 were evaluated using Haldane-Andrews model with maximum specific degradation rates of 3.13 and 1.33 g g(-1) h(-1), respectively, and maximum degradation rate constants of 0.522 and 0.175 h(-1) using pseudo-first-order kinetic model were obtained. Results obtained that aerobic degradation of EM by strain WL2 was more efficient than those from previous studies. Substrate range studies of strain WL2 demonstrated its ability to degrade several mercaptans, disulfides, aldehydes, and methanol. All the results obtained highlight the potential of strain WL2 for the use in the biodegradation of volatile organic sulfur compounds (VOSCs).

Friction behavior of 304 stainless steel of varying hardness lubricated with benzene and some benzyl structures

NASA Technical Reports Server (NTRS)

Buckley, D. H.

1974-01-01

The lubricating properties of some benzyl and benzene structures were determined by using 304 stainless steel surfaces strained to various hardness. Friction coefficients and wear track widths were measured with a Bowden-Leben type friction apparatus by using a pin-on-disk specimen configuration. Results obtained indicate that benzyl monosulfide, dibenzyl disulfide, and benzyl alcohol resulted in the lowest friction coefficients for 304 stainless steel, while benzyl ether provided the least surface protection and gave the highest friction. Strainhardening of the 304 stainless steel prior to sliding resulted in reduced friction in dry sliding. With benzyl monosulfide, dibenzyl disulfide, and benzyl alcohol changes in 304 stainless steel hardness had no effect upon friction behavior.

A molecular imprinted SPR biosensor for sensitive determination of citrinin in red yeast rice.

PubMed

Atar, Necip; Eren, Tanju; Yola, Mehmet Lütfi

2015-10-01

A novel and sensitive molecular imprinted surface plasmon resonance (SPR) biosensor was developed for selective determination of citrinin (CIT) in red yeast rice. Firstly, the gold surface of SPR chip was modified with allyl mercaptane. Then, CIT-imprinted poly(2-hydroxyethyl methacrylate-methacryloylamidoglutamic acid) (p(HEMA-MAGA)) film was generated on the gold surface modified with allyl mercaptane. The unmodified and imprinted surfaces were characterized by Fourier transform infrared (FTIR) spectroscopy, atomic force microscopy (AFM) and contact angle measurements. The linearity range and the detection limit were obtained as 0.005-1.0 ng/mL and 0.0017 ng/mL, respectively. The SPR biosensor was applied to determination of CIT in red yeast rice sample. Copyright © 2015 Elsevier Ltd. All rights reserved.

Electrochromic device using mercaptans and organothiolate compounds

DOEpatents

Lampert, C.M.; Ma, Y.P.; Doeff, M.M.; Visco, S.

1995-08-15

An electrochromic cell is disclosed which comprises an electrochromic layer and a composite ion counter electrode for transporting ions. The counter electrode further comprises a polymer electrolyte material and an organosulfur material in which, in its discharged state, the organosulfur material is further comprised of a mercaptan or an organothiolate. In one preferred embodiment, both the electrochromic electrode and the counter electrode are transparent either to visible light or to the entire electromagnetic spectrum in both charged and discharged states. An electrochromic device is disclosed which comprises one or more electrochromic electrodes encased in glass or plastic plates on the inner surface of each of which is formed a transparent electrically conductive film. Electrical contacts, which are in electrical contact with the conductive films, facilitate external electrical connection. 5 figs.

Theoretical Study on Sers of Wagging Vibrations of Benzyl Radical Adsorbed on Silver Electrodes

NASA Astrophysics Data System (ADS)

Wu, De-Yin; Chen, Yan-Li; Tian, Zhong-Qun

2016-06-01

Electrochemical surface-enhanced Raman spectroscopy (EC-SERS) has been used to characterize adsorbed species widely but reaction intermediates rarely on electrodes. In previous studies, the observed SERS signals were proposed from surface benzyl species due to the electrochemical reduction of benzyl chloride on silver electrode surfaces. In this work, we reinvestigated the vibrational assignments of benzyl chloride and benzyl radical as the reaction intermediate. On the basis of density functional theoretical (DFT) calculations and normal mode analysis, our systematical results provide more reasonable new assignments for both surface species. Further, we investigated adsorption configurations, binding energies, and vibrational frequency shifts of benzyl radical interacting with silver. Our calculated results show that the wagging vibration displays significant vibrational frequency shift, strong coupling with some intramolecular modes in the phenyl ring, and significant changes in intensity of Raman signals. The study also provides absolute Raman intensity in benzyl halides and discuss the enhancement effect mainly due to the binding interaction with respect to free benzyl radical.

Direct arylation/alkylation/magnesiation of benzyl alcohols in the presence of Grignard reagents via Ni-, Fe-, or Co-catalyzed sp3 C-O bond activation.

PubMed

Yu, Da-Gang; Wang, Xin; Zhu, Ru-Yi; Luo, Shuang; Zhang, Xiao-Bo; Wang, Bi-Qin; Wang, Lei; Shi, Zhang-Jie

2012-09-12

Direct application of benzyl alcohols (or their magnesium salts) as electrophiles in various reactions with Grignard reagents has been developed via transition metal-catalyzed sp(3) C-O bond activation. Ni complex was found to be an efficient catalyst for the first direct cross coupling of benzyl alcohols with aryl/alkyl Grignard reagents, while Fe, Co, or Ni catalysts could promote the unprecedented conversion of benzyl alcohols to benzyl Grignard reagents in the presence of (n)hexylMgCl. These methods offer straightforward pathways to transform benzyl alcohols into a variety of functionalities.

Ultrafast shock compression of self-assembled monolayers: a molecular picture.

PubMed

Patterson, James E; Dlott, Dana D

2005-03-24

Simulations of self-assembled monolayers (SAMs) are performed to interpret experimental measurements of ultrafast approximately 1 GPa (volume compression deltaV approximately 0.1) planar shock compression dynamics probed by vibrational sum-frequency generation (SFG) spectroscopy (Lagutchev, A. S.; Patterson, J. E.; Huang, W.; Dlott, D. D. J. Phys. Chem. B 2005, 109, XXXX). The SAMs investigated are octadecanethiol (ODT) and pentadecanethiol (PDT) on Au(111) and Ag(111) substrates, and benzyl mercaptan (BMT) on Au(111). In the alkane SAMs, SFG is sensitive to the instantaneous orientation of the terminal methyl; in BMT it is sensitive to the phenyl orientation. Computed structures of alkane SAMs are in good agreement with experiment. In alkanes, the energies of gauche defects increase with increasing number and depth below the methyl plane, with the exception of ODT/Au where both single and double gauche defects at the two uppermost dihedrals have similar energies. Simulations of isothermal uniaxial compression of SAM lattices show that chain and methyl tilting is predominant in PDT/Au, ODT/Ag and PDT/Ag, whereas single and double gauche defect formation is predominant in ODT/Au. Time-resolved shock data showing transient SFG signal loss of ODT/Au and PDT/Au are fit by calculations of the terminal group orientations as a function of deltaV and their contributions to the SFG hyperpolarizability. The highly elastic response of PDT/Au results from shock-generated methyl and chain tilting. The viscoelastic response of ODT/Au results from shock generation of single and double gauche defects. Isothermal compression simulations help explain and fit the time dependence of shock spectra but generally underestimate the magnitude of SFG signal loss because they do not include effects of high-strain-rate dynamics and shock front and surface irregularities.

Theoretical spectroscopic characterization at low temperatures of detectable sulfur-organic compounds: Ethyl mercaptan and dimethyl sulfide

NASA Astrophysics Data System (ADS)

Senent, M. L.; Puzzarini, C.; Domínguez-Gómez, R.; Carvajal, M.; Hochlaf, M.

2014-03-01

Highly correlated ab initio methods are used for the spectroscopic characterization of ethyl mercaptan (CH3CH232SH, ETSH) and dimethyl sulfide (CH332SCH3, DMS), considering them on the vibrational ground and excited torsional states. Since both molecules show non-rigid properties, torsional energy barriers and splittings are provided. Equilibrium geometries and the corresponding rotational constants are calculated by means of a composite scheme based on CCSD(T) calculations that accounts for the extrapolation to the complete basis set limit and core-correlation effects. The ground and excited states rotational constants are then determined using vibrational corrections obtained from CCSD/cc-pVTZ force-field calculations, which are also employed to determine anharmonic frequencies for all vibrational modes. CCSD(T) and CCSD force fields are employed to predict quartic and sextic centrifugal-distortion constants, respectively. Equilibrium rotational constants are also calculated using CCSD(T)-F12. The full-dimensional anharmonic analysis does not predict displacements of the lowest torsional excited states due to Fermi resonances with the remaining vibrational modes. Thus, very accurate torsional transitions are calculated by solving variationally two-dimensional Hamiltonians depending on the CH3 and SH torsional coordinates of ethyl mercaptan or on the two methyl groups torsions of dimethyl-sulfide. For this purpose, vibrationally corrected potential energy surfaces are computed at the CCSD(T)/aug-cc-pVTZ level of theory. For ethyl mercaptan, calculations show large differences between the gauche (g) and trans (t) conformer spectral features. Interactions between rotating groups are responsible for the displacements of the g-bands with respect to the t-bands that cannot therefore be described with one-dimensional models. For DMS, the CCSD(T) potential energy surface has been semi-empirically adjusted to reproduce experimental data. New assignments are suggested for the methyl torsion bands of ETSH and a reassignment is proposed for the infrared bands of DMS (0 3 → 0 4 and 1 0 → 1 1). Our accurate spectroscopic data should be useful for the analysis of the microwave and far infrared spectra of ETSH and DMS recorded, at low temperatures, either in laboratory or in the interstellar medium.

REACTIONS OF MERCAPTANS. I. FORMATION OF 2-METHYL-2-THIAZOLINE-4- CARBOXYLIC ACID FROM N-ACETYLCYSTEINE. II. A SPECTROPHOTOMETRIC METHOD FOR STUDY OF THE REACTION OF RADIATION-PROTECTIVE MERCAPTANS WITH ARYL DISULFIDES

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

Smith, H.A. Jr.

1962-08-01

I. Methyl 2-methyl-2-thiazoline-4-carboxylate was synthesized and converted to the corresponding acid. The behavior of the carboxythiazoline in various concentrations of mineral acids was studied spectrophotometrically. The cyclization of N-acetylcysteine to form a thiazoline-ring compound in concentrated mineral acids was also studied by this means. N-Acetylcysteine in concentrated mineral acid solutions yielded 2-methyl-2-thiazoline-4-carboxylic acid, which also was obtained by controlied hydrolysis of the corresponding methyl ester. Hydrolysis of methyl 2-methyl2-thiazoline-4-carboxylate, pK 3.05, in 0.1M sodium hydroxide yielded the corresponding carboxythiazoline in solution, pK 2.20 and 4.95. The carboxythiazoline was hydrolyzed very slowly in 7M hydrochloric acid, but the velocity of reactionmore » increased with decreasing acid concentration to a maximum at about pH 1.7; the products were N- and Sacetylcysteine, as well as cysteine and acetic acid. At acid concentrations below 0.2M, the last two products were formed slowly, and a pseudo-equilibrium could be established between thiazolinium ion, N-, and S-acetylcysteine. Equilibrium constants were determined. II. 4,4'-Dithiobis (benzenesulfonic acid) (I) and 4,4'-dithiobis(1-naphthalenesulfonic acid) (II) were synthesized from sulfanilic and naphthionic acids, respectively. The absorption spectra of I and II and of the corresponding mercaptans were determined. The thiol-disuifide interchange reactions were studied by spectrophotometric means for the reactions of cysteine with I and with II, and the equilibrium constants were determined. The systems had spectra very similar to those of the respective mixed disuifides with cysteine, and it was not possible to determine the concentrations from absorbancy measurements. On the other hand, the mercaptide ions had spectra different from the other species, with maxima at 285 and 348 m mu , respectively, and the concentrations of the corresponding mercaptans could be calculated from the absorbancies at these wavelengths. By appropriate choice of the initial concentrations and of pH, the equilibrium concentrations could be made negligible, and the equilibrium constants determined.« less

Cu-catalyzed Suzuki-Miyaura reactions of primary and secondary benzyl halides with arylboronates.

PubMed

Sun, Yan-Yan; Yi, Jun; Lu, Xi; Zhang, Zhen-Qi; Xiao, Bin; Fu, Yao

2014-09-28

A copper-catalyzed Suzuki-Miyaura coupling of benzyl halides with arylboronates is described. Varieties of primary benzyl halides as well as more challenging secondary benzyl halides with β hydrogens or steric hindrance could be successfully converted into the corresponding products. Thus it provides access to diarylmethanes, diarylethanes and triarylmethanes.

Novel hydrophobic hemicelluloses: synthesis and characteristic.

PubMed

Junli, Ren; Xinwen, Peng; Linxin, Zhong; Feng, Peng; Runcang, Sun

2012-06-05

Novel hydrophobic hemicelluloses possessing hydrophobic groups were prepared by the benzylation of wheat straw hemicelluloses with benzyl chloride under the presence of catalyst in an ethanol/water system. In particular, the progress of the benzylation reaction was studied as a function of the volume ratio of ethanol/water from 4:1 to 6:4, the molar ratio of NaOH/anhydroxylose unit in hemicelluloses from 0.6:1 to 1.5:1, the molar ratio of benzyl chloride/anhydroxylose unit in hemicelluloses from 0.5:1 to 2.0:1, reaction temperature 50-80 °C, and reaction time 4-20 h Benzylated hemicelluloses with the low degree of substitution from 0.09 to 0.35 were obtained depending on the experimental conditions. The incorporation of benzyl groups into the backbone of hemicelluloses was confirmed by FT-IR and (13)C NMR spectroscopies. The thermal stability increased after the modification of hemicelluloses due to the introduction of benzyl groups. The introduction of benzyl groups endows hemicelluloses with the hydrophobicity, which could be potentially applied in plastic industries. Copyright © 2012 Elsevier Ltd. All rights reserved.

Chemoselective organocatalytic aerobic oxidation of primary amines to secondary imines.

PubMed

Wendlandt, Alison E; Stahl, Shannon S

2012-06-01

Biomimetic aerobic oxidation of primary benzylic amines has been achieved by using a quinone catalyst. Excellent selectivity is observed for primary, unbranched benzylic amines relative to secondary/tertiary amines, branched benzylic amines, and aliphatic amines. The exquisite selectivity for benzylic amines enables oxidative self-sorting within dynamic mixtures of amines and imines to afford high yields of cross-coupled imine products.

[Determination of benzyl glucosinolate in Lepidium meyenii from different regions by HPLC].

PubMed

Tang, Lin; Yin, Hong-jun; Si, Cong-cong; Hu, Xiao-yan; Long, Zheng-hai

2015-12-01

The content of benzyl isothiocyanate (BITC) which as the enzymatic hydrolysis product of benzyl glucosinolate through thioglucosidase was determined by HPLC. The content of benzyl isothiocyanate (BITC) which as the enzymatic hydrolysis product of benzyl glucosinolate through thioglucosidase was determined by HPLC. The chromatography condition was as follows: Kaseisorb LC ODS 2000 (4.6 mm x 150 mm, 5 min) column with the mobile phase of acetonitrile(A)-water( B) under gradient elution (0-5 min, 3%-8% A; 5-9 min, 8%-48% A; 9-23 min, 48%-62% A; 23-28 min, 62%-99% A); the flow rate was 1.0 mL x min(-1) with 10 microL injection volume; detection wavelength was 246 nm and temperature of column was 40 degrees C. The content of benzyl glucosinolate was in the range of 10.76-17.91 g x L(-1). The method is simple, accurate and good reproducibility which can be used for the determination of benzyl glucosinolate in Lepidium meyenii, effectively.

Understanding the Science Behind How Methylene Chloride/Phenolic Chemical Paint Strippers Remove Coatings

DTIC Science & Technology

2011-10-01

general terms the use of alternative paint strippers formulated with water, formic acids, benzyl alcohol, and peroxides . Facilities testing these...based on benzyl alcohol and peroxide .6 In this system the benzyl alcohol serves as a carrier to penetrate and soften the coating while the peroxide ...34 27. FTIR spectrum of the epoxy primer exposed to 20% benzyl alcohol in methylene chloride

Effect of strain hardening on friction behavior of iron lubricated with benzyl structures

NASA Technical Reports Server (NTRS)

Buckley, D. H.; Brainard, W. A.

1974-01-01

Sliding friction experiments were conducted with iron, copper, and aluminum in contact with iron in various states of strain. The surfaces were examined in dry sliding and with various benzyl compounds applied as lubricants. Friction experiments were conducted with a hemispherical rider contacting a flat disk at loads of from 50 to 600 grams with a sliding speed of 0.15 cm/min. Results indicate that straining increases friction for dry sliding and for surfaces lubricated with certain benzyl structures such as dibenzyl disulfide. With other benzyl compounds (e.g., benzyl formate), friction coefficients are lower for strained than for annealed iron.

Asymmetric synthesis of all-carbon benzylic quaternary stereocenters via Cu-catalyzed conjugate addition of dialkylzinc reagents to 5-(1-arylalkylidene) Meldrum's acids.

PubMed

Fillion, Eric; Wilsily, Ashraf

2006-03-08

The asymmetric synthesis of all-carbon benzylic quaternary stereocenters has been successfully achieved through copper-catalyzed addition of dialkylzinc reagents to 5-(1-arylalkylidene) and 5-(dihydroindenylidene) Meldrum's acids in the presence of phosphoramidite ligand. The resulting benzyl-substituted Meldrum's acids and 1,1-disubstituted indanes were obtained in good yields and up to 99% ee. The significance of substituting the position para, meta, and ortho to the electrophilic benzylic center was highlighted. A benzyl Meldrum's acid product was further transformed to a 3,3-disubstituted 1-indanone and a beta,beta-disubstituted pentanoic acid.

Thiol surface functionalization via continuous phase plasma polymerization of allyl mercaptan, with subsequent maleimide-linked conjugation of collagen.

PubMed

Stynes, Gil D; Gengenbach, Thomas R; Kiroff, George K; Morrison, Wayne A; Kirkland, Mark A

2017-07-01

Thiol groups can undergo a large variety of chemical reactions and are used in solution phase to conjugate many bioactive molecules. Previous research on solid substrates with continuous phase glow discharge polymerization of thiol-containing monomers may have been compromised by oxidation. Thiol surface functionalization via glow discharge polymerization has been reported as requiring pulsing. Herein, continuous phase glow discharge polymerization of allyl mercaptan (2-propene-1-thiol) was used to generate significant densities of thiol groups on a mixed macrodiol polyurethane and tantalum. Three general classes of chemistry are used to conjugate proteins to thiol groups, with maleimide linkers being used most commonly. Here the pH specificity of maleimide reactions was used effectively to conjugate surface-bound thiol groups to amine groups in collagen. XPS demonstrated surface-bound thiol groups without evidence of oxidation, along with the subsequent presence of maleimide and collagen. Glow discharge reactor parameters were optimized by testing the resistance of bound collagen to degradation by 8 M urea. The nature of the chemical bonding of collagen to surface thiol groups was effectively assessed by colorimetric assay (ELISA) of residual collagen after incubation in 8 M urea over 8 days and after incubation with keratinocytes over 15 days. The facile creation of useable solid-supported thiol groups via continuous phase glow discharge polymerization of allyl mercaptan opens a route for attaching a vast array of bioactive molecules. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 1940-1948, 2017. © 2017 Wiley Periodicals, Inc.

Cellulose Derivatives for Water Repellent Properties

USDA-ARS?s Scientific Manuscript database

Synthesis and structural characterizations of nitro-benzyl cellulose, amino-benzyl cellulose and pentafluoro –benzyl cellulose were carried out. Cellulose derivatives were synthesized by etherification process in lithium chloride/N,N-dimethylacetamide homogeneous solution. Nitrobenzylation was effec...

Growth and characterization of benzyl 4-hydroxybenzoate single crystal by vertical Bridgman technique for optical applications

NASA Astrophysics Data System (ADS)

Solanki, S. Siva Bala; Rajesh, N. P.; Suthan, T.

2018-07-01

The benzyl 4-hydroxybenzoate single crystal has been grown by vertical Bridgman technique. The grown crystal was confirmed by single crystal X-ray diffraction studies. The presence of functional groups in the crystal was confirmed by Fourier transform infrared (FTIR) spectral studies. The thermal behaviour of the grown crystal was analyzed by thermogravimetric analysis (TGA), differential thermal analysis (DTA) and differential scanning calorimetric (DSC) studies. Optical behaviour of the grown benzyl 4-hydroxybenzoate crystal was studied by UV-Vis-NIR spectral analysis. Fluorescence spectrum shows near violet light emission. The second harmonic generation behaviour of benzyl 4-hydroxybenzoate was analyzed. The laser damage threshold value of benzyl 4-hydroxybenzoate was measured as 2.16 GW/cm2. The dielectric measurements of benzyl 4-hydroxybenzoate crystal were carried out with different frequencies 1 kHz to 1 MHz versus different temperatures ranging from 313 to 353 K. Photoconductivity study shows that the grown benzyl 4-hydroxybenzoate crystal belongs to negative photoconductivity property. The mechanical strength of the crystal was calculated by Vickers microhardness study.

Atmospheric Deposition of Mercury

EPA Science Inventory

With the advent of the industrial era, the amount of mercury entering the global environment increased dramatically. Releases of mercury in its elemental form from gold mines and chlor-alkali plants, as sulfides such as mercaptans and agricultural chemicals, and as volatile emiss...

A direct conversion of benzylic and allylic alcohols to phosphonates

PubMed Central

Barney, Rocky J.; Richardson, Rebekah M.; Wiemer, David F.

2011-01-01

Benzyl phosphonate esters often serve as reagents in Horner-Wadsworth-Emmons reactions. In most cases, they can be prepared from benzylic alcohols via formation of the corresponding halide followed by an Arbuzov reaction. To identify a more direct synthesis of phosphonate esters, we have developed a one-flask procedure for conversion of benzylic and allylic alcohols to the corresponding phosphonates through treatment with triethyl phosphite and ZnI2. PMID:21405073

Benzyl alcohol toxicity: impact on neurologic handicaps among surviving very low birth weight infants.

PubMed

Benda, G I; Hiller, J L; Reynolds, J W

1986-04-01

Benzyl alcohol preservative in solutions used to flush intravascular catheters has been linked with increased mortality and incidence of intraventricular hemorrhage in small preterm infants. This study evaluated the outcome of surviving very low birth weight infants exposed to benzyl alcohol while in our neonatal intensive care unit. Surviving infants, less than 1,250 g birth weight, admitted during the 12 months prior to discontinuation of benzyl alcohol (period I), were compared with those infants admitted during the 12 months after discontinuation of benzyl alcohol (period II). Survivors were enrolled in a follow-up program. Results of the study demonstrated that infants from period II had fewer neurologic handicaps. The incidence of cerebral palsy decreased from 50% to 2.4% (P less than .001), and the presence of cerebral palsy and developmental delay combined decreased from 53.9% to 11.9% (P less than .001). Several factors other than benzyl alcohol exposure were examined for their importance on outcome but were found not to be related to it. It is concluded that the dramatic improvement in outcome could be the result of discontinuation of benzyl alcohol.

Synthesis and Characterization of Cellulose Derivatives for Water Repellent Properties

USDA-ARS?s Scientific Manuscript database

In this presentation, we will discuss the synthesis and structural characterizations of nitro-benzyl cellulose (1), amino-benzyl cellulose (2) and pentafluoro –benzyl cellulose (3). All cellulose derivatives are synthesized by etherification process in lithium chloride/N,N-dimethylacetamide homogene...

A new approach to synthesis of benzyl cinnamate: Optimization by response surface methodology.

PubMed

Zhang, Dong-Hao; Zhang, Jiang-Yan; Che, Wen-Cai; Wang, Yun

2016-09-01

In this work, the new approach to synthesis of benzyl cinnamate by enzymatic esterification of cinnamic acid with benzyl alcohol is optimized by response surface methodology. The effects of various reaction conditions, including temperature, enzyme loading, substrate molar ratio of benzyl alcohol to cinnamic acid, and reaction time, are investigated. A 5-level-4-factor central composite design is employed to search for the optimal yield of benzyl cinnamate. A quadratic polynomial regression model is used to analyze the experimental data at a 95% confidence level (P<0.05). The coefficient of determination of this model is found to be 0.9851. Three sets of optimum reaction conditions are established, and the verified experimental trials are performed for validating the optimum points. Under the optimum conditions (40°C, 31mg/mL enzyme loading, 2.6:1 molar ratio, 27h), the yield reaches 97.7%, which provides an efficient processes for industrial production of benzyl cinnamate. Copyright © 2016 Elsevier Ltd. All rights reserved.

Ultraviolet photodissociation dynamics of the benzyl radical.

PubMed

Song, Yu; Zheng, Xianfeng; Lucas, Michael; Zhang, Jingsong

2011-05-14

Ultraviolet (UV) photodissociation dynamics of jet-cooled benzyl radical via the 4(2)B(2) electronically excited state is studied in the photolysis wavelength region of 228 to 270 nm using high-n Rydberg atom time-of-flight (HRTOF) and resonance enhanced multiphoton ionization (REMPI) techniques. In this wavelength region, H-atom photofragment yield (PFY) spectra are obtained using ethylbenzene and benzyl chloride as the precursors of benzyl radical, and they have a broad peak centered around 254 nm and are in a good agreement with the previous UV absorption spectra of benzyl. The H + C(7)H(6) product translational energy distributions, P(E(T))s, are derived from the H-atom TOF spectra. The P(E(T)) distributions peak near 5.5 kcal mol(-1), and the fraction of average translational energy in the total excess energy, , is ∼0.3. The P(E(T))s indicate the production of fulvenallene + H, which was suggested by recent theoretical studies. The H-atom product angular distribution is isotropic, with the anisotropy parameter β ≈ 0. The H/D product ratios from isotope labeling studies using C(6)H(5)CD(2) and C(6)D(5)CH(2) are reasonably close to the statistical H/D ratios, suggesting that the H/D atoms are scrambled in the photodissociation of benzyl. The dissociation mechanism is consistent with internal conversion of the electronically excited benzyl followed by unimolecular decomposition of the hot benzyl radical on the ground state.

40 CFR 464.21 - Specialized definitions.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 67. butyl benzyl phthalate 68. di-n-butyl phthalate 70. diethyl phthalate 71. dimethyl phthalate 72... 67. butyl benzyl phthalate 68. di-n-butyl phthalate 70. diethyl phthalate 71. dimethyl phthalate 72...-ethylhexyl) phthalate 67. butyl benzyl phthalate 68. di-n-butyl phthalate 70. diethyl phthalate 71. dimethyl...

40 CFR 464.21 - Specialized definitions.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 67. butyl benzyl phthalate 68. di-n-butyl phthalate 70. diethyl phthalate 71. dimethyl phthalate 72... 67. butyl benzyl phthalate 68. di-n-butyl phthalate 70. diethyl phthalate 71. dimethyl phthalate 72...-ethylhexyl) phthalate 67. butyl benzyl phthalate 68. di-n-butyl phthalate 70. diethyl phthalate 71. dimethyl...

Terahertz and far-infrared synchrotron spectroscopy and global modeling of methyl mercaptan, CH332SH

NASA Astrophysics Data System (ADS)

Xu, Li-Hong; Lees, R. M.; Crabbe, G. T.; Myshrall, J. A.; Müller, H. S. P.; Endres, C. P.; Baum, O.; Lewen, F.; Schlemmer, S.; Menten, K. M.; Billinghurst, B. E.

2012-09-01

In this work, terahertz and Fourier transform far-infrared (FTFIR) synchrotron spectra of methyl mercaptan, CH3SH, have been investigated in order to provide new laboratory information for enhanced observations of this species in interstellar molecular clouds and star-forming regions. Like its methanol cousin, methyl mercaptan has particularly rich spectra associated with its large-amplitude internal rotation that extend throughout the THz and FIR regions. We have recorded new spectra for CH3SH from 1.1-1.5 and 1.790-1.808 THz at the University of Cologne as well as high-resolution FTFIR synchrotron spectra from 50-550 cm-1 at 0.001 cm-1 resolution on the far-IR beam-line at the Canadian Light Source. Assignments are reported for rotational quantum numbers up to J ≈ 40 and K ≈ 15, and torsional states up to vt = 2 for the THz measurements and vt = 3 for the FTFIR observations. The THz and FTFIR measurements together with literature results have been combined in a global analysis of a dataset comprising a total of 1725 microwave and THz frequencies together with ˜18000 FTFIR transitions, ranging up to vt = 2 and Jmax = 30 for MW/THz and 40 for FTFIR. The global fit employs 78 torsion-rotation parameters and has achieved a weighted standard deviation of ˜1.1. A prediction list (vt ≤ 2, J ≤ 45 and K ≤ 20) has been generated from the model giving essentially complete coverage of observable CH332SH transitions within the bandwidths of major new astronomical facilities such as HIFI (Heterodyne Instrument for the Far Infrared) on the Herschel Space Observatory, ALMA (Atacama Large Millimeter Array), SOFIA (Stratospheric Observatory For Infrared Astronomy) and APEX (Atacama Pathfinder Experiment) to close to spectroscopic accuracy.

Acid-Catalyzed Enolization of [beta]-Tetralone

ERIC Educational Resources Information Center

Dewprashad, Brahmadeo; Nesturi, Anthony; Urena, Joel

2008-01-01

This experiment allows students to use [to the first power]H NMR to directly compare the relative initial rates of substitution of the benzylic and non-benzylic [alpha] hydrogens of [beta]-tetralone and correlate their findings with the predictions made by resonance theory. The experiment demonstrates that the benzylic hydrogens undergo [alpha]…

Benzylic Fluorination of Aza-Heterocycles Induced by Single-Electron Transfer to Selectfluor.

PubMed

Danahy, Kelley E; Cooper, Julian C; Van Humbeck, Jeffrey F

2018-04-23

A selective and mild method for the benzylic fluorination of aromatic azaheterocycles with Selectfluor is described. These reactions take place by a previously unreported mechanism, in which electron transfer from the heterocyclic substrate to the electrophilic fluorinating agent Selectfluor eventually yields a benzylic radical, thus leading to the desired C-F bond formation. This mechanism enables high intra- and intermolecular selectivity for aza-heterocycles over other benzylic components with similar C-H bond-dissociation energies. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Analysis of macamides in samples of Maca (Lepidium meyenii) by HPLC-UV-MS/MS.

PubMed

McCollom, Megan M; Villinski, Jacquelyn R; McPhail, Kerry L; Craker, Lyle E; Gafner, Stefan

2005-01-01

The macamides are a distinct class of secondary metabolites that have so far been found only in Lepidium meyenii Walp. (Maca). Using HPLC-UV-MS/MS, the main macamides have been identified as n-benzylhexadecanamide, n-benzyl-(9Z)-octadecenamide, n-benzyl-(9Z, 12Z)-octadecadienamide, n-benzyl-(9Z, 12Z, 15Z)-octadecatrienamide and n-benzyloctadecanamide. The identities of n-benzyl-(9Z)-octadecenamide and n-benzyl-(9Z, 12Z)-octadecadienamide were confirmed by comparison of chromatographic and spectral properties with synthetic analogues. Total macamides have been quantified by HPLC-UV in plant material from different vendors using n-benzylhexadecanamide as an external standard. The amount of macamides in the dried plant material ranged from 0.0016 to 0.0123%.

40 CFR 63.191 - Definitions.

Code of Federal Regulations, 2014 CFR

2014-07-01

... polycarbonate. Methylene chloride is used as a solvent in this polymerization reaction. Polysulfide rubber means... product of reaction of butadiene with excess furfural in a liquid phase reactor. R-11 is usually used as... is not limited to, the reaction of tetrahydrophthalimide and perchloromethyl mercaptan with caustic...

40 CFR 63.191 - Definitions.

Code of Federal Regulations, 2011 CFR

2011-07-01

... polycarbonate. Methylene chloride is used as a solvent in this polymerization reaction. Polysulfide rubber means... product of reaction of butadiene with excess furfural in a liquid phase reactor. R-11 is usually used as... is not limited to, the reaction of tetrahydrophthalimide and perchloromethyl mercaptan with caustic...

40 CFR 63.191 - Definitions.

Code of Federal Regulations, 2012 CFR

2012-07-01

... polycarbonate. Methylene chloride is used as a solvent in this polymerization reaction. Polysulfide rubber means... product of reaction of butadiene with excess furfural in a liquid phase reactor. R-11 is usually used as... is not limited to, the reaction of tetrahydrophthalimide and perchloromethyl mercaptan with caustic...

40 CFR 63.191 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-07-01

... polycarbonate. Methylene chloride is used as a solvent in this polymerization reaction. Polysulfide rubber means... product of reaction of butadiene with excess furfural in a liquid phase reactor. R-11 is usually used as... is not limited to, the reaction of tetrahydrophthalimide and perchloromethyl mercaptan with caustic...

40 CFR 63.191 - Definitions.

Code of Federal Regulations, 2013 CFR

2013-07-01

... polycarbonate. Methylene chloride is used as a solvent in this polymerization reaction. Polysulfide rubber means... product of reaction of butadiene with excess furfural in a liquid phase reactor. R-11 is usually used as... is not limited to, the reaction of tetrahydrophthalimide and perchloromethyl mercaptan with caustic...

Traceless β-mercaptan-assisted activation of valinyl benzimidazolinones in peptide ligations† †Electronic supplementary information (ESI) available. See DOI: 10.1039/c7sc04148a

PubMed Central

Wang, Yinglu; Han, Lin; Yuan, Ning; Wang, Hanxuan; Li, Hongxing; Liu, Jinrong; Chen, Huan

2018-01-01

Peptidyl thioesters or their surrogates with C-terminal β-branched hydrophobic amino acid residues usually exhibit poor reactivities in ligation reactions. Thus, activation using exogenous additives is required to ensure an acceptable reaction efficiency. Herein, we report a traceless ligation at Val-Xaa sites under mild thiol additive-free reaction conditions, whereby the introduction of β-mercaptan on the C-terminal valine residue effectively activates the otherwise unreactive N-acyl-benzimidazolinone (Nbz), and enables the use of a one-pot ligation–desulfurization strategy to generate the desired peptide products. The orthogonality between β-thiovaline-Nbz and a conventional alkyl thioester, as well as the convenient access to the former from readily available penicillamine, also allowed expedited assembly of the peptidic hormone β-LPH and hPTH analogues, based on a kinetically controlled one-pot three-segment ligation and desulfurization strategy. PMID:29675240

Self-healing of low-velocity impact damage in glass fabric/epoxy composites using an epoxy-mercaptan healing agent

NASA Astrophysics Data System (ADS)

Chao Yuan, Yan; Ye, Yueping; Zhi Rong, Min; Chen, Haibin; Wu, Jingshen; Qiu Zhang, Ming; Qin, Shi Xiang; Yang, Gui Cheng

2011-01-01

Self-healing woven glass fabric-reinforced epoxy composite laminates were made by embedding epoxy- and mercaptan-loaded microcapsules. After being subjected to low-velocity impact, the laminates were able to heal the damage in an autonomic way at room temperature. The healing-induced reduction in the damaged areas was visualized using a scanning acoustic microscope. The rate of damage area reduction, which is closely related to the effect of crack rehabilitation and mechanical recovery, is a function of impact energy, content and size of the healing microcapsules. Minor damage, such as microcracks in the matrix, can be completely repaired by the healing system without manual intervention, including external pressure. Microcapsules with larger size and/or higher concentration are propitious for delivering more healing agent to cracked portions, while imposition of lateral pressure on damaged specimens forces the separated faces to approach each other. Both can improve the rate of damage area reduction in the case of severe damage.

The structure feature of layered M1/3TiNbO5 (M=Fe, Ce) and their photocatalytic oxidization performance for ethyl mercaptan

NASA Astrophysics Data System (ADS)

Dong, Rui; Wang, Yuan; Wang, Ningning; Xu, Lei; He, Jie; Wu, Shanshan; Lan, Yunxiang; Hu, Jinsong

2016-09-01

Layered photocatalytic materials M1/3TiNbO5 (M = Fe, Ce) were prepared by ion-exchange of KTiNbO5 with M(NO3)3. The parent KTiNbO5 was synthesized with titanium (IV) isopropoxide and niobium oxalate by a novel polymerized complex (PC) method. The micro-structures and spectral response features of the as-prepared samples were characterized by powder X-ray diffraction (XRD), transmission electron microscope (TEM), laser Raman spectroscopy (LRS) and UV-vis diffuse reflectance spectroscopy (UV-vis DRS). The results revealed that there was a significant interaction between the interlayer cation and the terminal Nbdbnd O (Tidbnd O) bond in the NbO6 (TiO6) unit of the laminates. Photocatalytic performance was evaluated in oxidation of ethyl mercaptan under natural and UV light irradiation. It can be deduced that the photocatalytic oxidization performance can be directly affected by the characteristics of the interlayer cations.

Primary amino acid derivatives: substitution of the 4'-N'-benzylamide site in (R)-N'-benzyl 2-amino-3-methylbutanamide, (R)-N'-benzyl 2-amino-3,3-dimethylbutanamide, and (R)-N'-benzyl 2-amino-3-methoxypropionamide provides potent anticonvulsants with pain-attenuating properties.

PubMed

King, Amber M; Salomé, Christophe; Salomé-Grosjean, Elise; De Ryck, Marc; Kaminski, Rafal; Valade, Anne; Stables, James P; Kohn, Harold

2011-10-13

Recently, we reported that select N'-benzyl 2-substituted 2-amino acetamides (primary amino acid derivatives (PAADs)) exhibited pronounced activities in established whole animal anticonvulsant (i.e., maximal electroshock seizure (MES)) and neuropathic pain (i.e., formalin) models. The anticonvulsant activities of C(2)-hydrocarbon N'-benzyl 2-amino acetamides (MES ED(50) = 13-21 mg/kg) exceeded those of phenobarbital (ED(50) = 22 mg/kg). Two additional studies defining the structure-activity relationship of PAADs are presented in this issue of the journal. In this study, we demonstrated that the anticonvulsant activities of (R)-N'-benzyl 2-amino-3-methylbutanamide and (R)-N'-benzyl 2-amino-3,3-dimethylbutanamide were sensitive to substituents at the 4'-N'-benzylamide site; electron-withdrawing groups retained activity, electron-donating groups led to a loss of activity, and incorporating either a 3-fluorobenzyloxy or 3-fluorophenoxymethyl group using a rationally designed multiple ligand approach improved activity. Additionally, we showed that substituents at the 4'-N'-benzylamide site of (R)-N'-benzyl 2-amino-3-methoxypropionamide also improved anticonvulsant activity, with the 3-fluorophenoxymethyl group providing the largest (∼4-fold) increase in activity (ED(50) = 8.9 mg/kg), a value that surpassed phenytoin (ED(50) = 9.5 mg/kg). Collectively, the pharmacological findings provided new information that C(2)-hydrocarbon PAADs represent a novel class of anticonvulsants.

Benzyl-Functionalized Room Temperature Ionic Liquids for CO2/N2 Separation

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

Mahurin, Shannon Mark; Dai, Thomas N; Yeary, Joshua S

2011-01-01

In this work, three classes of room temperature ionic liquids (RTILs), including imidazolium, pyridinium, and pyrrolidinium ionic liquids with a benzyl group appended to the cation, were synthesized and tested for their performance in separating CO{sub 2} and N{sub 2}. All RTILs contained the bis(trifluoromethylsulfonyl)imide anion, permitting us to distinguish the impact of the benzyl moiety attached to the cation on gas separation performance. In general, the attachment of the benzyl group increased the viscosity of the ionic liquid compared with the unfunctionalized analogs and decreased the CO{sub 2} permeability. However, all of the benzyl-modified ionic liquids exhibited enhanced CO{submore » 2}/N{sub 2} selectivities compared with alkyl-based ionic liquids, with values ranging from 22.0 to 33.1. In addition, CO{sub 2} solubilities in the form of Henry's constants were also measured and compared with unfunctionalized analogs. Results of the membrane performance tests and CO{sub 2} solubility measurements demonstrate that the benzyl-functionalized RTILs have significant potential for use in the separation of carbon dioxide from combustion products.« less

Carbene-catalysed reductive coupling of nitrobenzyl bromides and activated ketones or imines via single-electron-transfer process

NASA Astrophysics Data System (ADS)

Li, Bao-Sheng; Wang, Yuhuang; Proctor, Rupert S. J.; Zhang, Yuexia; Webster, Richard D.; Yang, Song; Song, Baoan; Chi, Yonggui Robin

2016-09-01

Benzyl bromides and related molecules are among the most common substrates in organic synthesis. They are typically used as electrophiles in nucleophilic substitution reactions. These molecules can also be activated via single-electron-transfer (SET) process for radical reactions. Representative recent progress includes α-carbon benzylation of ketones and aldehydes via photoredox catalysis. Here we disclose the generation of (nitro)benzyl radicals via N-heterocyclic carbene (NHC) catalysis under reductive conditions. The radical intermediates generated via NHC catalysis undergo formal 1,2-addition with ketones to eventually afford tertiary alcohol products. The overall process constitutes a formal polarity-inversion of benzyl bromide, allowing a direct coupling of two initially electrophilic carbons. Our study provides a new carbene-catalysed reaction mode that should enable unconventional transformation of (nitro)benzyl bromides under mild organocatalytic conditions.

Thermodynamic and fluorescence studies of the underlying factors in benzyl alcohol-induced lipid interdigitated phase.

PubMed

Chen, C H; Hoye, K; Roth, L G

1996-09-15

To further investigate factors contributing to the action of alcohol in the solute-induced lipid interdigitation phase, thermodynamic and fluorescence polarization measurements were carried out to study the interaction of benzyl alcohol with dipalmitoyl phosphatidylcholine bilayer vesicles. The obtained results were compared with those previously reported for ethanol and cyclohexanol (L. G. Roth and C-H. Chen, Arch. Biochem. Biophys. 296, 207, 1992). Similar to ethanol, benzyl alcohol was found to exhibit a biphasic effect on the enthalpy (delta Hm) and the temperature (tm) of the lipid-phase transition and the steady-state fluorescence polarization (P) monitored by 1,6-diphenyl-1,3,5-hexatriene. At a total concentration of benzyl alcohol < 30 mg/ml (the alcohol concentration in lipid phase < 21 mg/ml), benzyl alcohol was found to exhibit large increases in delta Hm and P, which were correlated with the formation of a lipid interdigitated phase, as evidenced by reported X-ray diffraction data. Combining the results with benzyl alcohol and ethanol suggested that simultaneously large changes in delta Hm and P can be used as an indication of the occurrence of a solute-induced lipid interdigitated phase. The overall interacting force in the formation of this lipid phase, as derived from the interactions of the hydroxyl portion of an alcohol with the lipid phosphate head group and the hydrophobic portion of an alcohol with the lipid hydrocarbon chains, may or may not be dominated by hydrophobic interaction. Although lipid/water partition coefficients and the contribution of hydrophobic interaction to the overall interacting force were comparable between benzyl alcohol and cyclohexanol, benzyl alcohol induced lipid interdigitated phase, but not for cyclohexanol. This was due to the ability of benzyl alcohol to be more effective than cyclohexanol in simultaneously interacting with the phosphate head group and the hydrocarbon chains of lipid.

Polymercaptanized soybean oil – properties and tribological characterization

USDA-ARS?s Scientific Manuscript database

Polymercaptanized vegetable oils are produced in industrial scale by the addition of hydrogen sulfide across double bonds or epoxides of vegetable oils, in the presence of UV-light. To date, soybean oil, epoxidized soybean oil, and castor oil has been mercaptanized using such a procedure. Depending ...

Handbook for Evaluating Ecological Effects of Pollution at DARCOM installations. Volume 2, Essential Background Data. (Installation Environmental Impact Assessment)

DTIC Science & Technology

1979-12-01

Nitrates Sulfur dioxide Xylene Nitrites Oxides of nitrogen Mercaptans "Red Water" Carbon monoxide Chlorine Acids: Ketones Fluorine Hydrochloric Esters...Trichloroethylene Varnishes Methylchloroform Undercoatings Mineral spirits Liquid styrene Naphtha Adhesives Halgenated hydrocarbons Nonmethane hydrocarbons

Search for soliton modes in helical poly-γ-benzyl-l-glutamate

NASA Astrophysics Data System (ADS)

Renthal, Robert; Taboada, J.

1989-07-01

Solid α-helical poly(γ-benzyl-L-glutamate) was examined at low temperature for evidence of the unusual temperature-dependent vibrational mode found by Careri and co-workers in solid acetanilide and attributed to a soliton wave trapped in protein-like hydrogen bonds. We have confirmed the anomaly in acetanilide, however, a similar temperature-dependent mode was not observed in poly(γ-benzyl-L-glutamate). These results indicate that anharmonic amide modes may only be present in certain α-helical structures. Two new low frequency modes (180 and 90 cm -1) are observed for poly(γ-benzyl-L-glutamate).

Secondary benzylation with benzyl alcohols catalyzed by a high-valent heterobimetallic Ir-Sn complex.

PubMed

Podder, Susmita; Choudhury, Joyanta; Roy, Sujit

2007-04-13

A highly efficient secondary benzylation procedure has been demonstrated using a high-valent heterobimetallic complex [Ir2(COD)2(SnCl3)2(Cl)2(mu-Cl)2] 1 as the catalyst in 1,2-dichloroethane to afford the corresponding benzylated products in moderate to excellent yields. The reaction was performed not only with carbon nucleophiles (arenes and heteroarenes) but also with oxygen (alcohol), nitrogen (amide and sulfonamide), and sulfur (thiol) nucleophiles. Mechanistic investigation showed the intermediacy of the ether in this reaction. An electrophilic mechanism is proposed from Hammett correlation.

Synthesis of methyl 3-O-alpha-D-mannopyranosyl-alpha-D-talopyranoside and methyl 3-O-alpha-D-talopyranosyl-alpha-D-talopyranoside.

PubMed

Dubey, R; Jain, R K; Abbas, S A; Matta, K L

1987-08-01

Methyl 2-O-benzyl-3-O-(2,3,4,6-tetra-O-acetyl-alpha-D-mannopyranosyl)-alpha- D-mannopyranoside (4) and methyl 2-O-benzyl-3-O-alpha-D-mannopyranosyl-alpha-D-mannopyranoside (6) were prepared from a common intermediate, namely, methyl 2-O-benzyl-4,6-O-benzylidene-3-O-(2,3,4,6-tetra-O-acetyl-alpha-D- mannopyranosyl)-alpha-D-mannopyranoside. On treatment with tert-butylchlorodiphenylsilane, in N,N-dimethylformamide in the presence of imidazole, 4 and 6 afforded methyl 2-O-benzyl-6-O-tert-butyldiphenylsilyl-3-O-(2,3,4,6-tetra-O-acetyl -alpha-D- mannopyranosyl)-alpha-D-mannopyranoside (7), and methyl 2-O-benzyl-6-O-tert-butyldiphenylsilyl-3-O-(6-O-tert- butyldiphenylsilyl-alpha-D-mannopyranosyl)-alpha-D-mannopyranoside (8), respectively. Compound 8 was converted into its 2,3-O-isopropylidene derivative (9), and oxidation of 7 and 9 with pyridinium chlorochromate, and reduction of the resulting carbonyl intermediates gave methyl 2-O-benzyl-6-O-tert-butyldiphenylsilyl-3-O-(2,3,4,6-tetra-O-acetyl -alpha-D- mannopyranosyl)-alpha-D-talopyranoside and methyl 2-O-benzyl-6-O-tert-butyldiphenylsilyl-3-O-(6-O-tert-butyldiphe nylsilyl- 2,3-O-isopropylidene-alpha-D-talopyranosyl)-alpha-D-talopyranoside , respectively. Removal of the protecting groups furnished the title disaccharides.

40 CFR 721.10457 - 1,2-Benzenedicarboxylic acid, mixed esters with benzyl alc., cyclohexanol, 2-ethyl-1-hexanol...

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 31 2014-07-01 2014-07-01 false 1,2-Benzenedicarboxylic acid, mixed... Substances § 721.10457 1,2-Benzenedicarboxylic acid, mixed esters with benzyl alc., cyclohexanol, 2-ethyl-1... reporting. (1) The chemical substance identified as 1,2-benzenedicarboxylic acid, mixed esters with benzyl...

40 CFR 721.10457 - 1,2-Benzenedicarboxylic acid, mixed esters with benzyl alc., cyclohexanol, 2-ethyl-1-hexanol...

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 32 2013-07-01 2013-07-01 false 1,2-Benzenedicarboxylic acid, mixed... Substances § 721.10457 1,2-Benzenedicarboxylic acid, mixed esters with benzyl alc., cyclohexanol, 2-ethyl-1... reporting. (1) The chemical substance identified as 1,2-benzenedicarboxylic acid, mixed esters with benzyl...

Carbene-catalysed reductive coupling of nitrobenzyl bromides and activated ketones or imines via single-electron-transfer process

PubMed Central

Li, Bao-Sheng; Wang, Yuhuang; Proctor, Rupert S. J.; Zhang, Yuexia; Webster, Richard D.; Yang, Song; Song, Baoan; Chi, Yonggui Robin

2016-01-01

Benzyl bromides and related molecules are among the most common substrates in organic synthesis. They are typically used as electrophiles in nucleophilic substitution reactions. These molecules can also be activated via single-electron-transfer (SET) process for radical reactions. Representative recent progress includes α-carbon benzylation of ketones and aldehydes via photoredox catalysis. Here we disclose the generation of (nitro)benzyl radicals via N-heterocyclic carbene (NHC) catalysis under reductive conditions. The radical intermediates generated via NHC catalysis undergo formal 1,2-addition with ketones to eventually afford tertiary alcohol products. The overall process constitutes a formal polarity-inversion of benzyl bromide, allowing a direct coupling of two initially electrophilic carbons. Our study provides a new carbene-catalysed reaction mode that should enable unconventional transformation of (nitro)benzyl bromides under mild organocatalytic conditions. PMID:27671606

Enantioselective Cyanation of Benzylic C–H Bonds via Copper-Catalyzed Radical Relay

PubMed Central

Zhang, Wen; Wang, Fei; McCann, Scott D.; Wang, Dinghai; Chen, Pinhong; Stahl, Shannon; Liu, Guosheng

2017-01-01

Direct methods for stereoselective functionalization of C(sp3)–H bonds in complex organic molecules could facilitate much more efficient preparation of therapeutics and agrochemicals. Here, we report a copper-catalyzed radical relay pathway for enantioselective conversion of benzylic C–H bonds into benzylic nitriles. Hydrogen-atom abstraction affords an achiral benzylic radical that undergoes asymmetric C(sp3)–CN bond upon reaction with a chiral copper catalyst. The reactions proceed efficiently at room temperature with the benzylic substrate as limiting reagent, exhibit broad substrate scope with high enantioselectivity (typically 90-99% enantiomeric excess), and afford products that are key precursors to important bioactive molecules. Mechanistic studies provide evidence for diffusible organic radicals and highlight the difference between these reactions and C–H oxidations mediated by enzymes and other catalysts that operate via radical rebound pathways. PMID:27701109

Biocatalysis of aromatic benzyl-propionate ester by different immobilized lipases.

PubMed

Sá, Amanda Gomes Almeida; de Meneses, Alessandra Cristina; Lerin, Lindomar Alberto; de Araújo, Pedro Henrique Hermes; Sayer, Cláudia; de Oliveira, Débora

2018-05-01

Benzyl propionate is an aromatic ester that possesses a fruity odor and is usually found in nature in the composition of some fruits such as plums and melons. This work aimed for the benzyl propionate synthesis by esterification using a new immobilized enzyme preparation with low-cost material from Candida antarctica (NS 88011) and three commercial immobilized lipases (Novozym 435, Lipozyme TL-IM and Lipozyme RM-IM). Novozym 435 had the best performance even when the solvent tert-butanol was absent of the reaction medium. Results from a 2 2 factorial design showed that an increase in the enzyme amount led to a higher conversion, even when the temperature was kept at the low value. Currently, no research had synthesized successfully benzyl propionate via esterification mediated by lipases; and we reached an ester conversion of ~ 44% after 24 h indicating that it is a promising route for benzyl propionate biotechnological production.

40 CFR 60.489 - List of chemicals produced by affected facilities.

Code of Federal Regulations, 2013 CFR

2013-07-01

... Resorcylic acid. 69-72-7 Salicylic acid. 127-09-3 Sodium acetate. 532-32-1 Sodium benzoate. 9004-32-4 Sodium... Benzoyl chloride. 100-51-6 Benzyl alcohol. 100-46-9 Benzylamine. 120-51-4 Benzyl benzoate. 100-44-7 Benzyl... 2-ethylhexanol. 122-51-0 Ethyl orthoformate. 95-92-1 Ethyl oxalate. 41892-71-1 Ethyl sodium...

40 CFR 60.489 - List of chemicals produced by affected facilities.

Code of Federal Regulations, 2011 CFR

2011-07-01

... Resorcylic acid. 69-72-7 Salicylic acid. 127-09-3 Sodium acetate. 532-32-1 Sodium benzoate. 9004-32-4 Sodium... Benzoyl chloride. 100-51-6 Benzyl alcohol. 100-46-9 Benzylamine. 120-51-4 Benzyl benzoate. 100-44-7 Benzyl... 2-ethylhexanol. 122-51-0 Ethyl orthoformate. 95-92-1 Ethyl oxalate. 41892-71-1 Ethyl sodium...

40 CFR 60.489 - List of chemicals produced by affected facilities.

Code of Federal Regulations, 2012 CFR

2012-07-01

... Resorcylic acid. 69-72-7 Salicylic acid. 127-09-3 Sodium acetate. 532-32-1 Sodium benzoate. 9004-32-4 Sodium... Benzoyl chloride. 100-51-6 Benzyl alcohol. 100-46-9 Benzylamine. 120-51-4 Benzyl benzoate. 100-44-7 Benzyl... 2-ethylhexanol. 122-51-0 Ethyl orthoformate. 95-92-1 Ethyl oxalate. 41892-71-1 Ethyl sodium...

Thermodynamic confinement and alpha-helix persistence length in poly(gamma-benzyl-L-glutamate)-b-poly(dimethyl siloxane)-b-poly(gamma-benzyl-L-glutamate) triblock copolymers.

PubMed

Papadopoulos, P; Floudas, G; Schnell, I; Lieberwirth, I; Nguyen, T Q; Klok, H-A

2006-02-01

The structure and the associated dynamics of a series of poly(gamma-benzyl-L-glutamate)-b-poly(dimethyl siloxane)-b-poly(gamma-benzyl-L-glutamate) (PBLG-b-PDMS-b-PBLG) triblock copolymers were investigated using small- and wide-angle X-ray scattering, NMR, transmission electron microscopy, and dielectric spectroscopy, respectively. The structural analysis revealed phase separation in the case of the longer blocks with defected alpha-helical segments embedded within the block copolymer nanodomains. The alpha-helical persistence length was found to depend on the degree of segregation; thermodynamic confinement and chain stretching results in the partial annihilation of helical defects.

Growing up Radical: Investigation of Benzyl-Like Radicals with Increasing Chain Lengths

NASA Astrophysics Data System (ADS)

Korn, Joseph A.; Jawad, Khadija M.; Hewett, Daniel M.; Zwier, Timothy S.

2015-06-01

Combustion processes involve complex chemistry including pathways leading to polyaromatic hydrocarbons (PAHs) from small molecule precursors. Resonance stabilized radicals (RSRs) likely play an important role in the pathways to PAHs due to their unusual stability. Benzyl radical is a prototypical RSR that is stabilized by conjugation with the phenyl ring. Earlier work on α-methyl benzyl radical showed perturbations to the spectroscopy due to a hindered methyl rotor. If the alkyl chain is lengthened then multiple conformations become possible. This talk will discuss the jet-cooled spectroscopy of α-ethyl benzyl radical and α-propyl benzyl radical produced from the discharge of 1-phenyl propanol and 1-phenyl butanol respectively. Electronic spectra were obtained via resonant two-photon ionization, and IR spectra were obtained by resonant ion-dip infrared spectroscopy. Kidwell, N. M.; Reilly, N. J.; Nebgen, B.; Mehta-Hurt, D. N.; Hoehn, R. D.; Kokkin, D. L.; McCarthy, M. C.; Slipchenko, L. V.; Zwier, T. S. The Journal of Physical Chemistry A 2013, 117, 13465.

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.

Exhumation of food by turkey vulture

Treesearch

Harvey R. Smith; Richard M. DeGraaf; Richard S. Miller

2002-01-01

The success of Turkey Vultures (Cathartes aura) as forest scavengers is largely due to their highly developed sense of smell (Owre and Nothington 1961). Stager (1964) conducted a set of experiments with ethyl mercaptan which confirmed the ability of Turkey Vultures to locate odors when no visible object was associated with them. Turkey Vultures fly...

40 CFR Appendix A to Part 414 - Non-Complexed Metal-Bearing Waste Streams and Cyanide-Bearing Waste Streams

Code of Federal Regulations, 2010 CFR

2010-07-01

... Mercaptan/Ethanol + Hydrogen sulfide Methanol/H.P. Synthesis from natural gas via synthetic gas Oxo Alcohols... + Ammonia n-Propyl alcohol/Hydrogenation of propionaldehyde, Oxo process SAN resin/Suspension polymerization... methanol Acetaldehyde/Oxidation of ethylene with cupric chloride catalyst Acetic acid/Catalytic oxidation...

Discrimination of the oral microbiota associated with high hydrogen sulfide and methyl mercaptan production

PubMed Central

Takeshita, Toru; Suzuki, Nao; Nakano, Yoshio; Yasui, Masaki; Yoneda, Masahiro; Shimazaki, Yoshihiro; Hirofuji, Takao; Yamashita, Yoshihisa

2012-01-01

Both hydrogen sulfide (H2S) and methyl mercaptan (CH3SH) are frequently detected in large amounts in malodorous mouth air. We investigated the bacterial composition of saliva of 30 subjects with severe oral malodor exhibiting extreme CH3SH/H2S ratios (high H2S but low CH3SH concentrations, n = 14; high CH3SH but low H2S concentrations, n = 16) and 13 subjects without malodor, using barcoded pyrosequencing analysis of the 16S rRNA gene. Phylogenetic community analysis with the UniFrac distance metric revealed a distinct bacterial community structure in each malodor group. The H2S group showed higher proportions of the genera Neisseria, Fusobacterium, Porphyromonas and SR1 than the other two groups, whereas the CH3SH group had higher proportions of the genera Prevotella, Veillonella, Atopobium, Megasphaera, and Selenomonas. Our results suggested that distinct bacterial populations in the oral microbiota are involved in production of high levels of H2S and CH3SH in the oral cavity. PMID:22355729

Discrimination of the oral microbiota associated with high hydrogen sulfide and methyl mercaptan production.

PubMed

Takeshita, Toru; Suzuki, Nao; Nakano, Yoshio; Yasui, Masaki; Yoneda, Masahiro; Shimazaki, Yoshihiro; Hirofuji, Takao; Yamashita, Yoshihisa

2012-01-01

Both hydrogen sulfide (H2S) and methyl mercaptan (CH(3)SH) are frequently detected in large amounts in malodorous mouth air. We investigated the bacterial composition of saliva of 30 subjects with severe oral malodor exhibiting extreme CH(3)SH/H(2)S ratios (high H(2)S but low CH(3)SH concentrations, n 5 14; high CH(3)SH but low H2S concentrations, n 5 16) and 13 subjects without malodor, using barcoded pyrosequencing analysis of the 16S rRNA gene. Phylogenetic community analysis with the UniFrac distance metric revealed a distinct bacterial community structure in each malodor group. The H2S group showed higher proportions of the genera Neisseria, Fusobacterium, Porphyromonas and SR1 than the other two groups, whereas the CH(3)SH group had higher proportions of the genera Prevotella, Veillonella,Atopobium, Megasphaera, and Selenomonas. Our results suggested that distinct bacterial populations in the oral microbiota are involved in production of high levels of H2S and CH3SH in the oral cavity.

Investigating the effects of alkali metal Na addition on catalytic activity of HZSM-5 for methyl mercaptan elimination

NASA Astrophysics Data System (ADS)

Yu, Jie; He, Dedong; Chen, Dingkai; Liu, Jiangping; Lu, Jichang; Liu, Feng; Liu, Pan; Zhao, Yutong; Xu, Zhizhi; Luo, Yongming

2017-10-01

Na-modified HZSM-5 catalysts with different Na loading amounts were prepared by incipient-wetness impregnation method and their catalytic activities for methyl mercaptan catalytic elimination were analyzed. XRD, N2 adsorption-desorption, NH3-TPD, CO2-TPD and FT-IR measurements were carried out to investigate the effects of modification of alkali metal Na on the physicochemical properties of the HZSM-5 zeolite catalyst. Research results illustrated that the introduction of alkali metal Na can improve catalytic activity for CH3SH catalytic elimination. CH3SH can be almost completely converted over 3%-Na/HZSM-5 at 450 °C compared to pure HZSM-5 at 600 °C based on our experimental results and the results from previous research. The improved catalytic activity could be attributed to the regulated acid-base properties of the HZSM-5 catalysts by doping with alkali metal Na. High alkali concentration treatment, however, may destroy the framework structure of the catalyst sample, thus causing the poor stability performance of the obtained catalyst.

Additive In Vitro Antiplasmodial Effect of N-Alkyl and N-Benzyl-1,10-Phenanthroline Derivatives and Cysteine Protease Inhibitor E64

PubMed Central

Wijayanti, Mahardika Agus; Sholikhah, Eti Nurwening; Hadanu, Ruslin; Jumina, Jumina; Supargiyono, Supargiyono; Mustofa, Mustofa

2010-01-01

Potential new targets for antimalarial chemotherapy include parasite proteases, which are required for several cellular functions during the Plasmodium falciparum life cycle. Four new derivatives of N-alkyl and N-benzyl-1,10-phenanthroline have been synthesized. Those are (1)-N-methyl-1,10-phenanthrolinium sulfate, (1)-N-ethyl-1,10-phenanthrolinium sulfate, (1)-N-benzyl-1,10-phenanthrolinium chloride, and (1)-N-benzyl-1,10-phenanthrolinium iodide. Those compounds had potential antiplasmodial activity with IC50 values from 260.42 to 465.38 nM. Cysteine proteinase inhibitor E64 was used to investigate the mechanism of action of N-alkyl and N-benzyl-1,10-phenanthroline derivatives. A modified fixed-ratio isobologram method was used to study the in vitro interactions between the new compounds with either E64 or chloroquine. The interaction between N-alkyl and N-benzyl-1,10-phenanthroline derivatives and E64 was additive as well as their interactions with chloroquine were also additive. Antimalarial mechanism of chloroquine is mainly on the inhibition of hemozoin formation. As the interaction of chloroquine and E64 was additive, the results indicated that these new compounds had a mechanism of action by inhibiting Plasmodium proteases. PMID:22332022

Evidence and quantitation of aromatic organosulfates in ambient aerosols in Lahore, Pakistan

NASA Astrophysics Data System (ADS)

Kundu, S.; Quraishi, T. A.; Yu, G.; Suarez, C.; Keutsch, F. N.; Stone, E. A.

2013-05-01

Organosulfates are important components of atmospheric organic aerosols, yet their structures, abundances, sources and formation processes are not adequately understood. This study presents the identification and quantitation of benzyl sulfate in atmospheric aerosols, which is the first confirmed atmospheric organosulfate with aromatic carbon backbone. Benzyl sulfate was identified and quantified in fine particulate matter (PM2.5) collected in Lahore, Pakistan, during 2007-2008. An authentic standard of benzyl sulfate was synthesized, standardized, and identified in atmospheric aerosols with quadrupole time-of-flight (Q-ToF) mass spectrometry (MS). Benzyl sulfate was quantified in aerosol samples using ultra performance liquid chromatography (UPLC) coupled to negative electrospray ionization triple quadrupole (TQ) MS. The highest benzyl sulfate concentrations were recorded in November and January 2007 (0.50 ± 0.11 ng m-3) whereas the lowest concentration was observed in July (0.05 ± 0.02 ng m-3). To evaluate matrix effects, benzyl sulfate concentrations were determined using external calibration and the method of standard addition; comparable concentrations were detected by the two methods, which ruled out significant matrix effects in benzyl sulfate quantitation. Three additional organosulfates with m/z 187, 201 and 215 were qualitatively identified as aromatic organosulfates with additional methyl substituents by high-resolution mass measurements and tandem MS. The observed aromatic organosulfates form a homologous series analogous to toluene, xylene, and trimethylbenzene, which are abundant anthropogenic volatile organic compounds (VOC), suggesting that aromatic organosulfates may be formed by secondary reactions. However, stronger statistical correlations of benzyl sulfate with combustion tracers (EC and levoglucosan) than with secondary tracers (SO42- and α-pinene-derived nitrooxy organosulfates) suggest that aromatic organosulfates may be emitted from the combustion sources or their subsequent atmospheric processing. Further studies are needed to elucidate the sources and formation pathways of aromatic organosulfates in the atmosphere.

Pharmacokinetics and pharmacodynamics of propofol with or without 2% benzyl alcohol following a single induction dose administered intravenously in cats.

