Synthesis and Characterization of Perfluoroalkyl Heterocyclic Elastomers

DTIC Science & Technology

Perfluoro -4,9,14,19-tetraoxadocosane diimidate-dihydroxybenzidine polymers have been prepared from carefully purified monomers. DTA measurements show...attained was 0.28. Polymers prepared from dihydroxybenzidine and methyl perfluoro -4,9-dioxadodecanediimidate soften at about 65C. with a Tg near 21C...of 3,3’-diamino-4,4’-dihydroxybenzophenone with methyl perfluorosebacimidate . The polymer softens at 205C., forms films and has excellent thermal

A New Approach to Highly Fluorinated Lubricants.

DTIC Science & Technology

1987-10-30

demonstrated the value of perfluoroalkyl groups being present. 7 In this way, xrious perfluoroethers were characterised, thus demonstrating the...mixture, containing four components (g.l.c. col. A 450C), was separated using preparative scale g.l.c. techniques to give:- perfluoropentane (4%); perfluoro ...CHRFOCHRFCH2 OCHRFCH 3 ) (where RF - CF 2CFHCF3 ) 2. These adducts were then fluorinated by cobalt trifluoride to give corresponding perfluoro -ethers

Synthesis of Perfluorinated Ethers by Solution Phase Direct Fluorination: An Adaptation of the La-Mar Technique

DTIC Science & Technology

1990-08-22

Six of the 3 perfluorinated ethers prepared have been previously synthesized by other methods: perfluoro -5,5-bis(ethoxy- f methyl) -3,7-dioxanonane...from partially fluorinated starting material [34]. Third, as with perfluoroalkanes and simple perfluoroethers , Clark’s experimental results indicated 3...a highly branched perfluoroether ) by direct fluorination 3 in solution. Second, since some of these perfluorinated compounds had been previously

Sex-related differences in the enhancing effects of perfluoro-octanoic acid on stearoyl-CoA desaturase and its influence on the acyl composition of phospholipid in rat liver. Comparison with clofibric acid and tiadenol.

PubMed Central

Kawashima, Y; Uy-Yu, N; Kozuka, H

1989-01-01

The effects of the peroxisome proliferators clofibric acid (p-chlorophenoxyisobutyric acid), tiadenol [2,2'-(decamethylenedithio)diethanol] and perfluoro-octanoic acid (PFOA) on hepatic stearoyl-CoA desaturation in male and female rats were compared. Treatment of male rats with the three peroxisome proliferators increased markedly the activity of stearoyl-CoA desaturase. Administration of clofibric acid or tiadenol to female rats increased greatly the hepatic activity of stearoyl-CoA desaturase, the extent of the increases being slightly less pronounced than those of male rats. In contrast with the other two peroxisome proliferators, however, PFOA did not change the activity of stearoyl-CoA desaturase in female rats. Hormonal manipulations revealed that this sex-related difference in the effect of PFOA on stearoyl-CoA desaturase activity is strongly dependent on testosterone. The increase in stearoyl-CoA desaturase activity by peroxisome proliferators was not accompanied by any notable increases in the microsomal content of cytochrome b5 or the activity of NADH: cytochrome b5 reductase. The administration of the peroxisome proliferators greatly altered the acyl composition of hepatic phosphatidylcholine and phosphatidylethanolamine (namely the proportions of C18:1 and C20:3,n-9 fatty acids increased in both phospholipids), and the alterations were partially associated with the increase in stearoyl-CoA desaturase activity. PMID:2574572

Elemental Fluorine Based Syntheses of Pentafluoro Phenly and other Aromatic Perfluoropolyether Polymers

DTIC Science & Technology

1994-01-31

ECM 300 PA. 13.8 Pe: -1.0 SCALE $000 00 MZ/o• 14.7171 Pe•/CM 50 0 -50 -100 -150 -200 PPM 3 Very unusual perfluoro polyketone structures have beeni...11PIA C14 LI) LL. L)V LLL cim C45 We think the zeolitic solid state structure of this very interesting perfluoro polyketone is most unusual and there

Current and historical concentrations of poly and perfluorinated compounds in sediments of the northern Great Lakes - Superior, Huron, and Michigan.

PubMed

Codling, Garry; Hosseini, Soheil; Corcoran, Margaret B; Bonina, Solidea; Lin, Tian; Li, An; Sturchio, Neil C; Rockne, Karl J; Ji, Kyunghee; Peng, Hui; Giesy, John P

2018-05-01

Current and historical concentrations of 22 poly- and perfluorinated compounds (PFASs) in sediment collected from Lake Superior and northern Lake Michigan in 2011 and Lake Huron in 2012 are reported. The sampling was performed in two ways, Ponar grabs of surface sediments for current spatial distribution across the lake and dated cores for multi-decadal temporal trends. Mean concentrations of the sum of PFASs (∑PFASs) were 1.5, 4.6 and 3.1 ng g -1 dry mas (dm) in surface sediments for Lakes Superior, Michigan and Huron, respectively. Of the five Laurentian Lakes, the watersheds of Superior and Huron are the less densely populated by humans, and concentrations observed were typically less and from more diffuse sources, due to lesser urbanization and industrialization. However, some regions of greater concentrations were observed and might indicate more local, point sources. In core samples concentrations ranged from 7 that include perfluoro-n-octane sulfonate (PFOS) bind more strongly to sediment, which resulted in more accurate analyses of temporal trends. Shorter-chain PFASs, such as perfluoro-n-butanoic acid which is the primary replacement for C8 PFASs that have been phased out, are more soluble and were identified in some core layers at depths corresponding to pre-production periods. Thus, analyses of temporal trends of these more soluble compounds in cores of sediments were less accurate. Total elemental fluorine (TF) and extractable organic fluorine (EOF) indicated that identified PFASs were not a significant fraction of fluorine containing compounds in sediment (<0.01% in EOF). Copyright © 2018 Elsevier Ltd. All rights reserved.

The Toxicity of Perfluoro-N-Decanoic Acid and 2,3,7,8- Tetrachlorodibenzo-P-Dioxin in L5178Y Mouse Lymphoma Cells

DTIC Science & Technology

1983-03-01

ABSTRACT (Continue on reverse side If necessary and identify by block number) Perfluoro -n-decanoic acid ( PFDA ) causes toxic sequelae in vivo very similar to...acid analogs. All polyfluorinated acids tested (either perfluorinated or w-hydro-analogs) with chain length 9 or greater caused impairment of clone...of 5 to 7. The acute and subchronic toxicity of ammonium perfluoro -n-octanoate ( PFOA ) has been described in detail in both rats and rhesus monkeys

Anaerobic biodegradability and methanogenic toxicity of key constituents in copper chemical mechanical planarization effluents of the semiconductor industry.

PubMed

Hollingsworth, Jeremy; Sierra-Alvarez, Reyes; Zhou, Michael; Ogden, Kimberly L; Field, Jim A

2005-06-01

Copper chemical mechanical planarization (CMP) effluents can account for 30-40% of the water discharge in semiconductor manufacturing. CMP effluents contain high concentrations of soluble copper and a complex mixture of organic constituents. The aim of this study is to perform a preliminary assessment of the treatability of CMP effluents in anaerobic sulfidogenic bioreactors inoculated with anaerobic granular sludge by testing individual compounds expected in the CMP effluents. Of all the compounds tested (copper (II), benzotriazoles, polyethylene glycol (M(n) 300), polyethylene glycol (M(n) 860) monooleate, perfluoro-1-octane sulfonate, citric acid, oxalic acid and isopropanol) only copper was found to be inhibitory to methanogenic activity at the concentrations tested. Most of the organic compounds tested were biodegradable with the exception of perfluoro-1-octane sulfonate and benzotriazoles under sulfate reducing conditions and with the exception of the same compounds as well as Triton X-100 under methanogenic conditions. The susceptibility of key components in CMP effluents to anaerobic biodegradation combined with their low microbial inhibition suggest that CMP effluents should be amenable to biological treatment in sulfate reducing bioreactors.

Role of Dispersive Fluorous Interaction in the Solvation Dynamics of the Perfluoro Group Containing Molecules.

PubMed

Mondal, Saptarsi; Chaterjee, Soumit; Halder, Ritaban; Jana, Biman; Singh, Prashant Chandra

2017-08-17

Perfluoro group containing molecules possess an important self-aggregation property through the fluorous (F···F) interaction which makes them useful for diverse applications such as medicinal chemistry, separation techniques, polymer technology, and biology. In this article, we have investigated the solvation dynamics of coumarin-153 (C153) and coumarin-6H (C6H) in ethanol (ETH), 2-fluoroethanol (MFE), and 2,2,2-trifluoroethanol (TFE) using the femtosecond upconversion technique and molecular dynamics (MD) simulation to understand the role of fluorous interaction between the solute and solvent molecules in the solvation dynamics of perfluoro group containing molecules. The femtosecond upconversion data show that the time scales of solvation dynamics of C6H in ETH, MFE, and TFE are approximately the same whereas the solvation dynamics of C153 in TFE is slow as compared to that of ETH and MFE. It has also been observed that the time scale of solvation dynamics of C6H in ETH and MFE is higher than that of C153 in the same solvents. MD simulation results show a qualitative agreement with the experimental data in terms of the time scale of the slow components of the solvation for all the systems. The experimental and simulation studies combined lead to the conclusion that the solvation dynamics of C6H in all solvents as well as C153 in ETH and MFE is mostly governed by the charge distribution of ester moieties (C═O and O) of dye molecules whereas the solvation of C153 in TFE is predominantly due to the dispersive fluorous interaction (F···F) between the perfluoro groups of the C153 and solvent molecules.

Hepatic Metabolism of Perfluorinated Carboxylic Acids: A Nuclear Magnetic Resonance Investigation

DTIC Science & Technology

1990-12-14

perfluoro -n- octanoic acid ( PFOA ) and perfluoro -n-decanoic acid ( PFDA ) In the rat. Spectra obtained at various times following the administration of PFOA ...used to monitor the metabolic fate of perfluoro -n-octanoic acid ( PFOA ) and perfluoro -n-decanoic acid ( PFDA ) in the rat. Spectra obtained at various...specifically Investigate the metabolic effects caused by perfluoro -n-octanoic acid ( PFOA ) and perfluoro -n-decanoic acid ( PFDA ) in rats.

40 CFR Appendix A to Subpart G of... - Substitutes Subject to Use Restrictions and Unacceptable Substitutes

Code of Federal Regulations, 2010 CFR

2010-07-01

... Substitute Decision Comments Electronics cleaning w/CFC-113, MCF Perfluoro-carbons (C5F12, C6F12, C6F14... date); as of January 1, 1996, for uses in existing equipment. Electronics cleaning w/CFC-113 HCFC 141b... listings for CFC-113 past the effective date of the prohibition. Electronics cleaning w/MCF HCFC 141b and...

Superhydrophobic, Hybrid, Electrospun Cellulose Acetate Nanofibrous Mats for Oil/Water Separation by Tailored Surface Modification.

PubMed

Arslan, Osman; Aytac, Zeynep; Uyar, Tamer

2016-08-03

Electrospun cellulose acetate nanofibers (CA-NF) have been modified with perfluoro alkoxysilanes (FS/CA-NF) for tailoring their chemical and physical features aiming oil-water separation purposes. Strikingly, hybrid FS/CA-NF showed that perfluoro groups are rigidly positioned on the outer surface of the nanofibers providing superhydrophobic characteristic with a water contact angle of ∼155°. Detailed analysis showed that hydrolysis/condensation reactions led to the modification of the acetylated β(1 → 4) linked d-glucose chains of CA transforming it into a superhydrophobic nanofibrous mat. Analytical data have revealed that CA-NF surfaces can be selectively controlled for fabricating the durable, robust and water resistant hybrid electrospun nanofibrous mat. The -OH groups available on the CA structure allowed the basic sol-gel reactions started by the reactive FS hybrid precursor system which can be monitored by spectroscopic analysis. Since alkoxysilane groups on the perfluoro silane compound are capable of reacting for condensation together with the CA, superhydrophobic nanofibrous mat is obtained via electrospinning. This structural modification led to the facile fabrication of the novel oil/water nanofibrous separator which functions effectively demonstrated by hexane/oil and water separation experiments. Perfluoro groups consequently modified the hydrophilic CA nanofibers into superhydrophobic character and therefore FS/CA-NF could be quite practical for future applications like water/oil separators, as well as self-cleaning or water resistant nanofibrous structures.

Design and chemical synthesis of iodine-containing molecules for application to solar-pumped I* lasers

NASA Technical Reports Server (NTRS)

Shiner, C. S.

1986-01-01

The design and chemical synthesis of new media for solar pumped iodine molecule lasers are explored. In an effort to prepare an iodo fluorocarbon compound absorbing strongly at 300 nm or above, the synthesis of perfluoro allylic iodides was investigated. These compounds furnish especially stable allylic radicals upon photodissociation. The desired red shift is anticipated in the absorption maximum could correlate with increasing radical stability. This expectation was based upon the analysis, previously reported, of the structures and absorption maxima of compounds studied earlier. A previously unknown substance was prepared, a prototypical target molecule, perfluoro-3-iodocyclopent-1-ene. It was obtained by reaction of perfluorocyclopentene with sulfur trioxide under the influence of antimony pentafluoride catalyst, followed by treatment of the resulting allylic fluorosulfonate with sodium iodide in sulfoland solvent. Preliminary data indicate that the absorption maximum for the iodo fluorocarbon is not shifted significantly to longer wavelength. It is not certain whether this result reflects an unexpected influence of the cyclic structure upon the position of the absorption maximum.

Purification and thermal analysis of perfluoro-n-alkanoic acids.

PubMed

Tsuji, Minami; Inoue, Tohru; Shibata, Osamu

2008-01-15

Purification of perfluoro-n-alkanoic acids (C(n)F(2n+1)COOH, n=7, 9, 11, 13, 15 and 17) was made by repeated recrystallizations from n-hexane/acetone mixed solvent, and their purity was found to be more than 99.5% by GC-MS, NMR, and elemental analysis. The thermal behaviors such as melting point and enthalpy change of fusion were investigated using differential scanning calorimetry (DSC). The melting point monotonously increased with increasing carbon number (n) of the acids, while the enthalpy change showed irregularity at n=14. The crystal structure of these acids was found to be dependent upon solvent used for recrystallization; that is, the acids recrystallized from the above solvent becomes more stable energetically, indicating their higher enthalpy change of fusion than that of the solidified acids from fused ones. The solid state was also found to vary depending upon the thermal history, indicating that a few crystal structures of the solid state are quite similar energetically. The melting points (T(m)) of perfluoro-n-alkanoic acids are higher than those of corresponding n-alkanoic acids, and the difference in T(m) increases with increasing carbon number in the acids.

PROCESS FOR PURIFYING CRUDE PERFLUOROCARBONS

DOEpatents

Holeton, R.E.

1959-03-24

A method is described for refining organic perfluoro compounds. In the manufacture of perfluorinated compounds by the fluorination of hydrocarbons, the product frequently is contaminated ny incompletely fluorimated hydrogen containing impurities. These impurities can be removed by contacting the products in a fluid conditions with an active adsorbents such as silica gel or alumina gel. The patent claims are restricted to this refining of crude perfluorinated lubricating oil.

Hexafluorobenzene in comparison with perfluoro-15-crown-5-ether for repeated monitoring of oxygenation using 19F MRI in a mouse model.

PubMed

Mignion, Lionel; Magat, Julie; Schakman, Olivier; Marbaix, Etienne; Gallez, Bernard; Jordan, Bénédicte F

2013-01-01

Hexafluorobenzene (HFB) and perfluoro-15-crown-5-ether (15C5) were compared as fluorine reporter probes of tissue oxygenation using (19)F MRI for dynamic assessment of muscle oxygenation, with special focus on muscle tissue toxicity of the probes, and consecutive alteration of animal behavior. The latter were also compared in terms of sensitivity to changes in oxygenation as well as of signal-to-noise ratio for accurate pO(2) measurements. For that purpose, mouse muscles were imaged at 11.7 T, at 2- and 36-h after intramuscular injection of HFB or 15C5. Histological analysis of the muscle tissue revealed a lack of toxicity for 15C5 from 2 up to 36-h postinjection, whereas HFB induced tissue necrosis, blood clots and thrombosis as soon as 24-h postinjection. This muscle toxicity led to a limitation in mice mobility 24-h after injection of HFB as evidenced by behavioral testing (open-field, grip strength, and catwalk tests), which was not the case after 15C5 intramuscular injection. Finally, pO(2) measurements assessed 2-h postinjection showed consistent values with both probes, evidencing cross-validation of the (19)F MRI oximetry technique for acute measurements. However, the measurement at 36-h was hampered for HFB, which showed significant lower values of muscle pO(2), whereas 15C5 was able to reliably assess muscle pO(2) at 36-h postinjection. Copyright © 2012 Wiley Periodicals, Inc.

Determination of the thermal stability of fluids by tensimetry - Instrumentation and procedure

NASA Technical Reports Server (NTRS)

Helmick, Larry S.; Jones, William R., Jr.

1990-01-01

A computerized tensimeter and experimental procedure for determination of the thermal decomposition temperature (T sub d) of perfluoro alkylethers were developed and tested. Both the apparatus and the procedure are described in detail. Results of testing with bis(2-ethylhexyl) phthalate and trimethylolpropane triheptanoate demonstrate that the reciprocal of the decomposition temperature is a linear function of the logarithm of the gas volume/heated liquid volume ratio. The T sub d obtained for each compound at a gas volume/heated liquid volume ration of one was similar to the value previously reported using an isoteniscope technique. Results of testing with a polymer of hexafluoropropylene oxide demonstrate that this instrument and procedure can be used to determine the T sub d of perfluoro alkylethers.

Exchange Reactions of Organotin and Organosilicon Compounds with Mild Fluorinating Agents

DTIC Science & Technology

1992-03-01

methylphosphonic difluoride, boron trifluoride etherate, and perfluoroisobutene all react with both organosilicon and organotin. alkoxides to give...inlet tube, was charged with tributyltin cyanide (53.30 gm, 0.1686 mol) in a dry glove bag under an inert atmosphere and 500 ml of dry xylene was then...Chem. Vol. 29, p 471 (1985). 6. Tyuleneva, V.V., Rozov, L.A., Zeifman, Yu.V. and I. L. Knuny- ants,"Exchange of Fluorine by Chlorine in Perfluoro-isobutene," Tzv.Akad.Nauk. SSSR. Ser. Khim No. 5, p 1136 (1975). 17

Identification of a Pathway for Perfluorocompounds to Human Diet from Application of Biosolids to Agricultural Fields

EPA Science Inventory

Perfluoro compounds are ubiquitous contaminants in human blood. The pathways which result in near universal exposure to humans in modern societies are not clearly understood. Sources to environmental compartments and transport between compartments are only poorly studies, and thi...

Design and investigation of de Vries liquid crystals based on 5-phenyl-pyrimidine and (R,R)-2,3-epoxyhexoxy backbone

NASA Astrophysics Data System (ADS)

Sreenilayam, S. P.; Rodriguez-Lojo, D.; Panov, V. P.; Swaminathan, V.; Vij, J. K.; Panarin, Yu. P.; Gorecka, E.; Panov, A.; Stevenson, P. J.

2017-10-01

Calamitic liquid crystals based on 5-phenyl-pyrimidine derivatives have been designed, synthesized, and characterized. The 5-phenyl pyrimidine core was functionalized with a chiral (R,R)-2,3-epoxyhexoxy chain on one side and either siloxane or perfluoro terminated chains on the opposite side. The one involving a perfluorinated chain shows Sm A* phase over a wide temperature range of 82 °C, whereas the siloxane analog exhibits both Sm A* and Sm C* phases over a broad range of temperatures, and a weak first-order Sm A*-Sm C* transition is observed. For the siloxane analog, the reduction factor for the layer shrinkage R (relative to its thickness at the Sm A*-Sm C* transition temperature, TAC) is ˜0.373 , and layer shrinkage is 1.7% at a temperature of 13 °C below the TAC. This compound is considered to have "de Vries smectic" characteristics with the de Vries coefficient CdeVries of ˜0.86 on the scale of zero (maximum-layer shrinkage) to 1 (zero-layer shrinkage). A three-parameter mean-field model is introduced for the orientational distribution function (ODF) to reproduce the electro-optic properties. This model explains the experimental results and leads to the ODF, which exhibits a crossover from the sugar-loaf to diffuse-cone ODF some 3 °C above TAC.

The production and verification of pristine semi-fluorinated thiol monolayers on gold.

PubMed

Ford, Kym; Battersby, Bronwyn J; Wood, Barry J; Gentle, Ian R

2012-03-15

The presence of adventitious contamination of self-assembled monolayers (SAMs) is a well-known phenomenon that is often overlooked or underestimated in the literature. Herein, we demonstrate that it is possible to produce pristine self-assembled monolayers (SAMs) on gold surfaces that are devoid of adventitious species. The chemical purity or the pristine quality of the SAM was verified by the experimental relative atomic ratios measured by X-ray photoelectron spectroscopy (XPS) of all elements including carbon and corresponded to within 5% of the stoichiometric ratios. Perfluoro-octyl-thiolate (F8) was used as a model compound in this study, where monolayers were assembled from solutions of an acetylated F8 precursor. Quantitative elemental characterization of the acetylated F8 precursor by cold-stage XPS provided valuable reference data for the analysis of the subsequent SAMs. Comprehensive analysis of high-resolution XPS C 1s spectra proved to be essential for establishing the purity of the SAMs, since the peaks of the adventitious species were easily distinguished from those of the F8. Analyses of deliberately contaminated F8 SAMs showed that the adventitious species persisted during the process of self-assembly and therefore co-existed with the SAM in the interfacial region. The work also established that even a lengthy deposition time of 18 h was incapable of displacing the adventitious species present at the interface. Copyright © 2011 Elsevier Inc. All rights reserved.

Genotoxicity Assessment of Perfluorodecanoic Acid Using a Battery of In Vitro and In Vivo/in Vitro Assays.

DTIC Science & Technology

1990-12-01

Maximum 200 words) Perfluoro -n-decanoic acid ( PFDA ), a perfluorinated fatty acid was evaluated in in vitro bioassays to assess its potential...PolychlorotrifluoroethyleneDU.TBL PFDA Perfluoro -n-decanoic acid PFOA Perfluoro -n-octanoic acid ..... RI Replicative index rpm Revolutions per minute By...an increase in the amount of S-phase DNA synthesis. The perfluorinated carboxylic acid, perfluoro -n-decanoic acid ( PFDA ), has previously been shown to

New approach for assessing human perfluoroalkyl exposure via hair.

PubMed

Alves, Andreia; Jacobs, Griet; Vanermen, Guido; Covaci, Adrian; Voorspoels, Stefan

2015-11-01

In the recent years hair has been increasingly used as alternative matrix in human biomonitoring (HBM) of environmental pollutants. Sampling advantages and time integration of exposure assessment seems the most attractive features of hair matrix. In the current study, a novel miniaturized method was developed and validated for measuring 15 perfluoroalkyl substances (PFAS), including perfluoro n-butanoic acid (PFBA), perfluoro n-pentanoic acid (PFPeA), perfluoro n-hexanoic acid (PFHxA), perfluoro n-heptanoic acid (PFHpA), perfluor n-octanoic acid (PFOA), perfluoro n-nonanoic acid (PFNA), perfluoro tetradecanoic acid (PFTeDA), perfluorobutane sulfonic acid (PFBS), perfluoro pentane sulfonic acid (PFPeS), perfluorohexane sulfonic acid (PFHxS), perfluoroheptane sulfonic acid (PFHpS), perfluorooctane sulfonic acid (PFOS), perfluorononane sulfonic acid (PFNS), perfluorodecane sulfonic acid (PFDS) and perfluorododecane sulfonic acid (PFDoS) in human hair by liquid chromatography tandem mass spectrometry (LC-MS/MS). After extraction using ethyl acetate, dispersive ENVI-Carb was used for clean-up. Good intra- and inter-day precision for low (LQ 5 ng/g hair) and high spike (HQ 15n g/g) levels were achieved (in general RSD <10%). The accuracy was assessed using recoveries (%), which ranged between 68-118% (LQ) and 70-121% (HQ). The instrumental limit of detection (LODi) and limit of quantification (LOQi) were between 1-4 pg/g hair and 3-13 pg/g hair, respectively. The method limit of quantification (LOQm) ranged between 6 and 301 pg/g hair. The PFAS levels were measured in 30 human hair samples indicating that the levels are low (14-1534 pg/g hair). Some PFAS were not present in any hair sample (e.g. PFHpA, PFTeDA, PFNA, PFPeS, PFHpS, PFOS and PFNS), while other PFAS were frequently detected (PFBA, PFPeA, PFHxA, PFOA, PFBS, PFHxS, PFOS, PFDS and PFDoS) in human hair. Although levels in general were low, there is evidence of higher human exposure to some analytes, such as PFBA, PFPeA, PFHxA, PFOA, PFBS, PFHxS, and PFDoS. The current study shows that hair is a suitable alternative non-invasive matrix for exposure assessment of PFAS. Copyright © 2015 Elsevier B.V. All rights reserved.

Perfluorinated substance assessment in sediments of a large-scale reservoir in Danjiangkou, China.

PubMed

He, Xiaomin; Li, Aimin; Wang, Shengyao; Chen, Hao; Yang, Zixin

2018-01-07

The occurrence of eight perfluorinated compounds (PFCs) in the surface sediments from 10 sampling sites spread across the Danjiangkou Reservoir was investigated by isotope dilution ultra-high-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) after solid-phase extraction (SPE). All the sediments from the 10 sites contained detectable levels of PFCs. The total concentration of the target PFCs in each sediment sample (C ∑PFCs ) ranged from 0.270 to 0.395 ng g -1 of dry weight, and the mean value of C ∑PFCs was 0.324 ± 0.045 ng g -1 of dry weight for the whole reservoir. For each perfluorinated compound in one sediment, perfluorooctane sulfonate (PFOS) or perfluoro-n-butanoic acid (PFBA) consistently had a higher concentration than the other six PFCs, while perfluoro-n-octanoic acid (PFOA) was always undetectable. In terms of spatial distribution, the total and individual concentrations of PFCs in sediment from downstream sites of the Danjiangkou Reservoir were higher than those from upstream sites. Factor analysis revealed that PFCs in the sediment samples originated from electroplating and anti-fog agents in industry, food/pharmaceutical packaging and the water/oil repellent paper coating, and the deposition process. The quotient method was utilized to assess the ecological risk of PFCs in the sediments of the Danjiangkou Reservoir, which showed that the concentrations of PFCs were not considered a risk. In this study, detailed information on the concentration level and distribution of PFCs in the sediments of the Danjiangkou Reservoir, which is the source of water for the Middle Route Project of the South-to-North Water Transfer Scheme in China, was reported and analyzed for the first time. These results can provide valuable information for water resource management and pollution control in the Danjiangkou Reservoir.

Effects of Nonadecafluorodecanoic Acid on Tissue Fatty Acids of the Rat.

DTIC Science & Technology

1982-01-01

REVIEW Perfluorinated compounds have wide application. Perfluorocarboxylic and perfluorosulfonic acids have found commercial utilization in plating...readily obtainable in crystalline form. 1 Perfluorocarboxylic and perfluorosulfonic acids are used commercially in plating systems and as wetting agents...are generally considered to be metaboli- cally inert, but perfluorohexane causes reduction of microsomal cyto- chrome P-450 in vitro and perfluoro -n

Design and chemical synthesis of iodine-containing molecules for application to solar-pumped I* lasers

NASA Technical Reports Server (NTRS)

Shiner, C. S.

1985-01-01

This work is directed toward the design and chemical synthesis of new media for solar-pumped I* lasers. In view of the desirability of preparing a perfluoroalkyl iodide absorbing strongly at 300 nm, the relationship betwen perfluoroalkyl iodide structure and the corresponding absorption wavelength was reexamined. Analysis of existing data suggests that, in this family of compounds, the absorption maximum shifts to longer wavelength, as desired, as the C-I bond in the lasant is progressively weakened. Weakening of the C-I bond correlates, in turn, with increasing stability of the perfluoroalkyl radical formed upon photodissociation of the iodide. The extremely promising absorption characteristics of perfluoro-tert-butyl iodide can be accounted for on this basis. A new technique of diode laser probing to obtain precise yields of I* atoms in photodissociation was also developed.

Perfluoro anion based binary and ternary ionic liquids as electrolytes for dye-sensitized solar cells

NASA Astrophysics Data System (ADS)

Lin, Hsi-Hsin; Peng, Jia-De; Suryanarayanan, V.; Velayutham, D.; Ho, Kuo-Chuan

2016-04-01

In this work, eight new ionic liquids (ILs) based on triethylammonium (TEA) or n-methylpiperidinium (NMP) cations and perfluoro carboxylate (PFC) anions having different carbon chain lengths are synthesized and their physico-chemical properties such as density, decomposition temperature, viscosity and conductivity are determined. Photovoltaic characteristics of dye-sensitized solar cells (DSSCs) with binary ionic liquids electrolytes, containing the mixture of the synthesized ILs and 1-methyl-3-propyl imidazolium iodide (PMII) (v/v = 35/65), are evaluated. Among the different ILs, solar cells containing NMP based ILs show higher VOC than that of TEA, whereas, higher JSC is noted for the DSSCs incorporated with the latter when compared to the former. Further, the photo-current of the DSSCs decreases with the increase of the carbon chain length of perfluoro carboxylate anionic group of ILs. The cell performance of the DSSC containing ternary ionic liquids-based electrolytes compose of NMP-2C/TEA-2C/PMII (v/v/v = 28/7/65) exhibits a JSC of 12.99 mA cm-2, a VOC of 639.0 mV, a FF of 0.72, and a cell efficiency of 6.01%. The extraordinary durability of the DSSC containing the above combination of electrolytes stored in dark at 50 °C is proved to be unfailing up to 1200 h.

Spatial and temporal trends in poly- and per-fluorinated compounds in the Laurentian Great Lakes Erie, Ontario and St. Clair.

PubMed

Codling, Garry; Sturchio, Neil C; Rockne, Karl J; Li, An; Peng, H; Tse, Timothy J; Jones, Paul D; Giesy, John P

2018-06-01

The temporal and spatial trends in sediment of 22 poly- and perfluorinated (PFAS) compounds were investigated in the southern Great Lakes Erie and Ontario as well as Lake St. Clair. Surface concentrations measured by Ponar grab samples indicated a trend for greater concentrations near to urban sites. Mean concentrations ∑ 22 PFAS were 15.6, 18.2 and 19 ng g -1 dm for Lakes St. Clair, Erie and Ontario, respectively. Perfluoro-n-butanoic acid (PFBA) and Perfluoro-n-hexanoic acid (PFHxA) were frequently determined in surface sediment and upper core samples indicating a shift in use patterns. Where PFBA was identified it was at relatively great concentrations typically >10 ng g -1 dm. However as PFBA and PFHxA are less likely to bind to sediment they may be indicative of pore water concentrations Sedimentation rates between Lake Erie and Lake Ontario differ greatly with greater rates observed in Lake Erie. In Lake Ontario, in general concentrations of PFAS observed in core samples closely follow the increase in use along with an observable change due to regulation implementation in the 1970s for water protection. However some of the more water soluble PFAS were observed in deeper core layers than the time of production could account for, indicating potential diffusion within the sediment. Given the greater sedimentation rates in Lake Erie, it was hoped to observe in greater resolution changes since the mid-1990s. However, though some decrease was observed at some locations the results are not clear. Many cores in Lake Erie had clearly observable gas voids, indicative of gas ebullition activity due to biogenic production, there were also observable mussel beds that could indicate mixing by bioturbation of core layers. Copyright © 2018 Elsevier Ltd. All rights reserved.

Diffusion of dioxygen in 1-alkenes and biphenyl in perfluoro- n-alkanes

NASA Astrophysics Data System (ADS)

Kowert, Bruce A.; Sobush, Kurtis T.; Dang, Nhan C.; Seele, Louis G., III; Fuqua, Chantel F.; Mapes, Courtney L.

2002-02-01

The translational diffusion constant, D, has been measured for O 2 in the even 1-alkenes 1-C 6H 12 to 1-C 16H 32 and biphenyl in n-C 6F 14 and n-C 9F 20. Deviations from the Stokes-Einstein relation were found; the use of D/ T= A/ ηp gave p=0.560±0.017 for O 2 in the 1-alkenes, the same (within experimental error) as found previously for O 2 in the n-alkanes. The charge transfer (CT) transition used to detect O 2 in the 1-alkenes is at 220 nm. The D values for biphenyl in the perfluoro- n-alkanes (PFAs) are consistent with those in the n-alkanes, where p=0.718±0.004. These results suggest that O 2 has similar solute-solvent interactions in both the 1-alkenes and n-alkanes as does biphenyl in the n-alkanes and PFAs.

Performance measurements of C{sub 1}-C{sub 3} carbonyl compounds using DNPH-coated silica gel and C{sub 18} cartridges

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

Kleindienst, T.E.; Corse, E.W.; Blanchard, F.T.

1994-12-31

Measurements have been conducted to examine the performance of formaldehyde, acetaldehyde, and acetone using silica and C{sub 18} cartridges coated with 2,4-dinitrophenylhydrazine. Laboratory measurements for formaldehyde were conducted using a paraformaldehyde generator to produce reproducible and constant concentrations of the compound. For acetaldehyde and acetone, known concentrations were generated in Teflon chambers. The compounds were routed into a sampling manifold where simultaneous measurements could be made with multiple cartridges. Typical concentrations employed in the study were as follows. HCHO: 0.5--25 ppbv; CH{sub 3}CHO; 0.5--10 ppbv; CH{sub 3}C(O)CH{sub 3}: 0.5--10 ppbv. Additional measurements were conducted for these compounds in the presencemore » of potentially interfering compounds such as ozone and water vapor. Serial cartridge collections were periodically used to investigate breakthrough of the carbonyl compounds.« less

Mass Spectra of Some Perfluoroalkyl and Perfluoroalkylether Substituted 1,2,4-Oxadiazoles

NASA Technical Reports Server (NTRS)

Paciorek, Kazimiera J. L.; Nakahara, James H.; Kratzer, Reinhold H.; Rosser, Robert W.

1977-01-01

Electron impact fragmentation patterns were obtained for 1,4-bis[(5-perfluoro-n-heptyl)-1,2,4-oxadiazolyl- benzene, its perfluoroalkylether substituted analogue, 3,5-bis(perfluoroalkyl)-, 3,5-bis(perfluoroalkylether)- and 3-perfluoroalkylether-5-perfluoroalkyl-1,2,4-oxadiazoles. In the compounds containing the phenylene group the molecular ion constituted the base peak; the main process was the breakdown of the oxadiazole ring with concurrent liberation of the perfluoroalkyl or perfluoroalkylether nitrile molecule; cleavage of the fluorinated chain ot to the oxadiazole ring was found to take place to a considerable degree. In the perfluorinated 1,2,4-oxadiazoles cleavage beta to the oxadiazole ring occurred preferentially; fragmentation of the ring itself took place to a limited degree only. The 3-perfluoroalkylether-5-perfluoroalkyl-1,2,4-oxadiazole appeared to undergo the primary beta-cleavage exclusively at the perfluoroalkylether sidechain.

Durable Fluorocarbon-Based Coatings for Aircraft

DTIC Science & Technology

2000-11-01

synthesized two novel monomers, 2-fluoro-2- perfluorooctyl - 1,3-propanediol and 2-fluoro-2- perfluoro (2-ethylhexyl)-1,3-propanediol, and demonstrated that...propanediols, two branched perfluoroalkyl methanols, perfluoro -1H,1H-2-ethylhexanol (pefluoro-1-ethylpentyl methanol) and perfluoro - 1H,1H-2,2...malonates. Reduction of the perfluorinated malonates gave the perfluoroalkyl -branched 1,3-propanediols. R-OH + HBr R-Br cat. O O OCH 2CH3 OCH 2CH3 + O O

Mechanisms of Cellular Membrane Effects of TCDD, Selected Perfluorinated Acids and Polyhalogenated Aromatic Hydrocarbons

DTIC Science & Technology

1985-02-01

toxic response of both cell lines after treatment with the perfluorinated acids ( perfluoro -n-octanoic acid, 9-H hexadecafluoro-n-nonanoic acid, and...throughout the experiments to eliminate the effect of serum on toxicity. The results for perfluoro -n-octanoic acid ( PFOA ) in both cell lines are presented in...the TK+/+ cells but not in the TK+/- cells. The results for the perfluoro -n-decanoic acid ( PFDA ) are presented in Table 3. A dose-response reldtionship

An ultra-sensitive method for the analysis of perfluorinated alkyl acids in drinking water using a column switching high-performance liquid chromatography tandem mass spectrometry.

PubMed

Dasu, Kavitha; Nakayama, Shoji F; Yoshikane, Mitsuha; Mills, Marc A; Wright, J Michael; Ehrlich, Shelley

2017-04-21

In epidemiological research, it has become increasingly important to assess subjects' exposure to different classes of chemicals in multiple environmental media. It is a common practice to aliquot limited volumes of samples into smaller quantities for specific trace level chemical analyses. A novel method was developed for the determination of 14 perfluorinated alkyl acids (PFAAs) in small volumes (10mL) of drinking water using off-line solid phase extraction (SPE) pre-treatment followed by on-line pre-concentration on a WAX column before analysis on column-switching high performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS). In general, large volumes (100-1000mL) have been used for the analysis of PFAAs in drinking water. The current method requires approximately 10mL of drinking water concentrated by using an SPE cartridge and eluted with methanol. A large volume injection of the extract was introduced on to a column-switching HPLC-MS/MS using a mix-mode SPE column for the trace level analysis of PFAAs in water. The recoveries for most of the analytes in the fortified laboratory blanks ranged from 73±14% to 128±5%. The lowest concentration minimum reporting levels (LCMRL) for the 14 PFAAs ranged from 0.59 to 3.4ng/L. The optimized method was applied to a pilot-scale analysis of a subset of drinking water samples from an epidemiological study. These samples were collected directly from the taps in the households of Ohio and Northern Kentucky, United States and the sources of drinking water samples are both surface water and ground water, and supplied by different water distribution facilities. Only five PFAAs, perfluoro-1-butanesulfonic acid (PFBS), perfluoro-1- -hexanesulfonic acid (PFHxS), perfluoro-1-octanesulfonic acid (PFOS), perfluoro-n-heptanoic acid (PFHpA) and perfluoro-n-octanoic acid (PFOA) are detected above the LCMRL values. The median concentrations of these five PFAAs detected in the samples was ≤4.1ng/L with PFOS at 7.6ng/L and PFOA at 10ng/L. Concentrations of perfluoro-1-decanesulfonic acid, PFDS and other perfluoroalkyl carboxylic acids were below the LCMRL values. Copyright © 2017 Elsevier B.V. All rights reserved.

Phase behaviour and conductivity of supporting electrolytes in supercritical difluoromethane and 1,1-difluoroethane.

PubMed

Han, Xue; Ke, Jie; Suleiman, Norhidayah; Levason, William; Pugh, David; Zhang, Wenjian; Reid, Gillian; Licence, Peter; George, Michael W

2016-06-07

We present investigations into a variety of supporting electrolytes and supercritical fluids probing the phase and conductivity behaviour of these systems and show that they not only provide sufficient electrical conductivity for an electrodeposition bath, but match the requirements imposed by the different precursors and process parameters, e.g. increased temperature, for potential deposition experiments. The two supercritical fluids that have been explored in this study are difluoromethane (CH2F2) and 1,1-difluoroethane (CHF2CH3). For CH2F2, the phase behaviour and electrical conductivity of eight ionic compounds have been studied. Each compound consists of a cation and an anion from the selected candidates i.e. tetramethylammonium ([N(CH3)4](+)), tetrabutylammonium ([N((n)C4H9)4](+)), 1-ethyl-3-methylimidazolium ([EMIM](+)) and 1-butyl-3-methylimidazolium ([BMIM](+)) for cations, and tetrakis(perfluoro-tert-butoxy)aluminate ([Al(OC(CF3)3)4](-)), chloride (Cl(-)), trifluoromethyl sulfonimide ([NTf2](-)) and tris(pentafluoroethyl)trifluorophosphate ([FAP](-)) for anions. For CHF2CH3, [N((n)C4H9)4][BF4] and [N((n)C4H9)4][B{3,5-C6H3(CF3)2}4] have been investigated for comparison with the previously measured solubility and conductivity in CH2F2. We have found that [N((n)C4H9)4][Al(OC(CF3)3)4], [N((n)C4H9)4][FAP] and [N(CH3)4][FAP] have much higher molar conductivity in scCH2F2 at similar conditions than [N((n)C4H9)4][BF4], a widely used commercial electrolyte. Additionally, scCHF2CH3 shows potential for use as the solvent for supercritical fluid electrodeposition, especially at high temperatures since high density of this fluid can be achieved at lower operating pressures than similar fluids that can be used to produce electrochemical baths with comparable conductivity.

The Molecular Anatomy of PFDA Hepatotoxicity as Studied by Two-Dimensional Electrophoresis

DTIC Science & Technology

1993-02-26

indicators of cell injury and dysfunction. The compound chosen initially, perfluoro -n-decanoic acid ( PFDA ), is a ten carbon straight-chain perfluorinated ...following: 2mg, 20mg or 50mg PFDA /kg body weight; single injection; animals sacrificed on day 8 of exposure 150mg PFOA /kg ( perfluorooctanoate , PFDA’s...from the following treatments: (I) control; (II) 50mg/kg PFDA ; (III) 100mg/kg PFOA ; and (IV) 400mg/kg clofibrate. Panels V and VI are nitrocellulose

Polymerization of perfluorobutadiene at near-ambient conditions

NASA Technical Reports Server (NTRS)

Toy, M. S.

1971-01-01

Peroxide catalyst under mild conditions initiates homopolymerization of perfluoro butadiene to new linear perfluoro polyenes and vulcanizable fluoro elastomers. Resulting polyperfluoro butadiene serves as hard elastomer for good chemical resistance, as intermediate in graft polymerizations, and as crosslink for high molecular weight materials.

PERFLUOROPHOSPHONIC ACID ACTIVATES PEROXISOME PROUFERATOR-ACTIVATED RECEPTOR-ALPHA BUT NOT CONSTITUTIVE ANDROSTANE RECEPTOR IN THE MURINE LIVER

EPA Science Inventory

Masurf FS-780 is a commercial perfluoro-chemical mixture that contains C612-perfluoroalkylphosphonic acid (PFPA) derivatives. PFPAs have received recent attention as a previously under recognized subclass of perfluoroalkyl acids (PFAAs) that are found in the environment. The curr...

Synthesis of 18,19-dihydroxycorticosterone.

PubMed

Harnik, M; Carmely, S; Cojocaru, M; Kashman, Y

1986-01-01

A four-step synthesis of 18,19-dihydroxycorticosterone 5c, starting with 19,21-dihydroxy-3,20-dioxopregn-5-ene-18,11 beta-lactone-di-(ethylene ketal) 2, is presented. Reduction of 2 with sodium aluminum bis-(methoxyethoxy)hydride gave 11 beta,18,19,21-tetrahydroxy-pregn-5-ene-3,20-dione-di-(ethylene ketal) 3a. Acetylation furnished the corresponding 18,19,21-triacetate 3b, which on treatment with a mixture of perchloric and acetic acids gave 18,19-dihydroxycorticosterone 18,19,21-triacetate 4b. Mild saponification yielded the title compound which, on the basis of ir and nmr spectra, exists as one C-20 isomer of the hemiacetal structure 5c. Periodate oxidation of 5c gave the expected 11 beta, 19-dihydroxy-3-oxoandrost-4-ene-17 beta, 18-carbolactone 6b.

Synthesis of three novel fluorine-18 labeled analogues of L-deprenyl for positron emission tomography (PET) studies of monoamine oxidase B (MAO-B).

PubMed

Nag, Sangram; Lehmann, Lutz; Heinrich, Tobias; Thiele, Andrea; Kettschau, Georg; Nakao, Ryuji; Gulyás, Balázs; Halldin, Christer

2011-10-27

The aim in this project was to synthesize and to study fluorine-18 labeled analogues of l-deprenyl which bind selectively to the enzyme monoamine oxidase B (MAO-B). Three fluorinated l-deprenyl analogues have been generated in multistep organic syntheses. The most promising fluorine-18 compound N-[(2S)-1-[(18)F]fluoro-3-phenylpropan-2-yl]-N-methylprop-2-yn-1-amine (4c) was synthesized by a one-step fluorine-18 nucleophilic substitution reaction. Autoradiography on human brain tissue sections demonstrated specific binding for compound 4c to brain regions known to have a high content of MAO-B. In addition, the corresponding nonradioactive fluorine-19 compound (13) inhibited recombinant human MAO-B with an IC(50) of 170.5 ± 29 nM but did not inhibit recombinant human MAO-A (IC(50) > 2000 nM), demonstrating its specificity. Biodistribution of 4c in mice showed high initial brain uptake leveling at 5.2 ± 0.04%ID/g after 2 min post injection. In conclusion, compound 4c is a specific inhibitor of MAO-B with high initial brain uptake in mice and is, therefore, a candidate for further investigation in PET.

Fluorination of silicone rubber by plasma polymerization

NASA Astrophysics Data System (ADS)

Fielding, Jennifer Chase

Plasma polymerized fluorocarbon (PPFC) films were deposited onto various silicone rubber substrates, including O-rings, to decrease oil uptake. Depositions were performed using a radio frequency (rf)-powered plasma reactor and various fluorocarbon monomers, such as C2F6, C2F 5H, C3F6, and 1H,1H,2H-perfluoro-1-dodecene. PPFC films which were most promising for inhibiting oil uptake were deposited with 1H,1H,2H-perfluoro-1-dodecene, and were composed predominantly of perfluoromethylene (CF2) species. These films displayed low critical surface energies (as low as 2.7 mJ/m2), and high contact angles with oil (84°), which were correlated with the amount of CF2 species present in the film. For the films with the highest degree of CF2 (up to 67%), CF2 chains may have been oriented slightly perpendicular to the substrate and terminated by CF3 species. Adhesion of the PPFC films directly to silicone rubber was found to be poor. However, when a plasma polymerized hydrocarbon interlayer was deposited on the silicone rubber prior to the fluorocarbon films, adhesion was excellent. O-rings coated with multilayer fluorocarbon films showed 2.6% oil uptake after soaking in oil for 100 hrs at 100°C. Due to variability in data, and the low quality of the industrial grade silicone rubber, the oil uptake mechanism was determined to be from oil flowing through flaws in the film due to defects within the substrate, not from generalized diffusion through the film. This mechanism was confirmed using higher quality silicone rubber, which showed little or no oil diffusion. Therefore, this film may perform well as an oil-repelling barrier when deposited on a high quality silicone rubber.

An atmospheric pressure chemical ionization study of the positive and negative ion chemistry of the hydrofluorocarbons 1,1-difluoroethane (HFC-152a) and 1,1,1,2-tetrafluoroethane (HFC-134a) and of perfluoro-n-hexane (FC-72) in air plasma at atmospheric pressure.

PubMed

Marotta, Ester; Paradisi, Cristina; Scorrano, Gianfranco

2004-07-01

A report is given on the ionization/dissociation behavior of the title compounds within air plasmas produced by electrical corona discharges at atmospheric pressure: both positive and negative ions were investigated at different temperatures using atmospheric pressure chemical ionization mass spectrometry (APCI-MS). CHF(2)CH(3) (HFC-152a) undergoes efficient ionic oxidation to C(2)H(5)O(+), in which the oxygen comes from water present in the plasma. In contrast, CF(3)CH(2)F (HFC-134a) does not produce any characteristic positive ion under APCI conditions, its presence within the plasma being revealed only as a neutral ligand in ion-molecule complexes with ions of the background (H(3)O(+) and NO(+)). Analogously, the perfluorocarbon FC-72 (n-C(6)F(14)) does not produce significant positive ions at 30 degrees C: at high temperature, however, it undergoes dissociative ionization to form many product ions including C(3)F(6)(+), C(2)F(4)(+), C(n)F(2n+1)(+) and a few families of oxygen containing cations (C(n)F(2n+1)OH(2)(+), C(n)F(2n)OH(+), C(n)F(2n-1)O(+), C(n)F(2n-1)O(2)H(2)(+), C(n)F(2n-2)O(2)H(+)) which are suggested to derive from C(n)F(2n+1)(+) in a cascade of steps initiated by condensation with water followed by steps of HF elimination and H(2)O addition. Negative ions formed from the fluoroethanes CHF(2)CH(3) and CF(3)CH(2)F (M) include complexes with ions of the background, O(2)(-)(M), O(3)(-)(M) and some higher complexes involving also water, and complexes of the fluoride ion, F(-)(H(2)O), F(-)(M) and higher complexes with both M and H(2)O also together. The interesting product O(2)(-)(HF) is also formed from 1,1-difluoroethane. In contrast to the HFCs, perfluoro-n-hexane gives stable molecular anions, M(-), which at low source temperature or in humidified air are also detected as hydrates, M(-)(H(2)O). In addition, in humidified air F(-)(H(2)O)(n) complexes are also formed. The reactions leading to all major positive and negative product ions are discussed also with reference to available thermochemical data and relevant literature reports. The effects on both positive and negative APCI spectra due to ion activation via increasing V(cone) are also reported and discussed: several interesting endothermic processes are observed under these conditions. The results provide important information on the role of ionic reactions in non-thermal plasma processes.

Identification and characterization of conservative organic tracers for use as hydrologic tracers for the Yucca Mountain site characterization study. Final report

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

Stetzenbach, K.; Farnham, I.

1996-06-01

Extensive tracer testing is expected to take place at the C-well complex in the Nevada Test Site as part of the Yucca Mountain Site Characterization Project. The C-well complex consists of one pumping well, C3, and two injection wells, C1 and C2 into which tracer will be introduced. The goal of this research was to provide USGS with numerous tracers to completed these tests. Several classes of fluorinated organic acids have been evaluated. These include numerous isomers of fluorinated benzoic acids, cinnamic acids, and salicylic acids. Also several derivatives of 2-hydroxy nicotinic acid (pyridone) have been tested. The stability ofmore » these compounds was determined using batch and column tests. Ames testing (mutagenicity/carcinogenicity) was conducted on the fluorinated benzoic acids and a literature review of toxicity of the fluorobenzoates and three perfluoro aliphatic acids was prepared. Solubilities were measured and method development work was performed to optimize the detection of these compounds. A Quality Assurance (QA) Program was developed under existing DOE and USGS guidelines. The program includes QA procedures and technical standard operating procedures. A tracer test, using sodium iodide, was performed at the C-well complex. HRC chemists performed analyses on site, to provide real time data for the USGS hydrologists and in the laboratories at UNLV. Over 2,500 analyses were performed. This report provides the results of the laboratory experiments and literature reviews used to evaluate the potential tracers and reports on the results of the iodide C-well tracer test.« less

Toward Highly Potent Cancer Agents by Modulating the C-2 Group of the Arylthioindole Class of Tubulin Polymerization Inhibitors

PubMed Central

La Regina, Giuseppe; Bai, Ruoli; Rensen, Whilelmina Maria; Di Cesare, Erica; Coluccia, Antonio; Piscitelli, Francesco; Famiglini, Valeria; Reggio, Alessia; Nalli, Marianna; Pelliccia, Sveva; Pozzo, Eleonora Da; Costa, Barbara; Granata, Ilaria; Porta, Amalia; Maresca, Bruno; Soriani, Alessandra; Iannitto, Maria Luisa; Santoni, Angela; Li, Junjie; Cona, Marlein Miranda; Chen, Feng; Ni, Yicheng; Brancale, Andrea; Dondio, Giulio; Vultaggio, Stefania; Varasi, Mario; Mercurio, Ciro; Martini, Claudia; Hamel, Ernest; Lavia, Patrizia; Novellino, Ettore; Silvestri, Romano

2013-01-01

New arylthioindole derivatives having different cyclic substituents at position 2 of the indole were synthesized as anticancer agents. Several compounds inhibited tubulin polymerization at submicromolar concentration and inhibited cell growth at low nanomolar concentrations. Compounds 18 and 57 were superior to the previously synthesized 5. Compound 18 was exceptionally potent as an inhibitor of cell growth: it showed IC50 = 1.0 nM in MCF-7 cells, and it was uniformly active in the whole panel of cancer cells and superior to colchicine and combretastatin A-4. Compounds 18, 20, 55, and 57 were notably more potent than vinorelbine, vinblastine, and paclitaxel in the NCI/ADR-RES and Messa/Dx5 cell lines, which overexpress P-glycoprotein. Compounds 18 and 57 showed initial vascular disrupting effects in a tumor model of liver rhabdomyosarcomas at 15 mg/kg intravenous dosage. Derivative 18 showed water solubility and higher metabolic stability than 5 in human liver microsomes. PMID:23214452

Experience with synthetic fluorinated fluid lubricants

NASA Technical Reports Server (NTRS)

Conley, Peter L.; Bohner, John J.

1990-01-01

Since the late 1970's, the wet lubricant of choice for space mechanisms has been one of the family of synthetic perfluoro polyalkylether (PFPE) compounds, namely Fomblin Z-25 (Bray-815Z) or DuPont's Krytox 143xx series. While offering the advantages of extremely low vapor pressures and wide temperature ranges, these oils and derived greases have a complex chemistry compared to the more familiar natural and synthetic hydrocarbons. Many aerospace companies have conducted test programs to characterize the behavior of these compounds in a space environment, resulting in a large body of hard knowledge as well as considerable space lore concerning the suitability of the lubricants for particular applications and techniques for successful application. The facts are summarized and a few myths about the compounds are dispelled, and some performance guidelines for the mechanism design engineer are provided.

Experimental and Calculational Studies of the Interactions of BF3 with Fluoroethers

NASA Technical Reports Server (NTRS)

Zehe, Michael J.; Morales, Wilfredo; Ball, David W.

1998-01-01

BF3 was co-condensed with (C2H5)2O, (CF3CH2)2O and (C2F5)2O in excess argon at 15 K. Infrared spectra of the matrices showed a definite Lewis acid-base interaction between BF3 and diethyl ether; a weak but definite interaction with bis(2,2,2,-trifluorodiethyl)ether, and no observable interaction with perfluorodiethyl ether. Molecular orbital (MO) calculations complemented the experimental observations by revealing that fluorine atoms on the ethers decreased electron localization about the oxygen atom. Thus, the experimental data and MO calculations indicated a clear trend between strength of interaction with BF3 and the degree of ether F substitution. The implications of the results for commercial perfluoro ether lubricant/metal oxide surface interactions are discussed.

Toxicology of Perfluorodecanoic Acid

DTIC Science & Technology

1990-11-01

Perfluorodecanoic Acid ( PFOA ) and Thyroid Status. A. Statement of Problem: 1. Toxic doses of PFDA result in reduction of feed intake, body weight, serum...hypophagia and body weight loss). ii. Perfluoroaecanoic Acid ( PFOA ) and Lipid Metabolism in the Rat. A. Statement of Problem: 1. PFDA in a dose... perfluorinated acids are not available commercially. B. Objectives: 1. To synthesize perfluoro -n-decanoic acid ( PFDA ) with 14C-labeling in the C-I position. 2. To

Overloaded elution band profiles of ionizable compounds in reversed-phase liquid chromatography: Influence of the competition between the neutral and the ionic species

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

Gritti, Fabrice; Guiochon, Georges A

2008-01-01

The parameters that affect the shape of the band profiles of acido-basic compounds under moderately overloaded conditions (sample size less than 500 nmol for a conventional column) in RPLC are discussed. Only analytes that have a single pK{sub a} are considered. In the buffer mobile phase used for their elution, their dissociation may, under certain conditions, cause a significant pH perturbation during the passage of the band. Two consecutive injections (3.3 and 10 {micro}L) of each one of three sample solutions (0.5, 5, and 50 mM) of ten compounds were injected on five C{sub 18}-bonded packing materials, including the 5more » {micro}m Xterra-C{sub 18} (121 {angstrom}), 5 {micro}m Gemini-C{sub 18} (110 {angstrom}), 5 {micro}m Luna-C{sub 18}(2) (93 {angstrom}), 3.5 {micro}m Extend-C{sub 18} (80 {angstrom}), and 2.7 {micro}m Halo-C{sub 18} (90 {angstrom}). The mobile phase was an aqueous solution of methanol buffered at a constant {sub W}{sup W}pH of 6, with a phosphate buffer. The total concentration of the phosphate groups was constant at 50 mM. The methanol concentration was adjusted to keep all the retention factors between 1 and 10. The compounds injected were phenol, caffeine, 3-phenyl 1-propanol, 2-phenyl butyric acid, amphetamine, aniline, benzylamine, p-toluidine, procainamidium chloride, and propranololium chloride. Depending on the relative values of the analyte pK{sub a} and the buffer solution pH, these analytes elute as the neutral, the cationic, or the anionic species. The influence of structural parameters such as the charge, the size, and the hydrophobicity of the analytes on the shape of its overloaded band profile is discussed. Simple but general rules predict these shapes. An original adsorption model is proposed that accounts for the unusual peak shapes observed when the analyte is partially dissociated in the buffer solution during its elution.« less

Synthesis and Characterization of Perfluoroalkyl Heterocyclic Elastomers

DTIC Science & Technology

Perfluoroalkyl bibenzoxazole polymers containing a (CF2)8 between heterocyclic rings have been prepared by the reaction of dihydroxybenzidine and...methyl perfluorosebacimidate . Through preparation of this polymer, the basic polymerization system has been significantly improved and polymers with...C. (TGA). Copolymers of dihydroxybenzidine and methyl perfluoro -4,9,14,19- tetraoxadocosanediimidate, which are tacky and resilient, have been

Sol-gel niobia sorbent with a positively charged octadecyl ligand providing enhanced enrichment of nucleotides and organophosphorus pesticides in capillary microextraction for online HPLC analysis.

PubMed

Kesani, Sheshanka; Malik, Abdul

2018-04-01

A niobia-based sol-gel organic-inorganic hybrid sorbent carrying a positively charged C 18 ligand (Nb 2 O 5 -C 18 (+ve)) was synthesized to achieve enhanced enrichment capability in capillary microextraction of organophosphorus compounds (which include organophosphorus pesticides and nucleotides) before their online analysis by high-performance liquid chromatography. The sorbent was designed to simultaneously provide three different types of molecular level interactions: electrostatic, Lewis acid-base, and van der Waals interactions. To understand relative contributions of various molecular level analyte-sorbent interactions in the extraction process, two other sol-gel niobia sorbents were also created: (a) a purely inorganic sol-gel niobia sorbent (Nb 2 O 5 ) and (b) an organic-inorganic hybrid sol-gel niobia sorbent carrying an electrically neutral-bonded octadecyl ligand (Nb 2 O 5 -C 18 ). The extraction efficiency of the created sol-gel niobia sorbent (Nb 2 O 5 -C 18 (+ve)) was compared with that of analogously designed and synthesized titania-based sol-gel sorbent (TiO 2 -C 18 (+ve)), taking into consideration that titania-based sorbents present state-of-the-art extraction media for organophosphorus compounds. In capillary microextraction with high-performance liquid chromatography analysis, Nb 2 O 5 -C 18 (+ve) had shown 40-50% higher specific extraction values (a measure of extraction efficiency) over that of TiO 2 -C 18 (+ve). Compared to TiO 2 -C 18 (+ve), Nb 2 O 5 -C 18 (+ve) also provided superior analyte desorption efficiency (96 vs. 90%) during the online release of the extracted organophosphorus pesticides from the sorbent coating in the capillary microextraction capillary to the chromatographic column using reversed-phase high-performance liquid chromatography mobile phase. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Synthesis and fungicidal activity of novel 2,5-disubstituted-1,3,4- thiadiazole derivatives containing 5-phenyl-2-furan

NASA Astrophysics Data System (ADS)

Cui, Zi-Ning; Li, Ya-Sheng; Hu, De-Kun; Tian, Hao; Jiang, Jia-Zhen; Wang, Yuan; Yan, Xiao-Jing

2016-01-01

A series of 2,5-disubstituted-1,3,4-thiadiazoles were synthesized using Lawesson’s reagent by an efficient approach under microwave irradiation in good yields. Their structures were characterized by MS, IR, 1H NMR, 13C NMR, and elemental analysis. Their in vitro and in vivo fungicidal activities revealed that the title compounds exhibited considerable activity against five selected fungi, especially to Phytophthora infestans. In order to illustrate the mechanism of title compounds against P. infestans, scanning electron micrographs (SEM) and transmission electron micrographs (TEM) were applied. The morphological and ultrastructural studies demonstrated that compound I18 led to swelling of hyphae, thickening and proliferating multilayer cell walls, excessive septation and accumulation of dense bodies. The bioassay results indicated compound I18 might act on cell wall biosynthesis, and blocked the nutrition transportation and led to cells senescence and death. Meanwhile, compound I18 had broad fungicidal activity against other twenty different kinds of fungi. These results suggested that title compounds were eligible to be development candidates and compound I18 as a promising lead compound was worthy to be further discovery, especially against P. infestans.

Asymmetric 1,2-perfluoroalkyl migration: easy access to enantioenriched α-hydroxy-α-perfluoroalkyl esters.

PubMed

Wang, Pan; Feng, Liang-Wen; Wang, Lijia; Li, Jun-Fang; Liao, Saihu; Tang, Yong

2015-04-15

This study has led to the development of a novel, highly efficient, 1,2-perfluoro-alkyl/-aryl migration process in reactions of hydrate of 1-perfluoro-alkyl/-aryl-1,2-diketones with alcohols, which are promoted by a Zn(II)/bisoxazoline and form α-perfluoro-alkyl/-aryl-substituted α-hydroxy esters. With (-)-8-phenylmenthol as the alcohol, the corresponding menthol esters are generated in high yields with excellent levels of diastereoselectivity. The mechanistic studies show that the benzilic ester-type rearrangement reaction takes place via an unusual 1,2-migration of electron-deficient trifluoromethyl group rather than the phenyl group. The overall process serves as a novel, efficient, and simple approach for the synthesis of highly enantioenriched, biologically relevant α-hydroxy-α-perfluoroalkyl carboxylic acid derivatives.

New stable perfluoroallyl radical from perfluoro-2,4-dimethyl-3-ethylpentene-2 and its photoconversion reactions

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

Shvedova, M.K.; Allayarov, S.R.; Barkalov, I.M.

1988-05-01

The thermally and chemically stable perfluoroally radical is formed in the radiolysis of perfluoro-2, 4-dimethyl-3-ethylpentene-2. A phototransformation of this radical into other radicals takes place under the action of UV light (/lambda/ < 300 nm) which are thermally unstable. Samples containing up to 90% FMP and 10% of its isomers were placed into ampules made of quartz or SK-4B glass, which gave to EPR signal after irradiation; the ampules were evacuated to a pressure of 0.13 Pa, frozen to 77 K, and irradiated with /sup 60/Co /lambda/-quanta at 77 K with doses up to 200 kGy. Irradiation with UV lightmore » was performed at 77 K with light from a DRSh-1000 lamp.« less

Sorption of structurally different ionized pharmaceutical and illicit drugs to a mixed-mode coated microsampler.

PubMed

Peltenburg, Hester; Timmer, Niels; Bosman, Ingrid J; Hermens, Joop L M; Droge, Steven T J

2016-05-20

The mixed-mode (C18/strong cation exchange-SCX) solid-phase microextraction (SPME) fiber has recently been shown to have increased sensitivity for ionic compounds compared to more conventional sampler coatings such as polyacrylate and polydimethylsiloxane (PDMS). However, data for structurally diverse compounds to this (prototype) sampler coating are too limited to define its structural limitations. We determined C18/SCX fiber partitioning coefficients of nineteen cationic structures without hydrogen bonding capacity besides the charged group, stretching over a wide hydrophobicity range (including amphetamine, amitriptyline, promazine, chlorpromazine, triflupromazine, difenzoquat), and eight basic pharmaceutical and illicit drugs (pKa>8.86) with additional hydrogen bonding moieties (MDMA, atenolol, alprenolol, metoprolol, morphine, nicotine, tramadol, verapamil). In addition, sorption data for three neutral benzodiazepines (diazepam, temazepam, and oxazepam) and the anionic NSAID diclofenac were collected to determine the efficiency to sample non-basic drugs. All tested compounds showed nonlinear isotherms above 1mmol/L coating, and linear isotherms below 1mmol/L. The affinity for C18/SCX-SPME for tested organic cations without Hbond capacities increased with longer alkyl chains, ranging from logarithmic fiber-water distribution coefficients (log Dfw) of 1.8 (benzylamine) to 5.8 (triflupromazine). Amines smaller than benzylamine may thus have limited detection levels, while cationic surfactants with alkyl chain lengths >12 carbon atoms may sorb too strong to the C18/SCX sampler which hampers calibration of the fiber-water relationship in the linear range. The log Dfw for these simple cation structures closely correlates with the octanol-water partition coefficient of the neutral form (Kow,N), and decreases with increased branching and presence of multiple aromatic rings. Oxygen moieties in organic cations decreased the affinity for C18/SCX-SPME. Log Dfw values of neutral benzodiazepines were an order of magnitude higher than their log Kow,N. Results for anionic diclofenac species (logKow,N 4.5, pKa 4.0, log Dfw 2.9) indicate that the C18-SCX fiber might also be useful for sampling of organic anions. This data supports our theory that C18-based coatings are able to sorb ionized compounds through adsorption and demonstrates the applicability of C18-based SPME in the measurement of freely dissolved concentrations of a wide range of ionizable compounds. Copyright © 2016 Elsevier B.V. All rights reserved.

Synthesis of a stationary phase based on silica modified with branched octadecyl groups by Michael addition and photoinduced thiol-yne click chemistry for the separation of basic compounds.

PubMed

Huang, Guang; Ou, Junjie; Wang, Hongwei; Ji, Yongsheng; Wan, Hao; Zhang, Zhang; Peng, Xiaojun; Zou, Hanfa

2016-04-01

A novel silica-based stationary phase with branched octadecyl groups was prepared by the sequential employment of the Michael addition reaction and photoinduced thiol-yne click chemistry with 3-aminopropyl-functionalized silica microspheres as the initial material. The resulting stationary phase denoted as SiO2 -N(C18)4 was characterized by elemental analysis, FTIR spectroscopy and Raman spectroscopy, demonstrating the existence of branched octadecyl groups in silica microspheres. The separations of benzene homologous compounds, acid compounds and amine analogues were conducted, demonstrating mixed-mode separation mechanism on SiO2 -N(C18)4 . Baseline separation of basic drugs mixture was acquired with the mobile phase of acetonitrile/H2 O (5%, v/v). SiO2 -N(C18)4 was further applied to separate Corydalis yanhusuo Wang water extracts, and more baseline separation peaks were obtained for SiO2 -N(C18)4 than those on Atlantis dC18 column. It can be expected that this new silica-based stationary phase will exhibit great potential in the analysis of basic compounds. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Catalytic pyrolysis of wheat bran for hydrocarbons production in the presence of zeolites and noble-metals by using TGA-FTIR method.

PubMed

Lazdovica, K; Liepina, L; Kampars, V

2016-05-01

Pyrolysis of wheat bran with or without catalysts was investigated using TGA-FTIR method in order to determine the influence of zeolite and noble metal catalysts on the evolution profile and relative yield of the volatile compounds. The addition of all catalysts decreased the volatile matter of wheat bran from 76.3% to 75.9%, 73.9%, 73.5%, 69.7% and increased the solid residue from 18.0% to 18.4%, 20.4%, 20.8%, 24.6% under the catalyst of ZSM-5, 5% Pd/C, MCM-41, and 5% Pt/C. Noble-metal catalysts had higher activity for deoxygenation of compounds containing carbonyl, carboxyl, and hydroxyl groups than zeolites. Degradation of nitrogen containing compounds atom proceeded better in presence of zeolites. Noble-metal catalysts promoted formation of aromatics and changed the profiles of evolved compounds whereas zeolites advanced formation of aliphatics and olefins. Copyright © 2016 Elsevier Ltd. All rights reserved.

Three new enantiomerically pure ferrocenylphosphole compounds.

PubMed

López Cortés, José Guadalupe; Vincendeau, Sandrine; Daran, Jean Claude; Manoury, Eric; Gouygou, Maryse

2006-05-01

The absolute configurations of three new enantiomerically pure ferrocenylphosphole compounds, namely (2S,4S,S(Fc))-4-methoxymethyl-2-[2-(9-thioxo-9lambda5-phosphafluoren-9-yl)ferrocenyl]-1,3-dioxane, [Fe(C5H5)(C23H22O3PS)], (III), (S(Fc))-[2-(9-thioxo-9lambda5-phosphafluoren-9-yl)ferrocenyl]methanol, [Fe(C5H5)(C18H14OPS)], (V), and (S(Fc))-diphenyl[2-(9-thioxo-9lambda5-phosphafluoren-9-yl]ferrocenylmethyl]phosphine, [Fe(C5H5)(C30H23P2)], (VIII), have been unambiguously established. All three ligands contain a planar chiral ferrocene group, bearing a dibenzophosphole and either a dioxane, a methanol or a diphenylphosphinomethane group on the same cyclopentadienyl. In compound (V), the occurrence of O-H...S and C-H...S hydrogen bonds results in the formation of a two-dimensional network parallel to (001). The geometry of the ferrocene frameworks agrees with related reported structures.

Aerobic Biodegradation of Trichloroethylene.

DTIC Science & Technology

1987-07-01

into C02 and unidentified nonvolatile products. Phenol, 41 toiin- andq- cresol were found to replace the site water requirement for TCE metabolism...identified as phenol. Other aromatic compounds that could support TCE degradation were toluene, o- cresol , and m- cresol . The degradation could be...Production...... .. .. .. . 17 4. Test for the Catechol Ortho °Ring-Fission Pathway . 18 5. Oxidation of Aromatic Compounds ............. .18 6

Cellular Effects of Perfluorinated Fatty Acids.

DTIC Science & Technology

1985-01-01

perfluoro -n-de canoic acid ( PFDA ), fluoresce e -- I j ~recovery after photobleaching (FRAPB), cell culture ~ . 19. ABSTRACT (Continue an reverse if...necessmzejj dctiy by block number) --Tecompoubd perfluor i--ecan’oic’ acid ( PFDA ) was exposed to three tissue culturer cell lines, PTK2 (kidney),/BRL (buffalo...all cell systems. In particular, previous in vivo and in vitro studies on the similarities of the toxic effects of perfluoro -n-decanoic acid ( PFDA ) and

Permeation Testing of Materials With Chemical Agents or Simulants (Swatch Testing)

DTIC Science & Technology

2013-08-05

through a protective clothing material on a molecular level. Permeation involves the following: (1) sorption of molecules of the chemical into the...de Nemours and Company, Wilmington, Delaware), Teflon perfluoro- alkoxy ( PFA ), and Teflon polytetrafluoroethylene (PTFE). c. In all cases, only...pamphlet PCM positive control material PFA perfluoroalkoxy pH negative ion activity POL petroleum, oil, and lubricants PQL program quantification

Thyroid and Biochemical/Metabolic Effects of PFDA (Perfluoro-n-decanoic Acid).

DTIC Science & Technology

1988-01-04

could be explained by a chemically induced hypothyroidism. Experiments employing T4- supplementation suggests that the toxicity is more complex. Rats... supplementation was continued through the day prior to sacrifice. The liver enzymes c-glycerolphosphate dehydro- genase (GPD) and malic enzyme (ME) were...T4 supplementation had differential effects on anorexia, body wasting and hypothermia. Thyroxine supplementation completely prevented the PFDA-induced

Synthesis and antifungal activity of natural product-based 6-alkyl-2 3 4 5-tetrahydropyridines

USDA-ARS?s Scientific Manuscript database

Seven 6-alkyl-2,3,4,5-tetrahydropyridines (5a–5g) that mimic the natural products piperideines that were recently identified in the fire ant venom have been synthesized. Compounds 5c–5g with the C-6 alkyl chain lengths from C14 to C18 showed varying degrees of antifungal activities, with 5e (6-hexa...

Design of hydrophobic polyoxometalate hybrid assemblies beyond surfactant encapsulation.

PubMed

Song, Yu-Fei; McMillan, Nicola; Long, De-Liang; Thiel, Johannes; Ding, Yulong; Chen, Haisheng; Gadegaard, Nikolaj; Cronin, Leroy

2008-01-01

Grafting of C-6, C-16 and C-18 alkyl chains onto the hydrophilic Mn-Anderson clusters (compounds 2-4) has been achieved. Exchange of the tetrabutyl ammonium (TBA) with dimethyldioctadecyl ammonium (DMDOA) results in the formation of new polyoxometalate (POM) assemblies (compounds 5-6), in which the POM cores are covalently functionalized by hydrophilic alkyl-chains and enclosed by surfactant of DMDOABr. As a result, we have been able to design and synthesize POM-containing hydrophobic materials beyond surfactant encapsulation. In solid state, scanning electron and transmission electron microscopy (SEM and TEM) studies of the TBA salts of compounds 3 and 4 show highly ordered, uniform, reproducible assemblies with unique segmented rodlike morphology. SEM and TEM studies of the DMDOA salts of compounds 5 and 6 show that they form spherical and sea urchin 3D objects in different solvent systems. In solution, the physical properties of compound 5 and 6 (combination of surfactant-encapsulated cluster (SEC) and surface-grafted cluster (SGC)) show a liquid-to-gel phase transition in pure chloroform below 0 degrees C, which are much lower than other reported SECs. By utilizing light scattering measurements, the nanoparticle size for compounds 5 and 6 were measured at 5 degrees C and 30 degrees C, respectively. Other physical properties including differential scanning calorimetry have been reported.

The preparation of new perfluoro ether fluids exhibiting excellent thermal-oxidative stabilities

NASA Technical Reports Server (NTRS)

Jones, William R., Jr.; Bierschenk, Thomas R.; Juhlke, Timothy J.; Kawa, Hajima; Lagow, Richard J.

1988-01-01

A series of low molecular weight perfluoroalkyl ethers (PFAEs) were synthesized by direct fluorination. Viscosity-temperature properties and oxidation stabilities were determined. Viscosity-temperature correlations indicated that increases in branching and increases in the size of the branching substituent caused a deterioration in viscometric properties (i.e., an increase in ASTM slope). In addition, increasing the ratio of carbon to oxygen in these compounds also increased the ASTM slope. Preliminary oxidation stability measurements indicated that highly branched PFAE fluids (i.e., those containing quaternary carbons) may be less stable than either those containing a single trifluoromethyl pendant group or those containing no branching at all.

Membrane separation of ionic liquid solutions

DOEpatents

Campos, Daniel; Feiring, Andrew Edward; Majumdar, Sudipto; Nemser, Stuart

2015-09-01

A membrane separation process using a highly fluorinated polymer membrane that selectively permeates water of an aqueous ionic liquid solution to provide dry ionic liquid. Preferably the polymer is a polymer that includes polymerized perfluoro-2,2-dimethyl-1,3-dioxole (PDD). The process is also capable of removing small molecular compounds such as organic solvents that can be present in the solution. This membrane separation process is suitable for drying the aqueous ionic liquid byproduct from precipitating solutions of biomass dissolved in ionic liquid, and is thus instrumental to providing usable lignocellulosic products for energy consumption and other industrial uses in an environmentally benign manner.

Preparation of a Highly Fluorophilic Phosphonium Salt and its Use in a Fluorous Anion-Exchanger Membrane with High Selectivity for Perfluorinated Acids

PubMed Central

Boswell, Paul G.; Anfang, Alyce C.; Bühlmann, Philippe

2008-01-01

Fluorous solvents are the most nonpolar, nonpolarizable phases known, whereas ions are inherently polar. This makes it difficult to create salts that are soluble in a fluorous solvent. Here we present the synthesis and characterization of a new fluorophilic phosphonium salt, tris{3,5-bis[(perfluorooctyl)propyl]phenyl}methylphosphonium methyl sulfate. The salt has a solubility of at least 14 mM in perfluoro(perhydrophenanthrene), perfluoro(methylcyclohexane), and perfluorohexanes. It also shows immediate potential for use as a phase-transfer catalyst in fluorous biphasic catalysis, but in this work it is used as an anion exchanger site in the first potentiometric fluorous-membrane anion-selective electrode. The membrane sensor exhibited the exceptional selectivity of 3.9 × 1010 to 1 for perfluorooctanesulfonate over chloride, and of 2.5 × 107 to 1 for perfluorooctanoate over chloride. With improvements to the sensor’s detection limit and lifetime, it has the potential to be an attractive alternative to the expensive, time-consuming methods currently employed for measurement of perfluorinated acids. PMID:22072222

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

PubMed

Lorenzo, José M

2014-01-01

The changes in the physico-chemical and textural properties, lipolysis and volatile compounds during the manufacture of dry-cured foal "cecina" were studied. The pH increased during the last stages of processing but gradually declined over the curing period. TBARS values, hardness and chewiness increased with processing time from 0.14, 2.74 and 0.83 to 3.49 mg malonaldehyde/kg, 20.33 kg and 5.05 kg∗mm, respectively. Ripening time also affected the colour parameters: lightness (L*), redness (a*) and yellowness (b*) (P<0.001). The total average content of free fatty acid (FFA) increased significantly from 433.7 mg/100 g of fat in the raw pieces to 2655.5 mg/100 g of fat at the end of the drying-ripening stage. The main FFA at the end of the manufacturing process was palmitic acid (C16:0), followed by oleic (C18:1cis9), stearic (C18:0) and linoleic (C18:2n-6). A total of fifty five volatile compounds were identified during the manufacture of dry-cured foal "cecina", including esters, aldehydes, aliphatic hydrocarbons, branched hydrocarbons, alcohols, aromatic hydrocarbons, furans, ketones. Aldehydes reached their maximum level at the end of the post-salting stage. In the final product, esters became the dominant chemical compounds. © 2013.

Synthesis and Pharmacological Evaluation of [11C]Granisetron and [18F]Fluoropalonosetron as PET Probes for 5-HT3 Receptor Imaging.

PubMed

Mu, Linjing; Müller Herde, Adrienne; Rüefli, Pascal M; Sladojevich, Filippo; Milicevic Sephton, Selena; Krämer, Stefanie D; Thompson, Andrew J; Schibli, Roger; Ametamey, Simon M; Lochner, Martin

2016-11-16

Serotonin-gated ionotropic 5-HT 3 receptors are the major pharmacological targets for antiemetic compounds. Furthermore, they have become a focus for the treatment of irritable bowel syndrome (IBS) and there is some evidence that pharmacological modulation of 5-HT 3 receptors might alleviate symptoms of other neurological disorders. Highly selective, high-affinity antagonists, such as granisetron (Kytril) and palonosetron (Aloxi), belong to a family of drugs (the "setrons") that are well established for clinical use. To enable us to better understand the actions of these drugs in vivo, we report the synthesis of 8-fluoropalonosetron (15) that has a binding affinity (K i = 0.26 ± 0.05 nM) similar to the parent drug (K i = 0.21 ± 0.03 nM). We radiolabeled 15 by nucleophilic 18 F-fluorination of an unsymmetrical diaryliodonium palonosetron precursor and achieved the radiosynthesis of 1-(methyl- 11 C)-N-granisetron ([ 11 C]2) through N-alkylation with [ 11 C]CH 3 I, respectively. Both compounds [ 18 F]15 (chemical and radiochemical purity >95%, specific activity 41 GBq/μmol) and [ 11 C]2 (chemical and radiochemical purity ≥99%, specific activity 170 GBq/μmol) were evaluated for their utility as positron emission tomography (PET) probes. Using mouse and rat brain slices, in vitro autoradiography with both [ 18 F]15 and [ 11 C]2 revealed a heterogeneous and displaceable binding in cortical and hippocampal regions that are known to express 5-HT 3 receptors at significant levels. Subsequent PET experiments suggested that [ 18 F]15 and [ 11 C]2 are of limited utility for the PET imaging of brain 5-HT 3 receptors in vivo.

Analysis of Organic Anionic Surfactants in Fine and Coarse Fractions of Freshly Emitted Sea Spray Aerosol

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

Cochran, Richard E.; Laskina, Olga; Jayarathne, Thilina

The inclusion of organic compounds in freshly emitted sea spray aerosol (SSA) has been shown to be size-dependent, with an increasing organic fraction in smaller particles. Defining the molecular composition of sea spray aerosol has proven challenging, due to the mix of continental and background particles even in remote marine environments. Here we have used electrospray ionization-high resolution mass spectrometry in negative ion mode to identify organic compounds in nascent sea spray collected throughout a 25-day mesocosm experiment. Over 280 organic compounds from ten major homologous series were identified. These compounds were operationally defined as molecules containing a hydrophobic alkylmore » chain with a hydrophilic head group making them surface active. The most abundant class of molecules detected were saturated (C8–C24) and unsaturated (C12–C22) fatty acids. Fatty acid derivatives (including saturated oxo-fatty acids (C5–C18) and saturated hydroxy-fatty acids (C5–C18) were also identified. Interestingly, anthropogenic influences on SSA from the seawater were observed in the form of sulfate (C2–C7, C12–C17) and sulfonate (C16–C22) species. During the mesocosm, the distributions of molecules within each homologous series were observed to respond to variations among the levels of phytoplankton and bacteria in the seawater, indicating an important role of biological processes in determining the composition of SSA.« less

Perfluoroalkyl Sulfonates and Carboxylic Acids in Liver, Muscle and Adipose Tissues of Black-Footed Albatross (Phoebastria nigripes) from Midway Island, North Pacific Ocean

PubMed Central

Chu, Shaogang; Wang, Jun; Leong, Gladys; Woodward, Lee Ann; Letcher, Robert J.; Li, Qing X.

2015-01-01

The Great Pacific Garbage Patch (GPGP) is a gyre of marine plastic debris in the North Pacific Ocean, and nearby is Midway Atoll which is a focal point for ecological damage. This study investigated 13 C4-C16 perfluorinated carboxylic acids (PFCAs), four (C4, C6, C8 and C10) perfluorinated sulfonates and perfluoro-4-ethylcyclohexane sulfonate [collectively perfluoroalkyl acids (PFAAs)] in black-footed albatross tissues (collected in 2011) from Midway Atoll. Of the 18 PFCAs and PFSAs monitored, most were detectable in the liver, muscle and adipose tissues. The concentrations of PFCAs and PFSAs were higher than those in most seabirds from the arctic environment, but lower than those in most of fish-eating water birds collected in the U.S. mainland. The concentrations of the PFAAs in the albatross livers were 7-fold higher than those in Laysan albatross liver samples from the same location reported in 1994. The concentration ranges of PFOS were 22.91-70.48, 3.01-6.59 and 0.53-8.35 ng g-1 wet weight (ww), respectively, in the liver, muscle and adipose. In the liver samples PFOS was dominant, followed by longer chain PFUdA (8.04-18.70 ng g-1 ww), PFTrDA, and then PFNA, PFDA and PFDoA. Short chain PFBA, PFPeA, PFBS and C16 PFODA were below limit of quantification. C8-C13 PFCAs showed much higher composition compared to those found in other wildlife where PFOS typically predominated. The concentrations of PFUdA in all 8 individual albatross muscle samples were even higher than those of PFOS. This phenomenon may be attributable to GPGP as a pollution source as well as PFAA physicochemical properties. PMID:26037817

Two-Dimensional Electrophoretic Analysis of Subcellular Liver Fractions and Isolated Hepatocytes from Normal and PFDA Treated Rats

DTIC Science & Technology

1990-05-28

Continue on reverse if necessary and identify by block number) FIELD GROUP SUB-GROUP perfluoro.n-decanoic acid ; two-dimensional electrophoresis...hepatotoxicity; cell fractions; liver 1 t ABSTRACT (Continue on reverse if necessary and identify by block number) Perfluoro-n-decanoic acid (PFDA) effects...Unu::’-. ’. I AFOSR Ju .T , Building 410 Bolling AFB, DC 20332-6448 By Dist V’ lml mm mm i INTRODUCTION Perfluorocarboxylic acids and other

The Molecular Anatomy of PFDA Hepatotoxicity as Studied by Two- Dimensional Electrophoresis.

DTIC Science & Technology

1991-01-03

Available Copy 93 06 124 Page 3 INTRODUCTION Perfluoro -n-decanoic acid ( PFDA ) is a ten carbon straight-chain perfluorinated carboxylic acid whose surfactant...Rats were injected with a single intraperitoneal dose of 2, 20, 50, or 100 mg PFDA /kg body weight; 75, 100, 150 mg PFOA /kg (eight carbon analog); or 3...TERMS (Continue on reverse if necessary and identify by block number) FIELD IGROUP SUB-GROUP perfluoro -n-decanoic acid; two-dimensional electro- P

Perfluoro (Imidoylamidine) diamidines

NASA Technical Reports Server (NTRS)

Rosser, R. W.; Chen, T. S.; Cheng, C. H. (Inventor)

1986-01-01

Perfluoroether triazine elastomers having improved properties are prepared from oligomeric imidoylamidines that were in turn, prepared by the process of: (1) reacting a perfluorodinitrile with liquid ammonia to yield a perfluorodiamidine, (2) isolating the perfluorodiamidine, (3) reacting the isolated diamidine with a perfluorodinitrile to yield a perfluoro(imidoylamidine) dinitrile, and then repeating the steps to sequentially grow an oligomer of desired molecular size. The isolated amidine and nitrile intermediates are also disclosed. The elastomers can be fashioned into seals, gaskets, and sealing components and the like.

Synthesis and QSAR study of novel α-methylene-γ-butyrolactone derivatives as antifungal agents.

PubMed

Wu, Yong-Ling; Wang, De-Long; Guo, En-Hui; Song, Shuang; Feng, Jun-Tao; Zhang, Xing

2017-03-01

Thirty-six new α-benzylidene-γ-lactone compounds based α-methylene-γ-butyrolactone substructure were prepared and characterized by spectroscopic analysis. All compounds were evaluated for antifungal activities in vitro against six plant pathogenic fungi and the half maximal inhibitory concentration (IC 50 ) against Botrytis cinerea and Colletotrichum lagenarium were investigated. Compounds 5c-3 and 5c-5 with the halogen atom exhibited excellent fungicidal activity against B. cinerea (IC 50 =22.91, 18.89μM). The structure-activity relationships (SARs) analysis indicated that the derivatives with electron-withdrawing substituents at the meta- or para-positions improves the activity. Via the heuristic method, the generated quantitative structure-activity relationship (QSAR) model (R 2 =0.961) revealed a strong correlation of antifungal activity against B. cinerea with molecular structures of these compounds. Meanwhile, the cytotoxicity of 20 representative derivatives was tested in the human tumor cells line (HepG2) and the hepatic L02 cells line, the result indicated that the synthesized compounds showed significant inhibitory activity and limited selectivity. Compound 5c-5 has the highest fungicidal activity with IC 50 =18.89μM (against B. cinerea.) but low cytotoxicity with IC 50 =35.4μM (against HepG2 cell line) and IC 50 =68.8μM (against Hepatic L02 cell line). These encouraging results can be providing an alternative, promising use of α-benzylidene-γ-lactone through the design and exploration of eco-friendly fungicides with low toxicity and high efficiency. Copyright © 2017 Elsevier Ltd. All rights reserved.

