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1

1D and 2D absorption-rate\\/kinetic modeling and simulation of carbon dioxide absorption into mixed aqueous solutions of MDEA and PZ in a laminar jet apparatus  

Microsoft Academic Search

The kinetics of the reaction between carbon dioxide (CO2) and mixed solutions of methyldiethanolamine (MDEA) and piperazine (PZ) was investigated experimentally in a laminar jet apparatus. The experimental kinetic data were obtained under no interfacial turbulence and over a temperature range from 313 to 333K, MDEA\\/PZ wt% concentration ratios of 27\\/3, 24\\/6 and 21\\/9, and CO2 loadings from 0.0095 to

Mohamed Edali; Raphael Idem; Ahmed Aboudheir

2010-01-01

2

Kinetics, modeling, and simulation of the experimental kinetics data of carbon dioxide absorption into mixed aqueous solutions of MDEA and PZ using laminar jet apparatus with a numerically solved absorption-rate\\/kinetic model  

Microsoft Academic Search

The kinetics of the reaction between carbon dioxide (CO2) and mixed solutions of Methyldiethanolamine (MDEA) and Piperazine (PZ) was investigated experimentally in a laminar jet apparatus. The experimental kinetic data were obtained under no interfacial turbulence and over a temperature range from 313 to 333 K, MDEA\\/PZ wt% concentration ratio of 27\\/3, 24\\/6 and 21\\/9, and CO2 loading from 0.0095 to 0.33

Raphael Idem; Mohamed Edali; Ahmed Aboudheir

2009-01-01

3

Absorption of carbonyl sulfide in aqueous methyldiethanolamine  

SciTech Connect

The absorption of carbonyl sulfide in aqueous methyldiethanolamine (MDEA) was studied over a range of temperatures and MDEA concentrations. MDEA is commonly used for selective absorption of hydrogen sulfide in the presence of carbon dioxide. However, sulfur in the form of COS may also be present and it is necessary that estimates of absorption rates of this compound be made. The objective of this study is to determine the physiochemical properties needed to predict COS absorption rates in aqueous MDEA. Free gas solubility and the diffusivity of COS in MDEA solutions were measured over the temperature range 15 to 40{sup 0}C for MDEA concentrations up to 30 weight per cent using the nitrous oxide analogy method. Solubilities were measured volumetrically in an equilibrium cell and diffusivities were measured using a laminar liquid jet absorber. The kinetics of the reaction between COS and MDEA were studied by measuring absorption rates in a single wetted-sphere absorber.

Al-Ghawas, H.A.; Ruiz-Ibanez, G.; Sandall, O.C. (Dept. of Chemical and Nuclear Engineering, Univ. of California, Santa Barbara, CA (US))

1988-01-01

4

Experimental investigation of the phase equilibria in the carbon dioxide-propane-3 M MDEA system  

Microsoft Academic Search

The treating of liquefied petroleum gas (LPG) to remove carbon dioxide and hydrogen sulfide using aqueous alkanolamine solutions is an important aspect of gas processing. One of the amines used in the natural gas industry is methyldiethanolamine (MDEA). Measurements of the phase equilibria in the carbon dioxide-propane-3 M MDEA system have been made at 25 and 40 C at pressures

Fang-Yuan Jou; Alan E. Mather; Frederick D. Otto; John J. Carroll

1995-01-01

5

Kinetics and modelling of carbon dioxide absorption into aqueous solutions of N-methyldiethanolamine  

Microsoft Academic Search

A wetted-sphere absorber was used to acquire kinetic data for the aqueous phase reaction between CO2 and N-methyldiethanolamine (MDEA). Data were obtained over the temperature range of 293–342 K for partial pressures of CO2 near atmospheric and for 10–30 mass% MDEA. The data are consistent with a mechanism in which MDEA catalyzes the hydrolysis of CO2. Three different mathematical models

Edward B. Rinker; S. Ashour Sami; Orville C. Sandall

1995-01-01

6

Partial vapor pressure of CO 2 and H 2S over aqueous methyldiethanolamine solutions  

Microsoft Academic Search

A new apparatus is presented to measure low partial vapor pressures of acid gas. New measurements are given for carbon dioxide and hydrogen sulfide into aqueous solutions of methyldiethanolamine (MDEA). Large discrepancies among the measured VLE data and the slopes of their solubility curves are found between the authors due to systematic experimental errors, and particularly in the low acid

B. Lemoine; Yi-Gui Li; R. Cadours; C. Bouallou; D. Richon

2000-01-01

7

Experimental investigation of the phase equilibria in the carbon dioxide-propane-3 M MDEA system  

SciTech Connect

The treating of liquefied petroleum gas (LPG) to remove carbon dioxide and hydrogen sulfide using aqueous alkanolamine solutions is an important aspect of gas processing. One of the amines used in the natural gas industry is methyldiethanolamine (MDEA). Measurements of the phase equilibria in the carbon dioxide-propane-3 M MDEA system have been made at 25 and 40 C at pressures up to 15.5 MPa. Vapor-liquid, liquid-liquid, and vapor-liquid-liquid equilibria were determined. The vapor-liquid equilibrium data were compared with the model of Deshmukh and Mather.

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

1995-07-01

8

Kinetics of carbon dioxide absorption into mixed aqueous solutions of MDEA and MEA using a laminar jet apparatus and a numerically solved 2D absorption rate\\/kinetics model  

Microsoft Academic Search

New comprehensive numerically solved 1D and 2D absorption rate\\/kinetics models have been developed, for the first time, to interpret the experimental kinetic data obtained with a laminar jet apparatus for the absorption of carbon dioxide (CO2) in CO2 loaded mixed solutions of mixed amine system of methyldiethanolamine (MDEA) and monoethanolamine (MEA). Three MDEA\\/MEA weight ratios ranging from 27\\/03 to 23\\/07,

Mohamed Edali; Ahmed Aboudheir; Raphael Idem

2009-01-01

9

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

10

Carbon dioxide absorption in piperazine activated N-methyldiethanolamine  

Microsoft Academic Search

The removal of carbon dioxide from process gas streams is an important step in many industrial processes for a number of technical, economical or environmental reasons. The conventional technology to capture CO2 on large scale is the absorption - desorption process, in which (aqueous) solutions of alkanolamines are frequently used as solvents [Kohl and Nielsen, 1997]. Nowadays, the addition of

Peter Wilhelmus Jacques Derks

2006-01-01

11

Kinetics of the Absorption of CO{sub 2} in Aqueous Solutions of N-Methyldiethanolamine plus Triethylene Tetramine  

SciTech Connect

This work focuses on the development of a new solvent for CO{sub 2} capture. This new solvent is an aqueous solution with a blend of N-methyldiethanolamine (MDEA) and triethylene tetramine (TETA), an amine with four amino groups. CO{sub 2} absorption was investigated between 298 and 333 K using a Lewis cell with a constant interfacial area. Several concentrations of MDEA (17.5 and 40 wt %) and TETA (3 and 6 wt %) were assessed. The influence of the CO{sub 2} partial pressure on the absorption rate was pointed out. The addition of small amount of TETA leads to a high increase in the CO{sub 2} absorption rates. A numerical model based on the film theory was used to determine the rate coefficients between CO{sub 2} and TETA for the different solvents. The physicochemical parameters have a huge influence on the determination of the rate coefficients.

Amann, J.M.G.; Bouallou, C. [Centre Energetique et Procedes CEP, Paris (France)

2009-04-15

12

MDEA related death in Crete: a case report and literature review.  

PubMed

"Designer drugs" are derivatives of approved drugs abused for recreational effect and created by underground laboratories to circumvent legal restriction. By far the most controversial drug has been MDMA (3,4-methylenedioxymethamphetamine) and the newer derivative MDEA (3,4-methylenedioxymethamphetamine) often called "Eve". MDEA-related deaths have not been reported in the US, but there have been a death of MDMA and MDEA severe poisonings. Convulsions, collapse, hyperpyrexia, disseminated intravascular coagulation rhabdomyolysis, and acute liver and renal damage result from the ingestion of the drug. Complications may occur and severity and death possibly result. The case of a 31-y-old male, the first victim of MDEA in Greece, is reported. Blood MDEA was 3.1 micrograms/mL; MDEA concentrations in liver, lung and kidney were 4.8, 5.2, and 4.8 micrograms/g respectively. PMID:9251177

Tsatsakis, A M; Michalodimitrakis, M N; Patsalis, A N

1997-08-01

13

Novel Chromosomally Encoded Multidrug Efflux Transporter MdeA in Staphylococcus aureus  

Microsoft Academic Search

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

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

2004-01-01

14

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

15

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

16

Acid gases partial pressures above a 50 wt% aqueous methyldiethanolamine solution: Experimental work and modeling  

Microsoft Academic Search

Aqueous amine solutions are widely used in the industry for acid gas removal. In order to treat natural gas or refinery process streams, an accurate knowledge of solubility data of carbon dioxide, hydrogen sulfide and other sulfur species in aqueous amine solutions is required. In this paper, new equilibrium measurements on 50wt% aqueous methyldiethanolamine solution with CO2 and H2S have

Moussa Dicko; Christophe Coquelet; Carmen Jarne; Scott Northrop; Dominique Richon

2010-01-01

17

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

18

Piperazine compounds as drugs of abuse.  

PubMed

Synthetic drugs are among the most commonly abused drugs in the world. This abuse is widespread among young people, especially in the dance club and rave scenes. Over the last several years, piperazine derived drugs have appeared, mainly available via the internet, and sold as ecstasy pills or under the names of "Frenzy", "Bliss", "Charge", "Herbal ecstasy", "A2", "Legal X" and "Legal E". Although in the market piperazine designer drugs have the reputation of being safe, several experimental and epidemiological studies indicate risks for humans. Piperazine designer drugs can be divided into two classes, the benzylpiperazines such as N-benzylpiperazine (BZP) and its methylenedioxy analogue 1-(3,4-methylenedioxybenzyl)piperazine (MDBP), and the phenylpiperazines such as 1-(3-chlorophenyl)piperazine (mCPP), 1-(3-trifluoromethylphenyl)piperazine (TFMPP), and 1-(4-methoxyphenyl)piperazine (MeOPP). Toxicokinetic properties, including metabolic pathways, actions and effects in animals and humans, with some hypothesis of mechanism of action, and analytical approaches for the identification of these drugs are summarized in this review. PMID:22071119

Arbo, M D; Bastos, M L; Carmo, H F

2011-11-08

19

21 CFR 520.1805 - Piperazine phosphate with thenium closylate tablets.  

Code of Federal Regulations, 2013 CFR

... 2013-04-01 false Piperazine phosphate with thenium closylate tablets. 520...ANIMAL DRUGS § 520.1805 Piperazine phosphate with thenium closylate tablets. ...piperazine hexahydrate (as piperazine phosphate) and 125 milligrams thenium (as...

2013-04-01

20

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

1998-11-01

21

Inhibition of Noroviruses by Piperazine Derivatives  

PubMed Central

There is currently an unmet need for the development of small-molecule therapeutics for norovirus infection. The piperazine scaffold, a privileged structure embodied in many pharmacological agents, was used to synthesize an array of structurally-diverse derivatives which were screened for anti-norovius activity in a cell-based replicon system. The studies described herein demonstrate for the first time that functionalized piperazine derivatives possess anti-norovirus activity. Furthermore, these studies have led to the identification of two promising compounds (6a, 9l) that can be used as a launching pad for the optimization of potency, cytotoxicity, and drug-like characteristics.

Dou, Dengfeng; He, Guijia; Mandadapu, Sivakoteswara Rao; Aravapalli, Sridhar; Kim, Yunjeong; Chang, Kyeong-Ok; Groutas, William C.

2011-01-01

22

Gene cloning and characterization of MdeA, a novel multidrug efflux pump in Streptococcus mutans.  

PubMed

Multidrug resistance, especially multidrug efflux mechanisms that extrude structurally unrelated cytotoxic compounds from the cell by multidrug transporters, is a serious problem and one of the main reasons for the failure of therapeutic treatment of infections by pathogenic microorganisms as well as of cancer cells. Streptococcus mutans is considered one of the primary causative agents of dental caries and periodontal disease, which comprise the most common oral diseases. A fragment of chromosomal DNA from S. mutans KCTC3065 was cloned using Escherichia coli KAM32 as host cells lacking major multidrug efflux pumps. Although E. coli KAM32 cells were very sensitive to many antimicrobial agents, the transformed cells harboring a recombinant plasmid became resistant to several structurally unrelated antimicrobial agents such as tetracycline, kanamycin, rhodamin 6G, ampicillin, acriflavine, ethidium bromide, and tetraphenylphosphonium chloride. This suggested that the cloned DNA fragment carries a gene encoding a multidrug efflux pump. Among 49 of the multidrug-resistant transformants, we report the functional gene cloning and characterization of the function of one multidrug efflux pump, namely MdeA from S. mutans, which was expressed in E. coli KAM32. Judging from the structural and biochemical properties, we concluded that MdeA is the first cloned and characterized multidrug efflux pump using the proton motive force as the energy for efflux drugs. PMID:23462018

Kim, Do Kyun; Kim, Kyoung Hoon; Cho, Eun Ji; Joo, Seoung-Je; Chung, Jung-Min; Son, Byoung Yil; Yum, Jong Hwa; Kim, Young-Man; Kwon, Hyun-Ju; Kim, Byung-Woo; Kim, Tae Hoon; Lee, Eun-Woo

2013-03-01

23

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

Code of Federal Regulations, 2010 CFR

...piperazine-carbon disulfide complex contains equimolar parts of piperazine and carbon disulfide (1 gram contains 530 mgs of piperazine and 470 mgs of carbon disulfide). (b) Sponsor. See 000009 in § 510.600(c) of this chapter. (c)...

2009-04-01

24

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

Code of Federal Regulations, 2013 CFR

... 2013-04-01 false Piperazine-carbon disulfide complex suspension. 520...ANIMAL DRUGS § 520.1802a Piperazine-carbon disulfide complex suspension. (a...suspension contains 7.5 grams of piperazine-carbon disulfide complex. The...

2013-04-01

25

Solubility of nitrous oxide in aqueous blends of N-methyldiethanolamine and 2-amino-2-methyl-1-propanol  

SciTech Connect

Aqueous solutions of alkanolamines have applications in acid gas treatment for the removal of acid gases such as carbon dioxide and hydrogen sulfide. The solubility of nitrous oxide in aqueous blends of N-methyldiethanolamine and 2-amino-2-methyl-1 propanol was measured over the temperature range 10--60 C. The total composition of the alkanolamines in water ranged from 30 to 50 mass %. The experimental results were interpreted in terms of Henry`s constants.

Davis, R.A.; Pogainis, B.J. [Univ. of Minnesota, Duluth, MN (United States). Dept. of Chemical Engineering

1995-11-01

26

Carbon dioxide capture with concentrated, aqueous piperazine  

Microsoft Academic Search

Concentrated, aqueous piperazine (PZ) has been investigated as a novel amine solvent for carbon dioxide (CO2) absorption. The CO2 absorption rate of aqueous PZ is more than double that of 7m MEA and the amine volatility at 40°C ranges from 11 to 21ppm. Thermal degradation is negligible in concentrated, aqueous PZ up to a temperature of 150°C, a significant advantage

Stephanie A. Freeman; Ross Dugas; David H. Van Wagener; Thu Nguyen; Gary T. Rochelle

2010-01-01

27

Contribution of artifacts to N-methylated piperazine cyanide adduct formation in vitro from N-alkyl piperazine analogs.  

PubMed

In the liver microsome cyanide (CN)-trapping assays, piperazine-containing compounds formed significant N-methyl piperazine CN adducts. Two pathways for the N-methyl piperazine CN adduct formation were proposed: 1) The ?-carbon in the N-methyl piperazine is oxidized to form a reactive iminium ion that can react with cyanide ion; 2) N-dealkylation occurs followed by condensation with formaldehyde and dehydration to produce N-methylenepiperazine iminium ion, which then reacts with cyanide ion to form the N-methyl CN adduct. The CN adduct from the second pathway was believed to be an artifact or metabonate. In the present study, a group of 4'-N-alkyl piperazines and 4'-N-[¹³C]methyl-labeled piperazines were used to determine which pathway was predominant. Following microsomal incubations in the presence of cyanide ions, a significant percentage of 4'-N-[¹³C]methyl group in the CN adduct was replaced by an unlabeled natural methyl group, suggesting that the second pathway was predominant. For 4'-N-alkyl piperazine, the level of 4'-N-methyl piperazine CN adduct formation was limited by the extent of prior 4'-N-dealkylation. In a separate study, when 4'-NH-piperaziens were incubated with potassium cyanide and [¹³C]-labeled formaldehyde, 4'-N-[¹³C]methyl piperazine CN-adduct was formed without NADPH or liver microsome suggesting a direct Mannich reaction is involved. However, when [¹³C]-labeled methanol or potassium carbonate was used as the one-carbon donor, 4'-N-[¹³C]methyl piperazine CN adduct was not detected without liver microsome or NADPH present. The biologic and toxicological implications of bioactivation via the second pathway necessitate further investigation because these one-carbon donors for the formation of reactive iminium ions could be endogenous and readily available in vivo. PMID:23431111

Zhang, Minli; Resuello, Christina M; Guo, Jian; Powell, Mark E; Elmore, Charles S; Hu, Jun; Vishwanathan, Karthick

2013-02-19

28

Carbon dioxide absorption with aqueous potassium carbonate promoted by piperazine  

Microsoft Academic Search

Many commercial processes for the removal of carbon dioxide from high-pressure gases use aqueous potassium carbonate systems promoted by secondary amines. This paper presents thermodynamic and kinetic data for aqueous potassium carbonate promoted by piperazine. Research has been performed at typical absorber conditions for the removal of CO2 from flue gas.Piperazine, used as an additive in 20–30wt% potassium carbonate, was

J. Tim Cullinane; Gary T. Rochelle

2004-01-01

29

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

Code of Federal Regulations, 2013 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...

2013-04-01

30

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

Code of Federal Regulations, 2013 CFR

... 2013-04-01 false Piperazine-carbon disulfide complex with phenothiazine suspension...ANIMAL DRUGS § 520.1802c Piperazine-carbon disulfide complex with phenothiazine suspension...ounce contains 5 grams of piperazine-carbon disulfide complex and 0.83 gram of...

2013-04-01

31

The acute effect in rats of 3,4-methylenedioxyethamphetamine (MDEA, "eve") on body temperature and long term degeneration of 5-HT neurones in brain: a comparison with MDMA ("ecstasy").  

PubMed

Administration of a single dose of the recreationally used drug 3,4-methylenedioxyethamphetamine (MDEA or "eve") to Dark Agouti rats resulted in an acute dose-dependent hyperthermic response. The peak effect and duration of hyperthermia of a dose of MDEA of 35 mg/kg intraperitoneally was similar to a dose of 3,4-methylenedioxymethamphetamine (MDMA or "ecstasy") of 15 mg/kg intraperitoneally. Seven days later this dose of MDMA produced a marked (approximately 50%) loss of 5-HT and its metabolite 5-HIAA in cortex, hippocampus and striatum and a similar loss of [3H]-paroxetine binding in cortex: these losses reflecting the MDMA-induced neurotoxic degeneration of 5-HT nerve endings. In contrast, administration of MDEA (15, 25 or 35 mg/kg), even at the highest dose, produced only a 20% loss in cortex and hippocampus and no decrease in striatum. The neurotoxic effect of MDEA was only weakly dose-dependent. Neither MDEA (35 mg/kg) nor MDMA (15 mg/kg) altered striatal dopamine content 7 days later. MDEA appeared to have about half the potency of MDMA in inducing acute hyperthermia and 25% of the potency in inducing degeneration of cerebral 5-HT neurones. However since higher doses of MDEA (compared to MDMA) are probably necessary to induce mood changing effects, these data do not support any contention that this compound is a "safer" recreational drug than MDMA in terms of either acute toxicity or long term neurodegeneration. PMID:10401727

Colado, M I; Granados, R; O'Shea, E; Esteban, B; Green, A R

1999-06-01

32

1-Substituted 4-(3-Hydroxyphenyl)piperazines Are Pure Opioid Receptor Antagonists  

PubMed Central

This report describes the discovery that 1-substituted 4-(3-hydroxyphenyl)piperazines are pure opioid receptor antagonists. Compounds in this new series include N-phenylpropyl (3S)-3-methyl-4-(3-hydroxyphenyl)piperazine and (3R)-3-methyl-4-(3-hydroxyphenyl)piperazine, both of which diaplay low nanomolar potencies at ?, ?, and ? receptors and pure antagonist properties in a [35S]GTP?S assay.

Carroll, F. Ivy; Cueva, Juan Pablo; Thomas, James B.; Mascarella, S. Wayne; Runyon, Scott P.; Navarro, Hernan A.

2010-01-01

33

Sorption and Permeation of Aqueous Alkyl Piperazines through Hydrophilic and Organophilic Membranes: A Transport Analysis  

Microsoft Academic Search

A detailed analysis of separation of N-methyl piperazine (NMP), N-ethyl pipera-zine (NEP), and water was undertaken by the pervaporation technique. A systematic study of sorption and permeation of the aqueous alkyl piperazines through poly(dimethylsiloxane) (PDMS), styrene-butadiene rubber (SBR), PDMS filled with zeolites NaX and silicalite (SA-5), polyimide (PI), and poly(acrylonitrile-co-acrylic acid) (PAN-co-AA) was carried out at different concentrations and temperatures.

M. V. Dagaonkar; S. B. Sawant; J. B. Joshi; V. G. Pangarkar

1998-01-01

34

Solid-liquid equilibrium for mixtures containing cresols, piperazine, and dibutyl ether  

Microsoft Academic Search

The solid-liquid phase diagrams have been determined for six binary and one ternary system composed of m-cresol, p-cresol, piperazine, and dibutyl ether. The results indicate the existence of 1-2 complexes in the p-cresol + m-cresol, piperazine + m-cresol, and piperazine + p-cresol systems. The observed melting points were correlated with composition by an empirical equation. Dissociation extractive crystallization is one

Mingjer Lee; Peichi Chi

1993-01-01

35

4-Nitro-phenol-piperazine (2/1)  

PubMed Central

In the title adduct, C6H5NO3·0.5C4H10N2, the piperazine ring possesses inversion symmetry and has a chair conformation. Its mean plane makes a dihedral angle of 65.45?(7)° with the 4-nitro­phenol ring. In the crystal, the piperazine ring is linked to two 4-nitro­phenol mol­ecules via O—H?N hydrogen bonds. The mol­ecules are also linked via bifurcated N—H?(O,O) hydrogen bonds involving the NO2 O atoms, forming a two-dimensional network lying parallel to (102). The networks are linked via C—H?O hydrogen bonds, forming a three-dimensional structure.

Nagapandiselvi, Perumal; Muralidharan, Srinivasan; Srinivasan, Thothadri; Goplalakrishnan, Rengaswamy; Velmurugan, Devadasan

2013-01-01

36

Development and Validation of a Disk Solid Phase Extraction and Gas Chromatography-Mass Spectrometry Method for MDMA, MDA, HMMA, HMA, MDEA, Methamphetamine and Amphetamine in Sweat  

PubMed Central

We describe the development and validation of a method for the simultaneous quantification of 3,4-methylenedioxymethamphetamine (MDMA), 3,4-methylenedioxyamphetamine (MDA), 3-hydroxy-4-methoxymethamphetamine (HMMA), 3-hydroxy-4-methoxyamphetamine (HMA), 3,4-methylenedioxyethylamphetamine (MDEA), methamphetamine (MAMP) and amphetamine (AMP) in sweat. Drugs were eluted from PharmChek™ sweat patches with sodium acetate buffer, extracted with disk solid phase extraction and analyzed using GC/MS-EI with selected ion monitoring. Limits of quantification (LOQ) for MDMA, MDEA, MAMP and AMP were 2.5 ng/patch, and 5 ng/patch for MDA, HMA and HMMA. This fully validated procedure was more sensitive than previously published analytical methods and permitted the simultaneous analysis of multiple amphetamine analogs in human sweat.

De Martinis, Bruno S.; Barnes, Allan J.; Scheidweiler, Karl B.; Huestis, Marilyn A.

2009-01-01

37

Degradation of aqueous piperazine in carbon dioxide capture  

Microsoft Academic Search

Concentrated, aqueous piperazine (PZ) is a novel solvent for carbon dioxide (CO2) capture by absorption\\/stripping. One of the major advantages of PZ is its resistance to thermal degradation and oxidation.At 135 and 150°C, 8m PZ is up to two orders of magnitude more resistant to thermal degradation than 7m monoethanolamine (MEA). After 18 weeks at 150°C, only 6.3% of the

Stephanie A. Freeman; Jason Davis; Gary T. Rochelle

2010-01-01

38

An evolving role of piperazine moieties in drug design and discovery.  

PubMed

This article purposes to provide insights to piperazine based molecular designs that will facilitate drug discovery program in future. In our pursuit to summarize the reservoir of bioactive agents, and in line with the synthetic economy of new heterocycles, many new roles are being identified for the multiple biotargets of piperazine moieties. We mark out how series of different scaffolds provide an extensive range of various piperazine-based analogues displaying antimicrobial, antituberculosis, anticancer, antiviral and antimalarial activities. We believe that piperazine family of compounds, and their various co-components, highlight the existence of several potential leads for the furtherance of novel bioactive agents. PMID:23895191

Patel, Rahul V; Park, Se Won

2013-10-01

39

Development of a validated method for the simultaneous determination of amphetamine, methamphetamine and methylenedioxyamphetamines (MDA, MDMA, MDEA) in serum by GC-MS after derivatisation with perfluorooctanoyl chloride  

Microsoft Academic Search

A rapid and simple method for the simultaneous detection and quantitation of amphetamine, methamphetamine, methylenedioxyamphetamine\\u000a (MDA), methylenedioxymethamphetamine (MDMA) and methylenedioxyethylamphetamine (MDEA) in human serum was developed and fully\\u000a validated. Serum samples were extracted with cyclohexane, derivatised with perfluorooctanoyl chloride without prior evaporation\\u000a of the solvent and analysed with gas chromatography-mass spectrometry (GC-MS) in the selected ion monitoring mode (SIM). For

Folker Westphal; Cornelia Franzelius; Jon Schäfer; Hans Werner Schütz; Gertrud Rochholz

2007-01-01

40

GC–MS and GC–IRD analysis of ring and side chain regioisomers of ethoxyphenethylamines related to the controlled substances MDEA, MDMMA and MBDB  

Microsoft Academic Search

Three regioisomeric 3, 4-methylenedioxyphenethylamines having the same molecular weight and major mass spectral fragments of equal mass have been reported as drugs of abuse in recent years. These compounds are 3,4-methylenedioxy-N-ethylamphetamine (MDEA), 3,4-methylenedioxy-N,N-dimethylamphetamine (MDMMA), and N-methyl-1-(3,4-methylenedioxyphenyl)-2-butanamine (MBDB). Ring substituted ethoxy phenethylamines having the same side chain are compounds with an isobaric relationship to these controlled drug substances, all have molecular

Abdullah M. Al-Hossaini; Tamer Awad; Jack DeRuiter; C. Randall Clark

2010-01-01

41

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  

Microsoft Academic Search

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

Nexant

2011-01-01

42

Two-Dimensional Gas Chromatography\\/ Electron-Impact Mass Spectrometry with Cryofocusing for Simultaneous Quantification of MDMA, MDA, HMMA, HMA, and MDEA in Human Plasma  

Microsoft Academic Search

BACKGROUND: 3,4-Methylenedioxymethamphetamine (MDMA, or Ecstasy) is a popular recreational drug. Analysis of MDMA and metabolites in human plasma, particularly in pharmacokinetic studies, requires low limits of quantification. Two-dimensional GC\\/MS with cryofocusing is a chromatographic technique rec- ognized for its increased selectivity and resolution. METHODS: This method simultaneously quantifies 3,4- methylenedioxyethylamphetamine (MDEA), MDMA, and its metabolites, 3,4-methylenedioxyamphetamine (MDA), 4-hydroxy-3-methoxymethamphetamine (HMMA), and

Erin A. Kolbrich; Ross H. Lowe; Marilyn A. Huestis

43

GC-MS studies on the regioisomeric methoxy-methyl-phenethylamines related to MDEA, MDMMA, and MBDB.  

PubMed

Three regioisomeric 3,4-methylenedioxyphenethylamines having the same molecular weight and major mass spectral fragments of equal mass have been reported as drugs of abuse in forensic studies in recent years. These compounds are 3,4-methylenedioxy-N-ethylamphetamine (MDEA), 3,4-methylenedioxy-N-N-dimethylamphetamine (MDMMA), and N-methyl-1-(3,4-methylenedioxyphenyl)-2-butanamine (MBDB). The mass spectra of the regioisomers (4-methoxy-3-methyl and 4-methoxy-2-methyl-phenethylamines) are essentially equivalent to the three compounds reported as drugs of abuse. This project focused on the synthesis, mass spectral characterization, and chromatographic analysis of these six regioisomeric methoxy methyl phenethylamines. Additionally, the mass spectral and chromatographic properties of these compounds will be compared to the isobaric 2,3- and 3,4-methylenedioxyphenethyl-amines of the same side chain. The six regioisomeric methoxy-methyl-phenethylamines were synthesized from commercially available starting materials. Side chain differentiation by mass spectrometry was possible after the formation of the perfluoroacyl derivatives, pentafluoropropionylamides (PFPA) and heptafluorobutrylamides (HFBA). Gas chromatographic separation on Rtx-1 was successful at resolving the perfluoroacyl derivatives of the 4-methoxy-3-methyl phenethylamines from those of the 4-methoxy-2-methyl phenethylamines. The 4-methoxy-3-methyl-phenethylamine derivatives eluted before the 4-methoxy-2-methyl-phenethylamine derivatives as both the PFPA and HFBA derivatives. PMID:19007498

Thigpen, Ashley; Awad, Tamer; Deruiter, Jack; Clark, C Randall

44

Effect of piperazine (diethylenediamine) on the moulting, proteome expression and pyrophosphatase activity of Ascaris suum lung-stage larvae  

Microsoft Academic Search

Piperazine (diethylenediamine) is an anthelmintic widely used against animal and bird ascariasis. In this study, we show that treatment with piperazine blocks Ascaris suum larval moulting and development processes and affects larval proteome expression profiles. A. suum lung-stage L3 (LL3) obtained from an infected rabbit's lungs were cultured in RPMI medium in the presence of increasing concentrations of piperazine sulfate

M. Khyrul Islam; Takeharu Miyoshi; Manabu Yamada; M. Abdul Alim; Xiaohong Huang; Maki Motobu; Naotoshi Tsuji

2006-01-01

45

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...

46

1,4-Bis(2-diazo-acet-yl)piperazine  

PubMed Central

The asymmetric unit of the title compound, C8H10N6O2, contains one-half mol­ecule, which is completed by a crystallographic center of symmetry. The piperazine ring adopts a chair conformation. In the crystal, weak C—H?O inter­actions link the mol­ecules into layers parallel to the bc plane. The crystal packing also exhibits short N?N contacts of 3.0467?(16)?Å between the terminal diazo N atoms from neighbouring mol­ecules.

Kaupang, Asmund; Gorbitz, Carl Henrik; Bonge-Hansen, Tore

2013-01-01

47

Reactions of CO2 with aqueous piperazine solutions: formation and decomposition of mono- and dicarbamic acids/carbamates of piperazine at 25.0 °C.  

PubMed

Piperazine (PZ) is widely recognized as a promising solvent for postcombustion capture (PCC) of carbon dioxide (CO(2)). In view of the highly conflicting data describing the kinetic reactions of CO(2)(aq) in piperazine solutions, the present study focuses on the identification of the chemical mechanism, specifically the kinetic pathways for CO(2)(aq) in piperazine solutions that form the mono- and dicarbamates, using the analysis of stopped-flow spectrophotometric kinetic measurements and (1)H NMR spectroscopic data at 25.0 °C. The complete set of rate and equilibrium constants for the kinetic pathways, including estimations for the protonation constants of the suite of piperazine carbamates/carbamic acids, is reported here using an extended kinetic model which incorporates all possible reactions for CO(2)(aq) in piperazine solutions. From the kinetic data determined in the present study, the reaction of CO(2)(aq) with free PZ was found to be the dominant reactive pathway. The superior reactivity of piperazine is confirmed in the kinetic rate constant determined for the formation of piperazine monocarbamic acid (k(7) = 2.43(3) × 10(4) M(-1) s(-1)), which is within the wide range of published values, making it one of the faster reacting amines. The corresponding equilibrium constant for the formation of the monocarbamic acid, K(7), markedly exceeds that of other monoamines. Kinetic and equilibrium constants for the remaining pathways indicate a minor contribution to the overall kinetics at high pH; however, these pathways may become more significant at higher CO(2) loadings and lower pH values where the concentrations of the reactive species are correspondingly higher. PMID:23286883

Conway, William; Fernandes, Debra; Beyad, Yaser; Burns, Robert; Lawrance, Geoffrey; Puxty, Graeme; Maeder, Marcel

2013-01-25

48

Synthesis and Properties of Piperazine Derivatives and Their Quaternary Ammonium Amphiphilic Salts  

Microsoft Academic Search

A series of long-chain piperazine derivatives,N-alkyl-N?-methyl piperazine and their amphiphilic salts,N-alkyl-N?-ethyl-N?-methyl piperazinium bromide, and the relatedN-alkyl-N,N?-dimethyl piperazinium bromide were synthesized and characterized by1H and13C NMR and FTIR spectroscopy. Under the experimental conditions used, the NMR data showed unequivocally that quaternarization ofN-alkyl-N?-methyl piperazine by the reaction with ethyl bromide occurred exclusively at the nitrogen atom bearing the methyl group due to

L. H. Gan; G. Roshan Deen; Y. Y. Gan; C. H. Chew

1996-01-01

49

Detection of 1-benzylpiperazine, 1-(3-trifluoromethylphenyl)-piperazine, and 1-(3-chlorophenyl)-piperazine in 3,4-methylenedioxymethamphetamine-positive urine samples.  

PubMed

Historically, ecstasy tablets contained 3,4-methylenedioxymethamphetamine (MDMA) as the psychoactive component. In recent years, the Drug Enforcement Administration (DEA) and other law enforcement agencies have seized ecstasy tablets that are comprised of psychoactive drugs or drug mixtures other than MDMA. Many jurisdictions have reported the presence of piperazine derivatives including 1-benzylpiperazine (BZP), 1-(3-trifluoromethylphenyl)-piperazine (TFMPP), and 1-(3-chlorophenyl)-piperazine (mCPP) in ecstasy tablets. These piperazine derivatives produce stimulant and psychoactive effects similar to those produced by MDMA, amphetamine, and methamphetamine. In many countries, their use is not controlled, and therefore they have become a legal alternative to MDMA. For this study, a targeted population of 251 MDMA-positive urine samples were analyzed for designer drugs, including the piperazine derivatives. A basic liquid-liquid extraction followed by pentafluoropropionic anhydride (PFPA) derivatization and a full scan (m/z 42-550) gas chromatography-mass spectrometry analysis was used to screen the urine samples for 33 designer drugs. Overall, in 36% of the specimens analyzed, a stimulant or psychoactive compound other than MDMA and 3,4-methylenedioxyamphetamine (MDA) was detected. BZP, TFMPP, and mCPP were detected in 15%, 7%, and 1% of the samples, respectively. PMID:21819791

Dickson, Amber J; Vorce, Shawn P; Holler, Justin M; Lyons, Timothy P

2010-10-01

50

4-(4-Methyl-phenyl-sulfon-yl)piperazin-1-ium tri-fluoro-acetate  

PubMed Central

In the title salt, C11H17N2O2S+·CF3COO?, the cation is protonated at the secondary piperazine N atom. The dihedral angle between the benzene ring and the piperazine mean plane is 85.54?(10)°. In the crystal, cations and anions are connected by two types of strong N—H?O hydrogen bonds into chains extending along [101]. The chains are further assembled into (10-1) layers via stacking inter­actions between benzene rings of the cations [centroid–centroid distance = 3.7319?(13)?Å] and a C—H?O inter­action involving a piperazine C—H group and a sulfonyl O atom. Another C—H?O inter­action between the piperazine ring and the sulfonyl group connects the ions into a three-dimensional network.

Sreenivasa, S.; Mohan, N. R.; Madhu Chakrapani Rao, T.; Suchetan, P. A.; Palakshamurthy, B. S.; Vijithkumar

2013-01-01

51

Palladium-catalyzed alkene carboamination reactions for the synthesis of substituted piperazines  

PubMed Central

A strategy for the stereoselective preparation of enantiomerically enriched cis-2,6-disubstituted piperazines from amino acid precursors is described. The target compounds are generated in 95–99% ee with good to excellent levels of diastereoselectivity (usually 14:1 to >20:1) using Pd-catalyzed carboamination reactions between aryl or alkenyl halides and substituted ethylenediamine derivatives to form the heterocyclic rings. The synthesis requires only 4–5 steps from commercially available amino acids, and allows for the modular construction of piperazines bearing different substituents at N1, N4, C2, and C6. The use of this strategy for the construction of 2,3-disubstituted piperazines, fused bicyclic piperazines, and tetrahydroquinoxalines is also reported. In addition, the mechanism of the key carboamination reactions are discussed, and new models that predict and explain the stereochemical outcome of these transformations are presented.

Nakhla, Josephine S.; Schultz, Danielle M.; Wolfe, John P.

2009-01-01

52

Accurate HPLC Determination of Piperazine Residues in the Presence of other Secondary and Primary Amines  

Microsoft Academic Search

A reversed and normal phase HPLC separation technique with diode array detection was used for the investigation of interactions of diethylenediamine (piperazine) and its DNS derivative with different adsorbents, used as HPLC packings. The chromatography in reversed phase mode with s deactivated C18 column (BakerBond C18 BDC, SUPELCOSIL™ LC?C18?DB) did not give positive results. Piperazine was not retained on the

2005-01-01

53

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

SciTech Connect

Solutions of amines are frequently used in gas-treating processes to remove acid 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 solubility and diffusivity of N{sub 2}O in (monoethanolamine + N-methyldiethanolamine + water) and in (monoethanolamine + 2-amino-2-methyl-l-propanol + water) were measured at 30, 35, and 40 C and at atmospheric pressure. Six (monoethanolamine + N-methyldiethanolamine + water) and five (monoethanolamine + 2-amino-2-methyl-l-propanol + water) systems were studied. The total amine mass percent in all cases was 30. The solubilities were measured by a solubility apparatus similar to that of Haimour and Sandall (1984). A wetted wall column absorber was used to obtain the diffusivity of N{sub 2}O in amines. The N{sub 2}O solubilities in amine solutions have been correlated on the basis of the excess Henry constant correlation of Wang et al. (1992). The N{sub 2}O analogy was used to estimate the solubility and diffusivity of CO{sub 2} in (monoethanolamine + N-methyldiethanolamine + water) and in (monoethanolamine + 2-amino-2-methyl-l-propanol + water).

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

1995-03-01

54

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

1996-05-01

55

Preliminary evaluation of anticonvulsant activity and neurotoxicity of some 1,4-substituted piperazine derivatives.  

PubMed

A series of 1,4-piperazine derivatives was synthesized and evaluated for anticonvulsant activity in the maximal electroshock seizure (MES) and subcutaneous pentylenetetrazole seizure threshold (ScMet) assays and for neurotoxicity (TOX). The compounds were only moderately effective. The anticonvulsant activity was accompanied by neurotoxicity. 1-[(4-Chlor-3-methylphenoxy)-acetyl]-4-(2-methoxyphenyl)-piperazine was also evaluated in six hertz seizure test (6-Hz) and showed good activity. At the dose of 100 mg/kg b. w. the compound produced 100% protection after 0.5 h without neurotoxic effect. PMID:19894654

Marona, Henryk; Gunia, Agnieszka; S?oczy?ska, Karolina; Rapacz, Anna; Filipek, Barbara; Ceg?a, Marek; Opoka, W?odzimierz

56

New metal phosphonates containing coordination piperazine or pyridyl groups  

SciTech Connect

Reactions of transition metal(II) salts with three aminophosphonic acids, 1-[(H{sub 2}O{sub 3}PCH{sub 2}){sub 2}NCH{sub 2}CH{sub 2}-]-piperazine-4-CH{sub 2}PO{sub 3}H{sub 2} (H{sub 6}L{sup 1}), 3-pyridyl-CH{sub 2}N(CH{sub 2}PO{sub 3}H{sub 2}){sub 2} (H{sub 4}L{sup 2}) and 4-pyridyl-CH{sub 2}N(CH{sub 2}PO{sub 3}H{sub 2}){sub 2} (H{sub 4}L{sup 3}) afforded three new metal phosphonates, namely, Cu(H{sub 4}L{sup 1}).2H{sub 2}O (1), Co(H{sub 3}L{sup 2}){sub 2}.H{sub 2}O (2) and [Co(H{sub 2}L{sup 3})(H{sub 2}O)].H{sub 2}O (3). The structure of compound 1 features a 1D chain in which the CuN{sub 2}O{sub 3} and CPO{sub 3} polyhedra are interconnected by bridging phosphonate ligands to form 1D chains. Compound 2 has a layered structure. The cobalt(II) ions in the octahedral coordination geometries and {l_brace}CPO{sub 3}{r_brace} tetrahedra are interconnected into an inorganic chain via -N(CH{sub 2}PO{sub 3}H){sub 2} moieties, and adjacent chains are further bridged by the coordination pyridyl groups of H{sub 3}L{sup 2} into a 2D layer. The structure of compound 3 features a 2D double layered structure, in which the Co(II) ions are interconnected by bridging phosphonate groups into a 1D chain along b-axis. Neighboring chains are interconnected by coordination pyridyl groups into a double layer perpendicular to the c-axis.

Song Junling [State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002 (China); Mao Jianggao [State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002 (China)]. E-mail: mjg@ms.fjirsm.ac.cn

2005-11-15

57

Synthesis and Chemistry of Some Furazano- and Furoxano(3,4-b)piperazines.  

National Technical Information Service (NTIS)

A series of N,N'-disubstituted furazano- and furoxano (3,4-B) piperazines have been syntheiszed from N,N'-disubstituted 2,3-piperazinedione dioximes by base-promoted dehydration and by basic potassium ferricyanide oxidation, respectively. The N,N'-disubst...

R. L. Willer D. W. Moore

1985-01-01

58

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 ...

59

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...

60

Synthesis and diversity analysis of lead discovery piperazine-2-carboxamide libraries  

Microsoft Academic Search

Summary A Lead Discovery Library of piperazine-2-carboxamide derivatives was produced for general screening. This paper discloses two novel solid phase synthetic routes used to produce 15 000 single compounds via the Irori directed sorting technique. Computational methods such as reagent clustering and library profiling were used to maximize reagent diversity and optimize pharmacokinetic parameters. The results of a four center

Timothy F. Herpin; George C. Morton; Allison K. Dunn; Paul R. Menard; Sheng Yu Tang; Joseph M. Salvino; Richard F. Labaudiniere

2000-01-01

61

Advanced Amine Solvent Formulations and Process Integration for Near-Term CO2 Capture Success  

SciTech Connect

This Phase I SBIR project investigated the economic and technical feasibility of advanced amine scrubbing systems for post-combustion CO2 capture at coal-fired power plants. Numerous combinations of advanced solvent formulations and process configurations were screened for energy requirements, and three cases were selected for detailed analysis: a monoethanolamine (MEA) base case and two “advanced” cases: an MEA/Piperazine (PZ) case, and a methyldiethanolamine (MDEA) / PZ case. The MEA/PZ and MDEA/PZ cases employed an advanced “double matrix” stripper configuration. The basis for calculations was a model plant with a gross capacity of 500 MWe. Results indicated that CO2 capture increased the base cost of electricity from 5 cents/kWh to 10.7 c/kWh for the MEA base case, 10.1 c/kWh for the MEA / PZ double matrix, and 9.7 c/kWh for the MDEA / PZ double matrix. The corresponding cost per metric tonne CO2 avoided was 67.20 $/tonne CO2, 60.19 $/tonne CO2, and 55.05 $/tonne CO2, respectively. Derated capacities, including base plant auxiliary load of 29 MWe, were 339 MWe for the base case, 356 MWe for the MEA/PZ double matrix, and 378 MWe for the MDEA / PZ double matrix. When compared to the base case, systems employing advanced solvent formulations and process configurations were estimated to reduce reboiler steam requirements by 20 to 44%, to reduce derating due to CO2 capture by 13 to 30%, and to reduce the cost of CO2 avoided by 10 to 18%. These results demonstrate the potential for significant improvements in the overall economics of CO2 capture via advanced solvent formulations and process configurations.

Fisher, Kevin S.; Searcy, Katherine; Rochelle, Gary T.; Ziaii, Sepideh; Schubert, Craig

2007-06-28

62

Kinetics of carbon dioxide absorption and desorption in aqueous alkanolamine solutions using a novel hemispherical contactor—I. Experimental apparatus and mathematical modeling  

Microsoft Academic Search

This two-parts paper summarizes the experimental and theoretical results of a comprehensive and first of its kind study on the kinetics of carbon dioxide (CO2) absorption and desorption in and from aqueous solutions of monoethanolamine (MEA), diethanolamine (DEA), methyl-diethanolamine (MDEA) and 2-amino-2-methyl-1-propanol (AMP) and their mixtures (i.e., MEA+AMP, MEA+MDEA, DEA+AMP and DEA+MDEA). Part-1 of this paper presents a detailed design

Aqil Jamal; Axel Meisen; C. Jim Lim

2006-01-01

63

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

Microsoft Academic Search

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, 1H NMR and electronic spectral

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

2011-01-01

64

GC-MS studies on the regioisomeric 2,3- and 3,4-methylenedioxyphenethylamines related to MDEA, MDMMA, and MBDB.  

PubMed

Three regioisomeric 3,4-methylenedioxyphenethylamines having the same molecular weight and major mass spectral fragments of equal mass have been reported as drugs of abuse in forensic studies in recent years. These compounds are 3,4-methylenedioxy-N-ethylamphetamine (MDEA), 3,4-methylenedioxy-N-N-dimethylamphetamine (MDMMA), and N-methyl-1-(3,4-methylenedioxyphenyl)-2-butanamine (MBDB). The mass spectra of the regioisomers (2,3-methylenedioxyphenethylamines) are essentially equal to the three compounds reported as drugs of abuse. This paper reports the synthesis, mass spectral characterization, and chromatographic analysis of these six regioisomeric amines. The six regioisomeric methylenedioxyphenethylamines are synthesized from commercially available starting materials. The electron impact mass spectra of these regioisomers show some variation in the relative intensity of the major ions with only a couple of minor ions that may indicate side chain specific fragments. Differentiation by mass spectrometry is only possible after the formation of the perfluoroacyl derivatives, pentafluoropropionylamides (PFPA) and heptafluorobutrylamides (HFBA). Gas chromatographic separation on non-polar stationary phases (Rtx-1 and Rtx-5) is not successful at resolving the three 3,4-methylenedioxyphenethylamines from the three 2,3-methylenedioxyphenethylamines as the underivatized amines. The six underivatized amines are resolved on the more polar trifluoropropylmethyl polysiloxane Rtx-200 stationary phase as well as a permethylated beta-cyclodextran Rtx-bDEX stationary phase. Gas chromatographic separation is successful at resolving the four PFPA and the four HFBA derivatives on the Rtx-200 stationary phase as well as the permethylated beta-cyclodextran stationary phase. The 2,3-methylenedioxyphenethylamine derivatives (compounds 4 and 6) eluted before the 3,4-methylenedioxyphenethylamine derivatives (compounds 1 and 3) as both the PFPA and HFBA derivatives. PMID:17555628

Thigpen, Ashley; DeRuiter, Jack; Clark, C Randall

65

Cancer Cell Cytotoxicities of 1-(4-Substitutedbenzoyl)-4-(4-chlorobenzhydryl)piperazine Derivatives  

PubMed Central

A series of novel 1-(4-substitutedbenzoyl)-4-(4-chlorobenzhydryl)piperazine derivatives 5a–g was designed by a nucleophilic substitution reaction of 1-(4-chlorobenzhydryl)piperazine with various benzoyl chlorides and characterized by elemental analyses, IR and 1H nuclear magnetic resonance spectra. Cytotoxicity of the compounds was demonstrated on cancer cell lines from liver (HUH7, FOCUS, MAHLAVU, HEPG2, HEP3B), breast (MCF7, BT20, T47D, CAMA-1), colon (HCT-116), gastric (KATO-3) and endometrial (MFE-296) cancer cell lines. Time-dependent cytotoxicity analysis of compound 5a indicated the long-term in situ stability of this compound. All compounds showed significant cell growth inhibitory activity on the selected cancer cell lines.

Yarim, Mine; Koksal, Meric; Durmaz, Irem; Atalay, Rengul

2012-01-01

66

Cancer Cell Cytotoxicities of 1-(4-Substitutedbenzoyl)-4-(4-chlorobenzhydryl)piperazine Derivatives.  

PubMed

A series of novel 1-(4-substitutedbenzoyl)-4-(4-chlorobenzhydryl)piperazine derivatives 5a-g was designed by a nucleophilic substitution reaction of 1-(4-chlorobenzhydryl)piperazine with various benzoyl chlorides and characterized by elemental analyses, IR and (1)H nuclear magnetic resonance spectra. Cytotoxicity of the compounds was demonstrated on cancer cell lines from liver (HUH7, FOCUS, MAHLAVU, HEPG2, HEP3B), breast (MCF7, BT20, T47D, CAMA-1), colon (HCT-116), gastric (KATO-3) and endometrial (MFE-296) cancer cell lines. Time-dependent cytotoxicity analysis of compound 5a indicated the long-term in situ stability of this compound. All compounds showed significant cell growth inhibitory activity on the selected cancer cell lines. PMID:22942690

Yarim, Mine; Koksal, Meric; Durmaz, Irem; Atalay, Rengul

2012-06-28

67

Multimetallic assemblies using piperazine-based dithiocarbamate building blocks.  