PubMed

Griffenhagen, Gregg M; Rezende, Marlis L; Gustafson, Daniel L; Hansen, Ryan J; Lunghofer, Paul J; Mama, Khursheed R

2015-09-01

To compare the pharmacokinetics and pharmacodynamics of propofol with or without 2% benzyl alcohol administered intravenously (IV) as a single induction dose in cats. Prospective experimental study. Six healthy adult cats, three female intact, three male castrated, weighing 4.8 ± 1.8 kg. Cats received 8 mg kg(-1) IV of propofol (P) or propofol with 2% benzyl alcohol (P28) using a randomized crossover design. Venous blood samples were collected at predetermined time points to 24 hours after drug administration to determine drug plasma concentrations. Physiologic and behavioral variables were also recorded. Propofol and benzyl alcohol concentrations were determined using high pressure liquid chromatography with fluorescence detection. Pharmacokinetic parameters were described using a 2-compartment model. Pharmacokinetic and pharmacodynamic parameters were analyzed using repeated measures anova (p < 0.05). Plasma concentrations of benzyl alcohol were below the lower limits of quantification (LLOQ) at all time points for two of the six cats (33%), and by 30 minutes for the remaining four cats. Propofol pharmacokinetics, with or without 2% benzyl alcohol, were characterized by rapid distribution, a long elimination phase, and a large volume of distribution. No differences were noted between treatments with the exception of clearance from the second compartment (CLD2), which was 23.6 and 38.8 mL kg(-1)  minute(-1) in the P and P28 treatments, respectively. Physiologic and behavioral variables were not different between treatments with the exception of heart rate at 4 hours post administration. The addition of 2% benzyl alcohol as a preservative minimally altered the pharmacokinetics and pharmacodynamics of propofol 1% emulsion when administered as a single IV bolus in this group of cats. These data support the cautious use of propofol with 2% benzyl alcohol for induction of anesthesia in healthy cats. © 2014 Association of Veterinary Anaesthetists and the American College of Veterinary Anesthesia and Analgesia.

Methane oxidation and attenuation of sulphur compounds in landfill top cover systems: Lab-scale tests.

PubMed

Raga, Roberto; Pivato, Alberto; Lavagnolo, Maria Cristina; Megido, Laura; Cossu, Raffaello

2018-03-01

In this study, a top cover system is investigated as a control for emissions during the aftercare of new landfills and for old landfills where biogas energy production might not be profitable. Different materials were studied as landfill cover system in lab-scale columns: mechanical-biological pretreated municipal solid waste (MBP); mechanical-biological pretreated biowaste (PB); fine (PBS f ) and coarse (PBS c ) mechanical-biological pretreated mixtures of biowaste and sewage sludge, and natural soil (NS). The effectiveness of these materials in removing methane and sulphur compounds from a gas stream was tested, even coupled with activated carbon membranes. Concentrations of CO 2 , CH 4 , O 2 , N 2 , H 2 S and mercaptans were analysed at different depths along the columns. Methane degradation was assessed using mass balance and the results were expressed in terms of methane oxidation rate (MOR). The highest maximum and mean MOR were observed for MBP (17.2gCH 4 /m 2 /hr and 10.3gCH 4 /m 2 /hr, respectively). Similar values were obtained with PB and PBS c . The lowest values of MOR were obtained for NS (6.7gCH 4 /m 2 /hr) and PBS f (3.6gCH 4 /m 2 /hr), which may be due to their low organic content and void index, respectively. Activated membranes with high load capacity did not seem to have an influence on the methane oxidation process: MBP coupled with 220g/m 2 and 360g/m 2 membranes gave maximum MOR of 16.5gCH 4 /m 2 /hr and 17.4gCH 4 /m 2 /hr, respectively. Activated carbon membranes proved to be very effective on H 2 S adsorption. Furthermore, carbonyl sulphide, ethyl mercaptan and isopropyl mercaptan seemed to be easily absorbed by the filling materials. Copyright © 2017. Published by Elsevier B.V.

Rapid brain scanning radiopharmaceutical

DOEpatents

Sargent, T.W. III; Shulgin, A.T.; Mathis, C.A.

1987-03-03

A method for detecting the blood flow in animals, particularly in the brain, is provided wherein a detectable amount of a novel radioactive compound of the formula 1 is administered to one animal: as given in figure in patent wherein R[sub 1] and R[sub 2] are independently alkyl of 1 to 6 carbon atoms or benzyl; R[sub 3] is alkyl of 1 to 6 carbon atoms, benzyl, cyclopropylalkyl of 4 to 6 carbon atoms, or cyanoalkyl of 2 to 6 carbon atoms; R[sub 4] is hydrogen, benzyl or alkyl of 1 to 6 carbon atoms; with the provisos that R[sub 4] is not isopropyl and when R[sub 4] is methyl, R[sub 3] is not benzyl; and X is a radioactive halogen. 2 figs.

Rapid brain scanning radiopharmaceutical

DOEpatents

Sargent, III, Thornton W.; Shulgin, Alexander T.; Mathis, Chester A.

1987-01-01

A method for detecting the blood flow in animals, particularly in the brain, is provided wherein a detectable amount of a novel radioactive compound of the formula I is administered to one animal: ##STR1## wherein R.sub.1 and R.sub.2 are independently alkyl of 1 to 6 carbon atoms or benzyl; R.sub.3 is alkyl of 1 to 6 carbon atoms, benzyl, cyclopropylalkyl of 4 to 6 carbon atoms, or cyanoalkyl of 2 to 6 carbon atoms; R.sub.4 is hydrogen, benzyl or alkyl of 1 to 6 carbon atoms; with the provisos that R.sub.4 is not isopropyl and when R.sub.4 is methyl, R.sub.3 is not benzyl; and X is a radioactive halogen.

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.

40 CFR Appendix Vii to Part 261 - Basis for Listing Hazardous Waste

Code of Federal Regulations, 2012 CFR

2012-07-01

..., acrylamide. K015 Benzyl chloride, chlorobenzene, toluene, benzotrichloride. K016 Hexachlorobenzene... Benzotrichloride, benzyl chloride, chloroform, chloromethane, chlorobenzene, 1,4-dichlorobenzene, hexachlorobenzene...

40 CFR Appendix Vii to Part 261 - Basis for Listing Hazardous Waste

Code of Federal Regulations, 2013 CFR

2013-07-01

..., acrylamide. K015 Benzyl chloride, chlorobenzene, toluene, benzotrichloride. K016 Hexachlorobenzene... Benzotrichloride, benzyl chloride, chloroform, chloromethane, chlorobenzene, 1,4-dichlorobenzene, hexachlorobenzene...

40 CFR Appendix Vii to Part 261 - Basis for Listing Hazardous Waste

Code of Federal Regulations, 2011 CFR

2011-07-01

..., acrylamide. K015 Benzyl chloride, chlorobenzene, toluene, benzotrichloride. K016 Hexachlorobenzene... Benzotrichloride, benzyl chloride, chloroform, chloromethane, chlorobenzene, 1,4-dichlorobenzene, hexachlorobenzene...

40 CFR Appendix Vii to Part 261 - Basis for Listing Hazardous Waste

Code of Federal Regulations, 2014 CFR

2014-07-01

..., acrylamide. K015 Benzyl chloride, chlorobenzene, toluene, benzotrichloride. K016 Hexachlorobenzene... Benzotrichloride, benzyl chloride, chloroform, chloromethane, chlorobenzene, 1,4-dichlorobenzene, hexachlorobenzene...

Structure of saligenin: microwave, UV and IR spectroscopy studies in a supersonic jet combined with quantum chemistry calculations.

PubMed

Kumar, Sumit; Singh, Santosh K; Calabrese, Camilla; Maris, Assimo; Melandri, Sonia; Das, Aloke

2014-08-28

In this study, we have determined the structure of a medicinally important molecule saligenin (2-hydroxybenzyl alcohol) using UV, IR and microwave absorption spectroscopy in a supersonic jet combined with ab initio calculations. The structure of the only observed conformer of saligenin corresponds to the global minimum on the conformational surface. The observed structure is stabilized by an intramolecular strong O-H···O hydrogen bonding as well as a very weak O-H···π interaction. The hydrogen bond is formed through phenolic OH as the hydrogen bond donor and benzylic OH as the hydrogen bond acceptor while the O-H···π interaction is through benzylic O-H as the hydrogen bond donor and phenyl group as the hydrogen bond acceptor. It has been observed that the benzylic OH stretching frequency in saligenin is more red-shifted compared to that in benzyl alcohol as the strong O-H···O interaction present in saligenin acts on the benzylic O-H group. In fact, there is a subtle interplay among the strong O-H···O hydrogen bond, weak O-H···π interaction, and steric effects arising from the ortho substitution of the OH group in benzyl alcohol. This fine-tuning of multiple interactions very often governs the specific structures of biomolecules and materials.

Targeting mitochondria: Esters of rhodamine B with triterpenoids are mitocanic triggers of apoptosis.

PubMed

Wolfram, Ratna Kancana; Heller, Lucie; Csuk, René

2018-05-25

Triterpenoic acids, ursolic acid (1), oleanolic acid (2), glycyrrhetinic acid (3) and betulinic acid (4) were converted into their corresponding methyl 5-8 and benzyl esters 9-12 or benzyl amides 21-24. These derivatives served as starting materials for the synthesis of pink colored rhodamine B derivatives 25-36 which were screened for cytotoxicity in colorimetric SRB assays. All of the compounds were cytotoxic for a variety of human tumor cell lines. The activity of the benzyl ester derivatives 29-32 was lower than the cytotoxicity of the methyl esters 25-28. The benzyl amides 33-36 were the most cytotoxic compounds of this series. The most potential compound was a glycyrrhetinic acid rhodamine B benzyl amide 35. This compound showed activity against the different cancer cell lines in a two-digit to low three-digit nano-molar range. Staining experiments combined with fluorescence microscopy showed that this compound triggered apoptosis in A2780 ovarian carcinoma cells and acted as a mitocan. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

New alkamides from maca (Lepidium meyenii).

PubMed

Zhao, Jianping; Muhammad, Ilias; Dunbar, D Chuck; Mustafa, Jamal; Khan, Ikhlas A

2005-02-09

Maca (Lepidium meyenii) has been used as a food in Peru for thousands of years. More recently a wide array of commercial maca products have gained popularity as dietary supplements, with claims of anabolic and aphrodisiac effects, although the biologically active principles are not fully known. In an earlier chemical investigation, two new alkamides and a novel fatty acid, as well as the N-hydroxypyridine derivative, macaridine, were isolated from L. meyenii. Further examination has led to the isolation of five additional new alkamides, namely, N-benzyl-9-oxo-12Z-octadecenamide (1), N-benzyl-9-oxo-12Z,15Z-octadecadienamide (2), N-benzyl-13-oxo-9E,11E-octadecadienamide (3), N-benzyl-15Z-tetracosenamide (4), and N-(m-methoxybenzyl)hexadecanamide (5). Their structures were established by spectrometric and spectroscopic methods including ESI-HRMS, EI-MS, (1)H, (13)C, and 2D NMR, as well as (1)H-(15)N 2D HMBC experiments. In addition, the identity of N-benzyl-15Z-tetracosenamide (4) was confirmed by synthesis. These compounds have been found from only L. meyenii and could be used as markers for authentication and standardization.

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.

Synthesis and blood pressure lowering activity of benzylic ethers of 2-diethylaminoethanol and a related diamine.

PubMed

El-Antably, S M; Soine, T O; Shaath, N A; Gupta, P K

1975-08-01

Based upon the unpublished finding that 3'-hydroxy-4'-(beta-diethylaminoethoxy)-3',4'-dihydroseselin possessed a potent blood pressure lowering effect in the cat at a dose of 1 mg/kg, the present study examined the activities of several related compounds. These compounds were derived by dissection of the parent compound to give four benzylic ethers of 2-diethylaminoethanol and a diamine, derived by replacing the ether oxygen of the parent compound with an N--CH3 function. The simplest compounds were the benzyl and 2,6-dimethoxybenzyl ethers of the aminoalcohol. Closely related to the benzyl compound was a congener with a hydroxymethyl group on the benzylic carbon. The beta-diethylaminoethyl ether of 4-chromanol was the most complex of the ethers. The blood pressure measurements were carried out on male cats and compared to papaverine hydrochloride as a standard. In all cases, the most potent blood pressure lowering activity resided in the parent compound, which was not greatly superior to the diamine but substantially more active than the other compounds.

Synthesis, anticancer and antibacterial activity of salinomycin N-benzyl amides.

PubMed

Antoszczak, Michał; Maj, Ewa; Napiórkowska, Agnieszka; Stefańska, Joanna; Augustynowicz-Kopeć, Ewa; Wietrzyk, Joanna; Janczak, Jan; Brzezinski, Bogumil; Huczyński, Adam

2014-11-25

A series of 12 novel monosubstituted N-benzyl amides of salinomycin (SAL) was synthesized for the first time and characterized by NMR and FT-IR spectroscopic methods. Molecular structures of three salinomycin derivatives in the solid state were determined using single crystal X-ray method. All compounds obtained were screened for their antiproliferative activity against various human cancer cell lines as well as against the most problematic bacteria strains such as methicillin-resistant Staphylococcus aureus (MRSA) and Staphylococcus epidermidis (MRSE), and Mycobacterium tuberculosis. Novel salinomycin derivatives exhibited potent anticancer activity against drug-resistant cell lines. Additionally, two N-benzyl amides of salinomycin revealed interesting antibacterial activity. The most active were N-benzyl amides of SAL substituted at -ortho position and the least anticancer active derivatives were those substituted at the -para position.

Copper-Catalyzed Synthesis of Trifluoroethylarenes from Benzylic Bromodifluoroacetates.

PubMed

Ambler, Brett R; Zhu, Lingui; Altman, Ryan A

2015-08-21

Trifluoroethylarenes are found in a variety of biologically active molecules, and strategies for accessing this substructure are important for developing therapeutic candidates and biological probes. Trifluoroethylarenes can be directly accessed via nucleophilic trifluoromethylation of benzylic electrophiles; however, current catalytic methods do not effectively transform electron-deficient substrates and heterocycles. To address this gap, we report a Cu-catalyzed decarboxylative trifluoromethylation of benzylic bromodifluoroacetates. To account for the tolerance of sensitive functional groups, we propose an inner-sphere mechanism of decarboxylation.

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.

De Novo Synthesis of Benzenoid Compounds by the Yeast Hanseniaspora vineae Increases the Flavor Diversity of Wines.

PubMed

Martin, Valentina; Giorello, Facundo; Fariña, Laura; Minteguiaga, Manuel; Salzman, Valentina; Boido, Eduardo; Aguilar, Pablo S; Gaggero, Carina; Dellacassa, Eduardo; Mas, Albert; Carrau, Francisco

2016-06-08

Benzyl alcohol and other benzenoid-derived metabolites of particular importance in plants confer floral and fruity flavors to wines. Among the volatile aroma components in Vitis vinifera grape varieties, benzyl alcohol is present in its free and glycosylated forms. These compounds are considered to originate from grapes only and not from fermentative processes. We have found increased levels of benzyl alcohol in red Tannat wine compared to that in grape juice, suggesting de novo formation of this metabolite during vinification. In this work, we show that benzyl alcohol, benzaldehyde, p-hydroxybenzaldehyde, and p-hydroxybenzyl alcohol are synthesized de novo in the absence of grape-derived precursors by Hanseniaspora vineae. Levels of benzyl alcohol produced by 11 different H. vineae strains were 20-200 times higher than those measured in fermentations with Saccharomyces cerevisiae strains. These results show that H. vineae contributes to flavor diversity by increasing grape variety aroma concentration in a chemically defined medium. Feeding experiments with phenylalanine, tryptophan, tyrosine, p-aminobenzoic acid, and ammonium in an artificial medium were tested to evaluate the effect of these compounds either as precursors or as potential pathway regulators for the formation of benzenoid-derived aromas. Genomic analysis shows that the phenylalanine ammonia-lyase (PAL) and tyrosine ammonia lyase (TAL) pathways, used by plants to generate benzyl alcohols from aromatic amino acids, are absent in the H. vineae genome. Consequently, alternative pathways derived from chorismate with mandelate as an intermediate are discussed.

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.

First LNG from North field overcomes feed, start-up problems

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

Redha, A.; Rahman, A.; Al-Thani, N.H.

Qatar Gas LNG is the first LNG project in the gas-development program of the world`s largest gas reservoir, North field. The LNG plant was completed within the budget and schedule. The paper discusses the LNG plant design, LNG storage and loading, alternative mercaptan removal, layout modification, information and control systems, training, data management systems, start-up, and performance testing.

Morphological study of polymethyl methacrylate microcapsules filled with self-healing agents

NASA Astrophysics Data System (ADS)

Ahangaran, Fatemeh; Hayaty, Mehran; Navarchian, Amir H.

2017-03-01

Polymethyl methacrylate (PMMA) microcapsules filled with epoxy prepolymer, 3-aminomethyl-3,5,5-trimethylcyclohexylamine, and pentaerythritol tetrakis (3-mercaptopropionate) as healing agents have been prepared separately through internal phase separation method for self-healing purposes. PMMA with two different molecular weights (M bar1 = 36,000 g/mol and M bar2 = 550,000 g/mol) were used with two types of different emulsifiers (ionic and polymeric) to prepare microcapsules. The morphology of healing agent microcapsules was investigated using field emission scanning electron microscopy (FESEM). It was found that PMMA microcapsules separately filled with epoxy and amine had core-shell morphologies with smooth surfaces. The mercaptan/PMMA particles exhibited core-shell and acorn-shape morphologies. The surface morphology of mercaptan microcapsules changed from holed to plain in different emulsion systems. The spreading coefficient (S) of phases in the prepared emulsion systems were calculated from interfacial tension (σ) and contact angle (θ) measurements. The theoretical equilibrium morphology of PMMA microcapsules was predicted according to spreading coefficient values of phases in emulsion systems. It was also found that the surface morphology of PMMA microcapsules depended strongly on the nature of the core, molecular weight of PMMA, type and concentration of emulsifier.

Effects of aeration and leachate recirculation on methyl mercaptan emissions from landfill.

PubMed

Zhang, Siyuan; Long, Yuyang; Fang, Yuan; Du, Yao; Liu, Weijia; Shen, Dongsheng

2017-10-01

The issue of odorous volatile organic sulfur compound methyl mercaptan (MM) released from landfill sites cannot be ignored for its extremely low odor threshold and high toxicity. In this study, we focused on the formation and emission of MM in four lab-scaled simulated landfill reactors running in different operation modes, namely, R1 and R2, without leachate recirculation, running under anaerobic and semi-aerobic atmosphere, R3 and R4, with leachate recirculation, running under anaerobic and semi-aerobic atmosphere, respectively. From the perspective of odor abatement, the semi-aerobic operation mode can efficiently lower the emitted MM concentration by 87.4-94.9%, relative to the semi-aerobic operation mode. Furthermore, under semi-aerobic conditions, leachate recirculation substantially shortened the period of MM influence by 12.7%, thus reducing the risk of affecting the surrounding atmospheric environment. The formation of MM was dependent on the characteristics such as the volatile fatty acid concentration and chemical oxygen demand in the leachate and sulfide concentration of the refuse. Overall, MM release can be effectively controlled with semi-aerobic operation mode and leachate recirculation. Copyright © 2017 Elsevier Ltd. All rights reserved.

Removal of H{sub 2}S, methyl macapton dimethyl sulfide and dimethyl disulfide with biofiltration

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

Singleton, B.; Milligan, D.

1996-12-31

A pilot study describes the biofiltration process control that was necessary to remove H{sub 2}S, methyl mercaptan, dimethyl sulfide, and dimethyl disulfide, when mixed in an airstream. A pilot test at a waste water treatment facility was operated over a six month period. During that time H{sub 2}S was removed with very high efficiency at concentrations that reached to 400 ppm{sub v}; H{sub 2}S loading reached as high as 20 gms/m{sup 3}/hr. Methyl mercaptan and the organic sulfides were not removed sufficiently to deodorize the air-stream until a second stage biofilter was added. An odor analysis indicated that the odormore » detection level was approximately 250,000 odor units at the inlet and 1100 odor units at the outlet. The sulfur distribution in the media indicated that elemental sulfur and sulfate is deposited as a byproduct of the H{sub 2}S oxidation. Data from a fall scale biofilter treating H{sub 2}S from a pumping station is also presented. This data shows very efficient removal of H{sub 2}S, no organic reduced sulfur compounds were found in this air-stream.« less

Direct nuclear magnetic resonance observation of odorant binding to mouse odorant receptor MOR244-3.

PubMed

Burger, Jessica L; Jeerage, Kavita M; Bruno, Thomas J

2016-06-01

Mammals are able to perceive and differentiate a great number of structurally diverse odorants through the odorant's interaction with odorant receptors (ORs), proteins found within the cell membrane of olfactory sensory neurons. The natural gas industry has used human olfactory sensitivity to sulfur compounds (thiols, sulfides, etc.) to increase the safety of fuel gas transport, storage, and use through the odorization of this product. In the United States, mixtures of sulfur compounds are used, but the major constituent of odorant packages is 2-methylpropane-2-thiol, also known as tert-butyl mercaptan. It has been fundamentally challenging to understand olfaction and odorization due to the low affinity of odorous ligands to the ORs and the difficulty in expressing a sufficient number of OR proteins. Here, we directly observed the binding of tert-butyl mercaptan and another odiferous compound, cis-cyclooctene, to mouse OR MOR244-3 on living cells by saturation transfer difference (STD) nuclear magnetic resonance (NMR) spectroscopy. This effort lays the groundwork for resolving molecular mechanisms responsible for ligand binding and resulting signaling, which in turn will lead to a clearer understanding of odorant recognition and competition. Published by Elsevier Inc.

Novel derivatives of aclacinomycin A block cancer cell migration through inhibition of farnesyl transferase.

PubMed

Magi, Shigeyuki; Shitara, Tetsuo; Takemoto, Yasushi; Sawada, Masato; Kitagawa, Mitsuhiro; Tashiro, Etsu; Takahashi, Yoshikazu; Imoto, Masaya

2013-03-01

In the course of screening for an inhibitor of farnesyl transferase (FTase), we identified two compounds, N-benzyl-aclacinomycin A (ACM) and N-allyl-ACM, which are new derivatives of ACM. N-benzyl-ACM and N-allyl-ACM inhibited FTase activity with IC50 values of 0.86 and 2.93 μM, respectively. Not only ACM but also C-10 epimers of each ACM derivative failed to inhibit FTase. The inhibition of FTase by N-benzyl-ACM and N-allyl-ACM seems to be specific, because these two compounds did not inhibit geranylgeranyltransferase or geranylgeranyl pyrophosphate (GGPP) synthase up to 100 μM. In cultured A431 cells, N-benzyl-ACM and N-allyl-ACM also blocked both the membrane localization of H-Ras and activation of the H-Ras-dependent PI3K/Akt pathway. In addition, they inhibited epidermal growth factor (EGF)-induced migration of A431 cells. Thus, N-benzyl-ACM and N-allyl-ACM inhibited EGF-induced migration of A431 cells by inhibiting the farnesylation of H-Ras and subsequent H-Ras-dependent activation of the PI3K/Akt pathway.

Synthesis and biological studies of positron-emitting radiopharmaceuticals

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

Dischino, D.D.

The development and clinical evaluation of two-positron emitting radiopharmaceuticals designed to image myelin in humans is reported. Carbon-11-labeled benzyl methyl ether was synthesized by the reaction of carbon-11-labeled methanol and benzyl chloride in dimethyl sulfoxide containing powdered potassium hydroxide in a radiochemical yield of 43% and a synthesis and purification time of 40 minutes. Carbon-11-labeled diphenylmethanol was synthesized by the reaction of carbon-11-labeled carbon dioxide and phenyllithium followed by the reduction of the carbon-11-labeled intermediate to diphenylmethanol via lithium aluminum hydride in a radiochemical yield of 71% and a synthesis and purification time of 38 minutes. Carbon-11-labeled benzyl methyl ethermore » and diphenylmethanol were each evaluated as myelin imaging agents in three patients with multiple sclerosis via positron-emission tomography. In two out of three patients studied with carbon-11-labeled benzyl methyl ether, the distribution of activity in the brain was not consistent with local lipid content. A new synthesis of carbon-11-labeled-DL-phenylalanine labeled in the benzylic position and the synthesis of fluorine-18-labeled 1-(2-nitro-1-imidazolyl)-3-fluoro-2-propanol, a potential in vivo marker of hypoxic tissue, are reported.« less

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.

Origin of Enantioselectivity in CF3-PIP-Catalyzed Kinetic Resolution of Secondary Benzylic Alcohols

PubMed Central

Li, Ximin; Liu, Peng; Houk, K. N.; Birman, Vladimir B.

2009-01-01

Computational studies provide support for the involvement of intermolecular π–interactions in the chiral recognition of secondary benzylic alcohols by the enantioselective acyl transfer catalyst CF3-PIP. PMID:18817392

Co/NHPI-mediated aerobic oxygenation of benzylic C–H bonds in pharmaceutically relevant molecules

DOE PAGES

Hruszkewycz, Damian P.; Miles, Kelsey C.; Thiel, Oliver R.; ...

2016-10-07

A simple cobalt(II)/N-hydroxyphthalimide catalyst system has been identified for selective conversion of benzylic methylene groups in pharmaceutically relevant (hetero)arenes to the corresponding (hetero)aryl ketones. The radical reaction pathway tolerates electronically diverse benzylic C–H bonds, contrasting recent oxygenation reactions that are initiated by deprotonation of a benzylic C–H bond. The reactions proceed under practical reaction conditions (1 M substrate in BuOAc or EtOAc solvent, 12 h, 90–100 °C), and they tolerate common heterocycles, such as pyridines and imidazoles. A cobalt-free, electrochemical, NHPI-catalyzed oxygenation method overcomes challenges encountered with chelating substrates that inhibit the chemical reaction. The utility of the aerobic oxidationmore » method is showcased in the multigram synthesis of a key intermediate towards a drug candidate (AMG 579) under process-relevant reaction conditions.« less

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

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

On the role of resonantly stabilized radicals in polycyclic aromatic hydrocarbon (PAH) formation: pyrene and fluoranthene formation from benzyl-indenyl addition.

PubMed

Sinha, Sourab; Rahman, Ramees K; Raj, Abhijeet

2017-07-26

Resonantly stabilized radicals, such as propargyl, cyclopentadienyl, benzyl, and indenyl, play a vital role in the formation and growth of polycyclic aromatic hydrocarbons (PAHs) that are soot precursors in engines and flames. Pyrene is considered to be an important PAH, as it is thought to nucleate soot particles, but its formation pathways are not well known. This paper presents a reaction mechanism for the formation of four-ring aromatics, pyrene and fluoranthene, through the combination of benzyl and indenyl radicals. The intermediate species and transition structures involved in the elementary reactions of the mechanism were studied using density functional theory, and the reaction kinetics were evaluated using transition state theory. The barrierless addition of benzyl and indenyl to form the adduct, 1-benzyl-1H-indene, was found to be exothermic with a reaction energy of 204.2 kJ mol -1 . The decomposition of this adduct through H-abstraction and H 2 -loss was studied to determine the possible products. The rate-of-production analysis was conducted to determine the most favourable reactions for pyrene and fluoranthene formation. The premixed laminar flames of toluene, ethylbenzene, and benzene were simulated using a well-validated hydrocarbon fuel mechanism with detailed PAH chemistry after adding the proposed reactions to it. The computed and experimentally observed species profiles were compared to determine the effect of the new reactions for pyrene and fluoranthene formation on their concentration profiles. The role of benzyl and indenyl combination in PAH formation and growth is highlighted.

Benzyl Alcohol Topical

MedlinePlus

... lice. Benzyl alcohol lotion will not kill lice eggs, so the medication must be used a second ... kill the lice that may hatch from these eggs. ... to remove the dead lice and nits (empty egg shells) after this treatment. You may also need ...

Benzyl chloride

Integrated Risk Information System (IRIS)

Benzyl chloride ; CASRN 100 - 44 - 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 E

The Formation and Thermochemical Properties of Multiligand Complexes

DTIC Science & Technology

1987-08-25

SUBJECT TERMS (Continue on revers, if necessary and identify by block numoer) FIELD GROUP SUB-GROUP Ion-molecule reactions, clusters, multiligand...mercaptans, and phosphonates for which the results may be useful in the development of detection techniques that employ ion mobility analyzers or... field involve the use of ion mobility and mass spectrometers. Detection of a species by such instruments in an atmospheric environment requires that the

Protection of Grain Products from Sitophilus oryzae (L.) Contamination by Anti-Insect Pest Repellent Sachet Containing Allyl Mercaptan Microcapsule.

PubMed

Chang, Yoonjee; Lee, Soo-Hyun; Na, Ja Hyun; Chang, Pahn-Shick; Han, Jaejoon

2017-11-01

The purpose of this study was to develop an anti-insect pest repellent sachet to prevent Sitophilus oryzae (L.) (Coleoptera: Curculionidae) contamination in grain packaging. The anti-insect pest activities of essential oils (EOs) from garlic (Allium Sativum), ginger (Zingiber Officinalis), black pepper (Piper nigrum), onion (Allium cepa), and fennel (Foeniculum vulgare) as well as major compounds (allyl disulfide, AD; allyl mercaptan, AM) isolated from of garlic and onion (AD and AM) were measured against S. oryzae. The results revealed that garlic EO, onion EO, AD, and AM showed strong fumigant insecticidal activities. Among these, AM showed the highest acetylcholinesterase (AChE) inhibition rate, indicating that the fumigation insecticidal efficacy of AM is related with its AChE inhibition ability. Subsequently, the microcapsules were produced with a high efficiency (80.02%) by using AM as a core material and rice flour as a wall material. Finally, sachet composed of rice flour microcapsule containing 2% AM (RAM) was produced. Repellent assay was performed to measure anti-insect pest ability of the RAM sachet, showed remarkable repelling effect within 48 h both in the presence or absence of attractant. In a release profile of RAM sachet, it was expected to last over 20 mo during the distribution period of brown rice. Moreover, RAM sachet showed no undesirable changes to the sensory properties of the rice both before and after cooking. Taken together, these results suggest that the newly developed RAM sachet could be used as a packaging material to protect grain products from S. oryzae contamination. The rice weevil, Sitophilus oryzae (L.) (Coleoptera: Curculionidae), causes damages to stored products and its contamination in grain products has become a major problem in cereal market. To preserve brown rice, an anti-insect pest repellent sachet containing 2% allyl mercaptan was newly developed and it showed remarkable repellent abilities against S. oryzae. It could be used as an active food packaging system to protect grain products from insect pest contamination. © 2017 Institute of Food Technologists®.

Efficacy of a novel biofilter in hatchery sanitation: II. Removal of odorogenous pollutants.

PubMed

Tymczyna, Leszek; Chmielowiec-Korzeniowska, Anna; Drabik, Agata; Skórska, Czesława; Sitkowska, Jolanta; Cholewa, Grazyna; Dutkiewicz, Jacek

2007-01-01

The present research assessed the treatment efficiency of odorogenous pollutants in air from a hatchery hall vented on organic and organic-mineral beds of an enclosed-container biofilter. In this study, the following media were used: organic medium containing compost and peat (OM); organic-mineral medium containing bentonite, compost and peat (BM); organic-mineral medium containing halloysite, compost and peat (HM). The concentration of odorogenous gaseous pollutants (sulfur compounds and amines) in the hatching room air and in the air after biotreatment were determined by gas chromatography. In the hatchery hall among the typical odorogenous pollutants, there were determined 2 amines: 2-butanamine and 2-pentanamine, hydrogen sulfide, sulfur dioxide, carbon disulfide, sulfides and mercaptans. Ethyl mercaptan showed the highest levels as its mean concentration in the hatchery hall air exceeded 60 microg/m3 and in single samples even 800 microg/m3. A mean concentration of 2-butanamine and sulfur dioxide in the examined air also appeared to be relatively high--21.405 microg/m3 and 15.279 microg/m3, respectively. In each filter material, the air treatment process ran in a different mode. As the comparison reveals, the mean reduction of odorogenous contaminants recorded in the hall and subjected to biotreatment was satisfying as it surpassed 60% for most established pollutants. These high removal values were confirmed statistically only for single compounds. However, a low removal level was reported for hydrogen sulfide and sulfur dioxide. No reduction was recorded in the bentonite supplemented medium (BM) for sulfur dioxide and methyl mercaptan. In the organic medium (OM) no concentration fall was noted for dipropyl sulfide either. In all the media investigated, the highest removal rate (100%), not confirmed statistically, was observed for carbon disulfide. Very good results were obtained in the medium with a bentonite additive (BM) for both identified amines, whose mean elimination rate exceeded 60% (p

Butyl benzyl phthalate (BBP)

Integrated Risk Information System (IRIS)

Butyl benzyl phthalate ; CASRN 85 - 68 - 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 Noncarcinog

Benzylation of Nitroalkanes Using Copper-Catalyzed Thermal Redox Catalysis: Toward the Facile C-Alkylation of Nitroalkanes

PubMed Central

Gildner, Peter G.; Gietter, Amber A. S.; Cui, Di; Watson, Donald A.

2012-01-01

The C-alkylation of nitroalkanes under mild conditions has been a significant challenge in organic synthesis for more than a century. Herein, we report a simple Cu(I) catalyst, generated in situ, that is highly effective for C-benzylation of nitroalkanes using abundant benzyl bromides and related heteroaromatic compounds. This process, which we believe proceeds via a thermal redox mechanism, allows access to a variety of complex nitroalkanes under mild reaction conditions and represents the first step towards developing a general catalytic system for the alkylation of nitroalkanes. PMID:22691127

Jasminum flexile flower absolute from India--a detailed comparison with three other jasmine absolutes.

PubMed

Braun, Norbert A; Kohlenberg, Birgit; Sim, Sherina; Meier, Manfred; Hammerschmidt, Franz-Josef

2009-09-01

Jasminum flexile flower absolute from the south of India and the corresponding vacuum headspace (VHS) sample of the absolute were analyzed using GC and GC-MS. Three other commercially available Indian jasmine absolutes from the species: J. sambac, J. officinale subsp. grandiflorum, and J. auriculatum and the respective VHS samples were used for comparison purposes. One hundred and twenty-one compounds were characterized in J. flexile flower absolute, with methyl linolate, benzyl salicylate, benzyl benzoate, (2E,6E)-farnesol, and benzyl acetate as the main constituents. A detailed olfactory evaluation was also performed.

Intradermal bacteriostatic 0.9% sodium chloride containing the preservative benzyl alcohol compared with intradermal lidocaine hydrochloride 1% for attenuation of intravenous cannulation pain.

PubMed

McNelis, K A

1998-12-01

This study compared the efficacy of a common medication diluent, bacteriostatic 0.9% sodium chloride containing the preservative benzyl alcohol with lidocaine hydrochloride 1% as an intradermal pretreatment for the relief of pain associated with intravenous cannulation. Forty adult presurgical patients requiring two large bore intravenous catheters were used. They served as their own controls. The inner aspect of one forearm received the usual pretreatment, lidocaine hydrochloride 1%, and the inner aspect of the opposite arm received intradermal pretreatment with bacteriostatic 0.9% sodium chloride with the preservative benzyl alcohol. Intravenous cannulation was accomplished on the first attempt, and pain reported with cannulation was rated using a visual analogue scale (VAS). A paired t test was used to compare differences in VAS scores with the pretreatment bacteriostatic 0.9% sodium chloride containing the preservative benzyl alcohol with the pretreatment lidocaine hydrochloride 1%. Analysis of the data revealed no significant difference in the report of perceived pain of intravenous cannulation based on the intradermal pretreatment. These findings suggest that intradermal bacteriostatic 0.9% sodium chloride containing the preservative benzyl alcohol is as effective as intradermal lidocaine hydrochloride 1% in the attenuation of intravenous cannulation pain.

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

Transition metal complexes supported on metal-organic frameworks for heterogeneous catalysts

DOEpatents

Farha, Omar K.; Hupp, Joseph T.; Delferro, Massimiliano; Klet, Rachel C.

2017-02-07

A robust mesoporous metal-organic framework comprising a hafnium-based metal-organic framework and a single-site zirconium-benzyl species is provided. The hafnium, zirconium-benzyl metal-organic framework is useful as a catalyst for the polymerization of an alkene.

The thermal decomposition of the benzyl radical in a heated micro-reactor. I. Experimental findings

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

Buckingham, Grant T.; Ormond, Thomas K.; National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, Colorado 80401

2015-01-28

The pyrolysis of the benzyl radical has been studied in a set of heated micro-reactors. A combination of photoionization mass spectrometry (PIMS) and matrix isolation infrared (IR) spectroscopy has been used to identify the decomposition products. Both benzyl bromide and ethyl benzene have been used as precursors of the parent species, C{sub 6}H{sub 5}CH{sub 2}, as well as a set of isotopically labeled radicals: C{sub 6}H{sub 5}CD{sub 2}, C{sub 6}D{sub 5}CH{sub 2}, and C{sub 6}H{sub 5}{sup 13}CH{sub 2}. The combination of PIMS and IR spectroscopy has been used to identify the earliest pyrolysis products from benzyl radical as: C{sub 5}H{submore » 4}=C=CH{sub 2}, H atom, C{sub 5}H{sub 4}—C ≡ CH, C{sub 5}H{sub 5}, HCCCH{sub 2}, and HC ≡ CH. Pyrolysis of the C{sub 6}H{sub 5}CD{sub 2}, C{sub 6}D{sub 5}CH{sub 2}, and C{sub 6}H{sub 5}{sup 13}CH{sub 2} benzyl radicals produces a set of methyl radicals, cyclopentadienyl radicals, and benzynes that are not predicted by a fulvenallene pathway. Explicit PIMS searches for the cycloheptatrienyl radical were unsuccessful, there is no evidence for the isomerization of benzyl and cycloheptatrienyl radicals: C{sub 6}H{sub 5}CH{sub 2}⇋C{sub 7}H{sub 7}. These labeling studies suggest that there must be other thermal decomposition routes for the C{sub 6}H{sub 5}CH{sub 2} radical that differ from the fulvenallene pathway.« less

1-Benzyl-indole-3-carbinol is a novel indole-3-carbinol derivative with significantly enhanced potency of anti-proliferative and anti-estrogenic properties in human breast cancer cells

PubMed Central

Nguyen, Hanh H.; Lavrenov, Sergey N.; Sundar, Shyam N.; Nguyen, David H.H.; Tseng, Min; Marconett, Crystal N.; Kung, Jenny; Staub, Richard E.; Preobrazhenskaya, Maria N.; Bjeldanes, Leonard F.; Firestone, Gary L.

2012-01-01

Indole-3-carbinol (I3C), a natural autolysis product of a gluccosinolate present in Brassica vegetables such as broccoli and cabbage, has anti-proliferative and anti-estrogenic activities in human breast cancer cells. A new and significantly more potent I3C analogue, 1-benzyl-I3C was synthesized, and in comparison to I3C, this novel derivative displayed an approximate 1000-fold enhanced potency in suppressing the growth of both estrogen responsive (MCF-7) and estrogen independent (MDA-MB-231) human breast cancer cells (I3C IC50 of 52 μM, and 1-benzyl-I3C IC50 of 0.05 μM). At significantly lower concentrations, 1-benzyl-I3C induced a robust G1 cell cycle arrest and elicited the key I3C-specific effects on expression and activity of G1 acting cell cycle genes including the disruption of endogenous interactions of the Sp1 transcription factor with the CDK6 promoter. Furthermore, in estrogen responsive MCF-7 cells, with enhanced potency 1-benzyl-I3C down regulated production of estrogen receptor-alpha protein, acts with tamoxifen to arrest breast cancer cell growth more effectively than either compound alone, and inhibited the in vivo growth of human breast cancer cell-derived tumor xenografts in athymic mice. Our results implicate 1-benzyl-I3C as a novel, potent inhibitor of human breast cancer proliferation and estrogen responsiveness that could potentially be developed into a promising therapeutic agent for the treatment of indole-sensitive cancers. PMID:20570586

Origin of the SN2 benzylic effect.

PubMed

Galabov, Boris; Nikolova, Valia; Wilke, Jeremiah J; Schaefer, Henry F; Allen, Wesley D

2008-07-30

The S N2 identity exchange reactions of the fluoride ion with benzyl fluoride and 10 para-substituted derivatives (RC6H 4CH 2F, R = CH3, OH, OCH 3, NH2, F, Cl, CCH, CN, COF, and NO2) have been investigated by both rigorous ab initio methods and carefully calibrated density functional theory. Groundbreaking focal-point computations were executed for the C6H5CH 2F + F (-) and C 6H 5CH2Cl + Cl (-) SN2 reactions at the highest possible levels of electronic structure theory, employing complete basis set (CBS) extrapolations of aug-cc-pV XZ (X = 2-5) Hartree-Fock and MP2 energies, and including higher-order electron correlation via CCSD/aug-cc-pVQZ and CCSD(T)/aug-cc-pVTZ coupled cluster wave functions. Strong linear dependences are found between the computed electrostatic potential at the reaction-center carbon atom and the effective SN2 activation energies within the series of para-substituted benzyl fluorides. An activation strain energy decomposition indicates that the SN2 reactivity of these benzylic compounds is governed by the intrinsic electrostatic interaction between the reacting fragments. The delocalization of nucleophilic charge into the aromatic ring in the SN2 transition states is quite limited and should not be considered the origin of benzylic acceleration of SN2 reactions. Our rigorous focal-point computations validate the benzylic effect by establishing SN2 barriers for (F (-), Cl (-)) identity exchange in (C6H5CH2F, C6H 5CH2Cl) that are lower than those of (CH3F, CH3Cl) by (3.8, 1.6) kcal mol (-1), in order.

40 CFR 464.11 - Specialized definitions.

Code of Federal Regulations, 2014 CFR

2014-07-01

.... fluoranthene 44. methylene chloride (dichloromethane) 65. phenol 66. bis(2-ethylhexyl) phthalate 67. butyl benzyl phthalate 84. pyrene 85. tetrachloroethylene 87. trichloroethylene (2) Die Casting (§ 464.15(c...) phthalate 67. butyl benzyl phthalate 68. di-n-butyl phthalate 70. diethyl phthalate 72. benzo (a)anthracene...

40 CFR 464.11 - Specialized definitions.

Code of Federal Regulations, 2012 CFR

2012-07-01

.... fluoranthene 44. methylene chloride (dichloromethane) 65. phenol 66. bis(2-ethylhexyl) phthalate 67. butyl benzyl phthalate 84. pyrene 85. tetrachloroethylene 87. trichloroethylene (2) Die Casting (§ 464.15(c...) phthalate 67. butyl benzyl phthalate 68. di-n-butyl phthalate 70. diethyl phthalate 72. benzo (a)anthracene...

Comparison of pain response after subcutaneous injection of two maropitant formulations to beagle dogs.

PubMed

Deckers, Nynke; Ruigrok, Catharina A; Verhoeve, Hans Peter; Lourens, Nicky

2018-01-01

The antiemetic maropitant, with metacresol as preservative (Cerenia, Zoetis), has been associated with pain after subcutaneous injection in dogs and cats. Recently, a generic formulation containing benzyl alcohol was authorised (Prevomax, Le Vet). Benzyl alcohol is reported to have local anaesthetic properties and reduce injection pain. This study compared local pain after subcutaneous injection of the two maropitant formulations, administered at approximately 4°C and 25°C, to dogs. Thirty-two healthy beagle dogs were enrolled into a blinded, randomised, cross-over study. Dogs received subcutaneous injections of maropitant injection containing metacresol as preservative and maropitant injection containing benzyl alcohol as preservative, both at approximately 4°C and 25°C, with at least three days in between treatments. Injection pain was evaluated by two blinded observers using a visual analogue scale immediately after injection and a simple descriptive scale at two minutes after injection. In healthy beagle dogs, subcutaneous injection of maropitant with benzyl alcohol is significantly less painful than injection of maropitant with metacresol.

Environmentally benign Friedel-Crafts benzylation over nano-TiO2/SO4 2-

NASA Astrophysics Data System (ADS)

Devi, Kalathiparambil RPS; Sreeja, Puthenveetil B.; Sugunan, Sankaran

2013-05-01

During the past decade, much attention has been paid to the replacement of homogeneous catalysts by solid acid catalysts. Friedel-Crafts benzylation of toluene with benzyl chloride (BC) in liquid phase was carried out over highly active, nano-crystalline sulfated titania systems. These catalysts were prepared using the sol gel method. Modification was done by loading 3% of transition metal oxides over sulfated titania. Reaction parameters such as catalyst mass, molar ratio, temperature, and time have been studied. More than 80% conversion of benzyl chloride and 100% selectivity are shown by all the catalysts under optimum conditions. Catalytic activity is correlated with Lewis acidity obtained from perylene adsorption studies. The reaction appears to proceed by an electrophile, which involves the reaction of BC with the acidic titania catalyst. The catalyst was regenerated and reused up to four reaction cycles with equal efficiency as in the first run. The prepared systems are environmentally friendly and are easy to handle.

Estimation of Free Radical Ionization Energies by the Kinetic Method and the Relationship between the Kinetic Method and the Hammett Equation.

PubMed

Chen, G; Wong, P; Cooks, R G

1997-09-01

Substituted 1,2-diphenylethanes undergo competitive dissociations upon electron ionization (EI) to generate substituted benzyl cation and benzyl radical pairs. Application of the kinetic method to the previous reported EI mass spectra of these covalently bound precursor ions (data are taken from McLafferty et al. J. Am. Chem. Soc. 1970, 92, 6867)) is used to estimate the ionization energies of substituted benzyl free radicals. A correlation is observed between the Hammett σ constant of the substituents and the kinetic method parameter, ln(k(x)/k(H)), where k(x) is the rate of fragmentation to give the substituted product ion and k(H) is the rate to give the benzyl ion itself. Systems involving weakly bound cluster ions, including proton-bound dimers of meta- and para-substituted pyridines and meta- and para-substituted anilines, and electron-bound dimers of meta- and para-substituted nitrobenzenes, also show good correlations between the kinetic method parameter and the Hammett σ constant.

Jet-Cooled Chlorofluorobenzyl Radicals: Spectroscopy and Mechanism

NASA Astrophysics Data System (ADS)

Yoon, Young; Lee, Sang

2016-06-01

Whereas the benzyl radical, a prototypic aromatic free radical, has been the subject of numerous spectroscopic studies, halo-substituted benzyl radicals have received less attention, due to the difficulties associated with production of radicals from precursors. In particular, chloro-substituted benzyl radicals have been much less studied because of the weak visible emission intensity and weak C-Cl bond dissociation energy. The jet-cooled chlorofluorobenzyl radicals were generated in a technique of corona excited supersonic jet expansion using a pinhole-type glass nozzle for the vibronic assignments and measurements of electronic energies of the D_1 → D_0 transition. The 2,4-,2.5-, and 2.6- chlorofluorobenzyl radicals were generated by corona discharge of corresponding precursors, chlorofluorotoluenes seeded in a large amount of helium carrier gas. The vibronic emission spectra were recorded with a long-path monochromator in the visible region. The emission spectra show the vibronic bands originating from two types of benzyl-type radicals, chlorofluorobenzyl and fluorobenzyl benzyl radicals, in which fluorobenzyl radicals were obtained by displacement of Cl by H produced by dissociation of methyl C-H bond. From the analysis of the spectra observed, we could determine the electronic energies in D_1 → D_0 transition and vibrational mode frequencies at the D_0 state of chlorofluorobenzyl radicals, which show the origin band of the electronic transition to be shifted to red region, comparing with the parental benzyl radical. From the quantitative analysis of the red-shift, it has been found that the additivity rule can be applied to dihalo-substituted benzyl radicals. In this presentation, the dissociation process of precursors in corona discharge is discussed in terms of bond dissociation energy as well as the spectroscopic analysis of the radicals. C. S. Huh, Y. W. Yoon, and S. K. Lee, J. Chem. Phys. 136, 174306 (2012). Y. W. Huh, S. Y. Chae, and S. K. Lee, Chem. Phys. Lett. 608, 6 (2014). Y. W. Yoon, S. Y. Chae, M. Lim, and S. K. Lee, Chem. Phys. Lett. 637, 148 (2015).

NTP Toxicology and Carcinogenesis Studies of Benzyl Acetate (CAS No. 140-11-4) in F344/N Rats and B6C3F1 Mice (Gavage Studies).

PubMed

1986-08-01

Benzyl acetate, a water-white liquid with a pear-like odor, is a natural constituent of several essential oils and flower absolutes extracted from jasmine, hyacinth, gardenia, tuberose, ylang-ylang, cananga, and neroli. Commercial benzyl acetate, a liquid prepared synthetically from benzyl chloride, acetic acid, and triethylamine is used primarily as a component of perfumes for soaps and as a flavoring ingredient. This compound is practically insoluble in water but is miscible in alcohol and ether and soluble in benzene and chloroform. Toxicology and carcinogenesis studies of benzyl acetate (>99% pure) were conducted by administering benzyl acetate in corn oil gavage to groups of 50 male and 50 female F344/N rats at doses of 0, 250, or 500 mg/kg body weight and to groups of 50 male and 50 female B6C3F1 mice at doses of 0, 500, or 1,000 mg/kg once daily five days per week for 103 weeks. Dose selection for the 2-year study was based on mean body weight gain depression and decreased survival observed at higher doses in 13 week studies. The absence of any observable adverse effect of benzyl acetate on the survival or mean body weight gains of the rats or mice in the 2-year studies suggests that both the rats and the mice of each sex could have tolerated higher doses. An infection in the genital tract was probably responsible for the deaths of 26/35 control, 14/32 low-dose, and 8/20 high-dose female mice before the end of the study. Acinar-cell adenomas in the pancreas of male rats occurred with a positive trend (P<0.01), and the incidence in the high-dose group (37/49, 76%) was significantly (P<0.01) higher than in the vehicle controls (22/50, 40%). The incidence of these tumors in the low-dose group (27/50, 54%) was comparable to that in the gavage controls. Acinar-cell hyperplasia of the pancreas was observed in 37/50 control, 34/50 low-dose, and 36/49 high-dose male rats. No acinar-cell hyperplasia or adenoma of the pancreas was observed in female rats. The incidence of retinopathy and cataracts in the high-dose male rats was increased compared with the controls (retinopathy: 1/50; 0/50; 20/50; cataracts: 0/50; 0/50; 13/50). Low-dose female rats had an increased incidence of retinopathy (18/50). Retinopathy and cataracts in rats have been associated with proximity to fluorescent light in this and previous studies. Preputial gland neoplasms occurred with a positive trend (P<0.05) in male rats (cystadenocarcinoma: 0/50; 0/50; 3/50; all adenocarcinoma: 0/50; 1/50; 4/50; adenocarcinoma or carcinoma combined: 1/50; 1/50; 6/50). However, the incidence of all preputial gland tumors was not significantly elevated (2/50; 1/50; 6/50). For female rats the incidence of clitoral gland neoplasms was marginally increased (2/50; 0/50; 5/50). Hepatocellular adenomas occurred in mice of each sex with statistically positive trends (males: 0/50; 5/49; 13/50; females: 0/50; 0/50; 6/50), and the incidences in the high-dose groups were greater than those in the controls (males: P<0.001; females: P<0.05). Hepatocellular carcinomas were marginally elevated in dosed male and high-dose female mice (males: 10/50; 14/49; 12/50; females: 1/50; 0/50; 4/50). Squamous cell papillomas or carcinomas of the forestomach (uncommon neoplasms) occurred with a positive trend (P<0.05) in male mice (4/49; 4/48; 11/49). The incidence of these tumors was also marginally (P=0.054) increased in the high-dose female mice (0/50; 0/50; 4/48). The incidences of these tumors in both the high-dose male and the high-dose female mice were considerably higher than the historical corn oil gavage control rates at this laboratory (males, 2/296, 0.7%; females, 2/297, 0.7%) and throughout the program (males, 14/1,070, 1.3%; females, 3/1,073, 0.3%). Forestomach hyperplasia occurred at increased incidences in dosed mice of either sex (males: 1/49, 7/48, 22/49; females: 1/50, 6/50, 17/48). The neoplasms and hyperplasia of the forestomach were probably related to administration of benzyl acetate. In a separate metabolism study, benzyl acetate was absorbed from the gastrointestinal traolism study, benzyl acetate was absorbed from the gastrointestinal tract of rats and mice, with approximately 90% of the administered dose recovered as various metabolites in the urine within 24 hr. The primary metabolite was hippuric acid, with minor amounts of a mercapturic acid, and one or more unidentified metabolites. This capacity for absorption, metabolism, and disposition was unaffected by the amount or number of doses administered. Benzyl acetate was not mutagenic in strains TA100, TA98, TA135, or TA137 of Salmonella typhimurium in the presence or absence of Aroclor 1254-induced Sprague-Dawley rat or Syrian hamster S9 when tested according to the preincubation protocol. Benzyl acetate did not induce sister-chromatid exchanges or chromosomal aberrations in Chinese hamster ovary cells in the presence or absence of Aroclor 1254-induced Sprague-Dawley rat liver S9. Benzyl acetate was mutagenic in the mouse lymphoma L5178Y/TK± assay in the presence, but not in the absence, of Aroclor 1254-induced Fisher 344 rat liver S9. An audit was conducted on the experimental data and the draft technical report for these 2-year studies on benzyl acetate. Based on the results of this audit additional pathology examinations were conducted on all target organs in male rats and male and female mice. The Technical Report reflects these final pathology evaluations. The overall conclusions regarding the toxicology and carcinogenicity of benzyl acetate did not change as a result of this evaluation. Under the conditions of these gavage studies, benzyl acetate increased the incidence of acinar-cell adenomas of the exocrine pancreas in male F344/N rats; the gavage vehicle may have been a contributing factor. There was no evidence of carcinogenicity for female F344/N rats. For male and female B6C3F1 mice there was some evidence of carcinogenicity in that benzyl acetate caused increased incidences of hepatocellular adenomas and squamous cell neoplasms of the forestomach. Synonyms: alpha-acetoxytoluene; benzyl ethanoate; acetic acid, benzyl ester

Studies on the effects of gamma radiation on 6-aminopenicillanic acid and its derivatives by the EPR method

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

Dziegielewski, J.; Jezowska-Trzebiatowska, B.; Kozlowski, H.

Commercial samples of 6-aminopenicillanic acid (6-APA), potassium benzyl- penicillin; procaine benzyl-penicillin, procaine hydrochlorides and sodium 3-(o- chlorophenyl)-5-methyl-4-isoxasol penicillin salt were irradiated with 0.5 to 40 Mrad and examined by the EPR method within the temperature range 100 to 300 deg K. No influence of the irradiation dose on powder EPR spectra structure has been stated, except for benzyl-penicillin procaine. In irradiated samples of antibiotics the presence of radicals with unpaired electrons on sulfur atoms and carbon atoms abuttmg on the thioether group has been stated. (auth)

Selective Electrocatalytic Degradation of Odorous Mercaptans Derived from S-Au Bond Recongnition on a Dendritic Gold/Boron-Doped Diamond Composite Electrode.

PubMed

Chai, Shouning; Wang, Yujing; Zhang, Ya-Nan; Liu, Meichuan; Wang, Yanbin; Zhao, Guohua

2017-07-18

To improve selectivity of electrocatalytic degradation of toxic, odorous mercaptans, the fractal-structured dendritic Au/BDD (boron-doped diamond) anode with molecular recognition is fabricated through a facile replacement method. SEM and TEM characterizations show that the gold dendrites are single crystals and have high population of the Au (111) facet. The distinctive structure endows the electrode with advantages of low resistivity, high active surface area, and prominent electrocatalytic activity. To evaluate selectivity, the dendritic Au/BDD is applied in degrading two groups of synthetic wastewater containing thiophenol/2-mercaptobenzimidazole (targets) and phenol/2-hydroxybenzimidazole (interferences), respectively. Results show that targets removals reach 91%/94%, while interferences removals are only 58%/48% in a short time. The corresponding degradation kinetic constants of targets are 3.25 times and 4.1 times that of interferences in the same group, demonstrating modification of dendritic gold on BDD could effectively enhance electrocatalytic target-selectivity. XPS and EXAFS further reveal that the selective electrocatalytic degradation derives from preferential recognition and fast adsorption to thiophenol depending on strong Au-S bond. The efficient, selective degradation is attributed to the synergetic effects between accumulative behavior and outstanding electrochemical performances. This work provides a new strategy for selective electrochemical degradation of contaminants for actual wastewater treatment.

Effect of milk on the deodorization of malodorous breath after garlic ingestion.

PubMed

Hansanugrum, Areerat; Barringer, Sheryl A

2010-08-01

The effect of milk and milk components on the deodorization of diallyl disulfide (DADS), allyl methyl disulfide (AMDS), allyl mercaptan (AM), allyl methyl sulfide (AMS), and methyl mercaptan (MM) in the headspace of garlic as well as in the mouth- and nose-space after garlic ingestion was investigated using selected ion flow tube-mass spectrometry (SIFT-MS). Fat-free and whole milk significantly reduced the head-, mouth-, and nose-space concentrations of all volatiles. Water was the major component in milk responsible for the deodorization of volatiles. Due to its higher fat content, whole milk was more effective than fat-free milk in the deodorization of the more hydrophobic volatiles diallyl disulfide and allyl methyl disulfide. Milk was more effective than water and 10% sodium caseinate in the deodorization of allyl methyl sulfide, a persistent garlic odor, in the mouth after garlic ingestion. Addition of milk to garlic before ingestion had a higher deodorizing effect on the volatiles in the mouth than drinking milk after consuming garlic. Practical Application: Ingesting beverages or foods with high water and/or fat content such as milk may help reduce the malodorous odor in breath after garlic ingestion and mask the garlic flavor during eating. To enhance the deodorizing effect, deodorant foods should be mixed with garlic before ingestion.

"Decarbonization" of an imino N-heterocyclic carbene via triple benzyl migration from hafnium

USDA-ARS?s Scientific Manuscript database

An imino N-heterocyclic carbene underwent three sequential benzyl migrations upon reaction with tetrabenzylhafnium, resulting in complete removal of the carbene carbon from the ligand. The resulting eneamido-amidinato hafnium complex showed alkene polymerization activity comparable to that of a prec...

40 CFR 464.11 - Specialized definitions.

Code of Federal Regulations, 2011 CFR

2011-07-01

... (dichloromethane) 65. phenol 66. bis(2-ethylhexyl) phthalate 67. butyl benzyl phthalate 84. pyrene 85... 65. phenol 66. bis(2-ethylhexyl) phthalate 67. butyl benzyl phthalate 68. di-n-butyl phthalate 70...) 65. phenol 66. bis (2-ethylhexyl) phthalate 68. di-n-butyl phthalate 70. diethyl phthalate 73. benzo...

5-Alkyl-6-benzyl-2-(2-oxo-2-phenylethylsulfanyl)pyrimidin-4(3H)-ones, a series of anti-HIV-1 agents of the dihydro-alkoxy-benzyl-oxopyrimidine family with peculiar structure-activity relationship profile.

PubMed

Nawrozkij, Maxim B; Rotili, Dante; Tarantino, Domenico; Botta, Giorgia; Eremiychuk, Alexandre S; Musmuca, Ira; Ragno, Rino; Samuele, Alberta; Zanoli, Samantha; Armand-Ugón, Mercedes; Clotet-Codina, Imma; Novakov, Ivan A; Orlinson, Boris S; Maga, Giovanni; Esté, José A; Artico, Marino; Mai, Antonello

2008-08-14

A series of dihydro-alkylthio-benzyl-oxopyrimidines (S-DABOs) bearing a 2-aryl-2-oxoethylsulfanyl chain at pyrimidine C2, an alkyl group at C5, and a 2,6-dichloro-, 2-chloro-6-fluoro-, and 2,6-difluoro-benzyl substitution at C6 (oxophenethyl- S-DABOs, 6-8) is here described. The new compounds showed low micromolar to low nanomolar (in one case subnanomolar) inhibitory activity against wt HIV-1. Against clinically relevant HIV-1 mutants (K103N, Y181C, and Y188L) as well as in enzyme (wt and K103N, Y181I, and L100I mutated RTs) assays, compounds carrying an ethyl/ iso-propyl group at C5 and a 2,6-dichloro-/2-chloro-6-fluoro-benzyl moiety at C6 were the most potent derivatives, also characterized by low fold resistance ratio. Interestingly, the structure-activity relationship (SAR) data drawn from this DABO series are more related to HEPT than to DABO derivatives. These findings were at least in part rationalized by the description of a fair superimposition between the 6-8 and TNK-651 (a HEPT analogue) binding modes in both WT and Y181C RTs.

The antimalarial activities of methylene blue and the 1,4-naphthoquinone 3-[4-(trifluoromethyl)benzyl]-menadione are not due to inhibition of the mitochondrial electron transport chain.

PubMed

Ehrhardt, Katharina; Davioud-Charvet, Elisabeth; Ke, Hangjun; Vaidya, Akhil B; Lanzer, Michael; Deponte, Marcel

2013-05-01

Methylene blue and a series of recently developed 1,4-naphthoquinones, including 3-[4-(substituted)benzyl]-menadiones, are potent antimalarial agents in vitro and in vivo. The activity of these structurally diverse compounds against the human malaria parasite Plasmodium falciparum might involve their peculiar redox properties. According to the current theory, redox-active methylene blue and 3-[4-(trifluoromethyl)benzyl]-menadione are "subversive substrates." These agents are thought to shuttle electrons from reduced flavoproteins to acceptors such as hemoglobin-associated or free Fe(III)-protoporphyrin IX. The reduction of Fe(III)-protoporphyrin IX could subsequently prevent essential hemoglobin digestion and heme detoxification in the parasite. Alternatively, owing to their structures and redox properties, methylene blue and 1,4-naphthoquinones might also affect the mitochondrial electron transport chain. Here, we tested the latter hypothesis using an established system of transgenic P. falciparum cell lines and the antimalarial agents atovaquone and chloroquine as controls. In contrast to atovaquone, methylene blue and 3-[4-(trifluoromethyl)benzyl]-menadione do not inhibit the mitochondrial electron transport chain. A systematic comparison of the morphologies of drug-treated parasites furthermore suggests that the three drugs do not share a mechanism of action. Our findings support the idea that methylene blue and 3-[4-(trifluoromethyl)benzyl]-menadione exert their antimalarial activity as redox-active subversive substrates.

DFT study of benzyl alcohol/TiO2 interfacial surface complex: reaction pathway and mechanism of visible light absorption.

PubMed

Zhao, Lei; Gu, Feng Long; Kim, Minjae; Miao, Maosheng; Zhang, Rui-Qin

2017-09-24

We propose a new pathway for the adsorption of benzyl alcohol on the surface of TiO 2 and the formation of interfacial surface complex (ISC). The reaction free energies and reaction kinetics were thoroughly investigated by density functional calculations. The TiO 2 surfaces were modeled by clusters consisting of 4 Ti atoms and 18 O atoms passivated by H, OH group and H 2 O molecules. Compared with solid-state calculations utilizing the periodicity of the materials, such cluster modeling allows inclusion of the high-order correlation effects that seem to be essential for the adsorption of organic molecules onto solid surfaces. The effects of both acidity and solvation are included in our calculations, which demonstrate that the new pathway is competitive with a previous pathway. The electronic structure calculations based on the relaxed ISC structures reveal that the chemisorption of benzyl alcohol on the TiO 2 surface greatly alters the nature of the frontier molecular orbitals. The resulted reduced energy gap in ISC matches the energy of visible light, showing how the adsorption of benzyl alcohol sensitizes the TiO 2 surface. Graphical Abstract The chemisorption of benzyl alcohol on TiO 2 surface greatly alters the nature of the frontier molecular orbitals and the formed interfacial surface complex can be sensitized by visible light.

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...

40 CFR 464.31 - Specialized definitions.

Code of Federal Regulations, 2011 CFR

2011-07-01

... (dichloromethane) 55. naphthalene 64. pentachlorophenol 65. phenol 66. bis(2-ethylhexyl)phthalate 67. butyl benzyl phthalate 68. di-n-butyl phthalate 70. diethyl phthalate 71. dimethyl phthalate 72. benzo (a)anthracene (1,2...-ethylhexyl) phthalate 67. butyl benzyl phthalate 68. di-n-butyl phthalate 72. benzo (a)anthracene (1,2...

Effective oxidation of benzylic and alkane C-H bonds catalyzed by sodium o-iodobenzenesulfonate with Oxone as a terminal oxidant under phase-transfer conditions.

PubMed

Cui, Li-Qian; Liu, Kai; Zhang, Chi

2011-04-07

Catalytic oxidation of benzylic C-H bonds could be efficiently realized using IBS as a catalyst which was generated in situ from the oxidation of sodium 2-iodobenzenesulfonate (1b) by Oxone in the presence of a phase-transfer catalyst, tetra-n-butylammonium hydrogen sulfate, in anhydrous acetonitrile at 60 °C. Various alkylbenzenes, including toluenes and ethylbenzenes, several oxygen-containing functionalities substituted alkylbenzenes, and a cyclic benzyl ether could be efficiently oxidized. And, the same reagent system of cat. 1b/Oxone/cat. n-Bu(4)NHSO(4) could be applied to the effective oxidation of alkanes as well.

Sulfide chemiluminescence detection

DOEpatents

Spurlin, Stanford R.; Yeung, Edward S.

1985-01-01

A method of chemiluminescently determining a sulfide which is either hydrogen sulfide or methyl mercaptan by reacting the sulfide with chlorine dioxide at low pressure and under conditions which allow a longer reaction time in emission of a single photon for every two sulfide containing species, and thereafter, chemiluminescently detecting and determining the sulfide. The invention also relates not only to the detection method, but the novel chemical reaction and a specifically designed chemiluminescence detection cell for the reaction.