Method for pulse control in a laser including a stimulated brillouin scattering mirror system

DOEpatents

Dane, C. Brent; Hackel, Lloyd; Harris, Fritz B.

2007-10-23

A laser system, such as a master oscillator/power amplifier system, comprises a gain medium and a stimulated Brillouin scattering SBS mirror system. The SBS mirror system includes an in situ filtered SBS medium that comprises a compound having a small negative non-linear index of refraction, such as a perfluoro compound. An SBS relay telescope having a telescope focal point includes a baffle at the telescope focal point which blocks off angle beams. A beam splitter is placed between the SBS mirror system and the SBS relay telescope, directing a fraction of the beam to an alternate beam path for an alignment fiducial. The SBS mirror system has a collimated SBS cell and a focused SBS cell. An adjustable attenuator is placed between the collimated SBS cell and the focused SBS cell, by which pulse width of the reflected beam can be adjusted.

Stimulated Brillouin scattering mirror system, high power laser and laser peening method and system using same

DOEpatents

Dane, C Brent [Livermore, CA; Hackel, Lloyd [Livermore, CA; Harris, Fritz B [Rocklin, CA

2007-04-24

A laser system, such as a master oscillator/power amplifier system, comprises a gain medium and a stimulated Brillouin scattering SBS mirror system. The SBS mirror system includes an in situ filtered SBS medium that comprises a compound having a small negative non-linear index of refraction, such as a perfluoro compound. An SBS relay telescope having a telescope focal point includes a baffle at the telescope focal point which blocks off angle beams. A beam splitter is placed between the SBS mirror system and the SBS relay telescope, directing a fraction of the beam to an alternate beam path for an alignment fiducial. The SBS mirror system has a collimated SBS cell and a focused SBS cell. An adjustable attenuator is placed between the collimated SBS cell and the focused SBS cell, by which pulse width of the reflected beam can be adjusted.

A Study of Spur Gears Lubricated With Grease-Observations From Seven Experiments

NASA Technical Reports Server (NTRS)

Krantz, Timothy L.; Handschuh, Robert F.

2005-01-01

To improve understanding of gears operating with a perfluoro type space-qualified grease, seven spur gear experiments were performed. Test conditions were selected to study the influences of torque, lubricant type, and atmosphere. Two testing torques provided nominal pitch-line Hertz stresses greater and lesser than the contact stress limit as recommended by the grease manufacturer. As was expected, all tests resulted in some gear tooth wear. Discoloration of the perfluoro type grease occurred for all tests. Tests in dry nitrogen produced some dark-grey colored perfluoro type grease. Testing in either ambient or dry air produced red debris after short test duration, and for tests of longer duration large amounts of red debris, red grease, and wear were evident. Tests using higher torques produced more debris. The first indications of discoloration occurred more quickly with higher test torques. Total amounts of wear were quite significant, up to four times the profile tolerance for AGMA Class 10 gears.

Synthesis of new high performance lubricants and solid lubricants

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

Lagow, Richard J.

1993-04-08

In our second year of funding we began the testing phase of a number of new classes of lubricants. Three different testing collaborations have already begun and a fourth one is In the works with Dr. Stephen Hsu of the National Institute of Standards and Technology. Dr. Hsu also plans to test some of the same materials for us that Shell Development is studying. With Dr. Bill Jones of NASA, we are studying the effects of branching an high temperature lubricant properties in perfluoropolyethers, Initially Bill Jones is comparing the lubrication and physical properties of perfluorotetraglyme and the following twomore » spherical perfluoropolyethers, Note that one contains a fluorocarbon chain and the other one contains a fluorocarbon ether chain. The synthesis of these was reported in the last progress report. With Professor Patricia Thiel of Iowa State University, we are working on studies of perfluoromethylene oxide ethers and have prepared a series of four of these polyethers to study in collaboration with her research group. These perfluoromethylene oxide ethers have the best low temperature properties of any known lubricants. Thiel's group is studying their interactions with metals under extreme conditions. Thirdly, we have also begun an Interaction with W. August Birke of Shell Development Company in Houston for whom we have already prepared samples of the chlorine-substituted fluorocarbon polyether lubricants whose structures appear on page 54 of our research proposal. Each of these four structures is thought to have potential as lubricant additives to motor oils. We also have underway syntheses of other fluorine-containing branched ether lubricants. These new materials which are also promising as antifriction additives for motor oils appear ahead of the perfluoro additives as Appendix I to the progress report. Additionally for Birke and Shell Development we have at their request prepared the novel compound perfluoro salicylic acid. This synthesis was suggested by the Shell staff who thought that esters of perfluoro salicylic acid might be an excellent antifriction additive for motor oil fuels. One of the best additives currently used in motor oils is the hydrocarbon ester of salicylic acid.« less

Cytotoxic deoxybenzoins and diphenylethylenes from Arundina graminifolia.

PubMed

Hu, Qiu-Fen; Zhou, Bin; Ye, Yan-Qing; Jiang, Zhi-Yong; Huang, Xiang-Zhong; Li, Yin-Ke; Du, Gang; Yang, Guang-Yu; Gao, Xue-Mei

2013-10-25

Eight new C-4-alkylated deoxybenzoins (1-8), three new diphenylethylenes (9-11), and five known diphenylethylenes were isolated from Arundina graminifolia. The structures of 1-11 were elucidated by spectroscopic methods including extensive 1D and 2D NMR techniques. Compounds 9-11 are the first naturally occurring diphenylethylenes possessing a hydroxyethyl unit. Compounds 1-11 were evaluated for cytotoxicity against five human tumor cell lines. Compounds 4, 5, and 9-11 showed significant cytotoxicity against five cancer cell lines, with IC50 values ranging from 1.8 to 8.7 μM.

Superhydrophobic aerogel that does not require per-fluoro compounds or contain any fluorine

DOEpatents

Kissel, David J.; Brinker, Charles Jeffrey

2015-05-26

Provided are superhydrophobic coatings, devices and articles including superhydrophobic coatings, and methods for preparing the superhydrophobic coatings. The exemplary superhydrophobic device can include a substrate component and one or more superhydrophobic coatings disposed over the substrate component, wherein at least one of the one or more superhydrophobic coatings has a water contact angle of at least about 150.degree. and a contact angle hysteresis of less than about 1.degree.. The one or more superhydrophobic coatings can include an ultra high water content acid catalyzed polysilicate gel, the polysilicate gel including a three dimensional network of silica particles having surface functional groups derivatized with a silylating agent and a plurality of pores.

Mono- and dinuclear tetraphosphabutadiene ferrate anions.

PubMed

Chakraborty, Uttam; Leitl, Julia; Mühldorf, Bernd; Bodensteiner, Michael; Pelties, Stefan; Wolf, Robert

2018-03-12

Reduction of [Cp Ar Fe(μ-Br)] 2 (1, Cp Ar = C 5 (C 6 H 4 -4-Et) 5 ) by potassium napthalenide, followed by the addition of white phosphorus, affords [K(18-c-6){Cp Ar Fe(η 4 -P 4 )}] (2, 18-c-6 = [18]crown-6), which features a planar cyclo-P 4 2- ligand. The related diiron complex [Na 2 (THF) 5 (Cp Ar Fe) 2 (μ,η 4:4 -P 4 )] (3) was obtained by reducing 1 with sodium amalgam in the presence of P 4 . Protonation of 3 affords [Na(THF) 3 ][(Cp Ar Fe) 2 (μ,η 4:4 -P 4 )(H)] (4), while the reaction of 3 with trimethylchlorosilane gives the nortricyclane compound P 7 (SiMe 3 ) 3 as the main product.

Biodegradation of crude oil in Arctic subsurface water from the Disko Bay (Greenland) is limited.

PubMed

Scheibye, Katrine; Christensen, Jan H; Johnsen, Anders R

2017-04-01

Biological degradation is the main process for oil degradation in a subsurface oil plume. There is, however, little information on the biodegradation potential of Arctic, marine subsurface environments. We therefore investigated oil biodegradation in microcosms at 2 °C containing Arctic subsurface seawater from the Disko Bay (Greenland) and crude oil at three concentrations of 2.5-10 mg/L. Within 71 days, the total petroleum hydrocarbon concentration decreased only by 18 ± 18% for an initial concentration of 5 mg/L. The saturated alkanes nC13-nC30 and the isoprenoids iC18-iC21 were biodegraded at all concentrations indicating a substantial potential for biodegradation of these compound classes. Polycyclic aromatic compounds (PACs) disappeared from the oil phase, but dissolution was the main process of removal. Analysis of diagnostic ratios indicated almost no PAC biodegradation except for the C1-naphthalenes. To conclude, the marine subsurface microorganisms from the Disko Bay had the potential for biodegradation of n-alkanes and isoprenoids while the metabolically complex and toxic PACs and their alkylated homologs remained almost unchanged. Copyright © 2016 Elsevier Ltd. All rights reserved.

Methyl 3-amino-4-butanamido-5-methyl­benzoate

PubMed Central

Li, Xiang; Yuan, Lian-shan; Wang, Dan; Yao, Cheng

2008-01-01

The title compound, C13H18N2O3, is an inter­mediate in the synthesis of compounds with medicinial applications. The crystal structure is stabilized by inter­molecular N—H⋯O, C—H⋯N and C—H⋯O hydrogen bonds. PMID:21202582

Adsorption behaviors of neutral and ionizable compounds on hybrid stationary phases in the absence (BEH-C18) and the presence (CSH-C18) of immobile surface charges.

PubMed

Gritti, Fabrice; Guiochon, Georges

2013-03-22

The adsorption behaviors of a neutral (caffeine) and a positively charged compound (nortriptylinium) are investigated on two RPLC/hybrid stationary phases, eluted with a low ionic strength buffer (phosphate buffer, W(S)pH 2.63, I=10mM). The first phase, bridge ethylene hybrid (BEH), is neutral at all pHs whereas the second, charged surface hybrid (CSH), contains a protonated ligand at W(W)pH <7. The band profiles of these two compounds eluted by mixture of acetonitrile and water were recorded under overloaded conditions. The adsorption isotherms of the neutral compound on both columns were well accounted for by a heterogeneous Linear-Langmuir (LL) model, which has an adsorption-desorption equilibrium constants about twice larger for caffeine on the CSH than on the BEH, due to charge-dipole interactions. In contrast, at low loadings (0.3 and 1.2μL, C=30g/L), the adsorption isotherm of the charged compound can be accounted for by a homogeneous electrostatically modified Langmuir (EML) or by a heterogeneous bi-EML implicit isotherms onto the CSH and BEH adsorbent, respectively. Electrostatic repulsions definitely account the lesser retention of the ionizable compound on CSH than on BEH. This is explained by the surface potential of CSH-C18 at 20mV and by the subsequent decrease of the equilibrium constant of weak adsorption sites (C18 environment) and removal of the strong adsorption sites (accessible silanols). At the highest sample loadings (5 and 20μL, C=30g/L), the EML and the bi-EML isotherms failed because some adsorbate-adsorbate interactions take place when bulk concentrations exceed 0.2g/L. The experimental data were then successively fitted to an empirical heterogeneous Langmuir-Moreau (LM) explicit isotherm. The best saturation capacities of the empirical heterogeneous LM isotherm is consistent with the manufacturer's estimate of the surface concentration of residual silanols onto the BEH- and CSH-C18 endcapped adsorbent (<0.1μmol/m(2)). Copyright © 2013 Elsevier B.V. All rights reserved.

Novel Energetic Compounds Based on 3-Methyl-1,2,5-Oxadiazole 2-Oxide

NASA Astrophysics Data System (ADS)

Xu, Zhen; Yang, Hongwei; Cheng, Guangbin

2018-01-01

Two derivatives of 3-methyl-1,2,5-oxadiazole 2-oxide, (E) 4-methyl-1,2,5-oxadiazole-3-carboxaldehyde 5-oxide (2,4,6-trinitrophenyl)hydrazone (1) and 2,2,2-trinitroethyl 4-methyl-1,2,5-oxadiazole-3-carboxylate 5-oxide (2), were designed, synthesized, and fully characterized. The structures of the new compounds were confirmed by single-crystal X-ray analysis. Physicochemical and energetic properties including density, thermal stability, and sensitivity were investigated, and energetic properties (e.g., detonation velocities and detonation pressures) were calculated using EXPLO5 code. The results indicated that compound 1 exhibits positive heat of formation of 448.0 kJ mol-1 and acceptable sensitivities (IS: 20 J, FS: 280 N). In addition, compound 2 possesses low melting point (99.92°C), moderate decomposition temperature (183.67°C), good detonation performances (D: 8430 m s-1; P: 31.5 GPa), and lower sensitivities (IS: 18 J; FS: 220 N), which suggest 2 has the potential to be melt-cast explosive.

Sorption of amitriptyline and amphetamine to mixed-mode solid-phase microextraction in different test conditions.

PubMed

Peltenburg, Hester; Droge, Steven T J; Hermens, Joop L M; Bosman, Ingrid J

2015-04-17

A solid-phase microextraction (SPME) method based on a sampler coating that includes strong cation groups (C18/SCX) is explored as a rapid direct sampling tool to detect and quantify freely dissolved basic drugs. Sampling kinetics, sorption isotherms and competitive effects on extraction yields in mixtures were tested for amphetamine and the relatively large/hydrophobic tricyclic antidepressant amitriptyline. Both compounds are >99% ionized at pH 7.4 but their affinity for the C18/SCX fiber is markedly different with distribution coefficients (Dfw values) of 2.49±0.02 for amphetamine and 4.72±0.10 for amitriptyline. Typical changes in electrolyte homeostasis that may occur in biomedical samples were simulated by altering pH and ionic composition (Na(+) and K(+) concentrations). These changes were shown to affect C18/SCX sorption affinities of the tested drugs with less than 0.2log units. At relatively low fiber loadings (<10mmol/L coating) and at all tested exposure times, linear sorption isotherms were obtained for both compounds but at aqueous concentrations of the individual drugs corresponding to concentrations in blood that are lethal, sorption isotherms became strongly nonlinear. Competition effects within binary mixtures occurred only if combinations of aqueous concentrations resulted in total fiber loadings that were in the nonlinear range of the SPME sorption isotherm for the individual compounds. We also compared sorption to the (prototype) C18/SCX SPME coating with analogue (biocompatible) C18 coated SPME fibers. C18/SCX fibers show increased sorption affinity for cationic compounds compared to C18 fibers, as tested using amitriptyline, amphetamine and trimethoprim. Surprisingly, sorption affinity of these ionized compounds for the C18 SPME fibers were within 1log unit of the C18/SCX SPME fibers. This shows that the strong cation exchange groups within the C18/SCX coating only has a relatively small contribution to the total sorption affinity of cationic compounds. Also the role of negatively charged silanol groups in both the C18 and C18/SCX coating seems small, as anionic diclofenac species sorbed strongly to the C18 fiber. Ionized organic species seem to be substantially adsorbed to the high surface area of C18 in SPME types using porous silica based coatings. Copyright © 2015 Elsevier B.V. All rights reserved.

Synthesis and properties of the compound: LiNi 3/5Cu 2/5VO 4

NASA Astrophysics Data System (ADS)

Ram, Moti

2009-12-01

The LiNi 3/5Cu 2/5VO 4 is synthesized by solution-based chemical method and its formation has been checked by X-ray diffraction (XRD) study. XRD study shows a tetragonal unit cell structure with lattice parameters of a = 11.6475 (18) Å, c = 2.4855 (18) Å and c/ a = 0.2134 Å. Electrical properties are verified using complex impedance spectroscopy (CIS) technique. Complex impedance analysis reveals following points: (i) the bulk contribution to electrical properties up to 200 °C, (ii) the bulk and grain boundary contribution at T ≥ 225 °C, (iii) the presence of temperature dependent electrical relaxation phenomena in the material. D.c. conductivity study indicates that electrical conduction in the material is a thermally activated process.

Electrochemical, spectroscopic, and DFT study of C60(CF3)n frontier orbitals (n = 2-18): the link between double bonds in pentagons and reduction potentials.

PubMed

Popov, Alexey A; Kareev, Ivan E; Shustova, Natalia B; Stukalin, Evgeny B; Lebedkin, Sergey F; Seppelt, Konrad; Strauss, Steven H; Boltalina, Olga V; Dunsch, Lothar

2007-09-19

The frontier orbitals of 22 isolated and characterized C(60)(CF(3))(n) derivatives, including seven reported here for the first time, have been investigated by electronic spectroscopy (n = 2 [1], 4 [1], 6 [2], 8 [5], 10 [6], 12 [3]; the number of isomers for each composition is shown in square brackets) fluorescence spectroscopy (n = 10 [4]), cyclic voltammetry under air-free conditions (all compounds with n

[Study on Chemical Constituents from Roots of Lonicera macranthoides].

PubMed

Liu, Wen-juan; Chen, Yu; Ma, Xin; Zhao, You-yi; Feng, Xu

2014-12-01

To study chemical constituents of the roots of Lonicera macranthoides. The chemical constituents were isolated and purified by means of several chromatographic techniques and their structures were elucidated by spectroscopic methods. Seven compounds were isolated and identified as ribenol (1), excoecarin C (2), 18-hydroxy-13-epi-manoyloxide (3), asiatic acid (4), oleanolic acid (5), β-sitosterol (6) and β-daucosterol (7). Compounds 1-4 are obtained from this genus for the first time. Compound 5 is obtained from this plant for the first time. All the compounds are found from the roots of Lonicera mac- ranthoides for the first time.

Organic aerosols in the southeastern United States: Speciated particulate carbon measurements from the SEARCH network, 2006-2010

NASA Astrophysics Data System (ADS)

Blanchard, C. L.; Chow, J. C.; Edgerton, E. S.; Watson, J. G.; Hidy, G. M.; Shaw, S.

2014-10-01

This study describes and analyzes measurements of 119 non-polar organic compounds in PM2.5 samples from three urban sites in the Southeastern Aerosol Research and Characterization (SEARCH) network: Jefferson Street in Atlanta, Georgia (JST), Birmingham, Alabama (BHM), and Hinton, Texas (HIN). Daily 24-h PM2.5 samples were collected on quartz-fiber filters from January 2006 through 2007 at HIN and from March 2006 through 2010 at JST and BHM. PM2.5 sampling at BHM and JST is ongoing. The measured species are associated with directly emitted particles and potentially serve as tracers of specific types of emissions. PM2.5 organic measurements include 28 n-alkanes (C15-C42), 18 iso-/anteiso-alkanes (C29-C37), 2 methyl alkanes, 3 branched alkanes, 5 cycloalkanes, 32 PAH compounds, 18 hopanes, 12 steranes, and 1 alkene, many of which are constituents of motor-vehicle exhaust and other anthropogenic PM2.5 emissions. Predominantly anthropogenic origins of the measured compounds are indicated by weekly and seasonal cycles that are identified with known emission patterns, especially for motor vehicle usage. Annual mean concentrations of each class of compounds declined by 60-90% from 2006 through 2009, then increased in 2010 to concentrations comparable to 2008. These changes are similar to 40% reductions of on-road and non-road motor-vehicle exhaust PM2.5 emissions between 2006 and 2010. Year-to-year variations in OC correlated with year-to-year variations in measured non-polar compound concentrations. Regression of OC against the sums of measured n-alkanes, iso-/anteiso-alkanes, PAHs, hopanes, and steranes indicates that 32 ± 7% of OC at BHM and 35 ± 4% of OC at JST derived from sources emitting the measured non-polar compounds. The reductions in measured concentrations of EC, OC, and non-polar OC species represent an important improvement in air quality in the southeastern U.S. that can be attributed by the long-term measurement program to PM2.5 emission reductions.

rac-(S,S)-Bis(1-ferrocenylbut-3-en-yl) ether.

PubMed

Xie, Hao-Jun; Zhao, Chun-Zheng; Sun, Jun; Chen, Si; Wang, Jian-Jun

2013-01-01

The title complex, [Fe2(C5H5)2(C18H20O)], formed by dehydration of 1-ferrocenylbut-3-en-1-ol, crystallizes as a racemic compound. The central C-O-C fragment, in which the C atoms are the chiral centers, is characterized by an angle of 116.26 (10)° at the O atom. One ferrocene group shows a staggered conformation whereas the other shows an eclipsed conformation.

Characterization of five passive sampling devices for monitoring of pesticides in water.

PubMed

Ahrens, Lutz; Daneshvar, Atlasi; Lau, Anna E; Kreuger, Jenny

2015-07-31

Five different passive sampler devices were characterized under laboratory conditions for measurement of 124 legacy and current used pesticides in water. In addition, passive sampler derived time-weighted average (TWA) concentrations were compared to time-integrated active sampling in the field. Sampling rates (RS) and passive sampler-water partition coefficients (KPW) were calculated for individual pesticides using silicone rubber (SR), polar organic chemical integrative sampler (POCIS)-A, POCIS-B, Chemcatcher(®) SDB-RPS and Chemcatcher(®) C18. The median RS (Lday(-1)) decreased as follows: SR (0.86)>POCIS-B (0.22)>POCIS-A (0.18)>Chemcatcher(®) SDB-RPS (0.05)>Chemcatcher(®) C18 (0.02), while the median logKPW (Lkg(-1)) decreased as follows: POCIS-B (4.78)>POCIS-A (4.56)>Chemcatcher(®) SDB-RPS (3.17)>SR (3.14)>Chemcatcher(®)C18 (2.71). The uptake of the selected compounds depended on their physicochemical properties, i.e. SR showed a better uptake for more hydrophobic compounds (log octanol-water partition coefficient (KOW)>5.3), whereas POCIS-A, POCIS-B and Chemcatcher(®) SDB-RPS were more suitable for hydrophilic compounds (logKOW<0.70). Overall, the comparison between passive sampler and time-integrated active sampler concentrations showed a good agreement and the tested passive samplers were suitable for capturing compounds with a wide range of KOW's in water. Copyright © 2015 Elsevier B.V. All rights reserved.

Review of Portable, Manually Operated, and Non-Total Flooding Fire Extinguishing Technologies for Use on Naval Vessels

DTIC Science & Technology

2011-12-01

Corrosion problems arising from the use of perfluoro-or hydrofluorocarbon agents have been investigated and are of concern. The concern centers on the...which was formerly known as Powdered Aerosol B, can be used on Class A, Class B, and Class C fires. These agents are a blend of several halocarbons...Canada Review of Portable, Manually Operated, and Non-Total Flooding Fire Extinguishing Technologies for Use on Naval Vessels Contract Project Manager

Determination of the thermal stability of perfluoroalkylethers by tensimetry: Instrumentation and Procedure

NASA Technical Reports Server (NTRS)

Helmick, Larry S.; Jones, William R., Jr.

1989-01-01

A computerized tensimeter and experimental procedure for determination of the thermal decomposition temperature (T sub d) of perfluoro alkylethers were developed and tested. Both the apparatus and the procedure are described in detail. Results of testing with bis(2-ethylhexyl) phthalate and trimethylolpropane triheptanoate demonstrate that the reciprocal of the decomposition temperature is a linear function of the logarithm of the gas volume/heated liquid volume ratio. The T sub d obtained for each compound at a gas volume/heated liquid volume ration of one was similar to the value previously reported using an isoteniscope technique. Results of testing with a polymer of hexafluoropropylene oxide demonstrate that this instrument and procedure can be used to determine the T sub d of perfluoroalkylethers.

Phenolic compounds in hawthorn (Crataegus grayana) fruits and leaves and changes during fruit ripening.

PubMed

Liu, Pengzhan; Kallio, Heikki; Yang, Baoru

2011-10-26

Phenolics in the fruits and leaves of Crataegus grayana were identified by HPLC-UV-ESI-MS. The contents of these compounds and their changes during autumn were also analyzed. Epicatechin [1-7 mg/g dry mass (DM) in fruits and 1-10 mg/g DM in leaves), procyanidins B2 (2-4 and 1-8 mg/g DM) and C1 (2-4 and 1-8 mg/g DM), hyperoside (0.5-1 and 2-11 mg/g DM), and a quercetin-pentoside (0.3-0.5 and 2-6 mg/g DM) were the major phenolics in both fruits and leaves. C-Glycosyl flavones were present in leaves (2-5 mg/g DM), whereas only trace levels were found in fruits. Ideain and 5-O-caffeoylquinic acid were found only in fruits. An additional 11 phenolics were identified/tentatively identified. Total phenolic contents reached highest levels by the end of August in fruits and by the end of September in leaves. The compositional profiles of phenolics in fruits and leaves of C. grayana were different from those of other Crataegus species.

Biodegradation of artificial monolayers applied to water storages to reduce evaporative loss.

PubMed

Pittaway, P; Herzig, M; Stuckey, N; Larsen, K

2015-01-01

Repeat applications of an artificial monolayer to the interfacial boundary layer of large agricultural water storages during periods of high evaporative demand remains the most commercially feasible water conservation strategy. However, the interfacial boundary layer (or microlayer) is ecologically distinct from subsurface water, and repeat monolayer applications may adversely affect microlayer processes. In this study, the natural cleansing mechanisms operating within the microlayer were investigated to compare the biodegradability of two fatty alcohol (C16OH and C18OH) and one glycol ether (C18E1) monolayer compound. The C16OH and C18OH compounds were more susceptible to microbial degradation, but the C18E1 compound was most susceptible to indirect photodegradation. On clean water the surface pressure and evaporation reduction achieved with a compressed C18E1 monolayer was superior to the C18OH monolayer, but on brown water the surface pressure dropped rapidly. These results suggest artificial monolayers are readily degraded by the synergy between photo and microbial degradation. The residence time of C18OH and C18E1 monolayers on clear water is sufficient for cost-effective water conservation. However, the susceptibility of C18E1 to photodegradation indicates the application of this monolayer to brown water may not be cost-effective.

Synthesis and characterization of two novel inorganic/organic hybrid materials based on polyoxomolybdate clusters: (C5H5N5)2(C5H6N5)4[(HAsO4)2Mo6O18]·11H2O and Na2(Himi)3[SeMo6O21(CH3COO)3]·6H2O

NASA Astrophysics Data System (ADS)

Ayed, Meriem; Mestiri, Imen; Ayed, Brahim; Haddad, Amor

2017-01-01

Two new organic-inorganic hybrid compound, (C5H5N5)2(C5H6N5)4[(HAsO4)2Mo6O18]·11H2O (I) and Na2(Himi)3[SeMo6O21(CH3COO)3]·6H2O (II) were synthesized and structurally characterized by scanning electron microscopy (SEM), elemental analyses, FTIR, UV spectroscopy, thermal stability analysis, XRD and single crystal X-ray diffraction. Crystal data: (I) triclinic system, space group P-1, a = 11,217 (9) Å, b = 11,637 (8) Å, c = 14,919 (8) Å, α = 70,90 (5)°, β = 70,83 (2)°, γ = 62,00(1)° and Z = 1; (II) triclinic system, space group P-1, a = 10.6740(1) Å, b = 10.6740(1) Å, c = 20.0570(1) Å, α = 76.285(1)°, β = 82.198(2)°, γ = 87.075(1)°, Z = 1. The crystal structure of (I) can be described by infinite polyanions [(HAsO4)2Mo6O18]4- organized with water molecules in layers parallel to the c-direction; adjacent layers are further joined up by hydrogen bonding interactions with organic groups which were associated in chains spreading along the b-direction. The structure of (II) consists of functionalized selenomolybdate clusters [SeMo6O21(CH3COO)3]5-, protonated imidazole cations, sodium ions and lattice water molecules, which are held together to generate a three-dimensional supramolecular network via hydrogen-bonding interaction. Furthermore, the electrochemical properties of these compounds have been studied.

A new ent-clerodane diterpenoid from Crassocephalum bauchiense Huch. (Asteraceae).

PubMed

Tchinda, Alembert T; Mouokeu, Simplice R; Ngono, Rosalie A N; Ebelle, Madeleine R E; Mokale, Aristide L K; Nono, Diane K; Frédérich, Michel

2015-01-01

A phytochemical investigation of the whole plant of Crassocephalum bauchiense Huch. resulted in the isolation of a new clerodane diterpenoid, ent-2β,18,19-trihydroxycleroda-3,13-dien-16,15-olide (1), together with two known flavonoids 3',5-dihydroxy-4',5',6,7,8-pentamethoxyflavone (2) and 4',5-dihydroxy-3',5',6,7,8-pentamethoxyflavone (3). The compounds were tested against the chloroquine-sensitive 3D7 strain of Plasmodium falciparum. Compound 2 showed weak activity (IC50 = 10.1 g/mL) whilst compounds 1 and 3 were inactive. The structures of the compounds were elucidated by using detailed spectral analyses, especially (1)H and (13)C NMR, (1)H-(1)H COSY, NOESY, HMBC and HR-ESI-MS.

Energy and Biocides Storage Compounds: Synthesis and Characterization of Energetic Bridged Bis(triiodoazoles).

PubMed

He, Chunlin; Zhao, Gang; Hooper, Joseph P; Shreeve, Jean'ne M

2017-11-06

Energetic bridged triiodopyrazoles and triiodoimidazoles were designed and synthsized by reacting potassium triiodopyrazolate or triiodoimidazolate with corresponding dichloro compounds. All compounds were fully characterized by 1 H and 13 C NMR spectroscopy, IR spectroscopy, and elemental analyses. The structure of compound 1 was further confirmed by single-crystal X-ray diffraction. All of the compounds exhibit good thermal stability with decomposition temperatures between 199 and 270 °C and high densities ranging from 2.804 to 3.358 g/cm 3 . The detonation performances and the detonation products were calculated by CHEETAH 7. Compound 3 (D v = 4765 m s -1 ; P = 17.9 GPa) and compound 7 (D v = 4841 m s -1 ; P = 18.5 GPa) show comparable detonation pressure to TNT, and high iodine content makes them promising as energy and biocides storage compounds.

The rationale for the optimum efficiency of columns packed with new 1.9μm fully porous Titan-C18 particles-a detailed investigation of the intra-particle diffusivity.

PubMed

Gritti, Fabrice; Guiochon, Georges

2014-08-15

In a previous report, it was reported that columns packed with fully porous 1.9μm Titan-C18 particles provided a minimum reduced plate height as small as 1.7 for the most retained compound (n-octanophenone) under RPLC conditions. These particles are characterized by a relatively narrow size distribution with a relative standard deviation (RSD) of only 10%. A column packed with classical 5μm Symmetry-C18 particles, used as a reference RPLC column, generated a minimum reduced plate height of 2.1 for the same retained compound. This work demonstrates that this was due to an unusually low intra-particle diffusivity across these particles, which leads to a small longitudinal diffusion coefficient along the column. The demonstration is based on the combination of accurate measurements of the height equivalent to a theoretical plate (HETP), inverse size exclusion chromatography (ISEC), peak parking (PP), and minor disturbance method (MDM) experiments. The experimental results show that the reduced eddy dispersion HETP term (A=0.8 for a reduced velocity of 5), the internal particle porosity (ϵp=0.35), and the enrichment of acetonitrile in the pore volume (75% acetonitrile in the bulk, 85% inside the mesoporous volume) are identical on both the Titan-C18 and Symmetry-C18 columns. The difference between the internal structures of these two brands of RPLC-C18 fully porous particles lies in the values of the internal obstruction factor γp, which is 0.42 for the Symmetry-C18 but only 0.26 for the Titan-C18 particles. This is in part related to the diffusion hindrance due to the small average pore size of the Titan-C18 particles, around 59Å versus 77Å for Symmetry-C18 particles. A simple model of constriction along diffusion paths having the shape of a truncated cone suggests that the width of the pore size distribution (RSD of 30% and 20% for Titan-C18 and Symmetry-C18 particles) is mostly responsible for the difference in their obstruction factors. Copyright © 2014 Elsevier B.V. All rights reserved.

Three closely related 4,5,6,7-tetrahydro-1H-pyrazolo[4,3-c]pyridines: synthesis, molecular conformations and hydrogen bonding in zero, one and two dimensions.

PubMed

Sagar, Belakavadi K; Harsha, Kachigere B; Yathirajan, Hemmige S; Rangappa, Kanchugarakoppal S; Rathore, Ravindranath S; Glidewell, Christopher

2017-03-01

In each of 1-(4-fluorophenyl)-5-methylsulfonyl-3-[4-(trifluoromethyl)phenyl]-4,5,6,7-tetrahydro-1H-pyrazolo[4,3-c]pyridine, C 21 H 19 F 4 N 3 O 2 S, (I), 1-(4-chlorophenyl)-5-methylsulfonyl-3-[4-(trifluoromethyl)phenyl]-4,5,6,7-tetrahydro-1H-pyrazolo[4,3-c]pyridine, C 21 H 19 ClF 3 N 3 O 2 S, (II), and 1-(3-methylphenyl)-5-methylsulfonyl-3-[4-(trifluoromethyl)phenyl]-4,5,6,7-tetrahydro-1H-pyrazolo[4,3-c]pyridine, C 22 H 22 F 3 N 3 O 2 S, (III), the reduced pyridine ring adopts a half-chair conformation with the methylsulfonyl substituent occupying an equatorial site. Although compounds (I) and (II) are not isostructural, having the space groups Pbca and P2 1 2 1 2 1 , respectively, their molecular conformations are very similar, but the conformation of compound (III) differs from those of (I) and (II) in the relative orientation of the N-benzyl and methylsulfonyl substituents. In compounds (II) and (III), but not in (I), the trifluoromethyl groups are disordered over two sets of atomic sites. Molecules of (I) are linked into centrosymmetric dimers by C-H...π(arene) hydrogen bonds, molecules of (II) are linked by two C-H...O hydrogen bonds to form ribbons of R 3 3 (18) rings, which are themselves further linked by a C-Cl...π(arene) interaction, and a combination of C-H...O and C-H...π(arene) hydrogen bonds links the molecules of (III) into sheets. Comparisons are made with the structures of some related compounds.

Synthesis, docking study and neuroprotective effects of some novel pyrano[3,2-c]chromene derivatives bearing morpholine/phenylpiperazine moiety.

PubMed

Sameem, Bilqees; Saeedi, Mina; Mahdavi, Mohammad; Nadri, Hamid; Moghadam, Farshad Homayouni; Edraki, Najmeh; Khan, Muhammad Imran; Amini, Mohsen

2017-08-01

Novel pyrano[3,2-c]chromene derivatives bearing morpholine/phenylpiperazine moiety were synthesized and evaluated against acetylcholinestrase (AChE) and butylcholinestrase (BuChE). Among the synthesized compounds, N-(3-cyano-4-(4-methoxyphenyl)-5-oxo-4,5-dihydropyrano[3,2-c]chromen-2-yl)-2-(4-phenylpiperazin-1-yl)acetamide (6c) exhibited the highest acetylcholinestrase inhibitory (AChEI) activity (IC 50 =1.12µM) and most of them showed moderate butylcholinestrase inhibitory activity (BChEI). Kinetic study of compound 6c confirmed mixed type of inhibition towards AChE which was in covenant with the results obtained from docking study. Also, it was evaluated against β-secretase which demonstrated low activity (inhibition percentage: 18%). It should be noted that compounds 6c, 7b, 6g, and 7d showed significant neuroprotective effects against H 2 O 2 -induced PC12 oxidative stress. Copyright © 2017 Elsevier Ltd. All rights reserved.

Relationships for the impact sensitivities of energetic C-nitro compounds based on bond dissociation energy.

PubMed

Li, Jinshan

2010-02-18

The ZPE-corrected C-NO(2) bond dissociation energies (BDEs(ZPE)) of a series of model C-nitro compounds and 26 energetic C-nitro compounds have been calculated using density functional theory methods. Computed results show that for C-nitro compounds the UB3LYP calculated BDE(ZPE) is less than the UB3P86 using the 6-31G** basis set, and the UB3P86 BDE(ZPE) changes slightly with the basis set varying from 6-31G** to 6-31++G**. For the series of model C-nitro compounds with different chemical skeletons, it is drawn from NBO analysis that the order of BDE(ZPE) is not only in line with that of the NAO bond order but also with that of the energy gap between C-NO(2) bonding and antibonding orbitals. It is found that for the energetic C-nitro compounds whose drop energies (Es(dr)) are below 24.5 J a good linear correlation exists between E(dr) and BDE(ZPE), implying that these compounds ignite through the C-NO(2) dissociation mechanism. After excluding the so-called trinitrotoluene mechanism compounds, a polynomial correlation of ln(E(dr)) with the BDE(ZPE) calculated at density functional theory levels has been established successfully for the 18 C-NO(2) dissociation energetic C-nitro compounds.

In vitro inhibition of the bovine viral diarrhoea virus by the essential oil of Ocimum basilicum (basil) and monoterpenes.

PubMed

Kubiça, Thaís F; Alves, Sydney H; Weiblen, Rudi; Lovato, Luciane T

2014-01-01

The bovine viral diarrhoea virus (BVDV) is suggested as a model for antiviral studies of the hepatitis C virus (HCV). The antiviral activity of the essential oil of Ocimum basilicum and the monoterpenes camphor, thymol and 1,8-cineole against BVDV was investigated. The cytotoxicities of the compounds were measured by the MTT (3-(4.5-dimethylthiazol-2-yl)-2.5-diphenyltetrazolium bromide) test, and the antiviral activities were tested by the plaque reduction assay. The oil or compounds were added to the assay in three different time points: a) pre-treatment of the virus (virucidal assay); b) pre-treatment of the cells; or c) post-treatment of the cells (after virus inoculation). The percentage of plaques inhibition for each compound was determined based on the number of plaques in the viral control. The results were expressed by CC50 (50% cytotoxic concentration), IC50 (inhibitory concentration for 50% of plaques) and SI (selectivity index = CC50/IC50). Camphor (CC50 = 4420.12 μg mL(-1)) and 1,8-cineole (CC50 = 2996.10 μg mL(-1)) showed the lowest cytotoxicities and the best antiviral activities (camphor SI = 13.88 and 1,8-cineol SI = 9.05) in the virucidal assay. The higher activities achieved by the monoterpenes in the virucidal assay suggest that these compounds act directly on the viral particle.

Enhanced organic memory devices (OMEM) with a photochromic perhydro DTE as a transduction layer (Conference Presentation)

NASA Astrophysics Data System (ADS)

Cordes, Sandra; Kranz, Darius; Maibach, Eduard; Kempf, Maxim; Meerholz, Klaus

2016-09-01

In modern electronic systems memory elements are of fundamental importance for data storage. Especially solution-processable nonvolatile organic memories, which are inexpensive and can be manufactured on flexible substrates, are a promising alternative to brittle inorganic devices. Organic photochromic switchable compounds, mostly dithienylethenes (DTEs), are thermally stable, fatigue resistant and can undergo an electrically- or/and photo-induced ring-opening and -closing reaction which results in a change of energy levels. Due to the energetic difference in the highest occupied molecular orbital (HOMO) between the open and closed isomer, the DTE layer can be exploited as a switchable hole injection barrier that controls the electrical current in the diode. We demonstrated that a light-emitting organic memory (LE-OMEM) device with a perfluoro DTE transduction layer can be switched electrically via high current densities pulses and optically by irradiated light, with impressive current ON/OFF Ratios (OOR) of 10Λ2, 10Λ4 respectively. Currently we aim to minimize the barrier of the ON state and maximize the barrier of the OFF state by designing DTE molecules with larger differences in the HOMO energies of the two isomers yielding improved OOR values. By synthesizing perhydro derivates of DTE we achieved molecules with high HOMO levels and large ΔHOMO energies providing OMEM devices with excellent physical properties (OOR 1.4 x higher than perfluoro DTE). Due to the high HOMO level of the perhydro DTE utilization of hole transport layers (HTLs) is not necessary and thus manufacturing of OMEM devices is simplified.

Impact of feeding and short-term temperature stress on the content and isotopic signature of fatty acids, sterols, and alcohols in the scleractinian coral Turbinaria reniformis

NASA Astrophysics Data System (ADS)

Tolosa, I.; Treignier, C.; Grover, R.; Ferrier-Pagès, C.

2011-09-01

This study assesses the combined effect of feeding and short-term thermal stress on various physiological parameters and on the fatty acid, sterol, and alcohol composition of the scleractinian coral Turbinaria reniformis. The compound-specific carbon isotope composition of the lipids was also measured. Under control conditions (26°C), feeding with Artemia salina significantly increased the symbiont density and chlorophyll content and the growth rates of the corals. It also doubled the concentrations of almost all fatty acid (FA) compounds and increased the n-alcohol and sterol contents. δ13C results showed that the feeding enhancement of FA concentrations occurred either via a direct pathway, for one of the major polyunsaturated fatty acid (PUFA) compounds of the food (18:3n-3 FA), or via an enhancement of photosynthate transfer (indirect pathway), for the other coral FAs. Cholesterol (C27Δ5) was also directly acquired from the food. Thermal stress (31°C) affected corals, but differently according to their feeding status. Chlorophyll, protein content, and maximal photosynthetic efficiency of photosystem II (PSII) decreased to a greater extent in starved corals. In such corals, FA concentrations were reduced by 33%, (especially C16, C18 FAs, and n-3 PUFA) and the sterol content by 27% (especially the C28∆5,22 and C28∆5). The enrichment in the δ13C signature of the storage and structural FAs suggests that they were the main compounds respired during the stress to maintain the coral metabolism. Thermal stress had less effect on the lipid concentrations of fed corals, as only FA levels were reduced by 13%, with no major changes in their isotope carbon signatures. In conclusion, feeding plays an essential role in sustaining T. reniformis metabolism during the thermal stress.

[The compounds from n-butanol fraction of Alpinia oxyphylla].

PubMed

Xie, Bin-Bin; Hou, Lei; Guo, Bao-Lin; Huang, Wen-Hua; Yu, Jing-Guang

2014-11-01

Nine compounds were isolated from the n-butanol fraction of 95% ethanol extract of the fruit of Alpinia oxyphylla Miq. with a combination of various chromatographic approaches, including MDS resin, silica gel, reverse phase C18 and preparative HPLC. On the basis of spectroscopic data analysis, they were elucidated as (1R, 4R, 10R)-1β, 4α-dihydroxy-11, 12, 13-trinor-5, 6-eudesmen-7-one (1), 1β, 4β-dihydroxy-11, 12, 13-trinor-8, 9-eudesmen-7-one (2), oxyphyllenone A (3), oxyphyllenone B (4), rhamnocitrin (5), staphylionoside D (6), benzyl-1-O-β-D-glucopyranoside (7), 2-O-β-D-glucopyranosyl-(1S)-phenylethylene glycol (8), and (S)-1-phenylethyl-β-D-glucopyranoside (9). Among them, compound 1 is a new sesquiterpene, named as oxyphyllenone C; compounds 8 and 9 are new natural products; compounds 2 and 6 were isolated from the genus Alpinia for the first time, and compound 7 was isolated from A. oxyphylla for the first time.

Perfluoroalkyl sulfonates and carboxylic acids in liver, muscle and adipose tissues of black-footed albatross (Phoebastria nigripes) from Midway Island, North Pacific Ocean.

PubMed

Chu, Shaogang; Wang, Jun; Leong, Gladys; Woodward, Lee Ann; Letcher, Robert J; Li, Qing X

2015-11-01

The Great Pacific Garbage Patch (GPGP) is a gyre of marine plastic debris in the North Pacific Ocean, and nearby is Midway Atoll which is a focal point for ecological damage. This study investigated 13 C4-C16 perfluorinated carboxylic acids (PFCAs), four (C4, C6, C8 and C10) perfluorinated sulfonates and perfluoro-4-ethylcyclohexane sulfonate [collectively perfluoroalkyl acids (PFAAs)] in black-footed albatross tissues (collected in 2011) from Midway Atoll. Of the 18 PFCAs and PFSAs monitored, most were detectable in the liver, muscle and adipose tissues. The concentrations of PFCAs and PFSAs were higher than those in most seabirds from the arctic environment, but lower than those in most of fish-eating water birds collected in the U.S. mainland. The concentrations of the PFAAs in the albatross livers were 7-fold higher than those in Laysan albatross liver samples from the same location reported in 1994. The concentration ranges of PFOS were 22.91-70.48, 3.01-6.59 and 0.53-8.35 ng g(-1) wet weight (ww), respectively, in the liver, muscle and adipose. In the liver samples PFOS was dominant, followed by longer chain PFUdA (8.04-18.70 ng g(-1) ww), PFTrDA, and then PFNA, PFDA and PFDoA. Short chain PFBA, PFPeA, PFBS and PFODA were below limit of quantification. C8-C13 PFCAs showed much higher composition compared to those found in other wildlife where PFOS typically predominated. The concentrations of PFUdA in all 8 individual albatross muscle samples were even higher than those of PFOS. This phenomenon may be attributable to GPGP as a pollution source as well as PFAA physicochemical properties. Copyright © 2015 Elsevier Ltd. All rights reserved.

[Chemical Constituents from Leaves of "Chuju" Chrysanthemum morifolium and Their Antioxidant Activities in vitro].

PubMed

Wei, Qiang; Ji, Xiao-ying; Long, Xian-shun; Li, Qian-rong; Yin, Hao

2015-02-01

To study the chemical constituents from the leaves of "Chuju" Chrysanthemum morifolium. All compounds were separated and purified by column chromatography over silica gel, Sephadex LH-20 and preparative HPLC. Their structures were identified by spectral methods including 1H-NMR and 13C-NMR. 21 compounds were isolated and identified as octa-cosyl alcohol (1), β-sitosterol (2), lupeol (3), α-amyrin (4), daucosterol (5), ineupatorolide B (6), syringin (7), chlorogenic acid (8), petasiphenol (9), physcion (10), acacetin (11), eupatilin (12), quercetin (13), diosmetin (14), luteolin (15), apigenin (16), apigenin- 7-O-β-D-glucopyranoside (17), quercetin-3-O-β-D-glucopyranoside (18), luteolin-7-O-β-D-gluco pyranoside (19), apigenin-7-O-β-D- neospheroside (20), and acacetin-7-O-β-D-glucoside (21). Compounds 1-12, 18 and 20 are isolated from this plant for the first time. Compounds 10, 13, 14, 15 and 16 have shown strong antioxidant activities by DPPH · scavenging activity better than Vit C.

Determination of pterins in urine by HPLC with UV and fluorescent detection using different types of chromatographic stationary phases (HILIC, RP C8, RP C18).

PubMed

Kośliński, Piotr; Jarzemski, Piotr; Markuszewski, Michał J; Kaliszan, Roman

2014-03-01

Pterins are a class of potential cancer biomarkers. New methods involving hydrophilic interaction liquid chromatography (HILIC) and reversed phase (RP) high-performance liquid chromatography have been developed for analysis of eight pterin compounds: 6,7-dimethylpterin, pterin, 6-OH-methylpterin, biopterin, isoxanthopterin, neopterin, xanthopterin, and pterin-6-carboxylic acid. The effect of mobile phase composition, buffer type, pH and concentration on retention using HILIC, C8 and C18 RP stationary phases were examined. Separation of pterins on RP and HILIC stationary phase was performed and optimized. Eight pterins were successfully separated on HILIC Luna diol-bonded phases, Aquasil C18 RP column and LiChrospher C8 RP column. Determination and separation of the pterins from urine samples were performed on HILIC Luna and LiChrospher C8 RP columns which were chosen as the most appropriate ones. Finally, LiChrospher C8 RP column with fluorescence detection was selected for further validation of the method. The optimum chromatographic condition was mobile phase methanol (A)/phosphoric buffer pH 7, 10mM (B), isocratic elution 0-15min 5% A flow=0.5ml/min 15-17min. 5% A, flow=0.5-1ml/min the linearity (R(2)>0.997) and retention time repeatability (RSD%<1) were at satisfactory level. The precision of peak areas expressed as RSD in % was between 0.55 and 14. Pterins detection limits varied from 0.041ng/ml to 2.9ng/ml. Finally, HPLC method was used for the analysis of pterins in urine samples with two different oxidation procedures. Concentration levels of pterin compounds in bladder cancer patients and healthy subjects were compared. Copyright © 2013 Elsevier B.V. All rights reserved.

Beltsville poultry semen extender. 9. Effect of storage temperature on turkey semen held eighteen hours.

PubMed

Giesen, A F; Sexton, T J

1983-07-01

Turkey semen was collected, diluted 1:1 with Beltsville Poultry Semen Extender, and held for 0 or 18 hr at 5, 15, 25, or 35 C. Changes in spermatozoa motility and sperm numbers were monitored before and after holding. All hens were artificially inseminated (AI) with 250 X 10(6) spermatozoa three times the first week and once weekly thereafter for a total of 20 weeks. No significant differences were observed in candling fertility (85 vs. 82%) of hens AI with unstored semen or semen held at 5 C for 18 hr. Significant depression of fertility levels to 41 and 40% were noted in hens AI with semen stored at 15 and 25 C, respectively. No fertile eggs were obtained from hens AI with semen held at 35 C for 18 hr. Sperm motility scores were not different between the unstored controls and samples held at 5 C (62 vs. 64%). Samples held at 15 and 25 C had motility scores of 40 and 8%, respectively. Samples held at 35 C for 18 hr were immotile. As semen holding temperature increased from 5 to 35 C, sperm numbers decreased during the 18 hr holding period by 11, 16, 28, and 45% of the unstored control. The decrease in sperm numbers during the 18-hr holding period was speculated to be the result of sperm aging which was compounded by sample agitation during storage. The methodology used for determining sperm numbers did not adversely influence the results.

Stability of Sodium Nitroprusside in 5% Dextrose Stored at 4°C in Polypropylene Syringes Protected from Light.

PubMed

Anderson, Collin R; Collins, Deborah; Laursen, Trevor; Arave, Trevor; Helm, Michael

2016-01-01

Sodium nitroprusside is a potent vasodilator employed intraoperatively and within critical care areas. The photolabile pharmaceutical agent has been used for decades and various stability studies have been executed. Due to potential shortages and the desire to batch compound sodium nitroprusside at a concentration of 1 mg/mL in polypropylene syringes, a new stability study was performed. Chromatographic analysis was conducted on a C18 column, with elution via an aqueous phase of 0.01 M sodium phosphate monobasic, adjusted to pH 6.5 with sodium hydroxide, and methanol (97.5:2.5) at a rate of 1 mL/min, and subsequent ultraviolet detection at 210 nm. Triplicate determinations of four samples, stored under refrigeration at 4°C, were obtained initially and on days 2, 5, and 9. Turbidity and pH measurements were performed in conjunction with visual observation on days of chromatographic analysis. Results demonstrate that sodium nitroprusside compounded in 5% dextrose at a concentration of 1 mg/mL, stored at 4°C protected from light in polypropylene syringes, is physically and chemically stable for at least 9 days. Copyright© by International Journal of Pharmaceutical Compounding, Inc.

A series of (E)-5-(arylideneamino)-1-tert-butyl-1H-pyrrole-3-carbonitriles and their reduction products to secondary amines: syntheses and X-ray structural studies.

PubMed

Macías, Mario A; Castillo, Juan Carlos; Portilla, Jaime

2018-01-01

An efficent access to a series of N-(pyrrol-2-yl)amines, namely (E)-1-tert-butyl-5-[(4-chlorobenzylidene)amino]-1H-pyrrole-3-carbonitrile, C 16 H 16 ClN 3 , (7a), (E)-1-tert-butyl-5-[(2,4-dichlorobenzylidene)amino]-1H-pyrrole-3-carbonitrile, C 16 H 15 Cl 2 N 3 , (7b), (E)-1-tert-butyl-5-[(pyridin-4-ylmethylene)amino]-1H-pyrrole-3-carbonitrile, C 15 H 16 N 4 , (7c), 1-tert-butyl-5-[(4-chlorobenzyl)amino]-1H-pyrrole-3-carbonitrile, C 16 H 18 ClN 3 , (8a), and 1-tert-butyl-5-[(2,4-dichlorobenzyl)amino]-1H-pyrrole-3-carbonitrile, C 16 H 17 Cl 2 N 3 , (8b), by a two-step synthesis sequence (solvent-free condensation and reduction) starting from 5-amino-1-tert-butyl-1H-pyrrole-3-carbonitrile is described. The syntheses proceed via isolated N-(pyrrol-2-yl)imines, which are also key synthetic intermediates of other valuable compounds. The crystal structures of the reduced compounds showed a reduction in the symmetry compared with the corresponding precursors, viz. Pbcm to P-1 from compound (7a) to (8a) and P2 1 /c to P-1 from compound (7b) to (8b), probably due to a severe change in the molecular conformations, resulting in the loss of planarity observed in the nonreduced compounds. In all of the crystals, the supramolecular assembly is controlled mainly by strong (N,C)-H...N hydrogen bonds. However, in the case of (7a)-(7c), C-H...Cl interactions are strong enough to help in the three-dimensional architecture, as observed in Hirshfeld surface maps.

Alkaloids from the leaves of Uncaria rhynchophylla and their inhibitory activity on NO production in lipopolysaccharide-activated microglia.

PubMed

Yuan, Dan; Ma, Bin; Wu, Chunfu; Yang, Jingyu; Zhang, Lijia; Liu, Suiku; Wu, Lijun; Kano, Yoshihiro

2008-07-01

Two new isomeric alkaloids, 18,19-dehydrocorynoxinic acid B (1) and 18,19-dehydrocorynoxinic acid (2), were isolated from the CHCl3 extract of the leaves of Uncaria rhynchophylla, together with four known rhynchophylline-type alkaloids, corynoxeine (3), isocorynoxeine (4), rhynchophylline (5), and isorhynchophylline (6), and an indole alkaloid glucoside, vincoside lactam (7). The structures of compounds 1 and 2 were elucidated by spectroscopic methods including UV, IR, HREIMS, 1D and 2D NMR, and CD experiments. The activity assay showed that compounds 3-6, with a C-16 carboxylic ester group, and 7 exhibited inhibitory activity on lipopolysaccharide (LPS)-induced NO release in primary cultured rat cortical microglia (IC 50: 13.7-19.0 microM). However, only weak inhibitory activity was observed for compounds 1 and 2, with a C-16 carboxylic acid group (IC 50: >100 microM).

Biodegradation of diesel fuel by a microbial consortium in the presence of 1-alkoxymethyl-2-methyl-5-hydroxypyridinium chloride homologues.

PubMed

Chrzanowski, Lukasz; Stasiewicz, Monika; Owsianiak, Mikołaj; Szulc, Alicja; Piotrowska-Cyplik, Agnieszka; Olejnik-Schmidt, Agnieszka K; Wyrwas, Bogdan

2009-09-01

Fast development of ionic liquids as gaining more and more attention valuable chemicals will undoubtedly lead to environmental pollution. New formulations and application of ionic liquids may result in contamination in the presence of hydrophobic compounds, such as petroleum mixtures. We hypothesize that in the presence of diesel fuel low-water-soluble ionic liquids may become more toxic to hydrocarbon-degrading microorganisms. In this study the influence of 1-alkoxymethyl-2-methyl-5-hydroxypyridinium chloride homologues (side-chain length from C(3) to C(18)) on biodegradation of diesel fuel by a bacterial consortium was investigated. Whereas test performed for the consortium cultivated on disodium succinate showed that toxicity of the investigated ionic liquids decreased with increase in side-chain length, only higher homologues (C(8)-C(18)) caused a decrease in diesel fuel biodegradation. As a result of exposure to toxic compounds also modification in cell surface hydrophobicity was observed (MATH). Disulphine blue active substances method was employed to determine partitioning index of ionic liquids between water and diesel fuel phase, which varied from 1.1 to 51% for C(3) and C(18) homologues, respectively. We conclude that in the presence of hydrocarbons acting as a solvent, the increased bioavailability of hydrophobic homologues is responsible for the decrease in biodegradation efficiency of diesel fuel.

Blood monitoring of perfluorocarbon compounds (F-tert-butylcyclohexane, perfluoromethyldecalin and perfluorodecalin) by headspace-gas chromatography-tandem mass spectrometry.

PubMed

Giuliani, N; Saugy, M; Augsburger, M; Varlet, V

2015-11-01

A headspace-gas chromatography-tandem mass spectrometry (HS-GC-MS/MS) method for the trace measurement of perfluorocarbon compounds (PFCs) in blood was developed. Due to oxygen carrying capabilities of PFCs, application to doping and sports misuse is speculated. This study was therefore extended to perform validation methods for F-tert-butylcyclohexane (Oxycyte(®)), perfluoro(methyldecalin) (PFMD) and perfluorodecalin (PFD). The limit of detection of these compounds was established and found to be 1.2 µg/mL blood for F-tert-butylcyclohexane, 4.9 µg/mL blood for PFMD and 9.6 µg/mL blood for PFD. The limit of quantification was assumed to be 12 µg/mL blood (F-tert-butylcyclohexane), 48 µg/mL blood (PFMD) and 96 µg/mL blood (PFD). HS-GC-MS/MS technique allows detection from 1000 to 10,000 times lower than the estimated required dose to ensure a biological effect for the investigated PFCs. Thus, this technique could be used to identify a PFC misuse several hours, maybe days, after the injection or the sporting event. Clinical trials with those compounds are still required to evaluate the validation parameters with the calculated estimations. Copyright © 2015 Elsevier B.V. All rights reserved.

Expansion of antimonato polyoxovanadates with transition metal complexes: (Co(N3C5H15)2)2[{Co(N3C5H15)2}V15Sb6O42(H2O)]·5H2O and (Ni(N3C5H15)2)2[{Ni(N3C5H15)2}V15Sb6O42(H2O)]·8H2O.

PubMed

Antonova, Elena; Näther, Christian; Kögerler, Paul; Bensch, Wolfgang

2012-02-20

Two new polyoxovanadates (Co(N(3)C(5)H(15))(2))(2)[{Co(N(3)C(5)H(15))(2)}V(15)Sb(6)O(42)(H(2)O)]·5H(2)O (1) and (Ni(N(3)C(5)H(15))(2))(2)[{Ni(N(3)C(5)H(15))(2)}V(15)Sb(6)O(42)(H(2)O)]·8H(2)O (2) (N(3)C(5)H(15) = N-(2-aminoethyl)-1,3-propanediamine) were synthesized under solvothermal conditions and structurally characterized. In both structures the [V(15)Sb(6)O(42)(H(2)O)](6-) shell displays the main structural motif, which is strongly related to the {V(18)O(42)} archetype cluster. Both compounds crystallize in the triclinic space group P1 with a = 14.3438(4), b = 16.6471(6), c = 18.9186(6) Å, α = 87.291(3)°, β = 83.340(3)°, γ = 78.890(3)°, and V = 4401.4(2) Å(3) (1) and a = 14.5697(13), b = 15.8523(16), c = 20.2411(18) Å, α = 86.702(11)°, β = 84.957(11)°, γ = 76.941(11)°, and V = 4533.0(7) Å(3) (2). In the structure of 1 the [V(15)Sb(6)O(42)(H(2)O)](6-) cluster anion is bound to a [Co(N(3)C(5)H(15))(2)](2+) complex via a terminal oxygen atom. In the Co(2+)-centered complex, one of the amine ligands coordinates in tridentate mode and the second one in bidentate mode to form a strongly distorted CoN(5)O octahedron. Similarly, in compound 2 an analogous NiN(5)O complex is joined to the [V(15)Sb(6)O(42)(H(2)O)](6-) anion via the same attachment mode. A remarkable difference between the two compounds is the orientation of the noncoordinated propylamine group leading to intermolecular Sb···O contacts in 1 and to Sb···N interactions in 2. In the solid-state lattices of 1 and 2, two additional [M(N(3)C(5)H(15))(2)](2+) complexes act as countercations and are located between the [{M(N(3)C(5)H(15))(2)}V(15)Sb(6)O(42)(H(2)O)](4-) anions. Between the anions and cations strong N-H···O hydrogen bonds are observed. In both compounds the clusters are stacked along the b axis in an ABAB fashion with cations and water molecules occupying the space between the clusters. Magnetic characterization demonstrates that the Ni(2+) and Co(2+) cations do not significantly couple with the S = 1/2 vanadyl groups. The susceptibility data can be successfully reproduced assuming a distorted ligand field for the Co(2+) ions (1) and an O(h)-symmetric Ni(2+) ligand field (2).

Friedelane-type triterpenoids as selective anti-inflammatory agents by regulation of differential signaling pathways in LPS-stimulated macrophages

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

Villar-Lorenzo, Andrea, E-mail: avillar@iib.uam.es

A series of 31 pentacyclic triterpenoids isolated from the root barks of Celastrus vulcanicola and Maytenus jelskii were tested for cytotoxicity and inhibitory activity against lipopolysaccharide (LPS)-induced nitric oxide (NO) production in RAW 264.7 macrophages. Compounds 18 (C18) and 25 (C25) exhibited significant inhibition of LPS-induced NO release at 50 and 25 μM concentrations, respectively, and decreased mRNAs of pro-inflammatory cytokines. At the molecular level, C18 neither inhibited LPS-mediated phosphorylation of mitogen activated protein kinases (MAPKs) nor nuclear translocation of nuclear factor kappa beta (NFκB). Instead, C18 enhanced and prolonged nuclear translocation of nuclear factor-erythroid 2-related factor 2 (Nrf2) andmore » increased the expression of its target genes including hemeoxigenase 1 (HO1). C25 efficiently inhibited LPS-mediated phosphorylation of JNK, p38 and ERK, without affecting NFκB or Nrf2 signaling pathways. Both compounds reduced LPS-mediated processing of caspase-1 and the cleavage of interleukin 1β (IL1β) proform, reflecting their ability to target the inflammasome. C25 also counteracted LPS effects on iNOS expression and pro-inflammatory cytokines mRNA levels in Bv-2 microglial cells. The anti-inflammatory effect of both compounds was also assessed in human macrophages. Our results suggest that triterpenoids C18 and C25 possess anti-inflammatory effects, which may be therapeutically relevant for diseases linked to inflammation. - Highlights: • Compounds 18 (C18) and 25 (C25) exert anti-inflammatory effects in macrophages. • C18 enhanced nuclear translocation of Nrf2 and increased HO1 expression. • C25 inhibited the phosphorylation of JNK, p38 and ERK, members of the MAPKs family. • C25 reduced LPS-mediated processing of caspase-1 and the cleavage of interleukin 1β. • C18 and C25 may be therapeutic agents for diseases linked to inflammation.« less

A mid-infrared sensor for the determination of perfluorocarbon-based compounds in aquatic systems for geosequestration purposes.

PubMed

Rauh, Florian; Schwenk, Matthias; Pejcic, Bobby; Myers, Matthew; Ho, Koon-Bay; Stalker, Linda; Mizaikoff, Boris

2014-12-01

Perfluorocarbon (PFC) compounds have been used as chemical tracer molecules to understand the movement of supercritical carbon dioxide for geosequestration monitoring and verification purposes. A commonly used method for detecting PFCs involves the collection of a sample from either soil-gas or the atmosphere via carbon-based sorbents which are then analyzed in a laboratory. However, PFC analysis in aquatic environments is neglected and this is an issue that needs to be considered since the PFC is likely to undergo permeation through the overlying water formations. This paper presents for the first time an innovative analytical method for the trace level in situ detection of PFCs in water. It reports on the development of a sensor based on mid-infrared attenuated total reflection (MIR-ATR) spectroscopy for determining the concentration of perfluoromethylcyclohexane (PMCH) and perfluoro-1,3-dimethylcyclohexane (PDCH) in aquatic systems. The sensor comprises a zinc selenide waveguide with the surface modified by a thin polymer film. The sensitivity of this device was investigated as a function of polymer type, coating thickness, and solution flow rates. The limit of detection (LOD) was determined to be 23 ppb and 79 ppb for PMCH and PDCH, respectively when using a 5 μm thick polyisobutylene (PIB) coated waveguide. This study has shown that the MIR-ATR sensor can be used to directly quantify PFC-based chemical tracer compounds in water over the 20-400 ppb concentration range. Crown Copyright © 2014. Published by Elsevier B.V. All rights reserved.

Synthesis, characterization, electrochemical investigation and antioxidant activities of a new hybrid cyclohexaphosphate: Cu1.5Li(C2H10N2)P6O18·7H2O

NASA Astrophysics Data System (ADS)

Sleymi, Samira; Lahbib, Karima; Rahmouni, Nihed; Rzaigui, Mohamed; Besbes-Hentati, Salma; Abid, Sonia

2017-09-01

A new organic-inorganic hybrid transition metal phosphate, Cu1.5Li(C2H10N2)P6O18·7H2O, has been prepared and characterized by X-ray diffraction, spectroscopy (infrared, Raman, diffuse reflectance and UV-Vis) and thermal analysis (TG). In addition, its electrochemical behaviors, as well as its antioxidant and antibacterial activities, have been investigated. Its structure is built up by the alternate linkages between copper and phosphate polyhedra, forming puckered layers with intersecting 12-membered rings, in which the ethylenediammonium cations reside. This compound is the first framework structure constructed from cyclohexaphosphates and three distinct copper cations. Cyclic voltammetry study in an acetonitrile solution reveals the facile anodic oxidation of its organic part on a platinum disk and a progressive growing of a thin film, though the repetitive cycling of potential. The title compound was tested for its in vitro antioxidant activities by 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2‧-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), Ferrous chelating ability (FIC) and Ferric Reducing Power (FRP) methods. The antioxidant activity of Cu1.5Li(C2H10N2)P6O18·7H2O was analyzed simultaneously with its antibacterial capacity against Escherichia coli, Salmonella typhimurium, Staphylococus aureus, Enterococcus feacium, Streptococcus agalactiae and Candida albicans. The tested compound showed significant antioxidant activities with low antibacterial properties.

Volatile organic compounds in the marine troposphere and surface oceans: methods, measurements and biogeochemical implications

NASA Astrophysics Data System (ADS)

Hudson, Edward

2010-09-01

Volatile organic compounds (VOCs), among them non-methane hydrocarbons (NMHCs) and low molecular weight carbonyl compounds (aldehydes and ketones), affect the oxidative capacity of the atmosphere and thus pollutant lifetimes and global climate. VOCs in the surface oceans may be transported into, or derived from, the atmosphere. This thesis describes the development and optimization of chromatographic and preconcentration methods to determine volatile organic compounds (VOCs) in surface seawater and marine air, and their use to explore VOC distribution and fluxes at the seaair interface. It includes the first measurements of many carbonyl compounds in temperate and subarctic marine waters and the first estimates of fluxes of several aldehydes from the ocean surface into the marine atmosphere. Sea surface air, size-fractionated marine aerosols, and surface ocean water dissolved organic matter were simultaneously sampled in the Nordic seas. Nineteen C2-C7 NMHCs were quantified in the air samples. Site-to-site variability in NMHC concentrations was high, suggesting variable, local sources. The aerosols consisted mainly of inorganic marine material, but a culturable bacterium identified as Micrococcus luteus was also isolated from the 9.9 -- 18 mum fraction, suggesting organic matter may be transferred from the surface oceans to the atmosphere by marine aerosols. Lastly, a number of VOCs, including acetone, were detected in the seawater samples using solid-phase microextraction (SPME), leading to the subsequent development of an SPME application for carbonyl compounds in seawater. A mobile, economical and solventless method for the detection and quantification of carbonyl compounds in seawater, a matrix of global importance, was developed. The compounds were derivatized using O-(2,3,4,5,6-pentafluorobenzyl)-hydroxylamine (PFBHA)and then pre-concentrated by SPME for gas chromatography with mass spectrometric (GC/MS) or flame ionization (GC-FID) detection. The method was first optimized for acetone and subsequently for a suite of 23 C1 -- C9 carbonyl compounds. The buffering capacity of seawater necessitated the use of artificial seawater for standard preparation, and acidification of seawater samples to achieve the method's optimum pH of 3.7. Sparging with UHP argon, and C-18 solid phase extraction of the dissolved PFBHA, were found to be the most effective methods for reducing the high process blanks observed for C1-C3 carbonyl compounds. Using this technique, the first acetone measurements for North Atlantic and Arctic waters (5.5 --9.6 nM acetone), the first surface water measurements of carbonyl compounds from the St. Lawrence Estuary (including glyoxal, methylglyoxal and 2,4-pentanedione), and concentrations of 11 C1 - C9 carbonyl compounds in surface seawaters from the Labrador Sea and from the Scotian Shelf were reported. This represents the first survey of these compounds in seawaters outside of the tropics. The results suggest that the North Atlantic is a sink for glyoxal and formaldehyde. Fluxes of several C4 - C9 aldehydes from the ocean to the atmosphere were estimated to be -13 to +14 mumol/m2/day.

Synthesis of some 1,8-dioxoacridine carboxylic acid derivatives and the determination of their ionization constants in ethanol-water mixtures

NASA Astrophysics Data System (ADS)

Saygılı, Rukiye; Ulus, Ramazan; Yeşildağ, İbrahim; Kübra İnal, E.; Kaya, Muharrem; Murat Kalfa, O.; Zeybek, Bülent

2015-03-01

Four novel compounds of 1,8-dioxoacridine carboxylic acid derivatives (4-(3,3,6,6-tetramethyl-1,8-dioxo-9-phenyl-1,2,3,4,5,6,7,8-octahydroacridin-10(9H)-yl)benzoic acid, 4-(9-(4-cyanophenyl)-3,3,6,6-tetramethyl-1,8-dioxo-1,2,3,4,5,6,7,8-octahydroacridin-10(9H)-yl)benzoic acid, 4-(9-(4-hydroxyphenyl)-3,3,6,6-tetramethyl-1,8-dioxo-1,2,3,4,5,6,7,8-octahydroacridin-10(9H)-yl)benzoic acid, 4-(9-(2,4-dichlorophenyl)-3,3,6,6-tetramethyl-1,8-dioxo-1,2,3,4,5,6,7,8-octahydroacridin-10(9H)-yl)benzoic acid) were prepared by the reaction of the 4-substitute benzaldehyde (hydrogen, hydroxyl, cyano, and 2,4-dichloro), 4-aminobenzoic acid, and 5,5-dimethylcyclohexane-1,3-dione in the presence of p-dodecylbenzenesulfonic acid. They were characterized by using FT-IR, 1H-NMR, 13C-NMR, GC-MS spectroscopic techniques. The stoichiometric ionization constants of these compounds were determined in ethanol-water mixtures of 50%, 60% and 70% ethanol (v/v) by potentiometric titration method and the ionization constants were calculated with three different ways. The effects of solvent composition and substituent groups on ionization constants of 1,8-dioxoacridine carboxylic acids were also discussed.

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

Gritti, Fabrice; Guiochon, Georges A

The adsorption isotherms of phenol, caffeine, propranolol chloride, and amitriptyline chloride were measured on three new brands of C{sub 18}-bonded silica that have been designed to be more resistant than conventional C{sub 18}-bonded silica at high pHs (>8). These columns were the 4 {micro}m Bidendate Cogent-C{sub 18} (Microsolv Technology Corporation, Long Branch, NJ, USA), the 3.5 {micro}m Zorbax Extend-C{sub 18} (Agilent Technologies, Palo Alto, CA, USA), and the 5 {micro}m XTerra-C{sub 18} (Waters, Milford, MA, USA). The originality of these adsorbents is due to their surface chemistry, which protects them from rapid hydrolysis or dissolution at extreme pH conditions. Theirmore » adsorption properties were compared to those of the 3 {micro}m Luna-C{sub 18} (Phenomenex, Torrance, CA), which is a more conventional monofunctional material. The adsorption data were acquired by frontal analysis (FA) and the adsorption energy distributions (AEDs) of all systems studied were calculated by the expectation-maximization (EM) method. The experimental results show that neither a simple surface protection (Extend-C{sub 18}) nor the elimination of most of the silanol groups (Cogent-C{sub 18}) is sufficient to avoid a peak tailing of the basic compounds at pH 8 that is of thermodynamic origin. The incorporation of organic moieties in the silica matrix, which was achieved in XTerra-C{sub 18}, the first generation of hybrid methyl/silica material, reduces the silanols activity and is more successful in reducing this peak tailing.« less

[Chemical constituents of Lepidium meyenii].

PubMed

Liang, Wen-juan; Xu, Hong-bo; Yang, Cai-yan; Geng, Chang-an; Zhang Xue-mei; Chen, Ji-jun

2015-12-01

To study the chemical constituents of Lepidium meyenii, the air-dried rhizome of L. meyenii was extracted with 70% EtOH. The extract was condensed to a small amount of volume and extracted with petroleum ether, EtOAc and n-BuOH, successively. The compounds were isolated and purified by column chromatography, and identified based on spectral analyses (1H-NMR, 13C-NMR, HRESIMS). Eighteen compounds were isolated from L. meyenii, including 7 alkaloids and 4 fatty acids and 7 other compounds. They were characterized as (3-hydroxybenzyl) carbamic acid(1), phenylmethanamine(2), N-benzylformamide (3), N-benzylacetamide (4), pyridin-4-ylmethanamine(5), n-(4-methoxybenzyl) aniline(6), uracil(7), succininc acid(8), decanedioic acid(9), n-hexa- decanoic acid methyl ester(10), heptanoic acid(11), solerole(12), pyromucic acid methyl ester(13), 5-hydroxymethyl-2-furancar- boxadehyde(14), 5-(methoxymethyl)-1H-pyrrole-2-carbaldehyde(15), 1,7-dihydroxy-2,3, 4-trimethoxyxanthone (16), 1,7-di- hydroxy-3,4- dimethoxy-xanthone(17), (+)-pinoresinol(18). Meanwhile, compounds 1-18 were obtained from L. neyenii for the first time.

Rational Design, Pharmacomodulation, and Synthesis of Dual 5-Hydroxytryptamine 7 (5-HT7)/5-Hydroxytryptamine 2A (5-HT2A) Receptor Antagonists and Evaluation by [(18)F]-PET Imaging in a Primate Brain.

PubMed

Deau, Emmanuel; Robin, Elodie; Voinea, Raluca; Percina, Nathalie; Satała, Grzegorz; Finaru, Adriana-Luminita; Chartier, Agnès; Tamagnan, Gilles; Alagille, David; Bojarski, Andrzej J; Morisset-Lopez, Séverine; Suzenet, Franck; Guillaumet, Gérald

2015-10-22

We report the synthesis of 46 tertiary amine-bearing N-alkylated benzo[d]imidazol-2(3H)-ones, imidazo[4,5-b]pyridin-2(3H)-ones, imidazo[4,5-c]pyridin-2(3H)-ones, benzo[d]oxazol-2(3H)-ones, oxazolo[4,5-b]pyridin-2(3H)-ones and N,N'-dialkylated benzo[d]imidazol-2(3H)-ones. These compounds were evaluated against 5-HT7R, 5-HT2AR, 5-HT1AR, and 5-HT6R as potent dual 5-HT7/5-HT2A serotonin receptors ligands. A thorough study of the structure-activity relationship of the aromatic rings and their substituents, the alkyl chain length and the tertiary amine was conducted. 1-(4-(4-(4-Fluorobenzoyl)piperidin-1-yl)butyl)-1H-benzo[d]imidazol-2(3H)-one (79) and 1-(6-(4-(4-fluorobenzoyl)piperidin-1-yl)hexyl)-1H-benzo[d]imidazol-2(3H)-one (81) were identified as full antagonist ligands on cyclic adenosine monophosphate (cAMP, KB = 4.9 and 5.9 nM, respectively) and inositol monophosphate (IP1, KB = 0.6 and 16 nM, respectively) signaling pathways of 5-HT7R and 5-HT2AR. Both antagonists crossed the blood-brain barrier as evaluated with [(18)F] radiolabeled compounds [(18)F]79 and [(18)F]81 in a primate's central nervous system using positron emission tomography. Both radioligands showed standard uptake values ranging from 0.8 to 1.1, a good plasmatic stability, and a distribution consistent with 5-HT7R and 5-HT2AR in the CNS.

Application of high-performance liquid chromatography to the determination of glyoxylate synthesis in chick embryo liver.

PubMed

Qureshi, A A; Elson, C E; Lebeck, L A

1982-11-19

The isolation and identification of three major alpha-keto end products (glyoxylate, pyruvate, alpha-ketoglutarate) of the isocitrate lyase reaction in 18-day chick embryo liver have been described. This was accomplished by the separation of these alpha-keto acids as their 2,4-dinitrophenylhydrazones (DNPHs) by high-performance liquid chromatography (HPLC). The DNPHs of alpha-keto acids were eluted with an isocratic solvent system of methanol-water-acetic acid (60:38.5:1.5) containing 5 mM tetrabutylammonium phosphate from a reversed-phase ultrasphere C18 (IP) and from a radial compression C18 column. The separation can be completed on the radial compression column within 15-20 min as compared to 30-40 min with a conventional reversed-phase column. Retention times and peak areas were integrated for both the assay samples and reference compounds. A relative measure of alpha-keto acid in the peak was calculated by comparison with the standard. The identification of each peak was done on the basis of retention time matching, co-chromatography with authentic compounds, and stopped flow UV-VIS scanning between 240 and 440 nm. Glyoxylate represented 5% of the total product of the isocitrate lyase reaction. Day 18 parallels the peak period of embryonic hepatic glycogenesis which occurs at a time when the original egg glucose reserve has been depleted.

Tuning the mesomorphic properties of phenoxy-terminated smectic liquid crystals: the effect of fluoro substitution.

PubMed

Thompson, Matthew; Carkner, Carolyn; Mosey, Nicholas J; Kapernaum, Nadia; Lemieux, Robert P

2015-05-21

The mesomorphic properties of phenoxy-terminated 5-alkoxy-2-(4-alkoxyphenyl)pyrimidine liquid crystals can be tuned in a predictable fashion with fluoro substituents on the phenoxy end-group. We show that an ortho-fluoro substituent promotes the formation of a tilted smectic C (SmC) phase whereas a para-fluoro substituent promotes the formation of an orthogonal smectic A (SmA) phase. The balance between SmA and SmC phases may be understood in terms of the energetic preference of the phenoxy end-groups to self-assemble via arene-arene interactions in a parallel or antiparallel geometry, and how these non-covalent interactions may cause either a suppression or enhancement of out-of-layer fluctuations at the interface of smectic layers. Calculations of changes in the potential energy of association ΔE for non-covalent dimers of fluoro-substituted n-butyloxybenzene molecules in parallel and antiparallel geometries support this hypothesis. We also show how mesomorphic properties can be further tuned by difluoro and perfluoro substitution, including difluoro substitution at the ortho positions, which uniquely promotes the formation of a SmC-nematic phase sequence.

Synthesis, antimicrobial evaluation and molecular modeling of 5-hydroxyisoquinolinium salt series; the effect of the hydroxyl moiety.

PubMed

Soukup, Ondrej; Dolezal, Rafael; Malinak, David; Marek, Jan; Salajkova, Sarka; Pasdiorova, Marketa; Honegr, Jan; Korabecny, Jan; Nachtigal, Petr; Nachon, Florian; Jun, Daniel; Kuca, Kamil

2016-02-15

In the present paper, we describe the synthesis of a new group of 5-hydroxyisoquinolinium salts with different lengths of alkyl side-chain (C10-C18), and their chromatographic analysis and biological assay for in vitro activity against bacterial and fungal strains. We compare the lipophilicity and efficacy of hydroxylated isoquinolinium salts with the previously published (non-hydroxylated) isoquinolinium salts from the point of view of antibacterial and antifungal versatility and cytotoxic safety. Compound 11 (C18) had to be excluded from the testing due to its low solubility. Compounds 9 and 10 (C14, C16) showed only moderate efficacy against G+ bacteria, notably with excellent potency against Staphyloccocus aureus, but no effect against G- bacteria. In contrast, non-hydroxylated isoquinolinium salts showed excellent antimicrobial efficacy within the whole series, particularly 14 (C14) against G+ strains and 15 (C16) against fungi. The electronic properties and desolvation energies of 5-hydroxyisoquinolinium and isoquinolinium salts were studied by quantum-chemistry calculations employing B3LYP/6-311++G(d,p) method and an implicit water-solvent simulation model (SCRF). Despite the positive mesomeric effect of the hydroxyl moiety reducing the electron density of the quaternary nitrogen, it is probably the higher lipophilicity and lower desolvation energy of isoquinolinium salts, which is responsible for enhanced antimicrobial versatility and efficacy. Copyright © 2016 Elsevier Ltd. All rights reserved.

N-tert-Butyl-N'-(5,7-dimethyl-1,8-naphthyridin-2-yl)urea.

PubMed

Lüning, U; Kühl, C; Bolte, M

2001-08-01

The title compound, C(15)H(20)N(4)O, has been synthesized as an AADD recognition unit for quadruple hydrogen bonds. All non-H atoms of the molecule apart from two methyl groups of the tert-butyl group lie in a common plane. An intramolecular hydrogen bond is formed connecting two N atoms. In the solid state, the title compound crystallizes as a centrosymmetric dimer connected by N-H...O=C interactions with an N...O distance of 2.824 (2) A.

In vitro inhibition of the bovine viral diarrhoea virus by the essential oil of Ocimum basilicum (basil) and monoterpenes

PubMed Central

Kubiça, Thaís F.; Alves, Sydney H.; Weiblen, Rudi; Lovato, Luciane T.

2014-01-01

The bovine viral diarrhoea virus (BVDV) is suggested as a model for antiviral studies of the hepatitis C virus (HCV). The antiviral activity of the essential oil of Ocimum basilicum and the monoterpenes camphor, thymol and 1,8-cineole against BVDV was investigated. The cytotoxicities of the compounds were measured by the MTT (3-(4.5-dimethylthiazol-2-yl)-2.5-diphenyltetrazolium bromide) test, and the antiviral activities were tested by the plaque reduction assay. The oil or compounds were added to the assay in three different time points: a) pre-treatment of the virus (virucidal assay); b) pre-treatment of the cells; or c) post-treatment of the cells (after virus inoculation). The percentage of plaques inhibition for each compound was determined based on the number of plaques in the viral control. The results were expressed by CC50 (50% cytotoxic concentration), IC50 (inhibitory concentration for 50% of plaques) and SI (selectivity index = CC50/IC50). Camphor (CC50 = 4420.12 μg mL−1) and 1,8-cineole (CC50 = 2996.10 μg mL−1) showed the lowest cytotoxicities and the best antiviral activities (camphor SI = 13.88 and 1,8-cineol SI = 9.05) in the virucidal assay. The higher activities achieved by the monoterpenes in the virucidal assay suggest that these compounds act directly on the viral particle. PMID:24948933

Concise Synthesis and Biological Evaluation of 2-Aroyl-5-Amino Benzo[b]thiophene Derivatives As a Novel Class of Potent Antimitotic Agents

PubMed Central

Romagnoli, Romeo; Baraldi, Pier Giovanni; Lopez-Cara, Carlota; Preti, Delia; Tabrizi, Mojgan Aghazadeh; Balzarini, Jan; Bassetto, Marcella; Brancale, Andrea; Fu, Xian-Hua; Gao, Yang; Li, Jun; Zhang, Su-Zhan; Hamel, Ernest; Bortolozzi, Roberta; Basso, Giuseppe; Viola, Giampietro

2014-01-01

The biological importance of microtubules make them an interesting target for the synthesis of antitumor agents. The 2-(3′,4′,5′-trimethoxybenzoyl)-5-aminobenzo[b]thiophene moiety was identified as a novel scaffold for the preparation of potent inhibitors of microtubule polymerization acting through the colchicine site of tubulin. The position of the methoxy group on the benzo[b]thiophene was important for maximal antiproliferative activity. Structure–activity relationship analysis established that the best activities were obtained with amino and methoxy groups placed at the C-5 and C-7 positions, respectively. Compounds 3c–e showed more potent inhibition of tubulin polymerization than combretastatin A-4 and strong binding to the colchicine site. These compounds also demonstrated substantial antiproliferative activity, with IC50 values ranging from 2.6 to 18 nM in a variety of cancer cell lines. Importantly, compound 3c (50 mg/kg), significantly inhibited the growth of the human osteosarcoma MNNG/HOS xenograft in nude mice. PMID:24164557

Intense Photosensitized Emission from Stoichiometric Compounds Featuring Mn(2+) in Seven- and Eightfold Coordination Environments.

PubMed

Reid, Howard O. N.; Kahwa, Ishenkumba A.; White, Andrew J. P.; Williams, David J.

1998-07-27

Synthetic, structural and luminescence studies of stoichiometric crown ether compounds of Mn(2+) in well-defined coordination environments were undertaken in an effort to understand the origin of emitting crystal defects found in cubic F23 [(K18C6)(4)MnBr(4)][TlBr(4)](2) crystals (Fender, N. S.; et al. Inorg. Chem. 1997, 36, 5539). The new compound [Mn(12C4)(2)][MnBr(4)](2)[N(CH(3))(4)](2) (3) features Mn(2+) ions in eight- and fourfold coordination environments of [Mn(12C4)(2)](2+) and MnBr(4)(2)(-) respectively, while Mn(2+) in [Mn(15C5)(H(2)O)(2)][TlBr(5)] (4) is in the sevenfold coordination polyhedron of [Mn(15C5)(H(2)O)(2)](2+). Crystal data for 3: monoclinic, P2(1)/c (No. 14); a = 14.131(3) Å, b = 12.158(1) Å, c = 14.239(2) Å, beta = 110.37(1) degrees, Z = 2, R1 = 0.039 and wR2 = 0.083. For 3, long-lived emission (77 K decay rate approximately 3 x 10 s(-)(1)) from [Mn(12C4)(2)](2+) (the first for eight-coordinate Mn(2+) in stoichiometric compounds) is observed (lambda(max) approximately 546 nm) along with that of the sensitizing MnBr(4)(2)(-) (lambda(max) approximately 513 nm), which is partially quenched. Emission from the seven-coordinate [Mn(15C5)(H(2)O)(2)](2+) species of 4 and [Mn(15C5)(H(2)O)(2)][MnBr(4)] (the first for seven-coordinate Mn(2+) in stoichiometric compounds) peaks at lambda(max) approximately 592 nm. Unusually intense absorptions attributable to the seven-coordinate species are observed at 317 ((2)T(2)((2)I) <-- (6)A(1)), 342 ((4)T(1)((4)P) <-- (6)A(1)), 406 ((4)E((4)G) <-- (6)A(1)), and 531 ((4)T(1)((4)G) <-- (6)A(1)) nm.

Rauvomines A and B, Two Monoterpenoid Indole Alkaloids from Rauvolfia vomitoria.

PubMed

Zeng, Jun; Zhang, Dong-Bo; Zhou, Pan-Pan; Zhang, Qi-Li; Zhao, Lei; Chen, Jian-Jun; Gao, Kun

2017-08-04

Two unusual normonoterpenoid indole alkaloids rauvomine A (1) and rauvomine B (2), together with two known compounds peraksine (3) and alstoyunine A (4), were isolated from the aerial parts of Rauvolfia vomitoria. The structures with absolute configurations of 1 and 2 were elucidated by spectroscopic analysis, single-crystal X-ray diffraction, and electronic circular dichroism (ECD) calculations. Compound 2 is a novel C 18 normonoterpenoid indole alkaloid with a substituted cyclopropane ring that forms an unusual 6/5/6/6/3/5 hexcyclic rearranged ring system. The plausible biogenetic pathways of 1 and 2 were proposed. Compound 2 exhibited significant anti-inflammatory activity.

