WorldWideScience

Sample records for hexanes

  1. Radiation effects on n-hexane-urea inclusion compound

    International Nuclear Information System (INIS)

    Ohta, Nobuaki; Ozasa, Senichi; Ichikawa, Takahisa

    1987-01-01

    n-hexane-urea inclusion compounds were γ-irradiated at room temperature and dimers from n-hexane were found to form. Additive effects of 1-hexene, 1-chloropentane, and n-hexylamine to the formation of the dimers have been studied. For the comparison liquid n-hexane systems were also γ-irradiated under the same conditions. The radiation-induced reactions in the inclusion compounds are discussed together with the reactions in the liquid n-hexane systems. The dimers from n-hexane in the inclusion compounds are presumably formed by dimerization of hexyl radicals; the hexyl radicals are possibly produced by hydrogen abstraction of hydrogen atom and/or urea radicals from n-hexane included in urea. (author)

  2. Qualitative analysis of hexane flour extract of spelt

    Directory of Open Access Journals (Sweden)

    Vujić Đura N.

    2013-01-01

    Full Text Available Gas chromatography with mass spectrometry (GC-MS was used for performing a qualitative analysis of the hexane flour extract of three samples of spelt. All the three samples were first treated with hexane and the obtained extracts were used for the analysis of the fatty acid lipid components. The transesterification reaction was performed using TMSH (trimethylsulfonium hydroxide, 0.2M in methanol, and the fatty acids were esterified from acylglycerol to methyl-esters. In all analyzed extracts, the predominant component was methyl linoleate, followed by methyl oleate and methyl palmitate. The subsequent tests, performed by cluster analysis, were used to compare the hexane flour extracts of different types of spelt. [Projekat Ministarstva nauke Republike Srbije, br. III46005 i br. TR 31066

  3. Anti-venom potentials of Friedelin isolated from hexane extract ...

    African Journals Online (AJOL)

    ... taenicidal, cough remedy, dysentery, cancer, diabetes mellitus, tuberculosis and snake bite remedy. In this report, an attempt has been made to evaluate the bioactive molecules in the plant that are anti-venom agents. Consequently, the stem bark was exhaustively extracted with hexane and subsequently with methanol.

  4. Juglans regia Hexane Extract Exerts Antitumor Effect, Apoptosis ...

    African Journals Online (AJOL)

    Original Research Article. Juglans regia Hexane Extract Exerts Antitumor Effect,. Apoptosis Induction and Cell Circle Arrest in Prostate. Cancer Cells In vitro. Wei Li1, De-Yuan Li2*, ... composition of walnut is juglone (5-hydroxy-1, 4- naphthoquinone), the .... extract was confirmed by studying apoptotic body formation using ...

  5. Physicochemical characterisation of hexanic seed oil extract from ...

    African Journals Online (AJOL)

    The physicochemical characterisation of oil extracts from Schinus molle seeds collected in South Africa was performed. The oils were extracted in hexane, physicochemical parameters determined and lipids profiled by gas chromatography, in order to determine its potential for use in industry, ethnomedicine and its ...

  6. Effect of hexane treatment and uniaxial stretching on bending ...

    African Journals Online (AJOL)

    PVDF) film was studied. The quantity, β31, defined as the bending piezoelectric stress constant, was calculated. After hexane treatment and uniaxial stretching of the PVDF film, the value of β31 was 5.75 mV/m and 8.00 mV/m for draw ratio of ...

  7. Phytochemical And Antidiarrhoeal Evaluation Of The Hexane And ...

    African Journals Online (AJOL)

    The hexane and methanol extracts of the leaves were screened for possible antidiarrhoeal activities on mice gastrointestinal tract using two models which include measure of inhibition of castor oil- induced diarrhoea and measure of intestinal transit time. The phytochemical analysis revealed the presence of carbohydrates, ...

  8. Metabolic interaction between toluene, trichloroethylene and n-hexane in humans

    DEFF Research Database (Denmark)

    Bælum, Jesper; Mølhave, Lars; Hansen, S H

    1998-01-01

    This human experimental study describes the mutual metabolic interaction between toluene, trichloroethylene, and n-hexane.......This human experimental study describes the mutual metabolic interaction between toluene, trichloroethylene, and n-hexane....

  9. Antioxidant and antibacterial activities of acetonitrile and hexane extracts of Lentinus tigrinus and Pleurotus djamour

    Science.gov (United States)

    This paper highlighted the antioxidant and antibacterial activities of Lentinus tigrinus and Pleurotus djamour. Extracts of mushroom fruiting bodies were obtained using hexane and acetonitrile solvents. Acetonitrile extracts of both mushrooms exhibited higher biological activities than hexane extrac...

  10. HEXAN - a hexagonal nodal code for solving the diffusion equation

    International Nuclear Information System (INIS)

    Makai, M.

    1982-07-01

    This report describes the theory of and provides a user's manual for the HEXAN program, which is a nodal program for the solution of the few-group diffusion equation in hexagonal geometry. Based upon symmetry considerations, the theory provides an analytical solution in a homogeneous node. WWER and HTGR test problem solutions are presented. The equivalence of the finite-difference scheme and the response matrix method is proven. The properties of a symmetric node's response matrix are investigated. (author)

  11. Metabolic interaction between n-hexane and toluene in vivo and in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Perbellini, L.; Brugnone, F.; Leone, R.; Fracasso, M.E.; Venturini, M.S.

    1982-01-01

    Metabolic interference between n-hexane and toluene was studied both in vivo and in vitro. In in vivo experiments the urinary excretion of n-hexane and toluene metabolites was tested in rats treated with the two solvents separately or in combination. The same experimental program was repeated in rats pretreated with phenobarbital (PB). The urinary excretion of n-hexane metabolites in rats treated with the two solvents showed a significantly decreased excretion of all n-hexane metabolites in comparison with those treated with n-hexane alone. In rats pretreated with PB the excretion of n-hexane metabolites was significantly higher compared with that of unpretreated rats; the combined administration of the two solvents showed in this case, too, that n-hexane metabolite excretion was less than that found in rats treated with n-hexane alone. The biotransformation of toluene to o-cresol and hippuric acid studied in the urine of rats treated with or without n-hexane and pretreated or not with PB did not show any difference. The in vitro metabolic interference was studied by measuring the disappearance of solvents from rat's incubated liver microsomes. The inhibition constant of toluene on n-hexane biotransformation was 7.5 ..mu..M and that of n-hexane on toluene was 30 ..mu..M. The data show that a mutual non-competitive interference exists in vitro between n-hexane and toluene. The interference of toluene on n-hexane biotransformation was detectable also in vivo experiments, while n-hexane did not modify the biotransformation of toluene.

  12. Stability of carotenoids toward UV-irradiation in hexane solution

    Directory of Open Access Journals (Sweden)

    DRAGAN CVETKOVIC

    2008-01-01

    Full Text Available The stabilities of four selected carotenoids dissolved in hexane, two carotenes and two xanthophylls, toward UV-irradiation of three different ranges (UV-A, UV-B and UV-C were studied in this work. The carotenoids underwent bleaching via a probable free radical mediated mechanism following first-order kinetics. The bleaching rates were highly dependent on the input of the involved photons and, although not consistently, on the chemical structures of the investigated compounds. For the two xanthophylls, a possible role of oxygen associated with their bleaching cannot be neglected.

  13. Oil extraction from olive foot cake with acidic hexane

    Directory of Open Access Journals (Sweden)

    Kmieciak, S.

    1991-02-01

    Full Text Available The use of acidic hexane as a solvent increases the extracted oil yield from olive foot cake. Two extraction procedures are studied: open air extraction at room temperature and Soxhlet exhaustive extraction. The additional yield is about 5% for a 2.5% acetic acid content in case of open air extraction and turns out to be 9% for 7.5% acetic acid content in the Soxhlet procedure. An analysis of the extracted oil shows a light increase of the acidity of oil. The improved yield may be attributed to the action of acetic acid on the decomposition of intercellular structures and binding of some polar lipids. The phospholipids content of oil extracted with 7.5% acidic hexane is found to be 25 times more than with pure hexane.

    El uso de hexano ácido como disolvente aumenta el rendimiento de aceite extraído de orujo de aceituna. Se han estudiado dos procedimientos de extracción: extracción al aire libre a temperatura ambiente y extracción exhaustiva en Soxhlet. En el caso de extracción al aire libre el rendimiento adicional es alrededor del 5% para un contenido del 2'5% en ácido acético y llega a ser en el procedimiento en Soxhlet del 9% para un contenido en ácido acético del 7'5%. Un análisis del aceite extraído mostró un ligero aumento de la acidez del aceite. La mejora del rendimiento puede ser atribuida a la acción del ácido acético sobre la descomposición de estructuras intercelulares y uniones de lípidos polares. Se ha encontrado que el contenido en fosfolípidos del aceite extraído con el 7*5% de hexano ácido es 25 veces mayor que con hexano puro.

  14. Lipoxygenase independent hexanal formation in isolated soy proteins induced by reducing agents.

    Science.gov (United States)

    Lei, Q; Boatright, W L

    2008-08-01

    Compared to corresponding controls, 6.5 mM dithiothreitol (DTT) elevated headspace hexanal level over aqueous slurries of both commercial isolated soy proteins (ISP) and laboratory ISP prepared with 80 degrees C treatment. Further analysis revealed that lipoxygenase (LOX) activity was not detected from these ISP, indicating that LOX is not involved in the observed hexanal increase. Levels of the induced headspace hexanal over the ISP aqueous slurries were proportional to the amount of DTT added in the range of 0 to 65 mM. Subsequent systematic investigations with model systems revealed that iron was required for the reducing agent-induced hexanal formation from linoleic acid. Erythorbate, another reducing agent, can also induce hexanal formation in both ISP and model systems. As a comparison, the LOX activity and hexanal synthesis in defatted soy flour were examined. The corresponding results showed that defatted soy flour maintained high LOX activities and that hexanal synthesis in such sample was significantly inhibited by high concentration DTT (above 130 mM). Data from the current investigation demonstrate the existence of LOX independent hexanal formation induced by reducing agents in ISP and the potential requirement of iron as a catalyst.

  15. Analgesic and Anti-inflammatory Profile of n-Hexane Fraction of ...

    African Journals Online (AJOL)

    Purpose: To evaluate the analgesic and anti-inflammatory activities of n-hexane extract of the whole plant of Viola betonicifolia Sm, family: Violaceace. Methods: The n-hexane fraction of Viola betonicifolia (VBHF) was tested for its analgesic and antiinflammatory activities (carrageenan-induced and histamine-induced ...

  16. Structure of solid monolayers and multilayers of n-hexane on graphite

    Indian Academy of Sciences (India)

    Unknown

    We present all-atom molecular dynamics simulations of n-hexane on the ... cluster of n-hexane molecules on graphite, using the all-atom interaction model. ... We do not include such molecules in our analyses of the structure factor and other.

  17. evaluation of commercial FCC catalysts for hydrocarbon conversion. I. Physicochemical characterization and n-hexane conversion.

    NARCIS (Netherlands)

    Brait, A.; Brait, A.; Seshan, Kulathuiyer; Lercher, J.A.

    1998-01-01

    The physicochemical properties of six steam-stabilized, commercial FCC catalysts were compared in respect of their catalytic activity for n-hexane conversion. The conversion of n-hexane over these catalysts could be fully explained by three reaction pathways: protolytic cracking, protolytic

  18. Absorption and recovery of n-hexane in aqueous solutions of fluorocarbon surfactants.

    Science.gov (United States)

    Xiao, Xiao; Yan, Bo; Fu, Jiamo; Xiao, Xianming

    2015-11-01

    n-Hexane is widely used in industrial production as an organic solvent. As an industrial exhaust gas, the contribution of n-hexane to air pollution and damage to human health are attracting increasing attention. In the present study, aqueous solutions of two fluorocarbon surfactants (FSN100 and FSO100) were investigated for their properties of solubilization and dynamic absorption of n-hexane, as well as their capacity for regeneration and n-hexane recovery by thermal distillation. The results show that the two fluorocarbon surfactants enhance dissolution and absorption of n-hexane, and their effectiveness is closely related to their concentrations in solution. For low concentration solutions (0.01%-0.30%), the partition coefficient decreases dramatically and the saturation capacity increases significantly with increasing concentration, but the changes for both are more modest when the concentration is over 0.30%. The FSO100 solution presents a smaller partition coefficient and a greater saturation capacity than the FSN100 solution at the same concentration, indicating a stronger solubilization for n-hexane. Thermal distillation is a feasible method to recover n-hexane from these absorption solutions, and to regenerate them. With 90sec heating at 80-85°C, the recovery of n-hexane ranges between 81% and 85%, and the regenerated absorption solution maintains its original performance during reuse. This study provides basic information on two fluorocarbon surfactants for application in the treatment of industrial n-hexane waste gases. Copyright © 2015. Published by Elsevier B.V.

  19. Effect of hexane extract of spinach in the removal of arsenic from rat

    Directory of Open Access Journals (Sweden)

    Badar Uddin Umar

    2007-03-01

    Full Text Available Extensive search is going on for a cheap, easily available and effective remedy of chronic arsenic poisoning. The present study was designed to find the effects of hexane extract of spinach in the removal of arsenic from arsenic treated rat. Rats were fed arsenic trioxide through Ryle’s tube for one month then they were fed on hexane extract (1-4% of spinach for another one month. Hexane extract of spinach decreased accumulated arsenic from rat liver, spleen, kidney, intestine, lungs and skin significantly. Besides, it reduced the oxidative stress caused by arsenic which was evident by decreased levels of malondialdehye (MDA in the above tissues. Hexane extract decreases both arsenic level and MDA level in rat tissues in dose dependent manner, which is more effective at lower doses.

  20. Effect of hexane extract of spinach in the removal of arsenic from rat

    Directory of Open Access Journals (Sweden)

    Badar Uddin Umar

    2007-06-01

    Full Text Available Extensive search is going on for a cheap, easily available and effective remedy of chronic arsenic poisoning. The present study was designed to find the effects of hexane extract of spinach in the removal of arsenic from arsenic treated rat. Rats were fed arsenic trioxide through Ryle’s tube for one month then they were fed on hexane extract (1-4% of spinach for another one month. Hexane extract of spinach decreased accumulated arsenic from rat liver, spleen, kidney, intestine, lungs and skin significantly. Besides, it reduced the oxidative stress caused by arsenic which was evident by decreased levels of malondialdehyde (MDA in the above tissues. Hexane extract decreases both arsenic level and MDA level in rat tissues in dose dependent manner, which is more effective at lower doses.

  1. Spermicidal activity of the hexane extract of Piper longum: an in vitro study.

    Science.gov (United States)

    Sarwar, Abu Hasnath Md Golam; Nirala, Ranjeet Kumar; Arif, Mohammed; Khillare, Beena; Thakur, Sonu Chand

    2015-01-01

    This study was carried out to assess the spermicidal action of hexane extract from the fruits of Piper longum Linn. The sperm immobilisation studies showed that 20 mg/mL of hexane extract was able to immobilise sperms completely within 20 s. The sperm revival test revealed that the effects were spermicidal as sperm immobilisation effect was irreversible. There was also a significant reduction in sperm viability in the treated group in comparison to the control. The hypo-osmotic swelling of these sperms was significantly reduced, indicating that the hexane extract may probably cause injury to the sperm plasma membrane. Hence, this study showed that the hexane extract of P. longum possesses potential contraceptive spermicidal activity in vitro.

  2. Physical properties of (propyl propanoate + hexane + toluene) at 298.15 K

    International Nuclear Information System (INIS)

    Freire, S.; Segade, L.; Cabeza, O.; Jimenez, E.

    2007-01-01

    The aim of this paper is to report experimental densities, excess molar enthalpies and refractive indexes of the ternary system (propyl propanoate + hexane + toluene) and of the corresponding binary mixtures (propyl propanoate + toluene) and (hexane + toluene) at the temperature 298.15 K and atmospheric pressure, over the whole composition range. Also, the excess molar volumes and the changes in the refractive index on mixing have been calculated from the measured data for all mixtures

  3. Treatment of Benzene and n-Hexane Mixtures in Trickle-Bed Air Biofilters.

    Science.gov (United States)

    Hassan, Ashraf Aly; Sorial, George A

    2011-02-01

    Trickle-bed air biofilters (TBABs) are suitable for treatment of hydrophilic volatile organic compounds, but they pose a challenge for hydrophobic compounds. Three laboratory-scale TBABs were used for the treatment of an airstream contaminated with different ratios of n-hexane and benzene mixtures. The ratios studied were 1:1, 2:1, and 1:3 n-hexane:benzene by volume. Each TBAB was operated at a pH of 4 and a temperature of 20 °C. The use of acidic-buffered nutrient solution was targeted for changing the microorganism consortium to fungi as the main biodegradation element. The experimental plan was designed to investigate the long-term performance of the TBABs with an emphasis on different mixture loading rates, removal efficiency with TBAB depth, volatile suspended solids, and carbon mass balance closure. n-Hexane loading rate was kept constant in the TBABs for comparison reasons and ranged from 4 to 22 g/(m 3 .hr). Corresponding benzene loadings ranged from 4 to 43 g/(m 3 .hr). Generally, benzene behavior in the TBAB was superior to that of n-hexane because of its higher solubility. n-Hexane showed improved performance in the 2:1 mixing ratio as compared with the other two ratios. [Box: see text].

  4. Highly Response and Sensitivity Chitosan-Polyvinyl alcohol Based Hexanal Sensors

    Directory of Open Access Journals (Sweden)

    Abd Wahab Nur Zuraihan

    2016-01-01

    Full Text Available This work is to study the sensing properties of chitosanpolyvinyl alcohol film sensors upon hexanal gas exposure using vapour sensing technique. The sensor fabrication process was done using electrochemical deposition method by deposit the sensing materials on the gold patterned electrode with chitosan/PVA. The response value of chitosan-PVA film sensors towards hexanal was taken as an output voltage using electrical testing method. In this study, 1.75% of chitosan with 5% of PVA were mixed with the ratio of (95:5 was tested upon exposure to hexanal gas. The concentration of the hexanal was varied as 10 ppm, 20 ppm, 30 ppm. It was found that the chitosan-PVA film sensors showed fast response, stable, good stability, good recovery, repeatable and good sensitivity towards hexanal exposure. The morphology of the pure chitosan and chitosan-PVA was analyzed by scanning electron microscope (SEM and the interaction between chitosan and PVA was examined by Fourier Transform Infrared Spectroscopy (FTIR. The FTIR results indicate the changes in characteristics of the spectral peaks due to the formation of the intermolecular bonds between chitosan and PVA. The SEM morphology of the composites showed flat smooth surface that be a sign of uniform distribution of chitosan and PVA mixture throughout the films.

  5. Phytochemical screening, cytotoxicity and antiviral activity of hexane fraction of Phaleria macrocarpa fruits

    Science.gov (United States)

    Ismaeel, Mahmud Yusef Yusef; Yaacob, Wan Ahmad; Tahir, Mariya Mohd.; Ibrahim, Nazlina

    2015-09-01

    Phaleria macrocarpa fruits have been widely used in the traditional medicine for the treatment of several infections. The current study was done to determine the phytochemical content, cytotoxicity and antiviral activity of the hexane fraction (HF) of P. macrocarpa fruits. In the hexane fraction of P. macarocarpa fruits, phytochemical screening showed the presence of terpenoids whereas saponins, alkaloids, tannins and anthraquinones were not present. Evaluation on Vero cell lines by using MTT assay showed that the 50% cytotoxic concentration (CC50) value was 0.48 mg/mL indicating that the fraction is not cytotoxic. Antiviral properties of the plant extracts were determined by plaque reduction assay. The effective concentration (EC50) was 0.18 mg/mL. Whereas the selective index (SI = CC50/EC50) of hexane fraction is 2.6 indicating low to moderate potential as antiviral agent.

  6. Chemical composition of the essential oil and hexanic fraction of Lippia and Lantana species

    Directory of Open Access Journals (Sweden)

    Pâmela S. Silva

    2010-11-01

    Full Text Available A comparison between two extraction approaches of volatiles compounds from six species of Verbenaceae collected at Serra do Cipó, Minas Gerais, Brazil was done. The essential oil and hexanic fraction of leaves from two Lantana and four Lippia species collected in two different seasons were analyzed by GC/MS. Among various identified compounds from both extraction methods the majority of species showed major amounts of β-caryophyllene followed by germacrene D, bicyclogermacrene and α-pinene. Few differences were observed between the composition of essential oil and the hexanic fraction regarding the two studied genera. These results suggest that the analysis of hexanic fraction can be used, as an alternative way, to analyze the volatile compounds of the essential oil.

  7. Batch extraction modeling of jatropha oil using ethanol and n-hexane

    Energy Technology Data Exchange (ETDEWEB)

    Drummond, Alessandro Araujo; Martins, Marcio Aredes [Universidade Federal de Vicosa (DEA/UFV), MG (Brazil). Dept. de Engenharia Agricola], E-mail: aredes@ufv.br; Santos, Karine Tennis dos [Universidade Federal de Vicosa (DEQ/UFV), MG (Brazil). Dept. de Quimica; Carneiro, Angelica Cassia de Oliveira [Universidade Federal de Vicosa (DFT/UFV), MG (Brazil). Dept. de Fitotecnia; Perez, Ronaldo [Universidade Federal de Vicosa (DTA/UFV), MG (Brazil). Dept. de Tecnologia de Alimentos

    2008-07-01

    Jatropha curcas (Linnaeus.) has been considered as a promising alternative for rainfall regimes from 200 to over 1500 mm per annum. The seed and the oil have many applications, such as purgative, in the treatment of skin infections and rheumatism, in the control of insects, mollusks and fungi, for diesel engines lubricants, in soap and paint production, and mainly for biodiesel production. New technologies should be developed to accomplish the oil production in large scale, since the Brazilian Biodiesel Program stimulates the oilseeds productions. In large scale oil production, the oil is obtained using solvent extraction. The solvent widely used for oil extraction is the n-hexane mainly because of its low vaporization temperature and selectivity to the lipidic fraction. However, the use of n-hexane in small capacity plants makes the process expensive because of high operating losses. Alcohols were exhaustively studied at pilot and industrial scales extraction plants. Ethanol is an efficient and advantageous extraction solvent for oilseeds, being an attractive alternative to extraction grade n-hexane. Therefore, the objective of the present work is to model and to compare the extraction kinetics of jatropha oil by using ethanol and n-hexane. Extractions experiments were performed in a batch extractor at 45 deg C using a liquid-to-solvent ratio of 15:1 (mL solvent/g sample). Samples were taken every 15 min, and extraction time was to 2 h. The kinetics of oil extraction data were fitted to the models reported in literature. For n-hexane and ethanol extractions, the fractional residual oil at 120 minutes was 0.314 and 0.0538, respectively. The models reported in literature were suitable to describe the n-hexane extraction, especially the Duggal model. However, those models were not adequate the model the ethanol extraction (author)

  8. Hexane abatement and spore emission control in a fungal biofilter-photoreactor hybrid unit

    Energy Technology Data Exchange (ETDEWEB)

    Saucedo-Lucero, J.O. [Department of Chemical Engineering and Environmental Technology, University of Valladolid, Dr. Mergelina s/n, 47011 Valladolid (Spain); IPICyT, Instituto Potosino de Investigación Científica y Tecnológica, División de Ciencias Ambientales, Camino a la Presa San José No. 2055, C.P., 78216 San Luis Potosí (Mexico); Quijano, G. [Department of Chemical Engineering and Environmental Technology, University of Valladolid, Dr. Mergelina s/n, 47011 Valladolid (Spain); Arriaga, S. [IPICyT, Instituto Potosino de Investigación Científica y Tecnológica, División de Ciencias Ambientales, Camino a la Presa San José No. 2055, C.P., 78216 San Luis Potosí (Mexico); Muñoz, R., E-mail: mutora@iq.uva.es [Department of Chemical Engineering and Environmental Technology, University of Valladolid, Dr. Mergelina s/n, 47011 Valladolid (Spain)

    2014-07-15

    Highlights: • A fungal biofilter/photoreactor was evaluated in terms of hexane and spore removal. • Biofilter supported elimination capacities of ≈35 g m{sup −3} h{sup −1} and CO{sub 2} yields of ≈75%. • The photocatalytic process slightly boosted the hexane abatement performance. • Biofilter emitted fungal spores at concentrations of 2.4 × 10{sup 3}–9.0 × 10{sup 4} CFU m{sup −3}. • Photo-assisted post-treatments resulted in spore deactivation efficiencies of 98%. - Abstract: The performance of a fungal perlite-based biofilter coupled to a post-treatment photoreactor was evaluated over 234 days in terms of n-hexane removal, emission and deactivation of fungal spores. The biofilter and photoreactor were operated at gas residence times of 1.20 and 0.14 min, respectively, and a hexane loading rate of 115 ± 5 g m{sup −3} h{sup −1}. Steady n-hexane elimination capacities of 30–40 g m{sup −3} h{sup −1} were achieved, concomitantly with pollutant mineralization efficiencies of 60–90%. No significant influence of biofilter irrigation frequency or irrigation nitrogen concentration on hexane abatement was recorded. Photolysis did not support an efficient hexane post-treatment likely due to the short EBRT applied in the photoreactor, while overall hexane removal and mineralization enhancements of 25% were recorded when the irradiated photoreactor was packed with ZnO-impregnated perlite. However, a rapid catalyst deactivation was observed, which required a periodic reactivation every 48 h. Biofilter irrigation every 3 days supported fungal spore emissions at concentrations ranging from 2.4 × 10{sup 3} to 9.0 × 10{sup 4} CFU m{sup −3}. Finally, spore deactivation efficiencies of ≈98% were recorded for the photolytic and photocatalytic post-treatment processes. This study confirmed the potential of photo-assisted post-treatment processes to mitigate the emission of hazardous fungal spores and boost the abatement performance of

  9. Fractionation of commercial hexane and use of its fractions as extracting solvent of cottonseed oil

    Directory of Open Access Journals (Sweden)

    Megahed, Ola A.

    2001-04-01

    Full Text Available The problem of producing off-graded cottonseed oil using locally produced commercial hexane as extracting solvent has explored this research. It was aimed in this work to investigate whether this problem can be solved by controlling the boiling range of the extracting solvent. Four different hexane fractions of different boiling ranges were prepared from commercial hexane. The boiling range of commercial hexane was 62-68ºC while the boiling ranges of the four fractions were 62- 64, 64-65, 65-66 and 66-68ºC. Commercial hexane and the prepared four hexane fractions were then used to extract cottonseed oil from a fixed seed sample. The five crude oil samples were then refined and bleached and their colours were measured. The results have shown that the heaviest hexane fraction ( b.r 66-68ºC produced the lightest coloured oils. The colour index of the bleached oil using this heavy cut was 190 compared to 350 using the original commercial hexane. However, the production of a commercial hexane cut having a narrow boiling range will be costly. Therefore, this research has been extended to investigate the suitability of a heavy petroleum cut which has a boiling range as wide as that of commercial hexane to extract cottonseed oil. The boiling range of this cut was 66-72ºC. The obtained results proved that the extraction of cottonseed oil using that heavy petroleum fraction produces much lighter oil than the use of conventional hexane solvent.En esta investigación se ha examinado el problema de producir aceite de semilla de algodón sin-clasificar usando hexano comercial producido localmente como disolvente. El objetivo de este trabajo fue investigar si este problema puede ser solucionado controlando el rango de ebullición del disolvente extractante. Cuatro fracciones diferentes de hexano de diversos rangos de ebullición fueron preparadas del hexano comercial. El rango al que ebullía el hexano comercial era 62-68ºC mientras que los

  10. Effects of anionic surfactant on n-hexane removal in biofilters.

    Science.gov (United States)

    Cheng, Yan; He, Huijun; Yang, Chunping; Yan, Zhou; Zeng, Guangming; Qian, Hui

    2016-05-01

    The biodegradability of three anion surfactants by biofilm microorganisms and the toxicity of the most readily biodegradable surfactant to biofilm microorganisms were examined using batch experiments, and the optimal concentration of SDS for enhanced removal of hexane was investigated using two biotrickling filters (BTFs) for comparison. Results showed that SDS could be biodegraded by microorganisms, and its toxicity to microorganisms within the experimental range was negligible. The best concentration of SDS in biofiltration of n-hexane was 0.1 CMC and the elimination capacity (EC) of 50.4 g m(-3) h(-1) was achieved at a fixed loading rate (LR) of 72 g m(-3) h(-1). When an inlet concentration of n-hexane increased from 600 to 850 mg m(-3), the removal efficiency (RE) decreased from 67% to 41% by BTF2 (with SDS) and from 52% to 42% by BTF1 (without SDS). SDS could enhance hexane removal from 43% (BTF1) to 60% (BTF2) at gas empty-bed residence time (EBRT) of 7.5 s and an inlet concentration of 200 mg m(-3). Copyright © 2016. Published by Elsevier Ltd.

  11. Effect of methanol, n-hexane and aqueous extract of Irvingia ...

    African Journals Online (AJOL)

    Bush mango leaf (Irvingia gabonensis) is commonly used locally to treat diarrhoea. The present study evaluated the anti-diarrhoea effect of this plant extract on albino rats induced with castor oil. Fresh tender leaf of this plant was collected, air-dried, powdered and percolated in n-hexane, methanol and aqueous solvents.

  12. Radiation- stimulated adsorption of n-hexane on the surface of silicon

    International Nuclear Information System (INIS)

    Hajiyeva, N.N.

    2014-01-01

    Full text : This paper presents the results of studies of radiation-stimulated adsorption of n-hexane on a silicon surface, obtained by infrared reflection-absorption spectroscopy method. It has been used a monocrystal silicon plate with high reflectance coefficient of the surface. Irradiation of the samples was carried out on gamma-quantum source of 60Co

  13. BRIONONIC ACID FROM THE HEXANE EXTRACT OF Sandoricum koetjape MERR STEM BARK (meliaceae

    Directory of Open Access Journals (Sweden)

    Tukiran Tukiran

    2010-06-01

    Full Text Available An oleane-type triterpenoid, briononic acid was isolated from hexane extract of the stem bark of Sandoricum koetjape Merr. (Meliaceae. This structure had been established based on spectroscopic data (UV, IR, and NMR and by comparison with spectroscopic data of related compound that had been reported.   Keywords: Meliaceae, Oleane, Sandoricum koetjape Merr., Triterpenoid

  14. Metabolic interaction between toluene, trichloroethylene and n-hexane in humans

    DEFF Research Database (Denmark)

    Bælum, Jesper; Mølhave, Lars; Hansen, Steen Honoré

    1998-01-01

    OBJECTIVES: This human experimental study describes the mutual metabolic interaction between toluene, trichloroethylene, and n-hexane. METHODS: Eight healthy male volunteers were exposed to combinations of toluene (1.5 or 4 mg/min), trichloroethylene (1.5 or 4 mg/min), and n-hexane (0.3 or 1.0 mg......: When the low dose rates were combined, the end exhaled concentrations were at or below the detection limit, while an increase in the dose rate of toluene increased the area under the end exhaled air concentration curve (AUC) of toluene, trichloroethylene, and n-hexane by factors of 44 (16......-117) [geometric mean and 95% confidence interval], 12.8 (4.1-40.0), and 2.2 (1.2-4.1), respectively. Trichloroethylene, in turn, increased the AUC 5.0 (1.9-13.4), 25.8 (8.2-80.8) and 2.9 (1.6-5.4), respectively, whereas the corresponding values for n-hexane were 1.9 (0.7-5.1), 1.5 (0.5-4.6), and 3.2 (1...

  15. Communication: Molecular dynamics and {sup 1}H NMR of n-hexane in liquid crystals

    Energy Technology Data Exchange (ETDEWEB)

    Weber, Adrian C. J., E-mail: WeberA@BrandonU.CA [Chemistry Department, Brandon University, 270-18th Street, Brandon, Manitoba R7A 6A9 (Canada); Burnell, E. Elliott, E-mail: elliott.burnell@ubc.ca [Chemistry Department, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z1 (Canada); Meerts, W. Leo, E-mail: leo.meerts@science.ru.nl [Radboud University, Institute for Molecules and Materials, Heyendaalseweg 135, NL-6525 AJ Nijmegen (Netherlands); Atomic, Molecular and Laser Physics, Vrije Universiteit, De Boelelaan 1081, 1081 HV Amsterdam (Netherlands); Lange, Cornelis A. de, E-mail: c.a.de.lange@vu.nl [Atomic, Molecular and Laser Physics, Vrije Universiteit, De Boelelaan 1081, 1081 HV Amsterdam (Netherlands); Dong, Ronald Y., E-mail: rondong@phas.ubc.ca [Department of Physics and Astronomy, University of British Columbia, 6224 Agricultural Road, Vancouver, British Columbia V6T 1Z1 (Canada); Muccioli, Luca, E-mail: Luca.Muccioli@unibo.it; Pizzirusso, Antonio, E-mail: Antonio.Pizzirusso80@gmail.com; Zannoni, Claudio, E-mail: Claudio.Zannoni@unibo.it [Dipartimento di Chimica Industriale “Toso Montanari,” Università di Bologna and INSTM, viale Risorgimento 4, 40136 Bologna (Italy)

    2015-07-07

    The NMR spectrum of n-hexane orientationally ordered in the nematic liquid crystal ZLI-1132 is analysed using covariance matrix adaptation evolution strategy (CMA-ES). The spectrum contains over 150 000 transitions, with many sharp features appearing above a broad, underlying background signal that results from the plethora of overlapping transitions from the n-hexane as well as from the liquid crystal. The CMA-ES requires initial search ranges for NMR spectral parameters, notably the direct dipolar couplings. Several sets of such ranges were utilized, including three from MD simulations and others from the modified chord model that is specifically designed to predict hydrocarbon-chain dipolar couplings. In the end, only inaccurate dipolar couplings from an earlier study utilizing proton-proton double quantum 2D-NMR techniques on partially deuterated n-hexane provided the necessary estimates. The precise set of dipolar couplings obtained can now be used to investigate conformational averaging of n-hexane in a nematic environment.

  16. Gastro-protective effect of crude hexane leaf extract of Sesamum ...

    African Journals Online (AJOL)

    The gastroprotective effect of the hexane extract of the leaves of Sesamum indicum (HESI) was investigated in twenty-eight male rabbits. Gastroprotective activity against necrotizing agent induced ulceration was studied. Gastric wall mucus was determined by standard methods. Anti-secretory activity was determined in ...

  17. Decomposition of multilayer benzene and n-hexane films on vanadium.

    Science.gov (United States)

    Souda, Ryutaro

    2015-09-21

    Reactions of multilayer hydrocarbon films with a polycrystalline V substrate have been investigated using temperature-programmed desorption and time-of-flight secondary ion mass spectrometry. Most of the benzene molecules were dissociated on V, as evidenced by the strong depression in the thermal desorption yields of physisorbed species at 150 K. The reaction products dehydrogenated gradually after the multilayer film disappeared from the surface. Large amount of oxygen was needed to passivate the benzene decomposition on V. These behaviors indicate that the subsurface sites of V play a role in multilayer benzene decomposition. Decomposition of the n-hexane multilayer films is manifested by the desorption of methane at 105 K and gradual hydrogen desorption starting at this temperature, indicating that C-C bond scission precedes C-H bond cleavage. The n-hexane dissociation temperature is considerably lower than the thermal desorption temperature of the physisorbed species (140 K). The n-hexane multilayer morphology changes at the decomposition temperature, suggesting that a liquid-like phase formed after crystallization plays a role in the low-temperature decomposition of n-hexane.

  18. Activity of the main fatty acid components of the hexane leaf extract ...

    African Journals Online (AJOL)

    The composition of hexane leaf extract of Ricinus communis was determined by gas chromatography– mass spectrometry (GC-MS) to contain four fatty acids: linolenic acid (47.76%), linoleic acid (15.28%), palmitic acid (13.01%), and stearic acid (1.73%). The insectistatic and insecticidal activities of the two major ...

  19. Proteomic analysis reveals resistance mechanism against biofuel hexane in Synechocystis sp. PCC 6803

    Directory of Open Access Journals (Sweden)

    Liu Jie

    2012-09-01

    Full Text Available Abstract Background Recent studies have demonstrated that photosynthetic cyanobacteria could be an excellent cell factory to produce renewable biofuels and chemicals due to their capability to utilize solar energy and CO2 as the sole energy and carbon sources. Biosynthesis of carbon-neutral biofuel alkanes with good chemical and physical properties has been proposed. However, to make the process economically feasible, one major hurdle to improve the low cell tolerance to alkanes needed to be overcome. Results Towards the goal to develop robust and high-alkane-tolerant hosts, in this study, the responses of model cyanobacterial Synechocystis PCC 6803 to hexane, a representative of alkane, were investigated using a quantitative proteomics approach with iTRAQ - LC-MS/MS technologies. In total, 1,492 unique proteins were identified, representing about 42% of all predicted protein in the Synechocystis genome. Among all proteins identified, a total of 164 and 77 proteins were found up- and down-regulated, respectively. Functional annotation and KEGG pathway enrichment analyses showed that common stress responses were induced by hexane in Synechocystis. Notably, a large number of transporters and membrane-bound proteins, proteins against oxidative stress and proteins related to sulfur relay system and photosynthesis were induced, suggesting that they are possibly the major protection mechanisms against hexane toxicity. Conclusion The study provided the first comprehensive view of the complicated molecular mechanism employed by cyanobacterial model species, Synechocystis to defend against hexane stress. The study also provided a list of potential targets to engineer Synechocystis against hexane stress.

  20. Acquired Color Vision Defects and Hexane Exposure: A Study of San Francisco Bay Area Automotive Mechanics.

    Science.gov (United States)

    Beckman, Stella; Eisen, Ellen A; Bates, Michael N; Liu, Sa; Haegerstrom-Portnoy, Gunilla; Hammond, S Katharine

    2016-06-01

    Occupational exposure to solvents, including n-hexane, has been associated with acquired color vision defects. Blue-yellow defects are most common and may be due to neurotoxicity or retinal damage. Acetone may potentiate the neurotoxicity of n-hexane. We present results on nonhexane solvent and hexane exposure and color vision from a cross-sectional study of 835 automotive repair workers in the San Francisco Bay Area, California (2007-2013). Cumulative exposure was estimated from self-reported work history, and color vision was assessed using the Lanthony desaturated D-15 panel test. Log-binomial regression was used to estimate prevalence ratios for color vision defects. Acquired color vision defects were present in 29% of participants, of which 70% were blue-yellow. Elevated prevalence ratios were found for nonhexane solvent exposure, with a maximum of 1.31 (95% confidence interval (CI): 0.86, 2.00) for blue-yellow. Among participants aged ≤50 years, the prevalence ratio for blue-yellow defects was 2.17 (95% CI: 1.03, 4.56) in the highest quartile of nonhexane solvent exposure and 1.62 (95% CI: 0.97, 2.72) in the highest category of exposure to hexane with acetone coexposure. Cumulative exposures to hexane and nonhexane solvents in the highest exposure categories were associated with elevated prevalence ratios for color vision defects in younger participants. © The Author 2016. Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of Public Health. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  1. Effect of Pressure on Absorption Spectra of Lycopene in n-Hexane and CS2 Solvents

    Science.gov (United States)

    Zhang, Wei; Liu, Wei-Long; Zheng, Zhi-Ren; Huo, Ming-Ming; Li, Ai-Hua; Yang, Bin

    2010-01-01

    The absorption spectra of lycopene in n-hexane and CS2 are measured under high pressure and the results are compared with β-carotene. In the lower pressure range, the deviation from the linear dependence on the Bayliss parameter (BP) for β-carotene is more visible than that for lycopene. With the further increase of the solvent BP, the 0-0 bands of lycopene and β-carotene red shift at almost the same rate in n-hexane; however, the 0-0 band of lycopene red shifts slower than that of β-carotene in CS2. The origins of these diversities are discussed taking into account the dispersion interactions and structures of solute and solvent molecules.

  2. Effect of Pressure on Absorption Spectra of Lycopene in n-Hexane and CS2 Solvents

    International Nuclear Information System (INIS)

    Wei, Zhang; Wei-Long, Liu; Zhi-Ren, Zheng; Ming-Ming, Huo; Ai-Hua, Li; Bin, Yang

    2010-01-01

    The absorption spectra of lycopene in n-hexane and CS 2 are measured under high pressure and the results are compared with β-carotene. In the lower pressure range, the deviation from the linear dependence on the Bayliss parameter (BP) for β-carotene is more visible than that for lycopene. With the further increase of the solvent BP, the 0–0 bands of lycopene and β-carotene red shift at almost the same rate in n-hexane; however, the 0–0 band of lycopene red shifts slower than that of β-carotene in CS 2 . The origins of these diversities are discussed taking into account the dispersion interactions and structures of solute and solvent molecules. (atomic and molecular physics)

  3. Density and temperature effects on electron mobilities in gaseous, critical and liquid n-hexane, cyclohexane, and cyclopentane

    International Nuclear Information System (INIS)

    Huang, S.S.-S.; Freeman, G.R.

    1978-01-01

    In the low density vapors the density normalized mobilities μn of thermal electrons decreased in the order n-hexane > cyclopentane > cyclohexane. Mobilities in the critical fluids were 16 cm 2 /V s in n-hexane, 23 in cyclohexane, and 22 in cyclopentane. Mobilities in the liquids were independent of field up to the highest value used, which was 1.5 Td in the hexanes and 0.9 Td in cyclopentane. The mobilities and their temperature dependences were interpreted in terms of a model

  4. Comparative study of the radiolysis and photolysis of the hexane solutions of polychlorobiphenyls

    International Nuclear Information System (INIS)

    Abdullayev, E.T.; Gurbanov, M.A.; Jamalov, P.J.

    2015-01-01

    Model solutions of polychlorobiphenyls, containing 12 congeners in hexane were irradiated by γ-rays at 14-140 kGy absorption doses, as well as by UV-rays for 2-30 minutes using middle pressure mercury lamp (PRK-4, λ=253†546 nm), and the kinetics of the radiolytic PCBs degradation processes was investigated. The PCBs identification using a Gas Chromatography (Agilent Technologies 7820A)

  5. Solubility of Methane in the Mixture of Ethanol+Hexane at High Pressures

    Institute of Scientific and Technical Information of China (English)

    华超; 马沛生; 夏淑倩; 白鹏

    2005-01-01

    Solubility data were first presented for methane in the mixture of ethanol-hexane at temperatures from 291.15K to 318.15K and pressures up to 12.00MPa. The experimental data were correlated by PR and PRSV equations of state with rms errors of about 0.051. The A-K and Y-W-A-K models were both used to estimate liquid molar volume under high pressure. The results were satisfactory.

  6. Influence of activated carbon characteristics on toluene and hexane adsorption: Application of surface response methodology

    Science.gov (United States)

    Izquierdo, Mª Teresa; de Yuso, Alicia Martínez; Valenciano, Raquel; Rubio, Begoña; Pino, Mª Rosa

    2013-01-01

    The objective of this study was to evaluate the adsorption capacity of toluene and hexane over activated carbons prepared according an experimental design, considering as variables the activation temperature, the impregnation ratio and the activation time. The response surface methodology was applied to optimize the adsorption capacity of the carbons regarding the preparation conditions that determine the physicochemical characteristics of the activated carbons. The methodology of preparation produced activated carbons with surface areas and micropore volumes as high as 1128 m2/g and 0.52 cm3/g, respectively. Moreover, the activated carbons exhibit mesoporosity, ranging from 64.6% to 89.1% the percentage of microporosity. The surface chemistry was characterized by TPD, FTIR and acid-base titration obtaining different values of surface groups from the different techniques because the limitation of each technique, but obtaining similar trends for the activated carbons studied. The exhaustive characterization of the activated carbons allows to state that the measured surface area does not explain the adsorption capacity for either toluene or n-hexane. On the other hand, the surface chemistry does not explain the adsorption results either. A compromise between physical and chemical characteristics can be obtained from the appropriate activation conditions, and the response surface methodology gives the optimal activated carbon to maximize adsorption capacity. Low activation temperature, intermediate impregnation ratio lead to high toluene and n-hexane adsorption capacities depending on the activation time, which a determining factor to maximize toluene adsorption.

  7. Inhalation developmental toxicology studies: Teratology study of n-hexane in mice: Final report

    Energy Technology Data Exchange (ETDEWEB)

    Mast, T.J.; Decker, J.R.; Stoney, K.H.; Westerberg, R.B.; Evanoff, J.J.; Rommereim, R.L.; Weigel, R.J.

    1988-05-01

    Gestational exposure to n-hexane resulted in an increase in the number of resorbed fetuses for exposure groups relative to the control group; however, the increases were not directly correlated to exposure concentration. The differences were statistically significant for the 200-ppM with respect to total intrauterine death (early plus late resorptions), and with respect to late resorptions for the 5000-ppM group. A small, but statistically significant, reduction in female (but not male) fetal body weight relative to the control group was observed at the 5000-ppM exposure level. There were no exposure-related increases in any individual fetal malformation or variation, nor was there any increase in the incidence of combined malformations or variations. Gestational exposure of CD-1 mice to n-hexane vapors appeared to cause a degree of concentration-related developmental toxicity in the absence of overt maternal toxicity, but the test material was not found to be teratogenic. This developmental toxicity was manifested as an increase in the number of resorptions per litter for all exposure levels, and as a decrease in the uterine: extra-gestational weight gain ratio at the 5000-ppM exposure level. Because of the significant increase in the number of resorptions at the 200-ppM exposure level, a no observable effect level (NOEL) for developmental toxicity was not established for exposure of mice to 200, 1000 or 5000-ppM n-hexane vapors. 21 refs., 3 figs., 9 tabs.

  8. Hydropyrolysis of n-Hexane and Toluene to Acetylene in Rotating-Arc Plasma

    Directory of Open Access Journals (Sweden)

    Jie Ma

    2017-07-01

    Full Text Available Thermal plasma pyrolysis is a powerful technology for converting waste or low-value materials to valuable gaseous hydrocarbons. This paper presents for the first time the hydropyrolysis of n-hexane and toluene in a rotating-arc plasma reactor. Effects of the mole ratio of H/C in the feed, power input and magnetic induction were investigated to evaluate the reaction performance. A lower H/C ratio could lead to a lower yield of C2H2 and lower specific energy consumption, and there existed an optimum range of power input for both n-hexane and toluene pyrolysis within the investigated range. The yield of C2H2 in n-hexane and toluene pyrolysis could reach 85% and 68%, respectively, with respective specific energy consumption (SEC of 13.8 kWh/kg·C2H2 and 19.9 kWh/kg·C2H2. Compared with the results reported in literature, the rotating-arc plasma process showed higher C2H2 yield and lower energy consumption, which is attributed to the better initial mixing of the reactant with the hot plasma gas and the more uniform temperature distribution.

  9. Comparison of Analgesic and Hypoglycemic Effect of Hexanic and Alcohlic Extract of Fenugreek Seed in Male Diabetic Rats

    Directory of Open Access Journals (Sweden)

    Sima Nasri

    2013-04-01

    Full Text Available Background & Objectives: Diabetes mellitus is recognized with severe metabolic complications. Many herbal medicines have been recommended for treatment of diabetes. In this study, the antidiabetic and analgesic effect of hexanic and alcohlic extract Trigonella-foenum graecum was investigated in normal and streptozotocin-induced diabetic rats.  Methods: Present study was carried out in 2011 at Guilan University of Medical Sciences, 48 male Sprague Dawley rats (230-300 gr were divided into six groups: control, type 1 diabetic, and 4 treat ed groups that received intraperitonealy hexanic and alcoholic extract of fenugreek (100, 200 mg/kg body weight for 28 days. Two experimental models were used (acetic acid, and hot-plate tests in order to characterize the analgesic effect. Blood glucose was measured with glucometer. Data analyzed with spss software 16 and one way ANOVA and Tukey tests. P<0.05 was statistically significant.  Results: Compared to control rats, both of the aqueous - alcoholic and Hexan ic extract significantly reduced blood glucose level in all diabetics groups. This effect was stronger in groups that received Hexanic extract (p<0.05 . All groups received the aqueous - alcoholic and Hexan ic extract showed analgesic effect but this effect was more clear in the Hexanic 200 mg/kg group (p<0.05.  Conclusion: Fenugreek extract possesses hypoglycemic , and analgesic effects .

  10. N-hexane neuropathy with vertigo and cold allodynia in a silk screen printer: A case study.

    Science.gov (United States)

    Pradhan, Sunil; Tandon, Ruchika

    2015-01-01

    N-hexane neuropathy is an occupational disease caused by exposure to n-hexane, which is used as a solvent in silk screen printing. Here, we describe a 35-year-old man, a silk screen printer by profession, who presented with dizziness, distal swelling of both lower limbs for 10 months and tingling and burning sensation in both feet for 9.5 months along with cold allodynia. The patient had normal results of a motor and sensory system examination, apart from an impaired temperature sense. Nerve conduction tests showed a conduction block in bilateral common peroneal nerves and absence of conduction in bilateral sural nerves. These symptoms resolved when further exposure to n-hexane was ceased but cold allodynia remained. Thus, cold allodynia and impaired temperature sense can be a manifestation of n-hexane neuropathy. Hence, abnormalities on nerve conduction studies can be detected in n-hexane neuropathy patients, even before clinical examination detects any such abnormalities. In the case of the patients presenting with sensory motor neuropathy, history of occupational exposure to n-hexane becomes important, as the sooner the disease is detected, the better the chances of recovery. This work is available in Open Access model and licensed under a CC BY-NC 3.0 PL license.

  11. N-hexane neuropathy with vertigo and cold allodynia in a silk screen printer: A case study

    Directory of Open Access Journals (Sweden)

    Sunil Pradhan

    2015-10-01

    Full Text Available N-hexane neuropathy is an occupational disease caused by exposure to n-hexane, which is used as a solvent in silk screen printing. Here, we describe a 35-year-old man, a silk screen printer by profession, who presented with dizziness, distal swelling of both lower limbs for 10 months and tingling and burning sensation in both feet for 9.5 months along with cold allodynia. The patient had normal results of a motor and sensory system examination, apart from an impaired temperature sense. Nerve conduction tests showed a conduction block in bilateral common peroneal nerves and absence of conduction in bilateral sural nerves. These symptoms resolved when further exposure to n-hexane was ceased but cold allodynia remained. Thus, cold allodynia and impaired temperature sense can be a manifestation of n-hexane neuropathy. Hence, abnormalities on nerve conduction studies can be detected in n-hexane neuropathy patients, even before clinical examination detects any such abnormalities. In the case of the patients presenting with sensory motor neuropathy, history of occupational exposure to n-hexane becomes important, as the sooner the disease is detected, the better the chances of recovery.

  12. Use of a plant-derived enzyme template for the production of the green-note volatile hexanal.

    Science.gov (United States)

    Schade, Frank; Thompson, John E; Legge, Raymond L

    2003-11-05

    Hexanal is a key organoleptic element of green-note that is found in both fragrances and flavors. We report a novel process for the production of hexanal using immobilized enzyme templates extracted from different plant sources in combination with hollow-fiber ultrafiltration for in situ separation. Enzyme templates, known to be responsible for the synthesis of hexanal from linoleic acid (18:2), were isolated from naturally enriched tissues including carnation petals, strawberry and tomato leaves. These templates were immobilized in an alginate matrix and used as a biocatalyst in a packed-bed bioreactor. Continuous product recovery was achieved using a hollow-fiber ultrafiltration unit. The effects of pH, reaction temperature, and substrate and enzyme concentrations were studied and their effects on hexanal generation identified and optimized. Utilizing optimized conditions, hexanal production 112-fold higher than endogenous steady-state levels in a corresponding amount of plant tissue could be achieved over a 30-minute period. Based on the reactor studies, product inhibition also appears to be an important factor for bioreactor-based hexanal production. Copyright 2003 Wiley Periodicals, Inc.

  13. The growth of aligned carbon nanotubes on quartz substrate by spray pyrolysis of hexane

    International Nuclear Information System (INIS)

    Sadeghian, Zahra

    2008-01-01

    Vertically aligned multiwall carbon nanotubes were grown by spray pyrolysis of hexane as the carbon source in the presence of ferrocene as catalyst precursor on a quartz substrate. In recent work we used optimal experimental parameters for the feeding method, reactor conditions, reaction temperature and time, concentration of catalyst and flow rate of feed and gas. The process parameters were chosen so as to obtain multiwall carbon nanotubes and aligned multiwall carbon nanotubes. The tubes are around 15-80 nm in diameter. The morphology and structure of the samples were characterized by x-ray diffraction, Raman spectroscopy, scanning electron microscopy, and transmission electron microscopy analyses

  14. Thermotropic phase transition in an adsorbed melissic acid film at the n-hexane-water interface

    Science.gov (United States)

    Tikhonov, A. M.

    2017-06-01

    A reversible thermotropic phase transition in an adsorption melissic acid film at the interface between n-hexane and an aqueous solution of potassium hydroxide (pH ≈ 10) is investigated by X-ray reflectometry and diffuse scattering using synchrotron radiation. The experimental data indicate that the interface "freezing" transition is accompanied not only by the crystallization of the Gibbs monolayer but also by the formation of a planar smectic structure in the 300-Å-thick adsorption film; this structure is formed by 50-Å-thick layers.

  15. icacy test of hexane extract of Annona squamosa L seeds for Chrysomya bezziana larvae growth in vitro

    Directory of Open Access Journals (Sweden)

    April H Wardhana

    2004-12-01

    Full Text Available Chrysomya bezziana is primer agent causing myiasis in livestock and human throughout Africa to Asia. At present, treatment of myiasis using chemical synthetic insecticide causing environment and livestock production contaminations. The aim of this study was to evaluate the effect of hexane extract of Annona squamosa L seed to kill C. bezziana as botanical insecticide. Three level and method preparation of larvae (L1, L2 and L3 were carried out. Meat blood mixture (MBM and larval rearing media (LRM were mixed with hexane extract of A. squamosa L seed and tested to 625 and 750 larvae (L1and L2 respectively, while for L3 625 larvae were soaked in the solution containing the hexane extract. This last preparation was carried out to observe the effect of toxic contact. Each larvae treatment was divided into 5 levels such as negative control using distillation water (PO, given 0.25% hexane extract (P I; 0.50% (P II; 0.75% (P III and positive control was given with 0.10% Asuntol®. This assay was to know digest toxic effect of hexane extract of A. squamosa L seed for those larvae. Number of 625 instar III larvae (L3 was soaked in the solution containing the hexane extract of A. squamosa L seed for 10 second, placed into vermicullite and incubated on 36oC. This assay was to know contact toxic effect of them. All of larvae were allowed to become pupae. Parameters oberserve were number of larvae death, pupae weight and number of pupae become into fly. The data was analyzed using Anova (5% and Z test (5% then smallest significant difference test (BNT 5%. The results showed that 0.50% of hexane extract of A. squamosa L seed was able to decrease pupae weight for L1 and L2 and to cause fail pupae become fly (P0.05.

  16. Antimicrobial activities of essential oil and hexane extract of Florence fennel [Foeniculum vulgare var. azoricum (Mill.) Thell.] against foodborne microorganisms.

    Science.gov (United States)

    Cetin, Bülent; Ozer, Hakan; Cakir, Ahmet; Polat, Taşkin; Dursun, Atilla; Mete, Ebru; Oztürk, Erdoğan; Ekinci, Melek

    2010-02-01

    The objective of this study was to determine the chemical compositions of the essential oil and hexane extract isolated from the inflorescence, leaf stems, and aerial parts of Florence fennel and the antimicrobial activities of the essential oil, hexane extract, and their major component, anethole, against a large variety of foodborne microorganisms. Gas chromatography and gas chromatography-mass spectrometry analysis showed that the essential oils obtained from inflorescence, leaf stems, and whole aerial parts contained (E)-anethole (59.28-71.69%), limonene (8.30-10.73%), apiole (trace to 9.23%), beta-fenchyl acetate (3.02-4.80%), and perillene (2.16-3.29%) as the main components. Likewise, the hexane extract of the plant sample exhibited a similar chemical composition, and it contained (E)-anethole (53.00%), limonene (27.16%), gamma-terpinene (4.09%), and perillene (3.78%). However, the hexane extract also contained less volatile components such as n-hexadecanoic acid (1.62%), methyl palmitate (1.17%), and linoleic acid (1.15%). The in vitro antimicrobial assays showed that the essential oil, anethole, and hexane extract were effective against most of the foodborne pathogenic, saprophytic, probiotic, and mycotoxigenic microorganisms tested. The results of the present study revealed that (E)-anethole, the main component of Florence fennel essential oil, is responsible for the antimicrobial activity and that the essential oils as well as the hexane extract can be used as a food preservative. This study is the first report showing the antimicrobial activities of essential oil and hexane extract of Florence fennel against probiotic bacteria.

  17. Normalized fluctuations, H2O vs n-hexane: Site-correlated percolation

    Science.gov (United States)

    Koga, Yoshikata; Westh, Peter; Sawamura, Seiji; Taniguchi, Yoshihiro

    1996-08-01

    Entropy, volume and the cross fluctuations were normalized to the average volume of a coarse grain with a fixed number of molecules, within which the local and instantaneous value of interest is evaluated. Comparisons were made between liquid H2O and n-hexane in the range from -10 °C to 120 °C and from 0.1 MPa to 500 MPa. The difference between H2O and n-hexane in temperature and pressure dependencies of these normalized fluctuations was explained in terms of the site-correlated percolation theory for H2O. In particular, the temperature increase was confirmed to reduce the hydrogen bond probability, while the pressure appeared to have little effect on the hydrogen bond probability. According to the Le Chatelier principle, however, the putative formation of ``ice-like'' patches at low temperatures due to the site-correlated percolation requirement is retarded by pressure increases. Thus, only in the limited region of low pressure (<300 MPa) and temperature (<60 °C), the fluctuating ice-like patches are considered to persist.

  18. High Pressure Vapor-Liquid Equilibrium of Supercritical Carbon Dioxide + n-Hexane System

    Institute of Scientific and Technical Information of China (English)

    YU Jinglin; TIAN Yiling; ZHU Rongjiao; LIU Zhihua

    2006-01-01

    Vapor-liquid equilibrium data of supercritical carbon dioxide + n-hexane system were measured at 313.15 K,333.15 K,353.15 K,and 373.15 K and their molar volumes and densities were measured both in the subcritical and supercritical regions ranging from 2.15 to 12.63 MPa using a variable-volume autoclave.The thermodynamic properties including mole fractions,densities,and molar volumes of the system were calculated with an equation of state by Heilig and Franck,in which a repulsion term and a square-well potential attraction term for intermolecular interaction was used.The pairwise combination rule was used to calculate the square-well molecular interaction potential and three adjustable parameters (ω,kε,kσ) were obtained.The Heilig-Franck equation of state is found to have good correlation with binary vapor-liquid equilibrium data of the carbon dioxide + n-hexane system.

  19. Radiolysis of fatty acid esters in n-hexane solution in an atmosphere of nitrogen

    International Nuclear Information System (INIS)

    Kimura, Kazuo; Shirai, Kazuo

    1975-01-01

    There have been several problems in food preservation by irradiation. Deterioration of food components by irradiation is one of the most substantial subjects. This investigation was undertaken as a basic experiment to discuss the radiolysis of lipids in food irradiation. In the previous paper, radiolytic examination on six of methyl esters of fatty acids in n-hexane solution in the presence of air was reported. In the present work the same samples-methyl stearate (C sub(18:0)), methyl oleate (C sub(18:1)), methyl linoleate (C sub(18:2)), methyl linolenate (C sub(18:3)), methyl arachidate (C sub(20:0)) and methyl arachidonate (C sub(20:4)) were examined in an atmosphere of nitrogen. Samples in n-hexane solution were sealed in glass ampules after substituted with nitrogen. Preparations were treated with 60 Co-gamma-radiation at dose from 1.8 x 10 6 to 7.1 x 10 6 rads. These preparations were analyzed by gas chromatography, infrared spectrophotometry and iodine value determination. The results were as follows: 1. Generally speaking saturated acids were stable and unsaturated were unstable. 2. In unsaturated series, the high unsaturated fatty acids were more labile to gamma-irradiation and the more increased doses induced the more drastic decompositions. 3. It was observed by infrared spectra that some isomerization from cis to trans configuration occured at double bond systems in unsaturated fatty acids. (auth.)

  20. Biodiesel from wet microalgae: extraction with hexane after the microwave-assisted transesterification of lipids.

    Science.gov (United States)

    Cheng, Jun; Huang, Rui; Li, Tao; Zhou, Junhu; Cen, Kefa

    2014-10-01

    A chloroform-free novel process for the efficient production of biodiesel from wet microalgae is proposed. Crude biodiesel is produced through extraction with hexane after microwave-assisted transesterification (EHMT) of lipids in wet microalgae. Effects of different parameters, including reaction temperature, reaction time, methanol dosage, and catalyst dosage, on fatty acids methyl esters (FAMEs) yield are investigated. The yield of FAME extracted into the hexane from the wet microalgae is increased 6-fold after the transesterification of lipids. The yield of FAME obtained through EHMT of lipids in wet microalgae is comparable to that obtained through direct transesterification of dried microalgae biomass with chloroform; however, FAME content in crude biodiesel obtained through EHMT is 86.74%, while that in crude biodiesel obtained through the chloroform-based process is 75.93%. EHMT ensures that polar pigments present in microalgae are not extracted into crude biodiesel, which leads to a 50% reduction in nitrogen content in crude biodiesel. Copyright © 2014 Elsevier Ltd. All rights reserved.