Polythiophene-block-poly(γ-benzyl L-glutamate): Synthesis and study of a new rod-rod block copolymer

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

Wu, Zong-Quan; Ono, Robert J.; Chen, Zheng

2011-01-01

Coupling of ethynyl terminated poly(3-hexylthiophene) with azide terminated poly(γ-benzyl L-glutamate) afforded the respective block copolymer in good yield and high purity; this material was found to self assemble into hierarchal structures in solution and in the solid state.

Potential anti-inflammatory phenolic glycosides from the medicinal plant Moringa oleifera fruits

USDA-ARS?s Scientific Manuscript database

Bioassay-guided isolation and purification of the ethyl acetate extract of Moringa oleifera fruits yielded three new phenolic glycosides; 4-[(2'-O-acetyl-a-L-rhamnosyloxy) benzyl]isothiocyanate (1), 4-[(3'-O-acetyl-a-L-rhamnosyloxy)benzyl]isothiocyanate (2), and S-methyl-N-{4-[(a-L-rhamnosyloxy)benz...

A MIXTURE OF THE "ANTIANDROGENS" LINURON AND BUTYL BENZYL PHTHALATE ALTERS SEXUAL DIFFERENTIATION OF THE MALE RAT IN A CUMULATIVE FASHION

EPA Science Inventory

Prenatal exposure to environmental chemicals that interfere with the androgen signaling pathway can cause permanent adverse effects on reproductive development in male rats. The objectives of this study were to 1) determine whether a documented antiandrogen butyl benzyl phthalate...

40 CFR 721.329 - Halogenated benzyl ester acrylate (generic).

Code of Federal Regulations, 2012 CFR

2012-07-01

... halogenated benzyl ester acrylate (PMN P-90-1527) is subject to reporting under this section for the... substance may cause internal organ effects (kidney and blood). The requirements of this section do not apply... processors of this substance as specified in § 721.125 (a), (b), (c), (d), (f), (g), (h), and (i). (2...

Effect of polyester blends in hydroentangled raw and bleached cotton nonwoven fabrics on the adsorption of alkyl-dimethyl-benzyl-ammonium chloride

USDA-ARS?s Scientific Manuscript database

The adsorption kinetics and isotherms of alkyl-dimethyl-benzyl-ammonium chloride (ADBAC), a cationic surfactant commonly employed as an antimicrobial agent, on hydroentangled nonwoven fabrics (applicable for wipes) including raw cotton, bleached cotton, and their blends with polyester (PES) were stu...

Development of a reliable extraction and quantification method for glucosinolates in Moringa oleifera.

PubMed

Förster, Nadja; Ulrichs, Christian; Schreiner, Monika; Müller, Carsten T; Mewis, Inga

2015-01-01

Glucosinolates are the characteristic secondary metabolites of plants in the order Brassicales. To date the common DIN extraction 'desulfo glucosinolates' method remains the common procedure for determination and quantification of glucosinolates. However, the desulfation step in the extraction of glucosinolates from Moringa oleifera leaves resulted in complete conversion and degradation of the naturally occurring glucosinolates in this plant. Therefore, a method for extraction of intact Moringa glucosinolates was developed and no conversion and degradation of the different rhamnopyranosyloxy-benzyl glucosinolates was found. Buffered eluents (0.1 M ammonium acetate) were necessary to stabilize 4-α-rhamnopyranosyloxy-benzyl glucosinolate (Rhamno-Benzyl-GS) and acetyl-4-α-rhamnopyranosyloxy-benzyl glucosinolate isomers (Ac-Isomers-GS) during HPLC analysis. Due to the instability of intact Moringa glucosinolates at room temperature and during the purification process of single glucosinolates, influences of different storage (room temperature, frozen, thawing and refreezing) and buffer conditions on glucosinolate conversion were analysed. Conversion and degradations processes were especially determined for the Ac-Isomers-GS III. Copyright © 2014 Elsevier Ltd. All rights reserved.

The Antimalarial Activities of Methylene Blue and the 1,4-Naphthoquinone 3-[4-(Trifluoromethyl)Benzyl]-Menadione Are Not Due to Inhibition of the Mitochondrial Electron Transport Chain

PubMed Central

Ehrhardt, Katharina; Ke, Hangjun; Vaidya, Akhil B.; Lanzer, Michael

2013-01-01

Methylene blue and a series of recently developed 1,4-naphthoquinones, including 3-[4-(substituted)benzyl]-menadiones, are potent antimalarial agents in vitro and in vivo. The activity of these structurally diverse compounds against the human malaria parasite Plasmodium falciparum might involve their peculiar redox properties. According to the current theory, redox-active methylene blue and 3-[4-(trifluoromethyl)benzyl]-menadione are “subversive substrates.” These agents are thought to shuttle electrons from reduced flavoproteins to acceptors such as hemoglobin-associated or free Fe(III)-protoporphyrin IX. The reduction of Fe(III)-protoporphyrin IX could subsequently prevent essential hemoglobin digestion and heme detoxification in the parasite. Alternatively, owing to their structures and redox properties, methylene blue and 1,4-naphthoquinones might also affect the mitochondrial electron transport chain. Here, we tested the latter hypothesis using an established system of transgenic P. falciparum cell lines and the antimalarial agents atovaquone and chloroquine as controls. In contrast to atovaquone, methylene blue and 3-[4-(trifluoromethyl)benzyl]-menadione do not inhibit the mitochondrial electron transport chain. A systematic comparison of the morphologies of drug-treated parasites furthermore suggests that the three drugs do not share a mechanism of action. Our findings support the idea that methylene blue and 3-[4-(trifluoromethyl)benzyl]-menadione exert their antimalarial activity as redox-active subversive substrates. PMID:23439633

Effect of yeast assimilable nitrogen on the synthesis of phenolic aroma compounds by Hanseniaspora vineae strains.

PubMed

Martin, Valentina; Boido, Eduardo; Giorello, Facundo; Mas, Albert; Dellacassa, Eduardo; Carrau, Francisco

2016-07-01

In several grape varieties, the dominating aryl alkyl alcohols found are the volatile group of phenylpropanoid-related compounds, such as glycosylated benzyl and 2-phenylethyl alcohol, which contribute to wine with floral and fruity aromas after being hydrolysed during fermentation. Saccharomyces cerevisiae is largely recognized as the main agent in grape must fermentation, but yeast strains belonging to other genera, including Hanseniaspora, are known to predominate during the first stages of alcoholic fermentation. Although non-Saccharomyces yeast strains have a well-recognized genetic diversity, understanding of their impact on wine flavour richness is still emerging. In this study, 11 Hansenisapora vineae strains were used to ferment a chemically defined simil-grape fermentation medium, resembling the nutrient composition of grape juice but devoid of grape-derived secondary metabolites. GC-MS analysis was performed to determine volatile compounds in the produced wines. Our results showed that benzyl alcohol, benzyl acetate and 2-phenylethyl acetate are significantly synthesized by H. vineae strains. Levels of these compounds found in fermentations with 11 H. vineae different strains were one or two orders of magnitude higher than those measured in fermentations with a known S. cerevisiae wine strain. The implications for winemaking in response to the negative correlation of benzyl alcohol, benzyl acetate and 2-phenylethyl acetate production with yeast assimilable nitrogen concentrations are discussed. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

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.

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

Postprocedural pain in shoulder arthrography: differences between using preservative-free normal saline and normal saline with benzyl alcohol as an intraarticular contrast diluent.

PubMed

Storey, Troy F; Gilbride, George; Clifford, Kelly

2014-11-01

The purpose of this study was to prospectively evaluate the effect of benzyl alcohol, a common preservative in normal saline, on postprocedural pain after intraarticular injection for direct shoulder MR arthrography. From April 2011 through January 2013, 138 patients underwent direct shoulder MR arthrography. Using the Wong-Baker Faces Pain Scale, patients were asked to report their shoulder pain level immediately before and immediately after the procedure and then were contacted by telephone 6, 24, and 48 hours after the procedure. Fourteen patients did not receive the prescribed amount of contrast agent for diagnostic reasons or did not complete follow-up. Sixty-two patients received an intraarticular solution including preservative-free normal saline (control group) and 62 patients received an intraarticular solution including normal saline with 0.9% benzyl alcohol as a contrast diluent (test group). Patients were randomized as to which intraarticular diluent they received. Fluoroscopic and MR images were reviewed for extracapsular contrast agent administration or extravasation, full-thickness rotator cuff tears, and adhesive capsulitis. The effect of preservative versus control on pain level was estimated with multiple regression, which included time after procedure as the covariate and accounted for repeated measures over patients. Pain scale scores were significantly (p = 0.0382) higher (0.79 units; 95% CI, 0.034-1.154) with benzyl alcohol preservative compared with control (saline). In both study arms, the pain scale scores decreased slightly after the procedure, increased by roughly 1 unit over baseline for the test group and 0.3 unit over baseline for the control group by 6 hours after the procedure, were 0.50 unit over baseline for the test group and 0.12 unit over baseline for the control group at 24 hours, then fell to be slightly greater than baseline at 48 hours with benzyl alcohol and slightly less than baseline without benzyl alcohol. These trends over time were highly significant (p < 0.0001). Shoulder arthrography is often associated with postprocedural discomfort that begins immediately after the procedure and resolves by 48 hours. There is significantly increased patient discomfort at 6 and 48 hours when using normal saline preserved with benzyl alcohol as a diluent compared with using normal saline without preservative as a diluent.

Environmentally Compliant Coating Remover Evaluation

DTIC Science & Technology

2012-08-30

22 9 Total of 491 products evaluated 7 Background • Many DoD depainting operations currently use environmentally compliant peroxide -assisted... benzyl alcohol strippers • These strippers have acceptable coating removal rates with minimal physical damage to metallic substrates • However, several...Coatings • Environmentally compliant benzyl alcohol product • Passed corrosion testing conducted by SMI in 2011 11 Laboratory Testing Scope

Effects of benzyl isothiocyanate on the reproduction of Meloidogyne incognita on Glycine max and Capsicum annuum

USDA-ARS?s Scientific Manuscript database

Reproduction of Meloidogyne incognita on Capsicum annuum or Glycine max was suppressed when infective juveniles (J2) were exposed to 0.03 millimolar benzyl isothiocyanate (BITC) for 2hr prior to inoculation of the host. Infectivity assessed by gall index was significantly reduced on both G. max (co...

Multicomponent Synthesis of a N-Protected Alpha-Amino Ester: Ethyl 2-((4-Methoxyphenyl)Amino)-3-Phenylpropanoate

ERIC Educational Resources Information Center

Le Gall, Erwan; Pignon, Antoine

2012-01-01

This laboratory experiment describes the preparation of a N-protected phenylalanine ethyl ester by a zinc-mediated Mannich-like multicomponent reaction between benzyl bromide, "p"-anisidine, and ethyl glyoxylate. The one-step reaction involves the in situ metallation of benzyl bromide into a benzylzinc reagent and its addition onto imine (Barbier…

Palladium-catalyzed, pyrrolidine-mediated arylmethylation of ketones and aldehydes with coumarinyl(methyl) acetates.

PubMed

Cattopadhyay, Kalicharan; Recio, Antonio; Tunge, Jon A

2012-09-14

We report the palladium-catalyzed, pyrrolidine-mediated α-benzylation of enamines generated from aldehydes and ketones. The method allows for direct coupling of medicinally relevant coumarin moieties with aldehydes and ketones in good yield under mild conditions. The reaction is believed to proceed via a Pd-π-benzyl complex generated from (coumarinyl)methyl acetates.

Mössbauer study of novel iron(II) complexes synthesized with Schiff bases

NASA Astrophysics Data System (ADS)

Várhelyi, Cs.; Lengyel, A.; Homonnay, Z.; Szalay, R.; Pokol, Gy.; Szilágyi, I.-M.; Huszthy, P.; Papp, J.; Goga, F.; Golban, L.-M.; Várhelyi, M.; Tomoaia-Cotisel, M.; Szőke, Á.; Kuzmann, E.

2017-11-01

Novel [Fe(4-benzyl-2-hydroxyphenyl-propylidene)2ethylene-diamine], and [Fe (2,4,6-trihydroxy-benzyl-4-metoxiphenyl-methylidene)2ethylene-diamine] complexes were synthesized by reacting FeII salt with the indicated Schiff-base ligands. The compounds were characterized by57Fe Mössbauer spectroscopy, FTIR, UV-VIS, TG-DTA-DTG, MS, AFM, XRD, cyclic voltammetry and biological activity measurements. 295 K and 78 K Mössbauer spectra revealed that iron is dominantly in high spin FeII state in both complexes while simultaneously a minor low spin FeII was also present in both complexes, furthermore a minor high spin FeIII was observed in [Fe(2,4,6-trihydroxy-benzyl-4-metoxiphenyl- methylidene) 2ethylene-diamine], too.

Spin-Center Shift-Enabled Direct Enantioselective α-Benzylation of Aldehydes with Alcohols.

PubMed

Nacsa, Eric D; MacMillan, David W C

2018-03-07

Nature routinely engages alcohols as leaving groups, as DNA biosynthesis relies on the removal of water from ribonucleoside diphosphates by a radical-mediated "spin-center shift" (SCS) mechanism. Alcohols, however, remain underused as alkylating agents in synthetic chemistry due to their low reactivity in two-electron pathways. We report herein an enantioselective α-benzylation of aldehydes using alcohols as alkylating agents based on the mechanistic principle of spin-center shift. This strategy harnesses the dual activation modes of photoredox and organocatalysis, engaging the alcohol by SCS and capturing the resulting benzylic radical with a catalytically generated enamine. Mechanistic studies provide evidence for SCS as a key elementary step, identify the origins of competing reactions, and enable improvements in chemoselectivity by rational photocatalyst design.

Synthesis and characterization of poly (benzyl trimethyl ammonium chloride) ionic polymer

NASA Astrophysics Data System (ADS)

Mathew, Manjusha Elizabeth; Ahmad, Ishak; Thomas, Sabu; Daik, Rusli; Kassim, Muhammad

2018-04-01

Poly vinyl benzyl chloride (PVBC) was synthesized by free radical polymerization of 4-vinyl benzyl chloride (VBC) using benzoyl peroxide initiator at 80°C. Amine functionalised polymer prepared by treatment of PVBC with trimethyl amine in different solvents such as water, ethanol, tetra hydro furan(THF) and dimethyl formamide(DMF). The polymers characterized structurally by nuclear magnetic resonance and infrared spectroscopic techniques. The thermal decomposition of the polymer is studied by Thermo Gravimetric Analysis(TGA) and found that the polymer has stability up to 230°C. The nitrogen content of the aminated polymer determined by elemental analysis. The nitrogen content obtained from tetra hydro furan and dimethyl formamide solvents are 20.1% and 19.9% respectively.

Molecular origin of the selectivity differences between palladium and gold-palladium in benzyl alcohol oxidation: Different oxygen adsorption properties

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

Savara, Aditya Ashi; Chan-Thaw, Carine E.; Sutton, Jonathan E.

The same mechanism and microkinetic model used for benzyl alcohol oxidation over Pd/C was shown to apply to benzyl alcohol oxidation over AuPd/C. Almost all of the selectivity differences could be explained by a decrease in oxygen adsorption on AuPd. After isolating oxygen adsorption as being the origin of the selectivity differences, density functional theory was used to investigate the oxygen adsorption properties of a pure Pd surface, a pure Au surface, and an alloyed AuPd surface. Finally, the calculations showed that Au–Pd alloying decreased the oxygen adsorption properties relative to pure Pd, which explained the selectivity differences, consistent withmore » the microkinetic modeling.« less

Testing odorants recovery from a novel metallized fluorinated ethylene propylene gas sampling bag.

PubMed

Zhu, Wenda; Koziel, Jacek A; Cai, Lingshuang; Wright, Donald; Kuhrt, Fred

2015-12-01

Industry-standard Tedlar bags for odor sample collection from confined animal feeding operations (CAFOs) have been challenged by the evidence of volatile organic compound (VOC) losses and background interferences. Novel impermeable aluminum foil with a thin layer of fluorinated ethylene propylene (FEP) film on the surface that is in contact with a gas sample was developed to address this challenge. In this research, Tedlar and metallized FEP bags were compared for (a) recoveries of four characteristic CAFO odorous VOCs (ethyl mercaptan, butyric acid, isovaleric acid and p-cresol) after 30 min and 24 hr sample storage time and for (b) chemical background interferences. All air sampling and analyses were performed with solid-phase microextraction (SPME) followed by gas chromatography-mass spectroscopy (GC-MS). Mean target gas sample recoveries from metallized FEP bags were 25.9% and 28.0% higher than those in Tedlar bags, for 30 min and 24 hr, respectively. Metallized FEP bags demonstrated the highest p-cresol recoveries after 30-min and 24-hr storage, 96.1±44.5% and 44.8±10.2%, respectively, among different types of sampling bags reported in previous studies. However, a higher variability was observed for p-cresol recovery with metallized FEP bags. A 0% recovery of ethyl mercaptan was observed with Tedlar bags after 24-hr storage, whereas an 85.7±7.4% recovery was achieved with metallized FEP bags. Recoveries of butyric and isovaleric acids were similar for both bag types. Two major impurities in Tedlar bags' background were identified as N,N-dimethylacetamide and phenol, while backgrounds of metallized FEP bags were significantly cleaner. Reusability of metallized FEP bags was tested. Caution is advised when using polymeric materials for storage of livestock-relevant odorous volatile organic compounds. The odorants loss with storage time confirmed that long-term storage in whole-air form is ill advised. A focused short-term odor sample containment should be biased toward the most inert material available relative to the highest impact target odorant. Metallized FEP was identified as such a material to p-cresol as the highest impact odorant from confined animal feeding operations. Metallized FEP bags have much cleaner background than commercial Tedlar bags do. Significantly higher recoveries of methyl mercaptan and p-cresol were also observed with metallized FEP bags.

A new class of sulfoxide surfactants derived from Tris. Synthesis and preliminary assessments of their properties.

PubMed

Barthélémy, P; Maurizis, J C; Lacombe, J M; Pucci, B

1998-06-16

A new class of non-ionic amphiphilic molecules suitable for biological purposes, especially extraction of membrane proteins, is reported. Such surfactants were prepared in two steps: addition of alkyl or fluoroalkyl mercaptan on Tris(hydroxymethyl)acrylamidomethane (THAM) derivatives, followed by the oxydation of sulfide group in sulfoxide moiety in order to provide water solubility to the molecule. The detergent efficiency of these new surfactants were assayed on rat liver cells.

Sulfide chemiluminescence detection

DOEpatents

Spurlin, S.R.; Yeung, E.S.

1985-11-26

A method is described for chemiluminescently determining a sulfide which is either hydrogen sulfide or methyl mercaptan by reacting the sulfide with chlorine dioxide at low pressure and under conditions which allow a longer reaction time in emission of a single photon for every two sulfide containing species, and thereafter, chemiluminescently detecting and determining the sulfide. The invention also relates not only to the detection method, but the novel chemical reaction and a specifically designed chemiluminescence detection cell for the reaction. 4 figs.

Apparatus for use in sulfide chemiluminescence detection

DOEpatents

Spurlin, Stanford R.; Yeung, Edward S.

1987-01-01

A method of chemiluminescently determining a sulfide which is either hydrogen sulfide or methyl mercaptan by reacting the sulfide with chlorine dioxide at low pressure and under conditions which allow a longer reaction time in emission of a single photon for every two sulfide containing species, and thereafter, chemiluminescently detecting and determining the sulfide. The invention also relates not only to the detection method, but the novel chemical reaction and a specifically designed chemiluminescence detection cell for the reaction.

Two molecular wheels 12-MC-6 complexes: Synthesis, structure and magnetic property of [Co(μ{sub 2}-SEt){sub 2}]{sub 6} and [Fe(μ{sub 2}-SEt){sub 2}]{sub 6}

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

Wang, Jing; Jian, Fangfang, E-mail: ffj2003@163169.net; Huang, Baoxin

2013-08-15

The syntheses and structures of two ethyl mercaptan molecular wheels complexes, [M(μ{sub 2}-SCH{sub 2}CH{sub 3}){sub 2}]{sub 6} (M=Fe, Co), have been reported. Each metal atom is surrounded by four S atoms of the μ{sub 2}-SCH{sub 2}CH{sub 3} ligands in a distorted square plane fashion. The edge-sharing S{sub 4} square planes connect with each other to form a ring. Six metal atoms are located at the vertices of an almost hexagon, with M···M separations in the range of 2.903(1)∼2.936(2) Å for Fe and 2.889(2)∼2.962(2) Å for Co. The diameter of the ring, defined as the average distance between two opposing metalmore » atoms, is 5.850(1) Å for Fe and 5.780(1) Å for Co, respectively. The magnetic property behaves of cobalt(II) cluster complex is studied. Highlights: • Two new ethyl mercaptan cyclic hexanuclear complexes were reported. • The crystal structures shown center formation of M{sub 6}S{sub 12} molecular wheels. • The Co{sub 6} ring cluster complex represents as weak ferromagnet.« less

Inhibitory Effect of Enterococcus faecium WB2000 on Volatile Sulfur Compound Production by Porphyromonas gingivalis

PubMed Central

Higuchi, Takuya; Nakajima, Masato; Fujimoto, Akie; Hanioka, Takashi; Hirofuji, Takao

2016-01-01

Volatile sulfur compounds (VSCs) produced by oral anaerobes are the major compounds responsible for oral malodor. Enterococcus faecium WB2000 is recognized as an antiplaque probiotic bacterium. In this study, the effect of E. faecium WB2000 on VSC production by Porphyromonas gingivalis was evaluated, and the mechanism of inhibition of oral malodor was investigated. P. gingivalis ATCC 33277 was cultured in the presence of four lactic acid bacteria, including E. faecium WB2000. Subsequently, P. gingivalis ATCC 33277, W50, W83, and two clinical isolates were cultured in the presence or absence of E. faecium WB2000, and the emission of VSCs from spent culture medium was measured by gas chromatography. The number of P. gingivalis ATCC 33277 in mixed culture with E. faecium WB2000 decreased at 6 h, and the rate of decrease was higher than that in mixed cultures with the other lactic acid bacteria. The numbers of five P. gingivalis strains decreased at similar rates in mixed culture with E. faecium WB2000. The concentration of methyl mercaptan was lower in spent culture medium from P. gingivalis and E. faecium WB2000 cultures compared with that from P. gingivalis alone. Therefore, E. faecium WB2000 may reduce oral malodor by inhibiting the growth of P. gingivalis and neutralizing methyl mercaptan. PMID:27799940

Omeprazole, a specific inhibitor of gastric (H/sup +/-K/sup +/)-ATPase, is a H/sup +/-activated oxidizing agent of sulfhydryl groups

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

Im, W.B.; Sih, J.C.; Blakeman, D.P.

1985-04-25

Omeprazole (5-methoxy-2-(((4-methoxy-3,5- dimethylpyridinyl)methyl)sulfinyl)-1H-benzimidazole) appeared to inhibit gastric (H/sup +/-K/sup +/)-ATPase by oxidizing its essential sulfhydryl groups, since the gastric ATPase inactivated by the drug in vivo or in vitro recovered its K+-dependent ATP hydrolyzing activity upon incubation with mercaptoethanol. Biological reducing agents like cysteine or glutathione, however, were unable to reverse the inhibitory effect of omeprazole. Moreover, acidic environments enhanced the potency of omeprazole. The chemical reactivity of omeprazole with mercaptans is also consistent with the biological action of omeprazole. The N-sulfenylated compound reacted at neutral pH with another stoichiometric amount of ethyl mercaptan to produce omeprazole sulfide quantitatively. Themore » gastric polypeptides of 100 kilodaltons representing (H/sup +/-K/sup +/)-ATPase in the rat gastric mucosa or isolated hog gastric membranes were covalently labeled with (/sup 14/C)omeprazole. The radioactive label bound to the ATPase, however, could not be displaced by mercaptoethanol under the identical conditions where the ATPase activity was fully restored. These observations suggest that the essential sulfhydryl groups which reacted with omeprazole did not form a stable covalent bond with the drug, but rather that they further reacted with adjacent sulfhydryl groups to form disulfides which could be reduced by mercaptoethanol.« less

Raman spectroscopy, electronic microscopy and SPME-GC-MS to elucidate the mode of action of a new antimicrobial food packaging material.

PubMed

Clemente, Isabel; Aznar, Margarita; Salafranca, Jesús; Nerín, Cristina

2017-02-01

One critical challenge when developing a new antimicrobial packaging material is to demonstrate the mode of action of the antimicrobials incorporated into the packaging. For this task, several analytical techniques as well as microbiology are required. In this work, the antimicrobial properties of benzyl isothiocyanate, allyl isothiocyanate and essential oils of cinnamon and oregano against several moulds and bacteria have been evaluated. Benzyl isothiocyanate showed the highest antimicrobial activity and it was selected for developing the new active packaging material. Scanning electron microscopy and Raman spectroscopy were successfully used to demonstrate the mode of action of benzyl isothiocyanate on Escherichia coli. Bacteria exhibited external modifications such as oval shape and the presence of septum surface, but they did not show any disruption or membrane damage. To provide data on the in vitro action of benzyl isothiocyanate and the presence of inhibition halos, the transfer mechanism to the cells was assessed using solid-phase microextraction-gas chromatography-mass spectrometry. Based on the transfer system, action mechanism and its stronger antimicrobial activity, benzyl isothiocyanate was incorporated to two kinds of antimicrobial labels. The labels were stable and active for 140 days against two mould producers of ochratoxin A; Penicillium verrucosum is more sensitive than Aspergillus ochraceus. Details about the analytical techniques and the results obtained are shown and discussed. Graphical Abstract Antimicrobial evaluation of pure compounds, incorporation in the packaging and study for mode of action on S. coli by Raman, SEM and SPME-GC-MS.

The Role of the Plant Hormone Benzyl Adenine to Promote Growth for the Diatom Thalassiosira pseudonana

NASA Astrophysics Data System (ADS)

Gutierrez Franco, D.; Vernet, M.; Walters, R. J.; Tan, M.

2016-02-01

This study was inspired by the establishment of autoinduction in the model diatom Thalassiosira pseudonana, and the identification of the cytokinin plant hormone benzyl adenine (BA) as a potential autoinducer in this species via comparative genome studies. The effects of a wide range (0.0017518 mg/L-500 mg/L) of concentrations of benzyl adenine on the growth dynamics of T. pseudonana have been explored. The results suggest that a concentration of 5 mg BA/L has the highest positive effect on the growth rate of T. pseudonana batch cultures, compared to the other concentrations tested. Furthermore, concentrations of >100 mg BA/L were lethal. No marked effects on the lag phase length were observed. However, it is possible that some trade-offs between growth rate and lag phase length exist as a result of benzyl adenine. For instance, the BA concentration that exhibited the highest growth rate (5mg BA/L; µ=1.06 d-1) had a negative effect on the lag phase length (6 days), as compared to our control (lag phase length = 5 d; µ=0.81 d-1). On the other hand, at 10 mg BA/L, a slightly smaller growth rate of 1.01 d-1 was observed, with a shorter lag phase length of 4 days, suggesting that benzyl adenine may not have a positive effect on all growth parameters at once. These results provide insight into the physiological and biochemical mechanisms of cell-to-cell communication employed by diatoms, and supports the hypothesis that hormones may play an important role in bloom development.

Selective oxidation of benzyl alcohols to benzoic acid catalyzed by eco-friendly cobalt thioporphyrazine catalyst supported on silica-coated magnetic nanospheres.

PubMed

Li, Huan; Cao, Lan; Yang, Changjun; Zhang, Zhehui; Zhang, Bingguang; Deng, Kejian

2017-10-01

A novel magnetically recoverable thioporphyrazine catalyst (CoPz(S-Bu) 8 /SiO 2 @Fe 3 O 4 ) was prepared by immobilization of the cobalt octkis(butylthio) porphyrazine complex (CoPz(S-Bu) 8 ) on silica-coated magnetic nanospheres (SiO 2 @Fe 3 O 4 ). The composite CoPz(S-Bu) 8 /SiO 2 @Fe 3 O 4 appeared to be an active catalyst in the oxidation of benzyl alcohol in aqueous solution using hydrogen peroxide (H 2 O 2 ) as oxidant under Xe-lamp irradiation, with 36.4% conversion of benzyl alcohol, about 99% selectivity for benzoic acid and turnover number (TON) of 61.7 at ambient temperature. The biomimetic catalyst CoPz(S-Bu) 8 was supported on the magnetic carrier SiO 2 @Fe 3 O 4 so as to suspend it in aqueous solution to react with substrates, utilizing its lipophilicity. Meanwhile the CoPz(S-Bu) 8 can use its unique advantages to control the selectivity of photocatalytic oxidation without the substrate being subjected to deep oxidation. The influence of various reaction parameters on the conversion rate of benzyl alcohol and selectivity of benzoic acid was investigated in detail. Moreover, photocatalytic oxidation of substituted benzyl alcohols was obtained with high conversion and excellent selectivity, specifically conversion close to 70%, selectivity close to 100% and TON of 113.6 for para-position electron-donating groups. The selectivity and eco-friendliness of the biomimetic photocatalyst give it great potential for practical applications. Copyright © 2017. Published by Elsevier B.V.

Novel Side-Chain Liquid Cyrstalline Polymers

DTIC Science & Technology

1989-01-01

Synthesis and Characterization of Liquid Crystalline Polyacrylates and Poly- methacrylates Containing Benzyl Ether and Diphenyl Ethane Based Mesogens J...Crystalline Polymethacrylates and Polyacrylates of trans 2-[4-(11- hydroxyundecanyloxy)-3,5-dimethylphenylI-4-(4-methoxyphenyl)-l,3-dioxane Makromol. Chem., 189...and Characterization of Liquid Crystalline Polyacrylates and Poly- met acrylates Containing Benzyl Ether and Diphenyl Ethane Based Mesogens J. Polym

The Synthesis of "N"-Benzyl-2-Azanorbornene via Aqueous Hetero Diels-Alder Reaction: An Undergraduate Project in Organic Synthesis and Structural Analysis

ERIC Educational Resources Information Center

Sauvage, Xavier; Delaude, Lionel

2008-01-01

The synthesis of "N"-benzyl-2-azanorbornene via aqueous hetero Diels-Alder reaction of cyclopentadiene and benzyliminium chloride formed in situ from benzylamine hydrochloride and formaldehyde is described. Characterization of the product was achieved by IR and NMR spectroscopies. The spectral data acquired are thoroughly discussed. Numerous…

Palladium-catalyzed, pyrrolidine-mediated arylmethylation of ketones and aldehydes with coumarinyl(methyl) acetates†

PubMed Central

Cattopadhyay, Kalicharan; Recio, Antonio; Tunge, Jon A.

2012-01-01

We report the palladium-catalyzed, pyrrolidine-mediated α-benzylation of enamines generated from aldehydes and ketones. The method allows for direct coupling of medicinally relevant coumarin moieties with aldehydes and ketones in good yield under mild conditions. The reaction is believed to proceed via a Pd-π-benzyl complex generated from (coumarinyl)methyl acetates. PMID:22832549

Caterpillar-induced plant volatiles attract conspecific adults in nature

PubMed Central

El-Sayed, Ashraf M.; Knight, Alan L.; Byers, John A.; Judd, Gary J. R.; Suckling, David M.

2016-01-01

Plants release volatiles in response to caterpillar feeding that attract natural enemies of the herbivores, a tri-trophic interaction which has been considered an indirect plant defence against herbivores. The caterpillar-induced plant volatiles have been reported to repel or attract conspecific adult herbivores. To date however, no volatile signals that either repel or attract conspecific adults under field conditions have been chemically identified. Apple seedlings uniquely released seven compounds including acetic acid, acetic anhydride, benzyl alcohol, benzyl nitrile, indole, 2-phenylethanol, and (E)-nerolidol only when infested by larvae of the light brown apple moth, Epiphyas postvittana. In field tests in New Zealand, a blend of two of these, benzyl nitrile and acetic acid, attracted a large number of conspecific male and female adult moths. In North America, male and female adults of the tortricid, oblique-banded leafroller, Choristoneura rosaceana, were most attracted to a blend of 2-phenylethanol and acetic acid. Both sexes of the eye-spotted bud moth, Spilonota ocellana, were highly attracted to a blend of benzyl nitrile and acetic acid. This study provides the first identification of caterpillar-induced plant volatiles that attract conspecific adult herbivores under natural conditions, challenging the expectation of herbivore avoidance of these induced volatiles. PMID:27892474

Structure-to-property relationships in addition cured polymers. 4: Correlations between thermo-oxidative weight losses of norbornenyl cured polyimide resins and their composites

NASA Technical Reports Server (NTRS)

Alston, William B.

1992-01-01

Relationships are identified between the thermo-oxidative stability (TOS) at 316 C of a wide variety of PMR (polymerization of monomeric reactants) addition cured polyimide resins and their corresponding graphite fiber composites. Weight loss results at 316 C confirmed the expected relationship of increasing aliphatic endcap content with decreasing TOS. Moreover, the resin TOS study also showed an unexpected linear correlation of decreasing weight loss to increasing ratio of benzylic diamine to aliphatic endcap in the range of the stoichiometries studied. Only after long term 316 C aging does the dianhydride used with the benzylic diamines become an additional factor in influencing the amount of PMR resin and composite weight losses. Also, the benzylic systems consistently showed much lower resin and composite weight losses at 316 C than the corresponding nonbenzylic norbornenyl resins and composites, except when the nonbenzylic diamine monomer does not contain a connecting group. Instead, this diamine resulted in a 316 C resin and composite weight loss that was only competitive with benzylic type diamines. Results show excellent correlation between TOS of all graphite fiber PMR composites and resins.

Liquid-liquid extraction of ethanol from aqueous solutions with amyl acetate, benzyl alcohol, and methyl isobutyl ketone at 298. 15. Kappa

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

Solimo, H.N.; Martinez, H.E.; Riggio, R.

1989-04-01

Experimental mutual solubility and tie-line data were determined for three ternary liquid-liquid systems containing water, ethanol, and amyl acetate, benzyl alcohol, and methyl isobutyl ketone at 298.15{Kappa} in order to obtain their complete phase diagrams and to determine which is the most suitable solvent for extraction of ethanol from aqueous solutions. Tie lines were determined correlating the density of the binodal curve as a function of composition and the plait points using the Othmer and Tobias method. The experimental data were also correlated with the UNIFAC group contribution method. A qualitative agreement was obtained. Experimental results show that amyl acetatemore » is a better solvent than methyl isobutyl ketone and benzyl alcohol.« 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.

Spectroscopic and structural studies of a new para-iodo-N-benzyl amide of salinomycin

NASA Astrophysics Data System (ADS)

Antoszczak, Michał; Janczak, Jan; Rutkowski, Jacek; Brzezinski, Bogumił; Huczyński, Adam

2017-11-01

A new para-iodo-N-benzyl amide of salinomycin was synthesized and characterized by NMR, FT-IR, DFT, single crystal X-ray diffraction and theoretical methods. The results obtained for the crystal, in solution and in gas phase provided evidence of pseudo-cyclic structure of this compound stabilized by intramolecular hydrogen bonds. It was shown that the compound studied forms stable 1:1 complexes with monovalent (Li+, Na+, K+, Rb+ and Cs+) and divalent (Mg2+, Ca2+, Sr2+ and Ba2+) cations demonstrating that the chemical modification of salinomycin carboxyl group considerably changes the ionophoretic properties of this antibiotic. For the first time, the ESI MS fragmentations of the complex of para-iodo-N-benzyl amide of salinomycin with Na+ are also discussed in details.

First example of a heterobimetallic 'Pd-Sn' catalyst for direct activation of alcohol: efficient allylation, benzylation and propargylation of arenes, heteroarenes, active methylenes and allyl-Si nucleophiles.

PubMed

Das, Debjit; Pratihar, Sanjay; Roy, Ujjal Kanti; Mal, Dipakranjan; Roy, Sujit

2012-06-21

Arenes, heteroarenes, 1,3-dicarbonyls and organosilicon nucleophiles undergo highly efficient alkylation with allylic, propargylic and benzylic alcohols in the presence of a new 'Pd-Sn' bimetallic catalyst in nitromethane; water being the sole byproduct. The plausible mechanism of alkylation and the intermediacy of ether has been enumerated.

A general palladium-catalyzed carbonylative synthesis of chromenones from salicylic aldehydes and benzyl chlorides.

PubMed

Wu, Xiao-Feng; Wu, Lipeng; Jackstell, Ralf; Neumann, Helfried; Beller, Matthias

2013-09-09

Cute CO! An interesting and straightforward procedure for the carbonylative synthesis of chromenones from readily available salicylic aldehydes and benzyl chlorides has been developed (see scheme; DPPP = 1,3-bis(diphenylphosphino)propane). In the presence of a palladium catalyst, various coumarins were produced in good to excellent yields. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Acute Toxicity of a Number of Chemicals of Interest to the Air Force

DTIC Science & Technology

1979-03-01

Acid Azelaic Acid Dimer Acid N-Benzyl-3, 7-Dioctyl Phenothiazine Phenothiazine Dioctyl Phenothiazine Sebacic Acid ...liquid) 1,4-dihydroxyanthraquinone (solid) Sulfurized 9-octadecenoic acid (liquid) Azelaic acid (solid) Dimer acid (liquid) N-benzyl-3,7-dicotyl...dihydroxyanthra- Rat >5000 5000(0) Below Toxic quinone Sulfurized 9-octa- Rat >5000 5000(0) Below Toxic decenoic acid Azelaic acid Rat >5000

General synthesis of 2,1-benzisoxazoles (anthranils) from nitroarenes and benzylic C-H acids in aprotic media promoted by combination of strong bases and silylating agents.

PubMed

Wiȩcław, Michał; Bobin, Mariusz; Kwast, Andrzej; Bujok, Robert; Wróbel, Zbigniew; Wojciechowski, Krzysztof

2015-11-01

Carbanions of phenylacetonitriles, benzyl sulfones, and dialkyl benzylphosphonates add nitroarenes at the ortho-position to the nitro group to form [Formula: see text]-adducts that, upon treatment with trialkylchlorosilane and additional base (t-BuOK or DBU), transform into 3-aryl-2,1-benzisoxazoles in moderate-to-good yields.

Synthesis and Degradation of Schiff Bases Containing Heterocyclic Pharmacophore

PubMed Central

Ledeţi, Ionuţ; Alexa, Anda; Bercean, Vasile; Vlase, Gabriela; Vlase, Titus; Şuta, Lenuţa-Maria; Fuliaş, Adriana

2015-01-01

This paper reports on the synthesis and characterization of two Schiff bases bearing 1,2,4-triazolic moieties, namely 4H-4-(2-hydroxy-benzylidene-amino)-5-benzyl-3-mercapto-1,2,4-triazole and 4H-4-(4-nitro-benzylidene-amino)-5-benzyl-3-mercapto-1,2,4-triazole using thin layer chromatography, melting interval, elemental analysis, spectroscopy and thermal stability studies. PMID:25590299

Headspace gas chromatography based methodology for the analysis of aromatic substituted quaternary ammonium salts.

PubMed

van Boxtel, Niels; Wolfs, Kris; Palacín, Marta Guillén; Van Schepdael, Ann; Adams, Erwin

2016-12-09

The analysis of quaternary ammonium salts (QAS) using GC is often performed by "in injector" pyrolysis to create volatile degradation products for quantification purposes. Besides the risk of severe system contamination, the application of this approach on aqueous samples is problematic. In this work, the sample is treated in a vial with 2,2-dimethoxypropane (DMP) under acidic catalysis. In addition to the removal of water and sample enrichment, the QAS are decomposed. As HS transfers only volatile compounds to the GC system, contamination is avoided. It was found that depending on the presence of benzyl, phenyl or methyl groups on the quaternary nitrogen; benzyl chloride, N,N-dimethylaniline or chloromethane are formed respectively in the sealed vial. All these can be used as an analytical target. A calibration curve for benzyl chloride could be derived from the pure compound. Chloromethane was generated from pure benzyldimethyldecylammonium chloride (BEDIDE), a pure QAS with benzyl and methyl groups, to construct a secondary calibration curve using a back analysis approach. It has been proven that by quantifying the formed analytical targets, the mass balance for the QAS under investigation was close to 100%. The presented procedure allows the quantification of any aromatic substituted QAS without the need for a matching reference, which is a major advantage over existing CE and LC methods The proposed methodology was validated for mouth sprays containing benzethonium chloride (BZTCl) or benzoxonium chloride (BZOCl) and for denatonium benzoate (DB) in ethylene glycol (EG) based cooling liquids. Results showed that the approach provided excellent linearity (R 2 ≥0.999) and limits of detection around 0.01μg/vial for benzyl chloride. It was found that the reaction product of DMP and glycerol which was also present in the mouthspray and some cooling liquids, caused chromatographic interference with benzyl chloride. Treating those samples in the vial with N,O-bis(trimethylsilyl)trifluoroacetamide (BSTFA) after the enrichment step removes the interference and leaves a possible pathway for the simultaneous determination of glycerol in those samples. Copyright © 2016 Elsevier B.V. All rights reserved.

Apparatus for use in sulfide chemiluminescence detection

DOEpatents

Spurlin, S.R.; Yeung, E.S.

1987-01-06

A method is described for chemiluminescently determining a sulfide which is either hydrogen sulfide or methyl mercaptan by reacting the sulfide with chlorine dioxide at low pressure and under conditions which allow a longer reaction time in emission of a single photon for every two sulfide containing species, and thereafter, chemiluminescently detecting and determining the sulfide. The invention also relates not only to the detection method, but the novel chemical reaction and a specifically designed chemiluminescence detection cell for the reaction. 4 figs.

Method of generating chemiluminescent light

DOEpatents

Spurlin, S.R.; Yeung, E.S.

1986-03-11

A method of chemiluminescently determining a sulfide which is either hydrogen sulfide or methyl mercaptan by reacting the sulfide with chlorine dioxide at low pressure and under conditions which allow a longer reaction time in emission of a single photon for every two sulfide containing species, and thereafter, chemiluminescently detecting and determining the sulfide. The invention also relates not only to the detection method, but the novel chemical reaction that generates chemiluminescent light and a specifically designed chemiluminescence detection cell for the reaction. 4 figs.

Method of generating chemiluminescent light

DOEpatents

Spurlin, Stanford R.; Yeung, Edward S.

1986-01-01

A method of chemiluminescently determining a sulfide which is either hydrogen sulfide or methyl mercaptan by reacting the sulfide with chlorine dioxide at low pressure and under conditions which allow a longer reaction time in emission of a single photon for every two sulfide containing species, and thereafter, chemiluminescently detecting and determining the sulfide. The invention also relates not only to the detection method, but the novel chemical reaction that generates chemiluminescent light and a specifically designed chemiluminescence detection cell for the reaction.

High frequency transformers and high Q factor inductors formed using epoxy-based magnetic polymer materials

DOEpatents

Sanchez, Robert O.; Gunewardena, Shelton; Masi, James V.

2007-11-27

An electrical component in the form of an inductor or transformer is disclosed which includes one or more coils and a magnetic polymer material located near the coils or supporting the coils to provide an electromagnetic interaction therewith. The magnetic polymer material is preferably a cured magnetic epoxy which includes a mercaptan derivative having a ferromagnetic atom chemically bonded therein. The ferromagnetic atom can be either a transition metal or rare-earth atom.

High frequency transformers and high Q factor inductors formed using epoxy-based magnetic polymer materials

DOEpatents

Sanchez, Robert O.; Gunewardena, Shelton; Masi, James V.

2005-03-29

An electrical component in the form of an inductor or transformer is disclosed which includes one or more coils and a magnetic polymer material located near the coils or supporting the coils to provide an electromagnetic interaction therewith. The magnetic polymer material is preferably a cured magnetic epoxy which includes a mercaptan derivative having a ferromagnetic atom chemically bonded therein. The ferromagnetic atom can be either a transition metal or rare-earth atom.

Project Summary: Increased Fuel Affordability Through Deployable Refining Technology (Briefing Charts)

DTIC Science & Technology

2016-05-01

distribution is unlimited. PA Clearance #16274 2 Overall Process DISTRIBUTION A. Approved for public release; distribution unlimited. 3 Sulfur in Fuels...Mercaptans (Thiols) The presence of sulfur in fuels leads to many detrimental effects: • Coking on rocket engine injector plates • Deposit formation in... Sulfur Compounds by GC-SCD ( Sulfur Speciation) Concentration (ppm) C2 Thiophenes 0.3 C3-C4 Thiophenes 1.4 C5 Thiophenes 3.7 C6 Thiophenes 3.5 C7

Effect of Refining Variables on the Properties and Composition of JP-5.

DTIC Science & Technology

1980-11-01

specific fuel system components. This is believed to be caused by the removal of naturally occurring impurities such as organic acids and some polynuclear...PADs 3 and 5 would require additional downstream processing to remove aromatics and/or mercaptans in order to make acceptable grade JP-5. The MTY of JP...made.) Now that the mandatory allocation of kerosine jet fuel has been removed , it will be important to see if the refinery mix that will provide JP

The thermal decomposition of the benzyl radical in a heated micro-reactor. II. Pyrolysis of the tropyl radical

NASA Astrophysics Data System (ADS)

Buckingham, Grant T.; Porterfield, Jessica P.; Kostko, Oleg; Troy, Tyler P.; Ahmed, Musahid; Robichaud, David J.; Nimlos, Mark R.; Daily, John W.; Ellison, G. Barney

2016-07-01

Cycloheptatrienyl (tropyl) radical, C7H7, was cleanly produced in the gas-phase, entrained in He or Ne carrier gas, and subjected to a set of flash-pyrolysis micro-reactors. The pyrolysis products resulting from C7H7 were detected and identified by vacuum ultraviolet photoionization mass spectrometry. Complementary product identification was provided by infrared absorption spectroscopy. Pyrolysis pressures in the micro-reactor were roughly 200 Torr and residence times were approximately 100 μs. Thermal cracking of tropyl radical begins at 1100 K and the products from pyrolysis of C7H7 are only acetylene and cyclopentadienyl radicals. Tropyl radicals do not isomerize to benzyl radicals at reactor temperatures up to 1600 K. Heating samples of either cycloheptatriene or norbornadiene never produced tropyl (C7H7) radicals but rather only benzyl (C6H5CH2). The thermal decomposition of benzyl radicals has been reconsidered without participation of tropyl radicals. There are at least three distinct pathways for pyrolysis of benzyl radical: the Benson fragmentation, the methyl-phenyl radical, and the bridgehead norbornadienyl radical. These three pathways account for the majority of the products detected following pyrolysis of all of the isotopomers: C6H5CH2, C6H5CD2, C6D5CH2, and C6H513CH2. Analysis of the temperature dependence for the pyrolysis of the isotopic species (C6H5CD2, C6D5CH2, and C6H513CH2) suggests the Benson fragmentation and the norbornadienyl pathways open at reactor temperatures of 1300 K while the methyl-phenyl radical channel becomes active at slightly higher temperatures (1500 K).

The thermal decomposition of the benzyl radical in a heated micro-reactor. II. Pyrolysis of the tropyl radical

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

Buckingham, Grant T.; Porterfield, Jessica P.; Kostko, Oleg

2016-07-05

Cycloheptatrienyl (tropyl) radical, C7H7, was cleanly produced in the gas-phase, entrained in He or Ne carrier gas, and subjected to a set of flash-pyrolysis micro-reactors. The pyrolysis products resulting from C7H7 were detected and identified by vacuum ultraviolet photoionization mass spectrometry. Complementary product identification was provided by infrared absorption spectroscopy. Pyrolysis pressures in the micro-reactor were roughly 200 Torr and residence times were approximately 100 us. Thermal cracking of tropyl radical begins at 1100 K and the products from pyrolysis of C7H7 are only acetylene and cyclopentadienyl radicals. Tropyl radicals do not isomerize to benzyl radicals at reactor temperatures upmore » to 1600 K. Heating samples of either cycloheptatriene or norbornadiene never produced tropyl (C7H7) radicals but rather only benzyl (C6H5CH2). The thermal decomposition of benzyl radicals has been reconsidered without participation of tropyl radicals. There are at least three distinct pathways for pyrolysis of benzyl radical: the Benson fragmentation, the methyl-phenyl radical, and the bridgehead norbornadienyl radical. These three pathways account for the majority of the products detected following pyrolysis of all of the isotopomers: C6H5CH2, C6H5CD2, C6D5CH2, and C6H5 13CH2. Analysis of the temperature dependence for the pyrolysis of the isotopic species (C6H5CD2, C6D5CH2, and C6H5 13CH2) suggests the Benson fragmentation and the norbornadienyl pathways open at reactor temperatures of 1300 K while the methyl-phenyl radical channel becomes active at slightly higher temperatures (1500 K).« less

Monitoring the emission of volatile organic compounds from flowers of Jasminum sambac using solid-phase micro-extraction fibers and gas chromatography with mass spectrometry detection.

PubMed

Pragadheesh, Vppalayam Shanmugam; Yadav, Anju; Chanotiya, Chandan Singh; Rout, Prasanta Kumar; Uniyal, Girish Chandra

2011-09-01

Solid-phase micro-extraction (SPME) was studied as a solvent free alternative method for the extraction and characterization of volatile compounds in intact and plucked flowers of Jasminum sambac at different day time intervals using gas chromatography (GC-FID) and gas chromatography-quadrupole mass spectrometry. The analytes identified included alcohols, esters, phenolic compounds, and terpenoids. The main constituents identified in the flower aroma using different fibers were cis-3-hexenyl acetate, (E)-beta-ocimene, linalool, benzyl acetate, and (E,E)-alpha-farnesene. The benzyl acetate proportion decreased from morning to afternoon and then increased in evening collections. PDMS fiber showed a high proportion of (E,E)-alpha-farnesene in jasmine floral aroma. Among other constituents identified, cis-3-hexenyl acetate, linalool, and benzyl acetate were major aroma contributors in plucked and living flowers extracts using PDMS/DVB, Carboxen/PDMS, and DVB/Carboxen/PDMS fibers. PDMS/DVB recorded the highest emission for benzyl acetate while the (E)-beta-ocimene proportion was highest in DVB/Carboxen/PDMS when compared with the rest. The highest linalool content, with increasing proportion from morning to noon, was found using mixed coating fibers. Almost negligible volatile adsorption was recorded for the polyacrylate fiber for intact flower aroma, whereas it was most effective for benzyl acetate, followed by indole under plucked conditions. Moreover, the highest amounts extracted, evaluated from the sum of peak areas, were achieved using Carboxen/PDMS, and DVB/Carboxen/PDMS. Introduction of a rapid, and solvent free SPME method for the analysis of multicomponent volatiles can be successfully employed to monitor the extraction and characterization of flower aroma constituents.

Proline-Based Carbamates as Cholinesterase Inhibitors.

PubMed

Pizova, Hana; Havelkova, Marketa; Stepankova, Sarka; Bak, Andrzej; Kauerova, Tereza; Kozik, Violetta; Oravec, Michal; Imramovsky, Ales; Kollar, Peter; Bobal, Pavel; Jampilek, Josef

2017-11-14

Series of twenty-five benzyl (2S)-2-(arylcarbamoyl)pyrrolidine-1-carboxylates was prepared and completely characterized. All the compounds were tested for their in vitro ability to inhibit acetylcholinesterase (AChE) and butyrylcholinesterase (BChE), and the selectivity of compounds to individual cholinesterases was determined. Screening of the cytotoxicity of all the compounds was performed using a human monocytic leukaemia THP-1 cell line, and the compounds demonstrated insignificant toxicity. All the compounds showed rather moderate inhibitory effect against AChE; benzyl (2 S )-2-[(2-chlorophenyl)carbamoyl]pyrrolidine-1-carboxylate (IC 50 = 46.35 μM) was the most potent agent. On the other hand, benzyl (2 S )-2-[(4-bromophenyl)-] and benzyl (2 S )-2-[(2-bromophenyl)carbamoyl]pyrrolidine-1-carboxylates expressed anti-BChE activity (IC 50 = 28.21 and 27.38 μM, respectively) comparable with that of rivastigmine. The ortho -brominated compound as well as benzyl (2 S )-2-[(2-hydroxyphenyl)carbamoyl]pyrrolidine-1-carboxylate demonstrated greater selectivity to BChE. The in silico characterization of the structure-inhibitory potency for the set of proline-based carbamates considering electronic, steric and lipophilic properties was provided using comparative molecular surface analysis (CoMSA) and principal component analysis (PCA). Moreover, the systematic space inspection with splitting data into the training/test subset was performed to monitor the statistical estimators performance in the effort to map the probability-guided pharmacophore pattern. The comprehensive screening of the AChE/BChE profile revealed potentially relevant structural and physicochemical features that might be essential for mapping of the carbamates inhibition efficiency indicating qualitative variations exerted on the reaction site by the substituent in the 3'-/4'-position of the phenyl ring. In addition, the investigation was completed by a molecular docking study of recombinant human AChE.

Synthesis of specifically deuterated S-benzylcysteines and of oxytocin and related diastereomers deuterated in the half-cystine positions

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

Upson, D.A.; Hruby, V.J.

1976-04-16

S-Benzylcysteine derivatives specifically deuterated at the ..cap alpha.. carbon only, the ..beta.. carbon only, and at both the ..cap alpha.. and ..beta.. carbons have been synthesized. These labeled compounds have been enzymatically resolved and the enantiomers and reacemates have been converted to the N-tert-butyloxycarbonyl derivatives. The deuterium labels were not exchanged under the conditions of the syntheses. Condensation of the sodium salt of diethyl ..cap alpha..-acetami-domalonate with benzyl chloromethyl sulfide followed by hydrolysis with DCl afforded S-benzyl-DL-(..cap alpha..-/sup 2/H/sub 1/) cysteine. Acetylation followed by treatment with hog renal acylase separated the stereoisomers. A Mannich reaction with (/sup 2/H/sub 2/) methylenemore » diacetate, diethyl ..cap alpha..-acetamido-..cap alpha..-dimethylamino(/sup 2/H/sub 2/)methylmalonate methiodide (15). Treatment of 15 with sodium benzylmercaptide gave diethyl ..cap alpha..-acetamido-..cap alpha..-benzylthio(/sup 2/H/sub 2/)methylmalonate, which was hydrolyzed with HCl to yield S-benzyl-DL-(..beta..,..beta..-/sup 2/H/sub 2/)cysteine or with DCl to afford S-benzyl-DL-(..cap alpha..,..beta..,..beta..,-/sup 2/H/sub 3/)cysteine. These compounds were resolved as before. The preparation of S-benzyl-DL-(..cap alpha..,..beta..,..beta..-/sup 2/H/sub 3/)cysteine required an efficient source of ethanol-d. This deuterated solvent was prepared in quantitative yield in 2 h from tetraethoxysilane, D/sub 2/O, and a catalytic amount of thionyl chloride. The protected deuterated amino acids were used in the preparation of several oxytocin analogues in which the specific deuteration appears in either the 1-hemicystine or the 6-hemicystine residues.« less

Use of cyclodextrins as a cosmetic delivery system for fragrance materials: linalool and benzyl acetate.

PubMed

Numanoğlu, Ulya; Sen, Tangül; Tarimci, Nilüfer; Kartal, Murat; Koo, Otilia M Y; Onyüksel, Hayat

2007-10-19

The aim of this study was to increase the stability and water solubility of fragrance materials, to provide controlled release of these compounds, and to convert these substances from liquid to powder form by preparing their inclusion complexes with cyclodextrins (CDs). For this purpose, linalool and benzyl acetate were chosen as the fragrance materials. The use of beta-cyclodextrin (beta CD) and 2-hydroxypropyl-beta-cyclodextrin (2-HP beta CD) for increasing the solubility of these 2 fragrance materials was studied. Linalool and benzyl acetate gave a B-type diagram with beta CD, whereas they gave an A(L)-type diagram with 2-HP beta CD. Therefore, complexes of fragrance materials with 2-HP beta CD at 1:1 and 1:2 molar ratios (guest:host) were prepared. The formation of inclusion complexes was confirmed using proton nuclear magnetic resonance ((1)H-NMR) spectroscopy and circular dichroism spectroscopy. The results of the solubility studies showed that preparing the inclusion complex with 2-HP beta CD at a 1:1 molar ratio increased the solubility of linalool 5.9-fold and that of benzyl acetate 4.2-fold, whereas the complexes at a 1:2 molar ratio increased the solubility 6.4- and 4.5-fold for linalool and benzyl acetate, respectively. The stability and in vitro release studies were performed on the gel formulations prepared using uncomplexed fragrance materials or inclusion complexes of fragrance materials at a 1:1 molar ratio. It was observed that the volatility of both fragrance materials was decreased by preparing the inclusion complexes with 2-HP beta CD. Also, in vitro release data indicated that controlled release of fragrances could be possible if inclusion complexes were prepared.

Homogeneous Palladium-Catalyzed Transfer Hydrogenolysis of Benzylic Alcohols Using Formic Acid as Reductant.

PubMed

Ciszek, Benjamin; Fleischer, Ivana

2018-04-12

Herein we report the first homogeneous palladium-based transfer hydrogenolysis of benzylic alcohols using an in situ formed palladium-phosphine complex and formic acid as reducing agent. The reaction requires a catalyst loading as low as only 1 mol% of palladium and just a slight excess of reductant to obtain the deoxygenated alkylarenes in good to excellent yields. Besides demonstrating the broad applicability for primary, secondary and tertiary benzylic alcohols, a reaction intermediate could be identified. Additionally, it could be shown that partial oxidation of the applied phosphine ligand was beneficial for the course of the reaction, presumably by stabilizing the active catalyst. Reaction profiles and catalyst poisoning experiments were used to characterize the catalyst, the results indicate a homogeneous metal complex as active species. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

[Quality control of Maca (Lepidium meyenii)].

PubMed

Shu, Ji-cheng; Cui, Hang-qing; Huang, Ying-zheng; Huang, Xiao-ying; Yang, Ming

2015-12-01

To control the quality of Maca, the quality standard was established in this study. According to the methods recorded in the Appendix of Chinese Pharmacopoeia (2010 Edition), the water, extract, total ash, acid insoluble substance, and heavy metals inspections in Lepidium meyenii were carried out. N-benzyl-9Z, 12Z-octadecadienamide in L. meyenii was identified by TLC, and it was determined by HPLC. The results showed that the N-benzyl-9Z, 12Z-octadecadienamide identification of TLC was a strong mark and specificity. In content determination experiment, the linearity of N-benzyl-9Z, 12Z-octadecadienamide was in the range of 0.01-2 microg (r = 0.9998), and the average recovery (n=9) was 99.27% (RSD 2.0%). The methods were simple, accurate, with good reproducibility. It is suitable for quality control L. meyenii.

Interaction of some extreme-pressure type lubricating compounds with an iron surface

NASA Technical Reports Server (NTRS)

Buckley, D. H.

1973-01-01

An iron surface was exposed to the extreme-pressure type lubricant benzyl chloride, dichlorophenyl phosphine, dichlorophenyl phosphine sulfide, ophenyl phosphine oxide. Iron, in the sputter-cleaned state, was exposed to these materials statically and during dynamic friction experiments. With benzyl chloride only chlorine adsorbed to the surface, and with dichlorophenyl phosphine no adsorption occurred, while the addition of sulfur to that same molecular structure resulted in the promotion of carbon and chlorine adsorption. substitution of oxygen for sulfur in the dichlorobenzyl phosphine molecule resulted in carbon, chlorine, and oxygen adsorption. With none of the phosphorus containing molecules was phosphorus detected on the surface. Sliding in an atmosphere of benzyl chloride promoted adsorption of chlorine to the iron surface. Increases in load resulted in a decrease in the surface concentration of iron chloride.

Enantiomeric resolution of p-toluenesulfonate of valine benzyl ester by preferential crystallizaion.

PubMed

Munegumi, Toratane; Wakatsuki, Aiko; Takahashi, Yutaro

2012-02-01

Preferential crystallization of amino acid derivatives by seeding a pure enantiomer into racemic amino acid solutions has been studied for many years. However, few examples of valine derivatives have been reported so far. Although there have been some reports using valine hydrogen chloride with preferential crystallization, it is difficult to obtain optical isomers for valine derivatives using preferential crystallization. In this study, repeated preferential crystallization of p-toluenesulfonate valine benzyl ester with a 20% e.e. in 2-propanol gave a 94% e.e. on sonication. Sonication accelerated crystallization rate, but there was not a big difference in e.e. between with and without sonication. However, this research demonstrates the first preferential crystallization of p-toluenesulfonate of valine benzyl esters with an acceleration of crystallization using sonication. Copyright © 2011 Wiley Periodicals, Inc.

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.

Architecture of the hydrophobic and hydrophilic layers as found from crystal structure analysis of N-benzyl-N,N-dimethylalkylammonium bromides.

PubMed

Hodorowicz, Maciej; Stadnicka, Katarzyna; Czapkiewicz, Jan

2005-10-01

The molecular and crystal structures of N-benzyl-N,N-dimethylalkylammonium bromides monohydrates with chain length n=8-10 have been determined. The crystals are isostructural with the N-benzyl-N,N-dimethyldodecylammonium bromide monohydrate. The structures consist of alternated hydrophobic and hydrophilic layers perpendicular to [001]. The attraction between N+ of the cation head-groups and Br- anions is achieved through weak C_H...Br interactions. The water molecules incorporated into ionic layers are donors for two O_H...Br hydrogen bonds and serve as the acceptors in two weak interactions of C_H...O type. The methylene chains, with the slightly curved general shape, have the extended all-trans conformation. The mutual packing of the chains in the hydrophobic layers is governed by weak C_H...pi interactions.

Towards a fragment-based approach in gelator design: halogen effects leading to thixotropic, mouldable and self-healing systems in aryl-triazolyl amino acid-based gelators!

PubMed

Srivastava, Bhartendu K; Manheri, Muraleedharan K

2017-04-18

A simple replacement of a H atom by Br transformed non-gelating aryl triazolyl amino acid benzyl ester into a versatile gelator, which formed shape-persistent, self-healing and mouldable gels. The 'bromo-aryl benzyl ester' fragment was then transplanted into another framework, which resulted in similar solvent preference and gelation efficiency.

Solar photochemical oxidations of benzylic and allylic alcohols using catalytic organo-oxidation with DDQ: application to lignin models.

PubMed

Walsh, Katie; Sneddon, Helen F; Moody, Christopher J

2014-10-03

Visible light has a dramatic effect on the oxidation of benzylic and allylic alcohols, including those deactivated by electron-withdrawing groups, and β-O-4 lignin models, using catalytic amounts of the organo-oxidant 2,3-dichloro-5,6-dicyano-1,4-benzoquinone. Sodium nitrite or tert-butyl nitrite is used as cocatalyst, and oxygen is employed as the terminal oxidant.

Synthesis of unsymmetrical benzil licoagrodione.

PubMed

Worayuthakarn, Rattana; Boonya-udtayan, Sasiwadee; Arom-oon, Eakarat; Ploypradith, Poonsakdi; Ruchirawat, Somsak; Thasana, Nopporn

2008-09-19

A synthesis of unsymmetrical 1,2-diarylethane-1,2-dione is reported involving the intramolecular cyclization of anionic benzylic ester of the aryl benzyl ether followed by oxidation employing dioxirane. With the use of microwave irradiation, licoagrodione was prepared from Claisen rearrangement of the corresponding allyl phenyl ether 1,2-diketone readily available from the Lindlar's reduction of the corresponding alkyne derivative. Subsequent removal of protecting groups then furnished the desired product.

Optimization of Microencapsulation Composition of Menthol, Vanillin, and Benzyl Acetate inside Polyvinyl Alcohol with Coacervation Method for Application in Perfumery

NASA Astrophysics Data System (ADS)

Sahlan, Muhamad; Raihani Rahman, Mohammad

2017-07-01

One of many applications of essential oils is as fragrance in perfumery. Menthol, benzyl acetate, and vanillin, each represents olfactive characteristic of peppermint leaves, jasmine flowers, and vanilla beans, are commonly used in perfumery. These components are highly volatile, hence the fragrance components will quickly evaporate resulting in short-lasting scent and low shelf life. In this research, said components have been successfully encapsulated simultaneously inside Polyvinyl Alcohol (PVA) using simple coacervation method to increase its shelf life. Optimization has been done using Central Composite Diagram with 4 independent variables, i.e. composition of menthol, benzyl acetate, vanillin, and tergitol 15-S-9 (as emulsifier). Encapsulation efficiency, loading capacity, and microcapsule size have been measured. In optimized composition of menthol (13.98 %w/w), benzyl acetate (14.75 %w/w), vanillin (17.84 %w/w), and tergitol 15-S-9 (13.4 %w/w) encapsulation efficiency of 97,34% and loading capacity of 46,46% have been achieved. Mean diameter of microcapsule is 20,24 μm and within range of 2,011-36,24 μm. Final product was achieved in the form of cross linked polyvinyl alcohol with hydrogel consistency and orange to yellow in color.

Synthesis of methyl 2-O-alpha-D-mannopyranosyl-alpha-D-talopyranoside and methyl 2-O-alpha-D-talopyranosyl-alpha-D-talopyranoside.