Levels of perfluorinated compounds in food and dietary intake of PFOS and PFOA in the Netherlands.

PubMed

Noorlander, Cornelle W; van Leeuwen, Stefan P J; Te Biesebeek, Jan Dirk; Mengelers, Marcel J B; Zeilmaker, Marco J

2011-07-13

This study presents concentrations of perfluorinated compounds in food and the dietary intake of perfluorooctane sulfonate (PFOS) and perfluorooctanoate (PFOA) in The Netherlands. The concentrations of perfluorinated compounds in food were analyzed in pooled samples of foodstuffs randomly purchased in several Dutch retail store chains with nation-wide coverage. The concentrations analyzed for PFOS and PFOA were used to assess the exposure to these compounds in The Netherlands. As concentrations in drinking water in The Netherlands were missing for these compounds, conservative default concentrations of 7 pg/g for PFOS and 9 pg/g for PFOA, as reported by European Food Safety Authority, were used in the exposure assessment. In food, 6 out of 14 analyzed perfluorinated compounds could be quantified in the majority of the food categories (perfluoroheptanoic acid (PFHpA), PFOA, perfluorononanoic acid (PFNA), perfluorodecanoic acid (PFDA), perfluoro-1-hexanesulfonate (PFHxS), and PFOS). The highest concentration of the sum of these six compounds was found in crustaceans (825 pg/g product, PFOS: 582 pg/g product) and in lean fish (481 pg/g product, PFOS: 308 pg/g product). Lower concentrations were found in beef, fatty fish, flour, butter, eggs, and cheese (concentrations between 20 and 100 pg/g product; PFOS, 29-82 pg/g product) and milk, pork, bakery products, chicken, vegetable, and industrial oils (concentration lower than 10 pg/g product; PFOS not detected). The median long-term intake for PFOS was 0.3 ng/kg bw/day and for PFOA 0.2 ng/kg bw/day. The corresponding high level intakes (99th percentile) were 0.6 and 0.5 ng/kg bw/day, respectively. These intakes were well below the tolerable daily intake values of both compounds (PFOS, 150 ng/kg bw/day; PFOA, 1500 ng/kg bw/day). The intake calculations quantified the contribution of drinking water to the PFOS and PFOA intake in The Netherlands. Important contributors of PFOA intake were vegetables/fruit and flour. Milk, beef, and lean fish were important contributors of PFOS intake.

Synthesis, characterization and computational study of the newly synthetized sulfonamide molecule

NASA Astrophysics Data System (ADS)

Murthy, P. Krishna; Suneetha, V.; Armaković, Stevan; Armaković, Sanja J.; Suchetan, P. A.; Giri, L.; Rao, R. Sreenivasa

2018-02-01

A new compound N-(2,5-dimethyl-4-nitrophenyl)-4-methylbenzenesulfonamide (NDMPMBS) has been derived from 2,5-dimethyl-4-nitroaniline and 4-methylbenzene-1-sulfonyl chloride. Structure was characterized by SCXRD studies and spectroscopic tools. Compound crystallized in the monoclinic crystal system with P21/c space group a = 10.0549, b = 18.967, c = 8.3087, β = 103.18 and Z = 4. Type and nature of intermolecular interaction in crystal state investigated by 3D-Hirshfeld surface and 2D-finger print plots revealed that title compound stabilized by several interactions. The structural and electronic properties of title compound have been calculated at DFT/B3LYP/6-311G++(d,p) level of theory. Computationally obtained spectral data was compared with experimental results, showing excellent mutual agreement. Assignment of each vibrational wave number was done on the basis of potential energy distribution (PED). Investigation of local reactivity descriptors encompassed visualization of molecular electrostatic potential (MEP) and average local ionization energy (ALIE) surfaces, visualization of Fukui functions, natural bond order (NBO) analysis, bond dissociation energies for hydrogen abstraction (H-BDE) and radial distribution functions (RDF) after molecular dynamics (MD) simulations. MD simulations were also used in order to investigate interaction of NDMPMBS molecule with 1WKR and 3ETT proteins protein.

Investigations of electron attachment to the perfluorocarbon molecules c-C4F8, 2-C4F8, 1,3 C4F6, and c-C5F8

NASA Astrophysics Data System (ADS)

Feil, Stefan; Märk, Tilmann D.; Mauracher, Andreas; Scheier, Paul; Mayhew, Chris A.

2008-11-01

Non-dissociative and dissociative electron attachment to a series of gas-phase perfluorocarbons (PFCs), namely octafluorocyclobutane, c-C4F8, octafluorobut-2-ene (perfluoro-2-butene), 2-C4F8, hexafluorobuta-1,3-diene (1,3 perfluorobutadiene), 1,3 C4F6, and octafluorocyclopentene (perfluorocyclopentene), c-C5F8, of importance to technological plasmas, have been investigated using two different, but complimentary, instruments available in Innsbruck over the electron energy range 0-20 eV. Anion yields as a function of electron energy have been recorded, with the positions and intensities of the electron attachment resonances being determined. One of these instruments is a double focusing sector field mass spectrometer (VG-ZAB-2SEQ), which has been used for measurements requiring high sensitivity and for obtaining accurate relative anion yields. It has also been used to determine the electron detachment lifetimes of the parent anions under various accelerating voltages, and these results are also presented. The second instrument (CELIA) is a trochoidal electron monochromator coupled to a quadrupole mass filter with a pulse counting system for detecting product anionic species. This provides a much higher energy resolution than the VG-ZAB, which makes it a better instrument to investigate narrow energy resonances close to 0 eV. The results of anion yields, peak positions and the relative intensities presented in this paper are compared with previous data of electron attachment to the above PFCs, including investigations by Professor Eugen Illenberger.

(O-Methyl di-thio-carbonato-κS)tri-phenyl-tin(IV).

PubMed

Javed, Fatima; Ali, Saqib; Shah, Wajid; Tahir, M Nawaz; Ullah, Hameed

2013-06-01

In the title compound, [Sn(C6H5)3(C2H3OS2)], the Sn(IV) atom adopts a distorted SnC3S tetra-hedral coordination geometry. A short Sn⋯O contact [2.988 (4) Å] is also present. The phenyl rings are each disordered over two sets of sites with an occupancy ratio of 0.550 (8):0.450 (8). The crystal studied was found to be a racemic twin with a twin component ratio of 0.57 (18):0.43 (18).

(O-Methyl di­thio­carbonato-κS)tri­phenyl­tin(IV)

PubMed Central

Javed, Fatima; Ali, Saqib; Shah, Wajid; Tahir, M. Nawaz; Ullah, Hameed

2013-01-01

In the title compound, [Sn(C6H5)3(C2H3OS2)], the SnIV atom adopts a distorted SnC3S tetra­hedral coordination geometry. A short Sn⋯O contact [2.988 (4) Å] is also present. The phenyl rings are each disordered over two sets of sites with an occupancy ratio of 0.550 (8):0.450 (8). The crystal studied was found to be a racemic twin with a twin component ratio of 0.57 (18):0.43 (18). PMID:23794982

2,2',5,5'-Tetra-methyl-1,1'-(hexane-1,6-di-yl)di-1H-pyrrole.

PubMed

Santos, Ana C; Ramos Silva, Manuela; Monsanto, Paula V; Matos Beja, Ana; Sobral, Abilio J F N

2009-06-17

The mol-ecule of the title compound, C(18)H(28)N(2), composed of two 2,5-dimethyl-pyrrole groups linked by a hexane chain, lies across a crystallographic inversion centre. The mean plane of the pyrrole ring is almost perpendicular to the mean plane of the central chain, making a dihedral angle of 89.09 (8)°. The crystal structure is stabilized by inter-molecular C-H⋯π inter-actions.

Degradation of linear alkylabenzene sulfonate (LAS) and its compounds in Donghu Lake (Hubei, P.R.C.) determined by high performance liquid chromatography (HPLC)

NASA Astrophysics Data System (ADS)

Ayfer, Yediler; Xu, Ying; Zhang, Yongyuan; Chen, Junjian

1990-06-01

Commercial linear alkylbenzene sulfonate (LAS), mixture of alkylchain lengths and phenyl position isomers (C10-C13), is widely used as a major constituent of household and industrial detergents in the People's Republic of China. Degradation process and behaviour of LAS compounds during an 82-hour lake water die-away study, with an added LAS concentration of 1.5mg·L-1, was quantified and accomplished by HPLO-UV after extractionon the SepPek C18 reversed-phase cartridges. The degradation rate became progressively faster with increasing chain length. The technique described in this study is fast, sensitive and specific, and can be used to determine low levels of LAS and for establishing water quality criteria and standards relating to LAS and its compounds.

The C- and N-Terminal Residues of Synthetic Heptapeptide Ion Channels Influence Transport Efficacy Through Phospholipid Bilayers

PubMed Central

Djedovič, Natasha; Ferdani, Riccardo; Harder, Egan; Pajewska, Jolanta; Pajewski, Robert; Weber, Michelle E.; Schlesinger, Paul H.; Gokel, George W.

2008-01-01

The synthetic peptide, R2N-COCH2OCH2CO-Gly-Gly-Gly-Pro-Gly-Gly-Gly-OR’, was shown to be selective for Cl- over K+ when R is n-octadecyl and R’ is benzyl. Nineteen heptapeptides have now been prepared in which the N-terminal and C-terminal residues have been varied. All of the N-terminal residues are dialkyl but the C-terminal chains are esters, 2° amides, or 3° amides. The compounds having varied N-terminal anchors and C-terminal benzyl groups are as follows: 1, R = n-propyl; 2, R = n-hexyl; 3, R = n-octyl; 4, R = n-decyl; 5, R = n-dodecyl; 6, R = n-tetradecyl; 7, R = n-hexadecyl; 8, R = n-octadecyl. Compounds 9-19 have R = n-octadecyl and C-terminal residues as follows: 9, OR’ = OCH2CH3; 10, OR’ = OCH(CH3)2; 11, OR’ = O(CH2)6CH3; 12, OR’ = OCH2-c-C6H11; 13, OR’ = O(CH2)9CH3; 14, OR’ = O (CH2)17CH3; 15, NR’2 = N[(CH2)6CH3]2; 16, NHR’ = NH(CH2)9CH3; 17, NR’2 = N[(CH2)9CH3]2; 18, NHR’ = NH(CH2)17CH3; 19, NR’2 = N[(CH2)17CH3]2. The highest anion transport activities were observed as follows. For the benzyl esters whose N-terminal residues were varied, i.e. 1-8, compound 3 was most active. For the C18 anchored esters 10-14, n-heptyl ester 11 was most active. For the C18 anchored, C-terminal amides 15-19, di-n-decylamide 17 was most active. It was concluded that both the C- and N-terminal anchors were important for channel function in the bilayer but that activity was lost unless only one of the two anchoring groups was dominant. PMID:19633728

RXRα transcriptional inhibitors from the stems of Calophyllum membranaceum.

PubMed

Ming, Meng; Zhang, Xue; Chen, Hai-Feng; Zhu, Ling-Juan; Zeng, De-Quan; Yang, Jian; Wu, Guang-Xun; Wu, Yu-Zhuo; Yao, Xin-Sheng

2016-01-01

Bioassay-guided fractionation of the 60% ethanol extract of the stems of Calophyllum membranaceum using the RXRα transcription activation assay led to the isolation of two new chromanones, calopolyanic acid methyl ester (1) and isopinetoric acid methyl ester (2), two new xanthones, calophylixanthones A-B (3-4), and one new C-glycoside, calophymembranside C (5), along with 13 known compounds. Their structures were elucidated on the basis of extensive spectroscopic data. Compounds 5, 11 and 18 showed transcriptional inhibitory activity of RXRα with 50% inhibitory concentration (IC50) values of 29.95 ± 1.08, 31.06 ± 9.02, and 25.88 ± 1.62 μM, respectively. Copyright © 2015 Elsevier B.V. All rights reserved.

Solute-solvent contact by intermolecular cross relaxation. I. The nature of the water-hydrophobic interface.

PubMed

Nordstierna, Lars; Yushmanov, Pavel V; Furó, István

2006-08-21

Intermolecular cross-relaxation rates between solute and solvent were measured by {1H} 19F nuclear magnetic resonance experiments in aqueous molecular solutions of ammonium perfluoro-octanoate and sodium trifluoroacetate. The experiments performed at three different magnetic fields provide frequency-dependent cross-relaxation rates which demonstrate clearly the lack of extreme narrowing for nuclear spin relaxation by diffusionally modulated intermolecular interactions. Supplemented by suitable intramolecular cross-relaxation, longitudinal relaxation, and self-diffusion data, the obtained cross-relaxation rates are evaluated within the framework of recent relaxation models and provide information about the hydrophobic hydration. In particular, water dynamics around the trifluoromethyl group in ammonium perfluoro-octanoate are more retarded than that in the smaller trifluoroacetate.

[Chemical Constituents from Processed Products of Aconitum Vilmoriniani Radix].

PubMed

Guo, Zhi-jun; Yang, Zhu-ya; Tan, Wen-hong; Zhou, Zhi-hong; Ma, Xiao-xia

2015-05-01

To investigate the chemical constituents of the processed products of Aconitum Vilmorinian Radix. The constituents were isolated by repeated column chromatography over silica gel, alumina and RP-C18 as well as recrystallization. The structures were elucidated on the basis of spectral analysis and physicochemical properties. Ten compounds were obtained from the methanol extract, and they were identified as yunaconitine (1), 8-deacetyl-yunaconitine (2), geniculatine C (3), vilmorrianine B (4), vilmorrianine C(5), vilmorrianine D (6), talatisamine (7), β-sitosterol (8), β-daucosterol (9) and β-sitosterol acetate (10). All compounds are obtained from the processed products of Aconitum Vilmoriniani Radix for the first time.

Experimental and molecular modeling investigation of isopropyl 4-(biphenyl-4-Yl)-2,6,6-trimethyl-5-oxo-1,4,5,6,7,8-hexahydroquinoline-3-carboxylate

NASA Astrophysics Data System (ADS)

Yıldırım, Sema Öztürk; ćetin, Gökalp; Büyükmumcu, Zeki; Şimşek, Rahime; Şafak, Cihat; Butcher, Ray J.; Pekdur, Özlem Savaş

2018-02-01

The most important effect of 1,4-dihydropyridine (1,4-DHP) derivatives with various biological activities is to reduce the influx of extracellular Ca2+ ions. Because of this feature, many 1,4-DHP derivatives have been identified as potent calcium channel blockers and have been included in the treatment as antihypertensive agents. On the other hand, the biphenyl group is an important group in the molecule of biologically active compounds. The active compounds are obtained by introducing the biphenyl group into the structure of various compounds. In this study, the biphenyl group was introduced into the 1,4-DHP ring to reach to hexahydroquinoline (HHQ) derivative as an active calcium channel blocker compound. The structure of the compound was proved by IR, 1H-NMR, Mass spectroscopy, X-ray crystallography and elemental analysis. The cytotoxic properties of the compound has been determined, and biological activity assays continue. The crystal structure of C28H31NO3 was determined by single crystal X-ray diffraction: monoclinic, space group C c, a = 11.9713(3) Å, b = 18.7893(5) Å, c = 10.7358(3) Å, β = 102.411(4)°, Z = 4. The title molecule is twisted with the dihedral angle between two phenyl rings being 50.86(10)°. The optimized geometries of the title compound have been obtained employing DFT method. The calculated geometrical parameters were found to be in agreement with the experimental data.

Exploring ferroelectric and magnetic properties of Tb-substituted m = 5 layered Aurivillius phase thin films

NASA Astrophysics Data System (ADS)

Faraz, Ahmad; Ricote, Jesus; Jimenez, Ricardo; Maity, Tuhin; Schmidt, Michael; Deepak, Nitin; Roy, Saibal; Pemble, Martyn E.; Keeney, Lynette

2018-03-01

Here, we report the effect of A-site substitution of Tb at the expense of Bi on the ferroelectric and magnetic properties in m = 5 layered 2-D Aurivillius Bi6Ti3Fe2O18 thin films. The nominal stoichiometry of the prepared compound is Tb0.40Bi5.6Fe2Ti3O18, Tb0.90Bi5.1Fe2Ti3O18, and Bi6Ti3Fe2O18. Phase examination reveals that only 0.40 mol. % is successfully substituted forming Tb0.40Bi5.6Fe2Ti3O18 thin films. Lateral and vertical piezoresponse switching loops up to 200 °C reveal responses for Bi6Ti3Fe2O18, Tb substituted Tb0.40Bi5.6Fe2Ti3O18, and Tb0.90Bi5.1Fe2Ti3O18 thin films along the in-plane (±42.31 pm/V, 88 pm/V and ±134 pm/V, respectively) compared with the out-of-plane (±6.15 pm/V, 19.83 pm/V and ±37.52 pm/V, respectively). The macroscopic in-plane polarization loops reveal in-plane saturation (Ps) and remanence polarization (Pr) for Bi6Ti3Fe2O18 of ±26.16 μC/cm2 and ±22 μC/cm2, whereas, ±32.75 μC/cm2 and ±22.11 μC/cm2, ±40.30 μC/cm2 and ±28.5 μC/cm2 for Tb0.40Bi5.6Fe2Ti3O18 and Tb0.90Bi5.1Fe2Ti3O18 thin films, respectively. No ferromagnetic signatures were observed for Bi6Ti3Fe2O18 and Tb0.40Bi5.6Fe2Ti3O18. However, a weak response was observed for the Tb0.90Bi5.1Fe2Ti3O18 at 2 K. Microstructural analysis of Tb0.90Bi5.1Fe2Ti3O18 revealed that it contains 4 vol. % Fe:Tb rich areas forming FexTbyOz, which accounts for the observed magnetic moment. This study demonstrates the importance of thorough microstructural analysis when determining whether magnetic signatures can be reliably assigned to the single-phase system. We conclude that Tb0.40Bi5.6Fe2Ti3O18 and Tb0.90Bi5.1Fe2Ti3O18 samples are not multiferroic but demonstrate the potential for Fe-RAM applications.

Controlled release properties of zein-fatty acid blend films for multiple bioactive compounds.

PubMed

Arcan, Iskender; Yemenicioğlu, Ahmet

2014-08-13

To develop edible films having controlled release properties for multiple bioactive compounds, hydrophobicity and morphology of zein films were modified by blending zein with oleic (C18:1)Δ⁹, linoleic (C18:2)Δ(9,12), or lauric (C₁₂) acids in the presence of lecithin. The blend zein films showed 2-8.5- and 1.6-2.9-fold lower initial release rates for the model active compounds, lysozyme (LYS) and (+)-catechin (CAT), than the zein control films, respectively. The change of fatty acid chain length affected both CAT and LYS release rates while the change of fatty acid double bond number affected only the CAT release rate. The film morphologies suggested that the blend films owe their controlled release properties mainly to the microspheres formed within their matrix and encapsulation of active compounds. The blend films showed antilisterial activity and antioxidant activity up to 81 μmol Trolox/cm². The controlled release of multiple bioactive compounds from a single film showed the possibility of combining application of active and bioactive packaging technologies and improving not only safety and quality but also health benefits of packed food.

Acute toxicity assessment of perfluorinated carboxylic acids towards the Baltic microalgae.

PubMed

Latała, Adam; Nędzi, Marcin; Stepnowski, Piotr

2009-09-01

The presence of high-energy carbon-fluorine bonds in perfluoro compounds lends them great stability and causes them to be environmentally persistent. Relatively little is known about the acute toxicity of perfluorinated carboxylic acids (PFCAs) to ecotoxicological markers such as aquatic plants and animals. This study tested the toxicity of these compounds to the green alga Chlorella vulgaris, the diatom Skeletonema marinoi and the blue-green alga Geitlerinema amphibium, which are species representative of the algal flora of the Baltic Sea. The EC(50) values obtained range from 0.28 mM to 12.84 mM. A distinct relationship between hydrophobicity and toxicity is demonstrated. For every extra perfluoromethylene group in the alkyl chain, the toxicity increases twofold. LogEC(50) values are very well correlated linearly with both the number of carbon atoms in the perfluoroalkyl chain and the partition coefficients. The results also indicate that there are clear differences between the responses of particular taxonomic groups of algae: blue-green algae and diatoms are far more sensitive to PFCAs than green algae, probably because of differences in cell wall structure.

Insecticide Activity of Essential Oils of Mentha longifolia, Pulicaria gnaphalodes and Achillea wilhelmsii Against Two Stored Product Pests, the Flour Beetle, Tribolium castaneum, and the Cowpea Weevil, Callosobruchus maculatus

PubMed Central

Khani, Abbas; Asghari, Javad

2012-01-01

Essential oils extracted from the foliage of Mentha longifolia (L.) (Lamiales: Lamiaceae) and Pulicaria gnaphalodes Ventenat (Asterales: Asteraceae), and flowers of Achillea wilhelmsii C. Koch (Asterales: Asteraceae) were tested in the laboratory for volatile toxicity against two storedproduct insects, the flour beetle, Tribolium castaneum Herbst (Coleoptera: Tenebrionidae) and the cowpea weevil, Callosobruchus maculatus F. (Coleoptera: Bruchidae). The chemical composition of the isolated oils was examined by gas chromatography-mass spectrometry. InM longifolia, the major compounds were piperitenon (43.9%), tripal (14.3%), oxathiane (9.3%), piperiton oxide (5.9%), and d-limonene (4.3%). In P. gnaphalodes, the major compounds were chrysanthenyl acetate (22.38%), 2L -4L-dihydroxy eicosane (18.5%), verbenol (16.59%), dehydroaromadendrene (12.54%), β-pinen (6.43%), and 1,8 cineol (5.6%). In A. wilhelmsii, the major compounds were 1,8 cineole (13.03%), caranol (8.26%), alpha pinene (6%), farnesyl acetate (6%), and p-cymene (6%). C maculatus was more susceptible to the tested plant products than T castaneum. The oils of the three plants displayed the same insecticidal activity against C. maculatus based on LC50 values (between 1.54µl/L air in P. gnaphalodes, and 2.65 µl/L air in A. wilhelmsii). While the oils of A. wilhelmsii and M. longifolia showed the same strong insecticidal activity against T. castaneum (LC50 = 10.02 and 13.05 µl/L air, respectively), the oil of P. gnaphalodes revealed poor activity against the insect (LC50 = 297.9 µl/L air). These results suggested that essential oils from the tested plants could be used as potential control agents for stored-product insects. PMID:23413994

Insecticide activity of essential oils of Mentha longifolia, Pulicaria gnaphalodes and Achillea wilhelmsii against two stored product pests, the flour beetle, Tribolium castaneum, and the cowpea weevil, Callosobruchus maculatus.

PubMed

Khani, Abbas; Asghari, Javad

2012-01-01

Essential oils extracted from the foliage of Mentha longifolia (L.) (Lamiales: Lamiaceae) and Pulicaria gnaphalodes Ventenat (Asterales: Asteraceae), and flowers of Achillea wilhelmsii C. Koch (Asterales: Asteraceae) were tested in the laboratory for volatile toxicity against two storedproduct insects, the flour beetle, Tribolium castaneum Herbst (Coleoptera: Tenebrionidae) and the cowpea weevil, Callosobruchus maculatus F. (Coleoptera: Bruchidae). The chemical composition of the isolated oils was examined by gas chromatography-mass spectrometry. InM longifolia, the major compounds were piperitenon (43.9%), tripal (14.3%), oxathiane (9.3%), piperiton oxide (5.9%), and d-limonene (4.3%). In P. gnaphalodes, the major compounds were chrysanthenyl acetate (22.38%), 2L -4L-dihydroxy eicosane (18.5%), verbenol (16.59%), dehydroaromadendrene (12.54%), β-pinen (6.43%), and 1,8 cineol (5.6%). In A. wilhelmsii, the major compounds were 1,8 cineole (13.03%), caranol (8.26%), alpha pinene (6%), farnesyl acetate (6%), and p-cymene (6%). C maculatus was more susceptible to the tested plant products than T castaneum. The oils of the three plants displayed the same insecticidal activity against C. maculatus based on LC(50) values (between 1.54µl/L air in P. gnaphalodes, and 2.65 µl/L air in A. wilhelmsii). While the oils of A. wilhelmsii and M. longifolia showed the same strong insecticidal activity against T. castaneum (LC(50) = 10.02 and 13.05 µl/L air, respectively), the oil of P. gnaphalodes revealed poor activity against the insect (LC(50) = 297.9 µl/L air). These results suggested that essential oils from the tested plants could be used as potential control agents for stored-product insects.

Sol-gel synthesis of K{sub 3}InF{sub 6} and structural characterization of K{sub 2}InC{sub 10}O{sub 10}H{sub 6}F{sub 9}, K{sub 3}InC{sub 12}O{sub 14}H{sub 4}F{sub 18} and K{sub 3}InC{sub 12}O{sub 12}F{sub 18}

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

Labeguerie, Jessica; Gredin, Patrick; Marrot, Jerome

2005-10-15

K{sub 3}InF{sub 6} is synthesized by a sol-gel route starting from indium and potassium acetates dissolved in isopropanol in the stoichiometry 1:3, with trifluoroacetic acid as fluorinating agent. The crystal structures of the organic precursors were solved by X-ray diffraction methods on single crystals. Three organic compounds were isolated and identified: K{sub 2}InC{sub 10}O{sub 10}H{sub 6}F{sub 9}, K{sub 3}InC{sub 12}O{sub 14}H{sub 4}F{sub 18} and K{sub 3}InC{sub 12}O{sub 12}F{sub 18}. The first one, deficient in potassium in comparison with the initial stoichiometry, is unstable. In its crystal structure, acetate as well as trifluoroacetate anions are coordinated to the indium atom. Themore » two other precursors are obtained, respectively, by quick and slow evaporation of the solution. They correspond to the final organic compounds, which give K{sub 3}InF{sub 6} by decomposition at high temperature. The crystal structure of K{sub 3}InC{sub 12}O{sub 14}H{sub 4}F{sub 18} is characterized by complex anions [In(CF{sub 3}COO){sub 4}(OH{sub x}){sub 2}]{sup (5-2x)-} and isolated [CF{sub 3}COOH{sub 2-x}]{sup (x-1)-} molecules with x=2 or 1, surrounded by K{sup +} cations. The crystal structure of K{sub 3}InC{sub 12}O{sub 12}F{sub 18} is only constituted by complex anions [In(CF{sub 3}COO){sub 6}]{sup 3-} and K{sup +} cations. For all these compounds, potassium cations ensure only the electroneutrality of the structure. IR spectra of K{sub 2}InC{sub 10}O{sub 10}H{sub 6}F{sub 9} and K{sub 3}InC{sub 12}O{sub 12}F{sub 18} were also performed at room temperature on pulverized crystals.« less

Tetra- and hexahydro derivatives of aldosterone and 18-hydroxycorticosterone by chemical and microbial reductions.

PubMed

Harnik, M; Aharonowitz, Y; Lamed, R; Kashman, Y

1983-10-01

Preparative methods were developed for reduction with NaBH4 at 0 of 3 beta, 5 alpha- and 3 alpha, 5 beta-tetrahydroaldosterone (1) and (12) to their respective 20 alpha-ol derivatives 2a and 13a. Corroboration of structures was obtained by periodate oxidations to the lactols 3b and 14b and thence, by further oxidation, to the lactones 4 and 15 respectively; these lactones were also independently obtained from 1 and 12. Reduction with NaBH4 at 80 degrees C converted 1 and 12 into 18-hydroxy-3 beta, 5 alpha, 20- and 18-hydroxy-3 alpha, 5 beta, 20-hexahydrocorticosterone 6a and 17a respectively, which were mixtures of epimers at C-20. Compound 17a could also be prepared by reduction of the lactone 21 with sodium aluminum bis-(methoxyethoxy) hydride. Again, periodate oxidations of 6a and 17a gave the lactols 7b and 22b and thence, by Jones oxidation, the diketolactones 8 and 23, which were also prepared from 18-hydroxy-11-dehydrocorticosterone (10) and 18-hydroxycorticosterone (24) respectively. Improved conditions for reduction with Clostridium paraputrificum permitted convenient conversion of aldosterone (11), the corresponding 18 leads to 11 lactone 18a and 18-hydroxycorticosterone (24) into their 3 alpha, 5 beta-tetrahydro derivatives.

Comparison of headspace-oxylipin-volatilomes of some Eastern Himalayan mosses extracted by sample enrichment probe and analysed by gas chromatography-mass spectrometry.

PubMed

Mitra, Souvik; Burger, Barend V; Poddar-Sarkar, Mousumi

2017-03-01

Mosses have an inherent adaptability against different biotic and abiotic stresses. Oxylipins, the volatile metabolites derived from polyunsaturated fatty acids (PUFAs), play a key role in the chemical defence strategy of mosses. In the present study, a comparative survey of these compounds, including an investigation into their precursor fatty acids (FAs), was carried out for the first time on the mosses Brachymenium capitulatum (Mitt.) Paris, Hydrogonium consanguineum (Thwaites & Mitt.) Hilp., Barbula hastata Mitt., and Octoblepharum albidum Hedw. collected from the Eastern Himalayan Biodiversity hotspot. Their headspace volatiles were sampled using a high-efficiency sample enrichment probe (SEP) and were characterized by gas chromatography-mass spectrometric analysis. FAs from neutral lipid (NL) and phospholipid (PL) fractions were also evaluated. Analysis of the oxylipin volatilome revealed the generation of diverse metabolites from C 5 to C 18 , dominated by alkanes, alkenes, saturated and unsaturated alcohols, aldehydes, ketones and cyclic compounds, with pronounced structural variations. The C 6 and C 8 compounds dominated the total volatilome of all the samples. Analyses of FAs from membrane PL and storage NL highlighted the involvement of C 18 and C 20 PUFAs in oxylipin generation. The volatilome of each moss is characterized by a 'signature oxylipin mixture'. Quantitative differences in the C 6 and C 8 metabolites indicate their phylogenetic significance.

Terpenoids and norlignans from Metasequoia glyptostroboides.

PubMed

Dong, Liao-Bin; He, Juan; Wang, Yuan-Yuan; Wu, Xing-De; Deng, Xu; Pan, Zheng-Hong; Xu, Gang; Peng, Li-Yan; Zhao, Yu; Li, Yan; Gong, Xun; Zhao, Qin-Shi

2011-02-25

Four new terpenoids, metaseglyptorin A (1), metasequoic acid C (2), 12α-hydroxy-8,15-isopimaradien-18-oic acid (3), and (-)-acora-2,4(14),8-trien-15-oic acid (4), and three new norlignans, metasequirins D-F (5-7), were isolated from Metasequoia glyptostroboides, together with 15 known compounds. Structures of the new compounds were determined by analysis of their spectroscopic data, and the absolute configuration of 7 was established by the modified Mosher method. All of the compounds were evaluated for cytotoxicity against five human tumor cell lines.

Generation of a novel monoclonal antibody that recognizes the alpha (α)-amidated isoform of a valine residue.

PubMed

Antón Palma, Benito; Leff Gelman, Philippe; Medecigo Ríos, Mayra; Calva Nieves, Juan Carlos; Acevedo Ortuño, Rodolfo; Matus Ortega, Maura Epifanía; Hernández Calderón, Jorge Alberto; Hernández Miramontes, Ricardo; Flores Zamora, Anabel; Salazar Juárez, Alberto

2015-10-13

Alpha (α)-amidation of peptides is a mechanism required for the conversion of prohormones into functional peptide sequences that display biological activities, receptor recognition and signal transduction on target cells. Alpha (α)-amidation occurs in almost all species and amino acids identified in nature. C-terminal valine amide neuropeptides constitute the smallest group of functional peptide compounds identified in neurosecretory structures in vertebrate and invertebrate species. The α-amidated isoform of valine residue (Val-CONH2) was conjugated to KLH-protein carrier and used to immunize mice. Hyperimmune animals displaying high titers of valine amide antisera were used to generate stable hybridoma-secreting mAbs. Three productive hybridoma (P15A4, P17C11, and P18C5) were tested against peptides antigens containing both the C-terminal α-amidated (-CONH2) and free α-carboxylic acid (-COO(-)) isovariant of the valine residue. P18C5 mAb displayed the highest specificity and selectivity against C-terminal valine amidated peptide antigens in different immunoassays. P18C5 mAb-immunoreactivity exhibited a wide distribution along the neuroaxis of the rat brain, particularly in brain areas that did not cross-match with the neuronal distribution of known valine amide neuropeptides (α-MSH, adrenorphin, secretin, UCN1-2). These brain regions varied in the relative amount of putative novel valine amide peptide immunoreactive material (nmol/μg protein) estimated through a fmol-sensitive solid-phase radioimmunoassay (RIA) raised for P18C5 mAb. Our results demonstrate the versatility of a single mAb able to differentiate between two structural subdomains of a single amino acid. This mAb offers a wide spectrum of potential applications in research and medicine, whose uses may extend from a biological reagent (used to detect valine amidated peptide substances in fluids and tissues) to a detoxifying reagent (used to neutralize exogenous toxic amide peptide compounds) or as a specific immunoreagent in immunotherapy settings (used to reduce tumor growth and tumorigenesis) among many others.

Synthesis of 18-hydroxy-19-norcorticosterone and 18-deoxy-19-noraldosterone. Structure determination of related 19-nor steroids by means of 2-D 1H nmr.

PubMed

Harnik, M; Kashman, Y; Carmely, S; Cojocaru, M; Dale, S L; Holbrook, M M; Melby, J C

1986-01-01

The compounds named in the title have been synthesized from the di-(ethylene ketal) of 21-hydroxy-3,20-dioxo-19-norpregn-5-ene-18, 11 beta-lactone and its 5(10)-ene isomer. Reduction of this mixture 1 with sodium aluminum bis-(methoxyethoxy)hydride furnished the 11 beta, 18, 21-triol 2a. Conversion to the 18,21-diacetate 2b, followed by deketalization to the free dione 3 and hydrolysis, afforded 18-hydroxy-19-norcorticosterone 4a which, in the solid state and probably in solution, has the 18,20-hemiacetal structure. Periodate oxidation of 4a gave 11 beta-hydroxy-3-oxo-19-norandrost-4-ene-17 beta, 18-carbolactone 5a, and acid treatment of 4a or its precursor 2a yielded 18-deoxy-19-noraldosterone 6a. The structure of 5a was confirmed by mass spectrometry and 1H nmr, and compared with that of its C-19 methyl homolog 5b and 19-noraldosterone-gamma-etiolactone 8. In particular, 2-D nmr COSY 45 experiments, affording full 1H line assignments, have rigorously established the "natural" beta (axial) configuration of the C-10 hydrogen in the 19-nor lactones 5a and 8, and therefore also in the related 4a, 6a and 19-noraldosterone 7.

Crystal Structure and Magnetic Properties of New Cubic Quaternary Compounds RT2Sn2Zn18 (R = La, Ce, Pr, and Nd, and T = Co and Fe)

NASA Astrophysics Data System (ADS)

Isikawa, Yosikazu; Mizushima, Toshio; Ejiri, Jun-ichi; Kitayama, Shiori; Kumagai, Keigou; Kuwai, Tomohiko; Bordet, Pierre; Lejay, Pascal

2015-07-01

The new cubic quaternary intermetallic compounds RT2Sn2Zn18 (R = La, Ce, Pr, and Nd, and T = Co and Fe) were synthesized by the mixture-metal flux method using Zn and Sn. The crystal structure was investigated by powder X-ray diffraction and with a four-circle X-ray diffractometer using single crystals. The space group of the compounds is Fdbar{3}m (No. 227). The rare-earth atom is at the cubic site which is the center of a cage composed of Zn and Sn atoms. The crystal structure is the same as the CeCr2Al20-type crystal structure except the atoms at the 16c site, i.e., the Zn atoms at the 16c site are completely replaced by Sn atoms, indicating that the compounds are crystallographically new ordered quaternary compounds. The lattice parameter a and the physical properties of the magnetic susceptibility χ, the magnetization M, and the specific heat C of these cubic caged compounds were investigated. LaCo2Sn2Zn18 and LaFe2Sn2Zn18 are enhanced Pauli paramagnets that originate from the Co and Fe itinerant 3d electrons. CeCo2Sn2Zn18 and CeFe2Sn2Zn18 are also enhanced Pauli paramagnets that originate from both the 3d electrons and Ce 4f electrons. PrCo2Sn2Zn18 and PrFe2Sn2Zn18 are nonmagnetic materials with huge values of C divided by temperature, which indicates that the ground state of Pr ions is a non-Kramers' doublet. NdCo2Sn2Zn18 and NdFe2Sn2Zn18 are magnetic materials with the Néel temperatures of 1.0 and 3.8 K, respectively. All eight compounds have large magnetic moments of Co/Fe in the paramagnetic temperature region, and thus their magnetic moments are inferred to be magnetically frustrating owing to the pyrochlore lattice in the low-temperature region.

[Determination of longistylin A and longistylin C in Cajanus cajan].

PubMed

Wang, Dawu; Xiao, Minxun; Li, Yirong; Shen, Xiaoling; Lu, Yuanyuan; Liu, Kanglun; Li, Zhenghong; Hu, Yingjie

2011-10-01

To establish quality control criteria for medicinal herb Cajanus cajan based on the determination of longistylin A and longistylin C, two bioactive and specific stilbenes of the plant. Longistylin A and longistylin C were obtained from the leaves of C. cajan by silica gel column chromatography and identified as marker compounds of this plant by spectroscopic analysis. A RP-HPLC method was established to determine the two compounds. Longistylin A and longistylin C were well separated on a Thermo BDS Hypersil C18 column (4.6 mm x 250 mm, 5 microm) with a mobile phase methanol-water (8:2), and showed good linearity in the range of 0.00288 - 0.0576 microg and 0.0112 - 0.224 microg, respectively. The average recoveries were 98.9% and 97.2% with RSD of 2.4% and 2.2% for these two compounds, respectively. The established analysis method is simple and accurate, whicn can be used for quality control of C. cajan.

Rhodomollacetals A-C, PTP1B Inhibitory Diterpenoids with a 2,3:5,6-Di-seco-grayanane Skeleton from the Leaves of Rhododendron molle.

PubMed

Zhou, Junfei; Sun, Na; Zhang, Hanqi; Zheng, Guijuan; Liu, Junjun; Yao, Guangmin

2017-10-06

Three novel diterpenoids with an unprecedented 2,3:5,6-di-seco-grayanane carbon skeleton, rhodomollacetals A-C (1-3), are isolated from the leaves of Rhododendron molle. Their structures are elucidated by comprehensive spectroscopic techniques and single-crystal X-ray diffraction. Rhodomollacetal A (1) possesses a novel cis/cis/cis/cis-fused 6/6/6/6/5 pentacyclic ring system, featuring an unprecedented 11,13,18-trioxa-pentacyclo [8.7.1.1 5,8 .0 2,8 .0 12,17 ]nonadecane scaffold. Compounds 2 and 3 have a rare 4-oxatricyclo[7.2.1.0 1,6 ]dodecane moiety and a 2,3-dihydro-4H-pyran-4-one unit. Compounds 1-3 showed moderate PTP1B inhibitory activities, and their molecular dockings were investigated.

Identification and hit-to-lead optimization of a novel class of CB1 antagonists.

PubMed

Letourneau, Jeffrey J; Jokiel, Patrick; Olson, John; Riviello, Christopher M; Ho, Koc-Kan; McAleer, Lihong; Yang, Jingchun; Swanson, Robert N; Baker, James; Cowley, Phillip; Edwards, Darren; Ward, Nick; Ohlmeyer, Michael H J; Webb, Maria L

2010-09-15

The discovery, synthesis and preliminary structure-activity relationships (SARs) of a novel class of CB1 antagonists is described. Initial optimization of benzimidazole-based screening hit 4 led to the identification of 'inverted' indole-based lead compound 18c with improved properties versus compound 4 including reduced AlogP, improved microsomal stability and improved aqueous solubility. Compound 18c demonstrates in vivo CB1 antagonist efficacy (CB1 agonist induced hypothermia model) and is orally bioavailable in rat. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

Crystal structure, quantum mechanical investigation, IR and NMR spectroscopy of two new organic perchlorates: (C6H18N3)·(ClO4)3H2O (I) and (C9H11N2)·ClO4(II)

NASA Astrophysics Data System (ADS)

Bayar, I.; Khedhiri, L.; Soudani, S.; Lefebvre, F.; Ferretti, V.; Ben Nasr, C.

2018-06-01

The reaction of perchloric acid with 1-(2-aminoethyl)piperazine or 5,6-dimethyl-benzimidazole results in the formation of 1-(2-amonioethyl)piperazine-1,4-dium triperchlorate hydrate (C6H18N3)·(ClO4)3·H2O (I) or 5,6-dimethyl-benzylimidazolium perchlorate (C9H11N2)·ClO4(II). Both compounds were fully structurally characterized including single crystal X-ray diffraction analysis. Compound (I) crystallizes in the centrosymmetric triclinic space group P 1 bar with the lattice parameters a = 7.455 (2), b = 10.462 (2), c = 10.824 (2) Å, α = 80.832 (2), β = 88.243 (2), γ = 88.160 (2) °, Z = 2 and V = 832.77 (3) Å3. Compound (II) has been found to belong to the P21/c space group of the monoclinic system, with a = 7.590 (3), b = 9.266 (3), c = 16.503 (6) Å, β = 107.38 (2) °, V = 1107.69 (7) Å3 and Z = 4. The structures of (I) and (II) consist of slightly distorted [ClO4]- tetrahedra anions and 1-(2-amonioethyl)piperazine-1,4-dium trication (I) or 5,6-dimethyl-benzylimidazolium cations (II) and additionally a lattice water in (I). The crystal structures of (I) and (II) exhibit complex three-dimensional networks of H-bonds connecting all their components. In the atomic arrangement of (I), the ClO4- anions form corrugated chains, while in (II) the atomic arrangement exhibits wide pseudo-hexagonal channels of ClO4 tetrahedra including the organic entities. The lattice water serves as a link between pairs of cations and pairs of anions via several Osbnd H⋯O and N-H⋯O interactions in compound (I). The vibrational absorption bands were identified by infrared spectroscopy. These compounds were also investigated by solid-state 13C, 35Cl and 15N NMR spectroscopy. DFT calculations allowed the attribution of the IR and NMR bands. Intermolecular interactions were investigated by Hirshfeld surfaces. Electronic properties such as HOMO and LUMO energies were derived.

Expanding Thorium Hydride Chemistry Through Th²⁺, Including the Synthesis of a Mixed-Valent Th⁴⁺/Th³⁺ Hydride Complex.

PubMed

Langeslay, Ryan R; Fieser, Megan E; Ziller, Joseph W; Furche, Filipp; Evans, William J

2016-03-30

The reactivity of the recently discovered Th(2+) complex [K(18-crown-6)(THF)2][Cp″3Th], 1 [Cp'' = C5H3(SiMe3)2-1,3], with hydrogen reagents has been investigated and found to provide syntheses of new classes of thorium hydride compounds. Complex 1 reacts with [Et3NH][BPh4] to form the terminal Th(4+) hydride complex Cp″3ThH, 2, a reaction that formally involves a net two-electron reduction. Complex 1 also reacts in the solid state and in solution with H2 to form a mixed-valent bimetallic product, [K(18-crown-6)(Et2O)][Cp″2ThH2]2, 3, which was analyzed by X-ray crystallography, electron paramagnetic resonance and optical spectroscopy, and density functional theory. The existence of 3, which formally contains Th(3+) and Th(4+), suggested that KC8 could reduce [(C5Me5)2ThH2]2. In the presence of 18-crown-6, this reaction forms an analogous mixed-valent product formulated as [K(18-crown-6)(THF)][(C5Me5)2ThH2]2, 4. A similar complex with (C5Me4H)(1-) ligands was not obtained, but reaction of (C5Me4H)3Th with H2 in the presence of KC8 and 2.2.2-cryptand at -45 °C produced two monometallic hydride products, namely, (C5Me4H)3ThH, 5, and [K(2.2.2-cryptand)]{(C5Me4H)2[η(1):η(5)-C5Me3H(CH2)]ThH]}, 6. Complex 6 contains a metalated tetramethylcyclopentadienyl dianion, [C5Me3H(CH2)](2-), that binds in a tuck-in mode.

Bis(azido) compounds of Pd and Pt with bulky phosphine ligands (dppn=1,8-bis(diphenylphosphino)naphthalene, dppf=1,1‧-bis(diphenylphosphino)ferrocene, 1-dpn=1-diphenylphosphino-naphthalene): Preparation, structures, and reactivity toward isocyanides

NASA Astrophysics Data System (ADS)

Huh, Hyun Sue; Lee, Yeon Kyoung; Lee, Soon W.

2006-05-01

Pd-bis(azido) compounds [Pd(dppn)(N 3) 2] and [Pd(dppf)(N 3) 2], which contain bulky chelating bis(phosphine) ligands (dppn=1,8-bis(diphenylphosphino)naphthalene, dppf=1,1'-bis(diphenylphosphino)ferrocene), were prepared from the corresponding chlorides and NaN 3. We also prepared the Pt-bis(azido) compound [Pt(1-dpn)(SMe 2)(N 3) 2] containing a bulky monodentate phosphine (1-dpn=1-diphenylphosphino-naphthalene). All these compounds underwent [2+3] cycloaddition with isocyanides (R-NC, R=cyclohexyl, tert-butyl, 2,6-dimethylphenyl) to convert azido ligands to five-membered, C-coordinated tetrazolate rings. In addition, we observed the [Pd(dppn)Cl 2]-mediated C-C coupling of PhC tbnd6 CH to generate the η 2-PhC tbnd6 C-C tbnd6 CPh ligand. All compounds have been structurally characterized by X-ray diffraction.

Homoleptic diphosphacyclobutadiene complexes [M(η(4)-P2C2R2)2]x- (M = Fe, Co; x = 0, 1).

PubMed

Wolf, Robert; Ehlers, Andreas W; Khusniyarov, Marat M; Hartl, František; de Bruin, Bas; Long, Gary J; Grandjean, Fernande; Schappacher, Falko M; Pöttgen, Rainer; Slootweg, J Chris; Lutz, Martin; Spek, Anthony L; Lammertsma, Koop

2010-12-27

The preparation and comprehensive characterization of a series of homoleptic sandwich complexes containing diphosphacyclobutadiene ligands are reported. Compounds [K([18]crown-6)(thf)(2)][Fe(η(4)-P(2)C(2)tBu(2))(2)] (K1), [K([18]crown-6)(thf)(2)][Co(η(4)-P(2)C(2)tBu(2))(2)] (K2), and [K([18]crown-6)(thf)(2)][Co(η(4)-P(2)C(2)Ad(2))(2)] (K3, Ad = adamantyl) were obtained from reactions of [K([18]crown-6)(thf)(2)][M(η(4)-C(14)H(10))(2)] (M = Fe, Co) with tBuC[triple bond]P (1, 2), or with AdC[triple bond]P (3). Neutral sandwiches [M(η(4)-P(2)C(2)tBu(2))(2)] (4: M = Fe 5: M = Co) were obtained by oxidizing 1 and 2 with [Cp(2)Fe]PF(6). Cyclic voltammetry and spectro-electrochemistry indicate that the two [M(η(4)-P(2)C(2)tBu(2))(2)](-)/[M(η(4)-P(2)C(2)tBu(2))(2)] moieties can be reversibly interconverted by one electron oxidation and reduction, respectively. Complexes 1-5 were characterized by multinuclear NMR, EPR (1 and 5), UV/Vis, and Mössbauer spectroscopies (1 and 4), mass spectrometry (4 and 5), and microanalysis (1-3). The molecular structures of 1-5 were determined by using X-ray crystallography. Essentially D(2d)-symmetric structures were found for all five complexes, which show the two 1,3-diphosphacyclobutadiene rings in a staggered orientation. Density functional theory calculations revealed the importance of covalent metal-ligand π bonding in 1-5. Possible oxidation state assignments for the metal ions are discussed.

Discovery of a Highly Potent, Cell-Permeable Macrocyclic Peptidomimetic (MM-589) Targeting the WD Repeat Domain 5 Protein (WDR5)–Mixed Lineage Leukemia (MLL) Protein–Protein Interaction

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

Karatas, Hacer; Li, Yangbing; Liu, Liu

We report herein the design, synthesis, and evaluation of macrocyclic peptidomimetics that bind to WD repeat domain 5 (WDR5) and block the WDR5–mixed lineage leukemia (MLL) protein–protein interaction. Compound 18 (MM-589) binds to WDR5 with an IC50 value of 0.90 nM (Ki value <1 nM) and inhibits the MLL H3K4 methyltransferase (HMT) activity with an IC50 value of 12.7 nM. Compound 18 potently and selectively inhibits cell growth in human leukemia cell lines harboring MLL translocations and is >40 times better than the previously reported compound MM-401. Cocrystal structures of 16 and 18 complexed with WDR5 provide structural basis formore » their high affinity binding to WDR5. Additionally, we have developed and optimized a new AlphaLISA-based MLL HMT functional assay to facilitate the functional evaluation of these designed compounds. Compound 18 represents the most potent inhibitor of the WDR5–MLL interaction reported to date, and further optimization of 18 may yield a new therapy for acute leukemia.« less

Characterization of hydrocortisone biometabolites and 18S rRNA gene in Chlamydomonas reinhardtii cultures.

PubMed

Ghasemi, Younes; Rasoul-Amini, Sara; Morowvat, Mohammad Hossein; Raee, Mohammad Javad; Ghoshoon, Mohammad Bagher; Nouri, Fatemeh; Negintaji, Narges; Parvizi, Rezvan; Mosavi-Azam, Seyed Bagher

2008-10-31

A unicellular microalga, Chlamydomonas reinhardtii, was isolated from rice paddy-field soil and water samples and used in the biotransformation of hydrocortisone (1). This strain has not been previously tested for steroid bioconversion. Fermentation was carried out in BG-11 medium supplemented with 0.05% substrate at 25 degrees C for 14 days of incubation. The products obtained were chromatographically purified and characterized using spectroscopic methods. 11b,17 beta-Dihydroxyandrost-4-en-3-one (2), 11 beta-hydroxyandrost-4-en-3,17-dione (3), 11 beta,17 alpha,20 beta,21-tetrahydroxypregn-4-en-3-one (4) and prednisolone (5) were the main products of the bioconversion. The observed bioreaction features were the side chain degradation of the substrate to give compounds 2 and 3 and the 20-ketone reduction and 1,2-dehydrogenation affording compounds 4 and 5, respectively. A time course study showed the accumulation of product 2 from the second day of the fermentation and of compounds 3, 4 and 5 from the third day. All the metabolites reached their maximum concentration in seven days. Microalgal 18S rRNA gene was also amplified by PCR. PCR products were sequenced to confirm their authenticity as 18S rRNA gene of microalgae. The result of PCR blasted with other sequenced microalgae in NCBI showed 100% homology to the 18S small subunit rRNA of two Chlamydomonas reinhardtii spp.

Studies of new perfluoroether elastomeric sealants. [for aircraft fuel tanks

NASA Technical Reports Server (NTRS)

Basiulis, D. I.; Salisbury, D. P.

1981-01-01

Channel and filleting sealants were developed successfully from cyano and diamidoxime terminated perfluoro alkylene ether prepolymers. The prepolymers were polymerized, formulated and tested. The polymers and/or formulations therefrom were evaluated as to their physical, mechanical and chemical properties (i.e., specific gravity, hardness, nonvolatile content, corrosion resistance, stress corrosion, pressure rupture resistance, low temperature flexibility, gap sealing efficiency, tensile strength and elongation, dynamic mechanical behavior, compression set, fuel resistance, thermal properties and processability). Other applications of the formulated polymrs and incorporation of the basic prepolymers into other polymeric systems were investigated. A cyano terminated perfluoro alkylene oxide triazine was formulated and partially evaluated. The channel sealant in its present formulation has excellent pressure rupture resistance and surpasses present MIL specifications before and after fuel and heat aging.

Identification of an organic semiconductor superlattice structure of pentacene and perfluoro-pentacene through resonant and non-resonant X-ray scattering

DOE PAGES

Kowarik, S.; Hinderhofer, A.; Wang, C.; ...

2015-11-30

Highly crystalline and stable molecular superlattices are grown with the smallest possible stacking period using monolayers (MLs) of the organic semiconductors pentacene (PEN) and perfluoro-pentacene (PFP). Superlattice reflections in X-ray reflectivity and their energy dependence in resonant soft X-ray reflectivity measurements show that PFP and PEN MLs indeed alternate even though the coherent ordering is lost after ~ 4 ML. The observed lattice spacing of 15.9 Å in the superlattice is larger than in pure PEN and PFP films, presumably because of more upright standing molecules and lack of interdigitation between the incommensurate crystalline PEN and PFP layers. The findingsmore » are important for the development of novel organic quantum optoelectronic devices.« less

1,5-Bis[1-(2,4-dihy­droxy­phen­yl)ethyl­idene]carbonohydrazide dimethyl­formamide disolvate

PubMed Central

He, Qing-Peng; Tan, Bo; Lu, Ze-Hua

2010-01-01

In the title compound, C17H18N4O5·2C3H7NO, two solvent mol­ecules are linked to the main mol­ecule via N—H⋯O and O—H⋯O hydrogen bonds, forming a hydrogen-bonded trimer. Intra­molecular O—H⋯N hydrogen bonds influence the mol­ecular conformation of the main mol­ecule, and the two benzene rings form a dihedral angle of 10.55 (18)°. In the crystal, inter­molecular O—H⋯O hydrogen bonds link hydrogen-bonded trimers into ribbons extending along the b axis. PMID:21589135

Cytotoxic triterpenoid saponins from the fruits of Aesculus pavia L.

PubMed

Zhang, Zhizhen; Li, Shiyou

2007-08-01

Continued chemical investigation on the fruits of North American Aesculus pavia L. resulted in the isolation and identification of 13 polyhydroxyoleanene pentacyclic triterpenoid saponins, named aesculiosides IIe-IIk (1-7), and IIIa-IIIf (8-13), together with 18 known compounds: aesculiosides Ia-Ie (14-18), IIa-IId (19-22), IVa-IVc (23-25), 3-O-[beta-D-galactopyranosyl(1-->2)]-alpha-L-arabinofuranosyl(1-->3)-beta-D-glucuronopyranosyl-21,22-O-diangeloyl-3beta,15 alpha,16 alpha,21 beta,22 alpha,28-hexahydroxyolean-12-ene (26), 3-O-[beta-D-glucopyranosyl(1-->2)]-alpha-L-arabinofuranosyl(1-->3)-beta-D-glucuronopyranosyl-21,22-O-diangeloyl-3beta,16 alpha,21 beta,22 alpha,24 beta,28-hexahydroxyolean-12-ene (27), 3-O-[beta-D-galactopyranosyl(1-->2)]-alpha-L-arabinofuranosyl(1-->3)-beta-D-glucuronopyranosyl-21,22-O-diangeloyl-3beta,16 alpha,21 beta,22 alpha,28-pentahydroxyolean-12-ene (28), R(1)-barrigenol (29), scopolin (30), and 5-methoxyscopolin (31). The structures of these compounds were elucidated by spectroscopic and chemical analyses. Compounds 14-22 and 26-28 were tested in vitro for their activity against 59 cell lines from nine different human cancers including leukemia, non-small cell lung, colon, CNS, melanoma, ovarian, renal, prostate, and breast. It was found that compounds with two-acyl groups at C-21 and C-22 had cytotoxic activity for all cell lines tested with GI(50) 0.175-8.71 microM, while compounds without acyl groups at C-21 and C-22 had weak or no cytotoxic activity. These results suggest that the acyl groups at C-21 and C-22 are essential for their activity.

Divalent carbon(0) chemistry, part 1: Parent compounds.

PubMed

Tonner, Ralf; Frenking, Gernot

2008-01-01

Quantum-chemical calculations with DFT (BP86) and ab initio methods [MP2, SCS-MP2, CCSD(T)] have been carried out for the molecules C(PH(3))(2) (1), C(PMe(3))(2) (2), C(PPh(3))(2) (3), C(PPh(3))(CO) (4), C(CO)(2) (5), C(NHC(H))(2) (6), C(NHC(Me))(2) (7) (Me(2)N)(2)C=C=C(NMe(2))(2) (8), and NHC (9), where NHC=N-heterocyclic carbene and NHC(Me)=N-methyl-substituted NHC. The electronic structure in 1-9 was analyzed with charge- and energy-partitioning methods. The results show that the bonding situations in L(2)C compounds 1-8 can be interpreted in terms of donor-acceptor interactions between closed-shell ligands L and a carbon atom which has two lone-pair orbitals L-->C<--L. This holds particularly for the carbodiphosphoranes 1-3 where L=PR(3), which therefore are classified as divalent carbon(0) compounds. The NBO analysis suggests that the best Lewis structures for the carbodicarbenes 6 and 7 where L is a NHC ligand have C==C==C double bonds as in the tetraaminoallene 8. However, the Lewis structures of 6-8, in which two lone-pair orbitals at the central carbon atom are enforced, have only a slightly higher residual density. Visual inspection of the frontier orbitals of the latter species reveals their pronounced lone-pair character, which suggests that even the quasi-linear tetraaminoallene 8 is a "masked" divalent carbon(0) compound. This explains the very shallow bending potential of 8. The same conclusion is drawn for phosphoranylketene 4 and for carbon suboxide (5), which according to the bonding analysis have hidden double-lone-pair character. The AIM analysis and the EDA calculations support the assignment of carbodiphosphoranes as divalent carbon(0) compounds, while NHC 9 is characterized as a divalent carbon(II) compound. The L-->C((1)D) donor-acceptor bonds are roughly twice as strong as the respective L-->BH(3) bond.

Microbial biotransformation of gentiopicroside by the endophytic fungus Penicillium crustosum 2T01Y01.

PubMed

Zeng, Wen-Liang; Li, Wan-Kui; Han, Han; Tao, Yan-Yan; Yang, Li; Wang, Zheng-Tao; Chen, Kai-Xian

2014-01-01

Endophytic fungi are symbiotic with plants and possess multienzyme systems showing promising metabolite potency with region selectivity and stereoselectivity. The aim of this study was to use these special microorganisms as an in vitro model to mimic the potential mammalian metabolites of a natural iridoid gentiopicroside (GPS, compound 1). The fungi isolated from a medicinal plant, Dendrobium candidum Wall. ex Lindl., were screened for their biotransformation abilities with GPS as the substrate, and one strain with high converting potency was identified as Penicillium crustosum 2T01Y01 on the basis of the sequence of the internal transcribed spacer of the ribosomal DNA region. Upon the optimized incubation of P. crustosum 2T01Y01 with the substrate, seven deglycosylated metabolites were detected by ultraperformance liquid chromatography/quadrupole time of flight mass spectrometry (UPLC/Q-TOF MS). Preparative-scale biotransformation with whole cells of the endophytic fungus resulted in the production of five metabolites, including three novel ones, 5α-(hydroxymethyl)-6β-methyl-3,4,5,6-tetrahydropyrano[3,4-c]pyran-1(8H)-one (compound 2), (Z)-4-(1-hydroxybut-3-en-2-yl)-5,6-dihydropyran-2-one (compound 3), and (E)-4-(1-hydroxybut-3-en-2-yl)-5,6-dihydropyran-2-one (compound 4), along with two known ones, 5α-(hydroxymethyl)-6β-methyl-1H,3H-5,6-dihydropyrano[3,4-c]pyran-1(3H)-one (compound 5) and 5α-(hydroxymethyl)-6α-methyl-5,6-dihydropyrano[3,4-c]pyran-1(3H)-one (compound 6), aided by nuclear magnetic resonance and high-resolution mass spectral analyses. The other two metabolites were tentatively identified by online UPLC/Q-TOF MS as 5-hydroxymethyl-5,6-dihydroisochromen-1-one (compound 7) and 5-hydroxymethyl-3,4,5,6-tetrahydroisochromen-1-one (compound 8), and compound 8 is a new metabolite. To test the metabolic mechanism, the β-glucosidase activity of the fungus P. crustosum 2T01Y01 was assayed with ρ-nitrophenyl-β-d-glucopyranoside as a probe substrate, and the pathway of GPS biotransformation by strain 2T01Y01 is proposed. In addition, the hepatoprotective activities of GPS and metabolite compounds 2, 5, and 6 against human hepatocyte line HL-7702 injury induced by hydrogen peroxide were evaluated.

Microbial Biotransformation of Gentiopicroside by the Endophytic Fungus Penicillium crustosum 2T01Y01

PubMed Central

Zeng, Wen-Liang; Li, Wan-Kui; Han, Han; Tao, Yan-Yan; Yang, Li; Chen, Kai-Xian

2014-01-01

Endophytic fungi are symbiotic with plants and possess multienzyme systems showing promising metabolite potency with region selectivity and stereoselectivity. The aim of this study was to use these special microorganisms as an in vitro model to mimic the potential mammalian metabolites of a natural iridoid gentiopicroside (GPS, compound 1). The fungi isolated from a medicinal plant, Dendrobium candidum Wall. ex Lindl., were screened for their biotransformation abilities with GPS as the substrate, and one strain with high converting potency was identified as Penicillium crustosum 2T01Y01 on the basis of the sequence of the internal transcribed spacer of the ribosomal DNA region. Upon the optimized incubation of P. crustosum 2T01Y01 with the substrate, seven deglycosylated metabolites were detected by ultraperformance liquid chromatography/quadrupole time of flight mass spectrometry (UPLC/Q-TOF MS). Preparative-scale biotransformation with whole cells of the endophytic fungus resulted in the production of five metabolites, including three novel ones, 5α-(hydroxymethyl)-6β-methyl-3,4,5,6-tetrahydropyrano[3,4-c]pyran-1(8H)-one (compound 2), (Z)-4-(1-hydroxybut-3-en-2-yl)-5,6-dihydropyran-2-one (compound 3), and (E)-4-(1-hydroxybut-3-en-2-yl)-5,6-dihydropyran-2-one (compound 4), along with two known ones, 5α-(hydroxymethyl)-6β-methyl-1H,3H-5,6-dihydropyrano[3,4-c]pyran-1(3H)-one (compound 5) and 5α-(hydroxymethyl)-6α-methyl-5,6-dihydropyrano[3,4-c]pyran-1(3H)-one (compound 6), aided by nuclear magnetic resonance and high-resolution mass spectral analyses. The other two metabolites were tentatively identified by online UPLC/Q-TOF MS as 5-hydroxymethyl-5,6-dihydroisochromen-1-one (compound 7) and 5-hydroxymethyl-3,4,5,6-tetrahydroisochromen-1-one (compound 8), and compound 8 is a new metabolite. To test the metabolic mechanism, the β-glucosidase activity of the fungus P. crustosum 2T01Y01 was assayed with ρ-nitrophenyl-β-d-glucopyranoside as a probe substrate, and the pathway of GPS biotransformation by strain 2T01Y01 is proposed. In addition, the hepatoprotective activities of GPS and metabolite compounds 2, 5, and 6 against human hepatocyte line HL-7702 injury induced by hydrogen peroxide were evaluated. PMID:24141132

Intermetallic Compounds Formed in Sn-20In-2.8Ag Solder BGA Packages with Ag/Cu Pads

NASA Astrophysics Data System (ADS)

Jain, C. C.; Wang, S. S.; Huang, K. W.; Chuang, T. H.

2009-03-01

The interfacial reactions in a Sn-20In-2.8Ag solder ball grid array (BGA) package with immersion Ag surface finish are investigated. After reflow, the Ag thin film dissolves quickly into the solder matrix, and scallop-shaped intermetallic layers, with compositions of (Cu0.98Ag0.02)6(In0.59Sn0.41)5, appear at the interfaces between Sn-20In-2.8Ag solder ball and Cu pad. No evident growth of the (Cu0.98Ag0.02)6(Sn0.59In0.41)5 intermetallic compounds was observed after prolonged aging at 100 °C. However, the growth accelerated at 150 °C, with more intermetallic scallops floating into the solder matrix. The intermetallic thickness versus the square root of reaction time ( t 1/2) shows a linear relation, indicating that the growth of intermetallic compounds is diffusion-controlled. Ball shear tests show that the strength of Sn-20In-2.8Ag solder joints after reflow is 4.4 N, which increases to 5.18 N and 5.14 N after aging at 100 and 150 °C, respectively.

Synthesis and Biological Evaluation of 3-Benzylidene-4-chromanone Derivatives as Free Radical Scavengers and α-Glucosidase Inhibitors.

PubMed

Takao, Koichi; Yamashita, Marimo; Yashiro, Aruki; Sugita, Yoshiaki

2016-01-01

A series of 3-benzylidene-4-chromanone derivatives (3-20) were synthesized and the structure-activity relationships for antioxidant and α-glucosidase inhibitory activities were evaluated. Among synthesized compounds, compounds 5, 13, 18, which contain catechol moiety, showed the potent 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging activity (5: EC50 13 µM; 13: EC50 14 µM; 18: EC50 13 µM). The compounds 12, 14, 18 showed higher α-glucosidase inhibitory activity (12: IC50 15 µM; 14: IC50 25 µM; 18: IC50 28 µM). The compound 18 showed both of potent DPPH radical scavenging and α-glucosidase inhibitory activities. These data suggest that 3-benzylidene-4-chromanone derivatives, such as compound 18, may serve as the lead compound for the development of novel α-glucosidase inhibitors with antioxidant activity.

Effects of strong hydrogen bonds and weak intermolecular interactions on supramolecular assemblies of 4-fluorobenzylamine

NASA Astrophysics Data System (ADS)

Wang, Shi; Ding, Xue-Hua; Li, Yong-Hua; Huang, Wei

2015-07-01

A series of supramolecular salts have been obtained by the self-assembly of 4-fluorobenzylamine and halide ions or metal chloride with 18-crown-6 as the host in the hydrochloric acid medium, i.e. (C7H9FN)+ṡX- (X = Cl-, 1; Br-, 2), [(C7H9FN)2ṡ(18-crown-6)2]2+ṡ(MCl4)2- (M = Mn, 3; Co, 5; Zn, 7; Cd, 8), [(C7H9FN)ṡ(18-crown-6)]+ṡ(FeCl4)- (4) and [(C7H9FN)ṡ(18-crown-6)]+ṡ1/2(CuCl4)2- (6). Structural analyses indicate that 1-2 crystallize in the triclinic space group P-1, 4 in orthorhombic space group Pnma and 3, 5, 6-8 in the monoclinic space group P21/c or C2/c. In these compounds, extensive intermolecular interactions have been utilized for the self-assembly of diverse supramolecular architectures, ranging from strong N-H⋯X (X = O, Cl, Br) hydrogen bonds to weak C-H⋯Y (Y = F, Cl, π) interactions. N-H⋯Cl/Br hydrogen bonds offer the major driving force in the crystal packing of salts 1-2 while N-H⋯O hydrogen bonds are found in salts 3-8.

Comparison of 18F-FACBC and 11C-choline PET/CT in patients with radically treated prostate cancer and biochemical relapse: preliminary results.

PubMed

Nanni, Cristina; Schiavina, Riccardo; Boschi, Stefano; Ambrosini, Valentina; Pettinato, Cinzia; Brunocilla, Eugenio; Martorana, Giuseppe; Fanti, Stefano

2013-07-01

We assessed the rate of detection rate of recurrent prostate cancer by PET/CT using anti-3-(18)F-FACBC, a new synthetic amino acid, in comparison to that using (11)C-choline as part of an ongoing prospective single-centre study. Included in the study were 15 patients with biochemical relapse after initial radical treatment of prostate cancer. All the patients underwent anti-3-(18)F-FACBC PET/CT and (11)C-choline PET/CT within a 7-day period. The detection rates using the two compounds were determined and the target-to-background ratios (TBR) of each lesion are reported. No adverse reactions to anti-3-(18)F-FACBC PET/CT were noted. On a patient basis, (11)C-choline PET/CT was positive in 3 patients and negative in 12 (detection rate 20%), and anti-3-(18)F-FACBC PET/CT was positive in 6 patients and negative in 9 (detection rate 40%). On a lesion basis, (11)C-choline detected 6 lesions (4 bone, 1 lymph node, 1 local relapse), and anti-3-(18)F-FACBC detected 11 lesions (5 bone, 5 lymph node, 1 local relapse). All (11)C-choline-positive lesions were also identified by anti-3-(18)F-FACBC PET/CT. The TBR of anti-3-(18)F-FACBC was greater than that of (11)C-choline in 8/11 lesions, as were image quality and contrast. Our preliminary results indicate that anti-3-(18)F-FACBC may be superior to (11)C-choline for the identification of disease recurrence in the setting of biochemical failure. Further studies are required to assess efficacy of anti-3-(18)F-FACBC in a larger series of prostate cancer patients.

Quantitative Analysis of Carbon Flow into Photosynthetic Products Functioning as Carbon Storage in the Marine Coccolithophore, Emiliania huxleyi.

PubMed

Tsuji, Yoshinori; Yamazaki, Masatoshi; Suzuki, Iwane; Shiraiwa, Yoshihiro

2015-08-01

The bloom-forming coccolithophore Emiliania huxleyi (Haptophyta) is a dominant marine phytoplankton, cells of which are covered with calcareous plates (coccoliths). E. huxleyi produces unique lipids of C37-C40 long-chain ketones (alkenones) with two to four trans-unsaturated bonds, β-glucan (but not α-glucan) and acid polysaccharide (AP) associated with the morphogenesis of CaCO3 crystals in coccoliths. Despite such unique features, there is no detailed information on the patterns of carbon allocation into these compounds. Therefore, we performed quantitative estimation of carbon flow into various macromolecular products by conducting (14)C-radiotracer experiments using NaH(14)CO3 as a substrate. Photosynthetic (14)C incorporation into low molecular-mass compounds (LMC), extracellular AP, alkenones, and total lipids except alkenones was estimated to be 35, 13, 17, and 25 % of total (14)C fixation in logarithmic growth phase cells and 33, 19, 18, and 18 % in stationary growth phase cells, respectively. However, less than 1 % of (14)C was incorporated into β-glucan in both cells. (14)C-mannitol occupied ca. 5 % of total fixed (14)C as the most dominant LMC product. Levels of all (14)C compounds decreased in the dark. Therefore, alkenones and LMC (including mannitol), but not β-glucan, function in carbon/energy storage in E. huxleyi, irrespective of the growth phase. Compared with other algae, the low carbon flux into β-glucan is a unique feature of carbon metabolism in E. huxelyi.

Synthesis and evaluation of triazole linked glycosylated 18β-glycyrrhetinic acid derivatives as anticancer agents.

PubMed

Parida, Pravat Kumar; Sau, Abhijit; Ghosh, Tamashree; Jana, Kuladip; Biswas, Kaushik; Raha, Sanghamitra; Misra, Anup Kumar

2014-08-15

A series of glycosyl triazol linked 18β-glycyrrhetinic acid (GA) derivatives have been synthesized using 1,3-dipolar cycloaddition reaction of per-O-acetylated glycosyl azide derivatives (4a-h) with propargyl ester of 18β-glycyrrhetinic acid (GA) (2 and 3) following the concept of 'Click chemistry'. The synthesized triazole derivatives were de-O-acetylated to furnish compounds (7a-h and 8a-c) with free hydroxyl groups in the carbohydrate moieties, which were evaluated for their anticancer potential against human cervical cancer cells (HeLa) and normal kidney epithelial (NKE) cells. GA (1), compound 7d, compound 7g and compound 8c showed promising anticancer activities. Copyright © 2014 Elsevier Ltd. All rights reserved.

Design, synthesis and activity of novel sorafenib analogues bearing chalcone unit.

PubMed

Wang, Min; Xu, Shan; Wu, Chunjiang; Liu, Xiaobo; Tao, Hong; Huang, Yanli; Liu, Yongchan; Zheng, Pengwu; Zhu, Wufu

2016-11-15

Two series of sorafenib derivatives (N-methylpicolinamide-4-oxy) chalcones (5a-o, 7a-e) were synthesized and characterized by NMR and MS. All of the target compounds were evaluated for the cytotoxicity against A549, HepG2, MCF-7, and PC-3 cancer cell lines and some selected compounds were further evaluated for the activity against VEGFR-2/KDR and BRAF kinases. The results indicated that all the compounds showed moderate to good antitumor activity, and the compound 5c showed well cytotoxic activity against HepG2, MCF-7 and PC-3 cell lines with IC 50 values of 0.56±0.83μM, 3.88±1.03μM and 3.15±0.81μM, which were 1.03-6.14-fold more active than sorafenib (3.44±1.50μM, 3.18±1.43μM, 3.24±0.45μM), respectively. The compound 5b showed good activity on VEGFR-2/KDR kinase, and its IC 50 value was 0.72μM. Structure-activity relationships (SARs) and docking studies indicated that replacement of urea group of sorafenib by chalcone ketones improved the cytotoxic activity, and the results suggested that halogen [3-Br, 4-F] and methoxy (substituted on C-3,4,5 or C-2,3,4 position) substitution was benefit for the activity. Copyright © 2016 Elsevier Ltd. All rights reserved.

Quinolactacins A, B and C: novel quinolone compounds from Penicillium sp. EPF-6. II. Physico-chemical properties and structure elucidation.

PubMed

Takahashi, S; Kakinuma, N; Iwai, H; Yanagisawa, T; Nagai, K; Suzuki, K; Tokunaga, T; Nakagawa, A

2000-11-01

Three novel quinolone compounds, quinolactacins A (1), B (2) and C (3), have been found from the fermentation broth of Penicillium sp. EPF-6, a fungus isolated from the larvae of mulberry pyralid (Margaronia pyloalis Welker). The molecular formulas of 1, 2 and 3 were determined to be C16H18N2O2, C15H16N2O2 and C16H18N2O3, respectively by FAB-MS and NMR spectral analyses. The structures of these compounds have a novel quinolone skeleton with a gamma-lactam ring consisting of C12H8N2O2 as the common chromophore.

Relative developmental toxicity of short-chain chlorinated paraffins in Zebrafish (Danio rerio) embryos.

PubMed

Liu, Lihua; Li, Yifan; Coelhan, Mehmet; Chan, Hing Man; Ma, Wanli; Liu, Liyan

2016-12-01

Short-chain chlorinated paraffins (SCCPs) are ubiquitous in the environment and might cause adverse environmental and human health effects. Little is known about the relative toxicity of different SCCP compounds especially during development. The objective of this study was to characterize and compare effects of seven SCCP groups at environmentally relevant levels, using a zebrafish (Danio rerio) model. Observations on malformation, survival rates at 96 h post fertilization (hpf), and hatching rates at 72 hpf indicated that the C 10- groups (C 10 H 18 Cl 4 , 1,2,5,6,9,10-C 10 H 16 Cl 6 and C 10 H 15 Cl 7 ) were more toxic than the C 12- groups (C 12 H 22 Cl 4 , C 12 H 19 Cl 7 and 1,1,1,3,10,12,12,12-C 12 H 18 Cl 8 ) and Cereclor 63L. The C 10- groups were also more potent than C 12- groups and Cereclor 63L in decreasing thyroid hormone levels. Among the three compounds within the C 10- group, the compounds with less chlorine content had stronger effects on sub-lethal malformations but less effects on triiodothyronine (T3) and tetraiodothyronine (T4). Only C 10 H 18 Cl 4 significantly decreased the mRNA expression of tyr, ttr, dio2 and dio3 at a dose-dependent manner suggesting that the specific mode of actions differ with different congeners. The mechanisms of disruption of thyroid status by different SCCPs could be different. C 10 H 18 Cl 4 might inhibit T3 production through the inhibition effect on dio2. These results indicate that SCCP exposure could alter gene expression in the hypothalamic-pituitary-thyroid (HPT) axis and thyroid hormone levels. The mechanisms of disruption of thyroid status by different SCCPs could be different. Our results on the relative developmental toxicities of SCCPs will be useful to reach a better understanding of SCCP toxicity supporting environmental risk evaluation and regulation and used as a guidance for environmental monitoring of SCCPs in the future. Copyright © 2016 Elsevier Ltd. All rights reserved.

Discovery and structure-activity relationship of (1R)-8-chloro-2,3,4,5-tetrahydro-1-methyl-1H-3-benzazepine (Lorcaserin), a selective serotonin 5-HT2C receptor agonist for the treatment of obesity.

PubMed

Smith, Brian M; Smith, Jeffrey M; Tsai, James H; Schultz, Jeffrey A; Gilson, Charles A; Estrada, Scott A; Chen, Rita R; Park, Douglas M; Prieto, Emily B; Gallardo, Charlemagne S; Sengupta, Dipanjan; Dosa, Peter I; Covel, Jon A; Ren, Albert; Webb, Robert R; Beeley, Nigel R A; Martin, Michael; Morgan, Michael; Espitia, Stephen; Saldana, Hazel R; Bjenning, Christina; Whelan, Kevin T; Grottick, Andrew J; Menzaghi, Frederique; Thomsen, William J

2008-01-24

The synthesis and SAR of a novel 3-benzazepine series of 5-HT2C agonists is described. Compound 7d (lorcaserin, APD356) was identified as one of the more potent and selective compounds in vitro (pEC50 values in functional assays measuring [(3)H]phosphoinositol turnover: 5-HT2C = 8.1; 5-HT2A = 6.8; 5-HT2B = 6.1) and was potent in an acute in vivo rat food intake model upon oral administration (ED50 at 6 h = 18 mg/kg). Lorcaserin was further characterized in a single-dose pharmacokinetic study in rat (t1/2 = 3.7 h; F = 86%) and a 28-day model of weight gain in growing Sprague-Dawley rat (8.5% decrease in weight gain observed at 36 mg/kg b.i.d.). Lorcaserin was selected for further evaluation in clinical trials for the treatment of obesity.

Zwitterionic and free forms of arylmethyl Meldrum's acids.

PubMed

Mierina, Inese; Mishnev, Anatoly; Jure, Mara

2015-09-01

C-Alkyl (including C-arylmethyl) derivatives of Meldrum's acids are attractive building blocks in organic synthesis, mainly due to the unusually high acidity of the resulting compounds. Three examples, namely 5-[4-(diethylamino)benzyl]-2,2-dimethyl-1,3-dioxane-4,6-dione, C17H23NO4, (I), 2,2-dimethyl-5-(2,4,6-trimethoxybenzyl)-1,3-dioxane-4,6-dione, C16H20O7, (II), and 5-(4-hydroxy-3,5-dimethoxybenzyl)-2,2-dimethyl-1,3-dioxane-4,6-dione, C15H18O7, (III), have been synthesized, characterized by NMR and IR spectroscopy, and studied by single-crystal X-ray structure analysis. The nature of the different substituents resulted in remarkable differences in both the molecular conformations and the crystal packing arrangements. The presence of a substituent with a basic centre in compound (I) leads to the formation of an inner salt accompanied by drastic changes in the conformation of the 1,3-dioxane-4,6-dione fragment. By virtue of strong N-H···O hydrogen bonds, the residues are assembled into infinite chains with the graph-set descriptor C(10). Compound (II) contains methoxy groups in both the ortho- and para-positions of the arylmethyl fragment. Because of the absence of classical hydrogen-bond donors in this structure, the crystal packing is controlled by van der Waals forces and weak C-H···O interactions. Compound (III) contains methoxy groups in both meta-positions and a hydroxy group in the para-position. Supramolecular tetrameric synthons which comprise hydrogen-bonded dimers associated into tetramers through π-π interactions of overlapping benzene rings were observed.

A novel mixed-metal borate with large [B12O18(OH)6]6- motif: Synthesis, structure and property

NASA Astrophysics Data System (ADS)

Wei, Li; Pan, Jie; Xue, Zhen-Zhen; Wang, Guo-Ming; Wang, Ying-Xia

2018-01-01

A new mixed-metal polyborate, Na5Li[B12O18(OH)6]·2H2O (1), has been synthesized using solvothermal method and characterized by IR spectroscopy, thermogravimetric analysis, UV-Vis spectroscopy, powder and single-crystal X-ray diffraction, respectively. It crystallizes in the trigonal space group R-3c (No. 167) with unit cell parameters of a = b = 9.6767(6) Å, c = 36.358(5) Å, and Z = 6. Its structure features unprecedented 3D framework constructed from novel honeycomb-shaped inorganic Na-O sheets with unique 12-MR sodium rings and supramolecular polyborate 2D layers of lithium-centered [B12O18(OH)6]6-. UV-Vis spectral characterization indicates that compound 1 is a wide-band-gap semiconductor.

Determination of selected quaternary ammonium compounds by liquid chromatography with mass spectrometry. Part II. Application to sediment and sludge samples in Austria.

PubMed

Martínez-Carballo, Elena; González-Barreiro, Carmen; Sitka, Andrea; Kreuzinger, Norbert; Scharf, Sigrid; Gans, Oliver

2007-03-01

Soxhlet extraction and high-performance liquid chromatography (HPLC) coupled to tandem mass spectrometry detection (MS/MS) was used for the determination of selected quaternary ammonium compounds (QACs) in solid samples. The method was applied for the determination of alkyl benzyl, dialkyl and trialkyl quaternary ammonium compounds in sediment and sludge samples in Austria. The overall method quantification limits range from 0.6 to 3 microg/kg for sediments and from 2 to 5 microg/kg for sewage sludges. Mean recoveries between 67% and 95% are achieved. In general sediments were especially contaminated by C12 chain benzalkonium chloride (BAC-C12) as well as by the long C-chain dialkyldimethylammonium chloride (DDAC-C18) with a maximum concentration of 3.6 mg/kg and 2.1mg/kg, respectively. Maxima of 27 mg/kg for DDAC-C10, 25 mg/kg for BAC-C12 and 23 mg/kg for BAC-C14 were determined for sludge samples. The sums of the 12 selected target compounds range from 22 mg/kg to 103 mg/kg in the sludge samples.

Compounds from the Fruits of the Popular European Medicinal Plant Vitex agnus-castus in Chemoprevention via NADP(H):Quinone Oxidoreductase Type 1 Induction.

PubMed

Li, Shenghong; Qiu, Shengxiang; Yao, Ping; Sun, Handong; Fong, Harry H S; Zhang, Hongjie

2013-01-01

As part of our continuing efforts in the search for potential biologically active compounds from medicinal plants, we have isolated 18 compounds including two novel nitrogen containing diterpenes from extracts of the fruits of Vitex agnus-castus. These isolates, along with our previously obtained novel compound vitexlactam A (1), were evaluated for potential biological effects, including cancer chemoprevention. Chemically, the nitrogenous isolates were found to be two labdane diterpene alkaloids, each containing an α , β -unsaturated γ -lactam moiety. Structurally, they were elucidated to be 9 α -hydroxy-13(14)-labden-16,15-amide (2) and 6 β -acetoxy-9 α -hydroxy-13(14)-labden-15,16-amide (3), which were named vitexlactams B and C, respectively. The 15 known isolates were identified as vitexilactone (4), rotundifuran (5), 8-epi-manoyl oxide (6), vitetrifolin D (7), spathulenol (8), cis-dihydro-dehydro-diconiferylalcohol-9-O- β -D-glucoside (9), luteolin-7-O-glucoside (10), 5-hydroxy-3,6,7,4'-tetramethoxyflavone (11), casticin (12), artemetin (13), aucubin (14), agnuside (15), β -sitosterol (16), p-hydroxybenzoic acid (17), and p-hydroxybenzoic acid glucose ester (18). All compound structures were determined/identified on the basis of 1D and/or 2D NMR and mass spectrometry techniques. Compounds 6, 8, 9, and 18 were reported from a Vitex spieces for the first time. The cancer chemopreventive potentials of these isolates were evaluated for NADP(H):quinone oxidoreductase type 1 (QR1) induction activity. Compound 7 demonstrated promising QR1 induction effect, while the new compound vitexlactam (3) was only slightly active.

Compounds from the Fruits of the Popular European Medicinal Plant Vitex agnus-castus in Chemoprevention via NADP(H):Quinone Oxidoreductase Type 1 Induction

PubMed Central

Li, Shenghong; Qiu, Shengxiang; Yao, Ping; Sun, Handong; Fong, Harry H. S.; Zhang, Hongjie

2013-01-01

As part of our continuing efforts in the search for potential biologically active compounds from medicinal plants, we have isolated 18 compounds including two novel nitrogen containing diterpenes from extracts of the fruits of Vitex agnus-castus. These isolates, along with our previously obtained novel compound vitexlactam A (1), were evaluated for potential biological effects, including cancer chemoprevention. Chemically, the nitrogenous isolates were found to be two labdane diterpene alkaloids, each containing an α, β-unsaturated γ-lactam moiety. Structurally, they were elucidated to be 9α-hydroxy-13(14)-labden-16,15-amide (2) and 6β-acetoxy-9α-hydroxy-13(14)-labden-15,16-amide (3), which were named vitexlactams B and C, respectively. The 15 known isolates were identified as vitexilactone (4), rotundifuran (5), 8-epi-manoyl oxide (6), vitetrifolin D (7), spathulenol (8), cis-dihydro-dehydro-diconiferylalcohol-9-O-β-D-glucoside (9), luteolin-7-O-glucoside (10), 5-hydroxy-3,6,7,4′-tetramethoxyflavone (11), casticin (12), artemetin (13), aucubin (14), agnuside (15), β-sitosterol (16), p-hydroxybenzoic acid (17), and p-hydroxybenzoic acid glucose ester (18). All compound structures were determined/identified on the basis of 1D and/or 2D NMR and mass spectrometry techniques. Compounds 6, 8, 9, and 18 were reported from a Vitex spieces for the first time. The cancer chemopreventive potentials of these isolates were evaluated for NADP(H):quinone oxidoreductase type 1 (QR1) induction activity. Compound 7 demonstrated promising QR1 induction effect, while the new compound vitexlactam (3) was only slightly active. PMID:23662135

C(18) columns for the simultaneous determination of oxytetracycline and its related substances by reversed-phase high performance liquid chromatography and UV detection.

PubMed

Smyrniotakis, C G; Archontaki, Helen A

2007-01-17

Simultaneous determination of oxytetracycline, 4-epioxytetracycline, alpha-apooxytetracycline, tetracycline and beta-apooxytetracycline on C(18) columns has been accomplished using a high performance liquid chromatographic method with UV detection. Separation was achieved on a Hypersil BDS RP-C(18) column (250 mm x 4.6 mm) and on a Waters C(18) Symmetry column (150 mm x 3.9mm), 5 microm particle size each. These columns were equilibrated with mobile phases consisted of methanol-acetonitrile-0.1M phosphate buffer pH 8.0 (12.5:12.5:75, v/v/v) and (15:15:70, v/v/v), respectively. The flow rate was 1.0 ml/min and the total elution time was 15 and 5 min, respectively. Both methods were applied to oxytetracycline raw material, human and veterinary formulations, where the excipients did not interfere. External standard calibration curves were linear for 4-epioxytetracycline, oxytetracycline, alpha-apooxytetracycline, tetracycline and beta-apooxytetracycline in the concentration range of 0.27-200 microM, 0.05-200 microM, 0.03-200 microM, 0.35-200 microM and 0.20-200 microM on column A and 0.08-200 microM, 0.15-200 microM, 0.09-200 microM, 0.25-200 microM and 0.47-200 microM on column B, respectively. Day-to-day relative standard deviation of the determination for every component was less than 3%. Concerning the first column, limits of detection and quantification of the above compounds were in the concentration ranges of 10-106 nM and 30-352 nM, respectively, whereas on the second column these ranges became 27-144 nM and 81-475 nM, respectively. Recovery of the separated compounds was 95-105%.