PubMed

Treatment of cis-[RuCl2(dppm)2] (dppm = bis(diphenylphosphino)methane) with dithiocarbamates, NaS2CNR2 (R = Me, Et) and [H2NC5H10][S2CNC5H10], yields cations [Ru(S2CNR2)2(dppm)2](+) and [Ru(S2CNC5H10)2(dppm)2](+), respectively. The zwitterions S2CNC4H8NHR (R = Me, Et) react with the same metal complex in the presence of base to yield [Ru(S2CNC4H8NR)(dppm)2](+). Piperazine or 2,6-dimethylpiperazine reacts with carbon disulfide to give the zwitterionic dithiocarbamate salts H2NC4H6(R2-3,5)NCS2 (R = H; R = Me), which form the complexes [Ru(S2CNC4H6(R2-3,5)NH2)(dppm)2](2+) on reaction with cis-[RuCl2(dppm)2]. Sequential treatment of [Ru(S2CNC4H8NH2)(dppm)2](2+) with triethylamine and carbon disulfide forms the versatile metalla-dithiocarbamate complex [Ru(S2CNC4H8NCS2)(dppm)2] which reacts readily with cis-[RuCl2(dppm)2] to yield [{Ru(dppm)2}2(S2CNC4H8NCS2)]. Reaction of [Ru(S2CNC4H8NCS2)(dppm)2] with [Os(CH=CHC6H4Me-4)Cl(CO)(BTD)(PPh3)2] (BTD = 2,1,3-benzothiadiazole), [Pd(C6H4CH2NMe2)Cl]2, [PtCl2(PEt3)2], and [NiCl2(dppp)] (dppp = 1,3-bis(diphenylphosphino)propane) results in the heterobimetallic complexes [(dppm)2Ru(S2CNC4H8NCS2)ML(n))](m+) (ML(n) = Os(CH=CHC6H4Me-4)(CO)(PPh3)2](+), m = 1; ML(n) = Pd(C,N-C6H4CH2NMe2), m = 1; ML(n) = Pt(PEt3)2, m = 2; ML(n) = Ni(dppp), m = 2). Reaction of [NiCl2(dppp)] with H2NC4H8NCS2 yields the structurally characterized compound, [Ni(S2CNC4H8NH2)(dppp)](2+), which reacts with base, CS2, and cis-[RuCl2(dppm)2] to provide an alternative route to [(dppm)2Ru(S2CNC4H8NCS2)Ni(dppp)](+). A further metalla-dithiocarbamate based on cobalt, [CpCo(S2CNC4H8NH2)(PPh3)](2+), is formed by treatment of CpCoI2(CO) with S2CNC4H8NH2 followed by PPh3. Further reaction with NEt3, CS2, and cis-[RuCl2(dppm)2] yields [(Ph3P)CpCo(S2CNC4H8NCS2)Ru(dppm)2](2+). Heterotrimetallic species of the form [{(dppm)2Ru(S2CNC4H8NCS2)}2M](2+) result from the reaction of [Ru(S2CNC4H8NCS2)(dppm)2] and M(OAc)2 (where M = Ni, Cu, Zn). Reaction of [Ru(S2CNC4H8NCS2)(dppm)2] with Co(acac)3 and LaCl3 results in the formation of the compounds [{(dppm)2Ru(S2CNC4H8NCS2)}3Co](3+) and [{(dppm)2Ru(S2CNC4H8NCS2)}3La](3+), respectively. The electrochemical behavior of selected examples is also reported. PMID:18811147

Wilton-Ely, James D E T; Solanki, Dina; Knight, Edward R; Holt, Katherine B; Thompson, Amber L; Hogarth, Graeme

2008-09-24

68

Melanocortin subtype-4 receptor agonists containing a piperazine core with substituted aryl sulfonamides  

Microsoft Academic Search

The biological activity for a set of melanocortin-4 receptor (MC4R) agonists containing a piperazine core with an ortho-substituted aryl sulfonamide is described. Compounds from this set had binding and functional activities at MC4R less than 30nM. The most selective compound in this series was >25,000-fold more potent at MC4R than MC3R, and 490-fold more potent at MC4R than MC5R. This

Christopher Fotsch; Nianhe Han; Premilla Arasasingham; Yunxin Bo; Michelle Carmouche; Ning Chen; James Davis; Martin H. Goldberg; Clarence Hale; Feng-Yin Hsieh; Michael G. Kelly; Qingyian Liu; Mark H. Norman; Duncan M. Smith; Markian Stec; Nuria Tamayo; Ning Xi; Shimin Xu; Anthony W. Bannon; James W. Baumgartner

2005-01-01

69

N-(4-Chloro-phen-yl)-4-methyl-piperazine-1-carboxamide  

PubMed Central

In the title compound, C12H16ClN3O, the piperazine ring has a chair conformation. Within this ring, the N-methyl nitro­gen atom has a pyramidal geometry and the N-carboxamide nitro­gen atom is almost planar (bond-angle sum = 359.8°). In the crystal, the mol­ecules are linked by N—H?O hydrogen bonds into C(4) chains propagating in [010].

Li, Yu-Feng; Wang, Wen-Mei

2011-01-01

70

Synthesis and Pharmacological Properties of 1Aryl4-(3?4?,5?-trimethoxybenzoyl)piperazines  

Microsoft Academic Search

A series of 1-aryl-4-(3?,4?,5?-trimethoxybenzoyl)piperazines (IIa - IIg) having structures containing 3,4,5-trimethoxybenzoyl fragments were synthesized and characterized. Compounds IIa and IIc - IIg demonstrated weak anxiolytic properties and moderately decreased the spontaneous motor activity in rats. Compound IIb exhibited anxiolytic activity comparable with that of buspirone but, in contrast to this reference drug, increased the motor activity of test animals.

S. G. Soboleva; A. F. Galatin; T. L. Karaseva; A. V. Golturenko; S. A. Andronati

2005-01-01

71

Benzothiophene piperazine and piperidine urea inhibitors of fatty acid amide hydrolase (FAAH).  

PubMed

The synthesis and structure-activity relationships (SAR) of a series of benzothiophene piperazine and piperidine urea FAAH inhibitors is described. These compounds inhibit FAAH by covalently modifying the enzyme's active site serine nucleophile. Activity-based protein profiling (ABPP) revealed that these urea inhibitors were completely selective for FAAH relative to other mammalian serine hydrolases. Several compounds showed in vivo activity in a rat complete Freund's adjuvant (CFA) model of inflammatory pain. PMID:19386497

Johnson, Douglas S; Ahn, Kay; Kesten, Suzanne; Lazerwith, Scott E; Song, Yuntao; Morris, Mark; Fay, Lorraine; Gregory, Tracy; Stiff, Cory; Dunbar, James B; Liimatta, Marya; Beidler, David; Smith, Sarah; Nomanbhoy, Tyzoon K; Cravatt, Benjamin F

2009-03-24

72

Benzothiophene piperazine and piperidine urea inhibitors of fatty acid amide hydrolase (FAAH)  

Microsoft Academic Search

The synthesis and structure–activity relationships (SAR) of a series of benzothiophene piperazine and piperidine urea FAAH inhibitors is described. These compounds inhibit FAAH by covalently modifying the enzyme’s active site serine nucleophile. Activity-based protein profiling (ABPP) revealed that these urea inhibitors were completely selective for FAAH relative to other mammalian serine hydrolases. Several compounds showed in vivo activity in a

Douglas S. Johnson; Kay Ahn; Suzanne Kesten; Scott E. Lazerwith; Yuntao Song; Mark Morris; Lorraine Fay; Tracy Gregory; Cory Stiff; James B. Dunbar Jr.; Marya Liimatta; David Beidler; Sarah Smith; Tyzoon K. Nomanbhoy; Benjamin F. Cravatt

2009-01-01

73

THERMODYNAMICS AND KINETICS OF AQUEOUS PIPERAZINE WITH POTASSIUM CARBONATE FOR CARBON DIOXIDE ABSORPTION  

Microsoft Academic Search

This work proposes an innovative blend of potassium carbonate (KCO) and piperazine (PZ) as a solvent for CO removal from combustion flue gas in an absorber\\/stripper. The equilibrium partial pressure and the rate of absorption of CO were measured in a wetted-wall column in 0.0 to 6.2 m K{sup +} and 0.6 to 3.6 m PZ at 25 to 110

John T. Cullinane

2005-01-01

74

Piperazine sulfonamide BACE1 inhibitors: Design, synthesis, and in vivo characterization  

SciTech Connect

With collaboration between chemistry, X-ray crystallography, and molecular modeling, we designed and synthesized a series of novel piperazine sulfonamide BACE1 inhibitors. Iterative exploration of the non-prime side and S2{prime} sub-pocket of the enzyme culminated in identification of an analog that potently lowers peripheral A{beta}{sub 40} in transgenic mice with a single subcutaneous dose.

Cumming, Jared; Babu, Suresh; Huang, Ying; Carrol, Carolyn; Chen, Xia; Favreau, Leonard; Greenlee, William; Guo, Tao; Kennedy, Matthew; Kuvelkar, Reshma; Le, Thuy; Li, Guoqing; McHugh, Nansie; Orth, Peter; Ozgur, Lynne; Parker, Eric; Saionz, Kurt; Stamford, Andrew; Strickland, Corey; Tadesse, Dawit; Voigta, Johannes; Zhang, Lili; Zhang, Qi (Ligand); (Merck)

2010-08-17

75

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.

2012-01-01

76

Calorimetric determination of enthalpy changes for proton ionization of N-[2-hydroxyethyl]piperazine- N?-[2-ethane sulfonic acid] (HEPES) and N-[2-hydroxyethyl]piperazine- N?-[2-hydroxypropane sulfonic acid] (HEPPSO) in water–methanol mixtures  

Microsoft Academic Search

Enthalpies for the two proton ionizations of the biochemical buffers N-[2-hydroxyethyl]piperazine-N?-[2-ethane sulfonic acid] (HEPES) and N-[2-hydroxyethyl]piperazine-N?-[2-hydroxypropane sulfonic acid] (HEPPSO) were obtained in water–methanol mixtures with methanol mole fraction (Xm) from 0 to 0.360. With increasing methanol, the ionization enthalpy for the first proton (?H1) of HEPES increased steadily from 8.4 to 15.3kJmol?1 whereas that for HEPPSO rose to a maximum

F. H. Jumean; N. M. Abdo

2006-01-01

77

Thermodynamic Study of Corrosion and Inhibitor Adsorption Processes onto C38 Steel/piperazines/phosphoric Acid Systems  

NASA Astrophysics Data System (ADS)

This paper describes the inhibition effect of 1-benzyl piperazine (P1) and bis(1-benzyl piperazine) thiuram disulfide (P2) towards the corrosion of C38 steel in 5.5 M H3PO4 solution by potentiodynamic polarization and weight loss methods. The influence of inhibitor concentration and temperature on inhibitory behavior of P2 were investigated. The inhibition efficiency (IE) was found to be dependent on the type of piperazine and its concentration. The IE for 10-3 M P2 in 5.5 M H3PO4 is greater than 98%. Polarization studies clearly revealed that both P1 and P2 act as mixed-type inhibitors. Adsorption isotherms were fitted by the Langmuir isotherm. Adsorption energies (? Go{ ads} and ? Ho{ ads}) were evaluated. Kinetic parameters were determined.

Ousslim, A.; Ouniti, A.; Bekkouch, K.; Elidrissi, A.; Hammouti, B.

78

Binding of the amphetamine-like 1-phenyl-piperazine to monoamine transporters.  

PubMed

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

Severinsen, Kasper; Kraft, Johan F; Koldsø, Heidi; Vinberg, Katrine A; Rothman, Richard B; Partilla, John S; Wiborg, Ove; Blough, Bruce; Schiøtt, Birgit; Sinning, Steffen

2012-06-10

79

1-{4-[Bis(4-fluoro-phen-yl)meth-yl]piperazin-1-yl}ethanone  

PubMed Central

In the title compound, C19H20F2N2O, the six-membered piperazine group adopts a slightly distorted chair conformation. The dihedral angle between the mean planes of the two benzene rings is 73.4?(6)°. The mean plane of the ethanone group is twisted from the mean planes of the two benzene rings by 66.7?(8) and 86.2?(6)°. In the crystal, C—H?O and C—H?F inter­actions link the molecules, forming a three-dimensional structure.

Dayananda, A. S.; Yathirajan, H. S.; Keeley, Amanda C.; Jasinski, Jerry P.

2012-01-01

80

1-{4-[Bis(4-fluoro-phen-yl)meth-yl]piperazin-1-yl}ethanone.  

PubMed

In the title compound, C(19)H(20)F(2)N(2)O, the six-membered piperazine group adopts a slightly distorted chair conformation. The dihedral angle between the mean planes of the two benzene rings is 73.4?(6)°. The mean plane of the ethanone group is twisted from the mean planes of the two benzene rings by 66.7?(8) and 86.2?(6)°. In the crystal, C-H?O and C-H?F inter-actions link the molecules, forming a three-dimensional structure. PMID:22798893

Dayananda, A S; Yathirajan, H S; Keeley, Amanda C; Jasinski, Jerry P

2012-06-27

81

Equilibrium solubility of carbon dioxide in (2-amino-2-methyl-1-propanol + piperazine + water)  

Microsoft Academic Search

In this work, a new set of values for the solubility of carbon dioxide in aqueous mixture containing different concentrations of 2-amino-2-methyl-1-propanol (AMP), a sterically-hindered amine, and piperazine (PZ), an activator, are presented. The results were carefully determined using a 1.0dm3 stainless steel vapour-recirculation equilibrium cell at T=(313.2, 333.2, and 353.2)K, and pressures up to 152kPa. The AMP concentrations in

Zih-Yi Yang; Allan N. Soriano; Alvin R. Caparanga; Meng-Hui Li

2010-01-01

82

1-(3,4-Di-fluoro-benz-yl)-4-(4-methyl-phenyl-sulfon-yl)piperazine.  

PubMed

In the title compound, C18H20F2N2O2S, the central piperazine ring adopts a chair conformation. The dihedral angle between the two benzene rings is 40.20°, whereas those between the piperazine ring (considering the best fit plane through all the non-H atoms) and the sulfonyl-bound benzene and di-fluoro-benzene rings are 74.96 and 86.16°, respectively. In the crystal, mol-ecules are stacked along the a axis through weak C-H?O and C-H?F inter-actions. PMID:24046720

Sreenivasa, S; Anitha, H C; Suchetan, P A; Palakshamurthy, B S; Savanur, J; Tonannavar, J

2013-06-29

83

Imidazole piperazines: SAR and development of a potent class of cyclin-dependent kinase inhibitors with a novel binding mode.  

PubMed

A piperazine series of cyclin-dependent kinase (CDK) inhibitors have been identified. The compounds exhibit excellent physiochemical properties and a novel binding mode, whereby a bridging interaction via a water molecule with Asp 86 of CDK2, leads to selectivity for the CDK family of enzymes over other kinases. Piperazines 2e and 2i were subsequently shown to inhibit tumour growth when dosed orally in a nude mouse xenograft study. Additional chemical series that exploit this unexpected interaction with Asp 86 are also described. PMID:18617397

Finlay, M Raymond V; Acton, David G; Andrews, David M; Barker, Andrew J; Dennis, Michael; Fisher, Eric; Graham, Mark A; Green, Clive P; Heaton, David W; Karoutchi, Galith; Loddick, Sarah A; Morgentin, Rémy; Roberts, Andrew; Tucker, Julie A; Weir, Hazel M

2008-06-12

84

1-(3,4-Di-fluoro-benz-yl)-4-(4-methyl-phenyl-sulfon-yl)piperazine  

PubMed Central

In the title compound, C18H20F2N2O2S, the central piperazine ring adopts a chair conformation. The dihedral angle between the two benzene rings is 40.20°, whereas those between the piperazine ring (considering the best fit plane through all the non-H atoms) and the sulfonyl-bound benzene and di­fluoro­benzene rings are 74.96 and 86.16°, respectively. In the crystal, mol­ecules are stacked along the a axis through weak C—H?O and C—H?F inter­actions.

Sreenivasa, S.; Anitha, H. C.; Suchetan, P. A.; Palakshamurthy, B. S.; Savanur, J.; Tonannavar, J.

2013-01-01

85

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.

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

2009-01-01

86

A comparative study of the action of gamma-aminobutyric acid and piperazine on the lobster muscle fibre and the frog spinal cord.  

PubMed Central

1 The effects of gamma-aminobutyric acid (GABA) and piperazine were compared on two in vitro preparations, the lobster muscle fibre and the frog spinal cord. 2 Both GABA and piperazine increased the membrane conductance of single lobster muscle fibres without changing the membrane potential; sigmoidal log dose-conductance curves for these agents were obtained and a similar model expressed the receptor interaction of both substances. 3 The actions of GABA and piperazine on lobster muscle were antagonized by picrotoxin and were Cl-dependent. 4 In the frog spinal cord GABA depolarized the dorsal roots presumably by mimicking the activity of the transmitter depolarizing the primary afferents; sigmoidal log dose-response curves for GABA were obtained. 5 On the dorsal roots piperazine produced either depolarizations or biphasic responses; these were mainly indirect effects as was shown by experiments in the presence of tetrodotoxin (TTX). 6 The effects of GABA on the dorsal root (in TTX-treated cords) were antagonized by picrotoxin whereas those of piperazine were more resistant to this alkaloid. The GABA-induced responses appeared to be largely Na+-dependent while both Na+ and Cl- seemed to mediate the effects of piperazine. 7 It is proposed that piperazine has GABA-agonist activity on lobster muscle but little GABA-like activity on the frog spinal cord.

Constanti, A; Nistri, A

1976-01-01

87

Catalytic and stoichiometric approaches to the desymmetrisation of centrosymmetric piperazines by enantioselective acylation: a total synthesis of dragmacidin A.  

PubMed

The enantioselective desymmetrisation of centrosymmetric piperazines was investigated using both catalytic and stoichiometric asymmetric acylation approaches. The catalytic approach involved the desymmetrisation of 2,5-trans-dimethylpiperazine under the control of chiral DMAP analogues. With one equivalent of piperazine, relative to the acylating agent, low yields of products were obtained in up to 70% ee. It was shown that an inevitable 'proof reading' effect was occurring which increased the enantiomeric excess of the desymmetrised product through its kinetic resolution. The desymmetrisation of centrosymmetric piperazines with chiral acylating agents [(1R,2R)-N-formyl-1,2-bis(pentafluoro-benzenesulfonamido)cyclohexane and (1R,2R)-N-acetyl-1,2-bis(trifluoromethanesulfonamido)-cyclohexane] was also studied. The yield and enantioselectivity of the process was highly dependent on the solvent used and the substitution of the piperazine. However, in some cases, good yields of enantiomerically enriched products could be obtained (up to 87% based on the limiting chiral reagent) in good enantiomeric excesses (up to 84% ee). The approach was exploited in the total synthesis of Dragmacidin A. PMID:17312969

Anstiss, Mark; Nelson, Adam

2006-11-21

88

Cobalt 5-bromoisophthalate coordination polymers containing bis(pyridyl)piperazine-type long spanning ligands and water molecule aggregations  

NASA Astrophysics Data System (ADS)

Divalent cobalt coordination polymers containing long-spanning bis(pyridyl)piperazine and 5-bromoisophthalate (Brip) ligands have been hydrothermally synthesized and structurally characterized by single-crystal X-ray diffraction. {[Co(H2O)2(4-bpmp)2](HBrip)2·14H2O}n (1, 4-bpmp = bis(4-pyridylmethyl)piperazine), and {[Co(Brip)(H2O)3(4-bpfp)]·6.5H2O}n (2, 4-bpfp = bis(4-pyridylformyl)piperazine) both show 1-D coordination polymer connectivity, but with different intriguing water molecule aggregations. An unprecedented T4(4)6(6)6(6)10(8) classification water tape is seen in 1, while a discrete 11-molecule water cluster is observed in 2. {[Co2(Brip)2(H2O)4(3-bpmp)]·4H2O}n (3, 3-bpmp = bis(3-pyridylmethyl)piperazine) manifests a 2D + 2D ? 3D mutually inclined interpenetrated system of parallel sets of (4,4) rhomboid grids, with isolated water molecule pairs.

Meyer, Jodi L.; Rogers, Ciana M.; LaDuca, Robert L.

2012-11-01

89

Design, Synthesis and Biological Evaluation of Novel Piperazine Derivatives as CCR5 Antagonists  

PubMed Central

By using a fragment-assembly strategy and bioisosteric-replacement principle, a series of novel piperazine derivatives were designed, synthesized, and evaluated for their cellular target-effector fusion activities and in vitro antiviral activities against HIV-1. Preliminary structure-activity relationships (SARs) of target compounds were concluded in this study, and five compounds were found to exhibited medium to potent CCR5 fusion activities with IC50 values in low micromolar level. Among evaluated compounds, 23 h was found to be a CCR5 antagonist with an IC50 value of 6.29 µM and an anti-HIV-1 inhibitor with an IC50 value of 0.44 µM.

Liu, Tao; Weng, Zhiyong; Dong, Xiaowu; Chen, Linjie; Ma, Ling; Cen, Shan; Zhou, Naiming; Hu, Yongzhou

2013-01-01

90

Synthesis and antiproliferative evaluation of piperazine-1-carbothiohydrazide derivatives of indolin-2-one.  

PubMed

By varying the substituents (R(1)) at the indolin-2-one scaffold, a series of indolin-2-one derivatives bearing 4-phenylpiperazine-1-carbothiohydrazide moiety at the C3-position were synthesized and evaluated for their antiproliferative activity against three human cancer cell lines. We further selected the 5-chloroindolin-2-one moiety for the extension to another series of compounds by varying the substituents (R(2)) at the phenyl group connected with the piperazine ring. Among all the compounds synthesized, 6d and 6l were most potent with IC50 values of 3.59 and 5.58 ?M, respectively against A549 lung cancer cells, while 5f and 6l possessed IC50 values of 3.49 and 4.57 ?M, respectively against HCT-116 colon cancer cells which were comparable to that of Sunitinib, an indolin-2-one derivative in cancer therapy. PMID:23602441

Lin, Hui-Hui; Wu, Wei-Yao; Cao, Sheng-Li; Liao, Ji; Ma, Li; Gao, Man; Li, Zhong-Feng; Xu, Xingzhi

2013-04-04

91

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

92

The Synthesis and Evaluation of N-carbonyl Piperazine as a Hydrochloric Acid Corrosion Inhibitor for High Protective 13Cr Steel in an Oil Field  

Microsoft Academic Search

A new inhibitor—N-carbonyl piperazine aimed at anticorrosion of high protective 13Cr steel was synthesized by electrochemistry together with ionic liquid. Its molecule structure was analyzed by gas chromatography\\/mass spectrometry and infrared spectroscopy. On that base, the inhibition mechanism of N-carbonyl piperazine on the corrosion of high protective 13Cr steel in 4 M HCl had been studied by polarization, electrochemical impedance

J. T. Zhang; Z. Q. Bai; J. Zhao; Y. R. Feng; Y. Wang

2012-01-01

93

The syntheses, characterization and properties of some metallophthalocyanine complexes substituted by ( N-(2-hydroxyethyl)piperazine)- N?-2-ethane sulfonic acid (HEPES)  

Microsoft Academic Search

Eight novel piperazine derivatives of metal (Zn, Co, Ni, Cu) phthalocyanine complexes were synthesized from two precursors obtained by the nucleophilic substitution of (N-(2-hydroxyethyl)piperazine)-N?-2-ethane sulfonic acid (HEPES) with both 3-nitro-phthalonitrile and 4-nitro-phthalonitrile. The complexes are characterized by IR, elemental analysis, 1H NMR and mass spectroscopy; the UV–vis absorption spectra, rate of singlet oxygen yields, fluorescence spectra and quantum yields of

Ziyang Huang; Jiandong Huang; Naisheng Chen; Jinling Huang

2008-01-01

94

3,3?-(Piperazine-1,4-diium-1,4-di-yl)di-propionate dihydrate  

PubMed Central

During the recrystallization of 3-[4-(2-carb­oxy­eth­yl)piperazin-1-yl]propionic acid, the carb­oxy­lic acid H atoms were transferred to the piperazine N atoms, forming the title compound, C10H18N2O4·2H2O, in which the zwitterion lies about an inversion center. In the crystal, bifurcated N—H?(O,O) hydrogen bonds connect the zwitterions into a two-dimensional framework parallel to (-102) forming R 4 4(30) rings. O—H?O hydrogen bonds involving the solvent water mol­ecules connect the two-dimensional framework into a three-dimensional network. In addition, weak C—H?O hydrogen bonds are observed.

Jin, Shouwen; Huang, Yanfei; Fang, Hao; Wang, Tianyi; Ding, Liangliang

2012-01-01

95

Synthesis and anti-inflammatory effects of new piperazine and ethanolamine derivatives of H(1)-antihistaminic drugs.  

PubMed

In addition to their antihistamine effects, H1-receptor antagonists possess pharmacological properties that are not uniformly distributed among this class of drugs, such as anti-inflammatory, anti-allergic and antiplatelet activities. In this paper, Cyclizine (1-benzhydryl-4-methyl-piperazine, I), bromodiphenhydramine (2-[(4-bromophenyl)-phenylmethoxy]-N, N-dimethylethanamine, II) and some of their new piperazine and ethanolamine derivatives (III-VIII) inducing changes in substitution of phenyl and amine moieties were synthesized and their acute and chronic antiinflammatory effects were evaluated by standard pharmacological tests. The results showed that substitution of phenyl by tolyl, anisol and cumene groups in piperazine family could remarkably decrease acute inflammation in these new drugs. Also, substitution of dimethylamine by morpholine group could not decrease this inflammation in new synthesized ethanolamine family. But the results from the cotton pellet-induced granuloma formation in rats showed that none of drugs (I-VIII) were effective to reduce the chronic inflammation. PMID:22876948

Ahmadi, Abbas; Khalili, Mohsen; Nafarie, Ali; Yazdani, Arash; Nahri-Niknafs, Babak

2012-10-01

96

Covalent inhibitors of fatty acid amide hydrolase (FAAH): A rationale for the activity of piperidine and piperazine aryl ureas  

PubMed Central

Recently, covalent drugs have attracted great interest in the drug discovery community, with successful examples that have demonstrated their therapeutic effects. Here, we focus on the covalent inhibition of the fatty acid amide hydrolase (FAAH), which is a promising strategy in the treatment of pain and inflammation. Among the most recent and potent FAAH inhibitors (FAAHi), there are the cyclic piperidine/piperazine aryl ureas. FAAH hydrolyzes efficiently the amide bond of these compounds, forming a covalent enzyme-inhibitor adduct. To rationalize this experimental evidence, we performed an extensive computational analysis centered on the piperidine-based PF750 (1) and the piperazine-based JNJ1661010 (2), two potent lead compounds used to generating covalent inhibitors as clinical candidates. We found that FAAH induces a distortion of the amide bond of the piperidine/piperazine aryl ureas. QM/MM ?ELUMO-HOMO energies indicate that the observed enzyme-induced distortion of the amide bond favors the formation of a covalent FAAH- inhibitor adduct. These findings could help in the rational structure-based design of novel covalent FAAHi.

Palermo, Giulia; Branduardi, Davide; Masetti, Matteo; Lodola, Alessio; Mor, Marco; Piomelli, Daniele; Cavalli, Andrea; De Vivo, Marco

2013-01-01

97

A chemical genetic approach identifies piperazine antipsychotics as promoters of CNS neurite growth on inhibitory substrates  

PubMed Central

Injury to the central nervous system (CNS) can result in lifelong loss of function due in part to the regenerative failure of CNS neurons. Inhibitory proteins derived from myelin and the astroglial scar are major barriers for the successful regeneration of injured CNS neurons. Previously, we described the identification of a novel compound, F05, which promotes neurite growth from neurons challenged with inhibitory substrates in vitro, and promotes axonal regeneration in vivo (Usher et al., 2010). To identify additional regeneration-promoting compounds, we used F05-induced gene expression profiles to query the Broad Institute Connectivity Map, a gene expression database of cells treated with >1,300 compounds. Despite no shared chemical similarity, F05-induced changes in gene expression were remarkably similar to those seen with a group of piperazine phenothiazine antipsychotics (PhAPs). In contrast to antipsychotics of other structural classes, PhAPs promoted neurite growth of CNS neurons challenged with two different glial derived inhibitory substrates. Our pharmacological studies suggest a mechanism whereby PhAPs promote growth through antagonism of calmodulin signaling, independent of dopamine receptor antagonism. These findings shed light on mechanisms underlying neurite-inhibitory signaling, and suggest that clinically approved antipsychotic compounds may be repurposed for use in CNS injured patients.

Johnstone, AL; Reierson, GW; Smith, RP; Goldberg, JL; Lemmon, VP; Bixby, JL

2012-01-01

98

Design, synthesis and evaluation of new thiazole-piperazines as acetylcholinesterase inhibitors.  

PubMed

In this study, some new 2-(4-substituted piperazine-1-yl)-N-[4-(2-methylthiazol-4-yl)phenyl]acetamide derivatives were synthesized. The synthesized compounds were screened for their anticholinesterase activity on acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) enzymes by in vitro Ellman's method. The structural elucidation of the compounds was performed by using IR, (1)H-NMR, (13)C-NMR and FAB(+)-MS spectral data and elemental analyses results. Biological assays revealed that at 0.1 µM concentration, the most active compounds against AChE were 5n, 5o and 5p that indicated 96.44, 99.83 and 89.70% inhibition rates, respectively. Besides, IC50 value of the compound 5o was determined as 0.011 µM, whereas IC50 value of standard drug donepezil was 0.054 µM. The synthesized compounds did not show any notable inhibitory activity against BChE. PMID:22871134

Yurtta?, Leyla; Kaplanc?kl?, Zafer As?m; Ozkay, Yusuf

2012-08-07

99

Synthesis and biological evaluation of 2-(4-fluorophenoxy)-2-phenyl-ethyl piperazines as serotonin-selective reuptake inhibitors with a potentially improved adverse reaction profile.  

PubMed

Three new 2-(4-fluorophenoxy)-2-phenyl-ethyl piperazines, 1-(3-chlorophenyl)-4-[2-(4-fluorophenoxy)-2-phenylethyl]-piperazine 7, 1-[2-(4-fluorophenoxy)-2-phenylethyl]-4-(2-methoxyphenyl)-piperazine 8, and 1-[2-(4-fluorophenoxy)-2-phenylethyl]-4-(3-trifluoromethylphenyl)-piperazine 9, modeled after the potent antidepressant fluoxetine and coupled with several functionalized piperazines, have been prepared by chemical synthesis as selective serotonin reuptake inhibitors (SSRIs) with a potentially improved adverse reaction profile. Typical SSRIs, although very effective in the treatment of depression, still face the troublesome side effect of sexual dysfunction. A number of pharmacological agents-notably, drugs in the piperazine class-have been used to reverse SSRI-induced sexual dysfunction, and evidence for developing an improved SSRI by coupling a fluoxetine congener with the pharmacophore of a reversal agent holds promise. Preliminary data indicates that the hydrochloride (HCl) salts 10, 11, and 12 each exhibit single-site binding at the site of the serotonin reuptake transporter (SERT). However, each of the three compounds are much less potent than typical SSRIs, showing micromolar (microM) affinity for the SERT with IC(50) values of 1.45 microM, 3.27 microM, and 9.56 microM, respectively. Further biological evaluation of compounds 10, 11, and 12 is needed before definitive conclusions can be made with regard to each compound's potential for use as an SSRI-type candidate which is devoid of sexual side effects. Nevertheless, the initial findings are quite encouraging, thus lending credence to the idea of hybridizing an SSRI congener with that of the pharmacophore of an agent known to reverse or treat SSRI-induced sexual dysfunction. PMID:15018922

Dorsey, James M; Miranda, Maria G; Cozzi, Nicholas V; Pinney, Kevin G

2004-03-15

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

2006-05-29

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

2007-03-31

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 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

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

Tri- and tetraurea piperazine cyclophanes: synthesis and complexation studies of preorganized and folded receptor molecules.  

PubMed

A series of symmetrical tri- and tetrameric N-ethyl- and N-phenylurea-functionalized cyclophanes have been prepared in nearly quantitative yields (86-99?%) from the corresponding tri- and tetraamino-functionalized piperazine cyclophanes and ethyl or phenyl isocyanates. Their conformational and complexation properties have been studied by single-crystal X-ray diffraction, variable-temperature NMR spectroscopy, and ESI-MS analysis. The rigid 27-membered trimeric cyclophane skeleton assisted by a seam of intramolecular hydrogen bonds results in a preorganized ditopic recognition site with an all-syn conformation of the urea moieties that, complemented by a lipophilic cavity of the cyclophane, binds molecular and ionic guests as well as ion pairs. The all-syn conformation persists in acidic conditions and the triprotonated triurea cyclophane binds an unprecedented anion pair, H(2)PO(4)(-)???HPO(4)(2-), in the solid state. The tetra-N-ethylurea cyclophane is less rigid and demonstrates an induced-fit recognition of diisopropyl ether in the solid state. The guest was encapsulated within the lipophilic interior of a quasicapsule, formed by intramolecular hydrogen-bond-driven folding of the 36-membered cyclophane skeleton. In the gas phase, the essential role of the urea moieties in the binding was demonstrated by the formation of monomeric 1:1 complexes with K(+), TMA(+), and TMP(+) as well as the ion-pair complexes [KI+K](+), [TMABr+TMA](+) and [TMPBr+TMP](+). In the positive-mode ESI-MS analysis, ion-pair binding was found to be more pronounced with the larger tetraurea cyclophanes. In the negative mode, owing to the large size of the binding site, a general binding preference towards larger anions, such as the iodide, over smaller anions, such as the fluoride, was observed. PMID:21077059

Raatikainen, Kari; Beyeh, N Kodiah; Rissanen, Kari

2010-12-27

105

Al(OTf)(3)-mediated epoxide ring-opening reactions: toward piperazine-derived physiologically active products.  

PubMed

Al(OTf)(3) is a good catalyst for the ring opening of epoxides, forming beta-amino alcohols bearing the piperazine motif. Two different strategies were examined, where the glycidyl ether resided on one-half of the molecule or the other, allowing insight into a best-case approach for the ring-opening step. Each half of the molecule contained an heteroatom that could be used either to attach the glycidyl moiety or as the nucleophile in the ring-opening reaction, for the same set of reagents, allowing this approach. PMID:19916484

Williams, D Bradley G; Cullen, Adam

2009-12-18

106

The tertiary amine nitrogen atom of piperazine sulfonamides as a novel determinant of potent and selective beta3-adrenoceptor agonists.  

PubMed

Novel compounds were prepared in fair to good yields as human beta(3)-adrenoceptor (beta(3)-AR) agonists. In particular, aryloxypropanolamines 7 a-d (EC(50)=0.57-2.1 nM) and arylethanolamines 12 a,b,e (EC(50)=6.38-19.4 nM) were designed to explore the effects of modifications at the right-hand side of these molecules on their activity as beta(3)-AR agonists. Piperidine sulfonamides 15 a-c, e-g (EC(50)=6.1-36.2 nM) and piperazine sulfonamide derivatives 20-29 (EC(50)=1.79-49.3 nM) were examined as compounds bearing a non-aromatic linker on the right- and left-hand sides of the molecules. Some piperazine sulfonamides were found to be potent and selective beta(3)-AR agonists, even if the amine nitrogen atom is tertiary and not secondary, as is the case for all beta(3)-AR agonists reported so far. (S)-3-{4-{N-{4-{2-[2-Hydroxy-3-(4-hydroxyphenoxy)propylamino]ethyl}phenyl}sulfamoyl}phenoxy}propanoic acid (7 d; EC(50)=0.57 nM), (R)-N-{4-[2-(2-hydroxy-2-phenylethylamino)ethyl]phenyl}-4-(3-octylureido)benzenesulfonamide (12 e; EC(50)=6.38 nM), (R)-2-[1-(4-methoxyphenylsulfonyl)piperidin-4-ylamino]-1-phenylethanol (15 f; EC(50)=6.1 nM), and (S)-4-{2-hydroxy-3-[4-(4-methoxyphenylsulfonyl)piperazin-1-yl]propoxy}phenol (25; EC(50)=1.79 nM) were found to be the most potent beta(3)-AR agonists of the aryloxypropanolamine, arylethanolamine, piperidine sulfonamide, and piperazine sulfonamide classes, respectively. The two most potent compounds were identified as possible candidates for further development of beta(3)-AR agonists useful in the treatment of beta(3)-AR-mediated pathological conditions. PMID:19882697

Perrone, Maria Grazia; Bleve, Laura; Santandrea, Ernesto; Vitale, Paola; Niso, Mauro; Scilimati, Antonio

2009-12-01

107

Metabolic and kinetic aspects of 1-(piperidinoacetyl)-4-(4-iodophenyl)piperazine: a potential brain imaging agent  

SciTech Connect

As part of a program for the development of brain perfusion imaging agents, (/sup 125/I)-1-(Piperidinoacetyl)-4-(4-iodophenyl)piperazine (IPAP), was identified as having the best combination of brain uptake, retention and selectivity. The purpose of the present study was to investigate the metabolic and kinetic aspects of IPAP and to determine whether it was a suitable tracer for brain imaging. A 10 mg/Kg dose of IPAP (or IPP) was given intravenously to the normal rats. Following sacrifice, plasma, brain and urine were collected, extracted and analyzed by HPLC. SASNLIN was used to analyze the data.

Hariharan, S.

1987-01-01

108

The design and synthesis of novel, potent and orally bioavailable N-aryl piperazine-1-carboxamide CCR2 antagonists with very high hERG selectivity.  

PubMed

A novel N-aryl piperazine-1-carboxamide series of human CCR2 chemokine receptor antagonists was discovered. Early analogues were potent at CCR2 but also inhibited the hERG cardiac ion channel. Structural modifications which decreased lipophilicity and basicity resulted in the identification of a sub-series with an improved margin over hERG. The pharmacological and pharmacokinetic properties of the lead compound from this series, N-(3,4-dichlorophenyl)-4-[(2R)-4-isopropylpiperazine-2-carbonyl]piperazine-1-carboxamide, are described. PMID:22608963

Cumming, John G; Bower, Justin F; Waterson, David; Faull, Alan; Poyser, Philip J; Turner, Paul; McDermott, Benjamin; Campbell, Andrew D; Hudson, Julian; James, Michael; Winter, Jon; Wood, Christine

2012-05-02

109

Acceleration of the reaction of carbon dioxide into aqueous 2-amino-2-hydroxymethyl-1,3-propanediol solutions by piperazine addition  

Microsoft Academic Search

In this work, the kinetics of the reaction between CO2 and piperazine-activated aqueous solutions of a sterically hindered alkanolamine, 2-amino-2-hydroxymethyl-1,3-propanediol (AHPD) was studied in a wetted wall column contactor at 303.15, 313.15 and 323.15K. The AHPD concentration in the aqueous solutions was kept at 1kmolm-3 while the piperazine (PZ) concentration varied in the range 0.1–0.4kmolm-3. Under pseudo-first-order CO2 absorption conditions,

Francis Bougie; Julien Lauzon-Gauthier; Maria C. Iliuta

2009-01-01

110

Design, synthesis, and structure-activity relationship study of bicyclic piperazine analogs of indole-3-carboxamides as novel cannabinoid CB1 receptor agonists.  

PubMed

Bicyclic piperazine derivatives were synthesized as conformationally constrained analogs of N-alkyl piperazines and were found to be potent CB1 receptor agonists. The CB1 receptor agonist activity was dependent upon the absolute configuration of the chiral center of the bicyclic ring system. Although the conformational constraint did not protect the compounds from metabolism by N-dealkylation, several bicyclic analogs were found to be more potent than the unconstrained lead compound. Compound 8b demonstrated potent antinociceptive activity in vivo. PMID:21074434

Moir, Elizabeth M; Yoshiizumi, Kazuya; Cairns, Jim; Cowley, Phillip; Ferguson, Morag; Jeremiah, Fiona; Kiyoi, Takao; Morphy, Richard; Tierney, Jason; Wishart, Grant; York, Mark; Baker, James; Cottney, Jean E; Houghton, Andrea K; McPhail, Petula; Osprey, Andrew; Walker, Glenn; Adam, Julia M

2010-10-20

111

Synthesis, structure and analysis of intermolecular interactions of organic–inorganic hybrid compound based on Anderson-type polyoxometalates and piperazine  

Microsoft Academic Search

A new organic–inorganic hybrid compound based on Anderson-B polyoxomolybdates, (H2Pz)5[Al(OH)6Mo6O18]2(SO4)2·16H2O (1) (Pz=piperazine) was synthesized and characterized by elemental analysis, IR, and single-crystal X-ray diffraction. The anions in 1 are stacked into a layer in [200] plane by hydrogen bonds of water molecules and van der Waas force, and between the layers are the sulfate ions and piperazine ions. The hydroxyl

Xiao-Dan Yang; Ya-Guang Chen; Masoud Mirzaei; Ali R. Salimi; Feng Yao

2009-01-01

112

THERMOPHYSICAL PROPERTIES OF ASSOCIATING FLUIDS IN NATURAL GAS INDUSTRY USING PC-SAFT EQUATION OF STATE  

Microsoft Academic Search

The perturbed-chain statistical associating fluid theory (PC-SAFT) is employed to calculate the thermophysical properties of some associating fluids that are widely used in the natural gas industry. Methanol, alkanolamines, and glycols are considered in this work. The alkanolamines include monoethanolamine (MEA), diethanolamine (DEA), and methyldiethanolamine (MDEA). Two new modified associating schemes are introduced to describe the alkanolamine associating behavior. The

Amir H. Tafazzol; Khashayar Nasrifar

2011-01-01

113

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

NASA Astrophysics Data System (ADS)

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, 1H 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.

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

2011-10-01

114

Microwave assisted synthesis and determination of in-vitro antimicrobial efficacy of well characterized s-triazinyl piperazines and piperidines.  

PubMed

An easy and convenient microwave-assisted synthesis of a library of s-triazinyl piperazines and piperidines, which, in addition to 4-aminobenzonitrile contain 8-hydroxyquinoline is described. The newly synthesized analogues were then subjected to determine their efficacy against some human pathogenic bacterial and fungal strains as 3 Gram negative bacteria (K. pneumoniae, S. typhi, P. vulgaris), 1 Gram positive bacteria (B. cereus) and 2 fungal species (A. clavatus, A. fumigatus) with an intent to develop novel class of antimicrobial agents. Microwave irradiation method was adopted for the final nucleophilic reactions, facilitates the condensation of piperazine and piperidine substituents to the s-triazine core. The results of bioassay showed that some of the newly synthesized s-triazines emerged as lead molecules with excellent MIC (mg/mL) values against the full array of bacterial and fungal pathogens comparable to the commercial antibiotics. The structure of final scaffolds has been affirmed on the basis of IR, 1H NMR, 13C NMR, 19F NMR and elemental analyses. PMID:22594256

Patel, Rahul V; Kumari, Premlata; Chikhalia, Kishor H

115

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

2011-06-22

116

Design, synthesis and pharmacological evaluation of 4-(piperazin-1-yl methyl)-N?-arylsulfonyl indole derivatives as 5-HT? receptor ligands.  

PubMed

4-(Piperazin-1-yl methyl)-N(1)-arylsulfonyl indole derivatives were designed and synthesized as 5-HT(6) receptor (5-HT(6)R) ligands. The lead compound 6a, from this series shows potent in vitro binding affinity, good PK profile, no CYP liabilities and activity in animal models of cognition. PMID:23141912

Nirogi, Ramakrishna V S; Badange, Rajeshkumar; Kambhampati, Ramasastri; Chindhe, Anil; Deshpande, Amol D; Tiriveedhi, Vinaykumar; Kandikere, Vishwottam; Muddana, Nageswararao; Abraham, Renny; Khagga, Mukkanti

2012-10-17

117

Enhanced mechanical properties of linear segmented shape memory poly(urethane-urea) by incorporating flexible PEG400 and rigid piperazine  

NASA Astrophysics Data System (ADS)

The goal of this study is to design and synthesize a linear segmented shape memory poly(urethane-urea) (SMPUU) that possesses near-body-temperature shape memory temperature ( T tran) and enhanced mechanical properties by incorporating flexible poly(ethylene glycol) 400 (PEG400) to form poly(D,L-lactic acid)-based macrodiols (PDLLA-PEG400-PDLLA) and then rigid piperazine (PPZ) as a chain extender to form the desired SMPUUs (PEG400-PUU-PPZ). PEG400 increased M n while maintaining a lower T g of PDLLA-PEG400-PDLLA, which together with PPZ improved the mechanical properties of PEG400-PUU-PPZ. The obtained optimum SMPUU with enhanced mechanical properties ( ? y = 24.28 MPa; ? f = 698%; U f = 181.5 MJ/m3) and a T g of 40.62°C exhibited sound shape memory properties as well, suggesting a promising SMPUU for in vivo biomedical applications.

Zhang, Xiao-Yan; Ma, Yu-Fei; Li, Yong-Gang; Wang, Pin-Pin; Wang, Yuan-Liang; Luo, Yan-Feng

2012-12-01

118

Chemiluminescence detection of piperazine designer drugs and related compounds using tris(2,2'-bipyridine)ruthenium(III).  

PubMed

We present an exploration of the chemiluminescence from reactions of benzylpiperazines and phenylpiperazines with tris(2,2'-bipyridine)ruthenium(III). The selectivity of the reagent towards these compounds was found to be highly dependent upon the pH of the solution, and the relative emission intensity was strongly influenced by electron donating or withdrawing substituents on the phenyl or benzyl ring. In spite of previous investigations showing poor responses for aromatic-substituted amines (compared to their aliphatic amine counterparts), intense emissions were observed with phenylpiperazines under acidic conditions, particularly those with halogen or trifluoromethyl substituents on the aromatic ring. Buffered alkaline conditions provided much broader selectivity for the detection of both phenylpiperazine and benzylpiperazine compounds, which we have applied to a rapid HPLC procedure for the determination of piperazines of forensic interest in 'party pill' samples. PMID:24148517

Waite, Rebecca J; Barbante, Gregory J; Barnett, Neil W; Zammit, Elizabeth M; Francis, Paul S

2013-08-23

119

Does a reinforced kinetic macrocyclic effect exist? the demetallation in strong acid of copper(II) Complexes with open and cyclic tetramines containing a piperazine fragment.  

PubMed

The demetallation in acidic solution of the Cu(II) complexes with open-chain and cyclic tetramines containing a piperazine unit (2 and 3) has been investigated in terms of its kinetic aspects and compared with the behaviour of unsubstituted counterparts (tetramines 1 and 4). The presence of the piperazine fragment slows demetallation of the open-chain-ligand complex owing to the activation barrier associated with the conformational change from boat-to-half-boat; however, it does not affect the demetallation of the macrocyclic complex, which involves the spontaneous boat-to-twist conformational change. Thus, lateral reinforcement of a cyclam-like ligand does not add any further contribution to the typical inertness in demetallation of macrocyclic complexes. PMID:15224329

Boiocchi, Massimo; Bonizzoni, Marco; Fabbrizzi, Luigi; Foti, Francesco; Licchelli, Maurizio; Poggi, Antonio; Taglietti, Angelo; Zema, Michele

2004-07-01

120

The influence of the boat-to-chair conversion on the demetallation of the nickel(II) complex of an open-chain tetramine containing a piperazine fragment.  

PubMed

The nickel(II) complex with an open chain tetramine containing a piperazine fragment (1) displays an unusual resistance to demetallation in acidic solution and exhibits a lifetime of about five minutes in a solution 0.1 M in HClO4 and 7.0 M in NaClO4. Sluggishness with respect to the demetallation is ascribed to the occurrence of the boat-to-chair conformational conversion of the piperazine fragment, which implies the passage through the highly energetic half-boat transition state. The use of a high concentration of the inert electrolyte induces a 'salting out' effect on both thermodynamics (stability of metal complexes is enhanced) and kinetics (resistance to demetallation is increased). PMID:15252530

Boiocchi, Massimo; Bonizzoni, Marco; Fabbrizzi, Luigi; Foti, Francesco; Licchelli, Maurizio; Taglietti, Angelo; Zema, Michele

2004-01-21

121

3-[4-(10H-Indolo[3,2-b]quinolin-11-yl)piperazin-1-yl]propan-1-ol  

PubMed Central

In the title compound, C22H24N4O, the aromatic moiety is essentially planar (r.m.s. deviation of a least-squares plane fitted through all non-H atoms = 0.0386?Å) and is rotated by 89.98?(4)° from the piperazine ring, which adopts the expected chair conformation. The propanol chain is not fully extended away from the piperazine ring. In the crystal, there are two unique hydrogen-bonding inter­actions. One is an O—H?N inter­action which, together with an inversion-related symmetry equivalent, forms a ring motif. The second is an N—H?N inter­action which links adjacent mol­ecules by means of a chain motif which propagates in the c-axis direction. Overall, a two-dimensional hydrogen-bonded structure is formed.

Nichol, Gary S.; Boddupally, Peda V. L.; De, Biswanath; Hurley, Laurence H.

2011-01-01

122

1,4-Bis{[hydroxy(phenyl)phosphoryl]methyl}piperazine-1,4-diium tetrachloridocadmate(II) dihydrate and the cobaltate(II) analogue.  

PubMed

The reaction of aminophosphinic acid with CdCl2·2.5H2O or CoCl2·6H2O in concentrated hydrochloric acid yielded the isostructural compounds 1,4-bis{[hydroxy(phenyl)phosphoryl]methyl}piperazine-1,4-diium tetrachloridocadmate(II) dihydrate, (C18H26N2O4P2)[CdCl4]·2H2O, (I), and 1,4-bis{[hydroxy(phenyl)phosphoryl]methyl}piperazine-1,4-diium tetrachloridocobaltate(II) dihydrate, (C18H26N2O4P2)[CoCl4]·2H2O, (II). The asymmetric unit of each contains two half dications, both located on crystallographic centres of inversion, a tetrachloridometallate(II) dianion and two solvent water molecules. The residues are linked into two-dimensional layers in the ab plane by O-H···O hydrogen bonds. PMID:23832033

Du, Chao-Jun; Wang, Li-Sheng

2013-06-21

123

Design, synthesis, and SAR of N-((1-(4-(propylsulfonyl)piperazin-1-yl)cycloalkyl)methyl)benzamide inhibitors of glycine transporter-1.  

PubMed

The design, synthesis, and structure-activity relationships (SAR) of a series of N-((1-(4-(propylsulfonyl)piperazin-1-yl)cycloalkyl)methyl)benzamide inhibitors of glycine transporter-1 (GlyT-1) are described. Optimization of the benzamide and central ring components of the core scaffold led to the identification of a GlyT-1 inhibitor that demonstrated in vivo activity in a rodent cerebral spinal fluid (CSF) glycine model. PMID:23380375

Cioffi, Christopher L; Wolf, Mark A; Guzzo, Peter R; Sadalapure, Kashinath; Parthasarathy, Visweswaran; Dethe, Dattatraya; Maeng, Jun-Ho; Carulli, Edmund; Loong, David T J; Fang, Xiao; Hu, Min; Gupta, Priya; Chung, Mark; Bai, Mei; Moore, Nick; Luche, Michele; Khmelnitsky, Yuri; Love, Patrick L; Watson, Megan A; Mhyre, Andrew J; Liu, Shuang

2013-01-11

124

Kinetics of hydrogen peroxide decomposition in the presence of binuclear complexes of cobalt(II) with 1,4-piperazine-bis(carbothiosulfene diethylamide)  

Microsoft Academic Search

We have obtained complexes of Co(II) with 1,4-piperazine-bis(carbothiosulfene diethylamide) (L) of composition [Co2LX4] (X?=?Cl, Br, I, NCS). We discuss the characteristic features of the decomposition kinetics for H2O2 in the presence of these complexes and the effect of the acido ligands X on their catalytic activity. We have observed isokinetic\\u000a relationships between the activation parameters and the reaction rate constants.

D. G. Chikhichin; V. A. Kotseruba; O. A. Levchenko; G. N. Khitrich; I. I. Seifullina; G. L. Kamalov

125

Buffers for the Physiological pH Range: Thermodynamics of the Second Dissociation of N -(2-Hydroxyethyl)piperazine- N? -2-hydroxypropanesulfonic Acid From 5 to 55°C  

Microsoft Academic Search

The second acidic dissociation constants pK2 of the ampholyte N-(2-hydroxyethyl) piperazine-N'-2-hydroxypropanesulfonic acid (HEPPSO) have been determined at seven temperatures from 5 to 55°C from emf measurements utilizing hydrogen and silver–silver chloride cells without liquid junction. The thermodynamic quantities, ?G°, ?H°,?S°, and ? Cpo have been calculated from the temperature coefficient of pK2. At 25°C, the pK2 = 8.042 and at

Rabindra N. Roy; Jill Cramer; Victoria Randon; Demara Willard; Jennifer L. Walter; William S. Good; Amanda Kilker; Lakshmi N. Roy

1998-01-01

126

Effects of repeated administration of the monoamine oxidase inhibitor phenelzine on the discriminability of d-lysergic acid diethylamide (LSD) and 1-(m-trifluoromethylphenyl) piperazine (TFMPP)  

Microsoft Academic Search

Rats trained to discriminate d-lysergic acid diethylamide (LSD; 0.08 mg\\/kg) or 1-(m-trifluoromethylphenyl) piperazine (TFMPP; 0.8 mg\\/kg) were treated with the monoamine oxidase inhibitor (MAOI) phenelzine (10 mg\\/kg\\/day) for 7 days. After a 24 h “washout” period, they were challenged with the training drug (and dose) or saline, during extinction test sessions. Following 0.08 mg\\/kg LSD, LSD-trained rats responded primarily on

Kathryn A. Cunningham; Brenda A. Carroll; James B. Appel

1986-01-01

127

An unknown solvate of 1-(2,4-di-chloro-benz-yl)-4-[(4-methyl-phen-yl)sulfon-yl]piperazine  

PubMed Central

In the title compound, C18H20Cl2N2O2S, the piperazine ring adopts a chair conformation. The dihedral angle between the sulfonyl-bound benzene ring and the best-fit plane through the six non-H atoms of the piperazine ring is 72.22?(12)°; those between the di­chloro­benzene ring and the sulfonyl and piperazine rings are 2.44?(13) and 74.16?(2)°, respectively. In the crystal, mol­ecules are connected through weak C—H?O inter­actions into a hexa­meric unit generating a R 6 6(60) motif in the ab plane. The mol­ecules are also connected into C(4) chains through weak C—H?N inter­actions. The solvent used to grow the crystal was a mixture of di­chloro­methane and methanol, but the resulting electron density was uninter­pretable. The solvent contribution to the scattering was removed with the SQUEEZE routine in PLATON [Spek (2009 ?). Acta Cryst. D65, 148–155]. The formula mass and unit-cell characteristics do not take into account the disordered solvent.

