BENZYL ALCOHOL PROTECTS AGAINST ACETAMINOPHEN HEPATOTOXICITY BY INHIBITING CYTOCHROME P450 ENZYMES BUT CAUSES MITOCHONDRIAL DYSFUNCTION AND CELL DEATH AT HIGHER DOSES

PubMed Central

Du, Kuo; McGill, Mitchell R.; Xie, Yuchao; Jaeschke, Hartmut

2015-01-01

Acetaminophen (APAP) hepatotoxicity is a serious public health problem in western countries. Current treatment options for APAP poisoning are limited and novel therapeutic intervention strategies are needed. A recent publication suggested that benzyl alcohol (BA) protects against APAP hepatotoxicity and could serve as a promising antidote for APAP poisoning. To assess the protective mechanisms of BA, C56Bl/6J mice were treated with 400mg/kg APAP and/or 270mg/kg BA. APAP alone caused extensive liver injury at 6h and 24h post-APAP. This injury was attenuated by BA co-treatment. Assessment of protein adduct formation demonstrated that BA inhibits APAP metabolic activation. In support of this, in vitro experiments also showed that BA dose-dependently inhibits cytochrome P450 activities. Correlating with the hepatoprotection of BA, APAP-induced oxidant stress and mitochondrial dysfunction were reduced. Similar results were obtained in primary mouse hepatocytes. Interestingly, BA alone caused mitochondrial membrane potential loss and cell toxicity at high doses, and its protective effect could not be reproduced in primary human hepatocytes (PHH). We conclude that BA protects against APAP hepatotoxicity mainly by inhibiting cytochrome P450 enzymes in mice. Considering its toxic effect and the loss of protection in PHH, BA is not a clinically useful treatment option for APAP overdose patient. PMID:26522885

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.

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...

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.

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

21 CFR 522.161 - Betamethasone acetate and betamethasone disodium phosphate aqueous suspension.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Betamethasone acetate and betamethasone disodium phosphate aqueous suspension. 522.161 Section 522.161 Food and Drugs FOOD AND DRUG ADMINISTRATION... milligram of polysorbate 80, 9 milligrams of benzyl alcohol, 5 milligrams of sodium carboxymethylcellulose...

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)

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.

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.

Improvement of the butanol production selectivity and butanol to acetone ratio (B:A) by addition of electron carriers in the batch culture of a new local isolate of Clostridium acetobutylicum YM1.

PubMed

Nasser Al-Shorgani, Najeeb Kaid; Kalil, Mohd Sahaid; Wan Yusoff, Wan Mohtar; Shukor, Hafiza; Hamid, Aidil Abdul

2015-12-01

Improvement in the butanol production selectivity or enhanced butanol:acetone ratio (B:A) is desirable in acetone-butanol-ethanol (ABE) fermentation by Clostridium strains. In this study, artificial electron carriers were added to the fermentation medium of a new isolate of Clostridium acetobutylicum YM1 in order to improve the butanol yield and B:A ratio. The results revealed that medium supplementation with electron carriers changed the metabolism flux of electron and carbon in ABE fermentation by YM1. A decrease in acetone production, which subsequently improved the B:A ratio, was observed. Further improvement in the butanol production and B:A ratios were obtained when the fermentation medium was supplemented with butyric acid. The maximum butanol production (18.20 ± 1.38 g/L) was gained when a combination of methyl red and butyric acid was added. Although the addition of benzyl viologen (0.1 mM) and butyric acid resulted in high a B:A ratio of 16:1 (800% increment compared with the conventional 2:1 ratio), the addition of benzyl viologen to the culture after 4 h resulted in the production of 18.05 g/L butanol. Manipulating the metabolic flux to butanol through the addition of electron carriers could become an alternative strategy to achieve higher butanol productivity and improve the B:A ratio. Copyright © 2015 Elsevier Ltd. All rights reserved.

Methane Upgrading of Acetic Acid as a Model Compound for a Biomass-Derived Liquid over a Modified Zeolite Catalyst

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

Wang, Aiguo; Austin, Danielle; Karmakar, Abhoy

The technical feasibility of coaromatization of acetic acid derived from biomass and methane was investigated under mild reaction conditions (400 °C and 30 bar) over silver-, zinc-, and/or gallium-modified zeolite catalysts. On the basis of GC-MS, Micro-GC, and TGA analysis, more light aromatic hydrocarbons, less phenol formation, lower coke production, and higher methane conversion are observed over 5%Zn-1%Ga/ZSM-5 catalyst in comparison with catalytic performance over the other catalysts. Direct evidence of methane incorporation into aromatics over 5%Zn-1%Ga/ZSM-5 catalyst is witnessed in 1H, 2H, and 13C NMR spectra, revealing that the carbon from methane prefers to occupy the phenyl carbon sitesmore » and the benzylic carbon sites, and the hydrogen of methane favors the aromatic and benzylic substitutions of product molecules. In combination with the 13C NMR results for isotopically labeled acetic acid ( 13CH 3COOH and CH 3 13COOH), it can be seen that the methyl and carbonyl carbons of acetic acid are equally involved in the formation of ortho, meta and para carbons of the aromatics, whereas the phenyl carbons directly bonded with alkyl substituent groups and benzylic carbons are derived mainly from the carboxyl carbon of acetic acid. After various catalyst characterizations by using TEM, XRD, DRIFT, NH 3-TPD, and XPS, the excellent catalytic performance might be closely related to the highly dispersed zinc and gallium species on the zeolite support, moderate surface acidity, and an appropriate ratio of weak acidic sites to strong acidic sites as well as the fairly stable oxidation state during acetic acid conversion under a methane environment. Two mechanisms of the coaromatization of acetic acid and methane have also been proposed after consulting all the collected data in this study. In conclusion, the results reported in this paper could potentially lead to more cost-effective utilization of abundant natural gas and biomass.« less

Methane Upgrading of Acetic Acid as a Model Compound for a Biomass-Derived Liquid over a Modified Zeolite Catalyst

DOE PAGES

Wang, Aiguo; Austin, Danielle; Karmakar, Abhoy; ...

2017-04-19

The technical feasibility of coaromatization of acetic acid derived from biomass and methane was investigated under mild reaction conditions (400 °C and 30 bar) over silver-, zinc-, and/or gallium-modified zeolite catalysts. On the basis of GC-MS, Micro-GC, and TGA analysis, more light aromatic hydrocarbons, less phenol formation, lower coke production, and higher methane conversion are observed over 5%Zn-1%Ga/ZSM-5 catalyst in comparison with catalytic performance over the other catalysts. Direct evidence of methane incorporation into aromatics over 5%Zn-1%Ga/ZSM-5 catalyst is witnessed in 1H, 2H, and 13C NMR spectra, revealing that the carbon from methane prefers to occupy the phenyl carbon sitesmore » and the benzylic carbon sites, and the hydrogen of methane favors the aromatic and benzylic substitutions of product molecules. In combination with the 13C NMR results for isotopically labeled acetic acid ( 13CH 3COOH and CH 3 13COOH), it can be seen that the methyl and carbonyl carbons of acetic acid are equally involved in the formation of ortho, meta and para carbons of the aromatics, whereas the phenyl carbons directly bonded with alkyl substituent groups and benzylic carbons are derived mainly from the carboxyl carbon of acetic acid. After various catalyst characterizations by using TEM, XRD, DRIFT, NH 3-TPD, and XPS, the excellent catalytic performance might be closely related to the highly dispersed zinc and gallium species on the zeolite support, moderate surface acidity, and an appropriate ratio of weak acidic sites to strong acidic sites as well as the fairly stable oxidation state during acetic acid conversion under a methane environment. Two mechanisms of the coaromatization of acetic acid and methane have also been proposed after consulting all the collected data in this study. In conclusion, the results reported in this paper could potentially lead to more cost-effective utilization of abundant natural gas and biomass.« less

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...

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.

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.

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.

Palladium-catalyzed substitution of (coumarinyl)methyl acetates with C-, N-, and S-nucleophiles

PubMed Central

Chattopadhyay, Kalicharan; Fenster, Erik; Grenning, Alexander J

2012-01-01

Summary The palladium-catalyzed nucleophilic substitution of (coumarinyl)methyl acetates is described. The reaction proceeds though a palladium π-benzyl-like complex and allows for many different types of C-, N-, and S-nucleophiles to be regioselectively added to the biologically active coumarin motif. This new method was utilized to prepare a 128-membered library of aminated coumarins for biological screening. PMID:23019448

Benzyl alcohol increases voluntary ethanol drinking in rats.

PubMed

Etelälahti, T J; Eriksson, C J P

2014-09-01

The anabolic steroid nandrolone decanoate has been reported to increase voluntary ethanol intake in Wistar rats. In recent experiments we received opposite results, with decreased voluntary ethanol intake in both high drinking AA and low drinking Wistar rats after nandrolone treatment. The difference between the two studies was that we used pure nandrolone decanoate in oil, whereas in the previous study the nandrolone product Deca-Durabolin containing benzyl alcohol (BA) was used. The aims of the present study were to clarify whether the BA treatment could promote ethanol drinking and to assess the role of the hypothalamic-pituitary-adrenal-gonadal axes (HPAGA) in the potential BA effect. Male AA and Wistar rats received subcutaneously BA or vehicle oil for 14 days. Hereafter followed a 1-week washout and consecutively a 3-week voluntary alcohol consumption period. The median (± median absolute deviation) voluntary ethanol consumption during the drinking period was higher in BA-treated than in control rats (4.94 ± 1.31 g/kg/day vs. 4.17 ± 0.31 g/kg/day, p = 0.07 and 1.01 ± 0.26 g/kg/day vs. 0.38 ± 0.27 g/kg/day, p = 0.05, for AA and Wistar rats, respectively; combined effect p < 0.01). The present results can explain the previous discrepancy between the two nandrolone studies. No significant BA effects on basal and ethanol-mediated serum testosterone and corticosterone levels were observed in blood samples taken at days 1, 8 and 22. However, 2h after ethanol administration significantly (p = 0.02) higher frequency of testosterone elevations was detected in high drinking AA rats compared to low drinking Wistars, which supports our previous hypotheses of a role of testosterone elevation in promoting ethanol drinking. Skin irritation and dermatitis were shown exclusively in the BA-treated animals. Altogether, the present results indicate that earlier findings obtained with Deca-Durabolin containing BA need to be re-evaluated. Copyright © 2014 Elsevier Inc. All rights reserved.

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.

4-Nitro­benzyl 2-bromo­acetate

PubMed Central

Zhu, Kai; Liu, Hui; Wang, Yan-Hua; Han, Ping-Fang; Wei, Ping

2009-01-01

In the mol­ecule of the title compound, C9H8BrNO4, the acetate group is close to planar [maximum deviation = 0.042 (3) Å] and is oriented at a dihedral angle of 73.24 (3)° with respect to the aromatic ring. In the crystal structure, inter­molecular C—H⋯O inter­actions link the mol­ecules into a three-dimensional network, forming R 2 2(10) ring motifs. PMID:21582813

Design and synthesis of alkoxyindolyl-3-acetic acid analogs as peroxisome proliferator-activated receptor-γ/δ agonists.

PubMed

Gim, Hyo Jin; Li, Hua; Lee, Eun; Ryu, Jae-Ha; Jeon, Raok

2013-01-15

A series of carbazole or phenoxazine containing alkoxyindole-3-acetic acid analogs were prepared as PPARγ/δ agonists and their transactivation activities for PPAR receptor subtypes (α, γ and δ) were investigated. Structure-activity relationship studies disclosed the effect of the lipophilic tail, attaching position of the alkoxy group and N-benzyl substitution at indole. Compound 1b was the most potent for PPARδ and 3b for PPARγ. Molecular modeling suggested two different binding modes of our alkoxyindole-3-acetic acid analogs providing the insight into their PPAR activity. Copyright © 2012 Elsevier Ltd. All rights reserved.

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.

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

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.

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.

21 CFR 522.161 - Betamethasone acetate and betamethasone disodium phosphate aqueous suspension.

Code of Federal Regulations, 2013 CFR

2013-04-01

... milligrams of dibasic sodium phosphate, 5 milligrams of sodium chloride, 0.1 milligram of disodium EDTA, 0.5 milligram of polysorbate 80, 9 milligrams of benzyl alcohol, 5 milligrams of sodium carboxymethylcellulose, 1.8 milligrams of methylparaben, 0.2 milligram of propylparaben, hydrochloric acid and/or sodium...

21 CFR 522.161 - Betamethasone acetate and betamethasone disodium phosphate aqueous suspension.

Code of Federal Regulations, 2011 CFR

2011-04-01

... milligrams of dibasic sodium phosphate, 5 milligrams of sodium chloride, 0.1 milligram of disodium EDTA, 0.5 milligram of polysorbate 80, 9 milligrams of benzyl alcohol, 5 milligrams of sodium carboxymethylcellulose, 1.8 milligrams of methylparaben, 0.2 milligram of propylparaben, hydrochloric acid and/or sodium...

21 CFR 522.161 - Betamethasone acetate and betamethasone disodium phosphate aqueous suspension.

Code of Federal Regulations, 2012 CFR

2012-04-01

... milligrams of dibasic sodium phosphate, 5 milligrams of sodium chloride, 0.1 milligram of disodium EDTA, 0.5 milligram of polysorbate 80, 9 milligrams of benzyl alcohol, 5 milligrams of sodium carboxymethylcellulose, 1.8 milligrams of methylparaben, 0.2 milligram of propylparaben, hydrochloric acid and/or sodium...

Improving trapping systems for early detection and eradication of fruit flies (Diptera: Tephritidae) in California

USDA-ARS?s Scientific Manuscript database

Solid Mallet TMR (trimedlure [TML], methyl eugenol [ME], raspberry ketone [RK]) wafers and Mallet CMR (ceralure, ME, RK, benzyl acetate) wafers impregnated with DDVP insecticide were evaluated in traps as potential detection and male annihilation devices. Comparisons were made with 1) liquid lure an...

The study of ascorbate peroxidase, catalase and peroxidase during in vitro regeneration of Argyrolobium roseum.

PubMed

Habib, Darima; Chaudhary, Muhammad Fayyaz; Zia, Muhammad

2014-01-01

Here, we demonstrate the micropropagation protocol of Argyrolobium roseum (Camb.), an endangered herb exhibiting anti-diabetic and immune-suppressant properties, and antioxidant enzymes pattern is evaluated. Maximum callogenic response (60 %) was observed from leaf explant at 1.0 mg L(-1) 1-nephthalene acetic acid (NAA) and 0.5 mg L(-1) 6-benzyl aminopurine (BA) in Murashige and Skoog (MS) medium using hypocotyl and root explants (48 % each). Addition of AgNO3 and PVP in the culture medium led to an increase in callogenic response up to 86 % from leaf explant and 72 % from hypocotyl and root explants. The best shooting response was observed in the presence of NAA, while maximum shoot length and number of shoots were achieved based on BA-supplemented MS medium. The regenerated shoots were rooted and successfully acclimatized under greenhouse conditions. Catalase and peroxidase enzymes showed ascending pattern during in vitro plant development from seed while ascorbate peroxidase showed descending pattern. Totally reverse response of these enzymes was observed during callus induction from three different explants. During shoot induction, catalase and peroxidase increased at high rate while there was a mild reduction in ascorbate peroxidase activity. Catalase and peroxidase continuously increased; on the other hand, ascorbate peroxidase activity decreased during root development and acclimatization states. The protocol described here can be employed for the mass propagation and genetic transformation of this rare herb. This study also highlights the importance and role of ascorbate peroxidase, catalase, and peroxidase in the establishment of A. roseum in vitro culture through callogenesis and organogenesis.

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.

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.

Developing kairomone-based lures and traps targeting female Spilonota ocellana (Lepidoptera: Tortricidae) in apple orchards treated with ex pheromones

USDA-ARS?s Scientific Manuscript database

Spilonota ocellana (Denis and Schiffermüller) can be a serious pest of organic apples in British Columbia. Recent discovery that S. ocellana moths are attracted by a lure combining acetic acid (AA) and benzyl nitrile (BN), a caterpillar-induced apple leaf volatile, provides an opportunity to develo...

Correlation of Microwave Dielectric Properties and Microstructure of Unpatterned Ferroelectric Thin Films

DTIC Science & Technology

2003-04-03

technique. Ba acetate, Sr acetate, and Ti isopropoxide were used as precursors to form BST. Acetic acid and 2-methoxyethanol were used as solvents and...resulting from the generation of oxygen vacancy can hop between different titanium ions and provide a mechanism for dielectric losses, 2+the

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.

In vitro propagation of female Ephedra foliata Boiss. & Kotschy ex Boiss.: an endemic and threatened Gymnosperm of the Thar Desert.

PubMed

Lodha, Deepika; Rathore, Nisha; Kataria, Vinod; Shekhawat, N S

2014-07-01

Ephedra foliata Boiss. & Kotschy ex Boiss., (family - Ephedraceae), is an ecologically and economically important threatened Gymnosperm of the Indian Thar Desert. A method for micropropagation of E. foliata using nodal explant of mature female plant has been developed. Maximum bud-break (90 %) of the explant was obtained on MS medium supplemented with 1.5 mg l(-1) of benzyl adenine (BA) + additives. Explant produces 5.3 ± 0.40 shoots from single node with 3.25 ± 0.29 cm length. The multiplication of shoots in culture was affected by salt composition of media, types and concentrations of plant growth regulators (PGR's) and their interactions, time of transfer of the cultures. Maximum number of shoots (26.3 ± 0.82 per culture vessel) were regenerated on MS medium modified by reducing the concentration of nitrates to half supplemented with 200 mg l(-1) ammonium sulphate {(NH4) 2SO4} (MMS3) + BA (0.25 mg l(-1)), Kinetin (Kin; 0.25 mg l(-1)), Indole-3-acetic acid (IAA; 0.1 mg l(-1)) and additives. The in vitro produced shoots rooted under ex vitro on soilrite moistened with one-fourth strength of MS macro salts in screw cap bottles by treating the shoot base (s) with 500 mg l(-1) of Indole-3-butyric acid (IBA) for 5 min. The micropropagated plants were hardened in the green house. The described protocol can be applicable for (i) large scale plant production (ii) establishment of plants in natural habitat and (iii) germplasm conservation of this endemic Gymnosperm of arid regions.

Zeatin and Thidiazuron Induced Embryogenic Calli From In Vitro Leaf and Stem of Jojoba (Simmondsia chinensis).

PubMed

El-Ashry, Amal Abd El-Latif; Gabr, Ahmed Mohamed Magdy; Bekheet, Shawky Abd El-Hamid

2017-01-01

Jojoba is a promising industrial plant, which recommended with pharmaceutical benefits. The present study was conducted to stimulate embryogenic calli formation from jojoba using zeatin and thidiazuron (TDZ), as well as determination of the antioxidant activity of proliferated calli. For callus induction, leaf and stem explants derived from in vitro grown shootlets, were cultured on Murashige and Skoog (MS) medium with different combinations of 0.5 mg L-1 benzyl adenine (BA) or kinetin with 2,4-Dichlorophenoxyacetic acid (2,4-D), Naphthalene acetic acid (NAA) and picloram at 0.5 or 1mg L-1. To stimulate embryogenic calli, friable callus were transferred to woody plant medium (WPM) supplemented with different concentrations of zeatin or TDZ. Antioxidant activity of different treatments was determined using hexane or petroleum ether extraction. Data was analyzed as mean±standard deviation (SD). The MS medium supplemented with 0.5 mg L-1 BA+0.5 or 1 mg L-1 picloram was the best treatment to obtain friable calli from both explants types. WPM medium supplemented with 2 mg L-1 zeatin gave the highest percentage of embryogenic calli derived from leaf explants. While the highest percentage of embryogenic calli derived from stem explants was registered using 1 or 4 mg L-1 TDZ containing medium. Embryogenic calli originated from leaves explants on 1.5 mg L-1 zeatin showed promising activity of antioxidant with hexane extraction. However, embryogenic calli originated from stem explants on 1 mg L-1 TDZ showed the highest antioxidant activity with petroleum ether extraction. TDZ has promising effect on embryogenic callus induction from stem explants. While, zeatin has promising effect on embryogenic callus induction from leaf explants.

Improvement of Aconitum napellus micropropagation by liquid culture on floating membrane rafts.

PubMed

Watad, A A; Kochba, M; Nissim, A; Gaba, V

1995-03-01

An efficient method was developed using floating membrane rafts (Liferaft(™)) for the micropropagation of Aconitum napellus (Ranunculaceae), a cut flower crop with a low natural propagation rate. This was achieved by introducing shoot tips into culture on Murashige and Skoog's (1962) solid medium, or liquid medium-supported rafts, supplemented by different levels of benzyl adenine (BA). Optimum shoot proliferation on solid medium required 4mg/l BA, whereas for expiants supported on rafts optimal proliferation was achieved at 0.25mg/l BA. Maximum shoot proliferation was found using the floating rafts (propagation ratio of 4.2 per month), 45% higher than the maximum value on solid medium. A similar value could be obtained on solid medium after a period of 2 months. The optimal response to BA was similar for fresh weight gain and shoot length. Growth in a shallow layer of liquid in shake flasks gives a similar shoot multiplication rate to that on floating rafts; however, submerged leaves brown and die.

Volatile constituents of Trichothecium roseum.

PubMed

Vanhaelen, M; Vanhaelen-Fastre, R; Geeraerts, J

1978-06-01

In the course of investigation of Trichothecium roseum (Fungi Imperfecti) for its attractancy against Tyrophagus putrescentiae (cheese mite), the twenty following volatile compounds produced at a very low concentration by the microfungus were identified by gc, gc/ms, gc/c.i.ms and tlc: 3-methyl-1-butanol, 3-octanone, 1-octen-3-one, 3-octanol, octa-1,5-dien-3 one, 1-octen-3-ol, 6-methyl-5-hepten-2-ol, octa-1,5-dien-3 ol, furfural, linalool, linalyl acetate, terpineol (alpha and beta) citronellyl acetate, nerol, citronellol, phenylacetaldehyde, benzyl alcohol geranyl acetate, 1-phenyl ethanol and nerolidol. Octa-1,5-dien-3-ol and octa-1,5-dien-3-one have not been previously isolated from fungi; octa-1,5-dien-3-ol is the most potent attractant amount the volatile compounds detected by gc.

Analysis of residual products in triethylbenzylammonium chloride by HPLC. Study of the retention mechanism.

PubMed

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

2006-04-01

The control of industrial products for minimization of their impact on the environment and human health requires the development of specific analysis methods. Information provided by these methods about toxic components, by-products, and other derivatives may also be useful to reduce the possible impact of industrial products. The studied compound in this paper, triethylbenzylammonium chloride (TEBA), is mainly used in industrial synthesis. This quaternary compound and its residual products coming from quaternization reaction (benzyl chloride, benzaldehyde, and benzyl alcohol) are analyzed by HPLC. The separation is based on control of the silanophilic contribution to TEBA retention because of the quaternary nature of this compound. The effect of the three buffers (sodium acetate, ammonium acetate, and sodium formate) and their concentrations in the chromatographic behavior of the quaternary compound is examined. The buffer cation and anion regulate TEBA retention. Also, the concentration of the quaternary compound is another parameter that had influence in some aspects of its chromatographic behavior (e.g., retention and symmetry). The proposed method is applied to TEBA synthesis along, with the formation and removal of impurities with the results compared with those obtained for the quaternary compound benzalkonium chloride.

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.

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

Field trials of solid triple lure (trimedlure, methyl eugenol, raspberry ketone, and DDVP) dispensers for detection and male annihilation of Ceratitis capitata (Wiedemann), Bactrocera dorsalis (Hendel) and Bactrocera cucurbit

USDA-ARS?s Scientific Manuscript database

Solid Mallet TMR (trimedlure [TML], methyl eugenol [ME], raspberry ketone [RK]) wafers and Mallet CMR (ceralure, ME, RK, benzyl acetate) wafers impregnated with DDVP insecticide were evaluated in traps as potential detection and male annihilation devices. Comparisons were made with 1) liquid lure a...

Crystal structure of a mixed-ligand dinuclear Ba-Zn complex with 2-meth-oxy-ethanol having tri-phenyl-acetate and chloride bridges.

PubMed

Utko, Józef; Sobocińska, Maria; Dobrzyńska, Danuta; Lis, Tadeusz

2015-07-01

The dinuclear barium-zinc complex, μ-chlorido-1:2κ(2) Cl:Cl-chlorido-2κCl-bis-(2-meth-oxy-ethanol-1κO)bis-(2-meth-oxy-ethanol-1κ(2) O,O')bis-(μ-tri-phenyl-acetato-1:2κ(2) O:O')bariumzinc, [BaZn(C20H15O2)2Cl2(C3H8O2)4], has been synthesized by the reaction of barium tri-phenyl-acetate, anhydrous zinc chloride and 2-meth-oxy-ethanol in the presence of toluene. The barium and zinc metal cations in the dinuclear complex are linked via one chloride anion and carboxyl-ate O atoms of the tri-phenyl-acetate ligands, giving a Ba⋯Zn separation of 3.9335 (11) Å. The irregular nine-coordinate BaO8Cl coordination centres comprise eight O-atom donors, six of them from 2-meth-oxy-ethanol ligands (four from two bidentate O,O'-chelate inter-actions and two from monodentate inter-actions), two from bridging tri-phenyl-acetate ligands and one from a bridging Cl donor. The distorted tetra-hedral coordination sphere of zinc comprises two O-atom donors from the tri-phenyl-acetate ligands and two Cl donors (one bridging and one terminal). In the crystal, O-H⋯Cl, O-H⋯O and C-H⋯Cl inter-molecular inter-actions form a layered structure, lying parallel to (001).

Formation and characterization of a reactive chromium(v)–oxo complex: mechanistic insight into hydrogen-atom transfer reactions† †Electronic supplementary information (ESI) available: Crystallographic data of 2 and 3 in CIF, ESI-TOF-MS, UV-vis, ESR, DFT calculations, 1H NMR, and GC-MS data. CCDC 1017025 and 1017026. See DOI: 10.1039/c4sc02285h Click here for additional data file.

PubMed Central

Kaida, Suzue; Ishizuka, Tomoya; Sakaguchi, Miyuki; Ogura, Takashi; Shiota, Yoshihito; Yoshizawa, Kazunari

2015-01-01

A mononuclear Cr(v)–oxo complex, [CrV(O)(6-COO–-tpa)](BF4)2 (1; 6-COO–-tpa = N,N-bis(2-pyridylmethyl)-N-(6-carboxylato-2-pyridylmethyl)amine) was prepared through the reaction of a Cr(iii) precursor complex with iodosylbenzene as an oxidant. Characterization of 1 was achieved using ESI-MS spectrometry, electron paramagnetic resonance, UV-vis, and resonance Raman spectroscopies. The reduction potential (E red) of 1 was determined to be 1.23 V vs. SCE in acetonitrile based on analysis of the electron-transfer (ET) equilibrium between 1 and a one-electron donor, [RuII(bpy)3]2+ (bpy = 2,2′-bipyridine). The reorganization energy (λ) of 1 was also determined to be 1.03 eV in ET reactions from phenol derivatives to 1 on the basis of the Marcus theory of ET. The smaller λ value in comparison with that of an Fe(iv)–oxo complex (2.37 eV) is caused by the small structural change during ET due to the dπ character of the electron-accepting LUMO of 1. When benzyl alcohol derivatives (R-BA) with different oxidation potentials were employed as substrates, corresponding aldehydes were obtained as the 2e–-oxidized products in moderate yields as determined from 1H NMR and GC-MS measurements. One-step UV-vis spectral changes were observed in the course of the oxidation reactions of BA derivatives by 1 and a kinetic isotope effect (KIE) was observed in the oxidation reactions for deuterated BA derivatives at the benzylic position as substrates. These results indicate that the rate-limiting step is a concerted proton-coupled electron transfer (PCET) from substrate to 1. In sharp contrast, in the oxidation of trimethoxy-BA (E ox = 1.22 V) by 1, trimethoxy-BA radical cation was observed by UV-vis spectroscopy. Thus, it was revealed that the mechanism of the oxidation reaction changed from one-step PCET to stepwise ET–proton transfer (ET/PT), depending on the redox potentials of R-BA. PMID:29560181

Volatile constituents of commercial imported and domestic black-ripe table olives (Olea europaea).

PubMed

Sansone-Land, Angelina; Takeoka, Gary R; Shoemaker, Charles F

2014-04-15

Volatile constituents of commercial black-ripe table olives (Olea europaea) from the United States, Spain, Egypt and Morocco were analysed by gas chromatography and gas chromatography-mass spectrometry (GC-MS). Dynamic headspace sampling was used to isolate a variety of aldehydes, alcohols, esters, ketones, phenols, terpenes, norisoprenoids, and pyridines. Odour unit values, calculated from concentration and odour threshold data, indicate that the following compounds are major contributors to black-ripe table olive aroma: β-damascenone, nonanal, (E)-dec-2-enal, 3-methylbutanal, ethyl benzoate, octanal, 2-methoxyphenol, 2-methylbutanal and 2-methoxy-4-methylphenol. Imported olives contained a variety of fermentation derived volatiles that were not detected in domestic olives. Constituents such as ethyl 2-methylbutanoate, ethyl 3-methylbutanoate, 3-methylbutyl acetate, oct-1-en-3-one, ethyl hexanoate, (Z)-hex-3-enyl acetate, hexyl acetate, ethyl cyclohexanecarboxylate, benzyl acetate and 4-ethylphenol contributed to the odour of imported olives but were not detected in domestic olives. Published by Elsevier Ltd.

Plant extracts affect in vitro rumen microbial fermentation.

PubMed

Busquet, M; Calsamiglia, S; Ferret, A; Kamel, C

2006-02-01

Different doses of 12 plant extracts and 6 secondary plant metabolites were incubated for 24 h in diluted ruminal fluid with a 50:50 forage:concentrate diet. Treatments were: control (no additive), plant extracts (anise oil, cade oil, capsicum oil, cinnamon oil, clove bud oil, dill oil, fenugreek, garlic oil, ginger oil, oregano oil, tea tree oil, and yucca), and secondary plant metabolites (anethol, benzyl salicylate, carvacrol, carvone, cinnamaldehyde, and eugenol). Each treatment was supplied at 3, 30, 300, and 3,000 mg/L of culture fluid. At 3,000 mg/L, most treatments decreased total volatile fatty acid concentration, but cade oil, capsicum oil, dill oil, fenugreek, ginger oil, and yucca had no effect. Different doses of anethol, anise oil, carvone, and tea tree oil decreased the proportion of acetate and propionate, which suggests that these compounds may not be nutritionally beneficial to dairy cattle. Garlic oil (300 and 3,000 mg/L) and benzyl salicylate (300 and 3,000 mg/L) reduced acetate and increased propionate and butyrate proportions, suggesting that methane production was inhibited. At 3,000 mg/L, capsicum oil, carvacrol, carvone, cinnamaldehyde, cinnamon oil, clove bud oil, eugenol, fenugreek, and oregano oil resulted in a 30 to 50% reduction in ammonia N concentration. Careful selection and combination of these extracts may allow the manipulation of rumen microbial fermentation.

Enzyme inhibitory metabolites from endophytic Penicillium citrinum isolated from Boswellia sacra.

PubMed

Ali, Sajid; Khan, Abdul Latif; Ali, Liaqat; Rizvi, Tania Shamim; Khan, Sumera Afzal; Hussain, Javid; Hamayun, Muhammad; Al-Harrasi, Ahmed

2017-07-01

Fungal endophytes establish an important niche within the host plant through the secretion of chemical constituents. Isolation of bioactive metabolites could be a vital source for inhibiting the function of enzymes such as α-glucosidase and urease. The present study aimed to elucidate the potential of endophytes associated with Boswellia sacra through bioassay-guided isolation and identification of secondary metabolites with enzyme inhibitory ability. Endophytic fungal strains viz. Penicillium citrinum, P. spinulosum, Fusarium oxysporum, Alternaria alternata and Aspergillus caespitosus were identified through genomic DNA extraction, PCR amplification, sequencing and phylogenetic analysis. The enzymes inhibition analysis of the ethyl acetate extract from pure cultures suggested that P. citrinum possess significantly higher enzyme inhibitory activities compared to other strains. The active strain was subjected to chromatographic isolation and nuclear magnetic resonance methods to identify bioactive compounds. The bioactive extracts resulted in the isolation of 11-oxoursonic acid benzyl ester (1), n-nonane (2), 3-decene-1-ol (3), 2-Hydroxyphenyl acetic acid (4), and Glochidacuminosides A (5). Among pure compound, 11-oxoursonic acid benzyl ester (1) showed significantly higher enzyme inhibition activity compared to other metabolites. Our results suggest that the endophytic microorganism associated with the arid-land tree can offer a rich source of biologically active chemical constituents that could help discover lead drugs for enzyme inhibition.

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'.

Eu-doped BaTiO₃powder and film from sol-gel process with polyvinylpyrrolidone additive.

PubMed

García-Hernández, Margarita; García-Murillo, Antonieta; de J Carrillo-Romo, Felipe; Jaramillo-Vigueras, David; Chadeyron, Geneviève; De la Rosa, Elder; Boyer, Damien

2009-09-17

Transparent BaTiO(3):Eu(3+) films were prepared via a sol-gel method and dip-coating technique, using barium acetate, titanium butoxide, and polyvinylpyrrolidone (PVP) as modifier viscosity. BaTiO(3):Eu(3+) films ~500 nm thick, crystallized after thermal treatment at 700 masculineC. The powders revealed spherical and rod shape morphology. The optical quality of films showed a predominant band at 615 nm under 250 nm excitation. A preliminary luminescent test provided the properties of the Eu(3+) doped BaTiO(3).

Effect of cytokinins and auxins on the growth of free-living conchocelis of Porphyra yezoensis

NASA Astrophysics Data System (ADS)

de-Lin, Duan; Xiu-Geng, Fei; Hong-Xu, Ren; Xiong, Chen; Ying, Zhu

1995-09-01

IAA 3-Indolylacetic acid, NAA a-Naphthylacetic acid and cytokinins in PESI culture medium were used in a study on the effects of plant hormones on the growth of free-living conchocelis of Porphyra yezoensis which showed that its growth in medium with cytokinins, IAA and NAA was more rapid than that in medium with non—phytohormones; that the optimal concentrations for promoting growth were 10 μg/L for IAA and ZA (Zeatin), and 0.1 μg/L for BA 6-Benzyl amino purine and KIN 6-Furfurylamino- purine. Mix use of NAA, IAA and cytokinins, NAA/ZA 1-1000/1 μg/L, NAA/BA 10/1-1000 μg/L, NAA/KIN 1/1-1000 μg/L promoted growth. IAA/ZA 0.1-1/0.1-1 μg/L; IAA/BA 0.1-1/0.1-10 μg/L IAA/KIN 1/0.1-1000 μg/L also promoted growth.

Structural Investigations of Fibers and Films of Poly(p-phenylene benzobisthiazole). Volume 1

DTIC Science & Technology

1982-05-01

differential scanning calorimetry, is unrelated to the diffuse scattered intensity [45]. Cellulose acetate which is known to be noncrystalline exhibits a high...Weidinger [45] found the diffuse scattered intensity increased with decreasing density and therefore, increasing void fraction, in air swollen cellulose ... Cellulose , and Poly(y-Benzyl-L-Glutamate)." J. Polym. Sci., Polym. Phys. Ed., 18, 663-682 (1980). 39. C.H. Kao and J.M. Ottino, personal communication

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.

Instability diagnosis and syntrophic acetate oxidation during thermophilic digestion of vegetable waste.

PubMed

Li, Dong; Ran, Yi; Chen, Lin; Cao, Qin; Li, Zhidong; Liu, Xiaofeng

2018-08-01

Effective process monitoring and instability diagnosis are important for stable anaerobic digestion (AD) of vegetable waste (VW). In order to evaluate the performance of thermophilic digestion of VW, to make early diagnosis for instability after organic overload, and to reveal the dynamics of microbial community under different running states, thermophilic AD of VW was carried out under improved organic loading rates (OLR) of 0.5-2.5 g volatile solid (VS)/(L ∙ d) in this study. Gaseous parameters including volumetric methane production rate (VMPR), CH 4 , CO 2 , and H 2 concentrations, and liquid parameters including pH, oxidation-reduction potential, volatile fatty acid (VFA), and total alkalinity (TA), bicarbonate alkalinity (BA), intermediate alkalinity (IA), and ammonia, were monitored. The coupling parameters, such as the CH 4 /CO 2 , VFA/BA, and BA/TA ratios were also used to evaluate stability. The dynamics of syntrophic acetate-oxidizing bacteria (SAOB), acetoclastic methanogens (AM), and hydrogenotrophic methanogens (HM) were analyzed by high-throughput sequencing. The main methanogenic bacteria were HM (Methanothermobacter) during the start-up period of OLR 0.5 gVS/(L ∙ d), while they were AM (Methanosarcina) during the stable period of OLR of 1.0 gVS/(L ∙ d). The VMPR of stable period was about 0.29 L/(L · d) with total VFA concentration below 100 mg/L, CH 4 /CO 2  > 1.3, and BA/TA>0.9. The first instability due to the accumulation of VFA and self-recovery due to syntrophic acetate oxidation occurred at an OLR of 1.5 gVS/(L ∙ d). The syntrophic acetate-oxidizing bacteria probably belong to genus S1 (family Thermotogaceae). The digestion failed at an OLR of 2.0 g VS/(L · d). H 2 was only detected during collapsed period instead of instable period. The total ammonia nitrogen loss and bicarbonate alkalinity (BA) reduction were the primary causes for the instability of AD of VW without effluent recirculation. Compared with single parameters, the CH 4 /CO 2 and BA/total alkalinity (TA) ratios are recommended as early warning indicators for engineering applications of thermophilic AD of VW. Copyright © 2018 Elsevier Ltd. All rights reserved.

