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1

Thermodynamics of Piperazine/Methyldiethanolamine/Water/Carbon Sanjay Bishnoi and Gary T. Rochelle*  

E-print Network

Thermodynamics of Piperazine/Methyldiethanolamine/Water/Carbon Dioxide Sanjay Bishnoi and Gary T though MDEA is present at much higher concentrations. Introduction Thermodynamics of aqueous amine are usually rate-controlling. Fur- thermore, a consistent thermodynamic model can quan- tify the energy

Rochelle, Gary T.

2

Effect of chlorides on solution corrosivity of methyldiethanolamine (MDEA) solutions  

SciTech Connect

Solution corrosivity of MDEA/water solutions containing added HCl or NaCl have been measured by weight loss coupons at 250 F and by linear polarization resistance (LPR) at 208 F using carbon steel, 304SS, 316SS and 410SS. General corrosion as well as pitting or crevice corrosion tendencies were recorded for each species. Based on these results, recommendations are made for chlorides in MDEA that minimizes corrosion in gas treating operations.

Rooney, P.C.; Bacon, T.R.; DuPart, M.S.; Willbanks, K.D. [Dow Chemical Co., Freeport, TX (United States)

1997-08-01

3

Equilibrium solubilities of CO/sub 2/ and H/sub 2/S in diethanolamine (DEA) and methyldiethanolamine (MDEA) solutions  

SciTech Connect

The ability to predict equilibrium phase behavior in systems containing CO/sub 2/ and/or H/sub 2/S in alkanolamine solutions such as diethanolamine (DEA) and methyldiethanolamine (MDEA) is of vital importance for proper design and operation of acid gases treating systems. Literature data for the solubilities of CO/sub 2/ and/or H/sub 2/S in DEA and MDEA systems have been compiled and evaluated. Experimental measurements have also been made to confirm literature data and to expand the data base. A vapor-liquid equilibrium (VLE) model similar to the one developed by Kent and Eisenberg has been developed to correlate the data. The model gives the most accurate predictions when compared to other VLE models available for predicting equilibrium acid gas partial pressures over DEA and MDEA solutions.

Ho, A.S.; Equren, P.R. (Amoco Production Co., Tulsa, OK (US))

1988-01-01

4

Simultaneous absorption of H/sub 2/S and CO/sub 2/ in aqueous MDEA. [Methyldiethanolamine  

SciTech Connect

In the simultaneous absorption of two gases in a reactive liquid, the rates of absorption of both gases are affected by their competition for the same reactive reagent. The case of absorption of two gases into a reactive liquid where one reacts under second order reaction kinetics while the other reacts instantaneously is of practical interest, since this case represents the absorption of CO/sub 2/ and H/sub 2/S into amine solutions. The rates of absorption were modeled according to the penetration theory. The model equations consisting of a system of nonlinear differential equations with a moving boundary were solved numerically. The theoretical model was applied to a description of the selective absorption of H/sub 2/S in diethanolamine solution in the presence of CO/sub 2/. The simultaneous absorption of H/sub 2/S and CO/sub 2/ gases into MDEA was studied experimentally using a stirred gas liquid absorber. This case was modeled theoretically assuming one of the gases CO/sub 2/ undergoes a second order reaction condition with the solution while the other gas, H/sub 2/S is entirely gas film controlled. The kinetics of the reaction between both gases and MDEA was studied. Unavailable physical properties such as diffusivities and solubilities of different species were measured experimentally using laminar jet apparatus.

Khalil, N.M.

1984-01-01

5

Heat capacity of aqueous monoethanolamine, diethanolamine, N-methyldiethanolamine, and N-methyldiethanolamine-based blends with carbon dioxide  

SciTech Connect

New data are reported on the heat capacity of CO{sub 2}-loaded, aqueous solutions of monoethanolamine (MEA), diethanolamine (DEA), N-methyldiethanolamine (MDEA), and aqueous MDEA-based blends with MEA and DEA. The work reported here was motivated by the need to quantify the effect of acid gas loading on the important physical properties of gas-sweetening solvents.

Weiland, R.H.; Dingman, J.C.; Cronin, D.B. [Optimized Gas Treating, Inc., Houston, TX (United States)] [Optimized Gas Treating, Inc., Houston, TX (United States)

1997-09-01

6

Diffusivity of nitrous oxide in N-methyldiethanolamine + diethanolamine + water  

SciTech Connect

The tertiary amine N-methyldiethanolamine and the secondary amine diethanolamine are commonly used in the gas-treating industry as chemical solvents for the removal of acid gases such as CO{sub 2} and H{sub 2}S. The diffusion coefficients for nitrous oxide in aqueous solutions consisting of N-methyldiethanolamine (MDEA) and diethanolamine (DEA) were measured over the temperature range 293--353 K for a total amine concentration of 50 mass % and for the mass ratio of DEA to MDEA varying from 0.0441 to 0.588. The experimental diffusion coefficients were found to be relatively insensitive to the mass ratio of amines.

Rinker, E.B.; Russell, J.W.; Tamimi, A.; Sandall, O.C. [Univ. of California, Santa Barbara, CA (United States). Dept. of Chemical Engineering

1995-05-01

7

Viscosity of aqueous solutions of n-methyldiethanolamine and of diethanolamine  

SciTech Connect

Aqueous solutions of alkanolamines such as monoethanolamine (MEA), diethanolamine (DEA), N-methyldiethanolamine (MDEA), di-2-propanolamine (DIPA), and bis[2-(hydroxyamino)ethyl] ether (DGA) are good solvents for the removal of acid gases such as CO[sub 2] and H[sub 2]S from the gas streams of many processes in the natural gas, petroleum, ammonia synthesis, and some chemical industries. The viscosity of aqueous solutions of methyldiethanolamine (MDEA) and of diethanolamine (DEA) have been measured at five temperatures in the range 25--80 C throughout the whole concentration range. The viscosity has been correlated as a function of composition for use in industrial calculations.

Teng, T.T.; Maham, Y.; Hepler, L.G.; Mather, A.E. (Univ. of Alberta, Edmonton, Alberta (Canada))

1994-04-01

8

Selective removal of hydrogen sulphide by MDEA solutions  

SciTech Connect

When compared with primary or secondary amines, tertiary amines possess both ''thermodynamic'' and ''kinetic'' selectivity for removal of H/sub 2/S from mixtures of hydrogen sulphide and carbondioxide. One of these amines, methyl-diethanolamine, is used industrially as an aqueous solution, but the selectivity achieved may be less than that can be calculated by simply taking into account the alkalinity of the solution. Gas absorption experiments in the stirred cell confirmed that CO/sub 2/ reacts in aqueous MDEA solutions where the rate is proportional to the amine concentration. On the other hand, no reaction took place when a nonaqueous solution of MDEA in n-propanol was used. These results confirmed therefore that MDEA acted as a homogeneous catalyst for CO/sub 2/ hydrolysis.

Alper, E.; Al-Ramadhan, A.

1987-01-01

9

Effect of heat stable salts on MDEA solution corrosivity: Part 2  

SciTech Connect

A comprehensive coupon corrosion testing program was undertaken to address the effect of various heat stable salts on methyldiethanolamine (MDEA) corrosivity to carbon steel and various stainless steels. Corrosion rates of carbon steel, 304SS, 316SS and 410SS liquid and vapor coupons towards MDEA, and MDEA containing various anions, at 180 F and 250 F, were measured in a reactor. Corrosion results of two refinery plant solutions before and after caustic neutralization were also performed. Based on these results, guidelines were determined for heat stable amine salt (HSAS) levels of oxalates, sulfates, formates, acetates and thiosulfates. In addition, caustic neutralization guidelines for MDEA heat stable salts were determined. Ongoing results include MDEA corrosivity with succinates, and malonates, glycolates, SO{sub 2} and ammonia.

Rooney, P.C.; DuPart, M.S.; Bacon, T.R. [Dow Chemical Co., Freeport, TX (United States)

1997-04-01

10

Viscosity, density, and surface tension of binary mixtures of water and N-methyldiethanolamine and water and diethanolamine and tertiary mixtures of these amines with water over the temperature range 20--100[degree]C  

Microsoft Academic Search

Aqueous solutions of N-methyldiethanolamine (MDEA) and diethanolamine (DEA) are widely used in the industrial treatment of acid gas streams containing H[sub 2]S and CO[sub 2]. The density and viscosity of aqueous solutions of N-methyldiethanolamine were measured over the temperature range 60--100 C. The density and viscosity of aqueous solutions of diethanolamine and diethanolamine + N-methyldiethanolamine were measured over the temperature

Edward B. Rinker; David W. Oelschlager; A. Tomas Colussi; Kenneth R. Henry; Orville C. Sandall

1994-01-01

11

Diffusivity of nitrous oxide in aqueous solutions of N-methyldiethanolamine and diethanolamine from 293 to 368 K  

Microsoft Academic Search

The diffusion coefficients for nitrous oxide in aqueous solutions of diethanolamine (DEA) and N-methyldiethanolamine (MDEA) were determined using a wetted-sphere absorber over the temperature range 293--368 K. The ranges of amine concentrations covered in the experiments were 10--30 mass % for DEA and 10--50 mass % for MDEA. The diffusion coefficients indicated a linear dependence on amine concentration, but the

A. Tamimi; E. B. Rinker; O. C. Sandall

1994-01-01

12

Operating costs cut 60% with amine switch. [Methyldiethanolamine and diethanolamine  

SciTech Connect

At the Waveland, Miss., facility of United Gas Pipe Line Co., a methyldiethanolamine (MDEA) unit was supplemented by a smaller diethanolamine (DEA) unit. With the units running in parallel, product gas specifications could be met. Each unit was treating about one-half the 30 MMscfd flow of sour gas. Natural gas, purchased from nearby producers, comes into the plant containing 40-60 ppm H/sub 2/S and 4.8% CO/sub 2/. Although the absorber of the MDEA unit was adequate to handle the gas flow and remove the H/sub 2/S to specification, the reboiler capacity was not sufficient to meet a 2% CO/sub 2/ specification. MDEA concentration was limited to less than 40% by potential corrosion problems. The DEA unit was more expensive to operate, requiring sweet processed gas as boiler fuel, and consumed twice as much electricity as the MDEA unit. The combined outlet gas from the two units met volume requirements and specifications. But the system presented operational problems. Repeated foaming occurred with the MDEA unit. Daily losses of solvent were as much as 250 gal. By closely monitoring the system, United Gas was able to reduce foaming significantly by minimizing contamination with liquid hydrocarbons which had been entering with the feed gas during line surges. Extra labor was required. Several approaches were investigated involving equipment modifications and new materials. As a result of the study, United Gas concluded that the system could be optimized and all incoming gas treated in one unit by switching solvent. Conventional MDEA was replaced by a specially formulated MDEA based solvent with low foaming tendency (Union Carbide Corp.'s Ucarsol HS Solvent 101). It could be used at a 50% concentration in aqueous solution without apparent corrosion.

Not Available

1984-01-09

13

Diffusivity of nitrous oxide in aqueous solutions of N-methyldiethanolamine and diethanolamine from 293 to 368 K  

SciTech Connect

The diffusion coefficients for nitrous oxide in aqueous solutions of diethanolamine (DEA) and N-methyldiethanolamine (MDEA) were determined using a wetted-sphere absorber over the temperature range 293--368 K. The ranges of amine concentrations covered in the experiments were 10--30 mass % for DEA and 10--50 mass % for MDEA. The diffusion coefficients indicated a linear dependence on amine concentration, but the temperature dependence was nonlinear. It was found that the diffusivity of N[sub 2]O in aqueous DEA is always less than that in aqueous MDEA under equivalent conditions of amine concentration and temperature.

Tamimi, A.; Rinker, E.B.; Sandall, O.C. (Univ. of California, Santa Barbara, CA (United States). Dept. of Chemical and Nuclear Engineering)

1994-04-01

14

Viscosity, density, and surface tension of binary mixtures of water and N-methyldiethanolamine and water and diethanolamine and tertiary mixtures of these amines with water over the temperature range 20--100[degree]C  

SciTech Connect

Aqueous solutions of N-methyldiethanolamine (MDEA) and diethanolamine (DEA) are widely used in the industrial treatment of acid gas streams containing H[sub 2]S and CO[sub 2]. The density and viscosity of aqueous solutions of N-methyldiethanolamine were measured over the temperature range 60--100 C. The density and viscosity of aqueous solutions of diethanolamine and diethanolamine + N-methyldiethanolamine were measured over the temperature range 20--100 C. The surface tension of aqueous solutions of the above mixtures was measured over the temperature range 20--80 C. The concentration ranges were 10--50 mass % N-methyldiethanolamine, 10--30 mass % diethanolamine, and 50 mass % total amine concentration with mass ratios of 0.0441--0.5883 (diethanolamine to N-methyldiethanolamine). The measured quantities were found to be in agreement with the literature where data were available.

Rinker, E.B.; Oelschlager, D.W.; Colussi, A.T.; Henry, K.R.; Sandall, O.C. (Univ. of California, Santa Barbara, CA (United States). Dept. of Chemical and Nuclear Engineering)

1994-04-01

15

Diffusion coefficients significant in modeling the absorption rate of carbon dioxide into aqueous blends of N-methyldiethanolamine and diethanolamine and of hydrogen sulfide into aqueous N-methyldiethanolamine  

SciTech Connect

Absorption rates of gaseous CO{sub 2} into aqueous blends of N-methyldiethanolamine (MDEA) and diethanolamine (DEA) and of gaseous H{sub 2}S into aqueous MDEA were measured in a quiescent, inverted-tube diffusiometer by monitoring the rate of pressure drop. A numerical model for absorption, diffusion, and reaction of CO{sub 2} and H{sub 2}S in blends of MDEA, DEA, and water was developed. The model was used to regress diffusion coefficients of bicarbonate, carbamate, and MDEAH{sub 2}CO{sub 3} for the case of CO{sub 2} absorption and of bisulfide ion for the case of H{sub 2}S absorption from measured absorption rates. CO{sub 2} absorption rates and diffusion coefficients of bicarbonate, carbamate, and MDEAH{sub 2}CO{sub 3} were obtained at 298.2 K and 318.2 K in aqueous solutions containing 50 mass % total amine at DEA:MDEA mole ratios of 1:20, 1:4, 1L3, and 2:3. H{sub 2}S absorption rates and diffusion coefficients of bisulfide ion were obtained at 298.2 K and 318.2 K in aqueous solutions containing 20, 35, and 50 mass % MDEA.

Adams, M.E.; Marshall, T.L.; Rowley, R.L. [Brigham Young Univ., Provo, UT (United States). Dept. of Chemical Engineering] [Brigham Young Univ., Provo, UT (United States). Dept. of Chemical Engineering

1998-07-01

16

N-methyldiethanolamine: A multifunctional structure-directing agent for the synthesis of SAPO and AlPO molecular sieves.  

PubMed

In the present study, N-methyldiethanolamine (MDEA) is demonstrated to be a multifunctional structure-directing agent for the synthesis of aluminophosphate-based molecular sieves. Four types of molecular sieves, including SAPO-34, -35, AlPO-9 and -22, are for the first time acquired with MDEA as a novel template. The phase selectivity of the present synthesis is found to be condition-dependent. SAPO-34 (CHA) crystallizes from a conventional hydrothermal system with a higher MDEA concentration. When using MDEA as both the template and solvent, pure SAPO-35 (LEV) is obtained from the synthetic gel with a high P2O5/Al2O3 ratio of (2-3), in which the concentration of MDEA could be varied in a wide range. AlPO-9 and AlPO-22 (AWW) are synthesized under the similar conditions to SAPO-35, except without the addition of Si source. The physicochemical properties of the obtained samples are investigated by XRD, XRF, SEM, N2 physisorption, TG-DSC, and various NMR spectra ((13)C, (29)Si, (27)Al and (31)P). Both SAPO-34 and SAPO-35 show good thermal stability, large surface area, and high pore volume. The catalytic performance of SAPO-34 is evaluated by the methanol-to-olefins (MTO) reaction and a good (C2H4+C3H6) selectivity of 82.7% has been achieved. PMID:25616250

Wang, Dehua; Tian, Peng; Fan, Dong; Yang, Miao; Gao, Beibei; Qiao, Yuyan; Wang, Chan; Liu, Zhongmin

2015-05-01

17

Lethal monointoxication by overdosage of MDEA.  

PubMed

A 19-year-old man died after the intake of ten tablets of Ecstasy containing 3,4-methyl-enedioxy-N-ethylamphetamine (MDEA) as the main active ingredient. According to an eyewitness the symptoms of intoxication were strong sweating, sudden aggressiveness followed by hallucinations, subsequent failure of motoric coordination, severe spasms of arms and back, complete depression of the respiratory system, unconsciousness, and collapse. Resuscitation by an emergency doctor failed. Major autopsy findings were severe vascular congestion of all internal organs, liquid post-mortem blood, numerous subpleural and subepicardial petechial haemorrhages. By GC/MS analysis, MDEA was found in large amounts in serum (12 mg/l in femoral vein, 22 mg/l in heart blood serum), urine (201 mg/l), brain (18 to 28 mg/l) and in other tissue samples. Scalp-hair was highly positive for MDEA (17 ng/mg). Besides MDEA and its metabolites only trace amounts of MDMA could be found in urine and blood; no other drugs were detected. It can be concluded that the cause of death was a monointoxication by overdosage of MDEA. PMID:9549899

Weinmann, W; Bohnert, M

1998-01-30

18

Modeling CO{sub 2} and H{sub 2}S solubility in MDEA and DEA: Design implications  

SciTech Connect

The solubility of H{sub 2}S and CO{sub 2} in aqueous alkanolamines affects solution capacity and the required circulation rate for acid gas absorption. These thermodynamics also determine the relationship of steam rate and the lean loading of the solution which in turn sets the leak of acid gas from the top of the absorber. Finally, the mechanisms of mass transfer and the role of kinetics, especially in stripping, depend on the vapor/liquid equilibria. Published measurements of CO{sub 2} and H{sub 2}S solubility in methyldiethanolamine (MDEA) and diethanolamine (DEA) are not in general agreement, especially at low loading of acid gas. The available sets of solubility data have been regressed with the AspenPlus electrolyte/NRTL model. All of the parameters and constants that make up this model have been carefully evaluated. Independent thermodynamic data such as freezing point and heat of mixing have been included in the regression to strengthen the estimates of model parameters. The parameters for each set of solubility data have been evaluated in an attempt to determine which set is correct. Each evaluated model has been used to calculate the acid gas capacity and minimum stripping steam rate for several industrial cases of acid gas absorption/stripping.

Rochelle, G.T.; Posey, M. [Univ. of Texas, Austin, TX (United States)

1996-12-31

19

Fatal poisoning by MDMA (ecstasy) and MDEA: A case report  

Microsoft Academic Search

The first observation of lethal recreational use of MDMA (ecstasy) and MDEA in Italy is reported, together with extensive toxicological and histopathological documentation. Findings such as disseminated intravascular coagulation, rarely reported before, are colocated in the framework of the toxic syndrome for a better definition of criteria for forensic diagnosis.

Vittorio Fineschi; Alessandra Masti

1996-01-01

20

Novel Chromosomally Encoded Multidrug Efflux Transporter MdeA in Staphylococcus aureus  

PubMed Central

Antibiotic efflux is an important mechanism of resistance in pathogenic bacteria. Here we describe the identification and characterization of a novel chromosomally encoded multidrug resistance efflux protein in Staphylococcus aureus, MdeA (multidrug efflux A). MdeA was identified from screening an S. aureus open reading frame expression library for resistance to antibiotic compounds. When overexpressed, MdeA confers resistance on S. aureus to a range of quaternary ammonium compounds and antibiotics, but not fluoroquinolones. MdeA is a 52-kDa protein with 14 predicted transmembrane segments. It belongs to the major facilitator superfamily and is most closely related, among known efflux proteins, to LmrB of Bacillus subtilis and EmrB of Escherichia coli. Overexpression of mdeA in S. aureus reduced ethidium bromide uptake and enhanced its efflux, which could be inhibited by reserpine and abolished by an uncoupler. The mdeA promoter was identified by primer extension. Spontaneous mutants selected for increased resistance to an MdeA substrate had undergone mutations in the promoter for mdeA, and their mdeA transcription levels were increased by as much as 15-fold. The mdeA gene was present in the genomes of all six strains of S. aureus examined. Uncharacterized homologs of MdeA were present elsewhere in the S. aureus genome, but their overexpression did not mediate resistance to the antibacterials tested. However, MdeA homologs were identified in other bacteria, including Bacillus anthracis, some of which were shown to be functional orthologs of MdeA. PMID:14982783

Huang, Jianzhong; O'Toole, Paul W.; Shen, Wei; Amrine-Madsen, Heather; Jiang, Xinhe; Lobo, Neethan; Palmer, Leslie M.; Voelker, LeRoy; Fan, Frank; Gwynn, Michael N.; McDevitt, Damien

2004-01-01

21

Operating data from a commercial MDEA gas treater  

SciTech Connect

Methyl diethanolamine (MDEA) is a tertiary amine that has the capability to selectively remove H/sub 2/S from natural gas while leaving the bulk of the CO/sub 2/ present in the residue gas stream. Known areas of application for MDEA plants include the enrichment of sulfur plant feed, recovery of H/sub 2/S from sulfur plant tail gas, and treating of natural gas for selective removal of H/sub 2/S. Goar and others have discussed the benefits associated with sulfur plant feed enrichment. This paper discusses the results taken from an operating MDEA gas treater that was designed to slip 50-60 percent of the CO/sub 2/ in the inlet feed to residue and still meet the specification of 1 grain/1-0 SCF H/sub 2/S. It is demonstrated that the H/sub 2/S in the residue gas did not change at any circulation rate until the stripping rate on the stripper dropped sufficiently low. CO/sub 2/ slippage decreased as the circulation rate increased. H/sub 2/S removal to less than 1 ppm in the residue gas is maintained at amine temperatures as high as 145/degree/F. CO/sub 2/ slippage decreased as amine temperature increased. 3 refs.

Ammons, H.L.; Sitton, D.M.

1981-01-01

22

Enthalpy of solution of carbon dioxide in (water + monoethanolamine, or diethanolamine, or N -methyldiethanolamine) and (water + monoethanolamine + N -methyldiethanolamine) at T = 298.15 K  

Microsoft Academic Search

Measurements of the enthalpy of solution for carbon dioxide in (water + monoethanolamine, or diethanolamine, or N -methyldiethanolamine) and in (water + monoethanolamine +N -methyldiethanolamine) at T= 298.15 K have been made by isothermal displacement calorimetry. The estimated uncertainty is between ±1 and 2 per cent. The results are compared with previous measurements made by isothermal flow calorimetry, isoperibol calorimetry

Alan E. Mather

2000-01-01

23

Converting to DEA/MDEA mix ups sweetening capacity  

SciTech Connect

Mixing amines can be the best method for increasing capacity or improving efficiency in an amine sweetening unit. In many cases, it may be possible simply to add a second amine to the existing solution on the fly, or as the unit is running. Union Pacific Resources` Bryan, Tex., gas plant provides one example. The plant was converted from diethanolamine (DEA) to a DEA/MDEA (methyl DEA) mixture after analysis by TSWEET, a process-simulation program. After conversion, CO{sub 2} levels in the sales gas fell to less than pipeline specifications. Data were taken for the absorber at a constant amine circulation of 120 gpm. A comparison of the performance data to the values calculated by the program proved the accuracy of TSWEET. The conversion and performance of the plant are described.

Spears, M.L. [Union Pacific Resources, Bryan, TX (United States); Hagan, K.M. [Union Pacific Resources, Ft. Worth, TX (United States); Bullin, J.A.; Michalik, C.J. [Bryan Research and Engineering, Bryan, TX (United States)

1996-08-12

24

Intentional overdose and death with 3,4-methylenedioxyethamphetamine (MDEA; "Eve"): case report.  

PubMed

We report a case of suicide following ingestion of a large dose of 3,4-methylenedioxyethamphetamine (MDEA, "Eve") in a 27-year-old woman with a history of depression. Several days before her death, she had attempted suicide with benzodiazepines resulting in a 24-hour hospital admission; at that time, no physiologic abnormalities were detected. Findings on autopsy were nonspecific. Toxicologic analysis showed a high concentration of MDEA and the appearance of benzodiazepines in body fluids. Ethanol and other drugs of abuse were not found. We discuss the clinical manifestations, toxicologic syndromes, and mechanisms of death with amphetamine intoxication. MDEA intoxication in young people may result in sudden death. PMID:9662110

Arimany, J; Medallo, J; Pujol, A; Vingut, A; Borondo, J C; Valverde, J L

1998-06-01

25

Piperazine-induced occupational asthma  

SciTech Connect

Asthmatic reactions were studied among some 130 factory workers who handled amines and other chemicals. Among present employees, we found 15 cases of asthma associated with occupational exposure to chemicals; among former employees there were at least 18. The inducing agent was judged to be piperazine in 29 persons and ethylenediamine (EDA) in three. The asthma was of the late or dual type; immediate reactions alone were to seen. No one had attacks of asthma before employment, and atopic subjects were not preferentially affected. Routine spirometry revealed airway obstruction in fewer than half of the recent cases. Tests of nonspecific bronchial reactivity with methacholine in six subjects with recent asthma showed hyperactivity in five, while tow subjects with earlier asthma did not have hyperactivity. Bronchial provocation tests with piperazine in one subject were positive both in the factory and in the laboratory. The level of piperazine was 1.2 mg/m3 time-weighted average (TWA) in a work place associated with induction of the asthmatic state, and 0.3 mg/m3 in a place connected with attacks in ''sensitized'' subjects.

Hagmar, L.; Bellander, T.; Bergoeoe, B.; Simonsson, B.G.

1982-03-01

26

Solubility of carbon dioxide and hydrogen sulfide in aqueous N-methyldiethanolamine solutions  

SciTech Connect

In this work, 72 new experimental solubility data points for H{sub 2}S and CO{sub 2} mixtures in aqueous N-methyldiethanol amine (MDEA) solutions at different methane partial pressures (up to 69 bara) are presented. They are correlated using an electrolyte equation of state (E-EOS) thermodynamic model. This model has already been used to estimate the CO{sub 2} solubility in aqueous MDEA (Huttenhuis et al. Fluid Phase Equilib. 2008, 264, 99-112) and the H{sub 2}S solubility in aqueous MDEA (Huttenhuis et al. Int. J. Oil, Gas Coal Technol. 2008, 1, 399-424). Here, the model is further extended to predict the behavior of CO{sub 2} and H{sub 2}S when they are present simultaneously in aqueous MDEA. The application of an equation of state is a new development for this type of system, i.e., of acid-gas-amine systems. The molecular interactions are described by Schwarzentruber et al.'s modification of the Redlich-Kwong-Soave equation of state, with terms added to account for ionic interactions in the liquid phase. The model is used to describe acid-gas solubility data for the CO{sub 2}-H{sub 2}S-MDEA-H{sub 2}O system reported in the open literature and experimental data reported here for the CO{sub 2}-H{sub 2}S-MDEA-H{sub 2}O-CH{sub 4} system.

Huttenhuis, P.J.G.; Agrawal, N.J.; Versteeg, G.F. [Procede Group BV, Enschede (Netherlands)

2009-04-15

27

Surface tension of binary mixtures of water + N-methyldiethanolamine and ternary mixtures of this amine and water with monoethanolamine, diethanolamine, and 2-amino-2-methyl-1-propanol from 25 to 50 C  

Microsoft Academic Search

The surface tension of aqueous solutions of N-methyldiethanolamine and diethanolamine + N-methyldiethanolamine, monoethanolamine + N-methyldiethanolamine and 2-amino-2-methyl-1-propanol + N-methyldiethanolamine was measured at temperatures from 25 C to 50 C. For binary mixtures the concentration range was 0--50 mass % N-methyldiethanolamine, and for the tertiary mixtures the concentration range for each amine was 0--50 mass %. The experimental values were correlated

Estrella Alvarez; Raquel Rendo; Begoña Sanjurjo; M. Sanchez-Vilas; José M. Navaza

1998-01-01

28

21 CFR 520.1806 - Piperazine suspension.  

...c) of this chapter. (d) Conditions of use in dogs —(1) Indications for use. For the removal of roundworms (Toxocara canis and Toxascaris leonina ). (2) Dosage. Administer 20 to 30 mg piperazine base per pound body weight as a...

2014-04-01

29

21 CFR 520.1806 - Piperazine suspension.  

Code of Federal Regulations, 2010 CFR

...c) of this chapter. (d) Conditions of use in dogs —(1) Indications for use . For the removal of roundworms (Toxocara canis and Toxascaris leonina ). (2) Dosage . Administer 20 to 30 mg piperazine base per pound body weight as a...

2010-04-01

30

21 CFR 520.1806 - Piperazine suspension.  

Code of Federal Regulations, 2011 CFR

...c) of this chapter. (d) Conditions of use in dogs —(1) Indications for use . For the removal of roundworms (Toxocara canis and Toxascaris leonina ). (2) Dosage . Administer 20 to 30 mg piperazine base per pound body weight as a...

2011-04-01

31

21 CFR 520.1806 - Piperazine suspension.  

Code of Federal Regulations, 2013 CFR

...c) of this chapter. (d) Conditions of use in dogs —(1) Indications for use . For the removal of roundworms (Toxocara canis and Toxascaris leonina ). (2) Dosage . Administer 20 to 30 mg piperazine base per pound body weight as a...

2013-04-01

32

21 CFR 520.1806 - Piperazine suspension.  

Code of Federal Regulations, 2012 CFR

...c) of this chapter. (d) Conditions of use in dogs —(1) Indications for use . For the removal of roundworms (Toxocara canis and Toxascaris leonina ). (2) Dosage . Administer 20 to 30 mg piperazine base per pound body weight as a...

2012-04-01

33

Solubility of hydrogen sulfide in aqueous mixtures of monoethanolamine with N-methyldiethanolamine  

SciTech Connect

Alkanolamine aqueous solutions are frequently used for the removal of acidic gases, such as CO[sub 2] and H[sub 2]S, from gas streams in the natural gas and synthetic ammonia industries and petroleum chemical plants. The solubilities of hydrogen sulfide in aqueous mixtures of monoethanolamine (MEA) with N-methyl-diethanolamine (MDEA) have been measured at 40, 60, 80, and 100C and at partial pressures of hydrogen sulfide ranging from 1.0 to 450 kPa. The mixtures of alkanolamines studied are 4.95 kmol/m[sup 3] MEA, 3.97 kmol/m[sup 3] MEA + 0.51 kmol/m[sup 3] MDEA, 2.0 kmol/m[sup 3] MEA + 1.54 kmol/m[sup 3] MDEA, and 2.57 kmol/m[sup 3] MDEA aqueous solutions. The solubilities of hydrogen sulfide in aqueous alkanolamine solutions are reported as functions of the partial pressure of hydrogen sulfide at the temperatures of 40-100C.

Meng Hui Li; Keh Perng Shen (Chung Yuan Christian Univ., Chung Li (Taiwan, Province of China). Dept. of Chemical Engineering)

1993-01-01

34

Surface tension of binary mixtures of water + N-methyldiethanolamine and ternary mixtures of this amine and water with monoethanolamine, diethanolamine, and 2-amino-2-methyl-1-propanol from 25 to 50 C  

SciTech Connect

The surface tension of aqueous solutions of N-methyldiethanolamine and diethanolamine + N-methyldiethanolamine, monoethanolamine + N-methyldiethanolamine and 2-amino-2-methyl-1-propanol + N-methyldiethanolamine was measured at temperatures from 25 C to 50 C. For binary mixtures the concentration range was 0--50 mass % N-methyldiethanolamine, and for the tertiary mixtures the concentration range for each amine was 0--50 mass %. The experimental values were correlated with temperature and mole fraction. The maximum deviation in both cases was always less than 0.5%.

Alvarez, E. [Univ. of Vigo (Spain). Dept. of Chemical Engineering] [Univ. of Vigo (Spain). Dept. of Chemical Engineering; Rendo, R.; Sanjurjo, B.; Sanchez-Vilas, M.; Navaza, J.M. [Univ. of Santiago de Compostela (Spain). Dept. of Chemical Engineering] [Univ. of Santiago de Compostela (Spain). Dept. of Chemical Engineering

1998-11-01

35

CO/sub 2/ desorption from DEA and DEA-promoted MDEA  

SciTech Connect

CO/sub 2/ desorption rates were measured in 2 M diethanolamine and 2 M diethanolamine-promoted methyldiethanolamine solutions at 25{sup 0}C. CO/sub 2/ vapor pressure equilibria were estimated through extrapolation of the measured rates. The estimated vapor pressures were used to calculate apparent rate constants, and the resulting rate constants were interpreted as a function of CO/sub 2/ loading. The rate constants derived from the low driving force desorption experiments were compared with values obtained from high driving force, irreversible absorption experiments. In the absorption work, the effect of varied driving force on the resulting apparent rate constant was studied. The experimental results confirm that the absorption experiments were not affected by diffusion constraints. The agreement between the apparent rate constants determined from the absorption and desorption techniques was found to be very good.

Critchfield, J.E.; Rochelle, G.T. (Dept. of Chemical Engineering, The Univ. of Texas at Austin (US))

1988-01-01

36

Solubility of mixtures of hydrogen sulfide and carbon dioxide in aqueous N-methyldiethanolamine solutions  

SciTech Connect

Aqueous solutions of alkanolamines are commonly used to strip acid gases (H[sub 2]S and CO[sub 2]) from streams contaminated with these components. The two most widely used amines are monoethanolamine (MEA) and diethanolamine (DEA). The solubilities of mixtures of hydrogen sulfide and carbon dioxide in a 35 wt% (3.04 kmol/m[sup 3]) aqueous solution of N-methyldiethanolamine at 40 and 100C have been measured. Partial pressures of the acid gases ranged from 0.006 to 101 kPa at 40C and from 4 to 530 kPa at 100C.

Jou, Fang Yuan; Carroll, J.J.; Mather, A.E.; Otto, F.D. (Univ. of Alberta, Edmonton, Alberta (Canada). Dept. of Chemical Engineering)

1993-01-01

37

Engineering of copper molybdates: Piperazine dictated pseudopolymorphs  

NASA Astrophysics Data System (ADS)

The hydrothermal syntheses, crystal structures and magnetic behavior of two compositionally different piperazine pillared copper molybdates, [{Cu( pip) 0.5}MoO 4] ( 1) and a hitherto unknown [Cu( pip)MoO 4] ( pip = piperazine) ( 2), are reported. Both 1 and 2 exhibit three-dimensional covalent frameworks constructed from bimetallic oxide layers pillared by piperazine; however, the {CuMoO 4} networks are quite distinct. The Cu-Mo-O layers in 1 are made of edge-shared {CuO 4N} square pyramidal pairs linked through {MoO 4} tetrahedra, in contrast to the sheets in 2 that are built of corner-sharing {MoO 4} tetrahedra and {CuO 3N 2} square pyramids. Self assembly of the two pseudopolymorphs, 1 and 2, is interpreted in terms of molecular recognition between reasonable soluble molecular species in the supramolecular reaction along the mechanistic approach proposed by Ramanan and Whittingham for rationalizing metal-organic framework structures. Crystal data: 1, Triclinic, space group P-1, a = 5.5765(8) Å, b = 6.8304(10) Å, c = 9.2379(14) Å, ? = 100.688(2)°, ? = 101.462(2)°, ? = 112.624(2)°, Z = 2; 2, Orthorhombic, space group Pbca, a = 11.3899(11) Å, b = 10.7726(10) Å, c = 13.2541(12) Å, Z = 8.

Pavani, Katikaneani; Singh, Monika; Ramanan, Arunachalam; Lofland, Samuel E.; Ramanujachary, Kandalam V.

2009-09-01

38

21 CFR 520.1802 - Piperazine-carbon disulfide complex oral dosage forms.  

Code of Federal Regulations, 2010 CFR

...Piperazine-carbon disulfide complex oral dosage forms. 520.1802...ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED...FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS...Piperazine-carbon disulfide complex oral dosage...

2010-04-01

39

21 CFR 520.1802c - Piperazine-carbon disulfide complex with phenothiazine suspension.  

Code of Federal Regulations, 2010 CFR

...2010-04-01 false Piperazine-carbon disulfide complex with phenothiazine suspension... § 520.1802c Piperazine-carbon disulfide complex with phenothiazine suspension...contains 5 grams of piperazine-carbon disulfide complex and 0.83 gram of...

2010-04-01

40

Survey and Down-Selection of Acid Gas Removal Systems for the Thermochemical Conversion of Biomass to Ethanol with a Detailed Analysis of an MDEA System  

SciTech Connect

The first section (Task 1) of this report by Nexant includes a survey and screening of various acid gas removal processes in order to evaluate their capability to meet the specific design requirements for thermochemical ethanol synthesis in NREL's thermochemical ethanol design report (Phillips et al. 2007, NREL/TP-510-41168). MDEA and selexol were short-listed as the most promising acid-gas removal agents based on work described in Task 1. The second report section (Task 2) describes a detailed design of an MDEA (methyl diethanol amine) based acid gas removal system for removing CO2 and H2S from biomass-derived syngas. Only MDEA was chosen for detailed study because of the available resources.

Nexant, Inc., San Francisco, California

2011-05-01

41

A status report on the investigation of the effects of antioxidants upon oxygen degradation of methyldiethanolamine  

SciTech Connect

Natural gas production is an important source of energy for the country. The gas directly from the gas fields is not suitable for consumption due to the presence of acidic impurities. The process of gas treating separates impurities such as carbon dioxide-(CO/sub 2/), hydrogen sulfide (H/sub 2/S), and sulfur dioxide (SO/sub 2/) from the gas stream. Industrial processes such as hydrogen manufacture and ammonia production also require acid gas removal systems. The oxygen degradation reactions of MDEA (Melhyl Diethanolamine) solutions were investigated. Several primary and secondary antioxidants were tested and found to be ineffective in the first series of batch reactor experiments at 195/sup 0/F and 50 psig O/sub 2/. This may be due to an excessively high oxygen pressure whereby the inhibitor reacted with the oxygen directly in a short period of time and thus the amine was not protected against degradation. Another possibility is that the severe experimental conditions may accelerate heat stable salts formation reactions at a constant rate. The current preliminary results are indicative that oxygen degradation reactions are quite complicated. Further studies are needed to determine the best antioxidants needed for amine sweetening systems.

Pundari, A.N.; Singh, M.; Bullin, J.A.

1987-01-01

42

N-(1H-Indol-3-yl­methyl­idene)-4-methyl­piperazin-1-amine  

PubMed Central

In the title compound, C14H18N4, the piperazine ring is in a slightly distorted chair conformation. The indole ring system is twisted from the piperazine ring, making a dihedral angle of 7.27?(11)°. In the crystal, N—H?N hydrogen bonds link mol­ecules into chains along [10-1]. PMID:24454132

Kavitha, Channappa N.; Jasinski, Jerry P.; Anderson, Brian J.; Yathirajan, H. S.; Kaur, Manpreet

2013-01-01

43

Synthesis and characterization of the novel phosphonates- and phosphonothioate-piperazine as flame retardants for cotton  

Technology Transfer Automated Retrieval System (TEKTRAN)

Tetraethyl piperazine-1,4-diyldiphosphonate (PDP) and O,O,O',O'-tetramethyl piperazine-1,4-diyldiphosphonothioate (PDSP) were synthesized in one simple step and their structures were confirmed by 1H and 13C nuclear magnetic resonance (NMR) spectroscopy and elemental analysis (EA). Print cloth, twil...

44

[Design and synthesis of aralkyl-ketone piperazine derivatives and their antalgic activities].  

PubMed

To synthesize aralkyl-ketone piperazine derivatives as analgesic agents, the N atom of the one side of piperazine ring is protected by formyl group firstly, then the unprotected N atom is alkylated to prepare aralkyl-ketone piperazine derivatives. Their analgesic biological activities were well studied by mice writhing model, rat hot plate model and rat tail flick model. Sixty four compounds were synthesized and pharmacological tests in vivo revealed these compounds have potent analgesic activities, especially compound I12, I14, I14 I21 and I37. These four compounds are more worthy for further research. PMID:18300474

Li, Jian-qi; Huang, Li-ying; Chen, Jian-xin; Weng, Zhi-jie; Zhang, Chun-nian

2007-11-01

45

4-Phenyl­piperazin-1-ium dihydrogen phosphate  

PubMed Central

The title compound, C10H15N2 +·H2PO4 ?, is built up from 4-phenyl­piperazin-1-ium cations and dihydrogen phosphate anions. The inter­connection between two adjacent anions is assured by two strong O—H?O hydrogen bonds, which lead to the formation of infinite wave-like chains which spread along the a axis. The organic cations connect these chains via N—H?O hydrogen bonds. The crystal cohesion and stability are ensured by electrostatic and van der Waals inter­actions which, together with N—H?O and O—H?O hydrogen bonds, build up a two-dimensional network. PMID:21588611

Essid, Manel; Marouani, Houda; Rzaigui, Mohamed; Al-Deyab, Salem S.

2010-01-01

46

Synthesis and Characterization of Piperazine-Modified Linseed Oil Fatty Amide Coatings  

Microsoft Academic Search

Piperazine-modified fatty amide (PMF) was prepared from N,N-bis(2 hydroxy ethyl) linseed oil fatty amide and piperazine through condensation polymerization. It was further cured with butylated melamine formaldehyde in different phr (parts per hundred part of resin) (PMF-BMF). PMF and PMF-BMF systems were subjected to spectroscopic analysis to ascertain their structure and curing scheme. Thermal studies and curing behavior of these

Sharif Ahmad; S. M. Ashraf; Manawwer Alam

2006-01-01

47

Pharmacological profiles of aminoindanes, piperazines, and pipradrol derivatives.  

PubMed

Aminoindanes, piperazines, and pipradrol derivatives are novel psychoactive substances found in "Ecstasy" tablets as replacements for 3,4-methylenedioxymethamphetamine (MDMA) or substances sold as "ivory wave." The pharmacology of these MDMA- and methylphenidate-like substances is poorly known. We characterized the pharmacology of the aminoindanes 5,6-methylenedioxy-2-aminoindane (MDAI), 5-iodoaminoindane (5-IAI), and 2-aminoindane (2-AI), the piperazines meta-chlorophenylpiperazine (m-CPP), trifluoromethylphenylpiperazine (TFMPP), and 1-benzylpiperazine (BZP), and the pipradrol derivatives desoxypipradrol (2-diphenylmethylpiperidine [2-DPMP]), diphenylprolinol (diphenyl-2-pyrrolidinemethanol [D2PM]), and methylphenidate. We investigated norepinephrine (NE), dopamine (DA), and serotonin (5-hydroxytryptamine [5-HT]) uptake inhibition using human embryonic kidney 293 (HEK 293) cells that express the respective human monoamine transporters (NET, DAT, and SERT). We also evaluated the drug-induced efflux of NE, DA, and 5-HT from monoamine-preloaded cells and the binding affinity to monoamine transporters and receptors, including trace amine-associated receptor 1 (TAAR1). 5-IAI and MDAI preferentially inhibited the SERT and NET and released 5-HT. 2-AI interacted with the NET. BZP blocked the NET and released DA. m-CPP and TFMPP interacted with the SERT and serotonergic receptors. The pipradrol derivatives were potent and selective catecholamine transporter blockers without substrate releasing properties. BZP, D2PM, and 2-DPMP lacked serotonergic activity and TAAR1 binding, in contrast to the aminoindanes and phenylpiperazines. In summary, all of the substances were monoamine transporter inhibitors, but marked differences were found in their DAT vs. SERT inhibition profiles, release properties, and receptor interactions. The pharmacological profiles of D2PM and 2-DPMP likely predict a high abuse liability. PMID:24486525

Simmler, Linda D; Rickli, Anna; Schramm, York; Hoener, Marius C; Liechti, Matthias E

2014-03-15

48

Piperazine designer drugs induce toxicity in cardiomyoblast h9c2 cells through mitochondrial impairment.  

PubMed

Abuse of synthetic drugs is widespread among young people worldwide. In this context, piperazine derived drugs recently appeared in the recreational drug market. Clinical studies and case-reports describe sympathomimetic effects including hypertension, tachycardia, and increased heart rate. Our aim was to investigate the cytotoxicity of N-benzylpiperazine (BZP), 1-(3-trifluoromethylphenyl) piperazine (TFMPP), 1-(4-methoxyphenyl) piperazine (MeOPP), and 1-(3,4-methylenedioxybenzyl) piperazine (MDBP) in the H9c2 rat cardiac cell line. Complete cytotoxicity curves were obtained at a 0-20 mM concentration range after 24 h incubations with each drug. The EC50 values (?M) were 343.9, 59.6, 570.1, and 702.5 for BZP, TFMPP, MeOPP, and MDBP, respectively. There was no change in oxidative stress markers. However, a decrease in total GSH content was noted for MDBP, probably due to metabolic conjugation reactions. All drugs caused significant decreases in intracellular ATP, accompanied by increased intracellular calcium levels and a decrease in mitochondrial membrane potential that seems to involve the mitochondrial permeability transition pore. The cell death mode revealed early apoptotic cells and high number of cells undergoing secondary necrosis. Among the tested drugs, TFMPP seems to be the most potent cytotoxic compound. Overall, piperazine designer drugs are potentially cardiotoxic and support concerns on risks associated with the intake of these drugs. PMID:24968061

Arbo, Marcelo Dutra; Silva, Renata; Barbosa, Daniel José; da Silva, Diana Dias; Rossato, Luciana Grazziotin; Bastos, Maria de Lourdes; Carmo, Helena

2014-08-17

49

2-Butyl-4-chloroimidazole based substituted piperazine-thiosemicarbazone hybrids as potent inhibitors of Mycobacterium tuberculosis.  

PubMed

Here a series of 2-butyl-4-chloroimidazole based substituted piperazine-thiosemicarbazone hybrids were designed by combining three different pharmacophoric fragments in single molecular architecture. 2-Butyl-4-chloro-1-(3-(4-substituted)piperazin-1-yl)propyl)-1H-imidazole-5-carbaldehydes (4a-p) prepared by reacting carboxaldehyde 2 with N-alkyl piperazines 3a-p which were condensed with thiosemicarbazine to give desired compounds 5a-p in very good yields. Among all sixteen compounds screened for in vitro antimycobacterial activity against Mycobacterium tuberculosis H37Rv (MTB), two compounds (E)-2-((2-butyl-4-chloro-1-(3-(4-(o-tolyl) piperazin-1-yl)propyl)-1H-imidazol-5-yl)methylene)hydrazinecarbothioamide 5e and (E)-2-((2-butyl-4-chloro-1-(3-(4-(2-methoxyphenyl)piperazin-1-yl)propyl)-1H-imidazol-5-yl)methylene) hydrazine carbothioamide 5f were found to be the most potent antitubercular agents (MIC: 3.13?g/mL) with low toxicity profile. PMID:25451998

Jallapally, Anvesh; Addla, Dinesh; Yogeeswari, Perumal; Sriram, Dharmarajan; Kantevari, Srinivas

2014-12-01

50

Stereoselective synthesis of polysubstituted piperazines and oxopiperazines. Useful building blocks in medicinal chemistry.  

PubMed

Many pharmaceutical agents include piperazines or oxopiperazines as part of their core structures. The presence of substituents on these heterocycles has a significant influence on the biological activity, thus the search for efficient routes to control the substitution at different ring positions might have a crucial impact, especially to promote the use of such scaffolds in SAR studies. Many research groups have been engaged in the stereoselective synthesis of polysubstituted piperazines and oxopiperazines and in the majority of cases the stereochemistry of the final compounds is dependent on the starting material configuration. In the present minireview we have summarized some of the most significant approaches towards the stereoselective synthesis and functionalization of substituted piperazines and oxopiperazines, with a particular focus on our own contributions mainly based on readily available natural amino-acids as "chiral pool" starting materials. An efficient and scalable route to orthogonally protected 2-oxopiperazines has been developed using the corresponding diamines as key intermediates: diastereoselective elaboration of the resulting heterocycles was possible by metalation and reaction with electrophiles, leading to anti 3,5-disubstituted-oxopiperazines, in agreement with the model for a conventional 1,3-asymmetric induction. Both piperazines and tetrahydropyrazines could be prepared via LiAlH4-mediated reduction of 2-oxopiperazines, depending on reaction conditions. Finally, the diastereoselective synthesis of cyclopropane- containing analogs 2,5-diaza-bicyclo[4.1.0]heptanes was demonstrated by application of the classic Simmons-Smith reaction on enantiomerically enriched dihydro-2H-pyrazines. PMID:24758427

Mordini, Alessandro; Reginato, Gianna; Calamante, Massimo; Zani, Lorenzo

2014-01-01

51

The mechanism of action of piperazine-phosphonates derivatives in cotton fabric  

Technology Transfer Automated Retrieval System (TEKTRAN)

Piperazine-phosphonates additives are known to be very effective flame retardants on different polymeric systems, especially cotton cellulose. In order to understand their mechanism of action, we carried out the investigation of their thermal behavior on cotton fabric by, first, employing the attenu...

52

21 CFR 520.1802c - Piperazine-carbon disulfide complex with phenothiazine suspension.  

Code of Federal Regulations, 2011 CFR

21 ? Food and Drugs ? 6 ? 2011-04-01 ? 2011-04-01 ? false ? Piperazine-carbon disulfide complex with phenothiazine suspension. ? 520.1802c ? Section 520.1802c ? Food and Drugs ? FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ? ANIMAL DRUGS, FEEDS, AND...

2011-04-01

53

21 CFR 520.1802 - Piperazine-carbon disulfide complex oral dosage forms.  

Code of Federal Regulations, 2012 CFR

21 ? Food and Drugs ? 6 ? 2012-04-01 ? 2012-04-01 ? false ? Piperazine-carbon disulfide complex oral dosage forms. ? 520.1802 ? Section 520.1802 ? Food and Drugs ? FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ? ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ?...

2012-04-01

54

21 CFR 520.1802 - Piperazine-carbon disulfide complex oral dosage forms.  

Code of Federal Regulations, 2011 CFR

21 ? Food and Drugs ? 6 ? 2011-04-01 ? 2011-04-01 ? false ? Piperazine-carbon disulfide complex oral dosage forms. ? 520.1802 ? Section 520.1802 ? Food and Drugs ? FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ? ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ?...

2011-04-01

55

21 CFR 520.1802 - Piperazine-carbon disulfide complex oral dosage forms.  

21 ? Food and Drugs ? 6 ? 2014-04-01 ? 2014-04-01 ? false ? Piperazine-carbon disulfide complex oral dosage forms. ? 520.1802 ? Section 520.1802 ? Food and Drugs ? FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ? ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ?...

2014-04-01

56

21 CFR 520.1802c - Piperazine-carbon disulfide complex with phenothiazine suspension.  

Code of Federal Regulations, 2013 CFR

21 ? Food and Drugs ? 6 ? 2013-04-01 ? 2013-04-01 ? false ? Piperazine-carbon disulfide complex with phenothiazine suspension. ? 520.1802c ? Section 520.1802c ? Food and Drugs ? FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ? ANIMAL DRUGS, FEEDS, AND...

2013-04-01

57

Integration of enabling methods for the automated flow preparation of piperazine-2-carboxamide  

PubMed Central

Summary Here we describe the use of a new open-source software package and a Raspberry Pi® computer for the simultaneous control of multiple flow chemistry devices and its application to a machine-assisted, multi-step flow preparation of pyrazine-2-carboxamide – a component of Rifater®, used in the treatment of tuberculosis – and its reduced derivative piperazine-2-carboxamide. PMID:24778715

Ingham, Richard J; Battilocchio, Claudio; Hawkins, Joel M

2014-01-01

58

Thermal decomposition reactions of cotton fabric treated with piperazine-phosphonates derivatives as a flame retardant  

Technology Transfer Automated Retrieval System (TEKTRAN)

There has been a great scientific interest in exploring the great potential of the piperazine-phosphonates in flame retardant (FR) application on cotton fabric by investigating the thermal decomposition of cotton fabric treated with them. This research tries to understand the mode of action of the t...

59

The influences of piperazine-phosphonates derivatives on flame retardancy and thermal behaviors of cotton cellulose  

Technology Transfer Automated Retrieval System (TEKTRAN)

In an effort to create the environmentally-friendly flame retardants (FRs) for cotton cellulose, two phosphoramidates derivatives, tetraethyl piperazine-1,4-diyldiphosphonate (PDP) and diethyl 4-methylpiperazin-1-ylphosphoramidate (PAP), have been developed. Both were synthesized in high yield and ...

60

Piperazine-phosphonate derivatives: their flame retardant and thermal degradation properties on cotton fibers  

Technology Transfer Automated Retrieval System (TEKTRAN)

It has been known that phosphorus-nitrogen system shows greater flame resistance in cotton textiles at a lower level than phosphorus used alone. This research aims to compare the effectiveness of Tetraethyl piperazine-1,4-diyldiphosphonate (TEPP) as a flame retardant (FR) for cotton fabric to a prev...

61

Integration of enabling methods for the automated flow preparation of piperazine-2-carboxamide.  

PubMed

Here we describe the use of a new open-source software package and a Raspberry Pi(®) computer for the simultaneous control of multiple flow chemistry devices and its application to a machine-assisted, multi-step flow preparation of pyrazine-2-carboxamide - a component of Rifater(®), used in the treatment of tuberculosis - and its reduced derivative piperazine-2-carboxamide. PMID:24778715

Ingham, Richard J; Battilocchio, Claudio; Hawkins, Joel M; Ley, Steven V

2014-01-01

62

Solubility and diffusivity of N{sub 2}O and CO{sub 2} in (diethanolamine + N-methyldiethanolamine + water) and in (diethanolamine + 2-amino-2-methyl-1-propanol + water)  

SciTech Connect

Acid gases such as CO{sub 2} and H{sub 2}S are frequently removed from natural gas, synthetic natural gas, and other process gas streams by means of absorption into aqueous alkanol-amine solutions. The solubility and diffusivity of N{sub 2}O in (diethanolamine + N-methyldiethanolamine + water) and in (diethanolamine + 2-amino-2-methyl-1-propanol + water) were measured at (30, 35, and 40)C and at atmospheric pressure. Five (diethanolamine + N-methyldiethanolamine + water) and four (diethanolamine + 2-amino-2-methyl-1-propanol + water) systems were studied. The total amine mass percent in all cases was 30. A solubility apparatus was used to measure the solubility of N{sub 2}O in amine solutions. The diffusivity was measured by a wetted wall column absorber. The N{sub 2}O analogy was used to estimate the solubility and diffusivity of CO{sub 2} in (diethanolamine + N-methyldiethanolamine + water) and in (diethanolamine + 2-amino-2-methyl-1-propanol + water).

Li, M.H.; Lee, W.C. [Chung Yuan Christian Univ., Chung Li (Taiwan, Province of China). Dept. of Chemical Engineering] [Chung Yuan Christian Univ., Chung Li (Taiwan, Province of China). Dept. of Chemical Engineering

1996-05-01

63

Substituted dithiazole piperazine benzamides as novel amyloid beta peptide reducing agents.  

PubMed

Alzheimer's disease is a persistent neurodegenerative disorder of elderly characterized clinically by irreversible loss of memory due to accumulation of amyloid beta peptides within the amyloid plaques. We report the parallel synthesis and screening results of diverse substituted di-thiazole piperazine benzamides. A new compound TPI-1917-49 was identified as a promising amyloid reducing agent by lowering the levels of A? at least in two cell types and in vivo. PMID:25155386

Wang, Hongjie; Wang, Ruizhi; Lakshmana, Madepalli K; Nefzi, Adel

2014-09-15

64

Tri­chlorido­(1-ethyl­piperazin-1-ium)cobalt(II)  

PubMed Central

In the title complex, [Co(C6H15N2)Cl3], the Co2+ ion is coordinated in a distorted tetra­hedral fashion by three chloride ions and one N atom of the piperazine ring; the ring adopts a chair conformation with the N—Co and N—CEt bonds in equatorial orientations. In the crystal, mol­ecules are connected by N—H?Cl hydrogen bonds, generating (10-1) sheets. PMID:24860302

Dhieb, Abdelhamid Chiheb; Janzen, Daron E.; Rzaigui, Mohamed; Smirani Sta, Wajda

2014-01-01

65

Piperazine N-substituted naphthyridines, pyridothienopyrimidines and pyridothienotriazines: new antiprotozoals active against Philasterides dicentrarchi  

Microsoft Academic Search

New antiprotozoals active against Philasterides dicentrarchi, the causative agent of scuticociliatosis in farmed turbot and Black Sea bass-bream, have been synthesised and tested. The most active compounds posses a piperazine ring, generally N-bonded to the heterocycle, and are the 1,8-naphthyridines, 2f and 5o, the pyridothienopyrimidine (7), and the pyridothienotriazines, 8, 9, 12d, 12f, 12h, 12m and 12k. Pyridothienotriazine (12k) presents

José M Quintela; Carlos Peinador; Liliana González; Raúl Iglesias; Anabel Paramá; Francisca Álvarez; Manuel L Sanmart??n; Ricardo Riguera

2003-01-01

66

A case of levocetirizine-induced fixed drug eruption and cross-reaction with piperazine derivatives.  

PubMed

Fixed drug eruption is an uncommon adverse drug reaction caused by delayed cell-mediated hypersensitivity. Levocetirizine is an active (R)-enatiomer of cetirizine and there have been a few reports of fixed drug eruption related to these antihistamines. We experienced a case of levocetirizine-induced fixed drug eruption and cross-reaction with other piperazine derivatives confirmed by patch test. A 73-year-old female patient presented with recurrent generalized itching, cutaneous bullae formation, rash and multiple pigmentation at fixed sites after taking drugs for common cold. She took bepotastine besilate (Talion®) and levocetirizine (Xyzal®) as antihistamine. She took acetaminophen, pseudoephedrine 60 mg / triprolidine 2.5 mg (Actifed®), dihydrocodeinebitartrate 5 mg / di-methylephedrine hydrochloride 17.5 mg / chlorpheniramine maleate 1.5 mg / guaifenesin 50 mg (Codening®) and aluminium hydroxide 200 mg / magnesium carbonate 120 mg (Antad®) at the same time. Patch test was done with suspected drugs and the result was positive with levocetirizine. We additionally performed patch test for other antihistamines such as cetirizine, hydroxyzine, fexofenadine and loratadine. Piperazine derivatives (cetirizine and hydroxyzine) were positive, but piperidine derivatives (fexofenadine and loratadine) were negative to patch test. There was no adverse drug reaction when she was challenged with fexofenadine. We report a case of levocetirizine-induced fixed drug eruption confirmed by patch test. Cross-reactions were only observed in the piperazine derivatives and piperidine antihistamine was tolerant to the patient. PMID:24260733

Kim, Mi-Yeong; Jo, Eun-Jung; Chang, Yoon-Seok; Cho, Sang-Heon; Min, Kyung-Up; Kim, Sae-Hoon

2013-10-01

67

A case of levocetirizine-induced fixed drug eruption and cross-reaction with piperazine derivatives  

PubMed Central

Fixed drug eruption is an uncommon adverse drug reaction caused by delayed cell-mediated hypersensitivity. Levocetirizine is an active (R)-enatiomer of cetirizine and there have been a few reports of fixed drug eruption related to these antihistamines. We experienced a case of levocetirizine-induced fixed drug eruption and cross-reaction with other piperazine derivatives confirmed by patch test. A 73-year-old female patient presented with recurrent generalized itching, cutaneous bullae formation, rash and multiple pigmentation at fixed sites after taking drugs for common cold. She took bepotastine besilate (Talion®) and levocetirizine (Xyzal®) as antihistamine. She took acetaminophen, pseudoephedrine 60 mg / triprolidine 2.5 mg (Actifed®), dihydrocodeinebitartrate 5 mg / di-methylephedrine hydrochloride 17.5 mg / chlorpheniramine maleate 1.5 mg / guaifenesin 50 mg (Codening®) and aluminium hydroxide 200 mg / magnesium carbonate 120 mg (Antad®) at the same time. Patch test was done with suspected drugs and the result was positive with levocetirizine. We additionally performed patch test for other antihistamines such as cetirizine, hydroxyzine, fexofenadine and loratadine. Piperazine derivatives (cetirizine and hydroxyzine) were positive, but piperidine derivatives (fexofenadine and loratadine) were negative to patch test. There was no adverse drug reaction when she was challenged with fexofenadine. We report a case of levocetirizine-induced fixed drug eruption confirmed by patch test. Cross-reactions were only observed in the piperazine derivatives and piperidine antihistamine was tolerant to the patient. PMID:24260733

Kim, Mi-Yeong; Jo, Eun-Jung; Chang, Yoon-Seok; Cho, Sang-Heon; Min, Kyung-Up

2013-01-01

68

Nitrosamine formation in amine scrubbing at desorber temperatures.  

PubMed

Amine scrubbing is a thermodynamically efficient and industrially proven method for carbon capture, but amine solvents can nitrosate in the desorber, forming potentially carcinogenic nitrosamines. The kinetics of reactions involving nitrite and monoethanolamine (MEA), diethanolamine (DEA), methylethanolamine (MMEA), and methyldiethanolamine (MDEA) were determined under desorber conditions. The nitrosations of MEA, DEA, and MMEA are first order in nitrite, carbamate species, and hydronium ion. Nitrosation of MDEA, a tertiary amine, is not catalyzed by the addition of CO2 since it cannot form a stable carbamate. Concentrated and CO2 loaded MEA was blended with low concentrations of N-(2-hydroxyethyl) glycine (HeGly), hydroxyethyl-ethylenediamine (HEEDA), and DEA, secondary amines common in MEA degradation. Nitrosamine yield was proportional to the concentration of secondary amine and was a function of CO2 loading and temperature. Blends of tertiary amines with piperazine (PZ) showed n-nitrosopiperazine (MNPZ) yields close to unity, validating the slow nitrosation rates hypothesized for tertiary amines. These results provide a useful tool for estimating nitrosamine accumulation over a range of amine solvents. PMID:24956458

Fine, Nathan A; Goldman, Mark J; Rochelle, Gary T

2014-08-01

69

Binding of the Amphetamine-like 1-Phenyl-piperazine to Monoamine Transporters  

PubMed Central

The human serotonin transporter (hSERT), the human dopamine transporter (hDAT), and the human norepinephrine transporter (hNET) facilitate the active uptake of the neurotransmitters serotonin, dopamine, and norepinephrine from the synaptic cleft. Drugs of abuse such as MDMA (streetname “ecstasy”) and certain 1-phenyl-piperazine (PP) analogs such as 1-(3-chlorophenyl)-piperazine (mCPP) elicit their stimulatory effect by elevating the synaptic concentration of serotonin by blocking or reversing the normal transport activity of hSERT. Recent data suggest that certain analogs of PP may be able to counteract the addictive effect of cocaine. Little is still known about the precise mechanism by which MDMA and PP analogs function at hSERT, hDAT, and hNET and even less is known about the specific protein–ligand interactions. In this study, we provide a comprehensive biochemical examination of a repertoire of PP analogs in hSERT, hDAT, and hNET. Combined with induced fit docking models and molecular dynamics simulations of PP and 1-(3-hydroxyphenyl)-piperazine (3-OH-PP) bound to hSERT and hDAT, we present detailed molecular insight into the promiscuous binding of PP analogs in the monoamine transporters. We find that PP analogs inhibit uptake as well as induce release in all three monoamine transporters. We also find that the selectivity of the PP analogs can be adjusted by carefully selecting substituents on the PP skeleton. PMID:23019496

2012-01-01

70

4-(Furan-2-carbon­yl)piperazin-1-ium 3,5-di­nitro­benzoate  

PubMed Central

In the cation of the title salt, C9H13N2O2 +·C7H3N2O6 ?, the piperazine ring adopts a slightly distorted chair conformation. Twofold rotational disorder is exhibited by the furan ring in a 0.430?(4):0.570?(4) ratio. In the crystal, N—H?O hydrogen bonds link the ions into chains along [010]. Additional weak C—H?O inter­actions are observed, leading to a supra­molecular layer parallel to (011). PMID:24940274

Kavitha, Channappa N.; Kaur, Manpreet; Jasinski, Jerry P.; Butcher, Ray J.; Yathirajan, H.S.

2014-01-01

71

Ionic liquid-supported synthesis of piperazine derivatives as potential insecticides.  