Sreenivasa, S.; ManojKumar, K. E.; Anitha, H. C.; Suchetan, P. A.; Palakshamurthy, B. S.; Jayashree, Yenagi; Tonannavar, J.

2013-01-01

128

A novel piperazine derivative potently induces caspase-dependent apoptosis of cancer cells via inhibition of multiple cancer signaling pathways.  

PubMed

Despite rapid progress in anticancer drug development and improvement in clinical outcomes, the survival rate for many types of cancer is still unacceptably low. Therefore, it is crucial to discover novel anticancer drugs to both prevent and treat the disease. In recent years, the advent of combinatorial chemistry allows the design and parallel synthesis of millions of small compounds that have drug-like properties. In vitro high throughput screening of such compound libraries has allowed the identification of many new drug candidates that may be further evaluated for their efficacy and mechanism of action. The overall objective of this study was to identify small molecule compounds as candidates for anti-cancer drug development. We first used cell proliferation and cytotoxicity assays to identify compounds exhibiting anti-cancer activity in vitro in a leukemia cell line (K562). Six top compounds selected from the initial screening of a library of 2,560 compounds were further evaluated in multiple cancer cell lines to rank the drug candidates. The top candidate was further investigated to elucidate the molecular mechanism underlying its anticancer activity. Our studies suggest that this piperazine derivative effectively (GI50 = 0.06-0.16 ?M) inhibits cancer cell proliferation and induces caspase-dependent apoptosis via inhibiting multiple cancer signaling pathways including the PI3K/AKT, the Src family kinases and the BCR-ABL pathways. PMID:24093059

She, Edward X; Hao, Zhonglin

2013-09-25

129

Growth, nonlinear optical, thermal, dielectric and laser damage threshold studies of semiorganic crystal: Monohydrate piperazine hydrogen phosphate  

NASA Astrophysics Data System (ADS)

Monohydrate piperazine hydrogen phosphate (MPHP), a semi organic nonlinear optical material has been synthesized and single crystals were grown from aqueous solution by slow evaporation technique. Single crystal X-ray diffraction study on grown crystal reveals that they belong to monoclinic crystal system with space group P21/c; (a = 6.39 Å; b = 12.22 Å; c = 11.16 Å; ? = 97.14°; V = 864 Å3). The structural perfection of the grown crystal was analyzed by high-resolution X-ray diffraction (HRXRD) rocking curve measurements. FTIR spectrum confirms the presence of the functional groups in synthesized material. UV-Vis spectrum indicates that the crystal is transparent in the entire visible region with a lower cut off wavelength of 387 nm. The variation of dielectric properties of the grown crystal with respect to frequency has been investigated at different temperatures. Thermal analysis carried out on the MPHP crystal shows that the crystal is stable up to 135 °C. Relative powder second harmonic generation efficiency tested by Kurtz-Perry powder technique, which was about 0.638 times that of Potassium dihydrogen phosphate.

Krishnan, P.; Gayathri, K.; Bhagavannarayana, G.; Gunasekaran, S.; Anbalagan, G.

2013-02-01

130

A novel piperazine derivative potently induces caspase-dependent apoptosis of cancer cells via inhibition of multiple cancer signaling pathways  

PubMed Central

Despite rapid progress in anticancer drug development and improvement in clinical outcomes, the survival rate for many types of cancer is still unacceptably low. Therefore, it is crucial to discover novel anticancer drugs to both prevent and treat the disease. In recent years, the advent of combinatorial chemistry allows the design and parallel synthesis of millions of small compounds that have drug-like properties. In vitro high throughput screening of such compound libraries has allowed the identification of many new drug candidates that may be further evaluated for their efficacy and mechanism of action. The overall objective of this study was to identify small molecule compounds as candidates for anti-cancer drug development. We first used cell proliferation and cytotoxicity assays to identify compounds exhibiting anti-cancer activity in vitro in a leukemia cell line (K562). Six top compounds selected from the initial screening of a library of 2,560 compounds were further evaluated in multiple cancer cell lines to rank the drug candidates. The top candidate was further investigated to elucidate the molecular mechanism underlying its anticancer activity. Our studies suggest that this piperazine derivative effectively (GI50 = 0.06-0.16 ?M) inhibits cancer cell proliferation and induces caspase-dependent apoptosis via inhibiting multiple cancer signaling pathways including the PI3K/AKT, the Src family kinases and the BCR-ABL pathways.

She, Edward X; Hao, Zhonglin

2013-01-01

131

Determination of buspirone and 1-(2-pyrimidinyl)-piperazine (1-PP) in human plasma by capillary gas chromatography.  

PubMed

Two separate gas chromatographic methods for the determination of buspirone and its active metabolite, 1-(2-pyrimidinyl)-piperazine (1-PP) in human plasma are described. Both procedures involve solid-phase extraction (the packing material of the cartridges used was C8 for buspirone and a mixed-mode sorbent for 1-PP), injection of the sample into a gas chromatograph equipped with a fused-silica capillary column and a nitrogen-phosphorus detector, and analysis with temperature programming (from 220 degrees C to 285 degrees C for buspirone and from 138 degrees C to 285 degrees C for 1-PP). The coating material of the analytical column was 5% diphenyl dimethyl silicone for buspirone and 50% diphenyl dimethyl silicone for 1-PP. Zolpidem was used as an internal standard in the buspirone assay and 1-phenylpiperazine in the 1-PP assay. Recovery of buspirone and 1-PP averaged 98% and 89%, respectively, and the limit of quantification was 0.2 ng/mL for both compounds. The between-run coefficients of variation ranged from 3.2% to 9.4% and from 2.9% to 8.6% for samples spiked with three different concentrations of buspirone and 1-PP, respectively. The suitability of these assays for pharmacokinetic studies was shown by analyzing timed plasma samples from volunteers after ingestion of a single therapeutic dose of buspirone (10 mg). PMID:10365644

Kivistö, K T; Laitila, J; Mårtensson, K; Neuvonen, P J

1999-06-01

132

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

2005-11-02

133

The 5-substituted piperazine as a novel secondary pharmacophore greatly improving the physical properties of urea-based inhibitors of soluble epoxide hydrolase  

PubMed Central

The inhibition of the mammalian soluble epoxide hydrolase (sEH) is a promising new therapy in the treatment of hyper-tention and inflammation. The problems of limited water solubility and high melting points commonly displayed by the active 1,3-disubstituted ureas prevent the further development of potent urea-based sEH inhibitors. Therefore, a new class of potent inhibitors of sEH were designed and synthesized by the introduction of a polar constrained piperazino group in the right side of adasmantyl urea to increase the water solubility. A facile and general synthesis was established to prepare a series of 1-adamantan-1-yl-3-(2-piperazin-2-yl-ethyl)-ureas (1a–d) with various 5-substitutions on the 2-piperazino ring, which will advance the SAR study by the efficient making of structurally diverse analogs. The effect of the 5-substitution on the activity and the water solubility was examined. The best potency was exhibited by the 5-benzyl-substituted-piperazine-containing urea with an IC50 value of 1.37 ?M against human sEH and good water solubility (S = 7.46 mg/mL) and low melting point, in which the 5-substituted piperazine serves as a favorable secondary pharmacophore and a water-solubility enhancing group. Our present work provides a promising new template for the design of orally available therapeutic agents for the disorders that can be addressed by changing the in vivo concentration of the chemical mediators that contain an epoxide.

Li, Hui-Yuan; Jin, Yi; Morisseau, Christophe; Hammock, Bruce D.; Long, Ya-Qiu

2007-01-01

134

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

2013-08-21

135

Highly Active Anti-Pneumocystis carinii Compounds in a Library of Novel Piperazine-Linked Bisbenzamidines and Related Compounds  

PubMed Central

Trimethoprim-sulfamethoxazole and pentamidine isethionate have been used extensively for the prophylaxis and therapy of pneumonia caused by Pneumocystis jirovecii. Problems associated with toxicity and potential emerging resistance for both therapies necessitate the development of safe and effective analogs or new treatment strategies. In the present study, a library of 36 compounds was synthesized by using the pentamidine molecule as the parent compound modified by a 1,4-piperazinediyl moiety as the central linker to restrict conformation flexibility. The compounds were evaluated for anti-Pneumocystis carinii activity in a bioluminescent ATP-driven assay. Four of the compounds were highly active, with 50% inhibitory concentration (IC50) values of <0.01 ?g/ml; four had very marked activity (IC50 < 0.10 ?g/ml); ten had marked activity (IC50 < 1.0 ?g/ml); nine had moderate activity (IC50 < 10 ?g/ml); one had slight activity (IC50 = 34.1 ?g/ml); and the remaining eight did not demonstrate activity in this assay system. The high level of activity was specifically associated with an alkyl chain length of five to six carbons attached to one of the nitrogens of the bisamidinium groups. None of the highly active compounds and only one of the very marked compounds exhibited any toxicity when evaluated in three mammalian cell lines. The strategy of substitution of 1,4-piperazine-linked bisbenzamidines produced compounds with the highest level of activity observed in the ATP assay and holds great promise for the development of efficacious anti-P. carinii therapy.

Cushion, Melanie T.; Walzer, Peter D.; Collins, Margaret S.; Rebholz, Sandra; Vanden Eynde, Jean Jacques; Mayence, Annie; Huang, Tien L.

2004-01-01

136

Synthesis, characterization, and photochromic properties of hybrid organic-inorganic materials based on molybdate, DABCO, and piperazine.  

PubMed

Prompted by our interest in new photochromic organic-inorganic hybrid materials, the reactivity of [Mo7O24]6- toward a structure-directing reagent diamine such as 1,4-diazabicyclo[2.2.2]octane (DABCO) and piperazine (pipz) has been investigated, and three new molybdenum(VI)-containing compounds, namely, (H2DABCO)3[Mo7O24].4H2O (1), (H2DABCO)[Mo3O10].H2O (2), and (H2DABCO)2(NH4)2[Mo8O27].4H2O (3), have been synthesized and characterized. New synthetic routes to achieve the known compounds (H2DABCO)2(H2pipz)[Mo8O27] (4), (H2pipz)3[Mo8O27] (5), and (H2DABCO)2[Mo8O26].4H2O (6) are also reported. All of these compounds contain different poly(oxomolybdate) clusters, i.e., discrete [Mo7O24]6- blocks in 1, infinite polymeric chains 1/infinity[Mo3O10]2- in 2, 1/infinity[Mo8O27]6- in 3-5, and 1/infinity[Mo8O26]4- in 6, associated in a tridimensional assembly by hydrogen bonds with H2DABCO2+ and/or H2pipz2+ cations. Interconversion pathways and chemical factors affecting the stabilization of the different species are highlighted and discussed. At the opposite of 6, compounds 1-5 show photochromic behavior under UV excitation. Namely, compounds 1-5 shift from white or pale yellow to pale pink, reddish brown, or purple under UV illumination depending on the chemical nature of the mineral framework, with the kinetics of the color change being dictated by the nature of the organic component and by the organic-inorganic interface. PMID:17323943

Coué, Violaine; Dessapt, Rémi; Bujoli-Doeuff, Martine; Evain, Michel; Jobic, Stéphane

2007-02-27

137

N-Phenylpropyl-N?-(3-methoxyphenethyl)piperazine (YZ-185) Attenuates the Conditioned-Rewarding Properties of Cocaine in Mice  

PubMed Central

Sigma receptor antagonists diminish the effects of cocaine in behavioral assays, including conditioned place preference. Previous locomotor activity experiments in mice determined that the sigma receptor ligand YZ-185 (N-phenylpropyl-N?-(3-methoxyphenethyl)piperazine) enhanced cocaine-induced hyperactivity at a lower (0.1??mol/kg) dose and dose-dependently attenuated cocaine-induced hyperactivity at higher (3.16–31.6??mol/kg) doses. The present study investigated the effect of YZ-185 on cocaine's conditioned-rewarding properties in mice. YZ-185 (0.1, 0.316, 3.16, and 31.6??mol/kg) did not have intrinsic activity to produce conditioned place preference or aversion. A higher (31.6??mol/kg) YZ-185 dose, but not lower (0.1–3.16??mol/kg) YZ-185 doses, prevented the development of place preference to cocaine (66??mol/kg). YZ-185 did not alter the expression of cocaine place preference. To further characterize YZ-185's behavioral profile, its effects in the elevated zero maze and rotarod procedures were also determined; YZ-185 produced no significant change from baseline in either assay, indicating that the sigma receptors probed by YZ-185 do not regulate anxiety-like or coordinated motor skill behaviors. Overall, these results suggest that YZ-185 is a sigma receptor antagonist at the 31.6??mol/kg dose and demonstrate that sigma receptors can mediate the development of the conditioned-rewarding properties of cocaine.

Sage, Andrew S.; Vannest, Scott C.; Fan, Kuo-Hsien; Will, Matthew J.; Lever, Susan Z.; Lever, John R.; Miller, Dennis K.

2013-01-01

138

Pharmacokinetics of 14C-N-N'-dicyclopropyl-methyl-piperazine-dichlorhydrate. 3rd communication: whole-body autoradiographic study in Cynomolgus monkeys after oral administration.  

PubMed

A distribution study was carried out on Cynomolgus monkeys (Macaca fascicularis) dosed orally with 14C-labelled N-N'-dicyclopropyl-methyl-piperazine-dichlor-hydrate 14C-Ino 2628-CZ and sacrificed 2, 8 and 24 h after dosage, using whole-body autoradiography. It is demonstrated that radioactivity is found in all the body; high intakes occur in melanin containing tissues, in blood-forming organs, and in accessory genital glands. Moreover, radioactivity crosses the blood-brain barrier and is mainly localized in hippocampus, caudate, putamen and frontal cortex. PMID:8328994

Benard, P; Dormard, Y; Houin, G; Declume, C; Malbosc, R; Tufenkji, A E; Galtier, P; Alvinerie, M

1993-05-01

139

Synthesis, 5HT 1A and 5HT 2A receptor affinity and QSAR study of 1-benzhydryl-piperazine derivatives with xanthine moiety at N4  

Microsoft Academic Search

\\u000a Abstract  Three novel 1-benzhydryl-piperazines with xanthine moiety at N4 were synthesized and tested for 5-HT1A and 5-HT2A receptor affinity. One of the compounds showed the highest affinity (58.6 nM) and selectivity (34 times) to 5-HT2A receptor known for this class of compounds. A set of the three new and 31 previously synthesized 1-arylpiperazines with xanthine\\u000a moiety at N4 was compiled and a

Iva Valkova; Alexander Zlatkov; Krystyna N?dza; Irini Doytchinova

140

1-(m-Chlorophenyl)piperazine (mCPP) Dissociates In Vivo Serotonin Release from Long-Term Serotonin Depletion in Rat Brain  

Microsoft Academic Search

Serotonin (5-HT) releasing agents such as d-fenfluramine are known to cause long-term depletion of forebrain 5-HT in animals, but the mechanism of this effect is unknown. In the present study, we examined the relationship between drug-induced 5-HT release and long-term 5-HT depletion in rat brain. The 5-HT-releasing actions of d-fenfluramine and a non-amphetamine 5-HT drug, 1-(m-chlorophenyl)piperazine (mCPP), were compared using

Michael H Baumann; Mario A Ayestas; Christina M Dersch; Richard B Rothman

2001-01-01

141

SAR studies on a series of N-benzyl-4-heteroaryl-1-(phenylsulfonyl)piperazine-2-carboxamides: potent inhibitors of the polymerase enzyme (NS5B) of the hepatitis C virus.  

PubMed

Described herein is the initial optimization of (+/-) N-benzyl-4-heteroaryl-1-(phenylsulfonyl)piperazine-2-carboxamide (1), a hit discovered in a high throughput screen run against the NS5B polymerase enzyme of the hepatitis C virus. This effort resulted in the identification of (S)-N-sec-butyl-6-((R)-3-(4-(trifluoromethoxy)benzylcarbamoyl)-4-(4-(trifluoromethoxy)phenylsulfonyl)piperazin-1-yl)pyridazine-3-carboxamide (2), that displayed potent replicon activities against HCV genotypes 1b and 1a (EC(50) 1b/1a=7/89 nM). PMID:21450465

Gentles, Robert G; Ding, Min; Zheng, Xiaofan; Chupak, Louis; Poss, Michael A; Beno, Brett R; Pelosi, Lenore; Liu, Mengping; Lemm, Julie; Wang, Ying-Kai; Roberts, Susan; Gao, Min; Kadow, John

2011-03-06

142

Investigations on the 1-(2-biphenyl)piperazine motif: identification of new potent and selective ligands for the serotonin(7) (5-HT(7)) receptor with agonist or antagonist action in vitro or ex vivo.  

PubMed

Here we report the design, synthesis, and 5-HT(7) receptor affinity of a set of 1-(3-biphenyl)- and 1-(2-biphenyl)piperazines. The effect on 5-HT(7) affinity of various substituents on the second (distal) phenyl ring was analyzed. Several compounds showed 5-HT(7) affinities in the nanomolar range and >100-fold selectivity over 5-HT(1A) and adrenergic ?(1) receptors. 1-[2-(4-Methoxyphenyl)phenyl]piperazine (9a) showed 5-HT(7) agonist properties in a guinea pig ileum assay but blocked 5-HT-mediated cAMP accumulation in 5-HT(7)-expressing HeLa cells. PMID:22738316

Lacivita, Enza; Patarnello, Daniela; Stroth, Nikolas; Caroli, Antonia; Niso, Mauro; Contino, Marialessandra; De Giorgio, Paola; Di Pilato, Pantaleo; Colabufo, Nicola A; Berardi, Francesco; Perrone, Roberto; Svenningsson, Per; Hedlund, Peter B; Leopoldo, Marcello

2012-07-11

143

3-(Adamantan-1-yl)-4-phenyl-1-[(4-phenyl-piperazin-1-yl)meth-yl]-1H-1,2,4-triazole-5(4H)-thione  

PubMed Central

The title mol­ecule, C29H35N5S, displays a chair-shaped piperazine ring, as well as an approximately planar triazole ring (r.m.s. deviation = 0.001?Å) whose phenyl substituent is nearly perpendicular to the mean plane of the five-membered ring [dihedral angle = 88.9?(1)°]. The substituents on the piperazine ring occupy equatorial sites. In the crystal, the adamantyl cage is disordered over two sets of sites with a major component of 67.8?(5)%. Weak inter­molecular C—H?S hydrogen bonding is present in the crystal.

Al-Abdullah, Ebtehal S.; Asiri, Hanadi H.; El-Emam, Ali; Ng, Seik Weng

2012-01-01

144

Modelling of serotonin reuptake inhibitory and histamine H?antagonistic activity of piperazine and diazepane amides: QSAR rationales for co-optimization of the activity profiles.  

PubMed

Selective human serotonin reuptake transporter (hSERT) inhibition is the first line of treatment to deal with the depression. In clinical practice for managing depression, the stimulants are co-prescribed to overcome cognitive impairment and fatigue. Recently, histamine H(3) antagonists with serotonin reuptake inhibition activity have been proposed as alternative approach for the treatment of depression. In this context, a QSAR study of hSERT inhibitory and H(3) antagonistic activity of piperazine and diazepane amide derivatives has been carried out using the combinatorial protocol in multiple linear regression (CP-MLR) with 0D- to 2D-Dragon descriptors. The derived QSAR models have provided a rational approach for the development of new piperazine and diazepane amide derivatives as hSERT inhibitors and H(3) antagonists. In a concomitant partial least-squares (PLS) analysis of the hSERT and histamine H(3) activities, the fraction contributions of identified descriptors revealed their importance in modulating these activities. The PLS analysis of other biological endpoints, namely hNET, hDAT, and histamine H(3) activity in functional assay (H(3)pA(2)) of these analogues with the identified descriptors has further highlighted their scope in modulating these activities. PMID:21598199

Sharma, B K; Singh, P; Shekhawat, M; Sarbhai, K; Prabhakar, Y S

2011-06-01

145

1-{2-[4-(4-Nitro-phen-yl)piperazin-1-yl]eth-yl}-4-aza-1-azoniabicyclo-[2.2.2]octane iodide.  

PubMed

The title compound, C(18)H(28)N(5)O(2) (+)·I(-), was observed as a main product in an intended 1:1 reaction between 4-iodo-nitro-benzene and 1,4-diaza-bicyclo-[2.2.2]octane (DABCO). In the reaction, DABCO undergoes a ring opening to yield a quaternary salt of DABCO and 1-ethyl-4-(4-nitro-phen-yl)piperazine with an iodide anion. The crystal structure determination was carried out as no crystal structure had been previously reported in the investigations describing the corresponding reaction with 4-chloro-nitro-benze. Indeed, the crystal structure of the title compound confirms the mol-ecular composition proposed earlier for the analogous chloride salt. The cation conformation is similar to the previously reported dinitro analogue 1-{2-[4-(2,4-dinitro-phen-yl)piperazin-1-yl]eth-yl}-4-aza-1-azoniabicyclo-[2.2.2]octane chloride [Clegg et al. (2004 ?). Acta Cryst. E60, o291-o293]. The crystal packing is dominated by cation?I(-) inter-actions in addition to weak inter-molecular C-H?O(2)N and C-H?N inter-actions between the cations. PMID:22807819

Peuronen, Anssi; Lahtinen, Manu

2012-06-02

146

Schild analyses reveal that the cerebral cortical serotonin 5HT/sub 2/ site is linked to phosphoinositide (PI) hydrolysis: relative efficacies of piperazines  

SciTech Connect

Cerebral cortical slices were prelabelled with /sup 3/H-inositol and serotonin (5HT) stimulated release of /sup 3/H-inositol-1-phosphate was measured as an index of PI hydrolysis. Antagonist Kd values at the PI linked receptor were determined by Schild analyses. A highly significant positive correlation (r = 0.99) was found between these Kd values and Ki values at the 5HT/sub 2/ binding site labelled with /sup 3/H-ketanserin, suggesting that the PI linked receptor and the 5HT/sub 2/ site are identical. The 5HT/sub 2/ mediated PI response was used to determine relative efficacies of piperazine derivatives. Both quipazine and 6-chloro-2(1-piperzinyl)-pyrazine (MK-212) stimulated PI hydrolysis in a ketanserin sensitive manner but with maximal responses which were lower than that of 5HT. m-Trifluoro-methylphenylpiperazine (TFMPP), m-chlorophenylpiperazine (MCPP) and 1-(1-naphthyl) piperazine (1-NP) did not stimulate PI hydrolysis, but blocked the effect of 5HT. These data suggest that the 5HT/sub 2/ site is a functional receptor which is linked to PI hydrolysis and that quipazine and MK-212 are partial 5HT/sub 2/ agonists while 1-NP, MCPP and TFMPP are pure 5HT/sub 2/ antagonists.

Conn, P.J.; Sanders-Bush, E.

1986-03-01

147

Measurement of nitrosamine and nitramine formation from NOx reactions with amines during amine-based carbon dioxide capture for postcombustion carbon sequestration.  

PubMed

With years of full-scale experience for precombustion CO(2) capture, amine-based technologies are emerging as the prime contender for postcombustion CO(2) capture. However, concerns for postcombustion applications have focused on the possible contamination of air or drinking water supplies downwind by potentially carcinogenic N-nitrosamines and N-nitramines released following their formation by NO(x) reactions with amines within the capture unit. Analytical methods for N-nitrosamines in drinking waters were adapted to measure specific N-nitrosamines and N-nitramines and total N-nitrosamines in solvent and washwater samples. The high levels of amines, aldehydes, and nitrite in these samples presented a risk for the artifactual formation of N-nitrosamines during sample storage or analysis. Application of a 30-fold molar excess of sulfamic acid to nitrite at pH 2 destroyed nitrite with no significant risk of artifactual nitrosation of amines. Analysis of aqueous morpholine solutions purged with different gas-phase NO and NO(2) concentrations indicated that N-nitrosamine formation generally exceeds N-nitramine formation. The total N-nitrosamine formation rate was at least an order of magnitude higher for the secondary amine piperazine (PZ) than for the primary amines 2-amino-2-methyl-1-propanol (AMP) and monoethanolamine (MEA) and the tertiary amine methyldiethanolamine (MDEA). Analysis of pilot washwater samples indicated a 59 ?M total N-nitrosamine concentration for a system operated with a 25% AMP/15% PZ solvent, but only 0.73 ?M for a 35% MEA solvent. Unfortunately, a greater fraction of the total N-nitrosamine signal was uncharacterized for the MEA-associated washwater. At a 0.73 ?M total N-nitrosamine concentration, a ~25000-fold reduction in concentration is needed between washwater units and downwind drinking water supplies to meet proposed permit limits. PMID:22831707

Dai, Ning; Shah, Amisha D; Hu, Lanhua; Plewa, Michael J; McKague, Bruce; Mitch, William A

2012-08-16

148

Multicriterial analysis of post-combustion carbon dioxide capture using alkanolamines  

Microsoft Academic Search

The most promising technology for carbon dioxide capture from coal and natural gas fired power plants at large scale applications is based on post-combustion method using gas–liquid absorption. The paper evaluates carbon dioxide absorption, at low partial pressures, from flue gases by post-combustion capture using aqueous solutions of various alkanolamines: monoethanolamine (MEA), diethanolamine (DEA), methyldiethanolamine (MDEA), 2-amino-2methyl-1-propanol (AMP) and their

Anamaria Padurean; Calin-Cristian Cormos; Ana-Maria Cormos; Paul-Serban Agachi

2011-01-01

149

Performance characteristics and modeling of carbon dioxide absorption by amines in a packed column  

Microsoft Academic Search

Absorption of carbon dioxide by amines in a packed column was experimentally investigated. The amines employed in the present study were the primary mono-ethanolamine (MEA) and tertiary N-methyldiethanolamine (MDEA), two very popular amines widely used in the industries for gas purification. The CO2 absorption characteristics by these two amines were experimentally examined under various operating conditions. A theoretical model was

Sheng H Lin; Ching T Shyu

1999-01-01

150

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

151

2-{[2-(Piperazin-4-ium-1-yl)ethyl-iminio]meth-yl}phenolate 0.06-chloride 0.94-perchlorate  

PubMed Central

The structure of the title salt, C13H20N3O+·0.94ClO4 ?·0.06Cl?, contains a zwitterionic Schiff base with a net positive charge and a perchlorate anion having substitutional disorder with Cl. In the cation, the azomethine N atom is protonated and donates hydrogen bonds to the phenolate O atom and to the tertiary N atom of the piperazine ring. In the crystal, two Schiff base mol­ecules are linked about a center of inversion by a pair of N—H?O hydrogen bonds. The resulting dimers are N—H?O and C—H?O hydrogen bonded to the perchlorate anions, forming a three-dimensional structure. The network is further consolidated by C—H?? inter­actions.

Reisi, Mohammad Reza; Khaledi, Hamid; Mohd Ali, Hapipah

2011-01-01

152

Discovery of N-Aryl Piperazines as Selective mGlu(5) Potentiators with Efficacy in a Rodent Model Predictive of Anti-Psychotic Activity.  

PubMed

This Letter describes the discovery, SAR and in vitro and in vivo pharmacological profile of a novel non-MPEP derived mGlu(5) positive allosteric modulator (PAM) based upon an N-aryl piperazine chemotype. This mGlu(5) chemotype exhibits the ability to act as either a non-competitive antagonist/negative allosteric modulator (NAM) or potentiator of the glutamate response depending on the identity of the amide substituent, i.e., a 'molecular switch'. A rapidly optimized PAM, 10e (VU0364289), was shown to be potent and specific for the rat mGlu(5) receptor and subsequently demonstrated to be efficacious in a clinically relevant rodent model predictive of anti-psychotic activity, thus providing the first example of a centrally active mGluR(5) PAM optimized from an HTS-derived mGluR5 competitive antagonist. PMID:23308336

Zhou, Ya; Manka, Jason T; Rodriguez, Alice L; Weaver, C David; Days, Emily L; Vinson, Paige N; Jadhav, Satyawan; Hermann, Elizabeth J; Jones, Carrie K; Conn, P Jeffrey; Lindsley, Craig W; Stauffer, Shaun R

2010-08-13

153

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

2013-09-21

154

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

2013-08-20

155

2-Methyl-4-(4-methyl-piperazin-1-yl)-10H-thieno[2,3-b][1,5]benzodiazepine (olanzapine) propan-2-ol disolvate.  

PubMed

In the title solvate, C17H20N4S·2C3H8O, pairs of olanzapine mol-ecules related by a centre of inversion stack along the a axis, forming columns, which are packed parallel to each other along the b axis, forming a sheet arrangement. The columns within these sheets are hydrogen bonded to each other through the propan-2-ol solvent mol-ecules. The diazepine ring of the olanzapine exists in a puckered conformation with the thiophene and phenyl rings making a dihedral angle of 57.66?(7)° and the piperazine ring adopts a chair conformation with the methyl group in an equatorial position. PMID:23723900

Bhardwaj, Rajni M; Florence, Alastair J

2013-04-20

156

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

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].

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

2013-01-01

157

1-[(4-Chloro-phen-yl)(phen-yl)meth-yl]piperazine-1,4-diium bis-(trichloro-acetate)-trichloro-acetic acid (1/1)  

PubMed Central

In the title salt adduct, C17H21ClN2 2+·2C2Cl3O2 ?·C2HCl3O2, the Cl atom of the dication is disordered over two positions in a 0.915?(3):0.085?(3) ratio. The Cl atoms in the trichloroacetate anions and trichloroacetic acid molecule are also disordered, with refined site-occupation factors of 0.59?(3):0.41?(3), 0.503?(12):0.417?(12) and 0.653?(12):0.347?(12). The piperazine ring adopts a chair conformation, with puckering parameters Q T = 0.587?(3)?Å, ? = 2.6?(2) and ? 334?(6)°. In the crystal, neighbouring mol­ecules are linked by N—H?O, O—H?O, N—H?Cl, C—H?O and C—H?Cl hydrogen bonds, forming a three-dimensional network.

Song, Yanxi; Chidan Kumar, C. S.; Akkurt, Mehmet; Chandraju, S.; Li, Hongqi

2012-01-01

158

Layered and self-penetrated cadmium isophthalate and 5-methylisophthalate coordination polymers containing bis(4-pyridylformyl)piperazine or bis(4-pyridylmethyl)homopiperazine ligands  

Microsoft Academic Search

Hydrothermal synthesis has afforded divalent cadmium coordination polymers containing isophthalate (ip) or 5-methylisophthalate (mip) dicarboxylate ligands and bis(4-pyridylformyl)piperazine (4-bpfp) or bis(4-pyridylmethyl)homopiperazine (4-bpmh) tethers. {[Cd2(ip)2(H2O)2(4-bpfp)]·7H2O}n (1) displays a (4,4) grid topology based on {Cd2O2} dimeric clusters, along with “infinite” water molecule tapes with rare T4(0)A(1) classification. {[Cd(mip)(H2O)(4-bpfp)]·3H2O}n (2) also exhibits (4,4) grid layers but with 2D+2D?3D mutual inclined interpenetration instead of

Amy L. Pochodylo; Curtis Y. Wang; Robert L. LaDuca

2011-01-01

159

catena-Poly[[[tetra-aqua-magnesium]-trans-?-[(piperazine-1,4-diium-1,4-di-yl)bis-(methyl-ene)]di-phospho-nato] hemihydrate  

PubMed Central

The structure of the title polymer, }[Mg(C6H14N2O6P2)(H2O)4]·0.5H2O}n, is based on centrosymmetric MgO6 octahedra, which are linked by [(piperazine-1,4-diium-1,4-di­yl)bis­(methyl­ene)]di­phospho­nate ligands, forming chains parallel to [1-1-1]. These chains are connected via hydrogen bonds primarily formed between the phospho­nate groups and water mol­ecules. The latter constitute four of the corners of the MgO6 polyhedra and bind to the O atoms of the phospho­nate groups of neighbouring chains. The lattice water molecule is disordered around an inversion centre, exhibiting an occupancy of 0.25.

Schilling, Lars-Hendrik; Stock, Norbert

2013-01-01

160

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

161

Synthesis and in vitro antiproliferative activity of 2-methyl-3-(2-piperazin-1-yl-ethyl)-pyrido[1,2-a]pyrimidin-4-one derivatives against human cancer cell lines.  

PubMed

A series of new 2-methyl-3-(2-piperazin-1-yl-ethyl)-pyrido[1,2-a]pyrimidin-4-one derivatives 6a-j were synthesized by a nucleophilic substitution reaction of 2-methyl-3-(2-piperazin-1-ylethyl)-pyrido[1,2-a]pyrimidin-4-one with various sulfonyl chlorides. The compounds were characterized by different spectral studies. All the compounds were evaluated for their antiproliferative effect using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay method against four human cancer cell lines (K562, Colo-205, MDA-MB 231, IMR-32) for the time period of 24 h. Among the series, compounds 6d, 6e and 6i showed good activity on all cell lines except K562, whereas the other compounds in the series exhibited moderate activity. Compound 6d could be a potential anticancer agent and therefore deserves further research. PMID:22297742

Mallesha, Lingappa; Mohana, Kikkeri N; Veeresh, Bantal; Alvala, Ravi; Mallika, Alvala

2012-02-02

162

tert-Butyl 4-{5-[3-(tri-fluoro-meth-oxy)phen-yl]-1,2,4-oxa-diazol-3-yl}piperazine-1-carboxyl-ate  

PubMed Central

In the title compound, C18H21F3N4O4, the piperazine ring adopts a chair conformation and the dihedral angle between the oxa­diazole and benzene rings is 6.45?(14)°. The C atoms and their attached H atoms in the piperazine ring are disordered, with site-occupation factors of 0.576?(12) and 0.424?(12). In the crystal, mol­ecules are linked through weak C—H?O inter­actions, generating an R 2 2(12) motif. Further, secondary C—H?O inter­molecular inter­actions link the mol­ecules into C(6) chains along [100].

Sreenivasa, Swamy; ManojKumar, Karikere Ekanna; Kempaiah, Arakyathanahalli; Suchetan, Parameshwar Adimoole; Palakshamurthy, Bandrehalli Siddagangaiah

2013-01-01

163

Preparation and biodistribution of 1-(2-(3-(/sup 125/I)iodo-4-aminophenyl)ethyl)-4-(3-(trifluoromethyl) phenyl)piperazine and 1-(2-(3-(/sup 125/I)iodo-4-azidophenyl)ethyl)-4-(3-(trifluoromethyl)phenyl) piperazine  

SciTech Connect

The iodinated analogue of 1-(2-(4-aminophenyl)ethyl)-4-(3-(trifluoromethyl)phenyl)piperazine (PAPP), IPAPP (4), and the corresponding azido compound azido-IPAPP (5) were synthesized. The corresponding no-carrier-added /sup 125/I (T1/2 = 60 days, 35-60 keV) labeled compounds were also prepared. High specific binding was observed from in vitro binding studies using rat brain tissue preparation; Ki = 20 and 17.5 nM against (/sup 3/H)-5-HT. In vivo biodistribution studies in rats showed that azido-(/sup 125/I)IPAPP passed through intact blood-brain barrier and localized in the brain. Ex vivo autoradiography of rat brain sections exhibited a diffuse uptake pattern, which may be due to specific and nonspecific binding. The results indicate that IPAPP and azido-IPAPP may not be suitable to image the serotonin receptor in the brain.

Chumpradit, S.; Kung, H.F.; Billings, J.; Guo, Y.Z.; Wu, Y.; Shih, J.

1989-03-01

164

Synthesis, spectroscopic and thermal studies of charge-transfer molecular complexes formed in the reaction of 1,4-bis (3-aminopropyl) piperazine with ?- and ? acceptors  

NASA Astrophysics Data System (ADS)

In the present study, solid charge-transfer (CT) molecular complexes formed in the reaction of the electron donor 1,4-bis (3-aminopropyl) piperazine (APPIP) with the ?-electron acceptor iodine and ?-acceptors 7,7,8,8-tetracyanoquinodimethane (TCNQ), tetracyanoethylene (TCNE), 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ), and 2,4,4,6-tetrabromo-2,5-cyclohexadienone (TBCHD) have been investigated spectrophotometrically in chloroform at 25 °C. These were characterized through electronic and infrared spectra as well as elemental and thermal analysis. The obtained results showed that the formed solid CT-complexes have the formulas [(APPIP) I]+I3-, [(APPIP)(TCNQ)], [(APPIP)2(TCNE)3], [(APPIP)(DDQ)] and [(APPIP)(TBCHD)] in full agreement with the known reaction stoichiometries in solution as well as the elemental measurements. The formation constant KCT, molar extinction coefficient &z.epsiv;CT, free energy change ?G0, CT energy ECT and the ionization potential Ip have been calculated for the CT complexes [(APPIP) I]+I3-, [(APPIP)(TCNQ)], [(APPIP)(DDQ)] and [(APPIP)(TBCHD)].

Alqaradawi, Siham Y.; Mostafa, Adel; Bazzi, Hassan S.

2012-03-01

165

Novel 4-(4-aryl)cyclohexyl-1-(2-pyridyl)piperazines as Delta(8)-Delta(7) sterol isomerase (emopamil binding protein) selective ligands with antiproliferative activity.  

PubMed

To find Delta(8)-Delta(7) sterol isomerase (EBP) selective ligands, various arylpiperazines previously studied and structurally related to some sigma receptors ligands were preliminarily screened. Consequently, a novel series of 2- or 2,6-disubstituted (CH(3), CH(3)O, Cl, F) cis- and trans-4-(4-aryl)cyclohexyl-1-(2-pyridyl)piperazines was developed. Radioreceptor binding assays evidenced cis-19, cis-30 and cis-33 as new ligands with nanomolar affinity toward EBP site and a good selectivity relative to EBP-related sigma receptors. The most selective 2,6-dimethoxy derivative (cis-33) demonstrated the highest potency (EC(50) = 12.9 microM) and efficacy (70%) in inhibiting proliferation of human prostate cancer PC-3 cell line. Among the reference compounds, sigma(2) agonist 36 (PB28) reached the maximum efficacy (100%), suggesting the contribution of the sigma(2) receptor to the antiproliferative activity. This novel class of EBP inhibitors represents a valuable tool for investigating the last steps of cholesterol biosynthesis and related pathologies, as well as a starting point for developing new anticancer drugs. PMID:19053780

Berardi, Francesco; Abate, Carmen; Ferorelli, Savina; de Robertis, Anna F; Leopoldo, Marcello; Colabufo, Nicola A; Niso, Mauro; Perrone, Roberto

2008-12-11

166

Collection and chemical derivatization of airborne phosgene with 1-(2-pyridyl)-piperazine and determination by high performance liquid chromatography  

SciTech Connect

As an alternative to currently available measurement methods, Chromosorb coated with 1-(2-pyridyl)-piperazine (PYP) was evaluated for collection/derivatization of phosgene gas. Solid sorbent tubes contained 100 mg of 2.5% PYP coated on Chromosorb. Phosgene reacts with two equivalents of PYP to form a substituted urea derivative which is desorbed with acetonitrile and determined by reversed phase high performance liquid chromatography with ultraviolet absorbance detection. In comparison to the 4,4[prime]-nitrobenzyl pyridine in diethylphthalate colorimetric technique, the recovery of phosgene from the sorbent tube was quantitative from 0.02 to 1 ppm phosgene and was unaffected by humidity. The limit of detection for a 20 L air sample was estimated to be 0.005 ppm. The utility of the method was further improved by demonstrating the use of triphosgene (bis-(trichloromethyl)-carbonate) in the synthesis of the urea derivative used for standardization, thus eliminating the need for working with gaseous phosgene in preparing analytical standards.

Rando, R.J.; Poovey, H.G. (Tulane Univ. Medical Center, New Orleans, LA (United States). Section of Bioenvironmental Research); Chang, Shau-nong (Tulane Univ. Medical Center, New Orleans, LA (United States). Dept. of Environmental Health Sciences)

1993-01-01

167

(Z)-2-(2-bromophenyl)-3-{[4-(1-methyl-piperazine)amino]phenyl}acrylonitrile (DG172): an orally bioavailable PPAR?/?-selective ligand with inverse agonistic properties.  

PubMed

The ligand-regulated nuclear receptor peroxisome proliferator-activated receptor ?/? (PPAR?/?) is a potential pharmacological target due to its role in disease-related biological processes. We used TR-FRET-based competitive ligand binding and coregulator interaction assays to screen 2693 compounds of the Open Chemical Repository of the NCI/NIH Developmental Therapeutics Program for inhibitory PPAR?/? ligands. One compound, (Z)-3-(4-dimethylamino-phenyl)-2-phenyl-acrylonitrile, was used for a systematic SAR study. This led to the design of derivative 37, (Z)-2-(2-bromophenyl)-3-{[4-(1-methyl-piperazine)amino]phenyl}acrylonitrile (DG172), a novel PPAR?/?-selective ligand showing high binding affinity (IC(50) = 27 nM) and potent inverse agonistic properties. 37 selectively inhibited the agonist-induced activity of PPAR?/?, enhanced transcriptional corepressor recruitment, and down-regulated transcription of the PPAR?/? target gene Angptl4 in mouse myoblasts (IC(50) = 9.5 nM). Importantly, 37 was bioavailable after oral application to mice with peak plasma levels in the concentration range of its maximal inhibitory potency, suggesting that 37 will be an invaluable tool to elucidate the functions and therapeutic potential of PPAR?/?. PMID:22369181

Lieber, Sonja; Scheer, Frithjof; Meissner, Wolfgang; Naruhn, Simone; Adhikary, Till; Müller-Brüsselbach, Sabine; Diederich, Wibke E; Müller, Rolf

2012-03-08

168

Periodic density functional theory study of the high-pressure behavior of energetic crystalline 1,4-dinitrofurazano[3, 4-b]piperazine.  

PubMed

A detailed study of the structural, electronic, and optical absorption properties of crystalline 1,4-dinitrofurazano[3,4-b]piperazine (DNFP) under hydrostatic pressures of 0-100 GPa was performed using periodic density functional theory. As the pressure increases, the lattice constants and cell volumes calculated by LDA gradually approach those obtained by GGA-PW91. It was found that the structure of DNFP is much stiffer in the b direction than along the a and c axes, indicating that the compressibility of the crystal is anisotropic. As the pressure increases, the band gap gradually decreases, and this decrease is more pronounced in the low-pressure range than in the high-pressure region. An analysis of the density of states showed that the electronic delocalization in DNFP gradually increases under the influence of pressure. DNFP exhibits relatively high optical activity at high pressure. As the pressure increases, the bands in the fundamental absorption region of the absorption spectrum of DNFP become more numerous and intense. PMID:22890750

Wang, Wentao; Zhu, Weihua; Li, Jinshan; Cheng, Bibo; Xiao, Heming

2012-08-14

169

Radiosynthesis binding affinity and biodistribution of 3-[F-18]fluoro-N-({alpha},{alpha},{alpha}-trifluoro-m-tolyl)piperazine (FTFMPP), a radioligand for the Serotonin system  

SciTech Connect

The serotonin agonist N({alpha},{alpha},{alpha}-trifluoro-m-tolyl)piperazine (TFMPP) is a potent ligand for the serotonin system. Angelini and co-workers previously synthesized the c.a [F-18]TFMPP but the low specific activity (less than 0.2GBq/mmol) limited the application of this ligand. We have recently reported the formation of phenylpiperazines by a novel alumina supported bis-alkylation. We report the application of this method and biological evaluation of 3-[F-18]FTFMPP, a fluoro derivative of TFMPP. Reaction of [F-18]fluoride with 3,5-dinitrobenzotrifluoride gave the 3-[F-18]fluoro-5-nitrobenzotrifluoride in 70% yield. Reduction of the nitro group with Raney nickel and hydrazine hydrate gave the [F-18]aniline derivative in 70% yield. Finally, the phenylpiperazine was constructed by reaction of the [F-18]aniline derivative with bis-2-bromoethyl-N-(ethoxy carbonyl)amine on basic alumina (pH=9) as a solid support. After extraction of the activity with basic MeOH and HPLC purification on normal phase the final product- [F-18]FTFMPP was obtained in 50% yield (98% radiochemical purity). The specific activity of the final product was 100GBq/mmol. The binding affinity of FTFMPP to 5-HT receptor was determined (Ki = 80-100 nM) and found to be similar to the binding affinity of the TFMPP (160-180 nM). The biodistribution of [F-18]FTFMPP was performed in rats.

Mishani, E.; Cristel, M.E.; McCarthy, T.J.; Welch, M.J. [Washington Univ., Saint Louis, MO (United States)

1996-05-01

170

Converting to DEA\\/MDEA mix ups sweetening capacity  

Microsoft Academic Search

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

MICHAEL L. SPEARS; KATHY M. HAGAN; JERRY A. BULLIN; CARL J. MICHALIK

1996-01-01

171

Evaluation of antinociceptive and antioxidant properties of 3-[4-(3-trifluoromethyl-phenyl)-piperazin-1-yl]-dihydrofuran-2-one in mice.  

PubMed

The aim of this study was to evaluate the influence of 3-[4-(3-trifluoromethyl-phenyl)-piperazin-1-yl]-dihydrofuran-2-one (LPP1) on nociceptive thresholds in mouse models of persistent pain. Influence of LPP1 on motor coordination and its antioxidant capacity in mouse brain tissue homogenates were also assessed. Pain sensitivity thresholds in animals treated with LPP1 were established using 5 % formalin solution in normoglycemic mice and in streptozotocin (STZ)-treated diabetic mice in the von Frey, hot plate, innocuous, and noxious cold water tests (water at 10 °C and 4 °C, respectively). Motor deficits were assessed in the rotarod test, whereas antioxidant capacities were evaluated using ferric reducing ability of plasma (FRAP) assay, catalase (CAT), and superoxide dismutase (SOD) activities. LPP1was antinociceptive in both phases of the formalin test, in particular, in the late phase (at doses 0.9-30 mg/kg for 66-99 % vs. control normoglycemic mice) and in a statistically significant manner increased nociceptive thresholds in response to mechanical, heat, and noxious cold stimulation in neuropathic mice (at 30 mg/kg for 274, 192, and 316 %, respectively vs. diabetic control). LPP1 did not impair motor coordination of mice in the rotarod revolving at 6 or 18 rpm. In brain tissue homogenates, it demonstrated antioxidant capacity in FRAP assay and increased SOD activity for 63 % (acute administration) and 28 % (chronic administration) vs. control. No influence on CAT activity was observed. LPP1 has significant antinociceptive properties in the formalin model and elevates pain thresholds in neuropathic mice. It has antioxidant capacity and is devoid of negative influence on animals' motor coordination. PMID:23494125

Sa?at, Kinga; Gawlik, Katarzyna; Witalis, Jadwiga; Pawlica-Gosiewska, Dorota; Filipek, Barbara; Solnica, Bogdan; Wi?ckowski, Krzysztof; Malawska, Barbara

2013-03-14

172

Effects of the Sigma-1 Receptor Agonist 1-(3,4-Dimethoxyphenethyl)-4-(3-Phenylpropyl)-Piperazine Dihydro-Chloride on Inflammation after Stroke  

PubMed Central

Activation of the sigma-1 receptor (Sig-1R) improves functional recovery in models of experimental stroke and is known to modulate microglia function. The present study was conducted to investigate if Sig-1R activation after experimental stroke affects mediators of the inflammatory response in the ischemic hemisphere. Male Wistar rats were subjected to transient occlusion of the middle cerebral artery (MCAO) and injected with the specific Sig-1R agonist 1-(3,4-dimethoxyphenethyl)-4-(3-phenylpropyl)piperazine dihydrochloride (SA4503) or saline for 5 days starting on day 2 after MCAO. Treatment did not affect the increased levels of the pro-inflammatory cytokines interleukin 1 beta (IL-1?), tumor necrosis factor alpha (TNF-?), interferon gamma (IFN-?), interleukin 4 (IL-4), interleukin 5 (IL-5), and interleukin 13 (IL-13) in the infarct core and peri-infarct area after MCAO. In addition, treatment with SA4503 did not affect elevated levels of nitrite, TNF-? and IL-1? observed in primary cultures of microglia exposed to combined Hypoxia/Aglycemia, while the unspecific sigma receptor ligand 1,3-di-o-tolylguanidine (DTG) significantly decreased the production of nitrite and levels of TNF-?. Analysis of the ischemic hemisphere also revealed increased levels of ionized calcium binding adaptor molecule 1 (Iba1) levels in the infarct core of SA4503 treated animals. However, no difference in Iba1 immunoreactivity was detected in the infarct core. Also, levels of the proliferation marker proliferating cell nuclear antigen (PCNA) and OX-42 were not increased in the infarct core in rats treated with SA4503. Together, our results suggest that sigma-1 receptor activation affects Iba1 expression in microglia/macrophages of the ischemic hemisphere after experimental stroke but does not affect post-stroke inflammatory mediators.

Ruscher, Karsten; Inacio, Ana R.; Kuric, Enida; Wieloch, Tadeusz

2012-01-01

173

Carbon dioxide adsorption by physisorption and chemisorption interactions in piperazine-grafted Ni2(dobdc) (dobdc = 1,4-dioxido-2,5-benzenedicarboxylate).  

PubMed

The metal-organic framework Ni(2)(dobdc) (CPO-27-Ni, where dobdc = 1,4-dioxido-2,5-benzenedicarboxylate) has been post-synthetically modified with piperazine (pip) - a known 'accelerator' to improve the kinetics of CO(2) uptake in alkanolamine solvents for chemical absorption - and the impact of the modification on the CO(2) uptake and selectivity over N(2) has been probed. While the modified framework, Ni(2)(dobdc)(pip)(0.5) (pip-CPO-27-Ni), exhibits a lower uptake of CO(2) compared with the non-grafted material, the selectivity for CO(2) over N(2) at 25 °C and at pressures pertinent to post-combustion flue gas capture (0.1-0.15 bar) is enhanced. Mechanistically, the interaction between the CO(2) molecules and the free amine sites in pip-CPO-27-Ni occurs via physisorption and chemisorption interactions, in which CO(2) binds to the framework with an isosteric heat of adsorption (-Q(st)) of 40.5 kJ mol(-1) at very low coverage (P = 0.033 mbar), followed by binding at a higher heat of adsorption (-Q(st) = 46.2 kJ mol(-1) at P = 3.55 mbar). Pure water adsorption isotherms revealed a two-step mechanism for uptake in CPO-27-Ni, consistent with adsorption into the first and second hydration spheres of Ni(2+) followed by subsequent uptake via physisorption into the pores. Additional steric hindrance in pip-CPO-27-Ni results in a single step only. The working capacity over multiple cycles was also investigated using a temperature swing adsorption process which revealed reversible CO(2) adsorption and desorption of 10 wt% over 10 cycles. PMID:22903310

Das, Anita; Southon, Peter D; Zhao, Ming; Kepert, Cameron J; Harris, Andrew T; D'Alessandro, Deanna M

2012-08-17

174

(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  

Microsoft Academic Search

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 = 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

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

2010-01-01

175

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

Microsoft Academic Search

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 (IC50=13nM) 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

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

2009-01-01

176

Synthesis and evaluation of novel 1-(1 H-1,2,4-triazol-1-yl)-2-(2,4-difluorophenyl)-3-[(4-substitutedphenyl)-piperazin-1-yl]-propan-2-ols as antifungal agents  

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, 1H NMR and 13C NMR. Results of preliminary antifungal tests against six human pathogenic fungi (Candida albicans, Candida parapsilosis, Cryptococcus neoformans, Candida tropicalis, inherently fluconazole-resistant Candida krusei, Candida

Qing-Yan Sun; Wan-Nian Zhang; Jian-Ming Xu; Yong-Bing Cao; Qiu-Ye Wu; Da-Zhi Zhang; Chao-Mei Liu; Shi-Chong Yu; Yuan-Ying Jiang

2007-01-01

177

(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

178

One-dimensional structures of zinc(II) and cobalt(II) coordination complexes [Zn(NCS) 2(PPz)] n and [CoCl 2(PPz)] n (PPz=piperazine)  

Microsoft Academic Search

The reaction of Zn(NO3)2·6H2O with PPz hexahydrate (PPz=piperazine) and NH4SCN in CH3OH afforded the complex [Zn(NCS)2(PPz)]n (1). The reaction of CoCl2·6H2O with PPz in CH3OH afforded the complex [CoCl2(PPz)]n (2). The PPz ligand in 1 is coordinated to the metal centers through both nitrogen atoms to form a 1-D zigzag-chain structure and the distorted tetrahedral coordination geometry at each zinc

Maw-Cherng Suen; Tai-Chiun Keng; Ju-Chun Wang

2002-01-01

179

Microwave-assisted synthesis of 4-chloro-N-(naphthalen-1-ylmethyl)-5-(3-(piperazin-1-yl)phenoxy)thiophene-2-sulfonamide (B-355252): a new potentiator of Nerve Growth Factor (NGF)-induced neurite outgrowth  

PubMed Central

The synthesis of 4-chloro-N-(naphthalen-1-ylmethyl)-5-(3-(piperazin-1-yl)phenoxy)thiophene-2-sulfonamide (B-355252) using a MW-assisted nucleophilic aromatic substitution (SNAr) reaction will be discussed. Utilization of this method allowed for the rapid generation of B-355252 heteroaryl ether core structure in the presence of cesium carbonate in dimethylformamide or tripotassium phosphate in N-methyl-2-pyrrolidone in 94% yield. Evaluation of B-355252 enhancement of nerve growth factor’s ability to stimulate neurite outgrowths was determined using NS-1 cells.

