WorldWideScience

Sample records for chemical compounds

  1. Public chemical compound databases.

    Science.gov (United States)

    Williams, Anthony J

    2008-05-01

    The internet has rapidly become the first port of call for all information searches. The increasing array of chemistry-related resources that are now available provides chemists with a direct path to the information that was previously accessed via library services and was limited by commercial and costly resources. The diversity of the information that can be accessed online is expanding at a dramatic rate, and the support for publicly available resources offers significant opportunities in terms of the benefits to science and society. While the data online do not generally meet the quality standards of manually curated sources, there are efforts underway to gather scientists together and 'crowdsource' an improvement in the quality of the available data. This review discusses the types of public compound databases that are available online and provides a series of examples. Focus is also given to the benefits and disruptions associated with the increased availability of such data and the integration of technologies to data mine this information.

  2. CHEMICAL COMPOUNDS FOR METAL SHAPING

    Science.gov (United States)

    ALLOYS, *CHEMICAL MILLING, *METALS, *REFRACTORY MATERIALS, AIRCRAFT, ALUMINUM ALLOYS, CARBOXYMETHYLCELLULOSE , CHEMICALS, CHROMIUM ALLOYS, GELS, HEAT...RESISTANT ALLOYS, MATERIALS, MOLYBDENUM ALLOYS, NICKEL ALLOYS, NIOBIUM, POROUS MATERIALS, PROCESSING, PRODUCTION , SOLIDS, SOLUTIONS(MIXTURES), STAINLESS STEEL, STEEL, STRUCTURES, TANTALUM, TITANIUM ALLOYS, VANADIUM ALLOYS.

  3. Quantum chemical studies of estrogenic compounds

    Science.gov (United States)

    Quantum chemical methods are potent tools to provide information on the chemical structure and electronic properties of organic molecules. Modern computational chemistry methods have provided a great deal of insight into the binding of estrogenic compounds to estrogenic receptors (ER), an important ...

  4. Web-accessible Chemical Compound Information

    OpenAIRE

    Roth, Dana L

    2008-01-01

    Web-accessible chemical compound information resources are widely available. In addition to fee-based resources, such as SciFinder Scholar and Beilstein, there is a wide variety of freely accessible resources such as ChemSpider and PubChem. The author provides a general description of various fee-based and free chemical compound resources. The free resources generally offer an acceptable alternative to fee-based resources for quick retrieval. It is assumed that readers will be familiar with ...

  5. Chemical effect on diffusion in intermetallic compounds

    Science.gov (United States)

    Chen, Yi-Ting

    With the trend of big data and the Internet of things, we live in a world full of personal electronic devices and small electronic devices. In order to make the devices more powerful, advanced electronic packaging such as wafer level packaging or 3D IC packaging play an important role. Furthermore, ?-bumps, which connect silicon dies together with dimension less than 10 ?m, are crucial parts in advanced packaging. Owing to the dimension of ?-bumps, they transform into intermetallic compound from tin based solder after the liquid state bonding process. Moreover, many new reliability issues will occur in electronic packaging when the bonding materials change; in this case, we no longer have tin based solder joint, instead, we have intermetallic compound ?-bumps. Most of the potential reliability issues in intermetallic compounds are caused by the chemical reactions driven by atomic diffusion in the material; thus, to know the diffusivities of atoms inside a material is significant and can help us to further analyze the reliability issues. However, we are lacking these kinds of data in intermetallic compound because there are some problems if used traditional Darken's analysis. Therefore, we considered Wagner diffusivity in our system to solve the problems and applied the concept of chemical effect on diffusion by taking the advantage that large amount of energy will release when compounds formed. Moreover, by inventing the holes markers made by Focus ion beam (FIB), we can conduct the diffusion experiment and obtain the tracer diffusivities of atoms inside the intermetallic compound. We applied the technique on Ni3Sn4 and Cu3Sn, which are two of the most common materials in electronic packaging, and the tracer diffusivities are measured under several different temperatures; moreover, microstructure of the intermetallic compounds are investigated to ensure the diffusion environment. Additionally, the detail diffusion mechanism was also discussed in aspect of diffusion

  6. Antitumor activity of chemical modified natural compounds

    Directory of Open Access Journals (Sweden)

    Marilda Meirelles de Oliveira

    1991-01-01

    Full Text Available Search of new activity substances starting from chemotherapeutic agents, continously appears in international literature. Perhaps this search has been done more frequently in the field of anti-tumor chemotherapy on account of the unsuccess in saving advanced stage patients. The new point in this matter during the last decade was computer aid in planning more rational drugs. In near future "the accessibility of supercomputers and emergence of computer net systems, willopen new avenues to rational drug design" (Portoghese, P. S. J. Med. Chem. 1989, 32, 1. Unknown pharmacological active compounds synthetized by plants can be found even without this eletronic devices, as tradicional medicine has pointed out in many contries, and give rise to a new drug. These compounds used as found in nature or after chemical modifications have produced successful experimental medicaments as FAA, "flavone acetic acid" with good results as inibitors of slow growing animal tumors currently in preclinical evaluation for human treatment. In this lecture some international contributions in the field of chemical modified compounds as antineoplasic drugs will be examined, particularly those done by Brazilian researches.

  7. [Studies on chemical compounds of Chlorella sorokiniana].

    Science.gov (United States)

    Zhang, Ling; Liu, Ping-huai; Wu, Jiao-na; Yang, Guo-fu; Suo, Yang-yang; Luo, Ning; Chen, Chen

    2015-04-01

    Chemical constituents of Chlorella sorokiniana were isolated and purified by repeated column chromatographies, over silicagel and Sephadex LH-20. Their structures were identified on the basis of physicochemical properties and spectroscopic data analysis. Five compounds were obtained from the petroleum ether extract of Chlorella sorokiniana, and their structures were identified as (22E, 24R)-5alpha, 3beta-epidioxiergosta-6, 22-dien-3beta-ol(1),(24S)-ergosta-7-en-3beta-ol(2), loliolide(3), stigmasta-7,22-dien-3beta,5alpha,6alpha-triol(4), and 3beta-hydroxy-5alpha,6alpha-epoxy-7-megastigmen-9-one(5). The main liposoluble fractions from Chlorella sorokiniana maiuly contain fatty acids, alkyl acids and olefine acids. Components 1-5 were isolated from the genus Chlorella for the first time.

  8. Chemical compound navigator: a web-based chem-BLAST, chemical taxonomy-based search engine for browsing compounds.

    Science.gov (United States)

    Prasanna, M D; Vondrasek, Jiri; Wlodawer, Alexander; Rodriguez, H; Bhat, T N

    2006-06-01

    A novel technique to annotate, query, and analyze chemical compounds has been developed and is illustrated by using the inhibitor data on HIV protease-inhibitor complexes. In this method, all chemical compounds are annotated in terms of standard chemical structural fragments. These standard fragments are defined by using criteria, such as chemical classification; structural, chemical, or functional groups; and commercial, scientific or common names or synonyms. These fragments are then organized into a data tree based on their chemical substructures. Search engines have been developed to use this data tree to enable query on inhibitors of HIV protease (http://xpdb.nist.gov/hivsdb/hivsdb.html). These search engines use a new novel technique, Chemical Block Layered Alignment of Substructure Technique (Chem-BLAST) to search on the fragments of an inhibitor to look for its chemical structural neighbors. This novel technique to annotate and query compounds lays the foundation for the use of the Semantic Web concept on chemical compounds to allow end users to group, sort, and search structural neighbors accurately and efficiently. During annotation, it enables the attachment of "meaning" (i.e., semantics) to data in a manner that far exceeds the current practice of associating "metadata" with data by creating a knowledge base (or ontology) associated with compounds. Intended users of the technique are the research community and pharmaceutical industry, for which it will provide a new tool to better identify novel chemical structural neighbors to aid drug discovery.

  9. Fate modelling of chemical compounds with incomplete data sets

    DEFF Research Database (Denmark)

    Birkved, Morten; Heijungs, Reinout

    2011-01-01

    Impact assessment of chemical compounds in Life Cycle Impact Assessment (LCIA) and Environmental Risk Assessment (ERA) requires a vast amount of data on the properties of the chemical compounds being assessed. These data are used in multi-media fate and exposure models, to calculate risk levels...... in an approximate way. The idea is that not all data needed in a multi-media fate and exposure model are completely independent and equally important, but that there are physical-chemical and biological relationships between sets of chemical properties. A statistical model is constructed to underpin this assumption...

  10. Antifoaming effect of chemical compounds in manure biogas reactors

    DEFF Research Database (Denmark)

    Kougias, Panagiotis; Tsapekos, Panagiotis; Boe, Kanokwan;

    2013-01-01

    ), siloxanes (polydimethylsiloxane) and ester (tributylphosphate) were found to be the most efficient compounds to suppress foam. The efficiency of antifoamers was dependant on their physicochemical properties and greatly correlated to their chemical characteristics for dissolving foam. The antifoamers were...

  11. Malaria Parasite Metabolic Pathways (MPMP) Upgraded with Targeted Chemical Compounds

    KAUST Repository

    Ginsburg, Hagai

    2015-10-31

    Malaria Parasite Metabolic Pathways (MPMP) is the website for the functional genomics of intraerythrocytic Plasmodium falciparum. All the published information about targeted chemical compounds has now been added. Users can find the drug target and publication details linked to a drug database for further information about the medicinal properties of each compound.

  12. Isolation and Purification Chemical Compound from Melissa officinalis

    Directory of Open Access Journals (Sweden)

    Jamal A Nasser

    2014-01-01

    Full Text Available A chemical study was done on the leaves of Melissa officinalis. The separations of the chemical components were carried out by different chromatographic techniques and their structures were elucidated by spectroscopic method including nuclear magnetic resonance as well as gas chromatography-mass spectrometry. Three compounds were isolated and identified as friedoolean-7-one , stigmasterol and betulinic acid.

  13. Effect of chemical degradation on fluxes of reactive compounds

    Directory of Open Access Journals (Sweden)

    J. Rinne

    2011-12-01

    Full Text Available In the analyses of VOC fluxes measured above plant canopies, one usually assumes the flux above canopy to equal the emission at the surface. Thus one assumes the chemical degradation to be much slower than the turbulent transport. We used a stochastic Lagrangian transport model in which the chemical degradation was described as first order decay in order to study the effect of the chemical degradation on above canopy fluxes of chemically reactive species. With the model we explored the sensitivity of the ratio of the above canopy flux to the surface emission on several parameters such as chemical lifetime of the compound, friction velocity, stability, and canopy density. Our results show that friction velocity and chemical lifetime affected the loss during transport the most. The canopy density had a significant effect if the chemically reactive compound was emitted from the forest floor. We used the results of the simulations together with oxidant data measured during HUMPPA-COPEC-2010 campaign at a Scots pine site to estimate the effect of the chemistry on fluxes of three typical biogenic VOCs, isoprene, α-pinene, and β-caryophyllene. Of these, the chemical degradation had a~major effect on the fluxes of the most reactive species β-caryophyllene, while the fluxes of α-pinene were affected during nighttime. For these two compounds representing the mono- and sesquiterpenes groups, the effect of chemical degradation had also a significant diurnal cycle with the highest chemical loss at night. The different day and night time loss terms need to be accounted for, when measured fluxes of reactive compounds are used to reveal relations between primary emission and environmental parameters.

  14. Research of the chemical compound of the Haloxylon persicum

    Directory of Open Access Journals (Sweden)

    G. Maksytbek

    2012-12-01

    Full Text Available Studying of a chemical compound of an elevated part of a plant of a sort a Haloxylon (H.persicum East Kazakhstan prepared in the Altay range. Are quantitatively defined amino- and organic acids, carbohydrates, flovonoids, coumarins, alkaloids. The mineral structure of the cindery rest is defined. The scheme of allocation and separation of individual bonds with use of classical methods of a chromatography is developed. Identification of individual substances is spent by chemical and physical and chemical methods of the analysis.

  15. Antifungal chemical compounds identified using a C. elegans pathogenicity assay.

    Directory of Open Access Journals (Sweden)

    Julia Breger

    2007-02-01

    Full Text Available There is an urgent need for the development of new antifungal agents. A facile in vivo model that evaluates libraries of chemical compounds could solve some of the main obstacles in current antifungal discovery. We show that Candida albicans, as well as other Candida species, are ingested by Caenorhabditis elegans and establish a persistent lethal infection in the C. elegans intestinal track. Importantly, key components of Candida pathogenesis in mammals, such as filament formation, are also involved in nematode killing. We devised a Candida-mediated C. elegans assay that allows high-throughput in vivo screening of chemical libraries for antifungal activities, while synchronously screening against toxic compounds. The assay is performed in liquid media using standard 96-well plate technology and allows the study of C. albicans in non-planktonic form. A screen of 1,266 compounds with known pharmaceutical activities identified 15 (approximately 1.2% that prolonged survival of C. albicans-infected nematodes and inhibited in vivo filamentation of C. albicans. Two compounds identified in the screen, caffeic acid phenethyl ester, a major active component of honeybee propolis, and the fluoroquinolone agent enoxacin exhibited antifungal activity in a murine model of candidiasis. The whole-animal C. elegans assay may help to study the molecular basis of C. albicans pathogenesis and identify antifungal compounds that most likely would not be identified by in vitro screens that target fungal growth. Compounds identified in the screen that affect the virulence of Candida in vivo can potentially be used as "probe compounds" and may have antifungal activity against other fungi.

  16. Three Packets of Minerals of the Periodic Table of Chemical Elements and Chemical Compounds

    CERN Document Server

    Labushev, Mikhail M

    2013-01-01

    The concepts of alpha- and beta-packets of the periodic table of chemical elements and chemical compounds are defined. The first of the 47 minerals alpha-packets is composed. In it all minerals are arranged in increasing Iav index of proportionality of atomic weights of composing chemical elements, the same way as chemical elements are located in increasing atomic weights in the Periodic table. The packet includes 93 known minerals and two compounds - N2O5 and CO2 - being actually minerals. Beta-packet of oxides and hydroxides minerals includes 88 known minerals and five chemical compounds - N2O5, CO2, CO, SO3 and SO2. Two minerals of the packet have not been determined yet. Besides, beta-packet of minerals with sulfur, selenium or arsenic is composed, with one mineral not defined yet. The results of the calculations can be used for further development of the Periodic Table of Chemical Elements and Chemical Compounds and their properties investigation.

  17. Antifoaming effect of chemical compounds in manure biogas reactors.

    Science.gov (United States)

    Kougias, P G; Tsapekos, P; Boe, K; Angelidaki, I

    2013-10-15

    A precise and efficient antifoaming control strategy in bioprocesses is a challenging task as foaming is a very complex phenomenon. Nevertheless, foam control is necessary, as foam is a major operational problem in biogas reactors. In the present study, the effect of 14 chemical compounds on foam reduction was evaluated at concentration of 0.05%, 0.1% and 0.5% v/v(sample), in raw and digested manure. Moreover, two antifoam injection methods were compared for foam reduction efficiency. Natural oils (rapeseed and sunflower oil), fatty acids (oleic, octanoic and derivative of natural fatty acids), siloxanes (polydimethylsiloxane) and ester (tributylphosphate) were found to be the most efficient compounds to suppress foam. The efficiency of antifoamers was dependant on their physicochemical properties and greatly correlated to their chemical characteristics for dissolving foam. The antifoamers were more efficient in reducing foam when added directly into the liquid phase rather than added in the headspace of the reactor.

  18. GPU accelerated chemical similarity calculation for compound library comparison.

    Science.gov (United States)

    Ma, Chao; Wang, Lirong; Xie, Xiang-Qun

    2011-07-25

    Chemical similarity calculation plays an important role in compound library design, virtual screening, and "lead" optimization. In this manuscript, we present a novel GPU-accelerated algorithm for all-vs-all Tanimoto matrix calculation and nearest neighbor search. By taking advantage of multicore GPU architecture and CUDA parallel programming technology, the algorithm is up to 39 times superior to the existing commercial software that runs on CPUs. Because of the utilization of intrinsic GPU instructions, this approach is nearly 10 times faster than existing GPU-accelerated sparse vector algorithm, when Unity fingerprints are used for Tanimoto calculation. The GPU program that implements this new method takes about 20 min to complete the calculation of Tanimoto coefficients between 32 M PubChem compounds and 10K Active Probes compounds, i.e., 324G Tanimoto coefficients, on a 128-CUDA-core GPU.

  19. Chemical stability of extemporaneously compounded omeprazole formulations: a comparison of two methods of compounding.

    Science.gov (United States)

    Garg, Sanjay; Svirskis, Darren; Al-Kabban, Majid; Farhan, Samer; Komeshi, Mohammed; Lee, Jacky; Liu, Quincy; Naidoo, Sacha; Kairuz, Therese

    2009-01-01

    Liquid preparations of omeprazole are compounded extemporaneously for patients who cannot tolerate or have difficulty with tablets or capsules, such as those with a nasogastric tube or jejunal or feeding tube, those with a swallowing disorder, and young children and the elderly. Recommendations for preparation of a liquid from the enteric-coated pellets of omeprazole capsules are available in the literature. The pellets are dissolved in a sodium bicarbonate solution; shaking is recommended to aid dissolution. Apparently some pharmacists crush the pellets to speed up the compounding process. The aim of this study was to investigate the chemical stability of omeprazole in extemporaneously compounded liquids prepared by the grinding and shaking methods. A high-performance liquid chromatographic method was developed for evaluation of chemical stability. Samples were stored at 2 deg C (refrigerated conditions) or 25 deg C/60% relative humidity and assayed for drug concentration at 0, 1, 2, 4, and 8 weeks. The method of preparation affected the chemical stability of omeprazole when stored at 25 deg C/60% relative humidity; it was stable for 4 weeks if prepared by the shaking method, but for only 1 week if prepared by the grinding method. For both methods, the suspension was stable for 8 weks if stored under refrigerated conditions. It is recommended that the shaking method be employed for extemporaneously compounded omeprazole suspensions, and that the prepared suspension be stored in the refrigerator.

  20. Chemical metabolism of medicinal compounds from natural botanicals.

    Science.gov (United States)

    Lu, Q; Jiang, J-G

    2012-01-01

    Traditional Chinese medicine (TCM) and its natural products are complex mixtures containing hundreds of chemically different constituents but only a few components are responsible for the pharmacological effects and bioactivities. In order to clarify the functional mechanism of active compounds, the studies on metabolism are of great significance and necessity. Previously, research mainly focused on the aspect of pharmacokinetics, however in recent years, chemical metabolism of active compounds has drawn increasing attention. Researches on the chemical metabolism of single phytochemicals help to understand the transformation process in vivo and mechanism of action, also contribute to pharmacodynamics and toxicology studies and new drug development. In the present paper, the chemical metabolism of nine categories of phytochemicals was reviewed. This review focused on pharmacological action, metabolic characteristics, metabolic pathways, metabolites and assay method of alkaloids, flavonoids, saponins, terpenoids, stilbenes, phenols, quinones, lignans and esters. The parent drugs, perhaps the metabolites, or they together play a role in pharmacological effects. And different routes of administration may lead to different results of transformation pathways and metabolites. Moreover, high-tech assay methods, particularly the combined use of modern instrument analytical techniques, are beneficial to the research of drug metabolism.

  1. MBROLE 2.0-functional enrichment of chemical compounds.

    Science.gov (United States)

    López-Ibáñez, Javier; Pazos, Florencio; Chagoyen, Mónica

    2016-07-01

    Metabolites Biological Role (MBROLE) is a server that performs functional enrichment analysis of a list of chemical compounds derived from a metabolomics experiment, which allows this list to be interpreted in biological terms. Since its release in 2011, MBROLE has been used by different groups worldwide to analyse metabolomics experiments from a variety of organisms. Here we present the latest version of the system, MBROLE2, accessible at http://csbg.cnb.csic.es/mbrole2 MBROLE2 has been supplemented with 10 databases not available in the previous version, which allow analysis over a larger, richer set of vocabularies including metabolite-protein and drug-protein interactions. This new version performs automatic conversion of compound identifiers from different databases, thus simplifying usage. In addition, the user interface has been redesigned to generate an interactive, more intuitive representation of the results.

  2. Quantum chemical studies of photochromic properties of benzoxazine compound

    Energy Technology Data Exchange (ETDEWEB)

    Toliautas, Stepas, E-mail: stepas.toliautas@ff.stud.vu.lt [Department of Theoretical Physics, Vilnius University, Sauletekio 9-III, LT-10222 Vilnius (Lithuania); Sulskus, Juozas, E-mail: juozas.sulskus@ff.vu.lt [Department of Theoretical Physics, Vilnius University, Sauletekio 9-III, LT-10222 Vilnius (Lithuania); Valkunas, Leonas, E-mail: leonas.valkunas@ff.vu.lt [Department of Theoretical Physics, Vilnius University, Sauletekio 9-III, LT-10222 Vilnius (Lithuania); Institute of Physics, Center for Physical Sciences and Technology, Savanoriu 231, LT-02300 Vilnius (Lithuania); Vengris, Mikas, E-mail: mikas.vengris@ff.vu.lt [Department of Quantum Electronics, Vilnius University, Sauletekio 9-III, LT-10222 Vilnius (Lithuania)

    2012-08-24

    Highlights: Black-Right-Pointing-Pointer Photochromic indolo-benzoxazine compound is studied. Black-Right-Pointing-Pointer Advanced LC-TDDFT and GMC-QDPT methods are used for excited state calculations. Black-Right-Pointing-Pointer Oxazine ring opens upon UV light excitation. Black-Right-Pointing-Pointer Fragments of the compound assume structures similar to the ions of separate molecules. Black-Right-Pointing-Pointer Multiple pathways of the photo-induced reaction are expected. -- Abstract: Molecular electronic structure of ground and excited states of a photochromic indolo[2,1-b][1,3]benzoxazine compound incorporating closed-ring system, which opens upon UV light excitation, was studied using various quantum chemical methods. Three local minima of the ground electronic state potential energy surface and related transition states were identified along the path of rotation of 4-nitrophenol group. Additionally, three local minima of the excited electronic states were located. The evaluated transition energy barriers between local ground-state minima nearest to the initial structure of the investigated molecule are less than 2 k{sub B}T, making open structures likely to revert to the initial structure by thermalization. Results obtained using ab initio GMC-QDPT method were explored and compared to the widely used TD-DFT and semi-empiric ZINDO methods.

  3. [Physical, chemical and bioactive compounds of tree tomato (Cyphomandra betacea)].

    Science.gov (United States)

    Torres, Alexia

    2012-12-01

    Tree tomato (Cyphomandra betacea) is appreciated for its excellent nutritional qualities, being considered a good source of antioxidants compounds, calcium, phosphorus, potassium and iron, sugars, organic acids, pectins and flavonoids. In this study, were evaluated physical parameters (weight, size, compression strength and humidity) and chemical (degrees Brix, titratable acidity, pH, protein, dietary fiber, ash, minerals and their bioaccesibility, pectin, antioxidants compounds) of the fruit from the Aragua State, Venezuela, as a contribution to stimulate and diversify the consumption of the tree tomato. The characterization showed that the fruits were at the ripening stage for consumption (degrees Brix 10.51, pH 3.5, acidity 0.02 g/100ml and 4.32 Kgf/cm2 compression strength) gave a yield of 74% pulp. The analytical results of the ripped pulp showed a content of 30 Kcal/100 g, dietary fiber (4.10 g/100 g), and minerals such as phosphorous, calcium, magnesium, potassium and iron (331.32, 21.25, 21.18, 17.03 and 7.44 mg/100 g, respectively). Bioaccesibility values of 6.71 and 1.86% were reported for calcium and iron. The extracted pectin (1.00 g/100 g) was classified as high methoxyl with high degree of esterification. The antioxidant capacity of the ripped pulp (EC50 of 165.00 g/g DPPH and reducing power of 0.07 mmol Fe +2/100 g), could be attributed to the presence of ascorbic acid (23.32 mg/100 g), lycopene (1.22 mg/100 g), and phenolic compounds (1.39 mg GAE/g), anthocyanins (0.29 mg cyanidin/g) and tannins (0.40 mg catechin/100 g).The results obtained encourage the nutritional benefits and suggest applications as a functional ingredient in food product development.

  4. The Periodic Table as a Part of the Periodic Table of Chemical Compounds

    CERN Document Server

    Labushev, Mikhail M

    2011-01-01

    The numbers of natural chemical elements, minerals, inorganic and organic chemical compounds are determined by 1, 2, 3 and 4-combinations of a set 95 and are respectively equal to 95, 4,465, 138,415 and 3,183,545. To explain these relations it is suggested the concept of information coefficient of proportionality as mathematical generalization of the proportionality coefficient for any set of positive numbers. It is suggested a hypothesis that the unimodal distributions of the sets of information coefficients of proportionality for atomic weights of chemical elements of minerals and chemical compounds correspond to unimodal distributions of the above sets for combination of 2, 3 and 4 atomic weights of 95 natural chemical elements. The expected values of symmetrized distributions of information coefficients of proportionality sets for atomic weights of minerals and chemical compounds are proposed to be used to define chemical compounds, like atomic weights define chemical elements. Variational series of the e...

  5. Chemical and pharmacological characterization of hypolipidemic compound from Cajanus Cajan

    Directory of Open Access Journals (Sweden)

    Md. Anwar Habib

    2010-03-01

    Full Text Available The study was carried out to identify the compound responsible for hypolipidemic and hypoglycemic effects of Cajanus cajan (redgram. The methanol extract of redgram seeds were fractionated into petroleum ether, chloroform, and methanol. The methanol fraction significantly decreased fasting blood glucose, and lipid profiles (p<0.001 on streptozotocin-induced mice compared to control. The methanol fraction was then subjected to chromatographic analysis and a compound (CCA1 has been isolated. The structure of the compound is considered to be substituted cyclopentene with glucose by analysis its 1H and 13C-NMR data. Biological studies of the isolated compound possessed prominent hypolipidemic activity. Although a number of hypoglycemic compounds are reported, yet not any hypolipidemic compound from redgram. The compound CCA1 seems to be the first report on hypolipidemic activity from methanol extract of redgram.

  6. Emission and Chemical Transformation of Biogenic Volatile Organic Compounds (echo)

    Science.gov (United States)

    Koppmann, R.; Hoffmann, T.; Kesselmeier, J.; Schatzmann, M.

    Forests are complex sources of biogenic volatile organic compounds (VOC) in the planetary boundary layer. The impact of biogenic VOC on tropospheric photochem- istry, air quality, and the formation of secondary products affects our climate on a regional and global scale but is far from being understood. A considerable lack of knowledge exists concerning a forest stand as a net source of reactive trace com- pounds, which are transported directly into the planetary boundary layer (PBL). In particular, little is known about the amounts of VOC which are processed within the canopy. The goal of ECHO, which is presented in this poster, is to investigate these questions and to improve our understanding of biosphere-atmosphere interactions and their effects on the PBL. The investigation of emissions, chemical processing and vertical transport of biogenic VOC will be carried out in and above a mixed forest stand in Jülich, Germany. A large set of trace gases, free radicals and meteorologi- cal parameters will be measured at different heights in and above the canopy, covering concentrations of VOC, CO, O3, organic nitrates und NOx as well as organic aerosols. For the first time concentration profiles of OH, HO2, RO2 und NO3 radicals will be measured as well together with the actinic UV radiation field and photolysis frequen- cies of all relevant radical precursors (O3, NO2, peroxides, oxygenated VOC). The different tasks of the field experiments will be supported by simulation experiments investigating the primary emission and the uptake of VOC by the plants in stirred tank reactors, soil parameters and soil emissions in lysimeter experiments, and the chem- ical processing of the trace gases as observed in and above the forest stand in the atmosphere simulation chamber SAPHIR. The planning and interpretation of the field experiments is supported by simulations of the field site in a wind tunnel.

  7. Environmental Fate of Organophosphorus Compounds Related to Chemical Weapons

    Energy Technology Data Exchange (ETDEWEB)

    Davisson, M L; Love, A H; Vance, A; Reynolds, J G

    2005-02-08

    Man-made organophosphorus compounds have been widely distributed throughout our environment as pesticides since their development during and after WWII. Many important studies have documented their relative persistence and toxicity. Development and use of some organophosphorus compounds as nerve agents gave rise to a separate but parallel effort to understand environmental persistence. In this latter case, the experiments have focused mainly on evaporation rates and first-order reaction kinetics. However, because organophosphorus compounds are easily polarized, the ionic content of a surrounding media directly factors into these reaction rates, but limited work in this regard has been done under environmentally relevant conditions. Furthermore, limited experiments investigating persistence of these agents on soil has resulted in widely varying degradation rates. Not surprisingly, no studies have investigated affinities of organophosphorus nerve agents to mineral or organic matter typically found in soil. As a result, we initiated laboratory experiments on dilute concentrations of nerve agent O-ethyl S-(2-diisopropylaminoethyl) methylphosphonothiolate (VX) to quantify persistence in simulated environmental aqueous conditions. A quantitative analytical method was developed for VX and its degradation products using High Performance Liquid Chromatography-Electrospray Ionization-Mass Spectrometry (HPLC-ESI-MS). VX hydrolysis rate is known to have a pH-dependency, however, the type of buffer and the relative proportion of different nucleophiles in solution significantly affect the overall rate and mechanism of degradation. For example, dissolved carbonate, a weak nucleophile dominating natural water, yielded pseudo-first order rate constants of {approx} 8 x 10{sup -3}/hr at pH 5 and 2 x 10{sup -2}/hr at pH 11. This small pH-dependent variation departs significantly from widely accepted rates at this pH range (4 x 10{sup -4}/hr to 8 x 10{sup -2}/hr) that were based on

  8. Simplified fate modelling in respect to ecotoxicological and human toxicological characterisation of emissions of chemical compounds

    DEFF Research Database (Denmark)

    Birkved, Morten; Heijungs, Reinout

    2011-01-01

    The impact assessment of chemical compounds in Life Cycle Impact Assessment (LCIA) and Environmental Risk Assessment (ERA) requires a vast amount of data on the properties of the chemical compounds being assessed. The purpose of the present study is to explore statistical options for reduction of...

  9. Microscopic physical and chemical properties of graphite intercalation compounds

    Energy Technology Data Exchange (ETDEWEB)

    Eklund, P.C.

    1992-08-24

    Optical spectroscopy (Raman, FTIR and Reflection ) was used to study a variety of acceptor- and donor-type compounds synthesized to determine the microscopic models consistent with the spectrocsopic results. General finding is that the electrical conduction properties of these compounds can be understood on the basis that the intercalation of atomic and/or molecular species between the host graphite layers either raises or lowers the Fermi level (E{sub F)} in a graphitic band structure. This movement of E{sub F} is accomplished via a charge transfer of electrons from the intercalate layers to the graphitic layers (donor compounds), or vice versa (acceptor compounds). Furthermore, the band structure must be modified to take into account the layers of charge that occur as a result of the charge transfer. This charge layering introduces additional bands of states near E{sub F}, which are discussed. Charge-transfer also induces a perturbation of the graphitic normal mode frequencies which can be understood as the result of a contraction (acceptor compounds) or expansion (donor compounds) of the intralayer C-C bonds. Ab-initio calculations support this view and are in reasonable agreement with experimental data.

  10. [Assessment of the relationship of properties of chemical compounds and their toxicity to a unified hygienic standardization for chemicals].

    Science.gov (United States)

    Trushkov, V F; Perminov, K A; Sapozhnikova, V V; Ignatova, O L

    2013-01-01

    The connection of thermodynamic properties and parameters of toxicity of chemical substances was determined. Obtained data are used for the evaluation of toxicity and hygienic rate setting of chemical compounds. The relationship between enthalpy and toxicity of chemical compounds has been established. Orthogonal planning of the experiment was carried out in the course of the investigations. Equation of unified hygienic rate setting in combined, complex, conjunct influence on the organism is presented. Prospects of determination of toxicity and methodology of unified hygienic rate setting in combined, complex, conjunct influence on the organism are presented

  11. Chemical compounds and pharmacological effects of Rabdosia excisa

    Institute of Scientific and Technical Information of China (English)

    PANG Jinsong; YU Qian; LIU Bao

    2007-01-01

    Many kinds of diterpenoids have been isolated from Rabdosia spp.Some of them have anti-microbial effects,counteract inflammation,and inhibit tumor progression activities.We conducted the present study in order to look for bioactive compounds in the medicinal plant Rabdosia excisa.In this study,five compounds were isolated from R.excisa;they were oridonin,isokamebakaurin,oleanolie acid,ursolic acid,and β-sitosterol.In order to identify the function of the extracts,the activity of antibiotics,antioxidation,and immunity test were carried out against these functions.Prospective results were observed in all of the tested items.

  12. STUDIES ON THE SENSITIZATION OF ANIMALS WITH SIMPLE CHEMICAL COMPOUNDS

    Science.gov (United States)

    Landsteiner, K.; Di Somma, A. A.

    1940-01-01

    Sensitization of guinea pigs to picric acid was obtained by application of oil solutions to the skin, preferably on inflamed sites or by treatment with a compound of picric acid with n-butyl-p-aminobenzoate. The lesions obtained in sensitive animals on superficial administration bore resemblance to human eczema. It seems probable that picric acid sensitization is an instance where a substance does not sensitize directly but after conversion into a more reactive compound, a principle which should be of wider application to instances where the original substance does not readily form conjugates. PMID:19871030

  13. Chemical studies on the nonlinear optics of coordina- tion compounds

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The exploration of molecule-based nonlinear optical (NLO) materials at the molecular level is one of the novel areas developed recently from the viewpoint of chemistry. This review summarizes some of our recent researches on new NLO materials based on coordination compounds, which may have potential applications in optical devices.

  14. Chemical evolution and the preservation of organic compounds on Mars

    Science.gov (United States)

    Kanavarioti, Anastassia; Mancinelli, Rocco L.

    1989-01-01

    Several lines of evidence suggest that the environment on early Mars and early Earth were very similar. Since life is abundant on Earth, it seems likely that conditions on early Earth were conducive to chemical evolution and the origin of life. The similarity between early Mars and early Earth encourages the hypothesis that chemical evolution might have also occurred on Mars, but that decreasing temperatures and the loss of its atmosphere brought the evolution to a halt. The possibility of finding on Mars remnants of organic material dating back to this early clement period is addressed.

  15. PREDICTION OF CHEMICAL REACTIVITY PARAMETERS AND PHYSICAL PROPERTIES OF ORGANIC COMPOUNDS FROM MOLECULAR STRUCTURE USING SPARC

    Science.gov (United States)

    The computer program SPARC (SPARC Performs Automated Reasoning in Chemistry) has been under development for several years to estimate physical properties and chemical reactivity parameters of organic compounds strictly from molecular structure. SPARC uses computational algorithms...

  16. Predicting partitioning of volatile organic compounds from air into plant cuticular matrix by quantum chemical descriptors

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Based on theoretical linear solvation energy relationship and quantum chemical descriptors computed by AM1 Hamiltonian, a new model is developed to predict the partitioning of some volatile organic compounds between the plant cuticular matrix and air.

  17. Cyanobacterium sp. host cell and vector for production of chemical compounds in Cyanobacterial cultures

    Energy Technology Data Exchange (ETDEWEB)

    Piven, Irina; Friedrich, Alexandra; Duhring, Ulf; Uliczka, Frank; Baier, Kerstin; Inaba, Masami; Shi, Tuo; Wang, Kui; Enke, Heike; Kramer, Dan

    2016-04-19

    A cyanobacterial host cell, Cyanobacterium sp., that harbors at least one recombinant gene for the production of a chemical compounds is provided, as well as vectors derived from an endogenous plasmid isolated from the cell.

  18. Cyanobacterium sp. host cell and vector for production of chemical compounds in cyanobacterial cultures

    Science.gov (United States)

    Piven, Irina; Friedrich, Alexandra; Duhring, Ulf; Uliczka, Frank; Baier, Kerstin; Inaba, Masami; Shi, Tuo; Wang, Kui; Enke, Heike; Kramer, Dan

    2014-09-30

    A cyanobacterial host cell, Cyanobacterium sp., that harbors at least one recombinant gene for the production of a chemical compounds is provided, as well as vectors derived from an endogenous plasmid isolated from the cell.

  19. Grape Seed Oil Compounds: Biological and Chemical Actions for Health

    Science.gov (United States)

    Garavaglia, Juliano; Markoski, Melissa M.; Oliveira, Aline; Marcadenti, Aline

    2016-01-01

    Grape seed oil is rich in phenolic compounds, fatty acids, and vitamins, with economic importance to pharmaceutical, cosmetic, and food industry. Its use as an edible oil has also been suggested, especially due to its pleasant sensory characteristics. Grape seed oil has beneficial properties for health that are mainly detected by in vitro studies, such as anti-inflammatory, cardioprotective, antimicrobial, and anticancer properties, and may interact with cellular and molecular pathways. These effects have been related to grape seed oil constituents, mainly tocopherol, linolenic acid, resveratrol, quercetin, procyanidins, carotenoids, and phytosterols. The aim of this article was to briefly review the composition and nutritional aspects of grape seed oil, the interactions of its compounds with molecular and cellular pathways, and its possible beneficial effects on health. PMID:27559299

  20. Radiation induced chemical changes of phenolic compounds in strawberries

    Energy Technology Data Exchange (ETDEWEB)

    Breitfellner, F.; Solar, S. E-mail: sonja.solar@univie.ac.at; Sontag, G

    2003-06-01

    In unirradiated strawberries four phenolic acids (gallic acid, p-coumaric acid, caffeic acid and 4-hydroxybenzoic acid), the flavonoids (+)-catechin, (-)-epicatechin and glycosides from kaempferol and quercetin were determined by reversed phase chromatography with diode array detection. Characteristic linear dose/concentration relationships were found for 4-hydroxybenzoic acid and two unidentified compounds. One of them may be usable as marker to prove an irradiation treatment.

  1. Portable Sensor for Chemical Nerve Agents and Organophosphorus Compounds

    Science.gov (United States)

    2015-08-18

    III) and Fe(II) Kristopher Brown Abstract Some of the major objectives of analytical chemistry research include the search for quick ...Crystalline Colloidal Array Thin Film Modified ?-Cyclodextrin for the Detection of Organophosphate Compounds, Analytical and Bioanalytical Chemistry (07...Discipline Kristopher Brown 0.30 Chemistry Charlene N. Middlebrooks 0.30 Chemistry Juan Onto 0.20 Chemistry KaBreshiya Austin 0.30 Forensic Science

  2. Inhibition of the compound action potentials of frog sciatic nerves by aroma oil compounds having various chemical structures.

    Science.gov (United States)

    Ohtsubo, Sena; Fujita, Tsugumi; Matsushita, Akitomo; Kumamoto, Eiichi

    2015-03-01

    Plant-derived chemicals including aroma oil compounds have an ability to inhibit nerve conduction and modulate transient receptor potential (TRP) channels. Although applying aroma oils to the skin produces a local anesthetic effect, this has not been yet examined throughly. The aim of the present study was to know how nerve conduction inhibitions by aroma oil compounds are related to their chemical structures and whether these activities are mediated by TRP activation. Compound action potentials (CAPs) were recorded from the frog sciatic nerve by using the air-gap method. Citral (aldehyde), which activates various types of TRP channels, attenuated the peak amplitude of CAP with the half-maximal inhibitory concentration (IC50) value of 0.46 mmol/L. Another aldehyde (citronellal), alcohol (citronellol, geraniol, (±)-linalool, (-)-linalool, (+)-borneol, (-)-borneol, α-terpineol), ester (geranyl acetate, linalyl acetate, bornyl acetate), and oxide (rose oxide) compounds also reduced CAP peak amplitudes (IC50: 0.50, 0.35, 0.53, 1.7, 2.0, 1.5, 2.3, 2.7, 0.51, 0.71, 0.44, and 2.6 mmol/L, respectively). On the other hand, the amplitudes were reduced by a small extent by hydrocarbons (myrcene and p-cymene) and ketone (camphor) at high concentrations (2-5 mmol/L). The activities of citral and other TRP agonists ((+)-borneol and camphor) were resistant to TRP antagonist ruthenium red. An efficacy sequence for the CAP inhibitions was generally aldehydes ≥ esters ≥ alcohols > oxides > hydrocarbons. The CAP inhibition by the aroma oil compound was not related to its octanol-water partition coefficient. It is suggested that aroma oil compounds inhibit nerve conduction in a manner specific to their chemical structures without TRP activation.

  3. Extraction and Characterization of Chemical Compounds in Coelaenomenodera elaeidis (Coleoptera: Chrysomelidae)

    Science.gov (United States)

    To elucidate the characterization of probable pheromone chemical compounds in Coelaenomenodera elaeidis Mlk., volatile samples were collected and subjected to gas chromatographic-mass spectrometric analyses. These compounds were contained in active fractions: Butylated hydroxytoluene (C15H24O); 4, 4...

  4. Detection of Chlorophenolic Compounds in Bleaching Effluents of Chemical Pulps

    Institute of Scientific and Technical Information of China (English)

    Chhaya Sharma; S.Mohanty; S.Kumar; N.J.Rao; li qian

    2008-01-01

    Laboratory bleaching effluents from the chlorination and caustic extraction stages of mixed wood kraft pulp processing have been analysed both qualitatively and quantitatively for various chlorophenolics by using GC.A number of chlorinated derivaties of phenols,catechols,guaiacols and syringaldehydes have been detected and their concentrations are estimated.The results are compared with that of different agriculture residue / hardwood pulps,which were reported in literature.The concentrations of various compounds detected have also been compared with their reported 96LC50 values.

  5. Chemical Characterization of Compounds Released by Marine Mammals.

    Science.gov (United States)

    1983-08-01

    W:.. CHEMICAL ANALYSIS . MATERIALS AND MODS One sample of urine and four of semen ( sperm and/or seminal fluid) were obtained from a male Atlantic...Analysis: Seminal Plasma and Prostatic Fluid Compositions and their Interrelations with Sperm Quality, Int J Fertil, vol 22(3), p 140-147, 1977 4o 43...Ahluwalia, B and Holman, RT, Fatty Acid Composition of Lipids of Bull, Boar , Rabbit and Human Semen, J Reprod Fert, vol 18, p 431-437, 1969 64. Glenn

  6. Machine Learning of Molecular Electronic Properties in Chemical Compound Space

    CERN Document Server

    Montavon, Grégoire; Gobre, Vivekanand; Vazquez-Mayagoitia, Alvaro; Hansen, Katja; Tkatchenko, Alexandre; Müller, Klaus-Robert; von Lilienfeld, O Anatole

    2013-01-01

    The combination of modern scientific computing with electronic structure theory can lead to an unprecedented amount of data amenable to intelligent data analysis for the identification of meaningful, novel, and predictive structure-property relationships. Such relationships enable high-throughput screening for relevant properties in an exponentially growing pool of virtual compounds that are synthetically accessible. Here, we present a machine learning (ML) model, trained on a data base of \\textit{ab initio} calculation results for thousands of organic molecules, that simultaneously predicts multiple electronic ground- and excited-state properties. The properties include atomization energy, polarizability, frontier orbital eigenvalues, ionization potential, electron affinity, and excitation energies. The ML model is based on a deep multi-task artificial neural network, exploiting underlying correlations between various molecular properties. The input is identical to \\emph{ab initio} methods, \\emph{i.e.} nucle...

  7. Phenolic derivatives and other chemical compounds from Cochlospermum regium

    Directory of Open Access Journals (Sweden)

    Soraya Solon

    2012-01-01

    Full Text Available This study describes the chemical investigation of the ethyl acetate fraction obtained from the hydroethanolic extract of the xylopodium of Cochlospermum regium (Mart. & Schr. Pilger, which has been associated with antimicrobial activity. Phytochemical investigation produced seven phenol derivatives: ellagic acid, gallic acid, dihydrokaempferol, dihydrokaempferol-3-O-β-glucopyranoside, dihydrokaempferol-3-O-β-(6"-galloyl-glucopyranoside, pinoresinol, and excelsin. It also contained two triacylbenzenes, known as cochlospermines A and B. The hydroethanolic extract and its fractions exhibited antimicrobial activity (0.1 mg/mL against Staphylococcus aureus and Pseudomonas aeruginosa. Gallic acid showed activity against S. aureus. Dihydrokaempferol-3-O-β-(6"-galloyl-glucopyranoside is reported here for the first time in the literature.

  8. Crystal chemical characterization of mullite-type aluminum borate compounds

    Science.gov (United States)

    Hoffmann, K.; Hooper, T. J. N.; Zhao, H.; Kolb, U.; Murshed, M. M.; Fischer, M.; Lührs, H.; Nénert, G.; Kudějová, P.; Senyshyn, A.; Schneider, H.; Hanna, J. V.; Gesing, Th. M.; Fischer, R. X.

    2017-03-01

    Al-rich aluminum borates were prepared by different synthesis routes using various Al/B ratios, characterized by diffraction methods, spectroscopy and prompt gamma activation analysis. The 11B NMR data show a small amount of BO4 species in all samples. The chemical analysis indicates a trend in the Al/B ratio instead of a fixed composition. Both methods indicate a solid solution Al5-xB1+xO9 where Al is substituted by B in the range of 1-3%. The structure of B-rich Al4B2O9 (C2/m, a=1488 pm, b=553 pm, c=1502 pm, ß=90.6°), was re-investigated by electron diffraction methods, showing that structural details vary within a crystallite. In most of the domains the atoms are orderly distributed, showing no signal for the postulated channel oxygen atom O5. The absence of O5 is supported by density functional theory calculations. Other domains show a probable disordered configuration of O5 and O10, indicated by diffuse scattering along the b direction.

  9. Systematic mining of generally recognized as safe (GRAS) flavor chemicals for bioactive compounds.

    Science.gov (United States)

    Martinez-Mayorga, Karina; Peppard, Terry L; López-Vallejo, Fabian; Yongye, Austin B; Medina-Franco, José L

    2013-08-07

    Bioactive food compounds can be both therapeutically and nutritionally relevant. Screening strategies are widely employed to identify bioactive compounds from edible plants. Flavor additives contained in the so-called FEMA GRAS (generally recognized as safe) list of approved flavoring ingredients is an additional source of potentially bioactive compounds. This work used the principles of molecular similarity to identify compounds with potential mood-modulating properties. The ability of certain GRAS molecules to inhibit histone deacetylase-1 (HDAC1), proposed as an important player in mood modulation, was assayed. Two GRAS chemicals were identified as HDAC1 inhibitors in the micromolar range, results similar to what was observed for the structurally related mood prescription drug valproic acid. Additional studies on bioavailability, toxicity at higher concentrations, and off-target effects are warranted. The methodology described in this work could be employed to identify potentially bioactive flavor chemicals present in the FEMA GRAS list.

  10. Chemical characterization and evaluation of biological activity of Cynara cardunculus extractable compounds

    OpenAIRE

    Ramos, Patrícia Alexandra Bogango

    2015-01-01

    The Mediterranean species Cynara cardunculus L. is recognized in the traditional medicine, for their hepatoprotective and choleretic effects. Biomass of C. cardunculus L. var. altilis (DC), or cultivated cardoon, may be explored not only for the production of energy and pulp fibers, but also for the extraction of bioactive compounds. The chemical characterization of extractable components, namely terpenic and phenolic compounds, may valorize the cultivated cardoon plantation, due to their ant...

  11. Chemical-genetic profile analysis of five inhibitory compounds in yeast

    Directory of Open Access Journals (Sweden)

    Alamgir Md

    2010-08-01

    Full Text Available Abstract Background Chemical-genetic profiling of inhibitory compounds can lead to identification of their modes of action. These profiles can help elucidate the complex interactions between small bioactive compounds and the cell machinery, and explain putative gene function(s. Results Colony size reduction was used to investigate the chemical-genetic profile of cycloheximide, 3-amino-1,2,4-triazole, paromomycin, streptomycin and neomycin in the yeast Saccharomyces cerevisiae. These compounds target the process of protein biosynthesis. More than 70,000 strains were analyzed from the array of gene deletion mutant yeast strains. As expected, the overall profiles of the tested compounds were similar, with deletions for genes involved in protein biosynthesis being the major category followed by metabolism. This implies that novel genes involved in protein biosynthesis could be identified from these profiles. Further investigations were carried out to assess the activity of three profiled genes in the process of protein biosynthesis using relative fitness of double mutants and other genetic assays. Conclusion Chemical-genetic profiles provide insight into the molecular mechanism(s of the examined compounds by elucidating their potential primary and secondary cellular target sites. Our follow-up investigations into the activity of three profiled genes in the process of protein biosynthesis provided further evidence concerning the usefulness of chemical-genetic analyses for annotating gene functions. We termed these genes TAE2, TAE3 and TAE4 for translation associated elements 2-4.

  12. Targeting apoptosis pathways by natural compounds in cancer: marine compounds as lead structures and chemical tools for cancer therapy.

    Science.gov (United States)

    von Schwarzenberg, Karin; Vollmar, Angelika M

    2013-05-28

    Natural compounds derived from marine organisms have shown a wide variety of anti-tumor effects and a lot of attention has been drawn to further development of the isolated compounds. A vast quantity of individual chemical structures from different organisms has shown a variety of apoptosis inducing mechanisms in a variety of tumor cells. The bis-steroidal cephalostatin 1 for example, induces apoptosis via activation of caspases whereas the polyketide discodermolide inhibits cell growth by binding to and stabilizing microtubule and salisporamide A, the product of an actinobacterial strain, is an inhibitor of the proteasome. This great variety of mechanisms of action can help to overcome the multitude of resistances exhibited by different tumor specimens. Products from marine organisms and their synthetic derivates are therefore an important source for new therapeutics for single agent or combined therapy with other chemotherapeutics to support the struggle against cancer.

  13. Chemical effect on the K shell fluorescence yield of Fe, Mn, Co, Cr and Cu compounds

    Indian Academy of Sciences (India)

    U Turgut

    2004-11-01

    Chemical effects on the K shell fluorescence yields of Fe, Mn, Co, Cr and Cu compounds were investigated. Samples were excited using 59.5 keV energy photons from a 241Am radioisotope source. K X-rays emitted by samples were counted by a Si(Li) detector with a resolution 160 eV at 5.9 keV. Chemical effects on the K shell fluorescence yields (K) for Fe, Mn, Co, Cr and Cu compounds were observed. The values are compared with theoretical, semiempirical fit and experimental ones for the pure elements.

  14. Monitoring the Evolution of Major Chemical Compound in Dairy Products During Shelf-Life by FTIR

    Directory of Open Access Journals (Sweden)

    Adriana Păucean

    2014-11-01

    Full Text Available Fourier-transform infrared (FTIR spectroscopy is considered to be a comprehensive and sensitive method to characterize the chemical composition and for detection of molecular changes in different samples. In this study, FTIRspectroscopy  was employed as an rapid and low-cost technique in order to characterize the FTIR spectra and identify appropriate spectral regions for dairy product fermented by a lactic culture consisting by species of Lactococcus lactis and Leuconostoc mesenteroides. A second objective was to monitore the key chemical compounds (lactose, lactic acid, flavors during fermentation and refrigerated storage (1-21 days, at 4-6°C. By FT-IR fingerprint during fermentation we identified changes of the spectra pattern with specific increasing or decreasing peaks for lactose, lactic acid, esters, aromatic compounds, aminoacids, fatty acids. Also the technique was able to identify chemical compounds involved in the microbial activity such as phosphates and phosphorylated carbohydrates during fermentation and dairy product shelf-life. All the major chemical compounds recorded significant increaments during fermentation and refrigerated storage comparing with the raw milk.

  15. A method to estimate the enthalpy of formation of organic compounds with chemical accuracy

    DEFF Research Database (Denmark)

    Hukkerikar, Amol; Meier, Robert J.; Sin, Gürkan

    2013-01-01

    . The model which is group-contribution (GC) based, estimates gas phase standard enthalpy of formations (ΔfH°gas) of organic compounds. To achieve the chemical accuracy, a systematic property-data-model analysis, which allows efficient use of knowledge of the experimental data of ΔfH°gas and the molecular...

  16. Antibacterial activity of coffee extracts and selected coffee chemical compounds against enterobacteria.

    Science.gov (United States)

    Almeida, Ana Amélia P; Farah, Adriana; Silva, Daniela A M; Nunan, Elzíria A; Glória, M Beatriz A

    2006-11-15

    The in vitro antimicrobial activity of commercial coffee extracts and chemical compounds was investigated on nine strains of enterobacteria. The antimicrobial activity investigated by the disc diffusion method was observed in both the extracts and tested chemical compounds. Even though pH, color, and the contents of trigonelline, caffeine, and chlorogenic acids differed significantly among the coffee extracts, no significant differences were observed in their antimicrobial activity. Caffeic acid and trigonelline showed similar inhibitory effect against the growth of the microorganisms. Caffeine, chlorogenic acid, and protocatechuic acid showed particularly strong effect against Serratia marcescens and Enterobacter cloacae. The IC(50) and IC(90) for the compounds determined by the microtiter plate method indicated that trigonelline, caffeine, and protocatechuic acids are potential natural antimicrobial agents against Salmonella enterica. The concentrations of caffeine found in coffee extracts are enough to warrant 50% of the antimicrobial effect against S. enterica, which is relevant to human safety.

  17. Chemical Compounds Toxic to Invertebrates Isolated from Marine Cyanobacteria of Potential Relevance to the Agricultural Industry

    Directory of Open Access Journals (Sweden)

    Magbubah Essack

    2014-10-01

    Full Text Available In spite of advances in invertebrate pest management, the agricultural industry is suffering from impeded pest control exacerbated by global climate changes that have altered rain patterns to favour opportunistic breeding. Thus, novel naturally derived chemical compounds toxic to both terrestrial and aquatic invertebrates are of interest, as potential pesticides. In this regard, marine cyanobacterium-derived metabolites that are toxic to both terrestrial and aquatic invertebrates continue to be a promising, but neglected, source of potential pesticides. A PubMed query combined with hand-curation of the information from retrieved articles allowed for the identification of 36 cyanobacteria-derived chemical compounds experimentally confirmed as being toxic to invertebrates. These compounds are discussed in this review.

  18. Phenolic Melatonin-Related Compounds: Their Role as Chemical Protectors against Oxidative Stress

    Directory of Open Access Journals (Sweden)

    Annia Galano

    2016-10-01

    Full Text Available There is currently no doubt about the serious threat that oxidative stress (OS poses to human health. Therefore, a crucial strategy to maintain a good health status is to identify molecules capable of offering protection against OS through chemical routes. Based on the known efficiency of the phenolic and melatonin (MLT families of compounds as antioxidants, it is logical to assume that phenolic MLT-related compounds should be (at least equally efficient. Unfortunately, they have been less investigated than phenols, MLT and its non-phenolic metabolites in this context. The evidence reviewed here strongly suggests that MLT phenolic derivatives can act as both primary and secondary antioxidants, exerting their protection through diverse chemical routes. They all seem to be better free radical scavengers than MLT and Trolox, while some of them also surpass ascorbic acid and resveratrol. However, there are still many aspects that deserve further investigations for this kind of compounds.

  19. Chemical Compounds Toxic to Invertebrates Isolated from Marine Cyanobacteria of Potential Relevance to the Agricultural Industry

    KAUST Repository

    Essack, Magbubah

    2014-10-29

    In spite of advances in invertebrate pest management, the agricultural industry is suffering from impeded pest control exacerbated by global climate changes that have altered rain patterns to favour opportunistic breeding. Thus, novel naturally derived chemical compounds toxic to both terrestrial and aquatic invertebrates are of interest, as potential pesticides. In this regard, marine cyanobacterium-derived metabolites that are toxic to both terrestrial and aquatic invertebrates continue to be a promising, but neglected, source of potential pesticides. A PubMed query combined with hand-curation of the information from retrieved articles allowed for the identification of 36 cyanobacteria-derived chemical compounds experimentally confirmed as being toxic to invertebrates. These compounds are discussed in this review.

  20. Improving solubility and chemical stability of natural compounds for medicinal use by incorporation into liposomes.

    Science.gov (United States)

    Coimbra, Maria; Isacchi, Benedetta; van Bloois, Louis; Torano, Javier Sastre; Ket, Aldo; Wu, Xiaojie; Broere, Femke; Metselaar, Josbert M; Rijcken, Cristianne J F; Storm, Gert; Bilia, Rita; Schiffelers, Raymond M

    2011-09-20

    Natural bioactive compounds have been studied for a long time for their chemopreventive and therapeutic potential in several chronic inflammatory diseases, including cancer. However, their physicochemical properties generally result in poor chemical stability and lack of in vivo bioavailability. Very few human clinical trials have addressed absorption, distribution, metabolism, and excretion of these compounds in relation to efficacy. This limits the use of these valuable natural compounds in the clinic. In this study, we examined caffeic acid (derivatives), carvacrol (derivatives), thymol, pterostilbene (derivatives), and N-(3-oxo-dodecanoyl)-l-homoserine lactone. These are natural compounds with strong anti-inflammatory properties derived from plants and bacteria. However, these compounds have poor water solubility or are chemically unstable. To overcome these limitations we have prepared liposomal formulations. Our results show that lipophilic 3-oxo-C(12)-homoserine lactone and stilbene derivatives can be loaded into liposomal lipid bilayer with efficiencies of 50-70%. Thereby, the liposomes solubilize these compounds, allowing intravenous administration without use of solvents. When compounds could not be loaded into the lipid bilayer (carvacrol and thymol) or are rapidly extracted from the liposomes in the presence of serum albumin (3-oxo-C(12)-homoserine lactone and pterostilbene derivatives), derivatization of the compound into a water-soluble prodrug was shown to improve loading efficiency and encapsulation stability. The phosphate forms of carvacrol and pterostilbene were loaded into the aqueous interior of the liposomes and encapsulation was unaffected by the presence of serum albumin. Chemical instability of resveratrol was improved by liposome-encapsulation, preventing inactivating cis-trans isomerization. For caffeic acid, liposomal encapsulation did not prevent oxidation into a variety of products. Still, by derivatization into a phenyl ester, the

  1. Chemometric studies of chemical compounds in five cultivars of potatoes from Tenerife.

    Science.gov (United States)

    Casañas, Ricardo; González, Mónica; Rodríguez, Elena; Marrero, Antonio; Díaz, Carlos

    2002-03-27

    A statistical study of correlation and multivariate analysis on the chemical composition of five cultivars of potatoes harvested in Tenerife was carried out to establish the relationships between the chemical compounds and, therefore, to differentiate the samples according to traditional and recent importation potatoes, cultivars, and species/subspecies. A large number of significant correlations between the chemical compounds were found, which suggests biochemical relationships among them. After factor analysis, the dimension space was reduced from 24 variables to eight factors, accounting for 77.2% of the total variance. Starch, moisture, organic acids, and metals are the variables that make it possible to characterize the system without losing very much information. Total differentiation of potato samples according to the criteria species/subspecies and cultivars was obtained using discriminant analysis with all the variables. However, with only four variables (weight of tuber, starch, amylose, and glucose + fructose) it is possible to differentiate between the traditional and recent importation potatoes.

  2. Biological and chemical investigation of Allium cepa L. response to selenium inorganic compounds.

    Science.gov (United States)

    Michalska-Kacymirow, M; Kurek, E; Smolis, A; Wierzbicka, M; Bulska, E

    2014-06-01

    The aim of this study was to evaluate the biological and chemical response of Allium cepa L. exposed to inorganic selenium compounds. Besides the investigation of the total content of selenium as well as its chemical speciation, the Allium test was used to evaluate the growth of onion roots and mitotic activity in the roots' meristem. The total content of selenium was determined by inductively coupled plasma mass spectrometry (ICP MS). High-performance liquid chromatography (HPLC), coupled to ICP MS, was used for the selenium chemical speciation. Results indicated that A. cepa plants are able to biotransform inorganic selenium compounds into their organic derivatives, e.g., Se-methylselenocysteine from the Se(IV) inorganic precursor. Although the differences in the biotransformation of selenium are due mainly to the oxidation state of selenium, the experiment has also shown a fine effect of counter ions (H(+), Na(+), NH4 (+)) on the response of plants and on the specific metabolism of selenium.

  3. Passive Sampling in Regulatory Chemical Monitoring of Nonpolar Organic Compounds in the Aquatic Environment

    DEFF Research Database (Denmark)

    Booij, Kees; Robinson, Craig D; Burgess, Robert M;

    2016-01-01

    We reviewed compliance monitoring requirements in the European Union, the United States, and the Oslo-Paris Convention for the protection of the marine environment of the North-East Atlantic, and evaluated if these are met by passive sampling methods for nonpolar compounds. The strengths and shor...... is the best available technology for chemical monitoring of nonpolar organic compounds. Key issues to be addressed by scientists and environmental managers are outlined.......We reviewed compliance monitoring requirements in the European Union, the United States, and the Oslo-Paris Convention for the protection of the marine environment of the North-East Atlantic, and evaluated if these are met by passive sampling methods for nonpolar compounds. The strengths...... and shortcomings of passive sampling are assessed for water, sediments, and biota. Passive water sampling is a suitable technique for measuring concentrations of freely dissolved compounds. This method yields results that are incompatible with the EU's quality standard definition in terms of total concentrations...

  4. A Chemical Screen Identifies Novel Compounds That Overcome Glial-Mediated Inhibition Of Neuronal Regeneration

    Science.gov (United States)

    Usher, Lynn C.; Johnstone, Andrea; Ertürk, Ali; Hu, Ying; Strikis, Dinara; Wanner, Ina B.; Moorman, Sanne; Lee, Jae-Wook; Min, Jaeki; Ha, Hyung-Ho; Duan, Yuanli; Hoffman, Stanley; Goldberg, Jeffrey L.; Bradke, Frank; Chang, Young-Tae; Lemmon, Vance P.; Bixby, John L.

    2010-01-01

    A major barrier to regeneration of central nervous system (CNS) axons is the presence of growth-inhibitory proteins associated with myelin and the glial scar. To identify chemical compounds with the ability to overcome the inhibition of regeneration, we screened a novel triazine library, based on the ability of compounds to increase neurite outgrowth from cerebellar neurons on inhibitory myelin substrates. The screen produced 4 “hit compounds”, which act with nM potency on several different neuronal types, and on several distinct substrates relevant to glial inhibition. Moreover, the compounds selectively overcome inhibition rather than promote growth in general. The compounds do not affect neuronal cAMP levels, PKC activity, or EGFR activation. Interestingly, one of the compounds alters microtubule dynamics and increases microtubule density in both fibroblasts and neurons. This same compound promotes regeneration of dorsal column axons after acute lesions, and potentiates regeneration of optic nerve axons after nerve crush in vivo. These compounds should provide insight into the mechanisms through which glial-derived inhibitors of regeneration act, and could lead to the development of novel therapies for CNS injury. PMID:20357120

  5. Experiment on the thermal conductivity and permeability of physical and chemical compound adsorbents for sorption process

    Science.gov (United States)

    Jin, Z. Q.; Wang, L. W.; Jiang, L.; Wang, R. Z.

    2013-08-01

    For the adsorbents in the application of refrigeration, the density of the material inside the adsorber changes because the adsorption/desorption of the refrigerant inside the adsorbents. Consequently the thermal conductivity and permeability of the adsorbents also change. In order to investigate the heat and mass transfer performance of consolidated compound adsorbent under the different equilibrium state of adsorption/desorption, the thermal conductivity and permeability test system is set up using the guarded hot plate measuring method and the principle of Ergun equation. Then various mass ratios between adsorbent and matrix of consolidated physical and chemical compound adsorbents are developed and tested under different ammonia adsorption quantity. Result shows that the thermal conductivity and permeability have strong dependence with the ratios and consolidated density of the compound adsorbent. Meanwhile, the thermal conductivity and permeability of the chemical compound adsorbents vary significantly with different adsorption quantity of ammonia, and the values for the physical compound adsorbents almost maintain a constant value with different values of adsorption quantity.

  6. Solving practical problems in environmental sampling for chemical agents and their degradation compounds

    Energy Technology Data Exchange (ETDEWEB)

    Williams, K.E.; Sheely, M.V. [Army Center for Health Promotion and Preventive Medicine, Aberdeen Proving Ground, MD (United States)

    1995-06-01

    The analyses of environmental samples for chemical agent degradation products were conducted using analytical test methods designed for evaluation of solid waste samples. All methods are found in the 3rd Edition of EPA`s compendium of analytical methods (SW-846) dated July 1992. These EPA methods are recommended for compliance testing required by the Resource Conservation and Recovery Act (RCRA) and are routinely used for the analysis of environmental samples. In the past several years, these same methods were used to support the survey of areas suspected of having chemical agent or chemical agent degradation compound contamination. An overview is presented of the U.S. Army Center for Health Promotion and Preventive Medicine`s (previously the U.S. Army Environmental Hygiene Agency) involvement with the analysis of samples for chemical agents and their degradation compounds collected from sites such as Tooele Army Depot, Rocky Mt. Arsenal, Newport Army Depot, Johnston Island, and Spring Valley, (a residential site near American University in Washington D.C.) Discussed are practical problems encountered during a quick response of a non-surety laboratory to analyze environmental samples for agents and their degradation compounds.

  7. Chemical characterisation of bioactive compounds in Medicago sativa growing in the desert of Oman.

    Science.gov (United States)

    Hanif, Muhammad Asif; Al-Maskari, Ahmed Yahya; Al-Sabahi, Jamal Nasser; Al-Hdhrami, Ibtisam; Khan, Muhammad Mumtaz; Al-Azkawi, Ahlam; Hussain, Abdullah Ijaz

    2015-01-01

    Medicago sativa Linn growing in Omani desert were chemically characterised using flame photometry, inductively coupled plasma, gas chromatography-mass spectrometry and high performance liquid chromatographic (HPLC) analysis. HPLC analyses were performed to determine the phenolics and flavonoids present in M. sativa. The major compounds detected in M. sativa leaves were protchaechenic acid (3.22%), hydroxyl benzoic acid (1.05%), β-Phenyl caffate (0.97%) and kaempherol (0.89%). Pterostilbene, a cholesterol-lowering compound, was detected in M. sativa.

  8. Molecular design chemical structure generation from the properties of pure organic compounds

    CERN Document Server

    Horvath, AL

    1992-01-01

    This book is a systematic presentation of the methods that have been developed for the interpretation of molecular modeling to the design of new chemicals. The main feature of the compilation is the co-ordination of the various scientific disciplines required for the generation of new compounds. The five chapters deal with such areas as structure and properties of organic compounds, relationships between structure and properties, and models for structure generation. The subject is covered in sufficient depth to provide readers with the necessary background to understand the modeling

  9. Extended Functional Groups (EFG: An Efficient Set for Chemical Characterization and Structure-Activity Relationship Studies of Chemical Compounds

    Directory of Open Access Journals (Sweden)

    Elena S. Salmina

    2015-12-01

    Full Text Available The article describes a classification system termed “extended functional groups” (EFG, which are an extension of a set previously used by the CheckMol software, that covers in addition heterocyclic compound classes and periodic table groups. The functional groups are defined as SMARTS patterns and are available as part of the ToxAlerts tool (http://ochem.eu/alerts of the On-line CHEmical database and Modeling (OCHEM environment platform. The article describes the motivation and the main ideas behind this extension and demonstrates that EFG can be efficiently used to develop and interpret structure-activity relationship models.

  10. Micro- and Nanostructured Metal Oxide Chemical Sensors for Volatile Organic Compounds

    Science.gov (United States)

    Alim, M. A.; Penn, B. G.; Currie, J. R., Jr.; Batra, A. K.; Aggarwal, M. D.

    2008-01-01

    Aeronautic and space applications warrant the development of chemical sensors which operate in a variety of environments. This technical memorandum incorporates various kinds of chemical sensors and ways to improve their performance. The results of exploratory investigation of the binary composite polycrystalline thick-films such as SnO2-WO3, SnO2-In2O3, SnO2-ZnO for the detection of volatile organic compound (isopropanol) are reported. A short review of the present status of the new types of nanostructured sensors such as nanobelts, nanorods, nanotube, etc. based on metal oxides is presented.

  11. Neural Network Analysis of Chemical Compounds in Nonrebreathing Fisher-344 Rat Breath

    Science.gov (United States)

    1995-12-01

    Midterm Exam for EENG 617, Math Modeling of the Central Nervous System, February 1995. 5. Frankel, Donald S., et al. "Use of a Neural Net Computer... Central Nervous System." School of Engineering, Air Force Institute of Technology, Wright-Patterson AFB OH, Winter Quarter 1995. 19. Ruck, Dennis W., et al...Octanone/ Benzofuran 2octbenz 2-Pentanone 2pent n-Pentanal npent o-Dichlorobenzene odi p-Chlorotoluene pchloro Table 22. Chemical Compound Key 53 Appendix E

  12. Application of Quantum Chemical Approximations to Environmental Problems: Prediction of Water Solubility for Nitro Compounds

    Science.gov (United States)

    2009-11-10

    Chemical Society VOL. , NO. xx, XXXX / ENVIRONMENTAL SCIENCE & TECHNOLOGY 9 A Report Documentation Page Form ApprovedOMB No. 0704-0188 Public...Gfus > 0 (2) B 9 ENVIRONMENTAL SCIENCE & TECHNOLOGY / VOL. , NO. xx, XXXX are much faster, than BVP86/TZVP calculations including COSMO/BVP86/TZVP...CL-20 (26), all other compounds (53). c Mean absolute error. VOL. , NO. xx, XXXX / ENVIRONMENTAL SCIENCE & TECHNOLOGY 9 C modified the QSPR

  13. Analysis of the relationship between the structure and aromatic properties of chemical compounds.

    Science.gov (United States)

    Debska, Barbara; Guzowska-Swider, Barbara

    2003-04-01

    This paper presents the results of research on the relationship between the structure and odour properties of a selection of chemical compounds. The research concerns five groups of esters, each with a different smell: almond, apricot, apple, pineapple and rose. The supposed relationship between the smell and certain selected attributes of each molecule was examined by various pattern recognition techniques using programs developed in the Department of Computer Chemistry at Rzeszów University of Technology.

  14. The quantum-chemical determination of group contributions to the thermodynamic properties of organophosphorus compounds

    Science.gov (United States)

    Dorofeeva, O. V.; Ryzhova, O. N.; Moiseeva, N. F.

    2008-06-01

    The enthalpies of formation, entropies, and heat capacities of 95 organophosphorus derivatives calculated by nonempirical quantum-chemical methods were used to develop the additive method for estimating the thermodynamic properties of these compounds. 86 group contribution values were obtained for estimating the thermodynamic properties of diverse organic derivatives of phosphorus in the oxidation states 3 and 5 (three-and four-coordinate phosphorus atoms).

  15. Optical methods for creating delivery systems of chemical compounds to plant roots

    Science.gov (United States)

    Kuznetsov, Pavel E.; Rogacheva, Svetlana M.; Arefeva, Oksana A.; Minin, Dmitryi V.; Tolmachev, Sergey A.; Kupadze, Machammad S.

    2004-08-01

    Spectrophotometric and fluorescence methods have been used for creation and investigation of various systems of target delivery of chemical compounds to roots of plants. The possibility of using liposomes, incrusted by polysaccharides of the external surface of nitrogen-fixing rizospheric bacteria Azospirillum brasilense SP 245, and nanoparticles incrusted by polysaccharides of wheat roots, as the named systems has been shown. The important role of polysaccharide-polysaccharide interaction in the adsorption processes of bacteria on wheat roots has been demonstrated.

  16. Chemical hydrogenation of La(Fe,Si) family of intermetallic compounds

    Science.gov (United States)

    Wlodarczyk, P.; Polak, M.; Hawelek, L.; Kowalczyk, M.; Hreczka, M.; Kolano-Burian, A.

    2016-11-01

    In the present work, the chemical hydrogenation process of La(Fe,Si)13 compounds has been shown. It was found, that the La(Fe,Si) compound can be easily saturated with hydrogen by performing reaction with 0.6 M hydrochloric acid (HCl) for 2 h. After reaction, the heat treatment process is necessary to make hydrogenated powder homogenous. For the LaFe11.8Si1.2 micronized (induction up to 2T. The adiabatic temperature change is equal to 3 K in magnetic field change 0-1.7T at 335 K, while magnetic entropy change is equal 13 J/kg*K at 2T. The structural homogeneity of initial and hydrogenated powders was validated by powder X-ray diffraction method. The amount of hydrogen in the hydrogenated compounds was evaluated using thermogravimetry method (4 H atoms per formula unit LaFe11.8Si1.2).

  17. Solvent Extraction of Chemical Attribution Signature Compounds from Painted Wall Board: Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Wahl, Jon H.; Colburn, Heather A.

    2009-10-29

    This report summarizes work that developed a robust solvent extraction procedure for recovery of chemical attribution signature (CAS) compound dimethyl methyl phosphonate (DMMP) (as well as diethyl methyl phosphonate (DEMP), diethyl methyl phosphonothioate (DEMPT), and diisopropyl methyl phosphonate (DIMP)) from painted wall board (PWB), which was selected previously as the exposed media by the chemical attribution scientific working group (CASWG). An accelerated solvent extraction approach was examined to determine the most effective method of extraction from PWB. Three different solvent systems were examined, which varied in solvent strength and polarity (i.e., 1:1 dichloromethane : acetone,100% methanol, and 1% isopropanol in pentane) with a 1:1 methylene chloride : acetone mixture having the most robust and consistent extraction for four original target organophosphorus compounds. The optimum extraction solvent was determined based on the extraction efficiency of the target analytes from spiked painted wallboard as determined by gas chromatography x gas chromatography mass spectrometry (GCxGC-MS) analysis of the extract. An average extraction efficiency of approximately 60% was obtained for these four compounds. The extraction approach was further demonstrated by extracting and detecting the chemical impurities present in neat DMMP that was vapor-deposited onto painted wallboard tickets.

  18. Quantitative global studies of reactomes and metabolomes using a vectorial representation of reactions and chemical compounds

    Directory of Open Access Journals (Sweden)

    Triviño Juan C

    2010-04-01

    Full Text Available Abstract Background Global studies of the protein repertories of organisms are providing important information on the characteristics of the protein space. Many of these studies entail classification of the protein repertory on the basis of structure and/or sequence similarities. The situation is different for metabolism. Because there is no good way of measuring similarities between chemical reactions, there is a barrier to the development of global classifications of "metabolic space" and subsequent studies comparable to those done for protein sequences and structures. Results In this work, we propose a vectorial representation of chemical reactions, which allows them to be compared and classified. In this representation, chemical compounds, reactions and pathways may be represented in the same vectorial space. We show that the representation of chemical compounds reflects their physicochemical properties and can be used for predictive purposes. We use the vectorial representations of reactions to perform a global classification of the reactome of the model organism E. coli. Conclusions We show that this unsupervised clustering results in groups of enzymes more coherent in biological terms than equivalent groupings obtained from the EC hierarchy. This hierarchical clustering produces an optimal set of 21 groups which we analyzed for their biological meaning.