PubMed

Jain, R K; Dubey, R; Abbas, S A; Matta, K L

1987-03-15

Treatment of methyl 3-O-benzyl-2-O-(2,3,4,6-tetra-O-acetyl-alpha-D-mannopyranosyl)-alpha-D- mannopyranoside (1) with tert-butyldiphenylsilyl chloride in N,N-dimethylformamide afforded methyl 3-O-benzyl-6-O-tert-butyldiphenylsilyl-2-O-(2,3,4,6-tetra-O-acetyl -alpha-D- mannopyranosyl)-alpha-D-mannopyranoside (2). Oxidation of 2 with pyridinium chlorochromate, followed by reduction of the carbonyl group, and subsequent O-deacetylation afforded methyl 3-O-benzyl-6-O-tert-butyldiphenylsilyl-2-O-alpha-D-mannopyranosyl- alpha-D- talopyranoside (5). Cleavage of the tert-butyldiphenylsilyl group of 5 with tetrabutylammonium fluoride in oxolane, followed by hydrogenolysis, gave methyl 2-O-alpha-D-mannopyranosyl-alpha-D-talopyranoside (7). O-Deacetylation of 1 gave methyl 3-O-benzyl-2-O-alpha-D-mannopyranosyl-alpha-D-mannopyranoside (8). Treatment of 8 with tert-butyldiphenylsilyl chloride afforded a 6,6'-disilyl derivative, which was converted into a 2',3'-O-isopropylidene derivative, and then further oxidized with pyridinium chlorochromate. The resulting diketone was reduced and removal of the protecting groups gave methyl 2-O-alpha-D-talopyranosyl-alpha-D-talopyranoside (15). The structures of both 7 and 15 were established by 13C-n.m.r. spectroscopy.

Benzylpyrazinium Salts as Photo-Initiators in the Polymerization of Epoxide Monomers

PubMed Central

Kim, Moon Suk; Lee, Sang Bong

2014-01-01

In order to study the capability of pyrazinium salt derivatives to act as photo-initiators of epoxide monomers, benzyl pyrazinium hexafluoroantimonate (BPH), benzyl 3,5-dimethyl pyrazine hexafluoroantimonate (BDH) and benzyl quinoxalinium hexafluoroantimonate (BQH) were synthesized by the Menschutkin reaction of benzyl bromide with pyrazine, 2,6-dimethyl pyrazine, and quinoxaline, followed by exchanging with hexafluoroantimonate (SbF6). BPH, BDH, and BQH exhibited characteristic ultraviolet (UV) absorbance as well as exothermic peaks as a function of irradiation time in a differential photo-calorimeter (DPC). In the absence of photo-irradiation, cyclohexene oxide (CHO) underwent slow polymerization at 25 °C using BPH derivatives, but quantitative conversion was achieved even after a 5-min photo-irradiation. In addition, photo-irradiation was required for the photo-polymerization of CHO and styrene oxide (STO), which was characterized by a short induction period followed by a very rapid and exothermic polymerization. While glycidyl methyl ether (GME) required long induction periods, glycidyl phenyl ether (GPE) underwent rather slow and/or no photo-polymerization. The reactivity order of the monomers was CHO > STO >> GME >>> GPE, and the reactivity order for the photo-polymerization of CHO was BPH > BQH > BDH. It was found that BPH, BDH, and BQH could serve as photo-latent initiators for CHO, STO and GME, respectively. PMID:28788147

Benzylpyrazinium Salts as Photo-Initiators in the Polymerization of Epoxide Monomers.

PubMed

Kim, Moon Suk; Lee, Sang Bong

2014-07-31

In order to study the capability of pyrazinium salt derivatives to act as photo-initiators of epoxide monomers, benzyl pyrazinium hexafluoroantimonate (BPH), benzyl 3,5-dimethyl pyrazine hexafluoroantimonate (BDH) and benzyl quinoxalinium hexafluoroantimonate (BQH) were synthesized by the Menschutkin reaction of benzyl bromide with pyrazine, 2,6-dimethyl pyrazine, and quinoxaline, followed by exchanging with hexafluoroantimonate (SbF₆). BPH, BDH, and BQH exhibited characteristic ultraviolet (UV) absorbance as well as exothermic peaks as a function of irradiation time in a differential photo-calorimeter (DPC). In the absence of photo-irradiation, cyclohexene oxide (CHO) underwent slow polymerization at 25 °C using BPH derivatives, but quantitative conversion was achieved even after a 5-min photo-irradiation. In addition, photo-irradiation was required for the photo-polymerization of CHO and styrene oxide (STO), which was characterized by a short induction period followed by a very rapid and exothermic polymerization. While glycidyl methyl ether (GME) required long induction periods, glycidyl phenyl ether (GPE) underwent rather slow and/or no photo-polymerization. The reactivity order of the monomers was CHO > STO > GME > GPE, and the reactivity order for the photo-polymerization of CHO was BPH > BQH > BDH. It was found that BPH, BDH, and BQH could serve as photo-latent initiators for CHO, STO and GME, respectively.

Fundamental understanding of drug absorption from a parenteral oil depot.

PubMed

Kalicharan, Raween W; Schot, Peter; Vromans, Herman

2016-02-15

Oil depots are parenteral drug formulations meant for sustained release of lipophilic compounds. Until now, a comprehensive understanding of the mechanism of drug absorption from oil depots is lacking. The aim of this paper was to fill this gap. A clinical study with healthy volunteers was conducted. An oil depot with nandrolone decanoate and benzyl alcohol was subcutaneously administered in the upper arm of female volunteers. Pharmacokinetic profiles of both substances were related to each other and to literature data. Benzyl alcohol absorbs much more rapidly than nandrolone. In detail, it appears that benzyl alcohol enters the central compartment directly, while nandrolone decanoate is recovered in serum after a lag time. This lag time is also seen in literature data, although not reported explicitly. The absorption of nandrolone is enhanced by the presence of benzyl alcohol. This is most likely an effect of altered oil viscosity and partition coefficient between the oil and aqueous phase. The absorption rate constant of compounds is found to be related to the logP of the solubilized prodrug. The absorption rate is however not only determined by the physico-chemical properties of the formulation but also by the tissue properties. Here, it is argued that lymphatic flow must be considered as a relevant parameter. Copyright © 2015 Elsevier B.V. All rights reserved.

Analysis of a microbial community oxidizing inorganic sulfide and mercaptans.

PubMed

Duncan, K E; Sublette, K L; Rider, P A; Stepp, A; Beitle, R R; Conner, J A; Kolhatkar, R

2001-01-01

Successful treatment of refinery spent-sulfidic caustic (which results from the addition of sodium hydroxide solutions to petroleum refinery waste streams) was achieved in a bioreactor containing an enrichment culture immobilized in organic polymer beads with embedded powdered activated carbon (Bio-Sep). The aerobic enrichment culture had previously been selected using a gas mixture of hydrogen sulfide and methyl mercaptan (MeSH) as the sole carbon and energy sources. The starting cultures for the enrichment consisted of several different Thiobacilli spp. (T. thioparus, T. denitrificans, T. thiooxidans, and T. neopolitanus), as well as activated sludge from a refinery aerobic wastewater treatment system and sludge from an industrial anaerobic digester. Microscopic examination (light and SEM) of the beads and of microbial growth on the walls of the bioreactor revealed a great diversity of microorganisms. Further characterization was undertaken starting with culturable aerobic heterotrophic microorganisms (sequencing of PCR-amplified DNA coding for 16S rRNA, Gram staining) and by PCR amplification of DNA coding for 16S rRNA extracted directly from the cell mass, followed by the separation of the PCR products by DGGE (denaturing gradient gel electrophoresis). Eight prominent bands from the DGGE gel were sequenced and found to be closest to sequences of uncultured Cytophagales (3 bands), Gram-positive cocci (Micrococcineae), alpha proteobacteria (3 bands), and an unidentified beta proteobacterium. Culturable microbes included several genera of fungi as well as various Gram-positive and Gram-negative heterotrophic bacteria not seen in techniques using direct DNA extraction.

Optical bio-sniffer for methyl mercaptan in halitosis.

PubMed

Mitsubayashi, Kohji; Minamide, Takeshi; Otsuka, Kimio; Kudo, Hiroyuki; Saito, Hirokazu

2006-07-28

An optical bio-sniffer for methyl mercaptan (MM) one of major odorous chemicals in halitosis (bad breath) was constructed by immobilizing monoamine oxidase type A (MAO-A) onto a tip of a fiber optic oxygen sensor (od: 1.59 mm) with an oxygen sensitive ruthenium organic complex (excitation: 470 nm, fluorescent: 600 nm). A flow cell for circulating buffer solution was applied to rinse and clean the tip of the device like nasal mucosa. In order to amplify the bio-sniffer output, a substrate regeneration cycle caused by coupling MAO-A with l-ascorbic acid (AsA) as reducing reaction with reagent system was applied to the sensor system. After evaluating the sensor characteristics using a gas flow measurement system with a gas generator, the optical bio-sniffer was applied to expired gases from healthy male volunteers for halitosis analysis as a physiological application. The optical bio-sniffer was applied to detect the oxygen consumption induced by MAO-A enzymatic reaction (and AsA chemical reduction) with gaseous MM application. The bio-sniffer was calibrated against MM vapor from 8.7 to 11500 ppb with correlation coefficient of 0.977, including a MM threshold (200 ppb) of pathologic halitosis and the human sense of smell level 3.5 (10.0 ppb), with good gas-selectivity based on the MAO-A substrate specificity. As the result of the physiological application, the optical bio-sniffer could successfully monitor the MM level change in breath samples during daytime, which is consistent with the previously reported results.

Multiple Pathways for Benzyl Alcohol Oxidation by Ru V =O 3+ and Ru IV =O 2+

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

Paul, Amit; Hull, Jonathan F.; Norris, Michael R.

2011-02-21

Significant rate enhancements are found for benzyl alcohol oxidation by the RuV=O3+ form of the water oxidation catalyst [Ru(Mebimpy)(bpy)(OH2)]2+ [Mebimpy = 2,6-bis(1-methylbenzimidazol-2-yl)pyridine; bpy = 2,2'-bipyridine] compared to RuIV=O2+ and for the RuIV=O2+ form with added bases due to a new pathway, concerted hydride proton transfer (HPT).

Multiple Pathways for Benzyl Alcohol Oxidation by Ru V=O 3+ and Ru IV=O 2+

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

Paul, Amit; Hull, Jonathan F.; Norris, Michael R.

2011-01-20

Significant rate enhancements are found for benzyl alcohol oxidation by the Ru V=O 3+ form of the water oxidation catalyst [Ru(Mebimpy)(bpy)(OH 2)] 2+ [Mebimpy = 2,6-bis(1-methylbenzimidazol-2-yl)pyridine; bpy = 2,2'-bipyridine] compared to Ru IV=O 2+ and for the Ru IV=O 2+ form with added bases due to a new pathway, concerted hydride proton transfer (HPT).

Reusable ionic liquid-catalyzed oxidative coupling of azoles and benzylic compounds via sp(3) C-N bond formation under metal-free conditions.

PubMed

Liu, Wenbo; Liu, Chenjiang; Zhang, Yonghong; Sun, Yadong; Abdukadera, Ablimit; Wang, Bin; Li, He; Ma, Xuecheng; Zhang, Zengpeng

2015-07-14

The heterocyclic ionic liquid-catalyzed direct oxidative amination of benzylic sp(3) C-H bonds via intermolecular sp(3) C-N bond formation for the synthesis of N-alkylated azoles under metal-free conditions is reported for the first time. The catalyst 1-butylpyridinium iodide can be recycled and reused with similar efficacies for at least eight cycles.

N-Benzyl­pyridin-2-amine

PubMed Central

Wang, Jun; Dai, Chuntao; Nie, Jianhua

2010-01-01

In the crystal of the title compound, C12H12N2, inter­molecular N—H⋯N hydrogen bonds form rings of graph-set motif R 2 2(8) and C—H⋯π inter­actions further consolidate the dimers. Neighbouring dimers are further connected into a three-dimensional network by C—H⋯π inter­actions. The benzyl and pyridyl rings form a dihedral angle of 67.2 (1)° PMID:21589385

Highly efficient oxidation of amines to imines by singlet oxygen and its application in Ugi-type reactions.

PubMed

Jiang, Gaoxi; Chen, Jian; Huang, Jie-Sheng; Che, Chi-Ming

2009-10-15

A variety of secondary benzylic amines were oxidized to imines in 90% to >99% yields by singlet oxygen generated from oxygen and a porphyrin photosensitizer. On the basis of these reactions, a protocol was developed for oxidative Ugi-type reactions with singlet oxygen as the oxidant. This protocol has been used to synthesize C1- and N-functionalized benzylic amines in up to 96% yields.

Crystal structures of HIV-1 nonnucleoside reverse transcriptase inhibitors: N-benzyl-4-methyl-benzimidazoles

NASA Astrophysics Data System (ADS)

Ziółkowska, Natasza E.; Michejda, Christopher J.; Bujacz, Grzegorz D.

2009-07-01

HIV-1 nonnucleoside reverse transcriptase inhibitors are potentially specific and effective drugs in AIDS therapy. The presence of two aromatic systems with an angled orientation in the molecule of the inhibitor is crucial for interactions with HIV-1 RT. The inhibitor drives like a wedge into the cluster of aromatic residues of RT HIV-1 and restrains the enzyme in a conformation that blocks the chemical step of nucleotide incorporation. Structural studies provide useful information for designing new, more active inhibitors. The crystal structures of four NNRTIs are presented here. The investigated compounds are derivatives of N-benzyl-4-methyl-benzimidazole with various aliphatic and aromatic substituents at carbon 2 positions and a 2,6-dihalogeno-substituted N-benzyl moiety. Structural data reported here show that the conformation of the investigated compounds is relatively rigid. Such feature is important for the nonnucleoside inhibitor binding to HIV-1 reverse transcriptase.

A comparative analysis of characteristic floral scent compounds in Prunus mume and related species.

PubMed

Hao, Ruijie; Du, Dongliang; Wang, Tao; Yang, Weiru; Wang, Jia; Zhang, Qixiang

2014-01-01

In order to investigate the difference in their characteristic floral scents between Prunus mume Siebold & Zucc. and the related Prunus species, their headspace volatiles and endogenous extraction were analyzed by gas chromatography-mass spectrometry. The efficiency of substrate utilization of the flowers was studied by incubating them with different alcohol substrates. Our results indicated that benzyl acetate is a dominant compound influencing the characteristic floral scent of P. mume. An alcohol substrate concentration of 4 mmol L(-1) and a reaction time of 2 h were constituted the reaction condition for catalysis of exogenous alcohol substrates by the flowers. Under these conditions, Prunus sibirica exhibited the highest utilization efficiency for benzyl alcohol substrate while the utilization efficiency of Prunus persica was the lowest. Comparative analysis of several alcohol substrates indicated that the flowers of the tested species had selective specificity for benzyl alcohol substrates.

Cobalt co-catalysis for cross-electrophile coupling: diarylmethanes from benzyl mesylates and aryl halides† †Electronic supplementary information (ESI) available. See DOI: 10.1039/c4sc03106g Click here for additional data file.

PubMed Central

Ackerman, Laura K. G.; Anka-Lufford, Lukiana L.; Naodovic, Marina

2015-01-01

The nickel-catalyzed cross-coupling of aryl halides with alkyl radicals derived from alkyl halides has recently been extended to couplings with carbon radicals generated by a co-catalyst. In this study, a new co-catalyst, cobalt phthalocyanine (Co(Pc)), is introduced and demonstrated to be effective for coupling substrates not prone to homolysis. This is because Co(Pc) reacts with electrophiles by an SN2 mechanism instead of by the electron-transfer or halogen abstraction mechanisms previously explored. Studies demonstrating the orthogonal reactivity of (bpy)Ni and Co(Pc), applying this selectivity to the coupling of benzyl mesylates with aryl halides, and the adaptation of these conditions to the less reactive benzyl phosphate ester and an enantioconvergent reaction are presented. PMID:25685312

In Vitro Activity of Cephalothin and Three Penicillins Against Escherichia coli and Proteus Species

PubMed Central

Barry, Arthur L.; Hoeprich, Paul D.

1973-01-01

The susceptibility of clinical isolates of Escherichia coli (67) and Proteus species (58) to cephalothin, ampicillin, benzyl penicillin, and phenoxymethyl penicillin was determined in vitro by using broth dilution and disk diffusion tests. The data were correlated by using a four-category scheme for interpreting minimal inhibitory concentrations (groups 1 to 4) as recommended by a subcommittee of an international collaborative study of susceptibility testing. With cephalothin and ampicillin, groups 1 (susceptible) and 2 (moderately susceptible) were susceptible by the disk test, and with benzyl penicillin, similar results were observed when the interpretive zone standards were changed. Strains categorized as group 4 (very resistant) were resistant by the disk method, but group 3 (moderately resistant) strains were not adequately distinguished by disk testing. Group 3 susceptibility to benzyl and phenoxymethyl penicillins can be predicted by extrapolating results from tests with ampicillin disks. PMID:4202343

Pyridylthiazole-based ureas as inhibitors of Rho associated protein kinases (ROCK1 and 2)†

PubMed Central

Pireddu, Roberta; Forinash, Kara D.; Sun, Nan N.; Martin, Mathew P.; Sung, Shen-Shu; Alexander, Brian; Zhu, Jin-Yi; Guida, Wayne C.; Schönbrunn, Ernst; Sebti, Saïd M.; Lawrence, Nicholas J.

2012-01-01

Potent ROCK inhibitors of a new class of 1-benzyl-3-(4-pyridylthiazol-2-yl)ureas have been identified. Remarkable differences in activity were observed for ureas bearing a benzylic stereogenic center. Derivatives with hydroxy, methoxy and amino groups at the meta position of the phenyl ring give rise to the most potent inhibitors (low nM). Substitutions at the para position result in substantial loss of potency. Changes at the benzylic position are tolerated resulting in significant potency in the case of methyl and methylenehydroxy groups. X-Ray crystallography was used to establish the binding mode of this class of inhibitors and provides an explanation for the observed differences of the enantiomer series. Potent inhibition of ROCK in human lung cancer cells was shown by suppression of the levels of phosphorylation of the ROCK substrate MYPT-1. PMID:23275831

Quantitative Structure-Activity Relationship of Insecticidal Activity of Benzyl Ether Diamidine Derivatives

NASA Astrophysics Data System (ADS)

Zhai, Mengting; Chen, Yan; Li, Jing; Zhou, Jun

2017-12-01

The molecular electrongativity distance vector (MEDV-13) was used to describe the molecular structure of benzyl ether diamidine derivatives in this paper, Based on MEDV-13, The three-parameter (M 3, M 15, M 47) QSAR model of insecticidal activity (pIC 50) for 60 benzyl ether diamidine derivatives was constructed by leaps-and-bounds regression (LBR) . The traditional correlation coefficient (R) and the cross-validation correlation coefficient (R CV ) were 0.975 and 0.971, respectively. The robustness of the regression model was validated by Jackknife method, the correlation coefficient R were between 0.971 and 0.983. Meanwhile, the independent variables in the model were tested to be no autocorrelation. The regression results indicate that the model has good robust and predictive capabilities. The research would provide theoretical guidance for the development of new generation of anti African trypanosomiasis drugs with efficiency and low toxicity.

Influence of gamma irradiation and benzyl adenine on keeping quality of custard apple fruits during storage.

PubMed

Chouksey, Swati; Singh, Alpana; Thakur, Rajendra Singh; Deshmukh, Reena

2013-10-01

The custard apple (Annona squamosa) fruits were procured from local market, irradiated with radiation doses 0, 0.25, 0.50, 0.75, 1.00, 1.25, 1.50, 1.75 kGy and then treated with benzyl adenine (50 and 100 part per million) and stored at ambient temperature (25 ± 5 °C, Relative Humidity 90 ± 2%) for 12 days. The treated fruits were evaluated for sensory (viz; flavour, texture, internal and external colour) and chemical constituents (viz; Total Soluble Solids, titrable acidity, ascorbic acid, free soluble sugar, reducing sugar. non reducing sugar, carbohydrate) during storage. The study concluded that radiation dose of 1.5 kilo Gray along with 50 ppm benzyl adenine enhanced in shelf-life of custard apple fruits by 6 days at ambient temperature with good pulp texture, flavour, colour and nutritional quality as compared to control.

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

Multiple Pathways for Benzyl Alcohol Oxidation by Ru V=O 3+ and Ru IV=O 2+

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

Paul, Amit; Hull, Jonathan F.; Norris, Michael R.

2011-01-20

Significant rate enhancements are found for benzyl alcohol oxidation by the Ru V=O 3+ form of the water oxidation catalyst [Ru(Mebimpy)(bpy)(OH 2)] 2+ [Mebimpy = 2,6-bis(1-methylbenzimidazol-2-yl)pyridine; bpy = 2,2'-bipyridine] compared to Ru IV=O 2+ and for the Ru IV=O 2+ form with added bases due to a new pathway involving concerted hydride proton transfer (HPT).

Regeneration of Stevia Plant Through Callus Culture

PubMed Central

Patel, R. M.; Shah, R. R.

2009-01-01

Stevia rebaudiana Bertoni that conventionally propagated by seed or by cuttings or clump division which has a limitation of quality and quantity seed material. In present study, callus culture technique was tried to achieve rapid plant multiplication for quality seed material. Callus induction and multiplication medium was standardized from nodal as well as leaf sagments. It is possible to maintain callus on Murashige and Skoog medium supplemented with 6-benzyl amino purine and naphthalene acetic acid. Maximum callus induction was obtained on Murashige and Skoog medium incorporated with 6-benzyl amino purine (2.0-3.0 mg/l) and naphthalene acetic acid (2.0 mg/l) treatments. However, Murashige and Skoog medium containing 2.0 mg/l 6-benzyl amino purine+2.0 mg/l naphthalene acetic acid was found to be the best for callus induction. Higher regeneration frequency was noticed with Murashige and Skoog medium supplemented with 2.0 mg/l 6-benzyl amino purine+0.2 mg/l naphthalene acetic acid. Regenerated plants were rooted better on ¼ Murashige and Skoog strength supplemented with 0.1 mg/l indole-3-butyric acid. The rooted plantlets were hardened successfully in tera care medium with 63 per cent survival rate. The developed protocol can be utilized for mass production of true to type planting material on large scale independent of season, i.e. external environmental conditions. PMID:20177455

Dehydrogenation and dehalogenation of amines in MALDI-TOF MS investigated by isotopic labeling.

PubMed

Kang, Chuanqing; Zhou, Yihan; Du, Zhijun; Bian, Zheng; Wang, Jianwei; Qiu, Xuepeng; Gao, Lianxun; Sun, Yuequan

2013-12-01

Secondary and tertiary amines have been reported to form [M-H](+) that correspond to dehydrogenation in matrix-assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF MS). In this investigation, we studied the dehydrogenation of amines in MALDI-TOF MS by isotopic labeling. Aliphatic amines were labeled with deuterium on the methylene of an N-benzyl group, which resulted in the formation of [M-D](+) and [M-H](+) ions by dedeuteration and dehydrogenation, respectively. This method revealed the proton that was removed. The spectra of most tertiary amines with an N-benzyl group showed high-intensity [M-D](+) and [M-H](+) ion peaks, whereas those of secondary amines showed low-intensity ion peaks. Ratios between the peak intensities of [M-D](+) and [M-H](+) greater than 1 suggested chemoselective dehydrogenation at the N-benzyl groups. The presence of an electron donor group on the N-benzyl groups enhanced the selectivity. The dehalogenation of amines with an N-(4-halobenzyl) group was also observed alongside dehydrogenation. The amino ions from dehalogenation can undergo second dehydrogenation. These results provide the first direct evidence about the position at which dehydrogenation of an amine occurs and the first example of dehalogenation of haloaromatic compounds in MALDI-TOF MS. These results should be helpful in the structural identification and elucidation of synthetic and natural molecules. Copyright © 2013 John Wiley & Sons, Ltd.

Evaluation of Antitrypanosomal Dihydroquinolines for Hepatotoxicity, Mutagenicity, and Methemoglobin Formation In Vitro.

PubMed

Werbovetz, Karl A; Riccio, Edward S; Furimsky, Anna; Richard, Julian V; He, Shanshan; Iyer, Lalitha; Mirsalis, Jon

2014-07-01

N1-Benzylated dihydroquinolin-6-ols and their corresponding esters display exceptional activity against African trypanosomes in vitro, and administration of members of this class of compounds to trypanosome-infected mice results in cures in a first-stage African trypanosomiasis model. Since a quinone imine intermediate has been implicated in the antiparasitic mechanism of action of these compounds, evaluation of the hepatotoxic, mutagenic, and methemoglobin-promoting effects of these agents was performed. 1-Benzyl-1,2-dihydro-2,2,4-trimethylquinolin-6-ol hydrochloride and 1-benzyl-1,2-dihydro-2,2,4-trimethylquinolin-6-yl acetate showed outstanding in vitro selectivity for Trypanosoma brucei compared to the HepG2, Hep3B, Huh7, and PLC5 hepatocyte cell lines. 1-Benzyl-1,2-dihydro-2,2,4-trimethylquinolin-6-ol hydrochloride and 1-(2-methoxybenzyl)-1,2-dihydro-2,2,4-trimethylquinolin-6-yl acetate were not mutagenic when screened in the Ames assay, with or without metabolic activation. The latter 2 compounds promoted time- and dose-dependent formation of methemoglobin when incubated in whole human blood, but such levels were below those typically required to produce symptoms of methemoglobinemia in humans. Although compounds capable of quinone imine formation require careful evaluation, these in vitro studies indicate that antitrypanosomal dihydroquinolines merit further study as drug candidates against the neglected tropical disease human African trypanosomiasis. © The Author(s) 2014.

Chemometrics-assisted chromatographic fingerprinting: An illicit methamphetamine case study.

PubMed

Shekari, Nafiseh; Vosough, Maryam; Tabar Heidar, Kourosh

2017-03-01

The volatile chemical constituents in complex mixtures can be analyzed using gas chromatography with mass spectrometry. This analysis allows the tentative identification of diverse impurities of an illicit methamphetamine sample. The acquired two-dimensional data of liquid-liquid extraction was resolved by multivariate curve resolution alternating curve resolution to elucidate the embedded peaks effectively. This is the first report on the application of a curve resolution approach for chromatogram fingerprinting to identify particularly the embedded impurities of a drug of abuse. Indeed, the strong and broad peak of methamphetamine makes identifying the underlying peaks problematic and even impossible. Mathematical separation instead of conventional chromatographic approaches was performed in a way that trace components embedded in methamphetamine peak were successfully resolved. Comprehensive analysis of the chromatogram, using multivariate curve resolution, resulted in elution profiles and mass spectra for each pure compound. Impurities such as benzaldehyde, benzyl alcohol, benzene, propenyl methyl ketone, benzyl methyl ketone, amphetamine, N-benzyl-2-methylaziridine, phenethylamine, N,N,α-trimethylamine, phenethylamine, N,α,α-trimethylmethamphetamine, N-acetylmethamphetamine, N-formylmethamphetamine, and other chemicals were identified. A route-specific impurity, N-benzyl-2-methylaziridine, indicating a synthesis route based on ephedrine/pseudoephedrine was identified. Moreover, this is the first report on the detection of impurities such as phenethylamine, N,α,α-trimethylamine (a structurally related impurity), and clonitazene (as an adulterant) in an illicit methamphetamine sample. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Synthesis, characterization, computational studies and biological evaluation of S-benzyl-β-N-[3-(4-hydroxy-3-methoxy-phenylallylidene)]dithiocarbazate

NASA Astrophysics Data System (ADS)

Bhat, Rayees A.; Kumar, D.; Malla, Manzoor A.; Bhat, Sami U.; Khan, Md Shahzad; Manzoor, Ovais; Srivastava, Anurag; Naikoo, Rawoof A.; Mohsin, Mohd; Mir, Muzzaffar A.

2018-03-01

S-Benzyl-β-N-[3-(4-hydroxy-3-methoxy-phenylallylidene)]dithiocarbazate (HL1), Schiff base of S-benzyl dithiocarbazate, was synthesized by 1:1 condensation between S-benzyl dithiocarbazate and 4-hydroxy-3-methoxy cinnamaldehyde. The nitrogen-sulfur Schiff base (HL1) was characterized by Mass, FT-IR, H1-NMR, Raman, and UV-VIS spectroscopic techniques. Theoretical quantum chemical calculations were performed using DFT in combination with B3LYP exchange correlation functional and 6-311++ G (d, p) basis sets level. The calculated values of chemical potential (μ), HOMO-LUMO energy gap, chemical hardness, softness (S), ionization energy (IE), electron affinity (EA), dipole moment (D) and relative stabilization energy of the compound were 0.14881 eV, 0.12542 eV, 0.06271 eV, 3.37299 eV, -0.21152 eV, -0.08610 eV, 4.4090 Debye and -1753.350 eV respectively. Theoretically calculated parameters like H1-NMR, FT-IR, UV-VIS, Raman, electrostatic potential and HOMO-LUMO energy gap are in good agreement with experimental results. Also, in-vitro cytotoxicity studies were done against two habitually infection causing bacteria strains including gram-positive (S. aureus) and gram-negative (E. coli) for antibacterial activity. The results showed appreciable biological activity and the activity increased with increase in dose.

Oxidation of Naphthenoaromatic and Methyl-Substituted Aromatic Compounds by Naphthalene 1,2-Dioxygenase

PubMed Central

Selifonov, S. A.; Grifoll, M.; Eaton, R. W.; Chapman, P. J.

1996-01-01

Oxidation of acenaphthene, acenaphthylene, and fluorene was examined with recombinant strain Pseudomonas aeruginosa PAO1(pRE695) expressing naphthalene dioxygenase genes cloned from plasmid NAH7. Acenaphthene underwent monooxygenation to 1-acenaphthenol with subsequent conversion to 1-acenaphthenone and cis- and trans-acenaphthene-1,2-diols, while acenaphthylene was dioxygenated to give cis-acenaphthene-1,2-diol. Nonspecific dehydrogenase activities present in the host strain led to the conversion of both of the acenaphthene-1,2-diols to 1,2-acenaphthoquinone. The latter was oxidized spontaneously to naphthalene-1,8-dicarboxylic acid. No aromatic ring dioxygenation products were detected from acenaphthene and acenaphthylene. Mixed monooxygenase and dioxygenase actions of naphthalene dioxygenase on fluorene yielded products of benzylic 9-monooxygenation, aromatic ring dioxygenation, or both. The action of naphthalene dioxygenase on a variety of methyl-substituted aromatic compounds, including 1,2,4-trimethylbenzene and isomers of dimethylnaphthalene, resulted in the formation of benzylic alcohols, i.e., methyl group monooxygenation products, which were subsequently converted to the corresponding carboxylic acids by dehydrogenase(s) in the host strain. Benzylic monooxygenation of methyl groups was strongly predominant over aromatic ring dioxygenation and essentially nonspecific with respect to the substitution pattern of the aromatic substrates. In addition to monooxygenating benzylic methyl and methylene groups, naphthalene dioxygenase behaved as a sulfoxygenase, catalyzing monooxygenation of the sulfur heteroatom of 3-methylbenzothiophene. PMID:16535238

Reappraising the structures and distribution of metabolites from black aspergilli containing uncommon 2-benzyl-4H-pyran-4-one and 2-benzylpyridin-4(1H)-one systems

PubMed Central

Henrikson, Jon C.; Ellis, Trevor K.; King, Jarrod B.; Cichewicz, Robert H.

2011-01-01

To date, natural products containing 2-benzyl-4H-pyran-4-one and 2-benzylpyridin-4(1H)-one substructures have been encountered in relatively few fungi outside of the black aspergilli clade. While exploring the occurrence of these compounds among Aspergillus spp., it was determined that the structures of the unusual furopyrrols tensidols A and B (5 and 6) and JBIR-86 and JBIR-87 (9 and 10) were incorrect and should be reassigned as 2-benzyl-4H-pyran-4-ones (7, 8, 11e, and 12, respectively). The origin of the unique N-phenyl groups in the 2-benzylpyridin-4(1H)-ones nygerones A and B (1 and 2) was also examined and it was established that N-phenylamides added to the culture medium were suitable substrates for generating these metabolites; however, this phenomenon remained limited to a single fungus in our collection (Aspergillus niger ATCC 1015). A variety of 2-benzyl-4H-pyran-4-ones and 2-benzylpyridin-4(1H)-ones were detected among the black aspergilli, but only pestalamide B (13) was found in all eleven of the tested strains. These metabolites, as well as a group of synthetic analogues demonstrated weak antifungal activity against several Candida strains, Aspergillus flavus, and Aspergillus fumigatus. PMID:21854017

Fragrance material review on benzyl alcohol.

PubMed

Scognamiglio, J; Jones, L; Vitale, D; Letizia, C S; Api, A M

2012-09-01

A toxicologic and dermatologic review of benzyl alcohol when used as a fragrance ingredient is presented. Benzyl alcohol is a member of the fragrance structural group Aryl Alkyl Alcohols and is a primary alcohol. The AAAs are a structurally diverse class of fragrance ingredients that includes primary, secondary, and tertiary alkyl alcohols covalently bonded to an aryl (Ar) group, which may be either a substituted or unsubstituted benzene ring. The common structural element for the AAA fragrance ingredients is an alcohol group -C-(R1)(R2)OH and generically the AAA fragrances can be represented as an Ar-C-(R1)(R2)OH or Ar-Alkyl-C-(R1)(R2)OH group. This review contains a detailed summary of all available toxicology and dermatology papers related to this individual fragrance ingredient and is not intended as a stand-alone document. Available data for benzyl alcohol were evaluated then summarized and includes physical properties, acute toxicity, skin irritation, mucous membrane (eye) irritation, skin sensitization, elicitation, phototoxicity, photoallergy, toxicokinetics, repeated dose, reproductive toxicity, genotoxicity, and carcinogenicity data. A safety assessment of the entire Aryl Alkyl Alcohols will be published simultaneously with this document; please refer to Belsito et al. (2012) for an overall assessment of the safe use of this material and all Aryl Alkyl Alcohols in fragrances. Copyright © 2011 Elsevier Ltd. All rights reserved.

Crystal structure of bis-[(phenyl-methanamine-κN)(phthalocyaninato-κ(4) N)zinc] phenyl-methan-amine tris-olvate.

PubMed

Shamsudin, Norzianah; Tan, Ai Ling; Wimmer, Franz L; Young, David J; Tiekink, Edward R T

2015-09-01

The asymmetric unit of the title compound, 2[Zn(C32H16N8)(C7H9N)]·3C7H9N, comprises two independent complex mol-ecules and three benzyl-amine solvent mol-ecules. Each complex mol-ecule features a penta-coordinated Zn(2+) ion within a square-pyramidal geometry, whereby the N5 donor set is defined by four atoms of the phthalocyaninate dianion (PC) and an N-bound benzyl-amine mol-ecule; it is the relative orientations of the latter that differentiate between the independent complex mol-ecules. The uncoordinated benzyl-amine mol-ecules display different conformations in the structure, with syn-Car-Car-Cm-N (ar = aromatic, m = methyl-ene) torsion angles spanning the range -28.7 (10) to 35.1 (14)°. In the crystal, N-H⋯N and N-H⋯π inter-actions lead to supra-molecular layers in the ab plane. The layers have a zigzag topology, have the coordinating and non-coordinating benzyl-amine mol-ecules directed to the inside, and present the essentially flat PC resides to the outside. This arrangement enables adjacent layers to associate via π-π inter-actions [inter-centroid distance between pyrrolyl and fused-benzene rings = 3.593 (2) Å] so that a three-dimensional architecture is formed.

Synthesis and odor evaluation of five new sulfur-containing ester flavor compounds from 4-ethyloctanoic acid.

PubMed

Liu, Yuping; Chen, Haitao; Yin, Decai; Sun, Baoguo

2010-07-29

Five sulfur-containing flavor compounds were synthesized for the first time by the reaction of 4-ethyloctanoyl chloride with sulfur-containing alcohols or mercaptans. The synthesized compounds are 3-(methylthio)propyl 4-ethyloctanoate, 2-methyl-3-tetrahydro-furanthiol 4-ethyloctanoate, 4-methyl-5-thiazoleethanol 4-ethyloctanoate, 2-furan-methanethiol 4-ethyloctanoate and 2-methyl-3-furanthiol 4-ethyloctanoate. These five synthetic sulfur-containing ester flavor compounds all have meaty odor and might be used in foods if approved for this purpose in the future.

The thermal decomposition of the benzyl radical in a heated micro-reactor. II. Pyrolysis of the tropyl radical

DOE PAGES

Buckingham, Grant T.; Porterfield, Jessica P.; Kostko, Oleg; ...

2016-07-05

Cycloheptatrienyl (tropyl) radical, C 7H 7, was cleanly produced in the gas-phase, entrained in He or Ne carrier gas, and subjected to a set of flash-pyrolysis micro-reactors. In this study, the pyrolysis products resulting from C 7H 7 were detected and identified by vacuum ultraviolet photoionization mass spectrometry. Complementary product identification was provided by infrared absorption spectroscopy. Pyrolysis pressures in the micro-reactor were roughly 200 Torr and residence times were approximately 100 μs. Thermal cracking of tropyl radical begins at 1100 K and the products from pyrolysis of C 7H 7 are only acetylene and cyclopentadienyl radicals. Tropyl radicals domore » not isomerize to benzyl radicals at reactor temperatures up to 1600 K. Heating samples of either cycloheptatriene or norbornadiene never produced tropyl (C 7H 7) radicals but rather only benzyl (C 6H 5CH 2). The thermal decomposition of benzyl radicals has been reconsidered without participation of tropyl radicals. There are at least three distinct pathways for pyrolysis of benzyl radical: the Benson fragmentation, the methyl-phenyl radical, and the bridgehead norbornadienyl radical. These three pathways account for the majority of the products detected following pyrolysis of all of the isotopomers: C 6H 5CH 2, C 6H 5CD 2, C 6D 5CH 2, and C 6H 5 13CH 2. Finally, analysis of the temperature dependence for the pyrolysis of the isotopic species (C 6H 5CD 2, C 6D 5CH 2, and C 6H 5 13CH 2) suggests the Benson fragmentation and the norbornadienyl pathways open at reactor temperatures of 1300 K while the methyl-phenyl radical channel becomes active at slightly higher temperatures (1500 K).« less

The thermal decomposition of the benzyl radical in a heated micro-reactor. II. Pyrolysis of the tropyl radical

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

Buckingham, Grant T.; National Bioenergy Center, National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden Colorado 80401; Porterfield, Jessica P.

2016-07-07

Cycloheptatrienyl (tropyl) radical, C{sub 7}H{sub 7}, was cleanly produced in the gas-phase, entrained in He or Ne carrier gas, and subjected to a set of flash-pyrolysis micro-reactors. The pyrolysis products resulting from C{sub 7}H{sub 7} were detected and identified by vacuum ultraviolet photoionization mass spectrometry. Complementary product identification was provided by infrared absorption spectroscopy. Pyrolysis pressures in the micro-reactor were roughly 200 Torr and residence times were approximately 100 μs. Thermal cracking of tropyl radical begins at 1100 K and the products from pyrolysis of C{sub 7}H{sub 7} are only acetylene and cyclopentadienyl radicals. Tropyl radicals do not isomerize tomore » benzyl radicals at reactor temperatures up to 1600 K. Heating samples of either cycloheptatriene or norbornadiene never produced tropyl (C{sub 7}H{sub 7}) radicals but rather only benzyl (C{sub 6}H{sub 5}CH{sub 2}). The thermal decomposition of benzyl radicals has been reconsidered without participation of tropyl radicals. There are at least three distinct pathways for pyrolysis of benzyl radical: the Benson fragmentation, the methyl-phenyl radical, and the bridgehead norbornadienyl radical. These three pathways account for the majority of the products detected following pyrolysis of all of the isotopomers: C{sub 6}H{sub 5}CH{sub 2}, C{sub 6}H{sub 5}CD{sub 2}, C{sub 6}D{sub 5}CH{sub 2}, and C{sub 6}H{sub 5}{sup 13}CH{sub 2}. Analysis of the temperature dependence for the pyrolysis of the isotopic species (C{sub 6}H{sub 5}CD{sub 2}, C{sub 6}D{sub 5}CH{sub 2}, and C{sub 6}H{sub 5}{sup 13}CH{sub 2}) suggests the Benson fragmentation and the norbornadienyl pathways open at reactor temperatures of 1300 K while the methyl-phenyl radical channel becomes active at slightly higher temperatures (1500 K).« less

Homoleptic organolanthanide compounds supported by the bis(dimethylsilyl)benzyl ligand

DOE PAGES

Boteju, Kasuni C.; Ellern, Arkady; Sadow, Aaron D.

2016-12-19

Here, a β-SiH functionalized benzyl anion [C(SiHMe 2) 2Ph]$-$s obtained by deprotonation of HC(SiHMe 2) 2Ph with KCH 2Ph or by reaction of KOtBu and (Me 2HSi) 3CPh; LnI 3(THF)n and three equivalents of this carbanion combine to provide homoleptic tris(alkyl)lanthanide compounds Ln{C(SiHMe 2) 2Ph} 3 (Ln = La, Ce, Pr, Nd) containing secondary metal–ligand interactions.

Alkylation of pyridines at their 4-positions with styrenes plus yttrium reagent or benzyl Grignard reagents.

PubMed

Mizumori, Tomoya; Hata, Takeshi; Urabe, Hirokazu

2015-01-02

A new regioselective alkylation of pyridines at their 4-position was achieved with styrenes in the presence of yttrium trichloride, BuLi, and diisobutylaluminium hydride (DIBAL-H) in THF. Alternatively, similar products were more simply prepared from pyridines and benzyl Grignard reagents. These reactions are not only a useful preparation of 4-substituted pyridines but are also complementary to other relevant reactions usually giving 2-substituted pyridines. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Evaluation of Methods for the Analysis of Small Molecular Weight End-Products of Wastewater Ozonation.

DTIC Science & Technology

1980-04-01

advantage over the benzyl bromide method, which easily detected acetic and formic acid levels as low as 0.25 mg/L. Recovery was quantitative, with a...inner diameter glass, packed with 10% OV-l on 80/100 mesh Chromosorb WHP ( Alltech Associates) Carrier: Nitrogen at 24 cc/minute Column temperature: 150°C...found to be effective for analysis of acetic and formic acids. There was no advantage to the use of pentafluorobenzyl bromide over benzyl bromide, even

Synthesis of methyl 2-O- and 3-O-alpha-D-talopyranosyl-alpha-D-mannopyranoside.

PubMed

Rana, S S; Matta, K L

1986-09-01

Methyl 3,4,6-tri-O-benzyl-2-O-[6-O-(tert-butyldiphenylsilyl)-alpha-D- mannopyranosyl]-alpha-D-mannopyranoside (2) was synthesized by treatment of methyl 3,4,6-tri-O-benzyl-2-O-alpha-D-mannopyranosyl-alpha-D-mannopyranoside with tert-butylchlorodiphenylsilane in the presence of imidazole. Isopropylidenation, followed by oxidation with pyridinium chlorochromate, and stereoselective reduction with sodium borohydride, converted 2 into methyl 3,4,6-tri-O-benzyl-2-O-[6-O-(tert-butyldiphenylsilyl)-2,3-O-isopro pylidene- alpha-D-talopyranosyl]-alpha-D-mannopyranoside (5). Treatment of 5 with a molar solution of tetrabutylammonium fluoride in dry oxolane produced a diol which, on O-de-isopropylidenation followed by catalytic hydrogenolysis, afforded the disaccharide glycoside methyl 2-O-alpha-D-talopyranosyl-alpha-D-mannopyranoside. Synthesis of methyl 3-O-alpha-D-talopyranosyl-alpha-D-mannopyranoside was accomplished by a similar reaction-sequence. The structures of the final disaccharides, and of various other intermediates, were established by 1H- and 13C-n.m.r. spectroscopy.

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.

Local Order-Disorder Transition Driving by Structural Heterogeneity in a Benzyl Functionalized Ionic Liquid.

PubMed

Faria, Luiz F O; Paschoal, Vitor H; Lima, Thamires A; Ferreira, Fabio F; Freitas, Rafael S; Ribeiro, Mauro C C

2017-10-26

A local order-disorder transition has been disclosed in the thermophysical behavior of the ionic liquid 1-benzyl-3-methylimidazolium dicyanamide, [Bzmim][N(CN) 2 ], and its microscopic nature revealed by spectroscopic techniques. Differential scanning calorimetry and specific heat measurements show a thermal event of small enthalpy variation taking place in the range 250-260 K, which is not due to crystallization or melting. Molecular dynamic simulations and X-ray diffraction measurements have been used to discuss the segregation of domains in the liquid structure of [Bzmim][N(CN) 2 ]. Raman and NMR spectroscopy measurements as a function of temperature indicate that the microscopic origin of the event observed in the calorimetric measurements comes from structural rearrangement involving the benzyl group. The results indicate that the characteristic structural heterogeneity allow for rearrangements within local domains implying the good glass-forming ability for the low viscosity ionic liquid [Bzmim][N(CN) 2 ]. This work sheds light on our understanding of the microscopic origin behind complex thermal behavior of ionic liquids.

Hydrophobic benzyl amines as supports for liquid-phase C-terminal amidated peptide synthesis: application to the preparation of ABT-510.

PubMed

Matsumoto, Emiko; Fujita, Yuko; Okada, Yohei; Kauppinen, Esko I; Kamiya, Hidehiro; Chiba, Kazuhiro

2015-09-01

C-terminal amidation is one of the most common modification of peptides and frequently found in bioactive peptides. However, the C-terminal modification must be creative, because current chemical synthetic techniques of peptides are dominated by the use of C-terminal protecting supports. Therefore, it must be carried out after the removal of such supports, complicating reaction work-up and product isolation. In this context, hydrophobic benzyl amines were successfully added to the growing toolbox of soluble tag-assisted liquid-phase peptide synthesis as supports, leading to the total synthesis of ABT-510 (2). Although an ethyl amide-forming type was used in the present work, different types of hydrophobic benzyl amines could also be simply designed and prepared through versatile reductive aminations in one step. The standard acidic treatment used in the final deprotection step for peptide synthesis gave the desired C-terminal secondary amidated peptide with no epimerization. Copyright © 2015 European Peptide Society and John Wiley & Sons, Ltd.

Volatile Constituents of Three Piper Species from Vietnam.

PubMed

Hieua, Le D; Hoic, Tran M; Thangda, Tran D; Ogunwande, Isiaka A

2015-11-01

The chemical compositions of the essential oils obtained by hydrodistillation of three Piper plants grown in Vietnam are reported. The analysis was achieved by means of gas chromatography with flame ionization detection (GC-FID) and gas chromatography coupled with mass spectrometry (GC-MS). The main constituents of the leaf oil of Piper majusculum Blume were β-caryophyllene (20.7%), germacrene D (18.6%) and β-elemene (11.3%). The quantitatively significant compounds of the volatile oils of P. harmandii C. DC were sabinene (leaves, 14.5%; stems, 16.2%), benzyl benzoate (leaves, 20.0%; stems, 29.40%) and benzyl salicylate (leaves, 14.1%; stems, 24.3%). Also, α-cadinol (17.0%) was identified in large proportion in the leaf oil. However, sabinene (leaves, 17.9%; stems, 13.5%), benzyl benzoate (leaves, 20.5%; stems, 32.5%) and β-eudesmol (leaves, 13.8%; stems, 8.4%) were the main constituents of P. brevicaule C. DC. This is the first report on the volatile constituents of both P. harmandii and P. brevicaule.

Separation and characterization of lignin from bio-ethanol production residue.

PubMed

Guo, Guowan; Li, Shujun; Wang, Lu; Ren, Shixue; Fang, Guizhen

2013-05-01

In order to develop an adequate method to separate lignin from bio-ethanol production residue, solvent extraction was conducted by using benzyl alcohol, dioxane and ethanol. Compared to the conventional alkali-solution and acid-isolation method, benzyl alcohol and dioxane extraction could reach higher lignin yield of 71.55% and 74.14% respectively. FTIR and XRD analysis results indicate that sodium hydroxide solution dissolved most of the lignin in the raw material. However, the low lignin yield by this method may be attributed to the products loss during the complex separation process. GPC and (1)H NMR results revealed that the dioxane-lignin had closer molecular weight with alkali-lignin, lower S/G ratio (0.22) and higher OHPh/OHAl ratio (0.45) with respect to benzyl alcohol-lignin. The results divulge that the lignin products separated from bio-ethanol production residue by dioxane extraction had fairly potential application with better chemical activity. Copyright © 2012 Elsevier Ltd. All rights reserved.

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

Repellent activity of essential oils and some of their individual constituents against Tribolium castaneum herbst.

PubMed

Caballero-Gallardo, Karina; Olivero-Verbel, Jesús; Stashenko, Elena E

2011-03-09

A tool for integrated pest management is the use of essential oils (EOs) and plant extracts. In this study, EOs from Tagetes lucida , Lepechinia betonicifolia , Lippia alba , Cananga odorata , and Rosmarinus officinalis , species grown in Colombia, were analyzed by gas chromatography-mass spectrometry. These oils as well as several of their constituents were tested for repellent activity against Tribolium castaneum , using the area preference method. The main components (>10%) found in EOs were methylchavicol, limonene/α-pinene, carvone/limonene, benzyl acetate/linalool/benzyl benzoate, and α-pinene, for T. lucida, L. betonicifolia, L. alba, C. odorata, and R. officinalis, respectively. All EOs were repellent, followed a dose-response relationship, and had bioactivity similar to or better than that of commercial compound IR3535. EOs from C. odorata and L. alba were the most active. Compounds from EOs, such benzyl benzoate, β-myrcene, and carvone, showed good repellent properties. In short, EOs from plants cultivated in Colombia are sources of repellents against T. castaneum.

Compartmentalization Technologies via Self-Assembly and Cross-Linking of Amphiphilic Random Block Copolymers in Water.

PubMed

Matsumoto, Mayuko; Terashima, Takaya; Matsumoto, Kazuma; Takenaka, Mikihito; Sawamoto, Mitsuo

2017-05-31

Orthogonal self-assembly and intramolecular cross-linking of amphiphilic random block copolymers in water afforded an approach to tailor-make well-defined compartments and domains in single polymer chains and nanoaggregates. For a double compartment single-chain polymer, an amphiphilic random block copolymer bearing hydrophilic poly(ethylene glycol) (PEG) and hydrophobic dodecyl, benzyl, and olefin pendants was synthesized by living radical polymerization (LRP) and postfunctionalization; the dodecyl and benzyl units were incorporated into the different block segments, whereas PEG pendants were statistically attached along a chain. The copolymer self-folded via the orthogonal self-assembly of hydrophobic dodecyl and benzyl pendants in water, followed by intramolecular cross-linking, to form a single-chain polymer carrying double yet distinct hydrophobic nanocompartments. A single-chain cross-linked polymer with a chlorine terminal served as a globular macroinitiator for LRP to provide an amphiphilic tadpole macromolecule comprising a hydrophilic nanoparticle and a hydrophobic polymer tail; the tadpole thus self-assembled into multicompartment aggregates in water.

Effects of mix ratio, moisture content and aeration rate on sulfur odor emissions during pig manure composting.

PubMed

Zang, Bing; Li, Shuyan; Michel, Frederick; Li, Guoxue; Luo, Yuan; Zhang, Difang; Li, Yangyang

2016-10-01

Sulfur compounds in swine manure can cause odor emissions during composting if conditions are not conducive to their rapid oxidation and degradation. In this study, the effects of controllable composting process variables on sulfur odor emissions were investigated. These included pig manure to corn stalk mix ratio (0.7:1, 1.5:1 and 2.2:1dw basis), initial moisture content (60%, 65%, 70% and 75%) and aeration rate (1.0, 2.0, 3.0 and 4.0m(3)m(-3)h(-1)). The compounds measured were carbonyl sulfide, carbon disulfide, hydrogen sulfide, methyl mercaptan, ethyl mercaptan, diethyl sulfide, dimethyl sulfide (Me2S) and dimethyl disulfide (Me2SS). The results showed that total sulfur losses ranged from 3.9% to 18.3% after 26days of composting. Me2S and Me2SS were the primary (>59.61%) sulfur compounds released during this period. After turning, emission rates of both Me2S and Me2SS increased. Emissions of the other six sulfur compounds were low and inconsistent during composting. Within the compost, feedstock mix ratio significantly influenced the concentration of Me2SS, while aeration rate significantly affected Me2S concentration (p<0.05). Moisture content did not have a significant effect on the concentrations of either of these two compounds. Concentrations of sulfur odor compounds were the lowest at the highest aeration rate. Therefore, high aeration rates during the thermophilic phase, especially after turning, are recommended to minimize sulfur odors produced during swine manure composting. Copyright © 2016 Elsevier Ltd. All rights reserved.

High-resolution Fourier transform synchrotron spectroscopy of the C-S stretching band of methyl mercaptan, CH332SH

NASA Astrophysics Data System (ADS)

Lees, R. M.; Xu, Li-Hong; Billinghurst, B. E.

2016-01-01

The C-S stretching fundamental band of 12CH332SH, the principal isotopologue of methyl mercaptan, has been investigated by Fourier transform infrared spectroscopy on the Far-Infrared beamline at the Canadian Light Source synchrotron. The band is centered around 710 cm-1 and shows well-resolved a-type parallel structure. Most of the A and E spectral sub-bands have been assigned up to K = 12 for the vt = 0 torsional state and K = 9 for the vt = 1 state, along with a smaller variety of sub-bands for vt = 2. C-S stretching energy term values have been determined employing known ground-state energies, and have been fitted to series expansions in powers of J(J + 1) to determine the substate origins. The origins have in turn been fitted to a Fourier model to characterize the oscillatory torsional energy structure of the C-S stretching state. The amplitude of oscillation of the vt = 0 torsional curves is significantly larger for the C-S stretch state compared to the ground state. A strategy devised to relate this amplitude to an effective torsional barrier height indicates a decrease of about 7% in the effective V3 for the C-S stretch. The vibrational frequency determined for the stretching fundamental from the Fourier fit is 710.3 cm-1. The C-S stretching manifold is crossed by excited vt = 4 torsional levels of the ground state, and strong torsion-vibrational resonant coupling is observed via perturbations in the spectrum together with forbidden sub-bands induced by mixing and intensity borrowing.

Crystal structures of 3,5-bis-[(E)-3-hy-droxy-benzyl-idene]-1-methyl-piperidin-4-one and 3,5-bis-[(E)-2-chloro-benzyl-idene]-1-methyl-piperidin-4-one.

PubMed

Eryanti, Yum; Zamri, Adel; Herlina, Tati; Supratman, Unang; Rosli, Mohd Mustaqim; Fun, Hoong-Kun

2015-12-01

The title compounds, C20H19NO3, (1), and C20H17Cl2NO, (2), are the 3-hy-droxy-benzyl-idene and 2-chloro-benzyl-idene derivatives, respectively, of curcumin [systematic name: (1E,6E)-1,7-bis-(4-hy-droxy-3-meth-oxy-phen-yl)-1,6-hepta-diene-3,5-dione]. The dihedral angles between the benzene rings in each compound are 21.07 (6)° for (1) and 13.4 (3)° for (2). In both compounds, the piperidinone rings adopt a sofa confirmation and the methyl group attached to the N atom is in an equatorial position. In the crystal of (1), two pairs of O-H⋯N and O-H⋯O hydrogen bonds link the mol-ecules, forming chains along [10-1]. The chains are linked via C-H⋯O hydrogen bonds, forming undulating sheets parallel to the ac plane. In the crystal of (2), mol-ecules are linked by weak C-H⋯Cl hydrogen bonds, forming chains along the [204] direction. The chains are linked along the a-axis direction by π-π inter-actions [inter-centroid distance = 3.779 (4) Å]. For compound (2), the crystal studied was a non-merohedral twin with the refined ratio of the twin components being 0.116 (6):0.886 (6).

Mechanisms of catalytic cleavage of benzyl phenyl ether in aqueous and apolar phases

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

He, Jiayue; Lu, Lu; Zhao, Chen

2014-03-01

Catalytic pathways for the cleavage of ether bonds in benzyl phenyl ether (BPE) in liquid phase using Ni- and zeolite-based catalysts are explored. In the absence of catalysts, the C-O bond is selectively cleaved in water by hydrolysis, forming phenol and benzyl alcohol as intermediates, followed by alkylation. The hydronium ions catalyzing the reactions are provided by the dissociation of water at 523 K. Upon addition of HZSM-5, rates of hydrolysis and alkylation are markedly increased in relation to proton concentrations. In the presence of Ni/SiO 2, the selective hydrogenolysis dominates for cleaving the C aliphatic-O bond. Catalyzed by themore » dual-functional Ni/HZSM-5, hydrogenolysis occurs as the major route rather than hydrolysis (minor route). In apolar undecane, the non-catalytic thermal pyrolysis route dominates. Hydrogenolysis of BPE appears to be the major reaction pathway in undecane in the presence of Ni/SiO 2 or Ni/HZSM-5, almost completely suppressing radical reactions. Density functional theory (DFT) calculations strongly support the proposed C-O bond cleavage mechanisms on BPE in aqueous and apolar phases. These calculations show that BPE is initially protonated and subsequently hydrolyzed in the aqueous phase. Finally, DFT calculations suggest that the radical reactions in non-polar solvents lead to primary benzyl and phenoxy radicals in undecane, which leads to heavier condensation products as long as metals are absent for providing dissociated hydrogen.« less

Comparative Evaluation of Using NOTA and DOTA Derivatives as Bifunctional Chelating Agents in the Preparation of 68Ga-Labeled Porphyrin: Impact on Pharmacokinetics and Tumor Uptake in a Mouse Model.

PubMed

Guleria, Mohini; Das, Tapas; Amirdhanayagam, Jeyachitra; Sarma, Haladhar D; Dash, Ashutosh

2018-02-01

Both NOTA (1,4,7-triazacyclononane-1,4,7-triacetic acid) and DOTA (1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid) derivatives have been used as bifunctional chelating agents (BFCAs) for the preparation of 68 Ga-labeled target-specific agents having potential for positron emission tomography (PET) imaging of cancerous lesions. In the present work, the authors have attempted a comparative pharmacokinetic evaluation between 68 Ga-labeled porphyrins prepared using NOTA and DOTA derivatives as the BFCAs. A symmetrical porphyrin derivative, 5,10,15,20-tetrakis(p-carboxymethyleneoxyphenyl)porphyrin, was synthesized and coupled with two different BFCAs viz. p-NH 2 -benzyl-NOTA and p-NH 2 -benzyl-DOTA. Both the porphyrin-BFCA conjugates were radiolabeled with 68 Ga. A comparative bioevaluation involving pharmacokinetics and tumor affinity was performed in a tumor-bearing small animal model. Gallium-68-labeled porphyrin-amido-benzyl-NOTA and porphyrin-amido-benzyl-DOTA complexes were prepared with high radiochemical purity. Both radiolabeled complexes exhibited almost similar stability in human serum and near-identical tumor affinity and pharmacokinetic behavior in animal studies. The present study demonstrates that the pharmacokinetic behavior of 68 Ga-labeled porphyrin derivatives, prepared using either NOTA or DOTA derivatives as BFCAs, remains almost identical and hence both NOTA and DOTA derivatives could be considered equivalent for developing 68 Ga-based PET agents for imaging of tumorous lesions.

High-performance liquid chromatographic method for the simultaneous determination of 24 fragrance allergens to study scented products.

PubMed

Villa, C; Gambaro, R; Mariani, E; Dorato, S

2007-07-27

The European legislation on cosmetic products has recently required the declaration of 26 compounds (24 volatile chemicals and 2 natural extracts) on the label of final products when exceeding a stipulated cut-off level. In this work a rapid reliable and specific RP-HPLC method coupled with diode array detector (DAD) has been developed for the simultaneous determination and quantification of the 24 volatile chemicals: amyl cinnamal, benzyl alcohol, cinnamyl alcohol, citral, eugenol, hydroxy-citronellal, isoeugenol, amylcinnamyl alcohol, benzyl salicylate, cinnamal, coumarin, geraniol, Lyral (hydroxy-methylpentylcyclohexene carboxaldehyde), anisyl alcohol, benzyl cinnamate, farnesol, Lilial (2-(4-tert-butylbenzyl)propionaldehyde) linalool, benzyl benzoate, citronellol, hexyl cinnamal, limonene, methylheptin carbonate, alpha-isomethyl ionone (3-methyl-4-(2,6,6-trimethyl-2-cyclohexen-1-yl)-3-buten-2-one). The 24 analytes were appropriately separated over a running time of 40 min, on a C18 column using a simple gradient elution (acetonitrile/water) with flow rate from 0.7 to 1.0 ml/min and UV acquisition at 210, 254 and 280 nm. All calibration curves showed good linearity (r2>0.99) within test ranges. The method was successfully applied to the qualitative and quantitative determination of the potential allergens in four commercial scented products, with satisfactory accuracy and precision. The results indicated that this simple and efficient method can be used for quality assessment of complex matrices such us cosmetic scented products.

Efficient formation of benzylic quaternary centers via palladium catalysis.

PubMed

Gottumukkala, Aditya L; Suljagic, Jasmin; Matcha, Kiran; de Vries, Johannes G; Minnaard, Adriaan J

2013-09-01

Four's a crowd: An efficient protocol for the formation of benzylic quaternary centers via arylation of enones using a catalyst made from Pd(O2 CCF3 )2 and 2,2'-bipyridine is developed. For cyclic substrates, catalyst loadings as low as 1 mol % Pd are enough to afford excellent yields (>90%) using a variety of arylboronic acids. In case of acyclic substrates, the addition of KSbF6 was found to improve conversions and yields. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Synthesis and conformational studies of carrabiose and its 4'-sulphate and 2,4'-disulphate.

PubMed

Parra, E; Caro, H N; Jiménez-Barbero, J; Martín-Lomas, M; Bernabé, M

1990-12-15

Methyl alpha-carrabioside (13), and its 4-sulphate (19) and 2,4-disulphate (20) have been synthesised via glycosylation of methyl 3,6-anhydro-2-O-benzyl-alpha-D-galactopyranoside with 2,3,6-tri-O-acetyl-4-O-benzyl-beta-D-galactopyranosyl bromide and subsequent partial or complete debenzylation, sulphation, and deprotection of the resulting disaccharide derivatives. Conformational studies have been carried out on 13, 19, and 20 on the basis of 1D and 2D 1H-n.m.r. spectroscopy and molecular mechanics calculations.

Synthesis of modified proanthocyanidins: introduction of acyl substituents at C-8 of catechin. Selective synthesis of a C-4-->O-->C-3 ether-linked procyanidin-like dimer.

PubMed

Beauhaire, Josiane; Es-Safi, Nour-Eddine; Boyer, François-Didier; Kerhoas, Lucien; Guernevé, Christine le; Ducrot, Paul-Henri

2005-02-01

The regioselective introduction of substituents at C-8 of (+)-catechin is described, leading to the synthesis of several catechin derivatives with various substitution patterns to be used for the further synthesis of modified proanthocyanidins. Thereafter, a new 3-O-4 ether-linked procyanidin-like derivative was synthesized. Its formation was selectively achieved through TiCl(4)-catalyzed condensation of 4-(2-hydroxyethoxy)tetra-O-benzyl catechin with the 8-trifluoroacetyl adduct of tetra-O-benzyl catechin.

Intramolecular addition of benzylic radicals onto ketenimines. Synthesis of 2-alkylindoles.

PubMed

Alajarín, Mateo; Vidal, Angel; Ortín, María-Mar

2003-12-07

The inter- and intramolecular addition of free radicals onto ketenimines is studied. All the attempts to add intermolecularly several silicon, oxygen or carbon centered radicals to N-(4-methylphenyl)-C,C-diphenyl ketenimine were unsuccessful. In contrast, the intramolecular addition of benzylic radicals, generated from xanthates, onto the central carbon of a ketenimine function with its N atom linked to the ortho position of the aromatic ring occurred under a variety of reaction conditions. These intramolecular cyclizations provide a novel radical-mediated synthesis of 2-alkylindoles.

Simultaneous phase and morphology controllable synthesis of copper selenide films by microwave-assisted nonaqueous approach

NASA Astrophysics Data System (ADS)

Li, Jing; Fa, Wenjun; Li, Yasi; Zhao, Hongxiao; Gao, Yuanhao; Zheng, Zhi

2013-02-01

Copper selenide films with different phase and morphology were synthesized on copper substrate through controlling reaction solvent by microwave-assisted nonaqueous approach. The films were characterized by X-ray diffraction (XRD) and scanning electron microscope (SEM). The result showed that the pure films could be obtained using cyclohexyl alcohol or benzyl alcohol as solvent. The cubic Cu2-xSe dendrites were synthesized in cyclohexyl alcohol reaction system and hexagonal CuSe flaky crystals were obtained with benzyl alcohol as solvent.

Solvent-free catalytic dehydrative etherification of benzyl alcohol over graphene oxide

NASA Astrophysics Data System (ADS)

Yu, Huiyou; Wang, Xinde; Zhu, Yuanshuai; Zhuang, Guilin; Zhong, Xing; Wang, Jian-guo

2013-09-01

Graphene oxide (GO), prepared from oxidation of graphite powders using a modified Hummers method, exhibits a promising catalytic activity and a high selectivity for the solvent-free catalytic dehydrative etherification of benzyl alcohol (BA). A maximum yield (85.4%) of dibenzyl ether (DE) was achieved at 150 °C for 24 h when the BA/GO ration was 20 ml/g under solvent-free condition. This discovery provided a new insight into the development of GO as a carbocatalysts for a variety of applications in carbocatalysis.

Temperature Dependence of Positron Annihilation in beta-Cyclodextrin and beta-Cyclodextrin Complexes

NASA Astrophysics Data System (ADS)

Hu, Y.; Hsu Hadley, F. H., Jr.; Trinh, T.