Williams, Alfred L.; Dandepally, Srinivasa R.; Gilyazova, Nailya; Witherspoon, Sam M; Ibeanu, Gordon

2010-01-01

180

Synthesis and in-vitro antibacterial activity of some novel N-nicotinoyl-1-ethyl-6-fluoro-1,4-dihydro-7-piperazin-1-yl-4-oxoquinoline-3-carboxylates.  

PubMed

A series of N-nicotinoyl-1-ethyl-6-fluoro-1,4-dihydro-7-piperazin-1-yl-4-oxoquinoline-3-carboxylates has been synthesized and evaluated for antibacterial activity. Norfloxacin was reacted with thionyl chloride, to yield norfloxacin acid chloride which was used immediately in next step by reacting with respective alcohols to furnish the corresponding esters i.e. 1-ethyl-6-fluoro-1,4-dihydro-7-piperazin-1-yl-4-oxoquinoline-3-carboxylates (III). Nicotinoyl chloride (IV) was prepared by adopting reported procedures and was reacted appropriately with previously synthesized esters (III) to yield the title compounds (V). The structures of synthesized compounds were established on the basis of analytical and spectral studies. All the synthesized compounds were evaluated for antibacterial activity against four different strains of bacteria. Compounds exhibited moderate to significant minimum inhibitory concentration (MIC) values ranging from 0.19 to 0.37 against E. coli, 0.17 to 0.37 against S. dysentry. The MIC values against Gram positive bacteria were slightly more that Gram negative ones and ranged from 1.9 to 3.5 against S. aureus and 2.0 to 3.1 against B. subtilis. PMID:19051601

Sharma, Prabodh Chander; Jain, Sandeep

181

Design, synthesis, radiolabeling and in vivo evaluation of carbon-11 labeled N-[2-[4-(3-cyanopyridin-2-yl)piperazin-1-yl]ethyl]-3-methoxybenzamide, a potential Positron Emission Tomography tracer for the dopamine D4 receptors  

PubMed Central

Here we describe the design, synthesis, physicochemical, and pharmacological evaluation of D4 dopamine receptor ligands related to N-[2-[4-(4-chlorophenyl)piperazin-1-yl]ethyl]-3-methoxybenzamide (2). Structural features were incorporated to increase affinity for the target receptor, to improve selectivity over D2 and sigma1 receptors, to enable labeling with carbon-11 or fluorine-18, and to adjust lipophilicity within the range considered optimal for brain penetration and low nonspecific binding. Compounds 7 and 13 showed the overall best characteristics: nanomolar affinity for the D4 receptor, > 100-fold selectivity over D2 and D3 dopamine receptor 5-HT1A, 5-HT2A and 5-HT2C serotonin receptors and sigma1 receptors, and logP = 2.37–2.55. Following intraperitoneal administration, both compounds rapidly entered the central nervous system. The methoxy of N-[2-[4-(3-cyanopyridin-2-yl)piperazin-1-yl]ethyl]-3-methoxybenzamide (7) was radiolabelled with carbon-11 and subjected to PET analysis in non-human primate. [11C]7 time-dependently accumulated to saturation in the posterior eye in the region of the retina, a tissue containing a high density of D4 receptors.

Lacivita, Enza; De Giorgio, Paola; Lee, Irene T.; Rodeheaver, Sean I.; Weiss, Bryan A.; Fracasso, Claudia; Caccia, Silvio; Berardi, Francesco; Perrone, Roberto; Zhang, Ming-Rong; Maeda, Jun; Higuchi, Makoto; Suhara, Tetsuya; Schetz, John A.; Leopoldo, Marcello

2010-01-01

182

Exploring the importance of piperazine N-atoms for sigma(2) receptor affinity and activity in a series of analogs of 1-cyclohexyl-4-[3-(5-methoxy-1,2,3,4-tetrahydronaphthalen-1-yl)propyl]piperazine (PB28).  

PubMed

sigma(2)-Agonist 1-cyclohexyl-4-[3-(5-methoxy-1,2,3,4-tetrahydronaphthalen-1-yl)propyl]piperazine (7, PB 28), which proved to revert doxorubicin resistance in breast cancer cells, was taken as a template to prepare new analogs. One of the two basic N-atoms was alternatively replaced by a methine or converted into an amide or ammonium function, with the aim of finding out which of them was essential for sigma(2) receptor affinity and activity. Some simply 4-substituted 1-cyclohexylpiperazines were also investigated. None of the compounds was as high-affinity as 7 (sigma(2)K(i) = 0.68, sigma(1)K(i) = 0.38 nM), proving that both basic N-atoms ensure better sigma(2) receptor binding. Amide 36 emerged as high-affinity (K(i) = 0.11 nM) and noteworthy() selective (1627-fold) sigma(1) ligand. Small N-cyclohexylpiperazine 59 displayed the highest sigma(2) affinity (K(i) = 4.70 nM). The sigma(2)/sigma(1) selectivities were generally low. Antiproliferative assay in SK-N-SH cells revealed piperidines 24 and 15 as putative sigma(2) agonists (EC(50)s 1.40 and 3.64 muM respectively) more potent than 7. PMID:19842660

Berardi, Francesco; Abate, Carmen; Ferorelli, Savina; Uricchio, Vincenzo; Colabufo, Nicola A; Niso, Mauro; Perrone, Roberto

2009-12-10

183

Surface tension and foam behaviour of aqueous solutions of blends of three alkanolamines, as a function of temperature  

Microsoft Academic Search

We have determined the equilibrium surface tension for aqueous solutions of three alkanolamines composed of 32.5mass% N-methyldiethanolamine (MDEA) and 12.5mass% diethanolamine (DEA) with the addition of 2, 4, 6, 8, and 10mass% of 2-amino-2-methyl-1-propanol (AMP), at 303.15, 308.15, 313.15, 318.15, 323.15, 328.15, 333.15, 338.15, and 343.15K. We have also determined experimentally the foaming properties for the same aqueous solutions of

Jacinto Águila-Hernández; Arturo Trejo; Blanca Estela García-Flores

2007-01-01

184

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

1996-07-01

185

Bivalent ligand approach on 4-[2-(3-methoxyphenyl)ethyl]-1-(2-methoxyphenyl)piperazine: synthesis and binding affinities for 5-HT(7) and 5-HT(1A) receptors.  

PubMed

We here report on the synthesis and binding properties at 5-HT(7) and 5-HT(1A) receptors of ligands 3-12, that were designed according to the 'bivalent ligand' approach. Two moieties of the 5-HT(7)/5-HT(1A) ligand 4-[2-(3-methoxyphenyl)ethyl]-1-(2-methoxyphenyl)piperazine (1) were linked through their 3-methoxy substituent by polymethylene chains of variable length, with the aim to increase the affinity for 5-HT(7) receptor and the selectivity over 5-HT(1A) receptors. In the best cases, the dimers showed affinities for 5-HT(7) receptors as high as the monomer with no improvement in selectivity. Some dimers displayed 5-HT(1A) receptor affinities slightly higher than monomer 1. PMID:17517509

Leopoldo, Marcello; Lacivita, Enza; Colabufo, Nicola A; Niso, Mauro; Berardi, Francesco; Perrone, Roberto

2007-05-06

186

N-{[2-(4-Phenyl-piperazin-1-yl)-ethyl]-phenyl}-arylamides with Dopamine D2 and 5-Hydroxytryptamine 5HT1 A Activity: Synthesis, Testing, and Molecular Modeling.  

PubMed

The ratio of affinities toward the dopamine D2 and the 5-hydroxytryptamine 5-HT1A receptors is one of the important parameters that determine the efficiency of antipsychotic drugs. Here, we present the synthesis of ortho-, meta-, and para-N-{[2-(4-phenyl-piperazin-1-yl)-ethyl]-phenyl}-arylamides and their structure-activity relationship studies on dopamine D2 and 5-hydroxytryptamine 5-HT1A receptors. It was shown that the biological activity of the described ligands strongly depends on their topology as well as on the nature of the heteroaryl group in the head of the molecules. Docking simulations together with conformational analysis revealed a rational explanation for the ligands' behavior. The molecular model of receptor-ligand interactions described herein provided us with a tool for the rational design of new compounds with a favorable D2 /5-HT1A profile. PMID:24105736

Sukalovic, Vladimir; Bogdan, Anca Elena; Tovilovic, Gordana; Ignjatovic, Djurdjica; Andric, Deana; Kostic-Rajacic, Sladjana; Soskic, Vukic

2013-09-16

187

Poly[[bis-[?(2)-8-ethyl-5-oxo-2-(piperazin-1-yl)-5,8-dihydro-pyrido[2,3-d]pyrimidine-6-carboxyl-ato]zinc(II)] dihydrate].  

PubMed

The title compound, {[Zn(C(14)H(16)N(5)O(3))(2)]·2H(2)O}(n) or [Zn(ppa)(2)]·2H(2)O}(n), where ppa = 8-ethyl-5,8-dihydro-5-oxo-2-(1-piperazin-yl)-pyrido(2,3-d)-pyrimidine-6-carboxyl-ate, was synthesized under hydro-thermal conditions. The Zn(II) atom (site symmetry ) exhibits a distorted trans-ZnN(2)O(4) octa-hedral geometry defined by two monodentate N-bonded and two bidentate O,O-bonded ppa monoanions. The extended two-dimensional structure arising from this connectivity is a square grid and the disordered uncoordinated water mol-ecules occupy cavities within the grid. An N-H?O hydrogen bond occurs. PMID:21577745

Xu, Wen; Zhu, Da-Sheng; Song, Xiao-Dan; An, Zhe

2009-09-19

188

Acute toxicity and primary irritancy of alkylalkanolamines.  

PubMed

The acute handling hazards of several alkylalkanolamines were determined by investigating their potential acute toxicity and primary irritancy. Materials studied were N-methylethanolamine (MEA), N, N, -dimethylethanolamine (DMEA), N, N, -dimethylisopropanolamine (DMIPA), N-methyldiethanolamine (MDEA), and tertbutyldiethanolamine (BDEA). All these alkylalkanolamines were of comparable acute peroral toxicity in the rat (LD50 range 1.48-2.83 ml/kg). By 24 h occluded epicutaneous contact in the rabbit, MEA, DMEA and DMIPA were of moderate acute percutaneous toxicity (LD50 range 1.13-2.0 ml/kg), MDEA was of slight acute percutaneous toxicity (LD50 male 9.85 ml/kg, female 10.90 ml/kg), and BDEA of intermediate toxicity (LD50 6.4 ml/kg). Due to differences in vapor pressure the acute vapor exposure toxicity of the alkylalkanolamines to rats varied; MEA, MDEA and BDEA were of a low order of acute toxicity, and DMIPA was moderately toxic with an LT50 of 3.2 h for a saturated vapor atmosphere exposure. A 4 h-LC50 (rat combined sex) of 1461 ppm was determined for DMEA. All alkylalkanolamines studied, except MDEA, were moderately to markedly irritating and caused variable degrees of skin corrosivity; MDEA caused only transient minor skin irritation. In accord with the skin irritancy results, the eye irritancy from 0.005 ml MEA, DMEA, DMIPA and BDEA was severe, and that from MDEA was slight. Exposure to these compounds has implications for occupational health procedures. PMID:8948072

Ballantyne, B; Leung, H W

1996-12-01

189

Mixed-amine Modified SBA15 as Novel Adsorbent of CO2 Separation for Biogas Upgrading  

Microsoft Academic Search

A novel adsorbent of CO2 from biogas was prepared by synthesizing and modifying the mesoporous molecular silica of SBA-15 with methyl-diethyl-amine (MDEA) and piperazine (PZ). The adsorbent showed good performance in separating CO2 from biogas. The loaded amines did not change the ordered structure of SBA-15, but enhanced its adsorption of CO2. The adsorbents were characterized by X-ray powder diffraction

Quanmin Xue; Yingshu Liu

2011-01-01

190

Fluorescent derivatives of ? receptor ligand 1-cyclohexyl-4-[3-(5-methoxy-1,2,3,4-tetrahydronaphthalen-1-yl)propyl]piperazine (PB28) as a tool for uptake and cellular localization studies in pancreatic tumor cells.  

PubMed

Fluorescent derivatives of ?(2) high affinity ligand 1-cyclohexyl-4-[3-(5-methoxy-1,2,3,4-tetrahydronaphthalen-1-yl)propyl]piperazine 1 (PB28) were synthesized. NBD or dansyl fluorescent tags were connected through a 5- or 6-atom linker in two diverse positions of 1 structure. Good ?(2) affinities were obtained when the fluorescent tag was linked to 5-methoxytetralin nucleus replacing the methyl function. NBD-bearing compound 16 displayed high ?(2) affinity (K(i) = 10.8 nM) and optimal fluorescent properties. Its uptake in pancreatic tumor cells was evaluated by flow cytometry, showing that it partially occurs through endocytosis. In proliferating cells, the uptake was higher supporting that ?(2) receptors are markers of cell proliferation and that the higher the proliferation is, the stronger the antiproliferative effect of ?(2) agonists is. Colocalization of 16 with subcellular organelles was studied by confocal microscopy: the greatest was in endoplasmic reticulum and lysosomes. Fluorescent ?(2) ligands show their potential in clarifying the mechanisms of action of ?(2) receptors. PMID:21744858

Abate, Carmen; Hornick, John R; Spitzer, Dirk; Hawkins, William G; Niso, Mauro; Perrone, Roberto; Berardi, Francesco

2011-07-20

191

1D + 1D ? 1D polyrotaxane, 2D + 2D ? 3D interpenetrated, and 3D self-penetrated divalent metal terephthalate bis(pyridylformyl)piperazine coordination polymers.  

PubMed

Divalent metal coordination polymers containing terephthalate (tere) and bis(4-pyridylformyl)piperazine (bpfp) show diverse and interesting two-dimensional (2D) interpenetrated, three-dimensional (3D) self-penetrated, or one-dimensional (1D) polyrotaxane topological features. Isostructural {[M(tere)(bpfp)(H(2)O)(2)]•4H(2)O}(n) phases (1, Zn; 2, Co) exhibit mutually inclined 2D + 2D ? 3D interpenetration of gridlike layers. {[Cd(4)(tere)(4)(bpfp)(3)(H(2)O)(2)]·8H(2)O}(n) (3) possesses a novel 3,4,8-connected trinodal self-penetrated network with (4.6(2))(2)(4(2)6(16)8(7)10(3))(4(2)6(4))(2) topology. [Zn(2)Cl(2)(tere)(bpfp)(2)](n) (4) is the first example of a 1D + 1D ? 1D polyrotaxane coordination polymer, to the best of our knowledge. Metal coordination geometry plays a crucial role in dictating the overall dimensionality in this system. Thermal decomposition behavior and luminescent properties of the d(10) configuration metal derivatives are also presented herein. PMID:21776990

Wang, Curtis Y; Wilseck, Zachary M; LaDuca, Robert L

2011-07-21

192

Identification of a small molecule 1,4-bis-[4-(3-phenoxy-propoxy)-but-2-ynyl]-piperazine as a novel inhibitor of the transcription factor p53  

PubMed Central

Aim: To identify novel small compound inhibitor of p53 protein. Methods: Mouse embryonic fibroblasts (MEF) and mouse embryonic stem (ES) cells were tested. Cell proliferation rate was determined using a Cell Proliferation Kit. The mRNA and protein levels of p53-related genes were measured using real-time PCR and Western blotting, respectively. Global response in the p53 signaling network was analyzed using Illumina whole-genome expression BeadChips. Results: Treatment of MEF cells with a small molecule 1,4-bis-[4-(3-phenoxy-propoxy)-but-2-ynyl]-piperazine (G5) at 10 ?mol/L for 24 h markedly reduced the mRNA and protein levels of the p53 downstream genes MDM2 and p21. In G5-treated ES cells, a total of 372 differentially expressed genes were identified, and 18 among them were direct downstream genes of p53; 6 out of 9 p53-repressed genes were upregulated, and 5 out of 9 p53-activated genes were downregulated. In both MEF cells and ES cells, treatment of with G5 (10 ?mol/L) up to 48 h neither affected the proliferation rate nor caused morphological alterations. Conclusion: G5 inhibits p53 activity and simultaneously preserves the normal growth and proliferation of cells, therefore is a new compound for studies of p53-mediated cell manipulation.

Liu, Xin; Zhang, Ying; Tong, Man; Liu, Xiu-ying; Luo, Guan-zheng; Xie, Dong-fang; Ren, Shao-fang; Bai, Dong-hui; Wang, Liu; Zhou, Qi; Wang, Xiu-jie

2013-01-01

193

Thermodynamic properties and ideal-gas enthalpies of formation for dicyclohexyl sulfide, diethylenetriamine, di-n-octyl sulfide, dimethyl carbonate, piperazine, hexachloroprop-1-ene, tetrakis(dimethylamino)ethylene, N,N{prime}-bis-(2-hydroxyethyl)ethylenediamine, and 1,2,4-triazolo[1,5-a]pyrimidine  

SciTech Connect

The results of the study are aimed at improvement of group-contribution methodology for estimation of thermodynamic properties of organic substances. Specific weaknesses where particular group-contribution terms were unknown, or estimated because of lack of experimental data, are addressed by experimental studies of enthalpies of combustion in the condensed phase, vapor-pressure measurements, and differential scanning calorimetric (DSC) heat-capacity measurements. Ideal-gas enthalpies of formation of hexachloroprop-1-ene, N,N{prime}-bis(2-hydroxyethyl)ethylenediamine, dimethyl carbonate, di-n-octyl sulfide, dicyclohexyl sulfide, diethylenetriamine, tetrakis(dimethylamino)ethylene, piperazine, and 1,2,4-triazolo[1,5-a]pyrimidine are reported. Enthalpies of fusion were determined for N,N{prime}-bis(2-hydroxyethyl)ethylenediamine, piperazine and 1,2,4-triazolo[1,5-a]pyrimidine. Two-phase (solid + vapor) or (liquid + vapor) heat capacities were determined from 300 K to the critical region or earlier decomposition temperature for each compound studied. Liquid-phase densities along the saturation line were measured for N,N{prime}-bis(2-hydroxyethyl)ethylenediamine, dimethyl carbonate, and dicyclohexyl sulfide. For dimethyl carbonate and piperazine, critical temperatures and critical densities were determined from the DSC results and corresponding critical pressures derived from the fitting procedures. Fitting procedures were used to derive critical temperatures, critical pressures, and critical densities for hexachloroprop-1-ene, di-n-octyl sulfide, dicyclohexyl sulfide, and diethylenetriamine. Group-additivity parameters and 1,4-interaction terms useful in the application of group-contribution correlations were derived.

Steele, W.V.; Chirico, R.D.; Knipmeyer, S.E.; Nguyen, A.; Smith, N.K. [National Inst. for Petroleum and Energy Research, Bartlesville, OK (United States)

1997-11-01

194

Collection of VLE data for acid gas-alkanolamine systems using Fourier transform infrared spectroscopy  

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.

1991-09-01

195

Collection of VLE data for acid gas-alkanolamine systems using Fourier transform infrared spectroscopy. Phase 1, September 29, 1990--September 30, 1991  

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.

1991-09-01

196

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

197

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

198

Studies of the biogenic amine transporters. XI. Identification of a 1-[2-[bis(4-fluorophenyl)methoxy]ethyl]-4-(3-phenylpropyl)piperazine (GBR12909) analog that allosterically modulates the serotonin transporter.  

PubMed

Previous studies identified partial inhibitors of serotonin (5-HT) transporter and dopamine transporter binding. We report here on a partial inhibitor of 5-HT transporter (SERT) binding identified among a group of 1-[2-[bis(4-fluorophenyl)methoxy]ethyl]-4-(3-phenylpropyl)piperazine analogs (4-[2-[bis(4-fluorophenyl)-methoxy]ethyl]-1-(2-trifluoromethyl-benzyl)-piperidine; TB-1-099). Membranes were prepared from rat brains or human embryonic kidney cells expressing the cloned human dopamine (hDAT), serotonin (hSERT), and norepinephrine (hNET) transporters. beta-(4'-(125)Iodophenyl)tropan-2beta-carboxylic acid methyl ester ([(125)I]RTI-55) binding and other assays followed published procedures. Using rat brain membranes, TB-1-099 weakly inhibited DAT binding (K(i) = 439 nM), was inactive at NET binding ([(3)H]nisoxetine), and partially inhibited SERT binding with an extrapolated plateau ("A" value) of 20%. Similarly, TB-1-099 partially inhibited [(125)I]RTI-55 binding to hSERT with an extrapolated plateau (A value) of 14%. Upon examining the effect of increasing concentrations of TB-1-099 on the apparent K(d) and B(max) of [(125)I]RTI-55 binding to hSERT, we found that TB-1-099 decreased the B(max) in a dose-dependent manner and affected the apparent K(d) in a manner well described by a sigmoid dose-response curve. TB-1-099 increased the K(d) but not to the magnitude expected for a competitive inhibitor. In rat brain synaptosomes, TB-1-099 noncompetitively inhibited [(3)H]5-HT, but not [(3)H]dopamine, uptake. Dissociation experiments indicated that TB-1-099 promoted the rapid dissociation of a small component of [(125)I]RTI-55 binding to hSERT. Association experiments demonstrated that TB-1-099 slowed [(125)I]RTI-55 binding to hSERT in a manner unlike that of the competitive inhibitor indatraline. Viewed collectively, these results support the hypothesis that TB-1-099 allosterically modulates hSERT binding and function. PMID:15860577

Nightingale, Barbara; Dersch, Christina M; Boos, Terrence L; Greiner, Elisabeth; Calhoun, William J; Jacobson, Arthur E; Rice, Kenner C; Rothman, Richard B

2005-04-28

199

Buffer Standards for pH Measurement of N-(2-Hydroxyethyl)piperazine-N'-2-ethanesulfonic Acid (HEPES) for I = 0.16 mol.kg from 5 to 55 degrees C.  

PubMed

The values of the second dissociation constant, pK(2) of N-(2-hydroxyethyl) piperazine-N'-2-ethanesulfonic acid (HEPES) have been reported at 12 temperatures over the temperature range 5 to 55 degrees C, including 37 degrees C. This paper reports the results for the pa(H) of eight isotonic saline buffer solutions with an I = 0.16 mol*kg(-1) including compositions: (a) HEPES (0.01 mol*kg(-1)) + NaHEPES (0.01 mol*kg(-1)) + NaCl (0.15 mol*kg(-1)); (b) HEPES (0.02 mol*kg(-1)) + NaHEPES (0.02 mol*kg(-1)) + NaCl (0.14 mol*kg(-1)); (c) HEPES (0.03 mol*kg(-1)) + NaHEPES (0.03 mol*kg(-1)) + NaCl (0.13 mol*kg(-1)); (d) HEPES (0.04 mol*kg(-1)) + NaHEPES (0.04 mol*kg(-1)) + NaCl (0.12 mol*kg(-1)); (e) HEPES (0.05 mol*kg(-1)) + NaHEPES (0.05 mol*kg(-1)) + NaCl (0.11 mol*kg(-1)); (f) HEPES (0.06 mol*kg(-1)) + NaHEPES (0.06 mol*kg(-1)) + NaCl (0.10 mol*kg(-1)); (g) HEPES (0.07 mol*kg(-1)) + NaHEPES (0.07 mol*kg(-1)) + NaCl (0.09 mol*kg(-1)); and (h) HEPES (0.08 mol*kg(-1)) + NaHEPES (0.08 mol*kg(-1)) + NaCl (0.08 mol*kg(-1)). Conventional pa(H) values, for all eight buffer solutions from 5 to 55 degrees C have been calculated. The operational pH values with liquid junction corrections, at 25 and 37 degrees C have been determined based on the NBS/NIST standard between the physiological phosphate standard and four buffer solutions. These are recommended as pH standards for physiological fluids in the range of pH 7.3 to 7.5 at I = 0.16 mol*kg(-1). PMID:20161485

Roy, Rabindra N; Roy, Lakshmi N; Ashkenazi, Shahaf; Wollen, Joshua T; Dunseth, Craig D; Fuge, Michael S; Durden, Jared L; Roy, Chandra N; Hughes, Hannah M; Morris, Brett T; Cline, Kevin L

2009-04-01

200

21 CFR 520.1807 - Piperazine.  

Code of Federal Regulations, 2013 CFR

...diagnosis, treatment, and control of parasitism. (2) Turkeys â(i) Amount...diagnosis, treatment, and control of parasitism. (3) Swine â(i) Amount...diagnosis, treatment, and control of parasitism. [64 FR 23018, Apr. 29,...

2013-04-01

201

21 CFR 520.1807 - Piperazine.  

Code of Federal Regulations, 2010 CFR

...diagnosis, treatment, and control of parasitism. (2) Turkeys â(i) Amount...diagnosis, treatment, and control of parasitism. (3) Swine â(i) Amount...diagnosis, treatment, and control of parasitism. [64 FR 23018, Apr. 29,...

2009-04-01

202

In vitro and in vivo characterization of JNJ-31020028 ( N -(4-{4-[2-(diethylamino)-2-oxo-1-phenylethyl]piperazin-1-yl}-3-fluorophenyl)-2-pyridin-3-ylbenzamide), a selective brain penetrant small molecule antagonist of the neuropeptide Y Y 2 receptor  

Microsoft Academic Search

Rationale  The lack of potent, selective, brain penetrant Y2 receptor antagonists has hampered in vivo functional studies of this receptor.\\u000a \\u000a \\u000a \\u000a Objective  Here, we report the in vitro and in vivo characterization of JNJ-31020028 (N-(4-{4-[2-(diethylamino)-2-oxo-1-phenylethyl]piperazin-1-yl}-3-fluorophenyl)-2-pyridin-3-ylbenzamide), a novel Y2 receptor antagonist.\\u000a \\u000a \\u000a \\u000a Methods  The affinity of JNJ-31020028 was determined by inhibition of the PYY binding to human Y2 receptors in KAN-Ts cells and rat Y2 receptors

James R. Shoblock; Natalie Welty; Diane Nepomuceno; Brian Lord; Leah Aluisio; Ian Fraser; S. Timothy Motley; Steve W. Sutton; Kirsten Morton; Ruggero Galici; John R. Atack; Lisa Dvorak; Devin M. Swanson; Nicholas I. Carruthers; Curt Dvorak; Timothy W. Lovenberg; Pascal Bonaventure

2010-01-01

203

[3H]4-(Dimethylamino)-N-(4-(4-(2-Methoxyphenyl)Piperazin-1-yl)-Butyl)Benzamide: A Selective Radioligand for Dopamine D3 receptors. II. Quantitative Analysis of Dopamine D3 and D2 Receptor Density Ratio in the Caudate-Putamen  

PubMed Central

4-(Dimethylamino)-N-(4-(4-(2-methoxyphenyl)piperazin-1-yl)butyl)-benzamide (WC-10), a N-phenyl piperazine analog, displays high affinity and moderate selectivity for dopamine D3 receptors versus dopamine D2 receptors (Chu et al. [2005] Bioorg Med Chem 13:77–87). In this study, WC-10 was radiolabeled with tritium (specific activity = 80 Ci/mmol), and quantitative autoradiography studies were conducted using rhesus monkey and Sprague-Dawley rat brain sections. Kd values for the binding of [3H]WC-10 to D3 receptors obtained from quantitative autoradiography with rhesus monkey and rat brain sections are in agreement with Kd values obtained from cloned human and rat receptors (Xu et al. [2009] Synapse 63:717-728). The D2 selective antagonist [3H]raclopride binds with 11-fold higher affinity to human HEK D2L (Kd = 1.6 nM) than HEK D3 (Kd = 18 nM) receptors; [3H]raclopride binds to rat Sf9 rD2L receptors with a Kd of 6.79 nM, a value that is 4-fold lower than binding to human HEK D2L receptors and 2.5-fold higher than binding to rat Sf9 rD3 receptors. In vitro quantitative autoradiography studies with [3H]WC-10 and [3H]raclopride were conducted on adult rat and rhesus monkey brain sections. A mathematical model for calculating the absolute densities of dopamine D2 and D3 receptors based on the in vitro receptor binding data of [3H]WC-10 and [3H]raclopride was developed.

XU, JINBIN; HASSANZADEH, BABAK; CHU, WENHUA; TU, ZHUDE; JONES, LYNNE A.; LUEDTKE, ROBERT R.; PERLMUTTER, JOEL S.; MINTUN, MARK A.; MACH, ROBERT H.

2013-01-01

204

[3H]4-(Dimethylamino)-N-[4-(4-(2-methoxyphenyl)piperazin-1-yl)butyl]benzamide, a Selective Radioligand for Dopamine D3 receptors. II. Quantitative Analysis of Dopamine D3 and D2 Receptor Density Ratio in the Caudate-putamen  

PubMed Central

4-(Dimethylamino)-N-(4-(4-(2-methoxyphenyl)piperazin-1-yl)butyl)benzamide (WC-10), a N-phenyl piperazine analog, displays high affinity and moderate selectivity for dopamine D3 receptors versus dopamine D2 receptors (Chu et al. [2005] Bioorg. Med. Chem. 13; 77–87). In this study, WC-10 was radiolabeled with tritium (specific activity = 80 Ci/mmol) and quantitative autoradiography studies were conducted using rhesus monkey and Sprague-Dawley rat brain sections. Kd values for the binding of [3H]WC-10 to D3 receptors obtained from quantitative autoradiography with rhesus monkey and rat brain sections are in agreement with Kd values obtained from cloned human and rat receptors (Xu et al., 2009). The D2 selective antagonist [3H]raclopride binds with 11-fold higher affinity to human HEK D2L (Kd = 1.6 nM) than HEK D3 (Kd = 18 nM) receptors; and [3H]raclopride binds to rat Sf9 rD2L receptors with a Kd of 6.79 nM, a value that is 4-fold lower than binding to human HEK D2L receptors and 2.5-fold higher than binding to rat Sf9 rD3 receptors. In vitro quantitative autoradiography studies with [3H]WC-10 and [3H]raclopride were conducted on adult rat and rhesus monkey brain sections. A mathematical model for calculating the absolute densities of dopamine D2 and D3 receptors based on the in vitro receptor binding data of [3H]WC-10 and [3H]raclopride was developed.

Xu, Jinbin; Hassanzadeh, Babak; Chu, Wenhua; Tu, Zhude; Jones, Lynne A.; Luedtke, Robert R.; Perlmutter, Joel S.; Mintun, Mark A.; Mach, Robert H.

2009-01-01

205

Copper(II) complexation properties and surfactant activity of 3-[N, N-bis(2-hydroxyethyl)amino]-2-hydroxypropanesulfonic acid and N-(2-Hydroxyethyl)piperazine-N'-2-hydroxypropanesulfonic acid pH buffers which may affect trace metal speciation in in vitro studies.  

PubMed

Disadvantages of the some zwitterionic pH buffers are (i) that they can interact with metal ions as well as protons, and (ii) that they may have a surfactant effect in chemical or in vitro biological or biochemical studies. This has to be taken into account when a buffer is selected. Here, the copper-complexing capacity and the surfactant activity of three compounds, 3-[N,N-bis (2-hydroxyethyl)amino]-2-hydroxypropanesulfonic acid (DIPSO), N-(2-hydroxyethyl)piperazine-N'-(2-hydroxypropanesulfonic acid) (HEPPSO), and piperazine-N,N'-bis(2-ethanesulfonic acid) (Pipes), were investigated. Global stability constants (log betaabc) of copper(II)-buffer complexes were determined, at 25 degrees C, 0.5 M ionic strength, and at 0.8 mM buffer concentration, by pH and pCu ion-selective electrode measurements. Here, betaabc corresponds to the equilibrium: aCu2+ + bL- + cH+ left and right arrow (CuaLbHc)(2a-b+c); HL = DIPSO or HEPPSO; c: +1 = proton; -1 = hydroxide. Using SUPERQUAD constants were calculated, giving: DIPSO: log beta110 = 5.02, log beta120 = 8.99, log beta130 = 13.0, log beta140 = 16.3, log beta14-1 = 9.26, log beta14-2 = 0.645, log beta150 = 20.5, log beta160 = 24.3, log beta16-1 = 16.1, log beta16-2 = 8.98; HEPPSO: log beta110 = 4.29, log beta120 = 8.35, log beta130 = 12.1, log beta140 = 15.9, log beta150 = 19.6, log beta160 = 23.4, log beta16-1 = 14.9. The pKa values were determined at higher buffer concentrations, giving a value 7.33 for DIPSO and 7.84 for HEPPSO at 2.0 mM buffer concentration. Effects of buffer concentration on stability and acidity constants were investigated and compared with measurements using voltammetric and potentiometric stripping analysis, confirming no copper(II) complexation by Pipes. Surfactant activities were determined using alternating current polarography, confirming marked surface activity of 10 mM of DIPSO or HEPPSO. PMID:9882392

Vasconcelos, M T; Azenha, M A; Almeida, C M

1998-12-15

206

Patch testing with components of water-based metalworking fluids.  

PubMed

Water-based metalworking fluids (MWFs) may cause both irritant and allergic contact dermatitis. Several well-known MWF allergens are available for patch testing, but considering the wide variety of possible components used in MWF, our diagnostic arsenal covers only a small part of potential allergens. We therefore selected 13 frequently used MWF components that might be sensitizers and had not yet been tested routinely. In 5 centres, 233 dermatitis patients with present or past occupational exposure to MWF were patch tested with this and other panels. Only 7 patients showed positive reactions to the study panel. Allergic reactions to the emulsifier diglycolamine [syn. 2-(2-aminoethoxy) ethanol] were seen in 5 patients, and 1 patient each reacted positively to 2-amino-2-ethyl-1,3-propanediol (AEPD) and methyldiethanolamine (MDEA). Clinical relevance of the reactions to diglycolamine was unequivocally proven by its presence in the MWF from the patients' workplace in 3 cases. Diglycolamine seems to be an important MWF allergen, independently from monoethanolamine and diethanolamine. A test concentration of 1% petrolatum (pet.) appears to be appropriate. The importance of AEPD and MDEA as MWF allergens still remains to be established. The lack of positive test reactions to the other MWF components tested may be due to their low-sensitizing potential or too low a patch test concentration being used. PMID:14641356

Geier, Johannes; Lessmann, Holger; Frosch, Peter J; Pirker, Claudia; Koch, Patrick; Aschoff, Roland; Richter, Gerhard; Becker, Detlef; Eckert, Christian; Uter, Wolfgang; Schnuch, Axel; Fuchs, Thomas

2003-08-01

207

High-throughput sample preparation and simultaneous column regeneration liquid chromatography-tandem mass spectrometry method for determination of nitrogen mustard metabolites in human urine.  

PubMed

Nitrogen mustards (NMs) are known to have DNA alkylation and strong vesicant properties. Their availability to terrorist organizations makes them a potential choice for chemical attacks on civilian populations. After an exposure, it is difficult to measure NMs directly because of their rapid metabolism in the human body. Therefore to determine an individual's level of exposure to NMs, it is necessary to analyze for NM metabolites being excreted by the body. The metabolites of NMs are generated by a hydrolysis reaction, and are easily detectable by liquid chromatography tandem mass spectrometry (LC-MS/MS). This work is focused on the development of a high-throughput assay for the quantitation of N-ethyldiethanolamine (EDEA) and N-methyldiethanolamine (MDEA) metabolites of bis (2-chloroethyl) ethylethanamine (HN1) and bis (2-chloroethyl) methylethanamine (HN2), respectively. The method uses automated 96-well plate sample preparation of human urine samples and a 2-position 10-port switching valve to allow for simultaneous regeneration of the liquid chromatography (LC) columns. Using this method, over 18 h was saved through the reduction of sample preparation and analysis time when compared to a conventional method for 96 samples. The validated method provided excellent accuracy for both EDEA (100.9%) and MDEA (100.6%) with precision better than 5.27% for each analyte. PMID:21764395

Reddy, Muntha K; Mills, Grier; Nixon, Christopher; Wyatt, Shane A; Croley, Timothy R

2011-06-26

208

Diaqua-(5-carb-oxy-benzene-1,3-dicarboxyl-ato-?O 1)[8-ethyl-5-oxo-2-(piperazin-4-ium-1-yl)-5,8-dihydro-pyrido[2,3-d]pyrimidine-6-carboxyl-ato-?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.

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

2013-01-01

209

Diaqua-(5-carb-oxy-benzene-1,3-dicarboxyl-ato-?O(1))[8-ethyl-5-oxo-2-(piperazin-4-ium-1-yl)-5,8-dihydro-pyrido[2,3-d]pyrimidine-6-carboxyl-ato-?(2)O(5),O(6)]zinc monohydrate.  

PubMed

In the title compound, [Zn(C(14)H(17)N(5)O(3))(C(9)H(4)O(6))(H(2)O)(2)]·H(2)O, the complex mol-ecule exists in a zwitterionic form. The Zn(II) ion exhibits a distorted tetra-gonal-pyramidal geometry, being coordinated by two O atoms from the zwitterionic 8-ethyl-5-oxo-2-(piperazin-4-ium-1-yl)-5,8-dihydro-pyrido[2,3-d]pyrimidine-6-carboxyl-ate (L) ligand, one O atom from the 5-carb-oxy-benzene-1,3-dicarboxyl-ate 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 ?-? inter-actions 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

2013-01-31

210

21 CFR 520.2380f - Thiabendazole, piperazine phosphate powder.  

Code of Federal Regulations, 2013 CFR

...label shall bear the statement, âConsult your veterinarian for assistance in the diagonosis, treatment, and control of parasitism.â [46 FR 18963, Mar. 27, 1981, as amended at 46 FR 52330, Oct. 27, 1981; 62 FR 63271, Nov. 28,...

2013-04-01

211

21 CFR 520.1804 - Piperazine phosphate capsules.  

Code of Federal Regulations, 2013 CFR

...administer periodically as necessary. Consult your veterinarian for assistance in the diagnosis, treatment, and control of parasitism.1 [43 FR 6941, Feb. 17, 1978; 43 FR 9804, Mar. 10, 1978, as amended at 46 FR 20158, Apr. 3, 1981; 69 FR...

2013-04-01

212

21 CFR 520.2380d - Thiabendazole, piperazine citrate suspension.  

Code of Federal Regulations, 2013 CFR

...the rate of 1 fluid ounce of suspension per 100 pounds of body weight for the control of large strongyles, small strongyles, pinworms, Strongyloides and ascarids (including members of the genera Strongylus spp., Cyathostomum spp., Cylicobrachytus...

2013-04-01

213

Clean amine solvents economically and online  

SciTech Connect

Using electrodialysis technology to clean amine solvents is economically competitive with traditional change-out or ``bleed and feed`` methods, even for small systems, because a unit shutdown is not necessary to perform the process. Electrodialysis also has advantages over other online cleanup processes like ion exchange and vacuum reclamation. Off gases and olefinic and saturate liquefied petroleum gas (LPG) streams generated during operation of fluid catalytic crackers (FCC), cokers and other refinery processing equipment must be treated to remove undesirable components like hydrogen sulfide and carbon dioxide before they can be sold or used in downstream processes. At an Arkansas City, Kansas, refinery, a classic amine-based chemical absorbent system is used for this purpose. It comprises two absorbing contacts for gas and two for liquids. The system is charged with an N-methyldiethanolamine (MDEA)-based product that selectively absorbs contaminants. Amine is regenerated by removing contaminants with steam stripping. Lean amine is then recirculated to the absorbers. This case history demonstrates the effectiveness of electrodialysis technology for contaminant removal.

Price, J. [Total Petroleum, Arkansas City, KS (United States); Burns, D. [Union Carbide Corp., Houston, TX (United States)

1995-08-01

214

Self-assembled 3D heterometallic Cu(II)/Fe(II) coordination polymers with octahedral net skeletons: structural features, molecular magnetism, thermal and oxidation catalytic properties.  

PubMed

The new three-dimensional (3D) heterometallic Cu(II)/Fe(II) coordination polymers [Cu(6)(H(2)tea)(6)Fe(CN)(6)](n)(NO(3))(2n)·6nH(2)O (1) and [Cu(6)(Hmdea)(6)Fe(CN)(6)](n)(NO(3))(2n)·7nH(2)O (2) have been easily generated by aqueous-medium self-assembly reactions of copper(II) nitrate with triethanolamine or N-methyldiethanolamine (H(3)tea or H(2)mdea, respectively), in the presence of potassium ferricyanide and sodium hydroxide. They have been isolated as air-stable crystalline solids and fully characterized including by single-crystal X-ray diffraction analyses. The latter reveal the formation of 3D metal-organic frameworks that are constructed from the [Cu(2)(?-H(2)tea)(2)](2+) or [Cu(2)(?-Hmdea)(2)](2+) nodes and the octahedral [Fe(CN)(6)](4-) linkers, featuring regular (1) or distorted (2) octahedral net skeletons. Upon dehydration, both compounds show reversible escape and binding processes toward water or methanol molecules. Magnetic susceptibility measurements of 1 and 2 reveal strong antiferromagnetic [J = -199(1) cm(-1)] or strong ferromagnetic [J = +153(1) cm(-1)] couplings between the copper(II) ions through the ?-O-alkoxo atoms in 1 or 2, respectively. The differences in magnetic behavior are explained in terms of the dependence of the magnetic coupling constant on the Cu-O-Cu bridging angle. Compounds 1 and 2 also act as efficient catalyst precursors for the mild oxidation of cyclohexane by aqueous hydrogen peroxide to cyclohexanol and cyclohexanone (homogeneous catalytic system), leading to maximum total yields (based on cyclohexane) and turnover numbers (TONs) up to about 22% and 470, respectively. PMID:21028781

Karabach, Yauhen Y; Guedes da Silva, M Fátima C; Kopylovich, Maximilian N; Gil-Hernández, Beatriz; Sanchiz, Joaquin; Kirillov, Alexander M; Pombeiro, Armando J L

2010-10-28

215

21 CFR 520.1242c - Levamisole hydrochloride and piperazine dihydrochloride.  

Code of Federal Regulations, 2013 CFR

... (a) Specifications. (1) The drug is an aqueous solution which contains in each fluid ounce 0.36 gram...pinworms (Oxyuris equii ). (2) Limitations. Aqueous solution: administer by stomach tube or drench 1...

2013-04-01

216

21 CFR 520.2520g - Trichlorfon, phenothiazine, and piperazine dihydrochloride powder.  

Code of Federal Regulations, 2013 CFR

...Labeling shall bear the following statements: The drug is a cholinesterase inhibitor. Do not use this product in horses simultaneously...neuromuscular depolarizing agents (e.g., succinylcholine) or to cholinesterase-inhibiting drugs, pesticides, or chemicals....

2013-04-01

217

21 CFR 520.2520g - Trichlorfon, phenothiazine, and piperazine dihydrochloride powder.  

Code of Federal Regulations, 2010 CFR

...or within 2 weeks before or after treatment with, or exposure to, neuromuscular depolarizing agents (e.g., succinylcholine) or to cholinesterase-inhibiting drugs, pesticides, or chemicals. (d) Conditions of use â(1)...

2009-04-01

218

Design, synthesis and preliminary pharmacological evaluation of new piperidine and piperazine derivatives as cognition-enhancers  

Microsoft Academic Search

A series of 2-oxopiperazine, 4-aminomethyl-, 3-amino- and 3-aminomethylpiperidine analogues of DM235 (sunifiram) and MN19 (sapunifiram), two previously reported potent cognition-enhancers, have been synthesized and tested in the mouse passive-avoidance test. The compounds display minimal effective doses in the range 0.3–10mg\\/kg. Although the new substances do not show improved activity when compared to the parent compounds, some useful information has been

Elisabetta Martini; Carla Ghelardini; Silvia Dei; Luca Guandalini; Dina Manetti; Michele Melchiorre; Monica Norcini; Serena Scapecchi; Elisabetta Teodori; Maria Novella Romanelli

2008-01-01

219

Design, synthesis and preliminary pharmacological evaluation of new piperidine and piperazine derivatives as cognition-enhancers.  

PubMed

A series of 2-oxopiperazine, 4-aminomethyl-, 3-amino- and 3-aminomethylpiperidine analogues of DM235 (sunifiram) and MN19 (sapunifiram), two previously reported potent cognition-enhancers, have been synthesized and tested in the mouse passive-avoidance test. The compounds display minimal effective doses in the range 0.3-10mg/kg. Although the new substances do not show improved activity when compared to the parent compounds, some useful information has been obtained to understand structure-activity relationships. In addition, the 3-aminopiperidine moiety appears to be a promising scaffold to synthesize new drugs endowed with cognition-enhancing activity. PMID:17981042

Martini, Elisabetta; Ghelardini, Carla; Dei, Silvia; Guandalini, Luca; Manetti, Dina; Melchiorre, Michele; Norcini, Monica; Scapecchi, Serena; Teodori, Elisabetta; Romanelli, Maria Novella

2007-10-22

220

Piperazine-1,4-diium bis-(2,4,5-tricarb-oxy-benzoate) dihydrate.  

PubMed

In the title hydrated salt, C4H12N2 (2+)·2C10H5O8 (-)·2H2O, the piperazinediium cation, lying about an inversion center, adopts a chair conformation. The benzene ring of the anion makes dihedral angles of 25.17?(8)° with the carboxyl-ate group and angles of 8.50?(7), 20.07?(7) and 80.86?(8)° with the three carb-oxy-lic acid groups. In the crystal, the cations, anions and water mol-ecules are connected by O-H?O and N-H?O hydrogen bonds into double layers parallel to (110). PMID:23634109

Narayanam, Nagaraju; Gangu, Kranthi Kumar; Kurra, Balakrishna; Mukkamala, Saratchandra Babu

2013-03-23

221

Piperazine-1,4-diium bis-(2,4,5-tricarb-oxy-benzoate) dihydrate  

PubMed Central

In the title hydrated salt, C4H12N2 2+·2C10H5O8 ?·2H2O, the piperazinediium cation, lying about an inversion center, adopts a chair conformation. The benzene ring of the anion makes dihedral angles of 25.17?(8)° with the carboxyl­ate group and angles of 8.50?(7), 20.07?(7) and 80.86?(8)° with the three carb­oxy­lic acid groups. In the crystal, the cations, anions and water mol­ecules are connected by O—H?O and N—H?O hydrogen bonds into double layers parallel to (110).

Narayanam, Nagaraju; Gangu, Kranthi Kumar; Kurra, Balakrishna; Mukkamala, Saratchandra Babu

2013-01-01

222

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

Code of Federal Regulations, 2013 CFR

...per 500 pounds body weight; removal of large strongyles, pinworms, and bots, 1 bolus per 250 pounds body weight.1 (2...bots (Gastrophilus spp.), small strongyles, and pinworms (Oxyuris equi ).1 (3) Limitations....

2013-04-01

223

21 CFR 520.763c - Dithiazanine iodide and piperazine citrate suspension.  

Code of Federal Regulations, 2013 CFR

... For control of large roundworms, Parascaris equorum; small strongyles; large strongyles, Strongylus vulgaris; and pinworms, Oxyuris equi. (3) Limitations. Administer by drench or mixed with the daily ration as a single dose....

2013-04-01

224

2-{4-[(1,3-Benzodioxol-5-yl)meth-yl]piperazin-1-yl}pyrimidine  

PubMed Central

In the title compound, C16H18N4O2, known also as peribedil, the dihedral angle between the mean planes of the pyrimidine and benzene rings is 56.5?(8)°. The 1,3-dioxole fragment adopts an envelope conformation with the methyl­ene C atom forming the flap; this atom deviates by 0.232?(3)?Å from the plane defined by the remaining atoms of the 1,3-benzodioxole unit. In the crystal, C—H?? inter­actions between c-glide-related mol­ecules arrange them into columns extending along the c-axis direction. The columns related by a unit translation along the b axis are packed into (100) layers via another C—H?? inter­action involving the pyrimidine ring as an acceptor.

Wu, Chunli; Li, Jieming; Wei, Huijie; Hang, Ye; Jiang, Yueming

2013-01-01

225

LCMS\\/MS screening method for designer amphetamines, tryptamines, and piperazines in serum  

Microsoft Academic Search

Since the late 1990s and early 2000s, derivatives of well-known designer drugs as well as new psychoactive compounds have\\u000a been sold on the illicit drug market and have led to intoxications and fatalities. The LC-MS\\/MS screening method presented\\u000a covers 31 new designer drugs as well as cathinone, methcathinone, phencyclidine, and ketamine which were included to complete\\u000a the screening spectrum. All

Ariane Wohlfarth; Wolfgang Weinmann; Sebastian Dresen

2010-01-01

226

New analytical technique for carbon dioxide absorption solvents  

Microsoft Academic Search

The densities and refractive indices of two binary systems (water + MEA and water + MDEA) and three ternary systems (water + MEA + CO, water + MDEA + CO, and water + MEA + MDEA) used for carbon dioxide (CO) capture were measured over the range of compositions of the aqueous alkanolamine(s) used for CO absorption at temperatures from

Fatemeh Pouryousefi; Raphael O. Idem

2008-01-01

227

[Analysis of designer drugs detected in the products purchased in fiscal year 2006].  

PubMed

Many psychotropic substances are easily available in Japan via the Internet, thus the spread of drug abuse is becoming more serious problem. To avoid drug abuse, 32 substances have been controlled in Japan since April in 2007 by the Pharmaceutical Affairs Law as designated substances (Shitei-Yakubutsu, classified as 11 tryptamines, 11 phenethylamines, 2 piperazines, 6 alkyl nitrites, 1 diterpene and 1 plant). Although the distributions of these drugs have been decreased through this regulation, new designer drugs are still being found. In this study, we detected 7 designer drugs in 15 products, which purchased just before the amendment of the law, by NMR, GC-MS and LC-MS analyses. Three methylone derivertives (1-(3,4-methylenedioxyphenyl-2-(pyrrolidin-1-yl)-1-pentanone: MDPV, 2-methylamino-1-(3,4-methylenedioxyphenyl)butan-1-one: bk-MBDB, 2-ethylamino-1-(3,4-methylenedioxyphenyl)propan-1-one): bk-MDEA, a MDMA derivative (N-hydroxy-1-(3,4-methylenedioxyphenyl)-2-aminopropane: N-OH MDMA), a methamphetamine derivative (N-methyl-1-(4-fluorophenyl)propan-2-amine: N-Me-4-FMP), a tryptamine derivative (5-methoxy-N-ethyl-N-isopropyltryptamine: 5-MeO-EIPT) and indan-2-amine were detected. 5-MeO-EIPT was newly identified in this study. PMID:18827471

Uchiyama, Nahoko; Kikura-Hanajiri, Ruri; Kawahara, Nobuo; Goda, Yukihiro

2008-10-01

228

Synthesis and evaluation of 7-chloro-4-(piperazin-1-yl)quinoline-sulfonamide as hybrid antiprotozoal agents.  