  19. Modulation of alternative splicing with chemical compounds in new therapeutics for human diseases.

    Science.gov (United States)

    Ohe, Kenji; Hagiwara, Masatoshi

    2015-04-17

    Alternative splicing is a critical step where a limited number of human genes generate a complex and diverse proteome. Various diseases, including inherited diseases with abnormalities in the "genome code," have been found to result in an aberrant mis-spliced "transcript code" with correlation to the resulting phenotype. Chemical compound-based and nucleic acid-based strategies are trying to target this mis-spliced "transcript code". We will briefly mention about how to obtain splicing-modifying-compounds by high-throughput screening and overview of what is known about compounds that modify splicing pathways. The main focus will be on RNA-binding protein kinase inhibitors. In the main text, we will refer to diseases where splicing-modifying-compounds have been intensively investigated, with comparison to nucleic acid-based strategies. The information on their involvement in mis-splicing as well as nonsplicing events will be helpful in finding better compounds with less off-target effects for future implications in mis-splicing therapy.

  20. Deciphering potential chemical compounds of gaseous oxidized mercury in Florida, USA

    Science.gov (United States)

    Huang, Jiaoyan; Miller, Matthieu B.; Edgerton, Eric; Sexauer Gustin, Mae

    2017-02-01

    The highest mercury (Hg) wet deposition in the United States of America (USA) occurs along the Gulf of Mexico, and in the southern and central Mississippi River Valley. Gaseous oxidized Hg (GOM) is thought to be a major contributor due to high water solubility and reactivity. Therefore, it is critical to understand concentrations, potential for wet and dry deposition, and GOM compounds present in the air. Concentrations and dry-deposition fluxes of GOM were measured and calculated for Naval Air Station Pensacola Outlying Landing Field (OLF) in Florida using data collected by a Tekran® 2537/1130/1135, the University of Nevada Reno Reactive Mercury Active System (UNRRMAS) with cation exchange and nylon membranes, and the Aerohead samplers that use cation-exchange membranes to determine dry deposition. Relationships with Tekran®-derived data must be interpreted with caution, since the GOM concentrations measured are biased low depending on the chemical compounds in air and interferences with water vapor and ozone.Criteria air pollutants were concurrently measured. This allowed for comparison and better understanding of GOM.In addition to other methods previously applied at OLF, use of the UNRRMAS provided a platform for determination of the chemical compounds of GOM in the air. Results from nylon membranes with thermal desorption analyses indicated seven GOM compounds in this area, including HgBr2, HgCl2, HgO, Hg-nitrogen and sulfur compounds, and two unknown compounds. This indicates that the site is influenced by different gaseous phase reactions and sources. Using back-trajectory analysis during a high-GOM event related to high CO, but average SO2, indicated air parcels moved from the free troposphere and across Arkansas, Mississippi, and Alabama at low elevation (compounds. Overall, GOM chemistry indicates oxidation reactions with local mobile source pollutants and long-range transport.In order to develop methods to measure GOM concentrations and chemistry, and

  1. Chemical reactivity and biological activity of chalcones and other α,β-unsaturated carbonyl compounds.

    Science.gov (United States)

    Maydt, Daniela; De Spirt, Silke; Muschelknautz, Christian; Stahl, Wilhelm; Müller, Thomas J J

    2013-08-01

    Abstract 1. Chalcones are structural analogues of benzalacetophenone (BAP). Several derivatives have been identified in plants and anticarcinogenic and anti-inflammatory properties were attributed to the compounds, probably related to their direct antioxidant activity or stimulatory effects on the expression of endogenous defence enzymes like hemeoxygenase-1 (HO-1). HO-1 expression is triggered by the Nrf2-Keap1 signalling pathway, initiated by the addition of chalcones to thiol groups of Keap1 via Michael-type reaction. 2. The present study used a model system estimating the reactivity of different synthetic chalcones and other α,β-unsaturated carbonyl compounds with thiols and compared the chemical reactivity with the biological activity, measured by HO-1 expression in human dermal fibroblasts. 3. Chemical reactivity with the thiol group of N-acetylcysteine was determined with 5,5'-dithiobis-(2-nitrobenzoic acid) and followed chemical principles of structure-reactivity relationship. Most reactive were sulforaphane, dimethylfumarate, chalcone 3 ((2E)-1-phenyl-3-pyrimidin-2-ylprop-2-en-1-one) and chalcone 7 (1,3-diphenylprop-2-yn-1-one). This result demonstrates that α,β-unsaturated carbonyl derivatives react with thiols differently. All compounds were also biologically active; however, expression of HO-1 was not only related to the chemical reactivity but also to the lipophilicity of the molecules which likely affected transmembrane uptake. Most efficient inducers of HO-1 expression were BAP, 4-hydroxynonenal and chalcone 1 (4-[(1E)-3-oxo-3-phenylprop-1-en-1-yl]benzonitrile), chalcone 5 ((2E)-1-phenyl-3-[4-(trifluoromethyl)-phenyl]prop-2-en-1-one) and chalcone 7.

  2. Reduction of Nitroaromatic Compounds on the Surface of Metallic Iron: Quantum Chemical Study

    Directory of Open Access Journals (Sweden)

    Jerzy Leszczynski

    2002-07-01

    Full Text Available Abstract: The initial reduction steps of nitroaromatic compounds on the surface of metallic iron have been studied theoretically using nitrobenzene (NB as a representative of nitroaromatic compounds. The quantum chemical cluster approximation within the semiempirical Neglect of Diatomic Differential Overlap for Metal Compounds method was applied to model the Fe(110 crystallographic surface, taken as a representative reactive surface for granular iron. This surface was modeled as a 39-atom two-layer metal cluster with rigid geometry. The associative and dissociative adsorption of nitrobenzene was considered. Based on our quantum chemical analysis, we suggest that the direct electron donation from the metal surface into the π* orbital of NB is a decisive factor responsible for subsequent transformation of the nitro group. Molecularly adsorbed NB interacts with metal iron exclusively through nitro moiety oxygens which occupy tri-coordinated positions on surface The charge transfer from metal to NB of approximately 2 atomic units destablizes the nitro group. As a result, the first dissociation of the N-O bond goes through a relatively low activation barrier. The adsorbed nitrosobenzene is predicted to be a stable surface species, though still quiet labile.

  3. Design and characterization of chemical space networks for different compound data sets.

    Science.gov (United States)

    Zwierzyna, Magdalena; Vogt, Martin; Maggiora, Gerald M; Bajorath, Jürgen

    2015-02-01

    Chemical Space Networks (CSNs) are generated for different compound data sets on the basis of pairwise similarity relationships. Such networks are thought to complement and further extend traditional coordinate-based views of chemical space. Our proof-of-concept study focuses on CSNs based upon fingerprint similarity relationships calculated using the conventional Tanimoto similarity metric. The resulting CSNs are characterized with statistical measures from network science and compared in different ways. We show that the homophily principle, which is widely considered in the context of social networks, is a major determinant of the topology of CSNs of bioactive compounds, designed as threshold networks, typically giving rise to community structures. Many properties of CSNs are influenced by numerical features of the conventional Tanimoto similarity metric and largely dominated by the edge density of the networks, which depends on chosen similarity threshold values. However, properties of different CSNs with constant edge density can be directly compared, revealing systematic differences between CSNs generated from randomly collected or bioactive compounds.

  4. In situ Analysis of Organic Compounds on Mars using Chemical Derivatization and Gas Chromatography Mass Spectrometry

    Science.gov (United States)

    Glavin, D. P.; Buch, A.; Cabane, M.; Coll, P.; Navarro-Gonzalez, R.; Mahaffy, P. R.

    2005-01-01

    One of the core science objectives of NASA's 2009 Mars Science Laboratory (MSL) mission is to determine the past or present habitability of Mars. The search for key organic compounds relevant to terrestrial life will be an important part of that assessment. We have developed a protocol for the analysis of amino acids and carboxylic acids in Mars analogue materials using gas chromatography mass spectrometry (GCMS). As shown, a variety of carboxylic acids were readily identified in soil collected from the Atacama Desert in Chile at part-per-billion levels by GCMS after extraction and chemical derivatization using the reagent N,N-tert.-butyl (dimethylsilyl) trifluoroacetamide (MTBSTFA). Several derivatized amino acids including glycine and alanine were also detected by GCMS in the Atacama soil at lower concentrations (chromatogram not shown). Lacking derivatization capability, the Viking pyrolysis GCMS instruments could not have detected amino acids and carboxylic acids, since these non-volatile compounds require chemical transformation into volatile species that are stable in a GC column. We are currently optimizing the chemical extraction and derivatization technique for in situ GCMS analysis on Mars. Laboratory results of analyses of Atacama Desert samples and other Mars analogue materials using this protocol will be presented.

  5. Real-time monitoring of volatile organic compounds using chemical ionization mass spectroscopy: Final report

    Energy Technology Data Exchange (ETDEWEB)

    Thornberg, S.M.; Mowry, C.D.; Keenan, M.R.; Bender, S.F.A. [Sandia National Labs., Albuquerque, NM (United States). Gas Analysis Lab.; Owen, T. [Intel Corp., Rio Rancho, NM (United States)

    1997-04-01

    Volatile organic compound (VOC) emission to the atmosphere is of great concern to semiconductor manufacturing industries, research laboratories, the public, and regulatory agencies. Some industries are seeking ways to reduce emissions by reducing VOCs at the point of use (or generation). This paper discusses the requirements, design, calibration, and use of a sampling inlet/quadrupole mass spectrometer system for monitoring VOCs in a semiconductor manufacturing production line. The system uses chemical ionization to monitor compounds typically found in the lithography processes used to manufacture semiconductor devices (e.g., acetone, photoresist). The system was designed to be transportable from tool to tool in the production line and to give the operator real-time feedback so the process(es) can be adjusted to minimize VOC emissions. Detection limits ranging from the high ppb range for acetone to the low ppm range fore other lithography chemicals were achieved using chemical ionization mass spectroscopy at a data acquisition rate of approximately 1 mass spectral scan (30 to 200 daltons) per second. A demonstration of exhaust VOC monitoring was performed at a working semiconductor fabrication facility during actual wafer processing.

  6. Diversity selection of compounds based on 'protein affinity fingerprints' improves sampling of bioactive chemical space.

    Science.gov (United States)

    Nguyen, Ha P; Koutsoukas, Alexios; Mohd Fauzi, Fazlin; Drakakis, Georgios; Maciejewski, Mateusz; Glen, Robert C; Bender, Andreas

    2013-09-01

    Diversity selection is a frequently applied strategy for assembling high-throughput screening libraries, making the assumption that a diverse compound set increases chances of finding bioactive molecules. Based on previous work on experimental 'affinity fingerprints', in this study, a novel diversity selection method is benchmarked that utilizes predicted bioactivity profiles as descriptors. Compounds were selected based on their predicted activity against half of the targets (training set), and diversity was assessed based on coverage of the remaining (test set) targets. Simultaneously, fingerprint-based diversity selection was performed. An original version of the method exhibited on average 5% and an improved version on average 10% increase in target space coverage compared with the fingerprint-based methods. As a typical case, bioactivity-based selection of 231 compounds (2%) from a particular data set ('Cutoff-40') resulted in 47.0% and 50.1% coverage, while fingerprint-based selection only achieved 38.4% target coverage for the same subset size. In conclusion, the novel bioactivity-based selection method outperformed the fingerprint-based method in sampling bioactive chemical space on the data sets considered. The structures retrieved were structurally more acceptable to medicinal chemists while at the same time being more lipophilic, hence bioactivity-based diversity selection of compounds would best be combined with physicochemical property filters in practice.

  7. [Emission characteristics and hazard assessment analysis of volatile organic compounds from chemical synthesis pharmaceutical industry].

    Science.gov (United States)

    Li, Yan; Wang, Zhe-Ming; Song, Shuang; Xu, Zhi-Rong; Xu, Ming-Zhu; Xu, Wei-Li

    2014-10-01

    In this study, volatile organic compounds (VOCs) released from chemical synthesis pharmaceutical industry in Taizhou, Zhejiang province were analyzed quantitatively and qualitatively. The total volatile organic compounds (TVOCs) was in the range of 14.9-308.6 mg · m(-3). Evaluation models of ozone formation potentials (OFP) and health risk assessment were adopted to preliminarily assess the environmental impact and health risk of VOCs. The results showed that the values of OFP of VOCs were in the range of 3.1-315.1 mg · m(-3), based on the maximum incremental reactivity, the main principal contribution was toluene, tetrahydrofuran (THF), acetic ether etc. The non-carcinogenic risk and the carcinogen risk fell in the ranges of 9.48 x 10(-7)-4.98 x 10(-4) a(-1) and 3.17 x 10(-5)- 6.33 x 10(-3). The principal contribution of VOCs was benzene, formaldehyde and methylene chloride.

  8. Technology Development and Production of Certain Chemical Platinum Metals Compounds at JSC "Krastsvetmet"

    Institute of Scientific and Technical Information of China (English)

    ILYASHEVICH V.D.; PAVLOVA E.I.; KORITSKAYA N.G.; MAMONOV S.N.; SHULGIN D.R.; MALTSEV E.V.

    2012-01-01

    In recent years JSC "Krastsvetmet" has successfully developed the production of chemically pure compounds of precious metals.Currently methods have been developed and facilities have been provided for industrial production of the following platinum metals compounds:- Rhodium (Ⅲ) chloride hydrate,rhodium (Ⅲ) chloride solution,rhodium ( Ⅲ) nitrate solution,rhodium ( Ⅲ)iodide,rhodium ( Ⅲ) sulfate,hydrated rhodium ( Ⅲ) oxide,ammonium hexachlororodiate,rhodium ( Ⅲ)phosphate solution,rhodium electrolytes;Iridium (Ⅳ) chloride hydrate,iridium (Ⅲ) chloride hydrate,ammonium hexachloroiridate (Ⅳ),hexachloriridium acid solution,hexachloriridium crystalline acid;- Ruthenium (Ⅲ) chloride hydrate,ruthenium (Ⅳ) hydroxide chloride,ruthenium (Ⅳ) hydroxide chloride solution,ammonium hexachlororuthenate,ruthenium (Ⅲ) chloride solution,potassium,diaquaoctachloronitrido diruthenate.The quality of the production meets the requirements of Russian and foreign consumers.

  9. Estrogenicity profile and estrogenic compounds determined in river sediments by chemical analysis, ELISA and yeast assays.

    Science.gov (United States)

    Viganò, Luigi; Benfenati, Emilio; van Cauwenberge, Anne; Eidem, Janne K; Erratico, Claudio; Goksøyr, Anders; Kloas, Werner; Maggioni, Silvia; Mandich, Alberta; Urbatzka, Ralph

    2008-10-01

    An effects-directed strategy was applied to bed sediments of a polluted tributary in order to isolate and identify the major estrogenic chemicals it discharges into the River Po, the principal Italian watercourse. Sediment extract was concentrated by solid phase extraction and then fractioned into 10 fractions by reversed phase high performance liquid chromatography (RP-HPLC). Estrogenic activity of whole extract and fractions were determined using a recombinant yeast assay containing the human estrogen receptor (YES). The 10 fractions and whole extract were analysed for target compounds, e.g. estrone (E1), 17beta-estradiol (E2), estriol (E3), 4-nonylphenol (NP), 4-tert-octylphenol (t-OP), bisphenol A (BPA), using both liquid chromatography-tandem mass spectrometry (LC-MS/MS) and non-competitive enzyme-linked immunosorbent assays (ELISA). The YES assay determined high estrogenic activity in whole sediment (15.6 ng/g EE2 equivalents), and positive results for fractions nr 1, 2, 6, 7 and 8. E1, E3 and NP were the main estrogenic chemicals, however, other unidentified compounds contributed to sediment estrogenicity, particularly for polar fractions nr 1 and 2. A GC-MS screening performed in scan mode identified other potential contributors such as phthalates (DBP, BBP), and OP isomers. A next sampling campaign extended to other tributaries and receiving stretches of the River Po confirmed E1, E3 and NP as major estrogenic chemicals potentially threatening other sites of the main river. In general, target compound ELISAs have been shown to be suitable tools for a rapid screening of wide areas or large numbers of environmental samples for estrogenic risk. The potential for interferences suggests however to use cautiously the concentration values obtained from some of the immunoassays.

  10. Psychoactive plants described in a Brazilian literary work and their chemical compounds.

    Science.gov (United States)

    Otsuka, Rafaela Denise; Lago, João Henrique Ghilardi; Rossi, Lucia; Galduróz, José Carlos Fernandes; Rodrigues, Eliana

    2010-09-01

    Ethnopharmacological research investigates the plants and other medicinal and toxic substances utilized by different traditional populations. One approach in this field is a literature search of the available publications on medicinal plants. The purpose of the current study was to select plants with psychoactive effects described in a Brazilian literary work written by Pio Correa in 1926. Those mentioned plants were classified in accordance with their indications for use as stimulants and depressors of the central nervous system. For the phytochemical study herein, we researched these species via a database search, and all the obtained information was compiled into a new database to analyze possible correlations between the chemical compounds and the psychoactive categories. Of the 813 plants searched in the literary work, 104 presented chemical data in the scientific periodicals consulted. Seventy-five of them belong to the stimulant category, while 31 are depressors and two of them belong to both categories. Phenols and flavonoids were the main compounds observed in plants of both categories, though at different frequencies. Monoterpenes (29.9%) and sesquiterpenes (28.6%) were also observed in plants from the stimulant category, while 25.8% of plants from the depressor category were comprised of carotenoids and 22.6% of steroids. The main specific compounds were identified as ferulic acid, α-pinene, limonene, α-humulene and kaempferol among the stimulant plants. Otherwise, in depressor plants were characterized caffeic acid, kaempferol, quercetin, β-carotene, physalins and withanolides as specific compounds. The association between ethnopharmacological and chemotaxonomic data, as presented in this study, could support plant selection in further investigations by research groups whose studies focus on psychoactive plants as potential therapeutics.

  11. [Simultaneous determination of chlorhexidine acetate and benzalkonium chloride in compound chemical disinfectants by capillary electrophoresis].

    Science.gov (United States)

    Song, Baohua; Ding, Xiaojing; Li, Jia; Wang, Zhi

    2012-09-01

    Benzalkonium chloride (BAC) is a mixture of alkyl substituted benzyl dimethylammonium chloride homologs (C12-BAC, C14-BAC and C16-BAC). Chlorhexidine acetate is a widely used effective component in compound chemical disinfectants. A method for the simultaneous determination of chlorhexidine acetate and benzalkonium chloride in compound chemical disinfectants by capillary electrophoresis (CE) was established. The CE analysis was carried out using an uncoated capillary with 50 microm i. d. and 37 cm total length. The running buffer was 150 mmol/L NaH2PO4-62.5 mmol/L H3PO4 (pH 2.5) containing 40% (v/v) acetonitrile. The sample medium was 50 mmol/L acetic acid-acetonitrile (1:1, v/v). The detection wavelength was 214 nm. The factors such as the buffer concentration and pH, the content of acetonitrile, which influenced the separation and accurate assay of compound chemical disinfectants were investigated in detail. The intra-day and inter-day precisions of the method were below 3. 0% and 3.7%, respectively. The limits of detection (LOD, signal to noise ratio (S/N) = 3) for chlorhexidine acetate, C12-BAC, Cl4-BAC and C16-BAC were 0. 3, 0.5, 0.5 and 0.5 mg/L, respectively. The limits of quantification (LOQ, S/N = 10) were 1.0, 1.5, 1.5, and 1.5 mg/L, respectively. The corrected peak area and the mass concentration of the four components mentioned above showed good linear relationships within the ranges of 1.0 - 400 mg/L, 1. 5 - 200 mg/L, 1.5 - 200 mg/L and 1.5 - 200 mg/L, with linear correlation coefficients (r) of 0.9995, 0.9998, 0.999 7 and 0.9998, respectively. The established method was used for the determination of the four disinfectants in the compound chemical disinfectants. The results were in good agreement with those obtained by the high performance liquid chromatographic method.

  12. Predicting physical-chemical properties of compounds from molecular structures by recursive neural networks.

    Science.gov (United States)

    Bernazzani, Luca; Duce, Celia; Micheli, Alessio; Mollica, Vincenzo; Sperduti, Alessandro; Starita, Antonina; Tiné, Maria Rosaria

    2006-01-01

    In this paper, we report on the potential of a recently developed neural network for structures applied to the prediction of physical chemical properties of compounds. The proposed recursive neural network (RecNN) model is able to directly take as input a structured representation of the molecule and to model a direct and adaptive relationship between the molecular structure and target property. Therefore, it combines in a learning system the flexibility and general advantages of a neural network model with the representational power of a structured domain. As a result, a completely new approach to quantitative structure-activity relationship/quantitative structure-property relationship (QSPR/QSAR) analysis is obtained. An original representation of the molecular structures has been developed accounting for both the occurrence of specific atoms/groups and the topological relationships among them. Gibbs free energy of solvation in water, Delta(solv)G degrees , has been chosen as a benchmark for the model. The different approaches proposed in the literature for the prediction of this property have been reconsidered from a general perspective. The advantages of RecNN as a suitable tool for the automatization of fundamental parts of the QSPR/QSAR analysis have been highlighted. The RecNN model has been applied to the analysis of the Delta(solv)G degrees in water of 138 monofunctional acyclic organic compounds and tested on an external data set of 33 compounds. As a result of the statistical analysis, we obtained, for the predictive accuracy estimated on the test set, correlation coefficient R = 0.9985, standard deviation S = 0.68 kJ mol(-1), and mean absolute error MAE = 0.46 kJ mol(-1). The inherent ability of RecNN to abstract chemical knowledge through the adaptive learning process has been investigated by principal components analysis of the internal representations computed by the network. It has been found that the model recognizes the chemical compounds on the

  13. Country-specific chemical signatures of persistent environmental compounds in breast milk

    DEFF Research Database (Denmark)

    Krysiak-Baltyn, Konrad; Toppari, J.; Skakkebaek, N.E.;

    2010-01-01

    Recent reports have confirmed a worldwide increasing trend of testicular cancer incidence, and a conspicuously high prevalence of this disease and other male reproductive disorders, including cryptorchidism and hypospadias, in Denmark. In contrast, Finland, a similarly industrialized Nordic country......, exhibits much lower incidences of these disorders. The reasons behind the observed trends are unexplained, but environmental endocrine disrupting chemicals (EDCs) that affect foetal testis development are probably involved. Levels of persistent chemicals in breast milk can be considered a proxy...... for exposure of the foetus to such agents. Therefore, we undertook a comprehensive ecological study of 121 EDCs, including the persistent compounds dioxins, polychlorinated biphenyls (PCBs), pesticides and flame retardants, and non-persistent phthalates, in 68 breast milk samples from Denmark and Finland...

  14. Molecular descriptor data explain market prices of a large commercial chemical compound library

    Science.gov (United States)

    Polanski, Jaroslaw; Kucia, Urszula; Duszkiewicz, Roksana; Kurczyk, Agata; Magdziarz, Tomasz; Gasteiger, Johann

    2016-06-01

    The relationship between the structure and a property of a chemical compound is an essential concept in chemistry guiding, for example, drug design. Actually, however, we need economic considerations to fully understand the fate of drugs on the market. We are performing here for the first time the exploration of quantitative structure-economy relationships (QSER) for a large dataset of a commercial building block library of over 2.2 million chemicals. This investigation provided molecular statistics that shows that on average what we are paying for is the quantity of matter. On the other side, the influence of synthetic availability scores is also revealed. Finally, we are buying substances by looking at the molecular graphs or molecular formulas. Thus, those molecules that have a higher number of atoms look more attractive and are, on average, also more expensive. Our study shows how data binning could be used as an informative method when analyzing big data in chemistry.

  15. Molecular descriptor data explain market prices of a large commercial chemical compound library.

    Science.gov (United States)

    Polanski, Jaroslaw; Kucia, Urszula; Duszkiewicz, Roksana; Kurczyk, Agata; Magdziarz, Tomasz; Gasteiger, Johann

    2016-06-23

    The relationship between the structure and a property of a chemical compound is an essential concept in chemistry guiding, for example, drug design. Actually, however, we need economic considerations to fully understand the fate of drugs on the market. We are performing here for the first time the exploration of quantitative structure-economy relationships (QSER) for a large dataset of a commercial building block library of over 2.2 million chemicals. This investigation provided molecular statistics that shows that on average what we are paying for is the quantity of matter. On the other side, the influence of synthetic availability scores is also revealed. Finally, we are buying substances by looking at the molecular graphs or molecular formulas. Thus, those molecules that have a higher number of atoms look more attractive and are, on average, also more expensive. Our study shows how data binning could be used as an informative method when analyzing big data in chemistry.

  16. Chemical constituents from red algae Bostrychia radicans (Rhodomelaceae): new amides and phenolic compounds

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Ana Ligia Leandrini de; Silva, Denise B. da; Lopes, Norberto P.; Debonsi, Hosana M. [Universidade de Sao Paulo (FCFRP/USP), Ribeirao Preto, SP (Brazil). Fac. de Ciencias Farmaceuticas de Ribeirao Preto. Dept. de Quimica e Fisica; Yokoya, Nair S., E-mail: hosana@fcfrp.usp.br [Instituto de Botanica, Sao Paulo, SP (Brazil). Secao de Ficologia

    2012-07-01

    This study describes the isolation and structural determination of two amides, isolated for the first time: N,4-dihydroxy-N-(2'-hydroxyethyl)-benzamide (0.019%) and N,4-dihydroxy-N-(2'-hydroxyethyl)-benzeneacetamide (0.023%). These amides, produced by the red macroalgae Bostrychia radicans, had their structures assigned by NMR spectral data and MS analyses. In addition, this chemical study led to the isolation of cholesterol, heptadecane, squalene, trans-phytol, neophytadiene, tetradecanoic and hexadecanoic acids, methyl hexadecanoate and methyl 9-octadecenoate, 4-(methoxymethyl)-phenol, 4-hydroxybenzaldehyde, methyl 4-hydroxybenzeneacetate, methyl 2-hydroxy-3-(4-hydroxyphenyl)-propanoate, hydroquinone, methyl 4-hydroxymandelate, methyl 4-hydroxybenzoate, 4-hydroxybenzeneacetic acid and (4-hydroxyphenyl)-oxo-acetaldehyde. This is the first report concerning these compounds in B. radicans, contributing by illustrating the chemical diversity within the Rhodomelaceae family. (author)

  17. Chemical constituents from red algae Bostrychia radicans (Rhodomelaceae: new amides and phenolic compounds

    Directory of Open Access Journals (Sweden)

    Ana Lígia Leandrini de Oliveira

    2012-01-01

    Full Text Available This study describes the isolation and structural determination of two amides, isolated for the first time: N,4-dihydroxy-N-(2'-hydroxyethyl-benzamide (0.019% and N,4-dihydroxy-N-(2'-hydroxyethyl-benzeneacetamide (0.023%. These amides, produced by the red macroalgae Bostrychia radicans, had their structures assigned by NMR spectral data and MS analyses. In addition, this chemical study led to the isolation of cholesterol, heptadecane, squalene, trans-phytol, neophytadiene, tetradecanoic and hexadecanoic acids, methyl hexadecanoate and methyl 9-octadecenoate, 4-(methoxymethyl-phenol, 4-hydroxybenzaldehyde, methyl 4-hydroxybenzeneacetate, methyl 2-hydroxy-3-(4-hydroxyphenyl-propanoate, hydroquinone, methyl 4-hydroxymandelate, methyl 4-hydroxybenzoate, 4-hydroxybenzeneacetic acid and (4-hydroxyphenyl-oxo-acetaldehyde. This is the first report concerning these compounds in B. radicans, contributing by illustrating the chemical diversity within the Rhodomelaceae family.

  18. Modeling the Detection of Organic and Inorganic Compounds Using Iodide-Based Chemical Ionization.

    Science.gov (United States)

    Iyer, Siddharth; Lopez-Hilfiker, Felipe; Lee, Ben H; Thornton, Joel A; Kurtén, Theo

    2016-02-04

    Iodide-based chemical ionization mass spectrometry (CIMS) has been used to detect and measure concentrations of several atmospherically relevant organic and inorganic compounds. The significant electronegativity of iodide and the strong acidity of hydroiodic acid makes electron transfer and proton abstraction essentially negligible, and the soft nature of the adduct formation ionization technique reduces the chances of sample fragmentation. In addition, iodide has a large negative mass defect, which, when combined with the high resolving power of a high resolution time-of-flight chemical ionization mass spectrometer (HR-ToF-CIMS), provides good selectivity. In this work, we use quantum chemical methods to calculate the binding energies, enthalpies and free energies for clusters of an iodide ion with a number of atmospherically relevant organic and inorganic compounds. Systematic configurational sampling of the free molecules and clusters was carried out at the B3LYP/6-31G* level, followed by subsequent calculations at the PBE/SDD and DLPNO-CCSD(T)/def2-QZVPP//PBE/aug-cc-pVTZ-PP levels. The binding energies, enthalpies, and free energies thus obtained were then compared to the iodide-based University of Washington HR-ToF-CIMS (UW-CIMS) instrument sensitivities for these molecules. We observed a reasonably linear relationship between the cluster binding enthalpies and logarithmic instrument sensitivities already at the PBE/SDD level, which indicates that relatively simple quantum chemical methods can predict the sensitivity of an iodide-based CIMS instrument toward most molecules. However, higher level calculations were needed to treat some outlier molecules, most notably oxalic acid and methylerythritol. Our calculations also corroborated the recent experimental findings that the molecules that the UW-CIMS detects at maximum sensitivity usually have binding enthalpies to iodide which are higher than about 26 kcal/mol, depending slightly on the level of theory.

  19. Analytical applications of oscillatory chemical reactions: determination of some pharmaceuticaly and biologically important compounds

    Directory of Open Access Journals (Sweden)

    Pejić Nataša D.

    2012-01-01

    Full Text Available Novel analytical methods for quantitive determination of analytes based on perturbations of oscillatory chemical reactions realized under open reactor conditions (continuosly fed well stirred tank reactor, CSTR, have been developed in the past twenty years. The proposed kinetic methods are generally based on the ability of the analyzed substances to change the kinetics of the chemical reactions matrix. The unambiguous correlation of quantitative characteristics of perturbations, and the amount (concentration of analyte expressed as a regression equation, or its graphics (calibration curve, enable the determination of the unknown analyte concentration. Attention is given to the development of these methods because of their simple experimental procedures, broad range of linear regression ( 10-7 10-4 mol L-1 and low limits of detection of analytes ( 10-6 10-8 mol L1, in some cases even lower than 10-12 mol L-1. Therefore, their application is very convenient for routine analysis of various inorganic and organic compounds as well as gases. This review summarizes progress made in the past 5 years on quantitative determination of pharmaceutically and biologically important compounds.

  20. On the prediction of thermal stability of nitroaromatic compounds using quantum chemical calculations

    Energy Technology Data Exchange (ETDEWEB)

    Fayet, Guillaume [Laboratoire d' Electrochimie et Chimie Analytique, CNRS UMR-7575, Ecole Nationale Superieure de Chimie de Paris, 11 rue P. et M. Curie, 75231 Paris Cedex 05 (France); Institut National de l' Environnement Industriel et des Risques (INERIS), Parc Technologique Alata, BP2, 60550 Verneuil-en-Halatte (France); Rotureau, Patricia, E-mail: patricia.rotureau@ineris.fr [Institut National de l' Environnement Industriel et des Risques (INERIS), Parc Technologique Alata, BP2, 60550 Verneuil-en-Halatte (France); Joubert, Laurent; Adamo, Carlo [Laboratoire d' Electrochimie et Chimie Analytique, CNRS UMR-7575, Ecole Nationale Superieure de Chimie de Paris, 11 rue P. et M. Curie, 75231 Paris Cedex 05 (France)

    2009-11-15

    This work presents a new approach to predict thermal stability of nitroaromatic compounds based on quantum chemical calculations and on quantitative structure-property relationship (QSPR) methods. The data set consists of 22 nitroaromatic compounds of known decomposition enthalpy (taken as a macroscopic property related to explosibility) obtained from differential scanning calorimetry. Geometric, electronic and energetic descriptors have been selected and computed using density functional theory (DFT) calculation to describe the 22 molecules. First approach consisted in looking at their linear correlations with the experimental decomposition enthalpy. Molecular weight, electrophilicity index, electron affinity and oxygen balance appeared as the most correlated descriptors (respectively R{sup 2} = 0.76, 0.75, 0.71 and 0.64). Then multilinear regression was computed with these descriptors. The obtained model is a six-parameter equation containing descriptors all issued from quantum chemical calculations. The prediction is satisfactory with a correlation coefficient R{sup 2} of 0.91 and a predictivity coefficient R{sub cv}{sup 2} of 0.84 using a cross validation method.

  1. Element and chemical compounds transfer in bio-crude from hydrothermal liquefaction of microalgae.

    Science.gov (United States)

    Tang, Xiaohan; Zhang, Chao; Li, Zeyu; Yang, Xiaoyi

    2016-02-01

    In this study, hydrothermal liquefaction (HTL) experiments of Nannochloropsis and Spirulina were carried out at different temperatures (220-300 °C) to explore the effects of temperature on bio-crude yield and properties. The optimal temperature for bio-crude yield was around 260-280 °C. Transfers of element and chemical compounds in bio-crude were discussed in detail to deduce the reaction mechanism. The hydrogen and carbon recoveries were consistent with the results of bio-crude yields at every temperature point. The relative percentage of fatty acid in bio-crude decreased and the amine and amide increased for both microalgae with temperature rising. The N-heterocyclic compounds in bio-crude increased with temperature rising for Nannochloropsis, while decreased when temperature increased from 220 °C to 280 °C for Spirulina. Bio-crude gained at higher temperature or from microalgae with high protein content may contain high heteroatom compounds.

  2. Novel Data Mining Methods for Virtual Screening of Biological Active Chemical Compounds

    KAUST Repository

    Soufan, Othman M.

    2016-11-23

    Drug discovery is a process that takes many years and hundreds of millions of dollars to reveal a confident conclusion about a specific treatment. Part of this sophisticated process is based on preliminary investigations to suggest a set of chemical compounds as candidate drugs for the treatment. Computational resources have been playing a significant role in this part through a step known as virtual screening. From a data mining perspective, availability of rich data resources is key in training prediction models. Yet, the difficulties imposed by big expansion in data and its dimensionality are inevitable. In this thesis, I address the main challenges that come when data mining techniques are used for virtual screening. In order to achieve an efficient virtual screening using data mining, I start by addressing the problem of feature selection and provide analysis of best ways to describe a chemical compound for an enhanced screening performance. High-throughput screening (HTS) assays data used for virtual screening are characterized by a great class imbalance. To handle this problem of class imbalance, I suggest using a novel algorithm called DRAMOTE to narrow down promising candidate chemicals aimed at interaction with specific molecular targets before they are experimentally evaluated. Existing works are mostly proposed for small-scale virtual screening based on making use of few thousands of interactions. Thus, I propose enabling large-scale (or big) virtual screening through learning millions of interaction while exploiting any relevant dependency for a better accuracy. A novel solution called DRABAL that incorporates structure learning of a Bayesian Network as a step to model dependency between the HTS assays, is showed to achieve significant improvements over existing state-of-the-art approaches.

  3. Determining the chemical activity of hydrophobic organic compounds in soil using polymer coated vials

    Directory of Open Access Journals (Sweden)

    Jönsson Jan-Åke

    2008-05-01

    Full Text Available Abstract Background In soils contaminated by hydrophobic organic compounds, the concentrations are less indicative of potential exposure and distribution than are the associated chemical activities, fugacities and freely dissolved concentrations. The latter can be measured by diffusive sampling into thin layers of polymer, as in, for example, solid phase micro-extraction. Such measurements require equilibrium partitioning of analytes into the polymer while ensuring that the sample is not depleted. We introduce the validation of these requirements based on parallel sampling into polymer layers of different thicknesses. Results Equilibrium sampling devices were made by coating glass vials internally with 3–12 μm thick layers of polydimethylsiloxane (PDMS. These were filled with slurries of a polluted soil and gently agitated for 5 days. The concentrations of 7 polycyclic aromatic hydrocarbons (PAHs in the PDMS were measured. Validation confirmed fulfilment of the equilibrium sampling requirements and high measurement precision. Finally, chemical activities of the PAHs in the soil were determined from their concentrations and activity coefficients in the PDMS. Conclusion PAHs' thermodynamic activities in a soil test material were determined via a method of uptake into PDMS. This can be used to assess chemical exposure and predict diffusion and partitioning processes.

  4. IN SILICO SCREENING OF CHEMICAL COMPOUNDS FROM SWEET FLAG (ARACUS CALAMUS L AS α-GLUCOSIDASE INHIBITOR

    Directory of Open Access Journals (Sweden)

    Dewi Yuliana

    2013-03-01

    Full Text Available Research have been conducted screening in silico chemical compound inhibitor α-glucosidase from plants dringo (Acorus calamus L based on the binding site (binding site are owned by some of the compounds obtained respectively from the inhibition of enzyme / receptor (docking using the program Argus Lab. Model of the enzyme α-glucosidase was obtained through the protein data bank with the code 1lwj in the donwload NCBI website. Models of chemical compounds contained in dringo (A. Calamus L obtained through the site Take out "jamu" Knapsack and made in the formula structures of 2D and 3D using the program ACD / Chemsketch. Docking results showed activity in the compound 1-ethenyl-1-methyl-2,4-at (prop-1-en-2-yl Cyclohexane with free energy - 8.04385 kcal / mol, and the compound Isocaespitol with a free energy - 8.28388 kcal / mol.

  5. Inferring Alcoholism SNPs and Regulatory Chemical Compounds Based on Ensemble Bayesian Network.

    Science.gov (United States)

    Chen, Huan; Sun, Jiatong; Jiang, Hong; Wang, Xianyue; Wu, Lingxiang; Wu, Wei; Wang, Qh

    2016-12-20

    The disturbance of consciousness is one of the most common symptoms of those have alcoholism and may cause disability and mortality. Previous studies indicated that several single nucleotide polymorphisms (SNP) increase the susceptibility of alcoholism. In this study, we utilized the Ensemble Bayesian Network (EBN) method to identify causal SNPs of alcoholism based on the verified GAW14 data. Thirteen out of eighteen SNPs directly connected with alcoholism were found concordance with potential risk regions of alcoholism in OMIM database. As a number of SNPs were found contributing to alteration on gene expression, known as expression quantitative trait loci (eQTLs), we further sought to identify chemical compounds acting as regulators of alcoholism genes captured by causal SNPs. Chloroprene and valproic acid were identified as the expression regulators for genes C11orf66 and SALL3 which were captured by alcoholism SNPs, respectively.

  6. Can Coffee Chemical Compounds and Insecticidal Plants Be Harnessed for Control of Major Coffee Pests?

    Science.gov (United States)

    Green, Paul W C; Davis, Aaron P; Cossé, Allard A; Vega, Fernando E

    2015-11-01

    Pests and pathogens threaten coffee production worldwide and are difficult to control using conventional methods, such as insecticides. We review the literature on the chemistry of coffee, concentrating on compounds most commonly reported from Coffea arabica and Coffea canephora. Differences in chemistry can distinguish coffee species and varieties, and plants grown under different biogeographic conditions exhibit different chemotypes. A number of chemical groups, such as alkaloids and caffeoylquinic acids, are known to be insecticidal, but most studies have investigated their effects on coffee quality and flavor. More research is required to bridge this gap in knowledge, so that coffee can be bred to be more resistant to pests. Furthermore, we report on some pesticidal plants that have been used for control of coffee pests. Locally sourced pesticidal plants have been underutilized and offer a sustainable alternative to conventional insecticides and could be used to augment breeding for resilience of coffee plants.

  7. Salinity effect on nutritional value, chemical composition and bioactive compounds content of Cichorium spinosum L.

    Science.gov (United States)

    Petropoulos, Spyridon A; Levizou, Efi; Ntatsi, Georgia; Fernandes, Ângela; Petrotos, Konstantinos; Akoumianakis, Konstantinos; Barros, Lillian; Ferreira, Isabel C F R

    2017-01-01

    Soil salinization is an increasing problem for many areas throughout the world that renders prohibitive vegetables and crop production in general. In the present study, Cichorium spinosum L. plants were grown under saline conditions in order to evaluate chemical composition and bioactive compounds content of their leaves. Salinity increase resulted in significant changes of macro and micro-nutrients content (nutritional value, sugars, fatty acids, minerals, ascorbic acid and tocopherols), whereas the concentration of phenolic compounds was not significantly affected. Chicoric and 5-O-caffeoylquinic acid were the most abundant phenolic acids. In contrast, antioxidant activity and mineral composition were beneficially affected by mid-to-high and high salinity levels. In conclusion, C. spinosum can be cultivated under saline conditions without compromising the quality of the final product, especially in semi-arid areas where irrigation water is scarce and/or of low quality due to high content of NaCl (coastal areas or areas where underground water is saline).

  8. Chemical composition, fatty acid profile and bioactive compounds of guava seeds (Psidium guajava L.

    Directory of Open Access Journals (Sweden)

    Ana Maria Athayde Uchôa-thomaz

    2014-09-01

    Full Text Available This study aimed to characterize the chemical composition, determine the fatty acid profile, and quantify the bioactive compounds present in guava seed powder (Psidium guajava L.. The powder resulted from seeds obtained from guava pulp processing. The agro-industrial seeds from red guava cv. paluma were used, and they were donated by a frozen pulp fruit manufacturer. They contain varying amounts of macronutrients and micronutrients, with a high content of total dietary fiber (63.94 g/100g, protein (11.19 g/100g, iron (13.8 mg/100g, zinc (3.31 mg/100g, and reduced calorie content (182 kcal/100g. Their lipid profile showed a predominance of unsaturated fatty acids (87.06%, especially linoleic acid (n6 and oleic acid (n9. The powder obtained contained significant amounts of bioactive compounds such as ascorbic acid (87.44 mg/100g, total carotenoids (1.25 mg/100 g and insoluble dietary fiber (63.55 g/100g. With regard to their microbiological quality, the samples were found suitable for consumption. Based on these results, it can be concluded that the powder produced has favorable attributes for industrial use, and that use of these seeds would be a viable alternative to prevent various diseases and malnutrition in our country and to reduce the environmental impact of agricultural waste.

  9. Nonlinear chemical reaction between Na2S2O3 and Peroxide compound

    Institute of Scientific and Technical Information of China (English)

    高庆宇; 汪跃民; 王贵昌; 张松林; 臧雅茹; 赵学庄

    1997-01-01

    Kinetics of reaction between Na2S2O3 and peroxide compound ( H2O2 or Na2S2O8) in a batch reactor and in a continuous stirring tank reactor (CSTR) were studied.Steady oscillations in uncatalyzed reactions in a CSTR were first discovered.In Na2S2O3-H2O2-H2SO4 reaction system,Pt potential and pH of higher and lower flow rutes beyond oscillation flow rates were in around the same extreme values.The reaction catalyeed by Cu2+ corsist of the catalyzed oscillation process and the uncatalyzed osciliation one.On the basis of experiment,a reaction mechanism consisting of three stages was put forward.The three stages are H positive-feedback reactions,proton negative-feedba k (uncatalyzed negative-feedback and catalyzed negative-feedback) reactions and transitional reactions.The mechanism is able to explain reasonably the nonlinear chemical phenomena appearing in the thiosulfatc oxidation reaction by peroxide-compounds.

  10. Effect of chemical degradation on fluxes of reactive compounds – a study with a stochastic Lagrangian transport model

    Directory of Open Access Journals (Sweden)

    J. Rinne

    2012-06-01

    Full Text Available In the analyses of VOC fluxes measured above plant canopies, one usually assumes the flux above canopy to equal the exchange at the surface. Thus one assumes the chemical degradation to be much slower than the turbulent transport. We used a stochastic Lagrangian transport model in which the chemical degradation was described as first order decay in order to study the effect of the chemical degradation on above canopy fluxes of chemically reactive species. With the model we explored the sensitivity of the ratio of the above canopy flux to the surface emission on several parameters such as chemical lifetime of the compound, friction velocity, stability, and canopy density. Our results show that friction velocity and chemical lifetime affected the loss during transport the most. The canopy density had a significant effect if the chemically reactive compound was emitted from the forest floor. We used the results of the simulations together with oxidant data measured during HUMPPA-COPEC-2010 campaign at a Scots pine site to estimate the effect of the chemistry on fluxes of three typical biogenic VOCs, isoprene, α-pinene, and β-caryophyllene. Of these, the chemical degradation had a major effect on the fluxes of the most reactive species β-caryophyllene, while the fluxes of α-pinene were affected during nighttime. For these two compounds representing the mono- and sesquiterpenes groups, the effect of chemical degradation had also a significant diurnal cycle with the highest chemical loss at night. The different day and night time loss terms need to be accounted for, when measured fluxes of reactive compounds are used to reveal relations between primary emission and environmental parameters.

  11. Development of a Wireless and Passive SAW-Based Chemical Sensor for Organophosphorous Compound Detection

    Directory of Open Access Journals (Sweden)

    Fang-Qian Xu

    2015-12-01

    Full Text Available A new wireless and passive surface acoustic wave (SAW-based chemical sensor for organophosphorous compound (OC detection is presented. A 434 MHz reflective delay line configuration composed by single phase unidirectional transducers (SPUDTs and three shorted reflectors was fabricated on YZ LiNbO3 piezoelectric substrate as the sensor element. A thin fluoroalcoholpolysiloxane (SXFA film acted as the sensitive interface deposited onto the SAW propagation path between the second and last reflectors of the SAW device. The first reflector was used for the temperature compensation utilizing the difference method. The adsorption between the SXFA and OC molecules modulates the SAW propagation, especially for the time delay of the SAW, hence, the phase shifts of the reflection peaks from the corresponding reflectors can be used to characterize the target OC. Prior to the sensor fabrication, the coupling of modes (COM and perturbation theory were utilized to predict the SAW device performance and the gas adsorption. Referring to a frequency-modulated continuous wave (FMCW-based reader unit, the developed SAW chemical sensor was wirelessly characterized in gas exposure experiments for dimethylmethylphosphonate (DMMP detection. Sensor performance parameters such as phase sensitivity, repeatability, linearity, and temperature compensation were evaluated experimentally.

  12. Chemical evolution of volatile organic compounds in the outflow of the Mexico City Metropolitan area

    Energy Technology Data Exchange (ETDEWEB)

    Apel, E.; Springston, S.; Karl, T.; Emmons, L.; Flocke, F.; Hills, A. J.; Madronich, S.; Lee-Taylor, J.; Fried, A.; Weibring, P.; Walega, J.; Richter, D., Tie, X.; Mauldin, L.; Campos, T.; Sive, B.; Kleinman, L.; Springston, S., Zaveri, R.; deGouw, J.; Zheng, J.; Zhang, R.; Rudolph, J.; Junkermann, W.; Riemer, D. D.

    2009-11-01

    The volatile organic compound (VOC) distribution in the Mexico City Metropolitan Area (MCMA) and its evolution as it is uplifted and transported out of the MCMA basin was studied during the 2006 MILAGRO/MIRAGE-Mex field campaign. The results show that in the morning hours in the city center, the VOC distribution is dominated by non-methane hydrocarbons (NMHCs) but with a substantial contribution from oxygenated volatile organic compounds (OVOCs), predominantly from primary emissions. Alkanes account for a large part of the NMHC distribution in terms of mixing ratios. In terms of reactivity, NMHCs also dominate overall, especially in the morning hours. However, in the afternoon, as the boundary layer lifts and air is mixed and aged within the basin, the distribution changes as secondary products are formed. The WRF-Chem (Weather Research and Forecasting with Chemistry) model and MOZART (Model for Ozone and Related chemical Tracers) were able to reproduce the general features of the daytime cycle of the VOC OH reactivity distribution showing that NMHCs dominate the distribution except in the afternoon hours and that the VOC OH reactivity peaks in the early morning due to high morning emissions from the city into a shallow boundary layer. The WRF-Chem and MOZART models showed higher reactivity than the experimental data during the nighttime cycle, perhaps indicating problems with the modeled nighttime boundary layer height. In addition, a plume was studied in which air was advected out of the MCMA and intercepted downwind with the DOE G1 on 18 March and the NCAR C130 one day later on 19 March. A number of identical species measured aboard each aircraft gave insight into the chemical evolution of the plume as it aged and was transported as far as 1000 km downwind. Ozone and many OVOCs were photochemically produced in the plume. The WRF-Chem and MOZART models were used to examine the spatial and temporal extent of the 19 March plume and to help interpret the OH

  13. Chemical evolution of volatile organic compounds in the outflow of the Mexico City Metropolitan area

    Directory of Open Access Journals (Sweden)

    E. C. Apel

    2010-03-01

    Full Text Available The volatile organic compound (VOC distribution in the Mexico City Metropolitan Area (MCMA and its evolution as it is uplifted and transported out of the MCMA basin was studied during the 2006 MILAGRO/MIRAGE-Mex field campaign. The results show that in the morning hours in the city center, the VOC distribution is dominated by non-methane hydrocarbons (NMHCs but with a substantial contribution from oxygenated volatile organic compounds (OVOCs, predominantly from primary emissions. Alkanes account for a large part of the NMHC distribution in terms of mixing ratios. In terms of reactivity, NMHCs also dominate overall, especially in the morning hours. However, in the afternoon, as the boundary layer lifts and air is mixed and aged within the basin, the distribution changes as secondary products are formed. The WRF-Chem (Weather Research and Forecasting with Chemistry model and MOZART (Model for Ozone and Related chemical Tracers were able to approximate the observed MCMA daytime patterns and absolute values of the VOC OH reactivity. The MOZART model is also in agreement with observations showing that NMHCs dominate the reactivity distribution except in the afternoon hours. The WRF-Chem and MOZART models showed higher reactivity than the experimental data during the nighttime cycle, perhaps indicating problems with the modeled nighttime boundary layer height.

    A northeast transport event was studied in which air originating in the MCMA was intercepted aloft with the Department of Energy (DOE G1 on 18 March and downwind with the National Center for Atmospheric Research (NCAR C130 one day later on 19 March. A number of identical species measured aboard each aircraft gave insight into the chemical evolution of the plume as it aged and was transported as far as 1000 km downwind; ozone was shown to be photochemically produced in the plume. The WRF-Chem and MOZART models were used to examine the spatial extent and temporal evolution of the plume

  14. Chemical evolution of volatile organic compounds in the outflow of the Mexico City Metropolitan area

    Directory of Open Access Journals (Sweden)

    W. Junkermann

    2009-11-01

    Full Text Available The volatile organic compound (VOC distribution in the Mexico City Metropolitan Area (MCMA and its evolution as it is uplifted and transported out of the MCMA basin was studied during the 2006 MILAGRO/MIRAGE-Mex field campaign. The results show that in the morning hours in the city center, the VOC distribution is dominated by non-methane hydrocarbons (NMHCs but with a substantial contribution from oxygenated volatile organic compounds (OVOCs, predominantly from primary emissions. Alkanes account for a large part of the NMHC distribution in terms of mixing ratios. In terms of reactivity, NMHCs also dominate overall, especially in the morning hours. However, in the afternoon, as the boundary layer lifts and air is mixed and aged within the basin, the distribution changes as secondary products are formed. The WRF-Chem (Weather Research and Forecasting with Chemistry model and MOZART (Model for Ozone and Related chemical Tracers were able to reproduce the general features of the daytime cycle of the VOC OH reactivity distribution showing that NMHCs dominate the distribution except in the afternoon hours and that the VOC OH reactivity peaks in the early morning due to high morning emissions from the city into a shallow boundary layer. The WRF-Chem and MOZART models showed higher reactivity than the experimental data during the nighttime cycle, perhaps indicating problems with the modeled nighttime boundary layer height. In addition, a plume was studied in which air was advected out of the MCMA and intercepted downwind with the DOE G1 on 18~March and the NCAR C130 one day later on 19~March. A number of identical species measured aboard each aircraft gave insight into the chemical evolution of the plume as it aged and was transported as far as 1000 km downwind. Ozone and many OVOCs were photochemically produced in the plume. The WRF-Chem and MOZART models were used to examine the spatial and temporal extent of the 19~March plume and to help interpret

  15. Chemical evolution of volatile organic compounds in the outflow of the Mexico City Metropolitan area

    Energy Technology Data Exchange (ETDEWEB)

    Apel, Eric; Emmons, L.; Karl, Thomas G.; Flocke, Frank M.; Hills, A. J.; Madronich, Sasha; Lee-Taylor, J.; Fried, Alan; Weibring, P.; Walega, J.; Richter, Dirk; Tie, X.; Mauldin, L.; Campos, Teresa; Weinheimer, Andrew J.; Knapp, David; Sive, B.; Kleinman, Lawrence I.; Springston, S.; Zaveri, Rahul A.; Ortega, John V.; Voss, Paul B.; Blake, D. R.; Baker, Angela K.; Warneke, Carsten; Welsh-Bon, Daniel; de Gouw, Joost A.; Zheng, J.; Zhang, Renyi; Rudolph, Jochen; Junkermann, W.; Riemer, D.

    2010-01-01

    The volatile organic compound (VOC) distribution in the Mexico City Metropolitan Area (MCMA) and its evolution as it is uplifted and transported out of the MCMA basin was studied during the 2006 MILAGRO/MIRAGE-Mex field campaign. The results show that in the morning hours in the city center, the VOC distribution is dominated by non-methane hydrocarbons (NMHCs) but with a substantial contribution from oxygenated volatile organic compounds (OVOCs), predominantly from primary emissions. Alkanes account for a large part of the NMHC distribution in terms of mixing ratios. In terms of reactivity, NMHCs also dominate overall, especially in the morning hours. However, in the afternoon, as the boundary layer lifts and air is mixed and aged within the basin, the distribution changes as secondary products are formed. The WRF-Chem (Weather Research and Forecasting with Chemistry) model and MOZART (Model for Ozone and Related chemical Tracers) were able to reproduce the general features of the daytime cycle of the VOC OH reactivity distribution showing that NMHCs dominate the distribution except in the afternoon hours and that the VOC OH reactivity peaks in the early morning due to high morning emissions from the city into a shallow boundary layer. The WRF-Chem and MOZART models showed higher reactivity than the experimental data during the nighttime cycle, perhaps indicating problems with the modeled nighttime boundary layer height. In addition, a plume was studied in which air was advected out of the MCMA and intercepted downwind with the DOE G1 on March 18 and the NCAR C130 one day later on March 19. A number of identical species measured aboard each aircraft gave insight into the chemical evolution of the plume as it aged and was transported as far as 1000 km downwind. Ozone and many OVOCs were photochemically produced in the plume. The WRF-Chem and MOZART models were used to examine the spatial and temporal extent of the March 19 plume and to help interpret the OH

  16. Evaluating the correlation between chemical and sensory compounds in Blaufränkisch and Cabernet Franc wines

    Directory of Open Access Journals (Sweden)

    Irina Balga

    2014-12-01

    Full Text Available The positive physiological effects of the bioactive compounds of red wines have been known for a long time. Besides that, the polyphenolic compounds of red wines represent one of the most important factors for oenology. With a special chemical analysis, we discover the relationship between chemical and sensory compounds. In this way, we explore which compounds influence sensory properties. The phenolic compounds are the quality attributes of the wine. The analysis of phenolic compounds was carried out in two red wines: Cabernet Franc and Blaufränkisch. The aim of this study was to analyse the chemical and organoleptic characteristics of these two wines and evaluate the connection between the two parameters. In addition, we also examined the influence of the polyphenolic content on sensory perception. The experiment was carried out in a cool climate wine region in Eger, Hungary, in vintage of 2008. We investigated the profile of phenolic contents in new and aged wines. Total polyphenolic content, anthocyanin, leucoanthocyanin and catechin were evaluated by spectrophotometer. Stilbenes were identified and quantified by high-performance liquid chromatography.

  17. Electrocatalytic processing of renewable biomass-derived compounds for production of chemicals, fuels and electricity

    Science.gov (United States)

    Xin, Le

    The dual problems of sustaining the fast growth of human society and preserving the environment for future generations urge us to shift our focus from exploiting fossil oils to researching and developing more affordable, reliable and clean energy sources. Human beings had a long history that depended on meeting our energy demands with plant biomass, and the modern biorefinery technologies realize the effective conversion of biomass to production of transportation fuels, bulk and fine chemicals so to alleviate our reliance on fossil fuel resources of declining supply. With the aim of replacing as much non-renewable carbon from fossil oils with renewable carbon from biomass as possible, innovative R&D activities must strive to enhance the current biorefinery process and secure our energy future. Much of my Ph.D. research effort is centered on the study of electrocatalytic conversion of biomass-derived compounds to produce value-added chemicals, biofuels and electrical energy on model electrocatalysts in AEM/PEM-based continuous flow electrolysis cell and fuel cell reactors. High electricity generation performance was obtained when glycerol or crude glycerol was employed as fuels in AEMFCs. The study on selective electrocatalytic oxidation of glycerol shows an electrode potential-regulated product distribution where tartronate and mesoxalate can be selectively produced with electrode potential switch. This finding then led to the development of AEMFCs with selective production of valuable tartronate or mesoxalate with high selectivity and yield and cogeneration of electricity. Reaction mechanisms of electrocatalytic oxidation of ethylene glycol and 1,2-propanediol were further elucidated by means of an on-line sample collection technique and DFT modeling. Besides electro-oxidation of biorenewable alcohols to chemicals and electricity, electrocatalytic reduction of keto acids (e.g. levulinic acid) was also studied for upgrading biomass-based feedstock to biofuels while

  18. Removal mechanisms for endocrine disrupting compounds (EDCs) in wastewater treatment - physical means, biodegradation, and chemical advanced oxidation: a review.

    Science.gov (United States)

    Liu, Ze-Hua; Kanjo, Yoshinori; Mizutani, Satoshi

    2009-01-01

    Endocrine disrupting compounds (EDCs) are pollutants with estrogenic or androgenic activity at very low concentrations and are emerging as a major concern for water quality. Within the past few decades, more and more target chemicals were monitored as the source of estrogenic or androgenic activity in wastewater, and great endeavors have been done on the removal of EDCs in wastewater. This article reviewed removal of EDCs from three aspects, that is, physical means, biodegradation, and chemical advanced oxidation (CAO).

  19. Modifications in the chemical compounds and sensorial attributes of Engraulis anchoita fillet during marinating process

    Directory of Open Access Journals (Sweden)

    Maria Isabel Yeannes

    2008-12-01

    Full Text Available Marinated fish are fish products preserved by the combined action of salt and organic acids. The objective of this work was to analyze the variations in the chemical compounds of anchovy fillets that give them sensorial characteristics during the marinating process of Engraulis anchoita. The protein content decreased slightly and the TVB-N level decreased significantly in both the brining and marinating stages. In the marinating stage an increase in the total free aminoacids was observed. The NBV level in the brining and marinating solutions increased during these stages due to the solubilization of the non-protein nitrogenous compounds and the degradation of some protein compounds.The decrease of the contents of protein and TVB-N, and the increase of the acidity and the free aminoacids content during the marinating process give the marinated fillets the characteristic texture and aroma.Peixes marinados são produtos obtidos pela ação combinada de sal e ácidos orgânicos. O presente estudo teve como objetivo avaliar as alterações químicas e sensoriais em filés de anchoita (Engraulis anchoita durante o processo de marinado. O conteúdo de proteína apresentou decréscimo significativo durante a salga. O teor de Bases Voláteis Totais-N-BVT, apresentou uma diminuição considerável durante a salga e marinacão. Na fase de marinado, foi observado um aumento em aminoácidos livres totais. Foi constatada a presença de N-BVT na salmoura e na solução oriunda do processo de obtenção de marinado, devido à solubilização de nitrogênio não protéico, que podem ter sido acrescidos de alguns compostos de degradação protéica. A redução do conteúdo de proteína e N-BVT e o aumento de acidez e de aminoácidos livres gerados durante ou processo de elaboração do marinado fazem com que os filés marinados adquiram textura e aroma característicos.

  20. A detailed chemical kinetic model for pyrolysis of the lignin model compound chroman

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    James Bland

    2013-12-01

    Full Text Available The pyrolysis of woody biomass, including the lignin component, is emerging as a potential technology for the production of renewable fuels and commodity chemicals. Here we describe the construction and implementation of an elementary chemical kinetic model for pyrolysis of the lignin model compound chroman and its reaction intermediate ortho-quinone methide (o-QM. The model is developed using both experimental and theoretical data, and represents a hybrid approach to kinetic modeling that has the potential to provide molecular level insight into reaction pathways and intermediates while accurately describing reaction rates and product formation. The kinetic model developed here can replicate all known aspects of chroman pyrolysis, and provides new information on elementary reaction steps. Chroman pyrolysis is found to proceed via an initial retro-Diels–Alder reaction to form o-QM + ethene (C2H4, followed by dissociation of o-QM to the C6H6 isomers benzene and fulvene (+ CO. At temperatures of around 1000–1200 K and above fulvene rapidly isomerizes to benzene, where an activation energy of around 270 kJ mol-1 is required to reproduce experimental observations. A new G3SX level energy surface for the isomerization of fulvene to benzene supports this result. Our modeling also suggests that thermal decomposition of fulvene may be important at around 950 K and above. This study demonstrates that theoretical protocols can provide a significant contribution to the development of kinetic models for biomass pyrolysis by elucidating reaction mechanisms, intermediates, and products, and also by supplying realistic rate coefficients and thermochemical properties.

  1. Antibacterial activity and chemical compounds of leaves and branches of Protium hebetatum

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    G.G. CONRADO

    2015-01-01

    Full Text Available ABSTRACT The extracts and fractions of leaves and branches of Protium hebetatum D. C. Daly (Burseraceae were investigated for their antibacterial activity and chemical composition. The methanol extract of branches (EMG was considered active against the Escherichia coli and the Proteus vulgaris, showing an inhibition zone of 13 mm, and was selected for bioassay-guided phytochemical fractionation. From the technique of broth microdilution, the extract was considered a moderate inhibitor against Staphylococcus aureus, Pseudomonas aeruginosa and Enterococcus faecalis, with a minimum inhibitory concentration (MIC of 1 mg/mL. The dichloromethane fraction was considered a moderate inhibitor against S. aureus (MIC of 1 mg/mL and a potent inhibitor against E. faecalis (MIC of 0.5 mg/mL. F1, F2, F5 and F6 from chromatographic column of dichloromethane fraction were considered moderate inhibitors against S. aureus (MIC of 1 mg/mL. Through analysis by a gas chromatography mass spectrometry, eighteen compounds were identified, from which thirteen (isoeugenol, p-vinylguaiacol, metoxyeugenol, coumarin, 5-hydroxy-scopoletin, 4,7-dihydroxy-6-metoxicromam-2-one, 4[(1E]-3-hydroxy-1-propenyl-2-methoxyphenol, piperonal, scoparon, o-guaiacol, spathulenol, seringol and antiarol are unprecedented in these species. We also identified the triterpenes α-amyrin and β-amyrin, the steroids stigmasterol and sitosterol and the coumarin scopoletin, which was closely linked to the antibacterial activity of the samples.

  2. Protocol for serial cultivation of epithelial cells without enzymes or chemical compounds.

    Science.gov (United States)

    Ye, Dongxia; Peramo, Antonio

    2014-01-01

    Deriving keratinocytes from epidermis or oral mucosa is a critical first step in the construction of cell-based tissue engineering and regenerative medicine applications. It would be advantageous to develop a methodology to grow adult somatic cells with maximum plasticity in a rapid fashion and in large numbers with minimal manipulation. With routine methods, keratinocytes are cultured in standard amount of medium and passaged with enzymes, and the confluence of the monolayer induces differentiation and eventual cell death. A protocol to expand keratinocytes in culture by growing keratinocyte in large numbers using a technique in which keratinocytes are released into the overlaying medium, effectively "popping-up" into suspension from the cell monolayer, is described in this chapter. This technique does not require the use of enzymes or chemical compounds for serial cultivation. The cells possess the ability of active cell proliferation at 100 % confluence over 1-2 months' time. Based on previous characterization reports, these are untransformed, normal keratinocytes that appear to be highly suitable for clinical applications.

  3. Chemical genetics reveals an RGS/G-protein role in the action of a compound.

    Directory of Open Access Journals (Sweden)

    Kevin Fitzgerald

    2006-04-01

    Full Text Available We report here on a chemical genetic screen designed to address the mechanism of action of a small molecule. Small molecules that were active in models of urinary incontinence were tested on the nematode Caenorhabditis elegans, and the resulting phenotypes were used as readouts in a genetic screen to identify possible molecular targets. The mutations giving resistance to compound were found to affect members of the RGS protein/G-protein complex. Studies in mammalian systems confirmed that the small molecules inhibit muscarinic G-protein coupled receptor (GPCR signaling involving G-alphaq (G-protein alpha subunit. Our studies suggest that the small molecules act at the level of the RGS/G-alphaq signaling complex, and define new mutations in both RGS and G-alphaq, including a unique hypo-adapation allele of G-alphaq. These findings suggest that therapeutics targeted to downstream components of GPCR signaling may be effective for treatment of diseases involving inappropriate receptor activation.

  4. Meteorological and Chemical Behavior of Gaseous Sulfur Compounds in and around an Urban Valley

    Directory of Open Access Journals (Sweden)

    Sang-Keun Song

    2010-01-01

    Full Text Available The effects of photochemical oxidation of reduced sulfur compounds (RSCs: H2S, CH3SH, DMS, and DMDS on SO2 production were evaluated at high (HV and low ventilation (LV conditions, based on a CALPUFF dispersion model coupled with photo-chemical oxidation mechanisms for four RSCs. The RSC emission concentrations used in the modeling were measured in and around an urban valley during a field campaign held in October 2008. SO2 production with LV (up to 156 ppb at 0900 LST was found to be significantly higher than that with HV (up to 30 ppb. SO2 produced by photochemical oxidation of RSCs with LV (78% of total SO2 concentrations was much higher than that with HV (27%, while the predominant RSC species were similar: DMDS (>= 60% of the total contributions with HV and LV when compared to three other RSCs (< 20%. The difference in SO2 concentration between HV and LV might be caused by the combined effects of photochemical oxidation of RSCs and ventilation condition.

  5. Characterization of traditional Istrian dry-cured ham by means of physical and chemical analyses and volatile compounds.

    Science.gov (United States)

    Marušić, Nives; Petrović, Marinko; Vidaček, Sanja; Petrak, Tomislav; Medić, Helga

    2011-08-01

    The aroma-active compounds of Istrian dry-cured ham were investigated by using headspace-solid phase microextraction and gas chromatography-mass spectrometry (GC-MS). Samples of biceps femoris were also evaluated by measuring physical and chemical characteristics: moisture, protein, fat, ash and NaCl content, a(w) value; colour: L*, a*, b* and oxidation of fat: TBARS test. About 50 volatile compounds were identified and quantified which belonged to several classes of chemical: 5 alcohols, 8 aldehydes, 7 alkanes, 1 ketone, 2 esters, 9 monoterpenes and 15 sesquiterpenes. Except volatile compounds derived from lipolysis and proteolysis the most abundant constituents were terpenes (62.97; 41.43%) that originate from spices added in the salting phase of the production process.

  6. A quantum chemical based toxicity study of estimated reduction potential and hydrophobicity in series of nitroaromatic compounds.

    Science.gov (United States)

    Gooch, A; Sizochenko, N; Sviatenko, L; Gorb, L; Leszczynski, J

    2017-02-01

    Nitroaromatic compounds and the products of their degradation are toxic to bacteria, cells and animals. Various studies have been carried out to better understand the mechanism of toxicity of aromatic nitrocompounds and their relationship to humans and the environment. Recent data relate cytotoxicity of nitroaromatic compounds to their single- or two-electron enzymatic reduction. However, mechanisms of animal toxicity could be more complex. This work investigates the estimated reduction and oxidation potentials of 34 nitroaromatic compounds using quantum chemical approaches. All geometries were optimized with density functional theory (DFT) using the solvation model based on density (SMD) and polarizable continuum model (PCM) solvent model protocols. Quantitative structure-activity/property (QSAR/QSPR) models were developed using descriptors obtained from quantum chemical optimizations as well as the DRAGON software program. The QSAR/QSPR equations developed consist of two to four descriptors. Correlations have been identified between electron affinity (ELUMO) and hydrophobicity (log P).

  7. Prediction of bioactive compound pathways using chemical interaction and structural information.

    Science.gov (United States)

    Cheng, Shiwen; Zhu, Changming; Chu, Chen; Huang, Tao; Kong, Xiangyin; Zhu, Liu Cun

    2016-01-01

    The functional screening of compounds is an important topic in chemistry and biomedicine that can uncover the essential properties of compounds and provide information concerning their correct use. In this study, we investigated the bioactive compounds reported in Selleckchem, which were assigned to 22 pathways. A computational method was proposed to identify the pathways of the bioactive compounds. Unlike most existing methods that only consider compound structural information, the proposed method adopted both the structural and interaction information from the compounds. The total accuracy achieved by our method was 61.79% based on jackknife analysis of a dataset of 1,832 bioactive compounds. Its performance was quite good compared with that of other machine learning algorithms (with total accuracies less than 46%). Finally, some of the false positives obtained by the method were analyzed to investigate the likelihood of compounds being annotated to new pathways.

  8. ToxAlerts: a Web server of structural alerts for toxic chemicals and compounds with potential adverse reactions.

    Science.gov (United States)

    Sushko, Iurii; Salmina, Elena; Potemkin, Vladimir A; Poda, Gennadiy; Tetko, Igor V

    2012-08-27

    The article presents a Web-based platform for collecting and storing toxicological structural alerts from literature and for virtual screening of chemical libraries to flag potentially toxic chemicals and compounds that can cause adverse side effects. An alert is uniquely identified by a SMARTS template, a toxicological endpoint, and a publication where the alert was described. Additionally, the system allows storing complementary information such as name, comments, and mechanism of action, as well as other data. Most importantly, the platform can be easily used for fast virtual screening of large chemical datasets, focused libraries, or newly designed compounds against the toxicological alerts, providing a detailed profile of the chemicals grouped by structural alerts and endpoints. Such a facility can be used for decision making regarding whether a compound should be tested experimentally, validated with available QSAR models, or eliminated from consideration altogether. The alert-based screening can also be helpful for an easier interpretation of more complex QSAR models. The system is publicly accessible and tightly integrated with the Online Chemical Modeling Environment (OCHEM, http://ochem.eu). The system is open and expandable: any registered OCHEM user can introduce new alerts, browse, edit alerts introduced by other users, and virtually screen his/her data sets against all or selected alerts. The user sets being passed through the structural alerts can be used at OCHEM for other typical tasks: exporting in a wide variety of formats, development of QSAR models, additional filtering by other criteria, etc. The database already contains almost 600 structural alerts for such endpoints as mutagenicity, carcinogenicity, skin sensitization, compounds that undergo metabolic activation, and compounds that form reactive metabolites and, thus, can cause adverse reactions. The ToxAlerts platform is accessible on the Web at http://ochem.eu/alerts, and it is constantly

  9. ANALYSIS OF MACRO AND MICROELEMENTS IN TEETH, SALIVA, AND BLOOD OF WORKERS IN FERGANA CHEMICAL PLANT OF FURAN COMPOUNDS

    Directory of Open Access Journals (Sweden)

    Sunnatillo Gaffarov

    2014-11-01

    Full Text Available This article aims to share the results of research conducted in the Fergana chemical plant of furan compounds (FCPFC in Uzbekistan.19 workers of the Furan compounds plant, in Fergana, Uzbekistan, were tested. By neutron activation analysis method, we have studied microelement composition of saliva, blood, dental hard tissue, and the level of Ca, Zn, Fe, and Ag in these subjects. We havedetected that the level of chemical elements in dental hard tissue, blood, and saliva of these workers was subject to negative changes as compared to the analysis results from those in the control group.The research results havepractical value for the prophylaxis, treatment, and health resumption of the people living in rugged ecological environment and workers who are engagedwith harmful substances in chemical industry.  Furthermore,this research also provides recommendations fortreatment of dental diseases related to common conditions of pathophysiological processes carried out bylivingorganisms.

  10. Predicting Heats of Explosion of Nitroaromatic Compounds through NBO Charges and 15N NMR Chemical Shifts of Nitro Groups

    Directory of Open Access Journals (Sweden)

    Ricardo Infante-Castillo

    2012-01-01

    Full Text Available This work presents a new quantitative model to predict the heat of explosion of nitroaromatic compounds using the natural bond orbital (NBO charge and 15N NMR chemical shifts of the nitro groups (15NNitro as structural parameters. The values of the heat of explosion predicted for 21 nitroaromatic compounds using the model described here were compared with experimental data. The prediction ability of the model was assessed by the leave-one-out cross-validation method. The cross-validation results show that the model is significant and stable and that the predicted accuracy is within 0.146 MJ kg−1, with an overall root mean squared error of prediction (RMSEP below 0.183 MJ kg−1. Strong correlations were observed between the heat of explosion and the charges (R2 = 0.9533 and 15N NMR chemical shifts (R2 = 0.9531 of the studied compounds. In addition, the dependence of the heat of explosion on the presence of activating or deactivating groups of nitroaromatic explosives was analyzed. All calculations, including optimizations, NBO charges, and 15NNitro NMR chemical shifts analyses, were performed using density functional theory (DFT and a 6-311+G(2d,p basis set. Based on these results, this practical quantitative model can be used as a tool in the design and development of highly energetic materials (HEM based on nitroaromatic compounds.

  11. Evaluation of the protective effect of chemical additives in the oxidation of phenolic compounds catalysed by peroxidase.