Eu-Doped BaTiO3 Powder and Film from Sol-Gel Process with Polyvinylpyrrolidone Additive

PubMed Central

García-Hernández, Margarita; García-Murillo, Antonieta; de J. Carrillo-Romo, Felipe; Jaramillo-Vigueras, David; Chadeyron, Geneviève; De la Rosa, Elder; Boyer, Damien

2009-01-01

Transparent BaTiO3:Eu3+ films were prepared via a sol-gel method and dip-coating technique, using barium acetate, titanium butoxide, and polyvinylpyrrolidone (PVP) as modifier viscosity. BaTiO3:Eu3+ films ~500 nm thick, crystallized after thermal treatment at 700 ºC. The powders revealed spherical and rod shape morphology. The optical quality of films showed a predominant band at 615 nm under 250 nm excitation. A preliminary luminescent test provided the properties of the Eu3+ doped BaTiO3. PMID:19865533

Do flower color and floral scent of silene species affect host preference of Hadena bicruris, a seed-eating pollinator, under field conditions?

PubMed

Page, Paul; Favre, Adrien; Schiestl, Florian P; Karrenberg, Sophie

2014-01-01

Specialization in plant-insect interactions is an important driver of evolutionary divergence; yet, plant traits mediating such interactions are poorly understood. In this study, we investigated how flower color and floral scent are related to seed predation by a seed-eating pollinator. We used field-transplanted recombinant F2 hybrids between Silene latifolia and S. dioica that are the preferred and alternative hosts of the moth Hadena bicruris and crosses within these species for comparison. We scored seed predation and flower color and analyzed floral scent. Pinker S. dioica-like flowers and emission of α-pinene decreased the odds of seed predation while emission of benzyl acetate and 6-methyl-5-hepten-2-one increased the odds of seed predation. Emission of these compounds did not differ significantly between the two Silene species. Our results suggest that flower color plays an important role in the specific interaction of H. bicruris with its preferred host S. latifolia. The compounds α-pinene, benzyl acetate and 6-methyl-5-hepten-2-one could represent non-specific deterrents and attractants to ovipositing moths. Alternatively, emission of these compounds could be related to herbivory or pathogen attack and act as a signal for host quality. This would weaken the predictability of the plant's costs and benefits of the interaction and act to maintain an imperfect degree of specialization.

Do Flower Color and Floral Scent of Silene Species affect Host Preference of Hadena bicruris, a Seed-Eating Pollinator, under Field Conditions?

PubMed Central

Page, Paul; Favre, Adrien; Schiestl, Florian P.; Karrenberg, Sophie

2014-01-01

Specialization in plant–insect interactions is an important driver of evolutionary divergence; yet, plant traits mediating such interactions are poorly understood. In this study, we investigated how flower color and floral scent are related to seed predation by a seed-eating pollinator. We used field-transplanted recombinant F2 hybrids between Silene latifolia and S. dioica that are the preferred and alternative hosts of the moth Hadena bicruris and crosses within these species for comparison. We scored seed predation and flower color and analyzed floral scent. Pinker S. dioica-like flowers and emission of α-pinene decreased the odds of seed predation while emission of benzyl acetate and 6-methyl-5-hepten-2-one increased the odds of seed predation. Emission of these compounds did not differ significantly between the two Silene species. Our results suggest that flower color plays an important role in the specific interaction of H. bicruris with its preferred host S. latifolia. The compounds α-pinene, benzyl acetate and 6-methyl-5-hepten-2-one could represent non-specific deterrents and attractants to ovipositing moths. Alternatively, emission of these compounds could be related to herbivory or pathogen attack and act as a signal for host quality. This would weaken the predictability of the plant's costs and benefits of the interaction and act to maintain an imperfect degree of specialization. PMID:24905986

Terpenoids inhibit Candida albicans growth by affecting membrane integrity and arrest of cell cycle.

PubMed

Zore, Gajanan B; Thakre, Archana D; Jadhav, Sitaram; Karuppayil, S Mohan

2011-10-15

Anti-Candida potential of six terpenoids were evaluated in this study against various isolates of Candida albicans (n=39) and non-C. albicans (n=9) that are differentially susceptible to fluconazole. All the six terpenoids tested, showed excellent activity and were equally effective against isolates of Candida sps., tested in this study. Linalool and citral were the most effective ones, inhibiting all the isolates at ≤0.064% (v/v). Five among the six terpenoids tested were fungicidal. Time dependent kill curve assay showed that MFCs of linalool and eugenol were highly toxic to C. albicans, killing 99.9% inoculum within seven min of exposure, while that of citronellal, linalyl acetate and citral required 15min, 1h and 2h, respectively. FIC index values (Linalool - 0.140, benzyl benzoate - 0.156, eugenol - 0.265, citral - 0.281 and 0.312 for linalyl acetate and citronellal) and isobologram obtained by checker board assay showed that all the six terpenoids tested exhibit excellent synergistic activity with fluconazole against a fluconazole resistant strain of C. albicans. Terpenoids tested arrested C. albicans cells at different phases of the cell cycle i.e. linalool and LA at G1, citral and citronellal at S phase and benzyl benzoate at G2-M phase and induced apoptosis. Linalool, citral, citronellal and benzyl benzoate caused more than 50% inhibition of germ tube induction at 0.008%, while eugenol and LA required 0.032 and 0.016% (v/v) concentrations, respectively. MICs of all the terpenoids for the C. albicans growth were non toxic to HeLa cells. Terpenoids tested exhibited excellent activity against C. albicans yeast and hyphal form growth at the concentrations that are non toxic to HeLa cells. Terpenoids tested in this study may find use in antifungal chemotherapy, not only as antifungal agents but also as synergistic agents along with conventional drugs like fluconazole. Copyright © 2011 Elsevier GmbH. All rights reserved.

Ethyl 2-{4-[(1,5-dibenzyl-2,4-dioxo-2,3,4,5-tetra-hydro-1H-1,5-benzo-diazepin-3-yl)meth-yl]-1H-1,2,3-triazol-1-yl}acetate.

PubMed

Jabli, Hind; Kandri Rodi, Y; Ladeira, Sonia; Essassi, El Mokhtar; Ng, Seik Weng

2009-12-12

The reaction of 1,5-dibenzyl-3-propargyl-1,5-benzodiazepine-2,4-dione with ethyl azido-acetate in the presence of copper sulfate pentahydrate and sodium ascorbate leads to the formation of the title regioisomer, C(30)H(29)N(5)O(4), which features a phenyl-ene ring fused with a seven-membered diazepinyl ring. The latter ring adopts a boat conformation (with the methyl-triazolylacetate-bearing C atom as the prow and the fused-ring C atoms as the stern). The benzyl groups connected to the diazepinyl ring jprotrude from the sides; the methyl-triazolylacetate substituent occupies an axial position.

Design and synthesis of a novel series of [1-(4-hydroxy-benzyl)-1H-indol-5-yloxy]-acetic acid compounds as potent, selective, thyroid hormone receptor β agonists.

PubMed

Burkholder, Timothy P; Cunningham, Brian E; Clayton, Joshua R; Lander, Peter A; Brown, Matthew L; Doti, Robert A; Durst, Gregory L; Montrose-Rafizadeh, Chahrzad; King, Constance; Osborne, Harold E; Amos, Robert M; Zink, Richard W; Stramm, Lawrence E; Burris, Thomas P; Cardona, Guemalli; Konkol, Debra L; Reidy, Charles; Christe, Michael E; Genin, Michael J

2015-04-01

The design, synthesis, and structure activity relationships for a novel series of indoles as potent, selective, thyroid hormone receptor β (TRβ) agonists is described. Compounds with >50× binding selectivity for TRβ over TRα were generated and evaluation of compound 1c from this series in a model of dyslipidemia demonstrated positive effects on plasma lipid endpoints in vivo. Copyright © 2015 Elsevier Ltd. All rights reserved.

Airborne exposures to monoethanolamine, glycol ethers, and benzyl alcohol during professional cleaning: a pilot study.

PubMed

Melchior Gerster, Fabian; Brenna Hopf, Nancy; Pierre Wild, Pascal; Vernez, David

2014-08-01

A growing body of epidemiologic evidence suggests an association between exposure to cleaning products and respiratory dysfunction. Due to the lack of quantitative assessments of respiratory exposures to airborne irritants and sensitizers among professional cleaners, the culpable substances have yet to be identified. Focusing on previously identified irritants, our aims were to determine (i) airborne concentrations of monoethanolamine (MEA), glycol ethers, and benzyl alcohol (BA) during different cleaning tasks performed by professional cleaning workers and assess their determinants; and (ii) air concentrations of formaldehyde, a known indoor air contaminant. Personal air samples were collected in 12 cleaning companies, and analyzed by conventional methods. Nearly all air concentrations [MEA (n = 68), glycol ethers (n = 79), BA (n = 15), and formaldehyde (n = 45)] were far below (<1/10) of the corresponding Swiss occupational exposure limits (OEL), except for ethylene glycol mono-n-butyl ether (EGBE). For butoxypropanol and BA, no OELs exist. Although only detected once, EGBE air concentrations (n = 4) were high (49.48-58.72mg m(-3)), and close to the Swiss OEL (49mg m(-3)). When substances were not noted as present in safety data sheets of cleaning products used but were measured, air concentrations showed no presence of MEA, while the glycol ethers were often present, and formaldehyde was universally detected. Exposure to MEA was affected by its amount used (P = 0.036), and spraying (P = 0.000) and exposure to butoxypropanol was affected by spraying (P = 0.007) and cross-ventilation (P = 0.000). Professional cleaners were found to be exposed to multiple airborne irritants at low concentrations, thus these substances should be considered in investigations of respiratory dysfunctions in the cleaning industry; especially in specialized cleaning tasks such as intensive floor cleaning. © The Author 2014. Published by Oxford University Press on behalf of the British Occupational Hygiene Society.

Light-induced biochemical variations in secondary metabolite production and antioxidant activity in callus cultures of Stevia rebaudiana (Bert).

PubMed

Ahmad, Naveed; Rab, Abdur; Ahmad, Nisar

2016-01-01

Stevia rebaudiana (S. rebaudiana) is a very important species with worldwide medicinal and commercial uses. Light is one of the major elicitors that fluctuate morphogenic potential and biochemical responses. In the present study, we investigated the effect of various spectral lights on biomass accumulation and secondary metabolite production in callus cultures of S. rebaudiana. Leaf explants were placed on Murashige and Skoog (MS) medium and exposed to various spectral lights. 6-Benzyle adenine (BA) and 2, 4-dichlorophenoxy acetic acid (2, 4-D; 2.0 mgl(-1)) were used for callus induction. The control light (16/8h) produced optimum callogenic response (92.73%) than other colored lights. Compared to other colored lights, control grown cultures displayed maximum biomass accumulation (5.78 gl(-1)) during a prolonged log phase at the 18th day of growth kinetics. Cultures grown under blue light enhanced total phenolic content (TPC; 102.32 μg/g DW), total flavonoid content (TFC; 22.07 μg/g DW) and total antioxidant capacity (TAC; 11.63 μg/g DW). On the contrary, green and red lights improved reducing power assay (RPA; 0.71Fe(II)g(-1) DW) and DPPH-radical scavenging activity (DRSA; 80%). Herein, we concluded that the utilization of colored lights is a promising strategy for enhanced production of antioxidant secondary metabolites in callus cultures of S. rebaudiana. Copyright © 2015 Elsevier B.V. All rights reserved.

Interaction of antimicrobial preservatives with blow-fill-seal packs: correlating sorption with solubility parameters.

PubMed

Amin, Aeshna; Dare, Manish; Sangamwar, Abhay; Bansal, Arvind Kumar

2012-01-01

The aim of this work was to study the interaction of four commonly used ophthalmic antimicrobial preservatives [benzyl alcohol (BA), chlorbutol (CBL), benzalkonium chloride (BKC), and chlorhexidine gluconate (CG)] with Blow-Fill-Seal (BFS) packs. Effect of packaging material [low-density polyethylene (LDPE), polypropylene (PP)], humidity (25% RH, 75% RH) and concentration (0.5, 1.0, 2.0 mM BA/CBL in LDPE) was studied. BKC and CG gave negligible loss (<4%) in BFS packs over a period of 3 months. BA and CBL, however, gave marked losses in LDPE (ca. 70-90%) and PP (ca. 7-25%) packs. Humidity did not have any effect on the sorption loss of any preservative. Loss of BA switched from Case II to anomalous behavior with increasing initial concentration. A two-stage sorption behavior was inherent at all concentrations. Loss of CBL followed anomalous behavior with biphasic kinetics of loss. It was concluded that all the four preservatives were appropriate for use in PP BFS packs. However, only BKC and CG were amenable to be used in LDPE BFS packs. Lastly, an empirical expression consisting of the "solubility parameter distance" and "molar volume" of preservatives was developed to correlate the preservative loss in LDPE with the physicochemical properties of the preservatives.

Full-scale chamber investigation and simulation of air freshener emissions in the presence of ozone.

PubMed

Liu, Xiaoyu; Mason, Mark; Krebs, Kenneth; Sparks, Leslie

2004-05-15

Volatile organic compound (VOC) emissions from one electrical plug-in type of pine-scented air freshener and their reactions with O3 were investigated in the U.S. Environmental Protection Agency indoor air research large chamber facility. Ozone was generated from a device marketed as an ozone generator air cleaner. Ozone and oxides of nitrogen concentrations and chamber conditions such as temperature, relative humidity, pressure, and air exchange rate were controlled and/or monitored. VOC emissions and some of the reaction products were identified and quantified. Source emission models were developed to predict the time/concentration profiles of the major VOCs (limonene, alpha-pinene, beta-pinene, 3-carene, camphene, benzyl propionate, benzyl alcohol, bornyl acetate, isobornyl acetate, and benzaldehyde) emitted bythe air freshener. Gas-phase reactions of VOCs from the air freshener with O3 were simulated by a photochemical kinetics simulation system using VOC reaction mechanisms and rate constants adopted from the literature. The concentration-time predictions were in good agreement with the data for O3 and VOCs emitted from the air freshener and with some of the primary reaction products. Systematic differences between the predictions and the experimental results were found for some species. Poor understanding of secondary reactions and heterogeneous chemistry in the chamber is the likely cause of these differences. The method has the potential to provide data to predict the impact of O3/VOC interactions on indoor air quality.

Effects of light and growth regulators on adventitious bud formation in horseradish (Armoracia rusticana).

PubMed

Kamada, H; Tachikawa, Y; Saitou, T; Harada, H

1995-07-01

To clarify that the presence of Ri T-DNA genes are not prerequisite for the light-induced bud formation in horseradish (Armoracia rusticana) hairy roots, leaf and root segments of nontransformed horseradish plants were used as explants. Bud formation from nontransformed tissues was observed in hormone-free medium under 16 h daylight conditions, but not under continuous darkness. To investigate the effects of growth regulators on bud formation, leaf and root explants were treated with auxin (1-naphthaleneacetic acid; NAA) and / or cytokinin (6-benzyl-aminopurine; BA). The most effective treatment in the dark to stimulate bud formation was BA at 1 mg·1(-1). These results show that adventitious bud formation in horseradish can be induced by light and growth regulators, and especially cytokinin, may be involved in bud formation, irrespective of whether the tissues were transformed with Ri T-DNA.

Synthesis and characterization of starch-g-poly(vinyl acetate-co-butyl acrylate) bio-based adhesive for wood application.

PubMed

Zia-Ud-Din; Chen, Lei; Ullah, Ikram; Wang, Peng Kai; Javaid, Allah Bakhsh; Hu, Chun; Zhang, Mengchao; Ahamd, Ishtiaq; Xiong, Hanguo; Wang, Zhenjiong

2018-07-15

Enhancing the performance of wood adhesive is important for its industrial applications. Accordingly, we designed and demonstrated the use of two co-monomers vinyl acetate (VAc) and butyl acrylate (BA) for promoting the graft copolymerization while improving the bonding performance of wood adhesive. The results showed that the addition of co-monomers in the ratio of VAc/BA 6:4 (v/v, volume basis of VAc) could improve the shear strength to 6.68MPa and 3.32MPa in dry and wet states, respectively. 1 H-nuclear magnetic resonance ( 1 H NMR) and fourier transform infrared spectroscopy (FT-IR) analysis revealed successful graft copolymerization reaction while the morphologies were observed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Furthermore, the grafting reaction and thermal stabilities of wood adhesive were analyzed by X-ray photoelectron spectroscopy (XPS) and thermogravimetric analysis (TGA). The results showed that the properties of wood adhesive could improve dramatically by using two co-monomers VAc and BA during the graft copolymerization reaction. Copyright © 2018 Elsevier B.V. All rights reserved.

Reduction of Line Edge Roughness of Polystyrene-block-Poly(methyl methacrylate) Copolymer Nanopatterns By Introducing Hydrogen Bonding at the Junction Point of Two Block Chains.

PubMed

Lee, Kyu Seong; Lee, Jaeyong; Kwak, Jongheon; Moon, Hong Chul; Kim, Jin Kon

2017-09-20

To apply well-defined block copolymer nanopatterns to next-generation lithography or high-density storage devices, small line edge roughness (LER) of nanopatterns should be realized. Although polystyrene-block-poly(methyl methacrylate) copolymer (PS-b-PMMA) has been widely used to fabricate nanopatterns because of easy perpendicular orientation of the block copolymer nanodomains and effective removal of PMMA block by dry etching, the fabricated nanopatterns show poorer line edge roughness (LER) due to relatively small Flory-Huggins interaction parameter (χ) between PS and PMMA chains. Here, we synthesized PS-b-PMMA with urea (U) and N-(4-aminomethyl-benzyl)-4-hydroxymethyl-benzamide (BA) moieties at junction of PS and PMMA chains (PS-U-BA-PMMA) to improve the LER. The U-BA moieties serves as favorable interaction (hydrogen bonding) sites. The LER of PS line patterns obtained from PS-U-BA-PMMA was reduced ∼25% compared with that obtained from neat PS-b-PMMA without BA and U moieties. This is attributed to narrower interfacial width induced by hydrogen bonding between two blocks, which is confirmed by small-angle X-ray scattering. This result implies that the introduction of hydrogen bonding into block copolymer interfaces offers an opportunity to fabricate well-defined nanopatterns with improved LER by block copolymer self-assembly, which could be a promising alternative to next-generation extreme ultraviolet lithography.

2-Nitro­benzyl 2-chloro­acetate

PubMed Central

Zhu, Kai; Liu, Hui; Wang, Yan-Hua; Han, Ping-Fang; Wei, Ping

2009-01-01

In the mol­ecule of the title compound, C9H8ClNO4, an intra­molecular C—H⋯O inter­action results in the formation of a near-planar (r.m.s. deviation 0.002 Å) five-membered ring, which is oriented at a dihedral angle of 4.07 (4)° with respect to the adjacent aromatic ring. In the crystal structure, inter­molecular C—H⋯O inter­actions link the mol­ecules into a two-dimensional network. PMID:21577790

Discovery of Fevipiprant (NVP-QAW039), a Potent and Selective DP2 Receptor Antagonist for Treatment of Asthma

PubMed Central

2017-01-01

Further optimization of an initial DP2 receptor antagonist clinical candidate NVP-QAV680 led to the discovery of a follow-up molecule 2-(2-methyl-1-(4-(methylsulfonyl)-2-(trifluoromethyl)benzyl)-1H-pyrrolo[2,3-b]pyridin-3-yl)acetic acid (compound 11, NVP-QAW039, fevipiprant), which exhibits improved potency on human eosinophils and Th2 cells, together with a longer receptor residence time, and is currently in clinical trials for severe asthma. PMID:28523115

The role of hormone transport and metabolism in apical dominance in oats

NASA Technical Reports Server (NTRS)

Harrison, M. A.; Kaufman, P. B.

1984-01-01

14C-benzyladenine (BA) and 14C-indole-3-acetic acid (IAA) were used to study hormone transport to the tiller bud and hormone catabolism in excised oat stem segments. Acropetal BA transport was greatest from upright stem segments to tiller buds suppressed by apical dominance. IAA, abscisic acid (ABA), and C2H4 inhibited BA transport to the tiller bud. IAA transport to the tiller bud site was inhibited by BA, C2H4, or after gravistimulation, which affected BA transport to a lesser extent than IAA transport. Multiple peaks of radioactivity were observed in 14C-BA- or 14C-IAA-treated stem segments after 9 h of transport. IAA, ABA, and C2H4 promoted BA catabolism. Auxin, ABA, and C2H4 may inhibit tiller bud release by inhibiting cytokinin transport to the tiller bud and by promoting cytokinin catabolism. Gravistimulation may promote tiller release by inhibiting IAA transport to the tiller bud and allowing cytokinins to accumulate there preferentially.

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.

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

Polyakova, I. N., E-mail: polyakova@igic.ras.ru; Poznyak, A. L.; Sergienko, V. S.

Four Cu(II) complexes with the RR,SS-Edds{sup 4-} and SS-HEdds{sup 3-} anions are synthesized, and their crystal structures are studied. In the compounds [Cu2(RR,SS-Edds)] . 6H{sub 2}O (I) and Ba2[Cu(RR,SS-Edds)](ClO{sub 4}){sub 2} . 8H{sub 2}O (II), the ligand forms hexacoordinate chelate [Cu(Edds)]{sup 2-} complexes with the N atoms and O atoms of the propionate groups in the equatorial positions and the O atoms of the acetate groups in the axial vertices. In the compounds Ba[Cu(SS-HEdds)]ClO{sub 4} . 2H{sub 2}O (III) and Ba3[Cu2(RR,SS-Edds){sub 2}](ClO{sub 4}){sub 2} . 6H{sub 2}O (IV), one of the propionate arms, the protonated arm in III and themore » deprotonated arm in IV, does not enter into the coordination sphere of the Cu atom. An acetate arm moves to its position in the equatorial plane, and the free axial vertex is occupied by an O atom of the perchlorate ion. In I-IV, the lengths of the equatorial Cu-N and Cu-O bonds fall in the ranges 1.970-2.014 and 1.921-1.970 A, respectively. The axial Cu-O bonds with the acetate groups and ClO{sub 4}{sup -} anions are elongated to 2.293-2.500 and 2.727-2.992 A, respectively. In structure I, the second Cu atom acts as a counterion forming bonds with the O atoms of two water molecules and three O atoms of the Edds ligands. In II-IV, the Ba{sup 2+} cations are hydrated and bound to the O atoms of the anionic complexes and (except for one of the cations in IV) ClO{sub 4}{sup -} anions. The coordination number of the Ba cations is nine. The structural units in I-IV are connected into layers. In I, an extended system of hydrogen bonds links the layers into a framework. In II and III, the layers are linked only by weak hydrogen bonds, one bond per structural unit. In IV, ClO{sub 4}{sup -} anions are bound to the Ba and Cu atoms of neighboring layers, thus serving as bridges between the layers.« less

Microbial and geochemical investigations of dissolved organic carbon and microbial ecology of native waters from the Biscayne and Upper Floridan Aquifers

USGS Publications Warehouse

Lisle, John T.; Harvey, Ron W.; Aiken, George R.; Metge, David W.

2010-01-01

Groundwater resources in the United States are under ever-increasing demands for potable, irrigation, and recreational uses. Additionally, aquifer systems are being used or targeted for use as storage areas for treated surface waters and (or) groundwaters via injection (for example, aquifer storage and recovery). To date, the influence that the nutrients, including carbon, in the injected water have on native microbial communities and the biogeochemistry in the subsurface zones used for storage of the injectate has not been determined. In this report, we describe a series of experiments that establishes a baseline dataset for the quantity and quality of organic and inorganic carbon and nutrients in the Biscayne Aquifer (BA) and Upper Floridan Aquifer (UFA) in south Florida. The most significant differences between the BA (26 meters below surface) and UFA (366 meters below surface) are the average specific conductance (0.552 and 6.12 microsiemens per centimeter, respectively), dissolved oxygen (1.6 and 0 milligrams per liter, respectively), and oxidation-reduction potential (40.3 and -358 millivolts, respectively). The dissolved organic carbon from the BA is characterized by carbon originating from terrestrial sources and microbial activities, while the UFA has a distinctive microbial signature. Acetate and lactate are the dominant carbon constituents in both aquifers. Additionally, components of the dissolved organic carbon from the UFA have a total trihalomethane-formation potential that is approximately threefold greater than the maximum contaminat level of 80 micrograms per liter established by the U.S. Environmental Protection Agency. The average native bacterial abundances in the aquifers are similar with 4.69x10^4 cells per milliliter in the BA and 1.33x10^4 cells per milliliter in the UFA. The average bacteriophage abundances are also similar with 1.15x10^5 virus-like particles in the BA and 1.92x10^5 virus-like particles in the UFA. Interestingly, ciliated protozoa are present in both aquifers. The average abundance of ciliates in the BA (2.97x10^3 ciliates per milliliter) is approximately twentyfold greater than abundances in the UFA (1.39x10^2 ciliates per milliliter). Collectively, these data indicate that microbial processes are the dominant contributor to the cycling of carbon and inorganic carbon in the BA and may be the only carbon cycling process in the UFA, as this aquifer has not had a terrestrial influx of carbon for more than 15,000 years. The rates of carbon, in the form of acetate, utilization by the native microbial communities are significantly different between the two aquifers. Based on data from 14C-acetate-utilization experiments, the microbial communities in the BA turn over the native acetate in 2.5 years, whereas communities in the UFA turn over native acetate in 6.8 years. These data support the hypothesis derived from the microbial-abundance data, in that the carbon for bacterial maintainence and growth is recycled from bacterial biomass released during cell lysis, especially in the UFA. An in situ diffusion chamber was designed to retain bacterial cells within the chamber while allowing native water constituents to move through the chamber. A series of 1-week deployments of chambers filled with fluorescent beads, inactivated native bacteria and laboratory grown and viable bacteria into the UFA, permitted by the State of Florida Environmental Protection Agency, was successfully completed. This was the first time this type of deployment into an aquifer system that is used for potable water supply has been permitted within the United States. This technology will allow, for the first time, in situ studies on the survival of microbial indicators of fecal pollution and true pathogens in groundwater systems.

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

PubMed

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

2013-09-01

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

Preparation and Dielectric Measurements of the Rare Earth Green Phases R2BaCuO(5-x) (R = Y, Sm, Gd, Dy, Ho, Er, Yb)

NASA Technical Reports Server (NTRS)

Gonzalez-Titman, Carlos

1994-01-01

It has been demonstrated that R2BaCuO(5-x) (R = Y, Sm, Gd, Dy, Ho, Er, Yb) does not undergo significant densification unless the sintering temperatures are near the incongruent melting point or the sintering times are long. Good quality powders of Y2BaCuO(5-x) have been synthesized by using oxide raw materials or precursors such as acetates and nitrates. The acetates- and the nitrates-derived yttrium green phase resulted in finer particle sizes, acceptable dielectric properties and lower melting temperatures than those processed via oxide raw materials. The hot pressing technique has been employed to produce a dense R2BaCuO(5-x) (R=Y,Gd) substrate with satisfactory dielectric properties. Reactivity to reducing conditions, i.e. graphite die, limited the optimization of the properties. A high sensitivity to the annealing atmosphere has been demonstrated in Y2BaCuO,.,,. Oxygen treatment at 950 OC has been shown to improve the dielectric properties while treatment in nitrogen, at the same temperature, degraded desirable properties. A high sensitivity to the annealing atmosphere has been demonstrated in Y2BaCuO(5-x). Oxygen treatment at 950 C has been shown to improve the dielectric properties while treatment in nitrogen, at the same temperature, degraded desirable properties. The dielectric constants of the rare earth green phases R2BaCuO(5-x) were found to be low. Relaxation peaks were detected at low temperatures (T less than 150 K) and at high temperatures (150 less than T greater than 420 K). The dielectric losses and conductivities at 77 K were measured to be in the range of 10(exp -4) and 10(exp -12) (Omega-cm)(exp -1), respectively. Many parameters were found to exhibit dependencies on the rare earth cation sizes.

A new validated method for the simultaneous determination of benzocaine, propylparaben and benzyl alcohol in a bioadhesive gel by HPLC.

PubMed

Pérez-Lozano, P; García-Montoya, E; Orriols, A; Miñarro, M; Ticó, J R; Suñé-Negre, J M

2005-10-04

A new HPLC-RP method has been developed and validated for the simultaneous determination of benzocaine, two preservatives (propylparaben (nipasol) and benzyl alcohol) and degradation products of benzocaine in a semisolid pharmaceutical dosage form (benzocaine gel). The method uses a Nucleosil 120 C18 column and gradient elution. The mobile phase consisted of a mixture of methanol and glacial acetic acid (10%, v/v) at different proportion according to a time-schedule programme, pumped at a flow rate of 2.0 ml min(-1). The DAD detector was set at 258 nm. The validation study was carried out fulfilling the ICH guidelines in order to prove that the new analytical method, meets the reliability characteristics, and these characteristics showed the capacity of analytical method to keep, throughout the time, the fundamental criteria for validation: selectivity, linearity, precision, accuracy and sensitivity. The method was applied during the quality control of benzocaine gel in order to quantify the drug (benzocaine), preservatives and degraded products and proved to be suitable for rapid and reliable quality control method.

A new irreversible enzyme-aided esterification method in organic solvents.

PubMed

Jeromin, Günter E; Zoor, Annegreth

2008-05-01

A new irreversible esterification method for carboxylic acids catalyzed by a lipase from Candida antarctica (Novozyme 435) in organic solvents has been developed. The water produced during the process is chemically destroyed by a corresponding ester of acetoacetate, which acts as a sacrificial substrate in this reaction. The flavour esters isobutyl acetate, methyl butyrate, ethyl butyrate and benzyl butyrate were synthesized either in small scale (0.05 mol) or large scale (1 mol). The yields range from 82 to 92% within 24 h at 52 degrees C. Optimal molar ratios of reactants were 1:1:1 (carboxylic acid:alcohol:acetoacetate).

Improvement in Wood Bonding Strength of Poly (Vinyl Acetate-Butyl Acrylate) Emulsion by Controlling the Amount of Redox Initiator

PubMed Central

Zhang, Yun; Pang, Bo; Yang, Sen; Fang, Wei; Yang, Sheng; Yuan, Tong-Qi; Sun, Run-Cang

2018-01-01

Polyvinyl acetate emulsion adhesive has been widely used due to its good bonding performance and environmentally friendly properties. Indeed, the bonding performance can be further improved by copolymerizing with other monomers. In this study, the effect of the adjunction of redox initiator (hydrogen peroxide–tartaric acid, H2O2–TA) on the properties of the poly (vinyl acetate-butyl acrylate) (P (VAc–BA)) emulsion adhesive was investigated. With increasing dosage, the reaction became more complete and the obtained film was more compact, as identified via SEM. The core-shell structure of the emulsion particles was confirmed via TEM. Results indicate that while the initiator content increased from 0.5 to 1.0%, a clearer core-shell structure was obtained and the bonding strength of the plywood improved from 2.34 to 2.97 MPa. With the further incorporation of H2O2–TA (i.e., 1.5%), the bonding performance deteriorated. The optimum wood bonding strength (2.97 MPa) of the prepared P (VAc-BA) emulsion adhesive was even better than that (2.55 MPa) of a commercial PVAc emulsion adhesive, suggesting its potential application for the wood industry. PMID:29316725

Pomegranate juice adulteration by addition of grape or peach juices.

PubMed

Nuncio-Jáuregui, Nallely; Calín-Sánchez, Ángel; Hernández, Francisca; Carbonell-Barrachina, Ángel A

2014-03-15

Pomegranate juice has gained a high reputation for its health properties and consequently is now a highly demanded product. However, owing to the limited production and high price of fresh pomegranates, adulteration of pomegranate juice seems to be happening. Hence it is imperative to establish criteria for detecting adulteration. Addition of grape juice significantly increased the contents of Ca, Mg and Fe and especially tartaric acid and proline and simultaneously decreased the content of K. Addition of peach juice up to 10% (v/v) only resulted in a significant increase in sucrose content. Regarding the volatile composition, adulteration of pomegranate juice with grape juice resulted in significant increases in acetic acid, isoamyl butyrate and especially 1-hexanol and linalool, while adulteration with peach juice resulted in significant increases in butyl acetate, isobutyl butyrate, benzyl acetate and especially isoamyl butyrate. The control protocols used in this study can serve as a basis for identification of pomegranate juice adulteration. It is important to highlight that it is necessary to simultaneously analyze and have results from several parameters to conclude that a particular pomegranate juice has been adulterated by mixing with another fruit juice. © 2013 Society of Chemical Industry.

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

NASA Astrophysics Data System (ADS)

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

1997-09-01

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

Effect of addition of butyl benzyl phthalate plasticizer and zinc oxide nanoparticles on mechanical properties of cellulose acetate butyrate/organoclay biocomposite

NASA Astrophysics Data System (ADS)

Putra, B. A. P.; Juwono, A. L.; Rochman, N. T.

2017-07-01

Plastics as packaging materials and coatings undergo increasing demands globally each year. This pose a serious problem to the environment due to its difficulty to degrade. One solution to addressing the problem of plastic wastes is the use of bioplastics. According to the European Organization Bioplastic, one of the biodegradable plastics is derivative of cellulose. To improve mechanical properties of bioplastic, biocomposites are made with the addition of certain additives and fillers. The aim of this study is to investigate the effect of butyl benzyl phthalate plasticizer (BBP) and ZnO nanoparticles addition on mechanical properties of cellulose acetate butyrate (CAB) / organoclay biocomposite. ZnO nanoparticles synthesized from commercial ZnO precursor by using sol-gel size reduction method. ZnO was dissolved in a solution of citric acid in the ratio 1:1 to 1:5 to form zinc citrate. Zinc citrate then decomposed by calcination at temperature of 600oC. ZnO nanoparticles with an average size of 44.4 nm is obtained at a ratio of 1: 2. The addition of ZnO nanoparticles and BBP plasticizer was varied to determine the effect on the mechanical properties of biocomposite. The addition of 10 - 15 %wt ZnO nanoparticles and 30 - 40 %wt BBP plasticizer was studied to determine the effect on the tensile strength, elongation, and modulus elasticity of the biocomposites. Biocomposite films were made by using solution casting method with acetone as solvent. The addition of plasticizer BBP and ZnO nanoparticles by 30% and 10% made biocomposite has a tensile strength of 2.223 MPa.

Microbial release of 226Ra2+ from (Ba,Ra)SO4 sludges from uranium mine wastes.

PubMed Central

Fedorak, P M; Westlake, D W; Anders, C; Kratochvil, B; Motkosky, N; Anderson, W B; Huck, P M

1986-01-01

226Ra2+ is removed from uranium mine effluents by coprecipitation with BaSO4. (Ba,Ra)SO4 sludge samples from two Canadian mine sites were found to contain active heterotrophic populations of aerobic, anaerobic, denitrifying, and sulfate-reducing bacteria. Under laboratory conditions, sulfate reduction occurred in batch cultures when carbon sources such as acetate, glucose, glycollate, lactate, or pyruvate were added to samples of (Ba,Ra)SO4 sludge. No external sources of nitrogen or phosphate were required for this activity. Further studies with lactate supplementation showed that once the soluble SO4(2-) in the overlying water was depleted, Ba2+ and 226Ra2+ were dissolved from the (Ba,Ra)SO4 sludge, with the concurrent production of S2-. Levels of dissolved 226Ra2+ reached approximately 400 Bq/liter after 10 weeks of incubation. Results suggest that the ultimate disposal of these sludges must maintain conditions to minimize the activity of the indigenous sulfate-reducing bacteria to ensure that unacceptably high levels of 226Ra2+ are not released to the environment. PMID:3752993

Spin-Coating and Characterization of Multiferroic MFe2O4 (M=Co, Ni) / BaTiO3 Bilayers

NASA Astrophysics Data System (ADS)

Quandt, Norman; Roth, Robert; Syrowatka, Frank; Steimecke, Matthias; Ebbinghaus, Stefan G.