PubMed

A new series of 4-aminochloroquinoline based sulfonamides were synthesized and evaluated for antiamoebic and antimalarial activities. Out of the eleven compounds evaluated (F1-F11), two of them (F3 and F10) showed good activity against Entamoeba histolytica (IC50 <5 ?M). Three of the compounds (F5, F7 and F8) also displayed antimalarial activity against the chloroquine-resistant (FCR-3) strain of Plasmodium falciparum with IC50 values of 2 ?M. Compound F7, whose crystal structure was also determined, inhibited ?-haematin formation more potently than quinine. To further understand the action of hybrid molecules F7 and F8, molecular docking was carried out against the homology model of P. falciparum enzyme dihydropteroate synthase (PfDHPS). The complexes showed that the inhibitors place themselves nicely into the active site of the enzyme and exhibit interaction energy which is in accordance with our activity profile data. Application of Lipinski 'rule of five' on all the compounds (F1-F11) suggested high drug likeness of F7 and F8, similar to quinine. PMID:23602620

Salahuddin, Attar; Inam, Afreen; van Zyl, Robyn L; Heslop, Donovan C; Chen, Chien-Teng; Avecilla, Fernando; Agarwal, Subhash M; Azam, Amir

2013-04-02

229

The Biological Properties of 3,6-Epidithiadiketo Piperazines Inhibition of Growth of Bacillus Subtilis by Gliotoxins, Sporidesmins, and Chetomin.  

National Technical Information Service (NTIS)

The ability of chetomin and the sporidesmin and gliotoxin groups of fungal metabolites to inhibit the growth of Bacillus subtilis (HLX 373) was examined. With the exception of gliotoxin dibenzoate, compounds having the 3,6-epidithiadiketopiperazine struct...

D. Brewer D. E. Hannah A. Taylor

1965-01-01

230

Head-to-tail assemblies of dipolar, piperazine-linked chromophores: Synthesis, x-ray structure, and dielectric characterization  

SciTech Connect

A dimer and a mixture of oligomers of acceptor-substituted anilines were prepared, either by Knoevenagel condensation of substituted cyanoacetylpiperazines with p-aminobenzaldehydes or by carbonyldiimidazole-promoted coupling of phenylpiperazines with p-aminocyanocinnamic acids. The resulting oligomeric amidopiperazines possess significantly additive molecular moments when in extended conformations and therefore are potentially valuable for the fabrication of polymer films containing electric field oriented chromophores, such as required for second-order nonlinear optics. The dimer is conformationally defined, and x-ray structural analysis of a model compound confirmed the stereochemistry and bond angles at the amide linkage. The enforced extended conformation of the dimer resulted in an enhanced dipole moment relative to the constituent monomers and raises the possibility of further enhancements in extended higher oligomers.

Katz, H.E.; Schilling, M.L. (AT T Bell Labs., Murray Hill, NJ (USA))

1989-09-13

231

Piperazine-1,4-diium (R)-2-[4-(1-car-boxy-l-atometh-oxy)phen-oxy]propano-ate.  

PubMed

In the anion of the title mol-ecular salt, C(4)H(12)N(2) (2+)·C(11)H(10)O(6) (2-), the two acetate groups form torsion angles of 74.1?(1) and 7.1?(1)° with the central benzene ring, and the cation exhibits a chair conformation. In the crystal, N-H?O hydrogen bonds link the components into a two-dimensional supra-molecular network lying parallel to the ab plane. A number of C-H?O inter-actions consolidate the packing. PMID:22798831

Ye, Han-Tao; Ren, Chang-Yue; Gao, Jin-Sheng

2012-06-20

232

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. The best solvent and process configuration, matrix with MDEA/PZ, offers 22% and 15% energy savings over the baseline and improved baseline, respectively, with stripping and compression to 10 MPa. The energy requirement for stripping and compression to 10 MPa is about 20% of the power output from a 500 MW power plant with 90% CO{sub 2} removal. The stripper rate model shows that a ''short and fat'' stripper requires 7 to 15% less equivalent work than a ''tall and skinny'' one. The stripper model was validated with data obtained from pilot plant experiments at the University of Texas with 5m K{sup +}/2.5m PZ and 6.4m K{sup +}/1.6m PZ under normal pressure and vacuum conditions using Flexipac AQ Style 20 structured packing. Experiments with oxidative degradation at low gas rates confirm the effects of Cu{sup +2} catalysis; in MEA/PZ solutions more formate and acetate is produced in the presence of Cu{sup +2}. At 150 C, the half life of 30% MEA with 0.4 moles CO{sub 2}/mole amine is about 2 weeks. At 100 C, less than 3% degradation occurred in two weeks. The solubility of potassium sulfate in MEA solution increases significantly with CO{sub 2} loading and decreases with MEA concentration. The base case corrosion rate in 5 M MEA/1,2M PZ is 22 mpy. With 1 wt% heat stable salt, the corrosion rate increases by 50% to 160% in the order: thiosulfate< oxalate

Gary T. Rochelle; Eric Chen; Babatunde Oyenekan; Andrew Sexton; Jason Davis; Marus Hiilliard; Qing Xu; David Van Wagener; Jorge M. Plaza

2006-12-31

233

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

Code of Federal Regulations, 2010 CFR

...Phencyclidine (number) (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....

2010-10-01

234

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

Code of Federal Regulations, 2010 CFR

...Phencyclidine (number) (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...

2010-10-01

235

Gas cleanup for indirect liquefaction  

Microsoft Academic Search

Visual aids are presented describing various classes of primary gas cleanup. These are: (1) amine systems (MDEA Process); (2) alkali salt systems; (3) physical absorption systems (Selexol Process, Stretford Process); (4) mixed solvent systems; and (5) Claus Sulfur Recovery System. Flowsheets are also presented for the MDEA, Selexol and Stretford processes.

Wham

1984-01-01

236

Gas cleanup for indirect liquefaction  

SciTech Connect

Visual aids are presented describing various classes of primary gas cleanup. These are: (1) amine systems (MDEA Process); (2) alkali salt systems; (3) physical absorption systems (Selexol Process, Stretford Process); (4) mixed solvent systems; and (5) Claus Sulfur Recovery System. Flowsheets are also presented for the MDEA, Selexol and Stretford processes.

Wham, R.M.

1984-08-01

237

Analysis of Ethanolamines: Validation of Semi-Volatile Analysis by HPLC-MS/MS by EPA Method MS888.  

National Technical Information Service (NTIS)

The Environmental Protection Agencys (EPA) Region 5 Chicago Regional Laboratory (CRL) developed a method titled Analysis of Diethanolamine, Triethanolamine, n- Methyldiethanolamine, and n-Ethyldiethanolamine in Water by Single Reaction Monitoring Liquid C...

A. Vu C. Koester J. Owens

2008-01-01

238

Discovery of 6-[4-(6-nitroxyhexanoyl)piperazin-1-yl)]-9H-purine, as pharmacological post-conditioning agent.  

PubMed

Novel purine analogues bearing nitrate esters were designed and synthesized in an effort to develop compounds triggering endogenous cardioprotective mechanisms such as ischemic preconditioning (IPC) or postconditioning (PostC). The majority of the compounds reduced infarct size compared to the control group in anesthetized rabbits, whereas administration of the most active analogue 16 at a dose of 3.8 ?mol/kg resulted on a significant reduction of infarct size, compared to PostC group (13.4 ± 1.9% vs 26.4 ± 2.3%). These findings introduce a novel class of promising pharmacological compounds that could be used as mimics or enhancers of PostC. PMID:22925446

Koufaki, Maria; Fotopoulou, Theano; Iliodromitis, Efstathios K; Bibli, Sophia-Iris; Zoga, Anastasia; Kremastinos, Dimitrios Th; Andreadou, Ioanna

2012-07-31

239

Acute Oral Toxicity Evaluations of Some Zinc(II) Complexes Derived from 1-(2-Salicylaldiminoethyl)piperazine Schiff Bases in Rats  

PubMed Central

The current study described the synthesis and the in vivo acute oral toxicity evaluations in Sprague Dawley rats. The compounds were characterized by elemental analyses, LC-MS, FTIR, 1H NMR, 13C NMR and UV-visible spectroscopy. In the acute toxicity study, a single administration of the compounds was performed orally to the rats at the single doses of 2000 mg/kg and they were then monitored for possible side effects, mortality or behavioral changes up to 14 days. The serum level of aspartate (AST), alanine aminotransferases (ALT), alkaline phosphate (ALP), triglyceride, high density lipoprotein (HDL), immunoglobulins (GAM) and the C-reactive proteins did not significantly change. The hematological indices white blood cells (WBC), haematocrit (HCT), red blood cells (RBC), mean corpuscular volume (MCV), mean corpuscular haemoglobin concentration (MCHC), and mean corpuscular hemoglobin (MCH) were within the normal range. The renal function indices examined were also within the reference range. Generally, the compounds exhibited low toxic effects as required for further in vivo therapeutic studies.

Salga, Muhammad Saleh; Ali, Hapipah Mohd; Abdulla, Mahmood Ameen; Abdelwahab, Siddig Ibrahim

2012-01-01

240

1-Cyclohexyl-4-(4-arylcyclohexyl)piperazines: Mixed ? and human ?(8)-?(7) sterol isomerase ligands with antiproliferative and P-glycoprotein inhibitory activity.  

PubMed

Many new chemotherapeutic agents are under preclinical investigation and, despite efforts to more selectively target cancer cells, limitations such as toxicity and inherent resistance are often encountered. Therefore, alternative strategies are needed to treat cancer and overcome such limitations. We describe novel cyclohexylpiperazine derivatives, designed as mixed affinity ligands for sigma (?) receptors and human ??-?? sterol isomerase (HSI) ligands, which also exhibit P-glycoprotein (P-gp) inhibitory activity, with the aim of exploiting the antiproliferative effects mediated by ? and HSI sites while overcoming P-gp-mediated resistance. All of the compounds displayed high affinities for ? receptors and HSI sites, P-gp inhibitory activity, and ?? receptor agonist antiproliferative activity. Antiproliferative activity was also tested in PC-3 cells to establish ?? and HSI contribution. Compound cis-11, which displayed the best antiproliferative and P-gp inhibitory activities, was co-administered with 0.1??M doxorubicin in MDCK-MDR1 cells. Compound cis-11 caused 70?% and 90?% cell death when co-administered at 30??M and 50??m, respectively. When administered alone, cis-11 resulted in 50?% cell death, demonstrating its single agent antitumor properties in a tumor cell line overexpressing P-gp. PMID:21069657

Abate, Carmen; Niso, Mauro; Contino, Marialessandra; Colabufo, Nicola Antonio; Ferorelli, Savina; Perrone, Roberto; Berardi, Francesco

2011-01-01

241

1-Ethyl-6-fluoro-7-(4-methyl-piperazin-4-ium-1-yl)-4-oxo-1,4-dihydroquinoline-3-carboxylate hexa-hydrate.  

PubMed

In the title compound, C(17)H(20)FN(3)O(3)·6H(2)O, the pefloxacin (pef) neutral zwitterion is accompanied by six water mol-ecules of hydration. An extensive network of O-H?O and N-H?O hydrogen bonds help to establish the crystal packing. PMID:21201468

An, Zhe; Liang, Qing-Cheng

2008-01-16

242

Synthesis, antibacterial and antitubercular activities of some 7-[4-(5-amino-[1,3,4]thiadiazole-2-sulfonyl)-piperazin-1-yl] fluoroquinolonic derivatives  

Microsoft Academic Search

In the present study, a series of 7-[4-(5-amino-1,3,4 thiadiazole-2-sulfonyl)]-1-piperazinyl fluoroquinolonic derivatives VIIa–d were synthesized in good yields and characterized by IR, 1H-NMR, 13C-NMR, FAB Mass spectral and elemental analyses. The compounds were evaluated for their preliminary in vitro antibacterial activity against some Gram-positive and Gram-negative bacteria and selected compounds VIIa, b were screened for antitubercular activity against Mycobacterium tuberculosis H37Rv

S. Talath; A. K. Gadad

2006-01-01

243

Direct organocatalytic coupling of carboxylated piperazine-2,5-diones with indoles through conjugate addition of carbon nucleophiles to indolenine intermediates  

PubMed Central

The indole–diketopiperazine bridge is an important structural feature of many bispyrrolidinoindoline and epipolythiodiketopiperazine fungal metabolites. Organocatalytic conjugate addition of diketopiperazines to indoles was achieved in good to excellent yields through electrophilic indolenine intermediates generated under mild conditions. Screening of catalysts and solvents at different temperatures was performed in order to achieve high product yields.

Dubey, Ramin; Olenyuk, Bogdan

2009-01-01

244

Generation of initial stepping pattern of a biped robot with modular dynamic encoding algorithm for searches  

NASA Astrophysics Data System (ADS)

In this paper, a modified version of dynamic encoding algorithm for searches (DEAS) is proposed and applied to generate walking patterns of a biped humanoid robot. For the controller of each joint motor to generate optimal trajectories, mDEAS is developed from the previous versions of exhaustive DEAS (eDEAS) and univariate DEAS (uDEAS). Modular DEAS (mDEAS) searches optimal coefficients of polynomials whose trajectories are assigned to joint motors. Since the number of the coefficients amounts up to 16, sharing search space and optimizing independently is expected to search efficiently. For validation of mDEAS, a simulation result about initial stepping is provided.

Kim, Taegyu; Kim, Jong-Wook

2007-12-01

245

21 CFR 178.3130 - Antistatic and/or anti-fogging agents in food-packaging materials.  

Code of Federal Regulations, 2010 CFR

...2-hydroxyethyl)piperazine, as determined by paper chromatography method For use only:1. As an antistatic...2-hydroxyethyl) piperazine, as determined by paper chromatography method For use only as an antistatic...

2009-04-01

246

21 CFR 178.3130 - Antistatic and/or anti-fogging agents in food-packaging materials.  

Code of Federal Regulations, 2010 CFR

...2-hydroxyethyl)piperazine, as determined by paper chromatography method For use only:1. As an antistatic...2-hydroxyethyl) piperazine, as determined by paper chromatography method For use only as an antistatic...

2010-01-01

247

Synthesis of Novel New 2-(2-(4-((3,4Dihydro4-oxo-3-aryl quinazolin-2-yl)methyl)piperazin-1-yl)acetoyloxy)-2-phenyl Acetic Acid Esters  

Microsoft Academic Search

Stereoselective diazotization of (S)-2-amino-2-phenyl acetic acid (L-phenyl glycine) (4) with NaNO2 in 6% H2SO4 in a mixture of acetone and water gave optically pure (S)-2-hydroxy-2-phenyl acetic acid (L-mandelic acid) (5). Esterification, gave (S)-2-hydroxy-2-phenyl acetic acid esters (6). The latter was treated with chloroacetyl chloride in the presence of triethylamine (TEA) in dichloromethane (DCM) to yield (S)-2-chloroacetyloxy phenyl acetic acid ester

Palle V. R. Acharyulu; P. K. Dubey; P. V. V. Prasada Reddy; Thatipally Suresh

2009-01-01

248

Discovery of a novel sub-class of ROMK channel inhibitors typified by 5-(2-(4-(2-(4-(1H-Tetrazol-1-yl)phenyl)acetyl)piperazin-1-yl)ethyl)isobenzofuran-1(3H)-one.  

PubMed

A sub-class of distinct small molecule ROMK inhibitors were developed from the original lead 1. Medicinal chemistry endeavors led to novel ROMK inhibitors with good ROMK functional potency and improved hERG selectivity. Two of the described ROMK inhibitors were characterized for the first in vivo proof-of-concept biology studies, and results from an acute rat diuresis model confirmed the hypothesis that ROMK inhibitors represent new mechanism diuretic and natriuretic agents. PMID:24075732

Tang, Haifeng; de Jesus, Reynald K; Walsh, Shawn P; Zhu, Yuping; Yan, Yan; Priest, Birgit T; Swensen, Andrew M; Alonso-Galicia, Magdalena; Felix, John P; Brochu, Richard M; Bailey, Timothy; Thomas-Fowlkes, Brande; Zhou, Xiaoyan; Pai, Lee-Yuh; Hampton, Caryn; Hernandez, Melba; Owens, Karen; Roy, Sophie; Kaczorowski, Gregory J; Yang, Lihu; Garcia, Maria L; Pasternak, Alexander

2013-09-06

249

Evidence for the sequential formation of two complexes between an uptake inhibitor, GBR 12783 [1-[2-(diphenylmethoxy)ethyl]-4-(3-phenyl-2-propenyl)piperazine], and the neuronal transporter of dopamine.  

PubMed

Incubation of a crude synaptosomal fraction from rat striatum with GBR 12783 at 37 degrees C produced an inhibition of the specific uptake of [3H]dopamine that increased with time. The inhibition increased when GBR 12783 was present during preincubation and incubation (IC50 = 1.85+/-0.1 nM) instead of incubation alone (IC50 = 25+/-3.5 nM). Time-course studies of uptake inhibition demonstrated that a first collision transporter-inhibitor complex (TI) was formed immediately after addition of GBR 12783 so that the initial uptake velocity (V0) decreased for increasing concentrations of inhibitor (Ki > or = 20 nM). TI slowly isomerized to a more stable complex TI* (Ki* < or = 5 nM) with a value of t1/2 = 20-270 s. Fits of data to model 2 in which the steady-state uptake (VS) is set to zero were generally preferred, suggesting that formation of TI* could tend to irreversibility, as a consequence of a very low reverse isomerization. As expected, k, V0, and VS tended to steady-state values in an asymptotic manner for high concentrations of GBR 12783. GBR 12783 at 2.5 nM produced a mixed inhibition of the uptake, with an increase in KM and a decrease in Vmax; these effects were improved for 10 nM GBR 12783 and at 20 degrees C. These results are discussed in relation to previous data concerning [3H]GBR 12783 binding. The present work gives the first experimental demonstration that dopamine uptake blockers can act according to a two-step mechanism of inhibition; this is of great interest, because these inhibitors can oppose the effects of cocaine or amphetamine on the transporter according to a reaction that is partly nondependent on the concentration of the abused agent. PMID:9886093

Do-Régo, J C; Hue, H; Costentin, J; Bonnet, J J

1999-01-01

250

4-(1-Cyclo-propyl-6-fluoro-4-oxo-1,4-dihydro-quinolin-7-yl)piperazin-1-ium 2,4,5-tricarb-oxy-benzene-1-carboxyl-ate monohydrate  

PubMed Central

In the crystal of title compound, C16H19FN3O+·C10H5O8 ?·H2O, the water mol­ecule and the ions are connected by inter­molecular N—H?O and O—H?O hydrogen bonds and ?–? stacking [centroid–centroid separation = 3.602?(1)?Å] between the benzene ring and the pyridine ring, generating a three-dimensional supra­molecular structure.

Yan, Shi-Wei; Liang, Yan-Chen; Liao, Qin; Xin, Guang-Hua; Ye, Zhong-Li

2012-01-01

251

4-(1-Cyclo-propyl-6-fluoro-4-oxo-1,4-dihydro-quinolin-7-yl)piperazin-1-ium 2,4,5-tricarb-oxy-benzene-1-carboxyl-ate monohydrate.  

PubMed

In the crystal of title compound, C(16)H(19)FN(3)O(+)·C(10)H(5)O(8) (-)·H(2)O, the water mol-ecule and the ions are connected by inter-molecular N-H?O and O-H?O hydrogen bonds and ?-? stacking [centroid-centroid separation = 3.602?(1)?Å] between the benzene ring and the pyridine ring, generating a three-dimensional supra-molecular structure. PMID:22412762

Yan, Shi-Wei; Liang, Yan-Chen; Liao, Qin; Xin, Guang-Hua; Ye, Zhong-Li

2012-02-29

252

Rapid room temperature synthesis of electrocatalytically active Au nanostructures  

Microsoft Academic Search

We describe a facile route for the one-pot room temperature synthesis of anisotropic Au nanostructures in aqueous solution in the absence of seeds or surfactants and their electrocatalytic activity. The Au nanostructures were synthesized using piperazine derivatives 1-(2-hydroxyethyl)piperazine and 1,4-Bis(2-hydroxyethyl)piperazine as reducing agents. The Au nanostructures were characterized by spectral, transmission electron microscopic (TEM), X-ray diffraction and electrochemical measurements. The

Ashok Kumar Das; C. Retna Raj

2011-01-01

253

Studies on the metabolism and the toxicological analysis of the nootropic drug fipexide in rat urine using gas chromatography–mass spectrometry  

Microsoft Academic Search

Qualitative studies are described on the metabolism and the toxicological analysis of the nootropic fipexide (FIP) in rat urine using gas chromatography–mass spectrometry (GC–MS). FIP was extensively metabolized to 1-(3,4-methylenedioxybenzyl)piperazine (MDBP), 4-chlorophenoxyacetic acid, 1-[2-(4-chlorophenoxy)acetyl]piperazine, N-(4-hydroxy-3-methoxy-benzyl)piperazine, piperazine, N-(3,4-methylenedioxybenzyl)ethylenediamine, and N-[2-(4-chlorophenoxy)acetyl]ethylenediamine. The authors’ systematic toxicological analysis (STA) procedure using full-scan GC–MS after acid hydrolysis of one urine aliquot, liquid-liquid extraction and acetylation

Roland F. Staack; Hans H. Maurer

2004-01-01

254

H Sub 2 S-Removal Processes for Low-Btu Coal Gas.  

National Technical Information Service (NTIS)

Process descriptions are provided for seven methods of removing H sub 2 S from a low-Btu coal-derived gas. The processes include MDEA, Benfield, Selexol, Sulfinol, Stretford, MERC Iron Oxide, and Molecular Sieve. Each of these processes was selected as re...

M. S. Edwards

1979-01-01

255

Integration of GC\\/EI-MS and GC\\/NCI-MS for simultaneous quantitative determination of opiates, amphetamines, MDMA, ketamine, and metabolites in human hair  

Microsoft Academic Search

In this paper, the possibility of using a multiple ionization mode approach of GC\\/MS was developed for the simultaneous hair testing of common drugs of abuse in Asia, including amphetamines (amphetamine, AP; methamphetamine, MA; methylenedioxy amphetamine, MDA; methylenedioxy methamphetamine, MDMA; methylenedioxy ethylamphetamine, MDEA), ketamine (ketamine, K; norketamine, NK), and opiates (morphine, MOR; codeine, COD; 6-acetylmorphine, 6-AM). This strategy integrated the

Ya-Hsueh Wu; Keh-liang Lin; Su-Chin Chen; Yan-Zin Chang

2008-01-01

256

Development of carbon dioxide separation process using continuous hollow-fiber membrane contactor and water-splitting electrodialysis  

Microsoft Academic Search

Studies on the development of carbon dioxide (CO2) separation process using continuous hollow-fiber membrane contactor (HFMC) and water-splitting electrodialysis (WSED) as an alternative method for the conventional processes are reported. Several experiments for CO2 recovery and absorbent regeneration using HFMC–WSED hybrid system were performed. In this study, four widely used absorbents (KOH, NaOH, K2CO3, and N-methyldiethanolamine) were examined and compared

Moon-Sung Kang; Seung-Hyeon Moon; You-In Park; Kew-Ho Lee

2002-01-01

257

Enhanced detectability of fluorinated derivatives of N, N-dialkylamino alcohols and precursors of nitrogen mustards by gas chromatography coupled to Fourier transform infrared spectroscopy analysis for verification of chemical weapons convention  

Microsoft Academic Search

N,N-Dialkylamino alcohols, N-methyldiethanolamine, N-ethyldiethanolamine and triethanolamine are the precursors of VX type nerve agents and three different nitrogen mustards respectively. Their detection and identification is of paramount importance for verification analysis of chemical weapons convention. GC–FTIR is used as complimentary technique to GC–MS analysis for identification of these analytes. One constraint of GC–FTIR, its low sensitivity, was overcome by converting

Prabhat Garg; Ajay Purohit; Vijay K. Tak; D. K. Dubey

2009-01-01

258

Analysis of Ethanolamines: Validation of Semi-Volatile Analysis by HPLC-MS\\/MS by EPA Method MS888  

Microsoft Academic Search

The Environmental Protection Agency's (EPA) Region 5 Chicago Regional Laboratory (CRL) developed a method titled 'Analysis of Diethanolamine, Triethanolamine, n-Methyldiethanolamine, and n-Ethyldiethanolamine in Water by Single Reaction Monitoring Liquid Chromatography\\/Tandem Mass Spectrometry (LC\\/MS\\/MS): EPA Method MS888'. This draft standard operating procedure (SOP) was distributed to multiple EPA laboratories and to Lawrence Livermore National Laboratory, which was tasked to serve as

J Owens; A Vu; C Koester

2008-01-01

259

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

260

Synthesis, spectral, magnetic, electrochemical and kinetic studies of copper(II), nickel(II) and zinc(II) acetate complexes derived from phenol based ‘end-off’ ligands: Effect of p-substituents  

Microsoft Academic Search

A new class of symmetric, end-off, N-methyl piperazine armed binucleating ligands 2,6-bis(4-methyl piperazin-1-yl-methyl)-4-acetyl phenol (HL1) and 2,6-bis[(4-methyl piperazin-1-yl-methyl)]-(4-methylcarboxy) phenol (HL2) were synthesized by the Mannich reaction. Their mononuclear and binuclear Cu(II), Ni(II) and Zn(II) complexes have been synthesized. These complexes were characterized by elemental analysis, infra-red and electronic spectral analysis. In the electronic spectra, the lower electron withdrawing nature of

K. Shanmuga Bharathi; S. Sreedaran; A. Kalilur Rahiman; K. Rajesh; V. Narayanan

2007-01-01

261

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

262

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.

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

2012-01-01

263

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

264

Nitrolysis of the CN Single Bond and Related Chemistry of Nitro and Nitroso Groups.  

National Technical Information Service (NTIS)

Contents: Nitrosolysis of Tertiary Amines: Piperidines, Piperazines, Bisdimethylaminoalkanes and Functionalized Methyldialkylamines; 1,2-Dinitrocyclohexene: Nitration of 4-Nitro-N,N-dimethylbenzylamine - Formation of 2-Methyl-6-nitroindazole; The Formatio...

J. H. Boyer

1987-01-01

265

Synthesis of Perfluoro Highly Branched Heterocyclic Fluorine Compounds by Direct Fluorination. (Reannouncement with New Availability Information).  

National Technical Information Service (NTIS)

The direct fluorination of hexamethyleneimine, heptamethyleneimine, 2,6-dimethylmorpholine, thiomorpholine, 1,4-dimethylpiperazine and piperazine produced the corresponding perfluorinated products. The 19F NMR spectrum of perfluoro N,N1 - difluoropiperazi...

W. H. Lin R. J. Lagow

1990-01-01

266

ANTHELMINTIC ACTIVITY OF LEAVES OF JUSTICIA BEDDOMEI  

PubMed Central

Ethanolic and Chloroform extract of leaves of Justicia beddomei were evaluated separately for anthelmintic activity on adult Indian earthworms Pheretima posthuma, using Piperazine citrate as reference standard. The results indicated that ethanolic extract was more potent than the chloroform extract

Srinivasa, U.; Rao, J. Venkateshwara; Krupanidhi, A.M.; Shanmukhappa, S.

2007-01-01

267

Acta Poloniae Pharmaceutica. Volume 26, Number 3, 1969.  

National Technical Information Service (NTIS)

Contents: Synthesis of some piperidyl esters of acetyltropic and diphenylacetic acids; Alkylation of 4-acyl-4-phenylpiperidines; Synthesis of 2-aminoethyl-hydrazine and some of its derivatives; gamma-(N-2-pyridono)-propyl-piperazines substituted at positi...

1969-01-01

268

Evidence that hypophagia induced by m CPP and TFMPP requires 5HT 1C and 5HT 1B receptors; hypophagia induced by RU 24969 only requires 5HT 1B receptors  

Microsoft Academic Search

Male Sprague-Dawley rats deprived of food for 18 h were injected with the 5-HT agonists RU 24969, 1-(3-chlorophenyl)piperazine\\u000a (mCPP) or 1-[3-(trifluoromethyl)phenyl)]piperazine (TFMPP) and 20 min later presented with their normal diet. Food intake was\\u000a determined 1, 2 and 4 h later. All three drugs reduced intake over 1 and 2 h. Three out of four drugs with high affinity for

G. A. Kennett; G. Curzon

1988-01-01

269

Probing the "additive effect" in the proline and proline hydroxamic acid catalyzed asymmetric addition of nitroalkanes to cyclic enones.  

PubMed

The effect of chirality and steric bulk of 2,5-disubstituted piperazines as additives in the conjugate addition of 2-nitropropane to cyclohexenone, catalyzed by l-proline, was investigated. Neither chirality nor steric bulk affects the enantioselectivity of addition, which gives 86-93% ee in the presence of achiral and chiral nonracemic 2,5-disubstituted piperazines. Proline hydroxamic acid is shown for the first time to be an effective organocatalyst in the same Michael reaction. PMID:16189834

Hanessian, Stephen; Govindan, Subramaniyan; Warrier, Jayakumar S

2005-11-01

270

Effective eradication of pinworms ( Syphacia muris, Syphacia obvelata and Aspiculuris tetraptera ) from a rodent breeding colony by oral anthelmintic therapy  

Microsoft Academic Search

Summary An oral combination of piperazine and ivermectin was used over a 6-week period for treating three different colonies of mice or rats infested with Syphacia obvelata, Syphacia muris or Aspiculuris tetraptera. No acute toxic effect was found in transgenic lines of mice or rats with these products in a preliminary trial. The colonies were treated with piperazine, 2.1 mg\\/ml

Lionel Zenner

1998-01-01

271

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

272

An integration of the multi-component DEA and GAR models to the measurement of hotel performance  

Microsoft Academic Search

The aim of this paper is to identify how well each hotel performs in each of its room and food and beverage divisions. To this end, this paper develops a multi-component data envelopment analysis\\/global assurance region (MDEA\\/GAR) model to fully gauge hotel performance where each hotel has its specific inputs and outputs for both divisions as well as shared inputs

Ming-Miin Yu

2012-01-01

273

An integration of the multi-component DEA and GAR models to the measurement of hotel performance  

Microsoft Academic Search

The aim of this paper is to identify how well each hotel performs in each of its room and food and beverage divisions. To this end, this paper develops a multi-component data envelopment analysis\\/global assurance region (MDEA\\/GAR) model to fully gauge hotel performance where each hotel has its specific inputs and outputs for both divisions as well as shared inputs

Ming-Miin Yu

2011-01-01

274

Psychogene Amphetamine (,,Ecstasy``)  

Microsoft Academic Search

\\u000a Summary   The term ``ecstasy'' comprises many different hallucinogenic amphetamines, of which the most prominent representatives are\\u000a MDMA (3,4-methylenedioxy-methamphetamine) and MDEA (3,4-methylenedioxyethamphetamine). Apart from these and related active\\u000a substances there are additional substances to be found in the offered preparations (e. g., amphetamine, ephedrine, selegiline,\\u000a paracetamol), which can modify the effect and the symptoms of ecstasy to a great extent. In

O. Sauer; L. S. Weilemann

1997-01-01

275

A study on the carbon dioxide recovery from 2 ton-CO 2\\/day pilot plant at LNG based power plant  

Microsoft Academic Search

A pilot plant of 2ton-CO2\\/day for CO2 recovery from flue gas emitted from 250MW LNG based power plant was tested with aqueous absorbents. The absorbent tested were of different nature such as primary amine (MEA), blend of primary, secondary, tertiary and sterically hindered amine such as MDEA+HMDA, AEPD+DPTA, and TIPA+DPTA. We have studied the CO2 recovery as function of temperature,

Seungmoon Lee; Sanjeev Maken; Jin-Won Park; Ho-Jun Song; Jong Jin Park; Jae-Goo Shim; Jun-Han Kim; Hee-Moon Eum

2008-01-01

276

Study of engineering ceramic machining with a new design of ripple controlled microdetonation of electrode arc striking  

Microsoft Academic Search

Based on the principle of strong shock wave generating transient dynamic high-pressure, physical theory of vacuum discharge,\\u000a and high-power pulse technology, this study developed a new machining system of ripple controlled microdetonation of electrode\\u000a arc striking (MDEAS), which was specially used to machine hard and crisp materials, such as ceramic. The topographies such\\u000a as hole, ladder plane, column surface, and

Xinli Tian; Junfei Yang; Chao Liu; Baoguo Zhang; Fang Guo; Aibing Yu

2010-01-01

277

Quinoxaline derivatives as photoinitiators in UV-cured coatings  

Microsoft Academic Search

Photopolymerization of multifunctional acrylates with a series of quinoxaline derivatives as photoinitiator with N-methyldiethanol amine (MDEA) has been investigated by real-time Fourier transform infrared spectroscopy (RT-FTIR). The formulations were also coated onto tracing paper and cured by using Mini-UV-Cure unit. Curing was assessed until no visible deformation was observed. MEK resistance of films was also determined.

Demet Karaca Balta; Sevnur Keskin; Feyza Karasu; Nergis Arsu

2007-01-01

278

HâS-removal processes for low-Btu coal gas  

Microsoft Academic Search

Process descriptions are provided for seven methods of removing HâS from a low-Btu coal-derived gas. The processes include MDEA, Benfield, Selexol, Sulfinol, Stretford, MERC Iron Oxide, and Molecular Sieve. Each of these processes was selected as representing a particular category of gas treating (e.g., physical solvent systems). The open literature contains over 50 processes for HâS removal, of which 35

1979-01-01

279

A comparative study on the carbon dioxide capture power between 30 wt% 2-amino-2-methyl-1-propanol and 30 wt% methyldiethanol amine aqueous solutions  

Microsoft Academic Search

A comparative study has been performed to compare the 30 wt% of 2-amino-2-methyl-1-propanol (AMP) aqueous solution and 30\\u000a wt% of methyldiethanol amine (MDEA) aqueous solution to capture carbon dioxide contained in the flue gas stream. The equilibrium\\u000a constants for each electrolyte reactions have been used to estimate the carbon dioxide absorption process. Henry’s constants\\u000a for each binary pairs between solute

Byung Don Lee; Dong Min Kim; Jungho Cho; Sang Wook Park

2009-01-01

280

Enantiomeric analysis of drugs of abuse in wastewater by chiral liquid chromatography coupled with tandem mass spectrometry  

Microsoft Academic Search

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

Barbara Kasprzyk-Hordern; Vishnu V. R. Kondakal; David R. Baker

2010-01-01

281

New analytical technique for carbon dioxide absorption solvents  

SciTech Connect

The densities and refractive indices of two binary systems (water + MEA and water + MDEA) and three ternary systems (water + MEA + CO{sub 2}, water + MDEA + CO{sub 2}, and water + MEA + MDEA) used for carbon dioxide (CO{sub 2}) capture were measured over the range of compositions of the aqueous alkanolamine(s) used for CO{sub 2} absorption at temperatures from 295 to 338 K. Experimental densities were modeled empirically, while the experimental refractive indices were modeled using well-established models from the known values of their pure-component densities and refractive indices. The density and Gladstone-Dale refractive index models were then used to obtain the compositions of unknown samples of the binary and ternary systems by simultaneous solution of the density and refractive index equations. The results from this technique have been compared with HPLC (high-performance liquid chromatography) results, while a third independent technique (acid-base titration) was used to verify the results. The results show that the systems' compositions obtained from the simple and easy-to-use refractive index/density technique were very comparable to the expensive and laborious HPLC/titration techniques, suggesting that the refractive index/density technique can be used to replace existing methods for analysis of fresh or nondegraded, CO{sub 2}-loaded, single and mixed alkanolamine solutions.

Pouryousefi, F.; Idem, R.O. [University of Regina, Regina, SK (Canada). Faculty of Engineering

2008-02-15

282

Solubility of carbon dioxide in aqueous solutions of 2-amino-2-methyl-1,3-propanediol  

SciTech Connect

The equilibrium solubility of carbon dioxide in aqueous solutions of 2-amino-2-methyl-1,3-propanediol (AMPD) has been measured at (30, 40, and 60) C and the partial pressure of carbon dioxide ranging from (0.5 to 3065) kPa. The concentrations of the aqueous solutions were (10 and 30) mass % AMPD. The tendency of the solubility of carbon dioxide in 30 mass % AMPD aqueous solution at 40 C was found to be similar to that in 30 mass % N-methyldiethanolamine aqueous solution.

Baek, J.I.; Yoon, J.H. [Korea Electric Power Research Inst., Taejon (Korea, Republic of). Center for advanced Studies in Energy and the Environment

1998-07-01

283

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

284

Metabolism of designer drugs of abuse.  

PubMed

Abuse of designer drugs is widespread among young people, especially in the so-called "dance club scene" or "rave scene", worldwide. Severe and even fatal poisonings have been attributed to the consumption of such drugs of abuse. However, in contrast to new medicaments, which are extensively studied in controlled clinical studies concerning metabolism, including cytochrome P450 isoenzyme differentiation, and further pharmacokinetics, designer drugs are consumed without any safety testing. This paper reviews the metabolism of new designer drugs of abuse that have emerged on the black market during the last years. Para-methoxyamphetamine (PMA), para-methoxymethamphetamine (PMMA) and 4-methylthioamphetamine (4-MTA), were taken into consideration as new "classical" amphetamine-derived designer drugs. Furthermore, N-benzylpiperazine (BZP), 1-(3, 4-methylenedioxybenzyl)piperazine (MDBP), 1-(3-trifluoromethylphenyl)piperazine (TFMPP), 1-(3-chlorophenyl)piperazine (mCPP) and 1-(4-methoxyphenyl)piperazine (MeOPP) were taken into consideration as derivatives of the class of piperazine-derived designer drugs, as well as alpha-pyr-rolidinopropiophenone (PPP), 4'-methoxy-alpha-pyrrolidinopropiophenone (MOPPP), 3', 4'-methylenedioxy-alpha-pyrrolidino-propiophenone (MDPPP), 4'-methyl-alpha-pyrrolidinopropiophenone (MPPP), and 4'-methyl-alpha-pyrrolidinoexanophenone (MPHP) as derivatives of the class of alpha-pyrrolidinophenone-derived designer drugs. Papers describing identification of in vivo or in vitro human or animal metabolites and cytochrome P450 isoenzyme dependent metabolism have been considered and summarized. PMID:15975043

Staack, Roland F; Maurer, Hans H

2005-06-01

285

Mutagenicity of products generated by the reaction between several antiparasitic drugs and nitrite  

SciTech Connect

Drugs containing secondary aliphatic amines, heterocyclic nitrogen, or secondary aliphatic amido groups (chloroquine, dehydroemetine, mebendazole, and piperazine) and pyrimidine derivatives such as pyrantel pamoate were reacted in vitro with sodium nitrite at pH 3.7 and became mutagenic for Salmonella typhimurium strain TA1535. The products derived from the nitrosation of chloroquine and dehydroemetine required metabolic activation by mammalian hepatic S9 to be mutagenic. The N-nitroso derivatives of mebendazole, piperazine, and pyrantel pamoate were mutagenic with and without S9, although more activity was noted in the presence of S9 with the nitrosated compounds formed from mebendazole and piperazine. Under identical conditions, no mutagenic products were detected from quaternary ammonium salts such as bephenium hydroxynaphthoate or drugs containing tertiary heterocyclic amino groups, such as iodochlorhydroxyquin.

Alba, M.A.; Espinose, J.; Cortinas de Nava, C.

1988-01-01

286

An evaluation of levamisole for treatment of ascariasis.  

PubMed

Levamisole (Decaris, Belgium) was tested in Iran, Brazil, and in Mississippi and Louisiana for its efficacy as a single-dose oral treatment for Ascaris infections. Subjects were children ages 2 to 15 years, and numbers treated with levamisole and comparative anthelmintics are as follows: 453 with levamisole; 461 with piperazine citrate; 17 with pyrantel pamoate; and 19 with a placebo. Cure rates and total reduction in mean egg counts observed were 92% and 98% respectively for levamisole and 66% and 90% for piperazine. Sixteen of 17 treated with pyrantel pamoate were cured. In none of the drugs were there notable side reactions, but in all four studies side effects were more frequent with piperazine than with levamisole. Levamisole was found to be a well-tolerated, highly effective single-dose ascaricide. It should prove to be particularly useful for mass chemotherapy in Ascaris control programs. PMID:341337

Miller, M J; Farahmandian, I; Arfaa, F; Katz, N; Winsor, E; Bennett, E

1978-02-01

287

Degradable poly(amidoamine) hydrogels as scaffolds for in vitro culturing of peripheral nervous system cells.  

PubMed

This paper reports on the synthesis and physico-chemical, mechanical, and biological characterization of two sets of poly(amidoamine) (PAA) hydrogels with potential as scaffolds for in vivo peripheral nerve regeneration. They are obtained by polyaddition of piperazine with N,N'-methylenebis(acrylamide) or 1,4-bis(acryloyl)piperazine with 1,2-diaminoethane as cross-linking agent and exhibit a combination of relevant properties, such as mechanical strength, biocompatibility, biodegradability, ability to induce adhesion and proliferation of Schwann cells (SCs) preserving their viability. Moreover, the most promising hydrogels, that is those deriving from 1,4-bis(acryloyl)piperazine, allow the in vitro growth of the sensitive neurons of the dorsal root ganglia, thus getting around a critical point in the design of conduits for nerve regeneration. PMID:23239646

Mauro, Nicolò; Manfredi, Amedea; Ranucci, Elisabetta; Procacci, Patrizia; Laus, Michele; Antonioli, Diego; Mantovani, Cristina; Magnaghi, Valerio; Ferruti, Paolo

2012-12-13

288

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. Gas chromatography has been used to measure the oxidative degradation of piperazine. The heat exchangers for the pilot plant have been received. The modifications are on schedule for start-up in November 2003.

Gary T. Rochelle; Eric Chen; J. Tim Cullinane; Marcus Hilliard; Babatunde Oyenekan; Terraun Jones

2003-07-28

289

ORGANIC SELENIUM COMPOUNDS. PART I: SYNTHESIS AND APPLICATION OF SOME NEW DIARYL-SELENIDES AND SELENONES CONTAINING AMINO ACID MOIETIES  

Microsoft Academic Search

4?-Nitro-4-aminodiphenylselenide (1) reacts with chloroacetyl chloride giving 4?-nitro-4-chloroacetylaminodiphenylselenide (2) which undergo facile reaction with certain amines and hydrazine yielding 4?-glycylamino and hydrazinoacetylamino-4?-nitrodiphenylse lenides (3) and (5). Two moles of (2) react with one mole of piperazine and\\/or hydrazine to give 1,4-bis [p-N-(p?-nitro-diphenylselenido)aminocarbonylmethylene] piperazine (4) and 1,2-bis[p-N-(p?-nitro-diphenylselenido)aminocarbonyl-methylene]hydrazine (6). Condensation of (5) with aromatic aldehydes in the presence of glacial acetic acid

M. A. Abbady; Sh. H. Abdel-Hafez

2000-01-01

290

Triprotic acid-base microequilibria and pharmacokinetic sequelae of cetirizine.  

PubMed

(1)H NMR-pH titrations of cetirizine, the widely used antihistamine and four related compounds were carried out and the related 11 macroscopic protonation constants were determined. The interactivity parameter between the two piperazine amine groups was obtained from two symmetric piperazine derivatives. Combining these two types of datasets, all the 12 microconstants and derived tautomeric constants of cetirizine were calculated. Upon this basis, the conflicting literature data of cetirizine microspeciation were clarified, and the pharmacokinetic absorption-distribution properties could be interpreted. The pH-dependent distribution of the microspecies is provided. PMID:19491022

Marosi, Attila; Kovács, Zsuzsanna; Béni, Szabolcs; Kökösi, József; Noszál, Béla

2009-03-14

291

Spectroscopic studies on proton transfer equilibria: 2,4-dinitrophenol with several electron donors  

NASA Astrophysics Data System (ADS)

The proton transfer equilibria of 2,4-dintrophenol with triethylamine, 1,4-diazabicyclo(2,2,2)octane, piperazine, N,N-dimethyl piperazine, N-methylacetamide, N,N-dimethylacetamide, N,N-dimethyl formamide and dimethyl sulfoxide have been studied in cyclohexane/carbon tetrachloride and benzene solvents by electronic absorption spectroscopy. Thermodynamic parameters for the proton transfer equilibria have been determined. It is shown that the extent of interaction between 2,4-dinitrophenol and the aprotic solvent determines the position of equilibrium.

Murthy, A. S. N.; Reddy, A. Ram

292

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

293

De novo design of a picomolar nonbasic 5-HT(1B) receptor antagonist.  

PubMed

We describe herein the discovery of novel, de novo designed, 5-HT(1B) receptor antagonists that lack a basic moiety and that provide improved hERG and in vitro phospholipidosis profiles. We used a known 5-HT(1B) antagonist template as our starting point and focused on replacing the piperazine moiety. Pyrazole-based ideas were designed and synthesized among a small library of piperazine replacements. To our knowledge, these are the first potent, nonbasic, functionally active antagonists of the 5-HT(1B) receptor. PMID:20088516

Nugiel, David A; Krumrine, Jennifer R; Hill, Daniel C; Damewood, James R; Bernstein, Peter R; Sobotka-Briner, Cynthia D; Liu, Jianwei; Zacco, Anna; Pierson, M Edward

2010-02-25

294

A new GC-MS method for the determination of five amphetamines in human hair.  

PubMed

A new gas chromatography-mass spectrometry method for the simultaneous identification and quantitation of amphetamine (AP), methamphetamine (MA), 3,4-methylenedioxyamphetamine (MDA), 3,4-methylenedioxymethamphetamine (MDMA), and 3,4-methylenedioxyethamphetamine (MDEA) in hair is proposed. Hair was hydrolyzed in 1 M NaOH at 40 degrees C, subjected to extraction with 4:1 (v/v) methylene chloride/isopropanol, and derivatized with pentafluoropropionic anhydride (PFPA) and ethyl acetate. Calibration curves for the five analytes were constructed over the concentration range 0.5-25.0 ng/mg, using their pentadeuterated analogues as internal standards. The limits of detection and quantitation obtained were 0.045 and 0.151 ng/mg for AP; 0.014 and 0.048 ng/mg for MA; 0.013 and 0.043 ng/mg for MDA; 0.017 and 0.057 ng/mg for MDMA; and 0.007 and 0.023 ng/mg for MDEA. The accuracy of the method was found to be in the range +/- 9%, and the coefficients of variation were less than 8%. Overall, 24 hair specimens tested positive for one or more amphetamines, with average concentrations of 0.88 ng/mg for AP, 10.14 ng/mg for MA, 1.30 ng/mg for MDA, and 8.87 ng/mg for MDMA. Only one specimen tested positive for MDEA with a concentration of 0.84 ng/mg. PMID:15902982

Villamor, J L; Bermejo, A M; Fernández, P; Tabernero, M J

2005-03-01

295

A solvent system to provide selective removal of sulfur compounds  

SciTech Connect

Energy costs and SRU inefficiencies resulting from utilization of low strength MEA technology induced a large refinery to convert to MDEA. One of the seven product streams being treated required extremely low carbonyl sulfide in the treated product. This required careful consideration in making the decision to convert. However, the conclusions were that the advantages outweighed the disadvantages. When the initial converted operations verified a need to improve the carbonyl sulfide removal, GAS/SPEC Tech Service produced an innovative solution which allowed for efficient operation at acceptable COS specification, lower energy utilization, reduced solvent losses, and improved sulfur recovery unit operation.

Pearce, R.L.; Bacon, T.R.

1986-01-01

296

Improved sulfur removal processes evaluated for IGCC  

SciTech Connect

An inherent advantage of Integrated Coal Gasification Combined Cycle (IGCC) electric power generation is the ability to easily remove and recover sulfur. During the last several years, a number of new, improved sulfur removal and recovery processes have been commercialized. An assessment is given of alternative sulfur removal processes for IGCC based on the Texaco coal gasifier. The Selexol acid gas removal system, Claus sulfur recovery, and SCOT tail gas treating are currently used in Texaco-based IGCC. Other processes considered are: Purisol, Sulfinol-M, Selefning, 50% MDEA, Sulften, and LO-CAT. 2 tables.

Not Available

1986-12-01

297

GC?MS Determination of Amphetamines in Human Urine  

Microsoft Academic Search

An analytical method for the simultaneous determination of amphetamine (AP), methamphetamine (MA), 3,4?methylenedioxyamphetamine (MDA), 3,4?methylenedioxy?methamphetamine (MDMA), and 3,4?methylenedioxy?ethamphetamine (MDEA) in urine, using gas chromatography–mass spectrometry (GC–MS), is proposed. The analytes were subjected to liquid–liquid extraction with 4?1 (v\\/v) methylene chloride\\/isopropanol at pH 12, and derivatized with pentafluoropropionic anhydride (PFPA) and ethyl acetate. Calibration curves for the five analytes in methanol

J. L. Villamor; A. M. Bermejo; P. Fernández; M. J. Tabernero

2005-01-01

298

Selective absorption of so/sub 2/ from gases containing the same  

SciTech Connect

There is disclosed a process for selectively removing and recovering sulfur dioxide from a gas stream containing the same by contacting the gas with an absorbent (an aqueous solution of a piperazine, piperazinone or a morpholinone) and thermally regenerating the absorbent (i.e. releasing the sulfur dioxide from the absorbent) for reuse in the contacting step.

Jones, M. B.; Fowler, A. E.

1985-07-23

299

Synthesis and Characterization of Potential Dimers of Gatifloxacin - an Antibacterial Drug  

PubMed Central

Gatifloxacin is an antibacterial agent belonging to the fourth-generation fluoroquinolone family. Four piperazine-linked fluoroquinolone dimers of Gatifloxacin were observed during the laboratory process for Gatifloxacin and they were identified. The present work describes the origin, synthesis, characterization, and control of these dimers along with the synthesis of Despropylene Gatifloxacin (metabolite).

Garaga, Srinivas; Raghava Reddy, Ambati V.; Prabahar, Koilpillai Joseph; Korupolu, Raghu Babu; Sanasi, Paul Douglas

2013-01-01

300

The new analogues of nitrogen mustard with one, two or three 2-chloroethylamino fragments. Reactions with nucleophiles.  

PubMed

1,3,5-Triazines substituted with mono-, di, and tri-[4-(2-chloroethyl)piperazin-l-yl] groups gave products of substitution of chlorine atom when treated with ethanol, phenol, butylamine, toluidine,or thiophenol under mild reaction conditions. PMID:19172853

Kolesi?ska, Beata; Drozdowska, Danuta; Kami?ski, Zbigniew J

301

In vitro anthelmintic activity of Melia azedarach naturalized in Argentina.  

PubMed

The anthelmintic activity of the drupe extracts of Melia azedarach L. (Meliaceae) growing in Argentina was tested against tapeworms, hookworms, nodular worms and earthworms, and was shown to be better than the standards piperazine phosphate and hexylresorcinol against tapeworms and hookworms, respectively. PMID:16941610

Szewczuk, Víctor D; Mongelli, Elena R; Pomilio, Alicia B

2006-11-01

302

Anthelmintic tests on Toxocara canis infection in mice  

Microsoft Academic Search

One hundred and forty mice were infected orally with 1000 embryonated Toxocara canis eggs. Groups of 10 mice were then treated with high doses of piperazine, mebendazole, oxfendazole, albendazole, fenbendazole and diethylcarbamazine for four days, either immediately after infection or three weeks after infection. The mice were killed three to six weeks after treatment and the number of larvae in

PE Holt; MJ Clarkson; M Kerslake

1981-01-01

303

Eradication of the pinworm Syphacia obvelata from an animal unit by anthelmintic therapy  

Microsoft Academic Search

Summary Thiabendazole incorporated in the diet at a rate of 0·1%, fed to all animals over a period of 3 months, successfully eliminated the parasite from the colony. Samples taken 12 months after treatment were still negative for the parasite. During the period between the discovery of the organism and the preparation of the diet a course of piperazine citrate

Dawn Owen; Jon A. Turton

1979-01-01

304

CO2 Capture by Absorption with Potassium Carbonate Second Quarterly Report 2006. (Report for April 1, 2006-June 30, 2006).  