    Science.gov (United States)

    Torres, Juliana Arriel; Chagas, Pricila Maria Batista; Silva, Maria Cristina; Dos Santos, Custódio Donizete; Corrêa, Angelita Duarte

    2016-01-01

    The use of oxidoredutive enzymes in removing organic pollutants has been the subject of much research. The oxidation of phenolic compounds in the presence of chemical additives has been the focus of this study. In this investigation, the influence of the additives polyethylene glycol and Triton X-100 was evaluated in the phenol oxidation, caffeic acid, chlorogenic acid and total phenolic compounds present in coffee processing wastewater (CPW) at different pH values, performed by turnip peroxidase and peroxidase extracted from soybean seed hulls. The influence of these additives was observed only in the oxidation of phenol and caffeic acid. In the oxidation of other studied phenolic compounds, the percentage of oxidation remained unchanged in the presence of these chemical additives. In the oxidation of CPW in the presence of additives, no change in the oxidation of phenolic compounds was observed. Although several studies show the importance of evaluating the influence of additives on the behaviour of enzymes, this study found a positive response from the economic point of view for the treatment of real wastewater, since the addition of these substances showed no influence on the oxidation of phenolic compounds, which makes the process less costly.

  12. A Comparative Study of Two Quantum Chemical Descriptors in Predicting Toxicity of Aliphatic Compounds towards Tetrahymena pyriformis

    Directory of Open Access Journals (Sweden)

    Altaf Hussain Pandith

    2010-01-01

    Full Text Available Quantum chemical parameters such as LUMO energy, HOMO energy, ionization energy (I, electron affinity (A, chemical potential (μ, hardness (η electronegativity (χ, philicity (ωα, and electrophilicity (ω of a series of aliphatic compounds are calculated at the B3LYP/6-31G(d level of theory. Quantitative structure-activity relationship (QSAR models are developed for predicting the toxicity (pIGC50 of 13 classes of aliphatic compounds, including 171 electron acceptors and 81 electron donors, towards Tetrahymena pyriformis. The multiple linear regression modeling of toxicity of these compounds is performed by using the molecular descriptor log P (1-octanol/water partition coefficient in conjunction with two other quantum chemical descriptors, electrophilicity (ω and energy of the lowest unoccupied molecular orbital (ELUMO. A comparison is made towards the toxicity predicting the ability of electrophilicity (ω versus ELUMO as a global chemical reactivity descriptor in addition to log P. The former works marginally better in most cases. There is a slight improvement in the quality of regression by changing the unit of IGC50 from mg/L to molarity and by removing the racemates and the diastereoisomers from the data set.

  13. Chemical reaction networks as a model to describe UVC- and radiolytically-induced reactions of simple compounds.

    Science.gov (United States)

    Dondi, Daniele; Merli, Daniele; Albini, Angelo; Zeffiro, Alberto; Serpone, Nick

    2012-05-01

    When a chemical system is submitted to high energy sources (UV, ionizing radiation, plasma sparks, etc.), as is expected to be the case of prebiotic chemistry studies, a plethora of reactive intermediates could form. If oxygen is present in excess, carbon dioxide and water are the major products. More interesting is the case of reducing conditions where synthetic pathways are also possible. This article examines the theoretical modeling of such systems with random-generated chemical networks. Four types of random-generated chemical networks were considered that originated from a combination of two connection topologies (viz., Poisson and scale-free) with reversible and irreversible chemical reactions. The results were analyzed taking into account the number of the most abundant products required for reaching 50% of the total number of moles of compounds at equilibrium, as this may be related to an actual problem of complex mixture analysis. The model accounts for multi-component reaction systems with no a priori knowledge of reacting species and the intermediates involved if system components are sufficiently interconnected. The approach taken is relevant to an earlier study on reactions that may have occurred in prebiotic systems where only a few compounds were detected. A validation of the model was attained on the basis of results of UVC and radiolytic reactions of prebiotic mixtures of low molecular weight compounds likely present on the primeval Earth.

  14. Pupicidal and repellent activities of Pogostemon cablin essential oil chemical compounds against medically important human vector mosquitoes

    Science.gov (United States)

    Gokulakrishnan, J; Kuppusamy, Elumalai; Shanmugam, Dhanasekaran; Appavu, Anandan; Kaliyamoorthi, Krishnappa

    2013-01-01

    Objective To determine the repellent and pupicidal activities of Pogostemon cablin (P. cablin) chemical compositions were assayed for their toxicity against selected important vector mosquitoes, viz., Aedes aegypti (Ae. aegypti), Anopheles stephensi (An. stephensi) and Culex quinquefasciatus (Cx. quinquefasciatus) (Diptera: Culicidae). Methods The plants dry aerial parts were subjected to hydrodistillation using a modified Clevenger-type apparatus. The composition of the essential oil was analyzed by Gas Chromatography (GC) and GC mass spectrophotometry. Evaluation was carried out in a net cage (45 cm×30 cm×45 cm) containing 100 blood starved female mosquitoes and were assayed in the laboratory condition by using the protocol of WHO 2010. The repellent activity of P. cablin chemical compositions at concentration of 2mg/cm2were applied on skin of fore arm in man and exposed against adult female mosquitoes. The pupicidal activity was determined against selected important vector mosquitoes to concentration of 100 mg/L and mortality of each pupa was recorded after 24 h of exposure to the compounds. Results Chemical constituents of 15 compounds were identified in the oil of P.cablin compounds representing to 98.96%. The major components in essential oil were â-patchoulene, á-guaiene, ã-patchoulene, á-bulnesene and patchouli alcohol. The repellent activity of patchouli alcohol compound was found to be most effective for repellent activity and 2 mg/cm2 concentration provided 100% protection up to 280 min against Ae. aegypti, An. stephensi and Cx. quinquefasciatus, respectively. Similarly, pupae exposed to 100 mg/L concentrations of P. cablin chemical compositions. Among five compounds tested patchouli alcoholwas found to be most effective for pupicidal activity provided 28.44, 26.28 and 25.36 against Ae.aegypti, An.stephensi and Cx. quinquefasciatus, respectively. The percent adult emergence was inversely proportional to the concentration of compounds and directly

  15. Predicting Heats of Explosion of Nitroaromatic Compounds through NBO Charges and 15N NMR Chemical Shifts of Nitro Groups

    OpenAIRE

    Ricardo Infante-Castillo; Samuel P. Hernández-Rivera

    2012-01-01

    This work presents a new quantitative model to predict the heat of explosion of nitroaromatic compounds using the natural bond orbital (NBO) charge and 15N NMR chemical shifts of the nitro groups (15NNitro) as structural parameters. The values of the heat of explosion predicted for 21 nitroaromatic compounds using the model described here were compared with experimental data. The prediction ability of the model was assessed by the leave-one-out cross-validation method. The cross-validation re...

  16. Spectral imaging of chemical compounds using multivariate optically enhanced filters integrated with InGaAs VGA cameras

    Science.gov (United States)

    Priore, Ryan J.; Jacksen, Niels

    2016-05-01

    Infrared hyperspectral imagers (HSI) have been fielded for the detection of hazardous chemical and biological compounds, tag detection (friend versus foe detection) and other defense critical sensing missions over the last two decades. Low Size/Weight/Power/Cost (SWaPc) methods of identification of chemical compounds spectroscopy has been a long term goal for hand held applications. We describe a new HSI concept for low cost / high performance InGaAs SWIR camera chemical identification for military, security, industrial and commercial end user applications. Multivariate Optical Elements (MOEs) are thin-film devices that encode a broadband, spectroscopic pattern allowing a simple broadband detector to generate a highly sensitive and specific detection for a target analyte. MOEs can be matched 1:1 to a discrete analyte or class prediction. Additionally, MOE filter sets are capable of sensing an orthogonal projection of the original sparse spectroscopic space enabling a small set of MOEs to discriminate a multitude of target analytes. This paper identifies algorithms and broadband optical filter designs that have been demonstrated to identify chemical compounds using high performance InGaAs VGA detectors. It shows how some of the initial models have been reduced to simple spectral designs and tested to produce positive identification of such chemicals. We also are developing pixilated MOE compressed detection sensors for the detection of a multitude of chemical targets in challenging backgrounds/environments for both commercial and defense/security applications. This MOE based, real-time HSI sensor will exhibit superior sensitivity and specificity as compared to currently fielded HSI systems.

  17. Origin of the conformational modulation of the 13C NMR chemical shift of methoxy groups in aromatic natural compounds.

    Science.gov (United States)

    Toušek, Jaromír; Straka, Michal; Sklenář, Vladimír; Marek, Radek

    2013-01-24

    The interpretation of nuclear magnetic resonance (NMR) parameters is essential to understanding experimental observations at the molecular and supramolecular levels and to designing new and more efficient molecular probes. In many aromatic natural compounds, unusual (13)C NMR chemical shifts have been reported for out-of-plane methoxy groups bonded to the aromatic ring (~62 ppm as compared to the typical value of ~56 ppm for an aromatic methoxy group). Here, we analyzed this phenomenon for a series of aromatic natural compounds using Density Functional Theory (DFT) calculations. First, we checked the methodology used to optimize the structure and calculate the NMR chemical shifts in aromatic compounds. The conformational effects of the methoxy group on the (13)C NMR chemical shift then were interpreted by the Natural Bond Orbital (NBO) and Natural Chemical Shift (NCS) approaches, and by excitation analysis of the chemical shifts, breaking down the total nuclear shielding tensor into the contributions from the different occupied orbitals and their magnetic interactions with virtual orbitals. We discovered that the atypical (13)C NMR chemical shifts observed are not directly related to a different conjugation of the lone pair of electrons of the methoxy oxygen with the aromatic ring, as has been suggested. Our analysis indicates that rotation of the methoxy group induces changes in the virtual molecular orbital space, which, in turn, correlate with the predominant part of the contribution of the paramagnetic deshielding connected with the magnetic interactions of the BD(CMet-H)→BD*(CMet-OMet) orbitals, resulting in the experimentally observed deshielding of the (13)C NMR resonance of the out-of-plane methoxy group.

  18. Mining Molecular Pharmacological Effects from Biomedical Text: a Case Study for Eliciting Anti-Obesity/Diabetes Effects of Chemical Compounds.

    Science.gov (United States)

    Dura, Elzbieta; Muresan, Sorel; Engkvist, Ola; Blomberg, Niklas; Chen, Hongming

    2014-05-01

    In the pharmaceutical industry, efficiently mining pharmacological data from the rapidly increasing scientific literature is very crucial for many aspects of the drug discovery process such as target validation, tool compound selection etc. A quick and reliable way is needed to collect literature assertions of selected compounds' biological and pharmacological effects in order to assist the hypothesis generation and decision-making of drug developers. INFUSIS, the text mining system presented here, extracts data on chemical compounds from PubMed abstracts. It involves an extensive use of customized natural language processing besides a co-occurrence analysis. As a proof-of-concept study, INFUSIS was used to search in abstract texts for several obesity/diabetes related pharmacological effects of the compounds included in a compound dictionary. The system extracts assertions regarding the pharmacological effects of each given compound and scores them by the relevance. For each selected pharmacological effect, the highest scoring assertions in 100 abstracts were manually evaluated, i.e. 800 abstracts in total. The overall accuracy for the inferred assertions was over 90 percent.

  19. Development of corresponding states model for estimation of the surface tension of chemical compounds

    DEFF Research Database (Denmark)

    Gharagheizi, Farhad; Eslamimanesh, Ali; Sattari, Mehdi;

    2013-01-01

    include critical temperature or temperature/critical volume/acentric factor/critical pressure/reduced temperature/reduced normal boiling point temperature/molecular weight of the compounds. Around 1,300 surface tension data of 118 random compounds are used for developing the first model (a four...

  20. Changes on physico-chemical, textural, lipolysis and volatile compounds during the manufacture of dry-cured foal "cecina".

    Science.gov (United States)

    Lorenzo, José M

    2014-01-01

    The changes in the physico-chemical and textural properties, lipolysis and volatile compounds during the manufacture of dry-cured foal "cecina" were studied. The pH increased during the last stages of processing but gradually declined over the curing period. TBARS values, hardness and chewiness increased with processing time from 0.14, 2.74 and 0.83 to 3.49 mg malonaldehyde/kg, 20.33 kg and 5.05 kg∗mm, respectively. Ripening time also affected the colour parameters: lightness (L*), redness (a*) and yellowness (b*) (Pcecina", including esters, aldehydes, aliphatic hydrocarbons, branched hydrocarbons, alcohols, aromatic hydrocarbons, furans, ketones. Aldehydes reached their maximum level at the end of the post-salting stage. In the final product, esters became the dominant chemical compounds.

  1. A Quantum Chemical and Statistical Study of Cytotoxic Activity of Compounds Isolated from Curcuma zedoaria.

    Science.gov (United States)

    Hamdi, Omer Abdalla Ahmed; Anouar, El Hassane; Shilpi, Jamil A; Trabolsy, Zuhra Bashir Khalifa Al; Zain, Sharifuddin Bin Md; Zakaria, Nur Shahidatul Shida; Zulkefeli, Mohd; Weber, Jean-Frédéric F; Malek, Sri Nurestri A; Rahman, Syarifah Nur Syed Abdul; Awang, Khalijah

    2015-01-01

    A series of 21 compounds isolated from Curcuma zedoaria was subjected to cytotoxicity test against MCF7; Ca Ski; PC3 and HT-29 cancer cell lines; and a normal HUVEC cell line. To rationalize the structure-activity relationships of the isolated compounds; a set of electronic; steric and hydrophobic descriptors were calculated using density functional theory (DFT) method. Statistical analyses were carried out using simple and multiple linear regressions (SLR; MLR); principal component analysis (PCA); and hierarchical cluster analysis (HCA). SLR analyses showed that the cytotoxicity of the isolated compounds against a given cell line depend on certain descriptors; and the corresponding correlation coefficients (R2) vary from 0%-55%. MLR results revealed that the best models can be achieved with a limited number of specific descriptors applicable for compounds having a similar basic skeleton. Based on PCA; HCA and MLR analyses; active compounds were classified into subgroups; which was in agreement with the cell based cytotoxicity assay.

  2. Chemical reactivity of hypervalent silicon compounds: The local hard and soft acids and bases principle viewpoint

    Indian Academy of Sciences (India)

    Francisco Méndez; María De L Romero; José L Gazquez

    2005-09-01

    The silicon atom may increase its coordination number to values greater than four, to form pentacoordinated compounds. It has been observed experimentally that, in general, pentacoordinated compounds show greater reactivity than tetracoordinated compounds. In this work, density functional theory is used to calculate the global softness and the condensed softness of the silicon atom for SiHF4- and SiHF$^{1-}_{5-n}$. The values obtained show that the global and condensed softness are greater in the pentacoordinated compounds than in the tetracoordinated compounds, a result that explains the enhanced reactivity. If the results are analysed through a local version of the hard and soft acids and bases principle, it is possible to suggest that in nucleophilic substitution reactions, soft nucleophiles preferably react with SiHF$^{1-}_{5-n}$, and hard nucleophiles with SiHF4-.

  3. Heteroepitaxial growth of 3-5 semiconductor compounds by metal-organic chemical vapor deposition for device applications

    Science.gov (United States)

    Collis, Ward J.; Abul-Fadl, Ali

    1988-01-01

    The purpose of this research is to design, install and operate a metal-organic chemical vapor deposition system which is to be used for the epitaxial growth of 3-5 semiconductor binary compounds, and ternary and quaternary alloys. The long-term goal is to utilize this vapor phase deposition in conjunction with existing current controlled liquid phase epitaxy facilities to perform hybrid growth sequences for fabricating integrated optoelectronic devices.

  4. Unified explanation of chemical ordering, the Slater-Pauling rule, and half-metallicity in full Heusler compounds

    Science.gov (United States)

    Faleev, Sergey V.; Ferrante, Yari; Jeong, Jaewoo; Samant, Mahesh G.; Jones, Barbara; Parkin, Stuart S. P.

    2017-01-01

    In the present work we developed an orbital coupling model for cubic full Heusler compounds that provides a unified set of rules that account for the chemical ordering, magnetic moment, and composition of the most promising candidates for half-metallicity. The origin and limitations of the rules are clearly described. To the best of our knowledge all of the several dozen half-metallic Heusler compounds known in the literature that follow the Mt=Nt-24 or Mt=Nt-28 generalized Slater-Pauling behavior satisfy the derived half-metallicity rule. Calculations performed by using density functional theory—performed for 259 compounds—confirm the validity of our model and derived rules for broad classes of Heusler compounds.

  5. Tattoo pigments are cleaved by laser light-the chemical analysis in vitro provide evidence for hazardous compounds.

    Science.gov (United States)

    Vasold, Rudolf; Naarmann, Natascha; Ulrich, Heidi; Fischer, Daniela; König, Burkhard; Landthaler, Michael; Bäumler, Wolfgang

    2004-01-01

    In the western world, more than 80 million people decorate their skin with tattoos. Tattoo colorants are injected into the skin, like medical drugs. Most tattoo colorants are industrial pigments, and chemical industries have never produced them for human use but only to stain consumer goods. Up to 10% of tattooed people request removal of their tattoos because of an improved self-image or social stigmatization. In contrast to tattooing, physicians usually perform the tattoo removal. For that purpose laser light at very high intensities irradiates the skin to destroy the tattoo pigments. Based on a recent analysis of tattoo pigments, two widely used azo compounds were irradiated in suspension with laser and subsequently analyzed by using quantitative high-performance liquid chromatography and mass spectrometry. The high laser intensities cleaved the azo compounds, leading to an increase of decomposition products such as 2-methyl-5-nitroaniline, 2-5-dichloraniline and 4-nitro-toluene, which are toxic or even carcinogenic compounds. Moreover, the results of the chemical analysis show that the tattoo colorants already contain such compounds before laser irradiation. Because of a high number of patients undergoing laser treatment of tattoos and based on the results of our findings in vitro, it is an important goal to perform a risk assessment in humans regarding laser-induced decomposition products.

  6. A model explaining and predicting lamb flavour from the aroma-active chemical compounds released upon grilling light lamb loins.

    Science.gov (United States)

    Bueno, Mónica; Campo, M Mar; Cacho, Juan; Ferreira, Vicente; Escudero, Ana

    2014-12-01

    The objective of the work is to understand the role of the different aroma compounds in the perception of the local "lamb flavour" concept. For this, a set of 70 loins (Longissimus dorsi) from approximately seventy day-old Rasa Aragonesa male lambs were grilled and the aroma-active chemicals released during the grilling process were trapped and analyzed. Carbonyl compounds were derivatizated and determined by GC-NCI-MS, whereas other aromatic compounds were directly analyzed by GC-GC-MS. Odour activity values (OAVs) were calculated using their odour threshold values in air. Lamb flavour could be satisfactory explained by a partial least-squares model (74% explained variance in cross-validation) built by the OAVs of 32 aroma-active chemical compounds. The model demonstrates that the lamb flavour concept is the result of a complex balance. Its intensity critically and positively depends to the levels of volatile fatty acids and several dimethylpyrazines while is negatively influenced by the different alkenals and alkadienals. (E,E)-2,4-decadienal and (E)-2-nonenal showed top OAVs.

  7. Sulfonamides identified as plant immune-priming compounds in high-throughput chemical screening increase disease resistance in Arabidopsis thaliana

    Directory of Open Access Journals (Sweden)

    Yoshiteru eNoutoshi

    2012-10-01

    Full Text Available Plant activators are agrochemicals that protect crops from diseases by activating the plant immune system. To isolate lead compounds for use as practical plant activators, we screened 2 different chemical libraries composed of various bioactive substances by using an established screening procedure that can selectively identify immune-priming compounds. We identified and characterized a group of sulfonamide compounds—sulfameter, sulfamethoxypyridazine, sulfabenzamide, and sulfachloropyridazine—among the various isolated candidate molecules. These sulfonamide compounds enhanced the avirulent Pseudomonas-induced cell death of Arabidopsis suspension cell cultures and increased disease resistance in Arabidopsis plants against both avirulent and virulent strains of the bacterium. These compounds did not prevent the growth of pathogenic bacteria in minimal liquid media at 200 µM. They also did not induce the expression of defense-related genes in Arabidopsis seedlings, at least not at 24 and 48 h after treatment, suggesting that they do not act as salicylic acid analogs. In addition, although sulfonamides are known to be folate biosynthesis inhibitors, the application of folate did not restore the potentiation effects of the sulfonamides on pathogen-induced cell death. Our data suggest that sulfonamides potentiate Arabidopsis disease resistance by their novel chemical properties.

  8. Antirheumatoid Arthritis Activities and Chemical Compositions of Phenolic Compounds-Rich Fraction from Urtica atrichocaulis, an Endemic Plant to China

    Directory of Open Access Journals (Sweden)

    Mengyue Wang

    2012-01-01

    Full Text Available Urtica atrichocaulis, an endemic plant to China, is commonly used to treat rheumatoid arthritis even though its pharmaceutical activities and chemical constituents were not studied. Herein, we reported our investigations on the chemical compositions of the phenolic compounds-rich fraction from U. atrichocaulis (TFUA and their antirheumatoid arthritis activities. We found that the TFUA significantly inhibited the adjuvant-induced rats arthritis, carrageenin-induced rats paw edema, cotton pellet-induced mice granuloma, and the acetic acid-induced mice writhing response. Our phytochemical investigations on the TFUA resulted in the first-time isolation and identification of 17 phenolic constituents and a bis (5-formylfurfuryl ether. The extensive HPLC analysis also revealed the chemical compositions of TFUA. Our further biological evaluation of the main phenolic components, individually and collectively, indicated that the antirheumatoid arthritis activities of TFUA were the combined effect of multiple phenolic constituents.

  9. Chemical compounds and toxicological assessments of drinking water stored in polyethylene terephthalate (PET) bottles: A source of controversy reviewed.

    Science.gov (United States)

    Bach, Cristina; Dauchy, Xavier; Chagnon, Marie-Christine; Etienne, Serge

    2012-03-01

    A declaration of conformity according to European regulation No. 10/2011 is required to ensure the safety of plastic materials in contact with foodstuffs. This regulation established a positive list of substances that are authorized for use in plastic materials. Some compounds are subject to restrictions and/or specifications according to their toxicological data. Despite this, the analysis of PET reveals some non-intentionally added substances (NIAS) produced by authorized initial reactants and additives. Genotoxic and estrogenic activities in PET-bottled water have been reported. Chemical mixtures in bottled water have been suggested as the source of these toxicological effects. Furthermore, sample preparation techniques, such as solid-phase extraction (SPE), to extract estrogen-like compounds in bottled water are controversial. It has been suggested that inappropriate extraction methods and sample treatment may result in false-negative or positive responses when testing water extracts in bioassays. There is therefore a need to combine chemical analysis with bioassays to carry out hazard assessments. Formaldehyde, acetaldehyde and antimony are clearly related to migration from PET into water. However, several studies have shown other theoretically unexpected substances in bottled water. The origin of these compounds has not been clearly established (PET container, cap-sealing resins, background contamination, water processing steps, NIAS, recycled PET, etc.). Here, we surveyed toxicological studies on PET-bottled water and chemical compounds that may be present therein. Our literature review shows that contradictory results for PET-bottled water have been reported, and differences can be explained by the wide variety of analytical methods, bioassays and exposure conditions employed.

  10. [Pollution status of phenolic compounds in the soil and sediment from a chemical industrial park along the Yangtze River].

    Science.gov (United States)

    Chen, Jiexia; Wei, Enze; Xian, Qiming

    2014-08-01

    A determination method of 12 phenolic compounds in soil and sediment samples by gas chromatography-mass spectrometry (GC-MS) analysis coupled with accelerated solvent extraction (ASE) and gel permeation chromatography (GPC) for clean-up was developed. The method detection limits (MDLs) varied from 0. 410 μg/kg to 13. 1 μg/kg (dry weight), and the average recoveries ranged from 70. 7% to 122% with the relative standard deviations (RSDs) of 1. 2% to 16%. Based on this method, the levels of 12 phenolic compounds were investigated in 17 soil surrounding a chemical industrial park along the Yangtze River and seven sediment samples collected in the river. It was found that 11 of the 12 phenolic compounds were detected in all of the 24 samples, and only hydroquinone was below the MDL. The contents of the total 12 phenolic compounds were 10. 16-30. 66 mg/kg in the soil and 18. 00-29. 83 mg/kg in the sediment, with the average contents of 18. 26 and 22. 51 mg/kg respectively. It showed that 4-nitro- phenol, 4-chloro-3-methylphenol, 2-chlorohydroquinone, 2-methyl-4,6-dinitrophenol and 2,4,6- trichlorophenol were five major phenolic contaminants in the soil and sediment in this study. The pollution levels of the 12 phenolic compounds were low in the soil of the chemical industrial park as well as in the sediment of the Yangtze River, which implied a comparatively low risk for the environment.

  11. Identification of three classes of heteroaromatic compounds with activity against intracellular Trypanosoma cruzi by chemical library screening.

    Directory of Open Access Journals (Sweden)

    Esther Bettiol

    Full Text Available The development of new drugs against Chagas disease is a priority since the currently available medicines have toxic effects, partial efficacy and are targeted against the acute phase of disease. At present, there is no drug to treat the chronic stage. In this study, we have optimized a whole cell-based assay for high throughput screening of compounds that inhibit infection of mammalian cells by Trypanosoma cruzi trypomastigotes. A 2000-compound chemical library was screened using a recombinant T. cruzi (Tulahuen strain expressing beta-galactosidase. Three hits were selected for their high activity against T. cruzi and low toxicity to host cells in vitro: PCH1, NT1 and CX1 (IC(50: 54, 190 and 23 nM, respectively. Each of these three compounds presents a different mechanism of action on intracellular proliferation of T. cruzi amastigotes. CX1 shows strong trypanocidal activity, an essential characteristic for the development of drugs against the chronic stage of Chagas disease where parasites are found intracellular in a quiescent stage. NT1 has a trypanostatic effect, while PCH1 affects parasite division. The three compounds also show high activity against intracellular T. cruzi from the Y strain and against the related kinetoplastid species Leishmania major and L. amazonensis. Characterization of the anti-T. cruzi activity of molecules chemically related to the three library hits allowed the selection of two compounds with IC(50 values of 2 nM (PCH6 and CX2. These values are approximately 100 times lower than those of the medicines used in patients against T. cruzi. These results provide new candidate molecules for the development of treatments against Chagas disease and leishmaniasis.

  12. A Quantum Chemical and Statistical Study of Cytotoxic Activity of Compounds Isolated from Curcuma zedoaria

    Directory of Open Access Journals (Sweden)

    Omer Abdalla Ahmed Hamdi

    2015-04-01

    Full Text Available A series of 21 compounds isolated from Curcuma zedoaria was subjected to cytotoxicity test against MCF7; Ca Ski; PC3 and HT-29 cancer cell lines; and a normal HUVEC cell line. To rationalize the structure–activity relationships of the isolated compounds; a set of electronic; steric and hydrophobic descriptors were calculated using density functional theory (DFT method. Statistical analyses were carried out using simple and multiple linear regressions (SLR; MLR; principal component analysis (PCA; and hierarchical cluster analysis (HCA. SLR analyses showed that the cytotoxicity of the isolated compounds against a given cell line depend on certain descriptors; and the corresponding correlation coefficients (R2 vary from 0%–55%. MLR results revealed that the best models can be achieved with a limited number of specific descriptors applicable for compounds having a similar basic skeleton. Based on PCA; HCA and MLR analyses; active compounds were classified into subgroups; which was in agreement with the cell based cytotoxicity assay.

  13. Automated Microwave Double Resonance Spectroscopy: a Tool to Identify and Characterize Chemical Compounds

    Science.gov (United States)

    Martin-Drumel, Marie-Aline; McCarthy, Michael C.; Patterson, David; McGuire, Brett A.; Crabtree, Kyle N.

    2016-06-01

    Owing to its unparalleled structural specificity, rotational spectroscopy is a powerful technique to unambiguously identify and characterize volatile, polar molecules. We present here a new experimental approach, automated microwave double resonance (AMDOR) spectroscopy, to rapidly determine the rotational constants of these compounds without any a priori knowledge of elemental composition or molecular structure. This task is achieved by rapidly acquiring the classical (frequency vs. intensity) broadband spectrum of a molecule using chirped-pulse Fourier transform microwave (FTMW) spectroscopy, and subsequently analyzing it in near-real time using complementary cavity FTMW detection and double resonance. AMDOR measurements provide a unique ``barcode'' for each compound from which rotational constants can be extracted. To illustrate the power of this approach, AMDOR spectra of three aroma compounds --- trans-cinnamaldehyde, α- and β-ionone --- have been recorded and analyzed. The prospects to extend this approach to mixture characterization and purity assessment are described.

  14. Chemical behavior of organic compounds in the interface ofwater/dual-cation organobentonite

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The sorption behavior of polar or ionizable organiccompounds, such as p-nitrophenol, phenol and aniline, in thewater/organobentonite systems is investigated. Both adsorption andpartition occur to the sorption of organic compounds to dual-cationorganobentonites. The separate contributions of adsorption andpartition to the total sorption of organic compounds to dual-cationorganobentonites are analyzed mathematically in the first time. The factors to the contributions are also discussed. The results indicated that the contribution of adsorption and partition is related to the composition and ratio of dual-cation surfactants exchanging onto the bentonite. The sorption of organic compounds to dual-cation organobentonite is dominated by adsorption at low concentrations and by partition at high concentrations, making the organobentonites powerful sorbents for organic contaminants over wide range of concentrations.

  15. Combining Non Selective Gas Sensors on a Mobile Robot for Identification and Mapping of Multiple Chemical Compounds

    Directory of Open Access Journals (Sweden)

    Victor Hernandez Bennetts

    2014-09-01

    Full Text Available In this paper, we address the task of gas distribution modeling in scenarios where multiple heterogeneous compounds are present. Gas distribution modeling is particularly useful in emission monitoring applications where spatial representations of the gaseous patches can be used to identify emission hot spots. In realistic environments, the presence of multiple chemicals is expected and therefore, gas discrimination has to be incorporated in the modeling process. The approach presented in this work addresses the task of gas distribution modeling by combining different non selective gas sensors. Gas discrimination is addressed with an open sampling system, composed by an array of metal oxide sensors and a probabilistic algorithm tailored to uncontrolled environments. For each of the identified compounds, the mapping algorithm generates a calibrated gas distribution model using the classification uncertainty and the concentration readings acquired with a photo ionization detector. The meta parameters of the proposed modeling algorithm are automatically learned from the data. The approach was validated with a gas sensitive robot patrolling outdoor and indoor scenarios, where two different chemicals were released simultaneously. The experimental results show that the generated multi compound maps can be used to accurately predict the location of emitting gas sources.

  16. Combining non selective gas sensors on a mobile robot for identification and mapping of multiple chemical compounds.

    Science.gov (United States)

    Bennetts, Victor Hernandez; Schaffernicht, Erik; Pomareda, Victor; Lilienthal, Achim J; Marco, Santiago; Trincavelli, Marco

    2014-09-17

    In this paper, we address the task of gas distribution modeling in scenarios where multiple heterogeneous compounds are present. Gas distribution modeling is particularly useful in emission monitoring applications where spatial representations of the gaseous patches can be used to identify emission hot spots. In realistic environments, the presence of multiple chemicals is expected and therefore, gas discrimination has to be incorporated in the modeling process. The approach presented in this work addresses the task of gas distribution modeling by combining different non selective gas sensors. Gas discrimination is addressed with an open sampling system, composed by an array of metal oxide sensors and a probabilistic algorithm tailored to uncontrolled environments. For each of the identified compounds, the mapping algorithm generates a calibrated gas distribution model using the classification uncertainty and the concentration readings acquired with a photo ionization detector. The meta parameters of the proposed modeling algorithm are automatically learned from the data. The approach was validated with a gas sensitive robot patrolling outdoor and indoor scenarios, where two different chemicals were released simultaneously. The experimental results show that the generated multi compound maps can be used to accurately predict the location of emitting gas sources.

  17. Compound forming extractants, solvating solvents and inert solvents IUPAC chemical data series

    CERN Document Server

    Marcus, Y; Kertes, A S

    2013-01-01

    Equilibrium Constants of Liquid-Liquid Distribution Reactions, Part III: Compound Forming Extractants, Solvating Solvents, and Inert Solvents focuses on the compilation of equilibrium constants of various compounds, such as acids, ions, salts, and aqueous solutions. The manuscript presents tables that show the distribution reactions of carboxylic and sulfonic acid extractants and their dimerization and other reactions in the organic phase and extraction reactions of metal ions from aqueous solutions. The book also states that the inorganic anions in these solutions are irrelevant, since they d

  18. Chemical probes of quorum sensing: from compound development to biological discovery.

    Science.gov (United States)

    Welsh, Michael A; Blackwell, Helen E

    2016-09-01

    Bacteria can utilize chemical signals to coordinate the expression of group-beneficial behaviors in a method of cell-cell communication called quorum sensing (QS). The discovery that QS controls the production of virulence factors and biofilm formation in many common pathogens has driven an explosion of research aimed at both deepening our fundamental understanding of these regulatory networks and developing chemical agents that can attenuate QS signaling. The inherently chemical nature of QS makes studying these pathways with small molecule tools a complementary approach to traditional microbiology techniques. Indeed, chemical tools are beginning to yield new insights into QS regulation and provide novel strategies to inhibit QS. Here, we review the most recent advances in the development of chemical probes of QS systems in Gram-negative bacteria, with an emphasis on the opportunistic pathogen Pseudomonas aeruginosa We first describe reports of novel small molecule modulators of QS receptors and QS signal synthases. Next, in several case studies, we showcase how chemical tools have been deployed to reveal new knowledge of QS biology and outline lessons for how researchers might best target QS to combat bacterial virulence. To close, we detail the outstanding challenges in the field and suggest strategies to overcome these issues.

  19. Organic compounds as corrosion inhibitors for mild steel in acidic media: correlation between inhibition efficiency and chemical structure

    Energy Technology Data Exchange (ETDEWEB)

    Elias, Elizandra C.S.; Chrisman, Erika C.A.N. [Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, RJ (Brazil). Escola de Quimica

    2009-12-19

    The use of inhibitors for mild steels corrosion control which are in contact with aggressive environment is an accepted practice in acid treatment of oil-wells. Organic compounds have been studied to evaluate their corrosion inhibition potential. Film-forming corrosion inhibitors, commonly used to protect oil-field equipment, can be absorbed on the steel surface to give structurally ordered layers. Therefore, the electrons should act as an important role for this adsorption. Studies reveal that organic compounds show significant inhibition efficiency. For this purpose, their molecules should contain N, O and S heteroatoms in various functional groups, long hydrocarbon linear or branched radical and anion and cation active components. However, most of these compounds are not only expensive but also toxic to living beings. According to the 'Green Chemistry' rules, corrosion inhibitors based on organic compounds should be cheap, with low toxicity and have high inhibition efficiency. In this study, the effects of some organic compounds with different groups such as amide, ether, phenyldiamine, anime and aminophenol on the corrosion behavior of mild steel in acidic media have been investigated. The experimental data were obtained by gravimetric measurements. The results show that these compounds reveal a promising corrosion inhibition where phenyldiamine is the most efficient. The effect of molecular structure on the corrosion inhibition efficiency was investigated by semi-empirical quantum chemical calculations. The electronic properties such as highest occupied molecular orbital (HOMO), lowest unoccupied molecular orbital (LUMO) energy levels, and LUMO-HOMO energy gap orbital density were calculated. The relations between the inhibition efficiency and some quantum parameters are discussed and correlations are proposed. The highest values for the HOMO densities were found in the vicinity nitrogen atom, indicating that it is the most probable adsorption center

  20. Chemical characterisation of three haemolytic compounds from the microalgal species Fibrocapsa japonica (Raphidophyceae)

    NARCIS (Netherlands)

    Fu, M.; Koulman, A; van Rijssel, M; Lutzen, A.; de Boer, M.K.; Tyl, M.R.; Liebezeit, G.

    2004-01-01

    The molecular Structures of the three main haemolytic compounds (Fj1, Fj2 and Fj3) isolated from the ichthyotoxic microalgal species Fibrocapsa japonica have been investigated by NMR, LC-ESI-MS, ESI-MS-MS, IR, GC-MS and GC-HRMS methods. They are polyunsaturated fatty acids which we identified as: 6,

  1. ISOTOPIC (14C) AND CHEMICAL COMPOSITION OF ATMOSPHERIC VOLATILE ORGANIC COMPOUND FRACTIONS - PRECURSORS TO OZONE FORMATION

    Science.gov (United States)

    Atmospheric volatile organic compounds (VOCs) are an important factor in the production of ozone near ground level [3]. Many hydrocarbons originate from auto exhaust. However, a number of VOCs, e.g., isoprene, are known to be natural in origin. To develop reliable models for un...

  2. Chemical characterization of bioactive compounds from the endophytic fungus Diaporthe helianthi isolated from Luehea divaricata

    Directory of Open Access Journals (Sweden)

    Vânia Specian

    2012-09-01

    Full Text Available Endophytic microorganisms, defined as fungi or bacteria that colonize the interior of plants without causing any immediate negative effects or damages, have reciprocal relationships with host plants. In some cases their presence is beneficial to the host due to the synthesis of bioactive compounds, among which several alcohols, esters, ketones and others that may react with other compounds and may be lethal to pathogenic microorganisms. Diaporthe helianthi (Phomopsis helianthi in its anamorphic phase is available worldwide, especially in Europe, Asia and America. Isolated in Europe as an agent of the sunflower stem cancer, it has also been endophytically isolated from tropical and temperate plants. A D. helianthi strain isolated from Luehea divaricata has been employed in current research. An investigation of the secondary metabolite from D. helianthi by CC and NMR of ¹H and 13C yielded the separation of 10 fractions and the identification of the phenolic compound 2(-4 hydroxyphenyl-ethanol (Tyrosol. Its antimicrobial reaction was tested and the ensuing antagonistic effects on the human pathogenic bacteria Enterococcus hirae, Escherichia coli, Micrococcus luteus, Salmonella typhi, Staphylococcus aureus, phytopathogenic Xanthomonas asc. phaseoli and phytopathogenic fungi were demonstrated. Results show that bioactive compounds and Tyrosol produced by D. helianthi have a biotechnological potential.

  3. Digestibility, chemical compound and protein quality of amaranthus forage at two harvested cut

    Directory of Open Access Journals (Sweden)

    pooria ehsani

    2016-04-01

    technique for the in vitro digestion of forage crops (32. In a completely randomized experiment with factorial arrangement (2×2 the digestibility, chemical compound and protein quality of two varieties of amaranthus including: Kharkof (K, A. Spp.(S. which were planted as forage crops and harvested at two cuts, were studied. Data were subjected to analysis using the GLM procedure of SAS (26, using the statistical model: Yijk = µ + Vi + Dj + Vi Dj + eijk Results and Discussion Results of in vitro two stage digestibility (IVD for DM, OM and DOMD were 60.19, 58.16 and 49.09, respectively which were significantly (p>0.05 affected by cultivars and interaction between cultivars and cuts. Results indicated that the means of CP, ASH, NDF, ADF,ADL, NDIN, ADIN, Ca, P, Mg, and K were 14.72, 15.44, 40.85, 27.90,5.07,21.76,6.60, 1.55, 0.25, 0.28, 1.48, percent; respectively. Plant maturity was found to affect neutral detergent fiber (NDF, acid detergent fiber (ADF, lignin, CP and nitrate content of amaranth forage. Amaranth contains a high ash content due to its C4 metabolism and a very high carbon uptake per unit area (29. This high ash is in agreement with other researchers (1, 21 .Our amaranth accession had higher NDF (27 and lower ADF (22, 23 in comparison to A. Hypochondriacus reported by other researchers. Lignin content in amaranth is less than that reported by other researchers (27. With increased plant maturity, fraction B1 decreased, probably due to an increase in cell wall bound N (16. Researchers observed that Similar results in CP fraction of amaranthus hypochoderyacus (21(. We observed that a negative relationship between NDF and fraction B1. There was a tendency for fraction B2 to increase with advancing maturity, similar to other researchers (21. At the second harvest, fraction B3 was higher than that at first harvest, similar to reserchers with amaranthus hypochondriacus (1. Different changes in NDF concentration of plant parts with maturity may explain the

  4. Production of Monomeric Aromatic Compounds from Oil Palm Empty Fruit Bunch Fiber Lignin by Chemical and Enzymatic Methods.

    Science.gov (United States)

    Tang, Pei-Ling; Hassan, Osman; Maskat, Mohamad Yusof; Badri, Khairiah

    2015-01-01

    In this study, oil palm empty fruit bunch (OPEFBF) was pretreated with alkali, and lignin was extracted for further degradation into lower molecular weight phenolic compounds using enzymes and chemical means. Efficiency of monomeric aromatic compounds production from OPEFBF lignin via chemical (nitrobenzene versus oxygen) and enzymatic [cutinase versus manganese peroxidase (MnP)] approaches was investigated. The effects of sodium hydroxide concentration (2, 5, and 10% wt.) and reaction time (30, 90, and 180 minutes) on the yield of aromatic compounds were studied. The results obtained indicated that nitrobenzene oxidation produced the highest yield (333.17 ± 49.44 ppm hydroxybenzoic acid, 5.67 ± 0.25 ppm p-hydroxybenzaldehyde, 25.57 ± 1.64 ppm vanillic acid, 168.68 ± 23.23 ppm vanillin, 75.44 ± 6.71 ppm syringic acid, 815.26 ± 41.77 ppm syringaldehyde, 15.21 ± 2.19 ppm p-coumaric acid, and 44.75 ± 3.40 ppm ferulic acid), among the tested methods. High sodium hydroxide concentration (10% wt.) was needed to promote efficient nitrobenzene oxidation. However, less severe oxidation condition was preferred to preserve the hydroxycinnamic acids (p-coumaric acid and ferulic acid). Cutinase-catalyzed hydrolysis was found to be more efficient than MnP-catalyzed oxidation in the production of aromatic compounds. By hydrolyzed 8% wt. of lignin with 0.625 mL cutinase g(-1) lignin at pH 8 and 55°C for 24 hours, about 642.83 ± 14.45 ppm hydroxybenzoic acid, 70.19 ± 3.31 ppm syringaldehyde, 22.80 ± 1.04 ppm vanillin, 27.06 ± 1.20 ppm p-coumaric acid, and 50.19 ± 2.23 ppm ferulic acid were produced.

  5. Development of a general model for determination of thermal conductivity of liquid chemical compounds at atmospheric pressure

    DEFF Research Database (Denmark)

    Gharagheizi, Farhad; Ilani‐Kashkouli, Poorandokht; Sattari, Mehdi

    2013-01-01

    In this communication, a general model for representation/presentation of the liquid thermal conductivity of chemical compounds (mostly organic) at 1 atm pressure for temperatures below normal boiling point and at saturation pressure for temperatures above the normal boiling point is developed...... of the model comprise temperature, acentric factor, critical pressure, normal boiling temperature, and molecular weight. Nearly 80% of the data set (15,221 data) is randomly assigned to develop the model equation, 10% of the data set (1902 data) is used to validate the model, and the remaining data (1902 data...

  6. Methodologies for chemical utilization of C02 to valuable compounds through molecular activation by efficient catalysts

    Institute of Scientific and Technical Information of China (English)

    Liangnian HE; Ya DU; Chengxia MIAO; Jinquan WANG; Xiaoyong DOU; Ying WU

    2009-01-01

    The reactions of CO2 with oxirane to produce cyclic carbonate, and with aziridine to afford oxazolidine have been of interest as a useful method for its fixation by a chemical process. Highly efficient processes employing recyclable CO2-phlilic homogeneous catalyst were devised for environmentally benign synthesis of cyclic carbonates and oxazolidinones under supercritical CO2 without any organic solvent. These processes represent pathways for greener chemical fixations of CO2 to afford industrial useful materials such as organic carbonates and oxazolidinones with great potential applications.

  7. Chemical shift of U L3 edges in different uranium compounds obtained by X-ray absorption spectroscopy with synchrotron radiation

    Indian Academy of Sciences (India)

    D Joseph; C Nayak; P Venu Babu; S N Jha; D Bhattacharyya

    2014-05-01

    Uranium L3 X-ray absorption edge was measured in various compounds containing uranium in U4+, U5+ and U6+ oxidation states. The measurements have been carried out at the Energy Dispersive EXAFS beamline (BL-08) at INDUS-2 synchrotron radiation source at RRCAT, Indore. Energy shifts of ∼ 2–3 eV were observed for U L3 edge in the U-compounds compared to their value in elemental U. The different chemical shifts observed for the compounds having the same oxidation state of the cation but different anions or ligands show the effect of different chemical environments surrounding the cations in determining their X-ray absorption edges in the above compounds. The above chemical effect has been quantitatively described by determining the effective charges on U cation in the above compounds.

  8. Ab-initio investigation of the influence of chemical compounds on graphene layer properties in fabricated IR detector

    Science.gov (United States)

    Ruta, L.; Wozny, J.; Szczecinska, N.; Lisik, Z.

    2016-11-01

    In this work, the influence of H2O, NaOH and propanol on properties of graphene layer placed on SiO2 has been investigated. These chemical particles are present during technological steps required for a device fabrication and may lead to significant changes of graphene properties. The investigation has been done by means of ab-initio simulation based on the DFT method. A MedeA-VASP package was used to investigate behavior of graphene layer in the vicinity of chemical compounds. Presented studies show that properties of graphene are significantly modified when particles of H2O and NaOH are captured in-between graphene layer and SiO2. Special attention should be paid to NaOH which, according to simulations, decays and modifies the properties of graphene layer.

  9. Characterizing the Chemical Complexity of Semi-Volatile Organic Compounds from Biomass Burning in Amazonia

    Science.gov (United States)

    Wernis, R. A.; Yee, L.; Isaacman-VanWertz, G. A.; Kreisberg, N. M.; de Sá, S. S.; Liu, Y.; Martin, S. T.; Alexander, L.; Palm, B. B.; Hu, W.; Campuzano Jost, P.; Day, D. A.; Jimenez, J. L.; Artaxo, P.; Viegas, J.; Manzi, A. O.; Souza, R. A. F. D.; Hering, S. V.; Goldstein, A. H.

    2015-12-01

    Aerosols are a source of great uncertainty in radiative forcing predictions and have poorly understood impacts on human health. In many environments, biomass burning contributes a significant source of primary aerosol as well as reactive gas-phase precursors that can form secondary organic aerosol (SOA). One class of these precursors, semi-volatile organic compounds (SVOCs), has been shown to have a large contribution to the amount of SOA formed from fire emissions. At present, SVOC emissions from biomass burning are poorly constrained and understanding their contributions to SOA formation is an important research challenge. In the Amazonian dry season, biomass burning is a major source of gases and aerosols reducing regional air quality. As part of the GoAmazon 2014/5 field campaign, we deployed the Semi-Volatile Thermal desorption Aerosol Gas Chromatograph (SV-TAG) instrument at the rural T3 site, 60 km to the west of Manaus, Brazil to measure hourly concentrations of SVOCs in the gas and particle phases. This comprehensive technique detects thousands of compounds, enabling the discovery of previously unidentified compounds. In this work we explore compounds for which a correlation with well-known biomass burning tracers is observed to discover the identities of new tracers. We discuss contributions to the total organic aerosol from well-known, rarely reported and newly-identified biomass burning tracers. We find that levoglucosan, perhaps the most commonly used particle phase biomass burning tracer, contributed 0.6% and 0.3% of total organic aerosol in the dry and wet seasons, respectively.

  10. Identification of Some AOX Compounds Formed in Wool Chlorination Using Model Chemicals

    Institute of Scientific and Technical Information of China (English)

    WANG Jing; HE Jin-xin; DAJ Jin-jin

    2002-01-01

    The AOX (adsorbable organic halogens) problem in wool shrinkproofing effluents has attracted more attention in recent years. The probable origins and structures of AOX compounds were proved by the reaction of DCCA with the model substances of different amino acid residues.The GC-MS results indicated that available chlorine could chlorinate the side chain of tyrosine, histidine and trypotophan and generate AOX load in the effluent.

  11. Stimulation of Ideas through Compound-Based Bibliometrics: Counting and Mapping Chemical Compounds for Analyzing Research Topics in Chemistry, Physics, and Materials Science.

    Science.gov (United States)

    Barth, Andreas; Marx, Werner

    2012-12-01

    Counting compounds (rather than papers or citations) offers a new perspective for quantitative analyses of research activities. First of all, we can precisely define (compound-related) research topics and access the corresponding publications (scientific papers as well as patents) as a measure of research activity. We can also establish the time evolution of the publications dealing with specific compounds or compound classes. Moreover, the mapping of compounds by establishing compound-based landscapes has some potential to visualize the compound basis of research topics for further research activities. We have analyzed the rare earth compounds to give an example of a broad compound class. We present the number of the currently existing compounds and of the corresponding publications as well as the time evolution of the papers and patents. Furthermore, we have analyzed the rare earth cuprates (copper oxides) as an example of a narrower compound class to demonstrate the potential of mapping compounds by compound-based landscapes. We have quantified the various element combinations of the existing compounds and revealed all element combinations not yet realized in the synthesis within this compound class. Finally, we have analyzed the quasicrystal compound category as an example of a compound class that is not defined by a specific element combination or a molecular structure.

  12. Chemical characterization and mutagenic properties of polycyclic aromatic compounds in sediment from tributaries of the Great Lakes

    Science.gov (United States)

    Fabacher, David L.; Schmitt, Christopher J.; Besser, John M.; Mac, Michael J.

    1988-01-01

    Sediments from four inshore industrial sites and a reference site in the Great Lakes were extracted with solvents and characterized chemically for polycyclic aromatic compounds (PACs). An aqueous phase and a crude organic extract were obtained. The crude organic extract was further resolved into fractions A-2 (polycyclic aromatic hydrocarbons) and A-3 (nitrogen-containing polycyclic aromatic compounds), which were analyzed for PACs by gas chromatography and gas chromatography-mass spectrometry. The extracts and fractions were tested for mutagenicity in three assays: Ames, rat hepatocyte unscheduled DNA synthesis, and Chinese hamster ovary hypoxanthine-guanine phosphoribosyl transferase (CHO/HGPRT). Sediments from the industrial sites contained 27 to 363 μg/g total PACs; the reference site, less than 1 μg/g. Qualitative differences in the residue profiles among the sites were attributable to the probable sources of the PACs (petroleum versus combustion). Only one industrial site yielded measurable (0.1 μg/g or more) concentrations of individual nitrogen-containing PACs. In the Ames assay, only the highest doses of the A-2 fractions from two sites approached positive results. Conversely, the crude organic extract and A-2 and A-3 fractions from all sites induced unscheduled DNA synthesis. Crude organic extracts and the A-2 and A-3 fractions from all industrial sites gave well-defined dose-response relations in the CHO/HGPRT assay. We established the presence of chemical mutagens in sediment that could be correlated with neoplasms in fish from many of the sites; however, the mutagenicity of the sediment extracts was not completely related to the degree of contamination by PACs. We also discuss the utility of mutagenicity assays in the evaluation of complex chemical mixtures and recommend the use of a CHO/HGPRT-type assay in which cells are not required to proliferate in the presence of potential interfering chemicals.

  13. Development of a QSAR for worst case estimates of acute toxicity of chemically reactive compounds

    NARCIS (Netherlands)

    Freidig, A.P.; Dekkers, S.; Verwei, M.; Zvinavashe, E.; Bessems, J.G.M.; Sandt, J.J.M. van de

    2007-01-01

    Future EU legislations enforce a fast hazard and risk assessment of thousands of existing chemicals. If conducted by means of present data requirements, this assessment will use a huge number of test animals and will be neither cost nor time effective. The purpose of the current research was to deve

  14. A Gold Coordination Compound as a Chemical Probe to Unravel Aquaporin-7 Function

    NARCIS (Netherlands)

    Madeira, Ana; de Almeida, Andreia; de Graaf, Chris; Camps, Marta; Zorzano, Antonio; Moura, Teresa F; Casini, Angela; Soveral, Graça

    2014-01-01

    Aquaporins (AQPs) are membrane water/glycerol channels that are involved in many physiological functions. Aquaporin-based modulators are predicted to have potential utility in the treatment of several diseases, as well as chemical tools to assess AQPs function in biological systems. We recently repo

  15. Antimalarial efficacy of dynamic compound of plumbagin chemical constituent from Plumbago zeylanica Linn (Plumbaginaceae) against the malarial vector Anopheles stephensi Liston (Diptera: Culicidae).

    Science.gov (United States)

    Pradeepa, Venkatraman; Sathish-Narayanan, Subbiah; Kirubakaran, Suyambulingam Arunachalam; Senthil-Nathan, Sengottayan

    2014-08-01

    In the present investigation, the effective root compound of plumbagin of Plumbago zeylanica (Plumbaginaceae) was evaluated for chemical constituent and antimalarial effect against the fourth instar larvae of Anopheles stephensi Liston (Diptera). In the chromatographic analyses of root compound with Rf value of 0.788 and NMR analyses also revealed that the effective compound contain naphthoquinone plumbagin were identified as the major chemical constituent. Larval mortality was observed after 3 h of exposure period. The plumbagin compound showed remarkable larvicidal activity against A. stephensi (LC50 32.65 and LC9072.27 ppm). Histopathological effects of compound was observed in the treated larvae. Based on the results, the plumbagin compound of P. zeylanica can be considered as a new source of natural larvicide for the control of malarial vector.

  16. A chemical compound that stimulates the human homologous recombination protein RAD51

    OpenAIRE

    Jayathilaka, Krishanthi; Sheridan, Sean D.; Bold, Tyler D.; Bochenska, Katarzyna; Logan, Hillary L.; Weichselbaum, Ralph. R.; Bishop, Douglas K.; Connell, Philip P.

    2008-01-01

    RAD51 and other members of the RecA family of strand exchange proteins assemble on ssDNA to form presynaptic filaments, which carry out the central steps of homologous recombination. A microplate-based assay was developed for high-throughput measurement of hRAD51 filament formation on ssDNA. With this method, a 10,000 compound library was screened, leading to the identification of a small molecule (RS-1) that enhances hRAD51 binding in a wide range of biochemical conditions. Salt titration ex...

  17. Evaluation of some microbial agents, natural and chemical compounds for controlling tomato leaf miner, Tuta absoluta (Meyrick (Lepidoptera: Gelechiidae

    Directory of Open Access Journals (Sweden)

    Abd El-Ghany Nesreen M.

    2016-12-01

    Full Text Available Solanaceous plants have a great economic impact in Egypt. These groups of plants include potatoes, tomatoes and eggplants. The new invasive pest of tomatoes, Tuta absoluta (Meyrick causes the greatest crop losses which can range from 60 to 100%. After its detection in Egypt during the last half of 2009, it spread quickly to all provinces in the country. We aiming to propose a sustainable control program for this devastating pest. In this research we tested three groups of control agents. The first was microbial and natural, the second - plant extracts and the third - chemical insecticides. Our results showed that the impact of T. absoluta can be greatly reduced by the use of sustainable control measures represented by different insecticide groups. Bioassay experiments showed that this devastating pest can be controlled with some compounds that give high mortality rates. Of these compounds, spinosad and Beauveria bassiana, microbial control agents, followed by azadirachtin, gave the best results in controlling T. absoluta. Of the chemical insecticides, lambda-cyhalotrin was the most effective, followed by lufenuron and profenofos. In conclusion we encourage farmers to use microbial and natural control measures in combating the tomato leafminer, T. absoluta, in Integrated Pest Mangement (IPM programs.

  18. Monitoring the Evolution of Major Chemical Compound in Dairy Products During Shelf-Life by FTIR

    OpenAIRE

    Adriana Păucean; Dan Vodnar; Carmen Socaciu; Simona Man

    2014-01-01

    Fourier-transform infrared (FTIR) spectroscopy is considered to be a comprehensive and sensitive method to characterize the chemical composition and for detection of molecular changes in different samples. In this study, FTIRspectroscopy  was employed as an rapid and low-cost technique in order to characterize the FTIR spectra and identify appropriate spectral regions for dairy product fermented by a lactic culture consisting by species of Lactococcus lactis and Leuconostoc mesenteroides. A s...

  19. [Experience in the use of chemical compounds for the primary identification and differentiation of enteroviruses].

    Science.gov (United States)

    Amvros'eva, T V; Votiakov, V I; Andreeva, O T; Kazinets, O N; Bogush, Z F; Sharko, R M; Kvacheva, Z B

    2003-02-01

    Data on the usage of chemical inhibitors nifan and belvtazid, which possess a selective and antienteroviral effect, in the primary identification of enteroviruses and their differentiation into polio- and non-poliomyelytic ones isolated from human clinical materials or the environment by using the cell culture are presented in the article. The method is recommended for the practical use by the virology service in the diagnostics of enteroviral infections and in the identification of cytopathic agents isolated from the enviroment.

  20. STUDY REGARDING THE CORELATION BETWEEN SOMATIC CELLS COUNT AND MAJOR CHEMICAL COMPOUNDS IN RAW MILK

    Directory of Open Access Journals (Sweden)

    S. ACATINCĂI

    2013-12-01

    Full Text Available This study approaches the dynamic of somatic cells number and chemical composition of milk during 13 months of control. The study also investigates the correlations between the number of somatic cells and some chemical parameters in milk. Studies were carried out on Romanian Black and White cows between March 2005 and March 2006 at the Didactical farm of the Banat University of Agricultural Sciences Timisoara. As quality indicator, the number of somatic cells has different values among the controls. Average values for the 13 months of control, with the exception of three controls, were below maximum limit admitted from 1th of January 2007 (600000 SCC/ml milk. There weren’t any significant differences for SCC between the two seasons. Chemical parameters in milk varied in close limits and the differences were not significant, with one exception for fat percent. Fat percent is higher (p<0.05 in the cold season 3.87% compared with 3.55% during the warm season. Somatic cells number is weak correlated with lactose and strong correlated with proteins.

  1. Chemical effect on the K shell absorption parameters of some selected cerium compounds

    Science.gov (United States)

    Akman, F.; Kaçal, M. R.; Durak, R.

    2016-08-01

    In this study, the photoelectric cross section values of Ce, CeCl3.7H2O, Ce2(SO4)3, Ce(OH)4 and Ce2O3 samples were measured in the energy range from 31.82 keV up to 51.70 keV by adopting in narrow beam geometry. Using these photoelectric cross sections, the K shell photoelectric cross sections at the K-edge, the K shell absorption jump ratios and jump factors, the Davisson-Kirchner ratios and K shell oscillator strength values were estimated experimentally. The measured parameters were compared with the theoretical calculated values. It is observed that the K shell photoelectric cross section at the K-edge and K shell oscillator strength values of an element are affected by the chemical environment of material while the K shell absorption jump ratio, K shell absorption jump factor and Davisson-Kirchner ratio are not affected by the chemical environment of material for the present samples. To the best of our knowledge, the chemical effects on the Davisson-Kirchner ratio and K shell oscillator strength have not been discussed for any element by now.

  2. Leaf surface lipophilic compounds as one of the factors of silver birch chemical defense against larvae of gypsy moth.

    Directory of Open Access Journals (Sweden)

    Vyacheslav V Martemyanov

    Full Text Available Plant chemical defense against herbivores is a complex process which involves a number of secondary compounds. It is known that the concentration of leaf surface lipophilic compounds (SLCs, particularly those of flavonoid aglycones are increased with the defoliation treatment of silver birch Betula pendula. In this study we investigated how the alteration of SLCs concentration in the food affects the fitness and innate immunity of the gypsy moth Lymantria dispar. We found that a low SLCs concentrations in consumed leaves led to a rapid larval development and increased females' pupae weight (= fecundity compared to larvae fed with leaves with high SLCs content. Inversely, increasing the compounds concentration in an artificial diet produced the reverse effects: decreases in both larval weight and larval survival. Low SLCs concentrations in tree leaves differently affected larval innate immunity parameters. For both sexes, total hemocytes count in the hemolymph increased, while the activity of plasma phenoloxidase decreased when larvae consume leaves with reduced content of SLCs. Our results clearly demonstrate that the concentration of SLCs in silver birch leaves affects not only gypsy moth fitness but also their innate immune status which might alter the potential resistance of insects against infections and/or parasitoids.

  3. A review on botanical species and chemical compounds with appetite suppressing properties for body weight control.

    Science.gov (United States)

    Astell, Katie J; Mathai, Michael L; Su, Xiao Q

    2013-09-01

    As obesity has reached epidemic proportions, the management of this global disease is of clinical importance. The availability and popularity of natural dietary supplements for the treatment of obesity has risen dramatically in recent years. The purpose of this paper was to review the effect of commonly available over the counter plant-derived supplements used to suppress appetite for obesity control and management. The data were obtained from the electronic databases PubMed, SpringerLink, Google Scholar, ScienceDirect, and MEDLINE with full text (via EBSCOHost) and the databases were accessed during late 2012 - early January 2013. The botanical species discussed in this review include Camellia sinensis, Caralluma fimbriata, Citrus aurantium, Coleus forskohlii, Garcinia cambogia and Phaseolus vulgaris. This review found that many botanical species including crude extracts and isolated compounds from plants have been shown to provide potentially promising therapeutic effects including appetite control and weight loss. However, many of these crude extracts and compounds need to be further investigated to define the magnitude of the effects, optimal dosage, mechanisms of action, long term safety, and potential side effects.

  4. Suppressive effect of herbal compound 861 on chemical hepatocarcinogenesis in rats

    Institute of Scientific and Technical Information of China (English)

    崔儒涛; 王宝恩; 张福奎; 陈光勇; 尹珊珊

    2003-01-01

    Objective To investigate the effects of herbal compound 861 (Cpd861) on hepatocarcinogenesis induced by diethylntrosamine and 2-acetylaminofluorene (DEN-AAF) in female Sprague Dawley rats.Methods Liver preneoplastic foci were induced using the DEN-AAF method in female Sprague Dawley rats, which were then treated with Cpd861. For quantitative assessment of liver preneoplastic foci, the placental form of glutathione-S-transferase (GST-P) positive foci were measured using immunohistochemical staining and image analysis. GST-P protein expression was measured by Western blotting, mRNA expression was assessed by Northern blotting.Results Treatment using DEN-AAF caused a significant decrease in body weight and increase in liver weight compared to the control group. Oral Cpd861 administration essentially prevented DEN-AAF-induced body weight loss and liver weight increase. When 2-AAF was followed by treatment with Cpd861, there was a decrease in the number of large foci as compared to 2-AAF alone. However, there were still considerable numbers of small mixed clear/vacuolated cell foci, some of which were positive for GST-P. Significant increase in GST-P protein and mRNA expression were observed in the DEN-AAF group, while treatment with Cpd861 inhibited the increase. The effect of Cpd861 on hepatocarcinogenesis occurred in a concentration-dependent manner. Conclusion Chinese herbal compound Cpd861 prevents hepatocarcinogenesis in DEN-AAF-induced liver preneoplastic lesions in rats.

  5. Studies on chemical modification of papain by 5-chlorosulfonyl-2-oxobenzimidazole as biotin model compound

    OpenAIRE

    石橋, 文秀; 森藤, 昌樹; 根来, 千晴; 園田, 章; 片山, あずさ; 武部, 靖

    2009-01-01

     5-chlorosulfonyl-2-oxobenzimidazole(1) was synthesized.  On adding 1 to the suspension of papain in acetonitrile containing formamide, 1 was introduced into the papain in a yield of 7%, suggesting that 1 modified papain chemically to give 2-oxobenzimidazolesulfonyl papain(OBI- papain).  Also, it was found in-terestingly that papain activity of OBI-papain was maintained and that SH group in the active center in the large cleft of papain was free.  Accordingly, It expects that OBI-papain might...

  6. Optimization and application of atmospheric pressure chemical and photoionization hydrogen-deuterium exchange mass spectrometry for speciation of oxygen-containing compounds.

    Science.gov (United States)

    Acter, Thamina; Kim, Donghwi; Ahmed, Arif; Jin, Jang Mi; Yim, Un Hyuk; Shim, Won Joon; Kim, Young Hwan; Kim, Sunghwan

    2016-05-01

    This paper presents a detailed investigation of the feasibility of optimized positive and negative atmospheric pressure chemical ionization (APCI) mass spectrometry (MS) and atmospheric pressure photoionization (APPI) MS coupled to hydrogen-deuterium exchange (HDX) for structural assignment of diverse oxygen-containing compounds. The important parameters for optimization of HDX MS were characterized. The optimized techniques employed in the positive and negative modes showed satisfactory HDX product ions for the model compounds when dichloromethane and toluene were employed as a co-solvent in APCI- and APPI-HDX, respectively. The evaluation of the mass spectra obtained from 38 oxygen-containing compounds demonstrated that the extent of the HDX of the ions was structure-dependent. The combination of information provided by different ionization techniques could be used for better speciation of oxygen-containing compounds. For example, (+) APPI-HDX is sensitive to compounds with alcohol, ketone, or aldehyde substituents, while (-) APPI-HDX is sensitive to compounds with carboxylic functional groups. In addition, the compounds with alcohol can be distinguished from other compounds by the presence of exchanged peaks. The combined information was applied to study chemical compositions of degraded oils. The HDX pattern, double bond equivalent (DBE) distribution, and previously reported oxidation products were combined to predict structures of the compounds produced from oxidation of oil. Overall, this study shows that APCI- and APPI-HDX MS are useful experimental techniques that can be applied for the structural analysis of oxygen-containing compounds.

  7. Chemical compounds effective against the citrus Huanglongbing bacterium 'Candidatus Liberibacter asiaticus' in planta.

    Science.gov (United States)

    Zhang, Muqing; Powell, Charles A; Zhou, Lijuan; He, Zhenli; Stover, Ed; Duan, Yongping

    2011-09-01

    Citrus Huanglongbing (HLB) is one of the most destructive diseases of citrus worldwide and is threatening the survival of the Floridian citrus industry. Currently, there is no established cure for this century-old and emerging disease. As a possible control strategy for citrus HLB, therapeutic compounds were screened using a propagation test system with 'Candidatus Liberibacter asiaticus'-infected periwinkle and citrus plants. The results demonstrated that the combination of penicillin and streptomycin (PS) was effective in eliminating or suppressing the 'Ca. L. asiaticus' bacterium and provided a therapeutically effective level of control for a much longer period of time than when administering either antibiotic separately. When treated with the PS, 'Ca. L. asiaticus'-infected periwinkle cuttings achieved 70% of regeneration rates versus citrus plants. This may provide a useful tool for the management of citrus HLB and other Liberibacter-associated diseases.

  8. Self-assembled host monolayer based chemical microsensors for volatile organic compounds

    Energy Technology Data Exchange (ETDEWEB)

    Shi, Jing-Xuan; Moore, L.W.; Springer, K.N. [Los Alamos National Lab., NM (United States)] [and others

    1995-12-01

    The interaction of organic vapors with self-assembled host monolayers on the surface of 200 MHz surface acoustic wave (SAW) resonators is studied as a method of tracking toxins in the gas phase. Molecular self-assembly techniques were employed to achieve covalent surface-attachment of two families of {open_quotes}bucket{close_quotes} molecules - cyclodextrins and calix[n]arenes - to native oxides on Si<100> and single-crystal ST-cut quartz. The formation of the covalently-bound functionalized bucket monolayers on oxide surfaces was characterized by polarized, variable-angle, internal attenuated total reflection infrared spectroscopy and surface acoustic mass transduction. SAW based sensors were capable of detecting volatile organic compounds (VOCs) down to ppb levels. Pattern recognition with an array of complementary microsensors appears to be a viable approach for identifying and quantifying a particular VOC.

  9. Chemical-meteorological aspects of some atmospheric nitrogen compounds in the tropics (CUBA)

    Energy Technology Data Exchange (ETDEWEB)

    Cuesta Santos, O.A.; Ortiz Bulto, P.L.; Hurtado, M.S.; Gonzalez, M.L. [Meteorological Institute of Cuban Ministry of Science, Havana City (Cuba)

    1996-12-31

    The transboundary problems of global and regional atmospheric pollution are at current time, a concern of scientific community and environmentalist, so our region is not considered as an exception on this matter. In our monitoring stations, some studies confirming the presence of nitrogen compounds connected with long range transport have been undertaken. For such reason, the interesting tropospheric chemistry reactions shall be verified. The above mentioned studies include the analysis of NO{sub x} (NO + NO{sub 2}), NH{sub 3}, nitrate and ammonium concentrations in aerosols and rainfall in some monitoring stations its connection with the Kinds of Synoptic Situations (KSS) and the research on back tracks, so all this allows to know its possible sources of origin. As a result of interest it has been found that the total deposition of these compounds oscillates between 0,706 an d3,317 g.m{sup -2} year{sup -1}. The wet deposition exhibits approximately 60%, while the dry one is of 40%. The weight of both depositions depends on our tropical rainy climate`s features. On the other hand, the oxidized nitrogen forms only give 40%, while the reduced ones 60% of total. This coincides more with the power of natural sources in accordance with our climate. The nitrate`s concentrations in aerosols and rainfall connected with Continental Migratory Anticyclone have the higher values than with remaining kinds of synoptic situations influencing on our territory, so it can be concluded that there is transport of these pollutants from continent.

  10. A chemical compound that stimulates the human homologous recombination protein RAD51.

    Science.gov (United States)

    Jayathilaka, Krishanthi; Sheridan, Sean D; Bold, Tyler D; Bochenska, Katarzyna; Logan, Hillary L; Weichselbaum, Ralph R; Bishop, Douglas K; Connell, Philip P

    2008-10-14

    RAD51 and other members of the RecA family of strand exchange proteins assemble on ssDNA to form presynaptic filaments, which carry out the central steps of homologous recombination. A microplate-based assay was developed for high-throughput measurement of hRAD51 filament formation on ssDNA. With this method, a 10,000 compound library was screened, leading to the identification of a small molecule (RS-1) that enhances hRAD51 binding in a wide range of biochemical conditions. Salt titration experiments showed that RS-1 can enhance filament stability. Ultrastructural analysis of filaments formed on ssDNA showed that RS-1 can increase both protein-DNA complex lengths and the pitch of helical filament turns. RS-1 stimulated hRAD51-mediated homologous strand assimilation (D-loop) activity by at least 5- to 11-fold, depending on the condition. This D-loop stimulation occurred even in the presence of Ca(2+) or adenylyl-imidodiphosphate, indicating that the mechanism of stimulation was distinct from that conferred by Ca(2+) and/or inhibition of ATPase. No D-loop activity was observed in the absence of a nucleotide triphosphate cofactor, indicating that the compound does not substitute for this requirement. These results indicate that RS-1 enhances the homologous recombination activity of hRAD51 by promoting the formation of active presynaptic filaments. Cell survival assays in normal neonatal human dermal fibroblasts demonstrated that RS-1 promotes a dose-dependent resistance to the cross-linking chemotherapeutic drug cisplatin. Given that RAD51-dependent recombination is a major determinant of cisplatin resistance, RS-1 seems to function in vivo to stimulate homologous recombination repair proficiency. RS-1 has many potential applications in both research and medical settings.

  11. Chemical Identity Crisis: Glass and Glassblowing in the Identification of Organic Compounds.

    Science.gov (United States)

    Jackson, Catherine M

    2015-04-01

    This essay explains why and how nineteenth-century chemists sought to stabilize the melting and boiling points of organic substances as reliable characteristics of identity and purity and how, by the end of the century, they established these values as 'Constants of Nature'. Melting and boiling points as characteristic values emerge from this study as products of laboratory standardization, developed by chemists in their struggle to classify, understand and control organic nature. A major argument here concerns the role played by the introduction of organic synthesis in driving these changes. Synthetic organic chemistry vastly increased the number of known organic substances, precipitating the chemical identity crisis of my title. Successful natural product synthesis, moreover, depended on chemists' ability to demonstrate the absolute identity of synthetic product and natural target--something late nineteenth-century chemists eventually achieved by making reliable, replicable melting and boiling point measurements. In the period before the establishment of national standards laboratories, chemists and scientific glassblowers worked together to standardize melting and boiling points as physical constants, such collaborations highlighting the essential importance of chemical glassware and glassblowing skill in the development of nineteenth-century organic chemistry.

  12. Chemical shifts of K-X-ray absorption edges on copper in different compounds by X-ray absorption spectroscopy (XAS) with Synchrotron radiation

    Energy Technology Data Exchange (ETDEWEB)

    Joseph, D., E-mail: djoseph@barc.gov.in [Nuclear Physics Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Basu, S.; Jha, S.N.; Bhattacharyya, D. [Applied Spectroscopy Division, Bhabha Atomic Research Centre, Mumbai 400085 (India)

    2012-03-01

    Cu K X-ray absorption edges were measured in compounds such as CuO, Cu(CH{sub 3}CO{sub 2}){sub 2}, Cu(CO{sub 3}){sub 2}, and CuSO{sub 4} where Cu is present in oxidation state of 2+, using the energy dispersive EXAFS beamline at INDUS-2 Synchrotron radiation source at RRCAT, Indore. Energy shifts of {approx}4-7 eV were observed for Cu K X-ray absorption edge in the above compounds compared to its value in elemental copper. The difference in the Cu K edge energy shifts in the different compounds having same oxidation state of Cu shows the effect of different chemical environments surrounding the cation in the above compounds. The above chemical effect has been quantitatively described by determining the effective charges on Cu cations in the above compounds.

  13. Chemical shifts of K-X-ray absorption edges on copper in different compounds by X-ray absorption spectroscopy (XAS) with Synchrotron radiation

    Science.gov (United States)

    Joseph, D.; Basu, S.; Jha, S. N.; Bhattacharyya, D.

    2012-03-01

    Cu K X-ray absorption edges were measured in compounds such as CuO, Cu(CH3CO2)2, Cu(CO3)2, and CuSO4 where Cu is present in oxidation state of 2+, using the energy dispersive EXAFS beamline at INDUS-2 Synchrotron radiation source at RRCAT, Indore. Energy shifts of ˜4-7 eV were observed for Cu K X-ray absorption edge in the above compounds compared to its value in elemental copper. The difference in the Cu K edge energy shifts in the different compounds having same oxidation state of Cu shows the effect of different chemical environments surrounding the cation in the above compounds. The above chemical effect has been quantitatively described by determining the effective charges on Cu cations in the above compounds.