  1. A Mesopore-Dependent Catalytic Cracking of n-Hexane Over Mesoporous Nanostructured ZSM-5.

    Science.gov (United States)

    Qamar, M; Ahmed, M I; Qamaruddin, M; Asif, M; Sanhoob, M; Muraza, O; Khan, M Y

    2018-08-01

    Herein, pore size, crystalinity, and Si/Al ratio of mesoporous ZSM-5 (MFI) nanocrystals was controlled by synthesis parameters, such as surfactant concentration ([3-(trimethoxysilyl)propyl] hexa-decyl dimethyl ammonium chloride), sodium hydroxide concentrations, synthesis temperature and time. The morphology, surface structure and composition of the MFI particles was systematically investigated. More notably, the mesopore-dependent catalytic activity of ZSM-5 was evaluated by studying the cracking of n-hexane. The findings suggest the porosity has pronounced impact on the catalytic activity, selectivity and stability of ZSM-5 nanocrystals. Critical surface attributes such as nature of acid sites (Brønsted and Lewis), concentration, and strength are obtained by the infrared study of adsorbed probe molecules (pyridine) and the temperature programmed desorption. In spite of being weaker in Si/Al ratio or acidic strength, mesoporous catalysts showed more stable and efficient cracking of n-hexane suggesting that acidity seems not the predominant factor operative in the activity, selectivity and stability.

  2. Inhalation reproductive toxicology studies: Male dominant lethal study of n-hexane in Swiss (CD-1) mice: Final report

    Energy Technology Data Exchange (ETDEWEB)

    Mast, T.J.; Rommereim, R.L.; Evanoff, J.J.; Sasser, L.B.; Decker, J.R.; Stoney, K.H.; Weigel, R.J.; Westerberg, R.B.

    1988-08-01

    The straight-chain hydrocarbon, n-hexane, is a volatile, ubiquitous solvent routinely used in industrial environments; consequently, the opportunity for industrial, environmental or accidental exposure to hexane vapors is significant. Although myelinated nerve tissue is the primary target organ of hexane, the testes have also been identified as being sensitive to hexacarbon exposure. The objective of this study was to evaluate male dominant lethal effects in Swiss (CD-1) mice after exposure to 0, 200, 1000, or 5000 ppM n-hexane, 20 h/day for 5 consecutive days. Each exposure concentration consisted of 30 randomly selected, proven male breeders; 4 groups. The mice were weighed just prior to the first day of exposure and at weekly intervals until sacrifice. Ten males in each dose group were sacrificed one day after the cessation of exposure, and their testes and epididymides were removed for evaluation of the germinal epithelium. The remaining male mice, 20 per group, were individually housed in hanging wire-mesh breeding cages where they were mated with unexposed, virgin females for eight weekly intervals; new females were provided each week. The mated females were sacrificed 12 days after the last day of cohabitation and their reproductive status and the number and viability of the implants were recorded. The appearance and behavior of the male mice were unremarkable throughout the study period and no evidence of n-hexane toxicity was observed. 18 refs., 3 figs., 11 tabs.

  3. Inhalation reproductive toxicology studies: Male dominant lethal study of n-hexane in Swiss (CD-1) mice: Final report

    International Nuclear Information System (INIS)

    Mast, T.J.; Rommereim, R.L.; Evanoff, J.J.; Sasser, L.B.; Decker, J.R.; Stoney, K.H.; Weigel, R.J.; Westerberg, R.B.

    1988-08-01

    The straight-chain hydrocarbon, n-hexane, is a volatile, ubiquitous solvent routinely used in industrial environments; consequently, the opportunity for industrial, environmental or accidental exposure to hexane vapors is significant. Although myelinated nerve tissue is the primary target organ of hexane, the testes have also been identified as being sensitive to hexacarbon exposure. The objective of this study was to evaluate male dominant lethal effects in Swiss (CD-1) mice after exposure to 0, 200, 1000, or 5000 ppM n-hexane, 20 h/day for 5 consecutive days. Each exposure concentration consisted of 30 randomly selected, proven male breeders; 4 groups. The mice were weighed just prior to the first day of exposure and at weekly intervals until sacrifice. Ten males in each dose group were sacrificed one day after the cessation of exposure, and their testes and epididymides were removed for evaluation of the germinal epithelium. The remaining male mice, 20 per group, were individually housed in hanging wire-mesh breeding cages where they were mated with unexposed, virgin females for eight weekly intervals; new females were provided each week. The mated females were sacrificed 12 days after the last day of cohabitation and their reproductive status and the number and viability of the implants were recorded. The appearance and behavior of the male mice were unremarkable throughout the study period and no evidence of n-hexane toxicity was observed. 18 refs., 3 figs., 11 tabs

  4. Molecular dynamics studies of the melting of butane and hexane monolayers adsorbed on the basal-plane surface of graphite

    DEFF Research Database (Denmark)

    Hansen, Flemming Yssing; Newton, J. C.; Taub, H.

    1993-01-01

    The effect of molecular steric properties on the melting of quasi-two-dimensional solids is investigated by comparing results of molecular dynamics simulations of the melting of butane and hexane monolayers adsorbed on the basal-plane surface of graphite. These molecules differ only in their length......, being members of the n-alkane series [CH3(CH2)n−2CH3] where n=4 for butane and n=6 for hexane. The simulations employ a skeletal model, which does not include the hydrogen atoms explicitly, to represent the intermolecular and molecule–substrate interactions. Nearest-neighbor intramolecular bonds...... are fixed in length, but the molecular flexibility is preserved by allowing the bend and dihedral torsion angles to vary. The simulations show a qualitatively different melting behavior for the butane and hexane monolayers consistent with neutron and x-ray scattering experiments. The melting of the low...

  5. Isothermal (vapour + liquid) equilibrium data for binary systems of (n-hexane + CO2 or CHF3)

    International Nuclear Information System (INIS)

    Williams-Wynn, Mark D.; Naidoo, Paramespri; Ramjugernath, Deresh

    2016-01-01

    Highlights: • (Static-analytic + static-synthetic) phase equilibrium measurements. • Binary VLE data for (CO 2 + n-hexane) and (trifluoromethane + n-hexane). • Thermodynamic models were fitted to the experimental data. • Liquid–liquid immiscibility occurred with (trifluoromethane + n-hexane) system. - Abstract: The (vapour + liquid) equilibrium (VLE) was measured for the (carbon dioxide + n-hexane) binary system at temperatures between T = (303.1 and 323.1) K. In addition, VLE and (vapour + liquid + liquid) equilibria (VLLE) were determined for the (trifluoromethane + n-hexane) binary system at temperatures between T = (272.9 and 313.3) K and pressures in the range of P = (1.0 to 5.7) MPa. Measurements were undertaken in a static-analytic apparatus, with verification of experimental values undertaken using a static-synthetic equilibrium cell to measure bubble point pressures at several compositions. The phase equilibrium results were modelled with the Peng–Robinson equation of state with the Mathias–Copeman alpha function, coupled with the Wong–Sandler mixing rules. Regression of the data was performed with the NRTL and the UNIQUAC activity coefficient models with the Wong–Sandler mixing rules, and the performance of the models was compared. Critical loci for both systems were estimated, using the calculation procedures of Ungerer et al. and Heidemann and Khalil. For the (trifluoromethane + n-hexane) system, liquid–liquid immiscibility was experienced at the lowest temperature measured (T = 272.9 K). At higher temperatures, no immiscibility was visible during the measurements; however, the models continued to predict a miscibility gap.

  6. Hydro-isomerization of n-hexane on bi-functional catalyst: Effect of total and hydrogen partial pressures

    Science.gov (United States)

    Thoa, Dao Thi Kim; Loc, Luu Cam

    2017-09-01

    The effect of both total pressure and hydrogen partial pressure during n-hexane hydro-isomerization over platinum impregnated on HZSM-5 was studied. n-Hexane hydro-isomerization was conducted at atmospheric pressure and 0.7 MPa to observe the influence of total pressure. In order to see the effect of hydrogen partial pressure, the reaction was taken place at different partial pressure of hydrogen varied from 307 hPa to 718 hPa by dilution with nitrogen to keep the total pressure at 0.1 MPa. Physico-chemical characteristics of catalyst were determined by the methods of nitrogen physi-sorption BET, SEM, XRD, TEM, NH3-TPD, TPR, and Hydrogen Pulse Chemi-sorption. Activity of catalyst in the hydro-isomerization of n-hexane was studied in a micro-flow reactor in the temperature range of 225-325 °C; the molar ratio H2/ hydrocarbon: 5.92, concentration of n-hexane: 9.2 mol.%, GHSV 2698 h-1. The obtained catalyst expressed high acid density, good reducing property, high metal dispersion, and good balance between metallic and acidic sites. It is excellent contact for n-hexane hydro-isomerization. At 250 °C, n-hexane conversion and selectivity were as high as 59-76 % and 85-99 %, respectively. It was found that catalytic activity was promoted either by total pressure or hydrogen partial pressure. At total pressure of 0.7 MPa while hydrogen partial pressure of 718 hPa, catalyst produced 63 RON liquid product containing friendly environmental iso-paraffins which is superior blending stock for green gasoline. Hydrogen did not only preserve catalyst actives by depressing hydrocracking and removing coke precursors but also facilitated hydride transfer step in the bi-functional bi-molecular mechanism.

  7. Muonated cyclohexadienyl radicals observed by level crossing resonance in dilute solutions of benzene in hexane subjected to muon-irradiation

    International Nuclear Information System (INIS)

    Walker, D.C.; Barnabas, M.V.; Venkateswaran, K.

    1988-11-01

    Benzene is used here as a scavenger of muonium to produce the muonated cyclohexadienyl radical in dilute solutions in n-hexane. The radical was identified by level crossing resonance spectroscopy (LCR) by observing the proton resonance of the -CHMu group occurring at 2.059T. Its yield is found to equal the sum of the muonium atom yield and the 'missing' muon yield in hexane (total 35% of the incident muons). Consequently, the complete dispersement of muons in different chemical associations is now accounted for in a saturated hydrocarbon liquid, and is seen to be similar to that in water

  8. n-HEXANE NEUROPATHY DUE TO SHOEMAKING: REPORT OF FIVE CASES

    Directory of Open Access Journals (Sweden)

    K. Sadeghniat

    2005-04-01

    Full Text Available n-hexane neuropathy has been described after glue sniffing and industrial exposure. Onset may be subacute and reminiscent of Guillain-Barre' syndrome. Five patients (15-18 years old presented with paresthesia, severe weakness of the extremities particularly lower extremities, as well as muscular atrophy, total areflexia and gait disturbances were admitted in hospital in March 2003. All of these boys were workers of a small footwear production unit. They worked as gluers of leather pieces. Nerve conduction velocity studies showed latency prolongation and cerebrospinal fluid (CSF analysis showed normal protein. In the workplace assessment, it was found that hexacarbone-containing adhesives were used in an inappropriate ventilated place and without any personal protective devices. These patients were re-examined 8 months later. Sensory and autonomic symptoms were alleviated but two of them still had gait disturbance and decreased reflexes.

  9. Hexane neem leaf extract more potent than ethanol extract against Aspergillus flavus

    Directory of Open Access Journals (Sweden)

    Jenny Hidayat

    2015-12-01

    Full Text Available BACKGROUND Aspergillus flavus is one of the causes of aspergillosis, with a high virulence and resistance to standard antifungals, resulting in a high mortality rate. Medicinal plants are increasingly used as they are relatively safer with minimal side effects. Previously we found that the ethanol extract of neem (Azadirachta indica A Juss leaves inhibits A. flavus growth in vitro. However, most chemical compounds with antifungal effect are nonpolar. The purpose of this research was to compare the antifungal effect of neem leaves extracted in a nonpolar solvent to that of leaves extracted in a polar solvent. METHODS An in vitro experimental research was conducted between October 2013 and January 2014. Neem leaves were extracted in ethanol or hexane at various concentrations. A macrodilution test with 48-hour incubation time was done in triplicate on 8 groups of samples. These comprised the neem leaf ethanol extract (NLEE at 0.5, 1.0, and 2.0 g/dL, neem leaf hexane extract (NLHE at 0.5, 1.0, and 2.0 g/dL, positive control, and negative control groups. Fungal growth was detected on Sabouroud dextrose agar. Statistical analysis used Chi square and Fisher’s exact test. RESULTS NLHE had a higher, but statistically non-significant, inhibitory effect on A. flavus than NLEE (p=0.996. At higher concentrations, the antifungal effect of NLHE is better than that of NLEE. CONCLUSION There is no significant difference in in-vitro inhibitory effectivity on A. flavus of neem leaves between extracts in polar and nonpolar solvents.

  10. The hexane fraction of Ardisia crispa Thunb. A. DC. roots inhibits inflammation-induced angiogenesis

    Science.gov (United States)

    2013-01-01

    Background Ardisia crispa (Myrsinaceae) is used in traditional Malay medicine to treat various ailments associated with inflammation, including rheumatism. The plant’s hexane fraction was previously shown to inhibit several diseases associated with inflammation. As there is a strong correlation between inflammation and angiogenesis, we conducted the present study to investigate the anti-angiogenic effects of the plant’s roots in animal models of inflammation-induced angiogenesis. Methods We first performed phytochemical screening and high-performance liquid chromatography (HPLC) fingerprinting of the hexane fraction of Ardisia crispa roots ethanolic extract (ACRH) and its quinone-rich fraction (QRF). The anti-inflammatory properties of ACRH and QRF were tested using the Miles vascular permeability assay and the murine air pouch granuloma model following oral administration at various doses. Results Preliminary phytochemical screening of ACRH revealed the presence of flavonoids, triterpenes, and tannins. The QRF was separated from ACRH (38.38% w/w) by column chromatography, and was isolated to yield a benzoquinonoid compound. The ACRH and QRF were quantified by HPLC. The LD50 value of ACRH was 617.02 mg/kg. In the Miles vascular permeability assay, the lowest dose of ACRH (10 mg/kg) and all doses of QRF significantly reduced vascular endothelial growth factor (VEGF)-induced hyperpermeability, when compared with the vehicle control. In the murine air pouch granuloma model, ACRH and QRF both displayed significant and dose-dependent anti-inflammatory effects, without granuloma weight. ACRH and QRF significantly reduced the vascular index, but not granuloma tissue weight. Conclusions In conclusion, both ACRH and QRF showed potential anti-inflammatory properties in a model of inflammation-induced angiogenesis model, demonstrating their potential anti-angiogenic properties. PMID:23298265

  11. Hydrogen bonds and van der Waals forces as tools for the construction of a herringbone pattern in the crystal structure of hexane-1,6-diaminium hexane-1,6-diyl bis(hydrogen phosphonate

    Directory of Open Access Journals (Sweden)

    Guido J. Reiss

    2017-01-01

    Full Text Available The asymmetric unit of the title salt, [H3N(CH26NH3][(HOO2P(CH26PO2(OH], consists of one half of a hexane-1,6-diaminium dication and one half of a hexane-1,6-diyl bis(hydrogen phosphonate dianion. Both are located around different centres of inversion (Wyckoff sites: 2a and 2d of the space group P21/c. The shape of the hexane-1,6-diaminium cation is best described as a double hook. Both aminium groups as well as the two attached CH2 groups are turned out from the plane of the central four C atoms. In contrast, all six C atoms of the dianion are almost in a plane. The hydrogen phosphonate (–PO3H groups of the anions and the aminium groups of the cations form two-dimensional O—H... and O—H...N hydrogen-bonded networks parallel to the ac plane, built up from ten-membered and twelve-membered ring motifs with graph-set descriptors R33(10 and R54(12, respectively. These networks are linked by the alkylene chains of the anions and cations. The resulting three-dimensional network shows a herringbone pattern, which resembles the parent structures 1,6-diaminohexane and hexane-1,6-diphosphonic acid.

  12. Comparison of Hexane Vapour Permeation in Two Different Polymeric Membranes via an Innovative In-line FID Detection Method

    Directory of Open Access Journals (Sweden)

    Z. Petrusová

    2017-07-01

    Full Text Available This manuscript presents a novel method for the analysis of vapour permeation through polymeric membranes based on in-line analysis of the permeate with an FID detector. The hexane vapour permeation was studied for two commercially available membranes, namely low-density polyethylene (LDPE and thin-film-composite polyamide (PA membrane. The hexane permeation was studied at temperatures of 25–45 °C, hexane vapour activity in the range of 0.2–0.8 and trans-membrane pressures of 5–50 kPa. Two fundamentally different membranes were chosen to demonstrate the potential and sensitivity of the permeation apparatus. Upon increasing the temperature from 25 to 45 °C, the flux in LDPE was found to increase almost fourfold over the whole activity range. The nonlinear increase of the flux with activity indicates plasticization of the polymer by hexane. Contrarily, the flux in the PA membrane increases almost linearly with activity, with only a minor upward curvature. Since the PA is far away from any phase transition, it is less temperature-dependent than LDPE. The activation energy for permeation demonstrates that the temperature dependence in the LDPE membrane is dominated by changes in diffusion, whereas it is dominated by changes in solubility in the PA membrane.

  13. A LONG CHAIN ALCOHOL AND TWO STEROL COMPOUNDS FROM THE HEXANE EXTRACT OF STEM BARK OF Aglaia odorata Lour. (Meliaceae

    Directory of Open Access Journals (Sweden)

    Tukiran Tukiran

    2010-06-01

    Full Text Available A long chain alcohol, 1-eicosanol together with two sterols, β-sitosterol and stigmasterol had been isolated from hexane extract of stem bark of pacar cina (Aglaia odorata Lour (Meliaceae. These structures had been established based on spectroscopic data (IR and NMR and by comparison to those of standard compounds.   Keywords: Aglaia odorata Lour, Alcohol, Meliaceae, Sterol

  14. Hexane cracking over steamed phosphated zeolite H-ZSM-5 : Promotional effect on catalyst performance and stability

    NARCIS (Netherlands)

    Van Der Bij, Hendrik E.; Meirer, Florian; Kalirai, Samanbir; Wang, Jian; Weckhuysen, Bert M.

    2014-01-01

    The nature behind the promotional effect of phosphorus on the catalytic performance and hydrothermal stability of zeolite H-ZSM-5 has been studied using a combination of 27Al and 31P MAS NMR spectroscopy, soft X-ray absorption tomography and n-hexane catalytic cracking, complemented with NH3

  15. Chemical Composition of Hexane Extract of Different Parts of Anthemis talyschensis and its Potential to Use in Sunscreen Products

    Directory of Open Access Journals (Sweden)

    Alireza Motavalizadehkakhky

    2016-06-01

    Full Text Available In this study, both the presence and concentration of some unsaturated compounds in hexane extracts of different parts of Anthemis talyschensis showing absorption at wavelength 280-450 nm were surveyed, with the view of possibly using extracts of this plant in new formulations of sunscreen creams. The hexane extracts of flower, leaf and stem of A. talyschensis, collected from Northwest Iran, were obtained using a Soxhlet apparatus. The fatty acids were derivatized to methyl esters and were determined by gas chromatography/flame ionization detector (GC/FID and gas chromatography/mass spectrometry (GC/MS systems. The chemical analysis resulted in identification of 14, 9 and 29 constituents, comprising about 99.5, 97.1 and 98.2% of the total constituents in hexane extracts of flower, leaf and stem, respectively. The main unsaturated constituents in the hexane extract of A. talyschensis flower were 9, 12-octadecadienoic acid, 9-octadecenoic acid and 6, 9, 12-octadecatrienoic acid; while the leaf's extract contained 9, 12-octadecadienoic acid and 9-octadecenoic acid; no unsaturated compounds were detected in the stem. The ratios of unsaturated fatty acid /saturated fatty acid were 13.6, 9.3 and 0 in extracts of the flower, leaf and stem, respectively, but the total amounts in the leaf were much greater. It can be concluded the leaf extract is more likely to be suitable for producing sunscreens creams than others.

  16. Probing the surface swelling in ultra-thin supported polystyrene films during case II diffusion of n-hexane

    NARCIS (Netherlands)

    Ogieglo, Wojciech; Wormeester, Herbert; Wessling, Matthias; Benes, Nieck Edwin

    2013-01-01

    In situ time-resolved spectroscopic ellipsometry is used to study the dynamics of n-hexane diffusion into, and the corresponding induced swelling of, ultra-thin polystyrene films. The experimental conditions are carefully selected to facilitate the observation of anomalous Case II diffusion in the

  17. Synergistic Effects of n-Hexane Fraction of Parkia biglobosa (Jacq. Bark Extract and Selected Antibiotics on Bacterial Isolates

    Directory of Open Access Journals (Sweden)

    Oluwatayo E. Abioye

    2017-02-01

    Full Text Available The incidence of resistance to commonly used antimicrobial agents by microbial pathogens demands increased effort in the development of effective ways of treating infections and diseases. The n-hexane fraction of lyophilized crude bark extract of Parkia biglobosa (Jacq. was prepared and, in combination with selected antibiotics, assayed for antimicrobial activity against some selected bacterial pathogens using time-kill assay. Protein leakage analysis of the combined agents was performed using Bradford protein quantification method. Determination of active compounds present in the n-hexane fraction was done using Fourier Transform Infrared Spectroscopy (FTIR. While time-kill assay detected 43.33% synergy; 56.67% indifference and no antagonism at 1/2 × minimum inhibitory concentration (MIC, 1 × MIC exhibited 55% synergy, 45% indifference and no antagonism. Protein leakages from the cells of selected bacteria ranged from 1.20 µg/mL to 256.93 µg/mL. The presence of a phenyl group, an aromatic ring and phenolic compounds in the n-hexane fraction was confirmed at 2162 cm−1–2020 cm−1, 1605 cm−1–1533 cm−1 and 1438 cm−1–1444 cm−1 spectra peaks, respectively. The observed antibiotic−n-hexane fraction synergistic interaction revealed the improved antibacterial activity of the selected antibiotics. Hence, exploration of a combination of antibiotics with plant secondary metabolites is hereby advocated in the global quest for means of combating infectious diseases caused by multidrug-resistant pathogens.

  18. The oxidation of 2,2,5-three methyl-6-spiro cyclo hexane di hydro pyranol-5(X CI)

    International Nuclear Information System (INIS)

    Nikitin, V.I.

    1961-01-01

    In this chapter of book author as a result of oxidation of 2,2,5-three methyl-6-spiro cyclo hexane di hydro pyranol-5 evolved acetone, cyclopentanone, formic acid, acetic acid, oxalic acid, α-oxi isobutyric acid and adipinic acids

  19. Synthesis of Conformationally North-Locked Pyrimidine Nucleosides Built on an Oxabicyclo[3.1.0]hexane Scaffold | Center for Cancer Research

    Science.gov (United States)

    Beginning with a known 3-oxabicyclo[3.1.0]-hexane scaffold, the relocation of the fused cyclopropane ring bond and the shifting of the oxygen atom to an alternative location engendered a new 2-oxabicyclo[3.1.0]hexane template that mimics more closely the tetrahydrofuran ring of conventional nucleosides. The synthesis of this new class of locked nucleosides involved a novel

  20. Infrared reflection absorption spectroscopy study of radiation-heterogeneous processes in the system of aluminum-hexane

    International Nuclear Information System (INIS)

    Gadzhieva, N.N.; Rimikhanova, A.N.; Garibov, A.A.

    2004-01-01

    Full text: Infrared reflection absorption spectroscopy (IRRAS) was applied to study the regularities of radiation conversion of hexane on the surface of aluminum. The research object was the thin polished aluminum plate by mark of AD-00 with reflection coefficient R=0.8†0.85 in infrared range λ=2.2†15 μ . As adsorbate unsaturated vapors of spectroscopy clear hexane were used. The absorption of hexane (C 2 H 14 ) was being studied manometric at pressures P=(0.1†1.0)·10 2 Pa , what corresponded to monolayer value of 1-10. The samples were irradiated with γ-quanta of 60 Co with D=1.03 Gy·s -1 doze rate. Infrared reflection spectrum when linear-polarized radiation fall on the sample under angle ψ=10 o was measured by spectrophotometer 'Specord 71 JR' in diapason of 4000-650cm -1 at the temperature by mean of special reflecting arrangements. Formation of molecular hydrogen (H 2 ) and other gaseous products of decomposition were controlled by chromotographical and infrared spectroscopical methods. The analysis of hexane infrared absorption spectra after radiation-stimulated adsorption on the surface of aluminum, points out the formation of H-bonded hydrocarbon complex ( ν∼2680cm -1 ) with much loosening of C-H bond (the molecular form of absorption) and the possibility of proceeding dissociative absorption with formation of metal-alkyls (ν∼2880, 2920, 2970 cm -1 ). Probability of the last mentioned process, which proceeds in the most defective centers, increases with increasing of γ-radiation doze. It was established that the radiation processes in hetero system Al-ads.C 6 H 14 accelerate the radiolysis of hexane. At all these the radiation decomposition of hexane in hetero system Al-ads.C 6 H 14 is accompanied by formation the surface hydrides (ν∼1700-2000 cm -1 ), acetylene (ν∼3200-3300 cm -1 ), ethylene (ν∼980 cm -1 ), and also gaseous products of molecular hydrogen decomposition (H 2 ) and hydrocarbons C 1 -C 5 (bands with maxima 770, 790

  1. The study of the radiation chemical transformation of the hexane on the surface of aluminium by IR-spectroscopy method

    International Nuclear Information System (INIS)

    Rimikhanova, A.N.

    2006-01-01

    Full text: In this work the experimental results of the radiation-chemical transformation of hexane on the aluminum surface obtained by IR spectroscopy method at room temperature have been presented. The metallic aluminum plates which was obtained by stage pressing granules by mark of AD-00 with the reflection coefficient R=0,85 in the middle infrared range of waves length λ=15 ± 2,2 mkm were used. As an adsorbate unsaturated vapors of hexane were used, the absorption of which was being carried out at the room temperature by the method. The radiation of system was carried out with γ-quanta of Co 60 with doze rate of 1,03 Gy/s - 1, and the absorbed doze in the system was (0,5-2)10 4 Gy. IR reflection spectra when beams fall on the sample under angle near the slipping were measured in diapason of 3600-650 cm - 1 by the spectrophotometer S pecord 71IR . The radiation chemical decomposition of hexane in heterosystem was being traced in stretching (3000-2700 cm - 1) and deformation (1500-1300 cm - 1) vibration diapasons of C-H bonds. The analysis of IR reflection spectra of Al-ads.hexane heterosystem showed that the main products of radiation chemical transformation are hydrocarbons C1-C5, olefins: propylene, butene-1, hexene-1, transhexene-3 and hydrocarbons more heavy than hexane. In frequency range of 1700-2000 cm - 1 the absorption bands of Al-H vibration which concern to aluminum hydrides are founded. By increasing of radiation dose the tendency of increasing of hydrogen accumulation as aluminum hydrides has been established

  2. Comparison of antibacterial activity of Talok (Muntingia calabura L) leaves ethanolic and n-hexane extracts on Propionibacterium acnes

    Science.gov (United States)

    Desrini, Sufi; Ghiffary, Hifzhan Maulana

    2018-04-01

    Muntingia calabura L., also known locally as Talok or Kersen, is a plant which has been widely used as traditional medicine in Indonesia. In this study, we evaluated the antibacterial activity of Muntingia calabura L. Leaves ethanolic and n-hexane extract extract on Propionibacterium acnes. Antibacterial activity was determined in the extracts using agar well diffusion method. The antibacterial activities of each extract (2 mg/mL, 8 mg/ml, 20 mg/mL 30 mg/mL, and 40 mg/mL) were tested against to Propionibacterium acnes. Zone of inhibition of ethanolic extract and n-hexane extract was measured, compared, and analyzed by using a statistical programme. The phytochemical analyses of the plants were carried out using thin chromatography layer (TLC). The average diameter zone of inhibition at the concentration of 2 mg/mL of the ethanolic extract is 9,97 mm while n-Hexane extract at the same concentration showed 0 mm. Statistical test used was non-parametric test using Kruskal Wallis test which was continued to the Mann-Whitney to see the magnitude of the difference between concentration among groups. Kruskal-Wallis test revealed a significant value 0,000. Based on the result of Post Hoc test using Mann - Whitney test, there is the statistically significant difference between each concentration of ethanolic extract and n-hexane as well as positive control group (p-value < 0,05). Both extracts have antibacterial activity on P.acne. However, ethanolic extract of Muntingia calabura L. is better in inhibiting Propionibacterium acnes growth than n-hexane extract.

  3. Studies on the extraction of wheat germ oil by commercial hexane

    Directory of Open Access Journals (Sweden)

    El Kinawy, Omayma S.

    2002-12-01

    Full Text Available Extraction of an edible oil from wheat germ, an important byproduct of wheat milling industry in Egypt, using commercial hexane was studied. The extraction was carried out in a single and in two successive stages using different solvent-to-solid ratios from 2 to 6 m3/ ton. The results showed that a good oil recovery (about 75% can be achieved using 4 m3 hexane for each ton germ extracted in a single stage. This amount of solvent can be reduced to 2.5 m3/ ton if the process is carried out in two successive stages. The study has shown also that the amount of oil recovered from wheat germ is not significantly affected by heating the extraction mixture during the extraction process. The developments of free acids and peroxides in the oil during the storage period of wheat germ prior to extraction and during the hot extraction process were also investigated.Se ha estudiado la extracción de un aceite comestible a partir del germen de trigo, importante subproducto de la industria de la molienda del trigo en Egipto, usando hexano comercial. La extracción se llevó a cabo en una etapa única y en dos sucesivas, usando diferentes relaciones solvente-sólido desde 2 a 6 m3/ton. Los resultados mostraron que una buena recuperación de aceite (alrededor del 75% puede alcanzarse usando 4 m3 de hexano por cada tonelada de germen extraído en una etapa única. Esta cantidad de solvente puede reducirse a 2’5 m3/ton si el proceso se lleva a cabo en dos etapas sucesivas. El estudio mostró también que la cantidad de aceite recuperada a partir del germen de trigo no se afectó significativamente por el calentamiento de la mezcla durante el proceso de extracción. También se estudió la producción de ácidos libres y peróxidos en el aceite durante el período de almacenamiento del germen de trigo anterior a la extracción y durante el proceso de extracción en caliente

  4. Photolytic debromination pathway of polybrominated diphenyl ethers in hexane by sunlight

    International Nuclear Information System (INIS)

    Wei, Hua; Zou, Yonghong; Li, An; Christensen, Erik R.; Rockne, Karl J.

    2013-01-01

    The objective of this work is to identify the photolytic debromination pathways of polybrominated diphenyl ethers (PBDEs). Thirteen PBDEs (BDEs 209, 208, 207, 206, 196, 183, 154, 153, 100, 99, 85, 47 and 28) in hexane were individually exposed to sunlight for up to 64 h. A total of 180 PBDEs were screened and 74 BDE debromination products were detected. The disappearance rate constant increased exponentially with increasing number of bromines. While no evident difference in debromination preference among ortho, meta and para bromines was found for heavier congeners, the vulnerability rank order was meta ≥ ortho > para for the lighter congeners (≤8 Br). The total molar mass of PBDEs continuously decreased during sunlight exposure, indicating PBDEs were transformed to non-PBDE compounds. A stochastic least squares debromination pathway model was developed to simulate the reactions and determine the yields to extend the results beyond the experimental observations. -- Highlights: ► 74 PBDEs are identified as the products of debromination via photolysis. ► Debromination is more likely at meta than para positions for PBDEs with ≤8 bromines. ► The stochastic least squares model results agree with and expand the experimental observations. ► Mass imbalance indicates a significant loss of PBDE mass during sunlight exposure. -- The PBDE debromination products and pathways identified in this work will assist in future studies on their environmental fate

  5. Liposomal Formulation of Turmerone-Rich Hexane Fractions from Curcuma longa Enhances Their Antileishmanial Activity

    Directory of Open Access Journals (Sweden)

    Ana Claudia F. Amaral

    2014-01-01

    Full Text Available Promastigote forms of Leishmania amazonensis were treated with different concentrations of two fractions of Curcuma longa cortex rich in turmerones and their respective liposomal formulations in order to evaluate growth inhibition and the minimal inhibitory concentration (MIC. In addition, cellular alterations of treated promastigotes were investigated under transmission and scanning electron microscopies. LipoRHIC and LipoRHIWC presented lower MIC, 5.5 and 12.5 μg/mL, when compared to nonencapsulated fractions (125 and 250 μg/mL, respectively, and to ar-turmerone (50 μg/mL. Parasite growth inhibition was demonstrated to be dose-dependent. Important morphological changes as rounded body and presence of several roles on plasmatic membrane could be seen on L. amazonensis promastigotes after treatment with subinhibitory concentration (2.75 μg/mL of the most active LipoRHIC. In that sense, the hexane fraction from the turmeric cortex of Curcuma longa incorporated in liposomal formulation (LipoRHIC could represent good strategy for the development of new antileishmanial agent.

  6. Arrabidaea chica Hexanic Extract Induces Mitochondrion Damage and Peptidase Inhibition on Leishmania spp.

    Directory of Open Access Journals (Sweden)

    Igor A. Rodrigues

    2014-01-01

    Full Text Available Currently available leishmaniasis treatments are limited due to severe side effects. Arrabidaea chica is a medicinal plant used in Brazil against several diseases. In this study, we investigated the effects of 5 fractions obtained from the crude hexanic extract of A. chica against Leishmania amazonensis and L. infantum, as well as on the interaction of these parasites with host cells. Promastigotes were treated with several concentrations of the fractions obtained from A. chica for determination of their minimum inhibitory concentration (MIC. In addition, the effect of the most active fraction (B2 on parasite’s ultrastructure was analyzed by transmission electron microscopy. To evaluate the inhibitory activity of B2 fraction on Leishmania peptidases, parasites lysates were treated with the inhibitory and subinhibitory concentrations of the B2 fraction. The minimum inhibitory concentration of B2 fraction was 37.2 and 18.6 μg/mL for L. amazonensis and L. infantum, respectively. Important ultrastructural alterations as mitochondrial swelling with loss of matrix content and the presence of vesicles inside this organelle were observed in treated parasites. Moreover, B2 fraction was able to completely inhibit the peptidase activity of promastigotes at pH 5.5. The results presented here further support the use of A. chica as an interesting source of antileishmanial agents.

  7. Fractionation of benzene/n-hexane mixtures by pervaporation using polyurethane membranes

    Directory of Open Access Journals (Sweden)

    CUNHA V. S.

    1999-01-01

    Full Text Available In the present work polyurethane membranes obtained from different polyester/MDI-based polymers were used to separate benzene/n-hexane mixtures by pervaporation. In pervaporation experiments, with a 50% wt feed at room temperature, permeate fluxes in the range of 0.3 to 3.2 Kg/m2h (10 mm membrane thickness and selectivity in the range of 3.8 to 5.6 were obtained. The permeate was always enriched in benzene. Taking into account the compromise between flux and selectivity, the best performance membrane was selected for complementary sorption and pervaporation experiments. Results show that selectivity increases and the permeation flux decreases when the benzene concentration in the feed decreases. In the present application, results also show that sorption is the main factor for selectivity. Using the distillation azeotropic mixture as feed, almost no influence of temperature on selectivity was observed in the range of 25oC to 56oC. The permeate flux increases seven-fold, while selectivity remains constant near 8.0.

  8. Liposomal Formulation of Turmerone-Rich Hexane Fractions from Curcuma longa Enhances Their Antileishmanial Activity

    Science.gov (United States)

    Amaral, Ana Claudia F.; Gomes, Luciana A.; Silva, Jefferson Rocha de A.; Ferreira, José Luiz P.; Ramos, Aline de S.; Rosa, Maria do Socorro S.; Vermelho, Alane B.; Rodrigues, Igor A.

    2014-01-01

    Promastigote forms of Leishmania amazonensis were treated with different concentrations of two fractions of Curcuma longa cortex rich in turmerones and their respective liposomal formulations in order to evaluate growth inhibition and the minimal inhibitory concentration (MIC). In addition, cellular alterations of treated promastigotes were investigated under transmission and scanning electron microscopies. LipoRHIC and LipoRHIWC presented lower MIC, 5.5 and 12.5 μg/mL, when compared to nonencapsulated fractions (125 and 250 μg/mL), respectively, and to ar-turmerone (50 μg/mL). Parasite growth inhibition was demonstrated to be dose-dependent. Important morphological changes as rounded body and presence of several roles on plasmatic membrane could be seen on L. amazonensis promastigotes after treatment with subinhibitory concentration (2.75 μg/mL) of the most active LipoRHIC. In that sense, the hexane fraction from the turmeric cortex of Curcuma longa incorporated in liposomal formulation (LipoRHIC) could represent good strategy for the development of new antileishmanial agent. PMID:25045693

  9. Synthesis of nanostructured catalysts based on Mn oxide for n-hexane elimination

    International Nuclear Information System (INIS)

    Picasso, Gino; Salazar, Ivonne; Lopez, Alcides

    2011-01-01

    Nanostructured Mn oxide based catalysts were synthesized by sol-gel method and corresponding bulk samples were prepared by precipitation procedure. In addition, some nanostructured samples based on Mn oxide supported on bentonite (montmorillonite) were prepared by incipient impregnation. Prior to calcination, the system was submitted by TEM analysis in order to study the peptization effect of acetic acid. The micrographs revealed that the sample prepared from nitrate precursor (0,06 M) achieved the highest monodispersion. After calcination of nanoparticles, TEM analysis has been performed in order to evaluate how extent the peptization agent is able to disperse. TEM micrographs of samples prepared from nitrate precursor revealed that the peptization effect increased with the concentration of acetic acid. XRD difractograms of Mn oxide samples showed characteristic well-defined diffraction peaks associated to Mn species as Mn 2 O 3 , Mn 3 O 4 and MnO 2 with more relative intensive signals in Mn 2 O 3 and Mn 3 O 4 spinel. Finally, synthesized manganese oxide nanoparticles were incorpored into layered structure of purified bentonite (montmorillonite) by incipient impregnation. Some essays with the unsupported and supported samples were performed for n-hexane combustion in a fixed bed reactor. Activity of bentonite supported sample was lower than its unsupported bulk sample counterpart; however the performance was higher than the corresponding to the support without active component probably due to more suitable structure position of nanoparticles into layered framework of starting bentonite. (author).

  10. Spondias purpurea L. (Anacardiaceae: Antioxidant and Antiulcer Activities of the Leaf Hexane Extract

    Directory of Open Access Journals (Sweden)

    Cynthia Layse Ferreira de Almeida

    2017-01-01

    Full Text Available Spondias purpurea is used in folk medicine to treat diarrhea and diuresis. The objective of this study was to evaluate the phytochemical profile and antioxidant and antiulcer activities of the hexane extract of the leaves of S. purpurea (SpHE. Phytochemical profile was evaluated via thin layer chromatography (TLC and HPLC. SpHE was screened for antioxidant activities using DPPH, ABTS, FRAP, and phosphomolybdenum assays. To determine its antiulcer properties, animals were pretreated with injured control, lansoprazole, ranitidine, carbenoxolone, or SpHE (12.5, 25, and 50 mg/kg and were screened; acute ulcers were induced by HCl/ethanol, absolute ethanol, and nonsteroidal anti-inflammatory drug (NSAID. TLC revealed the presence of flavonoids, whereas HPLC analysis showed the presence of caffeic acid and epigallocatechin. The phenolic compounds and in vitro assays showed antioxidant activity. After gastric ulcer induction by using HCl/ethanol, SpHE reduced the area of ulcerative lesions by 82, 91, and 88%, respectively. In ethanol, SpHE reduced the area of ulcerative lesions by 77, 93, and 92%, respectively. In the NSAID, the percentages of protection were 70, 76, and 78%, respectively. SpHE promoted the minimization of ulcers, increased the levels of reduced glutathione, and decreased tumor necrosis factor. S. purpurea has antioxidant and antiulcer properties.

  11. Preparation of catalysts based on Cu-Mn for combustion of n-hexane

    International Nuclear Information System (INIS)

    Picasso, Gino; Belleza, Freddy; Zavala, Cesar; Lopez, Alcides; Sun Kou, Rosario

    2014-01-01

    Catalysts based on Cu-Mn mixed oxides (with molar ratio Cu/Mn in the range of 0,33 to 3) have been prepared by sol-gel method of self-combustion for removal of n-hexane. Two combustion agents, citric acid and ethylenglycol, were applied to study their influence in the final catalyst. Additionally, simple oxides have been synthesized using the same procedure for comparison reasons. The catalysts were characterized by X-ray diffraction (XRD) and sorption of N_2 (BET method). All samples depicted surfaces, preferentially assigned to mesoporosity whose values ranged from 4 to 50 m"2/g. All XRD difractograms of mixed samples showed the presence of a good crystalinity indepently of composition, with the formation of spinel-hopcalite phase meanwhile Mn and Cu simple oxide showed peaks attributed to Mn_O_3, Mn_3O_4 and CuO, respectively. Curves of activity, measured as number of VOC molecules converted per hour and per gram of catalyst, considering the specific surface, showed that mixed oxides with more Mn content were the best, additionally, the sample prepared from citric acid was more active than the corresponding values to simple oxides, probably due to the better specific surface and the better spinel-hopcalite structure obtained. (author)

  12. Amarginal contribution of selected carotenoids to the supression of UV-irradiation-induced lecithin peroxidation in hexane solution

    Directory of Open Access Journals (Sweden)

    DRAGAN CVETKOVIC

    2007-03-01

    Full Text Available The aim of this work was to study the anticipated antioxidant role of four selected carotenoids in mixtures with lecithin lipoidal compounds in hexane solution, under continuous UV-irradiation in three different ranges (UV-A, UV-B and UV-C. Two carotenes (b-carotene and licopene and two xantophylls (lutein and neoxanthin were employed to control the lipid peroxidation process generated by UV-irradiation, by scavenging the involved free radicals. The results show that while carotenoids undergo a substantial, structural dependent destruction (bleaching, which is highly dependent on energy of the UV-photons, their contribution to the expected suppression of lecithin peroxidation is of marginal importance, not exceeding a maximum of 20%. The marginal antioxidant behaviour has been attributed to a highly unordered hexane solution, where the scavenging action of the carotenoids becomes less competitive.

  13. Quasielastic neutron scattering and molecular dynamics simulation studies of the melting transition in butane and hexane monolayers adsorbed on graphite

    DEFF Research Database (Denmark)

    Hervig, K.W.; Wu, Z.; Dai, P.

    1997-01-01

    Quasielastic neutron scattering experiments and molecular dynamics (MD) simulations have been used to investigate molecular diffusive motion near the melting transition of monolayers of flexible rod-shaped molecules. The experiments were conducted on butane and hexane monolayers adsorbed...... comparison with experiment, quasielastic spectra calculated from the MD simulations were analyzed using the same models and fitting algorithms as for the neutron spectra. This combination of techniques gives a microscopic picture of the melting process in these two monolayers which is consistent with earlier...... neutron diffraction experiments. Butane melts abruptly to a liquid phase where the molecules in the trans conformation translationally diffuse while rotating about their center of mass. In the case of the hexane monolayer, the MD simulations show that the appearance of quasielastic scattering below T...

  14. Effect of temperature and pressure on excess electron mobility in n-hexane, 2,2,4-trimethylpentane, and tetramethylsilane

    International Nuclear Information System (INIS)

    Munoz, R.C.; Holroyd, R.A.

    1986-01-01

    Measurements of excess electron mobility are reported for liquid n-hexane, 2,2,4-trimethylpentane, and tetramethylsilane for pressures from 1 to 2500 bar and for temperatures from 18 to 120 0 C. For tetramethylsilane, a liquid that exhibits a high electron mobility, the mobility at constant density is proportional to T/sup -0.9/ between 25 and 100 0 C. The results are compared with the Basak--Cohen deformation potential theory. For n-hexane, where the mobility is low, Arrhenius behavior is observed. The isochoric activation energy increases with density. The results in this case are consistent with both the two-state and hopping models. In 2,2,4-trimethylpentane the mobility increases with increasing pressure at room temperature and decreases at high temperature. At 2500 bar and at intermediate temperatures (70--80 0 C) the mobility is approximately constant

  15. Surface properties and catalytic performance of Pt/LaSrCoO4 catalysts in the oxidation of hexane

    Directory of Open Access Journals (Sweden)

    Hua Zhong

    2007-08-01

    Full Text Available Perovskite-type La2 –xSrxCoO4 mixed oxides have been prepared by calcination at various temperatures of precipitates obtained from aqueous solutions in the presence of citric or ethylenediamintetraacetic (EDTA acids, and have been studied by X-ray diffraction (XRD, surface area (BET measurements, temperature programmed desorption (TPD, temperature programmed reduction (TPR and X-ray photoelectron spectroscopy (XPS. These oxides are catalysts for hexane oxidation, with the greatest activity for LaSrCoO4 calcined at 750 C. This has extensive oxygen vacancies and large internal surface area. Pt-modified LaSrCoO4 catalysts are significantly more active than the Pt-free system. Both surface and bulk phases of the preovskitetype oxides contribute to hexane oxidation.

  16. PHYTOCHEMICAL ASSESSMENT ON N-HEXANE EXTRACT AND FRACTIONS OF Marsilea crenata Presl. LEAVES THROUGH GC-MS

    Directory of Open Access Journals (Sweden)

    Burhan Ma'arif

    2016-08-01

    Full Text Available Estrogen deficiency causes various health problems in postmenopausal women, including osteoporosis. Phytoestrogen emerged as a potential alternative of estrogen with minimum side effects. Green clover (Marsilea crenata Presl. is a typical plant in East Java which suspected contains estrogen-like substances. The aim of this research was to report the phytochemical properties of M. crenata using GC-MS as a preliminary study. M. crenata leaves were dried and extracted with n-hexane, then separated using vacuum column chromatography to get four fractions, after that the n-hexane extract and four fractions were identified with GC-MS. The results of GC-MS analysis showed some compounds contained in M. crenata leaves like monoterpenoid, diterpenoid, fatty acid compounds, and other unknown compounds. The results obtained in this research indicated a promising potential of M. crenata as medicinal plants, especially as antiosteoporotic agent.

  17. Urinary 2,5-hexanedione in workers exposed to n-hexane: influence of the sample treatment

    Directory of Open Access Journals (Sweden)

    Daniela Magalhães Nolasco

    2007-08-01

    Full Text Available The aim of the present study was to determine 2,5-hexanedione (2,5-HD, a metabolite of n-hexane, by gas chromatography/flame ionization detection in 31 workers exposed to n-hexane after two types of sample pretreatment, i.e., with (total 2,5-HD and without (free 2,5-HD acid hydrolysis. The mean urinary 2,5-HD was 0.52 mg/L (free and 2.88 mg/L (total, this difference being significant (Student t-test, p < 0.05. The differences in the results according to the sample treatment support the need to modify the current Brazilian legislation, which proposes the analysis of 2,5-HD without indicating whether it is the free or total metabolite.

  18. Analysis of petroleum contaminated soils by spectral modeling and pure response profile recovery of n-hexane

    International Nuclear Information System (INIS)

    Chakraborty, Somsubhra; Weindorf, David C.; Li, Bin; Ali, Md. Nasim; Majumdar, K.; Ray, D.P.

    2014-01-01

    This pilot study compared penalized spline regression (PSR) and random forest (RF) regression using visible and near-infrared diffuse reflectance spectroscopy (VisNIR DRS) derived spectra of 164 petroleum contaminated soils after two different spectral pretreatments [first derivative (FD) and standard normal variate (SNV) followed by detrending] for rapid quantification of soil petroleum contamination. Additionally, a new analytical approach was proposed for the recovery of the pure spectral and concentration profiles of n-hexane present in the unresolved mixture of petroleum contaminated soils using multivariate curve resolution alternating least squares (MCR-ALS). The PSR model using FD spectra (r 2  = 0.87, RMSE = 0.580 log 10  mg kg −1 , and residual prediction deviation = 2.78) outperformed all other models tested. Quantitative results obtained by MCR-ALS for n-hexane in presence of interferences (r 2  = 0.65 and RMSE 0.261 log 10  mg kg −1 ) were comparable to those obtained using FD (PSR) model. Furthermore, MCR ALS was able to recover pure spectra of n-hexane. - Highlights: • We predicted soil petroleum contamination with VisNIR DRS spectra. • We examined 2 spectral pretreatments and 2 multivariate models. • MCR-ALS was used for compositional and spectral resolution of n-hexane. • Penalized spline regression performed best for quantifying soil TPH. • MCR-ALS was promising for resolution of complex soil–petroleum mixture. - Use of VisNIR DRS for rapid quantification of soil TPH and resolution of complex soil petroleum mixtures

  19. Hepatoprotective effects of hexane root extract of Alchornea laxiflora in sodium arsenate toxicity in wistar albino rats

    OpenAIRE

    Esosa Samuel Uhunmwangho; Nurudeen Olajide Rasaq; Iyanuoluwa Olubukola Osikoya

    2018-01-01

    Background: Medicinal plants are have been used in the treatment of myriad disease conditions, Alchornea laxiflora is one of such medicinal plant. Aim: To investigate the hepatoprotective effect of hexane root extract of Alchornea laxiflora against sodium arsenate induced liver damage in wistar male rats. Setting and Design: Extraction and administration of bioactive extract. Materials and Methods: Extraction of air-dried ground root of Alchornea laxiflora was done by extracting 500 g with 50...

  20. Flourensia cernua: Hexane Extracts a Very Active Mycobactericidal Fraction from an Inactive Leaf Decoction against Pansensitive and Panresistant Mycobacterium tuberculosis

    Directory of Open Access Journals (Sweden)

    Gloria María Molina-Salinas

    2011-01-01

    Full Text Available The efficacy of decoction in extracting mycobactericidal compounds from Flourensia cernua (Hojasé leaves and fractionation with solvents having ascending polarity was compared with that of (i ethanol extraction by still maceration, extraction with a Soxhlet device, shake-assisted maceration, or ultrasound-assisted maceration, followed by fractionation with n-hexane, ethyl acetate, and n-butanol; (ii sequential extraction with n-hexane, ethyl acetate, and n-butanol, by still maceration, using a Soxhlet device, shake-assisted maceration, or ultrasound-assisted maceration. The in vitro mycobactericidal activity of each preparation was measured against drug-sensitive (SMtb and drug-resistant (RMtb Mycobacterium tuberculosis strains. The results of which were expressed as absolute mycobactericidal activity (AMA. These data were normalized to the ΣAMA of the decoction fraction set. Although decoction was inactive, the anti-RMtb normalized ΣAMA (NAMA of its fractions was comparable with the anti-RMtb NAMA of the still maceration extracts and significantly higher than the anti-SMtb and anti-RMtb NAMAs of every other ethanol extract and serial extract and fraction. Hexane extracted, from decoction, material having 55.17% and 92.62% of antituberculosis activity against SMtb and RMtb, respectively. Although the mycobactericidal activity of decoction is undetectable; its efficacy in extracting F. cernua active metabolites against M. tuberculosis is substantially greater than almost all pharmacognostic methods.

  1. Thermodynamic properties of donor-acceptor complexes of tertiary amine with aryl ketones in hexane medium

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, R. [Department of Physics, The New College, Chennai 600 014 (India); Jayakumar, S. [Department of Physics, R.K.M. Vivekananda College, Chennai 600 004 (India); Kannappan, V., E-mail: vkannappan@hotmail.com [Department of Chemistry, Presidency College, Chennai 600 005 (India)

    2012-05-20

    Highlights: Black-Right-Pointing-Pointer Ultrasonic scan is carried out on ternary systems of aromatic tertiary amine and three aryl ketones. Black-Right-Pointing-Pointer Formation of CT complexes is found between tertiary amine with aryl ketones. Black-Right-Pointing-Pointer Stability constant values are computed by ultrasonic and spectral methods are compared. Black-Right-Pointing-Pointer The trend in the 'K' suggests that substituents in ketones influence the stabilities of these complexes. Black-Right-Pointing-Pointer The thermodynamic parameters suggest CT interaction is exothermic and the complexes are thermodynamically stable. - The thermodynamic stability of complexes formed between N,N-dimethylaniline (DMANI) and three ketones, namely, acetophenone (ACP), 4-chloroactophenone (ClACP) and 4-methylacetophenone (MACP) in n-hexane is extensively investigated by spectral and ultrasonic methods. The ultrasound scan was carried out in the temperature range 208.15-313.15 K and at atmospheric pressure on solutions containing equimolar concentrations of components ranging from 0.025 to 0.2 M. The existence of solute-solute interactions has also been confirmed through electronic absorption spectra analyzed with Benesi-Hildebrand theory at 303.15 K. The stability constants of the donor-acceptor complexes determined both by spectroscopic and ultrasonic methods are comparable and follow similar trends. The trend in the formation constants is discussed with structures of the components. The thermodynamic behavior of the systems was explained through the computed values of the free energy ({Delta}G), enthalpy ({Delta}H) and entropy ({Delta}S) changes for complex formation are computed and discussed.

  2. Acute toxicity of toluene, hexane, xylene, and benzene to the rotifers Brachionus calyciflorus and Brachionus plicatilis

    Energy Technology Data Exchange (ETDEWEB)

    Ferrando, M.D.; Andreu-Moliner, E. (Univ. of Valencia (Spain))

    1992-08-01

    A large number of studies on the biological effects of oil pollution in the aquatic environment deal with the effects of whole crude or refined oils or their water-soluble fractions. However, low boiling, aromatic hydrocarbons, which are probably the most toxic constituents of oil, have until now not been examined in sufficient detail. Toluene, benzene and xylene, constitute a major component of various oils. They may be readily lost by weathering but are toxic in waters that are relatively stagnant and are chronically polluted. Korn et al. have stated that toluene is more toxic than many other hydrocarbons such as benzene, though the latter are more water-soluble. Report of the effects of exposure to organic solvents like hexane or toluene are still limited although organic solvents are a well-known group of neurointoxicants. Various benzene derivates continue to be used as chemical intermediates, solvents, pesticides, so on, in spite of incomplete knowledge of their chronic toxicity. The majority of toxicity studies about the effects of pollution on aquatic organisms under controlled conditions have used either fish or the cladoceran Daphnia magna and there are few studies reported using rotifers. The effects of herbicides on population variables of laboratory rotifer cultures have been investigated. Rotifers are one of the main sources of zooplankton production and they have an important ecological significance in the aquatic environment. The present work was designed to investigate the effect of short-term exposure to some petroleum derivates which might be expected to occur immediately under an oil-slick, on freshwater and brackish environment rotifers. 18 refs., 1 tab.

  3. Molecular mechanics and quantum mechanical modeling of hexane soot structure and interactions with pyrene

    Directory of Open Access Journals (Sweden)

    Kubicki JD

    2000-09-01

    Full Text Available Molecular simulations (energy minimizations and molecular dynamics of an n-hexane soot model developed by Smith and co-workers (M. S. Akhter, A. R. Chughtai and D. M. Smith, Appl. Spectrosc., 1985, 39, 143; ref. 1 were performed. The MM+ (N. L. Allinger, J. Am. Chem. Soc., 1977, 395, 157; ref. 2 and COMPASS (H. Sun, J. Phys. Chem., 1998, 102, 7338; ref. 3 force fields were tested for their ability to produce realistic soot nanoparticle structure. The interaction of pyrene with the model soot was simulated. Quantum mechanical calculations on smaller soot fragments were carried out. Starting from an initial 2D structure, energy minimizations are not able to produce the observed layering within soot with either force field. Results of molecular dynamics simulations indicate that the COMPASS force field does a reasonably accurate job of reproducing observations of soot structure. Increasing the system size from a 683 to a 2732 atom soot model does not have a significant effect on predicted structures. Neither does the addition of water molecules surrounding the soot model. Pyrene fits within the soot structure without disrupting the interlayer spacing. Polycyclic aromatic hydrocarbons (PAH, such as pyrene, may strongly partition into soot and have slow desorption kinetics because the PAH-soot bonding is similar to soot–soot interactions. Diffusion of PAH into soot micropores may allow the PAH to be irreversibly adsorbed and sequestered so that they partition slowly back into an aqueous phase causing dis-equilibrium between soil organic matter and porewater.

  4. Hexane extracts of Polygonum multiflorum improve tissue and functional outcome following focal cerebral ischemia in mice.

    Science.gov (United States)

    Lee, Soo Vin; Choi, Kyung Ha; Choi, Young Whan; Hong, Jin Woo; Baek, Jin Ung; Choi, Byung Tae; Shin, Hwa Kyoung

    2014-04-01

    Polygonum multiflorum is a traditional Korean medicine that has been utilized widely in East Asian countries as a longevity agent. Clinical studies have demonstrated that Polygonum multiflorum improves hypercholesterolemia, coronary heart disease, neurosis and other diseases commonly associated with aging. However, scientific evidence defining the protective effects and mechanisms of Polygonum multiflorum against ischemic stroke is incomplete. In the present study, we investigated the cerebrovascular protective effects of Polygonum multiflorum against ischemic brain injury using an in vivo photothrombotic mouse model. To examine the underlying mechanism of action, we utilized an in vitro human brain microvascular endothelial cell (HBMEC) culture system. Hexane extracts (HEPM), ethyl acetate extracts (EAEPM) and methanol extracts (MEPM) of Polygonum multiflorum (100 mg/kg) were administered intraperitoneally 30 min prior to ischemic insult. Focal cerebral ischemia was induced in C57BL/6J mice and endothelial nitric oxide synthase knockout (eNOS KO) mice by photothrombotic cortical occlusion. We evaluated the infarct volume, as well as neurological and motor function, 24 h after ischemic brain injury. Following ischemic insult, HEPM induced a significant reduction in infarct volume and subsequent neurological deficits, compared with EAEPM and MEPM. HEPM significantly decreased infarct size and improved neurological and motor function, which was not observed in eNOS KO mice, suggesting that this cerebroprotective effect is primarily an eNOS-dependent mechanism. In vitro, HEPM effectively promoted NO production, however these effects were inhibited by the NOS inhibitor, L-NAME and the PI3K/Akt inhibitor, LY-294002. Furthermore, HEPM treatment resulted in increased phosphorylation-dependent activation of Akt and eNOS in HBMEC, suggesting that HEPM increased NO production via phosphorylation-dependent activation of Akt and eNOS. In conclusion, HEPM prevents cerebral

  5. Chemical kinetic insights into the ignition dynamics of n-hexane

    KAUST Repository

    Tingas, Alexandros

    2017-10-13

    Normal alkanes constitute a significant fraction of transportation fuels, and are the primary drivers of ignition processes in gasoline and diesel fuels. Low temperature ignition of n-alkanes is driven by a complex sequence of oxidation reactions, for which detailed mechanisms are still being developed. The current study explores the dynamics of low-temperature ignition of n-hexane/air mixtures, and identifies chemical pathways that characterize the combustion process. Two chemical kinetic mechanisms were selected as a comparative study in order to better understand the role of specific reaction sequences in ignition dynamics: one mechanism including a new third sequential O2 addition reaction pathways (recently proposed by Wang et al. 2017), while the other without (Zhang et al. 2015). The analysis is conducted by applying tools generated from the computational singular perturbation (CSP) approach to two distinct ignition phenomena: constant volume and compression ignition. In both cases, the role of the third sequential O2 addition reactions proves to be significant, although it is found to be much more pronounced in the constant volume cases compared to the HCCI. In particular, in the constant volume ignition case, reactions present in the third sequential O2 addition reaction pathways (e.g., KDHP  →  products + OH) contribute significantly to the explosivity of the mixture; when accounted for along with reactions P(OOH)2 + O2  →  OOP(OOH)2 and OOP(OOH)2  →  KDHP + OH, they decrease ignition delay time of the mixture by up to 40%. Under HCCI conditions, in the first-stage ignition, the third-O2 addition reactions contribute to the process, although their role decays with time and becomes negligible at the end of the first stage. The second ignition stage is dominated almost exclusively by hydrogen-related chemistry.