Antidiabetic compounds from Sarracenia purpurea used traditionally by the Eeyou Istchee Cree First Nation.

PubMed

Muhammad, Asim; Guerrero-Analco, Jose A; Martineau, Louis C; Musallam, Lina; Madiraju, Padma; Nachar, Abir; Saleem, Ammar; Haddad, Pierre S; Arnason, John T

2012-07-27

Through ethnobotanical surveys, the CIHR Team in Aboriginal Antidiabetic Medicines identified 17 boreal forest plants stemming from the pharmacopeia of the Cree First Nations of Eeyou Istchee (James Bay region of Northern Quebec) that were used traditionally against diabetes symptoms. The leaves of Sarracenia purpurea (pitcher plant), one of the identified Cree plants, exhibited marked antidiabetic activity in vitro by stimulating glucose uptake in C2C12 mouse muscle cells and by reducing glucose production in H4IIE rat liver cells. Fractionation guided by glucose uptake in C2C12 cells resulted in the isolation of 11 compounds from this plant extract, including a new phenolic glycoside, flavonoid glycosides, and iridoids. Compounds 6 (isorhamnetin-3-O-glucoside), 8 [kaempferol-3-O-(6″-caffeoylglucoside], and 11 (quercetin-3-O-galactoside) potentiated glucose uptake in vitro, which suggests they represent active principles of S. purpurea (EC(50) values of 18.5, 13.8, and 60.5 μM, respectively). This is the first report of potentiation of glucose uptake by compounds 6 and 8, while compound 11 (isolated from Vaccinium vitis) was previously shown to enhance glucose uptake. Treatment of H4IIE liver cells with the new compound 1, 6'-O-caffeoylgoodyeroside, decreased hepatic glucose production by reducing glucose-6-phosphatase enzymatic activity (IC(50) = 13.6 μM), which would contribute to lowering glycemia and to the antidiabetic potential of S. purpurea.

Rapid LC-MS/MS profiling of protein amino acids and metabolically related compounds for large-scale assessment of metabolic phenotypes.

PubMed

Gu, Liping; Jones, A Daniel; Last, Robert L

2012-01-01

Amino acids extracted from a biological matrix can be resolved and measured using a 6-min per sample method through high-performance liquid chromatography with a short C18 column and rapid gradient using the ion-pairing reagent perfluoroheptanoic acid. LC-tandem mass spectrometry with multiple reaction monitoring (MRM) transitions selective for each compound allows simultaneous quantification of the 20 proteinogenic amino acids and 5 metabolically related compounds. Distinct MRM transitions were also established for selective detection of the isomers leucine/isoleucine and threonine/homoserine.

Antimicrobial and cytotoxic constituents from native Cameroonian medicinal plant Hypericum riparium.

PubMed

Tala, Michel Feussi; Talontsi, Ferdinand Mouafo; Zeng, Guang-Zhi; Wabo, Hippolyte Kamdem; Tan, Ning-Hua; Spiteller, Michael; Tane, Pierre

2015-04-01

Bioassay guided fractionation of Hypericum riparium leaves extract has resulted in the isolation and characterization of three new compounds namely chipericumin E (1), hyperenone C (3), and hyperixanthone (5), together with twenty known compounds. Their structures were elucidated based on comprehensive interpretation of spectroscopic and spectrometric data. Compounds 1-4, and 6-8 displayed moderate antibacterial activity against methicillin-resistant Staphylococcus aureus (MRSA) and cytotoxic effects on the human gastric cell line BGC-823 with IC50 values ranging from 6.54 to 18.50μM. Copyright © 2015 Elsevier B.V. All rights reserved.

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.

A chalcone showing positional disorder, two related diarylcyclohexenones showing enantiomeric disorder and a related hydroxyterphenyl, all derived from simple carbonyl precursors.

PubMed

Salian, Vinutha V; Narayana, Badiadka; Yathirajan, Hemmige S; Akkurt, Mehmet; Çelik, Ömer; Ersanlı, Cem Cüneyt; Glidewell, Christopher

2015-07-01

Four compounds are reported, all of which lie along a versatile reaction pathway which leads from simple carbonyl compounds to terphenyls. (2E)-1-(2,4-Dichlorophenyl)-3- [4-(prop-1-en-2-yl)phenyl]prop-2-en-1-one, C18H14Cl2O, (I), prepared from 4-(prop-1-en-2-yl)benzaldehyde and 2,4-dichloroacetophenone, exhibits disorder over two sets of atomic sites having occupancies of 0.664 (6) and 0.336 (6). The related chalcone (2E)-3-(4-chlorophenyl)-1-(4-fluorophenyl)prop-2-en-1-one reacts with acetone to produce (5RS)-3-(4-chlorophenyl)-5-[4-(propan-2-yl)phenyl]cyclohex-2-en-1-one, C21H21ClO, (II), which exhibits enantiomeric disorder with occupancies at the reference site of 0.662 (4) and 0.338 (4) for the (5R) and (5S) forms; the same chalcone reacts with methyl 3-oxobutanoate to give methyl (1RS,6SR)-4-(4-chlorophenyl)-6-[4-(propan-2-yl)phenyl]-2-oxocyclohex-3-ene-1-carboxylate, C23H23ClO3, (III), where the reference site contains both (1R,6S) and (1S,6R) forms with occupancies of 0.923 (3) and 0.077 (3), respectively. Oxidation, using 2,3-dichloro-5,6-dicyano-1,4-benzoquinone, of ethyl (1RS,6SR)-6-(4-bromophenyl)-4-(4-fluorophenyl)-2-oxocyclohex-3-ene-1-carboxylate, prepared in a similar manner to (II) and (III), produces ethyl 4''-bromo-4-fluoro-5'-hydroxy-1,1':3',1''-terphenyl-4'-carboxylate, C21H16BrFO3, (IV), which crystallizes with Z' = 2 in the space group P-1. There are no significant intermolecular interactions in the structures of compounds (I) and (II), but for the major disorder component of compound (III), the molecules are linked into sheets by a combination of C-H...O and C-H...π(arene) hydrogen bonds. The two independent molecules of compound (IV) form two different centrosymmetric dimers, one built from inversion-related pairs of C-H...O hydrogen bonds and the other from inversion-related pairs of C-H...π(arene) hydrogen bonds. Comparisons are made with related compounds.

Rust-Inhibited Nonreactive Perfluorinated Polymer Greases

DTIC Science & Technology

Perfluoroalkylpolyether fluids thickened with polytetrafluoroethylene were studied in connection with the development of rust-inhibited chemically...dimethyloctadecylbenzyl ammonium bentonite + sodium nitrate imparts very effective rust-preventive properties to perfluoro polymer grease mixtures. Data are

Parahydrogen-induced polarization transfer to 19F in perfluorocarbons for 19F NMR spectroscopy and MRI.

PubMed

Plaumann, Markus; Bommerich, Ute; Trantzschel, Thomas; Lego, Denise; Dillenberger, Sonja; Sauer, Grit; Bargon, Joachim; Buntkowsky, Gerd; Bernarding, Johannes

2013-05-10

Fluorinated substances are important in chemistry, industry, and the life sciences. In a new approach, parahydrogen-induced polarization (PHIP) is applied to enhance (19)F MR signals of (perfluoro-n-hexyl)ethene and (perfluoro-n-hexyl)ethane. Unexpectedly, the end-standing CF3 group exhibits the highest amount of polarization despite the negligible coupling to the added protons. To clarify this non-intuitive distribution of polarization, signal enhancements in deuterated chloroform and acetone were compared and (19)F-(19)F NOESY spectra, as well as (19)F T1 values were measured by NMR spectroscopy. By using the well separated and enhanced signal of the CF3 group, first (19)F MR images of hyperpolarized linear semifluorinated alkenes were recorded. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

4-(4-Bromo-phen-yl)-1-(2,6-difluoro-benz-yl)-3-(3,4,5-trimeth-oxy-phen-yl)-1H-1,2,4-triazole-5(4H)-thione.

PubMed

Fun, Hoong-Kun; Ooi, Chin Wei; Chandrakantha, B; Isloor, Arun M; Shetty, Prakash

2012-01-01

In the title compound, C(24)H(20)BrF(2)N(3)O(3)S, the triazole ring (r.m.s. deviation = 0.0107 Å) makes dihedral angles of 28.18 (14), 63.76 (14) and 77.01 (18)°, respectively, with the trimeth-oxy-, bromo-, and difluoro-substituted benzene rings. The C atoms of the meta meth-oxy groups are roughly coplanar with their ring [displacements = -0.289 (4) and 0.083 (7) Å], whereas the C atom of the para group is displaced [1.117 (3) Å]. In the crystal, inversion dimers linked by two pairs of C-H⋯O hydrogen bonds occur. The ring motif of the two hydrogen bonds to their symmetry-generated O-atom acceptors is R(2) (2)(8).

Synthesis of a potent and selective (18)F-labeled delta-opioid receptor antagonist derived from the Dmt-Tic pharmacophore for positron emission tomography imaging.

PubMed

Ryu, Eun Kyoung; Wu, Zhanhong; Chen, Kai; Lazarus, Lawrence H; Marczak, Ewa D; Sasaki, Yusuke; Ambo, Akihiro; Salvadori, Severo; Ren, Chuancheng; Zhao, Heng; Balboni, Gianfranco; Chen, Xiaoyuan

2008-03-27

Identification and pharmacological characterization of two new selective delta-opioid receptor antagonists, derived from the Dmt-Tic pharmacophore, of potential utility in positron emission tomography (PET) imaging are described. On the basis of its high delta selectivity, H-Dmt-Tic--Lys(Z)-OH (reference compound 1) is a useful starting point for the synthesis of (18)F-labeled compounds prepared by the coupling of N-succinimidyl 4-[ (18)F]fluorobenzoate ([(18)F]SFB) with Boc-Dmt-Tic--Lys(Z)-OH under slightly basic conditions at 37 degrees C for 15 min, deprotection with TFA, and HPLC purification. The total synthesis time was 120 min, and the decay-corrected radiochemical yield of [(18)F]- 1 was about 25-30% ( n = 5) starting from [(18)F]SFB ( n = 5) with an effective specific activity about 46 GBq/micromol. In vitro autoradiography studies showed prominent uptake of [ (18)F]- 1 in the striatum and cortex with significant blocking by 1 and UFP-501 (selective delta-opioid receptor antagonist), suggesting high specific binding of [(18)F]- 1 to delta-opioid receptors. Noninvasive microPET imaging studies revealed the absence of [(18)F]- 1 in rat brain, since it fails to cross the blood-brain barrier. This study demonstrates the suitability of [ (18)F]- 1 for imaging peripheral delta-opioid receptors.

Impurity and Defect Characterization in Epitaxial GaAs, InP and the Ternary and Quaternary Compound Semiconductors.

DTIC Science & Technology

1982-11-02

Wolfe, Phys. Rev. Lett. 27, 988 (1971). 5. H.R. Fetterman , D.M. Larsen, G.E. Stillman, P.E. Tannenwald, and J. Waldman, Phys.Rev. Lett. 26. 975(1971). 6...Kirkman, P.E. Simmonds, and R.A. Stradling, J. Phys. C., Solid State Phys. 8, 530 (1975). 18. H.R. Fetterman , J. Waldman and C.M. Wolfe, Solid State Commun

Effect of C282Y genotype on self-reported musculoskeletal complications in hereditary hemochromatosis.

PubMed

Camacho, António; Funck-Brentano, Thomas; Simão, Márcio; Cancela, Leonor; Ottaviani, Sébastien; Cohen-Solal, Martine; Richette, Pascal

2015-01-01

Arthropathy that mimics osteoarthritis (OA) and osteoporosis (OP) is considered a complication of hereditary hemochromatosis (HH). We have limited data comparing OA and OP prevalence among HH patients with different hemochromatosis type 1 (HFE) genotypes. We investigated the prevalence of OA and OP in patients with HH by C282Y homozygosity and compound heterozygosity (C282Y/H63D) genotype. A total of 306 patients with HH completed a questionnaire. Clinical and demographic characteristics and presence of OA, OP and related complications were compared by genotype, adjusting for age, sex, body mass index (BMI), current smoking and menopausal status. In total, 266 of the 306 patients (87%) were homozygous for C282Y, and 40 (13%) were compound heterozygous. The 2 groups did not differ by median age [60 (interquartile range [IQR] 53 to 68) vs. 61 (55 to 67) years, P=0.8], sex (female: 48.8% vs. 37.5%, P=0.18) or current smoking habits (12.4% vs. 10%, P=0.3). As compared with compound heterozygous patients, C282Y homozygous patients had higher median serum ferritin concentration at diagnosis [1090 (IQR 610 to 2210) vs. 603 (362 to 950) µg/L, P<0.001], higher median transferrin saturation [80% (IQR 66 to 91%) vs. 63% (55 to 72%), P<0.001]) and lower median BMI [24.8 (22.1 to 26.9) vs. 26.2 (23.5 to 30.3) kg/m2, P<0.003]. The overall prevalence of self-reported OA was significantly higher with C282Y homozygosity than compound heterozygosity (53.4% vs. 32.5%; adjusted odds ratio [aOR] 2.4 [95% confidence interval 1.2-5.0]), as was self-reported OP (25.6% vs. 7.5%; aOR 3.5 [1.1-12.1]). Patients with C282Y homozygosity may be at increased risk of musculoskeletal complications of HH.

Effect of C282Y Genotype on Self-Reported Musculoskeletal Complications in Hereditary Hemochromatosis

PubMed Central

Simão, Márcio; Cancela, Leonor; Ottaviani, Sébastien; Cohen-Solal, Martine; Richette, Pascal

2015-01-01

Objective Arthropathy that mimics osteoarthritis (OA) and osteoporosis (OP) is considered a complication of hereditary hemochromatosis (HH). We have limited data comparing OA and OP prevalence among HH patients with different hemochromatosis type 1 (HFE) genotypes. We investigated the prevalence of OA and OP in patients with HH by C282Y homozygosity and compound heterozygosity (C282Y/H63D) genotype. Methods A total of 306 patients with HH completed a questionnaire. Clinical and demographic characteristics and presence of OA, OP and related complications were compared by genotype, adjusting for age, sex, body mass index (BMI), current smoking and menopausal status. Results In total, 266 of the 306 patients (87%) were homozygous for C282Y, and 40 (13%) were compound heterozygous. The 2 groups did not differ by median age [60 (interquartile range [IQR] 53 to 68) vs. 61 (55 to 67) years, P=0.8], sex (female: 48.8% vs. 37.5%, P=0.18) or current smoking habits (12.4% vs. 10%, P=0.3). As compared with compound heterozygous patients, C282Y homozygous patients had higher median serum ferritin concentration at diagnosis [1090 (IQR 610 to 2210) vs. 603 (362 to 950) µg/L, P<0.001], higher median transferrin saturation [80% (IQR 66 to 91%) vs. 63% (55 to 72%), P<0.001]) and lower median BMI [24.8 (22.1 to 26.9) vs. 26.2 (23.5 to 30.3) kg/m2, P<0.003]. The overall prevalence of self-reported OA was significantly higher with C282Y homozygosity than compound heterozygosity (53.4% vs. 32.5%; adjusted odds ratio [aOR] 2.4 [95% confidence interval 1.2–5.0]), as was self-reported OP (25.6% vs. 7.5%; aOR 3.5 [1.1–12.1]). Conclusion Patients with C282Y homozygosity may be at increased risk of musculoskeletal complications of HH. PMID:25822977

Synthesis of novel heterocyclic ring-fused 18β-glycyrrhetinic acid derivatives with antitumor and antimetastatic activity.

PubMed

Gao, Cheng; Dai, Fu-Jun; Cui, Hai-Wei; Peng, Shi-Hong; He, Yuan; Wang, Xue; Yi, Zheng-Fang; Qiu, Wen-Wei

2014-08-01

Glycyrrhetinic acid (GA) is one of the most important triterpenoic acids shows many pharmacological effects, especially antitumor activity. GA triggers apoptosis in various tumor cell lines. However, the antitumor activity of GA is weak, thus the synthesis of new synthetic analogs with enhanced potency is needed. By introducing various five-member fused heterocyclic rings at C-2 and C-3 positions, 18 novel GA derivatives were obtained. These compounds were evaluated for their inhibitory activity against the growth of eight different tumor cell lines using a SRB assay. The most active compound 37 showed IC50 between 5.19 and 11.72 μm, which was about 11-fold more potent than the lead compound GA. An apoptotic effect of GA and 37 was determined using flow cytometry and trypan blue exclusion assays. We also demonstrated here for the first time that GA and the synthetic derivatives exhibited inhibitory effect on migration of the tested tumor cells, especially 37 which was about 20-fold more potent than GA on antimetastatic activity. © 2014 John Wiley & Sons A/S.

Synthesis, spectral characterization, and single crystal structure studies of (2-nitro-ethene-1,1-diyl)-bis-((4-isopropyl-benzyl)sulfane)

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

Sakthikumar, L., E-mail: lsakthisbk@gmail.com; Mahalakshmy, R.; Bhargavi, G.

2015-12-15

The title compound (2-nitro-ethene-1,1-diyl)-bis-(4-isopropylbenzyl)sulfane) (5), was synthesised using a two step process. The structure of the product (5) was established by UV, FT-IR, {sup 1}H NMR, {sup 13}C NMR, C,H,N analysis, LC-MS and single crystal X-ray diffraction analysis. The single crystal of the title compound (5) was crystallized in Monoclinic with the space group of P21/c. The crystal exhibit the following unit cell parameters a = 12.8165(18), b = 6.1878(6), c = 27.082(4) Å, β = 90.705(17)°, V = 2147.6(5) A{sup 3}, Z = 4, D{sub x} = 1.242 Mg/m{sup 3} and the molecular formula of C{sub 22}H{sub 27}N{sub 1}O{submore » 2}S{sub 2} was found. The final R value was 0.0776. The crystal structure is stabilized by an interesting intramolecular push and pull five membered electrocyclic interaction between the O1–N1–C2–C1–S1- and via the intermolecular H-bonding interaction between C2–H2···O2.« less

Rapid trace level determination of sulfonamide residues in honey with online extraction using short C-18 column by high-performance liquid chromatography with fluorescence detection.

PubMed

Sajid, Muhammad; Na, Na; Safdar, Muhammad; Lu, Xin; Ma, Lin; He, Lan; Ouyang, Jin

2013-11-01

A sensitive and inexpensive quantification method with online extraction using a short C-18 column for sulfonamide residues in honey by high performance liquid chromatography with fluorescence detector was developed and validated. In sample preparation, acid hydrolysis was used to break the N-glycoside bond between the honey sugar and sulfonamide drugs and derivatization of sulfonamide residues with fluorescamine was conducted at pH 3.5 using a citrate buffer (0.5M) in the honey matrix. The chromatography was carried out on Zorbax Extended C-18 (250mm×4.6mm; 5μm) column, using a mixture of acetonitrile and an acetate buffer (pH 4.50, 20mM) as a mobile phase. A Zorbax Extended C-18 (12mm×4.6mm; 5μm) column was used for online extraction of fifteen sulfonamide residues from honey sample with the help of a two position valve. The limit of quantification of sulfonamide residues in honey was less than 3ngg(-1), and the percentage recovery of study compounds in spiked honey sample was from 80% for sulfacetamide to 100% of sulfachloropyridazine. The developed method has excellent linearity for all studied sulfonamides with a correlation coefficient 0.993. Copyright © 2013 Elsevier B.V. All rights reserved.

Synthesis, crystal structure and antioxidant evaluation of C-4-acetamidophenylcalix[4]pyrogallolarene

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

Abosadiya, Hamza M.; Hasbullah, Siti Aishah; Yamin, Bohari M.

2015-09-25

C-4-acetamidophenylcalix[4]pyrogallolarene was synthesized by an acid catalyzed condensation reaction of pyrogallol with 4-acetamidobenzaldehyde. The compound was characterized by IR, {sup 1}H and {sup 13}C NMR spectroscopy. Single crystal X-ray analysis revealed that the molecule crystallized in a triclinic system with space group Pī and the unit cell dimensions a= 12.2948(16) Å, b= 13.4423(17) Å, c= 13.5906(18) Å, α =107.549(4)°, β =102.034(4)°, γ =90.535(4)°, Z= 1 and V= 2088.2(5) Å{sup 3}. The macrocyclic calix adopts a chair (C{sub 2h}) conformation and the molecule is associated with eight DMSO molecules of crystallization. Antioxidant test by DPPH method showed that the compound exhibitsmore » good antioxidant activity of about 72%.« less

The Chemical Composition of Essential Oils from Cinnamomum camphora and Their Insecticidal Activity against the Stored Product Pests.

PubMed

Guo, Shanshan; Geng, Zhufeng; Zhang, Wenjuan; Liang, Junyu; Wang, Chengfang; Deng, Zhiwei; Du, Shushan

2016-11-04

To investigate the chemical composition and insecticidal activity of the essential oils of certain Chinese medicinal herbs and spices, the essential oils were extracted from the stem barks, leaves, and fruits of Cinnamomum camphora (L.) Presl, which were found to possess strong fumigant toxicity against Tribolium castaneum and Lasioderma serricorne adults. The essential oils of the plants were extracted by the method of steam distillation using a Clavenger apparatus. Their composition was determined by gas chromatography/mass spectrometric (GC-MS) analyses (HP-5MS column), and their insecticidal activity was measured by seal-spaced fumigation. D-camphor (51.3%), 1,8-cineole (4.3%), and α-terpineol (3.8%), while D-camphor (28.1%), linalool (22.9%), and 1,8-cineole (5.3%) were the main constituents of its fruits. The essential oils of the C. camphora all showed fumigant and contact toxicity. Other compounds exhibited various levels of bioactivities. The results indicate that the essential oils of C. camphora and its individual compounds can be considered a natural resource for the two stored-product insect management.

Cytotoxic Halogenated Macrolides and Modified Peptides from the Apratoxin-Producing Marine Cyanobacterium Lyngbya bouillonii from Guam

PubMed Central

Matthew, Susan; Salvador, Lilibeth A.; Schupp, Peter J.; Paul, Valerie J.; Luesch, Hendrik

2010-01-01

Collections of the marine cyanobacterium Lyngbya bouillonii from shallow patch reefs in Apra Harbor, Guam, afforded three hitherto undescribed analogues of the glycosidic macrolide lyngbyaloside, namely 2-epi-lyngbyaloside (1) and the regioisomeric 18E- and 18Z–lyngbyalosides C (2 and 3). Concurrently we discovered two new analogues of the cytoskeletal actin-disrupting lyngbyabellins, 27-deoxylyngbyabellin A (4) and lyngbyabellin J (5), a novel macrolide of the laingolide family, laingolide B (6), and a linear modified peptide, lyngbyapeptin D (7), along with known lyngbyabellins A and B, lyngbyapeptin A, and lyngbyaloside. The structures of 1–7 were elucidated by a combination of NMR spectroscopic and mass spectrometric analysis. Compounds 1–6 were either brominated (1–3) or chlorinated (4–6), consistent with halogenation being a hallmark of many marine natural products. All extracts derived from these L. bouillonii collections were highly cytotoxic due to the presence of apratoxin A or also apratoxin C. Compounds 1–5 showed weak to moderate cytotoxicity to HT29 colorectal adenocarcinoma and HeLa cervical carcinoma cells. PMID:20704304

Quorum sensing inhibitors from marine bacteria Oceanobacillus sp. XC22919.

PubMed

Chen, Xiaochun; Chen, Jianwei; Yan, Yinchun; Chen, Su; Xu, Xuewei; Zhang, Huawei; Wang, Hong

2018-02-12

In this study, three active compounds isolated from Oceanobacillus sp. XC22919 were identified as 2-methyl-N-(2'-phenylethyl) butyramide (1), 3-methyl-N-(2'-phenylethyl)-butyramide (2) and benzyl benzoate (3), and were first reported to exhibit the apparent quorum sensing inhibitory activities against C. violaceum 026 and P. aeruginosa. Compounds 1-3 inhibited violacein production of C. violaceum 026 by 10.5-55.7, 11.2-55.7, and 27.2%-95.7%, respectively, and inhibited pyocyanin production of P. aeruginosa by 1.7-50.8, 39.1-90.7, and 57.2%-98.7%, respectively. The azocasein-degrading proteolytic rates of P. aeruginosa were observed by 13.4-31.5, 13.4-28.8, and 11.3%-21.1%, respectively. With respect to elastase, the range of inhibition of activity of compounds 1-3 was 2.1-30.3, 4.2-18.2, and 8.9%-15.7%, respectively. Compounds 1 and 3 also showed a concentration-dependent attenuation in biofilm formation, with the maximum of 50.6% inhibition, and 37.7% inhibition at 100 μg/mL, respectively.

Comparative evaluation of maceration and ultrasonic-assisted extraction of phenolic compounds from fresh olives.

PubMed

Deng, Junlin; Xu, Zhou; Xiang, Chunrong; Liu, Jing; Zhou, Lijun; Li, Tian; Yang, Zeshen; Ding, Chunbang

2017-07-01

Ultrasonic-assisted extraction (UAE) and maceration extraction (ME) were optimized using response surface methodology (RSM) for total phenolic compounds (TPC) from fresh olives. The main phenolic compounds and antioxidant activity of TPC were also investigated. The optimized result for UAE was 22mL/g of liquid-solid ratio, 47°C of extraction temperature and 30min of extraction time, 7.01mg/g of yielding, and for ME was 24mL/g of liquid-solid ratio, 50°C of extraction temperature and 4.7h of extraction time, 5.18mg/g of yielding. The HPLC analysis revealed that the extracts by UAE and ME possessed 14 main phenolic compounds, and UAE exhibited more amounts of all phenols than ME. The most abundant phenolic compounds in olive extracts were hydroxytyrosol, oleuropein and rutin. Both extracts showed excellent antioxidant activity in a dose-dependent manner. Taken together, UAE could effectively increase the yield of phenolic compounds from olives. In addition these phenolic compounds could be used as a potential source of natural antioxidants. Copyright © 2017 Elsevier B.V. All rights reserved.

Molecular composition of particulate matter emissions from dung and brushwood burning household cookstoves in Haryana, India

NASA Astrophysics Data System (ADS)

Fleming, Lauren T.; Lin, Peng; Laskin, Alexander; Laskin, Julia; Weltman, Robert; Edwards, Rufus D.; Arora, Narendra K.; Yadav, Ankit; Meinardi, Simone; Blake, Donald R.; Pillarisetti, Ajay; Smith, Kirk R.; Nizkorodov, Sergey A.

2018-02-01

Emissions of airborne particles from biomass burning are a significant source of black carbon (BC) and brown carbon (BrC) in rural areas of developing countries where biomass is the predominant energy source for cooking and heating. This study explores the molecular composition of organic aerosols from household cooking emissions with a focus on identifying fuel-specific compounds and BrC chromophores. Traditional meals were prepared by a local cook with dung and brushwood-fueled cookstoves in a village in Palwal district, Haryana, India. Cooking was done in a village kitchen while controlling for variables including stove type, fuel moisture, and meal. Fine particulate matter (PM2.5) emissions were collected on filters, and then analyzed via nanospray desorption electrospray ionization-high-resolution mass spectrometry (nano-DESI-HRMS) and high-performance liquid chromatography-photodiode array-high-resolution mass spectrometry (HPLC-PDA-HRMS) techniques. The nano-DESI-HRMS analysis provided an inventory of numerous compounds present in the particle phase. Although several compounds observed in this study have been previously characterized using gas chromatography methods a majority of the species in the nano-DESI spectra were newly observed biomass burning compounds. Both the stove (chulha or angithi) and the fuel (brushwood or dung) affected the composition of organic aerosols. The geometric mean of the PM2.5 emission factor and the observed molecular complexity increased in the following order: brushwood-chulha (7.3 ± 1.8 g kg-1 dry fuel, 93 compounds), dung-chulha (21.1 ± 4.2 g kg-1 dry fuel, 212 compounds), and dung-angithi (29.8 ± 11.5 g kg-1 dry fuel, 262 compounds). The mass-normalized absorption coefficient (MACbulk) for the organic-solvent extractable material for brushwood PM2.5 was 3.7 ± 1.5 and 1.9 ± 0.8 m2 g-1 at 360 and 405 nm, respectively, which was approximately a factor of two higher than that for dung PM2.5. The HPLC-PDA-HRMS analysis showed that, regardless of fuel type, the main chromophores were CxHyOz lignin fragments. The main chromophores accounting for the higher MACbulk values of brushwood PM2.5 were C8H10O3 (tentatively assigned to syringol), nitrophenols C8H9NO4, and C10H10O3 (tentatively assigned to methoxycinnamic acid).

2-[4-(4,5-Dihydro-1H-pyrrol-2-yl)phen­yl]-4,5-dihydro-1H-imidazole

PubMed Central

Kia, Reza; Fun, Hoong-Kun; Kargar, Hadi

2008-01-01

The mol­ecule of the title compound, C12H14N4, lies about a crystallographic inversion centre. The five- and six-membered rings are twisted from each other, forming a dihedral angle of 18.06 (7)°. In the crystal structure, neighbouring mol­ecules are linked by inter­molecular N—H⋯N hydrogen bonds into one-dimensional infinite chains forming 18-membered rings with R 2 2(18) motifs. The crystal structure is further stabilized by weak inter­molecular π–π stacking [centroid–centroid distance = 3.8254 (6) Å] and C—H⋯π inter­actions. PMID:21581375

Crystal structures of five new substituted tetrahydro-1-benzazepines with potential antiparasitic activity.

PubMed

Macías, Mario A; Acosta, Lina M; Sanabria, Carlos M; Palma, Alirio; Roussel, Pascal; Gauthier, Gilles H; Suescun, Leopoldo

2016-05-01

Tetrahydro-1-benzazepines have been described as potential antiparasitic drugs for the treatment of chagas disease and leishmaniasis, two of the most important so-called `forgotten tropical diseases' affecting South and Central America, caused by Trypanosoma cruzi and Leishmania chagasi parasites, respectively. Continuing our extensive work describing the structural characteristics of some related compounds with interesting biological properties, the crystallographic features of three epoxy-1-benzazepines, namely (2SR,4RS)-6,8-dimethyl-2-(naphthalen-1-yl)-2,3,4,5-tetrahydro-1H-1,4-epoxy-1-benzazepine, (1), (2SR,4RS)-6,9-dimethyl-2-(naphthalen-1-yl)-2,3,4,5-tetrahydro-1H-1,4-epoxy-1-benzazepine, (2), and (2SR,4RS)-8,9-dimethyl-2-(naphthalen-1-yl)-2,3,4,5-tetrahydro-1H-1,4-epoxy-1-benzazepine, (3), all C22H21NO, and two 1-benzazepin-4-ols, namely 7-fluoro-cis-2-[(E)-styryl]-2,3,4,5-tetrahydro-1H-1-benzazepin-4-ol, C18H18FNO, (4), and 7-fluoro-cis-2-[(E)-pent-1-enyl]-2,3,4,5-tetrahydro-1H-1-benzazepin-4-ol, C15H20FNO, (5), are described. Some peculiarities in the crystallization behaviour were found, involving significant variations in the crystalline structures as a result of modest changes in the peripheral substituents in (1)-(3) and the occurrence of discrete disorder due to the molecular overlay of enantiomers with more than one conformation in (5). In particular, an interesting phase change on cooling was observed for compound (5), accompanied by an approximate fourfold increase of the unit-cell volume and a change of the Z' value from 1 to 4. This transition is a consequence of the partial ordering of the pentenyl chains in half of the molecules breaking half of the -3 symmetry axes observed in the room-temperature structure of (5). The structural assembly in all the title compounds is characterized by not only (N,O)-H...(O,N) hydrogen bonds, but also by unconventional C-H...O contacts, resulting in a wide diversity of packing.

Chemical Reactions in Supercritical Carbon Dioxide

NASA Astrophysics Data System (ADS)

Wai, Chien M.; Hunt, Fred; Ji, Min; Chen, Xiaoyuan

1998-12-01

Utilizing supercritical fluids as environmentally benign solvents for chemical synthesis is one of the new approaches in the "greening" of chemistry. Carbon dioxide is the most widely used gas for supercritical fluid studies because of its moderate critical constants, nontoxic nature, and availability in pure form. One unique property of supercritical carbon dioxide (sc-CO2) is its high solubility for fluorinated compounds. Thus sc-CO2 can be used to replace Freons that are conventionally used as solvents for synthesis of perfluoro-polymers. Another property of sc-CO2 is its miscibility with gases such as H2. Heterogeneous reactions involving these gases may become homogeneous reactions in sc-CO2. Reactions in sc-CO2 may offer several advantages including controlling phase behavior and products, increasing speed of reactions, and obtaining specific reaction channels. This paper describes the following nine types of chemical reactions reported in the literature utilizing sc-CO2 as a solvent to illustrate the unique properties of the supercritical fluid reaction systems: (i) hydrogenation and hydroformylation, (ii) synthesis of organometallic compounds, (iii) metal chelation and extraction, (iv) preparation of inorganic nanoparticles, (v) stereo-selectivity of lipase-catalyzed reactions, (vi) asymmetric catalytic hydrogenation, (vii) polymerization, (viii) Diels-Alder reaction, and (ix) free radical reactions.

A validated HPLC method for the determination of pyridostigmine bromide, acetaminophen, acetylsalicylic acid and caffeine in rat plasma and urine.

PubMed

Abu-Qare, A W; Abou-Donia, M B

2001-12-01

A method was developed for the separation and quantification of the anti-nerve agent pyridostigmine bromide (PB; 3-dimethylaminocarbonyloxy-N-methyl pyridinium bromide), the analgesic drugs acetaminophen and acetylsalicylic acid, and the stimulant caffeine (3,7-dihydro-1,3,7-trimethyl-1-H-purine-2,6-dione) in rat plasma and urine. The compounds were extracted using C(18) Sep-Pak(R) cartridges then analyzed by high performance liquid chromatography (HPLC) with reversed phase C18 column, and UV detection at 280 nm. The compounds were separated using gradient of 1-85% acetonitrile in water (pH 3.0) at a flow rate ranging between 1 and 1.5 ml/min in a period of 14 min. The retention times ranged from 8.8 to 11.5 min. The limits of detection were ranged between 100 and 200 ng/ml, while limits of quantitation were 150-200 ng/ml. Average percentage recovery of five spiked plasma samples were 70.9+/-9.5, 73.7+/-9.8, 88.6+/-9.3, 83.9+/-7.8, and from urine 69.1+/-8.5, 74.5+/-8.7, 85.9+/-9.8, 83.2+/-9.3, for pyridostigmine bromide, acetaminophen, acetylsalicylic acid and caffeine, respectively. The relationship between peak areas and concentration was linear over range between 100 and 1000 ng/ml. The resulting chromatograms showed no interfering peaks from endogenous plasma or urine components. This method was applied to analyze these compounds following oral administration in rats.

Inhibition of in vitro leukotriene B4 biosynthesis in human neutrophil granulocytes and docking studies of natural quinones.

PubMed

Landa, Premysl; Kutil, Zsofia; Temml, Veronika; Malik, Jan; Kokoska, Ladislav; Widowitz, Ute; Pribylova, Marie; Dvorakova, Marcela; Marsik, Petr; Schuster, Daniela; Bauer, Rudolf; Vanek, Tomas

2013-01-01

Quinones are compounds frequently contained in medicinal plants used for the treatment of inflammatory diseases. Therefore, the impact of plant-derived quinones on the arachidonic acid metabolic pathway is worthy of investigation. In this study, twenty-three quinone compounds of plant origin were tested in vitro for their potential to inhibit leukotriene B4 (LTB4) biosynthesis in activated human neutrophil granulocytes with 5-lipoxygenase (5-LOX) activity. The benzoquinones primin (3) and thymohydroquinone (4) (IC50 = 4.0 and 4.1 microM, respectively) showed activity comparable with the reference inhibitor zileuton (1C50 = 4.1 microM). Moderate activity was observed for the benzoquinone thymoquinone (2) (1C50 = 18.2 microM) and the naphthoquinone shikonin (1) (IC50 = 24.3 microM). The anthraquinone emodin and the naphthoquinone plumbagin (5) displayed only weak activities (IC50 > 50 microM). The binding modes of the active compounds were further evaluated in silico by molecular docking to the human 5-LOX crystal structure. This process supports the biological data and suggested that, although the redox potential is responsible for the quinone's activity on multiple targets, in the case of 5-LOX the molecular structure plays a vital role in the inhibition. The obtained results suggest primin as a promising compound for the development of dual COX-2/5-LOX inhibitors.

Spectroscopic characterization, antimicrobial activity and molecular docking study of novel azo-imine functionalized sulphamethoxazoles

NASA Astrophysics Data System (ADS)

Sahu, Nilima; Mondal, Sudipa; Naskar, Kaushik; Mahapatra, Ananya Das; Gupta, Suvroma; Slawin, Alexandra M. Z.; Chattopadhyay, Debprasad; Sinha, Chittaranjan

2018-03-01

[SMXsbnd Ndbnd Nsbnd C6H3sbnd (p-OH)(msbnd CHO)] (1) reacts with ArNH2 to synthesize Schiff bases, [SMXsbnd Ndbnd Nsbnd C6H3sbnd (psbnd OH)(msbnd HCdbnd Nsbnd Ar)] (Ar = sbnd C6H5 (2a), sbnd C6H4sbnd psbnd CH3 (2b), sbnd C6H4sbnd psbnd OCH3 (2c), sbnd C6H4sbnd psbnd Cl (2d), sbnd C6H4sbnd psbnd NO2 (2e), sbnd C10H7 (2f)) and the products have been assessed for antibacterial properties against Gram positive bacteria, B. subtillis: IC50 (μg/ml): 39.2 (1), 60.1 (2a), 64.0 (2b), 85.6 (2c), 55.1 (2d), 88.4 (2e) and 65.1 (2f); and Gram negative bacteria, E. coli: IC50 (μg/ml): 159.0 (1), 151.4 (2a), 155.3 (2b), 140 (2c), 156.0 (2d), 153.5 (2e) and 157 (2f). The cell line toxicity (Vero cells) has also been evaluated with these compounds and EC50 (μg/ml) values are 129.9 (1), 74.2 (2a) and 93.0 (2b), 191.9 (2c), 99.1 (2d), 93.2 (2e) and 62.0 (2f). The anti-viral efficiency against harpies virus (HSVsbnd 1F ATCC-733) infection demonstrates that the compound 1 has highest selectivity index (CC50/EC50), 5.06 than the compounds 2a-f (CC50/EC50: 1.18 (2a), 1.42 (2b), 3.50 (2c), 1.45 (2d), 1.58 (2e), 1.29 (2f)). The compounds have been spectroscopically characterized and the structural confirmation has been established in one case by single crystal X-ray diffraction studies of 2c. In silico Molecular Docking study has been done using optimized geometries of the compounds to search the most favored binding mode of these drugs and hence useful to explain their competitive drug efficiency.

A highly selective dispersive liquid-liquid microextraction approach based on the unique fluorous affinity for the extraction and detection of per- and polyfluoroalkyl substances coupled with high performance liquid chromatography tandem-mass spectrometry.

PubMed

Wang, Juan; Shi, Yali; Cai, Yaqi

2018-04-06

In the present study, a highly selective fluorous affinity-based dispersive liquid-liquid microextraction (DLLME) technique was developed for the extraction and analysis of per- and polyfluoroalkyl substances (PFASs) followed by high performance liquid chromatography tandem-mass spectrometry. Perfluoro-tert-butanol with multiple C-F bonds was chosen as the extraction solvent, which was injected into the aqueous samples with a dispersive solvent (acetonitrile) in a 120:800 (μL, v/v) mixture for PFASs enrichment. The fluorous affinity-based extraction mechanism was confirmed by the significantly higher extraction recoveries for PFASs containing multiple fluorine atoms than those for compounds with fewer or no fluorine atoms. The extraction recoveries of medium and long-chain PFASs (CF 2  > 5) exceeded 70%, except perfluoroheptanoic acid, while those of short-chain PFASs were lower than 50%, implying that the proposed DLLME may not be suitable for their extraction due to weak fluorous affinity. This highly fluoroselective DLLME technique can greatly decrease the matrix effect that occurs in mass spectrometry detection when applied to the analysis of urine samples. Under the optimum conditions, the relative recoveries of PFASs with CF 2  > 5 ranged from 80.6-121.4% for tap water, river water and urine samples spiked with concentrations of 10, 50 and 100 ng/L. The method limits of quantification for PFASs in water and urine samples were in the range of 0.6-8.7 ng/L. Furthermore, comparable concentrations of PFASs were obtained via DLLME and solid-phase extraction, confirming that the developed DLLME technique is a promising method for the extraction of PFASs in real samples. Copyright © 2018 Elsevier B.V. All rights reserved.

Economy of Catalyst Synthesis-Convenient Access to Libraries of Di- and Tetranaphtho Azepinium Compounds.

PubMed

Tharamak, Sorachat; Knittl-Frank, Christian; Manaprasertsak, Auraya; Pengsook, Anchulee; Suchy, Lydia; Schuller, Philipp; Happl, Barbara; Roller, Alexander; Widhalm, Michael

2018-03-24

Efficient optimization procedures in chiral catalysis are usually linked to a straightforward strategy to access groups of structurally similar catalysts required for fine-tuning. The ease of building up such ligand libraries can be increased when the structure-modifying step (introduction of a substituent) is done at a later stage of the synthesis. This is demonstrated for the extended family of di- and tetranaphtho azepinium compounds, widely used as chiral phase transfer catalysts (PTC). Using 2,6-diiodo-4,5-dihydro-3 H -dinaphtho[2,1-c:1',2'-e]azepine and 4,8-diiodo-6,7-dihydro-5 H -dibenzo[c,e]azepine, respectively, as key intermediates, 18 spiro -azepinium compounds were synthesized in a total yield of 25-42% over 6-7 steps from 1,1'-binaphthyl-2,2'-dicarboxylic acid or diphenic acid, respectively. The replacement of iodo groups with aryl substituents was performed as the last or the penultimate step of the synthesis.

Determination of MDMA, MDA, MDEA and MBDB in oral fluid using high performance liquid chromatography with native fluorescence detection.

PubMed

Concheiro, Marta; de Castro, Ana; Quintela, Oscar; López-Rivadulla, Manuel; Cruz, Angelines

2005-06-10

This paper describes the analytical methodology for the determination of MDMA, MDA, MDEA and MBDB in oral fluid. After a liquid-liquid extraction, the analysis was carried out by high performance liquid chromatography (HPLC), with fluorescence detection. The detector wavelength was fixed at 285 nm for excitation and 320 nm for emission. The mobile phase, a mixture of phosphate buffer (pH=5) and acetonitrile (75:25), and the column, Kromasil 100 C8 5 microm 250 mm x 4.6mm, allowed good separation of the compounds in an isocratic mode in only 10 min. The method was validated and showed good limits of detection (2 ng/mL) and quantitation (10 ng/mL) for all the amphetamine derivatives. No interfering substances were detected. A stability study of these compounds in oral fluid stored at three different temperatures (-18, 4 and 20 degrees C) over 10 weeks was conducted, showing a time-dependent degradation of the four compounds.

Room temperature rechargeable magnesium batteries with sulfur-containing composite cathodes prepared from elemental sulfur and bis(alkenyl) compound having a cyclic or linear ether unit

NASA Astrophysics Data System (ADS)

Itaoka, Kanae; Kim, In-Tae; Yamabuki, Kazuhiro; Yoshimoto, Nobuko; Tsutsumi, Hiromori

2015-11-01

Room temperature rechargeable magnesium (Mg) batteries are constructed from Mg as a negative material, sulfur (S)-containing composite prepared from elemental sulfur and the bis(alkenyl) compound having a crown ether unit (BUMB18C6) or linear ether unit (UOEE) as a positive material and the simple electrolyte (0.7 mol dm-3 Mg[N(SO2CF3)2]2-triglyme (G3) solution). The reaction between molten S and the bis(alkenyl) compound (BUMB18C6 or UOEE) provides the sulfur-containing composite, S-BUMB18C6 or S-UOEE. Both of the sulfur-containing composites are electrochemically active in the Mg salt-based electrolyte, acetonitrile- or G3- Mg[N(SO2CF3)2]2 electrolyte. The first discharge capacity of the test cells with the sulfur-containing composite is 460 Ah kg-1 (per the weight of sulfur in the composite) with the S-BUMB18C6 electrode and 495 Ah kg-1 with the S-UOEE electrode. According to the continuous charge-discharge cycle tests (at 10th cycle), the discharge capacity of the test cell with the S-BUMB18C6 electrode (68.1 Ah kg-1) is higher than that with the S-UOEE electrode (0.18 Ah kg-1). The crown ether units in the S-BUMB18C6 composite may create ion-conducting paths in the cathode, prevent rise in the internal resistance of the cathode, and provide better cycle performance of the test cells with the S-BUMB18C6 composite electrode than that with the S-UOEE electrode.

Crystal structures of complexes of the cys-syn-cys isomer of dicyclohexano-18-crown-6 with oxonium hexafluorotantalate and oxonium hexafluoroniobate

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

Fonari, M. S.; Alekseeva, O. A.; Furmanova, N. G.

2007-03-15

The crystal structures of [(cys-syn-cys-dicyclohexano-18-crown-6 . H{sub 3}O)][TaF{sub 6}] and [(cys-syn-cys-dicyclohexano-18-crown-6 . H{sub 3}O)][NbF{sub 6}] complex compounds are determined using X-ray diffraction analysis. The tantalum complex has two polymorphic modifications, namely, the monoclinic (I) and triclinic (II) modifications. The unit cell parameters of these compounds are as follows: a = 8.507(4) A, b = 11.947(5) A, c = 27.392(12) A, {beta} = 93.11(1) deg., Z = 4, and space group P2{sub 1}/n for modification I; and a = 10.828(1) A, b = 11.204(1) A, c = 12.378(1) A, {alpha} = 72.12(1) deg., {beta} = 79.40(1) deg., {gamma} = 73.70(1) deg.,more » Z = 2, and space group P-1 for modification II. The triclinic niobium complex [(cys-syn-cys-dicyclohexano-18-crown-6 . H{sub 3}O)][NbF{sub 6}] (III) with the unit cell parameters a = 10.796(3) A, b = 11.183(3) A, c = 12.352(3) A, {alpha} = 72.364(5) deg., {beta} = 79.577(5) deg., {gamma} = 73.773(4) deg., Z = 2, and space group P-1 is isostructural with tantalum complex II. The structures of all three complexes are ionic in character. The oxonium cation in complexes I-III is encapsulated by the crown ether and thus forms one ordinary and two bifurcated hydrogen bonds with the oxygen atoms of the crown ether. This macrocyclic cation is bound to the anions through the C-H...F contacts (H...F, 2.48-2.58 A). The conformation of the macrocycle in complex I differs substantially from that in complex II (III)« less

Sex-related difference in the inductions by perfluoro-octanoic acid of peroxisomal beta-oxidation, microsomal 1-acylglycerophosphocholine acyltransferase and cytosolic long-chain acyl-CoA hydrolase in rat liver.

PubMed Central

Kawashima, Y; Uy-Yu, N; Kozuka, H

1989-01-01

Inductions by perfluoro-octanoic acid (PFOA) of hepatomegaly, peroxisomal beta-oxidation, microsomal 1-acylglycerophosphocholine acyltransferase and cytosolic long-chain acyl-CoA hydrolase were compared in liver between male and female rats. Marked inductions of these four parameters were seen concurrently in liver of male rats, whereas the inductions in liver of female rats were far less pronounced. The sex-related difference in the response of rat liver to PFOA was much more marked than that seen with p-chlorophenoxyisobutyric acid (clofibric acid) or 2,2'-(decamethylenedithio)diethanol (tiadenol). Hormonal manipulations revealed that this sex-related difference in the inductions is strongly dependent on sex hormones, namely that testosterone is necessary for the inductions, whereas oestradiol prevented the inductions by PFOA. PMID:2570571

Viscosity effects on the thermal decomposition of bis(perfluoro-2-N-propoxypropionyl) peroxide in dense carbon dioxide and fluorinated solvents.

PubMed

Bunyard, W C; Kadla, J F; DeYoung, J; DeSimone, J M

2001-08-01

The thermal decomposition of the free-radical initiator bis(perfluoro-2-N-propoxyprionyl) peroxide (BPPP) was studied in dense carbon dioxide and a series of fluorinated solvents. For the fluorinated solvents, the observed first-order decomposition rate constants, k(obs), increased with decreasing solvent viscosity, suggesting a single-bond decomposition mechanism. The k(obs) values are comparatively larger in dense carbon dioxide and similar to the "zero-viscosity" rate constants extrapolated from the decomposition kinetics in the fluorinated solvents. The decomposition activation parameters demonstrate a compensation behavior of the activation enthalpy with the activation entropy upon change in solvent viscosity. Comparison of the change in activation parameter values upon change in solvent viscosity for BPPP with two additional initiators, acetyl peroxide (AP) and trifluoroacetyl peroxide (TFAP), further suggests that carbon dioxide exerts a very minimal influence on the decomposition mechanism of these initiators through solvent-cage effects.

[Studies on chemical constituents from roots of Mirabilis jalapa].

PubMed

Lai, Guo-Fang; Luo, Shi-De; Cao, Jian-Xin; Wang, Yi-Fen

2008-01-01

To investigate the anti-HIV constituents from the root of Mirabilis jalapa. The compounds were isolated by column chromatography on silica gel, Sephadex LH - 20, MCI-gel CHP-20P and RP-18. The structure were identified by means of NMR and MS analyses (1H-NMR, 13C-NMR, MS). Eleven compounds were isolated and identified as astragaloside II (1), astragaloside II (2), astragaloside IV (3), astragaloside VI (4), flazin (5), 4'-hydroxy-2, 3-dihydroflavone 7-beta-D-glucopyranoside (6), gingerglycolipid A (7), 3, 4-dihydroxybenzaldehyd (8), p-hydroxybenzaldehyde (9), beta-sitosterol (10) and daucosterol (11). Compounds 1-9 were obtained from this genus for the first time.

Degradation and environmental risk of surfactants after the application of compost sludge to the soil

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

Gonzalez, M.M.; Martin, J.; Camacho-Munoz, D.

2012-07-15

Highlights: Black-Right-Pointing-Pointer Degradation of surfactants in soil amended with sewage sludge during 100 days. Black-Right-Pointing-Pointer Temperature influences on the degradation of the studied compounds. Black-Right-Pointing-Pointer Overall, the LAS degradation is faster than the NP compounds degradation. Black-Right-Pointing-Pointer Therefore, the LAS presented lower environmental risk than the NP compounds. - Abstract: In this work, the degradation of anionic and non-ionic surfactants in agricultural soil amended with sewage sludge is reported. The compounds analysed were: linear alkylbenzene sulphonates (LAS) with a 10-13 carbon alkylic chain, and nonylphenolic compounds (NPE), including nonylphenol (NP) and nonylphenol ethoxylates with one and two ethoxy groups (NP1EOmore » and NP2EO). The degradation studies were carried out under winter (12.7 Degree-Sign C) and summer (22.4 Degree-Sign C) conditions in Andalusia region. The concentration of LAS was reduced to 2% of the initial concentration 100 day after sludge-application to the soil. The half-life time measured for LAS homologues were ranged between 4 and 14 days at 12.7 Degree-Sign C and between 4 and 7 days at 22.4 Degree-Sign C. With regard to NPE compounds, after 8 and 4 days from the beginning of the experiment at 12.7 and 22.4 Degree-Sign C, respectively, their concentration levels were increased to 6.5 and 13.5 mg/kg dm (dry matter) as consequence of the degradation of nonylphenol polyethoxylates. These concentration levels were reduced to 5% after 63 and 70 days for 12.7 Degree-Sign C and 22.4 Degree-Sign C, respectively. The half-life times measured for NPEs were from 8 to 16 days at 12.7 Degree-Sign C and from 8 to 18 days at 22.4 Degree-Sign C. Environmental risk assessment revealed that for LAS homologues no environment risk could be expected after 7 and 8 days of sludge application to the soil for 22.4 and 12.7 Degree-Sign C, respectively; however, potential toxic effects could be observed for the nonylphenolic compounds during the first 56 days after sludge application to the soil.« less

Emerging investigator series: a 14-year depositional ice record of perfluoroalkyl substances in the High Arctic.

PubMed

MacInnis, John J; French, Katherine; Muir, Derek C G; Spencer, Christine; Criscitiello, Alison; De Silva, Amila O; Young, Cora J

2017-01-25

To improve understanding of long-range transport of perfluoroalkyl substances to the High Arctic, samples were collected from a snow pit on the Devon Ice Cap in spring 2008. Snow was analyzed for perfluoroalkyl acids (PFAAs), including perfluoroalkyl carboxylic acids (PFCAs) and perfluoroalkyl sulfonic acids (PFSAs), as well as perfluorooctane sulfonamide (FOSA). PFAAs were detected in all samples dated from 1993 to 2007. PFAA fluxes ranged from <1 to hundreds of ng per m 2 per year. Flux ratios of even-odd PFCA homologues were mostly between 0.5 and 2, corresponding to molar ratios expected from atmospheric oxidation of fluorotelomer compounds. Concentrations of perfluorobutanoic acid (PFBA) were much higher than other PFCAs, suggesting PFBA loading on the Devon Ice Cap is influenced by additional sources, such as the oxidation of heat transfer fluids. All PFCA fluxes increased with time, while PFSA fluxes generally decreased with time. No correlations were observed between PFAAs and the marine aerosol tracer, sodium. Perfluoro-4-ethylcyclohexanesulfonate (PFECHS) was detected for the first time in an atmospherically - derived sample, and its presence may be attributed to aircraft hydraulic system leakage. Observations of PFAAs from these samples provide further evidence that atmospheric oxidation of volatile precursors is an important source of PFAAs to the Arctic environment.

Purine-benzimidazole hybrids: synthesis, single crystal determination and in vitro evaluation of antitumor activities.

PubMed

Sharma, Alka; Luxami, Vijay; Paul, Kamaldeep

2015-03-26

In an effort to identify novel compounds for the treatment of cancer, a diverse array of potential bioactive hybrid, purine-benzimidazole was synthesized in good yields through nucleophilic substitution at C6 position of purine ring with versatile cyclic amines at C2 position. The structures of newly prepared compounds were confirmed by IR, (1)H, (13)C NMR, mass spectroscopy and, in case of 19, by single crystal X-ray diffraction analysis. The newly synthesized compounds were evaluated against 60 human tumour cell lines at one dose concentration level. Compound 6 exhibited significant growth inhibition and was evaluated as 60 cell panel at five dose concentration levels. Compound 6 proved to be 1.25 fold more active than the positive control 5-FU, with GI50 value of 18.12 μM (MG-MID). Interaction of the compounds with Aurora-A enzyme involved in the process of propagation of cancer, has also been investigated. Compound 6 showed selectivity towards Aurora-A kinase inhibition with IC50 value of 0.0l μM. Molecular docking studies in the active binding site provided theoretical support for the experimental biological data acquired. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

Comparison of [11C]TZ1964B and [18F]MNI659 for PET imaging brain PDE10A in nonhuman primates.

PubMed

Liu, Hui; Jin, Hongjun; Yue, Xuyi; Han, Junbin; Yang, Hao; Flores, Hubert; Su, Yi; Alagille, David; Perlmutter, Joel S; Tamagnan, Gilles; Tu, Zhude

2016-10-01

Phosphodiesterase 10A (PDE10A) inhibitors show therapeutic effects for diseases with striatal pathology. PET radiotracers have been developed to quantify in vivo PDE10A levels and target engagement for therapeutic interventions. The aim of this study was to compare two potent and selective PDE10A radiotracers, [ 11 C]TZ1964B and [ 18 F]MNI659 in the nonhuman primate (NHP) brain. Double scans in the same cynomolgus monkey on the same day were performed after injection of [ 11 C]TZ1964B and [ 18 F]MNI659. Specific uptake was determined in two ways: nondisplaceable binding potential (BP ND ) was calculated using cerebellum as the reference region and the PDE-10A enriched striatum as the target region of interest (ROI); the area under the time-activity curve (AUC) for the striatum to cerebellum ratio was also calculated. High-performance liquid chromatography (HPLC) analysis of solvent-extracted NHP plasma identified the percentage of intact tracer versus radiolabeled metabolites samples post injection of each radiotracer. Both radiotracers showed high specific accumulation in NHP striatum. [ 11 C]TZ1964B has higher striatal retention and lower specific striatal uptake than [ 18 F]MNI659. The BP ND estimates of [ 11 C]TZ1964B were 3.72 by Logan Reference model (LoganREF) and 4.39 by simplified reference tissue model (SRTM); the BP ND estimates for [ 18 F]MNI659 were 5.08 (LoganREF) and 5.33 (SRTM). AUC ratios were 5.87 for [ 11 C]TZ1964B and 7.60 for [ 18 F]MNI659. Based on BP ND values in NHP striatum, coefficients of variation were ~10% for [ 11 C]TZ1964B and ~30% for [ 18 F]MNI659. Moreover, the metabolism study showed the percentage of parent compounds were ~70% for [ 11 C]TZ1964B and ~50% for [ 18 F]MNI659 60 min post injection. These data indicate that either [ 11 C]TZ1964B or [ 18 F]MNI659 could serve as suitable PDE10A PET radiotracers with distinguishing features for particular clinical application.

An X-ray crystallographic and density functional theory study of (3Z)-4-(5-ethylsulfonyl-2-hydroxyanilino)pent-3-en-2-one and (3Z)-4-(5-tert-butyl-2-hydroxyanilino)pent-3-en-2-one.

PubMed

Akerman, Kate J; Munro, Orde Q

2013-03-01

The Schiff base enaminones (3Z)-4-(5-ethylsulfonyl-2-hydroxyanilino)pent-3-en-2-one, C13H17NO4S, (I), and (3Z)-4-(5-tert-butyl-2-hydroxyanilino)pent-3-en-2-one, C15H21NO2, (II), were studied by X-ray crystallography and density functional theory (DFT). Although the keto tautomer of these compounds is dominant, the O=C-C=C-N bond lengths are consistent with some electron delocalization and partial enol character. Both (I) and (II) are nonplanar, with the amino-phenol group canted relative to the rest of the molecule; the twist about the N(enamine)-C(aryl) bond leads to dihedral angles of 40.5 (2) and -116.7 (1)° for (I) and (II), respectively. Compound (I) has a bifurcated intramolecular hydrogen bond between the N-H group and the flanking carbonyl and hydroxy O atoms, as well as an intermolecular hydrogen bond, leading to an infinite one-dimensional hydrogen-bonded chain. Compound (II) has one intramolecular hydrogen bond and one intermolecular C=O...H-O hydrogen bond, and consequently also forms a one-dimensional hydrogen-bonded chain. The DFT-calculated structures [in vacuo, B3LYP/6-311G(d,p) level] for the keto tautomers compare favourably with the X-ray crystal structures of (I) and (II), confirming the dominance of the keto tautomer. The simulations indicate that the keto tautomers are 20.55 and 18.86 kJ mol(-1) lower in energy than the enol tautomers for (I) and (II), respectively.

Bioactive compounds from Peperomia pellucida.

PubMed

Xu, Su; Li, Na; Ning, Meng-Meng; Zhou, Cai-Hong; Yang, Qiao-Rong; Wang, Ming-Wei

2006-02-01

Five new compounds (1-5), including two secolignans, two tetrahydrofuran lignans, and one highly methoxylated dihydronaphthalenone, were isolated from the whole plant of Peperomia pellucida. These compounds were accompanied by the known peperomins A, B, C, and E, 7,8-trans-8,8'-trans-7',8'-cis-7,7'-bis(5-methoxy-3,4-methylenedioxyphenyl)-8-acetoxymethyl-8'-hydroxymethyltetrahydrofuran, 7,8-trans-8,8'-trans-7',8'-cis-7-(5-methoxy-3,4-methylenedioxyphenyl)-7'-(4-hydroxy-3,5-dimethoxyphenyl)-8,8'-diacetoxymethyltetrahydrofuran, sesamin, and isoswertisin. New structures were elucidated mainly by NMR and MS techniques, and anticancer activities evaluated in HL-60, MCF-7, and HeLa cell lines. Compound 1 and peperomin E show growth inhibitory effects on the three cancer cell lines with IC(50) values ranging between 1.4 and 9.1 and between 1.8 and 11.1 microM, respectively. Compound 2 has a weak suppressive activity on HL-60 cells (IC(50) = 10.8 microM), while 7,8-trans-8,8'-trans-7',8'-cis-7,7'-bis(5-methoxy-3,4-methylenedioxyphenyl)-8-acetoxymethyl-8'-hydroxymethyltetrahydrofuran exhibits estrogen-like properties (EC(50) = 3.1 microM) in CV-1 cells transfected with human estrogen receptor (ERalpha).

Development of Novel Drugs That Target Coactivation Sites of the Androgen Receptor for Treatment of Antiandrogen-Resistant Prostate Cancer

DTIC Science & Technology

2014-10-01

2009;324:787-90. 4. Clegg NJ, Wongvipat J , Joseph JD, Tran C , Ouk S, Dilhas A, et al. ARN-509: A Novel Antiandrogen for Prostate Cancer Treatment. Cancer...ABSTRACT 18. NUMBER OF PAGES 19a. NAME OF RESPONSIBLE PERSON USAMRMC USAMRMC a. REPORT U b. ABSTRACT U c . THIS PAGE...performed on all our compounds that are under 1 µM in eGFP activity. % A c tiv a tio n -3 -2 -1 1 -5 0 5 0 1 0 0 M D V 3 1 0 0 1 3 6 8 8 P S A

New supramolecular cocrystal of 2-amino-5-chloropyridine with 3-methylbenzoic acids: Syntheses, structural characterization, Hirshfeld surfaces and quantum chemical investigations

NASA Astrophysics Data System (ADS)

Thanigaimani, Kaliyaperumal; Khalib, Nuridayanti Che; Temel, Ersin; Arshad, Suhana; Razak, Ibrahim Abdul

2015-11-01

2-amino-5-chloropyridine: 3-methylbenzoic acid [(2A5CP) (3MBA)] (I) cocrystal was synthesized and its single crystal was grown by slow evaporation technique. The structure of the grown crystal was elucidated by using single crystal X-ray diffraction technique. The cocrystal belongs to the monoclinic crystallographic system with space group P21/c, Z = 4, and a = 13.3155 (5) Å, b = 5.5980 (2) Å, c = 18.3787 (7) Å, β = 110.045 (2)°. The crystal structure is stabilized by Npyridine-H•••Odbnd C, Cdbnd O-H•••Npyridine and C-H⋯O type hydrogen bonding interactions. The presence of unionized -COOH functional group in the cocrystal was identified both by spectral methods and X-ray structural analysis. The experimental studies obtained by using the methods of single crystal X-ray analysis, powder X-ray diffraction (PXRD) analysis, FTIR, 1H NMR and 13C NMR spectroscopies confirmed the predicted cocrystal. The supramolecular assembly of the cocrystal was analyzed and discussed. The molecular geometry, vibrational frequencies of the compound in the ground state were calculated by using the density functional theory (DFT) method with 6-311++G (d,p) basis set and were compared with the experimental data. Additionally, HOMO-LUMO energy gap, natural bond orbital (NBO) analysis and nonlinear optical (NLO) properties of the compound were performed at B3LYP/6-311++G (d,p) level. Hirshfeld surfaces were used to confirm the existence of inter-molecular interactions in the compound.

Preparative separation of the polar part from the rhizomes of Anemarrhena asphodeloides using a hydrophilic C18 stationary phase.

PubMed

Cai, Jianfeng; Xin, Huaxia; Cheng, Lingping; Fu, YanHui; Jiang, Dasen; Feng, Jiatao; Fu, Qing; Jin, Yu; Liang, Xinmiao

2017-09-15

The goal of this study was to develop a method that utilized a hydrophilic C18 stationary phase in the preparative high performance liquid chromatography to isolate the polar part from the rhizomes of Anemarrhena asphodeloides. The results showed that an initial mobile phase of pure water for the separation could greatly increase the retention and solubility of the polar compounds at the preparative scale. Introducing polar groups on the surface of the hydrophilic C18 column together with the use of optimized mobile phase compositions improved the column separation selectivity for polar compounds. Eleven previously undescribed compounds in Anemarrhena asphodeloides were obtained, indicating that the method developed in this study would facilitate the purification and separation of the polar part of traditional Chinese medicines. Copyright © 2017 Elsevier B.V. All rights reserved.

Polyphenylenesulfide, noxon® an ozone scavenger for the analysis of oxygenated terpenes in air

NASA Astrophysics Data System (ADS)

Calogirou, A.; Duane, M.; Kotzias, D.; Lahaniati, M.; Larsen, B. R.

During sampling, oxygenated terpenes may undergo decomposition through reaction with atmospheric ozone. We have studied their ozonolytic decomposition during preconcentration on Tenax. The saturated. terpenoids 1,8-cineole, bornyl acetate nopinone and pinonaldehyde are practically unaffected by ozone in the range of 8 to 120 ppbv. Compounds which contain one or more C-C double bonds are decomposed in the order: linalool ≈ citronellal ≈ 6-methyl-5-hepten-2-one > citral > 4-acetyl-1-methyl-cyclohexane > 3-(1-methylethenyl)-6-oxo-heptanal > myrtenal ≈ 2-methyl-3-buten-2-ol. The degree of decomposition varies from 0 to 5% for the least reactive to 80 to 90% for the most reactive compounds. A broad range of material was investigated as potential ozone scavengers. By using the polymer noXon (polyphenylenesulfide) all the investigated compounds could be sampled with quantitative recoveries even at high ozone mixing ratios (95-110 ppbv). This ozone scrubber was tested for sampling of terpene oxidation products on Tenax and dinitrophenylhydrazine impregnated C 18-silicagel cartridges. Recoveries from 85 to 110% were obtained for all investigated compounds. The method was used for the analysis of oxidation products of terpenes in ambient air in three campaigns. Attention was focused on nopinone from β-pinene, pinonaldehyde from α-pinene, 3-(1-methylethenyl)-6-oxo-heptanal and 4-acetyl-1-methyl-cyclohexane from limonene, and 5-(1-methylethyl)-bicyclo[3.1.0] hexan-2-one from sabinene. Nopinone was the only product which could be frequently detected in ratios from 0 to 90% of the measured β-pinene concentrations. Pinonaldehyde was encountered only once (30% of α-pinene) while the other products were not found. These data have to be seen as a first attempt to measure terpene oxidation products in the troposphere.

Discovery of gigantic molecular nanostructures using a flow reaction array as a search engine.

PubMed

Zang, Hong-Ying; de la Oliva, Andreu Ruiz; Miras, Haralampos N; Long, De-Liang; McBurney, Roy T; Cronin, Leroy

2014-04-28

The discovery of gigantic molecular nanostructures like coordination and polyoxometalate clusters is extremely time-consuming since a vast combinatorial space needs to be searched, and even a systematic and exhaustive exploration of the available synthetic parameters relies on a great deal of serendipity. Here we present a synthetic methodology that combines a flow reaction array and algorithmic control to give a chemical 'real-space' search engine leading to the discovery and isolation of a range of new molecular nanoclusters based on [Mo(2)O(2)S(2)](2+)-based building blocks with either fourfold (C4) or fivefold (C5) symmetry templates and linkers. This engine leads us to isolate six new nanoscale cluster compounds: 1, {Mo(10)(C5)}; 2, {Mo(14)(C4)4(C5)2}; 3, {Mo(60)(C4)10}; 4, {Mo(48)(C4)6}; 5, {Mo(34)(C4)4}; 6, {Mo(18)(C4)9}; in only 200 automated experiments from a parameter space spanning ~5 million possible combinations.

Indole Alkaloids from Chaetomium globosum.

PubMed

Xu, Guo-Bo; He, Gu; Bai, Huan-Huan; Yang, Tao; Zhang, Guo-Lin; Wu, Lin-Wei; Li, Guo-You

2015-07-24

Two new indole alkaloids chaetocochin J (1) and chaetoglobinol A (8), along with chetomin (2), chetoseminudin A (3), cochliodinol (9), and semicochliodinol (10), were isolated from the rice culture of the fungus Chaetomium globosum. Their structures were elucidated by spectral analysis. Three new epipolythiodioxopiperazines, chaetocochins G-I (5-7), were identified by the combination of UPLC and mass spectrometric analysis. Chaetocochin I contained two sulfur bridges, one formed by three sulfur atoms between C-3 and C-11a, and the other formed by four sulfur atoms between C-3' and C-6'. Chaetocochin I was readily transformed into chetomin (2), chetoseminudin A (3), chaetocochin D (4), chaetocochin G (5), and chaetocochin H (6) by losing sulfur atoms. Compounds 1-3, and 8 exhibited antibacterial activities against Bacillus subtilis with MICs of 25, 0.78, 0.78, and 50 μg/mL, respectively, but not against Gram-negative bacterium (Escherichia coli). Compounds 2 and 8 were inactive against Candida albicans, Fusarium graminearum, Fusarium vasinfectum, Saccharomyces cerevisiae, and Aspergillus niger even at the high concentrations of 200 and 100 μg/mL, respectively. Compound 8 showed free radical scavenging capacity against the 1,1-diphenyl-2-picryl-hydrazyl (DPPH) and 2,2'-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid radical (ABTS(+•)), with IC50 values of 143.6 and 45.2 μM, respectively. The free radical scavenging capacity rates of compounds 1-3 on the DPPH and ABTS(+•) were less than 20% at the test concentrations (89.9-108.3 μM). The superoxide anion radical scavenging assay indicated that compounds 1-3, and 8 showed 14.8% (90.9 μM), 18.1% (90.9 μM), 51.5% (88.3 μM), and 30.4% (61.3 μM) superoxide anion radical scavenging capacity, respectively.

Hydrothermal treatment of chestnut shells (Castanea sativa) to produce oligosaccharides and antioxidant compounds.

PubMed

Gullón, Beatriz; Eibes, Gemma; Dávila, Izaskun; Moreira, María Teresa; Labidi, Jalel; Gullón, Patricia

2018-07-15

Hydrothermal treatment is an environmentally friendly technology that allows the solubilisation of hemicellulosic oligosaccharides with potential for their use as prebiotics. The purpose of this study was to solubilize oligosaccharides and antioxidant compounds from chestnut shells by a hydrothermal processing. The highest content of oligosaccharides (18.3 g/L), with a relatively low level of monosaccharides (2.4 g/L) and degradation products (0.5 g/L) was obtained at 180 °C (severity of 3.08). In addition, the liquors presented a high content of phenolic and flavonoid compounds with good antioxidant properties. The GC-MS revealed that the most abundant phenolic compound was pyrogallol (13.2%). The molecular weight distribution of the solubilization products showed that a 26.5% presented an apparent Mw of 6077 g/mol and a 73.5% presented an apparent Mw of 586 g/mol with a high polydispersity index. MALDI-TOF, FTIR, and TGA analyses revealed structural information of these compounds and their thermal stability. Copyright © 2018 Elsevier Ltd. All rights reserved.

Preparation of magnetic core mesoporous shell microspheres with C18-modified interior pore-walls for fast extraction and analysis of phthalates in water samples.

PubMed

Li, Zhongbo; Huang, Danni; Fu, Chinfai; Wei, Biwen; Yu, Wenjia; Deng, Chunhui; Zhang, Xiangmin

2011-09-16

In this study, core-shell magnetic mesoporous microspheres with C18-functionalized interior pore-walls were synthesized through coating Fe(3)O(4) microspheres with a mesoporous inorganic-organic hybrid layer with a n-octadecyltriethoxysilane (C18TES) and tetraethyl orthosilicate (TEOS) as the silica source and cetyltrimethylammonia bromide (CTAB) as a template. The obtained C18-functionalized Fe(3)O(4)@mSiO(2) microspheres possess numerous C18 groups anchored in the interior pore-walls, large surface area (274.7 m(2)/g, high magnetization (40.8 emu/g) and superparamagnetism, uniform mesopores (4.1 nm), which makes them ideal absorbents for simple, fast, and efficient extraction and enrichment of hydrophobic organic compounds in water samples. Several kinds of phthalates were used as the model hydrophobic organic compounds to systematically evaluate the performance of the C18-functionalized Fe(3)O(4)@mSiO(2) microspheres in extracting hydrophobic molecules by using a gas chromatography-mass spectrometry. Various parameters, including eluting solvent, the amounts of absorbents, extraction time and elution time were optimized. Hydrophobic extraction was performed in the interior pore of magnetic mesoporous microspheres, and the materials had the anti-interference ability to macromolecular proteins, which was also investigated in the work. Under the optimized conditions, C18-functionalized Fe(3)O(4)@mSiO(2) microspheres were successfully used to analyze the real water samples. The results indicated that this novel method was fast, convenient and efficient for the target compounds and could avoid being interfered by macromolecules. Copyright © 2011 Elsevier B.V. All rights reserved.

Nature and changes in organic matter in organic sediments. [organic matter in ocean sediments

NASA Technical Reports Server (NTRS)

Kaplan, I. R.

1973-01-01

A series of isoprenoid compounds were isolated from a heat treated marine sediment (from Tanner Basin) which were not present in the original sediment. Among the compounds identified were: phytol, dihydrophytol, C-18-isoprenoid ketone, phytanic and pristanic acids, C-19- and C-10-monoolefines, and the alkanes pristane and phytane. The significance and possible routes leading to these compounds is discussed.

Thermal alteration of organic matter in recent marine sediments. 2: Isoprenoids. [Tanner Basin off Southern California

NASA Technical Reports Server (NTRS)

Ikan, R.; Baedecker, M. J.; Kaplan, I. R.

1974-01-01

A series of isoprenoid compounds were isolated from a heat treated marine sediment (from Tanner Basin) which were not present in the original sediment. Among the compounds identified were: phytol, dihydrophytol, c-18-isoprenoid ketone, phytanic and pristanic acids, c-19 and c-20-monoolefines, and the alkanes pristane and phytane. The significance and possible routes leading to these compounds is discussed.

Environmental Impact Statement. Small Intercontinental Ballistic Missile Program. Malmstrom Air Force Base, Montana

DTIC Science & Technology

1987-12-01

Study for Sun River Electr’: Cooperative, Inc. Fairfield, Montana. Butler, G.C., C. Hyslop , and 0. Huntzinger (editors) 1980 Anthroposenic Compounds...Counties, Montana, 1980 -1984 3.1.3-2 Actual and Projected Population of Selected Montana ................ 3-7 Counties and Cities, the State of...by Grade Level 3.1.3-4 City of Great Falls Revenues and Expenditures, All Governmental .... 3-18 Governmental Funds, FY 1980 -2000 3.1.3-5 Cascade

Di-tert-butyl-bis(N-isopropyl-N-methyl-dithio-carbamato-κS,S')tin(IV).

PubMed

Muthalib, Amirah Faizah; Baba, Ibrahim; Samsudin, Mohd Wahid; Ng, Seik Weng

2010-03-03

The dithio-carbamate anions in the title compound, [Sn(C(4)H(9))(2)(C(5)H(10)NS(2))(2)], chelate to the Sn(IV) atom, which is six-coordinated in a skew-trapezoidal-bipyramidal geometry. The mol-ecule lies across a twofold rotation axis. The crystal studied was a non-merohedral twin, the ratio of the twin components being 0.82 (1):0.18 (1).

[Microbial transformation of glycyrrhetinic acid by Cunninghamella blakesleeana].

PubMed

Ma, Yuan; Xie, Dan; Wang, Zhao-hua; Dai, Jun-gui; An, Xi-qiang; Gu, Zheng-yi

2015-11-01

A study on the microbial transformation of glycyrrhetinic acid (GA) was conducted by a fungus, Cunninghamella blakesleeana CGMCC 3.970 systematically. After incubation with the cell cultures of C. blakesleeana CGMCC 3.970 at 25 degrees C for 7 days on a rotary shaker operating at 135 r x min(-1), GA was converted into one major product and five minor products. The products were extracted and purified by solvent extraction, macroporous adsorbent resin, silica gel column chromatography, and semi-preparative RP-HPLC chromatography. Their structures were identified as 3-oxo-15α-hydroxy-18β-glycyrrhetinic acid(1), 3-oxo-15β-hydroxy-18β-glycyrrhetinic acid (2), 7β,15α-dihydroxy-18β-glycyrrhetinic acid (3), 3-oxo-7β, 15α-dihydroxy-18β-glycyrrhetinic acid (4), 7β-hydroxy-18β-glycyrrhetinic acid(5) and 15α-hydroxy-18β-glycyrrhetinic acid(6) by the analyses of MS, 1H-NMR and 13C-NMR spectroscopic data respectively. Among them, 2 was a new compound. These results suggest that C. blakesleeana CGMCC 3.970 has the capability of selective ketonization and hydroxylation for GA. [Key words] glycyrrhetinic acid; Cunninghamella blakesleeana CGMCC 3. 970; microbial transformation

Mixed oxides of sodium, antimony (5+) and divalent metals (Ni, Co, Zn or Mg)

NASA Astrophysics Data System (ADS)

Politaev, V. V.; Nalbandyan, V. B.; Petrenko, A. A.; Shukaev, I. L.; Volotchaev, V. A.; Medvedev, B. S.

2010-03-01

A family of α-NaFeO 2-type oxides Na xM (1+x)/3Sb (2-x)/3O 2 ( M=Ni, Co, Zn, Mg; x≈0.8 or 0.9) has been prepared by solid state reactions and characterized by powder XRD. At x=1, ordering occurs with tripling the unit cells and formula units. The powder patterns for Na 3M2SbO 6 ( M=Ni, Co) comply with both trigonal P3 112 cell and monoclinic C2/ m cell. The Ni compound exhibits also a series of extremely weak reflections ( I<0.3%) that need doubling of the c axis, and the final cell is C2/ c, a=5.3048(3), b=9.1879(4), c=10.8356(7), β=99.390(5). These ambiguities are explained by stacking faults. The compounds absorb atmospheric moisture with c-axis expansion up to 29%. A delafossite-related superlattice Ag 3Co 2SbO 6 has been prepared by ion exchange and refined: P3 112, a=5.3842(2), c=18.6613(10). Ionic conductivity of the Na 0.8Ni 0.6Sb 0.4O 2 ceramics, 0.4 S/m at 300 °C, is greater than reported previously, presumably owing to the grain orientation produced by hot pressing.

Influence of Fe-substitution on structural, magnetic and magnetocaloric properties of Nd2Fe17-xCox solid solutions

NASA Astrophysics Data System (ADS)

Bouchaala, N.; Jemmali, M.; Bartoli, T.; Nouri, K.; Hentech, I.; Walha, S.; Bessais, L.; Salah, A. Ben

2018-02-01

Nd2Fe17-xCox (x = 0 , 1 , 2 , 3 , 4) intermetallic compounds, obtained under arc-melting conditions, have been investigated by means of X-ray diffraction analysis (XRD), Mössbauer spectrometry and magnetic measurements. The Rietveld refinement revealed that the sample is a pure compound with rhombohedral Th2Zn17-type structure (R 3 bar m space group) with the following lattice parameters: a = 8.5792 (2) Å, c = 12.4615 (2) Å. Using Mössbauer spectrometry analysis coupled with structural consideration we have unambiguously determined the cobalt atoms preferred inequivalent crystallographic site. Nd2Fe17 show an increase of 3.5 T in their weighted average hyperfine fields upon cobalt substitution. Whatever the cobalt content, the hyperfine field of these compounds follow this sequence Hhf { 6 c } >Hhf { 9 d } >Hhf { 18 f } >Hhf { 18 h }. The magnetic measurements showed that the Curie temperature increases with the Co content. The magnetic entropy change (ΔSM) was estimated from isothermal magnetization curves and it increases from 3.35 J/Kg K for x = 0 to 5.83 J/Kg K for x = 2 at μ0 H = 1.6 T . The relative cooling power (RCP) is in the range of 11.6 J/kg (x = 0) and 16 J/kg (x = 2).

The Toxicology of Perfluorodecanoic Acid in Rodents,

DTIC Science & Technology

Perfluoro -n-decanoic acid or nonadecafluoro-n-decanoic acid (NDFDA) is a straight chain, perfluorinated , ten-carbon acid. Experiments were conducted...to determine the LD50 and to evaluate survival times of rats after single intraperitoneal (IP) injections of NDFDA or of Fluorooctanoic acid ( PFOA ...experimental animals. With NDFDA, the LD50/14 days was 63.6 mg/kg, and the LD50/30 days was 41.4 mg/kg. With PFOA , there was no mortality after the 5th day following injection, and both the LD50/14 and LD50/30 were 188.7 mg/kg.

Radiosynthesis of the anticancer nucleoside analogue Trifluridine using an automated 18F-trifluoromethylation procedure† †Electronic supplementary information (ESI) available: 1H NMR and 13C NMR data for characterised compounds, automation setup, HPLC traces from radiosynthesis, Log D7.4 and radiotracer stability procedures, raw data and HPLC traces from all in vitro and in vivo studies. See DOI: 10.1039/c8ob00432c

PubMed Central

King, Alice; Doepner, Andreas; Turton, David; Ciobota, Daniela M.; Da Pieve, Chiara; Wong Te Fong, Anne-Christine; Kramer-Marek, Gabriela; Chung, Yuen-Li

2018-01-01

Trifluoromethyl groups are widespread in medicinal chemistry, yet there are limited 18F-radiochemistry techniques available for the production of the complementary PET agents. Herein, we report the first radiosynthesis of the anticancer nucleoside analogue trifluridine, using a fully automated, clinically-applicable 18F-trifluoromethylation procedure. [18F]Trifluridine was obtained after two synthetic steps in <2 hours. The isolated radiochemical yield was 3% ± 0.44 (n = 5), with a radiochemical purity >99%, and a molar activity of 0.4 GBq μmol–1 ± 0.05. Biodistribution and PET-imaging data using HCT116 tumour-bearing mice showed a 2.5 %ID g–1 tumour uptake of [18F]trifluridine at 60 minutes post-injection, with bone uptake becoming a prominent feature thereafter. In vivo metabolite analysis of selected tissues revealed the presence of the original radiolabelled nucleoside analogue, together with deglycosylated and phosphorylated [18F]trifluridine as the main metabolites. Our findings suggest a potential role for [18F]trifluridine as a PET radiotracer for elucidation of drug mechanism of action. PMID:29629716

[Ganoderma triterpenoids from aqueous extract of Ganoderma lucidum].

PubMed

Che, Xian-Qiang; Li, Shao-Ping; Zhao, Jing

2017-05-01

A new triterpenoid and 18 analogues were isolated from the water extract of Ganoderma lucidum by column chromatographic techniques, including silica gel, ODS, Sephadex LH-20, and HPLC. The new compound was elucidated as 2β-acetoxy-3β,25-dihydroxy-7,11,15-trioxo-lanost-8-en-26-oic acid on the basis of analyses of extensive spectroscopic data and its physicochemical properties. Comparison of NMR data with those reported in literature, the known analogues were determined as ganoderic acid H (2), 12β-acetoxy-3β,7β-dihydroxy-11,15,23-trioxo-lanost-8,16-dien-26-oic acid (3), ganoderenic acid D (4),ganoderic acid C1 (5),ganoderic acid G (6),3β,7β-dihydroxy-11,15,23-trioxo-lanost-8,16-dien-26-oic acid (7),ganoderic acid B (8),ganoderic acid C6 (9),3β,15α-dihydroxy-7,11,23-trioxo-lanost-8,16-dien-26-oic acid (10),ganoderic acid A (11),ganolucidic acid A (12),lucidenic acid E2 (13),lucidenic acid N (14),lucidenic acid P (15), lucidenic acid B (16),lucidenic acid A (17),lucidenic acid C (18),and lucidenic acid L (19), respectively. Compound 1 is new compound and compounds 2-19 have been reported from G. lucidum. The present study enriches the knowledge of the chemical constituent of G. lucidum and completes chemical investigation of water decoction that is traditional use of G. lucidum. Copyright© by the Chinese Pharmaceutical Association.

[Synthesis and biological activity of 2,3-secotriterpene acid mono- and diamides].

PubMed

Tolmacheva, I A; Igosheva, E V; Vikharev, Iu B; Grishko, V V; Savinova, O V; Boreko, E I; Eremin, V F

2013-01-01

Four types of amide (C3; C28; C3-C28) conjugates based on 2,3-seco-18alphaH-oleanane and 2,3-secolupane mono- and dicarboxylic acids were synthesized. The range of diamide derivatives was supplemented with C3-C3' and C28-C28' dicondensed amides with two A-secotriterpene backbones educed by reacting monocarboxylic A-secoacids with biogenic amino acid lysine. Compounds with inhibitory action against herpes virus reproduction (EC50 8.7 and 4.1 McM) were found among the synthesized mono- and diamide derivatives containing an ethyl-beta-alaninate fragment. It has been ascertained that diamide with ethyl-beta-alaninate fragment combines anti-herpes virus properties and anti-HIV activity (EC50 5.1 McM). For active compounds, the maximum non-toxic concentration (MNTC)/EC50 ratios ranges from 9.7 to 40.8. The synthesized amide conjugates do not exhibit any marked cytotoxic effects against human tumor cell lines rabdomiosarcoma RD TE32, A549 lung carcinoma and melanoma MS.

Characterization of Terpenoids from the Root of Ceriops tagal with Antifouling Activity

PubMed Central

Chen, Jun-De; Yi, Rui-Zao; Lin, Yi-Ming; Feng, Dan-Qing; Zhou, Hai-Chao; Wang, Zhan-Chang

2011-01-01

One new dimeric diterpenoid, 8(14)-enyl-pimar-2′(3′)-en-4′(18′)-en-15′(16′)-endolabr- 16,15,2′,3′-oxoan-16-one (1) and five known terpenoids: Tagalsin C (2), Tagalsin I (3), lup-20(29)-ene-3β,28-diol (4), 3-oxolup-20(29)-en-28-oic acid (5) and 28-hydroxylup- 20(29)-en-3-one (6) were isolated from the roots of the mangrove plant Ceriops tagal. Their structures and relative stereochemistry were elucidated by means of extensive NMR, IR and MS analysis. The antifouling activity against larval settlement of the barnacle Balanus albicostatus were evaluated using capsaicin as a positive control. All these terpenoids exhibited antifouling activity against cyprid larvae of the barnacle without significant toxicity. The structure-activity relationship results demonstrated that the order of antifouling activity was diterpenoid (Compound 2) > triterpenoid (Compounds 4, 5 and 6) > dimeric diterpenoid (Compounds 1 and 3). The functional groups on the C-28 position of lupane triterpenoid significantly affect the antifouling activity. The diterpenoid dimmer with two identical diterpenoid subunits might display more potent antifouling activity than one with two different diterpenoid subunits. The stability test showed that Compounds 2, 4, 5 and 6 remained stable over 2-month exposure under filtered seawater. PMID:22072902

Crystal structure of (18-crown-6)potassium(I) [(1,2,3,4,5-η)-cyclo-hepta-dien-yl][(1,2,3-η)-cyclo-hepta-trien-yl]cobalt(I).