PubMed

With the purpose of extending our efforts on the search and synthesis of new insecticides with novel acting modes, a series of novel 4-(2-(4-(pyridin-2-yl)piperazin-1-yl)ethoxy)aniline derivatives were designed based on classical serotonin receptor ligands and synthesized through the rapid ionic liquid-supported parallel synthesis with yields up to 88 %. These products were purified through the convenient washing with appropriate solvents and isolated in good yield. In addition, 27 amide or urea derivatives of anilines were also prepared. Bioassay data showed that some of the synthesized compounds displayed selective insecticidal bioactivities against tested pests. PMID:24281924

Shen, Yan; Wang, Jia-Yi; Song, Gong-Hua

2014-02-01

72

Piperazine N-substituted naphthyridines, pyridothienopyrimidines and pyridothienotriazines: new antiprotozoals active against Philasterides dicentrarchi.  

PubMed

New antiprotozoals active against Philasterides dicentrarchi, the causative agent of scuticociliatosis in farmed turbot and Black Sea bass-bream, have been synthesised and tested. The most active compounds posses a piperazine ring, generally N-bonded to the heterocycle, and are the 1,8-naphthyridines, 2f and 5o, the pyridothienopyrimidine (7), and the pyridothienotriazines, 8, 9, 12d, 12f, 12h, 12m and 12k. Pyridothienotriazine (12k) presents the same activity (Lethal Dose, LD=0.8/1.5 mg L(-1)) as the well-known antiparasitics niclosamide and oxyclozanide. PMID:12667693

Quintela, José M; Peinador, Carlos; González, Liliana; Iglesias, Raúl; Paramá, Anabel; Alvarez, Francisca; Sanmartín, Manuel L; Riguera, Ricardo

2003-03-01

73

Identification, Structure-Activity Relationships and Molecular Modeling of Potent Triamine and Piperazine Opioid Ligands  

PubMed Central

Opioid receptors are important targets for pain management. Here, we report the synthesis and biological evaluation of three positional scanning combinatorial libraries, consisting of linear triamines and piperazines. A highly potent (14 nM) and selective (IC50(?)/IC50(?) = 71; IC50(?)/IC50(?) = 714) triamine for the ?-opioid receptor was found. In addition, non-selective ?-? binders were obtained, with binding affinities of 54 nM and 22 nM for ?- and ?-opioid receptors, respectively. Structure-activity relationships of each subset are described. 3D molecular alignments based on shape similarity to internal and external query molecules were carried out. For the combinatorial chemistry dataset studied here a 1.3 similarity cut-off value was observed to be efficient in the ROCS-based alignment method. Interactions from the overlays analyzed in the binding sites of homology models of the receptors revealed specific substitution patterns for enhancing binding affinity in the piperazine series. Pharmacophore modeling of the compounds found from the three combinatorial libraries was also performed. The pharmacophore model indicated that the important feature for receptor binding activity with the ?-receptor was the presence of at least one hydrogen bond acceptor and one aromatic hydrophobic group. Whereas for the ?-receptor two binding modes emerged with one set of compounds employing the hydrogen bond acceptor and aromatic hydrophobic group, and a second set possibly via interactions with the receptor by hydrophobic and ionic salt-bridges. PMID:19576786

Yongye, Austin B.; Appel, Jon R.; Giulianotti, Marc A.; Dooley, Colette T.; Medina-Franco, Jose L.; Nefzi, Adel; Houghten, Richard A.; Martínez-Mayorga, Karina

2009-01-01

74

Enantiomeric separation and quantitation of (+/-)-amphetamine, (+/-)-methamphetamine, (+/-)-MDA, (+/-)-MDMA, and (+/-)-MDEA in urine specimens by GC-EI-MS after derivatization with (R)-(-)- or (S)-(+)-alpha-methoxy-alpha-(trifluoromethy)phenylacetyl chloride (MTPA).  

PubMed

In drug testing, the presence of methamphetamine in urine is generally confirmed by a gas chromatography-mass spectrometry (GC-MS) method. Derivatization of the compound to a perfluoroalkylamide, prior to confirmation, typically yields better chromatographic separation. Once methamphetamine is detected, a second GC-MS test is necessary to distinguish positive results from the use of over-the-counter medication, Vicks inhaler, or from use of a prescription drug, selegiline (Deprenyl). R-(-)-Methamphetamine is the urinary product from legitimate use of these medications. The second GC-MS test is to confirm illicit use of (S)-(+)-methamphetamine. In the procedure, the two methamphetamine isomers are changed to the chromatographically separable diastereomers by a chiral derivatizing agent, (S)-(-)-trifluoroacetylprolyl chloride (TPC). But the method has inherent limitations. Racemization of the reagent produces mixed diastereomers even from pure (S)-(+)-methamphetamine. Instead of using TPC, we utilized (R)-(-)-alpha-methoxy-alpha-(trifluoromethyl)phenylacetyl chloride (MTPA) to prepare the amides of diastereomers of methamphetamine. No racemization was observed with this reagent. The method was extended to resolve GC peaks of (R)-(-)- and (S)-(+)-isomers of amphetamine, 3,4-methylenedioxyamphetamine (MDA), N-methyl-MDA (MDMA), and N-ethyl-MDA (MDEA). Three ions from the drug and two ions from the deuterated internal standard were monitored to characterize and quantitate the drugs. For MDEA, only one ion was used. The quantitation was linear over 25 to 5000 ng/mL for MDEA and 25 to 10,000 ng/mL for all other drugs. Correlation coefficients were > 0.996. Precision calculated as the coefficient of variation at the calibrator concentration of 500 ng/mL was within +/- 11% for all drugs. The method was applied to test 43 urine specimens. In 91% of the methamphetamine-positive specimens, only the (S)-(+)-isomer was detected. In all MDMA-positive specimens, the concentrations of (R)-(-)-isomer were greater than the (S)-(+)-isomer indicating longer retention of (R)-(-)-isomer in the human body. The specimen concentrations (R + S) compared well with that of a non-chiral method that used 4-carboethoxyhexafluorobutyryl chloride as derivatizing agent. But the MTPA method has some advantage. It alone can replace the two GC-MS methods needed to confirm the presence of (S)-(+)-isomers of amphetamine and methamphetamine. PMID:15516295

Paul, Buddha D; Jemionek, John; Lesser, David; Jacobs, Aaron; Searles, Douglas A

2004-09-01

75

(4-(Bis(4-Fluorophenyl)Methyl)Piperazin-1-yl)(Cyclohexyl)Methanone Hydrochloride (LDK1229): A New Cannabinoid CB1 Receptor Inverse Agonist from the Class of Benzhydryl Piperazine Analogs.  

PubMed

Some inverse agonists of cannabinoid receptor type 1 (CB1) have been demonstrated to be anorectic antiobesity drug candidates. However, the first generation of CB1 inverse agonists, represented by rimonabant (SR141716A), otenabant, and taranabant, are centrally active, with a high level of psychiatric side effects. Hence, the discovery of CB1 inverse agonists with a chemical scaffold distinct from these holds promise for developing peripherally active CB1 inverse agonists with fewer side effects. We generated a new CB1 inverse agonist, (4-(bis(4-fluorophenyl)methyl)piperazin-1-yl)(cyclohexyl)methanone hydrochloride (LDK1229), from the class of benzhydryl piperazine analogs. This compound binds to CB1 more selectively than cannabinoid receptor type 2, with a Ki value of 220 nM. Comparable CB1 binding was also observed by analogs 1-[bis(4-fluorophenyl)methyl]-4-cinnamylpiperazine dihydrochloride (LDK1203) and 1-[bis(4-fluorophenyl)methyl]-4-tosylpiperazine hydrochloride (LDK1222), which differed by the substitution on the piperazine ring where the piperazine of LDK1203 and LDK1222 are substituted by an alkyl group and a tosyl group, respectively. LDK1229 exhibits efficacy comparable with SR141716A in antagonizing the basal G protein coupling activity of CB1, as indicated by a reduction in guanosine 5'-O-(3-thio)triphosphate binding. Consistent with inverse agonist behavior, increased cell surface localization of CB1 upon treatment with LDK1229 was also observed. Although docking and mutational analysis showed that LDK1229 forms similar interactions with the receptor as SR141716A does, the benzhydryl piperazine scaffold is structurally distinct from the first-generation CB1 inverse agonists. It offers new opportunities for developing novel CB1 inverse agonists through the optimization of molecular properties, such as the polar surface area and hydrophilicity, to reduce the central activity observed with SR141716A. PMID:25411367

Mahmoud, Mariam M; Olszewska, Teresa; Liu, Hui; Shore, Derek M; Hurst, Dow P; Reggio, Patricia H; Lu, Dai; Kendall, Debra A

2015-02-01

76

Solubility of carbon dioxide in aqueous mixtures of alkanolamines  

SciTech Connect

The solubility of CO[sub 2] in water + N-methyldiethanolamine + monoethanolamine (MDEA + MEA) and water + N-methyldiethanolamine + diethanolamine (MDEA + DEA) are reported at two compositions of 3.4 M MDEA + 0.8 M MEA or DEA and 2.1 M MDEA + 2.1 M MEA or DEA at temperatures from 70 to 180 C and CO[sub 2] partial pressures from 100 to 3,850 kPa. The solubility of CO[sub 2] in the blends decreased with an increase in temperature but increased with an increase in CO[sub 2] partial pressure. At low partial pressures of CO[sub 2] and the same total amine concentration, the equilibrium CO[sub 2] loadings were in the order MDEA + MEA > MDEA + DEA > MDEA. However, at high CO[sub 2] partial pressures, the equilibrium CO[sub 2] loadings in the MDEA solutions were higher than those of the MDEA + MEA and MDEA + DEA blends of equal molar strengths due to the stoichiometric loading limitations of MEA and DEA. The nonadditivity of the equilibrium loadings for single amine systems highlights the need for independent measurements on amine blends.

Dawodu, O.F.; Meisen, A. (Univ. of British Columbia, Vancouver, British Columbia (Canada). Dept. of Chemical Engineering)

1994-07-01

77

Design, synthesis, pharmacological evaluation and computational studies of 1-(biphenyl-4-yl)-2-[4-(substituted phenyl)-piperazin-1-yl]ethanones as potential antipsychotics.  

PubMed

This article describes the design of biphenyl moiety linked with aryl piperazine and syntheses of fourteen 1-(biphenyl-4-yl)-2-[4-(substituted phenyl)-piperazin-1-yl]ethanone derivatives along with their pharmacological evaluation for antipsychotic activity and computational studies including quantitative structure activity relationship (QSAR) and descriptor based similarity study. All compounds were found to exhibit considerable anti-dopaminergic and anti-serotonergic activity in behavioural models. Among all derivatives, compound 1-(biphenyl-4-yl)-2-[4-(2-methoxyphenyl)-piperazin-1-yl]ethanone (3c) and 1-(biphenyl-4-yl)-2-[4-(2,3-dichlorophenyl)-piperazin-1-yl]ethanone (3k) showed impressive antipsychotic profile with lower potency for catalepsy induction. These results were found to be sturdily matching with docking study in designing of compounds with homology model of human dopamine D2 receptor. Also the QSAR study strongly supports the obtained results. PMID:24486417

Bhosale, Sharad H; Kanhed, Ashish M; Dash, Radha Charan; Suryawanshi, Mugdha R; Mahadik, K R

2014-03-01

78

trans-Bis[2-(piperazin-1-yl)­ethan­amine]­bis­(saccharinato)cobalt(II)  

PubMed Central

In the centrosymmetric title complex, [Co(C7H4NO3S)2(C6H15N3)2], the CoII ion is coordinated by two saccharinate (sac) anions and two neutral 2-piperazin-1-ylethanamine (ppzea) ligands, showing a distorted octa­hedral coordination. Sac is O-bonded via the carbonyl group, while ppzea acts as an N,N?-bidentate chelating ligand. The mol­ecules are connected by N—H?N and N—H?O hydrogen bonds, forming a linear chain running parallel to the crystallographic a axis. The compound is isostructural with the reported Ni, Zn, and Cd analogues. PMID:21200630

Yilmaz, Veysel T.; Guney, Serkan; Kazak, Canan

2008-01-01

79

Solubility of carbon dioxide in an aqueous blend of diethanolamine and piperazine  

SciTech Connect

The solubility of CO{sub 2} in aqueous blends of diethanolamine (DEA) and piperazine (PZ), from mixtures of CO{sub 2} and N{sub 2}, was measured for temperatures and CO{sub 2} partial pressures ranging from (303.14 to 353.14) K and (10.133 to 20.265) kPa, respectively. Measurements were made by a saturation method using a laboratory scale bubble column. The results of CO{sub 2} solubility in liquid are expressed as {alpha}(CO{sub 2}) (mol CO{sub 2}/mol amine) for all experimental runs. A solubility model is developed to correlate and predict the solubility data of CO{sub 2} in aqueous blends of DEA and PZ. There is all acceptable degree of agreement between the experimental data of the present study and predictions of the solubility model with an average absolute deviation of less than 4.5%.

Mondal, M.K. [Banaras Hindu University, Varanasi (India). Dept. of Chemical Engineering and Technology

2009-09-15

80

Piperazine and piperidine triazole ureas as ultrapotent and highly selective inhibitors of monoacylglycerol lipase.  

PubMed

Monoacylglycerol lipase (MAGL) terminates the signaling function of the endocannabinoid, 2-arachidonoylglycerol (2-AG). During 2-AG hydrolysis, MAGL liberates arachidonic acid, feeding the principal substrate for the neuroinflammatory prostaglandins. In cancer cells, MAGL redirects lipid stores toward protumorigenic signaling lipids. Thus MAGL inhibitors may have great therapeutic potential. Although potent and increasingly selective MAGL inhibitors have been described, their number is still limited. Here, we have characterized piperazine and piperidine triazole ureas that combine the high potency attributable to the triazole leaving group together with the bulky aromatic benzodioxolyl moiety required for selectivity, culminating in compound JJKK-048 that potently (IC50 < 0.4 nM) inhibited human and rodent MAGL. JJKK-048 displayed low cross-reactivity with other endocannabinoid targets. Activity-based protein profiling of mouse brain and human melanoma cell proteomes suggested high specificity also among the metabolic serine hydrolases. PMID:23521796

Aaltonen, Niina; Savinainen, Juha R; Ribas, Casandra Riera; Rönkkö, Jani; Kuusisto, Anne; Korhonen, Jani; Navia-Paldanius, Dina; Häyrinen, Jukka; Takabe, Piia; Käsnänen, Heikki; Pantsar, Tatu; Laitinen, Tuomo; Lehtonen, Marko; Pasonen-Seppänen, Sanna; Poso, Antti; Nevalainen, Tapio; Laitinen, Jarmo T

2013-03-21

81

Vapor pressure measurements of bis(hydroxyethyl)piperazine and tris(hydroxyethyl)ethylenediamine  

SciTech Connect

Aqueous solutions of diethanolamine (DEA) are commonly used to remove acid gases (including hydrogen sulfide and carbon dioxide) from natural, refinery, and other industrial gas streams. Vapor pressures of bis(hydroxyethyl)piperazine (BHEP) and tris(hydroxyethyl)ethylenediamine (THEED) were measured in the temperature ranges of (412.65 to 507.15) and (372.55 to 472.35) K using the static and gas saturation techniques, respectively. The experimental data are well represented by the modified Antoine and the integrated Clausius-Clapeyron equations, and their coefficients are reported. The enthalpies of vaporization were found to be (62.76 {+-} 5.33) and (89.96 {+-} 3.91) kJ/mol for BHEP and THEED, respectively.

Abdi, M.A.; Meisen, A. [Univ. of British Columbia, Vancouver, British Columbia (Canada). Dept. of Chemical and Bio-Resource Engineering] [Univ. of British Columbia, Vancouver, British Columbia (Canada). Dept. of Chemical and Bio-Resource Engineering

1998-03-01

82

A novel R-stereoselective amidase from Pseudomonas sp. MCI3434 acting on piperazine-2-tert-butylcarboxamide.  

PubMed

A novel amidase acting on (R,S)-piperazine-2-tert-butylcarboxamide was purified from Pseudomonas sp. MCI3434 and characterized. The enzyme acted R-stereoselectively on (R,S)-piperazine-2-tert-butylcarboxamide to yield (R)-piperazine-2-carboxylic acid, and was tentatively named R-amidase. The N-terminal amino acid sequence of the enzyme showed high sequence identity with that deduced from a gene named PA3598 encoding a hypothetical hydrolase in Pseudomonas aeruginosa PAO1. The gene encoding R-amidase was cloned from the genomic DNA of Pseudomonas sp. MCI3434 and sequenced. Analysis of 1332 bp of the genomic DNA revealed the presence of one open reading frame (ramA) which encodes the R-amidase. This enzyme, RamA, is composed of 274 amino acid residues (molecular mass, 30 128 Da), and the deduced amino acid sequence exhibits homology to a carbon-nitrogen hydrolase protein (PP3846) from Pseudomonas putida strain KT2440 (72.6% identity) and PA3598 protein from P. aeruginosa strain PAO1 (65.6% identity) and may be classified into a new subfamily in the carbon-nitrogen hydrolase family consisting of aliphatic amidase, beta-ureidopropionase, carbamylase, nitrilase, and so on. The amount of R-amidase in the supernatant of the sonicated cell-free extract of an Escherichia coli transformant overexpressing the ramA gene was about 30 000 times higher than that of Pseudomonas sp. MCI3434. The intact cells of the E. coli transformant could be used for the R-stereoselective hydrolysis of racemic piperazine-2-tert-butylcarboxamide. The recombinant enzyme was purified to electrophoretic homogeneity from cell-free extract of the E. coli transformant overexpressing the ramA gene. On gel-filtration chromatography, the enzyme appeared to be a monomer. It had maximal activity at 45 degrees C and pH 8.0, and was completely inactivated in the presence of p-chloromercuribenzoate, N-ethylmaleimide, Mn2+, Co2+, Ni2+, Cu2+, Zn2+, Ag+, Cd2+, Hg2+, or Pb2+. RamA had hydrolyzing activity toward the carboxamide compounds, in which amino or imino group is connected to beta- or gamma-carbon, such as beta-alaninamide, (R)-piperazine-2-carboxamide (R)-piperidine-3-carboxamide, D-glutaminamide and (R)-piperazine-2-tert-butylcarboxamide. The enzyme, however, did not act on the other amide substrates for the aliphatic amidase despite its sequence similarity to RamA. PMID:15066183

Komeda, Hidenobu; Harada, Hiroyuki; Washika, Shingo; Sakamoto, Takeshi; Ueda, Makoto; Asano, Yasuhisa

2004-04-01

83

Acid gas treating by aqueous alkanolamines. Annual report, July-December 1992  

SciTech Connect

The objective of the work is to investigate the simultaneous absorption or desorption of CO2 and H2S into and from a mixed aqueous amine solvent consisting of methyldiethanolamine (MDEA) and diethanolamine (DEA). In work completed thus far models have been developed for single gas (either H2S or CO2) absorption into a single amine solution (MDEA or DEA). Density and viscosity measurements have been made for aqueous MDEA, DEA and MDEA/DEA mixtures over the temperature range 20 to 100 C and for concentrations up to 50 weight %.

Sandall, O.C.; Rinker, E.B.; Tamimi, A.; Davis, R.A.; Oelschlager, D.W.

1992-12-01

84

Acid gas treating by aqueous alkanolamines. Annual report, January-December 1993  

SciTech Connect

The objective of the work is to investigate the simultaneous absorption or desorption of CO2 and H2S into and from a mixed aqueous amine solvent consisting of methyldiethanolamine (MDEA) and diethanolamine (DEA). In work completed thus far, density, viscosity, gas diffusivity, gas solubility, surface tension, and amine solution vapor pressure have been measured for aqueous MDEA, DEA, and MDEA/DEA mixtures over the temperature range 20 to 100 deg. C and for concentrations up to 50 weight %. A mathematical model, based on the penetration theory, for the simultaneous absorption (desorption) of CO2 and H2S into (from) aqueous solutions of MDEA and DEA has been developed.

Sandall, O.C.; Rinker, E.B.; Ashour, S.

1993-12-01

85

1-(4-Chloro­phen­yl)piperazine-1,4-diium tetra­chlorido­zincate(II) monohydrate  

PubMed Central

In the crystal structure of the title compound, (C10H15ClN2)[ZnCl4]·H2O, the Zn atom is coordinated by four Cl atoms in a tetrahedral geometry. The water mol­ecules and the 1-(4-chloro­phen­yl)piperazine-1,4-diium cations inter­act with the [ZnCl4]2? anions through O—H?Cl, N—H?Cl, N—H?O and C—H?Cl hydrogen bonds (five simple and one bifurcated). Inter­molecular ?–? stacking inter­actions are present between adjacent aromatic rings of 1-(4-chloro­phenyl)­piperazine-1,4-diium cations (the centroid–centroid distance is 3.453?Å). PMID:21202751

Ben Gharbia, Imen; Kefi, Riadh; El Glaoui, Meher; Jeanneau, Erwann; Ben Nasr, Cherif

2008-01-01

86

1-(4-Chloro-phen-yl)piperazine-1,4-diium tetra-chlorido-zincate(II) monohydrate.  

PubMed

In the crystal structure of the title compound, (C(10)H(15)ClN(2))[ZnCl(4)]·H(2)O, the Zn atom is coordinated by four Cl atoms in a tetrahedral geometry. The water mol-ecules and the 1-(4-chloro-phen-yl)piperazine-1,4-diium cations inter-act with the [ZnCl(4)](2-) anions through O-H?Cl, N-H?Cl, N-H?O and C-H?Cl hydrogen bonds (five simple and one bifurcated). Inter-molecular ?-? stacking inter-actions are present between adjacent aromatic rings of 1-(4-chloro-phenyl)-piperazine-1,4-diium cations (the centroid-centroid distance is 3.453?Å). PMID:21202751

Ben Gharbia, Imen; Kefi, Riadh; El Glaoui, Meher; Jeanneau, Erwann; Ben Nasr, Cherif

2008-01-01

87

Synthesis and Evaluation of Anti-acetylcholinesterase Activity of Some Benzothiazole Based New Piperazine-dithiocarbamate Derivatives.  

PubMed

In this present study some benzothiazole derivatives bearing piperazine and thiocarbamate moieties were synthesized and their potential anticholinesterase properties were investigated. A set of 30 new compounds of 2-[(6-substituted benzothiazol-2-yl)amino]-2-oxoethyl 4-substituted piperazine-1-carbodithioate derivatives were synthesized by reacting 2-chloro-N-(6-substituted benzothiazole-2-yl)acetamide derivatives derivatives and sodium salts of appropriate N,N-disubstituted dithiocarbamic acids in acetone. The structures of the obtained compounds were elucidated using FT-IR, (1)H-NMR and MS spectral data and elemental analyses result. Each derivative was evaluated for its ability to inhibit acetylcholinesterase (AChE) using a modificated Ellman's spectrophotometric method. Some of the compounds can be identified as anticholinesterase agents due to their inhibitory effect when compared with Donepezil. Compounds with dimethylamino ethyl or dimethylamino propyl substituents were defined as the anticholinesterase active compounds. PMID:24918348

Mohsen, U A; Kaplancikli, Z A; Ozkay, Y; Yurtta?, L

2014-06-11

88

Synthesis and crystal structure of some new cadmium (II) macrocyclic Schiff-base complexes containing piperazine moiety  

Microsoft Academic Search

The metal templated Cd(II) cyclocondensation of 2,6-diacetylpiridine or 2,6-pyridinedicarbaldehyde and two different amines containing piperazine moieties have been investigated. The resulting ligands, L1 and L2 are 16- and L3 and L4 17-membered pentaaza macrocycles. The complexes have been characterized by a variety of methods including IR, 1H, 13C NMR, DEPT, COSY(H,H), HMQC(H,C), FAB spectrometry and conductivimetry measurements. The crystal structures

Hassan Keypour; Majid Rezaeivala; Laura Valencia; Sadegh Salehzadeh; Paulo Pe´rez-Lourido; Hamid Reza Khavasi

2009-01-01

89

(Z)-1-Di­phenyl­methyl-4-(3-phenyl­prop-2-en­yl)piperazine  

PubMed Central

In the title compound, C26H28N2, the piperazine group adopts a chair conformation with the exocyclic N—C bonds in equatorial orientations. The dihedral angle between the geminal benzene rings is 80.46?(12)° and the C=C—C—N torsion angle is 145.9?(2)°. In the crystal, weak C—H?? inter­actions link the mol­ecules into [100] chains. PMID:24860379

Shivaprakash, S.; Chandrasekara Reddy, G.; Jasinski, Jerry P.

2014-01-01

90

Kinetics of removal of carbon dioxide by aqueous solutions of N,N-diethylethanolamine and piperazine.  

PubMed

N,N-Diethylethanolamine (DEEA) is a very promising absorbent for CO(2) removal from gaseous streams, as it can be prepared from renewable resources. Aqueous mixtures of DEEA and piperazine (PZ) are attractive for the enhancement of CO(2) capture, due to the high CO(2) loading capacity of DEEA and high reactivity of PZ. In the present work, for the first time, the equilibrium and kinetic characteristics of the CO(2) reaction with such mixtures were considered. Kinetic data were obtained experimentally, by using a stirred cell reactor. These data were interpreted using a homogeneous activation mechanism, by which the investigated reaction was considered as a reaction between CO(2) and DEEA in parallel with the reaction of CO(2) with PZ. It is found that, in the studied range of temperatures, 298-308 K, and overall amine concentrations, 2.1-2.5 kmol/m(3), this reaction system belongs to the fast pseudo-first-order reaction regime systems. The second-order rate constant for the CO0 reaction with PZ was determined from the absorption rate measurements in the activated DEEA solutions, and its value at 303 K was found to be 24,450 m(3)/(kmol s). PMID:20151656

Konduru, Prashanti B; Vaidya, Prakash D; Kenig, Eugeny Y

2010-03-15

91

In vitro antitumor activity evaluation of some 1,2,4-triazine derivatives bearing piperazine amide moiety against breast cancer cells.  

PubMed

A series of 1,2,4-triazine derivatives bearing piperazine amide moiety has been synthesized and investigated for their potential anticancer activities. 1-[4-(5,6-Bis(4-subtituted phenyl)-1,2,4-triazin-3-yl)piperazin-1-yl]-2-[4-(3-substituted phenyl)piperazin-1-yl]ethanone derivative (1-32) compounds were synthesized by a four step synthetic procedure. The activity studies were evaluated using XTT method, BrdU method and flow cytometric analysis on MCF-7 breast cancer cells and NIH/3T3 (mouse embryonic fibroblast cells) healthy cells. Compounds 5 with 3-chlorophenyl and compound 7 with 4-chlorophenyl substitutions were found to be promising antiproliferative agents comparing with an effective anticancer drug, cisplatin. PMID:25438754

Yurtta?, Leyla; Demirayak, Seref; Ilg?n, Sinem; Atl?, Özlem

2014-11-15

92

Effect of the Piperazine Unit and Metal-Binding Site Position on the Solubility and Anti-Proliferative Activity of Ruthenium(II)- and Osmium(II)- Arene Complexes of Isomeric Indolo[3,2-c]quinoline—Piperazine Hybrids  

PubMed Central

In this study, the indoloquinoline backbone and piperazine were combined to prepare indoloquinoline–piperazine hybrids and their ruthenium- and osmium-arene complexes in an effort to generate novel antitumor agents with improved aqueous solubility. In addition, the position of the metal-binding unit was varied, and the effect of these structural alterations on the aqueous solubility and antiproliferative activity of their ruthenium- and osmium-arene complexes was studied. The indoloquinoline–piperazine hybrids L1–3 were prepared in situ and isolated as six ruthenium and osmium complexes [(?6-p-cymene)M(L1–3)Cl]Cl, where L1 = 6-(4-methylpiperazin-1-yl)-N-(pyridin-2-yl-methylene)-11H-indolo[3,2-c]quinolin-2-N-amine, M = Ru ([1a]Cl), Os ([1b]Cl), L2 = 6-(4-methylpiperazin-1-yl)-N-(pyridin-2-yl-methylene)-11H-indolo[3,2-c]quinolin-4-N-amine, M = Ru ([2a]Cl), Os ([2b]Cl), L3 = 6-(4-methylpiperazin-1-yl)-N-(pyridin-2-yl-methylene)-11H-indolo[3,2-c]quinolin-8-N-amine, M = Ru ([3a]Cl), Os ([3b]Cl). The compounds were characterized by elemental analysis, one- and two-dimensional NMR spectroscopy, ESI mass spectrometry, IR and UV–vis spectroscopy, and single-crystal X-ray diffraction. The antiproliferative activity of the isomeric ruthenium and osmium complexes [1a,b]Cl–[3a,b]Cl was examined in vitro and showed the importance of the position of the metal-binding site for their cytotoxicity. Those complexes containing the metal-binding site located at the position 4 of the indoloquinoline scaffold ([2a]Cl and [2b]Cl) demonstrated the most potent antiproliferative activity. The results provide important insight into the structure–activity relationships of ruthenium- and osmium-arene complexes with indoloquinoline–piperazine hybrid ligands. These studies can be further utilized for the design and development of more potent chemotherapeutic agents. PMID:24927493

2014-01-01

93

Piperazine and piperidine carboxamides and carbamates as inhibitors of fatty acid amide hydrolase (FAAH) and monoacylglycerol lipase (MAGL).  

PubMed

The key hydrolytic enzymes of the endocannabinoid system, fatty acid amide hydrolase (FAAH) and monoacylglycerol lipase (MAGL), are potential targets for various therapeutic applications. In this paper, we present more extensively the results of our previous work on piperazine and piperidine carboxamides and carbamates as FAAH and MAGL inhibitors. The best compounds of these series function as potent and selective MAGL/FAAH inhibitors or as dual FAAH/MAGL inhibitors at nanomolar concentrations. This study revealed that MAGL inhibitors should comprise leaving-groups with a conjugate acid pKa of 8-10, while diverse leaving groups are tolerated for FAAH inhibitors. PMID:25282655

Korhonen, Jani; Kuusisto, Anne; van Bruchem, John; Patel, Jayendra Z; Laitinen, Tuomo; Navia-Paldanius, Dina; Laitinen, Jarmo T; Savinainen, Juha R; Parkkari, Teija; Nevalainen, Tapio J

2014-12-01

94

Anxiogenic-like effect of infusing 1-(3-chlorophenyl) piperazine (mCPP) into the hippocampus  

Microsoft Academic Search

1-(3-Chlorophenyl) piperazine (mCPP) was previously shown to have an anxiogenic-like effect, i.e., it decreased total interaction\\u000a in a rat social interaction test. Evidence indicated mediation by activation of 5-HT1C receptors with an ED50 of approximately 500 µg\\/kg IP (Kennett et al. 1989). A comparable effect is now shown on infusing 4 µg of the drug ICV or\\u000a infusing 0.5 µg

P. Whitton; G. Curzon

1990-01-01

95

Selective removal of H2S from sour gases with microporous membranes. Part II. A liquid membrane of water-free tertiary amines  

Microsoft Academic Search

In the present study the application of a liquid membrane for selective removal of H2S from gases also containing CO2 was investigated. The liquid membrane was filled with pure methyl-di-ethanol-amine (MDEA). A theoretical model was developed to describe: (a) the chemical equilibrium between the dissolved gas and MDEA in the membrane and (b) the physical equilibrium between the solute (CO2

H. Kreulen; G. F. Versteeg; C. A. Smolders; Swaaij van W. P. M

1993-01-01

96

Dimethyl phenyl piperazine iodide (DMPP) induces glioma regression by inhibiting angiogenesis  

SciTech Connect

1,1-Dimethyl-4-phenyl piperazine iodide (DMPP) is a synthetic nicotinic acetylcholine receptor (nAChR) agonist that could reduce airway inflammation. In this study, we demonstrated that DMPP could dramatically inhibit glioma size maintained on the chick embryonic chorioallantoic membrane (CAM). We first performed MTT and BrdU incorporation experiments on U87 glioma cells in vitro to understand the mechanism involved. We established that DMPP did not significantly affect U87 cell proliferation and survival. We speculated that DMPP directly caused the tumor to regress by affecting the vasculature in and around the implanted tumor on our chick CAM model. Hence, we conducted detailed analysis of DMPP's inhibitory effects on angiogenesis. Three vasculogenesis and angiogenesis in vivo models were used in the study which included (1) early chick blood islands formation, (2) chick yolk-sac membrane (YSW) and (3) CAM models. The results revealed that DMPP directly suppressed all developmental stages involved in vasculogenesis and angiogenesis – possibly by acting through Ang-1 and HIF-2? signaling. In sum, our results show that DMPP could induce glioma regression grown on CAM by inhibiting vasculogenesis and angiogenesis. - Highlights: ?We demonstrated that DMPP inhibited the growth of glioma cells on chick CAM. ?DMPP did not significantly affect the proliferation and survival of U87 cells. ?We revealed that DMPP suppressed vasculogenesis and angiogenesis in chick embryo. ?Angiogenesis in chick CAM was inhibited by DMPP via most probably Ang-1 and HIF-2?. ?DMPP could be potentially developed as an anti-tumor drug in the future.

He, Yan-qing; Li, Yan; Wang, Xiao-yu [Key Laboratory for Regenerative Medicine of the Ministry of Education, Division of Histology and Embryology, Medical College, Jinan University, Guangzhou 510632 (China); He, Xiao-dong [Institute of Vascular Biological Sciences, Guangdong Pharmaceutical University, Guangzhou 510006 (China); Jun, Li [Guangdong Provincial Key Laboratory of Bioengineering Medicine, National Engineering Research Centre of Genetic Medicine, College of Life Science and Technology, Jinan University, Guangzhou 510632 (China); Chuai, Manli [Division of Cell and Developmental Biology, University of Dundee, Dundee, DD1 5EH (United Kingdom); Lee, Kenneth Ka Ho [Key Laboratory for Regenerative Medicine of the Ministry of Education, School of Biomedical Sciences, Chinese University of Hong Kong, Shatin (Hong Kong); Wang, Ju [Guangdong Provincial Key Laboratory of Bioengineering Medicine, National Engineering Research Centre of Genetic Medicine, College of Life Science and Technology, Jinan University, Guangzhou 510632 (China); Wang, Li-jing, E-mail: wanglijing62@163.com [Institute of Vascular Biological Sciences, Guangdong Pharmaceutical University, Guangzhou 510006 (China); Yang, Xuesong, E-mail: yang_xuesong@126.com [Key Laboratory for Regenerative Medicine of the Ministry of Education, Division of Histology and Embryology, Medical College, Jinan University, Guangzhou 510632 (China)

2014-01-15

97

Piperazine derivatives: Synthesis, inhibition of the Mycobacterium tuberculosis enoyl-acyl carrier protein reductase and SAR studies.  

PubMed

The Mycobacterium tuberculosis NADH-dependent enoyl-acyl carrier protein reductase (MtInhA) catalyzes hydride transfer to long-chain enoyl thioester substrates. MtInhA is a member of the mycobacterial type II dissociated fatty acid biosynthesis system, and is the bona fide target for isoniazid, the most prescribed drug for tuberculosis treatment. Here, a series of piperazine derivatives was synthesized and screened as MtInhA inhibitors, which resulted in the identification of compounds with IC50 values in the submicromolar range. A structure-activity relationship (SAR) evaluation indicated the importance of the chemical environment surrounding the carbonyl group for inhibition. In addition, the structure of one selected compound was supported by crystallographic studies, and experimental geometrical values were compared with semi-empirical quantum chemical calculations. Furthermore, the mode of inhibition and inhibitory dissociation constants were determined for the nine most active compounds. These findings suggest that these 9H-fluoren-9-yl-piperazine-containing compounds interact with MtInhA at the enoyl thioester (2-trans-dodecenoyl-CoA) substrate binding site. PMID:25461892

Rotta, Mariane; Pissinate, Kenia; Villela, Anne Drumond; Back, Davi Fernando; Timmers, Luis Fernando Saraiva Macedo; Bachega, José Fernando Ruggiero; de Souza, Osmar Norberto; Santos, Diógenes Santiago; Basso, Luiz Augusto; Machado, Pablo

2015-01-27

98

Piperazine and its carboxylic acid derivatives-functionalized mesoporous silica as nanocarriers for gemcitabine: Adsorption and release study.  

PubMed

Piperazine-functionalized SBA-15 nanorods were synthesized by post grafting method with methyldimethoxysilylpropylpiperazine (MDSP). The carboxylic acid derivatives of piperazine-functionalized SBA-15 nanorods were obtained using two different kinds of precursors (bromoacetic acid and succinic anhydride). The prepared materials were used as nanocarriers for the anticancer drug (gemcitabine). The obtained samples were characterized by SAXS, N2 adsorption-desorption, SEM, TEM, DLS, thermogravimetric analysis, FTIR, Raman and UV spectroscopies. The adsorption and release properties of all samples were investigated. In vitro study included cell toxicity. It was found that the surface functionalization increases the interaction between the carrier and gemcitabine and results in the loading enhancement of the drug. In addition, the adsorption of gemcitabine on the modified mesoporous matrix depends on the type of the introduced functional groups. The carboxylic acid-modified samples have higher loading content, due to the strong interaction with gemcitabine. The maximum content of deposited drug in the modified SBA-15 nanorods is close to 36wt.% that it is related to PC2-SBA-15 sample which obtained using succinic anhydride. The obtained results reveal that the surface functionalization leads toward a significant decrease of the drug release rate without any appreciable cytotoxicity. No significant differences are observed among the drug release rate from the modified samples. PMID:25686928

Bahrami, Zohreh; Badiei, Alireza; Atyabi, Fatemeh; Darabi, Hossein Reza; Mehravi, Bita

2015-04-01

99

Preparation, spectral and biological investigation of formaldehyde-based ligand containing piperazine moiety and its various polymer metal complexes.  

PubMed

A novel tetradentate salicylic acid-formaldehyde ligand containing piperazine moiety (SFP) was synthesized by condensation of salicylic acid, formaldehyde and piperazine in presence of base catalyst, which was subjected for the preparation of coordination polymers with metal ions like manganese(II), cobalt(II), copper(II), nickel(II) and zinc(II). All the synthesized polymeric compounds were characterized by elemental analysis, IR, (1)H NMR and electronic spectral studies. The thermal stability was determined by thermogravimetric analysis and thermal data revealed that all the polymer metal complexes show good thermal stability than their parent ligand. Electronic spectral data and magnetic moment values revealed that polymer metal complexes of Mn(II), Co(II) and Ni(II) show an octahedral geometry while Cu(II) and Zn(II) show distorted octahedral and tetrahedral geometry respectively. The antimicrobial screening of the ligand and coordination polymers was done by using Agar well diffusion method against various bacteria and fungi. It was evident from the data that antibacterial and antifungal activity increased on chelation and all the polymer metal complexes show excellent antimicrobial activity than their parent ligand. PMID:21757398

Khan, Shamim Ahmad; Nishat, Nahid; Parveen, Shadma; Rasool, Raza

2011-10-15

100

Heat of Dissolution Measurements for CO2 in Mixed Alkanolamine Solvents  

SciTech Connect

The main objective of this project is to measure heat of dissolution of CO{sub 2} in carefully selected mixed alkanolamine solvent systems, and provide such directly measured data that might be used for efficient design of CO{sub 2} capture processes, or for better understanding of thermodynamics of CO{sub 2}- alkanolamine systems. Carbon dioxide is one of the major greenhouse gases, and the need for stabilization of its composition in earth's atmosphere is vital for the future of mankind. Although technologies are available for capture and storage of CO{sub 2}, these technologies are far too expensive for economical commercialization. Reduction of cost would require research for refinement of the technology. For more economical CO{sub 2} capture and regeneration, there is a need for development of more efficient solvent systems. In this project we will extend the thermodynamic database by measuring heat of solution data of CO{sub 2} in mixed solvents made of MEA (monoethanolamine), MDEA (methyldiethanolamine), piperazine, and water. Mixed solvents of different compositions will be selected and in each case data will be measured at temperatures 40 and 80C and various partial pressures of CO{sub 2}. At the end of the project, observations, conclusions, and recommendations will be derived for the choice of mixed solvents for efficient CO{sub 2} capture with potential for commercialization.

Vinayak N. Kabadi

2007-03-31

101

Heat of Dissolution Measurements for CO2 in Mixed Alkanolamine Solvents  

SciTech Connect

The main objective of this project is to measure heat of dissolution of CO{sub 2} in carefully selected mixed alkanolamine solvent systems, and provide such directly measured data that might be used for efficient design of CO{sub 2} capture processes, or for better understanding of thermodynamics of CO{sub 2}-alkanolamine systems. Carbon dioxide is one of the major greenhouse gases, and the need for stabilization of its composition in earth's atmosphere is vital for the future of mankind. Although technologies are available for capture and storage of CO{sub 2}, these technologies are far too expensive for economical commercialization. Reduction of cost would require research for refinement of the technology. For more economical CO{sub 2} capture and regeneration, there is a need for development of more efficient solvent systems. In this project we will extend the thermodynamic database by measuring heat of solution data of CO{sub 2} in mixed solvents made of MEA (monoethanolamine), MDEA (methyldiethanolamine), piperazine, and water. Mixed solvents of different compositions will be selected and in each case data will be measured at temperatures 40 and 80C and various partial pressures of CO{sub 2}. At the end of the project, observations, conclusions, and recommendations will be derived for the choice of mixed solvents for efficient CO{sub 2} capture with potential for commercialization.

Vinayak N. Kabadi

2006-09-30

102

Heat of Dissolution Measurements for CO2 in Mixed Alkanolamine Solvents  

SciTech Connect

The main objective of this project is to measure heat of dissolution of CO{sub 2} in carefully selected mixed alkanolamine solvent systems, and provide such directly measured data that might be used for efficient design of CO{sub 2} capture processes, or for better understanding of thermodynamics of CO{sub 2}-alkanolamine systems. Carbon dioxide is one of the major greenhouse gases, and the need for stabilization of its composition in earth's atmosphere is vital for the future of mankind. Although technologies are available for capture and storage of CO{sub 2}, these technologies are far too expensive for economical commercialization. Reduction of cost would require research for refinement of the technology. For more economical CO{sub 2} capture and regeneration, there is a need for development of more efficient solvent systems. In this project we will extend the thermodynamic database by measuring heat of solution data of CO{sub 2} in mixed solvents made of MEA (monoethanolamine), MDEA (methyldiethanolamine), piperazine, and water. Mixed solvents of different compositions will be selected and in each case data will be measured at temperatures 40 and 80C and various partial pressures of CO{sub 2}. At the end of the project, observations, conclusions, and recommendations will be derived for the choice of mixed solvents for efficient CO{sub 2} capture with potential for commercialization.

Vinayak N. Kabadi

2006-05-29

103

HEAT OF DISSOLUTION MEASUREMENTS FOR CO2 IN MIXED ALKANOLAMINE SOLVENTS  

SciTech Connect

The main objective of this project is to measure heat of dissolution of CO{sub 2} in carefully selected mixed alkanolamine solvent systems, and provide such directly measured data that might be used for efficient design of CO{sub 2} capture processes, or for better understanding of thermodynamics of CO{sub 2}-alkanolamine systems. Carbon dioxide is one of the major greenhouse gases, and the need for stabilization of its composition in earth's atmosphere is vital for the future of mankind. Although technologies are available for capture and storage of CO{sub 2}, these technologies are far too expensive for economical commercialization. Reduction of cost would require research for refinement of the technology. For more economical CO{sub 2} capture and regeneration, there is a need for development of more efficient solvent systems. In this project we will extend the thermodynamic database by measuring heat of solution data of CO{sub 2} in mixed solvents made of MEA (monoethanolamine), MDEA (methyldiethanolamine), piperazine, and water. Mixed solvents of different compositions will be selected and in each case data will be measured at temperatures 40 and 80 C and various partial pressures of CO{sub 2}. At the end of the project, observations, conclusions, and recommendations will be derived for the choice of mixed solvents for efficient CO{sub 2} capture with potential for commercialization.

Vinayak N. Kabadi

2004-11-15

104

Heat of Dissolution Measurements for CO2 in Mixed Alkanolamine Solvents  

SciTech Connect

The main objective of this project is to measure heat of dissolution of CO{sub 2} in carefully selected mixed alkanolamine solvent systems, and provide such directly measured data that might be used for efficient design of CO{sub 2} capture processes, or for better understanding of thermodynamics of CO{sub 2}- alkanolamine systems. Carbon dioxide is one of the major greenhouse gases, and the need for stabilization of its composition in earth's atmosphere is vital for the future of mankind. Although technologies are available for capture and storage of CO{sub 2}, these technologies are far too expensive for economical commercialization. Reduction of cost would require research for refinement of the technology. For more economical CO{sub 2} capture and regeneration, there is a need for development of more efficient solvent systems. In this project we will extend the thermodynamic database by measuring heat of solution data of CO{sub 2} in mixed solvents made of MEA (monoethanolamine), MDEA (methyldiethanolamine), piperazine, and water. Mixed solvents of different compositions will be selected and in each case data will be measured at temperatures 40 and 80C and various partial pressures of CO{sub 2}. At the end of the project, observations, conclusions, and recommendations will be derived for the choice of mixed solvents for efficient CO{sub 2} capture with potential for commercialization.

Vinayak N. Kabadi

2005-12-01

105

HEAT OF DISSOLUTION MEASUREMENTS FOR CO2 IN MIXED ALKANOLAMINE SOLVENTS  

SciTech Connect

The main objective of this project is to measure heat of dissolution of CO{sub 2} in carefully selected mixed alkanolamine solvent systems, and provide such directly measured data that might be used for efficient design of CO{sub 2} capture processes, or for better understanding of thermodynamics of CO{sub 2}-alkanolamine systems. Carbon dioxide is one of the major greenhouse gases, and the need for stabilization of its composition in earth's atmosphere is vital for the future of mankind. Although technologies are available for capture and storage of CO{sub 2}, these technologies are far too expensive for economical commercialization. Reduction of cost would require research for refinement of the technology. For more economical CO{sub 2} capture and regeneration, there is a need for development of more efficient solvent systems. In this project we will extend the thermodynamic database by measuring heat of solution data of CO{sub 2} in mixed solvents made of MEA (monoethanolamine), MDEA (methyldiethanolamine), piperazine, and water. Mixed solvents of different compositions will be selected and in each case data will be measured at temperatures 40 and 80 C and various partial pressures of CO{sub 2}. At the end of the project, observations, conclusions, and recommendations will be derived for the choice of mixed solvents for efficient CO{sub 2} capture with potential for commercialization.

Vinayak N. Kabadi

2004-04-27

106

HEAT OF DISSOLUTION MEASUREMENTS FOR CO2 IN MIXED ALKANOLAMINE SOLVENTS  

SciTech Connect

The main objective of this project is to measure heat of dissolution of CO{sub 2} in carefully selected mixed alkanolamine solvent systems, and provide such directly measured data that might be used for efficient design of CO{sub 2} capture processes, or for better understanding of thermodynamics of CO{sub 2}-alkanolamine systems. Carbon dioxide is one of the major greenhouse gases, and the need for stabilization of its composition in earth's atmosphere is vital for the future of mankind. Although technologies are available for capture and storage of CO{sub 2}, these technologies are far too expensive for economical commercialization. Reduction of cost would require research for refinement of the technology. For more economical CO{sub 2} capture and regeneration, there is a need for development of more efficient solvent systems. In this project we will extend the thermodynamic database by measuring heat of solution data of CO{sub 2} in mixed solvents made of MEA (monoethanolamine), MDEA (methyldiethanolamine), piperazine, and water. Mixed solvents of different compositions will be selected and in each case data will be measured at temperatures 40 and 80C and various partial pressures of CO{sub 2}. At the end of the project, observations, conclusions, and recommendations will be derived for the choice of mixed solvents for efficient CO{sub 2} capture with potential for commercialization.

Vinayak N. Kabadi

2005-05-23

107

Influence of silica nanospheres on the separation performance of thin film composite poly(piperazine-amide) nanofiltration membranes  

NASA Astrophysics Data System (ADS)

A novel thin film nanocomposite nanofiltration (TFNN) membrane was fabricated by introducing silica nanospheres (ca. 235 ± 11 nm) in the interfacial polymerization process of trimesoyl chloride (TMC) and piperazine (PIP) over polysulfone (PS) support for investigating the effect of silica nanofiller on the separation performance (i.e., permeability and salt rejection) of conventional thin film composite poly(piperazine-amide) nanofiltration (TFCN) membrane. The physicochemical characterization results show that all of the silica nanospheres are uniformly embedded on the surface of TFNN membrane. The introduction of silica nanospheres improves the hydrophilicity of the TFCN membrane and also causes its isoelectric point shift to a lower pH value. Moreover, the active poly(piperazine-amide) barrier layer of TFNN membrane (60.8 ± 2.3 nm) is thinner than that of the pristine TFCN membrane (72.1 ± 2.5 nm) as a control sample. The separation performance tests reveal that the addition of silica nanospheres can obviously elevate the salt rejection of the pristine TFCN membrane from 87.58 ± 0.15 to 94.81 ± 0.17% under 2000 ppm of MgSO4 solution and 0.5 MPa operating pressure, simultaneously accompanied by the increases of permeate flux from 19.36 ± 0.75 to 22.65 ± 0.68 L/m2 h. Additionally, compared with pristine TFCN membrane, the fabricated TFNN membrane has relatively low salt rejection (43.20 ± 0.27%) in 0.5 MPa operating pressure for 500 ppm of NaCl aqueous solution, which demonstrates that the introduction of silica nanospheres can dramatically promote the divalent-ionic separation selectivity. Furthermore, the experimental results suggest that the nanocomposite TFNN membrane possesses stable filtration performance in the softening process of MgSO4 aqueous solution. The separation performance improvement should be attributed to the optimizations of microstructures and surface features of active barrier layer of TFNN membrane, caused by the addition of silica nanospheres.

Li, Qiang; Wang, Yihua; Song, Jie; Guan, Yipeng; Yu, Hui; Pan, Xianhui; Wu, Feiyang; Zhang, Meng

2015-01-01

108

Acemetacin cocrystals and salts: structure solution from powder X-ray data and form selection of the piperazine salt.  

PubMed

Acemetacin (ACM) is a non-steroidal anti-inflammatory drug (NSAID), which causes reduced gastric damage compared with indomethacin. However, acemetacin has a tendency to form a less soluble hydrate in the aqueous medium. We noted difficulties in the preparation of cocrystals and salts of acemetacin by mechanochemical methods, because this drug tends to form a hydrate during any kind of solution-based processing. With the objective to discover a solid form of acemetacin that is stable in the aqueous medium, binary adducts were prepared by the melt method to avoid hydration. The coformers/salt formers reported are pyridine carboxamides [nicotinamide (NAM), isonicotinamide (INA), and picolinamide (PAM)], caprolactam (CPR), p-aminobenzoic acid (PABA), and piperazine (PPZ). The structures of an ACM-INA cocrystal and a binary adduct ACM-PABA were solved using single-crystal X-ray diffraction. Other ACM cocrystals, ACM-PAM and ACM-CPR, and the piperazine salt ACM-PPZ were solved from high-resolution powder X-ray diffraction data. The ACM-INA cocrystal is sustained by the acid?pyridine heterosynthon and N-H?O catemer hydrogen bonds involving the amide group. The acid?amide heterosynthon is present in the ACM-PAM cocrystal, while ACM-CPR contains carboxamide dimers of caprolactam along with acid-carbonyl (ACM) hydrogen bonds. The cocrystals ACM-INA, ACM-PAM and ACM-CPR are three-dimensional isostructural. The carboxyl?carboxyl synthon in ACM-PABA posed difficulty in assigning the position of the H atom, which may indicate proton disorder. In terms of stability, the salts were found to be relatively stable in pH 7 buffer medium over 24?h, but the cocrystals dissociated to give ACM hydrate during the same time period. The ACM-PPZ salt and ACM-nicotinamide cocrystal dissolve five times faster than the stable hydrate form, whereas the ACM-PABA adduct has 2.5 times faster dissolution rate. The pharmaceutically acceptable piperazine salt of acemetacin exhibits superior stability, faster dissolution rate and is able to overcome the hydration tendency of the reference drug. PMID:25075330

Sanphui, Palash; Bolla, Geetha; Nangia, Ashwini; Chernyshev, Vladimir

2014-03-01

109

Acemetacin cocrystals and salts: structure solution from powder X-ray data and form selection of the piperazine salt  

PubMed Central

Acemetacin (ACM) is a non-steroidal anti-inflammatory drug (NSAID), which causes reduced gastric damage compared with indomethacin. However, acemetacin has a tendency to form a less soluble hydrate in the aqueous medium. We noted difficulties in the preparation of cocrystals and salts of acemetacin by mechanochemical methods, because this drug tends to form a hydrate during any kind of solution-based processing. With the objective to discover a solid form of acemetacin that is stable in the aqueous medium, binary adducts were prepared by the melt method to avoid hydration. The coformers/salt formers reported are pyridine carboxamides [nicotinamide (NAM), isonicotinamide (INA), and picolinamide (PAM)], caprolactam (CPR), p-aminobenzoic acid (PABA), and piperazine (PPZ). The structures of an ACM–INA cocrystal and a binary adduct ACM–PABA were solved using single-crystal X-ray diffraction. Other ACM cocrystals, ACM–PAM and ACM–CPR, and the piperazine salt ACM–PPZ were solved from high-resolution powder X-ray diffraction data. The ACM–INA cocrystal is sustained by the acid?pyridine heterosynthon and N—H?O catemer hydrogen bonds involving the amide group. The acid?amide heterosynthon is present in the ACM–PAM cocrystal, while ACM–CPR contains carboxamide dimers of caprolactam along with acid–carbonyl (ACM) hydrogen bonds. The cocrystals ACM–INA, ACM–PAM and ACM–CPR are three-dimensional isostructural. The carboxyl?carboxyl synthon in ACM–PABA posed difficulty in assigning the position of the H atom, which may indicate proton disorder. In terms of stability, the salts were found to be relatively stable in pH 7 buffer medium over 24?h, but the cocrystals dissociated to give ACM hydrate during the same time period. The ACM–PPZ salt and ACM–nicotinamide cocrystal dissolve five times faster than the stable hydrate form, whereas the ACM–PABA adduct has 2.5 times faster dissolution rate. The pharmaceutically acceptable piperazine salt of acemetacin exhibits superior stability, faster dissolution rate and is able to overcome the hydration tendency of the reference drug. PMID:25075330

Sanphui, Palash; Bolla, Geetha; Nangia, Ashwini; Chernyshev, Vladimir

2014-01-01

110

Synthesis, spectral and antibacterial studies of binuclear titanium(IV) / zirconium(IV) complexes of piperazine dithiosemicarbazones.  

PubMed

The reactions of mono(cyclopentadienyl)titanium(IV) trichloride and bis(cyclopentadienyl)titanium(IV)/ zirconium(IV) dichloride with a new class of dithiosemicarbazone, derived by condensing piperazine dithiosemicarbazide with benzaldehyde (L(1)H(2)), 2-chlorobenzaldehyde (L(2)H(2)), 4-nitrobenzaldehyde (L(3)H(2)) or salicylaldehyde (L(4)H(4)) have been studied and different types of binuclear products, viz. [{CpTiCl(2)}(2)L], [{Cp(2)MCl}(2)L], ((L=L(1), L(2) or L(3)), [{CpTiCI}(2)L(4)] and [{Cp(2)M}(2)L(4)] (M=Yi or Zr), have been isolated. Tentative structures are proposed for these complexes based upon elemental analyses, electrical conductance, magnetic moment and spectral (electronic, IR, (1)H and (13)C NMR) data. Attempts have been made to establish a correlation between antibacterial activity and the structures of the products. PMID:18365041

Pandey, O P; Sengupta, S K; Mishra, M K; Tripathi, C M

2003-01-01

111

Acid gas treating by aqueous alkanolamines. Annual report, January-December 1994  

SciTech Connect

The objective of this work is to investigate the simulateneous absorption or desorption of CO2 and H2S into and from a mixed aqueous amine solvent consisting of methyldiethanolamine (MDEA) and diethanolamine (DEA). In work completed this year the authors have measured the density, viscosity and surface tension of pure MDEA and DEA over a range in temperatures. The diffusivity of N2O was measured in aqueous blends of MDEA and DEA at 50 wt% total amine for various ratios of DEA to MDEA over the temperature range 20 to 80 deg. C. A theoretically-based model has been developed for the correlation of the physical solubility of N2O in aqueous amine solutions. A penetration theory type model which was developed to describe acid gas absorption in aqueous amine solutions was used to carry out a sensitivity analysis for the various parameters affecting the rate of absorption of CO2 in MDEA solutions.

Sandall, O.C.; Rinker, E.B.; Ashour, S.

1994-12-01

112

Electrochemical synthesis based on the oxidation of 1-(4-(4-hydroxyphenyl)piperazin-1-yl)ethanone in the presence of nucleophiles.  

PubMed

Electrochemical syntheses of new arylthiobenzazoles were carried out by electrochemical oxidation of 1-(4-(4-hydroxyphenyl)piperazin-1-yl)ethanone in the presence of 2-mercaptobenzothiazole and 2-mercaptobenzoxazole. Our voltammetric data indicate that electrochemically generated p-quinone imine participates in a Michael addition reaction with 2-SH-benzazoles leading to the disubstituted 1-(4-(4-hydroxyphenyl)piperazin-1-yl)ethanone. Also, a plausible mechanism for the oxidation of 1-(4-(3,5-bis(benzo[d]thiazol-2-ylthio)-4-hydroxyphenyl) in the presence of p-toluenesulfinic acid is presented. 1-(4-(3,5-Bis(benzo[d]thiazol-2-ylthio)-4-hydroxyphenyl) was converted into 2-(benzo[d]thiazol-2-ylthio)-6-tosylcyclohexa-2,5-diene-1,4-dione through a Michael-type addition of p-toluenesulfinic acid to anodically generated p-quinone imine, replacing 2-mercaptobenzothiazole and followed by hydrolysis. PMID:23198901

Amani, Amene; Nematollahi, Davood

2012-12-21

113

Conformational analysis of piperazine and piperidine analogs of GBR 12909: stochastic approach to evaluating the effects of force fields and solvent  

Microsoft Academic Search

Analogs of the flexible dopamine reuptake inhibitor, GBR 12909 (1), may have potential utility in the treatment of cocaine abuse. As a first step in the 3D-QSAR modeling of the dopamine transporter\\u000a (DAT)\\/serotonin transporter (SERT) selectivity of these compounds, we carried out conformational analyses of two analogs of\\u000a 1: a piperazine (2) and a related piperidine (3). Ensembles of conformers

Deepangi Pandit; William Roosma; Milind Misra; Kathleen M. Gilbert; William J. Skawinski; Carol A. Venanzi

2011-01-01

114

ANALYTICAL METHOD FOR 1METHYL4-AMINO-PIPERAZINE IN AN ACTIVE PHARMACEUTICAL INGREDIENT USING CHEMICAL DERIVATIZATION AND HPLC-UV  

Microsoft Academic Search

A method to form a UV-active derivative of 1-methyl-4-amino-piperazine (AMP) was developed. The method was based on the reaction of AMP with benzaldehyde, forming a stable derivative, which was UV-active. The method was used to analyze samples of an active pharmaceutical ingredient (API) for trace amounts of AMP. The derivatization approach allowed detection of AMP at low levels, using readily

Jyoti Patel; Eric Loeser; Rudy Kircher; Hanumantha Rao Marrepalli; Steven Fazio; Donald Drinkwater; Patrick Drumm

2010-01-01

115

Piperazine Analogs of Naphthyridine-3-carboxamides and Indole-2-carboxamides: Novel 5-HT3 Receptor Antagonists with Antidepressant-Like Activity.  

PubMed

Series of piperazine analogs of naphthyridine-3-carboxamides and indole-2-carboxamides were designed using a ligand-based approach with consideration of the pharmacophoric requirements for 5-HT3 receptor antagonists. The title carboxamides were synthesized using appropriate synthetic routes. Initially, the 5-HT3 receptor antagonistic activity of all the compounds was determined on isolated guinea pig ileum tissue against the 5-HT3 agonist, 2-methyl-5-hydroxytryptamine, which was denoted in the form of pA2 values. The structure-activity relationship regarding the influence of the aromatic part and basic moiety as features in the 5-HT3 pharmacophore was derived. Among all the compounds screened, the piperazine derivatives of indole-2-carboxamide 13i and naphthyridine-3-carboxamide 8h exhibited prominent 5-HT3 receptor antagonism with pA2 values of 7.5 and 7.3, respectively. Subsequent investigation of the antidepressant activities of selected compounds in the mouse forced swim test (FST) led to the identification of the piperazine analogs of indole-2-carboxamide 13i and naphthyridine-3-carboxamide 8h as the most promising compounds. Both 13i and 8h demonstrated significant reduction in the duration of immobility as compared to the control. Importantly, none of the tested compounds affected the baseline locomotion of mice at the tested dose levels. PMID:25581677

Dhar, Arghya K; Mahesh, Radhakrishnan; Jindal, Ankur; Bhatt, Shvetank

2015-01-01

116

Selective gas treating produces better claus feeds  

SciTech Connect

Methyldiethanolamine (MDEA) systems with 20-25% by wt MDEA solutions in water are cheaper and more convenient than monoethanolamine (MEA) or diethanolamine (DEA) systems for selective H/sub 2/S removal from gas streams containing H/sub 2/S and CO/sub 2/, because the amine circulation rate will be much less for the MDEA system; apparently, the reaction between MDEA and H/sub 2/S is gas-film-diffusion-rate limited, and the reaction between MDEA and CO/sub 2/ is kinetically controlled. MDEA systems facilitate selective H/sub 2/S absorption by controlling residence time, which is done by limiting the number of contact trays and the amine circulation rate. At high pressures, MDEA systems can remove H/sub 2/S down to 0.25-0.50 g/100 std cu ft, with only 20-30% of the CO/sub 2/ being co-absorbed. The MDEA system at the Husky (Oil Co.) Clark Avenue Gas Plant in Santa Maria, Calif., uses selective amine regeneration technology licensed from Shell Development Co. to enrich Claus unit feed from approx. 23 mole Vertical Bar3< H/sub 2/S up to approx. 50 mole % H/sub 2/S, thus allowing 94% sulfur recovery in a once-through system. Two other MDEA systems for high-pressure gas treating are discussed.

Goar, B.G.

1980-01-01

117

Complexation, thermal and catalytic studies of N-substituted piperazine, morpholine and thiomorpholine with some metal ions  

NASA Astrophysics Data System (ADS)

Several Cu(II), Pt(II) and Ni(II) complexes of N-substituted, piperazine (NN donor), morpholine (NO donor) and thiomorpholine (NS donor) derivatives were synthesized and their thermal behavior and catalytic activity in epoxidation reaction of cis-diphenylethylene were studied using oxygen sources NaOCl. The coordination compounds of Cu(II), Pt(II) and Ni(II) having general formula [MLCl]Cl, [ML2l]Cl2 or [ML]Cl2 with tetra coordinated geometry around metal ions have been isolated as solid. All the ligands and complexes were identified by spectroscopic methods and elemental analysis, magnetic measurements, electrical conductance and thermal analysis. A square planer structures have been proposed for all complexes. The thermal stability of the complexes discussed in terms of ligands donor atoms, geometry and central metal ions. The complexes have a similar thermal behavior for the selected metal ions. The thermogravimetric analyses suggest high thermal stability for most complexes followed by thermal decomposition in different steps. The decomposition processes were observed as water elimination, chloride anion removal and degradation of the organic ligands. Catalytic ability of the complexes were examined and found that all the complexes can effectively catalyze the epoxidation of cis-stilbene with NaOCl.

Kacan, Mesut; Turkyilmaz, Murat; Karabulut, Ferhat; Altun, Ozlen; Baran, Yakup

2014-01-01

118

Piperazine-2,3-dicarboxylic acid Derivatives as Dual Antagonists of NMDA and GluK1-Containing Kainate Receptors  

PubMed Central

Competitive N-methyl-D-aspartate receptor (NMDAR) antagonists bind to the GluN2 subunit, of which there are four types (GluN2A-D). We report that some N1-substituted derivatives of cis-piperazine-2,3-dicarboxylic acid display improved relative affinity for GluN2C and GluN2D versus GluN2A and GluN2B. These derivatives also display subtype-selectivity among the more distantly related kainate receptor family. Compounds 18i and (?)-4 were the most potent kainate receptor antagonists and 18i was selective for GluK1 versus GluK2, GluK3 and AMPA receptors. Modeling studies revealed structural features required for activity at GluK1 subunits and suggested that S674 was vital for antagonist activity. Consistent with this hypothesis, replacing the equivalent residue in GluK3 (alanine) with a serine imparts 18i antagonist activity. Antagonists with dual GluN2D and GluK1 antagonist activity may have beneficial effects in various neurological disorders. Consistent with this idea, antagonist 18i (30 mg/Kg i.p.) showed antinociceptive effects in an animal model of mild nerve injury. PMID:22111545

Irvine, Mark W.; Costa, Blaise M.; Dlaboga, Daniel; Culley, Georgia; Hulse, Richard; Scholefield, Caroline L.; Atlason, Palmi; Fang, Guangyu; Eaves, Richard; Morley, Richard; Mayo-Martin, Maria B.; Amici, Mascia; Bortolotto, Zuner A.; Donaldson, Lucy; Collingridge, Graham L.; Molnár, Elek; Monaghan, Daniel T.; Jane, David E.