  6. Nanosized catalysts based on Fe oxide for combustion of n-hexane

    International Nuclear Information System (INIS)

    Picasso, Gino; Hermoza, Emilia; Lopez, Alcides; Gomez, Gemma; Pina, Maria Pilar; Herguido, Javier

    2009-01-01

    In this work, nanosized catalysts on Fe oxide have been prepared for total combustion on n-hexane (2000 ppmV). The synthesis of Fe oxide have been performed following sol-gel procedure starting from precursors based on nitrate salts. According to XRD analysis, nanoparticles formed α-hematite and the average particle size estimated by TEM was 9 nm with formation of agglomerations of 140 nm. Moreover, different clays pillared with Al (Al-PILC), Ti (Ti-PILC) and Fe (Fe-PILC) have been synthesized. Some samples based on Fe-Mn equimolar mixed supported on Al-PILC (FeMn/Al-PILC) and on Ti-PILC (FeMn/Ti-PILC) have been prepared in order to study the cooperative effect of Mn. Experimental conditions of calcination were adjusted in order to obtain samples with high thermal stability. XRD analysis of pillared samples revealed the formation of stable pillars, except for Fe-PILC which described a delaminated structure. As a consequence of pillaring, an enhancement of total surface area compared to starting clay material is observed. Concerning surface area, the decreasing order series of pillared material was: Ti-PILC > Fe-PILC > Al-PILC. Depression of total surface area decreasing of basal spacing d 001 with no modification of basal structure of starting natural clay have been observed due to the incorporation of Fe-Mn active phase into the structures of Ti-PILC and Al-PILC. The Fe-Mn mixed phase supported over pillared material exhibited higher catalytic activity than the Fe-PILC sample, which was attributed to the cooperative effect of Mn. This effect could be associated with redox properties of Mn and improving of surface oxygen mobility. Delaminated structure and strong interaction of Fe with clay porous network into the Fe-PILC sample could be the reason of lower activities. However, higher performances were observed in the case of Fe oxide nanoparticles prepared with surfactant agent over bentonite, due to a lesser extent of Fe-porous structure interaction presented in

  7. Phase-Transfer Energetics of Small-Molecule Alcohols Across the Water-Hexane Interface: Molecular Dynamics Simulation Using Charge Equilibration Models

    Science.gov (United States)

    Bauer, Brad A.; Zhong, Yang; Meninger, David J.; Davis, Joseph E.; Patel, Sandeep

    2010-01-01

    We study the water-hexane interface using molecular dynamics (MD) and polarizable charge equilibration (CHEQ) force fields. Bulk densities for TIP4P-FQ water and hexane, 1.0086±0.0002 g/cm3 and 0.6378±0.0001 g/cm3, demonstrate excellent agreement with experiment. Interfacial width and interfacial tension are consistent with previously reported values. The in-plane component of the dielectric permittivity (ε∥) for water is shown to decrease from 81.7±0.04 to unity, transitioning longitudinally from bulk water to bulk hexane. ε∥ for hexane reaches a maximum in the interface, but this term represents only a small contribution to the total dielectric constant (as expected for a non-polar species). Structurally, net orientations of the molecules arise in the interfacial region such that hexane lies slightly parallel to the interface and water reorients to maximize hydrogen bonding. Interfacial potentials due to contributions of the water and hexane are calculated to be -567.9±0.13mV and 198.7±0.01mV, respectively, giving rise to a total potential in agreement with the range of values reported from previous simulations of similar systems. Potentials of mean force (PMF) calculated for methanol, ethanol, and 1-propanol for the transfer from water to hexane indicate an interfacial free energy minimum, corresponding to the amphiphilic nature of the molecules. The magnitudes of transfer free energies were further characterized from the solvation free energies of alcohols in water and hexane using thermodynamic integration. This analysis shows that solvation free energies for alcohols in hexane are 0.2-0.3 kcal/mol too unfavorable, whereas solvation of alcohols in water is approximately 1 kcal/mol too favorable. For the pure hexane-water interfacial simulations, we observe a monotonic decrease of the water dipole moment to near-vacuum values. This suggests that the electrostatic component of the desolvation free energy is not as severe for polarizable models than

  8. Hepatoprotective effects of hexane root extract of Alchornea laxiflora in sodium arsenate toxicity in wistar albino rats

    Directory of Open Access Journals (Sweden)

    Esosa Samuel Uhunmwangho

    2018-01-01

    Full Text Available Background: Medicinal plants are have been used in the treatment of myriad disease conditions, Alchornea laxiflora is one of such medicinal plant. Aim: To investigate the hepatoprotective effect of hexane root extract of Alchornea laxiflora against sodium arsenate induced liver damage in wistar male rats. Setting and Design: Extraction and administration of bioactive extract. Materials and Methods: Extraction of air-dried ground root of Alchornea laxiflora was done by extracting 500 g with 500 cm of 95% hexane for 72 hrs.The animals (120-150 g were pre-treated with the extract at varying doses (0.1, 0.5, 1.0, 10, 50 and 100 mg/kg body weight for seven days orally prior to the intra-peritoneal administration of the toxicant (sodium arsenate at a dose of 2 mg/kg body weight at the eight day. Hepatoprotective activity of the extracts was evaluated by studying the Cytochrome b5content, Glutathione-S-transferase and 4- Nitroanisole-o-demethylase activities in the liver, Plasma levels of Alanine aminotransferase (AST, Alanine aminotransferase (ALT, Alkaline phosphatase (ALP and the levels of Total protein, Albumin, Globulin and Glutathione of the various groups. Statistical Analysis: The data were analysed with Microsoft excels (for windows 2007 and Student t-test and ANOVA. Result and Conclusion: The results suggest that pre-treatment of rats with hexane root extract of Alchornea laxiflora for seven days reduced the elevated levels of liver enzymes, reduced the levels of induced liver metabolizing enzymes and the levels of Total protein, Albumin, Globulin and Glutathione that was increased by the toxicity of sodium arsenate in rats and as such possess hepatoprotective effect against sodium arsenate.

  9. Chemical composition of the essential oil and hexane extract of Salvia chionantha and their antioxidant and anticholinesterase activities.

    Science.gov (United States)

    Tel, Gülsen; Oztürk, Mehmet; Duru, Mehmet Emin; Harmandar, Mansur; Topçu, Gülaçti

    2010-11-01

    The essential oil and methyl ester of hexane extract of Salvia chionantha Boiss. were analysed by GC and GC-MS. Totally, 54 components were detected in the essential oil and all of them were fully determined. Germacrene D (25.03%), β-caryophyllene (8.71%), spathulenol (5.86%) and α-humulene (4.82%) were identified as the major compounds. In the methylated hexane extract, 3-hydroxy hexadecanoic acid (39.39%), 3-hydroxy tetradecanoic acid (12.66%) and palmitic acid (12.02%) were the major fatty acids elucidated. The antioxidant activity of the essential oil and the hexane extract was determined by using four complementary test systems; namely, β-carotene-linoleic acid, DPPH() scavenging, ABTS(+)* scavenging, and CUPRAC assays. In β-carotene-linoleic acid assay, the extract showed 81.2±0.1% lipid peroxidation inhibition at 0.8 mg/mL concentration, while in ABTS(+)* assay the essential oil exhibited 77.4±0.5% inhibition at same concentration. Since, acetylcholinesterase and butyrylcholinesterase enzymes are taking place in pathogenesis of Alzheimer's disease, in vitro anticholinesterase activity of the essential oil and the extract was also studied spectrophotometrically. At 0.5mg/mL concentration, the essential oil showed moderate acetylcholinesterase (56.7±1.9%) and butyrylcholinesterase (41.7±2.9%) inhibitory activity, while the extract was only exhibited activity (63.1±0.8%) against butyrylcholinesterase enzyme. Hence, the essential oil may be useful as a moderate anticholinesterase agent, particularly against acetylcholinesterase. Copyright © 2010 Elsevier Ltd. All rights reserved.

  10. New Methyltrimethoxysilane-(3-Mercaptopropyl)- Trimethoxysilane Coated Hollow Fiber-Solid Phase Micro extraction for Hexanal and Heptanal Analysis

    International Nuclear Information System (INIS)

    Siti Munirah Abd Wahib; Mohd Marsin Sanagi

    2016-01-01

    Determination of volatile organic compounds (VOCs) in various matrices is often accomplished using solid phase micro extraction (SPME) as a superior mode of extraction. Alternatively, another configuration of solid phase micro extraction (SPME) namely hollow fiber-solid phase micro extraction (HF-SPME) is a great approach to redress some limitations of the ordinary SPME fibers including fiber breakage, coating stripping and sample carry over. The HF-SPME technique highlights the use of hollow polypropylene (PP) membrane to hold and protect the adsorbent inside its lumen. Unlike the conventional SPME, the inexpensive HF device can be disposed after single use. Introducing extracting phase via sol-gel technology has gained great interest owing to its simple preparation method and promising way to obtain materials with good characteristics. In the present work, a new hybrid silica material based on methyltrimethoxysilane-(3-mercaptopropyl)trimethoxysilane (MTMOS-MPTMOS) was introduced as a new extractant of HF-SPME and the effectiveness of the proposed method was tested for analysis of hexanal and heptanal as the target VOC analytes. Preparation of the HF-SPME MTMOS-MPTMOS was simple in which the hybrid material was synthesized via sol-gel method and was self-polymerized in small segments of HF. Parameters affecting the efficiency of the HF-SPME MTMOS-MPTMOS in extracting both aldehydes were thoroughly investigated and analyzed by gas chromatography-flame ionization detection (GC-FID). It was found that the highest efficiency was achieved as the extraction was conducted in 30 min at a stirring rate of 1000 rpm in a 10 mL of sample solution whereby the back-extraction was performed via vortex for 3 min using 100 μL methanol as desorption solvent. Under the optimal conditions, linearity was observed over a range of 0.020-10.00 μg mL"-"1 with detection limits of 0.015 μg mL"-"1 and 0.010 μg mL"-"1 for hexanal and heptanal, respectively. The applicability of the HF

  11. Spectacular Rate Enhancement of the Diels-Alder Reaction at the Ionic Liquid/n-Hexane Interface.

    Science.gov (United States)

    Beniwal, Vijay; Manna, Arpan; Kumar, Anil

    2016-07-04

    The use of the ionic liquid/n-hexane interface as a new class of reaction medium for the Diels-Alder reaction gives large rate enhancements of the order of 10(6) to 10(8) times and high stereoselectivity, as compared to homogeneous media. The rate enhancement is attributed to the H-bonding abilities and polarities of the ionic liquids, whereas the hydrophobicity of ionic liquids was considered to be the factor in controlling stereoselectivity. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Effect of Enhanced Accessibility of Acid Sites in Micromesoporous Mordenite Zeolites on Hydroisomerization of n-Hexane

    Czech Academy of Sciences Publication Activity Database

    Pastvová, Jana; Kaucký, Dalibor; Morávková, Jaroslava; Rathouský, Jiří; Sklenák, Štěpán; Vorokhta, Maryna; Brabec, Libor; Pilař, Radim; Jakubec, Ivo; Tabor, Edyta; Klein, Petr; Sazama, Petr

    2017-01-01

    Roč. 7, č. 9 (2017), s. 5781-5795 ISSN 2155-5435 R&D Projects: GA ČR GA15-12113S; GA MŠk(CZ) LM2015073 Institutional support: RVO:61388955 ; RVO:61388980 ; RVO:67985891 Keywords : micromesoporous mordenite (MOR) zeolites * isomerization * n-hexane Subject RIV: CF - Physical ; Theoretical Chemistry; CA - Inorganic Chemistry (UACH-T); CA - Inorganic Chemistry (USMH-B) OBOR OECD: Physical chemistry; Inorganic and nuclear chemistry (UACH-T); Inorganic and nuclear chemistry (USMH-B) Impact factor: 10.614, year: 2016

  13. Synthesis of zeolite-zeolite (mfi-fau) composite catalysts for the isomerization of n-hexane

    International Nuclear Information System (INIS)

    Ghouri, A.S; Usman, M.R.

    2017-01-01

    In this research work, the aim is to produce a relatively novel zeolite-zeolite (MFI-FAU) composite catalyst having better potential of catalyzing isomerization of lighter hydrocarbons such as light naphtha, n-pentane, n-hexane, n-heptane and mixture thereof. A series of zeolite-zeolite (MFI-FAU) composite catalysts have been synthesized by incorporating previous practices and techniques. The catalytic performance of as-synthesized zeolite-zeolite (MFI-FAU) composite catalysts have been investigated by isomerizing 95% pure n-hexane in conventional fixed bed flow micro-reactor at temperature 200-240 ºC under atmospheric pressure. In order to explore chemical and physical features of zeolite-zeolite (MFI-FAU) composite catalysts, they are examined and characterized using powder X-ray diffraction (XRD), scanning electron microscopy (SEM) coupled with energy-dispersive X-ray spectrometry (EDX), N2 adsorption-desorption measurements (BET, BJH, t-plot measurements) and Fourier transform infrared (FTIR) spectroscopy equipped with attenuated total reflectance (ATR) arrangements. (author)

  14. Thermodiffusion, molecular diffusion and Soret coefficient of binary and ternary mixtures of n-hexane, n-dodecane and toluene.

    Science.gov (United States)

    Alonso de Mezquia, David; Wang, Zilin; Lapeira, Estela; Klein, Michael; Wiegand, Simone; Mounir Bou-Ali, M

    2014-11-01

    In this study, the thermodiffusion, molecular diffusion, and Soret coefficients of 12 binary mixtures composed of toluene, n-hexane and n-dodecane in the whole range of concentrations at atmospheric pressure and temperatures of 298.15 K and 308.15 K have been determined. The experimental measurements have been carried out using the Thermogravitational Column, the Sliding Symmetric Tubes and the Thermal Diffusion Forced Rayleigh Scattering techniques. The results obtained using the different techniques show a maximum deviation of 9% for the thermodiffusion coefficient, 8% for the molecular diffusion coefficient and 2% for the Soret coefficient. For the first time we report a decrease of the thermodiffusion coefficient with increasing ratio of the thermal expansion coefficient and viscosity for a binary mixture of an organic ring compound with a short n-alkane. This observation is discussed in terms of interactions between the different components. Additionally, the thermogravitational technique has been used to measure the thermodiffusion coefficients of four ternary mixtures consisting of toluene, n-hexane and n-dodecane at 298.15 K. In order to complete the study, the values obtained for the molecular diffusion coefficient in binary mixtures, and the thermodiffusion coefficient of binary and ternary mixtures have been compared with recently derived correlations.

  15. Experimental Determination of the Molar Absorption Coefficient of n-Hexane Adsorbed on High-Silica Zeolites.

    Science.gov (United States)

    Gatti, Giorgio; Olivas Olivera, Diana F; Sacchetto, Vittoria; Cossi, Maurizio; Braschi, Ilaria; Marchese, Leonardo; Bisio, Chiara

    2017-09-06

    Determination of the molar absorption coefficients of the CH 3 bending mode at ν˜ =1380 cm -1 (ϵ 1380 ) of n-hexane adsorbed from the gas phase on two different dealuminated zeolites is derived by a combination of IR spectroscopy and microgravimetric analysis. High-silica zeolite Y (HSZ-Y) and zeolite ZSM-5 (with SiO 2 /Al 2 O 3 ratios of 200 and 280, respectively) with different textural and surface features are selected to evaluate the effect of the pore structure and architecture on the value of ϵ 1380 of the adsorbed n-hexane. Experimental data indicate that the molecule experiences a different adsorption environment inside zeolites; thus resulting in a significant change of the dipole moment and very different ϵ 1380 values: (0.278±0.018) cm μmol -1 for HSZ-Y and (0.491±0.032) cm μmol -1 for ZSM-5. Experimental data are also supported by computational modeling, which confirms the effect of different matrices on the IR absorption intensity. This study reveals that the use of probe molecules for quantitative measurements of surface sites has to be judiciously adopted, especially if adsorption occurs in the restricted spaces of microporous materials. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Preparation of catalysts based on Ce-Mn mixed oxide by coprecipitation for combustion of n-hexane

    International Nuclear Information System (INIS)

    Picasso, Gino; Zavala, Cesar; Cruz, Romulo; Sun Kou, Rosario; Lopez, Alcides

    2013-01-01

    Catalysts based on Ce-Mn mixed with different Ce/Mn molar ratios ranging from 0,5 to 2 have been prepared by coprecipitation at pH constant with ageing times of 4, 18 and 24 h for combustion of n-hexane. XRD patterns of the mixed oxides showed the majority presence of fluorite phase. Specific BET surface areas of mixed oxides were always higher than their single counterparts and their adsorption isotherm depicted a mesoporous surface of Type IV. TPR thermograms confirmed the presence of mixed oxide phase, whose profile shifted to smaller temperatures with increasing content of ceria. Catalytic tests were performed with 2000 ppm of n-hexane and WHSV of 80 h -1 in a fixed-bed reactor. For all samples, only CO 2 and water were observed at total conversion and no partial combustion products were obtained. Ce-Mn mixed oxides were more active than simple oxide samples no matter the aging time. Mixed samples presented thermal stability in contrast with simple ones. Mixed sample with Ce/Mn molar ratio of 2 depicted the highest activity probably due to higher surface area and better reducibility ability of mixed phase. (author)

  17. Solid-phase microextraction method for the determination of hexanal in hazelnuts as an indicator of the interaction of active packaging materials with food aroma compounds.

    Science.gov (United States)

    Pastorelli, S; Valzacchi, S; Rodriguez, A; Simoneau, C

    2006-11-01

    Fatty foods are susceptible to lipid oxidation resulting in deterioration of product quality due to the generation of off-flavours. Hexanal is a good indicator of rancidity. Therefore, a method based on solid-phase microextraction (SPME) coupled to gas chromatograph with flame ionization detection was developed to determine hexanal formation in hazelnuts during storage. Optimum conditions were as follows: carboxen-polydimethylsiloxane 75 microm fibre, extraction time 10 min, equilibrium time 10 min and equilibrium temperature 60 degrees C. The effect of oxygen scavengers on the oxidation process was also evaluated by measuring hexanal formation in hazelnuts stored with/without oxygen absorber sachets. Oxygen scavengers were shown to reduce oxidation; however, analysis of the sachet revealed that other volatile compounds from the headspace were also absorbed.

  18. GC-MS characterization of n-hexane soluble fraction from dandelion (Taraxacum officinale Weber ex F.H. Wigg.) aerial parts and its antioxidant and antimicrobial properties.

    Science.gov (United States)

    Ivanov, Ivan; Petkova, Nadezhda; Tumbarski, Julian; Dincheva, Ivayla; Badjakov, Ilian; Denev, Panteley; Pavlov, Atanas

    2018-01-26

    A comparative investigation of n-hexane soluble compounds from aerial parts of dandelion (Taraxacum officinale Weber ex F.H. Wigg.) collected during different vegetative stages was carried out. The GC-MS analysis of the n-hexane (unpolar) fraction showed the presence of 30 biologically active compounds. Phytol [14.7% of total ion current (TIC)], lupeol (14.5% of TIC), taraxasteryl acetate (11.4% of TIC), β-sitosterol (10.3% of TIC), α-amyrin (9.0% of TIC), β-amyrin (8.3% of TIC), and cycloartenol acetate (5.8% of TIC) were identified as the major components in n-hexane fraction. The unpolar fraction exhibited promising antioxidant activity - 46.7 mmol Trolox equivalents/g extract (determined by 1,1-diphenyl-2-picrylhydrazyl method). This fraction demonstrated insignificant antimicrobial activity and can be used in cosmetic and pharmaceutical industries.

  19. Impact of structural modification of 1,2,4-thiadiazole derivatives on thermodynamics of solubility and solvation processes in 1-octanol and n-hexane

    International Nuclear Information System (INIS)

    Surov, Artem O.; Bui, Cong Trinh; Volkova, Tatyana V.; Proshin, Alexey N.; Perlovich, German L.

    2016-01-01

    Highlights: • Solubility processes of some 1,2,4-thiadiazoles in n-hexane and 1-octanol were investigated. • Solvation processes of some 1,2,4-thiadiazoles in n-hexane and 1-octanol were studied. • Transfer processes from n-hexane to 1-octanol were evaluated. • Impact of various substituents in 1,2,4-thiadiazoles on the mentioned processes was studied. - Abstract: Influence of a structural modification on thermodynamic aspects of solubility and solvation processes of the 1,2,4-thiadiazole drug-like compounds in pharmaceutically relevant solvents n-hexane and 1-octanol was investigated. The solubility of the compounds in 1-octanol does not substantially depend on the nature and position of the substituent in the phenyl moiety. In n-hexane, however, the introduction of any substituent in the phenyl ring of the 1,2,4-thiadiazole molecule reduces the solubility in the solvent. In order to rationalize the relationships between the structure of 1,2,4-thiadiazoles and their solubility, the latter was considered in terms of two fundamental processes: sublimation and solvation. It was found that for the most of the compounds the solubility change in both solvents is a consequence of competition between the sublimation and solvation contributions, i.e. the introduction of substituents leads to growth of the sublimation Gibbs energy and increase in the solvation Gibbs energy. Thermodynamic parameters of the transfer process of the compounds from n-hexane to 1-octanol, which is a model of the blood–brain barrier (BBB), were also analyzed.

  20. Mutual solubility between hexane and three-n-butyl phosphate solvates of lanthanide(III) and thorium(IV) nitrates at various temperatures

    International Nuclear Information System (INIS)

    Keskinov, V.A.; Lishuk, V.V.; Pyartman, A.K.

    2007-01-01

    Phase diagrams of binary liquid systems of hexane-rare earth(III) nitrates solvates (rare earth - neodymium, gadolinium, yttrium, ytterbium, lutetium) and thorium(IV) with tri-n-butylphosphate are studied at different temperatures. Phase diagrams of binary systems consist of fields of homogeneous solutions and field of stratification into two liquid phases (I, II): phase I is enriched by hexane, and phase II - [Ln(NO 3 ) 3 (TBP) 3 ] (Ln=Nd, Gd, Y, Yb and Lu) or [Th(NO 3 ) 4 (TBP) 2 ]. Field of stratification into two liquid phases are decreased with growing temperature in binary systems [ru

  1. Supercritical SC-CO2 and Soxhlet n-Hexane Extract of Tunisian Opuntia ficus indica Seeds and Fatty Acids Analysis

    OpenAIRE

    Nizar Yeddes; Jamila Kalthoum Chérif; Amel Jrad; Danielle Barth; Malika Trabelsi-Ayadi

    2012-01-01

    The fatty acids profiles of Tunisian Opuntia ficus indica seeds (spiny and thornless form) were investigated. Results of supercritical carbon dioxide (SC-CO2) and soxhlet n-hexane extract were compared. Quantitatively, the better yield was obtained through soxhlet n-hexane: 10.32% (spiny) and 8.91% (thornless) against 3.4% (spiny) and 1.94% (thornless) by SC-CO2 extract (T = 40°C, P=180 bar, time = 135 mn, CO2 flow rate = 15 mL·s−1). Qualitatively, the main fatty acids components were the sam...

  2. Thermodiffusion Coefficient Analysis of n-Dodecane /n-Hexane Mixture at Different Mass Fractions and Pressure Conditions

    Science.gov (United States)

    Lizarraga, Ion; Bou-Ali, M. Mounir; Santamaría, C.

    2018-03-01

    In this study, the thermodiffusion coefficient of n-dodecane/n-hexane binary mixture at 25 ∘C mean temperature was determined for several pressure conditions and mass fractions. The experimental technique used to determine the thermodiffusion coefficient was the thermograviational column of cylindrical configuration. In turn, thermophysical properties, such as density, thermal expansion, mass expansion and dynamic viscosity up to 10 MPa were also determined. The results obtained in this work showed a linear relation between the thermophysical properties and the pressure. Thermodiffusion coefficient values confirm a linear effect when the pressure increases. Additionally, a new correlation based on the thermodiffusion coefficient for n C12/n C6 binary mixture at 25 ∘C temperature for any mass fraction and pressures, which reproduces the data within the experimental error, was proposed.

  3. Theoretical and Spectroscopic investigations of conformations, rotational barriers and scaled vibrations of 2,3-dimethyl hexane

    Directory of Open Access Journals (Sweden)

    Aziz Aboulmouhajir

    2017-01-01

    Full Text Available The 2,3-dimethyl hexane conformational isomerism has been investigated in detail, based on HF, Post-HF and DFT calculations at different basis set. The effect of size of basis, ZPE, thermal contributions, electronic correlation and optimization methods on the conformational stability was discussed. The rotational barriers from the most stable conformer to the lowest energy secondary conformers and their correspondent inversion barriers at both HF and MP2 methods using 6-31G* basis set have also been approached. A normal mode calculation of the most and less-stable conformers using a scaled ab initio force field in terms of non-redundant local symmetry coordinates have been made to elucidate the conformational dependence of the vibrational spectra.

  4. Synthesis of highly reactive polyisobutylene with FeCl3/ether complexes in hexane; kinetic and mechanistic studies

    KAUST Repository

    Kumar, Rajeev Ananda; De, Priyadarsi; Zheng, Bin; Huang, Kuo-Wei; Emert, Jack I.; Faust, Rudolf

    2015-01-01

    The kinetics and mechanism of the polymerization of isobutylene catalyzed by FeCl3·ether complexes in hexane at 0°C were investigated. The polymerization rates increased in the diisopropyl ether< 2-chloroethyl ethyl ether < bis(2-chloroethyl) ether order, attributed to electronic effects. The polymerization rates increased with increasing initiator and catalyst concentrations. The first order plots, however, deviated from the linear suggesting that the cation concentration decreases with time. The previously proposed mechanism is inadequate to explain this finding. The decrease in the polymerization rate with time is explained by the low solubility of the H+ROR′FeCl4 - complexes that precipitate during polymerization. Based on mechanistic studies the revised mechanism now also includes the equilibrium H+ROR′FeCl4 - ⇋ HCl + FeCl3·ROR′.

  5. Esterification of fatty acids using nylon-immobilized lipase in n-hexane: kinetic parameters and chain-length effects.

    Science.gov (United States)

    Zaidi, A; Gainer, J L; Carta, G; Mrani, A; Kadiri, T; Belarbi, Y; Mir, A

    2002-02-28

    The esterification of long-chain fatty acids in n-hexane catalyzed by nylon-immobilized lipase from Candida rugosa has been investigated. Butyl oleate (22 carbon atoms), oleyl butyrate (22 carbon atoms) and oleyl oleate (36 carbon atoms) were produced at maximum reaction rates of approximately equal to 60 mmol h(-1) g(-1) immobilized enzyme when the substrates were present in equimolar proportions at an initial concentration of 0.6 mol l(-1). The observed kinetic behavior of all the esterification reactions is found to follow a ping-pong bi-bi mechanism with competitive inhibition by both substrates. The effect of the chain-length of the fatty acids and the alcohols could be correlated to some mechanistic models, in accordance with the calculated kinetic parameters.

  6. Synthesis of highly reactive polyisobutylene catalyzed by EtAlCl 2/Bis(2-chloroethyl) ether soluble complex in hexanes

    KAUST Repository

    Kumar, Rajeev Ananda; Zheng, Bin; Huang, Kuo-Wei; Emert, Jack I.; Faust, Rudolf

    2014-01-01

    The polymerization of isobutylene (IB) to yield highly reactive polyisobutylene (HR PIB) with high exo-olefin content using GaCl3 or FeCl3·diisopropyl ether complexes has been previously reported.1 In an effort to further improve polymerization rates and exo-olefin content, we have studied ethylaluminum dichloride (EADC) complexes with diisopropyl ether, 2-chloroethyl ethyl ether (CEEE), and bis(2-chloroethyl) ether (CEE) as catalysts in conjunction with tert-butyl chloride as initiator in hexanes at different temperatures. All three complexes were readily soluble in hexanes. Polymerization, however, was only observed with CEE. At 0 °C polymerization was complete in 5 min at [t-BuCl] = [EADC·CEE] = 10 mM and resulted in PIB with ∼70% exo-olefin content. Studies on complexation using ATR FTIR and 1H NMR spectroscopy revealed that at 1:1 stoichiometry a small amount of EADC remains uncomplexed. By employing an excess of CEE, exo-olefin contents increased up to 90%, while polymerization rates decreased only slightly. With decreasing temperature, polymerization rates decreased while molecular weights as well as exo-olefin contents increased, suggesting that isomerization has a higher activation energy than β-proton abstraction. Density functional theory (DFT) studies on the Lewis acid·ether binding energies indicated a trend consistent with the polymerization results. The polymerization mechanism proposed previously for Lewis acid·ether complexes1 adequately explains all the findings. © 2014 American Chemical Society.

  7. Applications of the hexanic fraction of Agave sisalana Perrine ex Engelm (Asparagaceae: control of inflammation and pain screening

    Directory of Open Access Journals (Sweden)

    Ricardo Jose Dunder

    2013-05-01

    Full Text Available The present study evaluated the anti-inflammatory and analgesic properties of Agave sisalana Perrine in classic models of inflammation and pain. The hexanic fraction of A. sisalana (HFAS was obtained by acid hydrolysis followed by hexanic reflux. Anti-inflammatory properties were examined in three acute mouse models (xylene ear oedema, hind paw oedema and pleurisy and a chronic mouse model (granuloma cotton pellet. The antinociceptive potential was evaluated in chemical (acetic-acid and thermal (tail-flick and hot-plate test models of pain. When given orally, HFAS (5, 10, 25 and 50 mg/kg reduced ear oedema (p < 0.0001; 52%, 71%, 62% and 42%, respectively. HFAS also reduced hind paw oedema at doses of 10 mg/kg and 25 mg/kg (p < 0.05; 42% and 58%, respectively and pleurisy at doses of 10 mg/kg and 25 mg/kg (41% and 50%, respectively. In a chronic model, HFAS reduced inflammation by 46% and 58% at doses of 10 mg/kg and 25 mg/kg, respectively. Moreover, this fraction showed analgesic properties against the abdominal writhing in an acetic acid model (at doses of 5-25 mg/kg with inhibitory rates of 24%, 54% and 48%. The HFAS also showed an increased latency time in the hot-plate (23% and 28% and tail-flick tests (61% and 66% for the 25 mg/kg and 50 mg/kg doses, respectively. These results suggest that HFAS has anti-inflammatory and analgesic properties.

  8. Synthesis of highly reactive polyisobutylene catalyzed by EtAlCl 2/Bis(2-chloroethyl) ether soluble complex in hexanes

    KAUST Repository

    Kumar, Rajeev Ananda

    2014-03-25

    The polymerization of isobutylene (IB) to yield highly reactive polyisobutylene (HR PIB) with high exo-olefin content using GaCl3 or FeCl3·diisopropyl ether complexes has been previously reported.1 In an effort to further improve polymerization rates and exo-olefin content, we have studied ethylaluminum dichloride (EADC) complexes with diisopropyl ether, 2-chloroethyl ethyl ether (CEEE), and bis(2-chloroethyl) ether (CEE) as catalysts in conjunction with tert-butyl chloride as initiator in hexanes at different temperatures. All three complexes were readily soluble in hexanes. Polymerization, however, was only observed with CEE. At 0 °C polymerization was complete in 5 min at [t-BuCl] = [EADC·CEE] = 10 mM and resulted in PIB with ∼70% exo-olefin content. Studies on complexation using ATR FTIR and 1H NMR spectroscopy revealed that at 1:1 stoichiometry a small amount of EADC remains uncomplexed. By employing an excess of CEE, exo-olefin contents increased up to 90%, while polymerization rates decreased only slightly. With decreasing temperature, polymerization rates decreased while molecular weights as well as exo-olefin contents increased, suggesting that isomerization has a higher activation energy than β-proton abstraction. Density functional theory (DFT) studies on the Lewis acid·ether binding energies indicated a trend consistent with the polymerization results. The polymerization mechanism proposed previously for Lewis acid·ether complexes1 adequately explains all the findings. © 2014 American Chemical Society.

  9. Evaluation of mechanism for antihypertensive and vasorelaxant effects of hexanic and hydroalcoholic extracts of celery seed in normotensive and hypertensive rats

    Directory of Open Access Journals (Sweden)

    Faezeh Tashakori-Sabzevar

    Full Text Available ABSTRACT Celery (Apium graveolens L., Apiaceae is one of the popular aromatic vegetables and part of the daily diet around the world. In this study, aqueous-ethanolic and hexane extracts of celery seed were prepared and the amount of n-butylphthalide, as an active component, was determined in each extract. Then the effects of hexanic extract on systolic, diastolic, mean arterial blood pressure and heart rate were evaluated in an invasive rat model. The vasodilatory effect and possible mechanisms of above mentioned extracts on aorta ring were also measured. High performance liquid chromatography analysis revealed that hexanic extract contains significantly higher amounts of n-butylphthalide, compared to aqueous-ethanolic extract. The results indicated that hexanic extract significantly decreased the systolic, diastolic, mean arterial blood pressure and heart rate in normotensive and hypertensive rats. Our data revealed that celery seed extract exerts its hypotensive effects through its bradycardic and vasodilatory properties. Moreover, the active components in celery seed extracts could induce their vasodilatory properties through Ca2+ channel blocking activity in endothelial and non-endothelial pathways and particularly by interference with the extra or intracellular calcium.

  10. Production of C(3)/C(4) Olefins from n-Hexane: Conceptual design of a catalytic oxidative cracking process and comparison to steam cracking

    NARCIS (Netherlands)

    Boyadjian, C.A.; Seshan, Kulathuiyer; Lefferts, Leonardus; van der Ham, Aloysius G.J.; van den Berg, Henderikus

    2011-01-01

    A conceptual design of the catalytic oxidative cracking (COC) of hexane as a model compound of naphtha is reported. The design is based on experimental data which are elaborated through a structural design method to a process flow sheet. The potential of COC as an alternative to steam cracking (SC)

  11. Temperature-induced transition of the diffusion mechanism of n-hexane in ultra-thin polystyrene films, resolved by in-situ Spectroscopic Ellipsometry

    NARCIS (Netherlands)

    Ogieglo, Wojciech; Wormeester, Herbert; Wessling, Matthias; Benes, Nieck Edwin

    2013-01-01

    In-situ Spectroscopic Ellipsometry is used to study diffusion of liquid n-hexane in silicon wafer supported 150 nm thick polystyrene films, in the temperature range 16e28 C. In the higher part of this temperature range Case II diffusion is shown to be dominant. In this case the temporal evolution of

  12. Antiproliferative activity of flower hexane extract obtained from Mentha spicata associated with Mentha rotundifolia against the MCF7, KB, and NIH/3T3 cell lines.

    Science.gov (United States)

    Nedel, Fernanda; Begnini, Karine; Carvalho, Pedro Henrique de Azambuja; Lund, Rafael Guerra; Beira, Fátima T A; Del Pino, Francisco Augusto B

    2012-11-01

    This study assessed the antiproliferative effect in vitro of the flower hexane extract obtained from Mentha spicata associated with Mentha rotundifolia against the human breast adenocarcinoma (MCF-7), human mouth epidermal carcinoma (KB), and mouse embryonic fibroblast (NIH 3T3) cell lines, using sulforhodamine B (SRB) assay. A cell density of 2×10(4)/well was seeded in 96-well plates, and samples at different concentrations ranging from 10 to 500 mg/mL were tested. The optical density was determined in an ELISA multiplate reader (Thermo Plate TP-Reader). Results demonstrated that the hexane extract presented antiproliferative activity against both the tumor cell lines KB and MCF-7, presenting a GI(50) (MCF-7=13.09 mg/mL), TGI (KB=37.76 mg/mL), and IL(50) (KB=291.07 mg/mL). Also, the hexane extract presented antiproliferative activity toward NIH 3T3 cells GI(50) (183.65 mg/mL), TGI (280.54 mg/mL), and IL(50) (384.59 mg/mL). The results indicate that the flower hexane extract obtained from M. spicata associated with M. rotundifolia presents an antineoplastic activity against KB and MCF-7, although an antiproliferative effect at a high concentration of the extract was observed toward NIH 3T3.

  13. Process optimisation of microwave-assisted extraction of peony ( Paeonia suffruticosa Andr .) seed oil using hexane-ethanol mixture and its characterisation

    Science.gov (United States)

    Xiaoli Sun; Wengang Li; Jian Li; Yuangang Zu; Chung-Yun Hse; Jiulong Xie; Xiuhua Zhao

    2016-01-01

    Ethanol and hexane mixture agent microwave-assisted extraction (MAE) method was conducted to extract peony (Paeonia suffruticosa Andr.) seed oil (PSO). The aim of the study was to optimise the extraction for both yield and energy consumption in mixture agent MAE. The highest oil yield (34.49%) and lowest unit energy consumption (14 125.4 J g -1)...

  14. Supercritical SC-CO2 and Soxhlet n-Hexane Extract of Tunisian Opuntia ficus indica Seeds and Fatty Acids Analysis

    Directory of Open Access Journals (Sweden)

    Nizar Yeddes

    2012-01-01

    Full Text Available The fatty acids profiles of Tunisian Opuntia ficus indica seeds (spiny and thornless form were investigated. Results of supercritical carbon dioxide (SC-CO2 and soxhlet n-hexane extract were compared. Quantitatively, the better yield was obtained through soxhlet n-hexane: 10.32% (spiny and 8.91% (thornless against 3.4% (spiny and 1.94% (thornless by SC-CO2 extract (T = 40°C, P=180 bar, time = 135 mn, CO2 flow rate = 15 mL·s−1. Qualitatively, the main fatty acids components were the same for the two types of extraction. Linoleic acid was the major compound, SC-CO2: 57.60% (spiny, 59.98% (thornless, soxhlet n-hexane: 57.54% (spiny, 60.66% (thornless, followed by oleic acid, SC-CO2: 22.31% (spiny, 22.40% (thornless, soxhlet n-hexane: 25.28% (spiny, 20.58% (thornless and palmitic acid, SC-CO2: 14.3% (spiny, 12.92% (thornless, soxhlet n-hexane: 11.33% (spiny, 13.08% (thornless. The SC-CO2 profiles fatty acids showed a richness with other minority compounds such as C20:1, C20:2, and C22.The seeds oil was highly unsaturated (US = 4.44–5.25, and the rising temperatures donot affect the selectivity of fatty acids extract by SC-CO2: US = 4.44 (T = 40°C and 4.13 (T = 70°C.

  15. Supercritical SC-CO2 and Soxhlet n-Hexane Extract of Tunisian Opuntia ficus indica Seeds and Fatty Acids Analysis

    Science.gov (United States)

    Yeddes, Nizar; Chérif, Jamila Kalthoum; Jrad, Amel; Barth, Danielle; Trabelsi-Ayadi, Malika

    2012-01-01

    The fatty acids profiles of Tunisian Opuntia ficus indica seeds (spiny and thornless form) were investigated. Results of supercritical carbon dioxide (SC-CO2) and soxhlet n-hexane extract were compared. Quantitatively, the better yield was obtained through soxhlet n-hexane: 10.32% (spiny) and 8.91% (thornless) against 3.4% (spiny) and 1.94% (thornless) by SC-CO2 extract (T = 40°C, P = 180 bar, time = 135 mn, CO2 flow rate = 15 mL·s−1). Qualitatively, the main fatty acids components were the same for the two types of extraction. Linoleic acid was the major compound, SC-CO2: 57.60% (spiny), 59.98% (thornless), soxhlet n-hexane: 57.54% (spiny), 60.66% (thornless), followed by oleic acid, SC-CO2: 22.31% (spiny), 22.40% (thornless), soxhlet n-hexane: 25.28% (spiny), 20.58% (thornless) and palmitic acid, SC-CO2: 14.3% (spiny), 12.92% (thornless), soxhlet n-hexane: 11.33% (spiny), 13.08% (thornless). The SC-CO2 profiles fatty acids showed a richness with other minority compounds such as C20:1, C20:2, and C22.The seeds oil was highly unsaturated (US = 4.44–5.25), and the rising temperatures donot affect the selectivity of fatty acids extract by SC-CO2: US = 4.44 (T = 40°C) and 4.13 (T = 70°C). PMID:22754699

  16. Supercritical SC-CO(2) and Soxhlet n-Hexane Extract of Tunisian Opuntia ficus indica Seeds and Fatty Acids Analysis.

    Science.gov (United States)

    Yeddes, Nizar; Chérif, Jamila Kalthoum; Jrad, Amel; Barth, Danielle; Trabelsi-Ayadi, Malika

    2012-01-01

    The fatty acids profiles of Tunisian Opuntia ficus indica seeds (spiny and thornless form) were investigated. Results of supercritical carbon dioxide (SC-CO(2)) and soxhlet n-hexane extract were compared. Quantitatively, the better yield was obtained through soxhlet n-hexane: 10.32% (spiny) and 8.91% (thornless) against 3.4% (spiny) and 1.94% (thornless) by SC-CO(2) extract (T = 40°C, P = 180 bar, time = 135 mn, CO(2) flow rate = 15 mL·s(-1)). Qualitatively, the main fatty acids components were the same for the two types of extraction. Linoleic acid was the major compound, SC-CO(2): 57.60% (spiny), 59.98% (thornless), soxhlet n-hexane: 57.54% (spiny), 60.66% (thornless), followed by oleic acid, SC-CO(2): 22.31% (spiny), 22.40% (thornless), soxhlet n-hexane: 25.28% (spiny), 20.58% (thornless) and palmitic acid, SC-CO(2): 14.3% (spiny), 12.92% (thornless), soxhlet n-hexane: 11.33% (spiny), 13.08% (thornless). The SC-CO(2) profiles fatty acids showed a richness with other minority compounds such as C(20:1), C(20:2), and C(22).The seeds oil was highly unsaturated (US = 4.44-5.25), and the rising temperatures donot affect the selectivity of fatty acids extract by SC-CO2: US = 4.44 (T = 40°C) and 4.13 (T = 70°C).

  17. High-pressure (vapour + liquid) equilibria for ternary systems composed by {(E)-2-hexenal or hexanal + carbon dioxide + water}: Partition coefficient measurement

    International Nuclear Information System (INIS)

    Bejarano, Arturo; López, Pablo I.; Valle, José M. del; Fuente, Juan C. de la

    2015-01-01

    Highlights: • A new apparatus based on a static–analytic method was assembled in this work. • This work reports high-pressure VLE data of (E)-2-hexenal or hexanal + CO 2 + water. • Data includes (CO 2 + water) partition coefficients of (E)-2-hexenal and hexanal. • High separation factors from water (∼10 4 ) were found especially for (E)-2-hexenal. • The data were obtained at T = (313, 323, and 333) K and pressures from (8 to 19) MPa. - Abstract: A new apparatus based on a static–analytic method assembled in this work was utilised to perform high-pressure (vapour + liquid) equilibria measurements of aqueous ternary systems. This work includes values of isothermal partition coefficients between CO 2 and water of two apple aroma constituents, (E)-2-hexenal and hexanal. Additionally, this work reports new experimental (vapour + liquid) equilibria measurements for the ternary systems (CO 2 + (E)-2-hexenal + water) and (CO 2 + hexanal + water), at fixed liquid phase composition (600 mg · kg −1 ), at temperatures of (313, 323 and 333) K and at pressures from (8 to 19) MPa. Vapour liquid interphase was checked and monitored visually for all the systems studied in this work. No liquid immiscibility was observed at the composition, temperatures and pressures studied. In order to suggest reasonable operation conditions for fractionation of aromas with dense carbon dioxide, partition coefficients of the aroma compounds between CO 2 and water along with their separation factors from water were calculated. Partition coefficients of (E)-2-hexenal between CO 2 and water were in the range of (6 to 91) and where found to be near six times higher than those of hexanal (9 to 17). Very high separation factors from water were observed (∼10 4 ) especially for (E)-2-hexenal. The highest separation factor, for both compounds, was found at a temperature of 313 K and pressures from (12 to 14) MPa

  18. A Limited Role of p53 on the Ability of a Hexane Fraction of American Ginseng to Suppress Mouse Colitis

    Directory of Open Access Journals (Sweden)

    Deepak Poudyal

    2012-01-01

    Full Text Available Ulcerative colitis (UC is debilitating and carries a high colon cancer risk. Apoptosis of inflammatory cells is a key mechanism regulating UC. We have recently shown that American ginseng (AG, and to a greater extent, a Hexane fraction of AG (HAG can cause apoptosis and suppress mouse colitis through a p53-mediated mechanism. Here, we tested the hypothesis that HAG suppresses colitis through a p53 mechanism. We found only a limited impact of p53 in the ability of HAG to induce inflammatory cell apoptosis and suppress mouse colitis in vitro and in vivo. Finally, we asked whether HAG could cause cell cycle arrest of HCT116 colon cancer cells in vitro. Interestingly, HAG caused a G1 arrest of such cells independent of p53 status. Findings are significant because HAG suppresses colitis and associated colon cancer, and mutation in p53 is observed in most colitis-driven colon cancers. Therefore, HAG might be very effective in targeting the inflammatory cells and cancer cells since it induces apoptosis of inflammatory cells and cell cycle arrest in both p53−/− and WT p53 colon cancer cells.

  19. Study of the binary mixtures of {monoglyme + (hexane, cyclohexane, octane, dodecane)} by ECM-average and PFP models

    International Nuclear Information System (INIS)

    Rivas, M.A.; Buep, A.H.; Iglesias, T.P.

    2015-01-01

    Highlights: • Polarization of the real mixture is less than that of the ideal mixture. • Molar excess volume does not exert the dominant effect on the polarization of the mixture. • Similar influence of molecular interactions on the behaviour of excess permittivity. • Excess molar volume is more influenced by the interactions than excess permittivity. - Abstract: Excess molar volumes and excess permittivity of binary mixtures involving monoglyme and alkanes, such as n-hexane, cyclohexane, n-octane and n-dodecane, were calculated from density and relative permittivity measurements for the entire composition range at several temperatures (288.15, 298.15 and 308.15) K and atmospheric pressure. The excess permittivity was calculated on the basis of a recent definition considering the ideal volume fraction. Empirical equations for describing the experimental data in terms of temperature and concentration are given. The experimental values of permittivity have been compared with those estimated by well-known models from literature. The results have indicated that better predictions are obtained when the volume change on mixing is incorporated in these calculations. The contribution of interactions to the excess permittivity was analysed by means of the ECM-average model. The Prigogine–Flory–Patterson (PFP) theory of the thermodynamics of solutions was used to shed light on the contribution of interactions to the excess molar volume. The work concludes with an interpretation of the information given by the theoretical models and the behaviour of both excess magnitudes

  20. First observation of alkyne radical anions by electron spin resonance spectroscopy: Hexyne/n-hexane mixed crystals

    International Nuclear Information System (INIS)

    Matsuura, K.; Muto, H.

    1991-01-01

    The radical anions of alkynes have been first observed by electron spin resonance spectroscopy following alkene anions previously studied. Hexyne radical anions were formed in 1-, 2-, or 3-hexyne/n--hexane mixed crystals irradiated at 4.2 or 77 K. The characters of the anions were as follows; (a) the α-proton hyperfine coupling is very large (∼4.5 mT for the 1-hexyne anion), (b) the β-proton couplings are very small (∼1.0 mT for C--H β proton with the conformational angle of 0 degree), and (c) the radicals show a negative g shift (2.0014). From these observations, it was found that the anions have a nonlinear(bent) molecule structure in the anticonfiguration (trans C--C≡C--C) with the bend angle ∼60 degree, and that the unpaired electron orbital is approximately composed of the anticombination of the sp 2 hybrid orbitals of the C≡C carbon atoms. A discussion based on complete neglect of differential overlap (CNDO) molecular orbital (MO) calculations was given for the observed negative g shift, which was shown to be characteristic of the alkyne anions which have a high-lying unpaired electron orbital and an antibonding 2p--2p π carbon orbital just above it on the upper energy side

  1. Gas barrier properties of hydrogenated amorphous carbon films coated on polyethylene terephthalate by plasma polymerization in argon/n-hexane gas mixture

    Energy Technology Data Exchange (ETDEWEB)

    Polonskyi, Oleksandr; Kylián, Ondřej, E-mail: ondrej.kylian@gmail.com; Petr, Martin; Choukourov, Andrei; Hanuš, Jan; Biederman, Hynek

    2013-07-01

    Hydrogenated amorphous carbon thin films were deposited by RF plasma polymerization in argon/n-hexane gas mixture on polyethylene terephthalate (PET) foils. It was found that such deposited films may significantly improve the barrier properties of PET. It was demonstrated that the principal parameter that influences barrier properties of such deposited films towards oxygen and water vapor is the density of the coatings. Moreover, it was shown that for achieving good barrier properties it is advantageous to deposit coatings with very low thickness. According to the presented results, optimal thickness of the coating should not be higher than several tens of nm. - Highlights: • a-C:H films were prepared by plasma polymerization in Ar/n-hexane atmosphere. • Barrier properties of coatings are dependent on their density and thickness. • Highest barrier properties were observed for films with thickness 15 nm.

  2. Evaluation of (vapor + liquid) equilibria for the binary systems (1-octanol + cyclohexane) and (1-octanol + n-hexane), at low alcohol compositions

    International Nuclear Information System (INIS)

    Ovejero, Gabriel; Dolores Romero, M.; Diez, Eduardo; Lopes, Tania; Diaz, Ismael

    2008-01-01

    Isobaric (vapor + liquid) equilibrium at p = 101.32 kPa of pressure has been determined for the systems (1-octanol + cyclohexane) and (1-octanol + n-hexane), at low alcohol mole fractions. These data were satisfactorily correlated, using ASPEN PLUS commercial software, with Wilson, NRTL, and UNIQUAC activity coefficient models to obtain the binary interaction parameters of both mixtures. Also, UNIFAC group contribution method was employed to predict the equilibrium of both mixtures. With regression values an accurate knowledge of (vapor + liquid) equilibrium for both mixtures can be reached in a range of 1-octanol mole fractions less than 0.1. UNIFAC method provides acceptable results for (1-octanol + n-hexane) system but not for (1-octanol + cyclohexane) system

  3. Evaluation of (vapor + liquid) equilibria for the binary systems (1-octanol + cyclohexane) and (1-octanol + n-hexane), at low alcohol compositions

    Energy Technology Data Exchange (ETDEWEB)

    Ovejero, Gabriel [Grupo de Catalisis y Procesos de Separacion (CyPS), Departamento de Ingenieria Quimica, Facultad de C. Quimicas, Universidsad Complutense de Madrid, Avda. Complutense s/n, 28040 Madrid (Spain)], E-mail: govejero@quim.ucm.es; Dolores Romero, M.; Diez, Eduardo; Lopes, Tania; Diaz, Ismael [Grupo de Catalisis y Procesos de Separacion (CyPS), Departamento de Ingenieria Quimica, Facultad de C. Quimicas, Universidsad Complutense de Madrid, Avda. Complutense s/n, 28040 Madrid (Spain)

    2008-11-15

    Isobaric (vapor + liquid) equilibrium at p = 101.32 kPa of pressure has been determined for the systems (1-octanol + cyclohexane) and (1-octanol + n-hexane), at low alcohol mole fractions. These data were satisfactorily correlated, using ASPEN PLUS commercial software, with Wilson, NRTL, and UNIQUAC activity coefficient models to obtain the binary interaction parameters of both mixtures. Also, UNIFAC group contribution method was employed to predict the equilibrium of both mixtures. With regression values an accurate knowledge of (vapor + liquid) equilibrium for both mixtures can be reached in a range of 1-octanol mole fractions less than 0.1. UNIFAC method provides acceptable results for (1-octanol + n-hexane) system but not for (1-octanol + cyclohexane) system.

  4. Superior activity of non-interacting close acidic protons in Al-rich Pt/H-*BEA zeolite in isomerization of n-hexane

    Czech Academy of Sciences Publication Activity Database

    Sazama, Petr; Kaucký, Dalibor; Morávková, Jaroslava; Pilař, Radim; Klein, Petr; Pastvová, Jana; Tabor, Edyta; Sklenák, Štěpán; Jakubec, Ivo; Mokrzycki, Lukasz

    2017-01-01

    Roč. 533, MAR 2017 (2017), s. 28-37 ISSN 0926-860X R&D Projects: GA ČR GA15-12113S; GA MŠk(CZ) LM2015073 Institutional support: RVO:61388955 ; RVO:61388980 Keywords : Isomerization * Alkanes Hexane * Zeolites * Al-rich beta (*BEA) * Mordenite Subject RIV: CF - Physical ; Theoretical Chemistry; CA - Inorganic Chemistry (UACH-T) OBOR OECD: Physical chemistry; Inorganic and nuclear chemistry (UACH-T) Impact factor: 4.339, year: 2016

  5. Excess molar volumes and deviation in viscosities of binary liquid mixtures of acrylic esters with hexane-1-ol at 303.15 and 313.15K

    OpenAIRE

    Patil, Sujata S.; Mirgane, Sunil R.; Arbad, Balasaheb R.

    2014-01-01

    Densities and viscosities for the four binary liquid mixtures of methyl acrylate, ethyl acrylate, butyl acrylate and methyl methacrylate with hexane-1-ol at temperatures 303.15 and 313.15 K and at atmospheric pressure were measured over the entire composition range. These values were used to calculate excess molar volumes and deviation in viscosities which were fitted to Redlich–Kister polynomial equation. Recently proposed Jouyban Acree model was also used to correlate the experimental value...

  6. Comparative Study of Various Preparation Methods of CuO–CeO2 Catalysts for Oxidation of n–Hexane and iso–Octane

    Directory of Open Access Journals (Sweden)

    Ashutosh Mishra

    2013-03-01

    Full Text Available The complete oxidation of n-Hexane and iso-Octane was studied individually in a fixed bed tubular flow reactor over CuO-CeO2 catalysts synthesized via four different methods namely urea-nitrate combustion method, urea gelation/co-precipitation method, citric acid sol-gel method and co-impregnation method. Laser diffraction was employed in catalysts characterization. The results obtained from the complete conversion of n-Hexane and iso-Octane revealed that the CuO-CeO2 catalysts prepared by urea-nitrate combustion method (UNC showed the best performance than the catalysts prepared by other methods used in the present investigation. CuO-CeO2 catalysts prepared by UNC method achieve total n-Hexane and iso-Octane conversion to CO2 at lower temperatures of 280 0C and 340 0C respectively due to the larger surface area of the catalysts which increases the specific rate of reaction. © 2013 BCREC UNDIP. All rights reservedReceived: 30th October 2012; Revised: 30th November 2012; Accepted: 3rd December 2012[How to Cite: A. Mishra, B.D. Tripathi, A.K. Rai, R. Prasad (2013. Comparative Study of Various Preparation Methods of CuO–CeO2 Catalysts for Oxidation of n–Hexane and iso–Octane. Bulletin of Chemical Reaction Engineering & Catalysis, 7(3: 172-178. (doi:10.9767/bcrec.7.3.4076.172-178][Permalink/DOI: http://dx.doi.org/10.9767/bcrec.7.3.4076.172-178 ] View in  |

  7. Evaluation of the acute dermal exposure of the ethanolic and hexanic extracts from leaves of Schinus molle var. areira L. in rats.

    Science.gov (United States)

    Bras, Cristina; Gumilar, Fernanda; Gandini, Norberto; Minetti, Alejandra; Ferrero, Adriana

    2011-10-11

    Schinus molle var. areira L. (Anacardiaceae) is employed in herbal medicine for many conditions, including respiratory, urinary and menstrual disorders, and as a digestive stimulant, diuretic, astringent and antidepressant. It is also known for its topical use as wound healer, antiseptic, for skin disorders and as repellent and insecticide. In the present work, the acute dermal exposure to ethanolic and hexanic extracts from leaves of Schinus molle var. areira was studied in rats. A single dose of 2000 mg/kg of body weight of ethanolic and hexanic extracts from leaves was applied on the shaved skin of male and female rats. After 24h of exposure, the patch was removed and any sign of irritation was recorded. Behavioral and functional parameters in a functional observational battery and motor activity in an open field were assessed after the exposure to the extracts. Then, after 14 days of observation, animals were retested. Finally, histopathological studies were conducted on several organs. Slight signs of erythema and edema were observed in the skin site of exposure, but they disappeared after 48 h. The exposure to the hexanic extract produced an increase in parameters of activity, rearing and arousal assessed in the functional observational battery, which reversed after 14 days. On the other hand, the ethanolic extract caused an increase in locomotor activity, reflected in a higher number of rearings performed in the open field in the evaluation carried out on Day 14. No histopathological alterations were detected in the analyzed organs. The results show that the acute dermal exposure of the ethanolic and hexanic extracts from leaves of Schinus molle var. areira only causes a slight and reversible skin irritation, and a mild stimulatory effect in rats. All these indicate that the topical use of these extracts would be safe. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  8. [μ2-Bis(diphenylphosphanylhexane]bis[undecacarbonyl-triangulo-triruthenium(3 Ru—Ru] hexane monosolvate: crystal structure and Hirshfeld surface analysis

    Directory of Open Access Journals (Sweden)

    Omar bin Shawkataly

    2017-11-01

    Full Text Available In the title cluster complex hexane solvate, [Ru6(C30H32P2(CO22]·C6H14, two Ru3(CO11 fragments are linked by a Ph2P(CH26PPh2 bridge with the P atoms equatorially disposed with respect to the Ru3 triangle in each case; the hexane solvent molecule is statistically disordered. The Ru...Ru distances span a relatively narrow range, i.e. 2.8378 (4 to 2.8644 (4 Å. The hexyl chain within the bridge has an all-trans conformation. In the molecular packing, C—H...O interactions between cluster molecules, and between cluster and hexane solvent molecules lead to a three-dimensional architecture. In addition, there are a large number of C[triple-bond]O...π(arene interactions in the crystal. The importance of the carbonyl groups in establishing the packing is emphasized by the contribution of 53.4% to the Hirshfeld surface by O...H/H...O contacts.

  9. Effects of high-pressure process on kinetics of leaching oil from soybean powder using hexane in batch systems.

    Science.gov (United States)

    Uhm, Joo Tae; Yoon, Won Byong

    2011-08-01

    Mass transfer models of leaching oil from soybean (Glycine max) flour with hexane after high-pressure process (HPP) treatment were developed. High pressure (450 MPa) was applied to the soybean flour (mean diameter of flour particle: 365 μm) for 30 min before leaching the oil components in the solvent. The ratio of solvent (volume, mL) to soybean flour (mass, g), such as 1:10 and 1:20, was employed to characterize the effect of solvent ratio on the leaching rate in the batch type of extraction process. Ultraviolet absorbance at 300 nm was used to monitor the extraction rate. Saturation solubility (C(AS)) was determined to be 21.73 kg/m³. The mass transfer coefficients (k) were determined based on the 1st- and 2nd-order kinetic models. The 2nd kinetic model showed better fit. The HPP treatment showed a higher extraction rate and yield compared to the control, while the amount of solvent did not affect the extraction rate and yield. The scanning electron microscope showed that HPP-treated soybean particles included more pores than the untreated. The pores observed in the HPP-treated soybean flours might help increase the mass transfer rate of solvent and solute in the solid matrix. High-pressure processing can help increase the extraction rate of oil from the soybean flour operated in batch systems. The conventional solid to solvent ratio (1:20) used to extract oil composition from the plant seed did not help increase the amount of oil extracted from the soybean flour. © 2011 Institute of Food Technologists®

  10. Seed oil extraction from red prickly pear using hexane and supercritical CO2 : assessment of phenolic compound composition, antioxidant and antibacterial activities.

    Science.gov (United States)

    Koubaa, Mohamed; Mhemdi, Houcine; Barba, Francisco J; Angelotti, Armel; Bouaziz, Fatma; Chaabouni, Semia Ellouz; Vorobiev, Eugène

    2017-01-01

    Investigating Opuntia species for their seed oil content is of much importance owing to their potential use for food and in cosmetic applications. These oils have an important content in unsaturated fatty acids as well as antioxidant compounds (e.g. polyphenols, vitamin E), which have been associated with the prevention of some chronic diseases. Moreover, Opuntia stricta oils possess important antimicrobial activities. For instance, the main focus of this study was to compare the effectiveness of conventional (hexane extraction) and novel (supercritical (SC)-CO 2 ) extraction methods for the recovery of oil and phenolic compounds from O. stricta seeds. The oil yield of both extracts was then compared and the polyphenol content and composition of both extracts were determined by liquid chromatography-high-resolution mass spectrometry. Additionally, antioxidant (DPPH assay) and antimicrobial activities (disc diffusion method) of O. stricta seed oils were determined. The oil yield (based on Soxhlet's method) of O. stricta seeds was determined using SC-CO 2 (49.9 ± 2.2%), and hexane (49.0 ± 1.5%). Although obtaining similar oil extraction yields using the two methods, the extracted oil using SC-CO 2 was more enriched in polyphenols (172.2 ± 11.9 µg gallic acid equivalents (GAE) g -1 oil) than that extracted using hexane (76.0 ± 6.9 µg GAE g -1 of oil). Polyphenol profiles showed that the SC-CO 2 process led to the yield of more compounds (45) than that using hexane extraction (11). Moreover, the antioxidant and antimicrobial activities of SC-CO 2 extract showed a high percentage of inhibition. SC-CO 2 extraction of O. stricta seed oil led to extraction of oil with a similar yield to that with hexane extraction, but with higher polyphenol content. The extract containing polyphenols exhibited high antioxidant and antibacterial properties, demonstrating their great potential as feedstock for high-oil quality. © 2016 Society of Chemical Industry. © 2016 Society of

  11. Testicular atrophy and loss of nerve growth factor-immunoreactive germ cell line in rats exposed to n-hexane and a protective effect of simultaneous exposure to toluene or xylene

    Energy Technology Data Exchange (ETDEWEB)

    Nylen, P; Johnson, A C; Hoeglund, G; Ebendal, T; Eriksdotter-Nilsson, M; Henschen, A; Olson, L; Hansson, T; Kronevi, T; Kvist, U

    1989-07-01

    Testicular and germ cell line morphology in rats were studied 2 weeks, 10 months and 14 months after cessation of a 61-day inhalation exposure to 1000 ppm n-hexane. Androgen biosynthetic capacity of testis, testosterone blood concentration, vas deferens morphology and noradrenaline (NA) concentration, epididymal sperm morphology, and fertility were also studied. Severe testicular atrophy involving the seminiferous tubules with loss of the nerve growth factor (NGF) immunoreactive germ cell line was found. Total loss of the germ cell line was found in a fraction of animals up to 14 months post-exposure, indicating permanent testicular damage. No impairment of androgen synthesis or androgen dependent accessory organs was observed. Simultaneous administration of 1000 ppm n-hexane and 1000 ppm toluene, or 1000 ppm n-hexane and 1000 ppm xylene, did not cause germ cell line alterations or testicular atrophy. Toluene and xylene were thus found to protect from n-hexane induced testicular atrophy. (orig.).

