Development of a silicone-membrane passive sampler for monitoring cylindrospermopsin and microcystin LR-YR-RR in natural waters

NASA Astrophysics Data System (ADS)

Nyoni, Hlengilizwe; Mamba, Bhekie B.; Msagati, Titus A. M.

2017-08-01

Silicone membrane tubes were functionalised by filling them with synthesised γ-Fe2O3 nanoparticles and used as a passive sampling device for monitoring microcystins and cylindrospermopsin in aquatic environments. This novel device was calibrated for the measurement of microcystin and cylindrospermopsin concentrations in water. The effect of temperature and hydrodynamics on the sampler performance was studied in a flow-through system under controlled conditions. The chemical uptake of microcystins (MCs) and cylindrospermopsin (CYN) into the passive sampler remained linear and integrative throughout the exposure period. The rate of accumulation of most of the MC compounds tested was dependent on temperature and flow velocity. The use of 13C labelled polychlorinated biphenyls as performance reference compounds (PRCs) in silicone membrane/γ-Fe2O3 nanoparticle passive sampler, Chemcatcher and polar organic chemical integrative sampler (POCIS) was evaluated. The majority of PRCs improved the semi quantitative nature of water concentration estimated by the three samplers. The corrected sampling rate values of model biotoxin compounds were used to estimate the time-weighted average concentrations in natural cyanobacterial water blooms of the Hartbeespoort dam. The corrected sampling rates RScorr values varied from 0.1140 to 0.5628 Ld-1 between samplers with silicone membrane having the least RScorr values compared to the Chemcatcher and POCIS. The three passive sampling devises provided a more relevant picture of the biotoxin concentration in the Hartbeespoort dam. The results suggested that the three sampling devices are suitable for use in monitoring microcystins and cylindrospermopsin concentrations in aquatic environments.

Phase and period responses of the circadian system of mice (Mus musculus) to light stimuli of different duration.

PubMed

Comas, M; Beersma, D G M; Spoelstra, K; Daan, S

2006-10-01

To understand entrainment of circadian systems to different photoperiods in nature, it is important to know the effects of single light pulses of different durations on the free-running system. The authors studied the phase and period responses of laboratory mice (C57BL6J//OlaHsd) to single light pulses of 7 different durations (1, 3, 4, 6, 9, 12, and 18 h) given once per 11 days in otherwise constant darkness. Light-pulse duration affected both amplitude and shape of the phase response curve. Nine-hour light pulses yielded the maximal amplitude PRC. As in other systems, the circadian period slightly lengthened following delays and shortened following advances. The authors aimed to understand how different parts of the light signal contribute to the eventual phase shift. When PRCs were plotted using the onset, midpoint, and end of the pulse as a phase reference, they corresponded best with each other when using the mid-pulse. Using a simple phase-only model, the authors explored the possibility that light affects oscillator velocity strongly in the 1st hour and at reduced strength in later hours of the pulse due to photoreceptor adaptation. They fitted models based on the 1-h PRC to the data for all light pulses. The best overall correspondence between PRCs was obtained when the effect of light during all hours after the first was reduced by a factor of 0.22 relative to the 1st hour. For the predicted PRCs, the light action centered on average at 38% of the light pulse. This is close to the reference phase yielding best correspondence at 36% of the pulses. The result is thus compatible with an initial major contribution of the onset of the light pulse followed by a reduced effect of light responsible for the differences between PRCs for different duration pulses. The authors suggest that the mid-pulse is a better phase reference than lights-on to plot and compare PRCs of different light-pulse durations.

Potential problems relative to TDRS/IUS tilt table elevation with failed VRCS

NASA Technical Reports Server (NTRS)

Bell, J.

1980-01-01

Operational concerns and preliminary solution alternatives related to elevating the inertial upper stage/tracking and data relay satellite (IUS/TDRS) with a failed orbiter vernier reaction control system (VRCS) are presented. Problems arise from the combination of TDRS thermal constraints and tilt table constraints (the primary reaction control system (PRCS) cannot be used to hold attitude while the tilt table is being elevated), and the problems are compounded by the minimum PRCS attitude deadband. The potential solution options are affected by the launch window, flight profile, crew procedures, vehicle capability and constraints, and flight rules.

Photodegradation of PAHs in passive water samplers.

PubMed

Allan, Ian J; Christensen, Guttorm; Bæk, Kine; Evenset, Anita

2016-04-15

Losses of deuterated polycyclic aromatic hydrocarbons (PAHs) used as performance reference compounds (PRCs) in semipermeable membrane devices deployed at fifteen coastal sampling sites near Harstad harbour in Northern Norway were used to investigate photodegradation of these photosensitive compounds. Unusual PRC dissipation profiles, especially for samplers exposed <5m below the water surface are indicative of photodegradation. A strong correlation between loss rates for d12-chrysene and d12-benzo[e]pyrene with consistently higher losses of the latter was found. The observed photodegradation rates may be sufficiently high to impact PAH masses absorbed by a factor of two. This study demonstrates that photodegradation during exposure of passive water samplers needs to be taken into account, particularly with deployments close to the water surface, when using SPMD canisters, or when sampling in the Arctic. Copyright © 2016 Elsevier Ltd. All rights reserved.

Passive sampling to measure baseline dissolved persistent organic pollutant concentrations in the water column of the Palos Verdes Shelf Superfund site.

PubMed

Fernandez, Loretta A; Lao, Wenjian; Maruya, Keith A; White, Carmen; Burgess, Robert M

2012-11-06

Passive sampling was used to deduce water concentrations of persistent organic pollutants (POPs) in the vicinity of a marine Superfund site on the Palos Verdes Shelf, California, USA. Precalibrated solid phase microextraction (SPME) fibers and polyethylene (PE) strips that were preloaded with performance reference compounds (PRCs) were codeployed for 32 d along an 11-station gradient at bottom, surface, and midwater depths. Retrieved samplers were analyzed for DDT congeners and their breakdown products (DDE, DDD, DDMU, and DDNU) and 43 PCB congeners using GC-EI- and NCI-MS. PRCs were used to calculate compound-specific fractional equilibration achieved in situ for the PE samplers, using both an exponential approach to equilibrium (EAE) and numerical integration of Fickian diffusion (NI) models. The highest observed concentrations were for p,p'-DDE, with 2200 and 990 pg/L deduced from PE and SPME, respectively. The difference in these estimates could be largely attributed to uncertainty in equilibrium partition coefficients, unaccounted for disequilibrium between samplers and water, or different time scales over which the samplers average. The concordance between PE and SPME estimated concentrations for DDE was high (R(2) = 0.95). PCBs were only detected in PE samplers, due to their much larger size. Near-bottom waters adjacent to and down current from sediments with the highest bulk concentrations exhibited aqueous concentrations of DDTs and PCBs that exceeded Ambient Water Quality Criteria (AWQC) for human and aquatic health, indicating the need for future monitoring to determine the effectiveness of remedial activities taken to reduce adverse effects of contaminated surface sediments.

Development of polyurethane-based passive samplers for ambient monitoring of urban-use insecticides in water.

PubMed

Liao, Chunyang; Richards, Jaben; Taylor, Allison R; Gan, Jay

2017-12-01

Widespread use of insecticides for the control of urban pests such as ants, termites, and spiders has resulted in contamination and toxicity in urban aquatic ecosystems in different regions of the world. Passive samplers are a convenient and integrative tool for in situ monitoring of trace contaminants in surface water. However, the performance of a passive sampler depends closely on its affinity for the target analytes, making passive samplers highly specific to the types of contaminants being monitored. The goal of this study was to develop a passive sampler compatible with a wide range of insecticides, including the strongly hydrophobic pyrethroids and the weakly hydrophobic fipronil and organophosphates. Of six candidate polymeric thin films, polyurethane film (PU) was identified to be the best at enriching the test compounds. The inclusion of stable isotope labeled analogs as performance reference compounds (PRCs) further allowed the use of PU film for pyrethroids under non-equilibrium conditions. The PU sampler was tested in a large aquarium with circulatory water flow, and also deployed at multiple sites in surface streams in southern California. The concentrations of pesticides derived from the PU sampler ranged from 0.5 to 18.5 ng/L, which were generally lower than the total chemical concentration measured by grab samples, suggesting that suspended particles and dissolved organic matter in water rendered them less available. The influence of suspended particles and dissolved organic matter on bioavailability was more pronounced for pyrethroids than for fipronils. The results show that the developed PU film sampler, when coupled with PRCs, may be used for rapid and sensitive in-situ monitoring of a wide range of insecticides in surface water. Copyright © 2017 Elsevier Ltd. All rights reserved.

A New Approach for Determining Phase Response Curves Reveals that Purkinje Cells Can Act as Perfect Integrators

PubMed Central

Roth, Arnd; Häusser, Michael

2010-01-01

Cerebellar Purkinje cells display complex intrinsic dynamics. They fire spontaneously, exhibit bistability, and via mutual network interactions are involved in the generation of high frequency oscillations and travelling waves of activity. To probe the dynamical properties of Purkinje cells we measured their phase response curves (PRCs). PRCs quantify the change in spike phase caused by a stimulus as a function of its temporal position within the interspike interval, and are widely used to predict neuronal responses to more complex stimulus patterns. Significant variability in the interspike interval during spontaneous firing can lead to PRCs with a low signal-to-noise ratio, requiring averaging over thousands of trials. We show using electrophysiological experiments and simulations that the PRC calculated in the traditional way by sampling the interspike interval with brief current pulses is biased. We introduce a corrected approach for calculating PRCs which eliminates this bias. Using our new approach, we show that Purkinje cell PRCs change qualitatively depending on the firing frequency of the cell. At high firing rates, Purkinje cells exhibit single-peaked, or monophasic PRCs. Surprisingly, at low firing rates, Purkinje cell PRCs are largely independent of phase, resembling PRCs of ideal non-leaky integrate-and-fire neurons. These results indicate that Purkinje cells can act as perfect integrators at low firing rates, and that the integration mode of Purkinje cells depends on their firing rate. PMID:20442875

Evaluating the precision of passive sampling methods using ...

EPA Pesticide Factsheets

To assess these models, four different thicknesses of low-density polyethylene (LDPE) passive samplers were co-deployed for 28 days in the water column at three sites in New Bedford Harbor, MA, USA. Each sampler was pre-loaded with six PCB performance reference compounds (PRCs) to assess equilibrium status, such that the percent of PRC lost would range depending on PRC and LDPE thickness. These data allow subsequent Cfree comparisons to be made in two ways: (1) comparing Cfree derived from one thickness using different models and (2) comparing Cfree derived from the same model using different thicknesses of LDPE. Following the deployments, the percent of PRC lost ranged from 0-100%. As expected, fractional equilibrium decreased with increasing PRC molecular weight as well as sampler thickness. Overall, a total of 27 PCBs (log KOW ranging from 5.07 – 8.09) were measured at Cfree concentrations varying from 0.05 pg/L (PCB 206) to about 200 ng/L (PCB 28) on a single LDPE sampler. Relative standard deviations (RSDs) for total PCB measurements using the same thickness and varying model types range from 0.04-12% and increased with sampler thickness. Total PCB RSD for measurements using the same model and varying thickness ranged from: 6 – 30%. No RSD trends between models were observed but RSD did increase as Cfree decreased. These findings indicate that existing models yield precise and reproducible results when using LDPE and PRCs to measure Cfree. This work in

Parent Resource Centers: An Innovative Mechanism for Parental Involvement in School Choice Decisions

ERIC Educational Resources Information Center

Wao, Hesborn; Hein, Vanessa L.; Villamar, Roger; Chanderbhan-Forde, Susan; Lee, Reginald S.

2017-01-01

This qualitative investigation reports on the use of Parent Resource Centers (PRCs) as a mechanism for parental involvement in public school choice decisions. Interviews with parents and staff at seven PRCs in Florida revealed that PRCs employ multiple strategies to communicate choice information to parents: community-, school- and media-based…

Evaluation of the use of performance reference compounds in an oasis-HLB adsorbent based passive sampler for improving water concentration estimates of polar herbicides in freshwater

USGS Publications Warehouse

Mazzella, N.; Lissalde, S.; Moreira, S.; Delmas, F.; Mazellier, P.; Huckins, J.N.

2010-01-01

Passive samplers such as the Polar Organic Chemical Integrative Sampler (POCIS) are useful tools for monitoring trace levels of polar organic chemicals in aquatic environments. The use of performance reference compounds (PRC) spiked into the POCIS adsorbent for in situ calibration may improve the semiquantitative nature of water concentration estimates based on this type of sampler. In this work, deuterium labeled atrazine-desisopropyl (DIA-d5) was chosen as PRC because of its relatively high fugacity from Oasis HLB (the POCIS adsorbent used) and our earlier evidence of its isotropic exchange. In situ calibration of POCIS spiked with DIA-d5was performed, and the resulting time-weighted average concentration estimates were compared with similar values from an automatic sampler equipped with Oasis HLB cartridges. Before PRC correction, water concentration estimates based on POCIS data sampling ratesfrom a laboratory calibration exposure were systematically lower than the reference concentrations obtained with the automatic sampler. Use of the DIA-d5 PRC data to correct POCIS sampling rates narrowed differences between corresponding values derived from the two methods. Application of PRCs for in situ calibration seems promising for improving POCIS-derived concentration estimates of polar pesticides. However, careful attention must be paid to the minimization of matrix effects when the quantification is performed by HPLC-ESI-MS/MS. ?? 2010 American Chemical Society.

Evaluation of polar organic chemical integrative and hollow fibre samplers for the determination of a wide variety of organic polar compounds in seawater.

PubMed

Mijangos, Leire; Ziarrusta, Haizea; Prieto, Ailette; Zugazua, Oihane; Zuloaga, Olatz; Olivares, Maitane; Usobiaga, Aresatz; Paschke, Albrecht; Etxebarria, Nestor

2018-08-01

The calibration of two passive samplers for the determination of 20 emerging organic compounds in seawater is described in this work: i) a new version of polar organic chemical integrative sampler (POCIS) containing 100 mg of mixed-mode anion exchanger (Strata X-AW) and 100 mg of polymeric HLB (Plexa) sorbent materials and using a highly porous Nylon membrane (30-μm pore size) and ii) polyethersulfone (PES) hollow fibre. Among the studied contaminants, herbicides, hormones, life style products (stimulants and artificial sweeteners), industrial chemicals (corrosion inhibitor and fluorinated compounds), personal care products and several pharmaceuticals were included. In the case of POCIS, both the sorbents and the Nylon membranes were extracted and analysed independently. The calibration set up consisted on a continuous-flow tank that was fed with a continuous flow of seawater (2 L/h) and a stock mixture of contaminants (20 mL/h), assuring a nominal concentration of ~ 600 ng/L (each analyte) in the tank. The uptake was linear in POCIS sorbent and Nylon membranes but exponential for PES hollow fibres. Furthermore, the highest sampling rates (Rs) values were obtained in POCIS sorbent (between 2.7 for acetaminophen and 491 mL/day for perfluoro-n-octanoic acid, PFOA) followed by Nylon membranes (between 3.6 for OBT and 50 mL/day for telmisartan) and the lowest were those from PES fibres (between 1.7 for bezafibrate and 157 mL/day for butylparaben). Additionally, five deuterated compounds ([ 2 H 5 ]-atrazine, [ 2 H 3 ]-amitriptyline, [ 2 H 7 ]-irbesartan, [ 2 H 3 ]-ketoprofen and [ 2 H 9 ]-progesterone) were studied as candidates for performance reference compounds (PRCs) in both POCIS and PES, and though [ 2 H 5 ]-atrazine, [ 2 H 9 ]-progesterone and [ 2 H 3 ]-amitriptyline showed acceptable results in the case of POCIS, only [ 2 H 5 ]-atrazine provided a good validation. In the case of PES fibres, the PRC corrections did not provide acceptable results due to a low dissipation of the PRCs. Finally, POCIS were deployed in two sites of the low part of the estuary of Bilbao (northern Spain) from where water samples were also taken and analysed. As a result, in addition to the overall good agreement between the passive and active samplings, passive samplers allowed the determination of several compounds that were below the detection limits in the active sampling. Copyright © 2018. Published by Elsevier B.V.

Determination of deployment specific chemical uptake rates for SDB-RPD Empore disk using a passive flow monitor (PFM).

PubMed

O'Brien, Dominique; Bartkow, Michael; Mueller, Jochen F

2011-05-01

The use of the adsorbent styrenedivinylbenzene-reverse phase sulfonated (SDB-RPD) Empore disk in a chemcatcher type passive sampler is routinely applied in Australia when monitoring herbicides in aquatic environments. One key challenge in the use of passive samplers is mitigating the potentially confounding effects of varying flow conditions on chemical uptake by the passive sampler. Performance reference compounds (PRCs) may be applied to correct sampling rates (R(s)) for site specific changed in flow and temperature however evidence suggests the use of PRCs is unreliable when applied to adsorbent passive samplers. The use of the passive flow monitor (PFM) has been introduced for the assessment of site-specific changes in water flow. In the presented study we have demonstrated that the R(s) at which both atrazine and prometryn are accumulated within the SDB-RPD-Empore disk is dependent on the flow conditions. Further, the calibration of the measured R(s) for chemical uptake by the SDB-RPD-Empore disk to the mass lost from the PFM has shown that the PFM provides an accurate measure of R(s) for flow velocities from 0 to 16cms(-1). Notably, for flow rates >16cms(-1), a non linear increase in the R(s) of both herbicides was observed which indicates that the key resistance to uptake into the SDB-RPD Empore disk is associated with the diffusion through the overlying diffusion limiting membrane. Overall the greatest uncertainty remains at very low flow conditions, which are unlikely to often occur in surface waters. Validation of the PFM use has also been undertaken in a limited field study. Copyright © 2011 Elsevier Ltd. All rights reserved.

Shuttle PRCS plume contamination analysis for Astro-2 mission

NASA Technical Reports Server (NTRS)

Wang, Francis C.; Greene, Cindy

1993-01-01

The Astro-2 mission scheduled for Jan. 1995 flight is co-manifested with the Spartan experiment. The Astro instrument array consists of several telescopes operating in the UV spectrum. To obtain the desired 300 observations with the telescope array in a shorter time than the Astro-1 mission, it will be necessary to use the primary reaction control system (PRCS) rather than just the Vernier reaction control system. The high mass flow rate of the PRCS engines cause considerable concern about contamination due to PRCS plume return flux. Performance of these instruments depends heavily on the environment they encounter. The ability of the optical system to detect a remote signal depends not only on the intensity of the incoming signal, but also on the ensuing transmission loss through the optical train of the instrument. Performance of these instruments is thus dependent on the properties of the optical surface and the medium through which it propagates. The on-orbit contamination environment will have a strong influence on the performance of these instruments. The finding of a two-month study of the molecular contamination environment of the Astro-2 instruments due to PRCS thruster plumes during the planned Astro-2 mission are summarized.

Unique system of photoreceptors in sea urchin tube feet

PubMed Central

Ullrich-Lüter, Esther M; Dupont, Sam; Arboleda, Enrique; Hausen, Harald; Arnone, Maria Ina

2011-01-01

Different sea urchin species show a vast variety of responses to variations in light intensity; however, despite this behavioral evidence for photosensitivity, light sensing in these animals has remained an enigma. Genome information of the recently sequenced purple sea urchin (Strongylocentrotus purpuratus) allowed us to address this question from a previously unexplored molecular perspective by localizing expression of the rhabdomeric opsin Sp-opsin4 and Sp-pax6, two genes essential for photoreceptor function and development, respectively. Using a specifically designed antibody against Sp-Opsin4 and in situ hybridization for both genes, we detected expression in two distinct groups of photoreceptor cells (PRCs) located in the animal's numerous tube feet. Specific reactivity of the Sp-Opsin4 antibody with sea star optic cushions, which regulate phototaxis, suggests a similar visual function in sea urchins. Ultrastructural characterization of the sea urchin PRCs revealed them to be of a microvillar receptor type. Our data suggest that echinoderms, in contrast to chordates, deploy a microvillar, r-opsin–expressing PRC type for vision, a feature that has been so far documented only in protostome animals. Surprisingly, sea urchin PRCs lack any associated screening pigment. Indeed, one of the tube foot PRC clusters may account for directional vision by being shaded through the opaque calcite skeleton. The PRC axons connect to the animal internal nervous system, suggesting an integrative function beyond local short circuits. Because juveniles display no phototaxis until skeleton completion, we suggest a model in which the entire sea urchin, deploying its skeleton as PRC screening device, functions as a huge compound eye. PMID:21536888

Overview of the US EPA/SERDP/ESTCP: Laboratory, Field ...

EPA Pesticide Factsheets

Passive sampling can be used for applications at contaminated sediment sites including performing assessments of contaminant bioavailability (i.e., freely dissolved concentration (Cfree)), conducting remedial investigations and feasibility studies, and assessing the potential for contaminant bioaccumulation. Previous research articles and documents have discussed many aspects of passive sampling however no definitive guidance on the laboratory, field and analytical procedures for using passive sampling at contaminated sediment sites has been provided. The document discussed in this presentation provides passive sampler users with the guidance necessary to apply the technology to evaluate contaminated sediments. Contaminants discussed include polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs), and the metals, cadmium, copper, nickel, lead and zinc. The document is divided into sections including discussions of different types of samplers used commonly in the United States, the selection and use of performance reference compounds (PRCs), the extraction and instrumental analysis of passive samplers, data analysis and quality assurance/quality control, and a list of passive sampling related references. The document is not intended to serve as a series of standard operating procedures (SOPs) but rather seeks to provide users with the information needed to develop their own SOPs. The document also includes the names of selected passive sam

Building clinical practice in the Palestine Red Crescent operation theatres in Lebanon: reflections from the perspective of an expatriate nurse.

PubMed

Tjoflåt, I; Karlsen, B

2013-12-01

This paper, based on the experience of the first author as an expatriate nurse, aims to describe and discuss some aspects of collaboration that contributed to the building of clinical practice when implementing an operating theatre programme in the Palestine Red Crescent Society (PRCS) hospitals in Lebanon. The operation theatre programme lasted for 8 months: 6 months in 2008 and 2 months in 2009. The programme was part of the partnership project 'Quality of care in the five PRCS hospitals in Lebanon' between the International Committee of the Red Cross and the PRCS Lebanon (PRCS-L) branch. The essential aspects that may have contributed to the building of clinical practice in the operation theatre programme included the expatriate nurse and the Palestine Red Crescent operating theatre nurses working together over time as colleagues, the socio-cultural pedagogic perspective selected for the implementation and the collaboration with the management of the hospitals and counterparts in the PRCS-L branch. One should also note the human and structural issues that seemed to influence the implementation of the programme in a more negative way. This experience may provide insight for other nurses into the importance of working as colleagues, selecting an appropriate pedagogic perspective and establishing productive collaboration with all partners when building clinical practice during a humanitarian mission. © 2013 International Council of Nurses.

Measurement of cyclic volatile methylsiloxanes in the aquatic environment using low-density polyethylene passive sampling devices using an in-field calibration study--challenges and guidance.

PubMed

Bruemmer, Janine; Falcon, Raquel; Greenwood, Richard; Mills, Graham A; Hastie, Colin; Sparham, Chris; van Egmond, Roger

2015-03-01

Cyclic volatile methylsiloxanes (cVMS) are used in personal care products and are hydrophobic, volatile and persistent. Their environmental water concentrations are low and are difficult to detect using conventional sampling methods. This study shows the potential of passive sampling for cVMS. We used low-density polyethylene (LDPE) samplers and in-field calibration methods for octamethylcyclotetrasiloxane (D4) and decamethylcyclopentasiloxane (D5). (13)C-D4 and (13)C-D5, methyltris(trimethylsiloxy)silane (MT), tetrakis(trimethylsiloxy)silane (TK), and five deuterated polycyclic aromatic hydrocarbons (PAHs) were used as performance reference compounds (PRCs). Samplers were calibrated (7-d) using effluent at a treatment plant, with uptake of cVMS and losses of the PRCs measured at 12 time-points. Concentrations of D4 (53ngL(-1)) and D5 (1838ngL(-1)) were stable in the effluent. Uptake of D4 and loss of (13)C-D4 were isotropic and equilibrium was approached by 7-d. Two estimates of sampler uptake rate (Rs) were 2.1Ld(-1) and 2.5Ld(-1). The estimated log LDPE/water partition coefficient was 4.4. The uptake of D5 was slower (Rs=0.32Ld(-1)) and equilibrium was not reached. Offloading of (13)C-D5, MT and TK were slow, and isotropic behaviour was not demonstrated for D5. Offloading of PAHs followed the predicted pattern for LDPE. Uptake of cVMS appeared to be under membrane control, due to low diffusion coefficients in LDPE. Samplers can monitor time-weighted average concentrations of D4 for less than a week, and D5 for longer periods. LDPE samplers allow cVMS to be determined at lower concentrations than by spot sampling methods. Copyright © 2014 Elsevier Ltd. All rights reserved.

Common pathways toward informing policy and environmental strategies to promote health: a study of CDC's Prevention Research Centers.

PubMed

Neri, Elizabeth M; Stringer, Kate J; Spadaro, Antonia J; Ballman, Marie R; Grunbaum, Jo Anne

2015-03-01

This study examined the roles academic researchers can play to inform policy and environmental strategies that promote health and prevent disease. Prevention Research Centers (PRCs) engage in academic-community partnerships to conduct applied public health research. Interviews were used to collect data on the roles played by 32 PRCs to inform policy and environmental strategies that were implemented between September 2009 and September 2010. Descriptive statistics were calculated in SAS 9.2. A difference in roles played was observed depending on whether strategies were policy or environmental. Of the policy initiatives, the most common roles were education, research, and partnership. In contrast, the most prevalent roles the PRCs played in environmental approaches were research and providing health promotion resources. Academic research centers play various roles to help inform policy and environmental strategies. © 2014 Society for Public Health Education.

Measuring nonpolar organic contaminant partitioning in three Norwegian sediments using polyethylene passive samplers.

PubMed

Allan, Ian J; Ruus, Anders; Schaanning, Morten T; Macrae, Kenneth J; Næs, Kristoffer

2012-04-15

Freely dissolved pore water concentrations of polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), penta- and hexachlorobenzene (PeCB and HCB), octachlorostyrene (OCS), p,p'-DDE and p,p'-DDD were measured in bottom sediments from three sites in Norway. Sediments were from Aker Brygge, site of a former shipyard in the inner part of Oslofjord, Frierfjord in the Grenlandsfjord area, impacted during the 50 year-long activity of a magnesium smelter plant, and from Kristiansand harbour, site with high industrial activity. Low density polyethylene (LDPE) membrane samplers were exposed to these sediments in laboratory incubation under constant and low-level agitation for periods of 1, 2, 6, 13, 23 and 50 days. Freely dissolved pore water concentrations were estimated from contaminant masses accumulated and sampling rates obtained from the measurement of kinetics of dissipation of performance reference compounds (PRCs). Marked differences in freely dissolved PAH concentrations and resulting organic carbon-normalised sediment-pore water partition coefficients, logK(TOC), between these three sediments could be observed despite the generally similar total sediment concentrations. In contrast with the PAH data, partitioning of PCBs and other organochlorine compounds (OCs) was relatively similar in all three sediments. For sediments from Frierfjord and Kristiansand, logK(TOC) values were lower for PCBs/OCs than for PAHs, indicating higher availability. Similar partitioning of PAHs and PCBs/OCs was found for sediments from Aker Brygge. No simple logK(oc)-logK(ow) relationships could model these data successfully. These results support the notion that the assessment of the risk posed by these compounds present in sediments in most cases requires actual measurement of contaminant availability. Copyright © 2012 Elsevier B.V. All rights reserved.

Assessing public speaking fear with the short form of the Personal Report of Confidence as a Speaker scale: confirmatory factor analyses among a French-speaking community sample.

PubMed

Heeren, Alexandre; Ceschi, Grazia; Valentiner, David P; Dethier, Vincent; Philippot, Pierre

2013-01-01

The main aim of this study was to assess the reliability and structural validity of the French version of the 12-item version of the Personal Report of Confidence as Speaker (PRCS), one of the most promising measurements of public speaking fear. A total of 611 French-speaking volunteers were administered the French versions of the short PRCS, the Liebowitz Social Anxiety Scale, the Fear of Negative Evaluation scale, as well as the Trait version of the Spielberger State-Trait Anxiety Inventory and the Beck Depression Inventory-II, which assess the level of anxious and depressive symptoms, respectively. Regarding its structural validity, confirmatory factor analyses indicated a single-factor solution, as implied by the original version. Good scale reliability (Cronbach's alpha = 0.86) was observed. The item discrimination analysis suggested that all the items contribute to the overall scale score reliability. The French version of the short PRCS showed significant correlations with the Liebowitz Social Anxiety Scale (r = 0.522), the Fear of Negative Evaluation scale (r = 0.414), the Spielberger State-Trait Anxiety Inventory (r = 0.516), and the Beck Depression Inventory-II (r = 0.361). The French version of the short PRCS is a reliable and valid measure for the evaluation of the fear of public speaking among a French-speaking sample. These findings have critical consequences for the measurement of psychological and pharmacological treatment effectiveness in public speaking fear among a French-speaking sample.

Assessing public speaking fear with the short form of the Personal Report of Confidence as a Speaker scale: confirmatory factor analyses among a French-speaking community sample

PubMed Central

Heeren, Alexandre; Ceschi, Grazia; Valentiner, David P; Dethier, Vincent; Philippot, Pierre

2013-01-01

Background: The main aim of this study was to assess the reliability and structural validity of the French version of the 12-item version of the Personal Report of Confidence as Speaker (PRCS), one of the most promising measurements of public speaking fear. Methods: A total of 611 French-speaking volunteers were administered the French versions of the short PRCS, the Liebowitz Social Anxiety Scale, the Fear of Negative Evaluation scale, as well as the Trait version of the Spielberger State-Trait Anxiety Inventory and the Beck Depression Inventory-II, which assess the level of anxious and depressive symptoms, respectively. Results: Regarding its structural validity, confirmatory factor analyses indicated a single-factor solution, as implied by the original version. Good scale reliability (Cronbach’s alpha = 0.86) was observed. The item discrimination analysis suggested that all the items contribute to the overall scale score reliability. The French version of the short PRCS showed significant correlations with the Liebowitz Social Anxiety Scale (r = 0.522), the Fear of Negative Evaluation scale (r = 0.414), the Spielberger State-Trait Anxiety Inventory (r = 0.516), and the Beck Depression Inventory-II (r = 0.361). Conclusion: The French version of the short PRCS is a reliable and valid measure for the evaluation of the fear of public speaking among a French-speaking sample. These findings have critical consequences for the measurement of psychological and pharmacological treatment effectiveness in public speaking fear among a French-speaking sample. PMID:23662060

Contraceptive information on pregnancy resource center websites: a statewide content analysis.

PubMed

Swartzendruber, Andrea; Steiner, Riley J; Newton-Levinson, Anna

2018-04-24

Most pregnancy resource centers (PRCs) in the US are affiliated with national organizations that have policies against promoting or providing contraceptives, yet many provide information about contraception on their websites. In 2016, the state of Georgia passed a new law to publicly fund PRCs. This study sought to describe the contraceptive information on Georgia PRC websites. We systematically identified all accessible Georgia PRC websites April-June 2016. We downloaded entire websites and used defined protocols to code and thematically analyze content about contraceptives. Of the 64 websites reviewed, 20 (31%) presented information about contraceptives. Most of the content was dedicated to emergency contraception. Emphasis on risks and side effects was the most prominent theme. However, no site presented information about the frequency or prevalence of risks and side effects. Sites also emphasized contraceptive failure and minimized effectiveness. We found a high degree of inaccurate and misleading information about contraceptives. Georgia PRC websites presented skewed information that may undermine confidence in the safety and efficacy of contraceptive methods and discourage use. Public funding for PRCs, an increasing national trend, should be rigorously examined. Increased regulation is urgently needed to ensure that online information about contraceptives presented by publicly funded centers is unbiased, complete and accurate. We examined contraceptive information on Georgia PRC websites and found sites minimize benefits and emphasize barriers to use. They contain high levels of medically inaccurate and misleading information that may undermine public health goals. Public funding for PRCs should be rigorously examined; increased regulation is urgently needed. Copyright © 2018 Elsevier Inc. All rights reserved.

Networked differential GPS system

NASA Technical Reports Server (NTRS)

Sheynblat, Leonid (Inventor); Kalafus, Rudolph M. (Inventor); Loomis, Peter V. W. (Inventor); Mueller, K. Tysen (Inventor)

1994-01-01

An embodiment of the present invention relates to a worldwide network of differential GPS reference stations (NDGPS) that continually track the entire GPS satellite constellation and provide interpolations of reference station corrections tailored for particular user locations between the reference stations Each reference station takes real-time ionospheric measurements with codeless cross-correlating dual-frequency carrier GPS receivers and computes real-time orbit ephemerides independently. An absolute pseudorange correction (PRC) is defined for each satellite as a function of a particular user's location. A map of the function is constructed, with iso-PRC contours. The network measures the PRCs at a few points, so-called reference stations and constructs an iso-PRC map for each satellite. Corrections are interpolated for each user's site on a subscription basis. The data bandwidths are kept to a minimum by transmitting information that cannot be obtained directly by the user and by updating information by classes and according to how quickly each class of data goes stale given the realities of the GPS system. Sub-decimeter-level kinematic accuracy over a given area is accomplished by establishing a mini-fiducial network.

Harnessing and blending the power of two research networks to improve prevention science and public health practice

PubMed Central

Vanderpool, Robin C.; Brownson, Ross C.; Mays, Glen P.; Crosby, Richard A.; Wyatt, Stephen W.

2015-01-01

Strategic collaborations are essential in moving public health research and practice forward1, particularly in light of escalating fiscal and environmental challenges facing the public health community. This commentary provides background and context for an emerging partnership between two national networks, Prevention Research Centers (PRCs) and Public Health Practice-Based Research Networks (PBRNs), to impact public health practice. Supported by CDC, PRCs are celebrating over 25 years of transdisciplinary applied prevention research grounded in community and stakeholder engagement. Public Health PBRNs, funded by the Robert Wood Johnson Foundation, conduct innovative public health services and systems research with public health agencies and community partners to improve public health decision-making. By utilizing each of the networks’ respective strengths and resources, collaborative ventures between PRCs and Public Health PBRNs can enhance the translation of applied prevention research to evidence-based practice and empirically investigate novel public health practices developed in the field. Three current PRC-Public Health PBRNs projects are highlighted and future research directions are discussed. Improving the interconnectedness of prevention research and public health practice is essential to improve the health of the Nation. PMID:24237918

Path Diversity Improved Opportunistic Routing for Underwater Sensor Networks

PubMed Central

Wang, Haiyan; He, Ke

2018-01-01

The packets carried along a pre-defined route in underwater sensor networks are very vulnerble. Node mobility or intermittent channel availability easily leads to unreachable routing. Opportunistic routing has been proven to be a promising paradigm to design routing protocols for underwater sensor networks. It takes advantage of the broadcast nature of the wireless medium to combat packet losses and selects potential paths on the fly. Finding an appropriate forwarding candidate set is a key issue in opportunistic routing. Many existing solutions ignore the impact of candidates location distribution on packet forwarding. In this paper, a path diversity improved candidate selection strategy is applied in opportunistic routing to improve packet forwarding efficiency. It not only maximizes the packet forwarding advancements but also takes the candidate’s location distribution into account. Based on this strategy, we propose two effective routing protocols: position improved candidates selection (PICS) and position random candidates selection (PRCS). PICS employs two-hop neighbor information to make routing decisions. PRCS only uses one-hop neighbor information. Simulation results show that both PICS and PRCS can significantly improve network performance when compared with the previous solutions, in terms of packet delivery ratio, average energy consumption and end-to-end delay. PMID:29690621

Path Diversity Improved Opportunistic Routing for Underwater Sensor Networks.

PubMed

Bai, Weigang; Wang, Haiyan; He, Ke; Zhao, Ruiqin

2018-04-23

The packets carried along a pre-defined route in underwater sensor networks are very vulnerble. Node mobility or intermittent channel availability easily leads to unreachable routing. Opportunistic routing has been proven to be a promising paradigm to design routing protocols for underwater sensor networks. It takes advantage of the broadcast nature of the wireless medium to combat packet losses and selects potential paths on the fly. Finding an appropriate forwarding candidate set is a key issue in opportunistic routing. Many existing solutions ignore the impact of candidates location distribution on packet forwarding. In this paper, a path diversity improved candidate selection strategy is applied in opportunistic routing to improve packet forwarding efficiency. It not only maximizes the packet forwarding advancements but also takes the candidate’s location distribution into account. Based on this strategy, we propose two effective routing protocols: position improved candidates selection (PICS) and position random candidates selection (PRCS). PICS employs two-hop neighbor information to make routing decisions. PRCS only uses one-hop neighbor information. Simulation results show that both PICS and PRCS can significantly improve network performance when compared with the previous solutions, in terms of packet delivery ratio, average energy consumption and end-to-end delay.

Monitoring contaminants of emerging concern from tertiary wastewater treatment plants using passive sampling modelled with performance reference compounds.

PubMed

Sultana, Tamanna; Murray, Craig; Ehsanul Hoque, M; Metcalfe, Chris D

2016-12-01

The Lake Simcoe watershed in Ontario, Canada is an important recreational area and a recharge zone for groundwater resources. Lake Simcoe is a relatively shallow lotic system that has been impacted by urban development, recreation, industry and agriculture. As part of a watershed management plan, six wastewater treatment plants (WWTPs) located in this catchment basin were selected to measure the inputs of contaminants of emerging concern (CECs) of wastewater origin. These WWTPs were recently upgraded to tertiary treatment for phosphorus removal. Polar organic chemical integrative samplers (POCIS) and semipermeable membrane devices (SPMDs) were used to monitor for hydrophilic and hydrophobic CECs, respectively, in treated and untreated wastewater. The passive samplers were calibrated with performance reference compounds (PRCs) by measuring the loss of deuterated beta blocker drugs spiked into POCIS and the loss of PCB congeners spiked into SPMDs over the course of 14-day deployment periods. From the PRC data, field sampling rates of CECs were determined and applied to estimate time-weighted average (TWA) concentrations and mass loadings in mg/day/1000 members of the population serviced. In treated wastewater, TWA concentrations of an antibiotic, sulfamethoxazole, the prescription drugs, carbamazepine, naproxen and gemfibrozil, and the non-prescription drug, ibuprofen, were estimated to be in the low (<18 ng/L) range. The artificial sweeteners, sucralose and acesulfame, were particularly useful chemical tracers, with estimated TWA concentrations in treated wastewater ranging from 128 to 213 ng/L and 4 to 33 ng/L, respectively. The steroid hormones were detected only rarely in treated wastewater. Triclosan, triclocarban and the synthetic musks, HHCB and AHTN, were removed efficiently (>77 %), possibly because of the tertiary treatment technologies. Therefore, the mass loadings for these personal care products were all <5 mg/day/1000 people. Overall, this study indicates that tertiary treatment technologies designed for phosphorus removal do not entirely remove the target CECs.

Laser Mapping for Visual Inspection and Measurement

NASA Technical Reports Server (NTRS)

2006-01-01

Each space shuttle orbiter has 38 Primary Reaction Control System (PRCS) thrusters to help power and position the vehicle for maneuvers in space, including reentry and establishing Earth orbit. Minor flaws in the ceramic lining of a thruster, such as a chip or crack, can cripple the operations of an orbiter in space and jeopardize a mission. The ability to locate, measure, and monitor tiny features in difficult-to-inspect PRCS thrusters improves their overall safety and lifespan. These thrusters have to be detached and visually inspected in great detail at one of two NASA facilities, the White Sands Test Facility or the Kennedy Space Center, before and after each mission, which is an expense of both time and money.

Factors Contributing to Pilot Valve Fuel Seal Extrusion in Orbiter PRCS Thrusters

NASA Technical Reports Server (NTRS)

Waller, J.M.; Saulsberry, R.L.; Albright, John D.

2000-01-01

Extrusion of the polytetrafluoroethylene (PTFE) pilot seal used in the monomethylhydrazine (fuel) valve of the Orbiter Primary Reaction Control System (PRCS) thrusters has been implicated in numerous on-orbit thruster failures and on-ground valve failures. Two extrusion mechanisms have been proposed, one or both may be occurring. The first mechanism is attributed to thermal expansion mismatch between adjacent PTFE and metal parts used in the fuel valve, and is referred to as thermal extrusion. The second mechanism is attributed to nitrogen tetroxide (oxidizer) leakage from the adjacent oxidizer valve on the same thruster during ground turnaround, and is referred to as oxidizer-induced extrusion. Model calculations of PTFE pilot seal in an exact pilot valve configuration show that extrusion can be caused by differential thermal expansion, without the intervening influence of oxidizer. Experimental data on semitrapped PTFE and TFM (modified PTFE) specimens simulating a fuel pilot valve configuration show that thermal extrusion 1) is incremental and irreversible, 2) increases with the size of the thermal excursion, 3) decreases with successive thermal cycling, and 4) is accompanied by gap formation. Both PTFE and TFM exhibit a higher affinity for oxidizer than fuel. The property changes associated with oxidizer uptake may explain why oxidizer seals do not exhibit extrusion. Impression replicas of fuel pilot seals removed from the Orbiter fleet show two types of extrusion: extrusion of the entire seal (loaded extrusion), or extrusion of non-sealing surface (unloaded extrusion). Both extrusion types may arise from differences in service history, rather than in failure mechanism. The plausibility oxidizer-induced extrusion was evaluated. Preliminary calculations suggest that enough energy, heat, or gas may be liberated under certain operational scenarios to cause catastrophic extrusion. However, given the lack of supporting data, conclusions implicating oxidizer leakage as a factor in extrusion must be made with caution.

Academic-health department collaborative relationships are reciprocal and strengthen public health practice: results from a study of academic research centers.

PubMed

Neri, Elizabeth M; Ballman, Marie R; Lu, Hua; Greenlund, Kurt J; Grunbaum, Jo Anne

2014-01-01

Collaborations between academic institutions and state and local health departments have been shown to enhance the public health core functions of Assurance by improving the public health workforce's knowledge and skills. Few studies have analyzed how academic-health department collaborations enhance Assessment and Policy Development core functions. This qualitative study explores types of collaborations between health departments and Prevention Research Centers (PRCs) and how they align with the core functions. Prevention Research Centers are academic institutions funded by the Centers for Disease Control and Prevention to conduct public health research and translate research results for policies and practices. We reviewed each PRC's annual report from fiscal year 2011 and abstracted descriptions of PRC-health department collaborations. We identified 14 themes of PRC-health department collaborations and conducted a qualitative analysis to describe the dimensions and distribution of themes. Of the 37 PRCs, 36 reported 215 collaborations with 19 city, 97 county, 31 state, and 46 tribal health departments. Themes of research, survey, and surveillance aligned with the Assessment core function and evaluation, strategic planning, technical assistance, and program implementation supported the Policy Development and Assurance core functions. Overall, health departments provided on-the-ground expertise to inform PRC research, ensuring its applicability to public health practice. Reciprocally, PRCs improved data quality, increased the scientific rigor of health department processes and programs, and filled knowledge gaps within health departments. Both PRCs and health departments enhanced the relevance of public health programs and practices by grounding implementation and evaluation in community needs and views. Findings from this study demonstrate that PRC-health department collaborations often enhanced multiple core functions that could lead to implementation of evidence-based interventions and continuous quality improvement of public health administration at the local, state, and tribal levels. This study highlights the value and importance of reciprocal academic-health department partnerships.

Calibration of Passive Samplers for the Monitoring of Pharmaceuticals in Water-Sampling Rate Variation.

PubMed

Męczykowska, Hanna; Kobylis, Paulina; Stepnowski, Piotr; Caban, Magda

2017-05-04

Passive sampling is one of the most efficient methods of monitoring pharmaceuticals in environmental water. The reliability of the process relies on a correctly performed calibration experiment and a well-defined sampling rate (R s ) for target analytes. Therefore, in this review the state-of-the-art methods of passive sampler calibration for the most popular pharmaceuticals: antibiotics, hormones, β-blockers and non-steroidal anti-inflammatory drugs (NSAIDs), along with the sampling rate variation, were presented. The advantages and difficulties in laboratory and field calibration were pointed out, according to the needs of control of the exact conditions. Sampling rate calculating equations and all the factors affecting the R s value - temperature, flow, pH, salinity of the donor phase and biofouling - were discussed. Moreover, various calibration parameters gathered from the literature published in the last 16 years, including the device types, were tabled and compared. What is evident is that the sampling rate values for pharmaceuticals are impacted by several factors, whose influence is still unclear and unpredictable, while there is a big gap in experimental data. It appears that the calibration procedure needs to be improved, for example, there is a significant deficiency of PRCs (Performance Reference Compounds) for pharmaceuticals. One of the suggestions is to introduce correction factors for R s values estimated in laboratory conditions.

Calibration of silicone rubber rods as passive samplers for pesticides at two different flow velocities: Modeling of sampling rates under water boundary layer and polymer control.

PubMed

Martin, Alexis; Margoum, Christelle; Jolivet, Antoine; Assoumani, Azziz; El Moujahid, Bachir; Randon, Jérôme; Coquery, Marina

2018-04-01

There is a need to determine time-weighted average concentrations of polar contaminants such as pesticides by passive sampling in environmental waters. Calibration data for silicone rubber-based passive samplers are lacking for this class of compounds. The calibration data, sampling rate (R s ), and partition coefficient between silicone rubber and water (K sw ) were precisely determined for 23 pesticides and 13 candidate performance reference compounds (PRCs) in a laboratory calibration system over 14 d for 2 water flow velocities, 5 and 20 cm s -1 . The results showed that an in situ exposure duration of 7 d left a silicone rubber rod passive sampler configuration in the linear or curvilinear uptake period for 19 of the pesticides studied. A change in the transport mechanism from polymer control to water boundary layer control was observed for pesticides with a log K sw of approximately 3.3. The PRC candidates were not fully relevant to correct the impact of water flow velocity on R s . We therefore propose an alternative method based on an overall resistance to mass transfer model to adjust R s from laboratory experiments to in situ hydrodynamic conditions. We estimated diffusion coefficients (D s ) and thickness of water boundary layer (δ w ) as adjustable model parameters. Log D s values ranged from -12.13 to -10.07 m 2  s -1 . The estimated δ w value showed a power function correlation with water flow velocity. Environ Toxicol Chem 2018;37:1208-1218. © 2017 SETAC. © 2017 SETAC.

Predicting synchrony in heterogeneous pulse coupled oscillators

NASA Astrophysics Data System (ADS)

Talathi, Sachin S.; Hwang, Dong-Uk; Miliotis, Abraham; Carney, Paul R.; Ditto, William L.

2009-08-01

Pulse coupled oscillators (PCOs) represent an ubiquitous model for a number of physical and biological systems. Phase response curves (PRCs) provide a general mathematical framework to analyze patterns of synchrony generated within these models. A general theoretical approach to account for the nonlinear contributions from higher-order PRCs in the generation of synchronous patterns by the PCOs is still lacking. Here, by considering a prototypical example of a PCO network, i.e., two synaptically coupled neurons, we present a general theory that extends beyond the weak-coupling approximation, to account for higher-order PRC corrections in the derivation of an approximate discrete map, the stable fixed point of which can predict the domain of 1:1 phase locked synchronous states generated by the PCO network.

Molecular architecture of polycomb repressive complexes

PubMed Central

Chittock, Emily C.; Latwiel, Sebastian; Miller, Thomas C.R.

2017-01-01

The polycomb group (PcG) proteins are a large and diverse family that epigenetically repress the transcription of key developmental genes. They form three broad groups of polycomb repressive complexes (PRCs) known as PRC1, PRC2 and Polycomb Repressive DeUBiquitinase, each of which modifies and/or remodels chromatin by distinct mechanisms that are tuned by having variable compositions of core and accessory subunits. Until recently, relatively little was known about how the various PcG proteins assemble to form the PRCs; however, studies by several groups have now allowed us to start piecing together the PcG puzzle. Here, we discuss some highlights of recent PcG structures and the insights they have given us into how these complexes regulate transcription through chromatin. PMID:28202673

Intrinsic Cellular Properties and Connectivity Density Determine Variable Clustering Patterns in Randomly Connected Inhibitory Neural Networks

PubMed Central

Rich, Scott; Booth, Victoria; Zochowski, Michal

2016-01-01

The plethora of inhibitory interneurons in the hippocampus and cortex play a pivotal role in generating rhythmic activity by clustering and synchronizing cell firing. Results of our simulations demonstrate that both the intrinsic cellular properties of neurons and the degree of network connectivity affect the characteristics of clustered dynamics exhibited in randomly connected, heterogeneous inhibitory networks. We quantify intrinsic cellular properties by the neuron's current-frequency relation (IF curve) and Phase Response Curve (PRC), a measure of how perturbations given at various phases of a neurons firing cycle affect subsequent spike timing. We analyze network bursting properties of networks of neurons with Type I or Type II properties in both excitability and PRC profile; Type I PRCs strictly show phase advances and IF curves that exhibit frequencies arbitrarily close to zero at firing threshold while Type II PRCs display both phase advances and delays and IF curves that have a non-zero frequency at threshold. Type II neurons whose properties arise with or without an M-type adaptation current are considered. We analyze network dynamics under different levels of cellular heterogeneity and as intrinsic cellular firing frequency and the time scale of decay of synaptic inhibition are varied. Many of the dynamics exhibited by these networks diverge from the predictions of the interneuron network gamma (ING) mechanism, as well as from results in all-to-all connected networks. Our results show that randomly connected networks of Type I neurons synchronize into a single cluster of active neurons while networks of Type II neurons organize into two mutually exclusive clusters segregated by the cells' intrinsic firing frequencies. Networks of Type II neurons containing the adaptation current behave similarly to networks of either Type I or Type II neurons depending on network parameters; however, the adaptation current creates differences in the cluster dynamics compared to those in networks of Type I or Type II neurons. To understand these results, we compute neuronal PRCs calculated with a perturbation matching the profile of the synaptic current in our networks. Differences in profiles of these PRCs across the different neuron types reveal mechanisms underlying the divergent network dynamics. PMID:27812323

Shuttle Primary Reaction Control Subsystem Thruster Fuel Valve Pilot Seal Extrusion: A Failure Correlation

NASA Technical Reports Server (NTRS)

Waller, Jess; Saulsberry, Regor L.

2003-01-01

Pilot operated valves (POVs) are used to control the flow of hypergolic propellants monomethylhydrazine (fuel) and nitrogen tetroxide (oxidizer) to the Shuttle orbiter Primary Reaction Control Subsystem (PRCS) thrusters. The POV incorporates a two-stage design: a solenoid-actuated pilot stage, which in turn controls a pressure-actuated main stage. Isolation of propellant supply from the thruster chamber is accomplished in part by a captive polytetrafluoroethylene (PTFE) pilot seal retained inside a Custom 455.1 stainless steel cavity. Extrusion of the pilot seal restricts the flow of fuel around the pilot poppet, thus impeding or preventing the main valve stage from opening. It can also prevent the main stage from staying open with adequate force margin, particularly if there is gas in the main stage actuation cavity. During thruster operation on-orbit, fuel valve pilot seal extrusion is commonly indicated by low or erratic chamber pressure or failure of the thruster to fire upon command (Fail-Off). During ground turnaround, pilot seal extrusion is commonly indicated by slow gaseous nitrogen (GN2) main valve opening times (greater than 38 ms) or slow water main valve opening response times (greater than 33 ms). Poppet lift tests and visual inspection can also detect pilot seal extrusion during ground servicing; however, direct metrology on the pilot seat assembly provides the most quantitative and accurate means of identifying extrusion. Minimizing PRCS fuel valve pilot seal extrusion has become an important issue in the effort to improve PRCS reliability and reduce associated life cycle costs.

Spectral reconstruction of phase response curves reveals the synchronization properties of mouse globus pallidus neurons

PubMed Central

Atherton, Jeremy F.; Surmeier, D. James

2013-01-01

The propensity of a neuron to synchronize is captured by its infinitesimal phase response curve (iPRC). Determining whether an iPRC is biphasic, meaning that small depolarizing perturbations can actually delay the next spike, if delivered at appropriate phases, is a daunting experimental task because negative lobes in the iPRC (unlike positive ones) tend to be small and may be occluded by the normal discharge variability of a neuron. To circumvent this problem, iPRCs are commonly derived from numerical models of neurons. Here, we propose a novel and natural method to estimate the iPRC by direct estimation of its spectral modes. First, we show analytically that the spectral modes of the iPRC of an arbitrary oscillator are readily measured by applying weak harmonic perturbations. Next, applying this methodology to biophysical neuronal models, we show that a low-dimensional spectral reconstruction is sufficient to capture the structure of the iPRC. This structure was preserved reasonably well even with added physiological scale jitter in the neuronal models. To validate the methodology empirically, we applied it first to a low-noise electronic oscillator with a known design and then to cortical pyramidal neurons, recorded in whole cell configuration, that are known to possess a monophasic iPRC. Finally, using the methodology in conjunction with perforated-patch recordings from pallidal neurons, we show, in contrast to recent modeling studies, that these neurons have biphasic somatic iPRCs. Biphasic iPRCs would cause lateral somatically targeted pallidal inhibition to desynchronize pallidal neurons, providing a plausible explanation for their lack of synchrony in vivo. PMID:23966679

Artificial Neural Network Test Support Development for the Space Shuttle PRCS Thrusters

NASA Technical Reports Server (NTRS)

Lehr, Mark E.

2005-01-01

A significant anomaly, Fuel Valve Pilot Seal Extrusion, is affecting the Shuttle Primary Reaction Control System (PRCS) Thrusters, and has caused 79 to fail. To help address this problem, a Shuttle PRCS Thruster Process Evaluation Team (TPET) was formed. The White Sands Test Facility (WSTF) and Boeing members of the TPET have identified many discrete valve current trace characteristics that are predictive of the problem. However, these are difficult and time consuming to identify and trend by manual analysis. Based on this exhaustive analysis over months, 22 thrusters previously delivered by the Depot were identified as high risk for flight failures. Although these had only recently been installed, they had to be removed from Shuttles OV103 and OV104 for reprocessing, by directive of the Shuttle Project Office. The resulting impact of the thruster removal, replacement, and valve replacement was significant (months of work and hundreds of thousands of dollars). Much of this could have been saved had the proposed Neural Network (NN) tool described in this paper been in place. In addition to the significant benefits to the Shuttle indicated above, the development and implementation of this type of testing will be the genesis for potential Quality improvements across many areas of WSTF test data analysis and will be shared with other NASA centers. Future tests can be designed to incorporate engineering experience via Artificial Neural Nets (ANN) into depot level acceptance of hardware. Additionally, results were shared with a NASA Engineering and Safety Center (NESC) Super Problem Response Team (SPRT). There was extensive interest voiced among many different personnel from several centers. There are potential spin-offs of this effort that can be directly applied to other data acquisition systems as well as vehicle health management for current and future flight vehicles.

Calculating the diffusive flux of persistent organic pollutants between sediments and the water column on the Palos Verdes shelf superfund site using polymeric passive samplers.

PubMed

Fernandez, Loretta A; Lao, Wenjian; Maruya, Keith A; Burgess, Robert M

2014-04-01

Passive samplers were deployed to the seafloor at a marine Superfund site on the Palos Verdes Shelf, California, USA, and used to determine water concentrations of persistent organic pollutants (POPs) in the surface sediments and near-bottom water. A model of Fickian diffusion across a thin water boundary layer at the sediment-water interface was used to calculate flux of contaminants due to molecular diffusion. Concentrations at four stations were used to calculate the flux of DDE, DDD, DDMU, and selected PCB congeners from sediments to the water column. Three passive sampling materials were compared: PE strips, POM strips, and SPME fibers. Performance reference compounds (PRCs) were used with PE and POM to correct for incomplete equilibration, and the resulting POP concentrations, determined by each material, agreed within 1 order of magnitude. SPME fibers, without PRC corrections, produced values that were generally much lower (1 to 2 orders of magnitude) than those measured using PE and POM, indicating that SPME may not have been fully equilibrated with waters being sampled. In addition, diffusive fluxes measured using PE strips at stations outside of a pilot remedial sand cap area were similar to those measured at a station inside the capped area: 240 to 260 ng cm(-2) y(-1) for p,p'-DDE. The largest diffusive fluxes of POPs were calculated at station 8C, the site where the highest sediment concentrations have been measured in the past, 1100 ng cm(-2) y(-1) for p,p'-DDE.

Evaluating the precision of passive sampling methods using PRCs in the water column

EPA Science Inventory

Low-Density polyethylene (LDPE) sheets are often used as passive samplers for aquatic environmental monitoring to measure the dissolved concentrations of hydrophobic organic contaminants (HOCs). HOCs that are freely dissolved in water (Cfree) will partition into the LDPE until a ...

Computation of the phase response curve: a direct numerical approach.

PubMed

Govaerts, W; Sautois, B

2006-04-01

Neurons are often modeled by dynamical systems--parameterized systems of differential equations. A typical behavioral pattern of neurons is periodic spiking; this corresponds to the presence of stable limit cycles in the dynamical systems model. The phase resetting and phase response curves (PRCs) describe the reaction of the spiking neuron to an input pulse at each point of the cycle. We develop a new method for computing these curves as a by-product of the solution of the boundary value problem for the stable limit cycle. The method is mathematically equivalent to the adjoint method, but our implementation is computationally much faster and more robust than any existing method. In fact, it can compute PRCs even where the limit cycle can hardly be found by time integration, for example, because it is close to another stable limit cycle. In addition, we obtain the discretized phase response curve in a form that is ideally suited for most applications. We present several examples and provide the implementation in a freely available Matlab code.

77 FR 75166 - Proposed Data Collections Submitted for Public Comment and Recommendations

Federal Register 2010, 2011, 2012, 2013, 2014

2012-12-19

... (OMB 0920-0650, exp. 6/30/2013). The web-based survey is designed to collect information on the PRCs... days of this notice. Proposed Project Prevention Research Centers Program National Evaluation Reporting... Description The Prevention Research Centers (PRC) Program was established by Congress through the Health...

Plasma rate coefficients for electron-impact ionization of Xeq+ ions (q = 8, …, 17)

NASA Astrophysics Data System (ADS)

Borovik, A., Jr.; Gharaibeh, M. F.; Schippers, S.; Müller, A.

2015-02-01

Plasma rate coefficients (PRCs) for electron-impact single ionization of ground-state Xeq+ ions (q=8,\\ldots ,17) in the temperature range 2 × 105 - 2 × 107 K have been derived from a combination of experimental cross-section data and results of distorted-wave calculations. For Xe8+ and Xe9+ new measurements were performed and thoroughly analyzed with respect to the contributions from different ionization mechanisms and the effects of long-lived excited states in the parent ion beams that had been employed in the experiments. In the same manner, previously published experimental data for the higher charge states were analyzed to extract the ground-configuration ionization cross sections and to derive the associated PRCs. The resulting temperature-dependent PRC functions were parameterized and the associated parameters are provided in tabular form. With the exception of Xe8+ the absolute uncertainties of the inferred rate coefficients are estimated to be +/- 10%. For Xe8+ the uncertainties are +/- 25% due to the necessary correction for strong metastable-ion contributions to the measured cross sections.

Protein restriction cycles reduce IGF-1 and phosphorylated Tau, and improve behavioral performance in an Alzheimer's disease mouse model.

PubMed

Parrella, Edoardo; Maxim, Tom; Maialetti, Francesca; Zhang, Lu; Wan, Junxiang; Wei, Min; Cohen, Pinchas; Fontana, Luigi; Longo, Valter D

2013-04-01

In laboratory animals, calorie restriction (CR) protects against aging, oxidative stress, and neurodegenerative pathologies. Reduced levels of growth hormone and IGF-1, which mediate some of the protective effects of CR, can also extend longevity and/or protect against age-related diseases in rodents and humans. However, severely restricted diets are difficult to maintain and are associated with chronically low weight and other major side effects. Here we show that 4 months of periodic protein restriction cycles (PRCs) with supplementation of nonessential amino acids in mice already displaying significant cognitive impairment and Alzheimer's disease (AD)-like pathology reduced circulating IGF-1 levels by 30-70% and caused an 8-fold increase in IGFBP-1. Whereas PRCs did not affect the levels of β amyloid (Aβ), they decreased tau phosphorylation in the hippocampus and alleviated the age-dependent impairment in cognitive performance. These results indicate that periodic protein restriction cycles without CR can promote changes in circulating growth factors and tau phosphorylation associated with protection against age-related neuropathologies. © 2013 The Authors Aging Cell © 2013 Blackwell Publishing Ltd/Anatomical Society of Great Britain and Ireland.

Optimal Design for Hetero-Associative Memory: Hippocampal CA1 Phase Response Curve and Spike-Timing-Dependent Plasticity

PubMed Central

Miyata, Ryota; Ota, Keisuke; Aonishi, Toru

2013-01-01

Recently reported experimental findings suggest that the hippocampal CA1 network stores spatio-temporal spike patterns and retrieves temporally reversed and spread-out patterns. In this paper, we explore the idea that the properties of the neural interactions and the synaptic plasticity rule in the CA1 network enable it to function as a hetero-associative memory recalling such reversed and spread-out spike patterns. In line with Lengyel’s speculation (Lengyel et al., 2005), we firstly derive optimally designed spike-timing-dependent plasticity (STDP) rules that are matched to neural interactions formalized in terms of phase response curves (PRCs) for performing the hetero-associative memory function. By maximizing object functions formulated in terms of mutual information for evaluating memory retrieval performance, we search for STDP window functions that are optimal for retrieval of normal and doubly spread-out patterns under the constraint that the PRCs are those of CA1 pyramidal neurons. The system, which can retrieve normal and doubly spread-out patterns, can also retrieve reversed patterns with the same quality. Finally, we demonstrate that purposely designed STDP window functions qualitatively conform to typical ones found in CA1 pyramidal neurons. PMID:24204822

Proximity operations analysis: Retrieval of the solar maximum mission observatory

NASA Technical Reports Server (NTRS)

Yglesias, J. A.

1980-01-01

Retrieval of the solar maximum mission (SMM) observatory is feasible in terms of orbiter primary reaction control system (PRCS) plume disturbance of the SMM, orbiter propellant consumed, and flight time required. Man-in-loop simulations will be required to validate these operational techniques before the verification process is complete. Candidate approach and flyaround techniques were developed that allow the orbiter to attain the proper alinement with the SMM for clear access to the grapple fixture (GF) prior grappling. Because the SMM has very little control authority (approximately 14.8 pound-foot-seconds in two axes and rate-damped in the third) it is necessary to inhibit all +Z (upfiring) PRCS jets on the orbiter to avoid tumbling the SMM. A profile involving a V-bar approach and an out-of-plane flyaround appears to be the best choice and is recommended at this time. The flyaround technique consists of alining the +X-axes of the two vehicles parallel with each other and then flying the orbiter around the SMM until the GF is in view. The out-of-plane flyaround technique is applicable to any inertially stabilized payload, and, the entire final approach profile could be considered as standard for most retrieval missions.

Discussing uncertainty and risk in primary care: recommendations of a multi-disciplinary panel regarding communication around prostate cancer screening.

PubMed

Wilkes, Michael; Srinivasan, Malathi; Cole, Galen; Tardif, Richard; Richardson, Lisa C; Plescia, Marcus

2013-11-01

Shared decision making improves value-concordant decision-making around prostate cancer screening (PrCS). Yet, PrCS discussions remain complex, challenging and often emotional for physicians and average-risk men. In July 2011, the Centers for Disease Control and Prevention convened a multidisciplinary expert panel to identify priorities for funding agencies and development groups to promote evidence-based, value-concordant decisions between men at average risk for prostate cancer and their physicians. Two-day multidisciplinary expert panel in Atlanta, Georgia, with structured discussions and formal consensus processes. Sixteen panelists represented diverse specialties (primary care, medical oncology, urology), disciplines (sociology, communication, medical education, clinical epidemiology) and market sectors (patient advocacy groups, Federal funding agencies, guideline-development organizations). Panelists used guiding interactional and evaluation models to identify and rate strategies that might improve PrCS discussions and decisions for physicians, patients and health systems/society. Efficacy was defined as the likelihood of each strategy to impact outcomes. Effort was defined as the relative amount of effort to develop, implement and sustain the strategy. Each strategy was rated (1-7 scale; 7 = maximum) using group process software (ThinkTank(TM)). For each group, intervention strategies were grouped as financial/regulatory, educational, communication or attitudinal levers. For each strategy, barriers were identified. Highly ranked strategies to improve value-concordant shared decision-making (SDM) included: changing outpatient clinic visit reimbursement to reward SDM; development of evidence-based, technology-assisted, point-of-service tools for physicians and patients; reframing confusing prostate cancer screening messages; providing pre-visit decision support interventions; utilizing electronic health records to promote benchmarking/best practices; providing additional training for physicians around value-concordant decision-making; and using re-accreditation to promote training. Conference outcomes present an expert consensus of strategies likely to improve value-concordant prostate cancer screening decisions. In addition, the methodology used to obtain agreement provides a model of successful collaboration around this and future controversial cancer screening issues, which may be of interest to funding agencies, educators and policy makers.

Comparison of Orbiter PRCS Plume Flow Fields Using CFD and Modified Source Flow Codes

NASA Technical Reports Server (NTRS)

Rochelle, Wm. C.; Kinsey, Robin E.; Reid, Ethan A.; Stuart, Phillip C.; Lumpkin, Forrest E.

1997-01-01

The Space Shuttle Orbiter will use Reaction Control System (RCS) jets for docking with the planned International Space Station (ISS). During approach and backout maneuvers, plumes from these jets could cause high pressure, heating, and thermal loads on ISS components. The object of this paper is to present comparisons of RCS plume flow fields used to calculate these ISS environments. Because of the complexities of 3-D plumes with variable scarf-angle and multi-jet combinations, NASA/JSC developed a plume flow-field methodology for all of these Orbiter jets. The RCS Plume Model (RPM), which includes effects of scarfed nozzles and dual jets, was developed as a modified source-flow engineering tool to rapidly generate plume properties and impingement environments on ISS components. This paper presents flow-field properties from four PRCS jets: F3U low scarf-angle single jet, F3F high scarf-angle single jet, DTU zero scarf-angle dual jet, and F1F/F2F high scarf-angle dual jet. The RPM results compared well with plume flow fields using four CFD programs: General Aerodynamic Simulation Program (GASP), Cartesian (CART), Unified Solution Algorithm (USA), and Reacting and Multi-phase Program (RAMP). Good comparisons of predicted pressures are shown with STS 64 Shuttle Plume Impingement Flight Experiment (SPIFEX) data.

Telobox motifs recruit CLF/SWN-PRC2 for H3K27me3 deposition via TRB factors in Arabidopsis.

PubMed

Zhou, Yue; Wang, Yuejun; Krause, Kristin; Yang, Tingting; Dongus, Joram A; Zhang, Yijing; Turck, Franziska

2018-05-01

Polycomb repressive complexes (PRCs) control organismic development in higher eukaryotes through epigenetic gene repression 1-4 . PRC proteins do not contain DNA-binding domains, thus prompting questions regarding how PRCs find their target loci 5 . Here we present genome-wide evidence of PRC2 recruitment by telomere-repeat-binding factors (TRBs) through telobox-related motifs in Arabidopsis. A triple trb1-2, trb2-1, and trb3-2 (trb1/2/3) mutant with a developmental phenotype and a transcriptome strikingly similar to those of strong PRC2 mutants showed redistribution of trimethyl histone H3 Lys27 (H3K27me3) marks and lower H3K27me3 levels, which were correlated with derepression of TRB1-target genes. TRB1-3 physically interacted with the PRC2 proteins CLF and SWN. A SEP3 reporter gene with a telobox mutation showed ectopic expression, which was correlated with H3K27me3 depletion, whereas tethering TRB1 to the mutated cis element partially restored repression. We propose that telobox-related motifs recruit PRC2 through the interaction between TRBs and CLF/SWN, a mechanism essential for H3K27me3 deposition at a subset of target genes.

JPRS Report, East Asia, Southeast Asia.

DTIC Science & Technology

1988-11-30

realignment in the Dewan Rakyat [lower house] be predetermined for the session of Parliament which begins on 10 October. Political observers say that this...Bolikhamsai Banking Operations PASASON 30 AugJ 2 Dollar-Denominated Fuel Prices, Danang Operations Noted fPASASON 20 AugJ 3 MALAYSIA PRCs Tianjin...CompanyDirector JPRS-SEA-88-047 30 November 1988 MALAYSIA PRC’s Tianjin Interested in Importing Products Directly 42050005a Selangor SIN CHEW JIT POH in

Analysis of Eddy Current Capabilities for the Detection of Outer Diameter Stress Corrosion Cracking in Small Bore Metallic Structures

NASA Technical Reports Server (NTRS)

Wincheski, Buzz; Williams, Phillip; Simpson, John

2007-01-01

The use of eddy current techniques for the detection of outer diameter damage in tubing and many complex aerospace structures often requires the use of an inner diameter probe due to a lack of access to the outside of the part. In small bore structures the probe size and orientation are constrained by the inner diameter of the part, complicating the optimization of the inspection technique. Detection of flaws through a significant remaining wall thickness becomes limited not only by the standard depth of penetration, but also geometrical aspects of the probe. Recently, an orthogonal eddy current probe was developed for detection of such flaws in Space Shuttle Primary Reaction Control System (PRCS) Thrusters. In this case, the detection of deeply buried stress corrosion cracking by an inner diameter eddy current probe was sought. Probe optimization was performed based upon the limiting spatial dimensions, flaw orientation, and required detection sensitivity. Analysis of the probe/flaw interaction was performed through the use of finite and boundary element modeling techniques. Experimental data for the flaw detection capabilities, including a probability of detection study, will be presented along with the simulation data. The results of this work have led to the successful deployment of an inspection system for the detection of stress corrosion cracking in Space Shuttle Primary Reaction Control System (PRCS) Thrusters.