1996-11-01

The effects of temperature on positron annihilation in beta-cyclodextrin and beta-cyclodextrin complexed with benzyl salicylate, benzyl acetate, ethyl salicylate, geraniol, linalool and nerol were studied. Samples were prepared by slurry, air-dried and freeze-dried methods. Lifetime spectra were measured as a function of temperature for each sample. Comparison of the annihilation rate and intensity of the longer-lived component showed that positronium formation was affected by guest molecules, preparation methods and temperature variations. Results can be used to explain beta-cyclodextrin complex formation with different guest molecules.

Cytotoxic saponins from Schefflera rotundifolia.

PubMed

Braca, Alessandra; Autore, Giuseppina; De Simone, Francesco; Marzocco, Stefania; Morelli, Ivano; Venturella, Fabio; De Tommasi, Nunziatina

2004-10-01

Eight new oleanane and lupane saponins (1-8) as well as two new benzyl glycosides (9 and 10) were isolated from the aerial parts of Schefflera rotundifolia (Ten) Frodin (Araliaceae) together with two known benzyl glycosides. Their structures were established using 1D- and 2D-NMR spectroscopy and mass spectrometry. The antiproliferative activity of all compounds was evaluated using three continuous murine and human culture cell lines J774.A1, HEK-293, and WEHI-164. Compounds 7 and 8, having betulinic acid as aglycone, were the most active constituents.

[1,5]-Anion relay via intramolecular proton transfer to generate 3,3-bis(silyl) allyloxy lithium: a useful scaffold for syn-addition to aldehydes and ketones.

PubMed

Lin, Xinglong; Ye, Xincui; Sun, Xianwei; Zhang, Yuebao; Gao, Lu; Song, Zhenlei

2014-02-21

A [1,5]-anion relay has been achieved in 3,3-bis(silyl) benzyl enol ether. Deprotonation at the sterically more accessible benzyl position triggers an intramolecular proton transfer to generate the thermodynamically more stable 3,3-bis(silyl) allyloxy lithium. This endo-oriented allyl anion is stable at -78 °C and undergoes diastereoselective syn-addition at the γ-position with aldehydes and ketones to give monobenzyl-substituted 1,2-diols.

Rigid Dipeptide Mimics: Synthesis of Enantiopure 5- and 7-Benzyl and 5,7-Dibenzyl Indolizidinone Amino Acids via Enolization and Alkylation of delta-Oxo alpha,omega-Di-[N-(9-(9-phenylfluorenyl))amino]azelate Esters.

PubMed

Polyak, Felix; Lubell, William D.

1998-08-21

Azabicyclo[X.Y.0]alkane amino acids are tools for constructing mimics of peptide structure and templates for generating combinatorial libraries for drug discovery. Our methodology for synthesizing these conformationally rigid dipeptides has been elaborated such that alkyl groups can be appended onto the heterocycle to generate mimics of peptide backbone and side-chain structure. Inexpensive glutamic acid was employed as chiral educt in a Claisen condensation/ketone alkylation/reductive amination/lactam cyclization sequence that furnished alkyl-branched azabicyclo[4.3.0]alkane amino acid. Enantiopure 5-benzyl-, 7-benzyl-, and 5,7-dibenzylindolizidinone amino acids 2-4 were stereoselectively synthesized via efficient reaction sequences featuring the alkylation of di-tert-butyl alpha,omega-di-[N-(PhF)amino]azelate delta-ketone 5. A variety of alkyl halides were readily added to the enolate of ketone 5 to provide mono- and dialkylated ketones 6 and 7. Hydride additions to 6 and 7, methanesulfonations, and intramolecular S(N)2 displacements by the PhF amine gave 5-alkylprolines that were converted by lactam cyclizations into 7- and 5-benzyl-, as well as 5,7-dibenzyl-2-oxo-3-N-(BOC)amino-1-azabicyclo[4.3.0]nonane-9-carboxylate methyl esters 10, 11, and 14. Epimerization of the alkyl-branched stereocenter via an iminium-enaminium equilibrium proved effective for controlling diastereoselectivity in reductive aminations with 6 and 7 in order to furnish 5-alkylprolines that were similarly converted to 7- benzyl- and 5,7-dibenzylindolizidinone N-(BOC)amino esters 10 and 14. Ester hydrolysis with hydroxide ion and potassium trimethylsilanolate then gave enantiopure indolizidinone amino acids 2-4. Epimerization at C-9 of benzylindolizidinone amino esters was also used to provide alternative diastereomers of 10, 11, and 14. This practical methodology for introducing side-chain groups onto the heterocycle with regioselective and diastereoselective control is designed to enhance the use of alkyl-branched azabicycloalkane amino acids for the exploration of conformation-activity relationships of various biologically active peptides.

Induction of thermotropic bicontinuous cubic phases in liquid-crystalline ammonium and phosphonium salts.

PubMed

Ichikawa, Takahiro; Yoshio, Masafumi; Hamasaki, Atsushi; Taguchi, Satomi; Liu, Feng; Zeng, Xiang-bing; Ungar, Goran; Ohno, Hiroyuki; Kato, Takashi

2012-02-08

Two series of wedge-shaped onium salts, one ammonium and the other phosphonium, having 3,4,5-tris(alkyloxy)benzyl moieties, exhibit thermotropic bicontinuous "gyroid" cubic (Cub(bi)) and hexagonal columnar liquid-crystalline (LC) phases by nanosegregation between ionophilic and ionophobic parts. The alkyl chain lengths on the cationic moieties, anion species, and alkyl chain lengths on the benzyl moieties have crucial effects on their thermotropic phase behavior. For example, triethyl-[3,4,5-tris(dodecyloxy)benzyl]ammonium hexafluorophosphate forms the thermotropic Ia3d Cub(bi) LC phase, whereas an analogous compound with trifluoromethanesulfonate anion shows no LC properties. Synchrotron small-angle diffraction intensities from the Ia3d Cub(bi) LC materials provide electron density maps in the bulk state. The resulting maps show convincingly that the Ia3d Cub(bi) structure is composed of three-dimensionally interconnected ion nanochannel networks surrounded by aliphatic domains. A novel differential mapping technique has been applied successfully. The map of triethyl-[3,4,5-tris(decyloxy)benzyl]ammonium tetrafluoroborate has been subtracted from that of the analogous ammonium salt with hexafluorophosphate anion in the Ia3d Cub(bi) phases. The differential map shows that the counteranions are located in the core of the three-dimensionally interconnected nanochannel networks. Changing from trimethyl- via triethyl- to tripropylammonium cation changes the phase from columnar to Cub(bi) to no mesophase, respectively. This sensitivity to the widened shape for the narrow end of the molecule is explained successfully by the previously proposed semiquantitative geometric model based on the radial distribution of volume in wedge-shaped molecules. The LC onium salts dissolve lithium tetrafluoroborate without losing the Ia3d Cub(bi) LC phase. The Cub(bi) LC materials exhibit efficient ion-transporting behavior as a result of their 3D interconnected ion nanochannel networks. The Ia3d Cub(bi) LC material formed by triethyl-[3,4,5-tris(decyloxy)benzyl]phosphonium tetrafluoroborate shows ionic conductivities higher than the analogous Ia3d Cub(bi) material based on ammonium salts. The present study indicates great potential of Cub(bi) LC nanostructures consisting of ionic molecules for development of transportation nanochannel materials.

Reduced 3,4'-bipyrazoles from a simple pyrazole precursor: synthetic sequence, molecular structures and supramolecular assembly.

PubMed

Cuartas, Viviana; Insuasty, Braulio; Cobo, Justo; Glidewell, Christopher

2017-10-01

The reaction of 5-chloro-3-methyl-1-phenyl-1H-pyrazole-4-carbaldehyde and N-benzylmethylamine under microwave irradiation gives 5-[benzyl(methyl)amino]-3-methyl-1-phenyl-1H-pyrazole-4-carbaldehyde, C 19 H 19 N 3 O, (I). Subsequent reactions under basic conditions, between (I) and a range of acetophenones, yield the corresponding chalcones. These undergo cyclocondensation reactions with hydrazine to produce reduced bipyrazoles which can be N-formylated with formic acid or N-acetylated with acetic anhydride. The structures of (I) and of representative examples from this reaction sequence are reported, namely the chalcone (E)-3-{5-[benzyl(methyl)amino]-3-methyl-1-phenyl-1H-pyrazol-4-yl}-1-(4-bromophenyl)prop-2-en-1-one, C 27 H 24 BrN 3 O, (II), the N-formyl derivative (3RS)-5'-[benzyl(methyl)amino]-3'-methyl-1',5-diphenyl-3,4-dihydro-1'H,2H-[3,4'-bipyrazole]-2-carbaldehyde, C 28 H 27 N 5 O, (III), and the N-acetyl derivative (3RS)-2-acetyl-5'-[benzyl(methyl)amino]-5-(4-methoxyphenyl)-3'-methyl-1'-phenyl-3,4-dihydro-1'H,2H-[3,4'-bipyrazole], which crystallizes as the ethanol 0.945-solvate, C 30 H 31 N 5 O 2 ·0.945C 2 H 6 O, (IV). There is significant delocalization of charge from the benzyl(methyl)amino substituent onto the carbonyl group in (I), but not in (II). In each of (III) and (IV), the reduced pyrazole ring is modestly puckered into an envelope conformation. The molecules of (I) are linked by a combination of C-H...N and C-H...π(arene) hydrogen bonds to form a simple chain of rings; those of (III) are linked by a combination of C-H...O and C-H...N hydrogen bonds to form sheets of R 2 2 (8) and R 6 6 (42) rings, and those of (IV) are linked by a combination of O-H...N and C-H...O hydrogen bonds to form a ribbon of edge-fused R 2 4 (16) and R 4 4 (24) rings.

Kinetic study of benzyl [1-14C]acetate as a potential probe for astrocytic energy metabolism in the rat brain: Comparison with benzyl [2-14C]acetate.

PubMed

Okada, Maki; Yanamoto, Kazuhiko; Kagawa, Tomohiko; Yoshino, Keiko; Hosoi, Rie; Abe, Kohji; Zhang, Ming-Rong; Inoue, Osamu

2016-02-01

Brain uptake of [(14)C]acetate has been reported to be a useful marker of astrocytic energy metabolism. In addition to uptake values, the rate of radiolabeled acetate washout from the brain appears to reflect CO2 exhaustion and oxygen consumption in astrocytes. We measured the time-radioactivity curves of benzyl [1-(14)C]acetate ([1-(14)C]BA), a lipophilic probe of [1-(14)C]acetate, and compared it with that of benzyl [2-(14)C]acetate ([2-(14)C]BA) in rat brains. The highest brain uptake was observed immediately after injecting either [1-(14)C]BA or [2-(14)C]BA, and both subsequently disappeared from the brain in a single-exponential manner. Estimated [1-(14)C]BA washout rates in the cerebral cortex and cerebellum were higher than those of [2-(14)C]BA. These results suggested that [1-(14)C]BA could be a useful probe for estimating the astrocytic oxidative metabolism. The [1-(14)C]BA washout rate in the cerebral cortex of immature rats was lower than that of mature rats. An autoradiographic study showed that the washout rates of [1-(14)C]BA from the rat brains of a lithium-pilocarpine-induced status epilepticus model were not significantly different from the values in control rat brains except for the medial septal nucleus. These results implied that the enhancement of amino acid turnover rate rather than astrocytic oxidative metabolism was increased in status epilepticus. © The Author(s) 2015.

A precursor to the beta-pyranosides of 3-amino-3,6-dideoxy-D-mannose (mycosamine).

PubMed

Alais, J; David, S

1992-06-04

SN2-type reaction of 3-O-(1-imidazyl)sulfonyl-1,2:5,6-di-O-isopropylidene-alpha-D-gluco furanose with benzoate gave the 3-O-benzoyl-alpha-D-allo derivative 2, which was hydrolysed to give the 5,6-diol 3. Compound 3 was converted into the 6-deoxy-6-iodo derivative 4 which was reduced with tributylstannane, and then position 5 was protected by benzyloxymethylation, to give 3-O-benzoyl-5-O-benzyloxymethyl-6-deoxy-1,2-O-isopropylidene-alpha -D- allofuranose (6). Debenzoylation of 6 gave 7, (1-imidazyl)sulfonylation gave 8, and azide displacement gave 3-azido-5-O-benzyloxymethyl-3,6-dideoxy- 1,2-O-isopropylidene-alpha-D-glucofuranose (9, 85%). Acetolysis of 9 gave 1,2,4-tri-O-acetyl-3-azido-3,6-dideoxy-alpha,beta-D-glucopyranose (10 and 11). Selective hydrolysis of AcO-1 in the mixture of 10 and 11 with hydrazine acetate (----12), followed by conversion into the pyranosyl chloride 13, treatment with N,N-dimethylformamide dimethyl acetal in the presence of tetrabutylammonium bromide, and benzylation gave 3-azido-4-O-benzyl-3,6-dideoxy-1,2-O-(1-methoxyethylidene)-alpha-D -glucopyranose (15). Treatment of 15 with dry acetic acid gave 1,2-di-O-acetyl-3-azido-4-O-benzyl-3,6-dideoxy-beta-D-glucopyranose (16, 86% yield) that was an excellent glycosyl donor in the presence of trimethylsilyl triflate, allowing the synthesis of cyclohexyl 2-O-acetyl-3-azido-4-O-benzyl-3,6-dideoxy-beta-D-glucopyranoside (17, 90%).(ABSTRACT TRUNCATED AT 250 WORDS)

Sensitization to 26 fragrances to be labelled according to current European regulation. Results of the IVDK and review of the literature.

PubMed

Schnuch, Axel; Uter, Wolfgang; Geier, Johannes; Lessmann, Holger; Frosch, Peter J

2007-07-01

To study the frequency of sensitization to 26 fragrances to be labelled according to current European regulation. During 4 periods of 6 months, from 1 January 2003 to 31 December 2004, 26 fragrances were patch tested additionally to the standard series in a total of 21 325 patients; the number of patients tested with each of the fragrances ranged from 1658 to 4238. Hydroxymethylpentylcyclohexene carboxaldehyde (HMPCC) was tested throughout all periods. The following frequencies of sensitization (rates in %, standardized for sex and age) were observed: tree moss (2.4%), HMPCC (2.3), oak moss (2.0), hydroxycitronellal (1.3), isoeugenol (1.1), cinnamic aldehyde (1.0), farnesol (0.9), cinnamic alcohol (0.6), citral (0.6), citronellol (0.5), geraniol (0.4), eugenol (0.4), coumarin (0.4), lilial (0.3), amyl-cinnamic alcohol (0.3), benzyl cinnamate (0.3), benzyl alcohol (0.3), linalool (0.2), methylheptin carbonate (0.2), amyl-cinnamic aldehyde (0.1), hexyl-cinnamic aldehyde (0.1), limonene (0.1), benzyl salicylate (0.1), gamma-methylionon (0.1), benzyl benzoate (0.0), anisyl alcohol (0.0). 1) Substances with higher sensitization frequencies were characterized by a considerable number of '++/+++' reactions. 2) Substances with low sensitization frequencies were characterized by a high number of doubtful/irritant and a low number of stronger (++/+++) reactions. 3) There are obviously fragrances among the 26 which are, with regard to contact allergy, of great, others of minor, and some of no importance at all.

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.

Structures of almond hydroxynitrile lyase isoenzyme 5 provide a rationale for the lack of oxidoreductase activity in flavin dependent HNLs.

PubMed

Pavkov-Keller, Tea; Bakhuis, Janny; Steinkellner, Georg; Jolink, Fenneke; Keijmel, Esther; Birner-Gruenberger, Ruth; Gruber, Karl

2016-10-10

Hydroxynitrile lyases (HNLs) catalyze the asymmetric addition of HCN to aldehydes producing enantiomerically pure cyanohydrins. These enzymes can be heterologously expressed in large quantities making them interesting candidates for industrial applications. The HNLs from Rosaceae evolved from flavin dependent dehydrogenase/oxidase structures. Here we report the high resolution X-ray structure of the highly glycosylated Prunus amygdalus HNL isoenzyme5 (PaHNL5 V317A) expressed in Aspergillus niger and its complex with benzyl alcohol. A comparison with the structure of isoenzyme PaHNL1 indicates a higher accessibility to the active site and a larger cavity for PaHNL5. Additionally, the PaHNL5 complex structure with benzyl alcohol was compared with the structurally related aryl-alcohol oxidase (AAO). Even though both enzymes contain an FAD-cofactor and histidine residues at crucial positions in the active site, PaHNL5 lacks the oxidoreductase activity. The structures indicate that in PaHNLs benzyl alcohol is bound too far away from the FAD cofactor in order to be oxidized. Copyright © 2016 Elsevier B.V. All rights reserved.

Syntheses of the enantiomers of 1-deoxynojirimycin and 1-deoxyaltronojirimycin via chemo- and diastereoselective olefinic oxidation of unsaturated amines.

PubMed

Bagal, Sharan K; Davies, Stephen G; Lee, James A; Roberts, Paul M; Scott, Philip M; Thomson, James E

2010-12-03

Oxidation of enantiomerically pure (R)-N(1)-1'-(1''-naphthyl)ethyl-2,7-dihydro-1H-azepine with m-CPBA in the presence of HBF(4) and BnOH gave (3S,4R,5S,6S,1'R)-N(1)-1'-(1''-naphthyl)ethyl-3-hydroxy-4-benzyloxy-5,6-epoxyazepane as the major product and as a single diastereoisomer after chromatography. Elaboration of this highly functionalized intermediate via ring contraction to (2S,3R,4S,5S,1'R)-N(1)-benzyl-2-chloromethyl-3-benzyloxy-4,5-epoxypiperidine followed by regioselective epoxide ring opening, functional group manipulation, and deprotection gave (+)-1-deoxyaltronojirimycin. Alternatively, resolution of (RS,RS)-N(1)-benzyl-3-hydroxy-4-benzyloxy-2,3,4,7-tetrahydro-1H-azepine or (3RS,4SR,5RS,6RS)-N(1)-benzyl-3-hydroxy-4-benzyloxy-5,6-epoxyazepane by preparative chiral HPLC and subsequent elaboration allows access to the enantiomers of 1-deoxynojirimycin and 1-deoxyaltronojirimycin, respectively.

Stable, water extractable isothiocyanates from Moringa oleifera leaves attenuate inflammation in vitro.

PubMed

Waterman, Carrie; Cheng, Diana M; Rojas-Silva, Patricio; Poulev, Alexander; Dreifus, Julia; Lila, Mary Ann; Raskin, Ilya

2014-07-01

Moringa (Moringa oleifera Lam.) is an edible plant used as both a food and medicine throughout the tropics. A moringa concentrate (MC), made by extracting fresh leaves with water, utilized naturally occurring myrosinase to convert four moringa glucosinolates into moringa isothiocyanates. Optimum conditions maximizing MC yield, 4-[(α-L-rhamnosyloxy)benzyl]isothiocyanate, and 4-[(4'-O-acetyl-α-L-rhamnosyloxy)benzyl]isothiocyanate content were established (1:5 fresh leaf weight to water ratio at room temperature). The optimized MC contained 1.66% isothiocyanates and 3.82% total polyphenols. 4-[(4'-O-acetyl-α-L-rhamnosyloxy)benzyl]isothiocyanate exhibited 80% stability at 37°C for 30 days. MC, and both of the isothiocyanates described above significantly decreased gene expression and production of inflammatory markers in RAW macrophages. Specifically, both attenuated expression of iNOS and IL-1β and production of nitric oxide and TNFα at 1 and 5 μM. These results suggest a potential for stable and concentrated moringa isothiocyanates, delivered in MC as a food-grade product, to alleviate low-grade inflammation associated with chronic diseases. Copyright © 2014 Elsevier Ltd. All rights reserved.

Spectroscopy Identification of Benzyl-Type Radicals Generated by Corona Discharge of Precursors of Mixed Substituents

NASA Astrophysics Data System (ADS)

Yoon, Young Wook; Huh, Chang Soon; Lee, Sang Kuk

2012-06-01

We generated vibronically excited but jet-cooled benzyl-type radicals from corona discharge of precursor of mixed substituents using a technique of corona excited supersonic expansion coupled with a pinhole-type glass nozzle, from which the visible vibronic emission spectra were recorded with a long-path monochromator. The spectra exhibit the intensity variation of each species with discharging voltage, indicating the radical species generated in corona discharge is highly sensitive to excitation. From the analysis of the spectra, we found the Cl substituent is replaced in preference to the F substituent by the hydrogen atoms liberated from the dissociation of the C-H bond of the methyl group of the precursor, from which we proposed the possible mechanism for the elimination reaction of substituent in terms of the bond dissociation energy. Additionally, we obtained an accurate electronic energy in the D_1 → D_0 transition and the vibrational mode frequencies of newly detected benzyl-type radicals in the ground electronic state by comparison with those of ab initio calculations and the known spectroscopic data of precursors for the first time.

Cometabolic degradation of ethyl mercaptan by phenol-utilizing Ralstonia eutropha in suspended growth and gas-recycling trickle-bed reactor.

PubMed

Sedighi, Mahsa; Zamir, Seyed Morteza; Vahabzadeh, Farzaneh

2016-01-01

The degradability of ethyl mercaptan (EM), by phenol-utilizing cells of Ralstonia eutropha, in both suspended and immobilized culture systems, was investigated in the present study. Free-cells experiments conducted at EM concentrations ranging from 1.25 to 14.42 mg/l, showed almost complete removal of EM at concentrations below 10.08 mg/l, which is much higher than the maximum biodegradable EM concentration obtained in experiments that did not utilize phenol as the primary substrate, i.e. 2.5 mg/l. The first-order kinetic rate constant (kSKS) for EM biodegradation by the phenol-utilizing cells (1.7 l/g biomass/h) was about 10 times higher than by cells without phenol utilization. Immobilized-cells experiments performed in a gas recycling trickle-bed reactor packed with kissiris particles at EM concentrations ranging from 1.6 to 36.9 mg/l, showed complete removal at all tested concentrations in a much shorter time, compared with free cells. The first-order kinetic rate constant (rmaxKs) for EM utilization was 0.04 l/h for the immobilized system compared to 0.06 for the suspended-growth culture, due to external mass transfer diffusion. Diffusion limitation was decreased by increasing the recycling-liquid flow rate from 25 to 65 ml/min. The removed EM was almost completely mineralized according to TOC and sulfate measurements. Shut down and starvation experiments revealed that the reactor could effectively handle the starving conditions and was reliable for full-scale application. Copyright © 2015 Elsevier Ltd. All rights reserved.

Odor composition analysis and odor indicator selection during sewage sludge composting

PubMed Central

Zhu, Yan-li; Zheng, Guo-di; Gao, Ding; Chen, Tong-bin; Wu, Fang-kun; Niu, Ming-jie; Zou, Ke-hua

2016-01-01

ABSTRACT On the basis of total temperature increase, normal dehydration, and maturity, the odor compositions of surface and internal piles in a well-run sewage sludge compost plant were analyzed using gas chromatography–mass spectrometry with a liquid nitrogen cooling system and a portable odor detector. Approximately 80 types of substances were detected, including 2 volatile inorganic compounds, 4 sulfur organic compounds, 16 benzenes, 27 alkanes, 15 alkenes, and 19 halogenated compounds. Most pollutants were mainly produced in the mesophilic and pre-thermophilic periods. The sulfur volatile organic compounds contributed significantly to odor and should be controlled primarily. Treatment strategies should be based on the properties of sulfur organic compounds. Hydrogen sulfide, methyl mercaptan, dimethyl disulfide, dimethyl sulfide, ammonia, and carbon disulfide were selected as core indicators. Ammonia, hydrogen sulfide, carbon disulfide, dimethyl disulfide, methyl mercaptan, dimethylbenzene, phenylpropane, and isopentane were designated as concentration indicators. Benzene, m-xylene, p-xylene, dimethylbenzene, dichloromethane, toluene, chlorobenzene, trichloromethane, carbon tetrachloride, and ethylbenzene were selected as health indicators. According to the principle of odor pollution indicator selection, dimethyl disulfide was selected as an odor pollution indicator of sewage sludge composting. Monitoring dimethyl disulfide provides a highly scientific method for modeling and evaluating odor pollution from sewage sludge composting facilities. Implications: Composting is one of the most important methods for sewage sludge treatment and improving the low organic matter content of many agricultural soils. However, odors are inevitably produced during the composting process. Understanding the production and emission patterns of odors is important for odor control and treatment. Core indicators, concentration indicators, and health indicators provide an index system to odor evaluation. An odor pollution indicator provides theoretical support for further modelling and evaluating odor pollution from sewage sludge composting facilities. PMID:27192607

Odor composition analysis and odor indicator selection during sewage sludge composting.

PubMed

Zhu, Yan-Li; Zheng, Guo-di; Gao, Ding; Chen, Tong-Bin; Wu, Fang-Kun; Niu, Ming-Jie; Zou, Ke-Hua

2016-09-01

On the basis of total temperature increase, normal dehydration, and maturity, the odor compositions of surface and internal piles in a well-run sewage sludge compost plant were analyzed using gas chromatography-mass spectrometry with a liquid nitrogen cooling system and a portable odor detector. Approximately 80 types of substances were detected, including 2 volatile inorganic compounds, 4 sulfur organic compounds, 16 benzenes, 27 alkanes, 15 alkenes, and 19 halogenated compounds. Most pollutants were mainly produced in the mesophilic and pre-thermophilic periods. The sulfur volatile organic compounds contributed significantly to odor and should be controlled primarily. Treatment strategies should be based on the properties of sulfur organic compounds. Hydrogen sulfide, methyl mercaptan, dimethyl disulfide, dimethyl sulfide, ammonia, and carbon disulfide were selected as core indicators. Ammonia, hydrogen sulfide, carbon disulfide, dimethyl disulfide, methyl mercaptan, dimethylbenzene, phenylpropane, and isopentane were designated as concentration indicators. Benzene, m-xylene, p-xylene, dimethylbenzene, dichloromethane, toluene, chlorobenzene, trichloromethane, carbon tetrachloride, and ethylbenzene were selected as health indicators. According to the principle of odor pollution indicator selection, dimethyl disulfide was selected as an odor pollution indicator of sewage sludge composting. Monitoring dimethyl disulfide provides a highly scientific method for modeling and evaluating odor pollution from sewage sludge composting facilities. Composting is one of the most important methods for sewage sludge treatment and improving the low organic matter content of many agricultural soils. However, odors are inevitably produced during the composting process. Understanding the production and emission patterns of odors is important for odor control and treatment. Core indicators, concentration indicators, and health indicators provide an index system to odor evaluation. An odor pollution indicator provides theoretical support for further modelling and evaluating odor pollution from sewage sludge composting facilities.

Deodorization of Garlic Breath by Foods, and the Role of Polyphenol Oxidase and Phenolic Compounds.

PubMed

Mirondo, Rita; Barringer, Sheryl

2016-10-01

Garlic causes a strong garlic breath that may persist for almost a day. Therefore, it is important to study deodorization techniques for garlic breath. The volatiles responsible for garlic breath include diallyl disulfide, allyl mercaptan, allyl methyl disulfide, and allyl methyl sulfide. After eating garlic, water (control), raw, juiced or heated apple, raw or heated lettuce, raw or juiced mint leaves, or green tea were consumed immediately. The levels of the garlic volatiles on the breath were analyzed from 1 to 60 min by selected ion flow tube mass spectrometry (SIFT-MS). Garlic was also blended with water (control), polyphenol oxidase (PPO), rosemarinic acid, quercetin or catechin, and the volatiles in the headspace analyzed from 3 to 40 min by SIFT-MS. Raw apple, raw lettuce, and mint leaves significantly decreased all of the garlic breath volatiles in vivo. The proposed mechanism is enzymatic deodorization where volatiles react with phenolic compounds. Apple juice and mint juice also had a deodorizing effect on most of the garlic volatiles but were generally not as effective as the raw food, probably because the juice had enzymatic activity but the phenolic compounds had already polymerized. Both heated apple and heated lettuce produced a significant reduction of diallyl disulfide and allyl mercaptan. The presence of phenolic compounds that react with the volatile compounds even in the absence of enzymes is the most likely mechanism. Green tea had no deodorizing effect on the garlic volatile compounds. Rosmarinic acid, catechin, quercetin, and PPO significantly decreased all garlic breath volatiles in vitro. Rosmarinic acid was the most effective at deodorization. © 2016 Institute of Food Technologists®.

Structure of substituted 2-(phenoxy)benzimidazoles

NASA Astrophysics Data System (ADS)

Pavlova, I. S.; Pervova, I. G.; Lipunova, G. N.; Novikova, R. K.; Slepukhin, P. A.; Lipunov, I. N.

2013-03-01

The synthesis and X-ray diffraction study of 1-benzyl-2-[2-(5-ethyltetrazole-2-yl)-phenoxy]-1H-benzimidazole and 1-benzyl-2-[2-(5-ethyltetrazole-2-yl)-4-nitrophenoxy]-1H-benzimidazole single crystals have been performed. The oxidative splitting of an azo-hydrazone group of 1-(2-hydroxy-(5-nitro)phenyl)-3-ethyl-5-(benzylbenzimidazolyl)formazans, a break in the C2-N1 bond, the interaction of o-hydroxyl group of aryl fragment with oxygen, and the formation of new 2-(phenoxy)benzimidazoles are found to occur in the presence of perchlorate iron(III).

Dehydration and clearing of adult Drosophila for ultramicroscopy.

PubMed

Becker, Klaus; Jährling, Nina; Saghafi, Saiedeh; Dodt, Hans-Ulrich

2013-07-01

This protocol describes the preparation of adult flies for ultramicroscopy (UM), a powerful imaging technique that achieves precise and accurate three-dimensional (3D) reconstructions of intact macroscopic specimens with micrometer resolution. In UM, a specimen in the size range of ∼1-15 mm is illuminated perpendicular to the observation pathway by two thin counterpropagating sheets of laser light. Thus, specimens for UM need to be sufficiently transparent, which requires chemical clearing in most cases. In this protocol, Drosophila melanogaster adults are fixed, dehydrated in ethanol, and then cleared in a solution of benzyl alcohol and benzyl benzoate.

A tandem conjugate addition/cyclization protocol for the asymmetric synthesis of 2-aryl-4-aminotetrahydroquinoline-3-carboxylic acid derivatives.

PubMed

Davies, Stephen G; Mujtaba, Nadeam; Roberts, Paul M; Smith, Andrew D; Thomson, James E

2009-05-07

Condensation of tert-butyl (E)-3-(2'-aminophenyl)propenoate with a range of aromatic and heteroaromatic aldehydes gives the corresponding imines as single diastereoisomers (>98% de). Addition of lithium (R)-N-benzyl-N-(alpha-methylbenzyl)amide initiates a tandem conjugate addition/cyclization reaction to generate 2-aryl-4-aminotetrahydroquinoline-3-carboxylic acid derivatives in >98% de, >98% ee and high isolated yield. Hydrogenolysis of an N(1)-Boc protected derivative allows selective cleavage of the N-benzyl-N-alpha-methylbenzyl protecting groups without compromise of the diastereo- or enantiopurity.

Molecular structure studies of (1S,2S)-2-benzyl-2,3-dihydro-2-(1H-inden-2-yl)-1H-inden-1-ol

PubMed Central

Zhang, Tao; Paluch, Krzysztof; Scalabrino, Gaia; Frankish, Neil; Healy, Anne-Marie; Sheridan, Helen

2015-01-01

The single enantiomer (1S,2S)-2-benzyl-2,3-dihydro-2-(1H-inden-2-yl)-1H-inden-1-ol (2), has recently been synthesized and isolated from its corresponding diastereoisomer (1). The molecular and crystal structures of this novel compound have been fully analyzed. The relative and absolute configurations have been determined by using a combination of analytical tools including X-ray crystallography, X-ray Powder Diffraction (XRPD) analysis and Nuclear Magnetic Resonance (NMR) spectroscopy. PMID:25750458

Hydrodehalogenation of alkyl iodides with base-mediated hydrogenation and catalytic transfer hydrogenation: application to the asymmetric synthesis of N-protected α-methylamines.

PubMed

Mandal, Pijus K; Birtwistle, J Sanderson; McMurray, John S

2014-09-05

We report a very mild synthesis of N-protected α-methylamines from the corresponding amino acids. Carboxyl groups of amino acids are reduced to iodomethyl groups via hydroxymethyl intermediates. Reductive deiodination to methyl groups is achieved by hydrogenation or catalytic transfer hydrogenation under alkaline conditions. Basic hydrodehalogenation is selective for the iodomethyl group over hydrogenolysis-labile protecting groups, such as benzyloxycarbonyl, benzyl ester, benzyl ether, and 9-fluorenyloxymethyl, thus allowing the conversion of virtually any protected amino acid into the corresponding N-protected α-methylamine.

Hydrodehalogenation of Alkyl Iodides with Base-Mediated Hydrogenation and Catalytic Transfer Hydrogenation: Application to the Asymmetric Synthesis of N-Protected α-Methylamines

PubMed Central

2015-01-01

We report a very mild synthesis of N-protected α-methylamines from the corresponding amino acids. Carboxyl groups of amino acids are reduced to iodomethyl groups via hydroxymethyl intermediates. Reductive deiodination to methyl groups is achieved by hydrogenation or catalytic transfer hydrogenation under alkaline conditions. Basic hydrodehalogenation is selective for the iodomethyl group over hydrogenolysis-labile protecting groups, such as benzyloxycarbonyl, benzyl ester, benzyl ether, and 9-fluorenyloxymethyl, thus allowing the conversion of virtually any protected amino acid into the corresponding N-protected α-methylamine. PMID:25116734

In vitro activity of an ear rinse containing tromethamine, EDTA, benzyl alcohol and 0.1% ketoconazole on Malassezia organisms from dogs with otitis externa.

PubMed

Cole, Lynette K; Luu, Dao H; Rajala-Schultz, Paivi J; Meadows, Cheyney; Torres, Audrey H

2007-04-01

The purpose of this study was to evaluate the in vitro activity of an ear rinse containing tromethamine, EDTA, benzyl alcohol and 0.1% ketoconazole in purified water on Malassezia organisms from dogs with otitis externa. Malassezia organisms were collected from ear swab samples from the external ear canal of 19 dogs with otitis externa plus one control strain of Malassezia pachydermatis. Three test solutions were evaluated: ER (EDTA, tromethamine, benzyl alcohol), ER + keto (EDTA, tromethamine, benzyl alcohol, ketoconazole), and H2O (purified water). Ten-millilitre aliquots of each test solution was transferred into 20 tubes and inoculated with one of the isolates (1 tube per isolate: 19 clinical and 1 control strain). Samples were retrieved from each tube at five time points (0, 15, 30, 45 and 60 min), transferred to Petri dishes, mixed with Sabouraud dextrose agar supplemented with 0.5% Tween 80 and incubated. Following incubation, the plates were examined for growth and colonies counted as colony-forming units per millilitre. The data were analysed using a repeated measures analysis, with pair-wise comparisons of solution-time combinations. There was a significant reduction in Malassezia growth in ER + keto at all time points (P < 0.0001) compared to time zero. Neither ER nor H2O had any effect on the growth of Malassezia. ER + keto was significantly more effective in reducing Malassezia growth (P < 0.0001) at all time points compared to both ER and H2O. ER + keto may be useful in the treatment of Malassezia otitis externa. Future studies should be performed to evaluate the in vivo efficacy of ER + keto as treatment for otic infections caused by Malassezia.

Sequential one-pot addition of excess aryl-Grignard reagents and electrophiles to O-alkyl thioformates.

PubMed

Murai, Toshiaki; Morikawa, Kenta; Maruyama, Toshifumi

2013-09-23

The sequential addition of aromatic Grignard reagents to O-alkyl thioformates proceeded to completion within 30 s to give aryl benzylic sulfanes in good yields. This reaction may begin with the nucleophilic attack of the Grignard reagent onto the carbon atom of the O-alkyl thioformates, followed by the elimination of ROMgBr to generate aromatic thioaldehydes, which then react with a second molecule of the Grignard reagent at the sulfur atom to form arylsulfanyl benzylic Grignard reagents. To confirm the generation of aromatic thioaldehydes, the reaction between O-alkyl thioformates and phenyl Grignard reagent was carried out in the presence of cyclopentadiene. As a result, hetero-Diels-Alder adducts of the thioaldehyde and the diene were formed. The treatment of a mixture of the thioformate and phenyl Grignard reagent with iodine gave 1,2-bis(phenylsulfanyl)-1,2-diphenyl ethane as a product, which indicated the formation of arylsulfanyl benzylic Grignard reagents in the reaction mixture. When electrophiles were added to the Grignard reagents that were generated in situ, four-component coupling products, that is, O-alkyl thioformates, two molecules of Grignard reagents, and electrophiles, were obtained in moderate-to-good yields. The use of silyl chloride or allylic bromides gave the adducts within 5 min, whereas the reaction with benzylic halides required more than 30 min. The addition to carbonyl compounds was complete within 1 min and the use of lithium bromide as an additive enhanced the yields of the four-component coupling products. Finally, oxiranes and imines also participated in the coupling reaction. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Thermoreversible hydrogels based on triblock copolymers of poly(ethylene glycol) and carboxyl functionalized poly(ε-caprolactone): The effect of carboxyl group substitution on the transition temperature and biocompatibility in plasma.

PubMed

Safaei Nikouei, Nazila; Vakili, Mohammad Reza; Bahniuk, Markian S; Unsworth, Larry; Akbari, Ali; Wu, Jianping; Lavasanifar, Afsaneh

2015-01-01

In this study we report on the development, characterization and plasma protein interaction of novel thermoresponsive in situ hydrogels based on triblock copolymers of poly(ethylene glycol) (PEG) and poly(α-carboxyl-co-benzyl carboxylate)-ε-caprolactone (PCBCL) having two different degrees of carboxyl group substitution on the PCBCL block. Block copolymers were synthesized through ring-opening polymerization of α-benzyl carboxylate-ε-caprolactone by dihydroxy PEG, leading to the production of poly(α-benzyl carboxylate-ε-caprolactone)-PEG-poly(α-benzyl carboxylate-ε-caprolactone) (PBCL-PEG-PBCL). This was followed by partial debenzylation of PBCL blocks under controlled conditions, leading to the preparation of PCBCL-PEG-PCBCL triblock copolymers with 30 and 54mol.% carboxyl group substitution. Prepared PCBCL-PEG-PCBCL block copolymers have been shown to have a concentration-dependent sol to gel transition as a result of an increase in temperature above ∼29°C, as evidenced by the inverse flow method, differential scanning calorimetry and dynamic mechanical analysis. The sol-gel transition temperature/concentration and dynamic mechanical properties of the gel were found to be dependent on the level of carboxyl group substitution. Both hydrogels (30 and 54mol.% carboxyl group substitution) showed similar amounts of protein adsorption but striking differences in the profiles of the adsorbed proteome. Additionally, the two systems showed similarities in their clot formation kinetics but substantial differences in clot endpoints. The results show great promise for the above-mentioned thermoreversible in situ hydrogels as biocompatible materials for biomedical applications. Copyright © 2014 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Acaricidal activities of β-caryophyllene oxide and structural analogues derived from Psidium cattleianum oil against house dust mites.

PubMed

Oh, Min-Seok; Yang, Ji-Yeon; Kim, Min-Gi; Lee, Hoi-Seon

2014-05-01

This study was to evaluate the acaricidal activities of an active compound isolated from Psidium cattleianum and structural analogues against Dermatophagoides farinae and D. pteronyssinus. β-Caryophyllene oxide was isolated using chromatographic techniques. Based on the 50% lethal concentration (LD50) values against D. farinae using the fumigant method, β-caryophyllene oxide (1.36 µg cm(-2)) was ∼ 7.52 times more toxic than benzyl benzoate (10.23 µg cm(-2)), followed by α-caryophyllene (1.75 µg cm(-2)) and β-caryophyllene (3.13 µg cm(-2)). Against D. pteronyssinus, β-caryophyllene oxide (1.38 µg cm(-2)) was ∼ 7.22 times more toxic than benzyl benzoate (9.96 µg cm(-2)), followed by α-caryophyllene (1.71 µg cm(-2)) and β-caryophyllene (3.58 µg cm(-2)). In the contact toxicity method against D. farinae, β-caryophyllene oxide (0.44 µg cm(-2)) was ∼ 17.27 times more active than benzyl benzoate (7.60 µg cm(-2)), followed by α-caryophyllene (0.67 µg cm(-2)) and β-caryophyllene (0.91 µg cm(-2)). Against D. pteronyssinus, β-caryophyllene oxide (0.47 µg cm(-2)) was ∼ 13.06 times more effective than benzyl benzoate (6.14 µg cm(-2)), followed by α-caryophyllene (1.71 µg cm(-2)) and β-caryophyllene (3.58 µg cm(-2)). β-Caryophyllene oxide and structural analogues have potential for development as preventive agents for the control of house dust mites. © 2013 Society of Chemical Industry.

Photophysical properties of a new series of water soluble iridium bisterpyridine complexes functionalised at the 4' position.

PubMed

Goldstein, Daniel C; Cheng, Yuen Yap; Schmidt, Timothy W; Bhadbhade, Mohan; Thordarson, Pall

2011-03-07

Four new hetero- and homo-leptic iridium(III) bisterpyridine complexes have been prepared which incorporate aniline (tpy-φ-NH(2)), benzoic acid (tpy-φ-COOH), and benzyl alcohol (tpy-φ-CH(2)OH) substituents at the 4' positions of the tpy ligands (tpy = 2,2':6',2''-terpyridine, φ = phenylene). The electrochemical behaviour and ground and excited state spectroscopic properties of the complexes are reported, and the X-ray crystal structures of a homoleptic benzyl alcohol [Ir(tpy-φ-CH(2)OH)(2)](PF(6))(3), homoleptic aniline [Ir(tpy-φ-NH(2))(2)](PF(6))(3), and heteroleptic benzyl alcohol/aniline substituted complex [Ir(tpy-φ-CH(2)OH)(tpy-φ-NH(2))](PF(6))(3) have been solved. Complexes with aniline substituents were found to display absorption bands at around 430 nm corresponding to intraligand charge transfer (ILCT) that are sensitive to changes in solvent and pH. Strong emission in the visible region involving the ILCT state is observed in two of the complexes (Φ(e) = 0.7% and 2.6%) in acetonitrile. In the heteroleptic aniline/benzyl alcohol complex the Stokes shift is shown to be linearly related to solvent polarisability according to the Lippert equation, but only for solvents with weak hydrogen bonding interactions. Additionally, in water, emission from the ILCT state is quenched and only weak ligand centred (LC) emission is observed. The long lifetimes and quantum yields of these complexes make them interesting candidates for probes in sensing applications, especially [Ir(tpy-φ-CH(2)OH)(tpy-φ-NH(2))(2)](PF(6))(3) due to its unusual sensitivity to the solvent environment.

Recent trends in aviation turbine fuel properties

NASA Technical Reports Server (NTRS)

Friedman, R.

1982-01-01

Plots and tables, compiled from Department of Energy (and predecessor agency) inspection reports from 1969 to 1980, present ranges, averages, extremes, and trends for most of the 22 properties of Jet A aviation turbine fuel. In recent years, average values of aromatics content, mercaptan sulfur content, distillation temperature of 10 percent recovered, smoke point, and freezing point show small but recognizable trends toward their specification limits. About 80 percent of the fuel samples had at least one property near specification, defined as within a standard band about the specification limit. By far the most common near-specification properties were aromatics content, smoke point, and freezing point.

Laser light scattering from wood samples soaked in water or in benzyl benzoate

NASA Astrophysics Data System (ADS)

Simonaho, S.-P.; Tolonen, Y.; Rouvinen, J.; Silvennoinen, R.

Laser light scattering from Scots pine (Pinus Sylvesteris L.) wood samples soaked in two different liquids, which were tap water and benzyl benzoate, has been experimentally investigated. Differences in the characteristics of the scattering pattern as function of the soaking time as well as the moisture effect in the orientation of scattering pattern has been experimentally investigated. The wood samples soaked in the test liquids altered the laser light scattering in along and across the grain directions. No correlation between the content of the water in the wood sample and the orientation of laser light scattering pattern was observed.

3-O-Benzyl-6-O-benzoyl-1,2-O-isopropil-idene-5-C-nitro-methyl-a-d-glucofuran-ose.

PubMed

Pampín, Begoña; Valencia, Laura; Estévez, Juan C; Estévez, Ramón J

2009-01-17

The title compound, C(24)H(27)NO(9), is one of the epimers of the Henry reaction of 3-O-benzyl-6-O-benzoyl-2-O-isopropyl-idene-a-d-glucofuran-5-one with nitro-methane. The conformation of the five membered rings is as expected from the precursor compound and the mol-ecule is folded with a dihedral angle of 51.4 (2)° between the aromatic rings. One O-H⋯O hydrogen bond and some intra-molecular and inter-molecular C-H⋯O inter-actions are observed in the structure.

Silica functionalized Cu(II) acetylacetonate Schiff base complex: An efficient catalyst for the oxidative condensation reaction of benzyl alcohol with amines

NASA Astrophysics Data System (ADS)

Anbarasu, G.; Malathy, M.; Karthikeyan, P.; Rajavel, R.

2017-09-01

Silica functionalized Cu(II) acetylacetonate Schiff base complex via the one pot reaction of silica functionalized 3-aminopropyltriethoxysilane with acetyl acetone and copper acetate has been reported. The synthesized material was well characterized by analytical techniques such as FT-IR, UV-DRS, XRD, SEM-EDX, HR-TEM, EPR, ICP-AES and BET analysis. The characterization results confirmed the grafting of Cu(II) Schiff base complex on the silica surface. The catalytic activity of synthesized silica functionalized Cu(II) acetylacetonate Schiff base complex was evaluated through the oxidative condensation reaction of benzyl alcohol to imine.

Synthesis and anticonvulsant activities of N-benzyl (2R)-2-acetamido-3-oxysubstituted propionamide derivatives

PubMed Central

Morieux, Pierre; Stables, James P.; Kohn, Harold

2009-01-01

Lacosamide has been submitted for regulatory approval in the United States and Europe for the treatment of epilepsy. Previous synthetic methods did not permit the elaboration of the structure–activity relationship (SAR) for the 3-oxy site in lacosamide. We report an expedient five-step stereospecific synthesis for N-benzyl (2R)-2-acetamido-3-oxysubstituted propionamide analogs beginning with d-serine methyl ester. The procedure incorporated alkyl (e.g. methyl, primary, secondary, and tertiary) and aryl groups at this position. The SAR for the 3-oxy site showed maximal activity in animal seizure models for small 3-alkoxy substituents. PMID:18789868

X-ray and conformational investigations of a 4:1 mixture of 6-(N-benzyl-N-tert-butoxycarbonylamino)-2,3,6,7-tetradeoxy-alpha- DL-ery thro- and -beta-DL-threo-hept-2-enopyranos-4-uloses.

PubMed

Krajewski, J W; Urbańczyk-Lipkowska, Z; Gluziński, P; Jurczak, J; Raczko, J; Gołebiowski, A

1990-07-01

The crystals of a 4:1 mixture of 6-(N-benzyl-N-tert-butoxycarbonylamino)-2,3,6,7-tetradeoxy-a-DL-er ythro- and -beta-DL-threo-hept-2-enopyranos-4-ulose were monoclinic, space group P2(1)/c, with cell dimensions: a = 9.490(2), b = 21.516(5), c = 10.279(2) A, beta = 115.31(1) degrees, Z = 4. The ulose ring had a half-chair conformation deformed towards the sofa (envelope) form.

Short Enantioselective Total Synthesis of Tatanan A and 3‐epi‐Tatanan A Using Assembly‐Line Synthesis

PubMed Central

Noble, Adam; Roesner, Stefan

2016-01-01

Abstract Short and highly stereoselective total syntheses of the sesquilignan natural product tatanan A and its C3 epimer are described. An assembly‐line synthesis approach, using iterative lithiation–borylation reactions, was applied to install the three contiguous stereocenters with high enantio‐ and diastereoselectivity. One of the stereocenters was installed using a configurationally labile lithiated primary benzyl benzoate, resulting in high levels of substrate‐controlled (undesired) diastereoselectivity. However, reversal of selectivity was achieved by using a novel diastereoselective Matteson homologation. Stereospecific alkynylation of a hindered secondary benzylic boronic ester enabled completion of the synthesis in a total of eight steps. PMID:27865037

Active monoterpene ketones isolated from Rosmarinus officinalis with fumigant and contact action against Tyrophagus putrescentiae (Schrank).

PubMed

Jeon, Ju-Hyun; Park, Jun-Hwan; Chung, Namhyun; Lee, Hoi-Seon

2014-08-01

The acaricidal activities of an active material derived from Rosmarinus officinalis oil and its relative monoterpene ketones were determined using fumigant and contact toxicity bioassays against Tyrophagus putrescentiae and were compared with that of a commercial acaricide (benzyl benzoate). The active component of R. officinalis oil, isolated by silica gel column chromatography and high-performance liquid chromatography, was identified as camphor, based on various spectroscopic analyses. In the fumigant toxicity bioassay, camphor (2.25 μg/cm(3)) was 5.58 times more active than benzyl benzoate (12.56 μg/cm(3)) against T. putrescentiae, followed by (+)-camphor (3.89 μg/cm(3)) and (-)-camphor (5.61 μg/cm(3)). In the contact toxicity bioassay, camphor (1.34 μg/cm(2)) was 6.74 times more toxic than benzyl benzoate (9.03 μg/cm(2)) against T. putrescentiae, followed by (+)-camphor (2.23 μg/cm(2)) and (-)-camphor (2.94 μg/cm(2)). These results indicate that camphor and its derivatives are very useful as potential control agents against stored food mites regardless of the application method.

Antiproliferative effect of a novel nitro-oxy derivative of celecoxib in human colon cancer cells: role of COX-2 and nitric oxide.

PubMed

Bocca, Claudia; Bozzo, Francesca; Bassignana, Andrea; Miglietta, Antonella

2010-07-01

It has been shown previously that a novel nitrooxy derivative of celecoxib exerts antiproliferative and pro-apoptotic effects in human colon cancer cells. The aim of this study was to elucidate whether these biological properties depend on COX-2 inhibition and/or NO release. Therefore, the derivative was decomposed into the parent compound celecoxib and the NO donor benzyl nitrate and the biological role of each was tested in COX-2-positive (HT-29) and -negative (SW-480) colon cancer cells. The main findings were that the nitro-oxy derivative behaved like celecoxib in HT-29 cells in terms of COX-2 and ERK/MAPK inhibition, as well as induction of apoptosis, while the benzyl nitrate had no such effects. Interestingly, the beta-catenin system was activated by the nitro-oxy derivative as well as by benzyl nitrate alone more potently than by the parent compound celecoxib, suggesting a possible regulatory role for NO. In SW480 cells, these activities were substantially less pronounced, suggesting the presence of COX-2-dependent mechanisms in the modulation of these parameters.

The use of O-trifluoroacetyl protection and profound influence of the nature of glycosyl acceptor in benzyl-free arabinofuranosylation.

PubMed

Abronina, Polina I; Fedina, Ksenia G; Podvalnyy, Nikita M; Zinin, Alexander I; Chizhov, Alexander O; Kondakov, Nikolay N; Torgov, Vladimir I; Kononov, Leonid O

2014-09-19

The influence of O-trifluoroacetyl (TFA) groups at different positions of thioglycoside glycosyl donors on stereoselectivity of α-arabinofuranosylation leading to corresponding disaccharides was studied. It was shown that TFA group in thioglycoside glycosyl donors, when combined with 2-O-(triisopropylsilyl) (TIPS) non-participating group, may be regarded as an electron-withdrawing protecting group that may enhance 1,2-cis-selectivity in arabinofuranosylation, the results strongly depending on the nature of glycosyl acceptor. The reactivities of the glycosyl donors were compared with those of a similar thioglycoside with O-pentafluoropropionyl groups and the known phenyl 3,5-O-(di-tert-butylsilylene)-1-thio-α-d-arabinofuranosides with 2-O-TIPS and 2-O-benzyl groups. The 'matching' in the donor-acceptor combination was found to be critical for achieving both high reactivity of glycosyl donor and β-stereoselectivity of arabinofuranosylation. The use of glycosyl donors with TFA and silyl protection may be useful in the realization of the benzyl-free approach to oligoarabinofuranosides with azido group in aglycon-convenient building blocks for the preparation of neoglycoconjugates. Copyright © 2014 Elsevier Ltd. All rights reserved.

1-(substituted benzyl)-3,4,5,6-tetrahydro-2(1H)-pyrimidones: a series with stimulant and depressant activities.

PubMed

Ellis, K O; Schwan, T J; Wessels, F L; Miles, N J

1980-10-01

A series of 1-(substituted benzyl)-3,4,5,6-tetrahydro-2(1H)-pyrimidones was synthesized primarily by catalytic hydrogenation of the corresponding 1-(substituted benzyl)-2(1H)-pyrimidone. The pharmacological evaluation of these compounds in mice revealed a unique profile that included evidence of CNS stimulation and depression within the series and in the same compounds. Some members of this series induced signs of only CNS stimulation, some compounds caused signs of only CNS depression and skeletal muscle relaxation, and some caused signs of both stimulation and depression in the same animal. This apparent dual activity was assessed further in mice with antidepressant tests based on tetrabenazine antagonism and with antianxiety/anticonvulsant tests on the antagonism of a number of convulsants. The 4-chloro-, 4-fluoro-, 4-bromo-, and 3,4-dichlorobenzyl compounds exhibited antidepressant and antianxiety activities in the same dose range. Among these four compounds, the 3,4-dichlorobenzyl compound possessed the lowest antitetrabenazine (17 mg/kg po) and antipentylenetetrazol (23 mg/kg po) ED50 values. The 4-fluoro compound antagonized tetrabenazine-, pentylenetetrazol-, and isoniazid-induced tonic convulsions in the same dose range (congruent to 50 mg/kg po).

Benzyl and Methyl Fatty Hydroxamic Acids Based on Palm Kernel Oil as Chelating Agent for Liquid-Liquid Iron(III) Extraction

PubMed Central

Haron, Md Jelas; Jahangirian, Hossein; Silong, Sidik; Yusof, Nor Azah; Kassim, Anuar; Rafiee-Moghaddam, Roshanak; Mahdavi, Behnam; Peyda, Mazyar; Abdollahi, Yadollah; Amin, Jamileh

2012-01-01

Liquid-liquid iron(III) extraction was investigated using benzyl fatty hydroxamic acids (BFHAs) and methyl fatty hydroxamic acids (MFHAs) as chelating agents through the formation of iron(III) methyl fatty hydroxamate (Fe-MFHs) or iron(III) benzyl fatty hydroxamate (Fe-BFHs) in the organic phase. The results obtained under optimized conditions, showed that the chelating agents in hexane extract iron(III) at pH 1.9 were realized effectively with a high percentage of extraction (97.2% and 98.1% for MFHAs and BFHAs, respectively). The presence of a large amount of Mg(II), Ni(II), Al(III), Mn(II) and Co(II) ions did affect the iron(III) extraction. Finally stripping studies for recovering iron(III) from organic phase (Fe-MFHs or Fe-BFHs dissolved in hexane) were carried out at various concentrations of HCl, HNO3 and H2SO4. The results showed that the desired acid for recovery of iron(III) was 5 M HCl and quantitative recovery of iron(III) was achieved from Fe(III)-MFHs and Fe(III)-BFHs solutions in hexane containing 5 mg/L of Fe(III). PMID:22408444

Cobalt-catalyzed cross-coupling reactions of alkyl halides with allylic and benzylic Grignard reagents and their application to tandem radical cyclization/cross-coupling reactions.

PubMed

Ohmiya, Hirohisa; Tsuji, Takashi; Yorimitsu, Hideki; Oshima, Koichiro

2004-11-05

Details of cobalt-catalyzed cross-coupling reactions of alkyl halides with allylic Grignard reagents are disclosed. A combination of cobalt(II) chloride and 1,2-bis(diphenylphosphino)ethane (DPPE) or 1,3-bis(diphenylphosphino)propane (DPPP) is suitable as a precatalyst and allows secondary and tertiary alkyl halides--as well as primary ones--to be employed as coupling partners for allyl Grignard reagents. The reaction offers a facile synthesis of quaternary carbon centers, which has practically never been possible with palladium, nickel, and copper catalysts. Benzyl, methallyl, and crotyl Grignard reagents can all couple with alkyl halides. The benzylation definitely requires DPPE or DPPP as a ligand. The reaction mechanism should include the generation of an alkyl radical from the parent alkyl halide. The mechanism can be interpreted in terms of a tandem radical cyclization/cross-coupling reaction. In addition, serendipitous tandem radical cyclization/cyclopropanation/carbonyl allylation of 5-alkoxy-6-halo-4-oxa-1-hexene derivatives is also described. The intermediacy of a carbon-centered radical results in the loss of the original stereochemistry of the parent alkyl halides, creating the potential for asymmetric cross-coupling of racemic alkyl halides.

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

Identification of the Benzyloxyphenyl Pharmacophore: A Structural Unit That Promotes Sodium Channel Slow Inactivation

PubMed Central

2012-01-01

Four compounds that contained the N-benzyl 2-amino-3-methoxypropionamide unit were evaluated for their ability to modulate Na+ currents in catecholamine A differentiated CAD neuronal cells. The compounds differed by the absence or presence of either a terminal N-acetyl group or a (3-fluoro)benzyloxy moiety positioned at the 4′-benzylamide site. Analysis of whole-cell patch-clamp electrophysiology data showed that the incorporation of the (3-fluoro)benzyloxy unit, to give the (3-fluoro)benzyloxyphenyl pharmacophore, dramatically enhanced the magnitude of Na+ channel slow inactivation. In addition, N-acetylation markedly increased the stereoselectivity for Na+ channel slow inactivation. Furthermore, we observed that Na+ channel frequency (use)-dependent block was maintained upon inclusion of this pharmacophore. Confirmation of the importance of the (3-fluoro)benzyloxyphenyl pharmacophore was shown by examining compounds where the N-benzyl 2-amino-3-methoxypropionamide unit was replaced by a N-benzyl 2-amino-3-methylpropionamide moiety, as well as examining a series of compounds that did not contain an amino acid group but retained the pharmacophore unit. Collectively, the data indicated that the (3-fluoro)benzyloxyphenyl unit is a novel pharmacophore for the modulation of Na+ currents. PMID:23259039

Antitrypanosomal isothiocyanate and thiocarbamate glycosides from Moringa peregrina.

PubMed

Ayyari, Mahdi; Salehi, Peyman; Ebrahimi, Samad Nejad; Zimmermann, Stefanie; Portmann, Lena; Krauth-Siegel, R Luise; Kaiser, Marcel; Brun, Reto; Rezadoost, Hassan; Rezazadeh, Shamsali; Hamburger, Matthias

2014-01-01

O-Methyl (1), O-ethyl (2), and O-butyl (3) 4-[(α-L-rhamnosyloxy) benzyl] thiocarbamate (E), along with 4-(α-L-rhamnosyloxy) benzyl isothiocyanate (4) have been isolated from the aerial parts of Moringa peregrina. The compounds were tested for in vitro activity against Trypanosoma brucei rhodesiense and cytotoxicity in rat skeletal myoblasts (L6 cells). The most potent compound was 4 with an IC50 of 0.10 µM against T.b. rhodesiense and a selectivity index of 73, while the thiocarbamate glycosides 1, 2, and 3 showed only moderate activity. Intraperitoneal administration of 50 mg/kg body weight/day of 4 in the T.b. rhodesiense STIB 900 acute mouse model revealed significant in vivo toxicity. Administration of 10 mg/kg body weight/day resulted in a 95% reduction of parasitemia on day 7 postinfection, but did not cure the animals. Because of its high in vitro activity and its ability to irreversibly inhibit trypanothione reductase, an attractive parasite-specific target enzyme, 4-[(α-L-rhamnosyloxy) benzyl] isothiocyanate (4), can be considered as a lead structure for the development and characterization of novel antitrypanosomal drugs. Georg Thieme Verlag KG Stuttgart · New York.

Synthesis, structure, photoluminescence and antitumour activity of zinc complex based on 2-(2-(1H-benzo-[d]imidazol-2-yl)benzyl)-1H-benzo-[d]imidazole

NASA Astrophysics Data System (ADS)

Che, Zhijian; Wang, Shaoxiang; Liu, Shenggui; Li, Guobi; Wu, Qiting; Lin, Chunyu; Kong, Linglang; Wang, Sheng

2015-01-01

A new complex [Zn(bbb)Cl2]·DMF, where bbb is 2-(2-(1H-benzo[d]imidazol-2-yl)benzyl)-1H-benzo[d]imidazole, was synthesized and characterized by element analysis, 1H NMR and X-ray single crystal structure analyses. For complex: crystal system, triclinic, space group, P-1, a = 9.4661(13), b = 10.3534(14), c = 13.0025(18) Å, α = 73.477(2), β = 80.743(2), γ = 88.658(2)°, V = 1205.5(3) Å3, Z = 2. In this complex, the Zn2+ distorted tetrahedron geometry is coordinated by two nitrogen atoms from 2-(2-(1H-benzo[d]imidazol-2-yl)benzyl)-1H-benzo[d]imidazole and two Cl-. The complex emits yellow green luminescence with the maximal emission peak at 550 nm in DMF solution. The complex exhibits inhibition on the growth of Eca109 cancer cell with IC50 value of 8.9 ± 1.1 μM, which was lower than that of cisplatin (14.3 ± 1.4 μM). This complex has potential application in treatment of esophageal cancer.

Pharmacokinetic parameters explain the therapeutic activity of antimicrobial agents in a silkworm infection model.

PubMed

Paudel, Atmika; Panthee, Suresh; Urai, Makoto; Hamamoto, Hiroshi; Ohwada, Tomohiko; Sekimizu, Kazuhisa

2018-01-25

Poor pharmacokinetic parameters are a major reason for the lack of therapeutic activity of some drug candidates. Determining the pharmacokinetic parameters of drug candidates at an early stage of development requires an inexpensive animal model with few associated ethical issues. In this study, we used the silkworm infection model to perform structure-activity relationship studies of an antimicrobial agent, GPI0039, a novel nitrofuran dichloro-benzyl ester, and successfully identified compound 5, a nitrothiophene dichloro-benzyl ester, as a potent antimicrobial agent with superior therapeutic activity in the silkworm infection model. Further, we compared the pharmacokinetic parameters of compound 5 with a nitrothiophene benzyl ester lacking chlorine, compound 7, that exerted similar antimicrobial activity but had less therapeutic activity in silkworms, and examined the metabolism of these antimicrobial agents in human liver fractions in vitro. Compound 5 had appropriate pharmacokinetic parameters, such as an adequate half-life, slow clearance, large area under the curve, low volume of distribution, and long mean residence time, compared with compound 7, and was slowly metabolized by human liver fractions. These findings suggest that the therapeutic effectiveness of an antimicrobial agent in the silkworms reflects appropriate pharmacokinetic properties.

Small Molecule Anticonvulsant Agents with Potent In Vitro Neuroprotection

PubMed Central

Smith, Garry R.; Zhang, Yan; Du, Yanming; Kondaveeti, Sandeep K.; Zdilla, Michael J.; Reitz, Allen B.

2012-01-01

Severe seizure activity is associated with recurring cycles of excitotoxicity and oxidative stress that result in progressive neuronal damage and death. Intervention to halt these pathological processes is a compelling disease-modifying strategy for the treatment of seizure disorders. In the present study, a core small molecule with anticonvulsant activity has been structurally optimized for neuroprotection. Phenotypic screening of rat hippocampal cultures with nutrient medium depleted of antioxidants was utilized as a disease model. Increased cell death and decreased neuronal viability produced by acute treatment with glutamate or hydrogen peroxide were prevented by our novel molecules. The neuroprotection associated with this chemical series has marked structure activity relationships that focus on modification of the benzylic position of a 2-phenyl-2-hydroxyethyl sulfamide core structure. Complete separation between anticonvulsant activity and neuroprotective action was dependent on substitution at the benzylic carbon. Chiral selectivity was evident in that the S-enantiomer of the benzylic hydroxy group had neither neuroprotective nor anticonvulsant activity, while the R-enantiomer of the lead compound had full neuroprotective action at ≤40 nM and antiseizure activity in three animal models. These studies indicate that potent, multifunctional neuroprotective anticonvulsants are feasible within a single molecular entity. PMID:22535312

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'.

Crystal structure of bis-(benzyl-amine-κN)[5,10,15,20-tetra-kis-(4-chloro-phen-yl)porphyrinato-κ(4) N]iron(II) n-hexane monosolvate.

PubMed

Dhifaoui, Selma; Harhouri, Wafa; Bujacz, Anna; Nasri, Habib

2016-01-01

In the title compound, [Fe(II)(C44H24Cl4N4)(C6H5CH2NH2)2]·C6H14 or [Fe(II)(TPP-Cl)(BzNH2)2]·n-hexane [where TPP-Cl and BzNH2 are 5,10,15,20-tetra-kis-(4-chloro-phen-yl)porphyrinate and benzyl-amine ligands, respectively], the Fe(II) cation lies on an inversion centre and is octa-hedrally coordinated by the four pyrrole N atoms of the porphyrin ligand in the equatorial plane and by two amine N atoms of the benzyl-amine ligand in the axial sites. The crystal structure also contains one inversion-symmetric n-hexane solvent mol-ecule per complex mol-ecule. The average Fe-Npyrrole bond length [1.994 (3) Å] indicates a low-spin complex. The crystal packing is sustained by N-H⋯Cl and C-H⋯Cl hydrogen-bonding inter-actions and by C-H⋯π inter-molecular inter-actions, leading to a three-dimensional network structure.