  12. Vapor pressure data for ethyl-2-methylbutyrate, hexanal and (E)-2-hexenal at a pressure range of (25 to 190) kPa

    International Nuclear Information System (INIS)

    Meneses, David A.; Bejarano, Arturo; Fuente, Juan C. de la

    2014-01-01

    Highlights: • Vapor pressures of three pure apple aroma constituents were measured. • Measurements were made over the temperature range of (362.1 to 429.9) K. • Constants of Antoine and Wagner type equations were fitted to the experimental data. • Relative deviations (rmsd) from the three vapor-pressure equations were <0.9%. • Contrast with literature showed discrepancies <9% among them and with this work. - Abstract: The saturated vapor pressures of pure ethyl-2-methylbutyrate, hexanal and (E)-2-hexenal, which are volatile compounds characteristic of apple aroma, were measured with a dynamic recirculation apparatus at a pressure range of (24.5 to 190.0) kPa. Measurements were made over the temperature range of (362.1 to 429.9) K for ethyl-2-methylbutyrate, (358.1 to 425.8) K for hexanal, and (373.5 to 446.2) K for (E)-2-hexenal. The maximum likelihood method was used to estimate the parameters of the Antoine equation, whereas the parameters of an extended Antoine equation and the Wagner equation were determined by non linear least square method. The three models showed root mean square deviations (rmsd) of 0.29%, 0.28%, and 0.27% for ethyl-2-methylbutyrate, 0.58%, 0.48%, and 0.38% for hexanal, and 0.89%, 0.62% and 0.36% for (E)-2-hexenal, respectively. Additionally, the experimental data and correlation were compared with those available in the literature

  13. Microwave-assisted extraction through an aqueous medium and simultaneous cleanup by partition on hexane for determining pesticides in agricultural soils by gas chromatography: A critical study

    International Nuclear Information System (INIS)

    Fuentes, Edwar; Baez, Maria E.; Reyes, Dana

    2006-01-01

    A simple microwave-assisted extraction and partitioning method (MAEP) using water-acetonitrile and n-hexane for desorption and simultaneous partitioning, respectively, together with gas chromatography (GC) was studied to determine representative pesticides (trifluralin, metolachlor, chlorpyriphos and triadimefon) with a broad range of physico-chemical properties in agricultural soils. Three points were considered crucial in this study: instrumental and sample-associated factors affecting extraction of the target compounds were studied through experimental design; the spiking procedure at trace levels was carried out to reproduce the solute-soil sorption taking place in the environment as closely as possible; and results were analyzed taking into account the adsorption behaviour of the compounds on different kinds of soils. The complete analytical procedure proposed consisted of the MAEP of pesticides from 1.0 g of soil with 1 mL of 1:1 water/acetonitrile mixture, and 5 mL of hexane for trapping. The microwave heating program applied was 2 min at 250 W and 10 min at 900 W, and 130 deg. C maximum temperature. After extraction, the hexane layer was evaporated to dryness; the residue was re-dissolved and directly analyzed by gas chromatography electron capture detection (GC-ECD). Clean chromatograms were obtained without any additional cleanup step. Besides the four pesticides used to optimise MAEP, the method was applied to determine an additional group of pesticides (triallate, acetochlor, alachlor, endosulphan I and II, endrin, methoxychlor and tetradifon) in different soils. Most of the compounds studied were recovered in good yields with relative standard deviations (R.S.D.s) below 9% and detection limits ranged from 0.004 to 0.036 μg g -1 . The described method is efficient and fast to determine hydrophobic pesticides at ng g -1 level in soil with different clay-to-organic matter ratios

  14. Microwave-assisted extraction through an aqueous medium and simultaneous cleanup by partition on hexane for determining pesticides in agricultural soils by gas chromatography: A critical study

    Energy Technology Data Exchange (ETDEWEB)

    Fuentes, Edwar [Departamento de Quimica Inorganica y Analitica, Facultad de Ciencias Quimicas y Farmaceuticas, Universidad de Chile, Santiago, Casilla 233 (Chile)]. E-mail: edfuentes@ciq.uchile.cl; Baez, Maria E. [Departamento de Quimica Inorganica y Analitica, Facultad de Ciencias Quimicas y Farmaceuticas, Universidad de Chile, Santiago, Casilla 233 (Chile); Reyes, Dana [Departamento de Quimica Inorganica y Analitica, Facultad de Ciencias Quimicas y Farmaceuticas, Universidad de Chile, Santiago, Casilla 233 (Chile)

    2006-09-25

    A simple microwave-assisted extraction and partitioning method (MAEP) using water-acetonitrile and n-hexane for desorption and simultaneous partitioning, respectively, together with gas chromatography (GC) was studied to determine representative pesticides (trifluralin, metolachlor, chlorpyriphos and triadimefon) with a broad range of physico-chemical properties in agricultural soils. Three points were considered crucial in this study: instrumental and sample-associated factors affecting extraction of the target compounds were studied through experimental design; the spiking procedure at trace levels was carried out to reproduce the solute-soil sorption taking place in the environment as closely as possible; and results were analyzed taking into account the adsorption behaviour of the compounds on different kinds of soils. The complete analytical procedure proposed consisted of the MAEP of pesticides from 1.0 g of soil with 1 mL of 1:1 water/acetonitrile mixture, and 5 mL of hexane for trapping. The microwave heating program applied was 2 min at 250 W and 10 min at 900 W, and 130 deg. C maximum temperature. After extraction, the hexane layer was evaporated to dryness; the residue was re-dissolved and directly analyzed by gas chromatography electron capture detection (GC-ECD). Clean chromatograms were obtained without any additional cleanup step. Besides the four pesticides used to optimise MAEP, the method was applied to determine an additional group of pesticides (triallate, acetochlor, alachlor, endosulphan I and II, endrin, methoxychlor and tetradifon) in different soils. Most of the compounds studied were recovered in good yields with relative standard deviations (R.S.D.s) below 9% and detection limits ranged from 0.004 to 0.036 {mu}g g{sup -1}. The described method is efficient and fast to determine hydrophobic pesticides at ng g{sup -1} level in soil with different clay-to-organic matter ratios.

  15. Anxiolytic-like actions of the hexane extract from leaves of Annona cherimolia in two anxiety paradigms: possible involvement of the GABA/benzodiazepine receptor complex.

    Science.gov (United States)

    López-Rubalcava, C; Piña-Medina, B; Estrada-Reyes, R; Heinze, G; Martínez-Vázquez, M

    2006-01-11

    A hexane extract of leaves of Annona cherimolia produced anxiolytic-like actions when administered to mice and tested in two animal models of anxiety: the mouse avoidance exploratory behavior and the burying behavior tests. In order to discard unspecific drug-actions on general activity, all treatments studied in the anxiety paradigms were also analyzed in the open field test. Results showed that A. cherimolia induced anxiolytic-like actions at the doses of 6.25, 12.5, 25.0 and 50.0 mg/kg. Picrotoxin (0.25 mg/kg), a GABA-gated chloride ion channel blocker, antagonized the anxiolytic-like actions of A. cherimolia, while a sub-effective dose of muscimol (0.5 mg/kg), a selective GABA(A) receptor agonist, facilitated the effects of a sub-optimal dose of A. cherimolia (3.12 mg/kg). Thus, the involvement of the GABA(A) receptor complex in the anxiolytic-like actions of A. cherimolia hexane extract is suggested. In addition the extract was also able to enhance the duration of sodium pentobarbital induced sleeping time. Taken together, results indicate that the hexane extract of A. cherimolia has depressant activity on the Central Nervous System and could interact with the GABA(A) receptor complex. On the other hand, the chromatographic separation of this extract led to the isolation of palmitone, and beta-sitosterol as major constituents. In addition a GC-MS study of some fractions revealed the presence of several compounds such beta-cariophyllene, beta-selinene, alpha-cubebene, and linalool that have been reported to show effects on behavior that could explain some of the extract effects.

  16. Effect of the hexane extract of Piper auritum on insulin release from β-cell and oxidative stress in streptozotocin-induced diabetic rat.

    Science.gov (United States)

    Gutierrez, Rosa Martha Perez

    2012-10-01

    The large-leafed perennial plant Piper auritum known as Hoja Santa, is used for its leaves that because of their spicy aromatic scent and flavor have an important presence in Mexican cuisine, and in many regions, this plant is known for its therapeutic properties. In the present study, we investigated the effect of hexane, chloroform and methanol extracts from Piper auritum on cell culture system and the effect in streptozotocin-induced type 1 diabetic rats treated by 28 days on the physiological, metabolic parameters and oxidative stress. The hexane extract of P. auritum (HS) treatment significantly reduced the intake of both food, water and body weight loss as well as levels of blood glucose, serum cholesterol, triglycerides and increase HDL-cholesterol. After 4-week administration of HS antioxidant enzyme as SOD, CAT, GSH, GPx in pancreas were determined. These enzyme increased significantly compared with those of the diabetic rats control and normal animals. For all estimated, the results of HS treated groups leading to a restoration of the defense mechanism. The treatment also improves pancreatic TBARS-reactive substance level and serum NO and iNOS. To determine the insulin releasing activity, after extract treatment the serum and pancreatic sections were processed for examination of insulin-releasing activity using an immunocytochemistry kit. The results showed that administration of the hexane extract (200 and 400 mg/kg) exhibited a significant increase in serum and pancreas tissue insulin. Administration of streptozotocin decreased the insulin secretory activity in comparison with intact rats, but treatment with the HS extract increased significantly the activity of the beta cells in comparison with the diabetic control rats. The extract decreased serum glucose in streptozotocin-induced diabetic rats and increased insulin release from the beta cells of the pancreas. In cultured RIN-5F cells, we examined whether hexane extract of P. auritum would protect the

  17. Hydroformylation of olefins and reductive carbonylation of aryl halides with syngas formed ex situ from dehydrogenative decarbonylation of hexane-1,6-diol

    DEFF Research Database (Denmark)

    Christensen, Stig Holden; Olsen, Esben Paul Krogh; Rosenbaum, Jascha

    2014-01-01

    A variety of primary alcohols have been investigated as convenient substrates for the ex situ delivery of carbon monoxide and molecular hydrogen in a two-chamber reactor. The gaseous mixture is liberated in one chamber by an iridium-catalysed dehydrogenative decarbonylation of the alcohol...... and then consumed in the other chamber in either a rhodium-catalysed hydroformylation of olefins or a palladium-catalysed reductive carbonylation of aryl halides. Hexane-1,6-diol was found to be the optimum alcohol for both reactions where moderate to excellent yields were obtained of the product aldehydes...

  18. Synthesis and Evaluation of Bicyclo[3.1.0]hexane-Based UDP-Galf Analogues as Inhibitors of the Mycobacterial Galactofuranosyltransferase GlfT2

    Directory of Open Access Journals (Sweden)

    Todd L. Lowary

    2016-08-01

    Full Text Available UDP-galactofuranose (UDP-Galf is the donor substrate for both bifunctional galactofuranosyltransferases, GlfT1 and GlfT2, which are involved in the biosynthesis of mycobacterial galactan. In this paper, a group of UDP-Galf mimics were synthesized via reductive amination of a bicyclo[3.1.0]hexane-based amine by reacting with aromatic, linear, or uridine-containing aldehydes. These compounds were evaluated against GlfT2 using a coupled spectrophotometric assay, and were shown to be weak inhibitors of the enzyme.

  19. COMPARATIVE STUDY OF CHEMICAL COMPOSITION, PHYSICO-CHEMICAL AND ANTIOXIDANT PROPERTIES OF OILS EXTRACTED BY TRADITIONAL AND HEXANE METHODS FROM TERMINALIA CATAPPA L. KERNELS

    Directory of Open Access Journals (Sweden)

    Bérenger A. L. Ladele

    2017-10-01

    Full Text Available The comparative study of physico-chemical characteristics of Terminalia catappa L. kernel oils extracted by two methods has been done. The oil yields were 28.13 % and 61.78 % respectively for traditional and hexane methods and the fatty acid profiles showed palmitic acid (40.79 % and 40.03 % respectively oleic acid (25.55 % and 26.09 % respectively, linoleic acid (26.72 % and 26.64 % respectively and stearic acid (4.35 % and 4.49 % respectively as major components. The oils extracted by the two ways showed similar physico-chemical properties, good calorific values and non-toxicity against Artemia salina L. Oil obtained by traditional method exhibited more antioxidant capacity (1.40 than the hexane one (0.15. This traditional method helps to extract 45 % of the total oil. It gives oil free of organic solvent, with good physico-chemical properties that could be useful as edible oil and for industrial applications.

  20. Fabrication of Hydrophobic Membrane for the Separation of n-Hexane/Water Mixture Using Novel Oleophilic Nanoparticle and Kevlar Fabric, as a Superior Support

    Directory of Open Access Journals (Sweden)

    Hanieh Karimnezhad

    2017-07-01

    Full Text Available The fabrication of functionalized membranes with hydrophobic/oleophilic surfaces for the elimination of n-hexane from water using para-aminobenzoate alumoxane, boehmite-epoxide and a novel nanoparticle, i.e., Stearate Alumoxane by a simple coating technique, is reported here. FTIR was used to characterize nanoparticles. SEM and contact angle measurement analyses were used to identify the nanocomposite membranes. The concentrations of oil in permeate and retentate were measured by UV/vis spectrophotometer. The morphology of Stearate alumoxane nanoparticles was investigated by means of SEM images. The composed film of nanoparticles on the Kevlar fabric was hydrophobic with water contact angle of ~ 145° and oleophilic with oil contact angle of ~ 0º. In addition, the membranes retained stable hydrophobicity and high separation efficiency even after employing for 6 times. Applying these properties, a setup was considered using the functionalized Kevlar fabric to separate oil through down to a collector and leave water drops. Our batch filtration system was exclusively gravity-driven. The achieved separation system can separate the oily water mixture (with the concentration of 20 % (v/v n-hexane in water, effectively with a separation efficiency of 84%.

  1. Response surface optimization for the transesterification of karanja oil using immobilized whole cells of Rhizopus oryzae in n-hexane system

    Energy Technology Data Exchange (ETDEWEB)

    Ganesan, Devanesan; Rajendran, Aravindan; Thangavelu, Viruthagiri [Annamalai University, Department of Chemical Engineering, Faculty of Engineering and Technology, Biochemical Engineering Laboratory, Annamalai Nagar, Tamil Nadu (India)

    2012-03-15

    Non-edible oils represent one of the most viable alternative feed stocks for the production of large volumes of biodiesel at cheaper cost in tropical countries. The objective of the present study is to investigate the ability of the immobilized whole cells of Rhizopus oryzae MTCC 262 to catalyze the biodiesel production from karanja oil in n-hexane system. Response surface methodology was employed to evaluate the effects of synthesis parameters, such as molar ratio of oil to alcohol, reaction temperature and reaction time on percentage biodiesel (methyl esters) yield. Transesterification was performed in shake flasks containing immobilized cells in the reaction mixture with 10% oil weight of n-hexane. The quadratic effects of molar ratio of oil to alcohol and reaction time proved to be the significant at 1% and 5% levels, respectively. The optimum synthesis conditions were found to be: molar ratio of oil to alcohol 1:2.73, reaction temperature 41.39 C and reaction time 73.97 h. Biodiesel yield (methyl ester) was 75.98 (wt.%) under the optimal conditions and the subsequent verification experiments with biodiesel yield of 78.0 (wt.%) confirmed the validity of the proposed model. (orig.)

  2. Anticholinergic, antihistaminic, and antiserotonergic activity of n-hexane extract of Zanthoxylum alatum seeds on isolated tissue preparations: An ex vivo study.

    Science.gov (United States)

    Saikia, Beenita; Barua, Chandana Choudhury; Haloi, Prakash; Patowary, Pompy

    2017-01-01

    The aim of this study was to evaluate anticholinergic, antihistaminic, and antiserotonergic activity of the n-hexane extract of the seeds of Zanthoxylum alatum (ZAHE) on isolated ileum of rat and guinea pig and fundus of rat. ZAHE was prepared using soxhlet extraction and cumulative concentration response curves were constructed using various doses on the tissues for acetylcholine (ACh), 5-hydroxytryptamine (5-HT), and histamine with or without n-hexane extract. Atropine, ketanserin, and pheniramine maleate were used as antagonists for ACh, serotonin, and histamine, respectively. ZAHE-induced concentration-dependent inhibition of isolated ileum and fundus in rat and ileum of guinea pig. The half maximal effective concentration (EC 50 ) of ACh in the presence of atropine (10 -6 M; P pheniramine maleate (10 -6 M; P < 0.01) and ZAHE (300 μg/ml; P < 0.01 and 1000 μg/ml; P < 0.05) was also significantly higher than EC 50 of histamine alone. From the study, it was observed that ZAHE shows significant anticholinergic, antiserotonergic, and antihistaminic activity. The study provides sufficient evidence that the seeds can be used in gastric disorders, cough, chest infection, etc., as per folklore claims.

  3. Chemical composition of essential oil and hexane extract and antioxidant activity of various extracts of Acmella uliginosa (Sw. Cass flowers from Indonesia

    Directory of Open Access Journals (Sweden)

    Askal Maimulyanti

    2016-07-01

    Full Text Available Medicinal plants are rich sources of natural antioxidant which are used in the prevention and treatment of disease like artherosclerosis, heart stroke, diabetes and cancer and to delay the process of aging. Acmella uliginosa (Sw. Cass is an edible herb traditionally used in the treatment of many diseases. Analysis of volatile components in the flower extract used gas chromatography-mass spectrometry. The results showed the main components of the essential oil were caryophyllene (21.27%, caryophyllene oxide (15.49%, and 3-carene (10.73%. The main components of the hexane extract were N-isobutyl-2E,6Z,8E-decatrienamide (37.80%, α-pinene (4.98% and hexadacanoic acid-methyl ester (4.78%. The antioxidant activity of A. uliginosa (Sw. Cass flower from Indonesia was determined using 1,1, diphenyl-2-picryl hydrazine (DPPH free radical scavenging assay. The IC50 (defined as the total antioxidant necessary to decrease the initial DPPH radical by 50% of extracts was calculated. A comparative study determined that A. uliginosa (Sw. Cass in methanol extract showed higher antioxidant potential (IC50 = 96.83 μg/mL compared to ethyl acetate extract (IC50 = 123.46 μg/mL and n-hexane extract (905.92 μg/mL against DPPH free radicals.

  4. Thermal desorption studies of heterogeneous catalytic reactions--3. The stepwise mechanism of n-hexane dehydrocyclization (to benzene) over a Pt/Al/sub 2/O/sub 3/ catalyst

    Energy Technology Data Exchange (ETDEWEB)

    Rozanov, V V; Sklyarov, A V

    1978-12-01

    The interactions of n-hexane, benzene, and the possible intermediates of n-hexane dehydrocyclization by different mechanisms with a 0.68Vertical Bar3< Pt/..gamma..-Al/sub 2/O/sub 3/ catalyst and over pure ..gamma..-Al/sub 2/O/sub 3/ were studied by recording thermal desorption (TD) spectra of these compounds. The kinetic parameters, calculated from the TD data, for benzene formation from n-hexane, 1-hexene and 1,5-hexadiene coincided, suggesting a common reaction route involving these three species. TD spectra of methylcyclopentane indicated that this compound is not an important intermediate in n-hexane dehydrocyclization. These findings suggested that the process starts by two-step dehydrogenation of n-hexane to 1-hexene and 1,5-hexadiene and is followed by a rate-limiting step of hexadiene conversion. Formation of cyclohexadiene, the immediate precursor of benzene, occurs either by direct cyclization of hexadiene or via cyclohexene or hexatriene intermediates, but these routes are alternative rather than competing under the conditions studied.

  5. Experimental study and thermodynamic modeling for determining the effect of non-polar solvent (hexane)/polar solvent (methanol) ratio and moisture content on the lipid extraction efficiency from Chlorella vulgaris.

    Science.gov (United States)

    Malekzadeh, Mohammad; Abedini Najafabadi, Hamed; Hakim, Maziar; Feilizadeh, Mehrzad; Vossoughi, Manouchehr; Rashtchian, Davood

    2016-02-01

    In this research, organic solvent composed of hexane and methanol was used for lipid extraction from dry and wet biomass of Chlorella vulgaris. The results indicated that lipid and fatty acid extraction yield was decreased by increasing the moisture content of biomass. However, the maximum extraction efficiency was attained by applying equivolume mixture of hexane and methanol for both dry and wet biomass. Thermodynamic modeling was employed to estimate the effect of hexane/methanol ratio and moisture content on fatty acid extraction yield. Hansen solubility parameter was used in adjusting the interaction parameters of the model, which led to decrease the number of tuning parameters from 6 to 2. The results indicated that the model can accurately estimate the fatty acid recovery with average absolute deviation percentage (AAD%) of 13.90% and 15.00% for the two cases of using 6 and 2 adjustable parameters, respectively. Copyright © 2015 Elsevier Ltd. All rights reserved.

  6. N,N'-(Hexane-1,6-diylbis(4-methyl-N-(oxiran-2-ylmethylbenzenesulfonamide: Synthesis via cyclodextrin mediated N-alkylation in aqueous solution and further Prilezhaev epoxidation

    Directory of Open Access Journals (Sweden)

    Julian Fischer

    2013-12-01

    Full Text Available N-alkylation of N,N'-(hexane-1,6-diylbis(4-methylbenzenesulfonamide with allyl bromide and subsequent Prilezhaev reaction with m-chloroperbenzoic acid to give N,N'-(hexane-1,6-diylbis(4-methyl-N-(oxiran-2-ylmethylbenzenesulfonamide is described. This twofold alkylation was performed in aqueous solution, whereby α-, and randomly methylated β-cyclodextrin were used as adequate phase transfer catalysts and the cyclodextrin–guest complexes were characterized by 1H NMR and 2D NMR ROESY spectroscopy. Finally, the curing properties of the diepoxide with lysine-based α-amino-ε-caprolactam were analyzed by rheological measurements.

  7. Changes of refractive indices in ternary mixtures containing chlorobenzene + n-hexane + (n-heptane or n-octane at 298.15 K

    Directory of Open Access Journals (Sweden)

    M. IGLESIAS

    2004-06-01

    Full Text Available The refractive indices of ternary mixtures of chlorobenzene + n-hexane + (n-heptane or n-octane have been measured at 298.15 K and at atmospheric pressure over the whole composition diagram. Parameters of polynomial equations which represent the composition dependence of physical and derived properties are gathered. The experimental refractive indices and the ternary derived properties are compared with the data obtained using several predictive semi-empirical models. The use of the Soave–Redlich–Kwong (SRK and the Peng–Robinson (PR cubic equations of state with the Van der Waals one-fluid mixing rule, which incorporate different combining rules to predict refractive indices on mixing, are tested against the measured results, good agrement being obtained.

  8. Molecular exchange of n-hexane in zeolite sieves studied by diffusion-diffusion and T{sub 1}-diffusion nuclear magnetic resonance exchange spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Neudert, Oliver; Stapf, Siegfried; Mattea, Carlos, E-mail: carlos.mattea@tu-ilmenau.de [Fachgebiet Technische Physik II/Polymerphysik, Institute of Physics, Technische Universitaet Ilmenau, PO Box 100 565, 98684 Ilmenau (Germany)

    2011-03-15

    Molecular exchange properties and diffusion of n-hexane embedded in a bimodal pore structure with characteristic length scales in the order of nano and micrometres, respectively, formed by packing of zeolite particles, are studied. Two-dimensional (2D) nuclear magnetic resonance (NMR) diffusion correlation experiments together with relaxation-diffusion correlation experiments are performed at low magnetic field using a single-sided NMR scanner. The exchange time covers a range from 10{sup -3} to 10{sup -1} s. The molecular exchange properties are modulated by transport inside the zeolite particles. Different exchange regimes are observed for molecules starting from different positions inside the porous sample. The influence of the spin-lattice relaxation properties of the fluid molecules inside the zeolite particles on the signal intensity is also studied. A Monte Carlo simulation of the exchange process is performed and is used to support the analysis of the experimental data.

  9. Catalytic oxidation of n-hexane promoted by Ce1−xCuxO2 catalysts prepared by one-step polymeric precursor method

    International Nuclear Information System (INIS)

    Araújo, Vinícius D.; Lima, Maurício M. de; Cantarero, Andrés; Bernardi, Maria I.B.; Bellido, Jorge D.A.; Assaf, Elisabete M.; Balzer, Rosana; Probst, Luiz F.D.; Fajardo, Humberto V.

    2013-01-01

    Ceria-supported copper catalysts (Ce 1−x Cu x O 2 , with x (mol) = 0, 0.01, 0.03, 0.05 and 0.10) were prepared in one step through the polymeric precursor method. The textural properties of the catalysts were investigated by X-ray diffraction (XRD), Rietveld refinement, N 2 -physisorption (BET surface area), electron paramagnetic resonance (EPR), UV–visible diffuse reflectance and photoluminescence spectroscopies and temperature-programmed reduction (TPR). In a previous study ceria-supported copper catalysts were found to be efficient in the preferential oxidation of CO. In this study, we extended the catalytic application of Ce 1−x Cu x O 2 systems to n-hexane oxidation and it was verified that the catalysts were highly efficient in the proposed reaction. The best performance (up to 95% conversion) was observed for the catalysts with low copper loads (Ce 0.97 Cu 0.03 O 2 and Ce 0.99 Cu 0.01 O 2 , respectively). The physicochemical characterizations revealed that these behaviors could be attributed to the copper species present in the catalysts and the interaction between CuO and CeO 2 , which vary according to the copper content. - Highlights: • Synthesis of CuO/CeO2 catalysts by the one-step polymeric precursor method. • 95% n-hexane conversion on Ce0.97Cu0.03O2 catalyst. • Redox properties play a key role in the catalytic performance

  10. A comparative study on composition and antioxidant activities of supercritical carbon dioxide, hexane and ethanol extracts from blackberry (Rubus fruticosus) growing in Poland.

    Science.gov (United States)

    Wajs-Bonikowska, Anna; Stobiecka, Agnieszka; Bonikowski, Radosław; Krajewska, Agnieszka; Sikora, Magdalena; Kula, Józef

    2017-08-01

    Large quantities of blackberry seeds are produced as a pomace during the processing of juice and jam production; this by-product is a very interesting raw material both for oil manufacturing and as a source of bioactive compounds. In this work the composition, yield and antioxidant activity of three types of Rubus fructicosus pomace extracts isolated by liquid extraction using solvents of different polarity, as well with supercritical CO 2 fluid extraction have been compared. The highest extract yield was reported for Soxhlet extraction using ethanol as a solvent (14.2%). Supercritical carbon dioxide and hexane extracts were characterised by the highest content of phytosterols (1445 and 1583 mg 100 g -1 of extract, respectively) among which β-sitosterol was the main one, while the concentration of tocopherols, with predominant γ-isomer, was the highest for both hexane and ethanol extracts, being 2364 and 2334 mg 100 g -1 , respectively. Using a GC-MS method 95 volatiles, in which non-saturated aldehydes were predominant, were identified in the essential oil of seed pomace and in the volatile oil isolated from supercritical extract. The ethanolic extract which is characterised by the highest phenolic content (9443 mg GAE 100 g -1 ) exhibited the highest antioxidant activity (according to the ABTS •+ and DPPH • assays). All pomace extracts examined were of high quality, rich in essential omega fatty acids and with a very high content of bioactive compounds, such as phytosterols and tocopherols. The high nutritional value of extracts from berry seed pomace could justify the commercialisation of specific extracts not only as food additives but also as cosmetic components. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  11. Ameliorative Effect of Hexane Extract of Phalaris canariensis on High Fat Diet-Induced Obese and Streptozotocin-Induced Diabetic Mice

    Directory of Open Access Journals (Sweden)

    Rosa Martha Perez Gutierrez

    2014-01-01

    Full Text Available Obesity is one of the major factors to increase various disorders like diabetes. The present paper emphasizes study related to the antiobesity effect of Phalaris canariensis seeds hexane extract (Al-H in high-fat diet- (HFD- induced obese CD1 mice and in streptozotocin-induced mild diabetic (MD and severely diabetic (SD mice.AL-H was orally administered to MD and SD mice at a dose of 400 mg/kg once a day for 30 days, and a set of biochemical parameters were studied: glucose, cholesterol, triglycerides, lipid peroxidation, liver and muscle glycogen, ALP, SGOT, SGPT, glucose-6-phosphatase, glucokinase, hexokinase, SOD, CAT, GSH, GPX activities, and the effect on insulin level. HS-H significantly reduced the intake of food and water and body weight loss as well as levels of blood glucose, serum cholesterol, triglyceride, lipoprotein, oxidative stress, showed a protective hepatic effect, and increased HDL-cholesterol, serum insulin in diabetic mice. The mice fed on the high-fat diet and treated with AL-H showed inhibitory activity on the lipid metabolism decreasing body weight and weight of the liver and visceral adipose tissues and cholesterol and triglycerides in the liver. We conclude that AL-H can efficiently reduce serum glucose and inhibit insulin resistance, lipid abnormalities, and oxidative stress in MD and SD mice. Our results demonstrate an antiobesity effect reducing lipid droplet accumulation in the liver, indicating that its therapeutic properties may be due to the interaction plant components soluble in the hexane extract, with any of the multiple targets involved in obesity and diabetes pathogenesis.

  12. Ameliorative Effect of Hexane Extract of Phalaris canariensis on High Fat Diet-Induced Obese and Streptozotocin-Induced Diabetic Mice.

    Science.gov (United States)

    Perez Gutierrez, Rosa Martha; Madrigales Ahuatzi, Diana; Horcacitas, Maria Del Carmen; Garcia Baez, Efren; Cruz Victoria, Teresa; Mota-Flores, Jose Maria

    2014-01-01

    Obesity is one of the major factors to increase various disorders like diabetes. The present paper emphasizes study related to the antiobesity effect of Phalaris canariensis seeds hexane extract (Al-H) in high-fat diet- (HFD-) induced obese CD1 mice and in streptozotocin-induced mild diabetic (MD) and severely diabetic (SD) mice.AL-H was orally administered to MD and SD mice at a dose of 400 mg/kg once a day for 30 days, and a set of biochemical parameters were studied: glucose, cholesterol, triglycerides, lipid peroxidation, liver and muscle glycogen, ALP, SGOT, SGPT, glucose-6-phosphatase, glucokinase, hexokinase, SOD, CAT, GSH, GPX activities, and the effect on insulin level. HS-H significantly reduced the intake of food and water and body weight loss as well as levels of blood glucose, serum cholesterol, triglyceride, lipoprotein, oxidative stress, showed a protective hepatic effect, and increased HDL-cholesterol, serum insulin in diabetic mice. The mice fed on the high-fat diet and treated with AL-H showed inhibitory activity on the lipid metabolism decreasing body weight and weight of the liver and visceral adipose tissues and cholesterol and triglycerides in the liver. We conclude that AL-H can efficiently reduce serum glucose and inhibit insulin resistance, lipid abnormalities, and oxidative stress in MD and SD mice. Our results demonstrate an antiobesity effect reducing lipid droplet accumulation in the liver, indicating that its therapeutic properties may be due to the interaction plant components soluble in the hexane extract, with any of the multiple targets involved in obesity and diabetes pathogenesis.

  13. Pre-treatment by n-hexane extract of Phyllanthus niruri can alleviate paracetamol-induced damage of the rat liver

    Directory of Open Access Journals (Sweden)

    Md Jalaluddin Iqbal

    2007-03-01

    Full Text Available The present study aimed to obtain and evaluate remedy against viral hepatitis with Phyllanthus niruri (Bhui amla. Viral infection and toxic doses of paracetamol produce similar pattern of hepatotoxicity. Hepatotoxicity was induced by administering paracetamol (750 mg/kg body weight, single dose intraperitoneal into one group (group P of rats. Propylene glycol (vehicle was administered (2 ml into another group (group V of rats. 4 groups of P. niruri extract-pretreated (200 mg/kg body weight/day for 7 days rats were administered the same single dose of paracetamol on the 7th day. Extract of P. niruri were obtained through ethanol (E, hexane (H, dichloromethane (D and butane (B. Rat groups were V, P, E + P, H + P, D + P and B + P. Each group consisted of 6 rats and were sacrificed on the 9th day. Parameters for evaluation were biochemical (serum ALT, serum AST, serum ALP, serum bilirubin, hepatic reduced glutathione concentrations and hepatic histology. Propylene glycol (group V appeared non-toxic to the liver while significant degrees of centrilobuler hepatotoxicity was observed in group P paracetamol-treated rats. The E + P group suggested significant improvements in the serum parameters but these parameters appeared better alleviated in the H + P group. Hepatic reduced glutathione concentrations were replenished to the control level in both E + P and H + P groups. Hepatic histology supported biochemical and other observations in the P, E + P and H + P groups. Lesser degrees of alleviations were observed in the D + P and B + P groups. However, the hexane extract-pretreated group (H + P appeared to provide the most significant hepatoprotection against paracetamol induced hepatotoxicity in the rat. Titration of the dose following isolation of the active ingredient might offer complete alleviation.

  14. Pre-treatment by n-hexane extract of Phyllanthus niruri can alleviate paracetamol-induced damage of the rat liver

    Directory of Open Access Journals (Sweden)

    Md. Jalaluddin Iqbal, Fawzia Z. Dewan, S.A.R.Chowdhury, M.I.R. Mamun,

    2007-06-01

    Full Text Available The present study aimed to obtain and evaluate remedy against viral hepatitis with Phyllanthus niruri (Bhui amla. Viral infection and toxic doses of paracetamol produce similar pattern of hepatotoxicity. Hepatotoxicity was induced by administering paracetamol (750 mg/kg body weight, single dose intraperitoneal into one group (group P of rats. Propylene glycol (vehicle was administered (2 ml into another group (group V of rats. Four groups of P. niruri extract-pretreated (200 mg/kg body weight/day for 7 days rats were administered the same single dose of paracetamol on the 7th day. Extract of P. niruri were obtained through ethanol (E, hexane (H, dichloromethane (D and butane (B. Rat groups were V, P, E + P, H + P, D + P and B + P. Each group consisted of 6 rats and were sacrificed on the 9th day. Parameters for evaluation were biochemical (serum ALT, serum AST, serum ALP, serum bilirubin, hepatic reduced glutathione concentrations and hepatic histology. Propylene glycol (group V appeared non-toxic to the liver while significant degrees of centrilobuler hepatotoxicity was observed in group P paracetamol-treated rats. The E + P group suggested significant improvements in the serum parameters but these parameters appeared better alleviated in the H + P group. Hepatic reduced glutathione concentrations were replenished to the control level in both E + P and H + P groups. Hepatic histology supported biochemical and other observations in the P, E + P and H + P groups. Lesser degrees of alleviations were observed in the D + P and B + P groups. However, the hexane extract-pretreated group (H + P appeared to provide the most significant hepatoprotection against paracetamol induced hepatotoxicity in the rat. Titration of the dose following isolation of the active ingredient might offer complete alleviation.

  15. 1 - Aromatization of n-hexane and natural gasoline over ZSM-5 zeolite, 2- Wet catalytic oxidation of phenol on fixed bed of active carbon; 1 - Aromatisation de n-hexane et d'essence sur zeolithe ZSM-5, 2 - Oxydation catalytique en voie humide du phenol sur charbon actif

    Energy Technology Data Exchange (ETDEWEB)

    Suwanprasop, S.

    2005-04-15

    I - The production of aromatic hydrocarbons from n-hexane and natural gasoline over Pd loaded ZSM-5 zeolite in a tubular reactor was achieved under the suitable conditions at 400 deg. C, and 0.4 ml/min reactant feeding rate, employing ZSM-5 (0.5% Pd content) as a catalyst. Under these conditions, n-hexane and natural gasoline conversions were found to be 99.7% and 94.3%, respectively (with respective aromatic selectivity of 92.3% and 92.6%). II - Wet catalytic air oxidation of phenol over a commercial active carbon was studied in a three phase fixed bed reactor under mild temperature and oxygen partial pressure. Exit phenol concentration, COD, and intermediates were analysed. Oxidation of phenol was significantly improved when increasing operating temperature, oxygen partial pressure, and liquid space time, while up or down flow modes had only marginal effect. A complete model involving intrinsic kinetics and all mass transfer limitations gave convenient reactor simulation. (author)

  16. High-temperature catalytic reforming of n-hexane over supported and core-shell Pt nanoparticle catalysts: role of oxide-metal interface and thermal stability.

    Science.gov (United States)

    An, Kwangjin; Zhang, Qiao; Alayoglu, Selim; Musselwhite, Nathan; Shin, Jae-Youn; Somorjai, Gabor A

    2014-08-13

    Designing catalysts with high thermal stability and resistance to deactivation while simultaneously maintaining their catalytic activity and selectivity is of key importance in high-temperature reforming reactions. We prepared Pt nanoparticle catalysts supported on either mesoporous SiO2 or TiO2. Sandwich-type Pt core@shell catalysts (SiO2@Pt@SiO2 and SiO2@Pt@TiO2) were also synthesized from Pt nanoparticles deposited on SiO2 spheres, which were encapsulated by either mesoporous SiO2 or TiO2 shells. n-Hexane reforming was carried out over these four catalysts at 240-500 °C with a hexane/H2 ratio of 1:5 to investigate thermal stability and the role of the support. For the production of high-octane gasoline, branched C6 isomers are more highly desired than other cyclic, aromatic, and cracking products. Over Pt/TiO2 catalyst, production of 2-methylpentane and 3-methylpentane via isomerization was increased selectively up to 420 °C by charge transfer at Pt-TiO2 interfaces, as compared to Pt/SiO2. When thermal stability was compared between supported catalysts and sandwich-type core@shell catalysts, the Pt/SiO2 catalyst suffered sintering above 400 °C, whereas the SiO2@Pt@SiO2 catalyst preserved the Pt nanoparticle size and shape up to 500 °C. The SiO2@Pt@TiO2 catalyst led to Pt nanoparticle sintering due to incomplete protection of the TiO2 shells during the reaction at 500 °C. Interestingly, over the Pt/TiO2 catalyst, the average size of Pt nanoparticles was maintained even after 500 °C without sintering. In situ ambient pressure X-ray photoelectron spectroscopy demonstrated that the Pt/TiO2 catalyst did not exhibit TiO2 overgrowth on the Pt surface or deactivation by Pt sintering up to 600 °C. The extraordinarily high stability of the Pt/TiO2 catalyst promoted high reaction rates (2.0 μmol · g(-1) · s(-1)), which was 8 times greater than other catalysts and high isomer selectivity (53.0% of C6 isomers at 440 °C). By the strong metal-support interaction

  17. Anti-cryptococcal activity of ethanol crude extract and hexane fraction from Ocimum basilicum var. Maria bonita: mechanisms of action and synergism with amphotericin B and Ocimum basilicum essential oil.

    Science.gov (United States)

    Cardoso, Nathalia N R; Alviano, Celuta S; Blank, Arie F; Arrigoni-Blank, Maria de Fátima; Romanos, Maria Teresa V; Cunha, Marcel M L; da Silva, Antonio Jorge R; Alviano, Daniela S

    2017-12-01

    Ocimum basilicum L. (Lamiaceae) has been used in folk medicine to treat headaches, kidney disorders, and intestinal worms. This study evaluates the anti-cryptococcal activity of ethanol crude extract and hexane fraction obtained from O. basilicum var. Maria Bonita leaves. The MIC values for Cryptococcus sp. were obtained according to Clinical and Laboratory Standards Institute in a range of 0.3-2500 μg/mL. The checkerboard assay evaluated the association of the substances tested (in a range of 0.099-2500 μg/mL) with amphotericin B and O. basilicum essential oil for 48 h. The ethanol extract, hexane fraction and associations in a range of 0.3-2500 μg/mL were tested for pigmentation inhibition after 7 days of treatment. The inhibition of ergosterol synthesis and reduction of capsule size were evaluated after the treatment with ethanol extract (312 μg/mL), hexane fraction (78 μg/mL) and the combinations of essential oil + ethanol extract (78 μg/mL + 19.5 μg/mL, respectively) and essential oil + hexane fraction (39.36 μg/mL + 10 μg/mL, respectively) for 24 and 48 h, respectively. The hexane fraction presented better results than the ethanol extract, with a low MIC (156 μg/mL against C. neoformans T 444 and 312 μg/mL against C. neoformans H99 serotype A and C. gattii WM779 serotype C). The combination of the ethanol extract and hexane fraction with amphotericin B and essential oil enhanced their antifungal activity, reducing the concentration of each substance needed to kill 100% of the inoculum. The substances tested were able to reduce the pigmentation, capsule size and ergosterol synthesis, which suggest they have important mechanisms of action. These results provide further support for the use of ethanol extracts of O. basilicum as a potential source of antifungal agents.

  18. n-hexane, why is a separate guideline being developed and why is it being considered for oil and gas impacted sites?

    Energy Technology Data Exchange (ETDEWEB)

    Knafla, A.L.; Carey, J.; Ranganathan, S. [Equilibrium Environmental Inc., Calgary, AB (Canada)

    2008-07-01

    Benzene, toluene, ethylbenzene, and xylenes (BTEX) compounds are among the volatile organic compounds (VOCs) found in petroleum derivatives such as gasoline and are notorious due to the contamination of soil and groundwater with these compounds. This presentation provided an overview of the F1 fraction and discussed F1 fraction toxicity. It discussed what drives the risk and why one of these compounds is being considered for removal from the mixture (such as BTEX). The focus of the presentation was on the inhalation route of exposure. Environmental data for F1 was presented with particular reference to unweathered product in terms of the mass percentage of F1 aliphatic vapours in breathing zone of gasoline station workers; and for weathered product in terms of soil vapour concentrations; and in upstream oil and gas condensate sites. Toxicity data for F1 aromatics and an exploration of commercial n-hexane (HX) toxicity were also presented. It was concluded that HX was a significant component of the F1 fraction; HX had a unique toxicity due to its mechanism of action; toxicity occurred in the presence of other F1 hydrocarbons; HX should not be used as a surrogate for F1 and should be separated and included with BTEX; HX could be detected as part of a F1; and some toxicity limit should be selected to represent HX. tabs., figs.

  19. Beneficial Effects of Ethanolic and Hexanic Rice Bran Extract on Mitochondrial Function in PC12 Cells and the Search for Bioactive Components

    Directory of Open Access Journals (Sweden)

    Stephanie Hagl

    2015-09-01

    Full Text Available Mitochondria are involved in the aging processes that ultimately lead to neurodegeneration and the development of Alzheimer’s disease (AD. A healthy lifestyle, including a diet rich in antioxidants and polyphenols, represents one strategy to protect the brain and to prevent neurodegeneration. We recently reported that a stabilized hexanic rice bran extract (RBE rich in vitamin E and polyphenols (but unsuitable for human consumption has beneficial effects on mitochondrial function in vitro and in vivo (doi:10.1016/j.phrs.2013.06.008, 10.3233/JAD-132084. To enable the use of RBE as food additive, a stabilized ethanolic extract has been produced. Here, we compare the vitamin E profiles of both extracts and their effects on mitochondrial function (ATP concentrations, mitochondrial membrane potential, mitochondrial respiration and mitochondrial biogenesis in PC12 cells. We found that vitamin E contents and the effects of both RBE on mitochondrial function were similar. Furthermore, we aimed to identify components responsible for the mitochondria-protective effects of RBE, but could not achieve a conclusive result. α-Tocotrienol and possibly also γ-tocotrienol, α-tocopherol and δ-tocopherol might be involved, but hitherto unknown components of RBE or a synergistic effect of various components might also play a role in mediating RBE’s beneficial effects on mitochondrial function.

  20. The long chain of the n-hexane fraction of water hyacinth (eichhornia crassipes): extrction, estimation, GC-MS analysis and antimicrobial activity

    International Nuclear Information System (INIS)

    Hussain, Z.; Khan, K.M.

    2015-01-01

    Oily fraction was extracted from the water hyacinth (Eichhornia crassipes) using n-hexane by both cold and hot extraction in 5.5 ± 0.05% and 9.30 ± 0.05%, respectively, however, no difference was found in the nature of the compounds extracted by the two processes. The analysis of this oil was carried out using GC-FID and GC-MS in separate experiments and the nature of the compounds was investigated by library matching of the spectra obtained through GC-MS. This extract was found to contain 33.267% of the nonadecan-4-ol and 20.51% of a long chain ketone in addition to various quantities of the long chain nitrogenous compounds. The antibacterial activity of the extract was investigated against eight pathogenic bacteria and fungus Candida albican using disc diffusion method. The extract was found to be highly active against all tested bacterial strains except S. typhi. For most of the strains the activity of the extract was near the reference. Ciprofloxacin, clotrimazole and erythromycin were used as reference antibiotics. (author)

  1. Development of a Henry's constant correlation and solubility measurements of n-pentane, i-pentane, cyclopentane, n-hexane, and toluene in water

    International Nuclear Information System (INIS)

    Chapoy, Antonin; Haghighi, Hooman; Tohidi, Bahman

    2008-01-01

    In this communication, we report new experimental data on n-pentane, i-pentane, cyclopentane, n-hexane, and toluene solubility in water at low temperature (below 298.15 K) and atmospheric pressure conditions. The new experimental data together with those reported in the literature have been used in developing a new equation for Henry's constants of normal alkanes (methane to decane), BETEX compounds, and acid gases in aqueous phase over a wide range of temperature (typically from 273.15 K to 373.15 K). The new equation is based on a thermodynamic model, which uses the Peng-Robinson equation of state combined with the classical quadratic mixing rules for modelling non-aqueous phases, while the NRTL model is used to calculate the water activity. The predictions of the developed thermodynamic model are compared to the experimental data and the results of a thermodynamic approach, which uses the Valderrama modification of the Patel-Teja equation of state and non-density dependent mixing rules for modelling all fluid phases. Good agreement is observed between the experimental data and the model predictions

  2. Vapor phase nucleation of the short-chain n-alkanes (n-pentane, n-hexane and n-heptane): Experiments and Monte Carlo simulations

    Science.gov (United States)

    Ogunronbi, Kehinde E.; Sepehri, Aliasghar; Chen, Bin; Wyslouzil, Barbara E.

    2018-04-01

    We measured the nucleation rates of n-pentane through n-heptane in a supersonic nozzle at temperatures ranging from ca. 109 K to 168 K. For n-pentane and n-hexane, these are the first nucleation rate measurements that have been made, and the trends in the current data agree well with those in the earlier work of Ghosh et al. [J. Chem. Phys. 132, 024307 (2010)] for longer chain alkanes. Complementary Monte Carlo simulations, using the transferable potentials for phase equilibria-united atom potentials, suggest that despite the high degree of supercooling, the critical clusters remain liquid like under experimental conditions for n-pentane through n-heptane, but adopt more ordered structures for n-octane and n-nonane. For all three alkanes, the experimental and simulated nucleation rates are offset by ˜3 orders of magnitude when plotted as a function of ln S/(Tc/T - 1)1.5. Explicitly accounting for the surface tension difference between the real and model substances, or alternatively using the Hale [Phys. Rev. A 33, 4156 (1986); Metall. Mater. Trans. A 23, 1863 (1992)] scaling parameter, Ω, consistent with the model potential, increases the offset to ˜6 orders of magnitude.

  3. A green approach towards adoption of chemical reaction model on 2,5-dimethyl-2,5-di-(tert-butylperoxy)hexane decomposition by differential isoconversional kinetic analysis

    Energy Technology Data Exchange (ETDEWEB)

    Das, Mitali; Shu, Chi-Min, E-mail: shucm@yuntech.edu.tw

    2016-01-15

    Highlights: • Thermally degraded DBPH products are identified. • An appropriate mathematical model was selected for decomposition study. • Differential isoconversional analysis was performed to obtain kinetic parameters. • Simulation on thermal analysis model was conducted for the best storage conditions. - Abstract: This study investigated the thermal degradation products of 2,5-dimethyl-2,5-di-(tert-butylperoxy) hexane (DBPH), by TG/GC/MS to identify runaway reaction and thermal safety parameters. It also included the determination of time to maximum rate under adiabatic conditions (TMR{sub ad}) and self-accelerating decomposition temperature obtained through Advanced Kinetics and Technology Solutions. The apparent activation energy (E{sub a}) was calculated from differential isoconversional kinetic analysis method using differential scanning calorimetry experiments. The E{sub a} value obtained by Friedman analysis is in the range of 118.0–149.0 kJ mol{sup −1}. The TMR{sub ad} was 24.0 h with an apparent onset temperature of 82.4 °C. This study has also established an efficient benchmark for a thermal hazard assessment of DBPH that can be applied to assure safer storage conditions.

  4. Study of molecular interactions in binary liquid mixtures of 1-octanol with n-hexane, n-octane, and n-decane using volumetric, viscometric, and acoustic properties

    International Nuclear Information System (INIS)

    Dubey, Gyan P.; Sharma, Monika

    2008-01-01

    Experimental values of densities (ρ) and speeds of sound (u) at T = (298.15, 303.15, and 308.15) K while the viscosities (η) at T = 298.15 K in the binary mixtures of 1-octanol with n-hexane, n-octane, and n-decane are presented over the entire composition range of the binary mixtures. Using these data, excess molar volumes (V m E ), viscosity deviation (Δη), deviation in speeds of sound (Δu), deviation in isentropic compressibility (Δκ s ), excess free volume (V f E ), and excess Gibbs free energy of activation of viscous flow (ΔG* E ) are calculated and presented graphically. All the computed quantities are fitted to a polynomial equation. The values of V m E have been analyzed using Prigogine-Flory-Patterson (PFP) theory. Furthermore, the theoretical values of speed of sound (u) and isentropic compressibility (κ s ) have also been estimated using the Prigogine-Flory-Patterson (PFP) theory with the van der Waals (vdW) potential energy model and the results have been compared with experimental values. The experimental and calculated quantities are used to study the nature of mixing behaviour between the mixture components

  5. ANTIBACTERIAL AND ANTIFUNGAL EFFECT OF ETHANOL EXTRACTS, HEXANE AND METHANOLIC FROM THE LEAVES OF Kalanchoe pinnata (Lam. PERS (Malva corama AGAINST MULTI-DRUG RESISTANT STRAINS

    Directory of Open Access Journals (Sweden)

    Paloma de Souza Santana

    2016-03-01

    Full Text Available The infections caused by bacteria and fungi, as well as the subsequent resistance of these microorganisms continue with high incidencesthus studies of medicinal plants and their combination with conventional therapy, are becoming essential. This study examined the antibacterial, antifungal and modifier of resistance to antibiotics and antifungal extracts of ethanol, hexane and methanol from the leaves of Kalanchoe pinnata, used in folk medicine. The phytochemical was performed qualitatively by visual observation of color changes and formation of precipitates after addition of specific reagents, such as ferric chloride (Fecl310% sodium hydroxide (NaOH10%, hydrochloric acid (HCl 1%, acid  acetic acid 5%, ammonium hydroxide (NH4OH 10%, chloroform and  reagent Draggendorff 10%. The analysis for antimicrobial activity was through the microdilution test for determination of minimum inhibitory concentration (MIC and modifying the action of antibiotics (gentamicin and amikacin and antifungals (ketoconazole and fluconazole in association with the extracts. The phytochemicals assays indicated the presence of secondary metabolites such as flavonoids, alkaloids and flabobênicos tannins. In assessing the MIC results were obtained <1024μg/ mL for Candida albicans and Candida krusei. There was synergism between extracts of Kalanchoe pinnata leaves with aminoglycosides and antifungal, reducing the concentration of CIM of multidrug-resistant strains. Our results demonstrate that the extracts of Kalanchoe pinnata have bioactive constituents with antimicrobial activity in vitro. Keywords: Kalcinchoe pinnata, Microorganisms, Synergistic effect, Antifungal, Antibacterial.

  6. The liquid–liquid coexistence curves of {x dimethyl adipate + (1 − x) n-hexane} and {x dimethyl adipate + (1 − x) n-heptane} in the critical region

    International Nuclear Information System (INIS)

    Chen Zhiyun; Cai Li; Huang Meijun; Yin Tianxiang; An Xueqin; Shen Weiguo

    2012-01-01

    Highlights: ► Coexistence curves of (dimethyl adipate + n-hexane) (+n-heptane) were measured. ► The critical exponent β are consistent with the 3D-Ising value. ► The asymmetry of the coexistence curves were discussed by complete scaling theory. - Abstract: The liquid–liquid coexistence curves for (dimethyl adipate + n-hexane), (dimethyl adipate + n-heptane) have been measured, from which the critical amplitudes and the critical exponents are deduced. The critical exponent β corresponding to the coexistence curves are consistent with the 3D-Ising value. The experimental results have also been analyzed to determine the critical amplitudes of Wegner-correction terms when β and Δ are fixed at their theoretical values, and to examine the asymmetry of the diameters for the coexistence curves.

  7. 高压下甲烷在乙醇-正己烷混合溶剂中的溶解度测定与研究%Solubility of Methane in the Mixture of Ethanol+Hexane at High Pressures

    Institute of Scientific and Technical Information of China (English)

    华超; 马沛生; 夏淑倩; 白鹏

    2005-01-01

    Solubility data were first presented for methane in the mixture of ethanol-hexane at temperatures from 291.15 K to 318.15K and pressures up to 12.00MPa. The experimental data were correlated by PR and PRSV equations of state with rms errors of about 0.051. The A-K and Y-W-A-K models were both used to estimate liquid molar volume under high pressure. The results were satisfactory.

  8. Protective action of a hexane crude extract of Pterodon emarginatus fruits against oxidative and nitrosative stress induced by acute exercise in rats

    Directory of Open Access Journals (Sweden)

    Alfredo Patrícia P

    2005-08-01

    Full Text Available Abstract Background The aim of the present work was to evaluate the effect of a hexane crude extract (HCE of Pterodon emarginatus on the oxidative and nitrosative stress induced in skeletal muscle, liver and brain of acutely exercised rats. Methods Adult male rats were subjected to acute exercise by standardized contractions of the tibialis anterior (TA muscle (100 Hz, 15 min and treated orally with the HCE (once or three times with a fixed dose of 498 mg/kg, before and after acute exercise. Serum creatine kinase activity was determined by a kinetic method and macrophage infiltration by histological analyses of TA muscle. Lipid peroxidation was measured as malondialdehyde (MDA levels. Nitric oxide production was evaluated by measuring nitrite formation, using Griess reagent, and nitrotyrosine was assessed by western blotting. Results Serum creatine kinase activities in the controls (111 U/L increased 1 h after acute exercise (443 U/L. Acute exercise also increased the infiltration of macrophages into TA muscle; lipid peroxidation levels in TA muscle (967%, liver (55.5% and brain (108.9%, as well as the nitrite levels by 90.5%, 30.7% and 60%, respectively. The pattern of nitrotyrosine formation was also affected by acute exercise. Treatment with HCE decreased macrophage infiltration, lipid peroxidation, nitrite production and nitrotyrosine levels to control values. Conclusion Acute exercise induced by functional electrical stimulation in rats resulted in increase in lipid peroxidation, nitrite and nitrotyrosine levels in brain, liver and skeletal muscle. The exercise protocol, that involved eccentric muscle contraction, also caused some muscle trauma, associated with over-exertion, leading to inflammation. The extract of P. emarginatus abolished most of these oxidative processes, thus confirming the high antioxidant activity of this oil which infusions are used in folk medicine against inflammatory processes.

  9. Protective effect of hexane and ethanol extract of piper longum L. On gentamicin-induced hair cell loss in neonatal cultures.

    Science.gov (United States)

    Yadav, Mukesh Kumar; Choi, June; Song, Jae-Jun

    2014-03-01

    Gentamicin (GM) is a commonly used aminoglycoside antibiotic that generates free oxygen radicals within the inner ear, which can cause vestibulo-cochlear toxicity and permanent damage to the sensory hair cells and neurons. Piper longum L. (PL) is a well-known spice and traditional medicine in Asia and Pacific islands, which has been reported to exhibit a wide spectrum of activity, including antioxidant activity. In this study, we evaluated the effect of hexane:ethanol (2:8) PL extract (subfraction of PL [SPL] extract) on GM-induced hair cell loss in basal, middle and apical regions in a neonatal cochlea cultures. The protective effects of SPL extract were measured by phalloidin staining of cultures from postnatal day 2-3 mice with GM-induced hair cell loss. The anti-apoptosis activity of SPL extract was measured using double labeling by terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) and myosin-7a staining. The radical-scavenging activity of SPL extract was assessed using the 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay. SPL extract at a concentration of 1 µg/mL significantly inhibited GM-induced hair cell loss at basal and middle region of cochlea, while 5 µg/mL was effective against apical region hair cell loss. The protective effect of SPL extract was concentration dependent and hair cells retained their stereocilia in explants treated with SPL extract prior to treatment with 0.3 mM GM. SPL extract decreased GM-induced apoptosis of hair cells as assessed by TUNEL staining. The outer hair and inner hair counts were not decreased in SPL extract treated groups in compare to GM treated explants. Additionally, SPL extract showed concentration dependent radical scavenging activity in a DPPH assay. An anti-apoptosis effect and potent radical scavenger activity of SPL extract protects from GM-induced hair cell loss at basal, middle and apical regions in neonatal cochlea cultures.

  10. Tensiometry and dilational rheology of mixed β-lactoglobulin/ionic surfactant adsorption layers at water/air and water/hexane interfaces.

    Science.gov (United States)

    Dan, Abhijit; Gochev, Georgi; Miller, Reinhard

    2015-07-01

    Oscillating drop tensiometry was applied to study adsorbed interfacial layers at water/air and water/hexane interfaces formed from mixed solutions of β-lactoglobulin (BLG, 1 μM in 10 mM buffer, pH 7 - negative net charge) and the anionic surfactant SDS or the cationic DoTAB. The interfacial pressure Π and the dilational viscoelasticity modulus |E| of the mixed layers were measured for mixtures of varying surfactant concentrations. The double capillary technique was employed which enables exchange of the protein solution in the drop bulk by surfactant solution (sequential adsorption) or by pure buffer (washing out). The first protocol allows probing the influence of the surfactant on a pre-adsorbed protein layer thus studying the protein/surfactant interactions at the interface. The second protocol gives access to the residual values of Π and |E| measured after the washing out procedure thus bringing information about the process of protein desorption. The DoTAB/BLG complexes exhibit higher surface activity and higher resistance to desorption in comparison with those for the SDS/BLG complexes due to hydrophobization via electrostatic binding of surfactant molecules. The neutral DoTAB/BLG complexes achieve maximum elastic response of the mixed layer. Mixed BLG/surfactant layers at the water/oil interface are found to reach higher surface pressure and lower maximum dilational elasticity than those at the water/air surface. The sequential adsorption mode experiments and the desorption study reveal that binding of DoTAB to pre-adsorbed BLG globules is somehow restricted at the water/air surface in comparison with the case of complex formation in the solution bulk and subsequently adsorbed at the water/air surface. Maximum elasticity is achieved with washed out layers obtained after simultaneous adsorption, i.e. isolation of the most surface active DoTAB/BLG complex. These specific effects are much less pronounced at the W/H interface. Copyright © 2015 Elsevier Inc

  11. Effect of physical exertion on the biological monitoring of exposure to various solvents following exposure by inhalation in human volunteers: II. n-Hexane.

    Science.gov (United States)

    Tardif, Robert; Nadeau, Véronique; Truchon, Ginette; Brochu, Martin

    2007-07-01

    This study evaluated the impact of physical exertion on two n-hexane (HEX) exposure indicators in human volunteers exposed under controlled conditions in an inhalation chamber. A group of four volunteers (two women, two men) were exposed to HEX (50 ppm; 176 mg/m(3)) according to several scenarios involving several periods when volunteers performed either aerobic (AERO), muscular (MUSC), or both AERO/MUSC types of exercise. The target intensities for 30-min exercise periods separated by 15-min rest periods were the following: REST, 50W AERO [time-weighted average intensity including resting period (TWAI): 38W], 50W AERO/MUSC (TWAI: 34W), 100W AERO/MUSC (TWAI: 63W), and 100W AERO (TWAI: 71W) for 7 hr (two 3-hr exposure periods separated by 1 hr without exposure) and 50W MUSC for 3 hr (TWAI: 31W). Alveolar air and urine samples were collected at different time intervals before, during, and after exposure to measure unchanged HEX in expired air (HEX-A) and urinary 2,5-hexanedione (2,5-HD). HEX-A levels during exposures involving AERO activities (TWAI: 38W and 71W) were significantly enhanced (approximately +14%) compared with exposure at rest. MUSC or AERO/MUSC exercises were also associated with higher HEX-A levels but only at some sampling times. In contrast, end-of-exposure (7 hr) urinary 2,5-HD (mean +/- SD) was not modified by physical exertion: 4.14 +/- 1.51 micromol/L (REST), 4.02 +/- 1.52 micromol/L (TWAI 34W), 4.25 +/- 1.53 micromol/L (TWAI 38W), 3.73 +/- 2.09 micromol/L (TWAI 63W), 3.6 +/- 1.34 micromol/L (TWAI 71W) even though a downward trend was observed. Overall, this study showed that HEX kinetics is practically insensitive to moderate variations in workload intensity; only HEX-A levels increased slightly, and urinary 2,5-HD levels remained unchanged despite the fact that all types of physical exercise increased the pulmonary ventilation rate.