The private partners of public health: public-private alliances for public good.

PubMed

McDonnell, Sharon; Bryant, Carol; Harris, Jeff; Campbell, Marci Kramish; Lobb, Ano; Hannon, Peggy A; Cross, Jeffrey L; Gray, Barbara

2009-04-01

We sought to convey lessons learned by the Centers for Disease Control and Prevention's (CDC's) Prevention Research Centers (PRCs) about the value and challenges of private-sector alliances resulting in innovative health promotion strategies. Several PRCs based in a variety of workplace and community settings contributed. We conducted interviews with principal investigators, a literature review, and a review of case studies of private-sector alliances in a microbusiness model, a macrobusiness model, and as multiparty partnerships supporting public health research, implementation, and human resource services. Private-sector alliances provide many advantages, particularly access to specialized skills generally beyond the expertise of public health entities. These skills include manufacturing, distribution, marketing, business planning, and development. Alliances also allow ready access to employee populations. Public health entities can offer private-sector partners funding opportunities through special grants, data gathering and analysis skills, and enhanced project credibility and trust. Challenges to successful partnerships include time and resource availability and negotiating the cultural divide between public health and the private sector. Critical to success are knowledge of organizational culture, values, mission, currency, and methods of operation; an understanding of and ability to articulate the benefits of the alliance for each partner; and the ability and time to respond to unexpected changes and opportunities. Private-public health alliances are challenging, and developing them takes time and resources, but aspects of these alliances can capitalize on partners' strengths, counteract weaknesses, and build collaborations that produce better outcomes than otherwise possible. Private partners may be necessary for program initiation or success. CDC guidelines and support materials may help nurture these alliances.

Human Adolescent Phase Response Curves to Bright White Light.

PubMed

Crowley, Stephanie J; Eastman, Charmane I

2017-08-01

Older adolescents are particularly vulnerable to circadian misalignment and sleep restriction, primarily due to early school start times. Light can shift the circadian system and could help attenuate circadian misalignment; however, a phase response curve (PRC) to determine the optimal time for receiving light and avoiding light is not available for adolescents. We constructed light PRCs for late pubertal to postpubertal adolescents aged 14 to 17 years. Participants completed 2 counterbalanced 5-day laboratory sessions after 8 or 9 days of scheduled sleep at home. Each session included phase assessments to measure the dim light melatonin onset (DLMO) before and after 3 days of free-running through an ultradian light-dark (wake-sleep) cycle (2 h dim [~20 lux] light, 2 h dark). In one session, intermittent bright white light (~5000 lux; four 20-min exposures) was alternated with 10 min of dim room light once per day for 3 consecutive days. The time of light varied among participants to cover the 24-h day. For each individual, the phase shift to bright light was corrected for the free-run derived from the other laboratory session with no bright light. One PRC showed phase shifts in response to light start time relative to the DLMO and another relative to home sleep. Phase delay shifts occurred around the hours corresponding to home bedtime. Phase advances occurred during the hours surrounding wake time and later in the afternoon. The transition from delays to advances occurred at the midpoint of home sleep. The adolescent PRCs presented here provide a valuable tool to time bright light in adolescents.

Actively Shaken In-Situ Passive Sampler Platform for Methylmercury and Organics

DTIC Science & Technology

2016-02-01

Figure 3.2- PRC dissipation and compound uptake kinetics generally assumed for the Performance Reference Compound (PRC) approach...dissipation and compound uptake kinetics generally assumed for the performance reference compound (PRC) approach. C(t) and C(ss) refer to target...under-equilibrated passive sampler measurements that need to be corrected for equilibrium, typically by extrapolation of the loss kinetics of

SSF loads and controllability during assembly

NASA Technical Reports Server (NTRS)

Larson, Charles R.; Ghofranian, S.; Fujii, E.

1993-01-01

The Orbiter Primary Reaction Control System (PRCS) pulse width and firing frequency is restricted to prevent excessive loads in the Space Station Freedom (SSF). The feasibility of using the SSF Control Moment Gyros (CMG) as a secondary controller for load relief is evaluated. The studies revealed the CMG not only reduced loads but were useful for other SSF functions: vibration suppression and modal excitation. Vibration suppression lowers the g level for the SSF micro-g experiments and damps the low frequency oscillations that cause crew sickness. Modal excitation could be used for the modal identification experiment and health monitoring. The CMG's reduced the peak loads and damped the vibrations. They were found to be an effective multi-purpose ancillary device for SSF operation.

Phenolic Compounds in Apple (Malus x domestica Borkh.): Compounds Characterization and Stability during Postharvest and after Processing

PubMed Central

Francini, Alessandra; Sebastiani, Luca

2013-01-01

This paper summarizes the information on the occurrence of phenolic compounds in apple (Malus x domestica Borkh.) fruit and juice, with special reference to their health related properties. As phytochemical molecules belonging to polyphenols are numerous, we will focus on the main apples phenolic compounds with special reference to changes induced by apple cultivar, breeding approaches, fruit postharvest and transformation into juice. PMID:26784345

40 CFR 63.1330 - Wastewater provisions.

Code of Federal Regulations, 2014 CFR

2014-07-01

... through 63.149. (i) When §§ 63.132 through 63.149 refer to table 8 compounds, the owner or operator is....149 refer to table 9 compounds, the owner or operator is only required to consider compounds that meet the definition of organic HAP in § 63.1312 and that are listed on table 9 of 40 CFR part 63, subpart G...

40 CFR 63.1330 - Wastewater provisions.

Code of Federal Regulations, 2013 CFR

2013-07-01

... through 63.149. (i) When §§ 63.132 through 63.149 refer to table 8 compounds, the owner or operator is....149 refer to table 9 compounds, the owner or operator is only required to consider compounds that meet the definition of organic HAP in § 63.1312 and that are listed on table 9 of 40 CFR part 63, subpart G...

Collective phase response curves for heterogeneous coupled oscillators

NASA Astrophysics Data System (ADS)

Hannay, Kevin M.; Booth, Victoria; Forger, Daniel B.

2015-08-01

Phase response curves (PRCs) have become an indispensable tool in understanding the entrainment and synchronization of biological oscillators. However, biological oscillators are often found in large coupled heterogeneous systems and the variable of physiological importance is the collective rhythm resulting from an aggregation of the individual oscillations. To study this phenomena we consider phase resetting of the collective rhythm for large ensembles of globally coupled Sakaguchi-Kuramoto oscillators. Making use of Ott-Antonsen theory we derive an asymptotically valid analytic formula for the collective PRC. A result of this analysis is a characteristic scaling for the change in the amplitude and entrainment points for the collective PRC compared to the individual oscillator PRC. We support the analytical findings with numerical evidence and demonstrate the applicability of the theory to large ensembles of coupled neuronal oscillators.

Primary reaction control system/remote manipulator system interaction with loaded arm. Space shuttle engineering and operations support

NASA Technical Reports Server (NTRS)

Taylor, E. C.; Davis, J. D.

1978-01-01

A study of the interaction between the orbiter primary reaction control system (PRCS) and the remote manipulator system (RMS) with a loaded arm is documented. This analysis was performed with the Payload Deployment and Retrieval Systems Simulation (PDRSS) program with the passive arm bending option. The passive-arm model simulates the arm as massless elastic links with locked joints. The study was divided into two parts. The first part was the evaluation of the response of the arm to step inputs (i.e. constant jet torques) about each of the orbiter body axes. The second part of the study was the evaluation of the response of the arm to minimum impulse primary RCS jet firings with both single pulse and pulse train inputs.

Occurrence of Organic Wastewater Compounds in the Tinkers Creek Watershed and Two Other Tributaries to the Cuyahoga River, Northeast Ohio

USGS Publications Warehouse

Tertuliani, J.S.; Alvarez, D.A.; Furlong, E.T.; Meyer, M.T.; Zaugg, S.D.; Koltun, G.F.

2008-01-01

The U.S. Geological Survey - in cooperation with the Ohio Water Development Authority; National Park Service; Cities of Aurora, Bedford, Bedford Heights, Solon, and Twinsburg; and Portage and Summit Counties - and in collaboration with the Ohio Environmental Protection Agency, did a study to determine the occurrence and distribution of organic wastewater compounds (OWCs) in the Tinkers Creek watershed in northeastern Ohio. In the context of this report, OWCs refer to a wide range of compounds such as antibiotics, prescription and nonprescription pharmaceuticals, personal-care products, household and industrial compounds (for example, antimicrobials, fragrances, surfactants, fire retardants, and so forth) and a variety of other chemicals. Canisters containing polar organic integrative sampler (POCIS) and semipermeable membrane device (SPMD) media were deployed instream for a 28-day period in Mayand June 2006 at locations upstream and downstream from seven wastewater-treatment-plant (WWTP) outfalls in the Tinkers Creek watershed, at a site on Tinkers Creek downstream from all WWTP discharges, and at one reference site each in two nearby watersheds (Yellow Creek and Furnace Run) that drain to the Cuyahoga River. Streambed-sediment samples also were collected at each site when the canisters were retrieved. POCIS and SPMDs are referred to as 'passive samplers' because they sample compounds that they are exposed to without use of mechanical or moving parts. OWCs detected in POCIS and SPMD extracts are referred to in this report as 'detections in water' because both POCIS and SPMDs provided time-weighted measures of concentration in the stream over the exposure period. Streambed sediments also reflect exposure to OWCs in the stream over a long period of time and provide another OWC exposure pathway for aquatic organisms. Four separate laboratory methods were used to analyze for 32 antibiotic, 20 pharmaceutical, 57 to 66 wastewater, and 33 hydrophobic compounds. POCIS and streambed-sediment extracts were analyzed by both the pharmaceutical and wastewater methods. POCIS extracts also were analyzed by the antibiotic method, and SPMD extracts were analyzed by the hydrophobic-compound method. Analytes associated with a given laboratory method are referred to in aggregate by the method name (for example, antibiotic-method analytes are referred to as 'antibiotic compounds') even though some analytes associated with the method may not be strictly classified as such. In addition, some compounds were included in the analyte list for more than one laboratory method. For a given sample matrix, individual compounds detected by more than one analytical method are included independently in counts for each method. A total of 12 antibiotic, 20 pharmaceutical, 41 wastewater, and 22 hydrophobic compounds were detected in water at one or more sites. Eight pharmaceutical and 37 wastewater compounds were detected in streambed sediments. The numbers of detections at reference sites tended to be in the low range of detection counts observed in the Tinkers Creek watershed for a given analytical method. Also, the total numbers of compounds detected in water and sediment at the reference sites were less than the total numbers of compounds detected at sites in the Tinkers Creek watershed. With the exception of hydrophobic compounds, it was common at most sites to have more compounds detected in samples collected downstream from WWTP outfalls than in corresponding samples collected upstream from the outfalls. This was particularly true for antibiotic, pharmaceutical, and wastewater compounds in water. In contrast, it was common to have more hydrophobic compounds detected in samples collected upstream from WWTP outfalls than downstream. Caffeine, fluoranthene, N,N-diethyl-meta-toluamide (DEET), phenanthrene, and pyrene were detected in water at all sites in the Tinkers Creek watershed, irrespective of whether the site was upstream or downs

CBX7 regulates stem cell-like properties of gastric cancer cells via p16 and AKT-NF-κB-miR-21 pathways.

PubMed

Ni, Su-Jie; Zhao, Li-Qin; Wang, Xiao-Feng; Wu, Zhen-Hua; Hua, Rui-Xi; Wan, Chun-Hua; Zhang, Jie-Yun; Zhang, Xiao-Wei; Huang, Ming-Zhu; Gan, Lu; Sun, Hua-Lin; Dimri, Goberdhan P; Guo, Wei-Jian

2018-02-08

Chromobox protein homolog 7 (CBX7), a member of the polycomb group (PcG) family of proteins, is involved in the regulation of cell proliferation and cancer progression. PcG family members, such as BMI, Mel-18, and EZH2, are integral constituents of the polycomb repressive complexes (PRCs) and have been known to regulate cancer stem cell (CSC) phenotype. However, the role of other PRCs' constituents such as CBX7 in the regulation of CSC phenotype remains largely elusive. This study was to investigate the role of CBX7 in regulating stem cell-like properties of gastric cancer and the underlying mechanisms. Firstly, the role of CBX7 in regulating stem cell-like properties of gastric cancer was investigated using sphere formation, Western blot, and xenograft tumor assays. Next, RNA interference and ectopic CBX7 expression were employed to determine the impact of CBX7 on the expression of CSC marker proteins and CSC characteristics. The expression of CBX7, its downstream targets, and stem cell markers were analyzed in gastric stem cell spheres, common cancer cells, and gastric cancer tissues. Finally, the pathways by which CBX7 regulates stem cell-like properties of gastric cancer were explored. We found that CBX7, a constituent of the polycomb repressive complex 1 (PRC1), plays an important role in maintaining stem cell-like characteristics of gastric cancer cells via the activation of AKT pathway and the downregulation of p16. Spearman rank correlation analysis showed positive correlations among the expression of CBX7 and phospho-AKT (pAKT), stem cell markers OCT-4, and CD133 in gastric cancer tissues. In addition, CBX7 was found to upregulate microRNA-21 (miR-21) via the activation of AKT-NF-κB pathway, and miR-21 contributes to CBX7-mediated CSC characteristics. CBX7 positively regulates stem cell-like characteristics of gastric cancer cells by inhibiting p16 and activating AKT-NF-κB-miR-21 pathway.

Anchoring Atmospheric Density Models Using Observed Shuttle Plume Emissions

NASA Astrophysics Data System (ADS)

Dimpfl, W. L.; Bernstien, L. S.

2010-12-01

Atmospheric number densities at a given low-earth orbit (LEO) altitude can vary by more than an order of magnitude, depending on such parameters as diurnal variations and solar activity. The MSIS atmospheric model, which includes these dependent variables as input, is reported as being accurate to ±15%. Improvement to such models requires accurate direct atmospheric measurement. Here, a means of anchoring atmospheric models is offered through measuring the size and shape of atomic line or molecular band radiance resulting from the atmospheric interaction from rocket engine plumes or gas releases in LEO. Many discrete line or band emissions, ranging from the infrared to the ultraviolet may be suitable. For this purpose we are focusing on NH(A→X), centered at 316 nm. This emission is seen in the plumes of the Shuttle Orbiter PRCS engines, is expected in the plume of any amine fueled engine, and can be observed from remote sensors in space or on the ground. The atmospheric interaction of gas releases or plumes from spacecraft in LEO are understood by comparison of observed radiance with that predicted by Direct Simulation Monte Carlo (DSMC) models. The recent Extended Variable Hard Sphere (EVHS) improvements in treating hyperthermal collisions has produced exceptional agreement between measured and modeled steady-state Space Shuttle OMS and PRCS 190-250 nm Cameron band plume radiance from CO(a→X), which is understood to result from a combination of two- and three-step mechanisms. Radiance from NH(A→X) in far field plumes is understood to result from a simpler single-step process of the reaction of a minor plume species with atomic oxygen, making it more suitable for use in determining atmospheric density. It is recommended that direct retrofire burns of amine fueled engines be imaged in a narrow band from remote sensors to reveal atmospheric number density. In principal the simple measurement of the distance between the engine exit and the peak in the steady-state radiance from LEO spacecraft can indicate atmospheric density to ~1% accuracy. Use of this radiance requires calibration by an accurate independent measurement associated with a well-resolved steady-state image of it.

Proposed Oral Reference Dose (RfD) for Barium and Compounds (Final Report, 2004)

EPA Science Inventory

This document is the final report from the 2004 external peer review of the Proposed Oral Reference Dose (RfD) for Barium and Compounds, prepared by the U.S. Environmental Protection Agency (EPA), National Center for Environmental Assessment (NCEA), for the Integrated Risk...

Field Comparison of Passive Air Samplers with Reference Monitors for Ambient Volatile Organic Compounds and Nitrogen Dioxide Under Week-Long Integrals

EPA Science Inventory

This study evaluates performance of nitrogen dioxide NO₂ and volatile organic compounds (VOC) passive samplers with corresponding reference monitors at two sites in the Detroit, Michigan area during the summer of 2005.

Comparison of methods for the prediction of human clearance from hepatocyte intrinsic clearance for a set of reference compounds and an external evaluation set.

PubMed

Yamagata, Tetsuo; Zanelli, Ugo; Gallemann, Dieter; Perrin, Dominique; Dolgos, Hugues; Petersson, Carl

2017-09-01

1. We compared direct scaling, regression model equation and the so-called "Poulin et al." methods to scale clearance (CL) from in vitro intrinsic clearance (CL int ) measured in human hepatocytes using two sets of compounds. One reference set comprised of 20 compounds with known elimination pathways and one external evaluation set based on 17 compounds development in Merck (MS). 2. A 90% prospective confidence interval was calculated using the reference set. This interval was found relevant for the regression equation method. The three outliers identified were justified on the basis of their elimination mechanism. 3. The direct scaling method showed a systematic underestimation of clearance in both the reference and evaluation sets. The "Poulin et al." and the regression equation methods showed no obvious bias in either the reference or evaluation sets. 4. The regression model equation was slightly superior to the "Poulin et al." method in the reference set and showed a better absolute average fold error (AAFE) of value 1.3 compared to 1.6. A larger difference was observed in the evaluation set were the regression method and "Poulin et al." resulted in an AAFE of 1.7 and 2.6, respectively (removing the three compounds with known issues mentioned above). A similar pattern was observed for the correlation coefficient. Based on these data we suggest the regression equation method combined with a prospective confidence interval as the first choice for the extrapolation of human in vivo hepatic metabolic clearance from in vitro systems.

SELECTED ABSTRACTS OF ATOMIC ENERGY PROJECT UNCLASSIFIED REPORT LITERATURE IN THE FIELD OF RADIATION CHEMISTRY AND BIBLIOGRAPHY OF THE PUBLISHED LITERATURE--5TH ANNUAL SUPPLEMENT (PAPERS NOTED UP TO DECEMBER 1960)

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

Clarke, R.W. comp.

1961-05-01

References (2538) are given to U. S. and foreign reports and published literature published from 1957 through 1961. The references contain information on theory, interpretations, water and aqueous inorganic systems, organic compounds (including polymerization reactions and organic coolants), gaseous systems (excluding organic compounds), solid systems (excluding organic compounds), biochemistry and radiobiology (excluding animal studies, including irradiation of foodstuffs, bacteria, and insects), and miscellaneous (including colloids, corrosion, industrial applications of radiation, irradiation equipment, and general reviews and reports). The report references are arranged alphabetically/serially by report reference number, and the open literature rcferences alphabetically by first named author. Separate author andmore » subject indexes are included. (P.C.H.)« less

Compatibility of Elastomeric Seal Compounds with MIL-H-6083 and MIL-H- 46170 Hydraulic Fluid

DTIC Science & Technology

1990-06-01

are also made with results obtained using NBR -L, a reference material cited in AMS 3217. 20. DISTRIBUTION/AVAILABILJTY OF ABSTRACT 21. ABSTRACT...Concurrent comparative studies were conducted using NBR -L, a standard reference compound cited in Aerospace Materials Specification (AMS) 3217. Volume...of a standard reference material such as NBR -L, cited in AMS 3217. Obviously, requirements for fluids and for seals are both dictated by the needs of

Standard and reference materials for marine science. Third edition. Technical memo

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

Cantillo, A.Y.

1992-08-01

The third edition of the catalog of reference materials suited for use in marine science, originally compiled in 1986 for NOAA, IOC, and UNEP. The catalog lists close to 2,000 reference materials from sixteen producers and contains information about their proper use, sources, availability, and analyte concentrations. Indices are included for elements, isotopes, and organic compounds, as are cross references to CAS registry numbers, alternate names, and chemical structures of selected organic compounds. The catalog is being published independently by both NOAA and IOC/UNEP and is available from NOAA/NOS/ORCA in electronic form.

Synthesis, antibacterial activity, synergistic effect, cytotoxicity, docking and molecular dynamics of benzimidazole analogues.

PubMed

Srivastava, Ritika; Gupta, Sunil K; Naaz, Farha; Singh, Anuradha; Singh, Vishal K; Verma, Rajesh; Singh, Nidhi; Singh, Ramendra K

2018-05-24

A series of 2-Cl-benzimidazole derivatives was synthesized and assessed for antibacterial activity. Antibacterial results indicated that compounds 2d, 2e, 3a, 3b, 3c, 4d and 4e showed promising activity against B. cerus, S. aureus and P. aeruginosa (MIC: 6.2 μg/mL) and excellent efficacy against E. coli (MIC: 3.1 μg/mL). Furthermore, compounds 3d and 3e displayed better activity (MIC: 3.1 μg/mL) than the reference drugs chloramphenicol and cycloheximide against gram positive and gram negative bacterial strains. The compounds 3d-e also showed better activity than the reference drug paromomycin against B. cerus and P. aeruginosa and showed similar inhibition pattern against S. aureus and E. coli. (MIC: 3.1 μg/mL). Studies on fractional inhibitory concentration (FIC) determination of compounds 1a-e, 2a-c, 4a-c and the reference antibiotic via combination approach revealed a synergistic effect as the MIC values were lowered up to 1 / 8 th to 1 / 33 rd of the original MIC. In-vitro cytotoxicity study indicated that 2-Cl-benzimidazole derivatives showed less toxicity than the reference used against PBM, CEM and Vero cell lines. Docking studies and MD simulations of compounds on bacterial protein (eubacterial ribosomal decoding A site, PDB: 1j7t) have been conducted to find the possible mode of action of the molecules. In silico ADMET evaluations of compounds 3d and 3e showed promising results comparable to the reference drugs used in this study. Copyright © 2018 Elsevier Ltd. All rights reserved.

Identification of "Known Unknowns" Utilizing Accurate Mass Data and ChemSpider

NASA Astrophysics Data System (ADS)

Little, James L.; Williams, Antony J.; Pshenichnov, Alexey; Tkachenko, Valery

2012-01-01

In many cases, an unknown to an investigator is actually known in the chemical literature, a reference database, or an internet resource. We refer to these types of compounds as "known unknowns." ChemSpider is a very valuable internet database of known compounds useful in the identification of these types of compounds in commercial, environmental, forensic, and natural product samples. The database contains over 26 million entries from hundreds of data sources and is provided as a free resource to the community. Accurate mass mass spectrometry data is used to query the database by either elemental composition or a monoisotopic mass. Searching by elemental composition is the preferred approach. However, it is often difficult to determine a unique elemental composition for compounds with molecular weights greater than 600 Da. In these cases, searching by the monoisotopic mass is advantageous. In either case, the search results are refined by sorting the number of references associated with each compound in descending order. This raises the most useful candidates to the top of the list for further evaluation. These approaches were shown to be successful in identifying "known unknowns" noted in our laboratory and for compounds of interest to others.

EMERGING CONTAMINANTS IN BIOSOLIDS

EPA Science Inventory

Emerging contaminants are receiving increasing media and scientific attention. These chemicals are sometimes referred to as compounds of emerging concern or trace organic compounds, and include several groups of chemicals including endocrine disrupting compounds (EDCs), and phar...

SEURAT-1 liver gold reference compounds: a mechanism-based review.

PubMed

Jennings, Paul; Schwarz, Michael; Landesmann, Brigitte; Maggioni, Silvia; Goumenou, Marina; Bower, David; Leonard, Martin O; Wiseman, Jeffrey S

2014-12-01

There is an urgent need for the development of alternative methods to replace animal testing for the prediction of repeat dose chemical toxicity. To address this need, the European Commission and Cosmetics Europe have jointly funded a research program for 'Safety Evaluation Ultimately Replacing Animal Testing.' The goal of this program was the development of in vitro cellular systems and associated computational capabilities for the prediction of hepatic, cardiac, renal, neuronal, muscle, and skin toxicities. An essential component of this effort is the choice of appropriate reference compounds that can be used in the development and validation of assays. In this review, we focus on the selection of reference compounds for liver pathologies in the broad categories of cytotoxicity and lipid disorders. Mitochondrial impairment, oxidative stress, and apoptosis are considered under the category of cytotoxicity, while steatosis, cholestasis, and phospholipidosis are considered under the category of lipid dysregulation. We focused on four compound classes capable of initiating such events, i.e., chemically reactive compounds, compounds with specific cellular targets, compounds that modulate lipid regulatory networks, and compounds that disrupt the plasma membrane. We describe the molecular mechanisms of these compounds and the cellular response networks which they elicit. This information will be helpful to both improve our understanding of mode of action and help in the selection of appropriate mechanistic biomarkers, allowing us to progress the development of animal-free models with improved predictivity to the human situation.

Towards a full reference library of MS(n) spectra. Testing of a library containing 3126 MS2 spectra of 1743 compounds.

PubMed

Milman, Boris L

2005-01-01

A library consisting of 3766 MS(n) spectra of 1743 compounds, including 3126 MS2 spectra acquired mainly using ion trap (IT) and triple-quadrupole (QqQ) instruments, was composed of numerous collections/sources. Ionization techniques were mainly electrospray ionization and also atmospheric pressure chemical ionization and chemical ionization. The library was tested for the performance in identification of unknowns, and in this context this work is believed to be the largest of all known tests of product-ion mass spectral libraries. The MS2 spectra of the same compounds from different collections were in turn divided into spectra of 'unknown' and reference compounds. For each particular compound, library searches were performed resulting in selection by taking into account the best matches for each spectral collection/source. Within each collection/source, replicate MS2 spectra differed in the collision energy used. Overall, there were up to 950 search results giving the best match factors and their ranks in corresponding hit lists. In general, the correct answers were obtained as the 1st rank in up to 60% of the search results when retrieved with (on average) 2.2 'unknown' and 6.2 reference replicates per compound. With two or more replicates of both 'unknown' and reference spectra (the average numbers of replicates were 4.0 and 7.8, respectively), the fraction of correct answers in the 1st rank increased to 77%. This value is close to the performance of established electron ionization mass spectra libraries (up to 79%) found by other workers. The hypothesis that MS2 spectra better match reference spectra acquired using the same type of tandem mass spectrometer (IT or QqQ) was neither strongly proved nor rejected here. The present work shows that MS2 spectral libraries containing sufficiently numerous different entries for each compound are sufficiently efficient for identification of unknowns and suitable for use with different tandem mass spectrometers. 2005 John Wiley & Sons, Ltd.

Predicting the performance of fingerprint similarity searching.

PubMed

Vogt, Martin; Bajorath, Jürgen

2011-01-01

Fingerprints are bit string representations of molecular structure that typically encode structural fragments, topological features, or pharmacophore patterns. Various fingerprint designs are utilized in virtual screening and their search performance essentially depends on three parameters: the nature of the fingerprint, the active compounds serving as reference molecules, and the composition of the screening database. It is of considerable interest and practical relevance to predict the performance of fingerprint similarity searching. A quantitative assessment of the potential that a fingerprint search might successfully retrieve active compounds, if available in the screening database, would substantially help to select the type of fingerprint most suitable for a given search problem. The method presented herein utilizes concepts from information theory to relate the fingerprint feature distributions of reference compounds to screening libraries. If these feature distributions do not sufficiently differ, active database compounds that are similar to reference molecules cannot be retrieved because they disappear in the "background." By quantifying the difference in feature distribution using the Kullback-Leibler divergence and relating the divergence to compound recovery rates obtained for different benchmark classes, fingerprint search performance can be quantitatively predicted.

Biological evaluation and molecular docking of some chromenyl-derivatives as potential antimicrobial agents.

PubMed

Ionuţ, Ioana; Vodnar, Dan Cristian; Oniga, Ilioara; Oniga, Ovidiu; Tiperciuc, Brînduşa; Tamaian, Radu

2016-01-01

Various thiosemicarbazones (TSCs) and their heterocyclic thiadiazolines (TDZ) possess important biological effects. In addition, chromenyl derivatives exhibit a wide range of pharmacological activities. Based on these findings and as a continuation of our research on nitrogen and sulfur containing compounds, we investigated a series of previously reported chromenyl-TSCs (1a-j) and chromenyl-TDZs (2a-j) for their in vitro antimicrobial activities against two bacterial and four fungal strains. MIC and MBC/MFC (µg/mL) values of these compounds were evaluated and compared to those of Spectinomycin, Moxifloxacin and Fluconazole, used as reference drugs. For a better understanding of the drug-receptor interactions, all the compounds were further subjected to molecular docking against four targets that were chosen based on the specific mechanism of action of the reference drugs used in the antimicrobial screening. All compounds tested showed equal or higher antibacterial/antifungal activities relative to the used reference drugs. In silico studies (molecular docking) revealed that all the investigated compounds showed good binding energies towards four receptor protein targets and supported their antimicrobial properties.

Synchronization scenarios in the Winfree model of coupled oscillators

NASA Astrophysics Data System (ADS)

Gallego, Rafael; Montbrió, Ernest; Pazó, Diego

2017-10-01

Fifty years ago Arthur Winfree proposed a deeply influential mean-field model for the collective synchronization of large populations of phase oscillators. Here we provide a detailed analysis of the model for some special, analytically tractable cases. Adopting the thermodynamic limit, we derive an ordinary differential equation that exactly describes the temporal evolution of the macroscopic variables in the Ott-Antonsen invariant manifold. The low-dimensional model is then thoroughly investigated for a variety of pulse types and sinusoidal phase response curves (PRCs). Two structurally different synchronization scenarios are found, which are linked via the mutation of a Bogdanov-Takens point. From our results, we infer a general rule of thumb relating pulse shape and PRC offset with each scenario. Finally, we compare the exact synchronization threshold with the prediction of the averaging approximation given by the Kuramoto-Sakaguchi model. At the leading order, the discrepancy appears to behave as an odd function of the PRC offset.

USN/USMC Commander’s Quick Reference Legal Handbook

DTIC Science & Technology

2015-01-01

compounds of designer drugs. [See references (a), (f), and (g).] Commanders shall obtain authorization for testing for synthetic drug compounds from...17 Pre-Trial Agreements 19 Post -Trial Review 21 Victim/Witness Issues 23 Section II: Administrative...advocate except in extraordinary circumstances.  Only flag or general officers (and a very few specifically designated non-flag/general officers who are

Inter-laboratory comparison of elemental analysis and gas chromatography combustion isotope ratio mass spectrometry (GC-C-IRMS). Part I: delta13C measurements of selected compounds for the development of an isotopic Grob-test.

PubMed

Serra, F; Janeiro, A; Calderone, G; Rojas, J M Moreno; Rhodes, C; Gonthier, L A; Martin, F; Lees, M; Mosandl, A; Sewenig, S; Hener, U; Henriques, B; Ramalho, L; Reniero, F; Teixeira, A J; Guillou, C

2007-03-01

This study was directed towards investigating suitable compounds to be used as stable isotope reference materials for gas chromatography combustion isotope ratio mass spectrometry (GC-C-IRMS) calibration. Several compounds were selected from those used in the 'Grob-test' mixture. Oxygen- and nitrogen-containing substances were added to these compounds to allow the mixture to be used as a possible multi-isotopic calibration tool for 2H/1H, 13C/12C, 15N/14N and 18O/16O ratio determinations. In this paper we present the results of delta13C measurements performed by the consortium of the five laboratories taking part in this inter-calibration exercise. All the compounds were individually assessed for homogeneity, short-term stability and long-term stability by means of EA-IRMS, as required by the bureau communitaire de reference (BCR) Guide for Production of Certified Reference Materials. The results were compared then with the GC-C-IRMS measurements using both polar and non-polar columns, and the final mixture of selected compounds underwent a further certification exercise assessing limits of accuracy and reproducibility under specified GC-C-IRMS conditions. Copyright 2007 John Wiley & Sons, Ltd.

Synthesis and molecular docking against dihydrofolate reductase of novel pyridin-N-ethyl-N-methylbenzenesulfonamides as efficient anticancer and antimicrobial agents

NASA Astrophysics Data System (ADS)

Debbabi, Khaled F.; Bashandy, Mahmoud S.; Al-Harbi, Sami A.; Aljuhani, Enas H.; Al-Saidi, Hamed M.

2017-03-01

This article describes the synthesis of some novel sulfonamides having biologically active pyridine 21-28. Starting with 4-(1-(2-(2-cyanoacetyl)hydrazono)ethyl)-N-ethyl-N-methylbenzenesulfonamide (2), which was prepared from condensation of acetophenone derivative 1 with 2-cyanoacetohydrazide. Interaction of compound 2 with different aldehydes namely 4-fluorobenzaldehyde, 4-hydroxybenzaldehyde and 4-N,N-dimethylbenzaldehyde afforded the corresponding hydrazono-ethyl-N-ethyl-N-methylbenzene sulfonamides 18-20 respectively, which when reacted with malononitrile and ethyl cyanoacetate afforded compounds 21-26 respectively. These compounds 21-26 can be prepared by another reaction route by interaction of compounds 2 with arylidine malononitrile and arylidine ethyl cyanoacetate in refluxing dioxane in the presence of trimethylamine as catalyst. Interaction of compound 2 with malononitrile and ethyl cyanoacetate afforded oxopyridine derivatives 27 and 28 respectively. All the new prepared compounds were evaluated for their antitumor activities against the cell lines MCF-7 in comparison with the reference drug Doxorubicin using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) colorimetric assay. Compounds 25, 21, 23 with SI values of 9.72, 9.71, 8.81 respectively, exhibited better activity than doxorubicin (Dox) as a reference drug with SI value of 8.49. In addition, compounds 25, 27 and 22 exhibited anti-bacterial activity against gram-negative bacteria (Klebsiella pneumoniae) with inhibition zones 22.6, 20.3 and 19.3 mm respectively, which were more active than gentamicin as a reference drug with inhibition zone 17.3 mm. Molecular Operating Environment (MOE) performed virtual screening using molecular docking studies of the synthesized compounds. The results indicated that some synthesized compounds suitable inhibitor against dihydrofolate reductase (DHFR) enzyme (PDB SD: 4DFR) with further modification.

40 CFR 59.412 - Incorporations by reference.

Code of Federal Regulations, 2011 CFR

2011-07-01

... (CONTINUED) NATIONAL VOLATILE ORGANIC COMPOUND EMISSION STANDARDS FOR CONSUMER AND COMMERCIAL PRODUCTS National Volatile Organic Compound Emission Standards for Architectural Coatings § 59.412 Incorporations by... 19428-2959. (1) ASTM Method C 1315-95, Standard Specification for Liquid Membrane-Forming Compounds...

40 CFR 59.412 - Incorporations by reference.

Code of Federal Regulations, 2013 CFR

2013-07-01

... (CONTINUED) NATIONAL VOLATILE ORGANIC COMPOUND EMISSION STANDARDS FOR CONSUMER AND COMMERCIAL PRODUCTS National Volatile Organic Compound Emission Standards for Architectural Coatings § 59.412 Incorporations by... 19428-2959. (1) ASTM Method C 1315-95, Standard Specification for Liquid Membrane-Forming Compounds...

VOLATILE ORGANIC COMPOUNDS (VOCS) CHAPTER 31.

EPA Science Inventory

The term "volatile organic compounds' (VOCs) was originally coined to refer, as a class, to carbon-containing chemicals that participate in photochemical reactions in the ambient (outdoor) are. The regulatory definition of VOCs used by the U.S. EPA is: Any compound of carbon, ex...

Synthesis, Molecular Docking, and Antimycotic Evaluation of Some 3-Acyl Imidazo[1,2-a]pyrimidines.

PubMed

Gómez-García, Omar; Andrade-Pavón, Dulce; Campos-Aldrete, Elena; Ballinas-Indilí, Ricardo; Méndez-Tenorio, Alfonso; Villa-Tanaca, Lourdes; Álvarez-Toledano, Cecilio

2018-03-07

A series of 3-benzoyl imidazo[1,2- a ]pyrimidines, obtained from N -heteroarylformamidines in good yields, was tested in silico and in vitro for binding and inhibition of seven Candida species ( Candida albicans (ATCC 10231), Candida dubliniensis (CD36), Candida glabrata (CBS138), Candida guilliermondii (ATCC 6260), Candida kefyr , Candida krusei (ATCC 6358) and Candida tropicalis (MYA-3404)). To predict binding mode and energy, each compound was docked in the active site of the lanosterol 14α-demethylase enzyme (CYP51), essential for fungal growth of Candida species. Antimycotic activity was evaluated as the 50% minimum inhibitory concentration (MIC50) for the test compounds and two reference drugs, ketoconazole and fluconazole. All test compounds had a better binding energy (range: -6.11 to -9.43 kcal/mol) than that found for the reference drugs (range: 48.93 to -6.16 kcal/mol). In general, the test compounds showed greater inhibitory activity of yeast growth than the reference drugs. Compounds 4j and 4f were the most active, indicating an important role in biological activity for the benzene ring with electron-withdrawing substituents. These compounds show the best MIC50 against C. guilliermondii and C. glabrata, respectively. The current findings suggest that the 3-benzoyl imidazo[1,2- a ]pyrimidine derivatives, herein synthesized by an accessible methodology, are potential antifungal drugs.

Measurement of absolute concentrations of individual compounds in metabolite mixtures by gradient-selective time-zero 1H-13C HSQC with two concentration references and fast maximum likelihood reconstruction analysis.

PubMed

Hu, Kaifeng; Ellinger, James J; Chylla, Roger A; Markley, John L

2011-12-15

Time-zero 2D (13)C HSQC (HSQC(0)) spectroscopy offers advantages over traditional 2D NMR for quantitative analysis of solutions containing a mixture of compounds because the signal intensities are directly proportional to the concentrations of the constituents. The HSQC(0) spectrum is derived from a series of spectra collected with increasing repetition times within the basic HSQC block by extrapolating the repetition time to zero. Here we present an alternative approach to data collection, gradient-selective time-zero (1)H-(13)C HSQC(0) in combination with fast maximum likelihood reconstruction (FMLR) data analysis and the use of two concentration references for absolute concentration determination. Gradient-selective data acquisition results in cleaner spectra, and NMR data can be acquired in both constant-time and non-constant-time mode. Semiautomatic data analysis is supported by the FMLR approach, which is used to deconvolute the spectra and extract peak volumes. The peak volumes obtained from this analysis are converted to absolute concentrations by reference to the peak volumes of two internal reference compounds of known concentration: DSS (4,4-dimethyl-4-silapentane-1-sulfonic acid) at the low concentration limit (which also serves as chemical shift reference) and MES (2-(N-morpholino)ethanesulfonic acid) at the high concentration limit. The linear relationship between peak volumes and concentration is better defined with two references than with one, and the measured absolute concentrations of individual compounds in the mixture are more accurate. We compare results from semiautomated gsHSQC(0) with those obtained by the original manual phase-cycled HSQC(0) approach. The new approach is suitable for automatic metabolite profiling by simultaneous quantification of multiple metabolites in a complex mixture.

Synthesis, molecular docking, and biological evaluation of some novel hydrazones and pyrazole derivatives as anti-inflammatory agents.

PubMed

Mohammed, Khaled O; Nissan, Yassin M

2014-10-01

2-Hydrazinyl-N-(4-sulfamoylphenyl)acetamide 3 was the key intermediate for the synthesis of novel hydrazones 4-10 and pyrazole derivatives 11-17. All compounds were tested for their in vivo anti-inflammatory activity and their ability to inhibit the production of PGE(2) in serum samples of rats. IC(50) values for the most active compounds for inhibition of COX-1 and COX-2 enzymes were determined in vitro, and they were also tested for their ulcerogenic effect. Molecular docking was performed on the active site of COX-2 to predict their mode of binding to the amino acids. Most of the synthesized compounds showed good anti-inflammatory activity especially compounds 3, 4, 8, 9, 15, and 17 which showed better activity than diclofenac as the reference drug. Compounds 3, 8, 9, 13, and 15-17 were less ulcerogenic than indomethacine as the reference drug. Most of the synthesized compounds interacted with Tyr 385 and Ser 530 in molecular docking study with additional hydrogen bond for compound 17. Compound 17 showed good selectivity index value of 11.1 for COX-1/COX-2 inhibition in vitro. © 2014 John Wiley & Sons A/S.

Compound Identification Using Penalized Linear Regression on Metabolomics

PubMed Central

Liu, Ruiqi; Wu, Dongfeng; Zhang, Xiang; Kim, Seongho

2014-01-01

Compound identification is often achieved by matching the experimental mass spectra to the mass spectra stored in a reference library based on mass spectral similarity. Because the number of compounds in the reference library is much larger than the range of mass-to-charge ratio (m/z) values so that the data become high dimensional data suffering from singularity. For this reason, penalized linear regressions such as ridge regression and the lasso are used instead of the ordinary least squares regression. Furthermore, two-step approaches using the dot product and Pearson’s correlation along with the penalized linear regression are proposed in this study. PMID:27212894

Synthesis of reference compounds related to Chemical Weapons Convention for verification and drug development purposes – a Brazilian endeavour

NASA Astrophysics Data System (ADS)

Cavalcante, S. F. A.; de Paula, R. L.; Kitagawa, D. A. S.; Barcellos, M. C.; Simas, A. B. C.; Granjeiro, J. M.

2018-03-01

This paper deals with challenges that Brazilian Army Organic Synthesis Laboratory has been going through to access reference compounds related to the Chemical Weapons Convention in order to support verification analysis and for research of novel antidotes. Some synthetic procedures to produce the chemicals, as well as Quality Assurance issues and a brief introduction of international agreements banning chemical weapons are also presented.

IRIS Toxicological Review of Beryllium and Compounds (2008 ...

EPA Pesticide Factsheets

EPA is conducting a peer review and public comment of the scientific basis supporting the human health hazard and dose-response assessment of Beryllium that when finalized will appear on the Integrated Risk Information System (IRIS) database. An IRIS Toxicological Review of Beryllium and Compounds was published in 1988 and reassessed in 1998. The current draft (2007) only focuses on the cancer assessment and does not re-evaluate posted reference doses or reference concentrations.

Molecular diversity management strategies for building and enhancement of diverse and focused lead discovery compound screening collections.

PubMed

Schuffenhauer, A; Popov, M; Schopfer, U; Acklin, P; Stanek, J; Jacoby, E

2004-12-01

This publication describes processes for the selection of chemical compounds for the building of a high-throughput screening (HTS) collection for drug discovery, using the currently implemented process in the Discovery Technologies Unit of the Novartis Institute for Biomedical Research, Basel Switzerland as reference. More generally, the currently existing compound acquisition models and practices are discussed. Our informatics, chemistry and biology-driven compound selection consists of two steps: 1) The individual compounds are filtered and grouped into three priority classes on the basis of their individual structural properties. Substructure filters are used to eliminate or penalize compounds based on unwanted structural properties. The similarity of the structures to reference ligands of the main proven druggable target families is computed, and drug-similar compounds are prioritized for the following diversity analysis. 2) The compounds are compared to the archive compounds and a diversity analysis is performed. This is done separately for the prioritized, regular and penalized compounds with increasingly stringent dissimilarity criterion. The process includes collecting vendor catalogues and monitoring the availability of samples together with the selection and purchase decision points. The development of a corporate vendor catalogue database is described. In addition to the selection methods on a per single molecule basis, selection criteria for scaffold and combinatorial chemistry projects in collaboration with compound vendors are discussed.

Novel naproxen/esomeprazole magnesium compound pellets based on acid-independent mechanism: in vitro and in vivo evaluation.

PubMed

Lu, Jing; Kan, Shuling; Zhao, Yi; Zhang, Wenli; Liu, Jianping

2016-09-01

The purpose of this study was to develop the novel naproxen/esomeprazole magnesium compound pellets (novel-NAP/EMZ) depending on EMZ acid-independent mechanism which has been proved to be predominate in the mechanism of co-therapy with nonsteroidal anti-inflammatory drug. The novel-NAP/EMZ compound pellets, composed of NAP colon-specific pellets (NAP-CSPs) and EMZ modified-release pellets (EMZ-MRPs), were prepared by fluid-bed coating technology with desired in vitro release profiles. The resulting pellets were filled into hard gelatin capsules for in vivo evaluation in rats and compared with the reference compound pellets, consisted of NAP enteric-coated pellets (NAP-ECPs) and EMZ immediate-release pellets (EMZ-IRPs). The reference compound pellets were prepared simulating the drug delivery system of VIMOVO(®). In vivo pharmacokinetics, EMZ-MRPs had significantly larger AUC0-t (p < 0.01), 1.67 times more than that of EMZ-IRPs, and prolonged mean residence time (7.55 ± 0.12 h) than that of IRPs (1.46 ± 0.39 h). NAP-CSPs and NAP-ECPs showed similar AUC0-t. Compared to the reference compound pellets, the novel-NAP/EMZ compound pellets did not show distinct differences in histological mucosal morphology. However, biochemical tests exhibited enhanced total antioxidant capacity, increased nitric oxide content and reduced malondialdehyde level for novel-NAP/EMZ compound pellets, indicating that the acid-independent action took effect. The gastric pH values of novel-NAP/EMZ compound pellets were at a low and stable level, which could ensure normal physiological range of human gastric pH. As a result, the novel-NAP/EMZ compound pellets may be a more suitable formulation with potential advantages by improving bioavailability of drug and further reducing undesirable gastrointestinal damages.

Evaluation of in-channel amperometric detection using a dual-channel microchip electrophoresis device and a two-electrode potentiostat for reverse polarity separations

PubMed Central

Meneses, Diogenes; Gunasekara, Dulan B.; Pichetsurnthorn, Pann; da Silva, José A. F.; de Abreu, Fabiane C.; Lunte, Susan M.

2015-01-01

In-channel amperometric detection combined with dual-channel microchip electrophoresis is evaluated using a two-electrode isolated potentiostat for reverse polarity separations. The device consists of two separate channels with the working and reference electrodes placed at identical positions relative to the end of the channel, enabling noise subtraction. In previous reports of this configuration, normal polarity and a three-electrode detection system were used. In the two-electrode detection system described here, the electrode in the reference channel acts as both the counter and reference. The effect of electrode placement in the channels on noise and detector response was investigated using nitrite, tyrosine, and hydrogen peroxide as model compounds. The effects of electrode material and size and type of reference electrode on noise and the potential shift of hydrodynamic voltammograms for the model compounds were determined. In addition, the performance of two- and three-electrode configurations using Pt and Ag/AgCl reference electrodes was compared. Although the signal was attenuated with the Pt reference, the noise was also significantly reduced. It was found that lower LOD were obtained for all three compounds with the dual-channel configuration compared to single-channel, in-channel detection. The dual-channel method was then used for the detection of nitrite in a dermal microdialysis sample obtained from a sheep following nitroglycerin administration. PMID:25256669

Consultation for Human, Veterinary, and Compounded Medications.

PubMed

Moghadam, Gabriella; Forsythe, Lauren Eichstadt

2017-01-01

Providing consultation on medications is a daily responsibility for pharmacists. However, counseling components for veterinary or compounded medications can differ from those for manufactured medications for humans. This article lists the content that should be provided during consultation, describes differences between counseling for human and veterinary patients, and provides references that can be used. Because many veterinary medications are compounded, this article also provides information that should accompany compounded preparations. Copyright© by International Journal of Pharmaceutical Compounding, Inc.

Pattern recognition and classification of vibrational spectra by artificial neural networks

NASA Astrophysics Data System (ADS)

Yang, Husheng

1999-10-01

A drawback of current open-path Fourier transform infrared (OP/FT-IR) systems is that they need a human expert to determine those compounds that may be quantified from a given spectrum. In this study, three types of artificial neural networks were used to alleviate this problem. Firstly, multi-layer feed-forward neural networks were used to automatically recognize compounds in an OP/FT-IR spectrum. Each neural network was trained to recognize one compound in the presence of up to ten interferents in an OP/FT-IR spectrum. The networks were successfully used to recognize five alcohols and two chlorinated compounds in field-measured controlled-release OP/FT-IR spectra of mixtures of these compounds. It has also been demonstrated that a neural network could correctly identify a spectrum in the presence of an interferent that was not included in the training set and could also reject interferents it has not seen before. Secondly, the possibility of using one- and two- dimensional Kohonen self-organizing maps (SOMs) to recognize similarities in low-resolution vapor-phase infrared spectra without any additional information has been investigated. Both full-range reference spectra and open-path window reference spectra were used to train the networks and the trained networks were then used to classify the reference spectra into several groups. The results showed that the SOMs obtained from the two different training sets were quite different, and it is more appropriate to use the second SOM in OP/FT-IR spectrometry. Thirdly, vapor-phase FT-IR reference spectra of five alcohols along with four baseline spectra were encoded as prototype vectors for a Hopfield network. Inclusion of the baseline spectra allowed the network to classify spectra as unknowns, when the reference spectra of these compounds were not stored as prototype vectors in the network. The network could identify each of the 5 alcohols correctly even in the presence of noise and interfering compounds. Finally, one- and two-dimensional Kohonen SOMs were also successfully used for the unsupervised differentiation of the Fourier transform Raman spectra of hardwoods from softwoods. A semi-quantitative method that is based on the Euclidean distances of the weight matrix has been developed to assist the automatic clustering of the neurons in a two-dimensional SOM.

Ozonation of the pharmaceutical compound ranitidine: reactivity and kinetic aspects.

PubMed

Rivas, Javier; Gimeno, Olga; Encinas, Angel; Beltrán, Fernando

2009-07-01

Ranitidine has been ozonated under different operating conditions of pH, applied ozone dose, initial ranitidine concentration and presence or absence of free radical inhibitors. Results of ranitidine evolution with time indicate a high reactivity of this compound with molecular ozone. Mineralization levels achieved in the order of 20-25% suggest that the (CH3)2-N-CH2- moiety bonded to the furan ring could be separated from the rest of the ranitidine structure and further mineralized. Only alkaline conditions (pH=11) are capable of increasing TOC conversion up to values close to 70%. Determination of the direct ozonation rate constant for ranitidine by means of competitive kinetics reveals an unacceptable dependence of the aforementioned constant with the reference compound reactivity. It is hypothesised that only reference compounds with reactivity similar to the target species should be used.

Electrocatalytic cermet gas detector/sensor

DOEpatents

Vogt, Michael C.; Shoemarker, Erika L.; Fraioli, deceased, Anthony V.

1995-01-01

An electrocatalytic device for sensing gases. The gas sensing device includes a substrate layer, a reference electrode disposed on the substrate layer comprised of a nonstoichiometric chemical compound enabling oxygen diffusion therethrough, a lower reference electrode coupled to the reference electrode, a solid electrolyte coupled to the lower reference electrode and an upper catalytically active electrode coupled to the solid electrolyte.

Qualitative Analysis by Gas Chromatography: GC versus the Nose in Formulating Artificial Fruit Flavors.

ERIC Educational Resources Information Center

Rasmussen, P. W.

1984-01-01

Describes an undergraduate laboratory experiment used to illustrate the use of gas chromatography retention indices for the identification of unknown compounds, specifically for the identification of unknown compounds and for the identification of the volatile compounds responsible for the odor of the banana. Procedures, reference data, and sample…

Traditional medicine and gastroprotective crude drugs.

PubMed

Schmeda-Hirschmann, Guillermo; Yesilada, Erdem

2005-08-22

A frequent question when dealing with the search for gastroprotective compounds from natural sources is how far or close are both the plant preparations and extract amounts from the doses recommended in traditional medicine and what should be considered realistic levels for experimental studies. The administration way is oral and therefore extracts and products should be administered by gavage when looking for validation of ethnopharmacological uses. Suggestions of doses for both crude extracts and pure compounds are presented and discussed. For plant extracts prepared from single herbs and herbal mixtures, dose-response studies in the range between 100 and 300 mg/kg are suggested, with more than a single gastric ulcer model either in rats or mice. A suitable reference compound should be used according to the ulcer model and in doses resembling those used for human patients. For pure compounds and structure-activity studies or trends, dose-response results should be provided for at least a parent compound in order to select a reasonable dose for comparison purposes. We suggest an evaluation of the activity of the parent compound in the 50-300 mg/kg range and to look for structural modification leading to derivatives with similar or higher gastroprotective effects than the reference antiulcer compounds.

Quantitation of Flavanols, Proanthocyanidins, Isoflavones, Flavanones, Dihydrochalcones, Stilbenes, Benzoic Acid Derivatives Using Ultraviolet Absorbance after Identification by Liquid Chromatography–Mass Spectrometry

PubMed Central

Lin, Long-Ze; Harnly, James M.

2013-01-01

A general method was developed for the systematic quantitation of flavanols, proanthocyanidins, isoflavones, flavanones, dihydrochalcones, stilbenes, and hydroxybenzoic acid derivatives (mainly hydrolyzable tannins) based on UV band II absorbance arising from the benzoyl structure. The compound structures and the wavelength maximum were well correlated and were divided into four groups: the flavanols and proanthocyanidins at 278 nm, hydrolyzable tannins at 274 nm, flavanones at 288 nm, and isoflavones at 260 nm. Within each group, molar relative response factors (MRRFs) were computed for each compound based on the absorbance ratio of the compound and the group reference standard. Response factors were computed for the compounds as purchased (MRRF), after drying (MRRFD), and as the best predicted value (MRRFP). Concentrations for each compound were computed based on calibration with the group reference standard and the MRRFP. The quantitation of catechins, proanthocyanidins, and gallic acid derivatives in white tea was used as an example. PMID:22577798

Electrocatalytic cermet gas detector/sensor

DOEpatents

Vogt, M.C.; Shoemarker, E.L.; Fraioli, A.V.

1995-07-04

An electrocatalytic device for sensing gases is described. The gas sensing device includes a substrate layer, a reference electrode disposed on the substrate layer comprised of a nonstoichiometric chemical compound enabling oxygen diffusion therethrough, a lower reference electrode coupled to the reference electrode, a solid electrolyte coupled to the lower reference electrode and an upper catalytically active electrode coupled to the solid electrolyte. 41 figs.

High-temperature Y267 epdm elastomer - field and laboratory experiences, August 1981

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

Hirasuna, A.R.; Friese, G.J.; Stephens, G.A.

1982-01-01

During the period 1976 to 1979 L'Garde, Inc. developed geothermal elastomer compounds under a U.S. Department of Energy - Division of Geothermal Energy (DOE-DGE) contract. The resulting developments yielded compounds from 4 polymer systems which successfully exceeded the contract requirements. Since completion of the compound development, significant laboratory and down-hole experience occurred, primarily on the Y267 EPDM compound. This work summarizes those experiences. 11 references.

[Pollution Characteristics of Aldehydes and Ketones Compounds in the Exhaust of Beijing Typical Restaurants].

PubMed

Cheng, Jing-chen; Cui, Tong; He, Wan-qing; Nie, Lei; Wang, Jun-ling; Pan, Tao

2015-08-01

Aldehydes and ketones compounds, as one of the components in the exhaust of restaurants, are a class of volatile organic compounds (VOCs) with strong chemical reactivity. However, there is no systematic study on aldehydes and ketones compounds in the exhaust of restaurants. To further clarify the food source emission levels of aldehydes and ketones compounds and controlling measures, to access city group catering VOCs emissions control decision-making basis, this study selected 8 Beijing restaurants with different types. The aldehydes and ketones compounds were sampled using DNPH-silica tube, and then ultra performance liquid chromatography was used for quantitative measurement. The aldehydes and ketones concentrations of reference volume condition from 8 restaurants in descending order were Roasted Duck restaurant, Chinese Style Barbecue, Home Dishes, Western Fast-food, School Canteen, Chinese Style Fast-food, Sichuan Cuisine, Huaiyang Cuisine. The results showed that the range of aldehydes and ketones compounds (C1-C9) concentrations of reference volume condition in the exhaust of restaurants was 115.47-1035.99 microg x m(-3). The composition of aldehydes and ketones compounds in the exhaust of sampled restaurants was obviously different. The percentages of C1-C3 were above 40% in the exhaust from Chinese style restaurants. Fast food might emit more C4-C9 aldehydes and ketones compounds. From the current situation of existing aldehydes and ketones compounds control, the removal efficiency of high voltage electrostatic purifiers widely used in Beijing is limited.

Investigating a Potential Auxin-Related Mode of Hormetic/Inhibitory Action of the Phytotoxin Parthenin.

PubMed

Belz, Regina G

2016-01-01

Parthenin is a metabolite of Parthenium hysterophorus and is believed to contribute to the weed's invasiveness via allelopathy. Despite the potential of parthenin to suppress competitors, low doses stimulate plant growth. This biphasic action was hypothesized to be auxin-like and, therefore, an auxin-related mode of parthenin action was investigated using two approaches: joint action experiments with Lactuca sativa, and dose-response experiments with auxin/antiauxin-resistant Arabidopsis thaliana genotypes. The joint action approach comprised binary mixtures of subinhibitory doses of the auxin 3-indoleacetic acid (IAA) mixed with parthenin or one of three reference compounds [indole-3-butyric acid (IBA), 2,3,5-triiodobenzoic acid (TIBA), 2-(p-chlorophenoxy)-2-methylpropionic acid (PCIB)]. The reference compounds significantly interacted with IAA at all doses, but parthenin interacted only at low doses indicating that parthenin hormesis may be auxin-related, in contrast to its inhibitory action. The genetic approach investigated the response of four auxin/antiauxin-resistant mutants and a wildtype to parthenin or two reference compounds (IAA, PCIB). The responses of mutant plants to the reference compounds confirmed previous reports, but differed from the responses observed for parthenin. Parthenin stimulated and inhibited all mutants independent of resistance. This provided no indication for an auxin-related action of parthenin. Therefore, the hypothesis of an auxin-related inhibitory action of parthenin was rejected in two independent experimental approaches, while the hypothesis of an auxin-related stimulatory effect could not be rejected.

Measurement of Absolute Concentrations of Individual Compounds in Metabolite Mixtures by Gradient-Selective Time-Zero 1H-13C HSQC (gsHSQC0) with Two Concentration References and Fast Maximum Likelihood Reconstruction Analysis

PubMed Central

Hu, Kaifeng; Ellinger, James J.; Chylla, Roger A.; Markley, John L.

2011-01-01

Time-zero 2D 13C HSQC (HSQC0) spectroscopy offers advantages over traditional 2D NMR for quantitative analysis of solutions containing a mixture of compounds because the signal intensities are directly proportional to the concentrations of the constituents. The HSQC0 spectrum is derived from a series of spectra collected with increasing repetition times within the basic HSQC block by extrapolating the repetition time to zero. Here we present an alternative approach to data collection, gradient-selective time-zero 1H-13C HSQC0 in combination with fast maximum likelihood reconstruction (FMLR) data analysis and the use of two concentration references for absolute concentration determination. Gradient-selective data acquisition results in cleaner spectra, and NMR data can be acquired in both constant-time and non-constant time mode. Semi-automatic data analysis is supported by the FMLR approach, which is used to deconvolute the spectra and extract peak volumes. The peak volumes obtained from this analysis are converted to absolute concentrations by reference to the peak volumes of two internal reference compounds of known concentration: DSS (4,4-dimethyl-4-silapentane-1-sulfonic acid) at the low concentration limit (which also serves as chemical shift reference) and MES (2-(N-morpholino)ethanesulfonic acid) at the high concentration limit. The linear relationship between peak volumes and concentration is better defined with two references than with one, and the measured absolute concentrations of individual compounds in the mixture are more accurate. We compare results from semi-automated gsHSQC0 with those obtained by the original manual phase-cycled HSQC0 approach. The new approach is suitable for automatic metabolite profiling by simultaneous quantification of multiple metabolites in a complex mixture. PMID:22029275

Infrared Spectroscopy of Deuterated Compounds.

ERIC Educational Resources Information Center

MacCarthy, Patrick

1985-01-01

Background information, procedures used, and typical results obtained are provided for an experiment (based on the potassium bromide pressed-pellet method) involving the infrared spectroscopy of deuterated compounds. Deuteration refers to deuterium-hydrogen exchange at active hydrogen sites in the molecule. (JN)

Reference States and Relative Values of Internal Energy, Enthalpy, and Entropy.

ERIC Educational Resources Information Center

Fredrickson, A. G.

1983-01-01

Discusses two reference states (pure chemical compounds and pure elements at specified condition of temperature and pressure) and the relation between these reference states for internal energy and enthalpy. Problem 5.11 from Modell and Reid's "Thermodynamics and its Applications" (p. 141) is used to apply the ideas discussed. (JN)

Antioxidant activities of phenolic compounds isolated from the leaves of Macaranga allorobinsonii Whitmore

NASA Astrophysics Data System (ADS)

Darmawan, Akhmad; Fajriah, Sofa; Megawati, Dewijanti, Indah D.; Banjarnahor, Sofna; Yuliani, Tri; Hartati, Sri; Mozef, Tjandrawati; Effendi, Ruslan; Swandiny, Greesty F.

2017-01-01

Two secondary metabolites compounds, gallic acid (1) and methyl gallate (2) have been isolated from the ethyl acetate fraction of the methanol extract of the leaves of Macaranga allorobinsonii Whitmore. Isolation and purification of the secondary metabolite compounds conducted using chromatography methods, and structure elucidation determined based on NMR, mass spectroscopic data and compared with appropriate references.

MEASUREMENTS OF NON-METHANE VOLATILE ORGANIC COMPOUNDS IN THE LOWER TROPOSPHERE FROM TETHERED BALLOON AND KITE SAMPLING PLATFORMS BY INTERNAL STANDARD CALIBRATION USING AMBIENT CFC REFERENCE COMPOUNDS

EPA Science Inventory

A new analytical approach for the sampling and analysis of volatile organic compounds (VOCs) from sampling platforms used in the vertical profiling of the lower troposphere, such as kites, balloons, and remotely piloted vehicles will be developed. These sampling platforms a...

Carbon-11-Pittsburgh compound B positron emission tomography imaging of amyloid deposition in presenilin 1 mutation carriers.

PubMed

Knight, William D; Okello, Aren A; Ryan, Natalie S; Turkheimer, Federico E; Rodríguez Martinez de Llano, Sofia; Edison, Paul; Douglas, Jane; Fox, Nick C; Brooks, David J; Rossor, Martin N

2011-01-01

(11)Carbon-Pittsburgh compound B positron emission tomography studies have suggested early and prominent amyloid deposition in the striatum in presenilin 1 mutation carriers. This cross-sectional study examines the (11)Carbon-Pittsburgh compound B positron emission tomography imaging profiles of presymptomatic and mildly affected (mini-mental state examination ≥ 20) carriers of seven presenilin 1 mutations, comparing them with groups of controls and symptomatic sporadic Alzheimer's disease cases. Parametric ratio images representing (11)Carbon-Pittsburgh compound B retention from 60 to 90 min were created using the pons as a reference region and nine regions of interest were studied. We confirmed that increased amyloid load may be detected in presymptomatic presenilin 1 mutation carriers with (11)Carbon-Pittsburgh compound B positron emission tomography and that the pattern of retention is heterogeneous. Comparison of presenilin 1 and sporadic Alzheimer's disease groups revealed significantly greater thalamic retention in the presenilin 1 group and significantly greater frontotemporal retention in the sporadic Alzheimer's disease group. A few individuals with presenilin 1 mutations showed increased cerebellar (11)Carbon-Pittsburgh compound B retention suggesting that this region may not be as suitable a reference region in familial Alzheimer's disease.

Compounds of emerging concern in the San Antonio River Basin, Texas, 2011–12

USGS Publications Warehouse

Lambert, Rebecca B.; Opsahl, Stephen P.

2016-11-16

The City of San Antonio and the surrounding municipalities in Bexar County, Texas, are among the fastest growing cities in the Nation. Increases in residential and commercial development are changing runoff patterns and likely will increase chemical loads into streams. The U.S. Geological Survey, in cooperation with the San Antonio River Authority, evaluated the concentrations and distributional patterns of selected “compounds of emerging concern” (CECs) by collecting and analyzing water-quality samples from 20 sites in the San Antonio River Basin, Tex., during 2011–12. On the basis of their chemical composition or similar uses, the CECs discussed in this fact sheet are wastewater compounds, pharmaceutical compounds (hereinafter referred to as “pharmaceuticals”), and steroidal hormone and sterol compounds (hereinafter referred to as “steroidal hormones and sterols”). Three synoptic sampling events were completed during 2011–12 to analyze for CECs in the San Antonio River Basin. Samples were analyzed for 54 wastewater compounds, 13 pharmaceuticals, 17 steroidal hormones, and 4 sterols. Overall, the concentrations of all CECs analyzed for during this study were low, generally close to or less than the laboratory reporting level.

Tyrosinase inhibitor activity of coumarin-resveratrol hybrids.

PubMed

Fais, Antonella; Corda, Marcella; Era, Benedetta; Fadda, M Benedetta; Matos, Maria Joao; Quezada, Elias; Santana, Lourdes; Picciau, Carmen; Podda, Gianni; Delogu, Giovanna

2009-07-13

In the present work we report on the contribution of the coumarin moiety to tyrosinase inhibition. Coumarin-resveratrol hybrids 1-8 have been resynthesized to investigate the structure-activity relationships and the IC(50) values of these compounds were measured. The results showed that these compounds exhibited tyrosinase inhibitory activity. Compound 3-(3',4',5'-trihydroxyphenyl)-6,8-dihydroxycoumarin (8)is the most potentcompound (0.27 mM), more so than umbelliferone (0.42 mM), used as reference compound. The kinetic studies revealed that compound 8 caused non-competitive tyrosinase inhibition.

78 FR 46141 - Approval and Disapproval of Air Quality State Implementation Plans; Arizona; Regional Haze and...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-07-30

... volatile organic compounds. (42) The initials WRAP mean or refer to the Western Regional Air Partnership... sources of NO X, SO 2 or volatile organic compounds (VOCs) or on point sources [[Page 46144

Synthesis of monomethyl 5,5'-dehydrodiferulic acid

USDA-ARS?s Scientific Manuscript database

Synthesis of the internal reference compound, monomethyl 5,5’-dehydrodiferulic acid, is described. The synthetic scheme relies on a selective monomethylation of the known compound 5,5-dehydrodivanillin, followed by elaboration into the dehydrodiferulic framework through a dual Horner-Emmons-Wadswort...

Reactions of aromatic diazonium salts with unsaturated compounds in the presence of nucleophiles

NASA Astrophysics Data System (ADS)

Grishchuk, B. D.; Gorbovoi, P. M.; Ganushchak, N. I.; Dombrovskii, A. V.

1994-03-01

The review surveys the reactions of aromatic diazonium salts with diene and monounsaturated compounds in the presence of nucleophiles. Certain further reactions of the reaction products and their application are considered. The bibliography includes 63 references.

River bottom sediment from the Vistula as matrix of candidate for a new reference material.

PubMed

Kiełbasa, Anna; Buszewski, Bogusław

2017-08-01

Bottom sediments are very important in aquatic ecosystems. The sediments accumulate heavy metals and compounds belonging to the group of persistent organic pollutants. The accelerated solvent extraction (ASE) was used for extraction of 16 compounds from PAH group from bottom sediment of Vistula. For the matrix of candidate of a new reference material, moisture content, particle size, loss on ignition, pH, and total organic carbon were determined. A gas chromatograph with a selective mass detector (GC/MS) was used for the final analysis. The obtained recoveries were from 86% (SD=6.9) for anthracene to 119% (SD=5.4) for dibenzo(ah)anthracene. For the candidate for a new reference material, homogeneity and analytes content were determined using a validated method. The results are a very important part of the development and certification of a new reference materials. Copyright © 2017 Elsevier Inc. All rights reserved.

Multi-edge X-ray absorption spectroscopy study of road dust samples from a traffic area of Venice using stoichiometric and environmental references

NASA Astrophysics Data System (ADS)

Valotto, Gabrio; Cattaruzza, Elti; Bardelli, Fabrizio

2017-02-01

The appropriate selection of representative pure compounds to be used as reference is a crucial step for successful analysis of X-ray absorption near edge spectroscopy (XANES) data, and it is often not a trivial task. This is particularly true when complex environmental matrices are investigated, being their elemental speciation a priori unknown. In this paper, an investigation on the speciation of Cu, Zn, and Sb based on the use of conventional (stoichiometric compounds) and non-conventional (environmental samples or relevant certified materials) references is explored. This method can be useful in when the effectiveness of XANES analysis is limited because of the difficulty in obtaining a set of references sufficiently representative of the investigated samples. Road dust samples collected along the bridge connecting Venice to the mainland were used to show the potentialities and the limits of this approach.