  14. Production of Monomeric Aromatic Compounds from Oil Palm Empty Fruit Bunch Fiber Lignin by Chemical and Enzymatic Methods

    Directory of Open Access Journals (Sweden)

    Pei-Ling Tang

    2015-01-01

    Full Text Available In this study, oil palm empty fruit bunch (OPEFBF was pretreated with alkali, and lignin was extracted for further degradation into lower molecular weight phenolic compounds using enzymes and chemical means. Efficiency of monomeric aromatic compounds production from OPEFBF lignin via chemical (nitrobenzene versus oxygen and enzymatic [cutinase versus manganese peroxidase (MnP] approaches was investigated. The effects of sodium hydroxide concentration (2, 5, and 10% wt. and reaction time (30, 90, and 180 minutes on the yield of aromatic compounds were studied. The results obtained indicated that nitrobenzene oxidation produced the highest yield (333.17±49.44 ppm hydroxybenzoic acid, 5.67±0.25 ppm p-hydroxybenzaldehyde, 25.57±1.64 ppm vanillic acid, 168.68±23.23 ppm vanillin, 75.44±6.71 ppm syringic acid, 815.26±41.77 ppm syringaldehyde, 15.21±2.19 ppm p-coumaric acid, and 44.75±3.40 ppm ferulic acid, among the tested methods. High sodium hydroxide concentration (10% wt. was needed to promote efficient nitrobenzene oxidation. However, less severe oxidation condition was preferred to preserve the hydroxycinnamic acids (p-coumaric acid and ferulic acid. Cutinase-catalyzed hydrolysis was found to be more efficient than MnP-catalyzed oxidation in the production of aromatic compounds. By hydrolyzed 8% wt. of lignin with 0.625 mL cutinase g−1 lignin at pH 8 and 55°C for 24 hours, about 642.83±14.45 ppm hydroxybenzoic acid, 70.19±3.31 ppm syringaldehyde, 22.80±1.04 ppm vanillin, 27.06±1.20 ppm p-coumaric acid, and 50.19±2.23 ppm ferulic acid were produced.

  15. Quantitative determinations of chemical compounds with nutritional value from Inca crops: Chenopodium quinoa ('quinoa').

    Science.gov (United States)

    González, J A; Roldán, A; Gallardo, M; Escudero, T; Prado, F E

    1989-12-01

    Quantitative determinations of total and soluble proteins, total and free sugars, starch, total lipids, tanins, ash (Ca, Na, K, Fe, and P), and caloric value were carried out on quinoa flour. Results show that the amount of soluble proteins was higher than the standard value for wheat and maize and was very close to that of barley's. The yield of free sugars like glucose (4.55%), fructose (2.41%) and sucrose (2.39%) were also of importance. Iron and calcium levels were higher than the reported values for maize and barley. The same occurred for the caloric value (435.5 Kcal/100 g). The content of saponins was also examined since its effect on red blood cells of group A and O has been related as a potential problem of the Andes population. From the chemical analysis a more complete view about quinoa as human food was presented.

  16. Antiviral activity of Ageratina havanensis and major chemical compounds from the most active fraction

    Directory of Open Access Journals (Sweden)

    Gloria del Barrio

    2011-10-01

    Full Text Available The antiviral activity of extracts obtained from Ageratina havanensis (Kunth R.M.King & H.Rob., Asteraceae, against rabbit vesivirus (RaV (Caliciviridae and human herpes simplex viruses type 1 and 2 (HSV-1, HSV-2 (Herpesviridae were analyzed, and the main metabolites from the most active extract were isolated and characterized. The antiviral properties were investigated by measuring the inhibition of viral-induced cytopathic effect in Vero cells. The strongest inhibitory effects were found for ethyl acetate extract from leaves (SI=5 for RaV and SI=5.4 for HSV-1. The crude ethyl acetate extract was further fractionated by chromatographic methods and the structures of isolated compounds were established through comprehensive spectroscopic analyses, including IR, 2D NMR and MS. Four flavonoids were identified: 5,4'-dihydroxy-7-methoxyflavanone (sakuranetin, 3,5,4'-trihydroxy-7-methoxyflavanone (7-methoxyaromadendrin, 4'-O-β-D-glucosyl-5,3'-dihydroxy-7-methoxyflavanone (4'-O-β-D-glucosyl-7-methoxy-eriodictyol and 4'-O-β-D-glucosyl-5-hydroxy-7-methoxyflavanone (4'-O-β-D-glucosylsakuranetin. This is the first report on antiviral activity for Ageratina havanensis.

  17. Application of high-throughput affinity-selection mass spectrometry for screening of chemical compound libraries in lead discovery.

    Science.gov (United States)

    Zehender, Hartmut; Mayr, Lorenz M

    2007-02-01

    High-throughput screening of chemical libraries for compounds that interfere with a particular molecular target is among the most powerful methodologies applied in lead discovery at present. In this review, the authors describe a label-free, homogeneous, affinity-selection-based technology developed at Novartis, termed SpeedScreen, which is compared with similar technologies used for high-throughput screening in the pharmaceutical and biotechnology industries. The focus at present of SpeedScreen is twofold: first, this technology is applied to orphan genomic targets and to those targets that are non-tractable by a functional assay; second, this technology is applied complementary to the well-established traditional methodologies for the screening of molecular targets. In summary, the authors discuss the value of affinity-selection-based high-throughput screening as a complementary technology to the common functional screening platforms and the benefits as well as the limitations of this new technology are outlined.

  18. Assessing the distribution of volatile organic compounds using land use regression in Sarnia, "Chemical Valley", Ontario, Canada

    Directory of Open Access Journals (Sweden)

    Luginaah Isaac N

    2009-04-01

    Full Text Available Abstract Background Land use regression (LUR modelling is proposed as a promising approach to meet some of the challenges of assessing the intra-urban spatial variability of ambient air pollutants in urban and industrial settings. However, most of the LUR models to date have focused on nitrogen oxides and particulate matter. This study aimed at developing LUR models to predict BTEX (benzene, toluene, ethylbenzene, m/p-xylene and o-xylene concentrations in Sarnia, 'Chemical Valley', Ontario, and model the intra-urban variability of BTEX compounds in the city for a community health study. Method Using Organic Vapour Monitors, pollutants were monitored at 39 locations across the city of Sarnia for 2 weeks in October 2005. LUR models were developed to generate predictor variables that best estimate BTEX concentrations. Results Industrial area, dwelling counts, and highways adequately explained most of the variability of BTEX concentrations (R2: 0.78 – 0.81. Correlations between measured BTEX compounds were high (> 0.75. Although most of the predictor variables (e.g. land use were similar in all the models, their individual contributions to the models were different. Conclusion Yielding potentially different health effects than nitrogen oxides and particulate matter, modelling other air pollutants is essential for a better understanding of the link between air pollution and health. The LUR models developed in these analyses will be used for estimating outdoor exposure to BTEX for a larger community health study aimed at examining the determinants of health in Sarnia.

  19. Characterization of Chemical Compounds with Antioxidant and Cytotoxic Activities in Bougainvillea x buttiana Holttum and Standl, (var. Rose) Extracts

    Science.gov (United States)

    Abarca-Vargas, Rodolfo; Peña Malacara, Carlos F.; Petricevich, Vera L.

    2016-01-01

    Bougainvillea is widely used in traditional Mexican medicine to treat several diseases. This study was designed to characterize the chemical constituents of B. x buttiana extracts with antioxidant and cytotoxic activities using different solvents. The extraction solvents used were as follows: distilled water (dH2O), methanol (MeOH), acetone (DMK), ethanol (EtOH), ethyl acetate (EtOAc), dichloromethane (DCM), and hexane (Hex) (100%) at an extraction temperature of 26 °C. Analysis of bioactive compounds present in the B. x buttiana extracts included the application of common phytochemical screening assays, GC-MS analysis, and cytotoxicity and antioxidant assays. The results show that the highest extraction yield was observed with water and methanol. The maximum total phenolic content amount and highest antioxidant potential were obtained when extraction with methanol was used. With the exceptions of water and ethanol extractions, all other extracts showed cytotoxicity ranging between 31% and 50%. The prevailing compounds in water, methanol, ethanol, and acetone solvents were as follows: 4H-pyran-4-one, 2,3-dihydro-3, 5-dihydroxy-6-methyl (2), 2-propenoic acid, 3-(2-hydrophenyl)-(E)- (3), and 3-O-methyl-d-glucose (6). By contrast, the major components in the experiments using solvents such as EtOH, DMK, EtOAc, DCM, and Hex were n-hexadecanoic acid (8), 9,12-octadecadienoic acid (Z,Z) (12); 9-octadecenoic acid (E)- (13), and stigmasta-5,22-dien-3-ol (28). PMID:27918436

  20. Physico-Chemical Characterization, Bioactive Compounds and Antioxidant Activity of Malay Apple [Syzygium malaccense (L. Merr. & L.M. Perry].

    Directory of Open Access Journals (Sweden)

    Polyana Campos Nunes

    Full Text Available The purpose of this study was to evaluate the physico-chemical characteristics, bioactive compounds and antioxidant activity of Malay apple fruit (Syzygium malaccense grown in Brazil with regard to the geographical origin and its peel fractions and edible portion analyzed independently. Fruit diameter, weight, yield, and centesimal composition, ascorbic acid, reductive sugars, total soluble solids, pH and fiber content were determined. Total phenolics (1293 mg gallic acid equivalent/100 g and total anthocyanins (1045 mg/100 g contents were higher in the peel, with the major anthocyanin identified using HPLC-DAD-MS/MS as cyanidin 3-glucoside. Higher values for DPPH antiradical scavenging activity (47.52 μMol trolox equivalent antioxidant capacity/g and Ferric Reducing Antioxidant Potential (FRAP, 0.19 mM ferreous sulfate/g were also observed in the peel fraction. All extracts tested showed the ability to inhibit oxidation in the β-carotene/linoleic acid system. This study highlights the potential of Malay apple fruit as a good source of antioxidant compounds with potential benefits to human health.

  1. Effect of adding Lactobacillus plantarum and soluble carbohydrates to swine manure on odorous compounds, chemical composition and indigenous flora

    Institute of Scientific and Technical Information of China (English)

    HUANG Can; LI Ji; KANG Wen-li; TANG Xin-yan

    2006-01-01

    Manure odor, which results in the increasing complaints and lawsuits, has increased the tension among swine producers and surrounding residents. The effects of Lactobacillus plantarum and different rates of soluble carbohydrates additions to swine manure on odorous compounds, chemical compounds and indigenous flora were evaluated. Additions were calculated on dried manure weight basis. Variables monitored included ammonia (NH3), hydrogen sulfide (H2S), odor offensiveness, pH, ammonium nitrogen(NH4+-N),volatile fatty acids (VFAs), urease and indigenous flora. The results indicated that the combination of L. plantarum and soluble carbohydrates dramatically reduced manure pH. Lower pH resulted in the reduction of NH3 volatilization (34.6%-92.4%, P<0.01),the increases of H2S (P< 0.05) and NH4+-N (5.3%-17.5%, P<0.05). In addition, L. plantarum and soluble carbohydrates additions significantly reduced odor offensiveness, those VFAs related to malodor indicators(valeric acids, 12.3%-47.7%, P<0.05; iso-valeric,3.5%-23.8%) and the main microorganisms responsible for odor production, with the number of Eubacteria in swine manure reducing by 4.9%, 11.6%, 17.4%, 34.1% and 32.2% respectively.

  2. EFFECT OF GENOTYPE, SEX AND KEEPING TECHNOLOGY ON THE CHEMICAL COMPOUNDS OF BREAST AND THIGH MEAT

    Directory of Open Access Journals (Sweden)

    SZ. KONRÁD

    2013-07-01

    Full Text Available In the recent decades because of the alternative poultry meat production technologies (free range and organic farming, which are gaining ground in some of the European countries, only special slow growing breeds and hybrids can be used. The end products created by crossing the indigenous Yellow Hungarian hen with different meat type cocks were suitable for alternative keeping technology. The valuable meat parts of the pure bred Yellow Hungarian kept in free range for 84 days and the end product created with crossing (first group as well as the valuable meat parts of Ross 308 broilers fattened for 42 days in intensive keeping technology (second group were thoroughly examined in order to establish whether the genotype, sex and/or keeping technology has any kind of influence on different chemical parameters of the meat. There were no essential differences between the dry matter content of breast meat of the two different keeping technology groups (25.34 and 26.25%. However, dry matter content of thigh was 5.28 to 7.48 percentage points higher in the second group. Protein contents of breast and thigh meat were not affected by the keeping technology. Fat content of thigh meat was two and a half times higher than in the first group (6.03 and 13.73%. Thus, this study have revealed that only the ash content of breast meat affected from the keeping technology, as this parameter was higher in the first group than the second group (0.84 to 1.05 % vs 0.53 %.

  3. Chemical speciation and anthropogenic sources of ambient volatile organic compounds(VOCs)during summer in Beijing,2004

    Institute of Scientific and Technical Information of China (English)

    LU Sihua; LIU Ying; SHAO Min; HUANG Shan

    2007-01-01

    Volatile organic compounds(VOCs)were measured at six sites in Beijing in August,2004.Up to 148 VOC species,including C3 to C12 alkanes,C3 to C11 alkenes,C6 to C12 aromatics,and halogenated hydrocarbons,were quantified.Although the concentrations differed at the sites,the chemical compositions were similar,except for the Tongzhou site where aromatics were significantly high in the air.Based on the source profiles measured from previous studies,the source apportionment of ambient VOCs was preformed by deploying the chemical mass balance(CMB)model.The results show that urban VOCs are predominant from mobile source emissions,which contribute more than 50% of the VOCs(in mass concentrations)to ambient air at most sites.Other important sources are gasoline evaporation,painting,and solvents.The exception is at the Tongzhou site where vehicle exhaust,painting,and solvents have about equal contribution,around 35% of the ambient VOC concentration.As the receptor model is not valid for deriving the sources of reactive species,such as isoprene and 1,3-butadiene,other methodologies need to be further explored.

  4. Selectivity of Chemoresistive Sensors Made of Chemically Functionalized Carbon Nanotube Random Networks for Volatile Organic Compounds (VOC

    Directory of Open Access Journals (Sweden)

    Jean-François Feller

    2014-01-01

    Full Text Available Different grades of chemically functionalized carbon nanotubes (CNT have been processed by spraying layer-by-layer (sLbL to obtain an array of chemoresistive transducers for volatile organic compound (VOC detection. The sLbL process led to random networks of CNT less conductive, but more sensitive to vapors than filtration under vacuum (bucky papers. Shorter CNT were also found to be more sensitive due to the less entangled and more easily disconnectable conducting networks they are making. Chemical functionalization of the CNT’ surface is changing their selectivity towards VOC, which makes it possible to easily discriminate methanol, chloroform and tetrahydrofuran (THF from toluene vapors after the assembly of CNT transducers into an array to make an e-nose. Interestingly, the amplitude of the CNT transducers’ responses can be enhanced by a factor of five (methanol to 100 (chloroform by dispersing them into a polymer matrix, such as poly(styrene (PS, poly(carbonate (PC or poly(methyl methacrylate (PMMA. COOH functionalization of CNT was found to penalize their dispersion in polymers and to decrease the sensors’ sensitivity. The resulting conductive polymer nanocomposites (CPCs not only allow for a more easy tuning of the sensors’ selectivity by changing the chemical nature of the matrix, but they also allow them to adjust their sensitivity by changing the average gap between CNT (acting on quantum tunneling in the CNT network. Quantum resistive sensors (QRSs appear promising for environmental monitoring and anticipated disease diagnostics that are both based on VOC analysis.

  5. Identification of volatile and semivolatile compounds in chemical ionization GC-MS using a mass-to-structure (MTS) Search Engine with integral isotope pattern ranking.

    Science.gov (United States)

    Liao, Wenta; Draper, William M

    2013-02-21

    The mass-to-structure or MTS Search Engine is an Access 2010 database containing theoretical molecular mass information for 19,438 compounds assembled from common sources such as the Merck Index, pesticide and pharmaceutical compilations, and chemical catalogues. This database, which contains no experimental mass spectral data, was developed as an aid to identification of compounds in atmospheric pressure ionization (API)-LC-MS. This paper describes a powerful upgrade to this database, a fully integrated utility for filtering or ranking candidates based on isotope ratios and patterns. The new MTS Search Engine is applied here to the identification of volatile and semivolatile compounds including pesticides, nitrosoamines and other pollutants. Methane and isobutane chemical ionization (CI) GC-MS spectra were obtained from unit mass resolution mass spectrometers to determine MH(+) masses and isotope ratios. Isotopes were measured accurately with errors of Search Engine and details performance testing with over 50 model compounds.

  6. In vitro genotoxicity and cytotoxicity of five new chemical compounds of plant origin by means of the human lymphocyte micronucleus assay.

    Science.gov (United States)

    Scarpato, R; Pistelli, L; Bertoli, A; Nieri, E; Migliore, L

    1998-04-01

    The micronucleus test in human peripheral lymphocytes is widely used in toxicology for the assessment of the genotoxic profile of chemical compounds of environmental concern. The aim of this study was to evaluate the genotoxic, cytotoxic and antimitotic activity of five new compounds isolated from Prunus africana Hook or from Bupleurum fruticosum L. The experiments were conducted only in vitro. Results showed that none of the plant extracts, tested over a wide range of concentrations, increased the frequency of micronuclei. Only compounds 2 and 5 were found to be toxic for phytohaemagglutinin-stimulated lymphocytes at the maximum dose used. reserved.

  7. jCompoundMapper: An open source Java library and command-line tool for chemical fingerprints

    Directory of Open Access Journals (Sweden)

    Hinselmann Georg

    2011-01-01

    Full Text Available Abstract Background The decomposition of a chemical graph is a convenient approach to encode information of the corresponding organic compound. While several commercial toolkits exist to encode molecules as so-called fingerprints, only a few open source implementations are available. The aim of this work is to introduce a library for exactly defined molecular decompositions, with a strong focus on the application of these features in machine learning and data mining. It provides several options such as search depth, distance cut-offs, atom- and pharmacophore typing. Furthermore, it provides the functionality to combine, to compare, or to export the fingerprints into several formats. Results We provide a Java 1.6 library for the decomposition of chemical graphs based on the open source Chemistry Development Kit toolkit. We reimplemented popular fingerprinting algorithms such as depth-first search fingerprints, extended connectivity fingerprints, autocorrelation fingerprints (e.g. CATS2D, radial fingerprints (e.g. Molprint2D, geometrical Molprint, atom pairs, and pharmacophore fingerprints. We also implemented custom fingerprints such as the all-shortest path fingerprint that only includes the subset of shortest paths from the full set of paths of the depth-first search fingerprint. As an application of jCompoundMapper, we provide a command-line executable binary. We measured the conversion speed and number of features for each encoding and described the composition of the features in detail. The quality of the encodings was tested using the default parametrizations in combination with a support vector machine on the Sutherland QSAR data sets. Additionally, we benchmarked the fingerprint encodings on the large-scale Ames toxicity benchmark using a large-scale linear support vector machine. The results were promising and could often compete with literature results. On the large Ames benchmark, for example, we obtained an AUC ROC performance of 0

  8. Characterization of Chemical Compounds with Antioxidant and Cytotoxic Activities in Bougainvillea x buttiana Holttum and Standl, (var. Rose Extracts

    Directory of Open Access Journals (Sweden)

    Rodolfo Abarca-Vargas

    2016-12-01

    Full Text Available Bougainvillea is widely used in traditional Mexican medicine to treat several diseases. This study was designed to characterize the chemical constituents of B. x buttiana extracts with antioxidant and cytotoxic activities using different solvents. The extraction solvents used were as follows: distilled water (dH2O, methanol (MeOH, acetone (DMK, ethanol (EtOH, ethyl acetate (EtOAc, dichloromethane (DCM, and hexane (Hex (100% at an extraction temperature of 26 °C. Analysis of bioactive compounds present in the B. x buttiana extracts included the application of common phytochemical screening assays, GC-MS analysis, and cytotoxicity and antioxidant assays. The results show that the highest extraction yield was observed with water and methanol. The maximum total phenolic content amount and highest antioxidant potential were obtained when extraction with methanol was used. With the exceptions of water and ethanol extractions, all other extracts showed cytotoxicity ranging between 31% and 50%. The prevailing compounds in water, methanol, ethanol, and acetone solvents were as follows: 4H-pyran-4-one, 2,3-dihydro-3, 5-dihydroxy-6-methyl (2, 2-propenoic acid, 3-(2-hydrophenyl-(E- (3, and 3-O-methyl-d-glucose (6. By contrast, the major components in the experiments using solvents such as EtOH, DMK, EtOAc, DCM, and Hex were n-hexadecanoic acid (8, 9,12-octadecadienoic acid (Z,Z (12; 9-octadecenoic acid (E- (13, and stigmasta-5,22-dien-3-ol (28.

  9. Chemical composition and biological activity of four salvia essential oils and individual compounds against two species of mosquitoes.

    Science.gov (United States)

    Ali, Abbas; Tabanca, Nurhayat; Demirci, Betul; Blythe, Eugene K; Ali, Zulfiqar; Baser, K Husnu Can; Khan, Ikhlas A

    2015-01-21

    The chemical compositions of essential oils obtained from four species of genus Salvia were analyzed by gas chromatography with a flame ionization detector (GC-FID) and gas chromatography-mass spectrometry (GC-MS). The main compounds identified from Salvia species essential oils were as follows: 1,8-cineole (71.7%), α-pinene (5.1%), camphor (4.4%), and β-pinene (3.8%) in Salvia apiana; borneol (17.4%), β-eudesmol (10.4%), bornyl acetate (5%), and guaiol (4.8%) in Salvia elegans; bornyl acetate (11.4%), β-caryophyllene (6.5%), caryophyllene oxide (13.5%), and spathulenol (7.0%) in Salvia leucantha; α-thujene (25.8%), viridiflorol (20.4%), β-thujene (5.7%), and camphor (6.4%) in Salvia officinalis. In biting-deterrent bioassays, essential oils of S. leucantha and S. elegans at 10 μg/cm(2) showed activity similar to that of DEET (97%, N, N-diethyl-m-toluamide) in two species of mosquitoes, whereas the activities of S. officinalis and S. apiana essential oils were lower than those of the other oils or DEET. Pure compounds β-eudesmol and guaiol showed biting-deterrent activity similar to DEET at 25 nmol/cm(2), whereas the activity of 13-epi-manool, caryophyllene oxide, borneol, bornyl acetate, and β-caryophyllene was significantly lower than that of β-eudesmol, guaiol, or DEET. All essential oils showed larvicidal activity except that of S. apiana, which was inactive at the highest dose of 125 ppm against both mosquito species. On the basis of 95% CIs, all of the essential oils showed higher toxicity in Anopheles quadrimaculatus than in Aedes aegypti. The essential oil of S. leucantha with an LC50 value of 6.2 ppm showed highest toxicity in An. quadrimaculatus.

  10. Impact of the chemical and physical stability of ketoprofen compounded in various pharmaceutical bases on its topical and transdermal delivery.

    Science.gov (United States)

    Nornoo, Adwoa O; Wulz, Jordan; Yoon, Haena; Nan, Yu; Lese, Michele

    2016-03-01

    Increasing demands for individualized drug treatment has led to an increase in the practice of compounded medications. In this study, we determined the impact of the chemical and physical stability of ketoprofen (10%w/w) cream on its topical/transdermal delivery over a 6-month period. The shelf life of ketoprofen at 25 °C in the pharmaceutical bases LipoDerm and LipoBase (109.94 and 85.9 days) was significantly longer than that in Pluronic Lecithin Organogel (PLO; 44.81 days), justifying extending its beyond use date (BUD) from 30 (USP37/NF32) to at least 60 days in LipoDerm and LipoBase. All the creams evaluated exhibited shear-thinning flow behavior with moderate thixotropy, while the flow properties for LipoBase and PLO creams were altered at storage times greater than 90 days. The percentage of ketoprofen permeated through porcine ear skin was 13.7, 19.1 and 12.7% of the dose from LipoDerm, LipoBase and PLO, respectively and decreased 2- to 3-fold after 28 days of storage. Flux ranging from 85.3 to 446.7 µg/cm(2)/h and topical delivery, on the other hand, were not influenced by storage duration past 28 days. In conclusion, this study justifies extending the BUD of ketoprofen in LipoDerm and LipoBase to 60 days if used for topical delivery only.

  11. Influence of extraction techniques on physical-chemical characteristics and volatile compounds of extra virgin olive oil.

    Science.gov (United States)

    Volpe, Maria Grazia; De Cunzo, Fausta; Siano, Francesco; Paolucci, Marina; Barbarisi, Costantina; Cammarota, Giancarlo

    2014-01-01

    The purpose of this study was to investigate three types of extraction methods of extra virgin olive oil (EVOO) from the same cultivar (Ortice olive cultivar): traditional or pressing (T) system, decanter centrifugation (DC) system and a patented horizontal axis decanter centrifugation (HADC) system. Oil samples were subjected to chemical analyses: free acidity, peroxide value, ultraviolet light absorption K232 and K270, total polyphenols, antioxidant capacity, volatile compounds and olfactory characteristics by electronic nose. The two centrifugation systems showed better free acidity and peroxides value but total polyphenol content was particularly high in extra virgin olive oil produced by patented HADC system. Same volatile substances that positively characterize the oil aroma were found in higher amount in the two centrifugation systems, although some differences have been detected between DC and HADC system, other were found in higher amount in extra virgin olive oil produced by T system. The electronic nose analysis confirmed these results, principal component analysis (PCA) and correlation matrix showed the major differences between EVOO produced by T and HADC system. Taken together the results showed that DC and HADC systems produce EVOO with better characteristics than T system and patented HADC is the best extraction system.

  12. Formation of intermetallic compound at interface between rare earth elements and ferritic-martensitic steel by fuel cladding chemical interaction

    Institute of Scientific and Technical Information of China (English)

    Jun Hwan Kim; Byoung Oon Lee; Chan Bock Lee; Seung Hyun Jee; Young Soo Yoon

    2012-01-01

    The intermetallic compounds formation at interface between rare earth elements and clad material were investigated to demonstrate the effects of rare earth elements on fuel-cladding chemical interaction (FCCI) behavior.Mischmetal (70Ce-30La) and Nd were prepared as rare earth elements.Diffusion couple testing was performed on the rare earth elements and cladding (9Cr2W steel) near the operation temperature of(sodium-cooled fast reactor) SFR fuel.The performance of a diffusion barrier consisting of Zr and V metallic foil against the rare earth elements was also evaluated.Our results showed that Ce and Nd in the rare earth elements and Fe in the clad material interdiffused and reacted to form intermetallic species according to the parabolic rate law,describing the migration of the rare earth element.The diffusion of Fe limited the reaction progress such that the entire process was governed by the cubic rate law.Rare earth materials could be used as a surrogate for high burnup metallic fuels,and the performance of the barrier material was demonstrated to be effective.

  13. Pharmaceutically active compounds and endocrine disrupting chemicals in water, sediments and mollusks in mangrove ecosystems from Singapore.

    Science.gov (United States)

    Bayen, Stéphane; Estrada, Elvagris Segovia; Juhel, Guillaume; Kit, Lee Wei; Kelly, Barry C

    2016-08-30

    This study investigated the occurrence of bisphenol A (BPA), atrazine and selected pharmaceutically active compounds (PhACs) in mangrove habitats in Singapore in 2012-2013, using multiple tools (sediment sampling, POCIS and filter feeder molluscs). Using POCIS, the same suite of contaminants (atrazine, BPA and eleven PhACs) was detected in mangrove waters in 28-days deployments in both 2012 and 2013. POCIS concentrations ranged from pg/L to μg/L. Caffeine, BPA, carbamazepine, E1, triclosan, sulfamerazine, sulfamethazine, and lincomycin were also detected in mangrove sediments from the low pg/g dw (e.g. carbamazepine) to ng/g dw (e.g. BPA). The detection of caffeine, carbamazepine, BPA, sulfamethoxazole or lincomycin in bivalve tissues also showed that these chemicals are bioavailable in the mangrove habitat. Since there are some indications that some pharmaceutically active substances may be biologically active in the low ppb range in marine species, further assessment should be completed based on ecotoxicological data specific to mangrove species.

  14. The Lattice Compatibility Theory LCT: Physical and Chemical Arguments from the Growth Behavior of Doped Compounds in terms of Bandgap Distortion and Magnetic Effects

    Directory of Open Access Journals (Sweden)

    K. Boubaker

    2013-01-01

    Full Text Available Physical and chemical arguments for the recently discussed materials-related Lattice Compatibility Theory are presented. The discussed arguments are based on some differences of Mn ions incorporation kinetics inside some compounds. These differences have been evaluated and quantified in terms of alteration of bandgap edges, magnetic patterns, and Faraday effect.

  15. Chemical composition and bioactive compounds of garlic (Allium sativum L.) as affected by pre- and post-harvest conditions: A review.

    Science.gov (United States)

    Martins, Natália; Petropoulos, Spyridon; Ferreira, Isabel C F R

    2016-11-15

    Garlic (Allium sativum L.) is considered one of the twenty most important vegetables, with various uses throughout the world, either as a raw vegetable for culinary purposes, or as an ingredient of traditional and modern medicine. Furthermore, it has also been proposed as one of the richest sources of total phenolic compounds, among the usually consumed vegetables, and has been highly ranked regarding its contribution of phenolic compounds to human diet. This review aims to examine all the aspects related with garlic chemical composition and quality, focusing on its bioactive properties. A particular emphasis is given on the organosulfur compounds content, since they highly contribute to the effective bioactive properties of garlic, including its derived products. The important effects of pre-harvest (genotype and various cultivation practices) and post-harvest conditions (storage conditions and processing treatments) on chemical composition and, consequently, bioactive potency of garlic are also discussed.

  16. Chemical Profiles and Identification of Key Compound Caffeine in Marine-Derived Traditional Chinese Medicine Ostreae concha

    Directory of Open Access Journals (Sweden)

    Hong-Bing Liu

    2012-05-01

    Full Text Available To compare the chemical differences between the medicinal and cultured oyster shells, their chemical profiles were investigated. Using the ultra performance liquid chromatography-electron spraying ionization-mass spectrometry (UPLC-ESI-MS, combined with principal component analysis (PCA and orthogonal projection to latent structures discriminant analysis (OPLS-DA, the discrimination of the chemical characteristics among the medicinal and cultured oyster shells was established. Moreover, the chemometric analysis revealed some potential key compounds. After a large-scale extraction and isolation, one target key compound was unambiguously identified as caffeine (1 based on extensive spectroscopic data analysis (1D and 2D NMR, MS, and UV and comparison with literature data.

  17. Hot wire chemical vapor deposition chemistry in the gas phase and on the catalyst surface with organosilicon compounds.

    Science.gov (United States)

    Shi, Yujun

    2015-02-17

    CONSPECTUS: Hot wire chemical vapor deposition (HWCVD), also referred to as catalytic CVD (Cat-CVD), has been used to produce Si-containing thin films, nanomaterials, and functional polymer coatings that have found wide applications in microelectronic and photovoltaic devices, in automobiles, and in biotechnology. The success of HWCVD is largely due to its various advantages, including high deposition rate, low substrate temperatures, lack of plasma-induced damage, and large-area uniformity. Film growth in HWCVD is induced by reactive species generated from primary decomposition on the metal wire or from secondary reactions in the gas phase. In order to achieve a rational and efficient optimization of the process, it is essential to identify the reactive species and to understand the chemical kinetics that govern the production of these precursor species for film growth. In this Account, we report recent progress in unraveling the complex gas-phase reaction chemistry in the HWCVD growth of silicon carbide thin films using organosilicon compounds as single-source precursors. We have demonstrated that laser ionization mass spectrometry is a powerful diagnostic tool for studying the gas-phase reaction chemistry when combined with the methods of isotope labeling and chemical trapping. The four methyl-substituted silane molecules, belonging to open-chain alkylsilanes, dissociatively adsorb on W and Ta filaments to produce methyl radical and H2 molecule. Under the typical deposition pressures, with increasing number of methyl substitution, the dominant chemistry occurring in the gas phase switches from silylene/silene reactions to free-radical short chain reactions. This change in dominant reaction intermediates from silylene/silene to methyl radicals explains the observation from thin film deposition that silicon carbide films become more C-rich with a decreasing number of Si-H bonds in the four precursor molecules. In the case of cyclic monosilacyclobutanes, we have

  18. Chemical vapor deposition and characterization of polysilanes polymer based thin films and their applications in compound semiconductors and silicon devices

    Science.gov (United States)

    Oulachgar, El Hassane

    . This work has demonstrated that a polysilane polymeric source can be used to deposit a wide range of thin film materials exhibiting similar properties with conventional ceramic materials such as silicon carbide (SiC), silicon oxynitride (SiON), silicon oxycarbide (SiOC) silicon dioxide (SiO2) and silicon nitride (Si3N4). The strict control of the deposition process allows precise control of the electrical, optical and chemical properties of polymer-based thin films within a broad range. This work has also demonstrated for the first time that poly(dimethylsilmaes) polymers deposited by CVD can be used to effectively passivate both silicon and gallium arsenide MOS devices. This finding makes polymer-based thin films obtained by CVD very promising for the development of high-kappa dielectric materials for next generation high-mobility CMOS technology. Keywords. Thin films, Polymers, Vapor Phase Deposition, CVD, Nanodielectrics, Organosilanes, Polysilanes, GaAs Passivation, MOSFET, Silicon Oxynitride, Integrated Waveguide, Silicon Carbide, Compound Semiconductors.

  19. Estimation of Secondary Compounds Concentrations Contributed by Biogenic VOC With Chemical Transport Model in the Central Area of Japan

    Science.gov (United States)

    Yamamoto, K.; Kanemaru, A.; Okumura, M.; Tohno, S.

    2008-12-01

    meteorological fields was used for estimating secondary produced compounds concentration in the Kansai region. While the emission amount data of BVOC is also included in the EAGrid-Japan database, constructed by A. Kannari et al., another simulation with this existing BVOC emission inventory was conducted. As for other emission inventories of precursors, EAGrid-Japan was also used in both simulations. According to the result of estimation of BVOC emission, the total amount of BVOC is almost same as that of EAGrid-Japan, however, the ratio of isoprene to total BVOC emission is quite low in our estimation, due to the used vegetation map in this study, and the configuration of basic emission parameter in Autumn and Winter which is set to zero. According to the result of atmospheric chemical transport simulation with this developed BVOC inventory, oxidant concentrations are lower than observed values. This result suggests that the amount of isoprene emission strongly affected on the concentrations of oxidants, therefore, more accurate vegetation map data as a basis of BVOC emissions should be developed.

  20. Other compounds isolated from Simira glaziovii and the {sup 1}H and {sup 13}C NMR chemical shift assignments of new 1-epi-castanopsol

    Energy Technology Data Exchange (ETDEWEB)

    Araujo, Marcelo F. de; Vieira, Ivo J. Curcino [Universidade Federal Rural do Rio de Janeiro, Seropedica, RJ (Brazil). Dept. de Quimica; Braz-Filho, Raimundo [Universidade Estadual do Norte Fluminense (UENF), Campos dos Goytacases, RJ (Brazil). Centro de Ciencias Tecnologicas. Lab. de Ciencias Quimicas; Carvalho, Mario G. de, E-mail: mgeraldo@ufrrj.br [Universidade Federal do Rio de Janeiro (NPPN/UFRJ), RJ (Brazil). Centro de Ciencias da Saude. Nucleo de Pesquisa em Produtos Naturais

    2012-07-01

    A new triterpene, 1-epi-castanopsol, besides eleven known compounds: sitosterol, stigmasterol, campesterol, lupeol, lupenone, simirane B, syringaresinol, scopoletin, isofraxidin, 6,7,8-trimethoxycoumarin and harman, were isolated from the wood of Simira glaziovii. The structures of the known compounds were defined by 1D, 2D {sup 1}H, {sup 13}C NMR spectra data analyses and comparison with literature data. The detailed spectral data analyses allowed the definition of the structure of the new 1-epi isomer of castanopsol and performance of {sup 1}H and {sup 13}C NMR chemical shift assignments. (author)

  1. Crystal Structures of Peptide Deformylase from Rice Pathogen Xanthomonas oryzae pv. oryzae in Complex with Substrate Peptides, Actinonin, and Fragment Chemical Compounds.

    Science.gov (United States)

    Ngo, Ho-Phuong-Thuy; Ho, Thien-Hoang; Lee, Inho; Tran, Huyen-Thi; Sur, Bookyo; Kim, Seunghwan; Kim, Jeong-Gu; Ahn, Yeh-Jin; Cha, Sun-Shin; Kang, Lin-Woo

    2016-10-05

    Xanthomonas oryzae pv. oryzae (Xoo) causes bacterial blight on rice; this species is one of the most destructive pathogenic bacteria in rice cultivation worldwide. Peptide deformylase (PDF) catalyzes the removal of the N-formyl group from the N-terminus of newly synthesized polypeptides in bacterial cells and is an important target to develop antibacterial agents. We determined crystal structures of Xoo PDF (XoPDF) at up to 1.9 Å resolution, which include apo, two substrate-bound (methionine-alanine or methionine-alanine-serine), an inhibitor-bound (actinonin), and six fragment chemical-bound structures. Six fragment chemical compounds were bound in the substrate-binding pocket. The fragment chemical-bound structures were compared to the natural PDF inhibitor actinonin-bound structure. The fragment chemical molecules will be useful to design an inhibitor specific to XoPDF and a potential pesticide against Xoo.

  2. CHEMICALS

    CERN Multimedia

    Medical Service

    2002-01-01

    It is reminded that all persons who use chemicals must inform CERN's Chemistry Service (TIS-GS-GC) and the CERN Medical Service (TIS-ME). Information concerning their toxicity or other hazards as well as the necessary individual and collective protection measures will be provided by these two services. Users must be in possession of a material safety data sheet (MSDS) for each chemical used. These can be obtained by one of several means : the manufacturer of the chemical (legally obliged to supply an MSDS for each chemical delivered) ; CERN's Chemistry Service of the General Safety Group of TIS ; for chemicals and gases available in the CERN Stores the MSDS has been made available via EDH either in pdf format or else via a link to the supplier's web site. Training courses in chemical safety are available for registration via HR-TD. CERN Medical Service : TIS-ME :73186 or service.medical@cern.ch Chemistry Service : TIS-GS-GC : 78546

  3. Response of Paenibacillus polymyxa to iron: alternations in cellular chemical composition and the production of fusaricidin type antimicrobial compounds

    Directory of Open Access Journals (Sweden)

    Waseem Raza

    2010-10-01

    Full Text Available In this work, growth, cellular chemical composition and production of fusaricidin type antimicrobial compounds by P. polymyxa SQR-21 were compared in tryptone broth supplemented with four concentrations of iron (25, 50, 100 and 200 µM. The data revealed that the growth of P. polymyxa SQR-21 was increased by 3-8% with the increase in concentration of ferric ion (Fe3+. The production of fusaricidin type compounds was increased by 33-49% only up to 50 µM Fe3+ and the highest level of Fe3+ was inhibitory. Increase in the liquid culture Fe3+concentration increased the intracellular protein (2%, intracellular carbohydrate (14%, extracellular protein (7% and polysaccharide contents (18% while the intracellular lipid contents were increased (11% only up to 50 µM Fe3+. In addition, the regulatory effects of Fe3+ were also reflected by the increase in total RNA contents and relative expression of the fusaricidin synthetase gene (FusA by 3-13 and 35-56%, respectively, up to 50 µM Fe3+, after that a continuous decrease was observed.Tipo compostos do fusaricidin do produto das tensões do polymyxa de Paenibacillus que é ativo de encontro a uma variedade larga das bactérias e de fungos gram-positive. O crescimento, a composição química celular e a produção do fusaricidin datilografam compostos antimicrobial pelo P. o polymyxa SQR-21 foi comparado no caldo de carne do tryptone suplementado com as quatro concentrações (25, µM 50, 100 e 200 do ferro. Os dados revelaram que o crescimento do P. o polymyxa foi aumentado por 3-8% com o aumento na concentração do íon férrico (Fe3+ e o tipo produção do fusaricidin dos compostos foi aumentado 33-49% somente até 50 pelo µM Fe3+ quando o nível o mais elevado de Fe3+ era inhibitory. O aumento na concentração de Fe3+ na cultura líquida aumentou a proteína intracellular (2% e os índices de hidrato de carbono (14% e a proteína extracellular (7% e os índices do polysaccharide (18% quando os

  4. Reducing excess sludge in a biological treatment system using chemical compounds; Reduccion de fangos en exceso de un sistema biologico de depuracion mediante el empleo de compuestos quimicos

    Energy Technology Data Exchange (ETDEWEB)

    Aragon Cruz, C.; Quiroga Alonso, J. M.; Coello Oviedo, M. D.

    2009-07-01

    In the active sludge treatment of waste water, the generation of residual sludge is a major proble due to the cost of dealing with it and the dwindling number of place for disposing of it. A proposal is made for minimising the amount of excess sludge generated using chemical compounds that uncouple its metabolism. An assessment is made of the effectiveness of four such chemical compounds, two organic (2,4-dinitrophenol DNP-and 3,3', 4',5-tetrachlorosalicylanilide- TCS) and two metals (copper and zinc) in order to obtain the optimum amount required. It was found that both TCS and zinc can reduce the bacteria growth rate (Yobs) by over 30% without hardly affecting the elimination organic matter. (Author) 22 refs.

  5. Behavior of radon, chemical compounds and stable elements in underground water; Comportamiento de radon, compuestos quimicos y elementos estables en agua subterranea

    Energy Technology Data Exchange (ETDEWEB)

    Lopez R, N.; Segovia, N.; Lopez, M.B.E.; Pena, P. [Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, 11801 Mexico D.F. (Mexico); Armienta, M.A.; Godinez, L. [IGFUNAM, Ciudad Universitaria, 04510 Mexico D.F. (Mexico); Seidel, J.L. [ISTEEM, M.S.E. Montpellier (France)

    2001-07-01

    The radon behavior, chemical compounds, major and trace elements in water samples of four springs and three wells of urban and agricultural zones around the Jocotitlan volcano and El Oro region was determined, both of them located in the medium part of the Mexican neo-volcanic axis. The {sup 222} Rn was measured by the liquid scintillation method, the analysis of major components was realized with conventional chemical techniques, while the trace elements were quantified using an Icp-Ms. The average values of the radon concentrations obtained during one year were constant relatively, in an interval from 0.97 to 4.99 Bq/lt indicating a fast transport from the reload area toward the sampling points. the compounds, major and trace elements showed differences which indicate distinct origins of water from the site studies. (Author)

  6. Selection of quantum chemical descriptors by chemometric methods in the study of antioxidant activity of flavonoid compounds

    Science.gov (United States)

    Weber, K. C.; Honório, K. M.; da Silva, S. L.; Mercadante, R.; da Silva, A. B. F.

    In the present study, the aim was to select electronic properties responsible for free radical scavenging ability of a set of 25 flavonoid compounds employing chemometric methods. Electronic parameters were calculated using the AM1 semiempirical method, and chemometric methods (principal component analysis, hierarchical cluster analysis, and k-nearest neighbor) were used with the aim to build models able to find relationships between electronic features and the antioxidant activity presented by the compounds studied. According to these models, four electronic variables can be considered important to discriminate more and less antioxidant flavonoid compounds: polarizability (α), charge at carbon 3 (QC3), total charge at substituent 5 (QS5), and total charge at substituent 3' (QS3'). The features found as being responsible for the antioxidant activity of the flavonoid compounds studied are consistent with previous results found in the literature. The results obtained can also bring improvements in the search for better antioxidant flavonoid compounds.

  7. Minocycline and doxycycline, but not other tetracycline-derived compounds, protect liver cells from chemical hypoxia and ischemia/reperfusion injury by inhibition of the mitochondrial calcium uniporter

    Energy Technology Data Exchange (ETDEWEB)

    Schwartz, Justin; Holmuhamedov, Ekhson; Zhang, Xun; Lovelace, Gregory L.; Smith, Charles D. [Department of Drug Discovery and Biomedical Sciences, Medical University of South Carolina, Charleston, SC (United States); Lemasters, John J., E-mail: JJLemasters@musc.edu [Department of Drug Discovery and Biomedical Sciences, Medical University of South Carolina, Charleston, SC (United States); Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, SC (United States)

    2013-11-15

    Minocycline, a tetracycline-derived compound, mitigates damage caused by ischemia/reperfusion (I/R) injury. Here, 19 tetracycline-derived compounds were screened in comparison to minocycline for their ability to protect hepatocytes against damage from chemical hypoxia and I/R injury. Cultured rat hepatocytes were incubated with 50 μM of each tetracycline-derived compound 20 min prior to exposure to 500 μM iodoacetic acid plus 1 mM KCN (chemical hypoxia). In other experiments, hepatocytes were incubated in anoxic Krebs–Ringer–HEPES buffer at pH 6.2 for 4 h prior to reoxygenation at pH 7.4 (simulated I/R). Tetracycline-derived compounds were added 20 min prior to reperfusion. Ca{sup 2+} uptake was measured in isolated rat liver mitochondria incubated with Fluo-5N. Cell killing after 120 min of chemical hypoxia measured by propidium iodide (PI) fluorometry was 87%, which decreased to 28% and 42% with minocycline and doxycycline, respectively. After I/R, cell killing at 120 min decreased from 79% with vehicle to 43% and 49% with minocycline and doxycycline. No other tested compound decreased killing. Minocycline and doxycycline also inhibited mitochondrial Ca{sup 2+} uptake and suppressed the Ca{sup 2+}-induced mitochondrial permeability transition (MPT), the penultimate cause of cell death in reperfusion injury. Ru360, a specific inhibitor of the mitochondrial calcium uniporter (MCU), also decreased cell killing after hypoxia and I/R and blocked mitochondrial Ca{sup 2+} uptake and the MPT. Other proposed mechanisms, including mitochondrial depolarization and matrix metalloprotease inhibition, could not account for cytoprotection. Taken together, these results indicate that minocycline and doxycycline are cytoprotective by way of inhibition of MCU. - Highlights: • Minocycline and doxycycline are the only cytoprotective tetracyclines of those tested • Cytoprotective tetracyclines inhibit the MPT and mitochondrial calcium and iron uptake. • Cytoprotective

  8. Using the chemical equilibrium partitioning space to explore factors influencing the phase distribution of compounds involved in secondary organic aerosol formation

    OpenAIRE

    F. Wania; Lei, Y. D.; Wang, C.; Abbatt, J. P. D.; Goss, K.-U.

    2015-01-01

    Many atmospheric and chemical variables influence the partitioning equilibrium between gas phase and condensed phases of compounds implicated in the formation of secondary organic aerosol (SOA). The large number of factors and their interaction makes it often difficult to assess their relative importance and concerted impact. Here we introduce a two-dimensional space which maps regions of dominant atmospheric phase distribution within a coordinate system defined by equilibri...

  9. Using the chemical equilibrium partitioning space to explore factors influencing the phase distribution of compounds involved in secondary organic aerosol formation

    OpenAIRE

    F. Wania; Lei, Y. D.; Wang, C.; Abbatt, J. P. D.; K.-U. Goss

    2014-01-01

    Many atmospheric and chemical variables influence the partitioning equilibrium between gas phase and condensed phases of compounds implicated in the formation of secondary organic aerosol (SOA). The large number of factors and their interaction makes it often difficult to assess their relative importance and concerted impact. Here we introduce a two-dimensional space, which maps regions of dominant atmospheric phase distribution within a coordinate system de...

  10. A SAW-Based Chemical Sensor for Detecting Sulfur-Containing Organophosphorus Compounds Using a Two-Step Self-Assembly and Molecular Imprinting Technology

    Directory of Open Access Journals (Sweden)

    Yong Pan

    2014-05-01

    Full Text Available This paper presents a new effective approach for the sensitive film deposition of surface acoustic wave (SAW chemical sensors for detecting organophosphorus compounds such as O-ethyl-S-2-diisopropylaminoethyl methylphosphonothiolate (VX containing sulfur at extremely low concentrations. To improve the adsorptive efficiency, a two-step technology is proposed for the sensitive film preparation on the SAW delay line utilizing gold electrodes. First, mono[6-deoxy-6-[(mercaptodecamethylenethio

  11. Predicting chemically-induced skin reactions. Part I: QSAR models of skin sensitization and their application to identify potentially hazardous compounds

    Energy Technology Data Exchange (ETDEWEB)

    Alves, Vinicius M. [Laboratory of Molecular Modeling and Design, Faculty of Pharmacy, Federal University of Goiás, Goiânia, GO 74605-220 (Brazil); Laboratory for Molecular Modeling, Division of Chemical Biology and Medicinal Chemistry, Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, NC 27599 (United States); Muratov, Eugene [Laboratory for Molecular Modeling, Division of Chemical Biology and Medicinal Chemistry, Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, NC 27599 (United States); Laboratory of Theoretical Chemistry, A.V. Bogatsky Physical-Chemical Institute NAS of Ukraine, Odessa 65080 (Ukraine); Fourches, Denis [Laboratory for Molecular Modeling, Division of Chemical Biology and Medicinal Chemistry, Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, NC 27599 (United States); Strickland, Judy; Kleinstreuer, Nicole [ILS/Contractor Supporting the NTP Interagency Center for the Evaluation of Alternative Toxicological Methods (NICEATM), P.O. Box 13501, Research Triangle Park, NC 27709 (United States); Andrade, Carolina H. [Laboratory of Molecular Modeling and Design, Faculty of Pharmacy, Federal University of Goiás, Goiânia, GO 74605-220 (Brazil); Tropsha, Alexander, E-mail: alex_tropsha@unc.edu [Laboratory for Molecular Modeling, Division of Chemical Biology and Medicinal Chemistry, Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, NC 27599 (United States)

    2015-04-15

    Repetitive exposure to a chemical agent can induce an immune reaction in inherently susceptible individuals that leads to skin sensitization. Although many chemicals have been reported as skin sensitizers, there have been very few rigorously validated QSAR models with defined applicability domains (AD) that were developed using a large group of chemically diverse compounds. In this study, we have aimed to compile, curate, and integrate the largest publicly available dataset related to chemically-induced skin sensitization, use this data to generate rigorously validated and QSAR models for skin sensitization, and employ these models as a virtual screening tool for identifying putative sensitizers among environmental chemicals. We followed best practices for model building and validation implemented with our predictive QSAR workflow using Random Forest modeling technique in combination with SiRMS and Dragon descriptors. The Correct Classification Rate (CCR) for QSAR models discriminating sensitizers from non-sensitizers was 71–88% when evaluated on several external validation sets, within a broad AD, with positive (for sensitizers) and negative (for non-sensitizers) predicted rates of 85% and 79% respectively. When compared to the skin sensitization module included in the OECD QSAR Toolbox as well as to the skin sensitization model in publicly available VEGA software, our models showed a significantly higher prediction accuracy for the same sets of external compounds as evaluated by Positive Predicted Rate, Negative Predicted Rate, and CCR. These models were applied to identify putative chemical hazards in the Scorecard database of possible skin or sense organ toxicants as primary candidates for experimental validation. - Highlights: • It was compiled the largest publicly-available skin sensitization dataset. • Predictive QSAR models were developed for skin sensitization. • Developed models have higher prediction accuracy than OECD QSAR Toolbox. • Putative

  12. Is there a chemical interaction between calcium phosphates and organic compounds in the organic/inorganic composites?

    Energy Technology Data Exchange (ETDEWEB)

    Dorozhkin, S.V. [Research Inst. of Fertilisers, Moscow (Russian Federation)

    2001-07-01

    Solid composites of three biologically relevant calcium phosphates and hydroxypropylmethylcellulose (HPMC) were prepared at temperatures of 121 C. Properties of the composites obtained were studied by FTIR, X-ray diffraction, and SEM techniques. Special attention was devoted to seeking of a possible chemical interaction between the calcium phosphates and HPMC. No chemical interaction was found. Thus, HPMC was proven to have no influence on the chemical properties of calcium phosphates. (orig.)

  13. Cobalt(II Coordination Compounds of Ethyl 4-Methyl-5-Imidazolecarboxylate: Chemical and Biochemical Characterization on Photosynthesis and Seed Germination

    Directory of Open Access Journals (Sweden)

    Beatriz King-Díaz

    2005-01-01

    chloroplasts. Seed germination and seedling growth of the monocotyledonous species Lolium multiflorum and Triticum aestivum and the dicotyledonous species Trifolium alexandrinum and Physalis ixocarpa were also assayed under the effect of the compounds and salts. The results showed that cobalt(II salts and their emizco coordination compounds inhibit photosynthetic electron flow and ATP-synthesis, behaving as Hill reaction inhibitors. Coordination compounds are more potent inhibitors than the salts. It was found that the salts target is at the b6f level while the complexes targets are at QB(D1-protein and b6f level. The QB inhibition site was confirmed by variable chlorophyll a fluorescence yield. On the other hand, emizco inhibits seed germination, root and shoot development, in both weed and crop species. Cobalt(II coordination compounds are the most effective photosynthesis inhibitors, but they are less potent than emizco in germination and seedling growth, while the metal salts are the least active of all.

  14. Identification of compounds in heavy fuel oil that are chronically toxic to rainbow trout embryos by effects-driven chemical fractionation.

    Science.gov (United States)

    Adams, Julie; Bornstein, Jason M; Munno, Keenan; Hollebone, Bruce; King, Thomas; Brown, R Stephen; Hodson, Peter V

    2014-04-01

    The present study isolated and identified compounds in heavy fuel oil 7102 (HFO 7102) that are bioavailable and chronically toxic to rainbow trout embryos (Oncorhynchus mykiss). An effects-driven chemical fractionation combined the chemical separation of oil with toxicity testing and chemical analyses of each fraction to identify the major classes of compounds associated with embryo toxicity. Toxicity was assessed with 2 exposure methods, a high-energy chemical dispersion of oil in water, which included oil droplets in test solutions, and water accommodated fractions which were produced by oiled gravel desorption columns, and which did not contain visible oil droplets. Fractions of HFO with high concentrations of naphthalenes, alkanes, asphaltenes, and resins were nontoxic to embryos over the range of concentrations tested. In contrast, fractions enriched with 3- to 4-ringed alkyl polycyclic aromatic hydrocarbons (PAHs) were embryotoxic, consistent with published studies of crude oils and individual alkyl PAHs. The rank order of fraction toxicity did not vary between the exposure methods and was consistent with their PAH content; fractions with higher-molecular weight alkyl PAHs were the most toxic. Exposure of juvenile trout to most fractions of HFO induced higher activities of cytochrome P450 enzymes, with a rank order of potency that varied with exposure method and differed somewhat from that of embryotoxicity. Induction reflected the bioavailability of PAHs but did not accurately predict embryotoxicity.

  15. Microscopic physical and chemical properties of graphite intercalation compounds. Final report, August 1, 1984--July 31, 1985

    Energy Technology Data Exchange (ETDEWEB)

    Eklund, P.C.

    1992-08-24

    Optical spectroscopy (Raman, FTIR and Reflection ) was used to study a variety of acceptor- and donor-type compounds synthesized to determine the microscopic models consistent with the spectrocsopic results. General finding is that the electrical conduction properties of these compounds can be understood on the basis that the intercalation of atomic and/or molecular species between the host graphite layers either raises or lowers the Fermi level (E{sub F)} in a graphitic band structure. This movement of E{sub F} is accomplished via a charge transfer of electrons from the intercalate layers to the graphitic layers (donor compounds), or vice versa (acceptor compounds). Furthermore, the band structure must be modified to take into account the layers of charge that occur as a result of the charge transfer. This charge layering introduces additional bands of states near E{sub F}, which are discussed. Charge-transfer also induces a perturbation of the graphitic normal mode frequencies which can be understood as the result of a contraction (acceptor compounds) or expansion (donor compounds) of the intralayer C-C bonds. Ab-initio calculations support this view and are in reasonable agreement with experimental data.

  16. Reference compounds for alternative test methods to indicate developmental neurotoxicity (DNT) potential of chemicals: example lists and criteria for their selection and use.

    Science.gov (United States)

    Aschner, Michael; Ceccatelli, Sandra; Daneshian, Mardas; Fritsche, Ellen; Hasiwa, Nina; Hartung, Thomas; Hogberg, Helena T; Leist, Marcel; Li, Abby; Mundi, William R; Padilla, Stephanie; Piersma, Aldert H; Bal-Price, Anna; Seiler, Andrea; Westerink, Remco H; Zimmer, Bastian; Lein, Pamela J

    2017-01-01

    There is a paucity of information concerning the developmental neurotoxicity (DNT) hazard posed by industrial and environmental chemicals. New testing approaches will most likely be based on batteries of alternative and complementary (non-animal) tests. As DNT is assumed to result from the modulation of fundamental neurodevelopmental processes (such as neuronal differentiation, precursor cell migration or neuronal network formation) by chemicals, the first generation of alternative DNT tests target these processes. The advantage of such types of assays is that they capture toxicants with multiple targets and modes-of-action. Moreover, the processes modelled by the assays can be linked to toxicity endophenotypes, i.e., alterations in neural connectivity that form the basis for neurofunctional deficits in man. The authors of this review convened in a workshop to define criteria for the selection of positive/negative controls, to prepare recommendations on their use, and to initiate the setup of a directory of reference chemicals. For initial technical optimization of tests, a set of > 50 endpoint-specific control compounds was identified. For further test development, an additional "test" set of 33 chemicals considered to act directly as bona fide DNT toxicants is proposed, and each chemical is annotated to the extent it fulfills these criteria. A tabular compilation of the original literature used to select the test set chemicals provides information on statistical procedures, and toxic/non-toxic doses (both for pups and dams). Suggestions are provided on how to use the > 100 compounds (including negative controls) compiled here to address specificity, adversity and use of alternative test systems.

  17. Anti-prion activity of a panel of aromatic chemical compounds: in vitro and in silico approaches.

    Directory of Open Access Journals (Sweden)

    Natalia C Ferreira

    Full Text Available The prion protein (PrP is implicated in the Transmissible Spongiform Encephalopathies (TSEs, which comprise a group of fatal neurodegenerative diseases affecting humans and other mammals. Conversion of cellular PrP (PrP(C into the scrapie form (PrP(Sc is the hallmark of TSEs. Once formed, PrP(Sc aggregates and catalyzes PrP(C misfolding into new PrP(Sc molecules. Although many compounds have been shown to inhibit the conversion process, so far there is no effective therapy for TSEs. Besides, most of the previously evaluated compounds failed in vivo due to poor pharmacokinetic profiles. In this work we propose a combined in vitro/in silico approach to screen for active anti-prion compounds presenting acceptable drugability and pharmacokinetic parameters. A diverse panel of aromatic compounds was screened in neuroblastoma cells persistently infected with PrP(Sc (ScN2a for their ability to inhibit PK-resistant PrP (PrP(Res accumulation. From ∼200 compounds, 47 were effective in decreasing the accumulation of PrP(Res in ScN2a cells. Pharmacokinetic and physicochemical properties were predicted in silico, allowing us to obtain estimates of relative blood brain barrier permeation and mutagenicity. MTT reduction assays showed that most of the active compounds were non cytotoxic. Compounds that cleared PrP(Res from ScN2a cells, were non-toxic in the MTT assay, and presented a good pharmacokinetic profile were investigated for their ability to inhibit aggregation of an amyloidogenic PrP peptide fragment (PrP(109-149. Molecular docking results provided structural models and binding affinities for the interaction between PrP and the most promising compounds. In summary, using this combined in vitro/in silico approach we have identified new small organic anti-scrapie compounds that decrease the accumulation of PrP(Res in ScN2a cells, inhibit the aggregation of a PrP peptide, and possess pharmacokinetic characteristics that support their drugability. These

  18. Identification of Chemical Compounds That Inhibit the Function of Glutamyl-tRNA Synthetase from Pseudomonas aeruginosa.

    Science.gov (United States)

    Hu, Yanmei; Guerrero, Edgar; Keniry, Megan; Manrrique, Joel; Bullard, James M

    2015-10-01

    Pseudomonas aeruginosa glutamyl-tRNA synthetase (GluRS) was overexpressed in Escherichia coli. Sequence analysis indicated that P. aeruginosa GluRS is a discriminating GluRS and, similar to other GluRS proteins, requires the presence of tRNA(Glu) to produce a glutamyl-AMP intermediate. Kinetic parameters for interaction with tRNA were determined and the k(cat) and KM were 0.8 s(-1) and 0.68 µM, respectively, resulting in a k(cat)/KM of 1.18 s(-1) µM(-1). A robust aminoacylation-based scintillation proximity assay (SPA) assay was developed and 800 natural products and 890 synthetic compounds were screened for inhibitory activity against P. aeruginosa GluRS. Fourteen compounds with inhibitory activity were identified. IC50s were in the low micromolar range. The minimum inhibitory concentration (MIC) was determined for each of the compounds against a panel of pathogenic bacteria. Two compounds, BT_03F04 and BT_04B09, inhibited GluRS with IC50s of 21.9 and 24.9 µM, respectively, and both exhibited promising MICs against Gram-positive bacteria. Time-kill studies indicated that one compound was bactericidal and one was bacteriostatic against Gram-positive bacteria. BT_03F04 was found to be noncompetitive with both ATP and glutamic acid, and BT_04B09 was competitive with glutamic acid but noncompetitive with ATP. The compounds were not observed to be toxic to mammalian cells in MTT assays.

  19. Changes in physico-chemical and volatile aroma compound composition of Gewürztraminer wine as a result of late and ice harvest.

    Science.gov (United States)

    Lukić, Igor; Radeka, Sanja; Grozaj, Nikola; Staver, Mario; Peršurić, Đordano

    2016-04-01

    To investigate the changes in physico-chemical and aroma composition after late and ice harvest, Gewürztraminer wines were subjected to standard, enzymatic and GC/MS analysis. Late harvest (LHGW) and ice wines (IHGW) contained more sugars, extract and volatile acidity than standard wines (SGW). IHGW had elevated glycerol and gluconic acid amounts. LHGW was richer in monoterpenol oxides, β-damascenone, 1-octen-3-ol, acetates, ethyl cinnamate and 4-vinylguaiacol than SGW. IHGW contained even higher amounts, with increased citronellol, acetaldehyde, ethyl acetate, dicarboxylic acids esters, benzenoids, furans and acetals, and reduced fermentation aroma compounds. Based on odour activity values, the strongest odorants in SGW were fruity esters. In LHGW the impact of esters increased, while in IHGW cis-rose oxide, β-damascenone and 1,1-diethoxyethane emerged as the most potent. Fruity and sweet were the dominant aroma compound series in SGW and LHGW, but in IHGW declined, while terpenic, floral, chemical, pungent and ripe fruit aroma compound series increased.

  20. Profiling of the Tox21 Chemical Collection for Mitochondrial Function: I. Compounds that Decrease Mitochondrial Membrane Potential

    Science.gov (United States)

    Mitochondrial dysfunction has been implicated in the pathogenesis of a variety of disorders including cancer, diabetes, and neurodegenerative and cardiovascular diseases. Understanding how different environmental chemicals and drug-like molecules impact mitochondrial function rep...

  1. Monitoring the Interaction of Two Heterocyclic Compounds on Carbon Steel by Electrochemical Polarization, Noise, and Quantum Chemical Studies

    Directory of Open Access Journals (Sweden)

    Vinod P. Raphael

    2016-01-01

    Full Text Available A heterocyclic phenylhydrazone 2-[(E-(2-phenylhydrazinylidenemethyl]pyridine (P2APH and its reduced form 2-[(2-phenylhydrazinylmethyl]pyridine (RP2APH were synthesized, characterized, and subjected to corrosion inhibition investigation on carbon steel (CS in 1 M HCl using gravimetric, polarization, electrochemical noise, quantum chemical, and surface studies. P2APH showed more inhibition capacity than RP2PPH. But RP2PPH was very stable in acid medium and showed pronounced corrosion inhibition efficacy for days. Energy of HOMO and LUMO, their difference, number of electrons transferred, electronegativity, chemical hardness, and so forth were evaluated by quantum chemical studies. Agreeable correlation was observed between the results of quantum chemical calculations and other corrosion monitoring techniques.

  2. Synthesis, Characterization, Crystal Structure and Quantum Chemical Calculation of Novel Compound 1,3-Dimethyl-2-ferrocenylmethylbenzimidazolium Iodide

    Institute of Scientific and Technical Information of China (English)

    ZHANG Jing; YANG Bing-Qin; ZHU Hai-Yan; LI Tao; WEN Zhen-Yi

    2006-01-01

    A novel benzimidazole derivative, 1,3-dimethyl-2-ferrocenylmethylbenzimidazolium iodide (1) was synthesized and characterized by elemental analysis, MS, 1H NMR and IR spectra. Its crystal structure was determined by X-ray single crystal diffraction, and the title compound belongs to monoclinic system with space group P2(1)/c.According to the crystal structure, the quantum chemistry calculation was performed by Gaussian 03 program, and full geometry optimizations of the title compound were carried out with DFT method at B3LYP/6-31G level. Its structure, stability, frontier molecular orbital components and net charge distribution were discussed.

  3. [Chemical characterization and quantification of fructooligosaccharides, phenolic compounds and antiradical activity of Andean roots and tubers grown in Northwest of Argentina].

    Science.gov (United States)

    Jiménez, María Eugenia; Sammán, Norma

    2014-06-01

    There is great interest in consuming foods that can provide the nutrients for a good nutrition and other health beneficial compounds. The aim of this work was to determine the chemical composition of native foods of the Andean region and to quantify some functional com-ponents. Proximal composition, vitamin C, total phenolic compounds, antiradical activity (DPPH) in peel and pulp, dietary fiber soluble and insoluble, fructooligosaccharides (FOS), total and resistant starch (in tubers and raw roots, boiled and boiled and stored) of 6 varieties of Oca (Oxalis tuberosa), 4 clones of manioc (Manihot esculenta Crantz) and yacon (Smallanthus sonchifolius were determined. The results showed greater amount of bioactive compounds and antiradical activity in the skin of these products. The highest content was found in the oca peel. In all cases, the content of insoluble fiber was greater than the soluble. The manioc had higher total starch than Andean roots and tubers. The boiling process decreased the resistant starch content of ocas and maniocs, but when these are stored for 48 h at 5 ° C, the resistant starch content increased. The FOS content of the ocas was similar for all varieties (7%). The main component of yacon carbohydrates were FOS (8.89%). The maniocs did not contain FOS. It can be concluded that the roots and tubers studied, in addition to provide nutrients, contain functional compounds that confer additional helpful value for preventing no communicable diseases.

  4. Characterization of chemical compounds for dosimetry of the radiation in industrial processes; Caracterizacao de compostos quimicos para dosimetria das radiacaoes em processos industriais

    Energy Technology Data Exchange (ETDEWEB)

    Galante, Ana Maria Sisti

    1999-07-01

    Different chemical compounds have been studied to optimize dosimetric systems in irradiation processes. In this study 2,3,5 Triphenyl -2H- Tetrazolium Chloride, Brilliant Cresyl Blue, Bromocresol Green and Potassium Nitrate were investigated for their merits or faults, for {sup 60} Co gamma field, in order to verify if can be considered as dosimeters. Fricke solution was used as reference dosimeter to determine absorption dose rates at the gamma facilities.Only Bromocresol Green and Potassium Nitrate are recommended for dosimetry purposes since the main characteristics were achieved. The other two compounds could be used in dosimetry with changes in their formulation. Bromocresol Green and potassium Nitrate are reproducible and radiation sensitive for absorbed doses from 300 Gy to 150 kGy Bromocresol Green was used in liquid form and Potassium Nitrate was prepared in solid pellets form. Spectrophotometry in the visible region was used as the main detection technique, which allows relating optical absorption, before and after irradiation, with the absorbed dose. The maximum absorption wavelength for each compound was observed at 450-460nm for bromocresol Green and 546nm for Potassium Nitrate. Dose calibration curves are linear for both compounds in all dose intervals. When irradiated with accelerated electrons, with energies between o,9 MeV and 1,5MeV, optical absorption intensification, of about 2,6 times, was observed when comparing results for Potassium Nitrate, with those for gamma rays. All the evaluations are presented in this work. (author)

  5. Chemical composition and major odor-active compounds of essential oil from PINELLIA TUBER (dried rhizome of Pinellia ternata) as crude drug.

    Science.gov (United States)

    Iwasa, Megumi; Iwasaki, Toshiki; Ono, Toshirou; Miyazawa, Mitsuo

    2014-01-01

    The chemical composition of the essential oil from PINELLIA TUBER (Japanese name: Hange), the dried rhizome of Pinellia ternata, was investigated by capillary gas chromatography (GC) and GC-mass spectrometry (MS) analyses. The oil obtained from Pinellia tuber was revealed the presence of 114 compounds, representing 90.6% of the total oil identified. This colorless oil had a spicy and woody odor. The main components of the oil were β-cubebene (8.8%), atractylon (7.8%), methyl eugenol (6.2%), and δ-cadinene (5.3%). Fifteen major odor-active compounds were identified in the essential oil from PINELLIA TUBER by the GC-olfactometry (GC-O) and aroma extract dilution analysis (AEDA). Among these, safrole (spicy) and β-vatirenene (woody) showed the highest flavor dilution (FD) factor (128), followed by paeonol (FD = 64; woody, spicy), α-humulene (FD = 64; woody), and β-phenylnaphthalene (FD = 64; spicy).

  6. Cytotoxic Activity and Chemical Composition of the Root Extract from the Mexican Species Linum scabrellum: Mechanism of Action of the Active Compound 6-Methoxypodophyllotoxin

    Science.gov (United States)

    Alejandre-García, Ivonne; Álvarez, Laura; Cardoso-Taketa, Alexandre; González-Maya, Leticia; Antúnez, Mayra; Salas-Vidal, Enrique; Díaz, J. Fernando; Marquina-Bahena, Silvia; Villarreal, María Luisa

    2015-01-01

    The cytotoxic activity and the chemical composition of the dichloromethane/methanol root extract of Linum scabrellum Planchon (Linaceae) were analyzed. Using NMR spectra and mass spectrometry analyses of the extract we identified eight main constituents: oleic acid (1), octadecenoic acid (2), stigmasterol (3), α-amyrin (4), pinoresinol (5), 6 methoxypodophyllotoxin (6), coniferin (7), and 6-methoxypodophyllotoxin-7-O-β-D-glucopyranoside (8). By using the sulforhodamine B assay, an important cytotoxic activity against four human cancer cell lines, HF6 colon (IC50 = 0.57 μg/mL), MCF7 breast (IC50 = 0.56 μg/mL), PC3 prostate (IC50 = 1.60 μg/mL), and SiHa cervical (IC50 = 1.54 μg/mL), as well as toward the normal fibroblasts line HFS-30 IC50 = 1.02 μg/mL was demonstrated. Compound 6 (6-methoxypodophyllotoxin) was responsible for the cytotoxic activity exhibiting an IC50 value range of 0.0632 to 2.7433 µg/mL against the tested cell lines. Cell cycle studies with compound 6 exhibited a cell arrest in G2/M of the prostate PC3 cancer cell line. Microtubule disruption studies demonstrated that compound 6 inhibited the polymerization of tubulin through its binding to the colchicine site (binding constant Kb = 7.6 × 106 M−1). A dose-response apoptotic effect was also observed. This work constitutes the first investigation reporting the chemical composition of L. scabrellum and the first study determining the mechanism of action of compound 6. PMID:26246833

  7. Cytotoxic Activity and Chemical Composition of the Root Extract from the Mexican Species Linum scabrellum: Mechanism of Action of the Active Compound 6-Methoxypodophyllotoxin

    Directory of Open Access Journals (Sweden)

    Ivonne Alejandre-García

    2015-01-01

    Full Text Available The cytotoxic activity and the chemical composition of the dichloromethane/methanol root extract of Linum scabrellum Planchon (Linaceae were analyzed. Using NMR spectra and mass spectrometry analyses of the extract we identified eight main constituents: oleic acid (1, octadecenoic acid (2, stigmasterol (3, α-amyrin (4, pinoresinol (5, 6 methoxypodophyllotoxin (6, coniferin (7, and 6-methoxypodophyllotoxin-7-O-β-D-glucopyranoside (8. By using the sulforhodamine B assay, an important cytotoxic activity against four human cancer cell lines, HF6 colon (IC50 = 0.57 μg/mL, MCF7 breast (IC50 = 0.56 μg/mL, PC3 prostate (IC50 = 1.60 μg/mL, and SiHa cervical (IC50 = 1.54 μg/mL, as well as toward the normal fibroblasts line HFS-30 IC50 = 1.02 μg/mL was demonstrated. Compound 6 (6-methoxypodophyllotoxin was responsible for the cytotoxic activity exhibiting an IC50 value range of 0.0632 to 2.7433 µg/mL against the tested cell lines. Cell cycle studies with compound 6 exhibited a cell arrest in G2/M of the prostate PC3 cancer cell line. Microtubule disruption studies demonstrated that compound 6 inhibited the polymerization of tubulin through its binding to the colchicine site (binding constant Kb=7.6×106 M-1. A dose-response apoptotic effect was also observed. This work constitutes the first investigation reporting the chemical composition of L. scabrellum and the first study determining the mechanism of action of compound 6.

  8. A relationship between ion balance and the chemical compounds of salt inclusions found in the Greenland Ice Core Project and Dome Fuji ice cores

    DEFF Research Database (Denmark)

    Johnsen, Sigfus Johann; Dahl-Jensen, Dorthe; Steffensen, Jørgen Peder;

    2008-01-01

    We have proposed a method of deducing the chemical compounds found in deep polar ice cores by analyzing the balance between six major ions (Cl-, NO3 -, SO4 2-, Na+, Mg2+, and Ca2+). The method is demonstrated for the Holocene and last glacial maximum regions of the Dome Fuji and GRIP ice cores...... on individual salt inclusions. The abundances in the ice cores are shown to reflect differences in climatic periods (the acidic environment of the Holocene versus the reductive environment of the last glacial maximum) and regional conditions (the marine environment of Antarctica versus the continental...