  12. The n-hexane and chloroform fractions of Piper betle L. trigger different arms of immune responses in BALB/c mice and exhibit antifilarial activity against human lymphatic filarid Brugia malayi.

    Science.gov (United States)

    Singh, Meghna; Shakya, Shilpy; Soni, Vishal Kumar; Dangi, Anil; Kumar, Nikhil; Bhattacharya, Shailja-Misra

    2009-06-01

    Modulation of immune functions by using herbal plants and their products has become fundamental regime of therapeutic approach. Piper betle Linn. (Piperaceae) is a widely distributed plant in the tropical and subtropical regions of the world and has been attributed as traditional herbal remedy for many diseases. We have recently reported the antifilarial and antileishmanial efficacy in the leaf extract of Bangla Mahoba landrace of P. betle which is a female plant. The present report describes the in vivo immunomodulatory efficacy of the crude methanolic extract and its n-hexane, chloroform, n-butanol fractions of the female plant at various dose levels ranging between 0.3 and 500 mg/kg in BALB/c. Attempts were also made to observe antifilarial activity of the active extracts and correlate it with the antigen specific immune responses in another rodent Mastomys coucha infected with human lymphatic filarial parasite Brugia malayi. The crude methanol extract and n-hexane fraction were found to potentiate significant (p<0.001) enhancement of both humoral (plaque forming cells, hemagglutination titre) as well as cell-mediated (lymphoproliferation, macrophage activation, delayed type hypersensitivity) immune responses in mice. The flow cytometric analysis of splenocytes of treated mice indicated enhanced population of T-cells (CD4(+), CD8(+)) and B-cells (CD19(+)). The n-hexane fraction (3 mg/kg) was found to induce biased type 2 cytokine response as revealed by increased IL-4(+) and decreased IFN-gamma(+) T-cell population while the chloroform fraction (10 mg/kg) produced a predominant type 1 cytokines. Crude methanolic extract (100 mg/kg) demonstrated a mixed type 1 and type 2 cytokine responses thus suggesting a remarkable immunomodulatory property in this plant. The induction of differential T-helper cell immune response appears ideal to overcome immunosuppression as observed in case of lymphatic, filarial Brugia malayi infection which may also be extended to other

  13. Amélioration des méthodes de dosage de traces d’hexane résiduel dans les huiles végétales raffinées

    Directory of Open Access Journals (Sweden)

    Lacoste Florence

    2001-03-01

    Full Text Available Afin d’améliorer la sensibilité et la répétabilité du dosage des traces d’hexane résiduel dans les corps gras pour des teneurs de l’ordre du mg/kg, une optimisation de la méthode décrite dans la norme Afnor NF T 60-257 a été entreprise en chromatographie en phase gazeuse. L’utilisation d’une colonne de type wide-bore à film épais, en couplage avec un appareil automatique d’espace de tête statique ou même en pratiquant l’analyse avec injection manuelle, permet de quantifier 0,25 mg/kg d’hexane technique. La linéarité de la réponse est très bonne dans le domaine de teneurs considéré, de 1 à 10 mg/kg. Les taux de récupération sont satisfaisants puisqu’ils sont compris entre 93 et 107 % pour les échantillons de concentration en hexane technique comprise entre 0,25 et 2 mg/kg. Les résultats témoignent également de la bonne répétabilité de cette méthode ; en effet, pour une concentration de 1 mg/kg, le coefficient de variation est d’environ 3 %.

  14. (1R,2R,3R,4R,5S-2,3-Bis[(2S′-2-acetoxy-2-phenylacetoxy]-4-azido-1-[(2,4-dinitrophenylhydrazonomethyl]bicyclo[3.1.0]hexane

    Directory of Open Access Journals (Sweden)

    Robert McDonald

    2008-02-01

    Full Text Available In the title compound, C38H29N7O12, the five-membered ring adopts an envelope conformation in which the `flap' is cis to the cyclopropane group. This conformation is similar to those of other bicyclo[3.1.0]hexane analogues for which crystal structures have been reported. The absolute configuration of the stereogenic centers on the cyclopentane ring, as determined by comparison with the known configurations of the stereogenic centers in the (2S-2-acetoxy-2-phenylacetoxy groups, is 1(R, 2(R, 3(R, 4(R and 5(S. An intramolecular N—H...O hydrogen bond is present.

  15. One-Pot Synthesis of Dialkyl Hexane-1,6-Dicarbamate from 1,6-Hexanediamine, Urea, and Alcohol over Zinc-Incorporated Berlinite (ZnAlPO4 Catalyst

    Directory of Open Access Journals (Sweden)

    Da-Lei Sun

    2016-02-01

    Full Text Available Dialkyl hexane-1,6-dicarbamate was synthesized, for the first time, by a one-pot reaction of 1,6-hexanediamine (HDA, urea, and alcohols, including methanol, ethanol, propanol, and butanol, in a self-designed batch reactor, using zinc-incorporated berlinite (ZnAlPO4 as a catalyst. The yield of dibutyl hexane-1,6-dicarbamate (2 was systematically investigated as a function of Zn/Al molar ratio, reaction temperature, reaction time, catalyst usage and urea/HDA/butanol molar ratio. Based on these studies, the optimized reaction conditions were as follows: molar ratio urea/HDA/butanol = 2.6:1:8.6, catalyst usage = 3.0 g, reaction temperature = 493 K, reaction time = 6 h and reaction pressure = 1.2 MPa; a yield of 2 of 89.7% was achieved over the ZnAlPO4 (molar ratio Zn/Al = 0.04 catalyst. The catalysts were characterized by X-ray photoelectric spectroscopy (XPS and scanning electron microscope (SEM. Additionally, based on these experimental results, it was also proposed that the catalysis recycle of the one-pot synthesis of 2 from urea, HDA, and butanol over the ZnAlPO4 catalyst.

  16. Crystal structure of mer-tris{2,6-difluoro-3-[5-(2-fluorophenylpyridin-2-yl-κN]pyridin-4-yl-κC4}iridium(III dichloromethane hemisolvate n-hexane hemisolvate

    Directory of Open Access Journals (Sweden)

    Youngjin Kang

    2017-12-01

    Full Text Available The asymmetric unit of the title compound, [Ir(C17H11F2N23]·0.5CH3(CH24CH3·0.5CH2Cl2, comprises one IrIII atom, three 2,6-difluoro-3-[5-(2-fluorophenylpyridin-2-yl]pyridin-4-yl ligands and half each of an n-hexane and a dichloromethane solvent molecule located about crystallographic inversion centres. The IrIII atom displays a distorted octahedral coordination geometry, having three C,N-chelating 2,6-difluoro-3-[5-(2-fluorophenylpyridin-2-yl]pyridin-4-yl ligands arranged in a meridional manner. The IrIII ion lies almost in the equatorial plane [deviation = 0.0069 (15 Å]. The average distance [2.041 (3 Å] of Ir—C bonds is slightly shorter than that [2.076 (3 Å] of Ir—N bonds. A variety of intra- and intermolecular C—H...F and C—H...π hydrogen bonds, as well as intermolecular C—F...π interactions, contribute to the stabilization of the molecular and crystal structures, and result in the formation of a two-dimensional network parallel to the ab plane. No interactions between n-hexane solvent molecules and the other components in the title compound are observed.

  17. Crystal structure of the formal 20 electron zirconocene pentafulvene complex Cp2Zr(η5,η1-adamantylidenepentafulvene:toluene:n-hexane = 1:0.125:0.125

    Directory of Open Access Journals (Sweden)

    Malte Fischer

    2017-12-01

    Full Text Available The crystal structure of a solvated zirconocene pentafulvene complex with a bulky adamantylidene substitution pattern, namely (η5,η1-adamantylidenepentafulvenebis(η5-cyclopentadienylzirconium(IV–toluene–n-hexane (8/1/1, [Zr(C15H18(C5H52]·0.125C7H8·0.125C6H14, is reported. Reducing zirconocene dichloride with magnesium results in the formation of a low-valent zirconocene reagent that reacts readily with adamantylidenepentafulvene to give the aforementioned complex. Single crystal X-ray diffraction proves the dianion-like η5:η1 binding mode of the fulvene ligand to the central ZrIV atom. The asymmetric unit contains four independent molecules of [η5:η1-adamantylidenepentafulvene]bis[(η5-cyclopentadienyl]zirconium(IV, together with half a molecule of toluene disordered with half a molecule of n-hexane (the solvent molecules have no direct influence on the complex. In each of the four complex molecules, the central ZrIV atom has a distorted tetrahedral coordination environment. The measured crystal consisted of two domains with a refined ratio of 0.77:0.23.

  18. Zeolites adsorbent study containing zinc for remove gasoline in 2-propanothiol/hexane mixture; Estudo de adsorventes zeoliticos contendo zinco, para remocao de enxofre na mistura 2-propanotiol/hexano

    Energy Technology Data Exchange (ETDEWEB)

    Clericuzi, G.Z.; Barbosa, C. Maria B.M. [Pernambuco Univ., Recife, PE (Brazil). Dept. de Engenharia Quimica]. E-mail: clericuzi@bol.com.br; celmy@ufpe.br; Souza-Aguiar, E.F. [PETROBRAS, Rio de Janeiro, RJ (Brazil). Centro de Pesquisas]. E-mail: falabella@cenpes.petrobras.com.br; Medina, N. [Administracion Nacional de Combustibles Alcohol Y Portland (ANCAP) (Uruguay)]. E-mail: nildamedina@hotmail.com

    2003-07-01

    The control of emission sulfur of gasoline has been increasing all over the world. An important process for that reduction is certainly the hydrotreatment of the gasoline of FCC. Aiming to get lower the level of emission of the control taxes of the sulfur, an alternative process is an adsorption, using zeolites, for having less severe and more economical of operation conditions, detaching the synthetic zeolites. In the present work were used two adsorbents zeolites containing respectively 0,5% of Zinc/NaY (Zn1) and 5% of Zinc/NaY (Zn2), prepared after all was molded pellets by ionic change and using graphite to for in all, it was obtained pellets with 3 mm. The kinetic study was accomplished with a mixture of 2-propanothiol and hexane. Begging of an initial concentration of 200 mg L{sup -1} of sulfur, the results were obtained by analyses of the concentration in a chromatograph type CG and evidenced that the adsorption is more effective for Zn2 adsorbent, because of the competition among substances, solvents, hexane, and solute of 2-propanothiol, due their the molecular structures and the inferior zinc tenor than the other adsorbent. (author)

  19. Multidimensional analysis of cannabis volatile constituents: identification of 5,5-dimethyl-1-vinylbicyclo[2.1.1]hexane as a volatile marker of hashish, the resin of Cannabis sativa L.

    Science.gov (United States)

    Marchini, Marie; Charvoz, Céline; Dujourdy, Laurence; Baldovini, Nicolas; Filippi, Jean-Jacques

    2014-11-28

    The volatile constituents of drug samples derived from Cannabis sativa L. were investigated by means of headspace solid phase microextraction (HS-SPME) and gas chromatography techniques (GC-MS, GC×GC-MS). Samples of cannabis herb and hashish showed clear differences in their volatile chemical profiles, mostly resulting from photo-oxidation processes occurring during the transformation of fresh cannabis herb into hashish. Most unexpectedly, we could demonstrate hashish samples as containing remarkable amounts of a rare and unusual monoterpene - 5,5-dimethyl-1-vinylbicyclo[2.1.1]hexane - among the volatile compounds detected in their headspaces. We gave evidence for the formation of this compound from the light induced rearrangement of β-myrcene during the manufacture of hashish. In view of its high abundance among volatile constituents of cannabis resin and its scarce occurrence in other natural volatile extracts, we propose to rename this specific monoterpene hashishene. Copyright © 2014 Elsevier B.V. All rights reserved.

  20. Determination of tributyltin (TBT) in marine sediment using pressurised liquid extraction-gas chromatography-isotope dilution mass spectrometry (PLE-GC-IDMS) with a hexane-tropolone mixture.

    Science.gov (United States)

    Konieczka, Piotr; Sejerøe-Olsen, Berit; Linsinger, Thomas P J; Schimmel, Heinz

    2007-06-01

    Extraction conditions for the determination of tributyltin (TBT) in sediment samples have been developed further. The analytical procedure is based on spiking with isotopically labelled analyte, pressurised liquid extraction (PLE) with a hexane/tropolone mixture, Grignard derivatization and quantification by GC-MS. It was applied to two unknown sediment samples as part of an intercomparison exercise of the Comité Consultatif pour la Quantité de Matière (CCQM). The detection limit was approximately 1.5 ng/g TBT as Sn, while the repeatability and intermediate precision (as the coefficient of variation) were 1.9% and 3.2%, respectively. The expanded uncertainty was 6.2% (coverage factor k = 2), and the accuracy was confirmed by measurement of a certified reference material.

  1. Atividade antibacteriana de floroglucinóis e do extrato hexânico de Hypericum brasiliense Choysi Antibacterial activity of the phloroglucinols and hexanic extract from Hypericum brasiliense Choysi

    Directory of Open Access Journals (Sweden)

    Hildegardo Seibert França

    2009-01-01

    Full Text Available Three phloroglucinols were obtained from Hypericum brasiliense: japonicine A (1, isouliginosin B (2 and uliginosin B (3. Bioautography and disk diffusion methods were used to determine antibacterial activity of the hexanic extract. Strains of the Coagulase Negative Staphylococcus and American Methicillin Resistant Staphylococcus aureus clones showed a growth inhibition zone ranging from 10 to 12 mm and 7 to 15 mm, respectively. Minimal inhibitory concentration (MIC values were used to measure antistaphylococcal activity for all phloroglucinols. Isouliginosin B and uliginosin B presented MIC values of 1.5 and 3.0 µg/mL, respectively, while japonicine A displayed MIC value of 50.0 µg/mL.

  2. Catalytic oxidation of n-hexane promoted by Ce{sub 1−x}Cu{sub x}O{sub 2} catalysts prepared by one-step polymeric precursor method

    Energy Technology Data Exchange (ETDEWEB)

    Araújo, Vinícius D., E-mail: dantas@ursa.ifsc.usp.br [Instituto de Física, Universidade de São Paulo – USP, 13560-970 São Carlos, SP (Brazil); Lima, Maurício M. de [Instituto de Ciencia de los Materiales, Universidad de Valencia, E-46071 Valencia (Spain); Fundación General, Universitat de Valencia, Valencia (Spain); Cantarero, Andrés [Instituto de Ciencia de los Materiales, Universidad de Valencia, E-46071 Valencia (Spain); Bernardi, Maria I.B. [Instituto de Física, Universidade de São Paulo – USP, 13560-970 São Carlos, SP (Brazil); Bellido, Jorge D.A. [CAP-Engenharia Química, Universidade Federal de São João Del-Rei – UFSJ, São João Del-Rei, MG (Brazil); Assaf, Elisabete M. [Instituto de Química, Universidade de São Paulo – USP, 13560-970 São Carlos, SP (Brazil); Balzer, Rosana; Probst, Luiz F.D. [Departamento de Química, Universidade Federal de Santa Catarina – UFSC, 88040-900 Florianópolis, SC (Brazil); Fajardo, Humberto V. [Departamento de Química, Universidade Federal de Ouro Preto – UFOP, 35400-000 Ouro Preto, MG (Brazil)

    2013-11-01

    Ceria-supported copper catalysts (Ce{sub 1−x}Cu{sub x}O{sub 2}, with x (mol) = 0, 0.01, 0.03, 0.05 and 0.10) were prepared in one step through the polymeric precursor method. The textural properties of the catalysts were investigated by X-ray diffraction (XRD), Rietveld refinement, N{sub 2}-physisorption (BET surface area), electron paramagnetic resonance (EPR), UV–visible diffuse reflectance and photoluminescence spectroscopies and temperature-programmed reduction (TPR). In a previous study ceria-supported copper catalysts were found to be efficient in the preferential oxidation of CO. In this study, we extended the catalytic application of Ce{sub 1−x}Cu{sub x}O{sub 2} systems to n-hexane oxidation and it was verified that the catalysts were highly efficient in the proposed reaction. The best performance (up to 95% conversion) was observed for the catalysts with low copper loads (Ce{sub 0.97}Cu{sub 0.03}O{sub 2} and Ce{sub 0.99}Cu{sub 0.01}O{sub 2}, respectively). The physicochemical characterizations revealed that these behaviors could be attributed to the copper species present in the catalysts and the interaction between CuO and CeO{sub 2}, which vary according to the copper content. - Highlights: • Synthesis of CuO/CeO2 catalysts by the one-step polymeric precursor method. • 95% n-hexane conversion on Ce0.97Cu0.03O2 catalyst. • Redox properties play a key role in the catalytic performance.

  3. A case report of motor neuron disease in a patient showing significant level of DDTs, HCHs and organophosphate metabolites in hair as well as levels of hexane and toluene in blood

    International Nuclear Information System (INIS)

    Kanavouras, Konstantinos; Tzatzarakis, Manolis N.; Mastorodemos, Vasileios; Plaitakis, Andreas; Tsatsakis, Aristidis M.

    2011-01-01

    Motor neuron disease is a devastating neurodegenerative condition, with the majority of sporadic, non-familial cases being of unknown etiology. Several epidemiological studies have suggested that occupational exposure to chemicals may be associated with disease pathogenesis. We report the case of a patient developing progressive motor neuron disease, who was chronically exposed to pesticides and organic solvents. The patient presented with leg spasticity and developed gradually clinical signs suggestive of amyotrophic lateral sclerosis, which was supported by the neurophysiologic and radiological findings. Our report is an evidence based case of combined exposure to organochlorine (DDTs), organophosphate pesticides (OPs) and organic solvents as confirmed by laboratory analysis in samples of blood and hair confirming systematic exposure. The concentration of non-specific dialkylphosphates metabolites (DAPs) of OPs in hair (dimethyphopshate (DMP) 1289.4 pg/mg and diethylphosphate (DEP) 709.4 pg/mg) and of DDTs (opDDE 484.0 pg/mg, ppDDE 526.6 pg/mg, opDDD 448.4 pg/mg, ppDDD + opDDT 259.9 pg/mg and ppDDT 573.7 pg/mg) were considerably significant. Toluene and n-hexane were also detected in blood on admission at hospital and quantified (1.23 and 0.87 μg/l, respectively), while 3 months after hospitalization blood testing was found negative for toluene and n-hexane and hair analysis was provided decrease levels of HCHs, DDTs and DAPs. -- Highlights: ► Exposure to pesticides and organic solvents might be a risk factor for sporadic MND. ► We report a patient who developed progressive upper and lower motor neuron disease. ► The patient had a history of occupational exposure to pesticides and solvents. ► High DDTs’ levels and increased levels of DMP and DEP were measured in his hair. ► The patients’ exposure to chemicals might have played a role in MND development.

  4. A case report of motor neuron disease in a patient showing significant level of DDTs, HCHs and organophosphate metabolites in hair as well as levels of hexane and toluene in blood

    Energy Technology Data Exchange (ETDEWEB)

    Kanavouras, Konstantinos [Department of Neurology, Medical School, University of Crete, Heraklion, Crete (Greece); Tzatzarakis, Manolis N. [Center of Toxicology Science and Research, University of Crete, Heraklion, Crete (Greece); Mastorodemos, Vasileios; Plaitakis, Andreas [Department of Neurology, Medical School, University of Crete, Heraklion, Crete (Greece); Tsatsakis, Aristidis M., E-mail: aris@med.uoc.gr [Center of Toxicology Science and Research, University of Crete, Heraklion, Crete (Greece)

    2011-11-15

    Motor neuron disease is a devastating neurodegenerative condition, with the majority of sporadic, non-familial cases being of unknown etiology. Several epidemiological studies have suggested that occupational exposure to chemicals may be associated with disease pathogenesis. We report the case of a patient developing progressive motor neuron disease, who was chronically exposed to pesticides and organic solvents. The patient presented with leg spasticity and developed gradually clinical signs suggestive of amyotrophic lateral sclerosis, which was supported by the neurophysiologic and radiological findings. Our report is an evidence based case of combined exposure to organochlorine (DDTs), organophosphate pesticides (OPs) and organic solvents as confirmed by laboratory analysis in samples of blood and hair confirming systematic exposure. The concentration of non-specific dialkylphosphates metabolites (DAPs) of OPs in hair (dimethyphopshate (DMP) 1289.4 pg/mg and diethylphosphate (DEP) 709.4 pg/mg) and of DDTs (opDDE 484.0 pg/mg, ppDDE 526.6 pg/mg, opDDD 448.4 pg/mg, ppDDD + opDDT 259.9 pg/mg and ppDDT 573.7 pg/mg) were considerably significant. Toluene and n-hexane were also detected in blood on admission at hospital and quantified (1.23 and 0.87 {mu}g/l, respectively), while 3 months after hospitalization blood testing was found negative for toluene and n-hexane and hair analysis was provided decrease levels of HCHs, DDTs and DAPs. -- Highlights: Black-Right-Pointing-Pointer Exposure to pesticides and organic solvents might be a risk factor for sporadic MND. Black-Right-Pointing-Pointer We report a patient who developed progressive upper and lower motor neuron disease. Black-Right-Pointing-Pointer The patient had a history of occupational exposure to pesticides and solvents. Black-Right-Pointing-Pointer High DDTs' levels and increased levels of DMP and DEP were measured in his hair. Black-Right-Pointing-Pointer The patients' exposure to chemicals might

  5. Determination of nucleic acids based on the quenching effect on resonance light scattering of the Y(III)-1,6-bi(1'-phenyl-3'-methyl-5'-pyrazolone-4'-)hexane-dione system.

    Science.gov (United States)

    Wu, Xia; Yang, Jing He; Sun, Shuna; Guo, Changying; Ran, Dehuan; Zheng, Jinhua

    2006-01-01

    Nucleic acids can quench resonance light scattering (RLS) intensity of the Y(III)-1,6-bi(1'-phenyl-3'-methyl-5'-pyrazolone-4'-)hexane-dione(BPMPHD) complex in the pH range 5.0-5.8. Under optimal conditions, there are linear relationships between the quenching of RLS and the concentration of nucleic acids in the range 6.3 x 10(-8)-2.1 x 10(-5) g/mL for fish sperm DNA (fsDNA), 1.2 x 10(-8)-5.0 x 10(-5) g/mL for calf thymus DNA (ctDNA) and 6.0 x 10(-8)-2.0 x 10(-5) g/mL for yeast RNA (yRNA). The detection limits (3 s) of fsDNA, ctDNA and yRNA are 0.7 ng/mL, 3.8 ng/mL and 4.2 ng/mL, respectively. Copyright (c) 2006 John Wiley & Sons, Ltd.

  6. Excess molar enthalpies and volumes of binary mixtures of two hydrofluoroethers with hexane, or benzene, or ethanol, or 1-propanol, or 2-butanone at T=298.15 K

    International Nuclear Information System (INIS)

    Ogawa, Hideo; Karashima, Shinya; Takigawa, Takayo; Murakami, Sachio

    2003-01-01

    Excess molar enthalpies and volumes at T=298.15 K are reported for binary mixtures of {1,1,2,3,3,3-hexafluoro-1-methoxypropane (HFE-356mec), [CF 3 CHFCF 2 -O-CH 3 ], or 1,1,2,2-tetrafluoro-1-(2,2,2-trifluoroethoxy)ethane (HFE-347pc-f) [CHF 2 CF 2 -O-CH 2 CF 3 ] + hexane (Hx), or benzene (Bz), or ethanol (EtOH), or 1-propanol (PrOH), or 2-butanone (MEK)}. The results of excess molar enthalpies are endothermic over the whole range of concentration, except for the MEK systems, in which excess molar enthalpies are exothermic over the whole range of concentration, and the EtOH systems, in which they are exothermic in the smaller mole fraction range. On the other hand, excess molar volumes are positive over the whole concentration range for all the mixtures. The values of the excess molar enthalpies for the (HFE-347pc-f + Hx) system show the linear composition dependence in the range of ca. 0.3< x<0.7, suggesting the quasi-stable state in solution. The results are explained by means of the destruction of the dipolar interactions and hydrogen bond in the pure component liquids, the difference of the dispersion interactions between the pure component liquid and solution, and the formation of the intermolecular hydrogen bond and dipolar interaction between unlike molecules

  7. Catalytic oxidation of volatile organic compounds (n-hexane, benzene, toluene, o-xylene promoted by cobalt catalysts supported on γ-Al2O3-CeO2

    Directory of Open Access Journals (Sweden)

    R. Balzer

    2014-09-01

    Full Text Available Cobalt catalysts supported on γ-alumina, ceria and γ-alumina-ceria, with 10 or 20%wt of cobalt load, prepared by the wet impregnation method and characterized by X-ray diffraction (XRD, scanning electron microscopy (SEM, field emission transmission electron microscopy (FETEM, N2 adsorption-desorption isotherms (BET/BJH methods, energy-dispersive X-ray spectroscopy (EDX, X-ray photoemission spectroscopy (XPS, O2-chemisorption and temperature programmed reduction (TPR were used to promote the oxidation of volatile organic compounds (n-hexane, benzene, toluene and o-xylene. For a range of low temperatures (50-350 °C, the activity of the catalysts with a higher cobalt load (20% wt was greater than that of the catalysts with a lower cobalt load (10% wt. The Co/γ-Al2O3-CeO2 catalytic systems presented the best performances. The results obtained in the characterization suggest that the higher catalytic activity of the Co20/γ-Al2O3-CeO2 catalyst may be attributed to the higher metal content and amount of oxygen vacancies, as well as the effects of the interaction between the cobalt and the alumina and cerium oxides.

  8. Excess molar volumes and deviation in viscosities of binary liquid mixtures of acrylic esters with hexane-1-ol at 303.15 and 313.15 K

    Directory of Open Access Journals (Sweden)

    Sujata S. Patil

    2014-12-01

    Full Text Available Densities and viscosities for the four binary liquid mixtures of methyl acrylate, ethyl acrylate, butyl acrylate and methyl methacrylate with hexane-1-ol at temperatures 303.15 and 313.15 K and at atmospheric pressure were measured over the entire composition range. These values were used to calculate excess molar volumes and deviation in viscosities which were fitted to Redlich–Kister polynomial equation. Recently proposed Jouyban Acree model was also used to correlate the experimental values of density and viscosity. The mixture viscosities were correlated by several semi-empirical approaches like Hind, Choudhary–Katti, Grunberg–Nissan, Tamura and Kurata, McAllister three and four body model equations. A graphical representation of excess molar volumes and deviation in isentropic compressibility shows positive nature whereas deviation in viscosity shows negative nature at both temperatures for all four binary liquid mixtures. Positive values of excess molar volumes show that volume expansion is taking place causing rupture of H-bonds in self associated alcohols. The results were discussed in terms of molecular interactions prevailing in the mixtures.

  9. A hexane fraction of guava Leaves (Psidium guajava L.) induces anticancer activity by suppressing AKT/mammalian target of rapamycin/ribosomal p70 S6 kinase in human prostate cancer cells.

    Science.gov (United States)

    Ryu, Nae Hyung; Park, Kyung-Ran; Kim, Sung-Moo; Yun, Hyung-Mun; Nam, Dongwoo; Lee, Seok-Geun; Jang, Hyeung-Jin; Ahn, Kyoo Seok; Kim, Sung-Hoon; Shim, Bum Sang; Choi, Seung-Hoon; Mosaddik, Ashik; Cho, Somi K; Ahn, Kwang Seok

    2012-03-01

    This study was carried out to evaluate the anticancer effects of guava leaf extracts and its fractions. The chemical compositions of the active extracts were also determined. In the present study, we set out to determine whether the anticancer effects of guava leaves are linked with their ability to suppress constitutive AKT/mammalian target of rapamycin (mTOR)/ribosomal p70 S6 kinase (S6K1) and mitogen-activated protein kinase (MAPK) activation pathways in human prostate cancer cells. We found that guava leaf hexane fraction (GHF) was the most potent inducer of cytotoxic and apoptotic effects in PC-3 cells. The molecular mechanism or mechanisms of GHF apoptotic potential were correlated with the suppression of AKT/mTOR/S6K1 and MAPK signaling pathways. This effect of GHF correlated with down-regulation of various proteins that mediate cell proliferation, cell survival, metastasis, and angiogenesis. Analysis of GHF by gas chromatography and gas chromatography-mass spectrometry tentatively identified 60 compounds, including β-eudesmol (11.98%), α-copaene (7.97%), phytol (7.95%), α-patchoulene (3.76%), β-caryophyllene oxide (CPO) (3.63%), caryophylla-3(15),7(14)-dien-6-ol (2.68%), (E)-methyl isoeugenol (1.90%), α-terpineol (1.76%), and octadecane (1.23%). Besides GHF, CPO, but not phytol, also inhibited the AKT/mTOR/S6K1 signaling pathway and induced apoptosis in prostate cancer cells. Overall, these findings suggest that guava leaves can interfere with multiple signaling cascades linked with tumorigenesis and provide a source of potential therapeutic compounds for both the prevention and treatment of cancer.

  10. The ignition delay, laminar flame speed and adiabatic temperature characteristics of n-pentane, n-hexane and n-heptane under O{sub 2}/CO{sub 2} atmosphere

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Ran [Huazhong Univ. of Science and Technology, Wuhan (China). State Key Lab. of Coal Combustion; Wuhan Textile Univ. (China). School of Environment and Urban Construction; Liu, Hao; Zhong, Xiaojiao; Wang, Zijian; Jin, Ziqin; Qiu, Jianrong [Huazhong Univ. of Science and Technology, Wuhan (China). State Key Lab. of Coal Combustion; Chen, Yingming [Wuhan Textile Univ. (China). School of Environment and Urban Construction

    2013-07-01

    Oxy-fuel (O{sub 2}/CO{sub 2}) combustion is one of the several promising new technologies which can realize the integrated control of CO{sub 2}, SO{sub 2}, NO{sub X} and other pollutants. However, when fuels are burned in the high CO{sub 2} concentration environment, the combustion characteristics can be very different from conventional air-fired combustion. Such changes imply that the high CO{sub 2} concentration atmosphere has impacts on the combustion processes. In this paper, the ignition time, laminar flame speed and adiabatic temperature property of C{sub 5} {proportional_to} C{sub 7} n-alkane fuels were studied under both ordinary air atmosphere and O{sub 2}/CO{sub 2} atmospheres over a wide range of CO{sub 2} concentration in the combustion systems. A new unified detailed chemical kinetic model was validated and used to simulate the three liquid hydrocarbon fuel's flame characteristics. Based on the verified model, the influences of various parameters (atmosphere, excess oxygen ratio, O{sub 2} concentration, CO{sub 2} concentration, and alkane type) on the C{sub 5} {proportional_to} C{sub 7} n-alkane's flame characteristics were systematically investigated. It can be concluded that high CO{sub 2} concentration atmosphere has negative effect on n-pentane, n-hexane and n-heptane flame's ignition, laminar flame speed and adiabatic temperature. Besides, this work confirms that high CO{sub 2} concentration atmosphere's chemical effects play a pronounced role on the flame characteristics, especially for the ignition time property.

  11. Evaluation of the Antioxidant and Anti-glication Effects of the Hexane Extract from Piper auritum Leaves in Vitro and Beneficial Activity on Oxidative Stress and Advanced Glycation End-Product-Mediated Renal Injury in Streptozotocin-Treated Diabetic Rats

    Directory of Open Access Journals (Sweden)

    Adriana Maria Neira Gonzalez

    2012-10-01

    Full Text Available The aim of this study was to investigate the antioxidant activity of hexane extracts from leaves of Piper auritum (HS. Eight complementary in vitro test methods were used, including inhibition of DPPH· radicals, nitric oxide, superoxide anion, ion-chelating, ABTS, oxygen radical absorbance capacity, β-carotene bleaching and peroxy radical scavenging. The results indicated that HS possesses high antioxidant activity. To add to these finding we tested the effect against oxidative stress in liver, pancreas and kidney in diabetic rats. Low levels of SOD, CAT, GPx and GSH in diabetic rats were reverted to near normal values after treatment with HS. These results suggest that P. auritum prevents oxidative stress, acting as a suppressor of liver cell damage. Given the link between glycation and oxidation, we proposed that HS might possess significant in vitro antiglycation activity. Our data confirmed the inhibitory effect of HS on bovine serum albumin, serum glycosylated protein, glycation of LDL, and glycation hemoglobin. The effect of HS on diabetic renal damage was investigated using streptozotocin-induced diabetic rats. The oral administration of HS at a dose of 200 and 400 mg/kg body weight/day for 28 days significantly reduced advanced glycation endproduct (AGE formation, elevated renal glucose and thiobarbituric acid-reactive substance levels in the kidneys of diabetic rats. This implies that HS would alleviate the oxidative stress under diabetes through the inhibition of lipid peroxidation. These findings indicate that oxidative stress is increased in the diabetic rat kidney and that HS can prevent renal damage associated with diabetes by attenuating the oxidative stress.

  12. 40 CFR 799.2155 - Commercial hexane.

    Science.gov (United States)

    2010-07-01

    ... study plans before this testing begins. (c) Health effects testing—(1) Subchronic inhalation toxicity—(i... provisions also apply: (1) High dose level. Unless limited by the physical/chemical nature or biological... provisions also apply: (i) Cell growth and maintenance. Appropriate culture media and incubation conditions...

  13. 2-Vinylpyridine–tris(pentafluorophenylborane hexane monosolvate

    Directory of Open Access Journals (Sweden)

    Marcus Klahn

    2012-04-01

    Full Text Available The title compound, C7H7N·B(C6F53·C6H14, was obtained by the stoichiometric reaction of 2-vinylpyridine and tris(pentafluorophenylborane in toluene. The formed adduct exhibits a restricted rotation along the B—N bond resulting in an asymmetry, which can be also observed in the 19F NMR spectra. The B—N distance is equivalent to the distances found for 2-methylpyridine and 2-ethylpyridine B(C6F53 adducts. For the final refinement, the contributions of disordered solvent molecules were removed from the diffraction data with SQUEEZE in PLATON [van der Sluis & Spek (1990. Acta Cryst. A46, 194–201; Spek (2009. Acta Cryst. D65, 148–155].

  14. CGAR E CGAR-EM na análise dos constituintes químicos isolados do extrato hexanico de Sebastiania argutidens (Euphorbiaceae HRGC and HRGC-MS in the analysis of the chemical constituents isolated from hexanic extract of Sebastiania argutidens (Euphorbiaceae

    Directory of Open Access Journals (Sweden)

    Alexsandro Branco

    2002-02-01

    Full Text Available The fractionation column with SiO2 of the hexane extract of Sebastiania argutidens (Euphorbiaceae yielded fractions containing hydrocarbons, carboxylic acids, sterols and pentacyclic triterpenes. Besides, one fraction showed the presence of several methyl esters, including four uncommon long chain palmitate esthers as minor components. The characterization of these chemical constituents have been done by High Resolution Gas Chromatography (HRGC and HRGC coupled to Mass Spectrometry (GC/MS. Campesterol, stigmasterol, b-sitosterol, glutin-5-en-3-ol were identified by HRGC co-injection with standards.

  15. Effects of intermolecular interactions on absorption intensities of the fundamental and the first, second, and third overtones of OH stretching vibrations of methanol and t-butanol‑d9 in n-hexane studied by visible/near-infrared/infrared spectroscopy

    Science.gov (United States)

    Morisawa, Yusuke; Suga, Arisa

    2018-05-01

    Visible (Vis), near-infrared (NIR) and IR spectra in the 15,600-2500 cm- 1 region were measured for methanol, methanol-d3, and t-butanol-d9 in n-hexane to investigate effects of intermolecular interaction on absorption intensities of the fundamental and the first, second, and third overtones of their OH stretching vibrations. The relative area intensities of OH stretching bands of free and hydrogen-bonded species were plotted versus the vibrational quantum number using logarithm plots (V = 1-4) for 0.5 M methanol, 0.5 M methanol‑d3, and 0.5 M t-butanol-d9 in n-hexane. In the logarithm plots the relative intensities of free species yield a linear dependence irrespective of the solutes while those of hydrogen-bonded species deviate significantly from the linearity. The observed results suggest that the modifications in dipole moment functions of the OH bond induced by the formation of the hydrogen bondings change transient dipole moment, leading to the deviations of the dependences of relative absorption intensities on the vibrational quantum number from the linearity.

  16. Aislamiento y caracterización de la fracción hexánica de las hojas de Vernonanthura patens (Kunth H. Rob. con actividad antifúngica Isolation and characterization of hexane fraction from Vernonanthura patens (Kunth H. Rob leaves with antifungal action

    Directory of Open Access Journals (Sweden)

    Patricia Manzano Santana

    2012-09-01

    extract from the leaves was fractionated by column chromatography using the following solvent systems: hexane, hexane/ethyl acetate, ethyl acetate and ethyl acetate/methanol. Antifungal activity was measured by the agar diffusion technique with PDA medium in 5 mm wells, by adding 20 µL fractions at concentrations of 100 and 200 µg/mL dissolved in dimethylsulfoxide. The active fraction was analyzed for structural identification by gas chromatography-mass spectrometry. Results: of the fractions obtained, only the 100% hexane fraction showed antifungal activity, since its inhibitory percentages were 57.6 and 80.2 % against Penicillium notatum and 64.8 and 81.5 % vs. Fusaryum oxysporum on the fifteenth day of incubation. The structures of 29 compounds were suggested to be the constituents of the hexane fraction, most of them hydrocarbons. Conclusions: the presence of antifungal activity in the 100 % hexane fraction was proved, which can extend the medicinal uses of the studied plant and to enrich the Ecuadorian folk medicine.

  17. Chemical composition of the essential oil and hexanic fraction of Lippia and Lantana species Composição química do óleo essencial e fração hexânica de espécies de Lippia e Lantana

    Directory of Open Access Journals (Sweden)

    Pâmela S. Silva

    2010-12-01

    Full Text Available A comparison between two extraction approaches of volatiles compounds from six species of Verbenaceae collected at Serra do Cipó, Minas Gerais, Brazil was done. The essential oil and hexanic fraction of leaves from two Lantana and four Lippia species collected in two different seasons were analyzed by GC/MS. Among various identified compounds from both extraction methods the majority of species showed major amounts of β-caryophyllene followed by germacrene D, bicyclogermacrene and α-pinene. Few differences were observed between the composition of essential oil and the hexanic fraction regarding the two studied genera. These results suggest that the analysis of hexanic fraction can be used, as an alternative way, to analyze the volatile compounds of the essential oil.Foi realizada a comparação entre dois métodos de extração dos compostos voláteis obtidos de seis espécies de Verbenaceae, coletadas na Serra do Cipó, Minas Gerais, Brasil. Os óleos essenciais e as frações hexanica obtidos das folhas de duas espécies de Lantana e quatro espécies de Lippia, coletadas em duas diferentes estações do ano, foram analisados por CG/EM. Grande número de constituintes foi identificado nas amostras oriundas dos dois métodos de extração e o componente majoritário para a maior parte das espécies foi o β-cariofileno, seguido pelo germacreno D, biciclogermacreno e α-pineno. Para os dois gêneros estudados, foram observadas pequenas diferenças na composição do óleo essencial e fração hexânica. Esses resultados sugerem que a análise da fração hexânica pode ser usada para identificar os componentes voláteis majoritários dessas espécies, além de ser uma técnica alternativa para a análise dos compostos voláteis presentes no óleo essencial, uma vez que ambos mostraram composição similar.

  18. Fungitoxic activity avaliation of the hexane and methanol extracts of copaiba plant leavesCopaifera langsdorffi Desfon Avaliação da atividade fungitóxica dos extratos foliares hexânico e metanólico da Copaifera langsdorffi Desfon

    Directory of Open Access Journals (Sweden)

    Ana Carolina Lourenço Amorim

    2004-04-01

    Full Text Available The fungitoxicity of hexane and methanol extracts of copaiba plants were evaluated by biological tests against the phytopathogens Colletotrichum gloeosporioides and Bipolaris sorokiniana. These extracts were chosen because they presented the highest yields in the extraction at room temperature. The biological material was obtained from the Department of Phytopathology of the UFLA, transplanted in BDA (C. gloeosporioides and PCA (B. sorokiniana culture media and incubated in a germination chamber with control of light and temperature. Five treatments (0/100/200/400/800 ppm were used with three repetitions of each, and four mutually perpendicular radii, were measured in centimeters from the mycelial center. The formula for the Mycelial Growth Index (MGI was applied to the values obtained for statistical analyses. A 32% reduction in the growth of B. sorokiniana was observed in the presence of the methanol extract, while the hexane extract was effective against both of the phytopathogens, resulting in a 49% reduction in the growth of B. sorokiniana and an 18% reduction in the growth of C. gloeosporioides.Avaliou-se a fungitoxicidade dos extratos hexânico e metanólico do óleo copaíba por meio de ensaios biológicos contra os fitopatógenos Colletotrichum gloeosporioides e Bipolaris sorokiniana. Os referidos extratos foram escolhidos em razão dos melhores rendimentos obtidos na extração a frio. O material biológico foi obtido na UFLA no Departamento de Fitopatologia, repicado em meio de cultura BDA (C. gloeosporioides e PCA (B. sorokiniana e incubados em câmara de germinação com controle de temperatura e luz. Empregaram-se cinco tratamentos (0/100/200/400/800 ppm, realizando-se três repetições e avaliando-se quatro raios, medidos em centímetros, a partir do micélio central. Os valores aferidos foram aplicados à fórmula do Índice de Crescimento Micelial (ICM para as análises estatísticas. Observou-se que o extrato metan

  19. Study of thermodynamic and transport properties of binary liquid mixtures of n-decane with hexan-2-ol, heptan-2-ol and octan-2-ol at T = 298.15 K. Experimental results and application of the Prigogine–Flory–Patterson theory

    International Nuclear Information System (INIS)

    Mahajan, Aravind R.; Mirgane, Sunil R.

    2013-01-01

    Highlights: • The large positive V m E values are obtained for the binary mixtures at 298.15 K. • Excess isentropic compressibilities for the binary mixtures are positive over the whole composition range. • The values of G ∗E for all binary mixtures are negative over entire mole fraction. • Viscosities measured for the binary mixtures were correlated with values calculated by various viscosity models. • PEP theory, Bloomfield and Dewan model and Jouyban–Acree model are also used to correlate the experimental data. -- Abstract: Densities and viscosities of binary mixtures of n-decane with hexan-2-ol, heptan-2-ol and octan-2-ol have been measured over the entire range of composition at T = 298.15 K and at atmospheric pressure. From the experimental values of density and viscosity, the excess molar volumes (V m E ) and excess Gibbs energy of activation of viscous flow (G ∗E ) have been calculated. These results were fitted to Redlich–Kister polynomial equations to estimate the binary coefficients and standard errors. Jouyban–Acree model is used to correlate the experimental values of density, viscosity and ultrasonic velocity at T = 298.15 K. The results of the viscosity-composition are discussed in the light of various viscosity semi-empirical equations. The experimental results have been used to test the applicability of the Prigogine–Flory–Patterson (PFP) theory. The values of Δln η have also been analysed using Bloomfield and Dewan model. The experimental and calculated quantities are used to study the nature of mixing behaviour between the mixtures

  20. The Effect Of Hexane Extract Of Azidirachta indica Leaves On ...

    African Journals Online (AJOL)

    Improved Neubauer's chamber was used to determine the testicular sperm reserve. The right testis, liver, kidney and spleen were routinely prepared for light microscopy. The control mice had significantly higher (P<0.05) testicular sperm reserve than the treatment group mice, which received the highest dose of the extract.

  1. Physicochemical characterisation of hexanic seed oil extract from ...

    African Journals Online (AJOL)

    Nyakudya, Trevor

    2013-02-20

    Feb 20, 2013 ... Erlwanger4, Mazuru B. Gundidza5, Michael L. Magwa6 and Perkin Muredzi7 ... possess several physiological side effects, hence the .... Physical and chemical properties of S. molle seed oil ..... composition of Schinus molle essential oil and its cytotoxic activity on ... cultivars (Linum usitatissimum L.). Gen.

  2. Hexanic fraction of turmeric powder attenuates murine model of ...

    African Journals Online (AJOL)

    ... of any detectable toxicity and sedative effects exerts pronounced peripheral and central antinociceptive effects, with no involvement of opioidergic system but possibly related to its ability to interact with TRPV1 receptors and the glutamatergic system. Keywords: Curcuma longa L., Antinociceptive, TRPV1, Glutamatergic ...

  3. Hexane extract of Dacryodes edulis fruits possesses anti-diabetic ...

    African Journals Online (AJOL)

    Background: The fruit extract of Dacryodes edulis (D. edulis), the African pear or plum, a tree indigenous to the humid tropics has been used for managing wounds, skin diseases, sickle cell anaemia, dysentery and fever in some African nations. In South Eastern Nigeria, 'herbal doctors' include its marshed fruit in decoctions ...

  4. Gastroprotective Activities of the n-Hexane Fraction of Heliotropium ...

    African Journals Online (AJOL)

    ) to evaluate the histo- gastroprotective effects of H. indicum on Indomethacin – induced gastric ulcerated mucosa of wistar rats. None of the rats used in this study died while the experimental procedures lasted. Thus, all rats were histologically.

  5. Cytotoxic Activity of Hexane Extracts of Psidium guajava L ...

    African Journals Online (AJOL)

    , kaempferol, which was identified as a constituent of the extract. Conclusion: The results suggest that further chemical analysis and mechanistic investigations should be conducted on P. guajava and C. alata extracts to validate their potential ...

  6. Cytotoxic Activity of Hexane Extracts of Psidium Guajava L ...

    African Journals Online (AJOL)

    HP

    , kaempferol, which was identified as a constituent of the extract. Conclusion: The results suggest that further chemical analysis and mechanistic investigations should be conducted on P. guajava and C. alata extracts to validate their potential ...

  7. Separation of Azeotropic Mixture Acetone + Hexane by Using Polydimethylsiloxane Membrane.

    Czech Academy of Sciences Publication Activity Database

    Randová, A.; Bartovská, L.; Kačírková, Marie; Ledesma, Oscar Iván Hernández; Červenková Šťastná, Lucie; Izák, Pavel; Žitková, Andrea; Friess, K.

    2016-01-01

    Roč. 170, OCT 1 (2016), s. 256-263 ISSN 1383-5866 R&D Projects: GA MŠk(CZ) LD14094 Institutional support: RVO:67985858 Keywords : azeotropic mixture * PDMS membrane * pervaporation Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 3.359, year: 2016

  8. hexane extracts of the husk of Cocos nucifera

    African Journals Online (AJOL)

    Jane

    2011-04-25

    Apr 25, 2011 ... (Esquenazi, 2002) and in India, heating the coconut shells gives ... MATERIALS AND METHODS ... sterilized molten Mueller-Hinton agar at 40°C to give final .... and 8 h, respectively, and transferred to 4.5 ml of nutrient broth.

  9. Haematological and biochemical evaluation of the n -hexane extract ...

    African Journals Online (AJOL)

    The study undertook to evaluate the sub-chronic toxicological profile of the seed of Ricinus communis var. minor (RICOM-1013-J), widely used as anticonceptive agent among Bassa people of Plateau State, Nigeria, on haematological and biochemical parameters in adult rats. Thirty-six (36) adult female rats were divided ...

  10. Anti-venom Potentials of Friedelin Isolated from Hexane Extract

    African Journals Online (AJOL)

    USER

    474. Selvanayagam et al.,1995). Quite a good record of plant anti-venom agents used among the various ethnic groups and regions of Nigeria has been established through ethnobanical and ethnomedical records. Notably ...... Guidelines for the Management of snake-bites. WHO Library Cataloguing-in-. Publication data ...

  11. Effect Of Chronic Administration Of Hexane Extract Of Byrsonima ...

    African Journals Online (AJOL)

    Background: In Mexican traditional medicine, the seeds of Byrsonima crassifolia have been used in the treatment of diabetes, rheumatism and for wound healing. The aim was to evaluate the effect of seeds of B. crassifolia on insulin release from the pancreatic beta cells in streptozotocininduced diabetic rats. Materials and ...

  12. Efficacy and safety of a hexanic extract of Serenoa repens (Permixon® ) for the treatment of lower urinary tract symptoms associated with benign prostatic hyperplasia (LUTS/BPH): Systematic review and meta-analysis of randomized controlled trials and observational studies.

    Science.gov (United States)

    Vela-Navarrete, Remigio; Alcaraz, Antonio; Rodríguez-Antolín, Alfredo; Miñana López, Bernardino; Fernández-Gómez, Jesús M; Angulo, Javier C; Castro Díaz, David; Romero-Otero, Javier; Brenes, Francisco J; Carballido, Joaquín; Molero García, José M; Fernández-Pro Ledesma, Antonio; Cózar Olmos, José Manuel; Manasanch Dalmau, José; Subirana Cachinero, Isaac; Herdman, Michael; Ficarra, Vincenzo

    2018-04-25

    To comprehensively evaluate the efficacy and safety of the hexanic extract of Serenoa repens (HESr, Permixon), at a dose of 320 mg daily, as monotherapy for the treatment of LUTS/BPH. Systematic review and meta-analysis of randomized and observational studies in patients with LUTS/BPH identified through searches in Medline, Web of Knowledge [ISI], Scopus, the Cochrane Library, and bibliographic references up to March 2017. Articles studying S. repens extracts other than Permixon were excluded. Data was collected on IPSS score, peak urinary flow (Qmax), nocturia, quality of life, prostate volume, sexual function, and adverse drug reactions (ADR). Data obtained from randomized controlled trials (RCT) and observational studies (OS) were analysed jointly and separately using a random effects model. A sub-group analysis was performed of studies which included patients on longer-term treatment (≥one year). Data from 27 studies (15 RCTs and 12 OS) were included for meta-analysis (total N=5,800). Compared with placebo, the HESr was associated with 0.64 (95% CI -0.98 to -0.31) fewer voids per night (p=0.0001) and an additional mean increase in Qmax of 2.75 mL/s (95% CI 0.57 to 4.93; p=0.01). When compared with alpha-blockers, the HESr showed similar improvements on IPSS (WMD 0.57; 95%CI, -0.27 to 1.42; p=0.18) and a comparable increase in Qmax to tamsulosin (WMD -0.02; 95%CI, -0.71 to 0.66; p=0.95). Efficacy assessed using the IPSS was similar after 6 months of treatment between the HESr and 5ARIs. Analysis of all available published data for the HESr showed a mean improvement in IPSS score from baseline of -5.73 points (95% CI -6.91 to -4.54; pBPH. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  13. Evaluation of the anti-inflammatory properties of the hexane extract ...

    African Journals Online (AJOL)

    Maj Obaseki

    2016-08-26

    Aug 26, 2016 ... side effects to substitute for these chemical therapeutics. The use of plants ...... Occurrence, Structure and Role in the Human Diet. UK: Blackwell .... 1. The effect of histamine and serotonin on vascular permeability: an electron.

  14. endo-3,3-Dimethyl-4-oxobicyclo[3.1.0]hexan-2-yl methanesulfonate

    Directory of Open Access Journals (Sweden)

    Adrian Kremer

    2010-04-01

    Full Text Available The relative configuration of the endo isomer of the title compound, C9H14O4S, has been established and the conformation of the diastereoisomer is discussed. The five-membered ring adopts an envelope conformation. The conformation of the methanesulfonate substituent is stabilized by intermolecular C—H...O hydrogen bonds. The crystal packing results in alternating layers of polar methanesulfonates and stacked bicyclohexanyl rings parallel to ab.

  15. 1,1′-(Hexane-1,6-diylbis(indoline-2,3-dione

    Directory of Open Access Journals (Sweden)

    Fatima Zahrae Qachchachi

    2016-04-01

    Full Text Available The molecule of the title compound, C22H20N2O4, is situated on a crystallographic centre of symmetry. The two indoline-2,3-dione fragments are linked by a hexylene group at each N atom. In the crystal, supramolecular layers propagating in the ac plane are formed via C—H...O hydrogen bonds.

  16. Analgesic and Anti-inflammatory Profile of n-Hexane Fraction of ...

    African Journals Online (AJOL)

    HP

    inflammatory activities (carrageenan-induced and histamine-induced edema models) in BALB/c mice. Results: VBHF exhibited significant (p ... The analgesic effect of VBHF was dose-dependent in acetic acid pain model while the extract was a weak ... In Pakistan, it is found in Swat, Hazara and. Dir and used as antipyretic, ...

  17. 40 CFR 795.232 - Inhalation and dermal pharmacokinetics of commercial hexane.

    Science.gov (United States)

    2010-07-01

    ... studies of volatile solvents in hairless mice. I. Description of a skin depot”, In: Journal of Applied... concentration. (C) Dermal studies. The test substance shall be applied and kept on the skin for a minimum of 6... data shall be evaluated by appropriate statistical methods. (3) Reporting results. In addition to the...

  18. Adverse health effects of cigarette smoke: aldehydes Crotonaldehyde, butyraldehyde, hexanal and malonaldehyde

    NARCIS (Netherlands)

    Andel I van; Sleijffers A; Schenk E; Rambali B; Wolterink G; Werken G van de; Aerts LAGJM van; Vleeming W; Amsterdam JGC van; TOX

    2006-01-01

    Crotonaldehyde in cigarette smoke can be concluded to induce airway damage in humans. This is one conclusion derived from the existing data found in the literature and reported here in the discussion on adverse health effects and possible addictive effects due to the exposure of crotonaldehyde,

  19. Chemical kinetic insights into the ignition dynamics of n-hexane

    KAUST Repository

    Tingas, Alexandros; Wang, Zhandong; Sarathy, Mani; Im, Hong G.; Goussis, Dimitris A.

    2017-01-01

    Normal alkanes constitute a significant fraction of transportation fuels, and are the primary drivers of ignition processes in gasoline and diesel fuels. Low temperature ignition of n-alkanes is driven by a complex sequence of oxidation reactions

  20. Acute symptoms during non-inhalation exposure to combinations of toluene, trichloroethylene, and n-hexane

    DEFF Research Database (Denmark)

    Bælum, Jesper

    1999-01-01

    To study the acute effect of exposure to a mixture of three commonly used solvents in humans using a route of exposure not involving the nose and lungs, in this case a gastrointestinal application....

  1. Vapor pressures and thermophysical properties of selected hexenols and recommended vapor pressure for hexan-1-ol

    Czech Academy of Sciences Publication Activity Database

    Štejfa, V.; Fulem, Michal; Růžička, K.; Matějka, P.

    2015-01-01

    Roč. 402, Sep (2015), 18-29 ISSN 0378-3812 Institutional support: RVO:68378271 Keywords : alcohols * vapor pressure * heat capacity * ideal - gas thermodynamic properties * vaporization enthalpy Subject RIV: BJ - Thermodynamics Impact factor: 1.846, year: 2015

  2. Oxidative cracking of n-hexane: a catalytic pathway to olefins

    NARCIS (Netherlands)

    Boyadjian, C.A.

    2010-01-01

    Steam cracking, the major, current existing route for light olefin production, is the most energy consuming process in the chemical industry. The need for an energy efficient processes, urged substantial research work for the development of new catalytic technologies for light olefin production.

  3. Hexane-1,6-diaminium bis[3,4,5,6-tetrachloro-2-(methoxycarbonylbenzoate

    Directory of Open Access Journals (Sweden)

    Jian Li

    2011-04-01

    Full Text Available In the anion of the title salt, C6H18N22+·2C9H3Cl4O4−, the methoxycarbonyl and carboxyl groups are aligned at dihedral angles of 71.0 (3 and 100.9 (3°, respectively, with the aromatic ring. The asymmetric unit contains half a cation and one anion. In the crystal, intermolecular N—H...O, C—H...Cl and C—H...O hydrogen bonds link the components into a three-dimensional network.

  4. Effect of methanol, n-hexane and aqueous extract of Irvingia ...

    African Journals Online (AJOL)

    children below 5 years in Asia, Latin America and Africa resulting in 4-5 million deaths. (Abdullahi et al. ... two years of life and declines as a child grows older. Mortality from diarrhoea has declined over the past two ... powder was weighed using an electric weighing balance by Kern ALS 220 – 4. The powder was then ...

  5. Tetracarbonylbis(η5-cyclopentadienylbis(diphenylphosphinedimolybdenum(Mo—Mo hexane solvate

    Directory of Open Access Journals (Sweden)

    David R. Tyler

    2008-07-01

    Full Text Available The title compound, [Mo2(C5H52(C12H11P2(CO4]·C6H14, is a centrosymmetric Mo complex in which two Mo atoms are connected by an Mo—Mo bond [3.2072 (12 Å]. Each Mo atom is coordinated by an η5-cyclopentadienyl ligand, two carbonyl ligands and a diphenylphosphine ligand in a piano-stool fashion.

  6. Adsorption of halogenated hydrocarbons to microporous adsorbents. Pt. 1; Calorimetric measurement of the heat of adsorption of perfluoro-n-hexane and n-hexanes on zeolites of the faujasite type. Untersuchungen zur Adsorption von halogenierten Kohlenwasserstoffen an mikroporoesen Adsorbenzien. T. 1; Kalorimetrische Messung der Adsorptionswaerme von Perfluor-n-hexan and n-Hexan an Zeolithen vom Faujasityp

    Energy Technology Data Exchange (ETDEWEB)

    Stach, H [Adlershofer Umweltschutztechnik- und Forschungsgesellschaft mbH, Berlin (Germany); Sigrist, K; Ruediger, S; Gross, U

    1993-06-01

    The differential molar heats of adsorption were measured for n-C[sub 6]F[sub 14] and n-C[sub 6]H[sub 14] on two different zeolites of faujasite-type at 303 K by using a Calvet-type calorimeter. Comparing the heat curves of the perfluorinated compound on NaX and DY it is found that the molecular sieve with the smaller Si/Al ratio (higher electrostatic field) exhibits an about 10 kJ/mol larger heat of adsorption than the zeolite with the higher Si/Al ratio. The substitution of the H-atoms in the hydrocarbon by F-atoms brings about an increase of the adsorption heat for n-C[sub 6]F[sub 14] of 9.0 and 6.0 kJ/mol on the zeolites NaX and DY, respectively. Using a simple approximate equation the zero heats of adsorption of n-paraffins and perfluoro-n-paraffins from C[sub 1] to C[sub 7] were calculated. (orig.)

  7. Evaluation of the anti-inflammatory properties of the hexane extract ...

    African Journals Online (AJOL)

    Maj Obaseki

    2016-08-26

    Aug 26, 2016 ... and human red blood cell (HRBC) membrane stabilization assays. ... bonariensis affirms the anti-inflammatory property of the plant and the phytochemicals ..... Plasma for liver function tests was obtained by centrifuging the.

  8. Evaluation of the anti-inflammatory properties of the hexane extract ...

    African Journals Online (AJOL)

    The extract was finally subjected to GC/MS analysis for the tentative identification of the phytochemical constituents. Phytochemical analysis of the extract revealed the presence of saponin, phenol, flavonoid, tannin, terpenoid and sterol. This extract showed the ability to inhibit thermally-induced protein denaturation and ...

  9. GC-MS analysis of hexane extract of Jatropha curcas L. seed oil

    OpenAIRE

    Warra, Aliyu A.; Abubakar, Ahmed

    2015-01-01

    The spectral interpretation here was based on compounds identification. The following fatty acids were identified considering the peaks and library fragments; Oleic acid, Stearic acid, Palmitic acid Margaric acid, 6-Octadecenoic acid, Elaidic acid Erucic acid, Methyl ricinoleate, 11-octadecenoic acid,10-undecenoic acid. The results indicated that the Jatropha curcas L seed oil has potential in the production of cosmetics, perfumery and pharmaceuticals.The spectral interpretation here was ba...

  10. CCDC 1429347: Experimental Crystal Structure Determination : tetraphenylphosphonium octadecakis(mu-2,4-dimethylbenzenethiolato)-gold-tetracosa-silver hexane solvate

    KAUST Repository

    Bootharaju, Megalamane Siddaramappa

    2015-01-01

    An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

  11. Dynamics of adsorption of polyallylamine hydrochloride/sodium dodecyl sulphate at water/air and water/hexane interfaces

    Czech Academy of Sciences Publication Activity Database

    Sharipova, A.; Aidarova, S.; Fainerman, V. B.; Stocco, A.; Černoch, Peter; Miller, R.