PubMed

Brennessel, William W; Ellis, John E

2015-03-01

The reaction of bis-(anthracene)cobaltate(-I) with excess cyclo-hepta-triene, C7H8, resulted in a new 18-electron cobaltate containing two different seven-membered ring ligands, based on single-crystal X-ray diffraction. The asymmetric unit of this structure contains two independent cation-anion pairs of the title complex, [K(18-crown-6)][Co(η(3)-C7H7)(η(5)-C7H9)], where 18-crown-6 stands for 1,4,7,10,13,16-hexa-oxa-cyclo-octa-decane (C12H24O6), in general positions and well separated. Each (18-crown-6)potassium cation is in contact with the η(3)-coordinating ligand of one cobaltate complex. Each η(3)-coordinating ligand behaves as an allylic anion whose exo-diene moiety is bent away from the allylic plane, and thus is not involved directly in the bonding. The metal-coordinating portions of the anionic η(5) ligands are planar and one of these ligands is modeled as disordered over two positions, with occupancy ratio 0.699 (5):0.301 (5), such that one orientation is rotated by one carbon atom with respect to the other. The diffraction intensities were integrated according to non-merohedral twin law [-1 0 0/0 -1 0/0.064 0 1], a 180° rotation about reciprocal lattice axis [001], and the masses of the twin domains refined to equal amounts. As both ligands are formally coordinated as anions, the cobalt atom is best considered to be Co(I). This compound is of inter-est as the first to possess cyclo-hepta-trienyl and cyclo-hepta-dienyl ligands in an anionic metal complex.

Ba2F2Fe2+ 0.5Fe3+ S3: a two-dimensional inhomogeneous mixed valence iron compound.

PubMed

Kabbour, Houria; Cario, Laurent

2008-03-03

The structure of the new mixed valence compound Ba2F2Fe1.5S3 was solved by means of single crystal X-ray analysis. It crystallizes in an orthorhombic cell, in the Pnma space group with the cell parameters a = 12.528(3) A, b = 18.852(4) A, and c = 6.0896(12) A. The structure is formed by the alternated stacking of fluorite type [Ba2F2]2+ blocks and the newly discovered [Fe1.5S3]2- blocks. This [Fe1.5S3]2- block exhibits a mixed valence of iron with Fe(+II) located in octahedrons and Fe(+III) in tetrahedrons. Preliminary susceptibility measurements suggest a low dimensional antiferromagnetic behavior.

Carbonyl compounds emitted by a diesel engine fuelled with diesel and biodiesel-diesel blends: Sampling optimization and emissions profile

NASA Astrophysics Data System (ADS)

Guarieiro, Lílian Lefol Nani; Pereira, Pedro Afonso de Paula; Torres, Ednildo Andrade; da Rocha, Gisele Olimpio; de Andrade, Jailson B.

Biodiesel is emerging as a renewable fuel, hence becoming a promising alternative to fossil fuels. Biodiesel can form blends with diesel in any ratio, and thus could replace partially, or even totally, diesel fuel in diesel engines what would bring a number of environmental, economical and social advantages. Although a number of studies are available on regulated substances, there is a gap of studies on unregulated substances, such as carbonyl compounds, emitted during the combustion of biodiesel, biodiesel-diesel and/or ethanol-biodiesel-diesel blends. CC is a class of hazardous pollutants known to be participating in photochemical smog formation. In this work a comparison was carried out between the two most widely used CC collection methods: C18 cartridges coated with an acid solution of 2,4-dinitrophenylhydrazine (2,4-DNPH) and impinger bottles filled in 2,4-DNPH solution. Sampling optimization was performed using a 2 2 factorial design tool. Samples were collected from the exhaust emissions of a diesel engine with biodiesel and operated by a steady-state dynamometer. In the central body of factorial design, the average of the sum of CC concentrations collected using impingers was 33.2 ppmV but it was only 6.5 ppmV for C18 cartridges. In addition, the relative standard deviation (RSD) was 4% for impingers and 37% for C18 cartridges. Clearly, the impinger system is able to collect CC more efficiently, with lower error than the C18 cartridge system. Furthermore, propionaldehyde was nearly not sampled by C18 system at all. For these reasons, the impinger system was chosen in our study. The optimized sampling conditions applied throughout this study were: two serially connected impingers each containing 10 mL of 2,4-DNPH solution at a flow rate of 0.2 L min -1 during 5 min. A profile study of the C1-C4 vapor-phase carbonyl compound emissions was obtained from exhaust of pure diesel (B0), pure biodiesel (B100) and biodiesel-diesel mixtures (B2, B5, B10, B20, B50, B75). The ΣCC of the emission concentrations were 20.5 ppmV for B0 and 15.7 ppmV for B100. When considering fuel blends, the measured ΣCC were 21.4 ppmV, 22.5 ppmV, 20.4 ppmV, 14.2 ppmV, 11.4 ppmV and 14.7 ppmV, respectively, for B2, B5, B10, B20, B50 and B75. Among the target CC, both formaldehyde and acetaldehyde were the major contributors to the observed total CC levels. Except for acrolein and formaldehyde, all CC showed a clear trend of reduction in the emissions from B2 to B100 (40% reduction, on average). Both individual and total CC emission factors (pg g -1 of fuel burnt) were calculated for all tested biodiesel-diesel blends. The lowest total CC emission factor (2271 pg g -1) was found when B50 was used; the individual emission factors determined (pg g -1) were: 539.7 (formaldehyde), 1411 (acetaldehyde), 30.83 (acrolein), and 310.7 (propionaldehyde).

Simultaneous liquid chromatographic determination of metals and organic compounds in pharmaceutical and food-supplement formulations using evaporative light scattering detection.

PubMed

Spacil, Zdenek; Folbrova, Jana; Megoulas, Nikolaos; Solich, Petr; Koupparis, Michael

2007-02-05

A novel method for the non-derivatization liquid chromatographic determination of metals (potassium, aluminium, calcium and magnesium) and organic compounds (ascorbate and aspartate) was developed and validated based on evaporative light scattering detection (ELSD). Separation of calcium, magnesium and aluminium was achieved by the cation exchange column Dionex CS-14 and an aqueous TFA mobile phase according to the following time program: 0-6 min TFA 0.96 mL L(-1), 6-7 min linear gradient from TFA 0.96-6.4 mL L(-1). Separation of potassium, magnesium and aspartate was achieved by the lipophilic C18 Waters Spherisorb column and isocratic aqueous 0.2 mL L(-1) TFA mobile phase. Separation of sodium, magnesium, ascorbate and citrate was also achieved by the C18 analytical column, according to the following elution program: 0-2.5 min aqueous nonafluoropentanoic acid (NFPA) 0.5 mL L(-1); 2.5-3.5 min linear gradient from 0.5 mL L(-1) NFPA to 1.0 mL L(-1) TFA. In all cases, evaporation temperature was 70 degrees C, pressure of the nebulizing gas (nitrogen) 3.5 bar, gain 11 and the flow rate 1.0 mL min(-1). Resolution among calcium and magnesium was 1.8, while for all other separations was > or = 3.2. Double logarithmic calibration curves were obtained within various ranges from 3-24 to 34-132 microg mL(-1), and with good correlation (r>0.996). Asymmetry factor ranged from 0.9 to 1.9 and limit of detection from 1.3 (magnesium) to 17 microg mL(-1) (ascorbate). The developed method was applied for the assay of potassium, magnesium, calcium, aluminium, aspartate and ascorbate in pharmaceuticals and food-supplements. The accuracy of the method was evaluated using spiked samples (%recovery 95-105%, %R.S.D. < 2) and the absence of constant or proportional errors was confirmed by dilution experiments.

[Synthesis of porous spherical silicon oxynitride material and evaluation of its properties in reversed-phase chromatographic separation].

PubMed

Zhong, Hongmin; Zhang, Hua; Wan, Huihui

2013-04-01

Silica has been widely used as HPLC column packing material. However, the fact that base can attack the silanol and dissolve the silica embarrasses the utilization of silica stationary phase in high pH mobile phases (pH >8). In our previous research, the use of porous spherical silicon oxynitride (sph-SiON) material from high temperature nitridation of silica microspheres as stationary phase for HPLC has been explored, and the sph-SiON is stable to alkaline mobile phases and demonstrates excellent separation of a variety of polar compounds in hydrophilic interaction liquid chromatography (HILIC) mode. Herein, the degree of nitridation was studied as a function of temperature of nitridation at 750-1 050 degrees C, yielding the silicon oxynitride with 0.40%-12.0% (mass fraction) nitrogen from elemental analysis. At the temperature of 1 050 degrees C, the nitrogen content increased from 12.0% to 24.5% with the nitridation time increasing from 20 h to 120 h. The sph-SiON is stable when disposed in different pH aqueous solutions for one week. The sph-SiON material can be modified to give hydrophobic surface through the reaction of surface Si-NHx with dimethyloctadecylchlorosilane. Elemental analysis and 13C cross-polarization magic-angle spinning (CP/MAS) NMR spectrum of C18-sph-SiON prove the integration of C18 alkyl groups attached onto the sph-SiON surface. The chromatographic evaluation of C18-sph-SiON in reversed-phase separation mode was performed with alkylbenzenes as hydrophobic probes. Three alkylbenzene compounds can be separated and retained well on C18-sph-SiON even in the mobile phase of methanol/H2O (70/30, v/v) with 78 507 plates/m, and an excellent tailing factor (0.95) can be obtained for ethylbenzene. In comparison with C18-SiO2, C18-sph-SiON shows distinct differences with respect to different classes of analytes, i. e. neutral analyte naphthalene, acidic analyte ibuprofen, and basic analyte amitriptyline.

Cluster structure and Coulomb shift in two-center mirror systems

NASA Astrophysics Data System (ADS)

Nakao, M.; Umehara, H.; Sonoda, S.; Ebata, S.; Ito, M.

2017-11-01

The α + 14C elastic scattering and the nuclear structure of its compound systems, 18O = α + 14C, are analyzed on the basis of the semi-microscopic model. The α + 14C interaction potential is constructed from the double folding (DF) model with the effective nucleon-nucleon interaction of the density-dependent Michigan 3-range Yukawa. The DF potential is applied to the α+14C elastic scattering in the energy range of Eα/Aα = 5.5 8.8 MeV, and the observed differential cross sections are reasonably reproduced. The energy spectra of 18O are calculated by employing the orthogonality condition model (OCM) plus the absorbing boundary condition (ABC). The OCM + ABC calculation predicts the formation of the 0+ resonance around E = 3MeV with respect to the α threshold, which seems to correspond to the resonance identified in the recent experiment. We also apply the OCM + ABC calculation to the mirror system, such as 18Ne = α+14O, and the Coulomb shift of 18O - 18Ne is evaluated. We have found that the Coulomb shift is clearly reduced in the excited 0+ state due to the development of the α cluster structure. This result strongly supports that the Coulomb shift is a candidate of new probe to identify the clustering phenomena.

Synthesis and characterization of boric acid mediated metal-organic frameworks based on trimesic acid and terephthalic acid

NASA Astrophysics Data System (ADS)

Ozer, Demet; Köse, Dursun A.; Şahin, Onur; Oztas, Nursen Altuntas

2017-08-01

The new metal-organic framework materials based on boric acid reported herein. Sodium and boron containing metal-organic frameworks were synthesized by one-pot self-assembly reaction in the presence of trimesic acid and terephthalic acid in water/ethanol solution. Boric acid is a relatively cheap boron source and boric acid mediated metal-organic framework prepared mild conditions compared to the other boron source based metal-organic framework. The synthesized compounds were characterized by FT-IR, p-XRD, TGA/DTA, elemental analysis, 13C-MAS NMR, 11B-NMR and single crystal measurements. The molecular formulas of compounds were estimated as C18H33B2Na5O28 and C8H24B2Na2O17 according to the structural analysis. The obtained complexes were thermally stable. Surface properties of inorganic polymer complexes were investigated by BET analyses and hydrogen storage properties of compound were also calculated.

Lipstick dermatitis due to C18 aliphatic compounds.

PubMed

Hayakawa, R; Matsunaga, K; Suzuki, M; Arima, Y; Ohkido, Y

1987-04-01

An 18-year-old girl developed cheilitis. She had a past history of lip cream dermatitis, but the cause was not found. Patch tests with 2 lipsticks were strongly positive. Tests with the ingredients were positive to 2 aliphatic compounds, glyceryl diisostearate and diisostearyl malate. Impurities in the materials were suspected as the cause. Analysis by gas chromatography detected 3 chemicals in glyceryl diisostearate and 1 in diisostearyl malate as impurities. Patch testing with the impurities and glyceryl monoisostearate 0.01% pet in glyceryl diisostearate and isostearyl alcohol 0.25% pet in diisostearyl malate were strongly positive. The characteristics common to the 2 chemicals were liquidity at room temperature, branched C18 aliphatic compound and primary alcohol. Chemicals lacking any of the above 3 features did not react.

Nitroalkenes and sesquiterpene hydrocarbons from the frontal gland of three prorhinotermes termite species.

PubMed

Piskorski, Rafal; Hanus, Robert; Vasícková, Sona; Cvacka, Josef; Sobotník, Jan; Svatos, Ales; Valterová, Irena

2007-09-01

Frontal gland contents of soldiers of three Prorhinotermes species, Prorhinotermes canalifrons, Prorhinotermes inopinatus, and Prorhinotermes simplex, consisted of two groups of compounds: nitroalkenes and sesquiterpene hydrocarbons. Analysis by gas chromatography-mass spectrometry revealed (E)-1-nitropentadec-1-ene as the major component of the glands with mean values of 152, 207, and 293 microg/individual for P. canalifrons, P. inopinatus, and P. simplex, respectively. Four other 1-nitroalkenes (C13, C14, C16, and C17), and two nitrodienes (C15 and C17) were also detected in the three species. The C17:1 nitroalkene was identified as (E)-1-nitroheptadec-1-ene. The sesquiterpene composition of the gland was species-specific: P. simplex contained (3Z,6E)-alpha-farnesene (mean of 39 microg/individual), while P. canalifrons and P. inopinatus contained the same compound (means of 0.5 and 1.5 microg/individual, respectively) as well as the (3E,6E) isomer (means of 1.8 and 0.7 microg/individual, respectively). Two other sesquiterpenes, trans-beta-bergamotene and (Z)-gamma-bisabolene, were also found in low quantities in the frontal gland of P. canalifrons.

Ligand-Sensitive But Not Ligand-Diagnostic: Evaluating Cr Valence-to-Core X-ray Emission Spectroscopy as a Probe of Inner-Sphere Coordination

PubMed Central

2015-01-01

This paper explores the strengths and limitations of valence-to-core X-ray emission spectroscopy (V2C XES) as a probe of coordination environments. A library was assembled from spectra obtained for 12 diverse Cr complexes and used to calibrate density functional theory (DFT) calculations of V2C XES band energies. A functional dependence study was undertaken to benchmark predictive accuracy. All 7 functionals tested reproduce experimental V2C XES energies with an accuracy of 0.5 eV. Experimentally calibrated, DFT calculated V2C XES spectra of 90 Cr compounds were used to produce a quantitative spectrochemical series showing the V2C XES band energy ranges for ligands comprising 18 distinct classes. Substantial overlaps are detected in these ranges, which complicates the use of V2C XES to identify ligands in the coordination spheres of unknown Cr compounds. The ligand-dependent origins of V2C intensity are explored for a homologous series of [CrIII(NH3)5X]2+ (X = F, Cl, Br, and I) to rationalize the variable intensity contributions of these ligand classes. PMID:25496512

New quaternary ammonium camphor derivatives and their antiviral activity, genotoxic effects and cytotoxicity.

PubMed

Sokolova, Anastasiya S; Yarovaya, Capital O Cyrilliclga I; Shernyukov, Capital A Cyrillicndrey V; Pokrovsky, Capital Em Cyrillicichail A; Pokrovsky, Capital A Cyrillicndrey G; Lavrinenko, Valentina A; Zarubaev, Vladimir V; Tretiak, Tatiana S; Anfimov, Pavel M; Kiselev, Oleg I; Beklemishev, Anatoly B; Salakhutdinov, Nariman F

2013-11-01

The synthesis and biological evaluation of a novel series of dimeric camphor derivatives are described. The resulting compounds were studied for their antiviral activity, cyto- and genotoxicity. Compounds 3a and 3d in which the quaternary nitrogen atoms are separated by the C5H10 and С9H18 aliphatic chain, exhibited the highest efficiency as an agent inhibiting the reproduction of the influenza virus A(H1N1)pdm09. The cytotoxicity data of compounds 3 and 4 revealed their moderate activity against malignant cell lines; compound 3f had the highest activity for the CEM-13 cells. These results show close agreement with the data of independent studies on toxicity of these compounds, in particular that the toxicity of compounds strongly depends on spacer length. Copyright © 2013 Elsevier Ltd. All rights reserved.

Four new sesquiterpenes from the rhizomes of Curcuma phaeocaulis and their iNOS inhibitory activities.

PubMed

Ma, Jiang-Hao; Wang, Ying; Liu, Yue; Gao, Su-Yu; Ding, Li-Qin; Zhao, Feng; Chen, Li-Xia; Qiu, Feng

2015-05-01

Three new guaiane-type sesquiterpenes named phaeocaulisins K-M (1-3), and one germacrane-type sesquiterpenoid with new ring system of 1,5- and 1,8-ether groups named phagermadiol (4), were isolated from rhizomes of Curcuma phaeocaulis. Their structures were established based on extensive spectroscopic analysis. Compound 1, the first example of norsesquiterpene with tropone backbone, and compound 3 with a novel 1,2-dioxolane sesquiterpene alcohol were isolated from the genus Curcuma. All of the isolated compounds were tested for inhibitory activity against lipopolysaccharide-induced nitric oxide (NO) production in RAW 264.7 macrophages. Compound 3 inhibited NO production with IC50 value of 6.05 ± 0.43 μM. The plausible biosynthetic pathway for compounds 3 and 4 in C. phaeocaulis was also discussed.

Actinomyces weissii sp. nov., isolated from dogs.

PubMed

Hijazin, Muaz; Alber, Jörg; Lämmler, Christoph; Kämpfer, Peter; Glaeser, Stefanie P; Busse, Hans-Jürgen; Kassmannhuber, Johannes; Prenger-Berninghoff, Ellen; Förnges, Thorsten; Hassan, Abdulwahed Ahmed; Abdulmawjood, Amir; Zschöck, Michael

2012-08-01

Two Gram-positive, rod-shaped, non-spore-forming bacteria were isolated from the oral cavities of two dogs. On the basis of 16S rRNA gene sequence similarities both strains were shown to belong to the genus Actinomyces and were most closely related to Actinomyces bovis (97.3% and 97.5%, respectively). The polyamine profile of the two isolates and Actinomyces bovis DSM 43014(T) was composed of spermidine and spermine as the major components. Menaquinone MK-9 was the major compound in the quinone system of the two strains and Actinomyces bovis. The polar lipid profiles of strains 2298(T) and 4321 were almost identical, containing diphosphatidylglycerol as the major compound, and moderate to trace amounts of phosphatidylcholine, phosphatidylinositol, phosphatidylinositol-mannoside, phosphatidylglycerol and several unidentified lipids. A highly similar polar lipid profile was detected in Actinomyces bovis DSM 43014(T) supporting the affiliation of strains 2298(T) and 4321 to the genus Actinomyces. The typical major fatty acids were C(16:0), C(18:0) and C(18:1)ω9c. Fatty acids C(14:0) and C(18:2)ω6,9c were found in minor amounts. The results of physiological and biochemical analyses revealed clear differences between both strains and the most closely related species of the genus Actinomyces. Thus, strains 2298(T) and 4321 represent a novel species, for which the name Actinomyces weissii sp. nov., is proposed, with strain 2298(T) ( = CIP 110333(T) = LMG 26472(T) = CCM 7951(T) = CCUG 61299(T)) as the type strain.

Characterization and Application of Passive Samplers for Monitoring of Pesticides in Water.

PubMed

Ahrens, Lutz; Daneshvar, Atlasi; Lau, Anna E; Kreuger, Jenny

2016-08-03

Five different water passive samplers were calibrated under laboratory conditions for measurement of 124 legacy and current used pesticides. This study provides a protocol for the passive sampler preparation, calibration, extraction method and instrumental analysis. Sampling rates (RS) and passive sampler-water partition coefficients (KPW) were calculated for silicone rubber, polar organic chemical integrative sampler POCIS-A, POCIS-B, SDB-RPS and C18 disk. The uptake of the selected compounds depended on their physicochemical properties, i.e., silicone rubber showed a better uptake for more hydrophobic compounds (log octanol-water partition coefficient (KOW) > 5.3), whereas POCIS-A, POCIS-B and SDB-RPS disk were more suitable for hydrophilic compounds (log KOW < 0.70).

Stereochemistry of C18 monounsaturated cork suberin acids determined by spectroscopic techniques including (1) H-NMR multiplet analysis of olefinic protons.

PubMed

Santos, Sara; Graça, José

2014-01-01

Suberin is a biopolyester responsible for the protection of secondary plant tissues, and yet its molecular structure remains unknown. The C18:1 ω-hydroxyacid and the C18:1 α,ω-diacid are major monomers in the suberin structure, but the configuration of the double bond remains to be elucidated. To unequivocally define the configuration of the C18:1 suberin acids. Pure C18:1 ω-hydroxyacid and C18:1 α,ω-diacid, isolated from cork suberin, and two structurally very close C18:1 model compounds of known stereochemistry, methyl oleate and methyl elaidate, were analysed by NMR spectroscopy, Fourier transform infrared (FTIR) and Raman spectroscopy, and GC-MS. The GC-MS analysis showed that both acids were present in cork suberin as only one geometric isomer. The analysis of dimethyloxazoline (DMOX) and picolinyl derivatives proved the double bond position to be at C-9. The FTIR spectra were concordant with a cis-configuration for both suberin acids, but their unambiguous stereochemical assignment came from the NMR analysis: (i) the chemical shifts of the allylic (13) C carbons were shielded comparatively to the trans model compound, and (ii) the complex multiplets of the olefinic protons could be simulated only with (3) JHH and long-range (4) JHH coupling constants typical of a cis geometry. The two C18:1 suberin acids in cork are (Z)-18-hydroxyoctadec-9-enoic acid and (Z)-octadec-9-enedoic acid. Copyright © 2013 John Wiley & Sons, Ltd.

α-Pyrone derivatives with cytotoxic activities, from the endophytic fungus Phoma sp. YN02-P-3.

PubMed

Sang, Xia-Nan; Chen, Shao-Fei; Tang, Ming-Xu; Wang, Hai-Feng; An, Xiao; Lu, Xiao-Jie; Zhao, Dan; Wang, Yu-Bo; Bai, Jiao; Hua, Hui-Ming; Chen, Gang; Pei, Yue-Hu

2017-08-15

Four new α-pyrone derivatives phomones C-F (1-4) together with four known compounds (5-8) were isolated from the endophytic fungus Phoma sp. YN02-P-3. Compound 1 is the first example of 6-α,β-unsaturated ester-2-pyrone dimers via intermolecular symmetrical [2+2] cycloaddition. The chemical structures of these compounds were determined from spectroscopic data (1D/2D NMR, MS and IR). The acetylated product (9) of 1 along with compounds 1-8 were then tested for their cytotoxicity against HL-60, PC-3 and HCT-116 cell lines. Compounds 2, 3, 5 and 9 with acetyl groups showed significant inhibitory activities against the three cell lines with IC 50 values in the range 0.52-9.85μM. while compounds 1, 4 and 6-8 that possess no acetyl group showed no inhibitory activity (IC 50 >50μM), indicating that the acetyl group at 10- or 12- are essential for their cytotoxic activities. The structure-activity relationships of these phomones were also reported. Copyright © 2017 Elsevier Ltd. All rights reserved.

Crystal structure of fac-[2-(4-methyl-5-phenyl-pyridin-2-yl)phenyl-κ2C1,N]bis-[2-(pyridin-2-yl)phenyl-κ2C1,N]iridium(III).

PubMed

Lee, Chi-Heon; Moon, Suk-Hee; Park, Ki-Min; Kang, Youngjin

2016-12-01

In the title compound, [Ir(C 11 H 8 N) 2 (C 18 H 14 N)], the Ir III ion adopts a distorted octa-hedral coordination environment defined by three C , N -chelating ligands, one stemming from a 2-(4-phenyl-5-methyl-pyridin-2-yl)phenyl ligand and two from 2-(pyridin-2-yl)phenyl ligands, arranged in a facial manner. The Ir III ion lies almost in the equatorial plane [deviation = 0.0069 (15) Å]. In the crystal, inter-molecular π-π stacking inter-actions, as well as inter-molecular C-H⋯π inter-actions, are present, leading to a three-dimensional network.

Four new bioactive manzamine-type alkaloids from the Philippine marine sponge Xestospongia ashmorica.

PubMed

Edrada, R A; Proksch, P; Wray, V; Witte, L; Müller, W E; Van Soest, R W

1996-11-01

Analysis of the Philippine marine sponge Xestospongia ashmorica afforded four new manzamine congeners 1-4 and four known compounds 5 and 7-9. Compound 1 is the 6-deoxy derivative of manzamine X, while 2-4 are the N-oxides of manzamine J (5), 3,4-dihydromanzamine A (6), and manzamine A (7), respectively. The structures of the new compounds were unambiguously established on the basis of NMR spectroscopic (1H, 13C, COSY, 1H-detected direct, and long-range 13C-1H correlations) and mass spectrometric (EI, FAB-MS, and electrospray ionization) data. Alkaloid N-oxide structures were confirmed by conversion to the corresponding tertiary bases by reduction with Zn/HCl. This is the first report of the occurrence of bioactive manzamine N-oxides in marine sponges. Compound 7 exhibited insecticidal activity toward neonate larvae of the polyphagous pest insect Spodoptera littoralis (with an ED50 of 35 ppm) when incorporated in artificial diet and offered to larvae in a chronic feeding bioassay. Compound 7 was also active against the Gram-positive bacteria Bacillus subtilis and Staphylococcus aureus. Cytotoxicity was studied in vitro using L1578y mouse lymphoma cells. From the alkaloids studied, the N-oxides 3 and 4 were the most active (ED50 = 1.6 micrograms/mL) followed by compound 7 (ED50 = 1.8 micrograms/mL).

Evaluation of the phase ratio for three C18 high performance liquid chromatographic columns.

PubMed

Caiali, Edvin; David, Victor; Aboul-Enein, Hassan Y; Moldoveanu, Serban C

2016-02-26

For a chromatographic column, phase ratio Φ is defined as the ratio between the volume of the stationary phase Vst and the void volume of the column V0, and it is an important parameter characterizing the HPLC process. Although apparently simple, the evaluation of Φ presents difficulties because there is no sharp boundary between the mobile phase and the stationary phase. In addition, the boundary depends not only on the nature of the stationary phase, but also on the composition of the mobile phase. In spite of its importance, phase ratio is seldom reported for commercially available HPLC columns and the data typically provided by the vendors about the columns do not provide key information that would allow the calculation of Φ based on Vst and V0 values. A different procedure for the evaluation of Φ is based on the following formula: log k'j=a log Kow,j+log Φ, where k'j is the retention factor for a compound j that must be a hydrocarbon, Kow,j is the octanol/water partition coefficient, and a is a proportionality constant. Present study describes the experimental evaluation of Φ based on the measurement of k'j for the compounds in the homologous series between benzene and butylbenzene for three C18 columns: Gemini C18, Luna C18 both with 5 μm particles, and a Chromolith Performance RP-18. The evaluation was performed for two mobile phase systems at different proportions of methanol/water and acetonitrile/water. The octanol/water partition coefficients were obtained from the literature. The results obtained in the study provide further support for the new procedure for the evaluation of phase ratio. Copyright © 2016 Elsevier B.V. All rights reserved.

Di-tert-butyl­bis(N-isopropyl-N-methyl­dithio­carbamato-κ2 S,S′)tin(IV)

PubMed Central

Muthalib, Amirah Faizah; Baba, Ibrahim; Samsudin, Mohd Wahid; Ng, Seik Weng

2010-01-01

The dithio­carbamate anions in the title compound, [Sn(C4H9)2(C5H10NS2)2], chelate to the SnIV atom, which is six-coordinated in a skew-trapezoidal-bipyramidal geometry. The mol­ecule lies across a twofold rotation axis. The crystal studied was a non-merohedral twin, the ratio of the twin components being 0.82 (1):0.18 (1). PMID:21580471

Phenolic antioxidants from green tea produced from Camellia crassicolumna Var. multiplex.

PubMed

Liu, Qing; Zhang, Ying-Jun; Yang, Chong-Ren; Xu, Mei

2009-01-28

Camellia crassicolumna var. multiplex (Chang et Tan) Ming belonging to Camellia sect. Thea (Theaceae), is endemic to the southeastern area of Yunnan province, China, where the leaves have been commonly used for making tea and beverages consumed widely. HPLC analysis showed that there was no caffeine or theophylline contained in the leaves; however, thin layer chromatography (TLC) analysis suggested the abundant existence of phenolic compounds. Further detailed chemical investigation of the green tea produced from the leaves of the plant led to the identification of 18 phenolic compounds, including four flavan-3-ols (1-4), six flavonol glycosides (5-10), three hydrolyzable tannins (11-13), two chlorogenic acid derivatives (14, 15), and three simple phenolic compounds (16-18). The isolated compounds were evaluated for their antioxidant activities by 1,1'-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging and tyrosinase inhibitory assays. Most of them exhibited significant DPPH radical scavenging activities, whereas flavan-3-ols and hydrolyzable tannins showed stronger inhibitory activities on tyrosinase. The results suggest that C. crassicolumna could be an ideal plant resource for a noncaffeine beverage.

Novel phenanthrene and isocoumarin from the rhizomes of Dioscorea nipponica Makino subsp. rosthornii (Prain et Burkill) C. T. Ting (Dioscoreaceae).

PubMed

Li, Xuejiao; Zhao, Chengcheng; Jing, Songsong; Sun, Jiachen; Li, Xia; Man, Shuli; Wang, Ying; Gao, Wenyuan

2017-08-01

The investigation of the constituents in the rhizomes of Dioscorea nipponica Makino subsp. rosthornii (Prain et Burkill) C. T. Ting afforded one new phenanthrene 2,2',7,7'-tetramethoxy-[1,1'-biphenanthrene]-4,4',6,6'-tetrol (7) and one new isocoumarin diorosthornoumarin (8), together with 16 known compounds (1-6 and 9-18). Their structures were established on the basis of extensive spectroscopic evidences (IR, HR-ESI-MS, NMR and optical rotation), as well as comparison with literature values. All the compounds 1-18 were firstly isolated from Dioscorea nipponica Makino subsp. Rosthornii (Prain et Burkill) C. T. Ting, and compound 9 was firstly obtained as a natural product from plants, while the compounds 11 and 14 were obtained from both the genus Dioscorea and the family Dioscoreaceae for the first time. Moreover, the antitumor activities of the compounds were tested against lung carcinoma NCI-H460 cell line. Compound 12, 13, 15 and 16 showed significant cytotoxic activities, whereas 7 displayed moderate cytotoxicity. Copyright © 2017 Elsevier Ltd. All rights reserved.

Coordination trends in alkali metal crown ether uranyl halide complexes: the series [A(crown)]2[UO(2)X(4)] where A=Li, Na, K and X=Cl, Br.

PubMed

Danis, J A; Lin, M R; Scott, B L; Eichhorn, B W; Runde, W H

2001-07-02

UO(2)(C(2)H(3)O(2))(2).2H(2)O reacts with AX or A(C(2)H(3)O(2) or ClO(4)) (where A = Li, Na, K; X = Cl, Br) and crown ethers in HCl or HBr aqueous solutions to give the sandwich-type compounds [K(18-crown-6)](2)[UO(2)Cl(4)] (1), [K(18-crown-6)](2)[UO(2)Br(4)] (2), [Na(15-crown-5)](2)[UO(2)Cl(4)] (3), [Na(15-crown-5)](2)[UO(2)Br(4)] (4), [Li(12-crown-4)](2)[UO(2)Cl(4)] (5), and [Li(12-crown-4)](2)[UO(2)Br(4)] (6). The compounds have been characterized by single-crystal X-ray diffraction, powder diffraction, elemental analysis, IR, and Raman spectroscopy. The [UO(2)X(4)](2-) ions coordinate to two [A(crown)](+) cations through the four halides only (2), through two halides only (3), through the two uranyl oxygens and two halides (3, 4), or through the two uranyl oxygen atoms only (5, 6). Raman spectra reveal nu(U-O) values that correlate with expected trends. The structural trends are discussed within the context of classical principles of hard-soft acid-base theory.

The structure directing effect of organic cations onto the crystal structures of layered thioantimonates(III): Solvothermal synthesis and crystal structures of five new compounds containing the 2∞[Sb 8S 13] 2- anion

NASA Astrophysics Data System (ADS)

Puls, Angela; Näther, Christian; Kiebach, Ragnar; Bensch, Wolfgang

2006-09-01

The five new thioantimonates(III) ( iprH) 2[Sb 8S 13] ( I), (1,2-dapH) 2[Sb 8S 13] ( II), (1,3-dapH 2)[Sb 8S 13] ( III), (dienH 2)[Sb 8S 13]ṡ1.5H 2O ( IV), and (C 6H 9N 2)[Sb 8S 13]ṡ2.5H 2O ( V) were synthesised under solvothermal conditions ( ipr = iso-propylamine; 1,2-dap = 1,2-diaminopropane; 1,3-dap = 1,3-diaminopropane; dien = diethylentriamine; C 6H 9N 2 = 3-(aminoethyl)-pyridine). The structures of compounds I and II are topological very similar and a central motif is a Sb 10S 10 ring. On both sides of this ring Sb 5S 5 rings are condensed. These rings are connected via Sb 4S 4 rings leading to the sequence Sb 10S 10-Sb 5S 5-Sb 4S 4-Sb 5S 5-Sb 10Sb 10 in the [010] direction. Further interconnection into the two-dimensional [Sb 8S 13] 2- anion produces a large central Sb 18S 18 ring with dimensions of 11ṡ11 Å in both compounds. The two atoms thick layers are linear and stacked along the a axis generating large channels running along [010]. The layered anion of compound III is constructed by interconnection of the SbS 3 and SbS 4 units yielding Sb 19S 19, Sb 14S 14, Sb 13S 13, and Sb 8S 8 rings. The linear layers are two atoms thick and are stacked perpendicular to [001] to form channels running along the same direction. The last two compounds IV and V show a similar network topology. The layered anion is constructed by SbS 3 trigonal pyramids and SbS 4 units. The layer contains a Sb 12S 12 rings as the main structural motif. The corrugated layers extending in the (100) plane are two atoms thick and are stacked in a manner that large tunnels run along [100]. The total potential solvent areas are large and range from 20.7% for III to 35% for II.

Poly-N-Isopropylacrylamide/acrylic Acid Copolymers for the Generation of Nanostructures at Mica Surfaces and as Hydrophobic Host Systems for the Porin MspA from Mycobacterium smegmatis.

PubMed

Gamage, Pubudu; Basel, Matthew T; Lovell, Kimberly; Pokhrel, Megh Raj; Battle, Deletria; Ito, Takashi; Pavlenok, Mikhail; Niederweis, Michael; Bossmann, Stefan H

2009-09-17

The work presented here aims at utilizing poly-N-isopropyl-acrylamide/acrylic acid copolymers to create nanostructured layers on mica surfaces by a simple spin-casting procedure. The average composition of the copolymers determined by elemental analysis correlates excellently with the feed composition indicating that the radical polymerization process is statistical. The resulting surfaces were characterized by Atomic Force Microscopy (magnetic AC-mode) at the copolymer/air interface. Postpolymerization modification of the acrylic acid functions with perfluoro-octyl-iodide decreased the tendency towards spontaneous formation of nanopores. Crosslinking of individual polymer chains permitted the generation of ultraflat layers, which hosted the mycobacterial channel protein MspA, without compromising its channel function. The comparison of copolymers of very similar chemical composition that have been prepared by living radical polymerization and classic radical polymerization indicated that differences in polydispersity played only a minor role when poly-N-isopropyl-acrylamide/acrylic acid copolymers were spincast, but a major role when copolymers featuring the strongly hydrophobic perfluoro-octyl-labels were used. The mean pore diameters were 23.8+/-4.4 nm for P[(NIPAM)(95.5)-co-(AA)(4.5)] (PDI (polydispersity index)=1.55) and 21.8+/-4.2 nm for P[(NIPAM)(95.3)-co-(AA)(4.7)] (PDI=1.25). The depth of the nanopores was approx. 4 nm. When depositing P[(NIPAM)(95)-co-(AA)(2.8)-AAC(8)F(17 2.2)] (PDI=1.29) on Mica, the resulting mean pore diameter was 35.8+/-7.1 nm, with a depth of only 2 nm.

Poly-N-Isopropylacrylamide/acrylic Acid Copolymers for the Generation of Nanostructures at Mica Surfaces and as Hydrophobic Host Systems for the Porin MspA from Mycobacterium smegmatis

PubMed Central

Gamage, Pubudu; Basel, Matthew T.; Lovell, Kimberly; Pokhrel, Megh Raj; Battle, Deletria; Ito, Takashi; Pavlenok, Mikhail; Niederweis, Michael

2009-01-01

The work presented here aims at utilizing poly-N-isopropyl-acrylamide/acrylic acid copolymers to create nanostructured layers on mica surfaces by a simple spin-casting procedure. The average composition of the copolymers determined by elemental analysis correlates excellently with the feed composition indicating that the radical polymerization process is statistical. The resulting surfaces were characterized by Atomic Force Microscopy (magnetic AC-mode) at the copolymer/air interface. Postpolymerization modification of the acrylic acid functions with perfluoro-octyl-iodide decreased the tendency towards spontaneous formation of nanopores. Crosslinking of individual polymer chains permitted the generation of ultraflat layers, which hosted the mycobacterial channel protein MspA, without compromising its channel function. The comparison of copolymers of very similar chemical composition that have been prepared by living radical polymerization and classic radical polymerization indicated that differences in polydispersity played only a minor role when poly-N-isopropyl-acrylamide/acrylic acid copolymers were spincast, but a major role when copolymers featuring the strongly hydrophobic perfluoro-octyl-labels were used. The mean pore diameters were 23.8±4.4 nm for P[(NIPAM)95.5-co-(AA)4.5] (PDI (polydispersity index)=1.55) and 21.8±4.2 nm for P[(NIPAM)95.3-co-(AA)4.7] (PDI=1.25). The depth of the nanopores was approx. 4 nm. When depositing P[(NIPAM)95-co-(AA)2.8-AAC8F17 2.2] (PDI=1.29) on Mica, the resulting mean pore diameter was 35.8±7.1 nm, with a depth of only 2 nm. PMID:20161351

Fate and transport of perfluoro- and polyfluoroalkyl substances including perfluorooctane sulfonamides in a managed urban water body.

PubMed

Nguyen, Tung V; Reinhard, Martin; Chen, Huiting; Gin, Karina Y-H

2016-06-01

Transport and fate of perfluoro- and polyfluoroalkyl substances (PFASs) in an urban water body that receives mainly urban runoff was investigated. Water, suspended solids, and sediment samples were collected during the monsoon (wet) and inter-monsoon (dry) season at different sites and depths. Samples were analyzed for C7 to C12 perfluoroalkyl carboxylate homologues (PFCAs) (PFHpA, PFOA, PFNA, PFDA, PFUnA, PFDoA), perfluorohexane, perfluorooctane, and 6:2-fluorotelomer sulfonate (PFHxS, PFOS, and 6:2FtS, respectively), perfluorooctane sulfonamide (FOSA), N-ethyl FOSA (sulfluramid), N-ethyl sulfonamidoethanol (N-EtFOSE), and N-methyl and N-ethyl sulfonamidoacetic acid (N-EtFOSAA and N-MeFOSAA, respectively). Concentrations in wet samples were only slightly higher. The sum total PFAS (ΣPFAS) concentrations dissolved in the aqueous phase and sorbed to suspended solids (SS) ranged from 107 to 253 ng/L and 11 to 158 ng/L, respectively. PFOA, PFOS, PFNA, PFHxS, and PFDA contributed most (approximately 90 %) to the dissolved ΣPFASs. N-EtFOSA dominated the particulate PFAS burden in wet samples. K D values of PFOA and PFOS calculated from paired SS and water concentrations varied widely (1.4 to 13.7 and 1.9 to 98.9 for PFOA and PFOS, respectively). Field derived K D was significantly higher than laboratory K D suggesting hydrophobic PFASs sorbed to SS resist desorption. The ΣPFAS concentrations in the top sedimentary layer ranged from 8 to 42 μg/kg and indicated preferential accumulation of the strongly sorbing long-chain PFASs. The occurrence of the metabolites N-MeFOSAA, N-EtFOSAA and FOSA in the water column and sediments may have resulted from biological or photochemical transformations of perfluorooctane sulfonamide precursors while the absence of FOSA, N-EtFOSA and 6:2FtS in sediments was consistent with biotransformation.

Determination of fluorotelomer alcohols in selected consumer products and preliminary investigation of their fate in the indoor environment.

PubMed

Liu, Xiaoyu; Guo, Zhishi; Folk, Edgar E; Roache, Nancy F

2015-06-01

The U.S. Environmental Protection Agency (EPA) has established an ongoing effort to identify the major perfluorocarboxylic acid (PFCA) sources in nonoccupational indoor environments and characterize their transport and fate. This study determined the concentrations of fluorotelomer alcohols (FTOHs), which are the precursors to PFCAs, in fifty-four consumer products collected from the U.S. open market in the years of 2011 and 2013. The products included carpet, commercial carpet-care liquids, household carpet/fabric-care liquids, treated apparel, treated home textiles, treated non-woven medical garments, floor waxes, food-contact paper, membranes for apparel, and thread-sealant tapes. The FTOHs quantified were 1H,1H,2H,2H-perfluoro-1-octanol (6:2 FTOH), 1H,1H,2H,2H-perfluoro-1-decanol (8:2 FTOH), and 1H,1H,2H,2H-perfluoro-1-dodecanol (10:2 FTOH). The content of 6:2 FTOH ranged from non-delectable to 331μgg(-1), 8:2 FTOH from non-delectable to 92μgg(-1), and 10:2 FTOH from non-detectable to 24μgg(-1). In addition, two consumer products from the home textile category were tested in the washing-drying process. One product from the treated apparel category and one from the home textile category were tested in the micro-scale chamber under elevated temperatures. The experimental data show that the washing-drying process with one cycle did not significantly reduce the FTOH concentrations in the tested consumer products. FTOH off-gassing was observed under accelerated aging conditions. Future tests should include air sampling to allow determination of the absolute emission rates at different temperatures. The results of this study should be informative to exposure assessment and risk management. Published by Elsevier Ltd.

Near Infrared Phosphorescent, Non-oxidizable Palladium and Platinum Perfluoro-phthalocyanines.

PubMed

Łapok, Łukasz; Obłoza, Magdalena; Gorski, Alexandr; Knyukshto, Valeri; Raichyonok, Tamara; Waluk, Jacek; Nowakowska, Maria

2016-04-18

New Pd(II) and Pt(II) complexes with a highly electron-deficient ligand (H2 PcF64 ) were conveniently prepared in a three-step synthesis. This is the first time that the phosphorescence of phthalocyanines with a H2 PcF64 framework has been measured. Based on these measurements, the triplet-state energies (ET ) were directly determined. Transient absorption experiments revealed broad T1 →Tn absorption spanning from ca. 350 to ca. 1000 nm and allowed determination of the triplet-state lifetimes. Removal of the Pd or Pt from the perfluoro-phthalocyanine resulted in a significant increase of the triplet lifetime for H2 PcF64 . The very efficient intersystem crossing observed for both PdPcF64 and PtPcF64 leads to residual fluorescence and suppresses the fluorescence lifetimes to less than 50 ps. The absence of Pd and Pt in the perfluoro-phthalocyanine ligand, viz. H2 PcF64 , led to a recovery of fluorescence. Cyclic voltamperometry studies pointed to complete resistance of PdPcF64 and PtPcF64 to oxidation and very strong electron affinity, which rendered these materials very good electron acceptors (n-type materials). The presence of d-orbital metals such as Pd(II) and Pt(II) in the phthalocyanine ring stabilizes their reduced forms, as indicated by the spectroelectrochemical experiments. PdPcF64 and PtPcF64 easily sensitize singlet oxygen production with very high quantum yields. Both phthalocyanines presented resistance to photodegradation in the solid state under aerobic conditions and under intense irradiation. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

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

Walton, B.T.; Maggart, E.F. Jr.

Cuticular and gastrointestinal penetration, in vivo metabolism, and excretion of (/sup 14/C)acridine were investigated in the nymphal cricket Acheta domesticus (L.) to find a pharmacodynamic basis for this insect's differential susceptibility to acridine at different life stages. Topically applied (/sup 14/C)acridine readily penetrated the cuticular exoskeleton of nymphs (half-time of penetration, 48 min). Radiolabeled compounds appeared in the hemolymph within 0.5 h after ingestion of (/sup 14/C)acridine and continued to move across the gut wall for 7.5 h. The biological half-time was 18 h and the rate constant for elimination was 0.039 h/sup -1/ after ingestion. Within 5 d aftermore » dosing, 97% of the dose was excreted. Several metabolites were present in the feces of nymphs fed (/sup 14/C)acridine, and less than 13% of the extractable radioactivity was parent compound. The cuticule and the gastrointestinal tract proved to be ineffective barriers to acridine entry in A. domesticus. However, the ability to readily metabolize and excrete acridine probably contributes to the higher acridine tolerance observed in the nymphs and adults than in the eggs, which are susceptible to toxic effects. Acridine is found in many coal and synthetic fuel by-products.« less

Enhancing the understanding of earthworm feeding behaviour via the use of fatty acid delta13C values determined by gas chromatography-combustion-isotope ratio mass spectrometry.

PubMed

Dungait, Jennifer A J; Briones, Maria J I; Bol, Roland; Evershed, Richard P

2008-06-01

Litter-dwelling (epigeic) Lumbricus rubellus and soil-dwelling (endogeic) Allolobophora chlorotica earthworms were observed aggregating under C(3) (delta(13)C = -31.3 per thousand; delta(15)N = 10.7 per thousand) and C(4) (delta(13)C = -12.6 per thousand; delta(15)N = 7.5 per thousand) synthetic dung pats applied to a temperate grassland (delta(13)C = -30.3 per thousand; delta(15)N = 5.7 per thousand) in an experiment carried out for 372 days. Bulk delta(13)C values of earthworms collected from beneath either C(3) or C(4) dung after 28, 56, 112 and 372 days demonstrated that (i) L. rubellus beneath C(4) dung were significantly (13)C-enriched after 56 days (delta(13)C = -23.8 per thousand) and 112 days (delta(13)C = -22.4 per thousand) compared with those from C(3) dung treatments (56 days, delta(13)C = -26.5 per thousand; 112 days, delta(13)C = -27.0 per thousand), and (ii) A. chlorotica were 2.1 per thousand (13)C-enriched (delta(13)C = -24.2 per thousand) relative to those from C(3) dung (delta(13)C = -26.3 per thousand) treatments after 372 days. Bulk delta(15)N values did not suggest significant uptake of dung N by either species beneath C(3) or C(4) dung, but showed that the endogeic species (total mean delta(15)N = 3.3 per thousand) had higher delta(15)N values than the epigeic species (total mean delta(15)N = 5.4 per thousand). Although the two species exhibited similar fatty acid profiles, individual fatty acid delta(13)C values revealed extensive routing of dietary C into body tissue of L. rubellus, but minor incorporation into A. chlorotica. In particular, the direct incorporation of microbial biomarker fatty acids (iC(17:0), aC(17:0)) from (13)C-labelled dung in situ, the routing of dung C into de novo synthesised compounds (iC(20:4)(omega)(6),C(20:5)(omega)(3), and the assimilation of essential fatty acids ((C(18:1)(omega)(9), C(18:1)(omega(7), C(18:2)(omega(6), C(18:3)(omega)(3)) derived from dung, were determined. John Wiley & Sons, Ltd

Magnetic Droplet Microfluidics as a Platform for the Concentration of [18F]Fluoride and Radiosynthesis of Sulfonyl [18F]Fluoride.

PubMed

Fiel, Somewhere A; Yang, Hua; Schaffer, Paul; Weng, Samuel; Inkster, James A H; Wong, Michael C K; Li, Paul C H

2015-06-17

The radioisotope 18F is often considered the best choice for positron emission tomography (PET) owing to its desirable chemical and radiochemical properties. However, nucleophilic 18F-fluorination of large, water-soluble biomolecules, based on C-F bond formation, has traditionally been difficult. Thus, several aqueous fluorination approaches that offer significant versatility in radiopharmaceutical synthesis with sensitive targeting vectors have been developed. Furthermore, because 18F decays rapidly, production of these 18F-labeled compounds requires an automated process to reduce production time, reduce radiation exposure, and minimize losses due to the transfer of reagents during tracer synthesis. Herein, we report the use of magnetic droplet microfluidics (MDM) as a means to concentrate [18F]fluoride from the cyclotron target solution, followed by the synthesis of an 18F-labeled compound on a microfluidic platform. Using this method, we have demonstrated 18F preconcentration in a small-volume droplet through the use of anion exchanging magnetic particles. By using MDM, the preconcentration step took approximately 5 min, and the [18F]fluoride solution was preconcentrated by 15-fold. After the preconcentration step, an 18F-labeling reaction was performed on the MDM platform using the S-F bond formation in aqueous conditions to produce an arylsulfonyl [18F]fluoride compound which can be used as a prosthetic group to label PET targeting ligands. The high radiochemical purity of 95±1% was comparable to the 96% previously reported using a conventional method. In addition, when MDM was used, the total synthesis time was improved to 15 min with lower reagent volumes (50-60 μL) used.

Effect of pH, temperature, and moisture on the formation of volatile compounds in glycine/glucose model systems.

PubMed

Ames, J M; Guy, R C; Kipping, G J

2001-09-01

Mixtures of glycine, glucose, and starch were extrusion cooked using sodium hydroxide at 0, 3, and 6 g/L of extruder water feed, 18% moisture, and 120, 150, and 180 degrees C target die temperatures, giving extrudates with pH values of 5.6, 6.8, and 7.4. Freeze-dried equimolar solutions of glucose and glycine were heated either dry or after equilibration to approximately 13% moisture at 180 degrees C in a reaction-tube system designed to mimic the heating profile in an extruder. Volatile compounds were isolated onto Tenax and analyzed by gas chromatography-mass spectrometry. For the extrudates, total yields of volatiles increased with decreasing pH at 180 degrees C, reached a maximum at pH 6.8 at 150 degrees C, and increased with increasing pH at 120 degrees C. Amounts increased with temperature at all pH values. Pyrazines were the most abundant class for all sets of conditions (54-79% of total volatiles). Pyrroles, ketones, furans, oxazoles, and pyridines were also identified. Yields of volatiles from the reaction-tube samples increased by >60% in the moist system. Levels of individual classes also increased in the presence of moisture, except pyrazines, which decreased approximately 3.5-fold. Twenty-one of the compounds were common to the reaction-tube samples and the extrudates.

[Effects of Organic and Inorganic Slow-Release Compound Fertilizer on Different Soils Microbial Community Structure].

PubMed

Wang, Fei; Yuan, Ting; Gu, Shou-kuan; Wang, Zheng-yin

2015-04-01

As a new style fertilizer, slow-control release fertilizer had been an important subject in recent years, but few researches were about soil microbial community structure diversity. Phospholipid fatty acid method was used to determined the microbial community structure diversity of acid soil and slight alkaline soil applied with slow-release compound fertilizer (SRF), chemical fertilizer (CF) and common compound fertilizer (CCF) at the 10th, 30th, 60th and 90th day under the constant temperature incubation condition. Results indicated that various bacteria (i. e 13:0, i14:0,14:0, i15:0, a15:0, i16:0, 16:12OH, 16:1w5c,16:0, i17:0, a17:0, cy17:0, 17:02OH, i18:0, 18:0 and cy19:0w8c), two actinomycetes (10Me17:0 and 10Me18:0) and only one fungus (18:1 w9c) were detected in two soils after applying slow-release compound fertilizer and other fertilizers during the whole incubation period. SRF could significantly increase the fungi PLFA content by 8.3% and 6.8% at the early stage (the 10th day and 30th day) compared with CF, as well as significantly increase by 22.7% and 17.1% at the late stage (the 60th day and 90th day) compared with CCF in acid soil. SRF significantly increased bacteria, fungi and gram positive bacteria compared with CF and CCF in incubation period (except at the 30th day) in slight alkaline soil. SRF could significantly improve the ratio of normal saturated fatty acid and monounsaturated fatty acid at the 30th day and 90th days in acid soil compared with no fertilizer (CK), CF and CCF, while as to slight alkaline soil, SRF was significantly greater than that of CK, CF and CCF only at the 60th day. SRF could significantly decrease the ratio of iso PLFA and anteiso PLFA in acid soil (in 30-90 days) and slight alkaline soil (in 10-60 days). For two soils PLFA varieties, contents and ratios of microbial community, slow-release compound fertilizer increased soil microbial PLFA varieties and contents, and decreased the influence to microbial survival environment, especially for the acid soil. Through the research of slow-release compound fertilizer on soil microbial community structure diversity, it could provide a scientific basis for widely application of slow-release compound fertilizer in agricultural production.

Nucleosides and nucleotides. 192. Toward the total synthesis of cyclic ADP-carbocyclic-ribose. Formation of the intramolecular pyrophosphate linkage by a conformation-restriction strategy in a syn-form using a halogen substitution at the 8-position of the adenine ring.

PubMed

Sumita, Y; Shirato, M; Ueno, Y; Matsuda, A; Shuto, S

2000-01-01

The synthesis of cyclic ADP-carbocyclic-ribose (2), as a stable mimic for cyclic ADP-ribose, was investigated. Construction of the 18-membered backbone structure was successfully achieved by condensation of the two phosphate groups of 19, possibly due to restriction of the conformation of the substrate in a syn-form using an 8-chloro substituent at the adenine moiety. SN2 reactions between an optically active carbocyclic unit 8, which was constructed by a previously developed method, and 8-bromo-N6-trichloroacetyl-2',3'-O-isopropylideneadenosine 9c gave N-1-carbocyclic derivative, which was deprotected to give 5'-5"-diol derivatives 18. When 18 was treated with POCl3 in PO(OEt)3, the bromo group at the 8-position was replaced to give N-1-carbocyclic-8-chloroadenosine 5',5"-diphosphate derivative 19 in 43% yield. Treatment of 19 with 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride gave the desired intramolecular condensation product 20 in 10% yield. This is the first chemical construction of the 18-membered backbone structure containing an intramolecular pyrophosphate linkage of a cADPR-related compound with an adenine base.

[Chemical constituents of the roots of Vaccinium bracteatum].

PubMed

Lv, Xiao-Lan; Mai, Xi; Guo, Hui; Lai, Xiao-Ping

2012-06-01

To study the chemical constituents of the roots of Vaccinium bracteatum. The constituents were separated and purified with chromatographic methods (including silica gel, Sephadex LH-20 and RP-18 column chromatography), and their structures were determined by spectroscopic methods (including MS, 1H-NMR and 13C-NMR). 10 compounds were isolated from the roots of Vaccinium bracteatu and were elucidated as chlorogenic acid (1), pinoresinol (2), ferulic acid (3), kaempferol (4), trans-caffeic acid (5), beta-sitosterol (6), quercetin (7), oleanolic acid (8), apigenin (9) and luteolin (10). Compounds 1 -3 are obtained from this plant for the first time.

Methods of analysis by the U.S. Geological Survey National Water Quality Laboratory; determination of organophosphate pesticides in filtered water by gas chromatography with flame photometric detection

USGS Publications Warehouse

Jha, Virendra K.; Wydoski, Duane S.

2002-01-01

A method for the isolation of 20 parent organophosphate pesticides and 5 pesticide degradates from filtered natural-water samples is described. Seven of these compounds are reported permanently with an estimated concentration because of performance issues. Water samples are filtered to remove suspended particulate matter, and then 1 liter of filtrate is pumped through disposable solid-phase extraction columns that contain octadecyl-bonded porous silica to extract the compounds. The C-18 columns are dried with nitrogen gas, and method compounds are eluted from the columns with ethyl acetate. The extract is analyzed by dual capillary-column gas chromatography with flame photometric detection. Single-operator method detection limits in all three water-matrix samples ranged from 0.004 to 0.012 microgram per liter. Method performance was validated by spiking all compounds into three different matrices at three different concentrations. Eight replicates were analyzed at each concentration level in each matrix. Mean recoveries of method compounds spiked in surface-water samples ranged from 39 to 149 percent and those in ground-water samples ranged from 40 to 124 percent for all pesticides except dimethoate. Mean recoveries of method compounds spiked in reagent-water samples ranged from 41 to 119 percent for all pesticides except dimethoate. Dimethoate exhibited reduced recoveries (mean of 43 percent in low- and medium-concentration level spiked samples and 20 percent in high-concentration level spiked samples) in all matrices because of incomplete collection on the C-18 column. As a result, concen-trations of dimethoate and six other compounds (based on performance issues) in samples are reported in this method with an estimated remark code.

Thermodynamic parameters of phase transitions of perfluoro-N-(4-methylcyclohexyl)piperidine

NASA Astrophysics Data System (ADS)

Druzhinina, A. I.; Efimova, A. A.; Varushchenko, R. M.; Chelovskaya, N. V.

2007-12-01

The heat capacity of perfluoro-N-(4-methylcyclohexyl)piperidine (PMCP) was measured by low-temperature adiabatic calorimetry. The purity of the substance ( N 1 = 99.66 mol %), triple point temperature ( T tp = 293.26 K), and enthalpy of fusion (Δfus H {m/°} = 8.32 kJ/mol) were determined. The enthalpy of vaporization was measured by calorimetry at 298.15 K (Δvap H {m/°}(298.15 K) = 56.56 kJ/mol). The temperature dependence of the saturated vapor pressure of PMCP over the pressure range 6.2-101.6 kPa was determined by comparative ebulliometry. The normal boiling point ( T n.b. = 460.74 K), ehthalpies of vaporization (at various temperatures), and critical parameters of PMCP were calculated. The calculated and experimental values of Δvap H {m/°}(298.15 K) agree to within measurement errors, which proves the reliability of these values and pT parameters used in calculations.

Identification of terpenoids from Rubus corchorifolius L. f. leaves and their anti-proliferative effects on human cancer cells.

PubMed

Chen, Xuexiang; Gao, Zili; Song, Mingyue; Ouyang, Wen; Wu, Xian; Chen, Yunjiao; Zhou, Liping; William, Dixon; Cai, Xiaokun; Cao, Yong; Zhou, Shuangde; Tang, Zhonghai; Xiao, Hang

2017-03-22

The leaves of Rubus corchorifolius L. f. have been consumed as a herbal tea for a long time. In this study, two novel (1 and 5) and four known (2, 3, 4 and 6) terpenoids were isolated from the leaves of Rubus corchorifolius L. f. Structural analysis was performed using various spectroscopic methods ( 1 H NMR, 13 C NMR and MS) to identify the following six compounds: (16α)-16,17,18-trihydroxy-ent-kauran-18-O-β-d-glucoside (1), ent-16β,17-dialkyl-3-oxygen-kaurane (2), ent-kaurane-3α,16β,17-triol (3), ent-kaurane(5R,8S,9R,10R,13R,16R)-2-one-16α,17-diol (4), (16R)-16β,17,19-trihydroxy-ent-kaur-3-one (5) and ent-16α,17-dihydroxy-kauran-19-oic-acid (6). These compounds showed different inhibitory effects on various human cancer cells. Compounds 3 and 6 exhibited stronger inhibitory effects on human colon cancer HCT116 cells than the other 4 compounds. Flow cytometry analysis demonstrated that both compounds 3 and 6 caused cell cycle arrest at the G0/G1 phase and induced cellular apoptosis in HCT116 cells. Compounds 3 and 6 modulated the expression levels of key signaling proteins closely related to cell proliferation and apoptosis, i.e., increasing the levels of poly(ADP-ribose) polymerase, p53, and p27, and decreasing the levels of EGFR, cyclin D1, CDK2 and CDK4. Overall, our findings provided insight into the anticancer components of Rubus corchorifolius L. f. leaves, which could facilitate their utilization as functional food ingredients.

Ultrasound-Mediated Tumor Imaging and Nanotherapy using Drug Loaded, Block Copolymer Stabilized Perfluorocarbon Nanoemulsions

PubMed Central

Rapoport, Natalya; Nam, Kweon-Ho; Gupta, Roohi; Gao, Zhongao; Mohan, Praveena; Payne, Allison; Todd, Nick; Liu, Xin; Kim, Taeho; Shea, Jill; Scaife, Courtney; Parker, Dennis L.; Jeong, Eun-Kee; Kennedy, Anne M.

2011-01-01

Perfluorocarbon nanoemulsions can deliver lipophilic therapeutic agents to solid tumors and simultaneously provide for monitoring nanocarrier biodistribution via ultrasonography and/or 19F MRI. In the first generation of block copolymer stabilized perfluorocarbon nanoemulsions, perfluoropentane (PFP) was used as the droplet forming compound. Although manifesting excellent therapeutic and ultrasound imaging properties, PFP nanoemulsions were unstable at storage, difficult to handle, and underwent hard to control phenomenon of irreversible droplet-to-bubble transition upon injection. To solve the above problems, perfluoro-15-crown-5-ether (PFCE) was used as a core forming compound in the second generation of block copolymer stabilized perfluorocarbon nanoemulsions. PFCE nanodroplets manifest both ultrasound and fluorine (19F) MR contrast properties, which allows using multimodal imaging and 19F MR spectroscopy for monitoring nanodroplet pharmacokinetics and biodistribution. In the present paper, acoustic, imaging, and therapeutic properties of unloaded and paclitaxel (PTX) loaded PFCE nanoemulsions are reported. As manifested by the 19F MR spectroscopy, PFCE nanodroplets are long circulating, with about 50% of the injected dose remaining in circulation two hours after the systemic injection. Sonication with 1-MHz therapeutic ultrasound triggered reversible droplet-to-bubble transition in PFCE nanoemulsions. Microbubbles formed by acoustic vaporization of nanodroplets underwent stable cavitation. The nanodroplet size (200 nm to 350 nm depending on a type of the shell and conditions of emulsification) as well as long residence in circulation favored their passive accumulation in tumor tissue that was confirmed by ultrasonography. In the breast and pancreatic cancer animal models, ultrasound-mediated therapy with paclitaxel-loaded PFCE nanoemulsions showed excellent therapeutic properties characterized by tumor regression and suppression of metastasis. Anticipated mechanisms of the observed effects are discussed. PMID:21277919

C18-coated stir bar sorptive extraction combined with high performance liquid chromatography-electrospray tandem mass spectrometry for the analysis of sulfonamides in milk and milk powder.

PubMed

Yu, Chunhe; Hu, Bin

2012-02-15

A simple, rapid, sensitive, inexpensive and less sample consuming method of C(18)-stir bar sorptive extraction (SBSE)-high performance liquid chromatography (HPLC)-tandem mass spectrometry (MS/MS) was proposed for the determination of six sulfonamides in milk and milk powder samples. C(18) silica particles coated stir bar was prepared by adhesion method, and two kinds of adhesive glue, polydimethylsiloxane (PDMS) sol and epoxy glue were tried. It was found that the C(18)-coated stir bar prepared by PDMS sol as adhesive glue is more robust than that prepared by epoxy glue when liquid desorption was employed, in terms of both lifetime and organic solvent tolerance. The preparation of C(18) stir bar was simple with good mechanic strength and the stir bar could be reused for more than 20 times. Granular coating has relatively high specific surface area and is propitious to sorptive extraction based process. Compared to conventional PDMS SBSE coating, C(18) coating shows good affinity to the target polar/weak polar sulfonamides. To achieve optimum SBSE extraction performance, several parameters including extraction and desorption time, ionic strength, sample pH and stirring speed were investigated. The detection limits of the proposed method for six sulfonamides were in the range of 0.9-10.5 μg/L for milk and 2.7-31.5 μg/kg for milk powder. Good linearities were obtained for sulfonamides with the correlation coefficients (R) above 0.9922. Finally, the proposed method was successfully applied to the determination of sulfonamides in milk and milk powder samples and satisfied recoveries of spiked target compounds in real samples were obtained. Copyright © 2012 Elsevier B.V. All rights reserved.

Compositions and methods related to serotonin 5-HT1A receptors

DOEpatents

Mukherjee, Jogeshwar; Saigal, Neil

2010-06-08

Contemplated substituted arylpiperazinyl compounds, and most preferably ¹⁸F-Mefway, exhibit desirable in vitro and in vivo binding characteristics to the 5-HT1A receptor. Among other advantageous parameters, contemplated compounds retain high binding affinity, display optimal lipophilicity, and are radiolabeled efficiently with ¹⁸F-fluorine in a single step. Still further, contemplated compounds exhibit high target to non-target ratios in receptor-rich regions both in vitro and in vivo, and selected compounds can be effectively and sensitively displaced by serotonin, thus providing a quantitative tool for measuring 5-HT1A receptors and serotonin concentration changes in the living brain.

Compositions and methods related to serotonin 5-HT1A receptors

DOEpatents

Mukherjee, Jogeshwar [Irvine, CA; Saigal, Neil [Fresno, CA; Saigal, legal representative, Harsh

2012-09-25

Contemplated substituted arylpiperazinyl compounds, and most preferably .sup.18F-Mefway, exhibit desirable in vitro and in vivo binding characteristics to the 5-HT1A receptor. Among other advantageous parameters, contemplated compounds retain high binding affinity, display optimal lipophilicity, and are radiolabeled efficiently with .sup.18F-fluorine in a single step. Still further, contemplated compounds exhibit high target to non-target ratios in receptor-rich regions both in vitro and in vivo, and selected compounds can be effectively and sensitively displaced by serotonin, thus providing a quantitative tool for measuring 5-HT1A receptors and serotonin concentration changes in the living brain.

Compositions and methods related to serotonin 5-HT1A receptors

DOEpatents

Mukherjee, Jogeshwar; Saigal, Neil; Saigal, legal representative, Harsh

2012-09-25

Contemplated substituted arylpiperazinyl compounds, and most preferably ¹⁸F-Mefway, exhibit desirable in vitro and in vivo binding characteristics to the 5-HT1A receptor. Among other advantageous parameters, contemplated compounds retain high binding affinity, display optimal lipophilicity, and are radiolabeled efficiently with ¹⁸F-fluorine in a single step. Still further, contemplated compounds exhibit high target to non-target ratios in receptor-rich regions both in vitro and in vivo, and selected compounds can be effectively and sensitively displaced by serotonin, thus providing a quantitative tool for measuring 5-HT1A receptors and serotonin concentration changes in the living brain.

Phytotoxic flavonoids from roots of Stellera chamaejasme L. (Thymelaeaceae).

PubMed

Yan, Zhiqiang; Guo, Hongru; Yang, Jiayue; Liu, Quan; Jin, Hui; Xu, Rui; Cui, Haiyan; Qin, Bo

2014-10-01

Allelopathy, the negative effect on plants of chemicals released to the surroundings by a neighboring plant, is an important factor which contributes to the spread of some weeds in plant communities. In this field, Stellera chamaejasme L. (Thymelaeaceae) is one of the most toxic and ecologically-threatening weeds in some of the grasslands of north and west China. Bioassay-guided fractionation of root extracts of this plant led to the isolation of eight flavonoids 1-8, whose structures were elucidated by spectroscopic analysis. All compounds obtained, except 7-methoxylneochaejasmin A (4) and (+)-epiafzelechin (5), showed strong phytotoxic activity against Arabidopsis thaliana seedlings. Seedling growth was reduced by neochamaejasmin B (1), mesoneochamaejasmin A (2), chamaejasmenin C (3), genkwanol A (6), daphnodorin B (7) and dihydrodaphnodorin B (8) with IC50 values of 6.9, 12.1, 43.2, 74.8, 7.1 and 27.3μg/mL, respectively, and all of these compounds disrupted root development. Endogenous auxin levels at the root tips of the A. thaliana DR5::GUS transgenic line were largely reduced by compounds 1, 2 and 6-8, and were increased by compound 4. Moreover, the inhibition rate of A. thaliana auxin transport mutants pin2 and aux1-7 by compounds 1-8 were all lower than the wild type (Col-0). The influence of these compounds on endogenous auxin distribution is thus proposed as a critical factor for the phytotoxic effect. Compounds 1, 2, 4 and 8 were found in soils associated with S. chamaejasme, and these flavonoids also showed phytotoxicity to Clinelymus nutans L., an associated weed of S. chamaejasme. These results indicated that some phytotoxic compounds from roots of S. chamaejasme may be involved in the potential allelopathic behavior of this widespread weed. Copyright © 2014 Elsevier Ltd. All rights reserved.

Discovery of 2-aminothiazolyl berberine derivatives as effectively antibacterial agents toward clinically drug-resistant Gram-negative Acinetobacter baumanii.

PubMed

Gao, Wei-Wei; Gopala, Lavanya; Bheemanaboina, Rammohan R Yadav; Zhang, Guo-Biao; Li, Shuo; Zhou, Cheng-He

2018-02-25

Aminothiazolyl berberine derivatives as potentially antimicrobial agents were designed and synthesized in an effort to overcome drug resistance. The antimicrobial assay revealed that some target compounds exhibited significantly inhibitory efficiencies toward bacteria and fungi including drug-resistant pathogens, and the aminothiazole and Schiff base moieties were helpful structural fragments for aqueous solubility and antibacterial activity. Especially, aminothiazolyl 9-hexyl berberine 9c and 2,4-dichlorobenzyl derivative 18a exhibited good activities (MIC = 2 nmol/mL) against clinically drug-resistant Gram-negative Acinetobacter baumanii with low cytotoxicity to hepatocyte LO2 cells, rapidly bactericidal effects and quite slow development of bacterial resistance toward A. baumanii. Molecular modeling indicated that compounds 9c and 18a could bind with GLY-102, ARG-136 and/or ALA-100 residues of DNA gyrase through hydrogen bonds. It was found that compounds 9c and 18a were able to disturb the drug-resistant A. baumanii membrane effectively, and molecule 9c could not only intercalate but also cleave bacterial DNA isolated from resistant A. baumanii, which might be the preliminary antibacterial action mechanism of inhibiting the growth of A. baumanii strain. In particular, the combination use of compound 9c with norfloxacin could enhance the antibacterial activity, broaden antibacterial spectrum and overcome the drug resistance. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

[Chemical constituents contained in seeds of Notopterygium franchetii].

PubMed

Zhang, Yanxia; Jiang, Shunyuan; Xu, Kaijie; Shi, Haili; Zhou, Yi; Deng, Wenlong; Ding, Lisheng; Peng, Shulin

2012-04-01

To study the chemical constituents from the seeds of Notopterygium franchetii. Ethanol extracts of seeds N. franchetii were separated and purified by such methods as normal and reversed phase column chromatographies and thin-layer chromatography and structurally elucidated by MS and NMR evidences. Twenty nine compounds were separated, they were isoimperatorin (1), [3-sitosterol (2), phellopterin (3), bergapten (4), N-tetra, hexa, octacosanoylanthranilic acid (5-7), daucosterol (8), oxypeucedanin hydrate (9), umbelliferone (10), demethylfuropinnarin (11), (2S, 3S, 4R, 8E)-2-[(2'R)- 2'-hydroxydoco, trico, tetraco, entaco, hexaco sanosylamino] -octadecene-1, 3, 4-triol (12-16), (-)-oxypeucedanin (17), diosmetin (18), bergaptol-O-beta-D-glucopyranoside (19), nodakenin (20), 1'-O-beta-D-glucopyranosyl-(2R, 3S)-3-hydroxynodakenetin (21), uracil (22), decuroside V (23), 8-O-beta-D-glucopyranosyl-5-hydroxypsoralen (24), 8-O-beta-D-glucopyranosyl-5-methoxylpsoralen (25), diosmin (26), alaschanioside C (27), kynurenic acid (28) and mannitol (29). All of these compounds were separated from the seeds of N. franchetii for the first time. Of them, 18, 22, 26 and 29 were firstly obtained from genus Notopterygium.

Infant exposure of perfluorinated compounds: levels in breast milk and commercial baby food.

PubMed

Llorca, Marta; Farré, Marinella; Picó, Yolanda; Teijón, Marisa Lopez; Alvarez, Juan G; Barceló, Damià

2010-08-01

In this study, an analytical method to determine six perfluorinated compounds (PFCs) based on alkaline digestion and solid phase extraction (SPE) followed by liquid chromatography-quadrupole-linear ion trap mass spectrometry (LC-QqLIT-MS) was validated for the analysis of human breast milk, milk infant formulas and cereals baby food. The average recoveries of the different matrices were in general higher than 70% with a relative standard deviation (RSD) lower than 21% and method limits of detection (MLOD) ranging from 1.2 to 362 ng/L for the different compounds and matrices. The method was applied to investigate the occurrence of PFCs in 20 samples of human breast milk, and 5 samples of infant formulas and cereal baby food (3 brands of commercial milk infant formulas and 2 brands of cereals baby food). Breast milk samples were collected in 2008 from donors living in Barcelona city (Spain) on the 40 days postpartum. Perfluorooctanesulfonate (PFOS) and perfluoro-7-methyloctanoic acid (i,p-PFNA) were predominant being present in the 95% of breast milk samples. Perfluorooctanoic acid (PFOA) was quantified in 8 of the 20 breast milk samples at concentrations in the range of 21-907 ng/L. Commercial formulas and food were purchased also in 2009 from a retail store. The six PFCs were detected in all brands of milk infant formulas and cereals baby food analyzed, being perfluorodecanoic acid (PFDA), PFOS, PFOA and i,p-PFNA the compounds detected in higher concentrations (up to 1289 ng/kg). PFCs presence can be associated to possible migration from packaging and containers during production processes. Finally, based on estimated body weight and newborn intake, PFOS and PFOA daily intakes and risk indexes (RI) were estimated for the firsts 6 month of life. We found that ingestion rates of PFOS and PFOA, with exception of one breast milk sample did not exceed the tolerable daily intake (TDI) recommended by the EFSA. However, more research is needed in order to assess possible risk associated to PFCs contamination during early stages of life. Copyright 2010 Elsevier Ltd. All rights reserved.

Discovery of gigantic molecular nanostructures using a flow reaction array as a search engine

PubMed Central

Zang, Hong-Ying; de la Oliva, Andreu Ruiz; Miras, Haralampos N.; Long, De-Liang; McBurney, Roy T.; Cronin, Leroy

2014-01-01

The discovery of gigantic molecular nanostructures like coordination and polyoxometalate clusters is extremely time-consuming since a vast combinatorial space needs to be searched, and even a systematic and exhaustive exploration of the available synthetic parameters relies on a great deal of serendipity. Here we present a synthetic methodology that combines a flow reaction array and algorithmic control to give a chemical ‘real-space’ search engine leading to the discovery and isolation of a range of new molecular nanoclusters based on [Mo2O2S2]2+-based building blocks with either fourfold (C4) or fivefold (C5) symmetry templates and linkers. This engine leads us to isolate six new nanoscale cluster compounds: 1, {Mo10(C5)}; 2, {Mo14(C4)4(C5)2}; 3, {Mo60(C4)10}; 4, {Mo48(C4)6}; 5, {Mo34(C4)4}; 6, {Mo18(C4)9}; in only 200 automated experiments from a parameter space spanning ~5 million possible combinations. PMID:24770632

Development and Validation of a Stability-indicating Reversed-phase UPLC-UV Method for the Assay of Imidacloprid and Estimation of its Related Compounds.

PubMed

Tian, Jingzhi; Rustum, Abu

2018-02-01

Imidacloprid is used as an active pharmaceutical ingredient (API) in veterinary drugs to control fleas and ticks for dogs and cats. Here we are reporting for the first time a validated stability-indicating reversed-phase UPLC-UV method for the assay of imidacloprid and estimation of its related compounds. The stability-indicating capability of this method has been demonstrated by a forced degradation study. All related compounds including processing impurities, imidacloprid API and degradates from stressed samples were well separated from each other. Structures of major degradates from forced degradation study were elucidated through UPLC-MS/MS and key degradation pathways were proposed from the proposed chemical structures of major degradates. The UPLC-UV method is carried out using an HSS T3 column (C18, 2.1 × 30 mm, 1.8 μm particle size) maintained at 30°C with mobile phase A (0.05% v/v of phosphoric acid in water) and mobile phase B (methanol/acetonitrile 75/25 v/v). Analytes are separated by a gradient elution and detected at 270 nm. The UPLC method is green and fast with only 6.5 min run time and about 3.5 ml mobile phase consumption for each sample analysis. The UPLC-UV method was validated according to ICH guidelines. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Gallium Arsenide and Related Compounds, 1986.

DTIC Science & Technology

1986-01-01

AFMRI.1U8 d7 -18 6o 60AM F PERORMING ORGANIZATIN ,1b OFICE SYMBOL. 7a. NAME OF MONITORING ORGANIZATION Of appkiie) Unvriyof Illinois AFOSRINE 6C...effect is shown in the log I vs. V characteristics in figure 5. Both devices exhibit good logarithmic behaviour , but it is clear that the ideality of the...effects at the surface. As also shown in Fig. 5, a 200 nm thick n-doped ion implanted and activated layer shows a "mixed" behaviour , namely a linear

Sterols from Sargassum oligocystum, a brown algae from the Persian Gulf, and their bioactivity.

PubMed

Permeh, Parisa; Saeidnia, Soodabeh; Mashinchian-Moradi, Ali; Gohari, Ahmad R

2012-01-01

Sargassum oligocystum (Heterokontophyta) is one of the most abundant algae distributed in the Persian Gulf. In this study, the cytotoxic effects of this algae on brine shrimp larvae were evaluated and the main sterols of the algae identified. Separation and purification of the compounds was carried out using silica gel column chromatography and HPLC to obtain eight pure compounds, 1-8. Structural elucidation of the constituents was based on the data obtained from (1)H-NMR, (13)C-NMR, HSQC, HMBC, DEPT and EI-MS. The compounds separated from S. oligocystum were identified as 22-dehydrocholesterol (1), cholesterol (2), fucosterol (3), 29-hydroperoxystigmasta-5,24(28)-dien-3β-ol (4), 24-hydroperoxy-24-vinylcholesterol (5), a mixture of 24(S)-hydroxy-24-vinylcholesterol (6) and 24(R)-hydroxy-24-vinylcholesterol (7), and ostreasterol (8) based on their spectral data and from comparison with those previously reported in the literature.

2,2′,5,5′-Tetra­methyl-1,1′-(hexane-1,6-di­yl)di-1H-pyrrole

PubMed Central

Santos, Ana C.; Ramos Silva, Manuela; Monsanto, Paula V.; Matos Beja, Ana; Sobral, Abilio J. F. N.

2009-01-01

The mol­ecule of the title compound, C18H28N2, composed of two 2,5-dimethyl­pyrrole groups linked by a hexane chain, lies across a crystallographic inversion centre. The mean plane of the pyrrole ring is almost perpendicular to the mean plane of the central chain, making a dihedral angle of 89.09 (8)°. The crystal structure is stabilized by inter­molecular C—H⋯π inter­actions. PMID:21582868

BI- and tricyclic diterpenoids from Halimium viscosum.

PubMed

Rodilla, J M; De Mendonça, D I; Ismael, M I; Figueiredo, J A; Silva, M L; Lopes, E

2001-01-01

The study of the acid and neutral parts of the n-hexane extract of Halimium viscosum (S. João da Pesqueira, Portugal) has led to the isolation of various known diterpenoids with the ent-halimane skeleton. Five new compounds have now been isolated, one with the ent-halimane skeleton, and four with the valparane skeleton, two of them with the valparane skeleton degraded. The structures of these compounds, determined by spectroscopic methods using 2D experiments (1H-13C, HMQC and HMBC), were dimethyl 1(10)-halimen-15,18-dioate, dimethyl 3,19-dinor-15-valparen-2,4-dioate, methyl 16-nor-2,3-secovalpara-3,15-dioxo-2-oate, 1,3,5,1 5-valparatetraene and 3R-4alpha-methoxy-15-valparen-2-one.

Synthesis of 4,19-disubstituted derivatives of DOC. Radioreceptor assay of some corticosteroid derivatives in human mononuclear leukocytes.

PubMed

Harnik, M; Kashman, Y; Cojocaru, M; Bauer, H; Laux, M; Lewicka, S; Vecsei, P

1990-10-01

Several new 4,19-substituted steroids and previously synthesized corticosteroids were assayed for affinity to type 1 receptors in human mononuclear leukocytes. 11 beta,19-epoxy-4,21-dihydroxypregn-4-ene-3,20-dione (2) was hydrogenated with Pd-C to yield a mixture of all four dihydro derivatives 5, accompanied by 4,21-diacetoxy-11 beta,19-epoxy-3-hydroxypregnan-20-one (6) and 21-acetoxy-11 beta,19-epoxy-4-hydroxypregnane-3,20-dione (7). With hot acetic + p-toluenesulfonic acid 5 underwent rearrangement to 21-acetoxy-11 beta,19-epoxypregn-5-ene-4,20-dione (8) Pd-C hydrogenation of 3,21-diacetoxy-5 beta,19-cyclopregna-2,9(11)-diene-4,20-dione (10) gave 3,21-diacetoxy-5 beta,19-cyclopregn-5-ene-4,20-dione (11) and the 9,11-dihydro derivative of the latter. Treatment of 10 with warm HCl furnished 19-chloro-4,21-dihydroxypregna-4,9(11)-diene-3,20-dione (13). Pd-C hydrogenation of its diacetate 14 afforded the 4,5-dihydro derivative 18, 19-chloro-21-acetoxypregn-9(11)-en-20-one (15), its 4-acetoxy derivative 16 and the 3,4-diacetoxy derivative 17. When tested in a radioreceptor assay in human mononuclear leukocytes the synthesized compounds showed only low relative binding affinities (RBA) to type 1 receptor, the highest being 0.72% for 13 (aldosterone = 100%). For comparison, other RBA in this system were: 19-noraldosterone, 20%; 18-deoxyaldosterone, 5.8%; 18-deoxy-19-noraldosterone, 4.7%; 18,21-anhydroaldosterone, 0.37%; 17-isoaldosterone, 7.6% and apoaldosterone, 4.3%

Isolation, purification, and characterization of antimicrobial compound 6-[1,2-dimethyl-6-(2-methyl-allyloxy)-hexyl]-3-(2-methoxy-phenyl)-chromen-4-one from Penicillium sp. HT-28.

PubMed

Kaur, Harpreet; Arora, Daljit Singh; Sharma, Vishal

2014-08-01

A fungal culture (Penicillium sp., HT-28), isolated from soil has been evaluated for its bioactivity, which showed broad spectrum antimicrobial activity and was effective against methicillin-resistant Staphylococcus aureus (MRSA) also. Statistical optimization of the medium by response surface methodology (RSM) enhanced the antimicrobial activity up to 1.8-fold. Column chromatography was used to isolate the active compound (A), which was characterized to be 6-[1,2-dimethyl-6-(2-methyl-allyloxy)-hexyl]-3-(2-methoxy-phenyl)-chromen-4-one by various spectroscopic techniques such as infrared (IR), (1)H and (13)C nuclear magnetic resonance (NMR) spectra, and mass spectroscopy. Minimum inhibitory concentration (MIC) of the active compound (A) ranged from 0.5 to 15 μg/mL. Viable cell count studies of the active compound (A) showed S. aureus, Escherichia coli, Staphylococcus epidermidis, and Salmonella typhimurium 1 to be the most sensitive. The compound retained its bioactivity after treating it at 100 °C for 1 h. Furthermore, the compound (A) when tested for its biosafety was found neither to be cytotoxic nor mutagenic. The study demonstrated that an apparently novel compound isolated from Penicillium sp. (HT-28) seems to be a stable and potent antimicrobial.

Impact of molecular imaging on the diagnostic process in a memory clinic.

PubMed

Ossenkoppele, Rik; Prins, Niels D; Pijnenburg, Yolande A L; Lemstra, Afina W; van der Flier, Wiesje M; Adriaanse, Sofie F; Windhorst, Albert D; Handels, Ron L H; Wolfs, Claire A G; Aalten, Pauline; Verhey, Frans R J; Verbeek, Marcel M; van Buchem, Mark A; Hoekstra, Otto S; Lammertsma, Adriaan A; Scheltens, Philip; van Berckel, Bart N M

2013-07-01

[(11)C]Pittsburgh compound B ([(11)C]PIB) and [(18)F]-2-fluoro-2-deoxy-D-glucose ([(18)F]FDG) PET measure fibrillar amyloid-β load and glucose metabolism, respectively. We evaluated the impact of these tracers on the diagnostic process in a memory clinic population. One hundred fifty-four patients underwent paired dynamic [(11)C]PIB and static [(18)F]FDG PET scans shortly after completing a standard dementia screening. Two-year clinical follow-up data were available for 39 patients. Parametric PET images were assessed visually and results were reported to the neurologists responsible for the initial diagnosis. Outcome measures were (change in) clinical diagnosis and confidence in that diagnosis before and after disclosing PET results. [(11)C]PIB scans were positive in 40 of 66 (61%) patients with a clinical diagnosis of Alzheimer's disease (AD), 5 of 18 (28%) patients with frontotemporal dementia (FTD), 4 of 5 (80%) patients with Lewy body dementia, and 3 of 10 (30%) patients with other dementias. [(18)F]FDG uptake patterns matched the clinical diagnosis in 38 of 66 (58%) of AD patients, and in 6 of 18 (33%) FTD patients. PET results led to a change in diagnosis in 35 (23%) patients. This only occurred when prior diagnostic certainty was <90%. Diagnostic confidence increased from 71 ± 17% before to 87 ± 16% after PET (p < .001). Two-year clinical follow-up (n = 39) showed that [(11)C]PIB and [(18)F]FDG predicted progression to AD for patients with mild cognitive impairment, and that the diagnosis of dementia established after PET remained unchanged in 96% of patients. In a memory clinic setting, combined [(11)C]PIB and [(18)F]FDG PET are of additional value on top of the standard diagnostic work-up, especially when prior diagnostic confidence is low. Copyright © 2013 The Alzheimer's Association. Published by Elsevier Inc. All rights reserved.