2011-01-01

119

Coordination frameworks constructed from bipyridyl piperazine and MCl2 (M = Co, Ni, Zn): structural characterization and optical properties.  

PubMed

Three metal-organic polymers, [CoCl2(bpfp)]n 1, {[NiCl2(bpfp)2](H2O)3}n 2 and [ZnCl2(bpfp)]n 3 (bpfp = N,N'-bis(3-pyridylformyl)piperazine), are formed by the self-assembly of the flexible bpfp with MCl2 (M = Co, Ni, Zn), respectively. X-Ray single-crystal structural analysis reveals that polymer 1 exhibits a novel grid network, in which the grid is composed of segments of bpfp and cobalt ions. Polymer 2 consists of 2D rhombohedral grids, the dimensions of the grid are 15.782 x 12.434 A2 and the diagonal-to-diagonal distances are 13.186 x 25.169 A2. In polymer 3, infinite wavelike chains are extended to 2D supramolecular arrays via C-H...Cl hydrogen bonds. The third-order nonlinear optical (NLO) behaviors of 1-3 and bpfp were investigated in dilute DMF solution by Z-scan measurement. The results show that 1, 2 and 3 exhibit good third-order NLO properties, which are quite different from bpfp that shows weak NLO behavior. This paper demonstrates that metal ions can strongly influence the crystal structures and third-order NLO properties of polymers. PMID:16437179

Xu, Hong; Song, Yinglin; Mi, Liwei; Hou, Hongwei; Tang, Mingsheng; Sang, Yali; Fan, Yaoting; Pan, Yan

2006-02-14

120

Investigation on the inclusion interaction of 4-sulfonatocalix[n]arenes with 1-(4-nitrophenyl)piperazine  

NASA Astrophysics Data System (ADS)

The inclusion behaviors of 4-Sulfonatocalix[n]arenes (SCXn) (n = 4, 6, 8) with 1-(4-nitrophenyl)piperazine (NPP) were investigated by UV spectroscopy and fluorescence spectroscopy at different pH values (pH = 3.05, 6.50, 8.40). The UV absorption and fluorescence intensity of NPP remarkably increased in presence of SCXn revealing formation of the inclusion complexes between NPP and SCXn. Moreover, the formation constants (K) of inclusion complexes were also determined by the non-linear fitting method, and the obtained data showed that the formation constants decreased gradually with the increasing of the pH value. When the pH value was 3.05, the formation constant of NPP with SCX8 reached a maximum of 1.7 × 107 L mol-1. The stoichiometric ratio was verified to be 1:1 by the continuous variation method. Meanwhile FT-IR and DSC analysis also indicated that NPP could form the inclusion complex with SCXn. In order to explore the inclusion mechanism of NPP with SCXn, 1H NMR and molecular modeling studies were carried out and experimental results showed that the part of benzene ring of NPP penetrated into the hydrophobic cavity of SCXn.

Zhang, Yongbin; Chao, Jianbin; Zhao, Shuhui; Xu, Penghao; Wang, Hongfang; Guo, Zhiqiang; Liu, Diansheng

2014-11-01

121

Investigation on the inclusion interaction of 4-sulfonatocalix[n]arenes with 1-(4-nitrophenyl)piperazine.  

PubMed

The inclusion behaviors of 4-Sulfonatocalix[n]arenes (SCXn) (n=4, 6, 8) with 1-(4-nitrophenyl)piperazine (NPP) were investigated by UV spectroscopy and fluorescence spectroscopy at different pH values (pH=3.05, 6.50, 8.40). The UV absorption and fluorescence intensity of NPP remarkably increased in presence of SCXn revealing formation of the inclusion complexes between NPP and SCXn. Moreover, the formation constants (K) of inclusion complexes were also determined by the non-linear fitting method, and the obtained data showed that the formation constants decreasedgradually with the increasing of the pH value. When the pH value was 3.05, the formation constant of NPP with SCX8 reached a maximum of 1.7×10(7) L mol(-1). The stoichiometric ratio was verified to be 1:1 by the continuous variation method. Meanwhile FT-IR and DSC analysis also indicated that NPP could form the inclusion complex with SCXn. In order to explore the inclusion mechanism of NPP with SCXn, 1H NMR and molecular modeling studies were carried out and experimental results showed that the part of benzene ring of NPP penetrated into the hydrophobic cavity of SCXn. PMID:24858345

Zhang, Yongbin; Chao, Jianbin; Zhao, Shuhui; Xu, Penghao; Wang, Hongfang; Guo, Zhiqiang; Liu, Diansheng

2014-11-11

122

N-Aryl Piperazine Metabotropic Glutamate Receptor 5 Positive Allosteric Modulators Possess Efficacy in Preclinical Models of NMDA Hypofunction and Cognitive Enhancement  

PubMed Central

Impaired transmission through glutamatergic circuits has been postulated to play a role in the underlying pathophysiology of schizophrenia. Furthermore, inhibition of the N-methyl-d-aspartate (NMDA) subtype of ionotropic glutamate receptors (NMDAR) induces a syndrome that recapitulates many of the symptoms observed in patients with schizophrenia. Selective activation of metabotropic glutamate receptor subtype 5 (mGlu5) may provide a novel therapeutic approach for treatment of symptoms associated with schizophrenia through facilitation of transmission through central glutamatergic circuits. Here, we describe the characterization of two novel N-aryl piperazine mGlu5 positive allosteric modulators (PAMs): 2-(4-(2-(benzyloxy)acetyl)piperazin-1-yl)benzonitrile (VU0364289) and 1-(4-(2,4-difluorophenyl)piperazin-1-yl)-2-((4-fluorobenzyl)oxy)ethanone (DPFE). VU0364289 and DPFE induced robust leftward shifts in the glutamate concentration-response curves for Ca2+ mobilization and extracellular signal-regulated kinases 1 and 2 phosphorylation. Both PAMs displayed micromolar affinity for the common mGlu5 allosteric binding site and high selectivity for mGlu5. VU0364289 and DPFE possessed suitable pharmacokinetic properties for dosing in vivo and produced robust dose-related effects in reversing amphetamine-induced hyperlocomotion, a preclinical model predictive of antipsychotic-like activity. In addition, DPFE enhanced acquisition of contextual fear conditioning in rats and reversed behavioral deficits in a mouse model of NMDAR hypofunction. In contrast, DPFE had no effect on reversing apomorphine-induced disruptions of prepulse inhibition of the acoustic startle reflex. These mGlu5 PAMs also increased monoamine levels in the prefrontal cortex, enhanced performance in a hippocampal-mediated memory task, and elicited changes in electroencephalogram dynamics commensurate with procognitive effects. Collectively, these data support and extend the role for the development of novel mGlu5 PAMs for the treatment of psychosis and cognitive deficits observed in individuals with schizophrenia. PMID:23965381

Gregory, K.J.; Herman, E.J.; Ramsey, A.J.; Hammond, A.S.; Byun, N.E.; Stauffer, S.R.; Manka, J.T.; Jadhav, S.; Bridges, T.M.; Weaver, C.D.; Niswender, C.M.; Steckler, T.; Drinkenburg, W.H.; Ahnaou, A.; Lavreysen, H.; Macdonald, G.J.; Bartolomé, J.M.; Mackie, C.; Hrupka, B.J.; Caron, M.G.; Daigle, T.L.; Lindsley, C.W.; Conn, P.J.

2013-01-01

123

N-aryl piperazine metabotropic glutamate receptor 5 positive allosteric modulators possess efficacy in preclinical models of NMDA hypofunction and cognitive enhancement.  

PubMed

Impaired transmission through glutamatergic circuits has been postulated to play a role in the underlying pathophysiology of schizophrenia. Furthermore, inhibition of the N-methyl-d-aspartate (NMDA) subtype of ionotropic glutamate receptors (NMDAR) induces a syndrome that recapitulates many of the symptoms observed in patients with schizophrenia. Selective activation of metabotropic glutamate receptor subtype 5 (mGlu5) may provide a novel therapeutic approach for treatment of symptoms associated with schizophrenia through facilitation of transmission through central glutamatergic circuits. Here, we describe the characterization of two novel N-aryl piperazine mGlu5 positive allosteric modulators (PAMs): 2-(4-(2-(benzyloxy)acetyl)piperazin-1-yl)benzonitrile (VU0364289) and 1-(4-(2,4-difluorophenyl)piperazin-1-yl)-2-((4-fluorobenzyl)oxy)ethanone (DPFE). VU0364289 and DPFE induced robust leftward shifts in the glutamate concentration-response curves for Ca(2+) mobilization and extracellular signal-regulated kinases 1 and 2 phosphorylation. Both PAMs displayed micromolar affinity for the common mGlu5 allosteric binding site and high selectivity for mGlu5. VU0364289 and DPFE possessed suitable pharmacokinetic properties for dosing in vivo and produced robust dose-related effects in reversing amphetamine-induced hyperlocomotion, a preclinical model predictive of antipsychotic-like activity. In addition, DPFE enhanced acquisition of contextual fear conditioning in rats and reversed behavioral deficits in a mouse model of NMDAR hypofunction. In contrast, DPFE had no effect on reversing apomorphine-induced disruptions of prepulse inhibition of the acoustic startle reflex. These mGlu5 PAMs also increased monoamine levels in the prefrontal cortex, enhanced performance in a hippocampal-mediated memory task, and elicited changes in electroencephalogram dynamics commensurate with procognitive effects. Collectively, these data support and extend the role for the development of novel mGlu5 PAMs for the treatment of psychosis and cognitive deficits observed in individuals with schizophrenia. PMID:23965381

Gregory, K J; Herman, E J; Ramsey, A J; Hammond, A S; Byun, N E; Stauffer, S R; Manka, J T; Jadhav, S; Bridges, T M; Weaver, C D; Niswender, C M; Steckler, T; Drinkenburg, W H; Ahnaou, A; Lavreysen, H; Macdonald, G J; Bartolomé, J M; Mackie, C; Hrupka, B J; Caron, M G; Daigle, T L; Lindsley, C W; Conn, P J; Jones, C K

2013-11-01

124

Synthesis of N-(6-(4-(Piperazin-1-yl)phenoxy)pyridin-3-yl)benzenesulfonamide Derivatives for the Treatment of Metabolic Syndrome  

PubMed Central

Metabolic syndrome is a widely prevalent multifactorial disorder associated with an increased risk of cardiovascular disease and type 2 diabetes mellitus. High plasma levels of insulin and glucose due to insulin resistance are a major component of the metabolic disorder. Thiazolidinediones (TZDs) are potent PPAR? ligand and used as insulin sensitizers in the treatment of type 2 diabetes mellitus. They are potent insulin-sensitizing agents but due to adverse effects like hepatotoxicity, a safer alternative of TZDs is highly demanded. Here we report synthesis of N-(6-(4-(piperazin-1-yl)phenoxy)pyridin-3-yl)benzenesulfonamide derivatives as an alternate remedy for insulin resistance. PMID:25374688

Bajare, Swapnil; Anthony, Jessy; Nair, Amrutha; Damre, Anagha; B-Rao, Chandrika; Sivaramakrishnan, H.; Wilankar, Chandan; Marita, Rosalind

2013-01-01

125

Investigation of the mode of binding of a novel series of N-benzyl-4-heteroaryl-1-(phenylsulfonyl)piperazine-2-carboxamides to the hepatitis C virus polymerase  

SciTech Connect

Structure based rationales for the activities of potent N-benzyl-4-heteroaryl-1-(phenylsulfonyl)piperazine-2-carboxamide inhibitors of the hepatitis C viral polymerase are described herein. These compounds bind to the hepatitis C virus non-structural protein 5B (NS5B), and co-crystal structures of select examples from this series with NS5B are reported. Comparison of co-crystal structures of a potent analog with both NS5B genotype 1a and genotype 1b provides a possible explanation for the genotype-selectivity observed with this compound class and suggests opportunities for the further optimization of the series.

Gentles, Robert G.; Sheriff, Steven; Beno, Brett R.; Wan, Changhong; Kish, Kevin; Ding, Min; Zheng, Xiaofan; Chupak, Louis; Poss, Michael A.; Witmer, Mark R.; Morin, Paul; Wang, Ying-Kai; Rigat, Karen; Lemm, Julie; Voss, Stacey; Liu, Mengping; Pelosi, Lenore; Roberts, Susan B.; Gao, Min; Kadow, John F. (BMS) [BMS

2013-11-20

126

Synthesis and anticancer activities of 4-(4-substituted piperazin)-5,6,7-trialkoxy quinazoline derivatives.  

PubMed

A series of 4-(4-substituted piperazin)-5,6,7-trialkoxy quinazoline was prepared by conventional heating methods. Among these compounds, the crystal structure of compound 10o (CCDC: 916922) was determined by X-ray crystallography. Bioassay results showed that most target compounds had certain inhibition activities against proliferation of tumor cells, and some compounds even had good broad-spectrum inhibition activities. The ethoxyl series of compounds possessed higher inhibition activities against tumor cells than the methoxyl series of compounds. Bioactivity tests showed that the IC50 values of compound 10s against PC3, MGC803, A375, and A549 cells were 1.8, 2.8, 1.3, and 2.9 ??, respectively, which were much higher than those of commercial gefitinib (7.2, 7.6, 7.2, and 9.8 ?M, respectively). Conversely, the IC50 values of compound 10s were very low against NH3T3, indicating only weak effect on normal cells as also proven by lactate dehydrogenase and acridine orange/ethidium bromide staining. Analyses of cell configuration and cell cycle revealed that compound 10s possibly caused cells to remain at G0/G1 phase by inhibiting cell proliferation for 24 h. Compound 10s also inhibited the phosphorylation of ERK1/2 and P38 with obvious concentration dependence. Thus, these compounds can inhibit the proliferation of A549 cells through the interruption of ERK1/2 and P38signaling pathways. PMID:24675177

Zhang, Ying; Huang, Yin-Jiu; Xiang, Hong-Mei; Wang, Pei-Yi; Hu, De-Yu; Xue, Wei; Song, Bao-An; Yang, Song

2014-05-01

127

Mechanism-based inactivation of human cytochrome P450 3A4 by two piperazine-containing compounds.  

PubMed

Human cytochrome P450 3A4 (CYP3A4) is responsible for the metabolism of more than half of pharmaceutic drugs, and inactivation of CYP3A4 can lead to adverse drug-drug interactions. The substituted imidazole compounds 5-fluoro-2-[4-[(2-phenyl-1H-imidazol-5-yl)methyl]-1-piperazinyl]pyrimidine (SCH 66712) and 1-[(2-ethyl-4-methyl-1H-imidazol-5-yl)methyl]-4-[4-(trifluoromethyl)-2-pyridinyl]piperazine (EMTPP) have been previously identified as mechanism-based inactivators (MBI) of CYP2D6. The present study shows that both SCH 66712 and EMTPP are also MBIs of CYP3A4. Inhibition of CYP3A4 by SCH 66712 and EMTPP was determined to be concentration, time, and NADPH dependent. In addition, inactivation of CYP3A4 by SCH 66712 was shown to be unaffected by the presence of electrophile scavengers. SCH 66712 displays type I binding to CYP3A4 with a spectral binding constant (Ks) of 42.9 ± 2.9 µM. The partition ratios for SCH 66712 and EMTPP were 11 and 94, respectively. Whole protein mass spectrum analysis revealed 1:1 binding stoichiometry of SCH 66712 and EMTPP to CYP3A4 and a mass increase consistent with adduction by the inactivators without addition of oxygen. Heme adduction was not apparent. Multiple mono-oxygenation products with each inactivator were observed; no other products were apparent. These are the first MBIs to be shown to be potent inactivators of both CYP2D6 and CYP3A4. PMID:25273356

Bolles, Amanda K; Fujiwara, Rina; Briggs, Erran D; Nomeir, Amin A; Furge, Laura Lowe

2014-12-01

128

Synthesis and characterization of Ni(II), Cu(II) and Zn(II) complexes with new macrocyclic Schiff base ligands containing piperazine moiety  

NASA Astrophysics Data System (ADS)

Two new macrocyclic Schiff base ligands L 1 and L 2 from [1 + 1] and [2 + 2] condensation reaction, respectively, have been obtained in a one-pot synthesis starting from 1,4-bis(2-formylphenyl)piperazine and 2,2-dimethyl-propylendiamine. Unfortunately, because of the low solubility of two products, we were unable to separate them effectively. Macrocyclic Schiff base complexes [NiL 1](ClO 4) 2, [CuL 1](ClO 4) 2 and [ZnL 1](ClO 4) 2 were prepared from the reaction of a mixture of L 1 and L 2 in the presence of nickel(II), copper(II) and zinc(II) metal ions, respectively. In all cases, only [1 + 1] condensation products were obtained and no metal complexes were isolated with the L 2 macrocycle. All of complexes have been characterized by elemental analysis, IR spectra, FAB-MS, conductivity measurements and in the case of Zn(II) complex by 1H and 13C NMR spectroscopy. Crystal structures of [NiL 1](ClO 4) 2 and [NiL 1'](ClO 4) 2 complexes have been also determined. The Ni(II) is coordinated to the ligand L 1 and L 1' by two nitrogen atoms of piperazine group and two nitrogen atoms of the imine groups, in a slightly distorted square-planar geometry.

Keypour, Hassan; Arzhangi, Parisa; Rahpeyma, Nasibeh; Rezaeivala, Majid; Elerman, Yalcin; Büyükgüngör, Orhan; Valencia, Laura; Khavasi, Hamid Reza

2010-08-01

129

Here today, gone tomorrow…and back again? A review of herbal marijuana alternatives (K2, Spice), synthetic cathinones (bath salts), kratom, Salvia divinorum, methoxetamine, and piperazines.  

PubMed

Despite their widespread Internet availability and use, many of the new drugs of abuse remain unfamiliar to health care providers. The herbal marijuana alternatives, like K2 or Spice, are a group of herbal blends that contain a mixture of plant matter in addition to chemical grade synthetic cannabinoids. The synthetic cathinones, commonly called "bath salts," have resulted in nationwide emergency department visits for severe agitation, sympathomimetic toxicity, and death. Kratom, a plant product derived from Mitragyna speciosa Korth, has opioid-like effects, and has been used for the treatment of chronic pain and amelioration of opioid-withdrawal symptoms. Salvia divinorum is a hallucinogen with unique pharmacology that has therapeutic potential but has been banned in many states due to concerns regarding its psychiatric effects. Methoxetamine has recently become available via the Internet and is marked as "legal ketamine." Moreover, the piperazine derivatives, a class of amphetamine-like compounds that includes BZP and TMFPP, are making a resurgence as "legal Ecstasy." These psychoactives are available via the Internet, frequently legal, and often perceived as safe by the public. Unfortunately, these drugs often have adverse effects, which range from minimal to life-threatening. Health care providers must be familiar with these important new classes of drugs. This paper discusses the background, pharmacology, clinical effects, detection, and management of synthetic cannabinoid, synthetic cathinone, methoxetamine, and piperazine exposures. PMID:22271566

Rosenbaum, Christopher D; Carreiro, Stephanie P; Babu, Kavita M

2012-03-01

130

Crystal structure of 1-(3-chloro-phen-yl)piperazin-1-ium picrate-picric acid (2/1).  

PubMed

The title salt {systematic name: bis-[1-(3-chloro-phen-yl)piperazinium 2,4,6-tri-nitro-phenolate]-picric acid (2/1)}, 2C10H14ClN2 (+)·2C6H5N3O7 (-)·C6H6N3O7, crystallized with two independent 1-(3-chloro-phen-yl)piperazinium cations, two picrate anions and a picric acid mol-ecule in the asymmetric unit. The six-membered piperazine ring in each cation adopts a slightly distorted chair conformation and contains a protonated N atom. In the picric acid mol-ecule, the mean planes of the nitro groups in the ortho-, meta-, and para-positions are twisted from the benzene ring by 31.5?(3), 7.7?(1), and 3.8?(2)°, respectively. In the anions, the dihedral angles between the benzene ring and the ortho-, meta-, and para-nitro groups are 36.7?(1), 5.0?(6), 4.8?(2)°, and 34.4?(9), 15.3?(8), 4.5?(1)°, respectively. The nitro group in one anion is disordered and was modeled with two sites for one O atom with an occupancy ratio of 0.627?(7):0.373?(7). In the crystal, the picric acid mol-ecule inter-acts with the picrate anion through a trifurcated O-H?O four-centre hydrogen bond involving an intra-molecular O-H?O hydrogen bond and a weak C-H?O inter-action. Weak inter-molecular C-H?O inter-actions are responsible for the formation of cation-anion-cation trimers resulting in a chain along [010]. In addition, weak C-H?Cl and weak ?-? inter-actions [centroid-centroid distances of 3.532?(3), 3.756?(4) and 3.705?(3)?Å] are observed and contribute to the stability of the crystal packing. PMID:25484834

Kavitha, Channappa N; Jasinski, Jerry P; Kaur, Manpreet; Anderson, Brian J; Yathirajan, H S

2014-11-01

131

Lanthanide N,N'-piperazine-bis(methylenephosphonates) (Ln=La, Ce, Nd) that display flexible frameworks, reversible hydration and cation exchange  

SciTech Connect

Hydrothermal syntheses of lanthanide bisphosphonate metal organic frameworks comprising the light lanthanides lanthanum, cerium and neodymium and N,N'-piperazine bis(methylenephosphonic acid) (H{sub 2}L(1) and its 2-methyl and 2,5-dimethyl derivatives (H{sub 2}L(2) and H{sub 2}L(3)) gives three new structure types. At elevated starting pH (ca. 5 and above) syntheses give 'type I' materials with all metals and acids of the study (MLnLxH{sub 2}O, M=Na, K, Cs; Ln=La, Ce, Nd; x{approx}4: KCeL(1).4H{sub 2}O, C2/c, a=23.5864(2) A, b=12.1186(2) A, c=5.6613(2) A, beta=93.040(2){sup o}). The framework of structure type I shows considerable flexibility as the ligand is changed, due mainly to rotation around the -N-CH{sub 2}- bond of the linker in response to steric considerations. Type I materials demonstrate cation exchange and dehydration and rehydration behaviour. Upon dehydration of KCeL.4H{sub 2}O, the space group changes to P2{sub 1}/n, a=21.8361(12) A, b=9.3519(4) A, c=5.5629(3) A, beta=96.560(4){sup o}, as a result of a change of the piperazine ring from chair to boat configuration. When syntheses are performed at lower pH, two other structure types crystallise. With the 'non-methyl' ligand 1, type II materials result (LnL(1)H{sub 2}L(1).4.5H{sub 2}O: Ln=La, P-1, a=5.7630(13) A, b=10.213(2) A, c=11.649(2) A, alpha=84.242(2){sup o}, beta=89.051(2){sup o}, gamma=82.876(2){sup o}) in which one half of the ligands coordinate via the piperazine nitrogen atoms. With the 2-methyl ligand, structure type III crystallises (LnHL(2).4H{sub 2}O: Ln=Nd, Ce, P2{sub 1}/c, a=5.7540(9) A, b=14.1259(18) A, c=21.156(5) A, beta=90.14(2){sup o}) due to unfavourable steric interactions of the methyl group in structure type II. - Graphical abstract: The lanthanides La, Ce and Nd give a family of metal organic frameworks based on N,N'-piperazinebismethylenephosphonate ligands: these display reversible dehydration, structural flexibility and cation exchange.

Mowat, John P.S.; Groves, John A.; Wharmby, Michael T.; Miller, Stuart R.; Li Yang; Lightfoot, Philip [School of Chemistry, University of St. Andrews, Purdie Building, North Haugh, St. Andrews, Fife KY16 9ST (United Kingdom); Wright, Paul A., E-mail: paw2@st-and.ac.u [School of Chemistry, University of St. Andrews, Purdie Building, North Haugh, St. Andrews, Fife KY16 9ST (United Kingdom)

2009-10-15

132

Solid-state variable-temperature NMR study of the phase separation of polybutadiene polyurethane zwitterionomers  

NASA Astrophysics Data System (ADS)

Polybutadiene polyurethane (PBDPU) zwitterionomers based on 4,4'-diphenylmethane diisocyanate (MDI), methyl-diethanolamine (MDEA), and hydroxy terminated polybutadiene are studied with variable-temperature (VT) wide-line 1H NMR. Spin—spin relaxation times ( T2) and spin—lattice relaxation times ( T1) are measured. It is found that phase separation of PBDPU does not change significantly upon ionization. The initial incorporation of ionization groups destroys the crystallinity of the hard segment while further ionization enhances physical crosslinks in the hard phase. The results are compared with a previous VT NMR study on polyether polyurethane zwitterionomers based on MDI, MDEA and 1000 Da molecular weight polytetramethylene oxide.

Yang, G.; Chen, Q.; Wang, Y.; Yang, C.; Wu, X.

1994-07-01

133

Amine-degradation products play no part in corrosion at gas-sweetening plants  

SciTech Connect

Gas-sweetening units using diethanolamine (DEA) and methyldiethanolamine (MDEA) are occasionally subject to corrosion. Discounting the basic degradation products of DEA as the cause, researchers (1) confirmed the presence of formic, oxalic, and acetic acids in used amine solutions, (2) defined oxygen's role in forming these carboxylic acids, and (3) demonstrated that the acid contents of different units are about the same order of magnitude for both DEA and MDEA. In most cases, oxygen can be easily excluded from gas-treating units, especially in storage tanks, thereby limiting the formation of acid products.

Blanc, C.; Grall, M.; Demarais, G.

1982-11-15

134

tert-Butyl 4-{[2-amino-4-(2-hy-droxy-phen-yl)pyrimidin-5-yl]meth-yl}piperazine-1-carboxyl-ate.  

PubMed

In the title compound, C20H27N5O3, the central piperazine ring adopts a chair conformation, with the N-bound carboxyl-ate and methyl-ene substituents occupying bis-ectional and equatorial orientations, respectively. A twist is evident between the aromatic rings [dihedral angle = 25.61?(9)°] but an intra-molecular O-H?N hydrogen bond persists between these. Supra-molecular tapes along [1-10] are formed in the crystal packing through N(amino)-H?O(hydrox-yl) and N(amino)-H?N(pyrimidin-yl) hydrogen bonds, and these are linked into layers in the ab plane by ?-? inter-actions [inter-centroid distance between pyrimidinyl rings = 3.5919?(9)?Å]. PMID:24098254

Gajera, Nilesh N; Patel, Mukesh C; Jotani, Mukesh M; Tiekink, Edward R T

2013-01-01

135

tert-Butyl 4-{[2-amino-4-(2-hy­droxy­phen­yl)pyrimidin-5-yl]meth­yl}piperazine-1-carboxyl­ate  

PubMed Central

In the title compound, C20H27N5O3, the central piperazine ring adopts a chair conformation, with the N-bound carboxyl­ate and methyl­ene substituents occupying bis­ectional and equatorial orientations, respectively. A twist is evident between the aromatic rings [dihedral angle = 25.61?(9)°] but an intra­molecular O—H?N hydrogen bond persists between these. Supra­molecular tapes along [1-10] are formed in the crystal packing through N(amino)—H?O(hydrox­yl) and N(amino)—H?N(pyrimidin­yl) hydrogen bonds, and these are linked into layers in the ab plane by ?–? inter­actions [inter-centroid distance between pyrimidinyl rings = 3.5919?(9)?Å]. PMID:24098254

Gajera, Nilesh N.; Patel, Mukesh C.; Jotani, Mukesh M.; Tiekink, Edward R. T.

2013-01-01

136

Piperidin-1-yl-phosphonic acid and (4-phosphono-piperazin-1-yl) phosphonic acid: A new class of iron corrosion inhibitors in sodium chloride 3% media  

NASA Astrophysics Data System (ADS)

The inhibiting effect of the piperidin-1-yl-phosphonic acid (PPA) and (4-phosphono-piperazin-1-yl) phosphonic acid (PPPA) on the behavior of iron in 3% NaCl media has been examined by electrochemical and gravimetric measurements. Potentiodynamic polarization studies clearly reveal the fact that the addition of increasing concentrations of phosphonic acids moves the corrosion potential towards negative values and reduces the corrosion rate. In uninhibited and inhibited solutions, the increasing of temperature reduces the inhibition efficiency. Changes in impedance parameters ( Rt and Cdl) are indicative of adsorption of PPA and PPPA on the metal surface leading to the formation of protective films. Gravimetric measurements reveal that the presence of PPA and PPPA increases the inhibition efficiency by decreasing the corrosion rate. The results obtained by corrosion weight loss tests reveal that adsorption of compounds tested on the ARMCO iron surface obeys to Langmuir adsorption isotherm.

Amar, H.; Benzakour, J.; Derja, A.; Villemin, D.; Moreau, B.; Braisaz, T.

2006-07-01

137

Novel 3-nitro-1H-1,2,4-triazole-based piperazines and 2-amino-1,3-benzothiazoles as antichagasic agents.  

PubMed

We have previously shown that 3-nitro-1H-1,2,4-triazole-based amines demonstrate significant trypanocidal activity, in particular against Trypanosoma cruzi, the causative parasite of Chagas disease. In the present work we further expanded our research by evaluating in vitro the trypanocidal activity of nitrotriazole-based piperazines and nitrotriazole-based 2-amino-1,3-benzothiazoles to establish additional SARs. All nitrotriazole-based derivatives were active or moderately active against T. cruzi; however two of them did not fulfill the selectivity criteria. Five derivatives were active or moderately active against Trypanosoma brucei rhodesiense while one derivative was moderately active against Leishmania donovani. Active compounds against T. cruzi demonstrated selectivity indexes (toxicity to host cells/toxicity to T. cruzi amastigotes) from 117 to 1725 and 12 of 13 compounds were up to 39-fold more potent than the reference compound benznidazole. Detailed SARs are discussed. PMID:24012457

Papadopoulou, Maria V; Bloomer, William D; Rosenzweig, Howard S; Kaiser, Marcel; Chatelain, Eric; Ioset, Jean-Robert

2013-11-01

138

Synthesis and evaluation of 4-substituted piperidines and piperazines as balanced affinity µ opioid receptor (MOR) agonist/? opioid receptor (DOR) antagonist ligands  

PubMed Central

In this report, we describe a series of 4-substituted piperidine and piperazine compounds based on tetrahydroquinoline 1, a compound that shows balanced, low nanomolar binding affinity for the mu opioid receptor (MOR) and the delta opioid receptor (DOR). We have shown that by changing the length and flexibility profile of the side chain in this position, binding affinity is improved at both receptors by a significant degree. Furthermore, several of the compounds described herein display good efficacy at MOR, while simultaneously displaying DOR antagonism. The MOR agonist/DOR antagonist has shown promise in the reduction of negative side effects displayed by selective MOR agonists, namely the development of dependence and tolerance. PMID:24365161

Bender, Aaron M.; Clark, Mary J.; Agius, Michael P.; Traynor, John R.; Mosberg, Henry I.

2014-01-01

139

4-(2-Meth­oxy­phen­yl)piperazin-1-ium 6-chloro-5-isopropyl-2,4-dioxopyrimidin-1-ide  

PubMed Central

In the cation of the title salt, C11H17N2O+·C7H8ClN2O2 ?, the piperazine ring adopts a distorted chair conformation and contains a positively charged N atom with quaternary character. Its mean plane makes a dihedral angle of 42.36?(8)° with the phenyl ring of its 2-meth­oxy­phenyl substituent. The 2,4-dioxopyrimidin-1-ide anion is generated by deprotonation of the N atom at the 1-position of the pyrimidine­dione ring. Intra­molecular C—H?O hydrogen bonds generate S(6) ring motifs in both the cation and the anion. In the crystal, N—H?O, N—H?N and C—H?O hydrogen bonds are also observed, resulting in a two-dimensional network parallel to the ab plane. The crystal stability is further consolidated by weak C—H?? inter­actions. PMID:24764966

Al-Omary, Fatmah A. M.; Ghabbour, Hazem A.; El-Emam, Ali A.; Chidan Kumar, C. S.; Fun, Hoong-Kun

2014-01-01

140

Novel 3-nitro-1H-1,2,4-triazole-based piperazines and 2-amino-1,3-benzothiazoles as antichagasic agents  

PubMed Central

We have previously shown that 3-nitro-1H-1,2,4-triazole-based amines demonstrate significant trypanocidal activity, in particular against T. cruzi, the causative parasite of Chagas disease. In the present work we further expanded our research by evaluating in vitro the trypanocidal activity of nitrotriazole-based piperazines and nitrotriazole-based 2-amino-1,3-benzothiazoles to establish additional SARs. All nitrotriazole-based derivatives were active or moderately active against T. cruzi; however two of them did not fulfill the selectivity criteria. Five derivatives were active or moderately active against T.b. rhodesiense while one derivative was moderately active against L. donovani. Active compounds against T. cruzi demonstrated selectivity indexes (toxicity to host cells/toxicity to T. cruzi amastigotes) from 117-1725 and 12 of 13 compounds were up to 39-fold more potent than the reference compound benznidazole. Detailed SARs are discussed. PMID:24012457

Papadopoulou, Maria V.; Bloomer, William D.; Rosenzweig, Howard S.; Kaiser, Marcel; Chatelain, Eric; Ioset, Jean-Robert

2013-01-01

141

Liquid chromatography tandem mass spectrometry determination of selected synthetic cathinones and two piperazines in oral fluid. Cross reactivity study with an on-site immunoassay device.  

PubMed

Since the past few years, several synthetic cathinones and piperazines have been introduced into the drug market to substitute illegal stimulant drugs such as amphetamine and derivatives or cocaine due to their unregulated situation. These emerging drugs are not usually included in routine toxicological analysis. We developed and validated a LC-MS/MS method for the determination of methedrone, methylone, mephedrone, 3,4-methylenedioxypyrovalerone (MDPV), fluoromethcathinone, fluoromethamphetamine, 1-(3-chlorophenyl)piperazine (mCPP) and 3-trifluoromethylphenylpiperazine (TFMPP) in oral fluid. Sample extraction was performed using Strata X cartridges. Chromatographic separation was achieved in 10min using an Atlantis(®) T3 column (100mm×2.1mm, 3?m), and formic acid 0.1% and acetonitrile as mobile phase. The method was satisfactorily validated, including selectivity, linearity (0.2-0.5 to 200ng/mL), limits of detection (0.025-0.1ng/mL) and quantification (0.2-0.5ng/mL), imprecision and accuracy in neat oral fluid (%CV=0.0-12.7% and 84.8-103.6% of target concentration, respectively) and in oral fluid mixed with Quantisal™ buffer (%CV=7.2-10.3% and 80.2-106.5% of target concentration, respectively), matrix effect in neat oral fluid (-11.6 to 399.7%) and in oral fluid with Quantisal™ buffer (-69.9 to 131.2%), extraction recovery (87.9-134.3%) and recovery from the Quantisal™ (79.6-107.7%), dilution integrity (75-99% of target concentration) and stability at different conditions (-14.8 to 30.8% loss). In addition, cross reactivity produced by the studied synthetic cathinones in oral fluid using the Dräger DrugTest 5000 was assessed. All the analytes produced a methamphetamine positive result at high concentrations (100 or 10?g/mL), and fluoromethamphetamine also at low concentration (0.075?g/mL). PMID:25482853

de Castro, Ana; Lendoiro, Elena; Fernández-Vega, Hadriana; Steinmeyer, Stefan; López-Rivadulla, Manuel; Cruz, Angelines

2014-12-29

142

Efficient Approach to Improving the Flame Retardancy of Poly(vinyl alcohol)/Clay Aerogels: Incorporating Piperazine-Modified Ammonium Polyphosphate.  

PubMed

Ammonium polyphosphates (APP) modified with piperazine (PA-APP) was used to improve the flame retardancy of poly(vinyl alcohol) (PVA)/montmorillonite (MMT) aerogels, which were prepared via an environmentally friendly freeze-drying method. The thermal stabilities of the samples were evaluated by thermogravimetric analysis (TG); the flammability behaviors of samples were investigated by limiting oxygen index (LOI), vertical burning test (UL-94) and cone calorimeter (CC) tests. TG test results showed that the 5% weight loss temperature (T5%) of PVA/MMT/PA-APP was 10 °C higher than that of PVA/MMT/APP. In combustion testing, all of PVA/MMT/PA-APP aerogels achieved V-0 ratings and have a higher LOI values than the unmodified PVA/MMT aerogel. Moreover, the aerogel with 1% PA-APP5, which means that the content of piperazine is 5% in PA-APP, decreased the cone calorimetry THR value to 5.71 MJ/m(2), and increased the char residue to 52%. The compressive modulus of PVA/MMT/PA-APP was increased by 93.4% compared with PVA/MMT/APP because of the increase in interfacial adhesion between matrix and PA-APP fillers. The densities of the PVA/MMT/PA-APP samples were slightly lower than those of the unmodified aerogels because of reduced shrinkage in the presence of PA-APP. All the tests results indicated that the incorporation of PA-APP not only improved the thermal stability and flame retardancy of aerogels but also maintained their mechanical properties. PMID:25588129

Wang, Yu-Tao; Liao, Shi-Fu; Shang, Ke; Chen, Ming-Jun; Huang, Jian-Qian; Wang, Yu-Zhong; Schiraldi, David A

2015-01-28

143

A liquid chromatography-electrospray ionization-tandem mass spectrometry study of ethanolamines in high salinity industrial wastewaters  

Microsoft Academic Search

The detection and quantitation of four ethanolamines, tris(2-hydroxyethyl)amine (triethanolamine, TEA), N,N-bis(2-hydroxyethyl)methylamine (methyldiethanolamine, MDEA), N-(2-aminoethyl)ethanolamine (AEA), and N,N-diethylethanolamine (DEA), were achieved in wastewaters from two aerobic activated sludge bioreactors located in an industrial wastewater treatment plant. The streams had salt concentrations of approximately 3% and 7% by weight in Reactor 1 and Reactor 2, respectively. The use of liquid chromatography-electrospray ionization-tandem

Pablo Campo; Makram T. Suidan; Yunzhou Chai; John Davis

2010-01-01

144

Spacer conformation in biologically active molecules. Part 2. Structure and conformation of 4-[2-(diphenylmethylamino)ethyl]-1-(2-methoxyphenyl) piperazine and its diphenylmethoxy analog—potential 5-HT 1A receptor ligands  

NASA Astrophysics Data System (ADS)

As a part of studies on biologically active molecule structures with aliphatic linking chain, the structures of 4-[2-diphenylmethylamino)ethyl]-1-(2-methoxyphenyl)piperazine dihydrochloride ( 1) and 4-[2-diphenylmethoxy)ethyl]-1-(2-methoxyphenyl)piperazine fumarate ( 2) have been reported. In both compounds, four atomic non-all-carbons linking chains (N)C-C-X-C are present. The conformation of that linking spacer depends on the nature of the X-atom. The preferred conformation for chain with X?NH has been found to be fully extended while for that with X?O—the bend one. It was confirmed by conformational calculations (strain energy distribution and random search) and crystallographic data, including statistics from CCDC.

Karolak-Wojciechowska, J.; Fruzi?ski, A.; Czylkowski, R.; Paluchowska, M. H.; Mokrosz, M. J.

2003-09-01

145

An azide-bridged copper(II) complex: poly[piperazine-1,4-dium [tetra-??-azido-?¹²N¹:N¹:N¹-hexa-??-azido-?¹²N¹:N¹-di-??-azido-??N¹:N³-pentacopper(II)] tetrahydrate].  

PubMed

A new Cu(II)-azide complex, {(C4H12N2)[Cu5(N3)12]·4H2O}n, has been synthesized by the reaction of piperazine, Cu(OAc)2·2H2O (OAc is acetate) and NaN3. In the structure, ?2-1,1- and ?3-1,1,1-azide anions bridge five Cu(II) cations to form a linear pentanuclear cluster unit, which is further linked by ?2-1,1- and ?2-1,3-azide anions to form a two-dimensional condensed [Cu5(N3)12]n layer. The diprotonated piperazine and the solvent water molecules are hydrogen bonded to the coordination layers to form a three-dimensional supramolecular network. PMID:25370112

Liu, Hou-Ting; Lu, Jing

2014-11-01

146

Synthesis and in vivo anticonvulsant activity of 2-methyl-2-[3-(5-piperazin-1-yl-[1,3,4]oxadiazol-2-yl)-phenyl]-propionitrile derivatives.  

PubMed

A series of new 2-methyl-2-[3-(5-piperazin-1-yl-[1,3,4]oxadiazol-2-yl)-phenyl]-propionitrile derivatives 8a-o, 9a-c, 10a-d, and 11a-d were synthesized to meet the structural requirements essential for anticonvulsant property. The structures of all the synthesized compounds were confirmed by means of (1)H NMR, (13)C NMR, and mass spectral studies. The purity of the novel compounds was confirmed by elemental analyses. All the compounds were screened for their anticonvulsant activity against maximal electroshock (MES) seizure method and their neurotoxic effects were determined by rotorod test. Compounds 8d, 8e, and 8f were found to be the most potent of this series. The same compounds showed no neurotoxicity at the maximum dose administered (100?mg/kg). The efforts were also made to establish the structure-activity relationships among the synthesized compounds. The pharmacophore model was used to validate the anticonvulsant activity of the synthesized molecules. PMID:24395602

Harish, Kikkeri P; Mohana, Kikkeri N; Mallesha, Lingappa; Veeresh, Bantal

2014-04-01

147

Design, synthesis, and biological evaluation of a novel series of bisintercalating DNA-binding piperazine-linked bisanthrapyrazole compounds as anticancer agents.  

PubMed

A series of bisintercalating DNA binding bisanthrapyrazole compounds containing piperazine linkers were designed by molecular modeling and docking techniques. Because the anthrapyrazoles are not quinones they are unable to be reductively activated like doxorubicin and other anthracyclines and thus they should not be cardiotoxic. The concentration dependent increase in DNA melting temperature was used to determine the strength of DNA binding and the bisintercalation potential of the compounds. Compounds with more than a three-carbon linker that could span four DNA base pairs achieved bisintercalation. All of the bisanthrapyrazoles inhibited human erythroleukemic K562 cell growth in the low to submicromolar concentration range. They also strongly inhibited the decatenation activity of topoisomerase II? and the relaxation activity of topoisomerase I. However, as measured by their ability to induce double strand breaks in plasmid DNA, the bisanthrapyrazole compounds did not act as topoisomerase II? poisons. In conclusion, a novel group of bisanthrapyrazole compounds were designed, synthesized, and biologically evaluated as potential anticancer agents. PMID:22041173

Zhang, Rui; Wu, Xing; Yalowich, Jack C; Hasinoff, Brian B

2011-12-01

148

Antioxidant, DNA binding and nuclease activities of heteroleptic copper(II) complexes derived from 2-((2-(piperazin-1-yl)ethylimino)methyl)-4-substituted phenols and diimines  

NASA Astrophysics Data System (ADS)

A series of heteroleptic copper(II) complexes of the type [CuL1-4(diimine)](ClO4)2 (1-8) [L1-4 = 2-((2-(piperazin-1-yl)ethylimino)methyl)-4-substituted phenols, and diimine = 2,2?-bipyridyl (bpy) or 1,10-phenanthroline (phen)], have been synthesized and characterized by spectroscopic methods. The IR spectra of complexes indicate the presence of uncoordinated perchlorate anions and the electronic spectra revealed the square pyramidal geometry with N4O coordination environment around copper(II) nuclei. Electrochemical studies of the mononuclear complexes evidenced one-electron irreversible reduction wave in the cathodic region. The EPR spectra of complexes with g|| (2.206-2.214) and A|| (154-172 × 10-4 cm-1) values support the square-based CuN3O coordination chromophore and the presence of unpaired electron localized in dx-y ground state. Antioxidant studies against DPPH revealed effective radical scavenging properties of the synthesized complexes. Binding studies suggest that the heteroleptic copper(II) complexes interact with calf thymus DNA (CT-DNA) through minor-groove and electrostatic interaction, and all the complexes display pronounced nuclease activity against supercoiled pBR322 DNA.

Ravichandran, J.; Gurumoorthy, P.; Imran Musthafa, M. A.; Kalilur Rahiman, A.

2014-12-01

149

Diffusion coefficients and heats of mixing in aqueous alkanolamines. Annual report, January-December 1992  

SciTech Connect

The objective of the work is to provide accurate data on diffusion coefficients and heats of absorption of acid gases in aqueous amine solutions to assist in the design of economical new amine treating systems and to improve the efficiency of existing plants. Specifically covered in the report are measurements of the mutual diffusion coefficient of methyldiethanolamine(MDEA) and diethanolamine in water. Measurements have been made at 25, 50 and 75C and at 0, 20, 35 and 50 wt% amine. Heats of absorption of CO2 into aqueous mixtures of MDEA have also been measured calorimetrically. Results are reported at temperatures of 120 and 260F and pressures of 500 and 1000 psia at total MDEA concentrations of 20, 35 and 50%.

Rowley, R.L.; Oscarson, J.L.

1993-01-01

150

Density and viscosity of some partially carbonated aqueous alkanolamine solutions and their blends  

SciTech Connect

Very little information is available concerning the effect of acid gas loading on the physical properties of amine-treating solutions flowing through the absorption and regeneration columns used in gas processing. The densities and viscosities of partially carbonated monoethanolamine (MEA), diethanolamine (DEA), and N-methyldiethanolamine (MDEA) solutions were measured at 298 K. With increasing carbon dioxide loadings, significant increases in both density and viscosity were observed. These results were combined with literature data to produce correlations for alkanolamine solution density and viscosity as a function of amine concentration, carbon dioxide loading, and temperature. The resulting single-amine correlations were used to predict the densities and viscosities of DEA + MDEA and MEA + MDEA blends. Predictions are compared with data measured for these blends.

Weiland, R.H.; Dingman, J.C.; Cronin, D.B.; Browning, G.J. [Optimized Gas Treating, Inc., Houston, TX (United States)] [Optimized Gas Treating, Inc., Houston, TX (United States)

1998-05-01

151

(3,3-Difluoro-pyrrolidin-1-yl)-[(2S,4S)-(4-(4-pyrimidin-2-yl-piperazin-1-yl)-pyrrolidin-2-yl]-methanone: A potent, selective, orally active dipeptidyl peptidase IV inhibitor  

SciTech Connect

A series of 4-substituted proline amides was synthesized and evaluated as inhibitors of dipeptidyl pepdidase IV for the treatment of type 2 diabetes. (3,3-Difluoro-pyrrolidin-1-yl)-[(2S,4S)-(4-(4-pyrimidin-2-yl-piperazin-1-yl)-pyrrolidin-2-yl]-methanone (5) emerged as a potent (IC{sub 50} = 13 nM) and selective compound, with high oral bioavailability in preclinical species and low plasma protein binding. Compound 5, PF-00734200, was selected for development as a potential new treatment for type 2 diabetes.

Ammirati, Mark J.; Andrews, Kim M.; Boyer, David D.; Brodeur, Anne M.; Danley, Dennis E.; Doran, Shawn D.; Hulin, Bernard; Liu, Shenping; McPherson, R. Kirk; Orena, Stephen J.; Parker, Janice C.; Polivkova, Jana; Qiu, Xiayang; Soglia, Carolyn B.; Treadway, Judith L.; VanVolkenburg, Maria A.; Wilder, Donald C.; Piotrowski, David W.; Pfizer

2010-10-01

152

Determination of the antihypertensive drug 1-[2-ethoxy-2-(3'-pyridyl)ethyl]-4-(2'-methoxyphenyl) piperazine (IP/66) in rat and human plasma by high-performance liquid chromatography and isotope dilution mass spectrometry.  

PubMed

In connection with pharmacokinetic studies on the antihypertensive drug 1-[2-ethoxy-2-(3'-pyridyl)ethyl]-4-(2'-methoxyphenyl)piperazine (IP/66) (I), appropriate high-performance liquid chromatographic (HPLC) and gas chromatographic-mass spectrometric isotope dilution (GC-MS-ID) methods for its determination in rat and human plasma, respectively, were developed. In both techniques, deproteinized and basified plasma samples were extracted and purified by adsorption on an Extrelut-1 column, then the drug was eluted with dichloromethane. Quantitative HPLC analysis was performed on a C8 reversed-phase column. The mobile phase was phosphate buffer (0.02 M, pH 2.8)-acetonitrile (65:35), with UV detection at 208 nm. The internal standard was 1-[2-butoxy-2-(3'-pyridyl)ethyl]-4-(2'-methoxyphenyl)piperazine, a homologue of I. The inter-assay coefficient of variation (C.V.) was 9.9% for a drug level of 2 micrograms/ml. Quantitative GC-MS-ID analysis was performed with a DB-17 fused-silica capillary column using the selected-ion monitoring technique. The deuterated form of I, 1-[2-ethoxy-2-(3'-pyridyl)ethyl]-4-2'-trideuteromethoxyphenyl)pipe razine, utilized as internal standard, was synthesized. The inter-assay C.V. was 7.36% for a drug level of 1 ng/ml. PMID:2723000

Agostini, O; Moneti, G; Bonacchi, G; Fedi, M; Manzini, S

1989-02-24

153

Collection of VLE data for acid gas - alkanolamine systems using Fourier transform infrared spectroscopy. Final report, September 29, 1990--September 30, 1996  

SciTech Connect

This report describes research from September 29, 1990 through September 30, 1996, involving the development a novel Fourier transform infrared (FTIR) spectroscopic apparatus and method for measuring vapor - liquid equilibrium (VLE) systems of carbon dioxide and hydrogen sulfide with aqueous alkanolamine solutions. The original apparatus was developed and modified as it was used to collect VLE data on acid gas systems. Vapor and liquid calibrations were performed for spectral measurements of hydrogen sulfide and carbon dioxide in the vapor and in solution with aqueous diethanolamine (DEA) and methyldiethanolamine (MDEA). VLE measurements were made of systems of hydrogen sulfide and carbon dioxide in 20 wt % DEA at 50{degrees}C and 40{degrees}C. VLE measurements were made of systems of hydrogen sulfide and carbon dioxide in 50 wt% and 23 wt% MDEA at 40{degrees}C and in 23 wt% MDEA at 50{degrees}C. VLE measurements were made of systems of hydrogen sulfide and carbon dioxide in 35 wt% MDEA + 5 wt% DEA and in 35 wt% MDEA + 10 wt% DEA at 40{degrees}C and 50{degrees}C. Measurements were made of residual amounts of carbon dioxide in each VLE system. The new FTIR spectrometer is now a consistently working and performing apparatus.

Bullin, J.A.; Rogers, W.J.

1996-11-01

154

Solubility of nitrous oxide in amine solutions  

SciTech Connect

The solubility of nitrous oxide (N{sub 2}O) in 13 amine solvents and solutions was correlated to amine mole fractions and temperature using feedforward neural networks. This general correlation, using a massive database, predicted N{sub 2}O solubility at temperatures between 283 and 398 K in pure solvents [H{sub 2}O, monoethanolamine (MEA), diethanolamine (DEA), methyldiethanolamine (MDEA), and 2-amino-2-methyl-1-propanolamine (AMP)], in binary aqueous amine solutions [H{sub 2}O/MEA, H{sub 2}O/DEA, H{sub 2}O/MDEA, and H{sub 2}O/AMP], and in ternary aqueous amine blends [AMP/MDEA/H{sub 2}O, AMP/DEA/H{sub 2}O, DEA/MDEA/H{sub 2}O, MDEA/MEA/H{sub 2}O, and AMP/MEA/H{sub 2}O]. Combined with the N{sub 2}O analogy, this present improved correlation can be advantageously implemented in amine plant design software and procedures for the prediction of CO{sub 2} solubility in amine blend solutions over wide temperature and concentration ranges.

Bensetiti, Z.; Iliuta, I.; Larachi, F.; Grandjean, B.P.A. [Laval Univ., Quebec (Canada)] [Laval Univ., Quebec (Canada)

1999-01-01

155

Designer Drug (DD) abuse in Poland; a review of the psychoactive and toxic properties of substances found from seizures of illegal drug products and the legal consequences thereof. Part II--piperazines/piperidines, phenylethylamines, tryptamines and miscellaneous 'others'.  

PubMed

As the second and concluding part, this paper continues the summary review of the scientific evidence obtained from the literature and focuses on the remaining 4/6 groupings of DDs identified in illegal products found in the huge drug seizures made recently in Poland. They consist of piperazines/piperidines, phenylethylamines, tryptamines, (briefly mentioned), and a miscellaneous 'others' category; cannabinoids and cathinones derivatives having being reviewed in the first part. Also included in the introduction and discussion sections, in both reviews, are some legal aspects variously interwoven with the science. It is thus intended that these two articles may help suitable legislation to be rapidly devised to make the prohibition of DDs permanent whenever deemed necessary, as well as providing an up-to-date reference source for those engaged in the DD issue; whether scientists or regulatory bodies. PMID:23311821

Bili?ski, Przemys?aw; Ho?ownia, Piotr; Kapka-Skrzypczak, Lucyna; Wojty?a, Andrzej

2012-01-01

156

Powder X-ray study of racemic (2RS,3RS)-5-amino-3-[4-(3-methoxyphenyl)piperazin-1-yl]-1,2,3,4-tetrahydronaphthalen-2-ol.  

PubMed

The structure of the title benzovesamicol analogue, C(21)H(27)N(3)O(2), an important compound for the diagnosis of Alzheimer's disease, has been determined by X-ray powder diffraction. The title compound was firstly synthesized and characterized by spectroscopic methods (FT-IR, and (13)C and (1)H NMR). The compound is a racemic mixture of enantiomers which crystallizes in the monoclinic system in a centrosymmetric space group (P2(1)/c). Crystallography, in particular powder X-ray diffraction, was pivotal in revealing that the enantio-resolution did not succeed. The piperazine ring is in a chair conformation, while the cyclohexene ring assumes a half-chair conformation. The crystal packing is dominated by intermolecular O-H···N hydrogen bonding which links molecules along the c direction. PMID:22051965

Assaad, Thaer; Rukiah, Mwaffak

2011-11-01

157

Metabolism, excretion, and pharmacokinetics of ((3,3-difluoropyrrolidin-1-yl)((2S,4S)-4-(4-(pyrimidin-2-yl)piperazin-1-yl)pyrrolidin-2-yl)methanone, a dipeptidyl peptidase inhibitor, in rat, dog and human.  

PubMed

The disposition of 3,3-difluoropyrrolidin-1-yl{(2S,4S)-4-[4-(pyrimidin-2-yl)piperazin-1-yl]pyrrolidin-2-yl}methanone (PF-00734200), a dipeptidyl peptidase IV inhibitor that progressed to phase 3 for the treatment of type 2 diabetes, was examined in rats, dogs, and humans after oral administration of a single dose of [(14)C]PF-00734200. Mean recoveries of administered radioactivity were 97.1, 92.2, and 87.2% in rats, dogs, and humans, respectively. The majority of radioactive dose was detected in the urine of dogs and humans and in the feces of rats. Absorption of PF-00734200 was rapid in all species, with maximal plasma concentrations of radioactivity achieved within 1 h after the dose. Circulating radioactivity was primarily composed of the parent drug (79.9, 80.2, and 94.4% in rat, dog, and human, respectively). The major route of metabolism was due to hydroxylation at the 5' position of the pyrimidine ring (M5) in all species. In vitro experiments with recombinant cytochrome P450 isoforms suggested that the formation of M5 was catalyzed both by CYP2D6 and CYP3A4. Molecular docking simulations showed that the 5' position of the pyrimidine moiety of PF-00734200 can access the heme iron-oxo of both CYP3A4 and CYP2D6 in an energetically favored orientation. Other metabolic pathways included amide hydrolysis (M2), N-dealkylation at the piperazine nitrogen (M3) and an unusual metabolite resulting from scission of the pyrimidine ring (M1). Phase II metabolic pathways included the following: carbamoyl glucuronidation (M9), glucosidation (M15) on the pyrrolidine nitrogen, and conjugation with creatinine to form an unusual metabolite/metabonate (M16). The data from these studies suggest that PF-00734200 is eliminated by both metabolism and renal clearance. PMID:22896728

Sharma, Raman; Sun, Hao; Piotrowski, David W; Ryder, Tim F; Doran, Shawn D; Dai, Haiqing; Prakash, Chandra

2012-11-01

158

Surface tension of aqueous solutions of diethanolamine and triethanolamine from 25 C to 50 C  

SciTech Connect

Aqueous solutions of alkanolamines such as monoethanolamine (MEA), diethanolamine (DEA), triethanolamine (TEA), N-methyldiethanolamine (MDEA), and 2-amino-2-methyl-1-propanol (AMP) are good solvents for the removal of acid gases such CO{sub 2} and H{sub 2}S from the gas streams of many processes in the natural gas, ammonia synthesis, and some chemical industries. The surface tension of aqueous solutions of diethanolamine and triethanolamine was measured over the entire concentration range at temperatures of 25 C to 50 C. The experimental values were correlated with temperature and with mole fraction. The maximum deviation was in both cases always less than 0.5%.

Vazquez, G.; Alvarez, E.; Rendo, R.; Romero, E.; Navaza, J.M. [Univ. of Santiago de Compostela (Spain). Dept. of Chemical Engineering] [Univ. of Santiago de Compostela (Spain). Dept. of Chemical Engineering

1996-07-01

159

Physical solubility of carbon dioxide in aqueous alkanolamines via nitrous oxide analogy  

SciTech Connect

In the petrochemical and natural gas industry, the removal of carbon dioxide and hydrogen sulfide from process gas streams is commonly achieved by reacting these impurities with aqueous alkanolamines. Van Krevelen coefficients for protonated monoethanolamine (MEA), diethanolamine (DEA), and methyldiethanolamine (MDEA), the carbamates of MEA and DEA, and the bicarbonate ion have been determined experimentally from measurements of the solubility of N[sub 2]O at 25 C and atmospheric pressure in aqueous solutions of these ions. Measured values different significantly from values recommended by others in the absence of experimental data. By analogy with N[sub 2]O, the solubility of carbon dioxide in the same solutions can be estimated.

Browning, G.J.; Weiland, R.H. (Univ. of Newcastle, Callaghan, New South Wales (Australia). Dept. of Chemical Engineering)

1994-10-01

160

Acid gas absorption in aqueous solutions of mixed amines  

SciTech Connect

A mass transfer model has been developed to describe the rate of absorption (or desorption) of H{sub 2}S and CO{sub 2} in aqueous blends of a tertiary and a secondary or a primary amine. The model is based on penetration theory, and all significant chemical reactions are incorporated in the model. The reactions are taken to be reversible, with reactions involving only a proton transfer considered to be at equilibrium. The particular amines studied in this research were methyldiethanolamine (MDEA), a tertiary amine, and diethanolamine (DEA), a secondary amine. Key physicochemical data needed in the model, such as diffusion coefficients, kinetic rate constants, and gas solubilities, were measured. Experimental absorption rates of CO{sub 2} and H{sub 2}S were measured in a model gas-liquid contacting device and were compared with model predictions. Experiments were carried out for single amine solutions (both MDEA and DEA) and for amine blends.

Rinker, E.B.; Ashour, S.S.; Sandall, O.C. [Univ. of California, Santa Barbara, CA (United States)

1996-12-31

161

Amine plant troubleshooting and optimization  

SciTech Connect

A systematic method for troubleshooting and optimization of amine plants, if properly used, will result in fewer plant upsets, quick and correct responses to changing conditions and long-term profitable operations of any amine unit. It is important for amine plants to maintain safe, continuous and optimized operations for short- and long-term success. Effective and fast resolution of maine unit upsets plays a large part in this success. These considerations are as important in plants using generic amines such as monoethanolamine (MEA), diethanolamine (DEA), methyldiethanolamine (MDEA) and specialty amines based on MDEA. The key to troubleshooting and optimization is a systematic approach. Developing and using control charts can also be used to monitor amine plant operations. By using these techniques collectively, a formal method for troubleshooting and optimization can be established. This will ultimately result in a more trouble-free, continuous operation.

Abry, R.G.F. [Dow Chemical Co., Ft. Saskatchewan, Alberta (Canada); DuPart, M.S. [Dow Chemical Co., Freeport, TX (United States)

1995-04-01

162

Exploring the Solid State Properties of Enzymatic Poly(amine-co-ester) Terpolymers to Expand their Applications in Gene Transfection  

PubMed Central

Polymers bearing amino functional groups are an important class of materials capable of serving as non-viral carriers for DNA delivery to living cells. In this work biodegradable poly(amine-co-ester) terpolymers were synthesized via ring-opening and polycondensation copolymerization of lactone (?-caprolactone (CL), ?-dodecalactone, ?-pentadecalactone (PDL), and ?-hexadecalactone) with diethyl sebacate (DES) and N-methyldiethanolamine (MDEA) in diphenyl ether, catalyzed by Candida antarctica lipase B (CALB). All lactone-DES-MDEA terpolymers had random distributions of lactone, sebacate, MDEA repeat units in the polymer chains. PDL-DES-MDEA terpolymers were studied in the composition range from 21 mol% to 90 mol% PDL whereas the terpolymers with other lactones were investigated at a single composition (80 mol% lactone). DSC and WAXS analyses showed that all investigated terpolymers crystallize in their respective homopolylactone crystal lattice. Terpolymers with large lactones and a high lactone content melt well above room temperature and are hard solids, whereas terpolymers with small lactones (e.g. CL) or with a low lactone content melt below/around ambient temperature and are waxy/gluey materials. Given the importance of hydrophobicity in influencing gene delivery, water contact angle measurements were carried out on lactone-DES-MDEA terpolymers showing that it is possible to tune the hydrophilic-to-hydrophobic balance by varying polymer composition and size of lactone units. To demonstrate the feasibility of using solid terpolymers as nanocarriers for DNA delivery, PDL-DES-MDEA copolymers with 65–90% PDL were successfully transformed into free-standing nanoparticles with average particle size ranging from 163 to 175 nm. Our preliminary results showed that LucDNA-loaded nanoparticles of the terpolymer with 65% PDL were effective for luciferase gene transfection of HEK293 cells. PMID:24683469

Voevodina, Irina; Scandola, Mariastella; Zhang, Junwei; Jiang, Zhaozhong

2014-01-01

163

N-(3-Fluoro-4-(4-(2-methoxy or 2,3-dichlorophenyl) piperazine-1-yl)-butyl)-aryl carboxamides as Selective Dopamine D3 Receptor Ligands: Critical Role of the Carboxamide Linker for D3 Receptor Selectivity  

PubMed Central

N-(3-fluoro-4-(4-(2,3-dichloro- or 2-methoxyphenyl)piperazine-1-yl)-butyl)-aryl carboxamides were prepared and evaluated for binding and function at dopamine D3 (D3R) and D2 receptors (D2R). In this series, we discovered some of the most D3R selective compounds reported to date, (e.g. 8d and 8j >1000-fold D3R-selective over D2R.) In addition, chimeric receptor studies further identified the second extracellular (E2) loop as an important contributor to D3R binding selectivity. Further, compounds lacking the carbonyl group in the amide linker were synthesized and while these amine-linked analogues bound with similar affinities to the amides at D2R, this modification dramatically reduced binding affinities at D3R by >100-fold (e.g. D3RKi for 15b = 393 v. for 8j = 2.6 nM) resulting in compounds with significantly reduced D3R selectivity. This study supports a pivotal role for the D3R E2 loop and the carbonyl group in the 4-phenylpiperazine class of compounds and further reveals a point of separation between structure-activity relationships at D3R and D2R. PMID:21495689

Banala, Ashwini K.; Levy, Benjamin A.; Khatri, Sameer S.; Furman, Cheryse A.; Roof, Rebecca A.; Mishra, Yogesh; Griffin, Suzy A.; Sibley, David R.; Luedtke, Robert R.; Newman, Amy Hauck

2011-01-01

164

Metabolism and excretion of 5-ethyl-2-{5-[4-(2-hydroxyethyl)piperazine-1-sulfonyl]-2-propoxyphenyl}-7-propyl-3,5-dihydropyrrolo[3,2-d]-pyrimidin-4-one (SK3530) in rats.  