    2011-01-01

    Roč. 391, 1-3 (2011), s. 112-118 ISSN 0927-7757. [International Symposium on Surfactants in Solution /18./ - SIS 2010. Melbourne, 14.11.2010-19.11.2010] Institutional research plan: CEZ:AV0Z40500505 Keywords : mixed adsorption layers * polymer/surfactant mixtures * water /oil interface Subject RIV: CD - Macromolecular Chemistry Impact factor: 2.236, year: 2011

  12. Molecular Dynamics Simulations of n-Hexane at 1-Butyl-3-Methylimidazolium bis(trifluoromethylsulfonyl) Imide Interface

    Czech Academy of Sciences Publication Activity Database

    Lísal, Martin; Izák, Pavel

    2013-01-01

    Roč. 139, č. 1 (2013), 014704 ISSN 0021-9606 R&D Projects: GA ČR(CZ) GAP106/12/0569; GA MŠk LH12020 Institutional support: RVO:67985858 Keywords : temperature ionic liquid s * electric double-layer * rutile 110 surface Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 3.122, year: 2013

  13. PFG NMR Study of Liquid n-Hexane Self-Diffusion in the Bed of Porous Glass Beads

    Czech Academy of Sciences Publication Activity Database

    Peksa, M.; Lang, J.; Kočiřík, Milan

    2009-01-01

    Roč. 11, č. 36 (2009), s. 1-2 ISSN 1862-4138 R&D Projects: GA ČR GA203/09/1353 Institutional research plan: CEZ:AV0Z40400503 Keywords : PFG NMR Study * porous glass beads Subject RIV: CF - Physical ; Theoretical Chemistry http://www.uni-leipzig.de/diffusion/journal/index.html

  14. Comparison of Hexane Vapour Permeation in Two Different Polymeric Membranes via an Innovative In-Line FID Detection Method.

    Czech Academy of Sciences Publication Activity Database

    Petrusová, Zuzana; Morávková, Lenka; Vejražka, Jiří; Vajglová, Zuzana; Jansen, J.C.; Izák, Pavel

    2017-01-01

    Roč. 31, č. 2 (2017), s. 145-160 ISSN 0352-9568. [International Congress of Chemical and Process Engineering CHISA 2016 /22./. Prague, 27.08.2016-31.08.2016] R&D Projects: GA MŠk(CZ) LD14094 Institutional support: RVO:67985858 Keywords : gas/vapour separation * low-density polyethylene * thin-film-composite membrane Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 0.923, year: 2016

  15. n-Hexane induced swelling of thin PDMS films under non-equilibrium nanofiltration permeation conditions, resolved by spectroscopic ellipsometry

    NARCIS (Netherlands)

    Ogieglo, Wojciech; van der Werf, J.C.A.; Tempelman, Kristianne; Wormeester, Herbert; Wessling, Matthias; Nijmeijer, Arian; Benes, Nieck Edwin

    2013-01-01

    A nondestructivetechniqueispresentedforin-situanalysisofsolventinducedmembraneswelling.The techniqueisbasedonspectroscopicellipsometry(SE)andallowssimultaneousmeasurementof membranefilmthicknessandsolventsorption.Theattainableexperimentalconditionsareonlylimited by thetestcell(r473.15 K, r20

  16. 1,6-Bis[(2,2′:6′,2′′-terpyridin-4′-yloxy]hexane

    Directory of Open Access Journals (Sweden)

    Varvara I. Nikolayenko

    2012-07-01

    Full Text Available The molecule of the title compound, C36H32N6O2, lies about an inversion center, located at the mid-point of the central C—C bond of the diether bridge. The terminal pyridine rings form dihedral angles of 4.67 (7 and 26.23 (7° with the central ring. In the crystal, weak C—H...N and C—H...O interactions link the molecules into a three-dimensional network.

  17. Use of 2,5-dimethyl-2,5-hexane diamine as a curing agent for epoxy resins. [Patent application

    Science.gov (United States)

    Rinde, J.A.; Newey, H.A.

    Primary diamines are prepared for use as a curing agent for epoxy resins. These curing agents can be used to form epoxy resin mixtures useful in filament winding and preimpregnated fiber molding and in formulating film adhesives, powder coatings and molding powders. The epoxy mixtures form for such uses a room temperature non-reacting, intermediate stable state which has a latent cross-linking capability.

  18. Effect of surfactant hydrophobicity on the interfacial properties of polyallylamine hydrochloride/sodium alkylsulphate at water/hexane interface

    Czech Academy of Sciences Publication Activity Database

    Sharipova, A.; Aidarova, S.; Černoch, Peter; Miller, R.

    2013-01-01

    Roč. 438, 5 December (2013), s. 141-147 ISSN 0927-7757. [EUFOAM Conference /9./. Lisbon, 08.07.2012-11.07.2012] Institutional support: RVO:61389013 Keywords : mixed adsorption layers * polymer-surfactant mixtures * water/oil interface Subject RIV: CD - Macromolecular Chemistry Impact factor: 2.354, year: 2013

  19. CCDC 1428877: Experimental Crystal Structure Determination : tetraphenylphosphonium octadecakis(mu-2,4-dimethylbenzenethiolato)-pentacosa-silver n-hexane dichloromethane solvate

    KAUST Repository

    Joshi, Chakra Prasad

    2015-01-01

    An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

  20. Contribution to the application of the langmuir probe technique for plasma monitoring in the Ar and n-hexane mixture plasma during the polymerisation proces

    Czech Academy of Sciences Publication Activity Database

    Adámek, P.; Kalčík, J.; Šícha, M.; Tichý, M.; Biederman, H.; Soukup, Ladislav; Jastrabík, Lubomír

    1999-01-01

    Roč. 49, č. 12 (1999), s. 1685-1701 ISSN 0011-4626 R&D Projects: GA ČR GA202/98/0666 Institutional research plan: CEZ:AV0Z1010914 Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 0.328, year: 1999

  1. Contribution to the application of the Langmuir probe techique for plasma monitoring in the Ar and n-hexane mixture plasma during the polymerisation process

    Czech Academy of Sciences Publication Activity Database

    Adámek, P.; Kalčík, J.; Šícha, M.; Tichý, M.; Biederman, H.; Soukup, Ladislav; Jastrabík, Lubomír

    1999-01-01

    Roč. 49, č. 12 (1999), s. 1685-1700 ISSN 0011-4626 R&D Projects: GA MŠk(CZ) OC 516.50; GA ČR(CZ) GA202/97/1011; GA ČR(CZ) GA202/98/0116; GA ČR(CZ) GA202/98/0666 Grant - others:GA UK(CZ) 75/98 Institutional research plan: CEZ:AV0Z1010914 Keywords : Langmuir probe * plasma monitoring * average energy of electrons * polymerisation process Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 0.328, year: 1999

  2. Excess Molar Volumes of the (Cyclohexane + Pentane, or Hexane, or Heptane, or Octane, or Nonane) Systems at Temperature 298.15 K

    Czech Academy of Sciences Publication Activity Database

    Balán, J.; Morávková, Lenka; Linek, Jan

    2007-01-01

    Roč. 61, č. 6 (2007), s. 497-501 ISSN 0366-6352 R&D Projects: GA ČR(CZ) GA104/06/0656 Institutional research plan: CEZ:AV0Z40720504 Keywords : hydrocarbon * density * excess volume Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 0.367, year: 2007

  3. A P,O,P′-tridentate mixed-donor scorpionate ligand: 6-[4,6-bis(diphenylphosphino-10H-phenoxazin-10-yl]hexan-1-ol

    Directory of Open Access Journals (Sweden)

    Holger B. Friedrich

    2008-10-01

    Full Text Available The title compound, C42H39NO2P2, is a P,O,P′-tridentate scorpionate-type ligand and has one molecule in the asymmetric unit. The angles involving the P atoms range from 100.21 (7 to 104.89 (7°. The N-hexanol group was found to be disordered and was refined over two positions with final occupancies of 0.683 (3 and 0.317 (3 which affected the C—O and C—N bond lengths. The bond lengths for C—O range from 1.402 (2 to 1.415 (2 Å and for C—N from 1.410 (2 to 1.448 (3 Å for the major disorder component; the corresponding ranges for the minor disorder component are 1.429 (3–1.408 (3 and 1.474 (3–1.474 (4 Å.

  4. Chemical Composition and Mosquitocidal activity of n-Hexane and Methanol Extracts from Euphorbia anacampseros var. tmolea, an endemic species of Turkey, against Aedes aegypti

    Science.gov (United States)

    New and safe mosquito control agents are necessary due to increasing resistance to synthetic insecticides and environmental change. The mosquito larvicidal and adulticidal activity and chemical composition of Euphorbia anacampseros var. tmolea extracts are investigated in this article for the first ...

  5. Development of an enantiomer-specific stable carbon isotope analysis (ESIA) method for assessing the fate of α-hexachlorocyclo-hexane in the environment.

    Science.gov (United States)

    Badea, Silviu-Laurentiu; Vogt, Carsten; Gehre, Matthias; Fischer, Anko; Danet, Andrei-Florin; Richnow, Hans-Hermann

    2011-05-30

    α-Hexachlorocyclohexane (α-HCH) is the only chiral isomer of the eight 1,2,3,4,5,6-HCHs and we have developed an enantiomer-specific stable carbon isotope analysis (ESIA) method for the evaluation of its fate in the environment. The carbon isotope ratios of the α-HCH enantiomers were determined for a commercially available α-HCH sample using a gas chromatography-combustion-isotope ratio mass spectrometry (GC-C-IRMS) system equipped with a chiral column. The GC-C-IRMS measurements revealed δ-values of -32.5 ± 0.8‰ and -32.3 ± 0.5‰ for (-) α-HCH and (+) α-HCH, respectively. The isotope ratio of bulk α-HCH was estimated to be -32.4 ± 0.6‰ which was in accordance with the δ-values obtained by GC-C-IRMS (-32.7 ± 0.2‰) and elemental analyzer-isotope ratio mass spectrometry (EA-IRMS) of the bulk α-HCH (-32.1 ± 0.1‰). The similarity of the isotope ratio measurements of bulk α-HCH by EA-IRMS and GC-C-IRMS indicates the accuracy of the chiral GC-C-IRMS method. The linearity of the α-HCH ESIA method shows that carbon isotope ratios can be obtained for a signal size above 100 mV. The ESIA measurements exhibited standard deviations (2σ) that were mostly IRMS method, the isotope compositions of individual enantiomers in biodegradation experiments of α-HCH with Clostridium pasteurianum and samples from a contaminated field site were determined. The isotopic compositions of the α-HCH enantiomers show a range of enantiomeric and isotope patterns, suggesting that enantiomeric and isotope fractionation can serve as an indicator for biodegradation and source characterization of α-HCH in the environment. Copyright © 2011 John Wiley & Sons, Ltd.

  6. Stereoisomeric products of electrochemical reduction of heterocyclic Fischer aminocarbene Cr(0) complexes. Development of the electrochemistry-mass spectrometry tandem approach using biphasic (acetonitrile-hexane) preparative electrolysis

    Czech Academy of Sciences Publication Activity Database

    Metelková, R.; Hoskovcová, I.; Polášek, Miroslav; Urban, Jiří; David, T.; Ludvík, Jiří

    2015-01-01

    Roč. 162, APR 2015 (2015), s. 17-23 ISSN 0013-4686 R&D Projects: GA ČR GAP206/11/0727 Institutional support: RVO:61388955 Keywords : Fischer aminocarbene complexes biphasic electrolysis * EC-MS * HPLC-NMR Subject RIV: CG - Electrochemistry Impact factor: 4.803, year: 2015

  7. ArF Excimer Laser-induced Deposition of Ag/C Nanocomposite Thin Films in the Presence of n-Hexane

    Czech Academy of Sciences Publication Activity Database

    Gondal, M.A.; Fajgar, Radek; Chang, X.; Shen, K.; Xu, Q.

    2014-01-01

    Roč. 311, AUG 30 (2014), s. 95-100 ISSN 0169-4332 Grant - others:NNSFCH(CN) 51172044; NSFJP(CN) BK2011617; KFUPM(CN) RG 1311-1 Institutional support: RVO:67985858 Keywords : ArF excimer laser * nanocomposite * laser deposition Subject RIV: CH - Nuclear ; Quantum Chemistry Impact factor: 2.711, year: 2014

  8. Lipase-catalyzed acyl exchange of soybean phosphatidylcholine in n-hexane: a critical evaluation of both acyl incorporation and product recovery

    DEFF Research Database (Denmark)

    Vikbjerg, Anders Falk; Mu, Huiling; Xu, Xuebing

    2005-01-01

    by hydrolysis, which led to the low yields. The biocatalyst used was the commercial immobilized lipase Lipozyme TL IM and substrates used were phosphatidylcholine (PC) from soybean and caprylic acid. A response surface design was used to evaluate the influence of selected parameters and their relationships...

  9. Chemistry of polyhalogenated nitrobutadienes, 10: Synthesis of highly functionalized heterocycles with a rigid 6-amino-3-azabicyclo[3.1.0]hexane moiety

    Directory of Open Access Journals (Sweden)

    Viktor A. Zapol’skii

    2012-04-01

    Full Text Available The nitropolychlorobutadienes 3, 4 are valuable building blocks for various amination and successive heterocyclization products. Nucleophilic substitution reactions of the partially protected, bioactive amines 1, 2 with either vinyl, imidoyl or carbonyl chlorides result in the formation of the enamines 11, 12, 13, 16, 25, the amidine 6, and the amides 20, 21, respectively. In the following, cyclization to the highly functionalized pyrazoles 27, 28, pyrimidine 26 and pyridopyrimidine 24 succeeded. Deprotection of 21, 12 and 28 proved to be only partially feasible.

  10. Experimental determination of the LLE data of systems consisting of {hexane + benzene + deep eutectic solvent} and prediction using the Conductor-like Screening Model for Real Solvents

    NARCIS (Netherlands)

    Rodriguez Rodriguez, Nerea; Gerlach, T.; Scheepers, Daniëlle; Kroon, M.C.; Smirnova, I.

    2017-01-01

    Recently, deep eutectic solvents (DESs) have proven to be excellent extracting agents in the separation of aromatic components from their mixtures with aliphatic compounds. The tunable properties of the DESs allow to tailor-make optimal solvents for this application. In this work type III DESs,

  11. CCDC 1449339: Experimental Crystal Structure Determination : Acetato-(1,3-bis(2,6-bis(pentan-3-yl)phenyl)-2,3-dihydro-1H-imidazol-2-ylidene)-silver(i) n-hexane solvate

    KAUST Repository

    Wong, Valerie H. L.; Vummaleti, Sai V. C.; Cavallo, Luigi; White, Andrew J. P.; Nolan, Steven P.; Hii, King Kuok (Mimi)

    2016-01-01

    An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from

  12. (1R,3R,4R,6S-4-(7-Methoxy-2-oxo-2H-chromen-6-yl-1-methyl-3,6-dioxabicyclo[3.1.0]hexan-2-yl acetate

    Directory of Open Access Journals (Sweden)

    Wong Phakhodee

    2012-12-01

    Full Text Available In the title compound, C17H16O7, which was isolated from the leaves of Micromelum integerrimum, the furan ring adopts an envelope conformation with the O atom as the flap. An intramolecular C—H...O hydrogen bond occurs. The carbonyl O atom is disordered in a 0.57 (8:0.43 (8 ratio. In the crystal, molecules are linked by weak C—H...O hydrogen bonds into a C(10 chain along [010].

  13. CCDC 1449339: Experimental Crystal Structure Determination : Acetato-(1,3-bis(2,6-bis(pentan-3-yl)phenyl)-2,3-dihydro-1H-imidazol-2-ylidene)-silver(i) n-hexane solvate

    KAUST Repository

    Wong, Valerie H. L.

    2016-01-01

    An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

  14. Otimização da esterificação de ácido hexanóico com n-butanol empregando lipase (Termomyces lanuginosus imobilizada em gelatina

    Directory of Open Access Journals (Sweden)

    Everton Skoronski

    2013-01-01

    Full Text Available The application of Lipozyme (Termomyces lanuginosus immobilized in gelatin gel in aliphatic ester synthesis was investigated taking the esterification of hexanoic acid with n-butanol as a model reaction. Conditions were optimized by factorial design and the highest conversion was obtained under the following conditions: molar ratio alcohol: acid of 2:1, reaction time of 48 h and biocatalyst weight of 7.0 g. Under these conditions the esterification yield was around 98 %. The operational stability of the immobilized lipase was assessed and results showed that after 12 batch runs, the enzyme showed no significant loss of activity.

  15. In-situ transesterification of seeds of invasive Chinese tallow trees (Triadica sebifera L.) in a microwave batch system (GREEN(3)) using hexane as co-solvent: Biodiesel production and process optimization.

    Science.gov (United States)

    Barekati-Goudarzi, Mohamad; Boldor, Dorin; Nde, Divine B

    2016-02-01

    In-situ transesterification (simultaneous extraction and transesterification) of Chinese tallow tree seeds into methyl esters using a batch microwave system was investigated in this study. A high degree of oil extraction and efficient conversion of oil to biodiesel were found in the proposed range. The process was further optimized in terms of product yields and conversion rates using Doehlert optimization methodology. Based on the experimental results and statistical analysis, the optimal production yield conditions for this process were determined as: catalyst concentration of 1.74wt.%, solvent ratio about 3 (v/w), reaction time of 20min and temperature of 58.1°C. H(+)NMR was used to calculate reaction conversion. All methyl esters produced using this method met ASTM biodiesel quality specifications. Copyright © 2015 Elsevier Ltd. All rights reserved.

  16. Polymeric Microelectronics.

    Science.gov (United States)

    1981-06-01

    Swelling Procedure For Crosslinked Gel 2A.1 Materials: Spectral grade hexane Petri dish with glass plate cover Planchette Balance Vacuum oven 2A.2...Uncrosslinked Material) To determine the amount of uncrosslinked material decant the dupernatant hexane into a weighed planchette . Wash the gel and...swelling flask or dish with hexane again and pour into planchette . Place the planchette and its contents into a vacuum oven at 350C until the contents

  17. Temperature Dependence of the Inhibition of Positronium by Chlorine- Substituted Hydrocarbons in Non-Polar Liquids

    DEFF Research Database (Denmark)

    Wikander, G.; Mogensen, O.E.; Pedersen, Niels Jørgen

    1984-01-01

    Positron annihilation lifetime spectra were measured for solutions of 1,2,3,5-C6H2Cl4 in hexane, toluene, m-xylene and mesitylene, CCl4 in hexane and toluene, and C2HCl3 in n-hexane for concentrations below 1 M and at various temperatures between −30°C and 67°C. The Ps inhibition by C6H2Cl4 was r...

  18. JCSC_128_11_1703_1707_SI_a.docx

    Indian Academy of Sciences (India)

    dell

    Finally, the reaction was neutralized by triethyl ammine and the solution passed through a small basic alumina column. The reaction mixture was concentrated and 8 was separated by silica gel column chromatography using DCM/Hexane as eluent. 8 was crystallised with DCM/Hexane system. [8]2+ was generated by ...

  19. Reducing post-harvest losses in South Asia's mango orchards ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    2016-04-29

    Apr 29, 2016 ... Spraying a small concentration of hexanal in mango orchards has been found to delay the ripening of the fruit by an extra three weeks, enabling farmers to earn up to 15% more for their crop. Once the crop is harvested, hexanal-sprayed mangoes also have a much longer shelf life—up to 26 days in cold ...

  20. Aktivitas Salep Ekstrak Rimpang Kunyit dalam Proses Persembuhan Luka pada Mencit yang Diinduksi Diabetes (THE ACTIVITY OF TURMERIC EXTRACT OINTMENT IN THE WOUND HEALING PROCESS OF INDUCED DIABETIC MICE

    Directory of Open Access Journals (Sweden)

    Wiwin Winarsih

    2013-07-01

    Full Text Available The aim of this study was to evaluate the effectiveness of ethanol turmeric extract ointment in woundhealing process of streptozotocin-induced diabetic mice. Ethyl acetate and hexane fractions of ethanolturmeric extract were studied for their wound-healing properties in the formulation of ointment. Sixty micewere divided into 4 groups : group I was control (normal control, without treatment; group II was diabeticgroup (diabetic, without treatment; group III was diabetic and treated with ethyl acetate fraction ointment,group IV was diabetic and treated with hexane fraction ointment. The diabetic groups were i.p injectedwith 40mg/kg of streptozotocin and all groups were received incision 2 cm on their back skin. The ointmentsof ethyl acetate and hexane fraction were given topically twice a day. Three mice from each groups werenecropsied at 2nd, 4th, 7th, 14th and 21st days post incision (pi for gross pathological and histopathologicalevaluation of the injured skin. Gross examination revealed that the ethyl acetate and hexane fractionointment groups showed better result on wound-healing process compared to the diabetic group.Microscopically, the ethyl acetate and hexane fraction ointment groups showed faster neovascularizationand reepithelialization compared to the diabetic group. In comparison with the diabetic group, the ethylacetate and hexane fraction ointment groups showed fewer neutrophils infiltration which indicated antiinflammatory activities of ethyl acetate and hexane fractions. Based on the macroscopic and microscopicobservation, the ointments of ethyl acetate and hexane fraction have properties to promote wound healingin diabetic mice.

  1. Fulltext PDF

    Indian Academy of Sciences (India)

    (PPARs) agonists in particular in the management of hyperglycemia and hyperlipidaemia for the treatment of. Type 2 Diabetes (T2D). We have .... under reduced pressure to give a residue which upon trituration with hexane or upon column chromatography (hexane/EtOAc, 1:5) gave the desired compound as a solid.

  2. Physicochemical and microbiological characterization of linolenic ...

    African Journals Online (AJOL)

    SWEET

    2012-05-15

    May 15, 2012 ... absorbance of hexanic oil solution (1%) by using a UV-Vis .... two fairly stacking graphs with maximum absorbances at. 220 and 280 nm ... extracted oilseeds of the two plants were fungus, ... triplicate by measuring absorbances of hexanic oilseeds (1%) in the wavelengths range varying from 200 to 600 nm.

  3. Biological activities of Rumex dentatus L: Evaluation of methanol ...

    African Journals Online (AJOL)

    The methanol extracts of leaf and stem inhibited radish seed germination (70 and 61% respectively) and root length more than the hexane extracts. The R. dentatus methanol extract showed presence of alkaloids, saponins, anthraquinones and tannins while flavonoids were also found in both methanol as well as hexane ...

  4. LIPID METHODOLOGY AND POLLUTANT NORMALIZATION RELATIONSHIPS FOR NEUTRAL NONPOLAR ORGANIC POLLUTANTS

    Science.gov (United States)

    This work compares the ability of hexane and chloroform with methanol (C/M) to extract lipid, polychlorinated biphenyls (PCBs), and p,p'-DDE from white croaker (Geneonus lineatus) muscle tissue. Hexane extracted on average 25% of the lipid and 73% of the PCB congeners that were e...

  5. Estimating dermal transfer from PCB-contaminated porous surfaces.

    Science.gov (United States)

    Slayton, T M; Valberg, P A; Wait, A D

    1998-06-01

    Health risks posed by dermal contact with PCB-contaminated porous surfaces have not been directly demonstrated and are difficult to estimate indirectly. Surface contamination by organic compounds is commonly assessed by collecting wipe samples with hexane as the solvent. However, for porous surfaces, hexane wipe characterization is of limited direct use when estimating potential human exposure. Particularly for porous surfaces, the relationship between the amount of organic material collected by hexane and the amount actually picked up by, for example, a person's hand touch is unknown. To better mimic PCB pickup by casual hand contact with contaminated concrete surfaces, we used alternate solvents and wipe application methods that more closely mimic casual dermal contact. Our sampling results were compared to PCB pickup using hexane-wetted wipes and the standard rubbing protocol. Dry and oil-wetted samples, applied without rubbing, picked up less than 1% of the PCBs picked up by the standard hexane procedure; with rubbing, they picked up about 2%. Without rubbing, saline-wetted wipes picked up 2.5%; with rubbing, they picked up about 12%. While the nature of dermal contact with a contaminated surface cannot be perfectly reproduced with a wipe sample, our results with alternate wiping solvents and rubbing methods more closely mimic hand contact than the standard hexane wipe protocol. The relative pickup estimates presented in this paper can be used in conjunction with site-specific PCB hexane wipe results to estimate dermal pickup rates at sites with PCB-contaminated concrete.

  6. Molecular simulation of CO chemisorption on Co(0001) in presence of supercritical fluid solvent: A potential of mean force study

    Energy Technology Data Exchange (ETDEWEB)

    Asiaee, Alireza; Benjamin, Kenneth M., E-mail: kenneth.benjamin@sdsmt.edu [Department of Chemical and Biological Engineering, South Dakota School of Mines and Technology, 501 E. Saint Joseph St., Rapid City, South Dakota 57701 (United States)

    2016-08-28

    For several decades, heterogeneous catalytic processes have been improved through utilizing supercritical fluids (SCFs) as solvents. While numerous experimental studies have been established across a range of chemistries, such as oxidation, pyrolysis, amination, and Fischer-Tropsch synthesis, still there is little fundamental, molecular-level information regarding the role of the SCF on elementary heterogeneous catalytic steps. In this study, the influence of hexane solvent on the adsorption of carbon monoxide on Co(0001), as the first step in the reaction mechanism of many processes involving syngas conversion, is probed. Simulations are performed at various bulk hexane densities, ranging from ideal gas conditions (no SCF hexane) to various near- and super-critical hexane densities. For this purpose, both density functional theory and molecular dynamics simulations are employed to determine the adsorption energy and free energy change during CO chemisorption. Potential of mean force calculations, utilizing umbrella sampling and the weighted histogram analysis method, provide the first commentary on SCF solvent effects on the energetic aspects of the chemisorption process. Simulation results indicate an enhanced stability of CO adsorption on the catalyst surface in the presence of supercritical hexane within the reduced pressure range of 1.0–1.5 at a constant temperature of 523 K. Furthermore, it is shown that the maximum stability of CO in the adsorbed state as a function of supercritical hexane density at 523 K nearly coincides with the maximum isothermal compressibility of bulk hexane at this temperature.

  7. IDENTIFICATION OF THE ISOLATED COMPOUNDS FROM Zingiber amaricans BL. RHIZOME

    Directory of Open Access Journals (Sweden)

    Sugeng Riyanto

    2010-06-01

    Full Text Available Five extracts were obtained from extraction of rhizomes of Zingiber amaricans. Hexane, dichloromethane and methanol extracts were obtained by maceration, while dichloromethane and acetone extracts the resulted of soxhlet extraction. By column chromatography technique 2,6,9-humulantrien-9-one (zerumbone was isolated as the major constituent of the hexane, dichloromethane and methanol extracts. The minor constituents were phytosterol mixtures isolated from hexane and dichloromethane extracts. The mixtures consisted cholesterol, campesterol, stigmasterol and b-sitosterol. The structure elucidations of zerumbone was confirmed by spectroscopic method, whereas the phytosterol mixtures was identified by gas chromatography-mass.   Keywords: zerumbone, phytosterol, zingiber amaricans, spectroscopy

  8. Volatile and non-volatile compounds and antimicrobial activity of Mansoa difficilis (Cham.) Bureau and K. Schum. (Bignoniaceae)

    International Nuclear Information System (INIS)

    Guilhon, Giselle Maria Skelding Pinheiro; Silva, Elisangela Sarmento da; Santos, Lourivaldo da Silva; Uetanabaro, Ana Paula Trovatti

    2012-01-01

    Essential oil from the leaves of Mansoa difficilis was analyzed by GC/MS. Oct-1-en-3-ol (49.65%) was the major compound, but diallyl di- and trisulfide were also present (0.85 and 0.37%, respectively), justifying the garlic-like odor of the crushed leaves. The hexane and methanol extracts of the leaves and stems afforded as main constituents a mixture of linear hydrocarbons, spinasterol, stigmasterol, ursolic and oleanolic acids, two apigenin derivatives and verbascoside. The hexane and methanol extracts of leaves were tested for antimicrobial activity against ten microorganisms. The hexane extract was active against both Pseudomonas aeruginosa and Staphylococcus aureus. (author)

  9. Volatile and non-volatile compounds and antimicrobial activity of Mansoa difficilis (Cham.) Bureau and K. Schum. (Bignoniaceae)

    Energy Technology Data Exchange (ETDEWEB)

    Guilhon, Giselle Maria Skelding Pinheiro; Silva, Elisangela Sarmento da; Santos, Lourivaldo da Silva [Universidade Federal do Para (UFPA), Belem, PA (Brazil). Fac. de Quimica; Zoghbi, Maria das Gracas Bichara [Museu Paraense Emilio Goeldi, Belem, PA (Brazil). Coordenacao de Botanica; Araujo, Isabella Santos [Universidade Estadual de Feira de Santana (UEFS), Feira de Santana, BA (Brazil); Uetanabaro, Ana Paula Trovatti, E-mail: giselle@ufpa.br [Universidade Estadual de Santa Cruz (UESC), Ilheus, BA (Brazil)

    2012-07-01

    Essential oil from the leaves of Mansoa difficilis was analyzed by GC/MS. Oct-1-en-3-ol (49.65%) was the major compound, but diallyl di- and trisulfide were also present (0.85 and 0.37%, respectively), justifying the garlic-like odor of the crushed leaves. The hexane and methanol extracts of the leaves and stems afforded as main constituents a mixture of linear hydrocarbons, spinasterol, stigmasterol, ursolic and oleanolic acids, two apigenin derivatives and verbascoside. The hexane and methanol extracts of leaves were tested for antimicrobial activity against ten microorganisms. The hexane extract was active against both Pseudomonas aeruginosa and Staphylococcus aureus. (author)

  10. Phytochemical screening of different extracts of Kalanchoe laciniata

    Directory of Open Access Journals (Sweden)

    Maria Manan

    2015-06-01

    Full Text Available Alkaloids, tannins, saponins, steroids, terpenoids and flavonoids distribution in n-hexane and aqueous-methanolicextract of kalanchoelaciniata was assessed and compared. The present study was carried out to study the phytochemical constituents of Kalanchoe laciniata. Aqueous-methanol and n-hexane were the solvents used for the extraction of the plant. Phytochemical analysis was carried out on both of these extracts, indicated that n-hexane extract constitutes tannins, terpenoids on the other hand aqueous-methanolic extract contains saponins, tannins, terpenoids, flavonoids, glycosides  and anthraquinones. 

  11. THERMODYNAMIC PARAMETERS OF SOLUTIONS OF ...

    African Journals Online (AJOL)

    2014-06-30

    Jun 30, 2014 ... Physical Chemistry Laboratory, Department of Chemistry, ... The solubility of Sildenafil citrate in some organic solvents; hexane, ... dichloroethane were analytical grade reagents, which were purified by fractional distillation.

  12. Rate Constants for the Reactions of Hydroxyl Radical with Several Alkanes, Cycloalkanes, and Dimethyl Ether

    Science.gov (United States)

    DeMore, W.; Bayes, K.

    1998-01-01

    Relative rate experiements were used to measure rate constants and temperature denpendencies of the reactions of OH with propane, n-butane, n-pentane, n-hexane, cyclopropane, cyclobutane, cyclopentane, and dimethyl ether.

  13. The effects of Kaempferia parviflora on anti- internalization activity of ...

    African Journals Online (AJOL)

    USER

    2010-07-26

    Jul 26, 2010 ... study, four parts of Kaempferia parviflora's extracts composing of volatile oil, hexane, ethyl acetate ... tissue lymphoma (MALT) (Graham, 1997; Raus et al., .... mented with 10% (v/v) fetal bovine serum and 1% (v/v) antibiotic-.

  14. (Vapour + liquid) equilibria of ternary systems with ionic liquids using headspace gas chromatography

    International Nuclear Information System (INIS)

    Mokhtarani, Babak; Gmehling, Juergen

    2010-01-01

    (Vapour + liquid) equilibrium (VLE) data for the ternary systems (hexane + benzene), (hexane + cyclohexane), (benzene + cyclohexane), and (ethanol + water) with an ionic liquid as entrainer for extractive distillation were measured by headspace gas chromatography. As ionic liquids, 1-hexyl-3-methyl-imidazolium bis (trifluoromethyl-sulfonyl) imide [HMIM][BTI], 1-octyl-3-methyl-imidazolium bis (trifluoromethyl-sulfonyl) imide [OMIM][BTI], 1-octyl-3-methyl-imidazolium trifluoro-methanesulfonate [OMIM][OTF], and 1-butyl-3-methyl-imidazolium trifluoro-methanesulfonate [BMIM][OTF] were used. The experimental data show that the ionic liquids investigated have a great influence on the separation factors of the systems (hexane + benzene), (hexane + cyclohexane), and (benzene + cyclohexane). The experimental data were compared with the predicted results using mod. UNIFAC (Do). The predicted results are in good agreement with the experimental data.

  15. Biomarkers derived from heterolytic and homolytic cleavage of allylic hydroperoxides resulting from alkenone autoxidation

    Digital Repository Service at National Institute of Oceanography (India)

    Rontania, J.F.; Harji, R.; Volkmanc, J.K.

    Laboratory incubation of alkenone mixtures with tert-butyl hydroperoxide and di-tert-butyl nitroxide (radical initiator) in hexane, as a means to simulate alkenone autoxidation processes, rapidly led to the formation of allylic hydroperoxides, whose...

  16. Evaluation of antioxidant and cytotoxic properties of Cynobacteria, Limnothrix sp. and Leptolyngbya sp. from Arabian sea

    Digital Repository Service at National Institute of Oceanography (India)

    Anas, A.; Vinothkumar, S.; Gupta, S.; Jasmin, C.; Joseph, V.; Parameswaran, P.S.; Nair, S.

    The hexane fractions of the marine cyanobacteria: Leptolyngbya sp. and Limnothrix sp., collected from Arabian Sea were found to display promising antioxidant properties than their ethyl acetate fraction during radical scavenging ABTS/DPPH assays (IC...

  17. Solvent-driven symmetry of self-assembled nanocrystal superlattices-A computational study

    KAUST Repository

    Kaushik, Ananth P.; Clancy, Paulette

    2012-01-01

    used solvents, toluene and hexane. System sizes in the 400,000-500,000-atom scale followed for nanoseconds are required for this computationally intensive study. The key questions addressed here concern the thermodynamic stability of the superlattice

  18. Improved extraction procedure for carotenoids from human milk.

    Science.gov (United States)

    Schweigert, F J; Hurtienne, A; Bathe, K

    2000-05-01

    An improved method for the extraction of the major carotenoids from human milk is described. Carotenoids were extracted from milk first with ethanol and n-hexane. Then, polar xanthophylls were extracted from n-hexane into ethanol/water. The remaining n-hexane was evaporated, the residue combined with the ethanolic milk fraction and the mixture briefly saponified. Carotenoids were extracted from the hydrolysate with n-hexane, combined with the polar xanthophylls from the non-saponified ethanol/water-extract and separated by HPLC. Using this method we were able to significantly improve the recovery of xanthophylls such as lutein and zeaxanthin from human milk. The recovery rate of all carotenoids was > 90%. This method might not only be of value for milk but should be especially useful in the extraction of carotenoids from human tissues such as the adipose tissue.

  19. Compendium of shock wave data. Introduction. Section A1. Elements

    International Nuclear Information System (INIS)

    van Thiel, M.; Shaner, J.; Salinas, E.

    1977-06-01

    This volume lists thermodynamic data for inorganic compounds and hydrocarbons. Binary and more complex compounds (including minerals) are listed; among the hydrocarbons are anthracene, benzene, hexane, paraffin, polyethylene, and polystyrene

  20. Inhibition of Quorum Sensing-Controlled Virulence Factor Production in Pseudomonas aeruginosa PAO1 by Ayurveda Spice Clove (Syzygium Aromaticum Bud Extract

    Directory of Open Access Journals (Sweden)

    Kok-Gan Chan

    2012-03-01

    Full Text Available Quorum sensing controls the virulence determinants in most proteobacteria. In this work, the hexane, chloroform and methanol extracts of an Ayurveda spice, namely clove (Syzygium aromaticum, shown anti-quorum sensing activity. Hexane and methanol extracts of clove inhibited the response of C. violaceum CV026 to exogenously supplied N‑hexanoylhomoserine lactone, in turn preventing violacein production. Chloroform and methanol extracts of clove significantly reduced bioluminescence production by E. coli [pSB1075] grown in the presence of N-(3-oxododecanoyl-L-homoserine lactone. We demonstrated that clove extract inhibited quorum sensing-regulated phenotypes in Pseudomonas aeruginosa PA01, including expression of lecA::lux (by hexane extract, swarming (maximum inhibition by methanol extract, pyocyanin (maximum inhibition by hexane extract. This study shows that the presence of natural compounds that exhibit anti-quorum sensing activity in the clove extracts may be useful as the lead of anti-infective drugs.

  1. Texting to save lives in South Asia | IDRC - International ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    2012-05-30

    May 30, 2012 ... Imagine a world where mobile technology helps to save lives by quickly alerting ... tested a system using mobile phones in an IDRC-supported pilot study. ... team is developing nanotechnology-based applications of hexanal, ...

  2. (Vapour + liquid) equilibria of ternary systems with ionic liquids using headspace gas chromatography

    Energy Technology Data Exchange (ETDEWEB)

    Mokhtarani, Babak [Chemistry and Chemical Engineering Research Center of Iran, P.O. Box 14335-186, Tehran (Iran, Islamic Republic of); Gmehling, Juergen, E-mail: gmehling@tech.chem.uni-oldenburg.d [Carl von Ossietzky Universitaet Oldenburg, Technische Chemie, D-26111 Oldenburg (Germany)

    2010-08-15

    (Vapour + liquid) equilibrium (VLE) data for the ternary systems (hexane + benzene), (hexane + cyclohexane), (benzene + cyclohexane), and (ethanol + water) with an ionic liquid as entrainer for extractive distillation were measured by headspace gas chromatography. As ionic liquids, 1-hexyl-3-methyl-imidazolium bis (trifluoromethyl-sulfonyl) imide [HMIM][BTI], 1-octyl-3-methyl-imidazolium bis (trifluoromethyl-sulfonyl) imide [OMIM][BTI], 1-octyl-3-methyl-imidazolium trifluoro-methanesulfonate [OMIM][OTF], and 1-butyl-3-methyl-imidazolium trifluoro-methanesulfonate [BMIM][OTF] were used. The experimental data show that the ionic liquids investigated have a great influence on the separation factors of the systems (hexane + benzene), (hexane + cyclohexane), and (benzene + cyclohexane). The experimental data were compared with the predicted results using mod. UNIFAC (Do). The predicted results are in good agreement with the experimental data.

  3. 77 FR 20334 - Receipt of Several Pesticide Petitions Filed for Residues of Pesticide Chemicals in or on Various...

    Science.gov (United States)

    2012-04-04

    ... exhaustive, but rather provides a guide for readers regarding entities likely to be affected by this action... digested with acid. The hydrolyzed metabolites are then extracted with a mixture of hexane and ether, and...

  4. Determination of acrylamide levels in selected commercial and ...

    African Journals Online (AJOL)

    Tropical Journal of Pharmaceutical Research ... Food samples were defatted by hexane and then extracted with methanol 98 % in a ... Results: Among the commercial foods tested, the highest acrylamide quantity was found in potato products ...

  5. Avaliação dos parâmetros de solubilidade de Hildebrand/Hansen na seleção de solventes para a extração de pesticidas organoclorados do solo

    Directory of Open Access Journals (Sweden)

    Ricardo D Villa

    2011-09-01

    Full Text Available This work evaluated the use of the Hildebrand/Hansen solubility parameters for selection of solvents for extraction of the organochlorine pesticides pp' DDT, pp' DDE, Aldrin and a-Endossulfan from soil using columns packed with Al2O3. The mixtures hexane:dichloromethane (7:3; v/v, hexane:acetonitrile (1:1; v/v, hexane:acetone (1:1; v/v and pure hexane were chosen as extracting solutions. In the addition and recovery tests, different extraction solutions provided high recoveries percentages (>75% with coefficients of variation below 15%. The recoveries are in agreement with the Hildebrand/Hansen parameters, demonstrating its applicability in the selection of extracting solution and in the replacement of toxic solvents, as dichloromethane

  6. Selective Methods for C-X Activation in Carbohydrates

    Science.gov (United States)

    2013-01-01

    system, the major products observed for the hydrosilylation of monosaccharides were n-hexane, 2- and 3-methylpentane. Glucose hydrosilylation could... polysaccharide cellulose reacting faster than unprotected glucose. Complete hydrosilylation of methyl cellulose yielded a similar mixture of alkane products

  7. Susceptibility of Aedes aegypti pupae to neem seed kernal extracts ...

    African Journals Online (AJOL)

    Azadirachta indica) seed kernel extracts (NSKE) on Aedes aegypti. The neem seed kernel powder was sequentially extracted with hexane, benzene, ethyl acetate, acetone, DMSO, 2-propanol, ethanol, methanol and dstiledwater.

  8. Application of lipid peroxidation and protein oxidation biomarkers for oxidative damage in mammalian cells. A comparison with two fluorescent probes

    NARCIS (Netherlands)

    Orhan, H.; Gurer-Orhan, H.; Vriese, E.; Vermeulen, N.P.E.; Meerman, J.H.N.

    2006-01-01

    We recently developed two biomarker sets for oxidative damage: one for determination of lipid peroxidation (LPO) degradation products; acetaldehyde, propanal, butanal, pentanal, hexanal, heptanal, octanal, nonanal, malondialdehyde and acetone, by a gas chromatography-electron capture detection

  9. Download this PDF file

    African Journals Online (AJOL)

    RAGHAVENDRA

    Science, Technology and Arts Research Journ. Sci. Technol. .... are listed in Table 1. Figure 1: Total ion chromatogram (TIC) of Asparagus racemosus root hexane fraction .... advances in biologically active compounds in herbs and spices: A ...

  10. Preparation and characterization of monosubstituted porphyrins ...

    Indian Academy of Sciences (India)

    Administrator

    phyrins in both synthetic chemistry and industrial process heavily. These shortcomings ... and environmental pro- blem, due to their wide production and use as explosives ... distilled under nitrogen atmosphere before use. Hexane was distilled ...

  11. Phytochemical and biological characterization of Periploca aphyla ...

    African Journals Online (AJOL)

    Dr.R Ali Khan

    2012-07-10

    Jul 10, 2012 ... quantity of flavonoids in methanolic extract of P. hysterophorus which turned down gradually in n- hexane extract ... Sample Flavonoids Alkaloids Terpenoids Coumarins Saponins ... Science and Technology Bannu, Pakistan.

  12. Analgesic and Anti-Inflammatory Activities of an Ethanol Extract of ...

    African Journals Online (AJOL)

    Samuel Olaleye

    (nociception) induced by acetic acid, formalin and hot plate. ... in hexane, chloroform, ethyl acetate and methanol. Each aqueous ... (Unfailing Veterinary Service, Uyo, Nigeria) and water ..... neurokinin A and vasoactive intestinal peptide, which.

  13. Preparation of dual-sensitive graft copolymer hydrogel based on N ...

    Indian Academy of Sciences (India)

    Administrator

    Organic solvent-soluble N-maleoyl-chitosan (NMCS) was synthesized by reaction of ... provement or modification of polymer materials through ... the mixture of hexane and toluene. ... reacted solution was cooled to room temperature and.

  14. Application of marker-assisted selection for ahFAD2A and ahFAD2B ...

    African Journals Online (AJOL)

    PretoriusAE

    2009-09-15

    ). ... was extracted from 10 g ground kernels, dissolved in hexane and centrifuged to ... 10 min at 85°C and then cooled to room temperature. 1 ml of 14% ... backcrosses was done using the polymeric triglyceride exclusion.

  15. Biochemical Properties, In-Vitro Antimicrobial, and Free Radical ...

    African Journals Online (AJOL)

    ADOWIE PERE

    hexane, ethyl acetate and methanol extracts of the plant principally revealed the presence of ... protein, fiber, fat, carbohydrate and ash contents in ... The animals were given standard rat pellets .... and fats & oil as shown in table 1 below. The.

  16. Artificial Neural Network Analysis of Xinhui Pericarpium Citri ...

    African Journals Online (AJOL)

    Methods: Artificial neural networks (ANN) models, including general regression neural network (GRNN) and multi-layer ... N-hexane (HPLC grade) was purchased from. Fisher Scientific. ..... Simultaneous Quantification of Seven Flavonoids in.

  17. Antibacterial activity and medicinal properties of ginger ( Zingiber ...

    African Journals Online (AJOL)

    . Ginger extracts were obtained using solvents, n-hexane, ethyl acetate, ethanolic soxhlet and water. The extracts were assayed for antibacterial activity and bacterial growth inhibition activity. The results showed that all the extracts except the ...

  18. What we do | Page 179 | IDRC - International Development ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    As part of an experimental project, Indian farmers spray mango trees with a hexanal- ... II (Malika) on Human Health using an Ecohealth Approach (Sénégal) ... play in the implementation of development activities that fall to local communities.

  19. A novel thiourea-based non-ionic surfacta

    Indian Academy of Sciences (India)

    millimolar critical micelle concentration (CMC) in ethanol and hexane, demonstrating that this is moderately amphiphobic. .... the compound in ethanol at room temperature is pre- sented in figure 1. .... nism for the electro-oxidation. The peak ...

  20. Synthesis and stereochemistry of 8.0.4' type neolignanes with a problable antileukemia activity

    International Nuclear Information System (INIS)

    Braga, A.C.H.; Barata, L.E.S.; Ruveda, E.A.

    The hexane extract from Virola surinameris leaves leads to isolate several compounds such as 8.0.4' type neolignanes surinamensine and viroline. Physical methods such as UV, IV, MS, etc are usec. (A.R.H.) [pt

  1. Combinatorial Analysis of Functional Interfaces and Surfaces Generated Via Dip-Pen Nanolithography

    National Research Council Canada - National Science Library

    Higgins, Thomas B

    2006-01-01

    .... Various chemical compounds spanning a range of hydrophobicities and meniscus solubilities were used as inks in DPN and deposited in a variety of solvent atmospheres such as ethanol, methanol, hexanes...

  2. Biodiesel production from wet municipal sludge: evaluation of in situ transesterification using xylene as a cosolvent.

    Science.gov (United States)

    Choi, O K; Song, J S; Cha, D K; Lee, J W

    2014-08-01

    This study proposes a method to produce biodiesel from wet wastewater sludge. Xylene was used as an alternative cosolvent to hexane for transesterification in order to enhance the biodiesel yield from wet wastewater sludge. The water present in the sludge could be separated during transesterification by employing xylene, which has a higher boiling point than water. Xylene enhanced the biodiesel yield up to 8.12%, which was 2.5 times higher than hexane. It was comparable to the maximum biodiesel yield of 9.68% obtained from dried sludge. Xylene could reduce either the reaction time or methanol consumption, when compared to hexane for a similar yield. The fatty acid methyl esters (FAMEs) content of the biodiesel increased approximately two fold by changing the cosolvent from hexane to xylene. The transesterification method using xylene as a cosolvent can be applied effectively and economically for biodiesel recovery from wet wastewater sludge without drying process. Copyright © 2014 Elsevier Ltd. All rights reserved.

  3. Solvent and electronic effects on kinetics of cyclization of thermolabile aryllithium reagents. A comparison between 1-bromo-2-(2-bromoethylbenzene and 4,5-dimethoxy-1-bromo-2-(2-bromoethylbenzene

    Directory of Open Access Journals (Sweden)

    David A. Hunt

    2009-05-01

    Full Text Available A dramatic solvent effect on the stability and kinetics of intramolecular cyclization is described for the aryllithium species generated from 2-bromo-4,5-dimethoxy-(2-bromoethylbenzene. The aryllithium generated by the halogen-metal exchange reaction with n-butyllithium, is stable for > 1h when generated at -95 to -100 oC in diethyl ether/hexane and can be trapped with electrophiles. However, when the reaction is conducted in a THF/hexane mixture, the intermediate undergoes instantaneous intramolecular cyclization to afford 4,5-dimethoxybenzocyclobutene. By comparison, the corresponding 1-lithio-2-(2-bromoethyl-benzene intermediate is stable for >1h in either THF/hexane or diethyl ether/hexane at -95 to -100 oC. These results indicate that substituent effects as well as the nature of aggregation of these intermediates play key roles in determining the reaction pathway of functionalized aryllithium intermediates when quenched with electrophiles.

  4. Environ: E00537 [KEGG MEDICUS

    Lifescience Database Archive (English)

    Full Text Available PD:C00249], Oleic acid [CPD:C00712], trans-2-Decenal, Octenal, Hexanal Aspongopus chinensis, Aspongopus [TAX:236666], Nezara... antennata, Nezara [TAX:85309] ... Pentatomidae Aspongopus chinensis (dried) Others: Pentatomidae Nezara antennata (dried) ...

  5. 53-64 Page 53 JOPAT Vol. 15(1)

    African Journals Online (AJOL)

    Christy

    Thin layer chromatography of the hexane extract showed 11 spots one ... blood, strengthening and consolidation of lungs, as well as the treatment of pus, ... Additional medical applications of the boiled and/or dried tubers include treatment of.

  6. Antioxidant, antimicrobial, antitumor, and cytotoxic activities of an important medicinal plant (Euphorbia royleana from Pakistan

    Directory of Open Access Journals (Sweden)

    Aisha Ashraf

    2015-03-01

    Full Text Available The aim of present study was to evaluate antioxidant, antimicrobial, and antitumor activities of methanol, hexane, and aqueous extracts of fresh Euphorbia royleana. Total phenolic and flavonoid contents were estimated as gallic acid and querectin equivalents, respectively. Antioxidant activity was assessed by scavenging of free 2,2′- diphenyl-1-picrylhydrazyl radicals and reduction of ferric ions, and it was observed that inhibition values increase linearly with increase in concentration of extract. The results of ferric reducing antioxidant power assay showed that hexane extract has maximum ferric reducing power (12.70 ± 0.49 mg gallic acid equivalents/g of plant extract. Maximum phenolic (47.47 ± 0.71 μg gallic acid equivalents/mg of plant extract and flavonoid (63.68 ± 0.43 μg querectin equivalents/mg of plant extract contents were also found in the hexane extract. Furthermore, we examined antimicrobial activity of the three extracts (methanol, hexane, aqueous against a panel of microorganisms (Escherichia coli, Bacillus subtillis, Pasteurella multocida, Aspergillus niger, and Fusarium solani by disc-diffusion assay, and found the hexane extract to be the best antimicrobial agent. Hexane extract was also observed as to be most effective in a potato disc assay. As hexane extract showed potent activity in all the investigated assays, it was targeted for cytotoxic assessment. Maximum cytotoxicity (61.66% by hexane extract was found at 800 μg/mL. It is concluded that investigated extracts have potential for isolation of antioxidant and antimicrobial compounds for the pharmaceutical industry.

  7. Efficacy of Odor Scavengers in Reducing Odor Compounds in Water, Milk, and Soymilk

    OpenAIRE

    Norton, Jenny Lynn

    2003-01-01

    Odor detection thresholds of hexanal, 2-heptenal, 2-pentanone, and 2,4-nonadienal were determined in spring water, high temperature short time (HTST) 2% fat milk, and extended shelf life soymilk. The efficacy of odor scavenger's beta-cyclodextrin, D-sorbitol, and nylon 6 in removing these odors was also determined. The odor thresholds of the different odor and media combinations were as follows: hexanal in spring water, milk, and soymilk were 585, 339, and 536 ppb respectively; 2-heptenal ...

  8. Applications of Laser Diagnostics

    Science.gov (United States)

    2005-03-01

    fraction of methane in the fuel is 0.48. The steady nozzle velocities of the fuel and oxyder stream are respectively 0.59 m/s and 0.61 m/s. The...Hexane Heptane Toluene Benzene THF Ethyl acetate Chloroform Dichloromethane Acetone DMSO Propylene carbonate Benzyl alcohol Ethanol Methanol Octanol...Cyclohexane Pentane Hexane Heptane Toluene Benzene THF Ethyl acetate Chloroform Dichloromethane Acetone DMSO Propylene carbonate Benzyl alcohol Ethanol

  9. Fabrication and characterization of nanocomposites reinforced by carbon nanotubes - (1) synthesis of carbon nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Hseuh Hsiangming; Tai Nyanhwa; Perng Tongping [Dept. of Material Science, National Tsing-Hwa Univ., TW (China); Chyou Sander [Taiwan Power Research Inst., Taiwan Power Co., Taipei (China)

    2003-07-01

    Multi-walled carbon nanotubes (MWCNTs) produced by floating catalyst method were used for reinforcing material in polymeric nanocomposites. Five different kinds of carbon sources (benzene, toluene, xylene, cyclo-hexane, n-hexane) were used as precursors in the thermal chemical vapor deposition process. The products were collected and examined by Raman, HRTEM, and FESEM. The differences in microstructure and morphologies among these products are analyzed and discussed. (orig.)

  10. Antioxidant activity of Vitex agnus-castus L. extracts.

    Science.gov (United States)

    Sağlam, Hüsniye; Pabuçcuoğlu, Aysun; Kivçak, Bijen

    2007-11-01

    The ethanol, n-hexane and water extracts of Vitex agnus-castus L. leaves and fruits were screened for antioxidant activity. The antioxidant activity of plant extracts was determined by an improved assay based on the decolorization of the radical monocation of 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS.+). The water and ethanol extracts showed stronger antioxidant activity than the n-hexane extracts. Copyright (c) 2007 John Wiley & Sons, Ltd.

  11. Comparative study of the active sites in zeolites by different probe molecules

    Directory of Open Access Journals (Sweden)

    ALINE AUROUX

    2005-03-01

    Full Text Available This review summarizes some of the recently published results concerning the acid sites in the zeolites ZSM-5 and Y studied by temperature-programmed desorption (TPD and adsorption calorimetry using different probe molecules NH3, CO, N2O and n-hexane. For the first time it has been shown that the acid sites in hydrated zeolites are accessible for n-hexane adsorption

  12. New Technology for Oil/Water Emulsion Treatment: Phases I and II

    Science.gov (United States)

    1998-05-15

    demand (COD) IV-16 by EPA Method 410.4, and the quantity of filterable solids (QFS) by gravimetry . A field laboratory for the analysis of O&G and QFS...This method measures n-hexane extractable material (HEM) and silica-gel- treated hexane extractable material (SGT-HEM) by extraction and gravimetry ...collection vial • Routine formations of a precipitate when the method-recommended spiking standard, a mixture of hexadecane and stearic acid in

  13. [Oxidation behavior and kinetics of representative VOCs emitted from petrochemical industry over CuCeOx composite oxides].

    Science.gov (United States)

    Chen, Chang-Wei; Yu, Yan-Ke; Chen, Jin-Sheng; He, Chi

    2013-12-01

    CuCeOx composite catalysts were synthesized via coprecipitation (COP-CuCeO,) and incipient impregnation (IMP-CuCeOx) methods, respectively. The physicochemical properties of the samples were characterized by XRD, low-temperature N2 sorption, H2-TPR and O2-TPD. The influences of reactant composition and concentration, reaction space velocity, O2 content, H2O concentration, and catalyst type on the oxidation behaviors of benzene, toluene, and n-hexane emitted from petrochemical industry were systematically investigated. In addition, the related kinetic parameters were model fitted. Compared with IMP-CuCeOx, COP-CuCeOx had well-dispersed active phase, better low-temperature reducibility, and more active surface oxygen species. The increase of reactant concentration was unfavorable for toluene oxidation, while the opposite phenomenon could be observed in n-hexane oxidation. The inlet concentration of benzene was irrelevant to its conversion under high oxidation rate. The introduction of benzene obviously inhibited the oxidation of toluene and n-hexane, while the presence of toluene had a positive effect on beuzene conversion. The presence of n-hexane could promote the oxidation of toluene, while toluene had a negative influence on e-hexane oxidation. Both low space velocity and high oxygen concentration were beneficial for the oxidation process, and the variation of oxygen content had negligible effect on n-hexane and henzene oxidation. The presence of H2O noticeably inhibited the oxidation of toluene, while significantly accelerated the oxidation procedure of henzene and n-hexane. COP-CuCeOx had superior catalytic performance for toluene and benzene oxidation, while IMP-CuCeOx showed higher n-hexane oxidation activity under dry condition. The oxidation behaviors under different conditions could be well fitted and predicted by the pseudo first-order kinetic model.

  14. The uranium (VI) determination method in the technological products

    International Nuclear Information System (INIS)

    Fursa, L.I.; Belykevich, N.A.

    1994-01-01

    The method includes an extraction of the uranyl nitrate by solution' hexa butyl tries amide of phosphoric acid in the hexane, a reextraction of uranium by arsenazo III solution under pH 2 and following the solution' photometry. With the purpose of excluding the emulsion' formation under uranium reextraction has been added chloroform in volume ratio to hexane 1:(3.0-7.5). tabs. 2

  15. Antibacterial activity of extracts of six macroalgae from the northeastern brazilian coast

    Directory of Open Access Journals (Sweden)

    Lima-Filho José Vitor M.

    2002-01-01

    Full Text Available Hexane, chloroform and ethanol extracts of six marine macroalgae (Rhodophyta and Chlorophyta from North Ceará coast (Northeast Brazil were evaluated for antibacterial activity by the single disk method. Best results were shown by the hexane extracts of Amansia multifida against enteric Gram-negative strains such as Enterobacter aerogenes, Klebsiella pneumoniae, Pseudomonas aeruginosa, Salmonella typhi, S. cholerae-suis, Serratia marcescens, Vibrio cholerae and the Gram-positive bacteria Bacillus subtilis and Staphylococcus aureus.

  16. Medium Caliber Lead-Free Electric Primer. Version 2

    Science.gov (United States)

    2012-09-01

    2008). Safe Drinking Water Act of 1986 lists lead compounds as carcinogens (27 CCR 27001 – Dec. 2008). EPA began a Phase I assessment to determine...primer cups was our standard method, wet loading using solvents (hexane and iso -propanol) was investigated to reduce risk of accidental ignition...LOADING OPERATION (Single Die) Wet primer mix charge with solvent (Hexane/ Iso -Propanol) and stir to mix to a uniform slurry Insert primer cup in

  17. Report: Antimicrobial activity of Kalanchoe laciniata.

    Science.gov (United States)

    Manan, Maria; Hussain, Liaqat; Ijaz, Hira; Qadir, Muhammad Imran

    2016-07-01

    This study was conducted to identify antimicrobial potential of Kalanchoe laciniata. The plants were extracted with 30-70% aqueous-methanol and n-hexane. The antimicrobial activities were examined using agar well diffusion method against bacteria (Staphylococcus aureus, Escherichia coli) and fungi (Candidaalbicans). Results showed that E. coli were more sensitive than Staphylococcus aureus and Candida albicans. The largest zone of inhibition (52 mm) was recorded against E. coli with the n-hexane extract of Kalanchoe laciniata.

  18. Poly(ethylene oxide) surfactant polymers

    OpenAIRE

    VACHEETHASANEE, KATANCHALEE; WANG, SHUWU; QIU, YONGXING; MARCHANT, ROGER E.

    2004-01-01

    We report on a series of structurally well-defined surfactant polymers that undergo surface-induced self-assembly on hydrophobic biomaterial surfaces. The surfactant polymers consist of a poly(vinyl amine) backbone with poly(ethylene oxide) and hexanal pendant groups. The poly(vinyl amine) (PVAm) was synthesized by hydrolysis of poly(N-vinyl formamide) following free radical polymerization of N-vinyl formamide. Hexanal and aldehyde-terminated poly (ethyleneoxide) (PEO) were simultaneously att...

  19. Green solvents and technologies for oil extraction from oilseeds

    OpenAIRE

    Kumar, S. P. Jeevan; Prasad, S. Rajendra; Banerjee, Rintu; Agarwal, Dinesh K.; Kulkarni, Kalyani S.; Ramesh, K. V.

    2017-01-01

    Oilseeds are crucial for the nutritional security of the global population. The conventional technology used for oil extraction from oilseeds is by solvent extraction. In solvent extraction, n-hexane is used as a solvent for its attributes such as simple recovery, non-polar nature, low latent heat of vaporization (330?kJ/kg) and high selectivity to solvents. However, usage of hexane as a solvent has lead to several repercussions such as air pollution, toxicity and harmfulness that prompted to...

  20. The EED [Emergencies Engineering Division] solvent extraction process for the removal of petroleum-derived hydrocarbons from soil

    International Nuclear Information System (INIS)

    Bastien, C.Y.