Synthesis, Biological Evaluation and Molecular Docking Study of Hydrazone-Containing Pyridinium Salts as Cholinesterase Inhibitors.

PubMed

Parlar, Sulunay; Bayraktar, Gulsah; Tarikogullari, Ayse Hande; Alptüzün, Vildan; Erciyas, Ercin

2016-01-01

A series of pyridinium salts bearing alkylphenyl groups at 1 position and hydrazone structure at 4 position of the pyridinium ring were synthesized and evaluated for the inhibition of both acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) enzymes. The cholinesterase (ChE) inhibitory activity studies were carried out by using the Ellman's colorimetric method. All compounds displayed considerable AChE and BuChE inhibitory activity and some of the compounds manifested remarkable anti-AChE activity compared to the reference compound, galantamine. Among the title compounds, the series including benzofuran aromatic ring exhibited the best inhibitory activity both on AChE and BuChE enzymes. Compound 3b, 4-[2-(1-(benzofuran-2-yl)ethylidene)hydrazinyl]-1-(3-phenylpropyl)pyridinium bromide, was the most active compound with IC50 value of 0.23 (0.24) µM against enantiomeric excess (ee)AChE (human (h)AChE) while compound 3a, 4-[2-(1-(benzofuran-2-yl)ethylidene)hydrazinyl]-1-phenethylpyridinium bromide, was the most active compound with IC50 value of 0.95 µM against BuChE. Moreover, 3a and b exhibited higher activity than the reference compound galantamine (eeAChE (hAChE) IC50 0.43 (0.52) µM; BuChE IC50 14.92 µM). Molecular docking studies were carried out on 3b having highest inhibitory activity against AChE.

Barium and Compounds

Integrated Risk Information System (IRIS)

EPA / 635 / R - 05 / 001 www.epa.gov / iris TOXICOLOGICAL REVIEW OF BARIUM AND COMPOUNDS ( CAS No . 7440 - 39 - 3 ) In Support of Summary Information on the Integrated Risk Information System ( IRIS ) March 1998 Minor revisions January 1999 Reference dose revised June 2005 U.S . Environmental Protec

The Chemiluminescence of Organometallic Compounds

NASA Astrophysics Data System (ADS)

Tolstikov, Genrikh A.; Bulgakov, Ramil G.; Kazakov, Valeri P.

1985-11-01

Studies on the liquid-phase and gas-phase reactions of organometallic compounds accompanied by the emission of light are described systematically and discussed. The influence of the magnetic field on the chemiluminescence of Grignard reagents and the study of the electrochemiluminescence of solutions of organometallic compounds are examined. The ways leading to further development of the field of the chemiluminescence of organometallic compounds and certain possible applications of the phenomenon in the monitoring of industrial processes are discussed. The bibliography includes 80 references.

Proposed Confidence Scale and ID Score in the Identification of Known-Unknown Compounds Using High Resolution MS Data

NASA Astrophysics Data System (ADS)

Rochat, Bertrand

2017-04-01

High-resolution (HR) MS instruments recording HR-full scan allow analysts to go further beyond pre-acquisition choices. Untargeted acquisition can reveal unexpected compounds or concentrations and can be performed for preliminary diagnosis attempt. Then, revealed compounds will have to be identified for interpretations. Whereas the need of reference standards is mandatory to confirm identification, the diverse information collected from HRMS allows identifying unknown compounds with relatively high degree of confidence without reference standards injected in the same analytical sequence. However, there is a necessity to evaluate the degree of confidence in putative identifications, possibly before further targeted analyses. This is why a confidence scale and a score in the identification of (non-peptidic) known-unknown, defined as compounds with entries in database, is proposed for (LC-) HRMS data. The scale is based on two representative documents edited by the European Commission (2007/657/EC) and the Metabolomics Standard Initiative (MSI), in an attempt to build a bridge between the communities of metabolomics and screening labs. With this confidence scale, an identification (ID) score is determined as [a number, a letter, and a number] (e.g., 2D3), from the following three criteria: I, a General Identification Category (1, confirmed, 2, putatively identified, 3, annotated compounds/classes, and 4, unknown); II, a Chromatography Class based on the relative retention time (from the narrowest tolerance, A, to no chromatographic references, D); and III, an Identification Point Level (1, very high, 2, high, and 3, normal level) based on the number of identification points collected. Three putative identification examples of known-unknown will be presented.

[Written pharmaceutical advertising--still unreliable?].

PubMed

Gladsø, Kristin Haugen; Garberg, Hedda Rosland; Spigset, Olav; Slørdal, Lars

2014-09-02

Marketing by the pharmaceutical industry affects doctors' prescribing habits. All pharmaceutical advertising received by nine doctors in two GP offices over a period of three months was collected. The advertising material was sorted by compound. For each compound, the advert with the highest number of references was selected. The cited references were obtained, and the claims in the adverts were assessed in terms of their consistency with the source data based on the provisions in the Norwegian regulations on pharmaceuticals. The references were also assessed with regard to the incidence of conflicts of interest among authors. The doctors received a total of 270 shipments of advertising for 46 different compounds. Altogether 95% of the 173 references cited in the 46 selected adverts could be obtained. The adverts contained a total of 156 claims. Of these, 56% were assessed as correct when compared to the source data and as having clinical relevance. Altogether 75% of the journal articles reported relevant conflicts of interest for the authors. About half the claims in the adverts were found to be correct and clinically relevant. These results concur with those from a methodologically identical study based on advertising material collected in 2004. The cited literature was of varying quality and often funded by the pharmaceutical companies. The findings indicate that the target group should be sceptical of this type of marketing.

CSAHi study-2: Validation of multi-electrode array systems (MEA60/2100) for prediction of drug-induced proarrhythmia using human iPS cell-derived cardiomyocytes: Assessment of reference compounds and comparison with non-clinical studies and clinical information.

PubMed

Nozaki, Yumiko; Honda, Yayoi; Watanabe, Hitoshi; Saiki, Shota; Koyabu, Kiyotaka; Itoh, Tetsuji; Nagasawa, Chiho; Nakamori, Chiaki; Nakayama, Chiaki; Iwasaki, Hiroshi; Suzuki, Shinobu; Tanaka, Kohji; Takahashi, Etsushi; Miyamoto, Kaori; Morimura, Kaoru; Yamanishi, Atsuhiro; Endo, Hiroko; Shinozaki, Junko; Nogawa, Hisashi; Shinozawa, Tadahiro; Saito, Fumiyo; Kunimatsu, Takeshi

2017-08-01

With the aim of reconsidering ICH S7B and E14 guidelines, a new in vitro assay system has been subjected to worldwide validation to establish a better prediction platform for potential drug-induced QT prolongation and the consequent TdP in clinical practice. In Japan, CSAHi HEART team has been working on hiPS-CMs in the MEA (hiPS-CMs/MEA) under a standardized protocol and found no inter-facility or lot-to-lot variability for proarrhythmic risk assessment of 7 reference compounds. In this study, we evaluated the responses of hiPS-CMs/MEA to another 31 reference compounds associated with cardiac toxicities, and gene expression to further clarify the electrophysiological characteristics over the course of culture period. The hiPS-CMs/MEA assay accurately predicted reference compounds potential for arrhythmogenesis, and yielded results that showed better correlation with target concentrations of QTc prolongation or TdP in clinical setting than other current in vitro and in vivo assays. Gene expression analyses revealed consistent profiles in all samples within and among the testing facilities. This report would provide CiPA with informative guidance on the use of the hiPS-CMs/MEA assay, and promote the establishment of a new paradigm, beyond conventional in vitro and in vivo assays for cardiac safety assessment of new drugs. Copyright © 2017 Elsevier Inc. All rights reserved.

Screening for (anti)androgenic properties using a standard operation protocol based on the human stably transfected androgen sensitive PALM cell line. First steps towards validation.

PubMed

Freyberger, A; Witters, H; Weimer, M; Lofink, W; Berckmans, P; Ahr, H-J

2010-08-01

Despite more than a decade of research in the field of endocrine active compounds targeting the androgen receptor (AR), and although suitable cell lines can be obtained, no validated human stably transfected androgen sensitive transactivation assay is available. Bayer Schering Pharma (BSP) and the Flemish Institute for Technological Research (VITO), partners within the EU-sponsored 6th framework project ReProTect, made first steps towards such a validation. A standard operation protocol (SOP) developed at BSP based on the androgen sensitive PALM cell line was transferred to VITO and its performance and transferability were thoroughly studied. The investigation followed a generic protocol prepared for all reporter gene assays evaluated within ReProTect, and in both laboratories at least three independent experiments were performed. The highest concentration to be tested was limited to 10 microM, if needed. A few compounds, 17alpha-methyltestosterone (17alpha-MT), vinclozolin and linuron, were studied using a real world scenario, i.e., assuming that their interaction with the AR was not known: A prescreening for agonism and true, competitive antagonism was used to select conditions such as the appropriate mode of action, and the working range excluding cytotoxicity for the final screening. All other compounds were tested according to the generic protocol: Compounds screened for agonism were the reference androgen 17alpha-methyldihydrotestosterone (MDHT), levonorgestrel, norethynodrel, progesterone, o,p'-DDT, and dibutylphthalate (DBP), while compounds screened for antagonism were the reference anti-androgen flutamide, prochloraz, o,p'-DDT, progesterone, norethynodrel, and DBP. Cytotoxicity was assessed in parallel as lactate dehydrogenase release. The prescreen classified 17alpha-MT as androgenic, vinclozolin and linuron as anti-androgenic and compounds were tested accordingly. In the absence of cytotoxicity, appropriate androgenic properties of reference and test compounds were detected by both laboratories, o,p'-DDT and DBP had no androgenic activity. Across the two laboratories EC(50)-values for MDHT, 17alpha-MT, and levonorgestrel varied by not more than a factor of 3.4, for norethynodrel by a factor of 9.7. Progesterone effects could not fully be evaluated, as frequently concentration response curves were incomplete. In the absence of cytotoxicity anti-androgenic properties of reference and test compounds were also detected in both laboratories. DBP, the putative negative reference compound, was inactive, norethynodrel rather showed agonistic properties. Progesterone was an antagonist at low concentrations, but agonistic properties were observed in one laboratory at high concentrations. Since the highest test concentration was limited to 10 microM, for some compounds no complete concentration response curves were obtained and estimation of EC(50)-values was less robust. Our data demonstrated that the SOP was transferable, and that the assay was able to rank compounds with strong, weak, and without affinity for the AR and to discriminate agonists and antagonists. The sensitivity of the assay could be improved further, if the limit of solubility or beginning cytotoxicity was chosen as the highest test concentration. The assay avoids the use of tissues from laboratory animals, and thus contributes to the 3R concept. Furthermore, it could be adjusted to an intermediate/high throughput format. On the whole, this PALM assay is a promising candidate for further validation. Copyright 2009 Elsevier Inc. All rights reserved.

MICROWAVE-ASSISTED EXTRACTION OF ORGANIC COMPOUNDS FROM STANDARD REFERENCE SOILS AND SEDIMENTS

EPA Science Inventory

As part of an ongoing evaluation of new sample preparation techniques by the U.S. Environmental Protection Agency (EPA), especially those that minimize waste solvents, microwave-assisted extraction (MAE) of organic compounds from solid materials (or "matrices") was evaluated. Six...

MODEL DEVELOPMENT AND TESTING FOR SEMI-VOLATILES (ATRAZINE)

EPA Science Inventory

The Community Multi-Scale Air Quality (CMAQ) model, air quality model within EPA's Models-3 system, can be adapted to simulate the fate of semi-volatile compounds that are emitted into the atmosphere. "Semi-volatile" refers to compounds that partition their mass between two ph...

Design, synthesis and antibacterial activity of cinnamaldehyde derivatives as inhibitors of the bacterial cell division protein FtsZ.

PubMed

Li, Xin; Sheng, Juzheng; Huang, Guihua; Ma, Ruixin; Yin, Fengxin; Song, Di; Zhao, Can; Ma, Shutao

2015-06-05

In an attempt to discover potential antibacterial agents against the increasing bacterial resistance, novel cinnamaldehyde derivatives as FtsZ inhibitors were designed, synthesized and evaluated for their antibacterial activity against nine significant pathogens using broth microdilution method, and their cell division inhibitory activity against four representative strains. In the in vitro antibacterial activity, the newly synthesized compounds generally displayed better efficacy against Staphylococcus aureus ATCC25923 than the others. In particular, compounds 3, 8 and 10 exerted superior or comparable activity to all the reference drugs. In the cell division inhibitory activity, all the compounds showed the same trend as their in vitro antibacterial activity, exhibiting better activity against S. aureus ATCC25923 than the other strains. Additionally, compounds 3, 6, 7 and 8 displayed potent cell division inhibitory activity with an MIC value of below 1 μg/mL, over 256-fold better than all the reference drugs. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

Photochemical transformations of diazocarbonyl compounds: expected and novel reactions

NASA Astrophysics Data System (ADS)

Galkina, O. S.; Rodina, L. L.

2016-05-01

Photochemical reactions of diazocarbonyl compounds are well positioned in synthetic practice as an efficient method for ring contraction and homologation of carboxylic acids and as a carbene generation method. However, interpretation of the observed transformations of diazo compounds in electronically excited states is incomplete and requires a careful study of the fine mechanisms of these processes specific to different excited states of diazo compounds resorting to modern methods of investigation, including laser technology. The review is devoted to analysis of new data in the chemistry of excited states of diazocarbonyl compounds. The bibliography includes 155 references.

Bibliography of Work on the Heterogeneous Photocatalytic Removal of Hazardous Compounds from Water and Air--Update Number 4 to October 2001

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

Blake, D.

2001-11-19

This report is the fifth in a series of bibliographies of work on the photocatalytic oxidation of organic or inorganic compounds in air or water and on the photocatalytic reduction of inorganic compounds in water. This search contains information extracted from 1149 new references to papers, books, and reports from searches conducted between October 1996 and April 2001.

Solid-phase cadmium speciation in soil using L3-edge XANES spectroscopy with partial least-squares regression.

PubMed

Siebers, Nina; Kruse, Jens; Eckhardt, Kai-Uwe; Hu, Yongfeng; Leinweber, Peter

2012-07-01

Cadmium (Cd) has a high toxicity and resolving its speciation in soil is challenging but essential for estimating the environmental risk. In this study partial least-square (PLS) regression was tested for its capability to deconvolute Cd L(3)-edge X-ray absorption near-edge structure (XANES) spectra of multi-compound mixtures. For this, a library of Cd reference compound spectra and a spectrum of a soil sample were acquired. A good coefficient of determination (R(2)) of Cd compounds in mixtures was obtained for the PLS model using binary and ternary mixtures of various Cd reference compounds proving the validity of this approach. In order to describe complex systems like soil, multi-compound mixtures of a variety of Cd compounds must be included in the PLS model. The obtained PLS regression model was then applied to a highly Cd-contaminated soil revealing Cd(3)(PO(4))(2) (36.1%), Cd(NO(3))(2)·4H(2)O (24.5%), Cd(OH)(2) (21.7%), CdCO(3) (17.1%) and CdCl(2) (0.4%). These preliminary results proved that PLS regression is a promising approach for a direct determination of Cd speciation in the solid phase of a soil sample.

40 CFR 59.412 - Incorporations by reference.

Code of Federal Regulations, 2010 CFR

2010-07-01

... address: American Society for Testing and Materials (ASTM), 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959. (1) ASTM Method C 1315-95, Standard Specification for Liquid Membrane-Forming Compounds....401, Concrete curing and sealing compound. (2) ASTM Method D 523-89, Standard Test Method for Specular...

LITERATURE REVIEW OF PERSONAL AIR MONITORS FOR POTENTIAL USE IN AMBIENT AIR MONITORING OF ORGANIC COMPOUNDS

EPA Science Inventory

The open literature, Federal publications, industrial reports, and other sources published between 1975 and 1980 were reviewed for information relevant to personal air samplers potentially useful in sampling organic compounds at ambient levels (50-200 ppt). Seventy one references...

Pain: Systematic Review of Pharmacy Compounding of Pain Medication.

PubMed

Shawaqfeh, Mohammad S; Harrington, Catherine

2018-01-01

There are limited resources available for pharmacists and doctors to reference proper compounded formulas for pain medications. The systematic review discussed within this article provides the foundation for a searchable database, allowing users to find various compounded formulations. It also provides data about the safety and efficacy of the preparations. Compounding information about several drug classes was reviewed. Those drug classes included, but were not limited to, opioids, non-steroidal anti-inflammatory drugs, central nervous system agents, and anesthetics, with evidence that of the various drugs that could be compounded for pain, anesthetics, non-steroidal anti-inflammatory drugs, and opioids ranked highest within the articles researched. Copyright© by International Journal of Pharmaceutical Compounding, Inc.

Synthesis and biological evaluation of pyrazolylthiazole carboxylic acids as potent anti-inflammatory-antimicrobial agents.

PubMed

Khloya, Poonam; Kumar, Satish; Kaushik, Pawan; Surain, Parveen; Kaushik, Dhirender; Sharma, Pawan K

2015-03-15

Current Letter presents design, synthesis and biological evaluation of a novel series of pyrazolylthiazole carboxylates 1a-1p and corresponding acid derivatives 2a-2p. All 32 novel compounds were tested for their in vivo anti-inflammatory activity by carrageenan-induced rat paw edema method as well as for in vitro antimicrobial activity. All the tested compounds exhibited excellent AI activity profile. Three compounds 1p (R=Cl, R(1)=Cl), 2c (R=H, R(1)=F) and 2n (R=Cl, R(1)=OCH3) were identified as potent anti-inflammatory agents exhibiting edema inhibition of 93.06-89.59% which is comparable to the reference drug indomethacin (91.32%) after 3h of carrageenan injection while most of the other compounds displayed inhibition ⩾80%. In addition, pyrazolylthiazole carboxylic acids (2a-2p) also showed good antimicrobial profile. Compound 2h (R=OCH3, R(1)=Cl) showed excellent antimicrobial activity (MIC 6.25μg/mL) against both Gram positive bacteria comparable with the reference drug ciprofloxacin (MIC 6.25μg/mL). Copyright © 2015 Elsevier Ltd. All rights reserved.

40 CFR 63.2354 - What performance tests, design evaluations, and performance evaluations must I conduct?

Code of Federal Regulations, 2011 CFR

2011-07-01

... of Gaseous Organic Compounds by Direct Interface Gas Chromatography-Mass Spectrometry (incorporated... Method for Determination of Gaseous Organic Compounds by Direct Interface Gas Chromatography-Mass... Interface Gas Chromatography-Mass Spectrometry (incorporated by reference, see § 63.14),; or (B) For target...

USE OF BIOASSAY-DIRECTED CHEMICAL ANALYSIS FOR IDENTIFYING MUTAGENIC COMPOUNDS IN URBAN AIR AND COMBUSTION EMISSIONS

EPA Science Inventory

Bioassay-directed chemical analysis fractionation has been used for 30 years to identify mutagenic classes of compounds in complex mixtures. Most studies have used the Salmonella (Ames) mutagenicity assay, and we have recently applied this methodology to two standard reference sa...

EFFECTS OF BENZO[A]PYRENE EXPOSURE ON A FISH POPULATION RESISTANT TO THE TOXIC EFFECTS OF DIOXIN-LIKE COMPOUNDS

EPA Science Inventory

Effects of a model polycyclic aromatic hydrocarbon (PAH) were compared in populations of the estuarine fish Fundulus heteroclitus indigenous to a reference site and one highly contaminated with polychlorinated biphenyls (PCBs) and other compounds. The fish population resident to ...

Synthesis and biological evaluation of Fotemustine analogues on human melanoma cell lines.

PubMed

Winum, Jean Yves; Bouissière, Jean Luc; Passagne, Isabelle; Evrard, Alexandre; Montero, Véronique; Cuq, Pierre; Montero, Jean Louis

2003-03-01

Two new analogues of Fotemustine have been synthesized and tested on two melanoma cell lines. Compounds 4 and 8 proved to be more potent than the reference compound on A375 cell line which express the MGMT enzyme involved in the chemoresistance of tumoral cells.

Derivatives of diphosphonic acids: synthesis and biological activity

NASA Astrophysics Data System (ADS)

Zolotukhina, M. M.; Krutikov, V. I.; Lavrent'ev, A. N.

1993-07-01

The scientific-technical and patent literature on the synthesis of derivatives of diphosphonic acids is surveyed. Various methods of synthesis of diphosphonate, phosphonylphosphinyl, and phosphonophosphate compounds are described. The principal aspects of the use of the above compounds in medicine, biochemistry, and agriculture are examined. The bibliography includes 174 references.

AN ENZYME-LINKED IMMUNOSORBENT ASSAY (ELISA) FOR DETERMINING DIOXINS IN SEDIMENT AND SOIL SAMPLES

EPA Science Inventory

The dioxins comprise a family of compounds chemically referred to as polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs). The most toxic of these compounds is 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), a known human carcinogen. Dioxins are formed ...

Exposure and effects of perfluoroalkyl compounds on tree swallows nesting at Lake Johanna in east central Minnesota, USA

USGS Publications Warehouse

Custer, Christine M.; Custer, Thomas W.; Schoenfuss, Heiko L.; Poganski, Beth H.; Solem, Laura

2012-01-01

Tree swallow (Tachycineta bicolor) samples were collected at a reference lake and a nearby lake (Lake Johanna) in east central Minnesota, USA contaminated with perfluorinated carboxylic and sulfonic acids. Tissues were analyzed for a suite of 13 perfluoroalkyl compounds (PFCs) to quantify exposure and to determine if there was an association between egg concentrations of PFCs and reproductive success of tree swallows. Concentrations of perfluoroocatane sulfonate (PFOS) were elevated in all tree swallow tissues from Lake Johanna compared to tissues collected at the reference lake. Other PFCs, except for two, were elevated in blood plasma at Lake Johanna compared to the reference lake. PFOS was the dominant PFC (>75%) at Lake Johanna, but accounted for <50% of total PFCs at the reference lake. There was a negative association between concentrations of PFOS in eggs and hatching success. Reduced hatching success was associated with PFOS levels as low as 150 ng/g wet weight.

Multi-edge X-ray absorption spectroscopy study of road dust samples from a traffic area of Venice using stoichiometric and environmental references.

PubMed

Valotto, Gabrio; Cattaruzza, Elti; Bardelli, Fabrizio

2017-02-15

The appropriate selection of representative pure compounds to be used as reference is a crucial step for successful analysis of X-ray absorption near edge spectroscopy (XANES) data, and it is often not a trivial task. This is particularly true when complex environmental matrices are investigated, being their elemental speciation a priori unknown. In this paper, an investigation on the speciation of Cu, Zn, and Sb based on the use of conventional (stoichiometric compounds) and non-conventional (environmental samples or relevant certified materials) references is explored. This method can be useful in when the effectiveness of XANES analysis is limited because of the difficulty in obtaining a set of references sufficiently representative of the investigated samples. Road dust samples collected along the bridge connecting Venice to the mainland were used to show the potentialities and the limits of this approach. Copyright © 2016 Elsevier B.V. All rights reserved.

Bibliography of work on the heterogeneous photocatalytic removal of hazardous compounds from water and air, Update Number 2 to October 1996

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

Blake, D.M.

1997-01-01

The Solar Industrial Program has developed processes that destroy hazardous substances in or remove them from water and air. The processes of interest in this report are based on the application of heterogeneous photocatalysts, principally titanium dioxide or modifications thereof, but work on other heterogeneous catalysts is included in this compilation. This report continues bibliographies that were published in May, 1994, and October, 1995. The previous reports included 663 and 574 citations, respectively. This update contains an additional 518 references. These were published during the period from June 1995 to October 1996, or are references from prior years that weremore » not included in the previous reports. The work generally focuses on removing hazardous contaminants from air or water to meet environmental or health regulations. This report also references work on properties of semiconductor photocatalysts and applications of photocatalytic chemistry in organic synthesis. This report follows the same organization as the previous publications. The first part provides citations for work done in a few broad categories that are generic to the process. Three tables provide references to work on specific substances. The first table lists organic compounds that are included in various lists of hazardous substances identified by the US Environmental Protection Agency (EPA). The second table lists compounds not included in those categories, but which have been treated in a photocatalytic process. The third table covers inorganic compounds that are on EPA lists of hazardous materials or that have been treated by a photocatalytic process. A short update on companies that are active in providing products or services based on photocatalytic processes is provided.« less

Applying Tandem Mass Spectral Libraries for Solving the Critical Assessment of Small Molecule Identification (CASMI) LC/MS Challenge 2012

PubMed Central

Oberacher, Herbert

2013-01-01

The “Critical Assessment of Small Molecule Identification” (CASMI) contest was aimed in testing strategies for small molecule identification that are currently available in the experimental and computational mass spectrometry community. We have applied tandem mass spectral library search to solve Category 2 of the CASMI Challenge 2012 (best identification for high resolution LC/MS data). More than 230,000 tandem mass spectra part of four well established libraries (MassBank, the collection of tandem mass spectra of the “NIST/NIH/EPA Mass Spectral Library 2012”, METLIN, and the ‘Wiley Registry of Tandem Mass Spectral Data, MSforID’) were searched. The sample spectra acquired in positive ion mode were processed. Seven out of 12 challenges did not produce putative positive matches, simply because reference spectra were not available for the compounds searched. This suggests that to some extent the limited coverage of chemical space with high-quality reference spectra is still a problem encountered in tandem mass spectral library search. Solutions were submitted for five challenges. Three compounds were correctly identified (kanamycin A, benzyldiphenylphosphine oxide, and 1-isopropyl-5-methyl-1H-indole-2,3-dione). In the absence of any reference spectrum, a false positive identification was obtained for 1-aminoanthraquinone by matching the corresponding sample spectrum to the structurally related compounds N-phenylphthalimide and 2-aminoanthraquinone. Another false positive result was submitted for 1H-benz[g]indole; for the 1H-benz[g]indole-specific sample spectra provided, carbazole was listed as the best matching compound. In this case, the quality of the available 1H-benz[g]indole-specific reference spectra was found to hamper unequivocal identification. PMID:24957994

Bibliography of work on the photocatalytic removal of hazardous compounds from water and air

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

Blake, D.M.

1994-05-01

This is a bibliography of information in the open literature on work that has been done to date on the photocatalytic oxidation of compounds, principally organic compounds. The goal of the listing is removing hazardous oompounds from water or air. It contains lists of substances and literature citations. The bibliography includes information obtained through the middle of 1993 and some selected references for the balance of that year.

Synthetic Aziridines in Medicinal Chemistry: A Mini-Review.

PubMed

Singh, Girija S

2016-01-01

Azaheterocyclic compounds are well-known to have diverse types of biological activity. Among them, azacyclopropanes, commonly referred as aziridines, occupy a prominent place in synthetic organic and medicinal chemistry due to its occurrence in natural resources, complexity involved in synthesis due to ring-strain, building blocks in organic synthesis, and its biological properties. Several novel compounds containing aziridine ring have been designed and synthesized recently by medicinal chemists for evaluating their biological profile. A number of compounds are reported as cysteine protease inhibitors, antibacterial, antifungal, anticancer, antileishmanial, and antimalarial agents. This review article summarizes the biological activity of such compounds. The preparation of such compounds is also described.

Crumbs regulates rhodopsin transport by interacting with and stabilizing myosin V

PubMed Central

Shevchenko, Anna

2011-01-01

The evolutionarily conserved Crumbs (Crb) complex is crucial for photoreceptor morphogenesis and homeostasis. Loss of Crb results in light-dependent retinal degeneration, which is prevented by feeding mutant flies carotenoid-deficient medium. This suggests a defect in rhodopsin 1 (Rh1) processing, transport, and/or signaling, causing degeneration; however, the molecular mechanism of this remained elusive. In this paper, we show that myosin V (MyoV) coimmunoprecipitated with the Crb complex and that loss of crb led to severe reduction in MyoV levels, which could be rescued by proteasomal inhibition. Loss of MyoV in crb mutant photoreceptors was accompanied by defective transport of the MyoV cargo Rh1 to the light-sensing organelle, the rhabdomere. This resulted in an age-dependent accumulation of Rh1 in the photoreceptor cell (PRC) body, a well-documented trigger of degeneration. We conclude that Crb protects against degeneration by interacting with and stabilizing MyoV, thereby ensuring correct Rh1 trafficking. Our data provide, for the first time, a molecular mechanism for the light-dependent degeneration of PRCs observed in crb mutant retinas. PMID:22105348

LHP1 Regulates H3K27me3 Spreading and Shapes the Three-Dimensional Conformation of the Arabidopsis Genome

PubMed Central

Ariel, Federico; Latrasse, David; Mariappan, Kiruthiga Gayathri; Kim, Soon-Kap; Crespi, Martin; Hirt, Heribert; Bergounioux, Catherine; Raynaud, Cécile; Benhamed, Moussa

2016-01-01

Precise expression patterns of genes in time and space are essential for proper development of multicellular organisms. Dynamic chromatin conformation and spatial organization of the genome constitute a major step in this regulation to modulate developmental outputs. Polycomb repressive complexes (PRCs) mediate stable or flexible gene repression in response to internal and environmental cues. In Arabidopsis thaliana, LHP1 co-localizes with H3K27me3 epigenetic marks throughout the genome and interacts with PRC1 and PRC2 members as well as with a long noncoding RNA. Here, we show that LHP1 is responsible for the spreading of H3K27me3 towards the 3’ end of the gene body. We also identified a subset of LHP1-activated genes and demonstrated that LHP1 shapes local chromatin topology in order to control transcriptional co-regulation. Our work reveals a general role of LHP1 from local to higher conformation levels of chromatin configuration to determine its accessibility to define gene expression patterns. PMID:27410265

Confined Space Evaluation Student Manual, #19613

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

Chochoms, Michael

Many workplaces contain spaces that are considered to be “confined” because their configuration hinders the activities of employees who must enter into, work in, and exit from them. In general, the permit-required confined spaces (PRCSs) Occupational Safety and Health Administration (OSHA) standard requires that Los Alamos National Laboratory (LANL) evaluate the workplace to determine if any spaces are PRCSs. The standard specifies strict procedures for the evaluation and atmospheric testing of a space before and during an entry by workers. The OSHA PRCS standard provides for alternative (less stringent than full-permit) entry procedures in cases where the only hazard inmore » a space is atmospheric and the hazard can be controlled by forced air. At LANL, all confined spaces or potential confined spaces on LANL-owned or -operated property must be identified and evaluated by a confined space evaluator accompanied by a knowledgeable person. This course provides the information needed by confined space evaluators to make judgements about whether a space is a confined space, and if so, whether the space will require a permit for entry.« less

IRIS Toxicological Review of Vanadium Pentoxide (External Review Draft)

EPA Science Inventory

This vanadium pentoxide reassessment consists of an oral reference dose (RfD), an inhalation reference concentration (RfC), an inhalation unit risk (IUR) and a cancer weight of evidence descriptor. This is the first assessment developing an RfC or IUR for this compound. This as...

REFERENCE MATERIALS AND QUALITY ASSURANCE FOR THE CHARACTERIZATION OF ORGANIC COMPOUNDS IN PARTICULATE MATTER

EPA Science Inventory

One of the first environmental matrix Standard Reference Materials (SRMs) developed by the National Institute of Standards and Technology (NIST) for determination of organic species was SRM 1649 Urban Dust, ambient total suspended particulate matter (PM) collected in Washington D...

Design, synthesis and biological evaluation of novel ring-opened cromakalim analogues with relaxant effects on vascular and respiratory smooth muscles and as stimulators of elastin synthesis.

PubMed

Bouhedja, Mourad; Peres, Basile; Fhayli, Wassim; Ghandour, Zeinab; Boumendjel, Ahcène; Faury, Gilles; Khelili, Smail

2018-01-20

Two new series of ring-opened analogues of cromakalim bearing sulfonylurea moieties (series A: with N-unmethylated sulfonylureas, series B: with N-methylated sulfonylureas) were synthesized and tested as relaxants of vascular and respiratory smooth muscles (rat aorta and trachea, respectively). Ex vivo biological evaluations indicated that the most active compounds, belonging to series B, displayed a marked vasorelaxant activity on endothelium-intact aortic rings and the trachea. A majority of series B compounds exhibited a higher vasorelaxant activity (EC 50  < 22 μM) than that of the reference compound diazoxide (EC 50  = 24 μM). Interestingly, several tested compounds of series B also presented stronger relaxant effects on the trachea than the reference compound cromakalim (EC 50  = 124 μM), in particular compounds B4, B7 and B16 (EC 50  < 10 μM). By contrast, series A derivatives were poorly active on aortic rings (EC 50  > 57 μM for all, and EC 50  > 200 μM for a majority of them), but some of them showed an interesting relaxing effect on trachea (i.e. A15 and A33, EC 50  = 30 μM). The most potent compounds of both series, i.e. A15, A33 and B16, tested on aortic rings in the presence of glibenclamide or 80 mM KCl, suggested that they acted as voltage-gated Ca 2+ channel blockers, like verapamil, instead of being ATP-potassium channel activators, as is cromakalim, the parent molecule. Further investigations on cultured vascular smooth muscle cells showed a strong stimulating effect on elastin synthesis, especially compound B16, which was more active at 20 μM than diazoxide, a reference ATP-sensitive potassium channel activator. Taken together, our results show that the N-methylation of the sulfonylurea moieties of ring-opened cromakalim analogues led to new compounds blocking calcium-gated channels, which had a major impact on the arterial and tracheal activities as well as selectivity. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Computational mass spectrometry for small molecules

PubMed Central

2013-01-01

The identification of small molecules from mass spectrometry (MS) data remains a major challenge in the interpretation of MS data. This review covers the computational aspects of identifying small molecules, from the identification of a compound searching a reference spectral library, to the structural elucidation of unknowns. In detail, we describe the basic principles and pitfalls of searching mass spectral reference libraries. Determining the molecular formula of the compound can serve as a basis for subsequent structural elucidation; consequently, we cover different methods for molecular formula identification, focussing on isotope pattern analysis. We then discuss automated methods to deal with mass spectra of compounds that are not present in spectral libraries, and provide an insight into de novo analysis of fragmentation spectra using fragmentation trees. In addition, this review shortly covers the reconstruction of metabolic networks using MS data. Finally, we list available software for different steps of the analysis pipeline. PMID:23453222

Leishmanicidal activity of nine novel flavonoids from Delphinium staphisagria.

PubMed

Ramírez-Macías, Inmaculada; Marín, Clotilde; Díaz, Jesús G; Rosales, María José; Gutiérrez-Sánchez, Ramón; Sánchez-Moreno, Manuel

2012-01-01

To evaluate the in vitro leishmanicidal activity of nine flavonoid derivatives from Delphinium staphisagria against L. infantum and L. braziliensis. The in vitro activity of compounds 1-9 was assayed on extracellular promastigote and axenic amastigote forms and on intracellular amastigote forms of the parasites. Infectivity and cytotoxicity tests were carried on J774.2 macrophage cells using Glucantime as the reference drug. The mechanisms of action were analysed performing metabolite excretion and transmission electronic microscope ultrastructural alteration studies. Nine flavonoids showed leishmanicidal activity against promastigote as well as amastigote forms of Leishmania infantum and L. braziliensis. These compounds were nontoxic to mammalian cells and were effective at similar concentrations up to or lower than that of the reference drug (Glucantime). The results showed that 2(″)-acetylpetiolaroside (compound 8) was clearly the most active. This study has demonstrated that flavonoid derivatives are active against L. infantum and L. braziliensis.

Optimized structure and thermochemical properties of flavonoids determined by the CHIH(medium) DFT model chemistry versus experimental techniques

NASA Astrophysics Data System (ADS)

Mendoza-Wilson, Ana María.; Lardizabal-Gutiérrez, Daniel; Torres-Moye, Enrique; Fuentes-Cobas, Luis; Balandrán-Quintana, René R.; Camacho-Dávila, Alejandro; Quintero-Ramos, Armando; Glossman-Mitnik, Daniel

2007-12-01

The purpose of this work was to evaluate the accuracy of the CHIH(medium)-DFT model chemistry (PBEg/CBSB2 ∗∗//PBEg/CBSB4) in the determination of the optimized structure and thermochemical properties of heterocyclic systems of medium size such as flavonoids, wherefore were selected three of the most abundant flavonoids in vegetable tissues, and which posses the higher antioxidant activity: quercetin, (+)-catechin and cyanidin. As reference systems were employed three cyclic compounds: phenol, catechol and resorcinol. The thermochemical properties evaluated were enthalpy of formation, bond dissociation enthalpy (BDE) and ionization potential (IP), following the scheme of isodesmic reactions. The theoretical results were compared with experimental data generated by X-ray diffraction and calorimetric techniques realized in part by us, whereas other data were taken from the literature. The results obtained in this work reveal that the CHIH(medium)-DFT model chemistry represents an accurate computational tool to calculate structural and thermochemical properties in the studied flavonoid and reference compounds. The average absolute deviation of enthalpy of formation for reference compounds was 3.0 kcal/mol, 2.64 kcal/mol for BDE, and 2.97 kcal/mol for IP.

Quantitate gossypol enantiomers in cotton flower petals and seed using capillary electrophoresis

USDA-ARS?s Scientific Manuscript database

Gossypol is a compound that occurs in the cotton plant and in leaves it protects the plant from insect herbivory. The compound also occurs in the seed. In this tissue it renders the seed toxic to non-ruminant animals. However, gossypol exists as a mixture of enantiomers referred to as (+)-gossypo...

Use of integrated indoor concentrations of tracer gases and volatile organic compounds to distinguish soil sources from above-ground sources

EPA Science Inventory

Vapor intrusion refers to the situation in which harmful chemicals [such as halogenated or chlorinated volatile organic compounds (VOC) or petroleum products] in the groundwater or soil volatilize in the vadose zone and migrate into the indoor environment. These chemicals typical...

Chelation and effectiveness of salicylate related compounds on pyresis, sedimentation rate and hematocrit

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

Schubert, J.; Rosenthal, M.W.; Fried, J.F.

1984-01-01

The mechanism of action and identification of sites of salicylates and related compounds in antipyresis were studied. Structure-activity investigations of antipyresis were made using Sprague-Dawley rats. Results showed copper was chelated by the salicylate, passes through the cell membrane, and repairs the lesion. 13 references, 2 figures. (ACR)

SPECIATION OF NON-PESTICIDAL ORGANOTIN COMPOUNDS USING GAS CHROMATOGRAPHY WITH INDUCTIVELY COUPLED PLASMA-MASS SPECTROMETRY

EPA Science Inventory

Organotins can be classified into a broad class of compounds referred to as endocrine disruptors and are presently being used in many applications such as UV stabilizers in polyvinyl chloride (PVC) pipes, antifoulants in marine paints, and as fungicides to name a few. The organo...

CRITICAL EVALUATION OF THE DIFFUSION HYPOTHESIS IN THE THEORY OF POROUS MEDIA VOLATILE ORGANIC COMPOUND (VOC) SOURCES AND SINKS

EPA Science Inventory

The paper proposes three alternative, diffusion-limited mathematical models to account for volatile organic compound (VOC) interactions with indoor sinks, using the linear isotherm model as a reference point. (NOTE: Recent reports by both the U.S. EPA and a study committee of the...

CHARACTERIZATION OF FINE PARTICLE ASSOCIATED ORGANIC COMPOUNDS: INTERLABORATORY COMPARISON AND DEVELOPMENT OF STANDARD REFERENCE MATERIALS

EPA Science Inventory

Organic chemicals adsorbed to fine particulate matter (PM) in the ambient air account for a major component of the mass and include source tracers as well as toxic compounds that may contribute to adverse human health effects. The US EPA has established a PM 2.5 research progr...

An Investigation of Alternate Synthesis for 2,2’ -BIS(Phenylethynyl)-5, 5’ -Diaminobenzidine

DTIC Science & Technology

1985-05-01

essentially complete reaction of starting material to give cleanly the biphenyl tetraacetamide compound VIla. After work-up, the product melting point ...of compound llh in ethanolic potassium hydroxide with and without diethanolamine catalysis iReference 34) gave a product with a high melting point ...After cooling, aqueous work-up gave a precipitate, which after drying, displayed a low melting point (110-130 0 C). The crude compound was purified by

Structure-activity relationship of ortho- and meta-phenol based LFA-1 ICAM inhibitors.

PubMed

Lin, Edward Yin-Shiang; Guckian, Kevin M; Silvian, Laura; Chin, Donovan; Boriack-Sjodin, P Ann; van Vlijmen, Herman; Friedman, Jessica E; Scott, Daniel M

2008-10-01

LFA-1 ICAM inhibitors based on ortho- and meta-phenol templates were designed and synthesized by Mitsunobu chemistry. The selection of targets was guided by X-ray co-crystal data, and led to compounds which showed an up to 30-fold increase in potency over reference compound 1 in the LFA-1/ICAM1-Ig assay. The most active compound exploited a new hydrogen bond to the I-domain and exhibited subnanomolar potency.

Laser Eye Protection Groupware Application Information System

DTIC Science & Technology

1998-11-01

Q^ Concenlralion ^ Data & Program Res ■>i Excfted Stele Cross-Section ’^> EKtrnction Coefficient ^s Ground Stale Cross-Section ?> Reference...2nd Level (2nd column) 4 Chemical Compound Bio material name 3nd Level (3rd column) 4th Level (4th column) Figure 14A. Reference Date View

Contaminated sediments from tributaries of the Great Lakes: Chemical characterization and carcinogenic effects in medaka (Oryzias latipes)

USGS Publications Warehouse

Besser, John M.; Schmitt, Christopher J.; Harshbarger, John C.; Peterman, Paul H.; Lebo, Jon A.

1991-01-01

Sediments from four inshore industrial sites and a reference site in the Great Lakes were extracted with organic solvents to produce a crude extract, which was separated on alumina into two fractions: predominantly polycyclic aromatic hydrocarbons; and predominantly nitrogencontaining polycyclic aromatic compounds. Crude extracts were redissolved in acetone and analyzed by gas chromatography and gas chromatography-mass spectrometry. The acetone-redissolved crude extracts from the four industrialized sites contained 5.6–313.3 μg total polycyclic aromatic compounds/g sediment and 3.0–36.4 μg other compounds/g sediment. In addition to the typical EPA priority pollutants, a substantial amount (228.7 μg/g sediment) of alkyl-polycyclic-aromatic compounds was detected in sediments from one of the industrialized sites. Extracts from the reference site contained 1.55 μg total polycyclic aromatic compounds/ g sediment. Medaka (Oryzias latipes) were exposed to multiple pulse doses of acetone-redissolved extracts and fractions. Medaka were also exposed to a known carcinogen, methylazoxymethanol acetate, to verify that chemicals produced tumors in the test fish. Acetone-redissolved extracts and fractions from contaminated sediments were toxic to medaka. Fin erosion and non-neoplastic liver abnormalities were more prevalent in medaka after exposure to acetoneredissolved extracts and fractions from contaminated sediments. Neoplasms previously associated with chemical exposure in wild fishes were induced in medaka exposed to acetone-redissolved extracts and fractions from two of the contaminated sites, but not from the reference site or controls. These findings further support the hypothesis that chemical contaminants in sediments are involved in epizootics of neoplasms in wild fishes at contaminated sites.

On the inter-instrument and the inter-laboratory transferability of a tandem mass spectral reference library: 2. Optimization and characterization of the search algorithm.

PubMed

Oberacher, Herbert; Pavlic, Marion; Libiseller, Kathrin; Schubert, Birthe; Sulyok, Michael; Schuhmacher, Rainer; Csaszar, Edina; Köfeler, Harald C

2009-04-01

A sophisticated matching algorithm developed for highly efficient identity search within tandem mass spectral libraries is presented. For the optimization of the search procedure a collection of 410 tandem mass spectra corresponding to 22 compounds was used. The spectra were acquired in three different laboratories on four different instruments. The following types of tandem mass spectrometric instruments were used: quadrupole-quadrupole-time-of-flight (QqTOF), quadrupole-quadrupole-linear ion trap (QqLIT), quadrupole-quadrupole-quadrupole (QqQ), and linear ion trap-Fourier transform ion cyclotron resonance mass spectrometer (LIT-FTICR). The obtained spectra were matched to an established MS/MS-spectral library that contained 3759 MS/MS-spectra corresponding to 402 different reference compounds. All 22 test compounds were part of the library. A dynamic intensity cut-off, the search for neutral losses, and optimization of the formula used to calculate the match probability were shown to significantly enhance the performance of the presented library search approach. With the aid of these features the average number of correct assignments was increased to 98%. For statistical evaluation of the match reliability the set of fragment ion spectra was extended with 300 spectra corresponding to 100 compounds not included in the reference library. Performance was checked with the aid of receiver operating characteristic (ROC) curves. Using the magnitude of the match probability as well as the precursor ion mass as benchmarks to rate the obtained top hit, overall correct classification of a compound being included or not included in the mass spectrometric library, was obtained in more than 95% of cases clearly indicating a high predictive accuracy of the established matching procedure. Copyright (c) 2009 John Wiley & Sons, Ltd.

Discovery of C-3 tethered 2-oxo-benzo[1,4]oxazines as potent antioxidants: Bio-inspired based design, synthesis, biological evaluation, cytotoxic and Insilico molecular docking studies

NASA Astrophysics Data System (ADS)

Sharma, Vashundhra; Jaiswal, Pradeep K.; Saran, Mukesh; Yadav, Dharmendra Kumar; Saloni; Mathur, Manas; Swami, Ajit K.; Misra, Sanjeev; Kim, Mi-hyun; Chaudhary, Sandeep

2018-03-01

The discovery of C-3 tethered 2-oxo-benzo[1,4]oxazines as potent antioxidants is disclosed. All the analogues 20a-20ab have been synthesized via “on water” ultrasound-assisted in excellent yields (upto 98%). All the compounds have been evaluated for their in vitro antioxidant activities using DPPH free radical scavenging assay as well as FRAP assay. The result showed promising antioxidant activities having IC50 values in the range of 4.74 ± 0.08 to 92.20 ± 1.54 μg/mL taking ascorbic acid (IC50 = 4.57 μg/mL) as standard reference. In this study, compounds 20b and 20t, the most active compound of the series, showed IC50 values of 6.89 ± 0.07μg/mL and 4.74 ± 0.08 μg/mL, respectively in comparison with ascorbic acid. In addition, the detailed SAR study shows that electron-withdrawing group increases antioxidant activity and vice versa. Furthermore, in the FRAP assay, eight compounds (20c, 20j, 20m, 20n, 20r, 20u, 20z and 20aa) were found more potent than standard reference BHT (C0.5FRAP = 546.0 ± 13.6 μM). The preliminary cytotoxic study reveals the non-toxic nature of active compounds 20b and 20t in non-cancerous 3T3 fibroblast cell lines in MTT assay up to 250 μg/mL concentration. The results were validated via carrying out insilico molecular docking studies of promising compounds 20a, 20b and 20t in comparison with standard reference. To the best of our knowledge, this is the first detailed study of C-3 tethered 2-oxo-benzo[1,4]oxazines as potential antioxidant agents.

Accurate determination of reference materials and natural isolates by means of quantitative (1)h NMR spectroscopy.

PubMed

Frank, Oliver; Kreissl, Johanna Karoline; Daschner, Andreas; Hofmann, Thomas

2014-03-26

A fast and precise proton nuclear magnetic resonance (qHNMR) method for the quantitative determination of low molecular weight target molecules in reference materials and natural isolates has been validated using ERETIC 2 (Electronic REference To access In vivo Concentrations) based on the PULCON (PULse length based CONcentration determination) methodology and compared to the gravimetric results. Using an Avance III NMR spectrometer (400 MHz) equipped with a broad band observe (BBO) probe, the qHNMR method was validated by determining its linearity, range, precision, and accuracy as well as robustness and limit of quantitation. The linearity of the method was assessed by measuring samples of l-tyrosine, caffeine, or benzoic acid in a concentration range between 0.3 and 16.5 mmol/L (r(2) ≥ 0.99), whereas the interday and intraday precisions were found to be ≤2%. The recovery of a range of reference compounds was ≥98.5%, thus demonstrating the qHNMR method as a precise tool for the rapid quantitation (~15 min) of food-related target compounds in reference materials and natural isolates such as nucleotides, polyphenols, or cyclic peptides.

Development of urine standard reference materials for metabolites of organic chemicals including polycyclic aromatic hydrocarbons, phthalates, phenols, parabens, and volatile organic compounds.

PubMed

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.

Development of urine standard reference materials for metabolites of organic chemicals including polycyclic aromatic hydrocarbons, phthalates, phenols, parabens, and volatile organic compounds

PubMed Central

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

2016-01-01

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. PMID:25651899

Synthesis of Novel Compounds as New Potent Tyrosinase Inhibitors

PubMed Central

Hamidian, Hooshang

2013-01-01

In the present paper, we report the synthesis and pharmacological evaluation of a new series of azo compounds with different groups (1-naphthol, 2-naphthol, and N,N-dimethylaniline) and trifluoromethoxy and fluoro substituents in the scaffold. All synthesized compounds (5a–5f) showed the most potent mushroom tyrosinase inhibition (IC50 values in the range of 4.39 ± 0.76–1.71 ± 0.49 µM), comparable to the kojic acid, as reference standard inhibitor. All the novel compounds were characterized by FT-IR, 1H NMR, 13C NMR, and elemental analysis. PMID:24260737

[Molecular cloning and characterization of a novel Clonorchis sinensis antigenic protein containing tandem repeat sequences].

PubMed

Liu, Qian; Xu, Xue-Nian; Zhou, Yan; Cheng, Na; Dong, Yu-Ting; Zheng, Hua-Jun; Zhu, Yong-Qiang; Zhu, Yong-Qiang

2013-08-01

To find and clone new antigen genes from the lambda-ZAP cDNA expression library of adult Clonorchis sinensis, and determine the immunological characteristics of the recombinant proteins. The cDNA expression library of adult C. sinensis was screened by pooled sera of clonorchiasis patients. The sequences of the positive phage clones were compared with the sequences in EST database, and the full-length sequence of the gene (Cs22 gene) was obtained by RT-PCR. cDNA fragments containing 2 and 3 times tandem repeat sequences were generated by jumping PCR. The sequence encoding the mature peptide or the tandem repeat sequence was respectively cloned into the prokaryotic expression vector pET28a (+), and then transformed into E. coli Rosetta DE3 cells for expression. The recombinant proteins (rCs22-2r, rCs22-3r, rCs22M-2r, and rCs22M-3r) were purified by His-bind-resin (Ni-NTA) affinity chromatography. The immunogenicity of rCs22-2r and rCs22-3r was identified by ELISA. To evaluate the immunological diagnostic value of rCs22-2r and rCs22-3r, serum samples from 35 clonorchiasis patients, 31 healthy individuals, 15 schistosomiasis patients, 15 paragonimiasis westermani patients and 13 cysticercosis patients were examined by ELISA. To locate antigenic determinants, the pooled sera of clonorchiasis patients and healthy persons were analyzed for specific antibodies by ELISA with recombinant protein rCs22M-2r and rCs22M-3r containing the tandem repeat sequences. The full-length sequence of Cs22 antigen gene of C. sinensis was obtained. It contained 13 times tandem repeat sequences of EQQDGDEEGMGGDGGRGKEKGKVEGEDGAGEQKEQA. Bioinformatics analysis indicated that the protein (Cs22) belonged to GPI-anchored proteins family. The recombinant proteins rCs22-2r and rCs22-3r showed a certain level of immunogenicity. The positive rate by ELISA coated with the purified PrCs22-2r and PrCs22-3r for sera of clonorchiasis patients both were 45.7% (16/35), and 3.2% (1/31) for those of healthy persons. There was no cross reaction with sera of schistosomiasis and cysticercosis patients. The cross reaction with sera of paragonimiasis westermani patients was 1/15. The recombinant proteins rCs22M-2r and rCs22M-3r which only contained tandem repeats were specifically recognized by pooled sera of clonorchiasis patients. The Cs22 antigen gene of Clonorchis sinensis is obtained, and the recombinant proteins have certain diagnostic value. The antigenic determinant is located in tandem repeat sequences.

A concentration-dependent multi-term linear free energy relationship for sorption of organic compounds to soils based on the hexadecane dilute-solution reference state.

PubMed

Zhu, Dongqiang; Pignatello, Joseph J

2005-11-15

A LFER of the type in the title is applied to sorption of numerous compounds to polyethylene and three soils for which sorption to natural organic matter (NOM) is presumed dominant. It provides fractional contributions to the Gibbs free energy of sorption corresponding to hydrophobic effects, dipolar/polarizability (D/P) effects in excess of the reference state, and the sum of possible specific forces such as H-bonding and pi-pi electron donor-acceptor (pi-pi EDA) interactions in excess of the reference state. Minimal inputs are the isotherm, the n-hexadecane-water partition coefficient and the Abraham pi parameter representing D/P effects. Sorption of all compounds to polyethylene can be described by considering only hydrophobic effects. Sorption of a calibration set of apolar compounds (aromatic and aliphatic hydrocarbons and chlorinated hydrocarbons) to the natural sorbents is well-described by a combination of hydrophobic and D/P effects. For the apolar set, D/P contributes approximately 15-40% (2-8% for cyclohexane) of sorption free energy. D/P effects increase with the degree of chlorination for aliphatic compounds. For aromatic compounds D/P effects increase with fused ring size but do not vary with degree of chlorination and chlorine substitution pattern. H-bonding contributes substantially to sorption of alcohols, and similarly for 2-nonanol and 2,4-dichlorophenol (33-44%). pi-pi EDA forces contribute to phenanthrene sorption in one case. The effects of concentration, sorbent aromaticity (literature NMR), and sorbent polarity [(O + N)/C] on hydrophobic and D/P contributions for all compounds indicate that (a) molecules fill sites of progressively greater hydrophilic character; (b) the energy penalty for cavity formation in the solid decreases with concentration due to plasticization and greater intermolecular contact; (c) sorbent aromatic content more than sorbent polarity controls D/P interactions. Basing free energy on an inert electrostatic chemical environment afforded by n-hexadecane permits evaluation of direct electrostatic forces in NOM that contribute to sorption.

Solubility Database

National Institute of Standards and Technology Data Gateway

SRD 106 IUPAC-NIST Solubility Database (Web, free access)   These solubilities are compiled from 18 volumes (Click here for List) of the International Union for Pure and Applied Chemistry(IUPAC)-NIST Solubility Data Series. The database includes liquid-liquid, solid-liquid, and gas-liquid systems. Typical solvents and solutes include water, seawater, heavy water, inorganic compounds, and a variety of organic compounds such as hydrocarbons, halogenated hydrocarbons, alcohols, acids, esters and nitrogen compounds. There are over 67,500 solubility measurements and over 1800 references.

Proceedings of the Tri-Service Conference on Corrosion Held in Atlantic City, New Jersey on 17-19 October 1989

DTIC Science & Technology

1989-10-19

installation. 4. Corrosion inhibiting compounds need to be applied in the final assealbly of models to all corrosion prone areas of the structure, e.g...Figure 12 shows an example of poor surface treatment of a previously repaired stringer area. Application of a corrosion inhibiting compound may have... compounds and a good corrosion control maintenance program. REFERENCE U. G. Goranson and M. Miller, "Aging Fleet - Aging Fleet Evaluation Program

Scales of Hydrogen-Bonding Workshop Held in London, England on 1-3 July 1987

DTIC Science & Technology

1987-07-03

medium (a perfluorinated compound , FC-75), hoping to attain the basicity of CF3 CH2OH and (CF 3.2CHOH. The frequency shifts of the 3818 cm v(OH) band of...bond basicity for nonassoclated compounds , pro.ided that the reference acids in each case led toi*values that were almost the same - around 65". ’ 1...experimental measurements JOSE-LOUIS M. ABBOUD * The hydrogen-bonding basicity of oxygen and sulphur compounds MICHAEL H. ABRAHAM, PRISCILLA L

Natural Products as a Source of Alzheimer’s Drug Leads

PubMed Central

Sorribas, Analia; Howes, Melanie-Jayne R.

2016-01-01

This review focuses on recent developments in the use of natural products as therapeutics for Alzheimer’s disease. Compounds span a diverse array of structural classes and are organized according to their mechanism of action, with the focus primarily on the major hypotheses. Overall, the review discusses more than 180 compounds and summarizes 393 references. PMID:21072430

Assessment of a recombinant androgen receptor binding assay: initial steps towards validation.

PubMed

Freyberger, Alexius; Weimer, Marc; Tran, Hoai-Son; Ahr, Hans-Jürgen

2010-08-01

Despite more than a decade of research in the field of endocrine active compounds with affinity for the androgen receptor (AR), still no validated recombinant AR binding assay is available, although recombinant AR can be obtained from several sources. With funding from the European Union (EU)-sponsored 6th framework project, ReProTect, we developed a model protocol for such an assay based on a simple AR binding assay recently developed at our institution. Important features of the protocol were the use of a rat recombinant fusion protein to thioredoxin containing both the hinge region and ligand binding domain (LBD) of the rat AR (which is identical to the human AR-LBD) and performance in a 96-well plate format. Besides two reference compounds [dihydrotestosterone (DHT), androstenedione] ten test compounds with different affinities for the AR [levonorgestrel, progesterone, prochloraz, 17alpha-methyltestosterone, flutamide, norethynodrel, o,p'-DDT, dibutylphthalate, vinclozolin, linuron] were used to explore the performance of the assay. At least three independent experiments per compound were performed. The AR binding properties of reference and test compounds were well detected, in terms of the relative ranking of binding affinities, there was good agreement with published data obtained from experiments using recombinant AR preparations. Irrespective of the chemical nature of the compound, individual IC(50)-values for a given compound varied by not more than a factor of 2.6. Our data demonstrate that the assay reliably ranked compounds with strong, weak, and no/marginal affinity for the AR with high accuracy. It avoids the manipulation and use of animals, as a recombinant protein is used and thus contributes to the 3R concept. On the whole, this assay is a promising candidate for further validation. Copyright 2009 Elsevier Inc. All rights reserved.

Internal Reflection Spectra of Surface Compounds and Adsorbed Molecules

NASA Astrophysics Data System (ADS)

Zolotarev, V. M.; Lygin, V. I.; Tarasevich, B. N.

1981-01-01

The application of attenuated total reflection (ATR) spectroscopy in surface studies of inorganic adsorbents and catalysts, polymers, and optically transparent electrodes is discussed. The basic principles of ATR spectroscopy as applied to surface phenomena are considered, with special reference to thin films, industrial adsorbents and catalysts, and polymer degradation processes. 276 references.

Free radical scavenging capacity, anticandicidal effect of bioactive compounds from Sida cordifolia L., in combination with nystatin and clotrimazole and their effect on specific immune response in rats.

PubMed

Ouédraogo, Maurice; Konaté, Kiessoun; Lepengué, Alexis Nicaise; Souza, Alain; M'Batchi, Bertrand; Sawadogo, Laya L

2012-12-26

Infectious diseases caused by fungi are still a major threat to public health, despite numerous efforts by researchers. Use of ethnopharmacological knowledge is one attractive way to reduce empiricism and enhance the probability of success in new drug-finding efforts. In this work, the total alkaloid compounds (AC) from Sida cordifolia L. (Malvaceae) have been investigated for their free radical scavenging capacity, antifungal and immunostimulatory properties. The antifungal activity was investigated against five candida strains using the microplate dilution method and the Fractional Inhibitory Concentration Index (FICI) of compounds was evaluated. The antioxidant activity of the samples was evaluate using three separate methods, at last, the immunostimulatory effect on immunosuppressed wistar rats was performed. As for the antifungal activity, result varied according to microorganism. The results obtained in this antifungal activity were interesting and indicated a synergistic effect between alkaloid compounds and the antifungal references such as Nystatin and Clotrimazole. Antioxidant capacity noticed that the reduction capacity of DPPH radicals obtained the best result comparatively to the others methods of free radical scavenging. Our results showed a low immunostimulatory effect and this result could be explained by the lack of biologically active antioxidants such as polyphenol compounds lowly contained in the alkaloid compounds. The results of this study showed that alkaloid compounds in combination with antifungal references (Nystatin and Clotrimazole) exhibited antimicrobial effects against candida strains tested. The results supported the utilization of these plants in infectious diseases particularly in treatment of candida infections.

Free radical scavenging capacity, anticandicidal effect of bioactive compounds from Sida Cordifolia L., in combination with nystatin and clotrimazole and their effect on specific immune response in rats

PubMed Central

2012-01-01

Background Infectious diseases caused by fungi are still a major threat to public health, despite numerous efforts by researchers. Use of ethnopharmacological knowledge is one attractive way to reduce empiricism and enhance the probability of success in new drug-finding efforts. In this work, the total alkaloid compounds (AC) from Sida cordifolia L. (Malvaceae) have been investigated for their free radical scavenging capacity, antifungal and immunostimulatory properties. Method The antifungal activity was investigated against five candida strains using the microplate dilution method and the Fractional Inhibitory Concentration Index (FICI) of compounds was evaluated. The antioxidant activity of the samples was evaluate using three separate methods, at last, the immunostimulatory effect on immunosuppressed wistar rats was performed. Results As for the antifungal activity, result varied according to microorganism. The results obtained in this antifungal activity were interesting and indicated a synergistic effect between alkaloid compounds and the antifungal references such as Nystatin and Clotrimazole. Antioxidant capacity noticed that the reduction capacity of DPPH radicals obtained the best result comparatively to the others methods of free radical scavenging. Our results showed a low immunostimulatory effect and this result could be explained by the lack of biologically active antioxidants such as polyphenol compounds lowly contained in the alkaloid compounds. Conclusion The results of this study showed that alkaloid compounds in combination with antifungal references (Nystatin and Clotrimazole) exhibited antimicrobial effects against candida strains tested. The results supported the utilization of these plants in infectious diseases particularly in treatment of candida infections. PMID:23268761

Scoring ligand similarity in structure-based virtual screening.

PubMed

Zavodszky, Maria I; Rohatgi, Anjali; Van Voorst, Jeffrey R; Yan, Honggao; Kuhn, Leslie A

2009-01-01

Scoring to identify high-affinity compounds remains a challenge in virtual screening. On one hand, protein-ligand scoring focuses on weighting favorable and unfavorable interactions between the two molecules. Ligand-based scoring, on the other hand, focuses on how well the shape and chemistry of each ligand candidate overlay on a three-dimensional reference ligand. Our hypothesis is that a hybrid approach, using ligand-based scoring to rank dockings selected by protein-ligand scoring, can ensure that high-ranking molecules mimic the shape and chemistry of a known ligand while also complementing the binding site. Results from applying this approach to screen nearly 70 000 National Cancer Institute (NCI) compounds for thrombin inhibitors tend to support the hypothesis. EON ligand-based ranking of docked molecules yielded the majority (4/5) of newly discovered, low to mid-micromolar inhibitors from a panel of 27 assayed compounds, whereas ranking docked compounds by protein-ligand scoring alone resulted in one new inhibitor. Since the results depend on the choice of scoring function, an analysis of properties was performed on the top-scoring docked compounds according to five different protein-ligand scoring functions, plus EON scoring using three different reference compounds. The results indicate that the choice of scoring function, even among scoring functions measuring the same types of interactions, can have an unexpectedly large effect on which compounds are chosen from screening. Furthermore, there was almost no overlap between the top-scoring compounds from protein-ligand versus ligand-based scoring, indicating the two approaches provide complementary information. Matchprint analysis, a new addition to the SLIDE (Screening Ligands by Induced-fit Docking, Efficiently) screening toolset, facilitated comparison of docked molecules' interactions with those of known inhibitors. The majority of interactions conserved among top-scoring compounds for a given scoring function, and from the different scoring functions, proved to be conserved interactions in known inhibitors. This was particularly true in the S1 pocket, which was occupied by all the docked compounds. (c) 2009 John Wiley & Sons, Ltd.

Identification of nonvolatile compounds in clove (Syzygium aromaticum) from Manado

NASA Astrophysics Data System (ADS)

Fathoni, A.; Saepudin, E.; Cahyana, A. H.; Rahayu, D. U. C.; Haib, J.

2017-07-01

Syzygium aromaticum (clove) are native to Indonesia and have been widely used in food industry due to their flavor. Nonvolatile compounds contribute to flavor, mainly in their taste. Currently, there is very little information available about nonvolatile compounds in clove. Identification of nonvolatile compounds is important to improve clove's value. Compound extraction was conducted by maceration in ethanol. Fractionations of the extract were performed by using gravity column chromatography on silica gel and Sephadex LH-20 as stationary phase. Nonvolatile compounds were identified by Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS). LC-MS/MS was operated in negative mode with 0.1 % formic acid in water and acetonitrile as mobile phase. Nonvolatile compounds were identified by fragment analysis and compared to references. Several compounds had been identified and characterized asquinic acid, monogalloylglucose, gallic acid, digalloylglucose, isobiflorin, biflorin, ellagic acid, hydroxygallic acid, luteolin, quercetin, naringenin, kaempferol, isorhamnetin, dimethoxyluteolin, and rhamnetin. These compounds had two main flavor perceptions, i.e. astringent, and bitter.

Synthesis and antitumour activity of 4-aminoquinazoline derivatives

NASA Astrophysics Data System (ADS)

Lipunova, G. N.; Nosova, E. V.; Charushin, V. N.; Chupakhin, O. N.

2016-07-01

Pieces of data on the synthesis and antitumour activity of 4-aminoquinazolines are summarized and analyzed. Key methods for the synthesis of these compounds are considered, primarily cyclocondensation of carboxylic acid derivatives, as well as the oxidation of quinazolines and the cyclization of disubstituted thioureas. Improvements of synthetic schemes for erlotinib, gefitinib and lapatinib, which are the best-known pharmaceuticals based on compounds of the title class, are also considered. Synthetic strategies and biological activities for new 4-aminoquinazoline derivatives that are EGFR-tyrosine kinase inhibitors, multiactive compounds, and labelled compounds for use as positron emission tomography (PET) imaging agents are discussed. The bibliography includes 263 references.

Recent advances in the chemistry of Rh carbenoids: multicomponent reactions of diazocarbonyl compounds

NASA Astrophysics Data System (ADS)

Medvedev, J. J.; Nikolaev, V. A.

2015-07-01

Multicomponent reactions of diazo compounds catalyzed by RhII complexes become a powerful tool for organic synthesis. They enable three- or four-step processes to be carried out as one-pot procedures (actually as one step) with high stereoselectivity to give complex organic molecules, including biologically active compounds. This review addresses recent results in the chemistry of Rh-catalyzed multicomponent reactions of diazocarbonyl compounds with the intermediate formation of N-, O- and C=O-ylides. The diastereo- and enantioselectivity of these reactions and the possibility of using various co-catalysts to increase the efficiency of the processes under consideration are discussed. The bibliography includes 120 references.

3D flexible alignment using 2D maximum common substructure: dependence of prediction accuracy on target-reference chemical similarity.

PubMed

Kawabata, Takeshi; Nakamura, Haruki

2014-07-28

A protein-bound conformation of a target molecule can be predicted by aligning the target molecule on the reference molecule obtained from the 3D structure of the compound-protein complex. This strategy is called "similarity-based docking". For this purpose, we develop the flexible alignment program fkcombu, which aligns the target molecule based on atomic correspondences with the reference molecule. The correspondences are obtained by the maximum common substructure (MCS) of 2D chemical structures, using our program kcombu. The prediction performance was evaluated using many target-reference pairs of superimposed ligand 3D structures on the same protein in the PDB, with different ranges of chemical similarity. The details of atomic correspondence largely affected the prediction success. We found that topologically constrained disconnected MCS (TD-MCS) with the simple element-based atomic classification provides the best prediction. The crashing potential energy with the receptor protein improved the performance. We also found that the RMSD between the predicted and correct target conformations significantly correlates with the chemical similarities between target-reference molecules. Generally speaking, if the reference and target compounds have more than 70% chemical similarity, then the average RMSD of 3D conformations is <2.0 Å. We compared the performance with a rigid-body molecular alignment program based on volume-overlap scores (ShaEP). Our MCS-based flexible alignment program performed better than the rigid-body alignment program, especially when the target and reference molecules were sufficiently similar.