PubMed

The in vitro and in vivo metabolism of a novel PDE 5 inhibitor, SK3530, was investigated in rats. Bile, plasma, feces, urine and liver samples were collected and analyzed using a high-performance liquid chromatography (HPLC) system equipped with ultraviolet (UV), mass spectrometric and radioactivity detectors. After a single oral administration, the mean radiocarbon recovery was 92.32+/-6.26%, with 91.25+/-6.25 and 1.07+/-0.21% in the feces and urine, respectively. The biliary excretion of radioactivity for the first 24 h period was approximately 38.82%, suggesting that SK3530 is cleared by hepatobiliary excretion. In vitro incubation of SK3530 with rat and human liver microsomes resulted in the formation of twelve and ten metabolites, respectively. SK3530 was extensively metabolized to twenty different metabolites, including three glucuronide and three sulfate conjugates in rats. The structures of these metabolites were elucidated based on MSn spectral analyses. Six major metabolic pathways were identified in the rat: N-dealkylation and oxidation of the hydroxyethyl moiety; N,N-deethylation and hydroxylation of the piperazine ring; hydroxylation of the propyl group and sulfate conjugation. An additional metabolite due to aromatic hydroxylation was also identified in hepatic microsomes. PMID:17318927

Lee, Jaeick; Yoo, Hye Hyun; Rhim, Kwang Jin; Sohn, Dong-Ryul; Kim, Dong-Hyun

2007-01-01

165

Poly[[di­aqua­[?-1,4-bis(pyridin-4-ylmeth­yl)piperazine-?2 N:N?]{?-2,2?-[(1,4-phenyl­ene)bis(­oxy)]di­acetato-?2 O:O?}cobalt(II)] penta­hydrate  

PubMed Central

In the title compound, {[Co(C10H8O6)(C16H20N4)(H2O)2]·5H2O}n, octa­hedrally coordinated CoII ions on crystallographic inversion centres are bound by trans O atoms belonging to two hydro­quinone-O,O?-di­acetate (hqda) anions {systematic name: 2,2?-[(1,4-phenyl­ene)bis­(­oxy)]di­acetate}, two trans-pyridine N-donor atoms from two bis­(pyridin-4-ylmeth­yl)piperazine (4-bpmp) ligands, and two trans aqua ligands. The exobidentate hqda and 4-bpmp ligands form [Co(hqda)(4-bpmp)(H2O)2]n coordination polymer layers parallel to (110) that are anchored into the full crystal structure by O—H?O hydrogen bonding between aqua ligands and ligated hqda O atoms. Disordered water mol­ecules of crystallization occupy incipient channels along [100]. However, these could not modeled reliably and so they were treated with SQUEEZE in PLATON [Spek (2009 ?). Acta Cryst. D65, 148–155]; the crystal data take the presence of these mol­ecules into account. The crystal under investigation was twinned by non-merohedry, the twin fraction of the components being 53.3% and 46.7%. Only data from the major twin component were used in the refinement. PMID:24940193

Sample, Alexander D.; LaDuca, Robert L.

2014-01-01

166

Pharmacological Preconditioning of Mesenchymal Stem Cells with Trimetazidine (1-[2,3,4-Trimethoxybenzyl]piperazine) Protects Hypoxic Cells against Oxidative Stress and Enhances Recovery of Myocardial Function in Infarcted Heart through Bcl-2 Expression  

PubMed Central

Stem cell transplantation is a possible therapeutic option to repair ischemic damage to the heart. However, it is faced with a number of challenges including the survival of the transplanted cells in the ischemic region. The present study was designed to use stem cells preconditioned with trimetazidine (1-[2,3,4-trimethoxybenzyl]piperazine; TMZ), a widely used anti-ischemic drug for treating angina in cardiac patients, to increase the rate of their survival after transplantation. Bone marrow-derived rat mesenchymal stem cells (MSCs) were subjected to a simulated host tissue environment by culturing them under hypoxia (2% O2) and using hydrogen peroxide (H2O2) to induce oxidative stress. MSCs were preconditioned with 10 ?M TMZ for 6 h followed by treatment with 100 ?M H2O2 for 1 h and characterized for their cellular viability and metabolic activity. The preconditioned cells showed a significant protection against H2O2-induced loss of cellular viability, membrane damage, and oxygen metabolism accompanied by a significant increase in HIF-1?, survivin, phosphorylated Akt (pAkt), and Bcl-2 protein levels and Bcl-2 gene expression. The therapeutic efficacy of the TMZ-preconditioned MSCs was evaluated in an in vivo rat model of myocardial infarction induced by permanent ligation of left anterior descending coronary artery. A significant increase in the recovery of myocardial function and up-regulation of pAkt and Bcl-2 levels were observed in hearts transplanted with TMZ-preconditioned cells. This study clearly demonstrated the potential benefits of pharmacological preconditioning of MSCs with TMZ for stem cell therapy for repairing myocardial ischemic damage. PMID:19218529

Wisel, Sheik; Khan, Mahmood; Kuppusamy, M. Lakshmi; Mohan, I. Krishna; Chacko, Simi M.; Rivera, Brian K.; Sun, Benjamin C.; Hideg, Kálmán; Kuppusamy, Periannan

2009-01-01

167

Neuroprotective targets through which 6-acetyl-3-(4-(4-(4-fluorophenyl)piperazin-1-yl)butyl)benzo[d]oxazol-2(3H)-one (SN79), a sigma receptor ligand, mitigates the effects of methamphetamine in vitro.  

PubMed

Exposure to high or repeated doses of methamphetamine can cause hyperthermia and neurotoxicity, which are thought to increase the risk of developing a variety of neurological conditions. Sigma receptor antagonism can prevent methamphetamine-induced hyperthermia and neurotoxicity, but the underlying cellular targets through which the neuroprotection is conveyed remain unknown. Differentiated NG108-15 cells were thus used as a model system to begin elucidating the neuroprotective mechanisms targeted by sigma receptor antagonists to mitigate the effects of methamphetamine. In differentiated NG108-15 cells, methamphetamine caused the generation of reactive oxygen/nitrogen species, an increase in PERK-mediated endoplasmic reticulum stress and the activation of caspase-3, -8 and -9, ultimately resulting in apoptosis at micromolar concentrations, and necrotic cell death at higher concentrations. The sigma receptor antagonist, 6-acetyl-3-(4-(4-(4-fluorophenyl)piperazin-1-yl)butyl)benzo[d]oxazol-2(3H)-one (SN79), attenuated methamphetamine-induced increases in reactive oxygen/nitrogen species, activation of caspase-3, -8 and -9 and accompanying cellular toxicity. In contrast, 1,3-di(2-tolyl)-guanidine (DTG), a sigma receptor agonist, shifted the dose response curve of methamphetamine-induced cell death towards the left. To probe the effect of temperature on neurotoxicity, NG108-15 cells maintained at an elevated temperature (40 °C) exhibited a significant and synergistic increase in cell death in response to methamphetamine, compared to cells maintained at a normal cell culture temperature (37 °C). SN79 attenuated the enhanced cell death observed in the methamphetamine-treated cells at 40 °C. Together, the data demonstrate that SN79 reduces methamphetamine-induced reactive oxygen/nitrogen species generation and caspase activation, thereby conveying neuroprotective effects against methamphetamine under regular and elevated temperature conditions. PMID:24380829

Kaushal, Nidhi; Robson, Matthew J; Rosen, Abagail; McCurdy, Christopher R; Matsumoto, Rae R

2014-02-01

168

9?-Hy­droxy-12-{[4-(4-hy­droxy­phen­yl)piperazin-1-yl]meth­yl}-4,8-dimethyl-3,14-dioxatri­cyclo­[9.3.0.02,4]tetra­dec-7-en-13-one  

PubMed Central

The title compound, C25H34N2O5, was synthesized from 9?-hy­droxy­parthenolide (9?-hy­droxy-4,8-dimethyl-12-methylen-3, 14-dioxa-tri­cyclo­[9.3.0.02,4]tetra­dec-7-en-13-one), which in turn was isolated from the chloro­form extract of the aerial parts of Anvillea radiata. The mol­ecule comprises a ten-membered ring fused to a five-membered ring with an additional ep­oxy ring system fused to the ten-membered ring. The five-membered ring also carries a 4-hy­droxy­phenyl-piperazin-1-ylmethyl substituent. The ten-membered ring adopts an approximate chair–chair conformation, while the piperazine ring displays a chair conformation and the five-membered ring shows an envelope conformation with the C atom closest to the hy­droxy group forming the flap. Two C atoms in the phenyl ring and the O atom of the hydroxyl group are disordered over two sites, with an occupancy ratio of 0.53?(5):0.47?(5). An intra­molecular O—H?N hydrogen-bond stabilizes the mol­ecular conformation. In the crystal, C—H?O hydrogen bonds link the mol­ecules into zigzag chains running along the a-axis direction. PMID:24860343

Loubidi, Mohamed; Benharref, Ahmed; El Ammari, Lahcen; Saadi, Mohamed; Berraho, Moha

2014-01-01

169

9?-Hy-droxy-12-{[4-(4-hy-droxy-phen-yl)piperazin-1-yl]meth-yl}-4,8-dimethyl-3,14-dioxatri-cyclo-[9.3.0.0(2,4)]tetra-dec-7-en-13-one.  

PubMed

The title compound, C25H34N2O5, was synthesized from 9?-hy-droxy-parthenolide (9?-hy-droxy-4,8-dimethyl-12-methylen-3, 14-dioxa-tri-cyclo-[9.3.0.0(2,4)]tetra-dec-7-en-13-one), which in turn was isolated from the chloro-form extract of the aerial parts of Anvillea radiata. The mol-ecule comprises a ten-membered ring fused to a five-membered ring with an additional ep-oxy ring system fused to the ten-membered ring. The five-membered ring also carries a 4-hy-droxy-phenyl-piperazin-1-ylmethyl substituent. The ten-membered ring adopts an approximate chair-chair conformation, while the piperazine ring displays a chair conformation and the five-membered ring shows an envelope conformation with the C atom closest to the hy-droxy group forming the flap. Two C atoms in the phenyl ring and the O atom of the hydroxyl group are disordered over two sites, with an occupancy ratio of 0.53?(5):0.47?(5). An intra-molecular O-H?N hydrogen-bond stabilizes the mol-ecular conformation. In the crystal, C-H?O hydrogen bonds link the mol-ecules into zigzag chains running along the a-axis direction. PMID:24860343

Loubidi, Mohamed; Benharref, Ahmed; El Ammari, Lahcen; Saadi, Mohamed; Berraho, Moha

2014-05-01

170

12-{[4-(4-Bromo-phen-yl)piperazin-1-yl]meth-yl}-9?-hy-droxy-4,8-dimethyl-3,14-dioxatri-cyclo-[9.3.0.0(2,4)]tetra-dec-7-en-13-one.  

PubMed

The title compound, C25H33BrN2O4, was synthesized from 9?-hy-droxy-parthenolide (9?-hy-droxy-4,8-dimethyl-12-methylen-3,14-dioxa-tri-cyclo-[9.3.0.0(2,4)]tetra-dec-7-en-13-one), which was isolated from the chloro-form extract of the aerial parts of Anvillea radiata. The mol-ecule is built up from two fused five- and ten-membered rings with an additional ep-oxy ring system and a bromo-phenyl-piperazine group as a substituent. The ten-membered ring adopts an approximate chair-chair-chair conformation, while the piperazine ring displays a chair conformation and the five-membered ring shows an envelope conformation with the C atom closest to the hy-droxy group forming the flap. An intra-molecular O-H?N hydrogen bond stabilizes the mol-ecular conformation. The crystal packing features C-H?O hydrogen bonds, which link the mol-ecules into zigzag chains running along the b-axis direction. PMID:24826186

Loubidi, Mohamed; Benharref, Ahmed; El Ammari, Lahcen; Saadi, Mohamed; Berraho, Moha

2014-04-01

171

12-{[4-(4-Bromo­phen­yl)piperazin-1-yl]meth­yl}-9?-hy­droxy-4,8-dimethyl-3,14-dioxatri­cyclo­[9.3.0.02,4]tetra­dec-7-en-13-one  

PubMed Central

The title compound, C25H33BrN2O4, was synthesized from 9?-hy­droxy­parthenolide (9?-hy­droxy-4,8-dimethyl-12-methylen-3,14-dioxa-tri­cyclo­[9.3.0.02,4]tetra­dec-7-en-13-one), which was isolated from the chloro­form extract of the aerial parts of Anvillea radiata. The mol­ecule is built up from two fused five- and ten-membered rings with an additional ep­oxy ring system and a bromo­phenyl­piperazine group as a substituent. The ten-membered ring adopts an approximate chair–chair–chair conformation, while the piperazine ring displays a chair conformation and the five-membered ring shows an envelope conformation with the C atom closest to the hy­droxy group forming the flap. An intra­molecular O—H?N hydrogen bond stabilizes the mol­ecular conformation. The crystal packing features C—H?O hydrogen bonds, which link the mol­ecules into zigzag chains running along the b-axis direction. PMID:24826186

Loubidi, Mohamed; Benharref, Ahmed; El Ammari, Lahcen; Saadi, Mohamed; Berraho, Moha

2014-01-01

172

Ether modifications to 1-[2-(3,4-dimethoxyphenyl)ethyl]-4-(3-phenylpropyl)piperazine (SA4503): Effects on binding affinity and selectivity for sigma receptors and monoamine transporters.  

PubMed

Two series of novel ether analogs of the sigma (?) receptor ligand 1-[2-(3,4-dimethoxyphenyl)ethyl]-4-(3-phenylpropyl)piperazine (SA4503) have been prepared. In one series, the alkyl portion of the 4-methoxy group was replaced with allyl, propyl, bromoethyl, benzyl, phenethyl, and phenylpropyl moieties. In the second series, the 3,4-dimethoxy was replaced with cyclic methylenedioxy, ethylenedioxy and propylenedioxy groups. These ligands, along with 4-O-des-methyl SA4503, were evaluated for ?1 and ?2 receptor affinity, and compared to SA4503 and several known ether analogs. SA4503 and a subset of ether analogs were also evaluated for dopamine transporter (DAT) and serotonin transporter (SERT) affinity. The highest ?1 receptor affinities, Ki values of 1.75-4.63nM, were observed for 4-O-des-methyl SA4503, SA4503 and the methylenedioxy analog. As steric bulk increased, ?1 receptor affinity decreased, but only to a point. Allyl, propyl and bromoethyl substitutions gave ?1 receptor Ki values in the 20-30nM range, while bulkier analogs having phenylalkyl, and Z- and E-iodoallyl, ether substitutions showed higher ?1 affinities, with Ki values in the 13-21nM range. Most ligands studied exhibited comparable ?1 and ?2 affinities, resulting in little to no subtype selectivity. SA4503, the fluoroethyl analog and the methylenedioxy congener showed modest six- to fourteen-fold selectivity for ?1 sites. DAT and SERT interactions proved much more sensitive than ? receptor interactions to these structural modifications. For example, the benzyl congener (?1Ki=20.8nM; ?2Ki=16.4nM) showed over 100-fold higher DAT affinity (Ki=121nM) and 6-fold higher SERT affinity (Ki=128nM) than the parent SA4503 (DAT Ki=12650nM; SERT Ki=760nM). Thus, ether modifications to the SA4503 scaffold can provide polyfunctional ligands having a broader spectrum of possible pharmacological actions. PMID:25468036

Xu, Rong; Lord, Sarah A; Peterson, Ryan M; Fergason-Cantrell, Emily A; Lever, John R; Lever, Susan Z

2015-01-01

173

Collection of VLE data for acid gas---alkanolamine systems using fourier transform infrared spectroscopy. [Vapor-liquid equilibrium  

SciTech Connect

The industrial standard process for the purification of natural gas is to remove acid gases, mainly hydrogen sulfide and carbon dioxide, by the absorption and reaction of these gases with alkanolamines. Inadequate data for vapor--liquid equilibrium (VLE) hinder the industry from converting operations to more energy efficient amine mixtures and conserving energy. Some energy reductions have been realized in the past decade by applying such amine systems as hindered'' amines, methyldiethanolamine (MDEA), and MDEA based amine mixtures. However, the lack of reliable and accurate fundamental VLE data impedes the commercial application of these more efficient alkanolamine systems. The first project objective is to improve the accuracy of vapor--liquid equilibrium measurements at low hydrogen sulfide concentrations. The second project objective is to measure the VLE for amine mixtures. By improving the accuracy of the VLE measurements on MDEA and mixtures with other amines, energy saving can be quickly and confidently implemented in the many existing absorption units already in use. If about 25% of the existing 95.3 billion SCFD gas purification capacity is converted to these new amine systems, the energy savings are estimated to be about 3 [times] 10[sup 14] BTU/yr.

Bullin, J.A.; Frazier, R.E.

1992-01-01

174

Densities of aqueous blended amines  

SciTech Connect

Solutions of alkanolamines are an industrially important class of compounds used in the natural gas and synthetic ammonia industries and petroleum chemical plants for the removal of CO{sub 2} and H{sub 2}S from gas streams. The densities of aqueous mixtures of diethanolamine (DEA) + N-methyldiethanolamine (MDEA) + water, DEA + 2-amino-2-methyl-1-propanol (AMP) + water, and monoethanolamine (MEA) + 2-piperidineethanol (2-PE) + water were measured from 30 C to 80 C. A Redlich-Kister equation of the excess volume was applied to represent the density. Based on the available density data for five ternary systems: MEA + MDEA + H{sub 2}O, MEA + AMP + H{sub 2}O, DEA + MDEA + H{sub 2}O, DEA + AMP + H{sub 2}O, and MEA + 2-PE + H{sub 2}O, a generalized set of binary parameters were determined. The density calculations show quite satisfactory results. The overall average absolute percent deviation is about 0.04% for a total of 686 data points.

Hsu, C.H.; Li, M.H. [Chung Yuan Christian Univ., Chung Li (Taiwan, Province of China). Dept. of Chemical Engineering] [Chung Yuan Christian Univ., Chung Li (Taiwan, Province of China). Dept. of Chemical Engineering

1997-05-01

175

Viscosities of aqueous blended amines  

SciTech Connect

Solutions of alkanolamines are an industrially important class of compounds used in the natural gas, oil refineries, petroleum chemical plants, and synthetic ammonia industries for the removal of acidic components like CO{sub 2} and H{sub 2}S from gas streams. The viscosities of aqueous mixtures of diethanolamine (DEA) + N-methyldiethanolamine (MDEA), DEA + 2-amino-2-methyl-1-propanol (AMP), and monoethanolamine (MEA) + 2-piperidineethanol (2-PE) were measured from 30 C to 80 C. A Redlich-Kister equation for the viscosity deviation was applied to represent the viscosity. On the basis of the available viscosity data for five ternary systems, MEA + MDEA + H{sub 2}O, MEA + AMP + H{sub 2}O, DEA + MDEA + H{sub 2}O, DEA + AMP + H{sub 2}O, and MEA + 2-PE + H{sub 2}O, a generalized set of binary parameters were determined. For the viscosity calculation of the systems tested, the overall average absolute percent deviation is about 1.0% for a total of 499 data points.

Hsu, C.H.; Li, M.H. [Chung Yuan Christian Univ., Chung Li (Taiwan, Province of China). Dept. of Chemical Engineering] [Chung Yuan Christian Univ., Chung Li (Taiwan, Province of China). Dept. of Chemical Engineering

1997-07-01

176

Evaluation of the electrode method for measuring H/sub 2/S vapor pressure over alkanolamine solutions  

SciTech Connect

A new electrode method for measuring the equilibrium vapor pressure of H/sub 2/S over any sulfide solution was tested. The method relates the electropotential difference produced between pH and silver/sulfide ion specific electrodes to the H/sub 2/S equilibrium vapor pressure of solution. The experimental technique is simple and time efficient. In this work, H/sub 2/S equilibrium vapor pressures were measured from 10/sup -4/ kPa to 10 kPa at 25/sup 0/C in aqueous solutions of monoethanolamine-MEA (2.5 N), diethanolamine-DEA (2.0N), and methyldiethanolamine-MDEA (1.0 N and 4.28 N). The H/sub 2/S vapor-liquid equilibria (VLE) of 4.28 N MDEA was also examined at 40/sup 0/C. The results indicate that the addition of MEA to a MDEA solution reduces the H/sub 2/S vapor pressure only at low H/sub 2/S loadings.

Austgen, D.M.; Rochelle, G.T.

1987-01-01

177

Collection of VLE data for acid gas---alkanolamine systems using fourier transform infrared spectroscopy. Phase 2, October 1, 1991--September 30, 1992  

SciTech Connect

The industrial standard process for the purification of natural gas is to remove acid gases, mainly hydrogen sulfide and carbon dioxide, by the absorption and reaction of these gases with alkanolamines. Inadequate data for vapor--liquid equilibrium (VLE) hinder the industry from converting operations to more energy efficient amine mixtures and conserving energy. Some energy reductions have been realized in the past decade by applying such amine systems as ``hindered`` amines, methyldiethanolamine (MDEA), and MDEA based amine mixtures. However, the lack of reliable and accurate fundamental VLE data impedes the commercial application of these more efficient alkanolamine systems. The first project objective is to improve the accuracy of vapor--liquid equilibrium measurements at low hydrogen sulfide concentrations. The second project objective is to measure the VLE for amine mixtures. By improving the accuracy of the VLE measurements on MDEA and mixtures with other amines, energy saving can be quickly and confidently implemented in the many existing absorption units already in use. If about 25% of the existing 95.3 billion SCFD gas purification capacity is converted to these new amine systems, the energy savings are estimated to be about 3 {times} 10{sup 14} BTU/yr.

Bullin, J.A.; Frazier, R.E.

1992-12-01

178

In vitro and in vivo evaluation of N-{2-[4-(3-Cyanopyridin-2-yl)piperazin-1-yl]ethyl}-3-[(11) C]methoxybenz-amide, a positron emission tomography (PET) radioligand for dopamine D4 receptors, in rodents.  

PubMed

The D4 dopamine receptor belongs to the D2 -like family of dopamine receptors, and its exact regional distribution in the central nervous system is still a matter of considerable debate. The availability of a selective radioligand for the D4 receptor with suitable properties for positron emission tomography (PET) would help resolve issues of D4 receptor localization in the brain, and the presumed diurnal change of expressed protein in the eye and pineal gland. We report here on in vitro and in vivo characteristics of the high-affinity D4 receptor-selective ligand N-{2-[4-(3-cyanopyridin-2-yl)piperazin-1-yl]ethyl}-3-[(11) C]methoxybenzamide ([(11) C]2) in rat. The results provide new insights on the in vitro properties that a brain PET dopamine D4 radioligand should possess in order to have improved in vivo utility in rodents. PMID:25238073

Leopoldo, Marcello; Selivanova, Svetlana V; Müller, Adrienne; Lacivita, Enza; Schetz, John A; Ametamey, Simon M

2014-09-01

179

21 CFR 520.1807 - Piperazine.  

Code of Federal Regulations, 2010 CFR

...human consumption. Consult your veterinarian for assistance in the diagnosis, treatment, and control of parasitism. (2) Turkeys —(i) Amount. 100 milligrams per bird up to 12 weeks and 200 milligrams per bird over 12 weeks. (ii)...

2010-04-01

180

21 CFR 520.1807 - Piperazine.  

Code of Federal Regulations, 2013 CFR

...For use in drinking water or feed. Use as sole source...For use in drinking water or feed. Use as sole source of...control of parasitism. (3) Swine —(i) Amount. 50 milligrams...For use in drinking water or feed. Use as sole source...

2013-04-01

181

21 CFR 520.1807 - Piperazine.  

Code of Federal Regulations, 2012 CFR

...milligrams per pound of body weight. (ii) Indications for use. For removal of large roundworm (Ascaris suum ) and nodular worms (Oesophagostomum spp.). (iii) Limitations. For use in drinking water or feed. Use as sole source of...

2012-04-01

182

21 CFR 520.1807 - Piperazine.  

Code of Federal Regulations, 2011 CFR

...milligrams per pound of body weight. (ii) Indications for use. For removal of large roundworm (Ascaris suum ) and nodular worms (Oesophagostomum spp.). (iii) Limitations. For use in drinking water or feed. Use as sole source of...

2011-04-01

183

21 CFR 520.1807 - Piperazine.  

...milligrams per pound of body weight. (ii) Indications for use. For removal of large roundworm (Ascaris suum ) and nodular worms (Oesophagostomum spp.). (iii) Limitations. For use in drinking water or feed. Use as sole source of...

2014-04-01

184

Determination of rate constants for the reaction between methyldiethanolamine and carbon dioxide  

E-print Network

the gas cylinder to a mass flow controller. For the 24 first 42 runs, the controller was a Brooks model 5811 with a capacity of 20 standard liters per minute (SLPM) of air. For the remaining runs, the Brooks controller was placed in parallel with a... A-Impeller Drive Assembly B-Gas Outlet C- Thermowell D-Gas Outlet E-Autoclave Top F-Liquid Inlet G-Level Controller Electrode H-Hester I-Autoclave Body J-Reactor K-Liquid Outlet L-Fri, ted Disc H-Impeller N-Liquid Holdup Area 0-Outer...

Brabson, Charles Meade

2012-06-07

185

Discovery of 8-Cyclopentyl-2-[4-(4-methyl-piperazin-1-yl)-phenylamino]-7-oxo-7,8-dihydro-pyrido[2,3-d]pyrimidine-6-carbonitrile (7x) as a Potent Inhibitor of Cyclin-Dependent Kinase 4 (CDK4) and AMPK-Related Kinase 5 (ARK5)  

PubMed Central

The success of imatinib, a BCR-ABL inhibitor for the treatment of chronic myelogenous leukemia, has created a great impetus for the development of additional kinase inhibitors as therapeutic agents. However, the complexity of cancer has led to recent interest in polypharmacological approaches for developing multikinase inhibitors with low toxicity profiles. With this goal in mind, we analyzed more than 150 novel cyano pyridopyrimidine compounds and identified structure–activity relationship trends that can be exploited in the design of potent kinase inhibitors. One compound, 8-cyclopentyl-2-[4-(4-methyl-piperazin-1-yl)-phenylamino]-7-oxo-7,8-dihydro-pyrido[2,3-d]pyrimidine-6-carbonitrile (7x), was found to be the most active, inducing apoptosis of tumor cells at a concentration of approximately 30–100 nM. In vitro kinase profiling revealed that 7x is a multikinase inhibitor with potent inhibitory activity against the CDK4/CYCLIN D1 and ARK5 kinases. Here, we report the synthesis, structure–activity relationship, kinase inhibitory profile, in vitro cytotoxicity, and in vivo tumor regression studies by this lead compound. PMID:24417566

2015-01-01

186

Diaqua­(5-carb­oxy­benzene-1,3-dicarboxyl­ato-?O 1)[8-ethyl-5-oxo-2-(piperazin-4-ium-1-yl)-5,8-dihydro­pyrido[2,3-d]pyrimidine-6-carboxyl­ato-?2 O 5,O 6]zinc monohydrate  

PubMed Central

In the title compound, [Zn(C14H17N5O3)(C9H4O6)(H2O)2]·H2O, the complex mol­ecule exists in a zwitterionic form. The ZnII ion exhibits a distorted tetra­gonal-pyramidal geometry, being coordinated by two O atoms from the zwitterionic 8-ethyl-5-oxo-2-(piperazin-4-ium-1-yl)-5,8-dihydro­pyrido[2,3-d]pyrimidine-6-carboxyl­ate (L) ligand, one O atom from the 5-carb­oxy­benzene-1,3-dicarboxyl­ate dianion, [Hbtc]2?, and two O atoms from two aqua ligands. In the crystal, N—H?O and O—H?O hydrogen bonds link the components into a three-dimensional structure. The crystal packing exhibits ?–? inter­actions between the aromatic rings, with centroid–centroid distances in the range 3.466?(3)–3.667?(3)?Å. PMID:23424417

Ye, Zhong-Li; Xin, Guang-Hua; Zhang, Fu-Tian; Xiao, Dong-Rong

2013-01-01

187

Synthesis and in vivo evaluation of [18F]2-(4-(4-(2-(2-fluoroethoxy)phenyl)piperazin-1-yl)butyl)-4-methyl-1,2,4-triazine-3,5(2H,4H)-dione ([18F]FECUMI-101) as an imaging probe for 5-HT1A receptor agonist in nonhuman primates  

PubMed Central

The 5-HT1AR partial agonist PET radiotracer, [11C]CUMI-101, has advantages over an antagonist radiotracer as it binds preferentially to the high affinity state of the receptor and thereby provides more functionally meaningful information. The major drawback of C-11 tracers is the lack of cyclotron facility in many health care centers thereby limiting widespread clinical or research use. We identified the fluoroethyl derivative, 2-(4-(4-(2-(2-fluoroethoxy)phenyl)piperazin-1-yl)butyl)-4-methyl-1,2,4-triazine-3,5(2H,4H)dione (FECUMI-101) (Ki = 0.1 nM; Emax = 77%; EC50 = 0.65 nM) as a partial agonist 5-HT1AR ligand of the parent ligand CUMI-101. FECUMI-101 is radiolabeled with F-18 by O-fluoroethylation of the corresponding desmethyl analogue (1) with [18F]fluoroethyltosylate in DMSO in the presence of 1.6 equiv. of K2CO3 in 45 ± 5% yield (EOS). PET shows [18F]FECUMI-101 binds specifically to 5-HT1AR enriched brain regions of baboon. The specificity of [18F]FECUMI-101 binding to 5-HT1AR was confirmed by challenge studies with the known 5-HT1AR ligand WAY100,635. These findings indicate that [18F]FECUMI-101 can be a viable agonist ligand for the in vivo quantification of high affinity 5-HT1AR with PET. PMID:23816046

Majo, Vattoly J.; Milak, Matthew S.; Prabhakaran, Jaya; Mali, Pratap; Savenkova, Lyudmila; Simpson, Norman R.; Mann, J. John; Parsey, Ramin V.; Dileep Kumar, J. S.

2013-01-01

188

Micelles of enzymatically synthesized PEG-poly(amine-co-ester) block copolymers as pH-responsive nanocarriers for docetaxel delivery.  

PubMed

A series of PEGylated poly(amine-co-ester) terpolymers were successfully synthesized in one step via lipase-catalyzed copolymerization of ?-pentadecalactone (PDL), diethyl sebacate (DES), and N-methyldiethanolamine (MDEA) comonomers in the presence of poly(ethylene glycol) methyl ether as a chain-terminating agent. The resultant amphiphilic poly(ethylene glycol)-poly(PDL-co-MDEA-co-sebacate) (PEG-PPMS) block copolymers consisted of hydrophilic PEG chain segments and hydrophobic random PPMS chain segments, which self-assembled in aqueous medium to form stable, nanosized micelles at physiological pH of 7.4. Upon decreasing the medium pH from 7.4 to 5.0, the copolymer micelles swell significantly due to protonation of the amino groups in the micelle PPMS cores. Correspondingly, docetaxel (DTX)-encapsulated PEG2K-PPMS copolymer micelles showed gradual sustained drug release at pH of 7.4, but remarkably accelerated DTX release at acidic pH of 5.0. The drug-loaded micelle particles were readily internalized by SK-BR-3 cancer cells and, compared to free DTX drug, DTX-loaded micelles of the copolymers with optimal compositions exhibited enhanced potency against the cells. Biodegradable PEG-PPMS copolymer micelles represent a new type of promising, pH-responsive nanocarriers for anticancer drug delivery, and the drug release rate from the micelles can be systematically controlled by both pH and the copolymer composition. PMID:24398083

Zhang, Xiaofang; Liu, Bo; Yang, Zhe; Zhang, Chao; Li, Hao; Luo, Xingen; Luo, Huiyan; Gao, Di; Jiang, Qing; Liu, Jie; Jiang, Zhaozhong

2014-03-01

189

Accelerated field facility development for hot sour gas  

SciTech Connect

This paper presents the chronological plan by which a grass roots sweetening facility was constructed in a minimum amount of time. The facility design was based on production with 9% carbon dioxide and 40 ppm hydrogen sulfide. Flowing wellhead temperatures were predicted to be approximately 300/sup 0/F with flowing wellhead pressures to 11,500 psi. The production facility, with a current total nominal capacity of 100 MMcf/D, was installed as five separate parallel sweetening units. The units were put on-stream in phases in order to maintain a sweetening capacity schedule compatible with wells being put on production. The first units were available for service in three months. All five units were complete in nine months, and a permanent facility installation was commissioned three months later. The process design, equipment procurement, and installation phases of the project were pursued concurrently. Three different sweetening systems were operated during the facility development. A conventional DEA (diethanolamine) system was used because of its simple operation. Conversions were made to a proprietary MDEA (methyldiethanolamine) system in order to increase capacity. A proprietary activated MDEA was tested and operated in order to determine sweetening system selection for future facility capacity and for other applications. Included is a discussion of the project development procedure and key considerations that led to minimal development time. General comparisons are made concerning the performance of several sweetening systems.

Kuntz, L.K.

1983-10-01

190

21 CFR 520.2380f - Thiabendazole, piperazine phosphate powder.  

Code of Federal Regulations, 2010 CFR

...body weight. (2) Indications for use. Treatment of infections of large strongyles (genus Strongylus ), small strongyles...Poteriostomum ), pinworms (Oxyuris ), threadworms (Strongyloides ), and ascarids (Parascaris ) in horses. (3)...

2010-04-01

191

21 CFR 520.1803 - Piperazine citrate capsules.  

Code of Federal Regulations, 2013 CFR

...c) of this chapter. (c) Conditions of use. (1) It is used in dogs and cats for the removal of large roundworms (Toxocara canis and Toxascaris leonina ). (2) The contents of 1 capsule should be mixed with the food of the animal...

2013-04-01

192

21 CFR 520.1803 - Piperazine citrate capsules.  

...c) of this chapter. (c) Conditions of use. (1) It is used in dogs and cats for the removal of large roundworms (Toxocara canis and Toxascaris leonina ). (2) The contents of 1 capsule should be mixed with the food of the animal...

2014-04-01

193

21 CFR 520.1803 - Piperazine citrate capsules.  

Code of Federal Regulations, 2011 CFR

...c) of this chapter. (c) Conditions of use. (1) It is used in dogs and cats for the removal of large roundworms (Toxocara canis and Toxascaris leonina ). (2) The contents of 1 capsule should be mixed with the food of the animal...

2011-04-01

194

21 CFR 520.1803 - Piperazine citrate capsules.  

Code of Federal Regulations, 2012 CFR

...c) of this chapter. (c) Conditions of use. (1) It is used in dogs and cats for the removal of large roundworms (Toxocara canis and Toxascaris leonina ). (2) The contents of 1 capsule should be mixed with the food of the animal...

2012-04-01

195

21 CFR 520.1803 - Piperazine citrate capsules.  

Code of Federal Regulations, 2010 CFR

...c) of this chapter. (c) Conditions of use. (1) It is used in dogs and cats for the removal of large roundworms (Toxocara canis and Toxascaris leonina ). (2) The contents of 1 capsule should be mixed with the food of the animal...

2010-04-01

196

Development of an analytical technique and construction of an apparatus to study the reaction between carbon dioxide and methyldiethanolamine  

E-print Network

was designed to simulate a single tray in an absorption column. The contactor was operated isothermally with continuous flows for both the gas and arnica solutions. In the contactor, the gas was sparged through the amine solution using a fritted plate... limited due, in part, to the difficulty in measuring the acid gas concentration of aqueous arnica solutions. The first objective involved the development of a gas chromatographic (GC) method for analysing the CO content of aqueous NDEA solutions...

Robbins, Gary Don

2012-06-07

197

A liquid chromatography-electrospray ionization-tandem mass spectrometry study of ethanolamines in high salinity industrial wastewaters.  

PubMed

The detection and quantitation of four ethanolamines, tris(2-hydroxyethyl)amine (triethanolamine, TEA), N,N-bis(2-hydroxyethyl)methylamine (methyldiethanolamine, MDEA), N-(2-aminoethyl)ethanolamine (AEA), and N,N-diethylethanolamine (DEA), were achieved in wastewaters from two aerobic activated sludge bioreactors located in an industrial wastewater treatment plant. The streams had salt concentrations of approximately 3% and 7% by weight in Reactor 1 and Reactor 2, respectively. The use of liquid chromatography-electrospray ionization-tandem mass spectrometry avoided the need for some sample preparation steps such as extraction, concentration, and derivatization. Ion suppression in the electrospray, attributable to the presence of sodium clusters, was attenuated by a 10-fold dilution of the wastewaters with acetonitrile. A matrix-matched calibration model averted other potential interferences. For the compounds analyzed in selected reaction monitoring mode (TEA, MDEA, and DEA), the calibration curves presented linearity in a range of 10-1000microg/L with corresponding detection limits ranging from 2 to 11microg/L, depending upon the specific analyte and aqueous matrix. AEA was calibrated in selected ion monitoring mode (100-1000microg/L), with corresponding detection limits in the two wastewaters of 74.6 and 85.3microg/L, respectively. Overall good precision (<10%) and accuracy (97-110%) were achieved for both matrices, which fell within-laboratory reproducibility. Finally, the amines were introduced into six mixed liquor samples from both reactors and quantified following the reported protocol. Again, recoveries were close to 100% with a relative standard deviation of less than 10% in all cases. PMID:20006060

Campo, Pablo; Suidan, Makram T; Chai, Yunzhou; Davis, John

2010-01-15

198

A model of vapor-liquid equilibria for acid gas-alkanolamine-water systems  

SciTech Connect

A physico-chemical model was developed for representing liquid phase chemical equilibria and vapor-liquid (phase) equilibria of H{sub 2}SCO{sub 2}-alkanolamine-water systems. The equilibrium composition of the liquid phase is determined by minimization of the Gibbs free energy. Activity coefficients are represented with the Electrolyte-NRTL equation treating both long-range electrostatic interactions and short-range binary interactions between liquid phase species. Vapor phase fugacity coefficients are calculated using the Redlich-Kwong-Soave Equation of State. Adjustable parameters of the model, binary interaction parameters and carbamate stability constants, were fitted on published binary system alkanolamine-water and ternary system (H{sub 2}S-alkanolamine-water, CO{sub 2}-alkanolamine-water) VLE data. The Data Regression System of ASPEN PLUS, based upon the Maximum Likelihood Principle, was used to estimate adjustable parameters. Ternary system measurements used in parameter estimation ranged in temperature from 25 to 120{degree}C in alkanolamine concentration from 1 to 5 M, in acid gas loading from 0 to 1.5 moles per mole alkanolamine, and in acid gas partial pressure from 0.1 to 1,000 kPa. Maximum likelihood estimates of ternary system H{sub 2} or CO{sub 2} equilibrium partial pressures and liquid phase concentrations were found to be in good agreement with measurements for aqueous solutions of monoethanolamine (MEA), diethanolamine (DEA), diglycolamine (DGA), and methyldiethanolamine (MDEA) indicating that the model successfully represents ternary system data. The model was extended to represent CO{sub 2} solubility in aqueous mixtures of MDEA with MEA or DEA. The solubility was measured at 40 and 80{degree}C over a wide range of CO{sub 2} partial pressures. These measurements were used to estimate additional binary parameters of the mixed solvent systems.

Austgen, D.M. Jr.

1989-01-01

199

75 FR 41488 - Agency Information Collection Activities: Submission for OMB Review; Comment Request  

Federal Register 2010, 2011, 2012, 2013

...methylenedioxymethamphetamine (MDMA), commonly known as ``ecstasy''; methyleneamphetamine (MDA), and methylenedioxyethylamphetamine (MDEA). MDA and MDEA are both close chemical analogues of MDMA. The fourth change is to revise the...

2010-07-16

200

[Removal of CO2 from simulated flue gas of power plants by membrane-based gas absorption processes].  

PubMed

Three typical absorbents such as aqueous of aminoacetic acid potassium (AAAP), monoethanolamine (MEA) and methyldiethanolamine(MDEA) are selected to investigate the performance of CO2 separation from flue gas via membrane contactors made of hydrophobic hollow fiber polypropylene porous membrane. Impacts of absorbents, concentrations and flow rates of feeding gas and absorbent solution, cyclic loading of CO2 on the removal rate and the mass transfer velocity of CO2 are discussed. The results demonstrate that the mass transfer velocity was 7.1 mol x (m2 x s)(-1) for 1 mol x L(-1) MEA with flow rate of 0.1 m x s(-1) and flue gas with that of 0.211 m x s(-1). For 1 mol L(-1) AAAP with flow rate of 0.05 m x s(-1) and flue gas of 0.211 m x s(-1), CO2 removal rate (eta) was 93.2 % and eta was 98% for 4 mol x L(-1) AAAP under the same conditions. AAAP being absorbent, eta was higher than 90% in a wider range of concentrations of CO2. It indicates that membrane-based absorption process is a widely-applied and promising way of CO2 removal from flue gas of power plants, which not only appropriates for CO2 removal of flue gas of widely-used PF and NGCC, but also for that of flue gas of IGCC can be utilized widely in future. PMID:16212162

Yang, Ming-Fen; Fang, Meng-Xiang; Zhang, Wei-Feng; Wang, Shu-Yuan; Xu, Zhi-Kang; Luo, Zhong-Yang; Cen, Ke-Fa

2005-07-01

201

Diffusion coefficients of several aqueous alkanolamine solutions  

SciTech Connect

In absorption processes of acid gases (H[sub 2]S, CO[sub 2], COS) in alkanolamine solutions, diffusion coefficients are used for the calculation of the mass transfer rate. The Taylor dispersion technique was applied for the determination of diffusion coefficients of various systems. Experiments with the system KCl in water showed that the experimental setup provides accurate data. For the alkanolamines monoethanolamine (MEA), diethanolamine (DEA), methyldiethanolamine (MDEA), and di-2-propanolamine (DIPA), correlations for the diffusion coefficient as a function of temperature at different concentrations are given. A single relation for every amine has been derived which correlates the diffusion coefficients as a function of temperature and concentration. The temperature was varied between 298 and 348 K, and the concentration between 0 and 4000-5000 mol/m[sup 3]. Furthermore, a modified Stokes-Einstein relation is presented for the prediction of the diffusion coefficients in the alkanolamines in relation to the viscosity of the solvent and the diffusion coefficient at infinite dilution. The diffusion coefficients at low concentrations are compared with some available relations for the estimation of diffusion coefficients at infinite dilution, and it appears that the agreement is fairly good.

Snijder, E.D.; Riele, M.J.M. te; Versteeg, G.F.; Swaaij, W.P.M. van (Twente Univ. of Technology, Enschede (Netherlands). Dept. of Chemical Engineering)

1993-07-01

202

Novel tacrine/acridine anticholinesterase inhibitors with piperazine and thiourea linkers.  

PubMed

A new series of substituted tacrine/acridine and tacrine/tacrine dimers with aliphatic or alkylene-thiourea linkers was synthesized and the potential of these compounds as novel human acetylcholinesterase (hAChE) and human butyrylcholinesterase (hBChE) inhibitors with nanomolar inhibition activity was evaluated. The most potent AChE inhibitor was found to be homodimeric tacrine derivative 14a, which demonstrated an IC50 value of 2 nM; this value indicates an activity rate which is 250-times higher than that of tacrine 1 and 7500-times higher than 7-MEOTA 15, the compounds which were used as standards in the study. IC50 values of derivatives 1, 9, 10, 14b and 15 were compared with the dissociation constants of the enzyme-inhibitor complex, Ki1, and the enzyme-substrate-inhibitor complex, Ki2, for. A dual binding site is presumed for the synthesized compounds which possess two tacrines or tacrine and acridine as terminal moieties show evidence of dual site binding. DFT calculations of theoretical desolvation free energies, ??Gtheor, and docking studies elucidate these suggestions in more detail. PMID:25036600

Hamulakova, Slavka; Imrich, Jan; Janovec, Ladislav; Kristian, Pavol; Danihel, Ivan; Holas, Ondrej; Pohanka, Miroslav; Böhm, Stanislav; Kozurkova, Maria; Kuca, Kamil

2014-09-01

203

4-(Pyrimidin-2-yl)piperazin-1-ium (E)-3-carb­oxy­prop-2-enoate  

PubMed Central

In the cation of the title salt, C8H13N4 +·C4H3O4 ?, the piperazinium ring adopts a slightly distorteded chair conformation. In the crystal, a single strong O—H?O inter­molecular hydrogen bond links the anions, forming chains along the c-axis direction. The chains of anions are linked by the cations, via N—H?O hydrogen bonds, forming sheets parallel to (100). These layers are linked by weak C—H?O hydrogen bonds, forming a three-dimensional structure. In addition, there are weak ?–? inter­actions [centroid–centroid distance = 3.820?(9)?Å] present involving inversion-related pyrimidine rings. PMID:24940275

Yamuna, Thammarse S.; Kaur, Manpreet; Jasinski, Jerry P.; Yathirajan, H. S.

2014-01-01

204

Interaction of organotin with piperazine derived self-assembled cylindrical bisdithiocarbamates: Spectral and thermal investigations  

NASA Astrophysics Data System (ADS)

Few organotin complexes of the type R 4Sn 2L 2 where R = CH 3 ( 2), C 4H 9 ( 3), C 6H 5 ( 4), and Sn 2L 2Cl 4 ( 5) (L = bis(2,2'-dithiopiperazinato-2,2'-diaminodiethylamine)) have been synthesized and suitably characterized by FT-IR, UV-vis, 1H NMR, 119Sn NMR, ESI-MS, TGA/DSC, microanalysis and room temperature molar conductivity data. On the basis of FT-IR spectral studies, a symmetrical bidentate coordination has been proposed for all the complexes while the absence of any higher peak in the ESI-MS may be corroborated with the formation of binuclear complexes. On the basis of 119Sn NMR spectroscopy, six-coordinate geometry has been observed for the Sn-center in all the complexes. The TGA/DSC profile of the complexes implies their higher stability than its precursor. However, on the basis of IDT values the stability order of the organotin complexes was found to be 4 > 3 > 2. The room temperature conductivity values of the 1 mM solution of the ligand and its complexes are found to be comparable with that of non-ionic complexes.

Husain, Ahmad; Nami, Shahab A. A.; Siddiqi, K. S.

2009-07-01

205

Discovery of 1-aryloxyethyl piperazine derivatives as Kv1.5 potassium channel inhibitors (part I).  

PubMed

Kv1.5 potassium channel is an efficacious and safe therapeutic target for the treatment of atrial fibrillation (AF), the most common arrhythmia that threatens human. Herein, by modifying the hit compound 7k from an in-house database, 48 derivatives were synthesized for the assay of their Kv1.5 inhibitory effects by whole cell patch clamp technique. Six compounds which showed better potency than the positive compound dronedarone were selected for the next evaluation of their drug-like properties. Compound 8 exhibited balanced solubility and permeability. It also showed acceptable pharmacodynamics profile with very low acute toxicity. Taking all these data into account, compound 8 can serve as a promising lead for the development of novel therapeutic agent for the treatment of AF. PMID:24824064

Guo, Xiaoke; Ma, Xianglei; Yang, Qian; Xu, Jing; Huang, Lu; Jia, Jianmin; Shan, Jiaojiao; Liu, Li; Chen, Weilin; Chu, Hongxi; Wei, Jinlian; Zhang, Xiaojin; Sun, Haopeng; Tang, Yiqun; You, Qidong

2014-06-23

206

Discovery of potent furan piperazine sodium channel blockers for treatment of neuropathic pain  

Microsoft Academic Search

The synthesis and pharmacological characterization of a novel furan-based class of voltage-gated sodium channel blockers is reported. Compounds were evaluated for their ability to block the tetrodotoxin-resistant sodium channel Nav1.8 (PN3) as well as the Nav1.2 and Nav1.5 subtypes. Benchmark compounds from this series possessed enhanced potency, oral bioavailability, and robust efficacy in a rodent model of neuropathic pain, together

Irene Drizin; Robert J. Gregg; Marc J. C. Scanio; Lei Shi; Michael F. Gross; Robert N. Atkinson; James B. Thomas; Matthew S. Johnson; William A. Carroll; Brian E. Marron; Mark L. Chapman; Dong Liu; Michael J. Krambis; Char-Chang Shieh; XuFeng Zhang; Gricelda Hernandez; Donna M. Gauvin; Joseph P. Mikusa; Chang Z. Zhu; Shailen Joshi; Prisca Honore; Kennan C. Marsh; Rosemarie Roeloffs; Stephen Werness; Douglas S. Krafte; Michael F. Jarvis; Connie R. Faltynek; Michael E. Kort

2008-01-01

207

21 CFR 520.1802b - Piperazine-carbon disulfide complex boluses.  

Code of Federal Regulations, 2011 CFR

...Do not administer to animals that are or were recently affected with colic, diarrhea, or infected with a serious infectious disease. As with most anthelmintics, drastic cathartics or other gastrointestinal irritants should not be...

2011-04-01

208

21 CFR 520.1802a - Piperazine-carbon disulfide complex suspension.  

...Do not administer to animals that are or were recently affected with colic, diarrhea, or infected with a serious infectious disease. As with most anthelmintics, drastic cathartics and other gastrointestinal irritants should not be...

2014-04-01

209

21 CFR 520.1802b - Piperazine-carbon disulfide complex boluses.  

Code of Federal Regulations, 2012 CFR

...Do not administer to animals that are or were recently affected with colic, diarrhea, or infected with a serious infectious disease. As with most anthelmintics, drastic cathartics or other gastrointestinal irritants should not be...

2012-04-01

210

21 CFR 520.1802b - Piperazine-carbon disulfide complex boluses.  

Code of Federal Regulations, 2013 CFR

...Do not administer to animals that are or were recently affected with colic, diarrhea, or infected with a serious infectious disease. As with most anthelmintics, drastic cathartics or other gastrointestinal irritants should not be...

2013-04-01

211

21 CFR 520.1802a - Piperazine-carbon disulfide complex suspension.  

Code of Federal Regulations, 2010 CFR

...Do not administer to animals that are or were recently affected with colic, diarrhea, or infected with a serious infectious disease. As with most anthelmintics, drastic cathartics and other gastrointestinal irritants should not be...

2010-04-01

212

21 CFR 520.1802a - Piperazine-carbon disulfide complex suspension.  

Code of Federal Regulations, 2013 CFR

...Do not administer to animals that are or were recently affected with colic, diarrhea, or infected with a serious infectious disease. As with most anthelmintics, drastic cathartics and other gastrointestinal irritants should not be...

2013-04-01

213

21 CFR 520.1802b - Piperazine-carbon disulfide complex boluses.  

...Do not administer to animals that are or were recently affected with colic, diarrhea, or infected with a serious infectious disease. As with most anthelmintics, drastic cathartics or other gastrointestinal irritants should not be...

2014-04-01

214

21 CFR 520.1802a - Piperazine-carbon disulfide complex suspension.  

Code of Federal Regulations, 2011 CFR

...Do not administer to animals that are or were recently affected with colic, diarrhea, or infected with a serious infectious disease. As with most anthelmintics, drastic cathartics and other gastrointestinal irritants should not be...

2011-04-01

215

21 CFR 520.1802b - Piperazine-carbon disulfide complex boluses.  

Code of Federal Regulations, 2010 CFR

...Do not administer to animals that are or were recently affected with colic, diarrhea, or infected with a serious infectious disease. As with most anthelmintics, drastic cathartics or other gastrointestinal irritants should not be...

2010-04-01

216

21 CFR 520.1802a - Piperazine-carbon disulfide complex suspension.  

Code of Federal Regulations, 2012 CFR

...Do not administer to animals that are or were recently affected with colic, diarrhea, or infected with a serious infectious disease. As with most anthelmintics, drastic cathartics and other gastrointestinal irritants should not be...

2012-04-01

217

40 CFR 721.10102 - Diphosphoric acid, compd. with piperazine (1:1).  

Code of Federal Regulations, 2010 CFR

...are: (i) Industrial, commercial, and consumer activities . Requirements as specified in § 721.80(j) (flame retardant). (ii) [Reserved] (b) Specific requirements . The provisions of subpart A of this part apply to...

2010-07-01

218

40 CFR 721.10102 - Diphosphoric acid, compd. with piperazine (1:1).  

Code of Federal Regulations, 2011 CFR

...are: (i) Industrial, commercial, and consumer activities . Requirements as specified in § 721.80(j) (flame retardant). (ii) [Reserved] (b) Specific requirements . The provisions of subpart A of this part apply to...

2011-07-01

219

40 CFR 721.10102 - Diphosphoric acid, compd. with piperazine (1:1).  

Code of Federal Regulations, 2013 CFR

...are: (i) Industrial, commercial, and consumer activities . Requirements as specified in § 721.80(j) (flame retardant). (ii) [Reserved] (b) Specific requirements . The provisions of subpart A of this part apply to...

2013-07-01

220

40 CFR 721.10102 - Diphosphoric acid, compd. with piperazine (1:1).  

...are: (i) Industrial, commercial, and consumer activities. Requirements as specified in § 721.80(j) (flame retardant). (ii) [Reserved] (b) Specific requirements. The provisions of subpart A of this part apply to...

2014-07-01

221

40 CFR 721.10102 - Diphosphoric acid, compd. with piperazine (1:1).  

Code of Federal Regulations, 2012 CFR

...are: (i) Industrial, commercial, and consumer activities . Requirements as specified in § 721.80(j) (flame retardant). (ii) [Reserved] (b) Specific requirements . The provisions of subpart A of this part apply to...

2012-07-01

222

Synthesis, molecular docking and biological evaluation of metronidazole derivatives containing piperazine skeleton as potential antibacterial agents.  

PubMed

Metronidazole has a broad-spectrum antibacterial activity. Hereby a series of novel metronidazole derivatives were designed and synthesized based on nitroimidazole scaffold in order to find some more potent antibacterial drugs. For these compounds which were reported for the first time, their antibacterial activities against Escherichia coli, Pseudomonas aeruginosa, Bacillus subtilis and Staphylococcus aureus were tested. These compounds showed good antibacterial activities against Gram-positive strains. Compound 4m represented the most potent antibacterial activity against S. aureus ATCC 25923 with MIC of 0.003 ?g/mL and it showed the most potent activity against S. aureus TyrRS with IC50 of 0.0024 ?M. Molecular docking of 4m into S. aureus tyrosyl-tRNA synthetase active site were also performed to determine the probable binding mode. PMID:24680059

Wang, She-Feng; Yin, Yong; Qiao, Fang; Wu, Xun; Sha, Shao; Zhang, Li; Zhu, Hai-Liang

2014-04-15

223

21 CFR 520.1805 - Piperazine phosphate with thenium closylate tablets.  

Code of Federal Regulations, 2013 CFR

...stage larvae) and adult hookworms (Ancylostoma caninum, A. braziliense, and Uncinaria stenocephala ) and ascarids (Toxocara canis ) from weaned pups and adult dogs. (3) Limitations. Do not use this product to treat dogs...

2013-04-01

224

21 CFR 520.1805 - Piperazine phosphate with thenium closylate tablets.  

Code of Federal Regulations, 2011 CFR

...stage larvae) and adult hookworms (Ancylostoma caninum, A. braziliense, and Uncinaria stenocephala ) and ascarids (Toxocara canis ) from weaned pups and adult dogs. (3) Limitations. Do not use this product to treat dogs...

2011-04-01

225

21 CFR 520.1805 - Piperazine phosphate with thenium closylate tablets.  

Code of Federal Regulations, 2012 CFR

...stage larvae) and adult hookworms (Ancylostoma caninum, A. braziliense, and Uncinaria stenocephala ) and ascarids (Toxocara canis ) from weaned pups and adult dogs. (3) Limitations. Do not use this product to treat dogs...

2012-04-01

226

21 CFR 520.1805 - Piperazine phosphate with thenium closylate tablets.  

...stage larvae) and adult hookworms (Ancylostoma caninum, A. braziliense, and Uncinaria stenocephala ) and ascarids (Toxocara canis ) from weaned pups and adult dogs. (3) Limitations. Do not use this product to treat dogs...

2014-04-01

227

21 CFR 520.1805 - Piperazine phosphate with thenium closylate tablets.  

Code of Federal Regulations, 2010 CFR

...stage larvae) and adult hookworms (Ancylostoma caninum, A. braziliense, and Uncinaria stenocephala ) and ascarids (Toxocara canis ) from weaned pups and adult dogs. (3) Limitations. Do not use this product to treat dogs...

2010-04-01

228

A Novel Substituted Piperazine, CM156, Attenuates the Stimulant and Toxic Effects of Cocaine in Mice  

PubMed Central

Cocaine is a highly abused drug without effective pharmacotherapies to treat it. It interacts with sigma (?) receptors, providing logical targets for the development of medications to counteract its actions. Cocaine causes toxic and stimulant effects that can be categorized as acute effects such as convulsions and locomotor hyperactivity and subchronic effects including sensitization and place conditioning. In the present study, 3-(4-(4-cyclohexylpiperazin-1-yl)butyl)benzo[d]thiazole-2(3H)-thione (CM156), a novel compound, was developed and tested for interactions with ? receptors using radioligand binding studies. It was also evaluated against cocaine-induced effects in behavioral studies. The results showed that CM156 has nanomolar affinities for each of the ? receptor subtypes in the brain and much weaker affinities for non-? binding sites. Pretreatment of male Swiss-Webster mice with CM156, before administering either a convulsive or locomotor stimulant dose of cocaine, led to a significant attenuation of these acute effects. CM156 also significantly reduced the expression of behavioral sensitization and place conditioning evoked by subchronic exposure to cocaine. The protective effects of CM156 are consistent with ? receptor-mediated actions. Together with previously reported findings, the data from CM156 and related ? compounds indicate that ? receptors can be targeted to alleviate deleterious actions of cocaine. PMID:20100904

Xu, Yan-Tong; Kaushal, Nidhi; Shaikh, Jamaluddin; Wilson, Lisa L.; Mésangeau, Christophe; McCurdy, Christopher R.

2010-01-01

229

Synthesis and biological investigation of coumarin piperazine (piperidine) derivatives as potential multireceptor atypical antipsychotics.  

PubMed

The discovery and synthesis of potential and novel antipsychotic coumarin derivatives, associated with potent dopamine D2, D3, and serotonin 5-HT1A and 5-HT2A receptor properties, are the focus of the present article. The most-promising derivative was 7-(4-(4-(6-fluorobenzo[d]isoxazol-3-yl)-piperidin-1-yl)butoxy)-4-methyl-8-chloro-2H-chromen-2-one (17m). This derivative possesses unique pharmacological features, including high affinity for dopamine D2 and D3 and serotonin 5-HT1A and 5-HT2A receptors. Moreover, it possesses low affinity for 5-HT2C and H1 receptors (to reduce the risk of obesity associated with chronic treatment) and hERG channels (to reduce the incidence of torsade des pointes). In animal models, compound 17m inhibited apomorphine-induced climbing behavior, MK-801-induced hyperactivity, and the conditioned avoidance response without observable catalepsy at the highest dose tested. Further, fewer preclinical adverse events were noted with 17m compared with risperidone in assays that measured prolactin secretion and weight gain. Acceptable pharmacokinetic properties were also noted with 17m. Taken together, 17m may constitute a novel class of drugs for the treatment of schizophrenia. PMID:23675993

Chen, Yin; Wang, Songlin; Xu, Xiangqing; Liu, Xin; Yu, Minquan; Zhao, Song; Liu, Shicheng; Qiu, Yinli; Zhang, Tan; Liu, Bi-Feng; Zhang, Guisen

2013-06-13

230

Wipe selection for the analysis of surface materials containing chemical warfare agent nitrogen mustard degradation products by ultra-high pressure liquid chromatography-tandem mass spectrometry.  

PubMed

Degradation products arising from nitrogen mustard chemical warfare agent were deposited on common urban surfaces and determined via surface wiping, wipe extraction, and liquid chromatography–tandem mass spectrometry detection. Wipes investigated included cotton gauze, glass fiber filter, non-woven polyester fiber and filter paper, and surfaces included several porous (vinyl tile, painted drywall, wood) and mostly non-porous (laminate, galvanized steel, glass) surfaces. Wipe extracts were analyzed by ultra-high pressure liquid chromatography–tandem mass spectrometry (UPLC–MS/MS) and compared with high performance liquid chromatography–tandem mass spectrometry (HPLC–MS/MS) results. An evaluation of both techniques suggests UPLC–MS/MS provides a quick and sensitive analysis of targeted degradation products in addition to being nearly four times faster than a single HPLC run, allowing for greater throughput during a wide-spread release concerning large-scale contamination and subsequent remediation events. Based on the overall performance of all tested wipes, filter paper wipes were selected over other wipes because they did not contain interferences or native species (TEA and DEA) associated with the target analytes, resulting in high percent recoveries and low background levels during sample analysis. Other wipes, including cotton gauze, would require a pre-cleaning step due to the presence of large quantities of native species or interferences of the targeted analytes. Percent recoveries obtained from a laminate surface were 47–99% for all nitrogen mustard degradation products. The resulting detection limits achieved from wipes were 0.2 ng/cm(2) for triethanolamine (TEA), 0.03 ng/cm(2) for N-ethyldiethanolamine (EDEA), 0.1 ng/cm(2) for N-methyldiethanolamine (MDEA), and 0.1 ng/cm(2) for diethanolamine (DEA). PMID:23218189

Willison, Stuart A

2012-12-28

231

75 FR 59105 - Procedures for Transportation Workplace Drug and Alcohol Testing Programs: Federal Drug Testing...  

Federal Register 2010, 2011, 2012, 2013

...of the CCF, the new drug analytes MDMA, MDA, and MDEA are added, as are ``[Delta...confirmed positive drug test for MDMA, MDA, or MDEA, as appropriate, to the MRO...box--must write in the specific MDMA, MDA, or MDEA analyte in the...

2010-09-27

232

Synthesis and characterization of novel calix[4]arene piperazine derivative for the extraction of transition metals and dichromate ions  

Microsoft Academic Search

This article displays the synthesis of N-(2-tosylato)ethylpiperazine (ii) and 5,11,17,23-tetra-tert-butyl-25,27-bis-(2-piprazinoethyl)-26,28-dihydroxycalix[4]arene (3). Compounds (ii) and 3 were characterized through elemental analysis, FT-IR, 1H NMR and\\/or 13C NMR studies. The transition metal cations (Hg2+, Co2+, Ni2+, Cu2+, and Cd2+) and dichromate anion were studied by liquid–liquid extraction experiment. The results showed that compound 3 has moderate but selective extraction ability for Hg2+

Fozia Tabassum Minhas; Shahabuddin Memon; M. I. Bhanger

2010-01-01

233

Synthesis, growth, structural and optical studies of a novel organic Piperazine (bis) p-toluenesulfonate single crystal.  

PubMed

A novel organic single crystal of Piperazinium (bis) p-toluenesulfonate (PPTS) was grown by a slow evaporation solution growth technique. The structure of the grown crystal was determined using single crystal X-ray diffraction analysis. The PPTS crystal belongs to the triclinic crystal system with space group of P1¯. The presence of functional groups was confirmed by FTIR spectral analysis. The optical transmittance range and cut-off wavelength were identified by UV-vis-NIR spectral studies. The luminescent properties of PPTS crystal were investigated. The thermal behavior of PPTS crystal was studied by TG-DT analyses. PMID:25574648

Rekha, P; Peramaiyan, G; NizamMohideen, M; Mohan Kumar, R; Kanagadurai, R

2015-03-15

234

Single-molecule magnetism in a family of {Co(III)2Dy(III)2} butterfly complexes: effects of ligand replacement on the dynamics of magnetic relaxation.  