  9. Study of the Chemical Composition of the Resinous Exudate Isolated from Heliotropium Sclerocarpum and Evaluation of the Antioxidant Properties of the Phenolic Compounds and the Resin

    Directory of Open Access Journals (Sweden)

    René Torres

    2009-11-01

    Full Text Available Heliotropium sclerocarpum Phil. (Heliotropiaceae is a resinous bush that grows in the Atacama of northern Chile. The chemical composition of its resinous exudate was analyzed for the first time. One aromatic geranyl derivative: filifolinol (1, one flavanone: naringenin (2 and a new type of 3-oxo-2-arylbenzofuran derivative 3 were isolated and their structures were determined. The antioxidant activity of the phenolic compounds and resin was evaluated using the bleaching of DPPH radical method and expressed as fast reacting equivalents (FRE and total reacting equivalents (TRE.

  10. Study of the chemical composition of the resinous exudate isolated from Heliotropium sclerocarpum and evaluation of the antioxidant properties of the phenolic compounds and the resin.

    Science.gov (United States)

    Modak, Brenda; Salina, Melissa; Rodilla, Jesús; Torres, René

    2009-11-12

    Heliotropium sclerocarpum Phil. (Heliotropiaceae) is a resinous bush that grows in the Atacama of northern Chile. The chemical composition of its resinous exudate was analyzed for the first time. One aromatic geranyl derivative: filifolinol (1), one flavanone: naringenin (2) and a new type of 3-oxo-2-arylbenzofuran derivative 3 were isolated and their structures were determined. The antioxidant activity of the phenolic compounds and resin was evaluated using the bleaching of DPPH radical method and expressed as fast reacting equivalents (FRE) and total reacting equivalents (TRE).

  11. Quantum chemical studies on the inhibition potentials of some Penicillin compounds for the corrosion of mild steel in 0.1 M HCl.

    Science.gov (United States)

    Eddy, Nnabuk Okon; Ebenso, Eno E

    2010-07-01

    Inhibitive and adsorption properties of Penicillin G, Amoxicillin and Penicillin V potassium were studied using gravimetric, gasometric and quantum chemical methods. The results obtained indicate that these compounds are good adsorption inhibitors for the corrosion of mild steel in HCl solution. The adsorption of the inhibitors on mild steel surface is spontaneous, exothermic and supports the mechanism of physical adsorption. From DFT results, the sites for nucleophilic attacks in the inhibitors are the carboxylic acid functional group while the sites for electrophilic attacks are in the phenyl ring. There was a strong correlation between theoretical and experimental inhibition efficiencies.

  12. Corrosion inhibition of carbon steel pipelines by some novel Schiff base compounds during acidizing treatment of oil wells studied by electrochemical and quantum chemical methods

    Science.gov (United States)

    Abd El-Lateef, Hany M.; Abu-Dief, Ahmed M.; Mohamed, Mounir A. A.

    2017-02-01

    Three novel Schiff bases compounds were prepared and their structures were characterized by X-ray, 13C-NMR, 1H-NMR, mass, UV-Vis, FT-IR, spectral data and elemental analyses. The corrosion inhibition of the investigated inhibitors towards carbon steel in 15% HCl was investigated by using electrochemical measurements (EIS, LPR corrosion rate and Tafel plots), SEM, EDX and quantum chemical methods. The results showed that, the inhibitors are efficient mixed type corrosion inhibitors, and their inhibition performance increased with the rise of inhibitor concentration and temperature. The adsorption of the inhibitors on steel surface was found to obey Langmuir's adsorption isotherm and chemisorption. Quantum chemical calculations provide good support to empirical results.

  13. Helleborus purpurascens—Amino Acid and Peptide Analysis Linked to the Chemical and Antiproliferative Properties of the Extracted Compounds

    Directory of Open Access Journals (Sweden)

    Adina-Elena Segneanu

    2015-12-01

    Full Text Available There is a strong drive worldwide to discover and exploit the therapeutic potential of a large variety of plants. In this work, an alcoholic extract of Helleborus purpurascens (family Ranunculaceae was investigated for the identification of amino acids and peptides with putative antiproliferative effects. In our work, a separation strategy was developed using solvents of different polarity in order to obtain active compounds. Biochemical components were characterized through spectroscopic (mass spectroscopy and chromatographic techniques (RP-HPLC and GC-MS. The biological activity of the obtained fractions was investigated in terms of their antiproliferative effects on HeLa cells. Through this study, we report an efficient separation of bioactive compounds (amino acids and peptides from a plant extract dependent on solvent polarity, affording fractions with unaffected antiproliferative activities. Moreover, the two biologically tested fractions exerted a major antiproliferative effect, thereby suggesting potential anticancer therapeutic activity.

  14. Tools for Chemical Biology: New Macrocyclic Compounds from Diversity-Oriented Synthesis and Toward Materials from Silver(I) Acetylides

    DEFF Research Database (Denmark)

    Madsen, Charlotte Marie

    Part I The formation of a library of diverse macrocyclic compounds with different functionalities and ring sizes in a few steps from two easily accessible α,ω-diol building blocks is presented. The building blocks are combined by esteriffcations in four different ways leading to the formation of ...... of uoro-iodoadamantanes. However, overall the results provide a good starting point for the synthesis of new triptycene and adamantane-containing molecules that can interact with carbon nanotubes....

  15. Lattice parameters and stability of the spinel compounds in relation to the ionic radii and electronegativities of constituting chemical elements.

    Science.gov (United States)

    Brik, Mikhail G; Suchocki, Andrzej; Kamińska, Agata

    2014-05-19

    A thorough consideration of the relation between the lattice parameters of 185 binary and ternary spinel compounds, on one side, and ionic radii and electronegativities of the constituting ions, on the other side, allowed for establishing a simple empirical model and finding its linear equation, which links together the above-mentioned quantities. The derived equation gives good agreement between the experimental and modeled values of the lattice parameters in the considered group of spinels, with an average relative error of about 1% only. The proposed model was improved further by separate consideration of several groups of spinels, depending on the nature of the anion (oxygen, sulfur, selenium/tellurium, nitrogen). The developed approach can be efficiently used for prediction of lattice constants for new isostructural materials. In particular, the lattice constants of new hypothetic spinels ZnRE2O4, CdRE2S4, CdRE2Se4 (RE = rare earth elements) are predicted in the present Article. In addition, the upper and lower limits for the variation of the ionic radii, electronegativities, and their certain combinations were established, which can be considered as stability criteria for the spinel compounds. The findings of the present Article offer a systematic overview of the structural properties of spinels and can serve as helpful guides for synthesis of new spinel compounds.

  16. Gas chromatography analysis with olfactometric detection (GC-O) as a useful methodology for chemical characterization of odorous compounds.

    Science.gov (United States)

    Brattoli, Magda; Cisternino, Ezia; Dambruoso, Paolo Rosario; de Gennaro, Gianluigi; Giungato, Pasquale; Mazzone, Antonio; Palmisani, Jolanda; Tutino, Maria

    2013-12-05

    The gas chromatography-olfactometry (GC-O) technique couples traditional gas chromatographic analysis with sensory detection in order to study complex mixtures of odorous substances and to identify odor active compounds. The GC-O technique is already widely used for the evaluation of food aromas and its application in environmental fields is increasing, thus moving the odor emission assessment from the solely olfactometric evaluations to the characterization of the volatile components responsible for odor nuisance. The aim of this paper is to describe the state of the art of gas chromatography-olfactometry methodology, considering the different approaches regarding the operational conditions and the different methods for evaluating the olfactometric detection of odor compounds. The potentials of GC-O are described highlighting the improvements in this methodology relative to other conventional approaches used for odor detection, such as sensoristic, sensorial and the traditional gas chromatographic methods. The paper also provides an examination of the different fields of application of the GC-O, principally related to fragrances and food aromas, odor nuisance produced by anthropic activities and odorous compounds emitted by materials and medical applications.

  17. Gas Chromatography Analysis with Olfactometric Detection (GC-O as a Useful Methodology for Chemical Characterization of Odorous Compounds

    Directory of Open Access Journals (Sweden)

    Magda Brattoli

    2013-12-01

    Full Text Available The gas chromatography-olfactometry (GC-O technique couples traditional gas chromatographic analysis with sensory detection in order to study complex mixtures of odorous substances and to identify odor active compounds. The GC-O technique is already widely used for the evaluation of food aromas and its application in environmental fields is increasing, thus moving the odor emission assessment from the solely olfactometric evaluations to the characterization of the volatile components responsible for odor nuisance. The aim of this paper is to describe the state of the art of gas chromatography-olfactometry methodology, considering the different approaches regarding the operational conditions and the different methods for evaluating the olfactometric detection of odor compounds. The potentials of GC-O are described highlighting the improvements in this methodology relative to other conventional approaches used for odor detection, such as sensoristic, sensorial and the traditional gas chromatographic methods. The paper also provides an examination of the different fields of application of the GC-O, principally related to fragrances and food aromas, odor nuisance produced by anthropic activities and odorous compounds emitted by materials and medical applications.

  18. Variability in Human Bitter Taste Sensitivity to Chemically Diverse Compounds Can Be Accounted for by Differential TAS2R Activation.

    Science.gov (United States)

    Roura, Eugeni; Aldayyani, Asya; Thavaraj, Pridhuvi; Prakash, Sangeeta; Greenway, Delma; Thomas, Walter G; Meyerhof, Wolfgang; Roudnitzky, Natacha; Foster, Simon R

    2015-07-01

    The human population displays high variation in taste perception. Differences in individual taste sensitivity may also impact on nutrient intake and overall appetite. A well-characterized example is the variable perception of bitter compounds such as 6-n-propylthiouracil (PROP) and phenylthiocarbamide (PTC), which can be accounted for at the molecular level by polymorphic variants in the specific type 2 taste receptor (TAS2R38). This phenotypic variation has been associated with influencing dietary preference and other behaviors, although the generalization of PROP/PTC taster status as a predictor of sensitivity to other tastes is controversial. Here, we proposed that the taste sensitivities of different bitter compounds would be correlated only when they activate the same bitter taste receptor. Thirty-four volunteers were exposed to 8 bitter compounds that were selected based on their potential to activate overlapping and distinct repertoires of TAS2Rs. Taste intensity ratings were evaluated using the general Labeled Magnitude Scale. Our data demonstrate a strong interaction between the intensity for bitter substances when they activate common TAS2Rs. Consequently, PROP/PTC sensitivity was not a reliable predictor of general bitter sensitivity. In addition, our findings provide a novel framework to predict taste sensitivity based on their specific T2R activation profile.

  19. Physico-chemical parameters, bioactive compounds and microbial quality of thermo-sonicated carrot juice during storage.

    Science.gov (United States)

    Martínez-Flores, Héctor E; Garnica-Romo, Ma Guadalupe; Bermúdez-Aguirre, Daniela; Pokhrel, Prashant Raj; Barbosa-Cánovas, Gustavo V

    2015-04-01

    Thermosonication has been successfully tested in food for microbial inactivation; however, changes in bioactive compounds and shelf-life of treated products have not been thoroughly investigated. Carrot juice was thermo-sonicated (24 kHz, 120 μm amplitude) at 50 °C, 54 °C and 58 °C for 10 min (acoustic power 2204.40, 2155.72, 2181.68 mW/mL, respectively). Quality parameters and microbial growth were evaluated after processing and during storage at 4 °C. Control and sonicated treatments at 50 °C and 54 °C had 10, 12 and 14 d of shelf-life, respectively. Samples sonicated at 58 °C had the best quality; microbial growth remained low at around 3-log for mesophiles, 4.5-log for yeasts and molds and 2-log for enterobacteria after 20 d of storage. Furthermore, thermo-sonicated juice at 58 °C retained >98% of carotenoids and 100% of ascorbic acid. Phenolic compounds increased in all stored, treated juices. Thermo-sonication is therefore a promising technology for preserving the quality of carrot juice by minimising the physicochemical changes during storage, retarding microbial growth and retaining the bioactive compounds.

  20. Treatment of odorous sulphur compounds by chemical scrubbing with hydrogen peroxide--stabilisation of the scrubbing solution.

    Science.gov (United States)

    Charron, Isabelle; Couvert, Annabelle; Laplanche, Alain; Renner, Christophe; Patria, Lucie; Requieme, Benoît

    2006-12-15

    To slow down the hydrogen peroxide decomposition in basic aqueous conditions, the addition of stabilizers and co-stabilizers in the scrubbing solution was investigated. Results found with sodium silicate (Na2SiO3) were quite promising but several problems still remained. Based on these observations, this study focused on the research of a better stabilizer. Several ways were investigated: the use of silicate solutions employed in pulp industries, the addition of co-stabilizers to sodium silicate, or the use of an another stabilizer (the poly-alpha-hydroxyacrylic acid). Experiments revealed that the poly-alpha-hydroxyacrylic acid is the best stabilizing compound.

  1. Pollinia-borne chemicals that induce early postpollination effects in Dendrobium flowers move rapidly into agar blocks and include ACC and compounds with auxin activity.

    Science.gov (United States)

    Promyou, Surassawadee; Ketsa, Saichol; van Doorn, Wouter G

    2014-11-15

    The early visible effects of pollination in orchids are likely due to pollinia-borne chemicals. In Dendrobium we tested whether such compounds were water soluble and would diffuse in solid-aqueous phase, and determined both 1-aminocyclopropane-1-carboxylic acid (ACC) concentrations and auxin activity. Following pollination, the flower peduncle showed epinastic movement, followed by yellowing of the flower lip, flower senescence and ovary growth. Placing pollinia on agar blocks for 3, 6, 9 or 12h, prior to transferring them to the stigma, increased the time to these early postpollination effects or prevented them. Placing agar blocks that had been used for contact with the pollinia on the stigma also induced the early postpollination effects. The concentrations of ACC, the direct precursor of ethylene, in pollinia was lower the longer the pollinia had been in contact with the agar blocks, whilst the ACC content in the agar blocks increased with the period of contact. The auxin activity of the agar blocks also increased with the time of contact with pollinia. It is concluded that chemicals in the pollinia are responsible for the early visible postpollination effects, and that these (a) rapidly diffuse in aqueous media, and (b) comprise at least ACC and compounds with auxin activity. The idea is discussed that ACC plus auxin is adequate for the production of the early postpollination effects.

  2. Chemistry and photochemistry of 2,6-bis(2-hydroxybenzilidene)cyclohexanone. An example of a compound following the anthocyanins network of chemical reactions.

    Science.gov (United States)

    Moro, Artur J; Pana, Ana-Maria; Cseh, Liliana; Costisor, Otilia; Parola, Jorge; Cunha-Silva, L; Puttreddy, Rakesh; Rissanen, Kari; Pina, Fernando

    2014-08-14

    The kinetics and thermodynamics of the 2,6-bis(2-hydroxybenzilidene)cyclohexanone chemical reactions network was studied at different pH values using NMR, UV-vis, continuous irradiation, and flash photolysis. The chemical behavior of the system partially resembles anthocyanins and their analogue compounds. 2,6-Bis(2-hydroxybenzilidene)cyclohexanone exhibits a slow color change from yellow to red styrylflavylium under extreme acidic conditions. The rate constant for this process (5 × 10(-5) s(-1)) is pH independent and controlled by the cis-trans isomerization barrier. However, the interesting feature is the appearance of the colorless compound, 7,8-dihydro-6H-chromeno[3,2-d]xanthene, isolated from solutions of acid to neutral range, characterized by (1)H NMR and single crystal X-ray diffraction. Light absorption by 2,6-bis(2-hydroxybenzilidene)cyclohexanone solutions immediately after preparation exclusively results in cis-isomer as photoproduct, which via hemiketal formation yields (i) red styrylflavylium by dehydration under extremely acidic solutions (pH < 1) and (ii) colorless 7,8-dihydro-6H-chromeno[3,2-d]xanthene by cyclization in solutions of acid to neutral range.

  3. Spectroscopic studies of neutral and chemically oxidized species of β-carotene, lycopene and norbixin in CH{sub 2}Cl{sub 2}: Fluorescence from intermediate compounds

    Energy Technology Data Exchange (ETDEWEB)

    Alwis, D.D.D.H [Department of Chemistry, The Open University of Sri Lanka, Nawala (Sri Lanka); Department of Chemistry, University of Sri Jayewardenepura, Nugegoda (Sri Lanka); Chandrika, U.G. [Department of Biochemistry, University of Sri Jayewardenepura, Nugegoda (Sri Lanka); Jayaweera, P.M., E-mail: pradeep@sjp.ac.lk [Department of Chemistry, University of Sri Jayewardenepura, Nugegoda (Sri Lanka)

    2015-02-15

    Radical cations, dications and oxidized intermediate species of three carotenoids, namely, β-carotene, lycopene and norbixin, were generated in CH{sub 2}Cl{sub 2} solutions via chemical oxidation using anhydrous FeCl{sub 3}. UV–vis, fluorescence and fluorescence-excitation spectroscopic studies were performed to understand and compare the nature of intermediate species generated during the chemical oxidation process and subsequent degradation. The intense emission observed at 550 nm can be assigned to the S{sub 2}→S{sub 0} (1{sup 1}B{sub u}→1{sup 1}A{sub g}) transition of the carotenoid molecules. The 350 nm excitation during the oxidation process for β-carotene, lycopene and norbixin exhibit intense fluorescence peaks at 492 nm, 493 nm and 500 nm, respectively. These peaks are assigned to intermediate peroxy/epoxy compounds of the three molecules that are formed with molecular oxygen prior to the formation of oxidized short-chain stable compounds. - Highlights: • Fluorescence and UV–vis studies on β-carotene, lycopene and norbixin. • Oxidation, induced by FeCl{sub 3} in CH{sub 2}Cl{sub 2} shows blue shifted fluorescence peaks. • Fluorescence peaks were assigned to intermediate peroxy/epoxy forms of carotenoids. • The D0→D3 transition of radical cations are observed in the near IR region.

  4. In-Situ Real Time Detection of Explosive/Chemical Compounds in Mines Using Nuclear Quadrupole Resonance (NQR)

    Science.gov (United States)

    2012-02-23

    short range similar to metal detectors and ground penetrating radar systems. Although in some ways a limitation, the short range allows accurate...The QR result is orthogonal to the presently used methods of metal detection and ground penetrating radar , and therefore provides an ideal...5020 14.ABSTRACT This program was part of DARPA’s "Dog Nose" initiative to develop landmine detection technology based upon the chemical signature of

  5. Evaluation of the applicability of the Benchmark approach to existing toxicological data. Framework: Chemical compounds in the working place

    OpenAIRE

    Appel MJ; Bouman HGM; Pieters MN; Slob W; Adviescentrum voor chemische arbeidsomstandigheden (ACCA) TNO; CSR

    2001-01-01

    Five chemicals used in workplace, for which a risk assessment had already been carried out, were selected and the relevant critical studies re-analyzed by the Benchmark approach. The endpoints involved included continuous, and ordinal data. Dose-response modeling could be reasonablyapplied to the dose-response data encountered, and Critical Effect Doses (CEDs) could be derived for almost all of the endpoints considered. The resulting benchmark dose for the study as a whole was close to the NO...

  6. Assessing the distribution of volatile organic compounds using land use regression in Sarnia, "Chemical Valley", Ontario, Canada

    OpenAIRE

    Luginaah Isaac N; Atari Dominic

    2009-01-01

    Abstract Background Land use regression (LUR) modelling is proposed as a promising approach to meet some of the challenges of assessing the intra-urban spatial variability of ambient air pollutants in urban and industrial settings. However, most of the LUR models to date have focused on nitrogen oxides and particulate matter. This study aimed at developing LUR models to predict BTEX (benzene, toluene, ethylbenzene, m/p-xylene and o-xylene) concentrations in Sarnia, 'Chemical Valley', Ontario,...

  7. Correlation between chemical compounds and mechanical response in culms of two different ages of Guadua angustifolia Kunth

    OpenAIRE

    Luz Adriana Sánchez Echeverri; Giovanna Aita; Diana Robert; Mario Enrique Rodriguez Garcia

    2014-01-01

    Wet chemical analysis was used to determine carbohydrate structural contents, as well as ash and extractive contents on four Guadua Angustifolia Kunth forms ( f. Cebolla, f. Macana, f. Rayada Amarilla and f. Castilla ) with two different growth ages (young and mature). Soluble and insoluble fiber content was determined by using AOAC 985.29 method. Bending tests were conducted in a universal testing machine following ASTM D143 standard method in order to determine modulus of rupture ( MOR ). F...

  8. Negative chemical pressure effects induced by Y substitution for Ca on the `exotic' magnetic behavior of the spin-chain compound, Ca3Co2O6

    Indian Academy of Sciences (India)

    S Rayaprol; E V Sampathkumaran

    2005-09-01

    The magnetic behavior of a solid solution, Ca3-YCo2O6, based on the `exotic' spin-chain compound, Ca3Co2O6, crystallizing in K4CdCl6-derived rhombohedral structure is investigated. Among the compositions investigated ( = 0.0, 0.3, 0.5, 0.75 and 1.0), single-phase formation persists up to = 0.75, with the elongation of the -axis. The present investigations reveal that the temperature at which the `so-called' `partially disordered antiferromagnetic structure' sets in (which occurs at 24 K for the parent compound, = 0.0) undergoes gradual reduction with the substitution of Y for Ca, attaining the value of about 2.2 K for the nominal = 1.0. The trend observed in this characteristic temperature is opposite to that reported under external pressure, thereby establishing that Y substitution exerts negative chemical pressure. Anomalous steps observed in the isothermal magnetization at very low temperatures (around 2 K) for = 0.0, which have been proposed to arise from `quantum tunneling effects' are found to vanish by a small substitution ( = 0.3) of Y for Ca. Systematics in AC and DC magnetic susceptibility behavior with Y substitution for Ca have also been probed. We believe that the present results involving the expansion of chain length without disrupting the magnetic chain may be useful to the overall understanding of the novel magnetism of the parent compound.

  9. Discovery of a novel neuroprotective compound, AS1219164, by high-throughput chemical screening of a newly identified apoptotic gene marker.

    Science.gov (United States)

    Yamazaki, Takao; Muramoto, Masakazu; Okitsu, Osamu; Morikawa, Noriyuki; Kita, Yasuhiro

    2011-11-01

    We have reported that tacrolimus (FK506), an immunosuppressive drug, and diclofenac, a non-steroidal anti-inflammatory drug, possess different modes of neuroprotective action. FK506 suppresses only thapsigargin-induced apoptosis in neuroblastoma SH-SY5Y cells while diclofenac reverses tunicamycin-induced as well as thapsigargin-induced apoptosis. The aim of this study is to discover novel compounds that exert neuroprotective properties by using the transcriptional response of a newly identified gene, which was regulated by both FK506 and diclofenac, as a surrogate screening marker in high-throughput chemical screening and characterize the compounds in comparison with FK506 and diclofenac. Using a microarray with 4504 human cDNAs and quantitative RT-PCR, two genes as apoptotic markers, transmembrane protein 100 (TMEM100) and limb-bud and heart (LBH), were identified because the thapsigargin-induced elevations in their mRNA levels were reversed by both FK506 and diclofenac. A luciferase reporter assay with a TMEM100 promoter region was applied to high-throughput chemical screening. AS1219164, {3-[(E)-2-{5-[(E)-2-pyridin-4-ylvinyl]pyridin-3-yl} vinyl]aniline}, suppressed thapsigargin-induced transactivation of the TMEM100 gene and reversed thapsigargin-induced increases in TMEM100 and LBH mRNA levels in SH-SY5Y cells, similar to the effects of FK506 and diclofenac. Furthermore, AS1219164 protected against SH-SY5Y cell death induced by four apoptotic agents including thapsigargin, similar to diclofenac, but was more potent than diclofenac, while FK506 only showed protective effects against thapsigargin-induced cell death. In conclusion, a novel neuroprotecitve compound, AS1219164, was discovered by high-throughput chemical screening using a reporter assay with the TMEM100 gene promoter regulated by both FK506 and diclofenac. Reporter assay using the promoter region of a gene under pharmacological and physiological transcriptional regulation would be well suit for use

  10. Isolation, identification, and antibacterial activity of chemical compounds from ethanolic extract of suji leaf (Pleomele angusifolia NE Brown)

    Science.gov (United States)

    Faridah; Natalia; Lina, Maria; W, Hendig

    2014-03-01

    Suji (Pleomele angustifolia NE Brown) is one of the medicinal plants of the tribe of Liliaceae, empirically useful to treat coughs and respiratory diseases such as tuberculosis (TB) and pneumonia. In this study, ethanolic extract of suji leaves was tested its activity against bacteria that attacks the respiratory organs, namely Mycobacterium tuberculosis and Streptococcus pneumoniae, using a paper disc diffusion and dilution agar method. These extracts have activity in inhibiting the growth of M. tuberculosis at a concentration of 8 mg and against S. pneumoniae at a concentration of 4 mg. The fractions were tested their antibacterial activity against Streptococcus pneumoniae using paper disc diffusion method. The most active fraction was chosen based on the inhibition diameter. The fractions contained flavonoids, steroids, and essential oils. The precipitate isolated from the extraction process shows needle-shaped, white, cold and tasteless crystals. Moreover, the HPLC analysis of isolate revealed a single peak with a retention time of 7.183 minutes. The exact compounds in the isolate could not be determined but it was known the compounds contained the functional groups of alkene, alkane, C=O, -OH. Test results obtained from UV-Vis spectrophotometer provides maximum absorption at a wavelength of 203.0 nm.

  11. Chemical properties and mechanisms determining the anti-cancer action of garlic-derived organic sulfur compounds.

    Science.gov (United States)

    Cerella, Claudia; Dicato, Mario; Jacob, Claus; Diederich, Marc

    2011-03-01

    Organic sulfur compounds (OSCs) derived from plants, fungi or bacteria can serve as chemopreventive and/or chemotherapeutic agents and have been attracting medical and research interest as a promising source for novel anti-cancer agents. Garlic, which has long been used as a medicinal plant in different cultures due to its multiple beneficial effects, contains a consistent number of OSCs, the majority of which are currently under investigation for their biological activities. Experimental animal and laboratory studies have shown strong evidence that garlic OSCs may affect cancer cells by promoting early mitotic arrest followed by apoptotic cell death without affecting healthy cells. The ability of OSCs to hinder cancer cell proliferation and viability tightly correlates with the length of the sulfur chain. Current data support a mechanism of mitotic arrest of cancer cells due to the alteration of the microtubule network, possibly as a consequence of the high reactivity of sulfur atoms against the thiol groups of different cellular macromolecules controlling crucial regulatory functions. Taken together, these findings indicate a promising potential for the use of garlic-derived sulfur compounds in chemoprevention and chemotherapy.

  12. PGVL Hub: An integrated desktop tool for medicinal chemists to streamline design and synthesis of chemical libraries and singleton compounds.

    Science.gov (United States)

    Peng, Zhengwei; Yang, Bo; Mattaparti, Sarathy; Shulok, Thom; Thacher, Thomas; Kong, James; Kostrowicki, Jaroslav; Hu, Qiyue; Na, James; Zhou, Joe Zhongxiang; Klatte, David; Chao, Bo; Ito, Shogo; Clark, John; Sciammetta, Nunzio; Coner, Bob; Waller, Chris; Kuki, Atsuo

    2011-01-01

    PGVL Hub is an integrated molecular design desktop tool that has been developed and globally deployed throughout Pfizer discovery research units to streamline the design and synthesis of combinatorial libraries and singleton compounds. This tool supports various workflows for design of singletons, combinatorial libraries, and Markush exemplification. It also leverages the proprietary PGVL virtual space (which contains 10(14) molecules spanned by experimentally derived synthesis protocols and suitable reactants) for lead idea generation, lead hopping, and library design. There had been an intense focus on ease of use, good performance and robustness, and synergy with existing desktop tools such as ISIS/Draw and SpotFire. In this chapter we describe the three-tier enterprise software architecture, key data structures that enable a wide variety of design scenarios and workflows, major technical challenges encountered and solved, and lessons learned during its development and deployment throughout its production cycles. In addition, PGVL Hub represents an extendable and enabling platform to support future innovations in library and singleton compound design while being a proven channel to deliver those innovations to medicinal chemists on a global scale.

  13. The assessment of influence of different nitrogen compounds and time on germination of Lupinus angustifolius seeds and chemical composition of final products

    Directory of Open Access Journals (Sweden)

    Małgorzata Kasprowicz-Potocka

    2013-08-01

    Full Text Available The aim of the research was to determine changes in the chemical composition in lupin seeds during seed germination in a solution containing selected nitrogen compounds. Blue lupin seeds of the Neptun cultivar were germinated for 3 or 4 days in darkness, at 24°C in 1% solutions containing the following nitrogen compounds: urea, nitric acid, ammonium sulphate, methionine or yeast extract. The control consisted of seeds germinated in water. The presence of all nitrogen sources has resulted in a poorer growth of the sprouts as compared to seeds germinated in water. There was a significant increase in the true protein content as well as a significant decrease in the content of crude ash and alkaloids in the germinated seeds. The seeds germinated for 4 days had significantly higher total protein content and significantly lower content of nitrogen-free extract compounds and oligosaccharides as compared to the seeds germinated for 3 days. A significant influence of the nitrogen source on the concentration of some amino acids was found. Cystine was found to be absent in seeds germinated in the nitric acid solution, while there occurred a twofold increase in the cystine content and a fivefold increase in the methionine content in seeds germinated in the aqueous solution of methionine and an 50% increase in the cystine concentration was observed in seeds germinated in the yeast extract and ammonium sulphate solution. Methionine and cystine were the limiting amino acids in all the samples, accept of seeds germinated in the methionine solution were it was valine. Aqueous solutions of ammonium sulphate and yeast extract were found to have the most advantageous influence on the chemical composition of lupin germination products.

  14. Comparison of electron and chemical ionization modes for the quantification of thiols and oxidative compounds in white wines by gas chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Thibon, Cécile; Pons, Alexandre; Mouakka, Nadia; Redon, Pascaline; Méreau, Raphaël; Darriet, Philippe

    2015-10-09

    A rapid, sensitive method for assaying volatile impact compounds in white wine was developed using gas chromatography-tandem mass spectrometry (GC-MS/MS) technology, with a triple quadrupole analyzer operating in chemical ionization and electron impact mode. This GC-MS/MS method made it possible to assay volatile thiols (3SH: 3-sulfanylhexanol, formerly 3MH; 3SHA: 3-sulfanylhexyl acetate, formerly 3MHA; 4MSP: 4-methyl-4-sulfanylpentan-2-one, formerly 4MMP; BM: benzenemethanethiol; E2SA: ethyl 2-sulfanylacetate; and 2FM: 2-furanmethanethiol) and odoriferous oxidation markers (Sotolon: 4,5-dimethyl-3-hydroxy-2(5)H-furanone, methional, and phenylacetaldehyde) simultaneously in dry white wines, comparing electron impact (EI) and chemical ionization (CI) modes. More molecular ions were produced by CI than protonated molecules, despite the greater fragmentation caused by EI. So, even using the best reactant gas giving the highest signal for thiols, EI was the best ionization mode, with the lowest detection limits. For all compounds of interest, the limits of quantification (LOQ) obtained were well below their detection thresholds (ranging from 0.5 to 8.5ng/L for volatile thiols and 65-260ng/L for oxidation markers). Recovery rates ranged from 86% to 111%, reproducibility (in terms of relative standard deviation; RSD) was below 18% in all cases, with correlation coefficients above 0.991 for all analytes. The method was successfully applied to the analysis of compounds of interest in Sauvignon Blanc wines from a single estate and ten different vintages.

  15. Coupling physical chemical techniques with hydrotalcite-like compounds to exploit their structural features and new multifunctional hybrids with luminescent properties.

    Science.gov (United States)

    Costantino, Umberto; Costantino, Ferdinando; Elisei, Fausto; Latterini, Loredana; Nocchetti, Morena

    2013-08-28

    Hydrotalcite-like compounds (HTlc), belonging to the large class of Layered Double Hydroxides (LDH), have excited wide interest owing to the incredible number of their potential and achieved applications in physical, chemical and bio-chemical fields. This perspective review deals with recent advances in the application of physical-chemical techniques for the study of HTlc structure and for the design and synthesis, using intercalation chemistry routes, of new hybrid materials. Firstly, a rapid survey on the most common synthetic strategies for the attainment of HTlc with different crystallinity degree and crystal size and for their modification to obtain hybrids has been made, and the use of coupled techniques (XRPD, luminescence, Solid State MAS NMR and Molecular Dynamics) to gain structural information is reported. Then, the design, synthesis and photophysical characterization of azoic dyes-intercalated and co-intercalated HTlc hybrid materials are described. Hybrids constituted of ZnAl-HTlc, co-intercalated with stearate anions and methyl orange or methyl yellow dyes, have been used as nanofillers of hydrophobic polymers. The polymeric nano-composites obtained have been characterized by means of XRPD patterns, Thermo-Gravimetric Analysis and Confocal Fluorescence Microscopy. This latter technique has been found to be an excellent, complementary and non-invasive tool to probe the dispersion degree of the fluorescent fillers into the polymeric matrices and their stability in the compounding process. Finally, the synthesis and spectroscopic characterization of nanoparticle (NP) decorated HTlc for advanced antimicrobial and photo-catalytic applications are also reported. The review terminates with a concluding short note and future trends.

  16. Pathways for synthesis of new selenium-containing oxo-compounds: Chemical vapor transport reactions, hydrothermal techniques and evaporation method

    Science.gov (United States)

    Kovrugin, Vadim M.; Colmont, Marie; Siidra, Oleg I.; Gurzhiy, Vladislav V.; Krivovichev, Sergey V.; Mentré, Olivier

    2017-01-01

    Due to the low and close melting and sublimation temperatures (340 and 350 °C, respectively), the crystal growth of selenates and/or selenites is generally achieved using either chemical vapor transport routes, hydrothermal methods due to the good solubility and reactivity of (SeO3)2- anions or isothermal evaporation synthesis. Here we report examples many new crystal structures obtained using these synthesis routes. Particularly, description of each process is given with theoretical and practical information assorted with description of selected structures.

  17. Chemical characterization of essential oils from Drimys angustifolia miers (Winteraceae) and antibacterial activity of their major compounds

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Thalita G.; Dognini, Jocinei; Begnini, Ieda M.; Rebelo, Ricardo A., E-mail: ricardorebelo@furb.br [Universidade Regional de Blumenau (FURB), SC (Brazil). Dept. de Quimica; Verdi, Marcio [Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS (Brazil). Dept. de Botanica; Gasper, Andre L. de [Universidade Regional de Blumenau (FURB), SC (Brazil). Dept. de Ciencias Naturais; Dalmarco, Eduardo M. [Universidade Federal de Santa Catarina (UFSC), Florianopolis, SC (Brazil). Dept. de Analises Clinicas

    2013-01-15

    Essential oils have been extensively studied in recent years as a natural source of new antimicrobial agents. In this work, essential oils of leaf and branch from Drimys angustifolia growing in Southern Brazil were obtained by hydrodistillation and analyzed by gas chromatographies with flame ionization detector (GC-FID) and with mass spectrometer (GC-MS). Drimenol and bicyclogermacrene were isolated by column chromatography from branch and leaf essential oils, respectively. Oils, isolated compounds and combinations of them were assayed against Gram-(+) and Gram-(-) bacteria. The oils showed to be more active against Bacillus cereus, with minimum inhibitory concentration (MIC) 125 and 250 {mu}g mL{sup -1} for branch and leaf oils, respectively, strongly inhibiting bacterial growth. Bicyclogermacrene was more active then drimenol, providing a MIC value of 167 {mu}g mL-1 against B. cereus. Synergism was not observed in any of the combinations tested. (author)

  18. Assessing the Effect of Organic Compounds, Biofertilizers and Chemical Fertilizers on Morphological Properties,yield and Yield Components of Forage Sorghum (Sorghum bicolor

    Directory of Open Access Journals (Sweden)

    A.H Saeidnejad

    2012-12-01

    Full Text Available Recently, using the source of organic fertilizers and biofertilizers in sustainable crop production is growing. In order to evaluate the effect of organic compounds, biofertilizers and chemical fertilizer on morphological properties, yield and yield components of forage Sorghum (sorghum bicolor a field experiment was conducted in the Research Farm, College of Agriculture, Ferdowsi University of Mashhad in 2008.The treatments were seed inoculation with the combination of Azotobacter chroococcum and Azospirillum brasilense, Compost (15 t/ha, Vermicompost (10 t/ha, seed inoculation with Azotobacter and Azospirillum and compost (10t/ha, seed inoculation with Azotobacter chroococcum and Azospirillum brasilense and Vermicompost (7t/ha, seed inoculation with Pseudomonas flurescence, seed inoculation with Pseudomonas flurescence and Azotobacter chroococcum and Azospirillum brasilense combination, seed inoculation with Pseudomonas flurescence and compost (15t/ha, chemical fertilizer (80 kg/h urea fertilizer and 50 kg/h super phosphate fertilizer and control. Harvesting was performed in 2 cuts in flowering stage. Plant height, number of tiller per plant and SPAD reading was significantly affected by the treatments. Stem diameter was not affected by any treatments. There was a significant difference among all treatments in terms of fresh and dry forage yield. There were no significant differences among all treatments in terms of stem and leaf dry matter. In general, result of this experiment indicated that organic amendments and biofertilizers could be acceptable alternatives for chemical fertilizers.

  19. Propolis Standardized Extract (EPP-AF®, an Innovative Chemically and Biologically Reproducible Pharmaceutical Compound for Treating Wounds

    Directory of Open Access Journals (Sweden)

    Andresa Aparecida Berretta, Andresa Piacezzi Nascimento, Paula Carolina Pires Bueno, Mirela Mara de Oliveira Lima Leite Vaz, Juliana Maldonado Marchetti

    2012-01-01

    Full Text Available The aim of this study was to develop a formulation, containing the propolis standardized extract (EPP-AF®, which can assist in the healing of skin lesions. To achieve this objective the antimicrobial activity and chemical composition of the propolis extract was determined. The final product was subjected to in vitro and in vivo pre-clinical evaluation. The broth macrodilution method was used to determine the antimicrobial activity of the extracts and formulations against the microorganisms most commonly found in burns, Pseudomonas aeruginosa, Klebsiella pneumoniae, Escherichia coli, Staphylococcus aureus and Staphylococcus epidermidis. Wistar rats with puncture wounded skin were used to evaluate the wound healing properties of propolis. The results of chemical and biological characterization demonstrated the batch-to-batch reproducibility of the standardized extract which is an unprecedented result. The antimicrobial and wound healing activity of the pharmaceutical studied showed the best results when samples contain 3.6% propolis, suggesting that this is the most promising composition.

  20. A rapid dissolution procedure to aid initial nuclear forensics investigations of chemically refractory compounds and particles prior to gamma spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Reading, David G., E-mail: d.reading@noc.soton.ac.uk [GAU-Radioanalytical Laboratories, Ocean and Earth Science, University of Southampton, National Oceanography Centre, European Way, Southampton SO14 3ZH (United Kingdom); Croudace, Ian W.; Warwick, Phillip E. [GAU-Radioanalytical Laboratories, Ocean and Earth Science, University of Southampton, National Oceanography Centre, European Way, Southampton SO14 3ZH (United Kingdom); Britton, Richard [AWE plc, Aldermaston, Reading, Berkshire, RG7 4PR (United Kingdom)

    2015-11-05

    A rapid and effective preparative procedure has been evaluated for the accurate determination of low-energy (40–200 keV) gamma-emitting radionuclides ({sup 210}Pb, {sup 234}Th, {sup 226}Ra, {sup 235}U) in uranium ores and uranium ore concentrates (UOCs) using high-resolution gamma ray spectrometry. The measurement of low-energy gamma photons is complicated in heterogeneous samples containing high-density mineral phases and in such situations activity concentrations will be underestimated. This is because attenuation corrections, calculated based on sample mean density, do not properly correct where dense grains are dispersed within a less dense matrix (analogous to a nugget effect). The current method overcomes these problems using a lithium tetraborate fusion that readily dissolves all components including high-density, self-attenuating minerals/compounds. This is the ideal method for dissolving complex, non-volatile components in soils, rocks, mineral concentrates, and other materials where density reduction is required. Lithium borate fusion avoids the need for theoretical efficiency corrections or measurement of matrix matched calibration standards. The resulting homogeneous quenched glass produced can be quickly dissolved in nitric acid producing low-density solutions that can be counted by gamma spectrometry. The effectiveness of the technique is demonstrated using uranium-bearing Certified Reference Materials and provides accurate activity concentration determinations compared to the underestimated activity concentrations derived from direct measurements of a bulk sample. The procedure offers an effective solution for initial nuclear forensic studies where complex refractory minerals or matrices exist. It is also significantly faster, safer and simpler than alternative approaches. - Highlights: • Low energy gamma photons (<200 keV) are attenuated in U-bearing compounds. • Corrections based on bulk density do not yield accurate activity

  1. Organic honey from Trás-Os-Montes region (Portugal): chemical, palynological, microbiological and bioactive compounds characterization.

    Science.gov (United States)

    Estevinho, Leticia M; Feás, Xesús; Seijas, Julio A; Pilar Vázquez-Tato, M

    2012-02-01

    At the present time, the quality, integrity, sanitation and nutritional value of honeys receive attention on an international level due to the increasing content of chemicals in the aforementioned matrix. This work was conducted to evaluate the quality of 75 organic honey samples from the Trás-Os-Montes region (Portugal). Mean values obtained for physico-chemical parameters were: pH 3.7; 15.6% moisture; 0.26mS/cm electrical conductivity; 0.25% ash; 1.1mg/kg HMF; 15.3 Gothe diastase activity; 40.3meq/kg free acidity; 67.8% invert sugars and 2.7% apparent sucrose. All honey samples can be classified as monofloral Erica sp., as showed by pollen features. The amounts of phenols and flavonoids in the samples were also determined. In respect to sanitary quality (fecal coliforms) and safety (sulfite-reducing clostridia and Salmonella), all organic honey samples were negative. Furthermore, yeast and molds were detected in low counts, with mean values obtained of 5.5cfu/g and the value of total aerobic mesophiles obtained from honeys was established in 1.3×10(2)cfu/g±7.5×10(1)cfu/g. The levels of flavonoids had a stronger impact on both mesophiles (p=0.0004) and molds (p=0.0138) than the sucrose concentration (p=0.001 and 0.0278; respectively). The results reported in this study should be introduced in the organic honey label, and may help beekeepers, the industry, researchers and consumers better understand honey properties.

  2. Chemical characteristics of water-soluble organic compounds (WSOC) in PM2.5 in Beijing, China: 2011-2012

    Science.gov (United States)

    Xiang, Ping; Zhou, Xueming; Duan, Jinchun; Tan, Jihua; He, Kebin; Yuan, Cheng; Ma, Yongliang; Zhang, Yuanxun

    2017-01-01

    PM2.5 filter sampling was conducted on a daily basis for one year from 2011 to 2012 at an urban site in Beijing. One-third of the samples were subjected to chemical analysis, including water-soluble inorganic ions, organic carbon (OC), elemental carbon (EC) and water-soluble organic carbon (WSOC). The results show that OM (Organic Matter = OC × 1.6; average 50.8% of PM2.5) was the most abundant species, followed by SNA (SO42 - + NO3- + NH4+; average 35%); however, SNA contributed more to PM2.5 in summer and OM contributed more in other seasons. The concentrations of nitrate were higher in summer and autumn than that in winter, suggesting that nitrate had formed in acidic and ammonium-poor environments in summer. WSOC accounted for 26.6% of OC and 8.1% of PM2.5 and exhibited distinct seasonal variations: the lowest concentration occurred in spring (3.90 ± 1.78 μg/m3) and the highest in autumn (5.82 ± 3.73 μg/m3). The higher WSOC/OC ratio in summer suggests that OC was more aged, oxidized and hygroscopic during this season. The seasonal trend of SOC (Secondary Organic Carbon) was the opposite of WSOC/OC, which may indicate that the OC/EC minimum ratio method was not suitable for estimating SOC in this study. Correlations between WSOC and K+, EC and inorganic ions indicated that WSOC was dominated by secondary formation, except that biomass burning was an important source in autumn. Aqueous chemical processes may play an important role in the formation of WSOC in winter. Meteorological conditions had an important influence on WSOC: positive correlations were observed between WSOC and relative humidity, but there was a negative correlation when humidity was higher than 80% in summer.

  3. Production, chemical composition and stocking rate of forage systems compounds for coastcross-1 intercropped with ryegrass and clovers

    Directory of Open Access Journals (Sweden)

    Michelle Schalemberg Diehl

    2014-10-01

    Full Text Available The objective of this research was to evaluate the forage production, crude protein and neutral detergent fiber level, stocking rate of three forage systems compounds for Coastcross-1 (Cynodon dactylon L. Pers. + ryegrass (Lolium multiflorum Lam., cv. Comum; Coastcross-1 + ryegrass + red clover (Trifolium pratense L., cv. Estanzuela 116 and Coastcross-1 + ryegrass + white clover (Trifolium repens L., cv. Yi. The experiment was carried out from April 2007 to April 2008, for 11 grazing cycles, six in winter season and five in summer season. Holstein cows receiving 0.9% of body weight/day feed supplement concentrate were used. The herbage mass of pre and post-grazing, botanical and morphological composition crude protein and neutral detergent fiber level were evaluated. A randomized complete design was used with three treatments (forage systems two replications (paddocks and independent evaluations (grazing cycles. Superior value (P<0.05 of forage production and daily dry matter accumulation rate were found in winter season for the forage systems with legume. No differences in dry matter disappearance rate and stocking rate averages were detected among pastures. Residual effects of red clover were observed on Coastcross-1 + ryegrass with superior result (P<0.05 on crude protein and lower neutral detergent fiber level.

  4. Phytochemical and physical-chemical analysis of Polish willow (Salix spp.) honey: identification of the marker compounds.

    Science.gov (United States)

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

    2014-02-15

    The case study of Polish Salix spp. honey was compared with published data on willow honey from other regions. GC-FID/MS (after HS-SPME and ultrasonic solvent extraction) and targeted HPLC-DAD were applied. Phenolic content, FRAP/DPPH assays and the colour coordinates were determined spectrophotometrically. Beside ubiquitous linalool derivatives, borneol (up to 10.9%), bicyclic monoterpenes with pinane skeleton (pinocarvone up to 10.6%, myrtenal up to 4.8% and verbenone up to 3.4%) and trans-β-damascenone (up to 13.0%) dominated in the headspace. The main compounds of the extractives were vomifoliol (up to 39.6%) and methyl syringate (up to 16.5%) along with not common 4-hydroxy-3-(1-methylethyl)benzaldehyde (up to 11.1%). Abscisic acid (ABA) was found (up to 53.7 mg/kg) with the isomeric ratio (Z,E)-ABA:(E,E)-ABA=1:2. The honey exhibited low antioxidant potential with pale yellow colour. The composition of Polish willow honey is similar to Mediterranean willow honeys with several relevant differences.

  5. Mapping chemical disorder and ferroelectric distortions in the double perovskite compound Sr 2-x Gd x MnTiO6 by atomic resolution electron microscopy and spectroscopy.

    Science.gov (United States)

    Biškup, Neven; Álvarez-Serrano, Inmaculada; Veiga, Maria; Rivera-Calzada, Alberto; Garcia-Hernandez, Mar; Pennycook, Stephen J; Varela, Maria

    2014-06-01

    In this work we report a study of the chemical and structural order of the double perovskite compound Sr 2-x Gd x MnTiO6 for compositions x=0, 0.25, 0.5, 0.75, and 1. A noticeable disorder at the B-site in the Mn and Ti sublattice is detected at the atomic scale by electron energy-loss spectroscopy for all x values, resulting in Mn-rich and Ti-rich regions. For x ≥ 0.75, the cubic unit cell doubles and lowers its symmetry because of structural rearrangements associated with a giant ferroelectric displacement of the perovskite B-site cation. We discuss this finding in the light of the large electroresistance observed in Sr 2-x Gd x MnTiO6, x ≥ 0.75.

  6. Effects of various chemical compounds on spontaneous and hydrogen peroxide-induced reversion in strain TA104 of Salmonella typhimurium.

    Science.gov (United States)

    Han, J S

    1992-04-01

    In experiments designed to determine which active oxygen species contribute to hydrogen peroxide (HP)-induced reversion in strain TA104 of Salmonella typhimurium, 1,10-phenanthroline (an iron chelator, which prevents the formation of hydroxyl radicals from HP and DNA-bound iron by the Fenton reaction), sodium azide (a singlet oxygen scavenger), and potassium iodide (an hydroxyl radical scavenger) inhibited HP-induced reversion. These results indicate that hydroxyl radicals generated from HP by the Fenton reaction, and perhaps singlet oxygen, contribute to HP-induced reversion in TA104. However, reduced glutathione (reduces Fe3+ to Fe2+ and/or HP to water), diethyldithiocarbamic acid (an inhibitor of superoxide dismutase), diethyl maleate (a glutathione scavenger), and 3-amino-1,2,4-triazole (an inhibitor of catalase) did not inhibit HP-induced reversion in TA104. Thus, superoxide radical anions and HP itself do not appear to be the cause of HP-induced reversion in this strain. In experiments on the effect of 5 common dietary compounds (beta-carotene, retinoic acid, and vitamins A, C and E), chlorophyllin (CHL), and ergothioneine, the frequency of revertants in TA104 increased above the spontaneous frequency in the presence of beta-carotene or vitamin C (about 2-fold) or vitamin A (about 3-fold). The 5 dietary antimutagens and CHL did not inhibit HP-induced reversion in TA104. However, L-ergothioneine inhibited HP-induced reversion in this strain. Therefore, it is likely that L-ergothioneine is a scavenger of hydroxyl radicals or an inhibitor of their formation, and perhaps of singlet oxygen, at the concentrations tested in TA104.

  7. Influence of Ni content on physico-chemical characteristics of Ni, Mg, Al-Hydrotalcite like compounds

    Directory of Open Access Journals (Sweden)

    Alexandre Carlos Camacho Rodrigues

    2003-12-01

    Full Text Available The physico-chemical properties of a series of Ni,Mg,Al-HTLC with Al/(Al+Mg+Ni = 0.25 and low Ni/Mg ratios were studied by means of X-ray diffraction (XRD, thermogravimetric (TGA and thermodifferential (DTA analysis, N2 physissorption and temperature programmed reduction (TPR. The as-synthesized materials were well-crystallized, with XRD patterns typical of the HTLCs in carbonate form. Upon calcination and dehydration the dehydroxilation of the layers with concurrent decomposition of carbonate anions produced mixed oxides with high surface area. XRD analysis indicated that the different nickel and aluminum oxides species are well-dispersed in a poor-crystallized MgO periclase-type phase. As observed by TPR, the different Ni species showed distinct interactions with Mg(AlO phase, which were influenced by both nickel content and calcination temperature. Regardless of the the nickel content, the reduction of nickel species was not complete as indicated by the presence of metallic dispersions.

  8. Magnetovolume and chemical bonding effects of Sn atom in the γ'-(Fe1-xSnx)4N compounds

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Combining x-ray diffraction and high pressure Mossbauer spectroscopy,the structure and the hyperfine parameters of Sn substituted for Fe in γ'-Fe4N were in-vestigated. The results of x-ray diffraction indicate that single phase γ'-(Fel-xSnx)4Ncompounds can be synthesized in the composition range 0≤ x ≤ 0.3, and the latticeparameter can be well fitted with two linear formulas α0(x) = 3.795 + 0.019 × x (0.0≤x ≤0.10) and α0(x) = 3.795+ 0.228 × (x- 0.1)(0.10 ≤ x ≤0.30) for different contentof Sn. Using high pressure Mossbauer spectra, the influences of the magnetovolunceffect and the chemical bonding effect of Sn atom on the hyperfine magnetic field andthe isomer shift were first distinguished. It is found that the magnetovolume and thechemical bonding have different influences on the properties of γ'-(Fe1-xSnx)4N, andthe latter plays a more important role.

  9. Discrimination of Chinese teas with different fermentation degrees by stepwise linear discriminant analysis (S-LDA) of the chemical compounds.

    Science.gov (United States)

    Wu, Quan-Jin; Dong, Qing-Hua; Sun, Wei-Jiang; Huang, Yan; Wang, Qiong-Qiong; Zhou, Wei-Long

    2014-09-24

    This study aimed to construct objective and accurate analytical models of tea categories based on their polyphenols and caffeine. A total of 522 tea samples of 4 commonly consumed teas with different fermentation degrees (green tea, white tea, oolong tea, and black tea) were analyzed by high-performance liquid chromatography (HPLC) coupled with spectrophotometry, utilizing ISO 14502, as analytical tools. The content of polyphenols and caffeine varied significantly according to differently fermented teas, indicating that these active constituents may discriminate fermentation degrees effectively. By principal component analysis (PCA) and stepwise linear discriminant analysis (S-LDA), the vast majority of tea samples could be successfully differentiated according to their chemical markers. This study yielded three discriminant functions with the capacity to simultaneously discriminate the four tea categories with a 97.8% correct rate. In classification of oolong and other teas, there were one discriminant function and two equations with best discriminant capacity. Furthermore, the classification of different degrees of fermentation of oolong and external validation achieved the desired results. It is suggested that polyphenols and caffeine are the distinct variables to establish internationally recognized models of teas.

  10. Technical Note: Performance of Chemical Ionization Reaction Time-of-Flight Mass Spectrometry (CIR-TOF-MS for the measurement of atmospherically significant oxygenated volatile organic compounds

    Directory of Open Access Journals (Sweden)

    K. P. Wyche

    2007-01-01

    Full Text Available The performance of a new chemical ionization reaction time-of-flight mass spectrometer (CIR-TOF-MS utilising the environment chamber SAPHIR (Simulation of Atmospheric Photochemistry In a large Reaction Chamber- Forschungzentrum Jülich, Germany is described. The work took place as part of the ACCENT (Atmospheric Composition and Change the European NeTwork for excellence supported oxygenated volatile organic compound (OVOC measurement intercomparison during January 2005. The experiment entailed the measurement of 14 different atmospherically significant OVOCs at various mixing ratios in the approximate range 10.0–0.6 ppbV. The CIR-TOF-MS operated throughout the exercise with the hydronium ion (H3O+ as the primary chemical ionization (CI reagent in order to facilitate proton transfer to the analyte OVOCs. The results presented show that the CIR time-of-flight mass spectrometer is capable of detecting a wide range of atmospheric OVOCs at mixing ratios of around 10 ppbV in "real-time" (i.e. detection on the one-minute time scale, with sub-ppbV measurement also achieved following an increase in averaging time to tens of minutes. It is shown that in general OVOC measurement is made with high accuracy and precision, with integration time, mixing ratio and compound dependent values as good as 4–13% and 3–15% respectively. It is demonstrated that CIR-TOF-MS has rapid multi-channel response at the required sensitivity, accuracy and precision for atmospheric OVOC measurement.

  11. Chemical composition and bioactive compounds of grape pomace (Vitis vinifera L., Benitaka variety, grown in the semiarid region of Northeast Brazil

    Directory of Open Access Journals (Sweden)

    Eldina Castro Sousa

    2014-03-01

    Full Text Available Grape pomace (Vitis vinifera L., Benitaka variety, grown in the semiarid region of Northeast Brazil was evaluated in relation to chemical composition, and content of minerals and functional properties. Its microbiological quality and toxic potential, using Artemia salina sp, were also investigated. The results showed that the flour obtained from these residues had below neutral pH (3.82, moisture (3.33g/100g, acidity of (0.64g of citric acid/100g, and ash (4.65 g/100g. The amount of total dietary fiber (46.17g/100g stood out quantitatively compared to the content of carbohydrate (29.2g/100 g, protein (8.49g/100g, and lipids (8.16g/100g. The total energy was 224Kcal/100g. With regard to the compounds with functional properties, higher values of insoluble fiber 79% (36.4 g/100 g; vitamin C (26.25 mg of acid ascorbic/100g, and anthocyanins (131mg/100g were found. The minerals iron, potassium, zinc, manganese, and calcium were present in higher concentrations. There were no significant copper values. The results showed that the grape residues are an important source of nutrients and compounds with functional properties suggesting that they can be incorporated as an ingredient in the diet and/or used as a dietary supplement aiming at health benefits. The residues did not show microbiological contamination and were considered nontoxic.

  12. Superoxide dismutases and glutaredoxins have a distinct role in the response of Candida albicans to oxidative stress generated by the chemical compounds menadione and diamide

    Directory of Open Access Journals (Sweden)

    Guilherme Maranhão Chaves

    2012-12-01

    Full Text Available To cope with oxidative stress, Candida albicans possesses several enzymes involved in a number of biological processes, including superoxide dismutases (Sods and glutaredoxins (Grxs. The resistance of C. albicans to reactive oxygen species is thought to act as a virulence factor. Genes such as SOD1 and GRX2, which encode for a Sod and Grx, respectively, in C. albicans are widely recognised to be important for pathogenesis. We generated a double mutant, Δgrx2/sod1, for both genes. This strain is very defective in hyphae formation and is susceptible to killing by neutrophils. When exposed to two compounds that generate reactive oxygen species, the double null mutant was susceptible to menadione and resistant to diamide. The reintegration of the SOD1 gene in the null mutant led to recovery in resistance to menadione, whereas reintegration of the GRX2 gene made the null mutant sensitive to diamide. Despite having two different roles in the responses to oxidative stress generated by chemical compounds, GRX2 and SOD1 are important for C. albicans pathogenesis because the double mutant Δgrx2/sod1 was very susceptible to neutrophil killing and was defective in hyphae formation in addition to having a lower virulence in an animal model of systemic infection.

  13. Growth of AlGaSb Compound Semiconductors on GaAs Substrate by Metalorganic Chemical Vapour Deposition

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    A. H. Ramelan

    2010-01-01

    Full Text Available Epitaxial AlxGa1-xSb layers on GaAs substrate have been grown by atmospheric pressure metalorganic chemical vapour deposition using TMAl, TMGa, and TMSb. We report the effect of V/III flux ratio and growth temperature on growth rate, surface morphology, electrical properties, and composition analysis. A growth rate activation energy of 0.73 eV was found. For layers grown on GaAs at 580∘C and 600∘C with a V/III ratio of 3 a high quality surface morphology is typical, with a mirror-like surface and good composition control. It was found that a suitable growth temperature and V/III flux ratio was beneficial for producing good AlGaSb layers. Undoped AlGaSb grown at 580∘C with a V/III flux ratio of 3 at the rate of 3.5 μm/hour shows p-type conductivity with smooth surface morphology and its hole mobility and carrier concentration are equal to 237 cm2/V.s and 4.6 × 1017 cm-3, respectively, at 77 K. The net hole concentration of unintentionally doped AlGaSb was found to be significantly decreased with the increased of aluminium concentration. All samples investigated show oxide layers (Al2O3, Sb2O3, and Ga2O5 on their surfaces. In particular the percentage of aluminium-oxide was very high compared with a small percentage of AlSb. Carbon content on the surface was also very high.

  14. Investigation on antimicrobial effects of essential oil of purple coneflower (Echinacea purpurea L. and identification of its chemical compounds

    Directory of Open Access Journals (Sweden)

    Zahra Izadi

    2014-04-01

    Full Text Available Background: Purple coneflower (Echinaceae purpurea L. is a perennial herbaceous with astringent properties, disinfectant, antimicrobial and anti intoxication activity. The main objective of this study was to evaluate the antimicrobial activity of shoot essential oil of purple coneflower against some microorganisms including gram positive, gram negative bacteria, filamentous fungi and yeasts. Material and Methods: In this experimental and laboratory investigation, plant samples were collected in full blooming stage. Shoot essential oil was extracted by hydro-distillation technique using Clevenger apparatus. The chemical constitutes of this oil was analyzed by GC and GC/MS method. Anti microbial properties of the essential oil were determined using micro broth dilution and well disk diffusion methods. At the end, data were analyzed by the SPSS version 15 software, using the T-test and Duncan s' test. Results: Twenty nine components were identified by GC and GC/MS in the essential oil of purple coneflower representing 96.21% of total oil. The major components were Germacrene D (53.30%, -Cymene (9.78%, β-Caryophyllene (7.52%, α-Humulene (5.22%, β-Bisabolene (4.43% and α-Pinene (4.23%, respectively. This oil exhibited strong antifungal activity against filamentous fungi and yeast with average of inhibition zone (AIZ 39.63. Microorganisms differ in their resistance to purple coneflower oil. All of the bacteria including gram positive and gram negative bacteria are more resistant than fungi and gram negative bacteria are more resistant than gram positive bacteria. Pseudomonas aeruginosa and Salmonella typhimurium were more resistant than others. Conclusion: The results of this study showed that coneflower essential oil with significant antimicrobial effects and can be used instead of synthetic antibiotics that microbial resistance towards them is increasing.

  15. Free variable selection QSPR study to predict (19)F chemical shifts of some fluorinated organic compounds using Random Forest and RBF-PLS methods.

    Science.gov (United States)

    Goudarzi, Nasser

    2016-04-05

    In this work, two new and powerful chemometrics methods are applied for the modeling and prediction of the (19)F chemical shift values of some fluorinated organic compounds. The radial basis function-partial least square (RBF-PLS) and random forest (RF) are employed to construct the models to predict the (19)F chemical shifts. In this study, we didn't used from any variable selection method and RF method can be used as variable selection and modeling technique. Effects of the important parameters affecting the ability of the RF prediction power such as the number of trees (nt) and the number of randomly selected variables to split each node (m) were investigated. The root-mean-square errors of prediction (RMSEP) for the training set and the prediction set for the RBF-PLS and RF models were 44.70, 23.86, 29.77, and 23.69, respectively. Also, the correlation coefficients of the prediction set for the RBF-PLS and RF models were 0.8684 and 0.9313, respectively. The results obtained reveal that the RF model can be used as a powerful chemometrics tool for the quantitative structure-property relationship (QSPR) studies.

  16. A theoretical analysis of the extraction of heterocyclic organic compounds from an organic phase using chemically mediated electrochemically modulated complexation in ion exchange polymer beads

    Energy Technology Data Exchange (ETDEWEB)

    Ozekin, K.; Noble, R.D.; Koval, C.A.

    1991-01-01

    A cyclical electrochemical process for the removal of heterocyclic organic compounds (pollutants) from an organic solvent using an ion-exchange polymer is analyzed. In this analysis, there are three main steps: In the first step, the polymer beads containing the active form of the complexing agent are contacted with the contaminated (feed) hydrocarbon phase. The pollutant diffuses into the beads and binds with the complexing agent which is in the reduced state. It is a fast reversible reaction. For the second step, the beads which contain a pollutant are contacted with a waste (receiving) phase and a chemical mediator is then used to oxidize the complexing agent and to reduce its affinity towards the pollutant so that it can be released. The oxidation of the complexing agent is an irreversible reaction. This is a moving boundary problem with countercurrent diffusion. For each mole of mediator that goes into the bead, one mole of pollutant exits since each complexing agent binds one pollutant. In the third step, the waste hydrocarbon phase is removed and a second chemical mediator is then used to reduce the complexing agent. The reduction of the complexing agent is also an irreversible reaction. Partial differential equations are used to analyze this process. 26 refs., 9 figs.

  17. Magnetovolume and chemical bonding effects of Ni atom in γ’-(Fe1-xNix)4N compounds

    Institute of Scientific and Technical Information of China (English)

    薛德胜; 李发伸

    1997-01-01

    By X-ray diffraction and high pressure Mossbauer spectroscopy, the structure and the hyperfine parameters of Ni substituted γ-Fe4N were investigated. The results of X-ray diffraction indicate that single phase γ’-(Fe1-xNix)4N compounds can be prepared in the composition range of 0≤x≤0.6, and with the increase of Ni content the lattice parameter is fit for the relationship a0(x) = 3.790 5-0.021 57x-0.031 67x2. By high pressure Mossbauer spectra, effects of magnetovolume and chemical bonding of Ni atom on hyperfine magnetic field and isomer shift of iron were distinguished for the first time, and their composition dependences for different lattice sites were studied simultaneously. It is found that the magnetovolume and chemical bonding have different influences on the properties of γ’-(Fe1-xNix)4N, and the latter one plays a key role in the property changes of γ-(Fe1-xNix)4N.

  18. Clinical Study of Drug-resistant Pulmonary Tuberculosis Treated by Combination of Anti-Tuberculosis Chemicals and Compound Astragalus Capsule(复方黄芪胶囊)

    Institute of Scientific and Technical Information of China (English)

    姜艳; 李新; 于志勇; 尹红义; 韩玉庆

    2004-01-01

    Objective: To observe and evaluate the therapeutic effect of anti-tuberculosis (anti-TB) chemicals and Compound Astragalus Capsule (CAC) in combinedly treating drug resistant pulmonary tuberculosis (DR-TB). Methods: Ninety-two patients with DR-TB were equally randomized into the treated group (treated with combination therapy) and the control group (treated with anti-TB chemicals alone). The therapeutic course for both groups was 18 months. Therapeutic effects between the two groups were compared at the end of the therapeutic course. Sputum bacterial negative rate, focal absorption effective rate, cavity closing rate, 10-day symptom improving rate, the incidence of adverse reaction and 2-year bacteriological recurrence rate between the two groups were compared. Results: In the treated group, the sputum bacterial negative conversion rate was 84. 8%, focal absorption effective rate 91.3 %, cavity closing rate 58. 7 % and 10-day symptom improving rate 54.4%, while in the control group, the corresponding rates were 65.2%,73.9 %, 37. 0% and 26.1%, respectively. Comparison between the groups showed significant difference in all the parameters ( P<0.05, P<0.05, P<0.05 and P<0.01 ). The incidence of adverse reaction and 2year bacteriological recurrence rate in the treated group were 23.9 % and 2.6 % respectively, while those in the control group 50.0% and 16.7%, which were higher than the former group with significant difference ( P<0.01 and P<0.05, respectively). Conclusion: The therapeutic effect of combined treatment with antiTB and CAC is superior to that of treatment with anti-TB chemicals alone, and the Chinese herbal medicine showed an adverse reaction alleviating effect, which provides a new therapy for DR-TB, and therefore, it is worth spreading in clinical practice.

  19. Impact of Using a High Surface Area Solid Phase Micro Extraction Device and Fast Gas Chromatography Heating Rates in the Sampling and Analysis of Trace Level Chemical Warfare Agents and CWA-Like Compounds

    Science.gov (United States)

    2009-09-21

    rest of the inner diameter of the column is filled with inert carrier gas (the mobile phase), often helium or hydrogen . Chemical compounds are...Sample of Liquid CWA-Degradation Product The VX degradation compound, 2-(diisopropylaminoethyl)ethyl sulfide (2-DES) was diluted in methylene chloride...demonstrated separation of CWA mixture components ranging in molecular weight from m/z 140 (sarin) to 466 (T2 toxin ) with a field-portable GC/MS system

  20. THE RELATION OF CHEMICAL STRUCTURE IN CATECHOL COMPOUNDS AND DERIVATIVES TO POISON IVY HYPERSENSITIVENESS IN MAN AS SHOWN BY THE PATCH TEST.

    Science.gov (United States)

    Keil, H; Wasserman, D; Dawson, C R

    1944-10-01

    1. Additional evidence is presented in support of the view which postulates a close chemical and biologic relation between the active ingredients in poison ivy and Japan lac. 2. Biologic evidence, based on the use of the patch test in man, is presented in support of the view that the active ingredient in poison ivy is a catechol derivative with a long, unsaturated side-chain in the 3-position. 3. Of the catechol compounds and derivatives studied, group reactions in patients sensitive to poison ivy leaves or extract were exhibited by the following compounds: 3-pentadecyl catechol (100 per cent of 21 cases), 4-pentadecyl catechol (38 per cent of 21 cases), "urushiol" dimethyl ether (33 per cent of 33 cases), 3-pentadecenyl-1'-veratrole (21 per cent of 14 cases), 3-methyl catechol (14 per cent of 21 cases), and hydrourushiol dimethyl ether (10 per cent of 20 cases). It has been found that 3-geranyl catechol shows a practically constant group reactivity in persons sensitive to poison ivy. 4. The uniformly positive group reaction to 3-pentadecyl catechol is notable since this substance possesses a saturated side-chain, whereas the active ingredient in poison ivy is known to have an unsaturated side-chain. 5. The group reactivity was not restricted to the 3-position, for in some instances 4-pentadecyl catechol also gave group reactions which, however, were less intense and less frequent than those shown by 3-pentadecyl catechol. This indicates that in some cases a long side-chain in the 4 position may be effective in producing group specific reactions. 6. Only an occasional person showed sensitiveness to 3-methyl catechol (short side-chain), and in one instance the group reactivity appeared to be specific for the 3-position. 7. The position of the side-chain in the catechol configuration has some bearing on the degree and incidence of group reactions in persons hypersensitive to poison ivy. 8. Evidence is presented to indicate that the introduction of double bonds in the

  1. Protocol for the development of the Master Chemical Mechanism, MCM v3 (Part A: tropospheric degradation of non-aromatic volatile organic compounds

    Directory of Open Access Journals (Sweden)

    S. M. Saunders

    2003-01-01

    Full Text Available Kinetic and mechanistic data relevant to the tropospheric degradation of volatile organic compounds (VOC, and the production of secondary pollutants, have previously been used to define a protocol which underpinned the construction of a near-explicit Master Chemical Mechanism. In this paper, an update to the previous protocol is presented, which has been used to define degradation schemes for 107 non-aromatic VOC as part of version 3 of the Master Chemical Mechanism (MCM v3. The treatment of 18 aromatic VOC is described in a companion paper. The protocol is divided into a series of subsections describing initiation reactions, the reactions of the radical intermediates and the further degradation of first and subsequent generation products. Emphasis is placed on updating the previous information, and outlining the methodology which is specifically applicable to VOC not considered previously (e.g. a- and b-pinene. The present protocol aims to take into consideration work available in the open literature up to the beginning of 2001, and some other studies known by the authors which were under review at the time. Application of MCM v3 in appropriate box models indicates that the representation of isoprene degradation provides a good description of the speciated distribution of oxygenated organic products observed in reported field studies where isoprene was the dominant emitted hydrocarbon, and that the a-pinene degradation chemistry provides a good description of the time dependence of key gas phase species in a-pinene/NOX photo-oxidation experiments carried out in the European Photoreactor (EUPHORE. Photochemical Ozone Creation Potentials (POCP have been calculated for the 106 non-aromatic non-methane VOC in MCM v3 for idealised conditions appropriate to north-west Europe, using a photochemical trajectory model. The POCP values provide a measure of the relative ozone forming abilities of the VOC. Where applicable, the values are compared with

  2. Sensory effects of capsaicin congeners. Part II: Importance of chemical structure and pungency in desensitizing activity of capsaicin-type compounds.

    Science.gov (United States)

    Szolcsányi, J; Jancsó-Gábor, A

    1976-01-01

    The characteristic insensitivity of sensory nerve endings to chemically induced pain brought about by capsaicin could be reproduced on the rat's eye by pungent vanillylamides, homovanilloyl-alkylamides and piperine, while homovanilloyl-cycloalkylamides, -azacycloalkylamides, - alkylesters, -alkyl-homovanillylamides, undecenoyl-3-aminopropranololand zingerone were practically ineffective in this respect. Desensitizing potency was not parallel with the stimulating effect of the compounds, e.g. the strongly pungent homovanilloyl-octylester failed to desensitize the receptors, while the less pungent homovanilloyl-dodecylamide proved to be a more potent desensitizing agent than capsaicin itself. It is concluded that the inverse position of the acylamide linkage does not modify, while its replacement by an esteric group completely abolishes the desensitizing activity. In contrast to the stimulating effect, in desensitizing action the presence of an alkyl chain is essential and its optimal length corresponds to 10-12 C atoms. On the basis of these results the possible molecular interactions at the site of action are discussed.

  3. Characterization of performance reference compound kinetics and analyte sampling rate corrections under three flow regimes using nylon organic chemical integrative samplers.

    Science.gov (United States)

    Morrison, Shane A; Belden, Jason B

    2016-09-30

    Performance reference compounds (PRCs) can be spiked into passive samplers prior to deployment. If the dissipation kinetics of PRCs from the sampler corresponds to analyte accumulation kinetics, then PRCs can be used to estimate in-situ sampling rates, which may vary depending on environmental conditions. Under controlled laboratory conditions, the effectiveness of PRC corrections on prediction accuracy of water concentrations were evaluated using nylon organic chemical integrative samplers (NOCIS). Results from PRC calibrations suggest that PRC elimination occurs faster under higher flow conditions; however, minimal differences were observed for PRC elimination between fast flow (9.3cm/s) and slow flow (5.0cm/s) conditions. Moreover, minimal differences were observed for PRC elimination from Dowex Optipore L-493; therefore, PRC corrections did not improve results for NOCIS configurations containing Dowex Optipore L-493. Regardless, results suggest that PRC corrections were beneficial for NOCIS configurations containing Oasis HLB; however, due to differences in flow dependencies of analyte sampling rates and PRC elimination rates across the investigated flow regimes, the use of multiple PRC corrections was necessary. As such, a "Best-Fit PRC" approach was utilized for Oasis HLB corrections using caffeine-(13)C3, DIA-d5, or no correction based on the relative flow dependencies of analytes and these PRCs. Although PRC corrections reduced the variability when in-situ conditions differed from laboratory calibrations (e.g. static versus moderate flow), applying PRC corrections under similar flow conditions increases variability in estimated values.

  4. Characterization of chemical-induced sterile inflammation in vitro: application of the model compound ketoconazole in a human hepatic co-culture system.

    Science.gov (United States)

    Wewering, Franziska; Jouy, Florent; Wissenbach, Dirk K; Gebauer, Scarlett; Blüher, Matthias; Gebhardt, Rolf; Pirow, Ralph; von Bergen, Martin; Kalkhof, Stefan; Luch, Andreas; Zellmer, Sebastian

    2017-02-01

    Liver injury as a result of a sterile inflammation is closely linked to the activation of immune cells, including macrophages, by damaged hepatocytes. This interaction between immune cells and hepatocytes is as yet not considered in any of the in vitro test systems applied during the generation of new drugs. Here, we established and characterized a novel in vitro co-culture model with two human cell lines, HepG2 and differentiated THP-1. Ketoconazole, an antifungal drug known for its hepatotoxicity, was used as a model compound in the testing of the co-culture. Single cultures of HepG2 and THP-1 cells were studied as controls. Different metabolism patterns of ketoconazole were observed for the single and co-culture incubations as well as for the different cell types. The main metabolite N-deacetyl ketoconazole was found in cell pellets, but not in supernatants of cell cultures. Global proteome analysis showed that the NRF2-mediated stress response and the CXCL8 (IL-8) pathway were induced by ketoconazole treatment under co-culture conditions. The upregulation and ketoconazole-induced secretion of several pro-inflammatory cytokines, including CXCL8, TNF-α and CCL3, was observed in the co-culture system only, but not in single cell cultures. Taking together, we provide evidence that the co-culture model applied might be suitable to serve as tool for the prediction of chemical-induced sterile inflammation in liver tissue in vivo.