Developing an Activity and Absorption-based Quality Control Platform for Chinese Traditional Medicine: Application to Zeng-Sheng-Ping

PubMed Central

Yin, Taijun; Yang, Guanyi; Ma, Yong; Xu, Beibei; Hu, Ming; You, Ming; Gao, Song

2015-01-01

Ethnopharmacological relevance Zeng-Sheng-Ping (ZSP) is a marketed Chinese traditional medicine used for cancer prevention. Aim of the study Currently, for the quality control of Chinese traditional medicines, marker compounds are not selected based on bioactivities and pharmaceutical behaviors in most of the cases. Therefore, even if the “quality” of the medicine is controlled, the pharmacological effect could still be inconsistent. The aim of this study is to establish an activity and absorption-based platform to select marker compound(s) for the quality control of Chinese traditional medicines. Materials and methods We used ZSP as a reference Chinese traditional medicine to establish the platform. Activity guided fractionation approach was used to purify the major components from ZSP. NMR and MS spectra were used to elucidate the structure of the isolated compounds. MTT assay against oral carcinoma cell line (SCC2095) was performed to evaluate the activities. UPLC-MS/MS was used to quantify the pure compounds in ZSP and the active fraction. The permeabilities of the identified compounds were evaluated in the Caco-2 cell culture model. The intracellular accumulation of the isolated compounds was evaluated in the SCC2095 cells. Results The major compounds were identified from ZSP. The contents, anti-proliferation activities, permeabilities, and intracellular accumulations of these compounds were also evaluated. The structure of these purified compounds were identified by comparing the NMR and MS data with those of references as rutaevine (1), limonin (2) , evodol (3), obacunone (4), fraxinellone (5), dictamnine (6), maackiain (7), trifolirhizin (8), and matrine (9). The IC50 of compounds 5, 6, and 7 against SCC2095 cells were significantly lower than that of ZSP. The uptake permeability of compounds 5, 6, and 7 were 2.58 ± 0. 3 × 10−5, 4.33 ± 0.5 × 10−5, and 4.27 ± 0.8 × 10−5 respectively in the Caco-2 cell culture model. The intracellular concentrations of these compounds showed that compounds 5, 6, and 7 were significantly accumulated inside the cells. Conclusion Based on the activity against oral carcinoma cell line as well as the absorption permeability, compound 5, 6, and 7 are selected as quality control markers for ZSP. A activity and absorption-based platform was established and successfully used for the quality control of ZSP. PMID:26099633

Effects of oakmoss and its components on biofilm formation of Legionella pneumophila.

PubMed

Nomura, Harue; Isshiki, Yasunori; Sakuda, Keisuke; Sakuma, Katsuya; Kondo, Seiichi

2013-01-01

Oakmoss and its components are known as antibacterial agents, specifically against Legionella pneumophila. In the present study, we investigated the effects of oakmoss and its components (phenol, didepside and isochromen derivatives) on L. pneumophila biofilm formation, with particular reference to the bactericidal activity (minimum bactericidal concentration; MBC) of these components against the bacterial cells in the biofilm. Of the 20 compounds tested, two didepside derivatives and four phenol derivatives reduced biofilm formation by more than 50% of that observed for the control at their respective minimum inhibitory concentrations (1/2×MIC). The inhibitory activities of these compounds were either equivalent to or greater than that of the clarithromycin reference. Isochromen derivatives had no effect on biofilm formation. Analysis of bactericidal activity of didepside and isochromen derivatives revealed that three of four didepside derivatives and one of four isochromen derivatives exhibited high bactericidal activity (MBC: 32.0-74.7 µg/mL) against the L. pneumophila in the biofilm after 24 h or 48 h of co-incubation; the antibacterial activities of these compounds were almost equivalent to clarithromycin and chlorhexidine gluconate (MBC: 42.7-64.0 µg/mL) that were used as references. Thus, based on their anti-biofilm forming and bactericidal activities, didepside derivatives are considered to be good candidates for disinfectants against L. pneumophila.

Synthesis and anti-lung cancer activity of a novel arsenomolybdate compound

NASA Astrophysics Data System (ADS)

Zhu, Tian-Tian; Wang, Juan; Chen, Song-Hu

2017-12-01

The new compound based on Wells-Dawson-type arsenomolybdate: [{Cu10(pz)11Cl4}{As2IIIAs2VMo6VMo12VIO62}]·H2O (1) has been hydrothermally synthesized and characterized by single-crystal X-ray diffraction analysis, X-ray powder diffraction (XRPD), XPS spectroscopy and thermogravimetric analysis (TG). Compound 1 is consisted of two As caps Wells-dawson-type arsenomolybdate and {Cu10(py)11} complexes by chloride bridge. In addition, the antitumor effects of the title compound 1 were studied on three human lung cancer cells (A549, SK-LU-1 and SW1573). The results showed that compared with the positive reference drug carboplatin, compound 1 displayed efficient antitumor activity.

Synthesis and topoisomerase II inhibitory and cytotoxic activity of oxiranylmethoxy- and thiiranylmethoxy-chalcone derivatives.

PubMed

Na, Younghwa; Nam, Jung-Min

2011-01-01

In order to find potential anticancer drug candidate targeting topoisomerases enzyme, we have designed and synthesized oxiranylmethoxy- and thiiranylmethoxy-retrochalcone derivatives and evaluated their pharmacological activity including topoisomerases inhibitory and cytotoxic activity. Of the compounds prepared compound 25 showed comparable or better cytotoxic activity against cancer cell lines tested. Compound 25 inhibited MCF7 (IC(50): 0.49 ± 0.21 μM) and HCT15 (IC(50): 0.23 ± 0.02 μM) carcinoma cell growth more efficiently than references. In the topoisomerases inhibition test, all the compounds were inactive to topoisomerase I but moderate inhibitors to topoisomerase II enzyme. Especially, compound 25 inhibited topoisomerase II activity with comparable extent to etoposide at 100 μM concentrations. Correlation between cytotoxicity and topoisomerase II inhibitory activity implies that compound 25 can be a possible lead compound for anticancer drug impeding the topoisomerase II function. Copyright © 2010 Elsevier Ltd. All rights reserved.

DEVELOPMENT OF A SYSTEMATIC APPROACH TO ACCURATELY MEASURE TRACE LEVELS OF VOLATILE ORGANIC COMPOUNDS (VOCS) IN SOIL AND SEDIMENT CONTAINING HIGH MOISTURE TO MEET THE EPA'S RISK ASSESSMENT NEEDS

EPA Science Inventory

A majority of the contaminated sites within the United States contain volatile organic compounds (VOCs), either as industrial chlorinated solvents or petroleum products commonly referred to as BTEX (benzene, toluene, ethyl benzene, and xylene). The present EPA methods for low le...

Measurement and Modeling of Ecosystem Risk and Recovery for In Situ Treatment of Contaminated Sediments

DTIC Science & Technology

2011-02-01

µECD Gas chromatography - micro electron capture detector HPAH high molecular weight polyaromatic hydrocarbon HOC Hydrophobic organic compound IR...hydrocarbon PCB Polychlorinated biphenyl PE Polyethylene PED Polyethylene devices PFC Perfluorinated chemical POM Polyoxymethylene PRC...Performance reference compound RMSE Root Mean Squared Error SPME Solid Phase Micro Extraction SERDP Strategic Environmental Research and Development

Characterization of Sulfur Compounds in Coffee Beans by Sulfur K-XANES Spectroscopy

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

Lichtenberg, H.; Hormes, J.; Institute of Physics, University of Bonn, Nussallee 12, 53115 Bonn

2007-02-02

In this 'feasibility study' the influence of roasting on the sulfur speciation in Mexican coffee beans was investigated by sulfur K-XANES Spectroscopy. Spectra of green and slightly roasted beans could be fitted to a linear combination of 'standard' reference spectra for biological samples, whereas longer roasting obviously involves formation of additional sulfur compounds in considerable amounts.

40 CFR 63.1433 - Wastewater provisions.

Code of Federal Regulations, 2014 CFR

2014-07-01

... exclusively to organic HAP listed on Table 8 of 40 CFR part 63, subpart G. (ii) When the HON requirements in §§ 63.132 through 63.149 refer to Table 9 compounds, the owner or operator is only required to consider compounds that meet the definition of organic HAP in § 63.1423 and that are listed in Table 9 of 40 CFR part...

Natural Products Research in China from 2015 to 2016

NASA Astrophysics Data System (ADS)

Liu, Haishan; Zhu, Guoliang; Fan, Yaqin; Du, Yuqi; Lan, Mengmeng; Xu, Yibo; Zhu, Weiming

2018-03-01

This review covers the literature published by Chinese chemists from 2015 to 2016 on natural products (NPs), with 1,985 citations referring to 6,944 new compounds isolated from marine or terrestrial microorganisms, plants, and animals. The emphasis is on 730 new compounds with a novel skeleton or/and significant bioactivity, together with their source organism and country of origin.

Ordinal Expressions in Japanese. Papers in Japanese Linguistics, Vol. 2, No. 1.

ERIC Educational Resources Information Center

Backus, Robert L.

The varied forms and semantic factors of Japanese ordinal expressions are related to one another in a coherent system. In Japanese, the cardinal number form is a numeral compound in construction with a referent. The numeral compound consists of a number and a numeral adjunct. Numeral adjuncts are derived from bound forms, or numeral suffixes, and…

Anti-Helicobacter pylori activities of selected N-substituted cinnamamide derivatives evaluated on reference and clinical bacterial strains.

PubMed

Klesiewicz, Karolina; Karczewska, Elżbieta; Nowak, Paweł; Skiba-Kurek, Iwona; Sito, Edward; Pańczyk, Katarzyna; Koczurkiewicz, Paulina; Żelaszczyk, Dorota; Pękala, Elżbieta; Waszkielewicz, Anna M; Budak, Alicja; Marona, Henryk; Gunia-Krzyżak, Agnieszka

2018-05-01

In this study, thirty-five N-substituted derivatives of cinnamic acid amide (cinnamamide) were evaluated for anti-Helicobacter pylori activity using an agar disc-diffusion method. Qualitative screening was performed on a reference H. pylori strain (ATCC 43504), resulting in the identification of the three most active compounds, 8 (R,S-(2E)-3-(4-chlorophenyl)-N-(2-hydroxypropyl)prop-2-enamide, minimal inhibitory concentration, MIC = 7.5 µg/mL), 23 ((2E)-3-(4-chlorophenyl)-N-(2-hydroxycyclohexyl)prop-2-enamide, MIC = 10 µg/mL), and 28 ((2E)-3-(4-chlorophenyl)-N-(4-oxocyclohexyl)prop-2-enamide, MIC = 10 µg/mL). These compounds were further tested on twelve well-characterized clinical strains, yielding MIC values that ranged from 10 to 1000 µg/mL. Preliminary safety assessments of the compounds were made using the MTT viability test for cytotoxicity and Ames test for mutagenicity, which showed them to be generally safe, although compounds 8 and 28 showed mutagenic activity at some of the tested concentrations. The results of this study showed the anti-H. pylori potential of cinnamamide derivatives.

Methods for the synthesis of donor-acceptor cyclopropanes

NASA Astrophysics Data System (ADS)

Tomilov, Yu V.; Menchikov, L. G.; Novikov, R. A.; Ivanova, O. A.; Trushkov, I. V.

2018-03-01

The interest in cyclopropane derivatives is caused by the facts that, first, the three-carbon ring is present in quite a few natural and biologically active compounds and, second, compounds with this ring are convenient building blocks for the synthesis of diverse molecules (acyclic, alicyclic and heterocyclic). The carbon–carbon bonds in cyclopropane are kinetically rather inert; hence, they need to be activated to be involved in reactions. An efficient way of activation is to introduce vicinal electron-donating and electron-withdrawing substituents into the ring; these substrates are usually referred to as donor-acceptor cyclopropanes. This review gives a systematic account of the key methods for the synthesis of donor-acceptor cyclopropanes. The most important among them are reactions of nucleophilic alkenes with diazo compounds and iodonium ylides and approaches based on reactions of electrophilic alkenes with sulfur ylides (the Corey–Chaykovsky reaction). Among other methods used for this purpose, noteworthy are cycloalkylation of CH-acids, addition of α-halocarbonyl compounds to alkenes, cyclization via 1,3-elimination, reactions of alkenes with halocarbenes followed by reduction, the Simmons–Smith reaction and some other. The scope of applicability and prospects of various methods for the synthesis of donor-acceptor cyclopropanes are discussed. The bibliography includes 530 references.

Identification and quantitation of all-trans- and 13-cis-retinoic acid and 13-cis-4-oxoretinoic acid in human plasma.

PubMed

Eckhoff, C; Nau, H

1990-08-01

Human plasma was analyzed by high performance liquid chromatography for the presence of retinoic acid and 4-oxoretinoic acid isomers. Peaks that coeluted with the reference compounds all-trans-retinoic acid, 13-cis-retinoic acid, and 13-cis-4-oxoretinoic acid were routinely observed in human plasma. These retinoids were unequivocally identified by the following methods: comigration with reference compounds under several high performance liquid chromatographic conditions; comparison of ultraviolet spectra with those of reference compounds; derivatization with diazomethane and coelution of the methyl esters with reference compounds in a high performance liquid chromatographic system as well as in a gas chromatography system with a mass selective detector. In vitro formation of 13-cis-retinoic acid and 13-cis-4-oxoretinoic acid as artifacts during the analytical procedure was excluded by control experiments. The mean plasma concentrations of the vitamin A metabolites in ten male volunteers were: all-trans-retinoic acid: 1.32 +/- 0.46 ng/ml; 13-cis-retinoic acid: 1.63 +/- 0.85 ng/ml; and 13-cis-4-oxoretinoic acid: 3.68 +/- 0.99 ng/ml. After oral dosing with vitamin A (833 IU/kg body weight) in five male volunteers, mean plasma all-trans-retinoic acid increased to 3.92 +/- 1.40 ng/ml and 13-cis-retinoic acid increased to 9.75 +/- 2.18 ng/ml. Maximal plasma 13-cis-4-oxoretinoic acid concentrations (average 7.60 +/- 1.45 ng/ml) were observed 6 h after dosing which was the last time point in this study. Concentrations of all-trans-4-oxoretinoic acid were low or not detectable. Our findings suggest that, in addition to all-trans-retinoic acid, 13-cis-retinoic acid and 13-cis-4-oxoretinoic acid are present in normal human plasma as metabolites of vitamin A.

The south Karelia air pollution study: Effects of low-level expsoure to malodorous sulfur compounds on symptoms

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

Partti-Pellinen, K.; Marttila, O.; Vilkka, V.

1996-07-01

Exposure to very low levels of ambient-air malodorous sulfur compounds and their effect on eye irritation, respiratory-tract symptoms, and central nervous system symptoms in adults were assessed. A cross-sectional self-administered questionnaire (response rate = 77%) was distributed during March and April 1992 to adults (n = 336) who lived in a neighborhood that contained a pulp mill and in a nonpolluted reference community (n = 380). In the exposed community, the measured annual mean concentrations of total reduced sulfur compounds and sulfur dioxide measured in two stations were 2 to 3 {mu}g/m{sup 3} and 1 {mu}g/m{sup 3}, respectively. In themore » reference community, the annual mean concentration of sulfur dioxide was 1 {mu}g/m{sup 3}. The residents of the community near the pulp mill reported an excess of cough, respiratory infections, and headache during the previous 4 wk, as well as during the preceding 12 mo. The relative risk for headache was increased significantly in the exposed community, compared with the reference area: the adjusted odds ratio (aOR) was 1.83 (95% confidence interval [95% Cl] = 1.06-3.15) during the previous 4 wk and 1.70 (95% Cl = 1.05-2.73) during the preceding 12 mo. The relative risk for cough was also increased during the preceding 12 mo (aOR = 1.64, 95% Cl = 1.01-2.64). These results indicated that adverse health effects of malodorous sulfur compounds occur at lower concentrations than reported previously. 25 refs., 3 tabs.« less

Volatilization of benzene and eight alkyl-substituted benzene compounds from water

USGS Publications Warehouse

Rathbun, R.E.; Tai, D.Y.

1988-01-01

Predicting the fate of organic compounds in streams and rivers often requires knowledge of the volatilization characteristics of the compounds. The reference-substance concept, involving laboratory-determined ratios of the liquid-film coefficients for volatilization of the organic compounds to the liquid-film coefficient for oxygen absorption, is used to predict liquid-film coefficients for streams and rivers. In the absence of experimental data, two procedures have been used for estimating these liquid-film coefficient ratios. These procedures, based on the molecular-diffusion coefficient and on the molecular weight, have been widely used but never extensively evaluated. Liquid-film coefficients for the volatilization of benzene and eight alkyl-substituted benzene compounds (toluene through n-octylbenzene) from water were measured in a constant-temperature, stirred water bath. Liquid-film coefficients for oxygen absorption were measured simultaneously. A range of water mixing conditions was used with a water temperature of 298.2 K. The ratios of the liquid-film coefficients for volatilization to the liquid-film coefficient for oxygen absorption for all of the organic compounds were independent of mixing conditions in the water. Experimental ratios ranged from 0.606 for benzene to 0.357 for n-octylbenzene. The molecular-diffusion-coefficient procedure accurately predicted the ratios for ethylbenzene through n-pentylbenzene with a power dependence of 0.566 on the molecular-diffusion coefficient, in agreement with published values. Predicted ratios for benzene and toluene were slightly larger than the experimental ratios. These differences were attributed to possible interactions between the molecules of these compounds and the water molecules and to benzene-benzene interactions that form dimers. Because these interactions also are likely to occur in natural waters, it was concluded that the experimental ratios are more correct than the predicted ratios for application purposes in the reference-substance concept. Predicted ratios for n-hexylbenzene, n-heptylbenzene, and n-octylbenzene were larger than the experimental ratios. These differences were attributed to a sorption-desorption process between these compounds and the surfaces of the constant-temperature water bath. Other experimental problems associated with preparing water solutions of these slightly soluble compounds also may have contributed to the differences. Because these processes are not part of the true volatilization process, it was concluded that the predicted ratios for these three compounds are probably more correct than the experimental ratios for application purposes in the reference-substance concept. Any model of the fate of these compounds in streams and rivers would have to include terms accounting for sorption processes, however. The molecular-weight procedure accurately predicted the ratios for ethylbenzene through n-pentylbenzene, but only if the power dependence on the molecular weight was decreased from the commonly used -0.500 to -0.427. Deviations for the low- and high-molecular-weight compounds were similar to those observed for the molecular-diffusion-coefficient procedure.

Tyrosine-like condensed derivatives as tyrosinase inhibitors.

PubMed

Matos, Maria João; Santana, Lourdes; Uriarte, Eugenio; Serra, Silvia; Corda, Marcella; Fadda, Maria Benedetta; Era, Benedetta; Fais, Antonella

2012-05-01

We report the pharmacological evaluation of a new series of 3-aminocoumarins differently substituted with hydroxyl groups, which have been synthesized because they include in their structures the tyrosine fragment (tyrosine-like compounds), with the aim of discovering structural features necessary for tyrosinase inhibitory activity. The synthesized compounds 4 and 7-9 were evaluated in vitro as mushroom tyrosinase inhibitors. Two of the described compounds showed lower IC50 (concentration giving 50% inhibition of tyrosinase activity) than umbelliferone, used as a reference compound. Compound 7 (IC50=53µm) was the best tyrosinase inhibitor of this small series, having an IC50 value 10-fold lower than umbelliferone. Compound 7 (3-amino-7-hydroxycoumarin) had amino and hydroxyl groups precisely mimicking the same positions that both groups occupy on the tyrosine molecule. © 2012 The Authors. JPP © 2012 Royal Pharmaceutical Society.

Suspect screening of large numbers of emerging contaminants in environmental waters using artificial neural networks for chromatographic retention time prediction and high resolution mass spectrometry data analysis.

PubMed

Bade, Richard; Bijlsma, Lubertus; Miller, Thomas H; Barron, Leon P; Sancho, Juan Vicente; Hernández, Felix

2015-12-15

The recent development of broad-scope high resolution mass spectrometry (HRMS) screening methods has resulted in a much improved capability for new compound identification in environmental samples. However, positive identifications at the ng/L concentration level rely on analytical reference standards for chromatographic retention time (tR) and mass spectral comparisons. Chromatographic tR prediction can play a role in increasing confidence in suspect screening efforts for new compounds in the environment, especially when standards are not available, but reliable methods are lacking. The current work focuses on the development of artificial neural networks (ANNs) for tR prediction in gradient reversed-phase liquid chromatography and applied along with HRMS data to suspect screening of wastewater and environmental surface water samples. Based on a compound tR dataset of >500 compounds, an optimized 4-layer back-propagation multi-layer perceptron model enabled predictions for 85% of all compounds to within 2min of their measured tR for training (n=344) and verification (n=100) datasets. To evaluate the ANN ability for generalization to new data, the model was further tested using 100 randomly selected compounds and revealed 95% prediction accuracy within the 2-minute elution interval. Given the increasing concern on the presence of drug metabolites and other transformation products (TPs) in the aquatic environment, the model was applied along with HRMS data for preliminary identification of pharmaceutically-related compounds in real samples. Examples of compounds where reference standards were subsequently acquired and later confirmed are also presented. To our knowledge, this work presents for the first time, the successful application of an accurate retention time predictor and HRMS data-mining using the largest number of compounds to preliminarily identify new or emerging contaminants in wastewater and surface waters. Copyright © 2015 Elsevier B.V. All rights reserved.

Mechanism of heterogeneous catalytic oxidation of organic compounds to carboxylic acids

NASA Astrophysics Data System (ADS)

Andrushkevich, T. V.; Chesalov, Yu A.

2018-06-01

The results of studies on the mechanism of heterogeneous catalytic oxidation of organic compounds of different chemical structure to carboxylic acids are analyzed and generalized. The concept developed by Academician G.K.Boreskov, according to which the direction of the reaction is governed by the structure and bond energy of surface intermediates, was confirmed taking the title processes as examples. Quantitative criteria of the bond energies of surface compounds of oxidizable reactants, reaction products and oxygen that determine the selective course of the reaction are presented. The bibliography includes 195 references.

Rationale for classification of combustible gases, vapors and dusts with reference to the National Electrical Code

NASA Astrophysics Data System (ADS)

1982-07-01

Serious reservations about the entire classification procedure of chemical compounds present in electrical equipment environments and the precepts on which it is based are discussed. Although some tests were conducted on selected key compounds, the committee primarily considered the chemical similarity of compounds and other known flammability properties and relied heavily on the experience and intuition of its members. The committee also recommended that the NEC grouping of dusts be changed in some ways and has reclassified dusts according to the modified version of the code.

GC-MS quantitation of fragrance compounds suspected to cause skin reactions. 1.

PubMed

Chaintreau, Alain; Joulain, Daniel; Marin, Christophe; Schmidt, Claus-Oliver; Vey, Matthias

2003-10-22

Recent changes in European legislation require monitoring of 24 volatile compounds in perfumes as they might elicit skin sensitization. This paper reports a GC-MS quantitation procedure for their determination in fragrance concentrates. GC and MS conditions were optimized for a routine use: analysis within 30 min, solvent and internal standard selection, and stock solution stability. Calibration curves were linear in the range of 2-100 mg/L with coefficients of determination in excess of 0.99. The method was tested using real perfumes spiked with known amounts of reference compounds.

Aromatase inhibitory activity of 1,4-naphthoquinone derivatives and QSAR study

PubMed Central

Prachayasittikul, Veda; Pingaew, Ratchanok; Worachartcheewan, Apilak; Sitthimonchai, Somkid; Nantasenamat, Chanin; Prachayasittikul, Supaluk; Ruchirawat, Somsak; Prachayasittikul, Virapong

2017-01-01

A series of 2-amino(chloro)-3-chloro-1,4-naphthoquinone derivatives (1-11) were investigated for their aromatase inhibitory activities. 1,4-Naphthoquinones 1 and 4 were found to be the most potent compounds affording IC50 values 5.2 times lower than the reference drug, ketoconazole. A quantitative structure-activity relationship (QSAR) model provided good predictive performance (R2CV = 0.9783 and RMSECV = 0.0748) and indicated mass (Mor04m and H8m), electronegativity (Mor08e), van der Waals volume (G1v) and structural information content index (SIC2) descriptors as key descriptors governing the activity. To investigate the effects of structural modifications on aromatase inhibitory activity, the model was employed to predict the activities of an additional set of 39 structurally modified compounds constructed in silico. The prediction suggested that the 2,3-disubstitution of 1,4-naphthoquinone ring with halogen atoms (i.e., Br, I and F) is the most effective modification for potent activity (1a, 1b and 1c). Importantly, compound 1b was predicted to be more potent than its parent compound 1 (11.90-fold) and the reference drug, letrozole (1.03-fold). The study suggests the 1,4-naphthoquinone derivatives as promising compounds to be further developed as a novel class of aromatase inhibitors. PMID:28827987

Prediction of response factors for gas chromatography with flame ionization detection: Algorithm improvement, extension to silylated compounds, and application to the quantification of metabolites

PubMed Central

de Saint Laumer, Jean‐Yves; Leocata, Sabine; Tissot, Emeline; Baroux, Lucie; Kampf, David M.; Merle, Philippe; Boschung, Alain; Seyfried, Markus

2015-01-01

We previously showed that the relative response factors of volatile compounds were predictable from either combustion enthalpies or their molecular formulae only 1. We now extend this prediction to silylated derivatives by adding an increment in the ab initio calculation of combustion enthalpies. The accuracy of the experimental relative response factors database was also improved and its population increased to 490 values. In particular, more brominated compounds were measured, and their prediction accuracy was improved by adding a correction factor in the algorithm. The correlation coefficient between predicted and measured values increased from 0.936 to 0.972, leading to a mean prediction accuracy of ± 6%. Thus, 93% of the relative response factors values were predicted with an accuracy of better than ± 10%. The capabilities of the extended algorithm are exemplified by (i) the quick and accurate quantification of hydroxylated metabolites resulting from a biodegradation test after silylation and prediction of their relative response factors, without having the reference substances available; and (ii) the rapid purity determinations of volatile compounds. This study confirms that Gas chromatography with a flame ionization detector and using predicted relative response factors is one of the few techniques that enables quantification of volatile compounds without calibrating the instrument with the pure reference substance. PMID:26179324

TMDB: a literature-curated database for small molecular compounds found from tea.

PubMed

Yue, Yi; Chu, Gang-Xiu; Liu, Xue-Shi; Tang, Xing; Wang, Wei; Liu, Guang-Jin; Yang, Tao; Ling, Tie-Jun; Wang, Xiao-Gang; Zhang, Zheng-Zhu; Xia, Tao; Wan, Xiao-Chun; Bao, Guan-Hu

2014-09-16

Tea is one of the most consumed beverages worldwide. The healthy effects of tea are attributed to a wealthy of different chemical components from tea. Thousands of studies on the chemical constituents of tea had been reported. However, data from these individual reports have not been collected into a single database. The lack of a curated database of related information limits research in this field, and thus a cohesive database system should necessarily be constructed for data deposit and further application. The Tea Metabolome database (TMDB), a manually curated and web-accessible database, was developed to provide detailed, searchable descriptions of small molecular compounds found in Camellia spp. esp. in the plant Camellia sinensis and compounds in its manufactured products (different kinds of tea infusion). TMDB is currently the most complete and comprehensive curated collection of tea compounds data in the world. It contains records for more than 1393 constituents found in tea with information gathered from 364 published books, journal articles, and electronic databases. It also contains experimental 1H NMR and 13C NMR data collected from the purified reference compounds or collected from other database resources such as HMDB. TMDB interface allows users to retrieve tea compounds entries by keyword search using compound name, formula, occurrence, and CAS register number. Each entry in the TMDB contains an average of 24 separate data fields including its original plant species, compound structure, formula, molecular weight, name, CAS registry number, compound types, compound uses including healthy benefits, reference literatures, NMR, MS data, and the corresponding ID from databases such as HMDB and Pubmed. Users can also contribute novel regulatory entries by using a web-based submission page. The TMDB database is freely accessible from the URL of http://pcsb.ahau.edu.cn:8080/TCDB/index.jsp. The TMDB is designed to address the broad needs of tea biochemists, natural products chemists, nutritionists, and members of tea related research community. The TMDB database provides a solid platform for collection, standardization, and searching of compounds information found in tea. As such this database will be a comprehensive repository for tea biochemistry and tea health research community.

The status of ABWR-II development

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

Hiroyuki, Okada; Hideya Kitamura; Kumiaki, Moriya

This paper reports on the current development status of the ABWR-II project, a next generation reactor design based on the ABWR. In the early 90's, a program to develop the next generation reactor for the 21. century was launched, at a time when the first ABWR was still under construction. At the initial stage of this project, development of a 'user friendly' plant design was the primary objective. Thus, the main focus was placed on selecting a design with features promoting ease of operation and maintenance. Meanwhile, the circumstances surrounding the Japanese nuclear power industry changed. The delay of FBRmore » development and the deregulation of the power generation market have significantly boosted the role of light water reactors, and accelerated the need to improve LWR economics. For these reasons, economic competitiveness became an overriding objective in the development of the ABWR-II, with no less importance placed on achieving the highest standards of safety. Several new features were adopted to enhance economic performance: 1700 MW electric output, large fuel bundles, simplified MSIV, large capacity SRV. An output of 1700 MWe was selected for compatibility with the Japanese power grid, and with consideration of current reactor pressure vessel manufacturing capability. Large fuel bundles will contribute to a shortened refueling outage period and a reduction of CRDs. For enhanced safety, the reference design implements a modified ECCS with four subdivision RHR, a diversified power source incorporating gas turbine generators (GTG), an advanced RCIC (ARCIC) and passive heat removal systems consisting of a passive containment cooling system (PCCS) and a passive reactor cooling system (PRCS). The modified ECCS configuration also enables on-line maintenance. While current reactors rely on complex accident management (AM) procedures, implemented by operators in the event of a serious accident, the ABWR-II incorporated severe accident countermeasures at the design stage, to eliminate the need of operator induced AM procedures. The ABWR-II represents one of the most promising and reliable options for the future replacement of older units, without incurring excessive R and D costs. (authors)« less

[Research and development on efficacy of Chinese herbal compound].

PubMed

Liu, Jian-Xun; Ren, Jian-Xun; Lin, Cheng-Ren

2016-03-01

The efficacy not only is summarized by clinical effect of Chinese herbal compound on theory of traditional Chinese medicine, but also is manifested to clinical effect by interaction of many intricate chemical substances. The efficacy of Chinese herbal compound is current research focus in field of traditional Chinese medicine. By currently knowing in different aspects which included the progression in efficacy of Chinese herbal compound, symptomatic efficacy of Chinese herbal compound, the relationship between the efficacy and pharmacologic effect of Chinese herbal compound, the efficacy related pharmacodynamic substance and the evaluation of efficacy, it had been summarized mainly problems and methods in research and development process of the efficacy of Chinese herbal compound in this paper. Paper also elucidated problems that need to pay attention in research of efficacy in order to provide references for clinical and experimental studies of efficacy in Chinese herbal compound, boost research and development level of new traditional Chinese drug and facilitate modernization of traditional Chinese medicines. Copyright© by the Chinese Pharmaceutical Association.

Flavonoid Constituents of Phlomis (Lamiaceae) Species Using Liquid Chromatography Mass Spectrometry.

PubMed

Aghakhani, Fatemeh; Kharazian, Navaz; Lori Gooini, Zahra

2018-03-01

Phlomis is one of the medicinal genera of Lamiaceae. This genus has unique medicinal properties. Consequently, appropriate methods need to be described for the identification of the chemical compounds. A liquid chromatography tandem mass spectrometry (LC-MS/MS) technique on a triple quadrupole mass spectrometer (TQMS) was used for separation and identification of leaf flavonoid compounds for seven Phlomis species including Phlomis kurdia, Ph. aucheri, Ph. olivieri, Ph. bruguieri, Ph. persica, Ph. anisodonta and Ph. elliptica. The flavonoid solution of air-dried leaves (10.5 g) was extracted using 85% methanol. The chromatogram was treated with three systems: methanol-water, chloroform-methanol and acetic acid. The extracts were analysed using LC-MS/MS. The MS 2 detection was performed under negative mode electrospray ionisation (ESI). The identification of constituents was based on authentic references used in the identification process. A total of 35 chemical compounds were detected from which 32 were identified as flavonoids through comparison with published literature and reference standards. These compounds were distributed in four flavonoid classes. Flavones (12), flavonols (11), flavanones (8) and flavane (1) were the main groups appearing in almost all of the studied samples. The flavonoids such as naringenin, chrysoeriol, eriodictyol, dimethoxyflavanone, apigenin, luteolin, kaempferol and rhamnetin were in high proportions. Moreover, 22 flavonoid compounds were first reported in this study for Phlomis species. The fragmentation patterns of the compounds during collision induced dissociation (CID) clarified information of the compounds analysed. The detailed flavonoid compositions of Phlomis species provide the appropriate context from phytochemical and phytotherapeutics points of view. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

A Comprehensive Characterisation of Rosemary tea Obtained from Rosmarinus officinalis L. Collected in a sub-Humid Area of Tunisia.

PubMed

Achour, Mariem; Mateos, Raquel; Ben Fredj, Maha; Mtiraoui, Ali; Bravo, Laura; Saguem, Saad

2018-01-01

Rosemary (Rosmarinus officinalis L.) is an aromatic plant common in Tunisia and it is widely consumed as a tea in traditional cuisine and in folk medicine to treat various illnesses. Currently, most research efforts have been focused on rosemary essential oil, alcoholic and aqueous extracts, however, little is reported on rosemary infusion composition. To investigate compounds present in rosemary tea obtained from Rosmarinus officinalis L. collected in a sub-humid area of Tunisia in order to assess whether the traditional rosemary tea preparation method could be considered as a reference method for rosemary's compounds extraction. Qualitative characterisation of Rosmarinus officinalis tea obtained after rosemary infusion in boiled water was determined by high performance liquid chromatography coupled with electrospray ionisation quadrupole time-of-flight mass spectrometry (HPLC-ESI-QTOF-MS). Quantitative analysis relies on high performance liquid chromatography with diode array detector (HPLC-DAD). Forty-nine compounds belonging to six families, namely flavonoids, phenolic acids, phenolic terpenes, jasmonate, phenolic glycosides, and lignans were identified. To the best of the authors' knowledge eucommin A is characterised for the first time in rosemary. Rosmarinic acid (158.13 μg/g dried rosemary) was the main compound followed then by feruloylnepitrin (100.87 μg/g) and luteolin-3'-O-(2″-O-acetyl)-β-d-glucuronide (44.04 μg/g). Among quantified compounds, luteolin-7-O-rutinoside was the compound with the lowest concentration. The infusion method allows several polyphenols present in rosemary tea to be extracted, therefore it could be a reference method for rosemary's compounds extraction. Moreover, traditional Tunisian Rosmarinus officinalis tea consumption is of interest for its rich phenolic content. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

Functional Group Analysis.

ERIC Educational Resources Information Center

Smith, Walter T., Jr.; Patterson, John M.

1980-01-01

Discusses analytical methods selected from current research articles. Groups information by topics of general interest, including acids, aldehydes and ketones, nitro compounds, phenols, and thiols. Cites 97 references. (CS)

A literature survey of information on well installation and sample collection procedures used in investigations of ground-water contamination by organic compounds

USGS Publications Warehouse

Dumouchelle, D.H.; Lynch, E.A.; Cummings, T.R.

1990-01-01

A survey of literature on well installation and water-quality sampling, particularly as they relate to investigations of ground-water contamination by organic compounds, has been conducted. Library card files and computerized data bases were searched to identify journal articles, conference proceedings, technical reports, books, and other publications. Pertinent information has been extracted from 105 references; each reference is listed in a bibliography. Material contained in the report is organized by topical categories that include drilling methods and equipment, well construction, well development, sampling materials and equipment, decontamination of equipment, and sampling techniques and procedures. Unpublished data of the U.S. Geological Survey on sample collection are briefly cited also.

Structural characterization and antimicrobial activities of transition metal complexes of a hydrazone ligand

NASA Astrophysics Data System (ADS)

Bakale, Raghavendra P.; Naik, Ganesh N.; Machakanur, Shrinath S.; Mangannavar, Chandrashekhar V.; Muchchandi, Iranna S.; Gudasi, Kalagouda B.

2018-02-01

A hydrazone ligand has been synthesized by the condensation of 2-nitrobenzaldehyde and hydralazine, and its Co(II), Ni(II), Cu(II) and Zn(II) complexes have been reported. Structural characterization of the ligand and its metal complexes has been performed by various spectroscopic [IR, NMR, UV-Vis, Mass], thermal and other physicochemical methods. The structure of the ligand and its Ni(II) complex has been characterized by single crystal X-ray diffraction studies. All the synthesized compounds have been screened for in vitro antimicrobial activity. The antibacterial activity is tested against Gram-positive strains Enterococcus faecalis, Streptococcus mutans and Staphylococcus aureus and Gram-negative strains Escherichia coli, Pseudomonas aeruginosa and Klebsiella pneumoniae using ciprofloxacin as the reference standard. Antifungal activity is tested against Candida albicans, Aspergillus fumigatus and Aspergillus niger using ketoconazole as the reference standard. The minimum inhibitory concentration (MIC) was determined for test compounds as well as for reference standard. Ligand, Cu(II) and Zn(II) complexes have shown excellent activity against Candida albicans.

Kinetics and mechanisms of some atomic oxygen reactions

NASA Technical Reports Server (NTRS)

Cvetanovic, R. J.

1987-01-01

Mechanisms and kinetics of some reactions of the ground state of oxygen atoms, O(3P), are briefly summarized. Attention is given to reactions of oxygen atoms with several different types of organic and inorganic compounds such as alkanes, alkenes, alkynes, aromatics, and some oxygen, nitrogen, halogen and sulfur derivatives of these compounds. References to some recent compilations and critical evaluations of reaction rate constants are given.

Natural Products Research in China From 2015 to 2016

PubMed Central

Liu, Haishan; Zhu, Guoliang; Fan, Yaqin; Du, Yuqi; Lan, Mengmeng; Xu, Yibo; Zhu, Weiming

2018-01-01

This review covers the literature published by chemists from China during the 2015–2016 on natural products (NPs), with 1,985 citations referring to 6,944 new compounds isolated from marine or terrestrial microorganisms, plants, and animals. The emphasis is on 730 new compounds with a novel skeleton or/and significant bioactivity, together with their source organism and country of origin. PMID:29616210

Synthesis of structurally diverse benzosuberene analogues and their biological evaluation as anti-cancer agents

PubMed Central

Tanpure, Rajendra P.; George, Clinton S.; Strecker, Tracy E.; Devkota, Laxman; Tidmore, Justin K.; Lin, Chen-Ming; Herdman, Christine A.; MacDonough, Matthew T.; Sriram, Madhavi; Chaplin, David J.; Trawick, Mary Lynn; Pinney, Kevin G.

2014-01-01

Diversely functionalized, fused aryl-alkyl ring systems hold a prominent position as well-established molecular frameworks for a variety of anti-cancer agents. The benzosuberene (6,7 fused, also referred to as dihydro-5H-benzo[7]annulene and benzocycloheptene) ring system has emerged as a valuable molecular core component for the development of inhibitors of tubulin assembly, which function as antiproliferative anti-cancer agents and, in certain cases, as vascular disrupting agents (VDAs). Both a phenolic-based analogue (known as KGP18, compound 39) and its corresponding amine-based congener (referred to as KGP156, compound 45), which demonstrate strong inhibition of tubulin assembly (low micromolar range) and potent cytotoxicity (picomolar range for KGP18 and nanomolar range for KGP156) are noteworthy examples of such benzosuberene-based compounds. In order to extend the structure-activity relationship (SAR) knowledge base related to benzosuberene anti-cancer agents, a series of eleven analogues (including KGP18) were prepared in which the methoxylation pattern on the pendant aryl ring as well as functional group incorporation on the fused aryl ring were varied. The synthetic approach to these compounds featured a sequential Wittig olefination, reduction, Eaton's reagent-mediated cyclization strategy to achieve the core benzosuberone intermediate, and represented a higher-yielding synthesis of KGP18 (which we prepared previously through a ring-expansion strategy). Incorporation of a fluorine or chlorine atom at the 1-position of the fused aryl ring or replacement of one of the methoxy groups with hydrogen (on the pendant aryl ring of KGP18) led to benzosuberene analogues that were both strongly inhibitory against tubulin assembly (IC50 approximately 1.0 M) and strongly cytotoxic against selected human cancer cell lines (for example, GI50 = 5.47 nM against NCI-H460 cells with fluorobenzosuberene analogue 37). A water-soluble phosphate prodrug salt of KGP18 (referred to as KGP265, compound 44) and a water-soluble serinamide salt (compound 48) of KGP156 were also synthesized and evaluated in this study. PMID:24183586

Chapter 3. Determination of semivolatile organic compounds and polycyclic aromatic hydrocarbons in solids by gas chromatography/mass spectrometry

USGS Publications Warehouse

Zaugg, Steven D.; Burkhardt, Mark R.; Burbank, Teresa L.; Olson, Mary C.; Iverson, Jana L.; Schroeder, Michael P.

2006-01-01

A method for the determination of 38 polycyclic aromatic hydrocarbons (PAHs) and semivolatile organic compounds in solid samples is described. Samples are extracted using a pressurized solvent extraction system. The compounds of interest are extracted from the solid sample twice at 13,800 kilopascals; first at 120 degrees Celsius using a water/isopropyl alcohol mixture (50:50, volume-to-volume ratio), and then the sample is extracted at 200 degrees Celsius using a water/isopropyl alcohol mixture (80:20, volume-to-volume ratio). The compounds are isolated using disposable solid-phase extraction (SPE) cartridges containing divinylbenzene-vinylpyrrolidone copolymer resin. The cartridges are dried with nitrogen gas, and then sorbed compounds are eluted from the SPE material using a dichloromethane/diethyl ether mixture (80:20, volume-to-volume ratio) and passed through a sodium sulfate/Florisil SPE cartridge to remove residual water and to further clean up the extract. The concentrated extract is solvent exchanged into ethyl acetate and the solvent volume reduced to 0.5 milliliter. Internal standard compounds are added prior to analysis by capillary-column gas chromatography/mass spectrometry. Comparisons of PAH data for 28 sediment samples extracted by Soxhlet and the accelerated solvent extraction (ASE) method described in this report produced similar results. Extraction of PAH compounds from standard reference material using this method also compared favorably with Soxhlet extraction. The recoveries of PAHs less than molecular weight 202 (pyrene or fluoranthene) are higher by up to 20 percent using this ASE method, whereas the recoveries of PAHs greater than or equal to molecular weight 202 are equivalent. This ASE method of sample extraction of solids has advantages over conventional Soxhlet extraction by increasing automation of the extraction process, reducing extraction time, and using less solvent. Extract cleanup also is greatly simplified because SPE replaces commonly used gel permeation chromatography. The performance of the method (as expressed by mean recoveries and mean precision) was determined using Ottawa sand, a commercially available topsoil, and an environmental stream sediment, fortified at 1.5 and 15 micrograms per compound. Recoveries of PAH and semivolatile compounds in Ottawa sand samples fortified at 1.5 micrograms averaged 88 percent ? 9.4 percent relative standard deviation, and calculated initial method detection limits per compound averaged 14 micrograms per kilogram, assuming a 25-gram sample size. The recovery for 1,2,4-trichlorobenzene is less than 60 percent; thus, the concentration of this compound will always be reported as estimated with the E remark code. The analysis of 25 alkylated PAH homolog groups also can be determined with this method with extra data analysis and review, but because of the lack of authentic reference standard compounds, these results are considered to be semiquantitative. The PAH homolog groups are quantitated using the response factor of a parent PAH method compound, if available. Precision data for the alkylated PAH homologs detected in a marine sediment standard reference material (SRM 1944) also are presented to document and demonstrate method capability.

Synthesis of 4-substituted pyrido[2,3-d]pyrimidin-4(1H)-one as analgesic and anti-inflammatory agents.

PubMed

El-Gazzar, Abdel-Rahman B A; Hafez, Hend N

2009-07-01

4-Substituted-pyrido[2,3-d]pyrimidin-4(1H)-ones 4a-c were synthesized by oxidation of 4-substituted-dihydropyrido[2,3-d]pyrimidin-4(1H)-ones 3a-c which were in turn prepared from arylidenemalononitriles 1a-c and 6-aminothiouracil 2. The reactivity of compounds 4a-c towards some reagents such as formamide, carbon disulfide, urea, thiourea, formic and acetic acids were studied. All the synthesized compounds were characterized by spectroscopic means and elemental analysis. Compound 4c exhibited 64% and 72% analgesic activity. Also, compound 4b showed 50% and 65% anti-inflammatory activity. Interestingly these compounds showed one-third of ulcer index of the reference aspirin and diclofenac.

Phosphorus-containing nucleophiles in reactions with polyfluorinated organic compounds

NASA Astrophysics Data System (ADS)

Furin, Georgii G.

1993-03-01

The review presents a compilation of new expelimental data on the reactions of phosphorus-containing nucleophiles [triphenylphosphine, trialkylphosphines, trialkyl phosphites, phosphorus tris(diethylamide), etc.] with perfluorinated olefins and aromatic and heterocyclic compounds, leading to substances both with and without a phosphorus atom. It is shown that the interaction of phosphorus tris(diethylamide) and trialkylphosphines with organic polyfluoro-compounds and perfluoroolefins leads to the formation of phosphoranes, the decomposition of which is accompanied by the generation of aryl and alkenyl anions. The reactions of these anions with C-electrophiles and compounds containing mobile halogen atoms are examined. In addition, the pathways in the Arbuzov reaction involving a series of unsaturated perfluorinated compounds are analysed. Possible applications of these reactions in organic synthesis are demonstrated. The bibliography includes 120 references.

40 CFR 60.221 - Definitions.

Code of Federal Regulations, 2014 CFR

2014-07-01

... PERFORMANCE FOR NEW STATIONARY SOURCES Standards of Performance for the Phosphate Fertilizer Industry... ammonia. (b) Total fluorides means elemental fluorine and all fluoride compounds as measured by reference...

40 CFR 60.221 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-07-01

... PERFORMANCE FOR NEW STATIONARY SOURCES Standards of Performance for the Phosphate Fertilizer Industry... ammonia. (b) Total fluorides means elemental fluorine and all fluoride compounds as measured by reference...

40 CFR 60.221 - Definitions.

Code of Federal Regulations, 2013 CFR

2013-07-01

... PERFORMANCE FOR NEW STATIONARY SOURCES Standards of Performance for the Phosphate Fertilizer Industry... ammonia. (b) Total fluorides means elemental fluorine and all fluoride compounds as measured by reference...

40 CFR 60.221 - Definitions.

Code of Federal Regulations, 2012 CFR

2012-07-01

... PERFORMANCE FOR NEW STATIONARY SOURCES Standards of Performance for the Phosphate Fertilizer Industry... ammonia. (b) Total fluorides means elemental fluorine and all fluoride compounds as measured by reference...

40 CFR 60.221 - Definitions.

Code of Federal Regulations, 2011 CFR

2011-07-01

... PERFORMANCE FOR NEW STATIONARY SOURCES Standards of Performance for the Phosphate Fertilizer Industry... ammonia. (b) Total fluorides means elemental fluorine and all fluoride compounds as measured by reference...

Identification, characterization and quantitation of pyrogenic polycylic aromatic hydrocarbons and other organic compounds in tire fire products.

PubMed

Wang, Zhendi; Li, K; Lambert, P; Yang, Chun

2007-01-12

On 15 August 2001, a tire fire took place at the Pneu Lavoie Facility in Gatineau, Quebec, in which 4000 to 6000 new and recycled tires were stored along with other potentially hazardous materials. Comprehensive gas chromatography-mass spectrometry (GC-MS) analyses were performed on the tire fire samples to facilitate detailed chemical composition characterization of toxic polycyclic aromatic hydrocarbons (PAHs) and other organic compounds in samples. It is found that significant amounts of PAHs, particularly the high-ring-number PAHs, were generated during the fire. In total, 165 PAH compounds including 13 isomers of molecular weight (MW) 302, 10 isomers of MW 278, 10 isomers of MW 276, 7 isomers of MW 252, 7 isomers of MW 228, and 8 isomers of MW 216 PAHs were positively identified in the tire fire wipe samples for the first time. Numerous S-, O-, and N-containing PAH compounds were also detected. The identification and characterization of the PAH isomers was mainly based on: (1) a positive match of mass spectral data of the PAH isomers with the NIST authentic mass spectra database; (2) a positive match of the GC retention indices (I) of PAHs with authentic standards and with those reported in the literature; (3) agreement of the PAH elution order with the NIST (US National Institute of Standards and Technology) Standard Reference Material 1597 for complex mixture of PAHs from coal tar; (4) a positive match of the distribution patterns of PAH isomers in the SIM mode between the tire fire samples and the NIST Standard Reference Materials and well-characterized reference oils. Quantitation of target PAHs was done on the GC-MS in the selected ion monitoring (SIM) mode using the internal standard method. The relative response factors (RRF) for target PAHs were obtained from analyses of authentic PAH standard compounds. Alkylated PAH homologues were quantitated using straight baseline integration of each level of alkylation.

Chemosensors for detection of nitroaromatic compounds (explosives)

NASA Astrophysics Data System (ADS)

Zyryanov, G. V.; Kopchuk, D. S.; Kovalev, I. S.; Nosova, E. V.; Rusinov, V. L.; Chupakhin, O. N.

2014-09-01

The key types of low-molecular-mass chemosensors for the detection of nitroaromatic compounds representing energetic substances (explosives) are analyzed. The coordination and chemical properties of these chemosensors and structural features of their complexes with nitroaromatic compounds are considered. The causes and methods for attaining high selectivity of recognition are demonstrated. The primary attention is paid to the use of low-molecular-mass chemosensors for visual detection of explosives of this class by colorimetric and photometric methods. Examples of using photo- and chemiluminescence for this purpose are described. A separate section is devoted to electrochemical methods of detection of nitroaromatic compounds. Data published from 2000 to 2014 are mainly covered. The bibliography includes 245 references.

Development of Eddy Current Techniques for the Detection of Cracking in Space Shuttle Primary Reaction Control Thrusters

NASA Technical Reports Server (NTRS)

Wincheski, Buzz A.; Simpson, John W.; Koshti, Ajay

2007-01-01

A recent identification of cracking in the Space Shuttle Primary Reaction Control System (PRCS) thrusters triggered an extensive nondestructive evaluation effort to develop techniques capable of identifying such damage on installed shuttle hardware. As a part of this effort, specially designed eddy current probes inserted into the acoustic cavity were explored for the detection of such flaws and for evaluation of the remaining material between the crack tip and acoustic cavity. The technique utilizes two orthogonal eddy current probes which are scanned under stepper motor control in the acoustic cavity to identify cracks hidden with as much as 0.060 remaining wall thickness to the cavity. As crack growth rates in this area have been determined to be very slow, such an inspection provides a large safety margin for continued operation of the critical shuttle hardware. Testing has been performed on thruster components with both actual and fabricated defects. This paper will review the design and performance of the developed eddy current inspection system. Detection of flaws as a function of remaining wall thickness will be presented along with the proposed system configuration for depot level or on-vehicle inspection capabilities.

Development of Eddy Current Technique for the Detection of Stress Corrosion Cracking in Space Shuttle Primary Reaction Control Thrusters

NASA Technical Reports Server (NTRS)

Wincheski, Buzz; Simpson, John; Koshti, Ajay

2006-01-01

A recent identification of stress corrosion cracking in the Space Shuttle Primary Reaction Control System (PRCS) thrusters triggered an extensive nondestructive evaluation effort to develop techniques capable of identifying such damage on installed shuttle hardware. As a part of this effort, specially designed eddy current probes inserted into the acoustic cavity were explored for the detection of such flaws and for evaluation of the remaining material between the crack tip and acoustic cavity. The technique utilizes two orthogonal eddy current probes which are scanned under stepper motor control in the acoustic cavity to identify cracks hidden with as much as 0.060 remaining wall thickness to the cavity. As crack growth rates in this area have been determined to be very slow, such an inspection provides a large safety margin for continued operation of the critical shuttle hardware. Testing has been performed on thruster components with both actual and fabricated defects. This paper will review the design and performance of the developed eddy current inspection system. Detection of flaws as a function of remaining wall thickness will be presented along with the proposed system configuration for depot level or on-vehicle inspection capabilities.

SRMS Assisted Docking and Undocking for the Orbiter Repair Maneuver

NASA Technical Reports Server (NTRS)

Quiocho, Leslie J.; Briscoe, Timothy J.; Schliesing, John A.; Braman, Julia M.

2005-01-01

As part of the Orbiter Repair Maneuver (ORM) planned for Return to Flight (RTF) operations, the Shuttle Remote Manipulator System (SRMS) must undock the Orbiter, maneuver it through a complex trajectory at extremely low rates, present it to an EVA crewman at the end of the Space Station Remote Manipulator System to perform the Thermal Protection System (TPS) repair, and then retrace back through the trajectory to dock the Orbiter with the Orbiter Docking System (ODs). The initial and final segments of this operation involve the interaction between the SRMS, ISS, Orbiter and ODs. This paper first provides an overview of the Monte-Carlo screening analysis for the installation (both nominal and contingency), including the variation of separation distance, misalignment conditions, SRMS joint/brake parameter characteristics, and PRCS jet combinations and corresponding thrust durations. The resulting 'optimum' solution is presented based on trade studies between predicted capture success and integrated system loads. This paper then discusses the upgrades to the APAS math model associated with the new SRMS assisted undocking technique and reviews simulation results for various options investigated for either the active and passive separation of the ISS from the Orbiter.

Estimation of the phase response curve from Parkinsonian tremor.

PubMed

Saifee, Tabish A; Edwards, Mark J; Kassavetis, Panagiotis; Gilbertson, Tom

2016-01-01

Phase response curves (PRCs), characterizing the response of an oscillator to weak external perturbation, have been estimated from a broad range of biological oscillators, including single neurons in vivo. PRC estimates, in turn, provide an intuitive insight into how oscillatory systems become entrained and how they can be desynchronized. Here, we explore the application of PRC theory to the case of Parkinsonian tremor. Initial attempts to establish a causal effect of subthreshold transcranial magnetic stimulation applied to primary motor cortex on the filtered tremor phase were unsuccessful. We explored the possible explanations of this and demonstrate that assumptions made when estimating the PRC in a traditional setting, such as a single neuron, are not arbitrary when applied to the case of tremor PRC estimation. We go on to extract the PRC of Parkinsonian tremor using an iterative method that requires varying the definition of the tremor cycle and estimating the PRC at multiple peristimulus time samples. Justification for this method is supported by estimates of PRC from simulated single neuron data. We provide an approach to estimating confidence limits for tremor PRC and discuss the interpretational caveats introduced by tremor harmonics and the intrinsic variability of the tremor's period. Copyright © 2016 the American Physiological Society.

Estimation of the phase response curve from Parkinsonian tremor

PubMed Central

Saifee, Tabish A.; Edwards, Mark J.; Kassavetis, Panagiotis

2015-01-01

Phase response curves (PRCs), characterizing the response of an oscillator to weak external perturbation, have been estimated from a broad range of biological oscillators, including single neurons in vivo. PRC estimates, in turn, provide an intuitive insight into how oscillatory systems become entrained and how they can be desynchronized. Here, we explore the application of PRC theory to the case of Parkinsonian tremor. Initial attempts to establish a causal effect of subthreshold transcranial magnetic stimulation applied to primary motor cortex on the filtered tremor phase were unsuccessful. We explored the possible explanations of this and demonstrate that assumptions made when estimating the PRC in a traditional setting, such as a single neuron, are not arbitrary when applied to the case of tremor PRC estimation. We go on to extract the PRC of Parkinsonian tremor using an iterative method that requires varying the definition of the tremor cycle and estimating the PRC at multiple peristimulus time samples. Justification for this method is supported by estimates of PRC from simulated single neuron data. We provide an approach to estimating confidence limits for tremor PRC and discuss the interpretational caveats introduced by tremor harmonics and the intrinsic variability of the tremor's period. PMID:26561596

Microwave-Assisted Synthesis of some Novel Azoles and Azolopyrimidines as Antimicrobial Agents.

PubMed

Gomha, Sobhi M; Farghaly, Thoraya A; Mabkhot, Yahia Nasser; Zayed, Mohie E M; Mohamed, Amany M G

2017-02-23

In this study, new derivatives of pyrazole, isoxazole, pyrazolylthiazole, and azolopyrimidine having a thiophene ring were synthesized under microwave irradiation. Their pharmacological activity toward bacteria and fungi inhibition was screened and compared to the references Chloramphenicol and Trimethoprim / sulphamethoxazole . The antimicrobial results of the investigated compounds revealed promising results and some derivatives have activities similar to the references used.

Chemistry, Characterization and Processing of IMC Curing Polymers.

DTIC Science & Technology

1983-07-01

example, nitronium hexafluorosilicate (Ref- erence 110), nitronium hexafluorophosphate (Reference 111) and nitronium trifluorometh- anesulfonate(triflate...CCLtoo) "C The dilithio compound underwent lithium -halogen exchange instead of displacement with bromophenylacetylene (Reference 129) due to the...positive character of the bromine on l-bromo-2-phenylacetylene. The reaction product of the lithium -bromine exchange reaction ൭ was identified as 1,4

Computational Prediction of Electron Ionization Mass Spectra to Assist in GC/MS Compound Identification.

PubMed

Allen, Felicity; Pon, Allison; Greiner, Russ; Wishart, David

2016-08-02

We describe a tool, competitive fragmentation modeling for electron ionization (CFM-EI) that, given a chemical structure (e.g., in SMILES or InChI format), computationally predicts an electron ionization mass spectrum (EI-MS) (i.e., the type of mass spectrum commonly generated by gas chromatography mass spectrometry). The predicted spectra produced by this tool can be used for putative compound identification, complementing measured spectra in reference databases by expanding the range of compounds able to be considered when availability of measured spectra is limited. The tool extends CFM-ESI, a recently developed method for computational prediction of electrospray tandem mass spectra (ESI-MS/MS), but unlike CFM-ESI, CFM-EI can handle odd-electron ions and isotopes and incorporates an artificial neural network. Tests on EI-MS data from the NIST database demonstrate that CFM-EI is able to model fragmentation likelihoods in low-resolution EI-MS data, producing predicted spectra whose dot product scores are significantly better than full enumeration "bar-code" spectra. CFM-EI also outperformed previously reported results for MetFrag, MOLGEN-MS, and Mass Frontier on one compound identification task. It also outperformed MetFrag in a range of other compound identification tasks involving a much larger data set, containing both derivatized and nonderivatized compounds. While replicate EI-MS measurements of chemical standards are still a more accurate point of comparison, CFM-EI's predictions provide a much-needed alternative when no reference standard is available for measurement. CFM-EI is available at https://sourceforge.net/projects/cfm-id/ for download and http://cfmid.wishartlab.com as a web service.

Characterization of fumonisin A-series by high-resolution liquid chromatography-orbitrap mass spectrometry.

PubMed

Tamura, Masayoshi; Mochizuki, Naoki; Nagatomi, Yasushi; Toriba, Akira; Hayakawa, Kazuichi

2014-08-21

Fumonisin A-series (FAs) in a reference material of corn sample that was naturally contaminated with fumonisins was characterized using high-resolution liquid chromatography-Orbitrap mass spectrometry (LC-Orbitap MS). Peaks for fumonisin B1 (FB1), fumonisin B2 (FB2), and fumonisin B3 (FB3), in addition to three peaks corresponding to unknown compounds I, II, and III, were detected in the chromatogram for the corn sample. Fragment ion analysis for FB1, FB2, and FB3 showed that while the ions formed at m/z values of 200-800 were similar to those formed by the cleavage of the tricarballylic acids and the hydroxyl groups, the fragmentation patterns at m/z values of 50-200 varied depending on the hydroxyl group locations in the compounds. Fragment ion analysis of compounds I-III revealed structural similarities to FBs, only differing by an additional C2H2O in the unknown compounds. Using these results and by comparing the product ion mass spectra of compound I with fumonisin A1 (FA1) synthesized from FB1 standards, compounds I-III were hypothesized to be N-acetyl analogs of FBs: fumonisins A1 (FA1), A2 (FA2), and A3 (FA3). The method for determining concentrations was validated with FA1, FB1, FB2, and FB3 standards and applied to analyze the reference material. The FB1, FB2, and FB3 analytical levels were within acceptance limits and the amount of FA1 in the material was ~15% of FB1 amount at 4.2 mg/kg.

Synthesis and antimalarial activity study of some new Mannich bases of 7-chloro-4-aminoquinoline.

PubMed

Roy, Susanta; Chetia, Dipak; Rudrapal, Mithun; Prakash, Anil

2013-05-01

New derivatives of 7-chloro-4-aminoquinoline Mannich base were prepared by selectively modifying the aliphatic diethyl amino function of isoquine with different aliphatic/aromatic heterocyclic primary amino moieties at Mannich side chain. The synthesized compounds were characterized by their analytical and spectral data, and screened for in-vitro antimalarial activity against a chloroquine-sensitive 3D7 strain of Plasmodium falciparum. All the compounds showed in-vitro antimalarial activity at the tested dose; which, however, was considerably less than that of the standard reference drug, chloroquine. Among synthesized compounds, compounds with cyclohexyl (2f), methyl (2c) substitutions showed better activity than compounds substituted with n-octyl (2a), propyl (2b), 3-aminopropyl (2d) and furan-2- ylmethyl (2e) moieties at aminomethyl side chain. The results clearly demonstrate that the compound substituted with saturated cycloalkyl moiety (cyclohexyl) exhibited to some extent increased activity as compared to the compound containing heterocyclic moiety (furan-2-ylmethyl), and compounds with short chain alkyl substitutions (methyl, propyl) were found to be more active than that of compounds with long chain alkyl substitution (n-octyl).

Antimicrobial and antioxidant activities of triterpenoid and phenolic derivatives from two Cameroonian Melastomataceae plants: Dissotis senegambiensis and Amphiblemma monticola.

PubMed

Nzogong, Raissa Tioyem; Ndjateu, Fabrice Sterling Tchantchou; Ekom, Steve Endeguele; Fosso, Jules-Arnaud Mboutchom; Awouafack, Maurice Ducret; Tene, Mathieu; Tane, Pierre; Morita, Hiroyuki; Choudhary, Muhammad Iqbal; Tamokou, Jean-de-Dieu

2018-05-16

Antimicrobial resistance is a serious threat against humankind and the search for new therapeutics is needed. This study aims to investigate the antimicrobial and antioxidant activities of ethanol extracts and compounds isolated from Dissotis senegambiensis and Amphiblemma monticola, two Cameroonian Melastomataceae species traditionally used for the treatment of fever, malaria and infectious diseases. The plant extracts were prepared by maceration in ethanol. Standard chromatographic and spectroscopic methods were used to isolate and identify fourteen compounds from the two plant species [1-6 (from D. senegambiensis), 3, 4 and 7-14 (from A. monticola)]. A two-fold serial micro-dilution method was used to determine the minimum inhibitory concentration (MIC) against four bacterial strains including two resistant bacterial strains, methicillin resistant S. aureus (MRSA3) and methicillin resistant S. aureus (MRSA4) and three yeast strains. The fractionation of EtOH extracts afforded fourteen compounds belonging to triterpenoid and phenolic derivatives. The ethanol extracts, compounds 3, 5-8, 10 and the mixture of 10 + 12 were active against all the tested bacterial and fungal species. Compound 7 (MIC = 16-32 μg/mL) and 10 (MIC = 8-16 μg/mL) displayed the largest antibacterial and antifungal activities, respectively. Compounds 7, 10 and the mixture of 10 + 12 showed prominent antibacterial activity against methicillin- resistant S. aureus (MRSA) which is in some cases equal to that of ciprofloxacin used as reference antibacterial drug. Compound 8 also showed high radical-scavenging activities and ferric reducing power when compared with vitamin C and butylated hydroxytoluene used as reference antioxidants. The tested samples were non-toxic to normal cells highlighting their good selectivity. The result of this investigation reveals the potential of D. senegambiensis and A. monticola as well as the most active compounds in the search for new antimicrobial and antioxidant agents. So, further investigations are needed.

New quinoline derivatives demonstrate a promising antimalarial activity against Plasmodium falciparum in vitro and Plasmodium berghei in vivo.

PubMed

Soares, Roberta Reis; da Silva, José Marcio Fernandes; Carlos, Bianca Cecheto; da Fonseca, Camila Campos; de Souza, Laila Salomé Araújo; Lopes, Fernanda Valério; de Paula Dias, Rafael Mafra; Moreira, Paulo Otávio Lourenço; Abramo, Clarice; Viana, Gustavo Henrique Ribeiro; de Pila Varotti, Fernando; da Silva, Adilson David; Scopel, Kézia Katiani Gorza

2015-06-01

Malaria continues to be an important public health problem in the world. Nowadays, the widespread parasite resistance to many drugs used in antimalarial therapy has made the effective treatment of cases and control of the disease a constant challenge. Therefore, the discovery of new molecules with good antimalarial activity and tolerance to human use can be really important in the further treatment of the disease. In this study we have investigated the antiplasmodial activity of 10 synthetic compounds derived from quinoline, five of them combined to sulfonamide and five to the hydrazine or hydrazide group. The compounds were evaluated according to their cytotoxicity against HepG2 and HeLa cell lines, their antimalarial activity against CQ-sensitive and CQ-resistant Plasmodium falciparum strains and, finally, their schizonticide blood action in mice infected with Plasmodium berghei NK65. The compounds exhibited no cytotoxic action in HepG2 and HeLa cell lines when tested up to a concentration of 100 μg/mL. In addition, the hydrazine or hydrazide derivative compounds were less cytotoxic against cell lines and more active against CQ-sensitive and CQ-resistant P. falciparum strains, showing high SI (>1000 when SI was calculated using the CC50 from the 3D7 strain as reference). When tested in vivo, the hydrazine derivative 1f compound showed activity against the development of blood parasites similar to that observed with CQ, the reference drug. Interestingly, the 1f compound demonstrated the best LipE value (4.84) among all those tested in vivo. Considering the in vitro and in vivo activities of the compounds studied here and the LipE values, we believe the 1f compound to be the most promising molecule for further studies in antimalarial chemotherapy. Copyright © 2015 Elsevier Ltd. All rights reserved.

Isolation and Identification of Three γ-Glutamyl Tripeptides and Their Putative Production Mechanism in Aged Garlic Extract.

PubMed

Nakamoto, Masashi; Fujii, Takuto; Matsutomo, Toshiaki; Kodera, Yukihiro

2018-03-21

We analyzed aged garlic extract (AGE) to understand its complex sulfur chemistry using post-column high-performance liquid chromatography with an iodoplatinate reagent and liquid chromatography high resolution mass spectrometry (LC-MS). We observed unidentified peaks of putative sulfur compounds. Three compounds were isolated and identified as γ-glutamyl-γ-glutamyl- S-methylcysteine, γ-glutamyl-γ-glutamyl- S-allylcysteine (GGSAC) and γ-glutamyl-γ-glutamyl- S-1-propenyl-cysteine (GGS1PC) by nuclear magnetic resonance and LC-MS analysis based on comparisons with chemically synthesized reference compounds. GGSAC and GGS1PC were novel compounds. Trace amounts of these compounds were detected in raw garlic, but the contents of these compounds increased during the aging process. Production of these compounds was inhibited using a γ-glutamyl transpeptidase (GGT) inhibitor in the model reaction mixtures. These findings suggest that γ-glutamyl tripeptides in AGE are produced by GGT during the aging process.

Evaluation of Marijuana Compounds on Neuroimmune Endpoints in Experimental Autoimmune Encephalomyelitis.

PubMed

Kaplan, Barbara L F

2018-02-21

Cannabinoid compounds refer to a group of more than 60 plant-derived compounds in Cannabis sativa, more commonly known as marijuana. Exposure to marijuana and cannabinoid compounds has been increasing due to increased societal acceptance for both recreational and possible medical use. Cannabinoid compounds suppress immune function, and while this could compromise one's ability to fight infections, immune suppression is the desired effect for therapies for autoimmune diseases. It is critical, therefore, to understand the effects and mechanisms by which cannabinoid compounds alter immune function, especially immune responses induced in autoimmune disease. Therefore, this unit will describe induction and assessment of the experimental autoimmune encephalomyelitis (EAE) model of multiple sclerosis (MS), and its potential alteration by cannabinoid compounds. The unit includes three approaches to induce EAE, two of which provide correlations to two forms of MS, and the third specifically addresses the role of autoreactive T cells in EAE. © 2018 by John Wiley & Sons, Inc. Copyright © 2018 John Wiley & Sons, Inc.

Biological activity of some derivatives of β-cyclodextrin.

PubMed

Batalova, T A; Dorovskich, V A; Kurochkina, G I; Grachev, M K; Plastinin, M L; Sergievich, A A

2011-10-01

New compounds of β-cyclodextrin containing covalently bound (conjugated) residues of acetylsalicylic and 1-(4-isobutylphenyl)-propionic acids were synthesized in the reaction of chlorides of the corresponding acids with β-cyclodextrin. We studied antiplatelet and antiphlogistic properties of these substances. It was shown that new compounds are comparable and in some cases are superior to the reference drugs acetylsalicylic acid and ibuprofen by anti-inflammatory and antiaggregant activities.

Reaction mechanisms in cellulose pyrolysis: a literature review

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

Molton, P.M.; Demmitt, T.F.

1977-08-01

A bibliographic review of 195 references is presented outlining the history of the research into the mechanisms of cellulose pyrolysis. Topics discussed are: initial product identification, mechanism of initial formation of levoglucosan, from cellulose and from related compounds, decomposition of cellulose to other compounds, formation of aromatics, pyrolysis of levoglucosan, crosslinking of cellulose, pyrolytic reactions of cellulose derivatives, and the effects of inorganic salts on the pyrolysis mechanism. (JSR)

Ensemble docking to difficult targets in early-stage drug discovery: Methodology and application to fibroblast growth factor 23.