Structure-activity relationships of substituted N-benzyl piperidines in the GBR series: Synthesis of 4-(2-(bis(4-fluorophenyl)methoxy)ethyl)-1-(2-trifluoromethylbenzyl)piperidine, an allosteric modulator of the serotonin transporter.

PubMed

Boos, Terrence L; Greiner, Elisabeth; Calhoun, W Jason; Prisinzano, Thomas E; Nightingale, Barbara; Dersch, Christina M; Rothman, Richard B; Jacobson, Arthur E; Rice, Kenner C

2006-06-01

A series of 4-(2-(bis(4-fluorophenyl)methoxy)ethyl)-(substituted benzyl) piperidines with substituents at the ortho and meta positions in the aromatic ring of the N-benzyl side chain were synthesized and their affinities and selectivities for the dopamine transporter (DAT), serotonin transporter (SERT), and norepinephrine transporter (NET) were determined. One analogue, 4-(2-(bis(4-fluorophenyl)methoxy)ethyl)-1-(2-trifluoromethylbenzyl)piperidine (the C(2)-trifluoromethyl substituted compound), has been found to act as an allosteric modulator of hSERT binding and function. It had little affinity for any of the transporters. Several compounds showed affinity for the DAT in the low nanomolar range and displayed a broad range of SERT/DAT selectivity ratios and very little affinity for the NET. The pharmacological tools provided by the availability of compounds with varying transporter affinity and selectivity could be used to obtain additional information about the properties a compound should have to act as a useful pharmacotherapeutic agent for cocaine addiction and help unravel the pharmacological mechanisms relevant to stimulant abuse.

THE REDUCTION OF NITRATE, NITRITE AND HYDROXYLAMINE TO AMMONIA BY ENZYMES FROM CUCURBITA PEPO L. IN THE PRESENCE OF REDUCED BENZYL VIOLOGEN AS ELECTRON DONOR.

PubMed

CRESSWELL, C F; HAGEMAN, R H; HEWITT, E J; HUCKLESBY, D P

1965-01-01

1. Enzyme systems from Cucurbita pepo have been shown to catalyse the reduction of nitrite and hydroxylamine to ammonia in yields about 90-100%. 2. Reduced benzyl viologen serves as an efficient electron donor for both systems. Activity of the nitrite-reductase system is directly related to degree of dye reduction when expressed in terms of the function for oxidation-reduction potentials, but appears to decrease to negligible activity below about 9% dye reduction. 3. NADH and NADPH alone produce negligible nitrite loss, but NADPH can be linked to an endogenous diaphorase system to reduce nitrite to ammonia in the presence of catalytic amounts of benzyl viologen. 4. The NADH- or NADPH-nitrate-reductase system that is also present can accept electrons from reduced benzyl viologen, but shows relationships opposite to that for the nitrite-reductase system with regard to effect of degree of dye reduction on activity. The product of nitrate reduction may be nitrite alone, or nitrite and ammonia, or ammonia alone, according only to the degree of dye reduction. 5. The relative activities of nitrite-reductase and hydroxylamine-reductase systems show different relationships with degree of dye reduction and may become reversed in magnitude when effects of degree of dye reduction are tested over a suitable range. 6. Nitrite severely inhibits the rate of reduction of hydroxylamine without affecting the yield of ammonia as a percentage of total substrate loss, but hydroxylamine has a negligible effect on the activity of the nitrite-reductase system. 7. The apparent K(m) for nitrite (1 mum) is substantially less than that for hydroxylamine, for which variable values between 0.05 and 0.9mm (mean 0.51 mm) have been observed. 8. The apparent K(m) values for reduced benzyl viologen differ for the nitrite-reductase and hydroxylamine-reductase systems: 60 and 7.5 mum respectively. 9. It is concluded that free hydroxylamine may not be an intermediate in the reduction of nitrite to ammonia by plants, and a possible mechanism for reduction of both compounds by the same enzyme system is discussed in the light of current ideas relating to other organisms.

The reduction of nitrate, nitrite and hydroxylamine to ammonia by enzymes from Cucurbita pepo L. in the presence of reduced benzyl viologen as electron donor

PubMed Central

Cresswell, C. F.; Hageman, R. H.; Hewitt, E. J.; Hucklesby, D. P.

1965-01-01

1. Enzyme systems from Cucurbita pepo have been shown to catalyse the reduction of nitrite and hydroxylamine to ammonia in yields about 90–100%. 2. Reduced benzyl viologen serves as an efficient electron donor for both systems. Activity of the nitrite-reductase system is directly related to degree of dye reduction when expressed in terms of the function for oxidation–reduction potentials, but appears to decrease to negligible activity below about 9% dye reduction. 3. NADH and NADPH alone produce negligible nitrite loss, but NADPH can be linked to an endogenous diaphorase system to reduce nitrite to ammonia in the presence of catalytic amounts of benzyl viologen. 4. The NADH– or NADPH–nitrate-reductase system that is also present can accept electrons from reduced benzyl viologen, but shows relationships opposite to that for the nitrite-reductase system with regard to effect of degree of dye reduction on activity. The product of nitrate reduction may be nitrite alone, or nitrite and ammonia, or ammonia alone, according only to the degree of dye reduction. 5. The relative activities of nitrite-reductase and hydroxylamine-reductase systems show different relationships with degree of dye reduction and may become reversed in magnitude when effects of degree of dye reduction are tested over a suitable range. 6. Nitrite severely inhibits the rate of reduction of hydroxylamine without affecting the yield of ammonia as a percentage of total substrate loss, but hydroxylamine has a negligible effect on the activity of the nitrite-reductase system. 7. The apparent Km for nitrite (1 μm) is substantially less than that for hydroxylamine, for which variable values between 0·05 and 0·9mm (mean 0·51 mm) have been observed. 8. The apparent Km values for reduced benzyl viologen differ for the nitrite-reductase and hydroxylamine-reductase systems: 60 and 7·5 μm respectively. 9. It is concluded that free hydroxylamine may not be an intermediate in the reduction of nitrite to ammonia by plants, and a possible mechanism for reduction of both compounds by the same enzyme system is discussed in the light of current ideas relating to other organisms. PMID:14342247

Asymmetric Benzylic Allylic Alkylation Reaction of 3-Furfural Derivatives by Dearomatizative Dienamine Activation.

PubMed

He, Xiao-Long; Zhao, Hui-Ru; Duan, Chuan-Qi; Han, Xu; Du, Wei; Chen, Ying-Chun

2018-04-20

The dearomatizative dienamine-type ortho-quinodimethane species are smoothly generated between 2-alkyl-3-furfurals and chiral secondary amine catalysts, which undergo asymmetric benzylic allylic alkylation reactions with 2-nitroallylic acetates efficiently. A spectrum of densely functionalized 3-furfural derivatives are delivered in moderate to high yields with good to excellent diastereo- and enantioselectivity (up to 98 % yield, >19:1 d.r., >99 % ee). The latent transformations allow the facile production of some enantioenriched architectures, such as 1,1,2,2-tetraarylethanes and triarylmethanes, which are not easily available from other protocols. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Synthesis of novel di- and tricationic carbapenems with potent anti-MRSA activity.

PubMed

Maruyama, Takahisa; Yamamoto, Yasuo; Kano, Yuko; Kurazono, Mizuyo; Shitara, Eiki; Iwamatsu, Katsuyoshi; Atsumi, Kunio

2009-01-15

A new series of 1beta-methyl carbapenems possessing a 6,7-disubstituted imidazo[5,1-b]thiazol-2-yl group directly attached to the C-2 position of the carbapenem nucleus was prepared, and their activities against methicillin-resistant Staphylococcus aureus (MRSA) were evaluated. First, a benzyl moiety was introduced at the C-6 position of imidazo[5,1-b]thiazole attached to the carbapenem. These benzylated molecules showed potent anti-MRSA activity, but poor water solubility. In order to overcome this drawback, we designed and synthesized di- and tricationic carbapenems and finally discovered a novel carbapenem (15i), which exhibited excellent anti-MRSA activity and good water solubility.

Synthesis and anti-cancer activity of chiral tetrahydropyrazolo[1,5-a]pyridine-fused steroids.

PubMed

Lopes, Susana M M; Sousa, Emanuel P; Barreira, Luísa; Marques, Cátia; Rodrigues, Maria João; Pinho E Melo, Teresa M V D

2017-06-01

Regio- and stereoselective synthesis of novel chiral 4,5,6,7-tetrahydropyrazolo[1,5-a]pyridine-fused steroids via [8π+2π] cycloaddition of diazafulvenium methides with steroidal scaffolds is reported. The biological evaluation of the new family of hexacyclic steroids as anti-cancer agents was also carried out. Hexacyclic steroids bearing a benzyl group at C-22, derived from 16-dehydropregnenolone and 16-dehydroprogesterone, show considerable cytotoxicity against EL4 (murine T-lymphoma) in contrast with the corresponding C-22-unsubstituted derivatives showing low cytotoxicity. Thus, results indicate that the presence of the benzyl group is important to ensure cytotoxicity. Copyright © 2017 Elsevier Inc. All rights reserved.

3-O-Benzyl-6-O-benzoyl-1,2-O-isopropil­idene-5-C-nitro­methyl-a-d-glucofuran­ose

PubMed Central

Pampín, Begoña; Valencia, Laura; Estévez, Juan C.; Estévez, Ramón J.

2009-01-01

The title compound, C24H27NO9, is one of the epimers of the Henry reaction of 3-O-benzyl-6-O-benzoyl-2-O-isopropyl­idene-a-d-glucofuran-5-one with nitro­methane. The conformation of the five membered rings is as expected from the precursor compound and the mol­ecule is folded with a dihedral angle of 51.4 (2)° between the aromatic rings. One O—H⋯O hydrogen bond and some intra­molecular and inter­molecular C—H⋯O inter­actions are observed in the structure. PMID:21581936

Novel coumarin derivatives bearing N-benzyl pyridinium moiety: potent and dual binding site acetylcholinesterase inhibitors.

PubMed

Alipour, Masoumeh; Khoobi, Mehdi; Foroumadi, Alireza; Nadri, Hamid; Moradi, Alireza; Sakhteman, Amirhossein; Ghandi, Mehdi; Shafiee, Abbas

2012-12-15

A novel series of coumarin derivatives linked to benzyl pyridinium group were synthesized and biologically evaluated as inhibitors of both acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE). The enzyme inhibitory activity of synthesized compounds was measured using colorimetric Ellman's method. It was revealed that compounds 3e, 3h, 3l, 3r and 3s have shown higher activity compared with donepezil hydrochloride as standard drug. Most of the compounds in these series had nanomolar range IC(50) in which compound 3r (IC(50) = 0.11 nM) was the most active compound against acetylcholinesterase enzyme. Copyright © 2012 Elsevier Ltd. All rights reserved.

Infrared Spectra and Band Strengths of CH3SH, an Interstellar Molecule

NASA Technical Reports Server (NTRS)

Hudson, R. L.

2016-01-01

Three solid phases of CH3SH (methanethiol or methyl mercaptan) have been prepared and their mid-infrared spectra recorded at 10-110 degrees Kelvin, with an emphasis on the 17-100 degrees Kelvin region. Refractive indices have been measured at two temperatures and used to estimate ice densities and infrared band strengths. Vapor pressures for the two crystalline phases of CH3SH at 110 degrees Kelvin are estimated. The behavior of amorphous CH3SH on warming is presented and discussed in terms of Ostwald's step rule. Comparisons to CH3OH under similar conditions are made, and some inconsistencies and ambiguities in the CH3SH literature are examined and corrected.

Starting of rocket engine at conditions of simulated altitude using crude monoethylaniline and other fuels with mixed acid

NASA Technical Reports Server (NTRS)

Ladanyi, Dezso J; Sloop, John L; Humphrey, Jack C; Morrell, Gerald

1950-01-01

Experiments were conducted at sea level and pressure altitude of about 55,000 feet at various temperatures to determine starting characteristics of a commercial rocket engine using crude monoethylaniline and other fuels with mixed acid. With crude monoethylaniline, ignition difficulties were encountered at temperatures below about 20 degrees F. With mixed butyl mercaptans, water-white turpentine, and x-pinene, no starting difficulties were experienced at temperatures as low as minus 74 degrees F. Turpentine and x-pinene, however, sometimes left deposits on the injector face. With blends containing furfuryl alcohol and with other blends, difficulties were experienced either from appreciable deposits or from starting.

Crystal structure of N′′-benzyl-N′′-[3-(benzyl­dimethyl­aza­nium­yl)prop­yl]-N,N,N′,N′-tetra­methyl­guanidinium bis­(tetra­phenyl­borate)

PubMed Central

Tiritiris, Ioannis; Kantlehner, Willi

2015-01-01

In the crystal structure of the title salt, C24H38N4 2+·2C24H20B−, the C—N bond lengths in the central CN3 unit of the guanidinium ion are 1.3364 (13), 1.3407 (13) and 1.3539 (13) Å, indicating partial double-bond character. The central C atom is bonded to the three N atoms in a nearly ideal trigonal–planar geometry and the positive charge is delocalized in the CN3 plane. The bonds between the N atoms and the terminal methyl groups of the guanidinium moiety and the four C—N bonds to the central N atom of the (benzyl­dimethyl­aza­nium­yl)propyl group have single-bond character. In the crystal, C—H⋯π inter­actions between the guanidin­ium H atoms and the phenyl C atoms of the tetra­phenyl­borate ions are present, leading to the formation of a two-dimensional supra­molecular pattern parallel to the ac plane. PMID:26870511

A study of antagonists of 5-hydroxytryptamine and catechol amines on the rat's blood pressure.

PubMed

OUTSCHOORN, A S; JACOB, J

1960-03-01

The effects of 5-hydroxytryptamine on the blood pressure of anaesthetized rats depended on the dose and the initial level of blood pressure. At medium blood pressure levels, 5-hydroxytryptamine gave a depressor response and sometimes a pressor response which was more evident with large doses. The depressor effect was less apparent or even absent at low, and more pronounced at high, blood pressure levels, and the converse applied to the pressor components. Adenosine also gave a depressor and pressor response. Lysergic acid diethylamide, dihydroergotamine, 1-(3,4-dichlorophenyl)-2-isopropylaminoethanol (a dichloro analogue of isoprenaline), dibenamine and 1-benzyl-5-methoxy-2-methyltryptamine antagonized 5-hydroxytryptamine and catechol amines. Lysergic acid diethylamide and 1-benzyl-5-methoxy-2-methyltryptamine were more effective against 5-hydroxytryptamine, 1-(3,4-dichlorophenyl)-2-isopropylaminoethanol and dibenamine against catechol amines; dihydroergotamine was equally effective against both groups. These antagonists fell into two groups according to their action against the two types of effects (depressor and pressor) of 5-hydroxytryptamine: lysergic acid diethylamide and 1-(3,4-dichlorophenyl)2-isopropylaminoethanol acted preferentially against depressor effects; 1-benzyl-5-methoxy-2-methyltryptamine and dibenamine preferentially against pressor; dihydroergotamine was not assignable to either group. Adenosine was affected similarly, but less than 5-hydroxytryptamine.

A study of antagonists of 5-hydroxytryptamine and catechol amines on the rat's blood pressure

PubMed Central

Outschoorn, A. S.; Jacob, J.

1960-01-01

The effects of 5-hydroxytryptamine on the blood pressure of anaesthetized rats depended on the dose and the initial level of blood pressure. At medium blood pressure levels, 5-hydroxytryptamine gave a depressor response and sometimes a pressor response which was more evident with large doses. The depressor effect was less apparent or even absent at low, and more pronounced at high, blood pressure levels, and the converse applied to the pressor components. Adenosine also gave a depressor and pressor response. Lysergic acid diethylamide, dihydroergotamine, 1-(3,4-dichlorophenyl)-2-isopropylaminoethanol (a dichloro analogue of isoprenaline), dibenamine and 1-benzyl-5-methoxy-2-methyltryptamine antagonized 5-hydroxytryptamine and catechol amines. Lysergic acid diethylamide and 1-benzyl-5-methoxy-2-methyltryptamine were more effective against 5-hydroxytryptamine, 1-(3,4-dichlorophenyl)-2-isopropylaminoethanol and dibenamine against catechol amines; dihydroergotamine was equally effective against both groups. These antagonists fell into two groups according to their action against the two types of effects (depressor and pressor) of 5-hydroxytryptamine: lysergic acid diethylamide and 1-(3,4-dichlorophenyl)2-isopropylaminoethanol acted preferentially against depressor effects; 1-benzyl-5-methoxy-2-methyltryptamine and dibenamine preferentially against pressor; dihydroergotamine was not assignable to either group. Adenosine was affected similarly, but less than 5-hydroxytryptamine. PMID:14429484

Wetting characteristics and blood clotting on surfaces of copoly(gamma-Benzyl-L-glutamate, gamma-hydroxyethyl-L-glutamine).

PubMed

Yano, E; Komai, T; Kawasaki, T; Kaifu, K; Atsuta, T; Kubo, Y; Fujiwara, Y

1985-09-01

The film surface of poly(gamma-benzyl-L-glutamate) (PBLG) was modified with 2-aminoethanol to enhance its hydrophilicity. Controlling the reaction conditions of PBLG and 2-aminoethanol, various types of copoly(gamma-benzyl-L-glutamate, gamma-hydroxyethyl-L-glutamine) film surfaces were obtained. Surface free energy (gamma sv), the dispersive component of gamma sv (gamma dsv), the nondispersive component of gamma sv (gamma psv), and the interfacial free energy of polymer surface with water (gamma sw), which were obtained by using the contact angle measurement and calculation method proposed by Andrade et al., were changed remarkably by the aminolysis. The gamma sv value increased after 2 h of aminolysis from 48.2 (PBLG) to 65.3 dyn/cm and gradually increased to around 70 dyn/cm after 12 h reaction. (gamma dsv) and (gamma psv) changed from 31.0 and 17.2 dyn/cm (PBLG) to 26.5 and 44.3 dyn/cm, respectively. These parameters of the material surfaces, modified over 12 h reaction, were found to be similar to those of the surfaces of canine aorta, vein, and human fibrin membrane. Blood clotting times on these polymer surfaces were comparatively longer than on siliconized glass surfaces.

Direct synthesis of hydrogen peroxide and benzyl alcohol oxidation using Au-Pd catalysts prepared by sol immobilization.

PubMed

Pritchard, James; Kesavan, Lokesh; Piccinini, Marco; He, Qian; Tiruvalam, Ramchandra; Dimitratos, Nikolaos; Lopez-Sanchez, Jose A; Carley, Albert F; Edwards, Jennifer K; Kiely, Christopher J; Hutchings, Graham J

2010-11-02

We report the preparation of Au-Pd nanocrystalline catalysts supported on activated carbon prepared via a sol-immobilization technique and explore their use for the direct synthesis of hydrogen peroxide and the oxidation of benzyl alcohol. In particular, we examine the synthesis of a systematic set of Au-Pd colloidal nanoparticles having a range of Au/Pd ratios. The catalysts have been structurally characterized using a combination of UV-visible spectroscopy, transmission electron microscopy, STEM HAADF/XEDS, and X-ray photoelectron spectroscopy. The Au-Pd nanoparticles are found in the majority of cases to be homogeneous alloys, although some variation is observed in the AuPd composition at high Pd/Au ratios. The optimum performance for the synthesis of hydrogen peroxide is observed for a catalyst having a Au/Pd 1:2 molar ratio. However, the competing hydrogenation reaction of hydrogen peroxide increases with increasing Pd content, although Pd alone is less effective than when Au is also present. Investigation of the oxidation of benzyl alcohol using these materials also shows that the optimum selective oxidation to the aldehyde occurs for the Au/Pd 1:2 molar ratio catalyst. These measured activity trends are discussed in terms of the structure and composition of the supported Au-Pd nanoparticles.

Mechanism of Copper(I)/TEMPO-Catalyzed Aerobic Alcohol Oxidation

PubMed Central

Hoover, Jessica M.; Ryland, Bradford L.; Stahl, Shannon S.

2013-01-01

Homogeneous Cu/TEMPO catalyst systems (TEMPO = 2,2,6,6-tetramethylpiperidine-N-oxyl) have emerged as some of the most versatile and practical catalysts for aerobic alcohol oxidation. Recently, we disclosed a (bpy)CuI/TEMPO/NMI catalyst system (NMI = N-methylimidazole) that exhibits fast rates and high selectivities, even with unactivated aliphatic alcohols. Here, we present a mechanistic investigation of this catalyst system, in which we compare the reactivity of benzylic and aliphatic alcohols. This work includes analysis of catalytic rates by gas-uptake and in situ IR kinetic methods and characterization of the catalyst speciation during the reaction by EPR and UV–visible spectroscopic methods. The data support a two-stage catalytic mechanism consisting of (1) “catalyst oxidation” in which CuI and TEMPO–H are oxidized by O2 via a binuclear Cu2O2 intermediate and (2) “substrate oxidation” mediated by CuII and the nitroxyl radical of TEMPO via a CuII-alkoxide intermediate. Catalytic rate laws, kinetic isotope effects, and spectroscopic data show that reactions of benzylic and aliphatic alcohols have different turnover-limiting steps. Catalyst oxidation by O2 is turnover limiting with benzylic alcohols, while numerous steps contribute to the turnover rate in the oxidation of aliphatic alcohols. PMID:23317450

Rational synthesis of low-polydispersity block copolymer vesicles in concentrated solution via polymerization-induced self-assembly.

PubMed

Gonzato, Carlo; Semsarilar, Mona; Jones, Elizabeth R; Li, Feng; Krooshof, Gerard J P; Wyman, Paul; Mykhaylyk, Oleksandr O; Tuinier, Remco; Armes, Steven P

2014-08-06

Block copolymer self-assembly is normally conducted via post-polymerization processing at high dilution. In the case of block copolymer vesicles (or "polymersomes"), this approach normally leads to relatively broad size distributions, which is problematic for many potential applications. Herein we report the rational synthesis of low-polydispersity diblock copolymer vesicles in concentrated solution via polymerization-induced self-assembly using reversible addition-fragmentation chain transfer (RAFT) polymerization of benzyl methacrylate. Our strategy utilizes a binary mixture of a relatively long and a relatively short poly(methacrylic acid) stabilizer block, which become preferentially expressed at the outer and inner poly(benzyl methacrylate) membrane surface, respectively. Dynamic light scattering was utilized to construct phase diagrams to identify suitable conditions for the synthesis of relatively small, low-polydispersity vesicles. Small-angle X-ray scattering (SAXS) was used to verify that this binary mixture approach produced vesicles with significantly narrower size distributions compared to conventional vesicles prepared using a single (short) stabilizer block. Calculations performed using self-consistent mean field theory (SCMFT) account for the preferred self-assembled structures of the block copolymer binary mixtures and are in reasonable agreement with experiment. Finally, both SAXS and SCMFT indicate a significant degree of solvent plasticization for the membrane-forming poly(benzyl methacrylate) chains.

Quinone Methide Signal Amplification: Covalent Reporter Labeling of Cancer Epitopes using Alkaline Phosphatase Substrates.

PubMed

Polaske, Nathan W; Kelly, Brian D; Ashworth-Sharpe, Julia; Bieniarz, Christopher

2016-03-16

Diagnostic assays with the sensitivity required to improve cancer therapeutics depend on the development of new signal amplification technologies. Herein, we report the development and application of a novel amplification system which utilizes latent quinone methides (QMs) activated by alkaline phosphatase (AP) for signal amplification in solid-phase immunohistochemical (IHC) assays. Phosphate-protected QM precursor substrates were prepared and conjugated to either biotin or a fluorophore through an amine-functionalized linker group. Upon reaction with AP, the phosphate group is cleaved, followed by elimination of the leaving group and formation of the highly reactive and short-lived QM. The QMs either react with tissue nucleophiles in close proximity to their site of generation, or are quenched by nucleophiles in the reaction media. The reporter molecules that covalently bind to the tissue were then detected visually by fluorescence microscopy in the case of fluorophore reporters, or brightfield microscopy using diaminobenzidine (DAB) in the case of biotin reporters. With multiple reporters deposited per enzyme, significant signal amplification was observed utilizing QM precursor substrates containing either benzyl difluoro or benzyl monofluoro leaving group functionalities. However, the benzyl monofluoro leaving group gave superior results with respect to both signal intensity and discretion, the latter of which was found to be imperative for use in diagnostic IHC assays.

Correlation between the microstructures of graphite oxides and their catalytic behaviors in air oxidation of benzyl alcohol.

PubMed

Geng, Longlong; Wu, Shujie; Zou, Yongcun; Jia, Mingjun; Zhang, Wenxiang; Yan, Wenfu; Liu, Gang

2014-05-01

A series of graphite oxide (GO) materials were obtained by thermal treatment of oxidized natural graphite powder at different temperatures (from 100 to 200 °C). The microstructure evolution (i.e., layer structure and surface functional groups) of the graphite oxide during the heating process is studied by various characterization means, including XRD, N2 adsorption, TG-DTA, in situ DRIFT, XPS, Raman, TEM and Boehm titration. The characterization results show that the structures of GO materials change gradually from multilayer sheets to a transparent ultrathin 2D structure of the carbon sheets. The concentration of surface COH and HOCO groups decrease significantly upon treating temperature increasing. Benzyl alcohol oxidation with air as oxidant source was carried out to detect the catalytic behaviors of different GO materials. The activities of GO materials decrease with the increase of treating temperatures. It shows that the structure properties, including ultrathin sheets and high specific surface area, are not crucial factors affecting the catalytic activity. The type and amount of surface oxygen-containing functional groups of GO materials tightly correlates with the catalytic performance. Carboxylic groups on the surface of GO should act as oxidative sites for benzyl alcohol and the reduced form could be reoxidized by molecular oxygen. Copyright © 2014 Elsevier Inc. All rights reserved.

Equilibrium Acidities and Homolytic Bond Dissociation Enthalpies of the Acidic C-H Bonds in P-(Para-substituted benzyl)triphenylphosphonium Cations and Related Cations.

PubMed

Zhang, Xian-Man; Fry, Albert J.; Bordwell, Frederick G.

1996-06-14

Equilibrium acidities (pK(HA)) of six P-(para-substituted benzyl)triphenylphosphonium (p-GC(6)H(4)CH(2)PPh(3)(+)) cations, P-allyltriphenylphosphonium cation, P-cinnamyltriphenylphosphonium cation, and As-(p-cyanobenzyl)triphenylarsonium cation, together with the oxidation potentials [E(ox)(A(-))] of their conjugate anions (ylides) have been measured in dimethyl sulfoxide (DMSO) solution. The acidifying effects of the alpha-triphenylphosphonium groups on the acidic C-H bonds in toluene and propene were found to be ca 25 pK(HA) units (34 kcal/mol). Introduction of an electron-withdrawing group such as 4-NO(2), 4-CN, or 4-Br into the para position of the benzyl ring in p-GC(6)H(4)CH(2)PPh(3)(+) cations resulted in an additional acidity increase, but introduction of the 4-OEt electron-donating group decreases the acidity. The equilibrium acidities of p-GC(6)H(4)CH(2)PPh(3)(+) cations were nicely linearly correlated with the Hammett sigma(-) constants of the substituents (G) with a slope of 4.78 pK(HA) units (R(2) = 0.992) (Figure 1). Reversible oxidation potentials of the P-(para-substituted benzyl)triphenylphosphonium ylides were obtained by fast scan cyclic voltammetry. The homolytic bond dissociation enthalpies (BDEs) of the acidic C-H bonds in these cations, estimated by combining their equilibrium acidities with the oxidation potentials of their corresponding conjugate anions, showed that the alpha-Ph(3)P(+) groups have negligible stabilizing or destabilizing effects on the adjacent radicals. The equilibrium acidity of As-(p-cyanobenzyl)triphenylarsonium cation is 4 pK(HA) units weaker than that of P-(p-cyanobenzyl)triphenylphosphonium cation, but the BDE of the acidic C-H bond in As-(p-cyanobenzyl)triphenylarsonium cation is ca 2 kcal/mol higher than that in P-(p-cyanobenzyl)triphenylphosphonium cation.

New cobalt(II) and nickel(II) complexes of benzyl carbazate Schiff bases: Syntheses, crystal structures, in vitro DNA and HSA binding studies.

PubMed

Nithya, Palanivelu; Helena, Sannasi; Simpson, Jim; Ilanchelian, Malaichamy; Muthusankar, Aathi; Govindarajan, Subbiah

2016-12-01

In the present study, new Schiff base complexes with the composition [M(NCS) 2 (L1) 2 ]·nH 2 O, where M=Co (n=0) (1) and Ni (n=2) (2); [M(NCS) 2 (L2) 2 ], M=Co (3) and Ni (4) as well as [M(NCS) 2 (L3) 2 ], M=Co (5) and Ni (6); (L1=benzyl 2-(propan-2-ylidene)hydrazinecarboxylate, L2=benzyl 2-(butan-2-ylidene)hydrazinecarboxylate and L3=benzyl 2-(pentan-3-ylidene)hydrazinecarboxylate) have been synthesized by a template method. The complexes were characterised by analytical methods, spectroscopic studies, thermal and X-ray diffraction techniques. The structures of all the complexes explore that the metal(II) cation has a trans-planar coordination environment, the monomeric units containing a six-coordinated metal center in octahedral geometry with N-bound isothiocyanate anions coordinated as terminal ligands. Furthermore, the binding of the two Schiff base ligands to the metal centers involves the azomethine nitrogen and the carbonyl oxygen in mutually trans configuration. The binding interactions of all the complexes with Calf thymus-deoxyribonucleic acid (CT-DNA) and human serum albumin (HSA) have been investigated using absorption and emission spectral techniques. The CT-DNA binding properties of these complexes reveal that they bind to CT-DNA through a partial intercalation mode and the binding constant values were calculated using the absorption and emission spectral data. The binding constant values (~10×10 6 moldm -3 ) indicate strong binding of metal complexes with CT-DNA. HSA binding interaction studies showed that the cobalt and nickel complexes can quench the intrinsic fluorescence of HSA through static quenching process. Also, molecular docking studies were supported out to apprehend the binding interactions of these complexes with DNA and HSA which offer new understandings into the experimental model observations. Copyright © 2016 Elsevier B.V. All rights reserved.

Quantitative production of compound I from a cytochrome P450 enzyme at low temperatures. Kinetics, activation parameters, and kinetic isotope effects for oxidation of benzyl alcohol.

PubMed

Wang, Qin; Sheng, Xin; Horner, John H; Newcomb, Martin

2009-08-05

Cytochrome P450 enzymes are commonly thought to oxidize substrates via an iron(IV)-oxo porphyrin radical cation transient termed Compound I, but kinetic studies of P450 Compounds I are essentially nonexistent. We report production of Compound I from cytochrome P450 119 (CYP119) in high conversion from the corresponding Compound II species at low temperatures in buffer mixtures containing 50% glycerol by photolysis with 365 nm light from a pulsed lamp. Compound I was studied as a reagent in oxidations of benzyl alcohol and its benzylic mono- and dideuterio isotopomers. Pseudo-first-order rate constants obtained at -50 degrees C with concentrations of substrates between 1.0 and 6.0 mM displayed saturation kinetics that gave binding constants for the substrate in the Compound I species (K(bind)) and first-order rate constants for the oxidation reactions (k(ox)). Representative results are K(bind) = 214 M(-1) and k(ox) = 0.48 s(-1) for oxidation of benzyl alcohol. For the dideuterated substrate C(6)H(5)CD(2)OH, kinetics were studied between -50 and -25 degrees C, and a van't Hoff plot for complexation and an Arrhenius plot for the oxidation reaction were constructed. The H/D kinetic isotope effects (KIEs) at -50 degrees C were resolved into a large primary KIE (P = 11.9) and a small, inverse secondary KIE (S = 0.96). Comparison of values extrapolated to 22 degrees C of both the rate constant for oxidation of C(6)H(5)CD(2)OH and the KIE for the nondeuterated and dideuterated substrates to values obtained previously in laser flash photolysis experiments suggested that tunneling could be a significant component of the total rate constant at -50 degrees C.

Benzylic oxidation of gemfibrozil-1-O-beta-glucuronide by P450 2C8 leads to heme alkylation and irreversible inhibition.

PubMed

Baer, Brian R; DeLisle, Robert Kirk; Allen, Andrew

2009-07-01

Gemfibrozil-1-O-beta-glucuronide (GEM-1-O-gluc), a major metabolite of the antihyperlipidemic drug gemfibrozil, is a mechanism-based inhibitor of P450 2C8 in vitro, and this irreversible inactivation may lead to clinical drug-drug interactions between gemfibrozil and other P450 2C8 substrates. In light of this in vitro finding and the observation that the glucuronide conjugate does not contain any obvious structural alerts, the current study was conducted to determine the potential site of GEM-1-O-gluc bioactivation and the subsequent mechanism of P450 2C8 inhibition (i.e., modification of apoprotein or heme). LC/MS analysis of a reaction mixture containing recombinant P450 2C8 and GEM-1-O-gluc revealed that the substrate was covalently linked to the heme prosthetic heme group during catalysis. A combination of mass spectrometry and deuterium isotope effects revealed that a benzylic carbon on the 2',5'-dimethylphenoxy group of GEM-1-O-gluc was covalently bound to the heme of P450 2C8. The regiospecificity of substrate addition to the heme group was not confirmed experimentally, but computational modeling experiments indicated that the gamma-meso position was the most likely site of modification. The metabolite profile, which consisted of two benzyl alcohol metabolites and a 4'-hydroxy-GEM-1-O-gluc metabolite, indicated that oxidation of GEM-1-O-gluc was limited to the 2',5'-dimethylphenoxy group. These results are consistent with an inactivation mechanism wherein GEM-1-O-gluc is oxidized to a benzyl radical intermediate, which evades oxygen rebound, and adds to the gamma-meso position of heme. Mechanism-based inhibition of P450 2C8 can be rationalized by the formation of the GEM-1-O-gluc-heme adduct and the consequential restriction of additional substrate access to the catalytic iron center.

Determination of suspected allergens in cosmetic products by headspace-programmed temperature vaporization-fast gas chromatography-quadrupole mass spectrometry.

PubMed

del Nogal Sánchez, Miguel; Pérez-Pavón, José Luis; Moreno Cordero, Bernardo

2010-07-01

In the present work, a strategy for the qualitative and quantitative analysis of 24 volatile compounds listed as suspected allergens in cosmetics by the European Union is reported. The list includes benzyl alcohol, limonene, linalool, methyl 2-octynoate, beta-citronellol, geraniol, citral (two isomers), 7-hydroxycitronellal, anisyl alcohol, cinnamal, cinnamyl alcohol, eugenol, isoeugenol (two isomers), coumarin, alpha-isomethyl ionone, lilial, alpha-amylcinnamal, lyral, alpha-amylcinnamyl alcohol, farnesol (three isomers), alpha-hexyl cinnamal, benzyl cinnamate, benzyl benzoate, and benzyl salicylate. The applicability of a headspace (HS) autosampler in combination with a gas chromatograph (GC) equipped with a programmable temperature vaporizer (PTV) and a quadrupole mass spectrometry (qMS) detector is explored. By using a headspace sampler, sample preparation is reduced to introducing the sample into the vial. This reduces the analysis time and the experimental errors associated with this step of the analytical process. Two different injection techniques were used: solvent-vent injection and hot-split injection. The first offers a way to improve sensitivity at the same time maintaining the simple headspace instrumentation and it is recommended for compounds at trace levels. The use of a liner packed with Tenax-TA allowed the compounds of interest to be retained during the venting process. The signals obtained when hot-split injection was used allowed quantification of all the compounds according to the thresholds of the European Cosmetics Directive. Monodimensional gas chromatography coupled to a conventional quadrupole mass spectrometry detector was used and the 24 analytes were separated appropriately along a run time of about 12 min. Use of the standard addition procedure as a quantification technique overcame the matrix effect. It should be emphasized that the method showed good precision and accuracy. Furthermore, it is rapid, simple, and--in view of the results--highly suitable for the determination of suspected allergens in different cosmetic products.

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

40 CFR 469.22 - Specialized definitions.

Code of Federal Regulations, 2014 CFR

2014-07-01

... Trichloroethane methylene chloride naphthalene 2 Nitrophenol phenol bis (2-ethylhexyl) phthalate...-butyl phthalate anthracene 1,2 Diphenylhydrazine isophorone butyl benzyl pthalate 1,1 Dichloroethylene 2...

40 CFR 469.22 - Specialized definitions.

Code of Federal Regulations, 2012 CFR

2012-07-01

... Trichloroethane methylene chloride naphthalene 2 Nitrophenol phenol bis (2-ethylhexyl) phthalate...-butyl phthalate anthracene 1,2 Diphenylhydrazine isophorone butyl benzyl pthalate 1,1 Dichloroethylene 2...

Development and comparative investigation of Ag-sensitive layer based SAW and QCM sensors for mercury sensing applications.

PubMed

Kabir, K M Mohibul; Sabri, Ylias M; Kandjani, Ahmad Esmaielzadeh; Ippolito, Samuel J; Bhargava, Suresh K

2016-04-21

Piezoelectric acoustic wave devices integrated with noble metal surfaces provide exciting prospects for the direct measurement of toxic gas species such as mercury (Hg) in the atmosphere. Even though gold (Au) based acoustic wave sensors have been utilized extensively for detecting Hg, the potential of using other metal surfaces such as silver (Ag) is yet to be thoroughly studied. Here, we developed Ag sensitive layer-based surface acoustic wave (SAW) and quartz crystal microbalance (QCM) sensors and focused on their comparative analysis for Hg sensing applications with parameters such as the sensor sensitivity, selectivity, adsorption/desorption isotherm and Hg diffusion into the surface thoroughly studied. The SAW sensor was fabricated with nickel (Ni) interdigitated transducer (IDT) electrodes and a Ag thin film on the delay line of the device. In the case of the QCM sensor, the electrodes were constructed of Ag thin film and simultaneously employed as a sensitive layer. Mercury sensing experiments were conducted for a range of concentrations between 24-365 ppbv without/with the presence of some common industrial interfering gas species (i.e. ammonia, acetaldehyde, ethyl mercaptan, dimethyl disulphide, methyl ethyl ketone and humidity) at various operating temperatures in the range of 35-95 °C. The SAW sensor was found to possess up to 70 times higher response magnitudes than its QCM counterpart at 35 °C while up to 30 and 23 times higher response magnitudes were observed for the SAW sensor at elevated temperatures of 75 and 95 °C, respectively. Furthermore, the SAW sensor showed good selectivity (>89%) toward Hg(0) vapor in the presence of all the interferents tested at an operating temperature of 75 °C while the QCM sensor exhibited significant cross-sensitivity when ethyl mercaptan was introduced along with Hg(0) vapor. Overall, it is indicative that Ag-based acoustic wave sensors do have great potential for Hg sensing applications, given that right operating conditions are applied.

Porphyromonas gingivalis hydrogen sulfide enhances methyl mercaptan-induced pathogenicity in mouse abscess formation.

PubMed

Nakamura, Suguru; Shioya, Koki; Hiraoka, B Yukihiro; Suzuki, Nao; Hoshino, Tomonori; Fujiwara, Taku; Yoshinari, Nobuo; Ansai, Toshihiro; Yoshida, Akihiro

2018-04-01

Porphyromonas gingivalis produces hydrogen sulfide (H2S) from l-cysteine. However, the role of H2S produced by P. gingivalis in periodontal inflammation is unclear. In this study, we identified the enzyme that catalyses H2S production from l-cysteine and analysed the role of H2S using a mouse abscess model. The enzyme identified was identical to methionine γ-lyase (PG0343), which produces methyl mercaptan (CH3SH) from l-methionine. Therefore, we analysed H2S and CH3SH production by P. gingivalis W83 and a PG0343-deletion mutant (ΔPG0343) with/without l-cysteine and/or l-methionine. The results indicated that CH3SH is produced constitutively irrespective of the presence of l-methionine, while H2S was greatly increased by both P. gingivalis W83 and ΔPG0343 in the presence of l-cysteine. In contrast, CH3SH production by ΔPG0343 was absent irrespective of the presence of l-methionine, and H2S production was eliminated in the absence of l-cysteine. Thus, CH3SH and H2S production involves different substrates, l-methionine or l-cysteine, respectively. Based on these characteristics, we analysed the roles of CH3SH and H2S in abscess formation in mice by P. gingivalis W83 and ΔPG0343. Abscess formation by P. gingivalis W83, but not ΔPG0343, differed significantly in the presence and absence of l-cysteine. In addition, the presence of l-methionine did not affect the size of abscesses generated by P. gingivalis W83 and ΔPG0343. Therefore, we conclude that H2S produced by P. gingivalis does not induce inflammation; however, H2S enhances inflammation caused by CH3SH. Thus, these results suggest the H2S produced by P. gingivalis plays a supportive role in inflammation caused by methionine γ-lyase.

The South Karelia Air Pollution Study. The effects of malodorous sulfur compounds from pulp mills on respiratory and other symptoms

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

Jaakkola, J.J.; Vilkka, V.; Marttila, O.

1990-12-01

The paper mills in South Karelia, the southeast part of Finland, are responsible for releasing a substantial amount of malodorous sulfur compounds such as hydrogen sulfide (H2S), methyl mercaptan (CH3SH), and methyl sulfides ((CH3)2S and (CH3)2S2), into ambient air. In the most polluted residential area the annual mean concentrations of hydrogen sulfide and methyl mercaptan are estimated to be 8 and 2 to 5 micrograms/m3 and the highest daily average concentration 100 and 50 micrograms/m3. The annual mean and highest daily concentrations of sulfur dioxide (SO2) are very low. We studied the effects of malodorous sulfur compounds on eye, nasalmore » and respiratory symptoms, and headache in adults. A cross-sectional self-administered questionnaire was distributed in February 1987 and responded to by 488 adults living in a severely (n = 198), a moderately (n = 204), and a nonpolluted community (n = 86). This included questions about occurrence of the symptoms of interest during the previous 4 wk and 12 months and individual, behavioral, and other environmental determinants of the symptoms. The response rate was 83%. The odds ratios (OR) for symptoms experienced often or constantly in severely versus nonpolluted and moderately versus nonpolluted communities were estimated in logistic regression analysis controlling potential confounders. The odds ratios for eye (moderate exposure OR 11.70, Cl95% 2.33 to 58.65; severe exposure OR 11.78, Cl95% 2.35 to 59.09) and nasal symptoms (OR 2.01, Cl95% 0.97 to 4.15; OR 2.19, Cl95% 1.06 to 4.55) and cough (OR 1.89, Cl95% 0.61 to 5.86; OR 3.06, Cl95% 1.02 to 9.29) during the previous 12 months were increased, with a dose-response pattern.« less

Infrared spectroscopic investigations on the distribution of residual grease on textiles

NASA Astrophysics Data System (ADS)

Siedler, J.; Schumacher-Hamedat, Ursula; Hoecker, Hartwig

1992-03-01

Surface modification of textile materials is of major importance in the modern textile industry. Several methods are commonly applied to produce a broad range of coated materials. The adhesion between the coating polymers and the textile fibers often determines the quality. Improved adhesion of the coating is achieved by a chemical bonding (covalent or ionic) between the coating materials and the textile. The efficiency,however, is dependent on the orientation of the functional groups of the outmost molecular layers of the fibers. Therefore, we have used surface sensitive methods to analyze the surface structure of proteinaceous fibers. Homopoly(aminoacid) films like poly(-(gamma) -benzyl-L-glutamate) and poly(- (Beta) -benzyl-L-aspartate) have been chosen as models for natural fibers like wool.

Cross-linked chitosan aerogel modified with Au: Synthesis, characterization and catalytic application.

PubMed

Keshipour, Sajjad; Mirmasoudi, Seyyedeh Sahra

2018-09-15

Dimercaprol as the chelating agent of Au(III) was loaded on chitosan aerogel. Dimercaprol supported on chitosan aerogel efficiently was complexed with Au(III). The new organometallic compound showed good catalytic activity in the oxidation reaction of some aliphatic alcohols, benzyl alcohol, and ethylbenzene. High conversions and excellent selectivities were obtained in the solvent-free oxidation reactions under mild reaction conditions. Also, turnover numbers were calculated for the oxidation reactions with 203, 134, 308, 282, 392, and 153 for 1-pentanol, 1-octanol, 2-propanol, 2-butanol, benzyl alcohol, and ethylbenzene, respectively. The organometallic compound is applicable as a heterogeneous Au(III) catalyst with high chemical stabilityand recyclability up to 6 times. Copyright © 2018 Elsevier Ltd. All rights reserved.

Zeolite-encapsulated Co(II), Mn(II), Cu(II) and Cr(III) salen complexes as catalysts for efficient selective oxidation of benzyl alcohol

NASA Astrophysics Data System (ADS)

Li, F. H.; Bi, H.; Huang, D. X.; Zhang, M.; Song, Y. B.

2018-01-01

Co(II), Mn(II), Cu(II) and Cr(III) salen type complexes were synthesized in situ in Y zeolite by the reaction of ion-exchanged metal ions with the flexible ligand molecules that had diffused into the cavities. Data of characterization indicates the formation of metal salen complexes in the pores without affecting the zeolite framework structure, the absence of any extraneous species and the geometry of encapsulated complexes. The catalytic activity results show that Cosalcyen Y exhibited higher catalytic activity in the water phase selective oxidation of benzyl alcohol, which could be attributed to their geometry and the steric environment of the metal actives sites.

Selectivity switch for nitrogen functionalization of styrene on Au(1 1 1)

NASA Astrophysics Data System (ADS)

Deng, Xingyi; Friend, Cynthia M.

2008-03-01

Functionalization of styrene to form N-containing hydrocarbons, e.g. 2-phenylaziridine, benzonitrile, and benzyl nitrile, is achieved by reaction with adsorbed NH a and N a on Au(1 1 1). Electron-induced decomposition of condensed NH 3 was used to produce NH a, N a and H a on Au(1 1 1) at 110 K. The selectivity of the reactions is strongly dependent on the relative concentrations of the surface species. The addition of NH to styrene results in the production of 2-phenylaziridine, whereas adsorbed N and H atoms lead to the formation of nitriles benzonitrile and benzyl nitrile and, respectively, ethylbenzene. This work clearly establishes the utility of Au for promoting functionalization of olefins with nitrogen.

RIFM fragrance ingredient safety assessment, benzyl butyrate, CAS Registry Number 103-37-7.

PubMed

Api, A M; Belsito, D; Bhatia, S; Bruze, M; Calow, P; Dagli, M L; Dekant, W; Fryer, A D; Kromidas, L; La Cava, S; Lalko, J F; Lapczynski, A; Liebler, D C; Politano, V T; Ritacco, G; Salvito, D; Schultz, T W; Shen, J; Sipes, I G; Wall, B; Wilcox, D K

2016-11-01

The use of this material under current use conditions is supported by the existing information. This material was evaluated for genotoxicity, repeated dose toxicity, developmental and reproductive toxicity, local respiratory toxicity, phototoxicity/photoallergenicity, skin sensitization, as well as environmental safety. Data from the suitable read across analog benzyl acetate (CAS # 140-11-4) show that this material is not genotoxic nor does it have skin sensitization potential and also provided a MOE > 100 for the repeated dose, developmental and reproductive, and local respiratory toxicity endpoints. The phototoxicity/photoallergenicity endpoint was completed based on suitable UV spectra. The environmental endpoint was completed as described in the RIFM Framework. Copyright © 2016 Elsevier Ltd. All rights reserved.

Structures and antiviral activities of butyrolactone derivatives isolated from Aspergillus terreus MXH-23

NASA Astrophysics Data System (ADS)

Ma, Xinhua; Zhu, Tianjiao; Gu, Qianqun; Xi, Rui; Wang, Wei; Li, Dehai

2014-12-01

A new butyrolactone derivative, namely butyrolactone VIII ( 1), and six known butyrolactones ( 2-7) were separated from the ethyl acetate (EtOAc) extract of the fermentation broth of a fungus, Aspergillus terreus MXH-23. The chemical structures of these metabolites were identified by analyzing their nuclear magnetic resonance (NMR) and mass spectrometry (MS). Known butyrolactone derivatives contain an α, β-unsaturated γ-lactone ring with α-hydroxyl and γ-benzyl, and butyrolactone VIII ( 1) was the first butyrolactones contains α-benzyl and γ-hydroxyl on α, β-unsaturated lactone ring. All of the butyrolactone derivatives were tested for their anti-influenza (H1N1) effects. Derivatives 4 and 7 showed moderate antiviral activities while the newly-identified, derivative 1, did not.

NMR and X-ray structural characterization and conformational aspects of fluorinated (5Z)-3-benzil-5-arylidenofuran-2(5H)-ones

NASA Astrophysics Data System (ADS)

Teixeira, R. R.; Barbosa, L. C. A.; Kabeshov, M. A.; Maltha, C. R. A.; Corrêa, R. S.; Doriguetto, A. C.

2014-10-01

Herein we describe structural insights of (5Z)-3-benzyl-5-(2-fluorobenzylidene)furan-2(5H)-one (6) and (5Z)-3-benzyl-5-(pentafluorobenzylidene)furan-2(5H)-one (7), γ-alkylidenebutenolides analogues of the natural products nostoclides. Their structures were investigated by NMR spectroscopy and X-ray crystallography. The stereochemistry of the exocyclic double bond of these fluorinated compounds was determined to be Z by NMR analysis and confirmed by X-ray data. Compounds 6 and 7 crystallized in the monoclinic crystal system P21/c group. A comparison between structural features of (6) and (7) and nostoclide derivatives previously published by us is described.

Diastereoisomers of 2-benzyl-2, 3-dihydro-2-(1H-inden-2-yl)-1H-inden-1-ol: potential anti-inflammatory agents.

PubMed

Sheridan, Helen; Walsh, John J; Cogan, Carina; Jordan, Michael; McCabe, Tom; Passante, Egle; Frankish, Neil H

2009-10-15

The synthesis and biological activity of the novel diastereoisomers of 2-benzyl-2,3-dihydro-2-(1H-inden-2-yl)-1H-inden-1-ol is reported. The 2,2-coupled indane dimers were synthesised by coupling of the silyl enol ether of 1-indanone with the dimethyl ketal of 2-indanone. The coupled product was directly alkylated to give the racemic ketone which was reduced to the diastereoisomeric alcohols. The alcohols were separated and their relative stereochemistry was established by X-ray crystallography. These molecules demonstrate significant anti-inflammatory activity in vivo and in vitro and may represent a new class of anti-inflammatory agent.

Mollebenzylanols A and B, Highly Modified and Functionalized Diterpenoids with a 9-Benzyl-8,10-dioxatricyclo[5.2.1.01,5]decane Core from Rhododendron molle.

PubMed

Zhou, Junfei; Liu, Junjun; Dang, Ting; Zhou, Haofeng; Zhang, Hanqi; Yao, Guangmin

2018-04-06

Two highly modified and functionalized diterpenoids, mollebenzylanols A (1) and B (2), and a known grayanane diterpenoid rhodojaponin III (3) were isolated from Rhododendron molle. Their structures were determined by spectroscopic data analysis, an electronic circular dichroism (ECD) exciton chirality method, ECD calculations, and X-ray diffraction analysis of the p-bromobenzoate ester of 1 (1a). Compounds 1 and 2 possess an unprecedented diterpene carbon skeleton featuring a unique 9-benzyl-8,10-dioxatricyclo[5.2.1.0 1,5 ]decane core, and their plausible biosynthetic pathways are proposed. Their PTP1B inhibitory activity and modes of action were investigated.

Structure of HIV-1 nonnucleoside reverse transcriptase inhibitors derivatives of N-benzyl-benzimidazole with different substituents in position 4

NASA Astrophysics Data System (ADS)

Ziółkowska, Natasza E.; Michejda, Christopher J.; Bujacz, Grzegorz D.

2010-01-01

The constant development of new drugs against HIV-1 is necessary due to global expansion of AIDS and HIV-1 drug resistance. Nonnucleoside reverse transcriptase inhibitors of HIV-1 (NNRTIs) are potentially effective and nontoxic drugs in AIDS therapy. The crystal structures of six nonnucleoside inhibitors of HIV-1 reverse transcriptase (RT) derivatives of N-benzyl-benzimidazole are reported here. The investigated compounds belong to the group of so called "butterfly like" inhibitors with characteristic two π-electron moieties with an angled orientation. The structural data show the influence of the substituents of the benzimidazole ring on the geometry of the molecule and correlation between the structure of the inhibitor and its biological activity.

40 CFR 469.22 - Specialized definitions.

Code of Federal Regulations, 2010 CFR

2010-07-01

... trichloroethylene 2 Chlorophenol 2,4 Dichlorophenol 4 Nitrophenol pentachlorophenol di-n-butyl phthalate anthracene 1,2 Diphenylhydrazine isophorone butyl benzyl pthalate 1,1 Dichloroethylene 2,4,6 Trichlorophenol...

40 CFR 469.22 - Specialized definitions.

Code of Federal Regulations, 2011 CFR

2011-07-01

... trichloroethylene 2 Chlorophenol 2,4 Dichlorophenol 4 Nitrophenol pentachlorophenol di-n-butyl phthalate anthracene 1,2 Diphenylhydrazine isophorone butyl benzyl pthalate 1,1 Dichloroethylene 2,4,6 Trichlorophenol...

40 CFR 433.11 - Specialized definitions.

Code of Federal Regulations, 2011 CFR

2011-07-01

...-propylamine Pentachlorophenol Phenol Bis (2-ethylhexyl) phthalate Butyl benzyl phthalate Di-n-butyl phthalate Di-n-octyl phthalate Diethyl phthalate Dimethyl phthalate 1,2-Benzanthracene (benzo(a)anthracene...

40 CFR 433.11 - Specialized definitions.

Code of Federal Regulations, 2012 CFR

2012-07-01

...-propylamine Pentachlorophenol Phenol Bis (2-ethylhexyl) phthalate Butyl benzyl phthalate Di-n-butyl phthalate Di-n-octyl phthalate Diethyl phthalate Dimethyl phthalate 1,2-Benzanthracene (benzo(a)anthracene...

40 CFR 433.11 - Specialized definitions.

Code of Federal Regulations, 2014 CFR

2014-07-01

...-propylamine Pentachlorophenol Phenol Bis (2-ethylhexyl) phthalate Butyl benzyl phthalate Di-n-butyl phthalate Di-n-octyl phthalate Diethyl phthalate Dimethyl phthalate 1,2-Benzanthracene (benzo(a)anthracene...

Synthesis and Structure–Activity Relationships of N-Benzyl Phenethylamines as 5-HT2A/2C Agonists

PubMed Central

2014-01-01

N-Benzyl substitution of 5-HT2A receptor agonists of the phenethylamine structural class of psychedelics (such as 4-bromo-2,5-dimethoxyphenethylamine, often referred to as 2C-B) confer a significant increase in binding affinity as well as functional activity of the receptor. We have prepared a series of 48 compounds with structural variations in both the phenethylamine and N-benzyl part of the molecule to determine the effects on receptor binding affinity and functional activity at 5-HT2A and 5-HT2C receptors. The compounds generally had high affinity for the 5-HT2A receptor with 8b having the highest affinity at 0.29 nM but with several other compounds also exhibiting subnanomolar binding affinities. The functional activity of the compounds was distributed over a wider range with 1b being the most potent at 0.074 nM. Most of the compounds exhibited low to moderate selectivity (1- to 40-fold) for the 5-HT2A receptor in the binding assays, although one compound 6b showed an impressive 100-fold selectivity for the 5-HT2A receptor. In the functional assay, selectivity was generally higher with 1b being more than 400-fold selective for the 5-HT2A receptor. PMID:24397362

Synthesis and structure-activity relationships of N-benzyl phenethylamines as 5-HT2A/2C agonists.

PubMed

Hansen, Martin; Phonekeo, Karina; Paine, James S; Leth-Petersen, Sebastian; Begtrup, Mikael; Bräuner-Osborne, Hans; Kristensen, Jesper L

2014-03-19

N-Benzyl substitution of 5-HT2A receptor agonists of the phenethylamine structural class of psychedelics (such as 4-bromo-2,5-dimethoxyphenethylamine, often referred to as 2C-B) confer a significant increase in binding affinity as well as functional activity of the receptor. We have prepared a series of 48 compounds with structural variations in both the phenethylamine and N-benzyl part of the molecule to determine the effects on receptor binding affinity and functional activity at 5-HT2A and 5-HT2C receptors. The compounds generally had high affinity for the 5-HT2A receptor with 8b having the highest affinity at 0.29 nM but with several other compounds also exhibiting subnanomolar binding affinities. The functional activity of the compounds was distributed over a wider range with 1b being the most potent at 0.074 nM. Most of the compounds exhibited low to moderate selectivity (1- to 40-fold) for the 5-HT2A receptor in the binding assays, although one compound 6b showed an impressive 100-fold selectivity for the 5-HT2A receptor. In the functional assay, selectivity was generally higher with 1b being more than 400-fold selective for the 5-HT2A receptor.

In situ characterization of N-carboxy anhydride polymerization in nanoporous anodic alumina.

PubMed

Lau, K H Aaron; Duran, Hatice; Knoll, Wolfgang

2009-03-12

Poly(gamma-benzyl-L-glutamate) (PBLG) has been a popular model polypeptide for a range of physicochemical studies, and its modifiable ester side chains make it an attractive platform for various potential applications. Thin films of Poly(gamma-benzyl-L-glutamate) PBLG were surface grafted within nanoporous anodic alumina (AAO) by surface-initiated polymerization of the N-carboxy anhydride of benzyl-L-glutamate (BLG-NCA). The grafting process was characterized by optical waveguide spectroscopy (OWS), infrared spectroscopy (FT-IR), and scanning electron microscopy (SEM). OWS was able to track the PBLG layer thickness increase in situ, and ex situ FT-IR gave complementary information on the PBLG chain's secondary structure. Transitions in the PBLG growth rate could be correlated with transitions in the polypeptide secondary structure. The emergence of a three-dimensional, anisotropic PBLG morphology within the cylindrical pores of the AAO membrane was also identified as the grafted PBLG average layer thickness increased. Comparison of the PBLG/AAO results with those on a planar silicon dioxide surface indicated that both the conformational transitions and the PBLG nanostructure development could be attributed to the confining geometry within the pores of the nanoporous AAO matrix. The use of a nanoporous AAO matrix, combined with the surface grafting of a thin film of PBLG chains with multiple modifiable side chains, could potentially offer a nanoporous platform with a very high density of functional sites.

Structure-activity relationship study and optimisation of 2-aminopyrrole-1-benzyl-4,5-diphenyl-1H-pyrrole-3-carbonitrile as a broad spectrum metallo-β-lactamase inhibitor.

PubMed

McGeary, Ross P; Tan, Daniel T C; Selleck, Christopher; Monteiro Pedroso, Marcelo; Sidjabat, Hanna E; Schenk, Gerhard

2017-09-08

A SAR study on derivatives of 2-amino-1-benzyl-4,5-diphenyl-1H-pyrrole-3-carbonitrile 5a revealed that the 3-carbonitrile group, vicinal 4,5-diphenyl and N-benzyl side chains of the pyrrole are important for the inhibitory potencies of these compounds against members representing the three main subclasses of metallo-β-lactamases (MBLs), i.e. IMP-1 (representing the B1 subgroup), CphA (B2) and AIM-1 (B3). Coupling of 5a with a series of acyl chlorides and anhydrides led to the discovery of two N-acylamide derivatives, 10 and 11, as the two most potent IMP-1 inhibitors in this series. However, these compounds are less effective towards CphA and AIM-1. The N-benzoyl derivative of 5a retained potent in vitro activity against each of MBLs tested (with inhibition constants in the low μM range). Importantly, this compound also significantly enhanced the sensitivity of IMP-1, CphA- or AIM-1-producing cell cultures towards meropenem. This compound presents a promising starting point for the development of a universal MBL inhibitor, targeting members of each of the major subgroups of this family of enzymes. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Benzyl alcohol and block copolymer micellar lithography: a versatile route to assembling gold and in situ generated titania nanoparticles into uniform binary nanoarrays.

PubMed

Polleux, Julien; Rasp, Matthias; Louban, Ilia; Plath, Nicole; Feldhoff, Armin; Spatz, Joachim P

2011-08-23

Simultaneous synthesis and assembly of nanoparticles that exhibit unique physicochemical properties are critically important for designing new functional devices at the macroscopic scale. In the present study, we report a simple version of block copolymer micellar lithography (BCML) to synthesize gold and titanium dioxide (TiO(2)) nanoarrays by using benzyl alcohol (BnOH) as a solvent. In contrast to toluene, BnOH can lead to the formation of various gold nanopatterns via salt-induced micellization of polystyrene-block-poly(vinylpyridine) (PS-b-P2VP). In the case of titania, the use of BCML with a nonaqueous sol-gel method, the "benzyl alcohol route", enables the fabrication of nanopatterns made of quasi-hexagonally organized particles or parallel wires upon aging a (BnOH-TiCl(4)-PS(846)-b-P2VP(171))-containing solution for four weeks to grow TiO(2) building blocks in situ. This approach was found to depend mainly on the relative lengths of the polymer blocks, which allows nanoparticle-induced micellization and self-assembly during solvent evaporation. Moreover, this versatile route enables the design of uniform and quasi-ordered gold-TiO(2) binary nanoarrays with a precise particle density due to the absence of graphoepitaxy during the deposition of TiO(2) onto gold nanopatterns. © 2011 American Chemical Society

Synthesis of polymers containing 3-hydroxypyridin-4-one bidentate ligands for treatment of iron overload

PubMed Central

Saghaie, Lotfollah; Liu, Dy; Hider, Robert C

2015-01-01

Iron overload is a clinical problem which can be prevented by using iron chelating agents. An alternative method of relieving iron overload is to reduce iron absorption from the intestine by administering specific iron chelating agents, which can bind iron to form nonabsorbable complexes. Based on this strategy, a series of polymeric ligands containing the chelating moiety 3-hydroxypyridin-4-ones (HPOs) were synthesized. The synthetic route involves the benzylation of hydroxyl group of (2-methyl-3-hydroxypyran-4-one (maltol) and conversion of benzylated maltol to 3-benzyloxypyridin-4-one derivatives by using three suitable primary amines (2,6-diaminohexanoic acid (lysine) and 1,6-diaminohexane and 5-aminopentanol). The resulted compounds incorporated into polymer by copolymerization with acryloyl chloride using 2, 2’-azobisisobutyronitrile (AIBN) as the initiator. Finally, the benzyl groups of polymers were removed by catalytic hydrogenation (Pd/C). In this work, three final polymers of HPO derivatives namely poly-2-propylamido-6-(3- hydroxy -1,4-dihydro-2-methy-4-oxopyrid-1-yl) hexanoic acid, 6-(3-hydroxy-1, 4-dihydro-2-methyl-4-oxopyrid-1-yl) hexyl-1-polypropylamide and 5-(3-hydroxy-1-,4-dihydro-2-methyl-4-oxopyrid-1-yl)-1-polyacrylate pentane were synthesized. Identification and structural elucidation of compounds were achieved by proton nuclear magnetic resonance (1H NMR), carbon nuclear magnetic resonance (13C NMR) and infrared (IR) spectroscopy. PMID:26600863

Evaluation of Antitrypanosomal Dihydroquinolines for Hepatotoxicity, Mutagenicity, and Methemoglobin Formation In Vitro

PubMed Central

Werbovetz, Karl A.; Riccio, Edward S.; Furimsky, Anna; Richard, Julian V.; He, Shanshan; Iyer, Lalitha; Mirsalis, Jon

2014-01-01

N 1-benzylated dihydroquinolin-6-ols and their corresponding esters display exceptional activity against African trypanosomes in vitro, and administration of members of this class of compounds to trypanosome-infected mice results in cures in a first stage African trypanosomiasis model. Since a quinone imine intermediate has been implicated in the antiparasitic mechanism of action of these compounds, evaluation of the hepatotoxic, mutagenic, and methemoglobin-promoting effects of these agents was performed. 1-Benzyl-1,2-dihydro-2,2,4-trimethylquinolin-6-ol hydrochloride (OSU-36.HCl) and 1-benzyl-1,2-dihydro-2,2,4-trimethylquinolin-6-yl acetate (OSU-40) showed outstanding in vitro selectivity for T. brucei compared to the HepG2, Hep3B, Huh7 and PLC5 hepatocyte cell lines. OSU-36.HCl and 1-(2-methoxybenzyl)-1,2-dihydro-2,2,4-trimethylquinolin-6-yl acetate (OSU-75) were not mutagenic when screened in the Ames assay, with or without metabolic activation. The latter two compounds promoted time- and dose-dependent formation of methemoglobin when incubated in whole human blood, but such levels were below those typically required to produce symptoms of methemoglobinemia in humans. While compounds capable of quinone imine formation require careful evaluation, these in vitro studies indicate that antitrypanosomal dihydroquinolines merit further study as drug candidates against the neglected tropical disease human African trypanosomiasis. PMID:24819520

Synthesis, crystal structure determination, biological screening and docking studies of N1-substituted derivatives of 2,3-dihydroquinazolin-4(1H)-one as inhibitors of cholinesterases.