PubMed

The synthesis and structural characterization of four related heterometallic complexes of formulas [Dy(III)2Co(III)2(OMe)2(teaH)2(O2CPh)4(MeOH)4](NO3)2·MeOH·H2O (1a) and [Dy(III)2Co(III)2(OMe)2(teaH)2(O2CPh)4(MeOH)2(NO3)2]·MeOH·H2O (1b), [Dy(III)2Co(III)2(OMe)2(dea)2(O2CPh)4(MeOH)4](NO3)2 (2), [Dy(III)2Co(III)2(OMe)2(mdea)2(O2CPh)4(NO3)2] (3), and [Dy(III)2Co(III)2(OMe)2(bdea)2(O2CPh)4(MeOH)4](NO3)2·0.5MeOH·H2O (4a) and [Dy(III)2Co(III)2(OMe)2(bdea)2(O2CPh)4(MeOH)2(NO3)2]·MeOH·1.5H2O (4b) are reported (teaH3 = triethanolamine, deaH2 = diethanolamine, mdeaH2 = N-methyldiethanolamine, and bdeaH2 = N-n-butyldiethanolamine). Compounds 1 (? 1a and 1b) and 4 (? 4a and 4b) both display two unique molecules within the same crystal and all compounds display a butterfly type core, with the Dy(III) ions occupying the central body positions and the diamagnetic Co(III) ions the outer wing-tip sites. Compounds 1-4 were investigated via direct current and alternating current magnetic susceptibility measurements, and it was found that each complex displayed single-molecule magnet (SMM) behavior. All four compounds display unique coordination and geometric environments around the Dy(III) ions and it was found that each displays a different anisotropy barrier. Ab initio calculations were performed on 1-4 and these determined the low lying electronic structure of each Dy(III) ion and the magnetic interactions for each cluster. It was found that there was a strong correlation between the calculated energy gap between the ground and first excited states of the single-ion ligand-field split Dy(III) levels and the experimentally observed anisotropy barrier. Furthermore, the transverse g factors found for the Dy(III) ions, defining the tunnelling rates within the ground Kramers doublets, are largest for 1, which agrees with the experimental observation of the shortest relaxation time in the high-temperature domain for this complex. The magnetic exchange between the Dy(III) ions revealed overall antiferromagnetic interactions for each compound, derived from the dominant dipolar exchange resulting in nonmagnetic ground states for 1-4. The diamagnetic ground states coupled with small tunneling gaps resulted in quantum tunneling time scales at zero field of between 0.1 and >1.5 s. PMID:24749511

Langley, Stuart K; Ungur, Liviu; Chilton, Nicholas F; Moubaraki, Boujemaa; Chibotaru, Liviu F; Murray, Keith S

2014-05-01

235

49 CFR Appendix C to Part 40 - DOT Drug Testing Semi-Annual Laboratory Report to DOT  

Code of Federal Regulations, 2010 CFR

...e) Amphetamines (number) (1) Amphetamine (number) (2) Methamphetamine (number) (3) MDMA (number) (4) MDA (number) (5) MDEA (number) 5. Adulterated Results Reported (total number) By Reason (number) 6....

2010-10-01

236

49 CFR Appendix B to Part 40 - DOT Drug Testing Semi-Annual Laboratory Report to Employers  

Code of Federal Regulations, 2011 CFR

...e) Amphetamines (number) (1) Amphetamine (number) (2) Methamphetamine (number) (3) MDMA (number) (4) MDA (number) (5) MDEA (number) 5. Adulterated (number) 6. Substituted (number) 7. Invalid Result...

2011-10-01

237

49 CFR Appendix C to Part 40 - DOT Drug Testing Semi-Annual Laboratory Report to DOT  

Code of Federal Regulations, 2011 CFR

...e) Amphetamines (number) (1) Amphetamine (number) (2) Methamphetamine (number) (3) MDMA (number) (4) MDA (number) (5) MDEA (number) 5. Adulterated Results Reported (total number) By Reason (number) 6....

2011-10-01

238

49 CFR Appendix B to Part 40 - DOT Drug Testing Semi-Annual Laboratory Report to Employers  

Code of Federal Regulations, 2010 CFR

...e) Amphetamines (number) (1) Amphetamine (number) (2) Methamphetamine (number) (3) MDMA (number) (4) MDA (number) (5) MDEA (number) 5. Adulterated (number) 6. Substituted (number) 7. Invalid Result...

2010-10-01

239

49 CFR Appendix C to Part 40 - DOT Drug Testing Semi-Annual Laboratory Report to DOT  

Code of Federal Regulations, 2012 CFR

...e) Amphetamines (number) (1) Amphetamine (number) (2) Methamphetamine (number) (3) MDMA (number) (4) MDA (number) (5) MDEA (number) 5. Adulterated Results Reported (total number) By Reason (number) 6....

2012-10-01

240

49 CFR Appendix B to Part 40 - DOT Drug Testing Semi-Annual Laboratory Report to Employers  

Code of Federal Regulations, 2013 CFR

...e) Amphetamines (number) (1) Amphetamine (number) (2) Methamphetamine (number) (3) MDMA (number) (4) MDA (number) (5) MDEA (number) 5. Adulterated (number) 6. Substituted (number) 7. Invalid Result...

2013-10-01

241

49 CFR Appendix B to Part 40 - DOT Drug Testing Semi-Annual Laboratory Report to Employers  

Code of Federal Regulations, 2012 CFR

...e) Amphetamines (number) (1) Amphetamine (number) (2) Methamphetamine (number) (3) MDMA (number) (4) MDA (number) (5) MDEA (number) 5. Adulterated (number) 6. Substituted (number) 7. Invalid Result...

2012-10-01

242

49 CFR Appendix C to Part 40 - DOT Drug Testing Semi-Annual Laboratory Report to DOT  

Code of Federal Regulations, 2013 CFR

...e) Amphetamines (number) (1) Amphetamine (number) (2) Methamphetamine (number) (3) MDMA (number) (4) MDA (number) (5) MDEA (number) 5. Adulterated Results Reported (total number) By Reason (number) 6....

2013-10-01

243

77 FR 39737 - Controlled Substances: Proposed Adjustment to the Aggregate Production Quotas for 2012  

Federal Register 2010, 2011, 2012, 2013

...4-Methylenedioxy-N-ethylamphetamine (MDEA)...... 15 g......................... 24 g. 3,4-Methylenedioxymethamphetamine (MDMA).......... 22 g......................... 30 g. 3,4-Methylenedioxypyrovalerone...

2012-07-05

244

Synthesis and biological activity of some novel trifluoromethyl-substituted 1,2,4-triazole and bis(1,2,4-triazole) Mannich bases containing piperazine rings.  

PubMed

A series of trifluoromethyl-substituted 1,2,4-triazole Mannich base 6 and bis(1,2,4-triazole) Mannich base 7 containing pyrimidinylpiperazine rings via the Mannich reaction were synthesized and characterized by infrared (IR), (1)H nuclear magnetic resonance (NMR), and elemental analysis. The fungicidal tests indicated that most of compounds 6 and 7 possessed excellent fungicidal activity. Among 19 novel compounds, some showed superiority over commercial fungicides Dimethomorph, Thiophanate-methyl, Iprodione, and Zhongshengmycin. Some compounds also exhibited favorable herbicidal activity in the preliminary studies. On the basis of the comparative molecular field analysis (CoMFA), five novel compounds were subsequently synthesized, their activities were estimated fairly accurately, and compounds 6-A1 and 7-A2 displayed good fungicidal activity against Pseudoperonospora cubensis (96.9 and 84.9%) as 6h and 7c, respectively. PMID:20384340

Wang, Bao-Lei; Shi, Yan-Xia; Ma, Yi; Liu, Xing-Hai; Li, Yong-Hong; Song, Hai-Bin; Li, Bao-Ju; Li, Zheng-Ming

2010-05-12

245

Aminoalkoxo-supported heteroleptic hexanuclear gallium(III) wheel as a synthon for group 13 heterometallics: a rare sol-gel precursor for mixed Al-Ga oxide as support for gold catalysts.  

PubMed

A new heteroleptic gallium(III) complex, Ga(6)Cl(6)(mdea)(6) (1 x 2 CHCl(3)) (mdeaH(2) = N-methyl diethanolamine) was prepared in good yield by a chloro-aminoalkoxo exchange reaction and used as a synthon for the synthesis of a novel group 13 heterometallic derivative, Ga(2)Al(4)(O)(2)(mdea)(2)(OPr(i))(10) (2 x 2 CHCl(3)), the latter acting as a facile single source precursor for the sol-gel preparation of the mixed Al-Ga oxide as a high surface area support for gold catalysts. PMID:20625595

Mishra, Shashank; Jeanneau, Erwann; Daniele, Stéphane; Mendez, Violaine

2010-08-28

246

49 CFR 40.87 - What are the cutoff concentrations for drug tests?  

Code of Federal Regulations, 2011 CFR

...concentration equal to or greater than 100 ng/mL. 6 Methylenedioxymethamphetamine (MDMA). 7 Methylenedioxyamphetamine (MDA). 8 Methylenedioxyethylamphetamine (MDEA). (b) On an initial drug test, you must report a result below...

2011-10-01

247

49 CFR 40.87 - What are the cutoff concentrations for drug tests?  

Code of Federal Regulations, 2010 CFR

...concentration equal to or greater than 100 ng/mL. 6 Methylenedioxymethamphetamine (MDMA). 7 Methylenedioxyamphetamine (MDA). 8 Methylenedioxyethylamphetamine (MDEA). (b) On an initial drug test, you must report a result below...

2010-10-01

248

49 CFR 40.87 - What are the cutoff concentrations for drug tests?  

Code of Federal Regulations, 2012 CFR

...concentration equal to or greater than 100 ng/mL. 6 Methylenedioxymethamphetamine (MDMA). 7 Methylenedioxyamphetamine (MDA). 8 Methylenedioxyethylamphetamine (MDEA). (b) On an initial drug test, you must report a result below...

2012-10-01

249

49 CFR 40.87 - What are the cutoff concentrations for drug tests?  

Code of Federal Regulations, 2013 CFR

...concentration equal to or greater than 100 ng/mL. 6 Methylenedioxymethamphetamine (MDMA). 7 Methylenedioxyamphetamine (MDA). 8 Methylenedioxyethylamphetamine (MDEA). (b) On an initial drug test, you must report a result below...

2013-10-01

250

Universit degli Studi di Roma "La Sapienza" D.I.C.E.A. Dipartimento Ingegneria Civile, Edile e Ambientale  

E-print Network

RICERCA Cat. B tipologia II ­ SSD ICAR/20 + M-DEA/01 ­ Codice Bando 21/2013, PUBBLICATO IN DATA 29 per il colloquio orale, senza che vi sia pertanto altro obbligo di avviso. Ogni eventuale variazione

Guidoni, Leonardo

251

76 FR 56810 - Controlled Substances: 2011 Proposed Aggregate Production Quotas  

Federal Register 2010, 2011, 2012, 2013

...4-Methylenedioxy-N- 15 g No Change. ethylamphetamine (MDEA). 3,4-Methylenedioxymethamphetamine 22 g No Change. (MDMA). 3,4,5-Trimethoxyamphetamine........ 2 g No Change. 4-Bromo-2,5-dimethoxyamphetamine 2 g No...

2011-09-14

252

Carbonic anhydrase promotes the absorption rate of CO2 in post-combustion processes.  

PubMed

The rate of carbon dioxide (CO2) absorption by monoethanol amine (MEA), diethanol amine (DEA), N-methyl-2,2'-iminodiethanol (MDEA), and 2-amino-2-methyl 1-propanol (AMP) solutions was found to be enhanced by the addition of bovine carbonic anhydrase (CA), has been investigated using a vapor-liquid equilibrium (VLE) device. The enthalpy (-?Habs) of CO2 absorption and the absorption capacities of aqueous amines were measured in the presence and/or absence of CA enzyme via differential reaction calorimeter (DRC). The reaction temperature (?T) under adiabatic conditions was determined based on the DRC analysis. Bicarbonate and carbamate species formation mechanisms were elucidated by (1)H and (13)C NMR spectral analysis. The overall CO2 absorption rate (flux) and rate constant (kapp) followed the order MEA > DEA > AMP > MDEA in the absence or presence of CA. Hydration of CO2 by MDEA in the presence of CA directly produced bicarbonate, whereas AMP produced unstable carbamate intermediate, then underwent hydrolytic reaction and converted to bicarbonate. The MDEA > AMP > DEA > MEA reverse ordering of the enhanced CO2 flux and kapp in the presence of CA was due to bicarbonate formation by the tertiary and sterically hindered amines. Thus, CA increased the rate of CO2 absorption by MDEA by a factor of 3 relative to the rate of absorption by MDEA alone. The thermal effects suggested that CA yielded a higher activity at 40 °C. PMID:23621860

Vinoba, Mari; Bhagiyalakshmi, Margandan; Grace, Andrews Nirmala; Kim, Dae Hoon; Yoon, Yeoil; Nam, Sung Chan; Baek, Il Hyun; Jeong, Soon Kwan

2013-05-01

253

Evaluation of the genotoxic potential of alkylalkanolamines.  

PubMed

Three alkylalkanolamines, N,N-dimethylethanolamine, N-methyldiethanolamine, and tert-butyldiethanolamine, were evaluated for potential genotoxic activity using the Salmonella/microsome reverse gene mutation test, the CHO/HGPRT forward gene mutation test, a sister chromatid exchange test in cultured CHO cells, and an in vivo peripheral blood micronucleus test in Swiss-Webster mice. None of the three alkylalkanolamines produced any significant or dose-related increases in the frequencies of mutations, sister chromatid exchanges or micronuclei. These results indicate that N,N-dimethylethanolamine, N-methyldiethanolamine, and tert-butyldiethanolamine are not genotoxic in the tests conducted. PMID:9357557

Leung, H W; Ballantyne, B

1997-09-18

254

Design, Synthesis, and Pharmacological Evaluation of Novel 2-(4-substituted piperazin-1-yl)1, 8 Naphthyridine 3-Carboxylic Acids as 5-HT3 Receptor Antagonists for the Management of Depression.  

PubMed

1, 8-naphthyridine-3-carboxylic acid analogs were synthesized and found to possess potential 5-HT3 receptor antagonism as well as antidepressant-like activity. Initially, 5-HT3 receptor antagonism of all the compounds was determined in the form of pA2 value against agonist 2-methyl 5-HT in longitudinal muscle-myenteric plexus preparation from guinea-pig ileum. Among all the compounds tested, compound 7a demonstrated most promising pA2 value of 7.6. Subsequently, all the compounds were evaluated for antidepressant activity using forced swim test and tail suspension test in mice. Compounds 7a, 7d, 7f, 7h, and 7i exhibited significant (p < 0.05) antidepressant-like activity as compound to vehicle-treated group. Importantly, none of the tested compound affected locomotor activity of mice at tested dose levels. PMID:24903617

Dhar, Arghya K; Mahesh, Radhakrishnan; Jindal, Ankur; Devadoss, Thangaraj; Bhatt, Shvetank

2014-12-01

255

Variable dimensionality in the uranium fluoride/2-methyl-piperazine system: Synthesis and structures of UFO-5, -6, and -7; Zero-, one-, and two-dimensional materials with unprecedented topologies  

SciTech Connect

Recently, low temperature (T < 300 C) hydrothermal reactions of inorganic precursors in the presence of organic cations have proven highly productive for the synthesis of novel solid-state materials. Interest in these materials is driven by the astonishingly diverse range of structures produced, as well as by their many potential materials chemistry applications. This report describes the high yield, phase pure hydrothermal syntheses of three new uranium fluoride phases with unprecedented structure types. Through the systematic control of the synthesis conditions the authors have successfully controlled the architecture and dimensionality of the phase formed and selectively synthesized novel zero-, one-, and two-dimensional materials.

Francis, R.J.; Halasyamani, P.S.; Bee, J.S.; O'Hare, D.

1999-02-24

256

Synthesis and Evaluation of Anti-acetylcholinesterase Activity of 2-(2-(4-(2-Oxo-2-phenylethyl)piperazin-1-yl) ethyl)Isoindoline-1,3-dione Derivatives with Potential Anti-Alzheimer Effects  

PubMed Central

Objective(s): Alzheimer's disease (AD) is a neurodegenerative disorder in elderly patients. Decrease in cholinergic neurotransmission is the main known cause in the pathophysiology of the disease. Improvement and potentiation of the cholinergic system could be beneficial for treatment of the AD. Acetylcholinesterase inhibitors such as donepezil can enhance the duration of action of acetylcholine (Ach) and therefore, through this mechanism improve the symptoms of AD. Materials and Methods: In the current study, based on the potential inhibitory activity of phthalimide derivatives towards acetylcholinesterase enzyme, a new series of phthalimide-based compounds were synthesized (4a-4e) and anti-acetylcholinesterase effect was assessed using Ellman's test. Compound 4b with 4-Fluorophenyl moiety was the most potent derivative in this series (IC50 = 16.42 ± 1.07 µM). It was shown that, none of the synthesized compounds showed superior inhibitory potency compared to donepezil (0.41 ± 0.09 µM) as a reference drug. Conclusion: The new synthesized phthalimide based analogs could function as potential acetylcholinesterase inhibitors. Further studies are necessary for development of potent analogs. PMID:24379961

Aliabadi, Alireza; Foroumadi, Alireza; Mohammadi-Farani, Ahmad; Garmsiri Mahvar, Mahdi

2013-01-01

257

PAPER www.rsc.org/dalton | Dalton Transactions Structure and dimensionality of coordination complexes correlated to  

E-print Network

­organic frameworks (MOFs) based on coordination chemistry continues to be of great current interest to a variety studied of the hexadentate Schiff base ligand N,N¢-bis[2-{(salicylidenimine)amino}ethyl] piperazine (H2L of the reaction conditions or the presence of other co- ligands. In this regard, substituted piperazine-based

Li, Jing

258

Chukwuemeka I. Okoye Carbon Dioxide Solubility and Absorption Rate in  

E-print Network

Copyright by Chukwuemeka I. Okoye 2005 #12;Carbon Dioxide Solubility and Absorption Rate _______________________ Nicholas A. Peppas #12;Carbon Dioxide Solubility and Absorption Rate in Monoethanolamine/Piperazine/H2O for. #12;iii Carbon Dioxide Solubility and Absorption Rate in Monoethanolamine/Piperazine/H2O

Rochelle, Gary T.

259

Comparison of five derivatizing agents for the determination of amphetamine-type stimulants in human urine by extractive acylation and gas chromatography-mass spectrometry.  

PubMed

Five acylation reagents have been compared for use as derivatizing agents for the analysis of amphetamine-type stimulants (ATS) in urine by gas chromatography-mass spectrometry (GC-MS). The evaluated reagents were heptafluorobutyric anhydride, pentafluoropropionic anhydride, trifluoroacetic anhydride, acetic anhydride (AA) and N-methyl-bis(trifluoroacetamide). The ATS included amphetamine, methamphetamine (MA), 3,4-methylenedioxyamphetamine (MDA), 3,4-methylenedioxymethamphetamine (MDMA) and 3,4-methylenedioxyethylamphetamine (MDEA). A mixture of the ATS was added to urine (1 mL) followed by KOH solution and saturated NaHCO(3) solution. The sample was then extracted with dichloromethane and the derivatizing agent and 2 µL were injected into the GC-MS instrument. The derivatizing agents were compared with reference to the signal-to-noise (S/N) ratios, peak area values, relative standard deviations (RSDs), linearities, limits of detection (LODs) and selectivities. The acetic anhydride proved to be the best according to the S/N ratio and peak area results for amphetamine, MA, MDMA and MDEA. The best RSD values of peak areas and of S/N ratios at 3 µg/mL were also given by AA in cases of MDA, MDMA and MDEA. At 20 µg/mL, the lowest RSD values of peak areas for MDA and the lowest RSD values of S/N ratios for MA, MDA, MDMA and MDEA were again given by AA. Additionally, the highest correlation coefficients for MA, MDA, MDMA and MDEA and the lowest LOD results for MA, MDMA and MDEA were produced by AA. PMID:22582269

Dobos, Adrienn; Hidvégi, Elod; Somogyi, Gábor Pál

2012-06-01

260

Physiologically based pharmacokinetic modeling to predict drug-drug interactions involving inhibitory metabolite: a case study of amiodarone.  

PubMed

Evaluation of drug-drug interaction (DDI) involving circulating inhibitory metabolites of perpetrator drugs has recently drawn more attention from regulatory agencies and pharmaceutical companies. Here, using amiodarone (AMIO) as an example, we demonstrate the use of physiologically based pharmacokinetic (PBPK) modeling to assess how a potential inhibitory metabolite can contribute to clinically significant DDIs. Amiodarone was reported to increase the exposure of simvastatin, dextromethorphan, and warfarin by 1.2- to 2-fold, which was not expected based on its weak inhibition observed in vitro. The major circulating metabolite, mono-desethyl-amiodarone (MDEA), was later identified to have a more potent inhibitory effect. Using a combined "bottom-up" and "top-down" approach, a PBPK model was built to successfully simulate the pharmacokinetic profile of AMIO and MDEA, particularly their accumulation in plasma and liver after a long-term treatment. The clinical AMIO DDIs were predicted using the verified PBPK model with incorporation of cytochrome P450 inhibition from both AMIO and MDEA. The closest prediction was obtained for CYP3A (simvastatin) DDI when the competitive inhibition from both AMIO and MDEA was considered, for CYP2D6 (dextromethorphan) DDI when the competitive inhibition from AMIO and the competitive plus time-dependent inhibition from MDEA were incorporated, and for CYP2C9 (warfarin) DDI when the competitive plus time-dependent inhibition from AMIO and the competitive inhibition from MDEA were considered. The PBPK model with the ability to simulate DDI by considering dynamic change and accumulation of inhibitor (parent and metabolite) concentration in plasma and liver provides advantages in understanding the possible mechanism of clinical DDIs involving inhibitory metabolites. PMID:25324279

Chen, Yuan; Mao, Jialin; Hop, Cornelis E C A

2015-02-01

261

Z .Fluid Phase Equilibria 168 2000 241258 www.elsevier.nlrlocaterfluid  

E-print Network

in MDEA solutions neutralized with sulfuric acid. The physical solubility is seen to decrease absorption of acid gases by alkanolamines has found application in a wide variety of industries, including the processing of natural gas and the removal of CO from synthesis gas in the2 production of hydrogen or ammonia

Rochelle, Gary T.

262

21 CFR 1308.11 - Schedule I.  

Code of Federal Regulations, 2011 CFR

...N-ethyl-alpha-methyl-3,4(methylenedioxy)phenethylamine, N-ethyl MDA, MDE, MDEA 7404 (13) N-hydroxy-3,4-methylenedioxyamphetamine...N-hydroxy-alpha-methyl-3,4(methylenedioxy)phenethylamine, and N-hydroxy MDA 7402 (14) 3,4,5-trimethoxy amphetamine...

2011-04-01

263

49 CFR 40.151 - What are MROs prohibited from doing as part of the verification process?  

Code of Federal Regulations, 2011 CFR

...g) You must not accept an assertion that there is a legitimate medical explanation for the presence of PCP, 6-AM, MDMA, MDA, or MDEA in a specimen. (h) You must not accept, as a legitimate medical explanation for an adulterated specimen,...

2011-10-01

264

49 CFR 40.151 - What are MROs prohibited from doing as part of the verification process?  

Code of Federal Regulations, 2010 CFR

...g) You must not accept an assertion that there is a legitimate medical explanation for the presence of PCP, 6-AM, MDMA, MDA, or MDEA in a specimen. (h) You must not accept, as a legitimate medical explanation for an adulterated specimen,...

2010-10-01

265

21 CFR 1308.11 - Schedule I.  

Code of Federal Regulations, 2010 CFR

...N-ethyl-alpha-methyl-3,4(methylenedioxy)phenethylamine, N-ethyl MDA, MDE, MDEA 7404 (13) N-hydroxy-3,4-methylenedioxyamphetamine...N-hydroxy-alpha-methyl-3,4(methylenedioxy)phenethylamine, and N-hydroxy MDA 7402 (14) 3,4,5-trimethoxy amphetamine 7390...

2010-04-01

266

49 CFR 40.151 - What are MROs prohibited from doing as part of the verification process?  

Code of Federal Regulations, 2012 CFR

...g) You must not accept an assertion that there is a legitimate medical explanation for the presence of PCP, 6-AM, MDMA, MDA, or MDEA in a specimen. (h) You must not accept, as a legitimate medical explanation for an adulterated specimen,...

2012-10-01

267

21 CFR 1308.11 - Schedule I.  

...N-ethyl-alpha-methyl-3,4(methylenedioxy)-phenethylamine, N-ethyl MDA, MDE, MDEA 7404 (13) N-hydroxy-3,4-methylenedioxyamphetamine...N-hydroxy-alpha-methyl-3,4(methylenedioxy)-phenethylamine, and N-hydroxy MDA 7402 (14) 3,4,5-trimethoxy amphetamine...

2014-04-01

268

21 CFR 1308.11 - Schedule I.  

Code of Federal Regulations, 2012 CFR

...N-ethyl-alpha-methyl-3,4(methylenedioxy)phenethylamine, N-ethyl MDA, MDE, MDEA 7404 (13) N-hydroxy-3,4-methylenedioxyamphetamine...N-hydroxy-alpha-methyl-3,4(methylenedioxy)phenethylamine, and N-hydroxy MDA 7402 (14) 3,4,5-trimethoxy amphetamine...

2012-04-01

269

49 CFR 40.151 - What are MROs prohibited from doing as part of the verification process?  

Code of Federal Regulations, 2013 CFR

...g) You must not accept an assertion that there is a legitimate medical explanation for the presence of PCP, 6-AM, MDMA, MDA, or MDEA in a specimen. (h) You must not accept, as a legitimate medical explanation for an adulterated specimen,...

2013-10-01

270

21 CFR 1308.11 - Schedule I.  

Code of Federal Regulations, 2013 CFR

...N-ethyl-alpha-methyl-3,4(methylenedioxy)phenethylamine, N-ethyl MDA, MDE, MDEA 7404 (13) N-hydroxy-3,4-methylenedioxyamphetamine...N-hydroxy-alpha-methyl-3,4(methylenedioxy)phenethylamine, and N-hydroxy MDA 7402 (14) 3,4,5-trimethoxy amphetamine...

2013-04-01

271

Efficiency of an Integrated Gasification Combined Cycle (IGCC) power plant including CO 2 removal  

Microsoft Academic Search

This study is devoted to technical evaluation of a carbon dioxide removal in an existing Integrated Gasification Combined Cycle (IGCC) plant. This IGCC case is based on an oxygen blown entrained flow gasifier operating at 27bar, the removal of acid gas (H2S) is performed with MDEA unit, the efficiency of this IGCC is 43% based on the low heating value

C. Descamps; C. Bouallou; M. Kanniche

2008-01-01

272

Impaired cognitive performance in drug free users of recreational ecstasy (MDMA)  

Microsoft Academic Search

OBJECTIVESEcstasy (3,4-methylenedioxymethamphetamine (MDMA) and related congerers: MDA, MDEA) is the name given to a group of popular recreational drugs. Animal data raise concern about neurotoxic effects of high doses of ecstasy on central serotonergic systems. The threshold dose for neurotoxicity in humans is not clear and serotonin is involved in several functions including cognition. The purpose of this study was

Euphrosyne Gouzoulis-Mayfrank; Jörg Daumann; Frank Tuchtenhagen; Susanne Pelz; Steffanie Becker; Hans-Jürgen Kunert; Bruno Fimm; Henning Sass

2000-01-01

273

NATURAL GAS FIRED POWER CYCLES WITH INTEGRATED CO 2 CAPTURE  

Microsoft Academic Search

This paper examines two options with natural gas fired power cycles including carbon dioxide capture. One of these is about capturing carbon dioxide by absorption using the absorbent MDEA at elevated pressure integrated in the turbine of the gas turbine. The other option is stoichiometri c combustion with pure oxygen at high pressure in a modified Rankine type cycle -

Olav Bolland; Henriette Undrum; Michel Myhre-Nielsen

274

Cinnarizinium picrate  

PubMed Central

In the title salt {systematic name: 4-diphenyl­methyl-1-[(E)-3-phenyl­prop-2-en-1-yl]piperazin-1-ium 2,4,6-trinitro­pheno­late), C26H29N2 +·C6H2N3O7 ?, the cinnarizinium cation is protonated at the piperazine N atom connected to the styrenylmethyl group; the piperazine ring adopts a distorted chair conformaiton. In the crystal, bifurcated N—H?(O,O) hydrogen bonds link the components into two-ion aggregates. PMID:22719532

Song, Yanxi; Chidan Kumar, C. S.; Nethravathi, G. B.; Naveen, S.; Li, Hongqi

2012-01-01

275

Acidic gas capture by diamines  

DOEpatents

Compositions and methods related to the removal of acidic gas. In particular, the present disclosure relates to a composition and method for the removal of acidic gas from a gas mixture using a solvent comprising a diamine (e.g., piperazine) and carbon dioxide. One example of a method may involve a method for removing acidic gas comprising contacting a gas mixture having an acidic gas with a solvent, wherein the solvent comprises piperazine in an amount of from about 4 to about 20 moles/kg of water, and carbon dioxide in an amount of from about 0.3 to about 0.9 moles per mole of piperazine.

Rochelle, Gary (Austin, TX); Hilliard, Marcus (Missouri City, TX)

2011-05-10

276

The skin sensitization potential of four alkylalkanolamines.  

PubMed

The skin sensitization potential of 4 alkylalkanolamines (N-methylethanolamine, N,N-dimethylethanolamine, N-methyldiethanolamine and N,N-diethylethanolamine), was evaluated in a guinea pig maximation procedure by the method of Magnusson and Kligman. While all 4 alkylalkanolamines tested were irritating to the guinea pig skin, only N-methylethanolamine showed potential to induce allergic contact dermatitis. None of the remaining 3 alkylalkanolamines exhibited clear skin responses suggestive of sensitization. PMID:9554055

Leung, H W; Blaszcak, D L

1998-04-01

277

Comparative study on the regeneration of flue-gas desulfurizing agents by using conventional electrodialysis (ED) and bipolar membrane electrodialysis (BMED).  

PubMed

Piperazine is an ideal desulfurizing agent but the heat-stable salts formed in desulfurization have caused secondary pollution and waste of resources. In the previous paper, a method was reported to regenerate piperazine by using BMED. To find the variety of that regeneration process, we performed experiments on the regeneration of piperazine by using ED. In comparison, ED has higher piperazine yield and current efficiency, and much lower voltage drop and energy consumption. However, its process cost is higher than that of BMED due to an extra expenditure for the base and its tank and pumps. The process cost is estimated to be 0.96 dollar/kg Pz for BMED and 1.14 dollar/kg Pz for ED. Notably, BMED has more environmental benefits and will be more economically attractive as the control on secondary pollution is strengthened and the bipolar membrane cost decreases. PMID:16999135

Huang, Chuanhui; Xu, Tongwen

2006-09-01

278

Comparative study on the regeneration of flue-gas desulfurizing agents by using conventional electrodialysis (ED) and bipolar membrane electrodialysis (BMED)  

SciTech Connect

Piperazine (Pz) is an ideal desulfurizing agent but the heat-stable salts formed in desulfurization have caused secondary pollution and waste of resources. In the previous paper, a method was reported to regenerate piperazine by using bipolar membrane electrodialysis (BMED). To find the variety of that regeneration process, experiments were performed on the regeneration of piperazine by using ED. In comparison, ED has higher piperazine yield and current efficiency, and much lower voltage drop and energy consumption. However, its process cost is higher than that of BMED due to an extra expenditure for the base and its tank and pumps. The process cost is estimated to be 0.96 $/kg Pz for BMED and 1.14 $/kg Pz for ED. Notably, BMED has more environmental benefits and will be more economically attractive as the control on secondary pollution is strengthened and the bipolar membrane cost decreases. 9 refs., 4 figs., 1 tab.

Chuanhui Huang; Tongwen Xu [University of Science and Technology of China, Hefei (China). Laboratory of Functional Membranes, School of Chemistry and Material Science

2006-09-01

279

2-Methyl-piperazinediium tetra-chlorido-zincate(II).  

PubMed

The asymmetric unit of the title compound, (C(5)H(14)N(2))[ZnCl(4)], consists of a diprotonated 2-methyl-piperazine cation and a tetra-chloridozincate anion. The Zn(II) ion is in a slightly distorted tetra-hedral coordination environment. The six-membered piperazine ring adopts a chair conformation. The crystal structure is stabilized by inter-molecular N-H?Cl hydrogen bonds. PMID:21579012

Yin, Ming; Wu, Shao-Tong

2010-01-01

280

2-Methyl­piperazinediium tetra­chlorido­zincate(II)  

PubMed Central

The asymmetric unit of the title compound, (C5H14N2)[ZnCl4], consists of a diprotonated 2-methyl­piperazine cation and a tetra­chloridozincate anion. The ZnII ion is in a slightly distorted tetra­hedral coordination environment. The six-membered piperazine ring adopts a chair conformation. The crystal structure is stabilized by inter­molecular N—H?Cl hydrogen bonds. PMID:21579012

Yin, Ming; Wu, Shao-Tong

2010-01-01

281

Effect of selected anthelmintics on three common helminths in the brown pelican (Pelecanus occidentalis).  

PubMed

The effect of selected anthelmintics (albendazole, fenbendazole, piperazine dihydrochloride and clorsulon) against three major helminths (Contracaecum multipapillatum, Mesostephanus appendiculatoides, and Phagicola longus) were studied in 29 brown pelicans (Pelecanus occidentalis). Albendazole and fenbendazole were highly effective against all three parasites. Clorsulon had moderate effect against M. appendiculatoides and poor effect against C. multipapillatum and P. longus. Piperazine dihydrochloride had no effect against these helminths. PMID:2915399

Grimes, J; Suto, B; Greve, J H; Albers, H F

1989-01-01

282

Structural Modifications of Neuroprotective Anti-Parkinsonian (?)-N6-(2-(4-(Biphenyl-4-yl)piperazin-1-yl)-ethyl)-N6-propyl-4,5,6,7-tetrahydrobenzo[d]thiazole-2,6-diamine (D-264): An Effort toward the Improvement of in Vivo Efficacy of the Parent Molecule  

PubMed Central

In our overall goal to develop multifunctional dopamine D2/D3 agonist drugs for the treatment of Parkinson’s disease (PD), we previously synthesized potent D3 preferring agonist D-264 (1a), which exhibited neuroprotective properties in two animal models of PD. To enhance the in vivo efficacy of 1a, a structure–activity relationship study was carried out. Competitive binding and [35S]GTP?S functional assays identified compound (?)-9b as one of the lead molecules with preferential D3 agonist activity (EC50(GTP?S); D3 = 0.10 nM; D2/D3 (EC50): 159). Compounds (?)-9b and (?)-8b exhibited high in vivo activity in two PD animal models, reserpinized and 6-hydroxydopamine (OHDA)-induced unilateral lesioned rats. On the other hand, 1a failed to show any in vivo activity in these models unless the compound was dissolved in 5–10% beta-hydroxy propyl cyclodextrin solution. Lead compounds exhibited appreciable radical scavenging activity. In vitro experiments with dopaminergic MN9D cells indicated neuroprotection by both 1a and (?)-9b from toxicity of MPP+. PMID:24471976

2015-01-01

283

Bis[(2R,6S)-4-(5-amino-3-carb-oxy-1-cyclo-propyl-6,8-difluoro-4-oxo-1,4-dihydro-quinolin-7-yl)-2,6-dimethyl-piperazin-1-ium] sulfate penta-hydrate.  

PubMed

The title compound, C(19)H(23)F(2)N(4)O(3) (+)·0.5SO(4) (2-)·2.5H(2)O, an anti-bacterial fluoro-quinolone, crystallized as a racemic twin (major twin component = 0.633) in the chiral space group P1. The asymmetric unit contains two sparfloxacinium cations, one sulfate anion and five mol-ecules of water of solvation. The bond lengths and angles of both cations are almost identical. The quinoline ring systems in the cations are essentially planar, the mean deviations from the best plane being 0.045?(2) and 0.054?(2)?Å and make ?-? inter-actions with each other [centroid-centroid distances of 3.692?(4)?Å and 3.744?(4)?Å]. The crystal structure features inter-molecular O-H?O, O-H?S, N(+)-H?O, N(+)-H?S and N-H?O hydrogen bonds together with intra-molecular O-H?O and N-H?O hydrogen bonds. As a result, a three-dimensional supra-molecular structure is observed. PMID:22199860

Li, Tao; Yang, Lin; Wang, Yuan Cheng; Lian, Qiang

2011-12-01

284

Putative agmatinase inhibitor for hypoxic-ischemic new born brain damage.  

PubMed

Agmatine is an endogenous brain metabolite, decarboxylated arginine, which has neuroprotective properties when injected intraperitoneally (i.p.) into rat pups following hypoxic-ischemia. A previous screen for compounds based on rat brain lysates containing agmatinase with assistance from computational chemistry, led to piperazine-1-carboxamidine as a putative agmatinase inhibitor. Herein, the neuroprotective properties of piperazine-1-carboxamidine are described both in vitro and in vivo. Organotypic entorhinal-hippocampal slices were firstly prepared from 7-day-old rat pups and exposed in vitro to atmospheric oxygen depletion for 3 h. Upon reoxygenation, the slices were treated with piperazine-1-carboxamidine or agmatine (50 ?g/ml agents), or saline, and 15 h later propidium iodine was used to stain. Piperazine-1-carboxamidine or agmatine produced substantial in vitro protection compared to post-reoxygenated saline-treated controls. An in vivo model involved surgical right carotid ligation followed by exposure to hypoxic-ischemia (8 % oxygen) for 2.5 h. Piperazine-1-carboxamidine at 50 mg/kg i.p. was given 15 min post-reoxygenation and continued twice daily for 3 days. Cortical agmatine levels were elevated (+28.5 %) following piperazine-1-carboxamidine treatment with no change in arginine or its other major metabolites. Histologic staining with anti-Neun monoclonal antibody also revealed neuroprotection of CA1-3 layers of the hippocampus. Until endpoint at 22 days of age, no adverse events were observed in treated pups' body weights, rectal temperatures, or prompted ambulation. Piperazine-1-carboxamidine therefore appears to be a neuroprotective agent of a new category, agmatinase inhibitor. PMID:23334804

Piletz, John E; Klenotich, Stephanie; Lee, Ken S; Zhu, Qian Long; Valente, Edward; Collins, Michael A; Jones, Vyvyca; Lee, Soeb Nam; Yangzheng, Feng

2013-08-01

285

A study to investigate the performance of the Benfield-HiPure process of natural gas sweetening using computer simulations  

NASA Astrophysics Data System (ADS)

The removal of CO2 and H2S from natural gas is currently a global issue. Apart from meeting the customer's contract, pipeline, and LNG specifications; it is also a measure for reducing the global environmental emissions. The aim of this study is to investigate the performance of ADGAS' Train#3 plant through process simulations. ADGAS' Train#3 plant uses the Benfield HiPure design commissioned by Universal Oil Product (UOP Honeywell) in 1993. The Benfield HiPure process uses two independent but compatible circulating solutions in series to achieve high product purity in terms of acid gas concentrations that meet the LNG industry specifications. The ability to remove contaminants up to very low levels (1ppm H2S, 50ppm CO2 and 2ppm COS) makes the HiPure process an excellent choice for purifying natural gas for LNG requirement. At Das Island, ADGAS' Train#3 facility receives sour gas containing about 6-7 mole % acid gas content. This gas is first contacted with hot potassium carbonate (30wt% K2CO3) promoted with diethanolamine solution (3wt% DEA) followed by a contact with aqueous amine solution (20wt% DEA) alone as the second solvent. In this thesis, ADGAS Train#3 model was developed using the simulator tool ProMax®. Simulation outputs were found to match reasonably well the design and plant operating data. Based on the model predictions, the carbonate absorber seemed to be over designed with much of the acid gases being absorbed at the bottom of the packing. With the confidence that the model is a reliable replicate of the real plant facility, a parametric sensitivity analysis was carried out to develop a strategy of controlling operational uncertainties and enable plant optimization. The parametric sensitivity analysis showed that the liquid circulation rates, solvent concentrations, trim cooler temperatures, feed gas flow rate, and feed gas H2S/CO2 ratio have a considerable effect on the performance of the plant with respect to acid gas removal, gas production capacity and plant energy efficiency. Due to the complexity and high investment cost of the Benfield HiPure process, potential alternatives are evaluated. The alternatives are basically MDEA based solvents with promoters to enable the simultaneous removal of H 2S and CO2. BASF's MDEA, MDEA/DEA or MDEA/DGA processes seem to be the best alternatives to the Benfield HiPure process. Using MDEA/DEA or MDEA/DGA process will reduce the capital costs of ADGAS by 50% , and up to 48% will be saved on the annual power consumption (0.33 million dollars per years) . BASF's MDEA has slightly higher capital costs due to the additional units required on the high pressure flash and the quenching units used to generate the semi-lean solution. However, BASF's MDEA process still stands as one of the best alternatives with a savings of about 102 million dollars (48%) on the capital costs and up to 36% (3.96 USD per ton of acid gas removed) on the cost stripping.

Ochieng, Richard

286

Surface composition and protein adsorption of polyurethane membrane  

Microsoft Academic Search

Membranes of uncomplexed polyurethanes (PUs) were prepared by hydroxyl-terminated polybutadiene (HTPB), 4,4?-dicyclohexylmethane diisocyanate (H12MDI) and 1,4-butane diol (1,4-BD). While complexed PUs were prepared by using N-methyl diethanol (MDEA) as the chain extender of which the tertiary amines were complexed with cupric ions. Molar ratio of protein adsorption of fibrinogen to albumin (F\\/A molar ratio) on polymer surface was measured. The

Shih-Liang Huang; Cheng-Fang Ou; Juin-Yih Lai

1999-01-01

287

The first 4d/4f single-molecule magnet containing a {Ru(III)2Dy(III)2} core.  

PubMed

We report the synthesis, structure and magnetic properties of the first 4d-4f single-molecule magnet. The complex [Ru(III)2Dy(III)2(OMe)2(O2CPh)4(mdea)2(NO3)2] displays a butterfly type core, with an anisotropy barrier of 10.7 cm(-1). Ab initio and DFT calculations provide insight into the observed magnetic behaviour. PMID:25536910

Langley, Stuart K; Wielechowski, Daniel P; Vieru, Veacheslav; Chilton, Nicholas F; Moubaraki, Boujemaa; Chibotaru, Liviu F; Murray, Keith S

2015-02-01

288

Pathology of deaths associated with \\  

Microsoft Academic Search

AIMS: To study the postmortem pathology associated with ring substituted amphetamine (amphetamine derivatives) misuse. METHODS: The postmortem findings in deaths associated with the ring substituted amphetamines 3,4-methylenedioxymethyl-amphetamine (MDMA, ecstasy) and 3,4-methylenedioxyethylamphetamine (MDEA, eve) were studied in seven young white men aged between 20 and 25 years. RESULTS: Striking changes were identified in the liver, which varied from foci of individual

C M Milroy; J C Clark; A R Forrest

1996-01-01

289

Octanuclear Mn(III)6Mn(II)Ln (Ln = Gd, Dy and Er) clusters with a novel core topology: syntheses, structures, and magnetic properties.  

PubMed

Reactions of [Mn6O2(piv)10(py)2.5(piv)1.5], Ln(NO3)3·6H2O and N-mdeaH2 in MeCN in the presence of Me3SiCl generated a family of octanuclear Mn/Ln complexes [Mn6(III)Mn(II)Ln(N-mdea)3(N-mdeaH)(piv)8O2(OH)3(NO3)(H2O)]·xCH3CN·xH2O [Ln = Gd (1), Dy (2), Er (3), pivH = pivalic acid, N-mdeaH2 = N-methyl diethanolamine]. Each complex possesses a [Mn6(III)Mn(II)Ln(?3-O)2(?3-OH)3](16+) core containing two butterfly-like subunits of [Mn3Ln(?3-OH)2] and [Mn4(?3-O)2] sharing a common vertex, and an outer Mn atom ligated to one of the subunits through a ?3-OH(-) ligand. The core topology represents a new Mn/Ln core type. The magnetic susceptibility study of 1-3 indicates the presence of dominant antiferromagnetic interactions within the complexes. For complex 1, which contains an isotropic Gd(III) atom, fitting of the obtained M/(N?B) vs. H/T data gave S = 4, g = 1.90, and D = -0.31 cm(-1). The results were further supported by ac data. Complex exhibits out-of-phase ac susceptibility signals, indicating it may be a SMM. PMID:23377042

Chen, Hui; Ma, Cheng-Bing; Hu, Ming-Qiang; Wen, Hui-Min; Cui, Hong-Hua; Liu, Jin-Ying; Song, Xiao-Wei; Chen, Chang-Neng

2013-04-14

290

Comparative study of the heats of absorption of post-combustion CO 2 absorbents  

Microsoft Academic Search

Heats of absorption of CO2 with different solvents were measured in this work in a commercially available reaction calorimeter CPA-122 (Chemisens AS, Sweden) as function of temperature, loading and solvent composition over the temperature range from 40 to 120°C. Studied amines include primary amines (monoethanolamine and 2-amino-2-methyl-1-propanol), tertiary amines (N-methyldiethanolamine and N,N-diethylethanolamine), diamines (1-(2-aminoethyl)-aminoethanol and N-methyl-1,3-propanediamine), triamine (diethylenetriamine), and cyclic

Inna Kim; Hallvard F. Svendsen

2011-01-01

291

Excess molar enthalpies of (water + alkanolamine) systems and some thermodynamic calculations  

SciTech Connect

Several (water + alkanolamine) systems are used for removal of acidic gases such as carbon dioxide and hydrogen sulfide from gas streams in the natural gas and petroleum industries and are of increasing importance in treating streams in the chemical production industries. The authors have made calorimetric measurements of enthalpies of mixing of (water + monoethanolamine), (water + diethanolamine), and (water + triethanolamine) at T = 298.15 K and of (water + methyldiethanolamine) at T = 298.15 and 313.15 K. Results of these measurements have been used in some thermodynamic calculations to illustrate general principals that are applicable to many systems of mixed liquids.

Maham, Y.; Mather, A.E.; Hepler, L.G. [Univ. of Alberta, Edmonton, Alberta (Canada)] [Univ. of Alberta, Edmonton, Alberta (Canada)

1997-09-01

292

Rapid-screening detection of acetildenafils, sildenafils and avanafil by ion mobility spectrometry.  

PubMed

Ion mobility spectrometry was used as a rapid screening tool for the detection of acetildenafils, sildenafils and avanafil within adulterated herbal supplement matrices. Acetildenafils show a tendency for partial fragmentation during the desorption/ionization process affording two peaks in the ion mobility spectrum in addition to the intact compound. The fragmentation appears to occur ? to the carbonyl group along the CN bond attaching the piperazine moiety, producing a common fragment (K?=1.0280 cm²V?¹s?¹) along with the respective piperazine fragment. The sildenafils and avanafil afford one molecular ion peak per compound. PMID:23262416

Mans, Daniel J; Callahan, Rebecca J; Dunn, Jamie D; Gryniewicz-Ruzicka, Connie M

2013-03-01

293

Synthesis and functional survey of new Tacrine analogs modified with nitroxides or their precursors.  

PubMed

A series of new Tacrine analogs modified with nitroxides or pre-nitroxides on 9-amino group via methylene or piperazine spacers were synthesized; the nitroxide or its precursors were incorporated into the Tacrine scaffold. The new compounds were tested for their hydroxyl radical and peroxyl radical scavenging ability, acetylcholinesterase inhibitor activity and protection against A?-induced cytotoxicity. Based on these assays, we conclude that Tacrine analogs connected to five and six-membered nitroxides via piperazine spacers (9b, 9b/HCl and 12) exhibited the best activity, providing direction for further development of additional candidates with dual functionality (anti Alzheimer's and antioxidant). PMID:24657571

Kálai, Tamás; Altman, Robin; Maezawa, Izumi; Balog, Mária; Morisseau, Christophe; Petrlova, Jitka; Hammock, Bruce D; Jin, Lee-Way; Trudell, James R; Voss, John C; Hideg, Kálmán

2014-04-22

294

CO2 CAPTURE BY ABSORPTION WITH POTASSIUM CARBONATE  

SciTech Connect

The objective of this work is to improve the process for CO{sub 2} capture by alkanolamine absorption/stripping by developing an alternative solvent, aqueous K{sub 2}CO{sub 3} promoted by piperazine. Progress has been made in this reporting period on three subtasks. The rigorous Electrolyte Non-Random Two-Liquid (electrolyte-NRTL) model has been regressed to represent CO{sub 2} solubility in potassium carbonate/bicarbonate solutions. An analytical method for piperazine has been developed using a gas chromatograph. Funding has been obtained and equipment has been donated to provide for modifications of the existing pilot plant system with stainless steel materials.

Gary T. Rochelle; A. Frank Seibert; J. Tim Cullinane; Terraun Jones

2003-01-01

295

Asymptotic models for H{sub 2}S absorption into single and blended aqueous amines  

SciTech Connect

Asymptotic power series solutions for the mass-transfer enhancement factor for absorption of a gas component into a liquid where it undergoes irreversible instantaneous chemical reaction(s) with one and two liquid-phase reactants are developed in this work. The Pade technique is used to extend the region of applicability (accelerate the convergence) of the four-term asymptotic power series solutions. The resulting modified asymptotic expressions for the enhancement factor show excellent accuracy over a wide range and can be used to predict enhancement factors as low as 2 with an error of about 5% compared to the exact numerical solution. Predictions of these new asymptotic solutions are compared to the exact numerical solution. Predictions of these new asymptotic solutions are compared with experimental absorption data for H{sub 2}S absorption into aqueous methyldiethanolamine and H{sub 2}S absorption into aqueous mixtures of methyldiethanolamine and diethanolamine obtained in a laminar-jet absorber. The absolute mean deviations of the predictions from the experimental absorption data for the single and mixed amine solutions were 4.6% and 2.4%, respectively.

Rinker, E.B.; Hanna, O.T.; Sandall, O.C. [Univ. of California, Santa Barbara, CA (United States). Dept. of Chemical Engineering] [Univ. of California, Santa Barbara, CA (United States). Dept. of Chemical Engineering

1997-01-01

296

Heat capacity of alkanolamine aqueous solutions  

SciTech Connect

Heat capacities of monoethanoloamine, diglycolamine, diethanolamine, di-w propanolamine, triethanolamine, N-methyldiethanolamine, 2-amino-2-methyl-l-propanol, and 2-piperidineethanol aqueous solutions were measured from 30 to 80 C with a differential scanning calorimeter (DSC). The mole fractions of alkanolamines studied are 0.2, 0.4, 0.6, and 0.8. Heat capacities of N-methyldiethanolamine aqueous solutions have been measured to verify the validity of C{sub p} measurements for alkanolamine aqueous solutions. The estimated uncertainty of the measured heat capacities is {plus{underscore}minus}3%, including the effect of up to 5% impurities in a substance. An excess molar heat capacity expression using the Redlich-Kister equation for the composition dependence is used to represent the measured C{sub p} of alkanolamine aqueous solutions. For a total of 374 data points, the calculation results for eight alkanolamine solutions give the overall average absolute deviations of 11.9% and 0.29% for the excess molar heat capacity and the heat capacity, respectively. The heat capacities presented in this study are, in general, of sufficient accuracy for most engineering-design calculations. Solutions of alkanolamines are industrially important mixtures used in the natural gas industry, oil refineries, petroleum chemical plants, and synthetic ammonia plants for the removal of acidic components such as CO{sub 2} and H{sub 2}S from gas streams.

Chiu, L.F.; Li, M.H.

1999-12-01

297

Studies of flammability and thermal degradation for flame retardant cotton fabric with P-N containing derivatives  

Technology Transfer Automated Retrieval System (TEKTRAN)

The effectiveness of a phosphoramidate Tetraethyl piperazine-1,4- diyldiphosphoramidate (TEPP) as a flame retardant (FR) on cotton twill fabrics was compared with that of a previously studied Diethyl 4- methylpiperazin-1-ylphosphoramidate (DEPP). TEPP was formed in a reaction between two phosphonat...

298

The comparison of differences in flammability and thermal degradation between cotton fabrics treated with phosphoramidate derivatives  

Technology Transfer Automated Retrieval System (TEKTRAN)

The effectiveness of a phosphoramidate Tetraethyl piperazine-1,4-diyldiphosphoramidate (TEPP) as a flame retardant (FR) on cotton twill fabrics was compared with that of a previously studied Diethyl 4-methylpiperazin-1-ylphosphoramidate (DEPP). TEPP was formed in a reaction between two phosphonates...

299

Approaches to measuring the activities of protein arginine N-methyltransferases Ted M. Lakowski a  

E-print Network

, trifluoroacetic acid; TLC, thin layer chromatography; UPLC, ultrahigh perfor- mance liquid chromatography chromatography; GAR, glycine- and arginine-rich; GST, glutathione S-transferase; HEPES, 2-[4-(2-hydroxyethyl)piperazine-1-yl]ethanesulfo- nic acid; HPLC, high performance liquid chromatography; LOD, limit of detection

Clarke, Steven

300

Development and validation of chemometrics-assisted spectrophotometric and liquid chromatographic methods for the simultaneous determination of two multicomponent mixtures containing bronchodilator drugs  

Microsoft Academic Search

Three methods are developed for the determination of two multicomponent mixtures containing guaiphenesine (GU) with salbutamol sulfate (SL), methylparaben (MP) and propylparaben (PP) [mixture 1]; and acephylline piperazine (AC) with bromhexine hydrochloride (BX), methylparaben (MP) and propylparaben (PP) [mixture 2]. The resolution of the two multicomponent mixtures has been accomplished by using numerical spectrophotometric methods such as partial least squares

Alaa El-Gindy; Samy Emara; Heba Shaaban

2007-01-01

301

Constrained analogues of tocainide as potent skeletal muscle sodium channel blockers towards the development of antimyotonic agents.  

PubMed

1-Benzyl-N-(2,6-dimethylphenyl)piperidine-3-carboxamide and 4-benzyl-N-(2,6-dimethylphenyl)piperazine-2-carboxamide, two conformationally restricted analogues of tocainide, were designed and synthesized as voltage-gated skeletal muscle sodium channel blockers. They showed, with respect to tocainide, a marked increase in both potency and use-dependent block. PMID:18342401

Catalano, Alessia; Carocci, Alessia; Corbo, Filomena; Franchini, Carlo; Muraglia, Marilena; Scilimati, Antonio; De Bellis, Michela; De Luca, Annamaria; Camerino, Diana Conte; Sinicropi, Maria Stefania; Tortorella, Vincenzo

2008-11-01

302

Constrained analogues of tocainide as potent skeletal muscle sodium channel blockers towards the development of antimyotonic agents  

Microsoft Academic Search

1-Benzyl-N-(2,6-dimethylphenyl)piperidine-3-carboxamide and 4-benzyl-N-(2,6-dimethylphenyl)piperazine-2-carboxamide, two conformationally restricted analogues of tocainide, were designed and synthesized as voltage-gated skeletal muscle sodium channel blockers. They showed, with respect to tocainide, a marked increase in both potency and use-dependent block.

Alessia Catalano; Alessia Carocci; Filomena Corbo; Carlo Franchini; Marilena Muraglia; Antonio Scilimati; Michela De Bellis; Annamaria De Luca; Diana Conte Camerino; Maria Stefania Sinicropi; Vincenzo Tortorella

2008-01-01

303

Nonracemic synthesis of GK-GKRP disruptor AMG-3969.  

PubMed

A nonracemic synthesis of the glucokinase-glucokinase regulatory protein disruptor AMG-3969 (5) is reported. Key features of the synthetic approach are an asymmetric synthesis of the 2-alkynyl piperazine core via a base-promoted isomerization and a revised approach to the synthesis of the aminopyridinesulfonamide with an improved safety profile. PMID:24678849

Bourbeau, Matthew P; Ashton, Kate S; Yan, Jie; St Jean, David J

2014-04-18

304

WHO expert committee on drug dependence.  

PubMed

This report presents the recommendations of a WHO Expert Committee responsible for reviewing information on psychoactive substances to assess the need for their international control. The report contains a summary of the Committee's evaluations of gamma-hydroxybutyric acid (GHB) and ketamine. GHB was recommended to be rescheduled from Schedule IV to Schedule II of the Convention on Psychotropic Substances. The report also discusses the nine substances that were pre-reviewed: dextromethorphan, tapentadol, N-benzylpiperazine (BZP), 1-(3-trifluoromethylphenyl) piperazine (TFMPP), 1-(3-chlorophenyl)piperazine (mCPP), 1-(4-methoxyphenyl)piperazine (MeOPP), 1-(3,4-methylenedioxybenzyl)piperazine (MDBP), gamma-butyrolactone (GBL), and 1,4-butanediol (1,4-BD). Of these, tapentadol, BZP, GBL and 1,4-BD were recommended for critical review. Issues identified for consideration at future Expert Committee meetings are also listed. Furthermore, the report discusses the use of terms, the use of pharmacovigilance data for the assessment of abuse and dependence potential, balancing medical availability and prevention of abuse of medicines manufactured from controlled substances, and improving the process for substance evaluation. PMID:24547667

2012-01-01

305

Binding of Hoechst 33258 to the minor groove of B-DNA.  

PubMed

An X-ray crystallographic structure analysis has been carried out on the complex between the antibiotic and DNA fluorochrome Hoechst 33258 and a synthetic B-DNA dodecamer of sequence C-G-C-G-A-A-T-T-C-G-C-G. The drug molecule, which can be schematized as: phenol-benzimidazole-benzimidazole-piperazine, sits within the minor groove in the A-T-T-C region of the DNA double helix, displacing the spine of hydration that is found in drug-free DNA. The NH groups of the benzimidazoles make bridging three-center hydrogen bonds between adenine N-3 and thymine O-2 atoms on the edges of base-pairs, in a manner both mimicking the spine of hydration and calling to mind the binding of the auti-tumor drug netropsin. Two conformers of Hoechst are seen in roughly equal populations, related by 180 degrees rotation about the central benzimidazole-benzimidazole bond: one form in which the piperazine ring extends out from the surface of the double helix, and another in which it is buried deep within the minor groove. Steric clash between the drug and DNA dictates that the phenol-benzimidazole-benzimidazole portion of Hoechst 33258 binds only to A.T regions of DNA, whereas the piperazine ring demands the wider groove characteristic of G.C regions. Hence, the piperazine ring suggests a possible G.C-reading element for synthetic DNA sequence-reading drug analogs. PMID:2445998

Pjura, P E; Grzeskowiak, K; Dickerson, R E

1987-09-20

306

Preparation and characterization of polypiperazine amide\\/PPESK hollow fiber composite nanofiltration membrane  

Microsoft Academic Search

A modified interfacial polymerization procedure suitable for preparing hollow fiber composite membrane was developed. By this modified procedure, a new hollow fiber composite nanofiltration membrane with high permeability was prepared by interfacial polymerization of piperazine (PIP) aqueous solution and trimesoyl chloride (TMC) hexane solution. The selective layer was synthesized on the inner surface of poly(phthalazinone ether sulfone ketone) (PPESK) hollow

Fajie Yang; Shouhai Zhang; Daling Yang; Xigao Jian

2007-01-01

307

Ureas with histamine H3-antagonist receptor activity--a new scaffold discovered by lead-hopping from cinnamic acid amides.  

PubMed

A group of tri and tetrasubstituted urea derivatives have been found to be hH(3)-antagonists. The most potent compounds were found in the class of (piperazine-1-yl)-(piperidine-1-yl)-methanones which in addition showed negligible hERG inhibition. PMID:16908150

Lau, Jesper F; Jeppesen, Claus Bekker; Rimvall, Karin; Hohlweg, Rolf

2006-10-15

308

Efflux-Related Resistance to Norfloxacin, Dyes, and Biocides in Bloodstream Isolates of Staphylococcus aureus?  

PubMed Central

Efflux is an important resistance mechanism in Staphylococcus aureus, but its frequency in patients with bacteremia is unknown. Nonreplicate bloodstream isolates were collected over an 8-month period, and MICs of four common efflux pump substrates, with and without the broad-spectrum efflux pump inhibitor reserpine, were determined (n = 232). A reserpine-associated fourfold decrease in MIC was considered indicative of efflux. Strains exhibiting efflux of at least two of the four substrates were identified (“effluxing strains” [n = 114]). For these strains, MICs with or without reserpine for an array of typical substrates and the expression of mepA, mdeA, norA, norB, norC, and qacA/B were determined using quantitative real-time reverse transcription-PCR (qRT-PCR). A fourfold or greater increase in gene expression was considered significant. The most commonly effluxed substrates were ethidium bromide and chlorhexidine (100 and 96% of effluxing strains, respectively). qRT-PCR identified strains overexpressing mepA (5 [4.4%]), mdeA (13 [11.4%]), norA (26 [22.8%]), norB (29 [25.4%]), and norC (19 [16.7%]); 23 strains overexpressed two or more genes. Mutations probably associated with increased gene expression included a MepR-inactivating substitution and norA promoter region insertions or deletions. Mutations possibly associated with increased expression of the other analyzed genes were also observed. Effluxing strains comprised 49% of all strains studied (114/232 strains), with nearly half of these overexpressing genes encoding MepA, MdeA, and/or NorABC (54/114 strains). Reduced susceptibility to biocides may contribute to persistence on environmental surfaces, and efflux of drugs such as fluoroquinolones may predispose strains to high-level target-based resistance. PMID:17576828

DeMarco, Carmen E.; Cushing, Laurel A.; Frempong-Manso, Emmanuel; Seo, Susan M.; Jaravaza, Tinevimbo A. A.; Kaatz, Glenn W.

2007-01-01

309

A family of novel Mn?Ln? clusters displaying single-molecule magnet behavior.  

PubMed

Using 3-methyloxysalicylaldoxime (mosaoH2) and N-methyl diethanolamine (N-mdeaH2) as coligands, a family of heptanuclear Mn/Ln heterometallic compounds [Mn(II)Mn(III)2Ln(III)4(mosao)2(mosaoH)4(piv)4(N-mdea)4]·xMeCN [Ln = Dy(1), Tb(2) and Y(3), pivH = pivalic acid] have been prepared. The crystal structures of 1-3 were obtained, and their core consists of two Mn(III)Ln2(?3-OR)2 (RO(2-) = N-mdea(2-)) triangles linked to a central Mn(II) atom. A dc magnetic susceptibility study reveals that single-ion effects of the Ln ions are dominant in compounds 1 and 2. As for compound 3, which contains diamagnetic Y ions, the magnetic interactions between Mn ions via oximate NO bridges are revealed to be ferromagnetic. Fitting of the ?(m)T vs. T data gives g = 1.96 and J = 1.12 cm(-1), affording a S = 13/2 ground state. All of the three compounds exhibit frequency-dependent out-of-phase ac susceptibility signals indicative of slow magnetization relaxation and potential SMM behavior. Among them, 1 and 3 display the out-of-phase ?"(m) peak maximum above 2.0 K. Fitting of the ac susceptibility data to the Arrhenius law gives an energy barrier U(eff) = 9.27/13.83 K for 1 and 3, respectively. PMID:25273696

Chen, Hui; Ma, Cheng-Bing; Hu, Ming-Qiang; Wen, Hui-Min; Chen, Chang-Neng

2014-11-28

310

Mixed solvent system for treating acidic gas  

SciTech Connect

This invention discloses mixtures of alkyl dialcohol amines and mono alkyl ethers of polyethylene glycols which are useful in removing acidic gases from gaseous mixtures. The solvent mixtures contain between 1.5 N and 5.0 N methyl diethanolamine (MDEA), 10 to 40 percent water and the balance is methoxytriglycol (MTG). The overall heat of reaction of the solution is typically less than 500 BTU/lb CO/sub 2/, and remains as a single liquid phase during normal gas scrubber operating conditions.

Capobianco, P.J.; Butwell, K.F.; Kossakowski, E.J.

1987-11-10

311

Aerobic biodegradation of amines in industrial saline wastewaters.  