PubMed

Velazquez, Hector A; Riccardi, Demian; Xiao, Zhousheng; Quarles, Leigh Darryl; Yates, Charless Ryan; Baudry, Jerome; Smith, Jeremy C

2018-02-01

Ensemble docking is now commonly used in early-stage in silico drug discovery and can be used to attack difficult problems such as finding lead compounds which can disrupt protein-protein interactions. We give an example of this methodology here, as applied to fibroblast growth factor 23 (FGF23), a protein hormone that is responsible for regulating phosphate homeostasis. The first small-molecule antagonists of FGF23 were recently discovered by combining ensemble docking with extensive experimental target validation data (Science Signaling, 9, 2016, ra113). Here, we provide a detailed account of how ensemble-based high-throughput virtual screening was used to identify the antagonist compounds discovered in reference (Science Signaling, 9, 2016, ra113). Moreover, we perform further calculations, redocking those antagonist compounds identified in reference (Science Signaling, 9, 2016, ra113) that performed well on drug-likeness filters, to predict possible binding regions. These predicted binding modes are rescored with the molecular mechanics Poisson-Boltzmann surface area (MM/PBSA) approach to calculate the most likely binding site. Our findings suggest that the antagonist compounds antagonize FGF23 through the disruption of protein-protein interactions between FGF23 and fibroblast growth factor receptor (FGFR). © 2017 John Wiley & Sons A/S.

The electronic nose as a rapid sensor for volatile compounds in treated domestic wastewater.

PubMed

Dewettinck, T; Van Hege, K; Verstraete, W

2001-07-01

An electronic nose consisting of 12 metal oxide sensors was used to monitor volatile compounds in effluent of a domestic wastewater treatment plant. Effluent and reference (deionized water) samples were heated to 60 and 90 degrees C to promote the volatilization and to increase the sensitivity. An effluent measuring campaign of 12 weeks was conducted and the repeatability and reproducibility of the procedure and the apparatus were determined. Processing the obtained fingerprints with principal component analysis (PCA) allowed interpretation and differentiation of the samples in terms of origin and quality, relative to the reference. To minimize the variance due to sensitivity fluctuations of the apparatus and to detect effluents with deviating qualities, two new concepts were defined, i.e. the relative sensorial odour perception (in short: rSOP) and the relative fingerprint. Correlations between the relative overall electronic nose output, expressed as rSOP, and selected routine parameters were weak except for the parameter "volatile suspended solids" (VSS), indicating adsorption of volatile organic compounds (VOCs) onto the organic particles. The results clearly demonstrate the possibility to use the electronic nose as a rapid alarm generator towards volatile compounds, e.g. in specific advanced treatment processes to produce reclaimed water from effluent of the domestic wastewater treatment plant under scrutiny.

Devices for the Production of Reference Gas Mixtures.

PubMed

Fijało, Cyprian; Dymerski, Tomasz; Gębicki, Jacek; Namieśnik, Jacek

2016-09-02

For many years there has been growing demand for gaseous reference materials, which is connected with development in many fields of science and technology. As a result, new methodological and instrumental solutions appear that can be used for this purpose. Appropriate quality assurance/quality control (QA/QC) must be used to make sure that measurement data are a reliable source of information. Reference materials are a significant element of such systems. In the case of gas samples, such materials are generally called reference gas mixtures. This article presents the application and classification of reference gas mixtures, which are a specific type of reference materials, and the methods for obtaining them are described. Construction solutions of devices for the production of reference gas mixtures are detailed, and a description of a prototype device for dynamic production of reference gas mixtures containing aroma compounds is presented.

Synthesis and molecular docking of some novel anticancer sulfonamides carrying a biologically active pyrrole and pyrrolopyrimidine moieties.

PubMed

Ghorab, Mostafa M; Alsaid, Mansour S; Nissan, Yassin M

2014-01-01

Abstract: A novel series of pyrroles and pyrrolopyrimdines carrying a biologically active sulfonamide moiety have been synthesized. The structures were confirmed by elemental analyses and spectral data. All the target compounds were subjected to in vitro cytotoxic screening on breast cancer cell line (MCF-7). Most of the synthesized compounds showed good activity as cytotoxic agents with better IC50 than doxorubicin as a reference drug. In order to suggest a mechanism of action for their activity, molecular docking on the active site of human c-Src was performed for all synthesized compounds.

Quality Control: (Material) Safety Data Sheets.

PubMed

Allen, Loyd V

2017-01-01

Safety Data Sheets (formerly Material Safety Data Sheets) are a system for cataloging information on chemicals, chemical compounds, and chemical mixtures and include instructions for the safe use and potential hazards associated with a particular material or product. At present, there are 16 sections of Safety Data Sheets, and these sections are discussed in this article. Two United States Pharmacopeia compounding-related chapters (<795> and <800>) refer to Safety Data Sheets, and this article provides a brief discussion on the terminology contained within those chapters. Copyright© by International Journal of Pharmaceutical Compounding, Inc.

Hazard Assessment Computer System HACS/UIM Users’ Operation Manual. Volume I.

DTIC Science & Technology

1981-09-01

941999-A U NCL A SSI7IED USCG-D-75-AL R_1 3 ~hhE~ I EEmhh.EEohmhE 2 I 1.I25 1.fl4 L MICROCOP RtfSCLUTItN IEST HTAK ’I’l ONAL BURLAU OF STANDARDS-1963...to assist in obtaining the compound recognition code used to refer- ence data for a particular chemical, a separate set of indices have been produced...and are given in a separate report. These indices enable a user of HACS to obtain a compound recognition code for a chemical given either the compound

Chemical-specific screening criteria for interpretation of biomonitoring data for volatile organic compounds (VOCs)--application of steady-state PBPK model solutions.

PubMed

Aylward, Lesa L; Kirman, Chris R; Blount, Ben C; Hays, Sean M

2010-10-01

The National Health and Nutrition Examination Survey (NHANES) generates population-representative biomonitoring data for many chemicals including volatile organic compounds (VOCs) in blood. However, no health or risk-based screening values are available to evaluate these data from a health safety perspective or to use in prioritizing among chemicals for possible risk management actions. We gathered existing risk assessment-based chronic exposure reference values such as reference doses (RfDs), reference concentrations (RfCs), tolerable daily intakes (TDIs), cancer slope factors, etc. and key pharmacokinetic model parameters for 47 VOCs. Using steady-state solutions to a generic physiologically-based pharmacokinetic (PBPK) model structure, we estimated chemical-specific steady-state venous blood concentrations across chemicals associated with unit oral and inhalation exposure rates and with chronic exposure at the identified exposure reference values. The geometric means of the slopes relating modeled steady-state blood concentrations to steady-state exposure to a unit oral dose or unit inhalation concentration among 38 compounds with available pharmacokinetic parameters were 12.0 microg/L per mg/kg-d (geometric standard deviation [GSD] of 3.2) and 3.2 microg/L per mg/m(3) (GSD=1.7), respectively. Chemical-specific blood concentration screening values based on non-cancer reference values for both oral and inhalation exposure range from 0.0005 to 100 microg/L; blood concentrations associated with cancer risk-specific doses at the 1E-05 risk level ranged from 5E-06 to 6E-02 microg/L. The distribution of modeled steady-state blood concentrations associated with unit exposure levels across VOCs may provide a basis for estimating blood concentration screening values for VOCs that lack chemical-specific pharmacokinetic data. The screening blood concentrations presented here provide a tool for risk assessment-based evaluation of population biomonitoring data for VOCs and are most appropriately applied to central tendency estimates for such datasets. Copyright (c) 2010 Elsevier Inc. All rights reserved.

Lethal and sublethal endpoints observed for Artemia exposed to two reference toxicants and an ecotoxicological concern organic compound.

PubMed

Manfra, Loredana; Canepa, Sara; Piazza, Veronica; Faimali, Marco

2016-01-01

Swimming speed alteration and mortality assays with the marine crustacean Artemia franciscana were carried out. EC50 and LC50 values after 24-48h exposures were calculated for two reference toxicants, copper sulphate pentahydrate (CuSO4·5H2O) and Sodium Dodecyl Sulphate (SDS), and an ecotoxicological concern organic compound, Diethylene Glycol (DEG). Different end-points have been evaluated, in order to point out their sensitivity levels. The swimming speed alteration (SSA) was compared to mortality values and also to the hatching rate inhibition (literature data). SSA resulted to be more sensitive than the mortality and with a sensitivity comparable to (or even higher than) the hatching rate endpoint. Copyright © 2015 Elsevier Inc. All rights reserved.

Selectivity of similar compounds' identification using IR spectrometry: β-Lactam antibiotics

NASA Astrophysics Data System (ADS)

Sadlej-Sosnowska, Nina; Ocios, Agnieszka; Fuks, Leon

2006-07-01

The study aims to develop a reliable, quantitative method for positive identification or discrimination of a substance, when it is compared to a set of similar ones. In the course of the study a group of structurally related compounds, namely a set of β-lactam antimicrobial agents has been explored. Identification of a substance was based on the comparison of its spectrum with that of a reference material by using two functional algorithms. The algorithm based on the calculation of correlation coefficient between the first derivatives of the spectra has been proved more powerful than that using the original spectra. Then the results in a few spectral regions were likened. Limiting values were proposed for correlation coefficients that allow for qualification of a substance as identical to the reference one.

Spectroscopic characterization and quantitative determination of atorvastatin calcium impurities by novel HPLC method

NASA Astrophysics Data System (ADS)

Gupta, Lokesh Kumar

2012-11-01

Seven process related impurities were identified by LC-MS in the atorvastatin calcium drug substance. These impurities were identified by LC-MS. The structure of impurities was confirmed by modern spectroscopic techniques like 1H NMR and IR and physicochemical studies conducted by using synthesized authentic reference compounds. The synthesized reference samples of the impurity compounds were used for the quantitative HPLC determination. These impurities were detected by newly developed gradient, reverse phase high performance liquid chromatographic (HPLC) method. The system suitability of HPLC analysis established the validity of the separation. The analytical method was validated according to International Conference of Harmonization (ICH) with respect to specificity, precision, accuracy, linearity, robustness and stability of analytical solutions to demonstrate the power of newly developed HPLC method.

Novel pyrazole derivatives with oxa/thiadiazolyl, pyrazolyl moieties and pyrazolo[4,3-d]-pyrimidine derivatives as potential antimicrobial and anticancer agents.

PubMed

Hafez, Hend N; El-Gazzar, Abdel-Rhman B A; Al-Hussain, Sami A

2016-05-15

A series of [4-amino-3-(4-chlorophenyl)-1H-pyrazol-5-yl](3,5-dimethyl-1H-pyrazol-1-yl)-methanone and 6-amino-3-(4-chlorophenyl)-5-methyl-1,6-dihydro-7H-pyrazolo[4,3-d]-pyrimidin-7-one have been synthesized from ethyl 4-amino-3-(4-chlorophenyl)-pyrazol-5-carboxylate. The newly synthesized compounds were characterized by IR, (1)H NMR, (13)CNMR, Mass spectra and Elemental analysis. The compounds were evaluated for their in vitro antimicrobial and anticancer activity. Among the synthesized compounds, compounds 7a,b and 15 exhibited higher anticancer activity than the doxorubicin as reference drug. Most of the newly synthesized compounds have good to excellent antimicrobial activity. Copyright © 2016 Elsevier Ltd. All rights reserved.

Effects of twenty-five compounds on four species of aquatic fungi (Saprolegniales) pathogenic to fish

USGS Publications Warehouse

Bailey, T.A.

1984-01-01

Four species of aquatic fungi (Achlya flagellata, A. racemosa, Saprolegnia hypogyna, and S. megasperma) were exposed to 25 chemicals representing seven classes of compounds for 15 and 60 min, in an effort to identify potential fungicidal agents for use in fish culture. The antifungal activity of each chemical was compared with that of malachite green, a reference compound with known fungicidal properties but not registered for fishery use. Six compounds which inhibited fungal growth on artificial media at concentrations of < 100 mg/l (listed in order of decreasing antifungal activity) were the cationics Du-terA? and copper oxychloride sulfate, the amine LesanA?, the amide BAS-389-O1F and the cationics CuprimyxinA? and RoccalA? II. Certain chemicals from these classes of compounds may have promise as aquatic fungicides.

An approach to shortening the timeframe between the emergence of new compounds on the drugs market and the availability of reference standards: The microscale syntheses of nitrazolam and clonazolam for use as reference materials, utilizing polymer-supported reagents.

PubMed

Dowling, Geraldine; Kavanagh, Pierce V; Eckhardt, Hans-Georg; Twamley, Brendan; Hessman, Gary; McLaughlin, Gavin; O'Brien, John; Brandt, Simon D

2018-03-15

Nitrazolam and clonazolam are 2 designer benzodiazepines available from Internet retailers. There is growing evidence suggesting that such compounds have the potential to cause severe adverse events. Information about tolerability in humans is scarce but typically, low doses can be difficult to administer for users when handling bulk material. Variability of the active ingredient in tablet formulations can also be of a concern. Customs, toxicology and forensic laboratories are increasingly encountering designer benzodiazepines, both in tablet and powdered form. The unavailability of reference standards can impact on the ability to identify these compounds. Therefore, the need arises for exploring in-house approaches to the preparation of new psychoactive substances (NPS) that can be carried out in a timely manner. The present study was triggered when samples of clonazolam were received in powdered and tablet form at a time when reference material for this drug was commercially unavailable. Therefore, microscale syntheses of clonazolam and its deschloro analog nitrazolam were developed utilizing polymer-supported reagents starting from 2-amino-2'-chloro-5-nitrobenzophenone (clonazolam) and 2-amino-5-nitrobenzophenone (nitrazolam). The final reaction step forming the 1,2,4-triazole ring moiety was performed within a gas chromatography-mass spectrometry (GC-MS) injector. A comparison with a preparative scale synthesis of both benzodiazepine derivatives showed that microscale synthesis might be an attractive option for a forensic laboratory in terms of time and cost savings when compared with traditional methods of synthesis and when qualitative identifications are needed to direct forensic casework. The reaction by-product profiles for both the micro and the preparative scale syntheses are also presented. Copyright © 2018 John Wiley & Sons, Ltd.

Identification and quantification of volatile organic compounds using systematic single-ion chromatograms

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

Tsuchiya, Yoshio; Kanabus-Kaminska, J.M.

1996-12-31

In order to determine the background level of volatile organic compounds (VOCs) in Canadian indoor air, a method of identification and quantification at a level of 0.3 {micro}g/m{sup 3} using systematic single-ion chromatograms (SICs) has been developed. The compounds selected for measurement included several halogenated compounds, oxygen compounds, terpenes, and C8 to C16 n-alkanes. Air samples were taken in 3-layered sorbent tubes and trapped compounds were thermally desorbed into the helium stream of a gas chromatograph/mass spectrometer (GC/MS) analytical system. Total quantities of volatile organic compounds (TVOCs) were measured using a flame ionization detector (FID). Individual compounds were analyzed bymore » a GC/MS. For the identification of compounds in the main stream GC effluent, both the specific GC retention and mass spectra were used. About 50 selected SICs were routinely extracted from a total ion chromatogram (TIC) to detect and quantify compounds. For each compound, a single representative ion was selected. The specific retention was calculated from the elution time on the SIC. For quantification, ion counts under a peak in the SIC were measured. The single-ion MS response factor for some of the compounds was experimentally determined using a dynamic reference procedure.« less

A postmenopause-like model of ovariectomized Wistar rats to identify active principles of Erythrina lysistemon (Fabaceae).

PubMed

Mvondo, M A; Njamen, D; Fomum, S Tanee; Wandji, J; Vollmer, Günter

2011-10-01

To determine whether the two major compounds of Erythrina lysistemon are active principles accounting for Erythrina estrogenic effects, we used a postmenopause-like model of ovariectomized Wistar rats to evaluate their effects on some menopausal problems. Ovariectomized rats were orally treated either with compound 1 or compound 2 at 1 and 10 mg/kg BW for 28 days. Estradiol valerate served as the reference substance. As results, compounds 1 and 2 displayed estrogen-like effects on the uterus and the vagina, and reduced atherogenic risks by decreasing the two assessed atherogenic parameters, the total cholesterol/HDL-cholesterol ratio and the atherogenic index of plasma. Copyright © 2011 Elsevier B.V. All rights reserved.

3-methyl-1,2,3-butanetricarboxylic acid: An atmospheric tracer for terpene secondary organic aerosol

NASA Astrophysics Data System (ADS)

Szmigielski, Rafal; Surratt, Jason D.; Gómez-González, Yadian; Van der Veken, Pieter; Kourtchev, Ivan; Vermeylen, Reinhilde; Blockhuys, Frank; Jaoui, Mohammed; Kleindienst, Tadeusz E.; Lewandowski, Michael; Offenberg, John H.; Edney, Edward O.; Seinfeld, John H.; Maenhaut, Willy; Claeys, Magda

2007-12-01

Highly oxygenated compounds assigned to be oxidation products of α-pinene have recently been observed in substantial concentrations in ambient aerosols. Here, we confirm the unknown α-pinene tracer compound with molecular weight (MW) 204 as the C8-tricarboxylic acid 3-methyl-1,2,3-butanetricarboxylic acid. Its gas and liquid chromatographic behaviors and its mass spectral characteristics in electron ionization and negative ion electrospray ionization perfectly agree with those of a synthesized reference compound. The formation of this compound is explained by further reaction of cis-pinonic acid involving participation of the OH radical. This study illustrates that complex, multi-generation chemistry holds for the photooxidation of α-pinene in the presence of NOx.

Proton-transfer-reaction/ion-mobility-spectrometer and method of using the same

NASA Technical Reports Server (NTRS)

Kanik, Isik (Inventor); Beegle, Luther W. (Inventor)

2004-01-01

A high-pressure hollow cathode ionizer is combined with an ion-mobility-spectrometer (IMS) for the detection of trace amounts of organic compounds in gas. The ionizer uses H.sub.3 0.sup.+, ions which do not react with air to ionize the organic compounds and the organic compounds are soft ionized. The ionized organic compounds are detected in the IMS at levels of parts per billion and identified using calibrated reference tables. Applications include but are not limited to the fields of: (1) medicine as a breath analyzer for detection of lung cancer, diabetes, liver cirrhosis, (2) law enforcement in drug interdiction and explosives detection, (3) food monitoring and control, (4) environmental monitoring and (5) space applications.

Scavenger Activity Evaluation of the Clove Bud Essential Oil (Eugenia caryophyllus) and Eugenol Derivatives Employing ABTS+• Decolorization

PubMed Central

Merchán Arenas, Diego R.; Acevedo, Amner Muñoz; Vargas Méndez, Leonor Y.; Kouznetsov, Vladimir V.

2011-01-01

The essential oil (EO) of clove bud dried fruits from Eugenia caryophyllus was obtained by a conventional hydrodistillation process in an excellent yield (11.7 %). Its chemical composition was analyzed by GC-MS, identifying eugenol as a main constituent (60.5%). Four eugenol-like molecules, γ-diisoeugenol, hydroxymethyleugenol, dihydroeugenol and 1,3-dioxanylphenol, were synthesized using eugenol or isoeugenol as initial precursors under green chemistry protocols. To evaluate the possible antioxidant capacity of eugenol compounds including the clove bud EO, the Trolox® Equivalent Antioxidant Capacity value, obtained by the ABTS+• radical-cation discoloration method, was employed. The methodology was performed in a UV-Vis reader of 96-well microplates (dilution methodology), using well-known antioxidant agents (BHA, BHT and vitamin E) as reference compounds. It was found that the prepared eugenol derivatives had a more potent free radical scavenger activity than the reference compounds. In particular, the most active molecules, γ-diisoeugenol and 1,3-dioxanylphenol, were ca. 3-fold more potent than vitamin E. PMID:22145105

Scavenger Activity Evaluation of the Clove Bud Essential Oil (Eugenia caryophyllus) and Eugenol Derivatives Employing ABTS Decolorization.

PubMed

Merchán Arenas, Diego R; Acevedo, Amner Muñoz; Vargas Méndez, Leonor Y; Kouznetsov, Vladimir V

2011-01-01

The essential oil (EO) of clove bud dried fruits from Eugenia caryophyllus was obtained by a conventional hydrodistillation process in an excellent yield (11.7 %). Its chemical composition was analyzed by GC-MS, identifying eugenol as a main constituent (60.5%). Four eugenol-like molecules, γ-diisoeugenol, hydroxymethyleugenol, dihydroeugenol and 1,3-dioxanylphenol, were synthesized using eugenol or isoeugenol as initial precursors under green chemistry protocols. To evaluate the possible antioxidant capacity of eugenol compounds including the clove bud EO, the Trolox® Equivalent Antioxidant Capacity value, obtained by the ABTS(+•) radical-cation discoloration method, was employed. The methodology was performed in a UV-Vis reader of 96-well microplates (dilution methodology), using well-known antioxidant agents (BHA, BHT and vitamin E) as reference compounds. It was found that the prepared eugenol derivatives had a more potent free radical scavenger activity than the reference compounds. In particular, the most active molecules, γ-diisoeugenol and 1,3-dioxanylphenol, were ca. 3-fold more potent than vitamin E.

Arsenic in Food

MedlinePlus

... It is found in water, air, food, and soil in organic and inorganic forms. The FDA has ... of arsenic compounds in water, food, air, and soil: organic and inorganic (these together are referred to ...

The Involvement of Morphological Information in the Memorization of Chinese Compound Words: Evidence from Memory Errors.

PubMed

Liu, Duo

2016-02-01

The processing of morphological information during Chinese word memorization was investigated in the present study. Participants were asked to study words presented to them on a computer screen in the studying phase and then judge whether presented words were old or new in the test phase. In addition to parent words (i.e. the words studied in the study phase), the test phase also included conjunction lures (constructed out of morphemes in the parent words) and new words (constructed out of entirely new morphemes). Three kinds of words (i.e. subordinate compounds, coordinative compounds, and single-morpheme words) were involved. In both two experiments, performance on lures worsened when both parent words and lures were coordinative compounds, compared to the condition when both were subordinate compounds. The different performance between compounds with different compounding structures in the test phase suggests the involvement of morphological information in the memorization of Chinese compound words. The spreading activation theory for memory and the interactive activation model for the processing of morphologically complex words were referred to for interpreting the results.

Paleogene stratigraphy of the Solomons Island, Maryland corehole

USGS Publications Warehouse

Gibson, Thomas G.; Bybell, Laurel M.

1994-01-01

Purge and trap capillary gas chromatography/mass spectrometry is a rapid, precise, accurate method for determining volatile organic compounds in samples of surface water and ground water. The method can be used to determine 59 selected compounds, including chlorofluorohydrocarbons, aromatic hydrocarbons, and halogenated hydrocarbons. The volatile organic compounds are removed from the sample matrix by actively purging the sample with helium. The volatile organic compounds are collected onto a sorbant trap, thermally desorbed, separated by a Megabore gas chromatographic capillary column, ionized by electron impact, and determined by a full-scan quadrupole mass spectrometer. Compound identification is confirmed by the gas chromatographic retention time and by the resultant mass spectrum. Unknown compounds detected in a sample can be tentatively identified by comparing the unknown mass spectrum to reference spectra in the mass-spectra computer-data system library compiled by the National Institute of Standards and Technology. Method detection limits for the selected compounds range from 0.05 to 0.2 microgram per liter. Recoveries for the majority of the selected compounds ranged from 80 to 120 percent, with relative standard deviations of less than 10 percent.

Design, synthesis, evaluation, and molecular docking of ursolic acid derivatives containing a nitrogen heterocycle as anti-inflammatory agents.

PubMed

Wei, Zhi-Yu; Chi, Ke-Qiang; Wang, Ke-Si; Wu, Jie; Liu, Li-Ping; Piao, Hu-Ri

2018-06-01

Ursolic acid derivatives containing oxadiazole, triazolone, and piperazine moieties were synthesized in an attempt to develop potent anti-inflammatory agents. Structures of the synthesized compounds were elucidated by 1 H NMR, 13 C NMR, and HRMS. Most of the synthesized compounds showed pronounced anti-inflammatory effects at 100 mg/kg. In particular, compound 11b, which displayed the most potent anti-inflammatory activity of all of the compounds prepared, with 69.76% inhibition after intraperitoneal administration, was more potent than the reference drugs indomethacin and ibuprofen. The cytotoxicity of the compounds was also assessed by the 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) assay, and no compounds showed any appreciable cytotoxic activity (IC 50 >100 μmol/L). Furthermore, molecular docking studies of the synthesized compounds were performed to rationalize the obtained biological results. Overall, the results indicate that compound 11b could be a therapeutic candidate for the treatment of inflammation. Copyright © 2018 Elsevier Ltd. All rights reserved.

Characterization of Fumonisin A-Series by High-Resolution Liquid Chromatography-Orbitrap Mass Spectrometry

PubMed Central

Tamura, Masayoshi; Mochizuki, Naoki; Nagatomi, Yasushi; Toriba, Akira; Hayakawa, Kazuichi

2014-01-01

Fumonisin A-series (FAs) in a reference material of corn sample that was naturally contaminated with fumonisins was characterized using high-resolution liquid chromatography-Orbitrap mass spectrometry (LC-Orbitap MS). Peaks for fumonisin B1 (FB1), fumonisin B2 (FB2), and fumonisin B3 (FB3), in addition to three peaks corresponding to unknown compounds I, II, and III, were detected in the chromatogram for the corn sample. Fragment ion analysis for FB1, FB2, and FB3 showed that while the ions formed at m/z values of 200–800 were similar to those formed by the cleavage of the tricarballylic acids and the hydroxyl groups, the fragmentation patterns at m/z values of 50–200 varied depending on the hydroxyl group locations in the compounds. Fragment ion analysis of compounds I–III revealed structural similarities to FBs, only differing by an additional C2H2O in the unknown compounds. Using these results and by comparing the product ion mass spectra of compound I with fumonisin A1 (FA1) synthesized from FB1 standards, compounds I–III were hypothesized to be N-acetyl analogs of FBs: fumonisins A1 (FA1), A2 (FA2), and A3 (FA3). The method for determining concentrations was validated with FA1, FB1, FB2, and FB3 standards and applied to analyze the reference material. The FB1, FB2, and FB3 analytical levels were within acceptance limits and the amount of FA1 in the material was ~15% of FB1 amount at 4.2 mg/kg. PMID:25153258

Exploration of the anti-enterovirus activity of a series of pleconaril/pirodavir-like compounds.

PubMed

Bernard, Angela; Lacroix, Céline; Cabiddu, Maria G; Neyts, Johan; Leyssen, Pieter; Pompei, Raffaello

2015-04-01

The Enterovirus genus of the Picornaviridae is represented by several viral pathogens that are associated with human disease, namely Poliovirus 1, Enterovirus 71 and Rhinoviruses. Enterovirus 71 has been associated with encephalitis, while Rhinoviruses are a major cause of asthma exacerbations and chronic obstructive pulmonary disease. Based on the structure of both pleconaril and pirodavir, we previously synthesized some original compounds as potential inhibitors of Rhinovirus replication. These compounds were explored for in vitro antiviral potential on other human pathogenic Enteroviruses, namely Enterovirus 71 on rhabdo-myosarcoma cells, Coxsackievirus B3 on Vero cells, Poliovirus 1 and Echovirus 11 on BGM cells. Activity was confirmed for compound against Rhinovirus 14. Furthermore, few compounds showed a cell-protective effect on Enterovirus 71, presented a marked improvement as compared to the reference drug pleconaril for inhibitory activity on both Enterovirus 71 and Poliovirus 1. The most striking observation was the clear cell protective effect for the set of analogues in a virus-cell-based assay for Echovirus 11 with an effective concentration (EC50) as low as 0.3 µM (Selectivity index or SI = 483), and selectivity indexes greater than 857 (EC50 = 0.6 µM) and 1524 (EC50 = 0.33 µM). Some of the evaluated compounds showed potent and selective antiviral activity against several enterovirus species, such as Enterovirus 71 (EV-A), Echovirus 11 (EV-B), and Poliovirus 1 (EV-C). This could be used as a starting point for the development of other pleconaril/pirodavir-like enterovirus inhibitors with broad-spectrum activity and improved effects as compared to the reference drugs. © The Author(s) 2015.

A novel strategy with standardized reference extract qualification and single compound quantitative evaluation for quality control of Panax notoginseng used as a functional food.

PubMed

Li, S P; Qiao, C F; Chen, Y W; Zhao, J; Cui, X M; Zhang, Q W; Liu, X M; Hu, D J

2013-10-25

Root of Panax notoginseng (Burk.) F.H. Chen (Sanqi in Chinese) is one of traditional Chinese medicines (TCMs) based functional food. Saponins are the major bioactive components. The shortage of reference compounds or chemical standards is one of the main bottlenecks for quality control of TCMs. A novel strategy, i.e. standardized reference extract based qualification and single calibrated components directly quantitative estimation of multiple analytes, was proposed to easily and effectively control the quality of natural functional foods such as Sanqi. The feasibility and credibility of this methodology were also assessed with a developed fast HPLC method. Five saponins, including ginsenoside Rg1, Re, Rb1, Rd and notoginsenoside R1 were rapidly separated using a conventional HPLC in 20 min. The quantification method was also compared with individual calibration curve method. The strategy is feasible and credible, which is easily and effectively adapted for improving the quality control of natural functional foods such as Sanqi. Copyright © 2013 Elsevier B.V. All rights reserved.

Rapid characterisation and identification of compounds in Saposhnikoviae Radix by high-performance liquid chromatography coupled with electrospray ionisation quadrupole time-of-flight mass spectrometry.

PubMed

Chen, Luxiao; Chen, Xiangyang; Su, Lei; Jiang, Yanyan; Liu, Bin

2018-04-01

Saposhnikoviae Radix (SR), the dried root of Saposhnikovia divaricata (Turcz.) Schischk. (Umbelliferae), is commonly used as a traditional Chinese medicine. In this study, a rapid and accurate method was firstly, developed for the qualitative analysis of SR by high-performance liquid chromatography coupled with electrospray ionisation quadrupole time-of-flight mass spectrometry (HPLC-ESI-Q-TOF-MS/MS). A total of 45 compounds were identified or tentatively characterised, including 13 chromones, 28 coumarins and four others. Among them, 16 compounds were identified from SR for the first time. In addition, six chromones reference standards, including two isolated compounds of 3'-O-angeloylhamaudol and norcimifugin from the extraction of SR, were used to study the fragmentation pathways of chromones. The developed method was effective for characterising the compounds of SR, and the results of the study enriched the understanding of the chemical connotation.

Antioxidant activity from encapsulated Cinnamaldehyde-Chitosan

NASA Astrophysics Data System (ADS)

Ariestiani, Bonita; Purbowatingrum; Ngadiwiyana; Ismiyarto; Fachriyah, Enny; Nurani, Khikmah

2018-05-01

Cinnamaldehyde compound is a powerful antioxidant agent that can effectively combat the free radicals referred to superoxide anions and hydroxy radicals, as well as other free radicals in in vitro testing. An antioxidant is an electron donor or reductant. antioxidants are also compounds that can inhibit oxidation reactions by binding to free radicals and highly reactive molecules. As a result, cell damage will be inhibited. However, the use of this compound still provides unsatisfactory results due to its degradation during the absorption process. The solution offered to solve the problem is by encapsulated it within chitosan nanoparticles that serve to protect the bioactive compound from degradation, increases of solubility and delivery of a bioactive compound to the target site by using freeze-drying technique. The value of encapsulation efficiency (EE) of cinnamaldyhde which encapsulated within chitosan nanoparticles is about 74,389% also antioxidant activity test showed that cinnamaldehyde encapsulated by nanochitosan could inhibit free radicals of 223.44 in IC50.

Design, synthesis, molecular modeling and biological evaluation of novel 2,3-dihydrophthalazine-1,4-dione derivatives as potential anticonvulsant agents

NASA Astrophysics Data System (ADS)

El-Helby, Abdel Ghany A.; Ayyad, Rezk R.; Sakr, Helmy M.; Abdelrahim, Adel S.; El-Adl, K.; Sherbiny, Farag S.; Eissa, Ibrahim H.; Khalifa, Mohamed M.

2017-02-01

In view of their expected anticonvulsant activity, some novel derivatives of 2,3-dihydrophthalazine-1,4-dione 4-22 were designed, synthesized and evaluated using pentylenetetrazole (PTZ) and picrotoxin as convulsion-inducing models. Moreover, the most active compounds were tested against electrical induced convulsion using maximal electroshock (MES) models of seizures. Most of the tested compounds showed considerable anticonvulsant activity in at least one of the anticonvulsant tests. Compounds 13 and 14g were proved to be the most potent compounds of this series with relatively low toxicity in the median lethal dose test when compared with the reference drug. Molecular modeling studies were done to verify the biological activity. The obtained results showed that the most potent compounds could be useful as a template for future design, optimization, and investigation to produce more active analogues.

Description, Properties, and Degradation of Selected Volatile Organic Compounds Detected in Ground Water--A Review of Selected Literature

USGS Publications Warehouse

Lawrence, Stephen J.

2006-01-01

This report provides abridged information describing the most salient properties and biodegradation of 27 chlorinated volatile organic compounds detected during ground-water studies in the United States. This information is condensed from an extensive list of reports, papers, and literature published by the U.S. Government, various State governments, and peer-reviewed journals. The list includes literature reviews, compilations, and summaries describing volatile organic compounds in ground water. This report cross-references common names and synonyms associated with volatile organic compounds with the naming conventions supported by the International Union of Pure and Applied Chemistry. In addition, the report describes basic physical characteristics of those compounds such as Henry's Law constant, water solubility, density, octanol-water partition (log Kow), and organic carbon partition (log Koc) coefficients. Descriptions and illustrations are provided for natural and laboratory biodegradation rates, chemical by-products, and degradation pathways.

Discovering some novel 7-chloroquinolines carrying a biologically active benzenesulfonamide moiety as a new class of anticancer agents.

PubMed

Al-Dosari, Mohammed Salem; Ghorab, Mostafa Mohamed; Al-Said, Mansour Sulaiman; Nissan, Yassin Mohammed

2013-01-01

Based on the reported anticancer activity of quinolines, a new series of 7-chloroquinoline derivatives bearing the biologically active benzenesulfonamide moiety 2-17 and 19-25 were synthesized starting with 4,7-dichloroquinolne 1. Compound 17 was the most active compound with IC(50) value 64.41, 75.05 and 30.71 µM compared with Doxorubicin as reference drug with IC(50) values 82.53, 88.32 and 73.72 µM on breast cancer cells, skin cancer cells and neuroblastoma, respectively. All the synthesized compounds were evaluated for their in vitro anticancer activity on breast cancer cells, skin cancer cells and neuroblastoma cells. Most of the synthesized compounds showed moderate activity. In order to suggest the mechanism of action for their cytotoxic activity, molecular docking for all synthesized compounds was done on the active site of phosphoinositide kinase (PI3K) and good results were obtained.

Synthesis and in vitro antiproliferative and antibacterial activity of new thiazolidine-2,4-dione derivatives.

PubMed

Trotsko, Nazar; Przekora, Agata; Zalewska, Justyna; Ginalska, Grażyna; Paneth, Agata; Wujec, Monika

2018-12-01

In our present research, we synthesised new thiazolidine-2,4-diones (12-28). All the newly synthesised compounds were evaluated for antiproliferative and antibacterial activity. Antiproliferative evaluation was carried out using normal human skin fibroblasts and tumour cell lines: A549, HepG2, and MCF-7. The IC 50 values were determined for tested compounds revealing antiproliferative activity. Moreover, safety index (SI) was calculated. Among all tested derivatives, the compound 18 revealed the highest antiproliferative activity against human lung, breast, and liver cancer cells. More importantly, the derivative 18 showed meaningfully lower IC 50 values when compared to the reference substance, irinotecan, and relatively high SI values. Moreover, newly synthesised compounds were screened for the bacteria growth inhibition in vitro. According to our screening results, most active compound was the derivative 18 against Gram-positive bacteria. Therefore, it may be implied that the novel compound 18 appears to be a very promising agent for anticancer treatment.

Compounds from African Medicinal Plants with Activities Against Selected Parasitic Diseases: Schistosomiasis, Trypanosomiasis and Leishmaniasis.

PubMed

Simoben, Conrad V; Ntie-Kang, Fidele; Akone, Sergi H; Sippl, Wolfgang

2018-05-09

Parasitic diseases continue to represent a threat on a global scale, particularly among the poorest countries in the world. This is particularly because of the absence of vaccines, and in some cases, resistance against available drugs, currently being used for their treatment. In this review emphasis is laid on natural products and scaffolds from African medicinal plants (AMPs) for lead drug discovery and possible further development of drugs for the treatment of parasitic diseases. In the discussion, emphasis has been laid on alkaloids, terpenoids, quinones, flavonoids and narrower compound classes of compounds with micromolar range activities against Schistosoma, Trypanosoma and Leishmania species. In each subparagraph, emphasis is laid on the compound subclasses with most promising in vitro and/or in vivo activities of plant extracts and isolated compounds. Suggestions for future drug development from African medicinal plants have also been provided. This review covering 167 references, including 82 compounds, provides information published within two decades (1997-2017).

Genetics Home Reference: pyruvate carboxylase deficiency

MedlinePlus

... infants have severe lactic acidosis, a buildup of ammonia in the blood (hyperammonemia), and liver failure. They ... carboxylase allows compounds such as lactic acid and ammonia to build up and damage organs and tissues. ...

[Study on chemical constituents from leaves of Tripterygium wilfordii].

PubMed

Cao, Xu; Li, Chuangjun; Yang, Jingzhi; Wei, Baixing; Luo, Yongming; Zhang, Dongming

2011-04-01

In order to study the chemical constituents of the leaves of Tripterygium wilfordii and provide references for the bio-active study, we isolated nine compounds from the dried leaves of Tripterygium wilfordii. Their structures were determined by application of spectroscopic (NMR, MS) and chemical methods. These compounds were isolated and identified as (+)-lyoniresinol (1), (+)-isolariciresinol (2), burselignan (3), dibutyl phthalate (4), cyclo-(S-Pro-R-Phe) (5), cyclo-(S-Pro-R-Leu) (6), cyclo-(S-Pro-S-Ile) (7), 3-hydroxy-1-(4-hydroxy-3,5-dimethoxyphenyl)-1-propanone (8) and daucosterol (9). Compounds 1-3, 5-8 were isolated from this plant for the first time.

Properties of colour reference solutions of the European Pharmacopoea in CIE L*a*b* colour space.

PubMed

Subert, J; Farsa, O; Gajdosová, Z

2006-12-01

The coordinates of CIE L*a*b* uniform colour space have been acquired from the transmitance spectra of colour reference solutions of European Pharmacopoeia (Ph.Eur.). Calculation of colour differences of these solutions from purified water deltaE* gave their values in the range between 0.7 (B9 solution) to 36 (Y1 solution) CIE units. Excluding red colour reference soulutions, deltaE* values did not depend on concentrations of colour compounds linearly. Small deltaE* values founded by the brown and brownish-yellow colour reference solutions of the lowest concentrations can possibly cause some problems of visual examination of the degree of coloration of liquids according to Ph.Eur.

A reference data set for validating vapor pressure measurement techniques: homologous series of polyethylene glycols

NASA Astrophysics Data System (ADS)

Krieger, Ulrich K.; Siegrist, Franziska; Marcolli, Claudia; Emanuelsson, Eva U.; Gøbel, Freya M.; Bilde, Merete; Marsh, Aleksandra; Reid, Jonathan P.; Huisman, Andrew J.; Riipinen, Ilona; Hyttinen, Noora; Myllys, Nanna; Kurtén, Theo; Bannan, Thomas; Percival, Carl J.; Topping, David

2018-01-01

To predict atmospheric partitioning of organic compounds between gas and aerosol particle phase based on explicit models for gas phase chemistry, saturation vapor pressures of the compounds need to be estimated. Estimation methods based on functional group contributions require training sets of compounds with well-established saturation vapor pressures. However, vapor pressures of semivolatile and low-volatility organic molecules at atmospheric temperatures reported in the literature often differ by several orders of magnitude between measurement techniques. These discrepancies exceed the stated uncertainty of each technique which is generally reported to be smaller than a factor of 2. At present, there is no general reference technique for measuring saturation vapor pressures of atmospherically relevant compounds with low vapor pressures at atmospheric temperatures. To address this problem, we measured vapor pressures with different techniques over a wide temperature range for intercomparison and to establish a reliable training set. We determined saturation vapor pressures for the homologous series of polyethylene glycols (H - (O - CH2 - CH2)n - OH) for n = 3 to n = 8 ranging in vapor pressure at 298 K from 10-7 to 5×10-2 Pa and compare them with quantum chemistry calculations. Such a homologous series provides a reference set that covers several orders of magnitude in saturation vapor pressure, allowing a critical assessment of the lower limits of detection of vapor pressures for the different techniques as well as permitting the identification of potential sources of systematic error. Also, internal consistency within the series allows outlying data to be rejected more easily. Most of the measured vapor pressures agreed within the stated uncertainty range. Deviations mostly occurred for vapor pressure values approaching the lower detection limit of a technique. The good agreement between the measurement techniques (some of which are sensitive to the mass accommodation coefficient and some not) suggests that the mass accommodation coefficients of the studied compounds are close to unity. The quantum chemistry calculations were about 1 order of magnitude higher than the measurements. We find that extrapolation of vapor pressures from elevated to atmospheric temperatures is permissible over a range of about 100 K for these compounds, suggesting that measurements should be performed best at temperatures yielding the highest-accuracy data, allowing subsequent extrapolation to atmospheric temperatures.

Advanced strategies for quality control of Chinese medicines.

PubMed

Zhao, Jing; Ma, Shuang-Cheng; Li, Shao-Ping

2018-01-05

Quality control is always the critical issue for Chinese medicines (CMs) with their worldwide increasing use. Different from western medicine, CMs are usually considered that multiple constituents are responsible for the therapeutic effects. Therefore, quality control of CMs is a challenge. In 2011, the strategies for quantification, related to the markers, reference compounds and approaches, in quality control of CMs were reviewed (Li, et al., J. Pharm. Biomed. Anal., 2011, 55, 802-809). Since then, some new strategies have been proposed in these fields. Therefore, the review on the strategies for quality control of CMs should be updated to improve the safety and efficacy of CMs. Herein, novel strategies related to quality marker discovery, reference compound development and advanced approaches (focused on glyco-analysis) for quality control, during 2011-2016, were summarized and discussed. Copyright © 2017 Elsevier B.V. All rights reserved.

An evaluation of electronic cigarette formulations and aerosols for harmful and potentially harmful constituents (HPHCs) typically derived from combustion.

PubMed

Wagner, Karl A; Flora, Jason W; Melvin, Matt S; Avery, Karen C; Ballentine, Regina M; Brown, Anthony P; McKinney, Willie J

2018-06-01

U.S. FDA draft guidance recommends reporting quantities of designated harmful and potentially harmful constituents (HPHCs) in e-cigarette e-liquids and aerosols. The HPHC list comprises potential matrix-related compounds, flavors, nicotine, tobacco-related impurities, leachables, thermal degradation products, and combustion-related compounds. E-cigarettes contain trace levels of many of these constituents due to tobacco-derived nicotine and thermal degradation. However, combustion-related HPHCs are not likely to be found due to the relatively low operating temperatures of most e-cigarettes. The purpose of this work was to use highly sensitive, selective, and validated analytical methods to determine if these combustion-related HPHCs (three aromatic amines, five volatile organic compounds, and the polycyclic aromatic hydrocarbon benzo[a]pyrene) are detectable in commercial refill e-liquids, reference e-cigarette e-liquids, and aerosols generated from rechargeable e-cigarettes with disposable cartridges (often referred to as "cig-a-likes"). In addition, the transfer efficiency of these constituents from e-liquid to aerosol was evaluated when these HPHCs were added to the e-liquids prior to aerosol formation. This work demonstrates that combustion-related HPHCs are not present at measurable levels in the commercial and reference e-liquids or e-cigarette aerosols tested. Additionally, when combustion-related HPHCs are added to the e-liquids, they transfer to the aerosol with transfer efficiencies ranging from 49% to 99%. Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.

Discovery of Tyk2 inhibitors via the virtual site-directed fragment-based drug design.

PubMed

Jang, Woo Dae; Kim, Jun-Tae; Son, Hoon Young; Park, Seung Yeon; Cho, Young Sik; Koo, Tae-sung; Lee, Hyuk; Kang, Nam Sook

2015-09-15

In this study, we synthesized compound 12 with potent Tyk2 inhibitory activity from FBDD study and carried out a cell-based assay for Tyk2/STAT3 signaling activation upon IFNα5 stimulation. Compound 12 completely suppressed the IFNα5-mediated Tyk2/STAT3 signaling pathway as well as the basal levels of pSTAT3. Stimulation with IFNα/β leads to the tyrosine phosphorylation of the JAK1 and Tyk2 receptor-associated kinases with subsequent STATs activation, transmitting signals from the cell surface receptor to the nucleus. In conclusion, the potency of compound 12 to interrupt the signal transmission of Tyk2/STAT3 appeared to be equivalent or superior to that of the reference compound. Copyright © 2015 Elsevier Ltd. All rights reserved.

Extraction of phenolic compounds from extra virgin olive oil by a natural deep eutectic solvent: Data on UV absorption of the extracts.

PubMed

Paradiso, Vito Michele; Clemente, Antonia; Summo, Carmine; Pasqualone, Antonella; Caponio, Francesco

2016-09-01

This data article refers to the paper "Towards green analysis of virgin olive oil phenolic compounds: extraction by a natural deep eutectic solvent and direct spectrophotometric detection" [1]. A deep eutectic solvent (DES) based on lactic acid and glucose was used as green solvent for phenolic compounds. Eight standard phenolic compounds were solubilized in the DES. Then, a set of extra virgin olive oil (EVOO) samples (n=65) were submitted to liquid-liquid extraction by the DES. The standard solutions and the extracts were analyzed by UV spectrophotometry. This article reports the spectral data of both the standard solutions and the 65 extracts, as well as the total phenolic content of the corresponding oils, assessed by the Folin-Ciocalteu assay.

Novel Penicillin-Type Analogues Bearing a Variable Substituted 2-Azetidinone Ring at Position 6: Synthesis and Biological Evaluation.

PubMed

De Rosa, Margherita; Vigliotta, Giovanni; Palma, Giuseppe; Saturnino, Carmela; Soriente, Annunziata

2015-12-10

The synthesis and the biological activity of novel semi-synthetic β-lactam compounds containing an azetidinone moiety joined to the amino-nitrogen of the (+)-6-aminopenicillanic acid (6-APA) as new antibacterial agents is reported. The synthesized compounds were screened for their in vitro antimicrobial activity against a panel of Gram positive and Gram negative pathogens and environmental bacteria. Tested compounds displayed good antimicrobial activity against all tested Gram positive bacteria and for Staphylococcus aureus and Staphylococcus epidermidis antimicrobial activity resulted higher than that of the reference antibiotic. Additionally, in vitro cytotoxic screening was also carried out indicating that the compounds do not cause a cell vitality reduction effective at concentration next to and above those shown to be antimicrobial.

Chemical compounds from Chenopodium album Linn.

NASA Astrophysics Data System (ADS)

Zheng, Wei

2017-06-01

Bioactive components from Chenopodium album Linn. were isolated and identified in this research. Light petroleum, dichloromethane and n-BuOH were firstly applied to partition the 75% EtOH extract of Chenopodium album Linn. which were then subjected to normal-phase silica, ODS silica gel column chromatography and semi-preparative HPLC chromatography. By the employment of NMR method in this study, chemical structures of the compounds were elucidated. Three known compounds were isolated from Chenopodium album Linn., and identified as Isolariciresinol 4-O-β-D-glucopyranoside (1), (7’S, 8R, 8’R)-Isolariciresinol (2) and (7’S, 8R, 8’S)-Isolariciresinol (3) by comparison of their spectral data with references. This is the first time that isolation of the compounds mentioned above from Chenopodium album Linn. was achieved.

Synthesis and structure-activity relationship studies in a series of 2-substituted 1,3-dioxolanes modified at the cationic head.

PubMed

Angeli, P; Brasili, L; Cingolani, M L; Marucci, G; Piergentili, A; Pigini, M; Quaglia, W

1997-04-01

To develop ligands that may be useful in exploring muscarinic receptor heterogeneity, we synthesized a series of analogues of 2,2-diphenyl-[1,3]-dioxolan-4-ylmethyl-dimethylamine oxalate and methiodide bearing a modified cationic head. These compounds, when tested on tissues containing the three subtypes M1, M2, and M3, behaved as muscarinic antagonists whose results showed that different substituents on the quaternary and tertiary nitrogen affect affinity and selectivity in different ways. In particular comparison of the affinities of these ligands with those of the reference compounds points out that compounds bearing an ethyl substituent improve the affinity of the molecule at the three subtypes while compounds bearing a phenethyl substituent are more selective for the M3 sites.

Criminal Law Study Guide.

DTIC Science & Technology

1988-03-01

by the evidence and properly instructed upon, the court can convict the accused of more than one LIO, instead of thE greater compound offense charged...known charges should be referred to a single court- martial." R.C.M. 601(e)(2) (Discussion), MCM, 1984. Compounding the joinder problem was the...1976). 6. Truth is no defense. For example: Accused tells his superior officer, "You are a dirty , fat bastard." At his trial, the accused proves that

Methods for the synthesis of aza(deaza)xanthines as a basis of biologically active compounds

NASA Astrophysics Data System (ADS)

Babkov, D. A.; Geisman, A. N.; Khandazhinskaya, A. L.; Novikov, M. S.

2016-03-01

The review covers methods for the synthesis of aza(deaza)xanthines, i.e., fused pyrrolo-, pyrazolo- and triazolopyrimidine heterocyclic systems, which are common core structures of various biologically active compounds. The extensive range of modern synthetic approaches is organized according to target structures and starting building blocks. The presented material is intended to benefit broad audience of specialists in the fields of organic, medicinal and pharmaceutical chemistry. The bibliography includes 195 references.

Application of Copper Indium Gallium Diselenide Photovoltaic Cells to Extend the Endurance and Capabilities of Unmanned Aerial Vehicles

DTIC Science & Technology

2009-09-01

Group V element to make them n or p material. Another common group of semiconductors are called III–V compounds , such as gallium arsenide (GaAs), or...these compounds used for photovoltaics are Cadmium Telluride (CdTe), and Copper Indium Gallium DiSelenide, commonly referred to as CIGS [49]. Figure...INDIUM GALLIUM DISELENIDE PHOTOVOLTAIC CELLS TO EXTEND THE ENDURANCE AND CAPABILITIES OF UNMANNED AERIAL VEHICLES by William R. Hurd

Bioassay-guided investigation of two Monarda essential oils as repellents of yellow fever mosquito Aedes aegypti.

PubMed

Tabanca, Nurhayat; Bernier, Ulrich R; Ali, Abbas; Wang, Mei; Demirci, Betul; Blythe, Eugene K; Khan, Shabana I; Baser, K Husnu Can; Khan, Ikhlas A

2013-09-11

As part of an ongoing research program to identify active mosquito repellents, Monarda bradburiana Beck and Monarda fistulosa L. essential oils showed good repellent activity with minimum effective dosages (MED) of 0.055 ± 0.036 and 0.078 ± 0.027 mg/cm(2), respectively, compared to reference standard N,N-diethyl-3-methylbenzamide (DEET) (0.039 ± 0.014 mg/cm(2)). Systematic bioassay-guided fractionation of essential oils of both Monarda species was performed to identify the active repellent compounds, and isolated pure compounds were individually tested for repellency. Of the isolated compounds, carvacrol, thymol, eugenol, and carvacrol methyl ether were found to be the repellent compounds with MEDs in the range of 0.013-0.063 mg/cm(2). Active repellent compounds were also tested for larvicidal activity against 1-day-old Aedes aegypti larvae. Thymol was the best larvicide among the tested individual compounds (LD50 of 13.9 ppm). None of the individual compounds showed cytotoxicity against mammalian cells; however, the essential oils were toxic to all cell lines.

Determination of vapor pressures for nonpolar and semipolar organic compounds from gas chromatographic retention data

USGS Publications Warehouse

Hinckley, D.A.; Bidleman, T.F.; Foreman, W.T.; Tuschall, J.R.

1990-01-01

Vapor pressures for nonpolar and moderately polar organochlorine, pyrethroid, and organophosphate insecticides, phthalate esters, and organophosphate flame retardants were determined by capillary gas chromatography (GC). Organochlorines and polycyclic aromatic hydrocarbons with known liquid-phase vapor pressures (P??L) (standard compounds) were chromatographed along with two reference compounds n-C20 (elcosane) and p,p???-DDT on a 1.0-m-long poly(dimethylsiloxane) bonded-phase (BP-1) column to determine their vapor pressures by GC (P??GC). A plot of log P??L vs log P??GC for standard compounds was made to establish a correlation between measured and literature values, and this correlation was then used to compute P??L of test compounds from their measured P??GC. P??L of seven major components of technical chlordane, endosulfan and its metabolites, ??-hexachlorocyclohexane, mirex, and two components of technical toxaphene were determined by GC. This method provides vapor pressures within a factor of 2 of average literature values for nonpolar compounds, similar to reported interlaboratory precisions of vapor pressure determinations. GC tends to overestimate vapor pressures of moderately polar compounds. ?? 1990 American Chemical Society.

The inhibitory effects of phenolic Mannich bases on carbonic anhydrase I and II isoenzymes.

PubMed

Yamali, Cem; Tugrak, Mehtap; Gul, Halise Inci; Tanc, Muhammet; Supuran, Claudiu T

2016-12-01

Phenolic mono Mannich bases [2-[4-hydroxy-3-(aminomethyl)benzylidene]-2,3-dihydro-1H-inden-1-one (8-15)] and bis Mannich bases [2-[4-hydroxy-3,5-bis(aminomethyl)benzylidene]-2, 3-dihydro-1H-inden-1-one (2-7)] were synthesized starting from 2-(4-hydroxybenzylidene)-2, 3-dihydro-inden-1-one (1). This study was designed in order to investigate the carbonic anhydrase (CA, EC 4.2.1.1) inhibitory properties of a library of compounds incorporating the phenol functional group. All prepared compounds showed a low inhibition percentages on both human (h) isoforms hCA I and hCA II compared to the reference sulfonamide acetazolamide. Mannich bases 2-15 had lower inhibition percentages than the compound 1 on hCA I and hCA II, except compound 14, which is a Mannich base derivative of dipropylamine, which had a similar inhibitory power as compound 1 on hCA II. All compounds synthesized 1-15 were 1.3-1.9 times more effective on hCA II comparing with the effectivenes of the compounds on hCA I.

Chromatogram-Bioactivity Correlation-Based Discovery and Identification of Three Bioactive Compounds Affecting Endothelial Function in Ginkgo Biloba Extract.

PubMed

Liu, Hong; Tan, Li-Ping; Huang, Xin; Liao, Yi-Qiu; Zhang, Wei-Jian; Li, Pei-Bo; Wang, Yong-Gang; Peng, Wei; Wu, Zhong; Su, Wei-Wei; Yao, Hong-Liang

2018-05-03

Discovery and identification of three bioactive compounds affecting endothelial function in Ginkgo biloba Extract (GBE) based on chromatogram-bioactivity correlation analysis. Three portions were separated from GBE via D101 macroporous resin and then re-combined to prepare nine GBE samples. 21 compounds in GBE samples were identified through UFLC-DAD-Q-TOF-MS/MS. Correlation analysis between compounds differences and endothelin-1 (ET-1) in vivo in nine GBE samples was conducted. The analysis results indicated that three bioactive compounds had close relevance to ET-1: Kaempferol-3- O -α-l-glucoside, 3- O -{2- O -{6- O -[P-OH-trans-cinnamoyl]-β-d-glucosyl}-α-rhamnosyl} Quercetin isomers, and 3- O -{2- O -{6- O -[P-OH-trans-cinnamoyl]-β-d-glucosyl}-α-rhamnosyl} Kaempferide. The discovery of bioactive compounds could provide references for the quality control and novel pharmaceuticals development of GRE. The present work proposes a feasible chromatogram-bioactivity correlation based approach to discover the compounds and define their bioactivities for the complex multi-component systems.

Non-targeted analysis of unexpected food contaminants using LC-HRMS.

PubMed

Kunzelmann, Marco; Winter, Martin; Åberg, Magnus; Hellenäs, Karl-Erik; Rosén, Johan

2018-03-29

A non-target analysis method for unexpected contaminants in food is described. Many current methods referred to as "non-target" are capable of detecting hundreds or even thousands of contaminants. However, they will typically still miss all other possible contaminants. Instead, a metabolomics approach might be used to obtain "true non-target" analysis. In the present work, such a method was optimized for improved detection capability at low concentrations. The method was evaluated using 19 chemically diverse model compounds spiked into milk samples to mimic unknown contamination. Other milk samples were used as reference samples. All samples were analyzed with UHPLC-TOF-MS (ultra-high-performance liquid chromatography time-of-flight mass spectrometry), using reversed-phase chromatography and electrospray ionization in positive mode. Data evaluation was performed by the software TracMass 2. No target lists of specific compounds were used to search for the contaminants. Instead, the software was used to sort out all features only occurring in the spiked sample data, i.e., the workflow resembled a metabolomics approach. Procedures for chemical identification of peaks were outside the scope of the study. Method, study design, and settings in the software were optimized to minimize manual evaluation and faulty or irrelevant hits and to maximize hit rate of the spiked compounds. A practical detection limit was established at 25 μg/kg. At this concentration, most compounds (17 out of 19) were detected as intact precursor ions, as fragments or as adducts. Only 2 irrelevant hits, probably natural compounds, were obtained. Limitations and possible practical use of the approach are discussed.

Influence of bio-fuels on passenger car vehicle emissions

NASA Astrophysics Data System (ADS)

Petrea, M.; Kapernaum, M.; Wahl, C.

2009-04-01

In order to reduce the emissions of air pollutants, vehicles design and fuel formulation have changed. Ultra clean vehicle technologies started to be used in increased number. As a result, the emissions composition is expected to change as well. The use of new technologies and new fuels require new emissions tests especially for non-regulated compounds. The interest in using bio fuels as alternative fuels for petroleum-based ones has increased constantly in the last years. The advantages of the bio fuels usage is given by their similar proprieties, characteristics of renew ability, biodegradability and potential beneficial effects on the exhaust emission. The study involved measurements on a roller test facility of a reference passenger car representing new technologies (emission standards, injection system). The vehicle operated by use of reference gasoline and reference gasoline blended (10 and 20%) with bio-ethanol (EtOH). The measurements used different driving cycles: ARTEMIS cycle, real world driving cycle, NEDC cycle, the standard European driving cycle and additionally, a driving cycle consisting in Idle, 30, 50, 90 km/h. The sampling positions were before and after the catalyst and in the exhaust pipe. The detailed speciation of NMVOC' (non methane volatile organic compounds) was completed by use of active carbon tubes, DNPH (2,4-dinitrophenylhydrazine) tubes and cold traps. The particles were monitored by use of an on-line EEPS (Engine Exhaust Particle Sizer). CO2, NO, NO2 and NOX (NO +NO2) were continuously monitored by use of an on- line FTIR (Fourier transform infrared spectroscopy)- MEXA system. The investigations reveal that among the carbonylic compounds 15 oxygenated species were found in engine out exhaust and only 3 in tailpipe emissions, namely formaldehyde, acetaldehyde and acroleine. These are of great interest due to their impacts on human health. The hydrocarbons emissions decrease by increased of EtOH content. New compounds were observed. The nitro-compounds found in the after engine position by increased EtOH were no more found in the exhaust gas. The results show that total particle concentration, mass and diameter decreased substantially after catalyst and filter by increased ethanol blend.

Experimental investigation of the auto-ignition characteristics of oxygenated reference fuel compounds

NASA Astrophysics Data System (ADS)

Walton, Stephen Michael

The increased use of biofuels presents an opportunity to improve combustion performance while simultaneously reducing greenhouse gases and pollutant emissions. This work focused on improving the fundamental understanding of the auto-ignition chemistry of oxygenated reference fuel compounds. A systematic study of the effects of ester structure on ignition chemistry was performed using the University of Michigan Rapid Compression Facility. The ignition properties of the ester compounds were investigated over a broad range of pressures (P=5-20 atm) and temperatures (T=850-1150 K) which are directly relevant to advanced combustion engine strategies. Ignition delay times for five esters were determined using the RCF. The esters were selected to systematically consider the chemical structure of the compounds. Three esters were saturated: methyl butanoate, butyl methanoate, and ethyl propanoate; and two were unsaturated: methyl crotonate and methyl trans-3-hexenoate. The unsaturated esters were more reactive than their saturated counterparts, with the largest unsaturated ester, methyl trans-3-hexenoate having the highest reactivity. Two isomers of the saturated esters, butyl methanoate and ethyl propanoate, were more reactive than the isomer methyl butanoate. The results are explained if we assume that butyl methanoate and ethyl propanoate form intermediate ring structures which decompose more rapidly than esters such as methyl butanoate, which do not form ring structures. Modeling studies of the reaction chemistry were conducted for methyl butanoate and ethyl propanoate, for which detailed mechanisms were available in the literature. The new experimental data indicated that literature rate coefficients for some of the methyl butanoate/HO2 reactions were too fast. Modifying these within the theoretical uncertainties for the reaction rates, led to excellent agreement between the model predictions and the experimental data. Comparison of the modeling results with the intermediates measured during methyl butanoate ignition indicated that pathways leading to the formation of small hydrocarbons are relatively well represented in the reaction mechanism. The results of this work provide archival benchmark data for improved understanding of the dominant reaction pathways and species controlling the auto-ignition of oxygenated reference fuel compounds. These data also provide a path for continued development of chemical kinetic models to optimize practical combustion systems.

Encapsulation of bioactive compound from extracted jasmine flower using β-Cyclodextrin via electrospray

NASA Astrophysics Data System (ADS)

Rahmam., S.; Naim., M. N.; Ng., E.; Mokhtar, M. Nn; Abu Bakar, N. F.

2016-06-01

The ability of electrospray to encapsulate the bioactive compound extracted from Jasmine flower with β-Cyclodextrion (β-CD) without any thermal-assisted processing was demonstrated in this study. The extraction of Jasmine compound were conducted using sonicator at 70 000 Hz, for 10 minutes and followed by mixing of the filtered compound with β-CD. Then, the mixture was electrosprayed under a stable Taylor cone jet mode at the voltage of 4 - 5 kV, with flow rate of 0.2 ml/hour. The aluminum substrate that used for collecting the deposit was placed at 30 cm from the needle's tip to allow the occurrence of evaporation and droplet fission until the droplet transform to solid particles. Characteristics of solidified bioactive compound from Jasmine flower (non-encapsulated compound) and solidified bioactive compound with β-CD (encapsulated compound) were studied in this work. From SEM images, it can be observed that the particles size distribution of encapsulated compound deposits have better deposition array and did not aggregate with each other compared to the non-encapsulated compound. FE-SEM images of encapsulated compound deposits indicate more solid crystal looks while non-encapsulated compound was obtained in the porous form. The electrospray process in this work has successfully encapsulated the Jasmine compound with β-CD without any thermal-assisted process. The encapsulation occurrence was determined using FTIR analysis. Identical peaks that referred to the β-CD were found on the encapsulated compound demonstrated that most deposits were encapsulated with β-CD.

Complete Genome Sequence of Acinetobacter baumannii CIP 70.10, a Susceptible Reference Strain for Comparative Genome Analyses.

PubMed

Krahn, Thomas; Wibberg, Daniel; Maus, Irena; Winkler, Anika; Pühler, Alfred; Poirel, Laurent; Schlüter, Andreas

2015-07-30

The complete genome sequence for the reference strain Acinetobacter baumannii CIP 70.10 (ATCC 15151) was established. The strain was isolated in France in 1970, is susceptible to most antimicrobial compounds, and is therefore of importance for comparative genome analyses with clinical multidrug-resistant (MDR) A. baumannii strains to study resistance development and acquisition in this emerging human pathogen. Copyright © 2015 Krahn et al.

Indicators: Acidification

EPA Pesticide Factsheets

Acidification is a broad term that refers to the process by which aquatic ecosystems become more acidic. Acid rain and acid mine drainage are major sources of acidifying compounds, lowering the pH below the range where most living organisms function.

Genetics Home Reference: hereditary paraganglioma-pheochromocytoma

MedlinePlus

... two important cellular pathways called the citric acid cycle (or Krebs cycle) and oxidative phosphorylation. These pathways are critical in ... can use. As part of the citric acid cycle, the SDH enzyme converts a compound called succinate ...

Genetics Home Reference: Langer mesomelic dysplasia

MedlinePlus

... Citation on PubMed Campos-Barros A, Benito-Sanz S, Ross JL, Zinn AR, Heath KE. Compound heterozygosity of ... L, Elder FF, Scott CI Jr, Marttila P, Ross JL. Complete SHOX deficiency causes Langer mesomelic dysplasia. ...

Identification of multiple constituents in the traditional Chinese medicine formula Zhi-zi-chi decoction and rat plasma after oral administration by liquid chromatography coupled to quadrupole time-of-flight tandem mass spectrometry.

PubMed

Zhao, Xu; Long, Zhimin; Dai, Jinna; Bi, Kaishun; Chen, Xiaohui

2012-10-30

Liquid chromatography (LC) coupled to positive electrospray ionization (ESI) tandem mass spectrometry (MS/MS) employing a time-of-flight tandem mass spectrometer was established to identify multi-components of Zhi-zi-chi decoction, a traditional Chinese medicine formula, and the constituents in rat plasma after oral administration of Zhi-zi-chi decoction. The LC separation was achieved on a C(18) column. The mobile phase consisted of acetonitrile/0.2% formic acid with gradient program. The quadrupole time-of-flight (Q-TOF) mass spectrometer was operated in the positive ion mode with an electrospray ionization source (ESI+). The capillary voltage of the ion source was set at 4500 V and the capillary exit was 90 V. The nebulizer pressure was maintained at 1.2 bar. Hexapole radio frequencies 1 and 2 were set to 200 Vpp and 250 Vpp, respectively. A total 47 compounds in the Zhi-zi-chi decoction and 24 constituents in rat plasma after oral administration of Zhi-zi-chi decoction were identified. Of the 47 detected compounds in the Zhi-zi-chi decoction, 15 were identified by comparing the retention time and MS data with that of reference compounds and the rest were identified by MS analysis and retrieving the reference literature. Of the identified 24 compounds in rat plasma, 19 were the original form of the compounds absorbed from the 47 detected compounds, and the other five were the metabolites of the compounds existing in the Zhi-zi-chi decoction. A fast and sensitive LC/Q-TOF MS method has been developed and successfully utilized to screen the active ingredients of a Chinese medical formula, Zhi-zi-chi decoction, for the first time. The results indicated that the 24 compounds identified in rat plasma were the potential active ingredients of Zhi-zi-chi decoction, which provided helpful chemical information for further pharmacology and active mechanism research on Zhi-zi-chi decoction and other traditional Chinese medicines. Copyright © 2012 John Wiley & Sons, Ltd.

Some risk factors for non-Hodgkin's lymphoma.

PubMed

Persson, B; Fredrikson, M

1999-01-01

Non-Hodgkin's lymphoma (NHL) has been subject to several epidemiological studies and various occupational and non-occupational exposures have been identified as determinants. The present study is a pooled analysis of two earlier methodologically similar case-referent studies encompassing 199 cases of NHL and 479 referents, all alive. Exposure information, mainly on occupational agents, was obtained by mailed questionnaires to the subjects. Exposure to white spirits, thinner, and aviation gasoline as well as work as a painter was connected with increased odds ratios, whereas no increased risk was noted for benzene. Farming was associated with a decreased odds ratio and exposure to phenoxy herbicides, wood preservatives, and work as a lumberjack showed increased odds ratios. Moreover, exposure to plastic and rubber chemicals and also contact with some kinds of pets appeared with increased odds ratios. Office employment and housework showed decreased odds ratios. This study indicates the importance of investigating exposures not occurring very frequently in the general population. Solvents were studied as a group of compounds but were also separated into various specific compounds. The present findings suggest that the carcinogenic property of solvents is not only related to the aromatic ones or to the occurrence of benzene contamination, but also to other types of compounds.

Altering the Polymorphic Accessibility of Polycyclic Aromatic Hydrocarbons with Fluorination

DOE PAGES

Hiszpanski, Anna M.; Woll, Arthur R.; Kim, Bumjung; ...