(Cryptand-222)potassium(+) (hydrogensulfido)[5,10,15,20-tetra-kis(2-pival-amido-phen-yl)porphyrinato]ferrate(II).

PubMed

Dhifet, Mondher; Belkhiria, Mohamed Salah; Daran, Jean-Claude; Nasri, Habib

2009-07-22

As part of a systematic investigation for a number of Fe(II) porphyrin complexes used as biomimetic models for cytochrome P450, crystals of the title compound, [K(C(18)H(36)N(2)O(6))][Fe(II)(C(64)H(64)N(8)O(4))(HS)], were prepared. The compound exhibits a non-planar conformation with major ruffling and saddling distortions. The average equatorial iron-pyrrole N atom [Fe-N(p) = 2.102 (2) Å] bond length and the distance between the Fe(II) atom and the 24-atom core of the porphyrin ring (Fe-P(C)= 0.558 Å) are typical for high-spin iron(II) penta-coordinate porphyrinates. One of the tert-butyl groups in the structure is disordered over two sets with occupancies of 0.84 and 0.16.

Fast Gas Chromatography with Tandem Mass Spectrometry Analysis of Selected Persistent Organic Pollutants and Organophosphorus and Synthetic Pyrethroid Pesticides in Indian Prawn (Fenneropenaeus indicus) in Compliance with the EU-MRLs.

PubMed

Sawant, Durvesh; Kelkar, Jitendra; Rasam, Pratap; Datar, Ajit; Hase, Prashant; Handique, Dheeraj; Bhone, Ankush; Chiplunkar, Sanket; Hate, Manish

2017-05-01

A fast GC with tandem MS method was developed and validated for multiresidue determination of 95 chemical contaminants (24 synthetic pyrethroids, 17 organochlorines, 17 organophosphorus compounds, 18 polycyclic aromatic hydrocarbons, and 19 polychlorinated biphenyls) in Indian prawns (Fenneropenaeus indicus) as per the European Union maximum residual limit requirements. Chromatographic separation and MS determination were achieved within a short run time of 18 min, without compromising sensitivity and specificity. Our findings revealed a 2.5× reduction in the run time compared with conventional GC methods. Sample preparation involved a QuEChERS-based extraction of 10 g sample with 10 mL acidified acetonitrile (1% acetic acid) and phase separation with 6 g anhydrous magnesium sulfate and 1.5 g sodium acetate. The extract was cleaned in two steps, first by dispersive cleanup with primary secondary amine and then by C18 SPE cartridge. The regression coefficients of linearity (r2) for the concentration range of 5-50 ng/mL were >0.99 for all the compounds. Recoveries at 5 and 10 ng/g levels were within the acceptable range of 70-120%. The repeatability (RSDr) and within-laboratory reproducibility (RSDwR) precisions were ≤20%. The method was successfully applied for analysis of the real world samples for incurred residues.

Electronic structure and nature of the ground state of the mixed-valence binuclear tetra(mu-1,8-naphthyridine-N,N')-bis(halogenonickel) tetraphenylborate complexes: experimental and DFT characterization.

PubMed

Bencini, Alessandro; Berti, Elisabetta; Caneschi, Andrea; Gatteschi, Dante; Giannasi, Elisa; Invernizzi, Ivana

2002-08-16

The ground state electronic structure of the mixed-valence systems [Ni(2)(napy)(4)X(2)](BPh(4)) (napy=1,8-naphthyridine; X=Cl, Br, I) was studied with combined experimental (X-ray diffraction, temperature dependence of the magnetic susceptibility, and high-field EPR spectroscopy) and theoretical (DFT) methods. The zero-field splitting (zfs) ground S=3/2 spin state is axial with /D/ approximately 3 cm(-1). The iodide derivative was found to be isostructural with the previously reported bromide complex, but not isomorphous. The compound crystallizes in the monoclinic system, space group P2(1)/n, with a=17.240(5), b=26.200(5), c=11.340(5) A, beta=101.320(5) degrees. DFT calculations were performed on the S=3/2 state to characterize the ground state potential energy surface as a function of the nuclear displacements. The molecules can thus be classified as Class III mixed-valence compounds with a computed delocalization parameter, B=3716, 3583, and 3261 cm(-1) for the Cl, Br, and I derivatives, respectively.

(18)F-Fluoroglucosylation of peptides, exemplified on cyclo(RGDfK).

PubMed

Hultsch, Christina; Schottelius, Margret; Auernheimer, Jörg; Alke, Andrea; Wester, Hans-Jürgen

2009-09-01

Oxime formation between an aminooxy-functionalized peptide and an (18)F-labelled aldehyde has recently been introduced as a powerful method for the rapid one-step chemoselective synthesis of radiofluorinated peptides. Here, the potential of using routinely produced and thus readily available [(18)F]fluorodeoxyglucose ([(18)F]FDG) as the aldehydic prosthetic group was investigated using an aminooxyacetyl-conjugated cyclic RGD peptide (cyclo(RGDfK(Aoa-(Boc)) as a model peptide. The use of [(18)F]FDG from routine production ([(18)F]FDGTUM) containing an excess of D: -glucose did not allow the radiosynthesis of [(18)F]FDG-RGD in activities >37 MBq in reasonable yield, rendering the direct use of clinical grade [(18)F]FDG for the routine clinical synthesis of (18)F-labelled peptides impossible. Using no-carrier-added (n.c.a.) [(18)F]FDG obtained via HPLC separation of [(18)F]FDGTUM from excess glucose, however, afforded [(18)F]FDG-RGD in yields of 56-93% (decay corrected) and activities up to 37 MBq. Suitable reaction conditions were 20 min at 120 degrees C and pH 2.5, and a peptide concentration of 5 mM. In a preliminary in vivo biodistribution study in M21 melanoma-bearing nude mice, [(18)F]FDG-RGD showed increased tumour accumulation compared to the "gold standard" [(18)F]galacto-RGD (2.18 vs 1.49 %iD/g, respectively, at 120 min after injection), but also slightly increased uptake in non-target organs, leading to comparable tumour/organ ratios for both compounds. These data demonstrate that chemoselective (18)F-labelling of aminooxy-functionalized peptides using n.c.a. [(18)F]FDG represents a radiofluorination/glycosylation strategy that allows preparation of (18)F-labelled peptides in high yield with suitable pharmacokinetics. As soon as the necessary n.c.a. preparation of [(18)F]FDG prior to reaction with the Aoa-peptide can be implemented in a fully automated [(18)F]FDG-synthesis, [(18)F]fluoroglucosylation of peptides may represent a promising alternative to currently used chemoselective one-step (18)F-labelling protocols.

Thermally Induced Silane Dehydrocoupling on Silicon Nanostructures (International ed.)

DTIC Science & Technology

2016-07-29

grafted. When performed on a mesopo- rous Si wafer, the perfluoro reagent yields a superhydrophobic surface (contact angle 1518). The bromo-derivative... superhydrophobic behavior, with a water contact angle of 1508 (Figure S13 and S14). As with the octadecylsilane derivative, these surface chemistries were not

[Inhibitory effect of compound cantharides capsule on the proliferation of xenografts of human hepatocellular carcinoma HepG(2)215 in mice].

PubMed

Han, Jian-jun; Yu, Jin-ming; Wu, Hui-yong; Liu, Ji-bing; Song, Bao; Xue, De-wen

2012-11-01

To investigate the inhibitory effect of compound cantharides capsules on the proliferation of xenografts of human hepatocellular carcinoma HepG(2215) in mice and their mechanism of action. One hundred healthy Balb/c mice (5-week old, male:female 1:1) were used in this study. Mouse models of human HepG(2215) hepatocarcinoma were established. The tumor-bearing mice were divided into five groups randomly. The control group A received daily intragastric administration of physiologic saline. The intervention groups B1, B2 and B3 were treated with compound cantharides capsule in a dose of 12.5 mg×kg(-1)×d(-1), 25 mg×kg(-1)×d(-1) and 37.5 mg×kg(-1)×d(-1), respectively, for 10 consecutive days. The group C had intraperitoneal injection of cyclophosphamide (25 mg×kg(-1)×d(-1)) for 10 consecutive days. The mice were sacrificed after the completion of administration. The tumors were taken out, the tumor volume was measured, the inhibitory rate of body weight was calculated, and the serum AFP concentration and the level of HBV DNA were determined. The survival of each group mice was analyzed. The levels of mRNA expression of apoptosis-related genes were assayed by quantitative RT-PCR. Apoptosis in the tumor cells was assayed with TUNEL staining. Flow cytometry was used to detect the levels of CD3(+), CD19(+), CD4(+) and CD8(+), and microvessel density (MVD) of the tumors was assessed by immunohistochemistry. After completion of the treatment, the inhibition rate of tumor growth of the groups B1, B2 and B3 was 29.8%, 38.7% and 48.1%, respectively, and that of the group C was 52.4%, with a significant difference among the groups (P < 0.05). The median survival time of the groups A, B1, B2, B3 and C was (30.0 ± 3.2) days, (49.0 ± 5.1) days, (50.0 ± 5.2) days, (57.5 ± 6.5) days and (49.0 ± 4.7) days, respectively. The median survival time of the group B3 was significantly longer than that of other groups (P < 0.05). The serum AFP level in the groups A, B1, B2, B3 and C was (492.7 ± 48.5) ng/ml, (281.2 ± 25.6) ng/ml, (194.3 ± 18.7) ng/ml, (170.1 ± 15.8) ng/ml and (138.7 ± 12.5) ng/ml, respectively, indicating that it was significantly inhibited in the group C. The inhibition rate of HBV DNA replication of the groups B1, B2, B3 and C was (46.0 ± 5.1)%, (65.5 ± 6.9)%, (81.3 ± 7.8)% and (19.5 ± 2.1)%, respectively, showing that compound cantharides capsules inhibited HBV DNA replication in a dose-dependent manner. The apoptosis rate of the groups A, B1, B2, B3 and C was (0.27 ± 0.03)%, (7.18 ± 2.12)%, (9.17 ± 2.42)%, (11.27 ± 3.03)% and (5.44 ± 2.45)%, respectively, and that of the group B3 was significantly higher than that of the groups A, B1, B2 and C (P < 0.05). The expression level of bax mRNA was significantly higher than that of the group C (P < 0.05). The drug could significantly decrease the bcl-2 mRNA expression level, more remarkably along with the increasing dose of cantharides, and it was significantly lower than that in the group C (P < 0.05). The levels of CD4(+), CD8(+), CD3(+) and CD19(+) were significantly higher than that in the groups A and C (P < 0.05). The value of MVD of the group B3 was significantly lower that that of groups A and C (P < 0.05). Compound cantharides capsules may inhibit the replication of HBV DNA in HepG(2215) cells, inducing apoptosis in the tumor cells, enhancing the immune function to inhibit the growth of liver cancer cells in mice, and significantly prolong the median survival time of tumor-bearing mice.

Uptake of pesticides from water by curly waterweed Lagarosiphon major and lesser duckweed Lemna minor.

PubMed

de Carvalho, Renato F; Bromilow, Richard H; Greenwood, Richard

2007-08-01

The uptake of pesticides from water by two aquatic plants, the submersed Lagarosiphon major (Ridley) Moss and the floating duckweed Lemna minor L., was measured over periods of up to 72 h. Twelve non-ionised pesticides and analogues, chosen to span a wide range of physicochemical properties, and one analogue (3,5-D) of the phenoxyacetic acid herbicide 2,4-D were studied. Concentrations of the parent compound were determined in the plants following extraction and separation by chromatography. Quantification was by liquid scintillation counting for the (14)C-labelled compounds and by high-performance liquid chromatography for the four non-radiolabelled commercial pesticides. Uptake for all compound and plant combinations had reached equilibrium by 24 h. Accumulation of compound in the plant could be described well for most non-ionised compounds by equilibration into the aqueous phase in the plant cells together with partitioning onto the plant solids, this latter process becoming dominant in Lagarosiphon for compounds with log K(ow) > 1 and in Lemna for compounds with log K(ow) > 1.8. Lipophilic compounds with log K(ow) > 4 were concentrated more than 100-fold on a fresh-weight basis. However, the uptake of isoproturon and chlorotoluron was up to threefold less than expected from their K(ow) values, and their behaviour was better explained using solvation descriptors. Uptake of the acid 3,5-D was dependent on solution pH, this compound being strongly taken up at lower pH by the process of ion trapping, as previously observed in barley roots. Aquatic vegetation can thus rapidly accumulate pesticides, and could be an important sink especially for lipophilic pesticides reaching well-vegetated waters. Copyright (c) 2007 Society of Chemical Industry

Pulsed current activated synthesis and rapid consolidation of a nanostructured Mg2Al4Si5O18 and its mechanical properties

NASA Astrophysics Data System (ADS)

Shon, In-Jin; Kang, Hyun-Su; Doh, Jung-Mann; Yoon, Jin-Kook

2015-03-01

Nanocrystalline materials have received much attention as advanced engineering materials, with improved mechanical properties. Attention has been directed to the application of nanomaterials, as they possess excellent mechanical properties (high strength, high hardness, excellent ductility and toughness). A singlestep synthesis and consolidation of nanostructured Mg2Al4Si5O18 was achieved by pulsed current heating, using the stoichiometric mixture of MgO, Al2O3 and SiO2 powders. Before sintering, the powder mixture was high-energy ball milled for 10 h. From the milled powder mixture, a highly dense nanostructured Mg2Al4Si5O18 compound could be obtained within one minute, under the simultaneous application of 80 MPa pressure, and a pulsed current. The advantage of this process is that it allows an instant densification to the near theoretical density, while sustaining the nanosized microstructure of raw powders. The sintering behavior, microstructure and mechanical properties of Mg2Al4Si5O18 were evaluated. The fracture toughness of a nanostructured Mg2Al4Si5O18 compound was higher than that of sub-micron Mg2Al4Si5O18 compound.

1-[(1,3-Dithio­lan-2-yl)meth­yl]-6-methyl-8-nitro-1,2,3,5,6,7-hexa­hydro­imidazo[1,2-c]pyrimidine

PubMed Central

Tian, Zhongzhen; Dong, Haijun; Li, Dongmei; Wang, Gaolei

2010-01-01

In the title compound, C11H18N4O2S2, the dithiol­ane ring displays an envelope conformation, the tetra­hydro­pyrimidine ring has a conformation that is between half-chair and screw-boat, and the imidazole ring is essentially planar (r.m.s. deviation = 0.0017 Å). No significant directional inter­molecular inter­actions are present in the structure. PMID:21588676

Micropollutants removal by full-scale UV-C/sulfate radical based Advanced Oxidation Processes.

PubMed

Rodríguez-Chueca, J; Laski, E; García-Cañibano, C; Martín de Vidales, M J; Encinas, Á; Kuch, B; Marugán, J

2018-07-15

The high chemical stability and the low biodegradability of a vast number of micropollutants (MPs) impede their correct treatment in urban wastewater treatment plants. In most cases, the chemical oxidation is the only way to abate them. Advanced Oxidation Processes (AOPs) have been experimentally proved as efficient in the removal of different micropollutants at lab-scale. However, there is not enough information about their application at full-scale. This manuscript reports the application of three different AOPs based on the addition of homogeneous oxidants [hydrogen peroxide, peroxymonosulfate (PMS) and persulfate anions (PS)], in the UV-C tertiary treatment of Estiviel wastewater treatment plant (Toledo, Spain) previously designed and installed in the facility for disinfection. AOPs based on the photolytic decomposition of oxidants have been demonstrated as more efficient than UV-C radiation alone on the removal of 25 different MPs using low dosages (0.05-0.5 mM) and very low UV-C contact time (4-18 s). Photolysis of PMS and H 2 O 2 reached similar average MPs removal in all the range of oxidant dosages, obtaining the highest efficiency with 0.5 mM and 18 s of contact time (48 and 55% respectively). Nevertheless, PMS/UV-C reached slightly higher removal than H 2 O 2 /UV-C at low dosages. So, these treatments are selective to degrade the target compounds, obtaining different removal efficiencies for each compound regarding the oxidizing agent, dosages and UV-C contact time. In all the cases, H 2 O 2 /UV-C is more efficient than PMS/UV-C, comparing the ratio cost:efficiency (€/m 3 ·order). Even H 2 O 2 /UV-C treatments are more efficient than UV-C alone. Thus, the addition of 0.5 mM of H 2 O 2 compensates the increased of UV-C contact time and therefore the increase of electrical consumption, that it should be need to increase the removal of MPs by UV-C treatments alone. Copyright © 2018 Elsevier B.V. All rights reserved.

Helixconstraints and amino acid substitution in GLP-1 increase cAMP and insulin secretion but not beta-arrestin 2 signaling.

PubMed

Plisson, Fabien; Hill, Timothy A; Mitchell, Justin M; Hoang, Huy N; de Araujo, Aline D; Xu, Weijun; Cotterell, Adam; Edmonds, David J; Stanton, Robert V; Derksen, David R; Loria, Paula M; Griffith, David A; Price, David A; Liras, Spiros; Fairlie, David P

2017-02-15

Glucagon-like peptide (GLP-1) is an endogenous hormone that induces insulin secretion from pancreatic islets and modified forms are used to treat diabetes mellitus type 2. Understanding how GLP-1 interacts with its receptor (GLP-1R) can potentially lead to more effective drugs. Modeling and NMR studies of the N-terminus of GLP-1 suggest a β-turn between residues Glu9-Phe12 and a kinked alpha helix between Val16-Gly37. N-terminal turn constraints attenuated binding affinity and activity (compounds 1-8). Lys-Asp (i, i+4) crosslinks in the middle and at the C-terminus increased alpha helicity and cAMP stimulation without much effect on binding affinity or beta-arrestin 2 recruitment (compounds 9-18). Strategic positioning of helix-inducing constraints and amino acid substitutions (Tyr16, Ala22) increased peptide helicity and produced ten-fold higher cAMP potency (compounds 19-28) over GLP-1(7-37)-NH 2 . The most potent cAMP activator (compound 23) was also the most potent inducer of insulin secretion. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Crystalline Structure and Physical Properties of UCo2Al3

NASA Astrophysics Data System (ADS)

Verdín, E.; Escudero, R.

Some intermetallic compounds which contain uranium or cerium present heavy fermion characteristics. Take, for example, in the UM2Al3 (M=Pd, Ni) family, superconductivity and magnetism coexist and present heavy fermion behavior. This work presents the crystallographic characteristics and physical properties of a new compound of this family; the intermetallic compound UCo2Al3. Our initial crystallographic studies performed in a small single crystal show that the structure is hexagonal and similar to the UNi2Al3 and UPd2Al3 parent compounds. The space group is P6/mmm with a=5.125 Å and c=4.167 Å crystalline parameters. Measurements of resistivity and magnetization performed on the single crystal reveal that the compound is not superconducting when measured at about 1.8 K. The compound is highly anisotropic and features related to Kondo-like behavior are observed. A weak ferromagnetic transition is observed at a temperature of about 20 K.

Lipoic acid inhibits cell proliferation of tumor cells in vitro and in vivo

PubMed Central

Feuerecker, Benedikt; Pirsig, Sabine; Seidl, Christof; Aichler, Michaela; Feuchtinger, Annette; Bruchelt, Gernot; Senekowitsch-Schmidtke, Reingard

2012-01-01

Cancer cells convert glucose preferentially to lactate even in the presence of oxygen (aerobic glycolysis–Warburg effect). New concepts in cancer treatment aim at inhibition of aerobic glycolysis. Pyruvate dehydrogenase converts pyruvate to acetylCoA thus preventing lactate formation. Therefore, the aim of this study was to evaluate compounds that could activate pyruvate dehydrogenase in cancer cells. We investigated the effects of (R)-(+)-α-lipoic acid (LPA) and dichloroacetate (DCA), possible activators of pyruvate dehydrogenase, on suppression of aerobic glycolysis and induction of cell death. The neuroblastoma cell lines Kelly, SK-N-SH, Neuro-2a and the breast cancer cell line SkBr3 were incubated with different concentrations (0.1–30 mM) of LPA and DCA. The effects of both compounds on cell viability/proliferation (WST-1 assay), [18F]-FDG uptake, lactate production and induction of apoptosis (flow cytometric detection of caspase-3) were evaluated. Furthermore, NMRI nu/nu mice that had been inoculated s.c. with SkBr3 cells were treated daily for four weeks with LPA (i.p, 18.5 mg/kg) starting at day 7 p.i.. Tumor development was measured with a sliding calliper and monitored via [18F]-FDG-PET. Residual tumors after therapy were examined histopathologically. These data suggests that LPA can reduce (1) cell viability/proliferation, (2) uptake of [18F]-FDG and (3) lactate production and increase apoptosis in all investigated cell lines. In contrast, DCA was almost ineffective. In the mouse xenograft model with s.c. SkBr3 cells, daily treatment with LPA retarded tumor progression. Therefore, LPA seems to be a promising compound for cancer treatment. PMID:22954700

Experimental design for extraction and quantification of phenolic compounds and organic acids in white "Vinho Verde" grapes.

PubMed

Dopico-García, M S; Valentão, P; Guerra, L; Andrade, P B; Seabra, R M

2007-01-30

An experimental design was applied for the optimization of extraction and clean-up processes of phenolic compounds and organic acids from white "Vinho Verde" grapes. The developed analytical method consisted in two steps: first a solid-liquid extraction of both phenolic compounds and organic acids and then a clean-up step using solid-phase extraction (SPE). Afterwards, phenolic compounds and organic acids were determined by high-performance liquid chromatography (HPLC) coupled to a diode array detector (DAD) and HPLC-UV, respectively. Plackett-Burman design was carried out to select the significant experimental parameters affecting both the extraction and the clean-up steps. The identified and quantified phenolic compounds were: quercetin-3-O-glucoside, quercetin-3-O-rutinoside, kaempferol-3-O-rutinoside, isorhamnetin-3-O-glucoside, quercetin, kaempferol and epicatechin. The determined organic acids were oxalic, citric, tartaric, malic, shikimic and fumaric acids. The obtained results showed that the most important variables were the temperature (40 degrees C) and the solvent (acid water at pH 2 with 5% methanol) for the extraction step and the type of sorbent (C18 non end-capped) for the clean-up step.

Synthesis, anti-proliferative activity, SAR study, and preliminary in vivo toxicity study of substituted N,N'-bis(arylmethyl)benzimidazolium salts against a panel of non-small cell lung cancer cell lines.

PubMed

Shelton, Kerri L; DeBord, Michael A; Wagers, Patrick O; Southerland, Marie R; Williams, Travis M; Robishaw, Nikki K; Shriver, Leah P; Tessier, Claire A; Panzner, Matthew J; Youngs, Wiley J

2017-01-01

A series of N,N'-bis(arylmethyl)benzimidazolium salts have been synthesized and evaluated for their in vitro anti-cancer activity against select non-small cell lung cancer cell lines to create a structure activity relationship profile. The results indicate that hydrophobic substituents on the salts increase the overall anti-proliferative activity. Our data confirms that naphthylmethyl substituents at the nitrogen atoms (N 1 (N 3 )) and highly lipophilic substituents at the carbon atoms (C 2 and C 5 (C 6 )) can generate benzimidazolium salts with anti-proliferative activity that is comparable to that of cisplatin. The National Cancer Institute's Developmental Therapeutics Program tested 1, 3-5, 10, 11, 13-18, 20-25, and 28-30 in their 60 human tumor cell line screen. Results were supportive of data observed in our lab. Compounds with hydrophobic substituents have higher anti-cancer activity than compounds with hydrophilic substituents. Copyright © 2016 Elsevier Ltd. All rights reserved.

Pharmacokinetics of [6]-shogaol, a pungent ingredient of Zingiber officinale Roscoe (Part I).

PubMed

Asami, Akitoshi; Shimada, Tsutomu; Mizuhara, Yasuharu; Asano, Takayuki; Takeda, Shuichi; Aburada, Takashi; Miyamoto, Ken-Ichi; Aburada, Masaki

2010-07-01

To investigate the pharmacokinetics of [6]-shogaol, a pungent ingredient of Zingiber officinale Roscoe, the pharmacokinetic parameters were determined by using (14)C-[6]-shogaol (labeled compound) and [6]-shogaol (non-labeled compound). When the labeled compound was orally administered to rats, the maximum plasma concentration (C (max)) and the area under the curve (AUC) of plasma radioactivity concentration increased in a dose-dependent manner. When the labeled compound was orally administered at a dose of 10 mg/kg, 20.0 + or - 1.8% of the radioactivity administered was excreted into urine, 64.0 + or - 12.9% into feces, and 0.2 + or - 0.1% into breath. Thus, more of the radioactivity was excreted into feces than into urine, and almost no radioactivity was excreted into breath. Furthermore, when the labeled compound was orally administered at a dose of 10 mg/kg, cumulative biliary radioactivity excretion over 48 h was 78.5 + or - 4.5% of the radioactivity administered, and cumulative urinary radioactivity excretion over 48 h was 11.8 + or - 2.7%, showing that about 90% of the dose administered orally was absorbed from the digestive tract and most of the fecal excretion was via biliary excretion. On the other hand, when the non-labeled compound [6]-shogaol was orally administered, the plasma concentration and biliary excretion of the unchanged form were extremely low. When these results are combined with those obtained with the labeled compound, it would suggest that [6]-shogaol is mostly metabolized in the body and excreted as metabolites.

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

Buragohain, Amlan; Couck, Sarah; Van Der Voort, Pascal

Four existing and three new functionalized chromium terephthalates having MIL-101 topology and denoted as Cr-MIL-101-X (existing ones with X=–F, 1-F; –Cl, 2-Cl; –Br, 3-Br; –CH{sub 3}, 4-CH{sub 3}; new ones with X=–C{sub 6}H{sub 4}, 5-C{sub 6}H{sub 4}; –F{sub 2}, 6-F{sub 2}, –(CH{sub 3}){sub 2}, 7-(CH{sub 3}){sub 2}) were synthesized under hydrothermal conditions. All the materials except 5-C{sub 6}H{sub 4} could be prepared by a general synthetic route, in which the mixtures of CrO{sub 3}, H{sub 2}BDC-X (BDC=1,4-benzenedicarboxylate) linkers, conc. HCl and water with a molar ratio of 1:1:3.9:222.2 were reacted at 180 °C for 144 h. Compared to the 144more » h of synthesis time, three of the compounds, namely 1-Cl, 2-Br and 5-C{sub 6}H{sub 4}, could be prepared in much shorter reaction times (12–18 h at 180–210 °C). The materials possess high thermal stability up to 270–300 °C in an air atmosphere. The activated compounds exhibit significant porosity (S{sub BET} range: 1273–2135 m{sup 2} g{sup −1}). At 0 °C and 1 bar, the CO{sub 2} adsorption capacities of the compounds fall in the 1.7–2.9 mmol g{sup −1} range. Compounds 1-F and 6-F{sub 2} showed enhanced CO{sub 2} uptake values compared to parent Cr-MIL-101. The benzene adsorption capacities of the compounds lie in the range of 66.2–139.5 molecules per unit cell at 50 °C and p/p{sub 0}=0.35. The increased benzene uptake value of 1-F compared to un-functionalized Cr-MIL-101 and 4-CH{sub 3} suggests that the fluorination has induced more hydrophobicity in Cr-MIL-101 as compared to the methylation. - Graphical abstract: Benzene adsorption by seven functionalized Cr-MIL-101-X metal-organic framework (MOF) materials Display Omitted - Highlights: • Seven functionalized Cr-MIL-101-X materials were synthesized solvothermally. • All Cr-MIL-101-X materials exhibited high thermal stability up to 270–300 °C in air. • All Cr-MIL-101-X compounds displayed considerable porosity towards N{sub 2}, CO{sub 2} and benzene. • Mono- and di-fluorinated Cr-MIL-101 materials showed enhanced CO{sub 2} adsorption capacities. • Cr-MIL-101-F adsorbed more benzene than non- and methyl-functionalized Cr-MIL-101.« less

Purification and characterization of two new cell-bound bioactive compounds produced by wild Lactococcus lactis strain.

PubMed

Saraiva, Margarete Alice Fontes; Brede, Dag Anders; Nes, Ingolf Figved; Baracat-Pereira, Maria Cristina; de Queiroz, Marisa Vieira; de Moraes, Célia Alencar

2017-07-03

Novel compounds and innovative methods are required considering that antibiotic resistance has reached a crisis point. In the study, two cell-bound antimicrobial compounds produced by Lactococcus lactis ID1.5 were isolated and partially characterized. Following purification by cationic exchange and a solid-phase C18 column, antimicrobial activity was recovered after three runs of RPC using 60% (v/v) and 100% (v/v) of 2-propanol for elution, suggesting that more than one antimicrobial compound were produced by L. lactis ID1.5, which were in this study called compounds AI and AII. The mass spectrum of AI and AII showed major intensity ions at m/z 1070.05 and 955.9 Da, respectively. The compound AI showed a spectrum of antimicrobial activity mainly against L. lactis species, while the organisms most sensitive to compound AII were Bacillus subtilis, Listeria innocua, Streptococcus pneumoniae and Pseudomonas aeruginosa. The antimicrobial activity of both compounds was suppressed by treatment with Tween 80. Nevertheless, both compounds showed high stability to heat and proteases treatments. The isolated compounds, AI and AII, showed distinct properties from other antimicrobial substances already reported as produced by L. lactis, and have a significant inhibitory effect against two clinically important respiratory pathogens. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Effectiveness of high-throughput miniaturized sorbent- and solid phase microextraction techniques combined with gas chromatography-mass spectrometry analysis for a rapid screening of volatile and semi-volatile composition of wines--a comparative study.

PubMed

Mendes, Berta; Gonçalves, João; Câmara, José S

2012-01-15

In this study the feasibility of different extraction procedures was evaluated in order to test their potential for the extraction of the volatile (VOCs) and semi-volatile constituents (SVOCs) from wines. In this sense, and before they could be analysed by gas chromatography-quadrupole first stage masss spectrometry (GC-qMS), three different high-throughput miniaturized (ad)sorptive extraction techniques, based on solid phase extraction (SPE), microextraction by packed sorbents (MEPS) and solid phase microextraction (SPME), were studied for the first time together, for the extraction step. To achieve the most complete volatile and semi-volatile signature, distinct SPE (LiChrolut EN, Poropak Q, Styrene-Divinylbenzene and Amberlite XAD-2) and MEPS (C(2), C(8), C(18), Silica and M1 (mixed C(8)-SCX)) sorbent materials, and different SPME fibre coatings (PA, PDMS, PEG, DVB/CAR/PDMS, PDMS/DVB, and CAR/PDMS), were tested and compared. All the extraction techniques were followed by GC-qMS analysis, which allowed the identification of up to 103 VOCs and SVOCs, distributed by distinct chemical families: higher alcohols, esters, fatty acids, carbonyl compounds and furan compounds. Mass spectra, standard compounds and retention index were used for identification purposes. SPE technique, using LiChrolut EN as sorbent (SPE(LiChrolut EN)), was the most efficient method allowing for the identification of 78 VOCs and SVOCs, 63 and 19 more than MEPS and SPME techniques, respectively. In MEPS technique the best results in terms of number of extractable/identified compounds and total peak areas of volatile and semi-volatile fraction, were obtained by using C(8) resin whereas DVB/CAR/PDMS was revealed the most efficient SPME coating to extract VOCs and SVOCs from Bual wine. Diethyl malate (18.8±3.2%) was the main component found in wine SPE(LiChrolut EN) extracts followed by ethyl succinate (13.5±5.3%), 3-methyl-1-butanol (13.2±1.7%), and 2-phenylethanol (11.2±9.9%), while in SPME(DVB/CAR/PDMS) technique 3-methyl-1-butanol (43.3±0.6%) followed by diethyl succinate (18.9±1.6%), and 2-furfural (10.4±0.4%), are the major compounds. The major VOCs and SVOCs isolated by MEPS(C8) were 3-methyl-1-butanol (26.8±0.6%, from wine total volatile fraction), diethyl succinate (24.9±0.8%), and diethyl malate (16.3±0.9%). Regardless of the extraction technique, the highest extraction efficiency corresponds to esters and higher alcohols and the lowest to fatty acids. Despite some drawbacks associated with the SPE procedure such as the use of organic solvents, the time-consuming and tedious sampling procedure, it was observed that SPE(LiChrolut EN), revealed to be the most effective technique allowing the extraction of a higher number of compounds (78) rather than the other extraction techniques studied. Copyright © 2011 Elsevier B.V. All rights reserved.

Ionic liquids as advantageous solvents for headspace gas chromatography of compounds with low vapor pressure.

PubMed

Andre, M; Loidl, J; Laus, G; Schottenberger, H; Bentivoglio, G; Wurst, K; Ongania, K-H

2005-01-15

The potential of ionic liquids as solvents for headspace gas chromatography was investigated. Three compounds with boiling points above 200 degrees C were selected to demonstrate the feasibility of the concept described. 2-Ethylhexanoic acid, formamide, and tri-n-butylamine as examples of acidic, neutral, and basic analytes were dissolved in acidic 1-n-butyl-3-methylimidazolium hydrogen sulfate (1), neutral 1-n-butyl-2,3-dimethylimidazolium dicyanamide (2), and 2 containing 1,8-diazabicyclo[5.4.0]undec-7-ene to adjust basic conditions. All analytes could be determined with limits of detection and limits of quantification in the low-ppm concentration range.

Total Syntheses of (-)-Mersicarpine, (-)-Scholarisine G, (+)-Melodinine E, (-)-Leuconoxine, (-)-Leuconolam, (-)-Leuconodine A, (+)-Leuconodine F, and (-)-Leuconodine C: Self-Induced Diastereomeric Anisochronism (SIDA) Phenomenon for Scholarisine G and Leuconodines A and C.

PubMed

Xu, Zhengren; Wang, Qian; Zhu, Jieping

2015-05-27

Enantioselective total syntheses of title natural products from a common cyclohexenone derivative (S)-18 were reported. Ozonolysis of (S)-18 afforded a stable diketo ester (R)-17 that was subsequently converted to two skeletally different natural products, i.e., (-)-mersicarpine (8) with a [6.5.6.7] fused tetracyclic ring system and (-)-scholarisine G (9) with a [6.5.6.6.5] fused pentacyclic skeleton, respectively. The postcyclization diversification was realized by taking advantage of the facile conversion of (+)-melodinine E (6) to N-acyliminium ion 7, from which a hydroxy group was selectively introduced to the C6, C7, C10 and the central C21 position of diazafenestrane system, leading to (-)-leuconodine A (11), (+)-leuconodine F (12), (-)-scholarisine G (9), (-)-leuconodine C (13), and skeletally different (-)-leuconolam (5). Furthermore, an unprecedented non-natural oxabridged oxadiazafenestrane 68 was formed by oxidation of (+)-melodinine E (6). During the course of this study, a strong self-induced diastereomeric anisochronism (SIDA) phenomenon was observed for scholarisine G (9), leuconodines A (11) and C (13). X-ray structures of both the racemic and the enantiopure natural products 9, 11, and 13 were obtained. The different crystal packing of these two forms nicely explained the chemical shift differences observed in the (1)H NMR spectra of the racemic and the enantio-enriched compounds in an achiral environment.

Turn on macrocyclic chemosensor for Al3+ ion with facile synthesis and application in live cell imaging

NASA Astrophysics Data System (ADS)

Ezhumalai, Dhineshkumar; Mathivanan, Iyappan; Chinnadurai, Anbuselvan

2018-06-01

An effort of a new Schiff base macrocyclic chemosensor, 14‑methyl‑2,6,8,12,14,18‑hexaaza‑1,7,13(1,2),4,10,16(1,4)‑hexabenzenacyclooctadecaphane‑2,5,8,11,14,17‑hexaene (me1) and 14,74‑dimethyl‑2,6,8,12,14,18‑hexaaza‑1,7,13(1,2),4,10,16(1,4)‑hexabenzenacyclooctadecadecaphane‑2,5,8,11,14,17‑hexaene (dm2), which enables selective sensing of Al3+ in aqueous DMF were synthesized by a simplistic one-step condensation reaction of macrocyclic compounds. The probe me1 and dm2 characterized by elemental analysis, FT-IR, 1H and 13C NMR, LC-MS spectral techniques. The compounds as mentioned above subjected to FE-SEM with EDS and elemental color mapping. On addition of Al3+, the fluorescent probe me1 and dm2 induces turn-on responses in both absorption and sensing spectra by a PET mechanism. The receptor me1 and dm2 serve highly selective, sensitive and turn-on detection of Al3+. Further, they did not interfere with other cations present in biological or environmental samples. The detection limit is found to be 3 μM and 5 μM. From the view of cytotoxic activity, the ability of these compounds me1 and dm2 to inhibit the growth of KB cell lines examined. The chelating functionality of compounds me1 and dm2 examined for their inhibitory properties of KB cell, live cell images. The compounds me1 and dm2 subjected to theoretical studies by DFT-B3LYP invoking the 6-31G level of theory. The energy of the HOMO and LUMO has been established.

Composition and antimicrobial activity of fatty acids detected in the hygroscopic secretion collected from the secretory setae of larvae of the biting midge Forcipomyia nigra (Diptera: Ceratopogonidae).

PubMed

Urbanek, Aleksandra; Szadziewski, Ryszard; Stepnowski, Piotr; Boros-Majewska, Joanna; Gabriel, Iwona; Dawgul, Małgorzata; Kamysz, Wojciech; Sosnowska, Danuta; Gołębiowski, Marek

2012-09-01

The hygroscopic secretion produced by the secretory setae of terrestrial larvae of the biting midge Forcipomyia nigra (Winnertz) was analysed using gas chromatography coupled with mass spectrometry (GC-MS). The viscous secretion is stored at the top of each seta and absorbs water from moist air. GC-MS analyses (four independent tests) showed that the secretion contained 12 free fatty acids, the most abundant of which were oleic (18:1), palmitic (16:0), palmitoleic (16:1) and linoleic (18:2). Other acids identified were valeric (5:0), enanthic (7:0), caprylic (8:0), pelargonic (9:0), capric (10:0), lauric (12:0), myristic (14:0) and stearic (18:0). Two other compounds, glycerol and pyroglutamic acid, were also found. The antibacterial activity of the fatty acids and pyroglutamic acid was tested using the agar disc diffusion method and targeted Gram positive (Bacillus cereus, Bacillus subtilis, Enterococcus faecalis) and Gram negative bacterial strains (Citrobacter freundii, Pseudomonas aeruginosa, Pseudomonas fluorescens). The antifungal activity was tested by determining minimal inhibitory concentration (MIC) of examined compounds. Fatty acids were tested against enthomopathogenic fungi (Paecilomyces lilacinus, Paecilomyces fumosoroseus, Lecanicillium lecanii, Metarhizium anisopliae, Beauveria bassiana (Tve-N39), Beauveria bassiana (Dv-1/07)). The most effective acids against bacterial and fungal growth were C(9:0), C(10:0) and C(16:1), whereas C(14:0), C(16:0,) C(18:0) and C(18:1) demonstrated rather poor antifungal activity and did not inhibit the growth of bacteria. The antimicrobial assay investigated mixtures of fatty and pyroglutamic acids (corresponding to the results of each GC-MS test): they were found to be active against almost all the bacteria except P. fluorescens and also demonstrated certain fungistatic activity against enthomopathogenic fungi. The hygroscopic secretion facilitates cuticular respiration and plays an important role in the antimicrobial protection of F. nigra larvae living in moist terrestrial habitats. Copyright © 2012 Elsevier Ltd. All rights reserved.

An endophytic Coniochaeta velutina producing broad spectrum antimycotics.

PubMed

Xie, Jie; Strobel, Gary A; Feng, Tao; Ren, Huishuang; Mends, Morgan T; Zhou, Zeyang; Geary, Brad

2015-06-01

An endophyte (PC27-5) was isolated from stem tissue of Western hemlock (Tsuga heterophylla) in a Pacific Northwest temperate rainforest. Phylogenetic analyses, based on ITS-5.8S rDNA and 18S rDNA sequence data, combined with cultural and morphological analysis showed that endophyte PC27-5 exhibited all characteristics of a fungus identical to Coniochaeta velutina. Furthermore, wide spectrum antimycotics were produced by this endophyte that were active against such plant pathogens as Sclerotinia sclerotiorum, Pythium ultimum, and Verticillium dahliae and lethal to Phythophthora cinnamomi, Pythium ultimum, and Phytophthora palmivora in plate tests. The bioactive components were purified through organic solvent extraction, followed by silica column chromatography, and finally preparative HPLC. The minimum inhibitory concentration of the active fraction to Pythium ultimum, which was gained from preparative HPLC, was 11 μg/ml. UPLC-HRMS analysis showed there were two similar components in the antimycotic fraction. Their molecular formulae were established as C30H22O11 (compound I) and C30H22O10 (compound II) respectively, and preliminary spectral results indicate that they are anthroquinone glycosides. Other non-biologically active compounds were identified in culture fluids of this fungus by spectral means as emodin and chrysophanol--anthroquinone derivatives. This is the first report that Coniochaeta velutina as an endophyte produces bioactive antifungal components.

Chromatographic behavior of small organic compounds in low-temperature high-performance liquid chromatography using liquid carbon dioxide as the mobile phase.

PubMed

Motono, Tomohiro; Nagai, Takashi; Kitagawa, Shinya; Ohtani, Hajime

2015-07-01

Low-temperature high-performance liquid chromatography, in which a loop injector, column, and detection cell were refrigerated at -35ºC, using liquid carbon dioxide as the mobile phase was developed. Small organic compounds (polyaromatic hydrocarbons, alkylbenzenes, and quinones) were separated by low-temperature high-performance liquid chromatography at temperatures from -35 to -5ºC. The combination of liquid carbon dioxide mobile phase with an octadecyl-silica (C18 ) column provided reversed phase mode separation, and a bare silica-gel column resulted in normal phase mode separation. In both the cases, nonlinear behavior at approximately -15ºC was found in the relationship between the temperature and the retention factors of the analytes (van't Hoff plots). In contrast to general trends in high-performance liquid chromatography, the decrease in temperature enhanced the separation efficiency of both the columns. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

A chromatographic estimate of the degree of surface heterogeneity of reversed-phase liquid chromatography packing materials II-Endcapped monomeric C18-bonded stationary phase

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

Gritti, Fabrice; Guiochon, Georges A

2006-01-01

In a previous report, the heterogeneity of a non-endcapped C{sub 30}-bonded stationary phase was investigated, based on the results of the measurements of the adsorption isotherms of two neutral compounds (phenol and caffeine) and two ionizable compounds (sodium naphthalene sulfonate and propranololium chloride) by frontal analysis (FA). The same method is applied here for the characterization of the surface heterogeneity of two new brands of endcapped C{sub 18}-bonded stationary phases (Gemini and Sunfire). The adsorption isotherms of the same four chemicals were measured by FA and the results confirmed by the independent calculation of the adsorption energy distribution (AED), usingmore » the expectation-maximization (EM) method. The effect of the length of the bonded alkyl chain was investigated. Shorter alkyl-bonded-chains (C{sub 18} versus C{sub 30}) and the end-capping of the silica surface contribute to decrease the surface heterogeneity under the same experimental conditions (30% methanol, 25 mM NaCl). The AEDs of phenol and caffeine are bimodal with the C{sub 18}-bonded columns while they are trimodal and quadrimodal, respectively, with a non-endcapped C{sub 30}-bonded column. The 'supersites' (adsorption energy >20 kJ/mol) found on the C{sub 30}-Prontosil column and attributed to a cation exchange mechanism completely disappear on the C{sub 18}-Gemini and C{sub 18}-Sunfire, probably because the end-capping of the silica surface eliminates most if not all the ionic interactions.« less

[Preparation of a novel activated carbon coating fiber for solid phase micro-extraction and its application for halocarbon compound analysis in water].

PubMed

Wang, Shutao; Wang, Yan; You, Hong; Liang, Zhihua

2004-09-01

A novel activated carbon coating fiber used for solid phase micro-extraction (SPME) was prepared using activated carbon powder and silica resin adhesive. The extraction properties of the novel activated carbon coating fiber were investigated. The results indicate that this coating fiber has high concentration ability, with enrichment factors for chloroform, carbon tetrachloride, trichloroethylene and tetrachloroethylene in the range of 13.8 to 18.7. The fiber is stable at temperature as high as 290 degrees C and it can be used for over 140 times at 250 degrees C. The activated carbon coating fiber was then applied to the analysis of the four halocarbon compounds mentioned above. A linear correlation with correlation coefficients between 0.995 2 and 0.999 4 and the detection limits between 0.008 and 0.05 microg/L were observed. The method was also applied to a real water sample analysis and the recoveries of these halocarbon compounds were from 95.5% to 104.6%.

Separation of three phenolic high-molecular-weight compounds from the crude extract of Terminalia Chebula Retz. by ultrasound-assisted extraction and high-speed counter-current chromatography.

PubMed

Zou, Deng-lang; Chen, Tao; Li, Hong-mei; Chen, Chen; Zhao, Jing-yang; Li, Yu-lin

2016-04-01

This study presents an efficient strategy for separation of three phenolic compounds with high molecular weight from the crude extract of Terminalia chebula Retz. by ultrasound-assisted extraction and high-speed counter-current chromatography. The ultrasound-assisted extraction conditions were optimized by response surface methodology and the results showed the target compounds could be well enriched under the optimized extraction conditions. Then the crude extract was directly separated by high-speed counter-current chromatography without any pretreatment using n-hexane/ethyl acetate/methanol/water (1:7:0.5:3, v/v/v/v) as the solvent system. In 180 min, 13 mg of A, 18 mg of B, and 9 mg of C were obtained from 200 mg of crude sample. Their structures were identified as Chebulagic acid (A, 954 Da), Chebulinic acid (B, 956 Da), and Ellagic acid (C) by (1) H NMR spectroscopy. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

[Ph(3)PCH(2)Ph](2)[Zn(3)(tp)(3)Cl(2)] and Ni(3)(tma)(2)(H(2)O)(8): two unusual claylike frameworks of metal-polycarboxylate coordination polymers (tp = terephthalate, tma = trimesate).

PubMed

Yang, Guo-Dong; Dai, Jing-Cao; Lian, Yun-Xia; Wu, Wen-Shi; Lin, Jian-Ming; Hu, Sheng-Min; Sheng, Tian-Lu; Fu, Zhi-Yong; Wu, Xin-Tao

2007-09-17

Two new compounds, [Ph3PCH2Ph]2[Zn3(tp)3Cl2] (1) and Ni3(tma)2(H2O)8 (2) (tp = terephthalate, tma = trimesate), are metal-polycarboxylate coordination polymers prepared by similar hydrothermal synthesis techniques. X-ray single-crystal structural analysis shows that both compounds crystallize in the 2D claylike lamellar architectures, in which 1 possesses the interlayer [Ph3PCH2Ph]+ exchangeable cation and has been confirmed by PXRD patterns. 1 (C74H56Cl2O12P2Zn3) belongs to monoclinic P21/c, Z = 2 (a = 18.956(1) A, b = 10.2697(5) A, c = 17.067(1) A, beta = 99.486(4) degrees ). 2 (C18H22O20Ni3) is attributed to triclinic P, Z = 1 (a = 6.6643(8) A, b = 9.622(1) A, c = 10.089(1) A, alpha = 112.675(2) degrees , beta = 94.007(1) degrees, gamma = 106.411(2) degrees ). Linear metal trinuclear clusters bridged by rigid linear tp ligands for 1 and trigonal tma ligands for 2 give rise to a novel 2D 6-linked (3,6) topological anionic network in 1 and an interesting 2D 3,6-linked molybdenite topological neutral network in 2, respectively. Both compounds exhibit intense fluorescent emission bands at 410 nm (lambda(exc) = 355 nm) for 1 and 398 nm (lambda(exc) = 300 nm) for 2 in the solid state at room temperature.

Synthesis and animal studies of L-para-(/sup 18/F)-fluorophenyl-alanine as probe for in vivo cerebral protein synthesis

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

Coenen, H.H.; Bodsch, W.; Takahashi, K.

For the quantitation of cerebral protein synthesis in man by dynamic PET studies, fluorine-18 analogues seem superior to carbon-11 labeled substrates with respect to half-life and interference of amino acid metabolism giving rise to reutilization. Therefore, para- and ortho- /sup 18/F- fluorophenylalanine were prepared to study its metabolism in neuronal tissue. A labeling method was developed using direct electrophilic fluorination with (/sup 18/F)-F/sub 2/. Reaction of fluorine with L-phenylalanine in CF/sub 3/CO/sub 2/H at O/sup 0/C yielded 12-15% of ortho- and 6-8% of para-/sup 18/F-flurorophenylalanine. Isolation of the isomers was achieved by means of repeated RP-HPLC. The specific activity wasmore » about 2 Ci/mmole at 100 min after EOB. Both compounds showed a pharmacokinetic behaviour in mice after i.v. injection typical for natural amino acids. The accumulation in mice brain tissue reaches a plateau value after 5 min with 1.7% of the injected dose/g for para (2.5% in gerbils) and 2% for ortho. In a pilot study, about 1 mCi of p-/sup 18/F-phenylalanine was coinjected with 0.3 mCi (100 Ci/mmole) /sup 3/H-phenylalanine into the femoral vein of halothane-anesthetized Mongolian gerbils. The distribution obtained autoradiographyically in 20 ..mu..m sections of the frozen brain of an animal after 45 min revealed a similar pattern for both compounds indicating protein synthesis. In a parallel study 3-/sup 14/C-para-fluorophenylalanine was used to determine the chemical form of radioactivity in brain by means of HPLC. After 45 minutes, 7% of total brain activity was found as free amino acid and 60% was incorporated into proteins.« less

Calculating in situ degradation rates of hydrocarbon compounds in deep waters of the Gulf of Mexico.

PubMed

Thessen, Anne E; North, Elizabeth W

2017-09-15

Biodegradation is an important process for hydrocarbon weathering that influences its fate and transport, yet little is known about in situ biodegradation rates of specific hydrocarbon compounds in the deep ocean. Using data collected in the Gulf of Mexico below 700m during and after the Deepwater Horizon oil spill, we calculated first-order degradation rate constants for 49 hydrocarbons and inferred degradation rate constants for an additional 5 data-deficient hydrocarbons. Resulting calculated (not inferred) half-lives of the hydrocarbons ranged from 0.4 to 36.5days. The fastest degrading hydrocarbons were toluene (k=-1.716), methylcyclohexane (k=-1.538), benzene (k=-1.333), and C1-naphthalene (k=-1.305). The slowest degrading hydrocarbons were the large straight-chain alkanes, C-26 through C-33 (k=-0.0494 through k=-0.007). Ratios of C-18 to phytane supported the hypothesis that the primary means of degradation in the subsurface was microbial biodegradation. These degradation rate constants can be used to improve models describing the fate and transport of hydrocarbons in the event of an accidental deep ocean oil spill. Copyright © 2017 Elsevier Ltd. All rights reserved.

4,5,7,8,17-Penta-hydr-oxy-14,18-dimethyl-6-methyl-ene-3,10-dioxapenta-cyclo-[9.8.0.0.0.0]nona-dec-14-ene-9,16-dione methanol solvate dihydrate.

PubMed

Teh, Chin Hoe; Teoh, Siew Chin; Yeap, Chin Sing; Chan, Kit Lam; Fun, Hoong-Kun

2009-03-28

The title quassinoid compound, C(20)H(24)O(9)·CH(3)OH·2H(2)O, is a natural eurycomanone isolated from the roots of Eurycoma longifolia. The mol-ecules contain a fused five-ring system, with one tetra-hydro-furan ring adopting an envelope conformation, one tetra-hydro-pyran-2-one ring in a screw boat conformation, one cyclo-hexenone ring in a half-chair conformation and two cyclo-hexane rings in chair conformations. Intra-molecular C-H⋯O inter-actions generate S(5) ring motifs and an O-H⋯O inter-action generates an S(7) ring motif. In the crystal, mol-ecules are linked via inter-molecular O-H⋯O inter-actions along the b axis and further stacked along a axis. The absolute configuration of the title compound was inferred from previously solved structures of its analogues.

Process for the production of 5'-deoxy-5-(/sup 18/F)fluorouridine

DOEpatents

Shiue, C.Y.; Wolf, A.P.; Friedkin, M.

1983-08-10

Process for the production of 5'-deoxy-5-fluorouridine and the corresponding /sup 18/F compound by the reaction of fluorine or acetyl hypofluorite with 2', 3'-di-O-acetyl-5'-deoxyuridine followed by hydrolysis.

Thauera humireducens sp. nov., a humus-reducing bacterium isolated from a microbial fuel cell.

PubMed

Yang, Gui-Qin; Zhang, Jun; Kwon, Soon-Wo; Zhou, Shun-Gui; Han, Lu-Chao; Chen, Ming; Ma, Chen; Zhuang, Li

2013-03-01

A Gram-negative, rod-shaped, non-spore-forming bacterium, designated SgZ-1(T), was isolated from the anode biofilm of a microbial fuel cell. The strain had the ability to grow under anaerobic condition via the oxidation of various organic compounds coupled to the reduction of anthraquione-2,6-disulfonate (AQDS) to anthrahydroquinone-2,6-disulfonate (AHQDS). Growth occurred in TSB in the presence of 0-5.5 % (w/v) NaCl (optimum 0-1 %), at 10-45 °C (optimum 25-37 °C) and at pH 6.0-10.0 (optimum 8.0-8.5). Based on 16S rRNA gene sequence similarity, strain SgZ-1(T) belonged to the genus Thauera. The highest level of 16S rRNA gene sequences similarity (96.7 %) was found to be with Thauera aminoaromatica S2(T) and Thauera selenatis AX(T), and lower values were obtained when compared with other recognized Thauera species. Chemotaxonomic analysis revealed that strain SgZ-1(T) contained Q-8 as the predominant quinone, and putrescine and 2-hydroxyputrescine as the major polyamines. The major cellular fatty acids (>5 %) were C16 : 1ω6c and/or C16 : 1ω7c (44.6 %), C16 : 0 (18.8 %), and C18 : 1ω6c and/or C18 : 1ω7c (12.7 %). Based on its phenotypic and phylogenetic properties, chemotaxonomic analysis and the results of physiological and biochemical tests, strain SgZ-1(T) ( = KACC 16524(T) = CCTCC M 2011497(T)) was designated the type strain of a novel species of the genus Thauera, for which the name Thauera humireducens sp. nov. was proposed.

Magnetostructural phase transitions and magnetocaloric effect in (Gd 5-xSc x)Si 1.8Ge 2.2

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

Rudolph, Kirk; Pathak, Arjun K.; Mudryk, Yaroslav

Future advancements in magnetocaloric refrigeration/heat pumping technologies depend on the discovery of new materials that demonstrate large, tunable magnetocaloric effects (MCEs) in the vicinity of coupled magnetic and structural phase transitions that occur reversibly with minimum hysteresis. Here, with this in mind, we investigate phase transitions, microstructure, magnetic, thermal, magnetocaloric, and transport properties of (Gd 5-xSc x)Si 1.8Ge 2.2 compounds. Replacement of magnetic Gd with non-magnetic Sc in Gd 5-xSc xSi 1.8Ge 2.2 increases the ferromagnetic to paramagnetic first order phase transition temperature, T C, with only a minor reduction in MCE when x ≤ 0.2. We also demonstrate thatmore » hydrostatic pressure further increases T C and reduces the hysteresis of the first order phase transition in Gd 4.8Sc 0.2Si 1.8Ge 2.2 from 7 to 4 K. Temperature-dependent x-ray powder diffraction study of Gd 4.8Sc 0.2Si 1.8Ge 2.2 confirms the monoclinic ↔ orthorhombic structural transformation at T C, in agreement with magnetic, calorimetric, and electrical transport measurements. In addition to the substantial magnetocaloric effect, a large magnetoresistance of ~20% is also observed in Gd 4.8Sc 0.2Si 1.8Ge 2.2 for ΔH = 50 kOe in the vicinity of the magnetostructural transition. Finally, in a drastic reversal of the initial doping behavior further additions of Sc (x > 0.2) suppress formation of the monoclinic phase, change the nature of the transition from first-to second-order, and reduce both the transition temperature and magnetocaloric effect.« less

Magnetostructural phase transitions and magnetocaloric effect in (Gd 5-xSc x)Si 1.8Ge 2.2

DOE PAGES

Rudolph, Kirk; Pathak, Arjun K.; Mudryk, Yaroslav; ...

2017-12-21

Future advancements in magnetocaloric refrigeration/heat pumping technologies depend on the discovery of new materials that demonstrate large, tunable magnetocaloric effects (MCEs) in the vicinity of coupled magnetic and structural phase transitions that occur reversibly with minimum hysteresis. Here, with this in mind, we investigate phase transitions, microstructure, magnetic, thermal, magnetocaloric, and transport properties of (Gd 5-xSc x)Si 1.8Ge 2.2 compounds. Replacement of magnetic Gd with non-magnetic Sc in Gd 5-xSc xSi 1.8Ge 2.2 increases the ferromagnetic to paramagnetic first order phase transition temperature, T C, with only a minor reduction in MCE when x ≤ 0.2. We also demonstrate thatmore » hydrostatic pressure further increases T C and reduces the hysteresis of the first order phase transition in Gd 4.8Sc 0.2Si 1.8Ge 2.2 from 7 to 4 K. Temperature-dependent x-ray powder diffraction study of Gd 4.8Sc 0.2Si 1.8Ge 2.2 confirms the monoclinic ↔ orthorhombic structural transformation at T C, in agreement with magnetic, calorimetric, and electrical transport measurements. In addition to the substantial magnetocaloric effect, a large magnetoresistance of ~20% is also observed in Gd 4.8Sc 0.2Si 1.8Ge 2.2 for ΔH = 50 kOe in the vicinity of the magnetostructural transition. Finally, in a drastic reversal of the initial doping behavior further additions of Sc (x > 0.2) suppress formation of the monoclinic phase, change the nature of the transition from first-to second-order, and reduce both the transition temperature and magnetocaloric effect.« less

Synthesis and antituberculosis activity of new fatty acid amides.

PubMed

D'Oca, Caroline Da Ros Montes; Coelho, Tatiane; Marinho, Tamara Germani; Hack, Carolina Rosa Lopes; Duarte, Rodrigo da Costa; da Silva, Pedro Almeida; D'Oca, Marcelo Gonçalves Montes

2010-09-01

This work reports the synthesis of new fatty acid amides from C16:0, 18:0, 18:1, 18:1 (OH), and 18:2 fatty acids families with cyclic and acyclic amines and demonstrate for the first time the activity of these compounds as antituberculosis agents against Mycobacterium tuberculosis H(37)Rv, M. tuberculosis rifampicin resistance (ATCC 35338), and M. tuberculosis isoniazid resistance (ATCC 35822). The fatty acid amides derivate from ricinoleic acid were the most potent one among a series of tested compounds, with a MIC 6.25 microg/mL for resistance strains. Copyright 2010 Elsevier Ltd. All rights reserved.

Terpenoids from Curcuma wenyujin increased glucose consumption on HepG2 cells.

PubMed

Zhou, Chang-Xin; Zhang, Li-Sha; Chen, Fei-Fei; Wu, Hao-Shu; Mo, Jian-Xia; Gan, Li-She

2017-09-01

Thirty four terpenoids, including two new cadinane-type sesquiterpenoids containing conjugated aromatic-ketone moieties, curcujinone A (1) and curcujinone B (2), were isolated from 95% ethanol extract of the root tubers of Curcuma wenyujin. Their structures were determined by spectroscopic methods, especially 2D NMR and HRMS techniques. The relative and absolute configurations of 1 and 2 were identified by quantum chemical DFT and TDDFT calculations of the 13 C NMR chemical shifts, ECD spectra, and specific optical rotations. All compounds and extracts were evaluated for their anti-diabetic activities with a glucose consumption model on HepG2 Cells. The petroleum fraction CWP (10μg/mL) and compounds curcumenol (4), 7α,11α-epoxy-5β-hydroxy-9-guaiaen-8-one (5), curdione (17), (1S, 4S, 5S 10S)-germacrone (18), zederone (20), a mixture of curcumanolide A (25) and curcumanolide B (26), gajutsulactone B (27), and wenyujinin C (30) showed promising activities with over 45% increasing of glucose consumption at 10μM. Copyright © 2017. Published by Elsevier B.V.

A novel reverse phase high-performance liquid chromatography method for standardization of Orthosiphon stamineus leaf extracts.

PubMed

Saidan, Noor Hafizoh; Aisha, Abdalrahim F A; Hamil, Mohd Shahrul Ridzuan; Majid, Amin Malik Shah Abdul; Ismail, Zhari

2015-01-01

Orthosiphon stamineus Benth. (Lamiaceae) is a traditional medicinal plant which has been used in treating various ailments such as kidney diseases, bladder inflammation, arthritis and diabetes. The leaves contain high concentration of phenolic compounds, thus, rosmarinic acid (RA), 3'-hydroxy-5, 6, 7, 4'-tetramethoxyflavone (TMF), sinensetin (SIN) and eupatorin (EUP) were chosen as a marker compounds for standardization of various O. stamineus leaf extracts. The aim was to develop and validate a new high-performance liquid chromatography (HPLC) method for quantification of 4 marker compounds (RA, TMF, SIN, EUP) in various O. stamineus leaf extracts. The method was developed and validated using RP-HPLC-diode-array detection at 320 nm for accuracy, precision and limits of detection and was applied for quantification of it markers in five different extracts prepared in solvents with increasing polarity, using a gradient mobile phase 0.1% formic acid: Acetonitrile at a flow rate of 1 ml/min on reverse phase acclaim polar advantage II C18 column (3 μm, 3 × 150 mm) with 18 min separation time. The developed method provided satisfactory precision, and the accuracy of this method was in the range of 90.2% to 105.5%. All of 4 compounds showed good linearity at R2 > 0.999. The developed method is a simple, cost effective with shorter run time (18 min) in comparison to previous methods (30 min) and utilization of environmental-friendly solvents system. Therefore, this method has the potential to replace currently used methods in the routine standardization work of O. stamineus extracts, raw materials and its commercial products.

A novel reverse phase high-performance liquid chromatography method for standardization of Orthosiphon stamineus leaf extracts

PubMed Central

Saidan, Noor Hafizoh; Aisha, Abdalrahim F.A.; Hamil, Mohd Shahrul Ridzuan; Majid, Amin Malik Shah Abdul; Ismail, Zhari

2015-01-01

Background: Orthosiphon stamineus Benth. (Lamiaceae) is a traditional medicinal plant which has been used in treating various ailments such as kidney diseases, bladder inflammation, arthritis and diabetes. The leaves contain high concentration of phenolic compounds, thus, rosmarinic acid (RA), 3’-hydroxy-5, 6, 7, 4’-tetramethoxyflavone (TMF), sinensetin (SIN) and eupatorin (EUP) were chosen as a marker compounds for standardization of various O. stamineus leaf extracts. Objective: The aim was to develop and validate a new high-performance liquid chromatography (HPLC) method for quantification of 4 marker compounds (RA, TMF, SIN, EUP) in various O. stamineus leaf extracts. Materials and Methods: The method was developed and validated using RP-HPLC-diode-array detection at 320 nm for accuracy, precision and limits of detection and was applied for quantification of it markers in five different extracts prepared in solvents with increasing polarity, using a gradient mobile phase 0.1% formic acid: Acetonitrile at a flow rate of 1 ml/min on reverse phase acclaim polar advantage II C18 column (3 μm, 3 × 150 mm) with 18 min separation time. Results: The developed method provided satisfactory precision, and the accuracy of this method was in the range of 90.2% to 105.5%. All of 4 compounds showed good linearity at R2 > 0.999. Conclusion: The developed method is a simple, cost effective with shorter run time (18 min) in comparison to previous methods (30 min) and utilization of environmental-friendly solvents system. Therefore, this method has the potential to replace currently used methods in the routine standardization work of O. stamineus extracts, raw materials and its commercial products. PMID:25598631

Structures, chemotaxonomic significance, cytotoxic and Na(+),K(+)-ATPase inhibitory activities of new cardenolides from Asclepias curassavica.

PubMed

Zhang, Rong-Rong; Tian, Hai-Yan; Tan, Ya-Fang; Chung, Tse-Yu; Sun, Xiao-Hui; Xia, Xue; Ye, Wen-Cai; Middleton, David A; Fedosova, Natalya; Esmann, Mikael; Tzen, Jason T C; Jiang, Ren-Wang

2014-11-28

Five new cardenolide lactates (1–5) and one new dioxane double linked cardenolide glycoside (17) along with 15 known compounds (6–16 and 18–21) were isolated from the ornamental milkweed Asclepias curassavica. Their structures were elucidated by extensive spectroscopic methods (IR, UV, MS, 1D- and 2D-NMR). The molecular structures and absolute configurations of 1–3 and 17 were further confirmed by single-crystal X-ray diffraction analysis. Simultaneous isolation of dioxane double linked cardenolide glycosides (17–21) and cardenolide lactates (1–5) provided unique chemotaxonomic markers for this genus. Compounds 1–21 were evaluated for the inhibitory activities against DU145 prostate cancer cells. The dioxane double linked cardenolide glycosides showed the most potent cytotoxic effect followed by normal cardenolides and cardenolide lactates, while the C21 steroids were non-cytotoxic. Enzymatic assay established a correlation between the cytotoxic effects in DU145 cancer cells and the Ki for the inhibition of Na(+),K(+)-ATPase. Molecular docking analysis revealed relatively strong H-bond interactions between the bottom of the binding cavity and compounds 18 or 20, and explained why the dioxane double linked cardenolide glycosides possessed higher inhibitory potency on Na(+),K(+)-ATPase than the cardenolide lactate.

Synthesis of Photoresponsive Dual NIR Two-Photon Absorptive [60]Fullerene Triads and Tetrads

PubMed Central

Jeon, Seaho; Wang, Min; Tan, Loon-Seng; Cooper, Thomas; Hamblin, Michael R.; Chiang, Long Y.

2013-01-01

Broadband nonlinear optical (NLO) organic nanostructures exhibiting both ultrafast photoresponse and a large cross-section of two-photon absorption throughout a wide NIR spectrum may make them suitable for use as nonlinear biophotonic materials. We report here the synthesis and characterization of two C60-(antenna)x analogous compounds as branched triad C60(>DPAF-C18)(>CPAF-C2M) and tetrad C60(>DPAF-C18)(>CPAF-C2M)2 nanostructures. These compounds showed approximately equal extinction coefficients of optical absorption over 400–550 nm that corresponds to near-IR two-photon based excitation wavelengths at 780–1,100 nm. Accordingly, they may be utilized as potential precursor candidates to the active-core structures of photosensitizing nanodrugs for 2γ-PDT in the biological optical window of 800–1,050 nm. PMID:23941881

Comamonas aquatilis sp. nov., isolated from a garden pond.

PubMed

Kämpfer, Peter; Busse, Hans-Jürgen; Baars, Sophie; Wilharm, Gottfried; Glaeser, Stefanie P

2018-04-01

A beige-pigmented bacterial strain, SB30-Chr27-3 T , isolated from a garden pond, was studied for its taxonomic position. Cells of the isolate were rod-shaped and stained Gram-negative. A comparison of the 16S rRNA gene sequence with the sequences of the type strains of the most closely related species showed that the strain belongs to the genus Comamonas and showed highest sequence similarities to the type strains of Comamonas jiangduensis (97.5 %), Comamonas aquatica (97.4 %) and Comamonas phosphati (97.3 %). The 16S rRNA gene sequence similarities to all other Comamonas species were below 97.0 %. The fatty acid profile of strain SB30-Chr27-3 T consisted of the major fatty acids C16 : 0, C15 : 0iso 2-OH/ C16 : 1ω7c, C18 : 1ω7c/C18 : 1ω9c and, in a minor amount, C10 : 0 3-OH. Major compounds in the polar lipid profile were phosphatidylethanolamine, phosphatidylglycerol, phosphatidylserine and diphosphatidylglycerol. The quinone system was exclusively composed of ubiquinone Q-8. The polyamine pattern contained the major compounds putrescine, cadaverine and 2-hydroxyputrescine. These data and the differentiating biochemical properties indicated that isolate SB30-CHR27-3 T represents a novel species of the genus Comamonas, for which we propose the name >Comamonas aquatilis sp. nov. with the type strain SB30-Chr27-3 T (=CIP 111491 T =CCM 8815 T ).

Fast dynamic electron transfer along infinite anion-cation chains in technetium and rhenium acido clusters

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

Antipov, B.G.; Kryuchkov, S.V.; Grigor`ev, M.S.

1995-09-01

New technetium and rhenium compounds with ferricenium cations - [Fe(C{sub 5}H{sub 5}){sub 2}]{sub 3}[Tc{sub 6}I{sub 14}], [Fe(C{sub 5}H{sub 5}){sub 2}]{sub 3}[Tc{sub 6}Cl{sub 14}], [Fe(C{sub 5}H{sub 5}){sub 2}]{sub 2}[Tc{sub 8}Br{sub 14}], and [Fe(C{sub 5}H{sub 5}){sub 2}]{sub 2}[Re{sub 2}Br{sub 8}] - are synthesized and identified. The compounds are characterized by the methods of static magnetic susceptibility and differential scanning calorimetry; solid-state conductivity measurements; and IR, EPR, {sup 57}Fe Moessbauer, and X-ray photoelectron spectroscopic data. These data are compared with the physicochemical characteristics of ferricenium pertechnetate and hexachlorotechnetate, as well as of a number of reference technetium and rhenium compounds containing the samemore » anions but different cations. The structure of [Fe(C{sub 5}H{sub 5}){sub 2}]{sub 3}[Tc{sub 6}I{sub 14}] is determined by X-ray diffraction analysis of a single crystal [space group P6/m, a = 15.34(2), c = 12.70(1) {angstrom}]. The structures of the remaining compounds were confirmed by comparing their spectroscopic properties with corresponding properties of compounds with known composition and structure. None of the compounds with ferricenium cations exhibit covalent or other localized bonds between anions and cations. However, the physicochemical properties of these compounds indicate the occurrence of a fast dynamic electron transfer along infinite anion-cation chains. Compounds [Fe(C{sub 5}H{sub 5}){sub 2}]{sub 3}[Tc{sub 6}Cl{sub 14}] and [Fe(C{sub 5}H{sub 5}){sub 2}]{sub 2}[Tc{sub 8}Br{sub 14}] were found to exhibit a new phenomenon of X-ray-induced low-temper ature high-energy electron emission.« less

Mercury-Bridged Cobaltacarborane Complexes Containing B-Hg-B Three-Center Bonds. Synthesis and Structure of mu, mu’-((n5-C5R5)Co(CH3)2C2B3H4)Hg, mu-(n(5)-C5R5)Co(CH3)2C2B3H4)HgCl, (R=H, CH3) and Related Compounds.

DTIC Science & Technology

1980-11-01

MERCURY-BRIDGED COBALTACARBORANE COMPLEXES CONTAINING B-HG-B TH--ETC(U) NOV 80 D C FINSTER . R N GRIMES N0 0 0 1 4-75-0305 UNCLASSXFIED TR󈧨 NL ILn...C5R5) Co 3)2C2B3 4 2 5 .- -C5R5 )Co(CH3)2C2B3H4 ]HgCl, (R=H, CH3 ) and Related Compounds, David C./ Finster -- Russell N./Grimes ( Department of Chemistry...Compounds 1 \\David C. Finster And Russell N. Grimes* Abstract. Reactions of the nid~p-cobaltacarborane anions 01CR )(C 3 )C BH and [n (H 1oC ihH~5n 5

4-{2-[2-(4-Formyl-phen-oxy)eth-oxy]eth-oxy}benzaldehyde.

PubMed

Ma, Zhen; Cao, Yiqun

2011-06-01

The title compound, C(18)H(18)O(5), was obtained by the reaction of 4-hy-droxy-benzaldehyde with bis-(2,2-dichloro-eth-yl) ether in dimethyl-formamide. In the crystal, the mol-ecule lies on a twofold rotation axis that passes through the central O atom of the aliphatic chain, thus leading to one half-mol-ecule being present per asymmetric unit. The carbonyl, aryl and O-CH(2)-CH(2) groups are almost coplanar, with an r.m.s. deviation of 0.030 Å. The aromatic rings are approximately perpendicular to each other, forming a dihedral angle of 78.31 sh;H⋯O hydrogen bonds and C-H⋯π inter-actions help to consolidate the three-dimensional network.

Reverse trends of TEX86 temperature in coastal areas of the East China Sea over the last 100 years: implication for global warming and regional circulation

NASA Astrophysics Data System (ADS)

Cao, Y.; Xing, L.; Zhang, T.

2017-12-01

To reconstruct and compare the SST changes in different regions of the ECS over the last 100 years, in this study, we analyzed iGDGTs compounds and TEX86 index in two sediment cores (DH5-1 and DH6-2) from the inner shelf of the East China Sea (ECS). GDGT-0 and GDGT-5 in the two cores account for 80% of iGDGTs, significantly more abundant than the other iGDGTs compounds. It is also found that iGDGTs are mainly derived from marine Thaumarchaeota. TEXH86 temperatures varied from 17 °C to 22 °C (average 19.4 °C), showing a gradual increase in Core DH5-1 near the Changjiang River Estuary, corresponding to global warming and temperature rise in the ECS over the last 100 years. However, in Core DH6-2 further away from the Changjiang River Estuary, TEXH86 temperatures gradually decreased over the last 80 years with a range of 15.3 °C-18.3 °C, which is attributed to the strengthened near-shore Kuroshio Branch Current transporting more subsurface cold water to the ECS coastal area. In future, more sites should be investigated to confirm the range of the coastal area where the decrease in SST is caused by upwelling subsurface water.

Extraction of cesium and strontium from nuclear waste

DOEpatents

Davis, Jr., Milton W.; Bowers, Jr., Charles B.

1988-01-01

Cesium is extracted from acidified nuclear waste by contacting the waste with a bis 4,4'(5) [1-hydroxy-2-ethylhexyl]benzo 18-crown-6 compound and a cation exchanger in a matrix solution. Strontium is extracted from acidified nuclear waste by contacting the waste with a bis 4,4'(5') [1-hydroxyheptyl]cyclohexo 18-crown-6 compound, and a cation exchanger in a matrix solution.

Synthesis and Preclinical Evaluation of Three Novel Fluorine-18 Labeled Radiopharmaceuticals for P-Glycoprotein PET Imaging at the Blood-Brain Barrier.

PubMed

Savolainen, Heli; Cantore, Mariangela; Colabufo, Nicola A; Elsinga, Philip H; Windhorst, Albert D; Luurtsema, Gert

2015-07-06

P-Glycoprotein (P-gp), along with other transporter proteins at the blood-brain barrier (BBB), limits the entry of many pharmaceuticals into the brain. Altered P-gp function has been found in several neurological diseases. To study the P-gp function, many positron emission tomography (PET) radiopharmaceuticals have been developed. Most P-gp radiopharmaceuticals are labeled with carbon-11, while labeling with fluorine-18 would increase their applicability due to longer half-life. Here we present the synthesis and in vivo evaluation of three novel fluorine-18 labeled radiopharmaceuticals: 4-((6,7-dimethoxy-3,4-dihydroisoquinolin-2(1H)-yl)methyl)-2-(4-fluorophenyl)oxazole (1a), 2-biphenyl-4-yl-2-fluoroethoxy-6,7-dimethoxy-1,2,3,4-tetrahydro-isoquinoline (2), and 5-(1-(2-fluoroethoxy))-[3-(6,7-dimethoxy-3,4-dihydro-1H-isoquinolin-2-yl)-propyl]-5,6,7,8-tetrahydronaphthalen (3). Compounds were characterized as P-gp substrates in vitro, and Mdr1a/b((-/-))Bcrp1((-/-)) and wild-type mice were used to assess the substrate potential in vivo. Comparison was made to (R)-[(11)C]verapamil, which is currently the most frequently used P-gp substrate. Compound [(18)F]3 was performing the best out of the new radiopharmaceuticals; it had 2-fold higher brain uptake in the Mdr1a/b((-/-))Bcrp1((-/-)) mice compared to wild-type and was metabolically quite stable. In the plasma, 69% of the parent compound was intact after 45 min and 96% in the brain. Selectivity of [(18)F]3 to P-gp was tested by comparing the uptake in Mdr1a/b((-/-)) mice to uptake in Mdr1a/b((-/-))Bcrp1((-/-)) mice, which was statistically not significantly different. Hence, [(18)F]3 was found to be selective for P-gp and is a promising new radiopharmaceutical for P-gp PET imaging at the BBB.

Chemical constituents from the stems of Gymnema sylvestre.

PubMed

Liu, Yue; Xu, Tun-Hai; Zhang, Man-Qi; Li, Xue; Xu, Ya-Juan; Jiang, Hong-Yu; Liu, Tong-Hua; Xu, Dong-Ming

2014-04-01

To study the chemical constituents of stems of Gymnema sylvestre (Retz.) Schult. Chromatographic techniques using silica gel, C18 reversed phase silica gel, and prep-HPLC were used. The structures were elucidated on the basis of MS and spectroscopic analysis (1D and 2D NMR), as well as chemical methods. Seven compounds were isolated and their structures were elucidated as conduritol A (1), stigmasterol (2), lupeol (3), stigmasterol-3-O-β-D-glucoside (4), the sodium salt of 22α-hydroxy-longispinogenin-3-O-β-D-glucopyranosyl-(1→3)-β-D-glu-curono-pyranosyl-28-O-α-L-rhamnopyranoside (5), oleanolic acid-3-O-β-D-glucopyranosyl-(1→6)-β-D-glucopyranoside (6), and the sodium salt of 22α-hydroxy-longispinogenin 3-O-β-D-glucuronopyranosyl-28-O-α-L-rhamnopyranoside (7). The inhibition activities of compounds 1, 5-7 on non-enzymatic glycation of protein in vitro were evaluated. Compound 7 is a new triterpenoid saponin. It was shown that compounds 1, 5-7 have weak inhibition activities for non-enzymatic glycation of protein in vitro. Copyright © 2014 China Pharmaceutical University. Published by Elsevier B.V. All rights reserved.

Fast and simultaneous determination of phenolic compounds and caffeine in teas, mate, instant coffee, soft drink and energetic drink by high-performance liquid chromatography using a fused-core column.

PubMed

Rostagno, M A; Manchón, N; D'Arrigo, M; Guillamón, E; Villares, A; García-Lafuente, A; Ramos, A; Martínez, J A

2011-01-31

A fast HPLC method with diode-array absorbance detector and fluorescence detector for the analysis of 19 phenolic acids, flavan-3-ols, flavones, flavonols and caffeine in different types of samples was developed. Using a C(18) reverse-phase fused-core column separation of all compounds was achieved in less than 5 min with an overall sample-to-sample time of 10 min. Evaluation of chromatographic performance revealed excellent reproducibility, resolution, selectivity and peak symmetry. Limits of detection for all analyzed compounds ranged from 0.5 to 211 μg L(-1), while limits of quantitation ranged between 1.5 and 704 μg L(-1). The developed method was used for the determination of analytes present in different samples, including teas (black, white, green), mate, coffee, cola soft drink and an energetic drink. Concentration of the analyzed compounds occurring in the samples ranged from 0.4 to 314 mg L(-1). Caffeine was the analyte found in higher concentrations in all samples. Phytochemical profiles of the samples were consistent with those reported in the literature. Copyright © 2010 Elsevier B.V. All rights reserved.

Preparation and characterization of phosphine-tetraborane(8)

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

Jock, C.P.; Kodama, G.

1988-09-21

The preparation of B/sub 4/H/sub 8/ x PH/sub 3/ by cleaving pentaborane, B/sub 5/H/sub 11/, with PH/sub 3/ is reported herein. The formation of a reaction intermediate, B/sub 5/H/sub 11/ x PH/sub 3/, which decomposes above -80/degrees/C in dichloromethane, is also reported. The /sup 11/B NMR spectrum of B/sub 4/H/sub 8/ x PH/sub 3/ indicates that the compound exists in two isomeric forms, endo and exo forms. 18 references, 3 figures, 1 table.

The evaporation study of silicon-containing ionic liquid

NASA Astrophysics Data System (ADS)

Chilingarov, Norbert S.; Medvedev, Artem A.; Deyko, Grigoriy S.; Kustov, Leonid M.; Chernikova, Elena A.; Glukhov, Lev M.; Polyakova, Marina V.; Ioutsi, Vitaliy A.; Markov, Vitaliy Yu.; Sidorov, Lev N.

2016-07-01

1,2-Dimethyl-3-(1‧,1‧,3‧,3‧-tetramethyl-3‧-phenyldisiloxanyl)methylimidazolium bis(trifluoromethanesulfonyl)amide ([PhC5OSi2MMIm+][Tf2N-]) is the first silicon-containing ionic liquid which was characterized with the vaporization enthalpy, (138.5 ± 1.8) kJ mol-1, and saturated vapor pressure, ln(p/Pa) = -(16656 ± 219)/(T/K) + (30.69 ± 0.92). This compound is a unique ionic liquid giving ions, retaining both cationic and anionic portions, in the electron impact ionization (EI) mass spectrum.

Stability of Cholesterol, 7-Ketocholesterol and β-Sitosterol during Saponification: Ramifications for Artifact Monitoring of Sterol Oxide Products.

PubMed

Busch, T P; King, A J

2010-09-01

Cholesterol has been used to monitor artifact generation. Stability differences among cholesterol oxide products (COPs) and cholesterol in thermal and alkaline conditions are theorized. Thus, use of cholesterol may be unsuitable for detection of artifacts generated from COPs. Stability of cholesterol was compared to that of 7-ketocholesterol (7-keto) and β-sitosterol (βS) under various thermal and alkaline saponification conditions: 1 M methanolic KOH for 18 h at 24 °C (1 M18hr24°C, Control), 18 h at 37 °C (1M18hr37°C), 3 h at 45 °C (1M3hr45°C), and 3.6 M methanolic KOH for 3 h at 24 °C (3.6M3hr24°C). Trends indicated that cholesterol in solution was more stable than 7-keto under all conditions. Compared to βS, cholesterol was more stable under all conditions except for 1M18hr37°C for which stabilities were similar. Compounds were more labile in heat than alkalinity. Poor recoveries of 7-keto during cold saponification with high alkalinity were attributed to alkaline instability. 7-Keto, less stable than cholesterol, should be used to monitor artifact generation during screening of various methods that include thermal and alkaline conditions. In a preliminary analysis of turkey meat, more 3,5-7-one was generated from spiking with cholesterol than with 7-keto.

Stability of Cholesterol, 7-Ketocholesterol and β-Sitosterol during Saponification: Ramifications for Artifact Monitoring of Sterol Oxide Products

PubMed Central

Busch, T. P.

2010-01-01

Cholesterol has been used to monitor artifact generation. Stability differences among cholesterol oxide products (COPs) and cholesterol in thermal and alkaline conditions are theorized. Thus, use of cholesterol may be unsuitable for detection of artifacts generated from COPs. Stability of cholesterol was compared to that of 7-ketocholesterol (7-keto) and β-sitosterol (βS) under various thermal and alkaline saponification conditions: 1 M methanolic KOH for 18 h at 24 °C (1 M18hr24°C, Control), 18 h at 37 °C (1M18hr37°C), 3 h at 45 °C (1M3hr45°C), and 3.6 M methanolic KOH for 3 h at 24 °C (3.6M3hr24°C). Trends indicated that cholesterol in solution was more stable than 7-keto under all conditions. Compared to βS, cholesterol was more stable under all conditions except for 1M18hr37°C for which stabilities were similar. Compounds were more labile in heat than alkalinity. Poor recoveries of 7-keto during cold saponification with high alkalinity were attributed to alkaline instability. 7-Keto, less stable than cholesterol, should be used to monitor artifact generation during screening of various methods that include thermal and alkaline conditions. In a preliminary analysis of turkey meat, more 3,5-7-one was generated from spiking with cholesterol than with 7-keto. PMID:20835297

Radiation damage and thermal shock response of carbon-fiber-reinforced materials to intense high-energy proton beams

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

Simos, N.; Zhong, Z.; Ghose, S.

Here, a comprehensive study on the effects of energetic protons on carbon-fiber composites and compounds under consideration for use as low-Z pion production targets in future high-power accelerators and low-impedance collimating elements for intercepting TeV-level protons at the Large Hadron Collider has been undertaken addressing two key areas, namely, thermal shock absorption and resistance to irradiation damage. Carbon-fiber composites of various fiber weaves have been widely used in aerospace industries due to their unique combination of high temperature stability, low density, and high strength. The performance of carbon-carbon composites and compounds under intense proton beams and long-term irradiation have beenmore » studied in a series of experiments and compared with the performance of graphite. The 24-GeV proton beam experiments confirmed the inherent ability of a 3D C/C fiber composite to withstand a thermal shock. A series of irradiation damage campaigns explored the response of different C/C structures as a function of the proton fluence and irradiating environment. Radiolytic oxidation resulting from the interaction of oxygen molecules, the result of beam-induced radiolysis encountered during some of the irradiation campaigns, with carbon atoms during irradiation with the presence of a water coolant emerged as a dominant contributor to the observed structural integrity loss at proton fluences ≥5×10 20 p/cm 2. The carbon-fiber composites were shown to exhibit significant anisotropy in their dimensional stability driven by the fiber weave and the microstructural behavior of the fiber and carbon matrix accompanied by the presence of manufacturing porosity and defects. Carbon-fiber-reinforced molybdenum-graphite compounds (MoGRCF) selected for their impedance properties in the Large Hadron Collider beam collimation exhibited significant decrease in postirradiation load-displacement behavior even after low dose levels (~5×10 18 p cm -2). In addition, the studied MoGRCF compound grade suffered a high degree of structural degradation while being irradiated in a vacuum after a fluence ~5×10 20 p cm -2. Finally, x-ray diffraction studies on irradiated C/C composites and a carbon-fiber-reinforced Mo-graphite compound revealed (a) low graphitization in the “as-received” 3D C/C and high graphitization in the MoGRCF compound, (b) irradiation-induced graphitization of the least crystallized phases in the carbon fibers of the 2D and 3D C/C composites, (c) increased interplanar distances along the c axis of the graphite crystal with increasing fluence, and (d) coalescence of interstitial clusters after irradiation forming new crystalline planes between basal planes and excellent agreement with fast neutron irradiation effects.« less

Radiation damage and thermal shock response of carbon-fiber-reinforced materials to intense high-energy proton beams

DOE PAGES

Simos, N.; Zhong, Z.; Ghose, S.; ...