PubMed

Sultana, Nargis; Sarfraz, Muhammad; Tanoli, Saba Tahir; Akram, Muhammad Safwan; Sadiq, Abdul; Rashid, Umer; Tariq, Muhammad Ilyas

2017-06-01

Pursuing the strategy of developing potent AChE inhibitors, we attempted to carry out the N 1 -substitution of 2,3-dihydroquinazolin-4(1H)-one core. A set of 32 N-alkylated/benzylated quinazoline derivatives were synthesized, characterized and evaluated for their inhibition against cholinesterases. N-alkylation of the series of the compounds reported previously (N-unsubstituted) resulted in improved activity. All the compounds showed inhibition of both enzymes in the micromolar to submicromolar range. Structure activity relationship (SAR) of the 32 derivatives showed that N-benzylated compounds possess good activity than N-alkylated compounds. N-benzylated compounds 2ad and 2af were found very active with their IC 50 values toward AChE in submicromolar range (0.8µM and 0.6µM respectively). Binding modes of the synthesized compounds were explored by using GOLD (Genetic Optimization for Ligand Docking) suit v5.4.1. Computational predictions of ADMET studies reveal that all the compounds have good pharmacokinetic properties with no AMES toxicity and carcinogenicity. Moreover, all the compounds are predicted to be absorbed in human intestine and also have the ability to cross blood brain barrier. Overall, the synthesized compounds have established a structural foundation for the design of new inhibitors of cholinesterase. Copyright © 2017 Elsevier Inc. All rights reserved.

A simple spectrophotometric method for the determination of trace levels of molybdenum using N,N'-bis(2-hydroxy-5-bromo-benzyl)1,2 diaminopropane.

PubMed

Kara, Derya; Karadaş, Cennet

2015-08-05

The present work describes a selective, rapid and economical spectrophotometric method for the determination of molybdenum using N,N'-bis(2-hydroxy-5-bromo-benzyl)1,2 diaminopropane. Molybdenum(VI) reacts with N,N'-bis(2-hydroxy-5-bromo-benzyl)1,2 diaminopropane to form a stable 1:1 yellow complex with an absorption maximum at 342 nm. The reaction is completed within 10 min and the absorbance of the molybdenum complex remains stable for at least 1 week at room temperature. The effective molar absorption coefficient at 342 nm was 9.6 × 10(3)L mol(-1)cm(-1). Under optimal conditions, the complex obeys Beer's law from 0 to 9.9 μg mL(-1). The relative standard deviation was 0.08% (for 11 samples, each containing 6 μg mL(-1) molybdenum). Under the optimum conditions, the detection limit (3σ) was 17.7 μg L(-1) for molybdenum without any preconcentration. The precision was determined from 30 results obtained for 4.80 μg mL(-1) Mo(VI); the mean value of a molybdenum(VI) was 4.83 μg ml(-1) with a standard derivation of 0.002 μg ml(-1) molybdenum(VI). Copyright © 2015 Elsevier B.V. All rights reserved.

40 CFR 413.02 - General definitions.

Code of Federal Regulations, 2014 CFR

2014-07-01

...-nitrosodiphenylamine N-nitrosodi-n-propylamine Pentachlorophenol Phenol Bis (2-ethylhexyl) phthalate Butyl benzyl phthalate Di-n-butyl phthalate Di-n-octyl phthalate Diethyl phthalate Dimethyl phthalate 1,2-benzanthracene...

40 CFR 413.02 - General definitions.

Code of Federal Regulations, 2012 CFR

2012-07-01

...-nitrosodiphenylamine N-nitrosodi-n-propylamine Pentachlorophenol Phenol Bis (2-ethylhexyl) phthalate Butyl benzyl phthalate Di-n-butyl phthalate Di-n-octyl phthalate Diethyl phthalate Dimethyl phthalate 1,2-benzanthracene...

Auger analysis of oxygen and sulfur interactions with various metals and the effect of sliding on these interactions

NASA Technical Reports Server (NTRS)

Buckley, D. H.

1973-01-01

Various gases were adsorbed to copper, aluminum, and chromium surfaces. The gases included oxygen, hydrogen sulfide, methyl mercaptan, and sulfur dioxide. Chemisorption was conducted on static surfaces and during dynamic friction experiments. An Auger cyclindrical mirror analyzer was used to monitor surface films. The sulfur containing gases adsorbed readily to all surfaces. Exposures of as little as 0.000001 (torr)(sec) (1 langmuir) were sufficient to reduce friction. Sliding contact did not affect chemisorption of copper or aluminum but did affect chemisorption to chromium surfaces. Oxygen removed sulfur films from all surfaces at room temperature (23 C). Gaseous exposures were from 0.000001 to 0.01 (torr)(sec) (1 to 10,000 langmuirs).

40 CFR Table 2 to Subpart Ggg of... - Partially Soluble HAP

Code of Federal Regulations, 2012 CFR

2012-07-01

... Trichloroethylene Chloroethane (ethyl chloride) Trimethylpentane Vinyl acetate Xylene (p) Vinyl chloride N-hexane... Methylene chloride Allyl chloride N,N-dimethylaniline Benzene Propionaldehyde Benzyl chloride Propylene...

40 CFR Table 2 to Subpart Ggg of... - Partially Soluble HAP

Code of Federal Regulations, 2011 CFR

2011-07-01

... Trichloroethylene Chloroethane (ethyl chloride) Trimethylpentane Vinyl acetate Xylene (p) Vinyl chloride N-hexane... Methylene chloride Allyl chloride N,N-dimethylaniline Benzene Propionaldehyde Benzyl chloride Propylene...

40 CFR Table 2 to Subpart Ggg of... - Partially Soluble HAP

Code of Federal Regulations, 2010 CFR

2010-07-01

... Trichloroethylene Chloroethane (ethyl chloride) Trimethylpentane Vinyl acetate Xylene (p) Vinyl chloride N-hexane... Methylene chloride Allyl chloride N,N-dimethylaniline Benzene Propionaldehyde Benzyl chloride Propylene...

A Feasible One-Step Synthesis of Hierarchical Zeolite Beta with Uniform Nanocrystals via CTAB

PubMed Central

Zhang, Weimin; Hu, Sufang; Qin, Bo; Li, Ruifeng

2018-01-01

A hierarchical zeolite Beta has been prepared by a feasible one-pot and one-step method, which is suitable for application in industrial production. The synthesis is a simple hydrothermal process with low-cost raw materials, without adding alcohol or adding seeds, and without aging, recrystallization, and other complex steps. The hierarchical zeolite Beta is a uniform nanocrystal (20–50 nm) aggregation with high external surface area (300 m2/g) and mesoporous volume (0.50 cm3/g), with the mesoporous structure composed of intercrystal and intracrystal pores. As an acid catalyst in benzylation of naphthalene with benzyl chloride, the hierarchical zeolite Beta has shown high activity in the bulky molecule reaction due to its introduction of mesostructure. PMID:29695044

Effect of benzyl amino purine and indole-3-acetic acid on propagation of Sterculia foetida in vitro

NASA Astrophysics Data System (ADS)

Yuniastuti, E.; Widodo, C. E.; Samanhudi; Delfianti, M. N. I.

2018-03-01

Sterculia foetida is an oval seed plants that can be used as biofuel, which is one of the environmental friendly fuels. This plant is quite hard to find because not many peoples cultivate the plants. An in vitro propagation is one way to preserve the plant. This research aimed to determine optimum concentration of benzyl amino purine (BAP) and indole-3-acetic acid (IAA) to propagate S. foetida in vitro. The results showed that woody plant medium (WPM) added by 4 mg L BAP-1 and 0.5 mg L IAA-1 was able to produce complete plantlet, whereas those added by 4 mg L BAP-1 and 1 mg L IAA-1 generated the best growth of shoot and leaves.

Discovery of (+)-N-(3-aminopropyl)-N-[1-(5-benzyl-3-methyl-4-oxo-[1,2]thiazolo[5,4-d]pyrimidin-6-yl)-2-methylpropyl]-4-methylbenzamide (AZD4877), a kinesin spindle protein inhibitor and potential anticancer agent.

PubMed

Theoclitou, Maria-Elena; Aquila, Brian; Block, Michael H; Brassil, Patrick J; Castriotta, Lillian; Code, Erin; Collins, Michael P; Davies, Audrey M; Deegan, Tracy; Ezhuthachan, Jayachandran; Filla, Sandra; Freed, Ellen; Hu, Haiqing; Huszar, Dennis; Jayaraman, Muthusamy; Lawson, Deborah; Lewis, Paula M; Nadella, Murali V P; Oza, Vibha; Padmanilayam, Maniyan; Pontz, Timothy; Ronco, Lucienne; Russell, Daniel; Whitston, David; Zheng, Xiaolan

2011-10-13

Structure-activity relationship analysis identified (+)-N-(3-aminopropyl)-N-[1-(5-benzyl-3-methyl-4-oxo-[1,2]thiazolo[5,4-d]pyrimidin-6-yl)-2-methylpropyl]-4-methylbenzamide (AZD4877), from a series of novel kinesin spindle protein (KSP) inhibitors, as exhibiting both excellent biochemical potency and pharmaceutical properties suitable for clinical development. The selected compound arrested cells in mitosis leading to the formation of the monopolar spindle phenotype characteristic of KSP inhibition and induction of cellular death. A favorable pharmacokinetic profile and notable in vivo efficacy supported the selection of this compound as a clinical candidate for the treatment of cancer.

A review of new developments in the Friedel–Crafts alkylation – From green chemistry to asymmetric catalysis

PubMed Central

2010-01-01

Summary The development of efficient Friedel–Crafts alkylations of arenes and heteroarenes using only catalytic amounts of a Lewis acid has gained much attention over the last decade. The new catalytic approaches described in this review are favoured over classical Friedel–Crafts conditions as benzyl-, propargyl- and allyl alcohols, or styrenes, can be used instead of toxic benzyl halides. Additionally, only low catalyst loadings are needed to provide a wide range of products. Following a short introduction about the origin and classical definition of the Friedel–Crafts reaction, the review will describe the different environmentally benign substrates which can be applied today as an approach towards greener processes. Additionally, the first diastereoselective and enantioselective Friedel–Crafts-type alkylations will be highlighted. PMID:20485588

Antidepressent Effect of Two New Benzyl Derivatives from Wild Strawberry Fragaria vesca var. nubicola Lindl. ex Hook.f.

PubMed

Naz, Sadia; Farooq, Umar; Khan, Ajmal; Khan, Haroon; Karim, Nasiara; Sarwar, Rizwana; Hussain, Javid; Rauf, Abdur

2017-01-01

Two new benzyl derivatives were isolated from ethyl acetate fraction of wild strawberry, Fragaria vesca var. nubicola Lindl. ex Hook.f. The structures of these compounds were elucidated to be 5-(4-hydroxy-3-methoxyphenethyl)-7-methoxy-2H-chromen-3-ol ( 1 ) and 5-(4-hydroxy-3-methoxyphenethyl)-4,7-dimethoxy-2H-chromen-3-ol ( 2 ) based on spectroscopic data through IR, UV, 1 H-NMR, 13 C-NMR along with two dimensional (2D) techniques HMBC, HMQC, and COSY. Both compounds 1 and 2 were studied in tail suspension and forced swim tests for antidepressant like effects. A significant dose dependent antidepressant like effect was observed by causing spontaneous anti-immobility at various test doses upon intraperitoneal administration.

RIFM fragrance ingredient safety assessment, p-Isopropylbenzyl acetate, CAS Registry Number 59230-57-8.

PubMed

Api, A M; Belsito, D; Bhatia, S; Bruze, M; Calow, P; Dagli, M L; Dekant, W; Fryer, A D; Kromidas, L; La Cava, S; Lalko, J F; Lapczynski, A; Liebler, D C; Politano, V T; Ritacco, G; Salvito, D; Schultz, T W; Shen, J; Sipes, I G; Wall, B; Wilcox, D K

2016-11-01

The use of this material under current use conditions is supported by the existing information. This material was evaluated for genotoxicity, repeated dose toxicity, developmental toxicity, reproductive toxicity, local respiratory toxicity, phototoxicity, skin sensitization, as well as environmental safety. Data from the suitable read across analog, benzyl acetate (CAS # 140-11-4), show that this material is not genotoxic nor does it have skin sensitization potential. The repeated dose, developmental and reproductive, and local respiratory toxicity endpoints were completed using benzyl acetate (CAS # 140-11-4) as a suitable read across analog, which provided a MOE > 100. The phototoxicity/photoallergenicity endpoint was completed based on suitable UV spectra. The environmental endpoint was completed as described in the RIFM Framework. Copyright © 2016 Elsevier Ltd. All rights reserved.

Meyer-Overton reforged: The origins of alcohol and anesthetic potency in membranes as determined by a new NMR partitioning probe, benzyl alcohol

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

Janes, N.; Ma, L.; Hsu, J.W.

1992-01-01

The Meyer-Overton hypothesis--that anesthesia arises from the nonspecific action of solutes on membrane lipids--is reformulated using colligative thermodynamics. Configurational entropy, the randomness imparted by the solute through the partitioning process, is implicated as the energetic driving force that pertubs cooperative membrane equilibria. A proton NMR partitioning approach based on the anesthetic benzyl alcohol is developed to assess the reformulation. Ring resonances from the partitioned drug are shielded by 0.2 ppm and resolved from the free, aqueous drug. Free alcohol is quantitated in dilute lipid dispersions using an acetate internal standard. Cooperative equilibria in model dipalmitoyl lecithin membranes are examined withmore » changes in temperature and alcohol concentration. The L[sub [beta][prime

Enhanced Activity of Au/NiO Nanohybrids for the Reductive Amination of Benzyl Alcohol

PubMed Central

Chinchilla, Lidia E.; Sanchez Trujillo, Felipe Juan; Dimitratos, Nikolaos; Botton, Gianluigi A.

2017-01-01

Gold nanoparticles were prepared by sol immobilization (AuSI) or deposition precipitation (AuDP), then deposited on NiO and commercial TiO2 (P25). The Au/NiO catalysts showed higher activity and yield to the secondary amine, compared to Au/TiO2 catalysts, when tested for the reductive amination of benzyl alcohol with isopropylamine. We attribute this result to a synergistic effect between Au and NiO. Moreover, as a result of the protective effect of the polyvinyl alcohol used in the sol immobilization synthesis, the gold nanoparticles on NiO demonstrate an increased resistance to structural changes during the reaction. This effect results in enhanced catalytic efficiency in terms of activity, and better stability against deactivation. PMID:29258170

Removal of the endocrine disrupter butyl benzyl phthalate from the environment

PubMed Central

Karlovsky, Petr

2010-01-01

Butyl benzyl phthalate (BBP), an aryl alkyl ester of 1,2-benzene dicarboxylic acid, is extensively used in vinyl tiles and as a plasticizer in PVC in many commonly used products. BBP, which readily leaches from these products, is one of the most important environmental contaminants, and the increased awareness of its adverse effects on human health has led to a dramatic increase in research aimed at removing BBP from the environment via bioremediation. This review highlights recent progress in the degradation of BBP by pure and mixed bacterial cultures, fungi, and in sludge, sediment, and wastewater. Sonochemical degradation, a unique abiotic remediation technique, and photocatalytic degradation are also discussed. The degradation pathways for BBP are described, and future research directions are considered. PMID:20396882

Reactions of Charged Substrates. 5. The Solvolysis and Sodium Azide Substitution Reactions of Benzylpyridinium Ions in Deuterium Oxide.

PubMed

Buckley, Neil; Oppenheimer, Norman J.

1996-10-18

Second-order rate constants and activation values were measured for the reactions with NaN(3) of a series of 4-Y-substituted (Y = MeO, Me, H, Cl, and NO(2)) benzyl 3'-Z-substituted (Z = CN, CONH(2), H, F, Ac) pyridinium chlorides in deuterium oxide. 3'-Cyanopyridine substrates reacted much faster than nicotinamide and pyridine substrates; in the pyridine series the 4-Me, 4-H, and 4-Cl benzyl analogs did not react for up to 6 months at 96()() degrees C in 1.7 M NaN(3). The 3'-cyanopyridine substrates do not exhibit borderline kinetic behavior, but the nicotinamide substrates do. The Hammett plot is flat for the NaN(3) reaction of 3'-cyanopyridine substrates and increasingly V-shaped for the nicotinamide and pyridine substrates. The values of beta(LG) (four-point plot) for the NaN(3) reaction of the 4-MeO benzyl substrates is -1.45, which is usually interpreted as being a very "late" activated complex. Two-point Brønsted "plots" for the other benzyl derivatives and for two N-methylpyridinium ions give values of beta(LG) in the same range. The second-order rate constant and activation values for N-methyl-3'-cyanopyridinium iodide are within the same range as those for the benzyl substrates. For the hydrolysis reaction, the Hammett plot is linear for 3'-cyanopyridine substrates (rho(+) = -1.24) and flat for the nicotinamide substrates. The extent of hydrolysis of 0.005-0.05 M solutions of the 3'-cyanopyridinie substrates depended on the initial concentration of substrate, and hydrolysis was slowed significantly or stopped completely in the presence of exogenous 3-cyanopyridine. These results show that an equilibrium is established among the products for the 4-MeO, 4-Me, 4-H, and 4-Cl substrates; the 4-NO(2) substrate reacted too slowly to discern any difference. Data for the extent of hydrolysis were fitted by an equation derived assuming the equilibrium. Despite this limitation on a classic test of mechanism, the rates and rho values are consistent with direct displacement by solvent and not with a unimolecular process. These results, which are rationalized in terms of the Pross-Shaik model, suggest that there are no ion-dipole complex intermediates in the benzyl series and show that borderline kinetic behavior is a function of leaving group ability and is not necessarily related to a change in mechanism. A computational approach was used to evaluate anomalous beta(LG) values for the hydrolysis and nucleophilic substitution reactions of the methypyridinium ion substrates. It was found that neither the Nu-substrate bond lengths nor the difference in charge matched the beta(LG) values. The value of DeltaDeltaS() of -15 gibbs/mol between (4-methoxybenzyl)-3'-cyanopyridinium chloride and the corresponding dimethylsulfonium chloride in the NaN(3) reaction, which is the result of the solvation of the pyridine at the transition state and the lack of solvation of SMe(2), is used to argue that the source of NAD(+) glycohydrolase "catalysis" of NAD(+) bond cleavage is the result of desolvation of the leaving group upon binding.

21 CFR 177.1590 - Polyester elastomers.

Code of Federal Regulations, 2012 CFR

2012-04-01

... dimethyl isophthalate—is made to react with alpha-hydroomega-hydroxypoly (oxytetramethylene) and/or 1,4... substances Limitations 4,4′ - Bis (alpha, alpha-dimethyl-benzyl) diphenylamine For use only as an antioxidant...

21 CFR 177.1590 - Polyester elastomers.

Code of Federal Regulations, 2013 CFR

2013-04-01

... dimethyl isophthalate—is made to react with alpha-hydroomega-hydroxypoly (oxytetramethylene) and/or 1,4... substances Limitations 4,4′ - Bis (alpha, alpha-dimethyl-benzyl) diphenylamine For use only as an antioxidant...

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

Efficacy and tolerability of a new synergized pyrethrins thermofobic foam in comparison with benzyl benzoate in the treatment of scabies in convicts: the ISAC study (Studio Della scabbia in ambiente carcerario).

PubMed

Biele, M; Campori, G; Colombo, R; De Giorgio, G; Frascione, P; Sali, R; Starnini, G; Milani, M

2006-07-01

Scabies is a very common skin infection in convicts. The SIMSPE Society (Società Italiana di Medicina e Sanità Penitenziaria) has organized and conducted a multicentre, randomized, comparative, parallel group, investigator-blinded trial to evaluate the efficacy and tolerability of synergized pyrethrins foam (PF) in comparison with benzyl benzoate (BB) lotion. A total of 240 convicted patients, enrolled in eight National Jail Institutions, with a clinical diagnosis of scabies, were treated with PF (n = 120) for three consecutive days or BB (n = 120) for five consecutive days. Primary study endpoints were the clinical cure rate and the local tolerability. Secondary endpoints were clinical evolution of scabietic lesions and itching intensity. Study outcomes were assessed using appropriate semiquantitative scores at baseline and after 2 and 4 weeks. A second treatment cycle was applied if after 2 weeks the patient was not judged clinically cured. At week 2, a total of 75% (95% CI: 66-82%) and 71% (95% CI: 62-78%) of patients showed a complete clinical cure rate in the PF and BB groups, respectively. At week 4, the percentage of totally cured patients increased up to 95% (95% CI: 89-97%) and 91% (95% CI: 83-94%) in the PF and BB groups, respectively (P = NS between groups). At week 4, 5% in the PF group and 9% in the BB group complained of itching. Burning and irritation after treatment applications were more common in the BB group in comparison with the PF group. The tolerability score was better in the PF group in comparison with to BB group (2.9 vs. 2.2; P = 0.0001). A total of 95% of patients in the PV group had a good tolerability score (i.e. = 3) in comparison with 41% in the BB group. Our results show that a 3-day treatment with pyrethrins thermofobic foam is at least as effective as a 5-day treatment with benzyl benzoate lotion in convicted subjects with scabies. The foam formulation is better tolerated than the benzyl benzoate lotion.

Conjugation of Benzylvanillin and Benzimidazole Structure Improves DNA Binding with Enhanced Antileukemic Properties

PubMed Central

Al-Mudarris, Ban A.; Chen, Shih-Hsun; Liang, Po-Huang; Osman, Hasnah; Jamal Din, Shah Kamal Khan; Abdul Majid, Amin M. S.

2013-01-01

Benzyl-o-vanillin and benzimidazole nucleus serve as important pharmacophore in drug discovery. The benzyl vanillin (2-(benzyloxy)-3-methoxybenzaldehyde) compound shows anti-proliferative activity in HL60 leukemia cancer cells and can effect cell cycle progression at G2/M phase. Its apoptosis activity was due to disruption of mitochondrial functioning. In this study, we have studied a series of compounds consisting of benzyl vanillin and benzimidazole structures. We hypothesize that by fusing these two structures we can produce compounds that have better anticancer activity with improved specificity particularly towards the leukemia cell line. Here we explored the anticancer activity of three compounds namely 2-(2-benzyloxy-3-methoxyphenyl)-1H-benzimidazole, 2MP, N-1-(2-benzyloxy-3-methoxybenzyl)-2-(2-benzyloxy-3-methoxyphenyl)-1H-benzimidazole, 2XP, and (R) and (S)-1-(2-benzyloxy-3-methoxyphenyl)-2, 2, 2-trichloroethyl benzenesulfonate, 3BS and compared their activity to 2-benzyloxy-3-methoxybenzaldehyde, (Bn1), the parent compound. 2XP and 3BS induces cell death of U937 leukemic cell line through DNA fragmentation that lead to the intrinsic caspase 9 activation. DNA binding study primarily by the equilibrium binding titration assay followed by the Viscosity study reveal the DNA binding through groove region with intrinsic binding constant 7.39 µM/bp and 6.86 µM/bp for 3BS and 2XP respectively. 2XP and 3BS showed strong DNA binding activity by the UV titration method with the computational drug modeling showed that both 2XP and 3BS failed to form any electrostatic linkages except via hydrophobic interaction through the minor groove region of the nucleic acid. The benzylvanillin alone (Bn1) has weak anticancer activity even after it was combined with the benzimidazole (2MP), but after addition of another benzylvanillin structure (2XP), stronger activity was observed. Also, the combination of benzylvanillin with benzenesulfonate (3BS) significantly improved the anticancer activity of Bn1. The present study provides a new insight of benzyl vanillin derivatives as potential anti-leukemic agent. PMID:24260527

Synthesis, enantiomeric resolution, F-18 labeling and biodistribution of reboxetine analogs: promising radioligands for imaging the norepinephrine transporter with positron emission tomography.

PubMed

Lin, Kuo-Shyan; Ding, Yu-Shin; Kim, Sung-Won; Kil, Kun-Eek

2005-05-01

Racemic and enantiomerically pure ((S,S) and (R,R)) 2-[alpha-(2-(2-[(18)F]fluoroethoxy)phenoxy)benzyl]morpholine ([(18)F]FRB) and its tetradeuterated form [(18)F]FRB-D(4), analogs of the highly selective norepinephrine reuptake inhibitor reboxetine (2-[alpha-(2-ethoxyphenoxy)benzyl]morpholine, RB), have been synthesized for studies of norepinephrine transporter (NET) system with positron emission tomography (PET). The [(18)F]fluorinated precursor, (S,S)/(R,R)-N-tert-butyloxycarbonyl-2-[alpha-(2-hydroxyphenoxy)benzyl]morpholine ((S,S)/(R,R)-N-Boc-desethylRB), was prepared by the N-protection of (S,S)/(R,R)-2-[alpha-(2-hydroxyphenoxy)benzyl]morpholine ((S,S)/(R,R)-desethylRB) with a tert-butyloxycarbonyl (Boc) group followed by enantiomeric resolution with chiral HPLC to provide both (S,S) and (R,R) enantiomers with >99% enantiomeric purity. These compounds were then used for radiosynthesis to prepare enantiomerically pure [(18)F]FRB and [(18)F]FRB-D(4) via the following three-step procedure: (1) formation of 1-bromo-2-[(18)F]fluoroethane ([(18)F]BFE or [(18)F]BFE-D(4)) by nucleophilic displacement of 2-bromoethyl triflate (or D(4) analog) with no-carrier added [(18)F]F(-) in THF; (2) reaction of [(18)F]BFE (or [(18)F]BFE-D(4)) with N-Boc-desethylRB in DMF in the presence of excess base; and (3) deprotection with trifluoroacetic acid. The racemates, (S,S) and (R,R) enantiomers of [(18)F]FRB and [(18)F]FRB-D(4) were obtained in 11-27% (decay corrected to the end of bombardment, EOB) in 120-min synthesis time with a radiochemical purity of >98% and specific activities of 21-48 GBq/micromol (EOB). The results of the whole-body biodistribution studies with (S,S)-[(18)F]FRB-D(4) were similar to those with (S,S)-[(18)F]FRB but showed relatively faster blood clearance and no significant in vivo defluorination. Positron emission tomography studies in baboon brain also showed that (S,S)-[(18)F]FRB-D(4) may be a potentially useful ligand for imaging NET with PET.

Recognition of O6-benzyl-2′-deoxyguanosine by a perimidinone-derived synthetic nucleoside: a DNA interstrand stacking interaction

PubMed Central

Kowal, Ewa A.; Lad, Rahul R.; Pallan, Pradeep S.; Dhummakupt, Elizabeth; Wawrzak, Zdzislaw; Egli, Martin; Sturla, Shana J.; Stone, Michael P.

2013-01-01

The 2′-deoxynucleoside containing the synthetic base 1-[(2R,4S,5R)-4-hydroxy-5-(hydroxymethyl)-tetrahydrofuran-2-yl)-1H-perimidin-2(3H)-one] (dPer) recognizes in DNA the O6-benzyl-2′-deoxyguanosine nucleoside (O6-Bn-dG), formed by exposure to N-benzylmethylnitrosamine. Herein, we show how dPer distinguishes between O6-Bn-dG and dG in DNA. The structure of the modified Dickerson–Drew dodecamer (DDD) in which guanine at position G4 has been replaced by O6-Bn-dG and cytosine C9 has been replaced with dPer to form the modified O6-Bn-dG:dPer (DDD-XY) duplex [5′-d(C1G2C3X4A5A6T7T8Y9G10C11G12)-3′]2 (X = O6-Bn-dG, Y = dPer) reveals that dPer intercalates into the duplex and adopts the syn conformation about the glycosyl bond. This provides a binding pocket that allows the benzyl group of O6-Bn-dG to intercalate between Per and thymine of the 3′-neighbor A:T base pair. Nuclear magnetic resonance data suggest that a similar intercalative recognition mechanism applies in this sequence in solution. However, in solution, the benzyl ring of O6-Bn-dG undergoes rotation on the nuclear magnetic resonance time scale. In contrast, the structure of the modified DDD in which cytosine at position C9 is replaced with dPer to form the dG:dPer (DDD-GY) [5′-d(C1G2C3G4A5A6T7T8Y9G10C11G12)-3′]2 duplex (Y = dPer) reveals that dPer adopts the anti conformation about the glycosyl bond and forms a less stable wobble pairing interaction with guanine. PMID:23748954

Simultaneous determination of the UV-filters benzyl salicylate, phenyl salicylate, octyl salicylate, homosalate, 3-(4-methylbenzylidene) camphor and 3-benzylidene camphor in human placental tissue by LC-MS/MS. Assessment of their in vitro endocrine activity.

PubMed

Jiménez-Díaz, I; Molina-Molina, J M; Zafra-Gómez, A; Ballesteros, O; Navalón, A; Real, M; Sáenz, J M; Fernández, M F; Olea, N

2013-10-01

UV-filters are widely used in many personal care products and cosmetics. Recent studies indicate that some organic UV-filters can accumulate in biota and act as endocrine disruptors, but there are few studies on the occurrence and fate of these compounds in humans. In the present work, a new liquid chromatography-tandem mass spectrometry (LC-MS/MS) method to assess the presence of six UV-filters in current use (benzyl salicylate, phenyl salicylate, octyl salicylate, homosalate, 3-(4-methylbenzylidene) camphor, and 3-benzylidene camphor) in human placental tissue is proposed. The method involves the extraction of the analytes from the samples using ethyl acetate, followed by a clean-up step using centrifugation prior to their quantification by LC-MS/MS using an atmospheric pressure chemical ionization (APCI) interface. Bisphenol A-d16 was used as surrogate for the determination of benzyl salicylate, phenyl salicylate, octyl salicylate and homosalate in negative mode and benzophenone-d10, was used as surrogate for the determination of 3-(4-methylbenzylidene) camphor and 3-benzylidene camphor in positive mode. The found limits of detection ranged from 0.4 to 0.6ngg(-1) and the limits of quantification ranged from 1.3 to 2.0ngg(-1), while variability was under 13.7%. Recovery rates for spiked samples ranged from 97% to 104%. Moreover, the interactions of these compounds with the human estrogen receptor alpha (hERα) and androgen receptor (hAR), using two in vitro bioassays based on reporter gene expression and cell proliferation assessment, were also investigated. All tested compounds, except benzyl salicylate and octyl salicylate, showed estrogenic activity in the E-Screen bioassay whereas only homosalate and 3-(4-methylbenzylidene) camphor were potent hAR antagonists. Although free salicylate derivatives and free camphor derivatives were not detected in the human placenta samples analyzed, the observed estrogenic and anti-androgenic activities of some of these compounds support the analysis of their occurrence and their role as endocrine disrupters in humans. Copyright © 2013 Elsevier B.V. All rights reserved.

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

Absolute rate expressions for hydrogen atom abstraction from molybdenum hydrides by carbon-centered radicals

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

Franz, J.A.; Linehan, J.C.; Birnbaum, J.C.

1999-10-27

A new family of basis rate expressions for hydrogen atom abstraction by primary, secondary, and tertiary alkyl radicals in dodecane and benzyl radical in benzene from the molybdenum hydride Cp*Mo-(CO){sub 3}H and for reactions of a primary alkyl radical with CpMo(CO){sub 3}H in dodecane are reported (Cp* = {eta}{sup 5}-pentamethylcyclopentadienyl, Cp = {eta}{sup 5}-cyclopentadienyl). Rate expressions for reaction of primary, secondary, and tertiary radical clocks with Cp*Mo(CO){sub 3}H were as follows: for hex-5-enyl, log(k/M{sup {minus}1} s{sup {minus}1}) = (9.27 {+-} 0.13) {minus} (1.36 {+-} 0.22)/{theta}, {theta} = 2.303RT kcal/mol; for hept-6-en-2-yl, log(k/M{sup {minus}1} s{sup {minus}1}) = (9.12 {+-} 0.42) {minus}more » (1.91 {+-} 0.74)/{theta}; and for 2-methylhept-6-en-2-yl, log(k/M{sup {minus}1} s{sup {minus}1}) = (9.36 {+-} 0.18) {minus} (3.19 {+-} 0.30)/{theta} (errors are 2{sigma}). Hydrogen atom abstraction from CpMo(CO){sub 3}H by hex-5-enyl is described by log(k/M{sup {minus}1} s{sup {minus}1}) = (9.53 {+-} 0.34) {minus} (1.24 {+-} 0.62)/{theta}. Relative rate constants for 1{degree}:2{degree}:3{degree} alkyl radicals were found to be 26:7:1 at 298 K. Benzyl radical was found to react 1.4 times faster than tertiary alkyl radical. The much higher selectivities for CP*Mo(CO){sub 3}H than those observed for main group hydrides (Bu{sub 3}SnH, PhSeH, PhSH) with alkyl radicals, together with the very fast benzyl hydrogen-transfer rate, suggest the relative unimportance of simple enthalpic effects and the dominance of steric effects for the early transition-state hydrogen transfers. Hydrogen abstraction from Cp*Mo(CO){sub 3}H by benzyl radicals is described by log(k/M{sup {minus}1} s{sup {minus}1}) = (8.89 {+-} 0.22) {minus} (2.31 {+-} 0.33)/{theta}.« less

40 CFR Table 2 to Subpart Ggg of... - Partially Soluble HAP

Code of Federal Regulations, 2014 CFR

2014-07-01

... Xylene (p) Vinyl chloride N-hexane Xylene (m) Xylene (o) [66 FR 40136, Aug. 2, 2001] ... Acrylonitrile Methylene chloride Allyl chloride N,N-dimethylaniline Benzene Propionaldehyde Benzyl chloride...

40 CFR Table 2 to Subpart Ggg of... - Partially Soluble HAP

Code of Federal Regulations, 2013 CFR

2013-07-01

... Xylene (p) Vinyl chloride N-hexane Xylene (m) Xylene (o) [66 FR 40136, Aug. 2, 2001] ... Acrylonitrile Methylene chloride Allyl chloride N,N-dimethylaniline Benzene Propionaldehyde Benzyl chloride...

21 CFR 1310.02 - Substances covered.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 8519 (2) Acetone 6532 (3) Benzyl chloride 8570 (4) Ethyl ether 6584 (5) Potassium permanganate 6579 (6... Permanganate 6588 (c) The Administrator may add or delete a substance as a listed chemical by publishing a...

40 CFR 721.329 - Halogenated benzyl ester acrylate (generic).

Code of Federal Regulations, 2011 CFR

2011-07-01

...) TOXIC SUBSTANCES CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for... when the PMN substance is bound or embedded into a plastic, resin matrix, or pellet. (iii) Industrial...

40 CFR 721.329 - Halogenated benzyl ester acrylate (generic).

Code of Federal Regulations, 2010 CFR

2010-07-01

...) TOXIC SUBSTANCES CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for... when the PMN substance is bound or embedded into a plastic, resin matrix, or pellet. (iii) Industrial...

Tsuji-Trost N-allylation with allylic acetates using cellulose-Pd catalyst

EPA Science Inventory

Allylic amines are synthesized using heterogeneous cellulose-Pd catalyst via N-allylation of amines; aliphatic and benzyl amines undergo facile reaction with substituted and unsubstituted allyl acetates in high yields.

21 CFR 1310.02 - Substances covered.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 8519 (2) Acetone 6532 (3) Benzyl chloride 8570 (4) Ethyl ether 6584 (5) Potassium permanganate 6579 (6... Permanganate 6588 (c) The Administrator may add or delete a substance as a listed chemical by publishing a...

Extraction and Chromatographic Determination of Shikimic Acid in Chinese Conifer Needles with 1-Benzyl-3-methylimidazolium Bromide Ionic Liquid Aqueous Solutions

PubMed Central

Chen, Fengli; Hou, Kexin; Li, Shuangyang; Zu, Yuangang; Yang, Lei

2014-01-01

An ionic liquids-based ultrasound-assisted extraction (ILUAE) method was successfully developed for extracting shikimic acid from conifer needles. Eleven 1-alkyl-3-methylimidazolium ionic liquids with different cations and anions were investigated and 1-benzyl-3-methylimidazolium bromide solution was selected as the solvent. The conditions for ILUAE, including the ionic liquid concentration, ultrasound power, ultrasound time, and liquid-solid ratio, were optimized. The proposed method had good recovery (99.37%–100.11%) and reproducibility (RSD, n = 6; 3.6%). ILUAE was an efficient, rapid, and simple sample preparation technique that showed high reproducibility. Based on the results, a number of plant species, namely, Picea koraiensis, Picea meyeri, Pinus elliottii, and Pinus banksiana, were identified as among the best resources of shikimic acid. PMID:24782942

(2E,5E)-2,5-Bis(4-hy-droxy-3-meth-oxy-benzyl-idene)cyclo-penta-none ethanol monosolvate.

PubMed

Da'i, Muhammad; Yanuar, Arry; Meiyanto, Edy; Jenie, Umar Anggara; Supardjan, Amir Margono

2013-04-01

In the title structure, C21H20O5·C2H5OH, the curcumine-type mol-ecule has a double E conformation for the two benzyl-idene double bonds [C=C = 1.342 (4) and 1.349 (4) Å] and is nearly planar with respect to the non-H atoms (r.m.s. deviation from planarity = 0.069 Å). The two phenolic OH groups form bifurcated hydrogen bonds with intra-molecular branches to adjacent meth-oxy O atoms and inter-molecular branches to either a neighbouring mol-ecule or an ethanol solvent mol-ecule. The ethanol O atom donates a hydrogen bond to the keto O atom. These hydrogen bonds link the constituents into layers parallel to (101) in the crystal structure.

Benzyl Alcohol-Mediated Versatile Method to Fabricate Nonstoichiometric Metal Oxide Nanostructures.

PubMed

Qamar, Mohammad; Adam, Alaaldin; Azad, Abdul-Majeed; Kim, Yong-Wah

2017-11-22

Nanostructured metal oxides with cationic or anionic deficiency find applications in a wide range of technological areas including the energy sector and environment. However, a facile route to prepare such materials in bulk with acceptable reproducibility is still lacking; many synthesis techniques are still only bench-top and cannot be easily scaled-up. Here, we report that the benzyl alcohol (BA)-mediated method is capable of producing a host of nanostructured metal oxides (MO x , where M = Ti, Zn, Ce, Sn, In, Ga, or Fe) with inherent nonstoichiometry. It employs multifunctional BA as a solvent, a reducing agent, and a structure-directing agent. Depending on the oxidation states of metal, elemental or nonstoichiometric oxide forms are obtained. Augmented photoelectrochemical oxidation of water under visible light by some of these nonstoichiometric oxides highlights the versatility of the BA-mediated synthesis protocol.

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

Dichlorido[N′-(3,5-dichloro-2-hydroxy­benzyl­idene)pyridine-4-carbohydrazide-κN](1,10-phenanthroline-κ2 N,N′)cobalt(II) methanol monosolvate

PubMed Central

Wang, Yuan; Liu, Zheng; Liu, Baoyu

2009-01-01

In the title compound, [CoCl2(C13H9Cl2N3O2)2(C12H8N2)]·CH3OH, the CoII atom is octahedrally coordinated by two N atoms from the pyridyl rings of the tridentate N′-(3,5-dichloro-2-hydroxy­benzyl­idene)pyridine-4-carbohydrazide (H2 L) ligand, two N atoms from the 1,10-phenanthroline ligand and two chloride ions. The acyl­hydrazone groups are not involved into the coordination of the metal ion. In the crystal packing an extended three-dimensional network formed by N—H⋯Cl, N—H⋯O, O—H⋯N, O—H⋯N and O—H⋯Cl hydrogen bonds is observed. PMID:21578623

Synthesis and biological screening of 2'-aryl/benzyl-2-aryl-4-methyl-4',5-bithiazolyls as possible anti-tubercular and antimicrobial agents.

PubMed

Abhale, Yogita K; Sasane, Amit V; Chavan, Abhijit P; Deshmukh, Keshav K; Kotapalli, Sudha Sravanti; Ummanni, Ramesh; Sayyad, Sadikali F; Mhaske, Pravin C

2015-04-13

A series of 2'-aryl/benzyl-2-aryl-4-methyl-4',5-bithiazolyl derivatives, 25-64 were synthesized and evaluated for inhibitory activity against Mycobacterium smegmatis MC(2) 155 strain and antimicrobial activities against four pathogenic bacteria Bacillus subtilis, Staphylococcus aureus, Escherichia coli and Proteus vulgaris. Among them, compounds 40, 49, 50, and 54 exhibited moderate to good inhibition on the growth of the bacteria Mycobacterium smegmatis at the concentration of 30 μM. Compounds 26, 40, 44, 54 and 56 exhibited moderate to good antibacterial activity. Compound 5-(2'-(4-fluorobenzyl)thiazol-4'-yl)-2-(4-fluorophenyl)-4-methyl-thiazole (54) exhibited both antitubercular as well as antimicrobial activity against all tested strains. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

Identification and characterization of potential impurities of donepezil.

PubMed

Krishna Reddy, K V S R; Moses Babu, J; Kumar, P Anil; Chandrashekar, E R R; Mathad, Vijayavitthal T; Eswaraiah, S; Reddy, M Satyanarayana; Vyas, K

2004-09-03

Five unknown impurities ranging from 0.05 to 0.2% in donepezil were detected by a simple isocratic reversed-phase high performance liquid chromatography (HPLC). These impurities were isolated from crude sample of donepezil using isocratic reversed-phase preparative high performance liquid chromatography. Based on the spectral data (IR, NMR and MS), the structures of these impurities were characterised as 5,6-dimethoxy-2-(4-pyridylmethyl)-1-indanone (impurity I), 4-(5,6-dimethoxy-2,3-dihydro-1H-2-indenylmethyl) piperidine (impurity II), 2-(1-benzyl-4-piperdylmethyl)-5,6-dimethoxy-1-indanol (impurity III) 1-benzyl-4(5,6-dimethoxy-2,3-dihydro-1H-2-indenylmethyl) piperidine (impurity IV) and 1,1-dibenzyl-4(5,6-dimethoxy-1-oxo-2,3-dihydro-2H-2-indenylmethyl)hexahydropyridinium bromide (impurity V). The synthesis of these impurities and their formation was discussed.

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.

Structure-based design of benzimidazole sugar conjugates: synthesis, SAR and in vivo anti-inflammatory and analgesic activities.

PubMed

El-Nezhawy, Ahmed O H; Gaballah, Samir T; Radwan, Mohamed A A; Baiuomy, Ayman R; Abdel-Salam, Omar M E

2009-11-01

A series of 2-methyl-N-substituted-benzimidazoles, bearing hydroxypyrrolidinon-5-yl or hydroxypyrrolidin-2-yl, 2,3:5,6-di-O-isopropylidene-alpha-D-mannofuranoside, 2,3,5,6-tetrahydroxy-alpha-D-mannofuranoside, 1:2,5:6-di-O-isopropylidene-alpha-D-gluco-furanose,3-O-benzyl-6,7-dideoxy-1:2-O-isopropylidene-alpha-D-xylo-heptofuranos-5-ulose, 3-O-benzyl-6,7-dideoxy-1,2-dihydroxy-alpha-D-xylo-heptofuranos-5-ulose, 1,2,5,6-tetrahydroxy-alpha-D-glucofuranose sugar moieties, were obtained in good yields from 2-methyl N-(trichloroacetamidomethyl)benzimidazole as a donor and carbohydrate residues as acceptor precursors in the presence of catalytic amount of trimethylsilyl trifluoromethanesulfonate (TMSOTf) as Lewis acid. Compounds 6, 7, 10, 13, 15, and 16 showed significant anti-inflammatory and analgesic activities.

Spectral and catalytic properties of aryl-alcohol oxidase, a fungal flavoenzyme acting on polyunsaturated alcohols

PubMed Central

2005-01-01

Spectral and catalytic properties of the flavoenzyme AAO (aryl-alcohol oxidase) from Pleurotus eryngii were investigated using recombinant enzyme. Unlike most flavoprotein oxidases, AAO does not thermodynamically stabilize a flavin semiquinone radical and forms no sulphite adduct. AAO catalyses the oxidative dehydrogenation of a wide range of unsaturated primary alcohols with hydrogen peroxide production. This differentiates the enzyme from VAO (vanillyl-alcohol oxidase), which is specific for phenolic compounds. Moreover, AAO is optimally active in the pH range of 5–6, whereas VAO has an optimum at pH 10. Kinetic studies showed that AAO is most active with p-anisyl alcohol and 2,4-hexadien-1-ol. AAO converts m- and p-chlorinated benzyl alcohols at a similar rate as it does benzyl alcohol, but introduction of a p-methoxy substituent in benzyl alcohol increases the reaction rate approx. 5-fold. AAO also exhibits low activity on aromatic aldehydes. 19F NMR analysis showed that fluorinated benzaldehydes are converted into the corresponding benzoic acids. Inhibition studies revealed that the AAO active site can bind a wide range of aromatic ligands, chavicol (4-allylphenol) and p-anisic (4-methoxybenzoic) acid being the best competitive inhibitors. Uncompetitive inhibition was observed with 4-methoxybenzylamine. The properties described above render AAO a unique oxidase. The possible mechanism of AAO binding and oxidation of substrates is discussed in the light of the results of the inhibition and kinetic studies. PMID:15813702

Contact and fumigant toxicity of Armoracia rusticana essential oil, allyl isothiocyanate and related compounds to Dermatophagoides farinae.

PubMed

Yun, Yeon-Kyeong; Kim, Hyun-Kyung; Kim, Jun-Ran; Hwang, Kumnara; Ahn, Young-Joon

2012-05-01

The toxicity to adult Dermatophagoides farinae of allyl isothiocyanate identified in horseradish, Armoracia rusticana, oil and another 27 organic isothiocyanates was evaluated using contact + fumigant and vapour-phase mortality bioassays. Results were compared with those of two conventional acaricides, benzyl benzoate and dibutyl phthalate. Horseradish oil (24 h LC(50), 1.54 µg cm(-2)) and allyl isothiocyanate (2.52 µg cm(-2)) were highly toxic. Benzyl isothiocyanate (LC(50) , 0.62 µg cm(-2)) was the most toxic compound, followed by 4-chlorophenyl, 3-bromophenyl, 3,5-bis(trifluoromethyl)phenyl, cyclohexyl, 2-chlorophenyl, 4-bromophenyl and 2-bromophenyl isothiocyanates (0.93-1.41 µg cm(-2)). All were more effective than either benzyl benzoate (LC(50) , 4.58 µg cm(-2)) or dibutyl phthalate (24.49 µg cm(-2)). The structure-activity relationship indicates that types of functional group and chemical structure appear to play a role in determining the isothiocyanate toxicities to adult D. farinae. In the vapour-phase mortality bioassay, these isothiocyanates were consistently more toxic in closed versus open containers, indicating that their mode of delivery was, in part, a result of vapour action. In the light of global efforts to reduce the level of highly toxic synthetic acaricides in indoor environments, the horseradish oil-derived compounds and the isothiocyanates described herein merit further study as potential acaricides for the control of house dust mite populations as fumigants with contact action. Copyright © 2011 Society of Chemical Industry.

First derivative spectrophotometric determination of granisetron hydrochloride in presence of its hydrolytic products and preservative and application to pharmaceutical preparations.

PubMed

Hewala, Ismail I; Bedair, Mona M; Shousha, Sherif M

2013-04-01

Granisetron is a selective 5-HT3 receptor antagonist used in prevention and treatment of chemotherapy-induced nausea and vomiting. The drug is available in tablet dosage form and parenteral dosage form containing benzyl alcohol as a preservative. The main route of degradation of granisetron is through hydrolysis. The present work describes the development of a simple, rapid, and reliable first derivative spectrophotometric method for the determination of granisetron in presence of its hydrolytic products as well as the formulations adjuvant and benzyl alcohol. The method is based on the measurement of the first derivative response of granisetron at 290 nm where the interference of the hydrolytic products, the co-formulated adjuvant and benzyl alcohol is completely eliminated. The proposed method was validated with respect to specificity, linearity, selectivity, accuracy, precision, robustness, detection, and quantification limits. Regression analysis showed good correlation between the first derivative response and the concentration of granisetron over a range of 8-16 μg ml(-1) . Statistical analysis proved the accuracy of the proposed method compared with a reference stability indicating high performance liquid chromatography method. The described method was successfully applied to the determination of granisetron in different batches of tablets and ampoules. The assay results obtained in this study strongly encourage us to apply the validated method for the quality control and routine analysis of tablets and parenteral preparations containing granisetron. Copyright © 2012 John Wiley & Sons, Ltd.

Aromatic organosulfates in atmospheric aerosols: synthesis, characterization, and abundance.

PubMed

Staudt, Sean; Kundu, Shuvashish; Lehmler, Hans-Joachim; He, Xianran; Cui, Tianqu; Lin, Ying-Hsuan; Kristensen, Kasper; Glasius, Marianne; Zhang, Xiaolu; Weber, Rodney J; Surratt, Jason D; Stone1, Elizabeth A

2014-09-01

Aromatic organosulfates are identified and quantified in fine particulate matter (PM 2.5 ) from Lahore, Pakistan, Godavari, Nepal, and Pasadena, California. To support detection and quantification, authentic standards of phenyl sulfate, benzyl sulfate, 3-and 4-methylphenyl sulfate and 2-, 3-, and 4-methylbenzyl sulfate were synthesized. Authentic standards and aerosol samples were analyzed by ultra-performance liquid chromatography (UPLC) coupled to negative electrospray ionization (ESI) quadrupole time-of-flight (ToF) mass spectrometry. Benzyl sulfate was present in all three locations at concentrations ranging from 4 - 90 pg m -3 . Phenyl sulfate, methylphenyl sulfates and methylbenzyl sulfates were observed intermittently with abundances of 4 pg m -3 , 2-31 pg m -3 , 109 pg m -3 , respectively. Characteristic fragment ions of aromatic organosulfates include the sulfite radical ( • SO 3 - , m/z 80) and the sulfate radical ( • SO 4 - , m/z 96). Instrumental response factors of phenyl and benzyl sulfates varied by a factor of 4.3, indicating that structurally-similar organosulfates may have significantly different instrumental responses and highlighting the need to develop authentic standards for absolute quantitation organosulfates. In an effort to better understand the sources of aromatic organosulfates to the atmosphere, chamber experiments with the precursor toluene were conducted under conditions that form biogenic organosulfates. Aromatic organosulfates were not detected in the chamber samples, suggesting that they form through different pathways, have different precursors (e.g. naphthalene or methylnaphthalene), or are emitted from primary sources.

Crystal structure and electrochemical properties of [Ni(bztmpen)(CH3CN)](BF4)2 {bztmpen is N-benzyl-N,N',N'-tris-[(6-methyl-pyridin-2-yl)meth-yl]ethane-1,2-di-amine}.

PubMed

Chen, Lin; Ren, Gan; Guo, Yakun; Sang, Ge

2017-06-01

The mononuclear nickel title complex (acetonitrile-κ N ){ N -benzyl- N , N ', N '-tris-[(6-methyl-pyridin-2-yl)meth-yl]ethane-1,2-di-amine}-nickel(II) bis-(tetra-fluor-ido-borate), [Ni(C 30 H 35 N 5 )(CH 3 CN)](BF 4 ) 2 , was prepared from the reaction of Ni(BF 4 ) 2 ·6H 2 O with N -benzyl- N , N ', N '-tris-[(6-methyl-pyridin-2-yl)meth-yl]ethane-1,2-di-amine ( bztmpen ) in aceto-nitrile at room temperature. With an open site occupied by the aceto-nitrile mol-ecule, the nickel(II) atom is chelated by five N-atom sites from the ligand and one N atom from the ligand, showing an overall octa-hedral coordination environment. Compared with analogues where the 6-methyl substituent is absent, the bond length around the Ni 2+ cation are evidently longer. Upon reductive dissociation of the acetro-nitrile mol-ecule, the title complex has an open site for a catalytic reaction. The title complex has two redox couples at -1.50 and -1.80 V ( versus F c +/0 ) based on nickel. The F atoms of the two BF 4 - counter-anions are split into two groups and the occupancy ratios refined to 0.611 (18):0.389 (18) and 0.71 (2):0.29 (2).

Strong induction of iodothyronine deiodinases by chemotherapeutic selenocompounds.

PubMed

Stoedter, M; Renko, K; Ibáñez, E; Plano, D; Becker, N-P; Martitz, J; Palop, J A; Calvo, A; Sanmartín, C; Schomburg, L

2015-02-01

The biological activity of thyroid hormones (TH) is regulated by selenoenzymes of the iodothyronine deiodinase (DIO) family catalysing TH activating and inactivating reactions. Besides TH metabolism, several studies indicate an important role of DIO isoenzymes in tumorigenesis and cancer growth. It is therefore of therapeutic importance to identify modulators of DIO expression. We have synthesized and studied a series of selenocompounds containing a methyl- or benzyl-imidoselenocarbamate backbone. One of these novel compounds had chemotherapeutic activities in a murine xenograft tumour model by an unknown mechanism. Therefore, we tested their effects on DIO expression in vitro. In HepG2 hepatocarcinoma cells, DIO1 activity was strongly (up to 10-fold) increased by the methyl- but not by the corresponding benzyl-imidoselenocarbamates. Steady-state mRNA levels remained unaltered under these conditions indicating a post-transcriptional mode of action. The effects were further characterized in HEK293 cells stably expressing DIO1, DIO2 or DIO3. Even within the artificial genetic context of the expression vectors, all three DIO isoenzymes were up-regulated by the methyl- and to a lesser extent by the benzyl-imidoselenocarbamates. Consistent stimulating effects were observed with methyl-N,N'-di(quinolin-3-ylcarbonyl)-imidoselenocarbamate (EI201), a selenocompound known for its anti-tumour activity. DIO inducing effects were unrelated to the intracellular accumulation of selenium, yet the precise mode of action remains elusive. Collectively, our data highlight that these selenocompounds may constitute interesting pharmacological compounds for modifying DIO expression potentially affecting the balance between cell differentiation and proliferation.

Environmentally friendly synthesis of CeO2 nanoparticles for the catalytic oxidation of benzyl alcohol to benzaldehyde and selective detection of nitrite

NASA Astrophysics Data System (ADS)

Tamizhdurai, P.; Sakthinathan, Subramanian; Chen, Shen-Ming; Shanthi, K.; Sivasanker, S.; Sangeetha, P.

2017-04-01

Cerium oxide nanoparticles (CeO2 NPs) are favorable in nanotechnology based on some remarkable properties. In this study, the crystalline CeO2 NPs are successfully prepared by an efficient microwave combustion (MCM) and conventional route sol-gel (CRSGM) methods. The structural morphology of the as-prepared CeO2 NPs was investigated by various spectroscopic and analytical techniques. Moreover, the XRD pattern confirmed the formation of CeO2 NPs as a face centered cubic structure. The magnetometer studies indicated the low saturation magnetization (23.96 emu/g) of CeO2 NPs for weak paramagnetic and high saturation magnetization (32.13 emu/g) of CeO2 NPs for super paramagnetic. After that, the oxidation effect of benzyl alcohol was investigated which reveals good conversion and selectivity. Besides, the CeO2 NPs modified glassy carbon electrode (GCE) used for the detection of nitrite with linear concentration range (0.02-1200 μM), low limit of detection (0.21 μM) and higher sensitivity (1.7238 μAμM-1 cm-2). However, the CeO2 NPs modified electrode has the fast response, high sensitivity and good selectivity. In addition, the fabricated electrode is applied for the determination of nitrite in various water samples. Eventually, the CeO2 NPs can be regarded as an effective way to enhance the catalytic activity towards the benzyl alcohol and nitrite.

Aromatic organosulfates in atmospheric aerosols: Synthesis, characterization, and abundance

NASA Astrophysics Data System (ADS)

Staudt, Sean; Kundu, Shuvashish; Lehmler, Hans-Joachim; He, Xianran; Cui, Tianqu; Lin, Ying-Hsuan; Kristensen, Kasper; Glasius, Marianne; Zhang, Xiaolu; Weber, Rodney J.; Surratt, Jason D.; Stone, Elizabeth A.

2014-09-01

Aromatic organosulfates are identified and quantified in fine particulate matter (PM2.5) from Lahore, Pakistan, Godavari, Nepal, and Pasadena, California. To support detection and quantification, authentic standards of phenyl sulfate, benzyl sulfate, 3- and 4-methylphenyl sulfate and 2-, 3-, and 4-methylbenzyl sulfate were synthesized. Authentic standards and aerosol samples were analyzed by ultra-performance liquid chromatography (UPLC) coupled to negative electrospray ionization (ESI) quadrupole time-of-flight (ToF) mass spectrometry. Benzyl sulfate was present in all three locations at concentrations ranging from 4 to 90 pg m-3. Phenyl sulfate, methylphenyl sulfates and methylbenzyl sulfates were observed intermittently with abundances of 4 pg m-3, 2-31 pg m-3, 109 pg m-3, respectively. Characteristic fragment ions of aromatic organosulfates include the sulfite radical (rad SO3-, m/z 80) and the sulfate radical (rad SO4-, m/z 96). Instrumental response factors of phenyl and benzyl sulfates varied by a factor of 4.3, indicating that structurally-similar organosulfates have significantly different instrumental responses and highlighting the need to develop authentic standards for absolute quantitation organosulfates. In an effort to better understand the sources of aromatic organosulfates to the atmosphere, chamber experiments with the precursor toluene were conducted under conditions that form biogenic organosulfates. Aromatic organosulfates were not detected in the chamber samples, suggesting that they form through different pathways, have different precursors (e.g. naphthalene or methylnaphthalene), or are emitted from primary sources.

The molecular mechanism studies of chirality effect of PHA-739358 on Aurora kinase A by molecular dynamics simulation and free energy calculations

NASA Astrophysics Data System (ADS)

Cheng, Yuanhua; Cui, Wei; Chen, Quan; Tung, Chen-Ho; Ji, Mingjuan; Zhang, Fushi

2011-02-01

Aurora kinase family is one of the emerging targets in oncology drug discovery and several small molecules targeting aurora kinases have been discovered and evaluated under early phase I/II trials. Among them, PHA-739358 (compound 1r) is a 3-aminopyrazole derivative with strong activity against Aurora A under early phase II trial. Inhibitory potency of compound 1r (the benzylic substituent at the pro-R position) is 30 times over that of compound 1s (the benzylic substituent at the pro-S position). In present study, the mechanism of how different configurations influence the binding affinity was investigated using molecular dynamics (MD) simulations, free energy calculations and free energy decomposition analysis. The predicted binding free energies of these two complexes are consistent with the experimental data. The analysis of the individual energy terms indicates that although the van der Waals contribution is important for distinguishing the binding affinities of these two inhibitors, the electrostatic contribution plays a more crucial role in that. Moreover, it is observed that different configurations of the benzylic substituent could form different binding patterns with protein, thus leading to variant inhibitory potency of compounds 1r and 1s. The combination of different molecular modeling techniques is an efficient way to interpret the chirality effects of inhibitors and our work gives valuable information for the chiral drug design in the near future.

Environmentally friendly synthesis of CeO2 nanoparticles for the catalytic oxidation of benzyl alcohol to benzaldehyde and selective detection of nitrite

PubMed Central

Tamizhdurai, P.; Sakthinathan, Subramanian; Chen, Shen-Ming; Shanthi, K.; Sivasanker, S.; Sangeetha, P.

2017-01-01

Cerium oxide nanoparticles (CeO2 NPs) are favorable in nanotechnology based on some remarkable properties. In this study, the crystalline CeO2 NPs are successfully prepared by an efficient microwave combustion (MCM) and conventional route sol-gel (CRSGM) methods. The structural morphology of the as-prepared CeO2 NPs was investigated by various spectroscopic and analytical techniques. Moreover, the XRD pattern confirmed the formation of CeO2 NPs as a face centered cubic structure. The magnetometer studies indicated the low saturation magnetization (23.96 emu/g) of CeO2 NPs for weak paramagnetic and high saturation magnetization (32.13 emu/g) of CeO2 NPs for super paramagnetic. After that, the oxidation effect of benzyl alcohol was investigated which reveals good conversion and selectivity. Besides, the CeO2 NPs modified glassy carbon electrode (GCE) used for the detection of nitrite with linear concentration range (0.02–1200 μM), low limit of detection (0.21 μM) and higher sensitivity (1.7238 μAμM−1 cm−2). However, the CeO2 NPs modified electrode has the fast response, high sensitivity and good selectivity. In addition, the fabricated electrode is applied for the determination of nitrite in various water samples. Eventually, the CeO2 NPs can be regarded as an effective way to enhance the catalytic activity towards the benzyl alcohol and nitrite. PMID:28406231

The Redox Cycler Plasmodione Is a Fast-Acting Antimalarial Lead Compound with Pronounced Activity against Sexual and Early Asexual Blood-Stage Parasites.

PubMed

Ehrhardt, Katharina; Deregnaucourt, Christiane; Goetz, Alice-Anne; Tzanova, Tzvetomira; Gallo, Valentina; Arese, Paolo; Pradines, Bruno; Adjalley, Sophie H; Bagrel, Denyse; Blandin, Stephanie; Lanzer, Michael; Davioud-Charvet, Elisabeth

2016-09-01

Previously, we presented the chemical design of a promising series of antimalarial agents, 3-[substituted-benzyl]-menadiones, with potent in vitro and in vivo activities. Ongoing studies on the mode of action of antimalarial 3-[substituted-benzyl]-menadiones revealed that these agents disturb the redox balance of the parasitized erythrocyte by acting as redox cyclers-a strategy that is broadly recognized for the development of new antimalarial agents. Here we report a detailed parasitological characterization of the in vitro activity profile of the lead compound 3-[4-(trifluoromethyl)benzyl]-menadione 1c (henceforth called plasmodione) against intraerythrocytic stages of the human malaria parasite Plasmodium falciparum We show that plasmodione acts rapidly against asexual blood stages, thereby disrupting the clinically relevant intraerythrocytic life cycle of the parasite, and furthermore has potent activity against early gametocytes. The lead's antiplasmodial activity was unaffected by the most common mechanisms of resistance to clinically used antimalarials. Moreover, plasmodione has a low potential to induce drug resistance and a high killing speed, as observed by culturing parasites under continuous drug pressure. Drug interactions with licensed antimalarial drugs were also established using the fixed-ratio isobologram method. Initial toxicological profiling suggests that plasmodione is a safe agent for possible human use. Our studies identify plasmodione as a promising antimalarial lead compound and strongly support the future development of redox-active benzylmenadiones as antimalarial agents. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

The Redox Cycler Plasmodione Is a Fast-Acting Antimalarial Lead Compound with Pronounced Activity against Sexual and Early Asexual Blood-Stage Parasites

PubMed Central

Ehrhardt, Katharina; Deregnaucourt, Christiane; Goetz, Alice-Anne; Tzanova, Tzvetomira; Gallo, Valentina; Arese, Paolo; Pradines, Bruno; Adjalley, Sophie H.; Bagrel, Denyse; Blandin, Stephanie; Lanzer, Michael

2016-01-01

Previously, we presented the chemical design of a promising series of antimalarial agents, 3-[substituted-benzyl]-menadiones, with potent in vitro and in vivo activities. Ongoing studies on the mode of action of antimalarial 3-[substituted-benzyl]-menadiones revealed that these agents disturb the redox balance of the parasitized erythrocyte by acting as redox cyclers—a strategy that is broadly recognized for the development of new antimalarial agents. Here we report a detailed parasitological characterization of the in vitro activity profile of the lead compound 3-[4-(trifluoromethyl)benzyl]-menadione 1c (henceforth called plasmodione) against intraerythrocytic stages of the human malaria parasite Plasmodium falciparum. We show that plasmodione acts rapidly against asexual blood stages, thereby disrupting the clinically relevant intraerythrocytic life cycle of the parasite, and furthermore has potent activity against early gametocytes. The lead's antiplasmodial activity was unaffected by the most common mechanisms of resistance to clinically used antimalarials. Moreover, plasmodione has a low potential to induce drug resistance and a high killing speed, as observed by culturing parasites under continuous drug pressure. Drug interactions with licensed antimalarial drugs were also established using the fixed-ratio isobologram method. Initial toxicological profiling suggests that plasmodione is a safe agent for possible human use. Our studies identify plasmodione as a promising antimalarial lead compound and strongly support the future development of redox-active benzylmenadiones as antimalarial agents. PMID:27297478

Benzylic rearrangement stable isotope labeling for quantitation of guanidino and ureido compounds in thyroid tissues by liquid chromatography-electrospray ionization mass spectrometry.

PubMed

Fan, Ruo-Jing; Guan, Qing; Zhang, Fang; Leng, Jia-Peng; Sun, Tuan-Qi; Guo, Yin-Long

2016-02-18

Benzylic rearrangement stable isotope labeling (BRSIL) was explored to quantify the guanidino and ureido compounds (GCs and UCs). This method employed a common reagent, benzil, to label the guanidino and ureido groups through nucleophilic attacking then benzylic migrating. The use of BRSIL was investigated in the analysis of five GCs (creatine, l-arginine, homoarginine, 4-guanidinobutyric acid, and methylguanidine) and two UCs (urea and citrulline). The labeling was found simple and specific. The introduction of bi-phenyl group and the generation of nitrogen heterocyclic ring in the benzil-d0/d5 labeled GCs and UCs improved the retention behaviors in liquid chromatography (LC) and increased the sensitivity of electrospray ionization mass spectrometry (ESI MS) detection. The fragment ion pairs of m/z 182/187 and m/z 210/215 from the benzil-d0/d5 tags facilitated the discovery of potential GCs and UCs candidates residing in biological matrices. The use of BRSIL combined with LC-ESI MS was applied for simultaneously quantitation of GCs and UCs in thyroid tissues. It was demonstrated that nine GCs and UCs were detected, six of which were further quantified based on corresponding standards. It was concluded that five GCs and UCs (l-arginine, homoarginine, 4-guanidinobutyric acid, methylguanidine, and citrulline) were statistically significantly different (p < 0.05) between the para-carcinoma and carcinoma thyroid tissue samples. Copyright © 2016 Elsevier B.V. All rights reserved.