  5. Effect of different extraction methods on fatty acids, volatile compounds, and physical and chemical properties of avocado (Persea americana Mill.) oil.

    Science.gov (United States)

    Moreno, Alicia Ortiz; Dorantes, Lidia; Galíndez, Juvencio; Guzmán, Rosa I

    2003-04-09

    Because Mexico is the number one producer of avocados in the world, this fruit has potential as a source for oil extraction. It is appropriate to further investigate the detailed changes that the oil undergoes when different extraction methods are applied. This research paper presents the study of the physical and chemical changes, the fatty acids profile, the trans fatty acid content, and the identification of volatile compounds of the oils from avocado pulp (Persea americana Mill.), obtained by four different extraction methods. The method with the greatest extraction yield was the combined microwave-hexane method. The amount of trans fatty acids produced in the microwave-squeezing treatment was <0.5 g/100 g. On the other hand, the amounts of trans fatty acids produced with the hexane and acetone treatments were 0.52 and 0.87 g/100 g, respectively. The method that caused the slightest modification to the oil quality was a novel combined extraction method of microwave-squeezing proposed by the authors.

  6. Design of a disulfide-less, pharmacologically inert, and chemically competent analog of maurocalcine for the efficient transport of impermeant compounds into cells.

    Science.gov (United States)

    Ram, Narendra; Weiss, Norbert; Texier-Nogues, Isabelle; Aroui, Sonia; Andreotti, Nicolas; Pirollet, Fabienne; Ronjat, Michel; Sabatier, Jean-Marc; Darbon, Hervé; Jacquemond, Vincent; De Waard, Michel

    2008-10-03

    Maurocalcine is a 33-mer peptide initially isolated from the venom of a Tunisian scorpion. It has proved itself valuable as a pharmacological activator of the ryanodine receptor and has helped the understanding of the molecular basis underlying excitation-contraction coupling in skeletal muscles. Because of its positively charged nature, it is also an innovative vector for the cell penetration of various compounds. We report a novel maurocalcine analog with improved properties: (i) the complete loss of pharmacological activity, (ii) preservation of the potent ability to carry cargo molecules into cells, and (iii) coupling chemistries not affected by the presence of internal cysteine residues of maurocalcine. We did this by replacing the six internal cysteine residues of maurocalcine by isosteric 2-aminobutyric acid residues and by adding an additional N-terminal biotinylated lysine (for a proof of concept analog) or an N-terminal cysteine residue (for a chemically competent coupling analogue). Additional replacement of a glutamate residue by alanyl at position 12 further improves the potency of these analogues. Coupling to several cargo molecules or nanoparticles are presented to illustrate the cell penetration potency and usefulness of these pharmacologically inactive analogs.

  7. Combinatorial bio/chemical analysis of dioxin and dioxin-like compounds in waste recycling, feed/food, humans/wildlife and the environment.

    Science.gov (United States)

    Behnisch, P A; Hosoe, K; Sakai, S

    2001-12-01

    The present review describes international activities using bioassays/biomarkers in combination with chemical analysis to measure the effects of dioxin and dioxin-like compounds (DLCs) in the environment. The above authors reviewed already the state-of-art bioanalytical detection methods (BDMs) for dioxins and DLCs [Environ Int (2001)]. The aim of this study will be to review applications of these bioassays/biomarkers to evaluate potential dioxins and DLCs. The present literature study lists relative potencies (REPs) of polyhalogenated dibenzo-p-dioxins and -furans (PXDD/Fs; X = Cl, Br, F), their thio analogues polychlorinated dibenzothiophenes (PCDTs) and thianthrens (PCTAs), polyhalogenated biphenyls (PXBs), polychlorinated naphthalenes (PCNs) and other Ah receptor agonists measured by several biodetectors (Tier 3 screening). The authors will discuss some examples of the applications of some of these biodetectors in biomonitoring programmes and recently occurred dioxin crisis in feed/food. The diagnosis of the biopotency of these pollutants in technical processes like thermally treated waste, waste water treatment, landfill leachate treatment, commercial PCB-mixtures, the release into the environment (soil, air and water) and the final intake into wildlife and humans will be reviewed.

  8. Protocol for the development of the Master Chemical Mechanism, MCM v3 (Part B: tropospheric degradation of aromatic volatile organic compounds

    Directory of Open Access Journals (Sweden)

    M. E. Jenkin

    2003-01-01

    Full Text Available Kinetic and mechanistic data relevant to the tropospheric degradation of aromatic volatile organic compounds (VOC have been used to define a mechanism development protocol, which has been used to construct degradation schemes for 18 aromatic VOC as part of version 3 of the Master Chemical Mechanism (MCM v3. This is complementary to the treatment of 107 non-aromatic VOC, presented in a companion paper. The protocol is divided into a series of subsections describing initiation reactions, the degradation chemistry to first generation products via a number of competitive routes, and the further degradation of first and subsequent generation products. Emphasis is placed on describing where the treatment differs from that applied to the non-aromatic VOC. The protocol is based on work available in the open literature up to the beginning of 2001, and some other studies known by the authors which were under review at the time. Photochemical Ozone Creation Potentials (POCP have been calculated for the 18 aromatic VOC in MCM v3 for idealised conditions appropriate to north-west Europe, using a photochemical trajectory model. The POCP values provide a measure of the relative ozone forming abilities of the VOC. These show distinct differences from POCP values calculated previously for the aromatics, using earlier versions of the MCM, and reasons for these differences are discussed.

  9. Protocol for the development of the Master Chemical Mechanism, MCM v3 (Part B: tropospheric degradation of aromatic volatile organic compounds

    Directory of Open Access Journals (Sweden)

    M. E. Jenkin

    2002-11-01

    Full Text Available Kinetic and mechanistic data relevant to the tropospheric degradation of aromatic volatile organic compounds (VOC have been used to define a mechanism development protocol, which has been used to construct degradation schemes for 18 aromatic VOC as part of version 3 of the Master Chemical Mechanism (MCM v3. This is complementary to the treatment of 107 non-aromatic VOC, presented in a companion paper. The protocol is divided into a series of subsections describing initiation reactions, the degradation chemistry to first generation products via a number of competitive routes, and the further degradation of first and subsequent generation products. Emphasis is placed on describing where the treatment differs from that applied to the non-aromatic VOC. The protocol is based on work available in the open literature up to the beginning of 2001, and some other studies known by the authors which were under review at the time. Photochemical Ozone Creation Potentials (POCP have been calculated for the 18 aromatic VOC in MCM v3 for idealised conditions appropriate to north-west Europe, using a photochemical trajectory model. The POCP values provide a measure of the relative ozone forming abilities of the VOC. These show distinct differences from POCP values calculated previously for the aromatics, using earlier versions of the MCM, and reasons for these differences are discussed.

  10. HL271, a novel chemical compound derived from metformin, differs from metformin in its effects on the circadian clock and metabolism.

    Science.gov (United States)

    Row, Hansang; Jeong, Jaekap; Cho, Sehyung; Kim, Sungwuk; Kim, Kyungjin

    2016-01-15

    Metformin is a treatment of choice for patients with type 2 diabetes. Its action involves the phosphorylation of 5'-adenosine monophosphate activated protein kinase (AMPK), leading to inhibition of liver gluconeogenesis. The effects of a novel chemical compound derived from metformin, HL271, on molecular and physiological actions involving AMPK and rhythmically-expressed circadian clock genes were investigated. HL271 potently activated AMPK in a dose-dependent manner, and produced shortening of the circadian period and enhanced degradation of the clock genes PER2 and CRY1. Although the molecular effects of HL271 resembled those of metformin, it produced different physiological effects in mice with diet-induced obesity. HL271 did not elicit glucose-lowering or insulin-sensitizing effects, possibly because of altered regulation of glucose-6-phosphatase and phosphoenolpyruvate carboxykinase 1. This indicated that, although HL271 acted on circadian clock machinery through a similar molecular mechanism to metformin, it differed in its systemic effect on glucose and lipid metabolite regulations.

  11. 吴茱萸不同炮制品化学成分的变化分析%Analysis on changes of chemical compounds in different processed products of Euodiae Fructus

    Institute of Scientific and Technical Information of China (English)

    赵平; 许海玉; 许浚; 张铁军; 韩越; 王敏杰

    2011-01-01

    目的:研究吴茱萸的炮制方法与化学成分的相关性.方法:采用HPLC对吴茱萸炮制前后的色谱图进行比较;对主要色谱峰进行指认,划分化学组分群;分析已知成分和化学组分群的含量变化.结果:将色谱峰划分为黄酮苷类、吲哚喹唑啉类生物碱和苦味素类、喹诺酮类生物碱3类化学组分群.各炮制品中黄酮苷类成分含量均下降,水洗下降最多;黄连制使3类化学组分群的含量都有所降低;酒制、盐制、甘草制、姜制可以增加喹诺酮类生物碱的溶出量.结论:不同的炮制方法会造成吴茱萸化学成分的不同改变.%Objective: To study the relationship among processing methods and chemical compounds. Method: HPLC was used to compare the difference between pre and post processing. The main peaks in chromatogram were identified and divided into groups of chemical compounds. The contents of identified compounds and groups of chemical compounds were also analyzed. Result:The chromatographic peaks were divided into three groups of chemical compounds that were flavonoid glocosides, uinazoline alkaloids and bitter principle, indoloquinazoline alkaloids. The contents of flavonoid glocosides were reduced in each processed product, and that in hot - water processing product were the least. The contents of all three groups of chemical compounds were decreased in Coptidis Rhizoma processing products. The dissolving release of quinolones alkaloids were increased in wine, salt, Glycyrrhizae Radix et Rhizoma and ginger processing products. Conclusion: Different processing methods caused different changes of chemical compounds.

  12. strong water sensitivity; heavy oil reservoir; thermal recovery; thermal compound chemical flooding; electron microscope analysisA study on a thermal compound chemical method for improving development efficiency of heavy-oil reservoirs with strong sensiti%热复合化学方法改善极强敏感性稠油油藏开发效果机理

    Institute of Scientific and Technical Information of China (English)

    曹嫣镔; 于田田; 林吉生; 刘冬青; 何绍群; 王全; 夏道宏

    2013-01-01

    Heavy-oil reservoirs with extremely strong water sensitivity in the Shengli oilfield are mainly distributed in the Jinjia oilfield and their reserves amount to more than 20 million tons. In addition, the thermal recovery effect only by steam injection seems poor and it is difficult to effectively produce these reserves because the water sensitivity index for this kind of reservoirs exceeds 0. 9. In view of the above contradiction, a thermal compound chemical method research was carried out, in which real cores from the Jinjia oilfield were used to evaluate different displacement manners based on thermal compound chemical flooding, such as the vapor + high-temperature antiswelling agent, steam + high-performance oil displacement agent, and steam + high-performance oil displacement a-gent + high-temperature condensation agent. Composition changes of clay minerals, clay distributions in pore throats and radius distributions of pore throats were measured by means of X diffraction, scanning electron microscope, cast thin section and mercury-injection in order to explore principle mechanisms of the enhanced oil recovery with the thermal compound chemical method under high-temperature conditions. The results showed that the thermal compound chemical displacement manner with the steam + high-temperature oil displacement agent + high-temperature condensation agent can promote the transformation of montmorillonite to illite and the dissolution of part kaolinite at the same time, which can greatly improve pore-throat flow channels of reservoirs to form large "hot-wormholes" that remarkably increase the permeability and flooding displacement efficiency of heavy-oil reservoirs with strong water sensitivity.%胜利油田极强水敏性稠油油藏主要分布在金家油田,储量在2 000×104 t以上,该类油藏水敏指数在0.9以上,单纯注蒸汽热采开发效果差,无法实现有效动用.笔者针对以上矛盾,开展了热复合化学方法开采技术研究.利用

  13. New technology for the investigation of water vapor sorption-induced crystallographic form transformations of chemical compounds: a water vapor sorption gravimetry-dispersive Raman spectroscopy coupling.

    Science.gov (United States)

    Feth, Martin Philipp; Jurascheck, Jörg; Spitzenberg, Michael; Dillenz, Jürgen; Bertele, Günter; Stark, Herbert

    2011-03-01

    coupling is a powerful tool to study solid-state transitions of pharmaceutical compounds or galenic formulations. The information obtained can, for example, be used to optimize drying, conditioning, or rerystallization processes of chemical products or to determine their optimal storage conditions. This is especially interesting for physically and chemically labile hydrate phases.

  14. Protocol for the development of the Master Chemical Mechanism, MCM v3 (Part A: tropospheric degradation of non-aromatic volatile organic compounds

    Directory of Open Access Journals (Sweden)

    S. M. Saunders

    2002-11-01

    Full Text Available Kinetic and mechanistic data relevant to the tropospheric degradation of volatile organic compounds (VOC, and the production of secondary pollutants, have previously been used to define a protocol which underpinned the construction of a near-explicit Master Chemical Mechanism. In this paper, an update to the previous protocol is presented, which has been used to define degradation schemes for 107 non-aromatic VOC as part of version 3 of the Master Chemical Mechanism (MCM v3. The treatment of 18 aromatic VOC is described in a companion paper. The protocol is divided into a series of subsections describing initiation reactions, the reactions of the radical intermediates and the further degradation of first and subsequent generation products. Emphasis is placed on updating the previous information, and outlining the methodology which is specifically applicable to VOC not considered previously (e.g. a- and b-pinene. The present protocol aims to take into consideration work available in the open literature up to the beginning of 2001, and some other studies known by the authors which were under review at the time. Application of MCM v3 in appropriate box models indicates that the representation of isoprene degradation provides a good description of the speciated distribution of oxygenated organic products observed in reported field studies where isoprene was the dominant emitted hydrocarbon, and that the a-pinene degradation chemistry provides a good description of the time dependence of key gas phase species in a-pinene/NOX photo-oxidation experiments carried out in the European Photoreactor (EUPHORE. Photochemical Ozone Creation Potentials (POCP have been calculated for the 106 non-aromatic non-methane VOC in MCM v3 for idealised conditions appropriate to north-west Europe, using a photochemical trajectory model. The POCP

  15. Validation of chemical compound library screening for transcriptional co-activator with PDZ-binding motif inhibitors using GFP-fused transcriptional co-activator with PDZ-binding motif.

    Science.gov (United States)

    Nagashima, Shunta; Maruyama, Junichi; Kawano, Shodai; Iwasa, Hiroaki; Nakagawa, Kentaro; Ishigami-Yuasa, Mari; Kagechika, Hiroyuki; Nishina, Hiroshi; Hata, Yutaka

    2016-06-01

    Transcriptional co-activator with PDZ-binding motif (TAZ) plays versatile roles in cell proliferation and differentiation. It is phosphorylated by large tumor suppressor kinases, the core kinases of the tumor-suppressive Hippo pathway. Phosphorylation induces the cytoplasmic accumulation of TAZ and its degradation. In human cancers, the deregulation of the Hippo pathway and gene amplification enhance TAZ activity. TAZ interacts with TEA domain family members (TEAD), and upregulates genes implicated in epithelial-mesenchymal transition. It also confers stemness to cancer cells. Thus, TAZ activation provides cancer cells with malignant properties and worsens the clinical prognosis. Therefore, TAZ attracts attention as a therapeutic target in cancer therapy. We applied 18 606 small chemical compounds to human osteosarcoma U2OS cells expressing GFP-fused TAZ (GFP-TAZ), monitored the subcellular localization of GFP-TAZ, and selected 33 compounds that shifted GFP-TAZ to the cytoplasm. Unexpectedly, only a limited number of compounds suppressed TAZ-mediated enhancement of TEAD-responsive reporter activity. Moreover, the compounds that weakened TEAD reporter activity did not necessarily decrease the unphosphorylated TAZ. In this study, we focused on three compounds that decreased both TEAD reporter activity and unphosphorylated TAZ, and treated several human cancer cells with these compounds. One compound did not show a remarkable effect, whereas the other two compounds compromised the cell viability in certain cancer cells. In conclusion, the GFP-TAZ-based assay can be used as the first screening for compounds that inhibit TAZ and show anticancer properties. To develop anticancer drugs, we need additional assays to select the compounds.

  16. Characterizing the chemical evolution of air masses via multi-platform measurements of volatile organic compounds (VOCs) during CalNEX: Composition, OH reactivity, and potential SOA formation

    Science.gov (United States)

    Gilman, J. B.; Kuster, W. C.; Bon, D.; Warneke, C.; Lerner, B. M.; Williams, E. J.; Holloway, J. S.; Pollack, I. B.; Ryerson, T. B.; Atlas, E. L.; Blake, D. R.; Herndon, S. C.; Zahniser, M. S.; Vlasenko, A. L.; Li, S.; Alvarez, S. L.; Rappenglueck, B.; Flynn, J. H.; Grossberg, N.; Lefer, B. L.; De Gouw, J. A.

    2011-12-01

    Volatile organic compounds (VOCs) are critical components in the photochemical production of ozone (O3) and secondary organic aerosol (SOA). During the CalNex 2010 field campaign, an extensive set of VOCs were measured at the Pasadena ground site, and aboard the NOAA WP-3D aircraft and the WHOI Research Vessel Atlantis. The measurements from each platform provide a unique perspective into the emissions, transport, and atmospheric processing of VOCs within the South Coast Air Basin (SoCAB). The observed enhancement ratios of the hydrocarbons measured on all three platforms are in good agreement and are generally well correlated with carbon monoxide (CO), indicating the prevalence of on-road VOC emission sources throughout the SoCAB. Offshore measurements aboard the ship and aircraft are used to characterize the air mass composition as a function of the land/sea-breeze effect. VOC ratios and other trace gases are used to identify air masses containing relatively fresh emissions that were often associated with offshore flow and re-circulated continental air associated with onshore flow conditions. With the prevailing southwesterly airflow pattern in the LAB throughout the daytime, the Pasadena ground site effectively functions as a receptor site and is used to characterize primary VOC emissions from downtown Los Angeles and to identify the corresponding secondary oxidation products. The chemical evolution of air masses as a function of the time of day is investigated in order to determine the relative impacts of primary emissions vs. secondary VOC products on OH reactivity and potential SOA formation. The reactivity of VOCs with the hydroxyl radical (OH) at the Pasadena site was dominated by the light hydrocarbons, isoprene, and oxygenated VOCs including aldehydes (secondary products) and alcohols (primary anthropogenic emissions). Toluene and benzaldehyde, both of which are associated with primary anthropogenic emissions, are the predominant VOC precursors to the

  17. Simultaneous detection of polar and nonpolar compounds by ambient mass spectrometry with a dual electrospray and atmospheric pressure chemical ionization source.

    Science.gov (United States)

    Cheng, Sy-Chyi; Jhang, Siou-Sian; Huang, Min-Zong; Shiea, Jentaie

    2015-02-03

    A dual ionization source combining electrospray ionization (ESI) and atmospheric pressure chemical ionization (APCI) was developed to simultaneously ionize both polar and nonpolar compounds. The source was constructed by inserting a fused silica capillary into a stainless steel column enclosed in a glass tube. A high dc voltage was applied to a methanol solution flowing in the fused silica capillary to generate an ESI plume at the capillary tip. A high ac voltage was applied to a ring electrode attached to the glass tube to generate plasma from the nitrogen gas flowing between the glass tube and the stainless steel column. The concentric arrangement of the ESI plume and the APCI plasma in the source ensured that analytes entering the ionization region interacted with both ESI and APCI primary ion species generated in the source. Because the high voltages required for ESI and APCI were independently applied and controlled, the dual ion source could be operated in ESI-only, APCI-only, or ESI+APCI modes. Analytes were introduced into the ESI and/or APCI plumes by irradiating sample surfaces with a continuous-wavelength laser or a pulsed laser beam. Analyte ions could also be produced by directing the dual ESI+APCI source toward sample surfaces for desorption and ionization. The ionization mechanisms involved in the dual ion source include Penning ionization, ion molecule reactions, and fused-droplet electrospray ionization. Standards of polycyclic aromatic hydrocarbons, angiotensin I, lidocaine, ferrocene, diesel, and rosemary oils were used for testing. Protonated analyte ions were detected in ESI-only mode, radical cations were detected in APCI-only mode, and both types of ions were detected in ESI+APCI mode.

  18. Microwave spectrum, structure, and quantum chemical studies of a compound of potential astrochemical and astrobiological interest: Z-3-amino-2-propenenitrile.

    Science.gov (United States)

    Askeland, Eva; Møllendal, Harald; Uggerud, Einar; Guillemin, Jean-Claude; Aviles Moreno, Juan-Ramon; Demaison, Jean; Huet, Thérèse R

    2006-11-23

    Z-3-Amino-2-propenenitrile, H2NCH=CHCN, a compound of astrochemical and astrobiological interest, has been studied by Stark and Fourier transform microwave spectroscopy along with eight of its isotopologues; the synthesis of five of these are reported. The spectra of the ground vibrational state and of three vibrationally excited states belonging to the two lowest normal modes were assigned for the parent species, whereas the ground states were assigned for the isotopologues. The frequency of the lowest in-plane bending fundamental vibration was determined to be 152(20) cm(-1) and the frequency of the lowest out-of-plane fundamental mode was found to be 176(20) cm(-1) by relative intensity measurements. A delicate problem is whether this compound is planar or slightly nonplanar. It was found that the rotational constants of the nine species cannot be used to conclude definitely whether the molecule is planar or not. The experimental dipole moment is mu(a) = 16.45(12), mu(b) = 2.86(6), mu(c) = 0 (assumed), and mu(tot.) = 16.70(12) x 10(-30) C m [5.01(4) D]. The quadrupole coupling constants of the two nitrogen nuclei are chi(aa) = -1.4917(21) and chi(cc) = 1.5644(24) MHz for the nitrogen atom of the cyano group and chi(aa) = 1.7262(18) and chi(cc) = -4.0591(17) MHz for the nitrogen atom of the amino group. Extensive quantum-chemical calculations have been performed, and the results obtained from these calculations have been compared with the experimental values. The equilibrium structures of vinylamine, vinyl cyanide, and Z-3-amino-2-propenenitrile have been calculated. These calculations have established that the equilibrium structure of the title compound is definitely nonplanar. However, the MP2/VQZ energy difference between the planar and nonplanar forms is small, only -423 J/mol. Z-Amino-2-propenenitrile and E-3-amino-2-propenenitrile are formed simply by mixing ammonia and cyanoacetylene at room temperature. A plausible reaction path has been modeled. G3

  19. Ecotoxicology of organofluorous compounds.

    Science.gov (United States)

    Murphy, Margaret B; Loi, Eva I H; Kwok, Karen Y; Lam, Paul K S

    2012-01-01

    Organofluorous compounds have been developed for myriad purposes in a variety of fields, including manufacturing, industry, agriculture, and medicine. The widespread use and application of these compounds has led to increasing concern about their potential ecological toxicity, particularly because of the stability of the C-F bond, which can result in chemical persistence in the environment. This chapter reviews the chemical properties and ecotoxicology of four groups of organofluorous compounds: fluorinated refrigerants and propellants, per- and polyfluorinated compounds (PFCs), fluorinated pesticides, and fluoroquinolone antibiotics. These groups vary in their environmental fate and partitioning, but each raises concern in terms of ecological risk on both the regional and global scale, particularly those compounds with long environmental half-lives. Further research on the occurrence and toxicities of many of these compounds is needed for a more comprehensive understanding of their ecological effects.

  20. Nano-porous sponges and proven chemical reactions for the trapping and sensing of halogenated gaseous compounds; Le piegeage et la detection de composes halogenes gazeux. Utilisation d'eponges nanoporeuses et de reactions chimiques

    Energy Technology Data Exchange (ETDEWEB)

    Banet, P. [Universite de Cergy Pontoise, Lab. de Physico-Chimie des Polymeres et des Interfaces (LPPI), 95 - Neuville sur Oise (France); Cantau, C. [Institut de Chimie de la Matiere Condensee (ICMCB-CNRS), 33 - Pessac (France); Rivron, C.; Tran-Thi, T.H. [CEA Saclay (DSM/DRECAM/SPAM), Lab. Francis Perrin, URA CEA-CNRS 2453, 91 - Gif-sur-Yvette (France)

    2009-06-15

    The literature is well illustrated with examples of porous materials elaborated via the sol-gel process, which display high adsorption surface area suitable for the trapping of volatile organic compounds (VOC). Very often, the porous network of these materials is randomly distributed in terms of pore size. However, some materials can display very ordered nano-structures with uniform pore sizes or hierarchical structures with microscopic (< 2 nm) and mesoscopic (2-60 nm) domains. The utility of such organized media and the possibility of reproducing liquid phase chemical reactions in these confined environments are here discussed with regards to their potentiality as sensitive layers of chemical sensors for the detection of gaseous pollutants. To illustrate the potentiality of the porous materials and the importance of the chemical reactivity at gas-solid interfaces, an example of a chemical sensor which detects chlorine, a toxic industrial gas encountered in microelectronics and semiconductor industries, will be given. (authors)

  1. Synthesis, spectroscopic and X-ray structural characterization, quantum chemical studies and investigation of gama-irradiated effects of the novel hydrazone compound: [(E)-3-(2-nitrophenyl)-(E)-1-(2-phenylhydrazono)]-1-phenylallylidene

    Science.gov (United States)

    Yakalı, Gül; Çakıcı, Abban; Eke, Canel; Cin, Günseli Turgut; Aygün, Muhittin

    2017-04-01

    The novel hydrazone compound, [(E)-3-(2-nitrophenyl)-(E)-1-(2-phenylhydrazono)]-1-phenylallylidene (2), has been synthesized, characterized by FTIR, 1H NMR, 13C NMR techniques, elemental analysis, X-ray structure analysis and has been investigated gama-irradiated effect. Additionally, the molecular geometrical parameters, frontier molecular orbital energies (HOMO, LUMO), their energy gap (Δ E) , molecular electrostatic potential analysis of the compound have been calculated by using DFT/B3LYP with 6-311G (d, p) level. Also, IR frequencies, 1H and 13C NMR chemical shifts of the compound were calculated by using DFT calculations at the same level basis and changing in lattice parameters, unit cell volume and density of the compound are observed after gama irradiated at XRD data. Unirradiated state of the title compound (C21H17N3O2) crystallizes in the monoclinic space group P21/n with a = 9.1782(7) Å, b = 16.1359(12) Å, c = 11.9709(12) Å, β = 101.022(8)o, V = 1740.2(3) Å3, Dcalc = 1.3106 g/cm3 and Z = 4 while irradiated state of title compound showed significant changes in lattice parameters, crystal volume and density. In contrast, the crystal system is found to be the same at after and before irradiation. The calculated geometrical parameters, IR frequencies, 1H and 13C NMR chemical shifts of the compound were in good agreement with the observed single crystal- XRD data, IR, 1H and 13C NMR spectra.

  2. Chemical characterization of aromatic compounds in extra heavy gas oil by comprehensive two-dimensional gas chromatography coupled to time-of-flight mass spectrometry.

    Science.gov (United States)

    Avila, Bárbara M F; Pereira, Ricardo; Gomes, Alexandre O; Azevedo, Débora A

    2011-05-27

    Comprehensive two-dimensional gas chromatography coupled to time-of-flight mass spectrometry (GC×GC-TOFMS) was used for the characterization of aromatic compounds present in extra heavy gas oil (EHGO) from Brazil. Individual identification of EHGO compounds was successfully achieved in addition to group-type separation on the chromatographic plane. Many aromatic hydrocarbons, especially polycyclic aromatic hydrocarbons and sulfur compounds, were detected and identified, such as chrysenes, phenanthrenes, perylenes, benzonaphthothiophenes and alkylbenzonaphthothiophenes. In addition, triaromatic steroids, methyl-triaromatic steroids, tetrahydrochrysenes and tetraromatic pentacyclic compounds were present in the EHGO aromatic fractions. Considering the roof-tile effect observed for many of these compound classes and the high number of individual compounds identified, GC×GC-TOFMS is an excellent technique to characterize the molecular composition of the aromatic fraction from EHGO samples. Moreover, data processing allowed the quantification of aromatic compounds, in class and individually, using external standards. EHGO data were obtained in μgg(-1), e.g., benzo[a]pyrene were in the range 351 to 1164μgg(-1). Thus, GC×GC-TOFMS was successfully applied in EHGO quantitative analysis.

  3. Phenolic Compounds of Pinus brutia Ten.: Chemical Investigation and Quantitative Analysis Using an Ultra-Performance Liquid Chromatography Tandem Mass Spectrometry with Electrospray Ionization Source

    Directory of Open Access Journals (Sweden)

    İbrahim Kıvrak

    2013-08-01

    Full Text Available In this study, phenolic content of Pinus brutia ’s bark was examined using an ultra-performance liquid chromatography tandem mass spectrometry with electrospray ionization source (UPLC-ESI-MS/MS working in multiple reaction monitoring mode. U ltrasonic extraction method with 50% ethanol solution was used for the extraction of bark. The bark of Pinus brutia consisted of 15 compounds: gallic acid, gentisic acid, protocatechuic acid, 4-hydroxy benzoic acid, catechin hydrate, vanillic acid, caffeic acid, vanillin, p-coumaric acid, ferulic acid, myricetin, resveratrol, luteolin, naringenin, kaempferol. Major compound detected was catechin hydrate (28.305 mg 100 g -1 extract. The phenolic compounds of Pinus brutia extract and pycnogenol were compared, and it is shown that both of them consisted of considerable amount of phenolic compounds.

  4. Characteristic Chemical Components and Aroma-active Compounds of the Essential Oils from Ranunculus nipponicus var. submersus Used in Japanese Traditional Food.

    Science.gov (United States)

    Nakaya, Satoshi; Usami, Atsushi; Yorimoto, Tomohito; Miyazawa, Mitsuo

    2015-01-01

    Ranunculus nipponicus var. submersus is an aquatic macrophyte; it is known as a wild edible plant in Japan for a long time. In this study, the essential oils from the fresh and dried aerial parts of R. nipponicus var. submersus were extracted by hydrodistillation and analyzed by gas chromatography (GC) and GC-mass spectrometry (GC-MS). Moreover, important aroma-active compounds were also detected in the oil using GC-olfactometry (GC-O) and aroma extract dilution analysis (AEDA). Thus, 98 compounds (accounting for 93.86%) of the oil were identified. The major compounds in fresh plant oil were phytol (41.94%), heptadecane (5.92%), and geranyl propionate (5.76%), while those of. Dried plant oil were β-ionone (23.54%), 2-hexenal (8.75%), and dihydrobovolide (4.81%). The fresh and dried oils had the green-floral and citrus-floral odor, respectively. The GC-O and AEDA results show that phenylacetaldehyde (green, floral odor, FD-factor = 8) and β-ionone (violet-floral odor, FD-factor = 8) were the most characteristic odor compounds of the fresh oils. β-Cyclocitral (citrus odor, FD-factor = 64) and β-ionone (violet-floral odor, FD-factor = 64) were the most characteristic odor compounds of the dried oil. These compounds are thought to contribute to the flavor of R. nipponicus var. submersus.

  5. 化学物质诱导变态后紫贻贝稚贝的生长及存活%Growth and survival of the mussel Mytilus galloprovincialis post-larvae metamorphosed using different chemical compounds as inducers

    Institute of Scientific and Technical Information of China (English)

    杨金龙; 李一峰; 沈和定; SATUITO Glenn Cyril; KITAMUTRA Hitoshi

    2009-01-01

    在以往实验的基础上,跟踪调查了筛选出的化学诱导物质对紫贻贝(Mytilus edulis)幼虫变态后的生长和成活率的影响,并比较了其与相同条件下自然诱导物、微生物膜诱导后的稚贝的生长和成活率.实验结果表明,肾上腺素、苯肾上腺素、可乐宁、KCI和NH_4Cl 5种化学物质均成功地诱导了该种幼虫的变态,其变态后稚贝同微生物诱导变态后的稚贝以相同的速度生长,且在培育过程中无死亡稚贝出现.因此,这些化学物质可作为该种养殖以及海洋防污染研究中幼虫变态的有效人工诱导物.%The growth and survival of Mytilus galloprovincialis post-larvae metamorphosed using different chemical compounds were investigated in this study to identify potential inducers in aquaculture and anti-fouling and biofouling researches. All tested chemical compounds including epinephrine, phenylephrine, clonidine, KCl and NH_4 Cl induced larvae to metamorphose, and post-larvae metamorphosed using these compounds survived as juveniles and grew at the same rate as those from microbial biofilms. These chemical compounds, therefore, can be used as effective inducers of larval metamorphosis in aquaculture and antifoul-ing and biofouling studies using juveniles.

  6. Visible-light sensitization of TiO{sub 2} photocatalysts via wet chemical N-doping for the degradation of dissolved organic compounds in wastewater treatment: a review

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Wei, E-mail: Wei.Zhang@unisa.edu.au [University of Cincinnati, Environmental Engineering and Science Program, School of Energy, Environmental, Biological and Medical Engineering (United States); Jia, Baoping; Wang, Qiuze [Changzhou University, School of Materials Science and Engineering (China); Dionysiou, Dionysois [University of Cincinnati, Environmental Engineering and Science Program, School of Energy, Environmental, Biological and Medical Engineering (United States)

    2015-05-15

    Increased pollution of ground and surface water and emerging new micropollutants from a wide variety of industrial, municipal, and agricultural sources has increased demand on the development of innovative new technologies and materials whereby challenges associated with the provision of safe potable water can be addressed. Heterogeneous photocatalysis using visible-light sensitized TiO{sub 2} photocatalysts has attracted a lot of attention as it can effectively remove dissolved organic compound in water without generating harmful by-products. On this note, recent progress on visible-light sensitive TiO{sub 2} synthesis via wet chemical N-doping method is reviewed. In a typical visible-light sensitive TiO{sub 2} preparation via wet chemical methods, the chemical (e.g., N-doping content and states) and morphological properties (e.g., particle size, surface area, and crystal phase) of TiO{sub 2} in as-prepared resultants are sensitively dependent on many experimental variables during the synthesis. This has also made it very difficult to provide a universal guidance at this stage with a certainty for each variable of N-doping preparation. Instead of one-factor-at-a-time style investigation, a statistically valid parameter optimization investigation for general optima of photocatalytic activity will be certainly useful. Optimization of the preparation technique is envisaged to be beneficial to many environmental applications, i.e., dissolved organic compounds removal in wastewater treatment.

  7. NATURAL POLYACETYLENE COMPOUNDS

    Directory of Open Access Journals (Sweden)

    D. A. Konovalov

    2014-01-01

    Full Text Available Polyacetylenes (polyynes are compounds which contain two or more triple bonds in its structure. About 2 000 different polyacetylenes and biogenetically related substances were identified in 24 families of higher plants. However, most of these compounds were found in seven families of flowering plants: Apiaceae (Umbelliferae, Araliaceae, Asteraceae (Compositae, Campanulaceae, Olacaceae, Pittosporaceae and Santalaceae. Polyacetylenes are relatively unstable, chemically and biologically active compounds, and present in fungi, microorganisms, marine invertebrates and other organisms except for plants. Acetylenes form distinct specialized group of chemically active natural compounds, which are biosynthesized in plants of unsaturated fatty acids. In addition to widespread aliphatic polyacetylenes thiophenes dithiacyclohexadienes (thiarubrines, thioethers, sulphoxides, sulphones, alkamides, chlorohydrins, lactones, spiroacetal enol ethers, furans, pyrans, tetrahydropyrans, isocoumarins, aromatic acetylenes were also found in plant species. Polyacetylenes are localized in different plant organs, and can be found both individually and as a compound with carbohydrates, terpene, phenolic and other compounds. Many polyacetylenes are found in the composition of the essential oils of plants and it confirms their strongly marked ecological functions. From biological point of view these compounds are often synthesized by plants as toxic or bitter antifeedants, allelopathic compounds, phytoalexins or broadly antibiotic components. Polyynes are strong photosensitizers. They exhibit anti-inflammatory, anti-coagulant, anti-bacterial, antituberculosis, anti-fungal, anti-viral, neuroprotective and neurotoxic activity. Immunostimulatory influence associated with certain allergenicity of some of these substances was established. Therefore, without a doubt polyacetylenes are of interest for the modern pharmacy and medicine.

  8. Origin of the chemical shift in X-ray absorption near-edge spectroscopy at the Mn K-Edge in manganese oxide compounds

    NARCIS (Netherlands)

    de Vries, AH; Hozoi, L; Broer, R; Broer-Braam, H.B.

    2003-01-01

    The absorption edge in Mn K-edge X-ray absorption spectra of manganese oxide compounds shows a shift of several electronvolts in going from MnO through LaMnO3 to CaMnO3. On the other hand, in X-ray photoelectron spectra much smaller shifts are observed. To identify the mechanisms that cause the obse

  9. Learning about Structural and Optical Properties of Organic Compounds through Preparation of Functional Nanomicelles While Avoiding Hazardous Chemicals or Complicated Apparatus

    Science.gov (United States)

    Langhals, Heinz; Eberspa¨cher, Moritz; Hofer, Alexander

    2015-01-01

    The synthesis of nanomicelles in the aqueous phase on the basis of nonhazardous detergents is described where azulene and a naphthalene tetracarboximide are used in this experiment to teach the relation between structural and optical properties of organic compounds and point out possible applications. The experiment covers many aspects of…

  10. New Inorganic-organic Hybrid Compound Containing One Dimensional Keggin Polyoxometalate[SiW11O39Co]6- Chains:Preparation,Characterization and Application in Chemically Bulk-modified Electrode

    Institute of Scientific and Technical Information of China (English)

    WANG Xiu-li; LIN Hong-yan; LIU Guo-cheng; CHEN Bao-kuan; BI Yan-feng

    2008-01-01

    A new inorganic-organic hybrid compound based on polyoxometalate and organic ligand formulated as (H2bpp)3[SiW11O39Co]~2H2O(1)[bpp=1,3-bis(4-pyridyl)propane]was hydrothermally synthesized and structurally characterized by elemental analysis,single-crystal X-ray diffraction,IR,TG,and cyclic voltammetry.Single-crystal X-ray diffraction analysis reveals that compound 1 consists of interesting cobalt-monosubstituted POMs one dimensional chain together with protonated bpp ligands.Additionally,the polyoxoanions combined with the discrete organic substrates by hydrogen bond interactions to afford a supramolecular 3D network structure.The hybrid compound 1 was used as a bulk modifier to fabricate a three-dimensional chemically modified carbon paste electrode(1-CPE)by direct mixing.The electrochemical behavior and electrocatalysis of 1-CPE were studied in detail.The results indicate that 1-CPE has good electrocatalytic activities toward the reduction of nitrite or bromate in 1mol/L H2SO4 aqueous solution.1-CPE shows remarkable stability that can be ascribed to the insolubility of compound 1 and the supramolecular interactions existed between 1D POM anion chains and organic ligand bpp,which is very important for practical applications in electrode modification.

  11. 钙对化学诱抗剂诱导番茄叶片酚类物质含量的影响%Effect of Calcium on Content of Phenolic Compounds Induced by Chemical Elicitors in Tomato Leaves

    Institute of Scientific and Technical Information of China (English)

    余朝阁; 周娜; 李天来; 刘志恒

    2014-01-01

    为探索钙对化学诱抗剂水杨酸(SA)、茉莉酸甲酯(MeJA)、β-氨基丁酸(BABA)和龙胆酸(GA)诱导番茄酚类物质积累的影响,在番茄6叶期用上述化学诱抗剂处理第3叶片,并分别喷施CaCl2、蒸馏水(H2O)、LaCl3和EGTA,然后测定各处理第3叶片(诱导叶)和第5叶片(非诱导叶)中酚类物质含量的变化。结果表明:(1)化学诱抗剂处理后,番茄诱导叶及其上位非诱导叶中酚类物质含量均升高;其中,SA、MeJA和GA处理后第2天,酚类物质含量迅速升高并达到高峰,而BABA处理后第1天酚类物质含量即达到高峰。(2)外源Ca2+显著促进诱抗剂对番茄叶片中酚类物质积累的诱导,4种诱抗剂与Ca2+共同处理,番茄叶片中酚类物质含量比相应诱抗剂单独处理高10%以上;而Ca2+螯合剂EGTA和质膜钙通道抑制剂LaCl3,则不同程度抑制这些诱抗剂诱导番茄叶片中酚类物质含量的提高。由此认为,钙对上述诱抗剂诱导番茄叶片中酚类物质的合成具有正调控作用。%In order to investigate the effect of calcium on synthesis of phenolic compounds induced by salicylic acid (SA), Methyl jasmonate (MeJA), β-aminobutyric acid (BABA) and gentisic acid (GA) in tomato, the 3rd leaf was treated with above chemicals in six-leaf stage. At the sametime, these plants were sprayed with CaCl2, distilled water, LaCl3 or EGTA respectively. And then, content of phenolic compounds in the 3rd (induced) and 5th (un-induced) leaves were assayed at different time after treatments. Results showed that:(1) Content of phenolic compounds both in induced and un-induced leaves increased after treatment with chemical elicitors. It reached the peak on the 2nd day after treated with SA, MeJA and GA or on the 1st day after treated with BABA. (2) Content of phenolic compounds induced by chemical elicitors was promoted by exterior Ca2+. Content of phenolic compounds in leaves treated with chemical elicitors

  12. Classification of chemicals as endocrinally active compounds. Critical review of the classification of selected pesticides and industrial chemicals as endocrinally active chemicals; Einstufung von Schadstoffen als endokrin wirksame Substanzen. Kritische Ueberpruefung der Einstufung von ausgewaehlten Pestiziden und Industriechemikalien als endokrin wirksame Substanzen

    Energy Technology Data Exchange (ETDEWEB)

    Bruhn, T.; Guelden, M.; Ludewig, S. [Kiel Univ. (Germany). Inst. fuer Toxikologie; Seibert, H.

    1999-10-01

    Different authors have published lists of chemicals, especially pesticides and industrial chemicals, reported to have 'reproductive and endocrine disrupting activities' or 'estrogenic/antiestrogenic' activities. The objective of this study was to examine what is the basis for and whether it is justified to classify chemical compounds as 'endocrine disrupters' that are contained in frequently cited overviews, but have not been discussed in a previous report (UBA-TEXTE 46/97). Depending on the level of evidence derived from literature data, substances are classified either as (i) endocrinally active or (ii) potentially endocrinally active or (iii) without sufficient data on endocrine activity. The criteria used for the classification are based on the definitions by US-EPA and the Weybridge conference. (orig.) [German] Von verschiedenen Autoren sind umfangreiche Listen mit Chemikalien, insbesondere Pestiziden und Industriechemikalien, veroeffentlicht worden, die als 'endokrin wirksam und reproduktionstoxisch' oder als 'oestrogen- bzw. 'antioestrogen wirksam' bezeichnet werden. Aufgabe der vorliegenden Studie ist es, zu untersuchen, auf welchen Grundlagen die Einstufung als 'endokrin wirksam' beruht, und zu ueberpruefen, ob sie gerechtfertigt ist. Je nach den Ergebnissen der Literaturrecherchen werden die Substanzen einer von drei Gruppen zugeordnet: 1. endokrin wirksam, 2. potentiell endokrin wirksam, 3. ohne ausreichende Hinweise auf endokrine Wirksamkeit. Die verwendeten Kritetien fuer die Zuordnung lehnen sich an die Definitionen der EPA und der Weybridge-Konferenz an. Schon in einem vorangegengenen Bericht (UBA-TEXTE 46/97) diskutierte Verbindungen werden nicht erneut behandelt. (orig.)

  13. Analytical chemical system for the determination of heavy metals and organic compounds. Annual progress report, December 1, 1978-November 30, 1979

    Energy Technology Data Exchange (ETDEWEB)

    Siggia, S.; Barnes, R.M.

    1979-10-24

    Progress has been made in the synthesis and characterization of new resins for sequestering inorganic and organic compounds. The capabilities of the poly(dithiocarbamate) resin have been extended, a new poly(acrylamidoxime) resin prepared and characterized, and a series of resins for organic compounds prepared and tested. Limited actual sample analyses have been performed with these resins. A new inductively coupled plasma source, spectrometer, and computer system have been received and they are undergoing tests and installation. With this system in place, the multielement analysis of metals during the forthcoming period will insure the application of sequestering resins to practical analysis of energy-related materials. An automated sample handling and data system has been designed, some components purchased, and construction is scheduled for 1980.

  14. Rationalization and in vitro modeling of the chemical mechanisms of the enzymatic oxidation of phenolic compounds in planta: from flavonols and stilbenoids to lignins.

    Science.gov (United States)

    Cottyn, Betty; Kollmann, Albert; Waffo-Teguo, Pierre; Ducrot, Paul-Henri

    2011-06-20

    Enzymatic oxidation of phenolic compounds is a widespread phenomenon in plants. It is responsible for the formation of many oligomers and polymers, which are generally described as the result of a combinatorial coupling of the different radicals formed through oxidation of the phenol group and delocalization of the radical. We focused our interest on several phenolic compounds that are present in plants and known to form, under enzymatic oxidation, oligomers with different type of linkages between monomers. To explain this diversity of inter-monomer linkages and their variation according to the experimental procedure used for the enzymatic oxidation, we report an alternative mechanistic pathway involving dismutation of the radicals, leading to the formation of carbocations which, thereafter, react with nucleophilic species present in the medium. This alternative pathway allows the understanding of peculiar linkages between monomeric units in the oligomer and offers new insights for understanding the formation of phenolic biopolymers in plants.

  15. A Literature Review - Problem Definition Studies on Selected Toxic Chemicals. Volume 2. Occupational Health and Safety Aspects of Phosphorus Smoke Compounds

    Science.gov (United States)

    1978-04-01

    of pyrolysis products of SBR and pyrolysis and combustion products of Bisphenol A-epichlorohydrin epoxy resin. The toxicological studies of red and...white phosphorus, the inhalation toxicity of white phosphorus smoke and the inhalation toxicity of pyrolysis products of SBR and Bisphenol A...rats exposed to the 81 pyrolysis products of epoxy resin viii I. INTRODUCTION Phosphorus smoke compounds are used by the military to produce smoke

  16. A gas chromatograph/mass spectrometry method for determining isotopic distributions in organic compounds used in the chemical approach to stable isotope separation

    Energy Technology Data Exchange (ETDEWEB)

    Martinez, A.M.; Spall, W.D.; Smith, B.F.

    1990-01-01

    A variety of gas chromatograph/mass spectrometry (GC/MS) methods have been developed to resolve benzene, benzophenone, anthracene, fluorenone, and their respective stable isotope analogs from other components by gas chromatography. The ratio of stable isotope-labeled material to natural isotopic abundance compounds is determined from the mass spectra averaged across the chromatographic peak. Both total ion and selective ion chromatographic approaches were used for relative data and comparison. 9 refs., 11 tabs.

  17. Synthesis, Crystal Structure and Quantum Chemical Investigation of Bis-Schiff Base Compounds Derived from2-phenyl-1,2,3-triazole-4-carboxaldehyde with Diamine

    Institute of Scientific and Technical Information of China (English)

    XIE Ling; LIU Gang; WANG Yan; WANG Ji-De; CHEN Jun-Feng

    2008-01-01

    Two new schiff base N,N'-bis((2-phenyl-2H-1,2,3-triazol-4-yl)methylene)-1,3-pro- panediamine (1) and N,N'-bis((2-phenyl-2H-1,2,3-triazol-4-yl)methylene) -1,4-butanediamine (2) were synthesized by condensation of 2-phenyl-1,2,3-triazole-4-carboxaldehyde with diamine, and characterized by elemental analysis, IR, 1H NMR and MS spectra. Their crystal structures were determined by X-ray single crystal diffraction. Both crystals belong to the monoclinic system, space group P21/c. For compound 1(C21H20N8, Mr=384.45): a = 16.314(3), b =5.7168(11), c = 21.316(4)(A),β= 105.3(2)°,Z = 4, V = 1917.6(7)(A)3, Dc =1.332 g/ cm3, F(000) = 808, μ = 0.086 mm- 1, R = 0.0533 and wR = 0.1460; for compound 2 (C22H22N8, Mr =398.48): a = 8.6156(17), b = 5.2964(11), c = 22.665(5) A, β = 100.54(3)°,Z = 2, V = 1016.8(4)(A)3, Dc = 1.302 g/ cm3, F (000) = 420, μ = 0.083 mm-1, R = 0.0373 and wR = 0.1155. Based on the crystal data, quantum chemistry calculation was performed on the two title compounds by means of Gaussian 98 program. The molecular orbital energies and atomic net charges population were obtained. Furthermore, we analyzed their active atoms. The investigation can serve as a theoretical guide to study the synthesis and activity of the title compounds.

  18. High throughput screening for inhibitors of REST in neural derivatives of human embryonic stem cells reveals a chemical compound that promotes expression of neuronal genes.

    Science.gov (United States)

    Charbord, Jérémie; Poydenot, Pauline; Bonnefond, Caroline; Feyeux, Maxime; Casagrande, Fabrice; Brinon, Benjamin; Francelle, Laetitia; Aurégan, Gwenaelle; Guillermier, Martine; Cailleret, Michel; Viegas, Pedro; Nicoleau, Camille; Martinat, Cécile; Brouillet, Emmanuel; Cattaneo, Elena; Peschanski, Marc; Lechuga, Marc; Perrier, Anselme L

    2013-09-01

    Decreased expression of neuronal genes such as brain-derived neurotrophic factor (BDNF) is associated with several neurological disorders. One molecular mechanism associated with Huntington disease (HD) is a discrete increase in the nuclear activity of the transcriptional repressor REST/NRSF binding to repressor element-1 (RE1) sequences. High-throughput screening of a library of 6,984 compounds with luciferase-assay measuring REST activity in neural derivatives of human embryonic stem cells led to identify two benzoimidazole-5-carboxamide derivatives that inhibited REST silencing in a RE1-dependent manner. The most potent compound, X5050, targeted REST degradation, but neither REST expression, RNA splicing nor binding to RE1 sequence. Differential transcriptomic analysis revealed the upregulation of neuronal genes targeted by REST in wild-type neural cells treated with X5050. This activity was confirmed in neural cells produced from human induced pluripotent stem cells derived from a HD patient. Acute intraventricular delivery of X5050 increased the expressions of BDNF and several other REST-regulated genes in the prefrontal cortex of mice with quinolinate-induced striatal lesions. This study demonstrates that the use of pluripotent stem cell derivatives can represent a crucial step toward the identification of pharmacological compounds with therapeutic potential in neurological affections involving decreased expression of neuronal genes associated to increased REST activity, such as Huntington disease.

  19. USE OF THE FUNGICIDE CARBENDAZIM AS A MODEL COMPOUND TO DETERMINE THE IMPACT OF ACUTE CHEMICAL EXPOSURE DURING OOCYTE MATURATION AND FERTILIZATION ON PREGNANCY OUTCOME IN THE HAMSTER

    Science.gov (United States)

    Here we use a hamster animal model to identify early pregnancy loss due to an acute chemical exposure to the female during the perifertilization interval. The fungicide carbendazim (methyl 1H-benzimidazole-2-carbamate), a microtubule poison with antimitotic activity, was selected...

  20. Original Inventions based on Chemical scaffolds and electro-physical activity-derived biosimilars interacting with specialties in biology yielding platforms for analysis in virology and antiviral compounds

    Directory of Open Access Journals (Sweden)

    Yamaji N

    2014-11-01

    Full Text Available Background: Original inventions in developing countries, in terms of number of patents filed, granted and that are taken to useful applications as well as in terms of publications of high impact remain relatively lower [1,2] compared to that of developed nations. The reasons could be attributed to lack of importance given to basic research in funding, the number of institutes involved, limited technical support or expertise available etc [1]. Though such initiatives may take a long time to yield fruits, one of the parallel steps we considered worth was to take the original inventions from Japan, born out of basic research in one field, taken through an application-oriented inter disciplinary interactive research in healthcare, thereby paving way for novel solutions. Thus was conceived, the Inventions- Inter-Disciplinary Interactions and Solutions (IIDIAS, an academic session as a part of the one-day International stem cell meet organized every year in the month of October by Nichi-In Centre for Regenerative Medicine (NCRM, an academic Institute based in Chennai, India. In the IIDIAS session, based on original invention(s presented as a prelude in brief, original interdisciplinary interactive research work based on the original invention by NCRM and/or its collaborators are presented by the faculty of the relevant institute. That will be followed by an interactive session in which the potential solutions based on the above accomplishments would be discussed. The IIDIAS session 2014 was based on the following two inventions: A bio-film-based biosimilar invented by an electro-physicist A unique polymer invented by a chemical engineer Inventions and Interdisciplinary Interactions: Invention –I: The bio-film-based biosimilar invented by an electro-physicist: An electro physicist with the Kyoto University, Japan, Dr Nobuyuki Yamaji observed during his experiments that plants and mammalian tissues secrete a layer of fluid after getting hit by

  1. Addressing the chemical sorcery of "GaI": benefits of solid-state analysis aiding in the synthesis of P→Ga coordination compounds.

    Science.gov (United States)

    Malbrecht, Brian J; Dube, Jonathan W; Willans, Mathew J; Ragogna, Paul J

    2014-09-15

    The differing structures and reactivities of "GaI" samples prepared with different reaction times have been investigated in detail. Analysis by FT-Raman spectroscopy, powder X-ray diffraction, (71)Ga solid-state NMR spectroscopy, and (127)I nuclear quadrupole resonance (NQR) provides concrete evidence for the structure of each "GaI" sample prepared. These techniques are widely accessible and can be implemented quickly and easily to identify the nature of the "GaI" in hand. The "GaI" prepared from exhaustive reaction times (100 min) is shown to possess Ga2I3 and an overall formula of [Ga(0)]2[Ga(+)]2[Ga2I6(2-)], while the "GaI" prepared with the shortest reaction time (40 min) contains GaI2 and has the overall formula [Ga(0)]2[Ga(+)][GaI4(-)]. Intermediate "GaI" samples were consistently shown to be fractionally composed of each of these two preceding formulations and no other distinguishable phases. These "GaI" phases were then shown to give unique products upon reactions with the anionic bis(phosphino)borate ligand class. The reaction of the early-phase "GaI" gives rise to a unique phosphine Ga(II) dimeric coordination compound (3), which was isolated reproducibly in 48% yield and convincingly characterized. A base-stabilized GaI→GaI3 fragment (4) was also isolated using the late-phase "GaI" and characterized by multinuclear NMR spectroscopy and X-ray crystallography. These compounds can be considered unique examples of low-oxidation-state P→Ga coordination compounds and possess relatively long Ga-P bond lengths in the solid-state structures. The anionic borate backbone therefore results in interesting architectures about gallium that have not been observed with neutral phosphines.

  2. An atmospheric pressure chemical ionization-ion-trap mass spectrometer for the on-line analysis of volatile compounds in foods: a tool for linking aroma release to aroma perception.

    Science.gov (United States)

    Le Quéré, Jean-Luc; Gierczynski, Isabelle; Sémon, Etienne

    2014-09-01

    An atmospheric pressure chemical ionization ion-trap mass spectrometer was set up for the on-line analysis of aroma compounds. This instrument, which has been successfully employed for some years in several in vitro and in vivo flavour release studies, is described for the first time in detail. The ion source was fashioned from polyether ether ketone and operated at ambient pressure and temperature making use of a discharge corona pin facing coaxially the capillary ion entrance of the ion-trap mass spectrometer. Linear dynamic ranges (LDR), limits of detection (LOD) and other analytical characteristics have been re-evaluated. LDRs and LODs have been found fully compatible with the concentrations of aroma compounds commonly found in foods. Thus, detection limits have been found in the low ppt range for common flavouring aroma compounds (for example 5.3 ppt (0.82 ppbV) for ethyl hexanoate and 4.8 ppt (1.0 ppbV) for 2,5-dimethylpyrazine). This makes the instrument applicable for in vitro and in vivo aroma release investigations. The use of dynamic sensory techniques such as the temporal dominance of sensations (TDS) method conducted simultaneously with in vivo aroma release measurements allowed to get some new insights in the link between flavour release and flavour perception.

  3. Chemical fingerprint analysis and quantitative determination of steroidal compounds from Dioscorea villosa, Dioscorea species and dietary supplements using UHPLC-ELSD.

    Science.gov (United States)

    Avula, Bharathi; Wang, Yan-Hong; Ali, Zulfiqar; Smillie, Troy J; Khan, Ikhlas A

    2014-02-01

    Ultra high-performance liquid chromatography (UHPLC) with evaporative light scattering detection was used for the quantification of steroidal saponins and diosgenin from the rhizomes or tubers of various Dioscorea species and dietary supplements that were purported to contain Dioscorea. The analysis was performed on an Acquity UPLC™ system with an UPLC™ BEH Shield RP18 column using a gradient elution with water and acetonitrile. Owing to their low UV absorption, the steroidal saponins were observed by evaporative light scattering detection. The 12 compounds could be separated within 15 min using the developed UHPLC method with detection limits of 5-12 µg/mL with 2 μL injection volume. The analytical method was validated for linearity, repeatability, accuracy, limits of detection and limits of quantification. The relative standard deviations for intra- and inter-day experiments were <3.1%, and the recovery efficiency was 97-101%. The total content of standard compounds was found to be in the ranges 0.01-14.5% and 0.9-28.6 mg daily intake for dry plant materials and solid commercial preparations, respectively. UHPLC-mass spectrometry with a quadrupole mass analyzer and ESI source was used only for confirmation of the identity of the various saponins. The developed method is simple, rapid and especially suitable for quality control analysis of commercial products.

  4. Compound medicinal medium of flask liquid fermentation of Poria cocos and its chemical constituents%茯苓摇瓶液体发酵复合药性培养基及其化学成分研究

    Institute of Scientific and Technical Information of China (English)

    李羿; 杨胜; 李晨; 杨万清; 万德光

    2012-01-01

    Objective To screen the optimum compound medicinal medium for flask liquid fermentation of Poria cocos and study the chemical constituents in compound medicinal fermented P. cocos. Methods P. cocos was flask liquid fermented in different compound medicinal media and the exocellular polysaccharide and dry weight of mycelium were detected. The chemical constituents were isolated and detected according to the physicochemical properties. Results The optimum medicinal fermentation medium was adding 0.75% Coicis Semen and Lycii Fructus into fermentation basic medium. In the optimum compound medicinal fermentation medium, the dry weight of P. cocos mycelium was 14.29 g/L and the exocellular polysaccharide was 8.22 g/L. The total polysaccharides, total saccharides, total ashes, and total amino acids in compound medicinal fermented P. cocos were 25.35%, 45.73%, 4.79%, and 21.43%, respectively. Conclusion Different kinds and amounts of traditional Chinese medicinal materials (TCMM) in compound medicinal fermentation medium have various effects on flask liquid fermentations of P. cocos. The chemical constituents in compound medicinal fermented P. cocos are studied to provide a theoretical basis for its industrialization of liquid fermentation.%目的 筛选茯苓摇瓶液体发酵最适复合药性培养基,并对复合药性发酵茯苓的化学成分进行研究.方法 在不同复合药性培养基中进行茯苓摇瓶液体发酵,测定其胞外多糖和菌丝体产量.根据复合药性发酵茯苓化学成分的理化性质进行提取分离和定量测定.结果 在发酵基础培养基中添加0.75%薏苡仁和枸杞子组成最适复合药性培养基,茯苓菌丝体干质量达14.29 g/L,茯苓胞外多糖达8.22 g/L.药性发酵茯苓中总多糖、总糖、总灰分、氨基酸总量分别为25.35%、45.73%、4.79%、21.43%.结论 不同种类和不同数量的中药材组成的复合药性培养基对茯苓摇瓶液体发酵有较大影响,为其液体

  5. 玫瑰花挥发性化学成分的分析研究%Analysis of volatile chemical compounds from the flower of rosa rugosa

    Institute of Scientific and Technical Information of China (English)

    陈红艳; 廖蓉苏; 杨今朝; 宋可珂

    2011-01-01

    利用固相微苹取-气相色谱-质谱联用技术研究北京种植玫瑰鲜花挥发性成分及其相对含量。结果表明:使用聚二甲基硅氧烷-二乙烯基苯纤维苹取头在25℃下萃取30min,能有效地吸附玫瑰花中的挥发性成分,分析其主要挥发性成分为香茅醇(40.38%)、香叶醇(13.49%)、苯乙醇(12.29%)、月桂烯(7.12%)和a-蒎烯(5.65%)等醇类、醚类、酯类以及各种烷烃类化合物,醇类和酯类化合物是主要香气成分。采用水蒸汽蒸馏法和超临界CO2萃取法分别提取玫瑰鲜花精油,经气相色谱质谱法鉴定挥发性化学成分。比较分析3种方法的测定结果,发现提取方法影响精油的品质,水蒸气法提取的精油香气成分更接近玫瑰花自然状态下的“香气”状况。%The constituents and contents of volatile compounds from the flower of rosa rugosa were obtained by solid phase micro-extraction-gas chromatography mass spectrometry (SPME-GC/MS). The results show that the volatile compounds from the flower of rosa rugosa can be effectively extracted by polydimethylsiloxane-divinylbenzene (PDMS! DVB) fiber at 25 % for 30 min. The volatile compounds are alcohols, ethers, esters and some atkanes, mainly including citronellol (40.38%), gerariol (13.49%), alcohol (12.29%), myrcene(7.12%), a-pinene(5.65%), and so on. The volatile compounds from the flower of rosa rugosa were also extracted with water vapor distillation method and carbon dioxide supercritical fluid method, and the constituents and contents of volatile compounds were detected by gas chromatography mass spectrometry(GC/MS). It is found that essential oil extracted from water vapor distillation method is much close to the odours of fresh flower in roses.

  6. Magnitude Differences in Bioactive Compounds, Chemical Functional Groups, Fatty Acid Profiles, Nutrient Degradation and Digestion, Molecular Structure, and Metabolic Characteristics of Protein in Newly Developed Yellow-Seeded and Black-Seeded Canola Lines.

    Science.gov (United States)

    Theodoridou, Katerina; Zhang, Xuewei; Vail, Sally; Yu, Peiqiang

    2015-06-10

    Recently, new lines of yellow-seeded (CS-Y) and black-seeded canola (CS-B) have been developed with chemical and structural alteration through modern breeding technology. However, no systematic study was found on the bioactive compounds, chemical functional groups, fatty acid profiles, inherent structure, nutrient degradation and absorption, or metabolic characteristics between the newly developed yellow- and black-seeded canola lines. This study aimed to systematically characterize chemical, structural, and nutritional features in these canola lines. The parameters accessed include bioactive compounds and antinutrition factors, chemical functional groups, detailed chemical and nutrient profiles, energy value, nutrient fractions, protein structure, degradation kinetics, intestinal digestion, true intestinal protein supply, and feed milk value. The results showed that the CS-Y line was lower (P ≤ 0.05) in neutral detergent fiber (122 vs 154 g/kg DM), acid detergent fiber (61 vs 99 g/kg DM), lignin (58 vs 77 g/kg DM), nonprotein nitrogen (56 vs 68 g/kg DM), and acid detergent insoluble protein (11 vs 35 g/kg DM) than the CS-B line. There was no difference in fatty acid profiles except C20:1 eicosenoic acid content (omega-9) which was in lower in the CS-Y line (P compounds differed (P bioactive compounds, total polyphenols tended to be different (6.3 vs 7.2 g/kg DM), but there were no differences in erucic acid and condensed tannins with averages of 0.3 and 3.1 g/kg DM, respectively. When protein was portioned into five subfractions, significant differences were found in PA, PB1 (65 vs 79 g/kg CP), PB2, and PC fractions (10 vs 33 g/kg CP), indicating protein degradation and supply to small intestine differed between two new lines. In terms of protein structure spectral profile, there were no significant differences in functional groups of amides I and II, α helix, and β-sheet structure as well as their ratio between the two new lines, indicating no difference in

  7. QSPR models based on molecular mechanics and quantum chemical calculations. 1. Construction of Boltzmann averaged descriptors for alkanes, alcohols, diols, ethers and cyclic compounds

    DEFF Research Database (Denmark)

    Dyekjær, Jane Dannow; Rasmussen, Kjeld; Jonsdottir, Svava Osk

    2002-01-01

    Values for nine descriptors for QSPR (quantitative structure-property relationships) modeling of physical properties of 96 alkanes, alcohols, ethers, diols, triols and cyclic alkanes and alcohols in conjunction with the program Codessa are presented. The descriptors are Boltzmann......-averaged by selection of the most relevant conformers out of a set of possible molecular conformers generated by a systematic scheme presented in this paper. Six of these descriptors are calculated with molecular mechanics and three with quantum chemical methods. Especially interesting descriptors are the relative van...

  8. 红树林底泥放线菌( N2010-37)发酵液的化学成分%Chemical Compounds of Actinomycete strain ( N2010-37 ) of Bottom Mud in Mangrove

    Institute of Scientific and Technical Information of China (English)

    周中流

    2011-01-01

    Objective: To study the chemical components of the cultured filaments of an actinomycete strain ( N2010-37 ) . Method: Compounds were isolated and purified by chromatographic techniques and recrystallization, and the structures were identified by spectral methods together with physiochemical analysis. Result: Seven compounds were identified. There were 6, 7-dimethoxy-5, 8-dihydroxylflavone ( Ⅰ ) , 5, 6, 7, 8-tetramethoxyflavone ( Ⅱ ) , P-hydroxybenzonic acid ( Ⅲ ) , P-hydroxybenzaldehyde ( Ⅳ ) , uracil ( Ⅴ ) , adenosine (Ⅵ), daucosterol ( Ⅶ ) . Conclusion: Compounds Ⅰ and Ⅱ were isolated from marine actinomycete for the first time. Compounds Ⅲ-Ⅶ have been isolated from this actinomycete for the first time.%目的:研究红树林底泥放线菌(N2010-37)中化学成分.方法:放线菌(N2010-37)发酵菌丝体经95%乙醇提取,溶剂分级萃取,应用多种柱色谱分离和谱学分析方法对乙酸乙酯萃取部位化学成分进行研究.结果:从乙酸乙酯部位分离得到7个化合物,分别为6,7-二甲氧基-5,8-二羟基黄酮(Ⅰ),5,6,7,8-四甲氧基黄酮(Ⅱ),对羟基苯甲酸(Ⅲ),对羟基苯甲醛(Ⅳ),尿嘧啶(V),腺嘌呤核苷(Ⅵ),胡萝卜苷(Ⅶ).结论:化合物Ⅰ和化合物Ⅱ首次从海洋放线菌次级代谢产物中分离得到,化合物Ⅲ~Ⅶ为首次从该放线菌中分离得到.

  9. Chemical sensor and field screening technology development: Downhole photoionization detection of volatile organic compounds. Topical report, March 1, 1995--March 31, 1996

    Energy Technology Data Exchange (ETDEWEB)

    Schabron, J.F.; Rovani, J.F. Jr.; Moore, D.F.

    1998-12-31

    Western Research Institute conducted a study to define the various parameters that need to be considered in the design and use of a downhole submersible photoionization detector (PID) probe to measure volatile organic compounds (VOCs). Detector response under various conditions, including saturated humidity environments, temperature, and analyte concentration was studied. The relative responses for several VOC analytes were measured. The partitioning of VOCs between water and air was studied as a function of analyte concentration and temperature. The Henry`s law constant governing this partitioning represents an ideal condition at infinite dilution for a particular temperature. The results show that this partitioning is not ideal. Conditions resulting in apparent, practical deviations from Henry`s law include temperature and VOC concentration. Studies with membranes show that membranes that allow passage of VOCs also allow some passage of water vapor. A membrane could play a useful role in protecting the sensor from direct contact with liquid water down hole. A porous poly(tetrafluoroethylene) (PTFE) membrane allows for a rapid passage of VOCs. The rate of diffusion to the sensor with or without a membrane might be a limiting factor for rapid measurements. Various means of mixing may need to be considered.

  10. Development of urine standard reference materials for metabolites of organic chemicals including polycyclic aromatic hydrocarbons, phthalates, phenols, parabens, and volatile organic compounds.

    Science.gov (United States)

    Schantz, Michele M; Benner, Bruce A; Heckert, N Alan; Sander, Lane C; Sharpless, Katherine E; Vander Pol, Stacy S; Vasquez, Y; Villegas, M; Wise, Stephen A; Alwis, K Udeni; Blount, Benjamin C; Calafat, Antonia M; Li, Zheng; Silva, Manori J; Ye, Xiaoyun; Gaudreau, Éric; Patterson, Donald G; Sjödin, Andreas

    2015-04-01

    Two new Standard Reference Materials (SRMs), SRM 3672 Organic Contaminants in Smokers' Urine (Frozen) and SRM 3673 Organic Contaminants in Non-Smokers' Urine (Frozen), have been developed in support of studies for assessment of human exposure to select organic environmental contaminants. Collaborations among three organizations resulted in certified values for 11 hydroxylated polycyclic aromatic hydrocarbons (OH-PAHs) and reference values for 11 phthalate metabolites, 8 environmental phenols and parabens, and 24 volatile organic compound (VOC) metabolites. Reference values are also available for creatinine and the free forms of caffeine, theobromine, ibuprofen, nicotine, cotinine, and 3-hydroxycotinine. These are the first urine Certified Reference Materials characterized for metabolites of organic environmental contaminants. Noteworthy, the mass fractions of the environmental organic contaminants in the two SRMs are within the ranges reported in population survey studies such as the National Health and Nutrition Examination Survey (NHANES) and the Canadian Health Measures Survey (CHMS). These SRMs will be useful as quality control samples for ensuring compatibility of results among population survey studies and will fill a void to assess the accuracy of analytical methods used in studies monitoring human exposure to these organic environmental contaminants.

  11. 大气中碳氮硫化合物光化学反应的化学耦合作用%CHEMICAL COUPLING OF PHOTO-CHEMISTRY OF SOME CARBON NITROGEN SULFUR COMPOUNDS IN THE ATMOSPHERE

    Institute of Scientific and Technical Information of China (English)

    沈济

    2001-01-01

    The mechanism of formation of O3,a typical photo-chemical product,and its chemical coup-ling has been studied with sensitivity analysis under a broad range of atmospheric conditions from remote ocean to heavily polluted area.The influential reactions for formation of O3 are pointed out.Under certain conditions the normalized sensitivity coefficients of O3 concentration with respect to some rate constants which reactions are very important for formation of O3 switch sign.This non-linearity phenomena cause more O3 formed by the chemical coupling of carbon and nitrogen compounds.The chemical coupling of some important photochemical products as O3,HNO3,HCHO,H2O2 with respect to DMS chemistry is weak in the atmosphere.%从遥远海洋到重污染地区,在很宽的大气条件下,用灵敏度分析法研究了光化学典型产物O3的形成机理及其化学耦合作用,指出了影响形成O3的重要反应,在一些条件下,O3浓度对一些重要化学反应的速率常数的归一化灵敏度系数异号,由于碳、氮化合物的化学耦合作用的非线性现象使O3生成增加.大气中一些重要的光化学产物如O3,HNO3,HCHO,H2O2等形成中,DMS的化学耦合是弱耦合

  12. Chemicals for worldwide aquaculture

    Science.gov (United States)

    Schnick, R.A.

    1991-01-01

    Regulations and therapeutants or other safe chemicals that are approved or acceptable for use in the aquaculture industry in the US, Canada, Europe and Japan are presented, discussing also compounds that are unacceptable for aquaculture. Chemical use practices that could affect public health are considered and details given regarding efforts to increase the number of registered and acceptable chemicals.

  13. Mixed 3d/4f polynuclear complexes with 2,2‧-oxydiacetate as bridging ligand: Synthesis, structure and chemical speciation of La M compounds (M = bivalent cation)

    Science.gov (United States)

    Domínguez, Sixto; Torres, Julia; Peluffo, Florencia; Mederos, Alfredo; González-Platas, Javier; Castiglioni, Jorge; Kremer, Carlos

    2007-03-01

    Heterometallic compounds containing La(III), bivalent cations M (M = Co, Ni, Ca), and 2,2‧-oxydiacetate (oda) as connecting ligand have been prepared and characterized. The complexes can be formulated as [La2M3(oda)6(H2O)6] · 12H2O. The structure of [La2Co3(oda)6(H2O)6] shows the presence of the La(III) coordinated by six carboxy and three ether oxygen atoms, and the Co(II) cation bonded to four carboxy oxygens and two molecules of water. An open 3D framework is observed, containing large hexagonal channels. The chemical systems were also investigated in solution (25.0 °C, I = 0.5 M Me4NCl) by potentiometry. The same kind of polynuclear species have been found in aqueous solution.

  14. Biotransformation of endocrine disrupting compounds by selected phase I and phase II enzymes--formation of estrogenic and chemically reactive metabolites by cytochromes P450 and sulfotransferases.