2016-11-16

Here, a comprehensive study on the effects of energetic protons on carbon-fiber composites and compounds under consideration for use as low-Z pion production targets in future high-power accelerators and low-impedance collimating elements for intercepting TeV-level protons at the Large Hadron Collider has been undertaken addressing two key areas, namely, thermal shock absorption and resistance to irradiation damage. Carbon-fiber composites of various fiber weaves have been widely used in aerospace industries due to their unique combination of high temperature stability, low density, and high strength. The performance of carbon-carbon composites and compounds under intense proton beams and long-term irradiation have beenmore » studied in a series of experiments and compared with the performance of graphite. The 24-GeV proton beam experiments confirmed the inherent ability of a 3D C/C fiber composite to withstand a thermal shock. A series of irradiation damage campaigns explored the response of different C/C structures as a function of the proton fluence and irradiating environment. Radiolytic oxidation resulting from the interaction of oxygen molecules, the result of beam-induced radiolysis encountered during some of the irradiation campaigns, with carbon atoms during irradiation with the presence of a water coolant emerged as a dominant contributor to the observed structural integrity loss at proton fluences ≥5×10 20 p/cm 2. The carbon-fiber composites were shown to exhibit significant anisotropy in their dimensional stability driven by the fiber weave and the microstructural behavior of the fiber and carbon matrix accompanied by the presence of manufacturing porosity and defects. Carbon-fiber-reinforced molybdenum-graphite compounds (MoGRCF) selected for their impedance properties in the Large Hadron Collider beam collimation exhibited significant decrease in postirradiation load-displacement behavior even after low dose levels (~5×10 18 p cm -2). In addition, the studied MoGRCF compound grade suffered a high degree of structural degradation while being irradiated in a vacuum after a fluence ~5×10 20 p cm -2. Finally, x-ray diffraction studies on irradiated C/C composites and a carbon-fiber-reinforced Mo-graphite compound revealed (a) low graphitization in the “as-received” 3D C/C and high graphitization in the MoGRCF compound, (b) irradiation-induced graphitization of the least crystallized phases in the carbon fibers of the 2D and 3D C/C composites, (c) increased interplanar distances along the c axis of the graphite crystal with increasing fluence, and (d) coalescence of interstitial clusters after irradiation forming new crystalline planes between basal planes and excellent agreement with fast neutron irradiation effects.« less

Maize opaque5 Encodes Monogalactosyldiacylglycerol Synthase and Specifically Affects Galactolipids Necessary for Amyloplast and Chloroplast Function[C][W][OA

PubMed Central

Myers, Alan M.; James, Martha G.; Lin, Qiaohui; Yi, Gibum; Stinard, Philip S.; Hennen-Bierwagen, Tracie A.; Becraft, Philip W.

2011-01-01

The maize (Zea mays) opaque5 (o5) locus was shown to encode the monogalactosyldiacylglycerol synthase MGD1. Null and point mutations of o5 that affect the vitreous nature of mature endosperm engendered an allelic series of lines with stepwise reductions in gene function. C18:3/C18:2 galactolipid abundance in seedling leaves was reduced proportionally, without significant effects on total galactolipid content. This alteration in polar lipid composition disrupted the organization of thylakoid membranes into granal stacks. Total galactolipid abundance in endosperm was strongly reduced in o5- mutants, causing developmental defects and changes in starch production such that the normal simple granules were replaced with compound granules separated by amyloplast membrane. Complete loss of MGD1 function in a null mutant caused kernel lethality owing to failure in both endosperm and embryo development. The data demonstrate that low-abundance galactolipids with five double bonds serve functions in plastid membranes that are not replaced by the predominant species with six double bonds. Furthermore, the data identify a function of amyloplast membranes in the development of starch granules. Finally, the specific changes in lipid composition suggest that MGD1 can distinguish the constituency of acyl groups on its diacylglycerol substrate based upon the degree of desaturation. PMID:21685260

Cytotoxic pregnane steroids from the seeds of Cipadessa baccifera (Roth.) Miq.

PubMed

Zhao, Lei; Zhang, Ping; Su, Xiao-Jie; Zhang, Bing

2017-03-01

A chemical investigation of the 80% ethanol extract of the seeds of Cipadessa baccifera (Roth.) Miq. led to the isolation of five new pregnane steroids, 17α,18,20S-trihydroxy-pregn-4-en-3,16-dione (1), 18-hydoxy-pregn-4,17(20)-trans-dien-3,16-dione (2), 3β,18-dihydroxy-pregn-5,17(20)-trans-dien-16-one (3), 2α,3β,4β,18-tetrahydroxy-pregn-5,17(20)-trans-dien-16-one (4), and 2α,3β,4β,17α,18,20S-hexahydroxy-pregn-5-en-16-one (5), along with two known compounds, 17α,20S-dihydroxy-pregn-4-en-3,16-dione (6) and 3β-hydroxy-pregn-5,17-dien-16-one (7). Structural elucidation of all the compounds was accomplished by spectral methods such as 1D and 2D NMR, IR, UV, and HRESIMS. The isolated compounds were tested in vitro for cytotoxic activities against seven tumor cell lines. As a result, pregnane-type steroids 1, 5 and 6 exhibited cytotoxicity with IC 50 values <20μM against all tested tumor cell lines except meningioma cells (BEN-MEN-1). Copyright © 2017 Elsevier B.V. All rights reserved.

High throughput screening of active pharmaceutical ingredients by UPLC.

PubMed

Al-Sayah, Mohammad A; Rizos, Panagiota; Antonucci, Vincent; Wu, Naijun

2008-07-01

Ultra performance LC (UPLC) was evaluated as an efficient screening approach to facilitate method development for drug candidates. Three stationary phases were screened: C-18, phenyl, and Shield RP 18 with column dimensions of 150 mm x 2.1 mm, 1.7 microm, which should theoretically generate 35,000 plates or 175% of the typical column plate count of a conventional 250 mm x 4.6 mm, 5 microm particle column. Thirteen different active pharmaceutical ingredients (APIs) were screened using this column set with a standardized mobile-phase gradient. The UPLC method selectivity results were compared to those obtained for these compounds via methods developed through laborious trial and error screening experiments using numerous conventional HPLC mobile and stationary phases. Peak capacity was compared for columns packed with 5 microm particles and columns packed with 1.7 microm particles. The impurities screened by UPLC were confirmed by LC/MS. The results demonstrate that simple, high efficiency UPLC gradients are a feasible and productive alternative to more conventional multiparametric chromatographic screening approaches for many compounds in the early stages of drug development.

Cytotoxic and genotoxic potential of drinking water: a comparison between two different concentration methods.

PubMed

Buschini, Annamaria; Giordani, Federica; Pellacani, Claudia; Rossi, Carlo; Poli, Paola

2008-04-01

The level of exposure to hazardous compounds through drinking water is low but it is maintained throughout life, therefore representing a risk factor for human health. The use of techniques averaging the consumer's exposure over time could be more useful than relying on intermittent grab samples that may misrepresent average tap water concentrations due to short-term temporal variability. In this study, we compared the induction of in vitro cytotoxic and genotoxic effects (DNA damage by the comet assay) in relation to different sampling methods, i.e. exposure over time (semipermeable membrane devices, SPMDs, exposed for 30 days) or intermittent grab samples (5 weekly water sampling, C18 concentration). Waters with different chemical characteristics were sampled to test the sensitivity of the two methods. We did not found any positive correlation between the biological findings and water chemical parameters. SPMD extracts induced a significantly greater DNA damage than C18. The different behaviour was specially found for the water samples with a low level of organic compounds and when C18 extracts were highly cytotoxic. Our findings suggest that SPMD could be of a great interest in assessing genotoxic contaminants in both raw and drinking water, with great suitability for continuous monitoring. Furthermore, the results of this study have confirmed the great importance of the biological assays in evaluating the effects of a complex mixture such as water in addition to the conventional chemical examination of water quality.

Characterization of Extractable Organic Fine Particulate Matter in the Atmosphere of Houston and Source Apportionment Calculations Using Organic Molecular Markers

NASA Astrophysics Data System (ADS)

Fraser, M. P.; Yue, Z. W.; Buzco, B.

2002-12-01

Samples of atmospheric PM2.5 were collected in Houston, TX every second day during the summer of 2000 as part of the EPA sponsored Houston Fine Particle Matter Supersite program. Sampling occurred at three sites, including one industrial location (HRM-3), one suburban location (Aldine) and one coastal location (La Porte). Twenty samples collected over a 24 hour period have been analyzed to quantify the concentration of 95 individual organic compounds, including: n-alkanes (C20 to C36), aromatic hydrocarbons (PAHs), n-alkanoic acids (C5 to C34), n-alkenoic acids (C18:1 and C18:2), carboxylic diacids (C3 to C10), petroleum biomarkers and others. As a whole, the extractable compounds were dominated by acids, especially by octadecanoic acid and hexadecanoic acid. The measured concentration of n-alkanes exhibited a peak at C29, with carbon preference index (CPI) values in the range of 0.97 to 2.0. Using organic molecular markers, including seven alkanes, four petroleum biomarkers, seven PAH, one alkanoic acid, one alkenoic acid, levoglucosan, and three chemical components (Al, Si and Elemental Carbon), Chemical Mass Balancing (CMB) calculations have been performed on the ambient speciation data. These calculations are used to determine the contribution of seven different primary emission sources including: diesel powered vehicles, gasoline vehicles, wood combustion, fuel oil combustion, road dusts, meat cooking and vegetation waxes. The contribution of diesel powered vehicles and gasoline powered vehicles are the most important primary sources at all three sampling locations, with road dusts important at the industrial location. Meat cooking emissions were significant at all three locations. Wood combustion is an important contribution during a four-day period when uncontrolled wildfires in eastern Texas and Louisiana brought biomass combustion aerosols into the sampling region.

Synthesis, structure and research on quasi-aromaticity of a new organically templated aluminoborate: [NH0.5C4H4NH0.5][AlB12O14(OH)12

NASA Astrophysics Data System (ADS)

Hu, HengBin; Chen, XiangYi; Deng, Song; Cai, Feng; Sun, YanQiong; Chen, YiPing

2012-02-01

By employing hydrothermal method, we identify a new organically templated aluminoborate [NH0.5C4H4NH0.5][AlB12O14(OH)12] which is structurally determined by single crystal X-ray diffraction and characterized by simulated and experimental IR, 2D IR COS (two-dimensional infrared correlation spectroscopy), NICS (nucleus-independent chemical shifts) and Mulliken charges calculations. Although the cluster anions [AlB12O14(OH)12]- is identical to the counterpart of compound reported by Lin et al. at 2008, we firstly bring up its quasi-aromaticity, discuss and confirm it by NICS, Mulliken charges calculations and magnetic-induced 2D IR COS, and conclude that three isolated and non-coplanar four-center six-electron π bonds of cluster could cooperate and interact with each other to form a closed conjugated large π orbital system, endowing the cluster anions with quasi-aromaticity. Thus, a one-dimensional chain is constructed by π-π stacked interaction between quasi-aromatic clusters and aromatic pyrazine along [1 0¯ 1] direction. The title compound crystallizes in monoclinic space group C2/c with a = 18.397(4), b = 12.0670(16), c = 11.075(2) Å, α = 90.00, β = 116.483(11), γ = 90.00°, Z = 4, V = 2200.6(7) Å, R = 0.0442 and wR = 0.1128 for 2689 observed reflections.

Crystal structure, phytochemical study and enzyme inhibition activity of Ajaconine and Delectinine

NASA Astrophysics Data System (ADS)

Ahmad, Shujaat; Ahmad, Hanif; Khan, Hidayat Ullah; Shahzad, Adnan; Khan, Ezzat; Ali Shah, Syed Adnan; Ali, Mumtaz; Wadud, Abdul; Ghufran, Mehreen; Naz, Humera; Ahmad, Manzoor

2016-11-01

The Crystal structure, comparative DFT study and phytochemical investigation of atisine type C-20 diterpenoid alkaloid ajaconine (1) and lycoctonine type C-19 diterpenoid alkaloid delectinine (2) is reported here. These compounds were isolated from Delphinium chitralense. Both the natural products 1 and 2 crystallize in orthorhombic crystal system with identical space group of P212121. The geometric parameters of both compounds were calculated with the help of DFT using B3LYP/6-31+G (p) basis set and HOMO-LUMO energies, optimized band gaps, global hardness, ionization potential, electron affinity and global electrophilicity are calculated. The compounds 1 and 2 were screened for acetyl cholinesterase and butyryl cholinesterase inhibition activities in a dose dependent manner followed by molecular docking to explore the possible inhibitory mechanism of ajaconine (1) and delectinine (2). The IC50 values of tested compounds against AChE were observed as 12.61 μM (compound 1) and 5.04 μM (compound 2). The same experiments were performed for inhibition of BChE and IC50 was observed to be 10.18 μM (1) and 9.21 μM (2). Promising inhibition activity was shown by both the compounds against AChE and BChE in comparison with standard drugs available in the market such as allanzanthane and galanthamine. The inhibition efficiency of both the natural products was determined in a dose dependent manner.

ABCC6 Gene Analysis in 20 Japanese Patients with Angioid Streaks Revealing Four Frequent and Two Novel Variants and Pseudodominant Inheritance

PubMed Central

Negishi, Yuya; Mizobuchi, Kei; Urashima, Mitsuyoshi; Nakano, Tadashi

2017-01-01

Purpose To report the spectrum of ABCC6 variants in Japanese patients with angioid streaks (AS). Patients and Methods This was a single-center cohort study. The medical records of 20 patients with AS from 18 unrelated Japanese families were retrospectively reviewed. Screening of the ABCC6 gene (exons 1 to 31) was performed using PCR-based Sanger sequencing. Results Eight ABCC6 variants were identified as candidate disease-causing variants. These eight variants included five known variants (p.Q378X, p.R419Q, p.V848CfsX83, p.R1114C, and p.R1357W), one previously reported variant (p.N428S) of unknown significance, and two novel variants (c.1939C>T [p.H647Y] and c.3374C>T [p.S1125F]); the three latter variants were determined to be variants of significance. The following four variants were frequently identified: p.V848CfsX83 (14/40 alleles, 35.0%), p.Q378X (7/40 alleles, 17.5%), p.R1357W (6/40 alleles, 15.0%), and p.R419Q (4/40 alleles, 10.0%). The ABCC6 variants were identified in compound heterozygous or homozygous states in 13 of 18 probands. Two families showed a pseudodominant inheritance pattern. Pseudoxanthoma elasticum was seen in 15 of 17 patients (88.2%) who underwent dermatological examination. Conclusions We identified disease-causing ABCC6 variants that were in homozygous or compound heterozygous states in 13 of 18 families (72.2%). Our results indicated that ABCC6 variants play a significant role in patients with AS in the Japanese population. PMID:28912966

[One new chroman glycoside derivative from unmatured fruits of Citrus aurantium].

PubMed

Peng, Wen-Wen; Yan, He; Tan, Ning-Hua

2013-01-01

To study the chemical constituents of the unmatured fruits of Citrus aurantium. The AcOEt fraction of the methanol extracts of the unmatured fruits of C. aurantium were subjected on column chromatographies including silica gel, RP-18 and HPLC. Compound structures isolated were determined on the basis of spectroscopic data. Three compounds were isolated from the unmatured fruits of C. aurantium, which were identified as citrauranoside (1), limonexin (2) and limonin (3). Compound 1 is a new chroman glycoside derivative, named as citrauranoside.

Fluoralkenyl nortropanes

DOEpatents

Goodman, Mark M.; Chen, Ping

2002-02-05

Provided are compounds of the following formula: ##STR1## wherein R is C2-C6 mono- or multi-unsaturated hydrocarbon having one or more ethylene, acetylene or allene groups, A is 18 or 19, and X is H or halogen. The compounds of the invention bind to dopamine transporter with high affinity and selectivity and are thus useful as diagnostic and therapeutic agents for diseases associated with dopamine transporter dysfunction. The radiolabeled compounds are useful as imaging agents for visualizing the location and density of dopamine transporter by PET imaging.

N-(2-Allyl-4-chloro-2H-indazol-5-yl)-4-meth-oxy-benzene-sulfonamide hemi-hydrate.

PubMed

Chicha, Hakima; Kouakou, Assoman; Rakib, El Mostapha; Saadi, Mohamed; El Ammari, Lahcen

2013-01-01

The fused five- and six-membered rings in the title compound, C17H16ClN3O3S·0.5H2O, are practically coplanar, with the maximum deviation from the mean plane being 0.057 (3) Å for the C atom bound to the exocyclic N atom. The indazole system makes a dihedral angle of 66.18 (12)° with the plane through the benzene ring, and it is nearly perpendicular to the allyl group, as indicated by the N-N-C-C torsion angle of 79.2 (3)°. In the crystal, the water mol-ecule, lying on a twofold axis, forms O-H⋯N and accepts N-H⋯O hydrogen bonds. Additional C-H⋯O hydrogen bonds contribute to the formation of a chain along the b-axis direction.

Development and validation of an LC-UV method for the quantification and purity determination of the novel anticancer agent C1311 and its pharmaceutical dosage form.

PubMed

den Brok, Monique W J; Nuijen, Bastiaan; Hillebrand, Michel J X; Grieshaber, Charles K; Harvey, Michael D; Beijnen, Jos H

2005-09-01

C1311 (5-[[2-(diethylamino)ethyl]amino]-8-hydroxyimidazo [4,5,1-de]-acridin-6-one-dihydrochloride trihydrate) is the lead compound from the group of imidazoacridinones, a novel group of rationally designed anticancer agents. The pharmaceutical development of C1311 necessitated the availability of an assay for the quantification and purity determination of C1311 active pharmaceutical ingredient (API) and its pharmaceutical dosage form. A reversed-phase liquid chromatographic method (RP-LC) with ultraviolet (UV) detection was developed, consisting of separation on a C18 column with phosphate buffer (60 mM; pH 3 with 1 M citric acid)-acetonitrile-triethylamine (83:17:0.05, v/v/v) as the mobile phase and UV-detection at 280 nm. The method was found to be linear over a concentration range of 2.50-100 microg/mL, precise and accurate. Accelerated stress testing showed degradation products, which were well separated from the parent compound, confirming its stability-indicating capacity. Moreover, the use of LC-MS and on-line photo diode array detection enabled us to propose structures for four degradation products. Two of these products were also found as impurities in the API and more abundantly in an impure lot of API.

Speciation of inorganic and organolead compounds by gas chromatography-atomic absorption spectrometry and the determination of lead species after pre-concentration onto diphenylthiocarbazone-anchored polymeric microbeads

NASA Astrophysics Data System (ADS)

Salih, Bekir

2000-07-01

Poly(EGDMA-HEMA) microbeads were prepared by suspension copolymerization of ethyleneglycol dimethacrylate (EGDMA) and hydroxyethylmethacrylate (HEMA) using poly(vinylalcohol), benzoyl peroxide and toluene as the stabilizer, the initiator, and the diluent, respectively. A chelating ligand, diphenylthiocarbazone (dithizone), was then attached. The microbeads were characterized by FT-IR and elemental analysis. The affinity microbeads containing 118.9 μmol dithizone g -1 polymer were used in the adsorption/desorption of some selected lead species, Pb(II), (CH 3) 2PbCl 2, (C 2H 5) 2PbCl 2, (CH 3) 3PbCl, and (C 2H 5) 3PbCl from aqueous media containing different amounts of these species (5-200 mg l -1) at different pH values, 2.0-8.0. Adsorption rates were high, and adsorption equilibrium was reached in approximately 45 min. The detection limits of the lead species onto the dithizone-anchored affinity microbeads from solutions containing a single species was 0.28 ng ml -1 for Pb(II), 0.12 ng ml -1 for (CH 3) 3PbCl, 0.24 ng ml -1 for (C 2H 5) 3PbCl, 0.18 ng ml -1 for (CH 3) 2PbCl 2 and 0.30 ng ml -1 for (C 2H 5) 2PbCl 2 on a weight basis for lead. The same behavior was observed during competitive adsorption that is adsorption from a mixture. The affinity order of the lead species was Pb(II)>(CH 3) 2PbCl 2>(CH 3) 3PbCl>(C 2H 5) 3PbCl>(C 2H 5) 2PbCl 2 for competitive adsorption. Dithizone-anchored microbeads were found to be suitable for repeated use of more than five cycles, without noticeable loss of adsorption capacity. For the speciation of organolead compounds, ionic alkyllead compounds were derivatized by n-butyl Grignard reagent and the speciation was performed using a gas chromatography-atomic absorption spectrometry coupled system. Detection limits were improved at least 180-fold with this preconcentration approach using the dithizone-anchored microbeads.

Simultaneous screening for 238 drugs in blood by liquid chromatography-ion spray tandem mass spectrometry with multiple-reaction monitoring.

PubMed

Gergov, M; Ojanperä, I; Vuori, E

2003-09-25

A liquid chromatography-tandem mass spectrometry (LC-MS-MS) method is presented for the qualitative screening for 238 drugs in blood samples, which is considerably more than in previous methods. After a two-step liquid-liquid extraction and C(18) chromatography, the compounds were introduced into a triple quadrupole mass spectrometer equipped with a turbo ion spray ion source operating in the positive ionization mode. Identification was based on the compound's absolute retention time, protonated molecular ion, and one representative fragment ion obtained by multiple reaction monitoring (MRM) at an individually selected collision energy of 20, 35, or 50 eV. The limit of detection (LOD) for the majority of the compounds (80%) was < or = 0.05 mg/l, ranging from 0.002 mg/l (e.g., antihistamines) to 5 mg/l (acidic compounds), and for malathion it was 10 mg/l. The LOD values were sufficiently low to allow the majority of compounds to be detected at therapeutic concentrations in the blood.

2,3,5-Substituted tetrahydrofurans: COX-2 inhibitory activities of 5-hydroxymethyl-/carboxyl-2,3-diaryl-tetrahydro-furan-3-ols.

PubMed

Singh, Palwinder; Mittal, Anu; Kaur, Satwinderjeet; Kumar, Subodh

2008-12-01

5-Hydroxymethyl-/carboxyl-2,3-diaryl-tetrahydro-furan-3-ols have been investigated for their COX-1 and COX-2 inhibitory activities. Compounds 17, 18 and 20 have been identified as showing appreciable COX-2 inhibition and selectivity. The group present at C-5 of tetrahydrofuran and the substituents at the two phenyl rings, through their interactions with active site amino acid residues, significantly affect the activities of these molecules. The quantitative structure-activity relationship studies indicate the role of logP, TPSA, molecular connectivity and valence connectivity towards the activities of these molecules.

Antifeedant effect of polygodial and drimenol derivatives against Spodoptera frugiperda and Epilachna paenulata and quantitative structure-activity analysis.

PubMed

Montenegro, Iván J; Del Corral, Soledad; Diaz Napal, Georgina N; Carpinella, María C; Mellado, Marco; Madrid, Alejandro M; Villena, Joan; Palacios, Sara M; Cuellar, Mauricio A

2018-07-01

The antifeedant activity of 18 sesquiterpenoids of the drimane family (polygodial, drimenol and derivatives) was investigated. Polygodial, drimanic and nordrimanic derivatives were found to exert antifeedant effects against two insect species, Spodoptera frugiperda and Epilachna paenulata, which are pests of agronomic interest, indicating that they have potential as biopesticide agents. Among the 18 compounds tested, the epoxynordrimane compound (11) and isonordrimenone (4) showed the highest activity [50% effective concentration (EC 50 ) = 23.28 and 25.63 nmol cm - 2 , respectively, against S. frugiperda, and 50.50 and 59.00 nmol/cm 2 , respectively, against E. paenulata]. The results suggest that drimanic compounds have potential as new agents against S. frugiperda and E. paenulata. A quantitative structure-activity relationship (QSAR) analysis of the whole series, supported by electronic studies, suggested that drimanic compounds have structural features necessary for increasing antifeedant activity, namely a C-9 carbonyl group and an epoxide at C-8 and C-9. © 2018 Society of Chemical Industry. © 2018 Society of Chemical Industry.

Commercial squids: characterization, assessment of potential health benefits/risks and discrimination based on mineral, lipid and vitamin E concentrations.

PubMed

Torrinha, A; Gomes, F; Oliveira, M; Cruz, R; Mendes, E; Delerue-Matos, C; Casal, S; Morais, S

2014-05-01

The most consumed squid species worldwide were characterized regarding their concentrations of minerals, fatty acids, cholesterol and vitamin E. Interspecific comparisons were assessed among species and geographical origin. The health benefits derived from squid consumption were assessed based on daily minerals intake and on nutritional lipid quality indexes. Squids contribute significantly to daily intake of several macro (Na, K, Mg and P) and micronutrients (Cu, Zn and Ni). Despite their low fat concentration, they are rich in long-chain omega-3 fatty acids, particularly docosahexaenoic (DHA) and eicosapentanoic (EPA) acids, with highly favorable ω-3/ω-6 ratios (from 5.7 to 17.7), reducing the significance of their high cholesterol concentration (140-549 mg/100g ww). Assessment of potential health risks based on minerals intake, non-carcinogenic and carcinogenic risks indicated that Loligo gahi (from Atlantic Ocean), Loligo opalescens (from Pacific Ocean) and Loligo duvaucelii (from Indic Ocean) should be eaten with moderation due to the high concentrations of Cu and/or Cd. Canonical discriminant analysis identified the major fatty acids (C14:0, C18:0, C18:1, C18:3ω-3, C20:4ω-6 and C22:5ω-6), P, K, Cu and vitamin E as chemical discriminators for the selected species. These elements and compounds exhibited the potential to prove authenticity of the commercially relevant squid species. Copyright © 2014 Elsevier Ltd. All rights reserved.

Selective 5-Hydroxytrytamine 2C Receptor Agonists Derived from the Lead Compound Tranylcypromine – Identification of Drugs with Antidepressant-Like Action

PubMed Central

Cho, Sung Jin; Jensen, Niels H.; Kurome, Toru; Kadari, Sudhakar; Manzano, Michael L.; Malberg, Jessica E.; Caldarone, Barbara; Roth, Bryan L.; Kozikowski, Alan P.

2009-01-01

We report here the design, synthesis, and pharmacological properties of a series of compounds related to tranylcypromine (9), which itself was discovered as a lead compound in a high-throughput screening campaign. Starting from 9, which shows modest activity as a 5-HT2C agonist, a series of 1-aminomethyl-2-phenylcyclopropanes was investigated as 5-HT2C agonists through iterative structural modifications. Key pharmacophore feature of this new class of ligands is a 2-aminomethyl-trans-cyclopropyl side chain attached to a substituted benzene ring. Among the tested compounds, several were potent and efficacious 5-HT2C receptor agonists with selectivity over both 5-HT2A and 5-HT2B receptors in functional assays. The most promising compound is 37 with 120- and 14-fold selectivity over 5-HT2A and 5-HT2B, respectively (EC50 = 585, 65, and 4.8 nM at the 2A, 2B, and 2C subtypes, respectively). In animal studies, compound 37 (10–60 mg/kg) decreased immobility time in the mouse forced swim test. PMID:19284718

(E)-4-Meth-oxy-N'-(2,4,5-tri-meth-oxy-benzyl-idene)benzohydrazide hemihydrate.

PubMed

Chantrapromma, Suchada; Boonnak, Nawong; Horkaew, Jirapa; Quah, Ching Kheng; Fun, Hoong-Kun

2014-02-01

The title compound crystallizes as a hemihydrate, C18H20N2O5·0.5H2O. The mol-ecule exists in an E conformation with respect to the C=N imine bond. The 4-meth-oxy-phenyl unit is disordered over two sets of sites with a refined occupancy ratio of 0.54 (2):0.46 (2). The dihedral angles between the benzene rings are 29.20 (9) and 26.59 (9)°, respectively, for the major and minor components of the 4-meth-oxy-substituted ring. All meth-oxy substituents lie close to the plane of the attached benzene rings [the Cmeth-yl-O-C-C torsion angles range from -4.0 (12) to 3.9 (2)°]. In the crystal, the components are linked into chains propagating along [001] via N-H⋯O and O-H⋯O hydrogen bonds and weak C-H⋯O inter-actions.

Extraction of cesium and strontium from nuclear waste

DOEpatents

Davis, M.W. Jr.; Bowers, C.B. Jr.

1988-06-07

Cesium is extracted from acidified nuclear waste by contacting the waste with a bis 4,4[prime](5) [1-hydroxy-2-ethylhexyl]benzo 18-crown-6 compound and a cation exchanger in a matrix solution. Strontium is extracted from acidified nuclear waste by contacting the waste with a bis 4,4[prime](5[prime]) [1-hydroxyheptyl]cyclohexo 18-crown-6 compound, and a cation exchanger in a matrix solution. 3 figs.

Effect of the surface heterogeneity of the stationary phase on the range of concentration for linear chromatography

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

Gritti, Fabrice; Guiochon, Georges A

2005-02-01

The range of sample sizes within which linear chromatographic behavior is achieved in a column depends on the surface heterogeneity of the RPLC adsorbents. Two widely different commercial adsorbents were tested, the end-capped XTerra-C{sub 18} and the non-end-capped Resolve-C{sub 18}. Adsorption isotherm data of caffeine were acquired by frontal analysis. These data were modeled and used to calculate the adsorption energy distribution (AED). This double analysis informs on the degree of surface heterogeneity. The best adsorption isotherm models are the bi-Langmuir and the tetra-Langmuir isotherms for XTerra and Resolve, respectively. Their respective AEDs are bimodal and quadrimodal distributions. This interpretationmore » of the results and the actual presence of a low density of high-energy adsorption sites on Resolve-C{sub 18} were validated by measuring the dependence of the peak retention times on the size of caffeine samples (20-{micro}L volume, concentrations 10, 1, 0.1, 1 x 10{sup -2}, 1 x 10{sup -3}, 1 x 10{sup -4}, and 1 x 10{sup -5} g/L). The experimental chromatograms agree closely with the band profiles calculated from the best isotherms. On Resolve-C{sub 18}, the retention time decreases by 40% when the sample concentration is increased from 1 x 10{sup -5} to 10 g/L. The decrease is only 10% for Xterra-C{sub 18} under the same conditions. The upper limit for linear behavior is 1 x 10{sup -4} g/L for the former adsorbent and 0.01 g/L for the latter. The presence of a few high-energy adsorption sites on Resolve-C{sub 18}, with an adsorption energy 20 kJ/mol larger than that of the low-energy sites while the same difference on Xterra is only 5 kJ/mol, explains this difference. The existence of adsorption sites with a very high energy for certain compounds affects the reproducibility of their retention times and a rapid loss of efficiency in a sample size range within which linear behavior is incorrectly anticipated.« less

A new triclinic modification of the pyrochlore-type KOs{sub 2}O{sub 6} superconductor

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

Katrych, S.; Gu, Q.F.; Bukowski, Z.

2009-03-15

A new modification of KOs{sub 2}O{sub 6}, the representative of a new structural type (Pearson symbol aP18, a=5.5668(1) A, b=6.4519(2) A, c=7.2356(2) A, {alpha}=65.377(3){sup o}, {beta}=70.572(3){sup o}, {gamma}=75.613(2){sup o} space group P-1, no. 2 was synthesized employing high pressure technique. Its structure was determined by single-crystal X-ray diffraction. The structure can be described as two OsO{sub 6} octahedral chains relating to each other through inversion and forming big voids with K atoms inside. Quantum chemical calculations were performed on the novel compound and structurally related cubic compound. High-pressure X-ray study showed that cubic KOs{sub 2}O{sub 6} phase was stable upmore » to 32.5(2) GPa at room temperature. - Graphical abstract: A new modification of KOs{sub 2}O{sub 6}, the representative of a new structural type (Pearson symbol aP18, a=5.5668(1) A, b=6.4519(2) A, c=7.2356(2) A, {alpha}=65.377(3){sup o}, {beta}=70.572(3){sup o}, {gamma}=75.613(2){sup o} space group P-1, no. 2 was synthesized employing high pressure technique. The structure can be described as two OsO{sub 6} octahedral chains relating to each other through inversion and forming big voids with K atoms inside.« less

Volatile organic compound measurements in the California/Mexico border region during SCOS97

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

Zielinska, B.; Sagebiel, J.; Uberna, E.

1999-07-01

Measurements of volatile organic compounds (VOC) were carried out in the California/Mexico border region during the Southern California Ozone study in the Summer of 1997 (SCOS97). Integrated 3-hr samples were collected in Rosarito (south of Tijuana, Mexico) and in Mexicali during Intensive Operational Periods (IOP), twice per IOP day. VOC were collected using stainless-steel 6 L canisters; carbonyl compounds were collected using 2,4-dinitrophenylhydrazine (DNPH) impregnated C{sub 18} SepPak cartridges. The canister samples were analyzed for speciated volatile hydrocarbons (C{sub 2}-C{sub 12}), CO, CO{sub 2}, CH{sub 4}, MTBE, and halogenated hydrocarbons. DNPH-impregnated cartridges were analyzed for fourteen C{sub 1}-C{sub 7} carbonylmore » compounds. The results of these measurements will be discussed.« less

Rapid and highly sensitive determination of low-molecular-weight carbonyl compounds in drinking water and natural water by preconcentration HPLC with 2,4-dinitrophenylhydrazine.

PubMed

Takeda, Kazuhiko; Katoh, Shinya; Nakatani, Nobutake; Sakugawa, Hiroshi

2006-12-01

The aim of this research was to develop a simple procedure for a highly sensitive determination of low-molecular-weight (LMW) carbonyl compounds in drinking water and natural water. We employed a preconcentration HPLC system with 2,4-dinitrophenylhydrazine (DNPH) for the determination of LMW carbonyl compounds. A C-18 reverse-phase preconcentration column was used instead of a sample loop at the sample injection valve. A 0.1 - 5.0 mL portion of the derivatized sample solution was injected with a gas-tight syringe, and a 15% acetonitrile aqueous solution was pushed through the preconcentration column to remove the unreacted excess DNPH, which caused serious interference in the determination of formaldehyde. The detection limits were 1 - 3 nM with a relative standard deviation of 2 - 5% for 20 nM standard solutions (n = 5). The calibration curves were essentially unaffected by coexisting sea salts. Applications to commercial mineral water, tap water, river water, pond water and seawater are presented.

Synthesis and antimalarial testing of neocryptolepine analogues: addition of ester function in SAR study of 2,11-disubstituted indolo[2,3-b]quinolines.

PubMed

Lu, Wen-Jie; Wicht, Kathryn J; Wang, Li; Imai, Kento; Mei, Zhen-Wu; Kaiser, Marcel; El Sayed, Ibrahim El Tantawy; Egan, Timothy J; Inokuchi, Tsutomu

2013-06-01

This report describes the synthesis, and in vitro and in vivo antimalarial evaluations of certain ester-modified neocryptolepine (5-methyl-5H-indolo[2,3-b]quinoline) derivatives. The modifications were carried out by introducing ester groups at the C2 and/or C9 position on the neocryptolepine core and the terminal amino group of the 3-aminopropylamine substituents at the C11 position with a urea/thiourea unit. The antiplasmodial activities of our derivative agents against two different strains (CQS: NF54, and CQR: K1) and the cytotoxic activity against normal L6 cells were evaluated. The test results showed that the ester modified neocryptolepine derivatives have higher antiplasmodial activities against both strains and a low cytotoxic activity against normal cells. The best results were achieved by compounds 9c and 12b against the NF54 strain with the IC50/SI value as 2.27 nM/361 and 1.81 nM/321, respectively. While against K1 strain, all the tested compounds showed higher activity than the well-known antimalarial drug chloroquine. Furthermore, the compounds were tested for β-haematin inhibition and 12 were found to be more active than chloroquine (IC50 = 18 μM). Structure activity relationship studies exposed an interesting linear correlation between polar surface area of the molecule and β-haematin inhibition for this series. In vivo testing of compounds 7 and 8a against NF54 strain on Plasmodium berghei female mice showed that the introduction of the ester group increased the antiplasmodial activity of the neocryptolepine core substantially. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

Application of mixed-mode, solid-phase extraction in environmental and clinical chemistry. Combining hydrogen-bonding, cation-exchange and Van der Waals interactions

USGS Publications Warehouse

Mills, M.S.; Thurman, E.M.; Pedersen, M.J.

1993-01-01

Silica- and styrene-divinylbenzene-based mixed-mode resins that contain C8, C18 and sulphonated cation-exchange groups were compared for their efficiency in isolation of neutral triazine compounds from water and of the basic drug, benzoylecgonine, from urine. The triazine compounds were isolated by a combination of Van der Waals and hydrogen-bonding interactions, and benzoylecgonine was isolated by Van der Waals interactions and cation exchange. All analytes were eluted with a polar organic solvent contaning 2% ammonium hydroxide. Larger recoveries (95%) were achieved on copolymerized mixed-mode resins where C18 and sulfonic acid are in closer proximity than on 'blended' mixed-mode resins (60-70% recovery).

Further drimane sesquiterpenes from Drimys brasiliensis stem barks with cytotoxic potential.

PubMed

Fratoni, Eduarda; Claudino, Vanessa Duarte; Yunes, Rosendo Augusto; Franchi, Gilberto C; Nowill, Alexandre E; Filho, Valdir Cechinel; Monache, Franco Delle; Malheiros, Angela

2016-07-01

Drimys brasiliensis Miers (Winteraceae) is used in folk medicine for the treatment of cancer. Its anti-tumor activity has been demonstrated in vitro models using extracts and isolated compounds. This study investigates the cytotoxic effects of stem bark extracts of D. brasiliensis as well as isolated compounds that may be responsible for the activitys and evaluates them in leukemia cells. The stem bark extract were subjected to column chromatography, and the structures of compounds were elucidated based on spectroscopic methods by using NMR and infrared spectroscopy and GC/MS. The cytotoxicity of the isolated compounds was evaluated in chronic myeloid (K562) and acute B lymphoblastic (Nalm6) leukemia cells using tetrazolium assay (MTT). Two new compounds were isolated 1β-O-p-methoxy-E-cinnamoyl-5α-keto-11α-enol-albicanol (1a) and the isomer 1β-O-p-methoxy-E-cinnamoyl-5α-keto-11β-enol-albicanol (1b) and 1β-O-p-methoxy-E-cinnamoyl-isodrimeninol (2). The known compounds polygonal acid (3a) and the isomer isopolygonal acid (3b), fuegin (4a) and the isomer epifuegin (4b), the mixture drimanial (5) and 1β-O-(p-methoxy-E-cinnamoyl)-6α-hydroxypolygodial (6) were also isolated. The drimanes (1-4) and drimanial (5), 1β-(p-coumaroyloxy)-polygodial (7), 1β-(p-methoxycinnamoyl)-polygodial (8), and polygodial (9) isolated previously were assessed in tumor cells. The IC50 values were between 3.56 and 128.91 μM. 1-β-(p-cumaroiloxi)-polygodial showed the best result with IC50 8.18 and 3.56 μM by K562 and Nalm6, respectively. The chloroform extract of the stem bark of D. brasiliensis is a great source of drimane sesquiterpenes. Our experimental data suggest that drimanes are responsible for cytotoxicity activity demonstrated by this species, especially those with the aldehyde group linked to carbons C-11 and C-12.

Alkamides from the fruits of Piper longum and Piper nigrum displaying potent cell adhesion inhibition.

PubMed

Lee, Seung Woong; Kim, Young Kook; Kim, Koanhoi; Lee, Hyun Sun; Choi, Jung Ho; Lee, Woo Song; Jun, Chang-Duk; Park, Jee Hun; Lee, Jeong Min; Rho, Mun-Chual

2008-08-15

Eight alkamides 1-8 were isolated by bioassay-guided isolation of EtOH extracts of the fruits of Piper longum and Piper nigum (Piperaceae). Their structures were elucidated by spectroscopic analysis ((1)H, (13)C NMR, and ESI-MS) as follows: guineensine (1), retrofracamide C (2), (2E,4Z,8E)-N-[9-(3,4-methylenedioxyphenyl)-2,4,8-nonatrienoyl]piperidine (3), pipernonaline (4), piperrolein B (5), piperchabamide D (6), pellitorin (7), and dehydropipernonaline (8). Their compounds 3-5, 7, and 8 inhibited potently the direct binding between sICAM-1 and LFA-1 of THP-1 cells in a dose-dependent manner, with IC(50) values of 10.7, 8.8, 13.4, 13.5, and 6.0 microg/mL, respectively.

Structural characterization of two solvates of a luminescent copper(II) bis­(pyridine)-substituted benzimidazole complex

PubMed Central

DeStefano, Matthew R.; Lewis, Robert A.

2017-01-01

Copper(II) complexes of benzimidazole are known to exhibit biological activity that makes them of inter­est for chemotherapeutic and other pharmaceutical uses. The complex bis­(acetato-κO){5,6-dimethyl-2-(pyridin-2-yl)-1-[(pyridin-2-yl)meth­yl]-1H-benzimidazole-κ2 N 2,N 3}copper(II), has been prepared. The absorption spectrum has features attributed to intra­ligand and ligand-field transitions and the complex exhibits ligand-centered room-temperature luminescence in solution. The aceto­nitrile monosolvate, [Cu(C2H3O2)2(C20H18N4)]·C2H3N (1), and the ethanol hemisolvate, [Cu(C2H3O2)2(C20H18N4)]·0.5C2H6O (2), have been structurally characterized. Compound 2 has two copper(II) complexes in the asymmetric unit. In both 1 and 2, distorted square-planar N2O2 coordination geometries are observed and the Cu—N(Im) bond distance is slightly shorter than the Cu—N(py) bond distance. Inter­molecular π–π inter­actions are found in 1 and 2. A weak C—H⋯π inter­action is observed in 1. PMID:29152336

The new Zintl phases Eu{sub 21}Cd{sub 4}Sb{sub 18} and Eu{sub 21}Mn{sub 4}Sb{sub 18}

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

Wang, Yi; Darone, Gregory M.; Bobev, Svilen, E-mail: bobev@udel.edu

Crystals of two new Zintl compounds, Eu{sub 21}Mn{sub 4}Sb{sub 18} and Eu{sub 21}Cd{sub 4}Sb{sub 18} have been synthesized using the molten metal flux method, and their structures have been established by single-crystal X-ray diffraction. Both compounds are isotypic and crystallize in the monoclinic space group C2/m (No. 12, Z=4). The structures are based on edge- and corner-shared MnSb{sub 4} or CdSb{sub 4} tetrahedra, which make octameric [Mn{sub 8}Sb{sub 22}] or [Cd{sub 8}Sb{sub 22}] polyanions. Homoatomic Sb–Sb bonds are present in both structures. The Eu atoms take the role of Eu{sup 2+}cations with seven unpaired 4f electrons, as suggested by themore » temperature-dependent magnetization measurements. The magnetic susceptibilities of Eu{sub 21}Mn{sub 4}Sb{sub 18} and Eu{sub 21}Cd{sub 4}Sb{sub 18} indicate that both phases order anti-ferromagnetically with Néel temperatures of ca. 7 K and ca. 10 K, respectively. The unpaired 3d electrons of the Mn atoms in Eu{sub 21}Mn{sub 4}Sb{sub 18} do contribute to the magnetic response, however, the bulk magnetization measurements do not provide evidence for long-range ordering of the Mn spins down to 5 K. Electrical resistivity measurements suggest that both compounds are narrow band gap semiconductors. - Graphical abstract: Eu{sub 21}Mn{sub 4}Sb{sub 18} and Eu{sub 21}Cd{sub 4}Sb{sub 18} have complex monoclinic structures, based on MnSb{sub 4} and CdSb{sub 4} tetrahedra, both edge- and corner-shared. A perspective of the crystal structure is shown, as viewed along the b axis. Display Omitted - Highlights: • Eu{sub 21}Mn{sub 4}Sb{sub 18} and Eu{sub 21}Cd{sub 4}Sb{sub 18} are novel compounds in the respective ternary phase diagrams. • For both structures, the Zintl-Klemm rules are followed, and both are small gap semiconductors. • Eu{sub 21}Mn{sub 4}Sb{sub 18} and Eu{sub 21}Cd{sub 4}Sb{sub 18} are air-stable Zintl phases and could be new thermoelectric materials.« less

Secondary metabolites of Centaurea calolepis and evaluation of cnicin for anti-inflammatory, antioxidant, and cytotoxic activities.

PubMed

Erel, Sura Baykan; Karaalp, Canan; Bedir, Erdal; Kaehlig, Hanspeter; Glasl, Sabine; Khan, Shabana; Krenn, Liselotte

2011-08-01

Centaurea L. (Astreaceae) species are used as herbal remedies in Turkey. Centaurea calolepis Boiss. is an endemic species of Anatolia that has not been subjected to phytochemical studies except essential oil analysis. Secondary metabolite determination, isolation and structure elucidation of pure compounds were performed on C. calolepis. Cnicin, which is the main component of several Centaurea species, was tested for its in vitro anti-inflammatory, antioxidant and cytotoxic activities. Chloroform and methanol extracts of the aerial parts of C. calolepis were subjected to isolation process using column chromatography. The structures of the compounds were characterized by 1D- and 2D-NMR experiments. Thin-layer chromatography and high performance liquid chromatography were used in determination of phenolics. Cnicin was subjected to a panel of cellular assays to test for inhibition of nuclear factor κB (NF-κB), inducible nitric oxide synthase (iNOS), reactive oxygen species and cytotoxicity. Cnicin, lucenin-2, schaftoside and 3-O-feruloylquinic acid were isolated from C. calolepis extracts. Vicenin-2, vitexin, isovitexin, homoorientin, rutin, orientin, luteolin-7-O-glycoside and chlorogenic acid were determined in fractions. Cnicin showed inhibition of NF-κB and inhibition of iNOS activity with IC₅₀ Values of 1.8 and 6.5 µM, respectively. Cytotoxic activity of cnicin was observed toward pig kidney epithelial (LLC-PK₁₁), human malignant melanoma (SK-MEL) and human ductal carcinoma (BT-549) cells with IC₅₀ values of 23.3, 14.0 and 18.3 µM, respectively. This is the first detailed report of secondary metabolites of C. calolepis. Evaluation of biological activity of cnicin establishes the potential of this compound as an anti-inflammatory and cytotoxic agent.

Synthesis, characterization, and first successful monkey imaging studies of metabotropic glutamate receptor subtype 5 (mGluR5) PET radiotracers.

PubMed

Hamill, Terence G; Krause, Stephen; Ryan, Christine; Bonnefous, Celine; Govek, Steve; Seiders, T Jon; Cosford, Nicholas D P; Roppe, Jeffrey; Kamenecka, Ted; Patel, Shil; Gibson, Raymond E; Sanabria, Sandra; Riffel, Kerry; Eng, Waisi; King, Christopher; Yang, Xiaoqing; Green, Mitchell D; O'Malley, Stacey S; Hargreaves, Richard; Burns, H Donald

2005-06-15

Three metabotropic glutamate receptor subtype 5 (mGluR5) PET tracers have been labeled with either carbon-11 or fluorine-18 and their in vitro and in vivo behavior in rhesus monkey has been characterized. Each of these tracers share the common features of high affinity for mGluR5 (0.08-0.23 nM vs. rat mGluR5) and moderate lipophilicity (log P 2.8-3.4). Compound 1b was synthesized using a Suzuki or Stille coupling reaction with [11C]MeI. Compounds 2b and 3b were synthesized by a SNAr reaction using a 3-chlorobenzonitrile precursor. Autoradiographic studies in rhesus monkey brain slices using 2b and 3b showed specific binding in cortex, caudate, putamen, amygdala, hippocampus, most thalamic nuclei, and lower binding in the cerebellum. PET imaging studies in monkey showed that all three tracers readily enter the brain and provide an mGluR5-specific signal in all gray matter regions, including the cerebellum. The specific signal observed in the cerebellum was confirmed by the autoradiographic studies and saturation binding experiments that showed tracer binding in the cerebellum of rhesus monkeys. In vitro metabolism studies using the unlabeled compounds showed that 1a, 2a, and 3a are metabolized slower by human liver microsomes than by monkey liver microsomes. In vivo metabolism studies showed 3b to be long-lived in rhesus plasma with only one other more polar metabolite observed. (c) 2005 Wiley-Liss, Inc.

Inhibitory effect of red koji extracts on mushroom tyrosinase.

PubMed

Wu, Li-Chen; Chen, Yun-Chen; Ho, Ja-An Annie; Yang, Chung-Shi

2003-07-16

Red koji has been recognized as a cholesterol-lowering diet supplement because of it contains fungi metabolites, monacolins, which reduce cholesterol synthesis by inhibiting HMG-CoA reductase. In this study, water extracts of red koji were loaded onto a C(18) cartridge, and the acetonitrile eluate was collected as test fraction. Red koji water extracts and its C(18) cartridge acetonitrile eluent had total phenols concentrations of 5.57 and 1.89 mg/g of red koji and condensed tannins concentrations of 2.71 and 1.20 mg/g of red koji, respectively. Both exhibited an antioxidant activity and an inhibitory activity to mushroom tyrosinase. The higher antioxidant activity of the red koji acetonitrile eluent was due to the existence of a high percentage of condensed tannins. The results from the kinetic study for inhibition of mushroom tyrosinase by red koji extracts showed that the compounds in the extracts competitively inhibited the oxidation of tyrosine catalyzed by mushroom tyrosinase with an ID(50) of 5.57 mg/mL.

Minor dehydrogenated and cleavaged dammarane-type saponins from the steamed roots of Panax notoginseng.

PubMed

Gu, Cheng-Zhen; Lv, Jun-Jiang; Zhang, Xiao-Xia; Yan, Hui; Zhu, Hong-Tao; Luo, Huai-Rong; Wang, Dong; Yang, Chong-Ren; Xu, Min; Zhang, Ying-Jun

2015-06-01

Nine new minor dehydrogenated and cleavaged dammarane-type triterpenoid saponins, namely notoginsenosides ST6-ST14 (1-9) were isolated from the steamed roots of Panax notoginseng, together with 14 known ones. Among them, 5-7 and 21-22 were protopanaxadiol type and the left 18 compounds, including 1-4, 8-20, and 23 were protopanaxatriol type saponins. Their structures were identified by extensive analysis of MS, 1D and 2D NMR spectra, and acidic hydrolysis. Resulted from the side chain cleavage, the new saponins 1 and 2 featured in a ketone group at C-25, and 3-5 had an aldehyde unit at C-23. The known saponins 12, 16 and 18 displayed the enhancing potential of neurite outgrowth of NGF-mediated PC12 cells at a concentration of 10 μM, while 20 exhibited acetyl cholinesterase inhibitory activity, with IC50 value of 13.97 μM. Copyright © 2015 Elsevier B.V. All rights reserved.

The effects of diet and breed on the volatile compounds of cooked lamb.

PubMed

Elmore, J S; Mottram, D S; Enser, M; Wood, J D

2000-06-01

The effect of varying the n-3 polyunsaturated fatty acid (PUFA) composition of lamb muscle on the formation of aroma volatiles during cooking has been examined. The meat was obtained from four groups of Suffolk and Soay lambs fed different supplementary fats: a palm-oil based control; bruised whole linseed, which increased muscle levels of α-linolenic acid (C18:3 n-3); fish oil, which increased eicosapentaenoic acid (EPA, C20:5 n-3) and docosahexaenoic acid (DHA, C22:6 n-3); and equal quantities of linseed and fish oil (fat basis). Higher quantities of lipid oxidation products were found in the aroma volatiles of lamb muscle from animals fed fish oil, compared to the control. In particular, unsaturated aldehydes, unsaturated hydrocarbons and alkylfurans increased up to fourfold. These compounds derived from the autoxidation of PUFAs during cooking. Although some of these volatiles were increased in meat from animals fed the linseed supplement, the effect was not as great as with the fish oil fed lambs. Levels of volatiles derived from the Maillard reaction, such as pyrazines and sulfur compounds, were up to four times higher in Soays than Suffolks.

Assessment of in vitro cardiotoxicity of extract fractions and diterpene alkaloids from Aconitum leucostomum Worosch: A short communication.

PubMed

Nie, Jihong; Wang, Fang; Ji, Tengfei; Zhao, Jun; Zhao, Feicui

2017-04-15

Aconitum leucostomum Worosch is a traditional Chinese medicine (TCM) and has a broad spectrum of health effects, but with a narrow therapeutic window. It is important to identify both the therapeutic ingredients and the toxic components to better utilize this TCM. The present study investigated the cardiotoxicity of the selected compounds in Aconitum leucostomum Worosch. The effects of extract of A. leucostomum Worosch and the isolated compounds on cardiocardiomyocytes were evaluated in vitro. Five known compounds in this TCM, including three C 18 -diterpene alkaloids, lappaconitine (2), N-deacetyllappaconitine (3), and ranaconitine (5), and two C 19 -diterpene alkaloids, delvestidine (1) and anthranoyllycoctonine (4), were isolated from A. leucostomum Worosch. The cardiotoxicity of these components and extract fractions, as measured by lactate dehydrogenase release and apoptosis, was ranked as follows, in descending order: delvestidine>anthranoyllycoctonine>pH 4 fraction>pH 8 fraction>aconitine>N-deacetyllappaconitine>ranaconitine>lappaconitine. The cytotoxicity of these compounds was shown to be dose-dependent, with delvestidine (1) and anthranoyllycoctonine (4) being the two most toxic compounds to cardiomyocytes in our assays. These results provide a basis for future rational use of this TCM, reducing side effects while retaining therapeutic effects. Copyright © 2017 Elsevier B.V. All rights reserved.

[Analysis of variation of monoterpene glycosides and polyhydroxy compounds in paeoniae radix alba during preliminary processing].

PubMed

Xu, Yuan; Liu, Pei; Yan, Hui; Qian, Da-Wei; Duan, Jin-Ao

2014-05-01

To investigate variation of monoterpene glycosides and polyhydroxy compounds in Paeoniae Radix Alba dried by different processing methods. The crude drugs were processed sequentially as washed, removed the head, tail, fine roots and dried. The samples were divided into eight groups by whether peeled and decocted or not. Each group was dried by 35, 45, 60, 80,100, 120 degrees C, sun-dried and shade-dried. HPLC-PDA method was adopted to determine the content of monoterpene glycosides compounds (paeoniflorin alibiflorin, oxypaeoniflorin and benzoylpaeoniflorin), polyhydroxy compounds (catechin and gallic acid) and benzoic acid. Chromatographic conditions: Phecad C18 column (250 mm x 4.6 mm, 5 microm). A principal component analysis (PCA) method was used subsequently to get data processed. The retained content of seven constituents decreased in those peeled crude drug, and after cooked, monoterpene glycosides and polyhydroxy compounds increased while the benzoic acid decreased. It was believed that rele- vant enzymes were inactivated while being cooked so that drying temperature showed little influence on the biotransformation. Contents of effective ingredients in Paeoniae Radix Alba are influenced by drying processing. The preferable method shows to be that crude drug should be cooked before being peeled and dried. As a matter of processing convtence, it is suggested to be peeled and sliced before being dried.

Determination of phenolic compounds derived from hydrolysable tannins in biological matrices by RP-HPLC.

PubMed

Díez, María Teresa; García del Moral, Pilar; Resines, José Antonio; Arín, María Jesús

2008-08-01

An RP-HPLC method for the determination of four phenolic compounds: gallic acid (GA), pyrogallol (PY), resorcinol (RE) and ellagic acid (EA), derived from hydrolysable tannins is reported. Separation was achieved on a SunFire C18 (250 x 4.6 mm id, 5 microm) column at 40 degrees C with gradient elution. UV detection at 280 nm was applied. The developed method was validated in terms of linearity, accuracy and precision. Satisfactory repeatability and between day precision were noticed with RSD values lower than 3%. Recoveries from different biological samples ranged from 91.50 to 105.25%. The LODs were estimated as 1.70 mg/L for PY, 1.68 mg/L for GA, 1.52 mg/L for RE and 0.98 mg/L for EA with a 20 microL injection volume. The method was applied for the determination of these compounds in oak leaves and in ruminal fluid and urine samples taken from beef cattle fed with oak leaves. The proposed method could be used in ruminant nutrition studies to verify the effect that a diet rich in tannins have on ruminal fermentation and to determine the toxicity of these compounds.

Investigating the potential of under-utilised plants from the Asteraceae family as a source of natural antimicrobial and antioxidant extracts.

PubMed

Kenny, O; Smyth, T J; Walsh, D; Kelleher, C T; Hewage, C M; Brunton, N P

2014-10-15

Antimicrobial properties of ethanol and water extracts from eight Asteraceae species were investigated against three Gram positive (Staphylococcus aureus, MRSA and Bacillus cereus) and two Gram negative (Escherichia coli and Salmonella typhimurium) bacterial strains. Ethanol extracts from Centaurea scabiosa, Arctium minus, Taraxacum officinale, Centaurea nigra and Cirsium palustre demonstrated antimicrobial activity against strains of S. aureus, MRSA and B. cereus (MIC=187.5-365μg/ml). Ethanol extracts also had higher antioxidant activities and phenolic content demonstrating a link between these compounds and the bioactivity of these extracts. Further investigation into the phenolic content of ethanol extracts using UPLC-MS/MS lead to the identification and quantification of numerous phenolic compounds in all species including; 18 from Cirsium arvense, 16 from Cirsium vulgare, 19 from C. palustre, 15 from C. nigra, 17 from C. scabiosa, 14 from Sonchus asper, 17 from A. minus and 11 from T. officinale. Copyright © 2014 Elsevier Ltd. All rights reserved.

Catalytic conversion of biomass pyrolysis-derived compounds with chemical liquid deposition (CLD) modified ZSM-5.

PubMed

Zhang, Huiyan; Luo, Mengmeng; Xiao, Rui; Shao, Shanshan; Jin, Baosheng; Xiao, Guomin; Zhao, Ming; Liang, Junyu

2014-03-01

Chemical liquid deposition (CLD) with KH550, TEOS and methyl silicone oil as the modifiers was used to modify ZSM-5 and deposit its external acid sites. The characteristics of modified catalysts were tested by catalytic conversion of biomass pyrolysis-derived compounds. The effects of different modifying conditions (deposited amount, temperature, and time) on the product yields and selectivities were investigated. The results show KH550 modified ZSM-5 (deposited amount of 4%, temperature of 20°C and time of 6h) produced the maximum yields of aromatics (24.5%) and olefins (16.5%), which are much higher than that obtained with original ZSM-5 catalyst (18.8% aromatics and 9.8% olefins). The coke yield decreased from 44.1% with original ZSM-5 to 26.7% with KH550 modified ZSM-5. The selectivities of low-molecule-weight hydrocarbons (ethylene and benzene) decreased, while that of higher molecule-weight hydrocarbons (propylene, butylene, toluene, and naphthalene) increased comparing with original ZSM-5. Copyright © 2013 Elsevier Ltd. All rights reserved.

Surface-segregated monolayers: a new type of ordered monolayer for surface modification of organic semiconductors.

PubMed

Wei, Qingshuo; Tajima, Keisuke; Tong, Yujin; Ye, Shen; Hashimoto, Kazuhito

2009-12-09

We report a new type of ordered monolayer for the surface modification of organic semiconductors. Fullerene derivatives with fluorocarbon chains ([6,6]-phenyl-C(61)-buryric acid 1H,1H-perfluoro-1-alkyl ester or FC(n)) spontaneously segregated as a monolayer on the surface of a [6,6]-phenyl-C(61)-butyric acid methyl ester (PCBM) film during a spin-coating process from the mixture solutions, as confirmed by X-ray photoelectron spectroscopy (XPS). Ultraviolet photoelectron spectroscopy (UPS) showed the shift of ionization potentials (IPs) depending on the fluorocarbon chain length, indicating the formation of surface dipole moments. Surface-sensitive vibrational spectroscopy, sum frequency generation (SFG) revealed the ordered molecular orientations of the C(60) moiety in the surface FC(n) layers. The intensity of the SFG signals from FC(n) on the surface showed a clear odd-even effect when the length of the fluorocarbon chain was changed. This new concept of the surface-segregated monolayer provides a facile and versatile approach to modifying the surface of organic semiconductors and is applicable to various organic optoelectronic devices.

Ferrocenyl-cymantrenyl hetero-bimetallic chalcones: Synthesis, structure and biological properties

NASA Astrophysics Data System (ADS)

Mishra, Sasmita; Tirkey, Vijaylakshmi; Ghosh, Avishek; Dash, Hirak R.; Das, Surajit; Shukla, Madhulata; Saha, Satyen; Mobin, Sheikh M.; Chatterjee, Saurav

2015-04-01

Two new ferrocenyl-cymantrenyl bimetallic chalcones, [(CO)3Mn(η5-C5H4)C(O)CHdbnd CH(η5-C5H4)Fe(η5-C5H5)] (1) and [{(CO)3Mn(η5-C5H4)C(O)CHdbnd CH(η5-C5H4)}2Fe] (2) have been synthesized. Their reactivity study with triphenylphosphine and bis-(diphenylphosphino)ferrocene led to the isolation of phosphine substituted bimetallic chalcones (3-6). Single crystal X-ray structural characterization for 1 and its phosphine analogue (3) reveals their different conformational identity with anti-conformation for 1, while syn-conformation for 3. Investigation of antimalarial and antibacterial activities was carried out for compounds 1 and 2 against two strains of Plasmodium falciparum (3D7, K1) and four bacterial strains. TD-DFT calculation was performed for compound 1 and electrochemical properties were studied for bimetallic chalcone compounds by cyclic voltammetric technique.

Synthesis of Fluorine-Containing Phosphodiesterase 10A (PDE10A) Inhibitors and the In Vivo Evaluation of F-18 Labeled PDE10A PET Tracers in Rodent and Nonhuman Primate

PubMed Central

Li, Junfeng; Zhang, Xiang; Jin, Hongjun; Fan, Jinda; Flores, Hubert; Perlmutter, Joel S.; Tu, Zhude

2015-01-01

A series of fluorine-containing PDE10A inhibitors were designed and synthesized to improve the metabolic stability of [11C]MP-10. Twenty of the 22 new analogues had high potency and selectivity for PDE10A: 18a–j, 19d–j, 20a–b, and 21b had IC50 values <5 nM for PDE10A. Seven F-18 labeled compounds [18F]18a–e, [18F]18g, and [18F]20a were radiosynthesized by 18F-introduction onto the quinoline rather than the pyrazole moiety of the MP-10 pharmacophore and performed in vivo evaluation. Biodistribution studies in rats showed ~2-fold higher activity in the PDE10A-enriched striatum than nontarget brain regions; this ratio increased from 5 to 30 min postinjection, particularly for [18F]18a–d and [18F]20a. Micro-PET studies of [18F]18d and [18F]20a in nonhuman primates provided clear visualization of striatum with suitable equilibrium kinetics and favorable metabolic stability. These results suggest this strategy may identify a 18F-labeled PET tracer for quantifying the levels of PDE10A in patients with CNS disorders including Huntington’s disease and schizophrenia. PMID:26430878

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

Disselkamp, Robert S.; Denslow, Kayte M.; Hart, Todd R.

We have studied the effect of cavitating ultrasound on the heterogeneous aqueous hydrogenation of cis-2-buten-1-ol (C4 olefin) and cis-2-penten-1-ol (C5 olefin) on Pd-black to form the trans-olefins (trans-2-buten-1-ol and trans-2-penten-1-ol) and saturated alcohols (1-butanol and 1-pentanol, respectively). Silent (and magnetically stirred) experiments served as control experiments. As described in an earlier publication by our group, we have added an inert dopant, 1-propanol, in the reaction mixture to ensure the rapid onset of cavitation in the ultrasound-assisted reactions that can lead to altered selectivity compared to silent reaction systems [R.S. Disselkamp, Ya-Huei Chin, C.H.F. Peden, J. Catal. 227 (2004) 552]. Themore » motivation for this study is to examine whether cavitating ultrasound can reduce the [trans-olefin/saturated alcohol] molar ratio during the course of the reaction. This could have practical application in that it may offer an alternative processing methodology of synthesizing healthier edible seed oils by reducing trans-fat content.We have observed that cavitating ultrasound results in a [(trans-olefin/saturated alcohol)ultrasound/(trans-olefin/saturated alcohol)silent] ratio quantity less than 0.5 at the reaction mid-point for both the C4 and C5 olefin systems. This indicates that ultrasound reduces trans-olefin production compared to the silent control experiment. Furthermore, there is an added 30% reduction for the C5 versus C4 olefin compounds again at reaction mid-point. We attribute differences in the ratio quantity as a moment of inertia effect. In principle, the C4 versus C5 olefins has a {approx}52% increase in moment of inertia about C2 C3 double bond slowing isomerization. Since seed oils are C18 multiple cis-olefins and have a moment of inertia even greater than our C5 olefin here, our study suggests that even a greater reduction in trans-olefin content may occur for partial hydrogenation of C18 seed oils.« less

Qualitative evaluation and quantitative determination of 10 major active components in Carthamus tinctorius L. by high-performance liquid chromatography coupled with diode array detector.

PubMed

Fan, Li; Zhao, Hai-Yu; Xu, Man; Zhou, Lei; Guo, Hui; Han, Jian; Wang, Bao-Rong; Guo, De-An

2009-03-13

Flavonoids in the water extract of Carthamus tinctorius L. exhibit potent biological activities such as anti-coagulant, vasodilation, anti-oxidant, neuroprotection and immunosuppressant. A high-performance liquid chromatographic method was established to evaluate the quality of Carthamus tinctorius through a simultaneous quantitation of eight flavonoids, hydroxysafflor yellow A (2), 6-hydroxykaempferol 3,6-di-O-beta-glucoside-7-O-beta-glucuronide (3), 6-hydroxykaempferol 3,6,7-tri-O-beta-glucoside (4), 6-hydroxykaempferol 3-O-beta-rutinoside-6-O-beta-glucoside (6), 6-hydroxykaempferol 3,6-di-O-beta-glucoside (7), 6-hydroxyapigenin 6-O-glucoside-7-O-glucuronide (8), anhydrosafflor yellow B (9), and kaempferol 3-O-beta-rutinoside (10), together with two other compounds named guanosine (1) and syringin (5). Among them, compound 8 was identified as a new compound. The compounds were separated on an Alltech Alltima-C(18) column with gradient elution of acetonitrile and 0.01% trifluoroacetic acid. The detection wavelength was 280 nm. All the compounds showed good linearity (r(2) >or= 0.9989). The recoveries, measured at three concentration levels, varied from 94.9% to 105.2%. This method was also validated with respect to precision, repeatability and accuracy, and was successfully applied to quantify the 10 components in 46 batches of C. tinctorius samples from different areas. Significant variations were found in the contents of these compounds in these samples. Compared with the reported analytical methods of C. tinctorius, this simple and reliable method provided a new basis for overall assessment on quality of C. tinctorius and should be considered as a suitable quality control method.

Synthesis and Cytotoxic Activities of Difluoro-Dimethoxy Chalcones.

PubMed

Yamali, Cem; Gul, Halise Inci; Ozgun, Dilan Ozmen; Sakagam, Hiroshi; Umemura, Naoki; Kazaz, Cavit; Gul, Mustafa

2017-01-01

Although anticancer chemotherapeutics are available in markets, side effects related to the drugs in clinical use lead to researchers to investigate new drug candidates which are more safe, potent and selective than others. Chalcones are popular with their anticancer activities with the several reported mechanisms including inhibition of angiogenesis, inhibition of tubulin polymerization, and induction of apoptosis etc. This study was focused on to synthesize of 1-(2,4/2,6-difluorophenyl)-3-(2,3/2,4/2,5/3,4- dimethoxyphenyl)-2-propen-1-ones (1-8) and investigate their cytotoxic properties with possible mechanism of action. The compounds were synthesized by Claisen-Schmidt condensation. The chemical structures were confirmed by 1H NMR, 13C NMR, DEPT, COSY, HMQC, HMBC, 19F NMR and HRMS. In vitro cytotoxic effects of the compounds against human tumour cell lines [gingival carcinoma (Ca9-22), oral squamous cell carcinoma (HSC-2)] and human normal oral cells [gingival fibroblasts (HGF), periodontal ligament fibroblasts (HPLF)] were evaluated via MTT test. All compounds had higher cytotoxicity than reference compound 5-Fluorouracil (5-FU). The compounds 3-7 had higher potency selectivity expression values (PSE) than 5-FU and PSE values of the compounds were over 100. All chalcone derivatives seem good candidates for further studies according to very remarkable and high PSE values. It was clearly demonstrated that compound 7 can induce early apoptosis at a concentration of 10 µM and dose-dependent late apoptosis starting at 10 µM. Compound 7 induced cleavage of the apoptosis marker PARP. The results indicate that new chalcones reported here can promote apoptosis in human tumour cell lines. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

In situ continuous derivatization/pre-concentration of carbonyl compounds with 2,4-dinitrophenylhydrazine in aqueous samples by solid-phase extraction Application to liquid chromatography determination of aldehydes.

PubMed

Baños, Clara-Eugenia; Silva, Manuel

2009-03-15

A rapid and straightforward continuous solid-phase extraction system has been developed for in situ derivatization and pre-concentration of carbonyl compounds in aqueous samples. Initially 2,4-dinitrophenylhydrazine, the derivatizing agent, was adsorbed on a C(18) mini-column and then 15-ml of sample were continuously aspirated into the flow system, where the derivatization and pre-concentration of the analytes (low-molecular mass aldehydes) were performed simultaneously. Following elution, 20 microl of the extract were injected into a LC-DAD system, in which hydrazones were successfully separated in 12 min on a RP-C(18) column using a linear gradient mobile phase of acetonitrile-water of 60-100% acetonitrile for 8 min, flowing at 0.5 ml/min. The whole analytical process can be accomplished within ca. 35 min. Under optimum conditions, limits of detection were obtained between 0.3 and 1.0 microg/l and RSDs (inter-day precision) from 1.2 to 4.6%. Finally, some applications on water samples are presented with recoveries ranged from 95.8 to 99.4%.

Soluble epoxide hydrolase inhibitory activity of components from Leonurus japonicus.

PubMed

Leem, Hyun Hee; Lee, Ga Young; Lee, Ji Sun; Lee, Hanna; Kim, Jang Hoon; Kim, Young Ho

2017-10-01

One new compound, 10-methoxy-leonurine (1), and four known compounds (2-5) were purified by silica gel, C-18, and Sephadex LH-20 column chromatography from Leonurus japonicus. Their structures were elucidated using one-dimensional (1D)/two-dimensional (2D)-nuclear magnetic resonance (NMR), high-resolution (HR)-electrospray ionization (ESI) mass spectrometry (MS). The compounds were evaluated to determine their inhibition of the catalysis of soluble epoxide hydrolase (sEH). According to the results from in vitro analyses, compounds 1 and 2, which contain guanidine and flavonoid (3), were determined to be potential inhibitors of this enzyme. All compounds were revealed to be non-competitive inhibitors according to Lineweaver-Burk plots. Furthermore, in silico molecular docking indicated that compounds 1-3 are bound to sEH in a similar fashion and have stable binding energies, as calculated by AutoDock 4.2. Molecular dynamics determined the root-mean-square deviation (RMSD), total energy, RMS fluctuation (RMSF), hydrogen bonds, and distance of the complex according to time. Copyright © 2017 Elsevier B.V. All rights reserved.

Quantum chemical study on the NLO and NBO properties of 4-hydroxy quinoline-2-carboxylic acid

NASA Astrophysics Data System (ADS)

Pattanayak, Subrat Kumar

2018-05-01

The nonlinear optical properties and natural bond analysis properties, different global chemical reactivity properties of the compound 4-hydroxy quinoline-2-carboxylic acid are studied by density function theory. The dipole moment (μ) and linear polarizability are found 1.60259 D and 15.138×10-24esu respectively. A comparatively greater value dipole moment 1.46154 D is obtained in direction of μy. It was observed the interaction energies of acceptor of NBO C1 - C2 and donor C5 - C6, NBO of C13 - N15 and C9 - C12, NBO of C13 - N15 and C18 - O21, NBO of O19 and C18 - O21 are 30.92, 358.86, 320.39, 58.55 Kcal/mol. We are getting the low ionization energy 7.033 electron volt (eV) for the studied molecule, which indicates the high inhibition efficiency. Here we note that, high value of ionisation energy indicating the high stability as well as inertness of that molecule. The HOMO and LUMO energies are found -7.033 eV and -2.5212 eV respectively.

3-Ethyl-5-(4-meth­oxy­phen­oxy)-2-(pyridin-4-yl)-3H-imidazo[4,5-b]pyridine

PubMed Central

Ranjith, S.; SubbiahPandi, A.; Suresh, A. D.; Pitchumani, K.

2011-01-01

In the title compound, C20H18N4O2, the imidazopyridine fused ring system is almost perpendicular to the benzene ring [dihedral angle = 87.6 (5)°]. The pyridine ring makes a dihedral angle of 35.5 (5)° with the mean plane of the imidazopyridine fragment. The crystal structure is stabilized by an aromatic π–π stacking inter­action between the phenyl rings of neighbouring mol­ecules [centroid–centroid distance = 3.772 (2) Å, inter­planar distance = 3.546 (2) Å and slippage = 1.286 (2) Å]. PMID:21837144

3-Substituted 1,5-Diaryl-1 H-1,2,4-triazoles as Prospective PET Radioligands for Imaging Brain COX-1 in Monkey. Part 2: Selection and Evaluation of [11C]PS13 for Quantitative Imaging.

PubMed

Shrestha, Stal; Singh, Prachi; Cortes-Salva, Michelle Y; Jenko, Kimberly J; Ikawa, Masamichi; Kim, Min-Jeong; Kobayashi, Masato; Morse, Cheryl L; Gladding, Robert L; Liow, Jeih-San; Zoghbi, Sami S; Fujita, Masahiro; Innis, Robert B; Pike, Victor W

2018-06-13

In our preceding paper (Part 1), we identified three 1,5-bis-diaryl-1,2,4-triazole-based compounds that merited evaluation as potential positron emission tomography (PET) radioligands for selectively imaging cyclooxygenase-1 (COX-1) in monkey and human brain, namely, 1,5-bis(4-methoxyphenyl)-3-(alkoxy)-1 H-1,2,4-triazoles bearing a 3-methoxy (PS1), a 3-(2,2,2-trifluoroethoxy) (PS13), or a 3-fluoromethoxy substituent (PS2). PS1 and PS13 were labeled from phenol precursors by O- 11 C-methylation with [ 11 C]iodomethane and PS2 by O- 18 F-fluoroalkylation with [ 2 H 2 , 18 F]fluorobromomethane. Here, we evaluated these PET radioligands in monkey. All three radioligands gave moderately high uptake in brain, although [ 2 H 2 , 18 F]PS2 also showed undesirable radioactivity uptake in skull. [ 11 C]PS13 was selected for further evaluation, mainly based on more favorable brain kinetics than [ 11 C]PS1. Pharmacological preblock experiments showed that about 55% of the radioactivity uptake in brain was specifically bound to COX-1. An index of enzyme density, V T , was well identified from serial brain scans and from the concentrations of parent radioligand in arterial plasma. In addition, V T values were stable within 80 min, suggesting that brain uptake was not contaminated by radiometabolites. [ 11 C]PS13 successfully images and quantifies COX-1 in monkey brain, and merits further investigation for imaging COX-1 in monkey models of neuroinflammation and in healthy human subjects.

Magnetic properties of diruthenium(II,III) carboxylate compounds. Crystal structures of Ru2Cl(mu-O2CCH=CHCH=CHMe)4 and Ru2Cl(mu-O2CCH2OMe)4.

PubMed

Barral, M C; Jiménez-Aparicio, R; Pérez-Quintanilla, D; Priego, J L; Royer, E C; Torres, M R; Urbanos, F A

2000-01-10

The reaction of Ru2Cl(mu-O2CMe)4 with 2,4-hexadienoic and 2-methoxyacetic acids affords the compounds Ru2Cl(mu-O2CR)4 [R = CH=CHCH=CHCH3 (1), CH2OMe (2)]. The structures of both complexes have been determined by X-ray crystallography. 1 crystallizes in the triclinic space group P-1 with a = 9.264(1) A, b = 12.661(8) A, c = 12.839(5) A, alpha = 106.09(3) degrees, beta = 77.89(2) degrees, gamma = 97.73(3) degrees, and Z = 2. 2 crystallizes in the nonstandard monoclinic space group P2(1)/c with a = 12.132(4) A, b = 11.570(2) A, c = 13.674(2) A, beta = 91.18(2) degrees, and Z = 4. Complexes 1 and 2 show [Ru2(mu-O2CR)4]+ units linked by chloride ions, giving zigzag chains with Ru-Cl-Ru angles of 119.43(4) degrees and 110.11(7) degrees, respectively. The Ru-Ru bond distances are 2.2857(9) A (1) and 2.290(1) A (2). A magnetic study, in the 2-300 K temperature range, of the new compounds and the previously described Ru2Cl(mu-O2CR)4 [R = CHMe2 (3), CMe3 (4), C4H4N (5)] is described. The polymeric complexes 1 and 2 and the nonpolymeric 3-5 show a large zero-field splitting which varies from 53.9 to 68.1 cm-1. These complexes also show a weak, but not negligible, through-space intermolecular antiferromagnetic coupling not observed in the previous magnetic studies carried out on these types of compounds.

Development and validation of an HPLC/UV/MS method for simultaneous determination of 18 preservatives in grapefruit seed extract.

PubMed

Ganzera, Markus; Aberham, Anita; Stuppner, Hermann

2006-05-31

Grapefruit seed extracts are used in cosmetics, food supplements, and pesticides because of their antimicrobial properties, but suspicions about the true nature of the active compounds arose when synthetic disinfectants such as benzethonium or benzalkonium chloride were found in commercial products. The HPLC method presented herein allows the quality assessment (qualitative and quantitative) of these products for the first time. On the basis of a standard mixture of 18 preservatives most relevant for food and grapefruit products, a method was developed allowing the baseline separation of all compounds within 40 min. Optimum results were obtained with a C-8 stationary phase and a solvent system comprising aqueous trifluoroacetic acid, acetonitrile, and 2-propanol. The assay was fully validated and shown to be sensitive (LOD < or= 12.1 ng on-column), accurate (recovery rates > or = 96.1%), repeatable (sigma(rel) < or = 3.5%), precise (intra-day variation < or = 4.5%, interday variation < or = 4.1%), and rugged. Without any modifications the method could be adopted for LC-MS experiments, where the compounds of interest were directly assignable in positive ESI mode. The quantitative results of several products for ecofarming confirmed previous studies, as seven out of nine specimens were adulterated with preservatives in varying composition. The samples either contained benzethonium chloride (2.5-176.9 mg/mL) or benzalkonium chloride (138.2-236.3 mg/mL), together with smaller amounts of 4-hydroxybenzoic acid esters, benzoic acid, and salicylic acid.

Design and Discovery of Functionally Selective Serotonin 2C (5-HT2C) Receptor Agonists.

PubMed

Cheng, Jianjun; McCorvy, John D; Giguere, Patrick M; Zhu, Hu; Kenakin, Terry; Roth, Bryan L; Kozikowski, Alan P

2016-11-10

On the basis of the structural similarity of our previous 5-HT 2C agonists with the melatonin receptor agonist tasimelteon and the putative biological cross-talk between serotonergic and melatonergic systems, a series of new (2,3-dihydro)benzofuran-based compounds were designed and synthesized. The compounds were evaluated for their selectivity toward 5-HT 2A , 5-HT 2B , and 5-HT 2C receptors in the calcium flux assay with the ultimate goal to generate selective 5-HT 2C agonists. Selected compounds were studied for their functional selectivity by comparing their transduction efficiency at the G protein signaling pathway versus β-arrestin recruitment. The most functionally selective compound (+)-7e produced weak β-arrestin recruitment and also demonstrated less receptor desensitization compared to serotonin in both calcium flux and phosphoinositide (PI) hydrolysis assays. We report for the first time that selective 5-HT 2C agonists possessing weak β-arrestin recruitment can produce distinct receptor desensitization properties.

(Cryptand-222)potassium(+) (hydrogensulfido)[5,10,15,20-tetra­kis(2-pival­amido­phen­yl)porphyrinato]ferrate(II)

PubMed Central

Dhifet, Mondher; Belkhiria, Mohamed Salah; Daran, Jean-Claude; Nasri, Habib

2009-01-01

As part of a systematic investigation for a number of FeII porphyrin complexes used as biomimetic models for cytochrome P450, crystals of the title compound, [K(C18H36N2O6)][FeII(C64H64N8O4)(HS)], were prepared. The compound exhibits a non-planar conformation with major ruffling and saddling distortions. The average equatorial iron–pyrrole N atom [Fe—Np = 2.102 (2) Å] bond length and the distance between the FeII atom and the 24-atom core of the porphyrin ring (Fe—PC= 0.558 Å) are typical for high-spin iron(II) penta­coordinate porphyrinates. One of the tert-butyl groups in the structure is disordered over two sets with occupancies of 0.84 and 0.16. PMID:21583412

Bioactive metabolites from an endophytic Cryptosporiopsis sp. inhabiting Clidemia hirta.

PubMed

Zilla, Mahesh K; Qadri, Masroor; Pathania, Anup S; Strobel, Gary A; Nalli, Yedukondalu; Kumar, Sunil; Guru, Santosh K; Bhushan, Shashi; Singh, Sanjay K; Vishwakarma, Ram A; Riyaz-Ul-Hassan, Syed; Ali, Asif

2013-11-01

An endophytic Cryptosporiopsis sp. was isolated from Clidemia hirta and analyzed for its secondary metabolites that lead to the isolation of three bioactive molecules. The compounds were purified from the culture broth of the fungus and their structures were determined by spectroscopic methods as (R)-5-hydroxy-2-methylchroman-4-one (1), 1-(2,6-dihydroxyphenyl)pentan-1-one (2) and (Z)-1-(2-(2-butyryl-3-hydroxyphenoxy)-6-hydroxyphenyl)-3-hydroxybut-2-en-1-one (3). Compound 1 exhibited significant cytotoxic activity against the human leukemia cell line, HL-60 with an IC50 of 4 μg/ml. This compound induced G2 arrest of the HL-60 cell cycle significantly. In addition, out of these compounds, 2 and 3 were active against several bacterial pathogens. Compound 2 was active against Bacillus cereus, Escherichia coli and Staphylococcus aureus with IC50 values varying from 18 to 30 μg/ml, and compound 3 displayed activity against Pseudomonas fluorescens with an IC50 value of 6 μg/ml. Compounds 2 and 3 are novel whereas compound 1 was reported earlier but the stereochemistry of its C-2 methyl is established for the first time. Copyright © 2013 Elsevier Ltd. All rights reserved.

(S)-N-{1-[5-(4-Chloro-benzyl-sulfanyl)-1,3,4-oxadiazol-2-yl]eth-yl}-4-methyl-benzene-sulfonamide.

PubMed

Syed, Tayyaba; Hameed, Shahid; Jones, Peter G

2011-10-01

The title compound, C(18)H(18)ClN(3)O(3)S(2), adopts by folding the form of a distorted disc. Inter-planar angles are 29.51 (7) and 63.43 (7)° from the five-membered ring to the aromatic systems and 34.80 (6)° between these two latter rings. The absolute configuration was confirmed by determination of the Flack parameter. In the crystal, the mol-ecules are linked by four hydrogen bonds, one classical (N-H⋯N) and three 'weak' (C-H⋯O), forming layers parallel to the ac plane; these are in turn linked in the third dimension by Cl⋯N [3.1689 (16) Å] and Cl⋯O [3.3148 (13) Å] contacts to the heterocyclic ring.

Trans-hemispheric contribution of C2-C10 α, ω-dicarboxylic acids, and related polar compounds to water-soluble organic carbon in the western Pacific aerosols in relation to photochemical oxidation reactions

NASA Astrophysics Data System (ADS)

SempéRé, Richard; Kawamura, Kimitaka

2003-06-01

Marine aerosol samples were collected during a western Pacific cruise covering the latitude range between 35°N and 40°S (140°E-180°E). They were analyzed for total carbon (TC), total nitrogen (TN), water-soluble organic carbon (WSOC) along with the molecular distributions of C2-C10 α, ω-dicarboxylic acids, and related polar compounds, mainly, ω-oxocarboxylic acids (C2-C9) and α-dicarbonyls (C2-C3). Oxalic acid (C2) was the most abundant followed by malonic (C3) and succinic (C4) acids. The total diacid concentration range was 7-605 ng m-3 (av. 85 ng m-3) and the diacid-carbon accounted for 2-15% (average 8%) of WSOC which comprised 29-55% (average 40%) of TC. Dry depositions of total diacids over the northern and southern Pacific Ocean were estimated to be 256-1907 μg m-2 yr-1 (average 735; n = 4) and 22-396 μg m-2 yr-1 (average 134; n = 14), respectively, whereas the air-to-sea flux of oxalic acid was 18-1351 μg m-2 yr-1 (average 466 μg m-2 yr-1) and 7.5-275 μg m-2 yr-1 (average 75 μg m-2 yr-1) in the Northern and Southern Hemispheres. We observed that the concentration ratios of diacid-C/WSOC, azelaic acid (C9)/ω-oxononanoic acid, maleic acid (iC4cis)/fumaric (iC4trans) acid and succinic acid (C4)/total diacids were correlated with air temperature. These findings showed that the intensity of photochemical oxidation reactions and thus the variation in sunlight intensity characterized here by air temperature, significantly control the molecular distribution of water-soluble organic compounds during the long-range transport of anthropogenic and/or biogenic higher molecular weight organic compounds.

Antioxidant compounds, antioxidant activity and phenolic content in peel from three tropical fruits from Yucatan, Mexico.

PubMed

Moo-Huchin, Víctor M; Moo-Huchin, Mariela I; Estrada-León, Raciel J; Cuevas-Glory, Luis; Estrada-Mota, Iván A; Ortiz-Vázquez, Elizabeth; Betancur-Ancona, David; Sauri-Duch, Enrique

2015-01-01

The aim of this study was to determine the antioxidant compounds, antioxidant activity and content of individual phenolic compounds of freeze-dried peel from three tropical fruits grown in Yucatan, México: purple star apple (Chrysophyllum cainito L.), yellow cashew and red cashew (Anacardium occidentale). The freeze-dried peels were good source of antioxidant compounds. ABTS and DPPH values in the peel from each fruit were 3050.95-3322.31 μM Trolox/100g dry weight (DW) or 890.19-970.01 mg of vitamin C/100 g DW, and 1579.04-1680.90 μM Trolox/100 g DW or 340.18-362.18 mg of vitamin C/100 g DW, respectively. Six phenolic compounds were identified in the peel from the tropical fruits studied: ferulic, caffeic, sinapic, gallic, ellagic and myricetin. This study demonstrated that freeze-dried peels from purple star apple, yellow cashew and red cashew, could serve as potential sources of antioxidants for use in food and pharmaceutical industries. Copyright © 2014 Elsevier Ltd. All rights reserved.

Evaluation of an amide-based stationary phase for supercritical fluid chromatography

PubMed Central

Borges-Muñoz, Amaris C.; Colón, Luis A.