2016-01-01

Bilayer films of MFe2O4 (M=Co, Ni) and BaTiO3 were prepared by spin coating of N,N-dimethylformamide/acetic acid solutions on platinum coated silicon wafers. Five coating steps were applied to get the desired thickness of 150 nm for both the ferrite and perovskite layer. XRD, IR and Raman spectroscopy revealed the formation of phase-pure ferrite spinels and BaTiO3. Smooth surfaces with roughnesses in the order of 3 to 5 nm were found in AFM investigations. Saturation magnetization of 347 emu cm-3 for the CoFe2O4/BaTiO3 and 188 emu cm-3 for the NiFe2O4/BaTiO3 bilayer, respectively were found. For the CoFe2O4/BaTiO3 bilayer a strong magnetic anisotropy was observed with coercivity fields of 5.1 kOe and 3.3 kOe (applied magnetic field perpendicular and parallel to film surface), while for the NiFe2O4/BaTiO3 bilayer this effect is less pronounced. Saturated polarization hysteresis loops prove the presence of ferroelectricity in both systems.

Production and optimisation of rosmarinic acid by Satureja hortensis L. callus cultures.

PubMed

Tepe, Bektas; Sokmen, Atalay

2007-11-01

In this study, production and optimisation of rosmarinic acid, a phenolic acid and an economically important metabolite, was investigated in the callus cultures established from the mature seeds of Satureja hortensis L. (summer savory) plant. Gamborg's B5 basal medium, supplemented with indol butyric acid (IBA) (1.00 mg L(-1)), N6-benzyl aminopurine (6-BA) (1.00 mg L(-1)) and sucrose (2.5%, w/v), was employed for the establishment and maintenance of the callus cultures. Applications were individually prepared by preparing the media containing different IBA/6-BA combinations and sucrose concentrations. All of the applications were carried out in the continuous dark. In the applications, where the effects of IBA/6-BA combinations on the growth and rosmarinic acid accumulation were assayed (1-15 applications), the highest biomass yield was obtained from the medium supplemented with 1.00 mg L(-1) IBA and 5.00 mg L(-1) 6-BA. In the case of the rosmarinic acid accumulation, an opposite relationship was determined between the growth and rosmarinic acid production. While the highest biomass yield was obtained from the medium containing 1.00 mg L(-1) IBA and 5.00 mg L(-1) 6-BA, the highest rosmarinic acid accumulation was obtained from the medium supported with 1.00 mg L(-1) IBA and 1.00 mg L(-1) 6-BA. In the applications where the effects of sucrose concentrations on the growth and rosmarinic acid accumulation were examined, the highest biomass yield was obtained from the medium which is supplemented with 5.0% (w/v) sucrose. In this category, the highest rosmarinic acid accumulation was obtained from the medium which is supported with 3.0% (w/v) sucrose. According to the experiments carried out with the wild S. hortensis, it is found to have 25.02+/-1.21 mg g(-1) rosmarinic acid. No differentiation was observed in any callus during the course of this study.

In vitro propagation of jojoba.

PubMed

Llorente, Berta E; Apóstolo, Nancy M

2013-01-01

Jojoba (Simmondsia chinensis (Link) Schn.) is a nontraditional crop in arid and semi-arid areas. Vegetative propagation can be achieved by layering, grafting, or rooting semi-hardwood cuttings, but the highest number of possible propagules is limited by the size of the plants and time of the year. Micropropagation is highly recommended strategy for obtaining jojoba elite clones. For culture initiation, single-node explants are cultivated on Murashige and Skoog medium (MS) supplemented with Gamborg's vitamins (B5), 11.1 μM BA (N(6)-benzyl-adenine), 0.5 μM IBA (indole-3-butyric acid), and 1.4 μM GA(3) (gibberellic acid). Internodal and apical cuttings proliferate on MS medium containing B5 vitamins and 4.4 μM BA. Rooting is achieved on MS medium (half strength mineral salt) amended with B5 vitamins and 14.7 μM IBA during 7 days and transferred to develop in auxin-free rooting medium. Plantlets are acclimatized using a graduated humidity regime on soil: peat: perlite (5:1:1) substrate. This micropagation protocol produces large numbers of uniform plants from selected genotypes of jojoba.

An easy access to nanocrystalline alkaline earth metal fluorides - just by shaking

NASA Astrophysics Data System (ADS)

Dreger, M.; Scholz, G.; Kemnitz, E.

2012-04-01

High energy ball milling as fast, direct and solvent free method allows an easy access to nanocrystalline alkaline earth metal fluorides MF2 (M: Mg, Ca, Sr, Ba). Comparable metal sources (acetates, carbonates, hydroxides, alkoxides) were used for the reaction with NH4F as fluorinating agent. Even very simple manual shaking experiments between NH4F and the corresponding hydroxides in the stoichiometric ratio (M:F = 1:2, M: Ca, Sr, Ba) give phase pure fluorides. Moreover, comparable classical thermal reactions in closed crucibles at higher temperatures provide phase pure crystalline fluorides in nearly all cases as well.

Dielectric and ferroelectric properties of highly (100)-oriented (Na 0.5Bi 0.5) 0.94Ba 0.06TiO 3 thin films grown on LaNiO 3/γ-Al 2O 3/Si substrates by chemical solution deposition

NASA Astrophysics Data System (ADS)

Guo, Yiping; Akai, Daisuke; Sawada, Kazauki; Ishida, Makoto

2008-07-01

A (Na 0.5Bi 0.5) 0.94Ba 0.06TiO 3 chemical solution was prepared by using barium acetate, nitrate of sodium, nitrate of bismuth, and Ti-isopropoxide as raw materials. A white precipitation appeared during the preparation was analyzed to be Ba(NO 3) 2. We found that ethanolamine is a very effective coordinating ligand of Ba 2+. A transparent and stable (Na 0.5Bi 0.5) 0.94Ba 0.06TiO 3 precursor chemical solution has been achieved by using ethanolamine as a ligand of Ba 2+. (Na 0.5Bi 0.5) 0.94Ba 0.06TiO 3 films were grown on LaNiO 3/γ-Al 2O 3/Si substrates. Highly (100)-oriented (Na 0.5Bi 0.5) 0.94Ba 0.06TiO 3 films were obtained in this work due to lattice match growth. The dielectric, ferroelectric and insulative characteristics against applied field were studied. The conduction current shows an Ohmic conduction behavior at lower voltages and space-charge-limited behavior at higher voltages, respectively. These results indicate that, the (Na 0.5Bi 0.5) 0.94Ba 0.06TiO 3 film is a promising lead-free ferroelectric film.

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.

Data Fusion Analysis For Test Validation System

DTIC Science & Technology

2009-11-16

triethyl phosphate (TEP), methyl salicylate (MeS), and acetic acid (AA). A total of 29 release scenarios were conducted: fifteen TEP releases of 30...N2 - north second. bA - 2, 3, 6, 7, 10, and 11; B - 1 through 12; NA - not available. cTEP - triethyl phosphate; MeS - methyl salicylate ; AA

Adsorption of Benzoic Acid in Aqueous Solution by Bagasse Fly Ash

NASA Astrophysics Data System (ADS)

Suresh, S.

2012-09-01

This paper reports the studies on the benzoic acid (BA) onto bagasse fly ash (BFA) was studied in aqueous solution in a batch system. Physico-chemical properties including surface area, surface texture of the GAC before and after BA adsorption onto BFA were analysed using X-ray diffractometer (XRD), scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX). The optimum initial pH for the adsorption of BA was found to be 5.56. The adsorbent dose was 10 g/l for BFA and the equilibrium time 8 h of reaction. Pseudo first and second order models were used to find the adsorption kinetics. It was found that intraparticle diffusion played important role in the adsorption mechanisms of BA and the adsorption kinetics followed pseudo-second order kinetic model rather than the pseudo first order kinetic model. Isotherm data were generated for BA solution having initial concentrations of BA in the range of 10-200 mg/l for the BFA dosage of 10 g/l at temperatures of 288, 303, and 318 K. The adsorption of BA onto BFA was favorably influenced by an increase in temperature. Equilibrium data were well represented by the Redlich-Peterson isotherm model. Values of the change in entropy ( ΔS 0), heat of adsorption ( ΔH 0) for adsorption of BA on BFA was found to be 120.10 and 19.61 kJ/mol respectively. The adsorption of BA onto BFA was an endothermic reaction. Desorption of BA from BFA was studied by various solvents method. Acetic acid was found to be a better eluant for desorption of BA with a maximum desorption efficiency of 55.2 %. Owing to its heating value, spent BFA can be used as a co-fuel for the production of heat in boiler furnaces.

Organotin(IV) carboxylates based on 2-(1,3-dioxo-1H-benzo[de]isoquinolin-2(3H)-yl)acetic acid: Syntheses, crystal structures, luminescent properties and antitumor activities

NASA Astrophysics Data System (ADS)

Xiao, Xiao; Liang, Jingwen; Xie, Jingyi; Liu, Xin; Zhu, Dongsheng; Dong, Yuan

2017-10-01

Organotin carboxylates based on an amide carboxylic acid 2-(1,3-dioxo-1H-benzo[de]isoquinolin-2(3H)-yl)acetic acid (HL): [(Bn2Sn)2O2L]2·2C6H6 (1) (Bn = benzyl group) and (Ph2Sn)(L)2 (2) were synthesized and characterized by elemental analysis, IR, 1H, 13C, 119Sn NMR spectroscopy and X-ray crystallography diffraction analysis. Complex 1 is dimeric carboxylate tetraorganodistannoxane and show a "ladder-like" molecular structure. Complex 2 is a dialkyltin carboxylate monomer possessing crystallographically imposed two-fold symmetry. Ligand in 1 and 2 adopts unidentate and bidentate coordination respectively. Both 1 and 2 form 1D, 2D and 3D supramolecular organizations in the solid state mediated through Csbnd H⋯O and π⋯π interactions which are discussed in detail. The luminescent properties and preliminary antitumor activities about this series of complexes were also studied.

Simultaneous structure-activity studies and arming of natural products by C-H amination reveal cellular targets of eupalmerin acetate.

PubMed

Li, Jing; Cisar, Justin S; Zhou, Cong-Ying; Vera, Brunilda; Williams, Howard; Rodríguez, Abimael D; Cravatt, Benjamin F; Romo, Daniel

2013-06-01

Natural products have a venerable history of, and enduring potential for the discovery of useful biological activity. To fully exploit this, the development of chemical methodology that can functionalize unique sites within these complex structures is highly desirable. Here, we describe the use of rhodium(II)-catalysed C-H amination reactions developed by Du Bois to carry out simultaneous structure-activity relationship studies and arming (alkynylation) of natural products at 'unfunctionalized' positions. Allylic and benzylic C-H bonds in the natural products undergo amination while olefins undergo aziridination, and tertiary amine-containing natural products are converted to amidines by a C-H amination-oxidation sequence or to hydrazine sulfamate zwitterions by an unusual N-amination. The alkynylated derivatives are ready for conversion into cellular probes that can be used for mechanism-of-action studies. Chemo- and site-selectivity was studied with a diverse library of natural products. For one of these-the marine-derived anticancer diterpene, eupalmerin acetate-quantitative proteome profiling led to the identification of several protein targets in HL-60 cells, suggesting a polypharmacological mode of action.

Eugenol and isoeugenol, characteristic aromatic constituents of spices, are biosynthesized via reduction of a coniferyl alcohol ester

PubMed Central

Koeduka, Takao; Fridman, Eyal; Gang, David R.; Vassão, Daniel G.; Jackson, Brenda L.; Kish, Christine M.; Orlova, Irina; Spassova, Snejina M.; Lewis, Norman G.; Noel, Joseph P.; Baiga, Thomas J.; Dudareva, Natalia; Pichersky, Eran

2006-01-01

Phenylpropenes such as chavicol, t-anol, eugenol, and isoeugenol are produced by plants as defense compounds against animals and microorganisms and as floral attractants of pollinators. Moreover, humans have used phenylpropenes since antiquity for food preservation and flavoring and as medicinal agents. Previous research suggested that the phenylpropenes are synthesized in plants from substituted phenylpropenols, although the identity of the enzymes and the nature of the reaction mechanism involved in this transformation have remained obscure. We show here that glandular trichomes of sweet basil (Ocimum basilicum), which synthesize and accumulate phenylpropenes, possess an enzyme that can use coniferyl acetate and NADPH to form eugenol. Petunia (Petunia hybrida cv. Mitchell) flowers, which emit large amounts of isoeugenol, possess an enzyme homologous to the basil eugenol-forming enzyme that also uses coniferyl acetate and NADPH as substrates but catalyzes the formation of isoeugenol. The basil and petunia phenylpropene-forming enzymes belong to a structural family of NADPH-dependent reductases that also includes pinoresinol–lariciresinol reductase, isoflavone reductase, and phenylcoumaran benzylic ether reductase. PMID:16782809

Sustainable High Quality Recycling of Aggregates from Waste-to-Energy, Treated in a Wet Bottom Ash Processing Installation, for Use in Concrete Products

PubMed Central

Van den Heede, Philip; Ringoot, Niels; Beirnaert, Arno; Van Brecht, Andres; Van den Brande, Erwin; De Schutter, Geert; De Belie, Nele

2015-01-01

Nowadays, more efforts towards sustainability are required from the concrete industry. Replacing traditional aggregates by recycled bottom ash (BA) from municipal solid waste incineration can contribute to this goal. Until now, only partial replacement has been considered to keep the concrete workability, strength and durability under control. In this research, the feasibility of a full aggregate replacement was investigated for producing prefabricated Lego bricks. It was found that the required compressive strength class for this purpose (C20/25) could be achieved. Nevertheless, a thorough understanding of the BA properties is needed to overcome other issues. As BA is highly absorptive, the concrete’s water demand is high. This workability issue can be dealt with by subjecting the fine BA fraction to a crushing operation to eliminate the porous elements and by pre-wetting the fine and coarse BA fractions in a controlled manner. In addition, a reactive NaOH washing is needed to avoid formation of longitudinal voids and the resulting expansion due to the metallic aluminum present in the BA. Regarding the long-term behavior, heavy metal leaching and freeze-thaw exposure are not problematic, though there is susceptibility to acetic and lactic acid attack and maybe increased sensitivity to alkali-silica reaction. PMID:28787809

Sustainable High Quality Recycling of Aggregates from Waste-to-Energy, Treated in a Wet Bottom Ash Processing Installation, for Use in Concrete Products.

PubMed

Van den Heede, Philip; Ringoot, Niels; Beirnaert, Arno; Van Brecht, Andres; Van den Brande, Erwin; De Schutter, Geert; De Belie, Nele

2015-12-25

Nowadays, more efforts towards sustainability are required from the concrete industry. Replacing traditional aggregates by recycled bottom ash (BA) from municipal solid waste incineration can contribute to this goal. Until now, only partial replacement has been considered to keep the concrete workability, strength and durability under control. In this research, the feasibility of a full aggregate replacement was investigated for producing prefabricated Lego bricks. It was found that the required compressive strength class for this purpose (C20/25) could be achieved. Nevertheless, a thorough understanding of the BA properties is needed to overcome other issues. As BA is highly absorptive, the concrete's water demand is high. This workability issue can be dealt with by subjecting the fine BA fraction to a crushing operation to eliminate the porous elements and by pre-wetting the fine and coarse BA fractions in a controlled manner. In addition, a reactive NaOH washing is needed to avoid formation of longitudinal voids and the resulting expansion due to the metallic aluminum present in the BA. Regarding the long-term behavior, heavy metal leaching and freeze-thaw exposure are not problematic, though there is susceptibility to acetic and lactic acid attack and maybe increased sensitivity to alkali-silica reaction.

Cytokinin delays dark-induced senescence in rice by maintaining the chlorophyll cycle and photosynthetic complexes.

PubMed

Talla, Sai Krishna; Panigrahy, Madhusmita; Kappara, Saivishnupriya; Nirosha, P; Neelamraju, Sarla; Ramanan, Rajeshwari

2016-03-01

The phytohormone cytokinin (CK) is known to delay senescence in plants. We studied the effect of a CK analog, 6-benzyl adenine (BA), on rice leaves to understand the possible mechanism by which CK delays senescence in a drought- and heat-tolerant rice cultivar Nagina22 (N22) using dark-induced senescence (DIS) as a surrogate for natural senescence of leaves. Leaves of N22-H-dgl162, a stay-green mutant of N22, and BA-treated N22 showed retention of chlorophyll (Chl) pigments, maintenance of the Chl a/b ratio, and delay in reduction of both photochemical efficiency and rate of oxygen evolution during DIS. HPLC analysis showed accumulation of 7-hydroxymethyl chlorophyll (HmChl) during DIS, and the kinetics of its accumulation correlated with progression of senescence. Transcriptome analysis revealed that several plastid-localized genes, specifically those associated with photosystem II (PSII), showed higher transcript levels in BA-treated N22 and the stay-green mutant leaves compared with naturally senescing N22 leaves. Real-time PCR analyses showed that genes coding for enzymes associated with Chl a/b interconversion and proteins associated with light-harvesting complexes maintained higher transcript levels up to 72h of DIS following BA treatment. The pigment-protein complexes analyzed by green gel remained intact in both N22-H-dgl162 and BA-treated N22 leaves even after 96h of DIS. Thus, CK delays senescence by accumulation of HmChl and up-regulating genes in the Chl cycle, thereby maintaining the Chl a/b ratio. Also, CK treatment retains higher transcript levels of PSII-related genes, resulting in the stability of photosynthetic pigment complexes and functional stay-greenness in rice. © The Author 2016. Published by Oxford University Press on behalf of the Society for Experimental Biology.

Acceleration of adventitious shoots by interaction between exogenous hormone and adenine sulphate in Althaea officinalis L.

PubMed

Naz, Ruphi; Anis, M

2012-11-01

In the current study attempts were made to investigate the effects of three different phases of callus induction followed by adventitious regeneration from leaf segments (central and lateral vein). Callus induction was observed in Murashige and Skoog's (MS) medium supplemented with 15.0 μM 2,4-dichloro phenoxy acetic acid (2,4-D). Adventitious shoot buds formation was achieved on MS medium supplemented with 7.5 μM 2,4-D and 20.0 μM AdS in liquid medium as it induced 19.2 ± 0.58 buds in central vein explants. Addition of different growth regulators (cytokinins-6-benzyladenine, kinetin and 2-isopentenyl adenine alone or in combination with auxins-indole-3-acetic acid, indole-3-butyric acid and α-naphthalene acetic acid, improved the shoot regeneration efficiency, in which 5.0 μM 6-benzyl adenine along with 0.25 μM α-naphthalene acetic acid was shown to be the most effective medium for maximum shoot regeneration (81.3 %) with 24.6 number of shoots and 4.4 ± 0.08 cm shoot length per explant. Leaf culture of central veins led to better shoot formation capacity in comparison to lateral vein. Rooting was readily achieved on the differentiated shoots on 1/2 MS medium augmented with 20.0 μM indole-3-butyric acid. The plants were successfully hardened off in sterile soilrite followed by their establishment in garden soil with 80 % survival rate.

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...

Micropropagation of annatto (Bixa orellana L.) from mature tree and assessment of genetic fidelity of micropropagated plants with RAPD markers.

PubMed

Siril, E A; Joseph, Nisha

2013-01-01

An in vitro propagation technique based on axillary bud proliferation was developed for the first time to mature annatto (Bixa orellana L.) tree. Nodal segments cultured on Murashige and Skoog (MS) medium supplemented with 1.0 μM benzyl adenine (BA) and tender coconut water (10 %) showed significantly high (P < 0.05) explant response (67.0 %), development of elongated shoots (3.36), shoot buds (8.9) and shoot elongation (3.53 cm). Cytokinins like zeatin, isopentenyl adenine (2-iP), kinetin, or thidiazuron (TDZ) were inferior to BA to induce multiple shoots. Seasonal variations significantly affected the in vitro response of nodal explants. In vitro rooting experiments have showed 55.6 % rooting on MS medium containing 15 μM indole-3-butyric acid (IBA). Alternatively, in vitro raised shoots were rooted (61.1 %) ex vitro, by 10 mM indole-3-butyric acid (IBA) for 30 s. The results of the RAPD marker system revealed the genetic stability among the micropropagated plants. The present protocol in brief, can be used for the clonal propagation of the superior genotype and preservation of germplasm.

Silencing Nicotiana attenuata LHY and ZTL alters circadian rhythms in flowers

PubMed Central

Yon, Felipe; Joo, Youngsung; Cortés Llorca, Lucas; Rothe, Eva; Baldwin, Ian T.; Kim, Sang-Gyu

2016-01-01

Summary The rhythmic opening/closing and volatile emissions of flowers is known to attract pollinators at specific times. That these rhythms are maintained under constant light or dark conditions suggests a circadian clock involvement. Although a forward and reverse genetic approach led to the identification of core circadian clock components in Arabidopsis thaliana, involvement of these clock components for floral rhythms remained untested likely due to weak diurnal rhythms in A. thaliana flowers.Here we addressed the role of these core clock components in the flowers of the wild tobacco Nicotiana attenuata, whose flowers open at night, emit benzyl acetone (BA) scents, and move vertically through a 140° arc.We first measured N. attenuata floral rhythms under constant light conditions. The results suggest that the circadian clock controls flower opening, BA emission, and pedicel movement, but not flower closing.We generated transgenic N. attenuata lines silenced in the homologous genes of Arabidopsis LATE ELONGATED HYPOCOTYL (LHY) and ZEITLUPE (ZTL), which are known as a core clock component. Silencing NaLHY and NaZTL strongly altered floral rhythms in different ways, indicating that conserved clock components in N. attenuata coordinate these floral rhythms. PMID:26439540

Microclonal Multipication of Wild Cherry (Prunus Avium L.) from Shoot Tips and Root Sucker Buds

Treesearch

Branka Pevalek-Kozlina; Charles H. Michler; Sibila Jelaska

1994-01-01

The effects of different combinations and concentrations of the growth regulators: 6-benzylaminopurine (BA), 6 furfurylaminopurine (KIN), N6- (2-isopentenyl) adenine (2iP), indole-3-butyric acid (IBA), indole-3-acetic acid (IAA) and a-naphthaleneacetic acid (NAA) on axillary shoot multiplication rates for wild cherry (Prunus aviurn...

Gas-liquid chromatographic determination of resmethrin in corn, cornmeal, flour, and wheat.

PubMed

Simonaitis, R A; Cail, R S

1975-09-01

A gas-liquid chromatographic (GLC) method was developed for the determination of residues of resmethrin ((5-benzyl-3-furyl)methyl cis-trans-(+/-)-2,2-dimethyl-3-(2-methylpropenyl)-cyclopropanecarboxylate) in corn, cornmeal, flour, and wheat. The commodity, fortified with resmethrin, was extracted by tumbling with pentane and transferred to acetonitrile, the fat was partitioned off, and the sample was chromatographed with 3% ethyl acetate in pentane on Florisil containing 0.5% water. The resmethrin residue was determined by GLC with a flame ionization detector. The results were compared with known standards that had undergone the same cleanup procedures. The method was sensitive to concentrations of resmethrin to 0.2 ppm, recoveries averaged 83%, and reproducibility was good.

Factors Affecting the Accumulation of Curcumin in Microrhizomes of Curcuma aromatica Salisb

PubMed Central

Zhang, Xiaoxia; Sun, Shulan; Wang, Xiaojing

2015-01-01

Curcuminoids, and mainly curcumin, are potential therapeutic agents for the prevention of various diseases; however, little is known about the factors that influence their accumulation in Curcuma species. In this study, the effects of factors such as sucrose concentration, different ratios of 6-benzylaminopurine (6-BA) and α-naphthalene acetic acid (NAA), and light quality on the accumulation of curcumin and other curcuminoids in Curcuma aromatica were investigated. Microrhizomes grown on media containing 3% sucrose produced more curcumin and other curcuminoids than those grown on higher concentrations. Moreover, when compared to other ratios of 6-BA and NAA, microrhizomes induced on 3% sucrose media supplemented with 3.0 mg/L 6-BA and 0.5 mg/L NAA produced more curcumin and other curcuminoids; however, the amount was less than in microrhizomes grown on 3% sucrose alone. We determined that a 5% sucrose medium supplemented with 3.0 mg/L of 6-BA and 0.5 mg/L of NAA enhanced the levels of curcumin and curcuminoids and that exposure to red light further increased production. PMID:25722985

Factors affecting the accumulation of curcumin in microrhizomes of Curcuma aromatica Salisb.

PubMed

Wu, Ke; Zhang, Xiaoxia; Sun, Shulan; Wang, Xiaojing

2015-01-01

Curcuminoids, and mainly curcumin, are potential therapeutic agents for the prevention of various diseases; however, little is known about the factors that influence their accumulation in Curcuma species. In this study, the effects of factors such as sucrose concentration, different ratios of 6-benzylaminopurine (6-BA) and α-naphthalene acetic acid (NAA), and light quality on the accumulation of curcumin and other curcuminoids in Curcuma aromatica were investigated. Microrhizomes grown on media containing 3% sucrose produced more curcumin and other curcuminoids than those grown on higher concentrations. Moreover, when compared to other ratios of 6-BA and NAA, microrhizomes induced on 3% sucrose media supplemented with 3.0 mg/L 6-BA and 0.5 mg/L NAA produced more curcumin and other curcuminoids; however, the amount was less than in microrhizomes grown on 3% sucrose alone. We determined that a 5% sucrose medium supplemented with 3.0 mg/L of 6-BA and 0.5 mg/L of NAA enhanced the levels of curcumin and curcuminoids and that exposure to red light further increased production.

Synthesis of Y1Ba2Cu3O(sub x) superconducting powders by intermediate phase reaction

NASA Technical Reports Server (NTRS)

Moore, C.; Fernandez, J. F.; Recio, P.; Duran, P.

1990-01-01

One of the more striking problems for the synthesis of the Y1Ba2Cu3Ox compound is the high-temperature decomposition of the BaCO3. This compound is present as raw material or as an intermediate compound in chemical processes such as amorphous citrate, coprecipitation oxalate, sol-gel process, acetate pyrolisis, etc. This fact makes difficult the total formation reaction of the Y1Ba2Cu3Ox phase and leads to the presence of undesirable phases such as the BaCuO2 phase, the 'green phase', Y2BaCuO5 and others. Here, a new procedure to overcome this difficulty is studied. The barium cation is previously combined with yttrium and/or copper to form intermediate compounds which can react between them to give Y1Ba2Cu3Ox. BaY2O4 and BaCu2O3 react according to the equation BaY2O4+3BaCu2O3 yields 2Y1Ba2Cu3Ox. BaY2O4 is a stable compound of the Y2O3-BaO system; BaCu2O3 is an intimate mixture of BaCuO2 and uncombined CuO. The reaction kinetics of these phases have been established between 860 and 920 C. The phase evolution has been determined. The crystal structure of the Y1Ba2Cu3Ox obtained powder was studied. According to the results obtained from the kinetics study the Y1Ba2Cu3Ox the synthesis was performed at temperatures of 910 to 920 C for short treatment times (1 to 2 hours). Pure Y1Ba2Cu3Ox was prepared, which develops orthorombic type I structure despite of the cooling cycle. Superconducting transition took place at 91 K. The sintering behavior and the superconducting properties of sintered samples were studied. Density, microstructure and electrical conductivity were measured. Sintering densities higher than 95 percent D(sub th) were attained at temperatures below 940 C. Relatively fine grained microstructure was observed, and little or no-liquid phase was detected.

Biosorption behavior and mechanism of lead (II) from aqueous solution by aerobic granules (AG) and bacterial alginate (BA)

NASA Astrophysics Data System (ADS)

Wang, Lin; Li, Yu

2012-12-01

Lead (Pb) and its compounds are common pollutants in industrial wastewaters. To develop appropriate Pb2+ treatment technologies, aerobic granules (AG) and bacterial alginates (BA) were studied as alternative biosorbents to remove Pb2+ from aqueous solutions. The biosorption mechanism of AG and BA were further analyzed to determine which functional groups in AG and BA are active in Pb2+ biosorption. In this paper, the Pb2+ biosorption behavior of AG and BA was respectively investigated in batch experiments from the perspectives of the initial pH, contact time, and initial Pb2+ concentration. The results showed that biosorption of Pb2+ by AG and BA occurred within 60min at the initial Pb2+ concentrations (0-150 mg L-1). The actual saturated Pb2+ biosorption capability of AG was 101.97 mg g-1 (dry weight of aerobic granular biomass). When the initial pH was 5, the biosorption capability of AG and BA was highest at the initial Pb2+ concentrations (0-20mg L-1). During the process of Pb2+ biosorption, K+, Ca2+, and Mg2+ were released. The Ion Chromatography (IC) and Fourier Transform Infrared Spectroscopy (FTIR) further highlighted the main role of ion exchange between Ca2+ and Pb2+ and sequestration of Pb2+ with carboxyl (-COO-) of AG and BA. This analogical analysis verifies that BA is responsible for biosorption of Pb2+ by AG. At the same optimal pH, AG cultivated with different carbon source has different Pb2+ biosorption capacity. The Pb2+ biosorption by AG with sodium acetate as the sole carbon source is higher than AG with glucose as carbon source.

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

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.

Development of supercritical CO2 extraction of bioactive phytochemicals from black poplar (Populus nigra L.) buds followed by GC-MS and UHPLC-DAD-QqTOF-MS.

PubMed

Kuś, Piotr M; Okińczyc, Piotr; Jakovljević, Martina; Jokić, Stela; Jerković, Igor

2018-05-25

The supercritical CO 2 (SC-CO 2 ) extraction process of black poplar (Populus nigra L.) buds was optimized (pressure, temperature) based on the yields of major phytochemicals (volatiles and non-volatiles). The optimal settings were 30 MPa/60 °C. Major volatiles determined by GC-MS in the optimized SC-CO 2 extract (mg of benzyl salicylate equivalent (BSE) per 100 g of buds) were: pinostrobin chalcone (1574.2), β-eudesmol (640.8), α-eudesmol (581.9), 2-methyl-2-butenyl-p-coumarate (289.9), pentyl-p-coumarate (457.0), γ-eudesmol (294.4), and benzyl salicylate (289.2). Partial qualitative similarity was observed between SC-CO 2 extracts and corresponding hydrodistilled essential oil dominated by sesquiterpenes, but with lower yields. Major compounds (mg per 100 g of buds) identified by UHPLC-DAD-QqTOF-MS in the optimized SC-CO 2 extract were: pinostrobin (751.7), pinocembrin (485.6), 3-O-pinobanksin acetate and methyl-butenyl-p-coumarate (290.2; 144.9 of pinobanksin and p-coumaric acid equivalents, respectively). SC-CO 2 extraction was found useful for green, efficient and simultaneous extraction of both volatile/non-volatile, bioactive phytochemicals of poplar buds - precursors of poplar-type propolis. Copyright © 2018 Elsevier B.V. All rights reserved.

An antitumor promoter from Moringa oleifera Lam.

PubMed

Guevara, A P; Vargas, C; Sakurai, H; Fujiwara, Y; Hashimoto, K; Maoka, T; Kozuka, M; Ito, Y; Tokuda, H; Nishino, H

1999-04-06

In the course of studies on the isolation of bioactive compounds from Philippine plants, the seeds of Moringa oleifera Lam. were examined and from the ethanol extract were isolated the new O-ethyl-4-(alpha-L-rhamnosyloxy)benzyl carbamate (1) together with seven known compounds, 4(alpha-L-rhamnosyloxy)-benzyl isothiocyanate (2), niazimicin (3), niazirin (4), beta-sitosterol (5), glycerol-1-(9-octadecanoate) (6), 3-O-(6'-O-oleoyl-beta-D-glucopyranosyl)-beta-sitosterol (7), and beta-sitosterol-3-O-beta-D-glucopyranoside (8). Four of the isolates (2, 3, 7, and 8), which were obtained in relatively good yields, were tested for their potential antitumor promoting activity using an in vitro assay which tested their inhibitory effects on Epstein-Barr virus-early antigen (EBV-EA) activation in Raji cells induced by the tumor promoter, 12-O-tetradecanoyl-phorbol-13-acetate (TPA). All the tested compounds showed inhibitory activity against EBV-EA activation, with compounds 2, 3 and 8 having shown very significant activities. Based on the in vitro results, niazimicin (3) was further subjected to in vivo test and found to have potent antitumor promoting activity in the two-stage carcinogenesis in mouse skin using 7,12-dimethylbenz(a)anthracene (DMBA) as initiator and TPA as tumor promoter. From these results, niazimicin (3) is proposed to be a potent chemo-preventive agent in chemical carcinogenesis. Copyright 1999 Elsevier Science B.V.

21 CFR 172.515 - Synthetic flavoring substances and adjuvants.

Code of Federal Regulations, 2014 CFR

2014-04-01

...-hydroxyundecanoic acid γ-lactone; peach aldehyde; aldehyde C-14. Undecenal. 2-Undecanone; methyl nonyl ketone. 9.... Acetophenone; methyl phenyl ketone. Allyl anthranilate. Allyl butyrate. Allyl cinnamate. Allyl...-heptanone; benzyl dipropyl ketone. Benzyl isobutyrate. Benzyl isovalerate. Benzyl mercaptan; α-toluenethiol...

Establishment of an efficient in vitro regeneration protocol for rapid and mass propagation of Dendrobium chrysotoxum Lindl. using seed culture.

PubMed

Nongdam, Potshangbam; Tikendra, Leimapokpam

2014-01-01

An efficient in vitro regeneration protocol from seed culture has been established successfully for Dendrobium chrysotoxum, an epiphytic orchid having tremendous ornamental and medicinal values. Seed germination response was encouraging in Mitra (M) medium enriched with different combinations of auxins and cytokinins. Medium supplemented with 0.4% activated charcoal (AC), 2 mg/L 6-benzyl amino purine (BAP), and 2 mg/L indole-3-acetic acid (IAA) produced best seed germination percentage in 2 weeks of culture. Incorporation of higher concentration of kinetin (KN) or BAP in combination with low auxin in medium induced pronounced shooting and leaf formation. Reduction in leaf development was evident when cytokinins exist singly in medium indicating synergistic effect of auxin and cytokinin in leaf induction. Presence of elevated level of indole-3-butyric acid (IBA) or 1-naphthalene acetic acid (NAA) with low cytokinin content in medium generated more in vitro rooting, though IBA was found to be more effective in rooting induction as compared to NAA. The in vitro protocol for asymbiotic seed germination developed from the present investigation can be used for rapid mass propagation of this highly important Dendrobium orchid species.

Establishment of an Efficient In Vitro Regeneration Protocol for Rapid and Mass Propagation of Dendrobium chrysotoxum Lindl. Using Seed Culture

PubMed Central

2014-01-01

An efficient in vitro regeneration protocol from seed culture has been established successfully for Dendrobium chrysotoxum, an epiphytic orchid having tremendous ornamental and medicinal values. Seed germination response was encouraging in Mitra (M) medium enriched with different combinations of auxins and cytokinins. Medium supplemented with 0.4% activated charcoal (AC), 2 mg/L 6-benzyl amino purine (BAP), and 2 mg/L indole-3-acetic acid (IAA) produced best seed germination percentage in 2 weeks of culture. Incorporation of higher concentration of kinetin (KN) or BAP in combination with low auxin in medium induced pronounced shooting and leaf formation. Reduction in leaf development was evident when cytokinins exist singly in medium indicating synergistic effect of auxin and cytokinin in leaf induction. Presence of elevated level of indole-3-butyric acid (IBA) or 1-naphthalene acetic acid (NAA) with low cytokinin content in medium generated more in vitro rooting, though IBA was found to be more effective in rooting induction as compared to NAA. The in vitro protocol for asymbiotic seed germination developed from the present investigation can be used for rapid mass propagation of this highly important Dendrobium orchid species. PMID:25401154

Synthesis and characterization of the tetranuclear iron(III) complex of a new asymmetric multidentate ligand. A structural model for purple acid phosphatases.

PubMed

Boudalis, Athanassios K; Aston, Robyn E; Smith, Sarah J; Mirams, Ruth E; Riley, Mark J; Schenk, Gerhard; Blackman, Allan G; Hanton, Lyall R; Gahan, Lawrence R

2007-11-28

The ligand, 2-((2-hydroxy-5-methyl-3-((pyridin-2-ylmethylamino)methyl)benzyl)(2-hydroxybenzyl)amino)acetic acid (H(3)HPBA), which contains a donor atom set that mimics that of the active site of purple acid phosphatase is described. Reaction of H(3)HPBA with iron(III) or iron(II) salts results in formation of the tetranuclear complex, [Fe(4)(HPBA)(2)(OAc)(2)(mu-O)(mu-OH)(OH(2))(2)]ClO(4) x 5H(2)O. X-Ray structural analysis reveals the cation consists of four iron(III) ions, two HPBA(3-) ligands, two bridging acetate ligands, a bridging oxide ion and a bridging hydroxide ion. Each binucleating HPBA(3-) ligand coordinates two structurally distinct hexacoordinate iron(III) ions. The two metal ions coordinated to a HPBA(3-) ligand are linked to the two iron(III) metal ions of a second, similar binuclear unit by intramolecular oxide and hydroxide bridging moieties to form a tetramer. The complex has been further characterised by elemental analysis, mass spectrometry, UV-vis and MCD spectroscopy, X-ray crystallography, magnetic susceptibility measurements and variable-temperature Mössbauer spectroscopy.