    Science.gov (United States)

    Reinen, J; Vermeulen, N P E

    2015-01-01

    The endocrine system is a major communication system in the body and is involved in maintenance of the reproductive system, fetal development, growth, maturation, energy production, and metabolism,. The endocrine system responds to the needs of an organism by secreting a wide variety of hormones that enable the body to maintain homeostasis, to respond to external stimuli, and to follow various developmental programs. This occurs through complex signalling cascades,with multiple sites at which the signals can be regulated. Endocrine disrupting compounds (EDCs) affect the endocrine system by simulating the action of the naturally produced hormones, by inhibiting the action of natural hormones, by changing the function and synthesis of hormone receptors, or by altering the synthesis, transport, metabolism, and elimination of hormones. It has been established that exposure to environmental EDCs is a risk factor for disruption of reproductive development and oncogenesis in both humans and wildlife. For accurate risk assessment of EDCs, the possibility of bioactivation through biotransformation processes needs to be included since neglecting these mechanisms may lead to undervaluation of adverse effects on human health caused by EDCs and/or their metabolites. This accurate risk assessment should include: (1) possibility of EDCs to be bioactivated into metabolites with enhanced endocrine disruption (ED) effects, and (2) possibility of EDCs to be biotransformed into reactive metabolites that may cause DNA damage. Here, we present an overview of different metabolic enzymes that are involved in the biotransformation of EDCs. In addition, we describe how biotransformation by Cytochromes P450 (CYPs), human estrogen sulfotransferase 1E1 (SULT1E1) and selected other phase II enzymes, can lead to the formation of bioactive metabolites. This review mainly focuses on CYP- and SULT-mediated bioactivation of estrogenic EDCs and summarizes our views on this topic while also showing

  15. 生熟五味子在小青龙汤中化学成分比较%Comparison of raw and processedSchisandra chinensis about chemical compounds in Xiaoqinglong decoction

    Institute of Scientific and Technical Information of China (English)

    高慧; 葛会奇; 张爽; 佟鑫

    2015-01-01

    目的:比较生熟五味子对复方化学成分的影响,为五味子“生熟异用”临床合理用药提供实验依据。方法采用HPLC法,测定小青龙汤中(含生五味子或酒五味子)五味子醇甲、芍药苷的含量。结果小青龙汤(含生五味子)中五味子醇甲、芍药苷的含量分别为0.0524%、0.0152%,小青龙汤(含酒五味子),五味子醇甲、芍药苷的含量分别为0.0502%、0.0146%。结论从化学成分角度能够验证五味子“入嗽药生用”的传统理论。%Objective To provide scientific basis for the research and the clinical applications of "the processedSchisandra chinensis Fruits is different from the raw ones" through comparing the difference about chemical compounds in Xiaoqinglong decoction(contains raw Schisandra chinensis)and Xiaoqinglong decoction (contains processed Schisandra chinensis).Methods To determine schisandrin and paeoniflorin in Xiaoqinglong decoction(contains raw Schisandra chinensisor wine processedSchisandra chinensis) by HPLC. Results The contents of schisandrin and paeoniflorin in Xiaoqinglong decoction which contain rawSchisandra chinensis were0.0524% and 0.0152%; the contents of schisandrin and paeoniflorin in Xiaoqinglong decoction which contain wine Schisandra chinensis were 0.0502% and 0.0146%.ConclusionVerified the traditional theory "rawSchisandra chinensisshould be used in cough" from the chemical compounds of view.

  16. Analysis on changes of chemical compounds in different samples of fried Foeniculum vulgare%民族药小茴香炮制前后化学成分的变化分析

    Institute of Scientific and Technical Information of China (English)

    张帆; 李臻; 田树革; 马丽

    2009-01-01

    Objective: To analysis the changes of chemical compounds in fried Foeniculum vulgare. Method: Cleaned F. vulgare were fried with honey, Pharbitis nil, salt solution, vinegar, wine and bran, respectively, according to different Chinese medicine frying theories. Different volatile ingredints were extracted from fried products, and their contents and physical constants were detected.Gas chromatography-mass spectrometry (GC-MS) was developed for analyzing the changes of chemical compounds in different samplesof fried F. vulgare. Result: The experimental results showed that the content of volatile oil in F. vulgare decreased after been fried.Among these effective ingredients in fried samples, trans-anethole was the ingredient of the maximum content, and the contents of all twenty-four ingredinets had changed. Furthermore, other eighteen compounds were created; Among them, linalylacetate, farnesene,p-allyiphenyl aromatic oxide, menthone, and hexyl octanoate were detected firstly in F. vulgare. Conclusion: GC-MS is effective to fleetly analyse the frying changes of herbs flectly.%目的:研究小茴香经不同方法炮制后化学成分的动态变化.方法:应用不同炮制原理对净制后的小茴香分别进行蜜制、黑牵牛制、"四"制和麸制,使用标准挥发油提取器提取炮制品中挥发油成分,检测其含量和物理常数,并利用毛细管气相色谱-电子轰击质谱联用仪对其进行分析.结果:小茴香经不同辅料炮制后挥发油含量显著降低;炮制前后反式-茴香脑含量均最高,生品中24种化合物经不同方法炮制后含量均发生了变化,且发生了转化,共新产生了18种化合物,其中乙酸里那酯、法尼烯、对-烯苯基芳香醚、薄荷酮和辛酸己酯为首次在小茴香药材中检测到.结论:扩展了气相色谱-质谱联用技术的应用范围,适用于对药材炮制变化的快速分析.

  17. Phenolic Molding Compounds

    Science.gov (United States)

    Koizumi, Koji; Charles, Ted; de Keyser, Hendrik

    Phenolic Molding Compounds continue to exhibit well balanced properties such as heat resistance, chemical resistance, dimensional stability, and creep resistance. They are widely applied in electrical, appliance, small engine, commutator, and automotive applications. As the focus of the automotive industry is weight reduction for greater fuel efficiency, phenolic molding compounds become appealing alternatives to metals. Current market volumes and trends, formulation components and its impact on properties, and a review of common manufacturing methods are presented. Molding processes as well as unique advanced techniques such as high temperature molding, live sprue, and injection/compression technique provide additional benefits in improving the performance characterisitics of phenolic molding compounds. Of special interest are descriptions of some of the latest innovations in automotive components, such as the phenolic intake manifold and valve block for dual clutch transmissions. The chapter also characterizes the most recent developments in new materials, including long glass phenolic molding compounds and carbon fiber reinforced phenolic molding compounds exhibiting a 10-20-fold increase in Charpy impact strength when compared to short fiber filled materials. The role of fatigue testing and fatigue fracture behavior presents some insight into long-term reliability and durability of glass-filled phenolic molding compounds. A section on new technology outlines the important factors to consider in modeling phenolic parts by finite element analysis and flow simulation.

  18. Polybenzimidazole compounds

    Science.gov (United States)

    Klaehn, John R.; Peterson, Eric S.; Wertsching, Alan K.; Orme, Christopher J.; Luther, Thomas A.; Jones, Michael G.

    2010-08-10

    A PBI compound that includes imidazole nitrogens, at least a portion of which are substituted with an organic-inorganic hybrid moiety. At least 85% of the imidazole nitrogens may be substituted. The organic-inorganic hybrid moiety may be an organosilane moiety, for example, (R)Me.sub.2SiCH.sub.2--, where R is selected from among methyl, phenyl, vinyl, and allyl. The PBI compound may exhibit similar thermal properties in comparison to the unsubstituted PBI. The PBI compound may exhibit a solubility in an organic solvent greater than the solubility of the unsubstituted PBI. The PBI compound may be included in separatory media. A substituted PBI synthesis method may include providing a parent PBI in a less than 5 wt % solvent solution. Substituting may occur at about room temperature and/or at about atmospheric pressure. Substituting may use at least five equivalents in relation to the imidazole nitrogens to be substituted or, preferably, about fifteen equivalents.

  19. CALCULATION AND APPLICATION OF ENVIRONMENTAL IMPACT INDEX OF CHEMICAL COMPOUND BASED ON FUZZY OPTIMAL SELECTION THEORY%基于多目标模糊优选理论的化合物环境影响指数确定及应用

    Institute of Scientific and Technical Information of China (English)

    孙力; 贺高红; 樊希山; 姚平经

    2004-01-01

    Environment impact (EI) is a multi- decision-making, multi-objective and multi-criteria system with uncertainties and ambiguities, and environment impact index (EII) of a chemical compound is difficult to calculate appropriately with traditional methods. In this paper, fuzzy optimal selection theory based on the concept of relative importance degree is adopted to determine relativity of the degree of environment impact of chemical compounds as EII, and environment impact assessment (EIA) of a chemical process is done with values of compounds EII to select alternatives that cause less pollution to the environment. It is useful in further process optimization. The paper presents a practical application to the treatment of process condensate in a synthesis ammonia plant to illustrate the procedure, and the calculation result demonstrates the feasibility, practicability, and effectiveness of the suggested method.

  20. Natural compounds with herbicidal activity

    Directory of Open Access Journals (Sweden)

    Pasquale Montemurro

    2011-02-01

    Full Text Available Research about phytotoxic activity of natural compounds could lead both to find new herbicidal active ingredients and to plan environmental friendly weed control strategies. Particularly, living organisms could be a source of compounds that are impossible, for their complexity, to synthesize artificially. More over, they could have alternative sites of action respect to the known chemical herbicides and, due to their origin, they should be more environmental safe. Many living organism, such as bacteria, fungi, insects, lichens and plants, are able to produce bioactive compounds. They generally are secondary metabolites or simply waste molecules. In this paper we make a review about these compounds, highlighting potential and constraints.

  1. Process for compound transformation

    KAUST Repository

    Basset, Jean-Marie

    2016-12-29

    Embodiments of the present disclosure provide for methods of using a catalytic system to chemically transform a compound (e.g., a hydrocarbon). In an embodiment, the method does not employ grafting the catalyst prior to catalysis. In particular, embodiments of the present disclosure provide for a process of hydrocarbon (e.g., C1 to C20 hydrocarbon) metathesis (e.g., alkane, olefin, or alkyne metathesis) transformation, where the process can be conducted without employing grafting prior to catalysis.

  2. NATURAL POLYACETYLENE COMPOUNDS

    Directory of Open Access Journals (Sweden)

    A. M. Nasukhova

    2014-01-01

    Full Text Available In article the review of the initial stage of researches of natural polyacetylene compounds is resulted. The high reactionary ability leading to fast oxidation and degradation of these compounds, especially at influence of Uf-light, oxygen of air, pH and other factors, has caused the serious difficulties connected with an establishment of structure and studying of their physical and chemical properties. Therefore the greatest quantity of works of this stage is connected with studying of essential oils of plants from families Apiaceae, Araliaceae, Asteraceae, Campanulaceae, Olacaceae, Pittosporaceae and Santalaceae where have been found out, basically, diacetylene compounds. About development of physical and chemical methods of the analysis of possibility of similar researches have considerably extended. More than 2000 polyacetylenes are known today, from them more than 1100 are found out in plants fam. Asteraceae. Revolution in the field of molecular biology has allowed to study processes of biosynthesis of these compounds intensively.

  3. Amino acid modifiers in guayule rubber compounds

    Science.gov (United States)

    Tire producers are increasingly interested in biobased materials, including rubber but also as compounding chemicals. An alternative natural rubber for tire use is produced by guayule, a woody desert shrub native to North America. Alternative compounding chemicals include naturally-occurring amino a...

  4. Legendary Chemical Aphrodisiacs.

    Science.gov (United States)

    Waddell, Thomas G.; And Others

    1980-01-01

    Presents a survey of the literature and a summary of information regarding aphrodisiacs. Chemical compounds are discussed as groups of plant natural products, animal natural products, and synthetic products. (CS)

  5. Compostos orgânicos hidrossolúveis de resíduos vegetais e seus efeitos nos atributos químicos do solo Water-soluble organic compounds in plant residue and the effects on soil chemical properties

    Directory of Open Access Journals (Sweden)

    Raquel Cátia Diehl

    2008-12-01

    Full Text Available Compostos orgânicos hidrossolúveis de resíduos vegetais depositados na superfície do solo podem melhorar a fertilidade do subsolo, pela neutralização da acidez e transporte de Ca e Mg. Com o objetivo de avaliar o efeito dos compostos orgânicos hidrossolúveis de materiais vegetais nos atributos químicos de um Latossolo Vermelho distroférrico, foi desenvolvido um experimento no Instituto Agronômico do Paraná (IAPAR, Londrina, com amostras de solo acondicionadas em colunas nas quais se aplicaram os tratamentos: água destilada, calcário incorporado na camada 0-5 cm de profundidade, calcário e percolação com extratos de nabo forrageiro, aveia preta, palha de trigo, milho e soja. No extrato percolado, foram determinados os teores de ligantes orgânicos hidrossolúveis (LOH por potenciometria com eletrodo seletivo de Cu2+; ácidos orgânicos tituláveis (AOT por titulação ácido-base e ânions orgânicos (AO pela soma de bases. As concentrações de AO e AOT variaram de 7,0 a 32,0 mmol L-1 e de LOH de 0,60 a 2,23 mmol L-1. Todos os extratos vegetais aumentaram o pH, os teores de Ca, Mg e K trocável e diminuíram a acidez potencial e o Al trocável até 15 cm de profundidade, enquanto o efeito da calagem sem extrato foi observado somente até 10 cm de profundidade. A concentração de compostos orgânicos solúveis oriundos dos materiais vegetais correlacionou-se com o pH, Al trocável, H+Al e V % do solo na camada de 0-20 cm, confirmando a participação destes na melhoria dos atributos químicos do solo e ação da calagem superficial quando o material vegetal está presente.The water-soluble organic compounds of plant residues released on the soil surface can improve the subsoil fertility, due to the neutralization of acidity and Ca and Mg transport. An experiment was conducted at the Instituto Agronomico do Parana (IAPAR, Londrina, to evaluate the effect of water-soluble organic compounds of plant extracts on the chemical

  6. 复合型缓释肥包衣剂理化性质及缓释特性研究%Studies on Physical and Chemical Properties and Slow- Release Properties of Compound Coating Agent for Slow-Release Fertilizer

    Institute of Scientific and Technical Information of China (English)

    熊海蓉; 钟总; 官春云; 蒋利华; 邹应斌; 熊远福

    2011-01-01

    为了探明复合型缓释肥包表剂的理化性质及其缓释特性,对复合型缓释肥包衣剂的粘度、成膜性、成膜时间、膜韧性、包衣脱落率、包衣肥的养分初期溶出率、养分微分溶出率、养分累积释放曲线等进行了测定.理化性质测试结果显示:缓释肥包衣剂的粘度为44.5 MPa/s、成膜性良好、成膜时间7min、包衣膜拉长倍数达2.8倍,包衣脱落率<5%.缓释特性测试结果显示:包衣肥养分N、P、K初期溶解率<15%、微分溶解率<2%,符合中国缓释肥料标准GB/T23348-2009.其中P的初期溶解率小于N、K的初期溶解率,而N、P、K微分溶解率相差不大.养分累积释放曲线大致呈“S”型,与作物生长需肥规律一致.表明复合型缓释肥包衣剂的理化性质良好,能有效控制普通复合肥养分的缓释.%To explore the physical and chemical properties and slow-release properties of compound coating-agent for slow-release fertilizer (KSFF-2), the viscosity, forming film property, forming film time, film tenacity, coating off rates of coating agent, and the nutrient initial-release ratios, nutrient micro-release ratios and nutrient accumulation-release curves of coating slow-release fertilizer were determined. Results showed that the viscosity of the compound coating-agent was 44.5 Mpa/s, forming film property was better, forming film time was 7 min, film stretch ratio was 2.8 times, coating off rates was less than 5%. The initial release ratio of N, P, K in the coated fertilizer was less than 15%, the micro release ratio was less than 2%, which was consistent with the slow-release fertilizer standard GB/T 23348-2009 constituted by China. The initial dissolution rate of P was less than those of N and K, and the micro release ratio of N, P, K was almost the same. The nutrient accumulation-release curves were S-shape, which was consistent with the nutrient demand of crops. These results indicated the physical and chemical

  7. Effects of Different Compound Chemical Treatments on the Nutritional Value of Crop Straw%复合化学处理提高作物秸秆营养价值的研究

    Institute of Scientific and Technical Information of China (English)

    毛华明; 朱仁俊; 冯仰廉

    2001-01-01

    Improving Effects of Different Compound Chemical Treatments on the Nutritional Value of Crop Straw were studied. The results showed that the content of neutral detergent fiber (NDF) in wheat, oat and rye straw treated with 2.5% urea and 5.0% Ca (OH) 2 and/or pelleting was reduced from 71~81% to 67~75%. The content of crude protein in these treated crop straw was raised from 3.5~ 5.6% to 9.5~11.4% and the in vitro digestibility of organic matter was raised from 38~45% to 57~65%, which is raised by 17.5% and up to or higher than that of northeast sheep fescues and corn straw silage. By these compound treatments, rumen degradability and degrading rate of crop straw were also improved.%麦秸,大麦秸,黑麦秸和稻草经2.5%尿素+5.0%Ca(OH)2复合化学处理并压粒后,中性洗涤纤维(NDF)下降到67%~75%,平均下降6.5个百分点;粗蛋白从3.5%~5.6%提高到9.5%~11.4%,平均提高了一倍多;体外有机物消化率从38%~45%提高到57%~65%,平均提高了17.5个百分点,接近或超过了东北羊草和玉米青贮的水平。复合化学处理还提高了秸秆在瘤胃的降解率和降解速度。

  8. A high-resolution time-of-flight chemical ionization mass spectrometer utilizing hydronium ions (H3O+ ToF-CIMS) for measurements of volatile organic compounds in the atmosphere

    Science.gov (United States)

    Yuan, Bin; Koss, Abigail; Warneke, Carsten; Gilman, Jessica B.; Lerner, Brian M.; Stark, Harald; de Gouw, Joost A.

    2016-07-01

    Proton transfer reactions between hydronium ions (H3O+) and volatile organic compounds (VOCs) provide a fast and highly sensitive technique for VOC measurements, leading to extensive use of proton-transfer-reaction mass spectrometry (PTR-MS) in atmospheric research. Based on the same ionization approach, we describe the development of a high-resolution time-of-flight chemical ionization mass spectrometer (ToF-CIMS) utilizing H3O+ as the reagent ion. The new H3O+ ToF-CIMS has sensitivities of 100-1000 cps ppb-1 (ion counts per second per part-per-billion mixing ratio of VOC) and detection limits of 20-600 ppt at 3σ for a 1 s integration time for simultaneous measurements of many VOC species of atmospheric relevance. The ToF analyzer with mass resolution (m/Δm) of up to 6000 allows the separation of isobaric masses, as shown in previous studies using similar ToF-MS. While radio frequency (RF)-only quadrupole ion guides provide better overall ion transmission than ion lens system, low-mass cutoff of RF-only quadrupole causes H3O+ ions to be transmitted less efficiently than heavier masses, which leads to unusual humidity dependence of reagent ions and difficulty obtaining a humidity-independent parameter for normalization. The humidity dependence of the instrument was characterized for various VOC species and the behaviors for different species can be explained by compound-specific properties that affect the ion chemistry (e.g., proton affinity and dipole moment). The new H3O+ ToF-CIMS was successfully deployed on the NOAA WP-3D research aircraft for the SONGNEX campaign in spring of 2015. The measured mixing ratios of several aromatics from the H3O+ ToF-CIMS agreed within ±10 % with independent gas chromatography measurements from whole air samples. Initial results from the SONGNEX measurements demonstrate that the H3O+ ToF-CIMS data set will be valuable for the identification and characterization of emissions from various sources, investigation of secondary

  9. Multipurpose Compound

    Science.gov (United States)

    1983-01-01

    Specially formulated derivatives of an unusual basic compound known as Alcide may be the answer to effective treatment and prevention of the disease bovine mastitis, a bacterial inflammation of a cow's mammary gland that results in loss of milk production and in extreme cases, death. Manufactured by Alcide Corporation the Alcide compound has killed all tested bacteria, virus and fungi, shortly after contact, with minimal toxic effects on humans or animals. Alcide Corporation credits the existence of the mastitis treatment/prevention products to assistance provided the company by NERAC, Inc.

  10. A New Compound from Swertia cincta

    Institute of Scientific and Technical Information of China (English)

    Wen-xing Liu; Qian Tian; Cui Yang; Hai-yan Wu; Shang-xiu Li; Gan-peng Li

    2016-01-01

    Objective To study the chemical constituents from the whole plant of Swertia cincta.Methods The chemical constituents were purified by chromatographic methods such as silica gel column and Sephadex LH-20.The structures of these compounds were elucidated by MS,IR,and NMR analyses.Results Two compounds were isolated from S.cincta.Conclusion Compound 1 is a new compound named swercinctlactone A.Compound 2 is identified as (±)-gentiolactone and its configuration is confirmed by single crystal X-ray diffraction and optical specific rotation.

  11. Analysis on major chemical compounds in exocarp of Juglans mandshurica based on UPLC-Q-TOF/MS%基于UPLC-Q-TOF/MS分析北青龙衣成分

    Institute of Scientific and Technical Information of China (English)

    霍金海; 都晓伟; 孙国东; 张海燕; 王伟明

    2016-01-01

    目的 采用超高效液相色谱-四极杆飞行时间质谱(UPLC-Q-TOF/MS)联用技术,对不同产地78批次北青龙衣进行分析,确定其主要的活性组分.方法 采用Waters Acquity UPLC BEH C18色谱柱(100 mm×2.1mm,1.7μm),以0.1%甲酸水(A)-0.1%甲酸乙腈(B)为流动相梯度洗脱;质谱采用电喷雾(ESI)离子源,在正离子模式下采集数据,通过Markerview1.2.1软件提取78个样本中1 000个离子,按离子在所有样本中均出现,且相对强度基本大于e4的原则选取共有离子.通过Peakview 2.0/masterview1.0软件,依据精确质量数和同位素峰度比确定共有离子分子式,通过对照品及数据库的二级谱图比对、裂解规律分析,结合已有文献报道,确定共有离子结构式.结果 鉴定或推断了北青龙衣中31种主要化学成分,其中包括11种萘醌类、3种二芳基庚烷、3种黄酮、8种三萜类及6个其他类化合物.结论该方法检测快速、准确,为北青龙衣的化学成分鉴定提供一种新的策略,主要化学成分的确定为北青龙衣质量评价指标选择及药效物质深入研究奠定基础.%Objective To identify the major chemical compounds in 78 batches of the exocarp ofduglans mandshurica from different origins by ultra performance liquid chromatography coupled with time-of-fight mass spectrometry (UFLC-Q-TOF/MS) and determine the major active chemical components.Methods The separation was performed on Waters Acquity UPLC BEH C18 column (100 mm × 2.1 mm,1.7 μm),with a mobile phase using water with 0.1% formic acid (A) and acetonitrile with 0.1% formic acid (B) for gradient elution;Q-TOF/MS and electrospray ion (ESI) source were applied for the analysis under the positive ion mode;One thousand ions were extracted through Markerview 1.2.1 software from 78 batches.And common ions (compounds) were selected according to the following principles:One ion can be detected in all samples,and the relative strength is greater than the e4

  12. 某水电站f18断层水泥+化学浆液复合灌浆施工%Compound grouting using cement+ chemical slurry for the f18 fault of a hydropower station

    Institute of Scientific and Technical Information of China (English)

    贡建兵; 李焰

    2014-01-01

    某水电站一断层贯穿坝基上下游,在河床上游与水库联系,且断层及下盘煌斑岩脉岩体破碎、性状差,在水库运行期长期高压水渗透作用下,可能发生逐渐软化、泥化现象,形成渗漏通道,导致坝体局部开裂。为了提高该断层的抗渗、抗变形能力等,在断层区域布置了水泥+化学浆液灌浆孔进行复合灌浆补强处理。介绍了灌浆施工技术及类似工程可以借鉴的工艺方法。%A fault penetrates the dam foundation and connects reservoir at the upstream river bed. As the broken rock and poor performance of the fault and the lamprophyre underneath, argillization and soft-ening may occur with long-term seepage of high-pressure water. This may form a seepage passage in-side the dam body and cause cracks. To improve the resistance of seepage and deformation of the fault, compound grouting using cement+chemical slurry was carried out. This paper introduced the grouting construction, for reference.

  13. Variación de compuestos químicos en hojas de poblaciones de Drimys spp. (Magnoliophyta: Winteraceae en Chile Variation of chemical compounds in leaves of Drimys spp. (Magnoliophyta: Winteraceae populations in Chile

    Directory of Open Access Journals (Sweden)

    DIEGO MUÑOZ-CONCHA

    2004-03-01

    Full Text Available El canelo (Drimys winteri es un árbol nativo de Chile con propiedades medicinales y sagrado para el pueblo mapuche. Se ha descrito en esta especie la presencia de compuestos químicos con actividad biológica como aceites esenciales, terpenos y flavonoides. Estos grupos de compuestos fueron cuantificados en hojas de cinco poblaciones de D. winteri y una de D. andina de Chile mediante hidrodestilación (aceites volátiles, extracción Soxhlet con hexano (terpenos y espectrofotometría (flavonoides. El contenido promedio de aceites esenciales fue de 0,5 mL 100 g-1, el de terpenos de 7,1 %, y el de flavonoides de 1,8 %, en base a peso seco. A pesar de las importantes variaciones observadas dentro y entre poblaciones, las diferencias de poblaciones fueron significativas para los tres grupos de compuestos estudiados. Las poblaciones de la Séptima Región de Chile presentaron los valores más altos de aceites esenciales (0,68 mL 100 g-1 en la población de Huerta de Maule, terpenos y flavonoides (9,47 y 2,37 %, respectivamente, ambos en la población de Pangal. La población más austral estudiada, ubicada en Huillinco, Chiloé, presentó valores significativamente más bajos para los tres grupos de compuestos: 0,22 ml/100g de aceites esenciales, 3,36 % de terpenos y 1,21 % de flavonoides. Las poblaciones de D. winteri y D. andina de la IX Región, cercanas geográficamente, presentaron diferentes contenidos de aceites esenciales y flavonoides. Se concluye que efectivamente poblaciones distintas de especies de Drimys poseen cantidades significativamente diferentes de aceites esenciales, terpenos y flavonoidesCanelo (Drimys winteri is a Chilean native tree with medicinal properties and sacred to mapuche people. This species contains chemical compounds with biological activity such as: essential oils, terpenes and flavonoids, which were quantified in leaves of five D. winteri and one D. andina populations by hydrodistillation (essential oils, hexane

  14. Prospecção química de compostos produzidos por Senna alata com atividade alelopática Chemical prospecting of compounds produced by Senna alata with allelopathic activity

    Directory of Open Access Journals (Sweden)

    I.M.C. Rodrigues

    2010-01-01

    Full Text Available Senna alata é uma espécie daninha frequente em pastagens da região amazônica. Suas folhas apresentam propriedades medicinais capazes de influenciar a germinação e o desenvolvimento de outras plantas. Objetivou-se neste estudo a prospecção química e a avaliação da atividade alelopática dos compostos presentes nas folhas de S. alata. O material vegetal foi seco, triturado e submetido à extração exaustiva, com solução água:metanol (3:7. O extrato obtido foi então fracionado por coluna cromatográfica por via úmida. As frações mais puras foram submetidas à espectroscopia de Ressonância Magnética Nuclear, para determinação das fórmulas estruturais das moléculas. Na avaliação dos efeitos das substâncias químicas isoladas, utilizaram-se as concentrações de 50, 100, 150 e 200 ppm, tendo como eluente solução hidrometanólica (3:7 v/v. As frações foram adicionadas em placas de Petri e seus efeitos avaliados sobre a germinação de sementes e o alongamento da radícula e hipocótilo de três espécies daninhas de áreas de pastagens: Mimosa pudica, Senna obtusifolia e a própria S. alata. Os compostos com atividade alelopática encontrados em folhas de S. alata pertencem à classe dos flavonoides glicosilados, cujo núcleo aromático é um kaempferol, e causaram maior inibição sobre o crescimento da radícula e sobre a germinação de S. obtusifolia e M. pudica. Já os efeitos autotóxicos desse composto são pouco significativos para o desenvolvimento da plântula e nulos sobre a germinação.Senna alata is a weed species frequently found in pastures of the Amazonian region and whose leaves have medicinal properties. This study aimed to carry out a chemical prospecting and evaluation of the allelopathic activity of the compounds present in S. alata leaves. The plant material was dried, ground, and submitted to exhaustive extraction with water/methanol (3:7 solution. The crude extract obtained was fractioned by wet

  15. 番茄育苗基质理化特性及其对幼苗生长影响研究%Study on physical and chemical characteristics of compound substrate and effects on the growth of tomato seedling

    Institute of Scientific and Technical Information of China (English)

    王鹏勃; 李建明; 丁娟娟; 刘国英; 杜清洁; 潘铜华; 常毅博

    2014-01-01

    Spent mushroom compost,cow dung and perlite were composed to five kinds of compound substrate,tak-ing internationally best formula substrate (peat∶perlite=2∶1)as CK and tomato cv .Xinong No .201 1 as the test plant, the physical and chemical characteristics of compound substrate and growth of tomato seedling were investigated and the physical and chemical characteristics of substrate and seedling index of tomato was carried out path analysis and multiple regression analysis,moreover,we optimized the formula that was preliminary screened by test .This study indicated that the morphological trait,dry matter,root-shoot ratio and seedling index of optimizing formulating(spent mush∶cow dung∶perlite=3∶3∶4)are significantly higher than CK and preliminary optimum formula;the main factors of affecting the seedling index of tomato seedling were bulk density,total porosity,aeration porosity and water holding capacity,the di-rect path coefficient of aeration porosity on tomato seedling is 2 .2992,and influence of other factors on seedling index was negative .Incresing aeration porosity of compound substrate and decreasing bulk density,total porosity and water holding capacity are benefit the breeding of healthy tomato seedling .In order to produce good seedlings we can increase the dosage of cow dung and decrease the dosage of mushroom compost in this study .%将腐熟的菇渣、发酵牛粪和珍珠岩混配形成不同体积比的5种复合基质,以传统的优势配方(草炭∶珍珠岩=2∶1)为对照,以番茄品种“西农2011”为试材,分析了不同配方复合基质的理化性质及其对番茄幼苗生长的影响;同时以复合基质的理化性质为自变量,以番茄幼苗的壮苗指数为因变量进行了多元回归分析和通径分析,最后对初步筛选的最优配方进行再优化试验。结果表明:优化配方菇渣∶牛粪∶珍珠岩=3∶3∶4处理的番茄幼苗质量显著优于对照以及初步筛

  16. Chemical warfare in freshwater

    NARCIS (Netherlands)

    Mulderij, Gabi

    2006-01-01

    Aquatic macrophytes can excrete chemical substances into their enviroment and these compounds may inhibit the growth of phytoplankton. This process is defined as allelopathy: one organism has effects on another via the excretion of a (mixture of) chemical substance(s). With laboratory and field expe

  17. Existing chemicals: international activities.

    Science.gov (United States)

    Purchase, J F

    1989-01-01

    The standards of care used in the protection of the health and safety of people exposed to chemicals has increased dramatically in the last decade. Standards imposed by regulation and those adopted by industry have required a greater level of knowledge about the hazards of chemicals. In the E.E.C., the 6th amendment of the dangerous substances directive imposed the requirement that al new chemicals should be tested according to prescribed programme before introduction on to the market. The development of a European inventory of existing chemicals was an integral part of the 6th amendment. It has now become clear that increased standards of care referred to above must be applied to the chemicals on the inventory list. There is, however, a considerable amount of activity already under way in various international agencies. The OECD Chemicals Programme has been involved in considering the problem of existing chemicals for some time, and is producing a priority list and action programme. The International Programme on Chemical Safety produces international chemical safety cards, health and safety guides and environmental health criteria documents. The international register of potentially toxic compounds (part of UNEP) has prepared chemical data profiles on 990 compounds. The International Agency for Research on Cancer prepared monographs on the carcinogenic risk of chemicals to man. So far 42 volumes have been prepared covering about 900 substances. IARC and IPCS also prepare periodic reports on ongoing research on carcinogenicity or toxicity (respectively) of chemicals. The chemical industry through ECETOC (the European Chemical Industry Ecology and Toxicology Centre) has mounted a major initiative on existing chemicals. Comprehensive reviews of the toxicity of selected chemicals are published (Joint Assessment of Commodity Chemicals). In its technical report no. 30 ECETOC lists reviews and evaluations by major national and international organisations, which provides

  18. Intermetallic Compounds

    Science.gov (United States)

    Takagiwa, Y.; Matsuura, Y.; Kimura, K.

    2014-06-01

    We have focused on the binary narrow-bandgap intermetallic compounds FeGa3 and RuGa3 as thermoelectric materials. Their crystal structure is FeGa3-type (tetragonal, P42/ mnm) with 16 atoms per unit cell. Despite their simple crystal structure, their room temperature thermal conductivity is in the range 4-5-W-m-1-K-1. Both compounds have narrow-bandgaps of approximately 0.3-eV near the Fermi level. Because their Seebeck coefficients are quite large negative values in the range 350-FeGa3 and RuGa3 as n and p-type materials. The dimensionless figure of merit, ZT, was significantly improved by substitution of Sn for Ga in FeGa3 (electron-doping) and by substitution of Zn for Ga in RuGa3 (hole-doping), mainly as a result of optimization of the electronic part, S 2 σ.

  19. Compound odontoma

    Directory of Open Access Journals (Sweden)

    Monica Yadav

    2012-01-01

    Full Text Available Odontomas have been extensively reported in the dental literature, and the term refers to tumors of odontogenic origin. Though the exact etiology is still unknown, the postulated causes include: local trauma, infection, inheritance and genetic mutation. The majority of the lesions are asymptomatic; however, may be accompanied with pain and swelling as secondary complaints in some cases. Here, we report a case of a compound odontome in a 14 year old patient.

  20. Organic Compounds

    Science.gov (United States)

    Shankland, Kenneth

    For many years, powder X-ray diffraction was used primarily as a fingerprinting method for phase identification in the context of molecular organic materials. In the early 1990s, with only a few notable exceptions, structures of even moderate complexity were not solvable from PXRD data alone. Global optimisation methods and highly-modified direct methods have transformed this situation by specifically exploiting some well-known properties of molecular compounds. This chapter will consider some of these properties.

  1. The Standard Chemical-Thermodynamic Properties of Phosphorus and Some of its Key Compounds and Aqueous Species: An Evaluation of Differences between the Previous Recommendations of NBS/NIST and CODATA

    Energy Technology Data Exchange (ETDEWEB)

    Rard, J A; Wolery, T J

    2007-01-30

    The aqueous chemistry of phosphorus is dominated by P(V), which under typical environmental conditions (and depending on pH and concentration) can be present as the orthophosphate ions H{sub 3}PO{sub 4}{sup 0}(aq), H{sub 2}PO{sub 4}{sup -}(aq), HPO{sub 4}{sup 2-}(aq), or PO{sub 4}{sup 3-}(aq). Many divalent, trivalent, and tetravalent metal ions form sparingly soluble orthophosphate phases that, depending on the solution pH and concentrations of phosphate and metal ions, can be solubility limiting phases. Geochemical and chemical engineering modeling of solubilities and speciation requires comprehensive thermodynamic databases that include the standard thermodynamic properties for the aqueous species and solid compounds. The most widely used sources for standard thermodynamic properties are the NBS (now NIST) Tables (from 1982 and earlier; with a 1989 erratum) and the final CODATA evaluation (1989). However, a comparison of the reported enthalpies of formation and Gibbs energies of formation for key phosphate compounds and aqueous species, especially H{sub 2}PO{sub 4}{sup -}(aq) and HPO{sub 4}{sup 2-}(aq), shows a systematic and nearly constant difference of 6.3 to 6.9 kJ {center_dot} mol{sup -1} per phosphorus atom between these two evaluations. The existing literature contains numerous studies (including major data summaries) that are based on one or the other of these evaluations. In this report we examine and identify the origin of this difference and conclude that the CODATA evaluation is more reliable. Values of the standard entropies of the H{sub 2}PO{sub 4}{sup -}(aq), HPO{sub 4}{sup 2-}(aq), and PO{sub 4}{sup 3-}(aq) ions at 298.15 K and p{sup o} = 1 bar were re-examined in the light of more recent information and data not considered in the CODATA review, and a slightly different value of S{sub m}{sup o}(H{sub 2}PO{sub 4}{sup -}, aq, 298.15 K) = 90.6 {+-} 1.5 J {center_dot} K{sup -1} mol{sup -1} was obtained.

  2. Complex chemistry with complex compounds

    Directory of Open Access Journals (Sweden)

    Eichler Robert

    2016-01-01

    Full Text Available In recent years gas-phase chemical studies assisted by physical pre-separation allowed for the investigation of fragile single molecular species by gas-phase chromatography. The latest success with the heaviest group 6 transactinide seaborgium is highlighted. The formation of a very volatile hexacarbonyl compound Sg(CO6 was observed similarly to its lighter homologues molybdenum and tungsten. The interactions of these gaseous carbonyl complex compounds with quartz surfaces were investigated by thermochromatography. Second-generation experiments are under way to investigate the intramolecular bond between the central metal atom of the complexes and the ligands addressing the influence of relativistic effects in the heaviest compounds. Our contribution comprises some aspects of the ongoing challenging experiments as well as an outlook towards other interesting compounds related to volatile complex compounds in the gas phase.

  3. Chemical carcinogenesis

    Directory of Open Access Journals (Sweden)

    Paula A. Oliveira

    2007-12-01

    Full Text Available The use of chemical compounds benefits society in a number of ways. Pesticides, for instance, enable foodstuffs to be produced in sufficient quantities to satisfy the needs of millions of people, a condition that has led to an increase in levels of life expectancy. Yet, at times, these benefits are offset by certain disadvantages, notably the toxic side effects of the chemical compounds used. Exposure to these compounds can have varying effects, ranging from instant death to a gradual process of chemical carcinogenesis. There are three stages involved in chemical carcinogenesis. These are defined as initiation, promotion and progression. Each of these stages is characterised by morphological and biochemical modifications and result from genetic and/or epigenetic alterations. These genetic modifications include: mutations in genes that control cell proliferation, cell death and DNA repair - i.e. mutations in proto-oncogenes and tumour suppressing genes. The epigenetic factors, also considered as being non-genetic in character, can also contribute to carcinogenesis via epigenetic mechanisms which silence gene expression. The control of responses to carcinogenesis through the application of several chemical, biochemical and biological techniques facilitates the identification of those basic mechanisms involved in neoplasic development. Experimental assays with laboratory animals, epidemiological studies and quick tests enable the identification of carcinogenic compounds, the dissection of many aspects of carcinogenesis, and the establishment of effective strategies to prevent the cancer which results from exposure to chemicals.A sociedade obtém numerosos benefícios da utilização de compostos químicos. A aplicação dos pesticidas, por exemplo, permitiu obter alimento em quantidade suficiente para satisfazer as necessidades alimentares de milhões de pessoas, condição relacionada com o aumento da esperança de vida. Os benefícios estão, por

  4. Quantification Assessment of the Relationship Between Chemical and Olfactory Concentrations for Malodorous Volatile Organic Compounds%城市污水处理厂恶臭挥发性有机物的感官定量评价研究

    Institute of Scientific and Technical Information of China (English)

    刘舒乐; 王伯光; 何洁; 唐小东; 赵德骏; 郭薇

    2011-01-01

    Using self-made cold-traps and gas bags,the odor samples were collected from 6 sewage treatment workshops of a typical municipal sewage treatment plant in Guangzhou City.The chemical composition and olfactory concentrations of these samples were respectively analyzed by thermal-desorption/GC-MS and triangle odor bag method.Finally,a mathematical equation was built for assessing the relationship between principal organic odorants and the olfactory concentrations.The result showing that: ①More than 70 volatile organic compounds were detected in municipal sewage treatment plant,among which were 30 malodorous volatile organic compounds(MVOCs),ranging from 0.37 to 1 872.24 μg·m-3 and appearing in sludge dewatering,thickening and aeration tank with the highest concentrations.②Principle component analysis was used to group the target MVOCs into 5 categories: benzenes,halohydrocarbons,aldehydes,hydrocarbons and S,N-containing organic compounds.③Multiple lineal regression analysis was used to build a quantified relationship between chemical and olfactory concentrations of MVOCs.The result indicated that 25% of the odor problem of sewage treatment unit was due to MVOCs.The predicted values were fitting well with measured values.The sensitivity of mathematical equation for measuring odor concentration was higher than that of human olfactory system.%采用自制低温吸附装置和臭气袋采集了广州典型城市污水厂6个处理车间的空气样品.应用热解析/气相色谱-质谱联用仪分析恶臭挥发性有机物的组成和含量,参照国标的三点比较式臭袋法测量样品的恶臭浓度,并针对恶臭挥发性有机物进行感官定量评价.结果表明,①城市污水处理厂检测出烷烃、烯烃、芳香烃等7大类共70种挥发性有机物,其中30种属于恶臭挥发性有机物,它们的浓度范围为0.37~1 872.24μg.m-3,在污泥脱水、污泥浓缩和曝气池最高;②主成分分析可以将主要恶臭挥发

  5. Students' Categorizations of Organic Compounds

    Science.gov (United States)

    Domin, Daniel S.; Al-Masum, Mohammad; Mensah, John

    2008-01-01

    Categorization is a fundamental psychological ability necessary for problem solving and many other higher-level cognitive tasks. In organic chemistry, students must establish groupings of different chemical compounds in order not only to solve problems, but also to understand course content. Classic models of categorization emphasize similarity as…

  6. Variabilidade química de compostos orgânicos voláteis e semivoláteis de populações nativas de Maytenus ilicifolia Chemical variability of volatile and semi-volatile organic compounds in native populations of Maytenus ilicifolia

    Directory of Open Access Journals (Sweden)

    Altemir José Mossi

    2010-01-01

    Full Text Available This work is focused on the chemical distribution of volatile and semi-volatile compounds of 18 native populations of Maytenus ilicifolia collected all over Brazil. The extracts of bulk samples (30 plants of each population were obtained by supercritical CO2 extraction technique, and analyzed by GC/MS. The quantification of compounds (phytol, squalene, vitamin E, limonene, stigmasterol, friedelan-3-ol, friedelin, fridelan-3-one, palmitic acid and geranyl acetate showed significant variations within the different populations, which could be related tom microclimate characteristics.

  7. Magnesium compounds

    Science.gov (United States)

    Kramer, D.A.

    2012-01-01

    Seawater and natural brines accounted for about 57 percent of magnesium compounds produced in the United States in 2011. Dead-burned magnesia was produced by Martin Marietta Magnesia Specialties LLC from well brines in Michigan. Caustic-calcined magnesia was recovered from seawater by Premier Magnesia LLC in Florida, from well brines in Michigan by Martin Marietta and from magnesite in Nevada by Premier Magnesia. Intrepid Potash Wendover LLC and Great Salt Lake Minerals Corp. recovered magnesium chloride brines from the Great Salt Lake in Utah. Magnesium hydroxide was produced from seawater by SPI Pharma Inc. in Delaware and Premier Magnesia in Florida, and by Martin Marietta from its brine operation in Michigan.

  8. Modern Chemical Technology, Volume 5.

    Science.gov (United States)

    Pecsok, Robert L., Ed.; Chapman, Kenneth, Ed.

    This volume contains chapters 26-31 for the American Chemical Society (ACS) "Modern Chemical Technology" (ChemTeC) instructional material intended to prepare chemical technologists. Chapter 26 reviews oxidation and reduction, including applications in titrations with potassium permanganate and iodometry. Coordination compounds are…

  9. Compounds in food packaging materials

    DEFF Research Database (Denmark)

    Rosenmai, Anna Kjerstine

    Food contact materials (FCMs) are sources of food contamination and human chemical exposure. Some chemicals in these materials are known to cause adverse effects, but many are poorly characterized for their potential toxicological hazards making risk assessment a challenge. The aim of the project....... It is recommended to test more FCMs of paper and board with the strategy to obtain information on other potentially problematic compounds present in these materials. The presented data overall suggest that some compounds present in FCMs or suspected of being used can exert endocrine activities in vitro, though...... the implications of these findings with respect to effects in humans and exposure to humans remain largely unknown. Nevertheless, it is of concern that so many of the materials and compounds led to effects and calls for further studies to be conducted. The data obtained in this PhD can be used as a prioritization...

  10. atmospheric volatile organic compounds

    Directory of Open Access Journals (Sweden)

    A. R. Koss

    2016-07-01

    organic compounds (VOCs that cannot be ionized with H3O+ ions (e.g., in a PTR-MS or H3O+ CIMS instrument. Here we describe the adaptation of a high-resolution time-of-flight H3O+ CIMS instrument to use NO+ primary ion chemistry. We evaluate the NO+ technique with respect to compound specificity, sensitivity, and VOC species measured compared to H3O+. The evaluation is established by a series of experiments including laboratory investigation using a gas-chromatography (GC interface, in situ measurement of urban air using a GC interface, and direct in situ measurement of urban air. The main findings are that (1 NO+ is useful for isomerically resolved measurements of carbonyl species; (2 NO+ can achieve sensitive detection of small (C4–C8 branched alkanes but is not unambiguous for most; and (3 compound-specific measurement of some alkanes, especially isopentane, methylpentane, and high-mass (C12–C15 n-alkanes, is possible with NO+. We also demonstrate fast in situ chemically specific measurements of C12 to C15 alkanes in ambient air.

  11. The Industrial Reduction of Aromatic Nitro Compounds.

    Science.gov (United States)

    Gilbert, G.

    1980-01-01

    Describes methods for enriching an A-level chemistry course with a series of chemical company visits. The rationale is discussed for an emphasis of the visits on the industrial reduction of aromatic nitro compounds. (CS)

  12. Potencial herbicida da biomassa e de substâncias químicas produzidas pelo fungo endofítico Pestalotiopsis guepinii Herbicide potential of the biomass and chemical compounds produced by the fungus Pestalotiopsis guepinii

    Directory of Open Access Journals (Sweden)

    L.S. Santos

    2008-01-01

    .Many of the chemical compounds found in nature that are produced by plants or microorganisms can offer new and efficient ways of controlling pests in agriculture and agricultural practice, with the help of fungi. The objective of this work is to characterize the inhibitory potential for seed germination and the plantlet development of two weed species using extracts and compounds obtained from biomass produced by Pestalotiopsis guepinii, an endophytic fungus of the species Virola michelii. The bioassays were developed under controlled conditions at 25 ºC and 12-hour photoperiod for germination, and at 25 ºC and 12-hour photoperiod for root and hypocotyl development. The crude extracts were analyzed at a concentration of 1.0% (m/v. The results showed that the more polar extracts (MeOH-1 and MeOH-2 have the highest inhibitory potential, although the hexane and ethyl acetate extract effects were important, especially for seed germination. Comparatively, weed seed germination was more sensitive to the effects than plantlet development. Mimosa pudica was more affected by the inhibitory effects of the extracts. However, for seed germination of Senna obtusifolia, the extract MeOH-1 showed 100% inhibition. The compounds ergosterol and ergosterol peroxide showed an inhibitory potential always below 35%, not showing the inhibitory potential of the hexane extract from which they were isolated. When these compounds were tested together, little increase was observed in the inhibitory activity.

  13. Crystallographic properties of fertilizer compounds

    Energy Technology Data Exchange (ETDEWEB)

    Frazier, A.W.; Dillard, E.F.; Thrasher, R.D.; Waerstad, K.R.; Hunter, S.R.; Kohler, J.J.; Scheib, R.M.

    1991-02-01

    This bulletin is a compilation of crystallographic data collected at NFERC on 450 fertilizer-related compounds. In TVA's fertilizer R and D program, petrographic examination, XRD, and infrared spectroscopy are combined with conventional chemical analysis methods in identifying the individual compounds that occur in fertilizer materials. This handbook brings together the results of these characterization studies and supplemental crystallographic data from the literature. It is in one-compound-per-page, loose-leaf format, ordered alphabetically by IUPAC name. Indexes provided include IUPAC name, formula, group, alternate formula, synonyms, x-ray data, optical data. Tables are given for solids, compounds in commercial MAP and DAP, and matrix materials in phosphate rock.

  14. OCCURRENCE & CHEMISTRY OF ORGANIC COMPOUNDS IN HANFORD SITE WASTE TANKS

    Energy Technology Data Exchange (ETDEWEB)

    STOCK, L.M.; MEACHAM, J.E.

    2004-07-29

    Volatile and semivolatile organic compounds continuously evolve from the waste tanks at the Hanford Site. Some are identical to the compounds originally transferred to tanks and others are formed through interdependent chemical and radiolytic reactions. This document provides a technical basis for understanding the chemical consequences of long term storage, sluicing, the addition of chemicals, and the prediction of other organic compounds that may be present in the wastes.

  15. 化学复合沉积镍磷-碳纤维的性能研究%Research on Compound Chemical Plating Technique of Nickel-Phosphorus Alloy and Carbon Fiber

    Institute of Scientific and Technical Information of China (English)

    刘秉余; 穆柏椿; 由向群

    2001-01-01

    研究了镀液纤维浓度对镀层纤维含量的影响规律,探讨了碳纤维提高Ni-P合金复合镀层的硬度和耐磨性的机理。结果表明,镀层碳纤维含量随镀液碳纤维浓度的增加先提高后降低,当镀液中碳纤维含量为6g/L时,镀层中碳纤维含量达到最高值(24.1%,体积分数)。碳纤维的加入使镀层硬度和耐磨性显著提高,镀态下和经400℃×1h时效处理后的镀层硬度分别为634HV和1319HV,比同一状态下Ni-P镀层的硬度分别高35%和61%;500℃×1h时效后的耐磨性是Ni-P镀层的6倍,是38CrMoAl钢氮碳共渗层的7倍。%The effects of compound chemical plating technique of nickel-phosphorus alloy and carbon fiber content in the solution on the hardness and wear resistance of coating are researched.The results show that the carbon fiber content in coating increases first,then decreases with the carbon fiber density in solution.When the carbon fiber density is 6g/L,the carbon fiber content in coating reach to a maximun (24.1%,vol.).The hardness of the coatings with carbon fiber in as-coated and aged in 400 ℃×1h is 434HV and 1319HV respectively,35% and 61% higher than that of Ni-P coating in the same state.After 500℃×1h aging,the wear resistance of coating with carbon fiber is over 6 times as that of normal nickel-phosphorus alloy coating and 7 times as that of nitrocarburized case of steel 38CrMoAl.The mechanism of carbon fiber and the wear resistance are also explored.

  16. Composição química e compostos bioativos presentes na polpa e na amêndoa do pequi (Caryocar brasiliense, Camb. Chemical composition and bioactive compounds in the pulp and almond of pequi fruit

    Directory of Open Access Journals (Sweden)

    Alessandro de Lima

    2007-01-01

    Full Text Available O conhecimento da composição química dos alimentos é fundamental para se avaliarem a disponibilidade de nutrientes e o seu consumo por populações. Neste trabalho, o pequi (Caryocar brasiliense, Camb. foi caracterizado pela composição centesimal e pela presença de compostos bioativos na polpa e na amêndoa. Os dados do perfil lipídico mostram alto teor de lípides tanto na polpa quanto na amêndoa, destacando-se nos mesmos a presença dos ácidos graxos insaturados, predominando o ácido oléico como principal componente entre os ácidos graxos. Foi observada também a relação entre os elevados teores de ácidos graxos insaturados com os compostos fenólicos e carotenóides presentes, tendo a polpa quantidades mais expressivas dessas substâncias quando comparada à amêndoa, além de conter uma quantidade superior de fibra alimentar. Os resultados obtidos abrem a perspectiva de se utilizar o pequi como fruto que apresenta, na sua composição, compostos importantes para a formulação de uma dieta saudável.The knowledge of the chemical composition of foods is basic for evaluate the nutrients availability and its consumption for the population. In this work, the pulp and the almond of pequi fruit (Caryocar brasiliense, Camb. were characterized by the centesimal composition and the presence of nutrients. The results showed high amount of lipids and in the fatty acids profile, the oleic fatty acid was the main component. The presence between high unsaturated fatty acids and antioxidant compounds (phenolic acids and carotenoids was correlated with the fruit protection. In the pulp was observed too high amount of alimentary fiber. These results are suggesting the pequi utilization in a healthful diet preparation.

  17. Membrane rejection of nitrogen compounds

    Science.gov (United States)

    Lee, S.; Lueptow, R. M.

    2001-01-01

    Rejection characteristics of nitrogen compounds were examined for reverse osmosis, nanofiltration, and low-pressure reverse osmosis membranes. The rejection of nitrogen compounds is explained by integrating experimental results with calculations using the extended Nernst-Planck model coupled with a steric hindrance model. The molecular weight and chemical structure of nitrogen compounds appear to be less important in determining rejection than electrostatic properties. The rejection is greatest when the Donnan potential exceeds 0.05 V or when the ratio of the solute radius to the pore radius is greater than 0.8. The transport of solute in the pore is dominated by diffusion, although convective transport is significant for organic nitrogen compounds. Electromigration contributes negligibly to the overall solute transport in the membrane. Urea, a small organic compound, has lower rejection than ionic compounds such as ammonium, nitrate, and nitrite, indicating the critical role of electrostatic interaction in rejection. This suggests that better treatment efficiency for organic nitrogen compounds can be obtained after ammonification of urea.

  18. Hand chemical burns.

    Science.gov (United States)

    Robinson, Elliot P; Chhabra, A Bobby

    2015-03-01

    There is a vast and ever-expanding variety of potentially harmful chemicals in the military, industrial, and domestic landscape. Chemical burns make up a small proportion of all skin burns, yet they can cause substantial morbidity and mortality. Additionally, the hand and upper extremity are the most frequently involved parts of the body in chemical burns, and therefore these injuries may lead to severe temporary or permanent loss of function. Despite this fact, discussion of the care of these injuries is sparse in the hand surgery literature. Although most chemical burns require only first response and wound care, some require the attention of a specialist for surgical debridement and, occasionally, skin coverage and reconstruction. Exposure to certain chemicals carries the risk of substantial systemic toxicity and even mortality. Understanding the difference between thermal and chemical burns, as well as special considerations for specific compounds, will improve patient treatment outcomes.

  19. Chemical Emergencies

    Science.gov (United States)

    When a hazardous chemical has been released, it may harm people's health. Chemical releases can be unintentional, as in the case of an ... the case of a terrorist attack with a chemical weapon. Some hazardous chemicals have been developed by ...

  20. Synthesizing Novel Anthraquinone Natural Product-Like Compounds to Investigate Protein-Ligand Interactions in Both an in Vitro and in Vivo Assay: An Integrated Research-Based Third-Year Chemical Biology Laboratory Course

    Science.gov (United States)

    McKenzie, Nancy; McNulty, James; McLeod, David; McFadden, Meghan; Balachandran, Naresh

    2012-01-01

    A new undergraduate program in chemical biology was launched in 2008 to provide a unique learning experience for those students interested in this interdisciplinary science. An innovative undergraduate chemical biology laboratory course at the third-year level was developed as a key component of the curriculum. The laboratory course introduces…

  1. The chemical and environmental property space of REACH chemicals.

    Science.gov (United States)

    Öberg, Tomas; Iqbal, M Sarfraz

    2012-05-01

    The European regulation on chemicals, REACH (Registration, Evaluation, Authorisation and Restriction of Chemicals), came into force on 1 June 2007. With pre-registration complete in 2008, data for these substances may provide an overview of the expected chemical space and its characteristics. In this paper, using various in silico computation tools, we evaluate 48782 neutral organic compounds from the list to identify hazardous and safe compounds. Two different classification schemes (modified Verhaar and ECOSAR) identified between 17% and 25% of the compounds as expressing only baseline toxicity (narcosis). A smaller portion could be identified as reactive (19%) or specifically acting (2.7%), while the majority were non-assigned (61%). Overall environmental persistence, bioaccumulation and long-range transport potential were evaluated using structure-activity relationships and a multimedia fugacity-based model. A surprisingly high proportion of compounds (20%), mainly aromatic and halogenated, had a very high estimated persistence (>195 d). The proportion of compounds with a very high estimated bioconcentration or bioaccumulation factor (>5000) was substantially less (6.9%). Finally, a list was compiled of those compounds within the applicability domain of the models used, meeting both persistence and bioaccumulation criteria, and with a long-range transport potential comparable to PCB. This list of 68 potential persistent organic pollutants contained many well-known compounds (all halogenated), but notably also five fluorinated compounds that were not included in the EINECS inventory. This study demonstrates the usability of in silico tools for identification of potentially environmentally hazardous chemicals.

  2. Heterogeneous photocatalytic reactions of sulfur aromatic compounds.

    Science.gov (United States)

    Samokhvalov, Alexander

    2011-11-18

    Sulfur aromatic compounds, such as mono-, di-, tri-, and tetraalkyl-substituted thiophene, benzothiophenes, dibenzothiophenes, are the molecular components of many fossils (petroleum, oil shale, tar sands, bitumen). Structural units of natural, cross-linked heteroaromatic polymers present in brown coals, turf, and soil are similar to those of sulfur aromatic compounds. Many sulfur aromatic compounds are found in the streams of petroleum refining and upgrading (naphthas, gas oils) and in the consumer products (gasoline, diesel, jet fuels, heating fuels). Besides fossils, the structural fragments of sulfur aromatic compounds are present in molecules of certain organic semiconductors, pesticides, small molecule drugs, and in certain biomolecules present in human body (pheomelanin pigments). Photocatalysis is the frontier area of physical chemistry that studies chemical reactions initiated by absorption of photons by photocatalysts, that is, upon electronic rather than thermal activation, under "green" ambient conditions. This review provides systematization and critical review of the fundamental chemical and physicochemical information on heterogeneous photocatalysis of sulfur aromatic compounds accumulated in the last 20-30 years. Specifically, the following topics are covered: physicochemical properties of sulfur aromatic compounds, major classes of heterogeneous photocatalysts, mechanisms and reactive intermediates of photocatalytic reactions of sulfur aromatic compounds, and the selectivity of these reactions. Quantum chemical calculations of properties and structures of sulfur aromatic compounds, their reactive intermediates, and the structure of adsorption complexes formed on the surface of the photocatalysts are also discussed.

  3. [Triterpene compounds from Cirsium setosum].

    Science.gov (United States)

    Li, Lingling; Sun, Zheng; Shang, Xiaoya; Li, Jinjie; Wang, Rong; Zhu, Jie

    2012-04-01

    To investigate chemical constituents contained in cytotoxic petroleum ether extractive fractions from ethanol extracts of Cirsium setosum. The constituents were separated and purified by a combination of various chromatographic methods including silica gel, Sephadex LH-20, and preparative HPLC. Structures of the isolates were elucidated by spectroscopic methods including 1D, 2D NMR and MS methods. The compound structures were also determined by reference to literature. Twelve compounds were separated from the petroleum ether fraction of ethanolic extract and elucidated as lupenyl acetate (1), lupeol (2), lupenone (3), beta-amyrin (4), psi-taraxasterol (5), psi-taraxasteryl acetate (6), taraxasteryl acetate (7), marsformoxide B (8), alpha-amyrenone (9), beta-amyrenone (10), taraxasterone (11) and psi-taraxasterone (12). Of them, compounds 3, 5, 7-12 were separated from this genus for the first time.

  4. Synthesis, Chemistry, and Applications of Heterocyclic Cage Compounds (V)

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    @@ The synthesis and chemistry of polycyclic of cage compounds have attracted considerable attention in recent years. The vast majority of the work reported in this area has dealt with carbocylic cage compounds. On the other hand, the synthesis and chemistry of heterocyclic cage compounds have received less attention. Recently, we envisioned that studies on the synthesis and chemistry of heterocyclic cage compounds can greatly expand the scopes and utilities of cage compounds.1 As part of a program that involves the synthesis, chemistry, and application of heterocyclic cage compounds, we report here the synthesis of new thia-oxa-cage compounds and the chemical nature of these thia-cages.

  5. Inhibitory Effects of Chemical Compounds Isolated from the Rhizome of Smilax glabra on Nitric Oxide and Tumor Necrosis Factor-α Production in Lipopolysaccharide-Induced RAW264.7 Cell

    Directory of Open Access Journals (Sweden)

    Chuan-li Lu

    2015-01-01

    Full Text Available The rhizome of Smilax glabra has been used for a long time as both food and folk medicine in many countries. The present study focused on the active constituents from the rhizome of S. glabra, which possess potential anti-inflammatory activities. As a result, nine known compounds were isolated from the rhizome of S. glabra with the bioassay-guiding, and were identified as syringaresinol (1, lasiodiplodin (2, de-O-methyllasiodiplodin (3, syringic acid (4, 1,4-bis(4-hydroxy-3,5-dimethoxyphenyl-2,3-bis(hydroxymethyl-1,4-butanediol (5, lyoniresinol (6, trans-resveratrol (7, trans-caffeic acid methyl ester (8, and dihydrokaempferol (9. Among these compounds, 2 and 3 were isolated for the first time from S. glabra. In addition, the potential anti-inflammatory activities of the isolated compounds were evaluated in vitro in lipopolysaccharide- (LPS- induced RAW264.7 cells. Results indicated that 4 and 7 showed significant inhibitory effects on NO production of RAW264.7 cells, and 1, 2, 3, and 5 showed moderate suppression effects on induced NO production. 1, 7, and 5 exhibited high inhibitory effects on TNF-α production, with the IC50 values less than 2.3, 4.4, and 16.6 μM, respectively. These findings strongly suggest that compounds 1, 2, 3, 4, 5, 7, and 9 were the potential anti-inflammatory active compositions of S. glabra.

  6. Organic electronic devices using phthalimide compounds

    Science.gov (United States)

    Hassan, Azad M.; Thompson, Mark E.

    2010-09-07

    Organic electronic devices comprising a phthalimide compound. The phthalimide compounds disclosed herein are electron transporters with large HOMO-LUMO gaps, high triplet energies, large reduction potentials, and/or thermal and chemical stability. As such, these phthalimide compounds are suitable for use in any of various organic electronic devices, such as OLEDs and solar cells. In an OLED, the phthalimide compounds may serve various functions, such as a host in the emissive layer, as a hole blocking material, or as an electron transport material. In a solar cell, the phthalimide compounds may serve various functions, such as an exciton blocking material. Various examples of phthalimide compounds which may be suitable for use in the present invention are disclosed.

  7. Controvérsias sobre a proteção patentária de segundo uso médico de compostos químicos conhecidos Controversies on the patent protection for second medical use of known chemical compounds

    Directory of Open Access Journals (Sweden)

    Maria Lucia Abranches da Silva

    2010-01-01

    Full Text Available The present work provides an overview of patent protection for second medical use of known chemical compounds, in Brazil and other countries, through the approach of the main controversies related to this theme. That issues encompass aspects related to the legality of the protection granted by the patent, the general requirements of patenteability, the ethic and social concepts and the politic and economic factors involved. This work also introduces the diverging views of the two Brazilian government agencies involved in the procedure for granting patent in the pharmaceutical area, INPI and ANVISA.

  8. Bioaccessibility testing of cobalt compounds.

    Science.gov (United States)

    Stopford, Woodhall; Turner, John; Cappellini, Danielle; Brock, Tom

    2003-08-01

    Testing of metal compounds for solubility in artificial fluids has been used for many years to assist determining human health risk from exposure to specific compounds of concern. In lieu of obtaining bioavailability data from samples of urine, blood, or other tissues, these studies measured solubility of compounds in various artificial fluids as a surrogate for bioavailability. In this context, the measurement of metal "bioaccessibility" can be used as an in vitro substitute for measuring metal bioavailability. Bioaccessibility can be defined as a value representing the availability of metal for absorption when dissolved in in vitro surrogates of body fluids or juices. The aim of this study was to measure and compare the bioaccessibility of selected cobalt compounds in artificial human tissue fluids and human serum. A second aim was to initiate studies to experimentally validate an in vitro methodology that would provide a conservative estimate of cobalt bioavailability in the assessment of dose from human exposure to various species of cobalt compounds. This study evaluated the bioaccessibility of cobalt(II) from 11 selected cobalt compounds and an alloy in 2 physical forms in 5 surrogate human tissue fluids and human serum. Four (4) separate extraction times were used up to 72 hours. The effect of variables such as pH, dissolution time, and mass-ion effect on cobalt bioaccessibility were assessed as well. We found that the species of cobalt compound as well as the physico-chemical properties of the surrogate fluids, especially pH, had a major impact on cobalt solubility. Cobalt salts such as cobalt(II) sulfate heptahydrate were highly soluble, whereas cobalt alloys used in medical implants and cobalt aluminate spinels used as pigments, showed minimal dissolution over the period of the assay.

  9. Group IB Organometallic Chemistry XXXIV: Thermal behavior and chemical reactivity of tetranuclear Me2N-substituted diarylpropenylcopper-copper anion (Vi2Cu4X2) and mixed diarylpropenyl/organocopper (Vi2Cu4R2) compounds

    NARCIS (Netherlands)

    Koten, G. van; Hoedt, R.W.M. ten; Noltes, J.G.

    1980-01-01

    Thermal decomposition of configurationally pure 1, 2-diarylpropenylcopper compounds Z-Vi{2}CU{4}Br{2} and Z-Vi{2}Cu{4}R{2} [Vi @? (2-Me{2}NC{6}H{4})C@?C(Me)-(C{6}H{4}Me-4), R @? 2-Me{2}NC{6}H{4} or 4-MeC{6}H{4}C@?C] predominantly results in the formation of ViH. In contrast, only dimers (ViVi) were

  10. Research in Physical Chemistry and Chemical Education: Part A--Water Mediated Chemistry of Oxidized Atmospheric Compounds Part B--The Development of Surveying Tools to Determine How Effective Laboratory Experiments Contribute to Student Conceptual Understanding

    Science.gov (United States)

    Maron, Marta Katarzyna

    2011-01-01

    This dissertation is a combination of two research areas, experimental physical chemistry, Chapters I to V, and chemical education, Chapters VI to VII. Chapters I to V describe research on the water-mediated chemistry of oxidized atmospheric molecules and the impact that water has on the spectra of these environmental systems. The role of water…

  11. A utilização do safrol, principal componente químico do óleo de sassafráz, na síntese de substâncias bioativas na cascata do ácido araquidônico: antiinflamatórios, analgésicos e anti-trombóticos The utilization of the safrole, principal chemical constituent of sassafras oil, in the synthesis of compounds actives in the arachidonic acid cascade: antiinflammatory, analgesic and antithrombotic

    Directory of Open Access Journals (Sweden)

    Eliezer J. Barreiro

    1999-09-01

    Full Text Available In this paper we describe the results of a research effort developed in Laboratório de Avaliação e Síntese de Substancias Bioativas (LASSBio, UFRJ in the utilization of Brazilian abundant natural product, safrole (1, the principal chemical constituent of Sassafras oil (Ocotea pretiosa, as an attractive synthon to access different chemical class of bioactive compounds, as prostaglandins analogues, non-steroidal antiinflammatory agents and antithrombotic compounds.

  12. High resolution NMR theory and chemical applications

    CERN Document Server

    Becker, Edwin D

    1969-01-01

    High Resolution NMR: Theory and Chemical Applications focuses on the applications of nuclear magnetic resonance (NMR), as well as chemical shifts, lattices, and couplings. The book first offers information on the theory of NMR, including nuclear spin and magnetic moment, spin lattice relaxation, line widths, saturation, quantum mechanical description of NMR, and ringing. The text then ponders on instrumentation and techniques and chemical shifts. Discussions focus on the origin of chemical shifts, reference compounds, empirical correlations of chemical shifts, modulation and phase detection,

  13. BASF Launches New Compounding Plant in China

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    @@ BASF, a leading international chemical company,kicked off construction of an engineering plastics compounding plant Pudong Area in Shanghai in midMay. The new facility is a world-scale plant with annual capacity of 45,000 tons. It is one of the most modern compounding plants in the world today, with "the highest environmental standards and the most efficient production capabilities available," according to a BASF official.

  14. Techniques for Analysis of Plant Phenolic Compounds

    OpenAIRE

    Roberts, Thomas H.; Meredith A. Wilkes; Ali Khoddami

    2013-01-01

    Phenolic compounds are well-known phytochemicals found in all plants. They consist of simple phenols, benzoic and cinnamic acid, coumarins, tannins, lignins, lignans and flavonoids. Substantial developments in research focused on the extraction, identification and quantification of phenolic compounds as medicinal and/or dietary molecules have occurred over the last 25 years. Organic solvent extraction is the main method used to extract phenolics. Chemical procedures are used to detect the pre...

  15. Health promoting compounds in vegetables and fruits:

    DEFF Research Database (Denmark)

    Brandt, K.; Christensen, L.P.; Hansen-Møller, J.

    2004-01-01

    Vegetables contain unknown compounds with important health promoting effect. The described project defined and tested a two-step screening procedure for identification of such compounds. Step 1 is initial screening according to three criteria: 1.1, chemically reactive functional groups; 1.2, toxi...... in bioassay; and 2.3, possibility to control content in food. Falcarinol from carrots fulfilled all 6 criteria and subsequently showed anticancer effect in rats....

  16. Group ib organometallic chemistry. XXXIV. Thermal behaviour and chemical reactivity of tetranuclear Me2N-substituted diarypropenylcopper-copper anion (Vi2Cu4X2) and mixed diarylpropenyl/organocopper (Vi2Cu4R2) compounds

    NARCIS (Netherlands)

    Hoedt, R.W.M. ten; Koten, G. van; Noltes, J.G.

    1980-01-01

    Thermal decomposition of configurationally pure 1,2-diarylpropenylcopper compounds Z-Vi2CU4Br2 and Z-Vi2Cu4R2 [Vi = (2-Me2NC6H4)C=C(Me)-(C6H4Me-4), R = 2-Me2NC6H4 or 4-MeC6H4CC] predominantly results in the formation of ViH. In contrast, only dimers (ViVi) were formed on thermolysis of (Z-ViCu2OTf)η

  17. 三黄洗剂联合复方炉甘石洗剂在化学性静脉炎合并接触性皮炎患者中的应用%Effect of Sanhuang Lotion Combined with Compound Calamine Lotion on Patients with Chemical Phlebitis and Contact Dermatitis

    Institute of Scientific and Technical Information of China (English)

    谭萍; 尤久红

    2015-01-01

    目的:探讨三黄洗剂联合复方炉甘石洗剂在化学性静脉炎合并3M透明敷贴致接触性皮炎患者中的应用效果。方法选取入我院就诊发生化学性静脉炎合并接触性皮炎患者72例,按随机数字表法分为观察组和对照组各36例。对照组给予喜疗妥涂抹,观察组给予三黄洗剂联合复方炉甘石洗剂涂抹。观察比较两组患者化学性静脉炎及接触性皮炎的治疗显效时间及效果。结果观察组化学性静脉炎及接触性皮炎的治疗显效时间短于对照组(P<0.05),治疗效果优于对照组(P<0.05)。结论三黄洗剂与复方炉甘石洗剂的联合应用不仅起到了清热燥湿、泻火攻毒,疏通津液分布的作用,同时也起到了收敛、止痒、抗菌消炎和保护皮肤的作用,故其在一定程度上能够有效治疗化学性静脉炎合并3M透明敷贴所致的接触性皮炎,值得临床借鉴使用。%Objective To investigate the effect of Sanhuang Lotion combined compound calamine lotion in patients with chemical phlebitis and contact dermatitis. Methods Seventy-two patients with chemical phlebitis and contact dermatitis were randomly divided into observation group, in which Sanhuang Lotion and compound calamine lotion were applied, and control group, in which Hirudoid cream was used. The effects between two groups were compared. Results Sanhuang Lotion and compound calamine lotion worked more quickly and there was good effect in observation group (P<0.05). Conclusion Sanhuang Lotion combined compound calamine lotion has a good effect on chemical phlebitis and contact dermatitis and is worthy of promotion.

  18. An introduction to the chemistry of complex compounds

    CERN Document Server

    Grinberg, Aleksander Abramovich; Trimble, R F

    1962-01-01

    An Introduction to the Chemistry of Complex Compounds discusses the fundamental concepts that are essential in understanding the underlying principles of complex compounds. The coverage of the book includes the compounds of the hexa, penta, and tetrammine type; compounds of the tri, dl, monoamine and hexacido types for the coordination number of 6; and complex compounds with a coordination number of 4. The text also covers the effects and chemical properties of complex compounds, such as the nature of the force of complex formation; the mutual effects of coordinated groups; and acid-base prope

  19. Rare earths: preparation of spectro chemically pure standards, study of their carbonates and synthesis of a new compound series - the peroxy carbonates; Terras-raras: obtencao de padroes espectroquimicos, estudo dos carbonatos e sintese dos peroxicarbonatos. Uma nova serie de compostos

    Energy Technology Data Exchange (ETDEWEB)

    Queiroz, Carlos Alberto da Silva

    1996-05-01

    In this work the following studies are concerned: I) preparation of lanthanum, cerium, praseodymium, neodymium and samarium oxides for use as spectro chemically pure standards; II) behavior of the rare earth (La, Ce, Pr, Nd, Sm) carbonates soluble in ammonium carbonate and mixture of ammonium carbonate/ammonium hydroxide, and III) synthesis and characterization of rare earth peroxy carbonates - a new series of compounds. Data for the synthesis and characterization of the rare earths peroxy carbonates described for the first time in this work are presented and discussed. With the aid of thermal analysis (TG-DTG) the thermal stability and the stoichiometric composition for new compounds were established and a mechanism of thermal decomposition was proposed. The peroxy carbonate was prepared by the addition of hydrogen peroxyde to the complexed soluble rare earths carbonates. These studies included also the determinations of active oxygen, the total rare earth oxide by gravimetry and complexometry and the C, H and N contents by microanalysis. The new compounds were also investigated by infrared spectroscopy. (author)

  20. Fabrication of polyaniline-coated halloysite nanotubes by in situ chemical polymerization as a solid-phase microextraction coating for the analysis of volatile organic compounds in aqueous solutions.

    Science.gov (United States)

    Abolghasemi, Mir Mahdi; Arsalani, Naser; Yousefi, Vahid; Arsalani, Mahmood; Piryaei, Marzieh

    2016-03-01

    We have synthesized an organic-inorganic polyaniline-halloysite nanotube composite by an in situ polymerization method. This nanocomposite is immobilized on a stainless-steel wire and can be used as a fiber coating for solid-phase microextraction. It was found that our new solid-phase microextraction fiber is an excellent adsorbent for the extraction of some volatile organic compounds in aqueous samples in combination with gas chromatography and mass spectrometry. The coating can be prepared easily, is mechanically stable, and exhibits relatively high thermal stability. It is capable of extracting phenolic compounds from water samples. Following thermal desorption, the phenols were quantified by gas chromatography with mass spectrometry. The effects of extraction temperature, extraction time, sample ionic strength, stirring rate, pH, desorption temperature and desorption time were studied. Under optimal conditions, the repeatability for one fiber (n = 5), expressed as the relative standard deviation, is between 6.2 and 9.1%. The detection limits range from 0.005 to 4 ng/mL. The method offers the advantage of being simple to use, with a shorter analysis time, lower cost of equipment and higher thermal stability of the fiber in comparison to conventional methods of analysis.