Copper-containing monooxygenases: enzymatic and biomimetic studies of the O-atom transfer catalysis.

PubMed

Blain, Ingrid; Slama, Patrick; Giorgi, Michel; Tron, Thierry; Réglier, Marius

2002-04-01

This review reports our recent studies or the mechanism of O-atom transfer to a benzylic C-H bond promoted by Dopamine beta-Hydroxylase (DBH) and its biomimetic models. We demonstrate that it is possible to carry out parallel and comparative studies on this enzyme (DBH) and its biomimetic models with the same substrate: 2-aminoindane (3). It was chosen because its two stereogenic centers, both in benzylic positions, make it very powerful for studying the stereochemistry of an O-atom transfer reaction. DBH-catalyzed hydroxylation of 3 produced exclusively 14% of trans-(1S,2S)-2-amino-1-indanol (4) (93% ee). Studies with stereospecifically deuterium-labeled 2-aminoindanes (1R,2S)-3b and (1S,2S)-3a showed that the formation of 4 was the rcsult of an overall process with retention of configuration where an O-atom is stereospecifically inserted in the trans pro-S position of the substrate. With copper(I) and (II) complexes of IndPY2 ligands we studied the reaction with dioxygen and observed an O-atom transfer to a benzylic C-H bond which was performed in the same manner as that of DBH. With the deuterium-labeled cis-2-d-IndPY2 ligand, we demonstrated that the reaction occurs by a stereospecific process with retention of configuration. In both cases (enzymatic vs. biomimetic) the O-atom transfers occur in a two-step process involving radical intermediates.

Ligand exchange and MIP-based paraoxon memories onto QCM sensor

NASA Astrophysics Data System (ADS)

Birlik Özkütük, Ebru; Emir Diltemiz, Sibel; Özalp, Elif; Uzun, Lokman; Ersöz, Arzu

2015-04-01

In this study, we have aimed to prepare quartz crystal microbalance (QCM) sensor using paraoxon-imprinted particles. Firstly, methacryloyl antipyrine (MAAP)-based metal-chelate-coordinated pre-complex has been prepared and used for paraoxon templation. Then, paraoxon-imprinted nanofilms were formed on QCM sensor after modification of the gold surfaces with allyl mercaptan. By this way, specific and selective memories, which depend on metal-chelate interactions between Eu(III) ions and template, for paraoxon molecules have been obtained on the electrode surface. QCM sensor has characterized using AFM and ellipsometer. The detection limit and the affinity constant have found to be 0.09 μM and 5.71 × 103 M-1 for MAAP-Eu paraoxon-based nanofilm, respectively. The specificity of the QCM sensor has shown using parathion as a competitor molecule.

Comparison of Two Spectrophotometric Techniques for Nutrients Analyses in Water Samples

NASA Astrophysics Data System (ADS)

Bartošová, Alica; Michalíková, Anna; Sirotiak, Maroš; Soldán, Maroš

2013-01-01

The aim of this contribution is to compare two common techniques for determining the concentrations of nitrate, nitrite, ammonium and phosphates in surface water and groundwater. Excess of these nutrients in water can directly affect human health (e.g. methemoglobinaemia) or indirectly through the products of secondary pollution - eutrophication (e.g. cyanotoxins, emanation of hydrogen sulphide, mercaptanes, methane...). Negative impact of nutrients excess in surface water often causes the destruction of water ecosystems, and therefore, common substances of these elements must be monitored and managed. For these experiments two spectrophotometric techniques - ultraviolet spectrophotometry and nutrient photometry were used. These techniques are commonly used for quick and simple analyses of nutrients in waste water. There are calibration curves for each nutrient and for determination of their concentration.

Cellulose Modifications and Their Future Application

USDA-ARS?s Scientific Manuscript database

In this poster, we will describe the synthesis and structural characterizations of a benzyl-, nitrobenzyl-, and aminobenzyl celluloses. Nitrobenzyl- and aminobenzyl cellulose derivatives are synthesized by etherification process in lithium chloride/N,N-dimethylacetamide homogeneous solution. Nitrobe...

40 CFR Appendix A to Part 423 - 126 Priority Pollutants

Code of Federal Regulations, 2012 CFR

2012-07-01

...-propylamin 064Pentachlorophenol 065Phenol 066Bis(2-ethylhexyl) phthalate 067Butyl benzyl phthalate 068Di-N-Butyl Phthalate 069Di-n-octyl phthalate 070Diethyl Phthalate 071Dimethyl phthalate 0721,2-benzanthracene...

40 CFR Appendix A to Part 423 - 126 Priority Pollutants

Code of Federal Regulations, 2014 CFR

2014-07-01

...-propylamin 064Pentachlorophenol 065Phenol 066Bis(2-ethylhexyl) phthalate 067Butyl benzyl phthalate 068Di-N-Butyl Phthalate 069Di-n-octyl phthalate 070Diethyl Phthalate 071Dimethyl phthalate 0721,2-benzanthracene...

40 CFR Appendix A to Part 423 - 126 Priority Pollutants

Code of Federal Regulations, 2010 CFR

2010-07-01

...-propylamin 064Pentachlorophenol 065Phenol 066Bis(2-ethylhexyl) phthalate 067Butyl benzyl phthalate 068Di-N-Butyl Phthalate 069Di-n-octyl phthalate 070Diethyl Phthalate 071Dimethyl phthalate 0721,2-benzanthracene...

40 CFR Appendix A to Part 423 - 126 Priority Pollutants

Code of Federal Regulations, 2011 CFR

2011-07-01

...-propylamin 064Pentachlorophenol 065Phenol 066Bis(2-ethylhexyl) phthalate 067Butyl benzyl phthalate 068Di-N-Butyl Phthalate 069Di-n-octyl phthalate 070Diethyl Phthalate 071Dimethyl phthalate 0721,2-benzanthracene...

77 FR 15101 - Results From Inert Ingredient Test Orders Issued Under EPA's Endocrine Disruptor Screening...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-03-14

... Federal Register document provides further notice. To help companies avoid formulating new product with methyl ethyl ketone, butyl benzyl phthalate, dibutyl phthalate, diethyl phthalate, and dimethyl phthalate...

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.

Porous Polystyrene Monoliths and Microparticles Prepared from Core Cross-linked Star (CCS) Polymers-Stabilized Emulsions.

PubMed

Chen, Qijing; Shi, Ting; Han, Fei; Li, Zihan; Lin, Chao; Zhao, Peng

2017-08-17

A hydrophobic CCS polymer of poly(benzyl methacrylate) (PBzMA) was prepared in toluene by reversible addition-fragmentation chain transfer (RAFT)-mediated dispersion polymerization. The CCS polymer, with poly(benzyl methacrylate) as the arm and crosslinked N, N'-bis(acryloyl)cystamine (BAC) as the core, was confirmed by characterization with gel permeation chromatography (GPC) and nuclear magnetic resonance (NMR) spectroscopy. Three kinds of oils (toluene, anisole and styrene) were chosen to study the emulsification properties of PBzMA CCS polymer. The oils can be emulsified by CCS polymer to form water-in-oil (w/o) emulsions. Moreover, w/o high internal phase emulsions (HIPEs) can be obtained with the increase of toluene and styrene volume fractions from 75% to 80%. Porous polystyrene monolith and microparticles were prepared from the emulsion templates and characterized by the scanning electronic microscopy (SEM). With the internal phase volume fraction increased, open-pore porous monolith was obtained.

The synthesis and crystal structure of 2-[4(S)-4,5-dihydro-4-phenyl-2-oxazolinyl]-benzenamine, and 2-[4(S)-4,5-dihydro-4-benzyl-2-oxazolinyl]-benzenamine

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

Mei Luo, E-mail: Lmhh5523385@yahoo.cn; Hai Zhangjia; Hao Yin

2010-12-15

Two oxazolines compound 1a and 1b, 2-[4(S)-4,5-dihydro-4-phenyl-2-ozazolinyl-benzenamine, and (C{sub 15}H{sub 14}N{sub 2}O), 2-[4(S)-4,5-dihydro-4-benzyl-2-ozazolinyl-benzenamine (C{sub 16}H{sub 16}N{sub 2}O) were obtained in moderate yield from the reactions of 2-aminobenzonitrile with optically active L-(+)-Phenylglycinol and L-(+)-Phenylalaninol, respectively, in chlorobenzene under dry, anaerobic conditions. ZnCl{sub 2} was dried under vacuum and acted as a Lewis acid catalyst in this reaction. The structures of 1a and 1b were determined by X-ray diffraction and NMR. There exist intra- and intermolecular N-H-N hydrogen bonds in the crystal structure.

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.

Antitumor and Antimicrobial Activity of Some Cyclic Tetrapeptides and Tripeptides Derived from Marine Bacteria

PubMed Central

Chakraborty, Subrata; Tai, Dar-Fu; Lin, Yi-Chun; Chiou, Tzyy-Wen

2015-01-01

Marine derived cyclo(Gly-l-Ser-l-Pro-l-Glu) was selected as a lead to evaluate antitumor-antibiotic activity. Histidine was chosen to replace the serine residue to form cyclo(Gly-l-His-l-Pro-l-Glu). Cyclic tetrapeptides (CtetPs) were then synthesized using a solution phase method, and subjected to antitumor and antibiotic assays. The benzyl group protected CtetPs derivatives, showed better activity against antibiotic-resistant Staphylococcus aureus in the range of 60–120 μM. Benzyl group protected CtetPs 3 and 4, exhibited antitumor activity against several cell lines at a concentration of 80–108 μM. However, shortening the size of the ring to the cyclic tripeptide (CtriP) scaffold, cyclo(Gly-l-Ser-l-Pro), cyclo(Ser-l-Pro-l-Glu) and their analogues showed no antibiotic or antitumor activity. This phenomenon can be explained from their backbone structures. PMID:25988520

(2E,5E)-2,5-Bis(4-hy­droxy-3-meth­oxy­benzyl­idene)cyclo­penta­none ethanol monosolvate

PubMed Central

Da’i, Muhammad; Yanuar, Arry; Meiyanto, Edy; Jenie, Umar Anggara; Supardjan, Amir Margono

2013-01-01

In the title structure, C21H20O5·C2H5OH, the curcumine-type mol­ecule has a double E conformation for the two benzyl­idene double bonds [C=C = 1.342 (4) and 1.349 (4) Å] and is nearly planar with respect to the non-H atoms (r.m.s. deviation from planarity = 0.069 Å). The two phenolic OH groups form bifurcated hydrogen bonds with intra­molecular branches to adjacent meth­oxy O atoms and inter­molecular branches to either a neighbouring mol­ecule or an ethanol solvent mol­ecule. The ethanol O atom donates a hydrogen bond to the keto O atom. These hydrogen bonds link the constituents into layers parallel to (101) in the crystal structure. PMID:23634071

Antitumor and antimicrobial activity of some cyclic tetrapeptides and tripeptides derived from marine bacteria.

PubMed

Chakraborty, Subrata; Tai, Dar-Fu; Lin, Yi-Chun; Chiou, Tzyy-Wen

2015-05-15

Marine derived cyclo(Gly-l-Ser-l-Pro-l-Glu) was selected as a lead to evaluate antitumor-antibiotic activity. Histidine was chosen to replace the serine residue to form cyclo(Gly-l-His-l-Pro-l-Glu). Cyclic tetrapeptides (CtetPs) were then synthesized using a solution phase method, and subjected to antitumor and antibiotic assays. The benzyl group protected CtetPs derivatives, showed better activity against antibiotic-resistant Staphylococcus aureus in the range of 60-120 μM. Benzyl group protected CtetPs 3 and 4, exhibited antitumor activity against several cell lines at a concentration of 80-108 μM. However, shortening the size of the ring to the cyclic tripeptide (CtriP) scaffold, cyclo(Gly-l-Ser-l-Pro), cyclo(Ser-l-Pro-l-Glu) and their analogues showed no antibiotic or antitumor activity. This phenomenon can be explained from their backbone structures.

Development of validated high-temperature reverse-phase UHPLC-PDA analytical method for simultaneous analysis of five natural isothiocyanates in cruciferous vegetables.

PubMed

Robin; Arora, Rohit; Arora, Saroj; Vig, Adarsh Pal

2018-01-15

In the present study reverse-phase UHPLC-PDA technique was developed at 60°C for simultaneous quantification of allyl, 3-butenyl, 4-(methylthio)butyl, benzyl and phenethyl isothiocyanates. The validation parameter showed a very good linearity, with a correlation coefficient of 1.00 for all detected standard analytes. Also, high precision and accuracy were observed with lowest obtained values of 1.39% and 99.1%, respectively. Different varieties of three plants, viz. Brassica rapa var. rapa L., Raphanus sativus L. var. oleiformis Pers. and Eruca sativa Mill., were analyzed with this method. After analysis, 4-(methylthio)butyl isothiocyanate was observed to be the major component in the varieties of arugula. Allyl, benzyl and phenethyl isothiocyanates were detected in turnip varieties and, in addition, 3-butenyl isothiocyanate was detected in radish varieties. Copyright © 2017 Elsevier Ltd. All rights reserved.

LASER APPLICATIONS AND OTHER TOPICS IN QUANTUM ELECTRONICS: Characterisation of optically cleared paper by optical coherence tomography

NASA Astrophysics Data System (ADS)

Fabritius, T.; Alarousu, E.; Prykäri, T.; Hast, J.; Myllylä, Risto

2006-02-01

Due to the highly light scattering nature of paper, the imaging depth of optical methods such as optical coherence tomography (OCT) is limited. In this work, we study the effect of refractive index matching on improving the imaging depth of OCT in paper. To this end, four different refractive index matching liquids (ethanol, 1-pentanol, glycerol and benzyl alcohol) with a refraction index between 1.359 and 1.538 were used in experiments. Low coherent light transmission was studied in commercial copy paper sheets, and the results indicate that benzyl alcohol offers the best improvement in imaging depth, while also being sufficiently stable for the intended purpose. Constructed cross-sectional images demonstrate visually that the imaging depth of OCT is considerably improved by optical clearing. Both surfaces of paper sheets can be detected along with information about the sheet's inner structure.

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

Gonzales, Ivana; Chung, Hoon Taek; Kim, Yu Seung

Slow hydrogen oxidation reaction (HOR) kinetics on Pt under alkaline conditions is a significant technical barrier for the development of high-performance hydroxide exchange membrane fuel cells. Here we report that benzene adsorption on Pt is a major factor responsible for the sluggish HOR. Furthermore, we demonstrate that bimetallic catalysts, such as PtMo/C, PtNi/C, and PtRu/C, can reduce the adsorption of benzene and thereby improve HOR activity. In particular, the HOR voltammogram of PtRu/C in 0.1 M benzyl ammonium showed minimal benzene adsorption. Density functional theory calculations indicate that the adsorption of benzyl ammonium on the bimetallic PtRu is endergonic formore » all four possible orientations of the cation, which explains the significantly better HOR activity observed for the bimetallic catalysts. In conclusion, the new HOR inhibition mechanism described here provides insights for the design of future polymer electrolytes and electrocatalysts for better-performing polymer membrane-based fuel cells.« less

Effects of Enterococcus faecium SLB 120 on growth performance, blood parameters, relative organ weight, breast muscle meat quality, excreta microbiota shedding, and noxious gas emission in broilers.

PubMed

Lan, R X; Lee, S I; Kim, I H

2017-09-01

This 5-week study was conducted to determine the effects of Enterococcus faecium (SLB 120) on growth performance, blood parameters, relative organ weight, breast muscle meat quality, excreta microbiota shedding, and noxious gas emission in broilers. A total of 816 one-day-old male broilers were allocated to 4 groups with 12 replications (17 broilers/pen) according to body weight (43.2 ± 0.32 g). Dietary treatment groups were: (1) CON, basal diet, (2) T1, CON + 0.05% E. faecium, (3) T2, CON + 0.10% E. faecium, (4) T3, CON + 0.20% E. faecium. From day 1 to 21, dietary E. faecium supplementation showed linear increase (P < 0.05) in gain:feed ratio. From day 21 to 35 and the overall period, dietary E. faecium supplementation showed a linear increase (P < 0.05) in body weight gain and gain:feed ratio. On day 35, dietary E. faecium supplementation showed a linear increase (P < 0.05) in the apparent total tract digestibility of dry matter and nitrogen, and the relative weight of bursa of Fabricius; no differences were observed in white blood cells, red blood cells or lymphocyte counts. Dietary E. faecium supplementation showed a linear decrease (P < 0.05) in excreta E.coli counts on day 7 and 35, while excreta Lactobacillus counts were linearly increased (P < 0.05) on day 35. On day 35, dietary E. faecium supplementation linearly decreased (P < 0.05) excreta NH3, H2S, and total mercaptans emission, but only H2S emission was linearly decreased (P < 0.05) on day 7. In conclusion, the supplementation of E. faecium improved growth performance, the digestibility of dry matter and nitrogen, the relative weight of bursa of Fabricius, and shifted excreta microbiota by increasing Lactobacillus and decreasing E.coli counts, as well as decreased excreta NH3, H2S, and total mercaptans gas emission. © 2017 Poultry Science Association Inc.

Necrotic enteritis challenge and high dietary sodium level affect odorant composition or emission from broilers.

PubMed

Sharma, Nishchal K; Choct, Mingan; Wu, Shu-Biao; Swick, Robert A

2018-01-01

Necrotic enteritis (NE) challenge and high dietary sodium (from sodium chloride) level on odor flux from broiler litter was investigated using 160 day-old Ross 308 male chicks randomly assigned to 4 dietary treatments with 4 replicates of 10 birds each. A 2 × 2 factorial arrangement of treatments was employed. Factors were: presence or absence of NE challenge and normal (1.6 g/kg) or high (4.0 g/kg) dietary sodium (Na) level. On d 20, odorants were collected from litter headspace with a flux hood and measured using selected ion flow tube mass spectrometry (SIFT-MS). On d 33, while challenge did not lead to higher mortality, it reduced feed intake by 5.48% (P < 0.05) and body weight gain by 9.02% (P < 0.01) and worsened FCR by 5 points (P < 0.01), indicating subclinical necrotic enteritis occurred in challenged birds. Challenge increased (P < 0.01) litter moisture and litter headspace concentrations of dimethyl sulfide (P < 0.05), propyl mercaptan (P < 0.05), total butanols (P < 0.05), acetoin (P < 0.01), skatole (P = 0.05), butyric acid (P < 0.05), and methyl amine (P < 0.05) and tended to increase concentrations of ethyl mercaptan (P = 0.07), carbon disulfide (P = 0.09), indole (P = 0.10), and formic acid (P = 0.10) compared to the unchallenged group. The birds fed a high Na diet produced higher litter moisture (P < 0.01) and higher litter headspace concentration of sulfur compounds and phenol (P < 0.01) compared to those fed a normal Na diet. In the birds fed a high Na diet, challenge increased the litter flux of some additional odorants, which included 2,3-butanedione (P < 0.05), acetic acid (P < 0.01), propionic acid (P < 0.01), isobutyric acid (P < 0.01), isovaleric acid (P < 0.01), pentanoic acid (P < 0.05), 2-butanone (P < 0.05), and 3-methyl-1-butanol (P < 0.05). These findings suggest that both a high Na diet and sub-clinical NE increase the odor nuisance potential of broiler farms. © 2017 Poultry Science Association Inc.

Enantiomerically Enriched α-Methyl Amino Acids. Use of an Acyclic, Chiral Alanine-Derived Dianion with a High Diastereofacial Bias.†

PubMed Central

Berkowitz, David B.; Smith, Marianne K.

2018-01-01

Hindered esters derived from N-benzoylalanine and the following chiral alcohols have been synthesized: (1) (−)-isopinocampheol; (2) (−)-trans-2-phenylcyclohexanol and (3) (−)-8-phenylmenthol. Sequential treatment of these esters with LDA (1.2 equiv.) and n-butyllithium (2.4 equiv.) at −78°C in THF generates the corresponding chiral dianions. Alkylation of each of these with benzyl bromide reveals that only the (−)-8-phenylmenthyl auxiliary confers a high diastereofacial bias upon its derivative dianion. In fact, that dianion (6) consistently displays diastereomeric ratios in the range of 89:11 to 94:6 for alkylations with a spectrum of nine alkyl halides. If one recrystallization step is included, a single diastereomeric product may be obtained, as is demonstrated for the benzylation of 6. Of particular note, the alkylation with 3,4-bis(tert-butyldimethylsilyloxy)benzyl bromide (18) (94:6 diast. ratio, 72% yield) constitutes a formal synthesis of the clinically important antihypertensive (S)-α-methyl-DOPA (Aldomet), in enantiomerically enriched from. In all cases studied, yields are markedly improved, yet diastereoselectivities unchanged, by the addition of 10% HMPA to the reaction milieu. The (−)-8-phenylmenthol chiral auxiliary is conveniently recovered via ester cleavage with KO2/18-crown-6, following alkylation. Complete deprotection affords enantiomerically enriched (S)-α-methyl amino acids, in all cases examined, indicating that dianion 6 displays a substantial bias in favor of si face alkylation. This sense of diastereoselection is consistent with a chain-extended, internal chelate model for the reactive conformation of the dianion.

The algicidal activity of Aeromonas sp. strain GLY-2107 against bloom-forming Microcystis aeruginosa is regulated by N-acyl homoserine lactone-mediated quorum sensing.

PubMed

Guo, Xingliang; Liu, Xianglong; Wu, Lishuang; Pan, Jianliang; Yang, Hong

2016-11-01

Cyanobacterial blooms have disrupted the efficient utilization of freshwater worldwide. A new freshwater bacterial strain with strong algicidal activity, GLY-2107, was isolated from Lake Taihu and identified as Aeromonas sp. It produced two algicidal compounds: 2107-A (3-benzyl-piperazine-2,5-dione) and 2107-B (3-methylindole). Both compounds exhibited potent algicidal activities against Microcystis aeruginosa, the dominant bloom-forming cyanobacterium in Lake Taihu. The EC 50 values (concentration for 50% maximal effect) of 3-benzyl-piperazine-2,5-dione and 3-methylindole were 4.72 and 1.10 μg ml -1 respectively. Based on a thin-layer chromatography biosensor assay and ultra-performance liquid chromatography-coupled high resolution-tandem mass spectrometry (UPLC-HRMS/MS), the N-acyl homoserine lactone (AHL) profile of strain GLY-2107 was identified as two short side-chain AHLs: N-butyryl-homoserine lactone (C4-HSL) and N-hexanoyl-homoserine lactone (C6-HSL). The production of the two algicidal compounds was controlled by AHL-mediated quorum sensing (QS), and C4-HSL was the key QS signal for the algicidal activity of the strain GLY-2107. Moreover, 3-methylindole was found to be positively regulated by C4-HSL-mediated QS, whereas 3-benzyl-piperazine-2,5-dione might be negatively controlled by C4-HSL-mediated QS. This study suggests that a QS-regulated algicidal system may have potential use for the development of a novel control strategy for harmful cyanobacterial blooms. © 2016 Society for Applied Microbiology and John Wiley & Sons Ltd.

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

Pd/Cu-Oxide Nanoconjugate at Zeolite-Y Crystallite Crafting the Mesoporous Channels for Selective Oxidation of Benzyl-Alcohols.

PubMed

Sharma, Mukesh; Das, Biraj; Sharma, Mitu; Deka, Biplab K; Park, Young-Bin; Bhargava, Suresh K; Bania, Kusum K

2017-10-11

Solid-state grinding of palladium and copper salts allowed the growth of palladium/copper oxide interface at the zeolite-Y surface. The hybrid nanostructured material was used as reusable heterogeneous catalyst for selective oxidation of various benzyl alcohols. The large surface area provided by the zeolite-Y matrix highly influenced the catalytic activity, as well as the recyclability of the synthesized catalyst. Impregnation of PdO-CuO nanoparticles on zeolite crystallite leads to the generation of mesoporous channel that probably prevented the leaching of the metal-oxide nanoparticles and endorsed high mass transfer. Formation of mesoporous channel at the external surface of zeolite-Y was evident from transmission electron microscopy and surface area analysis. PdO-CuO nanoparticles were found to be within the range of 2-5 nm. The surface area of PdO-CuO-Y catalyst was found to be much lower than parent zeolite-Y. The decrease in surface area as well as the presence of hysteresis loop in the N 2 -adsoprtion isotherm further suggested successful encapsulation of PdO-CuO nanoparticles via the mesoporous channel formation. The high positive shifting in binding energy in both Pd and Cu was attributed to the influence of zeolite-Y framework on lattice contraction of metal oxides via confinement effect. PdO-CuO-Y catalyst was found to oxidize benzyl alcohol with 99% selectivity. On subjecting to microwave irradiation the same oxidation reaction was found to occur at ambient condition giving same conversion and selectivity.

Synthesis, Characterization, and Bioactivity of Schiff Bases and Their Cd2+, Zn2+, Cu2+, and Ni2+ Complexes Derived from Chloroacetophenone Isomers with S-Benzyldithiocarbazate and the X-Ray Crystal Structure of S-Benzyl-β-N-(4-chlorophenyl)methylenedithiocarbazate

PubMed Central

Break, Mohammed Khaled bin; Tahir, M. Ibrahim M.; Crouse, Karen A.; Khoo, Teng-Jin

2013-01-01

Two bidentate Schiff base ligands having nitrogen sulphur donor sequence were derived from the condensation of S-benzyldithiocarbazate (SBDTC) with 2-chloroacetophenone and 4-chloroacetophenone to give S-benzyl-β-N-(2-chlorophenyl)methylenedithiocarbazate (NS2) and S-benzyl-β-N-(4-chlorophenyl)methylenedithiocarbazate (NS4) isomers. Each of the ligands was then chelated with Cd2+, Zn2+, Cu2+, and Ni2+. The compounds were characterized via IR spectroscopy and melting point while the structure of NS4 was revealed via X-ray crystallography. Finally, the compounds were screened for antimicrobial activity to investigate the effect that is brought by the introduction of the chlorine atom to the benzene ring. X-ray crystallographic analysis showed that the structure of NS4 is planar with a phenyl ring that is nearly perpendicular to the rest of the molecules. The qualitative antimicrobial assay results showed that NS4 and its complexes lacked antifungal activity while Gram-positive bacteria were generally inhibited more strongly than Gram-negative bacteria. Furthermore, NS4 metal complexes were inhibited more strongly than the ligand while the opposite was seen with NS2 ligand and its complexes due to the partial solubility in dimethyl sulfoxide (DMSO). It was concluded that generally NS2 derivatives have higher bioactivity than that of NS4 derivatives and that the Cd complexes of both ligands have pronounced activity specifically on K. rhizophila. PMID:24319401

Inhibition of lipopolysaccharide-induced cyclooxygenase-2 expression and inducible nitric oxide synthase by 4-[(2′-O-acetyl-α-l-rhamnosyloxy)benzyl]isothiocyanate from Moringa oleifera

PubMed Central

Park, Eun-Jung; Cheenpracha, Sarot; Chang, Leng Chee; Kondratyuk, Tamara P.; Pezzuto, John M.

2011-01-01

Moringa oleifera Lamarack is commonly consumed for nutritional or medicinal properties. We recently reported the isolation and structure elucidation of novel bioactive phenolic glycosides, including 4-[(2′-O-acetyl-α-l-rhamnosyloxy)benzyl]isothiocyanate (RBITC), which was found to suppress inducible nitric oxide synthase (iNOS) expression and nitric oxide production in lipopolysaccharide-stimulated RAW 264.7 mouse macrophage cells. Inhibitors of proteins such as cyclooxygenase-2 (COX-2) and iNOS are potential anti-inflammatory and cancer chemopreventive agents. The inhibitory activity of RBITC on NO production (IC50 = 0.96 ± 0.23 µM) was greater than that mediated by other well-known isothiocyanates such as sulforaphane (IC50 = 2.86 ± 0.39 µM) and benzyl isothiocyanate (IC50 = 2.08 ± 0.28 µM). RBITC inhibited expression of COX-2 and iNOS at both the protein and mRNA levels. Major upstream signaling pathways involved mitogen-activated protein kinases and nuclear factor-κB (NF-κB). RBITC inhibited phosphorylation of extracellular signal regulated kinase and stress-activated protein kinase, as well as ubiquitin-dependent degradation of inhibitor κBα (IκBα). In accordance with IκBα degradation, nuclear accumulation of NF-κB, and subsequent binding to NF-κB cis-acting element, was attenuated by treatment with RBITC. These data suggest RBITC should be included in the dietary armamentarium of isothiocyanates potentially capable of mediating anti-inflammatory or cancer chemopreventive activity. PMID:21774591

PM101: a cyclodextrin-based intravenous formulation of amiodarone devoid of adverse hemodynamic effects.

PubMed

Cushing, Daniel J; Kowey, Peter R; Cooper, Warren D; Massey, Bill W; Gralinski, Michael R; Lipicky, Raymond J

2009-04-01

Intravenous amiodarone (Amiodarone i.v.) is widely used to treat cardiac arrhythmias. The most frequent clinical adverse event associated with Amiodarone i.v. administration is systemic hypotension which has been attributed to the cosolvents used in the formulation, polysorbate 80 and benzyl alcohol. To minimize hypotension Amiodarone i.v. is diluted in 5% dextrose in water prior to administration and slowly infused. PM101 is a novel intravenous formulation that uses sulfobutylether-7-beta-cyclodextrin to solubilize amiodarone, and thus should be devoid of the untoward hemodynamic effects associated with polysorbate 80 and benzyl alcohol. Beagle dogs (n=7/group) were anesthetized with morphine and alpha-chloralose and instrumented to assess aortic blood pressure, cardiac output, cardiac contractility, and heart rate. Animals were treated with the U.S. approved human-equivalent loading dose (2.14 mg/kg) of Amiodarone i.v., PM101, and their respective vehicle controls. Administration of Amiodarone i.v. rapidly and significantly decreased mean aortic pressure, cardiac output, and cardiac contractility. A significant increase in heart rate was also observed as was a transient, but not significant, decrease in systemic vascular resistance. A similar pattern of rapid and significant hemodynamic changes was produced by the Amiodarone i.v. Vehicle (polysorbate 80/benzyl alcohol) alone. In marked contrast, PM101 and its vehicle produced no significant hemodynamic effects. This study provides a useful model for the continued search for a safe and effective intravenous amiodarone formulation devoid of the hypotensive risk associated with the current commercial formulation.

Evaluation and Development of Radiation Countermeasures at AFRRI

DTIC Science & Technology

2005-01-01

epigallocatechin gallate ( EGCG ), benzyl styryl sulfones, CpG oligonucleotides, a superoxide dismutase mi- metic, statins, dipeptidyl peptidase inhibitors, and...candidate (Hollis-Eden Pharmaceuticals) • Soy isoflavones • Vitamin E-related compounds (Yasoo Health) • Phenylacetate, phenylbutyrate, EGCG (late

A fuzzy logic approach to control anaerobic digestion.

PubMed

Domnanovich, A M; Strik, D P; Zani, L; Pfeiffer, B; Karlovits, M; Braun, R; Holubar, P

2003-01-01

One of the goals of the EU-Project AMONCO (Advanced Prediction, Monitoring and Controlling of Anaerobic Digestion Process Behaviour towards Biogas Usage in Fuel Cells) is to create a control tool for the anaerobic digestion process, which predicts the volumetric organic loading rate (Bv) for the next day, to obtain a high biogas quality and production. The biogas should contain a high methane concentration (over 50%) and a low concentration of components toxic for fuel cells, e.g. hydrogen sulphide, siloxanes, ammonia and mercaptanes. For producing data to test the control tool, four 20 l anaerobic Continuously Stirred Tank Reactors (CSTR) are operated. For controlling two systems were investigated: a pure fuzzy logic system and a hybrid-system which contains a fuzzy based reactor condition calculation and a hierachial neural net in a cascade of optimisation algorithms.

Ignition Delay Experiments with Small-scale Rocket Engine at Simulated Altitude Conditions Using Various Fuels with Nitric Acid Oxidants / Dezso J. Ladanyi

NASA Technical Reports Server (NTRS)

Ladanyi, Dezso J

1952-01-01

Ignition delay determinations of several fuels with nitric oxidants were made at simulated altitude conditions utilizing a small-scale rocket engine of approximately 50 pounds thrust. Included in the fuels were aniline, hydrazine hydrate, furfuryl alcohol, furfuryl mercaptan, turpentine, and mixtures of triethylamine with mixed xylidines and diallyaniline. Red fuming, white fuming, and anhydrous nitric acids were used with and without additives. A diallylaniline - triethylamine mixture and a red fuming nitric acid analyzing 3.5 percent water and 16 percent NO2 by weight was found to have a wide temperature-pressure ignition range, yielding average delays from 13 milliseconds at 110 degrees F to 55 milliseconds at -95 degrees F regardless of the initial ambient pressure that ranged from sea-level pressure altitude of 94,000 feet.

PROCESS INTENSIFICATION: OXIDATION OF BENZYL ALCOHOL USING A CONTINUOUS ISOTHERMAL REACTOR UNDER MICROWAVE IRRADIATION

EPA Science Inventory

In the past two decades, several investigations have been carried out using microwave radiation for performing chemical transformations. These transformations have been largely performed in conventional batch reactors with limited mixing and heat transfer capabilities. The reacti...

HEALTH AND ENVIRONMENTAL EFFECTS DOCUMENT FOR BENZYL ALCOHOL

EPA Science Inventory

Health and Environmental Effects Documents (HEEDS) are prepared for the Office of Solid Waste and Emergency Response (OSWER). his document series is intended to support listings under the Resource Conservation and Recovery Act (RCRA) as well as to provide health-related limits an...

Potential development of a new cotton-based antimicrobial wipe

USDA-ARS?s Scientific Manuscript database

The adsorption of alkyl-dimethyl-benzyl-ammonium chloride (ADBAC), a cationic surfactant commonly employed as an antimicrobial agent, on greige and bleached nonwoven cotton fabrics was investigated using UV/visible spectroscopy. Initial results have shown that greige cotton adsorbs roughly three tim...

USDA research enables total quat release from cotton nonwoven disinfecting wipes

USDA-ARS?s Scientific Manuscript database

The adsorption of alkyl-dimethyl-benzyl-ammonium chloride (ADBAC), a cationic surfactant commonly employed as an antimicrobial agent, on various cotton, cotton-blend, and synthetic nonwoven fabrics was investigated at varying surfactant concentrations using UV-Vis absorption spectroscopy. Modifying ...

Analytical characterization of bioactive N-benzyl-substituted phenethylamines and 5-methoxytryptamines.

PubMed

Brandt, Simon D; Elliott, Simon P; Kavanagh, Pierce V; Dempster, Nicola M; Meyer, Markus R; Maurer, Hans H; Nichols, David E

2015-04-15

Substances based on the N-(2-methoxybenzyl)phenethylamine template ('NBOMe' derivatives) play an important role in medicinal research but some of these derivatives have also appeared as 'research chemicals' for recreational use which has attracted attention worldwide. A major challenge associated with newly emerging substances includes the lack of analytical data and the ability to correctly identify positional isomers. Six N-benzylphenethylamines based on the 2,5-dimethoxy-4-iodophenethylamine structure ('25I') and twelve substituted N-benzyl-5-methoxytryptamines ('5MT') have been prepared and extensively characterized. Techniques used for characterization were gas chromatography/ion trap mass spectrometry in electron and chemical ionization mode, liquid chromatography/diode array detection (DAD), infrared spectroscopy, electrospray high mass accuracy quadrupole time-of-flight tandem mass spectrometry, and triple quadrupole tandem mass spectrometry. The characterization of 18 'NBOMe' compounds provided a comprehensive collection of chromatographic and spectral data. Four groups of three positional isomers, i.e. 25I-NB2OMe, 25I-NB3OMe, 25I-NB4OMe, 25I-NB2B, 25I-NB3B, 25I-NB4B and their 5-methoxytryptamine counterparts, were included and assessed for ability to obtain differentiation. Six meta-substituted N-benzyl derivatives of 5-methoxytryptamine (CF3, F, CH3, Cl, I, SCH3) were also studied. The implementation of mass spectral techniques was helpful for the differentiation between isomers, for example, when considering the difference in a number of ion ratios. This was considered beneficial in cases where chromatographic separation was only partially achieved under liquid chromatography (LC) conditions. The use of LC/DAD analysis was also found to be valuable for this particular purpose, which confirmed the integrative value of complementary techniques used in areas related to forensic toxicology. Copyright © 2015 John Wiley & Sons, Ltd.

New acyclic secondary metabolites from the biologically active fraction of Albizia lebbeck flowers.

PubMed

Al-Massarani, Shaza M; El Gamal, Ali A; Abd El Halim, Mohamed F; Al-Said, Mansour S; Abdel-Kader, Maged S; Basudan, Omer A; Alqasoumi, Saleh I

2017-01-01

The total extract of Albizia lebbeck flowers was examined in vivo for its possible hepatoprotective activity in comparison with the standard drug silymarin at two doses. The higher dose expressed promising activity especially in reducing the levels of AST, ALT and bilirubin. Fractionation via liquid-liquid partition and reexamination of the fractions revealed that the n -butanol fraction was the best in improving liver biochemical parameters followed by the n -hexane fraction. However, serum lipid parameters were best improved with CHCl 3 fraction. The promising biological activity results initiated an intensive chromatographic purification of A. lebbeck flowers fractions. Two compounds were identified from natural source for the first time, the acyclic farnesyl sesquiterpene glycoside1-O-[6-O- α -l-arabinopyranosyl- β -d-glucopyranoside]-(2 E ,6 E -)-farnesol ( 6 ) and the squalene derivative 2,3-dihydroxy-2,3-dihydrosqualene ( 9 ), in addition to eight compounds reported here for the first time from the genus Albizia ; two benzyl glycosides, benzyl 1-O- β -d-glucopyranoside ( 1 ) and benzyl 6-O- α -l-arabinopyranosyl β -d-glucopyranoside ( 2 ); three acyclic monoterpene glycosides, linalyl β -d-glucopyranoside ( 3 ) and linalyl 6-O- α -l-arabinopyranosyl- β -d-glucopyranoside ( 4 ); (2 E )-3,7-dimethylocta-2,6-dienoate-6-O- α -l arabinopyranosyl- β -d-glucopyranoside ( 5 ), two oligoglycosides, n -hexyl- α -l arabinopyranosyl-(1 → 6)- β -d-glucopyranoside (creoside) ( 7 ) and n -octyl α -l-arabinopyranosyl-(1 → 6)- β -d-glucopyranoside (rhodiooctanoside) ( 8 ); and ethyl fructofuranoside ( 10 ). The structures of the isolated compounds were elucidated based on extensive examination of their spectroscopic 1D and 2D-NMR, MS, UV, and IR data. It is worth mentioning that, some of the isolated linalol glycoside derivatives were reported as aroma precursors.

Syntheses and molecular structures of novel Ru(II) complexes with bidentate benzimidazole based ligands and their catalytic efficiency for oxidation of benzyl alcohol

NASA Astrophysics Data System (ADS)

Dayan, Osman; Tercan, Melek; Özdemir, Namık

2016-11-01

Five bidentate ligands derived from quinoline-2-carboxylic acid, i.e. 2-(1H-benzimidazol-2-yl)quinoline (L1), 2-(1-benzyl-1H-benzimidazol-2-yl)quinoline (L2), 2-[1-(2,3,5,6-tetramethylbenzyl)-1H-benzimidazol-2-yl]quinoline (L3), 2-[1-(4-chlorobenzyl)-1H-benzimidazol-2-yl]quinoline (L4), and 2-[1-(4-methylbenzyl)-1H-benzimidazol-2-yl]quinoline (L5) were synthesized. Treatment of L1-5 with [RuCl2(p-cymene)]2 and KPF6 afforded six-coordinate piano-stool Ru(II) complexes, namely, [RuCl(L1)(p-cymene)]PF6 (C1), [RuCl(L2)(p-cymene)]PF6 (C2), [RuCl(L3)(p-cymene)]PF6 (C3), [RuCl(L4)(p-cymene)]PF6 (C4), and [RuCl(L5)(p-cymene)]PF6 (C5). Synthesized compounds were characterized with different techniques such as 1H and 13C NMR, FT-IR, and UV-vis spectroscopy. The solid state structure of L1 and C3 was confirmed by single-crystal X-ray diffraction analysis. The single crystal structure of C3 verified coordination of L3 to the Ru(II) center. The Ru(II) center has a pseudo-octahedral three legged piano stool geometry. The complexes C1-5 were tested as catalysts for the catalytic oxidation of benzyl alcohol to benzaldehyde in the presence of periodic acid (H5IO6) (Substrate/Catalyst/Oxidant = 1/0.01/0.5). The best result was obtained with C2 (3 h→90%).

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.

TiO2@Pt@CeO2 nanocomposite as a bifunctional catalyst for enhancing photo-reduction of Cr (VI) and photo-oxidation of benzyl alcohol.

PubMed

Li, Shunxing; Cai, Jiabai; Wu, Xueqing; Liu, Biwen; Chen, Qiaoying; Li, Yuehai; Zheng, Fengying

2018-03-15

An solar-light-driven and bifunctional photocatalyst was designed for photo-reduction of Cr(VI) and selective photo-oxidation of benzyl alcohol into benzaldehyde in the presence of water under ambient conditions. Double-shelled and sandwiched TiO 2 @Pt@CeO 2 hollow spheres were prepared by using functionalized polystyrene spheres, sol-gel, hydrothermal reaction, and calcination. The Pt nanoparticles (NPs) were controllably loaded between the TiO 2 shell and CeO 2 shell. Under solar-light irradiation, the photo-reduction rate of Cr(VI) (μmol h -1 ) was in the order of TiO 2 @Pt@CeO 2 (1.901) > TiO 2 @CeO 2 (1.424) > TiO 2 (1.040) > CeO 2 (0.992). Among the above-mentioned photocatalysts, the conversion rate of benzyl alcohol for TiO 2 @Pt@CeO 2 was also the best. These results were attributed to the combination of TiO 2 and CeO 2 as photocatalyst and oxygen buffer, the double-shelled and sandwiched nanostructure, and the addition of Pt NPs as cocatalyst and electron trap site, which could store and shuttle photo-generated electrons, reduce the recombination of the electron-hole, and then enhance photo-generation of active radicals. This conclusion was verified by the electron paramagnetic resonance (EPR) spectroscopy. Considering the versatile combination of photocatalyst, oxygen buffer and cocatalyst, this work could provide new insights into the design of high-performance bifunctional photocatalysts for heavy metal removal and selective synthesis. Copyright © 2017 Elsevier B.V. All rights reserved.

Phytotoxic Effects and Phytochemical Fingerprinting of Hydrodistilled Oil, Enriched Fractions, and Isolated Compounds Obtained from Cryptocarya massoy (Oken) Kosterm. Bark.

PubMed

Rolli, Enrico; Marieschi, Matteo; Maietti, Silvia; Guerrini, Alessandra; Grandini, Alessandro; Sacchetti, Gianni; Bruni, Renato

2016-01-01

The hydrodistilled oil of Cryptocarya massoy bark was characterized by GC-FID and GC/MS analyses, allowing the identification of unusual C10 massoia lactone (3, 56.2%), C12 massoia lactone (4, 16.5%), benzyl benzoate (1, 12.7%), C8 massoia lactone (3.4%), δ-decalactone (5, 1.5%), and benzyl salicylate (2, 1.8%) as main constituents. The phytotoxic activities of the oil, three enriched fractions (lactone-rich, ester-rich, and sesquiterpene-rich), and four constituents (compounds 1, 2, 5, and δ-dodecalactone (6)) against Lycopersicon esculentum and Cucumis sativus seeds and seedlings were screened. At a concentration of 1000 μl/l, the essential oil and the massoia lactone-rich fraction caused a complete inhibition of the germination of both seeds, and, when applied on tomato plantlets, they induced an 85 and 100% dieback, respectively. These performances exceeded those of the well-known phytotoxic essential oils of Syzygium aromaticum and Cymbopogon citratus, already used in commercial products for the weed and pest management. The same substances were also evaluated against four phytopathogenic bacteria and ten phytopathogenic fungi, providing EC50 values against the most susceptible strains in the 100-500 μl/l range for the essential oil and in the 10-50 μl/l range for compound 6 and the lactone-rich fraction. The phytotoxic behavior was related mainly to massoia lactones and benzyl esters, while a greater amount of 6 may infer a good activity against some phytopathogenic fungi. Further investigations of these secondary metabolites are warranted, to evaluate their use as natural herbicides. Copyright © 2016 Verlag Helvetica Chimica Acta AG, Zürich.

GC/GCMS analysis of the petroleum ether and dichloromethane extracts of Moringa oleifera roots

PubMed Central

Faizi, Shaheen; Sumbul, Saima; Versiani, Muhammed Ali; Saleem, Rubeena; Sana, Aisha; Siddiqui, Hira

2014-01-01

Objective To explore the phytochemical constituents from petroleum ether and dichloromethane extracts of Moringa oleifera (M. oleifera) roots using GC/GC-MS. Methods A total of 5.11 kg fresh and undried crushed root of M. oleifera were cut into small pieces and extracted with petroleum ether and dichloromethane (20 L each) at room temperature for 2 d. The concentrated extracts were subjected to their GC-MS analysis. Results The GC-MS analysis of the petroleum ether and dichloromethane extracts of M. oleifera roots, which showed promising biological activities, has resulted in the identification 102 compounds. These constituents belong to 15 classes of compounds including hydrocarbons, fatty acids, esters, alcohols, isothiocyanate, thiocyanate, pyrazine, aromatics, alkamides, cyanides, steroids, halocompounds, urea and N-hydroxyimine derivatives, unsaturated alkenamides, alkyne and indole. GC/GC-MS studies on petroleum ether extract of the roots revealed that it contained 39 compounds, belonging to nine classes. Cyclooctasulfur S8 has been isolated as a pure compound from the extract. The major compounds identified from petroleum ether extract were trans-13-docosene (37.9%), nonacosane (32.6%), cycloartenol (28.6%) nonadecanoic acid (13.9%) and cyclooctasulfur S8 (13.9%). Dichloromethane extract of the roots was composed of 63 compounds of which nasimizinol (58.8%) along with oleic acid (46.5%), N-benzyl-N-(7-cyanato heptanamide (38.3%), N-benzyl-N-(1-chlorononyl) amide (30.3%), bis [3-benzyl prop-2-ene]-1-one (19.5%) and N, N-dibenzyl-2-ene pent 1, 5-diamide (11.6%) were the main constituents. Conclusions This study helps to predict the formula and structure of active molecules which can be used as drugs. This result also enhances the traditional usage of M. oleifera which possesses a number of bioactive compounds. PMID:25183335

Heparin-benzyl alcohol enhancement of biofilms formation and antifungal susceptibility of vaginal Candida species isolated from pregnant and nonpregnant Saudi women

PubMed Central

Al-akeel, Raid A; El-kersh, Talat A; Al-Sheikh, Yazeed A; Al-Ahmadey, Ziab Zakey

2013-01-01

Biofilm formation by Candida species is a major contribute to their pathogenic potential.The aim of this study was to determine in vitro effects of EDTA, cycloheximide, and heparin-benzyl alcohol preservative on C. albicans (126) and non-albicans (31)vaginal yeast isolates biofilm formations and their susceptibility against three antifungal Etest strips. Results of the crystal violet-assay, indicated that biofilms formation were most commonly observed [100%] for C. kefyr, C. utilis, C. famata, and Rhodotorula mucilaginosa, followed by C. glabrata [70%], C. tropicalis [50%], C. albicans [29%], Saccharomyces cerevisiae [0.0%]. EDTA (0.3mg/ml) significantly inhibited biofilm formation in both C. albicans and non-albicans isolates (P=0.0001) presumably due to chelation of necessary metal cations for the process-completion. In contrast, heparin (-benzyl alcohol preservative) stimulated biofilm formation in all tested isolates, but not at significant level (P=0.567). Conversely, cycloheximide significantly (P=0.0001) inhibited biofilm formation in all C. albicans strains(126) and its effect was even 3 fold more pronounced than EDTA inhibition, probably due to its attenuation of proteins (enzymes) and/or complex molecules necessary for biofilm formation. Results also showed that all nonalbicans yeasts isolates were susceptible to 5-flucytosine (MIC50, 0.016 µg/ml; MIC90, 0.064 µg/ml), but 14% of C. albicans isolates were resistant (MIC50, 0.064 µg/ml; MIC90 >32 µg/ml). The MIC50 value of amphotricin B for all C. albicans and non-albicans isolates was at a narrow range of 0.023 µg /ml, and the MIC90 values were 0.047 µg/ml and 0.064 µg/ml respectively, thereby confirming its efficacy as a first line empiric- treatment of Candida spp infections. PMID:23750080

Defect-rich Ni-Ti layered double hydroxide as a highly efficient support for Au nanoparticles in base-free and solvent-free selective oxidation of benzyl alcohol.

PubMed

Liu, Mengran; Fan, Guoli; Yu, Jiaying; Yang, Lan; Li, Feng

2018-04-17

Tuning the surface properties of supported metal catalysts is of vital importance for governing their catalytic performances in nanocatalysis. Here, we report highly dispersed nanometric gold nanoparticles (NPs) supported on Ni-Ti layered double hydroxides (NiTi-LDHs), which were employed in solvent-free and base-free selective oxidation of benzyl alcohol. A series of characterization techniques demonstrated that defect-rich NiTi-LDHs could efficiently stabilize Au NPs and decrease surface electron density of Au NPs. The as-formed Au/NiTi-LDH catalyst with a Ni/Ti molar ratio of 3 : 1 and an Au loading of 0.71 wt% yielded the highest turnover frequency value of ∼4981 h-1 at 120 °C among tested Au/NiTi-LDH catalysts with different Ni/Ti molar ratios, along with a high benzaldehyde selectivity of 98%. High catalytic efficiency of the catalyst was mainly correlated with surface cooperation between unique defects (i.e. defective Ti3+ species and oxygen vacancies) and abundant hydroxyl groups on the brucite-like layers of the NiTi-LDH support, which could lead to the preferential adsorption and activation of an alcohol hydroxyl moiety in benzyl alcohol and oxygen molecule, as well as the formation of more electron-deficient Ni3+ and Au0 species on the catalyst surface. Furthermore, the present Au/NiTi-LDH catalyst tolerated the oxidation of a wide variety of substrate structures into the corresponding aldehydes, acids or ketones. Our primary results illustrate that defect-rich NiTi-LDHs are promising supports which can efficiently modify surface structure and electronic properties of supported metal catalysts and consequently improve their catalytic performances.

Bioresorbable polypeptide-based comb-polymers efficiently improves the stability and pharmacokinetics of proteins in vivo.

PubMed

Turabee, Md Hasan; Thambi, Thavasyappan; Lym, Jae Seung; Lee, Doo Sung

2017-03-28

Stimuli-responsive polypeptides are a promising class of biomaterials due to their tunable physicochemical and biological properties. Herein, a series of novel pH- and thermo-responsive block copolymers based on polypeptides were synthesized by ring-opening polymerization of γ-benzyl-l-glutamate-N-carboxyanhydride in the presence of poly(ethylene glycol)-diamine macroinitiator followed by aminolysis. The resulting polypeptide-based triblock copolymer, poly[(2-(dibutylamino)ethyl-l-glutamate)-co-(γ-benzyl-l-glutamate)]-poly(ethylene glycol)-b-poly[(2-(dibutylamino)ethyl-l-glutamate)-co-(γ-benzyl-l-glutamate)] (PNLG-co-PBLG-b-PEG-b-PBLG-co-PNLG), exists as a low viscous sol at low pH and temperature (≤pH 6.4, 25 °C) but it transforms to a soft gel under physiological conditions (pH 7.4 and 37 °C). The physical properties of the polypeptide gel can be tuned by controlling the ratio between hydrophobic PBLG and pH-sensitive PNLG blocks. The polypeptide-based copolymer did not show any noticeable cytotoxicity to fibroblast cells in vitro. It was found that subcutaneous injection of the polypeptide copolymer solution into the dorsal region of Sprague-Dawley (SD) rats formed a gel instantly without major inflammation. The gels were completely biodegraded in six weeks and found to be bioresorbable. Human growth hormone (hGH)-loaded polypeptide-based biodegradable copolymer sols readily formed a viscoelastic gel that inhibited an initial burst and prolonged the hGH release for one week. Overall, due to their bioresorbable and sustained release protein characteristics, polypeptide hydrogels may serve as viable platforms for therapeutic protein delivery and the surface tunable properties of polypeptide hydrogels can be exploited for other potential therapeutic proteins.

Substituent Effects on the Self-Assembly/Coassembly and Hydrogelation of Phenylalanine Derivatives.

PubMed

Liyanage, Wathsala; Nilsson, Bradley L

2016-01-26

Supramolecular hydrogels derived from the self-assembly of organic molecules have been exploited for applications ranging from drug delivery to tissue engineering. The relationship between the structure of the assembly motif and the emergent properties of the resulting materials is often poorly understood, impeding rational approaches for the creation of next-generation materials. Aromatic π-π interactions play a significant role in the self-assembly of many supramolecular hydrogelators, but the exact nature of these interactions lacks definition. Conventional models that describe π-π interactions rely on quadrupolar electrostatic interactions between neighboring aryl groups in the π-system. However, recent experimental and computational studies reveal the potential importance of local dipolar interactions between elements of neighboring aromatic rings in stabilizing π-π interactions. Herein, we examine the nature of π-π interactions in the self- and coassembly of Fmoc-Phe-derived hydrogelators by systematically varying the electron-donating or electron-withdrawing nature of the side chain benzyl substituents and correlating these effects to the emergent assembly and gelation properties of the systems. These studies indicate a significant role for stabilizing dipolar interactions between neighboring benzyl groups in the assembled materials. Additional evidence for specific dipolar interactions is provided by high-resolution crystal structures obtained from dynamic transition of gel fibrils to crystals for several of the self-assembled/coassembled Fmoc-Phe derivatives. In addition to electronic effects, steric properties also have a significant effect on the interaction between neighboring benzyl groups in these assembled systems. These findings provide significant insight into the structure-function relationship for Fmoc-Phe-derived hydrogelators and give cues for the design of next-generation materials with desired emergent properties.

Improved synthesis and application of [(11) C]benzyl iodide in positron emission tomography radiotracer production.

PubMed

Pekošak, Aleksandra; Filp, Ulrike; Rotteveel, Lonneke; Poot, Alex J; Windhorst, Albert D

2015-06-30

Positron emission tomography has increased the demand for new carbon-11 radiolabeled tracers and building blocks. A promising radiolabeling synthon is [(11) C]benzyl iodide ([(11) C]BnI), because the benzyl group is a widely present functionality in biologically active compounds. Unfortunately, synthesis of [(11) C]BnI has received little attention, resulting in limited application. Therefore, we investigated the synthesis in order to significantly improve, automate, and apply it for labeling of the dopamine D2 antagonist [(11) C]clebopride as a proof of concept. [(11) C]BnI was synthesized from [(11) C]CO2 via a Grignard reaction and purified prior the reaction with desbenzyl clebopride. According to a one-pot procedure, [(11) C]BnI was synthesized in 11 min from [(11) C]CO2 with high yield, purity, and specific activity, 52 ± 3% (end of the cyclotron bombardment), 95 ± 3%, and 123 ± 17 GBq/µmol (end of the synthesis), respectively. Changes in the [(11) C]BnI synthesis are reduced amounts of reagents, a lower temperature in the Grignard reaction, and the introduction of a solid-phase intermediate purification. [(11) C]Clebopride was synthesized within 28 min from [(11) C]CO2 in an isolated decay-corrected yield of 11 ± 3% (end of the cyclotron bombardment) with a purity of >98% and specific activity (SA) of 54 ± 4 GBq/µmol (n = 3) at the end of the synthesis. Conversion of [(11) C]BnI to product was 82 ± 11%. The reliable synthesis of [(11) C]BnI allows the broad application of this synthon in positron emission tomography radiopharmaceutical development. Copyright © 2015 John Wiley & Sons, Ltd.

Isocyanides inhibit human heme oxygenases at the verdoheme stage.

PubMed

Evans, John P; Kandel, Sylvie; Ortiz de Montellano, Paul R

2009-09-22

Heme oxygenases (HO) catalyze the oxidative cleavage of heme to generate biliverdin, CO, and free iron. In humans, heme oxygenase-1 (hHO-1) is overexpressed in tumor tissues, where it helps to protect cancer cells from anticancer agents, while HOs in fungal pathogens, such as Candida albicans, function as the primary means of iron acquisition. Thus, HO can be considered a potential therapeutic target for certain diseases. In this study, we have examined the equilibrium binding of three isocyanides, isopropyl, n-butyl, and benzyl, to the two major human HO isoforms (hHO-1 and hHO-2), Candida albicans HO (CaHmx1), and human cytochrome P450 CYP3A4 using electronic absorption spectroscopy. Isocyanides coordinate to both ferric and ferrous HO-bound heme, with tighter binding by the more hydrophobic isocyanides and 200-300-fold tighter binding to the ferrous form. Benzyl isocyanide was the strongest ligand to ferrous heme in all the enzymes. Because the dissociation constants (KD) of the ligands for ferrous heme-hHO-1 were below the limit of accuracy for equilibrium titrations, stopped-flow kinetic experiments were used to measure the binding parameters of the isocyanides to ferrous hHO-1. Steady-state activity assays showed that benzyl isocyanide was the most potent uncompetitive inhibitor with respect to heme with a KI = 0.15 microM for hHO-1. Importantly, single turnover assays revealed that the reaction was completely stopped by coordination of the isocyanide to the verdoheme intermediate rather than to the ferric heme complex. Much tighter binding of the inhibitor to the verdoheme intermediate differentiates it from inhibition of, for example, CYP3A4 and offers a possible route to more selective inhibitor design.

Isocyanides Inhibit Human Heme Oxygenases at the Verdoheme Stage†

PubMed Central

Evans, John P.; Kandel, Sylvie; Ortiz de Montellano, Paul R.

2010-01-01

Heme oxygenases (HO) catalyze the oxidative cleavage of heme to generate biliverdin, CO, and free iron. In humans, heme oxygenase-1 (hHO-1) is overexpressed in tumor tissues, where it helps to protect cancer cells from anticancer agents, while HOs in fungal pathogens, such as Candida albicans, function as the primary means of iron acquisition. Thus, HO can be considered a potential therapeutic target for certain diseases. In this study, we have examined the equilibrium binding of three isocyanides; isopropyl, n-butyl, and benzyl, to the two major human HO isoforms (hHO-1 and hHO-2), Candida albicans HO (CaHmx1), and human cytochrome P450 CYP3A4 using electronic absorption spectroscopy. Isocyanides coordinate to both ferric and ferrous HO-bound heme, with tighter binding by the more hydrophobic isocyanides, and 200-300-fold tighter binding to the ferrous form. Benzyl isocyanide was the strongest ligand to ferrous heme in all the enzymes. Because the dissociation constants (KD) of the ligands for ferrous heme-hHO-1 were below the limit of accuracy for equilibrium titrations, stopped-flow kinetic experiments were used to measure the binding parameters of the isocyanides to ferrous hHO-1. Steady-state activity assays showed that benzyl isocyanide was the most potent uncompetitive inhibitor with respect to heme with a KI = 0.15 μM for hHO-1. Importantly, single turnover assays revealed that the reaction was completely stopped by coordination of the isocyanide to the verdoheme intermediate rather than to the ferric heme complex. Much tighter binding of the inhibitor to the verdoheme intermediate differentiates it from inhibition of, for example, CYP3A4 and offers a possible route to more selective inhibitor design. PMID:19694439

Differential Degradation of Nonylphenol Isomers by Sphingomonas xenophaga Bayram

PubMed Central

Gabriel, Frédéric L. P.; Giger, Walter; Guenther, Klaus; Kohler, Hans-Peter E.

2005-01-01

Sphingomonas xenophaga Bayram, isolated from the activated sludge of a municipal wastewater treatment plant, was able to utilize 4-(1-ethyl-1,4-dimethylpentyl)phenol, one of the main isomers of technical nonylphenol mixtures, as a sole carbon and energy source. The isolate degraded 1 mg of 4-(1-ethyl-1,4-dimethylpentyl)phenol/ml in minimal medium within 1 week. Growth experiments with five nonylphenol isomers showed that the three isomers with quaternary benzylic carbon atoms [(1,1,2,4-tetramethylpentyl)phenol, 4-(1-ethyl-1,4-dimethylpentyl)phenol, and 4-(1,1-dimethylheptyl)phenol] served as growth substrates, whereas the isomers containing one or two hydrogen atoms in the benzylic position [4-(1-methyloctyl)phenol and 4-n-nonylphenol] did not. However, when the isomers were incubated as a mixture, all were degraded to a certain degree. Differential degradation was clearly evident, as isomers with more highly branched alkyl side chains were degraded much faster than the others. Furthermore, the C9 alcohols 2,3,5-trimethylhexan-2-ol, 3,6-dimethylheptan-3-ol, and 2-methyloctan-2-ol, derived from the three nonylphenol isomers with quaternary benzylic carbon atoms, were detected in the culture fluid by gas chromatography-mass spectrometry, but no analogous metabolites could be found originating from 4-(1-methyloctyl)phenol and 4-n-nonylphenol. We propose that 4-(1-methyloctyl)phenol and 4-n-nonylphenol were cometabolically transformed in the growth experiments with the mixture but that, unlike the other isomers, they did not participate in the reactions leading to the detachment of the alkyl moiety. This hypothesis was corroborated by the observed accumulation in the culture fluid of an as yet unidentified metabolite derived from 4-(1-methyloctyl)phenol. PMID:15746308

Structure-property relationship of 3-(4-substituted benzyl)-1,3-diazaspiro[4.4]nonane-2,4-diones as new potentional anticonvulsant agents. An experimental and theoretical study

NASA Astrophysics Data System (ADS)

Lazić, Anita M.; Božić, Bojan Đ.; Vitnik, Vesna D.; Vitnik, Željko J.; Rogan, Jelena R.; Radovanović, Lidija D.; Valentić, Nataša V.; Ušćumlić, Gordana S.

2017-01-01

The structure-property relationship of newly synthesized 3-(4-substituted benzyl)-1,3-diazaspiro [4.4]nonane-2,4-diones was studied by experimental and calculated methods. The prepared compounds were characterized by UV-Vis, FT-IR, 1H NMR and 13C NMR spectroscopy and elemental analysis. The crystal structure was elucidated by single-crystal X-ray diffraction. The 3-benzyl-1,3-diazaspiro[4.4]nonane-2,4-dione crystallizes in triclinic P-1 space group, with two crystallographically independent molecules in the asymmetric unit. Cyclopentane ring adopts an envelope conformation. A three-dimensional crystal packing is governed by hydrogen N-H⋯O bonds, numerous C-H⋯O/N and C-H … π interactions between neighboring molecules. Density functional theory (DFT) calculations with B3LYP and M06-2X methods using 6-311++G(d,p) basis set were performed to provide structural and spectroscopic information. Comparisons between experimental and calculated UV-Vis spectral properties suggest that the monomeric form of the investigated spirohydantoins is dominant in all used solvents. The effects of substituents on the absorption spectra of spirohydantoins are interpreted by correlation of absorption frequencies with Hammett equation. The lipophilicities of the investigated molecules were estimated by calculation of their log P values. Some of the spirohydantoins synthesized in this work, exhibit the lipophilicities comparable to the standard medicine anticonvulsant drug Phenytoin. The results obtained in this investigation afford guidelines for the preparation of new derivatives of spirohydantoin as potential anticonvulsant agents and for better understanding the structure-activity relationship.

Antiadhesive Character of Mucin O-glycans at the Apical Surface of Corneal Epithelial Cells

PubMed Central

Sumiyoshi, Mika; Ricciuto, Jessica; Tisdale, Ann; Gipson, Ilene K.; Mantelli, Flavio; Argüeso, Pablo

2008-01-01

Purpose Prolonged contact of opposite mucosal surfaces, which occurs on the ocular surface, oral cavity, reproductive tract, and gut, requires a specialized apical cell surface that prevents adhesion. The purpose of this study was to evaluate the contribution of mucin O-glycans to the antiadhesive character of human corneal–limbal epithelial (HCLE) cells. Methods Mucin O-glycan biosynthesis in HCLE cells was disrupted by metabolic interference with benzyl-α-GalNAc. The cell surface mucin MUC16 and its carbohydrate epitope H185 were detected by immunofluorescence and Western blot. HCLE cell surface features were assessed by field emission scanning electron microscopy. Cell–cell adhesion assays were performed under static conditions and in a parallel plate laminar flow chamber. Results Benzyl-α-GalNAc disrupted the biosynthesis of O-glycans without affecting apomucin biosynthesis or cell surface morphology. Static adhesion assays showed that the apical surface of differentiated HCLE cells expressing MUC16 and H185 was more antiadhesive than undifferentiated HCLE cells, which lacked MUC16. Abrogation of mucin O-glycosylation in differentiated cultures with benzyl-α-GalNAc resulted in increased adhesion of applied corneal epithelial cells and corneal fibroblasts. The antiadhesive effect of mucin O-glycans was further demonstrated by fluorescence video microscopy in dynamic flow adhesion assays. Cationized ferritin labeling of the cell surface indicated that anionic repulsion did not contribute to the antiadhesive character of the apical surface. Conclusions These results indicate that epithelial O-glycans contribute to the antiadhesive properties of cell surface–associated mucins in corneal epithelial cells and suggest that alterations in mucin O-glycosylation are involved in the pathology of drying mucosal diseases (e.g., dry eye). PMID:18172093