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.

Selective retardation of perfume oil evaporation from oil-in-water emulsions stabilized by either surfactant or nanoparticles.

PubMed

Binks, Bernard P; Fletcher, Paul D I; Holt, Benjamin L; Beaussoubre, Pascal; Wong, Kenneth

2010-12-07

We have used dynamic headspace analysis to investigate the evaporation rates of perfume oils from stirred oil-in-water emulsions into a flowing gas stream. We compare the behavior of an oil of low water solubility (limonene) and one of high water solubility (benzyl acetate). It is shown how the evaporation of an oil of low water solubility is selectively retarded and how the retardation effect depends on the oil volume fraction in the emulsion. We compare how the evaporation retardation depends on the nature of the adsorbed film stabilizing the emulsion. Surfactant films are less effective than adsorbed films of nanoparticles, and the retardation can be further enhanced by compression of the adsorbed nanoparticle films by preshrinking the emulsion drops.

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.

Fabrication and electrochemical performance of a stable, anode supported thin BaCe0.4Zr0.4Y0.2O3-δ electrolyte Protonic Ceramic Fuel Cell

NASA Astrophysics Data System (ADS)

Nasani, Narendar; Ramasamy, Devaraj; Mikhalev, Sergey; Kovalevsky, Andrei V.; Fagg, Duncan P.

2015-03-01

The present work deals with the fabrication and electrochemical characterisation of a potential protonic ceramic fuel cell based on a Ni-BaZr0.85Y0.15O3-δ anode supported thin film proton conducting BaCe0.4Zr0.4Y0.2O3-δ electrolyte with a Pr2NiO4+δ cathode. Anode and electrolyte materials were prepared by an acetate-H2O2 combustion method. A thin (∼5 μm), dense and crack free BaCe0.4Zr0.4Y0.2O3-δ electrolyte film was successfully obtained on a porous anode support by spin coating and firing at 1450 °C. Maximum power densities of 234, 158, 102 and 63 mW cm-2 at 700, 650, 600 and 550 °C, respectively were achieved for the Ni-BaZr0.85Y0.15O3-δ/BaCe0.4Zr0.4Y0.2O3-δ/Pr2NiO4+δ single cell under fuel cell testing conditions. Electrode polarisation resistance was assessed at open circuit conditions by use of electrochemical impedance spectroscopy (EIS) and is shown to dominate the area specific resistance at low temperatures. Postmortem analysis by scanning electron microscopy (SEM), reveals that no delamination occurs at anode/electrolyte or electrolyte/cathode interfaces upon cell operation.

Mechanochemical synthesis of MgF2 - MF2 composite systems (M = Ca, Sr, Ba)

NASA Astrophysics Data System (ADS)

Scholz, G.; Breitfeld, S.; Krahl, T.; Düvel, A.; Heitjans, P.; Kemnitz, E.

2015-12-01

The capability of mechanochemical synthesis for the formation of MgF2-MF2 (M: Ca, Sr, Ba) composites, solid solutions or well-defined compounds was tested applying a fluorination of different fluorine-free metal sources with NH4F directly at milling. No evidence was found for a substitution of Mg2+ with Ca2+ (Sr2+, Ba2+) ions, or vice versa, in rutile or fluorite structure. However, an equimolar ratio of Mg2+ to the second cation allows the mechanochemical synthesis of tetrafluoromagnesates, MMgF4, which is more and more hampered the smaller the radius of the cation M2+ is. BaMgF4 is formed even phase pure from the acetates, SrMgF4 can only be observed in a mixture accompanied by the binary fluorides. In addition, 19F MAS NMR spectra along with calculations of 19F isotropic chemical shift values according to the superposition model point to the formation of a metastable phase of CaMgF4, which disappears at thermal treatment and decomposes into the binary fluorides CaF2 and MgF2.

Multiscale and Multifunctional Emulsions by Host–Guest Interaction-Mediated Self-Assembly

PubMed Central

2018-01-01

Emulsions are widely used in numerous fields. Therefore, there has been increasing interest in the development of new emulsification strategies toward emulsions with advanced functions. Herein we report the formation of diverse emulsions by host–guest interaction-mediated interfacial self-assembly under mild conditions. In this strategy, a hydrophilic diblock copolymer with one block containing β-cyclodextrin (β-CD) can assemble at the oil/water interface when its aqueous solution is mixed with an oil phase of benzyl alcohol (BA), by host–guest interactions between β-CD and BA. This results in significantly reduced interfacial tension and the formation of switchable emulsions with easily tunable droplet sizes. Furthermore, nanoemulsions with excellent stability are successfully prepared simply via vortexing. The self-assembled oil-in-water emulsions also show catastrophic phase inversion, which can generate stable bicontinuous phase and water-in-oil emulsions, thereby further extending phase structures that can be realized by this host–guest self-assembly approach. Moreover, the host–guest nanoemulsions are able to engineer different nanoparticles and microstructures as well as solubilize a diverse array of hydrophobic drugs and dramatically enhance their oral bioavailability. The host–guest self-assembly emulsification is facile, energetically friendly, and fully translatable to industry, therefore representing a conceptually creative approach toward advanced emulsions. PMID:29806006

Silencing Nicotiana attenuata LHY and ZTL alters circadian rhythms in flowers.

PubMed

Yon, Felipe; Joo, Youngsung; Cortés Llorca, Lucas; Rothe, Eva; Baldwin, Ian T; Kim, Sang-Gyu

2016-02-01

The rhythmic opening/closing and volatile emissions of flowers are known to attract pollinators at specific times. That these rhythms are maintained under constant light or dark conditions suggests a circadian clock involvement. Although a forward and reverse genetic approach has led to the identification of core circadian clock components in Arabidopsis thaliana, the involvement of these clock components in floral rhythms has remained untested, probably because of the weak diurnal rhythms in A. thaliana flowers. Here, we addressed the role of these core clock components in the flowers of the wild tobacco Nicotiana attenuata, whose flowers open at night, emit benzyl acetone (BA) scents and move vertically through a 140° arc. We first measured N. attenuata floral rhythms under constant light conditions. The results suggest that the circadian clock controls flower opening, BA emission and pedicel movement, but not flower closing. We generated transgenic N. attenuata lines silenced in the homologous genes of Arabidopsis LATE ELONGATED HYPOCOTYL (LHY) and ZEITLUPE (ZTL), which are known to be core clock components. Silencing NaLHY and NaZTL strongly altered floral rhythms in different ways, indicating that conserved clock components in N. attenuata coordinate these floral rhythms. © 2015 The Authors. New Phytologist © 2015 New Phytologist Trust.

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.

Benzo[a]pyrene bioavailability from pristine soil and contaminated sediment assessed using two in vitro models.

PubMed

Vasiluk, Luba; Pinto, Linda J; Walji, Zahra A; Tsang, Wing Shan; Gobas, Frank A P C; Eickhoff, Curtis; Moore, Margo M

2007-03-01

A major route of exposure to hydrophobic organic contaminants (HOCs), such as benzo[a]pyrene (BaP), is ingestion. Matrix-bound HOCs may become bioavailable after mobilization by the gastrointestinal fluids followed by sorption to the intestinal epithelium. The purpose of this research was to measure the bioavailability of [14C]-BaP bound to pristine soils or field-contaminated sediment using an in vitro model of gastrointestinal digestion followed by sorption to human enterocytes (Caco-2 cells) or to a surrogate membrane, ethylene vinyl acetate (EVA) thin film. Although Caco-2 cells had a twofold higher lipid-normalized fugacity capacity than EVA, [14C]-BaP uptake by Caco-2 lipids and EVA thin film demonstrated a linear relationship within the range of BaP concentrations tested. These results suggest that EVA thin film is a good membrane surrogate for passive uptake of BaP. The in vitro system provided enough sensitivity to detect matrix effects on bioavailability; after 5 h, significantly lower concentrations of [14C]-BaP were sorbed into Caco-2 cells from soil containing a higher percentage of organic matter compared to soil with a lower percentage of organic matter. The [14C]-BaP desorption rate from Caco-2 lipids consistently was twofold higher than from EVA thin film for all matrices tested. The more rapid kinetics observed with Caco-2 cells probably were due to the greater surface area available for absorption/desorption in the cells. After 5 h, the uptake of BaP into Caco-2 lipid was similar in live and metabolically inert Caco-2 cells, suggesting that the primary route of BaP uptake is by passive diffusion. Moreover, the driving force for uptake is the fugacity gradient that exists between the gastrointestinal fluid and the membrane.

Uptake, Distribution, and Metabolism of 1-Naphthaleneacetic Acid and Indole-3-Acetic Acid During Callus Initiation From Actinidia deliciosa Tissues.

PubMed

Centeno; Fernández; Feito; Rodríguez

1999-10-01

1-Naphthaleneacetic acid (NAA) and 6-benzyladenine (BA) were required for in vitro callus formation at the basal edge of kiwifruit (Actinidia deliciosa [A. Chev] Liang and Ferguson, cv. Hayward) petioles. The uptake, metabolism, and concentration of NAA and indole-3-acetic acid (IAA) content were examined in the explants during the callus initiation period. After 1, 6, 12, 24, 48, and 96 h of culture in the presence of [H(3)]NAA, petioles were divided into apical, middle, and basal portions and analyzed. Except for a high IAA level measured at 12 h, IAA content decreased in tissues during a culture period of 96 h. NAA uptake was higher in petiolar edges than in the middle portion, and NAA was rapidly conjugated with sugars and aspartic acid inside the tissues. The amide conjugation was triggered in apical and basal portions from 12 h and in the middle part from 48 h, with alpha-naphthylacetylaspartic acid being the major metabolite. Free-NAA concentration in cultured petioles achieved an equilibrium with the exogenously applied NAA (0.27 µm) from 12 h, and it remained constant thereafter. The relationships between the role attributed to NAA and BA in the initiation and the maintenance of disorganized growth of callus in kiwifruit cultures are discussed.

Solution spinning of a high-? oxide superconductor: the effect of poly(vinyl alcohol) spinning medium on the critical current density of melt-processed ? superconducting filaments

NASA Astrophysics Data System (ADS)

Tomita, Hisayo; Sunohara, Makoto; Goto, Tomoko; Takahashi, Kiyohisa

1996-12-01

The precursor 0953-2048/9/12/014/img9 filament was prepared by solution spinning through a homogeneous aqueous poly(vinyl alcohol) (PVA) solution of Y, Ba and Cu acetates. The solution spinning was successfully performed using PVA with degrees of polymerization (DP) of 1700 and 2450 and a degree of saponification of 85 mol%. The as-drawn filament was heated to remove volatile components and partially melted to generate a superconducting phase. The effects of the DP of PVA and a content of mixed acetates in the precursor filament on the critical current density 0953-2048/9/12/014/img10 of the melt-processed filament were examined. The higher 0953-2048/9/12/014/img11 was obtained for the filament spun from PVA solution of higher DP and lower acetate content. The highest 0953-2048/9/12/014/img11 value of 0953-2048/9/12/014/img13 at 77 K and 0 T was achieved for the filament spun from the DP 2450 PVA with an acetate to PVA ratio of two.

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.

Metabolic engineering of Clostridium acetobutylicum for butyric acid production with high butyric acid selectivity.

PubMed

Jang, Yu-Sin; Im, Jung Ae; Choi, So Young; Lee, Jung Im; Lee, Sang Yup

2014-05-01

A typical characteristic of the butyric acid-producing Clostridium is coproduction of both butyric and acetic acids. Increasing the butyric acid selectivity important for economical butyric acid production has been rather difficult in clostridia due to their complex metabolic pathways. In this work, Clostridium acetobutylicum was metabolically engineered for highly selective butyric acid production. For this purpose, the second butyrate kinase of C. acetobutylicum encoded by the bukII gene instead of butyrate kinase I encoded by the buk gene was employed. Furthermore, metabolic pathways were engineered to further enhance the NADH-driving force. Batch fermentation of the metabolically engineered C. acetobutylicum strain HCBEKW (pta(-), buk(-), ctfB(-) and adhE1(-)) at pH 6.0 resulted in the production of 32.5g/L of butyric acid with a butyric-to-acetic acid ratio (BA/AA ratio) of 31.3g/g from 83.3g/L of glucose. By further knocking out the hydA gene (encoding hydrogenase) in the HCBEKW strain, the butyric acid titer was not further improved in batch fermentation. However, the BA/AA ratio (28.5g/g) obtained with the HYCBEKW strain (pta(-), buk(-), ctfB(-), adhE1(-) and hydA(-)) was 1.6 times higher than that (18.2g/g) obtained with the HCBEKW strain at pH 5.0, while no improvement was observed at pH 6.0. These results suggested that the buk gene knockout was essential to get a high butyric acid selectivity to acetic acid in C. acetobutylicum. Copyright © 2014 International Metabolic Engineering Society. Published by Elsevier Inc. All rights reserved.

[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.

Responses of the L51781Y tk/sup +//tk/sup -/ mouse lymphoma cell forward mutation assay: III. 72 coded chemicals

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

McGregor, D.B.; Brown, A.; Cattanach, P.

Seventy-two chemicals were tested for their mutagenic potential in the L51781Y tk/sup +///sup -/ mouse lymphoma cell forward mutation assay, using procedures based upon those described previously. Cultures were exposed to the chemicals for 4 hr, then cultured for 2 days before planting in soft agar with or without trifluorothymidine (TFT), 3 ..mu..g/ml. The chemicals were tested at least twice. Significant responses were obtained with allyl isothiocyanate, p-benzoquinone dioxime, benzyl acetate, 2-biphenylamine HCl, bis(2-chloro-1-methylethyl)ether, cadmium chloride, chlordane, chlorobenzene, chlorobenzilate, 2-chloroethanol, chlorothalonil, cytarabine x HCl, p,p'-DDE, diazinon, 2,6-dichloro-p-phenylenediamine, N,N-diethylthiourea, diglycidylresorcinol ether, 2,4-dimethoxy aniline x HCl, disperse yellow 3, endosulfan, 1,2-epoxyhexadecane, ethylmore » acrylate, ethyl benzene, ethylene thiourea, F D and C yellow Number 6, furan, heptachlor, isophorone, mercuric chloride, 4,4'-methylenedianiline x 2 HCl, methyl viologen, nickel sulfate x 6H/sub 2/O, 4,4'-oxydianiline, pentachloroethane, piperonyl butoxide, propyl gallate, quinoline, rotenone, 2,4,5,6-tetrachloro-4-nitro-anisole, 1,1,1,2-tetrachloroethane, trichlorfon, 2,4,6-trichlorophenol, 2,4,5-trimethoxybenzaldehyde, 1,1,3-trimethyl-2-thiourea, 1-vinyl-3-cyclopetene dioxide, vinyl toluene, and ziram. The assay was incapable of providing a clear indication of whether some chemicals were mutagens; these benzyl alcohol, 1,4-dichlorobenzene, phenol, succinic acid-2,2-dimethyl hydrazide, and toluene.« less

Aroma profiles and preferences of Jasminum sambac L. flowers grown in Thailand.

PubMed

Kanlayavattanakul, Mayuree; Kitsiripaisarn, Sarun; Lourith, Nattaya

2013-01-01

Comparison of volatile constituents and odor preference of Jasminum sambac cultivated in Thailand was performed by enfleurage and solvent extractions. Enfleurage bases consisting of spermaceti wax, olive, sunflower, and rice bran oils were prepared. The defleurage flower was daily replaced with fresh jasmine for a period of 12 days. The absolute de pomades and extraits of each base were subjected to gas chromatography mass spectrometry (GC/MS) analysis, comparing with the concrete and absolute values obtained from maceration of jasmine in n-hexane for 24 h. Linalool, benzyl acetate, and α-farnesene were found as the main volatile compounds in the jasmine extracts. Spermaceti wax and olive oil gave the best quality base, exhibiting the most preferred resemblance of jasmine odor with the least difference from fresh jasmine, as evaluated by 103 Thai volunteers.

Effect of Subcritical Fluid Extraction on the High Quality of Headspace Oil from Jasminum sambac (L.) Aiton.

PubMed

Ye, Qiuping; Jin, Xinyi; Wei, Shiqin; Zheng, Gongyu; Li, Xinlei

2016-05-01

Subcritical fluid extraction (SFE), as a novel method, was applied to investigate the yield, quality, and sensory evaluation of headspace oil from Jasminum sambac (L.) Aiton in comparison with petroleum ether extraction (PEE). The results indicated that the yield of the headspace oil using SFE was significantly higher (P < 0.05) than when using PEE. SFE contributed to obtaining alcohols and ethers, prevented the thermal reaction of terpenes, and reduced α-caryophyllene and β-caryophyllene in the headspace oil. The contents of linalool (21.90%) and benzyl acetate (16.31%) were higher via SFE than PEE. In addition, the sensory evaluation of SFE was superior to PEE, indicating a fresh, jasmine-like odor and green-yellow color. Thus, SFE is an improved method for obtaining natural headspace oil from jasmine flowers.

Characterization, Degradation, and Reaction Pathways of Indoor Toluene over Visible-light-driven S, Zn Co-doped TiO2

NASA Astrophysics Data System (ADS)

Chu, H.; Lin, Y. H.; Lin, C. Y.

2017-01-01

Sulfur and Zinc co-doped TiO2 prepared by a sol-gel method to degrade toluene under a fluorescent lamp was investigated. The results indicate that S,Zn co-doped TiO2 photocatalysts are mainly nano-size with an anatase phase structure. The degradation reactions of toluene were performed under various operation conditions. The results show that the toluene conversion increases with increasing toluene concentration and decreasing relative humidity. Based on the results of activity test, S0.05Zn0.001/TiO2 was chosen for further studies. The main oxidation products of toluene photodegradation are CO2, H2O, benzyl alcohol, acetone, butadiene and acetic acid. Two possible mechanisms have been developed for photodegradation of toluene in a dry and a humid environment.

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

High rate capability of a BaTiO3-decorated LiCoO2 cathode prepared via metal organic decomposition

NASA Astrophysics Data System (ADS)

Teranishi, Takashi; Katsuji, Naoto; Yoshikawa, Yumi; Yoneda, Mika; Hayashi, Hidetaka; Kishimoto, Akira; Yoda, Koji; Motobayashi, Hidefumi; Tasaki, Yuzo

2016-10-01

Metal organic decomposition (MOD) using octylic acid salts was applied to synthesize a BaTiO3-LiCoO2 (BT-LC) composite powder. The Ba and Ti octylates were utilized as metal precursors, in an attempt to synthesize homogeneous BT nanoparticles on the LC matrix. The BT-LC composite, having a phase-separated composite structure without any impurity phase, was successfully obtained by optimizing the MOD procedure. The composite prepared using octylate precursors exhibited a sharper distribution and better dispersibility of decorated BT particles. Additionally, the average particle size of the decorated BTs using metal octylate was reduced to 23.3 nm, compared to 44.4 nm from conventional processes using Ba acetate as well as Ti alkoxide as precursors. The composite cathode displayed better cell performance than its conventional counterpart; the discharge capacity of the metal octylate-derived specimen was 55.6 mAh/g at a 50C rate, corresponding to 173% of the capacity of the conventional specimen (32.2 mAh/g). The notable improvement in high rate capability obtained in this study, compared with the conventional route, was attributed to the higher density of the triple junction formed by the BT-LC-electrolyte interface.

Arabidopsis thaliana GH3.5 acyl acid amido synthetase mediates metabolic crosstalk in auxin and salicylic acid homeostasis

PubMed Central

Westfall, Corey S.; Sherp, Ashley M.; Zubieta, Chloe; Alvarez, Sophie; Schraft, Evelyn; Marcellin, Romain; Ramirez, Loren; Jez, Joseph M.

2016-01-01

In Arabidopsis thaliana, the acyl acid amido synthetase Gretchen Hagen 3.5 (AtGH3.5) conjugates both indole-3-acetic acid (IAA) and salicylic acid (SA) to modulate auxin and pathogen response pathways. To understand the molecular basis for the activity of AtGH3.5, we determined the X-ray crystal structure of the enzyme in complex with IAA and AMP. Biochemical analysis demonstrates that the substrate preference of AtGH3.5 is wider than originally described and includes the natural auxin phenylacetic acid (PAA) and the potential SA precursor benzoic acid (BA). Residues that determine IAA versus BA substrate preference were identified. The dual functionality of AtGH3.5 is unique to this enzyme although multiple IAA-conjugating GH3 proteins share nearly identical acyl acid binding sites. In planta analysis of IAA, PAA, SA, and BA and their respective aspartyl conjugates were determined in wild-type and overexpressing lines of A. thaliana. This study suggests that AtGH3.5 conjugates auxins (i.e., IAA and PAA) and benzoates (i.e., SA and BA) to mediate crosstalk between different metabolic pathways, broadening the potential roles for GH3 acyl acid amido synthetases in plants. PMID:27849615

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.

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...

Predictors of bone maturation, growth rate and adult height in children with central precocious puberty treated with depot leuprolide acetate.

PubMed

Klein, Karen O; Dragnic, Sanja; Soliman, Ahmed M; Bacher, Peter

2018-05-11

Children with central precocious puberty (CPP) are treated with gonadotropin-releasing hormone agonists (GnRHa) to suppress puberty. Optimizing treatment outcomes continues to be studied. The relationships between growth, rate of bone maturation (bone age/chronological age [ΔBA/ΔCA]), luteinizing hormone (LH), predicted adult stature (PAS), as well as variables influencing these outcomes, were studied in children treated with depot leuprolide (LA Depot) Methods: Subjects (64 girls, seven boys) with CPP received LA Depot every 3 months for up to 42 months. Multivariate regression analyses were conducted to examine the predictors affecting ΔBA/ΔCA, PAS and growth rate. Ninety percent of subjects (18 of 20) were suppressed (LH levels <4 IU/L) at 42 months. Over 42 months, the mean growth rate declined 2 cm/year, the mean BA/CA ratio decreased 0.21 and PAS increased 8.90 cm for girls (n=64). PAS improved to mid-parental height (MPH) in 46.2% of children by 30 months of treatment. Regression analysis showed that only the Body Mass Index Standardized Score (BMI SDS) was significantly associated (β+0.378 and +0.367, p≤0.05) with growth rate. For PAS, significant correlations were with MPH (β+0.808 and +0.791, p<0.001) and ΔBA/ΔCA (β+0.808 and +0.791, p<0.001). For ΔBA/ΔCA, a significant association was found only with BA at onset of treatment (β-0.098 and -0.103, p≤0.05). Peak-stimulated or basal LH showed no significant influence on growth rate, ΔBA/ΔCA or PAS. Growth rate and bone maturation rate normalized on treatment with LA Depot. LH levels were not significantly correlated with growth rate, ΔBA/ΔCA or PAS, suggesting that suppression was adequate and variations in gonadotropin levels were below the threshold affecting outcomes.

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.

Sol–gel preparation of well-adhered films and long range ordered inverse opal films of BaTiO{sub 3} and Bi{sub 2}Ti{sub 2}O{sub 7}

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

Al-Arjan, Wafa S.; King Faisal University, PO Box 380, Al Hofuf; Algaradah, Mohammed M.F.

Highlights: • Highly adaptable sols are presented for processing of the electroceramic materials BaTiO{sub 3} and Bi{sub 2}Ti{sub 2}O{sub 7}. • High quality thin films are produced by dip coating with good phase control. • Infiltration of cross-linked polystyrene templates led to high quality inverse opals. - Abstract: Barium and bismuth titanate thin films and well-ordered inverse opal films are produced by dip coating from sols containing titanium alkoxides with acetic acid, acetylacetone, methoxyethanol and water. The inverse opal preparations used crosslinked polystyrene opal templates. Heat treatment in air produced tetragonal BaTiO{sub 3} or mixtures of the hexagonal and tetragonalmore » phases, or phase pure Bi{sub 2}Ti{sub 2}O{sub 7}. Good quality films were obtained with a thickness of 5 μm from a single dipping, and the thickness could be increased by dipping multiple times. Inverse opals were well ordered and exhibited opalescence and photonic stop band effects.« less

Biotin-streptavidin enzyme-linked immunosorbent assay for detecting Tetrabromobisphenol A in electronic waste.

PubMed

Bu, Dan; Zhuang, Huisheng; Zhou, Xinchu; Yang, Guangxin

2014-03-01

Tetrabromobisphenol A (TBBPA) is a widely used brominated flame retardant. A sensitive and selective indirect competitive biotin-streptavidin-amplified enzyme-linked immunosorbent assay (BA-ELISA) was developed for detecting TBBPA. The optimal hapten of TBBPA was 2-(2,6-dibromo-4-(2-(3,5-dibromo-4-hydroxyphenly)propan-2-yl)) acetic acid. Several physiochemical factors that influence assay performance, such as optimal coupling concentration of immunogen and antibody, organic solvent, ionic strength, and pH, were studied and optimized. The limit of detection (IC10) was 0.027 ng/mL and the median inhibitory concentration (IC50) was 0.58 ng/mL. The BA-ELISA was highly selective, with low cross-reactivity with TBBPA analogs. Finally, the assay was used to detect TBBPA in electronic waste samples. The results are consistent with those using liquid chromatography, which proves that the proposed immunoassay is accurate and receptive. This BA-ELISA method is suitable for the rapid and sensitive screening of TBBPA in environmental monitoring. © 2013 Published by Elsevier B.V.

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

An improved synthesis and biological evaluation of a new cage-like bifunctional chelator, 4-((8-amino-3,6,10,13,16,19-hexaazabicyclo[6.6.6]icosane-1-ylamino)methyl)benzoic acid, for 64Cu radiopharmaceuticals.

PubMed

Cai, Hancheng; Li, Zibo; Huang, Chiun-Wei; Park, Ryan; Shahinian, Anthony H; Conti, Peter S

2010-01-01

Stable attachment of (64)Cu(2+) to a targeting molecule usually requires the use of a bifunctional chelator (BFC). Sarcophagine (Sar) ligands rapidly coordinate (64)Cu(2+) within the multiple macrocyclic rings comprising the cage structure under mild conditions, providing high stability in vivo. Previously, we have designed a new versatile cage-like BFC Sar ligand, 4-((8-amino-3,6,10,13,16,19-hexaazabicyclo[6.6.6]icosane-1-ylamino)methyl)benzoic acid (AmBaSar), for (64)Cu radiopharmaceuticals. Here we report the improved synthesis of AmBaSar, (64)Cu(2+) labeling conditions and its biological evaluation compared with the known BFC 1,4,7,10-tetraazacyclododecane-N,N',N'',N'''-tetraacetic acid (DOTA). The AmBaSar was synthesized in four steps starting from (1,8-diamine-Sar) cobalt(III) pentachloride ([Co(DiAmSar)]Cl(5)) using an improved synthetic method. The AmBaSar was labeled with (64)Cu(2+) in pH 5.0 ammonium acetate buffer solution at room temperature, followed by analysis and purification with HPLC. The in vitro stability of (64)Cu-AmBaSar complex was evaluated in phosphate buffered saline (PBS), fetal bovine serum and mouse blood. The microPET imaging and biodistribution studies of (64)Cu-AmBaSar were performed in Balb/c mice, and the results were compared with (64)Cu-DOTA. The AmBaSar was readily prepared and characterized by MS and (1)H NMR. The radiochemical yield of (64)Cu-AmBaSar was >or=98% after 30 min of incubation at 25 degrees C. The (64)Cu-AmBaSar complex was analyzed and purified by HPLC with a retention time of 17.9 min. The radiochemical purity of (64)Cu-AmBaSar was more than 97% after 26 h of incubation in PBS or serum. The biological evaluation of (64)Cu-AmBaSar in normal mouse demonstrated renal clearance as the primary mode of excretion, with improved stability in vivo compared to (64)Cu-DOTA. The new cage-like BFC AmBaSar was prepared using a simplified synthetic method. The (64)Cu-AmBaSar complex could be obtained rapidly with high radiochemical yield (>/=98%) under mild conditions. In vitro and in vivo evaluation of AmBaSar demonstrated its promising potential for preparation of (64)Cu radiopharmaceuticals. Copyright 2010. Published by Elsevier Inc.

Improving Effectiveness of Bioremediation at DNAPL Source Zone Sites by Applying Partitioning Electron Donors (PEDs)

DTIC Science & Technology

2014-05-01

as trichloroethene (TCE) and tetrachloroethene (PCE). EISB typically relies on the addition of electron donor formulations to enhance the rate of... value (NPV) cost when applied using passive (i.e., biostimulation) methods. Hence, the selection of electron donors has a major implication on EISB...Engineering Service Center NAVFACSW NAVFAC Southwest nBA n-Butyl acetate nBuOH n-Butanol nHEX n-Hexanol NPV net present value O&M operation and

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...

Verification of key odorants in rose oil by gas chromatography-olfactometry/aroma extract dilution analysis, odour activity value and aroma recombination.

PubMed

Xiao, Zuobing; Li, Jing; Niu, Yunwei; Liu, Qiang; Liu, Junhua

2017-10-01

Rose oil is much too expensive but very popular. It's well known that the flower oil's aroma profile hasn't been intensively investigated. In order to verify the aroma profile of rose oil, the synthetic blend of odorants was prepared and then compared with the original rose oil using electronic nose analysis (ENA) combined with quantitative descriptive analysis (QDA). The odorants from rose oils were screened out by Gas Chromatography-Olfactometry/aroma extract dilution analysis (GC-O/AEDA) combined with odour activity value (OAV). Both ENA and QDA indicated the recombination model derived from OAV and GC-O/AEDA closely resembled the original rose oil. The experiment results show that rose oxide, linalool, α-pinene, β-pinene, nonanal, heptanal citronellal, phenyl ethyl alcohol, benzyl alcohol, eugenol, methyl eugenol, β-citronellol, hexyl acetate, β-ionone, nerol, etc. are very important constituent to rose oil aroma profile.

Laboratory tests of arthropod repellents against Leptotrombidium deliense--noninfected and infected with Rickettsia tsutsugamushi--and noninfected L. fletcheri (Acari: Trombiculidae).

PubMed

Frances, S P; Khlaimanee, N

1996-03-01

Laboratory tests were conducted to compare the response of noninfected Leptotrombidium deliense Sambon and Leptotrombidium fletcheri (Womersley & Heaslip) and L. deliense naturally infected with Rickettsia tsutsugamushi, the etiologic agent of scrub typhus, to 8 chemical repellents and toxicants. Low concentrations of permethrin, dimethylphthalate, diethyl methylbenzamide, benzyl benzoate, di-n-propyl 2,5-pyridine-dicarboxylate, 1-(3-Cyclohexen-1-yl-carbonyl)-2-methylpiperidine (AI3-37220), 2-hydroxymethyl-cyclohexyl acetic acid lactone, and a high concentration of dibutylphthalate (DBP) were toxic for noninfected larvae of both species tested. The median effective knockdown time for all chemicals, except 1% AI3-37220 and 5% permethrin, were longer against infected L. deliense than uninfected larvae of the same species. However, the results indicate that low concentrations of all chemicals, except DBP, should be effective against 2 important vectors of scrub typhus.

Morphohistobiochemical characteristics of embryogenic and nonembryogenic callus cultures of sweet potato (Ipomoea batatas L.).

PubMed

Mukherjee, A; Debata, B K; Mukherjee, P S; Malik, S K

2001-01-01

Ipomoea batatas callus culture raised in a medium supplemented with 2,4-D (2,4-dichlorophenoxy acetic acid) alone or 2,4-D in combination with benzyl adenine, were found to be embryogenic. Supplementation of exogenous chemicals, such as 5 g/l NaCI or 0.7 g/l proline together with a mild dose of 0.2 mg/l 2,4-D, enhanced somatic embryogenesis significantly in all the genotypes tested. Morphological, growth, physiological, histological, and biochemical characteristics of the embryogenic callus were different from the nonembryogenic callus. The former was compact, slow growing, and nodular compared with the fast growing, fragile, nonembryogenic callus. The embryogenic callus tissue had more dry matter, protein and reducing sugar contents compared with the less embryogenic callus. The somatic embryogenic response remained steady in the cultures for up to 96 weeks.

Steric modifications tune the regioselectivity of the alkane oxidation catalyzed by non-heme iron complexes.

PubMed

He, Yu; Gorden, John D; Goldsmith, Christian R

2011-12-19

Iron complexes with the tetradentate N-donor ligand N,N'-di(phenylmethyl)-N,N'-bis(2-pyridinylmethyl)-1,2-cyclohexanediamine (bbpc) are reported. Despite the benzyl groups present on the amines, the iron compounds catalyze the oxygenation of cyclohexane to an extent similar to those employing less sterically encumbered ligands. The catalytic activity is strongly dependent on the counterion, with the highest activity and the strongest preference for alkane hydroxylation correlating to the most weakly coordinating anion, SbF(6)(-). The selectivity for the alcohol product over the ketone is amplified when acetic acid is present as an additive. When hydrocarbon substrates with both secondary and tertiary carbons are oxidized by H(2)O(2), the catalyst directs oxidation toward the secondary carbons to a greater degree than other previously reported iron-containing homogeneous catalysts. © 2011 American Chemical Society

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...

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%.

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.

Comparison of Chemical Extraction Methods for Determination of Soil Potassium in Different Soil Types

NASA Astrophysics Data System (ADS)

Zebec, V.; Rastija, D.; Lončarić, Z.; Bensa, A.; Popović, B.; Ivezić, V.

2017-12-01

Determining potassium supply of soil plays an important role in intensive crop production, since it is the basis for balancing nutrients and issuing fertilizer recommendations for achieving high and stable yields within economic feasibility. The aim of this study was to compare the different extraction methods of soil potassium from arable horizon of different types of soils with ammonium lactate method (KAL), which is frequently used as analytical method for determining the accessibility of nutrients and it is a common method used for issuing fertilizer recommendations in many Europe countries. In addition to the ammonium lactate method (KAL, pH 3.75), potassium was extracted with ammonium acetate (KAA, pH 7), ammonium acetate ethylenediaminetetraacetic acid (KAAEDTA, pH 4.6), Bray (KBRAY, pH 2.6) and with barium chloride (K_{BaCl_2 }, pH 8.1). The analyzed soils were extremely heterogeneous with a wide range of determined values. Soil pH reaction ( {pH_{H_2 O} } ) ranged from 4.77 to 8.75, organic matter content ranged from 1.87 to 4.94% and clay content from 8.03 to 37.07%. In relation to KAL method as the standard method, K_{BaCl_2 } method extracts 12.9% more on average of soil potassium, while in relation to standard method, on average KAA extracts 5.3%, KAAEDTA 10.3%, and KBRAY 27.5% less of potassium. Comparison of analyzed extraction methods of potassium from the soil is of high precision, and most reliable comparison was KAL method with KAAEDTA, followed by a: KAA, K_{BaCl_2 } and KBRAY method. Extremely significant statistical correlation between different extractive methods for determining potassium in the soil indicates that any of the methods can be used to accurately predict the concentration of potassium in the soil, and that carried out research can be used to create prediction model for concentration of potassium based on different methods of extraction.

In vitro propagation and production of cardiotonic glycosides in shoot cultures of Digitalis purpurea L. by elicitation and precursor feeding.

PubMed

Patil, Jitendra Gopichand; Ahire, Mahendra Laxman; Nitnaware, Kirti Manik; Panda, Sayantan; Bhatt, Vijay P; Kishor, Polavarapu B Kavi; Nikam, Tukaram Dayaram

2013-03-01

Digitalis purpurea L. (Scrophulariaceae; Foxglove) is a source of cardiotonic glycosides such as digitoxin and digoxin which are commercially applied in the treatment to strengthen cardiac diffusion and to regulate heart rhythm. This investigation deals with in vitro propagation and elicited production of cardiotonic glycosides digitoxin and digoxin in shoot cultures of D. purpurea L. In vitro germinated seedlings were used as a primary source of explants. Multiple shoot formation was achieved for three explant types (nodal, internodal, and leaf) cultured on Murashige and Skoog (MS) medium with several treatments of cytokinins (6-benzyladenine-BA; kinetin-Kin; and thidiazuron-TDZ) and auxins (indole-3-acetic acid-IAA; α-naphthaleneacetic acid-NAA; and 2,4-dichlorophenoxy acetic acid-2,4-D). Maximum multiple shoots (12.7 ± 0.6) were produced from nodal explants on MS + 7.5 μM BA. Shoots were rooted in vitro on MS containing 15 μM IAA. Rooted plantlets were successfully acclimatized. To further maintain the multiple shoot induction, mother tissue was cut into four equal parts and repeatedly sub-cultured on fresh shoot induction liquid medium after each harvest. On adaptation of this strategy, an average of 18 shoots per explant could be produced. This strategy was applied for the production of biomass and glycosides digitoxin and digoxin in shoot cultures on MS medium supplemented with 7.5 μM BA and several treatments with plant growth regulators, incubation period, abiotic (salicylic acid, mannitol, sorbitol, PEG-6000, NaCl, and KCl), biotic (Aspergillus niger, Helminthosporium sp., Alternaria sp., chitin, and yeast extract) elicitors, and precursors (progesterone, cholesterol, and squalene). The treatment of KCl, mycelial mass of Helminthosporium sp., and progesterone were highly effective for the production of cardenolides. In the presence of progesterone (200 to 300 mg/l), digitoxin and digoxin accumulation was enhanced by 9.1- and 11.9-folds respectively.