2017-04-25

Here, substituting hydrogen with fluorine is an extensively employed strategy to improve the macroscopic properties of compounds for use in fields as diverse as pharmaceutics and optoelectronics. The role fluorine substitution plays on polymorphism—the ability of a compound to adopt more than one crystal structure—has not been previously studied. Yet, this understanding is important as different polymorphs of the same compound can result in drastically different bulk properties (e.g., solubility, absorptivity, and conductivity). Strategies to either promote or suppress the crystallization of particular polymorphs are thus desired. Here, we show that substituting hydrogen with fluorine affects the polymorphic behavior ofmore » contorted hexabenzocoronene (cHBC). A polycyclic aromatic hydrocarbon and molecular semiconductor, cHBC exhibits two polymorphs (i.e., P2 1/c crystal structure which we refer to as polymorph I and a triclinic crystal structure which we refer to as polymorph II) that are accessible through postdeposition processing of amorphous films. While the same two polymorphs remain accessible in fluorinated derivatives of cHBC, fluorination appears to favor the formation of polymorph I, with progressively smaller energy barrier for transformation from polymorph II to polymorph I with fluorination.« less

Altering the Polymorphic Accessibility of Polycyclic Aromatic Hydrocarbons with Fluorination

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

Hiszpanski, Anna M.; Woll, Arthur R.; Kim, Bumjung

Here, substituting hydrogen with fluorine is an extensively employed strategy to improve the macroscopic properties of compounds for use in fields as diverse as pharmaceutics and optoelectronics. The role fluorine substitution plays on polymorphism—the ability of a compound to adopt more than one crystal structure—has not been previously studied. Yet, this understanding is important as different polymorphs of the same compound can result in drastically different bulk properties (e.g., solubility, absorptivity, and conductivity). Strategies to either promote or suppress the crystallization of particular polymorphs are thus desired. Here, we show that substituting hydrogen with fluorine affects the polymorphic behavior ofmore » contorted hexabenzocoronene (cHBC). A polycyclic aromatic hydrocarbon and molecular semiconductor, cHBC exhibits two polymorphs (i.e., P2 1/c crystal structure which we refer to as polymorph I and a triclinic crystal structure which we refer to as polymorph II) that are accessible through postdeposition processing of amorphous films. While the same two polymorphs remain accessible in fluorinated derivatives of cHBC, fluorination appears to favor the formation of polymorph I, with progressively smaller energy barrier for transformation from polymorph II to polymorph I with fluorination.« less

Space Shuttle reaction control system thruster metal nitrate removal and characterization

NASA Technical Reports Server (NTRS)

Saulsberry, R. L.; Mccartney, P. A.

1993-01-01

The Space Shuttle hypergolic primary reaction control system (PRCS) thrusters continue to fail-leak or fail-off at a rate of approximately 1.5 per flight, attributed primarily to metal nitrate formation in the nitrogen tetroxide (N2O4) pilot operated valves (POV's). The failures have continued despite ground support equipment (GSE) and subsystem operational improvements. As a result, the Johnson Space Center (JSC) White Sands Test Facility (WSTF) performed a study to characterize the contamination in the N204 valves. This study prompted the development and implementation of a highly successful flushing technique using deionized (DI) water and gaseous nitrogen (GN2) to remove the contamination while minimizing Teflon seat damage. Following flushing a comprehensive acceptance test is performed before the thruster is deemed recovered. Between the time WSTF was certified to process flight thrusters (March 1992) and September 1993, a 68 percent thruster recovery rate was achieved. The contamination flushed from these thrusters was analyzed and has provided insight into the corrosion process, which is reported in this publication. Additionally, the long-term performance of 24 flushed thrusters installed in the WSTF Fleet Leader Shuttle reaction control subsystem (RCS) test articles is being assessed. WSTF continues to flush flight and test article thrusters and compile data to investigate metal nitrate formation characteristics in leaking and nonleaking valves.

Robust Entrainment of Circadian Oscillators Requires Specific Phase Response Curves

PubMed Central

Pfeuty, Benjamin; Thommen, Quentin; Lefranc, Marc

2011-01-01

The circadian clocks keeping time in many living organisms rely on self-sustained biochemical oscillations entrained by external cues, such as light, to the 24-h cycle induced by Earth's rotation. However, environmental cues are unreliable due to the variability of habitats, weather conditions, or cue-sensing mechanisms among individuals. A tempting hypothesis is that circadian clocks have evolved so as to be robust to fluctuations in the signal that entrains them. To support this hypothesis, we analyze the synchronization behavior of weakly and periodically forced oscillators in terms of their phase response curve (PRC), which measures phase changes induced by a perturbation applied at different times of the cycle. We establish a general relationship between the robustness of key entrainment properties, such as stability and oscillator phase, on the one hand, and the shape of the PRC as characterized by a specific curvature or the existence of a dead zone, on the other hand. The criteria obtained are applied to computational models of circadian clocks and account for the disparate robustness properties of various forcing schemes. Finally, the analysis of PRCs measured experimentally in several organisms strongly suggests a case of convergent evolution toward an optimal strategy for maintaining a clock that is accurate and robust to environmental fluctuations. PMID:21641300

An emerging cyberinfrastructure for biodefense pathogen and pathogen-host data.

PubMed

Zhang, C; Crasta, O; Cammer, S; Will, R; Kenyon, R; Sullivan, D; Yu, Q; Sun, W; Jha, R; Liu, D; Xue, T; Zhang, Y; Moore, M; McGarvey, P; Huang, H; Chen, Y; Zhang, J; Mazumder, R; Wu, C; Sobral, B

2008-01-01

The NIAID-funded Biodefense Proteomics Resource Center (RC) provides storage, dissemination, visualization and analysis capabilities for the experimental data deposited by seven Proteomics Research Centers (PRCs). The data and its publication is to support researchers working to discover candidates for the next generation of vaccines, therapeutics and diagnostics against NIAID's Category A, B and C priority pathogens. The data includes transcriptional profiles, protein profiles, protein structural data and host-pathogen protein interactions, in the context of the pathogen life cycle in vivo and in vitro. The database has stored and supported host or pathogen data derived from Bacillus, Brucella, Cryptosporidium, Salmonella, SARS, Toxoplasma, Vibrio and Yersinia, human tissue libraries, and mouse macrophages. These publicly available data cover diverse data types such as mass spectrometry, yeast two-hybrid (Y2H), gene expression profiles, X-ray and NMR determined protein structures and protein expression clones. The growing database covers over 23 000 unique genes/proteins from different experiments and organisms. All of the genes/proteins are annotated and integrated across experiments using UniProt Knowledgebase (UniProtKB) accession numbers. The web-interface for the database enables searching, querying and downloading at the level of experiment, group and individual gene(s)/protein(s) via UniProtKB accession numbers or protein function keywords. The system is accessible at http://www.proteomicsresource.org/.

Anticipated synchronization in neuronal circuits unveiled by a phase-response-curve analysis

NASA Astrophysics Data System (ADS)

Matias, Fernanda S.; Carelli, Pedro V.; Mirasso, Claudio R.; Copelli, Mauro

2017-05-01

Anticipated synchronization (AS) is a counterintuitive behavior that has been observed in several systems. When AS occurs in a sender-receiver configuration, the latter can predict the future dynamics of the former for certain parameter values. In particular, in neuroscience AS was proposed to explain the apparent discrepancy between information flow and time lag in the cortical activity recorded in monkeys. Despite its success, a clear understanding of the mechanisms yielding AS in neuronal circuits is still missing. Here we use the well-known phase-response-curve (PRC) approach to study the prototypical sender-receiver-interneuron neuronal motif. Our aim is to better understand how the transitions between delayed to anticipated synchronization and anticipated synchronization to phase-drift regimes occur. We construct a map based on the PRC method to predict the phase-locking regimes and their stability. We find that a PRC function of two variables, accounting simultaneously for the inputs from sender and interneuron into the receiver, is essential to reproduce the numerical results obtained using a Hodgkin-Huxley model for the neurons. On the contrary, the typical approximation that considers a sum of two independent single-variable PRCs fails for intermediate to high values of the inhibitory coupling strength of the interneuron. In particular, it loses the delayed-synchronization to anticipated-synchronization transition.

A multi-disciplinary approach to the removal of emerging contaminants in municipal wastewater treatment plants in New York state (2003-2004)

USGS Publications Warehouse

Philips, Patrick J.; Stinson, Beverley; Zaugg, Steven D.; Furlong, Edward T.; Kolpin, Dana W.; Esposito, Kathleen; Bodniewicz, B.; Pape, R.; Anderson, J.

2008-01-01

Across the United States, there is a rapidly growing awareness of the occurrence and the toxicological impacts of natural and synthetic trace compounds in the environment. These trace compounds, referred to as emerging contaminants (ECs), are reported to cause a range of negative impacts in the environment, such as adverse effects on biota in receiving streams and interference with the normal functions of the endocrine system, which controls growth and development in living organisms.

Algae as promising organisms for environment and health

PubMed Central

2011-01-01

Algae, like other plants, produce a variety of remarkable compounds collectively referred to as secondary metabolites. They are synthesized by these organisms at the end of the growth phase and/or due to metabolic alterations induced by environmental stress conditions. Carotenoids, phenolic compounds, phycobiliprotein pigments, polysaccharides and unsaturated fatty acids are same of the algal natural products, which were reported to have variable biological activities, including antioxidant activity, anticancer activity, antimicroabial activity against bacteria-virus-algae-fungi, organic fertilizer and bioremediation potentials. PMID:21862867

The gas-chromatographic and gas-chromatographic-mass-spectrometric identification of halogen-containing organic compounds

NASA Astrophysics Data System (ADS)

Gidaspov, B. V.; Zenkevich, I. G.; Rodin, A. A.

1989-09-01

The problem of identifying halogen-containing organic compounds in their gas-chromatographic and gas-chromatographic-mass-spectrometric (GC-MS) determination in different materials has been examined. Particular attention has been paid not to the complete characterisation of methods for carrying out this analysis but to the most important problem of increasing the selectivity at the stages of sampling, separation, and interpretation of the gas-chromatographic and GC-MS information. The bibliography contains 292 references.

Arbidol: a quarter-century after. Past, present and future of the original Russian antiviral

NASA Astrophysics Data System (ADS)

Balakin, K. V.; Filosa, R.; Lavrenov, S. N.; Mkrtchayn, A. S.; Nawrozkij, M. B.; Novakov, I. A.

2018-06-01

The present review is concerned with the synthesis and structure–activity relationship studies of Arbidol and its structural analogues. The latter are roughly divided into several unequal parts: indole- and benzofuran-based compounds, benzimidazole and imidazopyridine bioisosteres and ring-expanded quinoline derivatives. Much attention is focused on various types of antiviral activity of the above-mentioned Arbidol congeners, as well as of the parent compound itself. Features of Arbidol synthesis and metabolic changes are also discussed. The bibliography includes 166 references.

Chemical and structural order in silicon oxynitrides by methods of surface physics

NASA Astrophysics Data System (ADS)

Finster, J.; Heeg, J.; Klinkenberg, E.-D.

A large number of thin amorphous layers of SiO xN y and several (crystalline) reference compounds (SiO 2, Si 3N 4, Si 2N 2O) are studied. Although XANES and SEXAFS are well sulted to derive structural and chemical order, for these compounds many problems remain to be solved. We show how core level spectra (XPS, AES) can be used to gain such information (e.g. random bonding structure, N coordination, oxidation behaviour).

Evolution in the Lab: Biocide Resistance in E.coli.

ERIC Educational Resources Information Center

Welden, Charles W.; Hossler, Rex A.

2003-01-01

Describes a laboratory experiment on resistance to teach about evolution and issues of misuse of antimicrobial compounds. Investigates Escherichia coli's response to treatment of triclosan, a biocide used in consumer products. (Contains 12 references.) (YDS)

Genetics Home Reference: acatalasemia

MedlinePlus

... oxygen and water. Hydrogen peroxide is produced through chemical reactions within cells. At low levels, it is involved in several chemical signaling pathways, but at high levels it is toxic to cells. ... reactions convert it into compounds called reactive oxygen species ...

To What Extent Can Biogenic SOA Be Controlled?

EPA Science Inventory

Anthropogenic pollution facilitates transformation of naturally emitted volatile organic compounds (VOCs) to the particle phase, enhancing the ambient concentrations of material commonly referred to as biogenic secondary organic aerosol (SOA). It is therefore conceivable that som...

Certified reference material of volatile organic compounds for environmental analysis: BTEX in methanol.

PubMed

Neves, Laura A; Almeida, Renato R R; Rego, Eliane P; Rodrigues, Janaína Marques; de Carvalho, Lucas Junqueira; de M Goulart, Ana Letícia

2015-04-01

The Brazilian Metrology Institute (National Institute of Metrology, Quality, and Technology, Inmetro) has been developing a certified reference material (CRM) of the volatile organic compounds benzene; toluene; ethylbenzene; and ortho, meta, and para-xylenes (BTEX) in methanol, to ensure quality control for environmental-analysis measurements. The objective of this paper is to present the results of certification studies: uncertainty estimates related to characterization, a homogeneity study, and a stability study on a single lot of CRM composed of BTEX in methanol. The method used analysis of variance (ANOVA), a statistical tool, to evaluate the homogeneity and stability of the BTEX CRM, which complies with ISO Guide 30 series. The homogeneity and stability of the BTEX CRM was confirmed for all analytes and their respective properties. All the procedures used in this study complied with ISO GUIDE 34, ISO GUIDE 35, and the guide to the expression of uncertainty of measurement (GUM).

The biomarker guide: Interpreting molecular fossils in petroleum and ancient sediments

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

Peters, K.E.; Moldowan, J.M.

This is a handbook for biomarkers and their application to hydrocarbon exploration and exploitation. The authors aimed this book at a diverse audience, such as students, exploration geologists with a geochemical background, and experts in the field. This is a clear and well written text aimed at the hydrocarbon industry. It is so tightly organized and detailed that it is not an easy read for the novice, though it is a very fine reference book. For those in the field of biomarkers or those who need to refer to a particular compound or process for analyzing biomarkers or have amore » need for a short description of that process or compound, this book will be useful. The text is broken down into 4 chapters: (1) introduction to biological markers, (2) description of the fundamentals of biomarker separation analysis, (3) guidelines for interpretation, and (4) discussion of problem areas and further work.« less

Activity of terbinafine in experimental fungal infections of laboratory animals.

PubMed Central

Petranyi, G; Meingassner, J G; Mieth, H

1987-01-01

The allylamine derivative terbinafine is the first antifungal agent with primary fungicidal properties against dermatophytes which acts systemically after oral application as well as locally after topical application. Comparative oral studies carried out with griseofulvin and ketoconazole in model infections such as guinea pig trichophytosis and microsporosis revealed terbinafine to be superior to the reference compounds both clinically and mycologically. An excellent antimycotic activity of terbinafine was also demonstrable after topical treatment of guinea pig dermatophytoses caused by Trichophyton mentagrophytes or Microsporum canis. Results of comparative chemotherapeutic studies carried out with econazole and tolnaftate demonstrated superior efficacy of terbinafine in the treatment of both trichophytosis and microsporosis. Skin infections of guinea pigs caused by Candida albicans and vaginal candidiasis in rats proved to be responsive to a topical application of terbinafine also. However, the reference compounds, clotrimazole and miconazole, exhibited activity superior to that of terbinafine in both models. PMID:3435103

Comprehensive Review of Applicable Supercritical Fluid Extraction Research

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

Harvey, Scott; Wright, Cherylyn W.; Wright, Bob W.

2001-09-10

This comprehensive supercritical fluid extraction (SFE) literature review is divided into three major sections. The first section describes the electronic literature search details including the abstract service used and the different topics searched. This section also contains an overview of the seven search topics that yielded relevant references along with a brief synopsis of the most significant literature citations. These seven groupings are (1) chemical warfare agents; (2) explosives; (3) hazardous chemicals; (4) poisons, toxins and mycotoxins; (5) toxic (lethal) chemical and toxicants; (6) pesticides in soil; and (7) pesticides from plant and animal tissues. The second section contains tablesmore » of each of these groupings. Each of the seven tables contains entries for individual literature citations listed along with the specific compounds or compound classes that are addressed. The third section refers to the abstracts used in the literature search.« less

In vitro effectiveness of triterpenoids and their synergistic effect with antibiotics against Staphylococcus aureus strains.

PubMed

Hamza, Muhammad; Nadir, Maha; Mehmood, Nadir; Farooq, Adeel

2016-01-01

The aim of this study is to evaluate the effect of four triterpenoids such as oleanolic acid, ursolic acid, cycloastragenol, and beta-boswellic acid alone and in combination with antibiotics against Staphylococcus aureus strains. Sixteen clinical strains of S. aureus from infected wounds were isolated. Eight were methicillin-sensitive S. aureus (MSSA), and the other eight were methicillin-resistant S. aureus (MRSA). The activity was also seen in reference S. aureus American Type Culture Collection ™ strains. The activity of all the triterpenoids and antibiotics against S. aureus was evaluated by broth microdilution method. The effectiveness was judged by comparing the minimum inhibitory concentrations (MICs) of the compounds with antibiotics. The combination of antibiotics with compounds was evaluated by their fractional inhibitory concentrations (FIC). Against both clinical and reference MSSA strains, none of the compounds exhibited comparable activity to antibiotics vancomycin or cefradine except for ursolic acid (MIC 7.8 μg/ml). Against MRSA, all compounds (MIC 16-128 μg/ml) showed lesser activity than vancomycin (MIC 5.8 μg/ml). Among triterpenoid-antibiotic combinations, the most effective were ursolic acid and vancomycin against clinical strain MSSA (FIC S 0.17). However, overall, different combinations between triterpenoids and antibiotics showed 95%-46% ( P < 0.05) reduction in MICs of antibiotics compared to when antibiotics were used alone. Cefradine, a drug not suitable for treating MRSA (MIC = 45 μg/ml), showed a remarkable decrease in its MIC (87% P< 0.01) when it was used in combination with oleanolic acid or ursolic acid in both clinical and reference strains. The tested triterpenoids are relatively weaker than antibiotics. However, when used in combination with antibiotics, they showed remarkable synergistic effect and thus can help in prolonging the viability of these antibiotics against S. aureus infections. Furthermore, reduction in MIC of cefradine with oleanolic acid indicates their potential use against MRSA.

Separation of nitrogen heterocyclic compounds from model coal tar fraction by solvent extraction

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

Kim, S.J.; Chun, Y.J.

2005-07-01

The separation of four kinds of nitrogen heterocyclic compounds (NHCs) from a model mixture comprising NHCs (indole (In), quinoline (Q), iso-quinoline (iQ), quinaldine (Qu)), three kinds of bicyclic aromatic compounds (BACs; 1-methyl-naphthalene (IMN), 2-methyl naphthalene (2MN), dimethylnaphthalene (DMN)), biphenyl (Bp) and phenyl ether (Pe) was examined by a solvent extraction. The model mixture used as a raw material of this work was prepared according to the components and compositions contained in coal tar fraction (the temperature ranges of fraction: 240-265{sup o}C). An aqueous solution of methanol, ethanol, iso-propyl alcohol, N,N-dimethyl acetamide, DMF, formamide, N-methylformamide/methanol, and formamide/methanol were used as solvents.more » An aqueous solution of formamide was found suitable for separating NHCs contained in coal tar fraction based on distribution coefficient and selectivity. The effect of operation factors on separating NHCs was investigated by the distribution equilibrium using an aqueous solution of formamide. Increasing the operation temperature and the volume ratio of solvent to feed at initial (S/F)(o) resulted in improving the distribution coefficients of each NHC, but increasing the volume fraction of water in the solvent at initial (y(w,O)) resulted in deteriorating the distribution coefficients of each NHC. With increasing y(w,O) and (S/F)(o), the selectivities of each NHC in reference to DMN increased. Increase in operation temperature resulted in decrease in selectivities of each NHC in reference to DMN. At an experimental condition fixed, the sequence of the distribution coefficient and selectivity in reference to DMN for each NHC was In {gt} iQ {gt} Q {gt} Qu, and also the sequence of the distribution coefficient for each BAC was IMN {gt} 2MN {gt} DMN. The sequence of the distribution coefficient for entire compounds analyzed by this work was In {gt} iQ {gt} Q {gt} Qu {gt} BP {gt} 1MN {gt} 2MN {gt} Pe {gt} DMN.« less

Connectivity Mapping for Candidate Therapeutics Identification Using Next Generation Sequencing RNA-Seq Data

PubMed Central

McArt, Darragh G.; Dunne, Philip D.; Blayney, Jaine K.; Salto-Tellez, Manuel; Van Schaeybroeck, Sandra; Hamilton, Peter W.; Zhang, Shu-Dong

2013-01-01

The advent of next generation sequencing technologies (NGS) has expanded the area of genomic research, offering high coverage and increased sensitivity over older microarray platforms. Although the current cost of next generation sequencing is still exceeding that of microarray approaches, the rapid advances in NGS will likely make it the platform of choice for future research in differential gene expression. Connectivity mapping is a procedure for examining the connections among diseases, genes and drugs by differential gene expression initially based on microarray technology, with which a large collection of compound-induced reference gene expression profiles have been accumulated. In this work, we aim to test the feasibility of incorporating NGS RNA-Seq data into the current connectivity mapping framework by utilizing the microarray based reference profiles and the construction of a differentially expressed gene signature from a NGS dataset. This would allow for the establishment of connections between the NGS gene signature and those microarray reference profiles, alleviating the associated incurring cost of re-creating drug profiles with NGS technology. We examined the connectivity mapping approach on a publicly available NGS dataset with androgen stimulation of LNCaP cells in order to extract candidate compounds that could inhibit the proliferative phenotype of LNCaP cells and to elucidate their potential in a laboratory setting. In addition, we also analyzed an independent microarray dataset of similar experimental settings. We found a high level of concordance between the top compounds identified using the gene signatures from the two datasets. The nicotine derivative cotinine was returned as the top candidate among the overlapping compounds with potential to suppress this proliferative phenotype. Subsequent lab experiments validated this connectivity mapping hit, showing that cotinine inhibits cell proliferation in an androgen dependent manner. Thus the results in this study suggest a promising prospect of integrating NGS data with connectivity mapping. PMID:23840550

Efficient synthesis of new 2,3-dihydrooxazole-spirooxindoles hybrids as antimicrobial agents.

PubMed

Tiwari, Shailendra; Pathak, Poonam; Sagar, Ram

2016-05-15

Two series of new 2,3-dihydrooxazole-spirooxindole derivatives were efficiently synthesized starting from N'-(2-oxoindolin-3-ylidene) benzohydrazide/N'-(2-oxoindolin-3-ylidene)-2-phenoxyacetohydrazide using designed synthetic route. Newly synthesized 2,3-dihydrooxazole-spirooxindole derivatives were screened for their antibacterial and antifungal activity against different pathogenic strain of bacteria and fungi. The minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC) and minimum fungicidal concentration (MFC) were determined for the test compounds as well as for reference standards. Compounds 4e, 4g, 7g have shown good antibacterial activity whereas compounds 4f, 7b, 7d have displayed better antifungal activity. Copyright © 2016 Elsevier Ltd. All rights reserved.

Design, synthesis and molecular modeling of new 4-phenylcoumarin derivatives as tubulin polymerization inhibitors targeting MCF-7 breast cancer cells.

PubMed

Batran, Rasha Z; Kassem, Asmaa F; Abbas, Eman M H; Elseginy, Samia A; Mounier, Marwa M

2018-07-23

A new set of 4-phenylcoumarin derivatives was designed and synthesized aiming to introduce new tubulin polymerization inhibitors as anti-breast cancer candidates. All the target compounds were evaluated for their cytotoxic effects against MCF-7 cell line, where compounds 2f, 3a, 3b, 3f, 7a and 7b, showed higher cytotoxic effect (IC 50  = 4.3-21.2 μg/mL) than the reference drug doxorubicin (IC 50  = 26.1 μg/mL), additionally, compounds 1 and 6b exhibited the same potency as doxorubicin (IC 50  = 25.2 and 28.0 μg/mL, respectively). The thiazolidinone derivatives 3a, 3b and 3f with potent and selective anticancer effects towards MCF-7 cells (IC 50  = 11.1, 16.7 and 21.2 μg/mL) were further assessed for tubulin polymerization inhibition effects which showed that the three compounds were potent tubulin polymerization suppressors with IC 50 values of 9.37, 2.89 and 6.13 μM, respectively, compared to the reference drug colchicine (IC 50  = 6.93 μM). The mechanistic effects on cell cycle progression and induction of apoptosis in MCF-7 cells were determined for compound 3a due to its potent and selective cytotoxic effects in addition to its promising tubulin polymerization inhibition potency. The results revealed that compound 3a induced cell cycle cessation at G2/M phase and accumulation of cells in pre-G1 phase and prevented its mitotic cycle, in addition to its activation of caspase-7 mediating apoptosis of MCF-7 cells. Molecular modeling studies for compounds 3a, 3b and 3f were carried out on tubulin crystallography, the results indicated that the compounds showed binding mode similar to the co-crystalized ligand; colchicine. Moreover, pharmacophore constructed models and docking studies revealed that thiazolidinone, acetamide and coumarin moieties are crucial for the activity. Molecular dynamics (MD) studies were carried out for the three compounds over 100 ps. MD results of compound 3a showed that it reached the stable state after 30 ps which was in agreement with the calculated potential and kinetic energy of compound 3a. Copyright © 2018 Elsevier Ltd. All rights reserved.

Phase Transition Enthalpy Measurements of Organic and Organometallic Compounds. Sublimation, Vaporization and Fusion Enthalpies From 1880 to 2015. Part 1. C1 - C10

NASA Astrophysics Data System (ADS)

Acree, William; Chickos, James S.

2016-09-01

A compendium of phase change enthalpies published in 2010 is updated to include the period 1880-2015. Phase change enthalpies including fusion, vaporization, and sublimation enthalpies are included for organic, organometallic, and a few inorganic compounds. Part 1 of this compendium includes organic compounds from C1 to C10. Part 2 of this compendium, to be published separately, will include organic and organometallic compounds from C11 to C192. Sufficient data are presently available to permit thermodynamic cycles to be constructed as an independent means of evaluating the reliability of the data. Temperature adjustments of phase change enthalpies from the temperature of measurement to the standard reference temperature, T = 298.15 K, and a protocol for doing so are briefly discussed.

A novel molecular index for secondary oil migration distance

PubMed Central

Zhang, Liuping; Li, Maowen; Wang, Yang; Yin, Qing-Zhu; Zhang, Wenzheng

2013-01-01

Determining oil migration distances from source rocks to reservoirs can greatly help in the search for new petroleum accumulations. Concentrations and ratios of polar organic compounds are known to change due to preferential sorption of these compounds in migrating oils onto immobile mineral surfaces. However, these compounds cannot be directly used as proxies for oil migration distances because of the influence of source variability. Here we show that for each source facies, the ratio of the concentration of a select polar organic compound to its initial concentration at a reference point is independent of source variability and correlates solely with migration distance from source rock to reservoir. Case studies serve to demonstrate that this new index provides a valid solution for determining source-reservoir distance and could lead to many applications in fundamental and applied petroleum geoscience studies. PMID:23965930

Decomposition of the compound Atwood machine

NASA Astrophysics Data System (ADS)

Lopes Coelho, R.

2017-11-01

Non-standard solving strategies for the compound Atwood machine problem have been proposed. The present strategy is based on a very simple idea. Taking an Atwood machine and replacing one of its bodies by another Atwood machine, we have a compound machine. As this operation can be repeated, we can construct any compound Atwood machine. This rule of construction is transferred to a mathematical model, whereby the equations of motion are obtained. The only difference between the machine and its model is that instead of pulleys and bodies, we have reference frames that move solidarily with these objects. This model provides us with the accelerations in the non-inertial frames of the bodies, which we will use to obtain the equations of motion. This approach to the problem will be justified by the Lagrange method and exemplified by machines with six and eight bodies.

Assessment of a robust model protocol with accelerated throughput for a human recombinant full length estrogen receptor-alpha binding assay: protocol optimization and intralaboratory assay performance as initial steps towards validation.

PubMed

Freyberger, Alexius; Wilson, Vickie; Weimer, Marc; Tan, Shirlee; Tran, Hoai-Son; Ahr, Hans-Jürgen

2010-08-01

Despite about two decades of research in the field of endocrine active compounds, still no validated human recombinant (hr) estrogen receptor-alpha (ERalpha) binding assay is available, although hr-ERalpha is available from several sources. In a joint effort, US EPA and Bayer Schering Pharma with funding from the EU-sponsored 6th framework project, ReProTect, developed a model protocol for such a binding assay. Important features of this assay are the use of a full length hr-ERalpha and performance in a 96-well plate format. A full length hr-ERalpha was chosen, as it was considered to provide the most accurate and human-relevant results, whereas truncated receptors could perform differently. Besides three reference compounds [17beta-estradiol, norethynodrel, dibutylphthalate] nine test compounds with different affinities for the ERalpha [diethylstilbestrol (DES), ethynylestradiol, meso-hexestrol, equol, genistein, o,p'-DDT, nonylphenol, n-butylparaben, and corticosterone] were used to explore the performance of the assay. Three independent experiments per compound were performed on different days, and dilutions of test compounds from deep-frozen stocks, solutions of radiolabeled ligand and receptor preparation were freshly prepared for each experiment. The ERalpha binding properties of reference and test compounds were well detected. As expected dibutylphthalate and corticosterone were non-binders in this assay. In terms of the relative ranking of binding affinities, there was good agreement with published data obtained from experiments using a human recombinant ERalpha ligand binding domain. Irrespective of the chemical nature of the compound, individual IC(50)-values for a given compound varied by not more than a factor of 2.5. Our data demonstrate that the assay was robust and reliably ranked compounds with strong, weak, and no affinity for the ERalpha with high accuracy. It avoids the manipulation and use of animals, i.e., the preparation of uterine cytosol as receptor source from ovariectomized rats, as a recombinant protein is used and thus contributes to the 3R concept (reduce, replace, and refine). Furthermore, in contrast to other assays, this assay could be adjusted to an intermediate/high throughput format. On the whole, this assay is a promising candidate for further validation. Copyright 2010 Elsevier Inc. All rights reserved.

Precursor ion scanning-mass spectrometry for the determination of nitro functional groups in atmospheric particulate organic matter.

PubMed

Dron, Julien; Abidi, Ehgere; Haddad, Imad El; Marchand, Nicolas; Wortham, Henri

2008-06-23

An analytical method for the quantitative determination of the total nitro functional group (R-NO2) content in atmospheric particulate organic matter is developed. The method is based on the selectivity of NO2(-) (m/z 46) precursor ion scanning (PAR 46) by atmospheric pressure chemical ionization-tandem mass spectrometry (APCI-MS/MS). PAR 46 was experimented on 16 nitro compounds of different molecular structures and was compared with a neutral loss of NO (30 amu) technique in terms of sensitivity and efficiency to characterize the nitro functional groups. Covering a wider range of compounds, PAR 46 was preferred and applied to reference mixtures containing all the 16 compounds under study. Repeatability carried out using an original statistical approach, and calibration experiments were performed on the reference mixtures proven the suitability of the technique for quantitative measurements of nitro functional groups in samples of environmental interest with good accuracy. A linear range was obtained for concentrations ranging between 0.005 and 0.25 mM with a detection limit of 0.001 mM of nitro functional groups. Finally, the analytical error based on an original statistical approach applied to numerous reference mixtures was below 20%. Despite of potential artifacts related to nitro-alkanes and organonitrates, this new methodology offers a promising alternative to FT-IR measurements. The relevance of the method and its potentialities are demonstrated through its application to aerosols collected in the EUPHORE simulation chamber during o-xylene photooxidation experiments and in a suburban area of a French alpine valley during summer.

Headspace solid phase microextraction--GC/C-IRMS for delta13CVPDB measurements of mono-aromatic hydrocarbons using EA-IRMS calibration.

PubMed

Ebongué, Véronique Woule; Geypens, Benny; Berglund, Michael; Taylor, Philip

2009-03-01

This work aims at comparing the delta(13)C(VPDB) of mono-aromatic hydrocarbons benzene, toluene, ethylbenzene and xylene isomers (BTEX) measured by elemental analyser (EA)-isotope ratio mass spectrometer (IRMS) with the delta(13)C(VPDB) measured on the same compounds by headspace solid phase microextraction - GC/C-IRMS (hSPME - GC/C-IRMS) with the final goal of using these compounds as internal standards on the latter system. The EA-IRMS measurements were done using calcium and lithium carbonate isotopic reference materials: NBS19 and L-SVEC for establishing the delta(13)C(VPDB) scale. The EA-IRMS measurements with helium dilution of a set of five reference materials (USGS40, USGS41, IAEA-CH-6, IAEA-CH-3 and IAEA-601) show systematic bias of 1 per thousand relative to their assigned values. This bias due to the dilution mechanism in the used ConfloII interface device could not be avoided. As the selected hydrocarbons: BTEX could not be analysed by EA-IRMS without helium dilution, their delta(13)C(VPDB) must be corrected from this observed bias using an external calibration. The CO(2) gas calibrated using EA-IRMS without helium dilution, was used as an in-house reference for the delta(13)C(VPDB) measurements of the BTEX by the hSPME - GC/C-IRMS system. The comparison made between the delta(13)C(VPDB) measured on the same BTEX compounds by EA-IRMS (with external calibration) and by hSPME - GC/C-IRMS techniques showed good agreement.

Keto-acids in Carbonaceous Meteorites

NASA Technical Reports Server (NTRS)

Cooper, G.; Chang, P. M.; Dugas, A.; Byrd, A.; Chang, P. M.; Washington, N.

2005-01-01

The Murchison and Murray meteorites are the best-characterized carbonaceous meteorites with respect to organic chemistry and are generally used as references for organic compounds in extraterrestrial material. Among the classes of organic compounds found in these meteorites are amino acids, carboxylic acids, hydroxy acids, purines, and pyrimidines. Such compounds, important in contemporary biochemistry, are thought to have been delivered to the early Earth in asteroids and comets and may have played a role in early life and/or the origin of life. Absent among (today's) critically important biological compounds reported in carbonaceous meteorites are keto acids, i.e., pyruvic acid, acetoacetic acid, and higher homologs. These compounds are key intermediates in such critical processes as glycolysis and the citric acid cycle. In this study several individual meteoritic keto acids were identified by gas chromatography-mass spectrometry (GC-MS) (see figure below). All compounds were identified as their trimethylsilyl (TMS), isopropyl ester (ISP), and tert-butyldimethylsilyl (tBDMS) derivatives. In general, the compounds follow the abiotic synthesis pattern of other known meteorite classes of organic compounds [1,2]: a general decrease in abundance with increasing carbon number within a class of compounds and many, if not all, possible isomers present at a given carbon number. The majority of the shown compounds was positively identified by comparison of their mass spectra to commercially available standards or synthesized standards.

Identification of volatile compounds in codfish ( Gadus) by a combination of two extraction Methods coupled with GC-MS analysis

NASA Astrophysics Data System (ADS)

Chang, Yufei; Hou, Hu; Li, Bafang

2016-06-01

Codfish is a kind of abyssal fish species with a great value in food industry. However, the flavor of codfish, especially the unpleasant odor, has caused serious problems in its processing. To accurately identify the volatile compounds in codfish, a combination of solid phase micro-extraction (SPME) method and simultaneous distillation extraction (SDE) method was used to extract the volatiles. Gas chromatography-mass spectrometry (GC-MS) along with Kovats indices (KI) and authentic standard compounds were used to identify the volatiles. The results showed that a total of 86 volatile compounds were identified in codfish, of them 24 were extracted by SDE, 69 compounds by SPME, and 10 compounds by both SDE and SPME. Seventy volatile compounds were found to have specific odors, of them 7 typical compounds contributed significantly to the flavor of codfish. Alcohols ( i.e., (E)-2-penten-1-ol and 2-octanol), esters ( i.e., ethyl butyrate and methyl geranate), aldehydes ( i.e., 2-dodecenal and pentadecanal) contributed the most to fresh flavor while nitrogen compounds, sulphur compounds, furans, as well as some ketones ( i.e., 2-hydroxy-3-pentanone) brought unpleasant odor, such as fishy and earthy odor. It was indicated that the combination of multiple extraction methods and GC-MS analysis can enhance the accuracy of identification, and provide a reference for the further study on flavor of aquatic products.

Multivariate approaches for stability control of the olive oil reference materials for sensory analysis - part II: applications.

PubMed

Valverde-Som, Lucia; Ruiz-Samblás, Cristina; Rodríguez-García, Francisco P; Cuadros-Rodríguez, Luis

2018-02-09

The organoleptic quality of virgin olive oil depends on positive and negative sensory attributes. These attributes are related to volatile organic compounds and phenolic compounds that represent the aroma and taste (flavour) of the virgin olive oil. The flavour is the characteristic that can be measured by a taster panel. However, as for any analytical measuring device, the tasters, individually, and the panel, as a whole, should be harmonized and validated and proper olive oil standards are needed. In the present study, multivariate approaches are put into practice in addition to the rules to build a multivariate control chart from chromatographic volatile fingerprinting and chemometrics. Fingerprinting techniques provide analytical information without identify and quantify the analytes. This methodology is used to monitor the stability of sensory reference materials. The similarity indices have been calculated to build multivariate control chart with two olive oils certified reference materials that have been used as examples to monitor their stabilities. This methodology with chromatographic data could be applied in parallel with the 'panel test' sensory method to reduce the work of sensory analysis. © 2018 Society of Chemical Industry. © 2018 Society of Chemical Industry.

A regression model for calculating the second dimension retention index in comprehensive two-dimensional gas chromatography time-of-flight mass spectrometry.

PubMed

Wang, Bing; Shen, Hao; Fang, Aiqin; Huang, De-Shuang; Jiang, Changjun; Zhang, Jun; Chen, Peng

2016-06-17

Comprehensive two-dimensional gas chromatography time-of-flight mass spectrometry (GC×GC/TOF-MS) system has become a key analytical technology in high-throughput analysis. Retention index has been approved to be helpful for compound identification in one-dimensional gas chromatography, which is also true for two-dimensional gas chromatography. In this work, a novel regression model was proposed for calculating the second dimension retention index of target components where n-alkanes were used as reference compounds. This model was developed to depict the relationship among adjusted second dimension retention time, temperature of the second dimension column and carbon number of n-alkanes by an exponential nonlinear function with only five parameters. Three different criteria were introduced to find the optimal values of parameters. The performance of this model was evaluated using experimental data of n-alkanes (C7-C31) at 24 temperatures which can cover all 0-6s adjusted retention time area. The experimental results show that the mean relative error between predicted adjusted retention time and experimental data of n-alkanes was only 2%. Furthermore, our proposed model demonstrates a good extrapolation capability for predicting adjusted retention time of target compounds which located out of the range of the reference compounds in the second dimension adjusted retention time space. Our work shows the deviation was less than 9 retention index units (iu) while the number of alkanes were added up to 5. The performance of our proposed model has also been demonstrated by analyzing a mixture of compounds in temperature programmed experiments. Copyright © 2016 Elsevier B.V. All rights reserved.

Development of a NIST standard reference material containing thirty volatile organic compounds at 5 nmol/mol in nitrogen.

PubMed

Rhoderick, George C; Yen, James H

2006-05-01

Primary gravimetric gas cylinder standards containing 30 volatile organic compounds (VOCs) in nitrogen were prepared using a procedure previously developed to prepare gas mixture cylinder standards of VOCs at the 5 nmol/mol level. This set of primary standards was intercompared to existing gas cylinder standards, containing as many as 19 of the 30 volatile organics present in these new primaries, using gas chromatography with a hydrogen flame ionization detector coupled with cryogenic preconcentration. The linear regression analysis showed excellent agreement among the standards for each compound. Similar mixtures containing many of these compounds in treated aluminum gas cylinders have been evaluated over time and have shown stability for as much as 10 years. The development of these 30-component primary standards led to the preparation and certification of a reissue of Standard Reference Material (SRM) 1804 at the nominal amount-of-substance fraction of 5 nmol/mol for each analyte. A lot of 20 cylinders containing the mixture was prepared at NIST following previously demonstrated protocols for preparation of the cylinders. Each cylinder was analyzed against one cylinder from the lot, designated as the "lot standard," for each of the 30 compounds. As a result of the uncertainty analysis, the data showed that rather than declaring the lot homogeneous with a much higher uncertainty, each cylinder could be individually certified. The expanded uncertainty limits ranged from 1.5 to 10% for 28 of the 30 analytes, with two of the analytes having uncertainties as high as 19% in those SRM cylinders certified. Due to stability issues and some high uncertainties for a few analytes in 2 of the samples, 18 of the 20 candidate SRM samples were certified. These volatile organic gas mixtures represent the most complex gas SRMs developed at NIST.

Targeting natural compounds against HER2 kinase domain as potential anticancer drugs applying pharmacophore based molecular modelling approaches.

PubMed

Rampogu, Shailima; Son, Minky; Baek, Ayoung; Park, Chanin; Rana, Rabia Mukthar; Zeb, Amir; Parameswaran, Saravanan; Lee, Keun Woo

2018-04-20

Human epidermal growth factor receptors are implicated in several types of cancers characterized by aberrant signal transduction. This family comprises of EGFR (ErbB1), HER2 (ErbB2, HER2/neu), HER3 (ErbB3), and HER4 (ErbB4). Amongst them, HER2 is associated with breast cancer and is one of the most valuable targets in addressing the breast cancer incidences. For the current investigation, we have performed 3D-QSAR based pharmacophore search for the identification of potential inhibitors against the kinase domain of HER2 protein. Correspondingly, a pharmacophore model, Hypo1, with four features was generated and was validated employing Fischer's randomization, test set method and the decoy test method. The validated pharmacophore was allowed to screen the colossal natural compounds database (UNPD). Subsequently, the identified 33 compounds were docked into the proteins active site along with the reference after subjecting them to ADMET and Lipinski's Rule of Five (RoF) employing the CDOCKER implemented on the Discovery Studio. The compounds that have displayed higher dock scores than the reference compound were scrutinized for interactions with the key residues and were escalated to MD simulations. Additionally, molecular dynamics simulations performed by GROMACS have rendered stable root mean square deviation values, radius of gyration and potential energy values. Eventually, based upon the molecular dock score, interactions between the ligands and the active site residues and the stable MD results, the number of Hits was culled to two identifying Hit1 and Hit2 has potential leads against HER2 breast cancers. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

Inhibitory effect of 1,2,4-triazole-ciprofloxacin hybrids on Haemophilus parainfluenzae and Haemophilus influenzae biofilm formation in vitro under stationary conditions.

PubMed

Kosikowska, Urszula; Andrzejczuk, Sylwia; Plech, Tomasz; Malm, Anna

2016-10-01

Haemophilus parainfluenzae and Haemophilus influenzae, upper respiratory tract microbiota representatives, are able to colonize natural and artificial surfaces as biofilm. The aim of the present study was to assay the effect of ten 1,2,4-triazole-ciprofloxacin hybrids on planktonic or biofilm-forming haemophili cells in vitro under stationary conditions on the basis of MICs (minimal inhibitory concentrations) and MBICs (minimal biofilm inhibitory concentrations). In addition, anti-adhesive properties of these compounds were examined. The reference strains of H. parainfluenzae and H. influenzae were included. The broth microdilution microtiter plate (MTP) method with twofold dilution of the compounds, or ciprofloxacin (reference agent) in 96-well polystyrene microplates, was used. The optical density (OD) reading was made spectrophotometrically at a wavelength of 570 nm (OD570) both to measure bacterial growth and to detect biofilm-forming cells under the same conditions with 0.1% crystal violet. The following values of parameters were estimated for 1,2,4-triazole-ciprofloxacin hybrids - MIC = 0.03-15.63 mg/L, MBIC = 0.03-15.63 mg/L, MBIC/MIC = 0.125-8, depending on the compound, and for ciprofloxacin - MIC = 0.03-0.06 mg/L, MBIC = 0.03-0.12 mg/L, MBIC/MIC = 1-2. The observed strong anti-adhesive properties (95-100% inhibition) of the tested compounds were reversible during long-term incubation at subinhibitory concentrations. Thus, 1,2,4-triazole-ciprofloxacin hybrids may be considered as starting compounds for designing improved agents not only against planktonic but also against biofilm-forming Haemophilus spp. cells. Copyright © 2016 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

Two generators to produce SI-traceable reference gas mixtures for reactive compounds at atmospheric levels

NASA Astrophysics Data System (ADS)

Pascale, C.; Guillevic, M.; Ackermann, A.; Leuenberger, D.; Niederhauser, B.

2017-12-01

To answer the needs of air quality and climate monitoring networks, two new gas generators were developed and manufactured at METAS in order to dynamically generate SI-traceable reference gas mixtures for reactive compounds at atmospheric concentrations. The technical features of the transportable generators allow for the realization of such gas standards for reactive compounds (e.g. NO2, volatile organic compounds) in the nmol · mol-1 range (ReGaS2), and fluorinated gases in the pmol ṡ mol-1 range (ReGaS3). The generation method is based on permeation and dynamic dilution. The transportable generators have multiple individual permeation chambers allowing for the generation of mixtures containing up to five different compounds. This mixture is then diluted using mass flow controllers, thus making the production process adaptable to generate the required amount of substance fraction. All parts of ReGaS2 in contact with the gas mixture are coated to reduce adsorption/desorption processes. Each input parameter required to calculate the generated amount of substance fraction is calibrated with SI-primary standards. The stability and reproducibility of the generated amount of substance fractions were tested with NO2 for ReGaS2 and HFC-125 for ReGaS3. They demonstrate stability over 1-4 d better than 0.4% and 0.8%, respectively, and reproducibility better than 0.7% and 1%, respectively. Finally, the relative expanded uncertainty of the generated amount of substance fraction is smaller than 3% with the major contributions coming from the uncertainty of the permeation rate and/or of the purity of the matrix gas. These relative expanded uncertainties meet then the needs of the data quality objectives fixed by the World Meteorological Organization.

The constituents of Cibotium barometz and their permeability in the human Caco-2 monolayer cell model.

PubMed

Wu, Qi; Yang, Xiu-Wei

2009-09-25

Cibotium barometz (L.) J. Sm. (Dicksoniaceae) has been traditionally used as anti-inflammatory and anodyne. To investigate the constituents in the rhizomes of Cibotium barometz, and evaluate their permeability in the human Caco-2 model. The rhizomes extracts of Cibotium barometz were isolated by chromatographic techniques. Structures of isolated compounds were identified by spectroscopic methods. The permeability of the main constituents was evaluated using human Caco-2 cell monolayer as a model system. Three unusual sesquiterpenes having 1-indanone nucleus (1, 3 and 4) and an unusual orthoester spiropyranosyl derivative of protocatechuic acid (2) were isolated from the rhizomes of Cibotium barometz. Among these, the bilateral permeation of 1, 3 and 4 in Caco-2 model was examined. The apparent permeability coefficients (P(app)) of 1 was identical with those of propranolol, which is often used as reference standard of high permeability. The P(app) values of 3 and 4 were in agreement with those of atenolol, which is often used as reference standard of poor permeability. The permeation rates of 1, 3 and 4 increased linearly as a function of time up to 180 min and with the concentration within the test range of 25-200 microM. This is the first report on the presence of compounds 2 and 3 in this plant and 4 was a new compound. Compound 1 is assigned for a well-absorbed, and 2 and 3 are assigned for the poorly absorbed compounds in human intestine. A passive diffusion mechanism for transport of 1, 3 and 4 in Caco-2 model was proposed. The results provided some useful information for predicting the oral bioavailability of 1, 3 and 4.

ECONOMIC GROWTH ANALYSIS SYSTEM: REFERENCE MANUAL

EPA Science Inventory

The two-volume report describes the development of, and provides information needed to operate, a prototype Economic Growth Analysis System (E-GAS) modeling system. The model will be used to project emissions inventories of volatile organic compounds (VOCs), oxides of nitrogen (...

Design, synthesis and biological evaluation of berberine-benzimidazole hybrids as new type of potentially DNA-targeting antimicrobial agents.

PubMed

Jeyakkumar, Ponmani; Zhang, Ling; Avula, Srinivasa Rao; Zhou, Cheng-He

2016-10-21

A series of novel berberine-benzimidazole derivatives were conveniently and efficiently synthesized and characterized by NMR, IR, MS and HRMS spectra. Most of the prepared compounds showed effective antimicrobial activities in contrast with clinical norfloxacin, chloromycin and fluconazole. Especially, compound 5d exhibited good anti-MRSA, anti-Escherichia coli, and anti-Salmonella typhi activity with low MIC values of 2-8 μg/mL, which were comparable or even superior to reference drugs. The preliminarily interactive investigation revealed that the most active compound 5d could effectively intercalate into DNA to form 5d-DNA complex and cleavage DNA by agarose gel electrophoresis experiments. It was also found that compound 5d was able to efficiently permeabilize the membranes of both Gram-positive (MRSA) and Gram-negative (E. coli DH52) bacteria. Experiments and molecular docking both showed that human serum albumin (HSA) could effectively transport compound 5d and hydrophobic interactions and hydrogen bonds play important roles in the association of compound 5d with HSA. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

A case study on the influences of long-range transport to Taiwan`s acid deposition using Taiwan air quality model

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

Ken-Hui Chang; Fu-Tien Jeng

1996-12-31

The long-range and transboundary transport of precursors of add deposition in East Asia became important due to the industrial development around this area. We started to develop Taiwan Air Quality Model (TAQM) system since 1992, which is based on regional Acid Deposition Model (RADM) system. A typical episode in Mei-Yu season has been selected to study. A case considering all emissions within simulated domain has been run as a reference case, and another perturbed case, not including Taiwan`s emission, has been also run for analyzing quantitatively the influence of long-range transport to Taiwan`s wet deposition during the episode are 31%more » and 24% for total sulfur compounds and total nitrogen compounds respectively; but for dry deposition, only 6% is contributed by long range transport for sulfur compounds and 29% for total nitrogen compounds. Therefore, the percentages of total acid deposition contributed by long-range transport are 27% and 25% for total sulfur compounds and total nitrogen compounds, respectively.« less

New insights into highly potent tyrosinase inhibitors based on 3-heteroarylcoumarins: Anti-melanogenesis and antioxidant activities, and computational molecular modeling studies.

PubMed

Pintus, Francesca; Matos, Maria J; Vilar, Santiago; Hripcsak, George; Varela, Carla; Uriarte, Eugenio; Santana, Lourdes; Borges, Fernanda; Medda, Rosaria; Di Petrillo, Amalia; Era, Benedetta; Fais, Antonella

2017-03-01

Melanogenesis is a physiological pathway for the formation of melanin. Tyrosinase catalyzes the first step of this process and down-regulation of its activity is responsible for the inhibition of melanogenesis. The search for molecules capable of controlling hyperpigmentation is a trend topic in health and cosmetics. A series of heteroarylcoumarins have been synthesized and evaluated. Compounds 4 and 8 exhibited higher tyrosinase inhibitory activities (IC 50 =0.15 and 0.38μM, respectively), than the reference compound, kojic acid (IC 50 =17.9μM). Compound 4 acts as competitive, while compound 8 as uncompetitive inhibitor of mushroom tyrosinase. Furthermore, compounds 2 and 8 inhibited tyrosinase activity and melanin production in B16F10 cells. In addition, compounds 2-4 and 8 proved to have an interesting antioxidant profile in both ABTS and DPPH radicals scavenging assays. Docking experiments were carried out in order to study the interactions between these heteroarylcoumarins and mushroom tyrosinase. Copyright © 2017 Elsevier Ltd. All rights reserved.

The low/high BCS permeability class boundary: physicochemical comparison of metoprolol and labetalol.

PubMed

Zur, Moran; Gasparini, Marisa; Wolk, Omri; Amidon, Gordon L; Dahan, Arik

2014-05-05

Although recognized as overly conservative, metoprolol is currently the common low/high BCS permeability class boundary reference compound, while labetalol was suggested as a potential alternative. The purpose of this study was to identify the various characteristics that the optimal marker should exhibit, and to investigate the suitability of labetalol as the permeability class reference drug. Labetalol's BCS solubility class was determined, and its physicochemical properties and intestinal permeability were thoroughly investigated, both in vitro and in vivo in rats, considering the complexity of the whole of the small intestine. Labetalol was found to be unequivocally a high-solubility compound. In the pH range throughout the small intestine (6.5-7.5), labetalol exhibited pH-dependent permeability, with higher permeability at higher pH values. While in vitro octanol-buffer partitioning (Log D) values of labetalol were significantly higher than those of metoprolol, the opposite was evident in the in vitro PAMPA permeability assay. The results of the in vivo perfusion studies in rats lay between the two contradictory in vitro studies; metoprolol was shown to have moderately higher rat intestinal permeability than labetalol. Theoretical distribution of the ionic species of the drugs was in corroboration with the experimental in vitro and the in vivo data. We propose three characteristics that the optimal permeability class reference drug should exhibit: (1) fraction dose absorbed in the range of 90%; (2) the optimal marker drug should be absorbed largely via passive transcellular permeability, with no/negligible carrier-mediated active intestinal transport (influx or efflux); and (3) the optimal marker drug should preferably be nonionizable. The data presented in this paper demonstrate that neither metoprolol nor labetalol can be regarded as optimal low/high-permeability class boundary standard. While metoprolol is too conservative due to its complete absorption, labetalol has been shown to be a substrate for P-gp-mediated efflux transport, and both drugs exhibit significant segmental-dependent permeability along the gastrointestinal tract. Nevertheless, the use of metoprolol as the marker compound does not carry a risk of bioinequivalence: Peff value similar to or higher than metoprolol safely indicates high-permeability classification. On the other hand, a more careful data analysis is needed if labetalol is used as the reference compound.

Pharmacokinetics and bioequivalence of ranitidine and bismuth derived from two compound preparations

PubMed Central

Zhou, Quan; Ruan, Zou-Rong; Yuan, Hong; Jiang, Bo; Xu, Dong-Hang

2006-01-01

AIM: To evaluate the bioequivalence of ranitidine and bismuth derived from two compound preparations. METHODS: The bioavailability was measured in 20 healthy male Chinese volunteers following a single oral dose (equivalent to 200 mg of ranitidine and 220 mg of bismuth) of the test or reference products in the fasting state. Then blood samples were collected for 24 h. Plasma concentrations of ranitidine and bismuth were analyzed by high-performance liquid chromatography and inductively coupled plasma-mass spectrometry (ICP-MS), respectively. The non-compartmental method was used for pharmacokinetic analysis. Log-transformed Cmax, AUC(0-t) and AUC(0-infinity) were tested for bioequivalence using ANOVA and Schuirmann two-one sided t-test. Tmax was analyzed by Wilcoxon’s test. RESULTS: Various pharmacokinetic parameters of ranitidine derived from the two compound preparations, including Cmax, AUC(0-t), AUC(0-infinity), Tmax and T1/2, were nearly consistent with previous observations. These parameters derived from test and reference drug were as follows: Cmax (0.67 ± 0.21 vs 0.68 ± 0.22 mg/L), AUC(0-t) (3.1 ± 0.6 vs 3.0 ± 0.7 mg/L per hour), AUC(0-infinity) (3.3 ± 0.6 vs 3.2 ± 0.8 mg/L per hour), Tmax (2.3 ± 0.9 vs 2.1 ± 0.9 h) and T1/2 (2.8 ± 0.3 vs 3.1 ± 0.4 h). In addition, double-peak absorption profiles of ranitidine were found in some Chinese volunteers. For bismuth, those parameters derived from test and reference drug were as follows: Cmax (11.80 ± 7.36 vs 11.40 ± 6.55 μg/L), AUC(0-t) (46.65 ± 16.97 vs 47.03 ± 21.49 μg/L per hour), Tmax (0.50 ± 0.20 vs 0.50 ± 0.20 h) and T1/2 (10.2 ± 2.3 vs 13.0 ± 6.9 h). Ninety percent of confidence intervals for the test/reference ratio of Cmax, AUC(0-t) and AUC(0-infinity) derived from both ranitidine and bismuth were found within the bioequivalence acceptable range of 80%-125%. No significant difference was found in Tmax derived from both ranitidine and bismuth. CONCLUSION: The two compound preparations are bioequivalent and may be prescribed interchangeably. PMID:16718762

Quality control and identification of steroid saponins from Dioscorea zingiberensis C. H. Wright by fingerprint with HPLC-ELSD and HPLC-ESI-Quadrupole/Time-of-fight tandem mass spectrometry.

PubMed

Zhang, Xinxin; Liang, Jinru; Liu, Jianli; Zhao, Ye; Gao, Juan; Sun, Wenji; Ito, Yoichiro

2014-03-01

In this study, a fingerprint of steroid saponins, the major bioactive constituents in the crude extracts from Dioscorea zingiberensis C. H. Wright (DZW), has been established for the first time by combined use of the following two methods: high-performance liquid chromatography coupled with evaporative light scattering detector (HPLC-ELSD) and the simultaneous characterization of the steroid saponins by high-performance liquid chromatography coupled with electrospray ionization-mass spectrometry and quadrupole tandem time-of-fight mass analyzers detection (HPLC-ESI-Q/TOF). All HPLC analyses were carried out on a Welchrom C18 column (250mm×4.6mm I.D., 5μm) with a mobile phase composed of water and acetonitrile under gradient elution. There were 68 common characteristic peaks in the fingerprints, in which 12 of them were confirmed by comparing their mass spectra and retention times with those of the reference compounds. In order to identify other unknown peaks, their fragmentation behaviors characteristic of the major groups of steroid saponins from DZW with six types of aglycone skeletons were discussed in detail, and possible MS/MS fragmentation pathways were proposed for aiding the structural identification of these components. According to the summarized fragmentation patterns, these peaks were tentatively assigned by matching their empirical molecular formula with those of the published compounds, or by elucidating their quasi-molecular ions and fragment ions referring to available literature information when the reference standards were unavailable. As a result, 22 new steroid saponins were found in DZW for the first time. In addition, the quantitative analysis of the nine (except for the reference compounds A, B, and C) known peaks was accomplished at the same time which indicated that there was a great variability in the amount of these active compounds in different batches in the crude extracts. This approach could demonstrate that the fingerprint could be considered to be a suitable tool to comprehensively improve the quality control of DZW. The identification and structural elucidation of the peaks in the fingerprint may provide important experimental data for further pharmacological and clinical researches. Copyright © 2014. Published by Elsevier B.V.

Thiazolo[3,2-b]-1,2,4-triazole-5(6H)-one substituted with ibuprofen: novel non-steroidal anti-inflammatory agents with favorable gastrointestinal tolerance.

PubMed

Uzgören-Baran, Ayşe; Tel, Banu Cahide; Sarıgöl, Deniz; Oztürk, Elif İnci; Kazkayası, Inci; Okay, Gürol; Ertan, Mevlüt; Tozkoparan, Birsen

2012-11-01

In an effort to establish new candidates with improved analgesic and anti-inflammatory activities and lower ulcerogenic risk, a series of thiazolo[3,2-b]-1,2,4-triazole-5(6H)-one derivatives of ibuprofen were synthesized. All compounds were evaluated for their in vivo anti-inflammatory and analgesic activities in mice. Furthermore, the ulcerogenic risks of the compounds were determined. In general, none of the compounds represent a risk for developing stomach injury as much as observed in the reference drugs ibuprofen and indomethacin. The compounds carrying a 3-phenyl-2-propenylidene (1a), (biphenyl-4-yl)methylidene (1f) and (1-methylpyrrol-2-yl)methylidene (1n) at the 6th position of the fused ring have been evaluated as potential analgesic/anti-inflammatory agents without a gastrointestinal side effect. These new compounds, therefore, deserve further attention to develop new lead drugs. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

1,2-Benzisoselenazol-3(2H)-one Derivatives As a New Class of Bacterial Urease Inhibitors.

PubMed

Macegoniuk, Katarzyna; Grela, Ewa; Palus, Jerzy; Rudzińska-Szostak, Ewa; Grabowiecka, Agnieszka; Biernat, Monika; Berlicki, Łukasz

2016-09-08

Urease inhibitors are considered promising compounds for the treatment of ureolytic bacterial infections, particularly infections resulting from Helicobacter pylori in the gastric tract. Herein, we present the synthesis and the inhibitory activity of novel and highly effective organoselenium compounds as inhibitors of Sporosarcina pasteurii and Helicobacter pylori ureases. These studied compounds represent a class of competitive reversible urease inhibitors. The most active compound, 2-phenyl-1,2-benzisoselenazol-3(2H)-one (ebselen), displayed Ki values equal to 2.11 and 226 nM against S. pasteurii and H. pylori enzymes, respectively, indicating ebselen as one of the most potent low-molecular-weight inhibitors of bacterial ureases reported to date. Most of these molecules penetrated through the cell membrane of the Gram-negative bacteria Escherichia coli (pGEM::ureOP) in vitro. Furthermore, whole-cell studies on the H. pylori J99 reference strain confirmed the high efficiency of the examined organoselenium compounds as urease inhibitors against pathogenic bacteria.

Key volatile compounds in red koji-shochu, a Monascus-fermented product, and their formation steps during fermentation.

PubMed

Rahayu, Yen Yen Sally; Yoshizaki, Yumiko; Yamaguchi, Keiko; Okutsu, Kayu; Futagami, Taiki; Tamaki, Hisanori; Sameshima, Yoshihiro; Takamine, Kazunori

2017-06-01

Red koji, which refers the solid culture grown koji mold on the steamed rice, is one of the ingredients of Asian fermented foods including the Japanese spirit shochu. This study was aimed at elucidating the characteristic flavor and key volatile compounds of red koji-shochu as well as the mechanism of their formation. Sensory evaluation showed that red koji-shochu has the distinctive flavors cheese, sour, milky, and oily. Fifteen key volatile compounds of red koji-shochu were identified by gas chromatography-mass spectrometry and high-performance liquid chromatography, and by comparison between red koji-shochu and white koji-shochu, as another typical shochu. The mash analysis revealed that ketone compounds and short-chain acids derive from red koji. Furthermore, although other key compounds were produced by yeast, it is highly likely that their concentrations were affected directly or indirectly by the high activities of protease and lipase in red koji. Copyright © 2016 Elsevier Ltd. All rights reserved.

Assessment of the usefulness of semipermeable membrane devices for long-term watershed monitoring in an urban slough system

USGS Publications Warehouse

McCarthy, K.

2006-01-01

Semipermeable membrane devices (SPMDs) were deployed at eight sites within the Buffalo Slough, near Portland, Oregon, to (1) measure the spatial and seasonal distribution of dissolved polycyclic aromatic hydrocarbon (PAH) and organochlorine (OC) compounds in the slough, (2) assess the usefulness of SPMDs as a tool for investigating and monitoring hydrophobic compounds throughout the Columbia Slough system, and (3) evaluate the utility of SPMDs as a tool for measuring the long-term effects of watershed improvement activities. Data from the SPMDs revealed clear spatial and seasonal differences in water quality within the slough and indicate that for hydrophobic compounds, this time-integrated passive-sampling technique is a useful tool for long-term watershed monitoring. In addition, the data suggest that a spiking rate of 2-5 ??g/SPMD of permeability/performance reference compounds, including at least one compound that is not susceptible to photodegradation, may be optimum for the conditions encountered here. ?? Springer Science + Business Media, Inc. 2006.

In silico development of new acetylcholinesterase inhibitors.

PubMed

Pascoini, A L; Federico, L B; Arêas, A L F; Verde, B A; Freitas, P G; Camps, I

2018-04-19

In this work, we made use of fragment-based drug design (FBDD) and de novo design to obtain more powerful acetylcholinesterase (AChE) inhibitors. AChE is associated with Alzheimer's disease (AD). It was found that the cholinergic pathways in the cerebral cortex are compromised in AD and the accompanying cholinergic deficiency contributes to the cognitive deterioration of AD patients. In the FBDD approach, fragments are docked into the active site of the protein. As fragments are molecular groups with a low number of atoms, it is possible to study their interaction with localized amino acids. Once the interactions are measured, the fragments are organized by affinity and then linked together to form new molecules with a high degree of interaction with the active site. In the other approach, we used the de novo design technique starting from reference drugs used in the AD treatment. These drugs were broken into fragments (seeds). In the growing strategy, fragments were added to each seed, growing new molecules. In the linking strategy, two or more separated seeds were linked with different fragments. Both strategies combined produced a library of more than 2 million compounds. This library was filtered using absorption, distribution, metabolism, and excretion properties. The resulting library with around six thousand compounds was filtered again. In this case, structures with Tanimoto coefficients >.85 were discarded. The final library with 1500 compounds was submitted to docking studies. As a result, 10 compounds with better interaction energy than the reference drugs were obtained.

New phthalimide-appended Schiff bases: Studies of DNA binding, molecular docking and antioxidant activities.

PubMed

Nayab, Pattan Sirajuddin; Akrema; Ansari, Istikhar A; Shahid, Mohammad; Rahisuddin

2017-08-01

Herein, we investigated new phthalimide-based Schiff base molecules as promising DNA-binding and free radical scavenging agents. Physicochemical properties of these molecules were demonstrated on the basis of elemental analysis, ultraviolet-visible (UV-Vis), infra-red (IR), 1 H and 13 C nuclear magnetic resonance (NMR) spectroscopy. All spectral data are agreed well with the proposed Schiff base framework. The DNA-binding potential of synthesized compounds were investigated by means of UV-visible, fluorescence, iodide quenching, circular dichroism, viscosity and thermal denaturation studies. The intrinsic binding constants (K b ) were calculated from absorption studies were found to be 1.1 × 10 4 and 1.0 × 10 4  M -1 for compounds 2a and 2b suggesting that compound 2a binding abilities with DNA were stronger than the compound 2b. Our studies showed that the presented compounds interact with DNA through groove binding. Molecular docking studies were carried out to predict the binding between Ct-DNA and test compounds. Interestingly, in silico predictions were corroborated with in vitro DNA-binding conclusions. Furthermore, the title compounds displayed remarkable antioxidant activity compared with reference standard. Copyright © 2016 John Wiley & Sons, Ltd.

[Effects of Aptamer-siRNA Nucleic Acid Compound on Growth and Apoptosis in Myeloid Leukemia Cell Line K562].

PubMed

Ping, Juan; Shen, Zhi-Hui; Wang, Bao-Quan; Zhao, Na; Li, Rui; Li, Mian; Pang, Xiao-Bin; Chen, Chuan-Bo

2015-04-01

To explore the effects of aptamer-siRNA nucleic acid compound on growth and apoptosis in myeloid leukemia cell line K562. the changes of cellular morphology and structure were observed by using fluorescence microscope, laser confocal microscope, JEM-4000EX transmission electron microscopy; MTT assay were performed to evaluate the sensibility of K562 cells to aptamer-siRNA compound, the apoptosis was detected by DNA gel electro-phoresis. The remarkably changes of morphology and structure of K562 cells treated with 200 µmol/L aptamer-siRNA were observed under fluorescence microscopy and electromicroscopy. As compared with control, the aptamer-siRNA compound showed more inhibitory effect on K562 cells and there was significant difference (P<0.05). The MTT assay showed that the IC50 value of aptamer-siRNA compound for K562 cells was 150 µmol/L. According to agarose gel electrophoresis observation, when the aptamer-siRNA compound showed effect on K562 cells, the typical DNA lader could be observed. The aptamer-siRNA compound can significantly induce K562 cell apoptosis, and provide reference for gene therapy of patients with chronic myelocytic lenkemia.

The influence of pH on the degradation of phenol and chlorophenols by potassium ferrate.

PubMed

Graham, Nigel; Jiang, Cheng-Chun; Li, Xiang-Zhong; Jiang, Jia-Qian; Ma, Jun

2004-09-01

This paper presents information concerning the influence of solution pH on the aqueous reaction between potassium ferrate and phenol and three chlorinated phenols: 4-chlorophenol (CP), 2,4-dichlorophenol (DCP), 2,4,6-trichlorophenol (TCP). The redox potential and aqueous stability of the ferrate ion, and the reactivity of dissociating compounds, are known to be pH dependent. Laboratory tests have been undertaken over a wide range of pH (5.8-11) and reactant concentrations (ferrate:compound molar ratios of 1:1 to 8:1). The reactivity of trichloroethylene was also investigated as a reference compound owing to its non-dissociating nature. The extent of compound degradation by ferrate was found to be highly pH dependent, and the optimal pH (maximum degradation) decreased in the order: phenol/CP, DCP, TCP; at the optimal pH the degree of degradation of these compounds was similar. The results indicate that for the group of phenol and chlorophenols studied, the presence of an increasing number of chlorine substituent atoms corresponds to an increasing reactivity of the undissociated compound, and a decreasing reactivity of the dissociated compound.

Synthesis and Antidepressant Activity Profile of Some Novel Benzothiazole Derivatives.

PubMed

Demir Özkay, Ümide; Kaya, Ceren; Acar Çevik, Ulviye; Can, Özgür Devrim

2017-09-07

Within the scope of our new antidepressant drug development efforts, in this study, we synthesized eight novel benzothiazole derivatives 3a - 3h . The chemical structures of the synthesized compounds were elucidated by spectroscopic methods. Test compounds were administered orally at a dose of 40 mg/kg to mice 24, 5 and 1 h before performing tail suspension, modified forced swimming, and activity cage tests. The obtained results showed that compounds 3c , 3d , 3f - 3h reduced the immobility time of mice as assessed in the tail suspension test. Moreover, in the modified forced swimming tests, the same compounds significantly decreased the immobility, but increased the swimming frequencies of mice, without any alteration in the climbing frequencies. These results, similar to the results induced by the reference drug fluoxetine (20 mg/kg, po), indicated the antidepressant-like activities of the compounds 3c , 3d , 3f - 3h . Owing to the fact that test compounds did not induce any significant alteration in the total number of spontaneous locomotor activities, the antidepressant-like effects of these derivatives seemed to be specific. In order to predict ADME parameters of the synthesized compounds 3a - 3h , some physicochemical parameters were calculated. The ADME prediction study revealed that all synthesized compounds may possess good pharmacokinetic profiles.