2017-01-01

A relatively new stationary phase containing a polar group embedded in a hydrophobic backbone (i.e., ACE® C18-amide) was evaluated for use in supercritical fluid chromatography. The amide-based column was compared with columns packed with bare silica, C18 silica, and a terminal-amide silica phase. The system was held at supercritical pressure and temperature with a mobile phase composition of CO2 and methanol as cosolvent. The linear solvation energy relationship model was used to evaluate the behavior of these stationary phases, relating the retention factor of selected probes to specific chromatographic interactions. A five-component test mixture, consisting of a group of drug-like molecules was separated isocratically. The results show that the C18-amide stationary phase provided a combination of interactions contributing to the retention of the probe compounds. The hydrophobic interactions are favorable; however, the electron donating ability of the embedded amide group shows a large positive interaction. Under the chromatographic conditions used, the C18-amide column was able to provide baseline resolution of all the drug-like probe compounds in a text mixture, while the other columns tested did not. PMID:27396487

Different molecular conformations co-exist in each of three 2-aryl-N-(1,5-dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol-4-yl)acetamides: hydrogen bonding in zero, one and two dimensions.

PubMed

Narayana, Badiadka; Yathirajan, Hemmige S; Rathore, Ravindranath S; Glidewell, Christopher

2016-09-01

4-Antipyrine [4-amino-1,5-dimethyl-2-phenyl-1H-pyrazol-3(2H)-one] and its derivatives exhibit a range of biological activities, including analgesic, antibacterial and anti-inflammatory, and new examples are always of potential interest and value. 2-(4-Chlorophenyl)-N-(1,5-dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol-4-yl)acetamide, C19H18ClN3O2, (I), crystallizes with Z' = 2 in the space group P\\overline{1}, whereas its positional isomer 2-(2-chlorophenyl)-N-(1,5-dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol-4-yl)acetamide, (II), crystallizes with Z' = 1 in the space group C2/c; the molecules of (II) are disordered over two sets of atomic sites having occupancies of 0.6020 (18) and 0.3980 (18). The two independent molecules of (I) adopt different molecular conformations, as do the two disorder components in (II), where the 2-chlorophenyl substituents adopt different orientations. The molecules of (I) are linked by a combination of N-H...O and C-H...O hydrogen bonds to form centrosymmetric four-molecule aggregates, while those of (II) are linked by the same types of hydrogen bonds forming sheets. The related compound N-(1,5-dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol-4-yl)-2-(3-methoxyphenyl)acetamide, C20H21N3O3, (III), is isomorphous with (I) but not strictly isostructural; again the two independent molecules adopt different molecular conformations, and the molecules are linked by N-H...O and C-H...O hydrogen bonds to form ribbons. Comparisons are made with some related structures, indicating that a hydrogen-bonded R2(2)(10) ring is the common structural motif.

Ethyl 4,4''-difluoro-5'-meth-oxy-1,1':3',1''-terphenyl-4'-carboxyl-ate.

PubMed

Fun, Hoong-Kun; Chia, Tze Shyang; Samshuddin, S; Narayana, B; Sarojini, B K

2012-01-01

In the title compound, C(22)H(18)F(2)O(3), the two fluoro-substituted rings form dihedral angles of 25.89 (15) and 55.00 (12)° with the central benzene ring. The eth-oxy group in the mol-ecule is disordered over two positions with a site-occupancy ratio of 0.662 (7):0.338 (7). In the crystal, mol-ecules are linked by C-H⋯O hydrogen bonds into chains along the a axis. The crystal packing is further stabilized by C-H⋯π and π-π inter-actions, with centroid-centroid distances of 3.8605 (15) Å.

Simultaneous Determination of Perfluorinated Compounds in Edible Oil by Gel-Permeation Chromatography Combined with Dispersive Solid-Phase Extraction and Liquid Chromatography-Tandem Mass Spectrometry.

PubMed

Yang, Lili; Jin, Fen; Zhang, Peng; Zhang, Yanxin; Wang, Jian; Shao, Hua; Jin, Maojun; Wang, Shanshan; Zheng, Lufei; Wang, Jing

2015-09-30

A simple analytical method was developed for the simultaneous analysis of 18 perfluorinated compounds (PFCs) in edible oil. The target compounds were extracted by acetonitrile, purified by gel permeation chromatography (GPC) and dispersive solid-phase extraction (DSPE) using graphitized carbon black (GCB) and octadecyl (C18), and analyzed by liquid chromatography-electrospray ionization tandem mass spectrometry (LC-ES-MS/MS) in negative ion mode. Recovery studies were performed at three fortification levels. The average recoveries of all target PFCs ranged from 60 to 129%, with an acceptable relative standard deviation (RSD) (1-20%, n = 3). The method detection limits (MDLs) ranged from 0.004 to 0.4 μg/kg, which was significantly improved compared with the existing liquid-liquid extraction and cleanup method. The method was successfully applied for the analysis of all target PFCs in edible oil samples collected from markets in Beijing, China, and the results revealed that C6-C10 perfluorocarboxylic acid (PFCAs) and C7 perfluorosulfonic acid PFSAs were the major PFCs detected in oil samples.

Tri-p-tolyl­phosphine

PubMed Central

Wang, Hao; Wang, Yi-Bin; Liu, Bo-Nian; Tang, Shi-Gui; Wei, Ping

2008-01-01

In the title compound C21H21P, the P atom is situated on a crystallographic threefold rotatory-inversion axis, resulting in threefold rotation symmetry of the title compound. The dihedral angles between the symmetry-related benzene rings are 87.40 (18)°. PMID:21201763

Drying effect on flavonoid composition and antioxidant activity of immature kumquat.

PubMed

Lou, Shyi-Neng; Lai, Yi-Chun; Huang, Jia-De; Ho, Chi-Tang; Ferng, Lin-Huei A; Chang, Yung-Chung

2015-03-15

A seven flavonoids in hot water extract of immature kumquat (Citrus japonica var. margarita) were identified and quantified (mg/100g fresh fruit): 3',5'-di-C-β-glucopyranosylphloretin (DGPP, 285.9 ± 2.9 mg/100g), acacetin 8-C-neohesperidoside (margaritene, 136.2 ± 2.6 mg/100g), acacetin 6-C-neohesperidoside (isomargaritene, 119.1 ± 1.8 mg/100g), fortunellin (acacetin 7-O-neohesperidoside, 28.5 ± 0.7 mg/100g), apigenin 8-C-neohesperidoside (16.9 ± 0.1mg/100g), poncirin (isosakuranetin 7-O-neohesperidoside, 5.1 ± 0.1mg/100g), and rhoifolin (apigenin 7-O-neohesperidoside, 2.0 ± 0.1mg/100g). When immature kumquat was dried at 110 and 130°C for 0.5h, the antioxidant activity, total phenolic content and identified flavonoids increased. The UV absorbance of browning products of immature kumquat dried at 130°C for 1.5h increased dramatically, while the identified flavonoids decreased. Therefore, it was concluded that drying below 130°C for 1.0 h, could release phenolic compounds, which resulted in the increasing antioxidant activity. Drying at 130°C for 1.5h, it might be due to the effect of formed browning products. Copyright © 2014 Elsevier Ltd. All rights reserved.

Tracing C Fluxes From Leaf Litter To Microbial Respired CO2 And Specific Soil Compounds

NASA Astrophysics Data System (ADS)

Rubino, M.; Lubritto, C.; D'Onofrio, A.; Gleixner, G.; Terrasi, F.; Cotrufo, F. M.

2004-12-01

Despite litter decomposition is one of the major process controlling soil C stores and nutrient cycling, yet C dynamics during litter decay are poorly understood and quantified. Here we report the results of a laboratory experiment where 13C depleted leaf litter was incubated on a 13C enriched soil with the aims to: i) partition the C loss during litter decay into microbial respired-CO2 and C input into the soil; ii) identify the soil compounds where litter derived C is retained; iii) assess whether litter quality is a determinant of both the above processes. Three 13C-depleted leaf litter(delta13C ca. -43), differing in their degradability, were incubated on C4 soil (delta13C ca. -18) under laboratory controlled conditions for 8 months, with litter respiration and delta13C-CO2 being measured at regular intervals. At harvest, Compound Specific Isotope Analyses was performed on soil and litter samples in order to follow the fate of litter-derived C compounds in the various pools of SOMƒn The delta13C of soils carbohydrates, alkanes and Phospho Lipids Fatty Acids (PLFA) were measured, and the mixing model approach used to quantify the contribution of litter derived C to the specific compounds.

Low resistance ohmic contacts to n-GaN and n-AlGaN using NiAl

NASA Astrophysics Data System (ADS)

Ingerly, D. B.; Chen, Y.; William, R. S.; Takeuchi, T.; Chang, Y. A.

2000-07-01

The intermetallic compound NiAl (50:50 at. %) has been shown to be a low-resistance ohmic contact to n-GaN and n-AlGaN. NiAl contacts on n-GaN (n=2.5×1017cm-3) had a specific contact resistance of 9.4×10-6 Ω cm2 upon annealing at 850 °C for 5 min. NiAl contacts annealed at 900 °C for 5 min in n-Al0.12Ga0.88N (n=2.4×1018cm-3) and n-Al0.18Ga0.82N (n=2.7×1018cm-3) had specific contact resistances of 2.1×10-5 Ω cm2 and 4.7×10-5 Ω cm2, respectively. Additionally, these contacts were subjected to long-term annealing at 600 °C for 100 h. On n-GaN, the contact specific contact resistance degraded from 9.4×10-6 Ω cm2 to 5.3×10-5 Ω cm2 after the long-term anneal. Contacts to n-Al0.18Ga0.82N showed only slight degradation with a change in contact resistance, from 4.7×10-5 Ω cm2 to 9.2×10-5 Ω cm2. These results demonstrate the NiAl has great promise as a stable, low-resistance contact, particularly to n-AlGaN used in high-temperature applications.

Simultaneous determination of 11 antibiotics and their main metabolites from four different groups by reversed-phase high-performance liquid chromatography-diode array-fluorescence (HPLC-DAD-FLD) in human urine samples.

PubMed

Fernandez-Torres, R; Consentino, M Olías; Lopez, M A Bello; Mochon, M Callejon

2010-05-15

A new, accurate and sensitive reversed-phase high-performance liquid chromatography (RP-HPLC) as analytical method for the quantitative determination of 11 antibiotics (drugs) and the main metabolites of five of them present in human urine has been worked out, optimized and validated. The analytes belong to four different groups of antibiotics (sulfonamides, tetracyclines, penicillins and anphenicols). The analyzed compounds were sulfadiazine (SDI) and its N(4)-acetylsulfadiazine (NDI) metabolite, sulfamethazine (SMZ) and its N(4)-acetylsulfamethazine (NMZ), sulfamerazine (SMR) and its N(4)-acetylsulfamerazine (NMR), sulfamethoxazole (SMX), trimetroprim (TMP), amoxicillin (AMX) and its main metabolite amoxicilloic acid (AMA), ampicillin (AMP) and its main metabolite ampicilloic acid (APA), chloramphenicol (CLF), thiamphenicol (TIF), oxytetracycline (OXT) and chlortetracycline (CLT). For HPLC analysis, diode array (DAD) and fluorescence (FLD) detectors were used. The separation of the analyzed compounds was conducted by means of a Phenomenex Gemini C(18) (150mm x 4.6mm I.D., particle size 5microm) analytical column with LiChroCART LiChrospher C(18) (4mm x 4mm, particle size 5microm) guard column. Analyzed drugs were determined within 34min using formic acid 0.1% in water and acetonitrile in gradient elution mode as mobile phase. A linear response was observed for all compounds in the range of concentration studied. Two procedures were optimized for sample preparation: a direct treatment with methanol and acetonitrile and a solid phase extraction procedure using Bond Elut Plexa columns. The method was applied to the determination of the analytes in human urine from volunteers under treatment with different pharmaceutical formulations. This method can be successfully applied to routine determination of all these drugs in human urine samples.

Synthesis, molecular properties prediction and cytotoxic screening of 3-(2-aryl-2-oxoethyl)isobenzofuran-1(3H)-ones.

PubMed

da Silva Maia, Angélica Faleiros; Siqueira, Raoni Pais; de Oliveira, Fabrício Marques; Ferreira, Joana Gasperazzo; da Silva, Silma Francielle; Caiuby, Clarice Alves Dale; de Oliveira, Leandro Licursi; de Paula, Sérgio Oliveira; Souza, Rafael Aparecido Carvalho; Guilardi, Silvana; Bressan, Gustavo Costa; Teixeira, Róbson Ricardo

2016-06-15

In the present investigation, a collection of nineteen 3-(2-aryl-2-oxoethyl)isobenzofuran-1(3H)-ones was synthesized and screened for their cytotoxic activity against a panel of three leukemia cancer cell lines. The compounds were prepared via ZrOCl2·8H2O catalyzed condensation reactions between phthalaldehydic acid and different acetophenones. The reactions were carried out free of solvent and the isobenzofuran-1(3H)-ones were obtained in good yields (80-92%). The identities of the synthesized compounds were confirmed upon IR and NMR ((1)H and (13)C) spectroscopy as well as high resolution mass spectrometry analyses. Structures of compounds 1, 4 and 16 were also investigated by X-ray analysis. The synthesized compounds were submitted to in vitro bioassays against HL-60, K562 and NALM6 cancer cell lines using MTT cytotoxicity assay. After 48h of treatment, twelve derivatives were able to reduce cell viability and presented IC50 values equal to or below 20μmolL(-1) against at least one of the evaluated lineages. The most active compound corresponded to 3-(3-methylphenyl-2-oxoethyl)isobenzofuran-1(3H)-one (18) (IC50 values obtained for HL-60, K562 and NALM6 were, respectively, 13.5μmolL(-1), 8.83μmolL(-1), and 5.24μmolL(-1)). In addition, compound 18 was capable of triggering apoptosis on NALM6 cells. All isobenzofuranones herein evaluated did not present cytotoxicity on peripheral blood mononuclear cells (PBMC), suggesting selective cytotoxic effect on leukemic cells. A computational study allowed prediction of pharmacokinetics and drug-likeness properties of the synthesized compounds. DFT calculations were performed to obtain the energy values of HOMO, LUMO, and dipole moments of isobenzofuranones. Copyright © 2016 Elsevier Ltd. All rights reserved.

Synthesis and fundamental properties of stable Ph(3)SnSiH(3) and Ph(3)SnGeH(3) hydrides: model compounds for the design of Si-Ge-Sn photonic alloys.

PubMed

Tice, Jesse B; Chizmeshya, Andrew V G; Groy, Thomas L; Kouvetakis, John

2009-07-06

The compounds Ph(3)SnSiH(3) and Ph(3)SnGeH(3) (Ph = C(6)H(5)) have been synthesized as colorless solids containing Sn-MH(3) (M = Si, Ge) moieties that are stable in air despite the presence of multiple and highly reactive Si-H and Ge-H bonds. These molecules are of interest since they represent potential model compounds for the design of new classes of IR semiconductors in the Si-Ge-Sn system. Their unexpected stability and high solubility also makes them a safe, convenient, and potentially useful delivery source of -SiH(3) and -GeH(3) ligands in molecular synthesis. The structure and composition of both compounds has been determined by chemical analysis and a range of spectroscopic methods including multinuclear NMR. Single crystal X-ray structures were determined and indicated that both compounds condense in a Z = 2 triclinic (P1) space group with lattice parameters (a = 9.7754(4) A, b = 9.8008(4) A, c = 10.4093(5) A, alpha = 73.35(10)(o), beta = 65.39(10)(o), gamma = 73.18(10)(o)) for Ph(3)SnSiH(3) and (a = 9.7927(2) A, b = 9.8005(2) A, c = 10.4224(2) A, alpha = 74.01(3)(o), beta = 65.48(3)(o), gamma = 73.43(3)(o)) for Ph(3)SnGeH(3). First principles density functional theory simulations are used to corroborate the molecular structures of Ph(3)SnSiH(3) and Ph(3)SnGeH(3), gain valuable insight into the relative stability of the two compounds, and provide correlations between the Si-Sn and Ge-Sn bonds in the molecules and those in tetrahedral Si-Ge-Sn solids.

Sampling of trace volatile metal(loid) compounds in ambient air using polymer bags: a convenient method.

PubMed

Haas, K; Feldmann, J

2000-09-01

The sampling of volatile metal(loid) compounds (VOMs) such as hydrides, methylated, and permethylated species of arsenic, antimony, and tin is described using Tedlar bags. Advantages as well as limitations and constraints are discussed and compared to other widely used sampling techniques within this area, namely, stainless steel canisters, cryotrapping, and solid adsorbent cartridges. To prove the suitability of Tedlar bags for the sampling of volatile metal(loid) compounds, series of stability tests have been run using both laboratory synthetic and real samples analyzed periodically after increasing periods of storage. The samples have been stored in the dark at 20 degrees C and at 50 degrees C. Various volatile arsenic species (AsH3, MeAsH2, Me2AsH, Me3As), tin species (SnH4, MeSnH3, Me2SnH2, Me3SnH, Me4Sn, BuSnH3), and antimony species (SbH3, MeSbH2, Me2SbH, Me3Sb) have been generated using hydride generation methodology and mixed with moisturized air. Three static gaseous atmospheres with concentrations of 0.3-18 ng/L for the various compounds have been generated in Tedlar bags, and the stability of the VOMs has been monitored over a period of 5 weeks. Sewage sludge digester gas samples have been stored only at 20 degrees C for a period of 48 h. Cryotrapping GC/ICPMS has been used for the determination of the VOMs with a relative standard deviation of 5% for 100 pg. After 8 h, the recovery rate of all the compounds in the air atmospheres was better than 95% at 20 and 50 degrees C, whereas the recovery after 24 h was found to be between 81 and 99% for all VOMs at 20 and 50 degrees C except for Me3Sb and Me3As. These species show a loss between 48 and 73% at both temperatures. After 5 weeks at 20 degrees C, a loss of only 25-50% for arsine and stibine and the above-mentioned tin compounds was determined. Only Me3Sb, Me3Bi, and Me2Te were present in the digester gas sample. After 24 h, losses of 44, 10, and 12%, respectively, could be determined. Given these results, Tedlar bags could even be used, with some limitations, for long-term sampling of air containing traces of VOMs. The loss is more pronounced at higher temperatures.

MUSCLE EQUIVALENT MATERIAL

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

Kawashima, K.; Takaku, Y.; Inada, T.

1961-01-01

A tissue-equivalent material was constructed from the following components: polyethylene (CH/sub 2/)/sub n/, 71.4% (by weight), NaNO/sub 3/ 21.3%, Al/sub 2/O/sub 3/ 5.5%, and TiC/sub 2/ 1.8%. The attenuation coefficients of this solid compound, Mix. p in x or gamma rays (40kev --1.25 Mev), were shown to be equal to those of a section of pork loin (m. longissimus dorsi). Thus, Mix. p is concluded to be good phantom material for depth dose measuremeat and suitable material for walls of ionizatlon chambers. (Abstr. Japan Med., 2: No. 3, March 1962)

Silica-based ionic liquid coating for 96-blade system for extraction of aminoacids from complex matrixes.

PubMed

Mousavi, Fatemeh; Pawliszyn, Janusz

2013-11-25

1-Vinyl-3-octadecylimidazolium bromide ionic liquid [C18VIm]Br was prepared and used for the modification of mercaptopropyl-functionalized silica (Si-MPS) through surface radical chain-transfer addition. The synthesized octadecylimidazolium-modified silica (SiImC18) was characterized by thermogravimetric analysis (TGA), infrared spectroscopy (IR), (13)C NMR and (29)Si NMR spectroscopy and used as an extraction phase for the automated 96-blade solid phase microextraction (SPME) system with thin-film geometry using polyacrylonitrile (PAN) glue. The new proposed extraction phase was applied for extraction of aminoacids from grape pulp, and LC-MS-MS method was developed for separation of model compounds. Extraction efficiency, reusability, linearity, limit of detection, limit of quantitation and matrix effect were evaluated. The whole process of sample preparation for the proposed method requires 270min for 96 samples simultaneously (60min preconditioning, 90min extraction, 60min desorption and 60min for carryover step) using 96-blade SPME system. Inter-blade and intra-blade reproducibility were in the respective ranges of 5-13 and 3-10% relative standard deviation (RSD) for all model compounds. Limits of detection and quantitation of the proposed SPME-LC-MS/MS system for analysis of analytes were found to range from 0.1 to 1.0 and 0.5 to 3.0μgL(-1), respectively. Standard addition calibration was applied for quantitative analysis of aminoacids from grape juice and the results were validated with solvent extraction (SE) technique. Copyright © 2013 Elsevier B.V. All rights reserved.

Studies on interaction of insect repellent compounds with odorant binding receptor proteins by in silico molecular docking approach.

PubMed

Gopal, J Vinay; Kannabiran, K

2013-12-01

The aim of the study was to identify the interactions between insect repellent compounds and target olfactory proteins. Four compounds, camphor (C10H16O), carvacrol (C10H14O), oleic acid (C18H34O2) and firmotox (C22H28O5) were chosen as ligands. Seven olfactory proteins of insects with PDB IDs: 3K1E, 1QWV, 1TUJ, 1OOF, 2ERB, 3R1O and OBP1 were chosen for docking analysis. Patch dock was used and pymol for visualizing the structures. The interactions of these ligands with few odorant binding proteins showed binding energies. The ligand camphor had showed a binding energy of -136 kcal/mol with OBP1 protein. The ligand carvacrol interacted with 1QWV and 1TUJ proteins with a least binding energy of -117.45 kcal/mol and -21.78 kcal/mol respectively. The ligand oleic acid interacted with 1OOF, 2ERB, 3R1O and OBP1 with least binding energies. Ligand firmotox interacted with OBP1 and showed least binding energies. Three ligands (camphor, oleic acid and firmotox) had one, two, three interactions with a single protein OBP1 of Nilaparvatha lugens (Rice pest). From this in silico study we identified the interaction patterns for insect repellent compounds with the target insect odarant proteins. The results of our study revealed that the chosen ligands showed hydrogen bond interactions with the target olfactory receptor proteins.

Sodium Channel Nav1.8 Underlies TTX-Resistant Axonal Action Potential Conduction in Somatosensory C-Fibers of Distal Cutaneous Nerves.

PubMed

Klein, Amanda H; Vyshnevska, Alina; Hartke, Timothy V; De Col, Roberto; Mankowski, Joseph L; Turnquist, Brian; Bosmans, Frank; Reeh, Peter W; Schmelz, Martin; Carr, Richard W; Ringkamp, Matthias

2017-05-17

Voltage-gated sodium (Na V ) channels are responsible for the initiation and conduction of action potentials within primary afferents. The nine Na V channel isoforms recognized in mammals are often functionally divided into tetrodotoxin (TTX)-sensitive (TTX-s) channels (Na V 1.1-Na V 1.4, Na V 1.6-Na V 1.7) that are blocked by nanomolar concentrations and TTX-resistant (TTX-r) channels (Na V 1.8 and Na V 1.9) inhibited by millimolar concentrations, with Na V 1.5 having an intermediate toxin sensitivity. For small-diameter primary afferent neurons, it is unclear to what extent different Na V channel isoforms are distributed along the peripheral and central branches of their bifurcated axons. To determine the relative contribution of TTX-s and TTX-r channels to action potential conduction in different axonal compartments, we investigated the effects of TTX on C-fiber-mediated compound action potentials (C-CAPs) of proximal and distal peripheral nerve segments and dorsal roots from mice and pigtail monkeys ( Macaca nemestrina ). In the dorsal roots and proximal peripheral nerves of mice and nonhuman primates, TTX reduced the C-CAP amplitude to 16% of the baseline. In contrast, >30% of the C-CAP was resistant to TTX in distal peripheral branches of monkeys and WT and Na V 1.9 -/- mice. In nerves from Na V 1.8 -/- mice, TTX-r C-CAPs could not be detected. These data indicate that Na V 1.8 is the primary isoform underlying TTX-r conduction in distal axons of somatosensory C-fibers. Furthermore, there is a differential spatial distribution of Na V 1.8 within C-fiber axons, being functionally more prominent in the most distal axons and terminal regions. The enrichment of Na V 1.8 in distal axons may provide a useful target in the treatment of pain of peripheral origin. SIGNIFICANCE STATEMENT It is unclear whether individual sodium channel isoforms exert differential roles in action potential conduction along the axonal membrane of nociceptive, unmyelinated peripheral nerve fibers, but clarifying the role of sodium channel subtypes in different axonal segments may be useful for the development of novel analgesic strategies. Here, we provide evidence from mice and nonhuman primates that a substantial portion of the C-fiber compound action potential in distal peripheral nerves, but not proximal nerves or dorsal roots, is resistant to tetrodotoxin and that, in mice, this effect is mediated solely by voltage-gated sodium channel 1.8 (Na V 1.8). The functional prominence of Na V 1.8 within the axonal compartment immediately proximal to its termination may affect strategies targeting pain of peripheral origin. Copyright © 2017 the authors 0270-6474/17/375205-11$15.00/0.

Synthesis of Amide and Ester Derivatives of Cinnamic Acid and Its Analogs: Evaluation of Their Free Radical Scavenging and Monoamine Oxidase and Cholinesterase Inhibitory Activities.

PubMed

Takao, Koichi; Toda, Kazuhiro; Saito, Takayuki; Sugita, Yoshiaki

2017-01-01

A series of cinnamic acid derivatives, amides (1-12) and esters (13-22), were synthesized, and structure-activity relationships for antioxidant activity, and monoamine oxidases (MAO) A and B, acetylcholinesterase, and butyrylcholinesterase (BChE) inhibitory activities were analyzed. Among the synthesized compounds, compounds 1-10, 12-18, and rosmarinic acid (23), which contained catechol, o-methoxyphenol or 5-hydroxyindole moieties, showed potent 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging activity. Compounds 9-11, 15, 17-22 showed potent and selective MAO-B inhibitory activity. Compound 20 was the most potent inhibitor of MAO-B. Compounds 18 and 21 showed moderate BChE inhibitory activity. In addition, compound 18 showed potent antioxidant activity and MAO-B inhibitory activity. In a comparison of the cinnamic acid amides and esters, the amides exhibited more potent DPPH free radical scavenging activity, while the esters showed stronger inhibitory activities against MAO-B and BChE. These results suggested that cinnamic acid derivatives such as compound 18, p-coumaric acid 3,4-dihydroxyphenethyl ester, and compound 20, p-coumaric acid phenethyl ester, may serve as lead compounds for the development of novel MAO-B inhibitors and candidate lead compounds for the prevention or treatment of Alzheimer's disease.

Biofuel production and phycoremediation by Chlorella sp. ISTLA1 isolated from landfill site.

PubMed

Mishra, Arti; Medhi, Kristina; Maheshwari, Neha; Srivastava, Shaili; Thakur, Indu Shekhar

2018-04-01

The present study aims to investigate the biofuel production ability and potential of heavy metal remediation of Chlorella sp. ISTLA1 isolated from a landfill site. The strain was cultured in Bold's Basal medium at different concentration of NaHCO 3 and pH. Response surface methodology was employed for the optimization of nutrient sources for higher lipid production. Under the optimized conditions, the yield of lipid and biomass was 365.42 and 833.14 mg L -1 respectively. GC-MS analysis of lipid indicated the presence of C 8 to C 31 organic compounds consisting mainly of palmitic acid (C16:0), stearic acid (C18:0) and oleic acid (C18:1). Additionally, remediation of heavy metals like Zn, Cu, Mn and Fe from waste water was observed by AAS and EDX. The removal efficiency was 82.6% for Zn, 56.5% for Cu, 79.8% for Mn and 40% for Fe. The study revealed simultaneous biodiesel production and waste water treatment by Chlorella sp. ISTLA1. Copyright © 2017 Elsevier Ltd. All rights reserved.

Phytotoxic Effects and Phytochemical Fingerprinting of Hydrodistilled Oil, Enriched Fractions, and Isolated Compounds Obtained from Cryptocarya massoy (Oken) Kosterm. Bark.

PubMed

Rolli, Enrico; Marieschi, Matteo; Maietti, Silvia; Guerrini, Alessandra; Grandini, Alessandro; Sacchetti, Gianni; Bruni, Renato

2016-01-01

The hydrodistilled oil of Cryptocarya massoy bark was characterized by GC-FID and GC/MS analyses, allowing the identification of unusual C10 massoia lactone (3, 56.2%), C12 massoia lactone (4, 16.5%), benzyl benzoate (1, 12.7%), C8 massoia lactone (3.4%), δ-decalactone (5, 1.5%), and benzyl salicylate (2, 1.8%) as main constituents. The phytotoxic activities of the oil, three enriched fractions (lactone-rich, ester-rich, and sesquiterpene-rich), and four constituents (compounds 1, 2, 5, and δ-dodecalactone (6)) against Lycopersicon esculentum and Cucumis sativus seeds and seedlings were screened. At a concentration of 1000 μl/l, the essential oil and the massoia lactone-rich fraction caused a complete inhibition of the germination of both seeds, and, when applied on tomato plantlets, they induced an 85 and 100% dieback, respectively. These performances exceeded those of the well-known phytotoxic essential oils of Syzygium aromaticum and Cymbopogon citratus, already used in commercial products for the weed and pest management. The same substances were also evaluated against four phytopathogenic bacteria and ten phytopathogenic fungi, providing EC50 values against the most susceptible strains in the 100-500 μl/l range for the essential oil and in the 10-50 μl/l range for compound 6 and the lactone-rich fraction. The phytotoxic behavior was related mainly to massoia lactones and benzyl esters, while a greater amount of 6 may infer a good activity against some phytopathogenic fungi. Further investigations of these secondary metabolites are warranted, to evaluate their use as natural herbicides. Copyright © 2016 Verlag Helvetica Chimica Acta AG, Zürich.

Comparative Toxicity of Halogenated Hydrocarbons: Molecular Aspects

DTIC Science & Technology

1993-07-13

peroxisome proliferators, namely perfluorooctanoic acid ( PFOA ), perfluorodecanoic acid ( PFDA ) and the tri-and tetra-oligomers of chlorotrifluooethylene...ACID ( PFOA ), PERFLUORO - DECANOIC ACID ( PFDA ) AND THE TRI-AND TETRA-OLIGOMERS OF CHLORO -TR.tLUORO ETHYLENE (CTFE) HAVE BEEN INVESTIGATED IN THE RAT AND...AVAILABILITY STATEMENT 12b. DISTRIBUTION CODE NO LIMITATION NOT KNOWN 13. ABSTRACT (Maximum 200 words) THE COMPARATIVE HEPATOTOXICITIES OF PERFLUOROOCTANOIC

Serendipitous discovery of light-induced (In Situ) formation of an Azo-bridged dimeric sulfonated naphthol as a potent PTP1B inhibitor.

PubMed

Bongard, Robert D; Lepley, Michael; Thakur, Khushabu; Talipov, Marat R; Nayak, Jaladhi; Lipinski, Rachel A Jones; Bohl, Chris; Sweeney, Noreena; Ramchandran, Ramani; Rathore, Rajendra; Sem, Daniel S

2017-05-31

Protein tyrosine phosphatases (PTPs) like dual specificity phosphatase 5 (DUSP5) and protein tyrosine phosphatase 1B (PTP1B) are drug targets for diseases that include cancer, diabetes, and vascular disorders such as hemangiomas. The PTPs are also known to be notoriously difficult targets for designing inihibitors that become viable drug leads. Therefore, the pipeline for approved drugs in this class is minimal. Furthermore, drug screening for targets like PTPs often produce false positive and false negative results. Studies presented herein provide important insights into: (a) how to detect such artifacts, (b) the importance of compound re-synthesis and verification, and (c) how in situ chemical reactivity of compounds, when diagnosed and characterized, can actually lead to serendipitous discovery of valuable new lead molecules. Initial docking of compounds from the National Cancer Institute (NCI), followed by experimental testing in enzyme inhibition assays, identified an inhibitor of DUSP5. Subsequent control experiments revealed that this compound demonstrated time-dependent inhibition, and also a time-dependent change in color of the inhibitor that correlated with potency of inhibition. In addition, the compound activity varied depending on vendor source. We hypothesized, and then confirmed by synthesis of the compound, that the actual inhibitor of DUSP5 was a dimeric form of the original inhibitor compound, formed upon exposure to light and oxygen. This compound has an IC 50 of 36 μM for DUSP5, and is a competitive inhibitor. Testing against PTP1B, for selectivity, demonstrated the dimeric compound was actually a more potent inhibitor of PTP1B, with an IC 50 of 2.1 μM. The compound, an azo-bridged dimer of sulfonated naphthol rings, resembles previously reported PTP inhibitors, but with 18-fold selectivity for PTP1B versus DUSP5. We report the identification of a potent PTP1B inhibitor that was initially identified in a screen for DUSP5, implying common mechanism of inhibitory action for these scaffolds.

Aromatic-degrading Sphingomonas isolates from the deep subsurface

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

Fredrickson, J.K.; Romine, M.F.; Balkwill, D.L.

An obligately aerobic chemoheterotrophic bacterium (strain F199) previously isolated from Southeast Coastal Plain subsurface sediments and shown to degrade toluene, naphthalene, and other aromatic compounds was characterized by analysis of its 16S rRNA nucleotide base sequence and cellular lipid composition. Strain F199 contained 2-OH14:0 and 18:1{omega}7c as the predominant cellular fatty acids and sphingolipids that are characteristic of the genus Sphingomonas. Phylogenetic analysis of its 16SrRNA sequence indicated that F199 was most closely related to Sphingomonas capsulata among the bacteria currently in the Ribosomal Database. Five additional isolates from deep Southeast Coastal Plain sediments were determined by 16S rRNA sequencemore » analysis to be closely related to F199. These strains also contained characteristic sphingolipids. Four of these five strains could also grow on a broad range of aromatic compounds and could mineralize [{sup 14C}]toluene and [{sup 14C}]naphthalene. S. capsulata (ATCC 14666), Sphingomonas paucimobiolis (ATCC 29837), and one of the subsurface isolates were unable to grow on any of the aromatic compounds or mineralize toluene or naphthalene. These results indicate that bacteria within the genus Sphingomonas are present in Southeast Coastal Plain subsurface sediments and that the capacity for degrading a broad range of substituted aromatic compounds appears to be common among Sphingomonas species from this environment. 41 refs., 2 figs., 5 tabs.« less

Methods of forming single source precursors, methods of forming polymeric single source precursors, and single source precursors formed by such methods

DOEpatents

Fox, Robert V.; Rodriguez, Rene G.; Pak, Joshua J.; Sun, Chivin; Margulieux, Kelsey R.; Holland, Andrew W.

2016-04-19

Methods of forming single source precursors (SSPs) include forming intermediate products having the empirical formula 1/2{L.sub.2N(.mu.-X).sub.2M'X.sub.2}.sub.2, and reacting MER with the intermediate products to form SSPs of the formula L.sub.2N(.mu.-ER).sub.2M'(ER).sub.2, wherein L is a Lewis base, M is a Group IA atom, N is a Group IB atom, M' is a Group IIIB atom, each E is a Group VIB atom, each X is a Group VIIA atom or a nitrate group, and each R group is an alkyl, aryl, vinyl, (per)fluoro alkyl, (per)fluoro aryl, silane, or carbamato group. Methods of forming polymeric or copolymeric SSPs include reacting at least one of HE.sup.1R.sup.1E.sup.1H and MER with one or more substances having the empirical formula L.sub.2N(.mu.-ER).sub.2M'(ER).sub.2 or L.sub.2N(.mu.-X).sub.2M'(X).sub.2 to form a polymeric or copolymeric SSP. New SSPs and intermediate products are formed by such methods.

Methods of forming single source precursors, methods of forming polymeric single source precursors, and single source precursors formed by such methods

DOEpatents

Fox, Robert V.; Rodriguez, Rene G.; Pak, Joshua J.; Sun, Chivin; Margulieux, Kelsey R.; Holland, Andrew W.

2014-09-09

Methods of forming single source precursors (SSPs) include forming intermediate products having the empirical formula 1/2{L.sub.2N(.mu.-X).sub.2M'X.sub.2}.sub.2, and reacting MER with the intermediate products to form SSPs of the formula L.sub.2N(.mu.-ER).sub.2M'(ER).sub.2, wherein L is a Lewis base, M is a Group IA atom, N is a Group IB atom, M' is a Group IIIB atom, each E is a Group VIB atom, each X is a Group VIIA atom or a nitrate group, and each R group is an alkyl, aryl, vinyl, (per)fluoro alkyl, (per)fluoro aryl, silane, or carbamato group. Methods of forming polymeric or copolymeric SSPs include reacting at least one of HE.sup.1R.sup.1E.sup.1H and MER with one or more substances having the empirical formula L.sub.2N(.mu.-ER).sub.2M'(ER).sub.2 or L.sub.2N(.mu.-X).sub.2M'(X).sub.2 to form a polymeric or copolymeric SSP. New SSPs and intermediate products are formed by such methods.

Experimental measure of retinal impact force resulting from intraocular foreign body dropped onto retina through media of differing viscosity.

PubMed

Ernst, Benjamin J; Velez-Montoya, Raul; Kujundzic, Damir; Kujundzic, Elmira; Olson, Jeffrey L

2013-07-01

To evaluate and compare the perfluorocarbon liquid, silicone oil, and viscoelastic against standard saline, in their ability to dampen the impact force of a foreign body, dropped within the eye. In an experimental surgical model in where cohesive and adhesive forces of the substances are not enough to float heavy-than-water foreign bodies. A model of ophthalmic surgery was constructed. A BB pellet was dropped from 24 mm onto a force transducer through four different fluids: balanced salt solution, perfluoro-n-octane, viscoelastic, and silicone oil. The impact energy (force) for each case was measured and recorded by the force transducer. The mean force of impact for each fluid was compared using the Student t-test. Silicone oil resulted in the lowest force of impact. Both silicone oil and viscoelastic dampened the impact an order of magnitude more than perfluoro-n-octane and balanced salt solution. Silicone oil and viscoelastic cushioned the force from a dropped BB. They may be useful adjuncts to prevent iatrogenic retinal injury during vitrectomy for intraocular foreign body removal. © 2012 The Authors. Clinical and Experimental Ophthalmology © 2012 Royal Australian and New Zealand College of Ophthalmologists.

Conformational Study of Dibenzyl Ether

NASA Astrophysics Data System (ADS)

Hernandez-Castillo, Alicia O.; Abeysekera, Chamara; Hewett, Daniel M.; Zwier, Timothy S.

2017-06-01

Understanding the initial stages of polycyclic aromatic hydrocarbon (PAH) aggregation, the onset of soot formation, is an important goal on the pathway to cleaner combustion processes. PAHs with short alkyl chains, present in fuel-rich combustion environments, can undergo reactions that will chemically link aromatic rings together. One such example of a linked diaryl compound is dibenzyl ether, C_{6}H_{5}-CH_{2}-O-CH_{2}-C_{6}H_{5}. The -CH_{2}-O-CH_{2}- linkage has a length and flexibility well-suited to forming a π-stacked conformation between the two phenyl rings. In this talk, we will explore the single-conformation spectroscopy of dibenzyl ether under jet-cooled conditions in the gas phase. Laser-induced fluorescence, chirped pulse Fourier transform microwave (8-18 GHz region), and single-conformation infrared spectroscopy in the alkyl CH stretch region were all carried out on the molecule, thereby interrogating its full array of electronic, vibrational and rotational degrees of freedom. This work is the first step in a broader study to determine the extent of π-stacking in linked aryl compounds as a function of linkage and PAH size.

Frenolicins C-G, pyranonaphthoquinones from Streptomyces sp. RM-4-15.

PubMed

Wang, Xiachang; Shaaban, Khaled A; Elshahawi, Sherif I; Ponomareva, Larissa V; Sunkara, Manjula; Zhang, Yinan; Copley, Gregory C; Hower, James C; Morris, Andrew J; Kharel, Madan K; Thorson, Jon S

2013-08-23

Appalachian active coal fire sites were selected for the isolation of bacterial strains belonging to the class actinobacteria. A comparison of high-resolution electrospray ionization mass spectrometry (HRESIMS) and ultraviolet (UV) absorption profiles from isolate extracts to natural product databases suggested Streptomyces sp. RM-4-15 to produce unique metabolites. Four new pyranonaphthoquinones, frenolicins C-F (1-4), along with three known analogues, frenolicin (6), frenolicin B (7), and UCF76-A (8), were isolated from the fermentation of this strain. An additional new analogue, frenolicin G (5), along with two known compounds, deoxyfrenolicin (9) and UCF 13 (10), were isolated from the fermentation supplied with 18 mg/L of scandium chloride, the first example, to the best of our knowledge, wherein scandium chloride supplementation led to the confirmed production of new bacterial secondary metabolites. Structures 1-5 were elucidated on the basis of spectral analysis and chemical modification. While frenolicins are best known for their anticoccidial activity, the current study revealed compounds 6-9 to exhibit moderate cytotoxicity against the human lung carcinoma cell line (A549) and thereby extends the anticancer SAR for this privileged scaffold.

Profiling LC-DAD-ESI-TOF MS method for the determination of phenolic metabolites from avocado (Persea americana).

PubMed

Hurtado-Fernández, Elena; Carrasco-Pancorbo, Alegría; Fernández-Gutiérrez, Alberto

2011-03-23

A powerful HPLC-DAD-ESI-TOF MS method was established for the efficient identification of the chemical constituents in the methanolic extracts of avocado (Persea americana). Separation and detection conditions were optimized by using a standard mix containing 39 compounds belonging to phenolic acids and different categories of flavonoids, analytes that could be potentially present in the avocado extracts. Optimum LC separation was achieved on a Zorbax Eclipse Plus C18 analytical column (4.6×150 mm, 1.8 μm particle size) by gradient elution with water+acetic acid (0.5%) and acetonitrile as mobile phases, at a flow rate of 1.6 mL/min. The detection was carried out by ultraviolet-visible absorption and ESI-TOF MS. The developed method was applied to the study of 3 different varieties of avocado, and 17 compounds were unequivocally identified with standards. Moreover, around 25 analytes were tentatively identified by taking into account the accuracy and isotopic information provided by TOF MS.

(2,2′-Biquinoline-κ2 N,N′)dichlorido­iron(II)

PubMed Central

Rahimi, Narjes; Safari, Nasser; Amani, Vahid; Khavasi, Hamid Reza

2009-01-01

In the title compound, [FeCl2(C18H12N2)], the FeII atom is four-coordinated in a distorted tetra­hedral arrangement by an N,N′-bidentate 2,2′-biquinoline ligand and two chloride ions. In the crystal, there are extensive π–π contacts between the pyridine rings [centroid–centroid distances = 3.7611 (3), 3.7603 (4), 3.5292 (4), 3.5336 (5) and 3.6656 (4) Å]. PMID:21578122

8-Hydr­oxy-5,6,7-trimeth­oxy-2-phenyl-4H-chromen-4-one

PubMed Central

Theodoro, Jahyr E.; Santos, Djalma; Pérez, Hiram; da Silva, Maria Fátima das Graças Fernandes; Ellena, J.

2008-01-01

In the title compound, C18H16O6, the benzopyran group is essentially planar, with the O atoms of the substituent groups lying close to its mean plane. The mol­ecular conformation is governed by intra­molecular inter­actions. The crystal packing is mainly determined by one classical inter­molecular hydrogen bond which gives rise to the formation of an infinite chain along the a axis. PMID:21202382

The usefulness of c-Kit in the immunohistochemical assessment of melanocytic lesions

PubMed Central

Pilloni, L.; Bianco, P.; Difelice, E.; Cabras, S.; Castellanos, M.E.; Atzori, L.; Ferreli, C.; Mulas, P.; Nemolato, S.; Faa, G.

2011-01-01

C-Kit (CD117), the receptor for the stem cell factor, a growth factor for melanocyte migration and proliferation, has shown differential immunostaining in various benign and malignant melanocytic lesions. The purpose of this study is to compare c-Kit immunostaining in benign nevi and in primary and metastatic malignant melanomas, to determine whether c-Kit can aid in the differential diagnosis of these lesions. c-Kit immunostaining was performed in 60 cases of pigmented lesions, including 39 benign nevi (5 blue nevi, 5 intra-dermal nevi, 3 junctional nevi, 15 cases of primary compound nevus, 11 cases of Spitz nevus), 18 cases of primary malignant melanoma and 3 cases of metastatic melanoma. The vast majority of nevi and melanomas examined in this study were positive for c-Kit, with minimal differences between benign and malignant lesions. C-Kit cytoplasmatic immunoreactivity in the intraepidermal proliferating nevus cells, was detected in benign pigmented lesions as well as in malignant melanoma, increasing with the age of patients (P=0.007) in both groups. The patient’s age at presentation appeared to be the variable able to cluster benign and malignant pigmented lesions. The percentage of c-Kit positive intraepidermal nevus cells was better associated with age despite other variables (P=0.014). The intensity and percentage of c-Kit positivity in the proliferating nevus cells in the dermis was significantly increased in malignant melanocytic lesions (P=0.015 and P=0.008) compared to benign lesions (compound melanocytic nevi, Spitz nevi, intradermal nevi, blue nevi). Immunostaning for c-Kit in metastatic melanomas was negative. Interestingly in two cases of melanoma occurring on a pre-existent nevus, the melanoma tumor cells showed strong cytoplasmatic and membranous positivity for c-kit, in contrast with the absence of any immunoreactivity in pre-existent intradermal nevus cells. C-Kit does not appear to be a strong immunohistochemical marker for distinguishing melanoma from melanocytic nevi, if we consider c-Kit expression in intraepidermal proliferating cells. The c-Kit expression in proliferating melanocytes in the dermis could help in the differential diagnosis between a superficial spreading melanoma (with dermis invasion) and a compound nevus or an intradermal nevus. Finally, c-Kit could be a good diagnostic tool for distinguishing benign compound nevi from malignant melanocytic lesions with dermis invasion and to differentiate metastatic melanoma from primary melanoma. PMID:22193299

Intracellular delivery and antitumor effects of pH-sensitive liposomes based on zwitterionic oligopeptide lipids.

PubMed

Mo, Ran; Sun, Qiong; Li, Nan; Zhang, Can

2013-04-01

pH-sensitive liposomes (HHG2C(18)-L and PEGHG2C(18)-L) based on zwitterionic oligopeptide lipids as anticancer drug carriers were developed and evaluated for effective intracellular delivery and enhanced antitumor activity. The amino acid-based lipids, 1,5-dioctadecyl-l-glutamyl 2-histidyl-hexahydrobenzoic acid (HHG2C(18)) and 1,5-distearyl N-(N-α-(4-mPEG2000) butanedione)-histidyl-l-glutamate (PEGHG2C(18)), were synthesized, which have the multistage pH-response to tumor microenvironmental pH (pH(e), pH 6.0-7.0) and endosomal/lysosomal pH (pH(i), pH 4.0-6.0) successively. HHG2C(18)-L contains HHG2C(18), while PEGHG2C(18)-L includes HHG2C(18) and PEGHG2C(18). Both of them displayed the capability of charge conversion to the surrounding pH. The zeta potentials of HHG2C(18)-L and PEGHG2C(18)-L were negative at pH 7.4, whereas positive at pH 6.5 and more positive at lower pH. Coumarin 6-loaded HHG2C(18)-L (C6/HHG2C(18)-L) and PEGHG2C(18)-L (C6/PEGHG2C(18)-L) showed higher tumor cellular uptake due to electrostatic absorptive endocytosis at pH(e) (pH 6.5), produced proton sponge effect for endo-lysosomal escape, and accumulated to the mitochondria based on stronger positive charge by the hydrolysis of a pH-sensitive linker at pH(i) (pH 5.5 and pH 4.5). Furthermore, temsirolimus (CCI-779)-loaded HHG2C(18)-L (CCI-779/HHG2C(18)-L) and PEGHG2C(18)-L (CCI-779/PEGHG2C(18)-L) had significantly higher antiproliferative and apoptosis inducing effects toward the human renal carcinoma (A498) cells at pH 6.5 relative to that at pH 7.4. The half maximal inhibitory concentration (IC50) of CCI-779/HHG2C(18)-L and CCI-779/PEGHG2C(18)-L were about 3 μg/mL and 5 μg/mL at pH 6.5, 1.67-fold and 1.60-fold improved relative to that at pH 7.4, respectively. The total apoptotic ratio of CCI-779/HHG2C(18)-L and CCI-779/PEGHG2C(18)-L increased from 9.90% and 7.78% at pH 7.4 to 19.53% and 12.10% at pH 6.5, respectively. In vivo, CCI-779/PEGHG2C(18)-L after intravenous administration presented remarkably higher bioavailability and blood persistence compared with unPEGylated CCI-779/HHG2C(18)-L, and had the strongest antitumor efficacy against xenograft renal cancer (Renca) tumor models. Accordingly, the results provide the feasibility of using pH-sensitive zwitterionic oligopeptide lipids to extend the applications of liposomes to efficient anticancer drug delivery in cancer therapy. Copyright © 2013 Elsevier Ltd. All rights reserved.

Effects of fatty acid oxidation products (green odor) on rumen bacterial populations and lipid metabolism in vitro.

PubMed

Lee, M R F; Huws, S A; Scollan, N D; Dewhurst, R J

2007-08-01

This study investigated the effects of green odor fatty acid oxidation products (FAOP) from cut grass on lipid metabolism and microbial ecology using in vitro incubations of rumen microorganisms. These compounds have antimicrobial roles in plant defense, and we hypothesized that they may influence rumen lipid metabolism. Further, they may partially explain the higher levels of conjugated linoleic acid cis-9, trans-11 in milk from cows grazing pasture. The first of 2 batch culture experiments screened 6 FAOP (1 hydroperoxide, 3 aldehydes, 1 ketone, and 1 alcohol) for effects on lipid profile, and in particular C(18) polyunsaturated fatty acid biohydrogenation. Experiment 2 used the most potent FAOP to determine effects of varying concentrations and identify relationships with effects on microbial ecology. Batch cultures contained anaerobic buffer, rumen liquor, and FAOP to a final concentration of 100 microM for experiment 1. Triplicates for each compound and controls (water addition) were incubated at 39 degrees C for 6 h. The hydroperoxide (1,2-dimethylethyl hydroperoxide, 1,2-DMEH) and the long chain aldehyde (trans-2 decenal) had the largest effects on lipid metabolism with significant increases in C(18:0) and C(18:1) trans and reductions in C(12:0), C(14:0), C(16:0), C(18:1) cis, C(18:2n-6), C(18:3n-3), C(20:0) and total branch and odd chain fatty acids compared with the control. This was associated with significantly higher biohydrogenation of C(18) polyunsaturated fatty acid. In experiment 2, 1,2-DMEH was incubated at 50, 100, and 200 microM for 2, 6, and 24 h. Increasing 1,2-DMEH concentration resulted in a significant linear increase in C(18:1) trans-10, trans-11, conjugated linoleic acid, and C(18:0) and a linear decrease in C(18:2n-6) and C(18:3n-3), although the scale of this response declined with time. Microbial profiling techniques showed that 1,2-DMEH at concentrations of 100 and 200 microM changed the microbial community from as early as 2 h after addition, though microbial biomass remained similar. These preliminary studies have shown that FAOP can alter fatty acid biohydrogenation in the rumen. This change was associated with changes in the microbial population that were detected through DNA and branched- and odd-chain fatty acid profiling approaches.

Placental transfer and pharmacokinetics of a single oral dose of [14C]p-nitrophenol in rats.

PubMed

Abu-Qare, A W; Brownie, C F; Abou-Donia, M B

2000-09-01

The pharmacokinetics and placental transfer of a single oral dose of 100 mg/kg (10 microCi/kg, 16% of acute oral LD50) of uniformly phenyl-labeled [14C]p-nitrophenol were investigated in pregnant Sprague-Dawley rats at 14-18 days of gestation. Three animals were killed on gestation day 18, at 0.5, 1, 2, 4, 12, 24, and 48 h after dosing. Radioactivity was rapidly absorbed and distributed throughout the maternal and fetal tissues. The gastrointestinal tract contents retained 20% and 2% of the dose at 0.5 h and 4 h after dosing. The peak maternal plasma concentration of radioactivity (microg p-nitrophenol equivalent/ml) was 7.17 compared with 0.37 for fetal plasma at 0.5 h. Maximum concentration of radioactivity (microg p-nitrophenol equivalent/g fresh tissue) was detected in most tissues 0.5 h after dosing and was in descending order: kidney 23.27, liver 12.37, placenta 3.56, fetus 2.17, and brain 1.99. Radioactivity was eliminated from plasma and all tissues beiexponentially. The half-lives of elimination of 14C were 34.65 h and 69.30 h for maternal and fetal plasma, respectively. p-Nitrophenol, detected by HPLC, was the major compound identified in plasma and tissues. While p-nitrophenol disappeared biphasically from maternal plasma and kidney, it was eliminated monophasically from brain, placenta, and liver. p-Nitrocatechol and p-aminophenol were detected in the liver with peak concentrations at 0.5 h of 1.13 and 1.00 microg/g fresh tissue, respectively. While the change in the concentration of p-nitrocatechol with time was monophasic, that of p-aminophenol showed a biphasic pattern with elimination half-lives of 1.93 h and 4.95 h, respectively. Radioactivity was rapidly excreted in the urine mostly as polar metabolites, while only 3% of the dose was recovered in the feces. Radioactive materials excreted in the urine comprised: glucuronides 4%, sulfates 8%, hot-acid hydrolysates 11%, nonconjugated compounds 16%, and water-soluble metabolites 61%. This study demonstrated that although orally administered p-nitrophenol is a rapidly absorbed and excreted compound, it is transported to the maternal brain and the fetus and may pose a health risk following exposure to toxic doses during pregnancy.

Crystal structures of (±)-(1SR,5SR,6SR,7SR,10SR,11SR,13RS,14SR)-13-hy-droxy-7-meth-oxy-meth-oxy-11,15,18,18-tetra-methyl-3-oxo-2,4-dioxa-tetra-cyclo-[12.3.1.0(1,5).0(6,11)]octa-dec-15-en-10-yl benzoate, its 13-epimer and 13-one derivative.

PubMed

Oishi, Takeshi; Fukaya, Keisuke; Yamaguchi, Yu; Sugai, Tomoya; Watanabe, Ami; Sato, Takaaki; Chida, Noritaka

2015-05-01

The title compounds, C29H38O8·0.25C5H12, (A), C29H38O8, (B), and C29H36O8, (C), are tetra-cyclic benzoates possessing a taxane skeleton with a fused dioxolane ring as the core structure. In the asymmetric unit of (A), there are two independent benzoate mol-ecules (A and A') and a half mol-ecule of solvent pentane disordered about an inversion center. The mol-ecular conformations of (A), (B) and (C) are similar except for the flexible meth-oxy-meth-oxy group. The cyclo-hexane, cyclo-hexene and central cyclo-octane rings adopt chair, half-chair and chair-chair (extended crown) forms, respectively. The dioxolane rings are essentially planar, while the dioxolane ring of A' is slightly twisted from the mean plane. In the crystal of (A), inter-molecular O-H⋯O, C-H⋯O and C-H⋯π inter-actions link the independent benzoates alternately, forming a chain structure. In the crystals of (B) and (C), mol-ecules are linked through O-H⋯O and C-H⋯π inter-actions, and C-H⋯O hydrogen bonds, respectively, into similar chains. Further, weak inter-molecular C-H⋯O inter-actions connect the chains into a three-dimensional network in (A) and a sheet in (B), whereas no other interactions are observed for (C).

Calibrations and Comparisons of Aerosol Spectrometers linking Ground and Airborne Measurements

NASA Astrophysics Data System (ADS)

Williamson, C.; Brock, C. A.; Erdesz, F.

2015-12-01

The nucleation-mode aerosol size spectrometer (NMASS), a fast-time response instrument measuring aerosol size distributions between 5 and 60nm, is to sample in the boundary layer and free troposphere on NASA's Atmospheric Tomography mission (ATom), providing contiguous data with global coverage in all four seasons. In preparation for this the NMASS is calibrated for the expected flight conditions and compatibility studies are made with ground-based instrumentation. The NMASS is comprised of 5 parallel condensation particle counters (CPCs) using perfluoro-tributylamine as a working fluid. Understanding the variation of CPC counting efficiencies with respect to the chemical composition of the sample is important for accurate data analysis and can be used to give indirect information about sample chemical composition. This variation is strongly dependent on the working fluid. The absolute responses and associated variations of the NMASS to ammonium sulfate and limonene ozonolysis products, compounds pertinent to the composition of particles nucleated in the free troposphere and boundary later, are compared to those of butanol, diethylene-glycol and water based CPCs, which are more commonly used in ground-based measurements. While fast time-response is key to measuring aerosol size distributions on flights, high size-resolution is often prioritized for ground-based measurements, and so a scanning mobility particle sizer (SMPS) is commonly used. Inter-comparison between NMASS and SMPS data is non-trivial because of the different working principles and resolutions of the instruments and yet it is vital, for example, for understanding the sources of particles observed during flights and the global relevance of phenomena observed from field stations and in chambers. We report compatibility studies on inversions of data from the SMPS and NMASS, evaluating temporal and spatial resolution and sources of uncertainty.

Isolation and characterization of a hydrocarbonoclastic bacterial enrichment from total petroleum hydrocarbon contaminated sediments: potential candidates for bioaugmentation in bio-based processes.

PubMed

Di Gregorio, Simona; Siracusa, Giovanna; Becarelli, Simone; Mariotti, Lorenzo; Gentini, Alessandro; Lorenzi, Roberto

2016-06-01

Seven hydrocarbonoclastic new bacterial isolates were isolated from dredged sediments of a river estuary in Italy. The sediments were contaminated by shipyard activities since decades, mainly ascribable to the exploitation of diesel oil as the fuel for recreational and commercial navigation of watercrafts. The bacterial isolates were able to utilize diesel oil as sole carbon source. Their metabolic capacities were evaluated by GC-MS analysis, with reference to the depletion of both the normal and branched alkanes, the nC18 fatty acid methyl ester and the unresolved complex mixture of organic compounds. They were taxonomically identified as different species of Stenotrophomonas and Pseudomonas spp. by the combination of amplified ribosomal DNA restriction analysis (ARDRA) and repetitive sequence-based PCR (REP-PCR) analysis. The metabolic activities of interest were analyzed both in relation to the single bacterial strains and to the combination of the latter as a multibacterial species system. After 6 days of incubation in mineral medium with diesel oil as sole carbon source, the Stenotrophomonas sp. M1 strain depleted 43-46 % of Cn-alkane from C28 up to C30, 70 % of the nC18 fatty acid methyl ester and the 46 % of the unresolved complex mixture of organic compounds. On the other hand, the Pseudomonas sp. NM1 strain depleted the 76 % of the nC18 fatty acid methyl ester, the 50 % of the unresolved complex mixture of organic compounds. The bacterial multispecies system was able to completely deplete Cn-alkane from C28 up to C30 and to deplete the 95 % of the unresolved complex mixture of organic compounds. The isolates, either as single strains and as a bacterial multispecies system, were proposed as candidates for bioaugmentation in bio-based processes for the decontamination of dredged sediments.

Dependence of the basic properties of meso-nitro-substituted derivatives of β-octaethylporphyrin on the nature of substituents

NASA Astrophysics Data System (ADS)

Pukhovskaya, S. G.; Ivanova, Yu. B.; Nam, Dao The; Vashurin, A. S.

2014-10-01

Spectrophotometric titration is used to study the basic properties of a series of porphyrins with a continuously increasing degree of macrocycle deformation resulting from the introduction of strong electron-withdrawing substituents: 2,3,7,8,12,13,17,18-octaethylporphyrin ( I), 5-nitro-2,3,7,8,12,13,17,18-octaethylporphyrin ( II), 5,15-dinitro-2,3,7,8,12,13,17,18-octaethylporphyrin ( III), 5,10,15-trinitro-2,3,7,8,12,13,17,18-octaethylporphyrin ( IV), and 5,10,15,20-tetranitro-2,3,7,8,12,13,17,18-octaethylporphyrin ( V). It is found that the values of log K b (total basicity constants) obtained for the investigated compounds consistently diminish with an increase in the number of meso-substituents: 11.85 ( I) > 10.45 ( II) > 10.31 ( III) > 10.23 ( IV) > 9.56 ( V). It is shown that two opposing factors, the steric and electronic effects of the substituents, change the basic properties of the above series of compounds.

Green, unexpected synthesis of bis-coumarin derivatives as potent anti-bacterial and anti-inflammatory agents.

PubMed

Chougala, Bahubali M; Samundeeswari, S; Holiyachi, Megharaja; Naik, Nirmala S; Shastri, Lokesh A; Dodamani, Suneel; Jalalpure, Sunil; Dixit, Sheshagiri R; Joshi, Shrinivas D; Sunagar, Vinay A

2018-01-01

A green and efficient protocol has been developed and a series of coumarin based pyrano[3,2-c]chromene derivatives (2) have been synthesized using multi-component reaction (MCR) approach. Unexpected 3-coumarinyl-3-pyrazolylpropanoic acids (3) and C 4 -C 4 chromenes (5) have been isolated instead of expected product 4 by the reaction of compound (2) in formic acid at 90 °C for about 4-5 h and at 130 °C for about 8-10 h respectively. Further, C 4 -C 4 chromenes (5) formation was confirmed by intramolecular cyclization of compounds (3). These compounds were screened for their biological activities and most of them exhibited promising antibacterial activity. The anti-inflammatory assay was evaluated against HRBC membrane stabilization method and the compounds exhibit excellent anti-inflammatory activity. Molecular docking study has been performed for all the synthesized compounds with Klebsiella pneumoni aeacetolactate synthase and results obtained are quite promising. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Determination of the major phenolic compounds in pomegranate juices by HPLC−DAD−ESI-MS.

PubMed

Gómez-Caravaca, Ana María; Verardo, Vito; Toselli, Moreno; Segura-Carretero, Antonio; Fernández-Gutiérrez, Alberto; Caboni, Maria Fiorenza

2013-06-05

Traditionally, pomegranate (Punica granatum L.) has been consumed as fresh fruit or as pomegranate juice. In this study, the main phenolic compounds of 12 pomegranate varieties and 5 pomegranate clones were determined by HPLC−DAD−ESI-MS. Two chromatographic methods with a fused-core C18 column and a classical HPLC system were developed. Thirteen anthocyanins and fourteen other phenolic compounds were determined in the pomegranate juices. As far as we are concerned, a new flavonol-glycoside, phellatin or its isomer amurensin, has been tentatively identified for the first time in pomegranate juices. Total phenolic content ranged from 580.8 to 2551.3 mg/L of pomegranate juice. Anthocyanins varied between 20 to 82% of total phenolic content. Flavonoids were 1.6-23.6% of total phenolic compounds, while phenolic acids and ellagitannins were in the range 16.4-65.8%. The five clones reported a phenolic content comparable with that of the other pomegranate samples.

40 CFR 52.1070 - Identification of plan.

Code of Federal Regulations, 2011 CFR

2011-07-01

... Requirements 6/18/90 4/14/94, 59 FR 17698 (c)(100). 26.11.05.03 Air Pollution Episode Criteria 6/18/90 4/14/94... plastic parts coating 4/19/10 9/27/10, 75 FR 59084 Revisions to Section .07A, .07B and the addition of new... 3852 (c)(141). 26.11.19.26 Control of Volatile Organic Compound Emissions from Reinforced Plastic...

Imaging of amyloid deposition in human brain using positron emission tomography and [18F]FACT: comparison with [11C]PIB.

PubMed

Ito, Hiroshi; Shinotoh, Hitoshi; Shimada, Hitoshi; Miyoshi, Michie; Yanai, Kazuhiko; Okamura, Nobuyuki; Takano, Harumasa; Takahashi, Hidehiko; Arakawa, Ryosuke; Kodaka, Fumitoshi; Ono, Maiko; Eguchi, Yoko; Higuchi, Makoto; Fukumura, Toshimitsu; Suhara, Tetsuya

2014-04-01

The characteristic neuropathological changes in Alzheimer's disease (AD) are deposition of amyloid senile plaques and neurofibrillary tangles. The (18)F-labeled amyloid tracer, [(18)F]2-[(2-{(E)-2-[2-(dimethylamino)-1,3-thiazol-5-yl]vinyl}-1,3-benzoxazol-6-yl)oxy]-3-fluoropropan-1-ol (FACT), one of the benzoxazole derivatives, was recently developed. In the present study, deposition of amyloid senile plaques was measured by positron emission tomography (PET) with both [(11)C]Pittsburgh compound B (PIB) and [(18)F]FACT in the same subjects, and the regional uptakes of both radiotracers were directly compared. Two PET scans, one of each with [(11)C]PIB and [(18)F]FACT, were performed sequentially on six normal control subjects, two mild cognitive impairment (MCI) patients, and six AD patients. The standardized uptake value ratio of brain regions to the cerebellum was calculated with partial volume correction using magnetic resonance (MR) images to remove the effects of white matter accumulation. No significant differences in the cerebral cortical uptake were observed between normal control subjects and AD patients in [(18)F]FACT studies without partial volume correction, while significant differences were observed in [(11)C]PIB. After partial volume correction, the cerebral cortical uptake was significantly larger in AD patients than in normal control subjects for [(18)F]FACT studies as well as [(11)C]PIB. Relatively lower uptakes of [(11)C]PIB in distribution were observed in the medial side of the temporal cortex and in the occipital cortex as compared with [(18)F]FACT. Relatively higher uptake of [(11)C]PIB in distribution was observed in the frontal and parietal cortices. Since [(18)F]FACT might bind more preferentially to dense-cored amyloid deposition, regional differences in cerebral cortical uptake between [(11)C]PIB and [(18)F]FACT might be due to differences in regional distribution between diffuse and dense-cored amyloid plaque shown in the autoradiographic and histochemical assays of postmortem AD brain sections.

Development and validation of a stability-indicating RP-HPLC-FLD method for determination of 5-[(4-chlorophenoxy) methyl]-1, 3, 4-oxadiazole-2-thiol; A novel drug candidate.

PubMed

Shehzadi, Naureen; Hussain, Khalid; Islam, Muhammad; Bukhari, Nadeem Irfan; Asif, Noman; Khan, Muhammad Tanveer; Salman, Muhammad; Qamar, Shaista; Parveen, Sajida; Zahid, Fakhra; Shah, Arshad Ali; Bilal, Abida; Abbasi, Muhammad Athar; Siddiqui, Sabahat Zahra; Rehman, Azizur

2018-03-01

The present study describes the development and validation of a simple high performance liquid chromatographic method for the determination of a novel drug candidate, 5-[(4-chlorophenoxy) methyl]-1, 3, 4-oxadiazole-2-thiol. The stability-indicating capacity of the method was evaluated by subjecting the compound's solution to hydrolytic, oxidative, photolytic, transition metal- and thermal- stress. The chromatographic separation was achieved over a C18 column (Promosil, 5 µm, 4.60 × 250 mm), maintained at 25°C, using an isocratic mobile phase comprising a mixture of acetonitrile and acidified water of pH 2.67 (1:1, v/v), at a flow rate of 1.00 mL/min and detection using a fluorescent light detector (excitation at 250 nm and emission at 410 nm). The Beer's law was followed over the concentration range 2.50-50.00 μg/ml. The recovery (98.56-100.19%, SD <5%), intraday accuracy and precision (97.31-100.81%, RSD <5%), inter-day accuracy and precision (97.50-100.75%, RSD <5%) and intermediate accuracy and precision (98.10-99.91%, RSD <5%) indicated that the method was reliable, repeatable, reproducible and rugged. The resolution and selectivity factors of the compound's peak from the nearest resolving peak, particularly in case of dry heat and copper metal stress, were found to be greater than 2 and 1, respectively, which indicated specificity and selectivity. The compound was extensively decomposed in alkaline-hydrolytic, oxidative, metal- and dry heat- stress. However, the compound in acidic and neutral conditions was resistant to photolysis. The results of the present study indicate that the developed method is specific, selective, sensitive and suitable, hence, may be used for quality control, stability testing and preformulation studies.

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 of a Potent Aminopyridine-Based nNOS-Inhibitor by Two Recent No-Carrier-Added (18)F-Labelling Methods.

PubMed

Drerup, Christian; Ermert, Johannes; Coenen, Heinz H

2016-09-01

Nitric oxide (NO), an important multifunctional signaling molecule, is produced by three isoforms of NO-synthase (NOS) and has been associated with neurodegenerative disorders. Selective inhibitors of the subtypes iNOS (inducible) or nNOS (neuronal) are of great interest for decoding neurodestructive key factors, and (18)F-labelled analogues would allow investigating the NOS-function by molecular imaging with positron emission tomography. Especially, the highly selective nNOS inhibitor 6-((3-((3-fluorophenethylamino)methyl)phenoxy)methyl)-4-methylpyridin-2-amine (10) lends itself as suitable compound to be (18)F-labelled in no-carrier-added (n.c.a.) form. For preparation of the (18)F-labelled nNOS-Inhibitor [(18)F]10 a "build-up" radiosynthesis was developed based on a corresponding iodonium ylide as labelling precursor. The such activated phenethyl group of the compound was efficiently and regioselectively labelled with n.c.a. [(18)F]fluoride in 79% radiochemical yield (RCY). After conversion by reductive amination and microwave assisted displacement of the protecting groups, the desired nNOS-inhibitor was obtained in about 15% total RCY. Alternatively, for a simplified "late-stage" (18)F-labelling procedure a corresponding boronic ester precursor was synthesized and successfully used in a newer, copper(II) mediated n.c.a. (18)F-fluoro-deboroniation reaction, achieving the same total RCY. Thus, both methods proved comparatively suited to provide the highly selective NOS-inhibitor [(18)F]10 as probe for preclinical in vivo studies.

Turn on macrocyclic chemosensor for Al3+ ion with facile synthesis and application in live cell imaging.

PubMed

Ezhumalai, Dhineshkumar; Mathivanan, Iyappan; Chinnadurai, Anbuselvan

2018-06-15

An effort of a new Schiff base macrocyclic chemosensor, 1 4 ‑methyl‑2,6,8,12,14,18‑hexaaza‑1,7,13(1,2),4,10,16(1,4)‑hexabenzenacyclooctadecaphane‑2,5,8,11,14,17‑hexaene (me1) and 1 4 ,7 4 ‑dimethyl‑2,6,8,12,14,18‑hexaaza‑1,7,13(1,2),4,10,16(1,4)‑hexabenzenacyclooctadecadecaphane‑2,5,8,11,14,17‑hexaene (dm2), which enables selective sensing of Al 3+ in aqueous DMF were synthesized by a simplistic one-step condensation reaction of macrocyclic compounds. The probe me1 and dm2 characterized by elemental analysis, FT-IR, 1 H and 13 C NMR, LC-MS spectral techniques. The compounds as mentioned above subjected to FE-SEM with EDS and elemental color mapping. On addition of Al 3+ , the fluorescent probe me1 and dm2 induces turn-on responses in both absorption and sensing spectra by a PET mechanism. The receptor me1 and dm2 serve highly selective, sensitive and turn-on detection of Al 3+ . Further, they did not interfere with other cations present in biological or environmental samples. The detection limit is found to be 3μM and 5μM. From the view of cytotoxic activity, the ability of these compounds me1 and dm2 to inhibit the growth of KB cell lines examined. The chelating functionality of compounds me1 and dm2 examined for their inhibitory properties of KB cell, live cell images. The compounds me1 and dm2 subjected to theoretical studies by DFT-B3LYP invoking the 6-31G level of theory. The energy of the HOMO and LUMO has been established. Copyright © 2018 Elsevier B.V. All rights reserved.

[Determination of three exogenous plant hormone residues in bean sprout by high performance liquid chromatography-quadrupole-time of flight mass spectrometry].

PubMed

Xie, Hanbing; Zhou, Mingying; Zhao, Haifeng; Wang, Yigang; Jiang, Wanfeng; Zhao, Shan

2014-05-01

This study was aimed to the establishment of an analytical method for the determination of three exogenous plant hormone residues in bean sprout by high performance liquid chromatography-quadrupole-time of flight mass spectrometry (HPLC-Q-TOF-MS). The target compounds were gibberellins, 6-benzylaminopurine and parachlorophenoxyacetic acid. The QuEChERS (quick, easy, cheap, effective, rugged, and safe) method was used for sample preparation. The analytes were extracted with a solution containing 1% (v/v, if not specified) acetic, 50% ethanol, 49% acetonitrile, and cleaned-up by dispersive solid-phase extraction with diatomite dispersant, then degreased by hexane. The three target compounds were separated on an Eclipse Plus C18 column (100 mm x 3.0 mm, 1.8 microm) with mobile phases A (water containing 0.1% formic acid) and B (methanol) by gradient elution within 15 min, and detected under negative electrospray ionization (ESI) mode. The quantitative analysis was carried out by extracting the peak area with accurate mass. The confirmatory analysis of the target compounds was performed with the qualitative fragments. The results showed that the limits of quantification (LOQs, S/N = 10) for the three target compounds were from 5.0 microg/kg to 10 microg/kg. The respective mean recoveries were found to be in the range of 79.1%-96.1%, and the RSDs were 5.7%-10.4%. It was applicable to the analysis of the three exogenous plant hormones in bean sprout samples. This method is simple, fast and efficient.

X-ray investigations of sulfur-containing fungicides. IV. 4'-[[Benzoyl(4-chlorophenylhydrazono)methyl]sulfonyl]acetanilide and 4'-[[benzoyl(4-methoxyphenylhydrazono)methyl]sulfonyl]acetanilide.

PubMed

Wolf, W M

2001-09-01

The conformations of the two approximately isomorphous structures 4'-[[benzoyl(4-chlorophenylhydrazono)methyl]sulfonyl]acetanilide, C(22)H(18)ClN(3)O(4)S, and 4'-[[benzoyl(4-methoxyphenylhydrazono)methyl]sulfonyl]acetanilide, C(23)H(21)N(3)O(5)S, are stabilized by resonance-assisted intramolecular hydrogen bonds linking the hydrazone moieties and sulfonyl groups. The stronger bond is observed in the former compound. The difference in electronic properties between the Cl atom and the methoxy group is too small to significantly alter the non-bonding interactions of the sulfonyl and beta-carbonyl groups.

Comparison of the crystal structures of methyl 4-bromo-2-(meth-oxy-meth-oxy)benzoate and 4-bromo-3-(meth-oxy-meth-oxy)benzoic acid.

PubMed

Suchetan, P A; Suneetha, V; Naveen, S; Lokanath, N K; Krishna Murthy, P

2016-04-01

The title compounds, C10H11BrO4, (I), and C9H9BrO4, (II), are derivatives of bromo-hy-droxy-benzoic acids. Compound (II) crystallizes with two independent mol-ecules (A and B) in the asymmetric unit. In both (I) and (II), the O-CH2-O-CH3 side chain is not in its fully extended conformation; the O-C-O-C torsion angle is 67.3 (3) ° in (I), and -65.8 (3) and -74.1 (3)° in mol-ecules A and B, respectively, in compound (II). In the crystal of (I), mol-ecules are linked by C-H⋯O hydrogen bonds, forming C(5) chains along [010]. The chains are linked by short Br⋯O contacts [3.047 (2) Å], forming sheets parallel to the bc plane. The sheets are linked via C-H⋯π inter-actions, forming a three-dimensional architecture. In the crystal of (II), mol-ecules A and B are linked to form R 2 (2)(8) dimers via two strong O-H⋯O hydrogen bonds. These dimers are linked into ⋯A-B⋯A-B⋯A-B⋯ [C 2 (2)(15)] chains along [011] by C-H⋯O hydrogen bonds. The chains are linked by slipped parallel π-π inter-actions [inter-centroid distances = 3.6787 (18) and 3.8431 (17) Å], leading to the formation of slabs parallel to the bc plane.

Phytochemical Analysis on Quantification and the Inhibitory Effects on Inflammatory Responses from the Fruit of Xanthii fructus

PubMed Central

Yoo, Sae-Rom; Seo, Chang-Seob; Lee, Na-Ri; Shin, Hyeun-Kyoo; Jeong, Soo-Jin

2015-01-01

Objective: Xanthii fructus (Compositae) is a traditional herbal medicine used for treating headache, toothache, pruritus, empyema, and rhinitis. In this study of the quality control of X. fructus, we performed simultaneous analysis of nine marker compounds: Protocatechuic acid (1), chlorogenic acid (2), caffeic acid (3), 4,5-dicaffeoylquinic acid (4), ferulic acid (5), 3,5-dicaffeoylquinic acid (6), 1,3-dicaffeoylquinic acid (7), 1,4-dicaffeoylquinic acid (8), and 4,5-dicaffeoylquinic acid (9). Materials and Methods: Nine components were separated using reversed-phase SunFire™ C18 analytical column and analyzed using high-performance liquid chromatography. We examined the biological effects of the nine marker compounds by determining their anti-inflammatory activities in the murine macrophage cell line RAW 264.7. Results: Among the nine marker compounds, eight significantly inhibited lipopolysaccharide (LPS)-stimulated tumor necrosis factor-alpha (TNF-α) production. 1, 3, 5 had significant inhibitory effects on LPS-induced prostaglandin E2 (PGE2) production in RAW 264.7 cells. None of the tested marker compounds had a significant effect on interleukin-6 production in LPS-treated RAW 264.7 cells. Our data demonstrated that each marker compound from X. fructus exerts anti-inflammatory activity by targeting different inflammation-related pathways such as the TNF-α or PGE2 pathway. Conclusion: Further experiments using in vitro and in vivo models are needed to identify the mechanisms responsible for the anti-inflammatory properties of each marker compound. SUMMARY Simultaneous analysis of nine phenylpropanoids in the Xanthii fructus was established using HPLC-PDA system.1,4-dicaffeoylquinic acid significantly inhibited LPS-stimulated TNF-a production.Protocatechuic acid, caffeic acid and ferulic acid had significant inhibitory effects on LPS-induced PGE2 production in RAW 264.7 cells. PMID:27013799

4,5,7,8,17-Penta­hydr­oxy-14,18-dimethyl-6-methyl­ene-3,10-dioxapenta­cyclo­[9.8.0.01,7.04,19.013,18]nona­dec-14-ene-9,16-dione methanol solvate dihydrate

PubMed Central

Teh, Chin Hoe; Teoh, Siew Chin; Yeap, Chin Sing; Chan, Kit Lam; Fun, Hoong-Kun

2009-01-01

The title quassinoid compound, C20H24O9·CH3OH·2H2O, is a natural eurycomanone isolated from the roots of Eurycoma longifolia. The mol­ecules contain a fused five-ring system, with one tetra­hydro­furan ring adopting an envelope conformation, one tetra­hydro­pyran-2-one ring in a screw boat conformation, one cyclo­hexenone ring in a half-chair conformation and two cyclo­hexane rings in chair conformations. Intra­molecular C—H⋯O inter­actions generate S(5) ring motifs and an O—H⋯O inter­action generates an S(7) ring motif. In the crystal, mol­ecules are linked via inter­molecular O—H⋯O inter­actions along the b axis and further stacked along a axis. The absolute configuration of the title compound was inferred from previously solved structures of its analogues. PMID:21582604

Ideas and perspectives: hydrothermally driven redistribution and sequestration of early Archaean biomass - the "hydrothermal pump hypothesis"

NASA Astrophysics Data System (ADS)

Duda, Jan-Peter; Thiel, Volker; Bauersachs, Thorsten; Mißbach, Helge; Reinhardt, Manuel; Schäfer, Nadine; Van Kranendonk, Martin J.; Reitner, Joachim

2018-03-01

Archaean hydrothermal chert veins commonly contain abundant organic carbon of uncertain origin (abiotic vs. biotic). In this study, we analysed kerogen contained in a hydrothermal chert vein from the ca. 3.5 Ga Dresser Formation (Pilbara Craton, Western Australia). Catalytic hydropyrolysis (HyPy) of this kerogen yielded n-alkanes up to n-C22, with a sharp decrease in abundance beyond n-C18. This distribution ( ≤ n-C18) is very similar to that observed in HyPy products of recent bacterial biomass, which was used as reference material, whereas it differs markedly from the unimodal distribution of abiotic compounds experimentally formed via Fischer-Tropsch-type synthesis. We therefore propose that the organic matter in the Archaean chert veins has a primarily microbial origin. The microbially derived organic matter accumulated in anoxic aquatic (surface and/or subsurface) environments and was then assimilated, redistributed and sequestered by the hydrothermal fluids (hydrothermal pump hypothesis).

Structure and thermodynamic stability of UTa 3 O 10 , a U( v )-bearing compound

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

Guo, Xiaofeng; Lipp, Christian; Tiferet, Eitan

Heating a mixture of uranyl(VI) nitrate and tantalum(V) oxide in the molar ratio of 2 : 3 to 1400 °C resulted in the formation of a new compound, UTa 3O 10. The honey colored to yellow brown crystals of UTa 3O 10 crystallize in an orthorhombic structure with the space group Fddd (no. 70), lattice parameters a = 7.3947(1), b = 12.7599(2), c = 15.8156(2) Å, and Z = 8. Vertex sharing [TaO 6] 7- octahedra of two crystallographically distinct Ta cations form a three dimensional tantalate framework. Within this framework, six membered rings of [TaO 6] 7- octahedra aremore » formed within the (001) plane. The center of these rings is occupied by the uranyl cations [UO 2] +, with an oxidation state of +5 for uranium. The pentavalence of U and Ta was confirmed by X-ray photoelectron spectroscopy and X-ray adsorption spectroscopy. The enthalpy of formation of UTa 3O 10 from Ta 2O 5, β-U 3O 7, and U 3O 8 has been determined to be 13.1 ± 18.1 kJ mol -1 using high temperature oxide melt solution calorimetry with sodium molybdate as the solvent at 700 °C. The close to zero enthalpy of formation of UTa 3O 10 can be explained by closely balanced structural stabilizing and destabilizing factors, which may also apply to other UM 3O 10 compounds.« less

Design, synthesis and anticancer activity of piperazine hydroxamates and their histone deacetylase (HDAC) inhibitory activity.

PubMed

Chetan, Bhadaliya; Bunha, Mahesh; Jagrat, Monika; Sinha, Barij Nayan; Saiko, Philipp; Graser, Geraldine; Szekeres, Thomas; Raman, Ganapathy; Rajendran, Praveen; Moorthy, Dhatchana; Basu, Arijit; Jayaprakash, Venkatesan

2010-07-01

Six compounds were synthesized with piperazine in linker region and hydroxamate as Zinc Binding Group (ZBG). They were screened against three cancer cell-lines (NCIH460; HCT116; U251). Compounds 5c and 5f with GI(50) value of 9.33+/-1.3 microM and 12.03+/-4 microM, respectively, were tested for their inhibitory potential on hHDAC8. Compound 5c had IC(50) of 33.67 microM. Compounds were also screened for their anticancer activity against HL60 human promyelocytic leukemia cell line due to the presence of pharmacophoric features of RR inhibitors in them. Compound 5c had IC(50) of 0.6 microM at 48h. 2010 Elsevier Ltd. All rights reserved.

Synthesis, biological evaluation, and metabolic stability of phenazine derivatives as antibacterial agents.

PubMed

Krishnaiah, Maddeboina; de Almeida, Nathalia Rodrigues; Udumula, Venkatareddy; Song, Zhongcheng; Chhonker, Yashpal Singh; Abdelmoaty, Mai M; do Nascimento, Valter Aragao; Murry, Daryl J; Conda-Sheridan, Martin

2018-01-01

Drug-resistant pathogens are a major cause of hospital- and community-associated bacterial infections in the United States and around the world. These infections are increasingly difficult to treat due to the development of antibiotic resistance and the formation of bacterial biofilms. In the paper, a series of phenazines were synthesized and evaluated for their in vitro antimicrobial activity against Gram positive (methicillin resistant staphylococcus aureus, MRSA) and Gram negative (Escherichia coli, E. coli) bacteria. The compound 6,9-dichloro-N-(methylsulfonyl)phenazine-1-carboxamide (18c) proved to be the most active molecule (MIC = 16 μg/mL) against MRSA whereas 9-methyl-N-(methylsulfonyl)phenazine-1-carboxamide (30e) showed good activity against both MRSA (MIC = 32 μg/mL) and E. coli (MIC = 32 μg/mL). Molecule 18c also demonstrated significant biofilm dispersion and inhibition against S. aureus. Preliminary studies indicate the molecules do not disturb bacterial membranes and there activity is not directly linked to the generation of reactive oxygen species. Compound 18c displayed minor toxicity against mammalian cells. Metabolic stability studies of the most promising compounds indicate stability towards phase I and phase II metabolizing enzymes. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Magnetic phase transitions and ferromagnetic short-range correlations in single-crystal Tb5Si2.2Ge1.8

NASA Astrophysics Data System (ADS)

Zou, M.; Pecharsky, V. K.; Gschneidner, K. A., Jr.; Schlagel, D. L.; Lograsso, T. A.

2008-07-01

Magnetic phase transitions in a Tb5Si2.2Ge1.8 single crystal have been studied as a function of temperature and magnetic field. Magnetic-field dependencies of the critical temperatures are highly anisotropic for both the main magnetic ordering process occurring around 120 K and a spin reorientation transition at ˜70K . Magnetic-field-induced phase transitions occur with the magnetic field applied isothermally along the a and b axes (but not along the c axis) between 1.8 and 70 K in fields below 70 kOe. Strong anisotropic thermal irreversibility is observed in the Griffiths phase regime between 120 and 200 K with applied fields ranging from 10 to 1000 Oe. Our data (1) show that the magnetic and structural phase transitions around 120 K are narrowly decoupled; (2) uncover the anisotropy of ferromagnetic short-range order in the Griffiths phase; and (3) reveal some unusual magnetic domain effects in the long-range ordered state of the Tb5Si2.2Ge1.8 compound. The temperature-magnetic field phase diagrams with field applied along the three major crystallographic directions have been constructed.

Large anisotropic thermoelectricity in perovskite related layered structure: SrnNbnO3n+2 (n=4,5)

NASA Astrophysics Data System (ADS)

Sakai, Akihiro; Kanno, Tsutomu; Takahashi, Kouhei; Yamada, Yuka; Adachi, Hideaki

2010-11-01

We measured the thermal and charge transport properties of perovskite-related layered structures. Strontium-Niobates, which were expressed as SrnNbnO3n+2 (n =4: Sr1.8La0.2Nb2O7, n =5: Sr5Nb5O17), to explore their thermoelectricities and thermal anisotropies. The behaviors of the thermoelectric parameters (thermal conductivity, Seebeck coefficient, resistivity) were strongly anisotropic in all crystallographic axes (a, b, and c) and large anisotropy exists even in the in-plane direction of the layered structure. Especially, along the a-axis in which corner-sharing NbO6 octahedra aligned straightly, contrastive properties were observed between Sr1.8La0.2Nb2O7 and Sr5Nb5O17. For Sr1.8La0.2Nb2O7, a thermally activated charge conduction is pronounced in the temperature dependence of Seebeck coefficient and resistivity, on the other hand, it was a metallic nature for Sr5Nb5O17. In both compounds, ZT results in anisotropic due to the anisotropic properties of thermoelectric parameters, the best performance is commonly observed in the a-axis. The respective ZT values at room temperature are 3.5×10-2 and 3.6×10-3.