National Technical Information Service (NTIS)

The objective of this work is to improve the process for CO2 capture by alkanolamine absorption/stripping by developing an alternative solvent, aqueous K2CO3 promoted by piperazine. The pilot plant data have been reconciled using 17% inlet CO2. A rate-bas...

G. T. Rochelle E. Chen B. Oyenekan A. Sexton J. Davis

2006-01-01

305

CO (sub 2) Capture by Absorption with Potassium Carbonate First Quarterly Report 2006.  

National Technical Information Service (NTIS)

The objective of this work is to improve the process for CO2 capture by alkanolamine absorption/stripping by developing an alternative solvent, aqueous K2CO3 promoted by piperazine. The final campaign of the pilot plant was completed in February 2006 with...

2006-01-01

306

Trimetazidine Protects against Smoking-Induced Left Ventricular Remodeling via Attenuating Oxidative Stress, Apoptosis, and Inflammation  

Microsoft Academic Search

Trimetazidine, a piperazine derivative used as an anti-anginal agent, improves myocardial glucose utilization through inhibition of fatty acid metabolism. The present study was designed to investigate whether trimetazidine has the protective effects against smoking-induced left ventricular remodeling in rats. In this study, Wistar rats were randomly divided into 3 groups: smoking group (exposed to cigarette smoke), trimetazidine group (exposed to

Xiang Zhou; Chao Li; Weiting Xu; Jianchang Chen

2012-01-01

307

Application of solvent microextraction to the analysis of amphetamines and phencyclidine in urine.  

PubMed

A fast and simple method to detect some commonly abused illicit drugs, amphetamine, methamphetamine, 3,4-methylendioxy-amphetamine (MDA), 3,4-methylendioxy-methamphetamine (MDMA), 3,4-methylendioxy-N-ethylamphetamine (MDEA) and phencyclidine (PCP) in urine using solvent microextraction (SME) combined with gas chromatography (GC) analysis has been developed. The extraction is conducted by suspending a 2 microl drop of chloroform in a 2 ml urine sample. Following 8 min of extraction, the organic solvent is withdrawn into the syringe and injected into a GC with a pulsed discharge helium ionization detector (PDHID). The effects of different extraction solvents and times, pH and sample preparation were studied. The optimized method was capable of detecting drugs in urine at concentrations below Substance Abuse and Mental Health Services Administration (SAMHSA) established cut-off values for preliminary testing. Good linearity and reproducibility of extraction were obtained. The limits of detection were 0.5 microg/ml for amphetamine, 0.1 microg/ml for methamphetamine and MDA, 0.05 microg/ml for MDMA, 0.025 microg/ml for MDEA and 0.015 microg/ml for PCP. Relative standard deviation (R.S.D.) values ranged between 5 and 20% for the studied drugs. PMID:11473798

Casari, C; Andrews, A R

2001-09-01

308

Screening for illicit drugs on Euro banknotes by LC-MS/MS.  

PubMed

A method for the simultaneous quantification of illicit drugs on Euro banknotes, using an ultra-performance liquid chromatography tandem mass spectrometry, was developed and validated. The method included cocaine, benzoylecgonine, MDMA, MDEA, MDA, methamphetamine, diacetylmorphine, 6-MAM, morphine and ?(9)-THC. Drug residues were monitored and quantified via positive ESI mode using multiple reaction monitoring. Banknotes were extracted with methanol by vigorous shaking. Recovery rates were in the range of 60-80%. Calibration was performed with spiked banknotes in the range of 10-100 ng/note (R(2) 0.98-0.99). Intra-day analysis showed fair precision and accuracy (? 15%). Matrix effects were in the range from 27% to 235%. 7-15 samples of each denomination were analyzed. The calculated median values per note were 106 ng cocaine, 43 ng benzoylecgonine, 41 ng heroin, 15.5 ng 6-MAM, 16.5 ng morphine, 9 ng MDMA and 7 ng methamphetamine. ?(9)-THC was detected on 4 banknotes. MDEA and MDA were not detected on any note. A widespread background contamination for cocaine and opiates was demonstrated. PMID:20810225

Wimmer, Kurt; Schneider, Serge

2010-09-01

309

Hydrogen sulfide selectivity with carbonyl sulfide removal to less than PPM levels  

SciTech Connect

Changes in market conditions and plant operating economics require examination of traditional processes and operating practices in gas treating applications for upgrading to more stringent standards of efficiency in order to remain competitive while returning a satisfactory operating profit margin to the company. Anticipated reduction in solvent usage, improvements in Claus sulfur recovery unit performance and lower energy costs induced Ashland's Catlettsburg refinery to convert its entire sulfur removal system from monoethanolamine to methyldiethanolamine. One of the seven product streams being treated required extremely low carbonyl sulfide specifications. When the initial converted operations evidenced a need to improve the carbonyl sulfide removal, GAS/SPEC Tech Service produced an innovative solution which allowed for efficient operation which still achieved these objectives.

Bacon, T.R.; Pearce, R.L.; Foster, W.R. Jr.

1986-01-01

310

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

2012-01-11

311

Integration of GC/EI-MS and GC/NCI-MS for simultaneous quantitative determination of opiates, amphetamines, MDMA, ketamine, and metabolites in human hair.  

PubMed

In this paper, the possibility of using a multiple ionization mode approach of GC/MS was developed for the simultaneous hair testing of common drugs of abuse in Asia, including amphetamines (amphetamine, AP; methamphetamine, MA; methylenedioxy amphetamine, MDA; methylenedioxy methamphetamine, MDMA; methylenedioxy ethylamphetamine, MDEA), ketamine (ketamine, K; norketamine, NK), and opiates (morphine, MOR; codeine, COD; 6-acetylmorphine, 6-AM). This strategy integrated the characteristics of gas chromatography-mass spectrometry (GC-MS) using electron impact ionization (EI) and negative chemical ionization (NCI). Hair samples (25 mg) were washed, cut, and incubated overnight at 25 degrees C in methanol-trifluoroacetic acid (methanol-TFA). The samples were extracted by solid phase extraction (SPE) procedure, derivatized using heptafluorobutyric acid anhydride (HFBA) at 70 degrees C for 30 min, and the derivatives analyzed by GC-MS with EI and NCI. The limit of detection (LOD) with GC/EI-MS analysis obtained were 0.03 ng/mg for AP, MA, MDA, MDMA, and MDEA; 0.05 ng/mg for K, NK, MOR, and COD; and 0.08 ng/mg for 6-AM. The LOD of GC/NCI-MS analysis was much lower than GC/EI-MS analysis. The LOD obtained were 30 pg/mg for AP and MDA in GC/EI-MS and 2 pg/mg in GC/NCI-MS. Therefore, the sensitivity of AP and MDA in GC/NCI-MS was improved from 15-fold compared with EI. The sensitivity of AP, MA, MDA, MDMA, MDEA, MOR, and COD was improved from 15- to 60-fold compared with EI. In addition, the sensitivity of 6-AM increased 8-fold through selection of m/z 197 for the quantitative ion. Moreover, K and NK could dramatically improve their sensitivity at 200- and 2000-fold. The integration of GC/EI-MS and GC/NCI-MS can obtain the high sensitivity and complementary results of drugs of abuse in hair. Six hair samples from known drug abusers were examined by this new strategy. These results show that integrating the characteristics of GC/EI-MS and GC/NCI-MS were not only enhancement of the sensitivity but also avoid wrong results and wrong interpretations of correct results. PMID:18585989

Wu, Ya-Hsueh; Lin, Keh-Liang; Chen, Su-Chin; Chang, Yan-Zin

2008-06-17

312

Synthesis and structure-activity relationship of di-(3, 8-diazabicyclo[3.2.1]octane) diquaternary ammonium salts as unique analgesics.  

PubMed

Based on the structure characteristics of the lead compounds, 1, 1' octanedioyl-4, 4'-dimethyl-4, 4'-dibenzyl dipiperazinium dibromide (2) and 3, 8-disubstituted-3, 8-diazabicyclo [3.2.1]octanes (DBO), di-(3, 8-diazabicyclo [3.2.1]octane) diquaternary ammonium salts 3 a-c were designed and synthesized through a highly practical procedure. Target compounds 3 a-c and the hydrochloride salts of their precursors 10 a-c were evaluated for their in vivo analgesic and sedative activities. Interestingly, the introduction of an endoethylenic bridge in the piperazine of lead compound 2 causes loss of the analgesic activity and increases the toxicity dramatically. This result shows that the flexible conformation of piperazine in compound 2 is favorable for interaction with the receptor, and the quaternization of compounds 10 a-c is the main reason for the toxicity increase. PMID:14639743

Liu, Hong; Cheng, Tie-Ming; Zhang, Hong-Mei; Li, Run-Tao

2003-11-01

313

Efficient N-arylation/dealkylation of electron deficient heteroaryl chlorides and bicyclic tertiary amines under microwave irradiation.  

PubMed

A highly efficient procedure was developed for the microwave-assisted synthesis of N-heteroaryl-4-(2-chloroethyl)piperazines and N-heteroaryl-4-(2-chloroethyl)piperidines. Microwave irradiation of electron deficient heteroaryl chlorides with 1,4-diazabicyclo[2.2.2]octane (DABCO) at 160 degrees C for 15 min led to N-heteroaryl-4-(2-chloroethyl)piperazines in good to excellent yields. In a similar manner, microwave irradiation of electron deficient heteroaryl chlorides with quinuclidine at 180 degrees C for 15 min provided N-heteroaryl-4-(2-chloroethyl)piperidines in good to excellent yields. Extension of the method was demonstrated by the development of a one-pot, two-step microwave-assisted protocol for the synthesis of 4-(2-acetoxyethyl)-substituted N-heteroarylpiperazines and N-heteroarylpiperidines to demonstrate the production of a small library in a parallel fashion. PMID:19301850

Wang, Hong-Jun; Wang, Yi; Csakai, Adam J; Earley, William G; Herr, R Jason

314

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. CO{sub 2} mass transfer rates are second order in piperazine concentration and increase with ionic strength. Modeling of stripper performance suggests that 5 m K{sup +}/2.5 m PZ will require 25 to 46% less heat than 7 m MEA. The first pilot plant campaign was completed on June 24. The CO{sub 2} penetration through the absorber with 20 feet of Flexipac{trademark} 1Y varied from 0.6 to 16% as the inlet CO{sub 2} varied from 3 to 12% CO{sub 2} and the gas rate varied from 0.5 to 3 kg/m{sup 2}-s.

Gary T. Rochelle; Eric Chen; J.Tim Cullinane; Marcus Hilliard; Jennifer Lu; Babatunde Oyenekan; Ross Dugas

2004-07-29

315

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. The final campaign of the pilot plant was completed in February 2006 with 5m K{sup +}/2.5m PZ and 6.4m K{sup +}/1.6m PZ using Flexipac AQ Style 20. The new cross-exchanger reduced the approach temperature to less than 9 C. Stripper modeling has demonstrated that a configuration with a ''Flashing Feed'' requires 6% less work that a simple stripper. The oxidative degradation of piperazine proceeds more slowly than that of monoethanolamine and produces ethylenediamine and other products. Uninhibited 5 m KHCO{sub 3}/2.5 m PZ corrodes 5 to 6 times faster that 30% MEA with 0.2 mol CO{sub 2}/mol MEA.

Gary T. Rochelle; Eric Chen; Babatunde Oyenekan; Andrew Sexton; Amorvadee Veawab

2006-04-28

316

Synthesis and in vitro pharmacological evaluation of indolyl carboxylic amide analogues as D3 dopamine receptor selective ligands†  

PubMed Central

A series of substituted 1H-indolyl carboxylic acid amides that contain a N-(2-methoxyphenyl)piperazine or N-(2-fluoroethoxy)piperazine group were synthesized and their affinities for human dopamine D2, D3, and D4 receptors were determined. Two of these compounds, 14a and 14b, displayed high binding affinity at D3 (Ki = 0.18 and 0.4 nM, respectively), and selectivity for D3 vs. D2 receptors (87-fold and 60-fold, respectively). These two compounds had low binding affinity at D4 receptors and ? receptor sites. The intrinsic activity of these compounds at D2 and D3 receptors was determined using a forskolin-dependent adenylyl cyclase inhibition assay; both 14a and 14b were found to be partial agonists. Furthermore, for compound 14a, the log D value of 2.85 suggested it has suitable lipophilicity for crossing the blood–brain-barrier.

Tu, Zhude; Li, Shihong; Li, Aixiao; Taylor, Michelle; Ho, David; Malik, Maninder; Luedtke, Robert R.

2013-01-01

317

Flunarizinium hydrogen maleate  

PubMed Central

In the cation of the title salt {systematic name: 4-[bis­(4-fluoro­phen­yl)meth­yl]-1-[(2E)-3-phenyl­prop-2-en-1-yl]piperazin-1-ium hydrogen maleate}, C26H27F2N2 +·C4H3O4 ?, the protonated piperazine ring is in a chair conformation. The dihedral angle between the 4-fluoro­phenyl rings is 68.2?(2)°. An intra­molecular O—H?O hydrogen bond occurs in the anion. In the crystal, N—H?O, C—H?O and C—H?F inter­actions are observed, which link the ions into [001] chains.

Kavitha, Channappa N.; Jasinski, Jerry P.; Matar, Somer M.; Yathirajan, H. S.; Ramesha, A. R.

2013-01-01

318

CO{sub 2} 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. Thermodynamic modeling predicts that the heat of desorption of CO{sub 2} from 5m K+/2.5 PZ from 85 kJ/mole at 40 C to 30 kJ/mole at 120 C. Mass transfer modeling of this solvent suggests that carbonate and general salt concentration play a major role in catalyzing the rate of reaction of CO{sub 2} with piperazine. Stripper modeling suggests that with the multipressure stripper, the energy consumption with a generic solvent decreases by 15% as the heat of desorption is decreased from 23.8 to 18.5 kcal/gmol. A second pilot plant campaign with 5m K+/2.5 PZ was successfully completed.

Gary T. Rochelle; J.Tim Cullinane; Marcus Hilliard; Eric Chen; Babatunde Oyenekan; Ross Dugas

2005-01-31

319

Cinnarizinium fumarate  

PubMed Central

In the title salt {systematic name: 4-diphenyl­methyl-1-[(E)-3-phenyl­prop-2-en-1-yl]piperazin-1-ium (2Z)-3-carb­oxy­prop-2-enoate}, C26H29N2 +·C4H3O4 ?, the piperazine ring in the cation adopts a distorted chair conformation and contains a positively charged N atom with quaternary character. The dihedral angle between the mean planes of the phenyl rings of the diphenyl­methyl group is 74.2?(7)° and those between these rings and the phenyl ring of the 3-phenyl­prop-2-en-1-yl group are 12.7?(9) and 80.6?(8)°. In the crystal, N—H?O and O—H?O hydrogen bonds form chains along [001]. Weak C—H?O inter­actions connect parallel chains along [010], forming layers perpendicular to the a-axis direction.

Kavitha, C. N.; Yildirim, Sema Ozturk; Jasinski, Jerry P.; Yathirajan, H. S.; Butcher, Ray J.

2013-01-01

320

Synthesis, antimicrobial testing and QSAR study of new 2-phenylethenylbenzothiazolium salts substituted by cyclic amines.  

PubMed

A series of new 2-phenylethenylbenzothiazolium salts substituted by cyclic amines has been prepared by the condensation of 2-methyl benzothiazolium bromide with substituted benzaldehydes. The nucleophilic substitution of 4-fluorobenzaldehyde with appropriate cyclic amines has been used to obtain the starting benzaldehydes. The compounds with saturated cycloamino substituents have shown enhanced activity against Euglena and some derivatives with piperazine substituent were active against Gram positive bacteria. PMID:11125994

Magdolen, P; Zahradník, P; Foltínová, P

2000-11-01

321

Infusion of the 5-hydroxytryptamine agonists RU24969 and TFMPP into the paraventricular nucleus of the hypothalamus causes hypophagia  

Microsoft Academic Search

The 5-HT1B agonist RU24969 when given either systemically (1 mg\\/kg SC) or by infusion (0.5, 1.0, 2.0 µg) into the region of the paraventricular nucleus of the hypothalamus caused dose-dependent hypophagia in rats previously deprived of food for 18 h. Similar results were obtained at the above dosages of 1-[3-(trifluoromethyl) phenyl] piperazine (TFMPP), which acts on 5-HT1B and possibly also

P. H. Hutson; T. P. Donohoe; G. Curzon

1988-01-01

322

Dissociation constants and thermodynamic properties of amines and alkanolamines from (293 to 353) K  

Microsoft Academic Search

The dissociation constants of protonated 2-amino-2-ethyl-1,3-propanediol, 2-amino-2-methyl-1-propanol, diethylmonoethanolamine, diisopropanolamine, dimethylmonoethanolamine, monoethanolamine, 1-amino- 2-propanol, methylmonoethanolamine, triethanolamine, and the first and the second dissociation constants of piperazine and hydroxyethylpiperazine have been determined by electromotive force measurements from (293 to 353) K. The dissociation constants of protonated triethylamine have been determined with the same technique from (293 to 333) K. The experimental results

G. F. Versteeg; E. S. Hamborg

2009-01-01

323

Are 5HT1A Autoreceptors Involved in the Inhibitory Effect of Ipsapirone on Cold-Elicited Thyrotropin Secretion?  

Microsoft Academic Search

Administration of the serotonin (5-HT)1a receptor agonist ipsapirone has been shown to decrease cold-elicited thyrotropin (TSH) secretion. We have analyzed (1) the influence of 5-HT1a receptors and ipsapirone metabolism into 1-(2-pyrimidinyl)-piperazine (1-PP, an ?2-adrenoceptor antagonist) on the effect of ipsapirone on TSH release, and (2) the interaction between the corticosterone-releasing effect of ipsapirone and its inhibitory influence on TSH release.

Pierre Broqua; Dominique Laude; Marie-Thérèse Bluet-Pajot; Bernard Schmidt; Véronique Baudrie; Francis Chaouloff

1993-01-01

324

The Selective 5HT6 Receptor Antagonist Ro4368554 Restores Memory Performance in Cholinergic and Serotonergic Models of Memory Deficiency in the Rat  

Microsoft Academic Search

Antagonists at serotonin type 6 (5-HT6) receptors show activity in models of learning and memory. Although the underlying mechanism(s) are not well understood, these effects may involve an increase in acetylcholine (ACh) levels. The present study sought to characterize the cognitive-enhancing effects of the 5-HT6 antagonist Ro4368554 (3-benzenesulfonyl-7-(4-methyl-piperazin-1-yl)1H-indole) in a rat object recognition task employing a cholinergic (scopolamine pretreatment) and

Cindy K J Lieben; Arjan Blokland; Ayhan ??k; Eric Sung; Petra van Nieuwenhuizen; Rudy Schreiber; CKJ Lieben

2005-01-01

325

Synthesis and Characterization of a Polymeric Fluorocarbon-Diamine Reversed Phase Weak Anion Exchange Silica HPLC Column Packing  

Microsoft Academic Search

Polymeric fluorocarbon-diamine silica column packings were synthesized by first reacting a copolymer of chlorotrifluoroethylene and vinylidene fluoride (Kel-F 800) with piperazine and then reacting this product with aminopropyl silica. This mixed mode reversed phase-weak anion exchange HPLC column and a hydrocarbon (C-8) weak anion exchange silica HPLC column were compared for the separation of aromatic organic acids. Although the fluorocarbon

N. D. Danielson; J. Wangsa; S. A. Shamsi

1995-01-01

326

Estimation of ranolazine and eleven Phase I metabolites in human plasma by liquid chromatography-atmospheric pressure chemical ionisation mass spectrometry with selected-ion monitoring  

Microsoft Academic Search

The estimation of ranolazine, a novel piperazine derivative, and eleven of its Phase I metabolites has been undertaken by liquid chromatography-atmospheric pressure chemical ionisation mass spectrometry (LC-APCI-MS). Plasma samples, taken on day 5 of a multiple-dose study, were extracted by solid-phase extraction (SPE) and analysed, using a gradient HPLC system coupled to the APCI source of a Finnigan MAT TSQ

W. J. Herron; J. Eadie; A. D. Penman

1995-01-01

327

[ 18F] p-MPPF: A Radiolabeled Antagonist for the Study of 5HT 1A Receptors with PET  

Microsoft Academic Search

This paper summarizes the present status of the researches conducted with [18F]4-(2?-methoxyphenyl)-1-[2?-[N-(2??-pyridinyl)-p-fluorobenzamido]ethyl]-piperazine known as [18F]p-MPPF, a new 5-HT1A antagonist for the study of the serotonergic neurotransmission with positron emission tomography (PET). This includes chemistry, radiochemistry, animal data (rats, cats, and monkeys) with autoradiography and PET, human data with PET, toxicity, and metabolism.

A Plenevaux; C Lemaire; J Aerts; G Lacan; D Rubins; W. P Melega; C Brihaye; C Degueldre; S Fuchs; E Salmon; P Maquet; S Laureys; P Damhaut; D Weissmann; D Le Bars; J.-F Pujol; A Luxen

2000-01-01

328

Ejaculatory response induced by a 5HT 2 receptor agonist mCPP in rats: Differential roles of 5HT 2 receptor subtypes  

Microsoft Academic Search

It has been reported that systemic administration of m-CPP (1-[3-chlorophenyl] piperazine hydrochloride), a 5-HT2 receptor agonist, produces a 5-HT2C receptor-mediated penile erections and self-grooming in rats. In the present study, we examined the ability of m-CPP to induce ejaculation in rats and determined which 5-HT2 receptor subtypes may be involved in the m-CPP-induced ejaculation. The ejaculatory response was assessed by

Akihiko Yonezawa; Masaru Yoshizumi; Manabu Ebiko; Shin-nosuke Ise; Chizuko Watanabe; Hirokazu Mizoguchi; Yukio Kimura; Shinobu Sakurada

2008-01-01

329

Activation of ? 1 receptor subtype leads to neuroprotection in the rat primary neuronal cultures  

Microsoft Academic Search

The mechanisms of sigma (?) recoptor ligands-induced neuroprotective effects are controversial because both ? receptors and phencyclidine (PCP) binding sites of the N-methyl-d-aspartate (NMDA) receptor channel complex have been reported to contribute to these neuroprotective effects. Thus, to clarify the role of ? receptor in the neuroprotective effects, we examined the effects of 1-(3,4-dimethoxyphenethyl)-4-(3-phenylpropyl)piperazine dihydrochloride (SA4503), a novel ?1 receptor

Minako Nakazawa; Kiyoshi Matsuno; Shiro Mita

1998-01-01

330

Ion-channels on parasite muscle: pharmacology and physiology  

Microsoft Academic Search

Ion-channels are essential components of excitable cells. This fact has been exploited in the development of anthelmintic\\u000a agents; the majority of which act on nematode ion channels. The purpose of this review is to describe the site of action of\\u000a some frequently used anthelmintic compounds: nAChRs and levamisole\\/pyrantel; Glu-Cls and avermectins\\/mylbemycins; GABA receptors\\u000a and piperazine. Also described is some of

Alan P. Robertson; Richard J. Martin

2007-01-01

331

Hydrothermal synthesis and structural characterization of a new layered vanadium selenite: (C 4N 2H 12) 0.5[(VO) 2(H 2O) 2(SeO 3) 2(HSeO 3)  

Microsoft Academic Search

A layered vanadium selenite, (C4N2H12)0.5[(VO)2(H2O)2(SeO3)2(HSeO3)], has been hydrothermally synthesized and structurally characterized. Its structure is layered and can be described as vanadium selenite oxide layers with diprotonated piperazine occupying the interlayer space. The result of magnetic measurement for the title compound shows a typical antiferromagnetic interaction at low temperature.

Zhimin Dai; Guanghua Li; Zhan Shi; Xiaomin Liu; Shouhua Feng

2005-01-01

332

Pharmacological profile of MS377, a novel antipsychotic agent with selective affinity for ? receptors  

Microsoft Academic Search

Rationale: MS-377 ((R)-(+)-1-(4-chlorophenyl)-3-[4-(2-methoxyethyl)piperazin-1-yl]methyl-2-pyrrolidinone l-tartrate) was discovered as a new chemical entity with affinity for ? receptors and without affinities for dopamine receptors. Objective: In the present study, we examined the antipsychotic profile of MS-377 in several in vitro and in vivo experiments. Methods: As in vitro assays, radioligand binding assays for ?1, ?2, D2 and 5-HT2 receptors were performed. As

S. Takahashi; K. Sonehara; K. Takagi; T. Miwa; K. Horikomi; N. Mita; H. Nagase; K. Iizuka; K. Sakai

1999-01-01

333

Infarct size in rabbits: a modified method illustrated by the effects of propranolol and trimetazidine  

Microsoft Academic Search

Following a 45-min period of coronary occlusion the myocardial infarct that developed after 24 h of blood reperfusion in the rabbit heart was studied in three groups of animals: controls (n=7), and those pretreated with 3 mg·kg-1 of the piperazine derivative, trimetazidine (n=7) or propranolol at 0.3 mg·kg-1 (n=6). Twenty-four hours after coronary artery ligation for 45 min infarct size

A. J. Drake-Holland; P. R. Belcher; J. Hynd; M. I. M. Noble

1993-01-01

334

Effects of trimetazidine on in vivo coronary arterial platelet thrombosis  

Microsoft Academic Search

We used Folts' model of critical coronary artery stenosis with endothelial damage, which measures platelet-rich thrombus accumulation from cyclic flow reductions (CFRs). This paper reports results applied to trimetazidine, a member of the piperazine group. Trimetazidine at a dose of 1 mg\\/kg completely abolished CFRs caused by accumulating thrombus in the circumflex coronary artery in 4 of 8 open-chest anesthetized

Philip R. Belcher; Angela J. Drake-Holland; John W. Hynd; Mark I. M. Noble

1993-01-01

335

The influence of the nematode Syphacia oblevata on adjuvant arthritis in the rat.  

PubMed Central

The effect of infestation with the nematode Syphacia oblevata on adjuvant arthritis was studied in the rat. Animals with an established infestation with Syphacia were found to have a reduced incidence of arthritis after injection of Freund's complete adjuvant. Infested animals developing adjuvant arthritis were found to suffer from a less severe form of the disease than animals in which infestation had been eliminated with piperazine before immunization.

Pearson, D J; Taylor, G

1975-01-01

336

3,22-Dioxa-11,14-di-aza-penta-cyclo-[12.8.0.02,11.05,10.015,20]docosa-5(10),6,8,15(20),16,18-hexa-ene-4,21-dione  

PubMed Central

In the title compound, C18H14N2O4, the piperazine ring adopts a chair conformation and the dihedral angle between the aromatic rings is 13.09?(9)°. In the crystal, mol­ecules are linked along the c axis by C—H?? and N?? [H(N)–centroid distances = 2.8030?(2) and 3.376?(2)?Å] inter­actions between neighbouring mol­ecules.

Ren, Xiaolin; Feng, Jiao; Wang, Jinglin; Liu, Bin; Yang, Binsheng

2013-01-01

337

Adverse drug reactions: implications for the development of fluoroquinolones  

Microsoft Academic Search

Quinolone antibacterials, originally derived from anti-malarial compounds, have been developed through side-chain and nuclear manipulation, notably by piperazine and other mono- or bi-cyclic substitutions at the 7 position (giving anti-pseudomonal activity and greater anti- Gram-negative activity) and fluorination at various sites (giving increased anti-Gram-positive activity). The class has now been in clinical use for 40 years. Increased activity has not

Peter Ball

338

Calcium Absorption in Postmenopausal Osteoporosis: Benefit of HRT Plus Calcitriol, but not HRT Alone, in both Malabsorbers and Normal Absorbers  

Microsoft Academic Search

:   In a randomized trial involving 71 postmenopausal osteoporotic women with vertebral compression fractures, radiocalcium absorption\\u000a studies using the 45Ca single isotope method (?) were performed at baseline and after 8 months of treatment with either continuous combined hormone\\u000a replacement therapy (HRT, as piperazine estrone sulfate 0.625–0.937mg daily ± medroxyprogesterone acetate 2.5 mg daily depending\\u000a on uterine status) or HRT

M. L. Holzherr; R. W. Retallack; D. H. Gutteridge; R. I. Price; D. L. Faulkner; S. G. Wilson; R. K. Will; G. O. Stewart; B. G. A. Stuckey; R. L. Prince; R. A. Criddle; G. N. Kent; C. I. Bhagat; S. S. Dhaliwal; K. Jamrozik

2000-01-01

339

Relationship between anorexia and loss of serotonin uptake sites in brain of mice and rats receiving d-norfenfluramine or d-fenfluramine  

Microsoft Academic Search

Previously, we have shown that repeated administration of d-fenfluramine (D-F) to rats is associated with development of tolerance to the initial anorexia, but that in mice no such tolerance seems to occur. In the first study, we show that chronic administration of neither d-norfenfluramine (D-NF; the principal metabolite of D-F) nor the serotonin (5-HT) 2C receptor agonist m-chlorophenyl-piperazine (mCPP) is

Neil E. Rowland; Sana Rokadia; D. Joy Green; Kimberly Robertson

2004-01-01

340

Effect of HEPES buffer systems upon the pH, growth and survival of Mycoplasma mycoides subsp. mycoides small colony (MmmSC) vaccine cultures  

Microsoft Academic Search

The use of a buffer system based on N-[2-hydroxyethyl]piperazine-N?-[2-ethanesulfonic acid] (HEPES), in conjunction with standard Gourlay’s culture medium was investigated for the growth and maintenance of Mycoplasma mycoides subsp. mycoides SC vaccine strain T144. When the initial pH of the culture medium was adjusted to 8.0, 0.075 M HEPES–NaOH was found to be sufficient to prevent the pH falling below

Emma R Waite; John B March

2001-01-01

341

SA4503, a novel cognitive enhancer with ? 1 receptor agonist properties, facilitates NMDA receptor-dependent learning in mice  

Microsoft Academic Search

The selective ?1 receptor agonist 1-(3,4-dimethoxyphenethyl)-4-(3-phenyl propyl)piperazine dihydrochloride (SA4503) was reported to reverse the amnesia induced by the muscarinic receptor antagonist scopolamine at sub-mg\\/kg doses. We examined its effect on the learning impairment induced in mice by the non-competitive NMDA receptor antagonist dizocilpine. Learning capacities were evaluated using spontaneous alternation in the Y-maze for spatial working memory, and step-down type

Tangui Maurice; Alain Privat

1997-01-01

342

Ameliorative Effect of SA4503, a Novel Cognitive Enhancer, on the Basal Forebrain Lesion-Induced Impairment of the Spatial Learning Performance in Rats  

Microsoft Academic Search

We investigated the effect of successive administrations of SA4503 (1-(3,4-dimethoxyphenethyl)-4-(3-phenylpropyl)piperazine dihydrochloride), a novel cognitive enhancer with high affinity and selectivity for the ?1 receptor subtype, on the cortical cholinergic dysfunction-induced impairment of the spatial learning performance in the Morris water maze (MWM) task in rats. The impairment of the spatial learning performance was produced by the ibotenic acid-induced lesion of

Toshihiko Senda; Kiyoshi Matsuno; Tetsuya Kobayashi; Minako Nakazawa; Katsuhiko Nakata; Shiro Mita

1998-01-01

343

SA4503, a novel cognitive enhancer, with ? 1 receptor agonistic properties  

Microsoft Academic Search

We found a potent and selective sigma1 (?1) receptor ligand, SA4503 (1-(3,4-dimethoxyphenethyl)-4-(3-phenylpropyl)piperazine dihydrochloride). This compound had a high affinity for ?1 receptor subtype (IC50=17±1.9 nM), but a low affinity for ?2 receptor subtype (IC50 = 1800 ± 310 nM). The present study examines the effect of this compound on the central cholinergic functions, since ? receptor has been reported to

Kiyoshi Matsuno; Toshihiko Senda; Tetsuya Kobayashi; Kazuyoshi Okamoto; Katsuhiko Nakata; Shiro Mita

1997-01-01

344

HPLC analysis of the antidepressant trazodone and its main metabolite mCPP in human plasma  

Microsoft Academic Search

The present paper deals with the development of a rapid and feasible high-performance liquid chromatographic method for the determination of trazodone and its main active metabolite 3-(1-clorophenyl)piperazine (m-CPP) in human plasma. Trazodone is a second-generation antidepressant with serotonin antagonist activity. The metabolite seems to be involved in the onset of some side effects of trazodone therapy, thus its determination is

Laura Mercolini; Carolina Colliva; Mario Amore; Salvatore Fanali; Maria Augusta Raggi

2008-01-01

345

Singular value decomposition analysis of the torsional angles of dopamine reuptake inhibitor GBR 12909 analogs: effect of force field and charges  

Microsoft Academic Search

Three-dimensional quantitative structure-activity relationship (3D-QSAR) analysis of large, flexible molecules, such as the\\u000a dopamine reuptake inhibitor GBR 12909 (1), is complicated by the fact that they can take on a wide range of closely-related conformations. The first step in the analysis\\u000a is to classify the conformers into groups. Over 600 conformers each of a piperazine (2) and piperidine (3) analog

Deepangi Pandit; Anna Fiorentino; Supreet Bindra; Carol A. Venanzi

2011-01-01

346

Discriminative stimulus effects of m-chlorophenylpiperazine as a model of the role of serotonin receptors in anxiety  

Microsoft Academic Search

Serotonin is known to play a role in anxiety. The roles of serotonin reuptake and 5-HT1A receptors have been well characterized, but the contribution of other serotonin receptor subtypes is not as clear. 1-(3-Chlorophenyl)-piperazine (mCPP), which binds non-selectively to a wide range of serotonin receptors, has often been used to produce anxiety in humans and in animal models. Because functional

Michael B. Gatch

2003-01-01

347

Evaluation of the sensitising potential of 4 polyamines present in technical triethylenetetramine using 2 animal species.  

PubMed

Contact sensitivity to 4 polyamines present in technical grade triethylenetetramine was investigated using the 'VAA mouse' assay and the guinea pig maximization test (GPMT). The criteria used to assess sensitivity in the GPMT classed all substances as having the same degree of sensitising potential. The mouse assay ranked N-(2-piperazin-1-ylethyl)ethylenediamine as having a significantly greater sensitising potential than the other compounds. PMID:2966710

Maisey, J; Purchase, R; Robbins, M C; Miller, K

1988-03-01

348

A new intumescent flame retardant containing phosphorus and nitrogen: Preparation, thermal properties and application to UV curable coating  

Microsoft Academic Search

A novel intumescent flame retardant piperazine-N,N?-bis(acryloxyethylaryl-phosphoramidate) (N-PBAAP) containing phosphorus and nitrogen used for UV curable coating was synthesized and characterized by Fourier transform infrared spectrometry (FTIR), 1H and 31P nuclear magnetic resonances (NMRs). The thermal degradation and volatilized products of the N-PBAAP cured film were monitored by real time Fourier transform infrared (RT-FTIR) and thermal gravimetric-Fourier transform infrared (TG-FTIR) technique,

Lijuan Chen; Lei Song; Pin Lv; Ganxin Jie; Qilong Tai; Weiyi Xing; Yuan Hu

349

Buffers in daphnid culture and bioassay  

Microsoft Academic Search

When an algal diet is employed, or precipitation of dissolved inorganics during autoclaving is likely, or test circumstances introduce pH changes, addition of a buffer to daphnid culture or bioassay media is appropriate. Glycylglycine, employed in this research for 20 years, is unsuitable for general use because it required microbe-free cultures. In contrast, n-hydroxyethyl piperazine-n-2-propane sulfonic acid (HEPPSO) and N-2-hydroxyethyl

Kathleen I. Keating; Paula B. Caffrey; Brenda C. Dagbusan

1996-01-01

350

Cyclooctadepsipeptides—an anthelmintically active class of compounds exhibiting a novel mode of action  

Microsoft Academic Search

There are three major classes of anthelmintics for veterinary use: the benzimidazoles\\/prebenzimidazoles, the tetrahydropyrimidines\\/imidazothiazoles, and the macrocyclic lactones. In nematodes, there are five targets for the existing anthelmintics: the nicotinergic acetylcholine receptor which is the target of tetrahydropyrimidines\\/imidazothiazoles and indirectly that of the acetylcholineesterase inhibitors; the GABA receptor which is the target of piperazine, the glutamate-gated chloride channel as the

Achim Harder; Hans-Peter Schmitt-Wrede; Jürgen Krücken; Predrag Marinovski; Frank Wunderlich; James Willson; Kiran Amliwala; Lindy Holden-Dye; Robert Walker

2003-01-01

351

Novel 4-substituted-2(1H)-phthalazinone derivatives: synthesis, molecular modeling study and their effects on ?-receptors.  

PubMed

Novel 4-(4-bromophenyl)phthalazine derivatives connected via an alkyl spacer to amine or N-substituted piperazine were designed and synthesized as promising ?-adrenoceptor antagonists. The structures of the phthalazine derivatives were established using elemental and spectral analyses. Twelve of the tested compounds displayed significant ?-blocking activity. Molecular modeling studies were performed to rationalize the biological results. Among the tested compounds, 7j displayed the best-fitting score and the highest in vitro activity. PMID:23543653

Khalil, Nadia A; Ahmed, Eman M; Elshihawy, Hosam A; Zaitone, Sawsan A

2013-06-01

352

Low-energy process recovers CO/sub 2/  

SciTech Connect

This paper discusses processes for removal of acid gas constituents from natural gas, which include the alkanolamine processes such as monethanolamine (MEA) and DEA, but also physical solvent processes such as Selexol, Sepasolv MPE, Rectisol, and Purisol. It points out that a key advantage of physical solvent processes is that the solution can be regenerated by flashing rather than by the steam stripping used in the conventional alkanolamine processes. A single-stage and two-stage activated MDEA process developed in West Germany for treating high-pressure natural gas is described. The one or two-stage process is also applicable to high pressure natural gas streams containing both H/sub 2/S and CO/sub 2/.

Meissner, R.E. III; Wagner, U.

1983-02-07

353

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

354

New types of 3D organically templated Zn2+/Cd2+-Cu+ mixed metal sulfites.  

PubMed

Two types of new organically templated mixed-metal sulfites, namely, [H(2)pip][NaZn(2)Cu(SO(3))(4)] (1) and [H(2)pip][CdCu(4)(SO(3))(4)] (2) (pip = piperazine), have been synthesized under hydrothermal conditions and structurally characterized. Both compounds exhibit a novel 3D mixed-metal inorganic framework with organic template molecules occupying the tunnels of the inorganic skeleton. Compound 1 features a 2D Zn(2)Cu(SO(3))(4)(3-) layer parallel to the ac plane in which the 1D chains of Zn(SO(3))(2)(2-) anions along the c axis are interconnected with the Cu(+) ions via Cu-S bonds. Neighboring Zn(2)Cu(SO(3))(4)(3-) layers are further interconnected by bridging Na(+) ions via Na-O-S bonds into a 3D network, forming 1D tunnels along the a axis which are occupied by the doubly protonated piperazine cations. Compounds 2 features a novel 3D inorganic framework of CdCu(4)(SO(3))(4)(2-) with 2D layers based on Cu(4)(SO(3))(4)(4-) cubanelike clusters. The cluster layers are further interconnected by Cd(II) ions, forming 1D tunnels of eight-membered rings along the c axis in which the piperazine template cations are located. Luminescent property measurements as well as band structure calculations based on density functional theory methods were also made. PMID:19456144

Li, Pei-Xin; Hu, Chun-Li; Lin, Qi-Pu; Zhao, Na; Mao, Jiang-Gao

2009-06-15

355

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.

Wang, Pei; Xi, Lijun; Liu, Peipei; Wang, Yi; Wang, Wei; Huang, Ying; Zhu, Weiming

2013-01-01

356

Targeting tumor hypoxia with 2-nitroimidazole-indocyanine green dye conjugates  

NASA Astrophysics Data System (ADS)

Tumor hypoxia is a major indicator of treatment resistance to chemotherapeutic drugs, and fluorescence optical tomography has tremendous potential to provide clinically useful, functional information by identifying tumor hypoxia. The synthesis of a 2-nitroimidazole-indocyanine green conjugate using a piperazine linker (piperazine-2-nitroimidazole-ICG) capable of robust fluorescent imaging of tumor hypoxia is described. In vivo mouse tumor imaging studies were completed and demonstrate an improved imaging capability of the new dye relative to an earlier version of the dye that was synthesized with an ethanolamine linker (ethanolamine-2-nitroimidazole-ICG). Mouse tumors located at imaging depths of 1.5 and 2.0 cm in a turbid medium were imaged at various time points after intravenous injection of the dyes. On average, the reconstructed maximum fluorescence concentration of the tumors injected with piperazine-2-nitroimidazole-ICG was twofold higher than that injected with ethanolamine-2-nitroimidazole-ICG within 3 h postinjection period and 1.6 to 1.7 times higher beyond 3 h postinjection. The untargeted bis-carboxylic acid ICG completely washed out after 3 h postinjection. Thus, the optimal window to assess tumor hypoxia is beyond 3 h postinjection. These findings were supported with fluorescence images of histological sections of tumor samples and an immunohistochemistry technique for identifying tumor hypoxia.

Xu, Yan; Zanganeh, Saeid; Mohammad, Innus; Aguirre, Andres; Wang, Tianheng; Yang, Yi; Kuhn, Liisa; Smith, Michael B.; Zhu, Quing

2013-06-01

357

Simultaneous determination of psychotropic phenylalkylamine derivatives in human hair by gas chromatography/mass spectrometry.  

PubMed

A gas chromatography/mass spectrometric (GC/MS) method was developed and validated for the determination of thirteen psychotropic phenylalkylamine derivatives (amphetamine; AP, phentermine; PT, methamphamine; MA, cathinone; Khat, methcathinone; MCAT, fenfluramine; FFA, desmethylselegiline; DSEL, 3,4-methylenedioxyamphetamine; MDA, 3,4-methylenedioxymethamphetamine; MDMA, 3,4-methylenedioxyethylamphetamine; MDEA, norketamine; NKT, mescaline; MES, 4-bromo-2,5-dimethoxyphenethylamine; 2CB) in human hair. Hair samples (20 mg) were washed with distilled water and acetone, cut into small fragments (<1 mm), and incubated in 0.25 M methanolic HCl under ultrasonication at 50 degrees C for 1 h. The resulting solutions were evaporated to dryness, derivatized using trifluoroacetic anhydride (TFAA) at 70 degrees C for 30 min, and analyzed by GC/MS. The linear ranges were 0.02-25.0 ng/mg for AP, PT, Khat, FFA, DSEL, MDMA, and 2CB; 0.05-25.0 ng/mg for MA, MCAT, and MES; 0.05-12.5 ng/mg for MDA; and 0.1-25.0 ng/mg for MDEA and NKT, with good correlation coefficients (r(2) > 0.9985). The intra-day, inter-day, and inter-person precisions were within 12.7%, 14.8%, and 16.8%, respectively. The intra-day, inter-day, and inter-person accuracies were between -10.7 and 13.4%, -12.7 and 11.6%, and -15.3 and 11.9%, respectively. The limits of quantifications (LOQs) for each compound were lower than 0.08 ng/mg. The recoveries were in the range of 76.7-95.6%. The method proved to be suitable for the simultaneous qualification and quantification of phenylalkylamine derivatives in hair specimens. PMID:17474080

Kim, Jin Young; Jung, Kyu Sung; Kim, Min Kyoung; Lee, Jae Il; In, Moon Kyo

2007-01-01

358

Homoleptic gallium(III) and indium(III) aminoalkoxides as precursors for sol-gel routes to metal oxide nanomaterials.  

PubMed

New homoleptic aminoalkoxides of gallium(III) and indium(III) of the types M4{(OC2H4)2NMe}6 [M = Ga (1), In (2)] and [Ga{(OC2H4)3N}]n (3), as well as a previously described Ga2(OC2H4NMe2)6 (A) have been prepared by isopropoxo(chloro)-aminoalkoxo exchange reactions and characterised by elemental analyses, FT-IR and 1H NMR spectroscopy. Formation of a star-shaped Ga[Ga{mu-eta3:eta1-(OC2H4)2NMe}2]3 (1.4CHCl3) and a zigzag linear In4{mu-eta3:eta1-(OC2H4)2NMe}6 (2.6CHCl3), as revealed by X-ray single crystal structures, reflects the structural diversity among N-methyldiethanolaminate derivatives. Their hydrolyses in boiling water, either in presence or absence of tetraalkylamonium bromide, have been studied and, for gallium derivatives, compared with similar hydrolytic reactions of Ga(OiPr)3. The hydrolysed products were studied by FT-IR, TG-DTA and XRD techniques. For gallium derivatives, transition from orthorhombic Ga(O)OH phase of as-prepared powder to phase pure rhombohedral- and monoclinic-Ga2O3 occurred at about 500 degrees C and 700 degrees C, respectively, whereas cubic In(OH)3 phase of as-prepared powder of 2 was converted to cubic In2O3 at 250 degrees C. Partial hydrolyses were also performed and evolution of the particle size in solution was recorded by light scattering measurements. Various sol-gel processing parameters such as concentration and hydrolysis ratio (h) were studied in order to stabilise nano-sized colloidal suspensions for access to thin films by spin coating. The N-methyldiethanolamine derivatives 1 and 2 were found to be the most suitable candidates for sol-gel processing. The transparent Ga2O3 and In2O3 films obtained on glass or Si wafers from spin-coating of 1 and 2, respectively, were characterised by SEM, EDX and XRD. PMID:19319402

Mishra, Shashank; Daniele, Stéphane; Petit, Sarah; Jeanneau, Erwann; Rolland, Marc

2009-02-13

359

Heterometallic Cu/Co and Cu/Co/Zn complexes bearing rare asymmetric tetranuclear cores: synthesis, structures, and magnetic and catalytic properties toward the peroxidative oxidation of cycloalkanes.  

PubMed

The three novel heterometallic complexes [CuCo(III)Co(II)(2)(MeDea)(3)Cl(3)(CH(3)OH)(0.55)(H(2)O)(0.45)](H(2)O)(0.45) (1), [CuCo(III)Zn(2)(MeDea)(3)Cl(3)(CH(3)OH)(0.74)(H(2)O)(0.26)](H(2)O)(0.26) (2), and [CuCo(III)Zn(2)(MeDea)(3)Cl(3)(DMF)] (3) have been prepared using a one-pot reaction of copper powder with cobalt chloride (1) and zinc nitrate (2, 3) in a methanol (1, 2) or dimethylformamide (3) solution of N-methyldiethanolamine. A search of the Cambridge Structural Database shows that the tetranuclear asymmetric cores M(4)(?(3)-X)(?-X)(5) of 1-3 represent an extremely rare case of M(4)X(6) arrays. The magnetic investigations of 1 disclose antiferromagnetic coupling in a Co(II)-Cu(II)-Co(II) exchange fragment with J(Co-Cu)/hc = -4.76 cm(-1), J(Co-Co)/hc = -2.76 cm(-1), and D(Co)/hc = +34.3 cm(-1). Compounds 1-3 act as precursors for the mild peroxidative oxidation of cyclohexane to cyclohexanol and cyclohexanone with overall yields up to 23%. The synthetic and structural features as well as the thermogravimetric behavior and electrospray ionization mass spectrometry data are discussed. PMID:21506552

Nesterov, Dmytro S; Kokozay, Volodymyr N; Jezierska, Julia; Pavlyuk, Oleksiy V; Bo?a, Roman; Pombeiro, Armando J L

2011-04-20

360

Gas separation using ion exchange membranes for producing hydrogen from synthesis gas  

SciTech Connect

The main goal of this project is to demonstrate the use of facilitated transport membranes to separate gases resulting from the formation of H{sub 2}, specifically C0{sub 2} and H{sub 2}S from CO and H{sub 2}. As part of this goal a field test is performed at a producing natural gas plant (Carter Creek Chevron Natural Gas Plant, Evanston, WY) to evaluate the performance and long term stability of candidate membranes. Laboratory work at the National Institute of Standard and Technology (NIST) leads and parallels the field tests. Through a series of tests in the WIST laboratory and at the Chevron/Carter Creek test rig, the investigators are establishing the apparent separation and productivity capabilities of polymer membranes imbibed with various solvents and chemical carriers. In some samples the membranes are also subjected to solvent-swelling heat treatment (gel-treatment). The polymer material is polyperfluorosufonic acid (PFSA-Nafion). The chemical carriers, e.g. methyldiethanolamine (EDA) and ethylenediamine (EDA) enhance the transport and selectivity of the membrane. They may be in solution with H{sub 2}0, glycerol, ethylene glycol, and n-methylpyrrolidone (NMP). Nafion 117 (NE117) is a commercial film, 200 microns thick, which is available from DuPont Co. A developmental polymer film, Nafion 111 (NE111) 30--40 microns thick was made available by the DuPont Co.

Pellegrino, J.J.; Giarratano, P.J.

1992-01-01

361

Gas separation using ion exchange membranes for producing hydrogen from synthesis gas. Quarterly report 22 covering the period October 1, 1991--December 31, 1991  

SciTech Connect

The main goal of this project is to demonstrate the use of facilitated transport membranes to separate gases resulting from the formation of H{sub 2}, specifically C0{sub 2} and H{sub 2}S from CO and H{sub 2}. As part of this goal a field test is performed at a producing natural gas plant (Carter Creek Chevron Natural Gas Plant, Evanston, WY) to evaluate the performance and long term stability of candidate membranes. Laboratory work at the National Institute of Standard and Technology (NIST) leads and parallels the field tests. Through a series of tests in the WIST laboratory and at the Chevron/Carter Creek test rig, the investigators are establishing the apparent separation and productivity capabilities of polymer membranes imbibed with various solvents and chemical carriers. In some samples the membranes are also subjected to solvent-swelling heat treatment (gel-treatment). The polymer material is polyperfluorosufonic acid (PFSA-Nafion). The chemical carriers, e.g. methyldiethanolamine (EDA) and ethylenediamine (EDA) enhance the transport and selectivity of the membrane. They may be in solution with H{sub 2}0, glycerol, ethylene glycol, and n-methylpyrrolidone (NMP). Nafion 117 (NE117) is a commercial film, 200 microns thick, which is available from DuPont Co. A developmental polymer film, Nafion 111 (NE111) 30--40 microns thick was made available by the DuPont Co.

Pellegrino, J.J.; Giarratano, P.J.

1992-01-01

362

Photocatalytic dechlorination of PCB 138 using leuco-methylene blue and visible light; reaction conditions and mechanisms.  