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.

In vitro plant regeneration of Aster scaber via somatic embryogenesis.

PubMed

Boo, Kyung Hwan; Cao, Dang Viet; Pamplona, Reniel S; Lee, Doseung; Riu, Key-Zung; Lee, Dong-Sun

2015-01-01

We established an in vitro plant regeneration system via somatic embryogenesis of Aster scaber, an important source of various biologically active phytochemicals. We examined the callus induction and embryogenic capacities of three explants, including leaves, petioles, and roots, on 25 different media containing different combinations of α-naphthalene acetic acid (NAA) and 6-benzyladenine (BA). The optimum concentrations of NAA and BA for the production of embryogenic calli were 5.0 μM and 0.05 μM, respectively. Media containing higher concentrations of auxin and cytokinin (such as 25 μM NAA and 25 μM BA) were suitable for shoot regeneration, especially for leaf-derived calli, which are the most readily available calli and are highly competent. For root induction from regenerated shoots, supplemental auxin and/or cytokinin did not improve rooting, but instead caused unwanted callus induction or retarded growth of regenerated plants. Therefore, plant growth regulator-free medium was preferable for root induction. Normal plants were successfully obtained from calli under the optimized conditions described above. This is the first report of the complete process of in vitro plant regeneration of A. scaber via somatic embryogenesis.

Spin-Coating and Characterization of Multiferroic MFe{sub 2}O{sub 4} (M=Co, Ni) / BaTiO{sub 3} Bilayers

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

Quandt, Norman; Roth, Robert; Syrowatka, Frank

2016-01-15

Bilayer films of MFe{sub 2}O{sub 4} (M=Co, Ni) and BaTiO{sub 3} were prepared by spin coating of N,N-dimethylformamide/acetic acid solutions on platinum coated silicon wafers. Five coating steps were applied to get the desired thickness of 150 nm for both the ferrite and perovskite layer. XRD, IR and Raman spectroscopy revealed the formation of phase-pure ferrite spinels and BaTiO{sub 3}. Smooth surfaces with roughnesses in the order of 3 to 5 nm were found in AFM investigations. Saturation magnetization of 347 emu cm{sup −3} for the CoFe{sub 2}O{sub 4}/BaTiO{sub 3} and 188 emu cm{sup −3} for the NiFe{sub 2}O{sub 4}/BaTiO{submore » 3} bilayer, respectively were found. For the CoFe{sub 2}O{sub 4}/BaTiO{sub 3} bilayer a strong magnetic anisotropy was observed with coercivity fields of 5.1 kOe and 3.3 kOe (applied magnetic field perpendicular and parallel to film surface), while for the NiFe{sub 2}O{sub 4}/BaTiO{sub 3} bilayer this effect is less pronounced. Saturated polarization hysteresis loops prove the presence of ferroelectricity in both systems. - Graphical abstract: The SEM image of the CoFe{sub 2}O{sub 4}/BaTiO{sub 3} bilayer on Pt–Si-substrate (left), magnetization as a function of the magnetic field perpendicular and parallel to the film plane (right top) and P–E and I–V hysteresis loops of the bilayer at room temperature. - Highlights: • Ferrite and perovskite oxides grown on platinum using spin coating technique. • Columnar growth of cobalt ferrite particle on the substrate. • Surface investigation showed a homogenous and smooth surface. • Perpendicular and parallel applied magnetic field revealed a magnetic anisotropy. • Switching peaks and saturated P–E hysteresis loops show ferroelectricity.« less

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.

Bactericidal activities of plant essential oils and some of their isolated constituents against Campylobacter jejuni, Escherichia coli, Listeria monocytogenes, and Salmonella enterica.

PubMed

Friedman, Mendel; Henika, Philip R; Mandrell, Robert E

2002-10-01

An improved method of sample preparation was used in a microplate assay to evaluate the bactericidal activity levels of 96 essential oils and 23 oil compounds against Campylobacter jejuni, Escherichia coli O157:H7, Listeria monocytogenes, and Salmonella enterica obtained from food and clinical sources. Bactericidal activity (BA50) was defined as the percentage of the sample in the assay mixture that resulted in a 50% decrease in CFU relative to a buffer control. Twenty-seven oils and 12 compounds were active against all four species of bacteria. The oils that were most active against C. jejuni (with BA50 values ranging from 0.003 to 0.009) were marigold, ginger root, jasmine, patchouli, gardenia, cedarwood, carrot seed, celery seed, mugwort, spikenard, and orange bitter oils; those that were most active against E. coli (with BA50 values ranging from 0.046 to 0.14) were oregano, thyme, cinnamon, palmarosa, bay leaf, clove bud, lemon grass, and allspice oils; those that were most active against L monocytogenes (with BA50 values ranging from 0.057 to 0.092) were gardenia, cedarwood, bay leaf, clove bud, oregano, cinnamon, allspice, thyme, and patchouli oils; and those that were most active against S. enterica (with BA50 values ranging from 0.045 to 0.14) were thyme, oregano, cinnamon, clove bud, allspice, bay leaf, palmarosa, and marjoram oils. The oil compounds that were most active against C. jejuni (with BA50 values ranging from 0.003 to 0.034) were cinnamaldehyde, estragole, carvacrol, benzaldehyde, citral, thymol, eugenol, perillaldehyde, carvone R, and geranyl acetate; those that were most active against E. coli (with BA50 values ranging from 0.057 to 0.28) were carvacrol, cinnamaldehyde, thymol, eugenol, salicylaldehyde, geraniol, isoeugenol, citral, perillaldehyde, and estragole; those that were most active against L monocytogenes (with BA50 values ranging from 0.019 to 0.43) were cinnamaldehyde, eugenol, thymol, carvacrol, citral, geraniol, perillaldehyde, carvone S, estragole, and salicylaldehyde; and those that were most active against S. enterica (with BA50 values ranging from 0.034 to 0.21) were thymol, cinnamaldehyde, carvacrol, eugenol, salicylaldehyde, geraniol, isoeugenol, terpineol, perillaldehyde, and estragole. The possible significance of these results with regard to food microbiology is discussed.

Utilization of Electrically Reduced Neutral Red by Actinobacillus succinogenes: Physiological Function of Neutral Red in Membrane-Driven Fumarate Reduction and Energy Conservation

PubMed Central

Park, D. H.; Zeikus, J. G.

1999-01-01

Neutral red (NR) functioned as an electronophore or electron channel enabling either cells or membranes purified from Actinobacillus succinogenes to drive electron transfer and proton translocation by coupling fumarate reduction to succinate production. Electrically reduced NR, unlike methyl or benzyl viologen, bound to cell membranes, was not toxic, and chemically reduced NAD. The cell membrane of A. succinogenes contained high levels of benzyl viologen-linked hydrogenase (12.2 U), fumarate reductase (13.1 U), and diaphorase (109.7 U) activities. Fumarate reductase (24.5 U) displayed the highest activity with NR as the electron carrier, whereas hydrogenase (1.1 U) and diaphorase (0.8 U) did not. Proton translocation by whole cells was dependent on either electrically reduced NR or H2 as the electron donor and on the fumarate concentration. During the growth of Actinobacillus on glucose plus electrically reduced NR in an electrochemical bioreactor system versus on glucose alone, electrically reduced NR enhanced glucose consumption, growth, and succinate production by about 20% while it decreased acetate production by about 50%. The rate of fumarate reduction to succinate by purified membranes was twofold higher with electrically reduced NR than with hydrogen as the electron donor. The addition of 2-(n-heptyl)-4-hydroxyquinoline N-oxide to whole cells or purified membranes inhibited succinate production from H2 plus fumarate but not from electrically reduced NR plus fumarate. Thus, NR appears to replace the function of menaquinone in the fumarate reductase complex, and it enables A. succinogenes to utilize electricity as a significant source of metabolic reducing power. PMID:10198002

Biological variation of Vanilla planifolia leaf metabolome.

PubMed

Palama, Tony Lionel; Fock, Isabelle; Choi, Young Hae; Verpoorte, Robert; Kodja, Hippolyte

2010-04-01

The metabolomic analysis of Vanilla planifolia leaves collected at different developmental stages was carried out using (1)H-nuclear magnetic resonance (NMR) spectroscopy and multivariate data analysis in order to evaluate their variation. Ontogenic changes of the metabolome were considered since leaves of different ages were collected at two different times of the day and in two different seasons. Principal component analysis (PCA) and partial least square modeling discriminate analysis (PLS-DA) of (1)H NMR data provided a clear separation according to leaf age, time of the day and season of collection. Young leaves were found to have higher levels of glucose, bis[4-(beta-D-glucopyranosyloxy)-benzyl]-2-isopropyltartrate (glucoside A) and bis[4-(beta-D-glucopyranosyloxy)-benzyl]-2-(2-butyl)-tartrate (glucoside B), whereas older leaves had more sucrose, acetic acid, homocitric acid and malic acid. Results obtained from PLS-DA analysis showed that leaves collected in March 2008 had higher levels of glucosides A and B as compared to those collected in August 2007. However, the relative standard deviation (RSD) exhibited by the individual values of glucosides A and B showed that those compounds vary more according to their developmental stage (50%) than to the time of day or the season in which they were collected (19%). Although morphological variations of the V. planifolia accessions were observed, no clear separation of the accessions was determined from the analysis of the NMR spectra. The results obtained in this study, show that this method based on the use of (1)H NMR spectroscopy in combination with multivariate analysis has a great potential for further applications in the study of vanilla leaf metabolome. Copyright 2009 Elsevier Ltd. All rights reserved.

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.

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

Polycyclic aromatic hydrocarbons as skin carcinogens: Comparison of benzo[a]pyrene, dibenzo[def,p]chrysene and three environmental mixtures in the FVB/N mouse

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

Siddens, Lisbeth K.; Larkin, Andrew; Superfund Research Center, Oregon State University

2012-11-01

The polycyclic aromatic hydrocarbon (PAH), benzo[a]pyrene (BaP), was compared to dibenzo[def,p]chrysene (DBC) and combinations of three environmental PAH mixtures (coal tar, diesel particulate and cigarette smoke condensate) using a two stage, FVB/N mouse skin tumor model. DBC (4 nmol) was most potent, reaching 100% tumor incidence with a shorter latency to tumor formation, less than 20 weeks of 12-O-tetradecanoylphorbol-13-acetate (TPA) promotion compared to all other treatments. Multiplicity was 4 times greater than BaP (400 nmol). Both PAHs produced primarily papillomas followed by squamous cell carcinoma and carcinoma in situ. Diesel particulate extract (1 mg SRM 1650b; mix 1) did notmore » differ from toluene controls and failed to elicit a carcinogenic response. Addition of coal tar extract (1 mg SRM 1597a; mix 2) produced a response similar to BaP. Further addition of 2 mg of cigarette smoke condensate (mix 3) did not alter the response with mix 2. PAH-DNA adducts measured in epidermis 12 h post initiation and analyzed by {sup 32}P post‐labeling, did not correlate with tumor incidence. PAH‐dependent alteration in transcriptome of skin 12 h post initiation was assessed by microarray. Principal component analysis (sum of all treatments) of the 922 significantly altered genes (p < 0.05), showed DBC and BaP to cluster distinct from PAH mixtures and each other. BaP and mixtures up-regulated phase 1 and phase 2 metabolizing enzymes while DBC did not. The carcinogenicity with DBC and two of the mixtures was much greater than would be predicted based on published Relative Potency Factors (RPFs). -- Highlights: ► Dibenzo[def,p]chrysene (DBC), 3 PAH mixtures, benzo[a]pyrene (BaP) were compared. ► DBC and 2 PAH mixtures were more potent than Relative Potency Factor estimates. ► Transcriptome profiles 12 hours post initiation were analyzed by microarray. ► Principle components analysis of alterations revealed treatment-based clustering. ► DBC gave a unique pattern of gene alterations compared to BaP and PAH mixtures.« less

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.

Antioxidant activities and volatile constituents of various essential oils.

PubMed

Wei, Alfreda; Shibamoto, Takayuki

2007-03-07

Thirteen essential oils were examined for their antioxidant activity using three different assay systems. Jasmine, parsley seed, rose, and ylang-ylang oils inhibited hexanal oxidation by over 95% after 40 days at a level of 500 microg/mL in the aldehyde/carboxylic acid assay. Scavenging abilities of the oils for the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical ranged from 39% for angelica seed oil to 90% for jasmine oil at a level of 200 microg/mL. The greatest inhibitory activity toward malonaldehyde (MA) formation from squalene upon UV-irradiation was obtained from parsley seed oil (inhibitory effect, 67%), followed by rose oil (46%), and celery seed oil (23%) at the level of 500 microg/mL. The main compounds of oils showing high antioxidant activity were limonene (composition, 74.6%) in celery seed, benzyl acetate (22.9%) in jasmine, alpha-pinene (33.7%) in juniper berry, myristicin (44%) in parsley seed, patchouli alcohol (28.8%) in patchouli, citronellol (34.2%) in rose, and germacrene (19.1%) in ylang-ylang.

Liquid CO2 extraction of Jasminum grandiflorum and comparison with conventional processes.

PubMed

Prakash, Om; Sahoo, Deeptanjali; Rout, Prasant Kumar

2012-01-01

The concrete (0.35%) of Jasminum grandiflorum L. flowers was prepared by extraction in n-pentane, and the absolute (0.27%) by fractionation of the n-pentane extract (concrete) with cold methanol. Direct extraction of flowers with liquid CO2 gave a relatively fat-free product in 0.26% yield. The liquid CO2 extract was enriched with terpenoids and benzenoids, thus providing the organoleptically accepted product. The major compounds, such as benzyl acetate, (E,E)-alpha-farnesene and (Z)-3-hexenyl benzoate, along with compounds like indole, methyl anthranilate, (Z)-jasmone, (Z)-methyl jasmonoate and (Z)-methyl epi-jasmonoate, are responsible for the high diffusivity of the jasmine fragrance. These compounds have been obtained with improved recoveries in the liquid CO2 extract. On the other hand, the yield of the essential oil was poor (0.05%), and some polar compounds (oxygenated terpenoids) were recovered in less amounts in comparison with either the n-pentane or liquid CO2 extract.

Inter-specific variation in headspace scent volatiles composition of four commercially cultivated jasmine flowers.

PubMed

Bera, Paramita; Kotamreddy, Jhansi Narmada Reddy; Samanta, Tanmoy; Maiti, Saborni; Mitra, Adinpunya

2015-01-01

Jasmines are commercially grown for their fragrant flowers and essential oil production. The flowers of jasmine emit sweet-smelling fragrance from evening till midnight. This study was designed to study the composition and inter-specific variation of the emitted scent volatiles from flowers of four commercially cultivated Jasminum species namely, Jasminum sambac, Jasminum auriculatum, Jasminum grandiflorum and Jasminum multiflorum. Gas chromatography-mass spectrometry analysis revealed that the scent volatiles composition of these flowers was predominantly enriched with both terpenoid and benzenoid compounds. Linalool and (3E,6E)-α-farnesene were identified as the major monoterpene and sesquiterpene in all the four species, respectively. The most abundant benzenoid detected in all flowers was benzyl acetate. Comparison of volatile profiles indicated a variation in fragrance contents and types emitted from these four jasmine flowers. The outcome of this study shall help in elucidating the enzymes and genes of fragrance biosynthesis in jasmines and in aiming to create flowers with improved scent quality.

Parameterization of phosphine ligands demonstrates enhancement of nickel catalysis via remote steric effects.

PubMed

Wu, Kevin; Doyle, Abigail G

2017-08-01

The field of Ni-catalysed cross-coupling has seen rapid recent growth because of the low cost of Ni, its earth abundance, and its ability to promote unique cross-coupling reactions. Whereas advances in the related field of Pd-catalysed cross-coupling have been driven by ligand design, the development of ligands specifically for Ni has received minimal attention. Here, we disclose a class of phosphines that enable the Ni-catalysed Csp 3 Suzuki coupling of acetals with boronic acids to generate benzylic ethers, a reaction that failed with known ligands for Ni and designer phosphines for Pd. Using parameters to quantify phosphine steric and electronic properties together with regression statistical analysis, we identify a model for ligand success. The study suggests that effective phosphines feature remote steric hindrance, a concept that could guide future ligand design tailored to Ni. Our analysis also reveals that two classic descriptors for ligand steric environment-cone angle and % buried volume-are not equivalent, despite their treatment in the literature.

Parameterization of phosphine ligands demonstrates enhancement of nickel catalysis via remote steric effects

NASA Astrophysics Data System (ADS)

Wu, Kevin; Doyle, Abigail G.

2017-08-01

The field of Ni-catalysed cross-coupling has seen rapid recent growth because of the low cost of Ni, its earth abundance, and its ability to promote unique cross-coupling reactions. Whereas advances in the related field of Pd-catalysed cross-coupling have been driven by ligand design, the development of ligands specifically for Ni has received minimal attention. Here, we disclose a class of phosphines that enable the Ni-catalysed Csp3 Suzuki coupling of acetals with boronic acids to generate benzylic ethers, a reaction that failed with known ligands for Ni and designer phosphines for Pd. Using parameters to quantify phosphine steric and electronic properties together with regression statistical analysis, we identify a model for ligand success. The study suggests that effective phosphines feature remote steric hindrance, a concept that could guide future ligand design tailored to Ni. Our analysis also reveals that two classic descriptors for ligand steric environment—cone angle and % buried volume—are not equivalent, despite their treatment in the literature.

Regioselective synthesis of 3-benzyl substituted pyrimidino chromen-2-ones and evaluation of anti-microbial and anti-biofilm activities.

PubMed

Emmadi, Narender Reddy; Atmakur, Krishnaiah; Bingi, Chiranjeevi; Godumagadda, Narender Reddy; Chityal, Ganesh Kumar; Nanubolu, Jagadeesh Babu

2014-01-15

Regioselective synthesis of a number of highly functionalized 3-benzylpyrimidino chromen-2-ones (4) were accomplished in a one pot three component reaction in acetic acid and determined their anti-microbial and anti-biofilm activities. Compounds 4o and 4p showed an excellent anti-microbial activity against Micrococcus luteus MTCC 2470 at a par with standard control (Ciprofloxacin) and exhibited best activity against Staphylococcus aureus MTCC 96 and Bacillus subtilis MTCC 121. Further, compounds 4h, 4i, 4m, 4n and 4q showed promising activity against Micrococcus luteus MTCC 2470, Staphylococcus aureus MTCC 96 and Bacillus subtilis MTCC 121. Whereas, compounds 4m showed very promising biofilm inhibition activity against Staphylococcus aureus MLS 16 MTCC 2940 and 4o, 4p showed very potent activity against Staphylococcus aureus MTCC 96 at a par with Ciprofloxacin used as standard control. Copyright © 2013 Elsevier Ltd. All rights reserved.

An efficient preparation of isosteric phosphonate analogues of sphingolipids by opening of oxirane and cyclic sulfamidate intermediates with alpha-lithiated alkylphosphonic esters.

PubMed

Sun, Chaode; Bittman, Robert

2004-10-29

D-erythro-(2S,3R,4E)-Sphingosine-1-phosphonate (1), the isosteric phosphonate analogue of naturally occurring sphingosine 1-phosphate (1a), and D-ribo-phytosphingosine 1-phosphonate (2), the isosteric phosphonate analogue of D-ribo-phytosphingosine-1-phosphate (2a), were synthesized starting with methyl 2,3-O-isopropylidene-d-glycerate (4) and D-ribo-phytosphingosine (3), respectively. Oxirane 12 was formed in eight steps from 4, and cyclic sulfamidate 22 was formed in five steps from 3. The phosphonate group was introduced via regioselective ring-opening reactions of oxirane 12 and cyclic sulfamidate 22 with lithium dialkyl methylphosphonate, affording 13 and 23, respectively. The synthesis of 1 was completed by S(N)2 displacement of chloromesylate intermediate 14b with azide ion, followed by conversion of the resulting azido group to a NHBoc group and deprotection. The synthesis of 2 was completed by cleavage of the acetal, N-benzyl, and alkyl phosphonate ester groups.

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.

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...

A family of acetato-diphenoxo triply bridged dimetallic Zn(II)Ln(III) complexes: SMM behavior and luminescent properties.

PubMed

Oyarzabal, Itziar; Artetxe, Beñat; Rodríguez-Diéguez, Antonio; García, JoséÁngel; Seco, José Manuel; Colacio, Enrique

2016-06-21

Eleven dimetallic Zn(II)-Ln(III) complexes of the general formula [Zn(µ-L)(µ-OAc)Ln(NO3)2]·CH3CN (Ln(III) = Pr (1), Nd (2), Sm (3), Eu (4), Gd (5), Tb (6), Dy (7), Ho (8), Er (9), Tm (10), Yb (11)) have been prepared in a one-pot reaction from the compartmental ligand N,N'-dimethyl-N,N'-bis(2-hydroxy-3-formyl-5-bromo-benzyl)ethylenediamine (H2L). In all these complexes, the Zn(II) ions occupy the internal N2O2 site whereas the Ln(III) ions show preference for the O4 external site. Both metallic ions are bridged by an acetate bridge, giving rise to triple mixed diphenoxido/acetate bridged Zn(II)Ln(III) compounds. The Nd, Dy, Er and Yb complexes exhibit field induced single-ion magnet (SIM) behaviour, with Ueff values ranging from 14.12 to 41.55 K. The Er complex shows two relaxation processes, but only the second relaxation process with an energy barrier of 21.0 K has been characterized. The chromophoric L(2-) ligand is able to act as an "antenna" group, sensitizing the near-infrared (NIR) Nd(III) and Yb(III)-based luminescence in complexes 2 and 11 and therefore, both compounds can be considered as magneto-luminescent materials. In addition, the Sm(III), Eu(III) and Tb(III) derivatives exhibit characteristic emissions in the visible region.

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.

Localization and structural analysis of a conserved pyruvylated epitope in Bacillus anthracis secondary cell wall polysaccharides and characterization of the galactose-deficient wall polysaccharide from avirulent B. anthracis CDC 684.

PubMed

Forsberg, L Scott; Abshire, Teresa G; Friedlander, Arthur; Quinn, Conrad P; Kannenberg, Elmar L; Carlson, Russell W

2012-08-01

Bacillus anthracis CDC 684 is a naturally occurring, avirulent variant and close relative of the highly pathogenic B. anthracis Vollum. Bacillus anthracis CDC 684 contains both virulence plasmids, pXO1 and pXO2, yet is non-pathogenic in animal models, prompting closer scrutiny of the molecular basis of attenuation. We structurally characterized the secondary cell wall polysaccharide (SCWP) of B. anthracis CDC 684 (Ba684) using chemical and NMR spectroscopy analysis. The SCWP consists of a HexNAc trisaccharide backbone having identical structure as that of B. anthracis Pasteur, Sterne and Ames, →4)-β-d-ManpNAc-(1 → 4)-β-d-GlcpNAc-(1 → 6)-α-d-GlcpNAc-(1→. Remarkably, although the backbone is fully polymerized, the SCWP is the devoid of all galactosyl side residues, a feature which normally comprises 50% of the glycosyl residues on the highly galactosylated SCWPs from pathogenic strains. This observation highlights the role of defective wall assembly in virulence and indicates that polymerization occurs independently of galactose side residue attachment. Of particular interest, the polymerized Ba684 backbone retains the substoichiometric pyruvate acetal, O-acetate and amino group modifications found on SCWPs from normal B. anthracis strains, and immunofluorescence analysis confirms that SCWP expression coincides with the ability to bind the surface layer homology (SLH) domain containing S-layer protein extractable antigen-1. Pyruvate was previously demonstrated as part of a conserved epitope, mediating SLH-domain protein attachment to the underlying peptidoglycan layer. We find that a single repeating unit, located at the distal (non-reducing) end of the Ba684 SCWP, is structurally modified and that this modification is present in identical manner in the SCWPs of normal B. anthracis strains. These polysaccharides terminate in the sequence: (S)-4,6-O-(1-carboxyethylidene)-β-d-ManpNAc-(1 → 4)-[3-O-acetyl]-β-d-GlcpNAc-(1 → 6)-α-d-GlcpNH(2)-(1→.

Rapid Screening of Carboxylic Acids from Waste and Surface Waters by ESI-MS/MS Using Barium Ion Chemistry and On-Line Membrane Sampling.

PubMed

Duncan, Kyle D; Volmer, Dietrich A; Gill, Chris G; Krogh, Erik T

2016-03-01

Negative ion tandem mass spectrometric analysis of aliphatic carboxylic acids often yields only non-diagnostic ([M - H](-)) ions with limited selective fragmentation. However, carboxylates cationized with Ba(2+) have demonstrated efficient dissociation in positive ion mode, providing structurally diagnostic product ions. We report the application of barium adducts followed by collision induced dissociation (CID), to improve selectivity for rapid screening of carboxylic acids in complex aqueous samples. The quantitative MS/MS method presented utilizes common product ions of [M - H + Ba](+) precursor ions. The mechanism of product ion formation is investigated using isotopically labeled standards and a series of structurally related carboxylic acids. The results suggest that hydrogen atoms in the β and γ positions yield common product ions ([BaH](+) and [BaOH](+)). Furthermore, the diagnostic product ion at m/z 196 serves as a qualifying ion for carboxylate species. This methodology has been successfully used in conjunction with condensed phase membrane introduction mass spectrometry (CP-MIMS), with barium acetate added directly to the methanol acceptor phase. The combination enables rapid screening of carboxylic acids directly from acidified water samples (wastewater effluent, spiked natural waters) using a capillary hollow fiber PDMS membrane immersion probe. We have applied this technique for the direct analysis of complex naphthenic acid mixtures spiked into natural surface waters using CP-MIMS. Selectivity at the ionization and tandem mass spectrometry level eliminate isobaric interferences from hydroxylated species present within the samples, which have been observed in negative electrospray ionization.

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.

Degradation of Acetaldehyde and Its Precursors by Pelobacter carbinolicus and P. acetylenicus

PubMed Central

Schmidt, Alexander; Frensch, Marco; Schleheck, David; Schink, Bernhard; Müller, Nicolai

2014-01-01

Pelobacter carbinolicus and P. acetylenicus oxidize ethanol in syntrophic cooperation with methanogens. Cocultures with Methanospirillum hungatei served as model systems for the elucidation of syntrophic ethanol oxidation previously done with the lost “Methanobacillus omelianskii” coculture. During growth on ethanol, both Pelobacter species exhibited NAD+-dependent alcohol dehydrogenase activity. Two different acetaldehyde-oxidizing activities were found: a benzyl viologen-reducing enzyme forming acetate, and a NAD+-reducing enzyme forming acetyl-CoA. Both species synthesized ATP from acetyl-CoA via acetyl phosphate. Comparative 2D-PAGE of ethanol-grown P. carbinolicus revealed enhanced expression of tungsten-dependent acetaldehyde: ferredoxin oxidoreductases and formate dehydrogenase. Tungsten limitation resulted in slower growth and the expression of a molybdenum-dependent isoenzyme. Putative comproportionating hydrogenases and formate dehydrogenase were expressed constitutively and are probably involved in interspecies electron transfer. In ethanol-grown cocultures, the maximum hydrogen partial pressure was about 1,000 Pa (1 mM) while 2 mM formate was produced. The redox potentials of hydrogen and formate released during ethanol oxidation were calculated to be EH2 = -358±12 mV and EHCOOH = -366±19 mV, respectively. Hydrogen and formate formation and degradation further proved that both carriers contributed to interspecies electron transfer. The maximum Gibbs free energy that the Pelobacter species could exploit during growth on ethanol was −35 to −28 kJ per mol ethanol. Both species could be cultivated axenically on acetaldehyde, yielding energy from its disproportionation to ethanol and acetate. Syntrophic cocultures grown on acetoin revealed a two-phase degradation: first acetoin degradation to acetate and ethanol without involvement of the methanogenic partner, and subsequent syntrophic ethanol oxidation. Protein expression and activity patterns of both Pelobacter spp. grown with the named substrates were highly similar suggesting that both share the same steps in ethanol and acetalydehyde metabolism. The early assumption that acetaldehyde is a central intermediate in Pelobacter metabolism was now proven biochemically. PMID:25536080

Determination of polycyclic aromatic hydrocarbons (PAHs) in seafood using gas chromatography-mass spectrometry: collaborative study.

PubMed

Mastovska, Katerina; Sorenson, Wendy R; Hajslova, Jana

2015-01-01

A collaborative study was conducted to determine selected polycyclic aromatic hydrocarbons (PAHs) and their relevant alkyl homologs in seafood matrixes using a fast sample preparation method followed by analysis with GC/MS. The sample preparation method involves addition of (13)C-PAH surrogate mixture to homogenized samples and extraction by shaking with a water-ethyl acetate mixture. After phase separation induced by addition of anhydrous magnesium sulfate-sodium chloride (2 + 1, w/w) and centrifugation, an aliquot of the ethyl acetate layer is evaporated, reconstituted in hexane, and cleaned up using silica gel SPE. The analytes are eluted with hexane-dichloromethane (3 + 1, v/v), the clean extract is carefully evaporated, reconstituted in isooctane, and analyzed by GC/MS. To allow for the use of various GC/MS instruments, GC columns, silica SPE cartridges, and evaporation techniques and equipment, performance-based criteria were developed and implemented in the qualification phase of the collaborative study. These criteria helped laboratories optimize their GC/MS, SPE cleanup, and evaporation conditions; check and eliminate potential PAH contamination in their reagent blanks; and become familiar with the method procedure. Ten laboratories from five countries qualified and completed the collaborative study, which was conducted on three seafood matrixes (mussel, oyster, and shrimp) fortified with 19 selected PAH analytes at five different levels of benzo[a]pyrene (BaP) ranging from 2 to 50 μg/kg. Each matrix had a varying mixture of three different BaP levels. The other studied PAHs were at varying levels from 2 to 250 μg/kg to mimic typical PAH patterns. The fortified analytes in three matrixes were analyzed as blind duplicates at each level of BaP and corresponding other PAH levels. In addition, a blank with no added PAHs for each matrix was analyzed singly. Eight to 10 valid results were obtained for the majority of determinations. Mean recoveries of all tested analytes at the five different concentration levels were all in the range of 70-120%: 83.8-115% in shrimp, 77.3-107% in mussel, and 71.6-94.6% in oyster, except for a slightly lower mean recovery of 68.6% for benzo[ a ]anthracene fortified at 25 μg/kg in oyster (RSDr: 5.84%, RSDR: 21.1%) and lower mean recoveries for anthracene (Ant) and BaP in oyster at all three fortification levels (50.3-56.5% and 48.2-49.7%, respectively). The lower mean recoveries of Ant and BaP were linked to degradation of these analytes in oyster samples stored at -20°C, which also resulted in lower reproducibility (RSDR values in the range of 44.5-64.7% for Ant and 40.6-43.5% for BaP). However, the repeatability was good (RSDr of 8.78-9.96% for Ant and 6.43-11.9% for BaP), and the HorRat values were acceptable (1.56-1.94 for Ant and 1.10-1.45 for BaP). In all other cases, repeatability, reproducibility, and HorRat values were as follows: shrimp: RSDr 1.40-26.9%, RSDR 5.41-29.4%, HorRat: 0.22-1.34; mussel: RSDr 2.52-17.1%, RSDR 4.19-32.5%, HorRat: 0.17-1.13; and oyster: RSDr 3.12-22.7%, RSDR 8.41-31.8%, HorRat: 0.34-1.39. The results demonstrate that the method is fit-for-purpose to determine PAHs and their alkyl homologs in seafood samples. The method was approved by the Expert Review Panel on PAHs as the AOAC Official First Action Method 2014.08.

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.

Taming the Reactivity of Glycosyl Iodides To Achieve Stereoselective Glycosidation.

PubMed

Gervay-Hague, Jacquelyn

2016-01-19

Although glycosyl iodides have been known for more than 100 years, it was not until the 21st century that their full potential began to be harnessed for complex glycoconjugate synthesis. Mechanistic studies in the late 1990s probed glycosyl iodide formation by NMR spectroscopy and revealed important reactivity features embedded in protecting-group stereoelectronics. Differentially protected sugars having an anomeric acetate were reacted with trimethylsilyl iodide (TMSI) to generate the glycosyl iodides. In the absence of C-2 participation, generation of the glycosyl iodide proceeded by inversion of the starting anomeric acetate stereochemistry. Once formed, the glycosyl iodide readily underwent in situ anomerization, and in the presence of excess iodide, equilibrium concentrations of α- and β-iodides were established. Reactivity profiles depended upon the identity of the sugar and the protecting groups adorning it. Consistent with the modern idea of disarmed versus armed sugars, ester protecting groups diminished the reactivity of glycosyl iodides and ether protecting groups enhanced the reactivity. Thus, acetylated sugars were slower to form the iodide and anomerize than their benzylated analogues, and these disarmed glycosyl iodides could be isolated and purified, whereas armed ether-protected iodides could only be generated and reacted in situ. All other things being equal, the β-iodide was orders of magnitude more reactive than the thermodynamically more stable α-iodide, consistent with the idea of in situ anomerization introduced by Lemieux in the mid-20th century. Glycosyl iodides are far more reactive than the corresponding bromides, and with the increased reactivity comes increased stereocontrol, particularly when forming α-linked linear and branched oligosaccharides. Reactions with per-O-silylated glycosyl iodides are especially useful for the synthesis of α-linked glycoconjugates. Silyl ether protecting groups make the glycosyl iodide so reactive that even highly functionalized aglycon acceptors add. Following the coupling event, the TMS ethers are readily removed by methanolysis, and since all of the byproducts are volatile, multiple reactions can be performed in a single reaction vessel without isolation of intermediates. In this fashion, per-O-TMS monosaccharides can be converted to biologically relevant α-linked glycolipids in one pot. The stereochemical outcome of these reactions can also be switched to β-glycoside formation by addition of silver to chelate the iodide, thus favoring SN2 displacement of the α-iodide. While iodides derived from benzyl and silyl ether-protected oligosaccharides are susceptible to interglycosidic bond cleavage when treated with TMSI, the introduction of a single acetate protecting group prevents this unwanted side reaction. Partial acetylation of armed glycosyl iodides also attenuates HI elimination side reactions. Conversely, fully acetylated glycosyl iodides are deactivated and require metal catalysis in order for glycosidation to occur. Recent findings indicate that I2 activation of per-O-acetylated mono-, di-, and trisaccharides promotes glycosidation of cyclic ethers to give β-linked iodoalkyl glycoconjugates in one step. Products of these reactions have been converted into multivalent carbohydrate displays. With these synthetic pathways elucidated, chemical reactivity can be exquisitely controlled by the judicious selection of protecting groups to achieve high stereocontrol in step-economical processes.

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

Modulation of gut microbiota during probiotic-mediated attenuation of metabolic syndrome in high fat diet-fed mice

PubMed Central

Wang, Jingjing; Tang, Huang; Zhang, Chenhong; Zhao, Yufeng; Derrien, Muriel; Rocher, Emilie; van-Hylckama Vlieg, Johan ET; Strissel, Katherine; Zhao, Liping; Obin, Martin; Shen, Jian

2015-01-01

Structural disruption of gut microbiota and associated inflammation are considered important etiological factors in high fat diet (HFD)-induced metabolic syndrome (MS). Three candidate probiotic strains, Lactobacillus paracasei CNCM I-4270 (LC), L. rhamnosus I-3690 (LR) and Bifidobacterium animalis subsp. lactis I-2494 (BA), were individually administered to HFD-fed mice (108 cells day−1) for 12 weeks. Each strain attenuated weight gain and macrophage infiltration into epididymal adipose tissue and markedly improved glucose–insulin homeostasis and hepatic steatosis. Weighted UniFrac principal coordinate analysis based on 454 pyrosequencing of fecal bacterial 16S rRNA genes showed that the probiotic strains shifted the overall structure of the HFD-disrupted gut microbiota toward that of lean mice fed a normal (chow) diet. Redundancy analysis revealed that abundances of 83 operational taxonomic units (OTUs) were altered by probiotics. Forty-nine altered OTUs were significantly correlated with one or more host MS parameters and were designated ‘functionally relevant phylotypes'. Thirteen of the 15 functionally relevant OTUs that were negatively correlated with MS phenotypes were promoted, and 26 of the 34 functionally relevant OTUs that were positively correlated with MS were reduced by at least one of the probiotics, but each strain changed a distinct set of functionally relevant OTUs. LC and LR increased cecal acetate but did not affect circulating lipopolysaccharide-binding protein; in contrast, BA did not increase acetate but significantly decreased adipose and hepatic tumor necrosis factor-α gene expression. These results suggest that Lactobacillus and Bifidobacterium differentially attenuate obesity comorbidities in part through strain-specific impacts on MS-associated phylotypes of gut microbiota in mice. PMID:24936764

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

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

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

Phytochemicals from Mangifera pajang Kosterm and their biological activities.