  1. Identification of Chemical Toxicity Using Ontology Information of Chemicals

    Directory of Open Access Journals (Sweden)

    Zhanpeng Jiang

    2015-01-01

    Full Text Available With the advance of the combinatorial chemistry, a large number of synthetic compounds have surged. However, we have limited knowledge about them. On the other hand, the speed of designing new drugs is very slow. One of the key causes is the unacceptable toxicities of chemicals. If one can correctly identify the toxicity of chemicals, the unsuitable chemicals can be discarded in early stage, thereby accelerating the study of new drugs and reducing the R&D costs. In this study, a new prediction method was built for identification of chemical toxicities, which was based on ontology information of chemicals. By comparing to a previous method, our method is quite effective. We hope that the proposed method may give new insights to study chemical toxicity and other attributes of chemicals.

  2. Prioritizing pesticide compounds for analytical methods development

    Science.gov (United States)

    Norman, Julia E.; Kuivila, Kathryn M.; Nowell, Lisa H.

    2012-01-01

    The U.S. Geological Survey (USGS) has a periodic need to re-evaluate pesticide compounds in terms of priorities for inclusion in monitoring and studies and, thus, must also assess the current analytical capabilities for pesticide detection. To meet this need, a strategy has been developed to prioritize pesticides and degradates for analytical methods development. Screening procedures were developed to separately prioritize pesticide compounds in water and sediment. The procedures evaluate pesticide compounds in existing USGS analytical methods for water and sediment and compounds for which recent agricultural-use information was available. Measured occurrence (detection frequency and concentrations) in water and sediment, predicted concentrations in water and predicted likelihood of occurrence in sediment, potential toxicity to aquatic life or humans, and priorities of other agencies or organizations, regulatory or otherwise, were considered. Several existing strategies for prioritizing chemicals for various purposes were reviewed, including those that identify and prioritize persistent, bioaccumulative, and toxic compounds, and those that determine candidates for future regulation of drinking-water contaminants. The systematic procedures developed and used in this study rely on concepts common to many previously established strategies. The evaluation of pesticide compounds resulted in the classification of compounds into three groups: Tier 1 for high priority compounds, Tier 2 for moderate priority compounds, and Tier 3 for low priority compounds. For water, a total of 247 pesticide compounds were classified as Tier 1 and, thus, are high priority for inclusion in analytical methods for monitoring and studies. Of these, about three-quarters are included in some USGS analytical method; however, many of these compounds are included on research methods that are expensive and for which there are few data on environmental samples. The remaining quarter of Tier 1

  3. A new caffeate compound from Nardostachys chinensis.

    Science.gov (United States)

    Chen, Ying-peng; Wang, Zhong-ping; Zheng, Hong-hong; Xu, Yan-tong; Zhu, Yani; Zhang, Peng; Wu, Hong-hua

    2016-01-01

    A new caffeate compound, (E)-erythro-syringylglyceryl caffeate (1), was isolated from the roots and rhizomes of Nardostachys chinensis Batal., together with nine known phenolic compounds, including (+)-licarin A (2), naringenin 4', 7-dimethyl ether (3), pinoresinol-4-O-β-D-glucoside (4), caraphenol A (5), Z-miyabenol C (6), protocatechuic acid (7), caffeic acid (8), gallic acid (9) and vanillic acid (10). Their chemical structures were elucidated on the basis of spectroscopic data and physicochemical properties. Furthermore, this is the first report of compounds 2, 5 and 6 from Nardostachys genus.

  4. Data Mining and Discovery of Chemical Knowledge

    Science.gov (United States)

    Wencong, Lu

    In this chapter, the Data mining methods adopted are briefly introduced. The main focuses are on the successful applications of data mining methods in chemistry and chemical engineering. The discoveries of chemical knowledge cover the formation of ternary Intermetallic compounds, structure activity relationships of drugs, and industrial optimization based on chemical data mining methods, especially by using statistical pattern recognition and support vector machine.

  5. Experimental Demonstrations in Teaching Chemical Reactions.

    Science.gov (United States)

    Hugerat, Muhamad; Basheer, Sobhi

    2001-01-01

    Presents demonstrations of chemical reactions by employing different features of various compounds that can be altered after a chemical change occurs. Experimental activities include para- and dia-magnetism in chemical reactions, aluminum reaction with base, reaction of acid with carbonates, use of electrochemical cells for demonstrating chemical…

  6. 一种新的化合物指纹及其在药物筛选中的应用%A New Fingerprint of Chemical Compounds and Its Application to Drugs Virtual Screening

    Institute of Scientific and Technical Information of China (English)

    盛振; 黄琦; 康宏; 刘琦; 曹志伟; 朱瑞新

    2011-01-01

    Similarity searching is one of the most widely used techniques for virtual screening in large-scale drug discovery programmes.As one of the principal components,molecular descriptors play a crucial role in similarity searching.However,there is not yet one individual set of descriptors describing compounds perfectly so far.Recently,some research groups carried out similarity searching by fusing different fingerprints types.As these descriptors are all based on the structure of compounds,their fusions are more likely to cause redundancy far from describing compounds more comprehensively.Here,the Gene Ontology(GO) fingerprint is presented as a novo type of descriptor on the basis of GO terms and used to describe compounds together with structure fingerprint under the philosophy principle of describing substance from both nature and extend.The application of GO fingerprint reduces the dimensions of microarray data and avoids its problems such as high dimensions,strong correlation and so on.It also shortens the distance between the descriptors and the biological activities of compounds.Comparing of the similarity searching results derived from the methods using the structure fingerprint or the GO fingerprint only,the integrated method using both types shows much better description ability in two aspects.First,it can give a higher score to the compounds similar to the query in both structure and bioactivity.Second,it can effectively get rid of the compounds special in one side.As a conclusion,we propose a novo way for fast,effective,high-throughput drug discovery.It is expected to improve the results of virtual screening and accelerate the process of drug discovery and reuse of old drugs.%相似性搜索技术在大规模药物筛选中有着广泛的应用,而作为其构成要素之一的化合物描述符,则在相似性搜索中起着至关重要的作用.但是迄今为止,尚未发现一种描述符能够全面的描述化合物.近来,融合不同结构描述

  7. Potent acetylcholinesterase inhibitory compounds from Myristica fragrans.

    Science.gov (United States)

    Cuong, To Dao; Hung, Tran Manh; Han, Hyoung Yun; Roh, Hang Sik; Seok, Ji-Hyeon; Lee, Jong Kwon; Jeong, Ja Young; Choi, Jae Sue; Kim, Jeong Ah; Min, Byung Sun

    2014-04-01

    The anti-cholinesterase activity was evaluated of the ethyl acetate fraction of the methanol extract of Myristica fragrans Houtt (Myristicaceae) seeds and of compounds isolated from it by various chromatographic techniques. The chemical structures of the compounds were determined from spectroscopic analyses (NMR data). Thirteen compounds (1-13) were isolated and identified. Compound 8 { [(7S)-8'-(4'-hydroxy-3'-methoxyphenyl)-7-hydroxypropyl]benzene-2,4-diol) showed the most effective activity with an IC50 value of 35.1 microM, followed by compounds 2 [(8R,8'S)-7'-(3',4'-methylenedioxyphenyl)-8,8'-dimethyl-7-(3,4-dihydroxyphenyl)-butane] and 11 (malabaricone C) with IC50 values of 42.1 and 44.0 pM, respectively. This is the first report of significant anticholinesterase properties of M. fragrans seeds. The findings demonstrate that M. fragrans could be used beneficially in the treatment of Alzheimer's disease.

  8. Addition of nucleophiles on cyanoacetylene N≡CCH=CH-X (X = NH2, OH, SH, …). Synthesis and Physico-chemical Properties of Potential Prebiotic Compounds or Interstellar Molecules.

    Science.gov (United States)

    Guillemin, Jean-Claude

    Among the molecules detected to date in the interstellar medium (ISM), cyanopolyynes constitute a rich and important subset. These robust compounds exhibit special properties with respect to their reactivity and kinetic stability, and some have been found in other astrochemical environments, such as comets or in lab simulations of planetary atmospheres.[1] These systems are supposed to be good starting materials for the formation of new, more complex, astrochemical species, or amino acids on primitive Earth. The formal addition of water, hydrogen sulfur or ammonia on cyanoacetylene (H-C≡C-C≡N) gives the corresponding heterosubstitued acrylonitriles. We have extensively investigated the study of such adducts. With water, the formed cyanovinylalcohol (NC-CH=CH-OH) is in a tautomeric equilibrium with the kinetically more stable cyanoacetaldehyde (NC-CH2 CH(=O)). Isolation of these compounds in pure form is challenging but the gas phase infrared spectrum has been recorded. Reaction of ammonia with cyanoacetylene gives aminoacrylonitrile (H2 N-CH=CH-CN), a stable enamine; microwave and infrared spectra were obtained.[2] Similarly the MW spectrum of 3-mercapto-2-propenenitrile (HS-CH=CH-CN) has been recorded.[3] Attempts to detect both species in the ISM have been performed. A combined experimental and theoretical study on the gas-phase basicity and acidity of a series of cyanovinyl derivatives is also presented.[4] We will demonstrate that many particular physicochemical properties are associated to these simple adducts of cyanoacetylene, compounds often proposed as prebiotic molecules or components of the ISM. 1] S. W. Fow, K. Dose, Molecular Evolution and the Origin of Life, Marcel Dekker, Stateplace- New York, metricconverterProductID1977. A1977. A. Coustenis, T. Encrenaz, B. BJzard, B. Bjoraker, G. Graner, G. Dang-Nhu, E. AriJ, Icarus 1993, 102, 240 - 269. [2] Benidar, A. ; Guillemin, J.-C. ; M—, O. ; Y‡-ez, M. J. Phys. Chem. A. 2005, 109, 4705-4712. E

  9. Chemical constituents of Asparagus

    Directory of Open Access Journals (Sweden)

    J S Negi

    2010-01-01

    Full Text Available Asparagus species (family Liliaceae are medicinal plants of temperate Himalayas. They possess a variety of biological properties, such as being antioxidants, immunostimulants, anti-inflammatory, antihepatotoxic, antibacterial, antioxytocic, and reproductive agents. The article briefly reviews the isolated chemical constituents and the biological activities of the plant species. The structural formula of isolated compounds and their distribution in the species studied are also given.

  10. 40 CFR 721.785 - Halogenated alkane aromatic compound (generic name).

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Halogenated alkane aromatic compound... Specific Chemical Substances § 721.785 Halogenated alkane aromatic compound (generic name). (a) Chemical... as a halogenated alkane aromatic compound (PMN P-94-1747) is subject to reporting under this...

  11. 40 CFR 721.5330 - Nickel salt of an organo compound containing nitrogen.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Nickel salt of an organo compound... Specific Chemical Substances § 721.5330 Nickel salt of an organo compound containing nitrogen. (a) Chemical... as nickel salt of an organo compound containing nitrogen (PMN P-92-686) is subject to reporting...

  12. 40 CFR 721.9620 - Aromatic sulfonic acid compound with amine.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Aromatic sulfonic acid compound with... Specific Chemical Substances § 721.9620 Aromatic sulfonic acid compound with amine. (a) Chemical substance... aromatic sulfonic acid compound with amine (PMN P-93-832) is subject to reporting under this section...

  13. Chemical substructure analysis in toxicology

    Energy Technology Data Exchange (ETDEWEB)

    Beauchamp, R.O. Jr. [Center for Information on Toxicology and Environment, Raleigh, NC (United States)

    1990-12-31

    A preliminary examination of chemical-substructure analysis (CSA) demonstrates the effective use of the Chemical Abstracts compound connectivity file in conjunction with the bibliographic file for relating chemical structures to biological activity. The importance of considering the role of metabolic intermediates under a variety of conditions is illustrated, suggesting structures that should be examined that may exhibit potential activity. This CSA technique, which utilizes existing large files accessible with online personal computers, is recommended for use as another tool in examining chemicals in drugs. 2 refs., 4 figs.

  14. Volatile Organic Compounds (VOCs)

    Science.gov (United States)

    ... Share Facebook Twitter Google+ Pinterest Contact Us Volatile Organic Compounds' Impact on Indoor Air Quality On this ... Exposure Standards or Guidelines Additional Resources Introduction Volatile organic compounds (VOCs) are emitted as gases from certain ...

  15. Reissert compound of bisbenzimidazole

    OpenAIRE

    1989-01-01

    A Reissert compound of bisbenzimidazole can be formed by first reacting benzimidazole with an aliphatic diacid chloride to form bisbenzimidazole and then reacting the bisbenzimidazole with an aliphatic acid chloride and cyanide to form the Reissert compound thereof.

  16. Chemical genetics suggests a critical role for lysyl oxidase in zebrafish notochord morphogenesis† †Electronic supplementary information (ESI) available: Figure showing the of effect of 5 and 6 on the notochord and experimental details for compounds 2–6. See DOI: 10.1039/b613673g Click here for additional data file.

    Science.gov (United States)

    Anderson, Carrie; Bartlett, Stephen J.; Gansner, John M.; Wilson, Duncan; He, Ling; Gitlin, Jonathan D.

    2007-01-01

    As a result of a chemical genetic screen for modulators of metalloprotease activity, we report that 2-mercaptopyridine-N-oxide induces a conspicuous undulating notochord defect in zebrafish embryos, a phenocopy of the leviathan mutant. The location of the chemically-induced wavy notochord correlated with the timing of application, thus defining a narrow chemical sensitivity window during segmentation stages. Microscopic observations revealed that notochord undulations appeared during the phase of notochord cell vacuolation and notochord elongation. Notochord cells become swollen as well as disorganized, while electron microscopy revealed disrupted organization of collagen fibrils in the surrounding sheath. We demonstrate by assay in zebrafish extracts that 2-mercaptopyridine-N-oxide inhibits lysyl oxidase. Thus, we provide insight into notochord morphogenesis and reveal novel compounds for lysyl oxidase inhibition. Taken together, these data underline the utility of small molecules for elucidating the dynamic mechanisms of early morphogenesis and provide a potential explanation for the recently established role of copper in zebrafish notochord formation. PMID:17216056

  17. Chemical use

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This is a summary of research and activities related to chemical use on Neal Smith National Wildlife Refuge between 1992 and 2009. The chemicals used on the Refuge...

  18. Chemical Reactors.

    Science.gov (United States)

    Kenney, C. N.

    1980-01-01

    Describes a course, including content, reading list, and presentation on chemical reactors at Cambridge University, England. A brief comparison of chemical engineering education between the United States and England is also given. (JN)

  19. Preliminary classification of characteristic organic gunshot residue compounds.

    Science.gov (United States)

    Goudsmits, Ellen; Sharples, George P; Birkett, Jason W

    2016-12-01

    For the first time, a classification system for organic gunshot residue (OGSR) compounds with respect to the confirmation of OGSR materials is presented. There are 136 compounds considered to be associated with OGSR that have been highlighted in the literature. Many of these compounds could be classified as being ubiquitous in the environment and thus their detection as characteristic components of OGSR could cause issues with the interpretation of chemical ballistic evidence. The proposed system aims to address this problem by classifying OGSR compounds based on their forensic relevance with respect to the confirmation of GSR materials. To increase the forensic relevance of such a system, the large number of OGSR compounds reported in the literature has been decreased to 20 OGSR compounds based on the organic chemical composition of over 200 propellant powders. Occupational and environmental materials also associated with OGSR compounds have been considered.

  20. Physico-chemical characterization and bioactive compounds of blackberry fruits (Rubus sp. grown in Brazil Caracterização físico-química e de compostos bioativos em amora-preta (Rubus sp. cultivada no Brasil

    Directory of Open Access Journals (Sweden)

    Neuza Mariko Aymoto Hassimotto

    2008-09-01

    Full Text Available Five blackberry cultivars (Rubus sp. were evaluated for antioxidant capacity, bioactive compounds and composition. Ascorbic acid levels, consisting of dehydro-ascorbic acid, ranged from 9.8 to 21.4 mg.100 g-1 fresh weight. Cyanidin (66 to 80% of total flavonoids, epicatechin, quercetin and traces of kaempferol were the main flavonoids found in all cultivars. The five cultivars presented high antioxidant capacity in the β-carotene/linoleic acid system, with inhibition similar to the synthetic antioxidant BHT, at a 50 µM concentration. Caingangue cultivar presented high vitamin C and total phenolics content, while Guarani had the highest cyanidin, total anthocyanin and total flavonoids levels and also the highest antioxidant capacity. These cultivars also presented good TSS/TA ratios. From the data, at a quantitative level, blackberry can be considered a good source of bioactive compounds, as well as potentially beneficial to human health.Cinco cultivares de amora-preta (Rubus sp. foram avaliadas quanto a sua capacidade antioxidante, perfil de compostos bioativos e composição físico-química. Os níveis de ácido ascórbico total, presentes na forma de ácido desidroascórbico, variaram entre 9,8 a 21,4 mg.100 g-1 (b.u.. Os principais flavonóides presentes nas cinco cultivares foram: a antocianina cianidina (66 a 80% do total de flavonóides; o flavan-3-ol epicatequina; e os flavonóis quercetina e traços de caenferol. As cinco cultivares apresentaram alta capacidade antioxidante quando avaliadas pelo sistema de co-oxidação β-caroteno/ácido linoléico, similar ao antioxidante sintético BHT, na concentração de 50 µM. A cultivar Guarani apresentou os maiores teores de flavonóides totais, antocianina total, cianidina e de capacidade antioxidante, enquanto que a cultivar Caigangue apresentou alto conteúdo de vitamina C e de fenólicos totais. Estas duas cultivares também apresentaram uma boa correlação TSS/TA. Assim, a amora

  1. Xeno-estrogenic compounds in precipitation

    NARCIS (Netherlands)

    Peters, R.J.B.; Beeltje, H.; Delft, R.J.

    2008-01-01

    The exposure to some chemicals can lead to hormone disrupting effects. Presently, much attention is focused on so-called xeno-estrogens, synthetic compounds that interact with hormone receptors causing a number of reactions that eventually lead to effects related to reproduction and development. The

  2. Atmospheric nitrogen compounds: Occurrence, composition and deposition

    DEFF Research Database (Denmark)

    Nielsen, T.; Pilegaard, K.; Egeløv, A.H.;

    1996-01-01

    Traffic in cities and on highways is an important contributor to NOy atmospheric pollution in open areas. In this situation both the concentration and composition of NOy compounds show a wide variation and are dependent on meteorological and atmospheric chemical conditions. The proportion of NOz...

  3. Chemical modification of L-glutamine to alpha-amino glutarimide on autoclaving facilitates Agrobacterium infection of host and non-host plants: A new use of a known compound

    Directory of Open Access Journals (Sweden)

    Das Pralay

    2011-05-01

    Full Text Available Abstract Background Accidental autoclaving of L-glutamine was found to facilitate the Agrobacterium infection of a non host plant like tea in an earlier study. In the present communication, we elucidate the structural changes in L-glutamine due to autoclaving and also confirm the role of heat transformed L-glutamine in Agrobacterium mediated genetic transformation of host/non host plants. Results When autoclaved at 121°C and 15 psi for 20 or 40 min, L-glutamine was structurally modified into 5-oxo proline and 3-amino glutarimide (α-amino glutarimide, respectively. Of the two autoclaved products, only α-amino glutarimide facilitated Agrobacterium infection of a number of resistant to susceptible plants. However, the compound did not have any vir gene inducing property. Conclusions We report a one pot autoclave process for the synthesis of 5-oxo proline and α-amino glutarimide from L-glutamine. Xenobiotic detoxifying property of α-amino glutarimide is also proposed.

  4. Environmental/chemical thesaurus

    Energy Technology Data Exchange (ETDEWEB)

    Shriner, C.R.; Dailey, N.S.; Jordan, A.C.; Miller, K.C.; Owens, E.T.; Rickert, L.W.

    1978-06-01

    The Environmental/Chemical Thesaurus approaches scientific language control problems from a multidisciplinary view. The Environmental/Biomedical Terminology Index (EBTI) was used as a base for the present thesaurus. The Environmental/Chemical Thesaurus, funded by the Environmental Protection Agency, used as its source of new terms those major terms found in 13 Environmental Protection Agency data bases. The scope of this thesaurus includes not only environmental and biomedical sciences, but also the physical sciences with emphasis placed on chemistry. Specific chemical compounds are not included; only classes of chemicals are given. To adhere to this level of classification, drugs and pesticides are identified by class rather than by specific chemical name. An attempt was also made to expand the areas of sociology and economics. Terminology dealing with law, demography, and geography was expanded. Proper names of languages and races were excluded. Geographic terms were expanded to include proper names for oceans, continents, major lakes, rivers, and islands. Political divisions were added to allow for proper names of countries and states. With such a broad scope, terminology for specific sciences does not provide for indexing to the lowest levels in plant, animal, or chemical classifications.

  5. Radiation synthesis of materials and compounds

    CERN Document Server

    Kharisov, Boris Ildusovich; Ortiz Méndez, Ubaldo

    2013-01-01

    Researchers and engineers working in nuclear laboratories, nuclear electric plants, and elsewhere in the radiochemical industries need a comprehensive handbook describing all possible radiation-chemistry interactions between irradiation and materials, the preparation of materials under distinct radiation types, the possibility of damage of materials under irradiation, and more. Radiation nanotechnology is still practically an undeveloped field, except for some achievements in the fabrication of metallic nanoparticles under ionizing flows. Radiation Synthesis of Materials and Compounds presents the state of the art of the synthesis of materials, composites, and chemical compounds, and describes methods based on the use of ionizing radiation. It is devoted to the preparation of various types of materials (including nanomaterials) and chemical compounds using ionizing radiation (alpha particles, beta particles, gamma rays, x-rays, and neutron, proton, and ion beams). The book presents contributions from leaders ...

  6. Research in physical chemistry and chemical education: Part A: Water Mediated Chemistry of Oxidized Atmospheric Compounds Part B: The Development of Surveying Tools to Determine How Effective Laboratory Experiments Contribute to Student Conceptual Understanding

    Science.gov (United States)

    Maron, Marta Katarzyna

    This dissertation is a combination of two research areas, experimental physical chemistry, Chapters I to V, and chemical education, Chapters VI to VII. Chapters I to V describe research on the water-mediated chemistry of oxidized atmospheric molecules and the impact that water has on the spectra of these environmental systems. The role of water in the Earth's atmosphere has been of considerable interest due to its ability to impact chemistry and climate. Oxidized atmospheric molecules in the presence of water have the ability to form hydrogen bonded water complexes. The spectroscopic investigation of nitric acid-water complexes, outlined in Chapter III, was undertaken to characterize intermolecular hydrogen bonds in a water-restricted environment at ambient temperatures. Additionally, this characterization of nitric acid-water complexes allowed for the comparison of calculated overtone OH-stretching vibrational band frequencies, intensities, and anharmonicities of intermolecular hydrogen-bonded water complexes with experimental observations. Oxidized organic molecules, such as aldehydes and ketones, in addition to forming hydrogen-bonded water complexes can undergo a hydration reaction of the carbonyl group and form germinal diols in the presence of water. This chemistry has been studied extensively in bulk aqueous media, however little is known about this process in the gas-phase at low water concentrations. The focus of the studies outlined in Chapters IV and V is motivated by the ability of pyruvic acid and formaldehyde to form germinal diols and water complexes in water-restricted environment. This water-mediated chemistry changes the physical and chemical properties of these organic molecules, therefore, impacting the partitioning between gas and particle phase, as well as the chemistry and photochemistry of oxidized organic molecules in the Earth's atmosphere. The results presented in this dissertation may help resolve the significant discrepancy between

  7. Carbonyl compounds generated from electronic cigarettes.

    Science.gov (United States)

    Bekki, Kanae; Uchiyama, Shigehisa; Ohta, Kazushi; Inaba, Yohei; Nakagome, Hideki; Kunugita, Naoki

    2014-10-28

    Electronic cigarettes (e-cigarettes) are advertised as being safer than tobacco cigarettes products as the chemical compounds inhaled from e-cigarettes are believed to be fewer and less toxic than those from tobacco cigarettes. Therefore, continuous careful monitoring and risk management of e-cigarettes should be implemented, with the aim of protecting and promoting public health worldwide. Moreover, basic scientific data are required for the regulation of e-cigarette. To date, there have been reports of many hazardous chemical compounds generated from e-cigarettes, particularly carbonyl compounds such as formaldehyde, acetaldehyde, acrolein, and glyoxal, which are often found in e-cigarette aerosols. These carbonyl compounds are incidentally generated by the oxidation of e-liquid (liquid in e-cigarette; glycerol and glycols) when the liquid comes in contact with the heated nichrome wire. The compositions and concentrations of these compounds vary depending on the type of e-liquid and the battery voltage. In some cases, extremely high concentrations of these carbonyl compounds are generated, and may contribute to various health effects. Suppliers, risk management organizations, and users of e-cigarettes should be aware of this phenomenon.

  8. Carbonyl Compounds Generated from Electronic Cigarettes

    Directory of Open Access Journals (Sweden)

    Kanae Bekki

    2014-10-01

    Full Text Available Electronic cigarettes (e-cigarettes are advertised as being safer than tobacco cigarettes products as the chemical compounds inhaled from e-cigarettes are believed to be fewer and less toxic than those from tobacco cigarettes. Therefore, continuous careful monitoring and risk management of e-cigarettes should be implemented, with the aim of protecting and promoting public health worldwide. Moreover, basic scientific data are required for the regulation of e-cigarette. To date, there have been reports of many hazardous chemical compounds generated from e-cigarettes, particularly carbonyl compounds such as formaldehyde, acetaldehyde, acrolein, and glyoxal, which are often found in e-cigarette aerosols. These carbonyl compounds are incidentally generated by the oxidation of e-liquid (liquid in e-cigarette; glycerol and glycols when the liquid comes in contact with the heated nichrome wire. The compositions and concentrations of these compounds vary depending on the type of e-liquid and the battery voltage. In some cases, extremely high concentrations of these carbonyl compounds are generated, and may contribute to various health effects. Suppliers, risk management organizations, and users of e-cigarettes should be aware of this phenomenon.

  9. Core bioactive components promoting blood circulation in the traditional Chinese medicine compound xueshuantong capsule (CXC) based on the relevance analysis between chemical HPLC fingerprint and in vivo biological effects.

    Science.gov (United States)

    Liu, Hong; Liang, Jie-ping; Li, Pei-bo; Peng, Wei; Peng, Yao-yao; Zhang, Gao-min; Xie, Cheng-shi; Long, Chao-feng; Su, Wei-wei

    2014-01-01

    Compound xueshuantong capsule (CXC) is an oral traditional Chinese herbal formula (CHF) comprised of Panax notoginseng (PN), Radix astragali (RA), Salvia miltiorrhizae (SM), and Radix scrophulariaceae (RS). The present investigation was designed to explore the core bioactive components promoting blood circulation in CXC using high-performance liquid chromatography (HPLC) and animal studies. CXC samples were prepared with different proportions of the 4 herbs according to a four-factor, nine-level uniform design. CXC samples were assessed with HPLC, which identified 21 components. For the animal experiments, rats were soaked in ice water during the time interval between two adrenaline hydrochloride injections to reduce blood circulation. We assessed whole-blood viscosity (WBV), erythrocyte aggregation and red corpuscle electrophoresis indices (EAI and RCEI, respectively), plasma viscosity (PV), maximum platelet aggregation rate (MPAR), activated partial thromboplastin time (APTT), and prothrombin time (PT). Based on the hypothesis that CXC sample effects varied with differences in components, we performed grey relational analysis (GRA), principal component analysis (PCA), ridge regression (RR), and radial basis function (RBF) to evaluate the contribution of each identified component. Our results indicate that panaxytriol, ginsenoside Rb1, angoroside C, protocatechualdehyde, ginsenoside Rd, and calycosin-7-O-β-D-glucoside are the core bioactive components, and that they might play different roles in the alleviation of circulation dysfunction. Panaxytriol and ginsenoside Rb1 had close relevance to red blood cell (RBC) aggregation, angoroside C was related to platelet aggregation, protocatechualdehyde was involved in intrinsic clotting activity, ginsenoside Rd affected RBC deformability and plasma proteins, and calycosin-7-O-β-D-glucoside influenced extrinsic clotting activity. This study indicates that angoroside C, calycosin-7-O-β-D-glucoside, panaxytriol, and

  10. A New Compound Along With Seven Known Compounds from an Endophytic Fungus Aspergillus sp. HS-05

    Directory of Open Access Journals (Sweden)

    Gang Chen

    2013-08-01

    Full Text Available Investigation of EtOAc extract from the fermentation broth of the endophytic fungus Asperilligus sp. HS-05 led to the isolation of a new compound (1 of spiro moiety named aspergispiroketal and seven known compounds (2-8. Their structures were elucidated mainly by NMR and HR-TOF-MS, as well as on comparison with the reported data. The absolute configuration of 1 was defined by comparison of quantum chemical TDDFT calculated and experimental ECD spectra.

  11. The Effects of Plant Secondary Compounds on Herbivorous Insects

    Directory of Open Access Journals (Sweden)

    Oğuzhan Yanar

    2017-02-01

    Full Text Available Plants have developed mechanical and chemical defense strategies that are effective against herbivores. Plants contain chemicals that are known as secondary metabolites (allelochemical and these chemicals do not directly involve in organisms’ reproduction and growth, on the other hand, they affect survival, growth and behavior of species. These compounds usually take ecological tasks and plants use these compounds against diseases, parasites, and predators for interspecies competition. It is known through the observations on feeding of herbivorous insects that these compounds act as deterrent chemicals or they are toxic against them. Feeding is one of the most fundamental and the most important behaviors for herbivorous insects. Even though host plant preference of herbivores is partially depend on nutrients, this behavior greatly depends on secondary chemistry of plants. Effects of secondary compounds on herbivorous insects can be positive or negative.

  12. Linking algal growth inhibition to chemical activity

    DEFF Research Database (Denmark)

    Schmidt, Stine N.; Mayer, Philipp

    to chemical activity, as opposed to e.g. the total concentration. Baseline toxicity (narcosis) for neutral hydrophobic organic compounds has been shown to initiate in the narrow chemical activity range of 0.01 to 0.1. This presentation focuses on linking algal growth inhibition to chemical activity....... High-quality toxicity data are carefully selected from peer-reviewed scientific literature and QSAR databases. This presentation shows how the chemical activity concept can be used to compare and combine toxicity data across compounds and species in order to characterize toxicity – and further how...

  13. Chemically enhanced in situ recovery

    Energy Technology Data Exchange (ETDEWEB)

    Sale, T. [CH2M Hill, Denver, CO (United States); Pitts, M.; Wyatt, K. [Surtek, Inc., Golden, CO (United States)] [and others

    1996-08-01

    Chemically enhanced recovery is a promising alternative to current technologies for management of subsurface releases of organic liquids. Through the inclusion of surfactants, solvents, polymers, and/or alkaline agents to a waterflood, the transport of targeted organic compounds can be increased and rates of recovery enhanced. By far, the vast majority of work done in the field of chemically enhanced recovery has been at a laboratory scale. The following text focuses on chemically enhanced recovery from a field application perspective with emphasis given to chlorinated solvents in a low permeability setting. While chlorinated solvents are emphasized, issues discussed are also relevant to organic liquids less dense than water such as petroleum products. Topics reviewed include: (1) Description of technology; (2) General technology considerations; (3) Low permeability media considerations; (4) Cost and reliability considerations; (5) Commercial availability; and (6) Case histories. Through this paper an appreciation is developed of both the potential and limitations of chemically enhanced recovery. Excluded from the scope of this paper is the in situ destruction of organic compounds through processes such as chemical or biological oxidation, chemically enhanced recovery of inorganic compounds, and ex situ soil treatment processes. 11 refs., 2 figs., 1 tab.

  14. Análise comparativa dos efeitos alelopáticos das substâncias químicas titonina e titonina acetilada Comparative analysis of the allelopathic effects of the chemical compounds tithonine and acetylated tithonine

    Directory of Open Access Journals (Sweden)

    A.P.S. Souza Filho

    2006-06-01

    Full Text Available Este trabalho teve por objetivo estabelecer as variações na atividade alelopática da substância química titonina, em função da acetilação de sua molécula. Bioensaios de germinação (25 ºC de temperatura constante e fotoperíodo de 12 horas e de desenvolvimento da radícula e do hipocótilo (25 ºC de temperatura constante e fotoperíodo de 24 horas foram desenvolvidos. Como planta receptora, utilizou-se a planta daninha Mimosa pudica (malícia. Análise de espectros RMN ¹H e 13C e técnicas de RMN bidimensionais foram realizadas na molécula acetilada. O processo de acetilação produziu a molécula 3'-acetil-7,4'-dimetoxiflavona, que diferiu da molécula original, identificada como 3'-hidroxi-7,4'-dimetoxiflavona. A estrutura da titonina-Ac foi confirmada pelos espectros de RMN ¹H, 13C, DEPT, COSY e HETCOR. A titonina foi acetilada com anidrido acético em piridina. A análise comparativa da atividade alelopática das duas substâncias revelou que titonina-Ac apresentou maior potencial para inibir tanto a germinação das sementes como o desenvolvimento da radícula e do hipocótilo da planta daninha malícia. A intensidade dos efeitos alelopáticos das duas substâncias esteve positivamente associada à concentração. O conjunto das informações obtidas permite sugerir a possibilidade de se aumentar a atividade alelopática de uma substância química sem comprometer suas peculiaridades biológicas desejáveis à natureza e aos interesses da sociedade.The objective of this paper was to establish the variations in the allelopathic activity of the chemical substance tithonine, in function of the acetylation of its molecule. Germination bioassays, under 25 ºC of constant temperature and 12-hour photoperiod, and radicle and hypocotyl development bioassays under 25ºC of constant temperature and 24-hour photoperiod were developed. The receiving plant used was the weed Mimosa pudica. Spectral analysis RMN ¹H and 13C and

  15. 不同络合剂对化学镀法制备镍包铜复合粉末的影响%Effect of different complexing agents on nickel-coated copper compound powder prepared with chemical plating

    Institute of Scientific and Technical Information of China (English)

    王玉棉; 孙建国; 赵忠兴; 徐瑞

    2013-01-01

    利用化学镀的方法制备镍包铜复合粉末,考察柠檬酸钠、醋酸钠和乳酸3种络合剂对Ni/Cu包覆粉体的转化率、包覆效果及分散性的影响.分别采用扫描电子显微镜、EDS能谱仪、X射线衍射仪对镍包铜粉末的微观形貌和物相组成进行表征.结果表明:采用柠檬酸钠作为络合剂能使镍更好地包覆于铜粉表面,镍金属原子分数大于90%,并且具有良好的分散性.%Using the chemical plating method,the nickel-coated copper composite powder was prepared,and the effect of three complexing agents of sodium citrate,sodium acetate,and lactic acid on the conversion,coating and dispersion of Ni/Cu cladding powder was examined.The microstructure and compositions of nickel-coated copper powder were characterized by means of scanning electron microscope,EDS energy spectrometer and X ray diffractometer respectively.The result showed that,using sodium citrate as complexing agent,the best nickel-coated copper powder could be prepared,and the atomic percentage content of nickel could reach more than 90%,and had good dispersity.

  16. Phytoestrogens: Plant-derived Estrogenic Compounds

    Directory of Open Access Journals (Sweden)

    Nevzat Konar

    2011-12-01

    Full Text Available Estrogen is a hormone, which is produced in ovary and testis; however, it has many biological effects besides the reproductive system. Phytoestrogens are the compounds, which have estrogen-like structure and activities, taking place in structure of various edible plants at different levels and in different compositions. These compounds attracted notice after the first quarter of 20th century upon they had been associated with infertility seen in some of animals fed with alfalfa, and these compounds have been identified in human-derived biological samples and its effects on health have been taken under study in the recent 30 years. These materials have especially antioxidant role in plants while they have activities in animals and humans as estrogen agonist and antagonists. Based on their chemical structure, they may be gathered under especially isoflavon and lignan groups while some of members of coumestan and stilbene groups are also identified as phytoestrogenic compound.

  17. Electrode reactions and electroanalysis of organomercury compounds

    Energy Technology Data Exchange (ETDEWEB)

    Kurmaz, Vladimir A [Institute of Problems of Chemical Physics, Russian Academy of Sciences, Chernogolovka, Moscow Region (Russian Federation); Gul' tyai, Vadim P [N.D.Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Moscow (Russian Federation)

    2010-06-09

    Characteristic features of mechanisms and kinetics of electrode reactions of organomercury compounds (symmetrical, non-symmetrical) and organomercury salts on a mercury electrode are analyzed. Attention is focused on the effect of coordination, adsorption and the nature and properties of intermediates on these processes as well as on the formation of organomercury derivatives in the adsorption of organic and hetero-organic compounds on a mercury electrode. The kinetics of heterogeneous chemical equilibrium {sup o}rganic calomel{sup -}symmetrical organomercury compound in the adsorption layer and the relative stability of intermediates in the one-electron reduction of organomercury salts are discussed as well as the electrolytic hydrogen evolution catalyzed by organomercury intermediates. The problems of combined and separate electrochemical quantitation of organic and inorganic mercury compounds in natural objects are considered.

  18. Techniques for Analysis of Plant Phenolic Compounds

    Directory of Open Access Journals (Sweden)

    Thomas H. Roberts

    2013-02-01

    Full Text Available Phenolic compounds are well-known phytochemicals found in all plants. They consist of simple phenols, benzoic and cinnamic acid, coumarins, tannins, lignins, lignans and flavonoids. Substantial developments in research focused on the extraction, identification and quantification of phenolic compounds as medicinal and/or dietary molecules have occurred over the last 25 years. Organic solvent extraction is the main method used to extract phenolics. Chemical procedures are used to detect the presence of total phenolics, while spectrophotometric and chromatographic techniques are utilized to identify and quantify individual phenolic compounds. This review addresses the application of different methodologies utilized in the analysis of phenolic compounds in plant-based products, including recent technical developments in the quantification of phenolics.

  19. Chemical Stimulation of Engineered Geothermal Systems

    Energy Technology Data Exchange (ETDEWEB)

    Rose, Peter, E.

    2008-08-08

    The objective of this project is to design, develop and demonstrate methods for the chemical stimulation of candidate EGS reservoirs as well as the chemical treatment of mineral-scaled wellbores. First, a set of candidate chemical compounds capable of dissolving calcite was identified. A series of tests was then performed on each candidate in order to screen it for thermal stability and reactivity towards calcite. A detailed analysis was then performed on each compound that emerged from the screening tests in order to characterize its decay kinetics and reaction kinetics as functions of temperature and chemical composition. From among the compounds emerging from the laboratory studies, one compounds was chosen for a field experiment in order to verify the laboratory predictions.

  20. Enhanced formulations for neutralization of chemical, biological and industrial toxants

    Science.gov (United States)

    Tucker, Mark D [Albuqueque, NM

    2008-06-24

    An enhanced formulation and method of making that neutralizes the adverse health effects of both chemical and biological compounds, especially chemical warfare (CW) and biological warfare (BW) agents, and toxic industrial chemicals. The enhanced formulation according to the present invention is non-toxic and non-corrosive and can be delivered by a variety of means and in different phases. The formulation provides solubilizing compounds that serve to effectively render the chemical and biological compounds, particularly CW and BW compounds, susceptible to attack, and at least one reactive compound that serves to attack (and detoxify or kill) the compound. The formulation includes at least one solubilizing agent, a reactive compound, a bleaching activator and water.

  1. Governing processes for reactive nitrogen compounds in the European atmosphere

    DEFF Research Database (Denmark)

    Hertel, Ole; Skjøth, Carsten Ambelas; Reis, S.;

    2012-01-01

    Reactive nitrogen (N-r) compounds have different fates in the atmosphere due to differences in the governing processes of physical transport, deposition and chemical transformation. N-r compounds addressed here include reduced nitrogen (NHx: ammonia (NH3) and its reaction product ammonium (NH4+))...

  2. PHARMACOLOGICAL AND MEDICINAL CHEMISTRY ASPECTS OF CANNABIS COMPOUNDS

    Directory of Open Access Journals (Sweden)

    T. Cotelea

    2011-12-01

    Full Text Available The current communication includes a general overview of the scientific interest and medicianl chemistry aspects of Cannabis compounds. It relates to metabolism, pharmacological action and phisico-chemical analysis of these compounds, as well as of some isomers differing in spatial arrangement of functional groups.

  3. Exploring Marine Environments To Unravel Tolerance Mechanisms To Relevant Compounds

    DEFF Research Database (Denmark)

    Machado, Henrique; Cavaleiro, Mafalda; Nørholm, Morten;

    2015-01-01

    Production of biofuels and chemicals using microorganisms has been a research driver in the last decades. The approach started with the engineering of metabolic pathways for production of compounds of interest, but it was soon realized that tolerance to the compounds being produced was one of the...

  4. Chemical sensors

    Science.gov (United States)

    Lowell, J.R. Jr.; Edlund, D.J.; Friesen, D.T.; Rayfield, G.W.

    1991-07-02

    Sensors responsive to small changes in the concentration of chemical species are disclosed. The sensors comprise a mechanochemically responsive polymeric film capable of expansion or contraction in response to a change in its chemical environment. They are operatively coupled to a transducer capable of directly converting the expansion or contraction to a measurable electrical response. 9 figures.

  5. Atributos químicos do solo e lixiviação de compostos fenólicos após adição de resíduo sólido alcalino Chemical attributes of soil and leaching of phenolic compounds after addition of alkaline solid residue

    Directory of Open Access Journals (Sweden)

    Sabrina B. Branco

    2013-05-01

    Full Text Available A utilização de resíduos alcalinos da indústria de papel e celulose (DREGS na agricultura como corretivo de acidez do solo, vem sendo amplamente empregada como alternativa de descarte no solo de forma a reduzir o impacto ambiental. Objetivou-se, com este trabalho, determinar a influência da aplicação do dregs, rejeito da indústria de papel e celulose, nos atributos químicos do solo e na lixiviação de compostos fenólicos. As unidades experimentais foram constituídas por colunas de lixiviação preenchidas com solo incorporado com dregs nas doses de 0,0; 2,5; 5,0 e 10,0 g kg-1. Foram realizadas análises químicas nos solos estudados, um Camibissolo Húmico e um Neossolo Quartzarênico, testes de solubilização dos compostos fenólicos e ensaios de lixiviação visando determinar os teores totais de compostos fenólicos presentes nos lixiviados. O uso do dregs modificou os atributos químicos do Cambissolo Húmico e do Neossolo Quartzarênico. Os resultados obtidos nas análises dos lixiviados demonstraram que a aplicação do dregs levou ao incremento de compostos acima do máximo permitido pela legislação vigente, 0,01 mg L-1(ANBR, 2004a e de 0,5 mg L-1 (CONAMA, 2008.The use of alkaline residues from pulp and paper industry ('dregs' in agriculture as a corrective of soil acidity is being widely used as an alternative of ground disposal in order to reduce the environmental impact. The objective of this study was to determine the influence of application of the 'dregs', waste from pulp and paper industry, in soil chemical properties and leaching of phenolic compounds. The experimental units consisted of leaching columns filled with soil incorporated with 'dregs' at doses of 0, 2.5, 5.0 and 10.0 g kg-1. Chemical analysis were performed in these soils, a Humic Camibissolo and a Typic Quartzipsamment soils, tests of solubilization of phenolic compounds and leaching tests were also carried out to determine the total content of phenolic

  6. Chemical and Pharmacological Researches on Hyoscyamus niger

    Institute of Scientific and Technical Information of China (English)

    LI Jun; SHI Ji; YU Xin-wen; SUN Jing-kuan; MEN Qi-ming; KANG Ting-guo

    2011-01-01

    The reports on chemical constituents of Hyoscyamus niger were summarized. The compounds include alkaloids, saponins, lignans, coumarinolignans, flavonoids, and some other nonalkaloidal compounds. TLC, HPLC, and GC were used for the qualitative and quantitative analyses of some chemical constituents in H. niger. Modern pharmacological experiments showed that H. niger had the analgesic, anti-inflammatory, antipyretic, anticonvulsant, spasmolytic, antidiarrhoeal, antisecretory, bronchodilatory, urinary bladder relaxant, hypotensive, cardiosuppressant, vasodilator, antitumor, and feeding deterrent properties. In addition, the toxicities of this medicinal plant were also described.

  7. Biodegradable compounds: Rheological, mechanical and thermal properties

    Science.gov (United States)

    Nobile, Maria Rossella; Lucia, G.; Santella, M.; Malinconico, M.; Cerruti, P.; Pantani, R.

    2015-12-01

    Recently great attention from industry has been focused on biodegradable polyesters derived from renewable resources. In particular, PLA has attracted great interest due to its high strength and high modulus and a good biocompatibility, however its brittleness and low heat distortion temperature (HDT) restrict its wide application. On the other hand, Poly(butylene succinate) (PBS) is a biodegradable polymer with a low tensile modulus but characterized by a high flexibility, excellent impact strength, good thermal and chemical resistance. In this work the two aliphatic biodegradable polyesters PBS and PLA were selected with the aim to obtain a biodegradable material for the industry of plastic cups and plates. PBS was also blended with a thermoplastic starch. Talc was also added to the compounds because of its low cost and its effectiveness in increasing the modulus and the HDT of polymers. The compounds were obtained by melt compounding in a single screw extruder and the rheological, mechanical and thermal properties were investigated. The properties of the two compounds were compared and it was found that the values of the tensile modulus and elongation at break measured for the PBS/PLA/Talc compound make it interesting for the production of disposable plates and cups. In terms of thermal resistance the compounds have HDTs high enough to contain hot food or beverages. The PLA/PBS/Talc compound can be, then, considered as biodegradable substitute for polystyrene for the production of disposable plates and cups for hot food and beverages.

  8. Metabolomics in chemical ecology.

    Science.gov (United States)

    Kuhlisch, Constanze; Pohnert, Georg

    2015-07-01

    Chemical ecology elucidates the nature and role of natural products as mediators of organismal interactions. The emerging techniques that can be summarized under the concept of metabolomics provide new opportunities to study such environmentally relevant signaling molecules. Especially comparative tools in metabolomics enable the identification of compounds that are regulated during interaction situations and that might play a role as e.g. pheromones, allelochemicals or in induced and activated defenses. This approach helps overcoming limitations of traditional bioassay-guided structure elucidation approaches. But the power of metabolomics is not limited to the comparison of metabolic profiles of interacting partners. Especially the link to other -omics techniques helps to unravel not only the compounds in question but the entire biosynthetic and genetic re-wiring, required for an ecological response. This review comprehensively highlights successful applications of metabolomics in chemical ecology and discusses existing limitations of these novel techniques. It focuses on recent developments in comparative metabolomics and discusses the use of metabolomics in the systems biology of organismal interactions. It also outlines the potential of large metabolomics initiatives for model organisms in the field of chemical ecology.

  9. Health promoting and sensory properties of phenolic compounds in food

    OpenAIRE

    Lívia de Lacerda de Oliveira; Mariana Veras de Carvalho; Lauro Melo

    2014-01-01

    Phenolic compounds have been extensively studied in recent years. The presence of these compounds in various foods has been associated with sensory and health promoting properties. These products from the secondary metabolism of plants act as defense mechanisms against environmental stress and attack by other organisms. They are divided into different classes according to their chemical structures. The objective of this study was to describe the different classes of phenolic compounds, the ma...

  10. Structural studies of type N superconductive compounds: R{sub 2-x}Ce{sub x}CuO{sub 4{+-}{delta}} (R = Gd, Eu, Sm, Nd, Pr); influences of chemical treatments on physical properties; Etudes structurales des composes supraconducteurs de type N: R{sub 2-x}Ce{sub x}CuO{sub 4{+-}{delta}} (R = Gd, Eu, Sm, Nd, Pr); influences des traitements chimiques sur les proprietes physiques

    Energy Technology Data Exchange (ETDEWEB)

    Vigoureux, P.

    1995-06-01

    Different chemical treatments of R{sub 2-x}Ce{sub x}CuO{sub 4{+-}{delta}} compounds monocrystals (gadolinium, europium, samarium, neodymium and praseodymium cuprates) modify their physical properties especially their superconductive properties. The presented chemical treatments are: the substitution of the trivalent rare earth element R by an other trivalent lanthanide, its substitution by tetravalent cerium, and heat treatment under low oxygen pressure. After these chemical treatments, structural modifications are observed by neutrons and X-rays diffraction, and allow to precise their actions: size effect of the rare earth element on the deformation of the CuO{sub 2} planes, links between deformation and superconductivity and magnetic properties. (A.B.). 394 refs/.

  11. Chemical constituents from Schisandra sphenanthera

    Institute of Scientific and Technical Information of China (English)

    Rong Tao Li; Zhi Ying Weng; Jian Xin Pu; Han Dong Sun

    2008-01-01

    The chemical constituents of the stems of Schisandra sphenanthera are described for the first time. This investigation has resulted in the isolation of a new phenolic glycoside (1), along with seven known compounds. The structure of 1 was assigned by using spectroscopic techniques, including 2D NMR spectra.

  12. Chemical constituents of Tephrosia purpurea.

    Science.gov (United States)

    Khalafalah, Ali K; Yousef, Afifi H; Esmail, Abeer M; Abdelrazik, Mohamed H; Hegazy, Mohamed E F; Mohamed, Abou-El-Hamd H

    2010-03-01

    In continuation of our chemical investigation on some medicinal plants of the genus Tephrosia, reinvestigation of the methylenechloride/methanol (1:1) extract of the aerial parts of Tephrosia purpurea yielded an aromatic ester 1, a sesquiterpene 2 and prenylated flavonoid 3. The structures of the compounds were established by comprehensive NMR studies, including DEPT, COSY, NOE, HMQC, HMBC, EIMS and CIMS.

  13. Chemical constituents of Tephrosia purpurea

    OpenAIRE

    Khalafalah, Ali K.; Yousef, Afifi H.; Abeer M Esmail; Abdelrazik, Mohamed H.; Hegazy, Mohamed E. F.; Abou-El-Hamd H Mohamed

    2010-01-01

    In continuation of our chemical investigation on some medicinal plants of the genus Tephrosia, reinvestigation of the methylenechloride/methanol (1:1) extract of the aerial parts of Tephrosia purpurea yielded an aromatic ester 1, a sesquiterpene 2 and prenylated flavonoid 3. The structures of the compounds were established by comprehensive NMR studies, including DEPT, COSY, NOE, HMQC, HMBC, EIMS and CIMS.

  14. Determination of phenolic compounds

    Energy Technology Data Exchange (ETDEWEB)

    Chao, G.K.J.; Suatoni, J.C.

    1982-01-01

    Details are given of a procedure for separation and identification of phenolic compounds in aqueous solution by high-performance liquid chromatography. It can also be applied to non-aqueous samples after preliminary isolation of a polar fraction containing the phenolic compounds.

  15. Chlorinated organic compounds in urban river sediments

    Energy Technology Data Exchange (ETDEWEB)

    Soma, Y.; Shiraishi, H.; Inaba, K. [National Inst. of Environmental Studies, Tsukuba, Ibaraki (Japan)

    1995-12-31

    Among anthropogenic chemicals, many chlorinated organic compounds have been used as insecticides and detected frequently as contaminants in urban river sediments so far. However, the number and total amount of chemicals produced commercially and used are increasing year by year, though each amount of chemicals is not so high. New types of contaminants in the environment may be detected by the use of newly developed chemicals. Chlorinated organic compounds in the urban river sediments around Tokyo and Kyoto, large cities in Japan, were surveyed and recent trends of contaminants were studied. Contaminants of the river sediments in industrial areas had a variety, but PCB (polychlorinated biphenyls) was detected in common in industrial areas. Concentration of PCB related well to the number of factories on both sides of rivers, although the use of PCB was stopped 20 years ago. In domestic areas, Triclosan (5-chloro-2-(2,4-dichlorophenoxy)-phenol) and Triclocarban (3,4,4{prime}-trichlorocarbanilide)(both are contained in soap or shampoo for fungicides), p-dichlorobenzene (insecticides for wears) and TCEP(tris-chloroethyl phosphate) were detected. EOX(extracted organic halogen) in the sediments was 5 to 10 times of chlorinated organic compounds detected by GC/MS. Major part of organic halogen was suggested to be included in chlorinated organics formed by bleaching or sterilization.

  16. Chemical intolerance

    DEFF Research Database (Denmark)

    Dantoft, Thomas Meinertz; Andersson, Linus; Nordin, Steven;

    2015-01-01

    Chemical intolerance (CI) is a term used to describe a condition in which the sufferer experiences a complex array of recurrent unspecific symptoms attributed to low-level chemical exposure that most people regard as unproblematic. Severe CI constitutes the distinguishing feature of multiple...... chemical sensitivity (MCS). The symptoms reported by CI subjects are manifold, involving symptoms from multiple organs systems. In severe cases of CI, the condition can cause considerable life-style limitations with severe social, occupational and economic consequences. As no diagnostic tools for CI...

  17. Hazardous Chemicals

    Centers for Disease Control (CDC) Podcasts

    2007-04-10

    Chemicals are a part of our daily lives, providing many products and modern conveniences. With more than three decades of experience, The Centers for Disease Control and Prevention (CDC) has been in the forefront of efforts to protect and assess people's exposure to environmental and hazardous chemicals. This report provides information about hazardous chemicals and useful tips on how to protect you and your family from harmful exposure.  Created: 4/10/2007 by CDC National Center for Environmental Health.   Date Released: 4/13/2007.

  18. Bioactive compounds from Iostephane heterophylla (Asteraceae).

    Science.gov (United States)

    Aguilar, M I; Delgado, G; Hernández, M L; Villarreal, M L

    2001-01-01

    The novel bisabolene sesquiterpenes 3-6, were isolated from Iostephane heterophylla, using bioguided fractionation. The new compounds were determined to be (12R/12S)-12,13-epoxy-xanthorrhizols (3,4) and (12R/12S)-12,13-dihydro-12,13-dihydroxy-xanthorrizols (5,6) and their structures were characterized by analysis of spectroscopic data and by chemical correlation from xanthorrhizol (2). The stereochemistry at C-12 of 5 was deduced using the modified Mosher experiment. Some of the isolated compounds elicited activity against gram positive and gram negative bacteria, levadura and dermatophytes.

  19. Environmental Transport and Fate Process Descriptors for Propellant Compounds

    Science.gov (United States)

    2006-06-01

    partition coefficients and water solubilities of phthalate esters. Journal of Chemical Engineering Data 44(6): 1414-1418. Englehardt, G., and P. R...Tuschall. 1990. Determination of vapor pressures for non-polar and semipolar organic compounds from gas chromatographic retention data. Journal of Chemical Engineering Data 35

  20. Synthesis, Chemistry, and Applications of Heterocyclic Cage Compounds (V)

    Institute of Scientific and Technical Information of China (English)

    WU; Hsien-Jen

    2001-01-01

    The synthesis and chemistry of polycyclic of cage compounds have attracted considerable attention in recent years. The vast majority of the work reported in this area has dealt with carbocylic cage compounds. On the other hand, the synthesis and chemistry of heterocyclic cage compounds have received less attention. Recently, we envisioned that studies on the synthesis and chemistry of heterocyclic cage compounds can greatly expand the scopes and utilities of cage compounds.1 As part of a program that involves the synthesis, chemistry, and application of heterocyclic cage compounds, we report here the synthesis of new thia-oxa-cage compounds and the chemical nature of these thia-cages.  ……

  1. Trichloromethyl compounds - natural background concentrations and fates within and

    DEFF Research Database (Denmark)

    Albers, Christian Nyrop; Hansen, Poul Erik; Jacobsen, Ole Stig

    2010-01-01

    occurrence and cycling of organic compounds with a trichloromethyl moiety in common. The study areas are temperate coniferous forests. Trichloromethyl compounds can be found in all compartments of the forests (groundwater, soil, vegetation and throughfall), but not all compounds in all compartments....... The atmospheric input of trichloromethyl compounds is found to be minor, with significant contributions for trichloroacetic acid (TCAA), only. In top soil, where the formation of the compounds is expected to occur, there is a clear positive relationship between chloroform and trichloroacetyl containing compounds....... Other positive relations occur, which in combination with chlorination experiments performed in the laboratory, point to the fact that all the trichloromethyl compounds may be formed concurrently in the soil, and their subsequent fates then differ due to different physical, chemical and biological...

  2. A New Natural Compound with Cytotoxic Activity from Tripterygium hypoglaucum

    Institute of Scientific and Technical Information of China (English)

    LI Wei; WANG Fang; ZHAO Yu-qing

    2011-01-01

    Objective To find antitumor cOnstituents from Tripterygium hypoglaucum.Methods The chloroform extract of T.hypoglaucum was separated by silica gel column chromatography and preparative HPLC.The structures of compounds isolated were identified by spectral analysis and chemical evidence.Results Seven compounds were isolated and identified as rhein ethyl ester(1),chrysophenol(2),physcion(3),emodin(4),wilfordine(5),wilforgine(6),and wilforine(7).The cytotoxic activities of the compounds against cancer cell lines were assayed.Conclusion Compound 1 is a new natural compound with strong activities against human cancer cell lines (A2780 and OVCAR-3).Compounds 2-4 are isolated from this genus plants for the first time.The possible structure-activity relationship among compounds 1-4 shows that the methoxy group or oxyethyl moiety might be responsible for the cytotoxity.

  3. Organic compounds in carbonaceous meteorites.

    Science.gov (United States)

    Sephton, Mark A

    2002-06-01

    The carbonaceous chondrite meteorites are fragments of asteroids that have remained relatively unprocessed since the formation of the solar system 4.6 billion years ago. These carbon-rich objects contain a variety of extraterrestrial organic molecules that constitute a record of chemical evolution prior to the origin of life. Compound classes include aliphatic hydrocarbons, aromatic hydrocarbons, amino acids, carboxylic acids, sulfonic acids, phosphonic acids, alcohols, aldehydes, ketones, sugars, amines, amides, nitrogen heterocycles, sulfur heterocycles and a relatively abundant high molecular weight macromolecular material. Structural and stable isotopic characteristics suggest that a number of environments may have contributed to the organic inventory, including interstellar space, the solar nebula and the asteroidal meteorite parent body. This review covers work published between 1950 and the present day and cites 193 references.

  4. Chemical compounds exposure and human health: advances on the politics of chemical risk control Exposición a sustancias químicas y salud humana: avances en la política de control del riesgo químico

    Directory of Open Access Journals (Sweden)

    Eduardo de la Peña

    2002-12-01

    Full Text Available Advances on the politics of chemical risk control. Observed deficiencies on the management, elimination and recirculation of chemical products. Therefore, some of the main challenges for the scientific research, environmental health, nature preservation and the environmental management are closely related to the development of validation system of the impact on the environment and on health as well as prevention and elimination techniques of the pollution dumped of the aquatic and terrestrial environment.Avances en la política de control del riesgo químico. Deficiencias observadas en el manejo, eliminación y recirculación de los productos químicos. Por esta razón, los principales retos para la investigación científica, la sanidad ambiental, la conservación de la naturaleza y la gestión medioambiental, están íntimamente relacionados con el desarrollo de sistemas de valoración del impacto en el medio ambiente y en la salud, así como técnicas de prevención y eliminación de la contaminación vertida al medio acuático y terrestre.

  5. 40 CFR 721.3100 - Oligomeric silicic acid ester compound with a hy-droxyl-al-kyla-mine.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Oligomeric silicic acid ester compound... Significant New Uses for Specific Chemical Substances § 721.3100 Oligomeric silicic acid ester compound with a... chemical substance identified generically as oligomeric silicic acid ester compound with...

  6. Heart testing compound

    Science.gov (United States)

    Knapp, F.F. Jr.; Goodman, M.M.

    1983-06-29

    The compound 15-(p-(/sup 125/I)-iodophenyl)-6-tellurapentadecanoic acid is disclosed as a myocardial imaging agent having rapid and pronounced uptake, prolonged myocardial retention, and low in vivo deiodination.

  7. Compound Semiconductor Radiation Detectors

    CERN Document Server

    Owens, Alan

    2012-01-01

    Although elemental semiconductors such as silicon and germanium are standard for energy dispersive spectroscopy in the laboratory, their use for an increasing range of applications is becoming marginalized by their physical limitations, namely the need for ancillary cooling, their modest stopping powers, and radiation intolerance. Compound semiconductors, on the other hand, encompass such a wide range of physical and electronic properties that they have become viable competitors in a number of applications. Compound Semiconductor Radiation Detectors is a consolidated source of information on all aspects of the use of compound semiconductors for radiation detection and measurement. Serious Competitors to Germanium and Silicon Radiation Detectors Wide-gap compound semiconductors offer the ability to operate in a range of hostile thermal and radiation environments while still maintaining sub-keV spectral resolution at X-ray wavelengths. Narrow-gap materials offer the potential of exceeding the spectral resolutio...

  8. Superconductivity in graphite intercalation compounds

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Robert P. [Cavendish Laboratory, University of Cambridge, Madingley Road, Cambridge CB3 0HE (United Kingdom); Weller, Thomas E.; Howard, Christopher A. [Department of Physics & Astronomy, University College of London, Gower Street, London WCIE 6BT (United Kingdom); Dean, Mark P.M. [Department of Condensed Matter Physics and Materials Science, Brookhaven National Laboratory, Upton, NY 11973 (United States); Rahnejat, Kaveh C. [Department of Physics & Astronomy, University College of London, Gower Street, London WCIE 6BT (United Kingdom); Saxena, Siddharth S. [Cavendish Laboratory, University of Cambridge, Madingley Road, Cambridge CB3 0HE (United Kingdom); Ellerby, Mark, E-mail: mark.ellerby@ucl.ac.uk [Department of Physics & Astronomy, University College of London, Gower Street, London WCIE 6BT (United Kingdom)

    2015-07-15

    Highlights: • Historical background of graphite intercalates. • Superconductivity in graphite intercalates and its place in the field of superconductivity. • Recent developments. • Relevant modeling of superconductivity in graphite intercalates. • Interpretations that pertain and questions that remain. - Abstract: The field of superconductivity in the class of materials known as graphite intercalation compounds has a history dating back to the 1960s (Dresselhaus and Dresselhaus, 1981; Enoki et al., 2003). This paper recontextualizes the field in light of the discovery of superconductivity in CaC{sub 6} and YbC{sub 6} in 2005. In what follows, we outline the crystal structure and electronic structure of these and related compounds. We go on to experiments addressing the superconducting energy gap, lattice dynamics, pressure dependence, and how these relate to theoretical studies. The bulk of the evidence strongly supports a BCS superconducting state. However, important questions remain regarding which electronic states and phonon modes are most important for superconductivity, and whether current theoretical techniques can fully describe the dependence of the superconducting transition temperature on pressure and chemical composition.

  9. Compound composite odontoma.

    Science.gov (United States)

    Girish, G; Bavle, Radhika M; Singh, Manish Kumar; Prasad, Sahana N

    2016-01-01

    The term odontoma has been used as a descriptor for any tumor of odontogenic origin. It is a growth in which both epithelial and mesenchymal cells exhibits complete differentiation. Odontomas are considered as hamartomas rather than true neoplasm. They are usually discovered on routine radiographic examination. Odontomas, according to the World Health Organization, are classified into complex odontoma and compound odontomas. The present paper reports a case of compound composite odontomas.

  10. Compound composite odontoma

    Directory of Open Access Journals (Sweden)

    G Girish

    2016-01-01

    Full Text Available The term odontoma has been used as a descriptor for any tumor of odontogenic origin. It is a growth in which both epithelial and mesenchymal cells exhibits complete differentiation. Odontomas are considered as hamartomas rather than true neoplasm. They are usually discovered on routine radiographic examination. Odontomas, according to the World Health Organization, are classified into complex odontoma and compound odontomas. The present paper reports a case of compound composite odontomas.

  11. Chemistry of peroxide compounds

    Science.gov (United States)

    Volnov, I. I.

    1981-01-01

    The history of Soviet research from 1866 to 1967 on peroxide compounds is reviewed. This research dealt mainly with peroxide kinetics, reactivity and characteristics, peroxide production processes, and more recently with superoxides and ozonides and emphasis on the higher oxides of group 1 and 2 elements. Solid state fluidized bed synthesis and production of high purity products based on the relative solubilities of the initial, intermediate, and final compounds and elements in liquid ammonia are discussed.

  12. Reaction diffusion and solid state chemical kinetics handbook

    CERN Document Server

    Dybkov, V I

    2010-01-01

    This monograph deals with a physico-chemical approach to the problem of the solid-state growth of chemical compound layers and reaction-diffusion in binary heterogeneous systems formed by two solids; as well as a solid with a liquid or a gas. It is explained why the number of compound layers growing at the interface between the original phases is usually much lower than the number of chemical compounds in the phase diagram of a given binary system. For example, of the eight intermetallic compounds which exist in the aluminium-zirconium binary system, only ZrAl3 was found to grow as a separate

  13. Quaternary ammonium compounds – New occupational hazards

    Directory of Open Access Journals (Sweden)

    Agnieszka Lipińska-Ojrzanowska

    2014-10-01

    Full Text Available Quaternary ammonium compounds (QACs, quats belong to organic ionic chemical agents which display unique properties of both surfactants and disinfectants. Their wide distribution in the work environment and also in private households brings about new occupational hazards. This paper reviews reports about the health effects of QACs. QACs could play a role of sensitizers and irritants to the skin and mucous membranes. It is suspected that particular QACs can display an immunologic crossreactivity between each other and with other chemical compounds containing ammonium ion, such as muscle relaxants widely used in anesthesia. They may promote the development of airway allergy, however, the background mechanisms are still unclear and need to be further investigated. Until now, a few cases of occupational asthma induced by QACs have been described and their involvement in contact dermatitis has been documented. The possibility of anaphylaxis due to QACs cannot be excluded as well. Med Pr 2014;65(5:675–682

  14. Electrical Properties of Expanded Graphite Intercalation Compounds

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The intercalation compounds of CuCl2 were synthesized with expanded graphite, whose magnitude of the electrical conductivity is about 103S.cm-1. Their electrical conductivity is 3~6 times as high as that of the expanded graphite, and about 10 times as high as that of GIC made of the non-expanded graphite. The microanalysis results of chemical compounds by X-ray energy spectrum scanning of TEM testified that the atomic ratio of chloride and cupric is nonstoichoimetric. The multivalence and exchange of electrovalence of the cupric ion was confirmed by the XPS-ESCA. Vacancy of chlorine anion increases the concentration of charge carrier.The special stage structure, made of graphite and chloride, produces a weak chemical bond belt and provides a carrier space in the direction of GIC layer. These factors develop the electrical properties.

  15. Honey: Chemical composition, stability and authenticity.

    Science.gov (United States)

    da Silva, Priscila Missio; Gauche, Cony; Gonzaga, Luciano Valdemiro; Costa, Ana Carolina Oliveira; Fett, Roseane

    2016-04-01

    The aim of this review is to describe the chemical characteristics of compounds present in honey, their stability when heated or stored for long periods of time and the parameters of identity and quality. Therefore, the chemical characteristics of these compounds were examined, such as sugars, proteins, amino acids, enzymes, organic acids, vitamins, minerals, phenolic and volatile compounds present in honey. The stability of these compounds in relation to the chemical reactions that occur by heating or prolonged storage were also discussed, with increased understanding of the behavior regarding the common processing of honey that may compromise its quality. In addition, the identity and quality standards were described, such as sugars, moisture, acidity, ash and electrical conductivity, color, 5-HMF and diastase activity, along with the minimum and maximum limits established by the Codex Alimentarius.

  16. Fungitoxicity of chemical analogs with heartwood toxins.

    Science.gov (United States)

    Grohs, B M; Kunz, B

    1998-07-01

    Trans-stilbene and tropolone as chemical analogs with naturally occurring fungitoxic heartwood compounds were studied with respect to their fungitoxic potency. While stilbene showed no fungitoxic activity towards the fungi Aureobasidium pullulans var. melanogenum, Penicillium glabrum, and Trichoderma harzianum in the concentrations tested, the minimal inhibiting concentration of tropolone was 10(-3) M for Penicillium glabrum and Trichoderma harzianum, and 10(-5) M for Aureobasidium pullulans var. melanogenum. In all cases, the effect of tropolone was a fungistatic one. Using chemical analogs for assessing the chemical basis of the fungitoxicity of tropolone, this substance proved to be the only compound tested which possesses fungitoxic properties.

  17. Spin state switching in iron coordination compounds

    Directory of Open Access Journals (Sweden)

    Philipp Gütlich

    2013-02-01

    Full Text Available The article deals with coordination compounds of iron(II that may exhibit thermally induced spin transition, known as spin crossover, depending on the nature of the coordinating ligand sphere. Spin transition in such compounds also occurs under pressure and irradiation with light. The spin states involved have different magnetic and optical properties suitable for their detection and characterization. Spin crossover compounds, though known for more than eight decades, have become most attractive in recent years and are extensively studied by chemists and physicists. The switching properties make such materials potential candidates for practical applications in thermal and pressure sensors as well as optical devices.The article begins with a brief description of the principle of molecular spin state switching using simple concepts of ligand field theory. Conditions to be fulfilled in order to observe spin crossover will be explained and general remarks regarding the chemical nature that is important for the occurrence of spin crossover will be made. A subsequent section describes the molecular consequences of spin crossover and the variety of physical techniques usually applied for their characterization. The effects of light irradiation (LIESST and application of pressure are subjects of two separate sections. The major part of this account concentrates on selected spin crossover compounds of iron(II, with particular emphasis on the chemical and physical influences on the spin crossover behavior. The vast variety of compounds exhibiting this fascinating switching phenomenon encompasses mono-, oligo- and polynuclear iron(II complexes and cages, polymeric 1D, 2D and 3D systems, nanomaterials, and polyfunctional materials that combine spin crossover with another physical or chemical property.

  18. Aromatic compounds from three Brazilian Lauraceae species

    Energy Technology Data Exchange (ETDEWEB)

    Batista, Andrea Nastri de Luca; Batista Junior, Joao Marcos; Lopez, Silvia Noeli; Furlan, Maysa; Cavalheiro, Alberto Jose; Silva, Dulce Helena Siqueira; Bolzani, Vanderlan da Silva [UNESP, Araraquara, SP (Brazil). Inst. de Quimica. Dept. de Quimica Organica; Nunomura, Sergio Massayoshi [Instituto Nacional de Pesquisa da Amazonia (INPA), Manaus, AM (Brazil). Dept. de Produtos Naturais; Yoshida, Massayoshi [Centro de Biotecnologia da Amazonia, Manaus, AM (Brazil)

    2010-07-01

    Phytochemical investigations on three Brazilian Lauraceae species from the Cerrado region of Sao Paulo State, Ocotea corymbosa (Meins) Mez., O. elegans Mez. and Persea pyrifolia Nees and Mart. ex Nees resulted in the isolation of flavonoids, an ester of the 4-O-E-caffeoylquinic acid, an aromatic sesquiterpene besides furofuran lignans. This is the first chemical study on the leaves of Ocotea elegans and O. corymbosa as well as the first report of non-volatile compounds from Persea pyrifolia. (author)

  19. Enzyme catalytic nitration of aromatic compounds.

    Science.gov (United States)

    Kong, Mingming; Wang, Kun; Dong, Runan; Gao, Haijun

    2015-06-01

    Nitroaromatic compounds are important intermediates in organic synthesis. The classic method used to synthesize them is chemical nitration, which involves the use of nitric acid diluted in water or acetic acid, both harmful to the environment. With the development of green chemistry, environmental friendly enzyme catalysis is increasingly employed in chemical processes. In this work, we adopted a non-aqueous horseradish peroxidase (HRP)/NaNO2/H2O2 reaction system to study the structural characteristics of aromatic compounds potentially nitrated by enzyme catalysis, as well as the relationship between the charges on carbon atoms in benzene ring and the nitro product distribution. Investigation of various reaction parameters showed that mild reaction conditions (ambient temperature and neutral pH), plus appropriate use of H2O2 and NaNO2 could prevent inactivation of HRP and polymerization of the substrates. Compared to aqueous-organic co-solvent reaction media, the aqueous-organic two-liquid phase system had great advantages in increasing the dissolved concentration of substrate and alleviating substrate inhibition. Analysis of the aromatic compounds' structural characteristics indicated that substrates containing substituents of NH2 or OH were readily catalyzed. Furthermore, analysis of the relationship between natural bond orbital (NBO) charges on carbon atoms in benzene ring, as calculated by the density functional method, and the nitro product distribution characteristics, demonstrated that the favored nitration sites were the ortho and para positions of substituents in benzene ring, similar to the selectivity of chemical nitration.

  20. Highly trifluoromethylated platinum compounds.

    Science.gov (United States)

    Martínez-Salvador, Sonia; Forniés, Juan; Martín, Antonio; Menjón, Babil

    2011-07-11

    The homoleptic, square-planar organoplatinum(II) compound [NBu(4)](2) [Pt(CF(3))(4)] (1) undergoes oxidative addition of CF(3) I under mild conditions to give rise to the octahedral organoplatinum(IV) complex [NBu(4)](2) [Pt(CF(3))(5)I] (2). This highly trifluoromethylated species reacts with Ag(+) salts of weakly coordinating anions in Me(2)CO under a wet-air stream to afford the aquo derivative [NBu(4)][Pt(CF(3))(5) (OH(2))] (4) in around 75% yield. When the reaction of 2 with the same Ag(+) salts is carried out in MeCN, the solvento compound [NBu(4) ][Pt(CF(3))(5)(NCMe)] (5) is obtained in around 80% yield. The aquo ligand in 4 as well as the MeCN ligand in 5 are labile and can be cleanly replaced by neutral and anionic ligands to furnish a series of pentakis(trifluoromethyl)platinate(IV) compounds with formulae [NBu(4)][Pt(CF(3))(5) (L)] (L=CO (6), pyridine (py; 7), tetrahydrothiophene (tht; 8)) and [NBu(4)](2) [Pt(CF(3))(5)X] (X=Cl (9), Br (10)). The unusual carbonyl-platinum(IV) derivative [NBu(4)][Pt(CF(3))(5) (CO)] (6) is thermally stable and has a ν(CO) of 2194 cm(-1). The crystal structures of 2⋅CH(2)Cl(2), 5, [PPh(4) ][Pt(CF(3))(5)(CO)] (6'), and 7 have been established by X-ray diffraction methods. Compound 2 has shown itself to be a convenient entry to the chemistry of highly trifluoromethylated platinum compounds. To the best of our knowledge, compounds 2 and 4-10 are the organoelement compounds with the highest CF(3) content to have been isolated and adequately characterized to date.