PubMed

A study of dechlorination of PCB 138, under visible light employing methylene blue (MB) and triethylamine (TEA) in acetonitrile/water has been conducted to investigate the details of the mechanism of dechlorination and to determine the efficiency of the process for this representative congener. Two other amines, N-methyldiethanolamine (MEDA) and (triethanolamine) TEOA also replaced TEA and two other solvents, methanol and ethanol replacing acetonitrile were examined for effects on reaction rates. The results show that PCB 138 can be dechlorinated efficiently in this photocatalytic reaction. Clarifying ambiguities in several previous reports, the reduced form of MB, leuco-methylene blue (LMB) was identified as responsible for the photoreaction with its excited state transferring an electron to PCBs; oxidized LMB (i.e. MB) is reduced back to LMB by the excess amine present. The reaction depends on a cycle driven by the amine as a sacrificial electron donor. MEDA proved to be the most efficient electron donor; apparently in consequence of the most favourable steady state concentration of LMB. Methanol and ethanol may be used to replace acetonitrile with little change in the efficiency of the reaction. PMID:20542375

Izadifard, Maryam; Langford, Cooper H; Achari, Gopal

2010-05-12

363

Analysis of Ethanolamines: Validation of Semi-Volatile Analysis by HPLC-MS/MS by EPA Method MS888  

SciTech Connect

The Environmental Protection Agency's (EPA) Region 5 Chicago Regional Laboratory (CRL) developed a method titled 'Analysis of Diethanolamine, Triethanolamine, n-Methyldiethanolamine, and n-Ethyldiethanolamine in Water by Single Reaction Monitoring Liquid Chromatography/Tandem Mass Spectrometry (LC/MS/MS): EPA Method MS888'. This draft standard operating procedure (SOP) was distributed to multiple EPA laboratories and to Lawrence Livermore National Laboratory, which was tasked to serve as a reference laboratory for EPA's Environmental Reference Laboratory Network (ERLN) and to develop and validate analytical procedures. The primary objective of this study was to validate and verify the analytical procedures described in 'EPA Method MS888' for analysis of the listed ethanolamines in aqueous samples. The gathered data from this validation study will be used to: (1) demonstrate analytical method performance; (2) generate quality control acceptance criteria; and (3) revise the SOP to provide a validated method that would be available for use during a homeland security event. The data contained in this report will be compiled, by EPA CRL, with data generated by other EPA Regional laboratories so that performance metrics of 'EPA Method MS888' can be determined.

Owens, J; Vu, A; Koester, C

2008-10-08

364

Prevalence and co-existence of active components of 'legal highs'.  

PubMed

The results of a study performed on samples of 'legal highs' seized in head shops by law enforcement and health services in Poland between mid-2008 and mid-2011 are presented. In total, 449 preparations which differed in labelling, net masses, forms of distribution, etc., were analyzed. A variety of sophisticated analytical methods, including gas chromatography-mass spectrometry (GC-MS), liquid chromatography-quadropole time-of-flight mass spectrometry (LC-QTOF-MS), high performance liquid chromatography (HPLC), and nuclear magnetic resonance (NMR) were applied for component identification and quantification. The most common ingredients of legal highs were (in descending order): MPDV, caffeine, butylone, TFMPP, lidocaine, 4-MEC, mephedrone, pFPP, BZP, and MDPBP. The scatter of substances changed over time, and piperazines were often ousted by cathinones. Most of the preparations were composed of two or more ingredients. Cathinones and piperazines were mixed mainly within the chemical classes (77.6% and 56.1% of dual links, respectively), caffeine was mixed both with piperazines (24 products) and cathinones (22 products), whereas lidocaine only with the latter class (47 products). A great inconsistency in the qualitative and quantitative composition of products with identical labelling was shown in an example of Coco products seized after August 2010; we found 10 different single component or mixture preparations, and the content of individual ingredients varied from several to hundreds of mgs. This paper summarizes potential dangers connected with the uncontrolled sale of psychoactive substances, and indicates important issues concerning the analysis of legal highs. PMID:22549997

Zuba, Dariusz; Byrska, Bogumi?a

2012-05-01

365

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

2013-05-24

366

Oxidation of fluoroquinolone antibiotics and structurally related amines by chlorine dioxide: Reaction kinetics, product and pathway evaluation.  

PubMed

Fluoroquinolones (FQs) are a group of widely prescribed antibiotics and have been frequently detected in the aquatic environment. The reaction kinetics and transformation of seven FQs (ciprofloxacin (CIP), enrofloxacin (ENR), norfloxacin (NOR), ofloxacin (OFL), lomefloxacin (LOM), pipemidic acid (PIP) and flumequine (FLU)) and three structurally related amines (1-phenylpiperazine (PP), N-phenylmorpholine (PM) and 4-phenylpiperidine (PD)) toward chlorine dioxide (ClO(2)) were investigated to elucidate the behavior of FQs during ClO(2) disinfection processes. The reaction kinetics are highly pH-dependent, can be well described by a second-order kinetic model incorporating speciation of FQs, and follow the trend of OFL > ENR > CIP ? NOR ? LOM > > PIP in reactivity. Comparison among FQs and related amines and product characterization indicate that FQs' piperazine ring is the primary reactive center toward ClO(2). ClO(2) likely attacks FQ's piperazinyl N4 atom followed by concerted fragmentation involving piperazinyl N1 atom, leading to dealkylation, hydroxylation and intramolecular ring closure at the piperazine moiety. While FQs with tertiary N4 react faster with ClO(2) than FQs with secondary N4, the overall reactivity of the piperazine moiety also depends strongly on the quinolone ring through electronic effects. The reaction rate constants obtained in clean water matrix can be used to model the decay of CIP by ClO(2) in surface water samples, but overestimate the decay in wastewater samples. Overall, transformation of FQs, particularly for those with tertiary N4 amines, could be expected under typical ClO(2) disinfection conditions. However, the transformation may not eliminate antibacterial activity because of little destruction at the quinolone ring. PMID:20708211

Wang, Pei; He, Yi-Liang; Huang, Ching-Hua

2010-07-27

367

A fluorine 1,2-migration via aryl cation/radical/radical anion/radical sequence.  

PubMed

Irradiation of a 7-piperazino-8-fluoroquinolone causes formal 1,2-fluorine migration, piperazine loss and reduction, or nucleophile addition in 8. Product study, laser flash photolysis, and computational modeling support F(-) detachment to yield a triplet 8-quinolyl cation that either inserts intramolecularly or is trapped by Cl(-), Br(-). However, iodide and pyrrole reduce it to the radical that continues the 'redox tour' (aryl cation? radical? radical anion? radical and then again radical or radical anion) leading to the rearranged products. PMID:23869692

Pretali, Luca; Dondi, Daniele; D'Angelantonio, Mila; Manet, Ilse; Fasani, Elisa; Monti, Sandra; Bovio, Bruna; Albini, Angelo

2013-07-19

368

Triamino derivatives of triazolotriazine and triazolopyrimidine as adenosine A2a receptor antagonists.  

PubMed

Piperazine derivatives of 2-furanyl[1,2,4]triazolo[1,5-a][1,3,5]triazine have recently been shown to be potent and selective adenosine A(2a) receptor antagonists. We now demonstrate that potent and selective A(2a) receptor antagonists could still be obtained when the arylpiperazines are separated from the triazolotriazine core structure by an ethylenediamine spacer. Selected analogs bearing this triazolotriazine or the related triazolopyrimidine core structure have been found to be orally active in a mouse catalepsy model of Parkinson's disease. PMID:15341934

Vu, Chi B; Shields, Pamela; Peng, Bo; Kumaravel, Gnanasambandam; Jin, Xiaowei; Phadke, Deepali; Wang, Joy; Engber, Thomas; Ayyub, Eman; Petter, Russell C

2004-10-01

369

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

370

Human Immunodeficiency Virus 1 (HIV1)Specific Reverse Transcriptase (RT) Inhibitors may Suppress the Replication of Specific Drug-Resistant (E138K)RT HIV1 Mutants or Select for Highly Resistant (Y181C --> C181I)RT HIV1 Mutants  

Microsoft Academic Search

Mutant HIV-1 that expresses a Glu138--> Lys substitution in its RT [(E138K)RT] is resistant to the HIV-1-specific RT inhibitor 2',5'-bis-O-(tert-butyldimethylsilyl)-3'-spiro-5''-(4''-amino-1'',2''- oxathiole-2'',2''-dioxide)pyrimidine (TSAO). However, cell cultures infected with this mutant were completely protected against virus-mediated destruction by micromolar concentrations of the HIV-1-specific RT inhibitors tetrahydroimidazo[4,5,1-jk][1,4]benzodiazepin-2(1H)-one and -thione (TIBO), nevirapine, and bis(heteroaryl)piperazine (BHAP). In contrast, cells infected with a virus mutant that

Jan Balzarini; Anna Karlsson; Vinod V. Sardana; Emilio A. Emini; Maria-Jose Camarasa; Erik de Clercq

1994-01-01

371

BIMT 17, a 5HT 2A receptor antagonist and 5HT 1A receptor full agonist in rat cerebral cortex  

Microsoft Academic Search

In the search for antidepressant agents with a rapid onset of action, we have found that compound BIMT 17 (1-[2-[4-(3-trifluoromethylphenyl)piperazin1-yl]ethyl]benzimidazol-[1H]-2-one) shows a good affinity for cerebral cortical 5-HT1A (pKi = 7.72) and 5-HT2A (pKi = 6.90) receptors, with no appreciable affinity for the other 5-HT receptor subtypes, including 5-HT2C. BIMT 17 reduced forskolin-stimulated cAMP accumulation in the cerebral cortex (pEC50

F. Borsini; E. Giraldo; E. Monferini; G. Antonini; M. Parenti; G. Bietti; A. Donetti

1995-01-01

372

Inhibitory Effect of the New Orally Active CCR4 Antagonist K327 on CCR4+CD4+ T Cell Migration into the Lung of Mice with Ovalbumin-Induced Lung Allergic Inflammation  

Microsoft Academic Search

CC chemokine receptor 4 (CCR4) is expressed on Th2 cells, found in inflamed tissues of allergic diseases, and is therefore suspected to be involved in the pathogenesis of allergic diseases by controlling Th2 cell migration into inflamed tissues. The aim of the present study was to investigate the inhibitory effect of a selective CCR4 antagonist, K327 [6-cyclopropancarbonyl-4-(2,4-dichlorobenzylamino)-2-(4-[2-(piperidin-1-yl)ethyl] piperazin-1-yl)-7,8-dihydro-5H-pyrido (4,3-d)pyrimidine], on

Takashi Sato; Masato Komai; Miho Iwase; Katsuya Kobayashi; Harunobu Tahara; Etsuo Ohshima; Hitoshi Arai; Ichiro Miki

2009-01-01

373

3,8-Dimethyl-quinazoline-2,4(1H,3H)-dione  

PubMed Central

In the title compound, C10H10N2O2, all non-H atoms are approximately co-planar with an r.m.s. deviation of 0.016?Å. In the crystal, mol­ecules are linked into inversion dimers by pairs of N—H?O hydrogen bonds. Chains along [010] are buiilt up by ?–? inter­actions [centroid–centroid distance = 3.602?(1)?Å] between the benzene and piperazine rings of adjacent mol­ecules.

Qin, Wei-Yan; Liu, Bo; Duan, Cong-Wen; Yin, Qing-Xiu

2011-01-01

374

Synthesis and analgesic activity of some side-chain modified anpirtoline derivatives.  

PubMed

New derivatives of anpirtoline and deazaanpirtoline modified in the side chain have been synthesized. The series includes compounds 3 with side-chains containing piperidine or pyrrolidine rings, compounds 4 containing 8-azabicyclo[3.2.1]octane moiety, and compounds 5 having piperazine ring in their side-chains. Their receptor binding profiles (5-HT1A, 5-HT1B) and analgesic activity (hot plate, acetic acid induced writhing) have been studied. Optimized structures (PM3-MOPAC, Alchemy 2000, Tripos Inc.) of the synthesized compounds 3-5 were compared with that of anpirtoline. PMID:10863793

Rádl, S; Hezky, P; Proska, J; Hejnová, L; Krejcí, I

2000-05-01

375

Involvement of ?-opioid and ? receptors in short-term memory in mice  

Microsoft Academic Search

?-Opioid receptor agonists, trans-(±)-3,4-dichloro-N-methyl-N-(2-[1-pyrrolidinyl] cyclohexyl) benzeneacetamide methanesulfonate (U-50,488H) and dynorphin A-(1–13), improve impairments of learning and memory in mice and rats. ? Receptor agonists, (+)-N-allylnormetazocine ((+)-SKF10,047) and 1-(3,4-dimethoxyphenethyl)-4-(3-phenylpropyl) piperazine dihydrochloride (SA4503), also reverse learning and memory impairment in various animal models. However, the mechanisms underlying these effects are not well understood. In the present study, the effect of coadministration of

Masayuki Hiramatsu; Takashi Hoshino; Tsutomu Kameyama; Toshitaka Nabeshima

2002-01-01

376

The novel, selective, brain-penetrant neuropeptide Y Y2 receptor antagonist, JNJ-31020028, tested in animal models of alcohol consumption, relapse, and anxiety  

Microsoft Academic Search

Neuropeptide Y (NPY) signaling has been shown to modulate stress responses and to be involved in regulation of alcohol intake and dependence. The present study explores the possibility that blockade of NPY Y2 autoreceptors using a novel, blood–brain barrier penetrant NPY Y2 receptor antagonist, JNJ-31020028 (N-(4-{4-[2-(diethylamino)-2-oxo-1-phenylethyl]piperazin-1-yl}-3-fluorophenyl)-2-pyridin-3-ylbenzamide), may achieve a therapeutically useful activation of the NPY system in alcohol- and anxiety-related

Andrea Cippitelli; Amir H. Rezvani; J. Elliott Robinson; Lindsay Eisenberg; Edward D. Levin; Pascal Bonaventure; S. Timothy Motley; Timothy W. Lovenberg; Markus Heilig; Annika Thorsell

2011-01-01

377

Synthesis and structural characterization of a carboxylate bridged tetranuclear copper complex derived from reduced Schiff base asymmetric compartmental ligand containing an amino acid side arm  

Microsoft Academic Search

The dinucleating asymmetric reduced Schiff base compartmental ligand H2L {2-[5-bromo-2-hydroxy-3-(4-methyl-piperazin-1-ylmethyl)-benzylamino]-propionic acid} (see Scheme 1 for H2L) gives the tetracopper(II) complex [Cu4L2(CH3COO)4]·2CH3CN·2H2O (1) on reaction with (CH3COO)2Cu·H2O. The single crystal X-ray structure of 1 reveals that this complex is a carboxylate bridged dimer of dinuclear copper(II) subunits, in which the copper(II) centers adopt different geometries, resulting in a {Cu4} complex.

Chullikkattil P. Pradeep; Panthapally S. Zacharias; Samar K. Das

2006-01-01

378

Comparative Behavioral Pharmacology of Cocaine and the Selective Dopamine Uptake Inhibitor RTI-113 in the Squirrel Monkey1  

Microsoft Academic Search

The behavioral effects of 3b-(4-chlorophenyl)tropane-2b-car- boxylic acid phenyl ester hydrochloride (RTI-113; 0.03-1.0 mg\\/ kg), a selective dopamine uptake inhibitor, were compared with those of cocaine (0.03-3.0 mg\\/kg) and 1-{2-(bis(4-fluorophenyl- )methoxy)ethyl}-4-(3-phenylpropyl)piperazine dihydrochloride (GBR 12909; 0.03-3.0 mg\\/kg) in squirrel monkeys. Intermediate doses of each drug produced significant increases in response rate maintained by a fixed-interval (FI) 300-s schedule of stimulus termination, but

LEONARD L. HOWELL; PAUL W. CZOTY; MICHAEL J. KUHAR; F. IVY CARROL

379

bis (Xylenedithiocarboxylate)oxovanadium(IV) and Adducts with Organic Bases  

Microsoft Academic Search

We report the synthesis and study of bis(xylene-dithiocarboxylate)oxovanadiuum(IV) and its adducts with cyclohexylaraine, piperidine, morpholine, piperazine and pyrrolidine. The compounds have been characterized by analytical, magnetochemical, IR and visible-UV spectral methods and analytical data, and are assigned respectively to the formula VO(C8H9CS2)2 and VO(C8H9CS2)2 B. The effect of adduct formation on the ?v=o bond are discussed in terms of the

A. L. Doadrio Villarejo; C. V. Ragel; G. Pérez Cuevas

1992-01-01

380

Bis(toluene dithiocarboxylate)oxovanadium(IV) and its adducts with organic bases  

Microsoft Academic Search

Summary  We report the synthesis ofbis(toluene dithiocarboxylate)oxovanadium(IV) and its adducts with cyclohexylamine, piperidine, morpholine, piperazine and pyrrolidine\\u000a which have been characterized by physico-chemical and spectroscopic methods, and assigned the formulae [VO(C8H7CS2)2] and [VO(C8H7CS2)2·B](B=nitrogen base) and the coordination sphere [VOS4N]. The effects of adduct formation are discussed on the basis of the i.r. (V=O, V?S and V?N stretching frequencies) and electronic\\u000a spectra

Antonio L. Doadrio-Villarejo; Victoria C. Ragel; Gabriel Pérez-Cuevas

1992-01-01

381

Cariprazine (RGH-188), a potent D 3\\/D 2 dopamine receptor partial agonist, binds to dopamine D 3 receptors in vivo and shows antipsychotic-like and procognitive effects in rodents  

Microsoft Academic Search

We investigated the in vivo effects of orally administered cariprazine (RGH-188; trans-N-{4-[2-[4-(2,3-dichlorophenyl)-piperazin-1-yl]-ethyl]-cyclohexyl}-N?,N?-dimethyl-urea), a D3\\/D2 dopamine receptor partial agonist with ?10-fold preference for the D3 receptor. Oral bioavailability of cariprazine at a dose of 1mg\\/kg in rats was 52% with peak plasma concentrations of 91ng\\/mL. Cariprazine 10mg\\/kg had good blood–brain barrier penetration, with a brain\\/plasma AUC ratio of 7.6:1. In rats,

István Gyertyán; Béla Kiss; Katalin Sághy; Judit Laszy; Györgyi Szabó; Tamás Szabados; Larisza I. Gémesi; Gabriella Pásztor; Mária Zájer-Balázs; Margit Kapás; Éva Ágai Csongor; György Domány; Károly Tihanyi; Zsolt Szombathelyi

2011-01-01

382

Compounds derived from 2-(3-methylenedioxy)-benzoyl indol  

US Patent & Trademark Office Database

The present invention describes a series of derivatives of 2-(3-methylenedioxy)-benzoyl indol, their mixtures, their pharmaceutically acceptable salts, their enantiomers, pharmaceutical compositions comprising them, processes for preparing them, use in the prophylactic and/or curative treatment of sexual dysfunction. More specifically, the invention describes derivatives (R)-3-((2-(benzo[d][1,3]dioxol-5-carbonyl)-1H-indol-3-yl)methyl)-1-methyl- piperazine-2,5-dione, and S)-3-((2-(benzo[d][1,3]dioxol-5-carbonyl)-1H-indol-3-yl)methyl)-1-methylp- iperazine-2,5-dione.

Sacurai; Sergio Luiz (Sao Paulo, BR); Touzarim; Carlos Eduardo Da Costa (Sao Paulo, BR); Zaim; Marcio Henrique (Sao Paulo, BR)

2012-09-18

383

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

384

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

385

Rapid method for isolating targeted organic chemicals from biological matrices  

SciTech Connect

The initial development is reported for a novel countercurrent filtration/dialysis and solid phase extractant system for the rapid isolation of low molecular weight target compounds from biological media. Except for piperazine (a highly water-soluble drug), recoveries of 50 - 95% were achieved for chemical warfare agent simulants and anthelmintic drugs extracted from meat, grain, or milk. The results suggest the potential for broad applications to complex samples such as environmental media and physiological specimens which traditionally require extensive fractionation prior to analysis.

Caton, J.E.; Griest, W.H.; Watson, A.P.; Buchanan, M.V. (Oak Ridge National Lab., TN (United States)); Hazen, K.H. (Univ. of Iowa, Iowa City, IA (United States))

1994-01-01

386

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.

Mali, R. G.; Wadekar, R. R.

2008-01-01

387

Exogenous bridging and nonbridging in copper(II) complexes of a binculeating 2,6-bis((N-methylpiperazino)methyl)-4-chlorophenolate ligand. Crystal structures and magnetic properties of Bis(. mu. -acetato), dinitrito, and bis(azido) complexes. Possible relevance to the type 3 depleted laccase active site  

SciTech Connect

As part of a wide study of the structure/magnetism/redox relations {sup 1{minus}5} in binuclear copper(II) complexes, the authors have employed a binucleating ligand, LH, obtained by a Mannich reaction between a para-substituted phenol, formaldehye, and N-methylpiperazine{sup 6,7}. Molecular models are given which show that simultaneous coordination of the phenol oxygen and the four piperazine nitrogen atoms to two Cu(II) ions, in the presence of absence of an exogenous bridging ligand, would be difficult in view of the sterically constrained ligand conformation.

Bertoncello, K.; Fallon, G.D.; Hodgkin, J.H.; Murray, K.S. (Monash Univ., Clayton (Australia))

1988-12-28

388

A novel amalgamation of 1,2,3-triazoles, piperidines and thieno pyridine rings and evaluation of their antifungal activity.  

PubMed

It is the first report of the novel amalgamation of 1,2,3-triazoles, piperidines, thieno pyridine rings and evaluation of their antifungal activity. The synthesized compounds showed interesting moderate to good antifungal activity, wherein they were able to discriminate between the two species Aspergillus flavus and Aspergillus niger of the same genus. In addition, the main highlight of this series is the sensitivity of the fungal strain Cryptococcus neoformans to the compounds having p-chlorobenzoyl (9h), methane sulfonyl (9i) and p-methylbenzene sulfonyl (9j) attached to the piperazine nitrogen. PMID:23807083

Darandale, Sunil N; Mulla, Nayeem A; Pansare, Dattatraya N; Sangshetti, Jaiprakash N; Shinde, Devanand B

2013-05-20

389

MS377, a selective sigma receptor ligand, indirectly blocks the action of PCP in the N-methyl-D-aspartate receptor ion-channel complex in primary cultured rat neuronal cells  

Microsoft Academic Search

MS-377 ((R)-(+)-1-(4-chlorophenyl)-3-[4-(2-methoxyethyl)piperazin-1-yl]methyl-2-pyrrolidinone L-tartrate) is a antipsychotic agent that binds to sigma-1 receptor. MS-377 showed anti-dopaminergic and anti-serotonergic activities and antagonistic action against phencyclidine (PCP)-induced behaviors in an animal model. These anti-psychotic activities of MS-377 are attributable to association with sigma-1 receptor. However, the mechanism by which the sigma-1 receptor ligands exact those numerous effects remains to be elucidated. In the

Jun-ichi Karasawa; Hideko Yamamoto; Toshifumi Yamamoto; Naoki Sagi; Kazutoshi Horikomi; Ichiro Sora

2002-01-01

390

Binding properties of [ 3H]MS377, a novel ? receptor ligand, to rat brain membranes  

Microsoft Academic Search

MS-377 ((R)-(+)-1-(4-chlorophenyl)-3-[4-(2-methoxyethyl)piperazin-1-yl]methyl-2-pyrrolidinone l-tartrate) is a novel selective ? receptor ligand, currently being developed for the treatment of schizophrenia. MS-377 showed anti-phencyclidine (PCP), anti-dopaminergic and anti-serotonergic activities, and we anticipated that the anti-psychotic activities of MS-377 were associated with ?1 receptors. However, its pharmacological profile is partly distinct from those of selective ?1 receptor ligands. Thus, one of the possible speculations

Jun-ichi Karasawa; Shinji Takahashi; Kazutoshi Horikomi

2000-01-01

391

The synthesis of L-carvone and limonene derivatives with increased antiproliferative effect and activation of ERK pathway in prostate cancer cells.  

PubMed

Thirty-one novel derivatives of carvone, carveol, and limonene were designed and synthesized using L-carvone as a starting material via chlorination, nucleophilic substitution, and reduction. The structures of these derivatives were characterized by MS and 1H NMR. The antiproliferative effect was evaluated in human prostate cancer LNCaP cells. L-carvone, L-carveol, and L-limonene were weak cell growth inhibitors and introduction of 4-(2-methoxyphenyl)piperazine to carvone, carveol or limonene significantly increased their antiproliferative effect. The antiproliferative effect was correlated with ERK activation and p21(waf1) induction. PMID:16806947

Chen, Jiaojiao; Lu, Min; Jing, Yongkui; Dong, Jinhua

2006-06-27

392

Novel 5-HT2-like receptor mediates neurogenic relaxation of the guinea-pig proximal colon.  

PubMed

The aim of the current investigation was to characterize the 5-HT receptors that mediate neurogenic relaxation of the guinea-pig proximal colon. After blockade of 5-HT2A, 5-HT3 and 5-HT4 receptor-mediated contractions, 5-hydroxytryptamine (5-HT) induced relaxations yielding a biphasic concentration-response curve. Other tryptamines were also agonists with the following rank order of potency: 5-HT > 5-carboxamidotryptamine = 5-methoxytryptamine > or = alpha-methyl-5-HT (partial agonist) > tryptamine (partial agonist). 5-Hydroxytryptophan, 2-methyl-5-HT and N-methyltryptamine were virtually inactive as agonists. The curve to 5-HT was not affected by pargyline, citalopram, phentolamine, or by the 5-HT4 receptor antagonists 2-methoxy-4-amino-5-chloro-benzoic acid 2-(diethylamino)ethyl ester (SDZ 205-557) and (1-butyl-4-piperidinylmethyl)-8-amino-7-chloro-1,4-benzodioxan+ ++-5-carboxylate (SB 204070). 8-Hydroxy-2-(di-n-propylamino)-tetralin (8-OH-DPAT), 5-methoxy-3[1,2,3,6-tetrahydroxypyridin-4-yl]-1H-indole (RU 24969), 2-(2,6-dimethoxyphenoxyethyl)aminomethyl-1,4-benzodioxane (WB 4101), 1-(3-chlorophenyl)piperazine (mCPP), 1-(m-trifluoromethylphenyl)-piperazine (TFMPP), flesinoxan, sumatriptan and 6-chloro-2-(piperazinyl)-pyrazine (MK212) were inactive as 5-HT receptor agonists. The first phase of the curve to 5-HT was inhibited by: metergoline (pA2 = 8.8 +/- 0.3, against 5-methoxytryptamine 9.3 +/- 0.3), methysergide (non-surmountable), methiothepin (non-surmountable), spiroxatrine (non-surmountable), MK212 (non-surmountable), mesulergine (7.8 +/- 0.3), mCPP (7.1 +/- 0.1), mianserin (7.0 +/- 0.4), ritanserin (8.9 +/- 0.2), rauwolscine (7.0 +/- 0.2), yohimbine (6.2 +/- 0.2), 1-(1-naphthyl)-piperazine (7.7 +/- 0.2) and RU 24969 (6.4 +/- 0.1), but not by 1-(2-methoxyphenyl)4-[4-(2-phthalimidobtyl]-piperazine (NAN-190), spiperone, sumatriptan, 8-OH-DPAT and flesinoxan. It is suggested that the 5-HT receptor under study could be considered an unknown 5-HT2-like receptor. PMID:7556392

Briejer, M R; Akkermans, L M; Lefebvre, R A; Schuurkes, J A

1995-06-12

393

Characteristic fragmentation behaviors of novel dithiocarbamic acid esters studied by electrospray ionization tandem mass spectrometry  

NASA Astrophysics Data System (ADS)

The fragmentation patterns of a novel kind of dithiocarbamic acid esters with excellent anticancer activity were analyzed by positive ion electrospray ionization mass spectrometry in conjunction with tandem mass spectrometry (ESI/MSn). The fragmentation patterns of sodium adduct ions [M + Na]+ were characterized with elimination of hydrogen cyanide and most of their counterparts could be observed. The fragmentation patterns of protonated molecular ions [M + H]+ were characterized with single bond cleavage between thiocarbonyl group and nitrogen atom, and between thiocarbonyl group and sulfur atom. The piperazine moiety of the molecular of [M + H]+ favors a rearrangement to expel azirane, and the suggested rearrangement mechanism is consistent with experimental observations.

Hou, Xueling; Sha, Yaowu; Wang, Xin; Ge, Zemei; Li, Runtao

2005-12-01

394

Lurasidone hydro-chloride  

PubMed Central

In the crystal structure of the title compound, C28H37N4O2S+·Cl? [systematic name: 4-(1,2-benzothia­zol-3-yl)-1-({2-[(3,5-dioxo-4-aza­tricyclo­[5.2.1.02,6]decan-4-yl)meth­yl]cyclo­hex­yl}meth­yl)piperazin-1-ium chloride], the anions and cations are linked by N—H?Cl hydrogen bonds. The crystal structure is further stabilized by C—H?? and C—H?O inter­actions.

Zhang, Hua; Wang, Hubo; Zhu, Xueyan; Yuan, Zhedong; Jiang, Huijuan

2012-01-01

395

Search for a novel SIRT1 activator: structural modification of SRT1720 and biological evaluation.  

PubMed

Syntheses and biological evaluation of novel SRT1720 derivatives are described in search for new candidates of SIRT1 activator. Several parts of the SRT1720 structure, including piperazine moiety, quinoxaline ring on the amide group, and position of the amide function, were modified, and the assay results indicated that transfer of the ortho amide-substituent regarding to the imidazo[1,2-b]thiazole core onto the meta position resulted in improvement of SIRT1 activation ability. Modeling analyses of SRT1720 and the most potent derivative bound to model complex of SIRT1 with peptide substrate were also performed. PMID:23876989

Matsuya, Yuji; Kobayashi, Yuta; Uchida, Sayumi; Itoh, Yukihiro; Sawada, Hideyuki; Suzuki, Takayoshi; Miyata, Naoki; Sugimoto, Kenji; Toyooka, Naoki

2013-07-03

396

Agonist and Inverse Agonist Efficacy at Human Recombinant Serotonin 5HT 1A Receptors as a Function of Receptor:G-protein Stoichiometry  

Microsoft Academic Search

Membrane preparations were made from Chinese Hamster Ovary (CHO) cells expressing 1.6 and 4.2 pmol\\/mg of recombinant human 5-HT1A receptors, as determined by saturation binding with the selective antagonist, [3H]-S 15535 ([3H]-4-(benzodioxan-5-yl)1-(indan-2-yl)piperazine). There was no change in the number of G-proteins activated by the full agonist, serotonin (5-HT; approximately 1.1 pmol\\/mg in each preparation, measured by [35S]-GTP?S saturation binding), therefore

A NEWMAN-TANCREDI; C CONTE; C CHAPUT; L VERRIÈLE; M. J MILLAN

1997-01-01

397

Determining the subjective and physiological effects of BZP combined with TFMPP in human males  

Microsoft Academic Search

Rationale  ‘Party Pills’ containing benzylpiperazine (BZP) and trifluoromethylphenylpiperazine (TFMPP) have been used in a recreational\\u000a context since the 1990s and, prior to April 2008, were legally available in New Zealand. Taken together, they have been reported\\u000a to produce a ‘high’ similar to that produced by 3,4-methylenedioxymethamphetamine (MDMA).\\u000a \\u000a \\u000a \\u000a \\u000a Objectives  There has been little research on the subjective effects of piperazines in humans. The

Joanne C. Lin; Reem K. Jan; HeeSeung Lee; Maree-Ann Jensen; Rob R. Kydd; Bruce R. Russell

2011-01-01

398

Photoaffinity Label for the alpha 1-adrenergic Receptor: Synthesis and Effects on Membrane and Affinity-Purified Receptors  

Microsoft Academic Search

An azide analog, 2-[4-(4-azidobenzoyl)piperazin-1-yl]-4-amino-6,7-dimethoxyquinazoline (CP59,430), of the highly selective alpha 1-adrenergic receptor antagonist prazosin was synthesized and its effects on rat hepatic membrane and affinity-purified alpha 1-adrenergic receptor preparations were examined. CP59,430 behaved as a competitive antagonist before photolysis. When the membrane or purified preparations pretreated with CP59,430 were irradiated with UV light, CP59,430 behaved as a noncompetitive antagonist. Labeling

Hans-Jurgen Hess; Robert M. Graham; Charles J. Homcy

1983-01-01

399

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

400

Prophylactic and therapeutic effects of acute systemic injections of EMD 281014, a selective serotonin 2A receptor antagonist on anxiety induced by predator stress in rats  

Microsoft Academic Search

We examined the effect of the selective serotonin 2A (5-HT2A) receptor antagonist 7-[4-[2-(4-fluoro-phenyl)-ethyl]-piperazine-1-carbonyl]-1H-indole-3-carbon itrile HCl (EMD 281014) [Bartoszyk, G.D., van Amsterdam, C., Bottcher, H., Seyfried, C.A., 2003. EMD 281014, a new selective serotonin 5-HT2A receptor antagonist. Eur. J. Pharmacol. 473, 229–230.] on change in affect following predator stress. Predator stress involved a 5 min unprotected exposure of rats to a

Robert Adamec; Katherine Creamer; Gerd D. Bartoszyk; Paul Burton

2004-01-01

401

Cr(III), Fe(III) and Co(III) complexes of tetradentate (ONNO) Schiff base ligands: Synthesis, characterization, properties and biological activity  

Microsoft Academic Search

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, 1H-13C 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·nH2O, where M=Cr(III),

Eren Keskioglu; Ayla Balaban Gündüzalp; Servet Çete; Fatma Hamurcu; Birgül Erk

2008-01-01

402

Biocleavable Polycationic Micelles as Highly Efficient Gene Delivery Vectors  

NASA Astrophysics Data System (ADS)

An amphiphilic disulfide-containing polyamidoamine was synthesized by Michael-type polyaddition reaction of piperazine to equimolar N, N'-bis(acryloyl)cystamine with 90% yield. The polycationic micelles (198 nm, 32.5 mV), prepared from the amphiphilic polyamidoamine by dialysis method, can condense foreign plasmid DNA to form nanosized polycationic micelles/DNA polyelectrolyte complexes with positive charges, which transfected 293T cells with high efficiency. Under optimized conditions, the transfection efficiencies of polycationic micelles/DNA complexes are comparable to, or even higher than that of commercially available branched PEI (Mw 25 kDa).

Zhang, Min; Xue, Ya-Nan; Liu, Min; Zhuo, Ren-Xi; Huang, Shi-Wen

2010-11-01

403

Selective Killing of Bacterial Persisters by a Single Chemical Compound without Affecting Normal Antibiotic-Sensitive Cells?†  

PubMed Central

We show that 3-[4-(4-methoxyphenyl)piperazin-1-yl]piperidin-4-yl biphenyl-4-carboxylate (C10), screened out of a chemical library, selectively kills bacterial persisters that tolerate antibiotic treatment but does not affect normal antibiotic-sensitive cells. C10 led persisters to antibiotic-induced cell death by causing reversion of persisters to antibiotic-sensitive cells. This work is the first demonstration in which the eradication of bacterial persisters is based on single-chemical supplementation. The chemical should be versatile in elucidating the mechanism of persistence.

Kim, Jun-Seob; Heo, Paul; Yang, Tae-Jun; Lee, Ki-Sing; Cho, Da-Hyeong; Kim, Bum Tae; Suh, Ji-Hee; Lim, Hee-Jong; Shin, Dongwoo; Kim, Sung-Koo; Kweon, Dae-Hyuk

2011-01-01

404

Y-40138, a multiple cytokine production modulator, protects against d-galactosamine and lipopolysaccharide-induced hepatitis  

Microsoft Academic Search

Acute and fulminant liver failure induced by viral hepatitis, alcohol or other hepatotoxic drugs are associated with tumor necrosis factor (TNF) production. d-Galactosamine (D-GalN) and lipopolysaccharide (LPS)-induced liver injury is an experimental model of fulminant hepatic failure. In this model, TNF-? plays a central role in the pathogenesis of D-GalN\\/LPS-induced liver injury in mice. Y-40138, N-[1-(4-[4-(pyrimidin-2-yl)piperazin-1-yl]methyl phenyl)cyclopropyl] acetamide·HCl inhibits TNF-?

Tetsuko Fukuda; Akira Mogami; Hideki Tanaka; Tsutomu Yoshikawa; Masao Hisadome; Hirotsugu Komatsu

2006-01-01

405

Synthesis of a novel nitrogen-phosphorus flame retardant based on phosphoramidate and its application to PC, PBT, EVA, and ABS  

Microsoft Academic Search

A novel nitrogen-phosphorus compound, diphenyl piperazine-1,4-diylbis(methylphosphinate)(DPPMP) was synthesized via a two\\u000a step reaction and its flame retarding efficiency as a single component additive was investigated. The success of synthesis\\u000a was confirmed by FTIR and1H and31P NMR analysis. The product was mixed with polycarbonate (PC), poly(butylene terephtalate) (PBT), ethylene-vinyl-acetate copolymer\\u000a (EVA), and acrylonitrilebutadiene-styrene copolymer (ABS). The flame-retarding efficiency was evaluated using

Congtranh Nguyen; Jinhwan Kim

2008-01-01

406

SAR studies of pyridazinone derivatives as novel glucan synthase inhibitors.  

PubMed

A novel series of pyridazinone analogs has been developed as potent ?-1,3-glucan synthase inhibitors through structure-activity relationship study of the lead 5-[4-(benzylsulfonyl)piperazin-1-yl]-4-morpholino-2-phenyl-pyridazin-3(2H)-one (1). The effect of changes to the core structure is described in detail. Optimization of the sulfonamide moiety led to the identification of important compounds with much improved systematic exposure while retaining good antifungal activity against the fungal strains Candida glabrata and Candida albicans. PMID:21489787

Zhou, Gang; Ting, Pauline C; Aslanian, Robert; Cao, Jianhua; Kim, David W; Kuang, Rongze; Lee, Joe F; Schwerdt, John; Wu, Heping; Herr, R Jason; Zych, Andrew J; Yang, Jinhai; Lam, Sang; Wainhaus, Samuel; Black, Todd A; McNicholas, Paul M; Xu, Yiming; Walker, Scott S

2011-03-30

407

mCPP-induced anxiety in the light-dark box in rats – a new method for screening anxiolytic activity  

Microsoft Academic Search

The activity of anxiolytic and other drugs in a light-dark test situation was studied in rats treated with the anxiogenic\\u000a compound m-chlorophenyl-piperazine (mCPP). mCPP 0.5?mg\\/kg significantly diminished the exploratory activity of the animals in the light\\u000a compartment of the apparatus. Drugs to be tested against mCPP-induced anxiety when studied alone (not in combination with\\u000a mCPP) did not significantly alter the

A. Bilkei-Gorzó; I. Gyertyán; G. Lévay

1998-01-01

408

Simultaneous quantitative determination of amphetamines, ketamine, opiates and metabolites in human hair by gas chromatography/mass spectrometry.  

PubMed

A gas chromatography/mass spectrometry (GC/MS) method was developed and validated for the determination of common drugs of abuse in Asia. The method was able to simultaneously quantify amphetamines (amphetamine; AP, methamphetamine; MA, methylenedioxy amphetamine; MDA, methylenedioxymeth mphetamine; MDMA, methylenedioxy ethylamphetamine; MDEA), ketamine (ketamine; K, norketamine; NK), and opiates (morphine; MOR, codeine; COD, 6-acetylmorphine; 6-AM) in human hair. Hair samples (25 mg) were washed, cut, and incubated overnight at 25 degrees C in methanol/trifluoroacetic acid (methanol/TFA). The samples were extracted by solid-phase extraction (SPE), derivatized using heptafluorobutyric acid anhydride (HFBA) at 70 degrees C for 30 min, and the derivatives were analyzed by electron ionization (EI) GC/MS in selected ion monitoring mode. Confirmation was accomplished by comparing retention times and the relative abundances of selected ions with those of standards. Deuterated analogs of the analytes were used as internal standards for quantification. Calibration curves for ten analytes were established in the concentration range 0.1-10 ng/mg with high correlation coefficients (r2 > 0.999). The intra-day and inter-day precisions were within 12.1% and 15.8%, respectively. The intra-day and inter-day accuracies were between -8.7% and 10.7%, and between -5.9% and 13.8%, respectively. The limit of detection (LOD) and limit of quantification (LOQ) obtained were 0.03 and 0.05 ng/mg for AP, MA, MDA, MDMA and MDEA; 0.05 and 0.08 ng/mg for K, NK, MOR and COD; and 0.08 and 0.1 ng/mg for 6-AM. The recoveries were above 88.6% for all the compounds, except K and NK which were in the range of 71.7-72.7%. Eight hair samples from known polydrug abusers were examined by this method. These results show that the method is suitable for broad-spectrum drug testing in a single hair specimen. PMID:18288687

Wu, Ya-Hsueh; Lin, Keh-Liang; Chen, Su-Chin; Chang, Yan-Zin

2008-01-01

409

Synthesis and characterization of a new open-framework fluorinated gallium phosphite with three-dimensional intersecting channels  

SciTech Connect

N{sub 2}H{sub 12})[Ga{sub 2}F{sub 3}(HPO{sub 3}){sub 2}(H{sub 2}PO{sub 3})] 1 is a new open-framework fluorinated gallium phosphite obtained by mild hydrothermal synthesis using piperazine as template agent and characterized by single crystal X-ray diffraction (XRD), powder XRD, infra-red spectroscopy, inductively coupled plasma, thermogravimetric and elemental analyses. The three-dimensional (3D) anionic framework of compound 1 is constructed from two distinct motifs, a 1D tancoite chain and a single 4-ring (S4R) unit, which contains four intersecting channels running throughout the structure as 8, 12-member rings channels along to the a-axis and 12-member ring channels along the b- and c-axis, respectively. The well-ordered, diprotonated piperazine cations occupy all the channels, and interact with the fluorinated gallium-phosphite framework by strong hydrogen bonds. - Graphical abstract: (C{sub 4}N{sub 2}H{sub 12})[Ga{sub 2}F{sub 3}(HPO{sub 3}){sub 2}(H{sub 2}PO{sub 3})] 1 is a new open-framework fluorinated gallium phosphite with four intersecting channels running throughout the structure as 8, 12-member ring channels along to the a-axis and 12-member ring channels along the b- and c-axis, respectively.

Wang Li [Key Laboratory of Inorganic Synthesis and Preparative Chemistry, Department of Chemistry, Jilin University, Changchun 130012 (China); Song Tianyou [Key Laboratory of Inorganic Synthesis and Preparative Chemistry, Department of Chemistry, Jilin University, Changchun 130012 (China); Fan Yong [Key Laboratory of Inorganic Synthesis and Preparative Chemistry, Department of Chemistry, Jilin University, Changchun 130012 (China); Tian Zhenfen [Key Laboratory of Inorganic Synthesis and Preparative Chemistry, Department of Chemistry, Jilin University, Changchun 130012 (China); Wang Ying [Key Laboratory of Inorganic Synthesis and Preparative Chemistry, Department of Chemistry, Jilin University, Changchun 130012 (China); Shi Suhua [Key Laboratory of Inorganic Synthesis and Preparative Chemistry, Department of Chemistry, Jilin University, Changchun 130012 (China)]. E-mail: shish@mail.jlu.edu.cn; Xu Jianing [Key Laboratory of Inorganic Synthesis and Preparative Chemistry, Department of Chemistry, Jilin University, Changchun 130012 (China)

2006-11-15

410

Olanzapinium dipicrate  

PubMed Central

The asymmetric unit of the title salt [systematic name: 2-methyl-4-(4-methyl­piperazin-4-ium-1-yl)-10H-thieno[2,3-b][1,5]benzodiazepinium bis­(2,4,6-trinitro­phenolate)], C17H22N4S2+·2C6H2N3O7 ?, consists of a diprotonated olanzapinium cation and two independent picrate anions. In the cation, the piperazine ring adopts a distorted chair conformation and contains a positively charged N atom with quaternary character and the N atom in the seven-membered 1,5-diazepine ring, which adopts a boat configuration, is also protonated. The dihedral angle between the benzene and thiene rings flanking the diazepine ring is 58.8?(1)°. In one of the picrate anions, a nitro group is disordered over two sets of sites in a 0.748?(5):0.252?(5) ratio, and the benzene ring has a flat envelope conformation with the O? C atom displaced from the mean plane of the other five C atoms [maximum deviation 0.0151?(14)?Å] by 0.1449?(14)?Å. In the crystal, N—H?O hydrogen bonds and weak inter­molecular C—H?S and C—H?O inter­actions link the components, forming a three-dimensional network.

Kavitha, C. N.; Jasinski, Jerry P.; Keeley, Amanda C.; Yathirajan, H. S.; Dayananda, A. S.

2013-01-01

411

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

2012-10-22

412

Identification of biotransformation products of macrolide and fluoroquinolone antimicrobials in membrane bioreactor treatment by ultrahigh-performance liquid chromatography/quadrupole time-of-flight mass spectrometry.  

PubMed

Ultrahigh-performance liquid chromatography coupled to quadrupole time-of-flight mass spectrometry was applied for the identification of transformation products (TPs) of fluoroquinolone (norfloxacin and ciprofloxacin) and macrolide (azithromycin, erythromycin, and roxitromycin) antimicrobials in wastewater effluents from a Zenon hollow-fiber membrane bioreactor (MBR). The detected TPs were thoroughly characterized using the accurate mass feature for the determination of the tentative molecular formulae and MS-MS experiments for the structural elucidation of unknowns. Several novel TPs, which have not been previously reported in the literature, were identified. The TPs of azithromycin and roxithromycin, identified in MBR effluent, were conjugate compounds, which were formed by phosphorylation of desosamine moiety. Transformation of fluoroquinolones yielded two types of products: conjugates, formed by succinylation of the piperazine ring, and smaller metabolites, formed by an oxidative break-up of piperazine moiety to form the 7-[(2-carboxymethyl)amino] group. A semi-quantitative assessment of these TPs suggested that they might have contributed significantly to the overall balance of antimicrobial residues in MBR effluents and thus to the overall removal efficiency. Determination of TPs during a period of 2 months indicated a conspicuous dynamics, which warrants further research to identify microorganisms involved and treatment conditions leading to their formation. PMID:21553354

Terzic, Senka; Senta, Ivan; Matosic, Marin; Ahel, Marijan

2011-05-10

413

The stability of four designer drugs: MDPV, mephedrone, BZP and TFMPP in three biological matrices under various storage conditions.  

PubMed

The analysis of designer drugs, including those in the synthetic cathinone and piperazine classes, may be complicated by the poor stability of these compounds in biological specimens. The stability of four of these compounds was investigated: 3,4-methylenedioxypyrovalerone, 4-methyl-N-methylcathinone (mephedrone), N-benzylpiperazine and 1-[3-(trifluoromethyl)phenyl]piperazine. Compound stability was monitored in three different biological matrices when each matrix was stored under three different conditions. These matrices and conditions included human whole blood, human serum and human urine, each stored at -20, 4 and 22°C for a period of 14 days in the dark in a sealed glass container. Analysis by liquid chromatography-tandem mass spectrometry was performed on Day 1 to establish the initial concentration for each drug in each specimen type, and then the samples were divided into three parts for storage under the various conditions. Analysis was performed in triplicate on Days 2, 4, 7 and 14 for each specimen type under each storage condition and the results were compared to those obtained on Day 1. Following analysis of the data, it became clear that mephedrone was not stable, and that care must be taken following specimen receipt to ensure minimal degradation. PMID:23325764

Johnson, Robert D; Botch-Jones, Sabra R

2013-01-16

414

Towards metabolically stable 5-HT7 receptor ligands: a study on 1-arylpiperazine derivatives and related isosters.  

PubMed

Serotonin 7 (5-hydroxytryptamine7 or 5-HT7) is the most recently identified serotonin receptor. It is involved in mood disorders and is studied as a target for antidepressants. Here, we report on the structural manipulation of the 5-HT7 receptor ligand 4-[2-(3-methoxyphenyl)ethyl]-1-(2-methoxyphenyl)piperazine (1a) aimed at obtaining 5-HT7 receptor ligands endowed with good in vitro metabolic stability. A set of N-[3-methoxyphenyl)ethyl-substituted] 1-arylpiperazine, 4-arylpiperidine and 1-aryl-4-aminopiperidine was synthesized and tested in radioligand binding assays at human cloned 5-HT7 and 5-HT1A receptors. In vitro metabolic stability of the target compounds was assessed after incubation with rat hepatic S9 microsomal fraction. Among the new compounds, 1-(2-biphenyl)-4-[2-(3-methoxyphenyl)ethyl]piperazine (1d) and 4-(2-biphenyl)-1-[2-(3-methoxyphenyl)ethyl]piperidine (2d) showed a good compromise between affinity at 5-HT7 receptor (K i = 7.5 nM and 13 nM, respectively) and in vitro metabolic stability (26 and 65 % recovery of parent compound, respectively) but were poorly selective over 5-HT1A receptor. PMID:23571499

Lacivita, Enza; De Giorgio, Paola; Patarnello, Daniela; Niso, Mauro; Colabufo, Nicola A; Berardi, Francesco; Perrone, Roberto; Satala, Grzegorz; Duszynska, Beata; Bojarski, Andrzej J; Leopoldo, Marcello

2013-04-10

415

Synthesis and Pharmacological Evaluation of Fluorine Containing D3 Dopamine Receptor Ligands  

PubMed Central

A series of fluorine containing N-(2-methoxyphenyl)piperazine and N-(2-fluoroethoxy)piperazine analogues were synthesized and their affinities for human dopamine D2, D3 and D4 receptors were determined. Radioligand binding studies identified five compounds, 18a, 20a, 20c, 20e and 21e, which bind with high affinity at D3 (Ki = 0.17 to 5 nM) and moderate to high selectivity for D3 vs. D2 receptors (ranging from ?25 to 163-fold). These compounds were also evaluated for intrinsic activity at D2 and D3 receptors using a forskolin-dependent adenylyl cyclase assay. This panel of compounds exhibits varying receptor subtype binding selectivity and intrinsic activity at D2 vs. D3 receptors. These compounds may be useful for behavioral pharmacology studies on the role of D2-like dopamine receptors in neuropsychiatric and neurological disorders. Furthermore, compound 20e, which has the highest binding affinity and selectivity for the D3 receptor (Ki = 0.17 nM for D3, 163-fold selectivity for D3 vs. D2 receptors) represents a candidate fluorine-18 radiotracer for in vivo PET imaging studies on the regulation of D3 receptor expression.

Tu, Zhude; Li, Shihong; Cui, Jinquan; Xu, Jinbin; Taylor, Michelle; Ho, David; Luedtke, Robert R.; Mach, Robert H.

2011-01-01

416

Buffers in daphnid culture and bioassay  

SciTech Connect

When an algal diet is employed, or precipitation of dissolved inorganics during autoclaving is likely, or test circumstances introduce pH changes, addition of a buffer to daphnid culture or bioassay media is appropriate. Glycylglycine, employed in this research for 20 years, is unsuitable for general use because it required microbe-free cultures. In contrast, n-hydroxyethyl piperazine-n-2-propane sulfonic acid (HEPPSO) and N-2-hydroxyethyl piperazine-N{prime}-2-ethane sulfonic acid (HEPES) offer safe and effective pH control at 300 ppm for animals, 400 ppm for algae (weight excludes Na), with no requirement for microbe-free cultures. No negative effects on fecundity, monitored in both single and multigeneration tests, or on vigor, measured by acute bioassay performance, were observed. The 48-h LC50 for glycylglycine is approximately 4,500 ppm. No deaths occur at or below 10,000 ppm of either HEPES or HEPPSO. When bioassayed against zinc (as chloride), animals reared in cultures buffered by HEPES, HEPPSO, or glycylglycine and tested in unfed acute bioassays performed similarly, allowing 100% survival in 1,000 ppb in 48 h with an CL50 of approximately 1,750 ppb.

Keating, K.I.; Caffrey, P.B.; Dagbusan, B.C. [Rutgers-the State Univ., New Brunswick, NJ (United States). Dept. of Environmental Science

1996-03-01

417

Effects of serotonin and serotonin analogs on posture and agonistic behavior in crayfish.  

PubMed

Exogenous serotonin has been shown to induce an elevated, flexed posture in crustaceans and has also been hypothesized to enhance aggressive behavior. We conducted three experiments to further investigate the effects of serotonin and serotonin analogs on posture and agonistic behavior in the crayfish Procambarus clarkii. In the first experiment, we recorded behavioral responses to five different concentrations of serotonin injected into the ventral hemolymph sinus. The amine elicited a series of behaviors including the characteristic high, flexed posture, but none were clearly associated with aggression. In our second experiment, we tested serotonin and four serotonin receptor agonists [1-(3-chlorophenyl)piperazine dihydrochloride, 2-methyl-5-hydroxytryptamine maleate, 5-carboxamidotryptamine maleate and alpha-methyl-5-hydroxytryptamine maleate] and measured the ability of each agonist to mimic the actions of the amine. High concentrations of 1-(3-chlorophenyl)piperazine dihydrochloride most closely mimicked the actions of serotonin; 5-carboxamidotryptamine maleate induced a high stance, but did not otherwise induce effects similar to serotonin. In our third experiment, we conducted an analysis of fighting behavior between pairs of crayfish that had received injections of control saline, serotonin, or 5-carboxamidotryptamine maleate. Serotonin generally reduced the level of aggression between opponents, whereas 5-carboxamidotryptamine maleate enhanced the performance of several agonistic behaviors. PMID:11800033

Tierney, A J; Mangiamele, L A

2001-12-01

418

Discovery of N-{4-[(3-hydroxyphenyl)-3-methylpiperazin-1-yl]methyl-2-methylpropyl}-4-phenoxybenzamide analogues as selective kappa opioid receptor antagonists.  