PubMed

Ahmad, Sadikah; Sukari, Mohd Aspollah; Ismail, Nurussaadah; Ismail, Intan Safinar; Abdul, Ahmad Bustamam; Abu Bakar, Mohd Fadzelly; Kifli, Nurolaini; Ee, Gwendoline C L

2015-03-26

Mangifera pajang Kosterm is a plant species from the mango family (Anacardiaceae). The fruits are edible and have been reported to have high antioxidant content. However, the detailed phytochemical studies of the plant have not been reported previously. This study investigates the phytochemicals and biological activities of different parts of Mangifera pajang. The plant samples were extracted with solvents of different polarity to obtain the crude extracts. The isolated compounds were characterized using spectroscopic methods. The extracts and isolated compounds were subjected to cytotoxicity tests using human breast cancer (MCF-7), human cervical cancer (HeLa) and human colon cancer (HT-29) cells. The free radical scavenging activity test was conducted using the DPPH assay. Antimicrobial activity tests were carried out by using the disc diffusion method. Phytochemical investigation on the kernel, stem bark and leaves of Mangifera pajang led to the isolation of methyl gallate (1), mixture of benzaldehyde (2) and benzyl alcohol (3), mangiferonic acid (4), 3β-hydroxy-cycloart-24-ene-26-oic acid (5), 3β,23-dihydroxy-cycloart-24-ene-26-oic acid (6), lupeol(7) lupenone(8), β-sitosterol(9), stigmasterol(10), trans-sobrerol(11) and quercitrin (12). Crude ethyl acetate and methanol extracts from the kernel indicated strong cytotoxic activity towards MCF-7 and HeLa cells with IC50 values of less than 10 μg/mL, while petroleum ether, chloroform and ethyl acetate extracts of the stem bark showed strong to moderate activity against MCF-7, HeLa and HT-29 cancer cell lines with IC50 values ranging from 5 to 30 μg/mL. As for the antimicrobial assays, only the ethyl acetate and methanol extracts from the kernel displayed some inhibition against the microbes in the antibacterial assays. The kernel extracts showed highest free radical scavenging activity with IC50 values of less than 10 μg/mL, while the ethyl acetate and methanol extracts of leaves displayed only weak activity in the DPPH assays. Phytochemical investigations on various parts of Mangifera pajang have identified terpenoids and a flavonol derivative as major constituents. Bioassay studies have indicated that the crude extracts and isolated compounds have potential as naturally-derived anticancer and antimicrobial agents, besides possess high free radical scavenging activity.

Acid-Sensitive Sheddable PEGylated, Mannose-Modified Nanoparticles Increase the Delivery of Betamethasone to Chronic Inflammation Sites in a Mouse Model.

PubMed

O'Mary, Hannah L; Aldayel, Abdulaziz M; Valdes, Solange A; Naguib, Youssef W; Li, Xu; Salvady, Karun; Cui, Zhengrong

2017-06-05

Inflammation is implicated in a host of chronic illnesses. Within these inflamed tissues, the pH of the microenvironment is decreased and immune cells, particularly macrophages, infiltrate the area. Additionally, the vascular integrity of these sites is altered with increased fenestrations between endothelial cells. These distinctive properties may be exploited to enhance targeted delivery of anti-inflammatory therapies. Using a mouse model of chronic inflammation, we previously showed that acid-sensitive sheddable PEGylation increases the distribution and retention of nanoparticles in chronic inflammation sites. Here we demonstrated that surface modification of the acid-sensitive sheddable PEGylated nanoparticles with mannose, a ligand to mannose receptors present in chronic inflammation sites, significantly increases the targeted delivery of the nanoparticles to these areas. Furthermore, we showed that the acid-sensitive sheddable PEGylated, mannose-modified nanoparticles are able to significantly increase the delivery of betamethasone-21-acetate (BA), a model anti-inflammatory compound, to chronic inflammation sites as compared to free BA. These results highlight the ability to engineer formulations to target chronic inflammation sites by exploiting the microenvironment of these regions.

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.

Discovery of an Oxybenzylglycine Based Peroxisome Proliferator Activated Receptor [alpha] Selective Agonist 2-((3-((2-(4-Chlorophenyl)-5-methyloxazol-4-yl)methoxy)benzyl)(methoxycarbonyl)amino)acetic Acid (BMS-687453)

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

Li, Jun; Kennedy, Lawrence J.; Shi, Yan

2010-04-12

An 1,3-oxybenzylglycine based compound 2 (BMS-687453) was discovered to be a potent and selective peroxisome proliferator activated receptor (PPAR) {alpha} agonist, with an EC{sub 50} of 10 nM for human PPAR{alpha} and 410-fold selectivity vs human PPAR{gamma} in PPAR-GAL4 transactivation assays. Similar potencies and selectivity were also observed in the full length receptor co-transfection assays. Compound 2 has negligible cross-reactivity against a panel of human nuclear hormone receptors including PPAR{delta}. Compound 2 demonstrated an excellent pharmacological and safety profile in preclinical studies and thus was chosen as a development candidate for the treatment of atherosclerosis and dyslipidemia. The X-ray cocrystalmore » structures of the early lead compound 12 and compound 2 in complex with PPAR{alpha} ligand binding domain (LBD) were determined. The role of the crystal structure of compound 12 with PPAR{alpha} in the development of the SAR that ultimately resulted in the discovery of compound 2 is discussed.« less

An efficient in vitro regeneration protocol for a natural dye yielding plant, Strobilanthes flaccidifolious Nees., from nodal explants.

PubMed

Deb, Chitta Ranjan; Arenmongla, T

2012-11-01

Adventitious shoot buds formation from axillary buds of nodal segments of S. flaccidifolious was achieved on MS medium containing sucrose (3%, w/v), and a-naphthalene acetic acid (NAA; 3 microM) and benzyl adenine (3 microM) in combination. The nodal segments were primed on 'Growtak Sieve' for 48 h on MS medium containing sucrose (2%), polyvinyl pyrollidone (200 mgL(-1)) as antioxidant. About 80% of primed nodal segments responded positively and formed approximately 12 adventitious shoot buds per explants from explants collected during October-November months of every year. The shoot buds converted into plantlets on MS medium containing sucrose (3%) and kinetin (3 microM) where approximately 7 micro shoots developed per subculture after 8 weeks of culture. The regenerated micro shoots induced average 14 roots/plant on medium containing NAA (3 microM). The regenerates were hardened for 6-7 weeks on medium with 1/2MS salt solution and sucrose (2%) under normal laboratory condition before transferring to potting mix. About 70% transplants survived after two months of transfer.

Simultaneous structure-activity studies and arming of natural products by C-H amination reveal cellular targets of eupalmerin acetate

NASA Astrophysics Data System (ADS)

Li, Jing; Cisar, Justin S.; Zhou, Cong-Ying; Vera, Brunilda; Williams, Howard; Rodríguez, Abimael D.; Cravatt, Benjamin F.; Romo, Daniel

2013-06-01

Natural products have a venerable history of, and enduring potential for the discovery of useful biological activity. To fully exploit this, the development of chemical methodology that can functionalize unique sites within these complex structures is highly desirable. Here, we describe the use of rhodium(II)-catalysed C-H amination reactions developed by Du Bois to carry out simultaneous structure-activity relationship studies and arming (alkynylation) of natural products at ‘unfunctionalized’ positions. Allylic and benzylic C-H bonds in the natural products undergo amination while olefins undergo aziridination, and tertiary amine-containing natural products are converted to amidines by a C-H amination-oxidation sequence or to hydrazine sulfamate zwitterions by an unusual N-amination. The alkynylated derivatives are ready for conversion into cellular probes that can be used for mechanism-of-action studies. Chemo- and site-selectivity was studied with a diverse library of natural products. For one of these—the marine-derived anticancer diterpene, eupalmerin acetate—quantitative proteome profiling led to the identification of several protein targets in HL-60 cells, suggesting a polypharmacological mode of action.

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).

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)

"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.

In vitro propagation, ex vitro rooting and leaf micromorphology of Bauhinia racemosa Lam.: a leguminous tree with medicinal values.

PubMed

Sharma, Udit; Kataria, Vinod; Shekhawat, N S

2017-10-01

A micropropagation system for Bauhinia racemosa Lam. was developed involving axillary shoot proliferation and ex vitro rooting using nodal explants obtained from mature tree. MS medium with 3.0 mg l -1 BA (6-benzyladenine) was optimum for shoot bud induction. For shoot multiplication, mother explants were transferred repeatedly on medium containing low concentration of BA (0.75 mg l -1 ). Number of shoots was increased up to two passages and decreased thereafter. Shoot multiplication was further enhanced on MS medium containing 0.25 mg l -1 each of BA and Kin (Kinetin) with 0.1 mg l -1 of NAA (α-naphthalene acetic acid). Addition of 0.004 mg l -1 TDZ (thidiazuron) increased the rate of shoot multiplication and 21.81 ± 1.26 shoots per culture vessel were obtained. In vitro regenerated shoots were rooted under ex vitro conditions treated with 400 mg l -1 IBA (indole-3-butyric acid) for 7 min on sterile soilrite. After successful hardening in greenhouse, ex vitro rooted plants were transferred to the field conditions with ≈85% of survival rate. Micromorphological changes were observed on leaf surface i.e. development of vein density and trichomes and stomatal appearance, when plants were subjected to environmental conditions. This is the first report on in vitro regeneration of B. racemosa from mature tree.

[Effects of combined pollution of lead and benzo[a] pyrene on seed growth of wheat in soils].

PubMed

Wang, Hong-Qi; Wang, Shuai; Ning, Shao-Wei; Sun, Yan-Ling; Hou, Ze-Qing

2011-03-01

Seed germination, root elongation, shoot elongation and ratio of shoot to root of wheat in soils polluted by lead (Pb) and benzo (a)pyrene (B[a] P) with medium-low concentrations were studied to reveal the ecological effects of combined pollution and screen the indicative markers. Results indicated that seed germination was not sensitive to single or combined pollution of Pb or B[a] P. Root elongation was inhibited by single pollution of Pb or B[a]P to different extents. Extensive interactions between Pb and B[a]P occurred to root elongation of wheat, including synergistic-stimulatory effect and antagonistic-inhibitory effect. The joint action was mainly antagonistic. Single pollution of B [a] P had an inhibitory effect on shoot elongation. Under combined pollution conditions, the shoot elongation of wheat correlated well with Pb contents (p < 0.01). B[a] P or the interactions between pollutants had little effect on shoot elongation of wheat. The joint action on shoot elongation was consistently antagonistic. The response pattern of the ratio of shoot to root was similar to the response pattern of shoot elongation. However, the former had better correlation than the latter, indicating it as a more suitable indicative marker for Pb pollution. If lead acetate was employed instead of lead nitrate, longer root elongation, shorter shoot elongation and no effect on ratio of shoot to root were found. Therefore, the forms of Pb salt had significant influence on seed growth of wheat in soils.

Embling Production in Althaea officinalis L., Through Somatic Embryogenesis and Their Appraisal via Histological and Scanning Electron Microscopical Studies.

PubMed

Naz, Ruphi; Anis, Mohammad; Alatar, Abdulrahman A

2017-07-01

In vitro propagation of a medicinally important plant, Althaea officinalis, has been achieved through somatic embryogenesis. Somatic embryos (globular to torpedo-shaped embryos) were induced on Murashige and Skoog's (MS) medium augmented with various concentrations of 2,4-dichlorophenoxyacetic acid (2,4-D, 5.0, 10.0, 15.0, 20.0, and 25.0) alone or combined with N6-benzylaminopurine (BA, 0.1, 0.5, 1.0, 1.5, and 2.0 μM). These were directly formed from the cut ends and subsequently spread on the whole surface of internodal explants. For embryo maturation, torpedo embryos were transferred on a medium containing different levels of BA (0.1, 0.5, or 1.0 μM) and abscisic acid (ABA) (0.5, 1.0, or 1.5 μM) or α-naphthalene acetic acid (NAA) (0.1, 0.5 or 1.0 μM). Among the different concentrations tested, 0.5 μM BA along with 1.0 μM ABA was found most effective, on which a highest yield (58.0%) with an optimum number (35.0) of mature embryos (cotyledonary stage) was observed after 2 weeks of transfer. Germination of cotyledonary embryos into plantlets with 68% were observed on ½ MS medium. Histological and scanning electron microscopical (SEM) studies proved that the regenerated structures were somatic embryos and not shoot primordia. Plants grew vigorously when transferred to a greenhouse.

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.

High fluorescence emission of carboxylic acid functionalized polystyrene/BaTiO{sub 3} nanocomposites and rare earth metal complexes: Preparation and characterization

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

Cao, X. T.; Showkat, A. M.; Wang, Z.

2015-03-30

Noble fluorescence nanocomposite compound based on barium titanate nanoparticles (BTO), polystyrene (PSt), and terbium ion (Tb{sup 3+}) was synthesized by a combination of surface-initiated reversible addition-fragmentation chain transfer (RAFT) polymerization, Friedel-Crafts alkylation reaction and coordinate chemistry. Initially, a modification of surface of BTO was conducted by an exchange process with S-benzyl S’-trimethoxysilylpropyltrithiocarbonate to create macro-initiator for polymerization of styrene. Subsequently, aryl carboxylic acid functionalized polystyrene grafted barium titanate (BTO-g-PSt-COOH) was generated by substitution reaction between 4-(Chloromethyl) benzoic acid and PSt chains. The coordination of the nanohybrids with Tb{sup 3+} ions afforded fluorescent Tb{sup 3+} tagged aryl carboxylic acid functionalized polystyrenemore » grafted barium titanate (BTO-g-PSt-Tb{sup 3+}) complexes. Structure, morphology, and fluorescence properties of nanohybrid complexes were investigated by respective physical and spectral studies. FT-IR and SEM analyses confirmed the formation of BTO-g-PSt-Tb{sup 3+}nanohybrids. Furthermore, TGA profiles demonstrated the grafting of aryl carboxylic acid functionalized polystyrene on BTO surface. Optical properties of BTO-g-PSt-Tb{sup 3+} complexes were investigated by fluorescence spectroscopy.« less

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.

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...

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

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.

Ion-pair in-tube solid-phase microextraction and capillary liquid chromatography using a titania-based column: application to the specific lauralkonium chloride determination in water.

PubMed

Prieto-Blanco, M C; Moliner-Martínez, Y; López-Mahía, P; Campíns-Falcó, P

2012-07-27

A quick, miniaturized and on-line method has been developed for the determination in water of the predominant homologue of benzalkonium chloride, dodecyl dimethyl benzyl ammonium chloride or lauralkonium chloride (C(12)-BAK). The method is based on the formation of an ion-pair in both in-tube solid-phase microextraction (IT-SPME) and capillary liquid chromatography. The IT-SPME optimization required the study of the length and nature of the stationary phase of capillary and the processed sample volume. Because to the surfactant character of the analyte both, the extracting and replacing solvents, have played a decisive role in the IT-SPME optimized procedure. Conditioning the capillary with the mobile phase which contains the counter ion (acetate), using an organic additive (tetrabutylammonium chloride) added to the sample and a mixture water/methanol as replacing solvent (processed just before the valve is switched to the inject position), allowed to obtain good precision of the retention time and a narrow peak for C(12)-BAK. A reversed-phase capillary based TiO(2) column and a mobile phase containing ammonium acetate at pH 5.0 for controlling the interactions of cationic surfactant with titania surface were proposed. The optimized procedure provided adequate linearity, accuracy and precision at the concentrations interval of 1.5-300 μg L(-1) .The limit of detection (LOD) was 0.5 μg L(-1) using diode array detection (DAD). The applicability of proposed IT-SPME-capillary LC method has been assessed in several water samples. Copyright © 2012 Elsevier B.V. All rights reserved.

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.

Mechanochemical synthesis, structure and properties of lead containing alkaline earth metal fluoride solid solutions MxPb1-xF2 (M = Ca, Sr, Ba)

NASA Astrophysics Data System (ADS)

Heise, M.; Scholz, G.; Düvel, A.; Heitjans, P.; Kemnitz, E.

2018-03-01

The paper deals with the mechanochemical synthesis of lead containing alkaline earth metal fluoride solid solutions MxPb1-xF2 (M = Ca, Sr, Ba) by high-energy ball milling. Several metal precursors and fluorinating agents were tested for synthesizing M0.5Pb0.5F2. Metal acetates and ammonium fluoride as precursors show the most promising results and were therefore used for the formation of MxPb1-xF2 with different metal cationic ratios. The characterization of the local fluorine coordination and the crystal structure was performed by 19F MAS NMR spectroscopy and X-ray diffraction. Additional calculations of 19F chemical shifts using the superposition model allow a deeper insight into the local structure of the compounds. The fluoride ion conductivity was followed by temperature dependent DC conductivity measurements. Significantly higher conductivities were found in comparison with those of the corresponding binary fluorides. The highest values were observed for samples with high lead content M0.25Pb0.75F2, bearing in mind the much higher conductivity of PbF2 compared to MF2.

Acid-sensitive sheddable PEGylated, mannose-modified nanoparticles increase the delivery of betamethasone to chronic inflammation sites in a mouse model

PubMed Central

O’Mary, Hannah L.; Aldayel, Abdulaziz M.; Valdes, Solange A.; Naguib, Youssef W.; Li, Xu; Salvady, Karun; Cui, Zhengrong

2017-01-01

Inflammation is implicated in a host of chronic illnesses. Within these inflamed tissues, the pH of the microenvironment is decreased and immune cells, particularly macrophages, infiltrate the area. Additionally, the vascular integrity of these sites is altered with increased fenestrations between endothelial cells. These distinctive properties may be exploited to enhance targeted delivery of anti-inflammatory therapies. Using a mouse model of chronic inflammation, we previously showed that acid-sensitive sheddable PEGylation increases the distribution and retention of nanoparticles in chronic inflammation sites. Here we demonstrated that surface modification of the acid-sensitive sheddable PEGylated nanoparticles with mannose, a ligand to mannose receptors present in chronic inflammation sites, significantly increases the targeted delivery of the nanoparticles to these areas. Furthermore, we showed that the acid-sensitive sheddable PEGylated, mannose-modified nanoparticles are able to significantly increase the delivery of betamethasone-21-acetate (BA), a model anti-inflammatory compound, to chronic inflammation sites as compared to free BA. These results highlight the ability to engineer formulations to target chronic inflammation sites by exploiting the microenvironment of these regions. PMID:28463518

Alkaline earth metal doped tin oxide as a novel oxygen storage material

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

Dong, Qiang, E-mail: dong@tagen.tohoku.ac.jp; Yin, Shu; Yoshida, Mizuki

2015-09-15

Alkaline earth metal doped tin oxide (SnO{sub 2}) hollow nanospheres with a diameter of 50 nm have been synthesized successfully via a facial solvothermal route in a very simple system composed of only ethanol, acetic acid, SnCl{sub 4}·5H{sub 2}O and A(NO{sub 3}){sub 2}·xH{sub 2}O (A = Mg, Ca, Sr, Ba). The synthesized undoped SnO{sub 2} and A-doped SnO{sub 2} hollow nanospheres were characterized by the oxygen storage capacity (OSC), X-ray diffraction, transmission electron microscopy and the Brunauer–Emmet–Teller (BET) technique. The OSC values of all samples were measured using thermogravimetric-differential thermal analysis. The incorporation of alkaline earth metal ion into tinmore » oxide greatly enhanced the thermal stability and OSC. Especially, Ba-doped SnO{sub 2} hollow nanospheres calcined at 1000 °C for 20 h with a BET surface area of 61 m{sup 2} g{sup −1} exhibited the considerably high OSC of 457 μmol-O g{sup −1} and good thermal stability. Alkaline earth metal doped tin oxide has the potential to be a novel oxygen storage material.« less

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…

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

Piper nigrum: micropropagation, antioxidative enzyme activities, and chromatographic fingerprint analysis for quality control.

PubMed

Ahmad, Nisar; Abbasi, Bilal Haider; Rahman, Inayat ur; Fazal, Hina

2013-04-01

A reliable in vitro regeneration system for the economical and medicinally important Piper nigrum L. has been established. Callus and shoot regeneration was encouraged from leaf portions on Murashige and Skoog (MS) medium augmented with varied concentrations of plant growth regulators. A higher callus production (90 %) was observed in explants incubated on MS medium incorporated with 1.0 mg L(-1) 6-benzyladenine (BA) along with 0.5 mg L(-1) gibberellic acid after 4 weeks of culture. Moreover, a callogenic response of 85 % was also recorded for 1.0 mg L(-1) BA in combination with 0.25 mg L(-1) α-naphthalene acetic acid (NAA) and 0.25 mg L(-1) 2,4-dichlorophenoxyacetic acid or 0.5 mg L(-1) indole butyric acid (IBA) along with 0.25 mg L(-1) NAA and indole acetic acid. Subsequent sub-culturing of callus after 4 weeks of culture onto MS medium supplemented with 1.5 mg L(-1) thiodiazoran or 1.5 mg L(-1) IBA induced 100 % shoot response. Rooted plantlets were achieved on medium containing varied concentrations of auxins. The antioxidative enzyme activities [superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), and ascorbate peroxidase (APX)] revealed that significantly higher SOD was observed in regenerated plantlets than in other tissues. However, POD, CAT, and APX were higher in callus than in other tissues. A high-performance liquid chromatography (HPLC) fingerprint analysis protocol was established for quality control in different in vitro-regenerated tissues of P. nigrum L. During analysis, most of the common peaks represent the active principle "piperine." The chemical contents, especially piperine, showed variation from callus culture to whole plantlet regeneration. Based on the deviation in chromatographic peaks, the in vitro-regenerated plantlets exhibit a nearly similar piperine profile to acclimated plantlets. The in vitro regeneration system and HPLC fingerprint analysis established here brought a novel approach to the quality control of in vitro plantlets, producing metabolites of interest with substantial applications for the conservation of germplasm.

The role of Cra in regulating acetate excretion and osmotic tolerance in E. coli K-12 and E. coli B at high density growth

PubMed Central

2011-01-01

Background E. coli B (BL21), unlike E.coli K-12 (JM109) is insensitive to glucose concentration and, therefore, grows faster and produces less acetate than E. coli K-12, especially when growing to high cell densities at high glucose concentration. By performing genomic analysis, it was demonstrated that the cause of this difference in sensitivity to the glucose concentration is the result of the differences in the central carbon metabolism activity. We hypothesized that the global transcription regulator Cra (FruR) is constitutively expressed in E. coli B and may be responsible for the different behaviour of the two strains. To investigate this possibility and better understand the function of Cra in the two strains, cra - negative E. coli B (BL21) and E. coli K-12 (JM109) were prepared and their growth behaviour and gene expression at high glucose were evaluated using microarray and real-time PCR. Results The deletion of the cra gene in E. coli B (BL21) minimally affected the growth and maximal acetate accumulation, while the deletion of the same gene in E.coli K-12 (JM109) caused the cells to stop growing as soon as acetate concentration reached 6.6 g/L and the media conductivity reached 21 mS/cm. ppsA (gluconeogenesis gene), aceBA (the glyoxylate shunt genes) and poxB (the acetate producing gene) were down-regulated in both strains, while acs (acetate uptake gene) was down-regulated only in E.coli B (BL21). These transcriptional differences had little effect on acetate and pyruvate production. Additionally, it was found that the lower growth of E. coli K-12 (JM109) strain was the result of transcription inhibition of the osmoprotectant producing bet operon (betABT). Conclusions The transcriptional changes caused by the deletion of cra gene did not affect the activity of the central carbon metabolism, suggesting that Cra does not act alone; rather it interacts with other pleiotropic regulators to create a network of metabolic effects. An unexpected outcome of this work is the finding that cra deletion caused transcription inhibition of the bet operon in E. coli K-12 (JM109) but did not affect this operon transcription in E. coli B (BL21). This property, together with the insensitivity to high glucose concentrations, makes this the E. coli B (BL21) strain more resistant to environmental changes. PMID:21718532

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.

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.

A new sol-gel processing routine without chelating agents for preparing highly transparent solutions and nanothin films: engineering the role of chemistry to design the process

NASA Astrophysics Data System (ADS)

Ashiri, Rouholah

2015-01-01

The great sensitivity of titanium alkoxides to hydrolysis makes their sol-gel transformation very fast and thus difficult to control. A method was proposed to alleviate this drawback. Preparation of highly transparent solutions and nanothin films is another objective of the present research. Employing nanoemulsion method and optimizing the processing conditions, a clear solution of well-dispersed nanosized particles was obtained. With the proposed process BaTiO3 precursor sols and nanothin films with enhanced optical transparency towards the visible were prepared. The optimal formulation of the sol consists of acetic acid, barium acetate, 2-propanol, TTIP and deionized water with 6:1:1:1:150 M ratios, respectively. It was found that the reduction of the temperature in the initial stage of mixing of precursors controls the size of the forming species and accordingly improves the stability and transparency of the sol. The results also showed that the applied modifications and optimizations significantly downsize the particles within the sol to the nanometric scale and accordingly result in a significant improvement in the optical response of the products.

Assessment of factors affecting micropropagation and ex vitro acclimatization of Nyctanthes arbor-tristis L.

PubMed

Jahan, Anushi Arjumend; Anis, M; Aref, I M

2011-03-01

Rapid differentiation of multiple shoots was observed in 94% of nodal explants of one year old Nyctanthes arbor-tristis L. plants. Shoot bud induction and multiplication took place on Murashige and Skoog (MS) medium supplemented with two cytokinins, i.e. Benzyladenine (BA) or Kinetin (Kn) either alone or in combination with different auxins, indole-3-butyric acid (IBA), indole-3-acetic acid (IAA) or α-naphthalene acetic acid (NAA). Between different media, pH levels and growth regulators tried, the optimum condition for maximum regenerative response was obtained on MS + Kn (2.5 μM) + N AA (0.5 μM) media at 5.8 pH, forming cultures with 23.26 ± 0.89 number of shoots and 6.36 ± 0.80 cm shoot length after 8 weeks of culture. Histological sections confirmed the formation of multiple buds from nodal explants. Rooting was achieved ex vitro by dipping the basal ends of microshoots in 200 μM IBA for 30 min followed by their transplantation in sterile soilrite. The plantlets with well-developed shoot and root system were successfully established in garden soil and grown outside in a greenhouse with a 80% survival rate.

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…

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.

Photoelectron Spectroscopy of Nitrogen Containing Molecules of Biological and Industrial Interest

NASA Astrophysics Data System (ADS)

Pinto, Rui Montenegro Val-do-Rio

The work presented herein is based on the gas-phase spectroscopic characterization of several molecules of high nitrogen content which are relevant to organic synthesis, industry and fundamental research on molecular physics. It is mainly an experimental enterprise on selected organic azides and tetrazoles, with heavy support on theoretical results from readily available computational methods. Part of the work relies on the design and construction of scientific apparatus, which substantially improve the existing equipment and extend the limits of the experiment. The electronic structure and gas-phase thermal decomposition of methyl 2-azidopropionate (M2AP, N3CH3CHCO2CH 3), benzyl azide (BA, C6H5CH2N 3), 2-, 3- and 4- methyl benzyl azide (2-, 3- and 4-MBA, CH3C 6H4CH2N3), 5-aminotetrazole (5ATZ, NH2CN4H), and 5-methyltetrazole (5MTZ, CH3CN 4H) are investigated through photoelectron spectroscopy, using either He(I) (21.22 eV) or synchrotron radiation in the Xray range. Relevant information obtained from mass spectrometry and matrix-isolation infrared spectroscopy is used to complement characterization of the samples. Regarding each molecules' thermal decomposition, pathways are proposed which account for the observed end products. Conformational analysis is performed, and the special case of annular tautomerism is addressed in the tetrazole compounds. High-temperature pyrolysis work is performed in collaboration with the University of Southampton, and XPS analysis using synchrotron radiation is performed at Elettra, the multidisciplinary synchrotron light laboratory in Trieste, Italy. Experimental findings are rationalized using different computational methods, based on post-Hartree-Fock approaches: many-body perturbation theory (MPn), configuration interaction (CI) and Green's function methods (OVGF, P3), as well as density functional theory (DFT), are used extensively to obtain optimized molecular geometries, ionization energies, orbital contours, relative energies, vibrational frequencies, and to assess possible pathways for thermal or electron impact fragmentation. Composite methods (G n and CBS) are used to estimate to kcal mol-1 accuracy the energy balance between reactants, transition structures and products in the overall decomposition process of the specified molecules.

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

Mehrabadi, Bahareh Alsadat Tavakoli; Dinh, Huyen N.; Bender, Guido

The performance loss and recovery of the fuel cell due to Balance of Plant (BOP) contaminants was identified via a combination of experimental data and a mathematical model. The experiments were designed to study the influence of organic contaminants (e.g. those from BOP materials) on the resistance of the catalyst, ionomer and membrane, and a mathematical model was developed that allowed us to separate these competing resistances from the data collected on an operating fuel cell. For this reason, based on the functional groups, four organic contaminants found in BOP materials, diethylene glycol monoethyl ether (DGMEE), diethylene glycol monoethyl ethermore » acetate (DGMEA), benzyl alcohol (BzOH) and 2,6-diaminotoluene (2,6-DAT) were infused separately to the cathode side of the fuel cell. The cell voltage and high frequency impedance resistance was measured as a function of time. The contaminant feed was then discontinued and voltage recovery was measured. It was determined that compounds with ion exchange properties like 2,6-DAT can cause voltage loss with non-reversible recovery, so this compound was studied in more detail. Finally, the degree of voltage loss increased with an increase in concentration, and/or infusion time, and increased with a decrease in catalyst loadings.« 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.

Difference in in vitro response and esculin content in two populations of Taraxacum officinale Weber.

PubMed

Jamshieed, Sumiya; Das, Sandip; Sharma, M P; Srivastava, P S

2010-12-01

In vitro micropropagation has been achieved in medicinally important plant, Taraxacum officinale collected from two different regions, Kashmir (J & K) and Garhwal (Uttarakhand). Leaf segments inoculated on MS supplemented with different combinations of Indole-3-acetic acid (IAA) and Benzyladenine (BA) produced indirect regeneration. For root induction MS fortified with Indole-3-butyric acid (IBA) was used. Taraxacum officinale collected from Garhwal responded two weeks earlier and showed shoot regeneration whereas in Kashmir population only callus proliferation occurred. Esculin content was also higher in the samples from Garhwal. The content was affected by both, the hormone concentration as well as age of the cultures. RAPD of the in vitro raised regenerants confirmed genetic stability.

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.

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

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

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.

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.

Carbocations from Oxidized Metabolites of Benzo[a]anthracene. A Computational Study of Their Methylated and Fluorinated Derivatives and Guanine Adducts

PubMed Central

Borosky, Gabriela L.; Laali, Kenneth K.

2008-01-01

Structure-reactivity relationships and substituent effects on carbocation stability in benzo[a] anthracene (BA) derivatives have been studied computationally at the B3LYP/6-31G* and MP2/6-31G** levels. Bay-region carbocations are formed by O-protonation of the 1,2-epoxides in barrierless processes. This process is energetically more favored as compared to carbocation generation via zwitterion formation/O-protonation, via single electron oxidation to generate a radical cation, or via benzylic hydroxylation. Relative carbocation stabilities were determined in the gas phase and in water as solvent (PCM method). Charge delocalization mode in the BA carbocation framework was deduced from NPA-derived changes in charges, and substitution by methyl or fluorine was studied at different positions selected on basis of the carbocation charge density. A bay-region methyl group produces structural distortion with consequent deviation from planarity of the aromatic system, which destabilizes the epoxide, favoring ring opening. Whereas fluorine substitution at sites bearing significant positive charge leads to carbocation stabilization by fluorine p-π back-bonding, a fluorine atom at a ring position which presented negative charge density leads to inductive destabilization. Methylated derivatives are less sensitive to substituent effects as compared to the fluorinated analogues. Although the solvent decreases the exothermicity of the epoxide ring opening reactions due to greater stabilization of the reactants, it provokes no changes in relative reactivities. Relative energies in the resulting bay-region carbocations are examined taking into account the available biological activity data on these compounds. In selected cases, quenching of bay-region carbocations was investigated by analyzing relative energies (in the gas phase and in water) and geometries of their guanine adducts formed via covalent bond formation with the exocyclic amino group and with the N-7. PMID:16841957

Gabaculine does not inhibit cytokinin-stimulated biosynthesis of chlorophyll in Pinus nigra seedlings in the dark.

PubMed

Drazic; Bogdanovic

2000-05-15

Chlorophyll (Chl) accumulation was monitored during black pine (Pinus nigra L.) seed germination for 14 days in the light and in the dark in the presence of gabaculine (GAB) and cytokinin in order to elucidate the regulation of gymnosperm seedling greening in the dark, primarily at the level of aminolevulinic acid formation. In the light, GAB inhibited chlorophyll accumulation in a manner dependent on concentration and developmental stage, and in the dark it showed no effect. Cytokinin, 10(-5) M benzyl adenine (BA) partly overcame GAB-induced inhibition in the light, mainly during earlier developmental stages. In the seedlings grown in the dark, an equal quantity of Chl accumulated in the presence of cytokinin with and without GAB and it was approximately 20-40% higher than in the control seedlings or in the seedlings grown only in the presence of GAB. 5-Amino-levulinic acid (ALA) synthesis was equal in the light and in the dark in seedlings of the same age and seedlings treated with GAB grown in the dark. In the light, GAB inhibited ALA synthetic activity. The results indicate that ALA synthesis is not a rate-limiting step within Chl biosynthesis in pine seedlings grown in the dark.

Micropropagation of Hedychium coronarium J. Koenig through rhizome bud.

PubMed

Mohanty, Pritam; Behera, Shashikanta; Swain, Swasti S; Barik, Durga P; Naik, Soumendra K

2013-10-01

An optimized protocol was developed for in vitro plant regeneration of a medicinally important herb Hedychium coronarium J. Koenig using sprouted buds of rhizomes. The rhizomes with sprouted bud were inoculated on Murashige and Skoog (Physiol Plant 15:473-497, 1962) medium (MS) supplemented with either N(6)-benzyladenine (BA) alone (1.0-4.0 mg L(-1)) or in combination with 0.5 mg L(-1) naphthalene acetic acid (NAA). Of these combinations, MS supplemented with a combination of 2.0 mg L(-1) BA and 0.5 mg L(-1) NAA was most effective. In this medium, best shoots (3.6) and roots (4.0) regeneration was observed simultaneously with an average shoot and root length of 4.7 cm and 4.2 cm respectively. Regeneration of shoots and roots in the same medium at the same time (One step shoot and root regeneration) reduced the time for production of in vitro plantlets and eliminates the media cost of rooting. Cent-percent (100 %) success in plant establishment was observed in both gradual acclimatization process as well as when plants were directly transferred to outdoor in clay pots containing a mixture of garden soil and sand (2:1) without any sequential acclimatization stage.

Elongation growth of the leaf sheath base of Avena sativa seedlings: regulation by hormones and sucrose

NASA Technical Reports Server (NTRS)

Brock, T. G.; Kaufman, P. B.

1991-01-01

The leaf sheath base of the seedling of Avena sativa was characterized for growth response to hormones and sucrose. Six day old plants, raised under a 10:14 hr light:dark cycle, were excised at the coleoptilar node and 1 cm above the node for treatment. The growth of the leaf sheath base was promoted by gibberellic acid (GA3) and this response was dose dependent. The lag to response initiation was approximately 4 hr. Growth with or without GA3 (10 micromoles) was transient, diminishing appreciably after 48 hr. The addition of 10 mM sucrose greatly prolonged growth; the effect of GA3 and sucrose was additive. Neither indole-3-acetic acid (IAA) nor the cytokinin N6-benzyladenine (BA), alone or in combination, promoted the growth of leaf sheath bases. However, both significantly inhibited the action of GA3. The inhibitory effect of IAA was dose dependent and was not affected by the addition of BA or sucrose. These results indicate that the growth of leaf sheath bases of Avena sativa is promoted specifically by gibberellin, that this action depends on the availability of carbohydrates from outside of the leaf sheath base, and that the promotional effect of GA3 can be modified by either auxins or cytokinins.

Functional electrospun nanofibers for multimodal sensitive detection of biogenic amines in food via a simple dipstick assay.