PubMed

The treatment of hypersaline wastewaters represents a challenge since high salt concentrations disrupt bacteria present in normal biological treatments. This study was conducted to determine the fate of amines in two hypersaline wastewaters obtained from an industrial treatment plant processing influents with 3% and 7% of NaCl. The compounds were aniline (ANL), 4,4'-methylenedianiline (4,4'-MDA), cyclohexylamine (CHA), N-(2-aminoethyl)ethanolamine (AEA), N,N-diethylethanolamine (DEA), N,N-bis(2-hydroxyethyl)methylamine (MDEA), and tris(2-hydroxyethyl)amine (TEA). Mixtures of these chemicals with a mixed liquor suspended solids concentration of 1000 mg L(-1) were prepared at two salinities (3% and 7% NaCl). Ethanolamines were readily biodegraded at both salinities, following first-order kinetics with half-lives ranging between 10 and 58 h. Hydroxyl groups present in the ethanolamines had a positive impact on the biodegradation. Salinity did not affect the biodegradation rate of TEA and MDEA, whereas AEA and DEA degraded faster in 3% NaCl. After 48h, CHA was metabolized within a 24-h period in 3% NaCl, while no degradation was observed in 7% NaCl. ANL exhibited lag phases in both salinities and, in the following 24-h period, ANL concentrations dropped 40% and disappeared after 48 h. 4,4'-MDA degraded in 3% NaCl (half-life of 123 h) and remained unaltered after 120 h in 7% NaCl. PMID:21925703

Campo, Pablo; Platten, William; Suidan, Makram T; Chai, Yunzhou; Davis, John W

2011-11-01

312

Formulated solvents: New opportunities for energy efficient separation of acid gases  

SciTech Connect

A formulated amine can be broadly defined as an amine that has been specifically formulated to perform specific task, for example, selective separation of H{sub 2}S from light hydrocarbons in the presence of CO{sub 2}, bulk separation of CO{sub 2}, and so on. A formulated amine can consist of a single solvent such as methyl diethanolamine (MDEA) or a solvent mixture such as a mixture of MDEA and diethanolamine (DEA) in aqueous solutions. Most of the proprietary solvents marketed by the major solvent manufacturers are based on formulated amines. By judicious choice of a formulated amine or amine mixture, process efficiency of the existing plants can be enhanced significantly compared to the use of traditional amines. Furthermore, some of the gas processing problems that can not be dealt with using the conventional technology in an economical manner can be easily handled with formulated amines. EOR gas processing is such an example. In the case of EOR gas processing, the concentration and volume of CO{sub 2} to be separated from the produced gas increases with time. This creates a major challenge for the design engineer in the design of a processing plant flexible enough to handle variations in CO{sub 2} concentrations ranging from 0 to 80%. Formulated amines may be an answer to this problem. This article will describe the challenges and the opportunities formulated amines may provide to the gas processing industry.

Chakma, A. [Univ. of Calgary, Alberta (Canada). Dept. of Chemical and Petroleum Engineering] [Univ. of Calgary, Alberta (Canada). Dept. of Chemical and Petroleum Engineering

1999-01-01

313

Treat LPGs with amines  

SciTech Connect

In recent years, there has been increasing interest in sweetening liquefied petroleum gases (LPGs) with amines. However, limited data and design information are available in the literature. This article reviews the fundamental aspects of LPG amine treaters and includes guidelines, design considerations and alternatives for static mixers, jet eductor mixers and columns with structured packing, random packing and sieve trays. All of these current design methods are compared based on plant operating data. Guidelines are given for sweetening LPGs with amines including amine type, concentration, filtration, temperature, loading, circulation rate and water-wash systems. Also covered is the contacting method used in the absorber. Any of the commonly available amines such as monoethanolamine (MEA), diethanolamine (DEA), diglycolamine (DGA), methyl diethanolamine (MDEA) and MDEA-based solvents usually perform satisfactorily. Design criteria for distributors and LPG disperser plates, amine filtration and LPG settlers and coalescers are important. The contacting method is also important and includes jet eductor mixers, static mixers, and columns with sieve trays, random packing and structured packing.

Nielsen, R.B. [Fluor Daniel, Inc., Irvine, CA (United States); Rogers, J. [Koch Engineering, Inc., Wichita, KS (United States); Bullin, J.A.; Duewall, K.J. [Bryan Research and Engineering, Inc., Bryan, TX (United States)

1997-09-01

314

Characterization and study of piperazinium salts, degradation products of nitrogen mustards by nuclear magnetic resonance spectroscopy and liquid chromatography-mass spectrometry.  

PubMed

We synthesized and analyzed the degradation products, piperazinium salts from bis(2-chloroethyl)methylamine (HN2) and bis(2-chloroethyl)ethylamine (HN1) using ¹H nuclear magnetic resonance (NMR) and liquid chromatography-mass spectrometry (LC-MS). Piperazinium salt is the major degradation product of HN2, not N-methyldiethanolamine above a concentration of 0.01 M in water and is a non-scheduled chemical that may be generally assumed relevant to the Chemical Weapons Convention (CWC) within the context of the Organization for the Prohibition of Chemical Weapons (OPCW) proficiency test. In verification analysis, ¹H NMR offers real-time information about degradation pathway of nitrogen mustards and LC-MS is expected to play an increasing role in the analysis of environmental samples for the degradation products of chemical warfare agents. PMID:22296978

Lee, Jin Young; Lee, Yong Han; Byun, Yong Gwan

2012-03-01

315

Approximate simulation of CO[sub 2] and H[sub 2]S absorption into aqueous alkanolamines  

SciTech Connect

Rigorous and approximate methods are compared for the simulation of CO[sub 2] absorption into aqueous alkanolamine mixtures of methyldiethanolamine and diethanolamine. In addition, data for the mixtures containing monoethanolamine and the simultaneous absorption of CO[sub 2] and H[sub 2]S are presented. For the rigorous approach, the simplified eddy diffusivity theory is used to simulate the liquid-phase hydrodynamic characteristics. The approximation methods examined are the pseudo-first-order approximation, the interpolation approximation of Wellek et al. (1978), the algebraic combined flux (ACFLUX) approximation and the modified combined flux (MCFLUX) approximation. The latter approximation utilizes the reaction zone concept to determine the kinetic preference of the absorbing gas at the gas-liquid interface. Under the range of conditions studied, the MCFLUX approximation predicts very accurately the CO[sub 2] and H[sub 2]S flux rates in mixed amine systems, as compared with the rigorous solution of the differential equations.

Glasscock, D.A.; Rochelle, G.T. (Univ. of Texas, Austin, TX (United States). Dept. of Chemical Engineering)

1993-08-01

316

Solubility of carbon dioxide and hydrogen sulfide in aqueous alkanolamines  

SciTech Connect

The Deshmukh-Mather thermodynamic model has been fitted to all available, public, phase-equilibrium data for CO[sub 2] and H[sub 2]S in aqueous solutions of monoethanolamine, diethanolamine, diglycolamine, and N-methyldiethanolamine. The fitting was done for both acid gases simultaneously, and the best numerical values of the most important interaction parameters for each amine were obtained. Although the method used for data regression did not provide a statistical measure of the goodness of fit, the regressed model forms a unified basis for evaluating the large amount of data collected over the past 50 years and it results in a rational approach to performing vapor-liquid equilibrium calculations in a computationally affordable, thermodynamically sound manner.

Weiland, R.H. (Univ. of Newcastle, Callaghan (Australia). Dept. of Chemical Engineering); Chakravarty, T. (Bechtel Corp., Houston, TX (United States)); Mather, A.E. (Univ. of Alberta, Edmonton (Canada). Dept. of Chemical Engineering)

1993-07-01

317

Experimental equilibrium between acid gases and ethanolamine solutions  

SciTech Connect

The general subject area of this study is equilibrium solubility of carbon dioxide and hydrogen sulfide in solutions of some common ethanolamines. The amines studied are most widely used in the area of gas sweetening. They include monoethanolamine, diglycolamine, diethanolamine and methyldiethanolamine. Only limited data are available for some of these amines. The process involved developing simple apparatus and procedure for investigating the equilibrium solubility of carbon dioxide and hydrogen sulfide in aqueous alkanolamine solutions. The procedure uses a single equilibrium cell. No gas chromatograph nor liquid chemical analysis is required. Measurements of the solubility were made in different amine solution concentrations at acid gas partial pressures to 1000 psia and temperatures from 77 to 240{degree}F. The method used was found to be sound as indicated by the consistency and reproducibility of the data.

Bhairi, A.M.

1984-01-01

318

Heat capacity of alkanolamines by differential scanning calorimetry  

SciTech Connect

Measurements of the heat capacities of the alkanolamines monoethanolamine, diethanolamine, diglycolamine, di-2-propanolamine, triethanolamine, N-methyldiethanolamine, 2-amino-2-methyl-l-propanol, and 2-piperidineethanol were performed from 30 to 80 C with a differential scanning calorimeter (DSC). The heat capacity of liquid water has been measured to verify the validity of the C{sub p} measurements. The measured C{sub p} of each alkanolamine has been expressed as a function of temperature. The estimated uncertainty of the measured heat capacities including the effect of impurities in a substance with a purity of 95% is {+-}3%. The measured heat capacities are, in general, of sufficient accuracy for most engineering-design calculations.

Chiu, L.F.; Liu, H.F.; Li, M.H. [Chung Yuan Christian Univ., Chung Li (Taiwan, Province of China). Dept. of Chemical Engineering] [Chung Yuan Christian Univ., Chung Li (Taiwan, Province of China). Dept. of Chemical Engineering

1999-05-01

319

Marbofloxacin  

PubMed Central

In the title compound, [systematic name: 9-fluoro-2,3-dihydro-3-methyl-10-(4-methyl­piperazin-1-yl)-7-oxo-7H-pyrido[1,2,3-ij][1,2,4]benzoxadiazine-6-carb­oxy­lic acid], C17H19FN4O4, the carbonyl and carboxyl groups are coplanar with the quinoline ring, making a dihedral angle of 2.39?(2)°. The piperazine ring adopts a chair conformation and the oxadiazinane ring displays an envelope conformation with the CH2 group at the flap displaced by 0.650?(2)?Å from the plane through the other five atoms. The mol­ecular structure exhibits an S(6) ring motif, owing to an intra­molecular O—H?O hydrogen bond. In the crystal, weak C—H?F hydrogen bonds link mol­ecules into layers parallel to the ab plane. PMID:22590047

Shen, Jin; Qian, Jing-Jing; Gu, Jian-Ming; Hu, Xiu-Rong

2012-01-01

320

Marbofloxacin.  

PubMed

IN THE TITLE COMPOUND, [SYSTEMATIC NAME: 9-fluoro-2,3-dihydro-3-methyl-10-(4-methyl-piperazin-1-yl)-7-oxo-7H-pyrido[1,2,3-ij][1,2,4]benzoxadiazine-6-carb-oxy-lic acid], C(17)H(19)FN(4)O(4), the carbonyl and carboxyl groups are coplanar with the quinoline ring, making a dihedral angle of 2.39?(2)°. The piperazine ring adopts a chair conformation and the oxadiazinane ring displays an envelope conformation with the CH(2) group at the flap displaced by 0.650?(2)?Å from the plane through the other five atoms. The mol-ecular structure exhibits an S(6) ring motif, owing to an intra-molecular O-H?O hydrogen bond. In the crystal, weak C-H?F hydrogen bonds link mol-ecules into layers parallel to the ab plane. PMID:22590047

Shen, Jin; Qian, Jing-Jing; Gu, Jian-Ming; Hu, Xiu-Rong

2012-04-01

321

Antitumor Activity of Bis-Indole Derivatives  

PubMed Central

This paper reports the synthesis of compounds formed by two indole systems separated by a heterocycle (pyridine or piperazine). As a primary screening, the new compounds were submitted to the National Cancer Institute for evaluation of antitumor activity in the human cell line screen. The pyridine derivatives were far more active than the piperazine derivatives. For the study of the mechanism of action, the most active compounds were subjected to COMPARE analysis and to further biological tests including proteasome inhibition and inhibition of plasma membrane electron transport. The compound bearing the 5-methoxy-2-indolinone moiety was subjected to the first in vivo experiment (hollow fiber assay) and was active. It was therefore selected for the second in vivo experiment (human tumor xenograft in mice). In conclusion we demonstrated that this approach was successful since some of the compounds described are much more active than the numerous, so far prepared and tested 3-indolylmethylene-2-indolinones. PMID:18598018

Andreani, Aldo; Burnelli, Silvia; Granaiola, Massimiliano; Leoni, Alberto; Locatelli, Alessandra; Morigi, Rita; Rambaldi, Mirella; Varoli, Lucilla; Landi, Laura; Prata, Cecilia; Berridge, Michael V.; Grasso, Carole; Fiebig, Heinz-Herbert; Kelter, Gerhard; Burger, Angelika M.; Kunkel, Mark W.

2009-01-01

322

Use of a hydrolytic procedure and spectrometric methods in the structure elucidation of a thiocarbonyl analogue of sildenafil detected as an adulterant in an over-the-counter herbal aphrodisiac.  

PubMed

A sildenafil-related compound was detected in an herbal dietary supplement marketed as an aphrodisiac. The compound was identified as an analogue of sildenafil in which the carbonyl group in the pyrimidine ring of sildenafil was substituted with a thiocarbonyl group, and the methyl group on the piperazine ring was substituted with a hydroxyethyl group. Based on this structure, the compound was named thiohydroxyhomosildenafil. The structure of the compound was established using HPLCIMS, UV spectrometry, electrospray ionization-MS/MS, NMR spectrometry, and a hydrolytic process. One key product of hydrolysis was 1-(2-hydroxyethyl)-piperazine; the identification of this product defined the amine portion of the compound. Another key product of hydrolysis was hydroxyhomosildenafil, generated by hydrolysis of the thiocarbonyl group to a carbonyl group (C = S --> C = O). Hydroxyhomosildenafil was detected as a minor component in the dietary supplement. PMID:19916370

Reepmeyer, John C; D'Avignon, D André

2009-01-01

323

Fluphenazine dihydro-chloride dimethanol solvate.  

PubMed

In the title compound {systematic name: 1-(2-hy-droxy-eth-yl)-4-[3-(2-trifluoro-methyl-10H-phenothia-zin-10-yl)prop-yl]piperazine-1,4-diium dichloride dimethanol disolvate}, C(22)H(28)F(3)N(3)OS(2+)·2Cl(-)·2CH(3)OH, the dihedral angle between the planes of the two outer benzene rings of the tricyclic phenothia-zine system is 46.91?(13)°. The piperazine ring adopts a chair conformation. The crystal structure is stabilized by O-H?Cl, N-H?Cl, C-H?O, C-H?Cl and C-H?F hydrogen bonds and contacts. PMID:22589880

Petrus, Joanna; Petrus, Rafa?; Czarnik-Matusewicz, Bogus?awa

2012-04-01

324

Synthesis and pharmacological screening of new phenylpiperazinepropane derivatives and their enantiomers.  

PubMed

Enantiomers of phenylpiperazinepropane-1,2-diol derivatives were synthesized with the purpose to obtain a better antitussive activity/sedative effect ratio. (S)-isomers showed better pharmacological profiles than (R)-isomers and corresponding racemates. Among the (S)-isomers, the unsubstituted compound, levodropropizine (S(-)-3-(4-phenyl-piperazin-1-yl)-propane-1,2-diol, DF 526), has the most favourable antitussive activity/sedative effect ratio and was selected for pharmaco-toxicological evaluation. PMID:3196406

Giani, R; Marinone, E; Melillo, G; Borsa, M; Tonon, G C

1988-08-01

325

Antitussive effects of levodropropizine in the dog.  

PubMed

The antitussive activity of levodropropizine (S(-)3-(4-phenyl-piperazine-1-yl)-propane-1,2-diol, DF 526, CAS 99291-25-5) was evaluated after oral administration to the conscious dog. Levodropropizine had a good antitussive activity, comparable with, but having a longer duration of action than dropropizine, the racemate from which it is derived. The antitussive activity of levodropropizine in the dog was approximately 1/20 of that of codeine phosphate. PMID:8147948

Munt, P L; Clavenna, G; Algate, D R; Leach, R M

1994-02-01

326

Molecular structure, hydrogen bonding, basicity and spectroscopic properties of N, N?-dimethylpiperazine betaines and their hydrohalides  

Microsoft Academic Search

Two N,N?-dimethylpiperazine betaines (mono (3) and double (6)) have been synthesized. Betaine 3 reacts with two equivalents of HCl or HBr, while 6 only with one. In the crystal structure of N,N?-dicarboxymethyl-N,N?-dimethylpiperazine monohydrochloride (N,N?-dimethylpiperazine doublebetaine monohydrochloride, 7-Cl) determined by X-ray diffraction, the piperazinium moieties form infinite chains bridged by very strong, symmetrical and linear hydrogen bonds (O?O 2.460(2)Å). The piperazine

Z. Dega-Szafran; M. Jaskólski; I. Kurzyca; P. Barczy?ski; M. Szafran

2002-01-01

327

Effects of sigma ligands on mouse cerebellar cyclic guanosine monophosphate (cGMP) levels in vivo: further evidence for a functional modulation of N-methyl-D-aspartate (NMDA) receptor complex-mediated events by sigma ligands.  

PubMed

In the present investigation, the effects of sigma ligands [WY-47384 [8-fluoro-2,3,4,5-tetrahydro-2[3-(3-pyridinyl)propyl)1H- pyrido(4,3b)indole], (+)-pentazocine, (+)-SFK 10,047 (N-allylnormetazocine), mafoprazine, opipramol, dextromethorphan, dextrorphan, (+)-3-PPP [3-(3-hydroxyphenyl)-N-propylpiperidine], (-)-butaclamol, DTG [1,3-di(2-tolyl)guanidine], rimcazole, ifenprodil and BMY-14802 [alpha-(fluorophenyl)-4-(5-fluoropyrimidinyl)-1-piperazine butanol

Rao, T S; Mick, S J; Cler, J A; Emmett, M R; Dilworth, V M; Contreras, P C; Gray, N M; Wood, P L; Iyengar, S

1991-10-01

328

Insulin radioreceptor assay for human erythrocytes. [¹²⁵I tracer technique  

Microsoft Academic Search

Human erythrocytes have specific insulin receptors. Radioreceptor assay for the determination of insulin binding to these receptors is presented. After two passages over a Boyum-type gradient, erythrocytes from freshly collected heparinized blood were isolated and 3.5 x 10⁹ erythrocytes per milliliter were incubated for 2.5 h in a modified pH 8.0 4-(2-hydroxyethyl)-1-piperazine ethane sulfonate buffer, iodinated insulin (80 pg\\/ml), and

K. K. Gambhir; J. A. Archer; L. Carter

1977-01-01

329

Isometric responses of the paramyosin smooth muscle of Paragordius varius (Leidy), (Aschelminthes, Nematomorpha)  

Microsoft Academic Search

Preliminary isometric responses of the paramyosin smooth body wall muscles of Paragordius varius (Nematomorpha) are reported.1.Brief a.c. or d. c. pulses give typical phasic responses, although the time relations are different (Fig. 1A).2.Longer d.c. (5 sec) (Fig. 1A) as well as ACh (10-6 M) stimulation (Fig. 1B) yield tonic contractions with slow decay of developed tension.3.5-Hydroxytryptamine (5-HT) and piperazine citrate

Curtis J. Swanson

1971-01-01

330

Combination Anthelmintics to Control Gastrointestinal Nematodes in Foals  

E-print Network

lactones; ivermectin and moxidectin). Piperazine and phenothiazine have been used in the past, but are presently infrequently used. When first introduced, all of these drugs had good to excellent efficacy against cyathostomes and ascarids. However... to macrocylic lactones. Vet. Rec. 150: 279-281. Chapman, M. R., D. D. French, C. M. Monahan, and T. R. Klei. 1996. Identification and characterization of a pyrantel pamoate resistant cyanthostome population. Vet. Parasitol. 66: 205-212. Clayton, H. M. 1980...

Volker, Ashley

2010-01-16

331

CGP 47969A: A novel inhibitor of the synthesis of inflammatory cytokines  

Microsoft Academic Search

CGP 47969A is a novel piperazine derivative that inhibits the synthesis of inflammatory cytokines, such as interleukin-1? (IL-1), IL-1? and tumor necrosis factor ? (TNF), in human monocytes stimulated with lipopolysaccharide (LPS), zymosan or IL-1 itself. IC50 values are in the range of 0.3–5 ?mol\\/l. CGP 47969A does not inhibit total protein or RNA synthesis indicating selectivity for cytokine inhibition.

C. Rordorf-Adam; T. Geiger; R. Henn; J. Arnold; R. Solf; I. Wiesenberg; P. G. Ferrini; K. Vosbeck

1994-01-01

332

Serotonin 1A autoreceptor activation by S 15535 enhances circadian activity rhythms in hamsters: Evaluation of potential interactions with serotonin 2A and serotonin 2C receptors  

Microsoft Academic Search

Mammalian circadian activity rhythms are generated by pacemaker cells in the suprachiasmatic nucleus (SCN). As revealed by the actions of diverse agonists, serotonergic input from raphe nuclei generally inhibits photic signaling in the suprachiasmatic nucleus. In contrast, the serotonin (5HT)1A partial agonist, 4-(benzodioxan-5-yl)1-(indan2-yl)piperazine (S 15535), was found to enhance the phase-shifting influence of light on hamster circadian rhythms [Gannon, Neuroscience

R. L. Gannon; M. J. Millan

2006-01-01

333

Growth of polypyrrole-horse radish peroxidase microstructures for H2O2 biosensor  

Microsoft Academic Search

Conducting polymer microstructures for enzymatic biosensors are developed by a facile electrochemical route. Horse radish peroxide entrapped polypyrrole films with bowl shaped microstructures are developed on stainless steel (SS 304) substrates by a single step process. Potentiodynamic scanning\\/ cyclic voltammetry is used for generation of polypyrrole microstructures using electro generated oxygen bubbles stabilized by zwitterionic surfactant\\/buffer N-2-Hydroxyethyl piperazine N-2-ethane sulfonic

Pavan Kumar Kathuroju; Nagaraju Jampana

2011-01-01

334

Characterization of the Allosteric Properties of Thermus thermophilus Phosphofructokinase and the Sources of Strong Inhibitor Binding Affinity and Weak Inhibitory Response  

E-print Network

of the substrate and inhibitor ?Hax Coupling enthalpy for the binding of the substrate and activator ?Hay Coupling enthalpy for the binding of the substrate and inhibitor ?Sax Coupling entropy for the binding of the substrate and activator ?Say Coupling... entropy for the binding of the substrate and inhibitor ?Cp Change in the heat capacity EcPFK Phosphofructokinase from Escherichia coli EDTA Ethylenediamine Tetraacetic Acid EPPS N- [2-Hydroxyethyl] Piperazine--3-Propanesulfonic Acid Fru-6-P...

Shubina-McGresham, Maria

2012-10-19

335

Modification of marine natural product ningalin B and SAR study lead to potent P-glycoprotein inhibitors.  

PubMed

In this study, new marine ningalin B analogues containing a piperazine or a benzoloxy group at ring C have been synthesized and evaluated on their P-gp modulating activity in human breast cancer and leukemia cell lines. Their structure-activity relationship was preliminarily studied. Compounds 19 and 20 are potent P-gp inhibitors. These two synthetic analogues of permethyl ningalin B may be potentially used as effective modulators of P-gp-mediated drug resistance in cancer cells. PMID:25329704

Yang, Chao; Wong, Iris L K; Jin, Wen Bin; Jiang, Tao; Chow, Larry M C; Wan, Sheng Biao

2014-10-01

336

Oxidative metabolism of flunarizine in rat liver microsomes.  

PubMed

The oxidative metabolism of flunarizine [1-[bis(4-fluorophenyl)-methyl]-4-(3-phenyl-2-propenyl)piperazine, FZ] to 1-[bis-(4-fluorophenyl)methyl]piperazine (M-1), 1-[bis(4-fluorophenyl)methyl]-4-[3-(4'-hydroxyphenyl)-2- propenyl]piperazine (M-2) and 4,4'-difluorobenzophenone (M-3) has been studied in liver microsomes of Wistar and Dark Agouti (DA) rats. Kinetic analysis demonstrated a sex difference (male > female) in the formation of M-1 and M-3, but not in that of M-2 in Wistar rats. Comparison of the kinetic data of FZ with those of cinnarizine [1-(diphenylmethyl)-4-(3-phenyl-2-propenyl)piperazine, CZ], a prototypic and unfluorinated drug (Kariya et al., Biochem. Pharmacol., in press) revealed that the formation clearances (Clfs) estimated by Vmax/km for the ring hydroxylated metabolites of FZ and CZ are higher than those for the N-dealkylated metabolites of these drugs in female rats. Furthermore, the introduction of two fluorine atoms to CZ (forming FZ) decreased the Clfs for most of metabolites, especially for the N-dealkylated product, M-3. The formation of the metabolites from FZ was suppressed by carbon monoxide and SKF 525-A, and only the ring hydroxylation forming M-2 was significantly lower in female DA than in female Wistar rats. These results suggest that the microsomal oxidation of FZ is mediated by cytochrome P450, and that a cytochrome P450 isozyme(s) belonging to the CYP2D subfamily is involved in the ring hydroxylation of FZ forming M-2. PMID:1462051

Kariya, S; Isozaki, S; Narimatsu, S; Suzuki, T

1992-10-01

337

SUPPLEMENTARY INFORMATION Basic principles of electrolyte chemistry for microfluidic  

E-print Network

containing 10 mM sodium tetraborate. A second buffer, 20 mM N-[2- hydroxyethyl] piperazine-N-[2-ethanesulfonic acid] (HEPES) and 1 mM sodium tetraborate"11 "25mMsodium carbonate/bicarbonate buffer diluted not reported "sodium buffer solution of pH 8.5"3 Strong acid buffer "buffer solution [79/20/1 (v/v) water

Santiago, Juan G.

338

Tantalum catalyzed hydroaminoalkylation for the synthesis of ?- and ?-substituted N-heterocycles.  

PubMed

Unprotected secondary amines are directly alkylated by C-H functionalization adjacent to nitrogen, thereby opening new routes toward the synthesis of ?- and ?-alkylated N-heterocycles. ?-Alkylated piperidine, piperazine, and azepane products are prepared from heterocycles and alkenes in an atom-economic reaction with excellent regio- and diastereoselectivity. ?-Alkylated N-heterocycles are synthesized via a scalable one-pot alkylation/cyclization procedure generating 3-methylated azetidines, pyrrolidines, and piperidines. PMID:23600625

Payne, Philippa R; Garcia, Pierre; Eisenberger, Patrick; Yim, Jacky C-H; Schafer, Laurel L

2013-05-01

339

Novel cyclopentadienyl tricarbonyl (99m)tc complexes containing 1-piperonylpiperazine moiety: potential imaging probes for sigma-1 receptors.  

PubMed

We report the design, synthesis, and evaluation of a series of novel cyclopentadienyl tricarbonyl (99m)Tc complexes as potent ?1 receptor radioligands. Rhenium compounds 3-(4-(1,3-benzodioxol-5-ylmethyl)piperazin-1-yl)propylcarbonylcyclopentadienyl tricarbonyl rhenium (10a) and 4-(4-(1,3-benzodioxol-5-ylmethyl)piperazin-1-yl)butylcarbonylcyclopentadienyl tricarbonyl rhenium (10b) possessed high in vitro affinity for ?1 receptors and moderate to high selectivity for ?2 receptors and the vesicular acetylcholine transporter. Biodistribution studies in mice demonstrated high initial brain uptake for corresponding (99m)Tc derivatives [(99m)Tc]23 and [(99m)Tc]24 of 2.94 and 2.13% injected dose (ID)/g, respectively, at 2 min postinjection. Pretreatment of haloperidol significantly reduced the radiotracer accumulation of [(99m)Tc]23 or [(99m)Tc]24 in the brain. Studies of the cellular uptake of [(99m)Tc]23 in C6 and DU145 tumor cells demonstrated a reduction of accumulation by incubation with haloperidol, 1-(3,4-dimethoxyphenethyl)-4-(3-phenylpropyl)piperazine (SA4503), or 1,3-di-o-tolyl-guanidine (DTG). Furthermore, blocking studies in C6 glioma-bearing mice confirmed the specific binding of [(99m)Tc]23 to ?1 receptors in the tumor. PMID:25073047

Wang, Xia; Li, Dan; Deuther-Conrad, Winnie; Lu, Jie; Xie, Ying; Jia, Bing; Cui, Mengchao; Steinbach, Jörg; Brust, Peter; Liu, Boli; Jia, Hongmei

2014-08-28

340

Structural aspects of intermolecular interactions in the solid state of 1,4-dibenzylpiperazines bearing nitrile or amidine groups.  

PubMed

The crystal structures of the title 1,4-bis(4-cyanobenzyl)piperazine (1) and 1,4-bis(4-amidinobenzyl)piperazine tetrahydrochloride tetrahydrate (2) are reported. Compound (1) crystallizes in the triclinic space group P\\bar 1 and compound (2) in the monoclinic space group P21/n. In both (1) and (2) the asymmetric unit contains one half of the molecule because the central piperazine rings were located across a symmetry center. The packing of both molecules was dominated by hydrogen bonds. The crystal lattice of (1) was formed by weak C-H...N and C-H...? interactions. The crystal structure of (2) was completely different, with cations as well as chloride anions and water molecules taking part in intermolecular interactions. Single-crystal X-ray diffraction studies combined with density functional theory (DFT) calculations allowed the characterization of the intermolecular interactions in those two systems having different types of very strong electrophilic groups: non-ionic nitrile and ionic amidine. Chemical shift data from (13)C CP/MAS (Cross Polarization Magic Angle Spinning) NMR spectra were analyzed using the different procedures for the theoretical computation of shielding constants. PMID:25274515

Rezler, Mateusz; ?o?ek, Teresa; Wolska, Irena; Maciejewska, Dorota

2014-10-01

341

Nickel(ii) complexes with a flexible piperazinyl moiety: studies on DNA and protein binding and catecholase like properties.  

PubMed

Four new mononuclear Ni(ii) complexes [Ni(L(1))]ClO4 (), [Ni(L(2))]ClO4(), [Ni(SCN)3(CH3OH)(aminoethylpiperazineH)] (), and [Ni(DMSO)4(aminoethylpiperazineH)](ClO4)3()have been synthesized from two Schiff base ligands [L(1) = 1-phenyl-3-((2-(piperidin-4-yl)ethyl)imino)but-1-en-1-ol and L(2) = 4-((2-(piperazin-1-yl)ethyl)imino)pent-2-en-2-ol] by exploiting the flexibility of the piperazinyl moiety. Structural analysis reveals that and are square planar complexes with piperazine rings in boat conformations whereas hydrolysis of Schiff bases (L(1) and L(2)) occurs during formation of octahedral complexes ( and ) with piperazine rings in chair conformations. Screening tests were conducted to quantify the binding ability of complexes (, and ) towards DNA, BSA and HSA and it was found that square planar complexes ( and ) showed more effective binding properties over octahedral complex (). Furthermore, enzyme kinetic studies reflect that square planar complexes ( and ) are also effective in mimicking catecholase like activities over octahedral complex (). Among all the complexes, was found to be the most promising molecule among the series due to its large binding affinity towards different bio-macromolecules and higher T.O.N in the catechol oxidation reaction. PMID:25531802

Das, Mriganka; Nasani, Rajendar; Saha, Manideepa; Mobin, Shaikh M; Mukhopadhyay, Suman

2015-01-20

342

An efficient synthesis and biological screening of benzofuran and benzo[d]isothiazole derivatives for Mycobacterium tuberculosis DNA GyrB inhibition.  

PubMed

A series of twenty eight molecules of ethyl 5-(piperazin-1-yl)benzofuran-2-carboxylate and 3-(piperazin-1-yl)benzo[d]isothiazole were designed by molecular hybridization of thiazole aminopiperidine core and carbamide side chain in eight steps and were screened for their in vitro Mycobacterium smegmatis (MS) GyrB ATPase assay, Mycobacterium tuberculosis (MTB) DNA gyrase super coiling assay, antitubercular activity, cytotoxicity and protein-inhibitor interaction assay through differential scanning fluorimetry. Also the orientation and the ligand-protein interactions of the top hit molecules with MS DNA gyrase B subunit active site were investigated applying extra precision mode (XP) of Glide. Among the compounds studied, 4-(benzo[d]isothiazol-3-yl)-N-(4-chlorophenyl)piperazine-1-carboxamide (26) was found to be the most promising inhibitor with an MS GyrB IC50 of 1.77±0.23?M, 0.42±0.23 against MTB DNA gyrase, MTB MIC of 3.64?M, and was not cytotoxic in eukaryotic cells at 100?M. Moreover the interaction of protein-ligand complex was stable and showed a positive shift of 3.5°C in differential scanning fluorimetric evaluations. PMID:25456076

Reddy, Kummetha Indrasena; Srihari, Konduri; Renuka, Janupally; Sree, Komanduri Shruthi; Chuppala, Aruna; Jeankumar, Variam Ullas; Sridevi, Jonnalagadda Padma; Babu, Kondra Sudhakar; Yogeeswari, Perumal; Sriram, Dharmarajan

2014-10-18

343

Structural aspects of intermolecular interactions in the solid state of 1,4-dibenzylpiperazines bearing nitrile or amidine groups  

PubMed Central

The crystal structures of the title 1,4-bis(4-cyanobenzyl)piperazine (1) and 1,4-bis(4-amidinobenzyl)piperazine tetrahydrochloride tetrahydrate (2) are reported. Compound (1) crystallizes in the triclinic space group and compound (2) in the monoclinic space group P21 /n. In both (1) and (2) the asymmetric unit contains one half of the molecule because the central piperazine rings were located across a symmetry center. The packing of both molecules was dominated by hydrogen bonds. The crystal lattice of (1) was formed by weak C—H?N and C—H?? interactions. The crystal structure of (2) was completely different, with cations as well as chloride anions and water molecules taking part in intermolecular interactions. Single-crystal X-ray diffraction studies combined with density functional theory (DFT) calculations allowed the characterization of the intermolecular interactions in those two systems having different types of very strong electrophilic groups: non-ionic nitrile and ionic amidine. Chemical shift data from 13C CP/MAS (Cross Polarization Magic Angle Spinning) NMR spectra were analyzed using the different procedures for the theoretical computation of shielding constants. PMID:25274515

Rezler, Mateusz; ?o?ek, Teresa; Wolska, Irena; Maciejewska, Dorota

2014-01-01

344

Plasma, oral fluid and sweat wipe ecstasy concentrations in controlled and real life conditions.  

PubMed

In a double-blind placebo controlled study on psychomotor skills important for car driving (Study 1), a 75 mg dose of +/- 3,4-methylenedioxymethamphetamine (MDMA) was administered orally to 12 healthy volunteers who were known to be recreational MDMA-users. Toxicokinetic data were gathered by analysis of blood, urine, oral fluid and sweat wipes collected during the first 5h after administration. Resultant plasma concentrations varied from 21 to 295 ng/ml, with an average peak concentration of 178 ng/ml observed between 2 and 4h after administration. MDA concentrations never exceeded 20 ng/ml. Corresponding MDMA concentrations in oral fluid, as measured with a specific LC-MS/MS method (which required only 50 microl of oral fluid), generally exceeded those in plasma and peaked at an average concentration of 1215 ng/ml. A substantial intra- and inter-subject variability was observed with this matrix, and values ranged from 50 to 6982 ng/ml MDMA. Somewhat surprisingly, even 4-5h after ingestion, the MDMA levels in sweat only averaged 25 ng/wipe. In addition to this controlled study, data were collected from 19 MDMA-users who participated in a driving simulator study (Study 2), comparing sober non-drug conditions with MDMA-only and multiple drug use conditions. In this particular study, urine samples were used for general drug screening and oral fluid was collected as an alternative to blood sampling. Analysis of oral fluid samples by LC-MS/MS revealed an average MDMA/MDEA concentration of 1121 ng/ml in the MDMA-only condition, with large inter-subject variability. This was also the case in the multiple drug condition, where generally, significantly higher concentrations of MDMA, MDEA and/or amphetamine were detected in the oral fluid samples. Urine screening revealed the presence of combinations such as MDMA, MDEA, amph, cannabis, cocaine, LSD and psilocine in the multiple-drug condition. PMID:12208028

Samyn, Nele; De Boeck, Gert; Wood, Michelle; Lamers, Caroline T J; De Waard, Dick; Brookhuis, Karel A; Verstraete, Alain G; Riedel, Wim J

2002-08-14

345

Synthesis, magnetism, and 57Fe Mössbauer spectroscopic study of a family of [Ln3Fe7] coordination clusters (Ln = Gd, Tb, and Er).  

PubMed

The reaction of N-methydiethanolamine (mdeaH2), benzoic acid, FeCl3, and Ln(NO3)3·6H2O or LnCl3·xH2O yields a series of decanuclear coordination clusters, [Ln3Fe7(?4-O)2(?3-OH)2(mdea)7(?-benzoate)4(N3)6]·4MeCN·H2O, where Ln = Gd(III) (1) or Tb(III) (2), and [Er3Fe7(?4-O)2(?3-OH)2(mdea)7(?-benzoate)4(N3)5(MeOH)]Cl·7.5H2O·11.5MeOH (3). The isostructural compounds 1-3 all crystallize isotypically in the triclinic space group P1? with Z = 2, as does the previously reported dysprosium analogue 4. Six of the Fe(III) ions are pseudooctahedrally coordinated, whereas the seventh has a trigonal-bipyramidal coordination geometry. Temperature-dependent direct-current magnetic susceptibility studies indicate that intracluster antiferromagnetic interactions are dominant in 1-3. The frequency-dependent out-of-phase (??) alternating-current susceptibility reveals that 2 undergoes a slow relaxation of its magnetization, presumably resulting from anisotropy of the Tb(III) ions. Between 30 and 295 K, the (57)Fe Mössbauer spectra reveal paramagnetic behavior with six partially resolved quadrupole doublets, one for the trigonal-bipyramidal Fe(III) site and five for the six pseudooctahedral Fe(III) sites. The Mössbauer spectra of 2 and 3 obtained between 3 and 30 K are consistent with the presence of Fe(III) intracluster antiferromagnetic coupling with slow magnetic relaxation relative to the Larmor precession time. Further, the observed changes in the effective magnetic field values in the spectra measured at 3 K with increasing applied field are consistent with the effect of the local spin polarization along the applied magnetic field direction, a behavior reminiscent of antiparallel spin-coupled iron molecular paramagnetic systems. PMID:24089701

Abbas, Ghulam; Lan, Yanhua; Mereacre, Valeriu; Buth, Gernot; Sougrati, Moulay T; Grandjean, Fernande; Long, Gary J; Anson, Christopher E; Powell, Annie K

2013-10-21

346

Heat of Dissolution Measurements for CO2 in Mixed Alkanolamine Solvents  

SciTech Connect

The main objective of this research was to measure heat of dissolution of CO{sub 2} in carefully mixed alkanolamine solvent systems, and provide such directly measured data that might be used for efficient design of CO{sub 2} capture process, and for better understanding of the thermodynamics of CO{sub 2}-Alkanolamine systems. An experimental set-up has been designed using the Isothermal Micro Calorimeter for measuring the solubilities and enthalpies of CO{sub 2} in mixed solvents made of MEA, MDEA, PZ, KF and water. All the measurements were done at temperatures 15, 40, and 75 C by maintaining a constant pressure of 100 psig. A detailed study has been done on the variation of solubilities and enthalpies over a wide range of temperatures, pressures and concentrations, by extracting the information from the literature.

Vinayak Kabadi

2007-03-17

347

Identifying methamphetamine exposure in children  

PubMed Central

Introduction Methamphetamine (MAMP) use, distribution and manufacture remain a serious public health and safety problem in the United States, and children environmentally exposed to MAMP face a myriad of developmental, social and health risks, including severe abuse and neglect necessitating child protection involvement. It is recommended that drug-endangered children receive medical evaluation and care with documentation of overall physical and mental conditions and have urine drug testing.1 The primary aim of this study was to determine the best biological matrix to detect MAMP, amphetamine (AMP), methylenedioxymethamphetamine (MDMA), methylenedioxyamphetamine (MDA) and methylenedioxyethylamphetamine (MDEA) in environmentally exposed children. Method 91 children, environmentally exposed to household MAMP intake, were medically evaluated at the Child and Adolescent Abuse Resource and Evaluation (CAARE) Diagnostic and Treatment Center at the University of California, Davis (UCD) Children's Hospital. MAMP, AMP, MDMA, MDA and MDEA were quantified in urine and oral fluid (OF) by gas chromatography mass spectrometry (GCMS) and in hair by liquid chromatography tandem mass spectrometry (LCMSMS). Results Overall drug detection rates in OF, urine and hair were 6.9%, 22.1% and 77.8%, respectively. Seventy children (79%) tested positive for 1 or more drugs in 1 or more matrices. MAMP was the primary analyte detected in all 3 biological matrices. All positive OF (n=5) and 18 of 19 positive urine specimens also had a positive hair test. Conclusion Hair analysis offered a more sensitive tool for identifying MAMP, AMP and MDMA environmental exposure in children than urine or OF testing. A negative urine, or hair test does not exclude the possibility of drug exposure, but hair testing provided the greatest sensitivity for identifying drug-exposed children. PMID:24263642

Castaneto, Marisol S.; Barnes, Allan J.; Scheidweiler, Karl B.; Schaffer, Michael; Rogers, Kristen K.; Stewart, Deborah; Huestis, Marilyn A.

2013-01-01

348

Enantiomeric analysis of drugs of abuse in wastewater by chiral liquid chromatography coupled with tandem mass spectrometry.  

PubMed

The manuscript concerns the development and validation of a method for enantiomeric analysis of structurally related amphetamines (amphetamine, methamphetamine, 4-methylenedioxymethamphetamine (MDMA), 3,4-methylenedioxyamphetamine (MDA) and 3,4-methylenedioxy-N-ethylamphetamine (MDEA)), ephedrines (ephedrine, pseudoephedrine and norephedrine) and venlafaxine in wastewater by means of chiral chromatography coupled with tandem mass spectrometry. Solid-phase extraction on Oasis HLB sorbent used for sample clean-up and concentration of analytes resulted in very good recoveries accounting for >70%. Signal suppression during MS analysis was negligible for most studied analytes. Resolution of enantiomers of chiral drugs was found to be higher than 1. Preliminary assay validation was undertaken. The mean correlation coefficients of the calibration curves, which were on average higher than 0.997 for all studied analytes, showed good linearity of the method in the studied range. Intra- and inter-day repeatabilities were on average less than 5%. The method quantification limits in wastewater were at low ppt levels and varied from 2.25 to 11.75ng/L. The method was successfully applied for the analysis of raw and treated wastewater samples collected from four wastewater treatment plants. A common occurrence of 1R,2S (-)-ephedrine, 1S,2S (+)-pseudoephedrine and venlafaxine in both raw and treated wastewater samples was observed. Amphetamine, methamphetamine, MDMA and MDEA were also detected in several wastewater samples. The study of enantiomeric fractions of these chiral drugs proved their variable non-racemic composition. The influence of wastewater treatment processes on the enantiomeric composition of chiral drugs was also noted and might indicate enantioselective processes occurring during treatment, although more comprehensive research has to be undertaken to support this hypothesis. PMID:20537654

Kasprzyk-Hordern, Barbara; Kondakal, Vishnu V R; Baker, David R

2010-07-01

349

Diketopiperazine Derivatives from the Marine-Derived Actinomycete Streptomyces sp. FXJ7.328  

PubMed Central

Five new diketopiperazine derivatives, (3Z,6E)-1-N-methyl-3-benzylidene-6-(2S-methyl-3-hydroxypropylidene)piperazine-2,5-dione (1), (3Z,6E)-1-N-methyl-3-benzylidene-6-(2R-methyl-3-hydroxypropylidene)piperazine-2,5-dione (2), (3Z,6Z)-3-(4-hydroxybenzylidene)-6-isobutylidenepiperazine-2,5-dione (3), (3Z,6Z)-3-((1H-imidazol-5-yl)-methylene)-6-isobutylidenepiperazine-2,5-dione (4), and (3Z,6S)-3-benzylidene-6-(2S-but-2-yl)piperazine-2,5-dione (5), were isolated from the marine-derived actinomycete Streptomyces sp. FXJ7.328. The structures of 1–5 were determined by spectroscopic analysis, CD exciton chirality, the modified Mosher’s, Marfey’s and the C3 Marfey’s methods. Compound 3 showed modest antivirus activity against influenza A (H1N1) virus with an IC50 value of 41.5 ± 4.5 ?M. In addition, compound 6 and 7 displayed potent anti-H1N1 activity with IC50 value of 28.9 ± 2.2 and 6.8 ± 1.5 ?M, respectively. Due to the lack of corresponding data in the literature, the 13C NMR data of (3Z,6S)-3-benzylidene-6-isobutylpiperazine-2,5-dione (6) were also reported here for the first time. PMID:23538868

Wang, Pei; Xi, Lijun; Liu, Peipei; Wang, Yi; Wang, Wei; Huang, Ying; Zhu, Weiming

2013-01-01

350

Caenorhabditis elegans neuromuscular junction: GABA receptors and ivermectin action.  

PubMed

The prevalence of human and animal helminth infections remains staggeringly high, thus urging the need for concerted efforts towards this area of research. GABA receptors, encoded by the unc-49 gene, mediate body muscle inhibition in Caenorhabditis elegans and parasitic nematodes and are targets of anthelmintic drugs. Thus, the characterization of nematode GABA receptors provides a foundation for rational anti-parasitic drug design. We therefore explored UNC-49 channels from C. elegans muscle cultured cells of the first larval stage at the electrophysiological and behavioral levels. Whole-cell recordings reveal that GABA, muscimol and the anthelmintic piperazine elicit macroscopic currents from UNC-49 receptors that decay in their sustained presence, indicating full desensitization. Single-channel recordings show that all drugs elicit openings of ?2.5 pA (+100 mV), which appear either as brief isolated events or in short bursts. The comparison of the lowest concentration required for detectable channel opening, the frequency of openings and the amplitude of macroscopic currents suggest that piperazine is the least efficacious of the three drugs. Macroscopic and single-channel GABA-activated currents are profoundly and apparently irreversibly inhibited by ivermectin. To gain further insight into ivermectin action at C. elegans muscle, we analyzed its effect on single-channel activity of the levamisol-sensitive nicotinic receptor (L-AChR), the excitatory receptor involved in neuromuscular transmission. Ivermectin produces a profound inhibition of the frequency of channel opening without significant changes in channel properties. By revealing that ivermectin inhibits C. elegans muscle GABA and L-AChR receptors, our study adds two receptors to the already known ivermectin targets, thus contributing to the elucidation of its pleiotropic effects. Behavioral assays in worms show that ivermectin potentiates piperazine-induced paralysis, thus suggesting that their combination is a good strategy to overcome the increasing resistance of parasites, an issue of global concern for human and animal health. PMID:24743647

Hernando, Guillermina; Bouzat, Cecilia

2014-01-01

351

Three-dimensional hydrogen-bonded framework structures in flunarizinium nicotinate and flunarizinediium bis(4-toluenesulfonate) dihydrate.  

PubMed

The structures of two salts of flunarizine, namely 1-bis[(4-fluorophenyl)methyl]-4-[(2E)-3-phenylprop-2-en-1-yl]piperazine, C26H26F2N2, are reported. In flunarizinium nicotinate {systematic name: 4-bis[(4-fluorophenyl)methyl]-1-[(2E)-3-phenylprop-2-en-1-yl]piperazin-1-ium pyridine-3-carboxylate}, C26H27F2N2(+)·C6H4NO2(-), (I), the two ionic components are linked by a short charge-assisted N-H...O hydrogen bond. The ion pairs are linked into a three-dimensional framework structure by three independent C-H...O hydrogen bonds, augmented by C-H...?(arene) hydrogen bonds and an aromatic ?-? stacking interaction. In flunarizinediium bis(4-toluenesulfonate) dihydrate {systematic name: 1-[bis(4-fluorophenyl)methyl]-4-[(2E)-3-phenylprop-2-en-1-yl]piperazine-1,4-diium bis(4-methylbenzenesulfonate) dihydrate}, C26H28F2N2(2+)·2C7H7O3S(-)·2H2O, (II), one of the anions is disordered over two sites with occupancies of 0.832?(6) and 0.168?(6). The five independent components are linked into ribbons by two independent N-H...O hydrogen bonds and four independent O-H...O hydrogen bonds, and these ribbons are linked to form a three-dimensional framework by two independent C-H...O hydrogen bonds, but C-H...?(arene) hydrogen bonds and aromatic ?-? stacking interactions are absent from the structure of (II). Comparisons are made with some related structures. PMID:25093364

Kavitha, Channappa N; Yathirajan, Hemmige S; Kaur, Manpreet; Hosten, Eric C; Betz, Richard; Glidewell, Christopher

2014-08-15

352

Solvent isotope effects on nucleophilic displacement reactions  

SciTech Connect

The kinetic solvent isotope effect, KSIE, (k/sub H/sub 2/O//k/sub D/sub 2/O/), at 25.0/sup 0/C and ionic strength, I, equal to 0.20 +- 0.02 M was measured for the nucleophilic displacement of iodine ion from iodomethane, iodoacetamide, and iodoacetate ion, thiophene from S-Methylthiophenium ion, and tosylate ion from methyl tosylate by bromide ion, chloride ion, acetate ion, hydroxide ion, water, ammonia, ethylenediamine, n-butylamine, piperazine, piperidine, quinuclidine, and 1,4-Diazabicyclo(2.2.2)octane (DABCO), and the monoprotonated cations of ethylenediamine, piperazine, and DABCO. By means of solvent partition measurements at 25.0/sup 0/C and I = 0.02 M between H/sub 2/O and D/sub 2/O and a common immiscible organic solvent, the ground state activity coefficients in D/sub 2/O, the solution in H/sub 2/O being chosen as the reference state, were determined for the nitrogen-containing nucleophiles (except ammonia) and the substrates methyl tosylate, iodoacetamide, and iodoacetic acid. The solubilities at 25.0/sup 0/C of the picrate and tetraphenylborate salts of the monoprotonated cationic forms of ethylenediamine, piperazine, and DABCO were measured to determine the activity coefficients in D/sub 2/O of these ions relative to an H/sub 2/O reference state. Applying the Eyring equation, the activity coefficients of the transition states in D/sub 2/O, reference state H/sub 2/O, were calculated.

Spiegel, G.W.

1981-01-01

353

Interactions of anthelmintic drugs in Caenorhabditis elegans neuro-muscular ion channel mutants.  

PubMed

Due to the increasing development of anthelmintic resistance in nematodes worldwide, it is important to search for anthelmintic compounds with new modes of action and also to investigate the possibility to combine compounds with possible synergistic effects. There might also be the chance to take advantage of the fact that nematode populations which have developed resistance against one anthelmintic class might respond hypersusceptibly to another drug class. The aim of this study was to investigate responses of Caenorhabditis elegans populations with mutations in neuro-muscular ion channels to different anthelmintic classes. Furthermore, potential synergistic effects between two anthelmintic compounds from different classes, i.e. emodepside and tribendimidine, were studied. Although there was neither a synergistic nor an antagonistic effect between emodepside and tribendimidine, other types of interactions could be identified. The C. elegans GABAA-receptor (GABAA-R) unc-49 mutants, showing decreased emodepside susceptibility, were more susceptible to tribendimidine than wild-type C. elegans. In contrast, the reverse phenomenon - hypersusceptibility to emodepside in tribendimidine resistant acetylcholine-receptor (AChR) loss of function mutants - was not observed. Moreover, the slo-1 mutant strain (completely emodepside resistant) also showed hypersusceptibility to piperazine. Interestingly, neither the GABAA-R unc-49 mutants nor the AChR mutants showed decreased susceptibility against piperazine, although there were some studies that indicated an involvement of GABAA-R or AChR in the piperazine mode of action. In conclusion, the present study provides evidence suggesting that interactions between commercially available anthelmintic drugs with different modes of action might be a relatively common phenomenon but this has to be carefully worked out for each anthelmintic and each anthelmintic drug combination. Moreover, results obtained in C. elegans will have to be confirmed using parasitic nematodes in the future. PMID:23707730

Miltsch, Sandra M; Krücken, Jürgen; Demeler, Janina; Ramünke, Sabrina; Harder, Achim; von Samson-Himmelstjerna, Georg

2013-12-01

354

Bench-Scale Development of a Hybrid Membrane-Absorption CO{sub 2} Capture Process: Preliminary Cost Assessment  

SciTech Connect

This report describes a study of capture costs for a hybrid membrane-absorption capture system based on Membrane Technology and Research, Inc. (MTR)’s low-pressure membrane contactors and the University of Texas at Austin’s 5 m piperazine (PZ) Advanced Flash Stripper (AFS; 5 m PZ AFS) based CO2 capture system. The report is submitted for NETL review, and may be superseded by a final topical report on this topic that will be submitted to satisfy the Task 2 report requirement of the current project (DE-FE0013118).

Freeman, Brice; Kniep, Jay; Pingjiao, Hao; Baker, Richard; Rochelle, Gary; Chen, Eric; Frailie, Peter; Ding, Junyuan; Zhang, Yue

2014-03-31

355

Hygromycin B as an anthelmintic and antibiotic for poultry  

E-print Network

and cecal wursm. Sloan et ~al (1954) showed that a single oral administra Cion of 150 mgs. or more of piperazine adipate/kiIogram of body weight resulted in 97 to 100 percent elimination of + ~alii from chickens without affecting growth or egg production... . 641. 5 400 643, 1 1233 T 1279, & 1256 8 13. 524 13. 272 13. 398 139 . 9 4. 50 139 . 12 6. 00 . 139 21 5. 25 16 gns RygrenPoin/ton RePlieation I 200 . 633. 1 gePliocction II . 200 616 6 I 3 II Conbined 400 624. & 1301. 0 1149. 2 1225. 1...

Latif, Mohammed Abdul

1960-01-01

356

Serotonin receptors in the caudal brainstem are necessary and sufficient for the anorectic effect of peripherally administered mCPP  

Microsoft Academic Search

The role of caudal brainstem 5-HT receptors in mediating the anorectic effect of the direct 5-HT2C\\/1B agonist, mCPP [1-(3-chlorophenyl)piperazine dihydrochloride], was evaluated. We demonstrated, first, that systemic injections\\u000a of mCPP yielded a dose-related suppression of intra-oral intake of 12.5% glucose in intact rats and in chronically maintained\\u000a supracollicular decerebrate rats. The results of the decerebrate experiment suggest that 5-HT receptors

J. M. Kaplan; Sarah Song; Harvey J. Grill

1998-01-01

357

Gas chromatographic-mass spectrometric determination of levodropropizine plasma levels in healthy volunteers.  

PubMed

A gas chromatographic-mass spectrometric method for the qualitative and quantitative analysis of levodropropizine (S(-)-3-(4-phenyl-piperazin-1-yl)-propane-1,2-diol, DF 526) in plasma is described. The method proved to be highly selective and sensitive. Drug concentrations as low as 5 ng/ml could be measured. Levodropropizine plasma levels were measured in 6 healthy volunteers after administration of an acute 60 mg dose. Peak concentrations were reached between 40 and 60 min and measurable amounts of drug were present till 8 h after administration. PMID:3196410

Zaratin, P; De Angelis, L; Cattabeni, F

1988-08-01

358

Antitussive properties of levodropropizine.  

PubMed

The antitussive activity of levodropropizine (S(-)-3-(4-phenyl-piperazin-1-yl)-propane-1,2-diol, DF 526), was evaluated in anaesthetized guinea-pigs and rabbits and in unanaesthetized guinea-pigs. Levodropropizine was shown to have good antitussive activity. Intravenously, it was 1/10 to 1/20 as active as codeine and comparable to dropropizine, from which it is derived, on mechanically and electrically induced coughing in rabbits and guinea-pigs. After oral administration to the guinea-pig the antitussive activity of levodropropizine was comparable with those of both dropropizine and codeine against coughing induced by irritant aerosols. PMID:3196407

Malandrino, S; Melillo, G; Bestetti, A; Borsa, M; Giuliani, P; Tonon, G C

1988-08-01

359

Clinical trials with the new antitussive levodropropizine in adult bronchitic patients.  

PubMed

The results of 6 clinical trials involving a total of 174 patients are reported. Levodropropizine (S(-)-3-(4-phenyl-piperazin-1-yl)-propane-1,2-diol, DF 526) was compared in double-blind manner with placebo, morclofone and cloperastine. The antitussive activity and therapeutic efficacy of the drug were shown to be greater than those of placebo and morclofone and similar to those of cloperastine. Levodropropizine was effective in about 80% of patients; in responders, cough frequency was reduced by an average of 33-51%. Levodropropizine was generally well tolerated and mild side-effects were reported for only 3% of patients. PMID:3058135

Allegra, L; Bossi, R

1988-08-01

360

CO2 CAPTURE BY ABSORPTION WITH POTASSIUM CARBONATE  

SciTech Connect

The objective of this work is to improve the process for CO{sub 2} capture by alkanolamine absorption/stripping by developing an alternative solvent, aqueous K{sub 2}CO{sub 3} promoted by piperazine. Progress has been made in this reporting period on three subtasks. A simple thermodynamic model has been developed to represent the CO{sub 2} vapor pressure and speciation of the new solvent. A rate model has been formulated to predict the CO{sub 2} flux with these solutions under absorber conditions. A process and instrumentation diagram and process flow diagram have been prepared for modifications of the existing pilot plant system.

Gary T. Rochelle; A. Frank Seibert

2002-10-01

361

CO2 CAPTURE BY ABSORPTION WITH POTASSIUM CARBONATE  

SciTech Connect

The objective of this work is to improve the process for CO{sub 2} capture by alkanolamine absorption/stripping by developing an alternative solvent, aqueous K{sub 2}CO{sub 3} promoted by piperazine. A rigorous thermodynamic model has been further developed with a standalone FORTRAN code to represent the CO{sub 2} vapor pressure and speciation of the new solvent. The welding work has initiated and will be completed for a revised startup of the pilot plant in February 2004.

Gary T. Rochelle; Eric Chen; J. Tim Cullinane; Marcus Hillard; Babatunde Oyenekan

2003-10-31

362

Identification of novel sildenafil-analogues in an adulterated herbal food supplement.  

PubMed

A new herbal product advertised as potency pill was sent for analysis by the local authority. The product was tested for the presence of potential derivatives of PDE-5 inhibitors, such as sildenafil, vardenafil, and tadalafil. Sildenafil analogues were identified, in which the piperazine ring and the sulfonyl group were replaced by a piperazinone and a hydroxyethyl structure, respectively. The chemical structures were established by LC-MS in ESI negative mode, UV and NMR spectroscopy (including DEPT, HSQC, HMBC, H,H-COSY, H,H-TOCSY and H,H-NOESY experiments). This is the first report of piperazinonafil and isopiperazinonafil as adulterant in an herbal food supplement. PMID:21821375

Wollein, Uwe; Eisenreich, Wolfgang; Schramek, Nicholas

2011-12-01

363

A theoretical study of the structure and protonation of Palbociclib (PD 0332991)  

NASA Astrophysics Data System (ADS)

The geometry, protonation and chemical shifts of the important new drug, Palbociclib (8-cyclopentyl-6-ethanoyl-5-methyl-2-(5-(piperazin-1-yl)pyridin-2-ylamino)pyrido[2,3-d]pyrimidin-7(8H)-one), have been studied theoretically. The conclusion is that in the active site of its target enzyme, Palbociclib exists as a cation protonated on the nitrogen atom of the pyridine ring. The tautomerism of the neutral form in solution has also been determined indicating that it is a mixture of two imino tautomers in fast equilibrium.

Alkorta, Ibon; Elguero, José

2014-01-01

364

Determination of anthelmintic activity of the leaf and bark extract of tamarindus indica linn.  

PubMed

The aim of the present study was to evaluate the anthelmintic activity of ethanolic and aqueous extract of leaves and bark of Tamarindus indica Linn using Pheretima posthuma and Tubifex tubifex as test worms. The time of paralysis and time of death were studied and the activity was compared with piperazine citrate as reference standard. The alcohol and aqueous extract of bark of Tamarindus indica exhibited significant anthelmintic activity as evidenced by decreased paralyzing time and death time. The results thus support the use of Tamarindus indica as an anthelmintic agent. PMID:22131633

Das, S S; Dey, Monalisha; Ghosh, A K

2011-01-01

365

Determination of Anthelmintic Activity of the Leaf and Bark Extract of Tamarindus Indica Linn  

PubMed Central

The aim of the present study was to evaluate the anthelmintic activity of ethanolic and aqueous extract of leaves and bark of Tamarindus indica Linn using Pheretima posthuma and Tubifex tubifex as test worms. The time of paralysis and time of death were studied and the activity was compared with piperazine citrate as reference standard. The alcohol and aqueous extract of bark of Tamarindus indica exhibited significant anthelmintic activity as evidenced by decreased paralyzing time and death time. The results thus support the use of Tamarindus indica as an anthelmintic agent. PMID:22131633

Das, S. S.; Dey, Monalisha; Ghosh, A. K.

2011-01-01

366

Diamidines versus Monoamidines as Anti-Pneumocystis Agents: An in Vivo Study.  

PubMed

Some compounds articulated around a piperazine or an ethylenediamine linker have been evaluated in vitro to determine their activity in the presence of a 3T6 fibroblast cell line and an axenic culture of Pneumocystis carinii, respectively. The most efficient antifungal derivatives, namely N,N'-bis(benzamidine-4-yl)ethane-1,2-diamine (compound 6, a diamidine) and N-(benzamidine-4-yl)-N'-phenylethane-1,2-diamine (compound 7, a monoamidine), exhibited no cytotoxicity and were evaluated in vivo in a rat model. Only the diamidine 6 emerged as a promising hit for further studies. PMID:24276317

Stanicki, Dimitri; Pottier, Muriel; Gantois, Nausicaa; Pinçon, Claire; Forge, Delphine; Mahieu, Isabelle; Boutry, Sébastien; Eynde, Jean Jacques Vanden; Martinez, Anna; Dei-Cas, Eduardo; Aliouat, El-Moukhtar

2013-01-01

367

Diamidines versus Monoamidines as Anti-Pneumocystis Agents: An in vivo Study  

PubMed Central

Some compounds articulated around a piperazine or an ethylenediamine linker have been evaluated in vitro to determine their activity in the presence of a 3T6 fibroblast cell line and an axenic culture of Pneumocystis carinii, respectively. The most efficient antifungal derivatives, namely N,N?-bis(benzamidine-4-yl)ethane-1,2-diamine (compound 6, a diamidine) and N-(benzamidine-4-yl)-N?-phenylethane-1,2-diamine (compound 7, a monoamidine), exhibited no cytotoxicity and were evaluated in vivo in a rat model. Only the diamidine 6 emerged as a promising hit for further studies. PMID:24276317

Stanicki, Dimitri; Pottier, Muriel; Gantois, Nausicaa; Pinçon, Claire; Forge, Delphine; Mahieu, Isabelle; Boutry, Sébastien; Vanden Eynde, Jean Jacques; Martinez, Anna; Dei-Cas, Eduardo; Aliouat, El-Moukhtar

2013-01-01

368

Synthesis of novel triazole derivatives as inhibitors of cytochrome P450 14?-demethylase (CYP51)  

Microsoft Academic Search

A series of 1-(1H-1,2,4-triazol-1-yl)-2-(2,4-difluorophenyl)-3-[(4-substitutedphenyl)-piperazin-1-yl]-propan-2-ols have been designed and synthesized on the basis of the structure–activity relationships and antimycotic mechanism of azole antifungal agents. Their structures were confirmed by elemental analysis, IR, MS and 1H NMR. Results of preliminary antifungal tests against eight human pathogenic fungi (Candida albicans, Candida parapsilosis, Candida tropicalis, Cryptococcus neoformans, Aspergillus fumigatus, Trichophyton rubrum, Fonsecaea compacta, and

Qing-Yan Sun; Jian-Ming Xu; Yong-Bing Cao; Wan-Nian Zhang; Qiu-Ye Wu; Da-Zhi Zhang; Jun Zhang; Hui-Qing Zhao; Yuan-Ying Jiang

2007-01-01

369

Certain Metal Ions are Inhibitors of Cytochrome b (6) f Complex 'Rieske' Iron-Sulfur Protein Domain Movements  

SciTech Connect

1Abbreviations: cyt, cytochrome; cyt bL, low potential b cytochrome; cyt bH, high potential b cytochrome; DBMIB, 2,5-dibromo-3-methyl-6-isopropylbenzoquinone; DMSO, dimethylsulfoxide; DNP-INT, 2'-iodo-6-isopropyl-3-methyl-2',4,4'-trinitrodiphenylether; EPR, electron paramagnetic resonance; HEPES, n-(2-hydroxyethyl)piperazine-n'-(2-ethanesulfonic acid); NQNO, 2-nonyl-4-hydroxyquinoline n-oxide; ISP, iron-sulfur protein; MOA, E-b-methoxyacrylate; pmf, proton motive force; PC, plastocyanin; PQ, plastoquinone; PQH2, plastoquinol; PS, photosystem; Qi, quinol reductase; Qo, quinol oxidase; UHDBT, 5-n-undecyl-6-hydroxy-4,7-dioxobenzothiazole.

Roberts, Arthur G.; Bowman, Michael K.; Kramer, David M.