PubMed

There is continuing interest in the discovery and development of new ? opioid receptor antagonists. We recently reported that N-substituted 3-methyl-4-(3-hydroxyphenyl)piperazines were a new class of opioid receptor antagonists. In this study, we report the syntheses of two piperazine JDTic-like analogues. Evaluation of the two compounds in an in vitro [(35)S]GTP?S binding assay showed that neither compound showed the high potency and ? opioid receptor selectivity of JDTic. A library of compounds using the core scaffold 21 was synthesized and tested for their ability to inhibit [(35)S]GTP?S binding stimulated by the selective ? opioid agonist U69,593. These studies led to N-[(1S)-1-{[(3S)-4-(3-hydroxyphenyl)-3-methylpiperazin-1-yl]methyl}-2-methylpropyl]-4-phenoxybenzamide (11a), a compound that showed good ? opioid receptor antagonist properties. An SAR study based on 11a provided 28 novel analogues. Evaluation of these 28 compounds in the [(35)S]GTP?S binding assay showed that several of the analogues were potent and selective ? opioid receptor antagonists. PMID:23651437

Kormos, Chad M; Jin, Chunyang; Cueva, Juan Pablo; Runyon, Scott P; Thomas, James B; Brieaddy, Lawrence E; Mascarella, S Wayne; Navarro, Hernán A; Gilmour, Brian P; Carroll, F Ivy

2013-05-16

419

Pharmacological evaluation of halogenated and non-halogenated arylpiperazin-1-yl-ethyl-benzimidazoles as D(2) and 5-HT(2A) receptor ligands.  

PubMed

Five groups of previously synthesized and initially screened non-substituted and 4-halogenated arylpiperazin-1-yl-ethyl-benzimidazoles were estimated for their in-vitro binding affinities at the rat D(2) , 5-HT(2A) , and ?(1) -adrenergic receptors. Among all these compounds, 2-methoxyphenyl and 2-chlorophenyl piperazines demonstrate the highest affinities for the tested receptors. The effects of 4-halogenation of benzimidazoles reveal that substitution with bromine may greatly increase the affinity of the compounds for the studied receptors, while the effect of substitution with chlorine is less remarkable. Most of the tested components show 5-HT(2A)/D(2) pK(i) binding ratios slightly above or less than 1, while only 4-chloro-6-(2-{4-[3-(trifluoromethyl)phenyl]piperazin-1-yl}ethyl)-1H-benzimidazole expresses an appropriate higher binding ratio (1.14), which was indicated for atypical neuroleptics. This compound exhibits a non-cataleptic action in rats and prevents d-amphetamine-induced hyperlocomotion in mice, which suggest its atypical antipsychotic potency. PMID:21509803

Tomi?, Mirko; Vaskovi?, Djurdjica; Tovilovi?, Gordana; Andri?, Deana; Penjiševi?, Jelena; Kosti?-Raja?i?, Sladjana

2011-02-14

420

Cinnarizinium bis-(p-toluene-sulfonate) dihydrate  

PubMed Central

The asymmetric unit of the title salt [systematic name: 1-benzhydryl-4-cinnamylpiperazine-1,4-diium bis­(p-toluene­sulfonate) dihydrate], C26H30N2 2+·2C7H7O3S?·2H2O, consists of a diprotonated cinnarizinium cation hydrogen bonded through two water mol­ecules to two independent p-toluene­sulfonate anions, one which is disordered over two sets of sites in a 0.793?(3):0.207?(3) ratio. In the cation, the piperazine ring adopts a chair configuration and contains two positively charged N atoms with quarternery character. The dihedral angle between the two benzene rings in the benzhydr­yl group is 71.8?(1)°. The benzene ring flanked opposite the piperazine ring is twisted by 75.9?(9) and 8.8?(3)° from these two benzene rings. In the crystal, the [N—H?Owater—H?O( S)]2 hydrogen-bonded asymmetric unit is connected by further O—H?O hydrogen bonds linking the components into chains along [100].

Kavitha, C. N.; Butcher, Ray J.; Jasinski, Jerry P.; Yathirajan, H. S.; Dayananda, A. S.

2013-01-01

421

Spectroscopic study of degradation products of ciprofloxacin, norfloxacin and lomefloxacin formed in ozonated wastewater.  

PubMed

This study addressed the formation and properties of degradation products of ciprofloxacin, norfloxacin and lomefloxacin formed during ozonation of secondary wastewater effluent containing these fluoroquinolone antibiotics. The generation of the degradation products was interpreted in the context of transformations of effluent organic matter (EfOM) tracked via absorbance measurements. The structures of 20 degradation products were elucidated for ciprofloxacin and norfloxacin, respectively. 27 degradation products were identified for lomefloxacin. The prevalent oxidation pathways were suggested based on the structures of the identified products formed in the absence and presence of the hydroxyl radical scavenger t-butanol. These pathways were largely similar for all studied fluoroquinolones and involved attacks on the piperazine ring and the quinolone structure. The quinolone ring remained intact in the presence of t-butanol thus indicating that this functional group could only be oxidized by OH radicals while the piperazine ring was readily oxidized by molecular ozone. The cleavage of the quinolone moiety that resulted in several identified degradation products occurred via the attack by hydroxyl radicals on the carbon-carbon double bond adjacent to the carboxylic acid group. Lomefloxacin had more diverse oxidation products due to the presence of a methyl group on its piperazinyl ring. The concentrations of the identified degradation products behaved non-monotonically as a function of ozone dose or treatment time, yet exhibited interpretable correlations versus changes of EfOM absorbance. Examination of these correlations allowed developing a novel approach for elucidating the transformations of fluoroquinolone antibiotics during ozonation. PMID:22863026

Liu, Chen; Nanaboina, Venkateswarlu; Korshin, Gregory V; Jiang, Wenju

2012-07-20

422

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.

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

423

Cr(III), Fe(III) and Co(III) complexes of tetradentate (ONNO) Schiff base ligands: Synthesis, characterization, properties and biological activity  

NASA Astrophysics Data System (ADS)

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, 1H- 13C 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 2O, 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 2O) 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.

Keskio?lu, Eren; Gündüzalp, Ayla Balaban; Çete, Servet; Hamurcu, Fatma; Erk, Birgül

2008-08-01

424

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

425

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

426

Comparing selective H/sub 2/S removal methods in CO/sub 2/ floods  

SciTech Connect

Presents case studies of processes chosen for H/sub 2/S removal, focusing on decision-driving criteria. Emphasizes that the criteria (ethane recovery incentive, fuel gas cost, capital available, and use of existing NGL plant) are not the only important variables to be considered in determining process selections and overall facility designs. H/sub 2/S content of the associated gas stream is typically about 3% at the beginning of the project, and is projected to decrease to about 0.5% at some point in time during the flood. Processes chosen for study are Benfield or Sulfinol gas treating with MDEA selective H/sub 2/S removal from CO/sub 2/ product stream; sour NGL recovery pretreatment plus Selexol selective H/sub 2/S removal from processed gas stream; Ryan/Holmes cryogenic fractionation processes plus DEA NGL product treating; and Benfield gas treating followed by Selexol selective H/sub 2/S removal from CO/sub 2/ product stream. Concludes that the variables discussed here seem to be the decision-driving forces that change most frequently between projects in this area.

Laengrich, A.; Carlisle, K.; Harmon, C.

1982-08-01

427

Hair analysis: self-reported use of "speed" and "ecstasy" compared with laboratory findings.  

PubMed

Drug use histories were collected from 100 subjects recruited from the "dance scene" in and around Glasgow, Scotland. In addition, each subject donated a hair sample which was analyzed by gas chromatography/mass spectrometry (GC/MS) for amphetamine (AP), methamphetamine (MA), 3,4-methylenedioxyamphetamine (MDA), 3,4-methylenedioxymethamphetamine (MD MA) and 3,4-methylenedioxyethylamphetamine (MDEA). The hair samples were analyzed in two 6 cm segments or in full, ranging from 1.5 to 12 cm depending on the length of the hair. Approximately 10 mg of hair was ground to a fine powder before treatment with beta-glucuronidase/aryl sulfatase. A solid-phase extraction procedure was carried out followed by derivatization with pentafluoropropionic anhydride (PFPA). All extracts were analyzed by gas chromatography/mass spectrometry (GC/MS). Of the 139 segments analyzed, 77 (52.5%) were positive for at least one of the five amphetamines. The drug concentrations found in the hair were compared with the self-reported drug histories. A concordance of greater than 50% was found between the self-report data and levels detected in hair. However, no correlation was found between the reported number of "ecstasy" tablets consumed and the drug levels detected in hair. An increase in the average drug levels measured was observed from low to high use (number of "ecstasy" tablets/month). A large number of false negatives and a low number of false positives were observed. PMID:10782961

Cooper, G A; Allen, D L; Scott, K S; Oliver, J S; Ditton, J; Smith, I D

2000-03-01

428

Development of Fluorescent Polymerization-based Signal Amplification for Sensitive and Non-enzymatic Biodetection in Antibody Microarrays  

PubMed Central

Antibody microarrays are a critical tool for proteomics, requiring broad, highly sensitive detection of numerous low abundance biomarkers. Fluorescent polymerization-based amplification (FPBA) is presented as a novel, non-enzymatic signal amplification method that takes advantage of the chain-reaction nature of radical polymerization to achieve a highly amplified fluorescent response. A streptavidin-eosin conjugate localizes eosin photoinitiators for polymerization on the chip where biotinylated target protein is bound. The chip is contacted with acrylamide as a monomer, N-methyldiethanolamine as a coinitiator and yellow/green fluorescent nanoparticles (NPs) which, upon initiation, combine to form a macroscopically visible and highly fluorescent film. The rapid polymerization kinetics and the presence of cross-linker favor entrapment of the fluorescent NPs in the polymer, enabling highly sensitive fluorescent biodetection. This method is demonstrated as being appropriate for antibody microarrays and is compared to detection approaches which utilize streptavidin-FITC (SA-FITC) and streptavidin-labeled yellow/green NPs (SA-NPs). It is found that FPBA is able to detect 0.16 (+/? 0.01) biotin-antibody/µm2 (or 40 zeptomole surface-bound target molecules), while SA-FITC has a limit of detection of 31 (+/? 1) biotin-antibody/µm2 and SA-NPs fail to achieve any significant signal under the conditions evaluated here. Further, FPBA in conjunction with fluorescent stereomicroscopy yields equal or better sensitivity compared to fluorescent detection of SA-eosin using a much more costly microarray scanner. By facilitating highly sensitive detection, FPBA is expected to enable detection of low abundance antigens and also make possible a transition towards less expensive fluorescence detection instrumentation.

Avens, Heather J.; Bowman, Christopher N.

2009-01-01

429

Bifunctional mesoporous zirconium phosphonates for delivery of nucleic acids.  

PubMed

The bifunctional mesoporous zirconium phosphonates (ZrBFs) were synthesized through surfactant-assisted co-condensation of ZrCl(4) with two different phosphonic acids, both 1-phosphomethylproline (H(3)PMP) and 1,4-bis(phosphomethyl)piperazine (BPMP), in a one-pot procedure. The L-proline group of H(3)PMP and piperazine group of BPMP in the frameworks endow ZrBFs with pH-controllable release function and high cell penetration capability, which was derived from the reversible protonation-deprotonation of L-proline groups and piperazine groups on the mesoporous walls under different pH values (pH sensitivity) as well as further functionalization with biological modifiers via the carboxyls in L-proline groups on the outer surface (functionalizability), respectively. ZrBFs, possessing cationic frameworks once formed, exhibit high payload for salmon sperm DNA as model nucleic acid owing to strong electrostatic attraction between them. On the basis of pH-sensitive ZrBFs carriers and assisted by lag-time films coating, the time- and pH-controlled oral colon-targeted nucleic acid delivery systems have been developed, which can carry most of the loaded salmon sperm DNA to the colon under dual control, time control and pH value control. Furthermore, salmon sperm DNA can remain intact during delivery, as evidenced by the fact that the released salmon sperm DNA in the pH transition release experiment still retain its structural integrity and native conformation. Also, fluorescence spectra demonstrate that ZrBFs can be further functionalized with a cell-penetrating peptide of octaarginine (R8) via the carboxyls in L-proline groups of H(3)PMP on the outer surface using a coupling agent, which will enhance the penetration capability of ZrBFs through biomembranes. ZrBFs have a potential application as a new kind of carrier in oral delivery of nucleic acids targeting the colon for gene therapy of colon-related diseases due to their unique bifunctionality. PMID:23347141

Tang, Yan; Ren, Yubao; Shi, Xin

2013-01-24

430

Influence of Cocaine History on the Behavioral Effects of Dopamine D3 Receptor-Selective Compounds in Monkeys  

PubMed Central

Although dopamine D3 receptors have been associated with cocaine abuse, little is known about the consequences of chronic cocaine on functional activity of D3 receptor-preferring compounds. This study examined the behavioral effects of D3 receptor-selective 4-phenylpiperazines with differing in vitro functional profiles in adult male rhesus monkeys with a history of cocaine self-administration and controls. In vitro assays found that PG 619 (N-(3-hydroxy-4-(4-(2-methoxyphenyl)piperazin-1-yl)butyl)-4-(pyridin-2-yl)benzamide HCl) was a potent D3 antagonist in the mitogenesis assay, but a fully efficacious agonist in the adenylyl cyclase assay, NGB 2904 (N-(4-(4-(2,3-dichlorophenyl)piperazin-1-yl)butyl)-9H-fluorene-2-carboxamide HCl) was a selective D3 antagonist, whereas CJB 090 (N-(4-(4-(2,3-dichlorophenyl)piperazin-1-yl)butyl)-4-(pyridin-2-yl)benzamide HCl) exhibited a partial agonist profile in both in vitro assays. In behavioral studies, the D3 preferential agonist quinpirole (0.03–1.0?mg/kg, i.v.) dose-dependently elicited yawns in both groups of monkeys. PG 619 and CJB 090 elicited yawns only in monkeys with an extensive history of cocaine, whereas NGB 2904 did not elicit yawns, but did antagonize quinpirole and PG 619-elicited yawning in cocaine-history monkeys. In another experiment, doses of PG 619 that elicited yawns did not alter response rates in monkeys self-administering cocaine (0.03–0.3?mg/kg per injection). Following saline extinction, cocaine (0.1?mg/kg) and quinpirole (0.1?mg/kg), but not PG 619 (0.1?mg/kg), reinstated cocaine-seeking behavior. When given before a cocaine prime, PG 619 decreased cocaine-elicited reinstatement. These findings suggest that (1) an incongruence between in vitro and in vivo assays, and (2) a history of cocaine self-administration can affect in vivo efficacy of D3 receptor-preferring compounds PG 619 and CJB 090, which appear to be dependent on the behavioral assay.

Blaylock, B L; Gould, R W; Banala, A; Grundt, P; Luedtke, R R; Newman, A H; Nader, M A

2011-01-01

431

Photoaffinity labeling of the. cap alpha. /sub 1/-adrenergic receptor using an /sup 125/I-labeled aryl azide analogue of prazosin. [Rats  

SciTech Connect

..cap alpha../sub 1/-Adrenergic receptor probes, which can be radioiodinated to yield high specific activity radioligands, have been synthesized and characterized. 2-(4-(4-Amino-benzoyl)piperazin-1-yl)-4-amino-6,7-dimethoxyquinazoline (CP63,155), an arylamine analogue of the selective ..cap alpha../sub 1/-adrenergic antagonist prazosin, and its iodinated derivative, 2-(4-(4-amino-3-(/sup 125/I)iodobenzoyl)piperazin-1-yl)-4-amino-6,7-dimethoxyquinazoline ((/sup 125/I)CP63,789), bind reversibly and with high affinity (K/sub D/ = 1 nM and 0.6 nM, respectively) to rat hepatic membrane ..cap alpha../sub 1/-adrenergic receptors. Conversion of (/sup 125/I)CP63,789 to the aryl azide yields a photolabile derivative, 2-(4-(4-azido-3-(/sup 125/I)iodobenzoyl)piperazin-1-yl)-4-amino-6,7-dimethoxyquinazoline ((/sup 125/I)CP65,526), which prior to photolysis binds competitively and with high affinity (K/sub D/ = 0.3 nM). Binding of (/sup 125/I)CP63,789 and (/sup 125/I)CP65,526 (prior to photolysis) is rapid and saturable. Both ligands identify similar ..cap alpha../sub 1/-adrenergic receptor binding site concentrations as the parent probe, (/sup 3/H)prazosin. Specific binding by these iodinated ligands is stereoselective and inhibited by a variety of adrenergic agents with a specificity typical of the ..cap alpha../sub 1/-adrenergic receptor. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and autoradiography of (/sup 125/I)CP65,526-labeled rat hepatic membranes reveal major protein species with molecular weights of 77K, 68K and 59K. Each protein binds adrenergic ligands with stereoselectivity and with a specificity typical of the ..cap alpha../sub 1/-adrenergic receptor. Smaller peptides with molecular weights of 42K and 31K display prazosin-inhibitable (/sup 125/I)CP65,526 binding. Labeling of these protein species with (/sup 125/I)CP65,526 is not inhibitable by other adrenergic agonists or antagonists. They are thus unlikely to represent subunits of the receptor.

Seidman, C.E.; Hess, H.J.; Homcy, C.J.; Graham, R.M.

1984-07-31

432

Influence of cocaine history on the behavioral effects of Dopamine D(3) receptor-selective compounds in monkeys.  

PubMed

Although dopamine D(3) receptors have been associated with cocaine abuse, little is known about the consequences of chronic cocaine on functional activity of D(3) receptor-preferring compounds. This study examined the behavioral effects of D(3) receptor-selective 4-phenylpiperazines with differing in vitro functional profiles in adult male rhesus monkeys with a history of cocaine self-administration and controls. In vitro assays found that PG 619 (N-(3-hydroxy-4-(4-(2-methoxyphenyl)piperazin-1-yl)butyl)-4-(pyridin-2-yl)benzamide HCl) was a potent D(3) antagonist in the mitogenesis assay, but a fully efficacious agonist in the adenylyl cyclase assay, NGB 2904 (N-(4-(4-(2,3-dichlorophenyl)piperazin-1-yl)butyl)-9H-fluorene-2-carboxamide HCl) was a selective D(3) antagonist, whereas CJB 090 (N-(4-(4-(2,3-dichlorophenyl)piperazin-1-yl)butyl)-4-(pyridin-2-yl)benzamide HCl) exhibited a partial agonist profile in both in vitro assays. In behavioral studies, the D(3) preferential agonist quinpirole (0.03-1.0?mg/kg, i.v.) dose-dependently elicited yawns in both groups of monkeys. PG 619 and CJB 090 elicited yawns only in monkeys with an extensive history of cocaine, whereas NGB 2904 did not elicit yawns, but did antagonize quinpirole and PG 619-elicited yawning in cocaine-history monkeys. In another experiment, doses of PG 619 that elicited yawns did not alter response rates in monkeys self-administering cocaine (0.03-0.3?mg/kg per injection). Following saline extinction, cocaine (0.1?mg/kg) and quinpirole (0.1?mg/kg), but not PG 619 (0.1?mg/kg), reinstated cocaine-seeking behavior. When given before a cocaine prime, PG 619 decreased cocaine-elicited reinstatement. These findings suggest that (1) an incongruence between in vitro and in vivo assays, and (2) a history of cocaine self-administration can affect in vivo efficacy of D(3) receptor-preferring compounds PG 619 and CJB 090, which appear to be dependent on the behavioral assay. PMID:21289600

Blaylock, B L; Gould, R W; Banala, A; Grundt, P; Luedtke, R R; Newman, A H; Nader, M A

2011-02-02

433

Antibodies to diethylcarbamazine potentiate the antifilarial activity of the drug.  

PubMed

The antifilarial drug diethylcarbamazine citrate (DEC) is known to mediate in vivo microfilaricidal activity in conjunction with the host immune system. In this study passive transfer of antibodies to DEC elicited by immunization with methyl piperazine carboxylic acid (MPCA) coupled to bovine serum albumin (BSA), was found to potentiate microfilaricidal activity of subcurative doses of DEC in Setaria digitata infected Mastomys coucha. Active immunization of microfilaraemic animals with MPCA-BSA followed by administration of subcurative doses of DEC also resulted in rapid clearance of microfilaraemia in both S. digitata and Brugia malayi infected M. coucha indicating the synergistic activity of DEC and the antibodies to the drug. Since some of the filarial antibodies are known to react with DEC, it is proposed that such antibodies may potentiate the microfilaricidal activity of the drug in vivo. PMID:9149286

Mukhopadhyay, S; Ravindran, B

1997-04-01

434

Crystallographic and magnetic properties of fine iron nitride powders prepared by solid state reactions between iron and organic H{sub x}(CN)-ring compounds  

SciTech Connect

In this work morphological, crystallographic and magnetic properties of iron nitride powders prepared by room temperature mechano-chemical processing, were studied by SEM, XRD and VSM methods. Nitridation reaction occurs during ball milling of a stoichiometric mixture of {alpha}Fe powder and highly reactive complex amine compounds: piperazine, pyrazine and pyrazole in the molar ratio 3:1 (Fe:N). The amount of nitride phase produced, depends on milling time, annealing temperature and on the chemical reactivity of the amine compound with iron. Calculation of crystal lattice parameters show that prepare nitrides are similar to stoichiometric Fe{sub 3}N hcp type structure. Lattice expansion was found for hexagonal planes due to increasing nitrogen concentration. Magnetic hysteresis parameters were found to be very sensitive to changes in chemical composition. As the amount of nitrogen increases magnetic remanence and coercivity increase but magnetization and calculated average magnetic moment per Fe atom decrease.

Kaczmarek, W.A. [Australian National Univ., Canberra (Australia). Research School of Physical Sciences and Engineering

1995-12-01

435

Synthesis of 5-oxyquinoline derivatives for reversal of multidrug resistance  

PubMed Central

Summary The inhibition of ABC (ATP binding cassette) transporters is considered a powerful tool to reverse multidrug resistance. Zosuquidar featuring a difluorocyclopropyl-annulated dibenzosuberyl moiety has been found to be an inhibitor of the P-glycoprotein, one of the best-studied multidrug efflux pumps. Twelve 5-oxyisoquinoline derivatives, which are analogues of zosuquidar wherein the dibenzosuberyl-piperazine moiety is replaced by either a diarylaminopiperidine or a piperidone-derived acetal or thioacetal group, have been synthesized as pure enantiomers. Their inhibitory power has been evaluated for the bacterial multidrug-resistance ABC transporter LmrCD and fungal Pdr5. Four of the newly synthesized compounds reduced the transport activity to a higher degree than zosuquidar, being up to fourfold more efficient than the lead compound in the case of LmrCD and about two times better for Pdr5.

Dittrich, Torsten; Hanekop, Nils; Infed, Nacera; Schmitt, Lutz

2012-01-01

436

Synthesis and in vitro antimycobacterial activity of B-ring modified diaryl ether InhA inhibitors  

PubMed Central

In earlier work structure-based design studies resulted in the discovery of alkyl substituted diphenyl ether inhibitors of InhA, the enoyl reductase from Mycobacterium tuberculosis. Compounds such as 5-hexyl-2-phenoxyphenol 19 are nM inhibitors of InhA and inhibit the growth of both sensitive and isoniazid-resistant strains of Mycobacterium tuberculosis with MIC90 values of 1–2 µg/mL. However, despite their promising in vitro activity, these compounds have ClogP values of over 5. In efforts to reduce the lipophilicity of the compounds, and enhance potentially enhance compound bioavailability, a series of B ring analogues of 19 were synthesized that contained either heterocylic nitrogen rings or phenyl rings having amino, nitro, amide or piperazine functions. Compounds 3c, 3e and 14a show comparable MIC90 values to that of 19, but have improved ClogP values.

am Ende, Christopher W.; Knudson, Susan E.; Liu, Nina; Childs, James; Sullivan, Todd J.; Boyne, Melissa; Xu, Hua; Gegina, Yelizaveta; Knudson, Dennis L.; Johnson, Francis; Peloquin, Charles A.; Slayden, Richard A.; Tonge, Peter J.

2008-01-01

437

Regulatory role of adrenergic neurotransmitters on the spontaneous muscular activity in the ruminant trematode Paramphistomum cervi (Paramphistomatidae).  

PubMed

The neuromuscular system of helminths is an important area for target identification and drug development. Many anthelmintics, namely ivermectin, levamisole, piperazine, pyrantel, praziquantel and organophosphates, produce paralysis of helminths by affecting their neuromuscular systems. The neuromuscular system of helminths is also an important area of research to identify some of the important differences between the neuromuscular physiology of helminths and mammals. The identification of differences would help in developing newer target-specific, safe and effective anthelmintics. The present study was carried out to investigate the effects of different adrenergic neurotransmitters (epinephrine, norepinephrine, dopamine, l-dopa) and their antagonists (propranolol and haloperidol) on the spontaneous muscular activity of isometrically mounted Paramphistomum cervi. PMID:23721888

Saikia, B; Barua, C C; Hazarika, S; Lahon, L C; Saikia, D; Borah, R S; Verma, P K

2013-05-31

438

Process for removing acidic gases from gaseous mixtures using aqueous scrubbing solutions containing heterocyclic nitrogen compounds  

SciTech Connect

A process is described for removing acid gases selected from hydrogen sulfide and carbon dioxide from gaseous feeds. The process comprises: contacting the feed with an aqueous scrubbing solution comprising water and 1 to 11 moles of a heterocyclic nitrogen compound per liter of solution which compound is selected from the group consisting of imidazole, a C/sub 1/-C/sub 3/ alkyl-substituted imidazole where the alkyl groups are bonded to at least one carbon atom, and a C/sub 1/-C/sub 3/ alkyl- or C/sub 1/-C/sub 3/ hydroxayalkyl-substituted piperazine where the alkyl or hydrozyalkyl groups are bonded to both nitrogen atoms of the ring. The compound has a pKa no greater than about 8, at conditions whereby acid gases are absorbed by the scrubbing solution.

Pan, Y.C.; Savage, D.W.

1986-11-25

439

Diketopiperazine alkaloids from a mangrove rhizosphere soil derived fungus Aspergillus effuses H1-1.  

PubMed

Effusin A (1), a spirobicyclic N,O-acetal derivative with an unprecedented 3',3a',5',6'-tetrahydrospiro[piperazine-2,2'-pyrano[2,3,4-de]chromene] ring system, and a spiro-polyketide-diketopiperazine hybrid dihydrocryptoechinulin D (2) were isolated from a mangrove rhizosphere soil derived fungus, Aspergillus effuses H1-1. Their structures were determined by detailed spectroscopic analysis. Effusin A (1) and dihydrocryptoechinulin D (2) occurred as racemates, the enantiomers of which were separated and characterized by online HPLC-ECD analysis and their absolute configurations were determined by the solution TDDFT ECD calculation approach. The cytotoxic effects of 1 and 2 were preliminarily evaluated and 2 showed potent activity on P388 cells with an IC(50) value of 1.83 ?M. The target of racemic 2 was also investigated and the (12R,28S,31S)-2 enantiomer showed selectivity against topoisomerase I. PMID:23111956

Gao, Huquan; Liu, Weizhong; Zhu, Tianjiao; Mo, Xiaomei; Mándi, Attila; Kurtán, Tibor; Li, Jing; Ai, Jing; Gu, Qianqun; Li, Dehai

2012-10-30

440

Catalytic Ugi-type condensation of ?-isocyanoacetamide and chiral cyclic imine: access to asymmetric construction of several heterocycles.  

PubMed

Several novel heterocycles have been constructed asymmetrically on the basis of a catalytic Ugi-type condensation of ?-isocyanoacetamide and chiral cyclic imine. The combination of phenylphosphilic acid and trifluoroethanol is exploited to promote an Ugi-type reaction with ?-isocyanoacetamide for the first time. By means of this reaction, chiral 3-oxazolyl morpholin-2-one/piperazin-2-one derivatives are synthesized with high yields and excellent stereoselectivities. As electron-rich azadienes, these condensation products are further transformed to fused tricyclic frameworks by treatment with appropriate dienophiles such as maleic anhydride and unsaturated acyl chlorides via domino processes. Moreover, a one-pot, three-component synthesis of the chiral tricyclic frameworks from isocyanoacetamide, imine, and maleic anhydride is also feasible. PMID:23442048

Xia, Liang; Li, Sheng; Chen, Ruijiao; Liu, Kai; Chen, Xiaochuan

2013-03-06

441

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

2011-06-14

442

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. The baseline campaign with 30% MEA has given heat duties from 40 to 70 kcal/gmol CO{sub 2} as predicted by the stripper model. The Flexipak 1Y structured packing gives significantly better performance than IMTP 40 duped packing in the absorber, but in the stripper the performance of the two packings is indistinguishable. The FTIR analyzer measured MEA volatility in the absorber represented by an activity coefficient of 0.7. In the MEA campaign the material balance closed with an average error of 3.5% and the energy balance had an average error of 5.9.

Gary T. Rochelle; Marcus Hilliard; Eric Chen; Babatunde Oyenekan; Ross Dugas; John McLees

2005-07-31

443

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. Stripper modeling suggests the energy requirement with a simple stripper will be about the same for 5 m K{sup +}/2.5 m PZ and 7 m MEA. Modeling with a generic solvent shows that the optimum heat of CO{sub 2} desorption to minimize heat duty lies between 15 and 25 kcal/gmol. On-line pH and density measurements are effective indicators of loading and total alkalinity for the K+/PZ solvent. The baseline pilot plant campaign with 30% MEA has been started.

Gary T. Rochelle; Eric Chen; Jennifer Lu; Babatunde Oyenekan; Ross Dugas

2005-04-29

444

Design and evaluation of naphthol- and carbazole-containing fluorescent sigma ligands as potential probes for receptor binding studies.  

PubMed

Some 3,3-dimethyl-1-(3-naphthylpropyl)piperidine and 1-cyclohexyl-4-(3-naphthylpropyl)piperazine derivatives, structurally containing naphthol as a fluorescent moiety, were prepared for being potentially used as fluorescent sigma ligands. Structurally related analogs were also prepared, where the naphthalene nucleus was replaced by the fluorescent carbazole moiety and chain length was varied. For all compounds the in vitro affinities toward sigma receptors and Delta8-Delta7 sterol isomerase site were measured, and the fluorescent properties were determined. Compound 19 gave the best results both for sigma receptor affinities (sigma1, Ki = 6.78 nM and sigma2, Ki = 26.4 nM) and fluorescence features; thus, it was chosen for in vitro saturation binding analysis at sigma receptors. The good results obtained in such assay suggested that the fluorescent compound 19 could be used instead of a radioligand in "green" binding assays. PMID:17713896

Ferorelli, Savina; Abate, Carmen; Colabufo, Nicola Antonio; Niso, Mauro; Inglese, Carmela; Berardi, Francesco; Perrone, Roberto

2007-08-22

445

[Trichomonacidal drugs. 6. 2,4-Dichloro derivatives of piperidino- and piperazinyl-1,3,5-triazine].  

PubMed

The nucleophilic substitution of one chlorine atom in cyanuric chloride (1) by piperidine derivatives (2a-c) leads to the 6-substituted 2,4-dichloro-1,3,5-triazines (3a-c). Reaction of 1 with piperazine derivatives (4a-c) yields the substituted 2,4-dichloro-6-(1-piperazinyl)-1,3,5-triazines (5a-c). Structures of type 3 and 5 may be characterized by the spectroscopic data. In the mass spectra, the degradation of 3c leading to the base peak comprises the cleavage into a 2,4-dichlorotriazinyl radical and a 3,4-dihydroquinolinium ion m/e 132. Strong activity is exhibited by 5a and 5b towards Trichomonas vaginalis. Moreover, 5a displays strong antimycotic activity towards Trichophyton mentagrophytes, Trichophyton rubrum, and Microsporum canis. Additionally, 5a and 5b are capable of exerting very strong anthelminthic activity towards Caenorhabditis elegans. PMID:3501724

Kreutzberger, A; Kochanowski, R

1987-09-01

446

A blocker of N- and T-type voltage-gated calcium channels attenuates ethanol-induced intoxication, place preference, self-administration, and reinstatement.  

PubMed

There is a clear need for new therapeutics to treat alcoholism. Here, we test our hypothesis that selective inhibitors of neuronal calcium channels will reduce ethanol consumption and intoxication, based on our previous studies using knock-out mice and cell culture systems. We demonstrate that pretreatment with the novel mixed N-type and T-type calcium channel antagonist 1-(6,6-bis(4-fluorophenyl)hexyl)-4-(3,4,5-trimethoxybenzyl)piperazine (NP078585) reduced ethanol intoxication. NP078585 also attenuated the reinforcing and rewarding properties of ethanol, measured by operant self-administration and the expression of an ethanol conditioned place preference, and abolished stress-induced reinstatement of ethanol seeking. NP078585 did not affect alcohol responses in mice lacking N-type calcium channels. These results suggest that selective calcium channel inhibitors may be useful in reducing acute ethanol intoxication and alcohol consumption by human alcoholics. PMID:18987207

Newton, Philip M; Zeng, Lily; Wang, Victoria; Connolly, Jacklyn; Wallace, Melisa J; Kim, Chanki; Shin, Hee-Sup; Belardetti, Francesco; Snutch, Terrance P; Messing, Robert O

2008-11-01

447

Mutagenicity of urine from mice exposed orally to nitrite and various aminated antiparasitic drugs  

SciTech Connect

Mutagenic N-nitroso compound formation from the in vitro reaction of amebicides and anthelmintic drugs, which are pyrimidine derivatives or contain secondary aliphatic amines or heterocyclic nitrogens, has been previously described. Under similar conditions, antiparasitic drugs containing halogenated derivatives of tertiary amines or quaternary ammonium salts do not form mutagenic nitrosated compounds. In the present study the mutagenic activity of mouse urine was determined after oral administration of sodium nitrite and the two above-mentioned groups of drugs. Results show that the simultaneous administration of piperazine or chloroquine with sodium nitrite produced urinary mutagens that appeared conjugated as glucuronides, whereas pyrantel pamoate and dehydroemetine in the presence of nitrite caused only slightly mutagenic urine. No mutagenic activity was detected in the urine of mice to which halogenated derivatives of tertiary amines (iodochlorhydroxyquin) or quaternary ammonium salts (bephenium hydroxynaphthoate) were administered together with nitrite.

Alba, M.A.; Aguirre, J.E.; Ramirez, J.; de Nava, C.C. (U.N.A.M. (Mexico))

1989-01-01

448

Open-Framework Cobalt (II) Phosphates with Sodalite-Related Architectures  

Microsoft Academic Search

Three new framework cobalt (II) phosphates have been synthesized hydrothermally in the presence of piperazine as a structure-directing agent. Crystal data: compound I, [C4N2H12][Co(HPO4)2], monoclinic space group=P21\\/n 001(no. 14), a=8.5521(10) Å, b=13.5791(15) Å, c=10.0405(11) Å, ?=96.855(2)°, V=1157.7(2) Å3, Z=4, M=339.04, Dc= 1.945 g m?3, MoK?, ?=0.71073 Å, R1(F0)=0.053; compound II, [C4N2H11][Co2(PO4)(H2PO4)2], monoclinic space group=C2\\/c (no. 15), a=13.444(5) Å, b=12.874(5) Å,

S. Neeraj; Maria L. Noy; C. N. R. Rao; Anthony K. Cheetham

2002-01-01

449

Open-Framework Cobalt (II) Phosphates with Sodalite-Related Architectures  

Microsoft Academic Search

Three new framework cobalt (II) phosphates have been synthesized hydrothermally in the presence of piperazine as a structure-directing agent. Crystal data: compound I, [C4N2H12][Co(HPO4)2], monoclinic space group=P21\\/n 001(no. 14), a=8.5521(10) Å, b=13.5791(15) Å, c=10.0405(11) Å, beta=96.855(2)°, V=1157.7(2) Å3, Z=4, M=339.04, Dc= 1.945 g m-3, MoKalpha, lambda=0.71073 Å, R1(F0)=0.053; compound II, [C4N2H11][Co2(PO4)(H2PO4)2], monoclinic space group=C2\\/c (no. 15), a=13.444(5) Å, b=12.874(5) Å,

S. Neeraj; Maria L. Noy; C. N. R. Rao; Anthony K. Cheetham

2002-01-01

450

UV-triggered affinity capture identifies interactions between the Plasmodium falciparum multidrug resistance protein 1 (PfMDR1) and antimalarial agents in live parasitized cells.  

PubMed

A representative of a new class of potent antimalarials with an unknown mode of action was recently described. To identify the molecular target of this class of antimalarials, we employed a photo-reactive affinity capture method to find parasite proteins specifically interacting with the capture compound in living parasitized cells. The capture reagent retained the antimalarial properties of the parent molecule (ACT-213615) and accumulated within parasites. We identified several proteins interacting with the capture compound and established a functional interaction between ACT-213615 and PfMDR1. We surmise that PfMDR1 may play a role in the antimalarial activity of the piperazine-containing compound ACT-213615. PMID:23754276

Brunner, Ralf; Ng, Caroline L; Aissaoui, Hamed; Akabas, Myles H; Boss, Christoph; Brun, Reto; Callaghan, Paul S; Corminboeuf, Olivier; Fidock, David A; Frame, Ithiel J; Heidmann, Bibia; Le Bihan, Amélie; Jenö, Paul; Mattheis, Corinna; Moes, Suzette; Müller, Ingrid B; Paguio, Michelle; Roepe, Paul D; Siegrist, Romain; Voss, Till; Welford, Richard W D; Wittlin, Sergio; Binkert, Christoph

2013-06-10

451

Preparation and characterization of new tetradentate Schiff base metal complexes and biological activity evaluation  

NASA Astrophysics Data System (ADS)

A new Schiff base (N,N?-ethylene (bis 1-cyclopropyl-6-fluoro-4-oxo-7-(piperazine-1-yl)-quinoline-3-carboxylic acid) and its Zn(II), Zr(IV), Ce(IV) and U(VI) complexes were synthesized and characterized by elemental analysis, molar conductance, IR, UV-Vis, 1H NMR spectra, magnetic moment, thermal analysis as well as mass spectra. The IR results demonstrate that the tetradentate binding mode of the ligand involving azomethine nitrogen and carboxylato oxygen atoms. The calculated bond length and the bond stretching force constant, F(UO), values for UO2 bond are 1.744 Å and 654.49 N m-1. The antimicrobial activity of the synthesized ligand and its complexes were screened and the results showed that the metal complexes were found to be more active than free ligand.

Sadeek, S. A.; El-Attar, M. S.; Abd El-Hamid, S. M.

2013-11-01

452

Catalytic oxidation of cyclohexane by a binuclear Fe(III) complex biomimetic to methane monooxygenase.  

PubMed

A novel binuclear Fe(III) complex [Fe(III)(BPMP)Cl(mu-O)Fe(III)Cl3] (1) was prepared from the reaction between (bis(2-pyridylmethyl)-1,4-piperazine) and [Fe(OH2)6]Cl3, in acetonitrile. The title compound was characterized by spectroscopic, electrochemical and X-ray crystallography analysis. The catalytic activity of the complex was evaluated through cyclohexane oxidation, using hydrogen peroxide as the terminal oxidant. Reaction products were identified by gas chromatography. Conversions up to 19.2% were observed (12.6% and 6.6% yields for cyclohexanol and cyclohexanone, respectively). The catalytic activity exhibited by 1 suggests that it can be considered as a functional biomimetic analog to methane monooxygenase. PMID:16122805

Esmelindro, Maria Carolina; Oestreicher, Enrique G; Márquez-Alvarez, Heiddy; Dariva, Cláudio; Egues, Sílvia M S; Fernandes, Christiane; Bortoluzzi, Adailton J; Drago, Valderes; Antunes, O A C

2005-10-01

453

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

2012-12-27

454

Anthelmintic activities of chloroform and methanol extracts of Buchholzia coriacea Engler seed.  

PubMed

The anthelmintic potentials of the chloroform and methanol extracts of Buchholzia coriacea Engler seed were investigated. In folklore medicine, B. coriacea (Capparidaceae) is believed to be useful in the treatment of various kinds of ailments and diseases. At doses of 10 mg/kg, 25 mg/kg and 50 mg/kg, the extracts were tested against Eudrilus eugeniae (earthworm) and Bunostomum phlebotomum (cattle hookworm). The extracts exhibited dose-dependent anthelmintic effects on the earthworms and hookworms. The methanol extract at 50 mg/kg was the most active extract against the helminths, and the activity of the methanol extract was not significantly different from that of piperazine hydrate (reference drug, 10 mg/kg) against the earthworms. PMID:21344210

Fred-Jaiyesimi, Adediwura A; Adepoju, Adeola; Egbebunmi, Oluwatosin

2011-02-23

455

Asymmetric Aminolytic Kinetic Resolution of Racemic Epoxides Using Recyclable Chiral Polymeric Co(III)-Salen Complexes: A Protocol for Total Utilization of Racemic Epoxide in the Synthesis of (R)-Naftopidil and (S)-Propranolol.  

PubMed

Chiral polymeric Co(III) salen complexes with chiral ((R)/(S)-BINOL, diethyl tartrate) and achiral (piperazine and trigol) linkers with varying stereogenic centers were synthesized for the first time and used as catalysts for aminolytic kinetic resolution (AKR) of a variety of terminal epoxides and glycidyl ethers to get enantio-pure epoxides (ee, 99%) and N-protected ?-amino alcohols (ee, 99%) with quantitative yield in 16 h at RT under optimized reaction conditions. This protocol was also used for the synthesis of two enantiomerically pure drug molecules (R)-Naftopidil (?1-blocker) and (S)-Propranolol (?-blocker) as a key step via AKR of single racemic naphthylglycidyl ether with Boc-protected isoproylamine with 100% epoxide utilization at 1 g level. The catalyst 1 was successfully recycled for a number of times. PMID:23899243

Kumar, Manish; Kureshy, Rukhsana I; Shah, Arpan K; Das, Anjan; Khan, Noor-Ul H; Abdi, Sayed H R; Bajaj, Hari C

2013-08-28

456

Cinnarizinium 3,5-dinitro-salicylate.  

PubMed

THE TITLE COMPOUND [SYSTEMATIC NAME: 4-diphenyl-methyl-1-(3-phenylprop-2-en-1-yl)-piperazin-1-ium 2-carb-oxy-4,6-dinitro-pheno-late], C(26)H(29)N(2) (+)·C(7)H(3)N(2)O(7) (-), is the dinitro-salicylate salt of a tertiary amine. Deprotonation of the carb-oxy-lic acid group occurred on the phenolic hy-droxy group. The diaza-cyclo-hexane ring adopts a chair conformation. Intra-molecular O-H?O and inter-molecular C-H?O and N-H?O hydrogen bonds are observed. The N-H?O hydrogen bonds are bifurcated at the H atom and connect the cinnarizinium and 3,5-dinitro-salicylate ions together. Inter-molecular C-H?O hydrogen bonds connect the components into layers perpendicular to the crystallographic a axis. PMID:22606110

Dayananda, Alaloor S; Yathirajan, Hemmige S; Gerber, Thomas; Hosten, Eric; Betz, Richard

2012-03-24

457

Evidence that tolerance to the anxiogenic-like effects of mCPP does not involve alteration in the function of 5-HT(2C) receptors in the rat choroid plexus.  

PubMed

The mechanisms by which 1-(3-chlorophenyl) piperazine (mCPP) causes anxiety are unclear, but it has been suggested that the serotonin 5-HT(2C) receptor subtype may be involved in this effect. We have therefore studied the effect of chronic treatment (3 weeks) with mCPP in two animal models of anxiety (light/dark choice task in mice and elevated plus-maze test in rats) and subsequently assessed the function of 5-HT(2C) receptors (measured by maximal stimulation of 5-HT(2C) receptor-mediated phosphoinositide hydrolysis) in rat choroid plexus, where the receptor is present at very high levels. mCPP treatment regimens led to a tolerance to the anxiogenic-like action of the drug, but failed to alter the second messenger coupling of the 5-HT(2C) receptors in the choroid plexus, thereby suggesting the involvement of different mechanisms in this behavioral effect. PMID:11224245

Griebel, G.; Moreau, J.-L.; Jenck, F.; Mutel, V.; Martin, J.R.; Misslin, R.

1994-10-01

458

Diastereoselective reactions in glycine templates containing an ent-ardeemin fragment.  

PubMed

Self-consistent reaction field solvation models derived from SCF-MO calculations are shown to be reliable in modeling the diastereoselectivity of the reactions of the anion and cation derived from (4S)-2,4-dimethyl-2,4-dihydro-1H-pyrazino[2,1-b]quinazoline-3,6-dione (1) at C(1) with electrophiles and nucleophiles, respectively. The found anti/syn ratio of compound 8, which is a seco-ent-ardeemin analogue obtained by alkylation of 1 with gramine methiodide, confirms this computational model. A close similarity between the calculated geometry of the piperazine ring in the anti isomers of 1,2,4-trialkyl derivatives and that deduced from their (1)H NMR (solution) and X-ray data has been also established. PMID:11925204

Martín-Santamaría, Sonsoles; Corzo-Suárez, Raúl; Avendaño, Carmen; Espada, Modesta; Gago, Federico; García-Granda, Santiago; Rzepa, Henry S

2002-04-01

459

SB399885 is a potent, selective 5HT 6 receptor antagonist with cognitive enhancing properties in aged rat water maze and novel object recognition models  

Microsoft Academic Search

SB-399885 (N-[3,5-dichloro-2-(methoxy)phenyl]-4-(methoxy)-3-(1-piperazinyl)benzenesulfonamide) has high affinity for human recombinant and native 5-HT6 receptors, with pKi values 9.11±0.03 and 9.02±0.05, respectively and is a potent competitive antagonist (pA2 7.85±0.04). It displays over 200-fold selectivity for the 5-HT6 receptor over all other receptors, ion channels and enzymes tested to date. SB-399885 inhibited ex vivo [125I]SB-258585 (4-Iodo-N-[4-methoxy-3-(4-methyl-piperazin-1-yl)-phenyl]-benzenesulfonamide) binding with an ED50 of 2.0±0.24 mg\\/kg p.o.

Warren D. Hirst; Tania O. Stean; Derek C. Rogers; David Sunter; Pippa Pugh; Stephen F. Moss; Steven M. Bromidge; Graham Riley; Douglas R. Smith; Sarah Bartlett; Christian A. Heidbreder; Alan R. Atkins; Laurent P. Lacroix; Lee A. Dawson; Andrew G. Foley; Ciaran M. Regan; Neil Upton

2006-01-01

460

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. Modeling of stripper performance suggests that vacuum stripping may be an attractive configuration for all solvents. Flexipac 1Y structured packing performs in the absorber as expected. It provides twice as much mass transfer area as IMTP No.40 dumped packing. Independent measurements of CO{sub 2} solubility give a CO{sub 2} loading that is 20% lower than that Cullinane's values with 3.6 m PZ at 100-120 C. The effective mass transfer coefficient (K{sub G}) in the absorber with 5 m K/2.5 m PZ appears to be 0 to 30% greater than that of 30 wt% MEA.

Gary T. Rochelle; Marcus Hilliard; Eric Chen; Babatunde Oyenekan; Ross Dugas; John McLees; Andrew Sexton; Daniel Ellenberger

2005-10-26

461

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

462

Novel highly potent serotonin 5-HT7 receptor ligands: Structural modifications to improve pharmacokinetic properties.  

PubMed

Here we report the synthesis, pharmacological and pharmacokinetic evaluation of a pilot set of compounds structurally related to the potent and selective 5-HT7 ligand LP-211. Among the studied compounds, N-pyridin-3-ylmethyl-3-[4-[2-(4-methoxyphenyl)phenyl]piperazin-1-yl]ethoxy]propanamide (4b) showed high affinity for 5-HT7 receptors (Ki=23.8nM), selectivity over 5-HT1A receptors (>50-fold), in vitro metabolic stability (82%) and weak interaction with P-glycoprotein (BA/AB=3.3). Compound 4b was injected ip in mice to preliminarily evaluate its distribution between blood and brain. PMID:24100077

Lacivita, Enza; Di Pilato, Pantaleo; Letizia Stama, Madia; Colabufo, Nicola Antonio; Berardi, Francesco; Perrone, Roberto; De Filippis, Bianca; Laviola, Giovanni; Adriani, Walter; Niso, Mauro; Leopoldo, Marcello

2013-09-17

463

Target sites of anthelmintics.  

PubMed

This paper reviews sites of action of anthelmintic drugs including: (1) levamisole and pyrantel, which act as agonists at nicotinic acetylcholine receptors of nematodes; (2) the avermectins, which potentiate or gate the opening of glutamategated chloride channels found only in invertebrates; (3) piperazine, which acts as an agonist at GABA gated chloride channels on nematode muscle; (4) praziquantel, which increases the permeability of trematode tegument to calcium and results in contraction of the parasite muscle; (5) the benzimidazoles, like thiabendazole, which bind selectively to parasite beta-tubulin and prevents microtubule formation; (6) the proton ionophores, like closantel, which uncouple oxidative phosphorylation; (7) diamphenethide and clorsulon, which selectively inhibit glucose metabolism of Fasciola and; (8) diethylcarbamazine, which appears to interfere with arachidonic acid metabolism of filarial parasites and host. The review concludes with brief comments on the development of anthelmintics in the future. PMID:9309773

Martin, R J; Robertson, A P; Bjorn, H

1997-01-01

464

Synthesis and biological evaluation of [1,2,4]triazolo[3,4-a]phthalazine and tetrazolo[5,1-a]phthalazine derivatives bearing substituted benzylpiperazine moieties as positive inotropic agents.  

PubMed

Two series of [1,2,4]triazolo[3,4-a]phthalazine and tetrazolo[5,1-a]phthalazine derivatives bearing substituted benzylpiperazine moieties have been synthesized and evaluated for their positive inotropic activity by measuring left atrium stroke volume on isolated rabbit heart preparations. The majority of the derivatives exhibited better in vitro activity than the existing drug, milrinone, and 6-((4-(4-methoxyphenyl)piperazin-1-yl)methyl)tetrazolo[5,1-a]phthalazine. 8 m in particular was identified as the most potent with an increased stroke volume of 12.02 ± 0.20% (milrinone: 2.46 ± 0.07%) at a concentration of 3 × 10(-5)  m. The chronotropic effects of the compounds that exhibited good potency were also evaluated. PMID:23279930

Wu, Yan; Sun, Liang-Peng; Ma, Long-Xu; Che, Jian; Song, Ming-Xia; Cui, Xun; Piao, Hu-Ri

2013-03-26

465

Studies of serotonin uptake and serotonin/sub 1A/ receptor using photoaffinity probes  

SciTech Connect

The serotonergic system in the central nervous system (CNS) has been implicated in many physiological functions. The objectives of this study are: (1) to develop a new photoaffinity probe that can be used to identify the protein associated with the substrate binding site of the 5-HT uptake carrier, (2) to investigate the existence of different conformational states of the 5-HT carrier, (3) to solubilize the 5-HT/sub 1a/ receptor proteins from bovine hippocampus, and (4) to identify the 5-HT/sub 1a/ receptor proteins using a new photoaffinity probe, i.e., 1-(2-(4-aminophenyl)ethyl)4-(3-trifluoromethylphenyl)piperazine ((/sup 3/H)p-azido-PAPP), with high affinity for 5-HT/sub 1a/ receptor.

Lee, J.D.

1986-01-01

466