PubMed

Yurova, Nadezhda S; Danchuk, Alexandra; Mobarez, Sarah N; Wongkaew, Nongnoot; Rusanova, Tatiana; Baeumner, Antje J; Duerkop, Axel

2018-01-01

Electrospun nanofibers (ENFs) are promising materials for rapid diagnostic tests like lateral flow assays and dipsticks because they offer an immense surface area while excluding minimal volume, a variety of functional surface groups, and can entrap functional additives within their interior. Here, we show that ENFs on sample pads are superior in comparison to standard polymer membranes for the optical detection of biogenic amines (BAs) in food using a dipstick format. Specifically, cellulose acetate (CA) fibers doped with 2 mg/mL of the chromogenic and fluorogenic amine-reactive chameleon dye Py-1 were electrospun into uniform anionic mats. Those extract cationic BAs from real samples and Py-1 transduces BA concentrations into a change of color, reflectance, and fluorescence. Dropping a BA sample onto the nanofiber mat converts the weakly fluorescent pyrylium dye Py-1 into a strongly red emitting pyridinium dye. For the first time, a simple UV lamp excites fluorescence and a digital camera acts as detector. The intensity ratio of the red to the blue channel of the digital image is dependent on the concentration of most relevant BAs indicating food spoilage from 10 to 250 μM. This matches the permitted limits for BAs in foods and no false positive signals arise from secondary and tertiary amines. BA detection in seafood samples was also demonstrated successfully. The nanofiber mat dipsticks were up to sixfold more sensitive than those using a polymer membrane with the same dye embedded. Hence, nanofiber-based tests are not only superior to polymer-based dipstick assays, but will also improve the performance of established tests related to food safety, medical diagnostics, and environmental testing. Graphical Absract ᅟ.

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.

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.

Optimized conditions for chelation of yttrium-90-DOTA immunoconjugates.

PubMed

Kukis, D L; DeNardo, S J; DeNardo, G L; O'Donnell, R T; Meares, C F

1998-12-01

Radioimmunotherapy (RIT) with 90Y-labeled immunoconjugates has shown promise in clinical trials. The macrocyclic chelating agent 1,4,7,10-tetraazacyclododecane-N,N',N",N"'-tetraacetic acid (DOTA) binds 90Y with extraordinary stability, minimizing the toxicity of 90Y-DOTA immunoconjugates arising from loss of 90Y to bone. However, reported 90Y-DOTA immunoconjugate product yields have been typically only < or =50%. Improved yields are needed for RIT with 90Y-DOTA immunoconjugates to be practical. (S) 2-[p-(bromoacetamido)benzyl]-DOTA (BAD) was conjugated to the monoclonal antibody Lym-1 via 2-iminothiolane (2IT). The immunoconjugate product, 2IT-BAD-Lym-1, was labeled in excess yttrium in various buffers over a range of concentrations and pH. Kinetic studies were performed in selected buffers to estimate radiolabeling reaction times under prospective radiopharmacy labeling conditions. The effect of temperature on reaction kinetics was examined. Optimal radiolabeling conditions were identified and used in eight radiolabeling experiments with 2IT-BAD-Lym-1 and a second immunoconjugate, DOTA-peptide-chimeric L6, with 248-492 MBq (6.7-13.3 mCi) of 90Y. Ammonium acetate buffer (0.5 M) was associated with the highest uptake of yttrium. On the basis of kinetic data, the time required to chelate 94% of 90Y (four half-times) under prospective radiopharmacy labeling conditions in 0.5 M ammonium acetate was 17-148 min at pH 6.5, but it was only 1-10 min at pH 7.5. Raising the reaction temperature from 25 degrees C to 37 degrees C markedly increased the chelation rate. Optimal radiolabeling conditions were identified as: 30-min reaction time, 0.5 M ammonium acetate buffer, pH 7-7.5 and 37 degrees C. In eight labeling experiments under optimal conditions, a mean product yield (+/- s.d.) of 91%+/-8% was achieved, comparable to iodination yields. The specific activity of final products was 74-130 MBq (2.0-3.5 mCi) of 90Y per mg of monoclonal antibody. The immunoreactivity of 90Y-labeled immunoconjugates was 100%+/-11%. The optimization of 90Y-DOTA chelation conditions represents an important advance in 90Y RIT because it facilitates the dependable and cost-effective preparation of 90Y-DOTA pharmaceuticals.

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

Plant growth regulators induced urease activity in Cucurbita pepo L. cotyledons.

PubMed

El Shora, Hamed M; Ali, Awatif S

2016-03-01

This study is aimed to investigate the activity of urease (EC 3.5.1.5, urea amidohydrolase) that catalyzes the hydrolysis of urea in 5-day-old Cucurbita pepo cotyledons subjected to various concentrations of different growth regulators. The treatment of C. pepo cotyledons with different concentrations (100-600 μmol) of different auxins [indole-3-acetic acid (IAA), indole butyric acid (IBA), indole propionic acid (IPA) and naphthalene acetic acid (NAA)]; or with different concentrations (100-300 μmol) of different cytokinins [kinetin, zeatin and benzyladenine (6-BA)] resulted in a significant increase of urease activity, compared to control. The optimal effects were recorded for each of 500 μmol of IAA and 300 μmol of zeatin treatments. A gradual increase in urease activity was detected in cotyledons treated with various concentrations (0.2-1.0 mM) of 28-homobrassinolide (HBL), in relative to control. A substantial increase in urease activity was observed in cotyledons subjected to different concentrations of triazole (10-60 mg L(-1)), containing either triadimefon (TDM) or hexaconazole (HEX), compared to control. The combination of 300 μmol zeatin with any of protein inhibitors, namely 5-fluorouridine (FUrd), cordycepin and α-amanitin, resulted in the alleviation of their inhibitory effect on the urease activity.

A simplified soil extraction sequence to monitor the main and trace element speciation in soil after compost and mineral fertilizer additions upon the composition of wheat grains

NASA Astrophysics Data System (ADS)

Sager, Manfred; Erhart, Eva

2016-04-01

High quality biological waste treatment aims at producing compost in order to maintain a clean environment and to sustain soil organic carbon levels. Fertilization with compost as a source of organic carbon, nutrients, and accessory elements, as well as fertilization with mineral N- and PK fertilizer have been tested in a field experiment on a calcaric Fluvisol in the Danube wetlands, at 4 levels each. Yields of wheat were recorded, and grains and soils were sampled from each treatment, and analyzed for main and trace element composition. The corresponding soils were characterized by mobile phases, obtained by leaching with 0,16M acetic acid to cover exchangeables plus carbonates, and subsequently by 0,1M oxalate buffer pH 3 to dissolve the pedogenic oxides. Total amounts were obtained from digests with perchloric- nitric-hydrofluoric acid. For quasi-total amounts, aqua regia was replaced by pressure decomposition with KClO3 in dilute nitric acid. The proposed extraction sequence permits to analyze and interpret soil for main elements, trace elements, nutrients and anions simultaneously. Factor analyses of soil extracts obtained from dilute acetic acid revealed Ba-Be-Cd-Cu-Li-S (traces), Ca-Mg-Mn (main carbonates), Al-Fe-B, Y, and P-K (nutrients) as chemically feasible principal components. Subsequent soil extracts from oxalate contained Al-B-Co-K-Na-Pb-Si-V-S (maybe acid silicate weathering), Cr-Li-Ni-Sr-Ti (maybe basic silicate weathering), Be-Cu-Fe-P, Co-Mg-Mn-Zn (Mn-oxides) and Ba-Sc as principal components. Factor analyses of total element data distinguished the principal components Ce-La-Li-Sc-Y-P (rare earths), Al-Ca-Fe-K-Mg-Na-P (main elements), Cd-Co-Cr-Cu-Ni-Zn (trace elements), As-Pb (contaminants), Ba-Mn-Sr, and Ti, which looks chemically feasible also. Factor analyses of those soil fractions which presumably form the main fractions of exchangeables, carbonates, pedogenic oxides and silicates, showed no cross connections, except for P. Oxalate-soluble Fe together with P and S was independent from oxalate-soluble Al-Mn-Si. In the crops, all element levels were within a non-contaminated and non-deficient range, therefore correlations with concentrations as well as loads in the wheat grains where largely not pronounced. Maximum correlations between plant and soil data were obtained with Li and Be. The load data (concentration times yield, given in g/ha) were much more intercorrelated than the concentrations. Regarding the same element, correlation coefficients between loads and respective concentrations were larger than 0,800 for Al, Ba, Cd, Co, Cr, Li, Mo, Na, Ni, Se, and Sr, which means the transfer remained independent from the load. In case of Ca, Mg, P, S, Zn, however, correlation coefficients between loads and concentrations were < 0,500, thus the transfer was not constant because of obvious metabolic influences. The proposed method of soil characterization was applied at a field trial here for the first time, and offers new possibilities of intercorrelations between plant uptake and geochemical soil fractions.

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).

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.

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.

The effect of tissue structure and soil chemistry on trace element uptake in fossils

NASA Astrophysics Data System (ADS)

Hinz, Emily A.; Kohn, Matthew J.

2010-06-01

Trace element profiles for common divalent cations (Sr, Zn, Ba), rare-earth elements (REE), Y, U, and Th were measured in fossil bones and teeth from the c. 25 ka Merrell locality, Montana, USA, by using laser-ablation ICP-MS. Multiple traverses in teeth were transformed into 2-D trace element maps for visualizing structural influences on trace element uptake. Trace element compositions of different soils from the fossil site were also analyzed by solution ICP-MS, employing progressive leaches that included distilled H 2O, 0.1 M acetic acid, and microwave digestion in concentrated HCl-HNO 3. In teeth, trace element uptake in enamel is 2-4 orders of magnitude slower than in dentine, forming an effective trace element barrier. Uptake in dentine parallel to the dentine-enamel interface is enhanced by at least 2 orders of magnitude compared to transverse, causing trace element "plumes" down the tooth core. In bone, U, Ba and Sr are nearly homogeneous, implying diffusivities ˜5 orders of magnitude faster than in enamel and virtually complete equilibration with host soils. In contrast all REE show strong depletions inward, with stepwise linear segments in log-normal or inverse complementary error function plots; these data require a multi-medium diffusion model, with about 2 orders of magnitude difference in slowest vs. fastest diffusivities. Differences in REE diffusivities in bone (slow) vs. dentine (fast) reflect different partition coefficients ( Kd's). Although acid leaches and bulk digestion of soils yield comparable fossil-soil Kd's among different elements, natural solutions are expected to be neutral to slightly basic. Distilled H 2O leachates instead reveal radically different Kd's in bone for REE than for U-Sr-Ba, suggest orders of magnitude lower effective diffusivities for REE, and readily explain steep vs. flat profiles for REE vs. U-Sr-Ba, respectively. Differences among REE Kd's and diffusivities may explain inward changes in Ce anomalies. Acid washes and bulk soil compositions yield misleading Kd's for many trace elements, especially the REE, and H 2O-leaches are preferred. Patterns of trace element distributions indicate diagenetic alteration at all scales, including enamel, and challenge the use of trace elements in paleodietary studies.

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

Volatiles Emitted at Different Flowering Stages of Jasminum sambac and Expression of Genes Related to α-Farnesene Biosynthesis.

PubMed

Yu, Ying; Lyu, Shiheng; Chen, Dan; Lin, Yi; Chen, Jianjun; Chen, Guixin; Ye, Naixing

2017-03-29

Fresh jasmine flowers have been used to make jasmine teas in China, but there has been no complete information about volatile organic compound emissions in relation to flower developmental stages and no science-based knowledge about which floral stage should be used for the infusion. This study monitored volatile organic compounds emitted from living flowers of Jasminum sambac (L.) Ait. 'Bifoliatum' at five developmental stages and also from excised flowers. Among the compounds identified, α-farnesene, linalool, and benzyl acetate were most abundant. Since α-farnesene is synthesized through the Mevalonate pathway, four genes encoding 3-hydroxy-3-methylglutaryl coenzyme A synthase, 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGR), farnesyl pyrophosphate synthase, and terpene synthase were isolated. Their expression patterns in living flowers at the five stages and in excised flowers coincided with the emission patterns of α-farnesene. Application of lovastatin, a HMGR inhibitor, significantly reduced the expression of the genes and greatly decreased the emission of α-farnesene. The sweet scent was diminished from lovastatin-treated flowers as well. These results indicate that α-farnesene is an important compound emitted from jasmine flowers, and its emission patterns suggest that flowers at the opening stage or flower buds 8 h after excision should be used for the infusion of tea leaves.

An Efficient Extraction Method for Fragrant Volatiles from Jasminum sambac (L.) Ait.

PubMed

Ye, Qiuping; Jin, Xinyi; Zhu, Xinliang; Lin, Tongxiang; Hao, Zhilong; Yang, Qian

2015-01-01

The sweet smell of aroma of Jasminum sambac (L.) Ait. is releasing while the flowers are blooming. Although components of volatile oil have been extensively studied, there are problematic issues, such as low efficiency of yield, flavour distortion. Here, the subcritical fluid extraction (SFE) was performed to extract fragrant volatiles from activated carbon that had absorbed the aroma of jasmine flowers. This novel method could effectively obtain main aromatic compounds with quality significantly better than solvent extraction (SE). Based on the analysis data with response surface methodology (RSM), we optimized the extraction conditions which consisted of a temperature of 44°C, a solvent-to-material ratio of 3.5:1, and an extraction time of 53 min. Under these conditions, the extraction yield was 4.91%. Furthermore, the key jasmine essence oil components, benzyl acetate and linalool, increase 7 fold and 2 fold respectively which lead to strong typical smell of the jasmine oil. The new method can reduce spicy components which lead to the essential oils smelling sweeter. Thus, the quality of the jasmine essence oil was dramatically improved and yields based on the key component increased dramatically. Our results provide a new effective technique for extracting fragrant volatiles from jasmine flowers.

Effect of System Contaminants on the Performance of a Proton Exchange Membrane Fuel Cell

DOE PAGES

Mehrabadi, Bahareh Alsadat Tavakoli; Dinh, Huyen N.; Bender, Guido; ...

2016-11-10

The performance loss and recovery of the fuel cell due to Balance of Plant (BOP) contaminants was identified via a combination of experimental data and a mathematical model. The experiments were designed to study the influence of organic contaminants (e.g. those from BOP materials) on the resistance of the catalyst, ionomer and membrane, and a mathematical model was developed that allowed us to separate these competing resistances from the data collected on an operating fuel cell. For this reason, based on the functional groups, four organic contaminants found in BOP materials, diethylene glycol monoethyl ether (DGMEE), diethylene glycol monoethyl ethermore » acetate (DGMEA), benzyl alcohol (BzOH) and 2,6-diaminotoluene (2,6-DAT) were infused separately to the cathode side of the fuel cell. The cell voltage and high frequency impedance resistance was measured as a function of time. The contaminant feed was then discontinued and voltage recovery was measured. It was determined that compounds with ion exchange properties like 2,6-DAT can cause voltage loss with non-reversible recovery, so this compound was studied in more detail. Finally, the degree of voltage loss increased with an increase in concentration, and/or infusion time, and increased with a decrease in catalyst loadings.« less

Analysis of hydroquinone and some of its ethers by using capillary electrochromatography.

PubMed

Desiderio, C; Ossicini, L; Fanali, S

2000-07-28

Capillary electrochromatography (CEC) was used for the analysis of relevant compounds in cosmetic preparation. Hydroquinone (HQ) and some of its ethers (methyl-, dimethyl-, benzyl-, phenyl-, propyl-HQ derivatives) were analyzed by using an octadecylsilica (ODS) stationary phase packed in fused-silica capillary (100 microm I.D.; 30 cm and 21.5 cm total and effective lengths, respectively). 20 mM Ammonium acetate pH 6-acetonitrile (50-70%) were the mobile phases used for the experiments. The acetonitrile (ACN) content strongly influenced the resolution of the studied compounds as well as the efficiency and the retention factor. Baseline resolution for the studied analytes was achieved at both the lowest and the highest percentage of ACN, the last one providing the shortest analysis time. Mobile phase containing 70% of ACN was therefore used for the analysis of an extract of skin-toning cream declared to contain HQ. Good repeatability of both retention times, peak areas and peak areas ratio (Asample/Ainternational standard) was found. The calibration graphs were linear in the concentration range studied (5-90 microg/ml) with correlation coefficients between 0.9975 and 09991. The analysis of the cosmetic preparation revealed the presence of HQ (1.72%, w/w) and of two additional peaks (not identified).

The effect of tomato juices and bean sprout extracts on vitro shoot regeneration of Physalis angulata L.

NASA Astrophysics Data System (ADS)

Mastuti, Retno; Munawarti, Aminatun; Rosyidah, Mufidatur

2017-11-01

Physalis angulata L. (Ciplukan) which belongs to Solanaceae is an important medicinal plant. In vitro culture medium contains carbon source, inorganic substance, vitamins, and plant growth regulators. However, organic growth supplements have frequently been added to improve regeneration capability of explants. This study was conducted to observe the effect of tomato juices and extract bean sprout on shoot regeneration and multiplication of in vitro nodal explants. The explants were cultured on MS basal medium + 6-benzyl amino purine (BAP) 2 mg/L + indole-3-acetic acid (IAA) 0.05 mg/L with and without organic supplements. Tomato juices (T) 5, 7.5 and 10% or bean sprout extract (B) 1.25, 2.5, and 3.75% were added as natural organic supplements. Almost all explants have produced shoots one week after culture. After six weeks of culture maximum shoot number (12.5±3.9) was produced in medium MS + T5 while maximum shoot length (10.7 ± 0.7 cm) was obtained in medium MS + T 7.5. Medium T tends to produce more shoots than the medium B and medium control. This result indicates the potential of natural organic supplements for supporting Ciplukan propagation through in vitro culture.

Optimising resolution for a preparative separation of Chinese herbal medicine using a surrogate model sample system.

PubMed

Ye, Haoyu; Ignatova, Svetlana; Peng, Aihua; Chen, Lijuan; Sutherland, Ian

2009-06-26

This paper builds on previous modelling research with short single layer columns to develop rapid methods for optimising high-performance counter-current chromatography at constant stationary phase retention. Benzyl alcohol and p-cresol are used as model compounds to rapidly optimise first flow and then rotational speed operating conditions at a preparative scale with long columns for a given phase system using a Dynamic Extractions Midi-DE centrifuge. The transfer to a high value extract such as the crude ethanol extract of Chinese herbal medicine Millettia pachycarpa Benth. is then demonstrated and validated using the same phase system. The results show that constant stationary phase modelling of flow and speed with long multilayer columns works well as a cheap, quick and effective method of optimising operating conditions for the chosen phase system-hexane-ethyl acetate-methanol-water (1:0.8:1:0.6, v/v). Optimum conditions for resolution were a flow of 20 ml/min and speed of 1200 rpm, but for throughput were 80 ml/min at the same speed. The results show that 80 ml/min gave the best throughputs for tephrosin (518 mg/h), pyranoisoflavone (47.2 mg/h) and dehydrodeguelin (10.4 mg/h), whereas for deguelin (100.5 mg/h), the best flow rate was 40 ml/min.

Toxic effects of two essential oils and their constituents on the mealworm beetle, Tenebrio molitor.

PubMed

Martínez, L C; Plata-Rueda, A; Colares, H C; Campos, J M; Dos Santos, M H; Fernandes, F L; Serrão, J E; Zanuncio, J C

2017-12-14

The study identified insecticidal effects from the cinnamon and clove essential oils in Tenebrio molitor L. (Coleoptera: Tenebrionidae). The lethal concentrations (LC50 and LC90), lethal time, and repellent effect on larvae, pupae, and adults of T. molitor after exposure to six concentrations of each essential oil and toxic compounds were evaluated. The chemical composition of the cinnamon oil was also determined and primary compounds were eugenol (10.19%), trans-3-caren-2-ol (9.92%), benzyl benzoate (9.68%), caryophyllene (9.05%), eugenyl acetate (7.47%), α-phellandrene (7.18%), and α-pinene (6.92%). In clove essential oil, the primary compounds were eugenol (26.64%), caryophyllene (23.73%), caryophyllene oxide (17.74%), 2-propenoic acid (11.84%), α-humulene (10.48%), γ-cadinene (4.85%), and humulene oxide (4.69%). Cinnamon and clove essential oils were toxic to T. molitor. In toxic chemical compounds, eugenol have stronger contact toxicity in larvae, pupae, and adult than caryophyllene oxide, followed by α-pinene, α-phellandrene, and α-humulene. In general, the two essential oils were toxic and repellent to adult T. molitor. Cinnamon and clove essential oils and their compounds caused higher mortality and repellency on T. molitor and, therefore, have the potential for integrated management programs of this insect.

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.

Lignin-carbohydrate complexes from sisal (Agave sisalana) and abaca (Musa textilis): chemical composition and structural modifications during the isolation process.

PubMed

Del Río, José C; Prinsen, Pepijn; Cadena, Edith M; Martínez, Ángel T; Gutiérrez, Ana; Rencoret, Jorge

2016-05-01

Two types of lignins occurred in different lignin-carbohydrate fractions, a lignin enriched in syringyl units, less condensed, preferentially associated with xylans, and a lignin with more guaiacyl units, more condensed, associated with glucans. Lignin-carbohydrate complexes (LCC) were isolated from the fibers of sisal (Agave sisalana) and abaca (Musa textilis) according to a plant biomass fractionation procedure recently developed and which was termed as "universally" applicable to any type of lignocellulosic material. Two LCC fractions, namely glucan-lignin (GL) and xylan-lignin (XL), were isolated and differed in the content and composition of carbohydrates and lignin. In both cases, GL fractions were enriched in glucans and comparatively depleted in lignin, whereas XL fractions were depleted in glucans, but enriched in xylans and lignin. Analysis by two-dimensional Nuclear Magnetic Resonance (2D-NMR) and Derivatization Followed by Reductive Cleavage (DFRC) indicated that the XL fractions were enriched in syringyl (S)-lignin units and β-O-4' alkyl-aryl ether linkages, whereas GL fractions have more guaiacyl (G)-lignin units and less β-O-4' alkyl-aryl ether linkages per lignin unit. The data suggest that the structural characteristics of the lignin polymers are not homogeneously distributed within the same plant and that two different lignin polymers with different composition and structure might be present. The analyses also suggested that acetates from hemicelluloses and the acyl groups (acetates and p-coumarates) attached to the γ-OH of the lignin side chains were extensively hydrolyzed and removed during the LCC fractionation process. Therefore, caution must be paid when using this fractionation approach for the structural characterization of plants with acylated hemicelluloses and lignins. Finally, several chemical linkages (phenylglycosides and benzyl ethers) could be observed to occur between lignin and xylans in these plants.

Interactive Effects of Growth Regulators, Carbon Sources, pH on Plant Regeneration and Assessment of Genetic Fidelity Using Single Primer Amplification Reaction (SPARS) Techniques in Withania somnifera L.

PubMed

Fatima, Nigar; Ahmad, Naseem; Ahmad, Iqbal; Anis, Mohammad

2015-09-01

An improved and methodical in vitro shoot morphogenic approach through axillary bud multiplication was established in a drug yielding plant, Withania somnifera L. Effects of plant growth regulators [6-benzyladenine (BA), kinetin (Kin), 2-isopentenyladenine (2iP), and thidiazuron (TDZ)] either singly or in combination with α-napthalene acetic acid (NAA), indole-3-butyric acid (IBA), and indole-3-acetic acid (IAA) in Murashige and Skoog (MS) medium were tested. The highest regeneration frequency (90 %) with optimum number of shoots (32 ± 0.00)/explant were obtained on MS medium fortified with 2.5 μM 6-benzyladenine (BA) and 0.5 μM NAA and 30 g/l sucrose at pH 5.8. Among the tried TDZ concentrations, 0.5 μM resulted in maximum number of shoots (20.4 ± 0.40)/explant after 4 weeks of exposure. The proliferating shoot cultures established by repeated subculturing of the mother explants on the hormone-free medium produced the highest shoot number (29.4 ± 0.40) with shoot length (6.80 ± 0.12 cm)/explant at fourth subculture passage, which a decline in shoot proliferation was recorded. Different concentrations of NAA were tested for ex vitro rooting of microshoots. The maximum percentage of rooting 100 % with maximum roots (18.3 ± 0.1) was achieved in soilrite when basal portion of the microshoots were treated with 200 μM (NAA) for 15 min per shoot. The plantlets went through hardening phase in a growth chamber, prior to ex vitro transfer. The PCR-based single primer amplification reaction (SPAR) methods which include random amplified polymorphic DNA (RAPD) and direct amplification of minisatellite DNA (DAMD) markers has been used for assessment of genetic stability of micropropagated plantlets. No variation was observed in DNA fingerprinting patterns among the micropropagated and the donor plants illustrating their genetic uniformity.

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.

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.

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.

A comparison of the extraction procedures and quantification methods for the chromatographic determination of polycyclic aromatic hydrocarbons in charcoal grilled meat and fish.

PubMed

Viegas, O; Novo, P; Pinho, O; Ferreira, I M P L V O

2012-01-15

A method for analysis of 15 PAHs in charcoal-grilled meat/fish was established by high performance liquid chromatography and fluorescence detection. Gradient elution was performed with methanol/water/ethyl acetate. Maxima excitation and emission wavelengths were selected for each PAH. Retention times were very stable with coefficients of variation below 0.24% within analytical day and below 0.60% across analytical days. Two different methods of cleanup and pre-concentration steps were compared. Solvent extraction assisted by sonication carried out with n-hexane on 2g of lyophilized meat or 1g of lyophilized fish allowed to obtain high sensitivity, reproducibility and better extraction efficiency. Limits of quantification (LOQs, s/n=10) were lower than 0.01ng/g of meat wet weight and lower than 0.02ng/g of fish wet weight for all PAHs (except for Na, Fl and IP that were lower than 0.1ng/g). Two different quantification methods were compared. Standard addition method compensated PAHs losses due to incomplete extraction and it is recommended for analyses of grilled meat and fish samples that usually contain very low amounts of the eight high molecular weight PAHs (BaA, Ch, BbF, BkF, BaP, IP, BgP, DhA). Copyright © 2011 Elsevier B.V. All rights reserved.

Sustainable remediation: electrochemically assisted microbial dechlorination of tetrachloroethene-contaminated groundwater.

PubMed

Patil, Sayali S; Adetutu, Eric M; Rochow, Jacqueline; Mitchell, James G; Ball, Andrew S

2014-01-01

Microbial electric systems (MESs) hold significant promise for the sustainable remediation of chlorinated solvents such as tetrachlorethene (perchloroethylene, PCE). Although the bio-electrochemical potential of some specific bacterial species such as Dehalcoccoides and Geobacteraceae have been exploited, this ability in other undefined microorganisms has not been extensively assessed. Hence, the focus of this study was to investigate indigenous and potentially bio-electrochemically active microorganisms in PCE-contaminated groundwater. Lab-scale MESs were fed with acetate and carbon electrode/PCE as electron donors and acceptors, respectively, under biostimulation (BS) and BS-bioaugmentation (BS-BA) regimes. Molecular analysis of the indigenous groundwater community identified mainly Spirochaetes, Firmicutes, Bacteroidetes, and γ and δ-Proteobacteria. Environmental scanning electron photomicrographs of the anode surfaces showed extensive indigenous microbial colonization under both regimes. This colonization and BS resulted in 100% dechlorination in both treatments with complete dechlorination occurring 4 weeks earlier in BS-BA samples and up to 11.5 μA of current being generated. The indigenous non-Dehalococcoides community was found to contribute significantly to electron transfer with ∼61% of the current generated due to their activities. This study therefore shows the potential of the indigenous non-Dehalococcoides bacterial community in bio-electrochemically reducing PCE that could prove to be a cost-effective and sustainable bioremediation practice. © 2013 The Authors. Microbial Biotechnology published by John Wiley & Sons Ltd and Society for Applied Microbiology.

Spray drying from organic solvents to prepare nanoporous/nanoparticulate microparticles of protein: excipient composites designed for oral inhalation.

PubMed

Ní Ógáin, Orla; Tajber, Lidia; Corrigan, Owen I; Healy, Anne Marie

2012-09-01

The aim of this study was to determine if spray-drying could successfully produce microparticles containing the model protein trypsin in a form suitable for inhalation. Trypsin was spray-dried with raffinose from a methanol : n-butyl acetate solvent system (MeOH : BA). The solvent system was then adjusted to include water, and trypsin was co-spray-dried with raffinose, trehalose or hydroxpropyl-β-cyclodextrin. The spray-dried products were characterised by SEM, XRD, DSC, TGA and FTIR. Protein biological activity and in-vitro deposition of trypsin : excipient nanoporous/nanoparticulate microparticles (NPMPs) was also assessed. The inclusion of water in a MeOH : BA solvent system allowed for the successful production of NPMPs of trypsin : excipient by spray-drying. Trypsin formulated as trypsin : excipient NPMPs retained biological activity on processing and showed no deterioration in activity or morphological characteristics when stored with desiccant at either 4 or 25°C. Hydroxpropyl-β-cyclodextrin showed advantages over the sugars in terms of producing powders with appropriate density and with greater physical stability under high-humidity conditions. Fine particle fractions of between 41 and 45% were determined for trypsin : excipient NPMPs. NPMPs of trypsin : excipient systems can be produced by spray-drying by adjustment of the solvent system to allow for adequate solubility of trypsin. © 2012 The Authors. JPP © 2012 Royal Pharmaceutical Society.

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.

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.

Full evaporation headspace gas chromatography for sensitive determination of high boiling point volatile organic compounds in low boiling matrices.

PubMed

Mana Kialengila, Didi; Wolfs, Kris; Bugalama, John; Van Schepdael, Ann; Adams, Erwin

2013-11-08

Determination of volatile organic components (VOC's) is often done by static headspace gas chromatography as this technique is very robust and combines easy sample preparation with good selectivity and low detection limits. This technique is used nowadays in different applications which have in common that they have a dirty matrix which would be problematic in direct injection approaches. Headspace by nature favors the most volatile compounds, avoiding the less volatile to reach the injector and column. As a consequence, determination of a high boiling solvent in a lower boiling matrix becomes challenging. Determination of VOCs like: xylenes, cumene, N,N-dimethylformamide (DMF), dimethyl sulfoxide (DMSO), N,N-dimethylacetamide (DMA), N-methyl-2-pyrrolidone (NMP), 1,3-dimethyl-2-imidazolidinone (DMI), benzyl alcohol (BA) and anisole in water or water soluble products are an interesting example of the arising problems. In this work, a headspace variant called full evaporation technique is worked out and validated for the mentioned solvents. Detection limits below 0.1 μg/vial are reached with RSD values below 10%. Mean recovery values ranged from 92.5 to 110%. The optimized method was applied to determine residual DMSO in a water based cell culture and DMSO and DMA in tetracycline hydrochloride (a water soluble sample). Copyright © 2013 Elsevier B.V. All rights reserved.

Enhanced NO2 abatement by alkaline-earth modified g-C3N4 nanocomposites for efficient air purification

NASA Astrophysics Data System (ADS)

Papailias, Ilias; Todorova, Nadia; Giannakopoulou, Tatiana; Karapati, Sofia; Boukos, Nikos; Dimotikali, Dimitra; Trapalis, Christos

2018-02-01

The emission of nitrogen dioxide (NO2) is a major problem encountered in photocatalytic NOx removal for air purification. Although the oxidation of nitric oxide (NO) has been extensively studied, the elimination of NO2 byproduct is still in preliminary stage. In this work, alkaline-earth modified graphitic carbon nitride (g-C3N4) is proposed for efficient NOx removal by minimizing the emission of NO2 during the NO oxidation process. The novel photocatalysts were synthesized by annealing mixtures of melamine and various alkaline-earth acetates (magnesium, calcium and barium acetate) at 550 °C for 3 h. The specific surface area of the photocatalysts varied between 4.65 and 11.81 m2/g. The formation of MgO, CaCO3 and BaCO3 was demonstrated by XPS and FT-IR analyses. The initial concentration of each alkaline-earth precursor was 5 and 10 wt%, while the final metal concentration in the nanocomposites was in the range of 7.19-22.39 wt%. The modified photocatalysts showed slightly reduced NO oxidation ability. However, the overall air quality was significantly improved by restraining the NO2 emission. The results were related to the basic character of the nanocomposites due to the presence of alkaline-earths and their enhanced NO2 adsorption capability.

[Separation and determination of eight plant hormones by reversed-phase high performance liquid chromatography].

PubMed

Fang, N; Hou, S; Shao, X; He, Y; Zhao, G

1998-09-01

In this paper, reversed-phase high performance liquid chromatographic technique was used for the separation and determination of eight plant hormones. Methanol-water-acetic acid system was chosen as the mobile phase. The effects of different separation conditions, such as the methanol and acetic acid concentrations in mobile phase, on the retention behaviours of eight plant hormones in this system were studied. The general trends in retention behaviours could be correlated to the methanol concentration in mobile phase. The experimental results showed that the optimum separation was achieved with following gradient elution condition: 0-3 minutes, 70% (water percentage in mobile phase), 3-13 minutes, 70%-20%, 13-48 minutes, 20%. Benzene was added to be as the internal standard. Under this experimental condition, the eight plant hormones could be separated completely and detected quantitatively at 260 nm within 16 minutes. The calibration curves for the eight compounds gave linearity over a wide range. The correlation coefficients of each components were r(ZT) = 0.9971, r(GAs) = 0.9999, r(K) = 0.9997, r(BA) = 0.9995, r(IAA) = 0.9998, r(IPA) = 0.9982, r(IBA) = 0.9995 and r(NAA) = 0.9995. The method is rapid, simple and efficient. It is a suitable method for the accurate determination of gibberellic acid (GA) and alpha-naphthaleneacetic acid (alpha-NAA) in products for agricultural use.

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.

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.

Rapid determination of polycyclic aromatic hydrocarbons (PAHs) in tea using two-dimensional gas chromatography coupled with time of flight mass spectrometry.

PubMed

Drabova, Lucie; Pulkrabova, Jana; Kalachova, Kamila; Tomaniova, Monika; Kocourek, Vladimir; Hajslova, Jana

2012-10-15

A simple, fast, and cost effective sample preparation procedure has been developed and validated for the determination of 15+1 European Union Polycyclic Aromatic Hydrocarbons (15+1 EU PAHs) in dried tea leave samples. Based on a critical assessment of several sample extraction/clean-up approaches, the method based on the ethyl acetate extraction followed by the use of PAHs dedicated cartridges with molecularly imprinted polymers (MIPs) has been found as an optimal alternative in terms of time demands and obtained good extract purity. For the final identification/quantification of target PAHs, two dimensional gas chromatography coupled to a time-of-flight mass spectrometry (GC×GC-TOFMS) was used. The performance characteristics of the overall analytical method for individual PAHs determined at three spiking levels (0.5, 2.5 and 5 μg kg(-1)) were in following ranges: limits of quantitation (LOQs) 0.05-0.2 μg kg(-1), repeatabilities 2-9%, and recoveries 73-103%. The recoveries achieved by the newly developed sample preparation procedure when employed for naturally contaminated sample ("incurred" PAHs) were comparable to those obtained by other routinely used approaches employing sonication and/or pressurised liquid extraction for sample analytes isolation. The validated method was subsequently used for the determination of selected genotoxic PAHs in 36 samples of black and green tea obtained from the Czech retail market. The levels of ΣPAH4 (sum of benzo[a]anthracene (BaA), chrysene (CHR), benzo[b]fluoranthene (BbFA) and benzo[a]pyrene (BaP)) in black and green tea leaves ranged from 7.4 to 700 μg kg(-1) and from 4.5 to 102 μg kg(-1), respectively. Contamination of tested tea samples by BaP was in the range of 0.2-152 μg kg(-1). Copyright © 2012 Elsevier B.V. All rights reserved.

Metabolic engineering of Clostridium acetobutylicum for enhanced production of butyric acid.

PubMed

Jang, Yu-Sin; Woo, Hee Moon; Im, Jung Ae; Kim, In Ho; Lee, Sang Yup

2013-11-01

Clostridium acetobutylicum has been considered as an attractive platform host for biorefinery due to its metabolic diversity. Considering its capability to overproduce butanol through butyrate, it was thought that butyric acid can also be efficiently produced by this bacterium through metabolic engineering. The pta-ctfB-deficient C. acetobutylicum CEKW, in which genes encoding phosphotransacetylase and CoA-transferase were knocked out, was assessed for its potential as a butyric acid producer in fermentations with four controlled pH values at 5.0, 5.5, 6.0, and 6.4. Butyric acid could be best produced by fermentation of the CEKW at pH 6.0, resulting in the highest titer of 26.6 g/l, which is 6.4 times higher than that obtained with the wild type. However, due to the remaining solventogenic ability of the CEKW, 3.6 g/l solvents were also produced. Thus, the CEKW was further engineered by knocking out the adhE1-encoding aldehyde/alcohol dehydrogenase to prevent solvent production. Batch fermentation of the resulting C. acetobutylicum HCEKW at pH 6.0 showed increased butyric acid production to 30.8 g/l with a ratio of butyric-to-acetic acid (BA/AA) of 6.6 g/g and a productivity of 0.72 g/l/h from 86.9 g/l glucose, while negligible solvent (0.8 g/l ethanol only) was produced. The butyric acid titer, BA/AA ratio, and productivity obtained in this study were the highest values reported for C. acetobutylicum, and the BA/AA ratio and productivity were also comparable to those of native butyric acid producer Clostridium tyrobutyricum. These results suggested that the simultaneous deletion of the pta-ctfB-adhE1 in C. acetobutylicum resulted in metabolic switch from biphasic to acidogenic fermentation, which enhanced butyric acid production.