Weighted similarity-based clustering of chemical structures and bioactivity data in early drug discovery.

PubMed

Perualila-Tan, Nolen Joy; Shkedy, Ziv; Talloen, Willem; Göhlmann, Hinrich W H; Moerbeke, Marijke Van; Kasim, Adetayo

2016-08-01

The modern process of discovering candidate molecules in early drug discovery phase includes a wide range of approaches to extract vital information from the intersection of biology and chemistry. A typical strategy in compound selection involves compound clustering based on chemical similarity to obtain representative chemically diverse compounds (not incorporating potency information). In this paper, we propose an integrative clustering approach that makes use of both biological (compound efficacy) and chemical (structural features) data sources for the purpose of discovering a subset of compounds with aligned structural and biological properties. The datasets are integrated at the similarity level by assigning complementary weights to produce a weighted similarity matrix, serving as a generic input in any clustering algorithm. This new analysis work flow is semi-supervised method since, after the determination of clusters, a secondary analysis is performed wherein it finds differentially expressed genes associated to the derived integrated cluster(s) to further explain the compound-induced biological effects inside the cell. In this paper, datasets from two drug development oncology projects are used to illustrate the usefulness of the weighted similarity-based clustering approach to integrate multi-source high-dimensional information to aid drug discovery. Compounds that are structurally and biologically similar to the reference compounds are discovered using this proposed integrative approach.

Optimization of programmed-temperature vaporization injection preparative capillary GC for compound specific radiocarbon analysis.

PubMed

Zhang, Xinyu; Zhao, Liang; Wang, Yexin; Xu, Yunping; Zhou, Liping

2013-07-01

Preparative capillary GC (PCGC) is a powerful tool for the separation and purification of compounds from any complex matrix, which can be used for compound-specific radiocarbon analysis. However, the effect of PCGC parameters on the trapping efficiency is not well understood. Here, we present a comprehensive study on the optimization of parameters based on 11 reference compounds with different physicochemical properties. Under the optimum conditions, the trapping efficiencies of these 11 compounds (including high-boiling-point n-hentriacontane and methyl lignocerate) are about 80% (60-89%). The isolation of target compounds from standard solutions, plant and soil samples demonstrates that our optimized method is applicable for different classes of compounds including n-alkanes, fatty acid esters, long-chain fatty alcohol esters, polycyclic aromatic hydrocarbons (PAHs) and steranes. By injecting 25 μL in large volume injection mode, over 100 μg, high purity (>90%) target compounds are harvested within 24 h. The recovery ranges of two real samples are about 70% (59.9-83.8%) and about 83% (77.2-88.5%), respectively. Compared to previous studies, our study makes significant improvement in the recovery of PCGC, which is important for its wide application in biogeochemistry, environmental sciences, and archaeology. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

IRIS Toxicological Review of Thallium and Compounds ...

EPA Pesticide Factsheets

Thallium compounds are used in the semiconductor industry, the manufacture of optic lenses and low-melting glass, low-temperature thermometers, alloys, electronic devices, mercury lamps, fireworks, and imitation germs, and clinically as an imaging agent in the diagnosis of certain tumors. EPA's assessment of noncancer health effects and carcinogenic potential of thallium compounds was last prepared and added to the IRIS database between 1988 and 1990. The IRIS program is preparing an assessment that will incorporate current health effects information available for thallium and compounds, and current risk assessment methods. The IRIS assessment for thallium compounds will consist of a Toxicological Review and IRIS Summary. The Toxicological Review is a critical review of the physiochemical and toxicokinetic properties of a chemical, and its toxicity in humans and experimental systems. The assessment will present reference values for the noncancer effects of thallium compounds (RfD and Rfc), and a cancer assessment. The Toxicological Review and IRIS Summary have been subject to Agency review, Interagency review, and external scientific peer review. The final product will reflect the Agency opinion on the overall toxicity of thallium and compounds. EPA is undertaking an Integrated Risk Information System (IRIS) health assessment for thallium and compounds. IRIS is an EPA database containing Agency scientific positions on potential adverse human health effec

Development of benzene, toluene, ethylbenzene and xylenes certified gaseous reference materials

NASA Astrophysics Data System (ADS)

Brum, M. C.; Sobrinho, D. C. G.; Fagundes, F. A.; Oudwater, R. J.; Augusto, C. R.

2016-07-01

The work describes the production of certified gaseous reference materials of benzene, toluene, ethylbenzene and xylenes (BTEX) in nitrogen from the gravimetric production up to the long term stability tests followed by the certifying step. The uncertainty in the amount fractions of the compounds in these mixtures was approximately 4% (relative) for the range studied from 2 to 16 µmol/mol. Also the adsorption of the BTEX on the cylinder surface and the tubing were investigated as potential uncertainty source.

Isotopic Constraints on the Sources and Associations of Organic Compounds in Marine Sediments

DTIC Science & Technology

2006-02-01

international standard for 14C dating, Standard Reference Material 4990B " Oxalic Acid". Routine precision for 813 C and Aa4 C measurements are --0.1 and...determined by their depositional settings. Group ’a’ includes organic-rich marine sediments from Guaymas basin (GB), a hydrothermal system with active...is the per mille (%0o) deviation from the international standard for 14C dating, Standard Reference Material 4990B " Oxalic Acid". Precision for V𔃽 C

Novel natural food antimicrobials.

PubMed

Juneja, Vijay K; Dwivedi, Hari P; Yan, Xianghe

2012-01-01

Naturally occurring antimicrobial compounds could be applied as food preservatives to protect food quality and extend the shelf life of foods and beverages. These compounds are naturally produced and isolated from various sources, including plants, animals and microorganisms, in which they constitute part of host defense systems. Many naturally occurring compounds, such as nisin, plant essential oils, and natamycin, have been widely studied and are reported to be effective in their potential role as antimicrobial agents against spoilage and pathogenic microorganisms. Although some of these natural antimicrobials are commercially available and applied in food processing, their efficacy, consumer acceptance and regulation are not well defined. This manuscript reviews natural antimicrobial compounds with reference to their applications in food when applied individually or in combination with other hurdles. It also reviews the mechanism of action of selected natural antimicrobials, factors affecting their antimicrobial activities, and future prospects for use of natural antimicrobials in the food industry.

Mass Spectral Library Quality Assurance by Inter-Library Comparison

NASA Astrophysics Data System (ADS)

Wallace, William E.; Ji, Weihua; Tchekhovskoi, Dmitrii V.; Phinney, Karen W.; Stein, Stephen E.

2017-04-01

A method to discover and correct errors in mass spectral libraries is described. Comparing across a set of highly curated reference libraries compounds that have the same chemical structure quickly identifies entries that are outliers. In cases where three or more entries for the same compound are compared, the outlier as determined by visual inspection was almost always found to contain the error. These errors were either in the spectrum itself or in the chemical descriptors that accompanied it. The method is demonstrated on finding errors in compounds of forensic interest in the NIST/EPA/NIH Mass Spectral Library. The target list of compounds checked was the Scientific Working Group for the Analysis of Seized Drugs (SWGDRUG) mass spectral library. Some examples of errors found are described. A checklist of errors that curators should look for when performing inter-library comparisons is provided.

First principles view on chemical compound space: Gaining rigorous atomistic control of molecular properties

DOE PAGES

von Lilienfeld, O. Anatole

2013-02-26

A well-defined notion of chemical compound space (CCS) is essential for gaining rigorous control of properties through variation of elemental composition and atomic configurations. Here, we give an introduction to an atomistic first principles perspective on CCS. First, CCS is discussed in terms of variational nuclear charges in the context of conceptual density functional and molecular grand-canonical ensemble theory. Thereafter, we revisit the notion of compound pairs, related to each other via “alchemical” interpolations involving fractional nuclear charges in the electronic Hamiltonian. We address Taylor expansions in CCS, property nonlinearity, improved predictions using reference compound pairs, and the ounce-of-gold prizemore » challenge to linearize CCS. Finally, we turn to machine learning of analytical structure property relationships in CCS. Here, these relationships correspond to inferred, rather than derived through variational principle, solutions of the electronic Schrödinger equation.« less

Progress in the field of physiologically active lanosterol compounds

NASA Astrophysics Data System (ADS)

Reshetova, I. G.; Tkhaper, R. K.; Kamernitskii, Alexey V.

1992-08-01

This review correlates the studies (up to 1991) on the isolation, structural determination, biological activity, and synthesis of physiologically active polyoxidised lanosterol derivatives of vegetable (inotodiol, ganoderic acids) and animal (seychellogenin) origin. The cytotoxic, cardiovascular, and other forms of activity of compounds of this type are of considerable interest in relation to their medical use. It is noted that the functionalised side chain (in an open form or containing lactones, lactols, etc.) is generally responsible for the activity exhibited by lanosterol derivatives. Two basic approaches to the derivation of these structures are defined: either by complete reconstruction of the side chain of lanosterol (degradation and rebuilding with oxygen-containing residues) or by progressive functionalisation of the Δ24-side chain of lanosterol. The synthesis of the known anticancer compound "inotodiol", seychellogenins, ganoderic acids, and other compounds are described. The bibliography includes 105 references.

Nuisance Compounds, PAINS Filters, and Dark Chemical Matter in the GSK HTS Collection.

PubMed

Chakravorty, Subhas J; Chan, James; Greenwood, Marie Nicole; Popa-Burke, Ioana; Remlinger, Katja S; Pickett, Stephen D; Green, Darren V S; Fillmore, Martin C; Dean, Tony W; Luengo, Juan I; Macarrón, Ricardo

2018-07-01

High-throughput screening (HTS) hits include compounds with undesirable properties. Many filters have been described to identify such hits. Notably, pan-assay interference compounds (PAINS) has been adopted by the community as the standard term to refer to such filters, and very useful guidelines have been adopted by the American Chemical Society (ACS) and subsequently triggered a healthy scientific debate about the pitfalls of draconian use of filters. Using an inhibitory frequency index, we have analyzed in detail the promiscuity profile of the whole GlaxoSmithKline (GSK) HTS collection comprising more than 2 million unique compounds that have been tested in hundreds of screening assays. We provide a comprehensive analysis of many previously published filters and newly described classes of nuisance structures that may serve as a useful source of empirical information to guide the design or growth of HTS collections and hit triaging strategies.

Microwave-assisted synthesis and tyrosinase inhibitory activity of chalcone derivatives.

PubMed

Liu, Jinbing; Chen, Changhong; Wu, Fengyan; Zhao, Liangzhong

2013-07-01

A series of chalcones and their derivatives were synthesized, and their inhibitory effects on the diphenolase activity of mushroom tyrosinase were evaluated. The results showed that some of the synthesized compounds exhibited significant inhibitory activity, and four compounds exhibited more potent tyrosinase inhibitory activity than the reference standard inhibitor kojic acid (5-hydroxy-2-(hydroxymethyl)-4H-pyran-4-one). Specifically, 1-(-1-(4-methoxyphen- yl)-3-phenylallylidene)thiosemicarbazide (18) exhibited the most potent tyrosinase inhibitory activity with IC₅₀ value of 0.274 μM. The inhibition mechanism analysis of 1-(-1-(2,4-dihydroxyphenyl)-3-phenylallylidene) thiosemicarbazide (16) and 1-(-1-(4-methoxyphenyl)-3-phenylallylidene) thiosemicarbazide (18) demonstrated that the inhibitory effects of the two compounds on the tyrosinase were irreversible. Preliminary structure activity relationships' analysis suggested that further development of such compounds might be of interest. © 2013 John Wiley & Sons A/S.

Design of inhibitors of thymidylate kinase from Variola virus as new selective drugs against smallpox.

PubMed

Guimarães, Ana P; de Souza, Felipe R; Oliveira, Aline A; Gonçalves, Arlan S; de Alencastro, Ricardo B; Ramalho, Teodorico C; França, Tanos C C

2015-02-16

Recently we constructed a homology model of the enzyme thymidylate kinase from Variola virus (VarTMPK) and proposed it as a new target to the drug design against smallpox. In the present work, we used the antivirals cidofovir and acyclovir as reference compounds to choose eleven compounds as leads to the drug design of inhibitors for VarTMPK. Docking and molecular dynamics (MD) studies of the interactions of these compounds inside VarTMPK and human TMPK (HssTMPK) suggest that they compete for the binding region of the substrate and were used to propose the structures of ten new inhibitors for VarTMPK. Further docking and MD simulations of these compounds, inside VarTMPK and HssTMPK, suggest that nine among ten are potential selective inhibitors of VarTMPK. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

Identification of β-Amino alcohol grafted 1,4,5 trisubstituted 1,2,3-triazoles as potent antimalarial agents.

PubMed

Devender, Nalmala; Gunjan, Sarika; Chhabra, Stuti; Singh, Kartikey; Pasam, Venkata Reddy; Shukla, Sanjeev K; Sharma, Abhisheak; Jaiswal, Swati; Singh, Sunil Kumar; Kumar, Yogesh; Lal, Jawahar; Trivedi, Arun Kumar; Tripathi, Renu; Tripathi, Rama Pati

2016-02-15

In a quest to discover new drugs, we have synthesized a series of novel β-amino alcohol grafted 1,2,3-triazoles and screened them for their in vitro antiplasmodial and in vivo antimalarial activity. Among them, compounds 16 and 25 showed potent activity against chloroquine-sensitive (Pf3D7) strain with IC50 of 0.87 and 0.3 μM respectively, while compounds 7 and 13 exhibited better activity in vitro than the reference drug against chloroquine-resistance strain (PfK1) with IC50 of 0.5 μM each. Compound 25 showed 86.8% in vivo antimalarial efficacy with favorable pharmacokinetic parameters. Mechanistic studies divulged that potent compounds significantly boosted p53 protein levels to exhibit the antimalarial activity. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

Phase Transition Enthalpy Measurements of Organic and Organometallic Compounds. Sublimation, Vaporization and Fusion Enthalpies From 1880 to 2015. Part 1. C{sub 1} − C{sub 10}

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

Acree, William; Chickos, James S.

2016-09-15

A compendium of phase change enthalpies published in 2010 is updated to include the period 1880–2015. Phase change enthalpies including fusion, vaporization, and sublimation enthalpies are included for organic, organometallic, and a few inorganic compounds. Part 1 of this compendium includes organic compounds from C{sub 1} to C{sub 10}. Part 2 of this compendium, to be published separately, will include organic and organometallic compounds from C{sub 11} to C{sub 192}. Sufficient data are presently available to permit thermodynamic cycles to be constructed as an independent means of evaluating the reliability of the data. Temperature adjustments of phase change enthalpies frommore » the temperature of measurement to the standard reference temperature, T = 298.15 K, and a protocol for doing so are briefly discussed.« less

Effects of Compounded Stanford Modified Oral Rinse (MucoLox) on the Survival and Migration of Oral Keratinocytes and Fibroblasts: Implications for Wound Healing.

PubMed

Song, Guiyun; Banov, Daniel; Bassani, August S

2018-01-01

Several oral rinses are commercially available to alleviate the symptoms of oral mucositis. Prolonged retention of active pharmaceutical ingredients in the oral cavity is a major problem. In this study, we modified the Stanford oral rinse by including a proprietary mucoadhesive polymer called MucoLox, which we hypothesized would improve active pharmaceutical ingredient mucoadhesion. Characterization of this newly compounded oral rinse showed absence of cytotoxicity in human oral keratinocyte and fibroblast cell lines. The compounded formulation significantly stimulated the migration of these two cell lines in Oris Cell Migration Assay plates, better than the reference commercial product Magic mouthwash. Based on this in vitro study, the new Stanford modified oral rinse with MucoLox is safe and may promote healing of oral mucositis. Copyright© by International Journal of Pharmaceutical Compounding, Inc.

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

PubMed

Senthilraja, Manavalan; Alagarsamy, Veerachamy

2012-10-01

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

Synthesis and α-glucosidase inhibition activity of dihydroxy pyrrolidines.

PubMed

Kasturi, Sivaprasad; Surarapu, Sujatha; Uppalanchi, Srinivas; Anireddy, Jaya Shree; Dwivedi, Shubham; Anantaraju, Hasitha Shilpa; Perumal, Yogeeswari; Sigalapalli, Dilep Kumar; Babu, Bathini Nagendra; Ethiraj, Krishna S

2017-06-15

A new series of Deacetylsarmentamide A and B derivatives, amides and sulfonamides of 3,4-dihydroxypyrrolidines as α-glucosidase inhibitors were designed and synthesized. The biological screening test against α-glucosidase showed that some of these compounds have the positive inhibitory activity against α-glucosidase. Saturated aliphatic amides were more potent than the olefinic amides. Among all the compounds, 5o/6o having polar -NH 2 group, 10f/11f having polar -OH group on phenyl ring displayed 3-4-fold more potent than the standard drugs. Acarbose, Voglibose and Miglitol were used as standard references. The promising compounds 6i, 5o, 6o, 10a, 11a, 10f and 11f have been identified. Molecular docking simulations were done for compounds to identify important binding modes responsible for inhibition activity of α-glucosidase. Copyright © 2017 Elsevier Ltd. All rights reserved.

Mass Spectral Library Quality Assurance by Inter-Library Comparison

PubMed Central

Wallace, W.E.; Ji, W.; Tchekhovskoi, D.V.; Phinney, K.W.; Stein, S.E.

2017-01-01

A method to discover and correct errors in mass spectral libraries is described. Comparing across a set of highly curated reference libraries compounds that have the same chemical structure quickly identifies entries that are outliers. In cases where three or more entries for the same compound are compared the outlier as determined by visual inspection was almost always found to contain the error. These errors were either in the spectrum itself or in the chemical descriptors that accompanied it. The method is demonstrated on finding errors in compounds of forensic interest in the NIST/EPA/NIH Mass Spectral Library. The target list of compounds checked was the Scientific Working Group for the Analysis of Seized Drugs (SWGDRUG) mass spectral library. Some examples of errors found are described. A checklist of errors that curators should look for when performing inter-library comparisons is provided. PMID:28127680

Symmetry breaking in the planar configurations of disilicon tetrahalides: Pseudo-Jahn-Teller effect parameters, hardness and electronegativity.

PubMed

Kouchakzadeh, Ghazaleh; Nori-Shargh, Davood

2015-11-21

CCSD(T), MP2, LC-BLYP, LC-ωPBE and B3LYP methods with the Def2-TZVPP basis set and natural bond orbital (NBO) interpretations were performed to investigate the correlations between the Pseudo-Jahn-Teller Effect (PJTE) parameters [i.e. vibronic coupling constant values (F), energy gaps between reference states (Δ) and the primary force constant (K0)], structural and configurational properties, global hardness, global electronegativity, natural bond orders, stabilization energies associated with electron delocalizations and natural atomic charges of disilicon tetrafluoride (1), disilicon tetrachloride (2), disilicon tetrabromide (3) and disilicon tetraiodide (4). All levels of theory showed the trans-bent (C2h) configurations as the energy minimum structures of compounds 1-4, and the flap angles between the X2Si planes and the Si=Si bonds in the distorted (C2h) configurations decrease from compound 1 to compound 4. The negative curvatures of the ground state electronic configurations and the positive curvatures of the excited states of the adiabatic potential energy surfaces (APESs) which resulted from the mixing of the ground Ag and excited B2g states are due to the PJTE (i.e. PJT(Ag + B2g) ⊗ b2g problem). Contrary to the usual expectation, with the decrease of the energy gaps between reference states (Δ), the PJTE stabilization energy, E(PJT), decreases from compound 1 to compound 4. The canonical molecular orbital (CMO) analysis revealed that the contributions of the ψ(HOMO)(b3u) and ψL(UMO)(b1u) molecular orbitals in the vibronic coupling constant (F) decrease from compound 1 to compound 4. This fact clearly justifies the decrease of the vibronic coupling constant (F) and the primary force constant (the force constant without the PJTE) values on going from compound 1 to compound 4, leading to the decrease of the negative curvatures of the ground state electronic configuration curves of their corresponding APESs. The results obtained showed that the stabilization energies associated with the mixing of the distorted donor π(Si-Si)(b(u)) bonding and acceptor σ(Si-Si)*(b(u)) antibonding orbitals along the b2g bending distortions decrease from compound 1 to compound 4. This fact reasonably explains the increase of the Si-Si natural bond orders (nbo) on going from compound 1 to compound 4. With the increase of the Si-Si natural bond orders, the corresponding E(PJT) decreases from compound 1 to compound 4. Importantly, the variations of the global hardness (η) differences (Δ[η(C2h) - η(D2h)]) do not correlate with the trend observed for their corresponding total energy differences, justifying that the configurational properties of compounds 1-4 do not obey the maximum hardness principle. Interestingly, the trans-bent (C2h) configurations of compounds 1-4 are more electronegative than their corresponding planar (D2h) forms and the variations of their global electronegativity (χ) differences (Δ[χ(C2h) - χ(D2h)]) succeed in accounting for the decrease of the E(PJT) stabilization energies for the D2h → C2h conversion processes on going from compound 1 to compound 4.

Organoelement chemistry: promising growth areas and challenges

NASA Astrophysics Data System (ADS)

Abakumov, G. A.; Piskunov, A. V.; Cherkasov, V. K.; Fedushkin, I. L.; Ananikov, V. P.; Eremin, D. B.; Gordeev, E. G.; Beletskaya, I. P.; Averin, A. D.; Bochkarev, M. N.; Trifonov, A. A.; Dzhemilev, U. M.; D'yakonov, V. A.; Egorov, M. P.; Vereshchagin, A. N.; Syroeshkin, M. A.; Jouikov, V. V.; Muzafarov, A. M.; Anisimov, A. A.; Arzumanyan, A. V.; Kononevich, Yu N.; Temnikov, M. N.; Sinyashin, O. G.; Budnikova, Yu H.; Burilov, A. R.; Karasik, A. A.; Mironov, V. F.; Storozhenko, P. A.; Shcherbakova, G. I.; Trofimov, B. A.; Amosova, S. V.; Gusarova, N. K.; Potapov, V. A.; Shur, V. B.; Burlakov, V. V.; Bogdanov, V. S.; Andreev, M. V.

2018-05-01

The chemistry of organoelement compounds is now one of the most rapidly developing fields of research, regarding both fundamental science and solution of applied problems. This review covers a variety of classes of organoelement compounds, ranging from molecules with highly labile carbon–element bonds to compounds with stable bonds that form the basis of novel structural materials and demonstrates their role in scientific research and industrial production. The use of Grignard reagents in modern organic synthesis and application of catalytic cyclomagnesiation and cycloalumination reactions for the preparation of difficult-to-access metallacycles are considered. The electron transfer processes in redox-active derivatives of Group 14 elements and the role of radical ions in these processes are discussed. Considerable attention is paid to organometallic compounds, first of all, as catalysts; the dynamic nature of catalysis with these compounds is noted. Unusual strained metallacycles of high thermal stability, zirconacyclocumulenes, which also exhibit catalytic activity, are described. Complexes with redox-active ligands that substantially affect the reactivity of the metal centre and directly participate in reactions with various substrates as well as organometallic compounds of lanthanides are considered. Modern environmentally benign methods for the synthesis of organosilicon compounds and production of unique materials based on them are discussed. Particular Sections are devoted to organophosphorus compounds, including those exhibiting therapeutic properties and possessing unusual optical characteristics, and organic chalcogen compounds, which find use as ligands and biologically active molecules. The bibliography includes 1045 references.

Practical Synthesis, Antidepressant, and Anticonvulsant Activity of 3-Phenyliminoindolin-2-one Derivatives.

PubMed

Ma, Jian-Yin; Quan, Ying-Chun; Jin, Hong-Guo; Zhen, Xing-Hua; Zhang, Xue-Wu; Guan, Li-Ping

2016-03-01

Herein, a series of 3-phenyliminoindolin-2-one derivatives were designed, synthesized, and screened for their antidepressant and anticonvulsant activities. The IR spectra of the compounds afforded NH stretching (3340-3346 cm(-1)) bands and C=O stretching (1731-1746 cm(-1)). In the (1)H-NMR spectra of the compounds, N-H protons of indoline ring were observed at 10.65-10.89 ppm generally as broad bands, and (13)C-NMR spectra of the compounds C=O were seen at 161.72-169.27 ppm. Interestingly, compounds 3o, 3p and 3r significantly shortened immobility time in the The forced swimming test (FST) and The tail suspension test (TST) at 50 mg/kg dose levels. In addition, compound 3r exhibited higher levels of efficacy than the reference standard fluoxetine but had no effect on locomotor activity in the open-field test. Compound 3r significantly increased serotonin and norepinephrine and the metabolite 5-hydroxyindoleacetic acid in mouse brain, suggesting that the effects of compound 3r may be mediated through these neurotransmitters. In the seizure screen, 15 compounds showed some degree against PTZ-induced seizure at a dose of 100 mg/kg, and the tested compounds did not show any neurotoxicity at a dose of 300 mg/kg in the rotarod test. © 2015 John Wiley & Sons A/S.

In vitro and in vivo assessment of newer quinoxaline-oxadiazole hybrids as antimicrobial and antiprotozoal agents.

PubMed

Patel, Navin B; Patel, Jignesh N; Purohit, Amit C; Patel, Vatsal M; Rajani, Dhanji P; Moo-Puc, Rosa; Lopez-Cedillo, Julio Cesar; Nogueda-Torres, Benjamin; Rivera, Gildardo

2017-09-01

A new series of N-(substituted-phenyl)-2-[5-(quinoxalin-2-yloxymethyl)-[1,3,4] oxadiazol-2-ylsulfanyl]-acetamides (5a-o) was designed and synthesised from the parent compound 2-hydroxy quinoxaline (1) through a multistep reaction sequence and was characterised by spectral and elemental analyses. All of the compounds synthesised were evaluated for their antimicrobial and antiprotozoal activities. The results revealed that quinoxaline-based 1,3,4-oxadiazoles displayed promising antibacterial, antifungal and anti-Trypanosoma cruzi activities compared with reference drugs, particularly the lead compound 5l in a short-term in vivo model in T. cruzi. Copyright © 2017 Elsevier B.V. and International Society of Chemotherapy. All rights reserved.

3D visualization of molecular structures in the MOGADOC database

NASA Astrophysics Data System (ADS)

Vogt, Natalja; Popov, Evgeny; Rudert, Rainer; Kramer, Rüdiger; Vogt, Jürgen

2010-08-01

The MOGADOC database (Molecular Gas-Phase Documentation) is a powerful tool to retrieve information about compounds which have been studied in the gas-phase by electron diffraction, microwave spectroscopy and molecular radio astronomy. Presently the database contains over 34,500 bibliographic references (from the beginning of each method) for about 10,000 inorganic, organic and organometallic compounds and structural data (bond lengths, bond angles, dihedral angles, etc.) for about 7800 compounds. Most of the implemented molecular structures are given in a three-dimensional (3D) presentation. To create or edit and visualize the 3D images of molecules, new tools (special editor and Java-based 3D applet) were developed. Molecular structures in internal coordinates were converted to those in Cartesian coordinates.

Future climate risk from compound events

NASA Astrophysics Data System (ADS)

Zscheischler, Jakob; Westra, Seth; van den Hurk, Bart J. J. M.; Seneviratne, Sonia I.; Ward, Philip J.; Pitman, Andy; AghaKouchak, Amir; Bresch, David N.; Leonard, Michael; Wahl, Thomas; Zhang, Xuebin

2018-06-01

Floods, wildfires, heatwaves and droughts often result from a combination of interacting physical processes across multiple spatial and temporal scales. The combination of processes (climate drivers and hazards) leading to a significant impact is referred to as a `compound event'. Traditional risk assessment methods typically only consider one driver and/or hazard at a time, potentially leading to underestimation of risk, as the processes that cause extreme events often interact and are spatially and/or temporally dependent. Here we show how a better understanding of compound events may improve projections of potential high-impact events, and can provide a bridge between climate scientists, engineers, social scientists, impact modellers and decision-makers, who need to work closely together to understand these complex events.

Design, synthesis, molecular docking, anti-Proteus mirabilis and urease inhibition of new fluoroquinolone carboxylic acid derivatives.

PubMed

Abdullah, Mohammed A A; Abuo-Rahma, Gamal El-Din A A; Abdelhafez, El-Shimaa M N; Hassan, Heba A; Abd El-Baky, Rehab M

2017-02-01

New hydroxamic acid, hydrazide and amide derivatives of ciprofloxacin in addition to their analogues of levofloxacin were prepared and identified by different spectroscopic techniques. Some of the prepared compounds revealed good activity against the urease splitting bacteria, Proteus mirabilis. The urease inhibitory activity was investigated using indophenol method. Most of the tested compounds showed better activity than the reference acetohydroxamic acid (AHA). The ciprofloxacin hydrazide derivative 3a and levofloxacin hydroxamic acid 7 experienced the highest activity (IC 50 =1.22μM and 2.20μM, respectively). Molecular docking study revealed high spontaneous binding ability of the tested compounds to the active site of urease. Copyright © 2016 Elsevier Inc. All rights reserved.

Transformations of organic compounds under the action of mechanical stress

NASA Astrophysics Data System (ADS)

Dubinskaya, Aleksandra M.

1999-08-01

Transformations of organic compounds (monomeric and polymeric) under the action of mechanical stress are considered. Two types of processes occur under these conditions. The first type involves disordering and amorphisation of crystal structure and conformational transformations as a result of rupture of intermolecular bonds. The second type includes mechanochemical reactions activated by deformation of valence bonds and angles under mechanical stress, namely, the rupture of bonds, oxidation and hydrolysis. Data on the organic mechanochemical synthesis of new compounds or molecular complexes are systematised and generalised. It is demonstrated that mechanical treatment ensures mass transfer and the contact of reacting species in these reactions. Proteins are especially sensitive to mechanical stress and undergo denaturation; enzymes are inactivated. The bibliography includes 115 references.

Three new fatty acids from the roots of Boehmeria nivea (L.) Gaudich and their antifungal activities.

PubMed

Xu, Qiong-Ming; Liu, Yan-Li; Li, Xiao-Ran; Li, Xia; Yang, Shi-Lin

2011-03-01

Three new unsaturated fatty acids, (Z)-9,10,11-trihydroxy-12-octadecenoic acid (1), (Z)-7,8,9-trihydroxy-10-hexadecenoic acid (2) and (Z)-12-keto-7,8,9-trihydroxy-10-hexadecenoic acid (3) were isolated from the roots of Boehmeria nivea (L.) Gaudich, along with a known unsaturated fatty acid, (E)-8,11,12-trihydroxy-9-octadecenoic acid (4). The structures of the new compounds were established by HR ESI-MS, (1)H, (13)C, 2D ((1)H-(1)H COSY, HSQC, HMBC) NMR experiments. The known compound was identified by a comparison of its spectral data with published references. The three new compounds showed some antifungal activities by agar assay.

Androgen Receptor Antagonists and Anti-Prostate Cancer Activities of Some Newly Synthesized Substituted Fused Pyrazolo-, Triazolo- and Thiazolo-Pyrimidine Derivatives

PubMed Central

Bahashwan, Saleh A.; Fayed, Ahmed A.; Ramadan, Mohamed A.; Amr, Abd El-Galil E.; Al-Harbi, Naif O.

2014-01-01

A series of substituted pyrazole, triazole and thiazole derivatives (2–13) were synthesized from 1-(naphtho[1,2-d]thiazol-2-yl)hydrazine as starting material and evaluated as androgen receptor antagonists and anti-prostate cancer agents. The newly synthesized compounds showed potent androgen receptor antagonists and anti-prostate cancer activities with low toxicity (lethal dose 50 (LD50)) comparable to Bicalutamide as reference drug. The structures of newly synthesized compounds were confirmed by IR, 1H-NMR, 13C-NMR, and MS spectral data and elemental analysis. The detailed synthesis, spectroscopic data, LD50 values and pharmacological activities of the synthesized compounds are reported. PMID:25421248

Analysis of pharmaceutical and other organic wastewater compounds in filtered and unfiltered water samples by gas chromatography/mass spectrometry

USGS Publications Warehouse

Zaugg, Steven D.; Phillips, Patrick J.; Smith, Steven G.

2014-01-01

Research on the effects of exposure of stream biota to complex mixtures of pharmaceuticals and other organic compounds associated with wastewater requires the development of additional analytical capabilities for these compounds in water samples. Two gas chromatography/mass spectrometry (GC/MS) analytical methods used at the U.S. Geological Survey National Water Quality Laboratory (NWQL) to analyze organic compounds associated with wastewater were adapted to include additional pharmaceutical and other organic compounds beginning in 2009. This report includes a description of method performance for 42 additional compounds for the filtered-water method (hereafter referred to as the filtered method) and 46 additional compounds for the unfiltered-water method (hereafter referred to as the unfiltered method). The method performance for the filtered method described in this report has been published for seven of these compounds; however, the addition of several other compounds to the filtered method and the addition of the compounds to the unfiltered method resulted in the need to document method performance for both of the modified methods. Most of these added compounds are pharmaceuticals or pharmaceutical degradates, although two nonpharmaceutical compounds are included in each method. The main pharmaceutical compound classes added to the two modified methods include muscle relaxants, opiates, analgesics, and sedatives. These types of compounds were added to the original filtered and unfiltered methods largely in response to the tentative identification of a wide range of pharmaceutical and other organic compounds in samples collected from wastewater-treatment plants. Filtered water samples are extracted by vacuum through disposable solid-phase cartridges that contain modified polystyrene-divinylbenzene resin. Unfiltered samples are extracted by using continuous liquid-liquid extraction with dichloromethane. The compounds of interest for filtered and unfiltered sample types were determined by use of the capillary-column gas chromatography/mass spectrometry. The performance of each method was assessed by using data on recoveries of compounds in fortified surface-water, wastewater, and reagent-water samples. These experiments (referred to as spike experiments) consist of fortifying (or spiking) samples with known amounts of target analytes. Surface-water-spike experiments were performed by using samples obtained from a stream in Colorado (unfiltered method) and a stream in New York (filtered method). Wastewater spike experiments for both the filtered and unfiltered methods were performed by using a treated wastewater obtained from a single wastewater treatment plant in New York. Surface water and wastewater spike experiments were fortified at both low and high concentrations and termed low- and high-level spikes, respectively. Reagent water spikes were assessed in three ways: (1) set spikes, (2) a low-concentration fortification experiment, and (3) a high-concentration fortification experiment. Set spike samples have been determined since 2009, and consist of analysis of fortified reagent water for target compounds included for each group of 10 to18 environmental samples analyzed at the NWQL. The low-concentration and high-concentration reagent spike experiments, by contrast, represent a one-time assessment of method performance. For each spike experiment, mean recoveries ranging from 60 to 130 percent indicate low bias, and relative standard deviations (RSDs) less than ( Of the compounds included in the filtered method, 21 had mean recoveries ranging from 63 to 129 percent for the low-level and high-level surface-water spikes, and had low ()132 percent]. For wastewater spikes, 24 of the compounds included in the filtered method had recoveries ranging from 61 to 130 percent for the low-level and high-level spikes. RSDs were 130 percent) or variable recoveries (RSDs >30 percent) for low-level wastewater spikes, or low recoveries ( Of the compounds included in the unfiltered method, 17 had mean spike recoveries ranging from 74 to 129 percent and RSDs ranging from 5 to 25 percent for low-level and high-level surface water spikes. The remaining compounds had poor mean recoveries (130 percent), or high RSDs (>29 percent) for these spikes. For wastewater, 14 of the compounds included in the unfiltered method had mean recoveries ranging from 62 to 127 percent and RSDs 130 percent), or low mean recoveries (33 percent) for the low-level wastewater spikes. Of the compounds found in wastewater, 24 had mean set spike recoveries ranging from 64 to 104 percent and RSDs Separate method detection limits (MDLs) were computed for surface water and wastewater for both the filtered and unfiltered methods. Filtered method MDLs ranged from 0.007 to 0.14 microgram per liter (μg/L) for the surface water matrix and from 0.004 to 0.62 μg/L for the wastewater matrix. Unfiltered method MDLs ranged from 0.014 to 0.33 μg/L for the surface water matrix and from 0.008 to 0.36 μg/L for the wastewater matrix.

Design of compound libraries for fragment screening

NASA Astrophysics Data System (ADS)

Blomberg, Niklas; Cosgrove, David A.; Kenny, Peter W.; Kolmodin, Karin

2009-08-01

Approaches to the design of libraries for fragment screening are illustrated with reference to a 20 k generic fragment screening library and a 1.2 k generic NMR screening library. Tools and methods for library design that have been developed within AstraZeneca are described, including Foyfi fingerprints and the Flush program for neighborhood characterization. It will be shown how Flush and the BigPicker, which selects maximally diverse sets of compounds, are used to apply the Core and Layer method for library design. Approaches to partitioning libraries into cocktails are also described.

New reactions involving the oxidative O-, N-, and C-phosphorylation of organic compounds by phosphorus and phosphides in the presence of metal complexes

NASA Astrophysics Data System (ADS)

Dorfman, Ya A.; Aleshkova, M. M.; Polimbetova, G. S.; Levina, L. V.; Petrova, T. V.; Abdreimova, R. R.; Doroshkevich, D. M.

1993-09-01

The mechanisms of new catalytic reactions leading to the formation of di-, and tri-alkyl phosphates, di- and tri-alkyl phosphites, phosphoramidites, phosphazenes, phosphines, and phosphine oxides from hydrogen, copper, and zinc phosphides and white and red phosphorus are analysed. The mechanisms of the activation of the reactants by metal complexes and of the reactions involving the oxidative P-O, P-N, and P-C coupling of organic compounds to phosphorus and phosphides are considered. The bibliography includes 124 references.

Biological effect of fluoride on plants

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

Collet, G.F.

1969-10-01

The action of several fluorine compounds was studied by means of hydroponics. Seedlings of several species were used. In leaves of Prunus armeniaca, a good correlation between the extent of necrosis and the leaf's total fluorine content was noted. Boron plays a spectacular role as it enhances the expected fluorine accumulation. Similar results were obtained with other plant material, an observation which suggests that this phenomenon is universal in plant life. Fluorine accumulation and leaf damage due to fluorine depend upon the chemical nature of the fluorine compound. 11 references, 3 figures, 2 tables.

Purine derivatives with antituberculosis activity

NASA Astrophysics Data System (ADS)

Gruzdev, D. A.; Musiyak, V. V.; Levit, G. L.; Krasnov, V. P.; Charushin, V. N.

2018-06-01

The review summarizes the data published over the last 10–15 years concerning the key groups of purine derivatives with antituberculosis activity. The structures of purines containing heteroatoms (S, O, N), fragments of heterocycles, amino acids and peptides, in the 6-position, as well as of purine nucleosides are presented. The possible targets for the action of such compounds and structure–activity relationship are discussed. Particular attention is paid to the most active compounds, which are of considerable interest as a basis for the development of efficient antituberculosis drugs. The bibliography includes 99 references.

Topoisomerase I and II inhibitors: chemical structure, mechanisms of action and role in cancer chemotherapy

NASA Astrophysics Data System (ADS)

Dezhenkova, L. G.; Tsvetkov, V. B.; Shtil, A. A.

2014-01-01

The review summarizes and analyzes recent published data on topoisomerase I and II inhibitors as potential antitumour agents. Functions and the mechanism of action of topoisomerases are considered. The molecular mechanism of interactions between low-molecular-weight compounds and these proteins is discussed. Topoisomerase inhibitors belonging to different classes of chemical compounds are systematically covered. Assays for the inhibition of topoisomerases and the possibilities of using the computer-aided modelling for the rational design of novel drugs for cancer chemotherapy are presented. The bibliography includes 127 references.

Biological evaluation of some new N-(2,6-dimethoxypyrimidinyl) thioureido benzenesulfonamide derivatives as potential antimicrobial and anticancer agents.

PubMed

Ghorab, Mostafa M; Alsaid, Mansour S; El-Gaby, Mohamed S A; Safwat, Nesreen A; Elaasser, Mahmoud M; Soliman, Aiten M

2016-11-29

A series of novel heterocyclic thioureas 3a-u containing sulfonamide moiety have been synthesized by the condensation of isothiocyanatobenzenesulfonamide 2 with a variety of heterocyclic amines. The newly synthesized heterocyclic thioureas were investigated for their antimicrobial and anticancer activity. The in vitro antibacterial and antifungal activity were done using well diffusion method. Interestingly, compounds 3j and 3m, showed similar or better activity compared with the reference drug against the tested microorganisms. Although, 3j was less active among its analogues to inhibit the breast carcinoma cells, it exhibit strong broad spectrum antimicrobial activities. However, The results of the cytotoxic activity revealed that compound 3p was the most active against the breast carcinoma cell line (MCF-7) giving promising IC 50 value of 1.72 μg/mL, compared with reference drug (5-flourouracil) with IC 50 value of 4.8 μg/mL. The most potent compounds in cytotoxic activity 3b and 3p were further docked inside the active site of CAIX and were found to exhibit a proper binding with the active site amino acids according to their bond lengths, angles and conformational energy. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

The Microphysiology Systems Database for Analyzing and Modeling Compound Interactions with Human and Animal Organ Models

PubMed Central

Vernetti, Lawrence; Bergenthal, Luke; Shun, Tong Ying; Taylor, D. Lansing

2016-01-01

Abstract Microfluidic human organ models, microphysiology systems (MPS), are currently being developed as predictive models of drug safety and efficacy in humans. To design and validate MPS as predictive of human safety liabilities requires safety data for a reference set of compounds, combined with in vitro data from the human organ models. To address this need, we have developed an internet database, the MPS database (MPS-Db), as a powerful platform for experimental design, data management, and analysis, and to combine experimental data with reference data, to enable computational modeling. The present study demonstrates the capability of the MPS-Db in early safety testing using a human liver MPS to relate the effects of tolcapone and entacapone in the in vitro model to human in vivo effects. These two compounds were chosen to be evaluated as a representative pair of marketed drugs because they are structurally similar, have the same target, and were found safe or had an acceptable risk in preclinical and clinical trials, yet tolcapone induced unacceptable levels of hepatotoxicity while entacapone was found to be safe. Results demonstrate the utility of the MPS-Db as an essential resource for relating in vitro organ model data to the multiple biochemical, preclinical, and clinical data sources on in vivo drug effects. PMID:28781990

Analysis of mexicanolide- and phragmalin-type limonoids from Heynea trijuga using high-performance liquid chromatography/electrospray tandem mass spectrometry.

PubMed

Yang, Wei; Fang, Dong-Mei; He, Hong-Ping; Hao, Xiao-Jiang; Wu, Zhi-Jun; Zhang, Guo-Lin

2013-06-15

Limonoids, a class of tetranortriterpenoids, exhibit various biological effects, including acting as potent antifeedants and insect growth-regulators against various pests. The analysis of phragmalin- and mexicanolide-type limonoids by collision-induced dissociation tandem mass spectrometry (CID-MS/MS) has not been reported. A high-performance liquid chromatography/electrospray ionization (HPLC/ESI)-MS/MS method was developed to investigate the fragmentation patterns of [M+NH4 ](+) ions for nine reference phragmalin- and mexicanolide-type limonoids. The method was also used in the identification of limonoid compounds in botanic extracts of Heynea trijuga. The losses of side chains and the furan part were the major fragmentation patterns. However, there was variation in the relative abundances of product ions resulting from the same fragmentation pathways. A total of 89 phragmalin- and mexicanolide-type limonoids in botanic extracts of Heynea trijuga were detected and 50 of these compounds were identified or tentatively characterized based on elemental constituents, fragmentation pathways, and the profile of the major product ions of reference compounds. In addition, the isomers could be tentatively distinguished. An HPLC/ESI-MS/MS method was developed and could be used to simultaneously identify and screen phragmalin- and mexicanolide-type limonoids in botanic extracts of Heynea trijuga. Copyright © 2013 John Wiley & Sons, Ltd.

[Toxicological and analytical lists: chromium and its compounds].

PubMed

Minoia, C; Apostoli, P; Battaglia, A; Catenacci, G; Cottica, D; Franco, G; Pozzoli, L; Vanola, C; Candura, F; Capodaglio, E

1987-03-01

The main aspects of occupational exposure to chromium and chromium compounds are surveyed. Special attention is paid to the toxic action of this metal at the different target organs. The nutritional aspect of CrIII is examined preliminarily, and data detailing the metal contents in water and food are provided. As far the different working processes that entail occupational exposure to chromium are concerned, hygienic and environmental problems are discussed while identifying the average environment exposure to the different chemical forms of chromium (CrIII, CrIV, soluble and not soluble), as a function of the worker's tasks, and the relevant human response (total human Cr). Different hygienic and environmental standards in force in various countries and applicable to chromium compounds are compared. Additional information is given on the main aspects of chromium metabolism (absorption, distribution, excretion), and on the prevailing toxic actions, with specific reference to cancerogenesis. As far as biologic monitoring of the exposed people is concerned, the significance of Cr-U as dose-exposure indicator is discussed, also in the light of a critical review of the reference values. The report describes a series of analytical methods for the identification of chromium in aqueous and biologic matrices. The problems connected with health monitoring and fitness for work are eventually covered.

Implications of domestic food practices for the presence of bioactive components in meats with special reference to meat-based functional foods.

PubMed

Jiménez-Colmenero, Francisco; Cofrades, Susana; Herrero, Ana M; Ruiz-Capillas, Claudia

2017-06-14

Although an essential component of the diet, the consumption of meat is in question. Meat is a major source of beneficial compounds but it also contains other substances with negative health implications. Functional foods, which are leading trends in the food industry, constitute an excellent opportunity for the meat sector to improve healthier meat options. Most studies on meat-based functional foods have focused mainly on the application of different strategies (animal production practices and meat transformation systems) to improve (increase/reduce) the presence of bioactive (healthy/unhealthy) compounds; these have led to the development of numerous products, many of them by the meat industry. However, like other foods, after purchase meats undergo certain processes before they are consumed, and these affect their composition. Although domestic handling practices can significantly alter the make-up of the marketed product in terms of healthy/unhealthy compounds, there are very few studies on their consequences. This paper provides an overview of the influence of different domestic practices (from shopping to eating) habitually followed by consumers on the presence of, and consequently on the levels of exposure to, (healthy and unhealthy) food components associated with the consumption of meats, with special reference to meat-based functional foods.

SICK BUILDING SYNDROME: POSSIBLE ASSOCIATIONS WITH EXPOSURE TO MYCOTOXINS FROM INDOOR AIR FUNGI.

EPA Science Inventory

Introduction. Chronic human illness associated with residential or occupational buildings, commonly referred to as sick building syndrome (SBS), may be a multifactorial condition, involving in some cases volatile organic compounds, CO or CO2, pesticides, biologic agents, temperat...

Molecular genetics of secondary chemistry in Metarhizium fungi

USDA-ARS?s Scientific Manuscript database

As with many microbes, entomopathogenic fungi from the genus Metarhizium produce a plethora of small molecule metabolites, often referred to as secondary metabolites. Although these intriguing compounds are a conspicuous feature of the biology of the producing fungi, their roles in pathogenicity and...

Catalytic Amination of Alcohols, Aldehydes, and Ketones

NASA Astrophysics Data System (ADS)

Klyuev, M. V.; Khidekel', M. L.

1980-01-01

Data on the catalytic amination of alcohols and carbonyl compounds are examined, the catalysts for these processes are described, and the problems of their effectiveness, selectivity, and stability are discussed. The possible mechanisms of the reactions indicated are presented. The bibliography includes 266 references.

HIGH-THROUGHPUT CHEMICAL SCREENING USING PROTEIN PROFILING OF FISH PLASMA

EPA Science Inventory

Compounds that affect the hormone system, referred to as "endocrine-disrupting chemicals" (EDCs), cause human and animal health problems. It is necessary to test putative EDC chemicals for such deleterious effects, though current testing methodologies are time/animal intensive an...

NASAL EFFECTS OF A MIXTURE OF VOLATILE ORGANIC COMPOUNDS AND THEIR OZONE OXIDATION PRODUCTS.

EPA Science Inventory

"Nonspecific-building related illness (NSBRI)," or "sick building syndrome," refers to symptomatic complaints associated with occupancy of non-industrial buildings. The diverse symptoms of NSBRI include mucous membrane (eye, nose, throat) irritation, headaches, fatigue, nausea, s...

A History of Catechin Chemistry with Special Reference to Tea Leaves

NASA Astrophysics Data System (ADS)

Ryoyasu, Saijo; Katoh, Miyuki

This review describes the history of the discovery of catechins, i.e., flavan 3-ols in the flavonoid compounds, with a special reference to tea leaves. 1. Catechin was first separated from gambier catechu and acacia catechu, and its molecular weight and chemical structure were proposed in 1902. By 1948 the six catechins,(+)-catechin,(-)-epicatechin,(-)-epicatechin 3-O-gallate,(-)-epigallocatechin,(+)-gallocatechin, and(-)-epigallocatechin 3-O-gallate, as shown in Table 1, had been found in a variety of plants, including tea. Table 1 summarizes each catechin, the plant associated with it, and the year and authorship of each first reporting.(-)-Epigallocatechin 3-gallate was isolated from tea leaves in 1948 as the last compound of the six catechins, even though it accounted for the largest proportion of total catechin content. The compound was not isolated and purified by traditional separation methods, such as the ethyl acetate extraction and lead acetate precipitation methods; instead, silica gel column chromatography was the key technique used to succeed in the separation and purification of the compound, from which the determination of the chemical structure followed. 2. The six catechins in fresh tea leaves are easily epimerized by heat treatment to form the corresponding epimerized catechins, as shown in Table 2. Observation indicates that the six natural and six epimerized catechins can be present in heat-treated dried tea leaves or green teas. 3. The chemical structures of the ten catechins, which include the compounds in Table 1, are shown in Table 3. As the contents of the catechins in fresh tea leaves have been reported many times in the literature, it is certain that these compounds are naturally present in tea leaves. 4. Table 4 summarizes the chemical structures of eight minor catechin derivatives found in tea leaves and oolong teas, the first reporting authors, and the year reported. Because the presence of these catechin derivatives in fresh tea leaves has not been strictly determined, it has not yet been made clear whether the compounds are naturally occurring ones. It is possible that some of these compounds might be artifacts. 5. Table 5 summarizes the chemical structures of eight afzelechin derivatives, the first reporting authors, and the year reported. 6. Table 6 summarizes the chemical structures of ten(+)-catechin derivatives, the first reporting authors, and the year reported.

Preparation of a sewage sludge laboratory quality control material for butyltin compounds and their determination by isotope-dilution mass spectrometry.

PubMed

Zuliani, Tea; Milačič, Radmila; Ščančar, Janez

2012-05-01

The characterisation of a laboratory quality control material (QCM) for dibutyltin (DBT) and tributyltin (TBT) in sewage sludge is described. The reference values were determined by the use of two different types of isotope-dilution mass spectrometry: gas chromatography-mass spectrometry and gas chromatography-inductively coupled plasma mass spectrometry. To avoid possible analytical errors such as non-quantitative extraction and species degradation during sample preparation, different extraction methods were tested (microwave- and ultrasound-assisted extraction and mechanical stirring). The reference values were based on the unweighted means of results from the homogenisation and characterisation studies. The reference values obtained were 1,553 ± 87 and 534 ± 38 ng Sn g(-1) for DBT and TBT, respectively. In the uncertainty budget estimation, the sample inhomogeneity and between-method imprecision were taken into account. The concentrations of DBT and TBT in QCM are similar to those in the harbour sediment certified reference material PACS-2. Likewise, the levels of DBT and TBT are in the range of these compounds normally present in sewage sludge worldwide. In the future, the QCM will be used for an intercomparison study on DBT and TBT in sewage sludge, and as a day-to-day QCM during studies concerning the application of sewage sludge as an additive to artificial soil or as a raw material in civil engineering construction.

Effect of buffer and antioxidant on stability of a mercaptopurine suspension.

PubMed

Aliabadi, Hamidreza Montazeri; Romanick, Marcel; Desai, Sunil; Lavasanifar, Afsaneh

2008-03-01

The stability of standard and modified mercaptopurine suspensions when stored at room temperature and under refrigerated conditions to test the feasibility of increasing shelf life was studied. A 50-mg/mL mercaptopurine suspension was compounded by adding simple syrup, cherry syrup, and sterile water for irrigation to triturated mercaptopurine tablets for the initial reference formulation. Three additional formulations were prepared by adding an antioxidant (ascorbic acid 10 mg), a buffer (sodium phosphate monobasic monohydrate 500 mg), and a combination of antioxidant and buffer to the reference formulation. Each compounded batch was divided into two parts and stored in amber bottles at room temperature (19-23 degrees C) or under refrigerated conditions (4-8 degrees C). Analysis through high-performance liquid chromatography determined mercaptopurine levels after three and seven days and weekly thereafter for at least two weeks after shelf life was reached under specified storage conditions. Solutions with at least 93% of the original mercaptopurine concentration and with no observable sign of aggregation or cake formation were considered stable. The reference suspension of mercaptopurine showed an acceptable physical and chemical stability of up to 5 weeks when stored at room temperature. The addition of ascorbic acid extended the shelf life of the compounded suspension to 11 weeks. However, the addition of sodium phosphate monobasic did not improve the stability of mercaptopurine in the suspension. The results showed a higher stability for all formulations after storage at room temperature compared with those stored in a refrigerator. A standard oral suspension of mercaptopurine contained an acceptable drug concentration for up to 5 weeks when stored at room temperature. The addition of ascorbic acid at a concentration of 0.1% w/v to the standard formulation increased the suspension's shelf life at room temperature to 11 weeks.

Doxycycline concentration over time after storage in a compounded veterinary preparation.

PubMed

Papich, Mark G; Davidson, Gigi S; Fortier, Lisa A

2013-06-15

To determine the concentration of doxycycline compounded from doxycycline hyclate tablets into liquid formulations for oral administration in veterinary species and stored for 28 days. Evaluation study. Doxycycline hyclate tablets (100 mg) crushed and mixed with a 50:50 mixture of syrup and suspension vehicles for oral administration to produce 3 batches each of 2 doxycycline formulations: 33.3 and 166.7 mg/mL. Formulations were stored, protected from light, at room temperature (22° to 26°C [71.6° to 78.8°F]) and at a controlled cold temperature (refrigerated 2° to 8°C [35.6° to 46.4°F]). Doxycycline was extracted from the formulations, and concentration was measured by high-pressure liquid chromatography on days 0 (date of preparation), 1, 4, 7, 14, 21, and 28. Concentrations were compared with those of a US Pharmacopeial Convention reference standard. Formulation quality at each point was also assessed through color change, formulation consistency, and suspension uniformity. On days 0, 1, 4, and 7, the concentration of each formulation was within 90% to 110% of the reference standard (range, 93% to 109%), which was deemed acceptable. However, doxycycline concentrations had decreased dramatically by day 14 and remained low for the duration of the study period. Doxycycline concentrations on days 14, 21, and 28 were all < 20% (range, 14% to 18%) of the reference standard, and the quality of the formulations decreased as well. No effect of storage temperatures on doxycycline concentration was identified. The concentration of doxycycline, compounded from commercial tablets in the vehicles evaluated to yield doses of 33.3 and 166.7 mg/mL, cannot be assured beyond 7 days.

Energy gap formation mechanism through the interference phenomena of electrons in face-centered cubic elements and compounds with the emphasis on half-Heusler and Heusler compounds

NASA Astrophysics Data System (ADS)

Mizutani, U.; Sato, H.

2018-05-01

Many face-centred cubic elements and compounds with the number of atoms per unit cell N equal to 8, 12 and 16 are known to be stabilised by forming either a band gap or a pseudogap at the Fermi level. They are conveniently expressed as cF8, cF12 and cF16, respectively, in the Pearson symbol. From the cF8 family, we worked on three tetravalent elements C (diamond), Si and Ge, SZn-type AsGa compound and NaCl-type compounds like BiLu, AsSc, etc. From the cF12 family, more than 80 compounds were selected, with a particular emphasis on ABC- and half-Heusler-type ternary equiatomic compounds. Among cF16 compounds, both the Heusler compounds ABC2 and Zintl compounds were studied. We revealed that, regardless of whether or not the transition metal (TM) and/or rare-earth (RE) elements are involved as constituent elements, the energy gap formation mechanism for cF8, cF12 and cF16 compounds can be universally discussed in terms of interference phenomenon of itinerant electrons with set of reciprocal lattice planes with ? = 8, 11 and 12, where ? refers to square of the critical reciprocal of lattice vector of an fcc lattice. The number of itinerant electrons per unit cell, e/uc, for all these band gap/pseudogap-bearing compounds is found to fall on a universal line called "3/2-power law" when plotted against ? on a logarithmic scale. This proves the validity of the fulfilment of the interference condition ? in conformity with other pseudogap compounds with different crystal symmetries and different sizes of the unit cell reported in literature.

[Dynamic variation of components in exocarp of Juglans mandshurica with browning based on UPLC-Q-TOF/MS].

PubMed

Sun, Guo-Dong; Huo, Jin-Hai; Xie, Rong-Juan; Wang, Wei-Ming

2017-08-01

To analyze the dynamic changes in components in exocarp of Juglans mandshurica at different browning periods. Twenty-six batches of exocarp of J. mandshurica samples from thirteen browning periods were assessed by UPLC-Q-TOF-MS/MS. The formula of different compounds were determined by accurate mass and isotopic abundance ratio from target screening function of Peakview 2.0/masterview1.0 software. Then their structures were determined by analysis of MS/MS fragment or comparison with standard substances and references. The contents of chemical components were changed significantly in different browning periods and twenty five compounds were identified or inferred. Of the 13 naphthoquinone compounds, the contents of 6 compounds with similar parent nucleus as juglone and 3 naphthoquinone glycosides compounds were decreased significantly, and 4 naphthoquinone derivatives such as regiolone were produced; the contents of four flavones and two phenolic acids compounds were decreased significantly; and the contents of 6 diarylheptanoids compounds were increased significantly. UPLC-Q-TOF/MS method can be used to identify and analyze the chemical constituents from exocarp of J. mandshurica rapidly and accurately, and analyze the rules of dynamic changes, to reveal the browning of Chinese medicinal materials and its effects on compositions of fruits and vegetables. Copyright© by the Chinese Pharmaceutical Association.

Synthesis, Anti-inflammatory and Antibacterial Activities of Novel Pyrazolo[4,3-g]pteridines.

PubMed

Abdel-Mohsen, Shawkat Ahmed; El-Emary, Talaat Ibrahim; El-Kashef, Hussein Salama

2016-01-01

A novel series of 6-substituted pyrazolo[3,4-g]pteridines 2-9 and pyrazolo[4,3-e][1,2,4]triazolo[1,5-c]pteridin-2(3H)-one (thione) 10 and 11 was synthesized using the starting compound 3,7-dimethyl-1-phenylpyrazolo[4',3':5,6]pyrazino[2,3-d][1,3]oxazin-5(1H)-one 2. The structure of the newly synthesized compounds was elucidated by IR, (1)H-NMR, (13)C-NMR, mass spectroscopy and elemental analyses. The anti-inflammatory activity of all the newly synthesized compounds was evaluated using the carrageenan-induced paw oedema test in rats using indomethacin as the reference drug. Compound 11 and the two derivatives 7f and 8b were the most active compounds, showing an activity comparable to indomethacin. Also, the synthesized compounds were evaluated for their antibacterial activity against Gram-positive bacteria (Staphylococcus aureus and Bacillus cereus) and Gram-negative bacteria (Escherichia coli and Pseudomonas aeruginosa) using chloramphenicol as control. The pyrazolotriazolopteridin-2-thione 11, 6-hydroxyethyl- 6a, 6-(4-nitrophenyl)-7g, and 6-(phenylamino) 8b derivatives were found to be the most active compounds against the Gram-positive species. None of them showed any activity against Gram-negative species.

Targeting RORs nuclear receptors by novel synthetic steroidal inverse agonists for autoimmune disorders.

PubMed

Dal Prà, Matteo; Carta, Davide; Szabadkai, Gyorgy; Suman, Matteo; Frión-Herrera, Yahima; Paccagnella, Nicola; Castellani, Giulia; De Martin, Sara; Ferlin, Maria Grazia

2018-05-01

Designing novel inverse agonists of NR RORγt still represents a challenge for the pharmaceutical community to develop therapeutics for treating immune diseases. By exploring the structure of NRs natural ligands, the representative arotenoid ligands and RORs specific ligands share some chemical homologies which can be exploited to design a novel molecular structure characterized by a polycyclic core bearing a polar head and a hydrophobic tail. Compound MG 2778 (8), a cyclopenta[a]phenantrene derivative, was identified as lead compound which was chemically modified at position 2 in order to obtain a small library for preliminary SARs. Cell viability and estrogenic activity of compounds 7, 8, 19a, 30, 31 and 32 were evaluated to attest selectivity. The selected 7, 8, 19a and 31 compounds were assayed in a Gal4 UAS-Luc co-transfection system in order to determine their ability to modulate RORγt activity in a cellular environment. They were evaluated as inverse agonists taken ursolic acid as reference compound. The potency of compounds was lower than that of ursolic acid, but their efficacy was similar. Compound 19a was the most active, significantly reducing RORγt activity at low micromolar concentrations. Copyright © 2018 Elsevier Ltd. All rights reserved.

Focused library design and synthesis of 2-mercapto benzothiazole linked 1,2,4-oxadiazoles as COX-2/5-LOX inhibitors

NASA Astrophysics Data System (ADS)

Yatam, Satayanarayana; Gundla, Rambabu; Jadav, Surender Singh; Pedavenkatagari, Narayana reddy; Chimakurthy, Jithendra; Rani B, Namratha; Kedam, Thyagaraju

2018-05-01

Mercapto benzothiazole linked 1,2,4-oxadiazole derivatives were designed (4a-u) as new anti-inflammatory agents using bioisosteric approach and docking studies. The docking results clearly indicated that the compounds 4a-u shown good docking interaction towards COX-2 enzyme. In silico drug-like properties were also calculated for compounds (4a-u) and exhibited significant H-bond acceptor ratio. All compounds were synthesized and biologically evaluated using in vitro COX-1, COX-2 and 5-LOX assays. Compound 4k and 4q (IC50 = 6.8 μM and IC50 = 5.0 μM) found to be potent, selective COX-2 inhibitors and display better anti-inflammatory activity than standard Ibuprofen. Compound 4l and 4e found to be potent inhibitors against 5-LOX (IC50 = 5.1 μM and IC50 = 5.5 μM). The in vivo anti-inflammatory activity studies shown that the compounds 4q and 4k effectively reducing the paw edema volume at 3h and 5h than standard drug Ibuprofen. The DPPH radical scavenging activity provided anti-oxidant activity of compound 4e (IC50 = 25.6 μM) than reference standard Ascorbic acid.

Optical properties of novel environmentally benign biologically active ferrocenyl substituted chromophores: A detailed insight via experimental and theoretical approach

NASA Astrophysics Data System (ADS)

Khan, Salman A.; Asiri, Abdullah M.; Al-Ghamdi, Najat Saeed M.; Zayed, Mohie E. M.; Sharma, Kamlesh; Parveen, Humaira

2017-07-01

Series of ferrocenyl substituted chromophores were synthesized via a reaction of acetyl ferrocene and a variety of aldehyde under microwave irradiation. The structure of synthesized compounds were established by spectroscopic (FT-IR, 1H NMR, 13C NMR, ESI-MS) and elemental analysis. UV-Vis and fluorescence spectroscopy measurements provided that all compounds have good absorbent and fluorescent properties. Fluorescence polarity studies demonstrated that these compounds were sensitive to the polarity of the microenvironment provided by different solvents. In addition, spectroscopic and physicochemical parameters, including singlet absorption, extinction coefficient, Stokes shift, oscillator strength and dipole moment, were investigated in order to explore the analytical potential of the synthesized compounds. The anti-bacterial activity of these compounds were first studied in vitro by the disk diffusion assay against two Gram-positive and two Gram-negative bacteria. The minimum inhibitory concentration was then determined with the reference of standard drug chloramphenicol. The results displayed that compound 3 was better inhibitors for both types of the bacteria (Gram-positive and Gram-negative) than chloramphenicol. Based on the density functional theory; total energy, the atomic orbital contribution to frontier orbitals: LUMO and HOMO, of all synthesized compounds were calculated to support the antibacterial activities.

Bond-based bilinear indices for computational discovery of novel trypanosomicidal drug-like compounds through virtual screening.

PubMed

Castillo-Garit, Juan Alberto; del Toro-Cortés, Oremia; Vega, Maria C; Rolón, Miriam; Rojas de Arias, Antonieta; Casañola-Martin, Gerardo M; Escario, José A; Gómez-Barrio, Alicia; Marrero-Ponce, Yovani; Torrens, Francisco; Abad, Concepción

2015-01-01

Two-dimensional bond-based bilinear indices and linear discriminant analysis are used in this report to perform a quantitative structure-activity relationship study to identify new trypanosomicidal compounds. A data set of 440 organic chemicals, 143 with antitrypanosomal activity and 297 having other clinical uses, is used to develop the theoretical models. Two discriminant models, computed using bond-based bilinear indices, are developed and both show accuracies higher than 86% for training and test sets. The stochastic model correctly indentifies nine out of eleven compounds of a set of organic chemicals obtained from our synthetic collaborators. The in vitro antitrypanosomal activity of this set against epimastigote forms of Trypanosoma cruzi is assayed. Both models show a good agreement between theoretical predictions and experimental results. Three compounds showed IC50 values for epimastigote elimination (AE) lower than 50 μM, while for the benznidazole the IC50 = 54.7 μM which was used as reference compound. The value of IC50 for cytotoxicity of these compounds is at least 5 times greater than their value of IC50 for AE. Finally, we can say that, the present algorithm constitutes a step forward in the search for efficient ways of discovering new antitrypanosomal compounds. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

Fused heterocyclic compounds bearing bridgehead nitrogen as potent HIV-1 NNRTIs. Part 1: design, synthesis and biological evaluation of novel 5,7-disubstituted pyrazolo[1,5-a]pyrimidine derivatives.

PubMed

Tian, Ye; Du, Deping; Rai, Diwakar; Wang, Liu; Liu, Huiqing; Zhan, Peng; De Clercq, Erik; Pannecouque, Christophe; Liu, Xinyong

2014-04-01

In our continuous efforts to identify novel potent HIV-1 NNRTIs, a novel class of 5,7-disubstituted pyrazolo[1,5-a]pyrimidine derivatives were rationally designed, synthesized and evaluated for their anti-HIV activities in MT4 cell cultures. Biological results showed that most of the tested compounds displayed excellent activity against wild-type HIV-1 with a wide range of EC50 values from 5.98 to 0.07μM. Among the active compounds, 5a was found to be the most promising analogue with an EC50 of 0.07μM against wild-type HIV-1 and very high selectivity index (SI, 3999). Compound 5a was more effective than the reference drugs nevirapine (by 2-fold) and delavirdine (by 2-fold). In order to further confirm their binding target, an HIV-1 RT inhibitory assay was also performed. Furthermore, SAR analysis among the newly synthesized compounds was discussed and the binding mode of the active compound 5a was rationalized by molecular modeling studies. Copyright © 2014 Elsevier Ltd. All rights reserved.

Application of ionic liquid for extraction and separation of bioactive compounds from plants.

PubMed

Tang, Baokun; Bi, Wentao; Tian, Minglei; Row, Kyung Ho

2012-09-01

In recent years, ionic liquids (ILs), as green and designer solvents, have accelerated research in analytical chemistry. This review highlights some of the unique properties of ILs and provides an overview of the preparation and application of IL or IL-based materials to extract bioactive compounds in plants. IL or IL-based materials in conjunction with liquid-liquid extraction (LLE), ultrasonic-assisted extraction (UAE), microwave-assisted extraction (MAE), high performance liquid chromatography (HPLC) and solid-phase extraction (SPE) analytical technologies etc., have been applied successfully to the extraction or separation of bioactive compounds from plants. This paper reviews the available data and references to examine the advantages of IL and IL-based materials in these applications. In addition, the main target compounds reviewed in this paper are bioactive compounds with multiple therapeutic effects and pharmacological activities. Based on the importance of the targets, this paper reviews the applications of ILs, IL-based materials or co-working with analytical technologies. The exploitation of new applications of ILs on the extraction of bioactive compounds from plant samples is expected to increase. Copyright © 2012 Elsevier B.V. All rights reserved.

One-Pot Synthesis, Spectroscopic and Physicochemical Studies of Quinoline Based Blue Emitting Donor-Acceptor Chromophores with Their Biological Application.