    1994-03-01

    Research was conducted to investigate the ability of hexane and natural gas condensate (NGC) to extract three different types of hydrocarbon contaminant (light crude oil, diesel fuel, and bunker C oil) from three types of soil (sand, peat, and clay). A separate but related study determined the efficiency of solvent extraction (using hexane and five other solvents but not NGC) for removal of polychlorinated biphenyls (PCB) from contaminated soil. The process developed for this research includes stages of mixing, extraction, separation, and solvent recovery, for eventual implementation as a mobile solvent extraction unit. In experiments on samples created in the laboratory, extraction efficiencies of hydrocarbons often rose above 95%. On samples from a petroleum contaminated site, average extraction efficiency was ca 82%. Sandy soils contaminated in the laboratory were effectively cleaned of all hydrocarbons tested but only diesel fuel was successfully extracted from peat soils. No significant differences were observed in the effectiveness of hexane and NGC for contamination levels above 3%. Below this number, NGC seems more effective at removing oil from peat while hexane is slightly more effective on clay soils. Sand is equally cleaned by both solvents at all contamination levels. Safety considerations, odor, extra care needed to deal with light ends and aromatics, and the fact that only 26% of the solvent is actually usable make NGC an unfeasible option in spite of its significantly lower cost compared to hexane. For extracting PCBs, a hexane/acetone mixture proved to have the best removal efficiency. 14 refs., 14 figs., 7 tabs

  1. Toxic Effects of Couroupita guianensis Against Spodoptera litura (Fabricius) (Lepidoptera: Noctuidae).

    Science.gov (United States)

    Baskar, K; Ignacimuthu, S; Jayakumar, M

    2015-02-01

    Laboratory experiments were conducted to find out the efficacy of different crude extracts and fractions of Couroupita guianensis (Lecythidaceae) against Spodoptera litura (Fabricius). Results revealed that hexane, chloroform and ethyl acetate extracts of C. guianensis showed larvicidal and pupicidal activities against S. litura. Maximum larvicidal activity (68.66%) was observed in hexane extract at 5.0% concentration followed by chloroform and ethyl acetate extracts, and least LC50 value of 2.64% was observed in hexane extract. A 100% pupicidal activity was observed in hexane extract. Based on the efficacy of crude extracts, the effective crude extract (hexane extract) was further fractionated and subjected to screening for biological activities against S. litura. Among the eight fractions isolated from the hexane extract, fraction 8 showed maximum antifeedant activity (81. 8%) and larvicidal activity (76.9%) at 1000-ppm concentration; this fraction showed least LC50 value of 375.92 ppm for larvicidal activity. Cent per cent pupicidal activity was recorded. Reduced midgut and hemolymph protein contents were observed at 1000 ppm of fraction 8. Histopathological studies revealed that fraction 8 severely damaged the midgut cells of S. litura. This fraction could be used to develop botanical formulation to control agricultural pests.

  2. Antioxidant activities of different solvent extracts of Piper retrofractum Vahl. using DPPH assay

    Science.gov (United States)

    Jadid, Nurul; Hidayati, Dewi; Hartanti, Sylviana Rosyda; Arraniry, Byan Arasyi; Rachman, Rizka Yuanita; Wikanta, Wiwi

    2017-06-01

    Piper retrofractum Vahl., which belongs to the family Piperaceae, is geographically dispersed in tropical region including Indonesia. They are well-known spice possessing high medicinal properties. This study aimed to determine the antioxidant activity of P. retrofractum fruit, extracted with different solvents (methanol, ethyl acetate, n-hexane) using 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay. This research was carried out using different concentrations of methanol, ethyl acetate, and n-hexane extracts, (0, 5, 15, 30, 45, 60 ppm). Ascorbic acid was also used as positive antioxidant control. The percentage of inhibition and IC50 were measured. The results showed that the DPPH free radicals were scavenged by all plant extracts in a concentration dependent manner. Moreover, the IC50 values for DPPH radicals with methanol, ethyl acetate and n-hexane extract of the P. retrofractum Vahl. were found to be 101.74; 66.12 and 57.66 ppm, respectively. Interestingly, the IC50 value of n-hexane extract (57.66 ppm) was lower than ascorbic acid (66.12 ppm), indicating that n-hexane extract was a more potent scavenger of free radicals than methanol and ethyl acetate extracts. Taken together, our results suggested that n-hexane extract of P. Retrofractum Vahl. might contain potential antioxidant compounds.

  3. Sea Cucumber Lipid-Soluble Extra Fraction Prevents Ovalbumin-Induced Allergic Airway Inflammation.

    Science.gov (United States)

    Lee, Da-In; Kang, Shin Ae; Md, Anisuzzaman; Jeong, U-Cheol; Jin, Feng; Kang, Seok-Joong; Lee, Jeong-Yeol; Yu, Hak Sun

    2018-01-01

    In a previous study, our research group demonstrated that sea cucumber (Apostichopus japonicus) extracts ameliorated allergic airway inflammation through CD4 + CD25 + Foxp3 + T (regulatory T; Treg) cell activation and recruitment to the lung. In this study, we aimed to determine which components of sea cucumber contribute to the amelioration of airway inflammation. We used n-hexane fractionation to separate sea cucumber into three phases (n-hexane, alcohol, and solid) and evaluated the ability of each phase to elevate Il10 expression in splenocytes and ameliorate symptoms in mice with ovalbumin (OVA)/alum-induced asthma. Splenocytes treated with the n-hexane phase showed a significant increase in Il10 expression. In the n-hexane phase, 47 fatty acids were identified. Individual fatty acids that comprised at least 5% of the total fatty acids were 16:0, 16:1n-7, 18:0, 18:1n-7, 20:4n-6, and 20:5n-3 (eicosapentaenoic acid). After administering the n-hexane phase to mice with OVA/alum-induced asthma, their asthma symptoms were ameliorated. Several immunomodulatory effects were observed in the n-hexane phase-pretreated group, compared with a vehicle control group. First, eosinophil infiltration and goblet cell hyperplasia were significantly reduced around the airways. Second, the concentrations of Th2-related cytokines (IL-4, IL-5, and IL-13) and Th17-related cytokines (IL-17) were significantly decreased in the spleen and bronchoalveolar lavage fluid (BALF). Finally, the concentrations of TGF-β and IL-10, which are associated with Treg cells, were significantly increased in the BALF and splenocyte culture medium. In conclusion, a fatty acid-rich fraction (n-hexane phase) of sea cucumber extract ameliorated allergic airway inflammation in a mouse model.

  4. Catalytic purification of waste gases containing VOC mixtures with Ce/Zr solid solutions

    International Nuclear Information System (INIS)

    Gutierrez-Ortiz, Jose I.; De Rivas, Beatriz; Lopez-Fonseca, Ruben; Gonzalez-Velasco, Juan R.

    2006-01-01

    This study has been undertaken to investigate the efficiency of ceria, zirconia, and Ce x Zr 1-x O 2 mixed oxides as catalysts for the vapour-phase destruction in air of single model VOCs (n-hexane, 1,2-dichloroethane and trichloroethylene) and non-chlorinated VOC/chlorinated VOC binary mixtures. Considering all catalyst compositions examined for the individual destruction of these compounds, activity for complete oxidation decreased in the following order: n-hexane 0.5 Zr 0.5 O 2 and Ce 0.15 Zr 0.85 O 2 ) were different than that with the best performance for n-hexane oxidation (CeO 2 ). Concerning chlorinated VOCs conversion, it was observed that notable improvements in catalyst activity of CeO 2 could be achieved through structural doping with Zr ions. Mixed oxides exhibited promoted redox and acid properties, which resulted catalytically relevant for the oxidation of 1,2-dichloroethane and trichloroethylene. In contrast, the combustion of n-hexane was essentially controlled by surface oxygen species, which were more abundant on CeO 2 . Attainment of high n-hexane conversions with CeO 2 was also attributed in part to the hydrophobicity of the support and the reduced interaction with carbon dioxide. Significant 'mixture effects' on both activity and selectivity were noticed when a given chlorinated feed was decomposed in the presence of n-hexane. On one hand, each VOC decreased the reactivity of the other relative to that of the pure compound resulting in higher operating temperatures to achieve adequate destruction. Competitive adsorption played an important role in the reciprocal inhibition effects detected with all catalysts. On the other hand, the selectivity to HCl was noticeably enhanced when n-hexane was co-fed, probably due to the increased presence of water generated as an oxidation product. (author)

  5. Antileishmanial potential of medicinal plant extracts from the North-West of Morocco

    Directory of Open Access Journals (Sweden)

    Abdelhakim Bouyahya

    2018-03-01

    Full Text Available The aim of this study is to evaluate the antileishmanial activity of selected medicinal plants from the North-West of Morocco. Plant extracts were prepared by maceration using methanol, ethanol, and n-hexane. The antileishmanial activity was evaluated against Leishmania major, Leishmania tropica, and Leishmania infantum using MTT (3-(4.5-dimethylthiazol-2yl-2.5-diphenyltetrazolium bromide assay. All plant extracts showed a reducing in cell promastigotes viability with variability depending on tested strains and type of extracts. The n-hexane extract showed the highest antileishmanial activity and L. infantum was the most sensitive parasite. The best growth inhibition was observed with Cistus crispus n-hexane extract against L. major (IC50 = 47.29 ± 2.25 μg/mL, Arbutus unedo n-hexane extract against L. infantum (IC50 = 64.05 ± 1.44 μg/mL and Arbutus unedo n-hexane extract against L. tropica (IC50 = 79.57 ± 2.66 μg/mL. Considering these results, medicinal plants from the North-West of Morocco could constitute a promoter source for antileishmanial compounds.

  6. Study of the selective abstration reaction of the hydrogen atom in the radiolysis and photolysis of alkane mixture at 77 K

    International Nuclear Information System (INIS)

    Guedes, S.M.L.

    1979-01-01

    The occurence of the selective abstraction reaction of the solute hydrogen atom by hydrogen atom produced during radiolysis or photolysis of the systems such as neopentane/cyclo-hexane/HI, neopentane/2,3 dimethylbutane, n-pentane/HI/cyclo-hexane and cyclo-hexane/HI/n-pentane, at 77 K is studied. Experiments have been undertaken on the kinetics nature of the active species, the H atom, during radiolysis and photolysis of the neopentane/cyclo-hexane/HI system at 77 K, presenting competitive reactions. Studies have also been made on the occurrence of the selective abstraction reaction in inverted systems, in which the concentrations of the components of a system are so much altered that the solute becomes the solvent and vice-versa, in the other system. By means of photolysis at 77 K, it has been observed that for the two systems constitued by the cyclo-hexane and n-pentane the selective abstraction reaction occurs. However, for radiolysis of that same two systems it has been observed that only the hydrogen atom abstraction reaction corresponding to the solvent occurs. (Author) [pt

  7. Cytotoxicity and Antiproliferative Activity Assay of Clove Mistletoe (Dendrophthoe pentandra (L. Miq. Leaves Extracts

    Directory of Open Access Journals (Sweden)

    Vida Elsyana

    2016-01-01

    Full Text Available Clove mistletoe (Dendrophthoe pentandra (L. Miq. is a semiparasitic plant that belongs to Loranthaceae family. Clove mistletoe was traditionally used for cancer treatment in Indonesia. In the present study, we examined cytotoxicity of clove mistletoe leaves extracts against brine shrimps and conducted their antiproliferative activity on K562 (human chronic myelogenous leukemia and MCM-B2 (canine benign mixed mammary cancer cell lines in vitro. The tested samples were water extract, ethanol extract, ethanol fraction, ethyl acetate fraction, and n-hexane fraction. Cytotoxicity was screened using Brine Shrimp Lethality Test (BSLT. Antiproliferative activity was conducted using Trypan Blue Dye Method and cells were counted using haemocytometer. The results showed that n-hexane fraction exhibited significant cytotoxicity with LC50 value of 55.31 μg/mL. The n-hexane fraction was then considered for further examination. The n-hexane fraction of clove mistletoe could inhibit growth of K562 and MCM-B2 cancer cell lines in vitro. The inhibition activity of clove mistletoe n-hexane fraction at concentration of 125 μg/mL on K562 cancer cell lines was 38.69%, while on MCM-B2 it was 41.5%. Therefore, it was suggested that clove mistletoe had potential natural anticancer activity.

  8. Studies of the influence of different anions on extraction of neodymium with di(1-methylheptyl)methyl phosphonate

    International Nuclear Information System (INIS)

    Chun-Hui Huang; Rong-Fang Xi; Hai Guo; Guang-Xian Xu

    1988-01-01

    A study was made on extraction of Nd(NCS) 3 , Nd(ClO 4 ) 3 , Nd(NO 3 ) 3 by di-(1-methylhexyl)methyl phosphonate (P-350) in hexane. ΔG 0 (kJ/mol), ΔH 0 (kJ/mol) and ΔS 0 (kJ/mol) were calculated. They are equal to: -9.719, -29.92, -67.78 for P-350(hexane)-Nd(NCS) 3 system; 3.752, -74.31, -261.9 for P-350((hexane)-Nd(ClO 4 ) 3 system; 2.265, -22.69, -83.68 for P-350(hexane)-Nd(NO 3 ) 3 system. Structure of extracted complexes in hexane solution and corresponding solid complexes were correlated with triphenylphosphine oxide as P-350 model. Data of IR-spectroscopy show, that absorption bands of complexes in saturated organic solvents or in the solid phase are shifted to the region of lower frequencies as compared to absorption bands of corresponding salts. This testifies to similarity of complex structures in both phases

  9. Evaluation of in vitro antioxidant potential of different polarities stem crude extracts by different extraction methods of Adenium obesum

    Directory of Open Access Journals (Sweden)

    Mohammad Amzad Hossain

    2014-09-01

    Full Text Available Objective: To select best extraction method for the isolated antioxidant compounds from the stems of Adenium obesum. Methods: Two methods used for the extraction are Soxhlet and maceration methods. Methanol solvent was used for both extraction method. The methanol crude extract was defatted with water and extracted successively with hexane, chloroform, ethyl acetate and butanol solvents. The antioxidant potential for all crude extracts were determined by using 1, 1-diphenyl-2- picrylhydrazyl method. Results: The percentage of extraction yield by Soxhlet method is higher compared to maceration method. The antioxidant potential for methanol and its derived fractions by Soxhlet extractor method was highest in ethyl acetate and lowest in hexane crude extracts and found in the order of ethyl acetate>butanol>water>chloroform>methanol>hexane. However, the antioxidant potential for methanol and its derived fractions by maceration method was highest in butanol and lowest in hexane followed in the order of butanol>methanol>chloroform>water>ethyl acetate>hexane. Conclusions: The results showed that isolate antioxidant compounds effected on the extraction method and condition of extraction.

  10. Uji Fitokimia, Toksisitas dan Aktivitas Antioksidan Fraksi n-heksan dan Etil Asetat terhadap Ekstrak Jahe Merah (Zingiber officinale var. amarum

    Directory of Open Access Journals (Sweden)

    Alpina Nora Kaban

    2016-11-01

    Full Text Available Has conducted research on the phytochemical test, toxicity test and test the antioxidant activity of the fraction of n-hexane and ethyl acetate to extract red ginger (Zingiber officinale amarum var.. The dried leaves weighing 382 grams, was macerated using methanol, filtered and concentrated by rotary evaporator. Then the total extract of red ginger in fractionation with n-hexane and ethyl acetate. Based on the test results of secondary metabolites phytochemical extracts of total red ginger (Zingiber officinale var amarum. Are alkaloids, flavonoids, triterpenoids and phenolic. N-hexane fraction contains alkaloids, flavonoids, steroids, triterpenoids and phenolic. Ethyl acetate fractions contain alkaloids, flavonoids, triterpenoids and phenolic. Toxicity test showed the mortality rate of shrimp larvae Artemia salina Leach using Probit Analysis SAS (Statistical Analysis System to determine the value of 50% Lethal Concentration (LC50, showed that the fraction of n-hexane toxicity with LC50 values of 63.8130 ppm; extracts of total was 71.0121 ppm and ethyl acetate was 3821.89 ppm. Test the antioxidant activity using DPPH free radical reduction in the spectrophotometer and IC50 values obtained on a total extract was 32.19 ppm; n-hexane was fraction 35.63 ppm; and ethyl acetate fraction was 25.69 ppm.

  11. The influence of extraction methods on composition and antioxidant properties of rice bran oil

    Directory of Open Access Journals (Sweden)

    Noppawat Pengkumsri

    2015-09-01

    Full Text Available AbstractThe current study was employed to assess the influence of the different extraction methods on total tocols, γ-oryzanol content, and antioxidant properties of Chiang Mai Black rice, Mali Red rice, and Suphanburi-1 Brown rice bran oil. Rice bran oil (RBO was extracted by Hexane, Hot pressed, Cold pressed, and Supercritical Fluid Extraction (SFe methods. High yield of RBO was extracted by hexane and SFe methods. Total and subgroups of tocols, and γ-oryzanol content were determined by HPLC. The hexane extracted sample accounts for high content of γ-oryzanol and tocols. Besides, all of RBO extracts contain a significantly high amount of γ-tocotrienol. In vitro antioxidant assay results indicated that superior quality of oil was recovered by hexane extraction. The temperature in the extraction process also affects the value of the oil. Superior quality of oil was recovered by hexane extraction, in terms of phytochemical contents and antioxidant properties compared to other tested extraction methods. Further, thorough study of factors compromising the quality and quantity of RBO recovery is required for the development of enhanced functional foods and other related products.

  12. Genotoxic and cytotoxic potential of whole plant extracts of Kalanchoe laciniata by Ames and MTT assay.

    Science.gov (United States)

    Sharif, Ali; Akhtar, Muhammad Furqan; Akhtar, Bushra; Saleem, Ammara; Manan, Maria; Shabbir, Maryam; Ashraf, Muneeb; Peerzada, Sohaib; Ahmed, Shoaib; Raza, Moosa

    2017-01-01

    Lack of data on safety of herbal medicines have endangered human health and life. The present study evaluated the genotoxic and mutagenic effect of Kalanchoe laciniata to access the safety and usefulness of the medicinal plant. Aqua-methanolic and n-hexane extracts of K. laciniata were evaluated for the genotoxic potential using Ames assay and cytotoxicity was evaluated using MTT assay. Ames assay was conducted using two strains of Salmonella typhimurium TA-100 and TA-102 whereas MTT assay was performed on baby hamster kidney cell line BHK-21. Aqua-methanolic extract of K. laciniata exhibited significant mutagenicity when exposed to TA-102 strain with a mutagenic index of 50.66 and 54.74 at maximum dose 150 mg/plate. The extract was also mutagenic to TA-100 strain but to a lesser extent. M.I of n-hexane extract was 12.15 and 15.51 for TA-100 and TA-102 respectively. n-hexane extract was mutagenic but little difference was observed between results of two strains. Both extracts were found to be cytotoxic with an IC 50 of 321.9 and 638.5 µg/mL for aqua-methanolic and n-hexane extracts respectively. On the basis of results it was concluded that aqua-methanolic and n-hexane extracts of K. laciniata possess mutagenic and cytotoxic potential. It is suggested to explore the plant further to evaluate its safety in rodents and other species.

  13. Desolventizing of soybean oil/azeotrope mixtures using ceramic membranes.

    Science.gov (United States)

    de Melo, Jonas R M; Tiggeman, Lidia; Rezzadori, Katia; Steffens, Juliana; Palliga, Marshall; Oliveira, J Vladimir; Di Luccio, Marco; Tres, Marcus V

    2017-08-01

    This work investigates the use of ceramic membranes with different molecular weight cut-offs (MWCOs: 5, 10 and 20 kDa) to desolventize azeotropic solvent mixtures (ethanol/n-hexane and isopropyl alcohol/n-hexane) from soybean oil/azeotrope micelles. Results show that a decrease in the MWCO of a membrane and an increase in the solvent mass ratio in the mixture resulted in a significant reduction in the permeate flux. The 20 kDa membrane presented the highest permeate flux, 80 and 60 kg/m 2 h for the soybean oil/n-hexane/isopropyl alcohol and soybean oil/n-hexane/ethanol azeotropes, respectively, for an oil to solvent ratio of 1:3 (w/w). The highest oil retention was found using the n-hexane/isopropyl alcohol azeotrope, around 25% in the membrane with the lowest MWCO, that is, 5 kDa. It is shown that the azeotropic mixtures provided intermediate characteristics compared to the original pure solvent behavior.

  14. Phytochemical screening, antiproliferative and cytotoxic activities of the mosses Rhytidiadelphus triquetrus (Hedw. Warnst. and Tortella tortuosa (Hedw. Limpr.

    Directory of Open Access Journals (Sweden)

    Muhammet Şamil Yağlıoğlu

    2017-06-01

    Full Text Available The paper presents information about the phytochemical analysis, antiproliferative and cytotoxic activities of Rhytidiadelphus triquetrus and Tortella tortuosa extracts. The cytotoxic activities of some extracts shows highest antiproliferative activities were detected with Lactate Dehydrogenase Leakage Assay. Sixteen components obtained from hexane extracts were determined by GC/MS. Palmitic acid was identified as the main component. The phenolic components of the other extracts were determined by HPLC-TOF/MS. 4-hydroxy benzoic acid, salicylic acid, gallic acid, caffeic acid, and gensitic acid were detected as the main components in all extracts. The hexane, chloroform, ethyl acetate extracts of studied mosses and the EtOAc and hexane extracts of R. triquetrus showed statistically significant antiproliferative activities.

  15. Evaluation of Antimicrobial Activity of Root Extracts of Abitulon indicum

    Directory of Open Access Journals (Sweden)

    Krishna Rao MORTHA

    2015-06-01

    Full Text Available Antimicrobial activity of Abitulon indicum roots was studied against seven pathogenic bacteria and three fungal strains by agar well diffusion method. Antimicrobial activity was recorded for hexane, chloroform, methanol, ethanol and aqueous extracts. Alcohol (ethanol and methanol extracts exhibited the highest degree of antimicrobial activity compared to aqueous, chloroform and hexane extracts. Pseudomonas aeruginosa was turned out to be the most susceptible bacterium to the crude root chemical constituents, using the standard Tetracycline and Clotrimazole. Minimum inhibition concentration values of hexane, chloroform, methanol, ethanol and aqueous extracts were determined by the agar dilution method and ranged between 62.5 and 1,000 µg. The study suggested that the root extracts possess bioactive compounds with antimicrobial activity against the tested bacteria and fungi, revealing a significant scope to develop a novel broad spectrum of antimicrobial drug formulation from Abitulon indicum.

  16. Mobility Studies of (14)C-Chlorpyrifos in Malaysian Oil Palm Soils.

    Science.gov (United States)

    Halimah, Muhamad; Ismail, B Sahid; Nashriyah, Mat; Maznah, Zainol

    2016-01-01

    The mobility of (14)C-chlorpyrifos using soil TLC was investigated in this study. It was found that chlorpyrifos was not mobile in clay, clay loam and peat soil. The mobility of (14)C-chlorpyrifos and non-labelled chlorpyrifos was also tested with silica gel TLC using three types of developing solvent hexane (100%), hexane:ethyl acetate (95:5, v/v); and hexane:ethyl acetate (98:2, v/v). The study showed that both the (14)C-labelled and non-labelled chlorpyrifos have the same Retardation Factor (Rf) for different developing solvent systems. From the soil column study on mobility of chlorpyrifos, it was observed that no chlorpyrifos residue was found below 5 cm depth in three types of soil at simulation rainfall of 20, 50 and 100 mm. Therefore, the soil column and TLC studies have shown similar findings in the mobility of chlorpyrifos.

  17. Actividad antibacteriana de algunas especies medicinales de Eupatorium contra bacterias patógenas resistentes a antibióticos

    Directory of Open Access Journals (Sweden)

    Edgar García-Sánchez

    2015-07-01

    Full Text Available Thirty six samples arising from hexane, dichloromethane, and methanol extracts from four medicinal Eupatorium species were screened against Gram positive and Gram negative resistant bacteria associated with nosocomial infections by disk diffusion method. The best antibacterial extracts were selected by correspondence analysis. The hexane extracts showed high inhibition against clinical isolated bacteria. The qualitative chemical analysis was realized in the best antibacterial hexane extracts. The main components identified were triterpenes and benzopyran compounds which of extensively had been reported their antibacterial activities. Our results showing that medicinal Eupatorium species studied in this work have metabolites secondary antibacterial particularly against antibiotic resistant strains, Klebsiella pneumoniae and Staphylococcus aureus and validate their uses in traditional medicine

  18. Antimicrobial activity of Aegiphila sellowiana Cham., Lamiaceae, against oral pathogens

    Directory of Open Access Journals (Sweden)

    Marcele A. Ferreira

    Full Text Available The antimicrobial activity of Aegiphila sellowiana Cham., Lamiaceae, against oral pathogens is reported. The Minimal Inhibitory Concentrations (MICs for inhibiting the microorganisms growth were determined using the broth microdilution method from the CLSI M7-A7 protocol. Chlorhexidine was used as the positive control. The ethanol crude extract of the aerial parts of A. sellowiana exhibited activity against the microorganisms tested in this work; however, the activity decreased after partition with n-hexane, dichloromethane, and ethyl acetate. Among the tested fractions, the n-hexane fraction was found to be the most effective against the evaluated oral pathogens. GC-MS analysis of this latter fraction revealed that fatty acids esters, steroids, and aliphatic sesquiterpene hydrocarbons are its major constituents. These compounds may be responsible for the activity of the n-hexane fraction, but other chemical constituents of the dichloromethane, ethyl acetate, and hydroalcoholic fraction may potentialize their activities in the crude extract.

  19. Chemical composition and antibacterial activity of Opuntia ficus-indica f. inermis (cactus pear) flowers.

    Science.gov (United States)

    Ennouri, Monia; Ammar, Imene; Khemakhem, Bassem; Attia, Hamadi

    2014-08-01

    Opuntia ficus-indica f. inermis (cactus pear) flowers have wide application in folk medicine. However, there are few reports focusing on their biological activity and were no reports on their chemical composition. The nutrient composition and hexane extracts of Opuntia flowers at 4 flowering stages and their antibacterial and antifungal activities were investigated. The chemical composition showed considerable amounts of fiber, protein, and minerals. Potassium (K) was the predominant mineral followed by calcium (Ca), magnesium (Mg), sodium (Na), iron (Fe), and zinc (Zn). The main compounds in the various hexane extracts were 9.12-octadecadienoic acid (29-44%) and hexadecanoic acid (8.6-32%). The antibacterial activity tests showed that O. inermis hexane extracts have high effectiveness against Escherichia coli and Staphylococcus aureus, making this botanical source a potential contender as a food preservative or food control additive.

  20. Lipase inhibitory activity of Carica papaya, Chrysophyllum cainito, Corcorus olitorius, Cympogon citrates and Syzygium cumini extracts

    Directory of Open Access Journals (Sweden)

    Briones, A.T.

    2017-09-01

    Full Text Available The lipase inhibitory action of Carica papaya, Chrysophyllum cainito, Corcorus olitorius, Cymbopogon citrates and Syzygium cumini were evaluated to explore for the presence of anti-obesity compounds and their potential weight-lowering activity. Enzyme inhibition results of the alcoholic extracts of the five plants showed that C. cainito has the highest percent inhibition at 74.91% while S. cumini, C. citratus, C. olitorius and C. papaya obtained less than 50% average inhibition. C. cainito was partitioned using hexane and ethyl acetate to further concentrate the bioactive compounds. The lipase inhibition assay of hexane and ethyl acetate extracts showed 92.11% inhibition and 21.9% inhibition, respectively. The greater activity in the former may imply that majority of potential anti-lipase constituents are found in the hexane portion.

  1. Release of volatile mercury from vascular plants

    Science.gov (United States)

    Siegel, S. M.; Puerner, N. J.; Speitel, T. W.

    1974-01-01

    Volatile, organic solvent soluble mercury has been found in leaves and seeds of several angiosperms. Leaves of garlic vine, avocado, and haole-koa release mercury in volatile form rapidly at room temperature. In garlic vine, the most active release is temperature dependent, but does not parallel the vapor-pressure temperature relationship for mercury. Mercury can be trapped in nitric-perchloric acid digestion fluid, or n-hexane, but is lost from the hexane unless the acid mixture is present. Seeds of haole-koa also contain extractable mercury but volatility declines in the series n-hexane (90%), methanol (50%), water (10%). This suggests that reduced volatility may accompany solvolysis in the more polar media.

  2. Optimizing the Production of Biodiesel Using Lipase Entrapped in Biomimetic Silica

    Energy Technology Data Exchange (ETDEWEB)

    I-Ching Kuan; Chia-Chi Lee; Bing-Hong Tsai; Shiow-Ling Lee; Wei-Ting Lee; Chi-Yang Yu [Department of Bioengineering, Tatung Univ., Taipei, Taiwan (China)

    2013-04-15

    We entrapped lipase from Pseudomonas cepacia in polyallylamine-mediated biomimetic silica, and then applied entrapped lipase to the synthesis of biodiesel with soybean oil or waste cooking oil as a feedstock. The effects of reaction temperature, substrate molar ratio (methanol/oil) and n-hexane content (w/w of oil) were evaluated using response surface methodology (RSM) combined with Box-Behnken design. The optimal reaction conditions for soybean oil were 43.6 deg C, substrate molar ratio of 4.3%, and 75% n-hexane. The predicted and experimental values of biodiesel conversion were 79% and 76%, respectively. The optimal reaction conditions for waste cooking oil were 43.3 deg C, substrate molar ratio of 5%, and 38% n-hexane. The predicted and experimental values of conversion were 68% and 67%, respectively. The conversion efficiency remained the same even after 1-month storage of entrapped lipase at 4 deg C or room temperature.

  3. Composição química da glândula abdominal da fêmea da mariposa Castnia licus (Drury (Lepidoptera:Castniidae: possíveis feromônios e precursores Chemical composition from female pheromone gland of Castnia licus (Drury (Lepidoptera: Castniidae

    Directory of Open Access Journals (Sweden)

    Lúcia M. C. Rebouças

    1999-09-01

    Full Text Available The hexane and methanolic extracts from pheromonal glands of Castnia licus (Drury virgin females have been studied. Analyses by gas chromatography and mass spectrometry allowed us to determine the major constituents present in the hexane extract as n-alkanes C21 to C30, (Z-9-hexadecenoic acid (C16, and (Z-9-octadecenoic acid (C18 and hexadecanoic acid (C16. Aldehyds, alkenes and acetates were also detected in low concentrations in the extracts. Female pheromone glands were analysed for pheromone precursors using the methanolic extract. In addition to the compounds methyl hexadecanoate and methyl (Z-9-octadecenoate, the glandular tissue contains a homologous series of methyl esters from C12 to C24. The hexane extract of the female abdomenal glands elicited activity from males in a behavioural bioassay.

  4. Phytochemistry, cytotoxicity and antiviral activity of Eleusine indica (sambau)

    Science.gov (United States)

    Iberahim, Rashidah; Yaacob, Wan Ahmad; Ibrahim, Nazlina

    2015-09-01

    Goose grass also known as Eleusine indica (EI) is a local medicinal plant that displays antioxidant, antimicrobial and anticancer activities. The present study is to determine the phytochemical constituents, cytotoxicity and antiviral activities for both crude extract and fraction obtained from the plant. The crude extract contained more secondary metabolites compared to the hexane fraction as gauged using standard phytochemical tests. Cytotoxicity screening against Vero cells using MTT assay showed that the CC50 values for crude extract and hexane fraction were 2.07 and 5.62 mg/ml respectively. The antiviral activity towards Herpes Simplex Virus type 1 (HSV-1) was determined using plaque reduction assay. The selective indices (SI = CC50 / EC50) for both methanol extract and hexane fraction were 12.2 and 6.2 respectively. These results demonstrate that the extract prepared from E. indica possesses phytochemical compound that was non cytotoxic to the cell with potential antiviral activity.

  5. Phytotoxic potential of Drimys brasiliensis Miers for use in weed control

    Directory of Open Access Journals (Sweden)

    Simoni Anese

    2015-10-01

    Full Text Available This study aims to evaluate the phytotoxicity potential of leaf and root extracts of Drimys brasiliensis on the germination and seedling growth of Panicum maximum and Euphorbia heterophylla and its influence on metaxylem cell size in the seedling roots of the latter specie. The leaf and root extracts were fractionated by partition chromatography, and the hexane and ethyl acetate fractions obtained from each organ were evaluated at different concentrations for phytotoxic activity in several bioassays. In seedling growth tests, we compared the effects of these fractions with the herbicide oxyfluorfen. The hexane fraction of the root extracts showed a higher inhibitory potential on the germination and growth of weeds and reduced the average size of the metaxylem cells of E. heterophylla roots by more than 50%.The inhibitory effects of the root hexane fraction on seedling growth was similar to the herbicide, indicating that D. brasiliensis is a possible alternative form of control for the weed species examined.

  6. Allelopathic potential of Artemisia arborescens: isolation, identification and quantification of phytotoxic compounds through fractionation-guided bioassays.

    Science.gov (United States)

    Araniti, Fabrizio; Lupini, Antonio; Sorgonà, Agostino; Conforti, Filomena; Marrelli, Mariangela; Statti, Giancarlo Antonio; Menichini, Francesco; Abenavoli, Maria Rosa

    2013-01-01

    The aerial part of Artemisia arborescens L. (Asteraceae) was extracted with water and methanol, and both extracts were fractionated using n-hexane, chloroform, ethyl acetate and n-butanol. The potential phytotoxicity of both crude extracts and their fractions were assayed in vitro on seed germination and root growth of lettuce (Lactuca sativa L.), a sensitive species largely employed in the allelopathy studies. The inhibitory activities were analysed by dose-response curves and the ED 50 were estimated. Crude extracts strongly inhibited both germination and root growth processes. The fraction-bioassay indicated the following hierarchy of phytotoxicity for both physiological processes: ethyl acetate ≥ n-hexane > chloroform ≥ n-butanol. On the n-hexane fraction, GC-MS analyses were carried out to characterise and quantify some of the potential allelochemicals. Twenty-one compounds were identified and three of them, camphor, trans-caryophyllene and pulegone were quantified.

  7. THE EFFECTIVENES OF ETANOL EXTRACT, PARTITION N-HEKSANA, AND CROMATHOGRAPHY FRACTION OF MOMORDICA CHARANTIA L. TO LOWER BLOOD GLUCOSE LEVEL

    Directory of Open Access Journals (Sweden)

    Ni Luh Putu Kusuma Clara Dewinda

    2017-08-01

    Full Text Available This study aims to determine the effectiveness of the ethanol extract, partition n-hexane, and chromatography fractions Momordica charantia L. in lowering blood glucose levels in experimental diabetic male rats.  This study used 25 male rats were divided into five treatment groups P0 (negative control, P1 (positive control, P2 (ethanol extract, P3 (partition n-hexane, and P4 (chromatographic fraction the variable observed glucose levels blood for 21 days. Blood glucose levels were analyzed on days -1, 0, 4, 11, 18. The bill, which is used in the form of a completely randomized design (CRD. The data obtained and analyzed by using Split in Time. The results showed of giving chromatographic fractions bitter melon 50 mg / kg body weight can reduce blood glucose levels in hyperglycemic rats better than the ethanol extract 200 mg / kg body weight and partition n-hexane 50 mg / kg body weight.

  8. Assessment of Adiantum incisum, Alternanthera pungens and Trichodesma indicum as bio-insecticides against stored grain pests

    International Nuclear Information System (INIS)

    Safdar, N.; Yasmin, A.

    2017-01-01

    This study investigated the insecticidal potential of Adiantum incisum Forssk (Pteridaceae), Alternanthera pungens Kunth (Amaranthaceae) and Trichodesma indicum L. (Boraginaceae). Aqueous, methanolic and n-hexane extracts of whole plants (roots, stem and leaves) were prepared using maceration technique. Insecticidal activities of aqueous, methanolic and n-hexane extracts of three plants (10, 20 and 30 mg/mL) were evaluated by impregnated filter paper insecticidal assay. Methanol and hexane extracts of Adiantum incisum gave effective LD 50 (15.3 mg/mL) against Callosobruchus chinensis and Sitophilus oryzae (LD5022 mg/mL) after 24 hours respectively. Present research elucidates the important phytochemicals (alkaloids, saponins and tannins) in three plants by FTIR and good insecticidal activity (LD50 < 25 mg/mL in 24 hours) against Callosobruchus chinensis and Sitophilus oryzae. Current study promotes further investigations for using these plant extracts as anti-feedants, repellents, fumigants and formulation of non-toxic bio-insecticides. (author)

  9. Evaluation of the insecticidal activity of the extracts from Piper grande Vahl (Piperaceae) using the biological model Drosophila melanogaster

    International Nuclear Information System (INIS)

    Granados N, Hillmer; Saez V, Jairo; Robles, Carolina; Vasquez, Luis F; Moreno, Maria E; Acevedo, Jose M; Pelaez, Carlos A; Callejas, Ricardo

    2002-01-01

    In this study, using the life cycle interruption test with the Drosophila melanogaster model, under (in-vitro conditions), the n-Hexane (roots and stems) and the EtOAc (roots and leaves) extracts were evaluated as insecticides and the results were promising. The larvae instars showed a significant activity reflected in the reduction of pupae population with respect to the control. The step from Pupae to adult did no show inhibition because in all cases the average of the relation pupae adult is found in values very near 1. The n-Hexane and the EtOAc extracts from roots were the most active with LC50 of 698.2 ppm and 1210.7 ppm. The n-Hexane (stems) and EtOAc (leaves) extracts showed a moderate activity with LC50 of 1654.1 ppm and 2376.0 ppm

  10. ISOLASI DAN IDENTIFIKASI ARTEMISININ DARI HERBA Artemisia annua L .

    Directory of Open Access Journals (Sweden)

    Sukmayati Alegantina

    2012-07-01

    Full Text Available Abstract. Malaria is still a major problem in Indonesia, because mortality in patients with severe malaria remains high. Many cases are occurs in endemic areas (e.g. Papua,Kalimantan, Bali and Sulawesi. Chloroquin is the most common antimalarial drug which is widely used since 1934. Plasmodium falciparum resistant to chloroquine was reported in some countries (e.g. Thailand, Vietnam, Indonesia, and Bangladesh. To delay the development of resistance, WHO recommended antimalarial combination therapy. Artemisinin and its derivatives (artesunate, artemether, dihydroartemisin produce rapid clearance of parasitemia and rapid resolution of symptoms compare with chloroquine. Artemisinin is obtained from Artemisia annua L. Even though there are some research produced a chemical synthetic of artemisinin, but it is not efficient and notstable. Our purposes are to conduct a preliminary research to obtain a method of isolation and identification of artemisinin which is the first step to develop a raw material of artemisinin as antimalarial drug in Indonesia.The first step of isolation is extraction from herb Artemisia annua L with n-hexane thatproduced n-hexane extract, this process is well-known as soxhletation. The second step isidentification of chemical substances from n-hexane extract. The third step is to obtain isolate from n-hexane extract by fractionation with acetonitril and separation with column chromatography. The last step is chemical and physical identification of isolateby TLC (Thin Layer (Chromatography and FT-IR.The result from n-hexane extract measurement is 4.33 % and from acetonitril fraction is2. 40 %. Chemical identification of n-hexan extract found there are terpenoid, phenol, flavonoid, fatty acid, atsiri oil and saponin. Organoleptic identification of isolate is white crystal, monosubstrate, odorless and bitter. Identification of isolate with TLC and FT-IR confirmed that the isolate is artemisinin.Keywords: artemisinin, Artemisia

  11. Evaluation of different tissue de-paraffinization procedures for infrared spectral imaging.

    Science.gov (United States)

    Nallala, Jayakrupakar; Lloyd, Gavin Rhys; Stone, Nicholas

    2015-04-07

    In infrared spectral histopathology, paraffin embedded tissues are often de-paraffinized using chemical agents such as xylene and hexane. These chemicals are known to be toxic and the routine de-waxing procedure is time consuming. A comparative study was carried out to identify alternate de-paraffinization methods by using paraffin oil and electronic de-paraffinization (using a mathematical computer algorithm) and their effectiveness was compared to xylene and hexane. Sixteen adjacent tissue sections obtained from a single block of a normal colon tissue were de-paraffinized using xylene, hexane and paraffin oil (+ hexane wash) at five different time points each for comparison. One section was reserved unprocessed for electronic de-paraffinization based on a modified extended multiplicative signal correction (EMSC). IR imaging was carried out on these tissue sections. Coefficients based on the fit of a pure paraffin model to the IR images were then calculated to estimate the amount of paraffin remaining after processing. Results indicate that on average xylene removes more paraffin in comparison to hexane and paraffin oil although the differences were small. This makes paraffin oil, followed by a hexane wash, an interesting and less toxic alternative method of de-paraffinization. However, none of the chemical methods removed paraffin completely from the tissues at any given time point. Moreover, paraffin was removed more easily from the glandular regions than the connective tissue regions indicating a form of differential paraffin retention based on the histology. In such cases, the use of electronic de-paraffinization to neutralize such variances across different tissue regions might be considered. Moreover it is faster, reduces scatter artefacts by index matching and enables samples to be easily stored for further analysis if required.

  12. Laboratory Evaluations of the Fractions Efficacy of Annona senegalensis (Annonaceae) Leaf Extract on Immature Stage Development of Malarial and Filarial Mosquito Vectors.

    Science.gov (United States)

    Lame, Younoussa; Nukenine, Elias Nchiwan; Pierre, Danga Yinyang Simon; Elijah, Ajaegbu Eze; Esimone, Charles Okechukwu

    2015-12-01

    Within the framework to control mosquitoes, ovicidal, larvicidal and pupicidal activity of Annona senegalensis leaf extract and its 4 fractions against Anopheles gambiae and Culex quinquefasciatus were evaluated in the laboratory conditions. Ovicidal test was performed by submitting at least 100 eggs of mosquitoes to 125, 250, 500, 1000 and 2000 ppm concentrations, while larvicidal and pupicidal effects were assessed by submitting 25 larvae or pupae to the concentrations of 2500, 1250, 625 and 312.5 ppm of plant extract or fractions of A. senegalensis. The eggs of An. gambiae were most affected by N-hexane (0.00% hatchability) and chloroform (03.67% hatchability) fractions compared to Cx. quinquefasciatus where at least 25 % hatchability were recorded at 2000 ppm. For larvicidal test, N-hexane (LC50= 298.8 ppm) and chloroform (LC50= 418.3 ppm) fractions were more effective than other fractions on An. gambiae larvae while, a moderate effectiveness was also observed with N-hexane (LC50= 2087.6 ppm), chloroform (LC50= 9010.1 ppm) fractions on Cx. quinquefasciatus larvae. The highest mortality percent of the pupae were also recorded with N-hexane and chloroform fractions on An. gambiae at 2500 ppm. As for Cx. quinquefasciatus only 50 % and 36 % mortality were recorded with N-hexane and chloroform fractions respectively. The extract of A. senegalensis was toxic on immature stage of mosquito species tested. By splitting methanolic crude extract, only N-hexane and chloroform fractions were revealed to possess a mosquitocidal effects and could be considered and utilized for future immature mosquito vectors control.

  13. Conversion of potash soap and lignin into liquid fuels. Final report; Suovan ja ligniinin jalostaminen polttonesteiksi. Loppuraportti

    Energy Technology Data Exchange (ETDEWEB)

    McKeough, P.; Oasmaa, A.

    1994-12-31

    The main task of the research is to estimate the suitability of catalytic hydration for refining of following rawmaterials into liquid fuels: concentrated black liquor, raw potash soap (especially birch containing mixed potash soap) and organosolv (Milox) lignin. When hydrating the concentrated black liquor catalytically (ammonium heptamolybdate/420 deg C or NiMo-Cr{sub 2}O{sub 3}/450 deg C) it is possible to convert about 30 wt-% of the original organic matter of the black liquor into hexane soluble oils. It is possible to remove the inorganic matter from the product oil by water extraction without reducing the amount of hexane suluble oil. The energy content of the hexane soluble oil is about 60 % of the energy content of the black liquor. The raw potash soap is cracked into oils and gases at 435- 450 deg C. The yield of the hexane soluble oil in nitrogen atmosphere without a catalyst is about 40 % of the organic matter of the potash soap. The calorific value of the oil is 42 MJ/kg, which corresponds to about 45 % energy yield. The presence of a catalyst and hydrogen gas increases the yield of hexane soluble oil (45 wt-%) and effects on the chemical composition of the product by increasing the portion of aliphatic hydrocarbons. It is possible to obtain oil of good quality from Milox lignin by using the catalytic hydration. At 420 deg C with 60 min retention time, at presence of the NiMo- Cr{sub 2}O{sub 3} catalyst and hydrogen gas, oil yield of 53 % and hexane soluble oil yield of 41 % (of organic matter of lignin) are obtained. The calorific value of the oil is 40 MJ/kg (Milox lignin 25 MJ/kg). (3 refs., 3 tabs., 1 fig.)

  14. HIDROLISIS ENZIMATIK MINYAK IKAN UNTUK PRODUKSI ASAM LEMAK OMEGA-3 MENGGUNAKAN LIPASE DARI Aspergillus niger [Enzymatic Hydrolysis of Fish Oil for Production of Omega-3 Fatty Acids Using Lipase Derived from Aspergillus niger

    Directory of Open Access Journals (Sweden)

    Sapta Raharja*

    2011-06-01

    Full Text Available Fish oil is the source of important fatty-acid, especially polyunsaturated fatty acid (PUFA omega-3, such as eicosapentaenoic acid (EPA and docosahexaenoic acid (DHA. Lipase catalysis activity of Aspergillus niger is low when it is used in fish oil hydrolysis. The activity of the lipase can be increased by adding organic solvent such as hexane into the media. This research aimed to determine temperature, pH and amount of water which produce the highest degree of hydrolysis of fish oil in the presence of hexane. Correlation between the highest degree of hydrolysis and the amount of omega-3 fatty acid was also investigated. The variables used in this research were temperatures (25-65 oC, pH (5-9, and water addition (1-5 %v/v. The highest degree of enzymatic hydrolysis of fish oil in the media without hexane was 28.07 % that was reached at 45oC and pH 5. In the presence of hexane, the highest degree of hydrolysis was 75.12 % which was reached at 5% water addition, temperature 45oC, and pH 5. GC-MS analysis showed that omega-3 fatty acid content especially EPA and DHA increased along with increase in the degree of hydrolysis. Concentration of omega-3 fatty acid produced without hexane addition was 18.42 % with EPA amounted to 12,17% and DHA 0,86%. Meanwhile omega-3 fatty acid content in the presence of hexane reached 21.93 % with EPA amounted to 17.75 % and DHA 1.21 %.

  15. Nanometre-sized pores in coal: Variations between coal basins and coal origin

    Science.gov (United States)

    Sakurovs, Richard; Koval, Lukas; Grigore, Mihaela; Sokolava, Anna; Ruppert, Leslie F.; Melnichenko, Yuri B.

    2018-01-01

    We have used small angle neutron scattering (SANS) to investigate the differences in methane and hexane penetration in pores in bituminous coal samples from the U.S., Canada, South Africa, and China, and maceral concentrates from Australian coals. This work is an extension of previous work that showed consistent differences between the extent of penetration by methane into 10–20 nm size pores in inertinite in bituminous coals from Australia, North America and Poland.In this study we have confirmed that there are differences in the response of inertinite to methane and hexane penetration in coals sourced from different coal basins. Inertinite in Permian Australian coals generally has relatively high numbers of pores in the 2.5–250 nm size range and the pores are highly penetrable by methane and hexane; coals sourced from Western Canada had similar penetrability to these Australian coals. However, the penetrability of methane and hexane into inertinite from the Australian Illawarra Coal Measures (also Permian) is substantially less than that of the other Australian coals; there are about 80% fewer 12 nm pores in Illawarra inertinite compared to the other Australian coals examined. The inertinite in coals sourced from South Africa and China had accessibility intermediate between the Illawarra coals and the other Australian coals.The extent of hexane penetration was 10–20% less than CD4 penetration into the same coal and this difference was most pronounced in the 5–50 nm pore size range. Hexane and methane penetrability into the coals showed similar trends with inertinite content.The observed variations in inertinite porosity between coals from different coal regions and coal basins may explain why previous studies differ in their observations of the relationships between gas sorption behavior, permeability, porosity, and maceral composition. These variations are not simply a demarcation between Northern and Southern Hemisphere coals.

  16. EKSTRAKSI DAN ANALISIS FITOSTEROL LEMBAGA GANDUM [Extraction and analysis of Phytosterol from wheat germ (Triticum sp.

    Directory of Open Access Journals (Sweden)

    Latifah K Darusman3

    2005-04-01

    Full Text Available Phytosterol may reduce the absorption of cholesterol, and used for preventing atherosclerosis. It is limited in soybean, but potentially abundant in wheat germ. Research on the utilization of wheat germ sterol had not been reported so far. Many aspects of germ sterol extraction from wheat germ and its characteristics were still unknown. In this research, the best extraction method, kinds and content of phytosterol from wheat germ were investigated.This research consisted of two steps: (1 extraction of phytosterol directly form whole germ and ground germ using hexane, and indirect extraction through germ oil using hexane and mixed solvent of hexane and ethanol, and direct extraction from ground germ using ethanol; (2 analysis of the type and content of phytosterol in the crude extract through the following steps: preparation of crude extract, fractionation, and analysis.Results showed that indirect extraction through germ oil was considered as the best method which yielded 1.37% of phytosterol. The highest yield was obtained when extracted using a mixed solvent of hexane – ethanol 82:18. However, the odor of ethanol and hexane (gasoline like odor was still detected. The solvent’s ratio of hexane to ethanol at 1:2 resulted better odor of the extract. Extraction of sterol using ethanol yielded 18.39% of sterol when the ratio of germ to ethanol at 1:10 (w/v was applied.Results of quantitative analysis on the main component of crude extract of wheat germ sterol showed that the total content of sterol extracted with mixed solvent was higher than those extracted with ethanol. The ratio of hexane to ethanol at 1:1 (v/v gave higher content of total sterol, stigmasterol and campesterol, whereas higher content of -sitosterol was produced at the solvent’s ratio of hexane to ethanol at 1:2 (v/v.

  17. Excited state Intramolecular Proton Transfer in Anthralin

    DEFF Research Database (Denmark)

    Møller, Søren; Andersen, Kristine B.; Spanget-Larsen, Jens

    1998-01-01

    Quantum chemical calculations performed on anthralin (1,8-dihydroxy-9(10H)-anthracenone) predict the possibility of an excited-state intramolecular proton transfer process. Fluorescence excitation and emission spectra of the compound dissolved in n-hexane at ambient temperature results in an unus......Quantum chemical calculations performed on anthralin (1,8-dihydroxy-9(10H)-anthracenone) predict the possibility of an excited-state intramolecular proton transfer process. Fluorescence excitation and emission spectra of the compound dissolved in n-hexane at ambient temperature results......, associated with an excited-state intramolecular proton transfer process....

  18. Determination of alpha-Tocopherol (vitamin E) in irradiated garlic by high performance liquid chromatography (HPLC)

    International Nuclear Information System (INIS)

    Rios, Magda Dias Goncalves; Penteado, Marilene de Vuono Camargo

    2003-01-01

    The effects of 60 Co ionizing radiations in doses of 0, 75, 100, 150, 200 and 250Gy on garlic, upon the α-tocopherol concentration were studied. The α-tocopherol contents were established by high performance liquid chromatography (HPLC), after direct hexane extraction from the garlic samples. The α-tocopherol was determined through normal phase column, and mobile phase was composed by hexane: iso-propyl alcohol (99:01 v/v), with 2mL/min flow rate and fluorescence detector. It is statistically shown that an irradiation dose of up to 150 Gy does not affect the garlic α-tocopherol content. (author)

  19. Characterization of some Jordanian oil shales by pyrolysis gas chromatography

    International Nuclear Information System (INIS)

    Jaradat, Q. M.

    1995-01-01

    Gas chromatography with flame ionization detector (GC-FID) was used to study pyrolysis of some Jordanian oil shale samples. Three sampls of different altitudes from El-Lajjun were studied. Pyrograms of solid sampls were studied at different temperature profiles. Solid-liquid extraction with water, methanol, or hexane allowed extraction of organics of different polarity. Hexane showed the highest extraction efficiency. Reproducibility of the pyrograms of the solid sample was evalualted. Relative standard deviation was 7.56%. (author). 7 refs., 8 figs

  20. Coefficients of interphase distribution and Gibbs energy of the transfer of nicotinic acid from water into aqueous solutions of ethanol and dimethylsulfoxide

    Science.gov (United States)

    Grazhdan, K. V.; Gamov, G. A.; Dushina, S. V.; Sharnin, V. A.

    2012-11-01

    Coefficients of the interphase distribution of nicotinic acid are determined in aqueous solution systems of ethanol-hexane and DMSO-hexane at 25.0 ± 0.1°C. They are used to calculate the Gibbs energy of the transfer of nicotinic acid from water into aqueous solutions of ethanol and dimethylsulfoxide. The Gibbs energy values for the transfer of the molecular and zwitterionic forms of nicotinic acid are obtained by means of UV spectroscopy. The diametrically opposite effect of the composition of binary solvents on the transfer of the molecular and zwitterionic forms of nicotinic acid is noted.

  1. Porosity and liquid absorption of cement paste

    DEFF Research Database (Denmark)

    Krus, M.; Hansen, Kurt Kielsgaard; Kunzel, H. M.

    1997-01-01

    be a slowing-down effect which is related to water because the absorption of organic liquids, such as hexane, is quite normal. Measurements of the porosity of hardened cement paste determined by helium pycnometry and water saturation show that water molecules can enter spaces in the microstructure which...... are not accessible to the smaller helium atoms. Considering the results of dilatation tests both before and after water and hexane saturation, it seems possible that a contraction of capillary pores due to moisture-related swelling of the cement gel leads to the non-linear water absorption over the square root...

  2. Determination of alpha-Tocopherol (vitamin E) in irradiated garlic by high performance liquid chromatography (HPLC); Determinacao de alpha-tocoferol em alho irradiado utilizando cromatografia liquida de alta frequencia (CLAE)

    Energy Technology Data Exchange (ETDEWEB)

    Rios, Magda Dias Goncalves; Penteado, Marilene de Vuono Camargo [Sao Paulo Univ., SP (Brazil). Faculdade de Ciencias Farmaceuticas. Dept. de Alimentos e Nutricao Experimental]. E-mail: riosmagda@hotmail.com

    2003-02-01

    The effects of {sup 60}Co ionizing radiations in doses of 0, 75, 100, 150, 200 and 250Gy on garlic, upon the {alpha}-tocopherol concentration were studied. The {alpha}-tocopherol contents were established by high performance liquid chromatography (HPLC), after direct hexane extraction from the garlic samples. The {alpha}-tocopherol was determined through normal phase column, and mobile phase was composed by hexane: iso-propyl alcohol (99:01 v/v), with 2mL/min flow rate and fluorescence detector. It is statistically shown that an irradiation dose of up to 150 Gy does not affect the garlic {alpha}-tocopherol content. (author)

  3. Untersuchungen zum atmosphärenchemischen Abbau langkettiger Aldehyde

    OpenAIRE

    Plagens, Heike

    2001-01-01

    In dieser Arbeit wurden die bimolekularen Geschwindigkeitskonstanten für die Reaktionen von Hexanal, Heptanal, Oktanal und Nonanal mit OH and Cl Radikalen bei (298 ± 2) K und (1000 ± 20) mbar experimentell bestimmt. Ebenso wurde die Chlorgeschwindigkeitskonstante für Butanal gemessen. Die Werte sind (in Einheiten von cm3 Molekül-1 s-1) in Tabelle 1 zusammengefaßt. Tabelle 1: Aldehyde kOH kCl Butanal - (2,21 ± 0,16) · 10-10 Hexan...

  4. Anti-inflammatory activity of Lippia dulcis.

    Science.gov (United States)

    Pérez, S; Meckes, M; Pérez, C; Susunaga, A; Zavala, M A

    2005-10-31

    Lippia dulcis hexane and ethanol extracts were tested for its anti-inflammatory activity in several animal models. Hexane extract showed to be inactive, but the ethanol extract at doses of 400 mg/kg produced significant inhibition of carrageenan-induced paw oedema and reduced the weight of cotton pellet-induced granuloma, moreover, the topical application of 0.5 mg/ear of this extract inhibited the edema induced with TPA by 49.13%, an effect which is of less intensity than that produced by indomethacine at the same dose.

  5. Comparison of solvent extraction and solid-phase extraction for the determination of polychlorinated biphenyls in transformer oil.

    Science.gov (United States)

    Mahindrakar, A N; Chandra, S; Shinde, L P

    2014-01-01

    Solid-phase extraction (SPE) of nine polychlorinated biphenyls (PCBs) from transformer oil samples was evaluated using octadecyl (CI8)-bonded porous silica. The efficiency of SPE of these PCBs was compared with those obtained by solvent extraction with DMSO and hexane. Average recoveries exceeding 95% for these PCBs were obtained via the SPE method using small cartridges containing 100mg of 40 pm CI8-bonded porous silica. The average recovery by solvent extraction with DMSO and hexane exceeded 83%. It was concluded that the recoveries and precision for the solvent extraction of PCBs were poorer than those for the SPE. Copyright © 2013 Elsevier Ltd. All rights reserved.

  6. Isolation And Purification Of Flavonoids From The Leaves Of Locally Produced Carica Papaya

    Directory of Open Access Journals (Sweden)

    Yahaya Mobmi Musa

    2015-08-01

    Full Text Available ABSTRACT The leaves of Carica papaya 150g was defatted with N-Hexane and extracted with Methanol. The N-Hexane exract showed the presence of Flavonoid Saponin Tannin Glycoside Anthraquinone Resin and Steroid while Methanolic extract showed the presence of Flavonoid Saponin and Resins. 6g of the Methanolic extract was chromatographed using Column chromatography over Silica gel of column 200g60-200 mesh and eluted with the solvent mixture of CH2Cl2CH3OH H2O in the ratio of 70301. The yield of the isolated Flavonoid was 0.23.

  7. Hydration of ammonia, methylamine, and methanol in amorphous solid water

    Science.gov (United States)

    Souda, Ryutaro

    2016-02-01

    Interactions of polar protic molecules with amorphous solid water (ASW) have been investigated using temperature-programmed desorption and time-of-flight secondary ion mass spectrometry. The ammonia and methylamine are incorporated into the interior of porous ASW films. They are caged by water molecules and are released during water crystallization. In contrast, the methanol-water interaction is not influenced by pores of ASW. The methanol additives tend to survive water crystallization and are released during ASW film evaporation. The hydration of n-hexane in ASW is influenced significantly by methanol additives because n-hexane is accommodated in a methanol-induced hydration shell.

  8. Defatting and Sonication Enhances Protein Extraction from Edible Insects.

    Science.gov (United States)

    Choi, Byoung Deug; Wong, Nathan A K; Auh, Joong-Hyuck

    2017-01-01

    Edible insects are attracting growing interest as a sustainable source of protein for addition to processed meat and dairy products. The current study investigated the optimal method for protein extraction from mealworm larvae ( Tenebrio molitor ), cricket adults ( Gryllus bimaculatus ), and silkworm pupae ( Bombyx mori ), for use in further applications. After defatting with n-hexane for up to 48 h, sonication was applied for 1-20 min and the protein yield was measured. All samples showed a total residual fat percentage below 1.36%, and a 35% to 94% improvement in protein yield (%). In conclusion, defatting with n-hexane combined with sonication improves the protein yield from insect samples.

  9. Synergistic Extraction of Lactic Acid with Tri-n-Octylamine and Try-n-Butylphosphate

    Energy Technology Data Exchange (ETDEWEB)

    Matsumoto, Michiaki.; Yuba, Seiji.; Kondo, Kazuo. (Doshisha University, Department of Chemical Engineering and Materials Science (Japan))

    1998-12-01

    Synergistic extraction system of lactic acid is examined to develop to in situ extractive fermentation process. The addition of try-n-butyl phosphate(TBP) to the extraction system of lactic acid(HA) with tri-n-actylamine(TOA) diluted by hexane causes a large synergism. Extraction reaction with the mixed extractant is interpreted quite well based on the formation of mixed complex, HA[center dot]TOA[center dot]2TBP. Though the addition of hexane solution containing TBP and TOA to the culture of Lactobacillus rhamnosus results in low lactate production, some lactate is produced. (author)

  10. Synergistic Extraction of Lactic Acid with Tri-n-Octylamine and Try-n-Butylphosphate

    Energy Technology Data Exchange (ETDEWEB)

    Matsumoto, Michiaki.; Yuba, Seiji.; Kondo, Kazuo. [Doshisha University, Department of Chemical Engineering and Materials Science (Japan)

    1998-12-01

    Synergistic extraction system of lactic acid is examined to develop to in situ extractive fermentation process. The addition of try-n-butyl phosphate(TBP) to the extraction system of lactic acid(HA) with tri-n-actylamine(TOA) diluted by hexane causes a large synergism. Extraction reaction with the mixed extractant is interpreted quite well based on the formation of mixed complex, HA{center_dot}TOA{center_dot}2TBP. Though the addition of hexane solution containing TBP and TOA to the culture of Lactobacillus rhamnosus results in low lactate production, some lactate is produced. (author)

  11. Design of Separation Processes with Ionic Liquids

    DEFF Research Database (Denmark)

    Peng-noo, Worawit; Kulajanpeng, Kusuma; Gani, Rafiqul

    2015-01-01

    A systematic methodology for screening and designing of Ionic Liquid (IL)-based separation processes is proposed and demonstrated using several case studies of both aqueous and non-aqueous systems, for instance, ethanol + water, ethanol + hexane, benzene + hexane, and toluene + methylcyclohexane....... The best four ILs of each mixture are [mmim][dmp], [emim][bti], [emim][etso4] and [hmim][tcb], respectively. All of them were used as entrainers in the extractive distillation. A process simulation of each system was carried out and showed a lower both energy requirement and solvent usage as compared...