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

Clonal propagation of Phyllanthus amarus: A hepatoprotector

PubMed Central

Xavier, Janifer R.; Gnanam, Ramaswamy; Murugan, Muthiah P.; Pappachan, Anju

2012-01-01

Background: The micropropagation protocol for Phyllanthus amarus, an important medicinal herb used widely for the treatment of hepatitis in ethnomedicinal systems, was standardized with shoot tip and single node explants. Materials and Methods: The micropropagation was carried out for the hyperproducing ecotype (phyllanthin content 463.828 ppm; hypophyllanthin content: 75.469 ppm) collected from Aanaikatti, Coimbatore, and grown in mist chamber, CPMB, TNAU. For micropropagation studies, the leaves were trimmed off and the shoot tips (6 mm long) and nodal segments (single node) were used for initiation. Results: Shoot tips and single node explants gave a maximum of 6.00 and 7.00 multiple shoots per explant with Benzyl Amino Purine (BAP) (1.0mg/L mg/L). Upon subculturing, a shoot length of around 7 cm with an average of eight internodes per shoot was observed after 20 days in the elongation medium supplemented with BAP (0.2 mg/Lmg/L) and Indole Acetic Acid (IAA) (2.0 mg/L). Seven to ten adventitious roots developed when the elongated microshoots were cultured in half strength MS medium with Indole Butyric Acid (IBA) (2.0 mg/Lmg/L) and NAA (1.0 mg/L mg/L) in 15-20 days after transfer. The rooted shoots acclimatized successfully to field conditions. Conclusion: A method for successful micropropagation of the valuable medicinal plant was established which will provide a better source for continuous supply of plants for manufacturing drugs. PMID:22438668

Geraniol and Geranial Dehydrogenases Induced in Anaerobic Monoterpene Degradation by Castellaniella defragrans

PubMed Central

Lüddeke, Frauke; Wülfing, Annika; Timke, Markus; Germer, Frauke; Weber, Johanna; Dikfidan, Aytac; Rahnfeld, Tobias; Linder, Dietmar; Meyerdierks, Anke

2012-01-01

Castellaniella defragrans is a Betaproteobacterium capable of coupling the oxidation of monoterpenes with denitrification. Geraniol dehydrogenase (GeDH) activity was induced during growth with limonene in comparison to growth with acetate. The N-terminal sequence of the purified enzyme directed the cloning of the corresponding open reading frame (ORF), the first bacterial gene for a GeDH (geoA, for geraniol oxidation pathway). The C. defragrans geraniol dehydrogenase is a homodimeric enzyme that affiliates with the zinc-containing benzyl alcohol dehydrogenases in the superfamily of medium-chain-length dehydrogenases/reductases (MDR). The purified enzyme most efficiently catalyzes the oxidation of perillyl alcohol (kcat/Km = 2.02 × 106 M−1 s−1), followed by geraniol (kcat/Km = 1.57 × 106 M−1 s−1). Apparent Km values of <10 μM are consistent with an in vivo toxicity of geraniol above 5 μM. In the genetic vicinity of geoA is a putative aldehyde dehydrogenase that was named geoB and identified as a highly abundant protein during growth with phellandrene. Extracts of Escherichia coli expressing geoB demonstrated in vitro a geranial dehydrogenase (GaDH) activity. GaDH activity was independent of coenzyme A. The irreversible formation of geranic acid allows for a metabolic flux from β-myrcene via linalool, geraniol, and geranial to geranic acid. PMID:22286981

Geraniol and geranial dehydrogenases induced in anaerobic monoterpene degradation by Castellaniella defragrans.

PubMed

Lüddeke, Frauke; Wülfing, Annika; Timke, Markus; Germer, Frauke; Weber, Johanna; Dikfidan, Aytac; Rahnfeld, Tobias; Linder, Dietmar; Meyerdierks, Anke; Harder, Jens

2012-04-01

Castellaniella defragrans is a Betaproteobacterium capable of coupling the oxidation of monoterpenes with denitrification. Geraniol dehydrogenase (GeDH) activity was induced during growth with limonene in comparison to growth with acetate. The N-terminal sequence of the purified enzyme directed the cloning of the corresponding open reading frame (ORF), the first bacterial gene for a GeDH (geoA, for geraniol oxidation pathway). The C. defragrans geraniol dehydrogenase is a homodimeric enzyme that affiliates with the zinc-containing benzyl alcohol dehydrogenases in the superfamily of medium-chain-length dehydrogenases/reductases (MDR). The purified enzyme most efficiently catalyzes the oxidation of perillyl alcohol (k(cat)/K(m) = 2.02 × 10(6) M(-1) s(-1)), followed by geraniol (k(cat)/K(m) = 1.57 × 10(6) M(-1) s(-1)). Apparent K(m) values of <10 μM are consistent with an in vivo toxicity of geraniol above 5 μM. In the genetic vicinity of geoA is a putative aldehyde dehydrogenase that was named geoB and identified as a highly abundant protein during growth with phellandrene. Extracts of Escherichia coli expressing geoB demonstrated in vitro a geranial dehydrogenase (GaDH) activity. GaDH activity was independent of coenzyme A. The irreversible formation of geranic acid allows for a metabolic flux from β-myrcene via linalool, geraniol, and geranial to geranic acid.

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.

Micropropagation of Gerbera (Gerbera jamesonii Bolus).

PubMed

Minerva, Ghani; Kumar, Surinder

2013-01-01

Gerbera (Gerbera jamesonii Bolus) is one of the most popular ornamental flowers worldwide and used both as cut flower and potted plant. Some of them show excellent agronomic characters such as color, floral diameter, stem length, and vigor, which make this plant of commercial importance. Conventionally, multiplication is done through seeds or rhizome cuttings. Rapid multiplication of elite cultivars of Gerbera, with improved agronomic traits, has been achieved by using both direct and indirect tissue culture methods. Direct shoot regeneration was accomplished from stem apices on MS medium supplemented with 1 mg/L 6-benzyladenine (BA) and 1 mg/L kinetin. Indirect shoot induction succeeded from callus differentiation has been achieved on MS medium containing 2 mg/L 2,4-dichlorophenoxyacetic acid, 0.5 mg/L indole-3-acetic acid, and 2 mg/L BA. The in vitro shoots, 4-5 cm long, were rooted by quick dipping the shoot bases for 3-5 s in 2,000 mg/L indole-3-butyric acid solution followed by transfer to the pots containing farmyard manure, soil, and sand (1:1:1 by volume). Initially, in vitro plantlets were covered with glass jars to maintain a high relative humidity (85-90%). As soon as new shoot growth begins, relative humidity is decreased by exposing them to the open environmental conditions prior transferring to the glasshouse. Indirect shoot regeneration increased the frequency of somaclonal variations. The selected somaclones were used in developing new and novel cultivars.

Heat-induced phytohormone changes are associated with disrupted early reproductive development and reduced yield in rice

PubMed Central

Wu, Chao; Cui, Kehui; Wang, Wencheng; Li, Qian; Fahad, Shah; Hu, Qiuqian; Huang, Jianliang; Nie, Lixiao; Peng, Shaobing

2016-01-01

Heat stress causes morphological and physiological changes and reduces crop yield in rice (Oryza sativa). To investigate changes in phytohormones and their relationships with yield and other attributes under heat stress, four rice varieties (Nagina22, Huanghuazhan, Liangyoupeijiu, and Shanyou 63) were grown in pots and subjected to three high temperature treatments plus control in temperature-controlled greenhouses for 15 d during the early reproductive phase. Yield reductions in Nagina22, Huanghuazhan, and Liangyoupeijiu were attributed to reductions in spikelet fertility, spikelets per panicle, and grain weight. The adverse effects of high temperature were alleviated by application of exogenous 6-benzylaminopurine (6-BA) in the heat-susceptible Liangyoupeijiu. High temperature stress reduced active cytokinins, gibberellin A1 (GA1), and indole-3-acetic acid (IAA), but increased abscisic acid (ABA) and bound cytokinins in young panicles. Correlation analyses and application of exogenous 6-BA revealed that high temperature-induced cytokinin changes may regulate yield components by modulating the differentiation and degradation of branches and spikelets, panicle exsertion, pollen vigor, anther dehiscence, and grain size. Heat-tolerant Shanyou 63 displayed minor changes in phytohormones, panicle formation, and grain yield under high temperature compared with those of the other three varieties. These results suggest that phytohormone changes are closely associated with yield formation, and a small reduction or stability in phytohormone content is required to avoid large yield losses under heat stress. PMID:27713528

Microbiological and chemical profiles of elephant grass inoculated with and without Lactobacillus plantarum and Pediococcus acidilactici.

PubMed

Shah, Assar Ali; Xianjun, Yuan; Zhihao, Dong; Junfeng, Li; Sao, Tao

2018-03-01

The study was conducted to evaluate the microbiological and chemical profiles of elephant grass inoculated with and without different wild strains of lactic acid bacteria. Silage was prepared of four treatments and one control with three replicates as control (EKC, adding 2 ml/kg sterilizing water), Lactobacillus plantarum (USA commercial bacteria) (EKP), Lactobacillus plantarum (EKA), Pediococcus acidilactici (EKB), and Pediococcus acidilactici (SKD) isolated from King grass. Silage were prepared using polyethylene terephthalate bottles, and incubated at room temperature for different ensiling days. The pH and acetic acid (AA) were significantly (P < 0.05) reduced and lactic acid (LA), butyric acid (BA), and ethanol were significantly increased (P < 0.05) at 3, 5, 7, and 14 days in treatment groups as compared to control. Water-soluble carbohydrate (WSC) and NH 3 -N concentration was not affected at days 3, 5, and 7, but significantly (P < 0.05) reduced at 14 days in treatment groups as compared to control. The LA, BA, and ethanol were significantly (P < 0.05) increased and AA, WSC NH 3 -N, and yeast were significantly (P < 0.05) decreased at 30 days of ensiling in treatment groups as compared to control. It is recommended that the inoculation of LAB could improve the fermentation quality of elephant grass silage and further effort is needed to evaluate these effects on silage produced on farm scale and on animal production performance.

Bacteria isolated from Korean black raspberry vinegar with low biogenic amine production in wine.

PubMed

Song, Nho-Eul; Cho, Hyoun-Suk; Baik, Sang-Ho

2016-01-01

A high concentration of histamine, one of the biogenic amines (BAs) usually found in fermented foods, can cause undesirable physiological side effects in sensitive humans. The objective of this study is to isolate indigenous Acetobacter strains from naturally fermented Bokbunja vinegar in Korea with reduced histamine production during starter fermentation. Further, we examined its physiological and biochemical properties, including BA synthesis. The obtained strain MBA-77, identified as Acetobacter aceti by 16S rDNA homology and biochemical analysis and named A. aceti MBA-77. A. aceti MBA-77 showed optimal acidity % production at pH 5; the optimal temperature was 25°C. When we prepared and examined the BAs synthesis spectrum during the fermentation process, Bokbunja wine fermented with Saccharomyces cerevisiae showed that the histamine concentration increased from 2.72 of Bokbunja extract to 5.29mg/L and cadaverine and dopamine was decreased to 2.6 and 10.12mg/L, respectively. Bokbunja vinegar prepared by A. aceti MBA-77 as the starter, the histamine concentration of the vinegar preparation step was decreased up to 3.66mg/L from 5.29mg/L in the wine preparation step. To our knowledge, this is the first report to demonstrate acetic acid bacteria isolated from Bokbunja seed vinegar with low spectrum BA and would be useful for wellbeing vinegar preparation. Copyright © 2016 Sociedade Brasileira de Microbiologia. Published by Elsevier Editora Ltda. All rights reserved.

Processing And Patterning Of Thin Film Superconductors Formed By Metallo-Organic Deposition

NASA Astrophysics Data System (ADS)

Micheli, Adolph L.; Mantese, Joseph V.; Hamdi, Aboud H.

1990-04-01

Thin film superconductors of Y-Ba-Cu and Yb-Ba-Cu were formed by the pyrolysis of neodecanoate solutions of Y, Yb, Ba and Cu which had been deposited onto <100> SrTiO3 substrates [1]. Rapid thermal annealing, in oxygen, of the as-deposited films produced high T films having superconducting onset temperatures above 90 K and zero resistance at 8g K. Scanning Electron Microscopy (SEM) revealed enhancements in grain growth, compared to furnace annealed films, by a factor of 4. X-ray diffraction analysis showed preferred epitaxial grain growth with the c-axis of the films oriented both perpendicular and parallel to the substrate surface. Separate Rutherford Backscattering Spectrometry (RBS) channeling experiments confirmed the formation of preferred epitaxial grain growth. Film composition was determined by RBS and Inductively Coupled Plasma Emission Spectrometry (ICPES). Selective patterning was accomplished by focused beam exposure of the metal neodecanoate films [2-4]. The exposure rendered the neodecanoate film locally insoluble in xylene, thus permitting selective area patterning prior to pyrolysis. Electron, ion and laser beams were used to pattern films on <100> SrTiO3. The finest lines, approximately 5 #m in width and 26 nm thick, were patterned using electron beams whose lines had superconducting onsets above 90 K and zero resistance at 69 K after rapid thermal annealing. Both ion beam and laser patterning had similar superconducting onsets and zero resistance. Neodecanoates of Y, Yb, Ba, and Cu were formed, as previously described [5], by reacting the metal acetates of these materials with either ammonium neodecanoate or tetramethyl ammonium neodecanoate. The carboxylates formed from these reactions were then dissolved in a solution of xylene and pyridine. The individual chemical constituents were combined to produce solutions, Ln:Ba:Cu, in the ratio 1:2:4. Here, Ln is a rare-earth element. Details of the preparation of the metal carboxylates may be found elsewhere [6]. Thin films of Y-Ba-Cu and Yb-Ba-Cu were deposited onto <100> SrTiO by flooding the substrates with the appropriate neodecanoate solutions, then spin drying them at 2000 rpm for 30 s. The substrates were heated rapidly to 500?°C for 5 min in an air oven to pyrolize the metallo organics to their oxides. This process produces thin films about 200 nm thick. The spin coating process was repeated 3-6 times if thicker films were desired. X-ray diffraction analysis of films pyrolized at 500?°C shoed the presence of only microcrystallites. Room temperature resistivities of lx10 0-cm were measured for these films. No superconducting behavior was observed. After the 500?°C pyrolysis the films were further processed by RTA in flowing oxygen. The substrates were placed upon oxidized silicon wafers, rapidly heated to 850?°C for 60 s using infrared radiation produced by a bank of quartz lamps then allowed to cool to room temperature. A second rapid annealing was then performed at 920?°C for 30 s in oxygen. Thin film superconductors formed in the manner described above were very uniform in structure and thickness across the surface of the film. The grains are approximately 1 #m wide and 2 #m long, a factor of 4 larger than the grains found in furnace annealed films formed by MOD [5].

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.

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

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

Pterostilbene is equally potent as resveratrol in inhibiting 12-O-tetradecanoylphorbol-13-acetate activated NFkappaB, AP-1, COX-2, and iNOS in mouse epidermis.

PubMed

Cichocki, Michal; Paluszczak, Jaroslaw; Szaefer, Hanna; Piechowiak, Adriana; Rimando, Agnes M; Baer-Dubowska, Wanda

2008-06-01

Resveratrol, a phytoalexin present in grapes, has been reported to inhibit multistage mouse skin carcinogenesis. Recent studies showed that topically applied resveratrol significantly inhibited cyclooxygenase-2 (COX-2) expression and activation of nuclear factor-kappaB (NF-kappaB) induced by tumor promoter 12-O-tetradecanoylphorbol-13-acetate (TPA) in mouse epidermis. The aim of the present study was to further explore the effect of resveratrol on TPA-induced signaling pathways in mouse epidermis and to compare with its dimethylether, pterostilbene. Resveratrol and pterostilbene significantly reduced activator protein 1 (AP-1) and NF-kappaB activation. In the case of AP-1, the binding of c-Jun subunit was particularly affected, while only slight effect on c-Fos binding to TPA-responsive element (AP-1 binding consensus sequence) (TRE) site was observed. Both stilbenes inhibited the activation of NF-kappaB by blocking the translocation of p65 to the nucleus and increasing the retention of IkappaBa in the cytosol. The latter might be related to decreased activity of IkappaB kinase and/or proteasome 20S. Reduced activation of transcription factors decreased the expression and activity of COX-2 and inducible nitric oxide synthase (iNOS). In most assays, pterostilbene was either equally or significantly more potent than resveratrol. Pterostilbene might show higher biological activity due to its possible better bioavailability, since substitution of hydroxy with methoxy group increases lipophilicity.

Kinetics of waterborne fluoropolymers prepared by one-step semi-continuous emulsion polymerization of chlorotrifluoroethylene, vinyl acetate, butyl acrylate and Veova 10

NASA Astrophysics Data System (ADS)

Liu, H. Z.; Wang, M. H.; Wang, Z. F.; Bian, J. M.

2018-01-01

Due to using gaseous fluorine monomer with toxicity, waterborne fluoropolymers are synthesized by semi-continuous high-pressure emulsion polymerization method which differs from free-pressure emulsion polymerization. To dates, the research on preparing process and kinetics for high-pressure emulsion polymerization is reported relatively less, which hinders researchers from understanding of mechanisms for monomer-fluorinated emulsion polymerization. The paper also provides a new method by element auxiliary analysis to calculate kinetics parameters of high-pressure emulsion polymerization. Based on aforementioned consideration, waterborne fluoropolymers were prepared by copolymerization of chlorotrifluoroethylene (CTFE), vinyl acetate (VAc), butyl acrylate (BA) and vinyl ester of versatic acid (Veova 10) using potassium persulfate as initiator and mixed surfactants. The kinetics of emulsion polymerization of waterborne fluoropolymers was then investigated. Effects of emulsifier concentration, initiator concentration, and polymerization temperature on polymerization rate (Rp) were evaluated, and relationship was described as Rp∝[I]0.10 and Rp∝[E]0.12. The apparent activation energy was determined to be 33.61 kJ·mol-1. Moreover, the relative conversion rate of CTFE with the other monomers was observed, and results indicated that CTFE monomer more uniformly copolymerized with the other monomers. The resulting emulsion properties and pressure change in an autoclave were evaluated at different stirring rates. The initial reaction time, defined as the beginning time of dropwise addition, was determined by the change in solid content and particle size of emulsion.

Rapid in vitro multiplication and restoration of Celastrus paniculatus Willd. sub sp. paniculatus (Celastraceae), a medicinal woody climber.

PubMed

Nair, L G; Seeni, S

2001-07-01

Nodes, shoot tips, internodes and leaf bases (approximately 1.0 cm) excised from young vines of the flowering woody climber, Celastrus paniculatus WilId. sub. sp. paniculatus (Celastraceae) were cultured in Murashige and Skoog (MS) medium containing agar (0.6%), sucrose (3%) and varied concentrations of 6-benzyl aminopurine (BAP) and kinetin. All the explant types were regenerative and maximum number (3.6) and frequency (94%) of axillary shoot formation of (5.08 cm long) was recorded in the nodes cultured in BAP (1 mg L(-1)) after 6 weeks. Combinations of BAP (1 mg L(-1)) and indole-3-acetic acid/l-naphthalene acetic acid (0.01-1 mg L(-1); IAA/NAA) tested with nodes induced formation of less number (3 and 2.2) of shoots at same frequency (94%). All the explant types viz. node, shoot tip, internode and leaf base of in vitro derived shoots responded earlier and better in lower concentrations of BAP (0.5-2 mg L(-1)) with formation of 8, 3.1, 6.4 and 1.8 shoots respectively during the same period. In spite of the advanced and increased caulogenic responses, differences in cytokinin requirements between different explants observed during culture initiation still persisted with the nodes, shoot tips, internodes and petiole segments responding best at 0.5, 1 and 2 mg L(-1) BAP, respectively. The repeated reculture up to 10 cycles of the nodes from the shoot cultures each at 6-week intervals enabled multiplication and stocking of shoots without decline. Rooting of 3-7 cm shoot cuttings was induced in half-strength MS liquid medium containing IAA (1 mg L(-1)) with formation of 7.25 roots of 2.41 cm length within 6 weeks. Rooted plants were established at 84-96% rate in community pots without hardening, the least value (84%) being obtained with NAA- induced thick and calloid rooted plants. Four month old community potted plants were reintroduced into native forest habitats at 95% efficiency and 8 months after restoration, the plants were uniform in morphological, growth, cytological and peroxidase and esterase isozyme characteristics.

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.

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

Candidate Microbicides Block HIV-1 Infection of Human Immature Langerhans Cells within Epithelial Tissue Explants

PubMed Central

Kawamura, Tatsuyoshi; Cohen, Sandra S.; Borris, Debra L.; Aquilino, Elisabeth A.; Glushakova, Svetlana; Margolis, Leonid B.; Orenstein, Jan M.; Offord, Robin E.; Neurath, A. Robert; Blauvelt, Andrew

2000-01-01

Initial biologic events that underlie sexual transmission of HIV-1 are poorly understood. To model these events, we exposed human immature Langerhans cells (LCs) within epithelial tissue explants to two primary and two laboratory-adapted HIV-1 isolates. We detected HIV-1Ba-L infection in single LCs that spontaneously emigrated from explants by flow cytometry (median of infected LCs = 0.52%, range = 0.08–4.77%). HIV-1–infected LCs downregulated surface CD4 and CD83, whereas MHC class II, CD80, and CD86 were unchanged. For all HIV-1 strains tested, emigrated LCs were critical in establishing high levels of infection (0.1–1 μg HIV-1 p24 per milliliter) in cocultured autologous or allogeneic T cells. HIV-1Ba-L (an R5 HIV-1 strain) more efficiently infected LC–T cell cocultures when compared with HIV-1IIIB (an X4 HIV-1 strain). Interestingly, pretreatment of explants with either aminooxypentane-RANTES (regulated upon activation, normal T cell expressed and secreted) or cellulose acetate phthalate (potential microbicides) blocked HIV-1 infection of LCs and subsequent T cell infection in a dose-dependent manner. In summary, we document HIV-1 infection in single LCs after exposure to virus within epithelial tissue, demonstrate that relatively low numbers of these cells are capable of inducing high levels of infection in cocultured T cells, and provide a useful explant model for testing of agents designed to block sexual transmission of HIV-1. PMID:11085750

Changes in cerebral metabolic activity in men undergoing androgen deprivation therapy for non-metastatic prostate cancer.

PubMed

Cherrier, M M; Cross, D J; Higano, C S; Minoshima, S

2018-04-27

Androgen deprivation therapy (ADT) is a common treatment option for men with biochemical relapse from prostate cancer. ADT is associated with changes in mood, cognition, and quality of life, and most recently with increased risk for Alzheimer's disease (AD). This study examined changes in brain metabolism using positron emission tomography (PET) in men undergoing intermittent ADT. Nine men with prostate cancer and a rising PSA (biochemical recurrence) without evidence of metastases were treated with intermittent ADT consisting of 9 months of complete androgen blockade achieved with combined leuprolide acetate and flutamide. Patients underwent resting [Fuorine-18] fluorodeoxyglucose PET ( 18 F-FDGPET) at baseline (before treatment) and again after 9 months of ADT. Whole-brain mapping analysis after 9 months of androgen deprivation compared to pretreatment baseline revealed decreased regional cerebral glucose metabolism in the cerebellum, posterior cingulate, and medial thalamus bilaterally. Associations of brain metabolism with measurements of cognition and mood while on androgen deprivation revealed positive correlations between the posterior cingulate, left inferior parietal lobule (BA40), and left mid temporal gyrus (BA39) and spatial reasoning and a negative correlation between left inferior parietal lobule and verbal memory. Several mood indices were negatively correlated with hypothalamus and brainstem. These findings suggest that complete androgen deprivation may result in changes in regional brain metabolism associated with variation in mood, verbal memory, and spatial performance. Brain regions that were impacted from ADT are similar and overlap with brain regions with metabolic decline found in early AD and diabetes, suggesting possible common mechanisms.

Pharmacokinetics of TAK-475, a Squalene Synthase Inhibitor, in Rats and Dogs.

PubMed

Ebihara, T; Teshima, K; Kondo, T; Tagawa, Y; Moriwaki, T; Asahi, S

2016-06-01

The pharmacokinetics of TAK-475 (lapaquistat acetate), a squalene synthase inhibitor, was investigated in rats and dogs. After oral administration of (14)C-labeled TAK-475 ([(14)C]TAK-475) to rats and dogs at a dose of 10 mg/kg, the bioavailability (BA) was relatively low at 3.5 and 8.2%, respectively. The main component of the radioactivity in the plasma was M-I, which has a comparable pharmacological activity to TAK-475 in vitro. The radioactivity in the portal plasma after intraduodenal administration of [(14)C]TAK-475 to portal vein-cannulated rat was also mainly M-I, suggesting that most of the TAK-475 was hydrolyzed to M-I during the permeable process in the intestine. The concentrations of M-I in the liver, the main organ of cholesterol biosynthesis, were much higher than those in the plasma after oral administration of [(14)C]TAK-475 to rats. The main elimination route of the radioactivity was fecal excretion after oral administration of [(14)C]TAK-475 to rats and dogs, and the absorbed radioactivity was mainly excreted via the bile as M-I in rats. M-I excreted into the bile was partially subjected to enterohepatic circulation. These results suggest that although the BA values of TAK-475 are low, M-I can exert compensatory pharmacological effects in the animals. These pharmacokinetic characteristics in animals were also confirmed in the clinical studies. The evaluation of M-I disposition is important for the pharmacokinetics, pharmacodynamics and toxicity of TAK-475 in animals and humans. © Georg Thieme Verlag KG Stuttgart · New York.

Sulphate transport by H+ symport and by the dicarboxylate carrier in mitochondria.

PubMed Central

Saris, N E

1980-01-01

1. Swelling of mitochondria was induced in non-respiring mitochondria by 30 mM or more Na2SO4 or by respiration in the presence of K2SO4. Respiration-drive swelling resulted in loss of respiratory control. Sulphate, when present at 10 mM concentration, promoted the release of accumulated Ca2+. 2. Swelling was prevented by N-ethylmaleimide and formaldehyde, known inhibitors of the phosphate carrier. Sulphate-induced swelling was more sensitive to the inhibitors than was phosphate-induced swelling. At lower concentration of sulphate, 5 mM, an alkalinisation of the medium was observed in addition of sulphate, indicating H+-sulphate symport. There was competition between sulphate and phosphate for transport by this mechanism. It is suggested that sulphate may be transported, though at a comparatively slow rate, by the phosphate carrier. 3. Uptake of sulphate was stimulated when preceded by energy-dependent accumulation of Ba2+, especially when acetate was also present, indicating precipitation of BaSO4 in the matrix. Using this system the influx of sulphate was studied at lower concentrations, 10 mM or less. the contributions of the H+ symporter (sensitive to N-ethylmaleimide) and the dicarboxylate carrier (sensitive to butylmalonate) could then be studied. The dicarboxylate carrier had a lower Km and was mainly responsible for sulphate transport at lower concentration range. At 10 mM-sulphate the transport rates by the two systems appeared to be similar; at still higher concentrations the H+ symporter may become more important. PMID:7236245

Deodorants on the European market: quantitative chemical analysis of 21 fragrances.

PubMed

Rastogi, S C; Johansen, J D; Frosch, P; Menné, T; Bruze, M; Lepoittevin, J P; Dreier, B; Andersen, K E; White, I R

1998-01-01

Deodorants are one of the most frequently used types of cosmetics and side-effects from them are common. Recent studies relate perfume allergy to this type of product. 73 deodorants were analyzed by gas chromatography--mass spectrometry for the determination of the contents of 7 wellknown fragrance allergens from the fragrance mix and 14 other commonly used fragrance materials. The deodorants were purchased at retail outlets in 5 European countries. It was found that in general, fragrance mix ingredients were more frequently present in vapo- and aerosol sprays than in roll-on products. The levels of the fragrance mix substances ranged from 0.0001-0.2355%. The products investigated contained cinnamic aldehyde and isoeugenol less frequently (17% and 29% respectively), and eugenol and geraniol most frequently (57% and 76% respectively). The 14 other fragrance materials were found in 40-97% of the deodorants, with hedione and benzyl acetate the most frequently found substances. The concentration of these 14 substances ranged from 0.0001-2.7%. It is concluded that the levels of cinnamic aldehyde and isoeugenol found in the deodorants could prove to be relevant for elicitation of contact dermatitis. No conclusions could be drawn about the other fragrance mix constituents, as threshold levels in sensitized individuals have not been investigated. Furthermore, all of the fragrance materials investigated were frequently found in deodorants and, apart from the fragrance mix ingredients, the extent of problems with sensitization to these fragrance materials is largely unknown.

Kinetics and mechanism of hydration of o-thioquinone methide in aqueous solution. Rate-determining protonation of sulfur.

PubMed

Chiang, Yvonne; Kresge, A Jerry; Sadovski, Oleg; Zhan, Hao-Qiang

2005-03-04

o-Thioquinone methide, 2, was generated in aqueous solution by flash photolysis of benzothiete, 1, and rates of hydration of this quinone methide to o-mercaptobenzyl alcohol, 3, were measured in perchloric acid solutions, using H2O and D2O as the solvent, and also in acetic acid and tris(hydroxymethyl)methylammonium ion buffers, using H2O as the solvent. The rate profiles constructed from these data show hydronium-ion-catalyzed and uncatalyzed hydration reaction regions, just like the rate profiles based on literature data for hydration of the oxygen analogue, o-quinone methide, of the presently examined substrate. Solvent isotope effects on hydronium-ion catalysis of hydration for the two substrates, however, are quite different: k(H)/k(D) = 0.42 for the oxygen quinone methide, whereas k(H)/k(D) = 1.66 for the sulfur substrate. The inverse nature (k(H)/k(D) < 1) of the isotope effect in the oxygen system indicates that this reaction occurs by a preequilibrium proton-transfer reaction mechanism, with protonation of the substrate on its oxygen atom being fast and reversible and capture of the benzyl-type carbocationic intermediate so formed being rate-determining. The normal direction (k(H)/k(D) > 1) of the isotope effect in the sulfur system, on the other hand, suggests that protonation of the substrate on its sulfur atom is in this case rate-determining, with carbocation capture a fast following step. A semiquantitative argument supporting this hypothesis is presented.

Terpenoid constituents of cinnamon and clove essential oils cause toxic effects and behavior repellency response on granary weevil, Sitophilus granarius.

PubMed

Plata-Rueda, Angelica; Campos, Juliana Mendonça; da Silva Rolim, Gabriela; Martínez, Luis Carlos; Dos Santos, Marcelo Henrique; Fernandes, Flávio Lemes; Serrão, José Eduardo; Zanuncio, José Cola

2018-07-30

This study evaluated toxic effects, repellency and respiration rate caused by terpenoid constituents of cinnamon and clove essential oils and against Sitophilus granarius L. (Coleoptera: Curculionidae). The lethal concentrations (LC 50 and LC 90 ), repellent effect, and behavior repellency response on adults of S. granarius after exposure to six concentrations of each essential oil and terpenoids were evaluated. The chemical composition of the cinnamon oil was also determined and primary compounds were eugenol (10.5%), trans-3-caren-2-ol (10.2%), benzyl benzoate (9.99%), caryophyllene (9.34%), eugenyl acetate (7.71%), α-phellandrene (7.41%), and α-pinene (7.14%). In clove essential oil, the primary compounds were eugenol (27.1%), caryophyllene (24.5%), caryophyllene oxide (18.3%), 2-propenoic acid (12.2%), α-humulene (10.8%), γ-cadinene (5.01%), and humulene oxide (4.84%). Cinnamon and clove essential oil was toxic to S. granarius. In toxic terpenoids compounds, eugenol has stronger contact toxicity in S. granarius than caryophyllene oxide, followed by α-pinene, α-humulene, and α-phellandrene. Insects reduced their respiratory rates after being exposed to essential oil terpenoids and avoided or reduced their mobility on terpenoid-treated surfaces. Cinnamon and clove essential oil, and their terpenoid constituents were toxic and repellent to adult S. granarius and, therefore, have the potential to prevent or retard the development of insecticide resistance. Copyright © 2018 Elsevier Inc. All rights reserved.

The identification of polar organic compounds found in consumer products and their toxicological properties.

PubMed

Cooper, S D; Raymer, J H; Pellizzari, E D; Thomas, K W

1995-01-01

Exposure to volatile organic compounds (VOCs) in the indoor environment has received substantial research attention in the past several years, with the goal of better understanding the impact of such exposures on human health and well-being. Many VOCs can arise from consumer products used within the indoor environment. The VOCs emitted from five representative consumer products were collected onto Tenax-GC and subjected to thermal desorption and analysis by gas chromatography, in combination with low-resolution mass spectrometry (MS), high-resolution MS, and matrix-isolation Fourier transform infrared spectroscopy for structural characterization. An emphasis was placed on the polar organic compounds often used to provide fragrance in these products. The structures of a number of these compounds were confirmed, and an electronic literature search was carried out on them to determine any known toxic properties. The search revealed that many of the VOCs possess toxic properties when studied at acute, relatively high-level exposures. In addition, toxic effects were reported for a few of the chemicals, such as benzaldehyde, alpha-terpineol, benzyl acetate, and ethanol, at relatively low dose levels of 9-14 mg/kg. In general, the data were unclear as to the effect of chronic, low-level exposures. The widespread use of such chemicals suggests that the health effects of chronic exposures need to be determined. Validated analytical methods for the quantitative characterization of polar organic compounds at low concentrations will be required to make such work possible.

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...

In vitro micropropagation of Dracaena sanderiana Sander ex Mast: An important indoor ornamental plant

PubMed Central

Aslam, Junaid; Mujib, Abdul; Sharma, Maheshwar Prasad

2012-01-01

A protocol has been developed for in vitro plant regeneration from a nodal explant of Dracaena sanderiana Sander ex Mast. Nodal explant showed high callus induction potentiality on MS medium supplemented with 6.78 μM 2,4-dichlorophenoxyacetic acid (2,4-D) followed by 46.5 μM chlorophenoxy acetic acid (CPA). The highest frequency of shoot regeneration (85%) and number of shoots per explant (5.6) were obtained on medium supplemented with 7.84 μM N6-benzylaminopurine (BA). Rooting was high on MS solid compared to liquid medium when added with 7.38 μM indole-3-butyric acid (IBA). Fifty percent of the roots were also directly rooted as microcuttings on soil rite, sand and peat mixture (1:1:1). In vitro and ex vitro raised plantlets were used for acclimatization. More than 90% of the plantlets was successfully acclimatized and established in plastic pots. Ex vitro transferred plantlets were normal without any phenotypic aberrations. PMID:23961221

In vitro micropropagation of Dracaena sanderiana Sander ex Mast: An important indoor ornamental plant.

PubMed

Aslam, Junaid; Mujib, Abdul; Sharma, Maheshwar Prasad

2013-01-01

A protocol has been developed for in vitro plant regeneration from a nodal explant of Dracaena sanderiana Sander ex Mast. Nodal explant showed high callus induction potentiality on MS medium supplemented with 6.78 μM 2,4-dichlorophenoxyacetic acid (2,4-D) followed by 46.5 μM chlorophenoxy acetic acid (CPA). The highest frequency of shoot regeneration (85%) and number of shoots per explant (5.6) were obtained on medium supplemented with 7.84 μM N(6)-benzylaminopurine (BA). Rooting was high on MS solid compared to liquid medium when added with 7.38 μM indole-3-butyric acid (IBA). Fifty percent of the roots were also directly rooted as microcuttings on soil rite, sand and peat mixture (1:1:1). In vitro and ex vitro raised plantlets were used for acclimatization. More than 90% of the plantlets was successfully acclimatized and established in plastic pots. Ex vitro transferred plantlets were normal without any phenotypic aberrations.

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.

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.

Preparation of directionally solidified BaTi2O5-Ba6Ti17O40 eutectic by the floating zone method

NASA Astrophysics Data System (ADS)

Shiga, K.; Katsui, H.; Goto, T.

2017-02-01

The BaTi2O5-Ba6Ti17O40 eutectic (BaO-68.7 mol% TiO2) was directionally solidified by the floating zone (FZ) method and crystalline phases, microstructures and orientation were investigated. Ba6Ti17O40 with faceted rod-like shape was dispersed in the BaTi2O5 matrix. The growth directions of BaTi2O5 and Ba6Ti17O40 were parallel to the b and a axis, respectively, and the orientation relations were BaTi2O5 (010)//Ba6Ti17O40(60 2 ̅) and BaTi2O5 (001)//Ba6Ti17O40 (001).

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...