PubMed

Asiri, Abdullah M; Khan, Salman A; Al-Thaqafya, Saad H

2015-09-01

Blue emitting cyano substituted isoquinoline dyes were synthesized by one-pot multicomponent reactions (MCRs) of aldehydes, malononitrile, 6-methoxy-1,2,3,4-tetrahydro-naphthalin-1-one and ammonium acetate. Results obtained from spectroscopic (FT-IR, (1)H-NMR, (13)C-NMR, EI-MS) and elemental analysis of synthesized compounds was in good agreement with their chemical structures. UV-vis and fluorescence spectroscopy measurements proved that all compounds are good absorbent and fluorescent. Fluorescence polarity study demonstrated that these compounds were sensitive to the polarity of the microenvironment provided by different solvents. In addition, spectroscopic and physicochemical parameters, including electronic absorption, excitation coefficient, stokes shift, oscillator strength, transition dipole moment and fluorescence quantum yield were investigated in order to explore the analytical potential of synthesized compounds. The anti-bacterial activity of these compounds were first studied in vitro by the disk diffusion assay against two Gram-positive and two Gram-negative bacteria then the minimum inhibitory concentration (MIC) was determined with the reference of standard drug chloramphenicol. The results displayed that compound 3 was better inhibitors of both types of the bacteria (Gram-positive and Gram-negative) than chloramphenicol. Graphical Abstract ᅟ.

Carbonaceous meteorites as a source of sugar-related organic compounds for the early Earth

NASA Technical Reports Server (NTRS)

Cooper, G.; Kimmich, N.; Belisle, W.; Sarinana, J.; Brabham, K.; Garrel, L.

2001-01-01

The much-studied Murchison meteorite is generally used as the standard reference for organic compounds in extraterrestrial material. Amino acids and other organic compounds important in contemporary biochemistry are thought to have been delivered to the early Earth by asteroids and comets, where they may have played a role in the origin of life. Polyhydroxylated compounds (polyols) such as sugars, sugar alcohols and sugar acids are vital to all known lifeforms-they are components of nucleic acids (RNA, DNA), cell membranes and also act as energy sources. But there has hitherto been no conclusive evidence for the existence of polyols in meteorites, leaving a gap in our understanding of the origins of biologically important organic compounds on Earth. Here we report that a variety of polyols are present in, and indigenous to, the Murchison and Murray meteorites in amounts comparable to amino acids. Analyses of water extracts indicate that extraterrestrial processes including photolysis and formaldehyde chemistry could account for the observed compounds. We conclude from this that polyols were present on the early Earth and therefore at least available for incorporation into the first forms of life.

Comparative analysis of volatiles in traditionally cured Bourbon and Ugandan vanilla bean ( Vanilla planifolia ) extracts.

PubMed

Zhang, Suying; Mueller, Christoph

2012-10-24

Traditionally cured vanilla beans ( Vanilla planifolia ) from Madagascar and Uganda were extracted with organic solvents, and the volatiles were separated from the nonvolatile fraction using the solvent assisted flavor evaporation (SAFE) technique. Concentrated vanilla bean extracts were analyzed using GC-MS and GC-O. Two hundred and forty-six volatile compounds were identified using the Automated Mass Spectral Deconvolution and Identification System (AMDIS) software, of which 13 were confirmed with authentic compounds from commercial sources and the others were tentatively identified on the basis of calibrated linear retention indices and the comparison of deconvoluted mass spectra with the in-house and/or NIST spectra databases. Vanillin was the most abundant constituent followed by guaiacol. The total concentration of the volatile compounds, excluding vanillin, was 301 mg/kg for Bourbon and 398 mg/kg for Ugandan vanilla bean extracts. Analytical comparison between the two vanilla bean extracts was discussed. Seventy-eight compounds were identified as odor-active compounds in the vanilla bean extracts with 10 confirmed with authentic references. It was found that there were substantial analytical differences in the odor-active compounds of the two extracts.

Effect of Different Germination Conditions on Antioxidative Properties and Bioactive Compounds of Germinated Brown Rice

PubMed Central

Lin, You-Tung; Pao, Cheng-Cheng; Wu, Shwu-Tzy; Chang, Chi-Yue

2015-01-01

This study investigates antioxidative activity and bioactive compounds of ungerminated brown rice (UBR) and germinated brown rice (GBR). We used two rice cultivars (Oryza sativa L.), Taiwan Japonica 9 (TJ-9) and Taichung Indica 10 (TCI-10), as the materials in our experiments. The conditions for inducing germination are soaking time in water 24, 48, or 72 h; temperature 26 or 36°C; incubation in light or darkness; and open or closed vessels, in which the antioxidative activities and bioactive compounds of GBR were determined. We found that, in order to maximize antioxidative activity and bioactive compounds, germination should be under higher temperature (36°C), long soaking time (72 h), darkness, and closed vessel. GBR contains much higher levels of antioxidative activity and bioactive compounds than ungerminated brown rice (UBR). We found a strong correlation between antioxidative activities (DPPH radical scavenging ability, reducing power, and Trolox equivalent antioxidant capacity) and bioactive compounds (γ-oryzanols, tocopherol, and tocotrienol). Higher temperature (36°C) is also conducive to the production of GABA in GBR. These results are considered very useful research references for the development of future functional foods and additives. PMID:25861637

Synthesis of 1,2,4-triazole-linked urea/thiourea conjugates as cytotoxic and apoptosis inducing agents.

PubMed

Tokala, Ramya; Bale, Swarna; Janrao, Ingle Pavan; Vennela, Aluri; Kumar, Niggula Praveen; Senwar, Kishna Ram; Godugu, Chandraiah; Shankaraiah, Nagula

2018-06-01

A new series of 1,2,4-triazole-linked urea and thiourea conjugates have been synthesized and evaluated for their in vitro cytotoxicity against selected human cancer cell lines namely, breast (MCF-7, MDA-MB-231), lung (A549) prostate (DU145) and one mouse melanoma (B16-F10) cell line and compared with reference drug. The compound 5t showed significant cytotoxicity on MCF-7 breast cancer cell line with a IC 50 value of 7.22 ± 0.47 µM among all the tested compounds. Notably, induction of apoptosis by compound 5t on MCF-7 cells was evaluated using different staining techniques such as acridine orange/ethidium bromide (AO/EB), annexin V-FITC/PI, and DAPI. Further, clonogenic assay indicates the inhibition of colony formation on MCF-7 cells by compound 5t. Moreover, the flow-cytometric analysis also revealed that compound 5t caused the arrest of cells at G0/G1 phase of cell cycle. In addition, the compounds when tested on normal human cells (L-132) were found to be safer with low cytotoxicity profile. Copyright © 2018 Elsevier Ltd. All rights reserved.

Quantum probability ranking principle for ligand-based virtual screening.

PubMed

Al-Dabbagh, Mohammed Mumtaz; Salim, Naomie; Himmat, Mubarak; Ahmed, Ali; Saeed, Faisal

2017-04-01

Chemical libraries contain thousands of compounds that need screening, which increases the need for computational methods that can rank or prioritize compounds. The tools of virtual screening are widely exploited to enhance the cost effectiveness of lead drug discovery programs by ranking chemical compounds databases in decreasing probability of biological activity based upon probability ranking principle (PRP). In this paper, we developed a novel ranking approach for molecular compounds inspired by quantum mechanics, called quantum probability ranking principle (QPRP). The QPRP ranking criteria would make an attempt to draw an analogy between the physical experiment and molecular structure ranking process for 2D fingerprints in ligand based virtual screening (LBVS). The development of QPRP criteria in LBVS has employed the concepts of quantum at three different levels, firstly at representation level, this model makes an effort to develop a new framework of molecular representation by connecting the molecular compounds with mathematical quantum space. Secondly, estimate the similarity between chemical libraries and references based on quantum-based similarity searching method. Finally, rank the molecules using QPRP approach. Simulated virtual screening experiments with MDL drug data report (MDDR) data sets showed that QPRP outperformed the classical ranking principle (PRP) for molecular chemical compounds.

Extraction and determination of bioactive compounds from bee pollen.

PubMed

Ares, Ana M; Valverde, Silvia; Bernal, José L; Nozal, María J; Bernal, José

2018-01-05

Since ancient times bee pollen has been considered a good source of bioactive substances and energy. Taking into account the current demand for healthy and natural foods, it is not surprising that bee pollen has been attracting commercial interest in recent years, making it one of the most widely consumed food supplements. It has been extensively reported that bee pollen contains several health-promoting compounds, such as proteins, amino acids, lipids, phenolic compounds, vitamins or minerals. Thus, this study aims to give an overview of the extraction and determination techniques of several of the above-mentioned compounds which have been published in the last few years (2011-2017). The design of the study is in accordance with the different families of bioactive compounds, and the extraction procedures together with the analytical techniques employed and their determination are discussed. A list of some of the most relevant applications is provided for each category, including a brief summary of the experimental conditions. The references included will provide the reader with a comprehensive overview of and insight into the analysis of bioactive compounds from bee pollen. Copyright © 2017 Elsevier B.V. All rights reserved.

Synthesis of aryl pyrazole via Suzuki coupling reaction, in vitro mushroom tyrosinase enzyme inhibition assay and in silico comparative molecular docking analysis with Kojic acid.

PubMed

Channar, Pervaiz Ali; Saeed, Aamer; Larik, Fayaz Ali; Batool, Bakhtawar; Kalsoom, Saima; Hasan, M M; Erben, Mauricio F; El-Seedi, Hesham R; Ali, Musrat; Ashraf, Zaman

2018-04-30

Aryl pyrazoles are well recognized class of heterocyclic compounds found in several commercially available drugs. Owing to their significance in medicinal chemistry, in this current account we have synthesized a series of suitably substituted aryl pyrazole by employing Suzuki cross-coupling reaction. All compounds were evaluated for inhibition of mushroom tyrosinase enzyme both in vitro and in silico. Compound 3f (IC 50  = 1.568 ± 0.01 µM) showed relatively better potential compared to reference kojic acid (IC 50  = 16.051 ± 1.27 µM). A comparative docking studies showed that compound 3f have maximum binding affinity against mushroom tyrosinase (PDBID: 2Y9X) with binding energy value (-6.90 kcal/mol) as compared to Kojic acid. The 4-methoxy group in compound 3f shows 100% interaction with Cu. Compound 3f displayed hydrogen binding interaction with His61 and His94 at distance of 1.71 and 1.74 Å which might be responsible for higher activity compared to Kojic acid. Copyright © 2018 Elsevier Inc. All rights reserved.

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

NASA Astrophysics Data System (ADS)

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

2015-01-01

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

Quantum probability ranking principle for ligand-based virtual screening

NASA Astrophysics Data System (ADS)

Al-Dabbagh, Mohammed Mumtaz; Salim, Naomie; Himmat, Mubarak; Ahmed, Ali; Saeed, Faisal

2017-04-01

Chemical libraries contain thousands of compounds that need screening, which increases the need for computational methods that can rank or prioritize compounds. The tools of virtual screening are widely exploited to enhance the cost effectiveness of lead drug discovery programs by ranking chemical compounds databases in decreasing probability of biological activity based upon probability ranking principle (PRP). In this paper, we developed a novel ranking approach for molecular compounds inspired by quantum mechanics, called quantum probability ranking principle (QPRP). The QPRP ranking criteria would make an attempt to draw an analogy between the physical experiment and molecular structure ranking process for 2D fingerprints in ligand based virtual screening (LBVS). The development of QPRP criteria in LBVS has employed the concepts of quantum at three different levels, firstly at representation level, this model makes an effort to develop a new framework of molecular representation by connecting the molecular compounds with mathematical quantum space. Secondly, estimate the similarity between chemical libraries and references based on quantum-based similarity searching method. Finally, rank the molecules using QPRP approach. Simulated virtual screening experiments with MDL drug data report (MDDR) data sets showed that QPRP outperformed the classical ranking principle (PRP) for molecular chemical compounds.

Synthesis, pharmacological evaluation and molecular docking studies of pyrimidinedione based DPP-4 inhibitors as antidiabetic agents

NASA Astrophysics Data System (ADS)

Jha, Vibhu; Bhadoriya, Kamlendra Singh

2018-04-01

Dipeptidyl peptidase-4 (DPP-4) inhibitors are a class of newly developed antidiabetic drugs that bock DPP-4. DPP-4 is responsible for degradation of incretins harmones such as GLP-1 (Glucagon like Peptide) and GIP (Gastric inhibitory polypeptide) that maintain blood-glucose level. Pyrimidinedione based compounds were designed and synthesized for DPP-4 inhibitory activity. These heterocycles were designed by taking Alogliptin as a reference DPP-4 inhibitors and synthesized as N-methylated and N-benzylated pyrimidinediones. These compounds were subjected to DPP-4 assay, five out of nine synthesized compounds have shown in vitro DPP-4 inhibitory activity in significant range. Further, molecular docking studies of these compounds were performed on DPP-4 subunit and compared with natural DPP-4 inhibitors like Flavone, Resveratrol, Quercetin, Diprotin A. Docking studies have led to the conclusion that there are some identical amino acid interactions as Tyr 666 and Tyr 662, seen in both synthesized compounds and natural DPP-4 inhibitors. This study completely gives a good scope for further derivatisation and optimization of synthesized compounds to get clinical candidate as DPP-4 inhibitor for antidiabetic activity.

Synthesis, Characterization, Antimicrobial and Antioxidant Activities of The Homocyclotrimer Of 4-Oxo-4h-Thieno[3,4-C]Chromene-3-Diazonium Sulfate.

PubMed

Sopbue Fondjo, Emmanuel; Sorel, Djeukoua Dimo Kamal; Jean-de-Dieu, Tamokou; Joseph, Tsemeugne; Sylvian, Kouamo; Doriane, Ngouanet; Rodolphe, Chouna Jean; Pepin, Nkeng-Efouet-Alango; Jules-Roger, Kuiate; Arnaud, Ngongang Ndjintchui; Lucas, Sondengam Beibam

2016-01-01

The in situ formed 4-oxo-4H-thieno[3,4-c]chromene-3-diazonium sulfate (5) in the coupling reactions involving the parent 2-aminothiophene (4) and various phenolic and arylamines' couplers, readily undergoes homocyclotrimerization at low temperature to afford in fairly good yield the first ever reported eighteen member ring heteroaromatic holigomer 6. Compound 6 was fully characterized by its elemental analysis, IR, UV-Vis, (1)H-NMR, (13)C-NMR and HRMS spectral data. The HMBC and HSQC techniques were used to ascertain the structural assignments. A comparative study on the antimicrobial and antioxidant activities of compounds 3, 4 and 6 was carried out to assess the SAR due to the transformations (from 3 to 6 via 4) on the tested compounds. It was found that compounds 6 and 4 were respectively the most active compounds against bacteria (MIC = 32-64 μg/ml) and yeasts (MIC = 16-64 μg/ml). Compound 6 also showed high radical-scavenging activities and ferric reducing power when compared with vitamin C and BHT used as reference antioxidants.

Synthesis, Characterization, Antimicrobial and Antioxidant Activities of The Homocyclotrimer Of 4-Oxo-4h-Thieno[3,4-C]Chromene-3-Diazonium Sulfate

PubMed Central

Sopbue Fondjo, Emmanuel; Sorel, Djeukoua Dimo Kamal; Jean-de-Dieu, Tamokou; Joseph, Tsemeugne; Sylvian, Kouamo; Doriane, Ngouanet; Rodolphe, Chouna Jean; Pepin, Nkeng-Efouet-Alango; Jules-Roger, Kuiate; Arnaud, Ngongang Ndjintchui; Lucas, Sondengam Beibam

2016-01-01

The in situ formed 4-oxo-4H-thieno[3,4-c]chromene-3-diazonium sulfate (5) in the coupling reactions involving the parent 2-aminothiophene (4) and various phenolic and arylamines’ couplers, readily undergoes homocyclotrimerization at low temperature to afford in fairly good yield the first ever reported eighteen member ring heteroaromatic holigomer 6. Compound 6 was fully characterized by its elemental analysis, IR, UV-Vis, 1H-NMR, 13C-NMR and HRMS spectral data. The HMBC and HSQC techniques were used to ascertain the structural assignments. A comparative study on the antimicrobial and antioxidant activities of compounds 3, 4 and 6 was carried out to assess the SAR due to the transformations (from 3 to 6 via 4) on the tested compounds. It was found that compounds 6 and 4 were respectively the most active compounds against bacteria (MIC = 32-64 μg/ml) and yeasts (MIC = 16–64 μg/ml). Compound 6 also showed high radical-scavenging activities and ferric reducing power when compared with vitamin C and BHT used as reference antioxidants. PMID:27583034

A Model Study to Unravel the Complexity of Bio-Oil from Organic Wastes.

PubMed

Croce, Annamaria; Battistel, Ezio; Chiaberge, Stefano; Spera, Silvia; De Angelis, Francesco; Reale, Samantha

2017-01-10

Binary and ternary mixtures of cellulose, bovine serum albumin (BSA) and tripalmitin, as biomass reference compounds for carbohydrates, proteins and triglycerides, respectively, were treated under hydrothermal liquefaction (HTL) conditions to describe the main reaction pathways involved in the process of bio-oil production from municipal organic wastes. Several analytical techniques (elemental analysis, GC-MS, atmospheric-pressure photo-ionisation high-resolution Fourier transform ion cyclotron resonance mass spectrometry, and 13 C cross-polarisation magic-angle spinning NMR spectroscopy) were used for the molecular-level characterisation of the resulting aqueous phase, solid residue and bio-oil, in particular. The main reaction pathways led to free fatty acids, fatty acid amides, 2,5-diketopiperazines and Maillard-type compounds as the main components of the bio-oil. The relationship of such compounds to the original components of the biomass was thus determined, which highlights the fate of the heteroatom-containing molecules in particular. Finally, the molecular composition of the bio-oils from our reference compounds was matched with that of the bio-oil from municipal organic waste biomass by comparing their high-resolution Fourier transform ion cyclotron resonance mass spectra, and we obtained a surprisingly high similarity. Hence, the ternary mixture acts as a reliable biomass model and is a powerful tool to clarify the degradation mechanisms that occur in the biomass under HTL treatment, with the ultimate goal to improve the HTL process itself by modulating the input of the organic starting matter and then the upgrading steps to bio-fuels. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Extended evaluation on the ES-D3 cell differentiation assay combined with the BeWo transport model, to predict relative developmental toxicity of triazole compounds.

PubMed

Li, Hequn; Flick, Burkhard; Rietjens, Ivonne M C M; Louisse, Jochem; Schneider, Steffen; van Ravenzwaay, Bennard

2016-05-01

The mouse embryonic stem D3 (ES-D3) cell differentiation assay is based on the morphometric measurement of cardiomyocyte differentiation and is a promising tool to detect developmental toxicity of compounds. The BeWo transport model, consisting of BeWo b30 cells grown on transwell inserts and mimicking the placental barrier, is useful to determine relative placental transport velocities of compounds. We have previously demonstrated the usefulness of the ES-D3 cell differentiation assay in combination with the in vitro BeWo transport model to predict the relative in vivo developmental toxicity potencies of a set of reference azole compounds. To further evaluate this combined in vitro toxicokinetic and toxicodynamic approach, we combined ES-D3 cell differentiation data of six novel triazoles with relative transport rates obtained from the BeWo model and compared the obtained ranking to the developmental toxicity ranking as derived from in vivo data. The data show that the combined in vitro approach provided a correct prediction for in vivo developmental toxicity, whereas the ES-D3 cell differentiation assay as stand-alone did not. In conclusion, we have validated the combined in vitro approach for developmental toxicity, which we have previously developed with a set of reference azoles, for a set of six novel triazoles. We suggest that this combined model, which takes both toxicodynamic and toxicokinetic aspects into account, should be further validated for other chemical classes of developmental toxicants.

Identification of flavour additives in tobacco products to develop a flavour library

PubMed Central

Krüsemann, Erna JZ; Visser, Wouter F; Cremers, Johannes WJM; Pennings, Jeroen LA; Talhout, Reinskje

2018-01-01

Objectives This study combines chemical analysis and flavour descriptions of flavour additives used in tobacco products, and provides a starting point to build an extensive library of flavour components, useful for product surveillance. Methods Headspace gas chromatography-mass spectrometry (GC-MS) was used to compare 22 commercially available tobacco products (cigarettes and roll-your-own) expected to have a characterising flavour and 6 commercially available products not expected to have a characterising flavour with 5 reference products (natural tobacco leaves and research cigarettes containing no flavour additives). The flavour components naturally present in the reference products were excluded from components present in commercially available products containing flavour additives. A description of the remaining flavour additives was used for categorisation. Results GC-MS measurements of the 33 tobacco products resulted in an overview of 186 chemical compounds. Of these, 144 were solely present in commercially available products. These 144 flavour additives were described using 62 different flavour descriptors extracted from flavour databases, which were categorised into eight groups largely based on the definition of characterising flavours from the European Tobacco Product Directive: fruit, spice, herb, alcohol, menthol, sweet, floral and miscellaneous. Conclusions We developed a method to identify and describe flavour additives in tobacco products. Flavour additives consist of single flavour compounds or mixtures of multiple flavour compounds, and different combinations of flavour compounds can cause a certain flavour. A flavour library helps to detect flavour additives that are characteristic for a certain flavour, and thus can be useful for regulation of flavours in tobacco and related products. PMID:28190004

PM: RESEARCH METHODS FOR PM TOXIC COMPOUNDS - PARTICLE METHODS EVALUATION AND DEVELOPMENT

EPA Science Inventory

The Federal Reference Method (FRM) for Particulate Matter (PM) developed by EPA's National Exposure Research Laboratory (NERL) forms the backbone of the EPA's national monitoring strategy. It is the measurement that defines attainment of the National Ambient Air Quality Standard...

Activity, purification, and analysis of condensed tannins

USDA-ARS?s Scientific Manuscript database

As a class of plant polyphenolic compounds contained in some forages (i.e., sanfoin, big trefoil, birdfoot trefoil), condensed tannins (CTs), also referred to as proanthocyanidins (PAs), exhibit a variety of biological effects on ruminants and on the dairy farm nitrogen cycle. Interest in CTs stems ...

ECONOMIC GROWTH ANALYSIS SYSTEM: REFERENCE MANUAL VERSION 2.0

EPA Science Inventory

The two-volume report describes the development of and provides information needed to operate, the Economic Growth Analysis System (E-GAS) Version 2.0 model. The model will be used to project emissions inventories of volatile organic compounds (VOCs), oxides of nitrogen (NOx), a...

ECONOMIC GROWTH ANALYSIS SYSTEM: REFERENCE MANUAL VERSION 3.0

EPA Science Inventory

The two-volume report describes the development of, and provides information needed to operate, the Economic Growth Analysis System (E-GAS) Version 3.0 model. The model will be used to project emissions inventories of volatile organic compounds, oxides of nitrogen, and carbon mon...

A Reference Method for Measuring Emissions of SVOCs in Small Chambers

EPA Science Inventory

Semivolatile organic compounds (SVOCs) are indoor air pollutants that may may have significant adverse effects on human health, and emission of SVOCs from building materials and consumer products is of growing concern. Few chamber studies have been conducted due to the challenge...

40 CFR 60.201 - Definitions.

Code of Federal Regulations, 2014 CFR

2014-07-01

...-Process Phosphoric Acid Plants § 60.201 Definitions. As used in this subpart, all terms not defined herein... acid plant means any facility manufacturing phosphoric acid by reacting phosphate rock and acid. (b) Total fluorides means elemental fluorine and all fluoride compounds as measured by reference methods...

40 CFR 60.201 - Definitions.

Code of Federal Regulations, 2011 CFR

2011-07-01

...-Process Phosphoric Acid Plants § 60.201 Definitions. As used in this subpart, all terms not defined herein... acid plant means any facility manufacturing phosphoric acid by reacting phosphate rock and acid. (b) Total fluorides means elemental fluorine and all fluoride compounds as measured by reference methods...

40 CFR 60.201 - Definitions.

Code of Federal Regulations, 2012 CFR

2012-07-01

...-Process Phosphoric Acid Plants § 60.201 Definitions. As used in this subpart, all terms not defined herein... acid plant means any facility manufacturing phosphoric acid by reacting phosphate rock and acid. (b) Total fluorides means elemental fluorine and all fluoride compounds as measured by reference methods...

40 CFR 60.201 - Definitions.

Code of Federal Regulations, 2013 CFR

2013-07-01

...-Process Phosphoric Acid Plants § 60.201 Definitions. As used in this subpart, all terms not defined herein... acid plant means any facility manufacturing phosphoric acid by reacting phosphate rock and acid. (b) Total fluorides means elemental fluorine and all fluoride compounds as measured by reference methods...

40 CFR 60.201 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-07-01

...-Process Phosphoric Acid Plants § 60.201 Definitions. As used in this subpart, all terms not defined herein... acid plant means any facility manufacturing phosphoric acid by reacting phosphate rock and acid. (b) Total fluorides means elemental fluorine and all fluoride compounds as measured by reference methods...

Online Determination of Trace Amounts of Tannic Acid in Colored Tannery Wastewaters by Automatic Reference Flow Injection Analysis

PubMed Central

Wei, Liang

2010-01-01

A simple, rapid and sensitive method was proposed for online determination of tannic acid in colored tannery wastewater by automatic reference flow injection analysis. Based on the tannic acid reduction phosphotungstic acid to form blue compound in pH 12.38 alkaline solutions, the shade of blue compound is in a linear relation to the content of tannic acid at the point of the maximum absorption peak of 760 nm. The optimal experimental conditions had been obtained. The linear range of the proposed method was between 200 μg L−1 to 80 mg L−1 and the detection limit was 0.58 μg L−1. The relative standard deviation was 3.08% and 2.43% for 500 μg L−1 and 40 mg L−1 of tannic acid standard solution, respectively, (n = 10). The method had been successfully applied to determination of tannic acid in colored tannery wastewaters and the analytical results were satisfactory. PMID:20508812

Design and Synthesis of 2-Heterocyclyl-3-arylthio-1H-indoles as Potent Tubulin Polymerization and Cell Growth Inhibitors with Improved Metabolic Stability

PubMed Central

La Regina, Giuseppe; Bai, Ruoli; Rensen, Willeke; Coluccia, Antonio; Piscitelli, Francesco; Gatti, Valerio; Bolognesi, Alessio; Lavecchia, Antonio; Granata, Ilaria; Porta, Amalia; Maresca, Bruno; Soriani, Alessandra; Iannitto, Maria Luisa; Mariani, Marisa; Santoni, Angela; Brancale, Andrea; Ferlini, Cristiano; Dondio, Giulio; Varasi, Mario; Mercurio, Ciro; Hamel, Ernest; Lavia, Patrizia; Novellino, Ettore; Silvestri, Romano

2011-01-01

New arylthioindoles (ATIs) were obtained by replacing the 2-alkoxycarbonyl group with a bioisosteric 5-membered heterocycle nucleus. The new ATIs 5, 8, and 10 inhibited tubulin polymerization, reduced cell growth of a panel of human transformed cell lines, and showed higher metabolic stability than the reference ester 3. These compounds induced mitotic arrest and apoptosis at a similar level as combretastatin A-4 and vinblastine and triggered caspase-3 expression in a significant fraction of cells in both p53-proficient and p53-defective cell lines. Importantly, ATIs 5, 8, and 10 were more effective than vinorelbine, vinblastine, and paclitaxel as growth inhibitors of the P-glycoprotein-overexpressing cell line NCI/ADR-RES. Compound 5 was shown to have medium metabolic stability in both human and mouse liver microsomes, in contrast to the rapidly degraded reference ester 3, and a pharmacokinetic profile in the mouse characterized by a low systemic clearance and excellent oral bioavailability. PMID:22044164

EPA's Reanalysis of Key Issues Related to Dioxin Toxicity and ...

EPA Pesticide Factsheets

EPA is releasing for external peer review and public comment an important draft document reviewing the literature on the health effects of dioxin and related compounds (also referred to as 2,3,7,8-Tetrachlorodibenzo-p-dioxin). At the request of Administrator Jackson, EPA is in the process of re-assessing the science on the effects of dioxin, a toxic chemical that is emitted by multiple sources, on the public’s health. This draft dioxin report is EPA’s response to key comments and recommendations made by the National Academy of Sciences on the Agency’s draft dioxin reassessment. This assessment has been in progress for many years and raises health issues of broad interest to scientists and policymakers across the federal family. The Agency’s draft report includes significant new analyses on potential cancer and non-cancer human health effects that may result from exposures to dioxins and includes an oral reference dose for what is considered to be the most toxic of the dioxin-like compounds. EPA’s Science

Syntheses of precursors and reference compounds of the melanin-concentrating hormone receptor 1 (MCHR1) tracers [¹¹C]SNAP-7941 and [¹⁸F]FE@SNAP for positron emission tomography.

PubMed

Schirmer, Eva; Shanab, Karem; Datterl, Barbara; Neudorfer, Catharina; Mitterhauser, Markus; Wadsak, Wolfgang; Philippe, Cécile; Spreitzer, Helmut

2013-09-30

The MCH receptor has been revealed as a target of great interest in positron emission tomography imaging. The receptor's eponymous substrate melanin-concentrating hormone (MCH) is a cyclic peptide hormone, which is located predominantly in the hypothalamus with a major influence on energy and weight regulation as well as water balance and memory. Therefore, it is thought to play an important role in the pathophysiology of adiposity, which is nowadays a big issue worldwide. Based on the selective and high-affinity MCH receptor 1 antagonist SNAP-7941, a series of novel SNAP derivatives has been developed to provide different precursors and reference compounds for the radiosyntheses of the novel PET radiotracers [(11)C]SNAP-7941 and [(18)F]FE@SNAP. Positron emission tomography promotes a better understanding of physiologic parameters on a molecular level, thus giving a deeper insight into MCHR1 related processes as adiposity.

QSPR model for bioconcentration factors of nonpolar organic compounds using molecular electronegativity distance vector descriptors.

PubMed

Qin, Li-Tang; Liu, Shu-Shen; Liu, Hai-Ling

2010-02-01

A five-variable model (model M2) was developed for the bioconcentration factors (BCFs) of nonpolar organic compounds (NPOCs) by using molecular electronegativity distance vector (MEDV) to characterize the structures of NPOCs and variable selection and modeling based on prediction (VSMP) to select the optimum descriptors. The estimated correlation coefficient (r (2)) and the leave-one-out cross-validation correlation coefficients (q (2)) of model M2 were 0.9271 and 0.9171, respectively. The model was externally validated by splitting the whole data set into a representative training set of 85 chemicals and a validation set of 29 chemicals. The results show that the main structural factors influencing the BCFs of NPOCs are -cCc, cCcc, -Cl, and -Br (where "-" refers to a single bond and "c" refers to a conjugated bond). The quantitative structure-property relationship (QSPR) model can effectively predict the BCFs of NPOCs, and the predictions of the model can also extend the current BCF database of experimental values.

Accurate mass measurement by matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry. II. Measurement of negative radical ions using porphyrin and fullerene standard reference materials.

PubMed

Shao, Zhecheng; Wyatt, Mark F; Stein, Bridget K; Brenton, A Gareth

2010-10-30

A method for the accurate mass measurement of negative radical ions by matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOFMS) is described. This is an extension to our previously described method for the accurate mass measurement of positive radical ions (Griffiths NW, Wyatt MF, Kean SD, Graham AE, Stein BK, Brenton AG. Rapid Commun. Mass Spectrom. 2010; 24: 1629). The porphyrin standard reference materials (SRMs) developed for positive mode measurements cannot be observed in negative ion mode, so fullerene and fluorinated porphyrin compounds were identified as effective SRMs. The method is of immediate practical use for the accurate mass measurement of functionalised fullerenes, for which negative ion MALDI-TOFMS is the principal mass spectrometry characterisation technique. This was demonstrated by the accurate mass measurement of six functionalised C(60) compounds. Copyright © 2010 John Wiley & Sons, Ltd.

Identification of the monobrominated derivative of Acid Red 52 (Food Red No. 106) in pickled vegetables.

PubMed

Ochi, Naoki; Okuda, Tetsuya; Fujii, Hisashi

2016-09-01

Two unknown dyes (purple and purplish-red) were detected by TLC in two pickled vegetable (sakura-zuke daikon) samples containing Acid Red 52 (AR) and New Coccine as food colorants. HPLC with diode-array detection and LC/MS analyses suggested that the purple dye is monobrominated AR and the purplish-red dye is its N-desethyl derivative, which would be generated mainly during sample preparation. For the identification of the purple dye, a reference compound was prepared by bromination of AR followed by isolation of the monobrominated AR, the structure of which was elucidated as 4'-brominated AR (4'BrAR) by LC/ToF-MS and (1)H-NMR spectroscopy. The purple dye was confirmed as 4'BrAR by comparison of its retention time, ultraviolet-visible spectrum and mass spectrum with those of the prepared reference compound. To our knowledge, this is the first report of the detection of 4'BrAR in foods.

Synthesis and Anti-microbial Activity of Novel Phosphatidylethanolamine-N-amino Acid Derivatives.

PubMed

Vijeetha, Tadla; Balakrishna, Marrapu; Karuna, Mallampalli Sri Lakshmi; Surya Koppeswara Rao, Bhamidipati Venkata; Prasad, Rachapudi Badari Narayana; Kumar, Koochana Pranay; Surya Narayana Murthy, Upadyaula

2015-01-01

The study involved synthesis of five novel amino acid derivatives of phosphatidylethanolamine isolated from egg yolk lecithin employing a three step procedure i) N-protection of L-amino acids with BOC anhydride in alkaline medium ii) condensation of - CO2H group of N-protected amino acid with free -NH2 of PE by a peptide linkage and iii) deprotection of N-protected group of amino acids to obtain phosphatidylethanolamine-N-amino acid derivatives in 60-75% yield. The five L-amino acids used were L glycine, L-valine, L-leucine, L-isoleucine and L-phenylalanine. The amino acid derivatives were screened for anti-baterial activity against B. subtilis, S. aureus, P. aeroginosa and E. coli taking Streptomycin as reference compound and anti-fungal activity against C. albicans, S. cervisiae, A. niger taking AmphotericinB as reference compound. All the amino acid derivatives exhibited extraordinary anti-bacterial activities about 3 folds or comparable to Streptomycin and moderate or no anti-fungal activity against Amphotericin-B.

LC-MS/MS-based approach for obtaining exposure estimates of metabolites in early clinical trials using radioactive metabolites as reference standards.

PubMed

Zhang, Donglu; Raghavan, Nirmala; Chando, Theodore; Gambardella, Janice; Fu, Yunlin; Zhang, Duxi; Unger, Steve E; Humphreys, W Griffith

2007-12-01

An LC-MS/MS-based approach that employs authentic radioactive metabolites as reference standards was developed to estimate metabolite exposures in early drug development studies. This method is useful to estimate metabolite levels in studies done with non-radiolabeled compounds where metabolite standards are not available to allow standard LC-MS/MS assay development. A metabolite mixture obtained from an in vivo source treated with a radiolabeled compound was partially purified, quantified, and spiked into human plasma to provide metabolite standard curves. Metabolites were analyzed by LC-MS/MS using the specific mass transitions and an internal standard. The metabolite concentrations determined by this approach were found to be comparable to those determined by valid LC-MS/MS assays. This approach does not requires synthesis of authentic metabolites or the knowledge of exact structures of metabolites, and therefore should provide a useful method to obtain early estimates of circulating metabolites in early clinical or toxicological studies.

Spectral Analysis of 3-(Adamantan-1-yl)-4-Ethyl-1-[(4-Phenylpiperazin-1-yl) Methyl]-1 H-1,2,4-Triazole-5(4 H)-Thione

NASA Astrophysics Data System (ADS)

Mindarava, Y. L.; Shundalau, M. B.; Al-Wahaibi, L. H.; El-Emam, A. A.; Matsukovich, A. S.; Gaponenko, S. V.

2018-05-01

Vibrational IR (3200-650 cm-1) and Raman spectra (3200-150 cm-1) of adamantane-containing 3-(adamantan-1-yl)-4-ethyl-1-[(4-phenylpiperazin-1-yl)methyl]-1H-1,2,4-triazole-5(4H)-thione, which is promising for drug design, were examined. The UV/Vis spectrum (450-200 nm) of the compound in EtOH was measured. Full geometry optimization using density functional theory (DFT) in the B3LYP/cc-pVDZ approximation allowed the equilibrium configuration of the molecule to be determined and IR and Raman spectra to be calculated. Based on these, the experimental vibrational IR and Raman spectra were interpreted and the biological activity indices were predicted. The UV/Vis spectrum of the title compound was simulated at the time-dependent DFT/CAM-B3LYP/cc-pVDZ level with and without solvent effects and at the ab initio multi-reference perturbation theory XMCQDPT2 level. The UV/Vis spectrum that was simulated using the multi-reference XMCQDPT2 approximation agreed very successfully with the experimental data, in contrast to the single-reference DFT method. This was probably a consequence of intramolecular charge transfer.

Fractionation of yeast extract by nanofiltration process to assess key compounds involved in CHO cell culture improvement.

PubMed

Mosser, Mathilde; Kapel, Romain; Chevalot, Isabelle; Olmos, Eric; Marc, Ivan; Marc, Annie; Oriol, Eric

2015-01-01

Yeast extract (YE) is known to greatly enhance mammalian cell culture performances, but its undefined composition decreases process reliability. Accordingly, in the present study, the nature of YE compounds involved in the improvement of recombinant CHO cell growth and IgG production was investigated. First, the benefits of YE were verified, revealing that it increased maximal concentrations of viable cells and IgG up to 73 and 60%, respectively compared to a reference culture. Then, the analyses of YE composition highlighted the presence of molecules such as amino acids, vitamins, salts, nucleobase, and glucose that were contained in reference medium, while others including peptides, trehalose, polysaccharides, and nucleic acids were not. Consequently, YE was fractionated by a nanofiltration process to deeper evaluate its effects on CHO cell cultures. The YE molecules already contained in reference medium were mainly isolated in the permeate fraction together with trehalose and short peptides, while other molecules were concentrated in the retentate. Permeate, which was free of macromolecules, exhibited a similar positive effect than raw YE on maximal concentrations. Additional studies on cell energetic metabolism underlined that dipeptides and tripeptides in permeate were used as an efficient source of nitrogenous substrates. © 2015 American Institute of Chemical Engineers.

Population genetic structure and tolerance to dioxin-like compounds of a migratory marine fish (Menidia menidia) at polychlorinated biphenyl-contaminated and reference sites.

PubMed

Roark, Shaun A; Kelble, Mary A; Nacci, Diane; Champlin, Denise; Coiro, Laura; Guttman, Sheldon I

2005-03-01

The present study was conducted to evaluate evidence of genetic adaptation to local contaminants in populations of the migratory marine fish Menidia menidia residing seasonally in reference sites or an industrial harbor contaminated with dioxin-like compounds (DLCs). For this purpose, we compared DLC sensitivity and genetic patterns of populations sampled from sites both inside and outside New Bedford Harbor (NBH; MA, USA), a U.S. Environmental Protection Agency Superfund site with extreme polychlorinated biphenyl (PCB) contamination. Offspring of M. menidia collected from NBH were significantly less sensitive regarding embryonic exposure to the dioxin-like PCB congener 3,3',4,4',5-pentachlorobiphenyl (PCB 126) than offspring of M. menidia from a reference site. Analysis of 10 polymorphic enzymatic loci indicated little genetic differentiation among populations in the study area. However, genotype frequencies of juveniles from both NBH and an adjacent site in Massachusetts exhibited significant deviations from Hardy-Weinberg equilibrium expectations at one locus, phosphoglucomutase (PGM*). Genetic analysis of survivors of embryonic laboratory exposure to PCB 126 indicated that genotypes at PGM* were related to survivorship. Although a relationship was identified between DLC tolerance and PGM* genotype, regional mixing of M. menidia populations during migration and absence of multigeneration exposure at contaminated sites may limit localized adaptation.

Spectral Analysis of 3-(Adamantan-1-yl)-4-Ethyl-1-[(4-Phenylpiperazin-1-yl) Methyl]-1H-1,2,4-Triazole-5(4H)-Thione

NASA Astrophysics Data System (ADS)

Mindarava, Y. L.; Shundalau, M. B.; Al-Wahaibi, L. H.; El-Emam, A. A.; Matsukovich, A. S.; Gaponenko, S. V.

2018-05-01

Vibrational IR (3200-650 cm-1) and Raman spectra (3200-150 cm-1) of adamantane-containing 3-(adamantan-1-yl)-4-ethyl-1-[(4-phenylpiperazin-1-yl)methyl]-1H-1,2,4-triazole-5(4H)-thione, which is promising for drug design, were examined. The UV/Vis spectrum (450-200 nm) of the compound in EtOH was measured. Full geometry optimization using density functional theory (DFT) in the B3LYP/cc-pVDZ approximation allowed the equilibrium configuration of the molecule to be determined and IR and Raman spectra to be calculated. Based on these, the experimental vibrational IR and Raman spectra were interpreted and the biological activity indices were predicted. The UV/Vis spectrum of the title compound was simulated at the time-dependent DFT/CAM-B3LYP/cc-pVDZ level with and without solvent effects and at the ab initio multi-reference perturbation theory XMCQDPT2 level. The UV/Vis spectrum that was simulated using the multi-reference XMCQDPT2 approximation agreed very successfully with the experimental data, in contrast to the single-reference DFT method. This was probably a consequence of intramolecular charge transfer.

Vapor pressures of a homologous series of polyethylene glycols as a reference data set for validating vapor pressure measurement techniques.

NASA Astrophysics Data System (ADS)

Krieger, Ulrich; Marcolli, Claudia; Siegrist, Franziska

2015-04-01

The production of secondary organic aerosol (SOA) by gas-to-particle partitioning is generally represented by an equilibrium partitioning model. A key physical parameter which governs gas-particle partitioning is the pure component vapor pressure, which is difficult to measure for low- and semivolatile compounds. For typical atmospheric compounds like e.g. citric acid or tartaric acid, vapor pressures have been reported in the literature which differ by up to six orders of magnitude [Huisman et al., 2013]. Here, we report vapor pressures of a homologous series of polyethylene glycols (triethylene glycol to octaethylene glycol) determined by measuring the evaporation rate of single, levitated aerosol particles in an electrodynamic balance. We propose to use those as a reference data set for validating different vapor pressure measurement techniques. With each addition of a (O-CH2-CH2)-group the vapor pressure is lowered by about one order of magnitude which makes it easy to detect the lower limit of vapor pressures accessible with a particular technique down to a pressure of 10-8 Pa at room temperature. Reference: Huisman, A. J., Krieger, U. K., Zuend, A., Marcolli, C., and Peter, T., Atmos. Chem. Phys., 13, 6647-6662, 2013.

Combined chemical and biotechnological production of 20βOH-NorDHCMT, a long-term metabolite of Oral-Turinabol (DHCMT).

PubMed

Liu, Jiaxin; Chen, Lei; Joseph, Jan Felix; Naß, Alexandra; Stoll, Anna; de la Torre, Xavier; Botrè, Francesco; Wolber, Gerhard; Parr, Maria Kristina; Bureik, Matthias

2018-06-01

Anabolic androgenic steroids (AAS) are misused very frequently in sport competitions as performance enhancing agents. One of the doping compounds that has been detected with increased frequency in the last few years is dehydrochloromethyltestosterone (DHCMT, 4-chloro-17β-hydroxy-17α-methylandrosta-1,4-dien-3-one; brand name Oral Turinabol). The long-term DHCMT metabolite 20βOH-NorDHCMT (4-chloro-17β-hydroxymethyl-17α-methyl-18-norandrosta-1,4,13-trien-3-one) was reported earlier to be detectable in urine samples for more than 22 days after DHCMT administration; however, purified reference material was not available so far. In this study we demonstrate a successful combination of Wagner-Meerwein rearrangement of DHCMT to NorDHCMT (4-chloro-17,17-dimethyl-18-norandrosta-1,4,13-trien-3-one) and subsequent whole-cell biotransformation with a recombinant fission yeast strain expressing the human cytochrome P450 enzyme (CYP or P450) CYP21A2 for the synthesis of mg amounts of this metabolite. It was then used as reference for the analysis of a post administration urine of DHCMT. The availability of this reference compound will provide an incontestable proof for DHCMT abuse. Copyright © 2018 Elsevier Inc. All rights reserved.

Trypanocidal Activity of Quinoxaline 1,4 Di-N-oxide Derivatives as Trypanothione Reductase Inhibitors.

PubMed

Chacón-Vargas, Karla Fabiola; Nogueda-Torres, Benjamin; Sánchez-Torres, Luvia E; Suarez-Contreras, Erick; Villalobos-Rocha, Juan Carlos; Torres-Martinez, Yuridia; Lara-Ramirez, Edgar E; Fiorani, Giulia; Krauth-Siegel, R Luise; Bolognesi, Maria Laura; Monge, Antonio; Rivera, Gildardo

2017-02-01

Chagas disease or American trypanosomiasis is a worldwide public health problem. In this work, we evaluated 26 new propyl and isopropyl quinoxaline-7-carboxylate 1,4-di-N-oxide derivatives as potential trypanocidal agents. Additionally, molecular docking and enzymatic assays on trypanothione reductase (TR) were performed to provide a basis for their potential mechanism of action. Seven compounds showed better trypanocidal activity on epimastigotes than the reference drugs, and only four displayed activity on trypomastigotes; T-085 was the lead compound with an IC50 = 59.9 and 73.02 µM on NINOA and INC-5 strain, respectively. An in silico analysis proposed compound T-085 as a potential TR inhibitor with better affinity than the natural substrate. Enzymatic analysis revealed that T-085 inhibits parasite TR non-competitively. Compound T-085 carries a carbonyl, a CF3, and an isopropyl carboxylate group at 2-, 3- and 7-position, respectively. These results suggest the chemical structure of this compound as a good starting point for the design and synthesis of novel trypanocidal derivatives with higher TR inhibitory potency and lower toxicity.

Penialidins A-C with strong antibacterial activities from Penicillium sp., an endophytic fungus harboring leaves of Garcinia nobilis.

PubMed

Jouda, Jean-Bosco; Kusari, Souvik; Lamshöft, Marc; Mouafo Talontsi, Ferdinand; Douala Meli, Clovis; Wandji, Jean; Spiteller, Michael

2014-10-01

Three new polyketides named penialidins A-C (1-3), along with one known compound, citromycetin (4), were isolated from an endophytic fungus, Penicillium sp., harbored in the leaves of the Cameroonian medicinal plant Garcinia nobilis. Their structures were elucidated by means of spectroscopic and spectrometric methods (NMR and HRMS(n)). The antibacterial efficacies of the new compounds (1-3) were tested against the clinically-important risk group 2 (RG2) bacterial strains of Staphylococcus aureus and Escherichia coli. The ecologically imposing strains of E. coli (RG1), Bacillus subtilis and Acinetobacter sp. BD4 were also included in the assay. Compound 3 exhibited pronounced activity against the clinically-relevant S. aureus as well as against B. subtilis comparable to that of the reference standard (streptomycin). Compound 2 was also highly-active against S. aureus. By comparing the structures of the three new compounds (1-3), it was revealed that altering the substitutions at C-10 and C-2 can significantly increase the antibacterial activity of 1. Copyright © 2014 Elsevier B.V. All rights reserved.

Abietane-Type Diterpenoid Amides with Highly Potent and Selective Activity against Leishmania donovani and Trypanosoma cruzi.

PubMed

Pirttimaa, Minni; Nasereddin, Abedelmajeed; Kopelyanskiy, Dmitry; Kaiser, Marcel; Yli-Kauhaluoma, Jari; Oksman-Caldentey, Kirsi-Marja; Brun, Reto; Jaffe, Charles L; Moreira, Vânia M; Alakurtti, Sami

2016-02-26

Dehydroabietylamine (1) was used as a starting material to synthesize a small library of dehydroabietyl amides by simple and facile methods, and their activities against two disease-causing trypanosomatids, namely, Leishmania donovani and Trypanosoma cruzi, were assayed. The most potent compound, 10, an amide of dehydroabietylamine and acrylic acid, was found to be highly potent against these parasites, displaying an IC50 value of 0.37 μM against L. donovani axenic amastigotes and an outstanding selectivity index of 63. Moreover, compound 10 fully inhibited the growth of intracellular amastigotes in Leishmania donovani-infected human macrophages with a low IC50 value of 0.06 μM. This compound was also highly effective against T. cruzi amastigotes residing in L6 cells with an IC50 value of 0.6 μM and high selectivity index of 58, being 3.5 times more potent than the reference compound benznidazole. The potent activity of this compound and its relatively low cytotoxicity make it attractive for further development in pursuit of better drugs for patients suffering from leishmaniasis and Chagas disease.

HPLC Separation of Vitamin E and Its Oxidation Products and Effects of Oxidized Tocotrienols on the Viability of MCF-7 Breast Cancer Cells in Vitro.

PubMed

Drotleff, Astrid M; Büsing, Anne; Willenberg, Ina; Empl, Michael T; Steinberg, Pablo; Ternes, Waldemar

2015-10-14

Tocotrienols, a vitamin E subgroup, exert potent anticancer effects, but easily degrade due to oxidation. Eight vitamin E reference compounds, α-, β-, γ-, or δ-tocopherols or -tocotrienols, were thermally oxidized in n-hexane. The corresponding predominantly dimeric oxidation products were separated from the parent compounds by diol-modified normal-phase HPLC-UV and characterized by mass spectroscopy. The composition of test compounds, that is, α-tocotrienol, γ-tocotrienol, or palm tocotrienol-rich fraction (TRF), before and after thermal oxidation was determined by HPLC-DAD, and MCF-7 cells were treated with both nonoxidized and oxidized test compounds for 72 h. Whereas all nonoxidized test compounds (0-100 μM) led to dose-dependent decreases in cell viability, equimolar oxidized α-tocotrienol had a weaker effect, and oxidized TRF had no such effect. However, the IC50 value of oxidized γ-tocotrienol was lower (85 μM) than that of nonoxidized γ-tocotrienol (134 μM), thereby suggesting that γ-tocotrienol oxidation products are able to reduce tumor cell viability in vitro.

A molecular topology approach to predicting pesticide pollution of groundwater

USGS Publications Warehouse

Worrall , Fred

2001-01-01

Various models have proposed methods for the discrimination of polluting and nonpolluting compounds on the basis of simple parameters, typically adsorption and degradation constants. However, such attempts are prone to site variability and measurement error to the extent that compounds cannot be reliably classified nor the chemistry of pollution extrapolated from them. Using observations of pesticide occurrence in U.S. groundwater it is possible to show that polluting from nonpolluting compounds can be distinguished purely on the basis of molecular topology. Topological parameters can be derived without measurement error or site-specific variability. A logistic regression model has been developed which explains 97% of the variation in the data, with 86% of the variation being explained by the rule that a compound will be found in groundwater if 6 < 0.55. Where 6χp is the sixth-order molecular path connectivity. One group of compounds cannot be classified by this rule and prediction requires reference to higher order connectivity parameters. The use of molecular approaches for understanding pollution at the molecular level and their application to agrochemical development and risk assessment is discussed.

Effect of ethylenediamine on chemical degradation of insulin aspart in pharmaceutical solutions.

PubMed

Poulsen, Christian; Jacobsen, Dorte; Palm, Lisbeth

2008-11-01

To examine the effect of different amine compounds on the chemical degradation of insulin aspart at pharmaceutical formulation conditions. Insulin aspart preparations containing amine compounds or phosphate (reference) were prepared and the chemical degradation was assessed following storage at 37 degrees C using chromatographic techniques. Ethylenediamine was examined at multiple concentrations and the resulting insulin-ethylenediamine derivates were structurally characterized using matrix assisted laser desorption ionization time-of-flight mass spectroscopy. The effects on ethylenediamine when omitting glycerol or phenolic compounds from the formulations were investigated. Ethylenediamine was superior in terms of reducing formation of high molecular weight protein and insulin aspart related impurities compared to the other amine compounds and phosphate. Monotransamidation of insulin aspart in the presence of ethylenediamine was observed at all of the six possible Asn/Gln residues with Asn(A21) having the highest propensity to react with ethylenediamine. Data from formulations studies suggests a dual mechanism of ethylenediamine and a mandatory presence of phenolic compounds to obtain the effect. The formation of high molecular weight protein and insulin aspart related impurities was reduced by ethylenediamine in a concentration dependant manner.

Bayesian screening for active compounds in high-dimensional chemical spaces combining property descriptors and molecular fingerprints.

PubMed

Vogt, Martin; Bajorath, Jürgen

2008-01-01

Bayesian classifiers are increasingly being used to distinguish active from inactive compounds and search large databases for novel active molecules. We introduce an approach to directly combine the contributions of property descriptors and molecular fingerprints in the search for active compounds that is based on a Bayesian framework. Conventionally, property descriptors and fingerprints are used as alternative features for virtual screening methods. Following the approach introduced here, probability distributions of descriptor values and fingerprint bit settings are calculated for active and database molecules and the divergence between the resulting combined distributions is determined as a measure of biological activity. In test calculations on a large number of compound activity classes, this methodology was found to consistently perform better than similarity searching using fingerprints and multiple reference compounds or Bayesian screening calculations using probability distributions calculated only from property descriptors. These findings demonstrate that there is considerable synergy between different types of property descriptors and fingerprints in recognizing diverse structure-activity relationships, at least in the context of Bayesian modeling.

Preliminary Evaluation of a Turbine/Rotary Combustion Compound Engine for a Subsonic Transport. [fuel consumption and engine tests of turbofan engines

NASA Technical Reports Server (NTRS)

Civinskas, K. C.; Kraft, G. A.

1976-01-01

The fuel consumption of a modern compound engine with that of an advanced high pressure ratio turbofan was compared. The compound engine was derived from a turbofan engine by replacing the combustor with a rotary combustion (RC) engine. A number of boost pressure ratios and compression ratios were examined. Cooling of the RC engine was accomplished by heat exchanging to the fan duct. Performance was estimated with an Otto-cycle for two levels of energy lost to cooling. The effects of added complexity on cost and maintainability were not examined and the comparison was solely in terms of cruise performance and weight. Assuming a 25 percent Otto-cycle cooling loss (representative of current experience), the best compound engine gave a 1.2 percent improvement in cruise. Engine weight increased by 23 percent. For a 10 percent Otto-cycle cooling loss (representing advanced insulation/high temperature materials technology), a compound engine with a boost PR of 10 and a compression ratio of 10 gave an 8.1 percent lower cruise than the reference turbofan.

Synthesis, quantitative structure-property relationship study of novel fluorescence active 2-pyrazolines and application.

PubMed

Girgis, Adel S; Basta, Altaf H; El-Saied, Houssni; Mohamed, Mohamed A; Bedair, Ahmad H; Salim, Ahmad S

2018-03-01

A variety of fluorescence-active fluorinated pyrazolines 13-33 was synthesized in good yields through cyclocondensation reaction of propenones 1-9 with aryl hydrazines 10-12 . Some of the synthesized compounds provided promising fluorescence properties with quantum yield ( Φ ) higher than that of quinine sulfate (standard reference). Quantitative structure-property relationship studies were undertaken supporting the exhibited fluorescence properties and estimating the parameters governing properties. Five synthesized fluorescence-active pyrazolines ( 13 , 15 , 18 , 19 and 23 ) with variable Φ were selected for treating two types of paper sheets (Fabriano and Bible paper). These investigated fluorescence compounds, especially compounds 19 and 23 , provide improvements in strength properties of paper sheets. Based on the observed performance they can be used as markers in security documents.

Synthesis, quantitative structure–property relationship study of novel fluorescence active 2-pyrazolines and application

PubMed Central

Girgis, Adel S.; El-Saied, Houssni; Mohamed, Mohamed A.; Bedair, Ahmad H.; Salim, Ahmad S.

2018-01-01

A variety of fluorescence-active fluorinated pyrazolines 13–33 was synthesized in good yields through cyclocondensation reaction of propenones 1–9 with aryl hydrazines 10–12. Some of the synthesized compounds provided promising fluorescence properties with quantum yield (Φ) higher than that of quinine sulfate (standard reference). Quantitative structure–property relationship studies were undertaken supporting the exhibited fluorescence properties and estimating the parameters governing properties. Five synthesized fluorescence-active pyrazolines (13, 15, 18, 19 and 23) with variable Φ were selected for treating two types of paper sheets (Fabriano and Bible paper). These investigated fluorescence compounds, especially compounds 19 and 23, provide improvements in strength properties of paper sheets. Based on the observed performance they can be used as markers in security documents. PMID:29657796

Synthesis, quantitative structure-property relationship study of novel fluorescence active 2-pyrazolines and application

NASA Astrophysics Data System (ADS)

Girgis, Adel S.; Basta, Altaf H.; El-Saied, Houssni; Mohamed, Mohamed A.; Bedair, Ahmad H.; Salim, Ahmad S.

2018-03-01

A variety of fluorescence-active fluorinated pyrazolines 13-33 was synthesized in good yields through cyclocondensation reaction of propenones 1-9 with aryl hydrazines 10-12. Some of the synthesized compounds provided promising fluorescence properties with quantum yield (Φ) higher than that of quinine sulfate (standard reference). Quantitative structure-property relationship studies were undertaken supporting the exhibited fluorescence properties and estimating the parameters governing properties. Five synthesized fluorescence-active pyrazolines (13, 15, 18, 19 and 23) with variable Φ were selected for treating two types of paper sheets (Fabriano and Bible paper). These investigated fluorescence compounds, especially compounds 19 and 23, provide improvements in strength properties of paper sheets. Based on the observed performance they can be used as markers in security documents.

Novel pyrrolopyrimidines and triazolopyrrolopyrimidines carrying a biologically active sulfonamide moieties as anticancer agents.

PubMed

Ghorab, Mostafa M; Alsaisd, Mansour S; Nissan, Yassin M

2015-01-01

A new series of pyrroles 5, 6, pyrrolopyrimidines 8, 11-14, 16-29, triazolo-pyrrolopyrimidines 9, 10 and 15 carrying a biologically active sulfonamide moities were synthesized using 2-amino-3-cyano-4-(4-bromophenyl)pyrrole 5 as a strategic starting material. The structures of the prepared compounds were confirmed by elemental analyses, IR, 1H-NMR and 13C-NMR data. All of the synthesized compounds showed promising anticancer activity against breast cancer cell line (MCF7) compared to doxorubicin as reference drug, especially compounds 5-17, 21-24 and 28 with better IC50 than that of doxorubicin. In order to suggest the mechanism of action of their cytotoxic activities, molecular docking on the active site of c-Src was done and good results were obtained.

Crystal field effect in light actinide dioxides and oxychalcogenides-a unified phenomenological description

NASA Astrophysics Data System (ADS)

Gajek, Z.

2004-05-01

The electronic properties of the actinide ions in the series of semi-conducting, antiferromagnetic compounds: dioxides, AnO2 and oxychalcogenides, AnOY, where An=U, Np and Y=S, Se, are re-examined from the point of view of the consistency of the crystal field (CF) model. The discussion is based on the supposition that the effective metal-ligand interaction solely determines the net CF effect in non-metallic compounds. The main question we address here is, whether a reliable, consistent description of the CF effect in terms of the intrinsic parameters can be achieved for this particular family of compounds. Encouraging calculations reported previously for the AnO2 and UOY series serve as a reference data in the present estimation of electronic structure parameters for neptunium oxychalcogenides.

Differential nephrotoxicity of cisplatin and a novel series of traditional Chinese medicine-platinum anticancer agents correlates with their chemical reactivity towards sulfur-containing nucleophiles.

PubMed

To, Kenneth K W; Au-Yeung, Steve C F; Ho, Yee-Ping

2006-07-01

A series of novel traditional Chinese medicine-platinum compounds has been found to be active against a number of murine and human cancers both in vitro and in vivo. Their high potency and the lack of cisplatin cross-resistance are believed to be due to the inclusion of the protein phosphatase 2A-inhibiting demethylcantharidin in the novel structures. A simple reversed-phase high-performance liquid chromatographic method was developed and validated as a stability-indicating assay for the platinum compounds. Using cisplatin and carboplatin as reference compounds, the stability study agrees well with the literature-reported findings. The novel traditional Chinese medicine-platinum compounds were more stable than cisplatin in water and dextrose, but became unstable in normal saline, a characteristic similar to that of carboplatin. The developed assay was further applied to study the chemical reactivity of the novel platinum compounds towards physiologically important nucleophiles such as glutathione and cysteine. The novel compounds were considerably less reactive to the sulfur-containing nucleophiles than cisplatin. In-vitro cytotoxicity assay was performed in a porcine kidney LLC-PK1 cell line model to investigate the nephrotoxicity potential of the platinum compounds. The lower rate of hydrolysis and the decreased reactivity of the novel traditional Chinese medicine-platinum compounds towards sulfur-containing bionucleophiles appear to have reduced their toxicity when compared with cisplatin, yet the antitumor activities of the novel compounds have not been compromised.

Preliminary antifungal activity assay of selected chlorine-containing derivatives of xanthone and phenoxyethyl amines.

PubMed

Klesiewicz, Karolina; Żelaszczyk, Dorota; Trojanowska, Danuta; Bogusz, Bożena; Małek, Marianna; Waszkielewicz, Anna; Szkaradek, Natalia; Karczewska, Elżbieta; Marona, Henryk; Budak, Alicja

2018-06-20

The aim of this study was to preliminary evaluate antifungal activity diverse group of chlorine-containing xanthone and phenoxyethyl amine derivatives - and to select most promising compounds for further studies. The antifungal efficacy of 16 compounds was tested with qualitative and quantitative methods against both reference and clinical strains of dermatophytes, moulds and yeasts. The disc-diffusion method has demonstrated that from 16 tested compounds, 7 possess good antifungal activity against dermatophytes and/or moulds while none of them has shown good efficacy against yeasts or bacterial strains. The most active compounds (2, 4, 10, 11, 12, 15, 16) were tested quantitatively by broth dilution method to obtain MIC values. The MIC values against dermatophytes ranged from 8 to 64 μg/mL. Compound 2 was the most active one against dermatophytes (MIC 50 and MIC 90 were 8 μg/mL). The MIC values for moulds ranged from 16 to 256 μg/mL. Compound 4 was the most active one against moulds, with MIC 50 and MIC 90 values amounting to 32 μg/mL. Among the tested compounds, compound 4 (derivative of xanthone) was the most active one and expressed good antifungal efficacy against clinical strains of dermatophytes and moulds. However, another xanthone derivative (compound 2) was the most active and selective against dermatophytes. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Targeting Prostate-Specific Membrane Antigen (PSMA) with F-18-Labeled Compounds: the Influence of Prosthetic Groups on Tumor Uptake and Clearance Profile.

PubMed

Bouvet, Vincent; Wuest, Melinda; Bailey, Justin J; Bergman, Cody; Janzen, Nancy; Valliant, John F; Wuest, Frank

2017-12-01

Prostate-specific membrane antigen (PSMA) is an important biomarker expressed in the majority of prostate cancers. The favorable positron emission tomography (PET) imaging profile of the PSMA imaging agent 2-(3-(1-carboxy-5-[(6-[ 18 F]fluoro-pyridine-3-carbonyl)-amino]-pentyl)-ureido)-pentane-dioic acid [ 18 F]DCFPyL in preclinical prostate cancer models and in prostate cancer patients stimulated the development and validation of other fluorine-containing PSMA inhibitors to further enhance pharmacokinetics and simplify production methods. Here, we describe the synthesis and radiopharmacological evaluation of various F-18-labeled PSMA inhibitors which were prepared through different prosthetic group chemistry strategies. Prosthetic groups N-succinimidyl-4-[ 18 F]fluorobenzoate ([ 18 F]SFB), 4-[ 18 F]fluorobenzaldehyde, and 2-deoxy-2-[ 18 F]fluoro-D-glucose ([ 18 F]FDG) were used for bioconjugation reactions to PSMA-binding lysine-urea-glutamate scaffold via acylation and oxime formation. All fluorine-containing PSMA inhibitors were tested for their PSMA inhibitory potency in an in vitro competitive binding assay in comparison to an established reference compound [ 125 I]TAAG-PSMA. Tumor uptake and clearance profiles of three F-18-labeled PSMA inhibitors ([ 18 F]4, [ 18 F]7, and [ 18 F]8) were studied with dynamic PET imaging using LNCaP tumor-bearing mice. F-18-labeled PSMA inhibitors were synthesized in 32-69 % radiochemical yields using (1) acylation reaction at the primary amino group of the lysine residue with [ 18 F]SFB and (2) oxime formation with 4-[ 18 F]fluorobenzaldehyde and [ 18 F]FDG using the respective aminooxy-functionalized lysine residue. Compound 7 displayed an IC 50 value of 6 nM reflecting very high affinity for PSMA. Compounds 4 and 8 showed IC 50 values of 13 and 62 nM, respectively. The IC 50 value of reference compound DCFPyL was 13 nM. Dynamic PET imaging revealed the following SUV 60min for radiotracer uptake in PSMA(+) LNCaP tumors: 0.98 ([ 18 F]DCFPyL), 2.11 ([ 18 F]7), 0.40 ([ 18 F]4), and 0.19 ([ 18 F]8). The observed tumor uptake and clearance profiles demonstrate the importance of the selected prosthetic group on the pharmacokinetic profile of analyzed PSMA-targeting radiotracers. Radiotracer [ 18 F]7 displayed the highest uptake and retention in LNCaP tumors, which exceeded uptake values of reference compound [ 18 F]DCFPyL by more than 100 %. Despite the higher kidney and liver uptake and retention of compound [ 18 F]7, the simple radiosynthesis and the exceptionally high tumor uptake (SUV 60min 2.11) and retention make radiotracer [ 18 F]7 an interesting alternative to radiotracer [ 18 F]DCFPyL for PET imaging of PSMA in prostate cancer.

Trophic hierarchies revealed via amino acid isotopic analysis

USDA-ARS?s Scientific Manuscript database

Despite the potential of isotopic methods to illuminate trophic function, accurate estimates of lifetime feeding tendencies have remained elusive. A relatively new approach—referred to as compound-specific isotopic analysis (CSIA)—has emerged, centering on the measurement of 15N:14N ratios in amino ...

ORGANIC AEROSOL SAMPLING AND ANALYSIS METHODS RESEARCH

EPA Science Inventory

Carbonaceous material is a major component of ambient PM at all locations in the U.S. and it is composed of two major classes: organic carbon (OC, composed of hundreds of individual compounds) and elemental carbon (EC, also referred to as soot, black carbon, or light adsorbing ca...

Quat co-formulations optimized for use with cotton nonwoven disposable wipes

USDA-ARS?s Scientific Manuscript database

Quaternary ammonium compounds, commonly referred to as quats, are cationic surfactants widely used as the active biocidal ingredient for disposable disinfecting wipes. The cationic nature of quats results in a strong ionic interaction and adsorption onto wipes materials that have an anionic surface...

75 FR 48582 - Approval and Promulgation of Implementation Plans and Operating Permits Program; State of Nebraska

Federal Register 2010, 2011, 2012, 2013, 2014

2010-08-11

... the basis that these compounds make a negligible contribution to tropospheric ozone formation. These... has a negligible contribution to tropospheric ozone formation, and need not be considered in..., Incorporation by reference, Intergovernmental relations, Nitrogen dioxide, Ozone, Particulate matter, Reporting...

Phonological Acquisition in Simultaneous Bilingual Mandarin-English Preschoolers

ERIC Educational Resources Information Center

Liu-Shea, May

2011-01-01

Purpose: Significant challenges face speech-language pathologists when children raised in bilingual environments are referred for speech-language evaluations. The situation is compounded for bilingual Mandarin-English children because no research-based data is available to date. This study is a preliminary examination of phonological acquisition…

COMPARING PCDDS, PCDFS, AND DIOXIN-LIKE PCBS IN FARM-RAISED AND WILD-CAUGHT CATFISH FROM SOUTHERN MISSISSIPPI

EPA Science Inventory

Polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and polychlorinated biphenyls (PCBs) [hereafter referred to as ¿dioxin-like compounds¿] are persistent environmental contaminants that have been found to be ubiquitous in environmental media and bio...

Beam dynamics pre-design with KONUS principle for the DTL of SPPC p-Linac

NASA Astrophysics Data System (ADS)

Liu, Jing; Li, Haipeng; Lu, Yuanrong; Su, Jiancang; Liu, Xiaolong; Fu, Qi

2018-04-01

As the Higgs bosons were observed on the LHC in 2012, a two-stage particle collider program named CEPC-SPPC is proposed for precise measurement of Higgs properties and exploring the new physics models. In order to deliver a 2.1-TeV proton beam into the Super Proton-Proton Collider (SPPC), the injector chain will use a 1.2-GeV proton linac (p-Linac) and three synchrotrons of p-RCS, MSS and SS. This paper focuses on the preliminary conceptual design of the DTL within the p-Linac and mainly concerns about the beam dynamics studies. Taking advantages of the KONUS principle and LORASR code, a 325 MHz, 50.65 MeV DTL design which is composed of three tanks in 15.6 m will be presented. The whole DTL contains 129 gaps for beam acceleration, one quadruple doublet which is behind the buncher and eight quadruple triplets of which three are located after each tank, respectively. The aims of this pre-study are to optimize the acceleration electric field distribution together with the focusing magnetic field parameters, enhance the beam transmission quality of beam envelopes, particle distribution and energy spread, then improve the DTL performance in terms of transmission efficiency and so on. The results of the analyses show that the DTL pre-design achieves 16.8 times high energy gain and meets all the p-Linac requirements well.