2002-03-26

370

Actions of ?2 adrenoceptor ligands at ?2A and 5HT1A receptors: the antagonist, atipamezole, and the agonist, dexmedetomidine, are highly selective for ?2A adrenoceptors  

Microsoft Academic Search

This study examined the activity of chemically diverse ?2 adrenoceptor ligands at recombinant human (h) and native rat (r) ?2A adrenoceptors as compared with 5-HT1A receptors. First, in competition binding experiments at h?2A and h5-HT1A receptors expressed in CHO cells, several compounds, including the antagonists 1-(2-pyrimidinyl)piperazine (1-PP), (?)-idazoxan,\\u000a benalfocin (SKF 86466), yohimbine and RX 821,002, displayed preference for h?2A versus

Adrian Newman-Tancredi; Jean-Paul Nicolas; Valérie Audinot; Samantha Gavaudan; Laurence Verrièle; Manuelle Touzard; Christine Chaput; Nelly Richard; Mark J. Millan

1998-01-01

371

Validated HPLC method for determination of LASSBio-581, a new heterocyclic N-phenylpiperazine derivative, in rat plasma  

Microsoft Academic Search

A rapid, simple and accurate high performance liquid chromatography (HPLC) method was developed and validated for the determination of LASSBio-581 (1-[1-(4-chloro-phenyl)-1H-[1,2,3]triazol-4-ylmethyl]-4-phenyl-piperazine) in rat plasma using ketoconazole as internal standard. Plasma samples were deproteinized with methanol. A good chromatographic separation was achieved using a reversed phase C18 column. Mobile phase consisting of sodium dihydrogen phosphate monohydrate (pH 4.5, 0.02 M) and

L. Tasso; G. Neves; R. Menegatti; C. A. M. Fraga; E. J. Barreiro; V. L. Eifler-Lima; S. M. K. Rates; Teresa Dalla Costa

2003-01-01

372

Evaluation of Anthelmintic Activity of Pistia stratiotes Linn.  

PubMed Central

The ethanolic extract of the plant Pistia stratiotes (Araceae) was investigated for activity against Indian earthworms Pheretima posthuma and nematode Ascardi galli. Various concentrations (10, 20, 50 mg/ml) of ethanolic extract were tested, which involved determination of time of paralysis and time of death of the worms. It was compared with Piperazine citrate (15 mg/ml) and Albendazole (20 mg/ml) as standard reference and normal saline as control. The study indicated the potential usefulness of Pistia stratiotes against earthworm infections. PMID:24825974

Kumar, H. K. Sundeep; Bose, Anindya; Raut, Arundhuti; Sahu, Sujit Kumar; Raju, M. B. V.

2010-01-01

373

Synthesis and antibacterial activity of catecholate-ciprofloxacin conjugates.  

PubMed

The development of an efficient route to obtain artificial siderophore-antibiotic conjugates active against Gram-negative bacteria is crucial. Herein, a practical access to triscatecholate enterobactin analogues linked to the ciprofloxacin along with their antibacterial evaluation are described. Two series of conjugates were obtained with and without a piperazine linker which is known to improve the pharmacokinetics profile of a drug. A monocatecholate-ciprofloxacin conjugate was also synthesized and evaluated. The antibacterial activities against Pseudomonas aeruginosa for some conjugates are related to the iron concentration in the culture medium and seem to depend on the bacterial iron uptake systems. PMID:24972726

Fardeau, Sylvain; Dassonville-Klimpt, Alexandra; Audic, Nicolas; Sasaki, André; Pillon, Marine; Baudrin, Emmanuel; Mullié, Catherine; Sonnet, Pascal

2014-08-01

374

Synthesis and in vitro evaluation of 12-(substituted aminomethyl) berberrubine derivatives as anti-diabetics.  

PubMed

By introducing various amino methyl groups into 12-position of berberrubine, a series of 12-(substituted aminomethyl) berberrubine derivatives were synthesized and evaluated for their anti-diabetic activity against type 2 diabetes mellitus. The results indicated that most of the prepared compounds exhibited moderate to good anti-diabetic activity, which were comparable to or even better than the berberine, the positive control rosiglitazone and insulin. Especially, compound 3b with an N-methyl piperazine-4-methyl group at C-12, exerted the most powerful anti-diabetic activity. PMID:24613165

Li, Renjun; Wu, Jianbo; He, Yun; Hai, Li; Wu, Yong

2014-04-01

375

Toward nonpeptidal substance P mimetic analogues: design, synthesis, and biological activity.  

PubMed

1,4-Piperazine and 4-hydroxyproline, two small cyclic polyfunctional systems with defined stereochemistry, were introduced as "molecular scaffolds." We define a "bioactive topology," which is a derived putative low-energy conformation obtained through theoretical conformational analysis of substance P. Substitution of these molecular scaffolds by pharmacophors characteristic of the bioactive topology of the C-terminal hexapeptide of substance P resulted in active, partially nonpeptidal substance P mimetic agonists. The study discusses the concepts and tools used to achieve this structural transformation, and points out the need to address flexibility-rigidity issues in an attempt to maintain sufficient molecular plasticity. PMID:1718472

Chorev, M; Roubini, E; Gilon, C; Selinger, Z

1991-05-01

376

Synthesis and structure-antibacterial activity of triazolyl oxazolidinones containing long chain acyl moiety.  

PubMed

A series of new piperazinyl 5-triazolylmethyl oxazolidinones containing long chain acyl group at the piperazine N-4-position were synthesized and evaluated against a panel of standard and clinical isolates of Gram-positive and Gram-negative bacteria. Derivatives having long chain acyl groups with nine or more number of carbon atoms showed significant decrease in antibacterial activity. Antibacterial activity correlated positively with heat of formation of the compounds, but correlated negatively with Clog P values, surface area, ovality and molecular volume. However, no significant correlation was observed between activity and E(LUMO), E(HOMO) and dipole, respectively. PMID:18242786

Phillips, Oludotun A; Udo, Edet E; Samuel, Santhosh M

2008-05-01

377

Efficient synthesis of pyrenylalanine.  

PubMed

An efficient synthesis of L-3-(1'-pyrenyl)alanine (Pya), a highly fluorescent amino acid, is described. The amino acid was obtained by the classical asymmetric hydrogenation of chiral 1-acetyl-3-pyrenemethylidene-6-methyl-piperazine-2,5-dione. In the proposed improved procedure mild conditions of the synthesis were applied and the final product--N-tertbutoxycarbonyl-pyrenylalanine--was obtained in good yield. Pyrenylalanine, due to its interesting photophysical properties, can be applied as a fluorescent probe in numerous biochemical and conformational studies. PMID:11764407

Szyma?ska, A; Wiczk, W; Lankiewicz, L

2001-01-01

378

A novel 5HT 2A receptor antagonist exhibits antidepressant-like effects in a battery of rodent behavioural assays: Approaching early-onset antidepressants  

Microsoft Academic Search

Collective evidence suggests that inhibition of neuronal 5-hydroxytryptamine type 2A (5-HT2A) receptors contributes to the assuagement of depression-like behaviour in rodents. The present study evaluated the antidepressant-like effect of the 5-((4-benzo [?] isothiazol-3-yl) piperazin-1-yl) methyl)-6-chloroindolin-2-one (BIP-1), a compound having affinity to 5-HT2A receptors, using a rodent behavioural test battery. Acute BIP-1 (0.25–4mg\\/kg) pretreatment reduced the quipazine-induced head twitches in mice

Dilip Kumar Pandey; Radhakrishnan Mahesh; Akutota Ashok kumar; V. Sambasiva Rao; Muralidharan Arjun; Ramamoorthy Rajkumar

2010-01-01

379

Pharmacophore-based discovery of FXR agonists. Part I: Model development and experimental validation  

PubMed Central

The farnesoid X receptor (FXR) is involved in glucose and lipid metabolism regulation, which makes it an attractive target for the metabolic syndrome, dyslipidemia, atherosclerosis, and type 2 diabetes. In order to find novel FXR agonists, a structure-based pharmacophore model collection was developed and theoretically evaluated against virtual databases including the ChEMBL database. The most suitable models were used to screen the National Cancer Institute (NCI) database. Biological evaluation of virtual hits led to the discovery of a novel FXR agonist with a piperazine scaffold (compound 19) that shows comparable activity as the endogenous FXR agonist chenodeoxycholic acid (CDCA, compound 2). PMID:22018919

Schuster, Daniela; Markt, Patrick; Grienke, Ulrike; Mihaly-Bison, Judit; Binder, Markus; Noha, Stefan M.; Rollinger, Judith M.; Stuppner, Hermann; Bochkov, Valery N.; Wolber, Gerhard

2011-01-01

380

5HT 2C receptors inhibit and 5HT 1A receptors activate the generation of spike–wave discharges in a genetic rat model of absence epilepsy  

Microsoft Academic Search

The present study was conducted to investigate the role of 5-HT2C and 5-HT1A receptors in the generation of spike–wave discharges (SWD) in the genetic absence epilepsy model Wistar Albino Glaxo rats from Rijswijk, Netherlands (WAG\\/Rij rats). We have determined the effects of the 5-HT2C receptor preferring agonist m-chlorophenyl-piperazine (m-CPP), the selective 5-HT2C receptor antagonist SB-242084, the selective 5-HT1A receptor antagonist

Rita Jakus; Marton Graf; Gabriella Juhasz; Katalin Gerber; Gyorgy Levay; Peter Halasz; Gyorgy Bagdy

2003-01-01

381

In Vitro Anthelmintic Activity of Baliospermum montanum Muell. Arg roots  

PubMed Central

Alcohol and aqueous extracts from the roots of Baliospermum montanum Muell. Arg were investigated for their anthelmintic activity against Pheretima posthuma and Ascardia galli. Various concentrations (10-100 mg/ml) of each extract were tested in the bioassay, which involved determination of time of paralysis and time of death of the worms. Both the extracts exhibited significant anthelmintic activity at highest concentration of 100 mg/ml. Piperazine citrate (10 mg/ml) was included as standard reference and distilled water as control. PMID:20390101

Mali, R. G.; Wadekar, R. R.

2008-01-01

382

Characterization of the solubility and solid-state properties of saccharin salts of fluoroquinolones.  

PubMed

Saccharinates salts of the fluoroquinolone antibiotics norfloxacin, ciprofloxacin, ofloxacin, and enrofloxacin were obtained as pure crystalline anhydrous solids with sweet taste. The products were characterized by one- ((13)C) and two-dimensional ((1)H-(13)C) dimensions solid state Nuclear Magnetic Resonance and infrared spectroscopy showing ionic interactions between the saccharine amide and the fluoroquinolone piperazine. Several intermolecular bindings were also identified. Thermal behavior and powder X-ray diffraction provided complementary evidences of salt formation. The series of products showed improved properties with respect to water solubility. A solubility model was developed. These salts would be a good way forward to developing more suitable formulations of these APIs. PMID:19226631

Romañuk, Carolina B; Manzo, Ruben H; Linck, Yamila Garro; Chattah, Ana K; Monti, Gustavo A; Olivera, Maria E

2009-10-01

383

A simple approach for morphology tailoring of alginate particles by manipulation ionic nature of polyurethanes.  

PubMed

A number of different ionic aqueous polyurethane dispersions (PUDs) were synthesized based on NCO-terminated prepolymers. Two different anionic and cationic polyurethane samples were synthesized using dimethylol propionic acid and N-methyldiethanolamine emulsifiers, respectively. Then, proper amounts of PUDs and sodium alginate were mixed to obtain a number of aqueous polyurethane dispersions-sodium alginate (PUD/SA) elastomers. The chemical structure, thermal, morphological, thermo-mechanical and mechanical properties, and hydrophilicity content of the prepared samples were studied by FTIR, EDX, DSC, TGA, SEM, DMTA, tensile testing and contact angle techniques. The cationic polyurethanes and their blends with sodium alginate showed excellent miscibility and highly stretchable properties, while the samples containing anionic polyurethanes and alginate illustrated a poor compatibility and no significant miscibility. The morphology of alginate particles shifted from nanoparticles to microparticles by changing the nature of PUDs from cationic to anionic types. The final cationic elastomers not only showed better mechanical properties but also were formulated easier than anionic samples. PMID:24560945

Daemi, Hamed; Barikani, Mehdi; Barmar, Mohammad

2014-05-01

384

Stress corrosion cracking of carbon steel in amine systems  

SciTech Connect

NACE Task Group T-8-14 was formed by Group Committee T-8 on Refining Industry Corrosion to conduct a survey on stress corrosion cracking (SCC) of existing amine units. The main purpose of the survey was to determine the extent of cracking problems in such units and to examine possible correlations between cracked and noncracked locations to establish possible cause(s) for cracking. A total of 294 completed survey forms were received and analyzed. Cracking was reported in monoethanolamine (MEA), diethanolamine, methyldiethanolamine, and diisopropanolamine solutions but was most prevalent in MEA units. Cracking occurs in all types of equipment and piping operating at all common temperatures. Cracking has been reported in all typical refinery streams containing H/sub 2/S, CO/sub 2/, or a combination of the two. The use of corrosion inhibitors, soda ash, caustic, filters, or reclaimers has no indicated effect on cracking tendencies. The survey results confirmed that stress relieving is a highly effective means of preventing amine SCC.

Richert, J.P.; Bagdasarian, A.J.; Shargay, C.A.

1988-01-01

385

Natural gas treatment: recent developments in desulphurization process  

SciTech Connect

The discovery and utilization of sour gas requires removal of the sulfur compounds, for environmental reasons, to a rather low level. Removal of CO/sub 2/ is less important; a level of one to 2% is tolerated if the gas is sufficiently dry to prevent corrosion. Since the acidities of H/sub 2/S and CO/sub 2/ are similar, total removal is simpler and less expensive than selective desulfurization. Mercaptans require special treatment since they have no acid properties. The method using diethanolamine (DEA) is discussed in detail: it has been successful in over 30 plants, but improvements are still possible. Construction details depend on the quality of the feed gas, on corrosion and on working conditions. Several variations of the process are in use. The main problem still remaining is how to deal with the content of gas in methyl, ethyl and propyl mercaptan. Selective desulfurization has been tried with a new methyl-diethanolamine process. However, nonselective desulfurization is becoming more attractive if the CO/sub 2/ can be recovered, since there is demand for it in some secondary recovery processes.

Not Available

1980-03-13

386

An amide cyclo­phane  

PubMed Central

The title compound, 8,18-dithia-2,6-diaza-13(1,4)-piperidina-1(1,2),4(1,3),7(1,2)-tribenzenaoctadecaphane-10,15-diyne-3,6-dione, C32H30N4O2S2, is composed of a relatively planar bis­(2-mercaptophen­yl)isophthalamide unit linked to a bridging 1,4-di(but-2-yn-1-yl)piperazine unit, forming a macrocycle. The isophthalamide ring is inclined to the outer mercaptophenyl rings by 8.18?(11) and 5.59?(10)°, while these two rings are inclined to one another by 9.10?(12)°. The piperazine ring adopts a chair conformation. There are two intra­molecular N—H?S hydrogen bonds generating S(5) ring motifs. In the crystal, mol­ecules are linked via C—H?S and C—H?O hydrogen bonds, forming slabs lying parallel to (001). An O atom in the isophthalamide group is disordered over two positions with an occupancy ratio of 0.41?(6):0.59?(6). PMID:25249913

Viswanathan, Vijayan; Thirunarayanan, Ayyavu; Rajakumar, Perumal; Velmurugan, Devadasan

2014-01-01

387

Anti-trypanosomal activities and structural chemical properties of selected compound classes.  

PubMed

Potent compounds do not necessarily make the best drugs in the market. Consequently, with the aim to describe tools that may be fundamental for refining the screening of candidates for animal and preclinical studies and further development, molecules of different structural classes synthesized within the frame of a broad screening platform were evaluated for their trypanocidal activities, cytotoxicities against murine macrophages J774.1 and selectivity indices, as well as for their ligand efficiencies and structural chemical properties. To advance into their modes of action, we also describe the morphological and ultrastructural changes exerted by selected members of each compound class on the parasite Trypanosoma brucei. Our data suggest that the potential organelles targeted are either the flagellar pocket (compound 77, N-Arylpyridinium salt; 15, amino acid derivative with piperazine moieties), the endoplasmic reticulum membrane systems (37, bisquaternary bisnaphthalimide; 77, N-Arylpyridinium salt; 68, piperidine derivative), or mitochondria and kinetoplasts (88, N-Arylpyridinium salt; 68, piperidine derivative). Amino acid derivatives with fumaric acid and piperazine moieties (4, 15) weakly inhibiting cysteine proteases seem to preferentially target acidic compartments. Our results suggest that ligand efficiency indices may be helpful to learn about the relationship between potency and chemical characteristics of the compounds. Interestingly, the correlations found between the physico-chemical parameters of the selected compounds and those of commercial molecules that target specific organelles indicate that our rationale might be helpful to drive compound design toward high activities and acceptable pharmacokinetic properties for all compound families. PMID:25416330

Ponte-Sucre, Alicia; Bruhn, Heike; Schirmeister, Tanja; Cecil, Alexander; Albert, Christian R; Buechold, Christian; Tischer, Maximilian; Schlesinger, Susanne; Goebel, Tim; Fuß, Antje; Mathein, Daniela; Merget, Benjamin; Sotriffer, Christoph A; Stich, August; Krohne, Georg; Engstler, Markus; Bringmann, Gerhard; Holzgrabe, Ulrike

2015-02-01

388

A unique dithiocarbamate chemistry during design & synthesis of novel sperm-immobilizing agents.  

PubMed

1-Substituted piperazinecarbodithioates were obtained by an unusual removal of CS2 in benzyl substituted dithiocarbamate derivatives under acid and basic conditions during design and synthesis of 1,4-(disubstituted)piperazinedicarbodithioates as double edged spermicides. A plausible mechanism for CS2 removal has been proposed. All synthesized compounds were subjected to spermicidal, antitrichomonal and antifungal activities. Twenty-one compounds irreversibly immobilized 100% sperm (MEC, 0.06-31.6 mM) while seven compounds exhibited multiple activities. Benzyl 4-(2-(piperidin-1-yl)ethyl) piperazine-1-(carbodithioate) (18) and 1-benzyl 4-(2-(piperidin-1-yl)ethyl)piperazine-1,4-bis(carbodithioate) (24) exhibited appreciable spermicidal (MEC, 0.07 and 0.06 mM), antifungal (MIC, 0.069-0.14 and >0.11 mM) and antitrichomonal (MIC, 1.38 and 0.14 mM) activities. The probable mode of action of these compounds seems to be through sulfhydryl binding which was confirmed by fluorescence labeling of sperm thiols. PMID:24705515

Jangir, Santosh; Bala, Veenu; Lal, Nand; Kumar, Lalit; Sarswat, Amit; Kumar, Lokesh; Kushwaha, Bhavana; Singh, Pratiksha; Shukla, Praveen Kumar; Maikhuri, Jagdamba Prasad; Gupta, Gopal; Sharma, Vishnu Lal

2014-05-21

389

Zero-valent iron mediated degradation of ciprofloxacin - assessment of adsorption, operational parameters and degradation products.  

PubMed

The zero-valent iron (ZVI) mediated degradation of the antibiotic ciprofloxacin (CIP) was studied under oxic condition. Operational parameters such as ZVI concentration and initial pH value were evaluated. Increase of the ZVI concentration from 1 to 5gL(-1) resulted in a sharp increase of the observed pseudo-first order rate constant of CIP degradation, reaching a plateau at around 10 g L(-1). The contribution of adsorption to the overall removal of CIP and dissolved organic carbon (DOC) was evaluated after a procedure of acidification to pH 2.5 with sulfuric acid and sonication for 2 min. Adsorption increased as pH increased, while degradation decreased, showing that adsorption is not important for degradation. Contribution of adsorption was much more important for DOC removal than for CIP. Degradation of CIP resulted in partial defluorination since the fluoride measured corresponded to 34% of the theoretical value after 120 min of reaction. Analysis by liquid chromatography coupled to mass spectrometry showed the presence of products of hydroxylation on both piperazine and quinolonic rings generating fluorinated and defluorinated compounds as well as a product of the piperazine ring cleavage. PMID:25150686

Perini, João Angelo de Lima; Silva, Bianca Ferreira; Nogueira, Raquel F Pupo

2014-12-01

390

Synthesis and characterization of selective dopamine D2 receptor ligands using aripiprazole as the lead compound  

PubMed Central

A series of compounds structurally related to aripiprazole (1), an atypical antipsychotic and antidepressant used clinically for the treatment of schizophrenia, bipolar disorder, and depression, have been prepared and evaluated for affinity at D2-like dopamine receptors. These compounds also share structural elements with the classical D2-like dopamine receptor antagonists, haloperidol, N-methylspiperone, domperidone and benperidol. Two new compounds, 7-(4-(4-(2-methoxyphenyl)piperazin-1-yl)butoxy)-3,4-dihydroquinolin-2(1H)-one oxalate (6) and 7-(4-(4-(2-(2-fluoroethoxy)phenyl)piperazin-1-yl)butoxy)-3,4-dihydroquinolin-2(1H)-one oxalate (7) were found to (a) bind to the D2 receptor subtype with high affinity (Ki values <0.3 nM), (b) exhibit >50-fold D2 versus D3 receptor binding selectivity and (c) be partial agonists at both the D2 and D3 receptor subtype. PMID:21536445

Vangveravong, Suwanna; Zhang, Zhanbin; Taylor, Michelle; Bearden, Melissa; Xu, Jinbin; Cui, Jinquan; Wang, Wei; Luedtke, Robert R.; Mach, Robert H.

2011-01-01

391

The exposure of highly toxic aconitine does not significantly impact the activity and expression of cytochrome P450 3A in rats determined by a novel ultra performance liquid chromatography-tandem mass spectrometric method of a specific probe buspirone.  

PubMed

Aconitum species are widely used to treat rheumatism, cardiovascular diseases, and tumors in China and other Asian countries. The herbs are always used with drugs such as paclitaxel. Aconitine (AC) is one of the main bioactive/high-toxic alkaloids of Aconitum roots. AC is metabolized by cytochrome P450 (CYP) 3A. However, whether AC inhibits/induces CYP3A, which causes drug-drug interaction (DDI) is unclear. Our study aims to explore the potent effects of AC, as a marker component of Aconitum, on CYP3A using the probe buspirone in rats. The effects of oral AC on pharmacokinetics of buspirone were evaluated. CYP3A activity and protein levels in rat liver microsomes pretreated with oral AC were also measured using in vitro buspirone metabolism and Western blot. Buspirone and its major metabolites 1-(2-pyrimidinyl)piperazine and 6'-hydroxybuspirone were determined using a newly validated UPLC-MS/MS method. Single dose and 7-day AC administration at 0.125mg/kg had no effect on CYP3A activity since no change in the formation of 1-(2-pyrimidinyl)piperazine and 6'-hydroxybuspirone. CYP3A activity and protein levels in liver microsomes were also not affected by 7-day AC pretreatment at 0.125mg/kg. Therefore, AC neither inhibits nor induces CYP3A in rats, indicating AC does not cause CYP3A-related DDI in the liver. PMID:23085095

Zhu, Lijun; Yang, Xiaoshan; Zhou, Juan; Tang, Lan; Xia, Bijun; Hu, Ming; Zhou, Fuyuan; Liu, Zhongqiu

2013-01-01

392

Synthesis of ciprofloxacin-conjugated poly (L-lactic acid) polymer for nanofiber fabrication and antibacterial evaluation  

PubMed Central

Ciprofloxacin was conjugated with polylactide (PLA) via the secondary amine group of the piperazine ring using PLA and 7-(4-(2-Chloroacetyl) piperazin-1-yl)-1-cyclopropyl-6-fluoro-1, 4-dihydro-4-oxoquinoline-3-carboxylic acid. Zinc prolinate, a biocompatible catalyst was synthesized, characterized, and used in ring opening polymerization of L-lactide. Five different kinds of OH-terminated poly(L-lactide) (two-, three-, four-, six-arm, star-shaped) homopolymers were synthesized by ring opening polymerization of L-lactide in the presence of dodecanol, glycerol, pentaerythritol, dipentaerythritol as initiator and zinc prolinate as a catalyst. The structures of the polymers and conjugates were thoroughly characterized by means of gel permeation chromatography, matrix-assisted laser desorption/ionization – time of flight mass spectrometry, and nuclear magnetic resonance spectroscopy. PLA (molecular weight =100,000) and ciprofloxacin conjugated PLA were used for fabrication of nonwoven nanofiber mat (diameter ranges; 150–400 nm) having pore size (62–102 nm) using electrospinning. The microbiological assessment shows that the release of ciprofloxacin possesses antimicrobial activity. The drug-release behavior of the mat was studied to reveal potential application as a drug delivery system. The result shows that the ciprofloxacin release rates of the PLA conjugate nonwoven nanofiber mat could be controlled by the drug loading content and the release medium. The development of a biodegradable ciprofloxacin system, based on nonwoven nanofiber mat, should be of great interest in drug delivery systems. PMID:24741303

Parwe, Sharad P; Chaudhari, Priti N; Mohite, Kavita K; Selukar, Balaji S; Nande, Smita S; Garnaik, Baijayantimala

2014-01-01

393

Designer psychostimulants: Pharmacology and differences.  

PubMed

More than 200 novel psychoactive drugs have been reported in Europe, with 73 added in 2012 and additional compounds encountered every week in 2013. Many of these are "designer psychostimulants" which aim to mimic the subjective effects of amphetamines, cocaine or 3,4-methylenedioxymethylamphetamine (MDMA; "Ecstasy"). Several drugs are based on the beta-ketoamphetamine cathinone chemical structure, others include aminoindanes, aminotetralins, piperazines, amphetamine analogues and pipradrol derivatives. Although a detailed analysis of the pharmacology of these novel drugs is largely lacking, a number of scientific studies have been reported in 2011-2013 and these are reviewed. All of the novel psychostimulants activate monoamine systems in the brain - with differing dopamine (DA) v serotonin (5-HT) preferences. Those activating principally DA systems are amphetamine-like stimulants, such as naphyrone, desoxypipradrol, 3,4-methylenedioxypyrovalerone (MDPV), and benzylpiperazine while those preferentially activating 5-HT mechanisms are MDMA-like or cocaine-like stimulants, such as mephedrone, methylone and other substituted cathinones, aminoindanes, aminotetralins and piperazines. The ability of mephedrone and other novel psychostimulants to substitute for methylamphetamine or cocaine in drug discrimination tests in rats, and the ability of mephedrone to induce conditioned place preference and to sustain self-administration behaviour suggests that this and other cocaine/methylamphetamine-like drugs have dependence liability. This article is part of the Special Issue entitled 'CNS Stimulants'. PMID:24456744

Iversen, Leslie; White, Michael; Treble, Ric

2014-12-01

394

Confirming Target Engagement for Reversible Inhibitors In Vivo by Kinetically Tuned Activity-Based Probes  

PubMed Central

The development of small-molecule inhibitors for perturbing enzyme function requires assays to confirm that the inhibitors interact with their enzymatic targets in vivo. Determining target engagement in vivo can be particularly challenging for poorly characterized enzymes that lack known biomarkers (e.g., endogenous substrates and products) to report on their inhibition. Here, we describe a competitive activity-based protein profiling (ABPP) method for measuring the binding of reversible inhibitors to enzymes in animal models. Key to the success of this approach is the use of activity-based probes that show tempered rates of reactivity with enzymes, such that competition for target engagement with reversible inhibitors can be measured in vivo. We apply the competitive ABPP strategy to evaluate a newly described class of piperazine amide reversible inhibitors for the serine hydrolases LYPAL1 and LYPLA2, two enzymes for which selective, in vivo-active inhibitors are lacking. Competitive ABPP identified individual piperazine amides that selectively inhibit LYPLA1 or LYPLA2 in mice. In summary, competitive ABPP adapted to operate with moderately reactive probes can assess the target engagement of reversible inhibitors in animal models to facilitate the discovery of small-molecule probes for characterizing enzyme function in vivo. PMID:22690931

Adibekian, Alexander; Martin, Brent R.; Chang, Jae Won; Hsu, Ku-Lung; Tsuboi, Katsunori; Bachovchin, Daniel A.; Speers, Anna E.; Brown, Steven J.; Spicer, Timothy; Fernandez-Vega, Virneliz; Ferguson, Jill; Hodder, Peter S.; Rosen, Hugh; Cravatt, Benjamin F.

2012-01-01

395

Pharmacokinetics and metabolism of BIBF 1120 after oral dosing to healthy male volunteers.  

PubMed

The pharmacokinetics and metabolism of BIBF 1120, an oral triple angiokinase inhibitor targeting vascular endothelial growth factor receptor (VEGFR), platelet-derived growth factor receptor (PDGFR), and fibroblast growth factor receptor (FGFR), were studied in healthy male volunteers (n?=?8) who had received a single oral dose of 100?mg [(14)C]-radiolabelled BIBF 1120 administered as solution. BIBF 1120 was well-tolerated and rapidly absorbed; median time to reach maximum plasma concentrations was 1.3?h and gMean terminal half-life was 13.7?h. A relatively high apparent total body clearance and volume of distribution possibly indicated a high tissue distribution. Plasma concentrations of BIBF 1120 plus carboxylate metabolite BIBF 1202 were lower than the total [(14)C]-radioactivity in plasma, indicating presence of additional metabolites. Total recovery in excreta was 94.7% 1 week post-dose; mass balance was considered complete after 96?h. BIBF 1120 and metabolites were mainly excreted via faeces. The major metabolic pathway for BIBF 1120 was methyl ester cleavage to BIBF 1202. Subsequently, the free carboxyl group of BIBF 1202 was glucuronidated to 1-O-acylglucuronide. Pathways of minor importance were oxidative N-demethylation to yield BIBF 1053, and oxidation of the piperazine moiety and conjugation. Glucuronidation of the parent drug and formylation of the secondary aliphatic amine of the piperazine ring played a minor role. PMID:21204634

Stopfer, Peter; Rathgen, Karin; Bischoff, Daniel; Lüdtke, Silke; Marzin, Kristell; Kaiser, Rolf; Wagner, Klaus; Ebner, Thomas

2011-04-01

396

Synthesis of 6-fluoro-1,4-dihydro-4-oxo-quinoline-3-carboxylic acid derivatives as potential antimicrobial agents.  

PubMed

In the present study, a series of 1-ethyl/benzyl-6-fluoro-7-(substituted piperazin-1-yl)1,4-dihydro-4-oxo-quinoline-3-carboxylic acid were synthesized and characterized by IR, 1H-NMR, mass spectral and elemental analysis. The in vitro antibacterial and antifungal activities of the compounds were evaluated by paper disc diffusion method. The minimum inhibitory concentrations (MIC) of the compounds were also determined by agar streak dilution method. The in vivo antibacterial activity of the compounds against Escherichia coli was also evaluated by mouse protection test. All the compounds exhibited significant antibacterial and weak antifungal activities. The in vivo antibacterial activity (ED50) against E. coli was 50-160 mg kg(-1) in the order of 7<9<8<10. 1-ethyl-6-fluoro-7-(2,5-dioxo-piperazin-1-yl)1,4-dihydro-4-oxo-quinoline-3-carboxylic acid (7) was found to exhibit the most potent in vitro antimicrobial activity with MIC of 4.1, 3.1, 3.1, 2.4, 1, 1, 25 and >100 microg mL(-1) against Staphylococcus aureus, Staphylococcus epidermidis, Micrococcus luteus, Bacillus cereus, E. coli, Klebsiella pneumoniae, Candida albicans and Aspergillus niger. PMID:14642332

Rameshkumar, Natesh; Ashokkumar, Mohan; Subramanian, Ekambaram Harihara; Ilavarasan, Raju; Sridhar, Seshaiah Krishnan

2003-01-01

397

4-Acetyl­piperazinium picrate  

PubMed Central

In the title salt, C6H13N2O+·C6H2N3O7 ? (systematic name: 4-acetyl­piperazin-1-ium 2,4,6-tri­nitro­phenolate), the piperazin-1-ium ring has a slightly distorted chair conformation. In the picrate anion, the mean planes of the two o-NO2 and p-NO2 groups are twisted with respect to the benzene ring by 15.0?(2), 68.9?(4) and 4.4?(3)°, respectively. In the crystal, N—H?O hydrogen bonds are observed, linking the ions into an infinite chain along [010]. In addition, weak cation–anion C—H?O inter­molecular inter­actions and a weak ?–? stacking inter­action between the benzene rings of the anions, with an inter-centroid distance of 3.771?(8)?Å, help to stabilize the crystal packing, giving an overall sheet structure lying parallel to (100). Disorder was modelled for one of the O atoms in one of the o-NO2 groups over two sites with an occupancy ratio of 0.57?(6):0.43?(6). PMID:24940287

Kavitha, Channappa N.; Kaur, Manpreet; Jasinski, Jerry P.; Yathirajan, Hemmige S.

2014-01-01

398

Blood pH optrode based on evanescent waves and refractive index change  

NASA Astrophysics Data System (ADS)

Sensing pH in blood with an silica multimode optical fiber. This sensor is based on evanescent wave absorption and measures the change of the refractive index and absorption in a cladding made of a biocompatible Polymer. In contrast to many existing fiber optical sensors which are based upon different dyes or florescent material to sense the pH, here presents a solution where a part of the cladding is replaced with a Poly (?-amino ester) made of 1.4-Butanediol diacrylate, Piperazine, and Trimethylolpropane Triacrylate. Piperazine has the feature of changing its volume by swelling or shrinking in response to the pH level. This paper utilizes this dimension effect and measure the refractive index and the absorption of the cladding in respect to different pH-levels. The alteration of refractive index also causes a change in the absorption and therefore the output power changes as a function of the pH level. The sensor is sensitive to pH in a wide spectral range and light absorbency can be observed for wavelengths ranging from UV to far IR.

Hammarling, Krister; Hilborn, Jöns; Nilsson, Hans-Erik; Manuilskiy, Anatoliy

2014-02-01

399

Small molecule disruptors of the glucokinase-glucokinase regulatory protein interaction: 4. Exploration of a novel binding pocket.  

PubMed

Structure-activity relationship investigations conducted at the 5-position of the N-pyridine ring of a series of N-arylsulfonyl-N'-2-pyridinyl-piperazines led to the identification of a novel bis-pyridinyl piperazine sulfonamide (51) that was a potent disruptor of the glucokinase-glucokinase regulatory protein (GK-GKRP) interaction. Analysis of the X-ray cocrystal of compound 51 bound to hGKRP revealed that the 3-pyridine ring moiety occupied a previously unexplored binding pocket within the protein. Key features of this new binding mode included forming favorable contacts with the top face of the Ala27-Val28-Pro29 ("shelf region") as well as an edge-to-face interaction with the Tyr24 side chain. Compound 51 was potent in both biochemical and cellular assays (IC50=0.005 ?M and EC50=0.205 ?M, respectively) and exhibited acceptable pharmacokinetic properties for in vivo evaluation. When administered to db/db mice (100 mg/kg, po), compound 51 demonstrated a robust pharmacodynamic effect and significantly reduced blood glucose levels up to 6 h postdose. PMID:25001129

Hong, Fang-Tsao; Norman, Mark H; Ashton, Kate S; Bartberger, Michael D; Chen, Jie; Chmait, Samer; Cupples, Rod; Fotsch, Christopher; Jordan, Steven R; Lloyd, David J; Sivits, Glenn; Tadesse, Seifu; Hale, Clarence; St Jean, David J

2014-07-24

400

Cr(III), Fe(III) and Co(III) complexes of tetradentate (ONNO) Schiff base ligands: synthesis, characterization, properties and biological activity.  

PubMed

A series of metal complexes were synthesized from equimolar amounts of Schiff bases: 1,4-bis[3-(2-hydroxy-1-naphthaldimine)propyl]piperazine (bappnaf) and 1,8-bis[3-(2-hydroxy-1-naphthaldimine)-p-menthane (damnaf) with metal chlorides. All of synthesized compounds were characterized by elemental analyses, spectral (UV-vis, IR, (1)H-(13)C NMR, LC-MS) and thermal (TGA-DTA) methods, magnetic and conductance measurements. Schiff base complexes supposed in tetragonal geometry have the general formula [M(bappnaf or damnaf)]Cl.nH(2)O, where M=Cr(III), Co(III) and n=2, 3. But also Fe(III) complexes have octahedral geometry by the coordination of two water molecules and the formula is [Fe(bappnaf or damnaf)(H(2)O)(2)]Cl. The changes in the selected vibration bands in FT-IR indicate that Schiff bases behave as (ONNO) tetradentate ligands and coordinate to metal ions from two phenolic oxygen atoms and two azomethine nitrogen atoms. Conductance measurements suggest 1:1 electrolytic nature of the metal complexes. The synthesized compounds except bappnaf ligand have the antimicrobial activity against the bacteria: Escherichia coli (ATCC 11230), Yersinia enterocolitica (ATCC 1501), Bacillus magaterium (RSKK 5117), Bacillus subtilis (RSKK 244), Bacillus cereus (RSKK 863) and the fungi: Candida albicans (ATCC 10239). These results have been considerably interest in piperazine derivatives due to their significant applications in antimicrobial studies. PMID:17904895

Keskio?lu, Eren; Gündüzalp, Ayla Balaban; Cete, Servet; Hamurcu, Fatma; Erk, Birgül

2008-08-01

401

Synthesis, biological evaluation, and structure-activity relationship study of novel cytotoxic aza-caffeic acid derivatives.  

PubMed

Three series of aza-caffeic acid derivatives with different linkers were designed and synthesized. Each of the synthesized derivatives was then used in cytotoxicity screening on either 8 or 12 human cancer cell lines. The structure-activity relationships on three structural regions A, B, and C are analyzed in detail, indicating that a nine bond linker B, containing a piperazine unit, is the most favorable linker leading to the generation of molecules with potent cytotoxicities. Compound (E)-1-(4-(3,4-dichlorobenzyl)piperazin-1-yl)-3-(4-(4-ethoxybenzyloxy)-3,5-dimethoxyphenyl)prop-2-en-1-one (80) exhibited the most significant and selective cytotoxicity to KB, BEL7404, K562, and Eca109 cell lines, with IC(50) values of 0.2, 2.0, 1.7, and 1.1 microM, respectively, stronger than that seen for caffeic acid phenethyl ester (CAPE) and cisplatin (CDDP). Flow cytometric and western blot analysis indicate that compound 80 plays a role in mitochondria-dependent apoptosis activity by suppressing K562 cell proliferation in a concentration- and time-dependent manner. PMID:20673727

Zou, Hongbin; Wu, Hao; Zhang, Xiangnan; Zhao, Yu; Stöckigt, Joachim; Lou, Yijia; Yu, Yongping

2010-09-01

402

Detection of p-chloroamphetamine in urine samples with mass spectrometry.  

PubMed

Designer drugs are introduced periodically to avoid detection and to provide new drugs with different pharmacological activities. During our routine analysis of amphetamine in urine samples, we observed one sample that reacted with immunoassay with high activity. There is one prominent peak in the gas chromatography- mass spectrometry (GC-MS) chromatogram. However, no amphetamine, methamphetamine, MDA, MDMA, MDEA, or ephedrine was detected with GC-MS. Careful examination of the mass spectrum indicated the presence of one fragment ion (m/z 140), which is similar to the base peak of trifluoroacetic anhydride derivative of amphetamine. The characteristic ion cluster representing the presence of one chlorine atom was observed. Investigation with liquid chromatography (LC)-MS detected an unknown compound with molecular ion of m/z 170. This compound was tentatively identified as chloroamphetamine. Pure standard material of p-chloroamphetamine (PCA) was purchased and analyzed with both GC-MS and LC-MS. Identical GC-MS spectra and LC-MS-MS fragmentation patterns were obtained. A GC-MS procedure was developed for the quantitation of PCA. The limits of detection and quantification were 10 ?g/L. Precision was between 1.26% and 4.26%, and bias was between -0.91% and 4.27%. The prevalence PCA positive rate is 0.35% of the samples screened positive for amphetamine. PMID:21513613

Lin, Tsz C; Lin, Dong-Liang; Lua, Ahai C

2011-05-01

403

Cross-reactivity of amphetamine analogues with Roche Abuscreen radioimmunoassay reagents  

SciTech Connect

Cross-reactivity of amphetamine analogues with the Abuscreen amphetamine radioimmunoassay reagents was determined for both the standard and high specificity antibody systems. Compounds tested included 2-methoxyamphetamine, 4-hydroxymethamphetamine, 2,5-dimethoxyamphetamine (DMA), 4-bromo-2,5-dimethoxyamphetamine (DOB), 4-bromo-2,5-dimethoxy-beta-phenethylamine (BDMPEA), 3,4,5-trimethoxyamphetamine (TMA), 3,4-methylenedioxyamphetamine (MDA), N,N-dimethyl-3,4-methylenedioxyamphetamine and N-hydroxy-3,4-methylenedioxyamphetamine (N-OH MDA), 3,4-methylenedioxymethamphetamine (MDMA), 3,4-methylenedioxyethylamphetamine (MDEA), 2,5-dimethoxy-4-ethylamphetamine, 2,5-dimethoxy-4-methylamphetamine (DOM), and 3,4,5-trimethoxyphenethylamine (mescaline). Blank negative reference material was spiked with 1,000 to 100,000 ng/mL of the amphetamine analogue and used as sample in the assays. MDA was the only analogue that showed cross reactivity equal to or greater than that of amphetamine. None of the other analogue compounds demonstrated a positive result at even the highest concentration; however several showed depressed counts at various concentration levels.

Cody, J.T. (Air Force Drug Testing Laboratory, Brooks AFB, TX (USA))

1990-01-01

404

Stereoisomeric profiling of drugs of abuse and pharmaceuticals in wastewaters of Valencia (Spain).  

PubMed

The enantiomeric and diastereomeric profiling of chiral pharmaceuticals (ephedrine, norephedrine, atenolol and venlafaxine) and illicit drugs (amphetamine, methamphetamine, 3,4-methylenedioxyamphetamine (MDA), 3,4-methylenedioxy-N-methylamphetamine (MDMA) and 3,4-methylenedioxy-N-ethylamphetamine (MDEA)) was undertaken over a period of fourteen consecutive days in three wastewater treatment plants (WWTPs) in the city of Valencia, Spain. Degradation efficiency of WWTPs was found to be compound and enantiomer dependent. Selective enantiomer enrichment was observed for several target analytes. Amphetamine and MDMA were enriched with R(-)-enantiomers. 1S,2S(+)-pseudoephedrine was found to be more readily degradable during activated sludge treatment than its diastereomer 1R,2S(-)-ephedrine. Atenolol underwent enrichment with either S(-)- or R(+)-enantiomer in different WWTPs. This unexpected enantiomeric variation in the stereoselective degradation of atenolol could be attributed to different processes utilized during activated sludge treatment. The application of (enantiomeric) profiling of wastewater revealed usage patterns of chiral drugs in the Valencia region. PMID:25029504

Vazquez-Roig, Pablo; Kasprzyk-Hordern, Barbara; Blasco, Cristina; Picó, Yolanda

2014-10-01

405

An "accidental" acute psychosis with ecstasy use.  

PubMed

Over the last 10 years, Europe has witnessed the development of the ecstasy phenomenon; this term is used to describe several products sharing more or less the same effects. The most widely used and hence the most well known is 3,4 MDMA, but MDA, MDEA, MBDB and even 2CB or nexus are available. The psychopathological consequences of MDMA use in man are relatively poorly understood. The case reported here involves an acute psychotic episode with residual symptoms after six months, with a sudden onset at least 12 hours after taking alcohol and ecstasy without realising it, in an individual with no previous psychopathology other than a moderate anxiety disorder. Twelve cases of acute psychotic episodes after taking ecstasy have been reported in the literature; two after taking the drug on two occasions and one after a single use. No authors have examined the previous mental state or possible previous psychopathology with any precision. The present subject had not displayed any previous psychotic behavior when tested with a proven standardized interview technique; this was confirmed by his peers and his family. He did, however, show signs of social phobia. Although the personality of an individual is a factor in taking a drug, and probably in the quality of the psychotropic effects experienced, a host of arguments favor the appearance of psychotic symptoms de novo, which were probably related to direct toxicity by MDMA and/or its metabolites on the serotoninergic neurons. PMID:11333007

Vaiva, G; Boss, V; Bailly, D; Thomas, P; Lestavel, P; Goudemand, M

2001-01-01

406

New antimonato polyoxovanadates based on the [V 14IVSb 8IIIO 42(H 2O)] 4- cluster type  

NASA Astrophysics Data System (ADS)

Two new antimonato polyoxovanadates with compositions (enH 2) 2[V 14Sb 8O 42(H 2O)]•3H 2O ( 1) (en = ethylenediamine) and (ppzH 2) 2[V 14Sb 8O 42(H 2O)] ( 2) (ppz = piperazine) were synthesized under solvothermal conditions. Compound 1 crystallizes in the monoclinic space group P2 1/n with a = 13.6969(8) Å, b = 11.9183(10) Å, c = 19.0413(12) Å, ? = 108.346(7), V = 2950.4(4) Å 3 and compound 2 crystallizes in the monoclinic space group P2 1/c with lattice parameters a = 13.7114(10) Å, b = 11.9476(5) Å, c = 19.9391(14) Å, ? = 109.043(8), V = 3087.6(3) Å 3. The central structural motif of both structures can be derived from the {V 18O 42} archetype cluster replacing four VO 5 square pyramids by four Sb 2O 5 moieties yielding two perpendicular oriented eight-membered rings composed of edge-sharing VO 5 polyhedra. According to bond valence sum calculations the electronic situation in the clusters may be formulated as [V IV14Sb III8O 42(H 2O)] 4-. In compound 1 the cluster anions are arranged along the b-axis in a …ABAB… fashion, whereas the anions in 2 are stacked along the c-axis in a …AAA… mode. In both compounds neighbored clusters exhibit relatively short Sb-O separations indicating weak inter-cluster interactions, leading to a layer-like arrangement of the [V IV14Sb III8O 42(H 2O)] 4- anions. In the structure of 1 the charge balancing organic ammonium ions are fully disordered whereas the organic cations in 2 are ordered. Further characterization of compound 1 and 2 revealed that the initially used N,N,N',N'-tetramethylethylenediamine was decomposed to ethylenediamine in 1 and the applied amine 1 -methylpiperazine was fragmented to piperazine in 2. Syntheses with the latter amine led to crystallization of compound 1. But compound 2 could not be prepared applying piperazine in the reaction slurry.

Antonova, Elena; Wutkowski, Adam; Näther, Christian; Bensch, Wolfgang

2011-12-01

407

Identification of the cytochrome P450 and other enzymes involved in the in vitro oxidative metabolism of a novel antidepressant, Lu AA21004.  

PubMed

1-[2-(2,4-Dimethyl-phenylsulfanyl)-phenyl]-piperazine (Lu AA21004) is a novel antidepressant that is currently in late-stage clinical development for major depressive disorder. In the present study, the metabolism of Lu AA21004 was investigated using human liver microsomes (HLM), human liver S9 fraction, and recombinant enzymes. Lu AA21004 was found in vitro to be oxidized to a 4-hydroxy-phenyl metabolite, a sulfoxide, an N-hydroxylated piperazine, and a benzylic alcohol, which was further oxidized to the corresponding benzoic acid [3-methyl-4-(2-piperazin-1-yl-phenysulfanyl)-benzoic acid (Lu AA34443)]. The formation of the 4-hydroxy-phenyl metabolite was catalyzed by CYP2D6 with some contribution from CYP2C9, whereas the formation of the sulfoxide was mediated by CYP3A4/5 and CYP2A6. CYP2C9 and CYP2C19 were the primary enzymes responsible for formation of the N-hydroxylated metabolite. The benzylic alcohol was formed by CYP2D6 only. The oxidation of the benzylic alcohol to the corresponding benzoic acid of Lu AA21004 was catalyzed by alcohol dehydrogenase and aldehyde dehydrogenase, with some contribution from aldehyde oxidase. CYP2D6 was also capable of catalyzing the formation of the benzoic acid of Lu AA21004; however, its overall contribution to this pathway was negligible. Enzyme kinetic parameters revealed that the rate-limiting step in the formation of the benzoic acid from Lu AA21004 is the formation of the corresponding alcohol. Thus, the intrinsic clearance (V(max)/K(m)) in HLM for metabolism of Lu AA21004 to the benzylic alcohol was 1.13 × 10(-6) l · min(-1) · mg(-1), whereas the subsequent metabolism of the benzylic alcohol to the benzoic acid of Lu AA21004 is characterized by an intrinsic clearance (V(max)/K(m)) in S9 fraction of 922 × 10(-6) l · min(-1) · mg(-1). PMID:22496396

Hvenegaard, Mette G; Bang-Andersen, Benny; Pedersen, Henrik; Jørgensen, Morten; Püschl, Ask; Dalgaard, Lars

2012-07-01

408

Azide groups in higher oxidation state manganese cluster chemistry: from structural aesthetics to single-molecule magnets.  

PubMed

This Forum Article overviews the recent amalgamation of two long-established areas, manganese/oxo coordination cluster chemistry involving the higher Mn(II)/Mn(IV) oxidation states and transition-metal azide (N(3)(-)) chemistry. The combination of azide and alkoxide- or carboxylate-containing ligands in Mn chemistry has led to a variety of new polynuclear clusters, high-spin molecules, and single-molecule magnets, with metal nuclearities ranging from Mn(4) to Mn(32) and with ground-state spin values as large as S = 83/2. The organic bridging/chelating ligands are discussed separately as follows: (i) pyridyl alkoxides [the anions of 2-(hydroxymethyl)pyridine (hmpH), 2,6-pyridinedimethanol (pdmH(2)), and the gem-diol form of di-2-pyridyl ketone (dpkdH(2))]; (ii) non-pyridyl alkoxides [the anions of 1,1,1-tris(hydroxymethyl)ethane (thmeH(3)), triethanolamine (teaH(3)), and N-methyldiethanolamine (mdaH(2))]; (iii) other alcohols [the anions of 2,6-dihydroxymethyl-4-methylphenol (LH(3)) and Schiff bases]; (iv) pyridyl monoximes/dioximes [the anions of methyl-2-pyridyl ketone oxime (mpkoH), phenyl-2-pyridyl ketone oxime (ppkoH), and 2,6-diacetylpyridine dioxime (dapdoH(2))]; (v) non-pyridyl oximes [the anions of salicylaldoxime (saoH(2)) and its derivatives R-saoH(2)]. The large structural diversity of the resulting complexes stems from the combined ability of the azide and organic ligands to adopt a variety of ligation and bridging modes. The combined work demonstrates the synthetic novelty that arises when azide is used in conjunction with alcohol-based chelates, the aesthetic beauty of the resulting molecules, and the often fascinating magnetic properties that these compounds possess. This continues to emphasize the extensive and remarkable ability of Mn chemistry to satisfy a variety of different tastes. PMID:19364123

Stamatatos, Theocharis C; Christou, George

2009-04-20

409

High throughput screening of CO2 solubility in aqueous monoamine solutions.  

PubMed

Post-combustion Carbon Capture and Storage technology (CCS) is viewed as an efficient solution to reduce CO(2) emissions of coal-fired power stations. In CCS, an aqueous amine solution is commonly used as a solvent to selectively capture CO(2) from the flue gas. However, this process generates additional costs, mostly from the reboiler heat duty required to release the carbon dioxide from the loaded solvent solution. In this work, we present thermodynamic results of CO(2) solubility in aqueous amine solutions from a 6-reactor High Throughput Screening (HTS) experimental device. This device is fully automated and designed to perform sequential injections of CO(2) within stirred-cell reactors containing the solvent solutions. The gas pressure within each reactor is monitored as a function of time, and the resulting transient pressure curves are transformed into CO(2) absorption isotherms. Solubility measurements are first performed on monoethanolamine, diethanolamine, and methyldiethanolamine aqueous solutions at T = 313.15 K. Experimental results are compared with existing data in the literature to validate the HTS device. In addition, a comprehensive thermodynamic model is used to represent CO(2) solubility variations in different classes of amine structures upon a wide range of thermodynamic conditions. This model is used to fit the experimental data and to calculate the cyclic capacity, which is a key parameter for CO(2) process design. Solubility measurements are then performed on a set of 50 monoamines and cyclic capacities are extracted using the thermodynamic model, to asses the potential of these molecules for CO(2) capture. PMID:21341690

Porcheron, Fabien; Gibert, Alexandre; Mougin, Pascal; Wender, Aurélie

2011-03-15

410

HPLC and MS/MS study of polar contaminants in a wetland adjoining a sour-gas plant  

SciTech Connect

An analytical methodology was developed for target analyses and broad spectrum characterization of polar contaminants such as nitrogenous and organosulfur compounds in wetlands using the complementary techniques of HPLC with electrochemical (EC) detection and tandem MS with probe and electrospray ionization. Tandem MS was well suited for the identification and quantification of mixtures of polar compounds in water samples and soil extracts, while HPLC-EC provided sensitive detection of compounds transparent to MS detection and conventional methods. The usefulness of the methodology is demonstrated by studying the removal of polar contaminants from a wetland in western Canada affected by releases of hydrocarbon-rich condensate and free product from an adjoining sour-gas plant. The concern is that the mobile water-soluble polar contaminants may not be as efficiently attenuated by volatilization or adsorption processes as the more hydrophobic hydrocarbons and that some of the polar toxic compounds may break through to contaminate groundwater and surface waters. Samples of groundwater, surface water, and aqueous soil extracts were analyzed to quantify levels of polar contaminants in the presence of high concentrations of hydrocarbons. The use of water extracts reduced the background interference from hydrocarbons and other non-polar compounds that were present in the soil samples. HPLC-EC was used to quantify the target compounds that included monoethanolamine, diethanolamine and methyldiethanolamine and sulfolane-derived compounds while tandem MS was used to identify related compounds and degradation products. Influent concentrations were in the ppm range and discharge concentrations were in the ppb range.

Dickson, L.C.; Headley, J.V.; Peru, K. [National Hydrology Research Inst., Saskatoon, Saskatchewan (Canada); Spiegel, K.; Gandrass, J. [GKSS Research Centre, Geesthacht (Germany)

1995-12-31

411

Antitussive activity and respiratory system effects of levodropropizine in man.  

PubMed

Antitussive activity of the new antitussive drug, levodropropizine (S(-)-3-(4-phenyl-piperazin-1-yl)-propane-1,2-diol, DF 526), was evaluated in healthy volunteers by the classical method of citric acid-induced coughing. Levodropropizine dose-dependently reduced cough frequency. Maximal inhibition was observed at 6 h after administration. Cough intensity was also reduced, as shown by the analysis of cough noise. Levodropropizine, at the dosage of 60 mg t.i.d., had no adverse effects on respiratory function nor on airway clearance mechanisms: in fact, it did not affect spirometric parameters. Levodropropizine had no effects on the rheological properties of mucus nor on ciliary activity of airway epithelium. PMID:3196411

Bossi, R; Braga, P C; Centanni, S; Legnani, D; Moavero, N E; Allegra, L

1988-08-01

412

General pharmacology of the new antitussive levodropropizine.  

PubMed

The general pharmacological profile of levodropropizine (S(-)3-(4-phenyl-piperazin-1-yl)-propane-1,2-diol, DF 526), a new antitussive drug, was compared with that of dropropizine racemate. Levodropropizine had weaker central sedative effects than the racemate and it did not induce physical dependence in rats. When given intravenously or intraperitoneally, levodropropizine did not exert any significant effects on the cardiovascular and respiratory systems. Receptor binding data excluded interaction with beta-adrenergic, muscarinic and opiate receptors. On the contrary, levodropropizine has affinity for H1-histaminic and alpha-adrenergic receptors. The affinity was also confirmed with isolated organ preparations. On the basis of this study, levodropropizine appears to have a better tolerability index than the racemate. PMID:3196408

Melillo, G; Malandrino, S; Rossoni, G; Caselli, G; Bestetti, A; Borsa, M; Tonon, G C; Berti, F

1988-08-01

413

A comparative study of the anthelmintic potential of cleome viscosa L. And cleome burmanni w. And a.  

PubMed

Methanol, aqueous and chloroform extracts of Cleome viscosa and Cleome burmanni were tested for anthelmintic potential against the Indian earthworm Pheritima posthuma. Different concentrations of the extracts ranging from 50-2000 ?g/ml were tested and results expressed as time required for paralysis and death of the worms. Piperazine citrate was used as a reference standard and DMSO (1%) as the negative control. The methanol extracts of Cleome viscosa and Cleome burmanni exhibited significant anthelmintic activity. Methanol extract of Cleome viscosa at a concentration of 2000 ?g/ml was detected to be the most effective treatment dose. Thin layer chromatography of methanol extracts of both plants revealed the presence of terpenoids. PMID:22131631

Pillai, Lakshmi S; Nair, Bindu R

2011-01-01

414

A Comparative Study of the Anthelmintic Potential of Cleome Viscosa L. and Cleome Burmanni W. and A.  

PubMed Central

Methanol, aqueous and chloroform extracts of Cleome viscosa and Cleome burmanni were tested for anthelmintic potential against the Indian earthworm Pheritima posthuma. Different concentrations of the extracts ranging from 50-2000 ?g/ml were tested and results expressed as time required for paralysis and death of the worms. Piperazine citrate was used as a reference standard and DMSO (1%) as the negative control. The methanol extracts of Cleome viscosa and Cleome burmanni exhibited significant anthelmintic activity. Methanol extract of Cleome viscosa at a concentration of 2000 ?g/ml was detected to be the most effective treatment dose. Thin layer chromatography of methanol extracts of both plants revealed the presence of terpenoids. PMID:22131631

Pillai, Lakshmi S.; Nair, Bindu R.

2011-01-01

415

Isotopic profiling of seized benzylpiperazine and trifluoromethylphenylpiperazine tablets using ?(13)C and ?(15)N stable isotopes.  

PubMed

This paper demonstrates the use of isotopic analysis of 23 benzylpiperazine (BZP) and trifluoromethylphenylpiperazine (TFMPP) containing tablets seized on two independent occasions by the Northern Territory (NT) Police, Australia. Isolation (High Performance Liquid Chromatography (HPLC)) of BZP and TFMPP followed by Isotope Ratio Mass Spectrometry (IRMS) (carbon and nitrogen stable isotopes) analysis was performed. Results are presented for ?(13)C and ?(15)N values of the respective piperazine analogues. The isotopic data and statistical analysis suggest a common source of manufacture for the BZP samples but suggest different sources for the TFMPP isolated from the corresponding BZP containing tablets investigated. The use of IRMS in this case study demonstrated the ability to obtain information regarding the BZP/TFMPP sources unattainable via conventional chemical analysis. PMID:25577007

Beckett, Nicola M; Cresswell, Sarah L; Grice, Darren I; Carter, James F

2015-01-01

416

Sigma ligand-induced emesis in the pigeon.  

PubMed

Pigeons were fed a fixed amount of grain-based feed and behavior was observed after administration of doses of ditolyguanidine (DTG), (+)-3-(3-hydroxyphenyl)-N-(1-propyl)-piperidine [(+)-3-PPP], dextromethorphan, haloperidol, (+)-N-allylnormetazocine (NANM), alpha-(4-fluorophenyl)-4-(5-fluoro-2-pyrimidinyl)-1-piperazine-butanol (BMY-14802) apomorphine, pentobarbital, propranolol, and MK-801. Of the drugs tested, DTG, dextromethorphan, and (+)-3-PPP each produced dose-related increases in the percentage of pigeons exhibiting an emetic response. The emetic response produced by DTG was antagonized by haloperidol and BMY-14802 but not by propranolol. These observations suggest that the emetic response in the pigeon may be mediated by sigma sites and is unlikely to be mediated by phencyclidine receptors. PMID:1347173

Hudzik, T J

1992-01-01

417

CO2 Capture by Absorption with Potassium Carbonate  

SciTech Connect

The objective of this work is to improve the process for CO{sub 2} capture by alkanolamine absorption/stripping by developing an alternative solvent, aqueous K{sub 2}CO{sub 3} promoted by piperazine. In Campaign 3 of the pilot plant, the overall mass transfer coefficient for the stripper with 7 m MEA decreased from 0.06 to 0.01 mol/(m{sup 3}.s.kPa) as the rich loading increased from 0.45 to 0.6 mol CO{sub 2}/mol MEA. Anion chromatography has demonstrated that nitrate and nitrite are major degradation products of MEA and PZ with pure oxygen. In measurements with the high temperature FTIR in 7 m MEA the MEA vapor pressure varied from 2 to 20 Pa at 35 to 70 C. In 2.5 m PZ the PZ vapor pressure varied from 0.2 to 1 Pa from 37 to 70 C.

Gary T. Rochelle; Marcus Hilliard; Eric Chen; Babatunde Oyenekan; Ross Dugas; John McLees; Andrew Sexton; Amorvadee Veawab

2005-01-26

418

N-methylphenylalanyl-dehydrobutyrine diketopiperazine, an A-factor mimic that restores antibiotic biosynthesis and morphogenesis in Streptomyces globisporus 1912-B2 and Streptomyces griseus 1439.  

PubMed

The cell-free extracts of a landomycin E-producing strain, Streptomyces globisporus 1912-2, were shown to contain a low-molecular-weight compound that, like A-factor, restored the landomycin E and streptomycin biosynthesis and sporulation of the defective mutants S. globisporus 1912-B2 and S. griseus 1439, respectively. The compound was purified by thin layer chromatography and HPLC. It had an absorption maximum at ?max=245?nm and a molecular mass of m/z 244. On the basis of NMR spectroscopy ((1)H, (13)C, HSQC, HMBC, COSY and NOE) the chemical structure of the compound was elucidated as 6-benzyl-3-eth-(Z)-ylidene-1-methyl-piperazine-2,6-dione ((L)-N-methylphenylalanyl-dehydrobutyrine diketopiperazine (MDD)). The sequences of arpA genes in S. globisporus 1912-2 and S. griseus NBRC 13350 are highly conserved. An explanation for the observed biological activity of MDD was proposed. PMID:25005816

Matselyukh, Bohdan; Mohammadipanah, Fatemeh; Laatsch, Hartmut; Rohr, Jürgen; Efremenkova, Olga; Khilya, Volodymyr

2015-01-01

419

Vortioxetine for the treatment of major depressive disorder.  

PubMed

Vortioxetine (Brintellix(®), 1-[2-(2,4-dimethylphenyl-sulfanyl)-phenyl]-piperazine) is a multimodal antidepressant targeting the 5-HT1A, 5-HT1B, 5-HT1D, 5-HT3, 5-HT7 receptors and the serotonin (5-HT) transporter (5-HTT). Vortioxetine administration induces antidepressant- and anxiolytic-like effects, and can enhance cognitive performance in rodents. Several clinical trials have reported the efficiency and a satisfactory tolerability of vortioxetine treatment in depressed patients. Remarkably, vortioxetine has a specific positive impact on cognitive symptoms in depressed patients. Overall, vortioxetine is an efficacious antidepressant drug for the treatment of patients with a major depressive episode and has a unique mechanism of action offering a new therapeutic option. PMID:25166025

Tritschler, Laurent; Felice, Daniela; Colle, Romain; Guilloux, Jean-Philippe; Corruble, Emmanuelle; Gardier, Alain Michel; David, Denis Joseph

2014-11-01

420

Synthesis of novel substituted purine derivatives and identification of the cell death mechanism.  

PubMed

Novel 9-(substituted amino/piperazinoethyl)adenines (4-12), 6-(substituted piperazino/amino)purines (15-27), 9-(p-toluenesulfonyl/cyclopentyl/ethoxycarbonylmethyl)-6-(substituted amino/piperazino)purines (28-34, 36, 37, 38-41) were synthesized and evaluated initially for their cytotoxic activities on liver Huh7, breast T47D and colon HCT116 carcinoma cells. N(6)-(4-Trifluoromethylphenyl)piperazine derivative (17) and its 9-(p-toluene-sulfonyl)/9-cyclopentyl analogues (28, 36) had promising cytotoxic activities. Compounds 17, 28 and 36 were further analysed for their cytotoxicity in a panel of a liver cancer cell lines. The compound 36 had better cytotoxic activities (IC50 ? 1 ?M) than the nucleobase 5-FU and nucleosides fludarabine, cladribine, and pentostatine on Huh7 cells. Cytotoxicity induced by 36 was later identified as senescence associated cell death by SA-?-Gal assay. PMID:25462277

Demir, Zeynep; Guven, Ebru Bilget; Ozbey, Suheyla; Kazak, Canan; Atalay, Rengul Cetin; Tuncbilek, Meral

2015-01-01

421

Design, synthesis, biological evaluation of substituted benzofurans as DNA gyraseB inhibitors of Mycobacterium tuberculosis.  