  12. Chemical characterization using gas chromatography/mass spectrometry of two extracts from Phyllanthus orbicularis HBK

    International Nuclear Information System (INIS)

    Gutierrez Gaiten, Yamilet Irene; Miranda Martinez, Migdalia; Bello Alarcon, Adonis

    2011-01-01

    The objective of this paper was the chemical characterization of two extracts from Phyllanthus orbicularis HBK through gas chromatography/mass spectrometry. To this end, maceration with N-hexane and ethyl acetate was used to obtain the respective extracts. The study of the hexane extract identified 17 components in which hydrocarbonate structures prevailed, mainly cyclooctacosane. In the ethyl acetate extract, 19 compounds were detected, being the terpenoids the predominant, although the most abundant was sterol g-sitosterol. For the first time, the identified compounds are reported for this species

  13. Essential oil composition of different fractions of Piper guineense ...

    African Journals Online (AJOL)

    The oil fractions also showed variable contact toxicity on impregnated filter paper. All doses of the n-hexane fraction were very toxic to the test insect than the control, causing 100% mortality after five days of exposure. All the fractions produced a strong repellent activity against the test insect. These results suggest that P.

  14. Proceedings of the International Pyrotechnics Seminar (6th) Held at Estes Park, Colorado, 17-21 July 1978

    Science.gov (United States)

    1978-06-01

    ethylene glycols , neopentyl - glycol , 1,6-hexane-diol, and similar diols. Polyesters are generally preferred over polyethers because they are able to retain...contribute to adequate processing, mech- anical properties, and ballistics. The CT polydiethylene glycol adipate i cured with the multifunctional ERL

  15. International Symposium on Gas Kinetics (9th) Held in Bordeaux, France on 20-25 July 1986. Abstracts

    Science.gov (United States)

    1986-07-25

    versidad a Distancia, Ciudad Universitaria, 28040 Madrid. 3.M. Fiquera, J. Medina and 3.C. Rodriguez, Int de Quimica Fi sica "Rocasolano", CSIC, Serrano...inhibition. N J3 By making sensible (we hopel) assumptions about the reactivity of C 2115 towards allylic It, we estimate for 798 K and 50 Torr n-hexane

  16. Comparitive studies on antibacterial activity of Patchouli ...

    African Journals Online (AJOL)

    The growth inhibitory effect of the various solvents on Escherichia coli, Bacillus subtilis, Staphylococcus aureus and Enterobacter aerogenes were obtained and the most effective extract was the hexane extract of Patchouli compared to that of Geranium, which showed a maximum zone of inhibition (18 to 21 mm) against S.

  17. Author Details

    African Journals Online (AJOL)

    Effects of the aqueous and hexane extracts of Mondia whitei on the sexual behaviour and some fertility parameters of sexually inexperienced male rats. Abstract PDF · Vol 9, No 2 (2012) - Articles Effect of the Aqueous Extract of Justicia insularis T. Anders (Acanthaceae) on Ovarian Folliculogenesis and Fertility of Female ...

  18. Improving gasoline quality produced from MIDOR light naphtha isomerization unit

    Directory of Open Access Journals (Sweden)

    M.F. Mohamed

    2017-03-01

    Full Text Available Isomerization process became one of the best gasoline production sources, as it gives a high octane product while saving environment from pollution impacts. This paper presents a practical study that aims to improve the gasoline quality and economic income of an existing light naphtha isomerization unit used for octane improvement. The study included selecting the optimum combination of isomerization unit equipment that gives better product specifications for a specified feed. Eight scenarios were studied and simulated to predict the product specs. The original studied unit is MIDOR light naphtha isomerization unit at Alexandria-Egypt that recycles the unconverted hexane (C6. The other studied scenarios were adding fractionators for separating feed iso-pentanes, and recycling unconverted pentanes, hexanes and/or combinations of these fractionators. The results show a change in octane number of gasoline product for a specific feed. Once through process with no extra fractionators has lower octane number of 81 while that with de-iso-pentanizer–de-pentanizer and de-hexanizer produces gasoline with 92.3 octane number. Detailed economic study was done to calculate the return on investment “ROI” for each process option based on equipment, utilities, feed and product prices. Once through simple isomerization unit had the lowest ROI of 14.3% per year while the combination of De-iso-pentanizer with the De-hexanizer had the best ROI of 26.6% per year.

  19. Isolation and Characterization of Stigmasterol and Bis-(5, 7-diacetyl ...

    African Journals Online (AJOL)

    Nigerian Journal of Basic and Applied Sciences ... from the hexane fraction and a catechin glycoside, Bis-(5,7-diacetyl-catechin-4'-α- rhamnopyranoside) was isolated from the ethylacetate soluble fraction using a combination of silica gel column, gel filtration (sephadex LH-20) and preparative thin layer chromatography.

  20. 21 CFR 172.864 - Synthetic fatty alcohols.

    Science.gov (United States)

    2010-04-01

    ... syringe. 1-milliliter capacity, with 3-inch, 22-gauge needle. Volumetric flask. 5-milliliter capacity.... Pipet 100 milliliters of 1,2-dichloroethane into a 1-liter glass-stoppered volumetric flask and adjust... into a 1-liter glass-stoppered volumetric flask and adjust to volume with hexane, with mixing. n...

  1. Inhibition of growth and mycotoxins formation in moulds by marine ...

    African Journals Online (AJOL)

    ... extracts (chloroform, hexane and methanol) had no activity on the microbial growth. Mycotoxins formation in Aspergillus flavus was inhibited by the ethanolic extracts at the concentration of 5%. Key Words: Algae, antimicrobial, minimal inhibitory concentration, moulds. African Journal of Biotechnology Vol.3(1) 2004: 71-75 ...

  2. Download this PDF file

    African Journals Online (AJOL)

    Proff.Adewunmi

    locomotor activity of the rota rod test, and in the preliminary acute toxicity test, ... of certain colouring agents, and as an ingredient in cosmetic preparations ... hexanic sub-fraction of turmeric powder (10.3 g) was subjected to animal studies.

  3. Antifungal activity of olive cake extracts

    OpenAIRE

    Ghandi H. Anfoka; Khalil I. Al-Mughrabi; Talal A. Aburaj; Wesam Shahrour

    2001-01-01

    Powdered, dried olive (Olea europaea) cake was extracted with hexane, methanol and butanol. Six phenolic compounds, coumaric acid, ferulic acid, oleuropein, caffeic acid, protocatechuic acid and cinnamic acid, were isolated from these extracts after fractionation. The fractions were tested for their antifungal activity against Verticillium sp., Fusarium oxysporum, Rhizopus sp., Penicillium italicum, Rhizoctonia solani, Stemphylium solani, Cladosporium sp., Mucor sp., Colletotrichu...

  4. Thermodynamic parameters for the adsorption of volatile n-alkane ...

    African Journals Online (AJOL)

    alkanes hexane to nonane on ground dried water hyacinth (E. crassipes) root biomass were studied between 40 and 70°C column temperature using inverse gas chromatography, before and after treatment of the root biomass with mineral acid ...

  5. Organochlorine Pesticides and Degradation Products in Soil around ...

    African Journals Online (AJOL)

    The levels and compositions of organochlorine pesticides and degradation products in soil samples collected from a former formulation plant in Morogoro municipality, Tanzania, were determined. Extraction was performed by pressurized fluid extraction using n-hexane:acetone (75:25) mixture. Clean-up of extracts was ...

  6. Antioxidant Properties of Diospyros Preussi (Ebenaceae Gurke ...

    African Journals Online (AJOL)

    Erah

    2007-02-24

    Feb 24, 2007 ... Purpose: To evaluate the lipid peroxidation inhibiting and glutathione-sparing activities. (i.e., antioxidant effect) of Diospyros preussi seed oil in male Wistar albino rats. Methods: The n-hexane extract of the seed (seed oil) of Diospyros preussi (DP) was tested for its antioxidant properties against hydrogen ...

  7. The mango-saving molecule | IDRC - International Development ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Home · Resources · Stories .... They are placed head down to prevent the sap flowing from the tail from blemishing the fruit. ... Hexanal was declared harmless after successful testing on human cells, and on those of bees, green lacewings, and ...

  8. Improved Antitumoral Activity of Extracts Derived from Cultured ...

    African Journals Online (AJOL)

    Erah

    The high diversity of algae species coexisting in tropical habitats ... maintained at 37 ºC in a 5 % CO2 atmosphere with ... concentration of 0.05 %) at concentrations of. 6.25, 12.5, 25 ... methylation 1 mL of hexane: diethylether. (1:1) and 3 mL of ...

  9. Antioxidant activities and interactions of alpha- and gamma-tocopherols within canola and soybean oil emulsions

    Science.gov (United States)

    The effect of differing concentrations and ratios of alpha- and gamma-TOH on oxidative stability over time was determined by measuring the development of hydroperoxides and volatile secondary oxidation products (hexanal) within a series of oil-in-water (o/w) emulsion systems produced from both canol...

  10. Bulletin of Materials Science | News

    Indian Academy of Sciences (India)

    In this paper we report on the growth of strontianite crystals at the interface between an aqueous solution of Sr2+ ions and organic solutions of chloroform and hexane containing fatty acid/fatty amine molecules by reaction with sodium carbonate. When fatty acid was used as an additive at the interface, the crystals grown ...

  11. Fatty acid profile of fish scale of Catla catla | Prabu | African Journal ...

    African Journals Online (AJOL)

    Fish scales are useful to ichthyologists for the purposes of classification, identification, age determination and history study. The fatty acid profile of the hexane extracts of the fresh water fish scale of Catla catla were analyzed by gas chromatography. Fish scales were collected from a local fish market, Chidambaram. The fatty ...

  12. Phytochemical and Antimicrobial Screening of the Stem Bark ...

    African Journals Online (AJOL)

    acer

    A. F. Gabriel and H.O. Onigbanjo Phytochemical and Antimicrobial Screening of the Stem Bark Extracts of Pterocarpus erinaceus (Poir). 3. Table 2: Sensitivity test results of the extracts. Extracts. Organisms / Zones of Inhibition (mm). Ca. S a. Ec. Bs. Ps. OV. C. E. S. C. M. SC. Crude Methanol. -. -. 20. 20. 20. N. N. N. Hexane ...

  13. Swelling behaviour of isora/natural rubber composites in oils used

    Indian Academy of Sciences (India)

    Natural rubber/isora fibre composites were cured at various temperatures. The solvent swelling characteristics of natural rubber composites containing both untreated and alkali treated fibres were investigated in aromatic and aliphatic solvents like toluene, and -hexane. The diffusion experiments were conducted by the ...

  14. Biodiesel Production from Residual Palm Oil Contained in Spent Bleaching Earth by In Situ Trans-Esterification

    Directory of Open Access Journals (Sweden)

    A S Fahmil QRM

    2014-06-01

    Full Text Available Spent Bleaching Earth (SBE is an industrial solid waste of vegetable oil industry that has a high residual oil to be potentialy converted to biodiesel. This study aims at developing a biodiesel production process technology by utilizing residual palm oil contained in SBE and to test the use of hexane in the trans-esterification process. Optimization process was done by using the Response Surface Method (RSM. The variables studied included catalyst concentration and reaction time. On the other hand, the deoiled SBE resulted from biodiesel production was tested as an adsorbent on biodiesel purification after being reactivated. The method used in the biodiesel production included an in situ acid catalysed esterification followed by in situ base catalysed trans-esterification. The results of RSM showed that the optimum process was obtained at NaOH concentration of 1.8% and reaction time of 104.73 minutes, with a predicted response rate of 97.18% and 95.63% for validation results. The use of hexane could also increase the yield of biodiesel which was obtained on the ratio of hexane to methanol of 0.4:1 (volume of hexane: volume of methanol. On the other hand, the reactivated bleaching earth was effective as an adsorbent in biodiesel production, which was still conform with the Indonesian National Standard.

  15. Antibacterial Properties of Marine Sponges from Mauritius Waters ...

    African Journals Online (AJOL)

    Purpose: To investigate the antimicrobial activity of crude and fractionated extracts of Biemna tubulosa and Stylissa spp. thriving in Trou aux Biches lagoon, North East Mauritius. Methods: Crude extracts (methanol: dichloromethane 1:1) and fractions of Biemna tubulosa and Stylissa spp (hexane, ethyl acetate and butanol) ...

  16. Colloids in ultra-low dielectric media : surface forces and self-assembly

    NARCIS (Netherlands)

    Banerjee, S.

    2013-01-01

    This thesis aims at gaining fundamental insight on colloidal interactions in two types of apolar media, namely, liquid CO2 and (as a model for liquid CO2) n-hexane. The other components playing major roles are surfactants and water. The background of the work was

  17. Bioautography indicates the multiplicity of antifungal compounds ...

    African Journals Online (AJOL)

    AJB SERVER

    2006-09-18

    Sep 18, 2006 ... 199 active compounds, followed by methanol (189) and hexane (73). This difference is apparently not related to the sectional division of the species (Carr, 1988). Comparison of eluent systems. Lastly we determined which TLC solvent system separa- ted the highest number of active compounds (Table 27).

  18. Antibacterial, antioxidant and cytotoxic activities of extracts from the ...

    African Journals Online (AJOL)

    Unicellular green algal strains, identified as Cosmarium (Chlorophyta), were isolated from Ain-Echeffa hot spring in north Tunisia. Different extracts (methanol, hexane, acetone, acetone: methanol and water) obtained from both biomass and extracellular polysaccharides (EPS) were evaluated for their antibacterial, ...

  19. Radiolysis of triphenylarsine in a mixture of benzene and cyclohexane. [. gamma. radiation

    Energy Technology Data Exchange (ETDEWEB)

    Nazir, S B; Rai, R S [Birla Inst. of Tech. and Science, Pilani (India). Dept. of Chemistry

    1975-06-01

    A number of degassed samples of triphenylarsine were irradiated by gamma radiation in a mixture of benzene and cyclohexane. The condensable products formed were pentane, hexane, benzene and cyclohexane in cyclohexane solution containing triphenylarsine and cyclohexane in benzene in presence of triphenylarsine. When the composition of the solvent was varried by stepwise addition of benzene from 5 to 50%, the main condensable radiolytic products observed by vapour phase chromatography were hexane, : hexane and cyclohexene. No pentane was observed when benzene was present in the mixture upto 15%. However, it was detected in the presence of 20-30% benzene mixture. When the amount of benzene was 35-50% in the mixture, two isomers of hexane and hexene were also detected. A mechanism has been worked out for the formation of these compounds and protection and sensitization mechanisms have been invoked to explain the yields per 100 ev. From the kinetic analysis, it has been found out that the rate of formation of cyclohexene is much faster than rates of different products formed during gamma radiolysis and from the analysis of experimental data, sponge type protection has been postulated in this radiolytic system.

  20. Modeling vapor-liquid interfaces with the gradient theory in combination with the CPA equation of state

    DEFF Research Database (Denmark)

    Queimada, Antonio; Miqueu, C; Marrucho, IM

    2005-01-01

    and the correct phase equilibrium of water + hydrocarbon systems already obtained from CPA. In this work, preliminary studies involving the vapor-liquid interfacial tensions of some selected associating and non-associating pure components (water, ethanol, n-butane, n-pentane, n-hexane, n-heptane) are presented...

  1. Melting mechanism in monolayers of flexible rod-shaped molecules

    DEFF Research Database (Denmark)

    Hansen, Flemming Yssing; Taub, H.

    1992-01-01

    The melting of butane and hexane monolayers adsorbed on a graphite basal-plane surface has been studied by molecular-dynamics simulations and experimentally by neutron diffraction. The simulation results are qualitatively consistent with the observed diffraction patterns and suggest a general...

  2. Polyphenols content, antioxidant and antimicrobial activities of ...

    African Journals Online (AJOL)

    25 wild plants were collected from the south of Tunisia. The dried aerial parts were extracted under a continuous reflux set-up in a Soxhlet extractor with hexane, ethyl acetate, methanol and water. The extracts were screened for total phenolic content, antioxidant and antimicrobial activities. Total phenolic contents were ...

  3. Larvicidal properties of simalikalactone d from Quassia africana ...

    African Journals Online (AJOL)

    The root extract was partitioned into hexane, chloroform and ethyl acetate and the resulting extracts screened for larvicidal properties. The extracts and the fraction with the highest bioactivity were subjected to repeated column chromatography and isolated compounds evaluated for potential toxicity to An. gambiae larvae.

  4. supp23.doc

    Indian Academy of Sciences (India)

    The termination of the reaction was monitored by TLC using hexane: ethyl acetate (7:3) as eluent. After completion of the reaction, the solution was filtered to remove the catalyst. The filtrate was concentrated under reduced pressure to furnish the crude product, which was recrystallized from methanol to afford the pure ...

  5. OPTIMIZATION OF SESAME SEEDS OIL EXTRACTION OPERATING CONDITIONS USING THE RESPONSE SURFACE DESIGN METHODOLOGY

    Directory of Open Access Journals (Sweden)

    HAITHAM OSMAN

    2016-12-01

    Full Text Available This paper applies Response Surface Design (RSD to model the experimental data obtained from the extraction of sesame seeds oil using n-hexane, chloroform and acetone as solvents under different operating conditions. The results obtained revealed that n-hexane outperformed the extraction obtained using chloroform and acetone. The developed model predicted that n-hexane with a rotational speed of 547 rpm and a contact time between the solvent and seeds of 19.46 hours with solvent: seeds ratio of 4.93, yields the optimum oil extracted of 37.03 %, outperforming chloroform and acetone models that gave prediction for 4.75 and 4.21 respectively. While the maximum predictions yield for chloroform is 6.73 %, under the operating conditions of 602 rpm, and 24 hours contact time, with a ratio of solvent: seeds of 1.74. On the other hand the acetone maximum prediction is only 4.37 %, with operational conditions of 467 rpm, and 6.00 hours contact time, with a ratio of solvent: seeds of 1. It is has been found that the maximum oil extraction yield obtained from the chloroform (6.73 % and Acetone (4.37 % is much lower than that predicted by n-hexane 37.03 %.

  6. Upshot of the ripening time on biological activities, phenol content ...

    African Journals Online (AJOL)

    Anis

    2013-10-02

    Oct 2, 2013 ... was shown to inhibit free radical-induced neuronal injury in mouse cortical cultures (Wie, 2000). .... reflux with n-hexane during 4 h (18 to 22 cycles/h). Thereafter, the cellulose ...... prepared from glucose amine. Japan. J. Nutr.

  7. Wound healing properties of ointment formulations of Ocimum ...

    African Journals Online (AJOL)

    present work evaluated the phyto-constituents and wound healing properties of ointments formulated with the n-hexane crude bark extract of a plant used folklorically in wound healing, Ocimum gratissimum. The excision wound model was employed in the wound healing studies. The air-dried, size-reduced barks were ...

  8. The Optical Resolution of Chiral Tetrahedrone-type Clusters Contai- ning SCoFeM (M=Mo or W) Using High Performance Liquid Chromatography Chiral Stationary Phase

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Amylose tris (phenylcarbamate) chiral stationary phase (ATPC-CSP) was prepared and used for optical resolution of clusters 1 and 2. n-Hexane/2-propanol ( 99/1; v/v) were found to be the most suitable mobile phase on ATPC-CSP.

  9. Synthesis and Antimicrobial Activity of Some New a ...

    African Journals Online (AJOL)

    NJD

    2007-03-15

    Mar 15, 2007 ... irradiation (2 min) conditions. Thin layer chromatography. (TLC) was employed to determine ... *To whom correspondence should be addressed. E-mail: naga_raju04@yahoo.co.in. Scheme ... residue was purified by column chromatography using 60–120 mesh silica gel as adsorbent and hexane and ethyl ...

  10. Effect of Thai saraphi flower extracts on WT1 and BCR/ABL protein ...

    African Journals Online (AJOL)

    In this study, the cytotoxic effects of crude ethanolic and fractional extracts including hexane, ethyl acetate, and methanol fractions from M. siamensis flowers were investigated in order to determine their effect on WT1 expression in Molt4 and K562 cells and Bcr/Abl expression in K562 cells. Materials and Methods: The ...

  11. Phytochemical and antibacterial properties of Parkia biglobosa and ...

    African Journals Online (AJOL)

    Preliminary phytochemical screening showed that both plants had similar constituents namely cardiac glycosides, steroids, tannins and alkaloids. The thin layer chromatography of the hexane and ethanol extracts of both plants were also investigated and two of the components of the ethanol extracts of both plants were ...

  12. Preliminary evaluation of anhydrous ethanol as a solvent in the oilseed extraction of Jatropha curcas L.; Evaluacion preliminar del etanol anhidro como solvente en la extraccion de aceite de semillas de jatrofa (Jatropha curcas L.)

    Energy Technology Data Exchange (ETDEWEB)

    Brossard-Gonzalez, C.; Ferrari, R. A.; Pighinelli, A. L.; Park, K. J.

    2010-07-01

    A preliminary evaluation was performed on anhydrous ethanol as a solvent for the extraction of oil from whole Jatropha curcas L. seeds (32.24 % lipids, 16.05 % proteins), supplied from Mato Grosso, Brazil. The methodology of factorial 2k designs was followed, which included a comparison between pressing and n-hexane extraction methods. The regression model corresponding to the comparison between ethanol and n-hexane, varying extraction time, did not have lack of fit and presented an R2 of 99%. The experimental design for the pressing method, varying press rotation speed and temperature, yielded a poorly fitted linear model. The oil composition extracted with ethanol was similar to those obtained by n-hexane and by pressing. The highest yield (36.7%) was obtained using ethanol for 4 hours. The excess of extracted material was attributed to additional solubilization of impurities that could be diminished by limiting the extraction time to 1 hour. The oil extracted with ethanol and by pressing have the same color. It is presumed that the purification steps for both oils should be similar. Further studies using mixtures of ethanol with small proportions of n-hexane are suggested. (Author) 20 refs.

  13. Insecticidal activity of Jatropha curcas extracts against housefly, Musca domestica.

    Science.gov (United States)

    Chauhan, Nitin; Kumar, Peeyush; Mishra, Sapna; Verma, Sharad; Malik, Anushree; Sharma, Satyawati

    2015-10-01

    The hexane and ether extracts of leaves, bark and roots of Jatropha curcas were screened for their toxicity against different developmental stages of housefly. The larvicidal, pupicidal and adulticidal activities were analysed at various concentrations (0.78-7.86 mg/cm(2)) of hexane and ether extracts. The lethal concentration values (LC50) of hexane extract of J. curcas leaves were 3.0 and 0.27 mg/cm(2) for adult and larval stages of housefly, respectively, after 48 h. Similarly, the ether extract of leaf showed the LC50 of 2.20 and 4.53 mg/cm(2) for adult and larval stages of housefly. Least toxicity was observed with hexane root extract of J. curcas with LC50 values of 14.18 and 14.26 mg/cm(2) for adult and larvae of housefly, respectively, after 48 h. The variation in LC50 against housefly pupae was found to be 8.88-13.10 mg/cm(2) at various J. curcas extract concentrations. The GC-MS analysis of J. curcas leaf extract revealed the presence of trans-phytol (60.81 %), squalene (28.58 %), phytol (2.52 %) and nonadecanone (1.06 %) as major components that could be attributed for insecticidal activity of J. curcas extracts.

  14. Laboratory and field evaluation of medicinal plant extracts against filarial vector, Culex quinquefasciatus Say (Diptera: Culicidae)

    Science.gov (United States)

    In this study, chemical extracts of Jatropha curcas, Hyptis suaveolens, Abutilon indicum, and Leucas aspera were tested for toxicity to larvae of the filariasis vector Culex quinquefasciatus. Respective median lethal concentrations (LC50) for hexane, chloroform, ethyl acetate, and methanol extracts...

  15. Measuring Vapor Pressure with an Isoteniscope: A Hands-on Introduction to Thermodynamic Concepts

    Science.gov (United States)

    Chen, Wenqian; Haslam, Andrew J.; Macey, Andrew; Shah, Umang V.; Brechtelsbauer, Clemens

    2016-01-01

    Characterization of the vapor pressure of a volatile liquid or azeotropic mixture, and its fluid phase diagram, can be achieved with an isoteniscope and an industrial grade digital pressure sensor using the experimental method reported in this study. We describe vapor-pressure measurements of acetone and n-hexane and their azeotrope, and how the…

  16. Physico-Chemical characteristics of shea butter( Vitellaria paradoxa ...

    African Journals Online (AJOL)

    Seed oil was extracted by Soxhlet apparatus using n-hexane solvent and analysed for colour, refractive index, viscosity, oil content, acid value, peroxide value, saponification value, iodine value, ƒ¿-tocopherols and fatty acid profile. Shea oil content, colour, refractive index and viscosity ranged from 41-54%, orange to ...

  17. ​Affordable natural product reduces fruit losses, increases incomes ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Advancing science, enhancing fruit life The project uses cutting-edge science to extend and optimize the use of hexanal for pre- and post-harvest applications to ... The Tamil Nadu Agricultural University in India, the Industrial Technology Institute in Sri Lanka, and the University of Guelph in Canada will work with research ...

  18. Contribution of microwaves or ultrasonics on carvone and limonene recovery from dill fruits

    NARCIS (Netherlands)

    Esveld, D.C.; Chemat, S.

    2013-01-01

    The objective of this study is to investigate alternative preparation techniques such as microwave and ultrasound
    for the recovery and evaluation of carvone and limonene from flaked dill fruits (Anethum graveolens L.).
    The study indicates that microwave-assisted extraction using hexane is

  19. Volatile metabolites profiling of a Chinese mangrove endophytic ...

    African Journals Online (AJOL)

    Pestalotiopsis JCM2A4, an endophytic fungus originally isolated from leaves of the Chinese mangrove plant Rhizophora mucronata, produces a mixture of volatile metabolites. As determined by gas chromatography and gas chromatography/mass spectrometry (GC/GC-MS), 18 compounds representing all of the hexane ...

  20. Thaumatococcus daniellii leaves: its chemical compositions ...

    African Journals Online (AJOL)

    Methanol extract of the plant exhibited low 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity with IC50 of 615.14 μg/ml. Gas chromatography-mass spectrometry (GC-MS) characterization of n-hexane, ethylacetate and methanol extracts of T. daniellii leaves identified , thirteen and fifteen compounds, with ...

  1. Binding Constant of Amines to Water/AOT/n-Hexene Reverse Micelles. Influence of the Chemical Structure

    Directory of Open Access Journals (Sweden)

    J. J. Silber

    2000-03-01

    Full Text Available The distribution of different amines between n-hexane bulk and the micellar pseudophase of AOT reverse micelles were measured by a fluorometric method. An independent method was used to corroborate the incorporation of the amines to the interface. The effect of the amine structure on the binding constant was analysed.

  2. Antioxidant effect of Citrullus vulgaris (watermelon) extract against ...

    African Journals Online (AJOL)

    The Antioxidant effect of Citrullus Vulgaris (Watermelon) extract was evaluated against lipid oxidation in freshly caught fishes during cooking. GC-MS analysis of Hexane and total phenolic extract of Citrullus Vulgaris flesh reveals that the extracts contain 55 compounds which includes 5- hydroxymethyl furfural, ...

  3. Preparation and properties of binderless boards from Jatropha curcas L. seed cake

    NARCIS (Netherlands)

    Hidayat, H.; Keijsers, E.R.P.; Prijanto, U.; Dam, J.E.G. van; Heeres, H.J.

    The potential of Jatropha curcas L. seed cake after oil extraction (expelling of seeds followed by hexane extraction) as a raw material for binderless boards was investigated. The composition of the de-oiled seed cake was investigated using a range of techniques (proximate-, ultimate analyses,

  4. Preparation and properties of binderless boards from Jatropha curcas L. seed cake

    NARCIS (Netherlands)

    Hidayat, H.; Keijsers, E.R.P.; Prijanto, U.; Dam, van J.E.G.; Heeres, H.J.

    2014-01-01

    The potential of Jatropha curcas L. seed cake after oil extraction (expelling of seeds followed by hexane extraction) as a raw material for binderless boards was investigated. The composition of the de-oiled seed cake was investigated using a range of techniques (proximate-, ultimate analyses,

  5. Assessment of anti-inflammatory potential of Sesbania bispinosa ...

    African Journals Online (AJOL)

    Aim and objectives: Leaf extracts and fractions of S. bispinosa were evaluated for anti-inflammatory activity in mice using acute and chronic anti-inflammatory models with aspirin as a reference drug. Materials and methods: Methanol, chloroform and hexane were used to prepare leaf extracts by soxhlet extraction method, ...

  6. Synthesis, Antimicrobial and Antitubercular Activities of Some Novel ...

    African Journals Online (AJOL)

    Erah

    precoated TLC plates using hexane and ethyl acetate (1:1) as an eluent and observed under UV light. The resultant mixture was poured into ice cold water. The crude Schiff bases were washed, filtered, dried and recrystallised from ethanol. N'--benzylidene galloyl hydrazide (2a):. Yield: 73 %, Colour: Pale white, Rf value:.

  7. Osage orange (Maclura pomifera L) seed oil poly(alpha-hydroxydibutylamine) triglycerides: Synthesis and characterization

    Science.gov (United States)

    Milled Osage orange seeds (Maclura pomifera (Raf.) Schneid) were Soxhlet extracted with hexane, and portions of the extract were treated with activated carbon before solvent removal. The crude oil was winterized and degummed by centrifugation at low temperature. Decantation of the centrifuge gave an...

  8. Solid state fermentation of carinata (Brassica carinata) meal using various fungal strains to produce a protein-rich product for feed application

    Science.gov (United States)

    In this study, the efficacy of several fungal strains to reduce GLS (GLS) content and enhance protein content during solid state fermentation (SSF) of carinata meal was evaluated. Solid state fermentation of hexane extracted (HE) and cold pressed (CP) carinata meals were performed at 50% moisture co...

  9. In vitro anti-hyperglycaemic effect of glucocapparin isolated from the ...

    African Journals Online (AJOL)

    enoh

    2012-03-20

    Mar 20, 2012 ... It showed a single spot on TLC precoated silica gel 60 F254 with the solvent system 15:85 ethyl acetate/hexane. ... oxidation by the measurement of the optical density at λ = 500 nm using a spectrophotometer DREL 2400 HACH. ... It showed on thin layer chroma- tography (TLC) a spot with Rf = 0.52.

  10. Adsorption isotherms and kinetics for dibenzothiophene on activated ...

    Indian Academy of Sciences (India)

    Adsorptive desulphurization is a promising tech- nique. It is cost effective, and as ... tinct properties, is expected to improve the adsorption capa- bility for sulphur .... I.D. silica column and n-hexane as mobile phase at a flow rate 1.00 ml min. −1.

  11. Isolation of stigmast-5,24-dien-3-ol from marine brown algae Sargassum tenerrimum and its antipredatory activity

    Digital Repository Service at National Institute of Oceanography (India)

    Majik, M.S.; Adel, H.; Shirodkar, D.; Tilvi, S.; Furtado, J.

    In recent years many sterols with potent biological activity have been identified from marine sources. Here we report the isolation of stigmast-5,24-dien-3-ol (fucosterol) as a major metabolite from the bioactive hexane-fraction of Sargassum...

  12. THERMODYNAMIC PARAMETERS OF SOLUTIONS OF ...

    African Journals Online (AJOL)

    2014-06-30

    Jun 30, 2014 ... ABSTRACT. The solubility of Sildenafil citrate in some organic solvents; hexane, toluene,1-butanol and. 1,2 dichloroethane has been determined using gravimetric method over different temperature range (298.15 K to 328.15 K) at one atmospheric pressure. The modified Apelblat and.

  13. CIFSRF / IRIACC PROFILES

    International Development Research Centre (IDRC) Digital Library (Canada)

    post-harvest use, and wax coatings. They are also working on smart packaging systems using nanotechnology to incorporate hexanal into packing materials made from banana stems and other agriculture waste. Field trials will be conducted in five countries (India, Sri Lanka,. Kenya, Tanzania, and Trinidad and Tobago) to ...

  14. Pramana – Journal of Physics | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    The dielectric relaxation phenomena of rigid polar liquid molecules chloral and ethyltrichloroacetate () in benzene, -hexane and -heptane () under 4.2, 9.8 and 24.6 GHz electric fields at 30°C are studied to show the possible existence of double relaxation times 2 and 1 for rotations of the whole and the flexible ...

  15. Antibacterial activity of Sargassum polycystum C. Agardh and ...

    African Journals Online (AJOL)

    In this study, the antibacterial activity of n-hexane, dichloromethane and methanolic extracts of brown seaweeds (Phaeophyceae), Sargassum polycystum C. Agardh and Padina australis Hauck, was examined using the disc diffusion and broth microdilution methods. The bioactivity of the seaweed extracts was expressed as ...

  16. Author Details

    African Journals Online (AJOL)

    Suloon, Jacklin. Vol 12, No 6 (2015) - Articles Hexanic fraction of turmeric powder attenuates murine model of induced nociception and its possible mechanisms of action. Abstract PDF. ISSN: 0189-6016. AJOL African Journals Online. HOW TO USE AJOL... for Researchers · for Librarians · for Authors · FAQ's · More about ...

  17. Author Details

    African Journals Online (AJOL)

    Sulaiman, Mohd Roslan. Vol 12, No 6 (2015) - Articles Hexanic fraction of turmeric powder attenuates murine model of induced nociception and its possible mechanisms of action. Abstract PDF. ISSN: 0189-6016. AJOL African Journals Online. HOW TO USE AJOL... for Researchers · for Librarians · for Authors · FAQ's · More ...

  18. Toxicity of Turmeric Extracts to the Termite Reticulitermes flavipes (Blattodea: Rhinotermitidae).

    Science.gov (United States)

    Raje, Kapil R; Hughes, Gabriel P; Gondhalekar, Ameya D; Ginzel, Matthew D; Scharf, Michael E

    2015-08-01

    Turmeric is an important spice crop with documented human health benefits associated with chemicals called curcuminoids. In this study, the termite Reticulitermes flavipes (Kollar) was exposed to different solvent extracts of turmeric to investigate potential termiticidal properties. Treating termites with hexane extracts of purified lab-grade curcuminoids had no effect on termites. However, in continuous exposure assays, the LC(50) for hexane extracts of crude turmeric powder was 9.6 mg, or 1.0 mg starting material per square centimeter of filter paper substrate. These active components were soluble in a range of polar and apolar solvents, but only hexane could selectively fractionate active components away from the inactive curcuminoids. The active constituents of turmeric separated by thin layer chromatography (TLC) fluoresced in short-wave UV light but were not visible in long-wave UV light. By re-extracting TLC-separated bands in hexane and performing bioassays and gas chromatography-mass spectrometry, we demonstrated that termiticidal components of turmeric are extractable as a blend containing mainly ar-turmerone, turmerone, and curlone. This determination is consistent with findings of preceding work by other researchers that investigated insecticidal properties of turmeric in other pest insects. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  19. Phytochemical constituents and antimicrobial activity of leaf extracts ...

    African Journals Online (AJOL)

    USER

    2010-05-24

    May 24, 2010 ... conventionally used to control microbial growth and survival (Nascimento et al., ... The leaves were air-dried to crispiness in the laboratory at room temperature of 25. - 260C. ... and sequentially extracted in cold with 2 × 1L of distilled hexane, ethyl acetate ..... medicinal plants on smooth muscle. AB Abstract ...

  20. Can crystal engineering be as beneficial as micronisation and overcome its pitfalls?: A case study with cilostazol.

    Science.gov (United States)

    Sai Gouthami, Kodukula; Kumar, Dinesh; Thipparaboina, Rajesh; Chavan, Rahul B; Shastri, Nalini R

    2015-08-01

    Improvement in dissolution of the drugs having poor solubility is a challenge in pharmaceutical industry. Micronization is one technique, employed for dissolution enhancement of cilostazol, a BCS class II drug. However, the obtained micronized drug possesses poor flowability. The aim of this study was to improve the dissolution rate and flow properties of cilostazol by crystal engineering, using habit modification method and compare with micronized cilostazol bulk drug. Simulation studies were performed to predict the effect of solvents on cilostazol crystal habit. Cilostazol crystals with different habits were prepared by solvent:anti-solvent crystallization technique. SEM, FTIR, DSC, TGA and PXRD were used for solid state characterization. The results revealed that cilostazol re-crystallized from methanol-hexane system were hexagonal and ethanol-hexane system gave rods. Cilostazol engineered habits showed increased dissolution rate than unprocessed drug but similar dissolution rate when compared to micronized cilostazol. Micronized cilostazol showed a dissolution efficiency of 75.58% where as cilostazol recrystallized from methanol-hexane and ethanol-hexane systems resulted in a dissolution efficiency of 72.63% and 68.63%, respectively. In addition, crystal engineering resulted in improved flow properties of re-crystallized habits when compared to micronized form of the drug. In conclusion, crystal engineering by habit modification show potential for dissolution enhancement with an added advantage of improved flow properties over micronization technique, for poorly soluble drugs like cilostazol. Copyright © 2015 Elsevier B.V. All rights reserved.

  1. 15-00467_SI.doc

    Indian Academy of Sciences (India)

    Following the general procedure, benzylalcohol (1 mmol) was used as the alcohol species and 4-methyl benzylamine (1.2 mmol) as the amine species. The title compound was recovered as a white solid (79-88%), after column chromatography eluting with 6:4, hexane: ethyl acetate. TON: 88/79/84. 1H NMR (300.13 MHz, ...

  2. Réduction des pertes de fruits grâce à la nanotechnologie (FCRSAI ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    ... qui a démontré que l'hexanal (un composé chimique largement utilisé) peut aider à ... IDRC is pleased to announce the results of its 2017 call for proposals to ... by intensifying sexual and reproductive and adolescent health research.

  3. Heat capacity and Joule-Thomson coefficient of selected n-alkanes at 0.1 and 10 MPa in broad temperature ranges

    DEFF Research Database (Denmark)

    Regueira Muñiz, Teresa; Varzandeh, Farhad; Stenby, Erling Halfdan

    2017-01-01

    Isobaric heat capacity of six n-alkanes, i.e. n-hexane, n-octane, n-decane, n-dodecane, n-tetradecane and n-hexadecane, was determined with a Calvet type differential heat-flux calorimeter at 0.1 and 10 MPa in a broad temperature range. The measured isobaric heat capacity data were combined...

  4. Aloe plant extracts as alternative larvicides for mosquito control ...

    African Journals Online (AJOL)

    The larvicidal activity of extracts from Aloe turkanensis, Aloe ngongensis and Aloe fibrosa against the common malaria vector, Anopheles gambie, was determined. Ground Aloe leaves from the three plants were sequentially extracted with hexane, ethyl acetate, chloroform, acetone and methanol. Only the ethyl acetate ...

  5. Improvement of Biogas Production from Orange Peel Waste by Leaching of Limonene

    Directory of Open Access Journals (Sweden)

    Rachma Wikandari

    2015-01-01

    Full Text Available Limonene is present in orange peel wastes and is known as an antimicrobial agent, which impedes biogas production when digesting the peels. In this work, pretreatment of the peels to remove limonene under mild condition was proposed by leaching of limonene using hexane as solvent. The pretreatments were carried out with homogenized or chopped orange peel at 20–40°C with orange peel waste and hexane ratio (w/v ranging from 1 : 2 to 1 : 12 for 10 to 300 min. The pretreated peels were then digested in batch reactors for 33 days. The highest biogas production was achieved by treating chopped orange peel waste and hexane ratio of 12 : 1 at 20°C for 10 min corresponding to more than threefold increase of biogas production from 0.061 to 0.217 m3 methane/kg VS. The solvent recovery was 90% using vacuum filtration and needs further separation using evaporation. The hexane residue in the peel had a negative impact on biogas production as shown by 28.6% reduction of methane and lower methane production of pretreated orange peel waste in semicontinuous digestion system compared to that of untreated peel.

  6. Improvement of biogas production from orange peel waste by leaching of limonene.

    Science.gov (United States)

    Wikandari, Rachma; Nguyen, Huong; Millati, Ria; Niklasson, Claes; Taherzadeh, Mohammad J

    2015-01-01

    Limonene is present in orange peel wastes and is known as an antimicrobial agent, which impedes biogas production when digesting the peels. In this work, pretreatment of the peels to remove limonene under mild condition was proposed by leaching of limonene using hexane as solvent. The pretreatments were carried out with homogenized or chopped orange peel at 20-40°C with orange peel waste and hexane ratio (w/v) ranging from 1 : 2 to 1 : 12 for 10 to 300 min. The pretreated peels were then digested in batch reactors for 33 days. The highest biogas production was achieved by treating chopped orange peel waste and hexane ratio of 12 : 1 at 20°C for 10 min corresponding to more than threefold increase of biogas production from 0.061 to 0.217 m(3) methane/kg VS. The solvent recovery was 90% using vacuum filtration and needs further separation using evaporation. The hexane residue in the peel had a negative impact on biogas production as shown by 28.6% reduction of methane and lower methane production of pretreated orange peel waste in semicontinuous digestion system compared to that of untreated peel.

  7. Contribution to the study of rutin stability in the achenes of Tartary buckwheat (Fagopyrum tataricum)

    Czech Academy of Sciences Publication Activity Database

    Kalinová Pexová, J.; Vrchotová, Naděžda; Tříska, Jan

    2018-01-01

    Roč. 258, aug (2018), s. 314-320 ISSN 0308-8146 R&D Projects: GA MŠk(CZ) LO1415 Institutional support: RVO:86652079 Keywords : hexane * lyophilisation * methanol * quercetin * rutin-degradating enzyme * temperature Subject RIV: CE - Biochemistry OBOR OECD: Biochemistry and molecular biology Impact factor: 4.529, year: 2016

  8. screening of twenty-four south african combretum species and six ...

    African Journals Online (AJOL)

    Prof. Clement Adewunmi

    of finely ground plant material and extracting with 10 ml of acetone, hexane, ... chloroform/ethyl acetate/formic acid (5:4:1): [CEF] (intermediate polarity/acidic); benzene/- ... This figure was used as the representative of all Combretum species and ... (bottom) solvent systems and sprayed with 0.2% DPPH in methanol. Yellow ...

  9. In vitro evaluation of the antifungal activity of Sclerocarya birrea ...

    African Journals Online (AJOL)

    STORAGESEVER

    2008-10-20

    Oct 20, 2008 ... More compounds with antioxidant activity were observed in polar separation system .... finely ground leaves and rhizomes were extracted in 10 ml in each of hexane .... The chromatograms were dried for up to a week at room temperature ... compounds from the roots of S. birrea (Figure 2); how- ever, the ...

  10. Determination of persistent cyclic organochlorine residues in ...

    African Journals Online (AJOL)

    2010-07-08

    Jul 8, 2010 ... cis and trans chlordane at concentrations of up to 0.003 mg/kg, while ... able for absorption into the biological system may be lower, due ... (Fig. 1; Table 1), were purchased from Riedel-de-Haën (Seelze- ... the samples were ground first with a mortar and pestle, before .... These included: hexane (polarity.

  11. Pennycress protein isolate: Pilot plant production and application in films polymeric composites

    Science.gov (United States)

    This work scaled up the process of producing pennycress protein isolates (PPI) using 5 kg starting material (previously 100 g in bench-scale research). Defatted press cake, produced by prepressing and hexane extraction, was mixed with preheated 50 L of aqueous NaOH (pH 10) for 90 min in a jacketed k...

  12. Suitability of conophor oil for the production of aklyd resins, and ...

    African Journals Online (AJOL)

    Oil was extracted from Tetracaripidum conophorum nut (conophor plant) using solvent extraction method, with hexane as solvent. The oil obtained was used to synthesize an alkyd resin, which in turn was utilized in the production of white gloss paints and vanishes. The IR and UV analysis of the oil showed the presence of ...

  13. 2-Alquil-4-Hidroxi-Tetrahidrofuranos de la Pulpa del Aguacate

    Directory of Open Access Journals (Sweden)

    Alfonso Rivas-Gil

    2006-12-01

    Full Text Available From a hexane extract of avocado pulp (Persea americana Mill., an 1:3 mixture of 2-(heptadec-16-enyl- and 2-(heptadec-16-ynyl-4-hydroxy -tetrahydrofurans was characterized by NMR techniques. These compounds have not been previously reported from natural sources.

  14. The occurrence of selected hydrocarbons in food on sale at petrol station shops and comparison with food from other shops: a literature survey

    NARCIS (Netherlands)

    Wolf, J.M. de; Beld, C.M.B. van den; Gennart, J.-Ph.; Riley, A.J.; Urbanus, J.

    2000-01-01

    A review of reports on the occurrence of some hydrocarbons in food in relation to the sales location, with emphasis on petrol station shops, covers the principal selected hydrocarbons, i.e., volatile components of gasoline, e.g., benzene, pentane, hexane, toluene, MTBE, and xylene; relevance of

  15. Effect of Senna alata (L) Roxb (Fabaceae) Leaf Extracts on alpha ...

    African Journals Online (AJOL)

    Purpose: To investigate the inhibitory effect of S. alata leaf extracts on α-amylase and α-glucosidase, and its potential for reducing postprandial blood glucose level of rats. Methods: The α-amylase and α-glucosidase inhibitory potentials of acetone, ethylacetate and hexane extracts of S. alata were investigated by reacting ...

  16. Gas chromatography/sniffing port analysis evaluated for aroma release from rehydrated French beans (Phaseolus vulgaris).

    NARCIS (Netherlands)

    Ruth, van S.M.; Roozen, J.P.; Cozijnsen, J.L.

    1996-01-01

    The technique of gas chromatography/sniffing port analysis was evaluated for studying the release of aroma compounds from rehydrated diced French beans. The aroma compounds 2-—methylbutanal and hexanal were released at a constant rate over time. An identical selection of odour active compounds was

  17. Subchronic administration of LY354740 does not modify ketamine-evoked behavior and neuronal activity in rats

    NARCIS (Netherlands)

    Imre, Gabor; Fokkema, Dirk S.; Ter Horst, Gert J.

    2006-01-01

    Acute treatment with LY354740 {1S,2S,5R,6S-2-aminobicyclo[3.1.0]hexane-2,6-dicarboxylate monohydrate}, a potent and selective agonist for group 11 metabotropic glutamate receptors (mGlu2/3), has previously been shown to block some schizophrenia-like effects of N-methyl-D-aspartate (NMDA) receptor

  18. Chemical components of Vellozia stipitata

    International Nuclear Information System (INIS)

    Cunha Pinto, A. da; Zocher, D.H.T.; Gonzaga, L.; Pinchin, R.; Lopes, C.C.

    From the hexane extract of the root and stem of Vellozia stipitata(Family Velloziaceae), are isolated lupenone, lupeol, vellozone, 22-hydroxy-21αH-hopan-3-one and 4,5,10,11-tetrahydro-3,8,8-trimethylphenanthro [10,1-bc] pyran-9(8H)-one. (Author) [pt

  19. Effects of Defatted Jack Bean Flour and Jack Bean Protein ...

    African Journals Online (AJOL)

    This study evaluated the effects of substituting wheat flour with defatted Jack bean flour and Jack bean protein concentrate on bread quality. Jack bean flour milled from the seed nibs was defatted with n-hexane and part of the defatted flour (DJF) extracted in acid medium (pH; 4.5) for protein concentrate (JPC). Both the DJF ...

  20. In Vitro Anticholinergic and Antihistaminic Activities of Acorus ...

    African Journals Online (AJOL)

    The present investigation was aimed at determining the effects of hexane, acetone, methanol and aqueous extracts of Acorus calamus leaves (ACHE, ACAE, ACME and ACAQE) on cholinergic and histaminic system using isolated frog rectus abdominis muscle and guinea pig ileum. A dose dependent potentiation of Ach ...

  1. Transient effects caused by pulsed gas and liquid injections into low pressure plasmas

    International Nuclear Information System (INIS)

    Ogawa, D; Goeckner, M; Overzet, L; Chung, C W

    2010-01-01

    The fast injection of liquid droplets into a glow discharge causes significant time variations in the pressure, the chemical composition of the gas and the phases present (liquid and/or solid along with gas). While the variations can be large and important, very few studies, especially kinetic studies, have been published. In this paper we examine the changes brought about in argon plasma by injecting Ar (gas), N 2 (gas) hexane (gas) and hexane (liquid droplets). The changes in the RF capacitively coupled power (forward and reflected), electron and ion density (n e , n i ), electron temperature (T e ) and optical emissions were monitored during the injections. It was found that the Ar injection (pressure change only) caused expected variations. The electron temperature reduced, the plasma density increased and the optical emission intensity remained nearly constant. The N 2 and hexane gas injections (chemical composition and pressure changes) also followed expected trends. The plasma densities increased and electron temperature decreased while the optical emissions changed from argon to the injected gas. These all serve to highlight the fact that the injection of evaporating hexane droplets in the plasma caused very little change. This is because the number of injected droplets is too small to noticeably affect the plasma, even though the shift in the chemical composition of the gas caused by evaporation from those same droplets can be very significant. The net conclusion is that using liquid droplets to inject precursors for low pressure plasmas is both feasible and controllable.

  2. Alternative Medicines for HIV/AIDS in Resource-Poor Settings ...

    African Journals Online (AJOL)

    HP

    [3,4], Rwanda [5], South Africa [6-8], Sudan [9],. Tanzania [1,10] ... and holistic health care system that has been in existence for ... the treatment and management of HIV/AIDS opportunistic ..... evaluate for phytochemical safety and ... activities of hexane extracts from some Asian ... J Appl Industrial Sci 2013; 1(3): 49-53. 27.

  3. Magnetic self-assembly for the synthesis of magnetically exchange coupled MnBi/Fe–Co composites

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Xia [Department of Chemical and Biological Engineering and MINT Center, The University of Alabama, Tuscaloosa, AL 35487 (United States); Hong, Yang-Ki, E-mail: ykhong@eng.ua.edu [Department of Electrical and Computer Engineering and MINT Center, The University of Alabama, Tuscaloosa, AL 35487 (United States); Park, Jihoon; Lee, Woncheol [Department of Electrical and Computer Engineering and MINT Center, The University of Alabama, Tuscaloosa, AL 35487 (United States); Lane, Alan M. [Department of Chemical and Biological Engineering and MINT Center, The University of Alabama, Tuscaloosa, AL 35487 (United States); Cui, Jun [Energy and Environment Directorate, Pacific Northwestern National Laboratory, Richland, WA 99354 (United States)

    2015-11-15

    Exchange coupled hard/soft MnBi/Fe–Co core/shell structured composites were synthesized using a magnetic self-assembly process. MnBi particles were prepared by arc-melting, and Fe–Co nanoparticles were synthesized by an oleic acid assisted chemical reduction method. Grinding a mixture of micron-sized MnBi and Fe–Co nanoparticles in hexane resulted in MnBi/Fe–Co core/shell structured composites. The MnBi/Fe–Co (95/5 wt%) composites showed smooth magnetic hysteresis loops, enhanced remanent magnetization, and positive values in the ΔM curve, indicating exchange coupling between MnBi and Fe–Co particles. - Graphical abstract: Both MnBi and Fe–Co particles were dispersed in hexane for grinding. Because of the oleic acid used during the Fe–Co nanoparticle synthesis, they could be well dispersed in hexane. During the grinding, the size of MnBi particles was decreased, hexane was evaporated, and the Fe–Co nanoparticles were concentrated in the solvent and magnetically attracted by MnBi particles, forming a core/shell structure. - Highlights: • Exchange coupled MnBi/Fe–Co composites are synthesized through magnetic selfassembly. • Magnetic exchange coupling is demonstrated by smooth magnetic hysteresis loops, enhanced remanent magnetization, and dominant positive peak in the ΔM curve. • The experimental results in magnetic properties are close to the theoretical calculation results.

  4. A Simple Molecular Dynamics Lab to Calculate Viscosity as a Function of Temperature

    Science.gov (United States)

    Eckler, Logan H.; Nee, Matthew J.

    2016-01-01

    A simple molecular dynamics experiment is described to demonstrate transport properties for the undergraduate physical chemistry laboratory. The AMBER package is used to monitor self-diffusion in "n"-hexane. Scripts (available in the Supporting Information) make the process considerably easier for students, allowing them to focus on the…

  5. Larvicidal, pupicidal and insecticidal activities of Cosmos bipinnatus ...

    African Journals Online (AJOL)

    Purpose: To evaluate the larvicidal, pupicidal and insecticidal activities of Cosmos bipinnatus, Foenuculum vulgare and Tagetes minuta leaf extracts against Culex quinquefasciatus mosquitoes. Methods: The leaves of the plants were extracted with distilled water, ethanol (95 %), and hexane and the extracts screened for ...

  6. The Hypolipidaemic Effects of the Partially Purified “Hypoglycaemic ...

    African Journals Online (AJOL)

    The results indicated that the aqueous leaf extract caused significant (P<0.05) decrease in triacylglycerol (14 %), LDL-cholesterol (16 %), VLDL-cholesterol (19 %) and atherogenic index (45 %). The hexane fraction of the aqueous extract which was reported to possess significant hypoglycaemic effect caused significant ...

  7. Antioxidant activity of extracts from the bark of Chamaecyparis lawsoniana (A. Murrary) Parl.

    Science.gov (United States)

    Heng Gao; Todd F. Shupe; Chung Y. Hse; Thomas L. Eberhardt

    2006-01-01

    The bark of Chamaecyparis lawsoniana (A. Murray) Parl. was extracted with methanol and sequentially partitioned with n-hexane, ethyl acetate, n-butanol and deionized water. The antioxidant activities of the four extracts were evaluated using the DPPH• and ABTS+• methods. The total phenolic...

  8. Ovicidal activity of Ageratina adenophora (Family: Asteraceae) against dengue vector, Aedes aegypti (Diptera: Culicidae)

    Science.gov (United States)

    To determine the ovicidal efficacy of different solvent leaf extracts of Ageratina adenophora against dengue vector Aedes aegypti . Methods: The ovicidal efficacy of the crude leaf extracts of A. adenophora with five different solvents (hexane, benzene, chloroform, ethyl acetate, methanol) and was ...

  9. High regioselective acetylation of vitamin A precursors using lipase ...

    African Journals Online (AJOL)

    The effect of different reaction parameters was explored on the acylation of primary hydroxyl group of 1,6-diol by lipase B from Candida antarctica catalysis in organic solvent. First, the effect of the organic solvents was investigated, and the highest conversion rate was obtained in n-hexane. Then, the effect of the acyl donor ...

  10. Proceedings of the Twelfth Conference on Environmental Toxicology 3, 4 and 5 November 1981

    Science.gov (United States)

    1982-04-01

    aTentative assignments are Compound A = n-heptane, B=methylcyclohexane, C=2,5-.dimethylhexane, D=toluene, E= XTHDCPD isomer of dicyclopentadiene. b...2.5-dimethyl- hexane, C = toluene, D = XTHDCPD isomer of dicyclopentadiene. TABLE 6. PHOTOLYSIS OF JP-4 IN WATER Fuel Component Concentration (mg

  11. Evaluation of food grade solvents for lipid extraction and impact of storage temperature on fatty acid composition of edible seaweeds Laminaria digitata (Phaeophyceae) and Palmaria palmata (Rhodophyta).

    Science.gov (United States)

    Schmid, Matthias; Guihéneuf, Freddy; Stengel, Dagmar B

    2016-10-01

    This study evaluated the impact of different food- and non-food grade extraction solvents on yield and fatty acid composition of the lipid extracts of two seaweed species (Palmaria palmata and Laminaria digitata). The application of chloroform/methanol and three different food grade solvents (ethanol, hexane, ethanol/hexane) revealed significant differences in both, extraction yield and fatty acid composition. The extraction efficiency, in terms of yields of total fatty acids (TFA), was in the order: chloroform/methanol>ethanol>hexane>ethanol/hexane for both species. Highest levels of polyunsaturated fatty acids (PUFA) were achieved by the extraction with ethanol. Additionally the effect of storage temperature on the stability of PUFA in ground and freeze-dried seaweed biomass was investigated. Seaweed samples were stored for a total duration of 22months at three different temperatures (-20°C, 4°C and 20°C). Levels of TFA and PUFA were only stable after storage at -20°C for the two seaweed species. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Composição química e atividades biológicas das folhas de Cynara scolymus L. (alcachofra cultivada no Brasil Chemical composition and biological activities of the leaves of Cynara scolymus L. (artichoke cultivated in Brazil

    Directory of Open Access Journals (Sweden)

    Vânia Floriani Noldin

    2003-05-01

    Full Text Available The present paper describes the chemical composition and biological activities of artichoke cultivated in Brazil. Our studies demonstrated that glycosyl flavonoids (cynaroside and scolymoside, are the major constituents, along with cynaropicrin, a sesquiterpene lactone, and the triterpene lupeol. Cynarin, which is the main compound described for artichoke, was detected in very low concentration. Hexanic fraction exhibited considerable cytotoxicity and diuretic activities.

  13. Browse Title Index

    African Journals Online (AJOL)

    Items 6201 - 6250 of 11090 ... Byong Tae Jeon, KyoungHoon Kim, Sung Jin Kim, Na Yeon Kim, Jae Hyun Park, Dong Hyun Kim, Mi Rae Oh, Sang Ho Moon. Vol 10, No 65 (2011), In vitro activity of certain antimicrobial agents in combination with Augouardia letestii hexane extracts against methicillin-resistant Staphylococcus ...

  14. An efficient catalytic reductive amination: A facile one-pot access to ...

    Indian Academy of Sciences (India)

    An efficient catalytic reductive amination: A facile one-pot access to ... itors and in the manufacture of detergents and plastics.1 ... ammoniaborane/Ti(OiPr)4,5e ... demonstrated the first method for synthesis of 1,2- ... and column chromatography (Silica gel, n-hexane/ethyl .... supporting information at www.ias.ac.in/chemsci.

  15. A new ester coumarin from Ferula Persica wild, indigenous to Iran.

    Science.gov (United States)

    Razavi, Seyed Mehdi; Janani, Mehrnoush

    2015-01-01

    Ferula persica wild (Apiaceae) is a perennial herb indigenous to Iran. It has been used in folk medicine for treatment of diabetes, lowering of blood pressure and for antispasmodic, carminative, laxative and expectorant effects in central Iran. Dried ground roots of F. persica (150 g) were extracted sequentially with n-hexane, dichloromethane and methanol (MeOH), 500 ml each, using a Soxhlet apparatus. The n-hexane extract of the roots (3 g) was subjected to vacuum liquid chromatography on silica gel, eluting with solvent mixtures of increasing polarity: 100% n-hexane-ethyl acetate (EtOAc), to yield a number of fractions, Fraction 4 (80% EtOAc in n-hexane) was further analysed by preparative TLC (mobile phase was 12% acetone in chloroform) to yield a coumarin ester (10.1 mg, Rf = 0.31, blue florescent). The structure of the isolated compound was elucidated by spectroscopic means. The compound is 7-O-(4,8,12 -trihydroxy-4,8,12-trimethyl-tridecanoyl)-coumarin, named, ferulone C as a new natural product.

  16. Extraction and characterization of seed oil from naturally-grown Chinese tallow trees

    Science.gov (United States)

    Xiao-Qin Yang; Hui Pan; Tao Zeng; Todd F. Shupe; Chung-Yun Hse

    2013-01-01

    Seeds were collected from locally and naturally grown Chinese tallow trees (CTT) and characterized for general physical and chemical properties and fatty acid composition of the lipids. The effects of four different solvents (petroleum ether, hexane, diethyl ether, and 95 % ethanol) and two extraction methods (supercritical carbon dioxide (SC-CO2) and conventional...

  17. A Facile Conversion of Alcohols to Esters Mediated by Potassium Ferrate

    OpenAIRE

    Kooti, M.; Tarassoli, A.; Javadi, H. H.; Jorfi, M.

    2008-01-01

    Potassium ferrate in the presence of copper(II) sulfate pentahydrate can convert 1-phenyl ethanol, 4-chloro-1-phenyl ethanol and 2-phenyl ethanol into ester products with good or excellent yields.The reactions have been carried out in n-hexane at room temprature.The effect of other metal salts, as activators, have been also examined instead of copper sulfate.

  18. Tetramethyl-O-scutellarin isolated from peels of immature Shiranuhi ...

    African Journals Online (AJOL)

    Purpose: To investigate the anti-inflammatory activity of the ethanol extract of the immature fruit of a citrus, Shiranuhi, and to identify the active ingredient. Methods: The immature Shiranuhi peel was extracted with 80 % ethanol, and the extract was fractionated with solvents (n-hexane, ethyl acetate and n-butanol) to afford ...

  19. Towards the rational design of novel drugs based on solubility, partitioning/distribution, biomimetic permeability and biological activity exemplified by 1,2,4-thiadiazole derivatives

    DEFF Research Database (Denmark)

    Volkova, T. V.; Terekhova, I. V.; Silyukov, O. I.

    2017-01-01

    -octanol/buffer (pH 7.4) and 1-hexane/buffer (pH 7.4) immiscible phases as model systems imitating the gastrointestinal tract epithelium and the blood-brain barrier were determined. Permeation experiments the new Permeapad™ barrier using Franz diffusion cells were conducted and the apparent permeability...

  20. Carbonaceous species (coke) characterization in zeolites by solid state {sup 13} C NMR; Caracterizacao de especies carbonaceas (coque) em zeolitos por RMN de {sup 13} C estado solido (CP/MAS)

    Energy Technology Data Exchange (ETDEWEB)

    Mota, Claudio J.A.; Menezes, Sonia C [PETROBRAS, Rio de Janeiro, RJ (Brazil). Centro de Pesquisas

    1992-12-31

    This work applies solid state {sup 13} C NMR for characterization of carbonaceous species (coke) deposited on zeolites after contact with n-hexane at 370 deg C. The results have shown two types of carbon: saturated (sp{sup 3}) and unsaturated (sp{sup 2}) 4 refs., 4 tabs.