PubMed

DNA gyrase of Mycobacterium tuberculosis (MTB) is a type II topoisomerase and is a well-established and validated target for the development of novel therapeutics. By adapting the medium throughput screening approach, we present the discovery and optimization of ethyl 5-(piperazin-1-yl) benzofuran-2-carboxylate series of mycobacterial DNA gyraseB inhibitors, selected from Birla Institute of Technology and Science (BITS) database chemical library of about 3000 molecules. These compounds were tested for their biological activity; the compound 22 emerged as the most active potent lead with an IC50 of 3.2±0.15?M against Mycobacterium smegmatis DNA gyraseB enzyme and 0.81±0.24?M in MTB supercoiling activity. Subsequently, the binding of the most active compound to the DNA gyraseB enzyme and its thermal stability was further characterized using differential scanning fluorimetry method. PMID:25129171

Renuka, Janupally; Reddy, Kummetha Indrasena; Srihari, Konduri; Jeankumar, Variam Ullas; Shravan, Morla; Sridevi, Jonnalagadda Padma; Yogeeswari, Perumal; Babu, Kondra Sudhakar; Sriram, Dharmarajan

2014-09-01

422

7-chloroquinoline-isatin conjugates: antimalarial, antitubercular, and cytotoxic evaluation.  

PubMed

A series of twenty piperazine-tethered 7-chloroquinoline-isatin hybrids have been synthesized via either direct nucleophilic substitution or Cu(?)Cl-mediated Mannich reaction. These new conjugates were evaluated for their antimalarial and antitubercular efficacy against a chloroquine-resistant strain of Plasmodium falciparum and Mycobacterium tuberculosis, respectively, while the cytotoxic profiles were evaluated against 3T6 cell line, a permanent mouse embryonic fibroblast cell line. The most potent of the test compound with IC50 of 0.22 ?m against W2 strain of P. falciparum and 31.62 ?m against the embryonic fibroblast cell line (cytotoxicity) displayed a high selective index of 143.73. PMID:24341638

Raj, Raghu; Biot, Christophe; Carrère-Kremer, Séverine; Kremer, Laurent; Guérardel, Yann; Gut, Jiri; Rosenthal, Philip J; Forge, Delphine; Kumar, Vipan

2014-05-01

423

The Variability of Ecstasy Tablets Composition in Brazil.  

PubMed

The content of ecstasy tablets has been changing over the years, and nowadays 3,4-methylenedioxymethamphetamine (MDMA) is not always present in the tablets. The aim of this study was to investigate the chemical composition in the seized tablets labeled as ecstasy. We analyzed samples from 150 different seizures made by Sao Paulo's State Police by gas chromatography-mass spectrometry. MDMA was present in 44.7% of the analyzed samples, and another twenty different active substances were identified in these tablets, such as caffeine, 2C-B, piperazines, amphetamines, phencyclidine, and others. Methamphetamine was present in 22% of these samples. The results demonstrate a huge shift in the pattern of trafficking of synthetic drugs, where MDMA has been replaced in tablets mostly by illicit psychoactive substances, in a clear attempt to bypass the law. The great variability in the tablets composition may lead to an increased risk of drug poisoning. PMID:25125149

Togni, Loraine R; Lanaro, Rafael; Resende, Rodrigo R; Costa, Jose L

2014-08-14

424

Synthesis, characterization and antiinflammatory-analgesic properties of 6-(alpha-amino-4-chlorobenzyl)thiazolo [3,2-b]-1,2,4-triazol-5-ols.  

PubMed

A series of 6-(alpha-amino-4-chlorobenzyl)-thiazolo[3,2-b]-1,2,4-triazol-5-ols (2a-j) were synthesized from 6-(4-chlorobenzylidene) thiazolo[3,2-b]-1,2,4-triazolo-5(6H)-one (2) by applying Michael addition reaction. All the compounds were characterized by their melting points, elementary analysis, IR and 1H-NMR spectra and screened for their anti-inflammatory and analgesic activities. Among the derivatives compound 2i bearing 4-(4-acetylphenyl)piperazine showed the highest and dose-dependent analgesic and anti-inflammatory activity without inducing any gastric lesion. PMID:14979607

Tozkoparan, Birsen; Gökhan, Nesrin; Küpeli, Esra; Ye?ilada, Erdem; Ertan, Mevlüt

2004-01-01

425

Synthesis and structure-activity relationship study of 8-hydroxyquinoline-derived Mannich bases as anticancer agents.  

PubMed

To continue our early study on the structural modifications of clioquinol, more 8-hydroxyquinoline-derived Mannich bases were synthesized and examined for growth-inhibitory effect. Taken Mannich base 1 as our lead compound, upon replacement of either sulfonyl group with methylene group or piperazine ring with ethylenediamine group resulted in an appreciable increase in potency. On the other hand, as 8-hydroxyquinoline was replaced with phenol, 3-hydroxypyridine and 1-naphthol, a dramatic decrease in activity was observed, indicating that 8-hydroxyquinoline is a crucial scaffold for activity. Further 3D-QSAR analysis on HeLa cells revealed that both steric and electronic effects contributed equally to growth inhibition. Taken together, the structure-activity relationships obtained from both in vitro data and CoMFA model warrant a valuable reference for further study. PMID:20359788

Shaw, Arthur Y; Chang, Chun-Yi; Hsu, Mei-Yuan; Lu, Pei-Jung; Yang, Chia-Ning; Chen, Hui-Ling; Lo, Cheng-Wei; Shiau, Chung-Wai; Chern, Ming-Kai

2010-07-01

426

Synthesis and biological evaluation of norcantharidin derivatives as protein phosphatase-1 inhibitors.  

PubMed

Cantharidin and norcantharidin display anticancer activity against a broad range of tumor cell lines. In this study, we have synthesized a series of norcantharidin derivatives and evaluated their cytotoxic effects on four human tumor cell lines together with the genetically normal human diploid fibroblast line WI-38. One of our compounds (1S,4R)-3-((4-(4-(4-fluorophenyl)piperazin-1-ylsulfonyl) phenyl)carbamoyl)-7-oxa-bicyclo[2.2.1]heptane-2-carboxylic acid (12) exhibited potent cytotoxic effects on the tumor cell lines A-549, HepG2, HeLa, and HCT-8, whereas it was less toxic to WI-38 cells than its parent compound, norcantharidin. In addition, this compound inhibited protein phosphatase-1 activity and microtubule formation in HeLa cells, and it also interacts with calf thymus DNA. PMID:25466711

Zhao, Jie; Guan, Xiao-Wen; Chen, Shi-Wu; Hui, Ling

2015-01-15

427

Commentary: Doxasozin for alcoholism.  

PubMed

Recent preclinical and clinical evidence using prazosin indicates that ?(1) -blockade may represent a new approach to treat alcohol dependence (AD). While most of the alcohol research on ?(1) -blockade has been conducted testing prazosin, O'Neil and colleagues recently performed a set of preclinical experiments testing another ?(1) -blocker, doxazosin, which has a longer half-life that may enhance clinical utility. Doxazosin and prazosin share the same chemical structure, in which the central element is a piperazine ring. O'Neil and colleagues' main results are that doxazosin significantly reduced alcohol intake without affecting locomotor activity. As such, O'Neil and colleagues provide the first preclinical evidence of the possible role of doxazosin in AD. Additional translational research is needed to further test this hypothesis. PMID:23278505

Leggio, Lorenzo; Kenna, George A

2013-02-01

428

Imidazolopiperazines: Lead Optimization of the Second-Generation Antimalarial Agents  

PubMed Central

On the basis of the initial success of optimization of a novel series of imidazolopiperazines, a second generation of compounds involving changes in the core piperazine ring was synthesized to improve antimalarial properties. These changes were carried out to further improve the potency and metabolic stability of the compounds by leveraging the outcome of a set of in vitro metabolic identification studies. The optimized 8,8-dimethyl imidazolopiperazine analogues exhibited improved potency, in vitro metabolic stability profile and, as a result, enhanced oral exposure in vivo in mice. The optimized compounds were found to be more efficacious than the current antimalarials in a malaria mouse model. They exhibit moderate oral exposure in rat pharmacokinetic studies to achieve sufficient multiples of the oral exposure at the efficacious dose in toxicology studies. PMID:22524250

2012-01-01

429

A divalent quaternary alkyl ammonium salt as the electrolyte for high-energy electric double-layer capacitors  

NASA Astrophysics Data System (ADS)

A divalent electrolyte salt based on 1,1,4,4-tetramethyl piperazine has been synthesized and applied in electric double-layer capacitors (EDLCs). Traits of the divalent salts have been accessed as well as monovalent quaternary alkyl ammonium salts by the means of galvanostatic charge-discharge tests and ionic conductivity measurements. Compared with monovalent salts, the divalent salts do enlarge the charge storage ability of EDLCs remarkably. However, highly concentrated charge density on the divalent cation has a strong interaction with the organic solvent of propylene carbonate. The adverse effect of this heavy solvation on the performance of EDLCs has been investigated. Moreover, the influence of pore size distribution on the storage ability of these cations at the porous carbon electrode has been addressed.

Zheng, Cheng; Yoshio, Masaki; Qi, Li; Wang, Hongyu

2012-12-01

430

Synthesis of 2,5,7,9-tetranitro-tetraazabicyclo(4,3,0)nonanone (K56) and derivatives  

SciTech Connect

Nitramines of azaheterocycles are dense highly energetic molecules used in propellants, explosives and pyrotechnics. The most famous one is the eight-membered ring with four S-NO2 functionalities (HMX) and for the past four decades, HMX has been the standard against which any other new energetic compound is compared. The non nitrated polycyclic structure was synthesized for the first time by acid-promoted condensation of ureas with 1,4-diformyl-2,3-dihydroxypiperazine. Different operating conditions leading to two-, tri-, and tetranitroderivatives are discussed. Nitration of the polycycle can occur first at the piperazine nitrogens and successive further nitration leads to tri-and tetranitroderivatives. Pure K56 can be directly obtained in one nitration step.

Graindorge, H.R.; Lescrop, P.A. [Centre de Recherches du Bouchet, Vert le Petit (France)

1995-12-01

431

Synthesis and biological evaluation of derivatives of 4-deoxypodophyllotoxin as antitumor agents.  

PubMed

In an attempt to generate compounds with superior bioactivity and reduced toxicity, a series of derivatives of deoxypodophyllotoxin were synthesized by reacting 4'-demethyl-4-deoxypodophyllotoxin with substituted piperazines or their amino acid amides. The cytotoxic activity of these compounds against three human cancer cell lines was evaluated. We found that p-nitrophenylpiperazine substitution (Compound 8b) led to an increase in the potency of the compound. Compound 8b exhibited the most potent cytotoxicity against A-549, HeLa and SiHa cells (IC(50) values were 0.102, 0.180 and 0.0195 ?M, respectively). In addition, flow cytometric analysis showed that 8b induced cell cycle arrest in the G1 phase accompanied by apoptosis in A-549 cells. PMID:21733601

Jin, Yan; Liu, Jie; Huang, Wen-Ting; Chen, Shi-Wu; Hui, Ling

2011-09-01

432

Powder X-ray study of racemic (2RS,3RS)-5-amino-3-(4-phenylpiperazin-1-yl)-1,2,3,4-tetrahydronaphthalen-2-ol.  

PubMed

The title compound, C(20)H(25)N(3)O, an important precursor for the preparation of benzovesamicol analogues for the diagnosis of Alzheimer's disease, has been synthesized and characterized by FT-IR, and (1)H and (13)C NMR spectroscopic analyses. The crystal structure was analysed using powder diffraction as no suitable single crystal was obtained. The piperazine ring has a chair conformation, while the cyclohexene ring assumes a half-chair conformation. The crystal packing is mediated by weak contacts, principally by complementary intermolecular N-H···O hydrogen bonds that connect successive molecules into a chain. Further stabilization is provided by weak C-H···N contacts and by a weak intermolecular C-H···? interaction. PMID:21979971

Assaad, Thaer; Rukiah, Mwaffak

2011-10-01

433

Antimicrobial and Hypoglycemic Activities of Novel N-Mannich Bases Derived from 5-(1-Adamantyl)-4-substituted-1,2,4-triazoline-3-thiones  

PubMed Central

The reaction of 5-(1-adamantyl)-4-ethyl or allyl-1,2,4-triazoline-3-thione with formaldehyde solution and various 1-substituted piperazines yielded the corresponding N-Mannich bases. The newly synthesized N-Mannich bases were tested for in vitro inhibitory activities against a panel of Gram-positive and Gram-negative bacteria and the yeast-like pathogenic fungus Candida albicans. Six compounds showed potent antibacterial activity against one or more of the tested microorganisms, while two compounds exhibited moderate activity against the tested Gram-positive bacteria. None of the newly synthesized compounds were proved to possess marked activity against Candida albicans. The oral hypoglycemic activity of six compounds was determined in streptozotocin (STZ)-induced diabetic rats. Four compounds produced significant strong dose-dependent reduction of serum glucose levels, compared to gliclazide at 10 mg/kg dose level (potency ratio > 75%). PMID:25514407

Al-Abdullah, Ebtehal S.; Al-Tuwaijri, Hanaa M.; Hassan, Hanan M.; Haiba, Mogedda E.; Habib, Elsayed E.; El-Emam, Ali A.

2014-01-01

434

Syntheses, characterization and evaluation of novel 2,6-diarylpiperidin-4-ones as potential analgesic-antipyretic agents.  

PubMed

A novel series of N-(N-methylpiperazinoacetyl)-2,6-diarylpiperidin-4-one derivatives (1c-3c and 5c) were synthesized, via base catalyzed nucleophilic substitution of N-chloroacetyl-2,6-diarylpiperidin-4-ones (1b-6b) with N-methyl piperazine. The newly synthesized compounds were characterized by FTIR, Mass and NMR spectral studies. All the compounds were screened for their possible analgesic and antipyretic activities. The compound 2c exhibited promising antipyretic activity, comparable to that of paracetamol at 60 mg/kg dose. The compounds 2b and 2c showed significant analgesic profile at a dose of 60 mg/kg and were also found to be more potent than the reference drug, diclofenac sodium. Thus, it can be concluded that the synthesized 2,6-diarylpiperidin-4-ones exhibit promising antipyretic and analgesic activities and could be potential drug candidates. PMID:24929294

Tripathi, Purnima; Tripathi, Avinash C; Chawla, Viney; Saraf, Shailendra K

2014-07-23

435

The subtype-selective ? 2-adrenoceptor antagonists BRL 44408 and ARC 239 also recognize 5HT 1A receptors in the rat brain  

Microsoft Academic Search

Several ?2-adrenoceptor compounds have been reported to recognize 5-HT1A receptors. The interaction of the ?2A\\/D- and ?2B\\/C-adrenoceptor antagonists BRL 44408 (2-[2H-(1-methyl-1,3-dihydroisoindole) methyl]-4,5-dihydroimidazole) and ARC 239 (2-[2-[4-(o-methoxyphenyl)piperazin-1-yl] ethyl]-4,4-dimethyl-1,3-(2H,4H)-isoquinolinedione) with 5-HT1A receptors was evaluated in rat brain. Competition experiments in cortex with both compounds against the specific binding of the 5-HT1A receptor radioligand [3H]8-OH-DPAT (8-hydroxy-2-(n-dipropyl-amine)-tetralin) yielded Ki values in the nanomolar range,

J. Javier Meana; Luis F. Callado; Angel Pazos; Bernardo Grijalba; Jesús A. García-Sevilla

1996-01-01

436

Antimicrobial and Hypoglycemic Activities of Novel N-Mannich Bases Derived from 5-(1-Adamantyl)-4-substituted-1,2,4-triazoline-3-thiones.  

PubMed

The reaction of 5-(1-adamantyl)-4-ethyl or allyl-1,2,4-triazoline-3-thione with formaldehyde solution and various 1-substituted piperazines yielded the corresponding N-Mannich bases. The newly synthesized N-Mannich bases were tested for in vitro inhibitory activities against a panel of Gram-positive and Gram-negative bacteria and the yeast-like pathogenic fungus Candida albicans. Six compounds showed potent antibacterial activity against one or more of the tested microorganisms, while two compounds exhibited moderate activity against the tested Gram-positive bacteria. None of the newly synthesized compounds were proved to possess marked activity against Candida albicans. The oral hypoglycemic activity of six compounds was determined in streptozotocin (STZ)-induced diabetic rats. Four compounds produced significant strong dose-dependent reduction of serum glucose levels, compared to gliclazide at 10 mg/kg dose level (potency ratio > 75%). PMID:25514407

Al-Abdullah, Ebtehal S; Al-Tuwaijri, Hanaa M; Hassan, Hanan M; Haiba, Mogedda E; Habib, Elsayed E; El-Emam, Ali A

2014-01-01

437

Pyrroloquinoxaline derivatives as high-affinity and selective 5-HT(3) receptor agonists: synthesis, further structure-activity relationships, and biological studies.  

PubMed

The synthesis, pharmacological evaluation, and structure-activity relationships (SARs) of a series of novel pyrroloquinoxalines and heteroaromatic-related derivatives are described. The new pyrroloquinoxaline-related ligands were tested in rat cortex, a tissue expressing high density of 5-HT(3) receptors, and on NG108-15 cells and exhibited IC(50) values in the low nanomolar or subnanomolar range, as measured by the inhibition of [(3)H]zacopride binding. The SAR studies detailed herein delineated a number of structural features required for improving affinity. Some of the ligands were employed as "molecular yardsticks" to probe the spatial dimensions of the lipophilic pockets L1, L2, and L3 in the 5-HT(3) receptor cleft, while the 7-OH pyrroloquinoxaline analogue was designed to investigate hydrogen bonding with a putative receptor site H1 possibly interacting with the serotonin hydroxy group. The most active pyrroloquinoxaline derivatives showed subnanomolar affinity for the 5-HT(3) receptor. In functional studies ([(14)C]guanidinium accumulation test in NG108-15 hybrid cells, in vitro) most of the tested compounds showed clear-cut 5-HT(3) agonist properties, while some others were found to be partial agonists. Several heteroaromatic systems, bearing N-substituted piperazine moieties, have been explored with respect to 5-HT(3) affinity, and novel structural leads for the development of potent and selective central 5-HT(3) receptor agonists have been identified. Preliminary pharmacokinetic studies indicate that these compounds easily cross the blood-brain barrier (BBB) after systemic administration with a brain/plasma ratio between 2 and 20, unless they bear a highly hydrophilic group on the piperazine ring. None of the tested compounds showed in vivo anxiolytic-like activity, but potential analgesic-like properties have been possibly disclosed for this new class of 5-HT(3) receptor agonists. PMID:10543880

Campiani, G; Morelli, E; Gemma, S; Nacci, V; Butini, S; Hamon, M; Novellino, E; Greco, G; Cagnotto, A; Goegan, M; Cervo, L; Dalla Valle, F; Fracasso, C; Caccia, S; Mennini, T

1999-10-21

438

Evaluation of the D3 Dopamine Receptor Selective Agonist/Partial Agonist PG01042 on L-Dopa Dependent Animal Involuntary Movements in Rats  

PubMed Central

The substituted 4-phenylpiperazine D3 dopamine receptor selective antagonist PG01037 ((E)-N-(4-(4-(2,3-dichlorophenyl)piperazin-1-yl)but-2-enyl)-4-(pyridin-2-yl)benzamide) was reported to attenuate L-dopa associated abnormal involuntary movements (AIMs) in unilaterally lesioned rats, a model of L-dopa-dependent dyskinesia in patients with Parkinson’s Disease (Kumar et al., 2009a). We now report that PG01042 (N-(4-(4-(2,3-dichlorophenyl)piperazin-1-yl)butyl)-4-(pyridin-3-yl)benzamide), which is a D3 dopamine receptor selective agonist for adenylyl cyclase inhibition and a partial agonist for mitogenesis, is also capable of attenuating AIMs scores. The intrinsic activity of PG01037 and PG01042 were determined using a) a forskolin-dependent adenylyl cyclase inhibition assay and b) an assay for agonist-associated mitogenesis. It was observed that the in vivo efficacy of PG01042 increased when administered by intraperitoneal (i.p.) injection simultaneously with L-dopa/benserazide (8 mg/kg each), as compared to a 60 minute or 30 minute pretreatment. PG01042 was found to attenuate AIM scores in these animals in a dose dependent manner. While PG01042 did not effectively inhibit SKF 81297-dependent AIMs, it inhibited apomorphine-dependent AIM scores. Rotarod studies indicate that PG01042 at a dose of 10 mg/kg did not adversely affect motor coordination of the unilaterally lesioned rats. Evaluation of lesioned rats using a cylinder test behavioral paradigm indicated that PG01042 did not dramatically attenuate the beneficial effects of L-dopa. These studies and previously published studies suggest that both D3 dopamine receptor selective antagonists, partial agonists and agonists, as defined by an adenylyl cyclase inhibition assay and a mitogenic assay, are pharmacotherapeutic candidates for the treatment of L-dopa-associated dyskinesia in patients with Parkinson’s Disease. PMID:20850462

Riddle, Lindsay R.; Kumar, Rakesh; Griffin, Suzy A.; Grundt, Peter; Newman, Amy Hauck; Luedtke, Robert R.

2013-01-01

439

Effects of 5-HT uptake inhibitors, agonists and antagonists on the burying of harmless objects by mice; a putative test for anxiolytic agents.  

PubMed Central

1. The effects of 5-hydroxytryptamine (5-HT) uptake inhibitors, agonists and antagonists have been evaluated on mouse marble-burying behaviour, a putative test for anxiolytic agents. The high levels of locomotor activity occurring on first exposure to a circular runway (runway were used as a separate test of non-specific drug effects. 2. Fluvoxamine, zimeldine, indalpine and citalopram dose-dependently inhibited burying without affecting runway activity. 5-Hydroxytryptophan (5-HTP, with carbidopa), 5-methoxy-N,N-dimethyltryptamine, 8-hydroxy-2-(di-n-propylamino) tetralin (8-OHDPAT), buspirione, gepirone and ipsapirone reduced burying only at doses reducing runway activity. RU 24969 increased runway activity at all effective doses. 1-(2,5-Dimethoxy-4-iodophenyl)-2-aminopropane (DOI), 1,-(3-trifluoromethylphenyl) piperazine (TFMPP) and 1-(3-chlorophenyl)-piperazine (mCPP) potently and differentially reduced burying at doses below those affecting runway activity. 3. 5-HT antagonists only reduced burying at high doses which also reduced runway activity. Burying inhibition by DOI was antagonized by ritanserin, ICI 169,369 and cyproheptadine but not by pindolol or a low (0.25 mg kg-1) dose of metergoline. Burying inhibition by mCPP was not altered by any of these agents except that it was potentiated by pindolol 5 mg kg-1. 4. Zimeldine burying inhibition was potentiated by ritanserine, ICI 169,369, ICS 205-930, cyproheptadine and pindolol. Runway activity was not affected by these drug combinations. 5. Zimeldine was administered in drinking water at a dose of 10 mg kg-1 daily for 21 days.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1686200

Njung'e, K.; Handley, S. L.

1991-01-01

440

MOLECULAR ANALYSIS AND MODELING OF INACTIVATION OF HUMAN CYP2D6 BY FOUR MECHANISM BASED INACTIVATORS  

PubMed Central

Human cytochrome P450 2D6 (CYP2D6) is involved in metabolism of approximately 25% of pharmaceutical drugs. Inactivation of CYP2D6 can lead to adverse drug interactions. Four inactivators of CYP2D6 have previously been identified: 5-Fluoro-2-[4-[(2-phenyl-1H-imidazol-5-yl)methyl]-1-piperazinyl]pyrimidine (SCH66712), (1-[(2-ethyl-4-methyl-1H(-EMTPP-imidazol-5-yl)-methyl]-4-[4-(trifluoromethyl)-2-pyridinyl]piperazine (EMTPP), paroxetine, and 3,4-methylenedioxymethamphetamine (MDMA). All four contain planar, aromatic groups as well as basic nitrogens common to CYP2D6 substrates. SCH66712 and EMTPP also contain piperazine groups and substituted imidazole rings that are common in pharmaceutical agents, though neither of these compounds is clinically relevant. Paroxetine and MDMA contain methylenedioxyphenyls. SCH66712 and EMTPP are both known protein adductors while paroxetine and MDMA are probable heme modifiers. The current study shows that each inactivator displays Type I binding with Ks values that vary by 2-orders of magnitude with lower Ks values associated with greater inactivation. Comparison of KI, kinact, and partition ratio values shows SCH66712 is the most potent inactivator. Molecular modeling experiments using AutoDock identify Phe120 as a key interaction for all four inactivators with face-to-face and edge-to-face pi interactions apparent. Distance between the ligand and heme iron correlates with potency of inhibition. Ligand conformations were scored according to their binding energies as calculated by AutoDock and correlation was observed between molecular models and Ks values. PMID:22372551

Livezey, Mara; Nagy, Leslie D.; Diffenderfer, Laura E.; Arthur, Evan J.; Hsi, David J.; Holton, Jeffrey M.; Furge, Laura Lowe

2014-01-01

441

Synthesis and characterization of novel "3 + 2" oxorhenium complexes, ReO[SNO][NN].  

PubMed

The present paper deals with the synthesis and structural characterization of novel neutral oxorhenium(V) complexes of the general formula ReO[SNO][NN]. The simultaneous action of the tridentate SNO ligand, N-(2-mercaptoacetyl)glycine (1), and the bidentate NN ligand, N-phenylpyridine-2-aldimine (2), on ReOCl3(PPh3)2 leads to the formation of two isomers 4a and 4b of the general formula ReO[SNO][NN], as a result of the different orientations of the NN ligand. In both cases, the SNO donor atoms of the tridentate ligand occupy the three positions in the equatorial plane of the distorted octahedron, whereas the oxo group is always directed toward one of the apical positions. In the first isomer, 4a, the imino nitrogen of the NN ligand occupies the fourth equatorial position and the pyridine type nitrogen is directed trans to the oxo group, while in the second isomer, 4b, the imino nitrogen of the NN ligand occupies the apical position trans to the oxo group and the pyridine type nitrogen completes the equatorial plane of the distorted octahedron. The [SNO][NN] mixed-ligand system was applied in the synthesis of the oxorhenium complex 5 in which the 1-(2-methoxyphenyl)piperazine moiety, a fragment of the true 5-HT1A antagonist WAY 100635, has been incorporated in the NN bidentate ligand (NN is N-{3-[4-(2-methoxyphenyl)piperazin-1-yl]propyl}pyridine-2-aldimine). In this case, high-performance liquid chromatography and NMR showed the existence of one isomer, 5, in which the pyridine nitrogen is trans to the oxo core, as demonstrated by crystal structure analysis. PMID:16813429

Chiotellis, Aris; Tsoukalas, Charalambos; Pelecanou, Maria; Papadopoulos, Apostolos; Raptopoulou, Catherine; Terzis, Aris; Pirmettis, Ioannis; Papadopoulos, Minas; Chiotellis, Efstratios

2006-07-10

442

Theoretical and experimental studies of the isomeric protonation in solution for a prototype aliphatic ring containing two nitrogens  

PubMed Central

Theoretical calculations were carried out for studying the tautomeric protonation of N-methyl piperazine as a prototype six-member aliphatic ring containing a secondary and a tertiary nitrogen atom. The protonation was investigated in three solvents: water, acetonitrile, and dichloromethane. Calculations were performed up to the B3LYP/aug-cc-pvtz and QCISD(T)/CBS levels by applying the IEF-PCM polarizable continuum dielectric solvent model. Relative solvation free energies also were calculated upon explicit solvent models by utilizing the free-energy perturbation theory as implemented in Monte Carlo simulations. The relative free energy for the N-methyl piperazine tautomer protonated at the secondary (NMps) rather than at the tertiary (NMpt) nitrogen was calculated at a ratio of 47/53 in infinitely dilute aqueous solution. The ratio further decreases in lower polarity solvents. In contrast, NMR experiments suggest that the protonation takes place primarily at the secondary nitrogen in 0.37 molar aqueous solution with NMps/NMpt = 80/20. The NMps tautomer is exclusive in dichloromethane at the same concentration. The discrepancy between theory and experiment was resolved by considering association equilibria in parallel with the protonation for the solute. As a result, the theoretically predicted tautomer ratios were obtained in close agreement with the experimental values. The NMps tautomer could form a preferable dimeric structure, where one or two chloride anion(s) is/are in hydrogen bonds with protons of the associating monomers. The calculations suggest that the proton relocation may take place by solvent assistance in water or along an intramolecular proton jump in the twist-boat conformation. The predicted activation free energy was about 10 kcal/mol on the basis of variable temperature NMR experiments in DCM. PMID:19994881

Maheshwari, Aditya; Kim, Yong-Wah

2009-01-01

443

A novel trifluoromethyl benzopyran induces G1 cell cycle arrest and apoptosis in HeLa human cervical carcinoma cells.  

PubMed

In the present study, a biologically active 4-(trifluoromethyl)phenyl piperazin moiety was linked to a 2,2- dimethyl -2H-benzopyran template to generate (3R,4S)-2,2-dimethyl-6-nitro-4-(4-(3-(trifluoromethyl)phenyl)piperazin-1-yl) chroman -3-ol (C110g), and the cellular and molecular mechanisms by which C110g exerts cytotoxic effects on the HeLa human cervical cancer cell line were further investigated. C110g suppressed the viability of HeLa cells in both concentration- and time-dependent manner (IC50 of 17 µM) by inducing DNA damage and G1 cell cycle arrest. Characteristic changes in nuclear morphology and Annexin V/PI staining pointed to apoptosis as the mode of cell death. The levels of p53 and p21 were increased in the C110g-treated cells, with a corresponding increase in Bax/Bcl-2 protein ratio. Subsequently, C110g induced the cytoplasmic release of cytochrome c from the mitochondria accompanied by a decreased mitochondrial membrane potential and activation of caspase-3 and -9. These results confirmed that the C110g transduced the apoptotic signal via the mitochondrial pathway. Caspase-8, typically associated with the initiation of the death receptor pathway, was activated, suggesting the extrinsic pathway might also be involved. However, C110g did not result in reactive oxygen species (ROS) generation. Taken together, these findings indicate that the DNA damage-dependent p53-regulated mitochondrial pathway as well as the extrinsic pathway play a crucial role in C110g-induced apoptosis, which provide a better understanding of the molecular mechanisms of trifluoromethyl benzopyrans in cervical cancer. PMID:23708884

Zhang, Xin; Hwang, Jiyoung; Jia, Xian; Shin, Dong-Soo; You, Song; Kim, Dong-Kyoo

2013-08-01

444

Presence of illicit drugs and metabolites in influents and effluents of 25 sewage water treatment plants and map of drug consumption in France.  

PubMed

Consumption of illicit drugs is a new concern for water management that must be considered not only because of the social and public health aspects but also in an environmental context in relation with the contamination of surface waters. Indeed, sewage treatment plant (STP) effluents contain drug residues that have not been eliminated since STP treatments are not completely efficient in their removal. We developed and validated an HPLC-MS/MS analytical method to assess the concentrations of 17 illicit drugs and metabolites in raw urban wastewaters: cocaine and its metabolites, amphetamine and amphetamine-likes (methamphetamine, MDMA, MDEA, MDA), opiates and opiate substitutes (methadone and buprenorphine), and THC-COOH cannabis metabolite. This method has been applied to the analysis of influent and effluent samples from 25 STPs located in France all over the country. The results allowed evaluating the drug consumption in the areas connected to the STPs and the efficiency of the treatment technology implied. We selected STPs according to their volume capacity, their treatment technologies (biofilters, activated sludges, MBR) and their geographical location. In influents, the concentrations varied between 6 ng/L for EDDP (main metabolite of methadone) and 3050 ng/L for benzoylecgonine (cocaine metabolite). Consumption maps were drawn for cocaine, MDMA, opiates, cannabis and amphetamine-like compounds. Geographical significant differences were observed and highlighted the fact that drug consumption inside a country is not homogeneous. In parallel, comparisons between STP technology processes showed differences of efficiency. More, some compounds appear very resistant to STP processes leading to the contamination of receiving water. PMID:23770552

Nefau, Thomas; Karolak, Sara; Castillo, Luis; Boireau, Véronique; Levi, Yves

2013-09-01

445

Evaluation of haloalkaliphilic sulfur-oxidizing microorganisms with potential application in the effluent treatment of the petroleum industry.  

PubMed

Haloalkaliphilic sulfur-oxidizing mixed cultures for the treatment of alkaline-saline effluents containing sulfide were characterized and evaluated. The mixed cultures (IMP-PB, IMP-XO and IMP-TL) were obtained from Mexican alkaline soils collected in Puebla (PB), Xochimilco (XO) and Tlahuac (TL), respectively. The Ribosomal Intergenic Spacer Analysis (RISA) revealed bacteria related to Thioalkalibacterium and Thioalkalivibrio in IMP-XO and IMP-PB mixed cultures. Halomonas strains were detected in IMP-XO and IMP-TL. In addition, an uncultured Bacteroides bacterium was present in IMP-TL. Mixed cultures were evaluated at different pH and NaCl concentrations at 30°C. IMP-PB and IMP-TL expressed thiosulfate-oxidizing activity in the 7.5-10.5 pH range, whereas IMP-XO presented its maximal activity with 19.0 mg O? g (protein)?¹ min?¹, at pH 10.6; it was not affected by NaCl concentrations up to 1.7 M. In continuous culture, IMP-XO showed a growth rate of 15 day?¹, productivity of 433.4 mg(protein) l?¹ day?¹ and haloalkaliphilic sulfur-oxidizing activity was also detected up to 170 mM by means of N-methyl-diethanolamine (MDEA). Saline-alkaline soil samples are potential sources of haloalkaliphilic sulfur-oxidizing bacteria and the mixed cultures could be applied in the treatment of inorganic sulfur compounds in petroleum industry effluents under alkaline-saline conditions. PMID:20582453

Olguín-Lora, P; Le Borgne, S; Castorena-Cortés, G; Roldán-Carrillo, T; Zapata-Peñasco, I; Reyes-Avila, J; Alcántara-Pérez, S

2011-02-01

446

Assessment of synergistic combination potential of probiotic and bacteriophage against antibiotic-resistant Staphylococcus aureus exposed to simulated intestinal conditions.  

PubMed

This study was designed to evaluate the combined effect of probiotic Lactobacillus rhamnosus and bacteriophage SA11 on the control of antibiotic-sensitive Staphylococcus aureus (ASSA) and antibiotic-resistant S. aureus (ARSA) under the simulated intestinal conditions. The survivability of ASSA and ARSA were determined in the simulated phosphate-buffered saline (PBS)-, trypticase soy broth (TSB)-, and milk-based gastric juices adjusted to pH 2.0, 3.0, and 5.0 at 37 °C for 30 min. The inhibitory effect of bacteriophage SA11 and probiotic on the growth of ASSA and ARSA was evaluated in the simulated intestinal juices at 37 °C for 20 h. The least reductions in the numbers of ASSA and ARSA were observed in the milk-based gastric juices at pH 2.0 (<1 log). No significant changes in the teichoic acid-mediated sliding motility were observed for ASSA and ARSA after 30-min exposure to the simulated gastric juices (pH 2.0, 3.0, and 5.0), responsible for the enhanced bacterial attachment to the epithelial cells. The bacteriophage SA11 was stable down to pH 5.0 and up to 0.06 % bile salts. The bacteriophage SA11 combined with probiotic effectively inhibited the growth of ASSA and ARSA in the simulated intestinal conditions, showing more than 4 log reduction. The relative expression levels of adhesion-related genes (clfA, eno, and fnbA) and efflux-related genes (mdeA, norB, and norC) were less decreased in ARSA than in ASSA after exposure to the simulated gastrointestinal conditions. These results might shed light on the application of bacteriophage to control the ingested antibiotic-resistant foodborne pathogens in the intestinal tract. PMID:25015717

Woo, Jihoon; Ahn, Juhee

2014-10-01

447

Metabolism-dependent mutagenicity of a compound containing a piperazinyl indazole motif: Role of a novel p450-mediated metabolic reaction involving a putative oxaziridine intermediate.  

PubMed

Compound 1a (6-chloro-5-{3-[4-(1H-indazol-3-yl)-piperazin-1-yl]-propyl}-3,3-dimethyl-1,3-dihydro-indol-2-one) was mutagenic to Salmonella typhimurium TA98 in the presence of rat liver S9 subcellular fraction. The metabolism of 1a in rat liver S9 or microsomes demonstrated that it underwent a P450-mediated N-deindazolation (loss of indazole ring) as a predominant metabolic pathway. To investigate a possible link between metabolism and mutagenicity, a structural analogue 1b (6-chloro-5-{3-[4-(1H-indazol-3-yl)-piperidin-1-yl]-propyl}-3,3-dimethyl-1,3-dihydro-indol-2-one), the cleaved product 2a (6-chloro-3,3-dimethyl-5-(3-piperazin-1-yl-propyl)-1,3-dihydro-indol-2-one), and the core motif 3a (3-piperazinyl indazole) were evaluated in the Ames assay. It was found that 1b was not mutagenic to Salmonella typhimurium TA98 in the absence or presence of a metabolic activating system. In contrast to 1a, 1b did not undergo the metabolic cleavage (loss of indazole ring). Marginal mutagenicity of 2a to TA98 was observed with rat liver S9, whereas 3a was shown to be a promutagen. It was further demonstrated that 1a inactivated P450 3A, the principle enzyme catalyzing the N-deindazolation reaction, in an NADPH-, time-, and concentration-dependent manner. The kinetics of inactivation was characterized by a K(I) of 8.1 microM and k(inact) of 0.114 min(-1). The differences in mutagenicity between 1a and 1b suggest that a chemical bond extending from the 3-position of the indazole to a heteroatom (as part of another cyclic ring) is a prerequisite for the toxicity. The metabolic process leading to the elimination of the indazole from the rest of the molecule apparently plays a key role in causing mutagenicity. It is postulated that the N-deindazolation of 1a proceeds via an oxaziridine intermediate, the formation of which is indirectly inferred from the presence of benzoic acid in microsomal incubations. Benzoic acid is thought to be derived from the hydrolysis of 3-indazolone, an unstable product generated from the oxaziridine. Evidence suggests that the electrophilic oxaziridine intermediate may be responsible for the mutagenicity and inactivation of P450 3A. PMID:17040103

Chen, Hao; Murray, Joel; Kornberg, Brian; Dethloff, Lloyd; Rock, David; Nikam, Sham; Mutlib, Abdul E

2006-10-01

448

Hydrothermal synthesis, crystal structure, thermal behavior and spectroscopic and magnetic properties of two new organically templated fluoro-vanadyl-hydrogenarsenates: (R){sub 0.5}[(VO)(HAsO{sub 4})F] (R: Ethylenediammonium and piperazinium)  

SciTech Connect

Two new fluoro-vanadyl-hydrogenarsenate compounds templated by ethylenediamine and piperazine with formula, (C{sub 2}N{sub 2}H{sub 10}){sub 0.5}[(VO)(HAsO{sub 4})F] (1) and (C{sub 4}N{sub 2}H{sub 12}){sub 0.5}[(VO)(HAsO{sub 4})F] (2), respectively, have been synthesized by using mild hydrothermal conditions under autogenous pressure. The crystal structures have been solved from single-crystal X-ray diffraction data. The phases crystallize in the P2{sub 1}/c monoclinic space group with the unit-cell parameters a=7.8634(4) A, b=7.7658(4) A, c=10.4195(6) A, {beta}=101.524(5){sup o} for compound (1) and a=6.301(1) A, b=10.244(1) A, c=10.248(1) A and {beta}=95.225(1){sup o} for compound (2). These phases exhibit a layered inorganic framework. In both cases, the structure is built from secondary building units (SBU) which are formed by [V{sub 2}O{sub 8}F{sub 2}] edge-shared dimeric vanadyl octahedra, connected by the vertices to two hydrogenarsenate tetrahedra. The repetition of this SBU unit originates sheets along the [1 0 0] direction. The ethylenediammonium and piperazinium cations are located inside the interlayer space. The limit of thermal stability for compounds (1) and (2) is, approximately, 250 and 230 deg. C, respectively. Near this temperature, both phases loose their organic cations and the fluoride anions. The diffuse reflectance spectra confirm the presence of vanadyl ions, in which the vanadium(IV) cations have a d{sup 1} electronic configuration in a slightly distorted octahedral environment. ESR spectra of both phases are isotropic with mean g-values of 1.93 and 1.96 for ethylendiamine and piperazine phases, respectively. Magnetic measurements for (1) and (2) indicate the existence of antiferromagnetic exchange couplings. - Graphical abstract: Polyhedral view of the layered crystal structure of (C{sub 2}H{sub 10}N{sub 2}){sub 0.5} [(VO)(HAsO{sub 4})F].

Berrocal, Teresa [Departamento de Mineralogia y Petrologia, Facultad de Ciencia y Tecnologia, Universidad del Pais Vasco/EHU Apdo. 644, E-48080 Bilbao (Spain); Mesa, Jose L. [Departamento de Quimica Inorganica, Facultad de Ciencia y Tecnologia, Universidad del Pais Vasco/EHU Apdo. 644, E-48080 Bilbao (Spain)], E-mail: joseluis.mesa@ehu.es; Pizarro, Jose L. [Departamento de Mineralogia y Petrologia, Facultad de Ciencia y Tecnologia, Universidad del Pais Vasco/EHU Apdo. 644, E-48080 Bilbao (Spain); Lezama, Luis [Departamento de Quimica Inorganica, Facultad de Ciencia y Tecnologia, Universidad del Pais Vasco/EHU Apdo. 644, E-48080 Bilbao (Spain); Bazan, Begona; Arriortua, Maria I. [Departamento de Mineralogia y Petrologia, Facultad de Ciencia y Tecnologia, Universidad del Pais Vasco/EHU Apdo. 644, E-48080 Bilbao (Spain); Rojo, Teofilo [Departamento de Quimica Inorganica, Facultad de Ciencia y Tecnologia, Universidad del Pais Vasco/EHU Apdo. 644, E-48080 Bilbao (Spain)

2008-04-15

449

Understanding the availability, prevalence of use, desired effects, acute toxicity and dependence potential of the novel opioid MT-45.  

PubMed

Abstract Introduction. 1-Cyclohexyl-4-(1,2-diphenylethyl)piperazine (MT-45) is a novel psychoactive substance available over the Internet. MT-45 is an opioid-like compound. This study provides an overview of availability, use and desired and unwanted effects of MT-45 through triangulation of available data sources. Methods. Searches of the published scientific literature and 'grey' information sources, using the keywords 'MT 45', 'MT-45' and '1-cyclohexyl-4-(1,2-diphenylethyl)piperazine' were undertaken in June 2014 to identify information on the availability, prevalence of use and desired/unwanted effects of MT-45. In addition an Internet snapshot survey in English was undertaken in May 2014 to determine the availability and cost of MT-45. Results. In June 2014 we were unable to identify any studies reporting the prevalence of use of MT-45. The Internet snapshot study identified 17 Internet sites selling MT-45. Information on price was available from 9 sites, with the mean price of MT-45 decreased with increasing purchase amounts from US$57.60 ± 19.37 per gram for a 1-g purchase to US$3.36 ± 1.83 per gram for a 1-kg purchase. We identified one published scientific paper reporting on the acute harms in nine cases of analytically confirmed MT-45 toxicity, one US government report relating to two MT-45-related deaths and 20 user reports on Internet discussion forums relating to the use of MT-45. All these suggest that the desired and unwanted effects of MT-45 are similar to those seen with other opioids, and that the opioid-like unwanted effects may be reversed with the opioid antagonist naloxone. There were user reports of MT-45 being used in heroin withdrawal and of 'withdrawal symptoms' after use, suggesting that long-term use may be associated with dependency as seen with other opioids. Conclusions. Combining published scientific literature and 'grey' information sources, we have demonstrated that MT-45 has opioid-like desired and unwanted effects. Whilst the information is limited at the moment, it has the potential to have similar dependence liability to other opioids. PMID:25430506

Siddiqi, Sindhu; Verney, Charlotte; Dargan, Paul; Wood, David M

2015-01-01

450

Combinatorial synthesis of chemically diverse core-shell nanoparticles for intracellular delivery  

PubMed Central

Analogous to an assembly line, we employed a modular design for the high-throughput study of 1,536 structurally distinct nanoparticles with cationic cores and variable shells. This enabled elucidation of complexation, internalization, and delivery trends that could only be learned through evaluation of a large library. Using robotic automation, epoxide-functionalized block polymers were combinatorially cross-linked with a diverse library of amines, followed by measurement of molecular weight, diameter, RNA complexation, cellular internalization, and in vitro siRNA and pDNA delivery. Analysis revealed structure-function relationships and beneficial design guidelines, including a higher reactive block weight fraction, stoichiometric equivalence between epoxides and amines, and thin hydrophilic shells. Cross-linkers optimally possessed tertiary dimethylamine or piperazine groups and potential buffering capacity. Covalent cholesterol attachment allowed for transfection in vivo to liver hepatocytes in mice. The ability to tune the chemical nature of the core and shell may afford utility of these materials in additional applications. PMID:21784981

Siegwart, Daniel J.; Whitehead, Kathryn A.; Nuhn, Lutz; Sahay, Gaurav; Cheng, Hao; Jiang, Shan; Ma, Minglin; Lytton-Jean, Abigail; Vegas, Arturo; Fenton, Patrick; Levins, Christopher G.; Love, Kevin T.; Lee, Haeshin; Cortez, Christina; Collins, Sean P.; Li, Ying Fei; Jang, Janice; Querbes, William; Zurenko, Christopher; Novobrantseva, Tatiana; Langer, Robert; Anderson, Daniel G.

2011-01-01

451

Design and synthesis of novel 2H-chromen-2-one derivatives bearing 1,2,3-triazole moiety as lead antimicrobials.  

PubMed

A series of novel 2H-chromen-2-one derivatives decorated with 1,2,3-triazole moiety were designed and synthesized using the click reaction of azidoalkyloxy-2H-chromen-2-ones with different propargylamines. Propargylamines were obtained by alkylation of various heterocyclic amines with propargyl bromide. Newly synthesized compounds and intermediates were evaluated for their antifungal activity against four fungi (Aspergillus niger, Aspergillus fumigatus, Aspergillus flavus and Candida albicans). Antibacterial studies were also carried out against three Gram-positive bacteria (Staphylococcus aureus, Bacillus subtilis and Staphylococcus epidermis) and four Gram-negative bacteria (Escherichia coli, Pseudomonas aeruginosa, Salmonella typhi and Klebsiella pneumoniae). In vitro, bioassay results showed that all the synthesized compounds exhibited excellent activity against fungal strains Aspergillus fumigatus, Aspergillus flavus and Candida albicans. Interestingly, all the compounds have shown even superior activity than the reference drug miconazole against Aspergillus fumigatus. Morpholine and N-acetyl piperazine containing compounds 10c and 10e have shown promising activity against various bacterial strains. Compound 10e was found to be most active against Pseudomonas aeruginosa. Based on, in silico pharmacokinetic studies, compounds 10a-e were identified as lead compounds for future investigation due to their lower toxicity, high drug score values and good oral bioavailability as per OECD guidelines. PMID:24594353

Kushwaha, Khushbu; Kaushik, Nagendra; Lata; Jain, Subhash C

2014-04-01

452

Identification of a lead small-molecule inhibitor of the Aurora kinases using a structure-assisted, fragment-based approach.  

PubMed

Aurora A and Aurora B are potential targets for anticancer drug development due to their roles in tumorigenesis and disease progression. To identify small-molecule inhibitors of the Aurora kinases, we undertook a structure-based design approach that used three-dimensional structural models of the Aurora A kinase and molecular docking simulations of chemical entities. Based on these computational methods, a new generation of inhibitors derived from quinazoline and pyrimidine-based tricyclic scaffolds were synthesized and evaluated for Aurora A kinase inhibitory activity, which led to the identification of 4-(6,7-dimethoxy-9H-1,3,9-triaza-fluoren-4-yl)-piperazine-1-carbothioic acid [4-(pyrimidin-2-ylsulfamoyl)-phenyl]-amide. The lead compound showed selectivity for the Aurora kinases when it was evaluated against a panel of diverse kinases. Additionally, the compound was evaluated in cell-based assays, showing a dose-dependent decrease in phospho-histone H3 levels and an arrest of the cell cycle in the G(2)-M fraction. Although biological effects were observed only at relatively high concentrations, this chemical series provides an excellent starting point for drug optimization and further development. PMID:16891462

Warner, Steven L; Bashyam, Sridevi; Vankayalapati, Hariprasad; Bearss, David J; Han, Haiyong; Mahadevan, Daruka; Von Hoff, Daniel D; Hurley, Laurence H

2006-07-01

453

Sunlight-induced degradation of soil-adsorbed veterinary antimicrobials Marbofloxacin and Enrofloxacin.  

PubMed

Marbofloxacin (MAR) and Enrofloxacin (ENR), two largely employed veterinary Fluoroquinolones (FQs), were found to be present at the micrograms per kilogram level in agricultural soils of South Lombardy (Italy) several months after manuring. Distribution coefficients (K(d)) from sorption experiments indicated a strong binding to the soil. Soil samples fortified with environmentally significant FQs amounts (0.5 mg kg(-1)) were exposed to solar light that promoted extensive degradation (80%) of both drugs in 60-150 h. Thus, photochemistry could be considered a significant depollution path in the soil, although it was two orders of magnitudes slower than in aqueous solution and a fraction of the drug (ca. 20%) remained unaffected. For MAR the photoprocess was the same as in solution, and involved cleavage of the tetrahydrooxadiazine ring. On the contrary, with ENR only some of the photoproducts determined in water (those arising from a stepwise oxidation of the piperazine side chain) were observed. Substitution of the 6-fluoro by a hydroxyl group and reduction did not occur in the soil, supporting the previous contention that such processes required polar solvation of FQs. Consistently with this rationalization, the irradiation of thin layers of solid drugs led to essentially the same products distribution as in the soil. From the environmental point of view it is important to notice that photodegradation mainly affects the side-chains, while the fluoroquinolone ring, to which the biological effect is associated, is conserved up to the later stages of the degradation. PMID:22051342

Sturini, Michela; Speltini, Andrea; Maraschi, Federica; Profumo, Antonella; Pretali, Luca; Fasani, Elisa; Albini, Angelo

2012-01-01

454

Docking of 6-chloropyridazin-3-yl derivatives active on nicotinic acetylcholine receptors into molluscan acetylcholine binding protein (AChBP).  

PubMed

The crystal structure of Acetylcholine Binding Protein (AChBP), homolog of the ligand binding domain of nAChR, has been used as model for computational investigations on the ligand-receptor interactions of derivatives of 6-chloropyridazine substituted at C3 with 3,8-diazabicyclo[3.2.1]octane, 2,5-diazabicyclo[2.2.1]heptane and with piperazine and homopiperazine, substituted or not at N4. The ligand-receptor complexes have been analyzed by docking techniques using the binding site of HEPES complexed with AChBP as template. The good relationship between the observed binding affinity and the calculated docking energy confirms that this model provides a good starting point for understanding the binding domain of neuronal nicotinic receptors. An analysis of the possible factors significant for the ligand recognition has evidenced, besides the cation-pi interaction, the distance between the chlorine atom of the pyridazinyl group and the carbonylic oxygen of Leu B112 as an important parameter in the modulation of the binding energy. PMID:15848206

Artali, Roberto; Bombieri, Gabriella; Meneghetti, Fiorella

2005-04-01

455

Studies on the human metabolism and the toxicologic detection of the cough suppressant dropropizine in urine using gas chromatography-mass spectrometry.  

PubMed

Studies are described on the metabolism and the toxicologic analysis of the nonopioid cough suppressant dropropizine [R,S-3-(4-phenyl-1-piperazinyl)1,2-propandiol, DRO] in human urine using gas chromatography-mass spectrometry (GC-MS). The metabolism studies showed that DRO was metabolized in humans mainly by hydroxylation of the aromatic ring, by N-dealkylation of the parent drug and of the hydroxyl-metabolite to the corresponding N-phenylpiperazines, and by degradation of the piperazine moiety. The authors' systematic toxicologic analysis (STA) procedure using full-scan GC-MS after acid hydrolysis, liquid-liquid extraction, and microwave-assisted acetylation allowed the unambiguous detection of DRO and its above-mentioned metabolites in human urine up to about 32 hours after intake of a single common therapeutic dose. The target analytes were found to be the parent compound DRO (earlier phase of excretion) and the hydroxylated metabolite para-hydroxy-DRO (later phase of excretion). Both allowed unambiguous detection of an intake of DRO and also differentiation from other phenylpiperazine derivatives. PMID:15257075

Staack, Roland F; Theobald, Denis S; Maurer, Hans H

2004-08-01

456

Safety and toxicological profile of the new antitussive levodropropizine.  

PubMed

Levodropropizine (S(-)-3-(4-phenyl-piperazin-1-yl)-propane-1,2-diol, DF 526), a new antitussive drug, was submitted to toxicological studies. Acute toxicity, both oral and intraperitoneal, in rats and mice and oral toxicity in guinea-pigs was low. Subchronic and chronic toxicity studies were performed in rats and dogs. For both species the maximum tolerated oral dosage was 24 mg/kg/d. Dose-related clinical signs were observed, consisting mainly in salivation in rats and sedation, peripheral vasodilatation and increased heart rate in dogs. Liver toxicity was found in both species at higher dosages. In rats, food intake and body weight gain were reduced. There were no effects on fertility, nor any teratogenic effects. Foetal and peri- and post-natal toxic effects were observed in rats only at 150 mg/kg/d. A set of mutagenicity tests yielded negative results. Therefore, levodropropizine is safe up to dosages 10 times greater than the one intended for clinical use and only slight adverse reactions were recorded at a dosage 30 times greater. PMID:3196409

Bestetti, A; Giuliani, P; Nunziata, A; Melillo, G; Tonon, G C

1988-08-01

457

PITPs as Targets for Selectively Interfering With Phosphoinositide Signaling in Cells  

PubMed Central

Sec14-like phosphatidylinositol transfer proteins (PITPs) integrate diverse territories of intracellular lipid metabolism with stimulated phosphatidylinositol-4-phosphate production, and are discriminating portals for interrogating phosphoinositide signaling. Yet, neither Sec14-like PITPs, nor PITPs in general, have been exploited as targets for chemical inhibition for such purposes. Herein, we validate the first small molecule inhibitors (SMIs) of the yeast PITP Sec14. These SMIs are nitrophenyl(4-(2-methoxyphenyl)piperazin-1-yl)methanones (NPPMs), and are effective inhibitors in vitro and in vivo. We further establish Sec14 is the sole essential NPPM target in yeast, that NPPMs exhibit exquisite targeting specificities for Sec14 (relative to related Sec14-like PITPs), propose a mechanism for how NPPMs exert their inhibitory effects, and demonstrate NPPMs exhibit exquisite pathway selectivity in inhibiting phosphoinositide signaling in cells. These data deliver proof-of-concept that PITP-directed SMIs offer new and generally applicable avenues for intervening with phosphoinositide signaling pathways with selectivities superior to those afforded by contemporary lipid kinase-directed strategies. PMID:24292071

Nile, Aaron H.; Tripathi, Ashutosh; Yuan, Peihua; Mousley, Carl J.; Suresh, Sundari; Wallace, Iain Michael; Shah, Sweety D.; Pohlhaus, Denise Teotico; Temple, Brenda; Nislow, Corey; Giaever, Guri; Tropsha, Alexander; Davis, Ronald W.; St Onge, Robert P.; Bankaitis, Vytas A.

2013-01-01

458

HPLC determination of D-3-hydroxybutyric acid by derivatization with a benzofurazan reagent and fluorescent detection: application in the analysis of human plasma.  

PubMed

A simple and sensitive new method for the determination of D-3-hydroxybutyric acid (D-3-HBA) in human plasma after derivatization is described. The proposed method is based on the reaction of (2S)-2-amino-3-methyl-1-[4-(7-nitro-benzo-2,1,3-oxadiazol-4-yl)-piperazin-1-yl]-butan-1-one (NBD-PZ-Val) with D-3-HBA in the presence of O-(7-azobenzotriazol-1-yl)-1,1,3,3-tetramethyluronium hexafluorophosphate (HATU) and N-ethyldiisopropylamine (DIEA) to produce a fluorescent derivative. The formed derivative was monitored fluorimetrically at ?(ex)=489 nm and ?(em)=532 nm. The HPLC analysis was carried out by use of a C18 analytical column (Synergy Hydro 150 mm × 3 mm, i.d., 4 ?m) with a binary gradient elution program of 0.1% aqueous trifluoroacetic acid versus methanol. The method showed satisfactory linearity (r(2)=0.9997) in the range from 20 to 500 ?mol/L. The limit of detection (LOD) of the method was 7.7 ?mol/L, while the limit of quantitation (LOQ) was 25.8 ?mol/L. The analytical method was successfully applied to human plasma samples from normal healthy subjects. PMID:24315779

Cevasco, Giorgio; Pi?tek, Anna Maria; Thea, Sergio

2014-02-15

459

Pharmacological evaluation of SN79, a sigma (?) receptor ligand, against methamphetamine-induced neurotoxicity in vivo.  

PubMed

Methamphetamine is a highly addictive psychostimulant drug of abuse, causing hyperthermia and neurotoxicity at high doses. Currently, there is no clinically proven pharmacotherapy to treat these effects of methamphetamine, necessitating identification of potential novel therapeutic targets. Earlier studies showed that methamphetamine binds to sigma (?) receptors in the brain at physiologically relevant concentrations, where it "acts in part as an agonist." SN79 (6-acetyl-3-(4-(4-(4-florophenyl)piperazin-1-yl)butyl)benzo[d]oxazol-2(3H)-one) was synthesized as a putative ? receptor antagonist with nanomolar affinity and selectivity for ? receptors over 57 other binding sites. SN79 pretreatment afforded protection against methamphetamine-induced hyperthermia and striatal dopaminergic and serotonergic neurotoxicity in male, Swiss Webster mice (measured as depletions in striatal dopamine and serotonin levels, and reductions in striatal dopamine and serotonin transporter expression levels). In contrast, di-o-tolylguanidine (DTG), a well established ? receptor agonist, increased the lethal effects of methamphetamine, although it did not further exacerbate methamphetamine-induced hyperthermia. Together, the data implicate ? receptors in the direct modulation of some effects of methamphetamine such as lethality, while having a modulatory role which can mitigate other methamphetamine-induced effects such as hyperthermia and neurotoxicity. PMID:22921523

Kaushal, Nidhi; Seminerio, Michael J; Robson, Matthew J; McCurdy, Christopher R; Matsumoto, Rae R

2013-08-01

460

Hippocampal 5-HT1A receptor binding is related to object-location memory in humans.  

PubMed

Animal studies suggest that serotonin, mediated by the 5-HT1A receptor, plays a key role in spatial learning and memory. The role of serotonin in spatial memory in humans has, however, been less well studied. This study examined the relationship between serotonin receptor density in the human brain and spatial learning and memory using the 5-HT1A receptor ligand (18)F-4-(2'-methoxyphenyl)-1-[2'-(N-2-pyridinyl)-p-fluorobenzamido]-ethyl-piperazine ([(18)F] MPPF) and positron emission tomography (PET). Ten neurologically healthy individuals underwent two [(18)F] MPPF PET scans, one while performing a task which involves processing of high-level spatial information ('house scan'), and one while performing a task which involves processing of low-level spatial information ('tunnel scan'). Navigation, recall of arbitrary associations between objects and their spatial location, and ability to draw a plan of the environment were tested following the house scan. 5-HT1A receptor binding did not differ significantly between processing high and low levels of spatial information. Hippocampal asymmetry in [(18)F] MPPF binding, however, was associated with memory for object-location associations; lower right than left hippocampal binding potential (BPND) was related to better memory performance. We conclude that hippocampal serotonergic function plays a role in a fundamental component of human spatial memory, the ability to recall the location of encountered objects. PMID:24807817

Glikmann-Johnston, Yifat; Saling, Michael M; Chen, Jian; O'Keefe, Graeme; Gong, Sylvia; Tochon-Danguy, Henri; Mulligan, Rachel; Reutens, David C

2014-05-01

461

Phytochemical, Anti-oxidant and Anthelmintic activities of various leaf extracts of Flacourtia sepiaria Roxb  

PubMed Central

Objective The present study was carried out to investigate the phytochemical constituents, in vitro antioxidant potential and anthelmintic activities of Flacourtia sepiaria Roxb leaves. Methods The dried powdered leaves of Flacourtia sepiaria were extracted using petroleum ether, chloroform, ethyl acetate and methanol by a soxhlet extractor and preliminary phytochemical screening was performed using standard protocols. All the extract was evaluated for their potential antioxidant activities using test such as DPPH, superoxide anion radical, hydroxyl radical, nitric oxide radical scavenging abilities, ferrous chelating ability and total phenolic and flavanoid content. Anthelmintic activity of extract was screened in adult Indian earthworm model. Results Preliminary screening revealed the presence of bioactive compounds especially phenolics, tannins and terpenoids in all extracts. The phenolic and flavanoid content was highest in methanolic extract and lowest in petroleum ether extract. The paralytic (9.46±0.212) and death time (31.43±0.148) of methanolic extract was found to be significant (P<0.05) when compared with paralytic (7.33±0.206) and death time (18.60±0.229) of standard piperazine citrate at 100 mg/mL concentration. Conclusions The results of the present study indicate that the leaf extracts of Flacourtia sepiaria exhibited strong antioxidant activity and possess significant anthelmintic activity and thus it is a good source of antioxidant and anthelmintic constituents. PMID:24093785

Sreejith, M; Kannappan, N; Santhiagu, A; Mathew, Ajith P

2013-01-01

462

(+)-SKF-10,047 and dextromethorphan ameliorate conditioned fear stress through the activation of phenytoin-regulated sigma 1 sites.  

PubMed

Mice exhibited a marked suppression of motility when they were replaced in the same environment in which they had previously received an electric footshock. This psychological stress-induced motor suppression, known as conditioned fear stress, was dose dependently attenuated by (+)-N-allylnormetazocine ((+)-SKF-10,047) and by dextromethorphan, putative sigma receptor agonists, but not by other sigma receptor ligands, (+)-pentazocine and 1,3-di-(2-tolyl)guanidine (DTG). Unlike (+)-SKF-10,047 and dextromethorphan, the non-competitive NMDA receptor antagonists, phencyclidine and dizocilpine, attenuated the conditioned fear stress only at high doses that induced marked hypermotility in non-stressed mice. The effects of (+)-SKF-10,047 and dextromethorphan, but not phencyclidine and dizocilpine, on the conditioned fear stress were antagonized by the sigma receptor antagonists, NE-100 (N,N-dipropyl-2-[4-methoxy-3-(2- phenylethoxy)phenyl]-ethylamine monohydrochloride) and BMY-14802 (alpha-(4-fluorophenyl)-4-(5-fluoro-2-pyrimidinyl)-1-piperazine- butanol hydrochloride). Interestingly, the effects of (+)-SKF-10,047 and dextromethorphan on the stress response were enhanced by combination with phenytoin, an anticonvulsant drug, whereas those of (+)- pentazocine, DTG, phencyclidine, and dizocilpine were not. These results suggest that activation of phenytoin-regulated type sigma 1 receptors, but not of phencyclidine receptors, is involved in the ameliorating effects of (+)-SKF-10,047 and dextromethorphan on stress-induced motor suppression. PMID:8901003

Kamei, H; Kameyama, T; Nabeshima, T

1996-03-28

463

Development of a new Ca{sup 2+}/calmodulin antagonist and its anti-proliferative activity against colorectal cancer cells  

SciTech Connect

We previously identified a cellular target of a cell cycle inhibitor HBC as Ca{sup 2+}/calmodulin (Ca{sup 2+}/CaM) through chemical genetics approach. Using the mechanism-based drug design, we developed a new Ca{sup 2+}/CaM antagonists based on the structure of HBC. The compound, (4-{l_brace}3,5-bis-[2-(4-hydroxy-3-methoxy-phenyl)-vinyl]-4,5-dihydro-pyrazol-1-yl {r_brace}-phenyl)-(4-methyl-piperazin-1-yl)-methanone (referred as HBCP), binds to Ca{sup 2+}/CaM in vitro and inhibits the proliferation of HCT15 colon cancer cells. HBCP induced sustained phosphorylation of ERK1/2 and subsequently activated p21{sup WAF1} expression in HCT15 cells. Moreover, HBCP reversibly induced the G{sub 0}/G{sub 1} cell cycle arrest in the cells. These data demonstrate that HBCP is a new potent Ca{sup 2+}/CaM antagonist and can be applied for CaM related therapeutic uses.